LncRNA HOTAIR promotes proliferation and suppresses apoptosis of mouse spermatogonium GC-1 cells by sponging miR-761 to modulate NANOS2 expression

Epigenetics of nonobstructive azoospermia

ABSTRACT

Nonobstructive azoospermia (NOA) is a severe and heterogeneous form of male factor infertility caused by dysfunction of spermatogenesis. Although various factors are well defined in the disruption of spermatogenesis, not all aspects due to the heterogeneity of the disorder have been determined yet. In this review, we focus on the recent findings and summarize the current data on epigenetic mechanisms such as DNA methylation and different metabolites produced during methylation and demethylation and various types of small noncoding RNAs involved in the pathogenesis of different groups of NOA.

The microRNA-mediated apoptotic signaling axis in male reproduction: a possible and targetable culprit in male infertility

Recently, infertility has emerged as a significant and prevalent public health concern warranting considerable attention. Apoptosis, recognized as programmed cell death, constitutes a crucial process essential for the maintenance of normal spermatogenesis. Multiple investigations have illustrated that the dysregulated apoptosis of reproductive cells, encompassing spermatogonial stem cells, Sertoli cells, and Leydig cells, serves as a causative factor in male infertility. MicroRNAs represent a class of small RNA molecules that exert negative regulatory control over gene expression using direct interaction with messenger RNA transcripts. Previous studies have established that aberrant expression of miRNAs induces apoptosis in reproductive tissues, correlating with reproductive dysfunctions and infertility. In this review, we offer a comprehensive overview of miRNAs and their respective target genes implicated in the apoptotic process. As well, miRNAs are involved in multiple apoptotic signaling pathways, namely the PI3K/AKT, NOTCH, Wnt/β-catenin, and mTOR signaling cascades, exerting both negative and positive effects. We additionally elucidate the significant functions played by lncRNAs and circular RNAs as competing endogenous RNAs in the process of apoptosis within reproductive cells. We further illustrate that external factors, including silica nanoparticles, Cyclosporine A, and smoking, induce dysregulation of miRNAs, resulting in apoptosis within reproductive cells and subsequent male reproductive toxicity. Further, we discuss the implication of heat stress, hypoxia, and diabetes in reproductive cell apoptosis induced by miRNA dysregulation in male infertility. Finally, we demonstrate that the modulation of miRNAs via traditional and novel medicine could protect reproductive cells from apoptosis and be implemented as a therapeutic approach in male infertility.

Long noncoding RNAs in human reproductive processes and diseases

Infertility has become a global disease burden. Although assisted reproductive technologies are widely used, the assisted reproduction birth rate is no more than 30% worldwide. Therefore, understanding the mechanisms of reproduction can provide new strategies to improve live birth rates and clinical outcomes of enhanced implantation. Long noncoding RNAs (lncRNAs) have been reported to exert regulatory roles in various biological processes and diseases in many species. In this review, we especially focus on the role of lncRNAs in human reproduction. We summarize the function and mechanisms of lncRNAs in processes vital to reproduction, such as spermatogenesis and maturation, sperm motility and morphology, follicle development and maturation, embryo development and implantation. Then, we highlight the importance and diverse potential of lncRNAs as good diagnostic molecular biomarkers and therapeutic targets for infertility treatment.

The gene regulatory role of non-coding RNAs in non-obstructive azoospermia

Non-coding RNAs are classified as small non-coding RNAs, long non-coding RNAs and circular RNAs, which are involved in a variety of biological processes, including cell differentiation, proliferation, apoptosis and pathological conditions of various diseases. Many studies have shown that non-coding RNAs are related to spermatogenesis, maturation, apoptosis, function, etc. In addition, the expression of non-coding RNAs in testicular tissue and semen of patients with non-obstructive azoospermia was different. However, the role of non-coding RNAs in the pathogenesis of non-obstructive azoospermia has not been fully elucidated, and the role of non-coding RNAs in non-obstructive azoospermia is rarely reviewed. Here we summarize the research progress of non-coding RNAs in the pathogenesis of non-obstructive azoospermia.