Seminal exosomal miR-210-3p as a potential marker of Sertoli cell damage in Varicocele.

Background: Varicocoele-associated stressors, such as hypoxia and heat, can damage cell function and viability, and some exosomal biomarkers released from impaired cells may reflect the cell status in testis.

Objectives: To find if seminal exosomal microRNAs can reflect the Sertoli cell function in varicocoele.

Materials And Methods: Experimental left varicocoele rat model was established (n = 24), and patients with different grades of varicocoele (n = 104) were enrolled. Primary rat Sertoli cells were isolated with enzymatic hydrolysis. Exosomes were isolated from primary rat Sertoli cells, rat epididymis tissue, and human seminal plasma with polymer-based precipitation method. Exosomal microRNAs were quantified with qPCR. Inhibin-B was detected with enzyme immunoassay. The correlation analysis between microRNA and inhibin-B was evaluated with Spearman's correlation.

Results: We screened 12 previously reported hypoxia-responsive microRNAs in the primary rat Sertoli cells and found that 4 exosomal microRNAs increased significantly in response to in vitro hypoxia treatment (P < .05). Of the 4 microRNAs, only miR-210-3p was upregulated in the rats with experimental varicocoele (P < .01). In the patients with varicocoele, we found that seminal exosomal miR-210-3p significantly increased in patients with grade II and III varicocoele (P < .01), and miR-210-3p negatively correlated with sperm count (P < .01) and seminal inhibin-B expression (r = -0.39, P < .01). For the 30 patients with microsurgical varicocelectomy, the operation notably decreased miR-210-3p (P < .01).

Discussion And Conclusion: Seminal exosomal miR-210-3p may be a novel, sensitive, and non-invasive biomarker of Sertoli cell damage in varicocoele.