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- Creators: Jurutka, Peter
Description
Psoriasis is a skin disease that affects millions of individuals. Genetic risk factors for psoriasis include a common deletion of two late cornified envelope (LCE) genes (LCE3B and LCE3C) located within a cluster of genes expressed during epithelial differentiation and skin repair. It was previously discovered that treatment with 1,25-dihydroxyvitamin D3 (1,25D) or analogs thereof can improve psoriasis symptoms in many patients, but the molecular mechanisms for this action are largely unknown. Our laboratory previously showed that 1,25D as well as low affinity ligands for the vitamin D receptor (VDR), such as delphinidin and cyanidin, are capable of upregulating the remaining LCE3A, -3D, and -3E genes to potentially compensate for the loss of LCE3B and -3C in promoting skin repair. In the current study, DHA and curcumin were tested and found to also upregulate LCE3 transcripts in a dose-dependent manner. To investigate other potential target genes for 1,25D and DHA, we tested JunB, for which low or absent expression has been reported to cause or be associated with psoriatic lesions. Our experiments showed a trend for an upregulation of JunB mRNA after DHA treatment, potentially providing benefit for psoriasis patients. Although our hypothesis is that DHA functions as a vitamin D receptor ligand to mediate upregulation of JunB and LCE3 genes, other investigators have assumed that DHA actions in skin are mediated via PPAR isoforms. We therefore utilized a selective ligand for PPAR delta (GW501516) to determine whether PPAR delta, the primary PPAR isoform in keratinocytes, is a mediator of DHA-induced LCE3 gene activation. Although a modest upregulation of LCE3 genes was seen after treatment with GW501516, our findings are still consistent with DHA acting primarily as a VDR ligand. Our results not only provide additional information about the ability of VDR ligands to upregulate specific skin genes with relevance for skin repair, but also may help provide a molecular basis for testing improved treatments for mild to moderate psoriasis.
ContributorsKarrys, Amitis (Author) / Jurutka, Peter (Thesis director) / Whitfield, Kerr (Committee member) / School of Life Sciences (Contributor) / Barrett, The Honors College (Contributor)
Created2016-05
Description
Vitamin D3 (cholecalciferol) is an essential micronutrient that plays a key role in developmental growth and lifespan in mammals. However, few studies have shown how vitamin D3 plays its vital functions in arthropods. Here, we examined the effects of full (13.3 IU/mL) and half dose (6.65 IU/mL) vitamin D3 on the growth and lifespan of Drosophila melanogaster. Vitamin B12 is another micronutrient that shows decreases absorption in elderly patients and might be linked to symptoms associated with aging rather than lifespan, but again, the effects of vitamin B12 supplementation in arthropods is poorly characterized. Results showed that both full and half doses of vitamin D3 and B12 do not significantly alter the timing of pupariation or adult eclosion. Similarly, the mortality rate of adult D. melanogaster exposed to vitamin B12 or higher doses of vitamin D3 was not significantly decreased or increased. However, a low dose of vitamin D3 did significantly lower the mortality rate of D. melanogaster. The genetic composition of Drosophila for vitamin B12 and D metabolism showed similarities in humans. However, there are no biological evidences if these genes are functional thus, this may explain the results of this study.
ContributorsRebonza, Edzel May Suico (Author) / Hackney Price, Jennifer (Thesis director) / Jurutka, Peter (Committee member) / School of Mathematical and Natural Sciences (Contributor) / Barrett, The Honors College (Contributor)
Created2020-05