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Oh H, Park SY, Cho W, Abd El-Aty AM, Hacimuftuoglu A, Kwon CH, Jeong JH, Jung TW. Sclerostin aggravates insulin signaling in skeletal muscle and hepatic steatosis via upregulation of ER stress by mTOR-mediated inhibition of autophagy under hyperlipidemic conditions. J Cell Physiol 2022; 237:4226-4237. [PMID: 36087347 DOI: 10.1002/jcp.30873] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/13/2022] [Revised: 08/19/2022] [Accepted: 08/24/2022] [Indexed: 11/05/2022]
Abstract
Recently, sclerostin (SCL), a circulating glycoprotein, was proposed to be a novel myokine involved in developing metabolic disorders. The association between SCL levels and insulin resistance in skeletal muscle, liver, and adipose tissue was studied in individuals with aggravated glucose tolerance. Thus, we hypothesized that elevated circulating SCL might affect skeletal muscle insulin signaling and hepatic lipid metabolism, and aimed to investigate the effects of SCL on skeletal muscle insulin resistance and hepatic steatosis in obesity using in vitro and in vivo experimental models under hyperlipidemic conditions. In the current study, we found elevated SCL messenger RNA expression levels in myocytes in obese patients. In addition to a higher blood level, SCL was expressed at an elevated level in the skeletal muscle of mice fed a high-fat diet (HFD). Higher SCL release levels and expression were also noticed in palmitate-treated C2C12 myocytes. SCL suppression by in vivo transfection improves skeletal muscle insulin resistance and hepatic steatosis in HFD-fed mice. The treatment of C2C12 myocytes with recombinant SCL aggravated insulin signaling. Furthermore, treatment with SCL augmented lipogenic lipid deposition in human primary hepatocytes. Treatment with SCL upregulated mammalian target of rapamycin (mTOR) phosphorylation and suppressed autophagy markers, thereby causing endoplasmic reticulum (ER) stress. 4-Phenylbutyric acid, a pharmacological ER stress inhibitor, abolished the effects of SCL on insulin signaling in C2C12 myocytes and lipid accumulation in primary hepatocytes. In conclusion, SCL promotes skeletal muscle insulin resistance and hepatic steatosis by upregulating ER stress via the mTOR/autophagy-mediated pathway. The present study suggests that antagonizing SCL might be a novel therapeutic strategy for simultaneously managing insulin resistance and hepatic steatosis in obesity.
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Affiliation(s)
- Heeseung Oh
- Department of Pharmacology, College of Medicine, Chung-Ang University, Seoul, Republic of Korea
| | - Seung Yeon Park
- Department of Pharmacology, College of Medicine, Chung-Ang University, Seoul, Republic of Korea.,Department of Global Innovative Drugs, Graduate School of Chung-Ang University, Seoul, Republic of Korea
| | - Wonjun Cho
- Department of Pharmacology, College of Medicine, Chung-Ang University, Seoul, Republic of Korea
| | - A M Abd El-Aty
- Department of Pharmacology, Faculty of Veterinary Medicine, Cairo University, Giza, Egypt.,Department of Medical Pharmacology, Medical Faculty, Ataturk University, Erzurum, Turkey
| | - Ahmet Hacimuftuoglu
- Department of Medical Pharmacology, Medical Faculty, Ataturk University, Erzurum, Turkey
| | | | - Ji Hoon Jeong
- Department of Pharmacology, College of Medicine, Chung-Ang University, Seoul, Republic of Korea.,Department of Global Innovative Drugs, Graduate School of Chung-Ang University, Seoul, Republic of Korea
| | - Tae Woo Jung
- Department of Pharmacology, College of Medicine, Chung-Ang University, Seoul, Republic of Korea
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The role of liver kinase B1 in tumor progression through regulation of lipid metabolism. CLINICAL & TRANSLATIONAL ONCOLOGY : OFFICIAL PUBLICATION OF THE FEDERATION OF SPANISH ONCOLOGY SOCIETIES AND OF THE NATIONAL CANCER INSTITUTE OF MEXICO 2022; 24:2045-2054. [PMID: 35896782 PMCID: PMC9522762 DOI: 10.1007/s12094-022-02863-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 03/12/2022] [Accepted: 05/19/2022] [Indexed: 10/30/2022]
Abstract
The somatic mutation of liver kinase B1 (LKB1) has been implicated in various tumors, which is reflected in the survival, proliferation, and metastasis of tumor cells. However, the regulation of LKB1 in lipid metabolism, a process that is involved in tumor progression is not completely clear. We conclude that LKB1 deficiency results in abnormal expression and activation of multiple molecules related to lipid metabolism which locate downstream of AMP-activated protein kinase (AMPK) or salt-induced kinase (SIK). Abnormal lipid metabolism induced by LKB1 deficiency contributes to the proliferation and metastasis of tumor cells through energy regulation.
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Zhang P, Wang W, Mao M, Gao R, Shi W, Li D, Calderone R, Sui B, Tian X, Meng X. Similarities and Differences: A Comparative Review of the Molecular Mechanisms and Effectors of NAFLD and AFLD. Front Physiol 2021; 12:710285. [PMID: 34393826 PMCID: PMC8362097 DOI: 10.3389/fphys.2021.710285] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/18/2021] [Accepted: 06/29/2021] [Indexed: 12/12/2022] Open
Abstract
Non-alcoholic fatty liver disease (NAFLD) and alcoholic fatty liver disease (AFLD) are the most prevalent metabolic liver diseases globally. Due to the complex pathogenic mechanisms of NAFLD and AFLD, no specific drugs were approved at present. Lipid accumulation, oxidative stress, insulin resistance, inflammation, and dietary habits are all closely related to the pathogenesis of NAFLD and AFLD. However, the mechanism that promotes disease progression has not been fully elucidated. Meanwhile, the gut microbiota and their metabolites also play an important role in the pathogenesis and development of NAFLD and AFLD. This article comparatively reviewed the shared and specific signaling pathways, clinical trials, and potential intervention effectors of NAFLD and AFLD, revealing their similarities and differences. By comparing the shared and specific molecular regulatory mechanisms, this paper provides mutual reference strategies for preventing and treating NAFLD, AFLD, and related metabolic diseases. Furthermore, it provides enlightenment for discovering novel therapies of safe and effective drugs targeting the metabolic liver disease.
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Affiliation(s)
- Pengyi Zhang
- School of Sports and Health, Shandong Sport University, Jinan, China
| | - Weiya Wang
- School of Sports and Health, Shandong Sport University, Jinan, China.,Shandong Academy of Pharmaceutical Science, Jinan, China
| | - Min Mao
- Department of Allied Health, University of North Carolina at Chapel Hill, Chapel Hill, NC, United States
| | - Ruolin Gao
- School of Sports and Health, Shandong Sport University, Jinan, China
| | - Wenting Shi
- School of Sports and Health, Shandong Sport University, Jinan, China
| | - Dongmei Li
- Department of Microbiology and Immunology, Georgetown University Medical Center, Washington, DC, United States
| | - Richard Calderone
- Department of Microbiology and Immunology, Georgetown University Medical Center, Washington, DC, United States
| | - Bo Sui
- School of Sports and Health, Shandong Sport University, Jinan, China
| | - Xuewen Tian
- School of Sports and Health, Shandong Sport University, Jinan, China
| | - Xiangjing Meng
- Shandong Academy of Pharmaceutical Science, Jinan, China
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