1
|
Wu T, Li Z, Wei Y. Advances in understanding mechanisms underlying mitochondrial structure and function damage by ozone. THE SCIENCE OF THE TOTAL ENVIRONMENT 2023; 861:160589. [PMID: 36462650 DOI: 10.1016/j.scitotenv.2022.160589] [Citation(s) in RCA: 8] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/14/2022] [Revised: 11/25/2022] [Accepted: 11/26/2022] [Indexed: 06/17/2023]
Abstract
Mitochondria are double-membraned organelles found in eukaryotic cells. The integrity of mitochondrial structure and function determines cell destiny. Mitochondria are also the "energy factories of cells." The production of energy is accompanied by reactive oxygen species (ROS) generation. Generally, the production and consumption of ROS maintains a balance in cells. Ozone is a highly oxidizing, harmful substance in ground-level atmosphere. Ozone inhalation causes oxidative injury owing to the generation of ROS, resulting in mitochondrial oxidative stress overload. Oxidative damage to the mitochondria induces a vicious cycle of ROS production which might destroy mitochondrial DNA and mitochondrial structure and function in cells. ROS can alter the phosphorylation of various signaling molecules, triggering a series of downstream signaling pathway reactions. These include inflammatory responses, pyroptosis, autophagy, and apoptosis. Changes involving these molecular mechanisms may be related to the occurrence of disease. According to numerous epidemiological investigations, ozone exposure induces respiratory, cardiovascular, and nervous system diseases in humans. In addition, these systems require large quantities of energy. Hence, the mitochondrial damage caused by ozone may act as a bridge between human diseases. However, the specific molecular mechanisms involved require further investigation. This review discusses our understanding of the structure and function of mitochondria the mechanisms underlying ozone-induced mitochondrial damage.
Collapse
Affiliation(s)
- Tingting Wu
- State Key Laboratory of Environmental Criteria and Risk Assessment, Chinese Research Academy of Environmental Sciences, Beijing, China
| | - Zhigang Li
- State Key Laboratory of Environmental Criteria and Risk Assessment, Chinese Research Academy of Environmental Sciences, Beijing, China
| | - Yongjie Wei
- State Key Laboratory of Environmental Criteria and Risk Assessment, Chinese Research Academy of Environmental Sciences, Beijing, China; Center for Global Health, School of Public Health, Nanjing Medical University, China.
| |
Collapse
|
2
|
Lee JH, Zhang D, Kwak SE, Shin HE, Song W. Effects of Exercise and a High-Fat, High-Sucrose Restriction Diet on Metabolic Indicators, Nr4a3, and Mitochondria-Associated Protein Expression in the Gastrocnemius Muscles of Mice with Diet-Induced Obesity. J Obes Metab Syndr 2021; 30:44-54. [PMID: 33518534 PMCID: PMC8017331 DOI: 10.7570/jomes20043] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/11/2020] [Revised: 06/08/2020] [Accepted: 11/17/2020] [Indexed: 12/17/2022] Open
Abstract
Background Exercise and high fat, high sucrose restriction diets are well known treatments for obesity. The aim of this study was to measure the effects of those lifestyle interventions on molecular transducers of exercise, such as Nr4a3, mitochondria-associated proteins, and muscle function. Methods We conducted 8 weeks of treadmill exercise and sucrose or fat restriction diets in obese mice. The mice were divided into eight groups: the normal diet (CON) group, normal diet with exercise (CONEX) group, high fat, high sucrose diet (HFHS) group, HFHS with exercise (HFHSEX) group, sucrose restriction (SR) group, SR with exercise (SREX) group, high fat, high sucrose restriction (ND) group, and ND with exercise (NDEX) group. Results The 8 weeks of exercise reduced body weight, improved lipid profiles (total cholesterol, triglycerides), and increased hanging time. The combination of exercise and a fat and sucrose restriction diet improved glucose tolerance and increased grip strength. The 8 weeks of intervention did not significantly affect the Nr4a3 protein level. The sucrose and fat restriction diet increased the phosphorylated protein kinase B (pAkt)/Akt ratio, and its level was lower in the HFHS group. Exercise increased the protein expression level of PGC-1α in obese conditions. Moreover, SR led reduced the phosphorylated AMP-activated protein kinase (pAMPK)/AMPK ratio and PGC-1α to the control level. Conclusion The 8 weeks of exercise or a sucrose and fat restriction diet improved metabolic indicators and muscle function. SR reduced pAMPK/AMPK and PGC-1α to the control level. Nr4a3 protein expression was not significantly changed by either exercise or a fat and sucrose restriction diet.
Collapse
Affiliation(s)
- Ji-Heun Lee
- Institute of Sports Science, Department of Physical Education, Seoul National University, Seoul, Korea
| | - Didi Zhang
- Institute of Sports Science, Department of Physical Education, Seoul National University, Seoul, Korea
| | - Seong-Eun Kwak
- Institute of Sports Science, Department of Physical Education, Seoul National University, Seoul, Korea
| | - Hyung-Eun Shin
- Institute of Sports Science, Department of Physical Education, Seoul National University, Seoul, Korea
| | - Wook Song
- Institute of Sports Science, Department of Physical Education, Seoul National University, Seoul, Korea.,Institute on Aging, Seoul National University, Seoul, Korea
| |
Collapse
|
3
|
Low-Intensity Exercise Training Additionally Increases Mitochondrial Dynamics Caused by High-Fat Diet (HFD) but Has No Additional Effect on Mitochondrial Biogenesis in Fast-Twitch Muscle by HFD. INTERNATIONAL JOURNAL OF ENVIRONMENTAL RESEARCH AND PUBLIC HEALTH 2020; 17:ijerph17155461. [PMID: 32751208 PMCID: PMC7432492 DOI: 10.3390/ijerph17155461] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 06/16/2020] [Revised: 07/27/2020] [Accepted: 07/28/2020] [Indexed: 01/07/2023]
Abstract
This study examines how the high-fat diet (HFD) affects mitochondrial dynamics and biogenesis, and also whether combining it with low-intensity endurance exercise adds to these effects. Six 8-week-old male Sprague–Dawley (SD) rats were put on control (CON; standard chow diet), HF (HFD intake), and HFEx (HFD + low-intensity treadmill exercise) for 6 weeks. As a result, no change in body weight was observed among the groups. However, epididymal fat mass increased significantly in the two groups that had been given HFD. Blood free fatty acid (FFA) also increased significantly in the HF group. While HFD increased insulin resistance (IR), this was improved significantly in the HFEx group. HFD also significantly increased mitochondrial biogenesis-related factors (PPARδ, PGC-1α, and mtTFA) and mitochondrial electron transport chain proteins; however, no additional effect from exercise was observed. Mitochondrial dynamic-related factors were also affected: Mfn2 increased significantly in the HFEx group, while Drp1 and Fis-1 increased significantly in both the HF and HFEx groups. The number of mitochondria in the subsarcolemmal region, and their size in the subsarcolemmal and intermyofibrillar regions, also increased significantly in the HFEx group. Taken overall, these results show that HFD in combination with low-intensity endurance exercise has no additive effect on mitochondrial biogenesis, although it does have such an effect on mitochondrial dynamics by improving IR.
Collapse
|
4
|
Chen T, Hill JT, Moore TM, Cheung ECK, Olsen ZE, Piorczynski TB, Marriott TD, Tessem JS, Walton CM, Bikman BT, Hansen JM, Thomson DM. Lack of skeletal muscle liver kinase B1 alters gene expression, mitochondrial content, inflammation and oxidative stress without affecting high-fat diet-induced obesity or insulin resistance. Biochim Biophys Acta Mol Basis Dis 2020; 1866:165805. [PMID: 32339642 DOI: 10.1016/j.bbadis.2020.165805] [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] [Received: 01/21/2020] [Revised: 04/02/2020] [Accepted: 04/16/2020] [Indexed: 12/28/2022]
Abstract
Ad libitum high-fat diet (HFD) induces obesity and skeletal muscle metabolic dysfunction. Liver kinase B1 (LKB1) regulates skeletal muscle metabolism by controlling the AMP-activated protein kinase family, but its importance in regulating muscle gene expression and glucose tolerance in obese mice has not been established. The purpose of this study was to determine how the lack of LKB1 in skeletal muscle (KO) affects gene expression and glucose tolerance in HFD-fed, obese mice. KO and littermate control wild-type (WT) mice were fed a standard diet or HFD for 14 weeks. RNA sequencing, and subsequent analysis were performed to assess mitochondrial content and respiration, inflammatory status, glucose and insulin tolerance, and muscle anabolic signaling. KO did not affect body weight gain on HFD, but heavily impacted mitochondria-, oxidative stress-, and inflammation-related gene expression. Accordingly, mitochondrial protein content and respiration were suppressed while inflammatory signaling and markers of oxidative stress were elevated in obese KO muscles. KO did not affect glucose or insulin tolerance. However, fasting serum insulin and skeletal muscle insulin signaling were higher in the KO mice. Furthermore, decreased muscle fiber size in skmLKB1-KO mice was associated with increased general protein ubiquitination and increased expression of several ubiquitin ligases, but not muscle ring finger 1 or atrogin-1. Taken together, these data suggest that the lack of LKB1 in skeletal muscle does not exacerbate obesity or insulin resistance in mice on a HFD, despite impaired mitochondrial content and function and elevated inflammatory signaling and oxidative stress.
Collapse
Affiliation(s)
- Ting Chen
- Department of Physiology and Developmental Biology, Brigham Young University, Provo, UT 84602, USA
| | - Jonathon T Hill
- Department of Physiology and Developmental Biology, Brigham Young University, Provo, UT 84602, USA
| | - Timothy M Moore
- David Geffen School of Medicine, Department of Medicine, University of California, Los Angeles, CA 90095, USA
| | - Eric C K Cheung
- Department of Physiology and Developmental Biology, Brigham Young University, Provo, UT 84602, USA
| | - Zachary E Olsen
- Department of Physiology and Developmental Biology, Brigham Young University, Provo, UT 84602, USA
| | - Ted B Piorczynski
- Department of Physiology and Developmental Biology, Brigham Young University, Provo, UT 84602, USA
| | - Tanner D Marriott
- Department of Physiology and Developmental Biology, Brigham Young University, Provo, UT 84602, USA
| | - Jeffery S Tessem
- Department of Nutrition, Dietetics and Food Science, Brigham Young University, Provo, UT 84602, USA
| | - Chase M Walton
- Department of Physiology and Developmental Biology, Brigham Young University, Provo, UT 84602, USA
| | - Benjamin T Bikman
- Department of Physiology and Developmental Biology, Brigham Young University, Provo, UT 84602, USA
| | - Jason M Hansen
- Department of Physiology and Developmental Biology, Brigham Young University, Provo, UT 84602, USA
| | - David M Thomson
- Department of Physiology and Developmental Biology, Brigham Young University, Provo, UT 84602, USA; Department of Nutrition, Dietetics and Food Science, Brigham Young University, Provo, UT 84602, USA.
| |
Collapse
|
5
|
Kwon J, Kim B, Lee C, Joung H, Kim BK, Choi IS, Hyun CK. Comprehensive amelioration of high-fat diet-induced metabolic dysfunctions through activation of the PGC-1α pathway by probiotics treatment in mice. PLoS One 2020; 15:e0228932. [PMID: 32040532 PMCID: PMC7010303 DOI: 10.1371/journal.pone.0228932] [Citation(s) in RCA: 17] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/05/2019] [Accepted: 01/27/2020] [Indexed: 02/07/2023] Open
Abstract
Although the beneficial effects of probiotics in the prevention or treatment of metabolic disorders have been extensively researched, the precise mechanisms by which probiotics improve metabolic homeostasis are still not clear. Given that probiotics usually exert a comprehensive effect on multiple metabolic disorders, defining a concurrent mechanism underlying the multiple effects is critical to understand the function of probiotics. In this study, we identified the SIRT1-dependent or independent PGC-1α pathways in multiple organs that mediate the protective effects of a strain of Lactobacillus plantarum against high-fat diet-induced adiposity, glucose intolerance, and dyslipidemia. L. plantarum treatment significantly enhanced the expression of SIRT1, PPARα, and PGC-1α in the liver and adipose tissues under HFD-fed condition. L. plantarum treated mice also exhibited significantly increased expressions of genes involved in bile acid synthesis and reverse cholesterol transport in the liver, browning and thermogenesis of adipose tissue, and fatty acid oxidation in the liver and adipose tissue. Additionally, L. plantarum treatment significantly upregulated the expressions of adiponectin in adipose tissue, irisin in skeletal muscle and subcutaneous adipose tissue (SAT), and FGF21 in SAT. These beneficial changes were associated with a significantly improved HFD-induced alteration of gut microbiota. Our findings suggest that the PGC-1α-mediated pathway could be regarded as a potential target in the development of probiotics-based therapies for the prevention and treatment of metabolic disorders.
Collapse
Affiliation(s)
- Jeonghyeon Kwon
- School of Life Science, Handong Global University, Pohang, Gyungbuk, South Korea
| | - Bobae Kim
- School of Life Science, Handong Global University, Pohang, Gyungbuk, South Korea
| | - Chungho Lee
- School of Life Science, Handong Global University, Pohang, Gyungbuk, South Korea
| | - Hyunchae Joung
- Chong Kun Dang Bio Research Institute, Ansan, Gyeonggi, South Korea
| | - Byoung-Kook Kim
- Chong Kun Dang Bio Research Institute, Ansan, Gyeonggi, South Korea
| | - In Suk Choi
- Chong Kun Dang Bio Research Institute, Ansan, Gyeonggi, South Korea
| | - Chang-Kee Hyun
- School of Life Science, Handong Global University, Pohang, Gyungbuk, South Korea
- * E-mail:
| |
Collapse
|
6
|
Koh JH, Hancock CR, Han DH, Holloszy JO, Nair KS, Dasari S. AMPK and PPARβ positive feedback loop regulates endurance exercise training-mediated GLUT4 expression in skeletal muscle. Am J Physiol Endocrinol Metab 2019; 316:E931-E939. [PMID: 30888859 PMCID: PMC6580175 DOI: 10.1152/ajpendo.00460.2018] [Citation(s) in RCA: 26] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
Abstract
The objective of this study is to determine whether AMP-activated protein kinase (AMPK), peroxisome proliferator-activated receptor gamma coactivator 1-α (PGC-1α), or peroxisome proliferator-activated receptor β (PPARβ) can independently mediate the increase of glucose transporter type 4 (GLUT4) expression that occurs in response to exercise training. We found that PPARβ can regulate GLUT4 expression without PGC-1α. We also found AMPK and PPARβ are important for maintaining normal physiological levels of GLUT4 protein in the sedentary condition as well following exercise training. However, AMPK and PPARβ are not essential for the increase in GLUT4 protein expression that occurs in response to exercise training. We discovered that AMPK activation increases PPARβ via myocyte enhancer factor 2A (MEF2A), which acted as a transcription factor for PPARβ. Furthermore, exercise training increases the cooperation of AMPK and PPARβ to regulate glucose uptake. In conclusion, cooperation between AMPK and PPARβ via NRF-1/MEF2A pathway enhances the exercise training mediated adaptive increase in GLUT4 expression and subsequent glucose uptake in skeletal muscle.
Collapse
Affiliation(s)
- Jin-Ho Koh
- Department of Internal Medicine, Mayo Clinic , Rochester, Minnesota
- Department of Physiology, College of Medicine, Yeungnam University , Daegu , Korea
| | - Chad R Hancock
- Department of Nutrition, Dietetics and Food Science, Brigham Young University , Provo, Utah
| | - Dong-Ho Han
- Division of Geriatrics and Nutritional Sciences, Department of Medicine, Washington University School of Medicine , St. Louis, Missouri
| | - John O Holloszy
- Division of Geriatrics and Nutritional Sciences, Department of Medicine, Washington University School of Medicine , St. Louis, Missouri
| | | | - Surendra Dasari
- Department of Health Sciences Research, Mayo Clinic , Rochester, Minnesota
| |
Collapse
|
7
|
Tanaka M, Sugimoto K, Fujimoto T, Xie K, Takahashi T, Akasaka H, Kurinami H, Yasunobe Y, Matsumoto T, Fujino H, Rakugi H. Preventive effects of low-intensity exercise on cancer cachexia-induced muscle atrophy. FASEB J 2019; 33:7852-7862. [PMID: 30916585 DOI: 10.1096/fj.201802430r] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
We hypothesized that low-intensity endurance exercise might be more effective in preventing cancer cachexia-induced muscle atrophy through both an increase in protein synthesis and a decrease in protein degradation. The purpose of present study was to evaluate the effects and to clarify the mechanism of low-intensity endurance exercise on cancer cachexia-induced muscle atrophy. Twenty-four male Wistar rats were randomly divided into 4 groups: control (Cont), Cont plus exercise (Ex), AH130-induced cancer cachexia (AH130), and AH130 plus Ex. Cancer cachexia was induced by intraperitoneal injections with AH130 Yoshida ascites hepatoma cells; we analyzed the changes in muscle mass and the gene and protein expression levels of major regulators or indicators of skeletal muscle protein degradation and synthesis pathway in the soleus muscles. Low-intensity exercise inhibited the muscle mass loss through a suppression of the ubiquitin-proteasome pathway, increased hypoxia-inducible factor- 1α and phosphorylated AMPK, and inhibited the deactivation of mammalian target of rapamycin pathway in the soleus muscle, which contributed to the prevention of cancer cachexia-induced muscle atrophy. These results suggest that low-intensity exercise has the potential to become an effective therapeutic intervention for the prevention of cancer cachexia-induced muscle atrophy.-Tanaka, M., Sugimoto, K., Fujimoto, T., Xie, K., Takahashi, T., Akasaka, H., Kurinami, H., Yasunobe, Y., Matsumoto, T., Fujino, H., Rakugi, H. Preventive effects of low-intensity exercise on cancer cachexia-induced muscle atrophy.
Collapse
Affiliation(s)
- Minoru Tanaka
- Department of Geriatric and General Medicine, Osaka University Graduate School of Medicine, Suita, Japan.,Department of Rehabilitation Science, Kobe University Graduate School of Health Sciences, Kobe, Japan.,Department of Rehabilitation Science, Osaka Health Science University, Osaka, Japan
| | - Ken Sugimoto
- Department of Geriatric and General Medicine, Osaka University Graduate School of Medicine, Suita, Japan.,Department of Rehabilitation Science, Osaka Health Science University, Osaka, Japan
| | - Taku Fujimoto
- Department of Geriatric and General Medicine, Osaka University Graduate School of Medicine, Suita, Japan
| | - Keyu Xie
- Department of Geriatric and General Medicine, Osaka University Graduate School of Medicine, Suita, Japan
| | - Toshimasa Takahashi
- Department of Geriatric and General Medicine, Osaka University Graduate School of Medicine, Suita, Japan
| | - Hiroshi Akasaka
- Department of Geriatric and General Medicine, Osaka University Graduate School of Medicine, Suita, Japan
| | - Hitomi Kurinami
- Department of Geriatric and General Medicine, Osaka University Graduate School of Medicine, Suita, Japan
| | - Yukiko Yasunobe
- Department of Geriatric and General Medicine, Osaka University Graduate School of Medicine, Suita, Japan
| | - Tomohiro Matsumoto
- Department of Rehabilitation Science, Kobe University Graduate School of Health Sciences, Kobe, Japan
| | - Hidemi Fujino
- Department of Rehabilitation Science, Kobe University Graduate School of Health Sciences, Kobe, Japan
| | - Hiromi Rakugi
- Department of Geriatric and General Medicine, Osaka University Graduate School of Medicine, Suita, Japan
| |
Collapse
|
8
|
Bakshi I, Brown SHJ, Brandon AE, Suryana E, Mitchell TW, Turner N, Cooney GJ. Increasing Acyl CoA thioesterase activity alters phospholipid profile without effect on insulin action in skeletal muscle of rats. Sci Rep 2018; 8:13967. [PMID: 30228369 PMCID: PMC6143561 DOI: 10.1038/s41598-018-32354-w] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/18/2017] [Accepted: 05/18/2018] [Indexed: 12/25/2022] Open
Abstract
Increased lipid metabolism in muscle is associated with insulin resistance and therefore, many strategies have been employed to alter fatty acid metabolism and study the impact on insulin action. Metabolism of fatty acid requires activation to fatty acyl CoA by Acyl CoA synthases (ACSL) and fatty acyl CoA can be hydrolysed by Acyl CoA thioesterases (Acot). Thioesterase activity is low in muscle, so we overexpressed Acot7 in muscle of chow and high-fat diet (HFD) rats and investigated effects on insulin action. Acot7 overexpression modified specific phosphatidylcholine and phosphatidylethanolamine species in tibialis muscle of chow rats to levels similar to those observed in control HFD muscle. The changes in phospholipid species did not alter glucose uptake in tibialis muscle under hyperinsulinaemic/euglycaemic clamped conditions. Acot7 overexpression in white extensor digitorum longus (EDL) muscle increased complete fatty acid oxidation ex-vivo but was not associated with any changes in glucose uptake in-vivo, however overexpression of Acot7 in red EDL reduced insulin-stimulated glucose uptake in-vivo which correlated with increased incomplete fatty acid oxidation ex-vivo. In summary, although overexpression of Acot7 in muscle altered some aspects of lipid profile and metabolism in muscle, this had no major effect on insulin-stimulated glucose uptake.
Collapse
Affiliation(s)
- Ishita Bakshi
- Diabetes and Metabolism Division, Garvan Institute, Sydney, Australia
| | - Simon H J Brown
- School of Biological Sciences, University of Wollongong, Wollongong, Australia
| | - Amanda E Brandon
- Diabetes and Metabolism Division, Garvan Institute, Sydney, Australia.,Sydney Medical School, Charles Perkins Centre, The University of Sydney, Sydney, Australia
| | - Eurwin Suryana
- Diabetes and Metabolism Division, Garvan Institute, Sydney, Australia
| | - Todd W Mitchell
- School of Biological Sciences, University of Wollongong, Wollongong, Australia
| | - Nigel Turner
- Department of Pharmacology, School of Medical Sciences, UNSW Sydney, Sydney, Australia
| | - Gregory J Cooney
- Diabetes and Metabolism Division, Garvan Institute, Sydney, Australia. .,Sydney Medical School, Charles Perkins Centre, The University of Sydney, Sydney, Australia.
| |
Collapse
|
9
|
Sending the Signal: Muscle Glycogen Availability as a Regulator of Training Adaptation. ACTA ACUST UNITED AC 2018. [DOI: 10.1007/978-3-319-72790-5_4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register]
|
10
|
Baldassini WA, Ramsey JJ, Hagopian K, Lanna DPD. The influence of Shc proteins and high-fat diet on energy metabolism of mice. Cell Biochem Funct 2018; 35:527-537. [PMID: 29243276 DOI: 10.1002/cbf.3310] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/27/2017] [Revised: 09/22/2017] [Accepted: 11/08/2017] [Indexed: 01/24/2023]
Abstract
The purpose of this study was to determine if Shc proteins influence the metabolic response to acute (7 days) feeding of a high-fat diet (HFD). To this end, whole animal energy expenditure (EE) and substrate oxidation were measured in the Shc knockout (ShcKO) and wild-type (WT) mice fed a control or HFD. The activities of enzymes of glycolysis, the citric acid cycle, electron transport chain (ETC), and β-oxidation were also investigated in liver and skeletal muscle of ShcKO and WT animals. The study showed that ShcKO increases (P < .05) EE adjusted for either total body weight or lean mass. This change in EE could contribute to decreases in weight gain in ShcKO versus WT mice fed an HFD. Thus, our results indicate that Shc proteins should be considered as potential targets for developing interventions to mitigate weight gain on HFD by stimulating EE. Although decreased levels of Shc proteins influenced the activity of some enzymes in response to high-fat feeding (eg, increasing the activity of acyl-CoA dehydrogenase), it did not produce concerted changes in enzymes of glycolysis, citric acid cycle, or the ETC. The physiological significance of observed changes in select enzyme activities remains to be determined. SIGNIFICANCE OF THE STUDY We report higher EE in ShcKO versus WT mice when consuming the HFD. Although decreased levels of Shc proteins influenced the activity of a central enzyme of β-oxidation in response to high-fat feeding, it did not produce concerted changes in enzymes of glycolysis, citric acid cycle, or the ETC. Thus, an increase in EE in response to consumption of an HFD may be a mechanism that leads to decreased weight gain previously reported in ShcKO mice with long-term consumption of an HFD.
Collapse
Affiliation(s)
- W A Baldassini
- Department of Animal Science, "Luiz de Queiroz" College of Agriculture (ESALQ), University of São Paulo (USP), Piracicaba, São Paulo, Brazil
| | - J J Ramsey
- Veterinary Medicine, Molecular Biosciences, University of California-Davis (UC DAVIS), Davis, CA, USA
| | - K Hagopian
- Veterinary Medicine, Molecular Biosciences, University of California-Davis (UC DAVIS), Davis, CA, USA
| | - D P D Lanna
- Department of Animal Science, "Luiz de Queiroz" College of Agriculture (ESALQ), University of São Paulo (USP), Piracicaba, São Paulo, Brazil
| |
Collapse
|
11
|
Alternate-Day High-Fat Diet Induces an Increase in Mitochondrial Enzyme Activities and Protein Content in Rat Skeletal Muscle. Nutrients 2016; 8:203. [PMID: 27058555 PMCID: PMC4848672 DOI: 10.3390/nu8040203] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/13/2016] [Revised: 03/25/2016] [Accepted: 03/30/2016] [Indexed: 11/20/2022] Open
Abstract
Long-term high-fat diet increases muscle mitochondrial enzyme activity and endurance performance. However, excessive calorie intake causes intra-abdominal fat accumulation and metabolic syndrome. The purpose of this study was to investigate the effect of an alternating day high-fat diet on muscle mitochondrial enzyme activities, protein content, and intra-abdominal fat mass in rats. Male Wistar rats were given a standard chow diet (CON), high-fat diet (HFD), or alternate-day high-fat diet (ALT) for 4 weeks. Rats in the ALT group were fed a high-fat diet and standard chow every other day for 4 weeks. After the dietary intervention, mitochondrial enzyme activities and protein content in skeletal muscle were measured. Although body weight did not differ among groups, the epididymal fat mass in the HFD group was higher than those of the CON and ALT groups. Citrate synthase and beta-hydroxyacyl CoA dehydrogenase activities in the plantaris muscle of rats in HFD and ALT were significantly higher than that in CON rats, whereas there was no difference between HFD and ALT groups. No significant difference was observed in muscle glycogen concentration or glucose transporter-4 protein content among the three groups. These results suggest that an alternate-day high-fat diet induces increases in mitochondrial enzyme activities and protein content in rat skeletal muscle without intra-abdominal fat accumulation.
Collapse
|
12
|
Makimura H, Stanley TL, Suresh C, De Sousa-Coelho AL, Frontera WR, Syu S, Braun LR, Looby SE, Feldpausch MN, Torriani M, Lee H, Patti ME, Grinspoon SK. Metabolic Effects of Long-Term Reduction in Free Fatty Acids With Acipimox in Obesity: A Randomized Trial. J Clin Endocrinol Metab 2016; 101:1123-33. [PMID: 26691888 PMCID: PMC4803166 DOI: 10.1210/jc.2015-3696] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/29/2023]
Abstract
CONTEXT Increased circulating free fatty acids (FFAs) have been proposed to contribute to insulin resistance in obesity. Short-term studies have investigated the effects of acipimox, an inhibitor of hormone-sensitive lipase, on glucose homeostasis, but longer-term studies have not been performed. OBJECTIVE To test the hypothesis that long-term treatment with acipimox would reduce FFA and improve insulin sensitivity among nondiabetic, insulin-resistant, obese subjects. DESIGN, SETTING, PATIENTS, AND INTERVENTION At an academic medical center, 39 obese men and women were randomized to acipimox 250 mg thrice-daily vs identical placebo for 6 months. MAIN OUTCOME MEASURES Plasma lipids, insulin sensitivity, adiponectin, and mitochondrial function via assessment of the rate of post-exercise phosphocreatine recovery on (31)P-magnetic resonance spectroscopy as well as muscle mitochondrial density and relevant muscle gene expression. RESULTS Fasting glucose decreased significantly in acipimox-treated individuals (effect size, -6 mg/dL; P = .02), in parallel with trends for reduced fasting insulin (effect size, -6.8 μU/mL; P = .07) and HOMA-IR (effect size, -1.96; P = .06), and significantly increased adiponectin (effect size, +668 ng/mL; P = .02). Acipimox did not affect insulin-stimulated glucose uptake, as assessed by euglycemic, hyperinsulinemic clamp. Effects on muscle mitochondrial function and density and on relevant gene expression were not seen. CONCLUSION These data shed light on the long-term effects of FFA reduction on insulin sensitivity, other metabolic parameters, and muscle mitochondrial function in obesity. Reduced FFA achieved by acipimox improved fasting measures of glucose homeostasis, lipids, and adiponectin but had no effect on mitochondrial function, mitochondrial density, or muscle insulin sensitivity.
Collapse
Affiliation(s)
- Hideo Makimura
- Program in Nutritional Metabolism and Neuroendocrine Unit (H.M., T.L.S., C.S., S.S., L.R.B., S.E.L., M.N.F., S.K.G.), Massachusetts General Hospital, Boston, Massachusetts 02114; Harvard Medical School (H.M., T.L.S., A.L.D.S.-C., L.R.B., S.E.L., M.T., H.L., M.-E.P., S.K.G.), Boston, Massachusetts 02115; Pediatric Endocrine Unit (T.L.S., L.R.B.), Massachusetts General Hospital, Boston, Massachusetts 02114; Research Division (A.L.D.S.-C., M.-E.P.), Joslin Diabetes Center, Boston, Massachusetts 02215; Department of Physical Medicine and Rehabilitation (W.R.F.), Vanderbilt University Medical Center, Nashville, Tennessee 37212; Department of Physical Medicine and Rehabilitation (W.R.F.), Harvard Medical School/Spaulding Rehabilitation Hospital, Boston, Massachusetts 02114; Department of Physiology (W.R.F.), University of Puerto Rico School of Medicine, San Juan, Puerto Rico 00936; Department of Radiology (M.T.), Massachusetts General Hospital, Boston, Massachusetts 02114; and MGH Biostatistics Center (H.L.), Massachusetts General Hospital and Harvard Medical Center, Boston, Massachusetts 02114
| | - Takara L Stanley
- Program in Nutritional Metabolism and Neuroendocrine Unit (H.M., T.L.S., C.S., S.S., L.R.B., S.E.L., M.N.F., S.K.G.), Massachusetts General Hospital, Boston, Massachusetts 02114; Harvard Medical School (H.M., T.L.S., A.L.D.S.-C., L.R.B., S.E.L., M.T., H.L., M.-E.P., S.K.G.), Boston, Massachusetts 02115; Pediatric Endocrine Unit (T.L.S., L.R.B.), Massachusetts General Hospital, Boston, Massachusetts 02114; Research Division (A.L.D.S.-C., M.-E.P.), Joslin Diabetes Center, Boston, Massachusetts 02215; Department of Physical Medicine and Rehabilitation (W.R.F.), Vanderbilt University Medical Center, Nashville, Tennessee 37212; Department of Physical Medicine and Rehabilitation (W.R.F.), Harvard Medical School/Spaulding Rehabilitation Hospital, Boston, Massachusetts 02114; Department of Physiology (W.R.F.), University of Puerto Rico School of Medicine, San Juan, Puerto Rico 00936; Department of Radiology (M.T.), Massachusetts General Hospital, Boston, Massachusetts 02114; and MGH Biostatistics Center (H.L.), Massachusetts General Hospital and Harvard Medical Center, Boston, Massachusetts 02114
| | - Caroline Suresh
- Program in Nutritional Metabolism and Neuroendocrine Unit (H.M., T.L.S., C.S., S.S., L.R.B., S.E.L., M.N.F., S.K.G.), Massachusetts General Hospital, Boston, Massachusetts 02114; Harvard Medical School (H.M., T.L.S., A.L.D.S.-C., L.R.B., S.E.L., M.T., H.L., M.-E.P., S.K.G.), Boston, Massachusetts 02115; Pediatric Endocrine Unit (T.L.S., L.R.B.), Massachusetts General Hospital, Boston, Massachusetts 02114; Research Division (A.L.D.S.-C., M.-E.P.), Joslin Diabetes Center, Boston, Massachusetts 02215; Department of Physical Medicine and Rehabilitation (W.R.F.), Vanderbilt University Medical Center, Nashville, Tennessee 37212; Department of Physical Medicine and Rehabilitation (W.R.F.), Harvard Medical School/Spaulding Rehabilitation Hospital, Boston, Massachusetts 02114; Department of Physiology (W.R.F.), University of Puerto Rico School of Medicine, San Juan, Puerto Rico 00936; Department of Radiology (M.T.), Massachusetts General Hospital, Boston, Massachusetts 02114; and MGH Biostatistics Center (H.L.), Massachusetts General Hospital and Harvard Medical Center, Boston, Massachusetts 02114
| | - Ana Luisa De Sousa-Coelho
- Program in Nutritional Metabolism and Neuroendocrine Unit (H.M., T.L.S., C.S., S.S., L.R.B., S.E.L., M.N.F., S.K.G.), Massachusetts General Hospital, Boston, Massachusetts 02114; Harvard Medical School (H.M., T.L.S., A.L.D.S.-C., L.R.B., S.E.L., M.T., H.L., M.-E.P., S.K.G.), Boston, Massachusetts 02115; Pediatric Endocrine Unit (T.L.S., L.R.B.), Massachusetts General Hospital, Boston, Massachusetts 02114; Research Division (A.L.D.S.-C., M.-E.P.), Joslin Diabetes Center, Boston, Massachusetts 02215; Department of Physical Medicine and Rehabilitation (W.R.F.), Vanderbilt University Medical Center, Nashville, Tennessee 37212; Department of Physical Medicine and Rehabilitation (W.R.F.), Harvard Medical School/Spaulding Rehabilitation Hospital, Boston, Massachusetts 02114; Department of Physiology (W.R.F.), University of Puerto Rico School of Medicine, San Juan, Puerto Rico 00936; Department of Radiology (M.T.), Massachusetts General Hospital, Boston, Massachusetts 02114; and MGH Biostatistics Center (H.L.), Massachusetts General Hospital and Harvard Medical Center, Boston, Massachusetts 02114
| | - Walter R Frontera
- Program in Nutritional Metabolism and Neuroendocrine Unit (H.M., T.L.S., C.S., S.S., L.R.B., S.E.L., M.N.F., S.K.G.), Massachusetts General Hospital, Boston, Massachusetts 02114; Harvard Medical School (H.M., T.L.S., A.L.D.S.-C., L.R.B., S.E.L., M.T., H.L., M.-E.P., S.K.G.), Boston, Massachusetts 02115; Pediatric Endocrine Unit (T.L.S., L.R.B.), Massachusetts General Hospital, Boston, Massachusetts 02114; Research Division (A.L.D.S.-C., M.-E.P.), Joslin Diabetes Center, Boston, Massachusetts 02215; Department of Physical Medicine and Rehabilitation (W.R.F.), Vanderbilt University Medical Center, Nashville, Tennessee 37212; Department of Physical Medicine and Rehabilitation (W.R.F.), Harvard Medical School/Spaulding Rehabilitation Hospital, Boston, Massachusetts 02114; Department of Physiology (W.R.F.), University of Puerto Rico School of Medicine, San Juan, Puerto Rico 00936; Department of Radiology (M.T.), Massachusetts General Hospital, Boston, Massachusetts 02114; and MGH Biostatistics Center (H.L.), Massachusetts General Hospital and Harvard Medical Center, Boston, Massachusetts 02114
| | - Stephanie Syu
- Program in Nutritional Metabolism and Neuroendocrine Unit (H.M., T.L.S., C.S., S.S., L.R.B., S.E.L., M.N.F., S.K.G.), Massachusetts General Hospital, Boston, Massachusetts 02114; Harvard Medical School (H.M., T.L.S., A.L.D.S.-C., L.R.B., S.E.L., M.T., H.L., M.-E.P., S.K.G.), Boston, Massachusetts 02115; Pediatric Endocrine Unit (T.L.S., L.R.B.), Massachusetts General Hospital, Boston, Massachusetts 02114; Research Division (A.L.D.S.-C., M.-E.P.), Joslin Diabetes Center, Boston, Massachusetts 02215; Department of Physical Medicine and Rehabilitation (W.R.F.), Vanderbilt University Medical Center, Nashville, Tennessee 37212; Department of Physical Medicine and Rehabilitation (W.R.F.), Harvard Medical School/Spaulding Rehabilitation Hospital, Boston, Massachusetts 02114; Department of Physiology (W.R.F.), University of Puerto Rico School of Medicine, San Juan, Puerto Rico 00936; Department of Radiology (M.T.), Massachusetts General Hospital, Boston, Massachusetts 02114; and MGH Biostatistics Center (H.L.), Massachusetts General Hospital and Harvard Medical Center, Boston, Massachusetts 02114
| | - Laurie R Braun
- Program in Nutritional Metabolism and Neuroendocrine Unit (H.M., T.L.S., C.S., S.S., L.R.B., S.E.L., M.N.F., S.K.G.), Massachusetts General Hospital, Boston, Massachusetts 02114; Harvard Medical School (H.M., T.L.S., A.L.D.S.-C., L.R.B., S.E.L., M.T., H.L., M.-E.P., S.K.G.), Boston, Massachusetts 02115; Pediatric Endocrine Unit (T.L.S., L.R.B.), Massachusetts General Hospital, Boston, Massachusetts 02114; Research Division (A.L.D.S.-C., M.-E.P.), Joslin Diabetes Center, Boston, Massachusetts 02215; Department of Physical Medicine and Rehabilitation (W.R.F.), Vanderbilt University Medical Center, Nashville, Tennessee 37212; Department of Physical Medicine and Rehabilitation (W.R.F.), Harvard Medical School/Spaulding Rehabilitation Hospital, Boston, Massachusetts 02114; Department of Physiology (W.R.F.), University of Puerto Rico School of Medicine, San Juan, Puerto Rico 00936; Department of Radiology (M.T.), Massachusetts General Hospital, Boston, Massachusetts 02114; and MGH Biostatistics Center (H.L.), Massachusetts General Hospital and Harvard Medical Center, Boston, Massachusetts 02114
| | - Sara E Looby
- Program in Nutritional Metabolism and Neuroendocrine Unit (H.M., T.L.S., C.S., S.S., L.R.B., S.E.L., M.N.F., S.K.G.), Massachusetts General Hospital, Boston, Massachusetts 02114; Harvard Medical School (H.M., T.L.S., A.L.D.S.-C., L.R.B., S.E.L., M.T., H.L., M.-E.P., S.K.G.), Boston, Massachusetts 02115; Pediatric Endocrine Unit (T.L.S., L.R.B.), Massachusetts General Hospital, Boston, Massachusetts 02114; Research Division (A.L.D.S.-C., M.-E.P.), Joslin Diabetes Center, Boston, Massachusetts 02215; Department of Physical Medicine and Rehabilitation (W.R.F.), Vanderbilt University Medical Center, Nashville, Tennessee 37212; Department of Physical Medicine and Rehabilitation (W.R.F.), Harvard Medical School/Spaulding Rehabilitation Hospital, Boston, Massachusetts 02114; Department of Physiology (W.R.F.), University of Puerto Rico School of Medicine, San Juan, Puerto Rico 00936; Department of Radiology (M.T.), Massachusetts General Hospital, Boston, Massachusetts 02114; and MGH Biostatistics Center (H.L.), Massachusetts General Hospital and Harvard Medical Center, Boston, Massachusetts 02114
| | - Meghan N Feldpausch
- Program in Nutritional Metabolism and Neuroendocrine Unit (H.M., T.L.S., C.S., S.S., L.R.B., S.E.L., M.N.F., S.K.G.), Massachusetts General Hospital, Boston, Massachusetts 02114; Harvard Medical School (H.M., T.L.S., A.L.D.S.-C., L.R.B., S.E.L., M.T., H.L., M.-E.P., S.K.G.), Boston, Massachusetts 02115; Pediatric Endocrine Unit (T.L.S., L.R.B.), Massachusetts General Hospital, Boston, Massachusetts 02114; Research Division (A.L.D.S.-C., M.-E.P.), Joslin Diabetes Center, Boston, Massachusetts 02215; Department of Physical Medicine and Rehabilitation (W.R.F.), Vanderbilt University Medical Center, Nashville, Tennessee 37212; Department of Physical Medicine and Rehabilitation (W.R.F.), Harvard Medical School/Spaulding Rehabilitation Hospital, Boston, Massachusetts 02114; Department of Physiology (W.R.F.), University of Puerto Rico School of Medicine, San Juan, Puerto Rico 00936; Department of Radiology (M.T.), Massachusetts General Hospital, Boston, Massachusetts 02114; and MGH Biostatistics Center (H.L.), Massachusetts General Hospital and Harvard Medical Center, Boston, Massachusetts 02114
| | - Martin Torriani
- Program in Nutritional Metabolism and Neuroendocrine Unit (H.M., T.L.S., C.S., S.S., L.R.B., S.E.L., M.N.F., S.K.G.), Massachusetts General Hospital, Boston, Massachusetts 02114; Harvard Medical School (H.M., T.L.S., A.L.D.S.-C., L.R.B., S.E.L., M.T., H.L., M.-E.P., S.K.G.), Boston, Massachusetts 02115; Pediatric Endocrine Unit (T.L.S., L.R.B.), Massachusetts General Hospital, Boston, Massachusetts 02114; Research Division (A.L.D.S.-C., M.-E.P.), Joslin Diabetes Center, Boston, Massachusetts 02215; Department of Physical Medicine and Rehabilitation (W.R.F.), Vanderbilt University Medical Center, Nashville, Tennessee 37212; Department of Physical Medicine and Rehabilitation (W.R.F.), Harvard Medical School/Spaulding Rehabilitation Hospital, Boston, Massachusetts 02114; Department of Physiology (W.R.F.), University of Puerto Rico School of Medicine, San Juan, Puerto Rico 00936; Department of Radiology (M.T.), Massachusetts General Hospital, Boston, Massachusetts 02114; and MGH Biostatistics Center (H.L.), Massachusetts General Hospital and Harvard Medical Center, Boston, Massachusetts 02114
| | - Hang Lee
- Program in Nutritional Metabolism and Neuroendocrine Unit (H.M., T.L.S., C.S., S.S., L.R.B., S.E.L., M.N.F., S.K.G.), Massachusetts General Hospital, Boston, Massachusetts 02114; Harvard Medical School (H.M., T.L.S., A.L.D.S.-C., L.R.B., S.E.L., M.T., H.L., M.-E.P., S.K.G.), Boston, Massachusetts 02115; Pediatric Endocrine Unit (T.L.S., L.R.B.), Massachusetts General Hospital, Boston, Massachusetts 02114; Research Division (A.L.D.S.-C., M.-E.P.), Joslin Diabetes Center, Boston, Massachusetts 02215; Department of Physical Medicine and Rehabilitation (W.R.F.), Vanderbilt University Medical Center, Nashville, Tennessee 37212; Department of Physical Medicine and Rehabilitation (W.R.F.), Harvard Medical School/Spaulding Rehabilitation Hospital, Boston, Massachusetts 02114; Department of Physiology (W.R.F.), University of Puerto Rico School of Medicine, San Juan, Puerto Rico 00936; Department of Radiology (M.T.), Massachusetts General Hospital, Boston, Massachusetts 02114; and MGH Biostatistics Center (H.L.), Massachusetts General Hospital and Harvard Medical Center, Boston, Massachusetts 02114
| | - Mary-Elizabeth Patti
- Program in Nutritional Metabolism and Neuroendocrine Unit (H.M., T.L.S., C.S., S.S., L.R.B., S.E.L., M.N.F., S.K.G.), Massachusetts General Hospital, Boston, Massachusetts 02114; Harvard Medical School (H.M., T.L.S., A.L.D.S.-C., L.R.B., S.E.L., M.T., H.L., M.-E.P., S.K.G.), Boston, Massachusetts 02115; Pediatric Endocrine Unit (T.L.S., L.R.B.), Massachusetts General Hospital, Boston, Massachusetts 02114; Research Division (A.L.D.S.-C., M.-E.P.), Joslin Diabetes Center, Boston, Massachusetts 02215; Department of Physical Medicine and Rehabilitation (W.R.F.), Vanderbilt University Medical Center, Nashville, Tennessee 37212; Department of Physical Medicine and Rehabilitation (W.R.F.), Harvard Medical School/Spaulding Rehabilitation Hospital, Boston, Massachusetts 02114; Department of Physiology (W.R.F.), University of Puerto Rico School of Medicine, San Juan, Puerto Rico 00936; Department of Radiology (M.T.), Massachusetts General Hospital, Boston, Massachusetts 02114; and MGH Biostatistics Center (H.L.), Massachusetts General Hospital and Harvard Medical Center, Boston, Massachusetts 02114
| | - Steven K Grinspoon
- Program in Nutritional Metabolism and Neuroendocrine Unit (H.M., T.L.S., C.S., S.S., L.R.B., S.E.L., M.N.F., S.K.G.), Massachusetts General Hospital, Boston, Massachusetts 02114; Harvard Medical School (H.M., T.L.S., A.L.D.S.-C., L.R.B., S.E.L., M.T., H.L., M.-E.P., S.K.G.), Boston, Massachusetts 02115; Pediatric Endocrine Unit (T.L.S., L.R.B.), Massachusetts General Hospital, Boston, Massachusetts 02114; Research Division (A.L.D.S.-C., M.-E.P.), Joslin Diabetes Center, Boston, Massachusetts 02215; Department of Physical Medicine and Rehabilitation (W.R.F.), Vanderbilt University Medical Center, Nashville, Tennessee 37212; Department of Physical Medicine and Rehabilitation (W.R.F.), Harvard Medical School/Spaulding Rehabilitation Hospital, Boston, Massachusetts 02114; Department of Physiology (W.R.F.), University of Puerto Rico School of Medicine, San Juan, Puerto Rico 00936; Department of Radiology (M.T.), Massachusetts General Hospital, Boston, Massachusetts 02114; and MGH Biostatistics Center (H.L.), Massachusetts General Hospital and Harvard Medical Center, Boston, Massachusetts 02114
| |
Collapse
|
13
|
AMPK maintains energy homeostasis and survival in cancer cells via regulating p38/PGC-1α-mediated mitochondrial biogenesis. Cell Death Discov 2015; 1:15063. [PMID: 27551487 PMCID: PMC4979508 DOI: 10.1038/cddiscovery.2015.63] [Citation(s) in RCA: 99] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/01/2015] [Revised: 11/05/2015] [Accepted: 11/06/2015] [Indexed: 12/13/2022] Open
Abstract
Cancer cells exhibit unique metabolic response and adaptation to the fluctuating microenvironment, yet molecular and biochemical events imprinting this phenomenon are unclear. Here, we show that metabolic homeostasis and adaptation to metabolic stress in cancer cells are primarily achieved by an integrated response exerted by the activation of AMPK. We provide evidence that AMPK-p38-PGC-1α axis, by regulating energy homeostasis, maintains survival in cancer cells under glucose-limiting conditions. Functioning as a molecular switch, AMPK promotes glycolysis by activating PFK2, and facilitates mitochondrial metabolism of non-glucose carbon sources thereby maintaining cellular ATP level. Interestingly, we noted that AMPK can promote oxidative metabolism via increasing mitochondrial biogenesis and OXPHOS capacity via regulating expression of PGC-1α through p38MAPK activation. Taken together, our study signifies the fundamental role of AMPK in controlling cellular bioenergetics and mitochondrial biogenesis in cancer cells.
Collapse
|
14
|
He X, Duan Y, Yao K, Li F, Hou Y, Wu G, Yin Y. β-Hydroxy-β-methylbutyrate, mitochondrial biogenesis, and skeletal muscle health. Amino Acids 2015; 48:653-664. [PMID: 26573541 DOI: 10.1007/s00726-015-2126-7] [Citation(s) in RCA: 43] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/12/2015] [Accepted: 11/02/2015] [Indexed: 12/16/2022]
Abstract
The metabolic roles of mitochondria go far beyond serving exclusively as the major producer of ATP in tissues and cells. Evidence has shown that mitochondria may function as a key regulator of skeletal muscle fiber types and overall well-being. Maintaining skeletal muscle mitochondrial content and function is important for sustaining health throughout the lifespan. Of great importance, β-hydroxy-β-methylbutyrate (HMB, a metabolite of L-leucine) has been proposed to enhance the protein deposition and efficiency of mitochondrial biogenesis in skeletal muscle, as well as muscle strength in both exercise and clinical settings. Specifically, dietary supplementation with HMB increases the gene expression of peroxisome proliferator-activated receptor gamma co-activator 1-alpha (PGC-1α), which represents an upstream inducer of genes of mitochondrial metabolism, coordinates the expression of both nuclear- and mitochondrion-encoded genes in mitochondrial biogenesis. Additionally, PGC-1α plays a key role in the transformation of skeletal muscle fiber type, leading to a shift toward type I muscle fibers that are rich in mitochondria and have a high capacity for oxidative metabolism. As a nitrogen-free metabolite, HMB holds great promise to improve skeletal muscle mass and function, as well as whole-body health and well-being of animals and humans.
Collapse
Affiliation(s)
- Xi He
- College of Animal Science and Technology, Hunan Agricultural University, Changsha, 410128, China.,Hunan Co-Innovation Center of Animal Production Safety, Changsha, 410128, China
| | - Yehui Duan
- Scientific Observation and Experiment Station of Animal Nutrition and Feed Science in South-Central China, Ministry of Agriculture, Hunan Provincial Engineering Research Center for Healthy Livestock and Poultry Production, Key Laboratory of Agro-ecological Processes in Subtropical Region, Institute of Subtropical Agriculture, Chinese Academy of Sciences, No. 644 Yuanda Road, Furong District, Changsha, 410125, Hunan, China.,University of Chinese Academy of Sciences, Beijing, 100039, China
| | - Kang Yao
- College of Animal Science and Technology, Hunan Agricultural University, Changsha, 410128, China. .,Scientific Observation and Experiment Station of Animal Nutrition and Feed Science in South-Central China, Ministry of Agriculture, Hunan Provincial Engineering Research Center for Healthy Livestock and Poultry Production, Key Laboratory of Agro-ecological Processes in Subtropical Region, Institute of Subtropical Agriculture, Chinese Academy of Sciences, No. 644 Yuanda Road, Furong District, Changsha, 410125, Hunan, China.
| | - Fengna Li
- Scientific Observation and Experiment Station of Animal Nutrition and Feed Science in South-Central China, Ministry of Agriculture, Hunan Provincial Engineering Research Center for Healthy Livestock and Poultry Production, Key Laboratory of Agro-ecological Processes in Subtropical Region, Institute of Subtropical Agriculture, Chinese Academy of Sciences, No. 644 Yuanda Road, Furong District, Changsha, 410125, Hunan, China
| | - Yongqing Hou
- Hubei Collaborative Innovation Center for Animal Nutrition and Feed Safety, Hubei Key Laboratory of Animal Nutrition and Feed Science, Wuhan Polytechnic University, Wuhan, 430023, China
| | - Guoyao Wu
- Scientific Observation and Experiment Station of Animal Nutrition and Feed Science in South-Central China, Ministry of Agriculture, Hunan Provincial Engineering Research Center for Healthy Livestock and Poultry Production, Key Laboratory of Agro-ecological Processes in Subtropical Region, Institute of Subtropical Agriculture, Chinese Academy of Sciences, No. 644 Yuanda Road, Furong District, Changsha, 410125, Hunan, China.,Hubei Collaborative Innovation Center for Animal Nutrition and Feed Safety, Hubei Key Laboratory of Animal Nutrition and Feed Science, Wuhan Polytechnic University, Wuhan, 430023, China.,Department of Animal Science, Texas A&M University, College Station, TX, 77843, USA
| | - Yulong Yin
- College of Animal Science and Technology, Hunan Agricultural University, Changsha, 410128, China. .,Scientific Observation and Experiment Station of Animal Nutrition and Feed Science in South-Central China, Ministry of Agriculture, Hunan Provincial Engineering Research Center for Healthy Livestock and Poultry Production, Key Laboratory of Agro-ecological Processes in Subtropical Region, Institute of Subtropical Agriculture, Chinese Academy of Sciences, No. 644 Yuanda Road, Furong District, Changsha, 410125, Hunan, China. .,Hubei Collaborative Innovation Center for Animal Nutrition and Feed Safety, Hubei Key Laboratory of Animal Nutrition and Feed Science, Wuhan Polytechnic University, Wuhan, 430023, China.
| |
Collapse
|
15
|
Péladeau C, Ahmed A, Amirouche A, Crawford Parks TE, Bronicki LM, Ljubicic V, Renaud JM, Jasmin BJ. Combinatorial therapeutic activation with heparin and AICAR stimulates additive effects on utrophin A expression in dystrophic muscles. Hum Mol Genet 2015; 25:24-43. [PMID: 26494902 DOI: 10.1093/hmg/ddv444] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/02/2015] [Accepted: 10/19/2015] [Indexed: 01/13/2023] Open
Abstract
Upregulation of utrophin A is an attractive therapeutic strategy for treating Duchenne muscular dystrophy (DMD). Over the years, several studies revealed that utrophin A is regulated by multiple transcriptional and post-transcriptional mechanisms, and that pharmacological modulation of these pathways stimulates utrophin A expression in dystrophic muscle. In particular, we recently showed that activation of p38 signaling causes an increase in the levels of utrophin A mRNAs and protein by decreasing the functional availability of the destabilizing RNA-binding protein called K-homology splicing regulatory protein, thereby resulting in increases in the stability of existing mRNAs. Here, we treated 6-week-old mdx mice for 4 weeks with the clinically used anticoagulant drug heparin known to activate p38 mitogen-activated protein kinase, and determined the impact of this pharmacological intervention on the dystrophic phenotype. Our results show that heparin treatment of mdx mice caused a significant ∼1.5- to 3-fold increase in utrophin A expression in diaphragm, extensor digitorum longus and tibialis anterior (TA) muscles. In agreement with these findings, heparin-treated diaphragm and TA muscle fibers showed an accumulation of utrophin A and β-dystroglycan along their sarcolemma and displayed improved morphology and structural integrity. Moreover, combinatorial drug treatment using both heparin and 5-amino-4-imidazolecarboxamide riboside (AICAR), the latter targeting 5' adenosine monophosphate-activated protein kinase and the transcriptional activation of utrophin A, caused an additive effect on utrophin A expression in dystrophic muscle. These findings establish that heparin is a relevant therapeutic agent for treating DMD, and illustrate that combinatorial treatment of heparin with AICAR may serve as an effective strategy to further increase utrophin A expression in dystrophic muscle via activation of distinct signaling pathways.
Collapse
Affiliation(s)
- Christine Péladeau
- Department of Cellular and Molecular Medicine and Centre for Neuromuscular Disease, Faculty of Medicine, University of Ottawa, Ottawa, Ontario, Canada
| | - Aatika Ahmed
- Department of Cellular and Molecular Medicine and Centre for Neuromuscular Disease, Faculty of Medicine, University of Ottawa, Ottawa, Ontario, Canada
| | - Adel Amirouche
- Department of Cellular and Molecular Medicine and Centre for Neuromuscular Disease, Faculty of Medicine, University of Ottawa, Ottawa, Ontario, Canada
| | - Tara E Crawford Parks
- Department of Cellular and Molecular Medicine and Centre for Neuromuscular Disease, Faculty of Medicine, University of Ottawa, Ottawa, Ontario, Canada
| | - Lucas M Bronicki
- Department of Cellular and Molecular Medicine and Centre for Neuromuscular Disease, Faculty of Medicine, University of Ottawa, Ottawa, Ontario, Canada
| | - Vladimir Ljubicic
- Department of Cellular and Molecular Medicine and Centre for Neuromuscular Disease, Faculty of Medicine, University of Ottawa, Ottawa, Ontario, Canada
| | - Jean-Marc Renaud
- Department of Cellular and Molecular Medicine and Centre for Neuromuscular Disease, Faculty of Medicine, University of Ottawa, Ottawa, Ontario, Canada
| | - Bernard J Jasmin
- Department of Cellular and Molecular Medicine and Centre for Neuromuscular Disease, Faculty of Medicine, University of Ottawa, Ottawa, Ontario, Canada
| |
Collapse
|
16
|
Al-Rewashdy H, Ljubicic V, Lin W, Renaud JM, Jasmin BJ. Utrophin A is essential in mediating the functional adaptations of mdx mouse muscle following chronic AMPK activation. Hum Mol Genet 2014; 24:1243-55. [PMID: 25324540 DOI: 10.1093/hmg/ddu535] [Citation(s) in RCA: 37] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/16/2023] Open
Abstract
Duchenne muscular dystrophy (DMD) is caused by the absence of dystrophin along muscle fibers. An attractive therapeutic avenue for DMD consists in the upregulation of utrophin A, a protein with high sequence identity and functional redundancy with dystrophin. Recent work has shown that pharmacological interventions that induce a muscle fiber shift toward a slower, more oxidative phenotype with increased expression of utrophin A confer morphological and functional improvements in mdx mice. Whether such improvements result from the increased expression of utrophin A per se or are linked to other beneficial adaptations associated with the slow, oxidative phenotype remain to be established. To address this central issue, we capitalized on the use of double knockout (dKO) mice, which are mdx mice also deficient in utrophin. We first compared expression of signaling molecules and markers of the slow, oxidative phenotype in muscles of mdx versus dKO mice and found that both strains exhibit similar phenotypes. Chronic activation of 5' adenosine monophosphate-activated protein kinase with 5-amino-4-imidazolecarboxamide riboside (AICAR) resulted in expression of a slower, more oxidative phenotype in both mdx and dKO mice. In mdx mice, this fiber type shift was accompanied by clear functional improvements that included reductions in central nucleation, IgM sarcoplasmic penetration and sarcolemmal damage resulting from eccentric contractions, as well as in increased grip strength. These important morphological and functional adaptations were not seen in AICAR-treated dKO mice. Our findings show the central role of utrophin A in mediating the functional benefits associated with expression of a slower, more oxidative phenotype in dystrophic animals.
Collapse
Affiliation(s)
- Hasanen Al-Rewashdy
- Department of Cellular and Molecular Medicine, and Centre for Neuromuscular Disease, Faculty of Medicine, University of Ottawa, Ottawa, Ontario, Canada
| | - Vladimir Ljubicic
- Department of Cellular and Molecular Medicine, and Centre for Neuromuscular Disease, Faculty of Medicine, University of Ottawa, Ottawa, Ontario, Canada
| | - Wei Lin
- Department of Cellular and Molecular Medicine, and Centre for Neuromuscular Disease, Faculty of Medicine, University of Ottawa, Ottawa, Ontario, Canada
| | - Jean-Marc Renaud
- Department of Cellular and Molecular Medicine, and Centre for Neuromuscular Disease, Faculty of Medicine, University of Ottawa, Ottawa, Ontario, Canada
| | - Bernard J Jasmin
- Department of Cellular and Molecular Medicine, and Centre for Neuromuscular Disease, Faculty of Medicine, University of Ottawa, Ottawa, Ontario, Canada
| |
Collapse
|
17
|
Pauly M, Chabi B, Favier FB, Vanterpool F, Matecki S, Fouret G, Bonafos B, Vernus B, Feillet-Coudray C, Coudray C, Bonnieu A, Ramonatxo C. Combined Strategies for Maintaining Skeletal Muscle Mass and Function in Aging: Myostatin Inactivation and AICAR-Associated Oxidative Metabolism Induction. J Gerontol A Biol Sci Med Sci 2014; 70:1077-87. [PMID: 25227129 DOI: 10.1093/gerona/glu147] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/30/2014] [Accepted: 07/21/2014] [Indexed: 11/13/2022] Open
Abstract
Myostatin (mstn) blockade, resulting in muscle hypertrophy, is a promising therapy to counteract age-related muscle loss. However, oxidative and mitochondrial deficit observed in young mice with myostatin inhibition could be detrimental with aging. The aim of this study was (a) to bring original data on metabolic and mitochondrial consequences of mstn inhibition in old mice, and (b) to examine whether 4-weeks of AICAR treatment, a pharmacological compound known to upregulate oxidative metabolism, may be useful to improve exercise capacity and mitochondrial deficit of 20-months mstn KO versus wild-type (WT) mice. Our results show that despite the enlarged muscle mass, the oxidative and mitochondrial deficit associated with reduced endurance running capacity is maintained in old mstn KO mice but not worsened by aging. Importantly, AICAR treatment induced a significant beneficial effect on running limit time only in old mstn KO mice, with a marked increase in PGC-1α expression and slight beneficial effects on mitochondrial function. We showed that AICAR effects were autophagy-independent. This study underlines the relevance of aged muscle remodelling by complementary approaches that impact both muscle mass and function, and suggest that mstn inhibition and aerobic metabolism activators should be co-developed for delaying age-related deficits in skeletal muscle.
Collapse
Affiliation(s)
- Marion Pauly
- INRA, UMR866 Dynamique Musculaire et Métabolisme, Université Montpellier 1, F-34060, Montpellier, France INSERM U1046, Physiology and Experimental Medicine Heart-Muscle Unit, Université Montpellier 1, Université Montpellier 2, Montpellier, France
| | - Béatrice Chabi
- INRA, UMR866 Dynamique Musculaire et Métabolisme, Université Montpellier 1, F-34060, Montpellier, France
| | - François Bertrand Favier
- INRA, UMR866 Dynamique Musculaire et Métabolisme, Université Montpellier 1, F-34060, Montpellier, France
| | - Frankie Vanterpool
- INRA, UMR866 Dynamique Musculaire et Métabolisme, Université Montpellier 1, F-34060, Montpellier, France
| | - Stefan Matecki
- INSERM U1046, Physiology and Experimental Medicine Heart-Muscle Unit, Université Montpellier 1, Université Montpellier 2, Montpellier, France
| | - Gilles Fouret
- INRA, UMR866 Dynamique Musculaire et Métabolisme, Université Montpellier 1, F-34060, Montpellier, France
| | - Béatrice Bonafos
- INRA, UMR866 Dynamique Musculaire et Métabolisme, Université Montpellier 1, F-34060, Montpellier, France
| | - Barbara Vernus
- INRA, UMR866 Dynamique Musculaire et Métabolisme, Université Montpellier 1, F-34060, Montpellier, France
| | - Christine Feillet-Coudray
- INRA, UMR866 Dynamique Musculaire et Métabolisme, Université Montpellier 1, F-34060, Montpellier, France
| | - Charles Coudray
- INRA, UMR866 Dynamique Musculaire et Métabolisme, Université Montpellier 1, F-34060, Montpellier, France
| | - Anne Bonnieu
- INRA, UMR866 Dynamique Musculaire et Métabolisme, Université Montpellier 1, F-34060, Montpellier, France
| | - Christelle Ramonatxo
- INRA, UMR866 Dynamique Musculaire et Métabolisme, Université Montpellier 1, F-34060, Montpellier, France
| |
Collapse
|
18
|
Zhu W, Chen S, Li Z, Zhao X, Li W, Sun Y, Zhang Z, Ling W, Feng X. Effects and mechanisms of resveratrol on the amelioration of oxidative stress and hepatic steatosis in KKAy mice. Nutr Metab (Lond) 2014; 11:35. [PMID: 25140191 PMCID: PMC4137107 DOI: 10.1186/1743-7075-11-35] [Citation(s) in RCA: 66] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/23/2014] [Accepted: 08/06/2014] [Indexed: 02/07/2023] Open
Abstract
Background The exact mechanism of the protective role of Resveratrol (Res) in lipid metabolism and oxidative stress is not well elucidated. The present study aimed to investigate the potential benefits and possible mechanisms of Res on the amelioration of oxidative stress and hepatic steatosis in a KKAy mouse model. Methods A total of 30 KKAy male mice were randomly divided into three groups: a normal chow group, a low resveratrol group and a high resveratrol group. After a 12-wk study period, serum levels of TG, TC, LDL-C and HDL-C, the liver content of TG and TC, ROS, GSH, GPx, SOD and MDA levels were measured. Ectopic lipid deposition was observed in sectioned frozen liver tissues. The mRNA levels of ATGL and HSL in the liver tissues were determined via real-time PCR. Furthermore, the protein expression of p47phox, gp91phox, ATGL, HSL, Sirt1, AMPK and FOXO1 were analyzed using western blotting. Results Following Res supplementation, serum levels of TG and MDA were decreased, while the HDL-C and SOD levels were increased in KKAy mice. Furthermore, Res treatment increased GSH and GPx in liver tissues, while it decreased ROS. In addition, Res significantly reduced hepatic steatosis. After Res treatment, concentrations of p47phox (membrane) and gp91phox proteins were reduced, while p-HSL, HSL and ATGL protein expression levels were increased. Mechanistically, the levels of Sirt1, p-AMPK and p-FOXO1 expression in the liver tissues were up-regulated following supplementation with Res, and FOXO1 protein was released from the nucleus into the cytoplasm. Conclusions Res is able to attenuate hepatic steatosis and lipid metabolic disorder and enhance the antioxidant ability in KKAy mice, possibly by up-regulating Sirt1 expression and the phosphorylation of AMPK.
Collapse
Affiliation(s)
- Wei Zhu
- Guangzhou Center for Disease Control and Prevention, Guangzhou, Guangdong, People's Republic of China
| | - Sifan Chen
- School of Public Health, Sun Yat-Sen University, Guangzhou, Guangdong, People's Republic of China.,Guangdong Provincial Key Laboratory of Food, Nutrition and Health, Guangzhou, Guangdong, People's Republic of China.,Guangzhou Center for Disease Control and Prevention, Guangzhou, Guangdong, People's Republic of China
| | - Zilun Li
- Division of Vascular Surgery, The First Affiliated Hospital, Sun Yat-sen University, Guangzhou, Guangdong, People's Republic of China
| | - Xiaohong Zhao
- Department of Nephrology, The First Affiliated Hospital, Sun Yat-sen University, Guangzhou, Guangdong, People's Republic of China
| | - Wenxue Li
- Guangzhou Center for Disease Control and Prevention, Guangzhou, Guangdong, People's Republic of China
| | - Yanshuang Sun
- School of Public Health, Sun Yat-Sen University, Guangzhou, Guangdong, People's Republic of China.,Guangdong Provincial Key Laboratory of Food, Nutrition and Health, Guangzhou, Guangdong, People's Republic of China
| | - Zili Zhang
- School of Public Health, Sun Yat-Sen University, Guangzhou, Guangdong, People's Republic of China.,Guangdong Provincial Key Laboratory of Food, Nutrition and Health, Guangzhou, Guangdong, People's Republic of China
| | - Wenhua Ling
- School of Public Health, Sun Yat-Sen University, Guangzhou, Guangdong, People's Republic of China.,Guangdong Provincial Key Laboratory of Food, Nutrition and Health, Guangzhou, Guangdong, People's Republic of China
| | - Xiang Feng
- School of Public Health, Sun Yat-Sen University, Guangzhou, Guangdong, People's Republic of China.,Guangdong Provincial Key Laboratory of Food, Nutrition and Health, Guangzhou, Guangdong, People's Republic of China
| |
Collapse
|
19
|
Tsutsumi R, Yoshida T, Nii Y, Okahisa N, Iwata S, Tsukayama M, Hashimoto R, Taniguchi Y, Sakaue H, Hosaka T, Shuto E, Sakai T. Sudachitin, a polymethoxylated flavone, improves glucose and lipid metabolism by increasing mitochondrial biogenesis in skeletal muscle. Nutr Metab (Lond) 2014; 11:32. [PMID: 25114710 PMCID: PMC4128574 DOI: 10.1186/1743-7075-11-32] [Citation(s) in RCA: 55] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/18/2014] [Accepted: 06/20/2014] [Indexed: 12/11/2022] Open
Abstract
Background Obesity is a major risk factor for insulin resistance, type 2 diabetes, and stroke. Flavonoids are effective antioxidants that protect against these chronic diseases. In this study, we evaluated the effects of sudachitin, a polymethoxylated flavonoid found in the skin of the Citrus sudachi fruit, on glucose, lipid, and energy metabolism in mice with high-fat diet-induced obesity and db/db diabetic mice. In our current study, we show that sudachitin improves metabolism and stimulates mitochondrial biogenesis, thereby increasing energy expenditure and reducing weight gain. Methods C57BL/6 J mice fed a high-fat diet (40% fat) and db/db mice fed a normal diet were treated orally with 5 mg/kg sudachitin or vehicle for 12 weeks. Following treatment, oxygen expenditure was assessed using indirect calorimetry, while glucose tolerance, insulin sensitivity, and indices of dyslipidemia were assessed by serum biochemistry. Quantitative polymerase chain reaction was used to determine the effect of sudachitin on the transcription of key metabolism-regulating genes in the skeletal muscle, liver, and white and brown adipose tissues. Primary myocytes were also prepared to examine the signaling mechanisms targeted by sudachitin in vitro. Results Sudachitin improved dyslipidemia, as evidenced by reduction in triglyceride and free fatty acid levels, and improved glucose tolerance and insulin resistance. It also enhanced energy expenditure and fatty acid β-oxidation by increasing mitochondrial biogenesis and function. The in vitro assay results suggest that sudachitin increased Sirt1 and PGC-1α expression in the skeletal muscle. Conclusions Sudachitin may improve dyslipidemia and metabolic syndrome by improving energy metabolism. Furthermore, it also induces mitochondrial biogenesis to protect against metabolic disorders.
Collapse
Affiliation(s)
- Rie Tsutsumi
- Department of Public Health and Applied and Nutrition, Institute of Health Bioscience, University of Tokushima, 3-18-15 Kuramoto, Tokushima 770-8503, Japan
| | - Tomomi Yoshida
- Department of Public Health and Applied and Nutrition, Institute of Health Bioscience, University of Tokushima, 3-18-15 Kuramoto, Tokushima 770-8503, Japan
| | - Yoshitaka Nii
- Tokushima Prefectural Industrial Technology Center, Tokushima, Japan
| | - Naoki Okahisa
- Tokushima Prefectural Industrial Technology Center, Tokushima, Japan
| | - Shinya Iwata
- Tokushima Prefectural Industrial Technology Center, Tokushima, Japan
| | - Masao Tsukayama
- Tokushima Prefectural Industrial Technology Center, Tokushima, Japan
| | - Rei Hashimoto
- Department of Public Health and Applied and Nutrition, Institute of Health Bioscience, University of Tokushima, 3-18-15 Kuramoto, Tokushima 770-8503, Japan
| | - Yasuko Taniguchi
- Department of Metabolism and Nutrition, Institute of Health Bioscience, University of Tokushima, Tokushima, Japan
| | - Hiroshi Sakaue
- Department of Metabolism and Nutrition, Institute of Health Bioscience, University of Tokushima, Tokushima, Japan
| | - Toshio Hosaka
- Department of Endocrinology and Diabetes, Department of General Internal Medicine, School of Medicine, Saitama Medical University, Saitama, Japan
| | - Emi Shuto
- Department of Public Health and Applied and Nutrition, Institute of Health Bioscience, University of Tokushima, 3-18-15 Kuramoto, Tokushima 770-8503, Japan
| | - Tohru Sakai
- Department of Public Health and Applied and Nutrition, Institute of Health Bioscience, University of Tokushima, 3-18-15 Kuramoto, Tokushima 770-8503, Japan
| |
Collapse
|
20
|
Stallings MT, Cardon BR, Hardman JM, Bliss TA, Brunson SE, Hart CM, Swiss MD, Hepworth SD, Christensen MJ, Hancock CR. A high isoflavone diet decreases 5′ adenosine monophosphate–activated protein kinase activation and does not correct selenium-induced elevations in fasting blood glucose in mice. Nutr Res 2014; 34:308-17. [DOI: 10.1016/j.nutres.2014.03.003] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/19/2013] [Revised: 03/07/2014] [Accepted: 03/10/2014] [Indexed: 12/31/2022]
|
21
|
Baltgalvis KA, White K, Li W, Claypool MD, Lang W, Alcantara R, Singh BK, Friera AM, McLaughlin J, Hansen D, McCaughey K, Nguyen H, Smith IJ, Godinez G, Shaw SJ, Goff D, Singh R, Markovtsov V, Sun TQ, Jenkins Y, Uy G, Li Y, Pan A, Gururaja T, Lau D, Park G, Hitoshi Y, Payan DG, Kinsella TM. Exercise performance and peripheral vascular insufficiency improve with AMPK activation in high-fat diet-fed mice. Am J Physiol Heart Circ Physiol 2014; 306:H1128-45. [PMID: 24561866 DOI: 10.1152/ajpheart.00839.2013] [Citation(s) in RCA: 33] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
Intermittent claudication is a form of exercise intolerance characterized by muscle pain during walking in patients with peripheral artery disease (PAD). Endothelial cell and muscle dysfunction are thought to be important contributors to the etiology of this disease, but a lack of preclinical models that incorporate these elements and measure exercise performance as a primary end point has slowed progress in finding new treatment options for these patients. We sought to develop an animal model of peripheral vascular insufficiency in which microvascular dysfunction and exercise intolerance were defining features. We further set out to determine if pharmacological activation of 5'-AMP-activated protein kinase (AMPK) might counteract any of these functional deficits. Mice aged on a high-fat diet demonstrate many functional and molecular characteristics of PAD, including the sequential development of peripheral vascular insufficiency, increased muscle fatigability, and progressive exercise intolerance. These changes occur gradually and are associated with alterations in nitric oxide bioavailability. Treatment of animals with an AMPK activator, R118, increased voluntary wheel running activity, decreased muscle fatigability, and prevented the progressive decrease in treadmill exercise capacity. These functional performance benefits were accompanied by improved mitochondrial function, the normalization of perfusion in exercising muscle, increased nitric oxide bioavailability, and decreased circulating levels of the endogenous endothelial nitric oxide synthase inhibitor asymmetric dimethylarginine. These data suggest that aged, obese mice represent a novel model for studying exercise intolerance associated with peripheral vascular insufficiency, and pharmacological activation of AMPK may be a suitable treatment for intermittent claudication associated with PAD.
Collapse
|
22
|
Mitochondrial stress signaling promotes cellular adaptations. Int J Cell Biol 2014; 2014:156020. [PMID: 24587804 PMCID: PMC3920668 DOI: 10.1155/2014/156020] [Citation(s) in RCA: 58] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/16/2013] [Accepted: 11/11/2013] [Indexed: 01/06/2023] Open
Abstract
Mitochondrial dysfunction has been implicated in the aetiology of many complex diseases, as well as the ageing process. Much of the research on mitochondrial dysfunction has focused on how mitochondrial damage may potentiate pathological phenotypes. The purpose of this review is to draw attention to the less well-studied mechanisms by which the cell adapts to mitochondrial perturbations. This involves communication of stress to the cell and successful induction of quality control responses, which include mitophagy, unfolded protein response, upregulation of antioxidant and DNA repair enzymes, morphological changes, and if all else fails apoptosis. The mitochondrion is an inherently stressful environment and we speculate that dysregulation of stress signaling or an inability to switch on these adaptations during times of mitochondrial stress may underpin mitochondrial dysfunction and hence amount to pathological states over time.
Collapse
|
23
|
Ljubicic V, Burt M, Jasmin BJ. The therapeutic potential of skeletal muscle plasticity in Duchenne muscular dystrophy: phenotypic modifiers as pharmacologic targets. FASEB J 2013; 28:548-68. [PMID: 24249639 DOI: 10.1096/fj.13-238071] [Citation(s) in RCA: 55] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
Duchenne muscular dystrophy (DMD) is a life-limiting, neuromuscular disorder that causes progressive, severe muscle wasting in boys and young men. Although there is no cure, scientists and clinicians can leverage the fact that slower, more oxidative skeletal muscle fibers possess an enhanced degree of resistance to the dystrophic pathology relative to their faster, more glycolytic counterparts, and can thus use this knowledge when investigating novel therapeutic avenues. Several factors have been identified as powerful regulators of muscle plasticity. Some proteins, such as calcineurin, peroxisome proliferator-activated receptor (PPAR) γ coactivator 1α (PGC-1α), PPARβ/δ, and AMP-activated protein kinase (AMPK), when chronically stimulated in animal models, remodel skeletal muscle toward the slow, oxidative myogenic program, whereas others, such as receptor-interacting protein 140 (RIP140) and E2F transcription factor 1 (E2F1), repress this phenotype. Recent studies demonstrating that pharmacologic and physiological activation of targets that shift dystrophic muscle toward the slow, oxidative myogenic program provide appreciable molecular and functional benefits. This review surveys the rationale behind, and evidence for, the study of skeletal muscle plasticity in preclinical models of DMD and highlights the potential therapeutic opportunities in advancing a strategy focused on remodeling skeletal muscle in patients with DMD toward the slow, oxidative phenotype.
Collapse
Affiliation(s)
- Vladimir Ljubicic
- 1Department of Cellular and Molecular Medicine, Faculty of Medicine, University of Ottawa, Ottawa, ON K1H 8M5, Canada.
| | | | | |
Collapse
|
24
|
LANE STEPHENC, ARETA JOSEL, BIRD STEPHENR, COFFEY VERNONG, BURKE LOUISEM, DESBROW BEN, KARAGOUNIS LEONIDASG, HAWLEY JOHNA. Caffeine Ingestion and Cycling Power Output in a Low or Normal Muscle Glycogen State. Med Sci Sports Exerc 2013; 45:1577-84. [DOI: 10.1249/mss.0b013e31828af183] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
|
25
|
AMP-activated protein kinase at the nexus of therapeutic skeletal muscle plasticity in Duchenne muscular dystrophy. Trends Mol Med 2013; 19:614-24. [PMID: 23891277 DOI: 10.1016/j.molmed.2013.07.002] [Citation(s) in RCA: 33] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/01/2013] [Revised: 06/26/2013] [Accepted: 07/01/2013] [Indexed: 12/22/2022]
Abstract
Recent studies have highlighted the potential of adenosine monophosphate-activated protein kinase (AMPK) to act as a central therapeutic target in Duchenne muscular dystrophy (DMD). Here, we review the role of AMPK as an important integrator of cell signaling pathways that mediate phenotypic plasticity within the context of dystrophic skeletal muscle. Pharmacological AMPK activation remodels skeletal muscle towards a slower, more oxidative phenotype, which is more pathologically resistant to the lack of dystrophin. Moreover, recent studies suggest that AMPK-activated autophagy may be beneficial for myofiber structure and function in mice with muscular dystrophy. Thus, AMPK may represent an ideal target for intervention because clinically approved pharmacological agonists exist, and because benefits can be derived via two independent yet, complementary biological pathways. The availability of several AMPK activators could therefore lead to the rapid development and implementation of novel and highly effective therapeutics aimed at altering the relentless progression of DMD.
Collapse
|
26
|
Henriksen BS, Curtis ME, Fillmore N, Cardon BR, Thomson DM, Hancock CR. The effects of chronic AMPK activation on hepatic triglyceride accumulation and glycerol 3-phosphate acyltransferase activity with high fat feeding. Diabetol Metab Syndr 2013; 5:29. [PMID: 23725555 PMCID: PMC3679947 DOI: 10.1186/1758-5996-5-29] [Citation(s) in RCA: 38] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/21/2012] [Accepted: 05/18/2013] [Indexed: 12/13/2022] Open
Abstract
BACKGROUND High fat feeding increases hepatic fat accumulation and is associated with hepatic insulin resistance. AMP Activated Protein Kinase (AMPK) is thought to inhibit lipid synthesis by the acute inhibition of glycerol-3-phosphate acyltransferase (GPAT) activity and transcriptional regulation via sterol regulatory element binding protein-1c (SREBP-1c). METHODS The purpose of this study was to determine if chronic activation of AMPK prevented an increase in GPAT1 activity in rats fed a high fat diet. Rats were fed a control (C), or a high fat (HF) diet (60% fat) for 6 weeks and injected with saline or a daily aminoimidazole carboxamide ribnucleotide (AICAR) dose of 0.5 mg/g body weight. RESULTS Chronic AMPK activation by AICAR injections resulted in a significant reduction in hepatic triglyceride accumulation in both the C and HF fed animals (C, 5.5±0.7; C+AICAR, 2.7 ±0.3; HF, 21.8±3.3; and HF+AICAR, 8.0±1.8 mg/g liver). HF feeding caused an increase in total GPAT and GPAT1 activity, which was not affected by chronic AMPK activation (GPAT1 activity vs. C, C+AICAR, 92±19%; HF, 186±43%; HF+AICAR, 234±62%). Markers of oxidative capacity, including citrate synthase activity and cytochrome c abundance, were not affected by chronic AICAR treatment. Interestingly, HF feeding caused a significant increase in long chain acyl-CoA dehydrogenase or LCAD (up 66% from C), a marker of fatty acid oxidation capacity. CONCLUSIONS These results suggest that chronic AMPK activation limits hepatic triglyceride accumulation independent of a reduction in total GPAT1 activity.
Collapse
Affiliation(s)
- Bradley S Henriksen
- Department of Nutrition, Dietetics, and Food Science, Brigham Young University, Provo, UT 84602, USA
| | - Mary E Curtis
- Department of Nutrition, Dietetics, and Food Science, Brigham Young University, Provo, UT 84602, USA
| | - Natasha Fillmore
- Department of Physiology and Developmental Biology, Brigham Young University, Provo, UT 84602, USA
| | - Brandon R Cardon
- Department of Nutrition, Dietetics, and Food Science, Brigham Young University, Provo, UT 84602, USA
| | - David M Thomson
- Department of Physiology and Developmental Biology, Brigham Young University, Provo, UT 84602, USA
| | - Chad R Hancock
- Department of Nutrition, Dietetics, and Food Science, Brigham Young University, Provo, UT 84602, USA
| |
Collapse
|
27
|
Merrill JF, Thomson DM, Hardman SE, Hepworth SD, Willie S, Hancock CR. Iron deficiency causes a shift in AMP-activated protein kinase (AMPK) subunit composition in rat skeletal muscle. Nutr Metab (Lond) 2012; 9:104. [PMID: 23171474 PMCID: PMC3575277 DOI: 10.1186/1743-7075-9-104] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/07/2012] [Accepted: 11/16/2012] [Indexed: 11/29/2022] Open
Abstract
Background As a cellular energy sensor, the 5’AMP-activated protein kinase (AMPK) is activated in response to energy stresses such as hypoxia and muscle contraction. To determine effects of iron deficiency on AMPK activation and signaling, as well as the AMPK subunit composition in skeletal muscle, rats were fed a control (C=50-58 mg/kg Fe) or iron deficient (ID=2-6 mg/kg Fe) diet for 6–8 wks. Results Their respective hematocrits were 47.5% ± 1.0 and 16.5% ± 0.6. Iron deficiency resulted in 28.3% greater muscle fatigue (p<0.01) in response to 10 min of stimulation (1 twitch/sec) and was associated with a greater reduction in phosphocreatine (C: Resting 24.1 ± 0.9 μmol/g, Stim 13.1 ± 1.5 μmol/g; ID: Resting 22.7 ± 1.0 μmol/g, Stim 3.2 ± 0.7 μmol/g; p<0.01) and ATP levels (C: Resting 5.89 ± 0.48 μmol/g, Stim 6.03 ± 0.35 μmol/g; ID: Resting 5.51 ± 0.20 μmol/g, Stim 4.19 ± 0.47 μmol/g; p<0.05). AMPK activation increased with stimulation in muscles of C and ID animals. A reduction in Cytochrome c and other iron-dependent mitochondrial proteins was observed in ID animals (p<0.01). The AMPK catalytic subunit (α) was examined because both isoforms are known to play different roles in responding to energy challenges. In ID animals, AMPKα2 subunit protein content was reduced to 71.6% of C (p<0.05), however this did not result in a significant difference in resting AMPKα2 activity. AMPKα1 protein was unchanged, however an overall increase in AMPKα1 activity was observed (C: 0.91 pmol/mg/min; ID: 1.63 pmol/mg/min; p<0.05). Resting phospho Acetyl CoA Carboxylase (pACC) was unchanged. In addition, we observed significant reductions in the β2 and γ3 subunits of AMPK in response to iron deficiency. Conclusions This study indicates that chronic iron deficiency causes a shift in the expression of AMPKα, β, and γ subunit composition. Iron deficiency also causes chronic activation of AMPK as well as an increase in AMPKα1 activity in exercised skeletal muscle.
Collapse
Affiliation(s)
- John F Merrill
- Department of Nutrition, Dietetics, and Food Science, Brigham Young University, Provo, Utah, USA.
| | | | | | | | | | | |
Collapse
|
28
|
Stephenson EJ, Camera DM, Jenkins TA, Kosari S, Lee JS, Hawley JA, Stepto NK. Skeletal muscle respiratory capacity is enhanced in rats consuming an obesogenic Western diet. Am J Physiol Endocrinol Metab 2012; 302:E1541-9. [PMID: 22496344 DOI: 10.1152/ajpendo.00590.2011] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
Obesity-induced lipid oversupply promotes skeletal muscle mitochondrial biogenesis. Previous investigations have utilized extreme high-fat diets (HFD) to induce such mitochondrial perturbations despite their disparity from human obesogenic diets. Here, we evaluate the effects of Western diet (WD)-induced obesity on skeletal muscle mitochondrial function. Long-Evans rats were given ad libitum access to either a WD [40% energy (E) from fat, 17% protein, and 43% carbohydrate (30% sucrose); n = 12] or a control diet (CON; 16% of E from fat, 21% protein, and 63% carbohydrate; n = 12) for 12 wk. Rats fed the WD consumed 23% more E than CON (P = 0.0001), which was associated with greater increases in body mass (23%, P = 0.0002) and adiposity (17%, P = 0.03). There were no differences in fasting blood glucose concentration or glucose tolerance between diets, although fasting insulin was increased by 40% (P = 0.007). Fasting serum triglycerides were also elevated in WD (86%, P = 0.001). The maximal capacity of the electron transfer system was greater following WD (37%, P = 0.02), as were the maximal activities of several mitochondrial enzymes (citrate synthase, β-hydroxyacyl-CoA dehydrogenase, carnitine palmitoyltransferase). Protein expression of citrate synthase, UCP3, and individual respiratory complexes was greater after WD (P < 0.05) despite no differences in the expression of peroxisome proliferator-activated receptor (PPAR)α, PPARδ, or PPARγ coactivator-1 mRNA or protein abundance. We conclude that the respiratory capacity of skeletal muscle is enhanced in response to the excess energy supplied by a WD. This is likely due to an increase in mitochondrial density, which at least in the short term, and in the absence of increased energy demand, may protect the tissue from lipid-induced impairments in glycemic control.
Collapse
Affiliation(s)
- Erin J Stephenson
- School of Medical Sciences, Royal Melbourne Institute of Technology University, Bundoora, Australia
| | | | | | | | | | | | | |
Collapse
|
29
|
Price NL, Gomes AP, Ling AJ, Duarte FV, Martin-Montalvo A, North BJ, Agarwal B, Ye L, Ramadori G, Teodoro JS, Hubbard BP, Varela AT, Davis JG, Varamini B, Hafner A, Moaddel R, Rolo AP, Coppari R, Palmeira CM, de Cabo R, Baur JA, Sinclair DA. SIRT1 is required for AMPK activation and the beneficial effects of resveratrol on mitochondrial function. Cell Metab 2012; 15:675-90. [PMID: 22560220 PMCID: PMC3545644 DOI: 10.1016/j.cmet.2012.04.003] [Citation(s) in RCA: 1132] [Impact Index Per Article: 94.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/11/2011] [Revised: 02/14/2012] [Accepted: 04/06/2012] [Indexed: 02/06/2023]
Abstract
Resveratrol induces mitochondrial biogenesis and protects against metabolic decline, but whether SIRT1 mediates these benefits is the subject of debate. To circumvent the developmental defects of germline SIRT1 knockouts, we have developed an inducible system that permits whole-body deletion of SIRT1 in adult mice. Mice treated with a moderate dose of resveratrol showed increased mitochondrial biogenesis and function, AMPK activation, and increased NAD(+) levels in skeletal muscle, whereas SIRT1 knockouts displayed none of these benefits. A mouse overexpressing SIRT1 mimicked these effects. A high dose of resveratrol activated AMPK in a SIRT1-independent manner, demonstrating that resveratrol dosage is a critical factor. Importantly, at both doses of resveratrol no improvements in mitochondrial function were observed in animals lacking SIRT1. Together these data indicate that SIRT1 plays an essential role in the ability of moderate doses of resveratrol to stimulate AMPK and improve mitochondrial function both in vitro and in vivo.
Collapse
Affiliation(s)
- Nathan L. Price
- Glenn Labs for the Biological Mechanisms of Aging, Harvard Medical School, Boston, MA, 02115
| | - Ana P. Gomes
- Glenn Labs for the Biological Mechanisms of Aging, Harvard Medical School, Boston, MA, 02115
- Center for Neurosciences and Cell Biology, 3004-517 Coimbra, Portugal
| | - Alvin J.Y. Ling
- Glenn Labs for the Biological Mechanisms of Aging, Harvard Medical School, Boston, MA, 02115
| | - Filipe V. Duarte
- Center for Neurosciences and Cell Biology, 3004-517 Coimbra, Portugal
| | - Alejandro Martin-Montalvo
- Laboratory of Experimental Gerontology, National Institute on Aging, National Institutes of Health, Baltimore, MD 21224, USA
| | - Brian J. North
- Glenn Labs for the Biological Mechanisms of Aging, Harvard Medical School, Boston, MA, 02115
| | - Beamon Agarwal
- Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA 19104
| | - Lan Ye
- Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA 19104
| | - Giorgio Ramadori
- Department of Internal Medicine, Division of Hypothalamic Research, The University of Texas Southwestern Medical Center, Dallas, TX 75390, USA
| | - Joao S. Teodoro
- Center for Neurosciences and Cell Biology, 3004-517 Coimbra, Portugal
| | - Basil P. Hubbard
- Glenn Labs for the Biological Mechanisms of Aging, Harvard Medical School, Boston, MA, 02115
| | - Ana T. Varela
- Center for Neurosciences and Cell Biology, 3004-517 Coimbra, Portugal
| | - James G. Davis
- Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA 19104
| | - Behzad Varamini
- Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA 19104
| | - Angela Hafner
- Glenn Labs for the Biological Mechanisms of Aging, Harvard Medical School, Boston, MA, 02115
| | - Ruin Moaddel
- Laboratory of Clinical Investigation, National Institute on Aging, National Institutes of Health, Baltimore, MD 21224, USA
| | - Anabela P. Rolo
- Center for Neurosciences and Cell Biology, 3004-517 Coimbra, Portugal
- Department of Biology, University of Aveiro, 3810-193, Aveiro Portugal
| | - Roberto Coppari
- Department of Internal Medicine, Division of Hypothalamic Research, The University of Texas Southwestern Medical Center, Dallas, TX 75390, USA
- Dipartimento di Medicina Sperimentale e Clinica, Universita’ Politecnica delle Marche, Ancona 60020, Italy
| | - Carlos M. Palmeira
- Center for Neurosciences and Cell Biology, 3004-517 Coimbra, Portugal
- Department of Life Sciences, Faculty of Science and Technology, University of Coimbra, 3004-517 Coimbra, Portugal
| | - Rafael de Cabo
- Laboratory of Experimental Gerontology, National Institute on Aging, National Institutes of Health, Baltimore, MD 21224, USA
| | - Joseph A. Baur
- Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA 19104
| | - David A. Sinclair
- Glenn Labs for the Biological Mechanisms of Aging, Harvard Medical School, Boston, MA, 02115
- Corresponding author: David A. Sinclair ()
| |
Collapse
|
30
|
Ploquin C, Chabi B, Fouret G, Vernus B, Feillet-Coudray C, Coudray C, Bonnieu A, Ramonatxo C. Lack of myostatin alters intermyofibrillar mitochondria activity, unbalances redox status, and impairs tolerance to chronic repetitive contractions in muscle. Am J Physiol Endocrinol Metab 2012; 302:E1000-8. [PMID: 22318951 DOI: 10.1152/ajpendo.00652.2011] [Citation(s) in RCA: 42] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
Abstract
Loss of myostatin (mstn) function leads to a decrease in mitochondrial content, a reduced expression of cytochrome c oxidase, and a lower citrate synthase activity in skeletal muscle. These data suggest functional or ultrastructural mitochondrial abnormalities that can impact on muscle endurance characteristics in such phenotype. To address this issue, we investigated subsarcolemmal and intermyofibrillar (IMF) mitochondrial activities, skeletal muscle redox homeostasis, and muscle fiber endurance quality in mstn-deficient mice [mstn knockout (KO)]. We report that lack of mstn induced a decrease in the coupling of IMF mitochondria respiration, with significantly higher basal oxygen consumption. No lysis of mitochondrial cristae or excessive swelling were observed in mstn KO mice compared with wild-type (WT) mice. Concerning redox status, mstn KO gastrocnemius exhibited a significant decrease in lipid peroxidation levels (-56%; P < 0.01 vs. WT) together with a significant upregulation of the antioxidant glutathione system. In contrast, superoxide dismutase and catalase activities were altered in mstn KO, gastrocnemius and soleus with a reduction of up to 80% compared with WT animals. The force production observed after contractile endurance test was significantly lower in extensor digitorum longus and soleus muscles of mstn KO mice compared with the controls (17 ± 3 and 36 ± 5% vs. 28 ± 4 and 56 ± 5%, respectively, P < 0.05). Together, these findings indicate that, besides an increased skeletal muscle mass, genetic mstn inhibition has differential effects on redox homeostasis and mitochondrial function that would have functional consequences on muscle response to endurance exercise.
Collapse
Affiliation(s)
- Claire Ploquin
- Institut National de la Recherche Agronomique, Dynamique Musculaire et Métabolisme, Montpellier, France
| | | | | | | | | | | | | | | |
Collapse
|
31
|
Frier BC, Wan Z, Williams DB, Stefanson AL, Wright DC. Epinephrine and AICAR-induced PGC-1α mRNA expression is intact in skeletal muscle from rats fed a high-fat diet. Am J Physiol Cell Physiol 2012; 302:C1772-9. [PMID: 22496244 DOI: 10.1152/ajpcell.00410.2011] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Peroxisome proliferator-activated receptor-γ coactivator-1α (PGC-1α) is a master regulator of mitochondrial biogenesis and is controlled, at least in part, through AMP-activated protein kinase and p38-dependent pathways. There is evidence demonstrating that activation of these kinases and induction of PGC-1α in skeletal muscle are regulated by catecholamines. The purpose of the present study was to determine if consumption of a high-fat diet (HFD) impairs epinephrine and 5-aminoimidazole-4-carboxamide-1β-d-ribofuranoside (AICAR) signaling and induction of PGC-1α in rat skeletal muscle. Male Wistar rats were fed chow or a HFD for 6 wk and then given a weight-adjusted bolus injection of epinephrine (20, 10, or 5 μg/100 g body wt sc) or saline, and triceps muscles were harvested 30 min (signaling) or 2 and 4 h (gene expression) postinjection. Despite blunted increases in p38 phosphorylation, the ability of epinephrine to induce PGC-1α was intact in skeletal muscle from HFD-fed rats and was associated with normal increases in activation of PKA and phosphorylation of cAMP response element-binding protein, reputed mediators of PGC-1α expression. The attenuated epinephrine-mediated increase in p38 phosphorylation was independent of increases in MAPK phosphatase 1. At 2 h following AICAR treatment (0.5 g/kg body wt sc), AMP-activated protein kinase and acetyl-CoA carboxylase phosphorylation were similar in skeletal muscle from chow- and HFD-fed rats. Surprisingly, AICAR-induced increases in PGC-1α mRNA levels were greater in skeletal muscle from HFD-fed rats. Our results demonstrate that the ability of epinephrine and AICAR to induce PGC-1α remains intact in skeletal muscle from HFD-fed rats. These results question the existence of reduced β-adrenergic responsiveness in diet-induced obesity and demonstrate that increases in p38 phosphorylation are not required for induction of PGC-1α in muscle from obese rats.
Collapse
Affiliation(s)
- Bruce C Frier
- Department of Agriculture, Food, and Nutritional Science, University of Alberta, Edmonton, Canada
| | | | | | | | | |
Collapse
|
32
|
Abbott MJ, Constantinescu S, Turcotte LP. AMP-activated protein kinase α2 is an essential signal in the regulation of insulin-stimulated fatty acid uptake in control-fed and high-fat-fed mice. Exp Physiol 2012; 97:603-17. [DOI: 10.1113/expphysiol.2012.064402] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
|
33
|
Stride N, Larsen S, Treebak JT, Hansen CN, Hey-Mogensen M, Speerschneider T, Jensen TE, Jeppesen J, Wojtaszewski JFP, Richter EA, Køber L, Dela F. 5'-AMP Activated Protein Kinase is Involved in the Regulation of Myocardial β-Oxidative Capacity in Mice. Front Physiol 2012; 3:33. [PMID: 22371704 PMCID: PMC3284200 DOI: 10.3389/fphys.2012.00033] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/12/2011] [Accepted: 02/06/2012] [Indexed: 11/23/2022] Open
Abstract
5′-adenosine monophosphate-activated protein kinase (AMPK) is considered central in regulation of energy status and substrate utilization within cells. In heart failure the energetic state is compromised and substrate metabolism is altered. We hypothesized that this could be linked to changes in AMPK activity and we therefore investigated mitochondrial oxidative phosphorylation capacity from the oxidation of long- and medium-chain fatty acids (LCFA and MCFA) in cardiomyocytes from young and old mice expressing a dominant negative AMPKα2 (AMPKα2-KD) construct and their wildtype (WT) littermates. We found a 35–45% (P < 0.05) lower mitochondrial capacity for oxidizing MCFA in AMPKα2-KD of both age-groups, compared to WT. This coincided with marked decreases in protein expression (19/29%, P < 0.05) and activity (14/21%, P < 0.05) of 3-hydroxyacyl-CoA-dehydrogenase (HAD), in young and old AMPKα2-KD mice, respectively, compared to WT. Maximal LCFA oxidation capacity was similar in AMPKα2-KD and WT mice independently of age implying that LCFA-transport into the mitochondria was unaffected by loss of AMPK activity or progressing age. Expression of regulatory proteins of glycolysis and glycogen breakdown showed equivocal effects of age and genotype. These results illustrate that AMPK is necessary for normal mitochondrial function in the heart and that decreased AMPK activity may lead to an altered energetic state as a consequence of reduced capacity to oxidize MCFA. We did not identify any clear aging effects on mitochondrial function.
Collapse
Affiliation(s)
- Nis Stride
- Xlab, Faculty of Health Sciences, Department of Biomedical Sciences, Center for Healthy Aging, University of Copenhagen Copenhagen, Denmark
| | | | | | | | | | | | | | | | | | | | | | | |
Collapse
|
34
|
Ljubicic V, Khogali S, Renaud JM, Jasmin BJ. Chronic AMPK stimulation attenuates adaptive signaling in dystrophic skeletal muscle. Am J Physiol Cell Physiol 2011; 302:C110-21. [PMID: 21940670 DOI: 10.1152/ajpcell.00183.2011] [Citation(s) in RCA: 41] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
In the present study, we evaluated how a pharmacologically induced phenotype shift in dystrophic skeletal muscle would affect subsequent intracellular signaling in response to a complementary, adaptive physiological stimulus. mdx mice were treated with the AMP-activated protein kinase (AMPK) activator 5-aminoimidazole-4-carboxamide-1-β-D-ribofuranoside (AICAR; 500 mg·kg(-1)·day(-1)) for 30 days, and then one-half of the animals were subjected to a bout of treadmill running to induce acute AMPK and p38 MAPK signaling. The mRNA levels of phenotypic modifiers, including peroxisome proliferator-activated receptor-δ (PPARδ), PPARγ coactivator-1α (PGC-1α), receptor interacting protein 140 (RIP 140), and silent information regulator two ortholog 1 (SIRT1) were assessed in skeletal muscle, as well as the expression of the protein arginine methyltransferase genes PRMT1 and CARM1. We found unique AMPK and p38 phosphorylation and expression signatures between dystrophic and healthy muscle. In dystrophic skeletal muscle, treadmill running induced PPARδ, PGC-1α, and SIRT1 mRNAs, three molecules that promote the slow, oxidative myogenic program. In the mdx animals that received the chronic AICAR treatment, running-elicited AMPK and p38 phosphorylation was attenuated compared with vehicle-treated mice. Similarly, acute stress-evoked expression of PPARδ, PGC-1α, and SIRT1 was also blunted by chronic pharmacological AMPK stimulation. Skeletal muscle PRMT1 and CARM1 protein contents were higher in mdx mice compared with wild-type littermates. The acute running-evoked induction of PRMT1 and CARM1 mRNAs was also attenuated by the AICAR treatment. Our data demonstrate that prior pharmacological conditioning is a salient determinant in how dystrophic muscle adapts to subsequent complementary, acute physiological stress stimuli. These results provide insight into possible therapeutic applications of synthetic agonists in neuromuscular diseases, such as during chronic administration to Duchenne muscular dystrophy patients.
Collapse
Affiliation(s)
- Vladimir Ljubicic
- Department of Cellular and Molecular Medicine, Faculty of Medicine, and Center for Neuromuscular Disease, University of Ottawa, Ottawa, Ontario, Canada.
| | | | | | | |
Collapse
|
35
|
Frier BC, Hancock CR, Little JP, Fillmore N, Bliss TA, Thomson DM, Wan Z, Wright DC. Reductions in RIP140 are not required for exercise- and AICAR-mediated increases in skeletal muscle mitochondrial content. J Appl Physiol (1985) 2011; 111:688-95. [PMID: 21700896 DOI: 10.1152/japplphysiol.00279.2011] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/20/2023] Open
Abstract
Receptor interacting protein 1 (RIP140) has recently been demonstrated to be a key player in the regulation of skeletal muscle mitochondrial content. We have shown that β-guanadinopropionic acid (β-GPA) feeding reduces RIP140 protein content and mRNA levels concomitant with increases in mitochondrial content (Williams DB, Sutherland LN, Bomhof MR, Basaraba SA, Thrush AB, Dyck DJ, Field CJ, Wright DC. Am J Physiol Endocrinol Metab 296: E1400-E1408, 2009). Since β-GPA feeding reduces high-energy phosphate levels and activates AMPK, alterations reminiscent of exercise, we hypothesized that exercise training would reduce RIP140 protein content. We further postulated that an acute bout of exercise, or interventions known to induce the expression of mitochondrial enzymes or genes involved in mitochondrial biogenesis, would result in decreases in nuclear RIP140 content. Two weeks of daily swim training increased markers of mitochondrial content in rat skeletal muscle independent of reductions in RIP140 protein. Similarly, high-intensity exercise training in humans failed to reduce RIP140 content despite increasing skeletal muscle mitochondrial enzymes. We found that 6 wk of daily 5-aminoimidazole-4-carboxamide-1-β-D-ribofuranoside (AICAR) injections had no effect on RIP140 protein content in rat skeletal muscle while RIP140 content from LKB1 knockout mice was unaltered despite reductions in mitochondria. An acute bout of exercise, AICAR treatment, and epinephrine injections increased the mRNA levels of PGC-1α, COXIV, and lipin1 independent of decreases in nuclear RIP140 protein. Surprisingly these interventions increased RIP140 mRNA expression. In conclusion our results demonstrate that decreases in RIP140 protein content are not required for exercise and AMPK-dependent increases in skeletal muscle mitochondrial content, nor do acute perturbations alter the cellular localization of RIP140 in parallel with the induction of genes involved in mitochondrial biogenesis.
Collapse
Affiliation(s)
- Bruce C Frier
- Alberta Diabetes Institute, University of Alberta, Edmonton, Alberta, Canada
| | | | | | | | | | | | | | | |
Collapse
|
36
|
Ljubicic V, Miura P, Burt M, Boudreault L, Khogali S, Lunde JA, Renaud JM, Jasmin BJ. Chronic AMPK activation evokes the slow, oxidative myogenic program and triggers beneficial adaptations in mdx mouse skeletal muscle. Hum Mol Genet 2011; 20:3478-93. [PMID: 21659335 DOI: 10.1093/hmg/ddr265] [Citation(s) in RCA: 130] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022] Open
Abstract
A therapeutic approach for Duchenne muscular dystrophy (DMD) is to up-regulate utrophin in skeletal muscle in an effort to compensate for the lack of dystrophin. We previously hypothesized that promotion of the slow, oxidative myogenic program, which triggers utrophin up-regulation, can attenuate the dystrophic pathology in mdx animals. Since treatment of healthy mice with the AMP-activated protein kinase (AMPK) activator 5-aminoimidazole-4-carboxamide-1-β-D-ribofuranoside (AICAR) enhances oxidative capacity and elicits a fast-to-slow fiber-type transition, we evaluated the effects of chronic AMPK stimulation on skeletal muscle phenotype and utrophin expression in mdx mice. Daily AICAR administration (500 mg/kg/day, 30 days) of 5-7-week-old mdx animals induced an elevation in mitochondrial cytochrome c oxidase enzyme activity, an increase in myosin heavy-chain type IIa-positive fibers and slower twitch contraction kinetics in the fast, glycolytic extensor digitorum longus muscle. Utrophin expression was significantly enhanced in response to AICAR, which occurred coincident with an elevated β-dystroglycan expression along the sarcolemma. These adaptations were associated with an increase in sarcolemmal structural integrity under basal conditions, as well as during damaging eccentric contractions ex vivo. Notably, peroxisome proliferator-activated receptor γ co-activator-1α (PGC-1α) and silent information regulator two ortholog 1 protein contents were significantly higher in muscle from mdx mice compared with wild-type littermates and AICAR further increased PGC-1α expression. Our data show that AICAR-evoked muscle plasticity results in beneficial phenotypic adaptations in mdx mice and suggest that the contextually novel application of this compound for muscular dystrophy warrants further study.
Collapse
Affiliation(s)
- Vladimir Ljubicic
- Department of Cellular and Molecular Medicine, Faculty of Medicine, Centre for Neuromuscular Disease, University of Ottawa, Ottawa, Ontario, Canada K1H 8M5
| | | | | | | | | | | | | | | |
Collapse
|
37
|
Stefanyk LE, Gulli RA, Ritchie IR, Chabowski A, Snook LA, Bonen A, Dyck DJ. Recovered insulin response by 2 weeks of leptin administration in high-fat fed rats is associated with restored AS160 activation and decreased reactive lipid accumulation. Am J Physiol Regul Integr Comp Physiol 2011; 301:R159-71. [PMID: 21525176 DOI: 10.1152/ajpregu.00636.2010] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Abstract
Leptin is an adipokine that increases fatty acid (FA) oxidation, decreases intramuscular lipid stores, and improves insulin response in skeletal muscle. In an attempt to elucidate the underlying mechanisms by which these metabolic changes occur, we administered leptin (Lep) or saline (Sal) by miniosmotic pumps to rats during the final 2 wk of a 6-wk low-fat (LF) or high-fat (HF) diet. Insulin-stimulated glucose transport was impaired by the HF diet (HF-Sal) but was restored with leptin administration (HF-Lep). This improvement was associated with restored phosphorylation of Akt and AS160 and decreased in reactive lipid species (ceramide, diacylglycerol), known inhibitors of the insulin-signaling cascade. Total muscle citrate synthase (CS) activity was increased by both leptin and HF diet, but was not additive. Leptin increased subsarcolemmal (SS) and intramyofibrillar (IMF) mitochondria CS activity. Total muscle, sarcolemmal, and mitochondrial (SS and IMF) FA transporter (FAT/CD36) protein content was significantly increased with the HF diet, but not altered by leptin. Therefore, the decrease in reactive lipid stores and subsequent improvement in insulin response, secondary to leptin administration in rats fed a HF diet was not due to a decrease in FA transport protein content or altered cellular distribution.
Collapse
Affiliation(s)
- Leslie E Stefanyk
- Dept. of Human Health and Nutritional Sciences, University of Guelph, Ontario, Canada, N1G 2W1
| | | | | | | | | | | | | |
Collapse
|
38
|
Frier BC, Jacobs RL, Wright DC. Interactions between the consumption of a high-fat diet and fasting in the regulation of fatty acid oxidation enzyme gene expression: an evaluation of potential mechanisms. Am J Physiol Regul Integr Comp Physiol 2011; 300:R212-21. [DOI: 10.1152/ajpregu.00367.2010] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
The consumption of high-fat diets (HFDs) and fasting are known to increase the expression of enzymes involved in fatty acid oxidation (FAO). However, it has been reported that the ability of physiological stressors to induce enzymes of FAO in skeletal muscle is blunted with obesity. In this regard, we sought to explore the effects and potential mechanisms of an HFD on the expression of FAO enzymes in the fed and fasted state. The consumption of an HFD increased the mRNA expression or protein content of medium-chain acyl-CoA dehydrogenase (MCAD), uncoupling protein-3 (UCP3), and pyruvate dehydrogenase kinase 4 (PDK4) in the fed state. Fasting increased the mRNA expression of PDK4, MCAD, and UCP-3, and the protein content of UCP-3 in chow but not HFD rats. HFDs did not increase carnitine palmitoyl transfer-1 (CPT-1) mRNA levels in the fed state and the effects of fasting were markedly reduced compared with chow-fed rats. The expression of peroxisome-proliferator-activated receptor-γ coactivator-1β (PGC-1β) was increased in muscle from HFD rats in the fed state, while PGC-1-related coactivator (PRC) was increased with fasting in chow-fed but not HFD rats. Plasma fatty acid levels were elevated in the fed state from HFD rats but not increased further with fasting, whereas fasting increased plasma fatty acids in chow-fed animals. Fasting-mediated increases in plasma epinephrine, and the activation of PKA and AMPK in skeletal muscle were similar between chow and HFD rats. p38 MAPK phosphorylation was increased with fasting in chow-fed but not HFD rats. Our findings suggest that a blunted effect of fasting on the induction of PDK4, MCAD, and UCP3 in skeletal muscle from HFD rats is likely a result of already elevated levels of these enzymes, the induction of which is associated with increases in plasma fatty acid and PGC-1β. On the other hand, a blunted induction of PRC and CPT-1 mRNA may be explained by decreases in p38 MAPK signaling.
Collapse
Affiliation(s)
- Bruce C. Frier
- Alberta Diabetes Institute, University of Alberta, Edmonton, Alberta, Canada
| | - René L. Jacobs
- Group on the Molecular and Cellular Biology of Lipids and Department of Agricultural, Food and Nutritional Science, University of Alberta, Edmonton, Alberta, Canada; and
| | - David C. Wright
- Alberta Diabetes Institute, University of Alberta, Edmonton, Alberta, Canada
- Department of Human Health and Nutritional Sciences, University of Guelph, Guelph, Ontario, Canada
| |
Collapse
|