Dados Bibliográficos

Resumo

ObjectivesThe vitamin D receptor (VDR) is a member of the nuclear receptor family of transcription factors. We examined whether degree of VDR gene methylation acts as a molecular adaptation to light exposure. We explored this in the context of photoperiod at conception, recent UV irradiance at 305 nm, and gene‐latitude effects.METHODSEighty subjects were examined for VDR gene‐CpG island methylation density. VDR gene variants were also examined by PCR‐RFLP.RESULTSPhotoperiod at conception was significantly positively related toVDRmethylation density, explaining 17% of the variance in methylation (r2 = 0.17;P = .001). Within this model, photoperiod at conception and plasma 25(OH)D independently predicted methylation density at theVDR‐CpG island. Recent UV exposure at 305 nm led to a fivefold increase in mean methylation density (P = .02). Again, UV exposure and plasma 25(OH)D independently predicted methylation density at theVDR‐CpG island. In the presence of the BsmI mutant allele, methylation density was increased (P = .01), and in the presence of the TaqI or FokI mutant allele, methylation density was decreased (P = .007 and .04 respectively). Multivariate modelling suggests plasma 25(OH)D, photoperiod at conception, recent solar irradiance, andVDRgenotype combine as independent predictors of methylation at theVDR‐CpG island, explaining 34% of the variance in methylation (R2 = 0.34,P < .0001).CONCLUSIONSDuration of early‐life light exposure and strength of recent irradiance, along with latitudinal genetic factors, influence degree of VDR gene methylation consistent with this epigenetic phenomenon being a molecular adaptation to variation in ambient light exposure. Findings contribute to our understanding of human biology.

Referências Citadas