Magnesium Influences Membrane Fusion during Myogenesis by Modulating Oxidative Stress in C2C12 Myoblasts

Association Between Serum Magnesium Levels and Glycemic Control in Type 2 Diabetes

Introduction

Serum magnesium is a crucial mineral within the human body. It is imperative for diabetic patients to maintain optimal serum magnesium levels. We focus on the relationship between glycemic control and serum magnesium in type 2 diabetes mellitus (T2DM).

Methods

The retrospective, observational, cross-sectional study comprised 1694 patients recruited from the People's Hospital of Yuxi. Fasting blood samples were collected for analysis, accompanied by the recording of participants' demographic characteristics. Patients were categorized into two groups based on whether their glycosylated hemoglobin (HbA1c) levels < 7%. A t-test was employed to identify significant differences between the two groups. Correlation coefficients were calculated using Pearson's method. A Logistic regression analysis was conducted to assess the association between variables and glycemic control. A linear regression analysis was performed to assess the relationship between serum magnesium levels and HbA1c.

Results

Patients with poor glycemic control exhibited elevated age, low-density lipoprotein (LDL-C), fasting plasma glucose (FPG), and homeostasis model assessment (HOMA-IR) compared to those with good glycemic control (P < 0.001). Additionally, total cholesterol (TC) levels were significantly higher in patients with poor glycemic control. Conversely, high-density lipoprotein (HDL-C) and serum magnesium levels were lower in patients with poor glycemic control. Serum magnesium levels exhibited negative correlations with HOMA-IR (r = -0.05, P < 0.05), HbA1c (r = -0.29, P < 0.05), and FPG (r = -0.20, P < 0.05). Moreover, serum magnesium was significantly associated with reduced odds of glycemic control (OR = 0.0005, 95% CI 0.0001-0.0027, P < 0.001).

Conclusion

The serum magnesium level in patients with T2DM is closely associated with glycemic control.

Low extracellular magnesium induces phenotypic and metabolic alterations in C2C12-derived myotubes

Magnesium (Mg) has a pivotal role in upholding skeletal muscle health and optimizing performance. Its deficiency decreases muscle strength, and an association has been reported between Mg intake and sarcopenia. To gain a comprehensive understanding of the repercussions arising from low Mg concentrations on muscle behavior, we employed an in vitro model utilizing C2C12-derived myotubes. Myotubes cultured in low Mg show a significant reduction of thickness and a concomitant down-regulation of myosin heavy chain (MyHC), Myog and Myomixer. In parallel, myotubes shape their metabolism. Glycolysis is inhibited and beta-oxidation increases. These metabolic changes are consistent with the increase of MyHC I (slow) vs. MyHC II (fast) expression. We identified an essential player in these changes, namely nitric oxide (NO), as the increase in NO production appeared to orchestrate the observed modifications in myotube behavior and metabolism under low Mg conditions. Understanding these underlying mechanisms may pave the way for targeted interventions to ameliorate muscle-related conditions associated with Mg deficiency and contribute to enhancing overall muscle health and function.

Nutrition and sarcopenia: Current knowledge domain and emerging trends

Objective

Non-pharmacological management like nutrient supplements has shown positive impacts on muscle mass and strength, which has burgeoned clinical and research interest internationally. The aim of this study was to analyze the current knowledge domain and emerging trends of nutrition-related research in sarcopenia and provide implications for future research and strategies to prevent or manage sarcopenia in the context of aging societies.

Materials and methods

Nutrition- and sarcopenia-related research were obtained from the Web of Science Core Collection (WoSCC) database from its inception to April 1, 2022. Performance analysis, science mapping, and thematic clustering were performed by using the software VOSviewer and R package “bibliometrix.” Bibliometric analysis (BA) guideline was applied in this study.

Results

A total of 8,110 publications were extracted and only 7,510 (92.60%) were selected for final analysis. The production trend in nutrition and sarcopenia research was promising, and 1,357 journals, 107 countries, 6,668 institutions, and 31,289 authors were identified in this field till 2021. Stable cooperation networks have formed in the field, but they are mostly divided by region and research topics. Health and sarcopenia, metabolism and nutrition, nutrition and exercise, body compositions, and physical performance were the main search themes.

Conclusions

This study provides health providers and scholars mapped out a comprehensive basic knowledge structure in the research in the field of nutrition and sarcopenia over the past 30 years. This study could help them quickly grasp research hotspots and choose future research projects.

Magnesium Homeostasis in Myogenic Differentiation-A Focus on the Regulation of TRPM7, MagT1 and SLC41A1 Transporters

Magnesium (Mg) is essential for skeletal muscle health, but little is known about the modulation of Mg and its transporters in myogenic differentiation. Here, we show in C2C12 murine myoblasts that Mg concentration fluctuates during their differentiation to myotubes, declining early in the process and reverting to basal levels once the cells are differentiated. The level of the Mg transporter MagT1 decreases at early time points and is restored at the end of the process, suggesting a possible role in the regulation of intracellular Mg concentration. In contrast, TRPM7 is rapidly downregulated and remains undetectable in myotubes. The reduced amounts of TRPM7 and MagT1 are due to autophagy, one of the proteolytic systems activated during myogenesis and essential for the membrane fusion process. Moreover, we investigated the levels of SLC41A1, which increase once cells are differentiated, mainly through transcriptional regulation. In conclusion, myogenesis is associated with alterations of Mg homeostasis finely tuned through the modulation of MagT1, TRPM7 and SLC41A1.

The relevance of magnesium homeostasis in COVID-19

Purpose

In less than one and a half year, the COVID-19 pandemic has nearly brought to a collapse our health care and economic systems. The scientific research community has concentrated all possible efforts to understand the pathogenesis of this complex disease, and several groups have recently emphasized recommendations for nutritional support in COVID-19 patients. In this scoping review, we aim at encouraging a deeper appreciation of magnesium in clinical nutrition, in view of the vital role of magnesium and the numerous links between the pathophysiology of SARS-CoV-2 infection and magnesium-dependent functions.

Methods

By searching PubMed and Google Scholar from 1990 to date, we review existing evidence from experimental and clinical studies on the role of magnesium in chronic non-communicable diseases and infectious diseases, and we focus on recent reports of alterations of magnesium homeostasis in COVID-19 patients and their association with disease outcomes. Importantly, we conduct a census on ongoing clinical trials specifically dedicated to disclosing the role of magnesium in COVID-19.

Results

Despite many methodological limitations, existing data seem to corroborate an association between deranged magnesium homeostasis and COVID-19, and call for further and better studies to explore the prophylactic or therapeutic potential of magnesium supplementation.

Conclusion

We propose to reconsider the relevance of magnesium, frequently overlooked in clinical practice. Therefore, magnesemia should be monitored and, in case of imbalanced magnesium homeostasis, an appropriate nutritional regimen or supplementation might contribute to protect against SARS-CoV-2 infection, reduce severity of COVID-19 symptoms and facilitate the recovery after the acute phase.

Editorial of Special Issue "Magnesium in Human Health and Disease"

The fundamental role of magnesium in human health is extensively discussed in the review by Fiorentini and colleagues [...].