Impairment of spermatogenesis and sperm motility by the high-fat diet-induced dysbiosis of gut microbes. Ding Ning,Zhang Xin,Zhang Xue Di,Jing Jun,Liu Shan Shan,Mu Yun Ping,Peng Li Li,Yan Yun Jing,Xiao Geng Miao,Bi Xin Yun,Chen Hao,Li Fang Hong,Yao Bing,Zhao Allan Z Gut OBJECTIVE:High-fat diet (HFD)-induced metabolic disorders can lead to impaired sperm production. We aim to investigate if HFD-induced gut microbiota dysbiosis can functionally influence spermatogenesis and sperm motility. DESIGN:Faecal microbes derived from the HFD-fed or normal diet (ND)-fed male mice were transplanted to the mice maintained on ND. The gut microbes, sperm count and motility were analysed. Human faecal/semen/blood samples were collected to assess microbiota, sperm quality and endotoxin. RESULTS:Transplantation of the HFD gut microbes into the ND-maintained (HFD-FMT) mice resulted in a significant decrease in spermatogenesis and sperm motility, whereas similar transplantation with the microbes from the ND-fed mice failed to do so. Analysis of the microbiota showed a profound increase in genus and , both of which likely contributed to the metabolic endotoxaemia in the HFD-FMT mice. Interestingly, the gut microbes from clinical subjects revealed a strong negative correlation between the abundance of and sperm motility, and a positive correlation between blood endotoxin and abundance. Transplantation with HFD microbes also led to intestinal infiltration of T cells and macrophages as well as a significant increase of pro-inflammatory cytokines in the epididymis, suggesting that epididymal inflammation have likely contributed to the impairment of sperm motility. RNA-sequencing revealed significant reduction in the expression of those genes involved in gamete meiosis and testicular mitochondrial functions in the HFD-FMT mice. CONCLUSION:We revealed an intimate linkage between HFD-induced microbiota dysbiosis and defect in spermatogenesis with elevated endotoxin, dysregulation of testicular gene expression and localised epididymal inflammation as the potential causes. TRIAL REGISTRATION NUMBER:NCT03634644. 10.1136/gutjnl-2019-319127

Precise Correction of Lhcgr Mutation in Stem Leydig Cells by Prime Editing Rescues Hereditary Primary Hypogonadism in Mice. Advanced science (Weinheim, Baden-Wurttemberg, Germany) Hereditary primary hypogonadism (HPH), caused by gene mutation related to testosterone synthesis in Leydig cells, usually impairs male sexual development and spermatogenesis. Genetically corrected stem Leydig cells (SLCs) transplantation may provide a new approach for treating HPH. Here, a novel nonsense-point-mutation mouse model (Lhcgr ) is first generated based on a gene mutation relative to HPH patients. To verify the efficacy and feasibility of SLCs transplantation in treating HPH, wild-type SLCs are transplanted into Lhcgr mice, in which SLCs obviously rescue HPH phenotypes. Through comparing several editing strategies, optimized PE2 protein (PEmax) system is identified as an efficient and precise approach to correct the pathogenic point mutation in Lhcgr. Furthermore, delivering intein-split PEmax system via lentivirus successfully corrects the mutation in SLCs from Lhcgr mice ex vivo. Gene-corrected SLCs from Lhcgr mice exert ability to differentiate into functional Leydig cells in vitro. Notably, the transplantation of gene-corrected SLCs effectively regenerates Leydig cells, recovers testosterone production, restarts sexual development, rescues spermatogenesis, and produces fertile offspring in Lhcgr mice. Altogether, these results suggest that PE-based gene editing in SLCs ex vivo is a promising strategy for HPH therapy and is potentially leveraged to address more hereditary diseases in reproductive system. 10.1002/advs.202300993

Nestin-dependent mitochondria-ER contacts define stem Leydig cell differentiation to attenuate male reproductive ageing. Nature communications Male reproductive system ageing is closely associated with deficiency in testosterone production due to loss of functional Leydig cells, which are differentiated from stem Leydig cells (SLCs). However, the relationship between SLC differentiation and ageing remains unknown. In addition, active lipid metabolism during SLC differentiation in the reproductive system requires transportation and processing of substrates among multiple organelles, e.g., mitochondria and endoplasmic reticulum (ER), highlighting the importance of interorganelle contact. Here, we show that SLC differentiation potential declines with disordered intracellular homeostasis during SLC senescence. Mechanistically, loss of the intermediate filament Nestin results in lower differentiation capacity by separating mitochondria-ER contacts (MERCs) during SLC senescence. Furthermore, pharmacological intervention by melatonin restores Nestin-dependent MERCs, reverses SLC differentiation capacity and alleviates male reproductive system ageing. These findings not only explain SLC senescence from a cytoskeleton-dependent MERCs regulation mechanism, but also suggest a promising therapy targeting SLC differentiation for age-related reproductive system diseases. 10.1038/s41467-022-31755-w

DNMT3A-dependent DNA methylation is required for spermatogonial stem cells to commit to spermatogenesis. Nature genetics DNA methylation plays a critical role in spermatogenesis, as evidenced by the male sterility of DNA methyltransferase (DNMT) mutant mice. Here, we report a division of labor in the establishment of the methylation landscape of male germ cells and its functions in spermatogenesis. Although DNMT3C is essential for preventing retrotransposons from interfering with meiosis, DNMT3A broadly methylates the genome (with the exception of DNMT3C-dependent retrotransposons) and controls spermatogonial stem cell (SSC) plasticity. By reconstructing developmental trajectories through single-cell RNA sequencing and profiling chromatin states, we found that Dnmt3A mutant SSCs can only self-renew and no longer differentiate in association with spurious enhancer activation that enforces an irreversible stem cell gene program. Our findings therefore highlight a key function of DNA methylation in male fertility: the epigenetic programming of SSC commitment to differentiation and lifelong spermatogenesis supply. 10.1038/s41588-022-01040-z