Leydig cells (LCs) represent a somatic testicular population responsible for testosterone synthesis, a hormone essential for spermatogenesis and male fertility. The obesity condition impairs LC steroidogenic activity, contributing to testicular oxidative stress and male reproductive dysfunctions. Using a high-fat-diet (HFD) murine model, we investigated the regulatory role of the nuclear factor of activated T cells 5 (NFAT5s) in the obesity-induced LC damage and the resulting alterations in intergenerationally inherited sperm circRNA cargo. Our findings reveal a significant upregulation of both circNFAT5 and NFAT5 protein levels in HFD testis. This molecular signature correlated with decreased antioxidant defense system, increased LC apoptosis, and impaired steroidogenesis. In vitro experiments, performed in TM3 cells, confirmed that NFAT5 nuclear shuttling drives proapoptotic gene activation, while NFAT5 silencing promotes LC survival. The analysis of HFD progeny (F1H) revealed a full recovery of testis oxidative status and LC apoptosis, linked with the recovery of NFAT5 expression. However, a steroidogenic deficiency persisted in F1H offspring. Notably, HFD and F1H epididymides exhibited NFAT5 overexpression concomitantly with impaired sperm morphology, motility, viability, and altered sperm circRNA profiles alongside a deregulated 4-hydroxy-2-nonenal (4HNE) profile, a marker of sperm oxidative stress. Lastly, an enhanced FUS-related amplification of circRNA perturbations was highlighted in F1H spermatozoa. Collectively, our findings reveal a dual functional role of NFAT5 as a testicular regulator of LC fate and an epididymal sentinel of metabolic stress, in turn linking paternal obesity to the persistent transmission of sperm epigenetic anomalies across the offspring.

Hepatocellular carcinoma (HCC) is among the most aggressive and lethal human tumors. Many functional studies have demonstrated the role of non-coding RNAs (ncRNA), particularly microRNAs (miRNA), in the regulation of hepatocarcinogenesis driving pathways. MiR-125a-5p (miR-125a) has been consistently reported as an oncosuppressive miRNA, as demonstrated in vivo and in vitro. However, its HCC relevant targets and molecular mechanisms are still largely unknown. Here, a genome-wide perspective of the whole miR-125a targetome has been achieved. In particular, two different HCC cell lines were subjected to a miRNA boosting by mimic transfections, and consequently many genes were de-regulated, as observed by a transcriptomic approach. The merging of down-regulated genes with results from bioinformatic predictive tools yielded a number of candidate direct targets that were further experimentally validated by luciferase-based reporter assays. Different novel targets were found, in particular ARID3A, CCNJ, LIPA, NR6A1, and NUP210, oncogenes in various tumors and here also related to HCC through miR-125a regulation. The RNA interactions investigated in this work could pave the way to piece together the RNA regulatory networks governed by the miRNA impacting on hepatocarcinogenesis, and be exploited in the future for identifying novel biomarkers and therapeutic targets in HCC.