Group items tagged

Vitamin D content in Alaskan Arctic zooplankton, fishes, and marine mammals. David E. Kenny 1, Todd M. O'Hara, Tai C. Chen, Zhiren Lu, Xiao Tian, Michael F. Holick. Zoo Biology Volume 23 Issue 1, Pages 33 - 43 Published Online: 13 Feb 2004 Doi: 10.1002/zoo.10104

Conclusion We demonstrated that the VDRE in the CAMP gene originated from the exaptation of an AluSx SINE in the lineage leading to humans, apes, OWMs and NWMs and remained under purifying selection for the last 55-60 million years. We present convincing evidence of an evolutionarily fixed, Alu-mediated divergence in steroid hormone nuclear receptor gene regulation between humans/primates and other mammals. Evolutionary selection to place the primate CAMP gene under regulation of the vitamin D pathway potentiates the innate immune response and may counter the anti-inflammatory properties of vitamin D. Exaptation of an ancient Alu short interspersed element provides a highly conserved vitamin D-mediated innate immune response in humans and primates. Gombart AF, Saito T, Koeffler HP. BMC Genomics. 2009 Jul 16;10:321. PMID: 19607716 doi:10.1186/1471-2164-10-321

The vitamin D-antimicrobial peptide pathway and its role in protection against infection. Gombart AF. Future Microbiol. 2009 Nov;4:1151-65. PMID: 19895218 Vitamin D deficiency has been correlated with increased rates of infection. Since the early 19th century, both environmental (i.e., sunlight) and dietary sources (cod liver) of vitamin D have been identified as treatments for TB. The recent discovery that vitamin D induces antimicrobial peptide gene expression explains, in part, the 'antibiotic' effect of vitamin D and has greatly renewed interest in the ability of vitamin D to improve immune function. Subsequent work indicates that this regulation is biologically important for the response of the innate immune system to wounds and infection and that deficiency may lead to suboptimal responses toward bacterial and viral infections. The regulation of the cathelicidin antimicrobial peptide gene is a human/primate-specific adaptation and is not conserved in other mammals. The capacity of the vitamin D receptor to act as a high-affinity receptor for vitamin D and a low-affinity receptor for secondary bile acids and potentially other novel nutritional compounds suggests that the evolutionary selection to place the cathelicidin gene under control of the vitamin D receptor allows for its regulation under both endocrine and xenobiotic response systems. Future studies in both humans and humanized mouse models will elucidate the importance of this regulation and lead to the development of potential therapeutic applications

"Cathelicidin antimicrobial peptide is a family of polypeptides found in lysosomes in polymorphonuclear leukocytes (PMNs).[1] Members of the cathelicidin family of antimicrobial polypeptides are characterized by a highly conserved region (cathelin domain) and a highly variable cathelicidin peptide domain. Cathelicidin peptides have been isolated from many different species of mammals. Cathelicidins were originally found in neutrophils but have since been found in many other cells including epithelial cells and macrophages activated by bacteria, viruses, fungi, or the hormone 1,25-D"