Serum MOTS-C Levels are Decreased in Obese Children and Associated with Vascular Endothelial Function

The Mitochondrial-Derived Peptide MOTS-c May Refine Mortality and Cardiovascular Risk Prediction in Chronic Hemodialysis Patients: A Multicenter Cohort Study

INTRODUCTION

Uremic patients exhibit remarkably increased rates of mortality and cardiovascular (CV) events, but risk prediction in this setting remains difficult. Systemic mitochondrial dysfunction is pervasive in end-stage kidney disease and may contribute to CV complications. We tested the clinical significance of circulating MOTS-c, a small mitochondrial-derived peptide, as a biomarker for improving mortality and CV risk prediction in hemodialysis (HD) patients.

METHODS

We conducted a prospective, observational, multicenter study on 94 prevalent HD patients. The study endpoint was a composite of all-cause mortality and non-fatal CV events. The diagnostic and prognostic capacities of predictive models based on cohort-related risk factors were tested before and after the inclusion of MOTS-c.

RESULTS

MOTS-c levels were higher in HD patients than in controls (p < 0.001) and even more elevated (p = 0.01) in the 53 individuals experiencing the combined endpoint during follow-up (median duration: 26.5 months). MOTS-c was independently associated with the endpoint at either multivariate logistic (OR 1.020; 95% CI: 1.011-1.109; p = 0.03) or Cox regression analyses (HR 1.004; 95% CI: 1.000-1.025; p = 0.05) and the addition of this biomarker to prognostic models including the other cohort-related risk predictors (age, left ventricular mass, evidence of diastolic dysfunction, diabetes, pulse pressure) significantly improved the calibration, risk variability explanation, discrimination (receiver operating characteristic area under the curve from 0.727 to 0.743; C-index from 0.658 to 0.700), and particularly, the overall reclassification capacity (NRI 15.87%; p = 0.01).

CONCLUSIONS

In HD patients, the mitochondrial-derived peptide MOTS-c may impart significant information to refine CV risk prediction, beyond cohort-related risk factors. Future investigations are needed to generalize these findings in larger and more heterogeneous cohorts.

MOTS-c regulates pancreatic alpha and beta cell functions in vitro

The aim of this study is to determine the influence of the mitochondrial open-reading-frame of the twelve S rRNA-c (MOTS-c) peptide on pancreatic cell physiology. Moreover, in this study, we examined the changes in MOTS-c secretion and expression under different conditions. Our experiments were conducted using laboratory cell line cultures, specifically the INS-1E and αTC-1 cell lines, which represent β and α pancreatic cells, respectively. As the pancreas is an endocrine organ, we also tested its hormone regulation capabilities. Furthermore, we assessed the secretion of MOTS-c after incubating the cells with glucose and free fatty acids. Additionally, we examined key cell culture parameters such as cell viability, proliferation, and apoptosis. The results obtained from this study show that MOTS-c has a significant impact on the physiology of pancreatic cells. Specifically, it lowers insulin secretion and expression in INS-1E cells and enhances glucagon secretion and expression in αTC-1 cells. Furthermore, MOTS-c affects cell viability and apoptosis. Interestingly, insulin and glucagon affect the MOTS-c secretion as well as glucose and free fatty acids. These experiments clearly show that MOTS-c is an important regulator of pancreatic metabolism, and there are numerous properties of MOTS-c yet to be discovered.