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Ding B, Fan Y, Zhu T, Bai G, Liang B, Tian X, Xie X. l-norleucine on high glucose-induced insulin sensitivity and mitochondrial function in skeletal muscle cells. Biochem Biophys Res Commun 2024; 705:149742. [PMID: 38460438 DOI: 10.1016/j.bbrc.2024.149742] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/23/2024] [Revised: 02/28/2024] [Accepted: 02/28/2024] [Indexed: 03/11/2024]
Abstract
l-norleucine, an isomer of leucine, stimulates the anabolic process of insulin. However, it is not known if and how it improves insulin sensitivity and insulin resistance. This experiment describes the generation of an insulin resistance model using high glucose-induced cells and the administration of 1.0 mmol/L l-norleucine for 48 h, to observe the effects on metabolism and gene expression in skeletal muscle cells. The results showed that l-norleucine significantly increased mitochondrial ATP content, decreased the amount of reactive oxygen species (ROS) and promoted the expression of mitochondrial generation-related genes TFAM, AMPK, PGC-1α in cells under high glucose treatment; at the same time, l-norleucine also increased glucose uptake, suggesting that l-norleucine increased insulin sensitivity and improved insulin resistance. This study suggesting that l-norleucine improves insulin resistance by ameliorating oxidative stress damage of mitochondria, improving mitochondrial function, and improving insulin sensitivity in skeletal muscle cell caused by high glucose, rather than by altering mitochondrial efficiency.
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Affiliation(s)
- Bingqian Ding
- School of Clinical Medicine, Ningxia Medical University, Yinchuan, 750004, China
| | - Yalei Fan
- School of Clinical Medicine, Ningxia Medical University, Yinchuan, 750004, China
| | - Tingting Zhu
- School of Public Health and Management, Ningxia Medical University, Yinchuan, 750004, China
| | - Guirong Bai
- Department of Endocrinology, The First People's Hospital of Yinchuan, Yinchuan, 750001, China
| | - Bingbing Liang
- School of Clinical Medicine, Ningxia Medical University, Yinchuan, 750004, China
| | - Xinyi Tian
- School of Clinical Medicine, Ningxia Medical University, Yinchuan, 750004, China
| | - Xiaomin Xie
- Department of Endocrinology, The First People's Hospital of Yinchuan, Yinchuan, 750001, China.
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Nakanishi R, Tanaka M, Nisa BU, Shimizu S, Hirabayashi T, Tanaka M, Maeshige N, Roy RR, Fujino H. Alternating current electromagnetic field exposure lessens intramyocellular lipid accumulation due to high-fat feeding via enhanced lipid metabolism in mice. PLoS One 2023; 18:e0289086. [PMID: 38011220 PMCID: PMC10681264 DOI: 10.1371/journal.pone.0289086] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/16/2023] [Accepted: 07/11/2023] [Indexed: 11/29/2023] Open
Abstract
Long-term high-fat feeding results in intramyocellular lipid accumulation, leading to insulin resistance. Intramyocellular lipid accumulation is related to an energy imbalance between excess fat intake and fatty acid consumption. Alternating current electromagnetic field exposure has been shown to enhance mitochondrial metabolism in the liver and sperm. Therefore, we hypothesized that alternating current electromagnetic field exposure would ameliorate high-fat diet-induced intramyocellular lipid accumulation via activation of fatty acid consumption. C57BL/6J mice were either fed a normal diet (ND), a normal diet and exposed to an alternating current electromagnetic field (ND+EMF), a high-fat diet (HFD), or a high-fat diet and exposed to an alternating current electromagnetic field (HFD+EMF). Electromagnetic field exposure was administered 8 hrs/day for 16 weeks using an alternating current electromagnetic field device (max.180 mT, Hokoen, Utatsu, Japan). Tibialis anterior muscles were collected for measurement of intramyocellular lipids, AMPK phosphorylation, FAT/CD-36, and carnitine palmitoyltransferase (CPT)-1b protein expression levels. Intramyocellular lipid levels were lower in the HFD + EMF than in the HFD group. The levels of AMPK phosphorylation, FAT/CD-36, and CPT-1b protein levels were higher in the HFD + EMF than in the HFD group. These results indicate that alternating current electromagnetic field exposure decreases intramyocellular lipid accumulation via increased fat consumption.
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Affiliation(s)
- Ryosuke Nakanishi
- Department of Rehabilitation Science, Kobe University Graduate School of Health Sciences, Kobe, Japan
- Department of Physical Therapy, Kobe International University, Kobe, Japan
| | - Masayuki Tanaka
- Department of Rehabilitation Science, Kobe University Graduate School of Health Sciences, Kobe, Japan
- Department of Physical Therapy, Okayama Healthcare Professional University, Okayama, Japan
| | - Badur un Nisa
- Department of Rehabilitation Science, Kobe University Graduate School of Health Sciences, Kobe, Japan
| | - Sayaka Shimizu
- Department of Rehabilitation Science, Kobe University Graduate School of Health Sciences, Kobe, Japan
| | - Takumi Hirabayashi
- Department of Rehabilitation Science, Kobe University Graduate School of Health Sciences, Kobe, Japan
| | - Minoru Tanaka
- Department of Rehabilitation Science, Kobe University Graduate School of Health Sciences, Kobe, Japan
- Department of Rehabilitation Science, Osaka Health Science University, Osaka, Japan
| | - Noriaki Maeshige
- Department of Rehabilitation Science, Kobe University Graduate School of Health Sciences, Kobe, Japan
| | - Roland R. Roy
- Brain Research Institute and Department of Integrative Biology and Physiology, University of California, Los Angeles, Los Angeles, CA, United States of America
| | - Hidemi Fujino
- Department of Rehabilitation Science, Kobe University Graduate School of Health Sciences, Kobe, Japan
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Altered sialin mRNA gene expression in type 2 diabetic male Wistar rats: implications for nitric oxide deficiency. Sci Rep 2023; 13:4013. [PMID: 36899088 PMCID: PMC10006425 DOI: 10.1038/s41598-023-31240-4] [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: 01/25/2023] [Accepted: 03/08/2023] [Indexed: 03/12/2023] Open
Abstract
Nitrate therapy has been suggested to boost nitric oxide (NO) levels in type 2 diabetes (T2D); however, little is known about nitrate transport across the membranes. This study aimed to assess changes in the mRNA expression of sialin, as a nitrate transporter, in the main tissues of rats with T2D. Rats were divided into two groups (n = 6/group): Control and T2D. A high-fat diet combined with a low dose of streptozotocin (STZ, 30 mg/kg) was used to induce T2D. At month 6, samples from the main tissues of rats were used to measure the mRNA expression of sialin and levels of NO metabolites. Rats with T2D had lower nitrate levels in the soleus muscle (66%), lung (48%), kidney (43%), aorta (30%), adrenal gland (58%), epididymal adipose tissue (eAT) (61%), and heart (37%) and had lower nitrite levels in the pancreas (47%), kidney (42%), aorta (33%), liver (28%), eAT (34%), and heart (32%). The order of sialin gene expression in control rats was: soleus muscle > kidney > pancreas > lung > liver > adrenal gland > brain > eAT > intestine > stomach > aorta > heart. Compared to controls, rats with T2D had higher sialin mRNA expressions in the stomach (2.1), eAT (2.0), adrenal gland (1.7), liver (8.9), and soleus muscle (3.4), and lower sialin expression in the intestine (0.56), pancreas (0.42), and kidney (0.44), all P values < 0.05. These findings indicate altered sialin mRNA expression in the main tissues of male T2D rats and may have implications for future NO-based treatment of T2D.
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Kim I, Seok SH, Lee HY. Development of a Zebrafish Larvae Model for Diabetic Heart Failure With Reduced Ejection Fraction. Korean Circ J 2022; 53:34-46. [PMID: 36627738 PMCID: PMC9834558 DOI: 10.4070/kcj.2022.0210] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/01/2022] [Revised: 10/19/2022] [Accepted: 11/09/2022] [Indexed: 12/24/2022] Open
Abstract
BACKGROUND AND OBJECTIVES Diabetes mellitus (DM)-associated heart failure (HF) causes high morbidity and mortality. In this study, we established a zebrafish larvae model for in vivo research on diabetic HF. METHODS DM-like phenotypes were induced by treating zebrafish larvae with a combination of D-glucose (GLU) and streptozotocin (STZ). HF was induced by treatment with terfenadine (TER), a potassium channel blocker. Additionally, myocardial contractility, motility, and viability were evaluated. RESULTS The zebrafish larvae treated with a combination of GLU and STZ showed significantly higher whole-body glucose concentrations, lower insulin levels, and higher phosphoenolpyruvate carboxykinase levels, which are markers of abnormal glucose homeostasis, than the group treated with only GLU, with no effect on viability. When treated with TER, DM zebrafish showed significantly less myocardial fractional shortening and more irregular contractions than the non-DM zebrafish. Furthermore, in DM-HF with reduced ejection fraction (rEF) zebrafish, a significant increase in the levels of natriuretic peptide B, a HF biomarker, markedly reduced motility, and reduced survival rates were observed. CONCLUSIONS We established a DM-HFrEF zebrafish model by sequentially treating zebrafish larvae with GLU, STZ, and TER. Our findings indicate the potential utility of the developed zebrafish larvae model not only in screening studies of new drug candidates for DM-HFrEF but also in mechanistic studies to understand the pathophysiology of DM-HFrEF.
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Affiliation(s)
- Inho Kim
- Department of Internal Medicine, Seoul National University Hospital, Seoul, Korea.,Department of Microbiology and Immunology, Seoul National University College of Medicine, Seoul, Korea
| | - Seung Hyeok Seok
- Department of Microbiology and Immunology, Seoul National University College of Medicine, Seoul, Korea.,Department of Biomedical Sciences, Seoul National University College of Medicine, Seoul, Korea
| | - Hae-Young Lee
- Department of Internal Medicine, Seoul National University Hospital, Seoul, Korea.,Department of Internal Medicine, Seoul National University College of Medicine, Seoul, Korea
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Wang J, Wu J, Li W, Wang X, Liu R, Liu T, Xiao J. Linking Mitochondrial Function to Insulin Resistance: Focusing on Comparing the Old and the Young. Front Nutr 2022; 9:892719. [PMID: 35811955 PMCID: PMC9260383 DOI: 10.3389/fnut.2022.892719] [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: 03/09/2022] [Accepted: 05/16/2022] [Indexed: 11/13/2022] Open
Abstract
Long-term intake of high-energy diet can lead to decreased insulin sensitivity and even insulin resistance, eventually leading to diabetes. Diabetes often occurs in middle-aged and elderly people. However, there is growing evidence that the incidence rate of young body is increasing over the years. This means that insulin resistance can be caused by excessive energy intake in both young and old people. In this study, high-fat diet (HFD) and normal diet were fed to rats of elderly experimental group (EE), elderly control group (EC), young experimental group (YE), and young control group (YC), respectively, for 8 weeks, by which insulin resistance model was obtained. Insulin sensitivity was measured, histopathology changes in liver and skeletal muscle tissues were observed, and mitochondrial fusion and division and cell senescence were detected in four groups of rats. The results showed that both young and elderly rats developed significant insulin resistance, fat deposition, decline of mitochondrial function and mitochondrial biosynthesis in liver and skeletal muscle, and cell aging after HFD feeding. In addition, the degree of mitochondrial dysfunction and aging in young rats was similar to that of aged rats fed a normal diet after HFD. This experiment provides a reference for an in-depth study of the regulatory mechanisms of cellular energy metabolism in this state.
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Affiliation(s)
- Jingxuan Wang
- Key Laboratory for Prevention and Control of Common Animal Diseases in General Higher Education Institutions of Heilongjiang Province, College of Veterinary Medicine, Northeast Agricultural University, Harbin, China
- College of Veterinary Medicine, Northeast Agricultural University, Harbin, China
| | - Junnan Wu
- Key Laboratory for Prevention and Control of Common Animal Diseases in General Higher Education Institutions of Heilongjiang Province, College of Veterinary Medicine, Northeast Agricultural University, Harbin, China
- College of Veterinary Medicine, Northeast Agricultural University, Harbin, China
| | - Wenjing Li
- Key Laboratory for Prevention and Control of Common Animal Diseases in General Higher Education Institutions of Heilongjiang Province, College of Veterinary Medicine, Northeast Agricultural University, Harbin, China
- College of Veterinary Medicine, Northeast Agricultural University, Harbin, China
| | - Xinyu Wang
- Key Laboratory for Prevention and Control of Common Animal Diseases in General Higher Education Institutions of Heilongjiang Province, College of Veterinary Medicine, Northeast Agricultural University, Harbin, China
- College of Veterinary Medicine, Northeast Agricultural University, Harbin, China
| | - Ruifang Liu
- Key Laboratory for Prevention and Control of Common Animal Diseases in General Higher Education Institutions of Heilongjiang Province, College of Veterinary Medicine, Northeast Agricultural University, Harbin, China
- College of Veterinary Medicine, Northeast Agricultural University, Harbin, China
| | - Tao Liu
- Key Laboratory for Prevention and Control of Common Animal Diseases in General Higher Education Institutions of Heilongjiang Province, College of Veterinary Medicine, Northeast Agricultural University, Harbin, China
- College of Veterinary Medicine, Northeast Agricultural University, Harbin, China
| | - Jianhua Xiao
- Key Laboratory for Prevention and Control of Common Animal Diseases in General Higher Education Institutions of Heilongjiang Province, College of Veterinary Medicine, Northeast Agricultural University, Harbin, China
- College of Veterinary Medicine, Northeast Agricultural University, Harbin, China
- *Correspondence: Jianhua Xiao
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Kido K, Egawa T, Watanabe S, Kawanaka K, Treebak JT, Hayashi T. Fasting potentiates insulin-mediated glucose uptake in rested and prior-contracted rat skeletal muscle. Am J Physiol Endocrinol Metab 2022; 322:E425-E435. [PMID: 35344394 DOI: 10.1152/ajpendo.00412.2021] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
A single bout of exercise can potentiate the effect of insulin on skeletal muscle glucose uptake via activation of the AMPK-TBC1 domain family member 4 (TBC1D4) pathway, which suggests a positive correlation between AMPK activation and insulin sensitization. In addition, prolonged fasting in rodents is known to upregulate and thereby synergistically enhance the effect of exercise on muscle AMPK activation. Therefore, fasting may potentiate the insulin-sensitizing effect of exercise. In the present study, we mimicked exercise by in situ muscle contraction and evaluated the effect of a 36-h fast on muscle contraction-induced insulin sensitization. Male Wistar rats weighing 150-170 g were allocated to either a 36-h fasting or feeding group. The extensor digitorum longus (EDL) muscles were electrically contracted via the common peroneal nerve for 10 min followed by a 3-h recovery period. EDL muscles were dissected and incubated in the presence or absence of submaximal insulin. Our results demonstrated that acute muscle contraction and 36 h of fasting additively upregulated AMPK pathway activation. Insulin-stimulated muscle glucose uptake and site-specific TBC1D4 phosphorylation were enhanced by prior muscle contraction in 36-h-fasted rats, but not in fed rats. Moreover, enhanced insulin-induced muscle glucose uptake and Akt phosphorylation due to 36 h of fasting were associated with a decrease in tribbles homolog 3 (TRB3), a negative regulator of Akt activation. In conclusion, fasting and prior muscle contraction synergistically enhance insulin-stimulated TBC1D4 phosphorylation and glucose uptake, which is associated with augmented AMPK pathway activation in rodents.NEW & NOTEWORTHY In this study, we revealed that 36 h of fasting additively upregulated acute muscle contraction-induced AMPK pathway activation in rats. Besides, fasting and muscle contraction synergistically enhanced insulin-stimulated site-specific TBC1D4 phosphorylation and glucose uptake, which was associated with augmented AMPK pathway activation. These results contribute to understanding the regulation of muscle insulin sensitivity.
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Affiliation(s)
- Kohei Kido
- Laboratory of Sports and Exercise Medicine, Graduate School of Human and Environmental Studies, Kyoto University, Kyoto, Japan
- Faculty of Sports and Health Science, Fukuoka University, Fukuoka, Japan
- Institute for Physical Activity, Fukuoka University, Fukuoka, Japan
| | - Tatsuro Egawa
- Laboratory of Sports and Exercise Medicine, Graduate School of Human and Environmental Studies, Kyoto University, Kyoto, Japan
| | - Shinya Watanabe
- Faculty of Sports and Health Science, Fukuoka University, Fukuoka, Japan
| | - Kentaro Kawanaka
- Faculty of Sports and Health Science, Fukuoka University, Fukuoka, Japan
- Institute for Physical Activity, Fukuoka University, Fukuoka, Japan
| | - Jonas T Treebak
- Faculty of Health and Medical Sciences, Novo Nordisk Foundation Center for Basic Metabolic Research, University of Copenhagen, Copenhagen, Denmark
| | - Tatsuya Hayashi
- Laboratory of Sports and Exercise Medicine, Graduate School of Human and Environmental Studies, Kyoto University, Kyoto, Japan
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Wang H, Arias EB, Treebak JT, Cartee GD. Exercise effects on γ3-AMPK activity, Akt substrate of 160 kDa phosphorylation, and glucose uptake in muscle of normal and insulin-resistant female rats. J Appl Physiol (1985) 2022; 132:140-153. [PMID: 34882030 PMCID: PMC8759959 DOI: 10.1152/japplphysiol.00533.2021] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023] Open
Abstract
Previous studies demonstrated that acute exercise can enhance glucose uptake (GU), γ3-AMP-activated protein kinase (AMPK) activity, and Akt substrate of 160 kDa (AS160) phosphorylation in skeletal muscles from low-fat diet (LFD)- and high-fat diet (HFD)-fed male rats. Because little is known about exercise effects on these outcomes in females, we assessed postexercise GU by muscles incubated ± insulin, delta-insulin GU (GU of muscles incubated with insulin minus GU uptake of paired muscles incubated without insulin), and muscle signaling proteins from female rats fed a LFD or a brief HFD (2 wk). Rats were sedentary (LFD-SED, HFD-SED) or swim exercised. Immediately postexercise (IPEX) or 3 h postexercise (3hPEX), epitrochlearis muscles were incubated (no insulin IPEX; ±insulin 3hPEX) to determine GU. Muscle γ3-AMPK activity (IPEX, 3hPEX) and phosphorylated AS160 (pAS160; 3hPEX) were also assessed. γ3-AMPK activity and insulin-independent GU of IPEX rats exceeded sedentary rats without diet-related differences in either outcome. At 3hPEX, both GU by insulin-stimulated muscles and delta-insulin GU exceeded their respective diet-matched sedentary controls. GU by insulin-stimulated muscles, but not delta-insulin GU for LFD-3hPEX, exceeded HFD-3hPEX. LFD-3hPEX versus LFD-SED had greater γ3-AMPK activity and greater pAS160. HFD-3hPEX exceeded HFD-SED for pAS160 but not for γ3-AMPK activity. pAS160 and γ3-AMPK at 3hPEX did not differ between diet groups. These results revealed that increased γ3-AMPK activity at 3hPEX was not essential for greater GU in insulin-stimulated muscle or greater delta-insulin GU in HFD female rats. Similarly elevated γ3-AMPK activity in LFD-IPEX versus HFD-IPEX and pAS160 in LFD-3hPEX versus HFD-3hPEX may contribute to the comparable delta-insulin GU at 3hPEX in both diet groups.NEW & NOTEWORTHY Glucose uptake (GU) and phosphorylated AS160 (pAS160) by insulin-stimulated muscles at 3 h postexercise (3hPEX) exceeded diet-matched controls in female low-fat diet-fed (LFD) or high-fat diet-fed (HFD) rats. GU with insulin for LFD-3hPEX exceeded HFD-3hPEX, whereas pAS160 was similar between these groups. γ3-AMPK immediately postexercise (IPEX) was similarly elevated in LFD and HFD, but only LFD-3hPEX had increased γ3-AMPK. These results suggest that greater γ3-AMPK at IPEX and pAS160 at 3hPEX may contribute to elevated GU with insulin, but greater γ3-AMPK at 3hPEX was dispensable for female HFD rats.
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Affiliation(s)
- Haiyan Wang
- 1Muscle Biology Laboratory, School of Kinesiology, University of Michigan, Ann Arbor, Michigan
| | - Edward B. Arias
- 1Muscle Biology Laboratory, School of Kinesiology, University of Michigan, Ann Arbor, Michigan
| | - Jonas T. Treebak
- 2Novo Nordisk Foundation Center for Basic Metabolic Research, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
| | - Gregory D. Cartee
- 1Muscle Biology Laboratory, School of Kinesiology, University of Michigan, Ann Arbor, Michigan,3Department of Molecular and Integrative Physiology, University of Michigan, Ann Arbor, Michigan,4Institute of Gerontology, University of Michigan, Ann Arbor, Michigan
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Takahashi Y, Matsunaga Y, Yoshida H, Shinya T, Sakaguchi R, Hatta H. High Carbohydrate Diet Increased Glucose Transporter Protein Levels in Jejunum but Did Not Lead to Enhanced Post-Exercise Skeletal Muscle Glycogen Recovery. Nutrients 2021; 13:nu13072140. [PMID: 34206627 PMCID: PMC8308400 DOI: 10.3390/nu13072140] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/02/2021] [Revised: 06/18/2021] [Accepted: 06/21/2021] [Indexed: 11/16/2022] Open
Abstract
We examined the effect of dietary carbohydrate intake on post-exercise glycogen recovery. Male Institute of Cancer Research (ICR) mice were fed moderate-carbohydrate chow (MCHO, 50%cal from carbohydrate) or high-carbohydrate chow (HCHO, 70%cal from carbohydrate) for 10 days. They then ran on a treadmill at 25 m/min for 60 min and administered an oral glucose solution (1.5 mg/g body weight). Compared to the MCHO group, the HCHO group showed significantly higher sodium-D-glucose co-transporter 1 protein levels in the brush border membrane fraction (p = 0.003) and the glucose transporter 2 level in the mucosa of jejunum (p = 0.004). At 30 min after the post-exercise glucose administration, the skeletal muscle and liver glycogen levels were not significantly different between the two diet groups. The blood glucose concentration from the portal vein (which is the entry site of nutrients from the gastrointestinal tract) was not significantly different between the groups at 15 min after the post-exercise glucose administration. There was no difference in the total or phosphorylated states of proteins related to glucose uptake and glycogen synthesis in skeletal muscle. Although the high-carbohydrate diet significantly increased glucose transporters in the jejunum, this adaptation stimulated neither glycogen recovery nor glucose absorption after the ingestion of post-exercise glucose.
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Affiliation(s)
- Yumiko Takahashi
- Department of Sports Sciences, The University of Tokyo, 3-8-1 Komaba, Meguro, Tokyo 153-8902, Japan; (Y.M.); (H.Y.); (T.S.); (R.S.); (H.H.)
- Department of Sport Research, Japan Institute of Sports Sciences, 3-15-1 Nishigaoka, Kita, Tokyo 115-0056, Japan
- Correspondence: ; Tel.: +81-3-5963-0238
| | - Yutaka Matsunaga
- Department of Sports Sciences, The University of Tokyo, 3-8-1 Komaba, Meguro, Tokyo 153-8902, Japan; (Y.M.); (H.Y.); (T.S.); (R.S.); (H.H.)
| | - Hiroki Yoshida
- Department of Sports Sciences, The University of Tokyo, 3-8-1 Komaba, Meguro, Tokyo 153-8902, Japan; (Y.M.); (H.Y.); (T.S.); (R.S.); (H.H.)
| | - Terunaga Shinya
- Department of Sports Sciences, The University of Tokyo, 3-8-1 Komaba, Meguro, Tokyo 153-8902, Japan; (Y.M.); (H.Y.); (T.S.); (R.S.); (H.H.)
| | - Ryo Sakaguchi
- Department of Sports Sciences, The University of Tokyo, 3-8-1 Komaba, Meguro, Tokyo 153-8902, Japan; (Y.M.); (H.Y.); (T.S.); (R.S.); (H.H.)
| | - Hideo Hatta
- Department of Sports Sciences, The University of Tokyo, 3-8-1 Komaba, Meguro, Tokyo 153-8902, Japan; (Y.M.); (H.Y.); (T.S.); (R.S.); (H.H.)
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Garrigos D, Martínez-Morga M, Toval A, Kutsenko Y, Barreda A, Do Couto BR, Navarro-Mateu F, Ferran JL. A Handful of Details to Ensure the Experimental Reproducibility on the FORCED Running Wheel in Rodents: A Systematic Review. Front Endocrinol (Lausanne) 2021; 12:638261. [PMID: 34040580 PMCID: PMC8141847 DOI: 10.3389/fendo.2021.638261] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/05/2020] [Accepted: 04/16/2021] [Indexed: 12/21/2022] Open
Abstract
A well-documented method and experimental design are essential to ensure the reproducibility and reliability in animal research. Experimental studies using exercise programs in animal models have experienced an exponential increase in the last decades. Complete reporting of forced wheel and treadmill exercise protocols would help to ensure the reproducibility of training programs. However, forced exercise programs are characterized by a poorly detailed methodology. Also, current guidelines do not cover the minimum data that must be included in published works to reproduce training programs. For this reason, we have carried out a systematic review to determine the reproducibility of training programs and experimental designs of published research in rodents using a forced wheel system. Having determined that most of the studies were not detailed enough to be reproducible, we have suggested guidelines for animal research using FORCED exercise wheels, which could also be applicable to any form of forced exercise.
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Affiliation(s)
- Daniel Garrigos
- Department of Human Anatomy and Psychobiology, Faculty of Medicine, University of Murcia, Murcia, Spain
- Institute of Biomedical Research of Murcia—IMIB, Virgen de la Arrixaca University Hospital, University of Murcia, Murcia, Spain
| | - Marta Martínez-Morga
- Department of Human Anatomy and Psychobiology, Faculty of Medicine, University of Murcia, Murcia, Spain
- Institute of Biomedical Research of Murcia—IMIB, Virgen de la Arrixaca University Hospital, University of Murcia, Murcia, Spain
| | - Angel Toval
- Department of Human Anatomy and Psychobiology, Faculty of Medicine, University of Murcia, Murcia, Spain
- Institute of Biomedical Research of Murcia—IMIB, Virgen de la Arrixaca University Hospital, University of Murcia, Murcia, Spain
| | - Yevheniy Kutsenko
- Department of Human Anatomy and Psychobiology, Faculty of Medicine, University of Murcia, Murcia, Spain
- Institute of Biomedical Research of Murcia—IMIB, Virgen de la Arrixaca University Hospital, University of Murcia, Murcia, Spain
| | - Alberto Barreda
- Department of Human Anatomy and Psychobiology, Faculty of Medicine, University of Murcia, Murcia, Spain
- Institute of Biomedical Research of Murcia—IMIB, Virgen de la Arrixaca University Hospital, University of Murcia, Murcia, Spain
| | - Bruno Ribeiro Do Couto
- Department of Human Anatomy and Psychobiology, Faculty of Medicine, University of Murcia, Murcia, Spain
- Institute of Biomedical Research of Murcia—IMIB, Virgen de la Arrixaca University Hospital, University of Murcia, Murcia, Spain
- Faculty of Psychology, University of Murcia, Murcia, Spain
| | - Fernando Navarro-Mateu
- Institute of Biomedical Research of Murcia—IMIB, Virgen de la Arrixaca University Hospital, University of Murcia, Murcia, Spain
- Unidad de Docencia, Investigación y Formación en Salud Mental (UDIF-SM), Servicio Murciano de Salud, Murcia, Spain
- CIBER de Epidemiología y Salud Pública (CIBERESP), Madrid, Spain
- Departamento de Psicología Básica y Metodología, Universidad de Murcia, Murcia, Spain
| | - José Luis Ferran
- Department of Human Anatomy and Psychobiology, Faculty of Medicine, University of Murcia, Murcia, Spain
- Institute of Biomedical Research of Murcia—IMIB, Virgen de la Arrixaca University Hospital, University of Murcia, Murcia, Spain
- *Correspondence: José Luis Ferran,
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Béland-Millar A, Takimoto M, Hamada T, Messier C. Brain and muscle adaptation to high-fat diets and exercise: Metabolic transporters, enzymes and substrates in the rat cortex and muscle. Brain Res 2020; 1749:147126. [PMID: 32946799 DOI: 10.1016/j.brainres.2020.147126] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/01/2020] [Revised: 08/10/2020] [Accepted: 09/11/2020] [Indexed: 11/28/2022]
Abstract
There is evidence suggesting that the effects of diet and physical activity on physical and mental well-being are the result of altered metabolic profiles. Though the central and peripheral systems work in tandem, the interactions between peripheral and central changes that lead to these altered states of well-being remains elusive. We measured changes in the metabolic profile of brain (cortex) and muscle (soleus and plantaris) tissue in rats following 5-weeks of treadmill exercise and/or a high-fat diet to evaluate peripheral and central interactions as well as identify any common adaptive mechanisms. To characterize changes in metabolic profiles, we measured relative changes in key metabolic enzymes (COX IV, hexokinase, LDHB, PFK), substrates (BHB, FFA, glucose, lactate, insulin, glycogen, BDNF) and transporters (MCT1, MCT2, MCT4, GLUT1, GLUT3). In the cortex, there was an increase in MCT1 and a decrease in glycogen following the high-fat diet, suggesting an increased reliance on monocarboxylates. Muscle changes were dependent muscle type. Within the plantaris, a high-fat diet increased the oxidative capacity of the muscle likely supported by increased glycolysis, whereas exercise increased the oxidative capacity of the muscle likely supported via increased glycogen synthesis. There was no effect of diet on soleus measurements, but exercise increased its oxidative capacity likely fueled by endogenous and exogenous monocarboxylates. For both the plantaris and soleus, combining exercise training and high-fat diet mediated results, resulting in a middling effect. Together, these results indicate the variable adaptions of two main metabolic pathways: glycolysis and oxidative phosphorylation. The results also suggest a dynamic relationship between the brain and body.
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Affiliation(s)
- Alexandria Béland-Millar
- School of Psychology, University of Ottawa, 136 Jean-Jacques Lussier, Ottawa, ON K1N 6N5, Canada.
| | - Masaki Takimoto
- Laboratory of Exercise Physiology and Biochemistry, Graduate School of Sport and Exercise Sciences, Osaka University of Health and Sport Sciences, Osaka, Japan
| | - Taku Hamada
- Laboratory of Exercise Physiology and Biochemistry, Graduate School of Sport and Exercise Sciences, Osaka University of Health and Sport Sciences, Osaka, Japan
| | - Claude Messier
- School of Psychology, University of Ottawa, 136 Jean-Jacques Lussier, Ottawa, ON K1N 6N5, Canada
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11
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Excess Accumulation of Lipid Impairs Insulin Sensitivity in Skeletal Muscle. Int J Mol Sci 2020; 21:ijms21061949. [PMID: 32178449 PMCID: PMC7139950 DOI: 10.3390/ijms21061949] [Citation(s) in RCA: 32] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/18/2020] [Revised: 03/09/2020] [Accepted: 03/10/2020] [Indexed: 12/12/2022] Open
Abstract
Both glucose and free fatty acids (FFAs) are used as fuel sources for energy production in a living organism. Compelling evidence supports a role for excess fatty acids synthesized in intramuscular space or dietary intermediates in the regulation of skeletal muscle function. Excess FFA and lipid droplets leads to intramuscular accumulation of lipid intermediates. The resulting downregulation of the insulin signaling cascade prevents the translocation of glucose transporter to the plasma membrane and glucose uptake into skeletal muscle, leading to metabolic disorders such as type 2 diabetes. The mechanisms underlining metabolic dysfunction in skeletal muscle include accumulation of intracellular lipid derivatives from elevated plasma FFAs. This paper provides a review of the molecular mechanisms underlying insulin-related signaling pathways after excess accumulation of lipids.
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12
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Pataky MW, Arias EB, Wang H, Zheng X, Cartee GD. Exercise effects on γ3-AMPK activity, phosphorylation of Akt2 and AS160, and insulin-stimulated glucose uptake in insulin-resistant rat skeletal muscle. J Appl Physiol (1985) 2020; 128:410-421. [PMID: 31944891 DOI: 10.1152/japplphysiol.00428.2019] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
One exercise session can increase subsequent insulin-stimulated glucose uptake (ISGU) by skeletal muscle. Prior research on healthy muscle suggests that enhanced postexercise ISGU depends on elevated γ3-AMPK activity leading to greater phosphorylation of Akt substrate of 160 kDa (pAS160) on an AMPK-phosphomotif (Ser704). Phosphorylation of AS160Ser704, in turn, may favor greater insulin-stimulated pAS160 on an Akt-phosphomotif (Thr642) that regulates ISGU. Accordingly, we tested if exercise-induced increases in γ3-AMPK activity and pAS160 on key regulatory sites accompany improved ISGU at 3 h postexercise (3hPEX) in insulin-resistant muscle. Rats fed a high-fat diet (HFD; 2-wk) that induces insulin resistance either performed acute swim-exercise (2 h) or were sedentary (SED). SED rats fed a low-fat diet (LFD; 2 wk) served as healthy controls. Isolated epitrochlearis muscles from 3hPEX and SED rats were analyzed for ISGU, pAS160, pAkt2 (Akt-isoform that phosphorylates pAS160Thr642), and γ1-AMPK and γ3-AMPK activity. ISGU was lower in HFD-SED muscles versus LFD-SED, but this decrement was eliminated in the HFD-3hPEX group. γ3-AMPK activity, but not γ1-AMPK activity, was elevated in HFD-3hPEX muscles versus both SED controls. Furthermore, insulin-stimulated pAS160Thr642, pAS160Ser704, and pAkt2Ser474 in HFD-3hPEX muscles were elevated above HFD-SED and equal to values in LFD-SED muscles, but insulin-independent pAS160Ser704 was unaltered at 3hPEX. These results demonstrated, for the first time in an insulin-resistant model, that the postexercise increase in ISGU was accompanied by sustained enhancement of γ3-AMPK activation and greater pAkt2Ser474. Our working hypothesis is that these changes along with enhanced insulin-stimulated pAS160 increase ISGU of insulin-resistant muscles to values equaling insulin-sensitive sedentary controls.NEW & NOTEWORTHY Earlier research focusing on signaling events linked to increased insulin sensitivity in muscle has rarely evaluated insulin resistant muscle after exercise. We assessed insulin resistant muscle after an exercise protocol that improved insulin-stimulated glucose uptake. Prior exercise also amplified several signaling steps expected to favor enhanced insulin-stimulated glucose uptake: increased γ3-AMP-activated protein kinase activity, greater insulin-stimulated Akt2 phosphorylation on Ser474, and elevated insulin-stimulated Akt substrate of 160 kDa phosphorylation on Ser588, Thr642, and Ser704.
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Affiliation(s)
- Mark W Pataky
- Muscle Biology Laboratory, School of Kinesiology, University of Michigan, Ann Arbor, Michigan
| | - Edward B Arias
- Muscle Biology Laboratory, School of Kinesiology, University of Michigan, Ann Arbor, Michigan
| | - Haiyan Wang
- Muscle Biology Laboratory, School of Kinesiology, University of Michigan, Ann Arbor, Michigan
| | - Xiaohua Zheng
- Muscle Biology Laboratory, School of Kinesiology, University of Michigan, Ann Arbor, Michigan
| | - Gregory D Cartee
- Muscle Biology Laboratory, School of Kinesiology, University of Michigan, Ann Arbor, Michigan.,Department of Molecular and Integrative Physiology, University of Michigan, Ann Arbor, Michigan.,Institute of Gerontology, University of Michigan, Ann Arbor, Michigan
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13
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Pataky MW, Van Acker SL, Dhingra R, Freeburg MM, Arias EB, Oki K, Wang H, Treebak JT, Cartee GD. Fiber type-specific effects of acute exercise on insulin-stimulated AS160 phosphorylation in insulin-resistant rat skeletal muscle. Am J Physiol Endocrinol Metab 2019; 317:E984-E998. [PMID: 31573845 PMCID: PMC6957376 DOI: 10.1152/ajpendo.00304.2019] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/29/2023]
Abstract
Muscle is a heterogeneous tissue composed of multiple fiber types. Earlier research revealed fiber type-selective postexercise effects on insulin-stimulated glucose uptake (ISGU) from insulin-resistant rats (increased for type IIA, IIB, IIBX, and IIX, but not type I). In whole muscle from insulin-resistant rats, the exercise increase in ISGU is accompanied by an exercise increase in insulin-stimulated AS160 phosphorylation (pAS160), an ISGU-regulating protein. We hypothesized that, in insulin-resistant muscle, the fiber type-selective exercise effects on ISGU would correspond to the fiber type-selective exercise effects on pAS160. Rats were fed a 2-wk high-fat diet (HFD) and remained sedentary (SED) or exercised before epitrochlearis muscles were dissected either immediately postexercise (IPEX) or at 3 h postexercise (3hPEX) using an exercise protocol that previously revealed fiber type-selective effects on ISGU. 3hPEX muscles and SED controls were incubated ± 100µU/mL insulin. Individual myofibers were isolated and pooled on the basis of myosin heavy chain (MHC) expression, and key phosphoproteins were measured. Myofiber glycogen and MHC expression were evaluated in muscles from other SED, IPEX, and 3hPEX rats. Insulin-stimulated pAktSer473 and pAktThr308 were unaltered by exercise in all fiber types. Insulin-stimulated pAS160 was greater for 3hPEX vs. SED on at least one phosphosite (Ser588, Thr642, and/or Ser704) in type IIA, IIBX, and IIB fibers, but not in type I or IIX fibers. Both IPEX and 3hPEX glycogen were decreased versus SED in all fiber types. These results provided evidence that fiber type-specific pAS160 in insulin-resistant muscle may play a role in the previously reported fiber type-specific elevation in ISGU in some, but not all, fiber types.
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Affiliation(s)
- Mark W Pataky
- Muscle Biology Laboratory, School of Kinesiology, University of Michigan, Ann Arbor, Michigan
| | - Sydney L Van Acker
- Muscle Biology Laboratory, School of Kinesiology, University of Michigan, Ann Arbor, Michigan
| | - Rhea Dhingra
- Muscle Biology Laboratory, School of Kinesiology, University of Michigan, Ann Arbor, Michigan
| | - Marina M Freeburg
- Muscle Biology Laboratory, School of Kinesiology, University of Michigan, Ann Arbor, Michigan
| | - Edward B Arias
- Muscle Biology Laboratory, School of Kinesiology, University of Michigan, Ann Arbor, Michigan
| | - Kentaro Oki
- Muscle Biology Laboratory, School of Kinesiology, University of Michigan, Ann Arbor, Michigan
| | - Haiyan Wang
- Muscle Biology Laboratory, School of Kinesiology, University of Michigan, Ann Arbor, Michigan
| | - Jonas T Treebak
- Novo Nordisk Foundation Center for Basic Metabolic Research, University of Copenhagen, Copenhagen, Denmark
| | - Gregory D Cartee
- Muscle Biology Laboratory, School of Kinesiology, University of Michigan, Ann Arbor, Michigan
- Department of Molecular and Integrative Physiology, University of Michigan, Ann Arbor, Michigan
- Institute of Gerontology, University of Michigan, Ann Arbor, Michigan
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Piguet AC, Guarino M, Potaczek DP, Garn H, Dufour JF. Hepatic gene expression in mouse models of non-alcoholic fatty liver disease after acute exercise. Hepatol Res 2019; 49:637-652. [PMID: 30811073 DOI: 10.1111/hepr.13323] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/06/2018] [Revised: 02/12/2019] [Accepted: 02/21/2019] [Indexed: 12/20/2022]
Abstract
AIM Non-alcoholic fatty liver disease (NAFLD) patients benefit from physical exercise. This study aimed to investigate the effect of acute exercise on hepatic gene expression in different mouse models of NAFLD. METHODS C57BL/6J mice were fed with a control (CD) or a high fat (HFD) diet. AlbCrePtenflox/flox (Pten-KO) and Fxr-/- mice, two genetic models of NAFLD with insulin hypersensitivity and resistance, respectively, were fed with CD. After 4 weeks, mice were randomly assigned to exercise or sedentariness. Mice were killed 15 min or 3 h after the running/sedentary period. Genome-wide hepatic gene expression was evaluated with the Illumina Micro-array platform. Quantitative polymerase chain reaction confirmed changes in gene expression. RESULTS Acute exercise transiently affected the expression of genes involved in the immune response in C57BL/6 mice fed with CD and this effect normalized in the recovery phase. Acute exercise affected genes involved in gluconeogenesis in the insulin resistant Fxr-/- model. Genes involved in lipid metabolism were affected in C57BL/6 mice fed with CD, but not in mouse models of NAFLD. Genes involved in DNA damage response pathways were deregulated only in C57BL/6 mice fed with CD and not in mouse models of NAFLD. CONCLUSION The simultaneous analysis of different NAFLD models revealed that an acute exercise bout affects hepatic gene expression differentially according to animal models and that most of the differentially expressed genes are involved in glucose and fatty acid metabolism, immune regulation, and DNA damage response.
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Affiliation(s)
- Anne-Christine Piguet
- Hepatology, Department for BioMedical Research, University of Bern, Bern, Switzerland
| | - Maria Guarino
- Hepatology, Department for BioMedical Research, University of Bern, Bern, Switzerland.,University Clinic of Visceral Surgery and Medicine, Inselspital Bern, Bern, Switzerland.,Gastroenterology, Department of Clinical Medicine and Surgery, University of Naples "Federico II", Naples, Italy
| | - Daniel P Potaczek
- Institute for Laboratory Medicine, member of the German Center for Lung Research (DZL) and the International Inflammation (in-FLAME) Network, Worldwide Universities Network (WUN), Philipps-University Marburg, Marburg, Germany
| | - Holger Garn
- Institute for Laboratory Medicine, member of the German Center for Lung Research (DZL) and the International Inflammation (in-FLAME) Network, Worldwide Universities Network (WUN), Philipps-University Marburg, Marburg, Germany
| | - Jean-François Dufour
- Hepatology, Department for BioMedical Research, University of Bern, Bern, Switzerland.,University Clinic of Visceral Surgery and Medicine, Inselspital Bern, Bern, Switzerland
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15
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Wang H, Arias EB, Pataky MW, Goodyear LJ, Cartee GD. Postexercise improvement in glucose uptake occurs concomitant with greater γ3-AMPK activation and AS160 phosphorylation in rat skeletal muscle. Am J Physiol Endocrinol Metab 2018; 315:E859-E871. [PMID: 30130149 PMCID: PMC6293165 DOI: 10.1152/ajpendo.00020.2018] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/09/2023]
Abstract
A single exercise session can increase insulin-stimulated glucose uptake (GU) by skeletal muscle, concomitant with greater Akt substrate of 160 kDa (AS160) phosphorylation on Akt-phosphosites (Thr642 and Ser588) that regulate insulin-stimulated GU. Recent research using mouse skeletal muscle suggested that ex vivo 5-aminoimidazole-4-carboxamide ribonucleotide (AICAR) or electrically stimulated contractile activity-inducing increased γ3-AMPK activity and AS160 phosphorylation on a consensus AMPK-motif (Ser704) resulted in greater AS160 Thr642 phosphorylation and GU by insulin-stimulated muscle. Our primary goal was to determine whether in vivo exercise that increases insulin-stimulated GU in rat skeletal muscle would also increase γ3-AMPK activity and AS160 site-selective phosphorylation (Ser588, Thr642, and Ser704) immediately postexercise (IPEX) and/or 3 h postexercise (3hPEX). Epitrochlearis muscles isolated from sedentary and exercised (2-h swim exercise; studied IPEX and 3hPEX) rats were incubated with 2-deoxyglucose to determine GU (without insulin at IPEX; without or with insulin at 3hPEX). Muscles were also assessed for γ1-AMPK activity, γ3-AMPK activity, phosphorylated AMPK (pAMPK), and phosphorylated AS160 (pAS160). IPEX versus sedentary had greater γ3-AMPK activity, pAS160 (Ser588, Thr642, Ser704), and GU with unaltered γ1-AMPK activity. 3hPEX versus sedentary had greater γ3-AMPK activity, pAS160 Ser704, and GU with or without insulin; greater pAS160 Thr642 only with insulin; and unaltered γ1-AMPK activity. These results using an in vivo exercise protocol that increased insulin-stimulated GU in rat skeletal muscle are consistent with the hypothesis that in vivo exercise-induced enhancement of γ3-AMPK activation and AS160 Ser704 IPEX and 3hPEX are important for greater pAS160 Thr642 and enhanced insulin-stimulated GU by skeletal muscle.
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Affiliation(s)
- Haiyan Wang
- Muscle Biology Laboratory, School of Kinesiology, University of Michigan , Ann Arbor, Michigan
| | - Edward B Arias
- Muscle Biology Laboratory, School of Kinesiology, University of Michigan , Ann Arbor, Michigan
| | - Mark W Pataky
- Muscle Biology Laboratory, School of Kinesiology, University of Michigan , Ann Arbor, Michigan
| | - Laurie J Goodyear
- Department of Medicine, Brigham and Women's Hospital, Harvard Medical School , Boston, Massachusetts
| | - Gregory D Cartee
- Muscle Biology Laboratory, School of Kinesiology, University of Michigan , Ann Arbor, Michigan
- Department of Molecular and Integrative Physiology, University of Michigan , Ann Arbor, Michigan
- Institute of Gerontology, University of Michigan , Ann Arbor, Michigan
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16
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Nutrient Intake and Physical Exercise Significantly Impact Physical Performance, Body Composition, Blood Lipids, Oxidative Stress, and Inflammation in Male Rats. Nutrients 2018; 10:nu10081109. [PMID: 30126091 PMCID: PMC6115754 DOI: 10.3390/nu10081109] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2018] [Revised: 08/13/2018] [Accepted: 08/15/2018] [Indexed: 11/17/2022] Open
Abstract
BACKGROUND Humans consuming a purified vegan diet known as the "Daniel Fast" realize favorable changes in blood lipids, oxidative stress, and inflammatory biomarkers, with subjective reports of improved physical capacity. OBJECTIVE We sought to determine if this purified vegan diet was synergistic with exercise in male rats. METHODS Long⁻Evans rats (n = 56) were assigned to be exercise trained (+E) by running on a treadmill three days per week at a moderate intensity or to act as sedentary controls with normal activity. After the baseline physical performance was evaluated by recording run time to exhaustion, half of the animals in each group were fed ad libitum for three months a purified diet formulated to mimic the Daniel Fast (DF) or a Western Diet (WD). Physical performance was evaluated again at the end of month 3, and body composition was assessed using dual-energy x-ray absorptiometry. Blood was collected for measurements of lipids, oxidative stress, and inflammatory biomarkers. RESULTS Physical performance at the end of month 3 was higher compared to baseline for both exercise groups (p < 0.05), with a greater percent increase in the DF + E group (99%) than in the WD + E group (51%). Body fat was lower in DF than in WD groups at the end of month 3 (p < 0.05). Blood triglycerides, cholesterol, malondialdehyde, and advanced oxidation protein products were significantly lower in the DF groups than in the WD groups (p < 0.05). No significant differences were noted in cytokines levels between the groups (p > 0.05), although IL-1β and IL-10 were elevated three-fold and two-fold in the rats fed the WD compared to the DF rats, respectively. CONCLUSIONS Compared to a WD, a purified diet that mimics the vegan Daniel Fast provides significant anthropometric and metabolic benefits to rats, while possibly acting synergistically with exercise training to improve physical performance. These findings highlight the importance of macronutrient composition and quality in the presence of ad libitum food intake.
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Zhou J, Wang D, Luo X, Jia X, Li M, Laudon M, Zhang R, Jia Z. Melatonin Receptor Agonist Piromelatine Ameliorates Impaired Glucose Metabolism in Chronically Stressed Rats Fed a High-Fat Diet. J Pharmacol Exp Ther 2017; 364:55-69. [DOI: 10.1124/jpet.117.243998] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/19/2017] [Accepted: 10/06/2017] [Indexed: 01/04/2023] Open
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Neu-P11, a novel MT1/MT2 agonist, reverses diabetes by suppressing the hypothalamic-pituitary-adrenal axis in rats. Eur J Pharmacol 2017; 812:225-233. [PMID: 28687198 DOI: 10.1016/j.ejphar.2017.07.001] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/29/2016] [Revised: 06/19/2017] [Accepted: 07/03/2017] [Indexed: 12/15/2022]
Abstract
Excessive glucocorticoid (GC) in type 2 diabetes mellitus (T2DM) reduces insulin sensitivity, impairs β-cell function, increases gluconeogenesis and glycogenolysis, impairs glucose uptake and metabolism, and reduces the insulinotropic effects of glucagon-like peptide 1. Melatonin, which serves as a physiological regulator of the hypothalamic-pituitary-adrenal (HPA) axis, has been suggested to have anti-diabetic effects. The objective of the present study was to investigate the effect of the MT1/MT2 melatonin agonist Neu-P11 on glucose and lipid metabolism in T2DM rats induced by a high fat diet combined with low doses of streptozotocin. T2DM rats were intragastrically administered melatonin (20mg/kg), Neu-P11 (20, 10, 5mg/kg), or a vehicle for 4 weeks. The results showed that the increased food intake, water consumption, hyperglycemia, glucose intolerance, and insulin resistance in T2DM rats were all improved by Neu-P11 treatment. Neu-P11 increased GC receptor expression and suppressed 11β-hydroxysteroid dehydrogenase 1 activity in the hippocampus by enhancing GC sensitivity and HPA feedback, thus decreasing the high GC levels. Transcript levels of the glucose metabolism-related genes peroxisome proliferator-activated receptor-γ, glucose transporter type-4, and adiponectin in adipose tissue were significantly increased after Neu-P11 treatment, while leptin mRNA was significantly decreased. Furthermore, MT1 and MT2 protein levels were enhanced by Neu-P11. These data suggest that normalization of the hyperactivated HPA axis by melatonin and Neu-P11 in T2DM regulates metabolic profiles and insulin sensitivity, which may attenuate insulin resistance and glucose homeostasis. Because Neu-P11 has superior pharmacokinetics and a longer half-life than melatonin, it might be beneficial in treating obesity and T2DM.
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19
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Kjøbsted R, Wojtaszewski JFP, Treebak JT. Role of AMP-Activated Protein Kinase for Regulating Post-exercise Insulin Sensitivity. ACTA ACUST UNITED AC 2017; 107:81-126. [PMID: 27812978 DOI: 10.1007/978-3-319-43589-3_5] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Abstract
Skeletal muscle insulin resistance precedes development of type 2 diabetes (T2D). As skeletal muscle is a major sink for glucose disposal, understanding the molecular mechanisms involved in maintaining insulin sensitivity of this tissue could potentially benefit millions of people that are diagnosed with insulin resistance. Regular physical activity in both healthy and insulin-resistant individuals is recognized as the single most effective intervention to increase whole-body insulin sensitivity and thereby positively affect glucose homeostasis. A single bout of exercise has long been known to increase glucose disposal in skeletal muscle in response to physiological insulin concentrations. While this effect is identified to be restricted to the previously exercised muscle, the molecular basis for an apparent convergence between exercise- and insulin-induced signaling pathways is incompletely known. In recent years, we and others have identified the Rab GTPase-activating protein, TBC1 domain family member 4 (TBC1D4) as a target of key protein kinases in the insulin- and exercise-activated signaling pathways. Our working hypothesis is that the AMP-activated protein kinase (AMPK) is important for the ability of exercise to insulin sensitize skeletal muscle through TBC1D4. Here, we aim to provide an overview of the current available evidence linking AMPK to post-exercise insulin sensitivity.
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Affiliation(s)
- Rasmus Kjøbsted
- Novo Nordisk Foundation Center for Basic Metabolic Research, Section of Integrative Physiology, Faculty of Health and Medical Sciences, University of Copenhagen, Blegdamsvej 3b, 2200, Copenhagen, Denmark
- Section of Molecular Physiology, Department of Nutrition, Exercise and Sports, Faculty of Science, University of Copenhagen, 2100, Copenhagen, Denmark
| | - Jørgen F P Wojtaszewski
- Section of Molecular Physiology, Department of Nutrition, Exercise and Sports, Faculty of Science, University of Copenhagen, 2100, Copenhagen, Denmark
| | - Jonas T Treebak
- Novo Nordisk Foundation Center for Basic Metabolic Research, Section of Integrative Physiology, Faculty of Health and Medical Sciences, University of Copenhagen, Blegdamsvej 3b, 2200, Copenhagen, Denmark.
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20
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TAKAHASHI Y, MATSUNAGA Y, TAMURA Y, TERADA S, HATTA H. Pre-Exercise High-Fat Diet for 3 Days Affects Post-Exercise Skeletal Muscle Glycogen Repletion. J Nutr Sci Vitaminol (Tokyo) 2017; 63:323-330. [DOI: 10.3177/jnsv.63.323] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
Affiliation(s)
| | | | - Yuki TAMURA
- Department of Sports Sciences, The University of Tokyo
| | - Shin TERADA
- Department of Sports Sciences, The University of Tokyo
| | - Hideo HATTA
- Department of Sports Sciences, The University of Tokyo
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21
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Ghorbanzadeh V, Mohammadi M, Dariushnejad H, Chodari L, Mohaddes G. Effects of crocin and voluntary exercise, alone or combined, on heart VEGF-A and HOMA-IR of HFD/STZ induced type 2 diabetic rats. J Endocrinol Invest 2016; 39:1179-86. [PMID: 27094045 DOI: 10.1007/s40618-016-0456-2] [Citation(s) in RCA: 18] [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] [Received: 10/21/2015] [Accepted: 03/07/2016] [Indexed: 12/13/2022]
Abstract
BACKGROUND Hyperglycemia is the main risk factor for microvascular complications in type 2 diabetes. Crocin and voluntary exercise have anti-hyperglycemic effects in diabetes. In this research, we evaluated the effects of crocin and voluntary exercise alone or combined on glycemia control and heart level of VEGF-A. MATERIALS AND METHODS Animals were divided into eight groups as: control (con), diabetes (Dia), crocin (Cro), voluntary exercise (Exe), crocin and voluntary exercise (Cro-Exe), diabetic-crocin (Dia-Cro), diabetic-voluntary exercise (Dia-Exe), diabetic-crocin-voluntary exercise (Dia-Cro-Exe). Type 2 diabetes was induced by a high-fat diet (4 weeks) and injection of streptozotocin (STZ) (i.p, 35 mg/kg). Animals received oral administration of crocin (50 mg/kg) or performed voluntary exercise alone or together for 8 weeks. Oral glucose tolerance test (OGTT) was performed on overnight fasted control, diabetic and treated rats after 8 weeks of treatment. Then, serum insulin and heart VEGF-A protein levels were measured. RESULTS Crocin combined with voluntary exercise significantly decreased blood glucose levels (p < 0.001) and insulin resistance (HOMA-IR) (p < 0.001) compared to diabetic group. VEGF-A level was significantly (p < 0.01) lower in Dia group compared to control group. The combination of crocin and voluntary exercise significantly enhanced VEGF-A protein levels in Dia-Cro-Exe and Cro-Exe group compared to diabetic and control groups, respectively; p < 0.001 and p < 0.05. DISCUSSION Crocin combined with voluntary exercise improved insulin resistance (HOMA-IR) and reduced glucose levels in diabetic rats. Since both crocin and voluntary exercise can increase VEGF-A protein expression in heart tissue, they probably are able to increase angiogenesis in diabetic animals.
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MESH Headings
- Animals
- Biomarkers/metabolism
- Carotenoids/pharmacology
- Combined Modality Therapy
- Diabetes Mellitus, Experimental/etiology
- Diabetes Mellitus, Experimental/metabolism
- Diabetes Mellitus, Experimental/therapy
- Diabetes Mellitus, Type 2/etiology
- Diabetes Mellitus, Type 2/metabolism
- Diabetes Mellitus, Type 2/therapy
- Diet, High-Fat/adverse effects
- Disease Models, Animal
- Enzyme-Linked Immunosorbent Assay
- Glucose/administration & dosage
- Glucose Tolerance Test
- Heart/drug effects
- Heart/physiopathology
- Insulin Resistance
- Male
- Physical Conditioning, Animal
- Rats
- Rats, Wistar
- Vascular Endothelial Growth Factor A/metabolism
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Affiliation(s)
- V Ghorbanzadeh
- Drug Applied Research Center of Tabriz University of Medical Sciences, Tabriz, Iran
| | - M Mohammadi
- Drug Applied Research Center of Tabriz University of Medical Sciences, Tabriz, Iran
| | - H Dariushnejad
- Drug Applied Research Center of Tabriz University of Medical Sciences, Tabriz, Iran
| | - L Chodari
- Drug Applied Research Center of Tabriz University of Medical Sciences, Tabriz, Iran
| | - G Mohaddes
- Neuroscience Research Centre of Tabriz University of Medical Sciences, 5166614766, Tabriz, Iran.
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22
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Lycium barbarum polysaccharides ameliorates renal injury and inflammatory reaction in alloxan-induced diabetic nephropathy rabbits. Life Sci 2016; 157:82-90. [DOI: 10.1016/j.lfs.2016.05.045] [Citation(s) in RCA: 44] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/18/2015] [Revised: 05/26/2016] [Accepted: 05/31/2016] [Indexed: 12/28/2022]
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Betik AC, Aguila J, McConell GK, McAinch AJ, Mathai ML. Tocotrienols and Whey Protein Isolates Substantially Increase Exercise Endurance Capacity in Diet -Induced Obese Male Sprague-Dawley Rats. PLoS One 2016; 11:e0152562. [PMID: 27058737 PMCID: PMC4825941 DOI: 10.1371/journal.pone.0152562] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/28/2015] [Accepted: 03/16/2016] [Indexed: 12/16/2022] Open
Abstract
Background and Aims Obesity and impairments in metabolic health are associated with reductions in exercise capacity. Both whey protein isolates (WPIs) and vitamin E tocotrienols (TCTs) exert favorable effects on obesity-related metabolic parameters. This research sought to determine whether these supplements improved exercise capacity and increased glucose tolerance in diet-induced obese rats. Methods Six week old male rats (n = 35) weighing 187 ± 32g were allocated to either: Control (n = 9), TCT (n = 9), WPI (n = 8) or TCT + WPI (n = 9) and placed on a high-fat diet (40% of energy from fat) for 10 weeks. Animals received 50mg/kg body weight and 8% of total energy intake per day of TCTs and/or WPIs respectively. Food intake, body composition, glucose tolerance, insulin sensitivity, exercise capacity, skeletal muscle glycogen content and oxidative enzyme activity were determined. Results Both TCT and WPI groups ran >50% longer (2271 ± 185m and 2195 ± 265m respectively) than the Control group (1428 ± 139m) during the run to exhaustion test (P<0.05), TCT + WPI did not further improve exercise endurance (2068 ± 104m). WPIs increased the maximum in vitro activity of beta-hydroxyacyl-CoA in the soleus muscle (P<0.05 vs. Control) but not in the plantaris. Citrate synthase activity was not different between groups. Neither supplement had any effect on weight gain, adiposity, glucose tolerance or insulin sensitivity. Conclusion Ten weeks of both TCTs and WPIs increased exercise endurance by 50% in sedentary, diet-induced obese rats. These positive effects of TCTs and WPIs were independent of body weight, adiposity or glucose tolerance.
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Affiliation(s)
- Andrew C. Betik
- Centre for Chronic Disease, College of Health and Biomedicine, Victoria University, Melbourne, Victoria, Australia
- Institute of Sport, Exercise and Active Living (ISEAL), Victoria University, Melbourne, Victoria, Australia
- * E-mail:
| | - Jay Aguila
- Centre for Chronic Disease, College of Health and Biomedicine, Victoria University, Melbourne, Victoria, Australia
| | - Glenn K. McConell
- Centre for Chronic Disease, College of Health and Biomedicine, Victoria University, Melbourne, Victoria, Australia
- Institute of Sport, Exercise and Active Living (ISEAL), Victoria University, Melbourne, Victoria, Australia
| | - Andrew J. McAinch
- Centre for Chronic Disease, College of Health and Biomedicine, Victoria University, Melbourne, Victoria, Australia
- Institute of Sport, Exercise and Active Living (ISEAL), Victoria University, Melbourne, Victoria, Australia
| | - Michael L. Mathai
- Centre for Chronic Disease, College of Health and Biomedicine, Victoria University, Melbourne, Victoria, Australia
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Sayin F, Buyukbas S, Basarali M, Alp H, Toy H, Ugurcu V. Effects of Silybum marianum Extract on High-Fat Diet Induced Metabolic Disorders in Rats. POL J FOOD NUTR SCI 2016. [DOI: 10.1515/pjfns-2015-0014] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022] Open
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Cartee GD. Mechanisms for greater insulin-stimulated glucose uptake in normal and insulin-resistant skeletal muscle after acute exercise. Am J Physiol Endocrinol Metab 2015; 309:E949-59. [PMID: 26487009 PMCID: PMC4816200 DOI: 10.1152/ajpendo.00416.2015] [Citation(s) in RCA: 89] [Impact Index Per Article: 9.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/16/2015] [Accepted: 10/14/2015] [Indexed: 02/08/2023]
Abstract
Enhanced skeletal muscle and whole body insulin sensitivity can persist for up to 24-48 h after one exercise session. This review focuses on potential mechanisms for greater postexercise and insulin-stimulated glucose uptake (ISGU) by muscle in individuals with normal or reduced insulin sensitivity. A model is proposed for the processes underlying this improvement; i.e., triggers initiate events that activate subsequent memory elements, which store information that is relayed to mediators, which translate memory into action by controlling an end effector that directly executes increased insulin-stimulated glucose transport. Several candidates are potential triggers or memory elements, but none have been conclusively verified. Regarding potential mediators in both normal and insulin-resistant individuals, elevated postexercise ISGU with a physiological insulin dose coincides with greater Akt substrate of 160 kDa (AS160) phosphorylation without improved proximal insulin signaling at steps from insulin receptor binding to Akt activity. Causality remains to be established between greater AS160 phosphorylation and improved ISGU. The end effector for normal individuals is increased GLUT4 translocation, but this remains untested for insulin-resistant individuals postexercise. Following exercise, insulin-resistant individuals can attain ISGU values similar to nonexercising healthy controls, but after a comparable exercise protocol performed by both groups, ISGU for the insulin-resistant group has been consistently reported to be below postexercise values for the healthy group. Further research is required to fully understand the mechanisms underlying the improved postexercise ISGU in individuals with normal or subnormal insulin sensitivity and to explain the disparity between these groups after similar exercise.
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Affiliation(s)
- Gregory D Cartee
- Muscle Biology Laboratory, School of Kinesiology, Department of Molecular and Integrative Physiology, and Institute of Gerontology, University of Michigan, Ann Arbor, Michigan
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Jemaa HB, Khlifi S, Hmed HB, Karmous I, Benzarti A, Elati J, Aouidet A. Antidiabetic, Antihyperlipidemic and Antioxidant Effects of Artemisia herba alba Extract on Experimental Diabetes. INT J PHARMACOL 2015. [DOI: 10.3923/ijp.2015.552.560] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
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Hong YH, Betik AC, Premilovac D, Dwyer RM, Keske MA, Rattigan S, McConell GK. No effect of NOS inhibition on skeletal muscle glucose uptake during in situ hindlimb contraction in healthy and diabetic Sprague-Dawley rats. Am J Physiol Regul Integr Comp Physiol 2015; 308:R862-71. [DOI: 10.1152/ajpregu.00412.2014] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/06/2014] [Accepted: 03/10/2015] [Indexed: 11/22/2022]
Abstract
Nitric oxide (NO) has been shown to be involved in skeletal muscle glucose uptake during contraction/exercise, especially in individuals with Type 2 diabetes (T2D). To examine the potential mechanisms, we examined the effect of local NO synthase (NOS) inhibition on muscle glucose uptake and muscle capillary blood flow during contraction in healthy and T2D rats. T2D was induced in Sprague-Dawley rats using a combined high-fat diet (23% fat wt/wt for 4 wk) and low-dose streptozotocin injections (35 mg/kg). Anesthetized animals had one hindlimb stimulated to contract in situ for 30 min (2 Hz, 0.1 ms, 35 V) with the contralateral hindlimb rested. After 10 min, the NOS inhibitor, NG-nitro-l-arginine methyl ester (l-NAME; 5 μM) or saline was continuously infused into the femoral artery of the contracting hindlimb until the end of contraction. Surprisingly, there was no increase in skeletal muscle NOS activity during contraction in either group. Local NOS inhibition had no effect on systemic blood pressure or muscle contraction force, but it did cause a significant attenuation of the increase in femoral artery blood flow in control and T2D rats. However, NOS inhibition did not attenuate the increase in muscle capillary recruitment during contraction in these rats. Muscle glucose uptake during contraction was significantly higher in T2D rats compared with controls but, unlike our previous findings in hooded Wistar rats, NOS inhibition had no effect on glucose uptake during contraction. In conclusion, NOS inhibition did not affect muscle glucose uptake during contraction in control or T2D Sprague-Dawley rats, and this may have been because there was no increase in NOS activity during contraction.
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Affiliation(s)
- Yet Hoi Hong
- College of Health and Biomedicine, Victoria University, Melbourne, Victoria, Australia
- Institute of Sport, Exercise and Active Living, Victoria University, Melbourne, Victoria, Australia
- Department of Physiology, Faculty of Medicine, University of Malaya, Kuala Lumpur, Malaysia
| | - Andrew C. Betik
- College of Health and Biomedicine, Victoria University, Melbourne, Victoria, Australia
- Institute of Sport, Exercise and Active Living, Victoria University, Melbourne, Victoria, Australia
| | - Dino Premilovac
- Menzies Research Institute Tasmania, University of Tasmania, Hobart, Tasmania, Australia; and
| | - Renee M. Dwyer
- Menzies Research Institute Tasmania, University of Tasmania, Hobart, Tasmania, Australia; and
- School of Medicine, University of Tasmania, Hobart, Tasmania, Australia
| | - Michelle A. Keske
- Menzies Research Institute Tasmania, University of Tasmania, Hobart, Tasmania, Australia; and
| | - Stephen Rattigan
- Menzies Research Institute Tasmania, University of Tasmania, Hobart, Tasmania, Australia; and
| | - Glenn K. McConell
- College of Health and Biomedicine, Victoria University, Melbourne, Victoria, Australia
- Institute of Sport, Exercise and Active Living, Victoria University, Melbourne, Victoria, Australia
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Sharma N, Wang H, Arias EB, Castorena CM, Cartee GD. Mechanisms for independent and combined effects of calorie restriction and acute exercise on insulin-stimulated glucose uptake by skeletal muscle of old rats. Am J Physiol Endocrinol Metab 2015; 308:E603-12. [PMID: 25670830 PMCID: PMC4385876 DOI: 10.1152/ajpendo.00618.2014] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/30/2014] [Accepted: 02/03/2015] [Indexed: 12/27/2022]
Abstract
Either calorie restriction [CR; consuming 60-65% of ad libitum (AL) intake] or acute exercise can independently improve insulin sensitivity in old age, but their combined effects on muscle insulin signaling and glucose uptake have previously been unknown. Accordingly, we assessed the independent and combined effects of CR (beginning at 14 wk old) and acute exercise (3-4 h postexercise) on insulin signaling and glucose uptake in insulin-stimulated epitrochlearis muscles from 30-mo-old rats. Either CR alone or exercise alone vs. AL sedentary controls induced greater insulin-stimulated glucose uptake. Combined CR and exercise vs. either treatment alone caused an additional increase in insulin-stimulated glucose uptake. Either CR or exercise alone vs. AL sedentary controls increased Akt Ser(473) and Akt Thr(308) phosphorylation. Combined CR and exercise further elevated Akt phosphorylation on both sites. CR alone, but not exercise alone, vs. AL sedentary controls significantly increased Akt substrate of 160 kDa (AS160) Ser(588) and Thr(642) phosphorylation. Combined CR and exercise did not further enhance AS160 phosphorylation. Exercise alone, but not CR alone, modestly increased GLUT4 abundance. Combined CR and exercise did not further elevate GLUT4 content. These results suggest that CR or acute exercise independently increases insulin-stimulated glucose uptake via overlapping (greater Akt phosphorylation) and distinct (greater AS160 phosphorylation for CR, greater GLUT4 for exercise) mechanisms. Our working hypothesis is that greater insulin-stimulated glucose uptake in the combined CR and exercise group vs. CR or exercise alone relies on greater Akt activation, leading to greater phosphorylation of one or more Akt substrates other than AS160.
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Affiliation(s)
- Naveen Sharma
- Muscle Biology Laboratory, School of Kinesiology, University of Michigan, Ann Arbor, Michigan; School of Health Sciences, Central Michigan University, Mount Pleasant, Michigan
| | - Haiyan Wang
- Muscle Biology Laboratory, School of Kinesiology, University of Michigan, Ann Arbor, Michigan; College of Physical Education and Health, East China Normal University, Shanghai, China
| | - Edward B Arias
- Muscle Biology Laboratory, School of Kinesiology, University of Michigan, Ann Arbor, Michigan
| | - Carlos M Castorena
- Muscle Biology Laboratory, School of Kinesiology, University of Michigan, Ann Arbor, Michigan
| | - Gregory D Cartee
- Muscle Biology Laboratory, School of Kinesiology, University of Michigan, Ann Arbor, Michigan; Department of Molecular and Integrative Physiology, University of Michigan, Ann Arbor, Michigan; and Institute of Gerontology, University of Michigan, Ann Arbor, Michigan
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Iwabe M, Kawamoto E, Koshinaka K, Kawanaka K. Increased postexercise insulin sensitivity is accompanied by increased AS160 phosphorylation in slow-twitch soleus muscle. Physiol Rep 2014; 2:2/12/e12162. [PMID: 25501433 PMCID: PMC4332192 DOI: 10.14814/phy2.12162] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022] Open
Abstract
A single bout of exercise can enhance insulin‐stimulated glucose uptake in both
fast‐twitch (type II) and slow‐twitch (type I) skeletal muscle for several hours
postexercise. Akt substrate of 160 kDa (AS160) is most distal insulin signaling proteins that have
been proposed to contribute to the postexercise enhancement of insulin action in fast‐twitch
muscle. In this study, we examined whether the postexercise increase in insulin action of glucose
uptake in slow‐twitch muscle is accompanied by increased phosphorylation of AS160 and its
paralog TBC1D1. Male Wistar rats (~1‐month‐old) were exercised on a treadmill for 180
min (9 m/min). Insulin (50 μU/mL)‐stimulated glucose uptake was
increased at 2 h after cessation of exercise in soleus muscle composed of predominantly
slow‐twitch fibers. This postexercise increase in insulin action of glucose uptake was
accompanied by increased phosphorylation of AS160 (detected by phospho‐Thr642 and
phospho‐Ser588 antibody). On the other hand, prior exercise did not increase phosphorylation
of TBC1D1 (detected by phospho‐Thr590) at 2 h postexercise. These results suggest the
possibility that an enhancement in AS160 phosphorylation but not TBC1D1 phosphorylation is involved
with increased postexercise insulin action of glucose uptake in slow‐twitch muscle. In slow‐twitch soleus muscle, phosphorylation of AS160 Thr642 and Ser588 was increased
together with the enhanced insulin action of the glucose uptake at 2 h postexercise. The phosphosite
of TBC1D1 (Thr590), which is possibly important for insulin‐stimulated glucose uptake, did
not increase phosphorylation at 2 h postexercise. These results suggest that the increased
phosphorylation of AS160, but not TBC1D1, can account for the postexercise enhancement in the
insulin action of the glucose uptake in slow‐twitch muscle.
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Affiliation(s)
- Maiko Iwabe
- Department of Health and Nutrition, Niigata University of Health and Welfare, Niigata, Japan
| | - Emi Kawamoto
- Department of Health and Nutrition, Niigata University of Health and Welfare, Niigata, Japan
| | - Keiichi Koshinaka
- Department of Health and Nutrition, Niigata University of Health and Welfare, Niigata, Japan
| | - Kentaro Kawanaka
- Department of Health and Nutrition, Niigata University of Health and Welfare, Niigata, Japan
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Zhang Y, Ren C, Lu G, Mu Z, Cui W, Gao H, Wang Y. Anti-diabetic effect of mulberry leaf polysaccharide by inhibiting pancreatic islet cell apoptosis and ameliorating insulin secretory capacity in diabetic rats. Int Immunopharmacol 2014; 22:248-57. [DOI: 10.1016/j.intimp.2014.06.039] [Citation(s) in RCA: 78] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/08/2014] [Revised: 06/27/2014] [Accepted: 06/27/2014] [Indexed: 01/09/2023]
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Chen J, Li Q, Dong R, Gao H, Peng H, Wu Y. The effect of the Ras homolog gene family (Rho), member A/Rho associated coiled-coil forming protein kinase pathway in atrial fibrosis of type 2 diabetes in rats. Exp Ther Med 2014; 8:836-840. [PMID: 25120610 PMCID: PMC4113648 DOI: 10.3892/etm.2014.1843] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/24/2014] [Accepted: 06/17/2014] [Indexed: 12/24/2022] Open
Abstract
Diabetes mellitus promotes atrial structural remodeling, thereby producing atrial arrhythmogenicity. Atrial arrhythmia can substantially increase the risk of premature death. The aim of this study was to investigate the role of Ras homolog gene family, member A (RhoA)/Rho associated coiled-coil forming protein kinase (ROCK) in atrial fibrosis in diabetic hearts, and the effects of fasudil hydrochloride hydrate on atrial fibrosis. An eight-week-old male Sprague-Dawley rat model of type 2 diabetes was established using a high-fat diet combined with streptozotocin [30 mg/kg, once, intraperitoneal (i.p.)]. Animals were randomly divided into three groups: Control rats, untreated diabetic rats that received vehicle, and treated diabetic rats that received Rho kinase inhibitor fasudil hydrochloride hydrate (10 mg/kg/day, i.p., for 14 weeks). The morphological features of atrial fibrosis were observed using Masson staining. The mRNA expression levels of RhoA, ROCK1, ROCK2, type-I and type-III procollagen were assessed with quantitative polymerase chain reaction. The protein levels of RhoA, ROCK1 and ROCK2 were evaluated using western blot analysis. The atria of untreated diabetic rats showed evident atrial fibrosis as compared to the control rats; the mRNA expression levels of RhoA, ROCK1, ROCK2, type-I and type-III procollagen were upregulated; and the protein levels of RhoA, ROCK1 and ROCK2 were increased. The treatment with fasudil hydrochloride hydrate significantly reduced atrial fibrosis, mRNA levels of RhoA, ROCK1, ROCK2, type-I and type-III procollagen, and the protein levels of RhoA, ROCK1 and ROCK2. The results suggested that RhoA/ROCK was involved in atrial fibrosis, and that fasudil hydrochloride hydrate ameliorates atrial fibrosis through the RhoA/ROCK pathway in rats with type 2 diabetes.
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Affiliation(s)
- Jinling Chen
- Department of Cardiology, Beijing Friendship Hospital, Capital Medical University, Beijing 100050, P.R. China
| | - Qingqing Li
- Department of Cardiology, Beijing Friendship Hospital, Capital Medical University, Beijing 100050, P.R. China
| | - Ruiqing Dong
- Department of Cardiology, Beijing Friendship Hospital, Capital Medical University, Beijing 100050, P.R. China
| | - Huikuan Gao
- Department of Cardiology, Beijing Friendship Hospital, Capital Medical University, Beijing 100050, P.R. China
| | - Hui Peng
- Department of Cardiology, Beijing Friendship Hospital, Capital Medical University, Beijing 100050, P.R. China
| | - Yongquan Wu
- Department of Cardiology, Beijing Friendship Hospital, Capital Medical University, Beijing 100050, P.R. China
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Castorena CM, Arias EB, Sharma N, Cartee GD. Postexercise improvement in insulin-stimulated glucose uptake occurs concomitant with greater AS160 phosphorylation in muscle from normal and insulin-resistant rats. Diabetes 2014; 63:2297-308. [PMID: 24608437 PMCID: PMC4066340 DOI: 10.2337/db13-1686] [Citation(s) in RCA: 68] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Abstract
Earlier research on rats with normal insulin sensitivity demonstrated that acute exercise increased insulin-stimulated glucose uptake (GU) concomitant with greater phosphorylation of Akt substrate of 160 kDa (pAS160). Because mechanisms for exercise effects on GU in insulin-resistant muscle are unknown, our primary objective was to assess insulin-stimulated GU, proximal insulin signaling (insulin receptor [IR] tyrosine phosphorylation, IR substrate 1-phosphatidylinositol-3-kinase, and Akt phosphorylation and activity), and pAS160 in muscles from acutely exercised (one session) and sedentary rats fed either chow (low-fat diet [LFD]; normal insulin sensitivity) or a high-fat diet (HFD; for 2 weeks, insulin-resistant). At 3 h postexercise (3hPEX), isolated epitrochlearis muscles were used for insulin-stimulated GU and insulin signaling measurements. Although exercise did not enhance proximal signaling in either group, insulin-stimulated GU at 3hPEX exceeded respective sedentary control subjects (Sedentary) in both diet groups. Furthermore, insulin-stimulated GU for LFD-3hPEX was greater than HFD-3hPEX values. For HFD-3hPEX muscles, pAS160 exceeded HFD-Sedentary, but in muscle from LFD-3hPEX rats, pAS160 was greater still than HFD-3hPEX values. These results implicated pAS160 as a potential determinant of the exercise-induced elevation in insulin-stimulated GU for each diet group and also revealed pAS160 as a possible mediator of greater postexercise GU of insulin-stimulated muscles from the insulin-sensitive versus insulin-resistant group.
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Affiliation(s)
- Carlos M Castorena
- Muscle Biology Laboratory, School of Kinesiology, University of Michigan, Ann Arbor, MI
| | - Edward B Arias
- Muscle Biology Laboratory, School of Kinesiology, University of Michigan, Ann Arbor, MI
| | - Naveen Sharma
- Muscle Biology Laboratory, School of Kinesiology, University of Michigan, Ann Arbor, MISchool of Health Sciences, Central Michigan University, Mount Pleasant, MI
| | - Gregory D Cartee
- Muscle Biology Laboratory, School of Kinesiology, University of Michigan, Ann Arbor, MIDepartment of Molecular and Integrative Physiology, University of Michigan, Ann Arbor, MIInstitute of Gerontology, University of Michigan, Ann Arbor, MI
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The characterization of obese polycystic ovary syndrome rat model suitable for exercise intervention. PLoS One 2014; 9:e99155. [PMID: 24905232 PMCID: PMC4048306 DOI: 10.1371/journal.pone.0099155] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2013] [Accepted: 05/12/2014] [Indexed: 12/19/2022] Open
Abstract
OBJECTIVE To develop a new polycystic ovary syndrome (PCOS) rat model suitable for exercise intervention. METHOD Thirty six rats were randomly divided into three experimental groups: PCOS rats with high-fat diet (PF, n = 24), PCOS rats with ordinary diet (PO, n = 6), and control rats with ordinary diet (CO, n = 6). Two kinds of PCOS rat model were made by adjustment diet structure and testosterone injection for 28 days. After a successful animal model, PF model rats were randomly assigned to three groups: exercise with a continuation of high-fat diet (PF-EF, n = 6), sedentary with a continuation of high-fat diet (PF-SF, n = 6), exercise with an ordinary diet (PF-EO, n = 6). Fasting blood glucose (FBG) and insulin (FINS), estrogen (E2), progesterone (P), and testosterone (T) in serum were determined by RIA, and ovarian morphology was evaluated by Image-Pro plus 6.0. RESULTS Body weight, Lee index, FINS increased significantly in PF rat model. Serum levels of E2 and T were significantly higher in PF and PO than in CO. Ovary organ index and ovarian areas were significant lower in PF than in CO. After intervention for 2 weeks, the levels of 1 h postprandial blood glucose (PBG1), 2 h postprandial blood glucose (PBG2), FINS and the serum levels of T decreased significantly in PF-EF rats and PF-EO rats. The ratio of FBG/FINS was significant higher in PF-EO rats than in PF-SF rats. Ovarian morphology showed that the numbers of preantral follicles and atretic follicles decreased significantly, and the numbers of antral follicles and corpora lutea increased significantly in the rats of PF-EF and PF-EO. CONCLUSION By combination of high-fat diet and testosterone injection, the obese PCOS rat model is conformable with the lifestyle habits of fatty foods and insufficient exercise, and has metabolic and reproductive characteristics of human PCOS. This model can be applied to study exercise intervention.
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Zhao X, Zhang Y, Li X, Wang R, Jiao X. Variations of thioredoxin system contributes to increased susceptibility to apoptosis in cardiomyocytes of type 2 diabetic rats. Acta Biochim Biophys Sin (Shanghai) 2014; 46:318-29. [PMID: 24578161 DOI: 10.1093/abbs/gmu006] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023] Open
Abstract
Cardiac complications are the leading cause of death in diabetes. However, the mechanism of diabetes in inducing myocardial injury and apoptosis, and whether the thioredoxin (Trx) system is involved remain unclear. In this study, male Sprague-Dawley rats were randomly divided into two groups: the control and the diabetes groups, and then were randomly divided into five different timepoints (the 1st, 2nd, 4th, 12th, and 24th week). The results showed that diabetes-induced cardiac injury was enhanced in the type 2 diabetes rats, as evidenced by aggravated cardiac dysfunction, biochemical indicators, and increased myocardial apoptosis (TUNEL and caspase-3 activity). The activity of myocardial Trx and Trx reductase (TR) in diabetic rats was significantly decreased from the second week and continually aggravated with the disease progression. In diabetic rats, the mRNA expression of Trx1, Trx2, TR1, and TR2 was decreased first and then increased after the fourth week. Meanwhile, the protein expression of these Trx system members was significantly increased at the 12th week. Trx nitration was cleared, the Trx/ASK1 interaction was significantly decreased, and the activity of p38 was significantly enhanced in cardiac tissues at the 12th week. These results demonstrated that diabetes may cause myocardial injury and apoptosis, and the extent of which was accompanied with the development of the disease. The mechanism is associated with the development of diabetes and the decreased activity of Trx and TR. The reasons for decreased Trx activity may include: decrease of Trx and TR protein expression; nitration modification of Trx; and up-regulation of TXNIP expression.
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Affiliation(s)
- Xiaoqin Zhao
- Department of Physiology, Key Laboratory of Cellular Physiology, Shanxi Medical University, Taiyuan 030001, China
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Egawa T, Tsuda S, Oshima R, Goto K, Hayashi T. Activation of 5′AMP-activated protein kinase in skeletal muscle by exercise and phytochemicals. JOURNAL OF PHYSICAL FITNESS AND SPORTS MEDICINE 2014. [DOI: 10.7600/jpfsm.3.55] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
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Numao S, Kawano H, Endo N, Yamada Y, Konishi M, Takahashi M, Sakamoto S. Effects of a single bout of aerobic exercise on short-term low-carbohydrate/high-fat intake-induced postprandial glucose metabolism during an oral glucose tolerance test. Metabolism 2013; 62:1406-15. [PMID: 23764436 DOI: 10.1016/j.metabol.2013.05.005] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/15/2013] [Revised: 04/15/2013] [Accepted: 05/09/2013] [Indexed: 11/25/2022]
Abstract
OBJECTIVE A single bout of exercise can improve acute postprandial glucose metabolism aggravated by short-term low-carbohydrate/high-fat diet (HFD). The purpose of this study was to investigate the effect of a single bout of aerobic exercise on short-term HFD-induced postprandial glucose and incretin metabolism during an oral glucose tolerance test (OGTT). MATERIALS/METHODS Eleven healthy young men (age [mean±SE] 27±1 years; body mass index, 22±1 kg/m(2)) performed three, 3-day interventions in randomized order: (1) a normal diet (ND: ~22% fat), (2) an HFD (~69% fat) and (3) an HFD with a single bout of aerobic exercise (HFDEx). The exercise (50% peak oxygen consumption; ~200 kcal) was performed on the third day in HFDEx. An OGTT was performed after each 3-day dietary intervention. RESULTS The incremental area under the curve (iAUC) of plasma glucose levels during the OGTT was significantly higher in the HFD and HFDEx trials than in the ND trial (P=0.001). In addition, the iAUC of glucagon-like peptide-1 (GLP-1) level was significantly higher in the HFD trial than in the ND and HFDEx trials (P=0.04). The first-phase insulin secretion indexes were significantly lower in the HFD (P=0.01 and 0.002) and HFDEx trials (P=0.05 and 0.008) than in the ND trial. CONCLUSION A single bout of aerobic exercise did not improve the short-term HFD-induced aggravation of postprandial glucose and insulin metabolism during the OGTT. However, it did normalize the increased postprandial GLP-1 level induced by HFD.
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Affiliation(s)
- Shigeharu Numao
- Department of Health and Sports Sciences, Kyoto Pharmaceutical University; Waseda Institute for Sport Sciences.
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Dong Z, Chen CX. Effect of catalpol on diabetic nephropathy in rats. PHYTOMEDICINE : INTERNATIONAL JOURNAL OF PHYTOTHERAPY AND PHYTOPHARMACOLOGY 2013; 20:1023-1029. [PMID: 23746755 DOI: 10.1016/j.phymed.2013.04.007] [Citation(s) in RCA: 37] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/16/2013] [Revised: 03/19/2013] [Accepted: 04/19/2013] [Indexed: 06/02/2023]
Abstract
PURPOSE To investigate the effect of catalpol on diabetic nephropathy in rats. METHODS Male Sprague-Dawley rats were randomly divided into two groups and fed with normal pallet diet (NPD) or high-fat diet (HFD) for 4 weeks respectively. Then the HFD-fed rats were injected with 35 mg/kg streptozotocin (STZ) for establishing diabetic model. The diabetic rats were randomly divided into five groups: model group, model plus catalpol 30, 60, 120 mg/kg groups and model plus metformin 200 mg/kg group. The NPD-fed rats were randomly divided into two groups: normal control group and normal plus catalpol 60 mg/kg control group. After administration for 10 weeks, random blood glucose (RBG), glycated serum protein (GSP), 24h urinary protein excretion (UPE), serum creatinine (Scr), blood urea nitrogen (BUN), and kidney weight index (KWI) were determined. The kidney pathological changes were evaluated by periodic acid-Schiff (PAS) staining. The concentrations of angiotensin II (Ang II), transforming growth factor-β1 (TGF-β1), connective tissue growth factor (CTGF), fibronectin (FN), collagen type IV (Col IV) in renal cortex were determined. Real time RT-PCR was used to detect the mRNA expressions of TGF-β1 and CTGF. RESULTS Catalpol could significantly reduce the KWI, improve the kidney function and pathological change, decrease the tissue level of Ang II, TGF-β1, CTGF, FN, Col IV. Catalpol could also down regulate the mRNA expressions of TGF-β1 and CTGF in renal cortex. CONCLUSION Catalpol may have beneficial effects against diabetic nephropathy. The mechanisms may be related to reducing the extracellular matrix accumulation by restraining the expression of TGF-β1, CTGF and Ang II.
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Affiliation(s)
- Zhao Dong
- Department of Pharmacology, Shanghai University of Traditional Chinese Medicine, Shanghai 201203, PR China
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Xiao Y, Sharma N, Arias EB, Castorena CM, Cartee GD. A persistent increase in insulin-stimulated glucose uptake by both fast-twitch and slow-twitch skeletal muscles after a single exercise session by old rats. AGE (DORDRECHT, NETHERLANDS) 2013; 35:573-582. [PMID: 22286902 PMCID: PMC3636414 DOI: 10.1007/s11357-012-9383-0] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/11/2011] [Accepted: 01/12/2012] [Indexed: 05/31/2023]
Abstract
Exercise has been demonstrated to enhance subsequent insulin-stimulated glucose uptake (GU) by predominantly type II (fast-twitch) muscle of old rats, but previous research has not evaluated exercise effects on GU by type I (slow-twitch) muscle from old rats. Accordingly, we studied male Fischer 344/Brown Norway rats (24 months old) and determined GU (0, 100, 200, and 5,000 μU/ml insulin) of isolated soleus (predominantly type I) and epitrochlearis (predominantly type II) muscles after one exercise session. Epitrochlearis (100, 200, and 5,000 μU/ml insulin) and soleus (100 and 200 μU/ml insulin) GU were greater at 3-h postexercise vs. age-matched sedentary controls. Insulin receptor tyrosine phosphorylation (Tyr1162/1163) was unaltered by exercise in either muscle. Akt phosphorylation (pAkt) was greater for exercised vs. sedentary rats in the epitrochlearis (Ser473 and Thr308 with 100 and 200 μU/ml, respectively) and soleus (Ser473 with 200 μU/ml). AS160 phosphorylation (pAS160) was greater for exercised vs. sedentary rats in the epitrochlearis (Thr642 with 100 μU/ml), but not the soleus. Exercised vs. sedentary rats did not differ for total protein abundance of insulin receptor, Akt, AS160, or GLUT4 in either muscle. These results demonstrate that both predominantly type I and type II muscles from old rats are susceptible to exercise-induced improvement in insulin-mediated GU by mechanisms that are independent of enhanced insulin receptor tyrosine phosphorylation or altered abundance of important signaling proteins or GLUT4. Exercise-induced elevation in pAkt, and possibly pAS160, may contribute to this effect in the epitrochlearis of old rats, but other mechanisms are likely important for the soleus.
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Affiliation(s)
- Yuanyuan Xiao
- />Muscle Biology Laboratory, School of Kinesiology, University of Michigan, 401 Washtenaw Ave., Ann Arbor, MI 48109-2214 USA
| | - Naveen Sharma
- />Muscle Biology Laboratory, School of Kinesiology, University of Michigan, 401 Washtenaw Ave., Ann Arbor, MI 48109-2214 USA
| | - Edward B. Arias
- />Muscle Biology Laboratory, School of Kinesiology, University of Michigan, 401 Washtenaw Ave., Ann Arbor, MI 48109-2214 USA
| | - Carlos M. Castorena
- />Muscle Biology Laboratory, School of Kinesiology, University of Michigan, 401 Washtenaw Ave., Ann Arbor, MI 48109-2214 USA
| | - Gregory D. Cartee
- />Muscle Biology Laboratory, School of Kinesiology, University of Michigan, 401 Washtenaw Ave., Ann Arbor, MI 48109-2214 USA
- />Department of Molecular and Integrative Physiology, University of Michigan, Ann Arbor, MI 48109 USA
- />Institute of Gerontology, University of Michigan, Ann Arbor, MI 48109 USA
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Sundaram R, Naresh R, Shanthi P, Sachdanandam P. Modulatory effect of green tea extract on hepatic key enzymes of glucose metabolism in streptozotocin and high fat diet induced diabetic rats. PHYTOMEDICINE : INTERNATIONAL JOURNAL OF PHYTOTHERAPY AND PHYTOPHARMACOLOGY 2013; 20:577-584. [PMID: 23453307 DOI: 10.1016/j.phymed.2013.01.006] [Citation(s) in RCA: 43] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/23/2012] [Revised: 12/14/2012] [Accepted: 01/26/2013] [Indexed: 06/01/2023]
Abstract
The study was undertaken to evaluate the antidiabetic effect of green tea extract on carbohydrate metabolic key enzymes in control and streptozotocin high fat diet -induced diabetic rats. The daily oral treatment of green tea extract (300 mg/kg body weight) to diabetic rats for 30 days resulted in a significant reduction in the levels of plasma glucose, glycosylated hemoglobin (HbA1c) and increase in the levels of insulin and hemoglobin. The altered activities of the key enzymes of carbohydrate metabolism such as hexokinase, pyruvate kinase, lactate dehydrogenase, glucose-6-phosphatase, fructose-1,6-bisphosphatase, glucose-6-phosphate dehydrogenase, glycogen synthase and glycogen phosphorylase in liver of diabetic rats were significantly reverted to near normal levels by the administration of green tea extract. Further, green tea extract administration to diabetic rats improved muscle and hepatic glycogen content suggesting the antihyperglycemic potential of green tea extract in diabetic rats. The obtained results were compared with metformin, a standard oral hypoglycemic drug. Thus, this study indicates that the administration of green tea extract to diabetic rats resulted in alterations in the metabolism of glucose with subsequent reduction in plasma glucose levels.
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Affiliation(s)
- Ramalingam Sundaram
- Department of Medical Biochemistry, Dr ALM P-G, Institute of Basic Medical Sciences, University of Madras, Taramani Campus, Chennai, Tamil Nadu, India
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Abo-elmatty DM, Essawy SS, Badr JM, Sterner O. Antioxidant and anti-inflammatory effects of Urtica pilulifera extracts in type 2 diabetic rats. JOURNAL OF ETHNOPHARMACOLOGY 2013; 145:269-277. [PMID: 23159471 DOI: 10.1016/j.jep.2012.11.002] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/28/2012] [Revised: 10/27/2012] [Accepted: 11/02/2012] [Indexed: 06/01/2023]
Abstract
ETHNOPHARMACOLOGICAL RELEVANCE "Urtica pilulifera has been traditionally used in Egyptian system as an herbal remedy to be a diuretic, antiasthmatic, anti-inflammatory, hypoglycemic, hemostatic, antidandruff and astringent" AIM OF THE STUDY To evaluate the potential effects of ethyl acetate (EA), chloroform (CHLOR) and hexane (HEXA) extracts of Urtica piluliferaas oral anti-diabetic agents as well as to evaluate their possible anti-oxidant and anti-inflammatory effects in type 2 diabetic rat model. MATERIAL AND METHODS Type 2 diabetes was induced by a high fat diet and low dose streptozotocin (STZ). Diabetic adult male albino rats were allocated into groups and treated according to the following schedule; Pioglitazone HCL (PIO), EA, CHLOR and HEXA extracts of Urtica pilulifera at two doses of 250 and 500 mg/kg were used. In addition, a normal control group and a diabetic control one were used for comparison. Blood glucose, insulin resistance, antioxidant enzymes, 8-hydroxy-2-deoxyguanosine (8-OHdG) as well as C-reactive protein and tumor necrosis factor-α levels were evaluated. RESULTS EA and CHLOR extracts of Urtica pilulifera exhibited a significant hypoglycemia associated with antioxidant and anti-inflammatory effects in diabetic rats; however, HEXA extract showed no beneficial effect. These activities are responsible, at least partly, for improvements that have been seen in hyperglycemia and insulin resistance of diabetic rats. CONCLUSION Our results encourage the traditional use of Urtica pilulifera extract as an antioxidant and anti-inflammatory agent as an additional therapy of diabetes.
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Affiliation(s)
- Dina M Abo-elmatty
- Department of Pharmacology, Faculty of Medicine, Suez Canal University, Ismailia, 41522, Egypt
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Yi X, Cao S, Chang B, Zhao D, Gao H, Wan Y, Shi J, Wei W, Guan Y. Effects of acute exercise and chronic exercise on the liver leptin-AMPK-ACC signaling pathway in rats with type 2 diabetes. J Diabetes Res 2013; 2013:946432. [PMID: 24455748 PMCID: PMC3877642 DOI: 10.1155/2013/946432] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/13/2013] [Revised: 11/01/2013] [Accepted: 11/01/2013] [Indexed: 01/06/2023] Open
Abstract
AIM To investigate the effects of acute and chronic exercise on glucose and lipid metabolism in liver of rats with type 2 diabetes caused by a high fat diet and low dose streptozotocin (STZ). METHODS Animals were classified into control (CON), diabetes (DC), diabetic chronic exercise (DCE), and diabetic acute exercise (DAE) groups. RESULTS Compared to CON, the leptin levels in serum and liver and ACC phosphorylation were significantly higher in DC, but the levels of liver leptin receptor, AMPK α 1/2, AMPK α 1, and ACC proteins expression and phosphorylation were significantly lower in DC. In addition, the levels of liver glycogen reduced significantly, and the levels of TG and FFA increased significantly in DC compared to CON. Compared to DC, the levels of liver AMPK α 1/2, AMPK α 2, AMPK α 1, and ACC phosphorylation significantly increased in DCE and DAE. However, significant increase of the level of liver leptin receptor and glycogen as well as significant decrease of the level of TG and FFA were observed only in DEC. CONCLUSION Our study demonstrated that both acute and chronic exercise indirectly activated the leptin-AMPK-ACC signaling pathway and increased insulin sensitivity in the liver of type 2 diabetic rats. However, only chronic and long-term exercise improved glucose and lipid metabolism of the liver.
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Affiliation(s)
- Xuejie Yi
- Department of Biochemistry and Molecular Biology, College of Basic Medical Sciences, China Medical University, Shenyang 110001, China
- Department of Exercise Science, Shenyang Sport University, Shenyang, China
| | - Shicheng Cao
- Department of Sport Medicine, College of Basic Medical Sciences, China Medical University, Shenyang, China
| | - Bo Chang
- Department of Exercise Science, Shenyang Sport University, Shenyang, China
| | - Dalin Zhao
- Department of Exercise Science, Shenyang Sport University, Shenyang, China
| | - Haining Gao
- Department of Exercise Science, Shenyang Sport University, Shenyang, China
| | - Yihan Wan
- Department of Exercise Science, Shenyang Sport University, Shenyang, China
| | - Jiaojiao Shi
- Department of Exercise Science, Shenyang Sport University, Shenyang, China
| | - Wei Wei
- Department of Exercise Science, Shenyang Sport University, Shenyang, China
| | - Yifu Guan
- Department of Biochemistry and Molecular Biology, College of Basic Medical Sciences, China Medical University, Shenyang 110001, China
- *Yifu Guan:
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Modified high-sucrose diet-induced abdominally obese and normal-weight rats developed high plasma free fatty acid and insulin resistance. OXIDATIVE MEDICINE AND CELLULAR LONGEVITY 2012; 2012:374346. [PMID: 23320128 PMCID: PMC3540965 DOI: 10.1155/2012/374346] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 06/29/2012] [Revised: 10/31/2012] [Accepted: 11/26/2012] [Indexed: 02/05/2023]
Abstract
Introduction. Metabolically obese but normal-weight (MONW) individuals have metabolic features of overt obesity, and abdominal adiposity is common in them. Animal models of MONW individuals are lacking. We aimed to develop an abdominally obese and normal-weight (AONW) rat model. Methods and Results. Young male Sprague-Dawley rats were fed chow or a modified high-sucrose (HS) diet for 20 weeks. The HS diet induced increased visceral adipose tissue without increased body weight, reduced glucose disposal rates, and increased hepatic glucose output during the hyperinsulinemic-euglycemic clamp, increased plasma glucose during the intraperitoneal glucose tolerance test, and increased plasma free fatty acids. Hepatic lipidosis and hepatocyte mitochondria swelling were found in HS rats through light microscopy and transmission electron microscopy; similar impairments were not observed in muscle. RT-PCR showed that mRNA expression of uncoupling protein 3 and peroxisome proliferator-activated receptor-gamma coactivator 1α increased in muscle of HS rats, while expression of mitochondrial transcription factor A, glucose transporter type 4, and insulin receptor substrate-1 did not change significantly. Conclusion. AONW rats developed metabolic disorders seen in MONW individuals. Steatosis, mitochondrial morphologic changes, and insulin resistance were more serious in liver than in muscle. Genes involved in fatty acid metabolism and mitochondrial function changed in less impaired muscle.
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Cao S, Li B, Yi X, Chang B, Zhu B, Lian Z, Zhang Z, Zhao G, Liu H, Zhang H. Effects of exercise on AMPK signaling and downstream components to PI3K in rat with type 2 diabetes. PLoS One 2012; 7:e51709. [PMID: 23272147 PMCID: PMC3521695 DOI: 10.1371/journal.pone.0051709] [Citation(s) in RCA: 40] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2012] [Accepted: 11/05/2012] [Indexed: 01/31/2023] Open
Abstract
Exercise can increase skeletal muscle sensitivity to insulin, improve insulin resistance and regulate glucose homeostasis in rat models of type 2 diabetes. However, the potential mechanism remains poorly understood. In this study, we established a male Sprague–Dawley rat model of type 2 diabetes, with insulin resistance and β cell dysfunction, which was induced by a high-fat diet and low-dose streptozotocin to replicate the pathogenesis and metabolic characteristics of type 2 diabetes in humans. We also investigated the possible mechanism by which chronic and acute exercise improves metabolism, and the phosphorylation and expression of components of AMP-activated protein kinase (AMPK) and downstream components of phosphatidylinositol 3-kinase (PI3K) signaling pathways in the soleus. As a result, blood glucose, triglyceride, total cholesterol, and free fatty acid were significantly increased, whereas insulin level progressively declined in diabetic rats. Interestingly, chronic and acute exercise reduced blood glucose, increased phosphorylation and expression of AMPKα1/2 and the isoforms AMPKα1 and AMPKα2, and decreased phosphorylation and expression of AMPK substrate, acetyl CoA carboxylase (ACC). Chronic exercise upregulated phosphorylation and expression of AMPK upstream kinase, LKB1. But acute exercise only increased LKB1 expression. In particular, exercise reversed the changes in protein kinase C (PKC)ζ/λ phosphorylation, and PKCζ phosphorylation and expression. Additionally, exercise also increased protein kinase B (PKB)/Akt1, Akt2 and GLUT4 expression, but AS160 protein expression was unchanged. Chronic exercise elevated Akt (Thr308) and (Ser473) and AS160 phosphorylation. Finally, we found that exercise increased peroxisome proliferator-activated receptor-γ coactivator 1 (PGC1) mRNA expression in the soleus of diabetic rats. These results indicate that both chronic and acute exercise influence the phosphorylation and expression of components of the AMPK and downstream to PIK3 (aPKC, Akt), and improve GLUT4 trafficking in skeletal muscle. These data help explain the mechanism how exercise regulates glucose homeostasis in diabetic rats.
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Affiliation(s)
- Shicheng Cao
- Department of Sport Medicine, College of Basic Medical Sciences, China Medical University, Shenyang, Liaoning Province, China.
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Antidiabetic activities of oligosaccharides of Ophiopogonis japonicus in experimental type 2 diabetic rats. Int J Biol Macromol 2012; 51:749-55. [DOI: 10.1016/j.ijbiomac.2012.07.007] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/07/2012] [Revised: 06/07/2012] [Accepted: 07/08/2012] [Indexed: 11/20/2022]
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Farias JM, Maggi RM, Tromm CB, Silva LA, Luciano TF, Marques SO, Lira FS, de Souza CT, Pinho RA. Exercise training performed simultaneously to a high-fat diet reduces the degree of insulin resistance and improves adipoR1-2/APPL1 protein levels in mice. Lipids Health Dis 2012; 11:134. [PMID: 23046739 PMCID: PMC3539884 DOI: 10.1186/1476-511x-11-134] [Citation(s) in RCA: 35] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/11/2012] [Accepted: 09/05/2012] [Indexed: 01/16/2023] Open
Abstract
Background The aim of the present study was to evaluate the protective effect of concurrent exercise in the degree of the insulin resistance in mice fed with a high-fat diet, and assess adiponectin receptors (ADIPOR1 and ADIPOR2) and endosomal adaptor protein APPL1 in different tissues. Methods Twenty-four mice were randomized into four groups (n = 6): chow standard diet and sedentary (C); chow standard diet and simultaneous exercise training (C-T); fed on a high-fat diet and sedentary (DIO); and fed on a high-fat diet and simultaneous exercise training (DIO-T). Simultaneously to starting high-fat diet feeding, the mice were submitted to a swimming exercise training protocol (2 x 30 minutes, with 5 minutes of interval/day), five days per week, for twelve weeks (90 days). Animals were then euthanized 48 hours after the last exercise training session, and adipose, liver, and skeletal muscle tissue were extracted for an immunoblotting analysis. Results IR, IRs, and Akt phosphorylation decreased in the DIO group in the three analyzed tissues. In addition, the DIO group exhibited ADIPOR1 (skeletal muscle and adipose tissue), ADIPOR2 (liver), and APPL1 reduced when compared with the C group. However, it was reverted when exercise training was simultaneously performed. In parallel, ADIPOR1 and 2 and APPL1 protein levels significantly increase in exercised mice. Conclusions Our findings demonstrate that exercise training performed concomitantly to a high-fat diet reduces the degree of insulin resistance and improves adipoR1-2/APPL1 protein levels in the hepatic, adipose, and skeletal muscle tissue.
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Affiliation(s)
- J M Farias
- Laboratory of Exercise Biochemistry and Physiology, Postgraduate Program in Health Sciences, Health Sciences Unit, Universidade do Extremo Sul Catarinense, Criciúma, SC, Brazil
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St-Pierre P, Keith LJ, Richards SM, Rattigan S, Keske MA. Microvascular blood flow responses to muscle contraction are not altered by high-fat feeding in rats. Diabetes Obes Metab 2012; 14:753-61. [PMID: 22429614 DOI: 10.1111/j.1463-1326.2012.01598.x] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
Abstract
AIM Exercise and insulin each increase microvascular blood flow and enhance glucose disposal in skeletal muscle. We have reported that insulin-mediated microvascular recruitment in a diet-induced model of insulin resistance (high-fat feeding for 4 weeks) is markedly impaired; however, the effect of muscle contraction in this model has not been previously explored. METHODS We fed rats either normal (ND, 10% calories from fat) or high-fat (HFD, 60% calories from fat) diets ad libitum for 4-8 weeks. Animals were then anaesthetized and one hindlimb electrically stimulated to contract at 0.05, 0.1 and 2 Hz (field stimulation, 30 V, 0.1 ms duration) in 15 min stepwise increments. Femoral artery blood flow (Transonic flow probe), muscle microvascular blood flow (hindleg metabolism of 1-methylxanthine and contrast-enhanced ultrasound) and muscle glucose disposal (uptake of radiolabelled 2-deoxy-d-glucose and hindleg glucose disappearance) were measured. RESULTS Both ND and HFD rats received the same voltage across the leg and consequently developed the same muscle tension. Femoral artery blood flow in the contracting leg increased during 2 Hz contraction, but not during the lower frequencies and these effects were similar between ND and HFD rats. Muscle microvascular blood flow significantly increased in a contraction frequency-dependent manner, and preceded increases in total limb blood flow and these effects were similar between ND and HFD rats. Muscle glucose disposal was markedly elevated during 2 Hz contraction and was comparable between ND and HFD rats. CONCLUSION Contraction-mediated muscle microvascular recruitment and glucose uptake are not impaired in the HFD insulin resistant rat.
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Affiliation(s)
- P St-Pierre
- Menzies Research Institute Tasmania, University of Tasmania, Hobart, Australia
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Sousa M, Simões HG, Castro CCD, Otaduy MCG, Negrão CE, Pereira RMR, Madsen K, Silva MERD. Carbohydrate supplementation increases intramyocellular lipid stores in elite runners. Metabolism 2012; 61:1189-96. [PMID: 22421463 DOI: 10.1016/j.metabol.2012.01.013] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/15/2011] [Revised: 01/06/2012] [Accepted: 01/17/2012] [Indexed: 10/28/2022]
Abstract
The objective was to determine the effects of carbohydrate (CHO) supplementation on exercise-induced hormone responses and post-training intramyocellular lipid stores (IMCL). Twenty-four elite male athletes (28.0±1.2 years) were randomized to receive CHO (maltodextrin solution) or zero energy placebo solution (control group). The high-intensity running protocol consisted of 10×800 m at 100% of the best 3000-m speed (Vm3 km) and 2×1000 m maximal bouts in the morning and a submaximal 10-km continuous easy running in the afternoon of day 9. IMCL concentrations were assessed by (1)H-MRS before (-day 9) and after training (day 9) in soleus (SO) and tibialis anterior (TA) muscles. Blood hormones were also measured before, during, and post-exercise. The percent change (Δ%) in TA-IMCL was higher in the CHO group (47.9±24.5 IMCL/Cr) than in the control group (-1.7±13.1, respectively) (P=.04). Insulin concentrations were higher in the CHO group post-intermittent running compared to control (P=.02). Circulating levels of free fatty acids and GH were lower in the CHO group (P>.01). The decline in performance in the 2nd 1000-m bout was also attenuated in this group compared to control (P<.001 and P=.0035, respectively). The hormonal milieu (higher insulin and lower GH levels) in the CHO group, together with unchanged free fatty acid levels, probably contributed to the increased IMCL stores. This greater energy storage capacity may have improved post-exercise recovery and thus prevented performance deterioration.
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Affiliation(s)
- Maysa Sousa
- Laboratory of Medical Investigation LIM-18, Faculty of Medicine, University of São Paulo, Av. Dr. Arnaldo 455, São Paulo, SP, Brazil.
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Liu J, Tu H, Zheng H, Zhang L, Tran TP, Muelleman RL, Li YL. Alterations of calcium channels and cell excitability in intracardiac ganglion neurons from type 2 diabetic rats. Am J Physiol Cell Physiol 2011; 302:C1119-27. [PMID: 22189553 DOI: 10.1152/ajpcell.00315.2011] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/15/2023]
Abstract
Clinical study has demonstrated that patients with type 2 diabetes with attenuated arterial baroreflex have higher mortality rate compared with those without arterial baroreflex dysfunction. As a final pathway for the neural control of the cardiac function, functional changes of intracardiac ganglion (ICG) neurons might be involved in the attenuated arterial baroreflex in the type 2 diabetes mellitus (T2DM). Therefore, we measured the ICG neuron excitability and Ca(2+) channels in the sham and T2DM rats. T2DM was induced by a combination of both high-fat diet and low-dose streptozotocin (STZ, 30 mg/kg ip) injection. After 12-14 wk of the above treatment, the T2DM rats presented hyperglycemia, hyperlipidemia, and insulin resistance but no hyperinsulinemia, which closely mimicked the clinical features of the patients with T2DM. Data from immunofluorescence staining showed that L, N, P/Q, and R types of Ca(2+) channels were expressed in the ICG neurons, but only protein expression of N-type Ca(2+) channels was decreased in the ICG neurons from T2DM rats. Using whole cell patch-clamp technique, we found that T2DM significantly reduced the Ca(2+) currents and cell excitability in the ICG neurons. ω-Conotoxin GVIA (a specific N-type Ca(2+) channel blocker, 1 μM) lowered the Ca(2+) currents and cell excitability toward the same level in sham and T2DM rats. These results indicate that the decreased N-type Ca(2+) channels contribute to the suppressed ICG neuron excitability in T2DM rats. From this study, we think high-fat diet/STZ injection-induced T2DM might be an appropriate animal model to test the cellular and molecular mechanisms of cardiovascular autonomic dysfunction.
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Affiliation(s)
- Jinxu Liu
- Department of Emergency Medicine, University of Nebraska Medical Center, Omaha, 68198-5850, USA
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Zhou H, Li YJ, Wang M, Zhang LH, Guo BY, Zhao ZS, Meng FL, Deng YG, Wang RY. Involvement of RhoA/ROCK in myocardial fibrosis in a rat model of type 2 diabetes. Acta Pharmacol Sin 2011; 32:999-1008. [PMID: 21743486 DOI: 10.1038/aps.2011.54] [Citation(s) in RCA: 71] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023] Open
Abstract
AIM To investigate whether activation of RhoA/Rho kinase (ROCK) is involved in myocardial fibrosis in diabetic hearts. METHODS A rat model of type 2 diabetes was established using high fat diet combined with streptozotocin (30 mg/kg, ip). Animals were randomly divided into 3 groups: control rats, untreated diabetic rats that received vehicle and treated diabetic rats that received Rho-kinase inhibitor fasudil hydrochloride hydrate (10 mg·kg(-1)·d(-1), ip, for 14 weeks). Cardiac contractile function was evaluated in vivo. The morphological features of cardiac fibrosis were observed using immunohistochemistry and TEM. The mRNA expression of JNK, TGFβ1, type-I, and type-III procollagen was assessed with RT-PCR. The phosphorylation of MYPT1, JNK and Smad2/3, as well as the protein levels of TGFβ1 and c-Jun, were evaluated using Western blotting. RESULTS In untreated diabetic rats, myocardial fibrosis was developed and the heart contractility was significantly reduced as compared to the control rats. In the hearts of untreated diabetic rats, the mRNA expression level and activity of JNK were upregulated; the expression of TGFβ1 and phosphorylation of Smad2/3 were increased. In the hearts of treated diabetic rat, activation of JNK and TGFβ/Smad was significantly decreased, myocardial fibrosis was reduced, and cardiac contractile function improved. CONCLUSION The data suggest that fasudil hydrochloride hydrate ameliorates myocardial fibrosis in rats with type 2 diabetes at least in part through inhibiting the JNK and TGFβ/Smad pathways. Inhibition of RhoA/ROCK may be a novel therapeutic target for prevention of diabetic cardiomyopathy.
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Sugita S, Kamei Y, Akaike F, Suganami T, Kanai S, Hattori M, Manabe Y, Fujii N, Takai-Igarashi T, Tadaishi M, Oka JI, Aburatani H, Yamada T, Katagiri H, Kakehi S, Tamura Y, Kubo H, Nishida K, Miura S, Ezaki O, Ogawa Y. Increased systemic glucose tolerance with increased muscle glucose uptake in transgenic mice overexpressing RXRγ in skeletal muscle. PLoS One 2011; 6:e20467. [PMID: 21655215 PMCID: PMC3105070 DOI: 10.1371/journal.pone.0020467] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/15/2011] [Accepted: 04/26/2011] [Indexed: 01/27/2023] Open
Abstract
Background Retinoid X receptor (RXR) γ is a nuclear receptor-type transcription
factor expressed mostly in skeletal muscle, and regulated by nutritional
conditions. Previously, we established transgenic mice overexpressing
RXRγ in skeletal muscle (RXRγ mice), which showed lower blood
glucose than the control mice. Here we investigated their glucose
metabolism. Methodology/Principal Findings RXRγ mice were subjected to glucose and insulin tolerance tests, and
glucose transporter expression levels, hyperinsulinemic-euglycemic clamp and
glucose uptake were analyzed. Microarray and bioinformatics analyses were
done. The glucose tolerance test revealed higher glucose disposal in
RXRγ mice than in control mice, but insulin tolerance test revealed no
difference in the insulin-induced hypoglycemic response. In the
hyperinsulinemic-euglycemic clamp study, the basal glucose disposal rate was
higher in RXRγ mice than in control mice, indicating an
insulin-independent increase in glucose uptake. There was no difference in
the rate of glucose infusion needed to maintain euglycemia (glucose infusion
rate) between the RXRγ and control mice, which is consistent with the
result of the insulin tolerance test. Skeletal muscle from RXRγ mice
showed increased Glut1 expression, with increased glucose uptake, in an
insulin-independent manner. Moreover, we performed in vivo
luciferase reporter analysis using Glut1 promoter
(Glut1-Luc). Combination of RXRγ and PPARδ
resulted in an increase in Glut1-Luc activity in skeletal
muscle in vivo. Microarray data showed that RXRγ
overexpression increased a diverse set of genes, including glucose
metabolism genes, whose promoter contained putative PPAR-binding motifs. Conclusions/Significance Systemic glucose metabolism was increased in transgenic mice overexpressing
RXRγ. The enhanced glucose tolerance in RXRγ mice may be mediated at
least in part by increased Glut1 in skeletal muscle. These results show the
importance of skeletal muscle gene regulation in systemic glucose
metabolism. Increasing RXRγ expression may be a novel therapeutic
strategy against type 2 diabetes.
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Affiliation(s)
- Satoshi Sugita
- Department of Molecular Medicine and
Metabolism, Medical Research Institute, Tokyo Medical and Dental University,
Tokyo, Japan
| | - Yasutomi Kamei
- Department of Molecular Medicine and
Metabolism, Medical Research Institute, Tokyo Medical and Dental University,
Tokyo, Japan
- * E-mail:
| | - Fumiko Akaike
- Department of Molecular Medicine and
Metabolism, Medical Research Institute, Tokyo Medical and Dental University,
Tokyo, Japan
- Laboratory of Pharmacology, Faculty of
Pharmaceutical Sciences, Tokyo University of Science, Chiba, Japan
| | - Takayoshi Suganami
- Department of Molecular Medicine and
Metabolism, Medical Research Institute, Tokyo Medical and Dental University,
Tokyo, Japan
| | - Sayaka Kanai
- Department of Molecular Medicine and
Metabolism, Medical Research Institute, Tokyo Medical and Dental University,
Tokyo, Japan
| | - Maki Hattori
- Department of Molecular Medicine and
Metabolism, Medical Research Institute, Tokyo Medical and Dental University,
Tokyo, Japan
- Laboratory of Pharmacology, Faculty of
Pharmaceutical Sciences, Tokyo University of Science, Chiba, Japan
| | - Yasuko Manabe
- Graduate School of Human Health Sciences,
Tokyo Metropolitan University, Tokyo, Japan
| | - Nobuharu Fujii
- Graduate School of Human Health Sciences,
Tokyo Metropolitan University, Tokyo, Japan
| | - Takako Takai-Igarashi
- Department of Bioinformatics, Graduate School
of Biomedical Science, Tokyo Medical and Dental University, Tokyo,
Japan
| | - Miki Tadaishi
- Nutritional Science Program, National
Institute of Health and Nutrition, Tokyo, Japan
- Department of Nutritional Science, Faculty of
Applied Bioscience, Tokyo University of Agriculture, Tokyo, Japan
| | - Jun-Ichiro Oka
- Laboratory of Pharmacology, Faculty of
Pharmaceutical Sciences, Tokyo University of Science, Chiba, Japan
| | - Hiroyuki Aburatani
- Research Center for Advanced Science and
Technology, University of Tokyo, Tokyo, Japan
| | - Tetsuya Yamada
- Department of Metabolic Diseases, Center for
Metabolic Diseases, Tohoku University Graduate School of Medicine, Miyagi,
Japan
| | - Hideki Katagiri
- Department of Metabolic Diseases, Center for
Metabolic Diseases, Tohoku University Graduate School of Medicine, Miyagi,
Japan
| | - Saori Kakehi
- Department of Medicine, Metabolism and
Endocrinology, School of Medicine, Juntendo University, Tokyo, Japan
| | - Yoshifumi Tamura
- Department of Medicine, Metabolism and
Endocrinology, School of Medicine, Juntendo University, Tokyo, Japan
- Sportology Center, Juntendo University,
Tokyo, Japan
| | | | | | - Shinji Miura
- Nutritional Science Program, National
Institute of Health and Nutrition, Tokyo, Japan
| | - Osamu Ezaki
- Nutritional Science Program, National
Institute of Health and Nutrition, Tokyo, Japan
| | - Yoshihiro Ogawa
- Department of Molecular Medicine and
Metabolism, Medical Research Institute, Tokyo Medical and Dental University,
Tokyo, Japan
- Global Center of Excellence Program,
International Research Center for Molecular Science in Tooth and Bone Diseases,
Medical Research Institute, Tokyo Medical and Dental University, Tokyo,
Japan
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