Basic Study
Copyright ©The Author(s) 2024. Published by Baishideng Publishing Group Inc. All rights reserved.
World J Diabetes. Jul 15, 2024; 15(7): 1589-1602
Published online Jul 15, 2024. doi: 10.4239/wjd.v15.i7.1589
Interactions between myoblasts and macrophages under high glucose milieus result in inflammatory response and impaired insulin sensitivity
Wei Luo, Yue Zhou, Li-Ying Wang, Lei Ai
Wei Luo, Department of Sports and Health Sciences, Nanjing Sport Institute, Nanjing 210014, Jiangsu Province, China
Yue Zhou, Li-Ying Wang, Department of Exercise Physiology, Beijing Sport University, Beijing 100084, China
Lei Ai, Department of Sports Physiology Research, Jiangsu Research Institute of Sports Science, Nanjing 210033, Jiangsu Province, China
Author contributions: Ai L, Luo W and Zhou Y designed the research study; Luo W, Zhou Y, Wang LY and Ai L performed the research; Luo W, Ai L and Wang LY analyzed the data and wrote the manuscript; All authors have read and approve the final manuscript.
Supported by National Natural Science Foundation of China, No. 32200944; “Qing Lan” Project of Jiangsu Province; and the Jiangsu Research Institute of Sports Science Foundation, No. BM-2023-03.
Institutional animal care and use committee statement: All procedures involving animals were reviewed and approved by the Institutional Animal Care and Use Committee of Nanjing Sport Institute (Protocol No. GZRDW-2022-02).
Conflict-of-interest statement: All the authors report no relevant conflicts of interest for this article.
Data sharing statement: The data are available on reasonable request at ailei_982@163.com.
ARRIVE guidelines statement: The authors have read the ARRIVE Guidelines, and the manuscript was prepared and revised according to the ARRIVE Guidelines.
Open-Access: This article is an open-access article that was selected by an in-house editor and fully peer-reviewed by external reviewers. It is distributed in accordance with the Creative Commons Attribution NonCommercial (CC BY-NC 4.0) license, which permits others to distribute, remix, adapt, build upon this work non-commercially, and license their derivative works on different terms, provided the original work is properly cited and the use is non-commercial. See: https://creativecommons.org/Licenses/by-nc/4.0/
Corresponding author: Lei Ai, PhD, Associate Research Scientist, Department of Sports Physiology Research, Jiangsu Research Institute of Sports Science, No. 169 Xianlin Avenue, Nanjing 210033, Jiangsu Province, China. ailei_982@163.com
Received: February 22, 2024
Revised: April 28, 2024
Accepted: May 20, 2024
Published online: July 15, 2024
Processing time: 136 Days and 18.6 Hours
Abstract
BACKGROUND

Skeletal muscle handles about 80% of insulin-stimulated glucose uptake and become the major organ occurring insulin resistance (IR). Many studies have confirmed the interactions between macrophages and skeletal muscle regulated the inflammation and regeneration of skeletal muscle. However, despite of the decades of research, whether macrophages infiltration and polarization in skeletal muscle under high glucose (HG) milieus results in the development of IR is yet to be elucidated. C2C12 myoblasts are well-established and excellent model to study myogenic regulation and its responses to stimulation. Further exploration of macrophages' role in myoblasts IR and the dynamics of their infiltration and polarization is warranted.

AIM

To evaluate interactions between myoblasts and macrophages under HG, and its effects on inflammation and IR in skeletal muscle.

METHODS

We detected the polarization status of macrophages infiltrated to skeletal muscles of IR mice by hematoxylin and eosin and immunohistochemical staining. Then, we developed an in vitro co-culture system to study the interactions between myoblasts and macrophages under HG milieus. The effects of myoblasts on macrophages were explored through morphological observation, CCK-8 assay, Flow Cytometry, and enzyme-linked immunosorbent assay. The mediation of macrophages to myogenesis and insulin sensitivity were detected by morphological observation, CCK-8 assay, Immunofluorescence, and 2-NBDG assay.

RESULTS

The F4/80 and co-localization of F4/80 and CD86 increased, and the myofiber size decreased in IR group (P < 0.01, g = 6.26). Compared to Mc group, F4/80+CD86+CD206- cells, tumor necrosis factor-α (TNFα), inerleukin-1β (IL-1β) and IL-6 decreased, and IL-10 increased in McM group (P < 0.01, g > 0.8). In McM + HG group, F4/80+CD86+CD206- cells, monocyte chemoattractant protein 1, TNFα, IL-1β and IL-6 were increased, and F4/80+CD206+CD86- cells and IL-10 were decreased compared with Mc + HG group and McM group (P < 0.01, g > 0.8). Compered to M group, myotube area, myotube number and E-MHC were increased in MMc group (P < 0.01, g > 0.8). In MMc + HG group, myotube area, myotube number, E-MHC, GLUT4 and glucose uptake were decreased compared with M + HG group and MMc group (P < 0.01, g > 0.8).

CONCLUSION

Interactions between myoblasts and macrophages under HG milieus results in inflammation and IR, which support that the macrophage may serve as a promising therapeutic target for skeletal muscle atrophy and IR.

Keywords: Macrophages phenotype; Myoblasts; Cross-talk; Glucose toxicity; Chronic inflammation; Insulin sensitivity

Core Tip: This study demonstrated interactions between myoblasts and macrophages under high glucose (HG) milieus induced pro-inflammatory M1 polarization of macrophages to exacerbate inflammatory response. Subsequently, chronic inflammation induced by HG-related M1 macrophages damaged myogenesis and insulin sensitivity in myoblasts. Ultimately, interactions between myoblasts and macrophages resulted in skeletal muscle insulin resistance (IR), which supported macrophage may serve as a promising therapeutic target for skeletal muscle atrophy and IR. This is the first research about the mediation of macrophages to HG-related myogenic inhibition and IR in myoblasts, which provide new insights into the prevention and treatment of skeletal muscle atrophy and IR.