N-Acetylcysteine assists muscle development in offspring of mice subjected to maternal heat stress during pregnancy.

BACKGROUND: Heat stress (HS) has been shown to affect reproductive performance and muscle development negatively in animals. N-Acetylcysteine (NAC) plays a pivotal role in enhancing the antioxidant performance in animals as a recognized antioxidant. The present study assesses the potential of NAC to modulate the reproductive performance and antioxidant function in pregnant mice exposed to HS. The role of NAC in muscle development of offspring mice was also explored. RESULTS: The results showed that NAC supplementation from day 12 to day 18 of gestation increased the number of litters and enhanced the antioxidant function in pregnant mice under HS exposure. It improved the weight and body condition significantly in the offspring mice (P < 0.05). The alleviation of HS-induced muscle impairment with NAC was consistent with the alleviation of apoptosis, the enrichment of the proliferation and differentiation in the offspring mice muscle. N-Acetylcysteine also reversed HS-induced reduction in the cross-sectional area of the leg muscle and increased the proportion of myosin heavy chain IIx (MYHCIIx) in the muscle fiber. CONCLUSION: The results of the present study support the use of NAC at a dose of 100 mg kg-1 body weight as supplement for protecting the offspring derived from pregnant mice exposed to HS from muscle impairment by accelerating proliferation and differentiation. © 2024 Society of Chemical Industry.

Bta-miR-6531 Regulates Calcium Influx in Bovine Leydig Cells and Is Associated with Sperm Motility.

MicroRNAs (miRNAs) play key roles in sperm as the regulatory factors involved in fertility and subsequent early embryonic development. Bta-miR-6531 is specifically a highly enriched miRNA in low-motility sperms in previous study. To investigate the mechanism of bta-miR-6531, 508 shared target genes of bta-miR-6531 were predicted using two miRNA target databases (TargetScan7 and miRWalk). According to the Kyoto Encyclopedia of Genes and Genomes (KEGG), the calcium and cAMP signaling pathways were the most enriched of the target genes. A dual-luciferase assay indicated that bta-miR-6531 targeted ATP2A2 mRNA by binding to the coding sequence region. In bovine Leydig cells, bta-miR-6531 overexpression affected the intracellular calcium concentration by restraining ATP2A2 expression. Moreover, we observed high calcium concentrations and high ATP2A2 protein levels in high-motility sperm compared with those in low-motility sperms. Furthermore, high-linkage single-nucleotide polymorphisms (SNPs) of the pre-bta-miR-6531 sequence were identified that related to sperm traits. Genotype TCTC of bta-miR-6531 showed high sperm motility and density and low deformity rate in Holstein bulls. However, the mutation in pre-miR-6531 did not significantly affect mature bta-miR-6531 expression in the sperm or cell models. Our results demonstrate that bta-miR-6531 might involve in sperm motility regulation by targeting ATP2A2 of the calcium signaling pathway in bovine spermatozoa.