1
|
Norberto S, Assalin HB, Guadagnini D, Tobar N, Boer PA, Kang MC, Saad MJA, Kim YB, Prada PO. CLK2 in GABAergic neurons is critical in regulating energy balance and anxiety-like behavior in a gender-specific fashion. Front Endocrinol (Lausanne) 2023; 14:1172835. [PMID: 37635967 PMCID: PMC10449579 DOI: 10.3389/fendo.2023.1172835] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/23/2023] [Accepted: 07/24/2023] [Indexed: 08/29/2023] Open
Abstract
Introduction Cdc2-like kinase (CLK2) is a member of CLK kinases expressed in hypothalamic neurons and is activated in response to refeeding, leptin, or insulin. Diet-induced obesity and leptin receptor-deficient db/db mice lack CLK2 signal in the hypothalamic neurons. The neurotransmiter gamma-aminobutyric acid (GABA) is among the most prevalent in the central nervous system (CNS), particularly in the hypothalamus. Given the abundance of GABA-expressing neurons and their potential influence on regulating energy and behavioral homeostasis, we aimed to explore whether the deletion of CLK2 in GABAergic neurons alters energy homeostasis and behavioral and cognitive functions in both genders of mice lacking CLK2 in Vgat-expressing neurons (Vgat-Cre; Clk2loxP/loxP) on chow diet. Methods We generated mice lacking Clk2 in Vgat-expressing neurons (Vgat-Cre; Clk2loxP/loxP) by mating Clk2loxP/loxP mice with Vgat-IRES-Cre transgenic mice and employed behavior, and physiological tests, and molecular approaches to investigate energy metabolism and behavior phenotype of both genders. Results and discussion We showed that deletion of CLK2 in GABAergic neurons increased adiposity and food intake in females. The mechanisms behind these effects were likely due, at least in part, to hypothalamic insulin resistance and upregulation of hypothalamic Npy and Agrp expression. Besides normal insulin and pyruvate sensitivity, Vgat-Cre; Clk2loxP/loxP females were glucose intolerant. Male Vgat-Cre; Clk2loxP/loxP mice showed an increased energy expenditure (EE). Risen EE may account for avoiding weight and fat mass gain in male Vgat-Cre; Clk2loxP/loxP mice. Vgat-Cre; Clk2loxP/loxP mice had no alteration in cognition or memory functions in both genders. Interestingly, deleting CLK2 in GABAergic neurons changed anxiety-like behavior only in females, not males. These findings suggest that CLK2 in GABAergic neurons is critical in regulating energy balance and anxiety-like behavior in a gender-specific fashion and could be a molecular therapeutic target for combating obesity associated with psychological disorders in females.
Collapse
Affiliation(s)
- Sónia Norberto
- Department of Internal Medicine, School of Medical Science, University of Campinas (UNICAMP), Campinas, SP, Brazil
| | - Heloisa Balan Assalin
- Department of Internal Medicine, School of Medical Science, University of Campinas (UNICAMP), Campinas, SP, Brazil
| | - Dioze Guadagnini
- Department of Internal Medicine, School of Medical Science, University of Campinas (UNICAMP), Campinas, SP, Brazil
| | - Natália Tobar
- Department of Radiology, University of Campinas (UNICAMP), Campinas, SP, Brazil
| | - Patrícia Aline Boer
- Department of Internal Medicine, Fetal Programming Laboratory, School of Medical Science, University of Campinas (UNICAMP), Campinas, SP, Brazil
| | - Min-Cheol Kang
- Division of Endocrinology, Diabetes and Metabolism, Department of Medicine, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, MA, United States
- Research Group of Food Processing, Korea Food Research Instute, Jeollabuk-do, Wanju, Republic of Korea
| | - Mario Jose Abdalla Saad
- Department of Internal Medicine, School of Medical Science, University of Campinas (UNICAMP), Campinas, SP, Brazil
| | - Young-Bum Kim
- Division of Endocrinology, Diabetes and Metabolism, Department of Medicine, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, MA, United States
| | - Patricia Oliveira Prada
- Department of Internal Medicine, School of Medical Science, University of Campinas (UNICAMP), Campinas, SP, Brazil
- School of Applied Sciences, University of Campinas (UNICAMP), Limeira, SP, Brazil
- Max-Planck Institute for Metabolism Research, Köln, Germany
| |
Collapse
|
2
|
Association between PTPN1 polymorphisms and obesity-related phenotypes in European adolescents: influence of physical activity. Pediatr Res 2022:10.1038/s41390-022-02377-1. [PMID: 36369476 DOI: 10.1038/s41390-022-02377-1] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/27/2022] [Revised: 10/06/2022] [Accepted: 10/23/2022] [Indexed: 11/13/2022]
Abstract
BACKGROUND To study the associations of Protein Tyrosine Phosphatase-N1 (PTPN1) polymorphisms with obesity-related phenotypes in European adolescents, and the influence of physical activity on these relationships. METHODS Five polymorphisms of PTPN1 were genotyped in 1057 European adolescents (12-18 years old). We measured several phenotypes related to obesity, such as adiposity markers, and biochemical and clinical parameters. Physical activity was objectively measured by accelerometry. RESULTS The T, A, T, T and G alleles of the rs6067472, rs10485614, rs2143511, rs6020608 and rs968701 polymorphisms, respectively, were associated with lower levels of obesity-related phenotypes (i.e., body mass index, body fat percentage, hip circumference, fat mass index, systolic blood pressure and leptin) in European adolescents. In addition, the TATTG haplotype was associated with lower body fat percentage and fat mass index compared to the AACCA haplotype. Finally, when physical activity levels were considered, alleles of the rs6067472, rs2143511, rs6020608 and rs968701 polymorphisms were only associated with lower adiposity in active adolescents. CONCLUSIONS PTPN1 polymorphisms were associated with adiposity in European adolescents. Specifically, alleles of these polymorphisms were associated with lower adiposity only in physically active adolescents. Therefore, meeting the recommendations of daily physical activity may reduce obesity risk by modulating the genetic predisposition to obesity. IMPACT Using gene-phenotype and gene*environment analyses, we detected associations between polymorphisms of the Protein Tyrosine Phosphatase-N1 (PTPN1) gene and obesity-related phenotypes, suggesting a mechanism that can be modulated by physical activity. This study shows that genetic variability of PTPN1 is associated with adiposity, while physical activity seems to modulate the genetic predisposition. This brings insights about the mechanisms by which physical activity positively influences obesity.
Collapse
|
3
|
Huo P, Li M, Le J, Zhu C, Yao J, Zhang S. Resveratrol improves follicular development of PCOS rats via regulating glycolysis pathway and targeting SIRT1. Syst Biol Reprod Med 2022; 69:153-165. [PMID: 36268996 DOI: 10.1080/19396368.2022.2125855] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 10/24/2022]
Abstract
Polycystic ovary syndrome (PCOS) is a disease characterized by metabolic disorders. This study aimed to examine the effects of resveratrol treatment on ovulation in the PCOS rat model. Quantitative real-time PCR and immunohistochemistry were used to determine the mRNA and protein expression levels. TNUEL assay was used to evaluate cell apoptosis in ovary. The metabolites were evaluated by liquid chromatography with tandem mass spectrometry. Resveratrol alleviated disrupted estrous cycle and improved granular cell layers, and reversed the decreased proliferation and increased cell apoptosis of granulosa cells in the ovarian tissues of PCOS rats. Resveratrol restored the changes in the mRNA expression levels in the rate-limiting genes of glycolysis in the PCOS ovary. The expression of lactate dehydrogenase A (LDH-A), pyruvate kinase isozyme M2 (PKM2), and sirtuin 1 (SIRT1) was significantly downregulated in ovarian tissues of the PCOS rats; while the resveratrol treatment significantly increased the expression of LDH-A, PKM2, and SIRT1 in the ovarian tissues of PCOS rats. Collectively, the protective effects of resveratrol in the PCOS rats may be associated with the regulation of glycolysis-related mediators including PKM2, LDH-A, and SIRT1. Resveratrol may represent a good candidate in alleviating the development of PCOS.
Collapse
Affiliation(s)
- Peng Huo
- Guangxi Key Laboratory of Environmental Exposomics and Entire Lifecycle Health, Guilin Medical University, Guilin, China
| | - Man Li
- Department of Reproductive Medical Center, The Affiliated Hospital of Guilin Medical University, Guilin, China
| | - Jianghua Le
- Department of Reproductive Medical Center, The Affiliated Hospital of Guilin Medical University, Guilin, China
| | - Chunjiang Zhu
- Department of Reproductive Medical Center, The Affiliated Hospital of Guilin Medical University, Guilin, China
| | - Jun Yao
- Department of Reproductive Medical Center, The Affiliated Hospital of Guilin Medical University, Guilin, China
| | - Shun Zhang
- Department of Reproductive Medical Center, The Affiliated Hospital of Guilin Medical University, Guilin, China
| |
Collapse
|
4
|
The Antidiabetic Activities of Neocryptotanshinone: Screened by Molecular Docking and Related to the Modulation of PTP1B. Nutrients 2022; 14:nu14153031. [PMID: 35893885 PMCID: PMC9330310 DOI: 10.3390/nu14153031] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/06/2022] [Revised: 07/19/2022] [Accepted: 07/20/2022] [Indexed: 01/27/2023] Open
Abstract
The aim of this study was to provide a practical experimental basis for the development of Neocryptotanshinone (NCTS) as an effective hypoglycemic drug and a theoretical method for the rapid screening of natural compounds with hypoglycemic effects. Molecular docking was used to screen the most suitable ligand. Hematoxylin and eosin, immunohistochemical staining, enzyme-linked immunosorbent assay and Western Blotting approved the hypoglycemic effect of NCTS. According to the free energy of binding, among 180 active compounds from the Traditional Chinese Medicine Integrated Database, NCTS was finally chose for investigation its hypoglycemic effects. In db/db mice, NCTS significantly reduced body weight and plasma glucose, improved glucose tolerance and levels of fasting plasma glucose and glycated hemoglobin A1c, and decreased insulin resistance after six-week administration. NCTS restored the pathological state in the liver of db/db mice and significantly decreased protein tyrosine phosphatase 1B (PTP1B) expression in the liver and muscle of db/db mice, which is related to the regulatory effect of NCTS on insulin receptor substrate 1. In conclusion, we successfully explored the hypoglycemic effect of NCTS in db/db mice via regulating the expression of PTP1B.
Collapse
|
5
|
Antunes GC, Lima RDD, Vieira RFL, Macêdo APA, Muñoz VR, Zambalde EP, Romeiro CF, Simabuco FM, Prada PO, da Silva ASR, Ropelle ER, Cintra DE, Pauli JR. RESISTANCE EXERCISE ATTENUATES IKKε PHOSPHORYLATION AND HEPATIC FAT ACCUMULATION OF OBESE MICE. Clin Exp Pharmacol Physiol 2022; 49:1072-1081. [PMID: 35690890 DOI: 10.1111/1440-1681.13687] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/27/2021] [Revised: 05/12/2022] [Accepted: 06/06/2022] [Indexed: 11/30/2022]
Abstract
Obesity is associated with low-grade inflammation and disturbances in hepatic metabolism. This study aimed to investigate the effects of resistance exercise on inflammatory signaling related to IKKepsilon protein (IKKɛ) and on hepatic fat accumulation in obese mice. Male Swiss mice were distributed into three groups: control (CTL) fed with standard chow; obese (OB) mice induced by a high-fat diet (HFD); obese exercised (OB+RE) mice fed with HFD and submitted to a resistance exercise training. The resistance exercise training protocol consisted of 20 sets/3 ladder climbs for eight weeks, three times/week on alternate days. The training overload was equivalent to 70% of the maximum load supported by the rodent. Assays were performed to evaluate weight gain, hepatic fat content, fasting glucose, insulin sensitivity, IKKɛ phosphorylation, and proteins related to insulin signaling and lipogenesis in the liver. Mice that received the high-fat diet showed greater adiposity, impaired insulin sensitivity, increased fasting glucose, and increased hepatic fat accumulation. These results were accompanied by an increase in IKKɛ phosphorylation and lipogenesis-related proteins such as cluster of differentiation 36 (CD36) and fatty acid synthase (FAS) in the liver of obese mice. In contrast, exercised mice showed lower body weight and adiposity evolution throughout the experiment. In addition, resistance exercise suppressed the effects of the high-fat diet by reducing IKKɛ phosphorylation and hepatic fat content. In conclusion, resistance exercise training improves hepatic fat metabolism and glycemic homeostasis, which are, at least in part, linked to the antiinflammatory effect of reduced IKKɛ phosphorylation in the liver of obese mice. This article is protected by copyright. All rights reserved.
Collapse
Affiliation(s)
- Gabriel Calheiros Antunes
- Laboratory of Molecular Biology of Exercise, University of Campinas (UNICAMP), Limeira, São Paulo, Brazil
| | - Robson Damasceno de Lima
- Laboratory of Molecular Biology of Exercise, University of Campinas (UNICAMP), Limeira, São Paulo, Brazil
| | - Renan Fudoli Lins Vieira
- Laboratory of Molecular Biology of Exercise, University of Campinas (UNICAMP), Limeira, São Paulo, Brazil
| | - Ana Paula Azevêdo Macêdo
- Laboratory of Molecular Biology of Exercise, University of Campinas (UNICAMP), Limeira, São Paulo, Brazil
| | - Vitor Rosetto Muñoz
- Laboratory of Molecular Biology of Exercise, University of Campinas (UNICAMP), Limeira, São Paulo, Brazil
| | - Erika Pereira Zambalde
- Multidisciplinary Laboratory of Food and Health, State University of Campinas, Faculty of Applied Sciences, Limeira, São Paulo, Brazil
| | - Caio Felipe Romeiro
- Multidisciplinary Laboratory of Food and Health, State University of Campinas, Faculty of Applied Sciences, Limeira, São Paulo, Brazil
| | - Fernando Moreira Simabuco
- Multidisciplinary Laboratory of Food and Health, State University of Campinas, Faculty of Applied Sciences, Limeira, São Paulo, Brazil
| | - Patricia Oliveira Prada
- Laboratory of Molecular Research in Obesity (Labimo), School of Applied Sciences, University of Campinas (UNICAMP), Limeira, São Paulo, Brazil
| | - Adelino Sanchez Ramos da Silva
- Postgraduate Program in Rehabilitation and Functional Performance, Ribeirão Preto Medical School, and Postgraduate Program in Physical Education and Sport, School of Physical Education and Sport of Ribeirão Preto, University of São Paulo (USP), Ribeirão Preto, São Paulo, Brazil
| | - Eduardo Rochete Ropelle
- Laboratory of Molecular Biology of Exercise, University of Campinas (UNICAMP), Limeira, São Paulo, Brazil.,OCRC - Obesity and Comorbidities Research Center, University of Campinas (UNICAMP), Campinas, São Paulo, Brazil
| | - Dennys Esper Cintra
- OCRC - Obesity and Comorbidities Research Center, University of Campinas (UNICAMP), Campinas, São Paulo, Brazil.,Laboratory of Nutritional Genomics, University of Campinas (UNICAMP), Limeira, São Paulo, Brazil
| | - José Rodrigo Pauli
- Laboratory of Molecular Biology of Exercise, University of Campinas (UNICAMP), Limeira, São Paulo, Brazil.,OCRC - Obesity and Comorbidities Research Center, University of Campinas (UNICAMP), Campinas, São Paulo, Brazil
| |
Collapse
|
6
|
Hsu YJ, Lee MC, Huang CC, Ho CS. The effects of different types of aquatic exercise training interventions on a high-fructose diet-fed mice. Int J Med Sci 2021; 18:695-705. [PMID: 33437204 PMCID: PMC7797553 DOI: 10.7150/ijms.52347] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/24/2020] [Accepted: 11/25/2020] [Indexed: 11/18/2022] Open
Abstract
Gradual weight gain in modern people and a lowering onset age of metabolic disease are highly correlated with the intake of sugary drinks and sweets. Long-term excessive fructose consumption can lead to hyperglycemia, hyperlipidemia and accumulation of visceral fat. Abdominal obesity is more severe in females than in males. In this study, we used a high-fructose-diet-induced model of obesity in female mice. We investigated the effects of aquatic exercise training on body weight and body composition. After 1 week of acclimatization, female ICR mice were randomly divided into two groups: a normal group (n=8) fed standard diet (control), and a high-fructose diet (HFD) group (n=24) fed a HFD. After 4 weeks of induction followed by 4 weeks of aquatic exercise training, the 24 obese mice were divided into 3 groups (n=8 per group): HFD with sedentary control (HFD), HFD with aquatic strength exercise training (HFD+SE), and HFD with aquatic aerobic exercise training (HFD+AE). We conducted serum biochemical profile analysis, weighed the white adipose tissue, and performed organ histopathology. After 4 weeks of induction and 4 weeks of aquatic exercise training, there was no significant difference in body weight among the HFD, HFD+SE and HFD+AE groups. Serum triglyceride (TG), AST, ALT, and uric acid level were significantly lower in the HFD+SE and HFD+AE groups than in the HFD group. The weight of the perirenal fat pad was significantly lower in the HFD+AE group than in the HFD group. Hepatic TG and total cholesterol (TC) were significantly lower in the HFD+AE group than in the other groups. Long-term intake of a high-fructose diet can lead to obesity and increase the risk of metabolic disease. Based on our findings, we speculate that aquatic exercise training can effectively promote health and fitness. However, aquatic aerobic exercise training appears to have greater benefits than aquatic strength exercise training.
Collapse
Affiliation(s)
- Yi-Ju Hsu
- Graduate Institute of Sports Science, National Taiwan Sport University, Taoyuan 333325, Taiwan
| | - Mon-Chien Lee
- Graduate Institute of Sports Science, National Taiwan Sport University, Taoyuan 333325, Taiwan
| | - Chi-Chang Huang
- Graduate Institute of Sports Science, National Taiwan Sport University, Taoyuan 333325, Taiwan
| | - Chun-Sheng Ho
- Department of Physical Therapy, College of Medical and Health Science, Asia University, Taichung 41354, Taiwan.,Division of Physical Medicine and Rehabilitation, Lo-Hsu Medical Foundation, Inc., Lotung Poh-Ai Hospital, Yilan 26546, Taiwan
| |
Collapse
|
7
|
Muñoz VR, Gaspar RC, Kuga GK, Pavan ICB, Simabuco FM, da Silva ASR, de Moura LP, Cintra DE, Ropelle ER, Pauli JR. The Effects of Aging on Rho-Kinase and Insulin Signaling in Skeletal Muscle and White Adipose Tissue of Rats. J Gerontol A Biol Sci Med Sci 2020; 75:432-436. [PMID: 30596894 DOI: 10.1093/gerona/gly293] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/05/2017] [Indexed: 12/21/2022] Open
Abstract
The insulin receptor substrate 1 regulates insulin-mediated glucose uptake and is a target of Rho-kinase (Rock); however, the relationship between age-related insulin resistance and Rock signaling specifically in skeletal muscle and adipose tissue is unknown. We evaluated the content and activity of Rock in C2C12 myotubes, and in skeletal muscle and white adipose tissue (WAT) from two rodent models that differ in their patterns of body fat accumulation during aging (Wistar and Fischer 344 rats). Body fat gain in the Wistar rats was greater than in Fischer rats and only Wistar rats had impairment of whole-body insulin sensitivity. Rock activity and insulin signaling were impaired in skeletal muscle in both rat models, but only middle-aged Wistar rats had higher Rock activity in WAT. These data are consistent with a positive role of Rock in regulating insulin signaling in both skeletal muscle and its negative role in the adipose tissue, suggesting that Rock activity in adipose tissue is important in age-related insulin resistance.
Collapse
Affiliation(s)
- Vitor Rosetto Muñoz
- Laboratory of Molecular Biology of Exercise, University of Campinas (UNICAMP), Limeira, São Paulo, Brazil
| | - Rafael Calais Gaspar
- Laboratory of Molecular Biology of Exercise, University of Campinas (UNICAMP), Limeira, São Paulo, Brazil
| | - Gabriel Keine Kuga
- Laboratory of Molecular Biology of Exercise, University of Campinas (UNICAMP), Limeira, São Paulo, Brazil
| | - Isadora Carolina Betim Pavan
- Laboratory of Functional Properties in Foods, School of Applied Sciences (FCA), University of Campinas (UNICAMP), Limeira, São Paulo, Brazil
| | - Fernando Moreira Simabuco
- Laboratory of Functional Properties in Foods, School of Applied Sciences (FCA), University of Campinas (UNICAMP), Limeira, São Paulo, Brazil
| | - Adelino Sanchez Ramos da Silva
- Postgraduate Program in Rehabilitation and Functional Performance, Ribeirão Preto Medical School, USP, Ribeirão Preto, São Paulo, Brazil.,School of Physical Education and Sport of Ribeirão Preto, University of São Paulo (USP), Ribeirão Preto, São Paulo, Brazil
| | - Leandro Pereira de Moura
- Laboratory of Molecular Biology of Exercise, University of Campinas (UNICAMP), Limeira, São Paulo, Brazil.,OCRC - Obesity and Comorbidities Research Center, University of Campinas (UNICAMP), Campinas, São Paulo, Brazil.,Postgraduate Program in Motor Science - São Paulo State University (UNESP).,CEPECE - Center of Research in Sport Sciences. School of Applied Sciences, University of Campinas (UNICAMP), Limeira, São Paulo, Brazil
| | - Dennys Esper Cintra
- OCRC - Obesity and Comorbidities Research Center, University of Campinas (UNICAMP), Campinas, São Paulo, Brazil.,Laboratory of Nutritional Genomics, University of Campinas (UNICAMP), Limeira, São Paulo, Brazil
| | - Eduardo Rochete Ropelle
- Laboratory of Molecular Biology of Exercise, University of Campinas (UNICAMP), Limeira, São Paulo, Brazil.,OCRC - Obesity and Comorbidities Research Center, University of Campinas (UNICAMP), Campinas, São Paulo, Brazil.,CEPECE - Center of Research in Sport Sciences. School of Applied Sciences, University of Campinas (UNICAMP), Limeira, São Paulo, Brazil
| | - José Rodrigo Pauli
- Laboratory of Molecular Biology of Exercise, University of Campinas (UNICAMP), Limeira, São Paulo, Brazil.,OCRC - Obesity and Comorbidities Research Center, University of Campinas (UNICAMP), Campinas, São Paulo, Brazil.,CEPECE - Center of Research in Sport Sciences. School of Applied Sciences, University of Campinas (UNICAMP), Limeira, São Paulo, Brazil
| |
Collapse
|
8
|
Shu XS, Zhu H, Huang X, Yang Y, Wang D, Zhang Y, Zhang W, Ying Y. Loss of β-catenin via activated GSK3β causes diabetic retinal neurodegeneration by instigating a vicious cycle of oxidative stress-driven mitochondrial impairment. Aging (Albany NY) 2020; 12:13437-13462. [PMID: 32575075 PMCID: PMC7377872 DOI: 10.18632/aging.103446] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/17/2020] [Accepted: 04/28/2020] [Indexed: 02/06/2023]
Abstract
Synaptic neurodegeneration of retinal ganglion cells (RGCs) is the earliest event in the pathogenesis of diabetic retinopathy. Our previous study proposed that impairment of mitochondrial trafficking by hyperphosphorylated tau is a potential contributor to RGCs synapse degeneration. However, other molecular mechanisms underlying mitochondrial defect in diabetic retinal neurodegeneration remain to be elucidated. Here, using a high-fat diet (HFD)-induced diabetic mouse model, we showed for the first time that downregulation of active β-catenin due to abnormal GSK3β activation caused synaptic neurodegeneration of RGCs by inhibiting ROS scavenging enzymes, thus triggering oxidative stress-driven mitochondrial impairment in HFD-induced diabetes. Rescue of β-catenin via ectopic expression of β-catenin with a recombinant adenoviral vector, or via GSK3β inhibition by a targeted si-GSK3β, through intravitreal administration, abrogated the oxidative stress-derived mitochondrial defect and synaptic neurodegeneration in diabetic RGCs. By contrast, ablation of β-catenin by si-β-catenin abolished the protective effect of GSK3β inhibition on diabetic RGCs by suppression of antioxidant scavengers and augmentation of oxidative stress-driven mitochondrial lesion. Thus, our data identify β-catenin as a part of an endogenous protective system in diabetic RGCs and a promising target to develop intervention strategies that protect RGCs from neurodegeneration at early onset of diabetic retinopathy.
Collapse
Affiliation(s)
- Xing-Sheng Shu
- Department of Physiology, School of Basic Medical Sciences, Shenzhen University Health Sciences Center, Shenzhen, Guangdong, China
| | - Huazhang Zhu
- Department of Physiology, School of Basic Medical Sciences, Shenzhen University Health Sciences Center, Shenzhen, Guangdong, China
| | - Xiaoyan Huang
- Department of Physiology, School of Basic Medical Sciences, Shenzhen University Health Sciences Center, Shenzhen, Guangdong, China
| | - Yangfan Yang
- State Key Laboratory of Ophthalmology, Zhongshan Ophthalmic Center, Sun Yat-Sen University, Guangzhou, Guangdong, China
| | - Dandan Wang
- Department of Physiology, School of Basic Medical Sciences, Shenzhen University Health Sciences Center, Shenzhen, Guangdong, China.,Department of Medicine, Li Ka Shing Faculty of Medicine, The University of Hong Kong, Pokfulam, Hong Kong, China
| | - Yiling Zhang
- Department of Physiology, School of Basic Medical Sciences, Shenzhen University Health Sciences Center, Shenzhen, Guangdong, China
| | - Weizhen Zhang
- Department of Physiology and Pathophysiology, Peking University Health Science Center, Beijing, China
| | - Ying Ying
- Department of Physiology, School of Basic Medical Sciences, Shenzhen University Health Sciences Center, Shenzhen, Guangdong, China
| |
Collapse
|
9
|
Muñoz VR, Gaspar RC, Esteca MV, Baptista IL, Vieira RFL, da Silva ASR, de Moura LP, Cintra DE, Ropelle ER, Pauli JR. Physical exercise increases ROCK activity in the skeletal muscle of middle-aged rats. Mech Ageing Dev 2020; 186:111213. [PMID: 32032622 DOI: 10.1016/j.mad.2020.111213] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/27/2019] [Revised: 01/17/2020] [Accepted: 01/30/2020] [Indexed: 12/23/2022]
Abstract
The physical exercise is a potential strategy to control age-related metabolic disorders, such as insulin resistance, impaired glucose homeostasis, and type 2 diabetes. Rho-kinase (ROCK) increases skeletal muscle glucose uptake through Insulin Receptor Substrate 1 (IRS1) phosphorylation. Here, we investigated the role of physical exercise in ROCK pathway in the skeletal muscle of Fischer middle-aged rats. Firstly, we observed the ROCK distribution in different skeletal muscle fiber types. ROCK signaling pathway (ROCK1 and ROCK2) and activity (pMYPT1) were higher in the soleus, which was associated with increased insulin signaling pathway (pIR, pIRS1, pPDK, pGSK3β). Middle-aged rats submitted to physical exercise, showed the upregulation of ROCK2 content and normalized RhoA (ROCK activator enzyme) levels in soleus muscle compared with middle-aged sedentary rats. These molecular changes in middle-aged exercised rats were accompanied by higher insulin signaling (pIRS1, pGSK3β, pAS160, GLUT4) in the soleus muscle. Reinforcing these findings, when pharmacological inhibition of ROCK activity was performed (using Y-27632), the insulin signaling pathway and glucose metabolism-related genes (Tpi, Pgk1, Pgam2, Eno3) were decreased in the soleus muscle of exercised rats. In summary, ROCK signaling seems to contribute with whole-body glucose homeostasis (∼50 %) through its higher upregulation in the soleus muscle in middle-aged exercised rats.
Collapse
Affiliation(s)
- Vitor Rosetto Muñoz
- Laboratory of Molecular Biology of Exercise, University of Campinas (UNICAMP), Limeira, São Paulo, Brazil
| | - Rafael Calais Gaspar
- Laboratory of Molecular Biology of Exercise, University of Campinas (UNICAMP), Limeira, São Paulo, Brazil
| | - Marcos Vinicius Esteca
- Laboratory of Cellular and Tissue Biology, Faculty of Applied Sciences, University of Campinas (UNICAMP), Limeira, Brazil
| | - Igor Luchini Baptista
- Laboratory of Cellular and Tissue Biology, Faculty of Applied Sciences, University of Campinas (UNICAMP), Limeira, Brazil
| | - Renan Fudoli Lins Vieira
- Laboratory of Molecular Biology of Exercise, University of Campinas (UNICAMP), Limeira, São Paulo, Brazil
| | - Adelino Sanchez Ramos da Silva
- Postgraduate Program in Rehabilitation and Functional Performance, Ribeirão Preto Medical School, University of São Paulo (USP), Ribeirão Preto, São Paulo, Brazil; School of Physical Education and Sport of Ribeirão Preto, University of São Paulo (USP), Ribeirão Preto, São Paulo, Brazil
| | - Leandro Pereira de Moura
- Laboratory of Molecular Biology of Exercise, University of Campinas (UNICAMP), Limeira, São Paulo, Brazil; OCRC - Obesity and Comorbidities Research Center, University of Campinas (UNICAMP), Campinas, São Paulo, Brazil
| | - Dennys Esper Cintra
- School of Physical Education and Sport of Ribeirão Preto, University of São Paulo (USP), Ribeirão Preto, São Paulo, Brazil; Laboratory of Nutritional Genomics, University of Campinas (UNICAMP), Limeira, São Paulo, Brazil
| | - Eduardo Rochete Ropelle
- Laboratory of Molecular Biology of Exercise, University of Campinas (UNICAMP), Limeira, São Paulo, Brazil; OCRC - Obesity and Comorbidities Research Center, University of Campinas (UNICAMP), Campinas, São Paulo, Brazil
| | - José Rodrigo Pauli
- Laboratory of Molecular Biology of Exercise, University of Campinas (UNICAMP), Limeira, São Paulo, Brazil; OCRC - Obesity and Comorbidities Research Center, University of Campinas (UNICAMP), Campinas, São Paulo, Brazil.
| |
Collapse
|
10
|
Eizadi M, Mirakhori Z, Farajtabar Behrestaq S. Effect of 8-Week Interval Training on Protein Tyrosine Phosphatase 1B Expression in Gastrocnemius Muscle and Insulin Resistance in Rats with Type 2 Diabetes. AVICENNA JOURNAL OF MEDICAL BIOCHEMISTRY 2019. [DOI: 10.34172/ajmb.2019.09] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022] Open
Abstract
Background: Insulin resistance induced by genetic and metabolic disorders is the main cause of the prevalence or severity of type 2 diabetes (T2D). Protein tyrosine phosphatase 1B (PTP1B) plays a key role in regulating glucose homeostasis as a negative regulator of insulin signaling pathway. Objectives: This study aimed to assess the effect of interval training on PTP1B expression in gastrocnemius muscle and insulin resistance in male rats with T2D. Methods: T2D was induced by high fat diet (HFD) and intraperitoneal injection of STZ in 14 male Wistar rats and then they were divided randomly into exercise (n=7) or control (n=7) groups. Exercise rats completed an 8 weeks interval training (5 days/week) and control rats remained without training. Fasting glucose, serum insulin, and PTP1B expression in gastrocnemius muscle were measured 48 hours after the last exercise session. Insulin resistance was assessed using homeostasis model assessment of insulin resistance (HOMA-IR) formula based on fasting insulin and glucose levels. An independent t test was used to compare each parameter between 2 groups. A P value less than 0.05 was considered statistically significant. Results: Interval training resulted in a significant decrease in fasting glucose level (P<0.0001) and insulin resistance (P=0.018) as well as an increase in serum insulin level (P<0.0001). PTP1B expression in gastrocnemius muscle decreased significantly compared with control rats (P=0.003) Conclusion: Interval training can improve insulin resistance in T2D rats. This improvement may be attributed to the decrease in PTP1B expression in gastrocnemius muscle by interval training.
Collapse
Affiliation(s)
- Mojtaba Eizadi
- Assistant Professor of Exercise Physiology, Saveh Branch, Islamic Azad University, Saveh, Iran
| | - Zahra Mirakhori
- Assistant Professor of Physical Education and Sports Sciences, Amirkabir University of Technology, Tehran, Iran
| | | |
Collapse
|
11
|
Cano M, Guerrero-Castilla A, Nabavi SM, Ayala A, Argüelles S. Targeting pro-senescence mitogen activated protein kinase (Mapk) enzymes with bioactive natural compounds. Food Chem Toxicol 2019; 131:110544. [PMID: 31201898 DOI: 10.1016/j.fct.2019.05.052] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/30/2019] [Revised: 05/14/2019] [Accepted: 05/29/2019] [Indexed: 12/13/2022]
Abstract
Aging is a multifactorial universal process characterized by a gradual decrease in physiological and biochemical functions. Given that life expectancy is on the rise, a better understanding of molecular mechanisms of the aging process is necessary in order to develop anti-aging interventions. Uncontrolled cellular senescence promotes persistent inflammation and accelerates the aging process by decreasing tissue renewal, repair and regeneration. Senescence of immune cells, immunesenescence, is another hallmark of aging. Targeting pro-senescent enzymes increases survival and therefore the lifespan. Although the upregulation of Mitogen Activated Protein Kinases (MAPK) enzymes in aging is still controversial, increasing evidence shows that dysregulation of those enzymes are associated with biological processes that contribute to aging such as irreversible senescence. In this manuscript components of the MAPK pathway will be summarized, including extracellular signal-regulated kinase 1 and 2 (ERK1/2), c-Jun N-terminal kinase (JNK) and p38, as well as natural flavonoids, phenolic and diterpenoids with anti-senescence activity that shows positive effects on longevity and MAPK inhibition. Although more studies using additional aging models are needed, we suggest that these selected natural bioactive compounds that regulate MAPK enzymes and reduce senescent cells can be potentially used to improve longevity and prevent/treat age-related diseases.
Collapse
Affiliation(s)
- Mercedes Cano
- Department of Physiology, Faculty of Pharmacy, University of Seville, Seville, Spain
| | | | - Seyed Mohammad Nabavi
- Applied Biotechnology Research Center, Baqiyatallah University of Medical Sciences, Tehran, Iran
| | - Antonio Ayala
- Department of Biochemical and Molecular Biology, Faculty of Pharmacy, University of Seville, Seville, Spain
| | - Sandro Argüelles
- Department of Physiology, Faculty of Pharmacy, University of Seville, Seville, Spain.
| |
Collapse
|
12
|
Stanisic J, Koricanac G, Kostic M, Stojiljkovic M, Culafic T, Romic S, Tepavcevic S. Low-intensity exercise in the prevention of cardiac insulin resistance-related inflammation and disturbances in NOS and MMP-9 regulation in fructose-fed ovariectomized rats. Appl Physiol Nutr Metab 2019; 44:1219-1229. [PMID: 30897341 DOI: 10.1139/apnm-2018-0785] [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] [Indexed: 12/25/2022]
Abstract
Exercise is important nonpharmacological treatment for improvement of insulin sensitivity in menopause. However, its effect on menopausal cardiac insulin resistance is needing further research. We investigated protective effects of low-intensity exercise on cardiac insulin signaling, inflammation, regulation of nitric oxide synthase (NOS) and matrix metalloproteinase 9 (MMP-9) in ovariectomized (OVX) Wistar rats, submitted to 10% fructose solution for 9 weeks. OVX rats were divided into control, sedentary fructose, and exercise fructose groups. Measurements of physical and biochemical characteristics were carried out to evaluate metabolic syndrome development. Messenger RNA and protein levels and phosphorylation of cardiac insulin signaling molecules, endothelial and inducible NOS (eNOS and iNOS), p65 subunit of nuclear factor κB (NFκB), tumor necrosis factor α (TNF-α), suppressor of cytokine signaling 3 (SOCS3), and MMP-9 were analyzed. Fructose increased insulin level, homeostasis model assessment (HOMA) index, and visceral adipose tissue weight, while low-intensity exercise prevented insulin level and HOMA index increase. Fructose also decreased cardiac pAkt (Ser473), peNOS (Ser1177) and increased insulin receptor substrate 1 (IRS1) phosphorylation at Ser307, pNFκB (Ser276) and NFκB and MMP-9 content, without any effect on iNOS, protein-tyrosine phosphatase 1B, TNF-α, and SOCS3. Exercise prevented changes in pIRS1 (Ser307), pAkt (Ser473), peNOS (Ser1177), pNFκB (Ser276), and NFκB expression. In addition, exercise increased pIRS1 (Tyr632), pAkt (Thr308), and eNOS expression. Low-intensity exercise prevented cardiac insulin signaling disarrangement in fructose-fed OVX rats and therefore eNOS dysfunction, as well as pro-inflammatory signaling activation, without effect on tissue remodeling, suggesting physical training as a way to reduce cardiovascular risk.
Collapse
Affiliation(s)
- Jelena Stanisic
- Laboratory for Molecular Biology and Endocrinology, Vinca Institute of Nuclear Sciences, University of Belgrade, Belgrade, Republic of Serbia.,Laboratory for Molecular Biology and Endocrinology, Vinca Institute of Nuclear Sciences, University of Belgrade, Belgrade, Republic of Serbia
| | - Goran Koricanac
- Laboratory for Molecular Biology and Endocrinology, Vinca Institute of Nuclear Sciences, University of Belgrade, Belgrade, Republic of Serbia.,Laboratory for Molecular Biology and Endocrinology, Vinca Institute of Nuclear Sciences, University of Belgrade, Belgrade, Republic of Serbia
| | - Milan Kostic
- Laboratory for Molecular Biology and Endocrinology, Vinca Institute of Nuclear Sciences, University of Belgrade, Belgrade, Republic of Serbia.,Laboratory for Molecular Biology and Endocrinology, Vinca Institute of Nuclear Sciences, University of Belgrade, Belgrade, Republic of Serbia
| | - Mojca Stojiljkovic
- Laboratory for Molecular Biology and Endocrinology, Vinca Institute of Nuclear Sciences, University of Belgrade, Belgrade, Republic of Serbia.,Laboratory for Molecular Biology and Endocrinology, Vinca Institute of Nuclear Sciences, University of Belgrade, Belgrade, Republic of Serbia
| | - Tijana Culafic
- Laboratory for Molecular Biology and Endocrinology, Vinca Institute of Nuclear Sciences, University of Belgrade, Belgrade, Republic of Serbia.,Laboratory for Molecular Biology and Endocrinology, Vinca Institute of Nuclear Sciences, University of Belgrade, Belgrade, Republic of Serbia
| | - Snjezana Romic
- Laboratory for Molecular Biology and Endocrinology, Vinca Institute of Nuclear Sciences, University of Belgrade, Belgrade, Republic of Serbia.,Laboratory for Molecular Biology and Endocrinology, Vinca Institute of Nuclear Sciences, University of Belgrade, Belgrade, Republic of Serbia
| | - Snezana Tepavcevic
- Laboratory for Molecular Biology and Endocrinology, Vinca Institute of Nuclear Sciences, University of Belgrade, Belgrade, Republic of Serbia.,Laboratory for Molecular Biology and Endocrinology, Vinca Institute of Nuclear Sciences, University of Belgrade, Belgrade, Republic of Serbia
| |
Collapse
|
13
|
Canciglieri PH, Kuga GK, Muñoz VR, Gaspar RC, da Rocha AL, Breda L, Anaruma CP, Minuzzi LG, da Silva ASR, Cintra DE, de Moura LP, Ropelle ER, Pauli JR. The reversal effect of physical exercise on aging-related increases in APPL2 content in skeletal muscle. Life Sci 2018; 210:209-213. [PMID: 30189216 DOI: 10.1016/j.lfs.2018.09.006] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/28/2018] [Revised: 08/14/2018] [Accepted: 09/02/2018] [Indexed: 01/27/2023]
Abstract
AIMS The aim of this study was to evaluate the effects of aging on intracellular adiponectin signaling and the possible therapeutic effect of physical exercise. MAIN METHODS Fischer 344 rats were distributed in the following groups: Young (3 months old); Sedentary Old (Old, 27 months old); and Old Exercised (Old-Exe, 27 months old), which were subjected to a short-term exercise training protocol. KEY FINDINGS The results showed that the old rats presented glucose intolerance without increased adiposity. However, short-term exercise training reversed this disorder, which was associated with a decrease in the pleckstrin homology domain, phosphotyrosine-binding domain, and leucine zipper motif (APPL) isoform 2 (APPL2) content. The APPL isoform 1 (APPL1) and TRB3 (Tribbles homolog 3) contents were not altered. Akt phosphorylation was only increased in the old exercised rats. There was a reduction in the content of adiponectin receptor 1 in the old rats. SIGNIFICANCE The short-term exercise training protocol was able to decrease APPL2 content in the skeletal muscle, which was accompanied by an improvement in the glucose tolerance of the old Fischer 344 rats. These findings provide new evidence supporting the role of physical exercise as a non-pharmacological therapeutic intervention to attenuate age-related deficits.
Collapse
Affiliation(s)
- Paulo Henrique Canciglieri
- Laboratory of Molecular Biology of Exercise (LaBMEx), School of Applied Sciences, University of Campinas (UNICAMP), Limeira, SP, Brazil
| | - Gabriel Keine Kuga
- Post-graduate Program in Movement Sciences, São Paulo State University (UNESP), Rio Claro, SP, Brazil
| | - Vitor Rosetto Muñoz
- Laboratory of Molecular Biology of Exercise (LaBMEx), School of Applied Sciences, University of Campinas (UNICAMP), Limeira, SP, Brazil
| | - Rafael Calais Gaspar
- Laboratory of Molecular Biology of Exercise (LaBMEx), School of Applied Sciences, University of Campinas (UNICAMP), Limeira, SP, Brazil
| | - Alisson Luiz da Rocha
- School of Physical Education and Sport of Ribeirao Preto, University of Sao Paulo, Ribeirao Preto, SP, Brazil
| | - Leonardo Breda
- Laboratory of Molecular Biology of Exercise (LaBMEx), School of Applied Sciences, University of Campinas (UNICAMP), Limeira, SP, Brazil
| | - Chadi Pellegrini Anaruma
- Post-graduate Program in Movement Sciences, São Paulo State University (UNESP), Rio Claro, SP, Brazil
| | - Luciele Guerra Minuzzi
- Laboratory of Molecular Biology of Exercise (LaBMEx), School of Applied Sciences, University of Campinas (UNICAMP), Limeira, SP, Brazil
| | | | - Dennys Esper Cintra
- Laboratory of Nutritional Genomics (LabGeN), School of Applied Sciences, University of Campinas (UNICAMP), Limeira, SP, Brazil; Laboratory of Cell Signaling, Obesity and Comorbidities Research Center (OCRC), University of Campinas, Campinas, SP, Brazil
| | - Leandro Pereira de Moura
- Laboratory of Molecular Biology of Exercise (LaBMEx), School of Applied Sciences, University of Campinas (UNICAMP), Limeira, SP, Brazil; Post-graduate Program in Movement Sciences, São Paulo State University (UNESP), Rio Claro, SP, Brazil; Laboratory of Cell Signaling, Obesity and Comorbidities Research Center (OCRC), University of Campinas, Campinas, SP, Brazil; CEPECE - Center of Research in Sport Sciences, School of Applied Sciences, University of Campinas (UNICAMP), Limeira, SP, Brazil
| | - Eduardo Rochete Ropelle
- Laboratory of Molecular Biology of Exercise (LaBMEx), School of Applied Sciences, University of Campinas (UNICAMP), Limeira, SP, Brazil; Laboratory of Cell Signaling, Obesity and Comorbidities Research Center (OCRC), University of Campinas, Campinas, SP, Brazil; CEPECE - Center of Research in Sport Sciences, School of Applied Sciences, University of Campinas (UNICAMP), Limeira, SP, Brazil
| | - José Rodrigo Pauli
- Laboratory of Molecular Biology of Exercise (LaBMEx), School of Applied Sciences, University of Campinas (UNICAMP), Limeira, SP, Brazil; Laboratory of Cell Signaling, Obesity and Comorbidities Research Center (OCRC), University of Campinas, Campinas, SP, Brazil; CEPECE - Center of Research in Sport Sciences, School of Applied Sciences, University of Campinas (UNICAMP), Limeira, SP, Brazil.
| |
Collapse
|
14
|
|
15
|
Fructose Consumption in the Development of Obesity and the Effects of Different Protocols of Physical Exercise on the Hepatic Metabolism. Nutrients 2017; 9:nu9040405. [PMID: 28425939 PMCID: PMC5409744 DOI: 10.3390/nu9040405] [Citation(s) in RCA: 66] [Impact Index Per Article: 9.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/27/2017] [Revised: 04/03/2017] [Accepted: 04/06/2017] [Indexed: 02/07/2023] Open
Abstract
Fructose consumption has been growing exponentially and, concomitant with this, the increase in the incidence of obesity and associated complications has followed the same behavior. Studies indicate that fructose may be a carbohydrate with greater obesogenic potential than other sugars. In this context, the liver seems to be a key organ for understanding the deleterious health effects promoted by fructose consumption. Fructose promotes complications in glucose metabolism, accumulation of triacylglycerol in the hepatocytes, and alterations in the lipid profile, which, associated with an inflammatory response and alterations in the redox state, will imply a systemic picture of insulin resistance. However, physical exercise has been indicated for the treatment of several chronic diseases. In this review, we show how each exercise protocol (aerobic, strength, or a combination of both) promote improvements in the obesogenic state created by fructose consumption as an improvement in the serum and liver lipid profile (high-density lipoprotein (HDL) increase and decrease triglyceride (TG) and low-density lipoprotein (LDL) levels) and a reduction of markers of inflammation caused by an excess of fructose. Therefore, it is concluded that the practice of aerobic physical exercise, strength training, or a combination of both is essential for attenuating the complications developed by the consumption of fructose.
Collapse
|
16
|
Pereira BC, da Rocha AL, Pinto AP, Pauli JR, de Moura LP, Mekary RA, de Freitas EC, da Silva ASR. Excessive training impairs the insulin signal transduction in mice skeletal muscles. J Endocrinol 2016; 230:93-104. [PMID: 27189188 DOI: 10.1530/joe-16-0063] [Citation(s) in RCA: 16] [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: 05/03/2016] [Accepted: 05/17/2016] [Indexed: 12/14/2022]
Abstract
The main aim of this investigation was to verify the effects of overtraining (OT) on the insulin and inflammatory signaling pathways in mice skeletal muscles. Rodents were divided into control (CT), overtrained by downhill running (OTR/down), overtrained by uphill running (OTR/up), and overtrained by running without inclination (OTR) groups. Rotarod, incremental load, exhaustive, and grip force tests were used to evaluate performance. Thirty-six hours after the grip force test, the extensor digitorum longus (EDL) and soleus were extracted for subsequent protein analyses. The three OT protocols led to similar responses of all performance evaluation tests. The phosphorylation of insulin receptor beta (pIRβ; Tyr), protein kinase B (pAkt; Ser473), and the protein levels of plasma membrane glucose transporter-4 (GLUT4) were lower in the EDL and soleus after the OTR/down protocol and in the soleus after the OTR/up and OTR protocols. While the pIRβ was lower after the OTR/up and OTR protocols, the pAkt was higher after the OTR/up in the EDL. The phosphorylation of IκB kinase alpha and beta (pIKKα/β; Ser180/181), stress-activated protein kinases/Jun amino-terminal kinases (pSAPK-JNK; Thr183/Tyr185), factor nuclear kappa B (pNFκB p65; Ser536), and insulin receptor substrate 1 (pIRS1; Ser307) were higher after the OTR/down protocol, but were not altered after the two other OT protocols. In summary, these data suggest that OT may lead to skeletal muscle insulin signaling pathway impairment, regardless of the predominance of eccentric contractions, although the insulin signal pathway impairment induced in OTR/up and OTR appeared to be muscle fiber-type specific.
Collapse
Affiliation(s)
- Bruno C Pereira
- Postgraduate Program in Rehabilitation and Functional PerformanceRibeirão Preto Medical School, USP, Ribeirão Preto, São Paulo, Brazil
| | - Alisson L da Rocha
- Postgraduate Program in Rehabilitation and Functional PerformanceRibeirão Preto Medical School, USP, Ribeirão Preto, São Paulo, Brazil
| | - Ana P Pinto
- Postgraduate Program in Rehabilitation and Functional PerformanceRibeirão Preto Medical School, USP, Ribeirão Preto, São Paulo, Brazil
| | - José R Pauli
- Sport Sciences CourseFaculty of Applied Sciences, State University of Campinas, Limeira, São Paulo, Brazil
| | - Leandro P de Moura
- Sport Sciences CourseFaculty of Applied Sciences, State University of Campinas, Limeira, São Paulo, Brazil
| | - Rania A Mekary
- Department of NutritionHarvard School of Public Health, Boston, Massachusetts, USA Department of Social and Administrative SciencesMCPHS University, Boston, Massachusetts, USA
| | - Ellen C de Freitas
- School of Physical Education and Sport of Ribeirão PretoUniversity of São Paulo, Ribeirão Preto, São Paulo, Brazil
| | - Adelino S R da Silva
- Postgraduate Program in Rehabilitation and Functional PerformanceRibeirão Preto Medical School, USP, Ribeirão Preto, São Paulo, Brazil School of Physical Education and Sport of Ribeirão PretoUniversity of São Paulo, Ribeirão Preto, São Paulo, Brazil
| |
Collapse
|
17
|
Exercise Promotes Healthy Aging of Skeletal Muscle. Cell Metab 2016; 23:1034-1047. [PMID: 27304505 PMCID: PMC5045036 DOI: 10.1016/j.cmet.2016.05.007] [Citation(s) in RCA: 292] [Impact Index Per Article: 36.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/15/2016] [Revised: 05/18/2016] [Accepted: 05/24/2016] [Indexed: 02/08/2023]
Abstract
Primary aging is the progressive and inevitable process of bodily deterioration during adulthood. In skeletal muscle, primary aging causes defective mitochondrial energetics and reduced muscle mass. Secondary aging refers to additional deleterious structural and functional age-related changes caused by diseases and lifestyle factors. Secondary aging can exacerbate deficits in mitochondrial function and muscle mass, concomitant with the development of skeletal muscle insulin resistance. Exercise opposes deleterious effects of secondary aging by preventing the decline in mitochondrial respiration, mitigating aging-related loss of muscle mass and enhancing insulin sensitivity. This review focuses on mechanisms by which exercise promotes "healthy aging" by inducing modifications in skeletal muscle.
Collapse
|
18
|
Ghosh S, Lertwattanarak R, Garduño JDJ, Galeana JJ, Li J, Zamarripa F, Lancaster JL, Mohan S, Hussey S, Musi N. Elevated muscle TLR4 expression and metabolic endotoxemia in human aging. J Gerontol A Biol Sci Med Sci 2015; 70:232-46. [PMID: 24846769 PMCID: PMC4311182 DOI: 10.1093/gerona/glu067] [Citation(s) in RCA: 99] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/10/2013] [Accepted: 04/07/2014] [Indexed: 12/25/2022] Open
Abstract
Aging is associated with alterations in glucose metabolism and sarcopenia that jointly contribute to a higher risk of developing type 2 diabetes. Because aging is considered as a state of low-grade inflammation, in this study we examined whether older, healthy (lean, community-dwelling) participants have altered signaling flux through toll-like receptor 4 (TLR4), a key mediator of innate and adaptive immune responses. We also examined whether a 4-month aerobic exercise program would have an anti-inflammatory effect by reducing TLR4 expression and signaling. At baseline, muscle TLR4, nuclear factor κB p50 and nuclear factor κB p65 protein content, and c-Jun N-terminal kinase phosphorylation were significantly elevated in older versus young participants. The plasma concentration of the TLR4 agonist lipopolysaccharide and its binding protein also were significantly elevated in older participants, indicative of metabolic endotoxemia, which is a recently described phenomenon of increased plasma endotoxin level in metabolic disease. These alterations in older participants were accompanied by decreased insulin sensitivity, quadriceps muscle volume, and muscle strength. The exercise training program increased insulin sensitivity, without affecting quadriceps muscle volume or strength. Muscle TLR4, nuclear factor κB, and c-Jun N-terminal kinase, and plasma lipopolysaccharide and lipopolysaccharide binding protein were not changed by exercise. In conclusion, insulin resistance and sarcopenia of aging are associated with increased TLR4 expression/signaling, which may be secondary to metabolic endotoxemia.
Collapse
Affiliation(s)
- Sangeeta Ghosh
- Geriatric Research, Education and Clinical Center, Audie L. Murphy VA Hospital, South Texas Veterans Health Care System, San Antonio. Barshop Institute for Longevity and Aging Studies, Center for Healthy Aging
| | | | | | | | | | | | | | - Sumathy Mohan
- Department of Pathology, University of Texas Health Science Center, San Antonio
| | - Sophie Hussey
- Geriatric Research, Education and Clinical Center, Audie L. Murphy VA Hospital, South Texas Veterans Health Care System, San Antonio. Barshop Institute for Longevity and Aging Studies, Center for Healthy Aging
| | - Nicolas Musi
- Geriatric Research, Education and Clinical Center, Audie L. Murphy VA Hospital, South Texas Veterans Health Care System, San Antonio. Barshop Institute for Longevity and Aging Studies, Center for Healthy Aging,
| |
Collapse
|
19
|
Pereira BC, Pauli JR, De Souza CT, Ropelle ER, Cintra DE, Freitas EC, da Silva ASR. Eccentric exercise leads to performance decrease and insulin signaling impairment. Med Sci Sports Exerc 2015; 46:686-94. [PMID: 24002347 DOI: 10.1249/mss.0000000000000149] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Abstract
PURPOSE This study aimed to evaluate the effects of an overtraining (OT) protocol based on eccentric exercise (EE) sessions on the insulin and inflammatory signaling pathways in the skeletal muscles of Swiss mice. METHODS Rodents were divided into control (C; sedentary mice), trained (TR; performed the aerobic training protocol), and overtrained (OTR; performed the OT protocol). The incremental load test and exhaustive test were used to measure performances before and after exercise protocols. Twenty-four hours after the exhaustive test performed at the end of week 8, the extensor digitorum longus (EDL) and soleus muscles were removed for subsequent protein analysis by immunoblotting. RESULTS The phosphorylation of insulin receptor beta (pIRbeta; Tyr1146) diminished for EDL and soleus muscles in OTR compared with C. The phosphorylation of insulin receptor substrate 1 (pIRS-1; Ser307) increased for EDL and soleus muscles in OTR compared with C and TR. The phosphorylation of protein kinase B (pAkt; Ser473) diminished for EDL and soleus muscles in OTR compared with C and TR. The phosphorylation of IκB kinase alpha and beta (pIKKalpha/beta; Ser176/180), stress-activated protein kinases/Jun amino-terminal kinases (pSAPK/JNK; Thr183/Tyr185), and the protein levels of suppressor of cytokine signaling 3 (SOCS3) increased for EDL and soleus muscles in OTR compared with C and TR. CONCLUSION In summary, the current used OT protocol based on eccentric exercise sessions impaired the insulin signaling pathway with concomitant increases of IKK, SAPK/JNK, and SOCS3 protein levels.
Collapse
Affiliation(s)
- Bruno C Pereira
- 1School of Physical Education and Sport of Ribeirão Preto, University of São Paulo, Ribeirão Preto, São Paulo, BRAZIL; 2Sport Sciences Course, Faculty of Applied Sciences, State University of Campinas, Limeira, São Paulo, BRAZIL; and 3Exercise Biochemistry and Physiology Laboratory Postgraduate Program in Health Sciences, Health Sciences Unit, University of Southern Santa Catarina, Criciuma, Santa Catarina, BRAZIL
| | | | | | | | | | | | | |
Collapse
|
20
|
Khadir A, Tiss A, Abubaker J, Abu-Farha M, Al-Khairi I, Cherian P, John J, Kavalakatt S, Warsame S, Al-Madhoun A, Al-Ghimlas F, Elkum N, Behbehani K, Dermime S, Dehbi M. MAP kinase phosphatase DUSP1 is overexpressed in obese humans and modulated by physical exercise. Am J Physiol Endocrinol Metab 2015; 308:E71-83. [PMID: 25370852 DOI: 10.1152/ajpendo.00577.2013] [Citation(s) in RCA: 39] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
Chronic low-grade inflammation and dysregulation of the stress defense system are cardinal features of obesity, a major risk factor for the development of insulin resistance and diabetes. Dual-specificity protein phosphatase 1 (DUSP1), known also as MAP kinase phosphatase 1 (MKP1), is implicated in metabolism and energy expenditure. Mice lacking DUSP1 are resistant to high-fat diet-induced obesity. However, the expression of DUSP1 has not been investigated in human obesity. In the current study, we compared the expression pattern of DUSP1 between lean and obese nondiabetic human subjects using subcutaneous adipose tissue (SAT) and peripheral blood mononuclear cells (PBMCs). The levels of DUSP1 mRNA and protein were significantly increased in obese subjects with concomitant decrease in the phosphorylation of p38 MAPK (p-p38 MAPK) and PGC-1α and an increase in the levels of phospho-JNK (p-JNK) and phospho-ERK (p-ERK). Moreover, obese subjects had higher levels of circulating DUSP1 protein that correlated positively with various obesity indicators, triglycerides, glucagon, insulin, leptin, and PAI-1 (P < 0.05) but negatively with V̇O(2max) and high-density lipoprotein (P < 0.05). The observation that DUSP1 was overexpressed in obese subjects prompted us to investigate whether physical exercise could reduce its expression. In this study, we report for the first time that physical exercise significantly attenuated the expression of DUSP1 in both the SAT and PBMCs, with a parallel increase in the expression of PGC-1α and a reduction in the levels of p-JNK and p-ERK along with attenuated inflammatory response. Collectively, our data suggest that DUSP1 upregulation is strongly linked to adiposity and that physical exercise modulates its expression. This gives further evidence that exercise might be useful as a strategy for managing obesity and preventing its associated complications.
Collapse
Affiliation(s)
| | - Ali Tiss
- Deptartment of Biomedical Research
| | | | | | | | | | | | | | | | | | | | - Naser Elkum
- Department of Biostatistics and Epidemiology, Dasman Diabetes Institute, Kuwait City, Kuwait
| | - Kazem Behbehani
- Deptartment of Biomedical Research, Fitness and Rehabilitation Center, and Department of Biostatistics and Epidemiology, Dasman Diabetes Institute, Kuwait City, Kuwait
| | - Said Dermime
- King Fahad Specialist Hospital, Dammam, Saudi Arabia; and
| | - Mohammed Dehbi
- Diabetes Research Centre, Qatar Biomedical Research Institute, Qatar Foundation, Doha, Qatar
| |
Collapse
|
21
|
Castorena CM, Arias EB, Sharma N, Cartee GD. Effects of a brief high-fat diet and acute exercise on the mTORC1 and IKK/NF-κB pathways in rat skeletal muscle. Appl Physiol Nutr Metab 2014; 40:251-62. [PMID: 25706655 DOI: 10.1139/apnm-2014-0412] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Abstract
One exercise session can improve subsequent insulin-stimulated glucose uptake by skeletal muscle in healthy and insulin-resistant individuals. Our first aim was to determine whether a brief (2 weeks) high-fat diet (HFD) that caused muscle insulin resistance would activate the mammalian target of rapamycin complex 1 (mTORC1) and/or inhibitor of κB kinase/nuclear factor κB (IKK/NF-κB) pathways, which are potentially linked to induction of insulin resistance. Our second aim was to determine whether acute exercise that improved insulin-stimulated glucose uptake by muscles would attenuate activation of these pathways. We compared HFD-fed rats with rats fed a low-fat diet (LFD). Some animals from each diet group were sedentary and others were studied 3 h postexercise, when insulin-stimulated glucose uptake was increased. The results did not provide evidence that brief HFD activated either the mTORC1 (including phosphorylation of mTOR(Ser2448), TSC2(Ser939), p70S6K(Thr412), and RPS6(Ser235/236)) or the IKK/NF-κB (including abundance of IκBα or phosphorylation of NF-κB(Ser536), IKKα/β(Ser177/181), and IκB(Ser32)) pathway in insulin-resistant muscles. Exercise did not oppose the activation of either pathway, as evidenced by no attenuation of phosphorylation of key proteins in the IKK/NF-κB pathway (NF-κB(Ser536), IKKα/β(Ser177/181), and IκB(Ser32)), unaltered IκBα abundance, and no attenuation of phosphorylation of key proteins in the mTORC1 pathway (mTOR(Ser2448), TSC2(Ser939), and RPS6(Ser235/236)). Instead, exercise induced greater phosphorylation of 2 proteins of the mTORC1 pathway (PRAS40(Thr246) and p70S6K(Thr412)) in insulin-stimulated muscles, regardless of diet. Insulin resistance induced by a brief HFD was not attributable to greater activation of the mTORC1 or the IKK/NF-κB pathway in muscle, and exercise-induced improvement in insulin sensitivity was not attributable to attenuated activation of these pathways in muscle.
Collapse
Affiliation(s)
- Carlos M Castorena
- Muscle Biology Laboratory, School of Kinesiology, University of Michigan, Ann Arbor, MI 48109-2214, USA
| | | | | | | |
Collapse
|
22
|
Hooper PL, Balogh G, Rivas E, Kavanagh K, Vigh L. The importance of the cellular stress response in the pathogenesis and treatment of type 2 diabetes. Cell Stress Chaperones 2014; 19:447-64. [PMID: 24523032 PMCID: PMC4041942 DOI: 10.1007/s12192-014-0493-8] [Citation(s) in RCA: 79] [Impact Index Per Article: 7.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/11/2013] [Revised: 12/24/2013] [Accepted: 01/02/2014] [Indexed: 01/06/2023] Open
Abstract
Organisms have evolved to survive rigorous environments and are not prepared to thrive in a world of caloric excess and sedentary behavior. A realization that physical exercise (or lack of it) plays a pivotal role in both the pathogenesis and therapy of type 2 diabetes mellitus (t2DM) has led to the provocative concept of therapeutic exercise mimetics. A decade ago, we attempted to simulate the beneficial effects of exercise by treating t2DM patients with 3 weeks of daily hyperthermia, induced by hot tub immersion. The short-term intervention had remarkable success, with a 1 % drop in HbA1, a trend toward weight loss, and improvement in diabetic neuropathic symptoms. An explanation for the beneficial effects of exercise and hyperthermia centers upon their ability to induce the cellular stress response (the heat shock response) and restore cellular homeostasis. Impaired stress response precedes major metabolic defects associated with t2DM and may be a near seminal event in the pathogenesis of the disease, tipping the balance from health into disease. Heat shock protein inducers share metabolic pathways associated with exercise with activation of AMPK, PGC1-a, and sirtuins. Diabetic therapies that induce the stress response, whether via heat, bioactive compounds, or genetic manipulation, improve or prevent all of the morbidities and comorbidities associated with the disease. The agents reduce insulin resistance, inflammatory cytokines, visceral adiposity, and body weight while increasing mitochondrial activity, normalizing membrane structure and lipid composition, and preserving organ function. Therapies restoring the stress response can re-tip the balance from disease into health and address the multifaceted defects associated with the disease.
Collapse
Affiliation(s)
- Philip L. Hooper
- />Division of Endocrinology, Metabolism and Diabetes, Department of Medicine, University of Colorado Anschutz Medical Campus, Aurora, CO USA
| | - Gabor Balogh
- />Institute of Biochemistry, Biological Research Center, Hungarian Academy of Sciences, Szeged, Hungary
| | - Eric Rivas
- />Institute for Exercise and Environmental Medicine, Texas Health Presbyterian Hospital of Dallas and University of Texas Southwestern Medical Center, Dallas, TX USA
- />Department of Kinesiology, Texas Woman’s University, Denton, TX USA
| | - Kylie Kavanagh
- />Department of Pathology, Wake Forest School of Medicine, Winston–Salem, NC USA
| | - Laszlo Vigh
- />Institute of Biochemistry, Biological Research Center, Hungarian Academy of Sciences, Szeged, Hungary
| |
Collapse
|
23
|
Fontes MT, Silva TLBT, Mota MM, Barreto AS, Rossoni LV, Santos MRV. Resistance exercise acutely enhances mesenteric artery insulin-induced relaxation in healthy rats. Life Sci 2013; 94:24-9. [PMID: 24316143 DOI: 10.1016/j.lfs.2013.11.017] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/03/2013] [Revised: 11/11/2013] [Accepted: 11/21/2013] [Indexed: 12/20/2022]
Abstract
AIMS We evaluated the mechanisms involved in insulin-induced vasodilatation after acute resistance exercise in healthy rats. MAIN METHODS Wistar rats were divided into 3 groups: control (CT), electrically stimulated (ES) and resistance exercise (RE). Immediately after acute RE (15 sets with 10 repetitions at 70% of maximal intensity), the animals were sacrificed and rings of mesenteric artery were mounted in an isometric system. After this, concentration-response curves to insulin were performed in control condition and in the presence of LY294002 (PI3K inhibitor), L-NAME (NOS inhibitor), L-NAME+TEA (K(+) channels inhibitor), LY294002+BQ123 (ET-A antagonist) or ouabain (Na(+)/K(+) ATPase inhibitor). KEY FINDINGS Acute RE increased insulin-induced vasorelaxation as compared to control (CT: Rmax=7.3 ± 0.4% and RE: Rmax=15.8 ± 0.8%; p<0.001). NOS inhibition reduced (p<0.001) this vasorelaxation from both groups (CT: Rmax=2.0 ± 0.3%, and RE: Rmax=-1.2 ± 0.1%), while PI3K inhibition abolished the vasorelaxation in CT (Rmax=-0.1±0.3%, p<0.001), and caused vasoconstriction in RE (Rmax=-6.5 ± 0.6%). That insulin-induced vasoconstriction on PI3K inhibition was abolished (p<0.001) by the ET-A antagonist (Rmax=2.9 ± 0.4%). Additionally, acute RE enhanced (p<0.001) the functional activity of the ouabain-sensitive Na(+)/K(+) ATPase activity (Rmax=10.7 ± 0.4%) and of the K(+) channels (Rmax=-6.1±0.5%; p<0.001) in the insulin-induced vasorelaxation as compared to CT. SIGNIFICANCE Such results suggest that acute RE promotes enhanced insulin-induced vasodilatation, which could act as a fine tuning to vascular tone.
Collapse
Affiliation(s)
- M T Fontes
- Department of Physiology, Federal University of Sergipe, 49100-000, São Cristóvão, SE, Brazil
| | - T L B T Silva
- Department of Physiology, Federal University of Sergipe, 49100-000, São Cristóvão, SE, Brazil
| | - M M Mota
- Department of Physiology, Federal University of Sergipe, 49100-000, São Cristóvão, SE, Brazil
| | - A S Barreto
- Department of Physiology, Federal University of Sergipe, 49100-000, São Cristóvão, SE, Brazil
| | - L V Rossoni
- Department of Physiology and Biophysics, Institute of Biomedical Sciences, University of Sao Paulo, 05508-900, São Paulo, SP, Brazil
| | - M R V Santos
- Department of Physiology, Federal University of Sergipe, 49100-000, São Cristóvão, SE, Brazil.
| |
Collapse
|
24
|
Panzhinskiy E, Ren J, Nair S. Protein tyrosine phosphatase 1B and insulin resistance: role of endoplasmic reticulum stress/reactive oxygen species/nuclear factor kappa B axis. PLoS One 2013; 8:e77228. [PMID: 24204775 PMCID: PMC3799617 DOI: 10.1371/journal.pone.0077228] [Citation(s) in RCA: 73] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/16/2013] [Accepted: 09/01/2013] [Indexed: 12/24/2022] Open
Abstract
Obesity-induced endoplasmic reticulum (ER) stress has been proposed as an important pathway in the development of insulin resistance. Protein-tyrosine phosphatase 1B (PTP1B) is a negative regulator of insulin signaling and is tethered to the ER-membrane. The aim of the study was to determine the mechanisms involved in the crosstalk between ER-stress and PTP1B. PTP1B whole body knockout and C57BL/6J mice were subjected to a high-fat or normal chow-diet for 20 weeks. High-fat diet feeding induced body weight gain, increased adiposity, systemic glucose intolerance, and hepatic steatosis were attenuated by PTP1B deletion. High-fat diet- fed PTP1B knockout mice also exhibited improved glucose uptake measured using [(3)H]-2-deoxy-glucose incorporation assay and Akt phosphorylation in the skeletal muscle tissue, compared to their wild-type control mice which received similar diet. High-fat diet-induced upregulation of glucose-regulated protein-78, phosphorylation of eukaryotic initiation factor 2α and c-Jun NH2-terminal kinase-2 were significantly attenuated in the PTP1B knockout mice. Mice lacking PTP1B showed decreased expression of the autophagy related protein p62 and the unfolded protein response adaptor protein NCK1 (non-catalytic region of tyrosine kinase). Treatment of C2C12 myotubes with the ER-stressor tunicamycin resulted in the accumulation of reactive oxygen species (ROS), leading to the activation of protein expression of PTP1B. Furthermore, tunicamycin-induced ROS production activated nuclear translocation of NFκB p65 and was required for ER stress-mediated expression of PTP1B. Our data suggest that PTP1B is induced by ER stress via the activation of the ROS-NFκB axis which is causes unfolded protein response and mediates insulin resistance in the skeletal muscle under obese condition.
Collapse
Affiliation(s)
- Evgeniy Panzhinskiy
- School of Pharmacy & Center for Cardiovascular Research and Alternative Medicine, University of Wyoming College of Health Sciences, Laramie, Wyoming, United States of America
| | - Jun Ren
- School of Pharmacy & Center for Cardiovascular Research and Alternative Medicine, University of Wyoming College of Health Sciences, Laramie, Wyoming, United States of America
| | - Sreejayan Nair
- School of Pharmacy & Center for Cardiovascular Research and Alternative Medicine, University of Wyoming College of Health Sciences, Laramie, Wyoming, United States of America
| |
Collapse
|
25
|
Chiarreotto-Ropelle EC, Pauli LSS, Katashima CK, Pimentel GD, Picardi PK, Silva VRR, de Souza CT, Prada PO, Cintra DE, Carvalheira JBC, Ropelle ER, Pauli JR. Acute exercise suppresses hypothalamic PTP1B protein level and improves insulin and leptin signaling in obese rats. Am J Physiol Endocrinol Metab 2013; 305:E649-59. [PMID: 23880311 DOI: 10.1152/ajpendo.00272.2013] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Abstract
Hypothalamic inflammation is associated with insulin and leptin resistance, hyperphagia, and obesity. In this scenario, hypothalamic protein tyrosine phosphatase 1B (PTP1B) has emerged as the key phosphatase induced by inflammation that is responsible for the central insulin and leptin resistance. Here, we demonstrated that acute exercise reduced inflammation and PTP1B protein level/activity in the hypothalamus of obese rodents. Exercise disrupted the interaction between PTP1B with proteins involved in the early steps of insulin (IRβ and IRS-1) and leptin (JAK2) signaling, increased the tyrosine phosphorylation of these molecules, and restored the anorexigenic effects of insulin and leptin in obese rats. Interestingly, the anti-inflammatory action and the reduction of PTP1B activity mediated by exercise occurred in an interleukin-6 (IL-6)-dependent manner because exercise failed to reduce inflammation and PTP1B protein level after the disruption of hypothalamic-specific IL-6 action in obese rats. Conversely, intracerebroventricular administration of recombinant IL-6 reproduced the effects of exercise, improving hypothalamic insulin and leptin action by reducing the inflammatory signaling and PTP1B activity in obese rats at rest. Taken together, our study reports that physical exercise restores insulin and leptin signaling, at least in part, by reducing hypothalamic PTP1B protein level through the central anti-inflammatory response.
Collapse
|
26
|
de Moura LP, Sponton ACDS, de Araújo MB, Dalia RA, Pauli JR, Rostom de Mello MA. Moderate physical activity from childhood contributes to metabolic health and reduces hepatic fat accumulation in adult rats. Lipids Health Dis 2013; 12:29. [PMID: 23496920 PMCID: PMC3599760 DOI: 10.1186/1476-511x-12-29] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/28/2013] [Accepted: 02/28/2013] [Indexed: 01/22/2023] Open
Abstract
BACKGROUND Obesity, oxidative stress and inflammation, by triggering insulin resistance, may contribute to the accumulation of hepatic fat, and this accumulation by lipotoxicity can lead the organ to fail. Because obesity is growing at an alarming rate and, worryingly, in a precocious way, the present study aimed to investigate the effects of moderate physical training performed from childhood to adulthood on liver fat metabolism in rats. METHODS Twenty rats that were 28 days old were divided into two groups: control (C) and trained (T). The C Group was kept in cages without exercise, and the T group was submitted to swimming exercise for 1 hour/day, 5 days/week from 28 to 90 days of age (8 weeks) at 80% of the anaerobic threshold determined by the lactate minimum test. At the end of the experiment, the body weight gain, insulin sensitivity (glucose disappearance rate during the insulin tolerance test), concentrations of free fatty acids (FFA) and triglycerides (TG) and hepatic lipogenic rate were analyzed. For the statistical analysis, the Student t-test was used with the level of significance preset at 5%. RESULTS The T group showed lower body weight gain, FFA concentrations, fat accumulation, hepatic lipogenic rate and insulin resistance. CONCLUSION The regular practice of moderate physical exercise from childhood can contribute to the reduction of obesity and insulin resistance and help prevent the development of accumulation of hepatic fat in adulthood.
Collapse
Affiliation(s)
- Leandro Pereira de Moura
- UNESP/Rio Claro, Bioscience Institute, Physical Education Department, São Paulo State University, Rio Claro, Brazil.
| | | | | | | | | | | |
Collapse
|
27
|
de Moura LP, Souza Pauli LS, Cintra DE, de Souza CT, da Silva ASR, Marinho R, de Melo MAR, Ropelle ER, Pauli JR. Acute exercise decreases PTP-1B protein level and improves insulin signaling in the liver of old rats. IMMUNITY & AGEING 2013; 10:8. [PMID: 23442260 PMCID: PMC3599175 DOI: 10.1186/1742-4933-10-8] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 11/27/2012] [Accepted: 02/20/2013] [Indexed: 11/17/2022]
Abstract
It is now commonly accepted that chronic inflammation associated with obesity during aging induces insulin resistance in the liver. In the present study, we investigated whether the improvement in insulin sensitivity and insulin signaling, mediated by acute exercise, could be associated with modulation of protein-tyrosine phosphatase 1B (PTP-1B) in the liver of old rats. Aging rats were subjected to swimming for two 1.5-h long bouts, separated by a 45 min rest period. Sixteen hours after the exercise, the rats were sacrificed and proteins from the insulin signaling pathway were analyzed by immunoblotting. Our results show that the fat mass was increased in old rats. The reduction in glucose disappearance rate (Kitt) observed in aged rats was restored 16 h after exercise. Aging increased the content of PTP-1B and attenuated insulin signaling in the liver of rats, a phenomenon that was reversed by exercise. Aging rats also increased the IRβ/PTP-1B and IRS-1/PTP-1B association in the liver when compared with young rats. Conversely, in the liver of exercised old rats, IRβ/PTP-1B and IRS-1/PTP-1B association was markedly decreased. Moreover, in the hepatic tissue of old rats, the insulin signalling was decreased and PEPCK and G6Pase levels were increased when compared with young rats. Interestingly, 16 h after acute exercise, the PEPCK and G6Pase protein level were decreased in the old exercised group. These results provide new insights into the mechanisms by which exercise restores insulin signalling in liver during aging.
Collapse
Affiliation(s)
- Leandro Pereira de Moura
- Universidade Estadual Paulista, UNESP, Curso de Pós-Graduação em Ciências da Motricidade Humana, Rio Claro, SP, Brazil
| | - Luciana Santos Souza Pauli
- Faculdade de Ciências Aplicadas, Universidade Estadual de Campinas, Curso de Pós-Graduação em Nutrição, Esporte e Metabolismo. UNICAMP, Limeira, SP, Brazil
| | - Dennys Esper Cintra
- Faculdade de Ciências Aplicadas, Universidade Estadual de Campinas, Curso de Pós-Graduação em Nutrição, Esporte e Metabolismo. UNICAMP, Limeira, SP, Brazil
| | | | | | - Rodolfo Marinho
- Faculdade de Ciências Aplicadas, Universidade Estadual de Campinas, Curso de Pós-Graduação em Nutrição, Esporte e Metabolismo. UNICAMP, Limeira, SP, Brazil
| | - Maria Alice Rostom de Melo
- Universidade Estadual Paulista, UNESP, Curso de Pós-Graduação em Ciências da Motricidade Humana, Rio Claro, SP, Brazil
| | - Eduardo Rochete Ropelle
- Faculdade de Ciências Aplicadas, Universidade Estadual de Campinas, Curso de Pós-Graduação em Nutrição, Esporte e Metabolismo. UNICAMP, Limeira, SP, Brazil
| | - José Rodrigo Pauli
- Universidade Estadual Paulista, UNESP, Curso de Pós-Graduação em Ciências da Motricidade Humana, Rio Claro, SP, Brazil.,Faculdade de Ciências Aplicadas, Universidade Estadual de Campinas, Curso de Pós-Graduação em Nutrição, Esporte e Metabolismo. UNICAMP, Limeira, SP, Brazil.,Curso de Ciências do Esporte, FCA-UNICAMP, Rua Pedro Zaccaria, 1300, Jardim Santa Luzia, Limeira, SP, Brazil
| |
Collapse
|
28
|
Colombo NH, Shirakashi DJ, Chiba FY, Sara de Lima Coutinho M, Ervolino E, Saliba Garbin CA, Machado UF, Sumida DH. Periodontal Disease Decreases Insulin Sensitivity and Insulin Signaling. J Periodontol 2012; 83:864-70. [DOI: 10.1902/jop.2011.110349] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
|
29
|
Tonkin J, Villarroya F, Puri PL, Vinciguerra M. SIRT1 signaling as potential modulator of skeletal muscle diseases. Curr Opin Pharmacol 2012; 12:372-6. [DOI: 10.1016/j.coph.2012.02.010] [Citation(s) in RCA: 35] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/23/2012] [Revised: 02/03/2012] [Accepted: 02/15/2012] [Indexed: 12/20/2022]
|
30
|
Arthur ST, Cooley ID. The effect of physiological stimuli on sarcopenia; impact of Notch and Wnt signaling on impaired aged skeletal muscle repair. Int J Biol Sci 2012; 8:731-60. [PMID: 22701343 PMCID: PMC3371570 DOI: 10.7150/ijbs.4262] [Citation(s) in RCA: 78] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/21/2012] [Accepted: 04/06/2012] [Indexed: 12/17/2022] Open
Abstract
The age-related loss of skeletal muscle mass and function that is associated with sarcopenia can result in ultimate consequences such as decreased quality of life. The causes of sarcopenia are multifactorial and include environmental and biological factors. The purpose of this review is to synthesize what the literature reveals in regards to the cellular regulation of sarcopenia, including impaired muscle regenerative capacity in the aged, and to discuss if physiological stimuli have the potential to slow the loss of myogenic potential that is associated with sarcopenia. In addition, this review article will discuss the effect of aging on Notch and Wnt signaling, and whether physiological stimuli have the ability to restore Notch and Wnt signaling resulting in rejuvenated aged muscle repair. The intention of this summary is to bring awareness to the benefits of consistent physiological stimulus (exercise) to combating sarcopenia as well as proclaiming the usefulness of contraction-induced injury models to studying the effects of local and systemic influences on aged myogenic capability.
Collapse
Affiliation(s)
- Susan Tsivitse Arthur
- Department of Kinesiology, Laboratory of Systems Physiology, University North Carolina - Charlotte, Charlotte, NC 28223, USA.
| | | |
Collapse
|
31
|
De Solís AJ, Fernández-Agulló T, García-SanFrutos M, Pérez-Pardo P, Bogónez E, Andrés A, Ros M, Carrascosa JM. Impairment of skeletal muscle insulin action with aging in Wistar rats: Role of leptin and caloric restriction. Mech Ageing Dev 2012; 133:306-16. [DOI: 10.1016/j.mad.2012.03.006] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/23/2011] [Revised: 02/13/2012] [Accepted: 03/06/2012] [Indexed: 01/04/2023]
|
32
|
Sharples AP, Al-Shanti N, Lewis MP, Stewart CE. Reduction of myoblast differentiation following multiple population doublings in mouse C2 C12 cells: a model to investigate ageing? J Cell Biochem 2012; 112:3773-85. [PMID: 21826704 DOI: 10.1002/jcb.23308] [Citation(s) in RCA: 40] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022]
Abstract
Ageing skeletal muscle displays declines in size, strength, and functional capacity. Given the acknowledged role that the systemic environment plays in reduced regeneration (Conboy et al. [2005] Nature 433: 760-764), the role of resident satellite cells (termed myoblasts upon activation) is relatively dismissed, where, multiple cellular divisions in-vivo throughout the lifespan could also impact on muscular deterioration. Using a model of multiple population doublings (MPD) in-vitro thus provided a system in which to investigate the direct impact of extensive cell duplications on muscle cell behavior. C(2) C(12) mouse skeletal myoblasts (CON) were used fresh or following 58 population doublings (MPD). As a result of multiple divisions, reduced morphological and biochemical (creatine kinase, CK) differentiation were observed. Furthermore, MPD cells had significantly increased cells in the S and decreased cells in the G1 phases of the cell cycle versus CON, following serum withdrawal. These results suggest continued cycling rather than G1 exit and thus reduced differentiation (myotube atrophy) occurs in MPD muscle cells. These changes were underpinned by significant reductions in transcript expression of: IGF-I and myogenic regulatory factors (myoD and myogenin) together with elevated IGFBP5. Signaling studies showed that decreased differentiation in MPD was associated with decreased phosphorylation of Akt, and with later increased phosphorylation of JNK1/2. Chemical inhibition of JNK1/2 (SP600125) in MPD cells increased IGF-I expression (non-significantly), however, did not enhance differentiation. This study provides a potential model and molecular mechanisms for deterioration in differentiation capacity in skeletal muscle cells as a consequence of multiple population doublings that would potentially contribute to the ageing process.
Collapse
Affiliation(s)
- Adam P Sharples
- Faculty of Science and Engineering, Institute for Biomedical Research into Human Movement and Health (IRM), Manchester Metropolitan University, John Dalton Building, Oxford Road, Manchester, UK.
| | | | | | | |
Collapse
|
33
|
Lawler JM, Hindle A. Living in a box or call of the wild? Revisiting lifetime inactivity and sarcopenia. Antioxid Redox Signal 2011; 15:2529-41. [PMID: 21539480 PMCID: PMC3176342 DOI: 10.1089/ars.2011.3974] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/02/2023]
Abstract
SIGNIFICANCE The accepted effects of aging in mammalian skeletal muscle are progressive atrophy and weakening, or sarcopenia. Canonical hallmarks of aging in skeletal muscle include a reduction in muscle fiber cross-sectional area, a loss in muscle fibers through apoptosis and denervation, and infiltration of connective tissue or fibrosis. Emerging thought suggests that pro-inflammatory signaling and oxidative stress may contribute to sarcopenia. CRITICAL ISSUES Unfortunately, most of the mammalian models used to examine and understand sarcopenia are confounded by the pervasive influence of prolonged physical inactivity. Further, the potential for underlying metabolic disorder and chronic disease (e.g., type II diabetes and cardiovascular disease) may accelerate skeletal muscle wasting. Because physical inactivity may share elevated pro-inflammatory (tumor necrosis factor-alpha and inducible nitric oxide synthase) and insufficient stress response (insulin-like growth factor-1 [IGF-1], heat-shock protein 25 [HSP25], NAD-dependent deacetylase sirtuin-3 [SIRT-3], and peroxisome proliferator-activated receptor-gamma coactivator 1[PGC-1α]) signaling with aging and chronic disease, it is critical to distinguish true aging from chronic inactivity or underlying disease. Conversely, the efficacy of exercise and caloric restrictive interventions against sarcopenia in aging populations appears highly effective when (a) conducted across the lifespan, or (b) at higher intensities when commenced in middle age or later. RECENT ADVANCES While the prospective mechanisms by which exercise or daily activity provide have not been elucidated, upregulation of HSPs, PGC-1α, and IGF-1 may ameliorate inflammatory signaling, apoptosis, and sarcopenia. Limited data indicate that the aging phenotype exhibited by mammals living in their natural habitat (Weddell seal and shrews) express limited apoptosis and fiber atrophy, whereas significant collagen accumulation remains. In addition, aging shrews displayed a remarkable ability to upregulate antioxidant enzymes (copper, zinc isoform of superoxide dismutase, manganese isoform of superoxide dismutase, catalase, and glutathione peroxidase). FUTURE DIRECTIONS It is possible that in healthy populations requiring daily activity to thrive, fibrosis and weakness, more than atrophy, may be the predominant phenotype of muscle aging until senescence. Elucidating the molecular mechanisms by which lifetime inactivity contributes to sarcopenia and chronic disease will be critical in managing the quality of life and health costs associated with our aging population.
Collapse
Affiliation(s)
- John M Lawler
- Redox Biology & Cell Signaling Laboratory, Department of Health and Kinesiology, Texas A&M University, College Station, 77843–4243, USA.
| | | |
Collapse
|
34
|
Abstract
Type 2 Diabetes mellitus (T2D) is the most common endocrine disorder associated to metabolic syndrome (MS) and occurs when insulin secretion can no compensate peripheral insulin resistance. Among peripheral tissues, the liver controls glucose homeostasis due to its ability to consume and produce glucose. The molecular mechanism underlying hepatic insulin resistance is not completely understood; however, it involves the impairment of the insulin signalling network. Among the critical nodes of hepatic insulin signalling, insulin receptor substrate 2 (IRS2) and protein tyrosine phosphatase 1B (PTP1B) modulate the phosphatidylinositol (PI) 3-kinase/Akt/Foxo1 pathway that controls the suppression of gluconeogenic genes. In this review, we will focus on recent findings regarding the molecular mechanism by which IRS2 and PTP1B elicit opposite effects on carbohydrate metabolism in the liver in response to insulin. Finally, we will discuss the involvement of the critical nodes of insulin signalling in non-alcoholic fatty liver disease (NAFLD) in humans.
Collapse
Affiliation(s)
- Angela M Valverde
- Instituto de Investigaciones Biomédicas Alberto Sols (CSIC/UAM), C/Arturo Duperier 4, 28029 Madrid, Spain.
| | | |
Collapse
|
35
|
Bernier M, Paul RK, Martin-Montalvo A, Scheibye-Knudsen M, Song S, He HJ, Armour SM, Hubbard BP, Bohr VA, Wang L, Zong Y, Sinclair DA, de Cabo R. Negative regulation of STAT3 protein-mediated cellular respiration by SIRT1 protein. J Biol Chem 2011; 286:19270-9. [PMID: 21467030 DOI: 10.1074/jbc.m110.200311] [Citation(s) in RCA: 103] [Impact Index Per Article: 7.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/29/2023] Open
Abstract
In mammals, the transcriptional activity of signal transducer and activator of transcription 3 (STAT3) is regulated by the deacetylase SIRT1. However, whether the newly described nongenomic actions of STAT3 toward mitochondrial oxidative phosphorylation are dependent on SIRT1 is unclear. In this study, Sirt1 gene knock-out murine embryonic fibroblast (MEF) cells were used to delineate the role of SIRT1 in the regulation of STAT3 mitochondrial function. Here, we show that STAT3 mRNA and protein levels and the accumulation of serine-phosphorylated STAT3 in mitochondria were increased significantly in Sirt1-KO cells as compared with wild-type MEFs. Various mitochondrial bioenergetic parameters, such as the oxygen consumption rate in cell cultures, enzyme activities of the electron transport chain complexes in isolated mitochondria, and production of ATP and lactate, indicated that Sirt1-KO cells exhibited higher mitochondrial respiration as compared with wild-type MEFs. Two independent approaches, including ectopic expression of SIRT1 and siRNA-mediated knockdown of STAT3, led to reduction in intracellular ATP levels and increased lactate production in Sirt1-KO cells that were approaching those of wild-type controls. Comparison of profiles of phospho-antibody array data indicated that the deletion of SirT1 was accompanied by constitutive activation of the pro-inflammatory NF-κB pathway, which is key for STAT3 induction and increased cellular respiration in Sirt1-KO cells. Thus, SIRT1 appears to be a functional regulator of NF-κB-dependent STAT3 expression that induces mitochondrial biogenesis. These results have implications for understanding the interplay between STAT3 and SIRT1 in pro-inflammatory conditions.
Collapse
Affiliation(s)
- Michel Bernier
- Laboratory of Clinical Investigation, National Institute on Aging, National Institutes of Health, Baltimore, Maryland 21224, USA.
| | | | | | | | | | | | | | | | | | | | | | | | | |
Collapse
|
36
|
Gómez-Pérez Y, Gianotti M, Proenza AM, Lladó I. Age-Related Decline of Skeletal Muscle Insulin Sensitivity in Rats: Effect of Sex and Muscle Type. Rejuvenation Res 2011; 14:153-61. [DOI: 10.1089/rej.2010.1107] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023] Open
Affiliation(s)
- Yolanda Gómez-Pérez
- Grup de 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, Palma de Mallorca, Illes Balears, Spain
- Ciber Fisiopatología Obesidad y Nutrición (CB06/03), Instituto de Salud Carlos III, Madrid, Spain
| | - Magdalena Gianotti
- Grup de 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, Palma de Mallorca, Illes Balears, Spain
- Ciber Fisiopatología Obesidad y Nutrición (CB06/03), Instituto de Salud Carlos III, Madrid, Spain
| | - Ana M. Proenza
- Grup de 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, Palma de Mallorca, Illes Balears, Spain
- Ciber Fisiopatología Obesidad y Nutrición (CB06/03), Instituto de Salud Carlos III, Madrid, Spain
| | - Isabel Lladó
- Grup de 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, Palma de Mallorca, Illes Balears, Spain
- Ciber Fisiopatología Obesidad y Nutrición (CB06/03), Instituto de Salud Carlos III, Madrid, Spain
| |
Collapse
|
37
|
Menzies KJ, Hood DA. The role of SirT1 in muscle mitochondrial turnover. Mitochondrion 2011; 12:5-13. [PMID: 21406254 DOI: 10.1016/j.mito.2011.03.001] [Citation(s) in RCA: 36] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2010] [Revised: 02/09/2011] [Accepted: 03/03/2011] [Indexed: 12/19/2022]
Abstract
SirT1 protein has received considerable attention for its potential role in longevity. It has been described as a metabolic protein that can sense and communicate the energy status of a cell to key mechanisms of mitochondrial regulation and energy production. These mechanisms include the biogenesis of mitochondria, the clearance of damaged organelles, and the physiological rhythmicity of gene expression. Elucidation of the pathways involved in SirT1-mediated mitochondrial turnover ultimately allow for the design of pharmaceuticals for the treatment of degenerative processes that are associated with metabolic and mitochondrial health.
Collapse
Affiliation(s)
- Keir J Menzies
- Department of Biology, York University, Toronto, Ontario, Canada M3J 1P3
| | | |
Collapse
|