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Yao YX, Yu YJ, Dai S, Zhang CY, Xue XY, Zhou ML, Yao CH, Li YX. Kaempferol efficacy in metabolic diseases: Molecular mechanisms of action in diabetes mellitus, obesity, non-alcoholic fatty liver disease, steatohepatitis, and atherosclerosis. Biomed Pharmacother 2024; 175:116694. [PMID: 38713943 DOI: 10.1016/j.biopha.2024.116694] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/03/2024] [Revised: 04/24/2024] [Accepted: 04/29/2024] [Indexed: 05/09/2024] Open
Abstract
The incidence of metabolic diseases has progressively increased, which has a negative impact on human health and life safety globally. Due to the good efficacy and limited side effects, there is growing interest in developing effective drugs to treat metabolic diseases from natural compounds. Kaempferol (KMP), an important flavonoid, exists in many vegetables, fruits, and traditional medicinal plants. Recently, KMP has received widespread attention worldwide due to its good potential in the treatment of metabolic diseases. To promote the basic research and clinical application of KMP, this review provides a timely and comprehensive summary of the pharmacological advances of KMP in the treatment of four metabolic diseases and its potential molecular mechanisms of action, including diabetes mellitus, obesity, non-alcoholic fatty liver disease (NAFLD)/nonalcoholic steatohepatitis (NASH), and atherosclerosis. According to the research, KMP shows remarkable therapeutic effects on metabolic diseases by regulating multiple signaling transduction pathways such as NF-κB, Nrf2, AMPK, PI3K/AKT, TLR4, and ER stress. In addition, the most recent literature on KMP's natural source, pharmacokinetics studies, as well as toxicity and safety are also discussed in this review, thus providing a foundation and evidence for further studies to develop novel and effective drugs from natural compounds. Collectively, our manuscript strongly suggested that KMP could be a promising candidate for the treatment of metabolic diseases.
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Affiliation(s)
- Yu-Xin Yao
- State Key Laboratory of Southwestern Chinese Medicine Resources, Chengdu 611137, China; School of Pharmacy, Chengdu University of Traditional Chinese Medicine, Chengdu 611137, China; Key Laboratory of Standardization for Chinese Herbal Medicine, Ministry of Education, Chengdu 611137, China
| | - Yu-Jie Yu
- State Key Laboratory of Southwestern Chinese Medicine Resources, Chengdu 611137, China; School of Pharmacy, Chengdu University of Traditional Chinese Medicine, Chengdu 611137, China; Key Laboratory of Standardization for Chinese Herbal Medicine, Ministry of Education, Chengdu 611137, China
| | - Shu Dai
- State Key Laboratory of Southwestern Chinese Medicine Resources, Chengdu 611137, China; School of Pharmacy, Chengdu University of Traditional Chinese Medicine, Chengdu 611137, China; Key Laboratory of Standardization for Chinese Herbal Medicine, Ministry of Education, Chengdu 611137, China
| | - Chao-Yang Zhang
- State Key Laboratory of Southwestern Chinese Medicine Resources, Chengdu 611137, China; School of Pharmacy, Chengdu University of Traditional Chinese Medicine, Chengdu 611137, China; Key Laboratory of Standardization for Chinese Herbal Medicine, Ministry of Education, Chengdu 611137, China
| | - Xin-Yan Xue
- State Key Laboratory of Southwestern Chinese Medicine Resources, Chengdu 611137, China; School of Pharmacy, Chengdu University of Traditional Chinese Medicine, Chengdu 611137, China; Key Laboratory of Standardization for Chinese Herbal Medicine, Ministry of Education, Chengdu 611137, China
| | - Meng-Ling Zhou
- State Key Laboratory of Southwestern Chinese Medicine Resources, Chengdu 611137, China; School of Pharmacy, Chengdu University of Traditional Chinese Medicine, Chengdu 611137, China; Key Laboratory of Standardization for Chinese Herbal Medicine, Ministry of Education, Chengdu 611137, China
| | - Chen-Hao Yao
- State Key Laboratory of Southwestern Chinese Medicine Resources, Chengdu 611137, China; School of Pharmacy, Chengdu University of Traditional Chinese Medicine, Chengdu 611137, China; Key Laboratory of Standardization for Chinese Herbal Medicine, Ministry of Education, Chengdu 611137, China
| | - Yun-Xia Li
- State Key Laboratory of Southwestern Chinese Medicine Resources, Chengdu 611137, China; School of Pharmacy, Chengdu University of Traditional Chinese Medicine, Chengdu 611137, China; Key Laboratory of Standardization for Chinese Herbal Medicine, Ministry of Education, Chengdu 611137, China.
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Miyata M, Takeda K, Nagira S, Sugiura Y. Trimethylamine N-oxide ameliorates hepatic damage including reduction of hepatic bile acids and cholesterol in Fxr-null mice. Int J Food Sci Nutr 2024; 75:385-395. [PMID: 38690724 DOI: 10.1080/09637486.2024.2346765] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/31/2023] [Accepted: 04/17/2024] [Indexed: 05/02/2024]
Abstract
There are conflicting animal experiments on the effect of trimethylamine N-oxide (TMAO), the dietary metabolite, on non-alcoholic fatty liver disease (NAFLD). This study aims to determine the effect of TMAO on NAFLD. A diet containing 0.3% TMAO was fed to farnesoid X receptor (Fxr)-null mice, a model of NAFLD, for 13 weeks. Fxr-null mice fed TMAO showed significant reductions in liver damage markers but not wild-type mice. Hepatic bile acid and cholesterol levels were significantly decreased, and triacylglycerol levels tended to decrease in TMAO-fed Fxr-null mice. Changes in mRNA levels of hepatic bile acid and cholesterol transporters and synthetic enzymes were observed, which could explain the decreased hepatic bile acid and cholesterol levels in Fxr-null mice given the TMAO diet but not in the wild-type mice. These results suggest that TMAO intake ameliorates liver damage in Fxr-null mice, further altering bile acid/cholesterol metabolism in an FXR-independent manner.
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Affiliation(s)
- Masaaki Miyata
- Department of Food Science and Technology, National Research and Development Agency, Japan Fisheries Research and Education Agency, National Fisheries University, Shimonoseki, Japan
| | - Kento Takeda
- Department of Food Science and Technology, National Research and Development Agency, Japan Fisheries Research and Education Agency, National Fisheries University, Shimonoseki, Japan
| | - Sayuri Nagira
- Department of Food Science and Technology, National Research and Development Agency, Japan Fisheries Research and Education Agency, National Fisheries University, Shimonoseki, Japan
| | - Yoshimasa Sugiura
- Department of Food Science and Technology, National Research and Development Agency, Japan Fisheries Research and Education Agency, National Fisheries University, Shimonoseki, Japan
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Kong L, Zhao Q, Jiang X, Hu J, Jiang Q, Sheng L, Peng X, Wang S, Chen Y, Wan Y, Hou S, Liu X, Ma C, Li Y, Quan L, Chen L, Cui B, Li P. Trimethylamine N-oxide impairs β-cell function and glucose tolerance. Nat Commun 2024; 15:2526. [PMID: 38514666 PMCID: PMC10957989 DOI: 10.1038/s41467-024-46829-0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/11/2023] [Accepted: 03/12/2024] [Indexed: 03/23/2024] Open
Abstract
β-Cell dysfunction and β-cell loss are hallmarks of type 2 diabetes (T2D). Here, we found that trimethylamine N-oxide (TMAO) at a similar concentration to that found in diabetes could directly decrease glucose-stimulated insulin secretion (GSIS) in MIN6 cells and primary islets from mice or humans. Elevation of TMAO levels impairs GSIS, β-cell proportion, and glucose tolerance in male C57BL/6 J mice. TMAO inhibits calcium transients through NLRP3 inflammasome-related cytokines and induced Serca2 loss, and a Serca2 agonist reversed the effect of TMAO on β-cell function in vitro and in vivo. Additionally, long-term TMAO exposure promotes β-cell ER stress, dedifferentiation, and apoptosis and inhibits β-cell transcriptional identity. Inhibition of TMAO production improves β-cell GSIS, β-cell proportion, and glucose tolerance in both male db/db and choline diet-fed mice. These observations identify a role for TMAO in β-cell dysfunction and maintenance, and inhibition of TMAO could be an approach for the treatment of T2D.
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Affiliation(s)
- Lijuan Kong
- State Key Laboratory of Bioactive Substance and Function of Natural Medicines, Institute of Materia Medica, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing, China
- Diabetes Research Center of Chinese Academy of Medical Sciences, Beijing, China
- CAMS Key Laboratory of Molecular Mechanism and Target Discovery of Metabolic Disorder and Tumorigenesis, Beijing, China
| | - Qijin Zhao
- State Key Laboratory of Bioactive Substance and Function of Natural Medicines, Institute of Materia Medica, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing, China
- Diabetes Research Center of Chinese Academy of Medical Sciences, Beijing, China
- CAMS Key Laboratory of Molecular Mechanism and Target Discovery of Metabolic Disorder and Tumorigenesis, Beijing, China
| | - Xiaojing Jiang
- State Key Laboratory of Bioactive Substance and Function of Natural Medicines, Institute of Materia Medica, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing, China
- Diabetes Research Center of Chinese Academy of Medical Sciences, Beijing, China
- CAMS Key Laboratory of Molecular Mechanism and Target Discovery of Metabolic Disorder and Tumorigenesis, Beijing, China
| | - Jinping Hu
- State Key Laboratory of Bioactive Substance and Function of Natural Medicines, Institute of Materia Medica, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing, China
| | - Qian Jiang
- State Key Laboratory of Bioactive Substance and Function of Natural Medicines, Institute of Materia Medica, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing, China
- Diabetes Research Center of Chinese Academy of Medical Sciences, Beijing, China
- CAMS Key Laboratory of Molecular Mechanism and Target Discovery of Metabolic Disorder and Tumorigenesis, Beijing, China
| | - Li Sheng
- State Key Laboratory of Bioactive Substance and Function of Natural Medicines, Institute of Materia Medica, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing, China
| | - Xiaohong Peng
- College of Future Technology, Institute of Molecular Medicine, National Biomedical Imaging Center, Peking University, 100871, Beijing, China
- Beijing Key Laboratory of Cardiometabolic Molecular Medicine, Peking University, 100871, Beijing, China
| | - Shusen Wang
- Tianjin First Central Hospital, Tianjin, China
| | - Yibing Chen
- State Key Laboratory of Bioactive Substance and Function of Natural Medicines, Institute of Materia Medica, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing, China
- Diabetes Research Center of Chinese Academy of Medical Sciences, Beijing, China
- CAMS Key Laboratory of Molecular Mechanism and Target Discovery of Metabolic Disorder and Tumorigenesis, Beijing, China
| | - Yanjun Wan
- State Key Laboratory of Bioactive Substance and Function of Natural Medicines, Institute of Materia Medica, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing, China
- Diabetes Research Center of Chinese Academy of Medical Sciences, Beijing, China
- CAMS Key Laboratory of Molecular Mechanism and Target Discovery of Metabolic Disorder and Tumorigenesis, Beijing, China
| | - Shaocong Hou
- State Key Laboratory of Bioactive Substance and Function of Natural Medicines, Institute of Materia Medica, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing, China
- Diabetes Research Center of Chinese Academy of Medical Sciences, Beijing, China
- CAMS Key Laboratory of Molecular Mechanism and Target Discovery of Metabolic Disorder and Tumorigenesis, Beijing, China
| | - Xingfeng Liu
- State Key Laboratory of Bioactive Substance and Function of Natural Medicines, Institute of Materia Medica, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing, China
- Diabetes Research Center of Chinese Academy of Medical Sciences, Beijing, China
- CAMS Key Laboratory of Molecular Mechanism and Target Discovery of Metabolic Disorder and Tumorigenesis, Beijing, China
| | - Chunxiao Ma
- State Key Laboratory of Bioactive Substance and Function of Natural Medicines, Institute of Materia Medica, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing, China
- Diabetes Research Center of Chinese Academy of Medical Sciences, Beijing, China
- CAMS Key Laboratory of Molecular Mechanism and Target Discovery of Metabolic Disorder and Tumorigenesis, Beijing, China
| | - Yan Li
- State Key Laboratory of Bioactive Substance and Function of Natural Medicines, Institute of Materia Medica, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing, China
| | - Li Quan
- Beijing Key Laboratory of Cardiometabolic Molecular Medicine, Peking University, 100871, Beijing, China
| | - Liangyi Chen
- College of Future Technology, Institute of Molecular Medicine, National Biomedical Imaging Center, Peking University, 100871, Beijing, China
- Beijing Key Laboratory of Cardiometabolic Molecular Medicine, Peking University, 100871, Beijing, China
| | - Bing Cui
- State Key Laboratory of Bioactive Substance and Function of Natural Medicines, Institute of Materia Medica, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing, China
- CAMS Key Laboratory of Molecular Mechanism and Target Discovery of Metabolic Disorder and Tumorigenesis, Beijing, China
| | - Pingping Li
- State Key Laboratory of Bioactive Substance and Function of Natural Medicines, Institute of Materia Medica, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing, China.
- Diabetes Research Center of Chinese Academy of Medical Sciences, Beijing, China.
- CAMS Key Laboratory of Molecular Mechanism and Target Discovery of Metabolic Disorder and Tumorigenesis, Beijing, China.
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Deng A, Wang Y, Huang K, Xie P, Mo P, Liu F, Chen J, Chen K, Wang Y, Xiao B. Artichoke (Cynara scolymus L.) water extract alleviates palmitate-induced insulin resistance in HepG2 hepatocytes via the activation of IRS1/PI3K/AKT/FoxO1 and GSK-3β signaling pathway. BMC Complement Med Ther 2023; 23:460. [PMID: 38102588 PMCID: PMC10722847 DOI: 10.1186/s12906-023-04275-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/27/2023] [Accepted: 11/23/2023] [Indexed: 12/17/2023] Open
Abstract
BACKGROUND Artichoke (Cynara scolymus L.) is a typical element of a traditional Mediterranean diet and has potential health advantages for insulin resistance (IR) and type 2 diabetes mellitus (T2DM). This study aims to evaluate the effect and underlying mechanism of artichoke water extract (AWE) on palmitate (PA)-induced IR in human hepatocellular carcinoma (HepG2) cells. METHODS The effect of AWE on cell viability was determined using CCK8 assay. Cellular glucose uptake, glucose consumption, glucose production, and glycogen content were assessed after AWE treatment. The gene expression and protein levels were examined by real-time polymerase chain reaction (qRT-PCR) and western blotting. RESULTS The results showed that AWE dose-dependently increased cell viability in IR HepG2 cells (P < 0.01). AWE treatment significantly promoted glucose uptake and consumption, decreased glucose production, and increased the cellular glycogen content in IR HepG2 cells (P < 0.01). Mechanistically, AWE elevated the phosphorylation and total protein levels of major insulin signaling molecules in IR HepG2 cells, which resulted in a decrease in the expression of phosphoenolpyruvate carboxykinase (PEPCK) and glucose-6-phosphatase (G6Pase) and the inhibition of glycogen synthase (GS) phosphorylation in IR HepG2 cells. Furthermore, the protective effect of AWE on IR HepG2 cells might be ascribed to the inhibition of the endoplasmic reticulum (ER) stress. CONCLUSION We conclude that AWE may improve glucose metabolism by regulating IRS1/PI3K/AKT/FoxO1 and GSK-3β signaling associated with the inhibition of ER stress in IR HepG2 cells induced by PA.
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Affiliation(s)
- Aihua Deng
- Key Laboratory of Agricultural Products Processing and Food Safety in Hunan Higher Education; Science and Technology Innovation Team for Efficient Agricultural Production and Deep Processing at General University in Hunan Province; Human Provincial Engineering Research Center for Fresh Wet Rice Noodels; College of Life and Environmental Science, Hunan University of Arts and Science, Changde, 415000, China
| | - Yun Wang
- Key Laboratory of Agricultural Products Processing and Food Safety in Hunan Higher Education; Science and Technology Innovation Team for Efficient Agricultural Production and Deep Processing at General University in Hunan Province; Human Provincial Engineering Research Center for Fresh Wet Rice Noodels; College of Life and Environmental Science, Hunan University of Arts and Science, Changde, 415000, China
| | - Kerui Huang
- Key Laboratory of Agricultural Products Processing and Food Safety in Hunan Higher Education; Science and Technology Innovation Team for Efficient Agricultural Production and Deep Processing at General University in Hunan Province; Human Provincial Engineering Research Center for Fresh Wet Rice Noodels; College of Life and Environmental Science, Hunan University of Arts and Science, Changde, 415000, China
| | - Peng Xie
- Key Laboratory of Agricultural Products Processing and Food Safety in Hunan Higher Education; Science and Technology Innovation Team for Efficient Agricultural Production and Deep Processing at General University in Hunan Province; Human Provincial Engineering Research Center for Fresh Wet Rice Noodels; College of Life and Environmental Science, Hunan University of Arts and Science, Changde, 415000, China
| | - Ping Mo
- Key Laboratory of Agricultural Products Processing and Food Safety in Hunan Higher Education; Science and Technology Innovation Team for Efficient Agricultural Production and Deep Processing at General University in Hunan Province; Human Provincial Engineering Research Center for Fresh Wet Rice Noodels; College of Life and Environmental Science, Hunan University of Arts and Science, Changde, 415000, China
| | - Fengying Liu
- Key Laboratory of Agricultural Products Processing and Food Safety in Hunan Higher Education; Science and Technology Innovation Team for Efficient Agricultural Production and Deep Processing at General University in Hunan Province; Human Provincial Engineering Research Center for Fresh Wet Rice Noodels; College of Life and Environmental Science, Hunan University of Arts and Science, Changde, 415000, China
| | - Jun Chen
- Sanjin Group Hunan Sanjin Pharmaceutical Co., Ltd, Changde, 415000, China
| | - Kaiyi Chen
- Sanjin Group Hunan Sanjin Pharmaceutical Co., Ltd, Changde, 415000, China
| | - Yun Wang
- National Clinical Research Center for Hematologic Diseases, Jiangsu Institute of Hematology, the First Affiliated Hospital of Soochow University, Soochow University, Suzhou, P. R. China.
| | - Bing Xiao
- Institute for Development and Regenerative Cardiovascular Medicine, Xinhua Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, 200092, China.
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Huang X, Zhu H, Lu W, Cao L, Fang Z, Che L, Lin Y, Xu S, Zhuo Y, Hua L, Jiang X, Sun M, Wu D, Feng B. Acute Endoplasmic Reticulum Stress Suppresses Hepatic Gluconeogenesis by Stimulating MAPK Phosphatase 3 Degradation. Int J Mol Sci 2023; 24:15561. [PMID: 37958545 PMCID: PMC10647389 DOI: 10.3390/ijms242115561] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/30/2023] [Revised: 10/10/2023] [Accepted: 10/23/2023] [Indexed: 11/15/2023] Open
Abstract
Drug-induced liver injury (DILI) is a widespread and harmful disease, and is closely linked to acute endoplasmic reticulum (ER) stress. Previous reports have shown that acute ER stress can suppress hepatic gluconeogenesis and even leads to hypoglycemia. However, the mechanism is still unclear. MAPK phosphatase 3 (MKP-3) is a positive regulator for gluconeogenesis. Thus, this study was conducted to investigate the role of MKP-3 in the suppression of gluconeogenesis by acute ER stress, as well as the regulatory role of acute ER stress on the expression of MKP-3. Results showed that acute ER stress induced by tunicamycin significantly suppressed gluconeogenesis in both hepatocytes and mouse liver, reduced glucose production level in hepatocytes, and decreased fasting blood glucose level in mice. Additionally, the protein level of MKP-3 was reduced by acute ER stress in both hepatocytes and mouse liver. Mkp-3 deficiency eliminated the inhibitory effect of acute ER stress on gluconeogenesis in hepatocytes. Moreover, the reduction effect of acute ER stress on blood glucose level and hepatic glucose 6-phosphatase (G6pc) expression was not observed in the liver-specific Mkp-3 knockout mice. Furthermore, activation of protein kinase R-like ER kinase (PERK) decreased the MKP-3 protein level, while inactivation of PERK abolished the reduction effect of acute ER stress on the MKP-3 protein level in hepatocytes. Taken together, our study suggested that acute ER stress could suppress hepatic gluconeogenesis by stimulating MKP-3 degradation via PERK, at least partially. Thus, MKP-3 might be a therapeutic target for DILI-related hypoglycemia.
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Affiliation(s)
- Xiaohua Huang
- Animal Nutrition Institute, Sichuan Agricultural University, Chengdu 611130, China; (X.H.); (H.Z.); (W.L.); (L.C.); (Z.F.); (L.C.); (Y.L.); (S.X.); (Y.Z.); (L.H.); (X.J.)
- Key Laboratory of Animal Disease-Resistant Nutrition of Ministry of Education, Sichuan Agricultural University, Chengdu 611130, China
| | - Heng Zhu
- Animal Nutrition Institute, Sichuan Agricultural University, Chengdu 611130, China; (X.H.); (H.Z.); (W.L.); (L.C.); (Z.F.); (L.C.); (Y.L.); (S.X.); (Y.Z.); (L.H.); (X.J.)
- Key Laboratory of Animal Disease-Resistant Nutrition of Ministry of Education, Sichuan Agricultural University, Chengdu 611130, China
| | - Wei Lu
- Animal Nutrition Institute, Sichuan Agricultural University, Chengdu 611130, China; (X.H.); (H.Z.); (W.L.); (L.C.); (Z.F.); (L.C.); (Y.L.); (S.X.); (Y.Z.); (L.H.); (X.J.)
| | - Lei Cao
- Animal Nutrition Institute, Sichuan Agricultural University, Chengdu 611130, China; (X.H.); (H.Z.); (W.L.); (L.C.); (Z.F.); (L.C.); (Y.L.); (S.X.); (Y.Z.); (L.H.); (X.J.)
| | - Zhengfeng Fang
- Animal Nutrition Institute, Sichuan Agricultural University, Chengdu 611130, China; (X.H.); (H.Z.); (W.L.); (L.C.); (Z.F.); (L.C.); (Y.L.); (S.X.); (Y.Z.); (L.H.); (X.J.)
| | - Lianqiang Che
- Animal Nutrition Institute, Sichuan Agricultural University, Chengdu 611130, China; (X.H.); (H.Z.); (W.L.); (L.C.); (Z.F.); (L.C.); (Y.L.); (S.X.); (Y.Z.); (L.H.); (X.J.)
| | - Yan Lin
- Animal Nutrition Institute, Sichuan Agricultural University, Chengdu 611130, China; (X.H.); (H.Z.); (W.L.); (L.C.); (Z.F.); (L.C.); (Y.L.); (S.X.); (Y.Z.); (L.H.); (X.J.)
| | - Shengyu Xu
- Animal Nutrition Institute, Sichuan Agricultural University, Chengdu 611130, China; (X.H.); (H.Z.); (W.L.); (L.C.); (Z.F.); (L.C.); (Y.L.); (S.X.); (Y.Z.); (L.H.); (X.J.)
| | - Yong Zhuo
- Animal Nutrition Institute, Sichuan Agricultural University, Chengdu 611130, China; (X.H.); (H.Z.); (W.L.); (L.C.); (Z.F.); (L.C.); (Y.L.); (S.X.); (Y.Z.); (L.H.); (X.J.)
| | - Lun Hua
- Animal Nutrition Institute, Sichuan Agricultural University, Chengdu 611130, China; (X.H.); (H.Z.); (W.L.); (L.C.); (Z.F.); (L.C.); (Y.L.); (S.X.); (Y.Z.); (L.H.); (X.J.)
| | - Xuemei Jiang
- Animal Nutrition Institute, Sichuan Agricultural University, Chengdu 611130, China; (X.H.); (H.Z.); (W.L.); (L.C.); (Z.F.); (L.C.); (Y.L.); (S.X.); (Y.Z.); (L.H.); (X.J.)
| | - Mengmeng Sun
- College of Science, Sichuan Agricultural University, Chengdu 611130, China;
| | - De Wu
- Animal Nutrition Institute, Sichuan Agricultural University, Chengdu 611130, China; (X.H.); (H.Z.); (W.L.); (L.C.); (Z.F.); (L.C.); (Y.L.); (S.X.); (Y.Z.); (L.H.); (X.J.)
- Key Laboratory of Animal Disease-Resistant Nutrition of Ministry of Education, Sichuan Agricultural University, Chengdu 611130, China
| | - Bin Feng
- Animal Nutrition Institute, Sichuan Agricultural University, Chengdu 611130, China; (X.H.); (H.Z.); (W.L.); (L.C.); (Z.F.); (L.C.); (Y.L.); (S.X.); (Y.Z.); (L.H.); (X.J.)
- Key Laboratory of Animal Disease-Resistant Nutrition of Ministry of Education, Sichuan Agricultural University, Chengdu 611130, China
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Tokarz VL, Pereira RVS, Jaldin-Fincati JR, Mylvaganam S, Klip A. Junctional integrity and directional mobility of lymphatic endothelial cell monolayers are disrupted by saturated fatty acids. Mol Biol Cell 2023; 34:ar28. [PMID: 36735487 PMCID: PMC10092641 DOI: 10.1091/mbc.e22-08-0367] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023] Open
Abstract
The lymphatic circulation regulates transfer of tissue fluid and immune cells toward the venous circulation. While obesity impairs lymphatic vessel function, the contribution of lymphatic endothelial cells (LEC) to metabolic disease phenotypes is poorly understood. LEC of lymphatic microvessels are in direct contact with the interstitial fluid, whose composition changes during the development of obesity, markedly by increases in saturated fatty acids. Palmitate, the most prevalent saturated fatty acid in lymph and blood, is detrimental to metabolism and function of diverse tissues, but its impact on LEC function is relatively unknown. Here, palmitate (but not its unsaturated counterpart palmitoleate) destabilized adherens junctions in human microvascular LEC in culture, visualized as changes in VE-cadherin, α-catenin, and β-catenin localization. Detachment of these proteins from cortical actin filaments was associated with abundant actomyosin stress fibers. The effects were Rho-associated protein kinase (ROCK)- and myosin-dependent, as inhibition with Y27632 or blebbistatin, respectively, prevented stress fiber accumulation and preserved junctions. Without functional junctions, palmitate-treated LEC failed to directionally migrate to close wounds in two dimensions and failed to form endothelial tubes in three dimensions. A reorganization of the lymphatic endothelial actin cytoskeleton may contribute to lymphatic dysfunction in obesity and could be considered as a therapeutic target.
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Affiliation(s)
- Victoria L Tokarz
- Cell Biology Program, The Hospital for Sick Children, Toronto, ON M5G 0A4, Canada.,Department of Physiology, University of Toronto, Toronto, ON M5S 1A1, Canada
| | - Rafaela V S Pereira
- Cell Biology Program, The Hospital for Sick Children, Toronto, ON M5G 0A4, Canada
| | | | - Sivakami Mylvaganam
- Cell Biology Program, The Hospital for Sick Children, Toronto, ON M5G 0A4, Canada.,Department of Biochemistry, University of Toronto, Toronto, ON M5S 1A1, Canada
| | - Amira Klip
- Cell Biology Program, The Hospital for Sick Children, Toronto, ON M5G 0A4, Canada.,Department of Physiology, University of Toronto, Toronto, ON M5S 1A1, Canada.,Department of Biochemistry, University of Toronto, Toronto, ON M5S 1A1, Canada.,Department of Paediatrics, University of Toronto, Toronto, ON M5S 1A1, Canada
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Yudhani RD, Sari Y, Nugrahaningsih DAA, Sholikhah EN, Rochmanti M, Purba AKR, Khotimah H, Nugrahenny D, Mustofa M. In Vitro Insulin Resistance Model: A Recent Update. J Obes 2023; 2023:1964732. [PMID: 36714242 PMCID: PMC9876677 DOI: 10.1155/2023/1964732] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/10/2022] [Revised: 12/28/2022] [Accepted: 01/07/2023] [Indexed: 01/20/2023] Open
Abstract
Insulin resistance, which affects insulin-sensitive tissues, including adipose tissues, skeletal muscle, and the liver, is the central pathophysiological mechanism underlying type 2 diabetes progression. Decreased glucose uptake in insulin-sensitive tissues disrupts insulin signaling pathways, particularly the PI3K/Akt pathway. An in vitro model is appropriate for studying the cellular and molecular mechanisms underlying insulin resistance because it is easy to maintain and the results can be easily reproduced. The application of cell-based models for exploring the pathogenesis of diabetes and insulin resistance as well as for developing drugs for these conditions is well known. However, a comprehensive review of in vitro insulin resistance models is lacking. Therefore, this review was conducted to provide a comprehensive overview and summary of the latest in vitro insulin resistance models, particularly 3T3-L1 (preadipocyte), C2C12 (skeletal muscle), and HepG2 (liver) cell lines induced with palmitic acid, high glucose, or chronic exposure to insulin.
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Affiliation(s)
- Ratih D. Yudhani
- Department of Pharmacology, Faculty of Medicine, Universitas Sebelas Maret, Jl. Ir. Sutami No. 36A, Surakarta, Central Java 57126, Indonesia
| | - Yulia Sari
- Department of Parasitology, Faculty of Medicine, Universitas Sebelas Maret, Jl. Ir. Sutami No. 36A, Surakarta, Central Java 57126, Indonesia
| | - Dwi A. A. Nugrahaningsih
- Department of Pharmacology and Therapy, Faculty of Medicine, Public Health and Nursing, Universitas Gadjah Mada, Jl. Farmako, Sekip Utara, Sleman, Daerah Istimewa Yogyakarta 55281, Indonesia
| | - Eti N. Sholikhah
- Department of Pharmacology and Therapy, Faculty of Medicine, Public Health and Nursing, Universitas Gadjah Mada, Jl. Farmako, Sekip Utara, Sleman, Daerah Istimewa Yogyakarta 55281, Indonesia
| | - Maftuchah Rochmanti
- Department of Anatomy, Histology and Pharmacology, Faculty of Medicine, Universitas Airlangga, Jl Mayjen Prof. Dr. Moestopo 47, Surabaya, East Java 60131, Indonesia
| | - Abdul K. R. Purba
- Department of Anatomy, Histology and Pharmacology, Faculty of Medicine, Universitas Airlangga, Jl Mayjen Prof. Dr. Moestopo 47, Surabaya, East Java 60131, Indonesia
| | - Husnul Khotimah
- Department of Pharmacology, Faculty of Medicine, Universitas Brawijaya, Jl. Veteran, Malang, East Java 65145, Indonesia
| | - Dian Nugrahenny
- Department of Pharmacology, Faculty of Medicine, Universitas Brawijaya, Jl. Veteran, Malang, East Java 65145, Indonesia
| | - Mustofa Mustofa
- Department of Pharmacology and Therapy, Faculty of Medicine, Public Health and Nursing, Universitas Gadjah Mada, Jl. Farmako, Sekip Utara, Sleman, Daerah Istimewa Yogyakarta 55281, Indonesia
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8
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Jäntti MH, Jackson SN, Kuhn J, Parkkinen I, Sree S, Hinkle JJ, Jokitalo E, Deterding LJ, Harvey BK. Palmitate and thapsigargin have contrasting effects on ER membrane lipid composition and ER proteostasis in neuronal cells. Biochim Biophys Acta Mol Cell Biol Lipids 2022; 1867:159219. [PMID: 35981704 PMCID: PMC9452468 DOI: 10.1016/j.bbalip.2022.159219] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/06/2022] [Revised: 07/21/2022] [Accepted: 08/10/2022] [Indexed: 11/25/2022]
Abstract
The endoplasmic reticulum (ER) is an organelle that performs several key functions such as protein synthesis and folding, lipid metabolism and calcium homeostasis. When these functions are disrupted, such as upon protein misfolding, ER stress occurs. ER stress can trigger adaptive responses to restore proper functioning such as activation of the unfolded protein response (UPR). In certain cells, the free fatty acid palmitate has been shown to induce the UPR. Here, we examined the effects of palmitate on UPR gene expression in a human neuronal cell line and compared it with thapsigargin, a known depletor of ER calcium and trigger of the UPR. We used a Gaussia luciferase-based reporter to assess how palmitate treatment affects ER proteostasis and calcium homeostasis in the cells. We also investigated how ER calcium depletion by thapsigargin affects lipid membrane composition by performing mass spectrometry on subcellular fractions and compared this to palmitate. Surprisingly, palmitate treatment did not activate UPR despite prominent changes to membrane phospholipids. Conversely, thapsigargin induced a strong UPR, but did not significantly change the membrane lipid composition in subcellular fractions. In summary, our data demonstrate that changes in membrane lipid composition and disturbances in ER calcium homeostasis have a minimal influence on each other in neuronal cells. These data provide new insight into the adaptive interplay of lipid homeostasis and proteostasis in the cell.
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Affiliation(s)
- Maria H Jäntti
- Molecular Mechanisms of Cellular Stress and Inflammation, Intramural Research Program, National Institute on Drug Abuse, Baltimore, MD 21224, USA.
| | - Shelley N Jackson
- Translational Analytical Core, Intramural Research Program, National Institute on Drug Abuse, Baltimore, MD 21224, USA
| | - Jeffrey Kuhn
- Mass Spectrometry Research and Support Group, National Institute of Environmental Health Sciences, Research Triangle Park, Durham, NC 27709, USA
| | - Ilmari Parkkinen
- Neuroscience Center, Helsinki Institute for Life Science, University of Helsinki, Haartmaninkatu 8, 00014 Helsinki, Finland
| | - Sreesha Sree
- Cell and Tissue Dynamics Research Programme, Institute of Biotechnology, Helsinki Institute of Life Science, University of Helsinki, Finland
| | - Joshua J Hinkle
- Molecular Mechanisms of Cellular Stress and Inflammation, Intramural Research Program, National Institute on Drug Abuse, Baltimore, MD 21224, USA
| | - Eija Jokitalo
- Cell and Tissue Dynamics Research Programme, Institute of Biotechnology, Helsinki Institute of Life Science, University of Helsinki, Finland
| | - Leesa J Deterding
- Mass Spectrometry Research and Support Group, National Institute of Environmental Health Sciences, Research Triangle Park, Durham, NC 27709, USA
| | - Brandon K Harvey
- Molecular Mechanisms of Cellular Stress and Inflammation, Intramural Research Program, National Institute on Drug Abuse, Baltimore, MD 21224, USA.
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9
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You J, Zhao M, Chen S, Jiang L, Gao S, Yin H, Zhao L. Effect of chitooligosaccharides with a specific degree of polymerization on multiple targets in T2DM mice. BIORESOUR BIOPROCESS 2022; 9:94. [PMID: 38647883 PMCID: PMC10992422 DOI: 10.1186/s40643-022-00579-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/24/2022] [Accepted: 08/11/2022] [Indexed: 11/10/2022] Open
Abstract
Chitooligosaccharides (COS) are found naturally in the ocean and present a variety of physiological activities, of which hypoglycemic action has attracted considerable research attention. This study aimed to assess the therapeutic effect of COS on mice suffering from type 2 diabetes mellitus (T2DM). COS effectively reduced blood glucose and blood lipid levels and improved glucose tolerance. Furthermore, COS revealed strong inhibitory activity against α-glucosidase, reducing postprandial blood glucose levels. Molecular docking data showed that COS might interact with surrounding amino acids to form a complex and decrease α-glucosidase activity. Additionally, COS enhanced insulin signal transduction and glycogen synthesis while restricting gluconeogenesis in the liver and muscles, reducing insulin resistance (IR) as a result. Moreover, COS effectively protected and restored islet cell function to increase insulin secretion. These results indicated that COS exhibited a significant hypoglycemic effect with multi-target participation. Therefore, COS may serve as a new preventive or therapeutic drug for diabetes to alleviate metabolic syndrome.
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Affiliation(s)
- Jiangshan You
- State Key Laboratory of Bioreactor Engineering, School of Biotechnology, East China University of Science and Technology, Shanghai, 200237, China
| | - Mengyao Zhao
- State Key Laboratory of Bioreactor Engineering, School of Biotechnology, East China University of Science and Technology, Shanghai, 200237, China
- Shanghai Collaborative Innovation Center for Biomanufacturing Technology (SCICBT), Shanghai, 200237, China
| | - Shumin Chen
- State Key Laboratory of Bioreactor Engineering, School of Biotechnology, East China University of Science and Technology, Shanghai, 200237, China
| | - Lihua Jiang
- State Key Laboratory of Bioreactor Engineering, School of Biotechnology, East China University of Science and Technology, Shanghai, 200237, China
- Shanghai Collaborative Innovation Center for Biomanufacturing Technology (SCICBT), Shanghai, 200237, China
| | - Shuhong Gao
- State Key Laboratory of Bioreactor Engineering, School of Biotechnology, East China University of Science and Technology, Shanghai, 200237, China
| | - Hao Yin
- Organ Transplant Center, Shanghai Changzheng Hospital, Shanghai, 200003, China.
| | - Liming Zhao
- State Key Laboratory of Bioreactor Engineering, School of Biotechnology, East China University of Science and Technology, Shanghai, 200237, China.
- Shanghai Collaborative Innovation Center for Biomanufacturing Technology (SCICBT), Shanghai, 200237, China.
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10
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Mubarak SA, Otaibi AA, Qarni AA, Bakillah A, Iqbal J. Reduction in Insulin Mediated ERK Phosphorylation by Palmitate in Liver Cells Is Independent of Fatty Acid Induced ER Stress. Nutrients 2022; 14:nu14173641. [PMID: 36079898 PMCID: PMC9460427 DOI: 10.3390/nu14173641] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/20/2022] [Revised: 07/12/2022] [Accepted: 07/12/2022] [Indexed: 12/04/2022] Open
Abstract
Saturated free fatty acids (FFAs) such as palmitate in the circulation are known to cause endoplasmic reticulum (ER) stress and insulin resistance in peripheral tissues. In addition to protein kinase B (AKT) signaling, extracellular signal-regulated kinase (ERK) has been implicated in the development of insulin resistance. However, there are conflicting data regarding role of ERK signaling in ER stress-induced insulin resistance. In this study, we investigated the effects of ER stress on insulin resistance and ERK phosphorylation in Huh-7 cells and evaluated how oleate prevents palmitate-mediated ER stress. Treatment with insulin resulted in an increase of 38–45% in the uptake of glucose in control cells compared to non-insulin-treated control cells, along with an increase in the phosphorylation of AKT and ERK. We found that treatment with palmitate increased the expression of ER stress genes, including the splicing of X box binding protein 1 (XBP1) mRNA. At the same time, we observed a decrease in insulin-mediated uptake of glucose and ERK phosphorylation in Huh-7 cells, without any change in AKT phosphorylation. Supplementation of oleate along with palmitate mitigated the palmitate-induced ER stress but did not affect insulin-mediated glucose uptake or ERK phosphorylation. The findings of this study suggest that palmitate reduces insulin-mediated ERK phosphorylation in liver cells and this effect is independent of fatty-acid-induced ER stress.
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11
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Zhou D, Zhang J, Xiao C, Mo C, Ding BS. Trimethylamine-N-oxide (TMAO) mediates the crosstalk between the gut microbiota and hepatic vascular niche to alleviate liver fibrosis in nonalcoholic steatohepatitis. Front Immunol 2022; 13:964477. [PMID: 36072588 PMCID: PMC9441952 DOI: 10.3389/fimmu.2022.964477] [Citation(s) in RCA: 11] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/08/2022] [Accepted: 08/04/2022] [Indexed: 11/13/2022] Open
Abstract
Liver fibrosis is one main histological characteristic of nonalcoholic steatohepatitis (NASH), a disease paralleling a worldwide surge in metabolic syndromes with no approved therapies. The role of the gut microbiota in NASH pathogenesis has not been thoroughly illustrated, especially how the gut microbiota derives metabolites to influence the distal liver in NASH. Here, we performed 16S rDNA amplicon sequencing analysis of feces from a mouse NASH model induced by a Western diet and CCl4 injury and found genera under Streptococcaceae, Alcaligenaceae, Oscillibacter, and Pseudochrobactrum, which are related metabolites of TMAO. Injection of the gut microbial metabolite TMAO reduced the progression of liver fibrosis in the mouse NASH model. Further analysis revealed that the anti-fibrotic TMAO normalized gut microbiota diversity and preserved liver sinusoidal endothelial cell integrity by inhibiting endothelial beta 1-subunit of Na (+), K (+)-ATPase (ATP1B1) expression. Collectively, our findings suggest TMAO-mediated crosstalk between microbiota metabolites and hepatic vasculature, and perturbation of this crosstalk disrupts sinusoidal vasculature to promote liver fibrosis in NASH.
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Affiliation(s)
- Dengcheng Zhou
- Key Laboratory of Birth Defects and Related Diseases of Women and Children of MOE, State Key Laboratory of Biotherapy, West China Second University Hospital, Sichuan University, Chengdu, China
| | - Jing Zhang
- Key Laboratory of Birth Defects and Related Diseases of Women and Children of MOE, State Key Laboratory of Biotherapy, West China Second University Hospital, Sichuan University, Chengdu, China
| | - Chengju Xiao
- Key Laboratory of Birth Defects and Related Diseases of Women and Children of MOE, State Key Laboratory of Biotherapy, West China Second University Hospital, Sichuan University, Chengdu, China
| | - Chunheng Mo
- Key Laboratory of Birth Defects and Related Diseases of Women and Children of MOE, State Key Laboratory of Biotherapy, West China Second University Hospital, Sichuan University, Chengdu, China
- *Correspondence: Bi-Sen Ding, ; Chunheng Mo,
| | - Bi-Sen Ding
- Key Laboratory of Birth Defects and Related Diseases of Women and Children of MOE, State Key Laboratory of Biotherapy, West China Second University Hospital, Sichuan University, Chengdu, China
- Fibrosis Research Program, Division of Pulmonary and Critical Care Medicine, Division of Liver Diseases, Icahn School of Medicine at Mount Sinai, New York, NY, United States
- Division of Regenerative Medicine, Weill Cornell Medicine, New York, NY, United States
- *Correspondence: Bi-Sen Ding, ; Chunheng Mo,
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12
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SIRT2 Deficiency Exacerbates Hepatic Steatosis via a Putative Role of the ER Stress Pathway. Int J Mol Sci 2022; 23:ijms23126790. [PMID: 35743232 PMCID: PMC9223775 DOI: 10.3390/ijms23126790] [Citation(s) in RCA: 9] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/15/2022] [Revised: 06/15/2022] [Accepted: 06/16/2022] [Indexed: 11/24/2022] Open
Abstract
Nonalcoholic fatty liver disease (NAFLD), a condition strongly associated with obesity and insulin resistance, is characterized by hepatic lipid accumulation and activation of the endoplasmic reticulum (ER) stress response. The sirtuin 2 (SIRT2) protein deacetylase is emerging as a new player in metabolic homeostasis, but its role in the development of hepatic steatosis and its link with ER stress activation remains unknown. SIRT2-knockout (SIRT2-KO) and wild-type mice were fed either a control or a high-fat diet (HFD) for 4 weeks. Genetic manipulation of SIRT2 levels was performed in human hepatic cells. Although apparently normal under a control diet, SIRT2-KO mice showed accelerated body weight gain and adiposity on a HFD, accompanied by severe insulin resistance. Importantly, SIRT2-KO mice exhibited worsened hepatic steatosis independently from diet, consistent with upregulated gene expression of lipogenic enzymes and increased expression of ER stress markers. Exposure of hepatic cells to palmitate induced lipid accumulation, increased ER stress, and decreased SIRT2 expression. Moreover, SIRT2-silenced cells showed enhanced lipid accumulation and ER stress activation under basal conditions, whereas SIRT2 overexpression abrogated palmitate-induced lipid deposition and ER stress activation. Our findings reveal a role for SIRT2 in the regulation of hepatic lipid homeostasis, potentially through the ER stress response, suggesting that SIRT2 activation might constitute a therapeutic strategy against obesity and its metabolic complications.
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13
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Liebmann M, Asuaje Pfeifer M, Grupe K, Scherneck S. Estradiol (E2) Improves Glucose-Stimulated Insulin Secretion and Stabilizes GDM Progression in a Prediabetic Mouse Model. Int J Mol Sci 2022; 23:ijms23126693. [PMID: 35743136 PMCID: PMC9223537 DOI: 10.3390/ijms23126693] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/20/2022] [Revised: 06/11/2022] [Accepted: 06/14/2022] [Indexed: 01/27/2023] Open
Abstract
Female New Zealand obese (NZO) mice are an established model of preconceptional (pc.) prediabetes that progresses as gestational diabetes mellitus (GDM) during gestation. It is known that NZO mice show improvement in insulin sensitivity and glucose-stimulated insulin secretion (GSIS) during gestation in vivo. The latter is no longer detectable in ex vivo perifusion experiments in isolated islets of Langerhans, suggesting a modulation by extrapancreatic factors. Here, we demonstrated that plasma 17β-estradiol (E2) levels increased markedly in NZO mice during gestation. The aim of this work was to determine whether these increased E2 levels are responsible for the improvement in metabolism during gestation. To achieve this goal, we examined its effects in isolated islets and primary hepatocytes of both NZO and metabolically healthy NMRI mice. E2 increased GSIS in the islets of both strains significantly. Hepatic glucose production (HGP) failed to be decreased by insulin in NZO hepatocytes but was reduced by E2 in both strains. Hepatocytes of pregnant NZO mice showed significantly lower glucose uptake (HGU) compared with NMRI controls, whereby E2 stimulation diminished this difference. Hepatocytes of pregnant NZO showed reduced glycogen content, increased cyclic adenosine monophosphate (cAMP) levels, and reduced AKT activation. These differences were abolished after E2 stimulation. In conclusion, our data indicate that E2 stabilizes and prevents deterioration of the metabolic state of the prediabetic NZO mice. E2 particularly increases GSIS and improves hepatic glucose utilization to a lower extent.
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14
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Mohi-ud-din R, Mir RH, Wani TU, Alsharif KF, Alam W, Albrakati A, Saso L, Khan H. The Regulation of Endoplasmic Reticulum Stress in Cancer: Special Focuses on Luteolin Patents. Molecules 2022; 27:molecules27082471. [PMID: 35458669 PMCID: PMC9031790 DOI: 10.3390/molecules27082471] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/27/2022] [Revised: 03/17/2022] [Accepted: 03/21/2022] [Indexed: 12/24/2022] Open
Abstract
Cancer is a major health problem across the globe, and is expeditiously growing at a faster rate worldwide. The endoplasmic reticulum (ER) is a membranous cell organelle having inextricable links in cellular homeostasis. Altering ER homeostasis initiates various signaling events known as the unfolded protein response (UPR). The basic purpose of the UPR is to reinstate the homeostasis; however, a continuous UPR can stimulate pathways of cell death, such as apoptosis. As a result, there is great perturbation to target particular signaling pathways of ER stress. Flavonoids have gained significant interest as a potential anticancer agent because of their considerable role in causing cytotoxicity of the cancerous cells. Luteolin, a flavonoid isolated from natural products, is a promising phytochemical used in the treatment of cancer. The current study is designed to review the different endoplasmic reticulum stress pathways involved in the cancer, mechanistic insights of luteolin as an anticancer agent in modulating ER stress, and the available luteolin patent formulations were also highlighted. The patents were selected on the basis of pre-clinical and/or clinical trials, and established antitumor effects using patent databases of FPO IP and Espacenet. The patented formulation of luteolin studied so far has shown promising anticancer potential against different cancer cell lines. However, further research is still required to determine the molecular targets of such bioactive molecules so that they can be used as anticancer drugs.
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Affiliation(s)
- Roohi Mohi-ud-din
- Pharmacognosy & Phytochemistry Division, Department of Pharmaceutical Sciences, University of Kashmir, Hazratbal, Srinagar 190006, India
- Correspondence: (R.M.-u.-d.); (H.K.)
| | - Reyaz Hassan Mir
- Pharmaceutical Chemistry Division, Department of Pharmaceutical Sciences, University of Kashmir, Hazratbal, Srinagar 190006, India;
| | - Taha Umair Wani
- Pharmaceutics Division, Department of Pharmaceutical Sciences, University of Kashmir, Hazratbal, Srinagar 190006, India;
| | - Khalaf F. Alsharif
- Department of Clinical Laboratory, College of Applied Medical Science, Taif University, P.O. Box 11099, Taif 21944, Saudi Arabia;
| | - Waqas Alam
- Department of Pharmacy, Abdul Wali Khan University, Mardan 23200, Pakistan;
| | - Ashraf Albrakati
- Department of Human Anatomy, College of Medicine, Taif University, P.O. Box 11099, Taif 21944, Saudi Arabia;
| | - Luciano Saso
- Department of Physiology and Pharmacology, Sapienza University, 00158 Rome, Italy;
| | - Haroon Khan
- Department of Pharmacy, Abdul Wali Khan University, Mardan 23200, Pakistan;
- Correspondence: (R.M.-u.-d.); (H.K.)
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15
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Lee DH, Park JS, Lee YS, Bae SH. PERK prevents hepatic lipotoxicity by activating the p62-ULK1 axis-mediated noncanonical KEAP1-Nrf2 pathway. Redox Biol 2022; 50:102235. [PMID: 35091323 PMCID: PMC8801383 DOI: 10.1016/j.redox.2022.102235] [Citation(s) in RCA: 15] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/16/2021] [Revised: 12/16/2021] [Accepted: 01/12/2022] [Indexed: 02/07/2023] Open
Abstract
Hepatic lipotoxicity is a crucial factor in nonalcoholic steatohepatitis resulting from excessive saturated fatty acid-induced reactive oxygen species (ROS)-mediated cell death, which is associated with the accumulation of endoplasmic reticulum (ER) stress in the liver. The unfolded protein response (UPR) alleviates ER stress by restoring ER protein folding homeostasis. However, whether UPR contributes ROS elimination under lipotoxicity remains unclear. The Kelch like ECH-associated protein 1 (KEAP1)-nuclear factor, erythroid 2 like 2 (Nrf2) pathway provides antioxidant defense against lipotoxic stress by eliminating ROS and can be activated by the p62-Unc-51 like autophagy activating kinase 1 (ULK1) axis. However, the upstream molecular regulator of the p62-ULK1 axis-induced KEAP1-Nrf2 pathway in the same context remains unidentified. Here, we demonstrated that PKR-like ER kinase (PERK), a UPR sensor, directly phosphorylates p62 and ULK1, thereby activating the noncanonical KEAP1-Nrf2 pathway. We also elucidated the molecular mechanism underlying the PERK-mediated p62-ULK1 axis-dependent noncanonical KEAP1-Nrf2 pathway, which could represent a promising therapeutic strategy against hepatic lipotoxicity. Hepatic lipotoxicity is a crucial factor in the progression of NASH, associated with the increased ER stress. PERK, one of UPR sensors, activates noncanonical KEAP1-Nrf2 pathway by phosphorylating p62 at S351. PERK also phosphorylates ULK1 at S317, which mediates autophagic KEAP1 degradation and Nrf2 activation. PERK protects mouse liver against lipotoxicity via Nrf2 activation.
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16
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Gut Metabolite Trimethylamine N-Oxide Protects INS-1 β-Cell and Rat Islet Function under Diabetic Glucolipotoxic Conditions. Biomolecules 2021; 11:biom11121892. [PMID: 34944536 PMCID: PMC8699500 DOI: 10.3390/biom11121892] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/02/2021] [Revised: 12/11/2021] [Accepted: 12/14/2021] [Indexed: 12/14/2022] Open
Abstract
Serum accumulation of the gut microbial metabolite trimethylamine N-oxide (TMAO) is associated with high caloric intake and type 2 diabetes (T2D). Impaired pancreatic β-cell function is a hallmark of diet-induced T2D, which is linked to hyperglycemia and hyperlipidemia. While TMAO production via the gut microbiome-liver axis is well defined, its molecular effects on metabolic tissues are unclear, since studies in various tissues show deleterious and beneficial TMAO effects. We investigated the molecular effects of TMAO on functional β-cell mass. We hypothesized that TMAO may damage functional β-cell mass by inhibiting β-cell viability, survival, proliferation, or function to promote T2D pathogenesis. We treated INS-1 832/13 β-cells and primary rat islets with physiological TMAO concentrations and compared functional β-cell mass under healthy standard cell culture (SCC) and T2D-like glucolipotoxic (GLT) conditions. GLT significantly impeded β-cell mass and function by inducing oxidative and endoplasmic reticulum (ER) stress. TMAO normalized GLT-mediated damage in β-cells and primary islet function. Acute 40µM TMAO recovered insulin production, insulin granule formation, and insulin secretion by upregulating the IRE1α unfolded protein response to GLT-induced ER and oxidative stress. These novel results demonstrate that TMAO protects β-cell function and suggest that TMAO may play a beneficial molecular role in diet-induced T2D conditions.
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17
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Gut microbiota dependent trimethylamine N-oxide aggravates angiotensin II-induced hypertension. Redox Biol 2021; 46:102115. [PMID: 34474396 PMCID: PMC8408632 DOI: 10.1016/j.redox.2021.102115] [Citation(s) in RCA: 75] [Impact Index Per Article: 25.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/13/2021] [Revised: 08/20/2021] [Accepted: 08/20/2021] [Indexed: 12/12/2022] Open
Abstract
Gut microbiota produce Trimethylamine N-oxide (TMAO) by metabolizing dietary phosphatidylcholine, choline, l-carnitine and betaine. TMAO is implicated in the pathogenesis of chronic kidney disease (CKD), diabetes, obesity and atherosclerosis. We test, whether TMAO augments angiotensin II (Ang II)-induced vasoconstriction and hence promotes Ang II-induced hypertension. Plasma TMAO levels were indeed elevated in hypertensive patients, thus the potential pathways by which TMAO mediates these effects were explored. Ang II (400 ng/kg−1min−1) was chronically infused for 14 days via osmotic minipumps in C57Bl/6 mice. TMAO (1%) or antibiotics were given via drinking water. Vasoconstriction of renal afferent arterioles and mesenteric arteries were assessed by microperfusion and wire myograph, respectively. In Ang II-induced hypertensive mice, TMAO elevated systolic blood pressure and caused vasoconstriction, which was alleviated by antibiotics. TMAO enhanced the Ang II-induced acute pressor responses (12.2 ± 1.9 versus 20.6 ± 1.4 mmHg; P < 0.05) and vasoconstriction (32.3 ± 2.6 versus 55.9 ± 7.0%, P < 0.001). Ang II-induced intracellular Ca2+ release in afferent arterioles (147 ± 7 versus 234 ± 26%; P < 0.001) and mouse vascular smooth muscle cells (VSMC, 123 ± 3 versus 157 ± 9%; P < 0.001) increased by TMAO treatment. Preincubation of VSMC with TMAO activated the PERK/ROS/CaMKII/PLCβ3 pathway. Pharmacological inhibition of PERK, ROS, CaMKII and PLCβ3 impaired the effect of TMAO on Ca2+ release. Thus, TMAO facilitates Ang II-induced vasoconstriction, thereby promoting Ang II-induced hypertension, which involves the PERK/ROS/CaMKII/PLCβ3 axis. Orally administered TMAO aggravates Ang II-induced hypertension. Antibiotics alleviate Ang II-induced hypertension by reducing TMAO generation. High concentrations of TMAO constrict afferent arterioles and mesenteric arteries and increase blood pressure. Low concentrations of TMAO enhance Ang II-induced vasoconstriction and acute pressor response via activating PERK/ROS/CaMKII/PLCβ3/Ca2+ pathway.
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18
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Krueger ES, Lloyd TS, Tessem JS. The Accumulation and Molecular Effects of Trimethylamine N-Oxide on Metabolic Tissues: It's Not All Bad. Nutrients 2021; 13:nu13082873. [PMID: 34445033 PMCID: PMC8400152 DOI: 10.3390/nu13082873] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/23/2021] [Revised: 08/15/2021] [Accepted: 08/19/2021] [Indexed: 02/07/2023] Open
Abstract
Since elevated serum levels of trimethylamine N-oxide (TMAO) were first associated with increased risk of cardiovascular disease (CVD), TMAO research among chronic diseases has grown exponentially. We now know that serum TMAO accumulation begins with dietary choline metabolism across the microbiome-liver-kidney axis, which is typically dysregulated during pathogenesis. While CVD research links TMAO to atherosclerotic mechanisms in vascular tissue, its molecular effects on metabolic tissues are unclear. Here we report the current standing of TMAO research in metabolic disease contexts across relevant tissues including the liver, kidney, brain, adipose, and muscle. Since poor blood glucose management is a hallmark of metabolic diseases, we also explore the variable TMAO effects on insulin resistance and insulin production. Among metabolic tissues, hepatic TMAO research is the most common, whereas its effects on other tissues including the insulin producing pancreatic β-cells are largely unexplored. Studies on diseases including obesity, diabetes, liver diseases, chronic kidney disease, and cognitive diseases reveal that TMAO effects are unique under pathologic conditions compared to healthy controls. We conclude that molecular TMAO effects are highly context-dependent and call for further research to clarify the deleterious and beneficial molecular effects observed in metabolic disease research.
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Affiliation(s)
- Emily S. Krueger
- Department of Nutrition, Dietetics and Food Science, Brigham Young University, Provo, UT 84602, USA; (E.S.K.); (T.S.L.)
| | - Trevor S. Lloyd
- Department of Nutrition, Dietetics and Food Science, Brigham Young University, Provo, UT 84602, USA; (E.S.K.); (T.S.L.)
- Medical Education Program, David Geffen School of Medicine at UCLA, Los Angeles, CA 90095, USA
| | - Jeffery S. Tessem
- Department of Nutrition, Dietetics and Food Science, Brigham Young University, Provo, UT 84602, USA; (E.S.K.); (T.S.L.)
- Correspondence: ; Tel.: +1-801-422-9082
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19
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Tashiro E, Nagasawa Y, Itoh S, Imoto M. Involvement of miR-3180-3p and miR-4632-5p in palmitic acid-induced insulin resistance. Mol Cell Endocrinol 2021; 534:111371. [PMID: 34157350 DOI: 10.1016/j.mce.2021.111371] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/15/2021] [Revised: 05/25/2021] [Accepted: 06/17/2021] [Indexed: 01/17/2023]
Abstract
Insulin resistance is defined as a failure to trigger the activation of the PI3K-AKT pathway by normal levels of insulin; therefore, it is well linked to metabolic disorders. Although multiple mechanisms contribute to insulin resistance, one major cause is elevated concentrations of plasma free fatty acids, which are known to suppress insulin signaling. However, the underlying mechanism is still elusive. Here, we found that palmitic acid increased the expression of two miRNAs, miR-3180-3p and miR-4632-5p, in HepG2 cells. Transfection of HepG2 cells with miR-3180-3p or miR-4632-5p reduced insulin-induced activation of the PI3K-AKT pathway. Moreover, palmitic acid or two miRNAs inhibited insulin-induced phosphorylation of Tyr612 on IRS-1 without affecting insulin receptor activation. Therefore, two miRNAs are suggested to be involved in palmitic acid-induced insulin resistance through suppression of insulin-induced IRS-1 phosphorylation. Identification of miR-3180-3p and miR-4632-5p targets could provide valuable information for the development of therapeutic drugs for type 2 diabetes.
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Affiliation(s)
- Etsu Tashiro
- Department of Biosciences and Informatics, Faculty of Science and Technology, Keio University, Yokohama, Japan; Laboratory of Biochemistry, Showa Pharmaceutical University, Tokyo, Japan.
| | - Yumi Nagasawa
- Department of Biosciences and Informatics, Faculty of Science and Technology, Keio University, Yokohama, Japan
| | - Susumu Itoh
- Laboratory of Biochemistry, Showa Pharmaceutical University, Tokyo, Japan
| | - Masaya Imoto
- Department of Biosciences and Informatics, Faculty of Science and Technology, Keio University, Yokohama, Japan; Department of Neurology, Juntendo University School of Medicine, Tokyo, Japan
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20
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Griffiths A, Wang J, Song Q, Iyamu ID, Liu L, Park J, Jiang Y, Huang R, Song Z. Nicotinamide N-methyltransferase (NNMT) upregulation via the mTORC1-ATF4 pathway activation contributes to palmitate-induced lipotoxicity in hepatocytes. Am J Physiol Cell Physiol 2021; 321:C585-C595. [PMID: 34378991 DOI: 10.1152/ajpcell.00195.2021] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Defined as the dysfunction and/or cell death caused by toxic lipids accumulation in hepatocytes, hepatic lipotoxicity plays a pathological role in non-alcoholic fatty liver disease. The cellular and molecular mechanisms underlying lipotoxicity remain to be elucidated. In this study, using AML12 cells, a non-transformed murine hepatocyte cell line, exposed to palmitate (a 16-C saturated fatty acid) as an experimental model, we investigated the role and mechanisms of nicotinamide N-methyltransferase (NNMT), a methyltransferase catalyzing nicotinamide methylation and degradation, in hepatic lipotoxicity. We initially identified activating transcription factor 4 (ATF4) as a major transcription factor for hepatic NNMT expression. Here, we demonstrated that palmitate upregulates NNMT expression via activating ATF4 in a mechanistic target of rapamycin complex 1 (mTORC1)-dependent mechanism in that mTORC1 inhibition by both Torin1 and rapamycin attenuated ATF4 activation and NNMT upregulation. We further demonstrated that the mTORC1-dependent ATF4 activation is an integral signaling event of unfolded protein response (UPR) as both ATF4 activation and NNMT upregulation by tunicamycin, a well-documented endoplasmic reticulum (ER) stress inducer, are blunted when hepatocytes were pretreated with Torin1. Importantly, our data uncovered that NNMT upregulation contributes to palmitate-induced hepatotoxicity as NNMT inhibition, via either pharmacological (NNMT inhibitors) or genetic approach (siRNA transfection), provided protection against palmitate lipotoxicity. Our further mechanistic exploration identified protein kinase A (PKA) activation to contribute, at least, partially to the protective effect of NNMT inhibition against lipotoxicity. Collectively, our data demonstrated that NNMT upregulation by the mTORC1-ATF4 pathway activation contributes to the development of lipotoxicity in hepatocytes.
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Affiliation(s)
- Alexandra Griffiths
- Department of Kinesiology and Nutrition, University of Illinois at Chicago, Chicago, IL, United States
| | - Jun Wang
- Department of Kinesiology and Nutrition, University of Illinois at Chicago, Chicago, IL, United States.,Department of Gastroenterology, Tongji Medical College and The Central Hospital of Wuhan, Huazhong University of Science and Technology, Wuhan, China
| | - Qing Song
- Department of Kinesiology and Nutrition, University of Illinois at Chicago, Chicago, IL, United States
| | - Iredia D Iyamu
- Department of Medicinal Chemistry and Molecular Pharmacology, Purdue University, West Lafayette, IN, United States
| | - Lifeng Liu
- Department of Physiology and Biophysics, University of Illinois at Chicago, Chicago, IL, United States
| | - Jooman Park
- Department of Physiology and Biophysics, University of Illinois at Chicago, Chicago, IL, United States
| | - Yuwei Jiang
- Department of Physiology and Biophysics, University of Illinois at Chicago, Chicago, IL, United States
| | - Rong Huang
- Department of Medicinal Chemistry and Molecular Pharmacology, Purdue University, West Lafayette, IN, United States
| | - Zhenyuan Song
- Department of Kinesiology and Nutrition, University of Illinois at Chicago, Chicago, IL, United States
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21
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Thibaut R, Gage MC, Pineda-Torra I, Chabrier G, Venteclef N, Alzaid F. Liver macrophages and inflammation in physiology and physiopathology of non-alcoholic fatty liver disease. FEBS J 2021; 289:3024-3057. [PMID: 33860630 PMCID: PMC9290065 DOI: 10.1111/febs.15877] [Citation(s) in RCA: 31] [Impact Index Per Article: 10.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/24/2021] [Revised: 03/05/2021] [Accepted: 04/12/2021] [Indexed: 12/13/2022]
Abstract
Non‐alcoholic fatty liver disease (NAFLD) is the hepatic manifestation of metabolic syndrome, being a common comorbidity of type 2 diabetes and with important links to inflammation and insulin resistance. NAFLD represents a spectrum of liver conditions ranging from steatosis in the form of ectopic lipid storage, to inflammation and fibrosis in nonalcoholic steatohepatitis (NASH). Macrophages that populate the liver play important roles in maintaining liver homeostasis under normal physiology and in promoting inflammation and mediating fibrosis in the progression of NAFLD toward to NASH. Liver macrophages are a heterogenous group of innate immune cells, originating from the yolk sac or from circulating monocytes, that are required to maintain immune tolerance while being exposed portal and pancreatic blood flow rich in nutrients and hormones. Yet, liver macrophages retain a limited capacity to raise the alarm in response to danger signals. We now know that macrophages in the liver play both inflammatory and noninflammatory roles throughout the progression of NAFLD. Macrophage responses are mediated first at the level of cell surface receptors that integrate environmental stimuli, signals are transduced through multiple levels of regulation in the cell, and specific transcriptional programmes dictate effector functions. These effector functions play paramount roles in determining the course of disease in NAFLD and even more so in the progression towards NASH. The current review covers recent reports in the physiological and pathophysiological roles of liver macrophages in NAFLD. We emphasise the responses of liver macrophages to insulin resistance and the transcriptional machinery that dictates liver macrophage function.
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Affiliation(s)
- Ronan Thibaut
- Cordeliers Research Centre, INSERM, IMMEDIAB Laboratory, Sorbonne Université, Université de Paris, France
| | - Matthew C Gage
- Department of Comparative Biomedical Sciences, Royal Veterinary College, London, UK
| | - Inès Pineda-Torra
- Department of Medicine, Centre for Cardiometabolic and Vascular Science, University College London, UK
| | - Gwladys Chabrier
- Department of Comparative Biomedical Sciences, Royal Veterinary College, London, UK
| | - Nicolas Venteclef
- Cordeliers Research Centre, INSERM, IMMEDIAB Laboratory, Sorbonne Université, Université de Paris, France
| | - Fawaz Alzaid
- Cordeliers Research Centre, INSERM, IMMEDIAB Laboratory, Sorbonne Université, Université de Paris, France
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22
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How does hepatic lipid accumulation lead to lipotoxicity in non-alcoholic fatty liver disease? Hepatol Int 2021; 15:21-35. [PMID: 33548031 PMCID: PMC7886759 DOI: 10.1007/s12072-020-10121-2] [Citation(s) in RCA: 143] [Impact Index Per Article: 47.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/03/2020] [Accepted: 12/10/2020] [Indexed: 02/06/2023]
Abstract
BACKGROUND Non-alcoholic fatty liver disease (NAFLD), characterized as excess lipid accumulation in the liver which is not due to alcohol use, has emerged as one of the major health problems around the world. The dysregulated lipid metabolism creates a lipotoxic environment which promotes the development of NAFLD, especially the progression from simple steatosis (NAFL) to non-alcoholic steatohepatitis (NASH). PURPOSEAND AIM This review focuses on the mechanisms of lipid accumulation in the liver, with an emphasis on the metabolic fate of free fatty acids (FFAs) in NAFLD and presents an update on the relevant cellular processes/mechanisms that are involved in lipotoxicity. The changes in the levels of various lipid species that result from the imbalance between lipolysis/lipid uptake/lipogenesis and lipid oxidation/secretion can cause organellar dysfunction, e.g. ER stress, mitochondrial dysfunction, lysosomal dysfunction, JNK activation, secretion of extracellular vesicles (EVs) and aggravate (or be exacerbated by) hypoxia which ultimately lead to cell death. The aim of this review is to provide an overview of how abnormal lipid metabolism leads to lipotoxicity and the cellular mechanisms of lipotoxicity in the context of NAFLD.
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23
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Significance of Simple Steatosis: An Update on the Clinical and Molecular Evidence. Cells 2020; 9:cells9112458. [PMID: 33187255 PMCID: PMC7698018 DOI: 10.3390/cells9112458] [Citation(s) in RCA: 29] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/06/2020] [Revised: 10/28/2020] [Accepted: 11/07/2020] [Indexed: 12/13/2022] Open
Abstract
Non-alcoholic fatty liver disease (NAFLD) is defined clinicopathologically by the accumulation of lipids in >5% of hepatocytes and the exclusion of secondary causes of fat accumulation. NAFLD encompasses a wide spectrum of liver damage, extending from simple steatosis or non-alcoholic fatty liver (NAFL) to non-alcoholic steatohepatitis (NASH)—the latter is characterized by inflammation and hepatocyte ballooning degeneration, in addition to the steatosis, with or without fibrosis. NAFLD is now the most common cause of chronic liver disease in Western countries and affects around one quarter of the general population. It is a multisystem disorder, which is associated with an increased risk of type 2 diabetes mellitus as well as liver- and cardiovascular-related mortality. Although earlier studies had suggested that NAFL is benign (i.e., non-progressive), cumulative evidence challenges this dogma, and recent data suggest that nearly 25% of those with NAFL may develop fibrosis. Importantly, NAFLD patients are more susceptible to the toxic effects of alcohol, drugs, and other insults to the liver. This is likely due to the functional impairment of steatotic hepatocytes, which is virtually undetectable by current clinical tests. This review provides an overview of the current evidence on the clinical significance of NAFL and discusses the molecular basis for NAFL development and progression.
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24
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Nath A, Oak A, Chen KY, Li I, Splichal RC, Portis J, Foster S, Walton SP, Chan C. Palmitate-Induced IRE1-XBP1-ZEB Signaling Represses Desmoplakin Expression and Promotes Cancer Cell Migration. Mol Cancer Res 2020; 19:240-248. [PMID: 33106375 DOI: 10.1158/1541-7786.mcr-19-0480] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/10/2019] [Revised: 04/23/2020] [Accepted: 10/21/2020] [Indexed: 11/16/2022]
Abstract
Elevated uptake of saturated fatty acid palmitate is associated with metastatic progression of cancer cells; however, the precise signaling mechanism behind the phenomenon is unclear. The loss of cell adhesion proteins, such as desmoplakin (DSP), is a key driving event in the transformation of cancer cells to more aggressive phenotypes. Here, we investigated the mechanism by which palmitate induces the loss of DSP in liver and breast cancer cells. We propose that palmitate activates the IRE1-XBP1 branch of the endoplasmic reticulum (ER) stress pathway to upregulate the ZEB transcription factor, leading to transcriptional repression of DSP. Using liver and breast cancer cells treated with palmitate, we found loss of DSP leads to increased cell migration independent of E-cadherin. We report that the ZEB family of transcription factors function as direct transcriptional repressors of DSP. CRISPR-mediated knockdown of IRE1 confirmed that the transcription of ZEB, loss of DSP, and enhanced migration in the presence of palmitate is dependent on the IRE1-XBP1 pathway. In addition, by analyzing the somatic expression and copy number variation profiles of over 11,000 tumor samples, we corroborate our hypothesis and establish the clinical relevance of DSP loss via ZEB in human cancers. IMPLICATIONS: Provides mechanistic link on palmitate-induced activation of IRE1α to cancer cell migration.
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Affiliation(s)
- Aritro Nath
- Genetics Program, Michigan State University, East Lansing, Michigan
| | - Amrita Oak
- Department of Chemical Engineering and Materials Science, Michigan State University, East Lansing, Michigan
| | - Kevin Y Chen
- Department of Chemical Engineering and Materials Science, Michigan State University, East Lansing, Michigan
| | - Irene Li
- Department of Chemical Engineering and Materials Science, Michigan State University, East Lansing, Michigan
| | - R Chauncey Splichal
- Department of Chemical Engineering and Materials Science, Michigan State University, East Lansing, Michigan
| | - Jason Portis
- Department of Chemical Engineering and Materials Science, Michigan State University, East Lansing, Michigan
| | - Sean Foster
- Department of Chemical Engineering and Materials Science, Michigan State University, East Lansing, Michigan
| | - S Patrick Walton
- Department of Chemical Engineering and Materials Science, Michigan State University, East Lansing, Michigan
| | - Christina Chan
- Genetics Program, Michigan State University, East Lansing, Michigan. .,Department of Chemical Engineering and Materials Science, Michigan State University, East Lansing, Michigan.,Department of Biochemistry and Molecular Biology, Michigan State University, East Lansing, Michigan
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25
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Vandebrouck C, Ferreira T. Glued in lipids: Lipointoxication in cystic fibrosis. EBioMedicine 2020; 61:103038. [PMID: 33038767 PMCID: PMC7648119 DOI: 10.1016/j.ebiom.2020.103038] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/23/2020] [Revised: 07/27/2020] [Accepted: 09/14/2020] [Indexed: 01/14/2023] Open
Abstract
Cystic Fibrosis (CF) is an autosomal recessive disease caused by mutations in the CF transmembrane regulator (CFTR) gene, which encodes a chloride channel located at the apical surface of epithelial cells. Unsaturated Fatty Acid (UFA) deficiency has been a persistent observation in tissues from patients with CF. However, the impacts of such deficiencies on the etiology of the disease have been the object of intense debates. The aim of the present review is first to highlight the general consensus on fatty acid dysregulations that emerges from, sometimes apparently contradictory, studies. In a second step, a unifying mechanism for the potential impacts of these fatty acid dysregulations in CF cells, based on alterations of membrane biophysical properties (known as lipointoxication), is proposed. Finally, the contribution of lipointoxication to the progression of the CF disease and how it could affect the efficacy of current treatments is also discussed.
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Affiliation(s)
- Clarisse Vandebrouck
- Laboratoire "Lipointoxication and Channelopathies (LiTch) - ConicMeds", Université de Poitiers, 1, rue Georges Bonnet, Poitiers, France; Laboratoire "Signalisation et Transports Ioniques Membranaires (STIM; EA 7349)", Université de Poitiers, 1, rue Georges Bonnet, Poitiers, France
| | - Thierry Ferreira
- Laboratoire "Lipointoxication and Channelopathies (LiTch) - ConicMeds", Université de Poitiers, 1, rue Georges Bonnet, Poitiers, France.
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26
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Prolonged Lipid Accumulation in Cultured Primary Human Hepatocytes Rather Leads to ER Stress than Oxidative Stress. Int J Mol Sci 2020; 21:ijms21197097. [PMID: 32993055 PMCID: PMC7582586 DOI: 10.3390/ijms21197097] [Citation(s) in RCA: 16] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/11/2020] [Revised: 09/18/2020] [Accepted: 09/23/2020] [Indexed: 12/12/2022] Open
Abstract
Overweight has become a major health care problem in Western societies and is accompanied by an increasing incidence and prevalence of non-alcoholic fatty liver disease (NAFLD). The progression from NAFLD to non-alcoholic steatohepatitis (NASH) marks a crucial tipping point in the progression of severe and irreversible liver diseases. This study aims to gain further insight into the molecular processes leading to the evolution from steatosis to steatohepatitis. Steatosis was induced in cultures of primary human hepatocytes by continuous five-day exposure to free fatty acids (FFAs). The kinetics of lipid accumulation, lipotoxicity, and oxidative stress were measured. Additionally, ER stress was evaluated by analyzing the protein expression profiles of its key players: PERK, IRE1a, and ATF6a. Our data revealed that hepatocytes are capable of storing enormous amounts of lipids without showing signs of lipotoxicity. Prolonged lipid accumulation did not create an imbalance in hepatocyte redox homeostasis or a reduction in antioxidative capacity. However, we observed an FFA-dependent increase in ER stress, revealing thresholds for triggering the activation of pathways associated with lipid stress, inhibition of protein translation, and apoptosis. Our study clearly showed that even severe lipid accumulation can be attenuated by cellular defenses, but regenerative capacities may be reduced.
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27
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Galmés-Pascual BM, Martínez-Cignoni MR, Morán-Costoya A, Bauza-Thorbrügge M, Sbert-Roig M, Valle A, Proenza AM, Lladó I, Gianotti M. 17β-estradiol ameliorates lipotoxicity-induced hepatic mitochondrial oxidative stress and insulin resistance. Free Radic Biol Med 2020; 150:148-160. [PMID: 32105829 DOI: 10.1016/j.freeradbiomed.2020.02.016] [Citation(s) in RCA: 25] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/13/2019] [Revised: 02/11/2020] [Accepted: 02/19/2020] [Indexed: 02/08/2023]
Abstract
The prevalence and severity of nonalcoholic fatty liver disease (NAFLD) is higher in men and postmenopausal women compared to premenopausal women, suggesting a protective role for ovarian hormones. Diet-induced obesity and fatty acids surplus promote mitochondrial dysfunction in liver, triggering oxidative stress and activation of c-Jun N-terminal kinase (JNK) which has been related to the development of insulin resistance and steatosis, the main hallmarks of NAFLD. Considering that estrogen, in particular 17β-estradiol (E2), have been reported to improve mitochondrial biogenesis and function in liver, our aim was to elucidate the role of E2 in preventing fatty acid-induced insulin resistance in hepatocytes through modulation of mitochondrial function, oxidative stress and JNK activation. An in vivo study was conducted in Wistar rats of both sexes (n = 7) fed control diet and high-fat diet (HFD), and in vitro studies were carried out in HepG2 cells treated with palmitate (PA) and E2 for 24 h. Our HFD-fed male rats showed a prediabetic state characterized by greater systemic and hepatic insulin resistance, as well as higher lipid content in liver, compared to females. JNK activation rose markedly in males in response to HFD feeding, in parallel with mitochondrial dysfunction and oxidative stress. Consistently, in PA-exposed HepG2 cells, E2 treatment prevented JNK activation, insulin resistance and fatty acid accumulation. Altogether, our data highlights the importance of E2 as a mitigating factor of fatty acid-insulin resistance in hepatocytes through downregulation of JNK activation, by means of mitochondrial function improvement.
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Affiliation(s)
- Bel M Galmés-Pascual
- Grup Metabolisme Energètic i Nutrició, Departament de Biologia Fonamental i Ciències de la Salut, Institut Universitari d'Investigació en Ciències de la Salut (IUNICS), Universitat de les Illes Balears, Ctra. Valldemossa, km 7.5, E-07122, Palma de Mallorca, Illes Balears, Spain; Institut d'Investigació Sanitària Illes Balears (IdISBa), Hospital Universitari Son Espases, E-07120, Palma de Mallorca, Illes Balears, Spain
| | - Melanie Raquel Martínez-Cignoni
- Grup Metabolisme Energètic i Nutrició, Departament de Biologia Fonamental i Ciències de la Salut, Institut Universitari d'Investigació en Ciències de la Salut (IUNICS), Universitat de les Illes Balears, Ctra. Valldemossa, km 7.5, E-07122, Palma de Mallorca, Illes Balears, Spain; Institut d'Investigació Sanitària Illes Balears (IdISBa), Hospital Universitari Son Espases, E-07120, Palma de Mallorca, Illes Balears, Spain
| | - Andrea Morán-Costoya
- Grup Metabolisme Energètic i Nutrició, Departament de Biologia Fonamental i Ciències de la Salut, Institut Universitari d'Investigació en Ciències de la Salut (IUNICS), Universitat de les Illes Balears, Ctra. Valldemossa, km 7.5, E-07122, Palma de Mallorca, Illes Balears, Spain
| | - Marco Bauza-Thorbrügge
- Grup Metabolisme Energètic i Nutrició, Departament de Biologia Fonamental i Ciències de la Salut, Institut Universitari d'Investigació en Ciències de la Salut (IUNICS), Universitat de les Illes Balears, Ctra. Valldemossa, km 7.5, E-07122, Palma de Mallorca, Illes Balears, Spain; Institut d'Investigació Sanitària Illes Balears (IdISBa), Hospital Universitari Son Espases, E-07120, Palma de Mallorca, Illes Balears, Spain
| | - Miquel Sbert-Roig
- Grup Metabolisme Energètic i Nutrició, Departament de Biologia Fonamental i Ciències de la Salut, Institut Universitari d'Investigació en Ciències de la Salut (IUNICS), Universitat de les Illes Balears, Ctra. Valldemossa, km 7.5, E-07122, Palma de Mallorca, Illes Balears, Spain; Institut d'Investigació Sanitària Illes Balears (IdISBa), Hospital Universitari Son Espases, E-07120, Palma de Mallorca, Illes Balears, Spain
| | - Adamo Valle
- Grup Metabolisme Energètic i Nutrició, Departament de Biologia Fonamental i Ciències de la Salut, Institut Universitari d'Investigació en Ciències de la Salut (IUNICS), Universitat de les Illes Balears, Ctra. Valldemossa, km 7.5, E-07122, Palma de Mallorca, Illes Balears, Spain; Institut d'Investigació Sanitària Illes Balears (IdISBa), Hospital Universitari Son Espases, E-07120, Palma de Mallorca, Illes Balears, Spain; Centro de Investigación Biomédica en Red Fisiopatología de la Obesidad y Nutrición (CIBERobn, CB06/03/0043), Instituto de Salud Carlos III, E- 28029, Madrid, Spain.
| | - Ana M Proenza
- Grup Metabolisme Energètic i Nutrició, Departament de Biologia Fonamental i Ciències de la Salut, Institut Universitari d'Investigació en Ciències de la Salut (IUNICS), Universitat de les Illes Balears, Ctra. Valldemossa, km 7.5, E-07122, Palma de Mallorca, Illes Balears, Spain; Institut d'Investigació Sanitària Illes Balears (IdISBa), Hospital Universitari Son Espases, E-07120, Palma de Mallorca, Illes Balears, Spain; Centro de Investigación Biomédica en Red Fisiopatología de la Obesidad y Nutrición (CIBERobn, CB06/03/0043), Instituto de Salud Carlos III, E- 28029, Madrid, Spain
| | - Isabel Lladó
- Grup Metabolisme Energètic i Nutrició, Departament de Biologia Fonamental i Ciències de la Salut, Institut Universitari d'Investigació en Ciències de la Salut (IUNICS), Universitat de les Illes Balears, Ctra. Valldemossa, km 7.5, E-07122, Palma de Mallorca, Illes Balears, Spain; Institut d'Investigació Sanitària Illes Balears (IdISBa), Hospital Universitari Son Espases, E-07120, Palma de Mallorca, Illes Balears, Spain; Centro de Investigación Biomédica en Red Fisiopatología de la Obesidad y Nutrición (CIBERobn, CB06/03/0043), Instituto de Salud Carlos III, E- 28029, Madrid, Spain
| | - Magdalena Gianotti
- Grup Metabolisme Energètic i Nutrició, Departament de Biologia Fonamental i Ciències de la Salut, Institut Universitari d'Investigació en Ciències de la Salut (IUNICS), Universitat de les Illes Balears, Ctra. Valldemossa, km 7.5, E-07122, Palma de Mallorca, Illes Balears, Spain; Institut d'Investigació Sanitària Illes Balears (IdISBa), Hospital Universitari Son Espases, E-07120, Palma de Mallorca, Illes Balears, Spain; Centro de Investigación Biomédica en Red Fisiopatología de la Obesidad y Nutrición (CIBERobn, CB06/03/0043), Instituto de Salud Carlos III, E- 28029, Madrid, Spain
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28
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Mitochondrial dysfunction: An emerging link in the pathophysiology of polycystic ovary syndrome. Mitochondrion 2020; 52:24-39. [PMID: 32081727 DOI: 10.1016/j.mito.2020.02.006] [Citation(s) in RCA: 26] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/23/2019] [Revised: 12/31/2019] [Accepted: 02/12/2020] [Indexed: 12/19/2022]
Abstract
Polycystic ovary syndrome (PCOS) is a common endocrine disorder characterized by irregular menstrual cycles, hyperandrogenism and subfertility. Due to its complex manifestation, the pathogenic mechanism of PCOS is not well defined. Cumulative effect of altered genetic and epigenetic factors along with environmental factors may play a role in the manifestation of PCOS leading to systemic malfunction. With failure of genome-wide association study (GWAS) and other studies performed on nuclear genome to provide any clue for precise mechanism of PCOS pathogenesis, attention has been diverted to mitochondria. Mitochondrion plays an important role in cellular metabolic functions and is linked to Insulin Resistance (IR). Recently, increasing reports suggest that mitochondrial dysfunction may be a contributing factor in the pathogenesis of PCOS. Hence, in this review, we have discussed mitochondrial biology in brief and emphasizes on genetic and epigenetic aspects of mitochondrial dysfunction studied in PCOS women and PCOS-like animal models. We also highlight underlying mechanism behind mitochondrial dysfunction contributing to PCOS and its related complications such as obesity, diabetes, cardiovascular diseases, metabolic syndrome, non-alcoholic fatty liver disease (NAFLD) and cancer. Furthermore, contrasting remarks against involvement of mitochondrial dysfunction in PCOS pathophysiology have also been presented. This review enhances our understanding in relation to mitochondrial dysfunction in the etiology of PCOS and stimulates further research to explore a clear link between mitochondrial dysfunction and PCOS pathogenesis and progression. Understanding pathogenic mechanisms underlying PCOS will open new windows to develop promising therapeutic strategies against PCOS.
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29
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Regulation of Molecular Chaperone GRP78 by Hepatitis B Virus: Control of Viral Replication and Cell Survival. Mol Cell Biol 2020; 40:MCB.00475-19. [PMID: 31712392 DOI: 10.1128/mcb.00475-19] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/08/2019] [Accepted: 11/01/2019] [Indexed: 12/11/2022] Open
Abstract
Chronic hepatitis B (CHB) remains a global health problem, carrying a high risk for progression into cirrhosis and liver failure. Molecular chaperones are involved in diverse pathophysiological processes including viral infection. However, the role of molecular chaperones in hepatitis B virus (HBV) infection and its underlying mechanisms remain unclear. Here, we identified GRP78 as one of the molecular chaperones most strongly induced by HBV in human hepatocytes. Gain- and loss-of-function analyses demonstrated that GRP78 exerted an inhibitory effect on HBV transcription and replication. Further study showed that GRP78 was involved in the activation of AKT/mTOR signaling in hepatocytes, which contributed to GRP78-mediated inhibition of HBV. Of note, HBV-upregulated GRP78 was found to play a crucial role in maintaining the survival of hepatocytes via facilitating a mild endoplasmic reticulum (ER) stress. Together, our findings suggest that HBV may sacrifice part of its replication for establishing a persistent infection through induction of GRP78, a master ER stress regulator. Targeting GRP78 may help develop to design novel therapeutic strategies against chronic HBV infection and the associated hepatocellular carcinoma.
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30
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Trimethylamine N-Oxide Binds and Activates PERK to Promote Metabolic Dysfunction. Cell Metab 2019; 30:1141-1151.e5. [PMID: 31543404 DOI: 10.1016/j.cmet.2019.08.021] [Citation(s) in RCA: 202] [Impact Index Per Article: 40.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/06/2019] [Revised: 07/02/2019] [Accepted: 08/26/2019] [Indexed: 12/20/2022]
Abstract
The gut-microbe-derived metabolite trimethylamine N-oxide (TMAO) is increased by insulin resistance and associated with several sequelae of metabolic syndrome in humans, including cardiovascular, renal, and neurodegenerative disease. The mechanism by which TMAO promotes disease is unclear. We now reveal the endoplasmic reticulum stress kinase PERK (EIF2AK3) as a receptor for TMAO: TMAO binds to PERK at physiologically relevant concentrations; selectively activates the PERK branch of the unfolded protein response; and induces the transcription factor FoxO1, a key driver of metabolic disease, in a PERK-dependent manner. Furthermore, interventions to reduce TMAO, either by manipulation of the gut microbiota or by inhibition of the TMAO synthesizing enzyme, flavin-containing monooxygenase 3, can reduce PERK activation and FoxO1 levels in the liver. Taken together, these data suggest TMAO and PERK may be central to the pathogenesis of the metabolic syndrome.
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31
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Saxton SN, Clark BJ, Withers SB, Eringa EC, Heagerty AM. Mechanistic Links Between Obesity, Diabetes, and Blood Pressure: Role of Perivascular Adipose Tissue. Physiol Rev 2019; 99:1701-1763. [PMID: 31339053 DOI: 10.1152/physrev.00034.2018] [Citation(s) in RCA: 136] [Impact Index Per Article: 27.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022] Open
Abstract
Obesity is increasingly prevalent and is associated with substantial cardiovascular risk. Adipose tissue distribution and morphology play a key role in determining the degree of adverse effects, and a key factor in the disease process appears to be the inflammatory cell population in adipose tissue. Healthy adipose tissue secretes a number of vasoactive adipokines and anti-inflammatory cytokines, and changes to this secretory profile will contribute to pathogenesis in obesity. In this review, we discuss the links between adipokine dysregulation and the development of hypertension and diabetes and explore the potential for manipulating adipose tissue morphology and its immune cell population to improve cardiovascular health in obesity.
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Affiliation(s)
- Sophie N Saxton
- Division of Cardiovascular Sciences, University of Manchester, Manchester, United Kingdom; School of Environment and Life Sciences, University of Salford, Salford, United Kingdom; and Department of Physiology, VU University Medical Centre, Amsterdam, Netherlands
| | - Ben J Clark
- Division of Cardiovascular Sciences, University of Manchester, Manchester, United Kingdom; School of Environment and Life Sciences, University of Salford, Salford, United Kingdom; and Department of Physiology, VU University Medical Centre, Amsterdam, Netherlands
| | - Sarah B Withers
- Division of Cardiovascular Sciences, University of Manchester, Manchester, United Kingdom; School of Environment and Life Sciences, University of Salford, Salford, United Kingdom; and Department of Physiology, VU University Medical Centre, Amsterdam, Netherlands
| | - Etto C Eringa
- Division of Cardiovascular Sciences, University of Manchester, Manchester, United Kingdom; School of Environment and Life Sciences, University of Salford, Salford, United Kingdom; and Department of Physiology, VU University Medical Centre, Amsterdam, Netherlands
| | - Anthony M Heagerty
- Division of Cardiovascular Sciences, University of Manchester, Manchester, United Kingdom; School of Environment and Life Sciences, University of Salford, Salford, United Kingdom; and Department of Physiology, VU University Medical Centre, Amsterdam, Netherlands
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Nischalke HD, Lutz P, Bartok E, Krämer B, Langhans B, Frizler R, Berg T, Hampe J, Buch S, Datz C, Stickel F, Hartmann G, Strassburg CP, Nattermann J, Spengler U. The PNPLA3 I148M variant promotes lipid-induced hepatocyte secretion of CXC chemokines establishing a tumorigenic milieu. J Mol Med (Berl) 2019; 97:1589-1600. [PMID: 31637480 DOI: 10.1007/s00109-019-01836-3] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/14/2019] [Revised: 09/05/2019] [Accepted: 09/20/2019] [Indexed: 02/07/2023]
Abstract
The I148M variant of the Patatin-like phospholipase domain-containing 3 (PNPLA3) protein is associated with an increased risk for liver inflammation and hepatocellular carcinoma (HCC), but the underlying mechanism is unknown. We hypothesized that enhanced CXC chemokine secretion mediates hepatic inflammation that accelerates development of HCC. Expandable primary human (upcyte®) hepatocytes and human PLC/PRF/5 hepatoma cells were lentivirally transduced with both PNPLA3 I148M variants and stimulated with lipids. Cytokine levels in culture supernatant and patient sera (n = 80) were analyzed by ELISA. Supernatants were assessed in transmigration experiments, tube formation, and proliferation assays. In vitro, lipid stimulation of transduced hepatocytes dose-dependently induced the production of interleukin-8 and CXCL1 in hepatocytes carrying the PNPLA3 148M variant. In line, sera from PNPLA3 148M-positive patients with alcoholic liver cirrhosis contained higher levels of interleukin-8 and CXCL1 than patients with wild-type PNPLA3. Supernatants from lipid-stimulated hepatocytes with the PNPLA3 148M variant induced enhanced migration of white blood cells, angiogenesis, and cell proliferation in comparison with supernatants from wild-type hepatocytes via CXC receptors 1 and 2. Increased production of interleukin-8 and CXCL1 by hepatocytes carrying the PNPLA3 148M variant contributes to a pro-inflammatory and tumorigenic milieu in patients with alcoholic liver disease. KEY MESSAGES: The PNPLA3 148M variant is associated with cirrhosis and hepatocellular carcinoma. Lipid stimulation of hepatocytes with this variant induces IL-8 and CXCL1. Supernatants from hepatocytes with this variant promote migration and angiogenesis. Sera from patients with this variant contained enhanced levels of IL-8 and CXCL1. The PNPLA3 148M variant contributes to a tumorigenic milieu via IL-8 and CXCL1.
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Affiliation(s)
- Hans Dieter Nischalke
- Department of Internal Medicine I, University Hospital, University of Bonn, Venusberg-Campus 1, 53127, Bonn, Germany.
| | - Philipp Lutz
- Department of Internal Medicine I, University Hospital, University of Bonn, Venusberg-Campus 1, 53127, Bonn, Germany
| | - Eva Bartok
- Institute of Clinical Chemistry and Clinical Pharmacology, University Hospital, University of Bonn, Bonn, Germany
| | - Benjamin Krämer
- Department of Internal Medicine I, University Hospital, University of Bonn, Venusberg-Campus 1, 53127, Bonn, Germany
| | - Bettina Langhans
- Department of Internal Medicine I, University Hospital, University of Bonn, Venusberg-Campus 1, 53127, Bonn, Germany
| | - Regina Frizler
- Department of Internal Medicine I, University Hospital, University of Bonn, Venusberg-Campus 1, 53127, Bonn, Germany
| | - Thomas Berg
- Department of Gastroenterology, University Hospital Leipzig, Leipzig, Germany
| | - Jochen Hampe
- Medical Department 1, University Hospital Dresden, TU Dresden, Dresden, Germany
| | - Stephan Buch
- Medical Department 1, University Hospital Dresden, TU Dresden, Dresden, Germany
| | - Christian Datz
- Department of Internal Medicine, Hospital Oberndorf, Teaching Hospital of the Paracelsus Private University of Salzburg, Salzburg, Austria
| | - Felix Stickel
- Department of Gastroenterology and Hepatology, University Hospital of Zürich, Zürich, Switzerland
| | - Gunther Hartmann
- Institute of Clinical Chemistry and Clinical Pharmacology, University Hospital, University of Bonn, Bonn, Germany
| | - Christian P Strassburg
- Department of Internal Medicine I, University Hospital, University of Bonn, Venusberg-Campus 1, 53127, Bonn, Germany
| | - Jacob Nattermann
- Department of Internal Medicine I, University Hospital, University of Bonn, Venusberg-Campus 1, 53127, Bonn, Germany
| | - Ulrich Spengler
- Department of Internal Medicine I, University Hospital, University of Bonn, Venusberg-Campus 1, 53127, Bonn, Germany
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Bang IH, Kwon OK, Hao L, Park D, Chung MJ, Oh BC, Lee S, Bae EJ, Park BH. Deacetylation of XBP1s by sirtuin 6 confers resistance to ER stress-induced hepatic steatosis. Exp Mol Med 2019; 51:1-11. [PMID: 31541078 PMCID: PMC6802632 DOI: 10.1038/s12276-019-0309-0] [Citation(s) in RCA: 35] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/21/2019] [Revised: 05/29/2019] [Accepted: 06/07/2019] [Indexed: 12/13/2022] Open
Abstract
The active spliced form of X-box-binding protein 1 (XBP1s) is a key modulator of ER stress, but the functional role of its post-translational modification remains unclear. Here, we demonstrate that XBP1s is a deacetylation target of Sirt6 and that its deacetylation protects against ER stress-induced hepatic steatosis. Specifically, the abundance of acetylated XBP1s and concordant hepatic steatosis were increased in hepatocyte-specific Sirt6 knockout and obese mice but were decreased by genetic overexpression and pharmacological activation of Sirt6. Mechanistically, we identified that Sirt6 deacetylated a transactivation domain of XBP1s at Lys257 and Lys297 and promoted XBP1s protein degradation through the ubiquitin-proteasome system. Overexpression of XBP1s, but not its deacetylation mutant 2KR (K257/297R), in mice increased lipid accumulation in the liver. Importantly, in liver tissues obtained from patients with nonalcoholic fatty liver disease (NAFLD), the extent of XBP1s acetylation correlated positively with the NAFLD activity score but negatively with the Sirt6 level. Collectively, we present direct evidence supporting the importance of XBP1 acetylation in ER stress-induced hepatic steatosis. Activating a protein that regulates cellular health could protect against fat accumulation during the onset of non-alcoholic fatty liver disease (NAFLD). A high-fat diet disrupts the endoplasmic reticulum (ER), a cellular membrane network responsible for synthesizing and processing proteins and fats, and can lead to NAFLD development. Previous studies found that a protein called XBP1s activates fat-related genes during NAFLD. Byung-Hyun Park and Eun Ju Bae at Chonbuk National University in Jeonbuk, South Korea, and co-workers, recently demonstrated that high levels of a regulatory protein called Sirt6 limits liver inflammation and ER stress during high-fat diets. Now, in experiments on mouse models and human liver cells, Park’s team have shown that Sirt6 reduces liver ER stress by modifying XBP1s. Encouraging Sirt6 activation may help protect against NAFLD progression.
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Affiliation(s)
- In Hyuk Bang
- Department of Biochemistry, Chonbuk National University Medical School, Jeonju, Jeonbuk, 54896, Republic of Korea
| | - Oh Kwang Kwon
- College of Pharmacy, Kyungpook National University, Daegu, 41566, Republic of Korea
| | - Lihua Hao
- Department of Biochemistry, Chonbuk National University Medical School, Jeonju, Jeonbuk, 54896, Republic of Korea
| | - Dami Park
- Department of Biochemistry, Chonbuk National University Medical School, Jeonju, Jeonbuk, 54896, Republic of Korea
| | - Myung-Ja Chung
- Department of Pathology, Chonbuk National University Medical School, Jeonju, Jeonbuk, 54896, Republic of Korea
| | - Byung-Chul Oh
- Department of Physiology, Gachon University College of Medicine, Incheon, 21999, Republic of Korea
| | - Sangkyu Lee
- College of Pharmacy, Kyungpook National University, Daegu, 41566, Republic of Korea
| | - Eun Ju Bae
- College of Pharmacy, Chonbuk National University, Jeonju, Jeonbuk, 54896, Republic of Korea.
| | - Byung-Hyun Park
- Department of Biochemistry, Chonbuk National University Medical School, Jeonju, Jeonbuk, 54896, Republic of Korea.
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Mohan S, R PRM, Brown L, Ayyappan P, G RK. Endoplasmic reticulum stress: A master regulator of metabolic syndrome. Eur J Pharmacol 2019; 860:172553. [PMID: 31325433 DOI: 10.1016/j.ejphar.2019.172553] [Citation(s) in RCA: 44] [Impact Index Per Article: 8.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/08/2019] [Revised: 07/04/2019] [Accepted: 07/16/2019] [Indexed: 12/20/2022]
Abstract
Endoplasmic reticulum (ER) stress, a change in the ER homeostasis, leads to initiation of the unfolded protein response (UPR). The primary functions of the UPR are to restore the ER's physiological activity and coordinate the apoptotic and adaptive responses. Pathophysiological conditions that augment ER stress include hypoxia, misfolded and/or mutated protein accumulation, and high glucose. Prolonged ER stress is a critical factor in the pathogenesis of metabolic syndrome including type 2 diabetes mellitus, cardiovascular diseases, atherosclerosis, obesity, and fatty liver disease. UPR is a complex homeostatic pathway between newly synthesized proteins and their maturation, although the regulatory mechanisms contributing to the UPR and the possible therapeutic strategies are yet to be clarified. Therefore, a comprehensive understanding of the underlying molecular mechanisms is necessary to develop therapeutic interventions targeting ER stress response. In this review, we discuss the role of ER stress and UPR signaling in the pathogenesis of metabolic syndrome, highlighting the main functions of UPR components. We have emphasized the use of novel small molecular chemical chaperones, considered as modulators of ER stress. The initial studies with these chemical chaperones are promising, but detailed studies are required to define their efficacy and adverse effects during therapeutic use in humans.
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Affiliation(s)
- Sreelekshmi Mohan
- Biochemistry and Molecular Mechanism Laboratory, Agroprocessing and Technology Division, CSIR-National Institute for Interdisciplinary Science and Technology, Industrial Estate, Thiruvananthapuram, 695019, Kerala, India; Academy of Scientific & Innovative Research (AcSIR), New Delhi, India
| | - Preetha Rani M R
- Biochemistry and Molecular Mechanism Laboratory, Agroprocessing and Technology Division, CSIR-National Institute for Interdisciplinary Science and Technology, Industrial Estate, Thiruvananthapuram, 695019, Kerala, India; Academy of Scientific & Innovative Research (AcSIR), New Delhi, India
| | - Lindsay Brown
- School of Health and Wellbeing/Functional Foods Research Group, University of Southern Queensland, Toowoomba, QLD, 4350, Australia
| | - Prathapan Ayyappan
- Department of Surgery-Transplant, University of Nebraska Medical Center, Omaha, NE, USA
| | - Raghu K G
- Biochemistry and Molecular Mechanism Laboratory, Agroprocessing and Technology Division, CSIR-National Institute for Interdisciplinary Science and Technology, Industrial Estate, Thiruvananthapuram, 695019, Kerala, India; Academy of Scientific & Innovative Research (AcSIR), New Delhi, India.
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35
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Inhibition of endoplasmic reticulum stress in high-fat-diet-induced obese C57BL/6 mice: Efficacy of a novel extract from mulberry ( Morus alba) leaves fermented with Cordyceps militaris. Lab Anim Res 2018; 34:288-294. [PMID: 30671117 PMCID: PMC6333616 DOI: 10.5625/lar.2018.34.4.288] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/16/2018] [Revised: 12/08/2018] [Accepted: 12/09/2018] [Indexed: 12/22/2022] Open
Abstract
A few clues about correlation between endoplasmic reticulum (ER) stress and mulberry (Morus alba) leaves were investigated in only the experimental autoimmune myocarditis and streptozotocin-induced diabetes. To investigate whether a novel extract of mulberry leaves fermented with Cordyceps militaris (EMfC) could suppress ER in fatty liver, alterations in the key parameters for ER stress response were measured in high fat diet (HFD)-induced obese C57L/6 mice treated with EMfC for 12 weeks. The area of adipocytes in the liver section were significantly decreased in the HFD+EMfC treated group as compared to the HFD+Vehicle treated group, while their level was higher in HFD+Vehicle treated group than No treated group. The level of the eukaryotic initiation factor 2 alpha (eIF2α) and inositol-requiring enzyme 1 beta (IRE1α) phosphorylation and CCAAT-enhancer-binding protein homologous protein (CHOP) expression were remarkably enhanced in the HFD+Vehicle treated group. However, their levels were restored in the HFD+EMfC treated group, although some differences were detected in the decrease rate. Similar recovery was observed on the ER stress-induced apoptosis. The level of Caspase-3, Bcl-2 and Bax were decreased in the HFD+EMfC and HFD+orlistat (OT) treated group compared to the HFD+Vehicle treated group. The results of the present study therefore provide first evidence that EMfC with the anti-obesity effects can be suppressed ER stress and ER stress-induced apoptosis in the hepatic steatosis of HFD-induced obesity model.
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36
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Yu X, Deng Q, Tang Y, Xiao L, Liu L, Yao P, Tang H, Dong X. Flaxseed Oil Attenuates Hepatic Steatosis and Insulin Resistance in Mice by Rescuing the Adaption to ER Stress. JOURNAL OF AGRICULTURAL AND FOOD CHEMISTRY 2018; 66:10729-10740. [PMID: 30145885 DOI: 10.1021/acs.jafc.8b03906] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/08/2023]
Abstract
Increasing evidence has demonstrated the benefits of α-linolenic acid-rich flaxseed oil (ALA-FO) against lipid metabolism abnormality in both rodent models and humans. However, the metabolic response of FO to insulin resistance and type 2 diabetes is still inconsistent. This study aimed to explore the effect of FO on chronic high fat diet (HFD)-induced hepatic steatosis, insulin resistance, and inflammation, mainly focusing on hepatic n-3 fatty acid remodeling and endoplasmic reticulum (ER) unfolded protein response. The results showed that lard-based HFD feeding for 16 weeks (60% fat-derived calories) induced whole-body insulin resistance, lipid profile abnormality, and inflammation in mice, which was alleviated by FO in a dose-dependent manner. Moreover, FO effectively improved hepatic steatosis and insulin resistance in mice by modulating the specific location of ALA and its long-chain n-3 fatty acids across hepatic lipid fractions and enhancing insulin-stimulated phosphorylation of hepatic insulin receptor subtract-1 (IRS-1) tyrosine 632 and protein kinase B (AKT) ( p < 0.05). Importantly, the differential depositions of ALA and its long-chain n-3 fatty acids in plasma and ER membranes were observed, concomitant with the rescued ER unfolded protein response and Jun N-terminal kinase (JNK) signaling in mice liver.
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Affiliation(s)
- Xiao Yu
- College of Food and Biological Engineering, Henan Collaborative Innovation Center for Food Production and Safety, Henan Key Laboratory of Cold Chain Food Quality and Safety Control , Zhengzhou University of Light Industry , Zhengzhou 450002 , China
| | - Qianchun Deng
- Oil Crops Research Institute, Hubei Key Laboratory of Lipid Chemistry and Nutrition, and Key Laboratory of Oilseeds Processing, Ministry of Agriculture , Chinese Academy of Agricultural Sciences , Wuhan 430062 , China
| | - Yuhan Tang
- Department of Nutrition and Food Hygiene and MOE Key Laboratory of Environment and Health, School of Public Health , Tongji Medical College, Huazhong University of Science and Technology , Wuhan 430030 , China
| | - Lin Xiao
- Department of Nutrition and Food Hygiene and MOE Key Laboratory of Environment and Health, School of Public Health , Tongji Medical College, Huazhong University of Science and Technology , Wuhan 430030 , China
| | - Liegang Liu
- Department of Nutrition and Food Hygiene and MOE Key Laboratory of Environment and Health, School of Public Health , Tongji Medical College, Huazhong University of Science and Technology , Wuhan 430030 , China
| | - Ping Yao
- Department of Nutrition and Food Hygiene and MOE Key Laboratory of Environment and Health, School of Public Health , Tongji Medical College, Huazhong University of Science and Technology , Wuhan 430030 , China
| | - Hu Tang
- Oil Crops Research Institute, Hubei Key Laboratory of Lipid Chemistry and Nutrition, and Key Laboratory of Oilseeds Processing, Ministry of Agriculture , Chinese Academy of Agricultural Sciences , Wuhan 430062 , China
| | - Xuyan Dong
- Oil Crops Research Institute, Hubei Key Laboratory of Lipid Chemistry and Nutrition, and Key Laboratory of Oilseeds Processing, Ministry of Agriculture , Chinese Academy of Agricultural Sciences , Wuhan 430062 , China
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Parafati M, Kirby RJ, Khorasanizadeh S, Rastinejad F, Malany S. A nonalcoholic fatty liver disease model in human induced pluripotent stem cell-derived hepatocytes, created by endoplasmic reticulum stress-induced steatosis. Dis Model Mech 2018; 11:11/9/dmm033530. [PMID: 30254132 PMCID: PMC6176998 DOI: 10.1242/dmm.033530] [Citation(s) in RCA: 36] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/08/2018] [Accepted: 08/08/2018] [Indexed: 12/14/2022] Open
Abstract
Hepatic steatosis, a reversible state of metabolic dysregulation, can promote the onset of nonalcoholic steatohepatitis (NASH), and its transition is thought to be critical in disease evolution. The association between endoplasmic reticulum (ER) stress response and hepatocyte metabolism disorders prompted us to characterize ER stress-induced hepatic metabolic dysfunction in human induced pluripotent stem cell-derived hepatocytes (hiPSC-Hep), to explore regulatory pathways and validate a phenotypic in vitro model for progression of liver steatosis. We treated hiPSC-Hep with a ratio of unsaturated and saturated fatty acids in the presence of an inducer of ER stress to synergistically promote triglyceride accumulation and dysregulate lipid metabolism. We monitored lipid accumulation by high-content imaging and measured gene regulation by RNA sequencing and reverse transcription quantitative PCR analyses. Our results show that ER stress potentiated intracellular lipid accumulation by 5-fold in hiPSC-Hep in the absence of apoptosis. Transcriptome pathway analysis identified ER stress pathways as the most significantly dysregulated of all pathways affected. Obeticholic acid dose dependently inhibited lipid accumulation and modulated gene expression downstream of the farnesoid X receptor. We were able to identify modulation of hepatic markers and gene pathways known to be involved in steatosis and nonalcoholic fatty liver disease (NAFLD), in support of a hiPSC-Hep disease model that is relevant to clinical data for human NASH. Our results show that the model can serve as a translational discovery platform for the understanding of molecular pathways involved in NAFLD, and can facilitate the identification of novel therapeutic molecules based on high-throughput screening strategies. Summary: Our study demonstrates expanded use of human induced pluripotent stem cell-derived hepatocytes for molecular studies and drug screening, to evaluate new therapeutics with an antisteatotic mechanism of action for nonalcoholic fatty liver disease.
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Affiliation(s)
- Maddalena Parafati
- Translational Biology, Conrad Prebys Center for Chemical Genomics, Orlando, FL 32827, USA
| | - R Jason Kirby
- Translational Biology, Conrad Prebys Center for Chemical Genomics, Orlando, FL 32827, USA
| | - Sepideh Khorasanizadeh
- Center for Metabolic Origins of Disease, Sanford Burham Prebys Medical Discovery Institute, 6400 Sanger Rd, Orlando, FL 32827, USA
| | - Fraydoon Rastinejad
- Center for Metabolic Origins of Disease, Sanford Burham Prebys Medical Discovery Institute, 6400 Sanger Rd, Orlando, FL 32827, USA
| | - Siobhan Malany
- Translational Biology, Conrad Prebys Center for Chemical Genomics, Orlando, FL 32827, USA
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Jiang D, Wan F. Exendin-4 protects INS-1 cells against palmitate-induced apoptosis through the IRE1α-Xbp1 signaling pathway. Exp Ther Med 2018; 16:1029-1035. [PMID: 30112049 DOI: 10.3892/etm.2018.6240] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/19/2017] [Accepted: 05/24/2018] [Indexed: 12/16/2022] Open
Abstract
The anti-apoptotic effect of the incretin analog, exendin-4 (EX-4) on pancreatic β cells is mediated via the activation of protein kinase B (Akt) signaling, and its effect is partly produced through the inhibition of endoplasmic reticulum (ER) stress. However, the molecular mechanisms that underlie the effect of EX-4 on the suppression of ER stress and the upregulation of Akt signaling are poorly understood. Inositol-requiring enzyme 1 (IRE1), a member of the ER-localized transmembrane protein family, activates its downstream transcription factor X-box binding protein 1 (XBP1) to mediate a key part of the cellular unfolded protein response in order to cope with ER stress. Using the clonal rat pancreatic β cell line INS-1, the present study produced an in vitro model of ER stress using palmitate (PA) in order to determine whether the beneficial effect of EX-4 under ER stress was regulated by the IRE1α-Xbp1 signaling pathway. The results demonstrated that the reduction in ER stress and the activation Akt by EX-4 may be associated with the upregulation of IRE1α phosphorylation and the splicing of Xbp1 mRNA, which improved PA-reduced cell viability. This effect was partially abrogated by the knockdown of IRE1α with small interfering RNA. Additionally, cellular IRE1α was phosphorylated by the protein kinase A (PKA) associated with EX-4 and the activation of IRE1α, as IRE1α phosphorylation was attenuated by the inhibition of PKA with its inhibitor. In conclusion, the data identified the IRE1α-Xbp1 signaling pathway as an essential mediator that associates EX-4 with the intracellular mechanism that inhibits ER stress and activates Akt in order to regulate β cell survival. This may provide important evidence for the use of EX-4 in treatments for type 2 diabetes.
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Affiliation(s)
- Dongdong Jiang
- Department of Endocrinology and Metabolism, Huashan Hospital, Shanghai Medical College, Fudan University, Shanghai 200040, P.R. China
| | - Fang Wan
- Department of Orthopedic Sports Medicine, Huashan Hospital, Fudan University, Shanghai 200040, P.R. China
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Ebersbach-Silva P, Poletto AC, David-Silva A, Seraphim PM, Anhê GF, Passarelli M, Furuya DT, Machado UF. Palmitate-induced Slc2a4/GLUT4 downregulation in L6 muscle cells: evidence of inflammatory and endoplasmic reticulum stress involvement. Lipids Health Dis 2018; 17:64. [PMID: 29609616 PMCID: PMC5879605 DOI: 10.1186/s12944-018-0714-8] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/06/2017] [Accepted: 03/21/2018] [Indexed: 12/22/2022] Open
Abstract
Background Obesity is strongly associated to insulin resistance, inflammation, and elevated plasma free fatty acids, but the mechanisms behind this association are not fully comprehended. Evidences suggest that endoplasmic reticulum (ER) stress may play a role in this complex pathophysiology. The aim of the present study was to investigate the involvement of inflammation and ER stress in the modulation of glucose transporter GLUT4, encoded by Slc2a4 gene, in L6 skeletal muscle cells. Methods L6 cells were acutely (2 h) and chronically (6 and 12 h) exposed to palmitate, and the expression of several proteins involved in insulin resistance, ER stress and inflammation were analyzed. Results Chronic and acute palmitate exposure significantly reduced GLUT4 protein (~ 39%, P < 0.01) and its mRNA (18%, P < 0.01) expression. Only acute palmitate treatment increased GRP78 (28%, P < 0.05), PERK (98%, P < 0.01), eIF-2A (35%, P < 0.01), IRE1a (60%, P < 0.05) and TRAF2 (23%, P < 0.05) protein content, and PERK phosphorylation (106%, P < 0.001), but did not elicit eIF-2A, IKK phosphorylation or increased XBP1 nuclear content. Additionally, acute and chronic palmitate increased NFKB p65 nuclear content (~ 30%, P < 0.05) and NFKB binding activity to Slc2a4 gene promoter (~ 45%, P < 0.05). Conclusion Different pathways are activated in acute and chronic palmitate induced-repression of Slc2a4/GLUT4 expression. This regulation involves activation of initial component of ER stress, such as the formation of a IRE1a-TRAF2-IKK complex, and converges to NFKB-induced repression of Slc2a4/GLUT4. These results link ER stress, inflammation and insulin resistance in L6 cells.
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Affiliation(s)
- Patrícia Ebersbach-Silva
- Department of Physiology and Biophysics, Institute of Biomedical Sciences, University of São Paulo, Av. Prof. Lineu Prestes 1524, São Paulo, 05508-900, Brazil
| | - Ana Cláudia Poletto
- Department of Physiology and Biophysics, Institute of Biomedical Sciences, University of São Paulo, Av. Prof. Lineu Prestes 1524, São Paulo, 05508-900, Brazil
| | - Aline David-Silva
- Department of Physiology and Biophysics, Institute of Biomedical Sciences, University of São Paulo, Av. Prof. Lineu Prestes 1524, São Paulo, 05508-900, Brazil
| | - Patrícia Monteiro Seraphim
- Department of Physical Therapy, School of Science and Technology, Universidade Estadual Paulista, São Paulo, Brazil
| | - Gabriel Forato Anhê
- Department of Pharmacology, Faculty of Medical Sciences, State University of Campinas, Campinas, Brazil
| | - Marisa Passarelli
- Laboratório de Lípides (LIM-10), Hospital das Clinicas HCFMUSP, Faculdade de Medicina, Universidade de Sao Paulo, Sao Paulo, SP, Brazil
| | - Daniela Tomie Furuya
- Department of Physiology and Biophysics, Institute of Biomedical Sciences, University of São Paulo, Av. Prof. Lineu Prestes 1524, São Paulo, 05508-900, Brazil
| | - Ubiratan Fabres Machado
- Department of Physiology and Biophysics, Institute of Biomedical Sciences, University of São Paulo, Av. Prof. Lineu Prestes 1524, São Paulo, 05508-900, Brazil.
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40
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Martin-Jiménez CA, García-Vega Á, Cabezas R, Aliev G, Echeverria V, González J, Barreto GE. Astrocytes and endoplasmic reticulum stress: A bridge between obesity and neurodegenerative diseases. Prog Neurobiol 2017; 158:45-68. [DOI: 10.1016/j.pneurobio.2017.08.001] [Citation(s) in RCA: 33] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2017] [Revised: 05/22/2017] [Accepted: 08/04/2017] [Indexed: 12/13/2022]
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41
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Shinjo S, Jiang S, Nameta M, Suzuki T, Kanai M, Nomura Y, Goda N. Disruption of the mitochondria-associated ER membrane (MAM) plays a central role in palmitic acid–induced insulin resistance. Exp Cell Res 2017; 359:86-93. [DOI: 10.1016/j.yexcr.2017.08.006] [Citation(s) in RCA: 39] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/07/2017] [Revised: 07/10/2017] [Accepted: 08/02/2017] [Indexed: 12/19/2022]
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42
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Park S, Paik YK. Genetic deficiency in neuronal peroxisomal fatty acid β-oxidation causes the interruption of dauer development in Caenorhabditis elegans. Sci Rep 2017; 7:9358. [PMID: 28839231 PMCID: PMC5571181 DOI: 10.1038/s41598-017-10020-x] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/20/2017] [Accepted: 08/02/2017] [Indexed: 11/11/2022] Open
Abstract
Although peroxisomal fatty acid (FA) β-oxidation is known to be critical for animal development, the cellular mechanisms that control the manner in which its neuronal deficiency causes developmental defects remain unclear. To elucidate the potential cellular consequences of neuronal FA metabolic disorder for dauer development, an alternative developmental process in Caenorhabditis elegans that occurs during stress, we investigated the sequential effects of its corresponding genetic deficiency. Here, we show that the daf-22 gene in peroxisomal FA β-oxidation plays a distinct role in ASK neurons, and its deficiency interrupts dauer development even in the presence of the exogenous ascaroside pheromones that induce such development. Un-metabolized FAs accumulated in ASK neurons of daf-22 mutants stimulate the endoplasmic reticulum (ER) stress response, which may enhance the XBP-1 activity that promotes the transcription of neuronal insulin-like peptides. These sequential cell-autonomous reactions in ASK neurons then activate insulin/IGF-1 signaling, which culminates in the suppression of DAF-16/FOXO activity. This suppression results in the interruption of dauer development, independently of pheromone presence. These findings suggest that neuronal peroxisomal FA β-oxidation is indispensable for animal development by regulating the ER stress response and neuroendocrine signaling.
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Affiliation(s)
- Saeram Park
- Department of Integrated OMICS for Biomedical Science, Yonsei University, 50 Yonsei-ro, Seodaemun-gu, Seoul, 03722, Republic of Korea
| | - Young-Ki Paik
- Department of Integrated OMICS for Biomedical Science, Yonsei University, 50 Yonsei-ro, Seodaemun-gu, Seoul, 03722, Republic of Korea.
- Department of Biochemistry, College of Life Science, Yonsei University, 50 Yonsei-ro, Seodaemun-gu, Seoul, 03722, Republic of Korea.
- Yonsei Proteome Research Center, Yonsei University, 50 Yonsei-ro, Seodaemun-gu, Seoul, 03722, Republic of Korea.
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von Loeffelholz C, Döcke S, Lock JF, Lieske S, Horn P, Kriebel J, Wahl S, Singmann P, de Las Heras Gala T, Grallert H, Raschzok N, Sauer IM, Heller R, Jahreis G, Claus RA, Bauer M, Stockmann M, Birkenfeld AL, Pfeiffer AFH. Increased lipogenesis in spite of upregulated hepatic 5'AMP-activated protein kinase in human non-alcoholic fatty liver. Hepatol Res 2017; 47:890-901. [PMID: 27689765 DOI: 10.1111/hepr.12825] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/20/2016] [Revised: 09/10/2016] [Accepted: 09/28/2016] [Indexed: 12/31/2022]
Abstract
AIMS Molecular adaptations in human non-alcoholic fatty liver disease (NAFLD) are incompletely understood. This study investigated the main gene categories related to hepatic de novo lipogenesis and lipid oxidation capacity. METHODS Liver specimens of 48 subjects were histologically classified according to steatosis severity. In-depth analyses were undertaken using real-time polymerase chain reaction, immunoblotting, and immunohistochemistry. Lipid profiles were analyzed by gas chromatography/flame ionization detection, and effects of key fatty acids were studied in primary human hepatocytes. RESULTS Real-time polymerase chain reaction, immunoblotting, and immunohistochemistry indicated 5'AMP-activated protein kinase (AMPK) to be increased with steatosis score ≥ 2 (all P < 0.05), including various markers of de novo lipogenesis and lipid degradation (all P < 0.05). Regarding endoplasmic reticulum stress, X-Box binding protein-1 (XBP1) was upregulated in steatosis score ≥ 2 (P = 0.029) and correlated with plasma palmitate (r = 0.34; P = 0.035). Palmitate incubation of primary human hepatocytes increased XBP1 and downstream stearoyl CoA desaturase-1 mRNA expression (both P < 0.05). Moreover, plasma and liver tissue exposed a NAFLD-related lipid profile with reduced polyunsaturated/saturated fatty acid ratio, increased palmitate and palmitoleate, and elevated lipogenesis and desaturation indices with steatosis score ≥ 2 (all P < 0.05). CONCLUSION In humans with advanced fatty liver disease, hepatic AMPK protein is upregulated, potentially in a compensatory manner. Moreover, pathways of lipid synthesis and degradation are co-activated in subjects with advanced steatosis. Palmitate may drive lipogenesis by activating XBP1-mediated endoplasmic reticulum stress and represent a target for future dietary or pharmacological intervention.
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Affiliation(s)
- Christian von Loeffelholz
- Department of Clinical Nutrition, German Institute of Human Nutrition, Potsdam-Rehbruecke, Germany.,Department of Anaesthesiology and Intensive Care, Jena University Hospital, and Integrated Research and Treatment Center, Center for Sepsis Control and Care (CSCC), Friedrich Schiller University, Jena, Germany.,German Center for Diabetes Research (DZD), München-Neuherberg, Germany
| | - Stephanie Döcke
- Department of Clinical Nutrition, German Institute of Human Nutrition, Potsdam-Rehbruecke, Germany
| | - Johan F Lock
- Department of General-, Visceral-, Vascular- and Paediatric Surgery, University Hospital of Wuerzburg, Wuerzburg, Germany
| | - Stefanie Lieske
- Section of Metabolic and Vascular Medicine, Medical Clinic III, University Hospital Carl Gustav Carus, Dresden, Germany
| | - Paul Horn
- Department of Anaesthesiology and Intensive Care, Jena University Hospital, and Integrated Research and Treatment Center, Center for Sepsis Control and Care (CSCC), Friedrich Schiller University, Jena, Germany
| | - Jennifer Kriebel
- German Center for Diabetes Research (DZD), München-Neuherberg, Germany.,Institute of Epidemiology II, Helmholtz Zentrum München, German Research Center for Environmental Health, Neuherberg, Germany.,Research Unit of Molecular Epidemiology, Helmholtz Zentrum München, German Research Center for Environmental Health, Neuherberg, Germany
| | - Simone Wahl
- German Center for Diabetes Research (DZD), München-Neuherberg, Germany.,Institute of Epidemiology II, Helmholtz Zentrum München, German Research Center for Environmental Health, Neuherberg, Germany.,Research Unit of Molecular Epidemiology, Helmholtz Zentrum München, German Research Center for Environmental Health, Neuherberg, Germany
| | - Paula Singmann
- Institute of Epidemiology II, Helmholtz Zentrum München, German Research Center for Environmental Health, Neuherberg, Germany.,Research Unit of Molecular Epidemiology, Helmholtz Zentrum München, German Research Center for Environmental Health, Neuherberg, Germany
| | - Tonia de Las Heras Gala
- German Center for Diabetes Research (DZD), München-Neuherberg, Germany.,Research Group of Diabetes Epidemiology, Institute of Epidemiology II, Helmholtz Zentrum München, German Research Center for Environmental Health, Neuherberg, Germany
| | - Harald Grallert
- German Center for Diabetes Research (DZD), München-Neuherberg, Germany.,Institute of Epidemiology II, Helmholtz Zentrum München, German Research Center for Environmental Health, Neuherberg, Germany.,Research Unit of Molecular Epidemiology, Helmholtz Zentrum München, German Research Center for Environmental Health, Neuherberg, Germany
| | - Nathaniel Raschzok
- Department of General, Visceral and Transplantation Surgery, Charité-Universitätsmedizin, Berlin, Germany
| | - Igor M Sauer
- Department of General, Visceral and Transplantation Surgery, Charité-Universitätsmedizin, Berlin, Germany
| | - Regine Heller
- Department of Anaesthesiology and Intensive Care, Jena University Hospital, and Integrated Research and Treatment Center, Center for Sepsis Control and Care (CSCC), Friedrich Schiller University, Jena, Germany.,Institute for Molecular Cell Biology, Germany, Center for Molecular Biomedicine, Jena University Hospital, Jena, Germany
| | - Gerhard Jahreis
- Institute of Nutrition, Friedrich Schiller University, Jena, Germany
| | - Ralf A Claus
- Department of Anaesthesiology and Intensive Care, Jena University Hospital, and Integrated Research and Treatment Center, Center for Sepsis Control and Care (CSCC), Friedrich Schiller University, Jena, Germany
| | - Michael Bauer
- Department of Anaesthesiology and Intensive Care, Jena University Hospital, and Integrated Research and Treatment Center, Center for Sepsis Control and Care (CSCC), Friedrich Schiller University, Jena, Germany
| | - Martin Stockmann
- Department of General, Visceral and Transplantation Surgery, Charité-Universitätsmedizin, Berlin, Germany
| | - Andreas L Birkenfeld
- Section of Metabolic and Vascular Medicine, Medical Clinic III, University Hospital Carl Gustav Carus, Dresden, Germany
| | - Andreas F H Pfeiffer
- Department of Clinical Nutrition, German Institute of Human Nutrition, Potsdam-Rehbruecke, Germany.,German Center for Diabetes Research (DZD), München-Neuherberg, Germany.,Department of Endocrinology, Diabetes, and Nutrition, Charité-Universitätsmedizin, Berlin, Germany
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44
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Abu Bakar MH, Sarmidi MR, Tan JS, Mohamad Rosdi MN. Celastrol attenuates mitochondrial dysfunction and inflammation in palmitate-mediated insulin resistance in C3A hepatocytes. Eur J Pharmacol 2017; 799:73-83. [PMID: 28161417 DOI: 10.1016/j.ejphar.2017.01.043] [Citation(s) in RCA: 31] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/17/2016] [Revised: 01/25/2017] [Accepted: 01/30/2017] [Indexed: 12/27/2022]
Abstract
Accumulating evidence indicates that mitochondrial dysfunction-induced inflammation is among the convergence points for the greatest hallmarks of hepatic insulin resistance. Celastrol, an anti-inflammatory compound from the root of Tripterygium Wilfordii has been reported to mitigate insulin resistance and inflammation in animal disease models. Nevertheless, the specific mechanistic actions of celastrol in modulating such improvements at the cellular level remain obscure. The present study sought to explore the mechanistic roles of celastrol upon insulin resistance induced by palmitate in C3A human hepatocytes. The hepatocytes exposed to palmitate (0.75mM) for 48h exhibited reduced both basal and insulin-stimulated glucose uptake, mitochondrial dysfunction, leading to increased mitochondrial oxidative stress with diminished fatty acid oxidation. Elevated expressions of nuclear factor-kappa B p65 (NF-κB p65), c-Jun NH(2)-terminal kinase (JNK) signaling pathways and the amplified release of pro-inflammatory cytokines including IL-8, IL-6, TNF-α and CRP were observed following palmitate treatment. Consistently, palmitate reduced and augmented phosphorylated Tyrosine-612 and Serine-307 of insulin receptor substrate-1 (IRS-1) proteins, respectively in hepatocytes. However, celastrol at the optimum concentration of 30nM was able to reverse these deleterious occasions and protected the cells from mitochondrial dysfunction and insulin resistance. Importantly, we presented evidence for the first time that celastrol efficiently prevented palmitate-induced insulin resistance in hepatocytes at least, via improved mitochondrial functions and insulin signaling pathways. In summary, the present investigation underlines a conceivable mechanism to elucidate the cytoprotective potential of celastrol in attenuating mitochondrial dysfunction and inflammation against the development of hepatic insulin resistance.
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Affiliation(s)
- Mohamad Hafizi Abu Bakar
- Bioprocess Technology Division, School of Industrial Technology, Universiti Sains Malaysia, 11800 Gelugor, Penang, Malaysia.
| | - Mohamad Roji Sarmidi
- Institute of Bioproduct Development, Universiti Teknologi Malaysia, 81310 Johor Bahru, Johor, Malaysia; Innovation Centre in Agritechnology for Advanced Bioprocessing (ICA), Universiti Teknologi Malaysia, 81310, Johor Bahru, Johor, Malaysia
| | - Joo Shun Tan
- Bioprocess Technology Division, School of Industrial Technology, Universiti Sains Malaysia, 11800 Gelugor, Penang, Malaysia
| | - Mohamad Norisham Mohamad Rosdi
- Department of Bioprocess and Polymer Engineering, Faculty of Chemical and Energy Engineering, Universiti Teknologi Malaysia, 81310 Johor Bahru, Johor, Malaysia
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45
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Restaino RM, Deo SH, Parrish AR, Fadel PJ, Padilla J. Increased monocyte-derived reactive oxygen species in type 2 diabetes: role of endoplasmic reticulum stress. Exp Physiol 2017; 102:139-153. [PMID: 27859785 DOI: 10.1113/ep085794] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/14/2016] [Accepted: 11/16/2016] [Indexed: 12/14/2022]
Abstract
NEW FINDINGS What is the central question of this study? Patients with type 2 diabetes exhibit increased oxidative stress in peripheral blood mononuclear cells, including monocytes; however, the mechanisms remain unknown. What is the main finding and its importance? The main finding of this study is that factors contained within the plasma of patients with type 2 diabetes can contribute to increased oxidative stress in monocytes, making them more adherent to endothelial cells. We show that these effects are largely mediated by the interaction between endoplasmic reticulum stress and NADPH oxidase activity. Recent evidence suggests that exposure of human monocytes to glucolipotoxic media to mimic the composition of plasma of patients with type 2 diabetes (T2D) results in the induction of endoplasmic reticulum (ER) stress markers and formation of reactive oxygen species (ROS). The extent to which these findings translate to patients with T2D remains unclear. Thus, we first measured ROS (dihydroethidium fluorescence) in peripheral blood mononuclear cells (PBMCs) from whole blood of T2D patients (n = 8) and compared the values with age-matched healthy control subjects (n = 8). The T2D patients exhibited greater basal intracellular ROS (mean ± SD, +3.4 ± 1.4-fold; P < 0.05) compared with control subjects. Next, the increase in ROS in PBMCs isolated from T2D patients was partly recapitulated in cultured human monocytes (THP-1 cells) exposed to plasma from T2D patients for 36 h (+1.3 ± 0.08-fold versus plasma from control subjects; P < 0.05). In addition, we found that increased ROS formation in THP-1 cells treated with T2D plasma was NADPH oxidase derived and led to increased endothelial cell adhesion (+1.8 ± 0.5-fold; P < 0.05) and lipid uptake (+1.3 ± 0.3-fold; P < 0.05). Notably, we found that T2D plasma-induced monocyte ROS and downstream functional effects were abolished by treating cells with tauroursodeoxycholic acid, a chemical chaperone known to inhibit ER stress. Collectively, these data indicate that monocyte ROS production with T2D can be attributed, in part, to signals from the circulating environment. Furthermore, an interplay between ER stress and NADPH oxidase activity contributes to ROS production and may be a mechanism mediating endothelial cell adhesion and foam cell formation in T2D.
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Affiliation(s)
- Robert M Restaino
- Department of Medical Pharmacology and Physiology, University of Missouri, Columbia, MO, USA
| | - Shekhar H Deo
- Department of Medical Pharmacology and Physiology, University of Missouri, Columbia, MO, USA
| | - Alan R Parrish
- Department of Medical Pharmacology and Physiology, University of Missouri, Columbia, MO, USA
| | - Paul J Fadel
- Department of Kinesiology, University of Texas-Arlington, Arlington, TX, USA
| | - Jaume Padilla
- Department of Nutrition and Exercise Physiology, University of Missouri, Columbia, MO, USA.,Dalton Cardiovascular Research Center, University of Missouri, Columbia, MO, USA.,Department of Child Health, University of Missouri, Columbia, MO, USA
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46
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Barger SW. Gene regulation and genetics in neurochemistry, past to future. J Neurochem 2016; 139 Suppl 2:24-57. [PMID: 27747882 DOI: 10.1111/jnc.13629] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/27/2015] [Revised: 03/01/2016] [Accepted: 03/30/2016] [Indexed: 12/14/2022]
Abstract
Ask any neuroscientist to name the most profound discoveries in the field in the past 60 years, and at or near the top of the list will be a phenomenon or technique related to genes and their expression. Indeed, our understanding of genetics and gene regulation has ushered in whole new systems of knowledge and new empirical approaches, many of which could not have even been imagined prior to the molecular biology boon of recent decades. Neurochemistry, in the classic sense, intersects with these concepts in the manifestation of neuropeptides, obviously dependent upon the central dogma (the established rules by which DNA sequence is eventually converted into protein primary structure) not only for their conformation but also for their levels and locales of expression. But, expanding these considerations to non-peptide neurotransmitters illustrates how gene regulatory events impact neurochemistry in a much broader sense, extending beyond the neurochemicals that translate electrical signals into chemical ones in the synapse, to also include every aspect of neural development, structure, function, and pathology. From the beginning, the mutability - yet relative stability - of genes and their expression patterns were recognized as potential substrates for some of the most intriguing phenomena in neurobiology - those instances of plasticity required for learning and memory. Near-heretical speculation was offered in the idea that perhaps the very sequence of the genome was altered to encode memories. A fascinating component of the intervening progress includes evidence that the central dogma is not nearly as rigid and consistent as we once thought. And this mutability extends to the potential to manipulate that code for both experimental and clinical purposes. Astonishing progress has been made in the molecular biology of neurochemistry during the 60 years since this journal debuted. Many of the gains in conceptual understanding have been driven by methodological progress, from automated high-throughput sequencing instruments to recombinant-DNA vectors that can convey color-coded genetic modifications in the chromosomes of live adult animals. This review covers the highlights of these advances, both theoretical and technological, along with a brief window into the promising science ahead. This article is part of the 60th Anniversary special issue.
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Affiliation(s)
- Steven W Barger
- Department of Geriatrics, Department of Neurobiology and Developmental Sciences, University of Arkansas for Medical Sciences, Little Rock, Arkansas, USA. .,Geriatric Research Education and Clinical Center, Central Arkansas Veterans Healthcare System, Little Rock, Arkansas, USA.
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Calorie-induced ER stress suppresses uroguanylin satiety signaling in diet-induced obesity. Nutr Diabetes 2016; 6:e211. [PMID: 27214655 PMCID: PMC4895379 DOI: 10.1038/nutd.2016.18] [Citation(s) in RCA: 26] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/11/2016] [Revised: 03/16/2016] [Accepted: 04/07/2016] [Indexed: 12/14/2022] Open
Abstract
Background/Objectives: The uroguanylin-GUCY2C gut–brain axis has emerged as one component regulating feeding, energy homeostasis, body mass and metabolism. Here, we explore a role for this axis in mechanisms underlying diet-induced obesity (DIO). Subjects/Methods: Intestinal uroguanylin expression and secretion, and hypothalamic GUCY2C expression and anorexigenic signaling, were quantified in mice on high-calorie diets for 14 weeks. The role of endoplasmic reticulum (ER) stress in suppressing uroguanylin in DIO was explored using tunicamycin, an inducer of ER stress, and tauroursodeoxycholic acid (TUDCA), a chemical chaperone that inhibits ER stress. The impact of consumed calories on uroguanylin expression was explored by dietary manipulation. The role of uroguanylin in mechanisms underlying obesity was examined using Camk2a-Cre-ERT2-Rosa-STOPloxP/loxP-Guca2b mice in which tamoxifen induces transgenic hormone expression in brain. Results: DIO suppressed intestinal uroguanylin expression and eliminated its postprandial secretion into the circulation. DIO suppressed uroguanylin through ER stress, an effect mimicked by tunicamycin and blocked by TUDCA. Hormone suppression by DIO reflected consumed calories, rather than the pathophysiological milieu of obesity, as a diet high in calories from carbohydrates suppressed uroguanylin in lean mice, whereas calorie restriction restored uroguanylin in obese mice. However, hypothalamic GUCY2C, enriched in the arcuate nucleus, produced anorexigenic signals mediating satiety upon exogenous agonist administration, and DIO did not impair these responses. Uroguanylin replacement by transgenic expression in brain repaired the hormone insufficiency and reconstituted satiety responses opposing DIO and its associated comorbidities, including visceral adiposity, glucose intolerance and hepatic steatosis. Conclusions: These studies reveal a novel pathophysiological mechanism contributing to obesity in which calorie-induced suppression of intestinal uroguanylin impairs hypothalamic mechanisms regulating food consumption through loss of anorexigenic endocrine signaling. The correlative therapeutic paradigm suggests that, in the context of hormone insufficiency with preservation of receptor sensitivity, obesity may be prevented or treated by GUCY2C hormone replacement.
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Safiedeen Z, Andriantsitohaina R, Martinez MC. Dialogue between endoplasmic reticulum and mitochondria as a key actor of vascular dysfunction associated to metabolic disorders. Int J Biochem Cell Biol 2016; 77:10-14. [PMID: 27208732 DOI: 10.1016/j.biocel.2016.05.011] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/02/2016] [Accepted: 05/09/2016] [Indexed: 01/06/2023]
Abstract
Metabolic syndrome due to its association with increased risk of cardiovascular diseases and cardiac mortality, comprises a cluster of metabolic abnormalities such as central obesity, hyperglycemia, dyslipidemia, and hypertension. Recent studies have shown that metabolic syndrome patients exhibit impaired nitric oxide-mediated vasodilatation leading to endothelial dysfunction in addition to insulin resistance. Interestingly, development and maintenance of the unfolded protein response of the endoplasmic reticulum stress revealed a surprisingly direct link with metabolic syndrome and endothelial dysfunction. On the other hand, in metabolic disorders, interaction between endoplasmic reticulum and mitochondria is mandatory for the generation of mitochondrial oxidative stress and perturbation of mitochondrial function accounting, at least in part, for vascular dysfunction. Herein, we review the impact of the dialogue between endoplasmic reticulum and mitochondria in modulating the cellular signals governing vascular alterations associated to metabolic disorders.
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Affiliation(s)
- Zainab Safiedeen
- INSERM UMR1063, Université d'Angers, Angers, France; ER045, Laboratory of Stem Cells, PRASE, DSST, Lebanese University, Beirut, Lebanon
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Parker AL, Turner N, McCarroll JA, Kavallaris M. βIII-Tubulin alters glucose metabolism and stress response signaling to promote cell survival and proliferation in glucose-starved non-small cell lung cancer cells. Carcinogenesis 2016; 37:787-798. [PMID: 27207668 DOI: 10.1093/carcin/bgw058] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/14/2015] [Accepted: 04/29/2016] [Indexed: 12/12/2022] Open
Abstract
Non-small cell lung cancer (NSCLC) survival rates are dismal and high βIII-tubulin expression is associated with chemotherapy drug resistance and tumor aggressiveness in this disease. Mounting evidence supports a role for βIII-tubulin in promoting cell survival in the harsh tumor microenvironment, which is characterized by poor nutrient supply. This study aimed to investigate the role of βIII-tubulin in glucose stress response signaling and the survival and proliferation of NSCLC cells. This study revealed that βIII-tubulin regulates cellular metabolism and glucose stress response signaling in NSCLC cells to promote cell survival and proliferation in glucose starvation. βIII-Tubulin decreases the reliance of cells on glycolytic metabolism, priming them to cope with variable nutrient supply present within the tumor microenvironment. βIII-Tubulin protects cells from endoplasmic reticulum (ER) stress and reduces both basal and glucose starvation-induced autophagy to maintain cell survival and proliferation. βIII-Tubulin enables rapid Akt activation in response to glucose starvation and co-immunoprecipitates with the master regulator of the ER stress response GRP78. Furthermore, suppression of βIII-tubulin delays the association of GRP78 with Akt in response to glucose starvation with the potential to influence Akt activation and ER homeostasis under these conditions. Together these results identify that βIII-tubulin regulates glucose metabolism and alters glucose starvation stress signaling to promote cell proliferation and survival in NSCLC cells. This elucidates a hitherto unknown role for this microtubule protein and provides insight into correlations between high βIII-tubulin expression and poor patient outcome in this disease.
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Affiliation(s)
- Amelia L Parker
- Tumour Biology and Targeting Program, Children's Cancer Institute, UNSW Lowy Cancer Research Centre, Randwick, NSW 2031, Australia.,Australian Centre for Nanomedicine and ARC Centre of Excellence in Convergent Bio-Nano Science and Technology, UNSW Australia, Sydney, NSW 2052, Australia and
| | - Nigel Turner
- Department of Pharmacology, School of Medical Sciences, UNSW Australia, Sydney, NSW 2052, Australia
| | - Joshua A McCarroll
- Tumour Biology and Targeting Program, Children's Cancer Institute, UNSW Lowy Cancer Research Centre, Randwick, NSW 2031, Australia.,Australian Centre for Nanomedicine and ARC Centre of Excellence in Convergent Bio-Nano Science and Technology, UNSW Australia, Sydney, NSW 2052, Australia and
| | - Maria Kavallaris
- Tumour Biology and Targeting Program, Children's Cancer Institute, UNSW Lowy Cancer Research Centre, Randwick, NSW 2031, Australia.,Australian Centre for Nanomedicine and ARC Centre of Excellence in Convergent Bio-Nano Science and Technology, UNSW Australia, Sydney, NSW 2052, Australia and
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50
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Anti-diabetic effect of 3-hydroxy-2-naphthoic acid, an endoplasmic reticulum stress-reducing chemical chaperone. Eur J Pharmacol 2016; 779:157-67. [PMID: 26983645 DOI: 10.1016/j.ejphar.2016.03.023] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/20/2015] [Revised: 03/11/2016] [Accepted: 03/11/2016] [Indexed: 01/22/2023]
Abstract
Lots of experimental and clinical evidences indicate that chronic exposure to saturated fatty acids and high level of glucose is implicated in insulin resistance, beta cell failure and ultimately type 2 diabetes. In this study, we set up cell-based experimental conditions to induce endoplasmic reticulum (ER) stress and insulin resistance using high concentration of palmitate (PA). Hydroxynaphthoic acids (HNAs) were formerly identified as novel chemical chaperones to resolve ER stress induced by tunicamycin. In this study, we found the compounds have the same suppressive effect on PA-induced ER stress in HepG2 cells. The representing compound, 3-HNA reduced PA-induced phosphorylation of JNK, IKKβ and IRS1 (S307) and restored insulin signaling cascade which involves insulin receptor β, IRS1 and Akt. The insulin sensitizing effect of 3-HNA was confirmed in 3T3-L1 adipocytes, where the compound augmented insulin signaling and glucose transporter 4 (GLUT4) membrane translocation. 3-HNA also protected the pancreatic beta cells from PA-induced apoptosis by reducing ER stress. Upon 3-HNA treatment to ob/ob mice at 150mg/kg/day dosage, the diabetic parameters including glucose tolerance and systemic insulin sensitivity were significantly improved. Postmortem examination showed that 3-HNA markedly reduced ER stress and insulin resistance in the liver tissues and it sensitized insulin signaling in the liver and the skeletal muscle. Our results demonstrated that 3-HNA can sensitize insulin signaling by coping with lipotoxicity-induced ER stress as a chemical chaperone and suggested it holds therapeutic potential for insulin resistance and type 2 diabetes.
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