No abstract

Continuous exposure to ultraviolet B (UVB) can cause photodamage of the skin. This photodamage can be inhibited by the overexpression of the non-coding RNA, nc886, via the protein kinase RNA-activated (PKR) pathway. The study aims to identify how UVB inhibits nc886 expression, and it also seeks to determine whether substances that can control nc886 expression can influence UV-induced inflammation, and the mechanisms involved. The results suggest that UVB irradiation accelerates the methylation of the nc886 gene, therefore, reducing its expression. This induces the activation of the PKR, which accelerates the expression of metalloproteinase-9 (MMP-9) and cyclooxygenase (COX-2), and the production of MMP-9, prostaglandin-endoperoxide synthase (PGE2), and certain pro-inflammatory cytokines, specifically interleukin-8 (IL-8), and tumor necrosis factor-α (TNF-α). Conversely, in a model of nc886 overexpression, the expression and production of those inflammatory factors are inhibited. In addition, Laminaria japonica extract (LJE) protect the levels of nc886 against UVB irradiation then subsequently inhibit the production of UV-induced inflammatory factors through the PKR pathway.

Functional studies of organisms and human models have revealed that epigenetic changes can significantly impact the process of aging. Non-coding RNA (ncRNA), one of epigenetic regulators, plays an important role in modifying the expression of mRNAs and their proteins. It can mediate the phenotype of cells. It has been reported that nc886 (=vtRNA2-1 or pre-miR-886), a long ncRNA, can suppress tumor formation and photo-damages of keratinocytes caused by UVB. The aim of this study was to determine the role of nc886 in replicative senescence of fibroblasts and determine whether substances capable of controlling nc886 expression could regulate cellular senescence. In replicative senescence fibroblasts, nc886 expression was decreased while methylated nc886 was increased. There were changes of senescence biomarkers including SA-β-gal activity and expression of p16INK4A and p21Waf1/Cip1 in senescent cells. These findings indicate that the decrease of nc886 associated with aging is related to cellular senescence of fibroblasts and that increasing nc886 expression has potential to suppress cellular senescence. AbsoluTea Concentrate 2.0 (ATC) increased nc886 expression and ameliorated cellular senescence of fibroblasts by inhibiting age-related biomarkers. These results indicate that nc886 has potential as a new target for anti-aging and that ATC can be a potent epigenetic anti-aging ingredient.