Identification and functional characterization of microRNAs in rat Leydig cells during development from the progenitor to the adult stage

Elucidating the Role of OXPHOS Variants in Asthenozoospermia: Insights from Whole Genome Sequencing and an In Silico Analysis

Infertility is a global health challenge that affects an estimated 72.4 million people worldwide. Between 30 and 50% of these cases involve male factors, showcasing the complex nature of male infertility, which can be attributed to both environmental and genetic determinants. Asthenozoospermia, a condition characterized by reduced sperm motility, stands out as a significant contributor to male infertility. This study explores the involvement of the mitochondrial oxidative phosphorylation (OXPHOS) system, crucial for ATP production and sperm motility, in asthenozoospermia. Through whole-genome sequencing and in silico analysis, our aim was to identify and characterize OXPHOS gene variants specific to individuals with asthenozoospermia. Our analysis identified 680,099 unique variants, with 309 located within OXPHOS genes. Nine of these variants were prioritized due to their significant implications, such as potential associations with diseases, effects on gene expression, protein function, etc. Interestingly, none of these variants had been previously associated with male infertility, opening up new avenues for research. Thus, through our comprehensive approach, we provide valuable insights into the genetic factors that influence sperm motility, laying the foundation for future research in the field of male infertility.

Impacts and potential mechanisms of fine particulate matter (PM2.5) on male testosterone biosynthesis disruption

Exposure to PM2.5 is the most significant air pollutant for health risk. The testosterone level in male is vulnerable to environmental toxicants. In the past, researchers focused more attention on the impacts of PM2.5 on respiratory system, cardiovascular system, and nervous system, and few researchers focused attention on the reproductive system. Recent studies have reported that PM2.5 involved in male testosterone biosynthesis disruption, which is closely associated with male reproductive health. However, the underlying mechanisms by which PM2.5 causes testosterone biosynthesis disruption are still not clear. To better understand its potential mechanisms, we based on the existing scientific publications to critically and comprehensively reviewed the role and potential mechanisms of PM2.5 that are participated in testosterone biosynthesis in male. In this review, we summarized the potential mechanisms of PM2.5 triggering the change of testosterone level in male, which involve in oxidative stress, inflammatory response, ferroptosis, pyroptosis, autophagy and mitophagy, microRNAs (miRNAs), endoplasmic reticulum (ER) stress, and N6-methyladenosine (m6A) modification. It will provide new suggestions and ideas for prevention and treatment of testosterone biosynthesis disruption caused by PM2.5 for future research.

Role of miR-300-3p in Leydig cell function and differentiation: A therapeutic target for obesity-related testosterone deficiency

MicroRNAs (miRNAs) regulate various cellular functions, but their specific roles in the regulation of Leydig cells (LCs) have yet to be fully understood. Here, we found that the expression of miR-300-3p varied significantly during the differentiation from progenitor LCs (PLCs) to adult LCs (ALCs). High expression of miR-300-3p in PLCs inhibited testosterone production and promoted PLC proliferation by targeting the steroidogenic factor-1 (Sf-1) and transcription factor forkhead box O1 (FoxO1) genes, respectively. As PLCs differentiated into ALCs, the miR-300-3p expression level significantly decreased, which promoted testosterone biosynthesis and suppressed proliferation of ALCs by upregulating SF-1 and FoxO1 expression. The LH/METTL3/SMURF2/SMAD2 cascade pathway controlled miR-300-3p expression, in which luteinizing hormone (LH) upregulated SMAD-specific E3 ubiquitin protein ligase 2 (SMURF2) expression through methyltransferase like 3 (METTL3)-mediated Smurf2 N6-methyladenosine modification. The Smurf2 then suppressed miR-300 transcription by inhibiting SMAD family member 2 (SMAD2) binding to the promoter of miR-300. Notably, miR-300-3p was associated with an obesity-related testosterone deficiency in men and the inhibition of miR-300-3p effectively rescued testosterone deficiency in obese mice. These findings suggested that miR-300-3p plays a pivotal role in LC differentiation and function, and could be a promising diagnostic or therapeutic target for obesity-related testosterone deficiency.

High-fidelity reprogramming into Leydig-like cells by CRISPR activation and paracrine factors

Androgen deficiency is a common medical conditions that affects males of all ages. Transplantation of testosterone-producing cells is a promising treatment for male hypogonadism. However, getting a cell source with the characteristics of Leydig cells (LCs) is still a challenge. Here, a high-efficiency reprogramming of skin-derived fibroblasts into functional Leydig-like cells (LLCs) based on epigenetic mechanism was described. By performing an integrated analysis of genome-wide DNA methylation and transcriptome profiling in LCs and fibroblasts, the potentially epigenetic-regulating steroidogenic genes and signaling pathways were identified. Then by using CRISPR/dCas9 activation system and signaling pathway regulators, the male- or female-derived fibroblasts were reprogrammed into LLCs with main LC-specific traits. Transcriptomic analysis further indicated that the correlation coefficients of global genes and transcription factors between LLCs and LCs were higher than 0.81 and 0.96, respectively. After transplantation in the testes of hypogonadal rodent models, LLCs increased serum testosterone concentration significantly. In type 2 diabetic rats model, LLCs which were transplanted in armpit, have the capability to restore the serum testosterone level and improve the hyperglycemia status. In conclusion, our approach enables skin-derived fibroblasts reprogramming into LLCs with high fidelity, providing a potential cell source for the therapeutics of male hypogonadism and metabolic-related comorbidities.

Generation of Leydig-like cells: approaches, characterization, and challenges

Testosterone production by Leydig cells (LCs) plays a crucial role in male reproduction. The functional degeneration of LCs can cause testosterone deficiency, ultimately resulting in primary male hypogonadism. Transplantation of exogenous LCs with the ability to produce testosterone in response to the regulation of the hypothalamus-pituitary-gonad axis could be a promising alternative option to treat male primary hypogonadism. Recent studies have shown that it is possible to generate Leydig-like cells from stem cells by various approaches. In addition, somatic cells, such as embryonic or adult fibroblasts, have also been successfully reprogrammed into Leydig-like cells. In this review, we summarized the recent advances in the generation of Leydig-like cells, with an emphasis on comparing the effectiveness and safety of different protocols used and the cells generated. By further analyzing the characteristics of Leydig-like cells generated from fibroblasts based on small signaling molecules and regulatory factors, we found that although the cells may produce testosterone, they are significantly different from real LCs. For future in vivo applications, it is important that the steroidogenic cells generated be evaluated not only for their steroidogenic functions but also for their overall cell metabolic state by proteomics or transcriptomic tools.

Mechanism of microRNA regulating the progress of atherosclerosis in apoE-deficient mice

MicroRNAs play important roles in atherosclerogenesis and are important novel pharmaceutic targets in atherosclerosis management. The whole spectrum of miRNAs dysregulation is still under intense investigation. This study intends to identify more novel dysregulated microRNAs in atherosclerotic mice. Half of eight-week-old male ApoE-/- mice were fed with high-fat-diet for 12 weeks as a model mice, and the remaining half of ApoE-/- mice were fed with a normal-diet as a control. A serum lipid profile was performed with ELISA kits, and atherosclerotic lesions were assessed. Aortic tissues were dissected for gene expression profiling using a Multispecies miRNA 4.0 Array, and significant differentially expressed miRNAs were identified with fold change ≥ 2 and p < 0.05. Real-time quantitative PCR was used to validate microarray gene expression data on selected genes. Predicted target genes were extracted and subjected to bioinformatic analysis for molecular function and pathway enrichment analysis. Model mice showed a 15.32% atherosclerotic lesion compared to 1.52% in the control group. A total of 25 significant differentially expressed microRNAs were identified, with most of them (24/25) downregulated. Real-time quantitative PCR confirmed the GeneChip data. Bioinformatic analysis of predicted target genes identified high involvement of the PI3K/Akt/mTOR signaling pathway. Microarray profiling of miRNAs in high-fat-fed Model mice identified 25 differentially expressed miRNAs, including some novel miRNAs, and the PI3K/Akt/mTOR signaling pathway is highly enriched in the predicted target genes. The novel identified dysregulated miRNAs suggest a broader spectrum of miRNA dysregulation in the progression of atherosclerosis and provide more research and therapeutic targets for atherosclerosis.