Serum 25(OH) vitamin D and SIRT1- VDR- miR-124 expression: A controlled interventional study in a vitamin D-deficient...

Epigenetic aging is a new dimensional advancement in geroscience that continually addresses factors beyond genetic determinants of longevity. It occurs through three conventional pathways, one of which is non-coding RNA production. miR-124 is a newly introduced miRNA that was found in aged skin and several tumorigenic cells and is associated with aging. Additionally, SIRT1, a protein from the NAD⁺-dependent family, is found to have a protective mechanism in the pathways of aging. On the other hand, vitamin D works as an epigenetic factor and often targets pathways related to the aging process. In this study, the aim is to identify the expression of miR-124 in circulating blood to address the epigenetic-related biomarker and link the facets with anti-aging SIRT1 and vitamin D cognate receptor (VDR) to understand vitamin D deficiency interception.

A vitamin D deficiency middle-aged rat model was developed by assigning male Albino Wistar Rats. Paricalcitol was administered IP (intraperitoneal) to the experimental group (32 ng/day) to induce deficiency, along with a calcium-rich rescue diet. The study was conducted for 21 days following blood collection and storage. ELISA and RTqPCR were performed to estimate serum 25(OH)D and gene expression analysis, respectively.

25(OH)D comparison between the group p-value of 0.002. The log2 fold changes of SIRT1, VDR, and miR-124 were compared between the groups using boxplot visualisation. A linear regression model was developed to understand the explorative nature of aging index (R² = 0.561; Adjusted R² = 0.517; p = 0.005; n = 12).

A putative epigenetic relation was found between miR-124 levels and their association with SIRT1. The investigated biomarkers of aging are associated with serum concentration of 25(OH) vitamin D in a middle-aged vitamin D-deficient rat model, which supports the need for mechanistic investigation in future studies.