Physiological implications of COVID-19 in reproduction: angiotensin-converting enzyme 2 a key player

Evaluation of testicles by sonoelastography in men recovering after Covid-19 disease

INTRODUCTION

Testicular cells, seminiferous tubule cells, spermatogonia, Leydig and Sertoli cells showing angiotensin-converting enzyme 2 expression have the potential to be targets and to be damaged by the coronavirus. We aimed to use Two-Dimensional Shear Wave Elastography (2D-SWE) as an effective technique to identify parenchymal damage in the testicles of patients recovering from COVID-19 infection.

METHODS

35 Male patients (group 1) who recovered after COVID-19 infection between 4 and 12 weeks were included in this prospective study. Before 2D-SWE, these male patients were confirmed with control Rt-PCR test negativity. In addition, the first Rt-PCR test positivity of these patients was confirmed. A control group was formed of 31 healthy subjects (group 2). These two groups were compared in terms of age, volume of each testis, and SWE values. Ultrasound including SWE was applied to all the testes. A total of 9 measurements were taken as 3 SWE measurements from each third of the testis (superior, mid, inferior) and the average of these was calculated. Data obtained in the study were analyzed statistically. A value of p < 0.05 was accepted as statistically significant.

RESULTS

The mean SWE values for the right testis and the left testis were determined to be statistically significantly higher in Group 1 than in Group 2, respectively (p < 0.001, p < 0.001).

CONCLUSION

There is an increase in testicular stiffness in males who have recovered from COVID-19 infection. The underlying cause of testicular damage is changes at the cellular level. The 2D-SWE technique can predict potential testicular parenchymal damage in male patients recovering from COVID-19 infection.

IMPLICATIONS FOR PRACTICE

Two-Dimensional Shear Wave Elastography (2D-SWE) seems to be a promising imaging technique in the evaluation of testis parenchyma.

Spike protein of SARS-CoV-2 suppresses gonadotrophin secretion from bovine anterior pituitaries

Coronavirus disease (COVID-19), the ongoing global pandemic, is caused by the severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2). Recent evidence shows that the virus utilizes angiotensin-converting enzyme 2 (ACE2) as a spike protein receptor for entry into target host cells. The bovine ACE2 contains key residues for binding to the spike protein receptor-binding domain. This study evaluated the hypothesis that bovine gonadotroph expresses ACE2, and spike protein suppresses luteinizing hormone (LH) and follicle-stimulating hormone (FSH) secretion from cultured bovine anterior pituitary (AP) cells. ACE2 mRNA expression and ACE2 protein expression were detected in the bovine AP cells using reverse transcription PCR and western blot analysis. Immunofluorescence microscopy analysis with the anti-ACE2 antibody revealed the co-localization of ACE2 and gonadotropin-releasing hormone (GnRH) receptor on the gonadotroph plasma membrane. Approximately 90% of GnRH receptor-positive cells expressed ACE2, and approximately 46% of ACE2-positive cells expressed the GnRH receptor. We cultured bovine AP cells for 3.5 days and treated them with increasing concentrations (0, 0.07, 0.7, or 7 pM) of recombinant spike protein having both S1 and S2 regions. The spike protein (0.07-7 pM) suppressed both basal and GnRH-induced LH secretion (P < 0.05). Spike protein (0.7-7 pM) suppressed GnRH-induced (P < 0.05), but not basal FSH secretion. In contrast, pre-treatment with ERK 1/2/5 inhibitor (U0126) partially restored the GnRH-induced LH and FSH secretion from the spike protein suppression. Collectively, the results indicate that gonadotrophs express ACE2, a receptor for coronavirus 2 spike protein, which in turn suppresses LH and FSH secretion from AP cells.