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nidthamsirisup

Epigenetics Seeks Clues to Mental Illness in Genes' Life Story - Science in 2011 - NYTi... - 0 views

www.nytimes.com/...09brain.html

epigenetics DNA Genes disease

shared by nidthamsirisup on 15 Apr 12 - No Cached
  • epigenetics, the study of how people’s experience and environment affect the function of their genes.
  • Studies suggest that such add-on, or epigenetic, markers develop as an animal adapts to its environment, whether in the womb or out in the world — and the markers can profoundly affect behavior.
  • In studies of rats, researchers have shown that affectionate mothering alters the expression of genes, allowing them to dampen their physiological response to stress. These biological buffers are then passed on to the next generation: rodents and nonhuman primates biologically primed to handle stress tend to be more nurturing to their own offspring, and the system is thought to work similarly in humans.
  • ...3 more annotations...
  • the offspring of parents who experience famine are at heightened risk for developing schizophrenia, some research suggests — perhaps because of the chemical signatures on the genes that parents pass on.
  • in some people with autism, epigenetic markers had silenced the gene which makes the receptor for the hormone oxytocin. Oxytocin oils the brain’s social circuits, and is critical in cementing relationships; a brain short on receptors for it would most likely struggle in social situations.
  • In one large study of people with schizophrenia, researchers at Johns Hopkins are analyzing blood and other data to see whether the degree of epigenetic variation is related to the inherited risk of developing the disorder. In another, researchers at Tufts are studying the genes of animals dependent on opiates to see how epigenetic alterations caused by drug exposure affect the opiate sensitivity of the animals’ offspring.
chanon chiarnpattanodom

Cancer epigenetics takes center stage - 1 views

www.pnas.org/...392.full

shared by chanon chiarnpattanodom on 16 Apr 12 - No Cached
    • chanon chiarnpattanodom
      chanon chiarnpattanodom on 16 Apr 12
       
      DNA methylation is a chemical process where a methyl group is added on either the cytosine ring or the adenine ring, used in "higher leveled" organisms. Important in cell differentiation since methylation will cause cells to "remember" and remain differenciated instead of expressing other genes. 
  • Epigenetics is defined as modifications of the genome, heritable during cell division, that do not involve a change in the DNA sequence.
  • Epigenetic alterations in cancer include global hypomethylation
  • ...18 more annotations...
  • the promoters of housekeeping genes that are generally protected from methylation.
  • may lead to aberrant silencing of tumor suppressor genes
  • discovered loss of imprinting (LOI) in cancer
  • Genomic imprinting, the subject of the report by Nakagawa et al. (2), is an epigenetic modification of a specific parental allele of a gene, or the chromosome on which it resides, in the gamete or zygote, leading to differential expression of the two alleles of the gene in somatic cells of the offspring.
  • we found that LOI can occur in the normal colonic mucosa of colorectal cancer patients with LOI in their tumors
  • This LOI was linked to cases showing microsatellite instability (MSI) in the tumors
  • However, these patients do not have mutations in mismatch repair genes
  • One potential cause of MSI in these sporadic cancers is hypermethylation and epigenetic silencing of the hMLH1 mismatch repair gene
  • Nakagawa et al. (2) now confirm the original study of Cui et al. that LOI occurs in both tumor and normal tissue of patients
  • The present study (2) also offers an intriguing mechanistic hypothesis to explain the relationship between H19 DMR methylation and LOI in these patients
  • Nevertheless, the study calls attention to this remarkable highly conserved multifunctional protein,
  • The potential link to CTCF suggested by this study also calls our attention to the link among DNA methylation, epigenetics, and chromatin.
  • A clue to the link between MSI and epigenetics may be provided by another sometimes overlooked common thread in epigenetics, namely DNA replication
  • repeat-induced gene silencing is thought to be propagated through hemimethylated intermediates during DNA replication
  • The studies of Cui et al. (11), Nishihara et al. (20), and Nakagawa et al. (2) suggest a new and provocative view of the timing of epigenetic changes in cancer.
  • Studies of transgenic mice with constitutive biallelic expression of IGF2, comparable to LOI, show reduced apoptosis and increased tumor formation
  • I conclude by noting that the distinction between cancer genetics and epigenetics has blurred considerably in recent years
  • Many conventional “genetic” mechanisms directly affect proteins that regulate chromatin,
Sasicha Manupipatpong

Divergent evolution illuminated: Light shed on reasons behind genome differences betwee... - 0 views

www.sciencedaily.com/...120329124607.htm

trna dna evolution genome differences proteins biotechnology

shared by Sasicha Manupipatpong on 01 Apr 12 - No Cached
  • divergent evolution of the genomes of different groups of species
  • three large domains: Archaea, Bacteria and Eukarya
  • genomes of each group have evolved towards distinct structures that have favored their separation
  • ...15 more annotations...
  • connection between the function of enzymes and the composition of the genomes shed light on the evolution and structure of genes
  • analyzed the distribution and abundance of transfer RNA genes
  • structure of genomes was adapted to the activity of some enzymes, which differ for Bacteria and for Eukarya and are absent in Archaea
  • activity of these enzymes modifies tRNAs, allowing them to recognize up to three distinct codons
    • Sasicha Manupipatpong
      Sasicha Manupipatpong on 01 Apr 12
       
      Prior to the study, it was understood that tRNA's have a specific anti-codon sequence which would recognize a single mRNA codon with the complementary sequence. Does this mean that the tRNA also attaches to different amino acids as well? How does the tRNA differentiate between the different amino acids it is at that moment carrying and the codon it matches with on the mRNA--does it change shape according to which amino acid is attached to it?
  • activity of the bacterial and eukaryal enzymes is different, which explains why the genomes and the gene composition of bacteria, eukarya, and archaea have diverged
  • relation between genome structure and the speed of protein synthesis from its genes
  • demonstrates how organisms have evolved in a different manner to achieve better adaptations and to have optimum protein translation efficiency
  • biotechnology as the discovery of the relevance of these modifications will allow an improvement in the industrial production of proteins
  • another parameter with which to optimize the synthesis of proteins from a gene
  • human insulin is "manufactured" in bacteria and our discovery would allow this production to be increased if we take into account the activity of these enzymes
  • relevant for the study of cancer: "it is possible that these modification enzymes are over-represented in some kinds of cancer. In fact, this would be logical because cancer cells are highly efficient in producing proteins."
  • greater the abundance of a protein in a cell the higher the number of triplets found in its gene sequence that can be read by modified tRNAs
  • don't exactly know why these enzymes appear or why they are different in bacteria and in eukaryotes but it's clear that they contribute to the separation of genomes of these two groups
  • genetic code is the same
  • what has changed is the relative importance of different codons of the code
  • Sasicha Manupipatpong on 01 Apr 12
     
    A recent study uncovers the reasons for the divergent evolution of the genomes of different species. The findings provide information about tRNA modifications which may prove useful in the field of biotechnology, specifically in the industrial production of proteins
Changul Louis Yeum

Study Says DNA's Power to Predict Illness Is Limited - 0 views

www.nytimes.com/...ct-is-limited-study-finds.html

DNA disease research gene

shared by Changul Louis Yeum on 11 Apr 12 - No Cached
  • Changul Louis Yeum on 11 Apr 12
     
    The answer, according to a new study of twins, is, for the most part, "no." While sequencing the entire DNA of individuals is proving fantastically useful in understanding diseases and finding new treatments, it is not a method that will, for the most part, predict a person's medical future.
Mickey Tsai

Niceness a combination of genetics and environment, the Neurogenics of Niceness study f... - 0 views

www.heraldsun.com.au/...story-fn7x8me2-1226324345541

genetics environment research

shared by Mickey Tsai on 14 Apr 12 - No Cached
  • BEING a nice person could come down to having a good set of genes
  • "kind" behaviour of more than 700 individuals was partly linked to receptor genes for oxytocin and vasopressin.
  • uch of the hormone you have, it's how responsive your brain is to the hormo
  • ...2 more annotations...
  • It's not about how much of the hormone you have, it's how responsive your brain is to the hormones
  • "(Niceness) is a combination of genetics and your environment."
  • Mickey Tsai on 14 Apr 12
     
    A study shows that genetics could play a role in determining "niceness". The kind behavior is found to be linked to receptor genes for oxytopic and vasopressin. People that are more responsive to it are more inclined to donate money, pay taxes, give blood, report crime etc. It isn't about how much of the hormone you have but how responsive you are to it. Of course genetics isnt the only factor, if you are surrounded by nice people it is likely that it would rub off on you.
chanon chiarnpattanodom

Genes an Important Factor in Urinary Incontinence - 1 views

Scientists have studied how much is urinary incontinence controlled by genetics, rather than the environment by observing twins. 

Urinary Incontinence Genes

shared by chanon chiarnpattanodom on 11 Apr 12 - No Cached
  • chanon chiarnpattanodom on 11 Apr 12
     
    Scientists have studied how much is urinary incontinence controlled by genetics, rather than the environment by observing twins. 
Nitchakan Chaiprukmalakan

Biotechdaily - Low MicroRNA Activity Characterizes Inflamed Lung Tissues - 0 views

www.biotechdaily.com/...zes_inflamed_lung_tissues.html

shared by Nitchakan Chaiprukmalakan on 13 Apr 12 - No Cached
  • A recent study examined the interaction between a specific microRNA (miRNA) and the activity of the inflammatory cytokine interleukin 13 (IL-13).
  • In the current study, investigators at the Cincinnati Children's Hospital Medical Center (Ohio, USA) examined the effect that stimulation of IL-13 activity has on microRNAs, particularly miR-375
  • They reported in the March 28, 2012, online edition of the journal Mucosal Immunology that IL-13 induced changes in epithelial gene and protein expression including the consistent downregulation of miR-375 in IL-13 stimulated human esophageal squamous and bronchial epithelial cells.
  • ...3 more annotations...
  • Analysis of miR-375 levels in a human disease characterized by IL-13 overproduction - the allergic disorder eosinophilic esophagitis (EE) - revealed downregulation of miR-375 in EE patient samples compared with control patients. Low levels of miR-375 expression levels indicated disease activity.
  • “MiR-375 is proof of principle that microRNAs are involved in fine-tuning IL-13-mediated responses, which opens up a set of new possibilities for novel therapeutic targets for treatment of allergic disease.”
  • “The identification of a microRNA that regulates IL-13-induced changes and inflammatory pathways is a significant advancement for the understanding and future treatment of allergic disease,
Nitchakan Chaiprukmalakan

New study: Tracking proteins that repair DNA - 0 views

scitechstory.com/...cking-proteins-that-repair-dna

shared by Nitchakan Chaiprukmalakan on 13 Apr 12 - No Cached
  • DNA damage could be caused by many things including toxins, radiation, or a failure in molecular chemistry. If it happens in one cell, the damage may do nothing, or at worse cause the cell to die. If damage occurs in a reproductive cell (a zygote) it can be an inherited mutation; the consequences of which can go on for generations
  • The DNA repair workers are (so far as we know) protein molecules.
  • Under microscopic observations it was seen that the UvrA protein randomly jumps from one DNA molecule to the next, staying about 7 seconds before moving on. However, when UvrA formed a complex with two UvrB molecules (UvrAB), the search became more sophisticated and slower. The complex would slide along the DNA strand for as long as 40 seconds before moving to another molecule. Sometimes it was observed that the UvrAB motion would ‘pause,’ apparently checking for structural abnormalities that might indicate DNA damage.
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  • It’s assumed the protein complex is analyzing, but the mechanism of analysis is unknown. It’s also unknown if the UvrAB complex (or similar complex) actually does the repair, or if it signals for some other protein complex(es) to make the repair.
nidthamsirisup

Study suggests why some animals live longer - 1 views

www.physorg.com/...2012-03-animals-longer.html

animals dna project genetics

shared by nidthamsirisup on 02 Apr 12 - No Cached
    • nidthamsirisup
      nidthamsirisup on 02 Apr 12
       
      A new method to detect proteins associated with longevity which helps further our understanding into why some animals live longer than others.
  • The study, led by Dr. Joao Pedro Magalhaes and postgraduate student, Yang Li, is the first to show evolutionary patterns in biological repair systems in long-lived animals and could, in the future, be used to help develop anti-ageing interventions by identifying proteins in long-lived species that better respond to, for example, DNA damage
  • these species have optimised pathways that repair molecular damage, compared to shorter-lived animals, such as mice
  • ...4 more annotations...
  • found a similar pattern in proteins associated with metabolism, cholesterol and pathways involved in the recycling of proteins
  • Proteins associated with the degradation of damaged proteins, a process that has been connected to ageing, were also linked with the evolution of longevity in mammals.
  • If we can identify the proteins that allow some species to live longer than others we could use this knowledge to improve human health and slow the ageing process.
  • “We developed a method to detect proteins whose molecular evolution correlates with longevity of a species. The proteins we detected changed in a particular pattern, suggesting that evolution of these proteins was not by accident, but rather by design to cope with the biological processes impacted by ageing, such as DNA damage. The results suggest that long-lived animals were able to optimise bodily repair which will help them fend off the ageing process.”
Pop karnchanapimonkul

Study Identifies Genetic Regulators Hijacked By Avian And Swine Flu Viruses - 0 views

www.medicalnewstoday.com/...243562.php

study swine flu viruses

shared by Pop karnchanapimonkul on 02 Apr 12 - No Cached
  • Pop karnchanapimonkul on 02 Apr 12
     
    Genes and Swine Flu
Pop karnchanapimonkul

Genetic adaptation of fat metabolism key to development of human brain - 0 views

www.sciencedaily.com/...120412133056.htm

adaptation fat metabolism brain human gene

shared by Pop karnchanapimonkul on 13 Apr 12 - No Cached
  • 300,000 years ago humans adapted genetically to be able to produce larger amounts of Omega-3 and Omega-6 fatty acids. This adaptation may have been crucial to the development of the unique brain capacity in modern humans.
  • higher risk of developing disorders like cardiovascular disease.
  • investigated the genes for the two key enzymes that are needed to produce Omega-3 and Omega-6 fatty acids from vegetable oils.
  • ...7 more annotations...
  • genetic adaptation for high production of Omega-3 and Omega-6 fatty acids is found only in humans
  • 300 000 years ago in the evolutionary line that led to modern humans
  • important factor for human survival in environments with limited dietary access to fatty acids
  • In today’s life situation, with a surplus of nourishment, this genetic adaptation contributes instead to a greater risk of developing disorders like cardiovascular disease
  • first study to show a genetic adaptation of human fat metabolism
  • thrifty gene
  • adaptation that contributed to enhanced survival in an earlier stage of human development, but in a life situation with an excess of food instead constitutes a risk factor for lifestyle diseases
  • Pop karnchanapimonkul on 13 Apr 12
     
    This article explains how earlier genetic adaptations that help our survival is now harming us.
chanon chiarnpattanodom

Genes an important factor in urinary incontinence - 1 views

www.sciencedaily.com/...110404142807.htm

Urinary Incontinence Genes

shared by chanon chiarnpattanodom on 11 Apr 12 - No Cached
  • chanon chiarnpattanodom on 11 Apr 12
     
    Scientists have studied how much is urinary incontinence controlled by genetics, rather than the environment by observing twins. 
Kaoko Miyazaki

lincRNA: A recently discovered RNA organizes stem cell differentiation - 0 views

scitechstory.com/...izes-stem-cell-differentiation

RNA lincRNA

shared by Kaoko Miyazaki on 11 Apr 12 - No Cached
  • Kaoko Miyazaki on 11 Apr 12
     
    Organizing how proteins assemble in embryonic cells and taking control over/deciding whether a stem cells stays pluripotent or not are only two of the main functions of the recently discovered lincRNAs. These new discoveries of lincRNAs and ongoing experiments only help researches such as Mitchell Guttman from the Broad Institute widen up the study of genetics and the human genome to a new field.
Mickey Tsai

Study finds gene variants behind childhood obesity risk - USATODAY.com - 0 views

www.usatoday.com/...1

gene childhood obesity

shared by Mickey Tsai on 13 Apr 12 - No Cached
  • Scientists have discovered two gene variants that appear to play a critical role in the development of common childhood obesity
  • Obesity is the result of a complex interplay among biological, behavioral, cultural, environmental and economic factors
  • a highly heritable condition,
  • ...2 more annotations...
  • a third of kids are obese or overweigh
  • gene research may provide insight into the biological pathways that contribute to obesity
  • Mickey Tsai on 13 Apr 12
     
    Scientists have found two gene variants that are likely to cause childhood obesity. This could be useful in knowing how to treat and prevent it. Although there is a genetic component to obesity, it is not the only factor. Biological, behavioral, cultural, environmental and economic factors can all play a role in obesity.
Nitchakan Chaiprukmalakan

Hoogsteen base pairs: An alternate structure in DNA - 0 views

scitechstory.com/...-an-alternate-structure-in-dna

shared by Nitchakan Chaiprukmalakan on 13 Apr 12 - No Cached
  • This discovery, made by a team of researchers from the University of Michigan (USA) and the University of California, Irvine (USA) and published in the journal Nature January 26, 2011 [Transient Hoogsteen base pairs in canonical duplex DNA] involves a new capability of nuclear magnetic resonance (NMR) machines and something most people have never heard of (including me): Hoogsteen base pairs.
  • It was discovered by the biologist Karst Hoogsteen in 1963. In effect, the Hoogsteen base pair is a ‘normal’ Watson-Crick base pair (usually A-T) flipped-over like an upside-down step on a ladder.
  • It changes the geometry and allows for truly exotic formations such as a triple helix or even quadruplex structures.
  • ...4 more annotations...
  • Hoogsteen base pairs were known to exist primarily in RNA and had been observed in DNA only when there was damage to the DNA structure, or something else like a protein or drug was bound to it.
  • In RNA the Hoogsteen base pairs have been studied fairly extensively. They are considered an “excited state” and are useful to observe unusual protein binding. In DNA the Hoogsteen base pairing, which by the way has two forms, normal and reverse, was considered an anomaly.
  • It was discovered that normal DNA undergoes these shifts about 1% of the time and they last only milliseconds.
  • “Together, these data suggest that there are multiple layers of information stored in the genetic code.” Because critical interactions between DNA and proteins are thought to be directed by both the sequence of bases and the flexing of the DNA molecule, these excited states represent a whole new level of information contained in the genetic code.
Pop karnchanapimonkul

Dieting During Pregnancy Increases Risk Of Obesity And Diabetes For Offspring - 0 views

www.medicalnewstoday.com/...243627.php

dieting obesity diabetes epigenics offspring

shared by Pop karnchanapimonkul on 14 Apr 12 - No Cached
  • babies of mothers who diet around the time of conception and in early pregnancy, may have an increased risk of obesity and type 2 diabetes throughout their lives. This study provides exciting insights into how behavior can lead to epigenetic changes in offspring related to obesity and disease.
  • dieting around the time a baby is conceived may increase the chance of the child becoming obese later in life
  • changes in the genes that control food intake and glucose levels that may lead to obesity and diabetes.
  • ...1 more annotation...
  • epigenetic changes with alterations in the structure of the DNA and its associated proteins, histones, which affects the way that genes can behave in later life.
  • Pop karnchanapimonkul on 14 Apr 12
     
    Article about how dieting during pregnancy cause offsprings to have a change in genes.
nidthamsirisup

Engineered stem cells seek out and kill HIV in living mice - 0 views

www.sciencedaily.com/...120412182253.htm

disease HIV

shared by nidthamsirisup on 15 Apr 12 - No Cached
  • human stem cells can be genetically engineered into HIV-fighting cells
  • surrogate model
  • CD8 cytotoxic T lymphocytes -- the "killer" T cells that help fight infection -- from an HIV-infected individual and identified the molecule known as the T cell receptor, which guides the T cell in recognizing and killing HIV-infected cells.
  • ...12 more annotations...
  • cloned the receptor and used this to genetically engineer human blood stem cells.
  • mature T cells that can attack HIV in tissues where the virus resides and replicates.
  • CD4 cells are white blood cells that are an important component of the immune system, helping to fight off infections.
  • CD4 "helper" T cells
  • HIV in the blood decreased.
  • increased
  • engineering stem cells to form immune cells that target HIV is effective in suppressing the virus in living tissues in an animal model
    • wasin kusakabe
      wasin kusakabe on 15 Apr 12
       
      Using mice as lab rats, researchers are able to produce a large amount of T cells that can fight off HIV more effectively.
  • Expanding on previous research providing proof-of-principle that human stem cells can be genetically engineered into HIV-fighting cells
  • The engineered stem cells developed into a large population of mature, multi-functional HIV-specific CD8 cells that could specifically target cells containing HIV proteins. The researchers also discovered that HIV-specific T cell receptors have to be matched to an individual in much the same way an organ is matched to a transplant patient.
  • In this current study, the researchers similarly engineered human blood stem cells and found that they can form mature T cells that can attack HIV in tissues where the virus resides and replicates. They did so by using a surrogate model, the humanized mouse, in which HIV infection closely resembles the disease and its progression in humans.
  • increased, while levels of HIV in the blood decreased. CD4 cells are white blood cells that are an important component of the immune system, helping to fight off infections. These results indicated that the engineered cells were capable of developing and migrating to the organs to fight infection there.
  • wasin kusakabe on 15 Apr 12
     
    Stem cells that are engineered to produce T cells that can help fight off HIV.
Mickey Tsai

Parkinson's disease sufferer Sheila Roy can write for the first time in 15 years thanks... - 0 views

www.dailymail.co.uk/...s-thanks-new-gene-therapy.html

gene therapy disease

shared by Mickey Tsai on 15 Apr 12 - No Cached
  • one of only 15 people worldwide to undergo the radical treatment, which involves inserting corrective genes into the brain
  • The genes provide the coded instructions for proteins needed to make dopamine, a brain chemical essential for proper control of movement.
  • Lack of dopamine leads to the symptoms of tremor, stiffness and poor balance associated with Parkinson’s.
  • ...3 more annotations...
  • Mrs Roy is taking part in an early-stage study of the ProSavin therapy
  • Following her treatment Sheila Roy has been able to carry out tasks like writing, something she has been unable to do for 15 years
  • Gene therapies hold great promise for people with Parkinson’s in the future, as they could mean an end to the daily regime of drugs that most people with the condition currently face.
  • Mickey Tsai on 15 Apr 12
     
    A woman with Parkinson's was able to write for the first time in 15 years because of gene therapy. Parkinson's includes symptoms such as tremors, loss of balance which makes it impossible to do even simple tasks. Doctors injected a modified virus carrying the genes to the motor centre of her brain which provide coded instructions for proteins needed to make dopamine. Lack of dopamine leads of the symptoms associated with Parkinson's. This is part of the ProSavin therapy developed by Oxford BioMedica. Gene therapies hold a lot of hope for people with Parkinson's that could end the daily routine of drugs that most of them go through.
Nickyz P.

GEN | Magazine Articles: Firm Focuses Operations on Gene Silencing - 0 views

www.genengnews.com/...4004

shared by Nickyz P. on 16 Apr 12 - No Cached
  • It is developing therapeutics to prove the validity of ddRNAi in treating cancer, infectious diseases, and disorders of the central nervous system.
  • The ddRNAi platform focuses on the long-term downregulation of genes, making it suitable for targeting chronic life-threatening diseases. “We are silencing genes instead of introducing new genes, which separates us from traditional gene therapy companies,” Dr. French asserts.
  • “This targeted treatment markedly enhanced the benefits of radiation therapy in both cellular and tumor models,” the researchers concluded. Other radiotherapy-resistant tumors may benefit from the shRNAs created for the prostate cancer study.
Nickyz P.

It's Alive! Artificial Life Springs From Manmade DNA : Discovery News - 0 views

news.discovery.com/...synthetic-genome-life.html

shared by Nickyz P. on 16 Apr 12 - No Cached
  • "This is the first synthetic cell that's been made," said Venter. "We call it synthetic because the cell is totally derived from a synthetic chromosome, made with four bottles of chemicals on a chemical synthesizer, starting with information in a computer."
  • Venter and his colleagues created a special code, similar to Morse code, to "write" within the DNA itself. Instead of dots and dashes, they used the sequence of four DNA nucleotides, thymine (T), guanine (G), cytosine (C), and adenine (A), as a code for any letter, number or punctuation mark. Using the code, the team included the names of the study co-authors, a website, and even several philosophical quotes, complete with punctuation.
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