MOTS-c promotes muscle differentiation in vitro

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.

Impact of Radiation Therapy on Serum Humanin and MOTS-c Levels in Patients with Lung or Breast Cancer

BACKGROUND

Lung and breast cancer are the most frequent causes of death from cancer globally. The objectives of this research were to evaluate the serum mitochondrial open reading frame of the 12S rRNA-c (MOTS-c) and humanin levels in lung or breast cancer patients, and investigate the impacts of radiation therapy on the circulating levels of these peptides.

METHODS

35 lung cancer patients, 34 breast cancer patients, and healthy volunteers as a control group were recruited in this prospective observatory research. Lung cancer patients with stage IIIA/IIIB were treated with paclitaxel-based chemotherapy plus radiotherapy (2 Gy per day, 30 times, 60 Gy total dose). Breast cancer stage IIA/IIB patients were treated with postoperative locoregional radiation therapy (2 Gy per day, 25 times, 50 Gy total dose). The ELISA method was used to detect serum humanin and MOTS-c levels during, before, and after radiotherapy.

RESULTS

We observed marked elevations in circulating MOTS-c, but not humanin levels in patients with lung cancer (P < 0.001). Radiation therapy led to a marked augmentation in MOTS-c levels in these patients (P < 0.001). On the other hand, there was a marked decline in humanin, but not MOTS-c, levels in breast cancer patients (P < 0.001).

CONCLUSION

Our research has shown, for the first time, that increased MOTS-c and decreased humanin levels play a role in lung cancer and breast cancer, respectively. Additionally, radiotherapy modifies MOTS-c levels in patients with lung, but not breast cancer.

Circulating levels of mitochondrial oxidative stress-related peptides MOTS-c and Romo1 in stable COPD: A cross-sectional study

Background

MOTS-c and Romo1 are mitochondrial peptides that are modulated by oxidative stress. No previous studies have explored circulating levels of MOTS-c in patients with chronic obstructive pulmonary disease (COPD).

Methods

We enrolled 142 patients with stable COPD and 47 smokers with normal lung function in an observational cross-sectional study. We assessed serum levels of both MOTS-c and Romo1 and associated these findings with clinical characteristics of COPD.

Results

Compared with smokers with normal lung function, patients with COPD had lower levels of MOTS-c (p = 0.02) and higher levels of Romo1 (p = 0.01). A multivariate logistic regression analysis revealed that above-median MOTS-c levels were positively associated with Romo1 levels (OR 1.075, 95% CI 1.005-1.150, p = 0.036), but no association was found with other COPD characteristics. Below-median levels of circulating MOTS-c were associated with oxygen desaturation (OR 3.25 95% CI 1.456-8.522, p = 0.005) and walking <350 meters (OR 3.246 95% CI 1.229-8.577, p = 0.018) in six-minute walk test. Above-median levels of Romo1 were positively associated with current smoking (OR 2.756, 95% CI 1.133-6.704, p = 0.025) and negatively associated with baseline oxygen saturation (OR 0.776 95% CI 0.641-0.939, p = 0.009).

Conclusions

Reduced levels of circulating MOTS-c and increased levels of Romo1 were detected in patients diagnosed with COPD. Low levels of MOTS-c were associated with oxygen desaturation and poorer exercise capacity using 6 min walk test. Romo1 was associated with current smoking and baseline oxygen saturation.

Trial registration

www.clinicaltrials.gov; No.: NCT04449419; URL: www.clinicaltrials.gov. Date of registration: June 26, 2020.

Mitochondria-derived peptide MOTS-c: effects and mechanisms related to stress, metabolism and aging

MOTS-c is a peptide encoded by the short open reading frame of the mitochondrial 12S rRNA gene. It is significantly expressed in response to stress or exercise and translocated to the nucleus, where it regulates the expression of stress adaptation-related genes with antioxidant response elements (ARE). MOTS-c mainly acts through the Folate-AICAR-AMPK pathway, thereby influencing energy metabolism, insulin resistance, inflammatory response, exercise, aging and aging-related pathologies. Because of the potential role of MOTS-c in maintaining energy and stress homeostasis to promote healthy aging, especially in view of the increasing aging of the global population, it is highly pertinent to summarize the relevant studies. This review summarizes the retrograde signaling of MOTS-c toward the nucleus, the regulation of energy metabolism, stress homeostasis, and aging-related pathological processes, as well as the underlying molecular mechanisms.

MOTS-c Functionally Prevents Metabolic Disorders

Mitochondrial-derived peptides are a family of peptides encoded by short open reading frames in the mitochondrial genome, which have regulatory effects on mitochondrial functions, gene expression, and metabolic homeostasis of the body. As a new member of the mitochondrial-derived peptide family, mitochondrial open reading frame of the 12S rRNA-c (MOTS-c) is regarding a peptide hormone that could reduce insulin resistance, prevent obesity, improve muscle function, promote bone metabolism, enhance immune regulation, and postpone aging. MOTS-c plays these physiological functions mainly through activating the AICAR-AMPK signaling pathways by disrupting the folate-methionine cycle in cells. Recent studies have shown that the above hormonal effect can be achieved through MOTS-c regulating the expression of genes such as GLUT4, STAT3, and IL-10. However, there is a lack of articles summarizing the genes and pathways involved in the physiological activity of MOTS-c. This article aims to summarize and interpret the interesting and updated findings of MOTS-c-associated genes and pathways involved in pathological metabolic processes. Finally, it is expected to develop novel diagnostic markers and treatment approaches with MOTS-c to prevent and treat metabolic disorders in the future.