Evaluation of Serum Humanin and MOTS-c Peptide Levels in Patients with COVID-19 and Healthy Subjects.

BACKGROUND: Coronavirus Disease 2019 (COVID-19) is a life-threatening and persistent pandemic with high rates of mortality and morbidity. Although a dysfunction in the mitochondria occurs in COVID-19 pathogenesis, the contribution of mitochondrial-derived peptides to its pathophysiology has not yet been completely elucidated. The goals of this research were to assess the circulating humanin and mitochondrial open reading frame of the 12S rRNA-c (MOTS-c) levels in COVID-19 patients and explore the effects of antiviral drug therapy on these peptide levels. METHODS: Thirty adult COVID-19 patients and 32 gender-matched healthy volunteers were enrolled in this study. Circulating humanin and MOTS-c levels were detected using the ELISA method during pretreatment (before drug therapy) and post-treatment (on the 7th day of drug therapy). RESULTS: We found that there was significant attenuation of the serum humanin levels in COVID-19 patients (P < 0.001). However, we detected a significant augmentation in serum MOTS-c levels when compared to controls (P < 0.01 for pre-treatment and P < 0.001 for post-treatment). Interestingly, antiviral drug therapy did not modify the serum MOTS-c and humanin levels. CONCLUSION: Our findings suggest that MOTS-c and humanin were involved in the COVID-19 pathogenesis. Our data may also imply that elevated MOTS-c could act as a compensatory mechanism to eliminate the effects of decreased humanin levels.

Effects of antiviral drug therapy on dynamic thiol/disulphide homeostasis and nitric oxide levels in COVID-19 patients.

The novel coronavirus disease 2019 (COVID-19) has led to a serious global pandemic. Although an oxidative stress imbalance occurs in COVID-19 patients, the contributions of thiol/disulphide homeostasis and nitric oxide (NO) generation to the pathogenesis of COVID-19 have been poorly identified. Therefore, the aim of this study was to evaluate the effects of antiviral drug therapy on the serum dynamics of thiol/disulphide homeostasis and NO levels in COVID-19 patients. A total of 50 adult patients with COVID-19 and 43 sex-matched healthy control subjects were enrolled in this prospective study. Venous blood samples were collected immediately on admission to the hospital within 24 h after the diagnosis (pre-treatment) and at the 15th day of drug therapy (post-treatment). Serum native thiol and total thiol levels were measured, and the amounts of dynamic disulphide bonds and related ratios were calculated. The average pre-treatment total and native thiol levels were significantly lower than the post-treatment values (P < 0.001 for all). We observed no significant changes in disulphide levels or disulphide/total thiol, disulphide/native thiol, or native thiol/total thiol ratios between pre- and post-treatments. There was also a significant increase in serum NO levels in the pre-treatment values when compared to control (P < 0.001) and post-treatment measurements (P < 0.01). Our results strongly suggest that thiol/disulphide homeostasis and nitrosative stress can contribute to the pathogenesis of COVID-19. This study was the first to show that antiviral drug therapy can prevent the depletion in serum thiol levels and decrease serum NO levels in COVID-19 patients.