Abstract
Coronavirus disease 2019 (COVID-19), caused by severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2), is outbreaking globally. SARS-CoV-2 invades host cells via angiotensin-converting enzyme II (ACE2) and causes multiple-organ injury. Autopsy studies indicated that the testis of patients with COVID-19 exhibited various degrees of spermatogenic cell reduction and injury, but the composition of ACE2-expressing cells and their proportion in the testes have remained to be determined. Recent clinical evidence suggested that the ratio of male sex hormones in males with COVID-19 was significantly changed. The present study aimed to explore whether SARS-CoV-2 is able to damage the male reproductive system. For this, the ACE2-expressing cell composition and proportion in male testes were analyzed using single-cell RNA sequencing (RNA-seq) datasets downloaded from the Gene Expression Omnibus (GEO) database and immunohistochemical (IHC) staining. The single-cell RNA-seq data indicated that ACE2 mRNA was highly expressed in myoid cells, Leydig cells and spermatogenic cells, accounting for 5.45, 1.24 and 0.423% of adult testicular cells. ACE2 mRNA-expressing Sertoli cells, spermatogenic cells and myoid cells accounted for 5.00, 0.56 and 0.73% of infant testicular cells. IHC demonstrated that ACE2 protein was also highly expressed in testicular tissues. In conclusion, the present results demonstrated that testicular injury may be missed by clinicians in patients with COVID-19 and male reproductive function should be closely followed up.