Transcription factor Dmrt1 triggers the SPRY1-NF-κB pathway to maintain testicular immune homeostasis and male fertility.

Bacterial or viral infections, such as Brucella, mumps virus, herpes simplex virus, and Zika virus, destroy immune homeostasis of the testes, leading to spermatogenesis disorder and infertility. Of note, recent research shows that SARS-CoV-2 can infect male gonads and destroy Sertoli and Leydig cells, leading to male reproductive dysfunction. Due to the many side effects associated with antibiotic therapy, finding alternative treatments for inflammatory injury remains critical. Here, we found that Dmrt1 plays an important role in regulating testicular immune homeostasis. Knockdown of Dmrt1 in male mice inhibited spermatogenesis with a broad inflammatory response in seminiferous tubules and led to the loss of spermatogenic epithelial cells. Chromatin immunoprecipitation sequencing (ChIP-seq) and RNA sequencing (RNA-seq) revealed that Dmrt1 positively regulated the expression of Spry1, an inhibitory protein of the receptor tyrosine kinase (RTK) signaling pathway. Furthermore, immunoprecipitation-mass spectrometry (IP-MS) and co-immunoprecipitation (Co-IP) analysis indicated that SPRY1 binds to nuclear factor kappa B1 (NF-κB1) to prevent nuclear translocation of p65, inhibit activation of NF-κB signaling, prevent excessive inflammatory reaction in the testis, and protect the integrity of the blood-testis barrier. In view of this newly identified Dmrt1- Spry1-NF-κB axis mechanism in the regulation of testicular immune homeostasis, our study opens new avenues for the prevention and treatment of male reproductive diseases in humans and livestock.

The ACE2 expression in Sertoli cells and germ cells may cause male reproductive disorder after SARS-CoV-2 infection.

The serious coronavirus disease-2019 (COVID-19) was first reported in December 2019 in Wuhan, China. COVID-19 is an infectious disease caused by severe acute respiratory syndrome-coronavirus 2 (SARS-CoV-2). Angiotensin converting enzyme 2(ACE2) is the cellular receptor for SARS-CoV-2. Considering the critical roles of testicular cells for the transmission of genetic information between generations, we analyzed single-cell RNA-sequencing (scRNA-seq) data of adult human testis. The mRNA expression of ACE2 was expressed in both germ cells and somatic cells. Moreover, the positive rate of ACE2 in testes of infertile men was higher than normal, which indicates that SARS-CoV-2 may cause reproductive disorders through pathway activated by ACE2 and the men with reproductive disorder may easily to be infected by SARS-CoV-2. The expression level of ACE2 was related to the age, and the mid-aged with higher positive rate than young men testicular cells. Taken together, this research provides a biological background of the potential route for infection of SARS-CoV-2 and may enable rapid deciphering male-related reproductive disorders induced by COVID-19.