Aging and biomarkers: Transcriptional levels evaluation of Osteopontin/miRNA-181a axis in hepatic tissue of rats in different age ranges.

Osteopontin (OPN), a novel hepatic damage marker, as well as several non-coding RNA seem to be associated with liver aging, a little studied and not yet defined process. The aim of the study was to evaluate the expression variations of OPN and miRNA-181a, the transcriptional profiling of long non coding (lnc) RNA GAS-5/miRNA-222 axis and lncRNA NEAT-1 in liver tissue of rats. In addition, to monitor the senescence process, the telomere shortening and TERT/TERC gene expression were also measured. Three groups of male Wistar rats were studied: A (n = 6, young); B (n = 13, adult); C (n = 10, old). Total RNA, including miRNAs, was extracted from liver and analysed by Real-Time PCR. Ultrasound and biochemical evaluation were performed in all rats as well as the histological analysis. OPN mRNA resulted lower in C with respect to A and B while miRNA-181a expression was significantly increased as a function of age. An increasing of both NEAT-1 and miRNA-222 expression as a function of age in parallel with a decreasing of GAS-5 expression in young and old rats, but not in the adults, was observed. A positive correlation was detected between miRNA-181a and miRNA-222. The hepatic ultrasound analysis revealed areas of hyperechogenicity distributed as a function of age. A significant telomere shortening was measured as a function of age while the two subunits TERT and TERC expressions showed an opposite trend. This work could provide a valid starting point to better understand the physiopathological changes during aging, pinpointing in the OPN/miRNA-181a axis significant predictors of successful aging.

Evaluation of transcriptional levels of the natriuretic peptides, endothelin-1, adrenomedullin, their receptors and long non-coding RNAs in rat cardiac tissue as cardiovascular biomarkers of aging.

Chronological age is considered one of the major risk factors for cardiovascular disease and mortality. The study aimed to evaluate the transcriptional levels of the natriuretic peptides (NP), endothelin (ET)-1, adrenomedullin (ADM), their receptors and long non-coding (Lnc) RNA MIAT, MALAT-1, CARMEN and XIST in rat cardiac tissue as cardiovascular biomarkers of aging. Three groups of male Wistar rats were studied: A (n = 6; young), B (n = 13; adult), C (n = 10; old). Total RNA was extracted from left ventricle and analyzed by Real-Time PCR. Echocardiographic and histological analyses were performed. A significant increase of Atrial NP (ANP) and Brain NP (BNP) mRNA was observed in C while C-type NP (CNP) remained in a steady-state in B and C; ET-1 mRNA increased significantly as a function of age. Any difference was observed for NP receptors. ETA expression was statistically lower in B than A while ETB were similar in all the three groups. The ADM showed an opposite trend to that of the other peptides decreasing significantly as a function of age and presenting a counter-regulation of calcitonin receptor-like receptor (CLR) and receptor activity modifying protein (RAMP)-2. LncRNA transcripts decreased significantly as a function of age except for XIST. ADM and LncRNA trend suggest that the animals are subjected to "successful aging" as also confirmed by histological analysis. Applying a multivariate logistic regression analysis, only LnANP (p = 0.003) and LnADM (p = 0.023) resulted significantly associated with aging identifying them, for the first time, as independent markers of aging. The study underlining the importance of a multi-label biomolecular approach in the evaluation of aging.