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Nathan Goodyear

Lipid Peroxidation: Production, Metabolism, and Signaling Mechanisms of Malondialdehyde... - 0 views

www.hindawi.com/...360438

MDA malondialdehyde peroxidation oxidative stress free radicals

shared by Nathan Goodyear on 05 Dec 17 - No Cached
  • Hydroxyl radicals cause oxidative damage to cells because they unspecifically attack biomolecules [22] located less than a few nanometres from its site of generation and are involved in cellular disorders such as neurodegeneration [23, 24], cardiovascular disease [25], and cancer [26, 27].
  • It is generally assumed that in biological systems is formed through redox cycling by Fenton reaction, where free iron (Fe2+) reacts with hydrogen peroxide (H2O2) and the Haber-Weiss reaction that results in the production of Fe2+ when superoxide reacts with ferric iron (Fe3+)
  • other transition-metal including Cu, Ni, Co, and V can be responsible for formation in living cells
  • ...20 more annotations...
  • The hydroperoxyl radical () plays an important role in the chemistry of lipid peroxidation
  • The is a much stronger oxidant than superoxide anion-radical
  • Lipid peroxidation can be described generally as a process under which oxidants such as free radicals or nonradical species attack lipids containing carbon-carbon double bond(s), especially polyunsaturated fatty acids (PUFAs) that involve hydrogen abstraction from a carbon, with oxygen insertion resulting in lipid peroxyl radicals and hydroperoxides as described previously
  • under medium or high lipid peroxidation rates (toxic conditions) the extent of oxidative damage overwhelms repair capacity, and the cells induce apoptosis or necrosis programmed cell death
  • The overall process of lipid peroxidation consists of three steps: initiation, propagation, and termination
  • Once lipid peroxidation is initiated, a propagation of chain reactions will take place until termination products are produced.
  • The main primary products of lipid peroxidation are lipid hydroperoxides (LOOH)
  • Among the many different aldehydes which can be formed as secondary products during lipid peroxidation, malondialdehyde (MDA), propanal, hexanal, and 4-hydroxynonenal (4-HNE) have been extensively studied
  • MDA has been widely used for many years as a convenient biomarker for lipid peroxidation of omega-3 and omega-6 fatty acids because of its facile reaction with thiobarbituric acid (TBA)
  • MDA is one of the most popular and reliable markers that determine oxidative stress in clinical situations [53], and due to MDA’s high reactivity and toxicity underlying the fact that this molecule is very relevant to biomedical research community
  • 4-HNE is considered as “second toxic messengers of free radicals,” and also as “one of the most physiologically active lipid peroxides,” “one of major generators of oxidative stress,” “a chemotactic aldehydic end-product of lipid peroxidation,” and a “major lipid peroxidation product”
  • MDA is an end-product generated by decomposition of arachidonic acid and larger PUFAs
  • Identifying in vivo MDA production and its role in biology is important as indicated by the extensive literature on the compound (over 15 800 articles in the PubMed database using the keyword “malondialdehyde lipid peroxidation” in December 2013)
  • MDA reactivity is pH-dependent
  • When pH decreases MDA exists as beta-hydroxyacrolein and its reactivity increases
  • MAA adducts are shown to be highly immunogenic [177–181]. MDA adducts are biologically important because they can participate in secondary deleterious reactions (e.g., crosslinking) by promoting intramolecular or intermolecular protein/DNA crosslinking that may induce profound alteration in the biochemical properties of biomolecules and accumulate during aging and in chronic diseases
  • MDA is an important contributor to DNA damage and mutation
  • This MDA-induced DNA alteration may contribute significantly to cancer and other genetic diseases.
  • Dietary intake of certain antioxidants such as vitamins was associated with reduced levels of markers of DNA oxidation (M1dG and 8-oxodG) measured in peripheral white blood cells of healthy subjects, which could contribute to the protective role of vitamins on cancer risk
  • 4-HNE is an extraordinarily reactive compound
  • Nathan Goodyear on 05 Dec 17
     
    Great review of lipid peroxidation
Nathan Goodyear

Aging and Luteinizing Hormone Effects on Reactive Oxygen Species Production and DNA Dam... - 0 views

www.biolreprod.org/...100.full

LH ROS reactive oxygen species oxidative stress testicles Testosterone male hormone hormones

shared by Nathan Goodyear on 04 Dec 13 - No Cached
  • Nathan Goodyear on 04 Dec 13
     
    Interesting rat model finds that stimulation of the leydig cells of the testis by LH induces ROS.  May be one of the mechanisms by which androgen therapy will induce long-term requirement for replacement.
Nathan Goodyear

Endothelial dysfunction of rat coronary arteries after exposure to low concentrations o... - 0 views

www.ncbi.nlm.nih.gov/...PMC3081124

Hg mercury NO cardiovascular disease heart health ROS reactive oxygen species oxidative stress

shared by Nathan Goodyear on 16 Sep 14 - No Cached
  • Nathan Goodyear on 16 Sep 14
     
    low dose, chronic exposure induces ROS and decreased NO availability.  This decrease in NO will result in increase vasoconstriction.  This will have localized effects and will result in increased central pressure as a result of the increased peripheral pressure.  In addition, inhibition of COMT will result in increase in catecholeamines.
Nathan Goodyear

Chronic Inflammation and Cytokines in the Tumor Microenvironment - 0 views

www.hindawi.com/...149185

inflammation cytokines tumor cancer inflammatory IL-6 IL-10 TNF-alpha

shared by Nathan Goodyear on 26 Jun 15 - No Cached
  • Nathan Goodyear on 26 Jun 15
     
    Acute inflammation is a response to an alteration induced by a pathogen or a physical or chemical insult, which functions to eliminate the source of the damage and restore homeostasis to the affected tissue. However, chronic inflammation triggers cellular events that can promote malignant transformation of cells and carcinogenesis. Several inflammatory mediators, such as TNF-α, IL-6, TGF-β, and IL-10, have been shown to participate in both the initiation and progression of cancer. In this review, we explore the role of these cytokines in important events of carcinogenesis, such as their capacity to generate reactive oxygen and nitrogen species, their potential mutagenic effect, and their involvement in mechanisms for epithelial mesenchymal transition, angiogenesis, and metastasis. Finally, we will provide an in-depth analysis of the participation of these cytokines in two types of cancer attributable to chronic inflammatory disease: colitis-associated colorectal cancer and cholangiocarcinoma.
Nathan Goodyear

Urinary Estrogens and Estrogen Metabolites and Subsequent Risk of Breast Cancer among P... - 0 views

cancerres.aacrjournals.org/...696.full

estrogen metabolites estrogen metabolism ER estrogen receptors ROS hormones cancer breast cancer

shared by Nathan Goodyear on 07 Oct 15 - No Cached
  • both 2- and 4-catechol estrogen metabolites bind to the ER with affinities comparable with estradiol, 4-catechol estrogen metabolites have lower dissociation rates than estradiol and an enhanced ability to upregulate ER-dependent processes
  • 2-catechol estrogen metabolites act as either weak mitogens (39) or weak inhibitors of cell proliferation
  • While 16α-hydroxyestrone binds to the ER with lower affinity than estradiol, it binds covalently (41) and leads to a constitutively activated ER
  • ...15 more annotations...
  • 4-hydroxyestradiol and 16α-hydroxyestrone increasing proliferation and decreasing apoptosis in a manner similar to estradiol; however, these effects were achieved only at concentrations 10-fold higher than estradiol (39). In contrast, 2-hydroxyestradiol did not have substantial proliferative or antiapoptotic effects
  • In our study, the associations with both 2-hydroxyestrone and 16α-hydroxyestrone were nonsignificantly inverse and we did not observe a consistent trend or significant associations between the 2-hydroxyestrone:16α-hydroxyestrone ratio and breast cancer risk
  • Ratios of the 3 hydroxylation pathways were not significantly associated with risk although the 2:16-pathway and 4:16-pathway ratios were suggestively inversely associated
  • a significant inverse association with the ratio of parent estrogens to estrogen metabolites
  • several potentially estrogenic and genotoxic mechanisms
  • Estrogen metabolites also can be genotoxic
  • Catechol estrogens can be oxidized into quinones and induce DNA damage directly through the formation of DNA adducts, or indirectly via redox cycling and generation of reactive oxygen species
  • the oxidized forms of the catechol estrogens differ in their ability to damage DNA through adducts, with oxidized 2-catechols forming stable and reversible DNA adducts and oxidized 4-catechols forming unstable adducts, which lead to depurination and mutations
  • 2- and 4-catechols have been shown to produce reactive oxygen species and induce oxidative DNA damage
  • act independently from the ER
  • 16α-Hydroxyestrone also may be genotoxic
  • While the catechol estrogens have estrogenic and genotoxic potential, the methylated catechol estrogens, which are catechol estrogens with one hydroxyl group methylated, have been hypothesized to lower the risk of breast cancer
  • The suggested mechanisms are indirect, by decreasing circulating levels of catechol estrogens and thereby the opportunity for catechols to exert genotoxic or proliferative effects, or direct, by inhibiting tumor growth and inducing apoptosis
  • the balance between phase I (oxidation) and phase II (methylation) metabolism of estrogen may be important in hormonally related cancer development.
  • Despite the estrogenic and genotoxic potential of many of the estrogen metabolites, we only observed a significantly increased breast cancer risk with one estrogen metabolite, 17-epiestriol, which has particularly strong estrogenic activity and binds to both ERα and ERβ with an affinity comparable with estradiol
  • Nathan Goodyear on 07 Oct 15
     
    review of estrogen metabolites and breast cancer risk in premenopausal women.
Nathan Goodyear

Urinary estrogens and estrogen metabolites and subsequent risk of breast cancer among p... - 0 views

www.ncbi.nlm.nih.gov/...PMC3271178

estrogen metabolites estrogen metabolites cancer hormones

shared by Nathan Goodyear on 04 Oct 15 - No Cached
  • While the catechol estrogens have estrogenic and genotoxic potential, the methylated catechol estrogens, which are catechol estrogens with one hydroxyl group methylated, have been hypothesized to lower risk of breast cancer.
  • Despite the estrogenic and genotoxic potential of many of the EM, we only observed a significantly increased breast cancer risk with one EM, 17-epiestriol, which has particularly strong estrogenic activity and binds to both ERα and ERβ with an affinity comparable to estradiol
  • We did not observe reduced risk for higher concentrations of 2-pathway EM relative to 16-pathway EM, nor did we observe a consistent benefit of higher concentrations of methylated catechol EM compared with catechol EM.
  • ...4 more annotations...
  • EM also can be genotoxic, but the individual EM vary in their ability to induce DNA damage
  • Catechol estrogens can be oxidized into quinones and induce DNA damage directly through the formation of DNA adducts, or indirectly via redox cycling and generation of reactive oxygen species
  • the oxidized forms of the catechol estrogens differ in their ability to damage DNA through adducts, with oxidized 2-catechols forming stable and reversible DNA adducts and oxidized 4-catechols forming unstable adducts, which lead to depurination and mutations
  • 2- and 4-catechols have been shown to produce reactive oxygen species and induce oxidative DNA damage (46). These catechols also induce neoplastic transformation in ER-cells, and thus act independently from the ER
  • Nathan Goodyear on 04 Oct 15
     
    Estrogen metabolites.
Nathan Goodyear

HIF-1-mediated metabolic reprogramming reduces ROS levels and facilitates the metastati... - 0 views

www.ncbi.nlm.nih.gov/...PMC3899644

Cancer HIF-1alpha HIF-1 ROS reactive oxygen species reactive oxygenation species

shared by Nathan Goodyear on 12 Dec 18 - No Cached
  • Nathan Goodyear on 12 Dec 18
     
    HIF-1alpha and ROS relationship in cancer
Nathan Goodyear

Antineoplastic Mechanisms of Niclosamide in Acute Myelogenous Leukemia Stem C... - 0 views

cancerres.aacrjournals.org/...2516

Niclosamide cancer leukemia NF-kappaB ROS TNF tumor necrosis factor

shared by Nathan Goodyear on 21 Mar 18 - No Cached
  • Here, we report on niclosamide as an antileukemic agent with two independent antineoplastic mechanisms: NF-κB pathway inactivation and ROS generation
  • In this report, we validated the inhibitory action of niclosamide against tumor necrosis factor (TNF)–induced NF-κB activation in AML cells and identified its mechanism, together with generation of reactive oxygen species (ROS), as being responsible for induced apoptosis of AML cells
  • NF-κB plays a critical role in inflammation, antiapoptotic responses, and carcinogenesis
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  • pharmacologic inhibition of NF-κB was effective in killing AML cells
  • High NF-κB expression is found in primitive human AML blast cells
  • niclosamide inhibited the TNF-induced NF-κB reporter activity in a dose- and time-dependent manner
  • niclosamide inhibiting TNF-induced IKK phosphorylation (Fig. 2A), niclosamide may exert its inhibitory effect at the TAK1 step
  • Pretreatment with niclosamide completely blocked the time- and dose-dependent TNFα-induced alteration of the NF-κB–DNA complex
  • niclosamide inhibited constitutively active NF-κB binding to DNA in U266 cells
  • niclosamide completely abolished the TNFα-induced phosphorylation of IKKα/β and IκBα
  • Accordingly, the TNFα-induced degradation of IκBα was abrogated by niclosamide
  • Nathan Goodyear on 21 Mar 18
     
    Old anti-parasitic medication, niclosamide, found to have anti-leukemic acitivty through inactivation of NF-kappaB and increase in ROS production in in Vitro and in Vivo study.
Nathan Goodyear

Vitamin C increases viral mimicry induced by 5-aza-2′-deoxycytidine | PNAS - 0 views

www.pnas.org/10238

AML leukemia acute myeloid leukemia MDS vitamin C cancer

shared by Nathan Goodyear on 12 May 18 - No Cached
  • Vitamin C alone at concentrations up to 57 μM had little effect on cell growth but was toxic at 228 μM (SI Appendix, Fig. S1B), in line with recent studies of high vitamin C concentrations (125–2,000 μM)
  • In our combination approach, vitamin C increased the effects of low doses of 5-aza-CdR, with 57 μM vitamin C almost doubling the growth inhibition
  • Using the Chou–Talalay method (28), we found that the two compounds indeed acted synergistically, rather than additively, to inhibit cancer cell growth over the physiological ranges of vitamin C in healthy individuals (26–84 μM)
  • ...12 more annotations...
  • These results show that targeting the cancer DNA methylome by combining low-dose 5-aza-CdR and vitamin C stimulates the expression of ERVs, the induction of a cell-autonomous immune activation response, and increased apoptosis of cancer cells
  • The addition of vitamin C to treatment protocols therefore may be a straightforward way to increase the clinical efficacy of such drugs in MDS and leukemia patients
  • Vitamin C deficiency has been seen previously in patients with multiple types of cancer, including hematological malignancies (35⇓–37). We predict that these patients might receive the most benefits from the combination treatment.
  • induction of an innate immune response
  • We therefore measured plasma concentrations of vitamin C in a small number of patients with miscellaneous hematologic malignancies. Strikingly, 58% of patients with hematological neoplasia who were not taking vitamin C supplements had severe vitamin C deficiency (serum concentration <11.4 μM, at which clinical features of scurvy may be manifested) (34), and 33% had vitamin C levels below the normal range
  • it is possible that vitamin C was oxidized to DHA before it was transported into the cells
  • Oral administration of vitamin C should be sufficient for the therapeutic strategy, because the concentrations reported in this study would not require i.v. administration.
    • Nathan Goodyear
      Nathan Goodyear on 12 May 18
       
      This statement lacks a basic understanding of vitamin C pharmacokinetics.
  • Vitamin C is an essential nutrient for humans and has been reported to increase IFN levels in human cells upon virus infection
  • daily treatment with vitamin C alone at physiological concentrations enhanced the expression of viral-defense genes relative to untreated cells
  • When combined with low-dose 5-aza-CdR, physiological concentrations of vitamin C synergistically inhibited cancer-cell growth and induced apoptosis. Such synergy was associated with increased ERV expression and dsRNA in treated cells. The mechanism of action differs from that of vitamin C at higher doses, which involves its pro-oxidant activity, including GSH inhibition, to generate reactive oxygen species
  • This activity has been shown to induce DNA damage and to enhance the sensitivities of myeloid malignancies, multiple myeloma, and cutaneous T-cell lymphoma to arsenic trioxide (41⇓⇓–44). It also can increase chemosensitivity of ovarian cancer cells (27) and selectively kill KRAS or BRAF mutant colorectal cancer cells by inhibiting GAPDH
  • reactive oxygen species
  • Nathan Goodyear on 12 May 18
     
    91% of patients with hematologic malignancies have vitamin C levels that are either low or severly deficient. This study found that vitamin C plus low dose DNA methyltransferase inhibitors have synergistic inhibition of cancer cell proliferation and increased apoptosis.  Unfortunately, the authors claimed that oral vitamin C would be sufficient which indicates an incredible lack of understanding of vitamin C pharmacokinetics.
Nathan Goodyear

The anti-malarial drug artesunate causes cell cycle arrest and apoptosis of triple-nega... - 0 views

www.ncbi.nlm.nih.gov/...30660598

breast cancer cancer artesunate

shared by Nathan Goodyear on 01 Jul 19 - No Cached
  • Nathan Goodyear on 01 Jul 19
     
    ART inhibited breast cancer cell proliferation via a reactive oxygen species (ROS)-dependent G2/M arrest and ROS-independent G1 arrest. ART-treated MDA-MB-468 and SK-BR-3 cells also experienced apoptotic cell death, which was both ROS- and iron-dependent. ART-induced oxidative stress caused the loss of mitochondrial outer membrane integrity and damage to the cellular DNA of MDA-MB-468 and SK-BR-3 cells. Only abstract available...I will post full article once available.
Nathan Goodyear

Hyperbaric oxygen therapy promotes neurogenesis: where do we stand? - 0 views

www.ncbi.nlm.nih.gov/...PMC3231808

hbot hyperbaric therapy hyperbaric brain TBI stroke neurogenesis neuorplasticity

shared by Nathan Goodyear on 18 May 17 - No Cached
  • Numerous in vivo and in vitro studies confirm that HBOT induces neurogenesis
  • HIF-1α is the principal mediator of cellular hypoxia adaptations
  • activated by hypoxia, HIF-1α causes the transcription of its regulated downstream genes, including erythropoietin (EPO) and VEGF which are known to promote neurogenesis
  • ...10 more annotations...
  • The safety of HBOT was also evaluated and it was pointed out that, if given at proper paradigms, like 1.5 ATA for 60 minutes, HBOT will not cause oxygen toxicity
  • Rockswold et al., on the other hand, found that HBOT might be potentially beneficial for severe TBI patients
  • McDonagh et al., concluded that there was insufficient evidence to establish the effectiveness of HBOT in the treatment of TBI
  • The first multicenter, randomized, double-blind, controlled trial in 2009 found that 40-hour HBOT of 24% oxygen at 1.3 ATM produced significant improvement in children's overall functioning, receptive language, social interaction, eye contact, and sensory/cognitive awareness compared to those received slightly pressurized room air
  • Another study in 2010 on 16 autism patients, adopting a similar treatment paradigm, showed no effect on a wide array of behavioral evaluations
  • To date, there is little evidence that HBOT causes malignant growth or metastasis. A history of malignancy should therefore not be considered as a contraindication for HBOT
  • HBOT enhances the production of reactive oxygen species (ROS) and causes oxidative stress in body tissues
  • Excessive accumulation of oxidative stress may contribute to neurodegenerative processes and cell death in the brain, as seen in diseases like Alzheimer's disease (AD) and Parkinson's disease (PD)
  • Hormesis
  • process that results in a functional improvement of cellular stress resistance, survival, and longevity in response to sub-lethal levels of stress
  • Nathan Goodyear on 18 May 17
     
    great review of hbot, brain injury, neuroplasticity and neurogenesis.
Nathan Goodyear

Tumor regionalization after surgery: Roles of the tumor microenvironment and neutrophil... - 0 views

www.nature.com/...s12276-022-00784-2

TME NETosis metastasis surgery cancer tumor microenvironment

shared by Nathan Goodyear on 20 Apr 23 - No Cached
  • tumor surgery must be carefully considered because the risk of metastasis could be increased by the surgical procedure.
  • NETosis, which is the process of forming neutrophil extracellular traps (NETs)
  • surgery-induced metastasis
  • ...61 more annotations...
  • surgery per se can promote cancer metastasis through a series of local and systemic events
  • surgery results in a serious wound that disrupts the structural barrier preventing the outspreading of cancer cells, change the properties of the cancer cells and stromal cells remaining in the tumor microenvironment, or impairs the host defense systems against cancers
    • Nathan Goodyear
      Nathan Goodyear on 23 Apr 23
       
      Key point; add to presentation on surgery and metastasis
  • After the primary tumor is surgically removed, the metastases can start to grow vigorously via neoangiogenesis because the circulating inhibitors disappear
  • infection and inflammation during the postoperative period have been reported to increase the risk of cancer recurrence in patients
  • Surgeons have long suspected that surgery, even if it is a necessary step in cancer treatment, facilitates cancer metastasis
  • Surgery-induced cancer metastasis has been well established in animal models
  • tumor cell dissemination, tumor-favoring immune responses, and neoangiogenesis
  • the surgical resection of primary tumors is beneficial is controversial
  • CTCs abruptly increase just after surgery
  • Even externally palpitating tumors for diagnosis could increase the numbers of CTCs in skin cancer and breast cancer
  • excessive glucocorticoids negatively modulate immune functions
  • immune surveillance against tumors is considered to be impaired by surgical stress
  • In addition to glucocorticoids, during stimulation of the HPA axis, the catecholamine hormones epinephrine and norepinephrine are released from the adrenal medulla
  • NK cell suppression may be attributed to increased levels of catecholamines as well as glucocorticoids
  • In mice bearing a primary tumor, it was observed that the removal of the primary tumor facilitated the growth of highly vascularized metastases
  • primary tumors may secrete angiogenic inhibitors as well as angiogenic activators
  • second phase of tumor recurrence and metastasis, which are newly acquired events, rather than just outcomes of incomplete treatment.
    • Nathan Goodyear
      Nathan Goodyear on 23 Apr 23
       
      Another key point
  • double-edged sword
  • HIF-1 in neutrophils plays a critical role in NETosis and bacteria-killing activity
  • neutrophils play various roles in the initiation and progression of cancer
  • NETosis
  • many inflammatory and neoplastic diseases
  • formation of neutrophil extracellular traps (NETs), which are large extracellular complexes composed of chromatin and cytoplasmic/granular proteins1
  • NETosis has been highlighted as an inflammatory event that promotes cancer metastasis
  • Once activated, neutrophils produce intracellular precursors by using DNA, histones, and granular and cytoplasmic proteins and then spread the mature form of NETs out around themselves
  • A series of these events is called NETosis.
  • neutrophil elastase, myeloperoxidase, cathepsin G, proteinase 3, lactoferrin, gelatinase, lysozyme C, calprotectin, neutrophil defensins, and cathelicidins
  • innate immune response against infection
  • Neutrophils are the most abundant type of granulocytes, comprising 40–70% of all white blood cells
  • two types of NEToses, suicidal (or lytic) NETosis and vital NETosis
  • Suicidal NETosis mainly depends on the production of reactive oxygen species (ROS)
  • Since neutrophils die during this process, it is called suicidal NETosis.
  • vital NETosis
  • vital NETosis occurs independently of ROS production
  • Vital NETosis can be induced by Gram-negative bacteria. LPS
  • NETs are present in a variety of cancers, such as lung cancer, colon cancer, ovarian cancer, and leukemia
  • neutrophils actively undergo NETosis in the tumor microenvironment
  • Hypoxia
  • NETosis plays a pivotal role in noninfectious autoimmune diseases,
  • cytokines
  • tumor-derived proteases
  • tumor exosomes
  • NETosis generally actively progresses in the tumor microenvironment.
  • the proliferative cytokines TGFβ and IL-10 and the angiogenic factor VEGF are representative of neutrophil-derived tissue repair proteins.
  • NETosis is a defense system to protect the body from invading pathogens
  • when neutrophils are excessively stimulated, they produce excess NETs, thereby leading to pathological consequences
  • plasma levels of NETosis markers are elevated after major surgeries
  • local invasion, intravasation into the blood or lymphatic vessels, escape from the immune system, anchoring to capillaries in target organs, extravasation into the organs, transformation from dormant cells to proliferating cells, colonization to micrometastases, and growth to macrometastases
  • NETs promote metastasis at multiple steps
  • NETs loosen the ECM and capillary wall to promote the intravasation of cancer cells
  • NETs and platelets wrap CTCs, which protects them from attack by immune cells and shearing force by blood flow
  • NETs promote the local invasion of cancer cells by degrading the extracellular matrix (ECM)
  • neutrophil elastase, matrix metalloproteinase 9, and cathepsin G
  • NETs also promote the intravasation of cancer cells
  • millions of tumor cells are released into the circulation every day,
  • NETs can wrap up CTCs with platelets
  • β1-integrin plays an important role in the interaction between CTCs and NETs
  • NET-platelet-CTC aggregates.
  • After metastasizing to distant tissues, tumor cells are often found to remain dormant for a period of time and unexpectedly regrow late
  • NETs are believed to participate in the reactivation of dormant cancer cells in metastatic regions
  • NET-associated proteases NE and MMP-9 were found to be responsible for the reactivation of dormant cancer cells
  • Nathan Goodyear on 20 Apr 23
     
    Surgery induced metastasis: it is real and steered by NETosis.
Nathan Goodyear

Inflammatory cause of metabolic syndrome via brain stress and NF-κB - 0 views

www.ncbi.nlm.nih.gov/...PMC3314172

metabolic syndrome TLR cytokines hypothalamus brain neurology metabolic syndrome NF-kappaB DIO diet induced obesity over nutrition nutrition inflammation

shared by Nathan Goodyear on 09 Jul 13 - No Cached
  • Mechanistic studies further showed that such metabolic inflammation is related to the induction of various intracellular stresses such as mitochondrial oxidative stress, endoplasmic reticulum (ER) stress, and autophagy defect under prolonged nutritional excess
  • intracellular stress-inflammation process for metabolic syndrome has been established in the central nervous system (CNS) and particularly in the hypothalamus
  • the CNS and the comprised hypothalamus are known to govern various metabolic activities of the body including appetite control, energy expenditure, carbohydrate and lipid metabolism, and blood pressure homeostasis
  • ...56 more annotations...
  • Reactive oxygen species (ROS) refer to a class of radical or non-radical oxygen-containing molecules that have high oxidative reactivity with lipids, proteins, and nucleic acids
  • a large measure of intracellular ROS comes from the leakage of mitochondrial electron transport chain (ETC)
  • Another major source of intracellular ROS is the intentional generation of superoxides by nicotinamide adenine dinucleotide phosphate (NADPH) oxidase
  • there are other ROS-producing enzymes such as cyclooxygenases, lipoxygenases, xanthine oxidase, and cytochrome p450 enzymes, which are involved with specific metabolic processes
  • To counteract the toxic effects of molecular oxidation by ROS, cells are equipped with a battery of antioxidant enzymes such as superoxide dismutases, catalase, peroxiredoxins, sulfiredoxin, and aldehyde dehydrogenases
  • intracellular oxidative stress has been indicated to contribute to metabolic syndrome and related diseases, including T2D [72; 73], CVDs [74-76], neurodegenerative diseases [69; 77-80], and cancers
  • intracellular oxidative stress is highly associated with the development of neurodegenerative diseases [69] and brain aging
  • dietary obesity was found to induce NADPH oxidase-associated oxidative stress in rat brain
  • mitochondrial dysfunction in hypothalamic proopiomelanocortin (POMC) neurons causes central glucose sensing impairment
  • Endoplasmic reticulum (ER) is the cellular organelle responsible for protein synthesis, maturation, and trafficking to secretory pathways
  • unfolded protein response (UPR) machinery
  • ER stress has been associated to obesity, insulin resistance, T2D, CVDs, cancers, and neurodegenerative diseases
  • brain ER stress underlies neurodegenerative diseases
  • under environmental stress such as nutrient deprivation or hypoxia, autophagy is strongly induced to breakdown macromolecules into reusable amino acids and fatty acids for survival
  • intact autophagy function is required for the hypothalamus to properly control metabolic and energy homeostasis, while hypothalamic autophagy defect leads to the development of metabolic syndrome such as obesity and insulin resistance
  • prolonged oxidative stress or ER stress has been shown to impair autophagy function in disease milieu of cancer or aging
  • TLRs are an important class of membrane-bound pattern recognition receptors in classical innate immune defense
  • Most hypothalamic cell types including neurons and glia cells express TLRs
  • overnutrition constitutes an environmental stimulus that can activate TLR pathways to mediate the development of metabolic syndrome related disorders such as obesity, insulin resistance, T2D, and atherosclerotic CVDs
  • Isoforms TLR1, 2, 4, and 6 may be particularly pertinent to pathogenic signaling induced by lipid overnutrition
  • hypothalamic TLR4 and downstream inflammatory signaling are activated in response to central lipid excess via direct intra-brain lipid administration or HFD-feeding
  • overnutrition-induced metabolic derangements such as central leptin resistance, systemic insulin resistance, and weight gain
  • these evidences based on brain TLR signaling further support the notion that CNS is the primary site for overnutrition to cause the development of metabolic syndrome.
  • circulating cytokines can limitedly travel to the hypothalamus through the leaky blood-brain barrier around the mediobasal hypothalamus to activate hypothalamic cytokine receptors
  • significant evidences have been recently documented demonstrating the role of cytokine receptor pathways in the development of metabolic syndrome components
  • entral administration of TNF-α at low doses faithfully replicated the effects of central metabolic inflammation in enhancing eating, decreasing energy expenditure [158;159], and causing obesity-related hypertension
  • Resistin, an adipocyte-derived proinflammatory cytokine, has been found to promote hepatic insulin resistance through its central actions
  • both TLR pathways and cytokine receptor pathways are involved in central inflammatory mechanism of metabolic syndrome and related diseases.
  • In quiescent state, NF-κB resides in the cytoplasm in an inactive form due to inhibitory binding by IκBα protein
  • IKKβ activation via receptor-mediated pathway, leading to IκBα phosphorylation and degradation and subsequent release of NF-κB activity
  • Research in the past decade has found that activation of IKKβ/NF-κB proinflammatory pathway in metabolic tissues is a prominent feature of various metabolic disorders related to overnutrition
  • it happens in metabolic tissues, it is mainly associated with overnutrition-induced metabolic derangements, and most importantly, it is relatively low-grade and chronic
  • this paradigm of IKKβ/NF-κB-mediated metabolic inflammation has been identified in the CNS – particularly the comprised hypothalamus, which primarily accounts for to the development of overnutrition-induced metabolic syndrome and related disorders such as obesity, insulin resistance, T2D, and obesity-related hypertension
  • evidences have pointed to intracellular oxidative stress and mitochondrial dysfunction as upstream events that mediate hypothalamic NF-κB activation in a receptor-independent manner under overnutrition
  • In the context of metabolic syndrome, oxidative stress-related NF-κB activation in metabolic tissues or vascular systems has been implicated in a broad range of metabolic syndrome-related diseases, such as diabetes, atherosclerosis, cardiac infarct, stroke, cancer, and aging
  • intracellular oxidative stress seems to be a likely pathogenic link that bridges overnutrition with NF-κB activation leading to central metabolic dysregulation
  • overnutrition is an environmental inducer for intracellular oxidative stress regardless of tissues involved
  • excessive nutrients, when transported into cells, directly increase mitochondrial oxidative workload, which causes increased production of ROS by mitochondrial ETC
  • oxidative stress has been shown to activate NF-κB pathway in neurons or glial cells in several types of metabolic syndrome-related neural diseases, such as stroke [185], neurodegenerative diseases [186-188], and brain aging
  • central nutrient excess (e.g., glucose or lipids) has been shown to activate NF-κB in the hypothalamus [34-37] to account for overnutrition-induced central metabolic dysregulations
  • overnutrition can present the cell with a metabolic overload that exceeds the physiological adaptive range of UPR, resulting in the development of ER stress and systemic metabolic disorders
  • chronic ER stress in peripheral metabolic tissues such as adipocytes, liver, muscle, and pancreatic cells is a salient feature of overnutrition-related diseases
  • recent literature supports a model that brain ER stress and NF-κB activation reciprocally promote each other in the development of central metabolic dysregulations
  • when intracellular stresses remain unresolved, prolonged autophagy upregulation progresses into autophagy defect
  • autophagy defect can induce NF-κB-mediated inflammation in association with the development of cancer or inflammatory diseases (e.g., Crohn's disease)
  • The connection between autophagy defect and proinflammatory activation of NF-κB pathway can also be inferred in metabolic syndrome, since both autophagy defect [126-133;200] and NF-κB activation [20-33] are implicated in the development of overnutrition-related metabolic diseases
  • Both TLR pathway and cytokine receptor pathways are closely related to IKKβ/NF-κB signaling in the central pathogenesis of metabolic syndrome
  • Overnutrition, especially in the form of HFD feeding, was shown to activate TLR4 signaling and downstream IKKβ/NF-κB pathway
  • TLR4 activation leads to MyD88-dependent NF-κB activation in early phase and MyD88-indepdnent MAPK/JNK pathway in late phase
  • these studies point to NF-κB as an immediate signaling effector for TLR4 activation in central inflammatory response
  • TLR4 activation has been shown to induce intracellular ER stress to indirectly cause metabolic inflammation in the hypothalamus
  • central TLR4-NF-κB pathway may represent one of the early receptor-mediated events in overnutrition-induced central inflammation.
  • cytokines and their receptors are both upstream activating components and downstream transcriptional targets of NF-κB activation
  • central administration of TNF-α at low dose can mimic the effect of obesity-related inflammatory milieu to activate IKKβ/NF-κB proinflammatory pathways, furthering the development of overeating, energy expenditure decrease, and weight gain
  • the physiological effects of IKKβ/NF-κB activation seem to be cell type-dependent, i.e., IKKβ/NF-κB activation in hypothalamic agouti-related protein (AGRP) neurons primarily leads to the development of energy imbalance and obesity [34]; while in hypothalamic POMC neurons, it primarily results in the development of hypertension and glucose intolerance
  • the hypothalamus, is the central regulator of energy and body weight balance [
  • Nathan Goodyear on 09 Jul 13
     
    Great article chronicles the biochemistry of "over nutrition" and inflammation through NF-kappaB activation and its impact on the brain.
Nathan Goodyear

Oxidative stress, mitochondrial dysfunction and ce... [J Neurol Sci. 2005] - PubMed result - 0 views

www.ncbi.nlm.nih.gov/...15896810

CoQ10 mitochondria neurodegenerative disease Alzheimer's Parkinsons MS ALS oxidative stress

shared by Nathan Goodyear on 07 Feb 11 - No Cached
  • There is significant evidence that the pathogenesis of several neurodegenerative diseases, including Parkinson's disease, Alzheimer's disease, Friedreich's ataxia (FRDA), multiple sclerosis and amyotrophic lateral sclerosis, may involve the generation of reactive oxygen species (ROS) and/or reactive nitrogen species (RNS) associated with mitochondrial dysfunction
  • Nathan Goodyear on 07 Feb 11
     
    Mitochondrial dysfunction at heart of diseases such as Parkinson's, Alzheimers, MS, ALS..
Nathan Goodyear

ScienceDirect - 0 views

www.sciencedirect.com/...S2213231717309424

Cancer redox ROS reactive oxygen species RNS "reactive nitrogen species" NO eNOS iNOS nNOS catalase SOD

shared by Nathan Goodyear on 04 Dec 18 - No Cached
  • Nathan Goodyear on 04 Dec 18
     
    Great review of the redox system in cancer cells. Everybody focus' on the ROS, but forget about the RNS from NO. The current marketing pushes NO for CVD.
Nathan Goodyear

Oxidative Stress and Its Relationship With Adenosine Deaminase Activity in Various Stag... - 0 views

www.ncbi.nlm.nih.gov/...PMC3547448

Adenosine Deaminase ADA cancer breast cancer superoxide disumutase glutathione peroxidase oxidative stress inflammation

shared by Nathan Goodyear on 10 Nov 14 - No Cached
  • Reduced SOD activity might be responsible for excessive accumulation of superoxide anions leading to increased free radical mediated injury. Increased free radical production has been shown to be responsible for chromosomal damage leading to mutagenecity, cell proliferation and carcinogenesis. SOD activity showed marked improvement after mastectomy indicating the lowering of oxidative stress.
  • The increased production of reactive oxygen species causes oxidative stress leading to cell proliferation and hence increased inflammatory conditions
  • Superoxide dismutase is an important antioxidant enzyme which decomposes the harmful superoxide anions into hydrogen peroxide thus protects the body from the action of free radicals
  • ...20 more annotations...
  • Females suffering from breast cancer had significantly decreased Superoxide dismutase (SOD) and reduced glutathione (GSH) levels in comparison to normal females
  • ADA seems to be a promising marker of inflammation in breast cancer thereby suggesting that it can be used as a diagnostic tool to detect the stage of breast cancer along with cytopathological studies
  • In conclusion, our study confirmed the role of oxidative stress in the pathogenesis of breast cancer.
  • Another potent antioxidant molecule is reduced glutathione. It acts as reductant which converts hydrogen peroxide into water and reduces lipid peroxidation products into their corresponding alcohols and thus mediates protective action.
  • In the present study, significantly low SOD activity has been observed in female patients suffering from carcinoma breast both pre as well as post operative in comparison to healthy females.
  • We observed significantly decreased SOD activity and GSH levels in patients belonging to clinical stage 4 as compared to those having stages 1, 2 or 3 of breast cancer.
  • Increased ADA activity in breast cancer patients has also been reported
  • The compromised antioxidant defence system produces the oxidative stress which in turn creates the inflammatory response shown by concomitant increased adenosine deaminase (ADA) activity in female patients.
  • Experimental and epidemiological evidences implicate the involvement of oxygen derived free radical in the pathogenesis of breast cancer.
  • Antioxidant status was highly depressed in advanced stages of breast cancer as compared to initial stage.
  • In the present study, significantly low GSH levels were observed in female patients of carcinoma breast as compared to normal females
  • Walia et al. (1995) reported increased ADA activity in breast cancer patients as compared to age matched normal subjects.
  • These free radicals are able to cause damage to membrane, mitochondria and macromolecules including proteins, lipids and DNA and actively take part in cell proliferation. This cascade in turn generates the inflammatory response and causes the progression of the disease.
  • increased oxidative stress gives rise to inflammation which could further aggravates the disease
  • Breast carcinoma involves a cascade of events that are highly inflammatory.
  • Marked oxidative stress in stage 4 of breast cancer indicated advancement of the disease, hence checking oxidative stress at initial stage could be helpful for controlling the progression of the disease.
  • They concluded that ADA is a better probable parameter for detection of breast cancer
  • Adenosine deaminase enzyme (ADA) catalyzes the conversion of adenosine to inosine which finally gets converted to uric acid
  • serum ADA activity tends to increase with advancing age,
  • Prevalence of oxidative stress gives rise to inflammation.
  • Nathan Goodyear on 10 Nov 14
     
    Study finds a reduction in SuperOxide Dismutase and Glutathione Perioxidase in advancing breast cancer.  Cancer is a high oxidative stress disease that results in inflammation, mitochondrial dysfunction and proliferation.  Adenosine Deaminase (ADA) is proposed to be another biomarker to assess tumor stage.  
Nathan Goodyear

Vitamin C and cancer revisited - 0 views

www.ncbi.nlm.nih.gov/...PMC2516245

IV vitamin C cancer vitamin C H2O2 hydrogen peroxide Fe

shared by Nathan Goodyear on 05 Mar 18 - No Cached
  • It is well known that vitamin C, or ascorbic acid, is an effective biologic antioxidant and does not act as a pro-oxidant under normal conditions (5) because it does not readily autoxidize, i.e., react with oxygen (O2) to produce reactive oxygen species, such as superoxide radicals (O2•−) or H2O2
  • However, ascorbate readily donates an electron to redox-active transition metal ions, such as cupric (Cu2+) or ferric (Fe3+) ions, reducing them to cuprous (Cu+) and ferrous (Fe2+) ions, respectively
  • Reduced transition metal ions, in contrast to ascorbic acid, readily react with O2, reducing it to superoxide radicals (Reaction 2), which in turn dismutate to form H2O2 and O2
  • ...6 more annotations...
  • The H2O2 produced this way (Reactions 1–3) seems to be key to ascorbate's antitumor effect because H2O2 causes cancer cells to undergo apoptosis, pyknosis, and necrosis
  • In contrast, normal cells are considerably less vulnerable to H2O2
  • The reason for the increased sensitivity of tumor cells to H2O2 is not clear but may be due to lower antioxidant defenses
  • In fact, a lower capacity to destroy H2O2—e.g., by catalase, peroxiredoxins, and GSH peroxidases—may cause tumor cells to grow and proliferate more rapidly than normal cells in response to low concentrations of H2O2
  • These observations, combined with the inhibitory effect on xenograft growth, provide the proof of concept that millimolar concentrations of extracellular ascorbate, achievable by i.p. injection or i.v. infusion in experimental animals and humans, respectively, exert pro-oxidant, antitumor effects in vivo.
  • They also show that the concentration of the ascorbyl radical correlates with the concentration of H2O2 in interstitial fluid, whereas no H2O2 can be detected in blood or plasma
  • Nathan Goodyear on 05 Mar 18
     
    review of the mechanism of how extracellular AA, only obtainable from parenteral dosing, can produce H2O2 extracellularly to then be cytotoxic to cancer cells.
Nathan Goodyear

Induction of metastasis, cancer stem cell phenotype, and oncogenic metabolism in cancer... - 0 views

www.ncbi.nlm.nih.gov/...PMC5282724

EMT TME metastasis cancer stem cells cancer MMP2 Notch MMP-9 MMP-2 radioresistance Hedgehog CSC MMP9 Snail HIF-1alpha tumor microenvironment epithelial to mesenchymal transition TGF-beta radiation

shared by Nathan Goodyear on 09 Feb 21 - No Cached
  • More than half of cancer patients are treated with IR at some point during their treatment
  • fractionation schedule is the delivery of 1.8–2.0 Gy per day, five days per week
  • Nuclear DNA is the primary target of IR; it causes DNA damage (genotoxic stress) by direct DNA ionization
  • ...121 more annotations...
  • IR also indirectly induces DNA damage by stimulating reactive oxygen species (ROS) production
  • IR is known to induce EMT in vitro
  • p53 is activated in response to IR-induced DNA damage
  • IR paradoxically also promotes tumour recurrence and metastasis
  • DNA double-strand breaks (DSBs)
  • cancer cells undergoing EMT acquire invasive and metastatic properties
  • changes in the tumour microenvironment (TME)
  • IR seems to induce EMT and CSC phenotypes by regulating cellular metabolism
  • EMT, stemness, and oncogenic metabolism are known to be associated with resistance to radiotherapy and chemotherapy
  • Hanahan and Weinberg proposed ten hallmarks of cancer that alter cell physiology to enhance malignant growth: 1) sustained proliferation, 2) evasion of growth suppression, 3) cell death resistance, 4) replicative immortality, 5) evasion of immune destruction, 6) tumour-promoting inflammation, 7) activation of invasion and metastasis, 8) induction of angiogenesis, 9) genome instability, and 10) alteration of metabolism
  • EMT is a developmental process that plays critical roles in embryogenesis, wound healing, and organ fibrosis
  • IR is known to induce stemness and metabolic alterations in cancer cells
  • transforming growth factor-β [TGF-β], epidermal growth factor [EGF]) and their associated signalling proteins (Wnt, Notch, Hedgehog, nuclear-factor kappa B [NF-κB], extracellular signal-regulated kinase [ERK], and phosphatidylinositol 3-kinase [PI3K]/Akt
  • activate EMT-inducing transcription factors, including Snail/Slug, ZEB1/δEF1, ZEB2/SIP1, Twist1/2, and E12/E47
  • Loss of E-cadherin is considered a hallmark of EMT
  • IR has been shown to induce EMT to enhance the motility and invasiveness of several cancer cells, including those of breast, lung, and liver cancer, and glioma cells
  • IR may increase metastasis in both the primary tumour site and in normal tissues under some circumstance
  • sublethal doses of IR have been shown to enhance the migratory and invasive behaviours of glioma cells
  • ROS are known to play an important role in IR-induced EMT
  • High levels of ROS trigger cell death by causing irreversible damage to cellular components such as proteins, nucleic acids, and lipids, whereas low levels of ROS have been shown to promote tumour progression—including tumour growth, invasion, and metastasis
  • hypoxia-inducible factor-1 (HIF-1) is involved in IR-induced EMT
  • Treatment with the N-acetylcysteine (NAC), a general ROS scavenger, prevents IR-induced EMT, adhesive affinity, and invasion of breast cancer cells
    • Nathan Goodyear
      Nathan Goodyear on 09 Feb 21
       
      NAC for all patients receiving radiation therapy
  • Snail has been shown to play a crucial role in IR-induced EMT, migration, and invasion
  • IR activates the p38 MAPK pathway, which contributes to the induction of Snail expression to promote EMT and invasion
  • NF-κB signalling that promotes cell migration
  • ROS promote EMT to allow cancer cells to avoid hostile environments
  • HIF-1 is a heterodimer composed of an oxygen-sensitive α subunit and a constitutively expressed β subunit.
  • Under normoxia, HIF-1α is rapidly degraded, whereas hypoxia induces stabilisation and accumulation of HIF-1α
  • levels of HIF-1α mRNA are enhanced by activation of the PI3K/Akt/mammalian target of rapamycin (mTOR)
  • IR is known to increase stabilisation and nuclear accumulation of HIF-1α, since hypoxia is a major condition for HIF-1 activation
  • IR induces vascular damage that causes hypoxia
  • ROS is implicated in IR-induced HIF-1 activation
  • IR causes the reoxygenation of hypoxic cancer cells to increase ROS production, which leads to the stabilisation and nuclear accumulation of HIF-1
  • IR increases glucose availability under reoxygenated conditions that promote HIF-1α translation by activating the Akt/mTOR pathway
  • The stabilised HIF-1α then translocates to the nucleus, dimerizes with HIF-1β, and increases gene expression— including the expression of essential EMT regulators such as Snail—to induce EMT, migration, and invasion
  • TGF-β signalling has been shown to play a crucial role in IR-induced EMT
  • AP-1 transcription factor is involved in IR-induced TGF-β1 expression
  • Wnt/β-catenin signalling is also implicated in IR-induced EMT
  • Notch signalling is known to be involved in IR-induced EMT
  • IR also increases Notch-1 expression [99]. Notch-1 is known to induce EMT by upregulating Snail
  • PAI-1 signalling is also implicated in IR-induced Akt activation that increases Snail levels to induce EMT
  • EGFR activation is known to be associated with IR-induced EMT, cell migration, and invasion by activating two downstream pathways: PI3K/Akt and Raf/MEK/ERK
  • ROS and RNS are also implicated in IR-induced EGFR activation
  • IR has also been shown to activate Hedgehog (Hh) signalling to induce EMT
  • IR has been shown to induce Akt activation through several signalling pathways (EGFR, C-X-C chemokine receptor type 4 [CXCR4]/C-X-C motif chemokine 12 [CXCL12], plasminogen activator inhibitor 1 [PAI-1]) and upstream regulators (Bmi1, PTEN) that promote EMT and invasion
  • CSCs possess a capacity for self-renewal, and they can persistently proliferate to initiate tumours upon serial transplantation, thus enabling them to maintain the whole tumour
  • Conventional cancer treatments kill most cancer cells, but CSCs survive due to their resistance to therapy, eventually leading to tumour relapse and metastasis
  • identification of CSCs, three types of markers are utilised: cell surface molecules, transcription factors, and signalling pathway molecules
  • CSCs express distinct and specific surface markers; commonly used ones are CD24, CD34, CD38, CD44, CD90, CD133, and ALDH
  • Transcription factors, including Oct4, Sox2, Nanog, c-Myc, and Klf4,
  • signalling pathways, including those of TGF-β, Wnt, Hedgehog, Notch, platelet-derived growth factor receptor (PDGFR), and JAK/STAT
  • microRNAs (miRNAs), including let-7, miR-22, miR-34a, miR-128, the miR-200 family, and miR-451
  • Non-CSCs can be reprogrammed to become CSCs by epigenetic and genetic changes
  • EMT-inducing transcription factors, such as Snail, ZEB1, and Twist1, are known to confer CSC properties
  • Signalling pathways involved in EMT, including those of TGF-β, Wnt, and Notch, have been shown to play important roles in inducing the CSC phenotype
  • TGF-β1 not only increases EMT markers (Slug, Twist1, β-catenin, N-cadherin), but also upregulates CSC markers (Oct4, Sox2, Nanog, Klf4) in breast and lung cancer cells
  • some CSC subpopulations arise independently of EMT
  • IR has been shown to induce the CSC phenotype in many cancers, including breast, lung, and prostate cancers, as well as melanoma
  • Genotoxic stress due to IR or chemotherapy promotes a CSC-like phenotype by increasing ROS production
  • IR has been shown to induce reprogramming of differentiated cancer cells into CSCs
  • In prostate cancer patients, radiotherapy increases the CD44+ cell population that exhibit CSC properties
  • IR also induces the re-expression of stem cell regulators, such as Sox2, Oct4, Nanog, and Klf4, to promote stemness in cancer cells
  • EMT-inducing transcription factors and signalling pathways, including Snail, STAT3, Notch signalling, the PI3K/Akt pathway, and the MAPK cascade, have been shown to play important roles in IR-induced CSC properties
  • STAT3 directly binds to the Snail promoter and increases Snail transcription, which induces the EMT and CSC phenotypes, in cisplatin-selected resistant cells
  • Other oncogenic metabolic pathways, including glutamine metabolism, the pentose phosphate pathway (PPP), and synthesis of fatty acids and cholesterol, are also enhanced in many cancers
  • metabolic reprogramming
  • HIF-1α, p53, and c-Myc, are known to contribute to oncogenic metabolism
  • metabolic reprogramming
  • tumour cells exhibit high mitochondrial metabolism as well as aerobic glycolysis
  • occurring within the same tumour
  • CSCs can be highly glycolytic-dependent or oxidative phosphorylation (OXPHOS)-dependen
  • mitochondrial function is crucial for maintaining CSC functionality
  • cancer cells depend on mitochondrial metabolism and increase mitochondrial production of ROS that cause pseudo-hypoxia
  • HIF-1 then enhances glycolysis
  • CAFs have defective mitochondria that lead to the cells exhibiting the Warburg effect; the cells take up glucose, and then secrete lactate to 'feed' adjacent cancer cells
  • lactate transporter, monocarboxylate transporter (MCT)
  • nutrient microenvironment
  • Epithelial cancer cells express MCT1, while CAFs express MCT4. MCT4-positive, hypoxic CAFs secrete lactate by aerobic glycolysis, and MCT1-expressing epithelial cancer cells then uptake and use that lactate as a substrate for the tricarboxylic acid (TCA) cycle
  • MCT4-positive cancer cells depend on glycolysis and then efflux lactate, while MCT1-positive cells uptake lactate and rely on OXPHOS
  • metabolic heterogeneity induces a lactate shuttle between hypoxic/glycolytic cells and oxidative/aerobic tumour cells
  • bulk tumour cells exhibit a glycolytic phenotype, with increased conversion of glucose to lactate (and enhanced lactate efflux through MCT4), CSC subsets depend on oxidative phosphorylation; most of the glucose entering the cells is converted to pyruvate to fuel the TCA cycle and the electron transport chain (ETC), thereby increasing mitochondrial ROS production
  • the major fraction of glucose is directed into the pentose phosphate pathway, to produce redox power through the generation of NADPH and ROS scavengers
  • HIF-1α, p53, and c-Myc, are known to contribute to oncogenic metabolism
  • regulatory molecules involved in EMT and CSCs, including Snail, Dlx-2, HIF-1, STAT3, TGF-β, Wnt, and Akt, are implicated in the metabolic reprogramming of cancer cells
  • HIF-1 induces the expression of glycolytic enzymes, including the glucose transporter GLUT, hexokinase, lactate dehydrogenase (LDH), and MCT, resulting in the glycolytic switch
  • HIF-1 represses the expression of pyruvate dehydrogenase kinase (PDK), which inhibits pyruvate dehydrogenase (PDH), thereby inhibiting mitochondrial activity
  • STAT3 has been implicated in EMT-induced metabolic changes as well
  • TGF-β and Wnt play important roles in the metabolic alteration of cancer cells
  • Akt is also implicated in the glycolytic switch and in promoting cancer cell invasiveness
  • EMT, invasion, metastasis, and stemness
  • pyruvate kinase M2 (PKM2), LDH, and pyruvate carboxylase (PC), are implicated in the induction of the EMT and CSC phenotypes
  • decreased activity of PKM2 is known to promote an overall shift in metabolism to aerobic glycolysis
  • LDH catalyses the bidirectional conversion of lactate to pyruvate
  • High levels of LDHA are positively correlated with the expression of EMT and CSC markers
  • IR has been shown to induce metabolic changes in cancer cells
  • IR enhances glycolysis by upregulating GAPDH (a glycolysis enzyme), and it increases lactate production by activating LDHA, which converts pyruvate to lactate
  • IR enhances glycolysis by upregulating GAPDH (a glycolysis enzyme), and it increases lactate production by activating LDHA, which converts pyruvate to lactate
  • IR also elevates MCT1 expression that exports lactate into the extracellular environment, leading to acidification of the tumour microenvironment
  • IR increases intracellular glucose, glucose 6-phosphate, fructose, and products of pyruvate (lactate and alanine), suggesting a role for IR in the upregulation of cytosolic aerobic glycolysis
  • Lactate can activate latent TGF-
  • lactate stimulates cell migration and enhances secretion of hyaluronan from CAF that promote tumour metastasis
  • promote tumour survival, growth, invasion, and metastasis; enhance the stiffness of the ECM; contribute to angiogenesis; and induce inflammation by releasing several growth factors and cytokines (TGF-β, VEGF, hepatocyte growth factor [HGF], PDGF, and stromal cell-derived factor 1 [SDF1]), as well as MMP
  • tumours recruit the host tissue’s blood vessel network to perform four mechanisms: angiogenesis (formation of new vessels), vasculogenesis (de novo formation of blood vessels from endothelial precursor cells), co-option, and modification of existing vessels within tissues.
  • immunosuppressive cells such as tumour-associated macrophages (TAM), MDSCs, and regulatory T cells, and the immunosuppressive cytokines, TGF-β and interleukin-10 (IL-10)
  • immunosuppressive cells such as tumour-associated macrophages (TAM), MDSCs, and regulatory T cells, and the immunosuppressive cytokines, TGF-β and interleukin-10 (IL-10)
  • intrinsic immunogenicity or induce tolerance
  • cancer immunoediting’
  • three phases: 1) elimination, 2) equilibrium, and 3) escape.
  • The third phase, tumour escape, is mediated by antigen loss, immunosuppressive cells (TAM, MDSCs, and regulatory T cells), and immunosuppressive cytokines (TGF-β and IL-10).
  • IR can elicit various changes in the TME, such as CAF activity-mediated ECM remodelling and fibrosis, cycling hypoxia, and an inflammatory response
  • IR activates CAFs to promote the release of growth factors and ECM modulators, including TGF-β and MMP
  • TGF-β directly influences tumour cells and CAFs, promotes tumour immune escape, and activates HIF-1 signalling
    • Nathan Goodyear
      Nathan Goodyear on 09 Feb 21
       
      And now the receipts
  • MMPs degrade ECM that facilitates angiogenesis, tumour cell invasion, and metastasis
    • Nathan Goodyear
      Nathan Goodyear on 09 Feb 21
       
      Receipts and mechanisms
  • IR also promotes MMP-2/9 activation in cancer cells to promote EMT, invasion, and metastasis
  • IR-induced Snail increases MMP-2 expression to promote EMT
  • Radiotherapy has the paradoxical side-effect of increasing tumour aggressiveness
  • IR promotes ROS production in cancer cells, which may induce the activation of oncogenes and the inactivation of tumour suppressors, which further promote oncogenic metabolism
  • Metabolic alterations
  • oncogenic metabolism
  • elicit various changes in the TME
  • Although IR activates an antitumour immune response, this signalling is frequently suppressed by tumour escape mechanisms
  • Nathan Goodyear on 09 Feb 21
     
    Important review article.
Nathan Goodyear

Stuck at the bench: Potential natural neuroprotective compounds for concussion - 0 views

www.ncbi.nlm.nih.gov/...PMC3205506

concussions concussion natural therapies brain curcumin omega 3 resveratrol green tea EGCG EPA DHA vitamin E vitamin c vitamin D

shared by Nathan Goodyear on 20 Feb 16 - No Cached
  • Long-chain polyunsaturated fatty acids, including eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA), are highly enriched in neuronal synaptosomal plasma membranes and vesicles
  • The predominant CNS polyunsaturated fatty acid is DHA
  • effective supplementation and/or increased ingestion of dietary sources rich in EPA and DHA, such as cold-water fish species and fish oil, may help improve a multitude of neuronal functions, including long-term potentiation and cognition.
  • ...45 more annotations...
  • multiple preclinical studies have suggested that DHA and/or EPA supplementation may have potential benefit through a multitude of diverse, but complementary mechanisms
  • pre-injury dietary supplementation with fish oil effectively reduces post-traumatic elevations in protein oxidation
  • The benefits of pre-traumatic DHA supplementation have not only been independently confirmed,[150] but DHA supplementation has been shown to significantly reduce the number of swollen, disconnected and injured axons when administered following traumatic brain injury.
  • DHA has provided neuroprotection in experimental models of both focal and diffuse traumatic brain injury
  • potential mechanisms of neuroprotection, in addition to DHA and EPA's well-established anti-oxidant and anti-inflammatory properties
  • Despite abundant laboratory evidence supporting its neuroprotective effects in experimental models, the role of dietary DHA and/or EPA supplementation in human neurological diseases remains uncertain
  • Several population-based, observational studies have suggested that increased dietary fish and/or omega-3 polyunsaturated fatty acid consumption may reduce risk for ischemic stroke in several populations
  • Randomized control trials have also demonstrated significant reductions in ischemic stroke recurrence,[217] relative risk for ischemic stroke,[2] and reduced incidence of both symptomatic vasospasm and mortality following subarachnoid hemorrhage
  • Clinical trials in Alzheimer's disease have also been largely ineffective
  • The clinical evidence thus far appears equivocal
  • curcumin has gained much attention from Western researchers for its potential therapeutic benefits in large part due to its potent anti-oxidant[128,194,236] and anti-inflammatory properties
  • Curcumin is highly lipophilic and crosses the blood-brain barrier enabling it to exert a multitude of different established neuroprotective effects
  • in the context of TBI, a series of preclinical studies have suggested that pre-traumatic and post-traumatic curcumin supplementation may bolster the brain's resilience to injury and serve as a valuable therapeutic option
  • Curcumin may confer significant neuroprotection because of its ability to act on multiple deleterious post-traumatic, molecular cascades
  • studies demonstrated that both pre- and post-traumatic curcumin administration resulted in a significant reduction of neuroinflammation via inhibition of the pro-inflammatory molecules interleukin 1β and nuclear factor kappa B (NFκB)
  • no human studies have been conducted with respect to the effects of curcumin administration on the treatment of TBI, subarachnoid or intracranial hemorrhage, epilepsy or stroke
  • studies have demonstrated that resveratrol treatment reduces brain edema and lesion volume, as well as improves neurobehavioral functional performance following TBI
  • green tea consumption or supplementation with its derivatives may bolster cognitive function acutely and may slow cognitive decline
  • At least one population based study, though, did demonstrate that increased green tea consumption was associated with a reduced risk for Parkinson's disease independent of total caffeine intake
  • a randomized, placebo-controlled trial demonstrated that administration of green tea extract and L-theanine, over 16 weeks of treatment, improved indices of memory and brain theta wave activity on electroencephalography, suggesting greater cognitive alertness
  • Other animal studies have also demonstrated that theanine, another important component of green tea extract, exerts a multitude of neuroprotective benefits in experimental models of ischemic stroke,[63,97] Alzheimer's disease,[109] and Parkinson's disease
  • Theanine, like EGCG, contains multiple mechanisms of neuroprotective action including protection from excitotoxic injury[97] and inhibition of inflammation
  • potent anti-oxidant EGCG which is capable of crossing the blood-nerve and blood-brain barrier,
  • Epigallocatechin-3-gallate also displays neuroprotective properties
  • More recent research has suggested that vitamin D supplementation and the prevention of vitamin D deficiency may serve valuable roles in the treatment of TBI and may represents an important and necessary neuroprotective adjuvant for post-TBI progesterone therapy
  • Progesterone is one of the few agents to demonstrate significant reductions in mortality following TBI in human patients in preliminary trials
  • in vitro and in vivo studies have suggested that vitamin D supplementation with progesterone administration may significantly enhance neuroprotection
  • Vitamin D deficiency may increase inflammatory damage and behavioral impairment following experimental injury and attenuate the protective effects of post-traumatic progesterone treatment.[37]
  • emerging evidence has suggested that daily intravenous administration of vitamin E following TBI significantly decreases mortality and improves patient outcomes
  • high dose vitamin C administration following injury stabilized or reduced peri-lesional edema and infarction in the majority of patients receiving post-injury treatment
  • it has been speculated that combined vitamin C and E therapy may potentiate CNS anti-oxidation and act synergistically with regards to neuroprotection
  • one prospective human study has found that combined intake of vitamin C and E displays significant treatment interaction and reduces the risk of stroke
  • Pycnogenol has demonstrated the ability to slow or reduce the pathological processes associated with Alzheimer's disease
  • Pcynogenol administration, in a clinical study of elderly patients, led to improved cognition and reductions in markers of lipid peroxidase
  • One other point of consideration is that in neurodegenerative disease states like Alzheimer's disease and Parkinson's disease, where there are high levels of reactive oxygen species generation, vitamin E can tend to become oxidized itself. For maximal effectiveness and to maintain its anti-oxidant capacity, vitamin E must be given in conjunction with other anti-oxidants like vitamin C or flavonoids
  • These various factors might account for the null effects of alpha-tocopherol supplementation in patients with MCI and Alzheimer's disease
  • preliminary results obtained in a pediatric population have suggested that post-traumatic oral creatine administration (0.4 g/kg) given within four hours of traumatic brain injury and then daily thereafter, may improve both acute and long-term outcomes
  • Acutely, post-traumatic creatine administration seemed to reduce duration of post-traumatic amnesia, length of time spent in the intensive care unit, and duration of intubation
  • At three and six months post-injury, subjects in the creatine treatment group demonstrated improvement on indices of self care, communication abilities, locomotion, sociability, personality or behavior and cognitive function when compared to untreated controls
  • patients in the creatine-treatment group were less likely to experience headaches, dizziness and fatigue over six months of follow-up
  • CNS creatine is derived from both its local biosynthesis from the essential amino acids methionine, glycine and arginine
  • Studies of patients with CNS creatine deficiency and/or murine models with genetic ablation of creatine kinase have consistently demonstrated significant neurological impairment in the absence of proper creatine, phosphocreatine, or creatine kinase function; thus highlighting its functional importance
  • chronic dosing may partially reverse neurological impairments in human CNS creatine deficiency syndromes
  • Several studies have suggested that creatine supplementation may also reduce oxidative DNA damage and brain glutamate levels in Huntington disease patients
  • Another study highlighted that creatine supplementation marginally improved indices of mood and reduced the need for increased dopaminergic therapy in patients with Parkinson's disease
  • Nathan Goodyear on 20 Feb 16
     
    great review of natural therapies in the treatment of concussions
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