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Sun JL, Cho W, Oh H, Abd El-Aty AM, Hong SA, Jeong JH, Jung TW. Interleukin-38 alleviates hepatic steatosis through AMPK/autophagy-mediated suppression of endoplasmic reticulum stress in obesity models. J Cell Physiol 2024; 239:e31184. [PMID: 38197464 DOI: 10.1002/jcp.31184] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/14/2023] [Revised: 12/05/2023] [Accepted: 12/12/2023] [Indexed: 01/11/2024]
Abstract
Interleukin-38 (IL-38), recently recognized as a cytokine with anti-inflammatory properties that mitigate type 2 diabetes, has been associated with indicators of insulin resistance and nonalcoholic fatty liver disease (NAFLD). This study investigated the impact of IL-38 on hepatic lipid metabolism and endoplasmic reticulum (ER) stress. We assessed protein expression levels using Western blot analysis, while monodansylcadaverine staining was employed to detect autophagosomes in hepatocytes. Oil red O staining was utilized to examine lipid deposition. The study revealed elevated serum IL-38 levels in high-fat diet (HFD)-fed mice and IL-38 secretion from mouse keratinocytes. IL-38 treatment attenuated lipogenic lipid accumulation and ER stress markers in hepatocytes exposed to palmitate. Furthermore, IL-38 treatment increased AMP-activated protein kinase (AMPK) phosphorylation and autophagy. The effects of IL-38 on lipogenic lipid deposition and ER stress were nullified in cultured hepatocytes by suppressing AMPK through small interfering (si) RNA or 3-methyladenine (3MA). In animal studies, IL-38 administration mitigated hepatic steatosis by suppressing the expression of lipogenic proteins and ER stress markers while reversing AMPK phosphorylation and autophagy markers in the livers of HFD-fed mice. Additionally, AMPK siRNA, but not 3MA, mitigated IL-38-enhanced fatty acid oxidation in hepatocytes. In summary, IL-38 alleviates hepatic steatosis through AMPK/autophagy signaling-dependent attenuation of ER stress and enhancement of fatty acid oxidation via the AMPK pathway, suggesting a therapeutic strategy for treating NAFLD.
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Affiliation(s)
- Jaw Long Sun
- Department of Pharmacology, Chung-Ang University, Seoul, Republic of Korea
| | - Wonjun Cho
- Department of Pharmacology, Chung-Ang University, Seoul, Republic of Korea
| | - Heeseung Oh
- Department of Pharmacology, Chung-Ang University, Seoul, Republic of Korea
| | - A M Abd El-Aty
- Department of Pharmacology, Faculty of Veterinary Medicine, Cairo University, Giza, Egypt
- Department of Medical Pharmacology, Medical Faculty, Ataturk University, Erzurum, Turkey
| | - Soon Auck Hong
- Department of Pathology, College of Medicine, Chung-Ang University, Seoul, Republic of Korea
| | - Ji Hoon Jeong
- Department of Pharmacology, Chung-Ang University, Seoul, Republic of Korea
- Department of Global Innovative Drugs, Graduate School of Chung-Ang University, Seoul, Republic of Korea
| | - Tae Woo Jung
- Department of Pharmacology, Chung-Ang University, Seoul, Republic of Korea
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2
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Su R, Wang B, Zhang M, Luo Y, Wang D, Zhao L, Su L, Duan Y, Faucitano L, Jin Y. Effects of energy supplements on the differentiation of skeletal muscle satellite cells. Food Sci Nutr 2021; 9:357-366. [PMID: 33473298 PMCID: PMC7802567 DOI: 10.1002/fsn3.2001] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/16/2020] [Revised: 10/19/2020] [Accepted: 10/25/2020] [Indexed: 01/14/2023] Open
Abstract
To investigate the effects of the activator of AMPK and high glucose on the differentiation of mouse SMSCs, primary SMSCs were isolated from mouse extensor digitorum longus muscle and grown to near confluence (80%). Postconfluent cells were cultured in a growth medium with different inductors: AICAR, glucose, and AICAR mixed with glucose. The specific protein expressions of SMSCs, myoblasts, adipocytes, and brown adipocytes were analyzed on days 0, 3, 5, 7, and 10. The results showed treatment with AICAR in SMSCs markedly activated AMPK phosphorylation (p < .05) and increased protein expression of Pax7 and MyoD (p < .05), high concentrations of intracellular glucose upregulated UCP-1 protein expression and enhanced lipid accumulation (p < .05), the cowork of AICAR and glucose affected a decrease on MyoD, PPARg, and UCP-1 expression (p < .05) and an increase on Pax7. The present study indicated that the certain energy supplements influence the direction of SMSC differentiation which may contribution on the structure of muscle and meat quality, sequentially.
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Affiliation(s)
- Rina Su
- College of Food Science and EngineeringInner Mongolia Agriculture UniversityHohhotChina
- Inner Mongolia Vocational college of Chemical EngineeringHohhotChina
| | - Bohui Wang
- College of Food Science and EngineeringInner Mongolia Agriculture UniversityHohhotChina
| | - Min Zhang
- College of Food Science and EngineeringInner Mongolia Agriculture UniversityHohhotChina
| | - Yulong Luo
- College of Food Science and EngineeringInner Mongolia Agriculture UniversityHohhotChina
| | - Debao Wang
- College of Food Science and EngineeringInner Mongolia Agriculture UniversityHohhotChina
| | - Lihua Zhao
- College of Food Science and EngineeringInner Mongolia Agriculture UniversityHohhotChina
| | - Lin Su
- College of Food Science and EngineeringInner Mongolia Agriculture UniversityHohhotChina
| | - Yan Duan
- College of Food Science and EngineeringInner Mongolia Agriculture UniversityHohhotChina
| | - Luigi Faucitano
- Agriculture and Agri‐Food CanadaSherbrooke Research and Development CentreSherbrookeQCCanada
| | - Ye Jin
- College of Food Science and EngineeringInner Mongolia Agriculture UniversityHohhotChina
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3
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Hou Y, Su L, Su R, Luo Y, Wang B, Yao D, Zhao L, Jin Y. Effect of feeding regimen on meat quality, MyHC isoforms, AMPK, and PGC-1α genes expression in the biceps femoris muscle of Mongolia sheep. Food Sci Nutr 2020; 8:2262-2270. [PMID: 32405383 PMCID: PMC7215223 DOI: 10.1002/fsn3.1494] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/22/2019] [Revised: 01/16/2020] [Accepted: 01/22/2020] [Indexed: 12/29/2022] Open
Abstract
The effects of two feeding regimens on meat quality, myosin heavy chain (MyHC) types, and key factors regulating muscle fiber type (AMP-activated protein kinase [AMPK] and peroxisome proliferator-activated receptor-coactivator-1α [PGC-1α]) in the biceps femoris muscle of Mongolia sheep were investigated. A total of 20 Mongolia sheep were weaning for 90 days and divided into two groups (pasture group (P) and confinement group (C)) at 10.36 ± 0.35 kg of weaning weight. After weaning, sheep were pasture fed or confinement fed for 9 months. The results showed that live weights, carcass weight, intramuscular fat (IMF), and Warner-Bratzler shear force (WBSF) in P group were significantly lower (p < .05) than that in C group. Compared with P group, color evaluations with respect to L* and b* values were significantly higher (p < .05) in C group. Expression of the MyHC I gene in the P group was significantly higher, while MyHC IIa and MyHC IIb genes expression was significantly lower (p < .05) than that in C group. Also, AMPK activity and expression of AMPKα2 and PGC-1α genes were significantly higher (p < .05) in P group compared with C group. The present study indicated that muscle fiber composition was one of the key differences leading to the differences of meat quality in different feeding regimens. AMPK, particularly AMPKα2, and PGC-1α were considered to be two key factors regulating muscle fiber types in Mongolia sheep. The results support that AMPK activity and the expression of AMPKα2 and PGC-1α genes may affect the composition of muscle fibers; thus, AMPK activity and the expression of AMPKα2 and PGC-1α genes had an effect on meat quality by changed composition of muscle fibers.
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Affiliation(s)
- Yanru Hou
- College of Food Science and EngineeringInner Mongolia Agricultural UniversityHohhotChina
| | - Lin Su
- College of Food Science and EngineeringInner Mongolia Agricultural UniversityHohhotChina
| | - Rina Su
- College of Food Science and EngineeringInner Mongolia Agricultural UniversityHohhotChina
| | - Yulong Luo
- College of Food Science and EngineeringInner Mongolia Agricultural UniversityHohhotChina
| | - Bohui Wang
- College of Food Science and EngineeringInner Mongolia Agricultural UniversityHohhotChina
| | - Duo Yao
- College of Food Science and EngineeringInner Mongolia Agricultural UniversityHohhotChina
| | - Lihua Zhao
- College of Food Science and EngineeringInner Mongolia Agricultural UniversityHohhotChina
| | - Ye Jin
- College of Food Science and EngineeringInner Mongolia Agricultural UniversityHohhotChina
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Löffler MC, Mayer AE, Trujillo Viera J, Loza Valdes A, El-Merahbi R, Ade CP, Karwen T, Schmitz W, Slotta A, Erk M, Janaki-Raman S, Matesanz N, Torres JL, Marcos M, Sabio G, Eilers M, Schulze A, Sumara G. Protein kinase D1 deletion in adipocytes enhances energy dissipation and protects against adiposity. EMBO J 2018; 37:e99182. [PMID: 30389661 PMCID: PMC6236335 DOI: 10.15252/embj.201899182] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/06/2018] [Revised: 09/21/2018] [Accepted: 09/26/2018] [Indexed: 12/18/2022] Open
Abstract
Nutrient overload in combination with decreased energy dissipation promotes obesity and diabetes. Obesity results in a hormonal imbalance, which among others activates G protein-coupled receptors utilizing diacylglycerol (DAG) as secondary messenger. Protein kinase D1 (PKD1) is a DAG effector, which integrates multiple nutritional and hormonal inputs, but its physiological role in adipocytes is unknown. Here, we show that PKD1 promotes lipogenesis and suppresses mitochondrial fragmentation, biogenesis, respiration, and energy dissipation in an AMP-activated protein kinase (AMPK)-dependent manner. Moreover, mice lacking PKD1 in adipocytes are resistant to diet-induced obesity due to elevated energy expenditure. Beiging of adipocytes promotes energy expenditure and counteracts obesity. Consistently, deletion of PKD1 promotes expression of the β3-adrenergic receptor (ADRB3) in a CCAAT/enhancer binding protein (C/EBP)-α- and δ-dependent manner, which leads to the elevated expression of beige markers in adipocytes and subcutaneous adipose tissue. Finally, deletion of PKD1 in adipocytes improves insulin sensitivity and ameliorates liver steatosis. Thus, depletion of PKD1 in adipocytes increases energy dissipation by several complementary mechanisms and might represent an attractive strategy to treat obesity and its related complications.
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Affiliation(s)
- Mona C Löffler
- Rudolf Virchow Center for Experimental Biomedicine, University of Würzburg, Würzburg, Germany
| | - Alexander E Mayer
- Rudolf Virchow Center for Experimental Biomedicine, University of Würzburg, Würzburg, Germany
| | - Jonathan Trujillo Viera
- Rudolf Virchow Center for Experimental Biomedicine, University of Würzburg, Würzburg, Germany
| | - Angel Loza Valdes
- Rudolf Virchow Center for Experimental Biomedicine, University of Würzburg, Würzburg, Germany
| | - Rabih El-Merahbi
- Rudolf Virchow Center for Experimental Biomedicine, University of Würzburg, Würzburg, Germany
| | - Carsten P Ade
- Biocenter, Theodor Boveri Institute, University of Würzburg, Würzburg, Germany
| | - Till Karwen
- Rudolf Virchow Center for Experimental Biomedicine, University of Würzburg, Würzburg, Germany
| | - Werner Schmitz
- Biocenter, Theodor Boveri Institute, University of Würzburg, Würzburg, Germany
| | - Anja Slotta
- Rudolf Virchow Center for Experimental Biomedicine, University of Würzburg, Würzburg, Germany
| | - Manuela Erk
- Rudolf Virchow Center for Experimental Biomedicine, University of Würzburg, Würzburg, Germany
| | - Sudha Janaki-Raman
- Biocenter, Theodor Boveri Institute, University of Würzburg, Würzburg, Germany
| | - Nuria Matesanz
- Centro Nacional de Investigaciones Cardiovasculares Carlos III (CNIC), Madrid, Spain
| | - Jorge L Torres
- Department of Internal Medicine, University Hospital of Salamanca-IBSAL, Salamanca, Spain
| | - Miguel Marcos
- Department of Internal Medicine, University Hospital of Salamanca-IBSAL, Salamanca, Spain
- Department of Medicine, University of Salamanca, Salamanca, Spain
| | - Guadalupe Sabio
- Centro Nacional de Investigaciones Cardiovasculares Carlos III (CNIC), Madrid, Spain
| | - Martin Eilers
- Biocenter, Theodor Boveri Institute, University of Würzburg, Würzburg, Germany
| | - Almut Schulze
- Biocenter, Theodor Boveri Institute, University of Würzburg, Würzburg, Germany
| | - Grzegorz Sumara
- Rudolf Virchow Center for Experimental Biomedicine, University of Würzburg, Würzburg, Germany
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Alhamami HN, Alshamrani A, Briski KP. Inhibition of glycogen phosphorylase stimulates ventromedial hypothalamic nucleus AMP-activated protein kinase: Activity and neuronal nitric oxide synthase protein expression in male rats. Physiol Rep 2018; 5. [PMID: 29199177 PMCID: PMC5727266 DOI: 10.14814/phy2.13484] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/21/2017] [Revised: 09/28/2017] [Accepted: 10/02/2017] [Indexed: 11/24/2022] Open
Abstract
The glucose polymer glycogen is a vital fuel reserve in the brain. The mediobasal hypothalamic energy sensor AMP‐activated protein kinase (AMPK) maintains glucostasis via neurotransmitter mechanisms that suppress [γ‐aminobutyric acid; GABA] or stimulate [nitric oxide; steroidogenic factor‐1 (SF1)] counter‐regulatory outflow. This study investigated whether glycogen‐derived fuel supply is a critical screened variable in ventromedial hypothalamic nucleus (VMN) monitoring of neuro‐metabolic stability during glucostasis and/or insulin (I)‐induced hypoglycemia. Adult male rats were pretreated by intra‐VMN infusion of the glycogen phosphorylase inhibitor 1,4‐dideoxy‐1,4‐imino‐D‐arabinitol (DAB) before sc vehicle or I injection. Western blot analyses of micropunch‐dissected VMN tissue from euglycemic animals showed DAB augmentation of phosphoAMPK (pAMPK), neuronal nitric oxide synthase (nNOS), and SF‐1, but not glutamate decarboxylase65/67 (GAD) protein. Combinatory DAB/I treatment did not further enhance AMPK activity but significantly amplified nNOS expression relative to DAB alone. Hypoglycemic stimulation of corticosterone, but not glucagon release was prevented by DAB. Results imply that glycogen‐derived substrate fuel provision represses VMN AMPK activity and neurotransmitter signals of metabolic deficiency. Progressive augmentation of nNOS protein by DAB/I versus DAB/V intimates that “fuel‐inhibited” nitrergic neurons may exhibit increasing sensitivity to disrupted glycogen breakdown during glucoprivation versus glucostasis. nNOS and GAD reactivity to DAB/I, but not I implies that acute glycogen utilization during hypoglycemia may be sufficiently robust to avert effects on local metabolic sensory signaling. DAB/I upregulation of GAD alongside prevention of hypercorticosteronemia suggests that indicators of metabolic sufficiency may occur secondary to local compensatory adaptations to severe restriction of glucose‐derived energy.
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Affiliation(s)
- Hussain N Alhamami
- Department of Basic Pharmaceutical Sciences, School of Pharmacy, College of Health and Pharmaceutical Sciences, University of Louisiana at Monroe, Monroe, Louisiana
| | - Ayed Alshamrani
- Department of Basic Pharmaceutical Sciences, School of Pharmacy, College of Health and Pharmaceutical Sciences, University of Louisiana at Monroe, Monroe, Louisiana
| | - Karen P Briski
- Department of Basic Pharmaceutical Sciences, School of Pharmacy, College of Health and Pharmaceutical Sciences, University of Louisiana at Monroe, Monroe, Louisiana
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6
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Guo B, Han X, Tkach D, Huang S, Zhang D. AMPK promotes the survival of colorectal cancer stem cells. Animal Model Exp Med 2018; 1:134-142. [PMID: 30891558 PMCID: PMC6388072 DOI: 10.1002/ame2.12016] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/26/2018] [Accepted: 05/03/2018] [Indexed: 12/21/2022] Open
Abstract
BACKGROUND Colorectal cancer (CRC) is the third most commonly diagnosed cancer in males and the second in females worldwide in 2012. In the past 20 years, strong evidence suggests that cancer stem cells are the main culprit of cancer metastasis, chemotherapy resistance, and relapse. METHODS To further understand the unique biological properties of cancer stem cells and uncover novel molecular targets to eradicate them, we first established a panel of patient-derived xenograft (PDX) tumor models using tumors surgically removed from human colorectal cancer patients. We then isolated CRC cancer stem cells based on their ALDH activity using fluorescent-activated cell sorting (FACS) and characterized their metabolic properties. RESULTS Interestingly, we found that the CRC cancer stem cells (ie, CRC cells with higher ALDH activity, or ALDH+) express higher level of antioxidant genes and have lower level of reactive oxygen species (ROS) than non-CRC cancer stem cells (ie, CRC cells with lower ALDH activity, or ALDH-). The CRC cancer stem cells also possess more mitochondria mass and show higher mitochondrial activity. More intriguingly, we observed higher AMP-activated protein kinase (AMPK) activities in these CRC cancer stem cells. Inhibition of the AMPK activity using 2 AMPK inhibitors, Compound C and Iodotubercidin, preferentially induces cell death in CRC cancer stem cells. CONCLUSION We propose that AMPK inhibitors may help to eradicate the CRC cancer stem cells and prevent the relapse of CRCs.
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Affiliation(s)
- Bing Guo
- Pfizer ResearchPearl RiverNYUSA
- Novartis PharmaceuticalsMorris PlainsNJUSA
| | - Xin Han
- Pfizer ResearchPearl RiverNYUSA
| | | | | | - Dong Zhang
- Pfizer ResearchPearl RiverNYUSA
- Department of Biomedical SciencesCollege of Osteopathic MedicineNew York Institute of TechnologyOld WestburyNYUSA
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Chen M, Liu J, Yang L, Ling W. AMP-activated protein kinase regulates lipid metabolism and the fibrotic phenotype of hepatic stellate cells through inhibition of autophagy. FEBS Open Bio 2017; 7:811-820. [PMID: 28593136 PMCID: PMC5458462 DOI: 10.1002/2211-5463.12221] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/30/2016] [Revised: 03/21/2017] [Accepted: 03/27/2017] [Indexed: 12/20/2022] Open
Abstract
Hepatic stellate cells (HSCs) are the principal hepatic cell type responsible for liver fibrosis. Although AMP-activated protein kinase (AMPK) is known to regulate the activation of HSCs, little is known about its underlying molecular mechanisms. In the present study, we demonstrate that AMPK activation by 5-aminoimidazole-4-carboxamide-1-4-ribofuranoside (AICAR) restricts the fibrotic potential elicited by transforming growth factor β (TGF-β) in LX-2 cells through modulation of autophagy. AICAR treatment activated the mechanistic target of rapamycin/Akt pathway and thus inhibited autophagy flux and lipid droplet degradation in lysosomes induced by TGF-β. Pretreatment with the autophagy inducer rapamycin reversed the effects of AMPK, further confirming that AICAR inhibited TGF-β-induced HSC activation via the regulation of autophagy flux. Our study indicates that AICAR exerts its anti-fibrotic and anti-lipid depletion effect, at least in part, by inhibiting TGF-β-induced autophagy flux.
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Affiliation(s)
- Ming Chen
- Department of Nutrition School of Public Health Sun Yat-Sen University Guangzhou Guangdong China.,Guangdong Provincial Key Laboratory of Food, Nutrition and Health Guangzhou Guangdong China
| | - Jiaxing Liu
- Department of Nutrition School of Public Health Sun Yat-Sen University Guangzhou Guangdong China.,Guangdong Provincial Key Laboratory of Food, Nutrition and Health Guangzhou Guangdong China
| | - Lili Yang
- Department of Nutrition School of Public Health Sun Yat-Sen University Guangzhou Guangdong China.,Guangdong Provincial Key Laboratory of Food, Nutrition and Health Guangzhou Guangdong China
| | - Wenhua Ling
- Department of Nutrition School of Public Health Sun Yat-Sen University Guangzhou Guangdong China.,Guangdong Provincial Key Laboratory of Food, Nutrition and Health Guangzhou Guangdong China
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Chun MJ, Choi H, Jun DW, Kim S, Kim YN, Kim SY, Lee CH. Fanconi anemia protein FANCD2 is activated by AICAR, a modulator of AMPK and cellular energy metabolism. FEBS Open Bio 2017; 7:284-292. [PMID: 28174693 PMCID: PMC5292659 DOI: 10.1002/2211-5463.12185] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/27/2016] [Revised: 12/14/2016] [Accepted: 12/16/2016] [Indexed: 01/09/2023] Open
Abstract
FANCD2 is a pivotal molecule in the pathogenesis of Fanconi anemia (FA), an autosomal recessive human syndrome with diverse clinical phenotypes, including cancer predisposition, short stature, and hematological abnormalities. In our previous study, we detected the functional association of FANC proteins, whose mutations are responsible for the onset of FA, with AMPK in response to DNA interstrand crosslinking lesions. Because AMPK is well known as a critical sensing molecule for cellular energy levels, we checked whether FANCD2 activation occurs after treatments affecting AMPK and/or cellular energy status. Among the treatments tested, AMPK‐activating 5‐aminoimidazole‐4‐carboxamide‐ribonucleoside (AICAR) induced monoubiquitination and nuclear foci formation of FANCD2, which are biomarkers of FANCD2 activation. FANCD2 activation was abolished by treatments with Compound C, an AMPK inhibitor, or after AMPKα1 knockdown, substantiating the involvement of AMPK in AICAR‐induced FANCD2 activation. Similarly, FANCA protein, which is a component of the FA core complex monoubiquitinating FANCD2, was required for this event. Furthermore, FANCD2 repression enhanced cell death upon AICAR treatments in transformed fibroblasts and cell cycle arrest in the renal cell carcinoma cell line Caki‐1. Overall, this study showed FANCD2 involvement in response to AICAR, a chemical modulating cellular energy metabolism.
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Affiliation(s)
- Min Jeong Chun
- Cancer Cell and Molecular Biology Branch Research Institute National Cancer Center Goyang Korea
| | - Hana Choi
- Cancer Cell and Molecular Biology Branch Research Institute National Cancer Center Goyang Korea
| | - Dong Wha Jun
- Precision Medicine Branch Research Institute National Cancer Center Goyang Korea
| | - Sunshin Kim
- Precision Medicine Branch Research Institute National Cancer Center Goyang Korea
| | - Yong-Nyun Kim
- Comparative Biomedicine Research Branch Research Institute National Cancer Center Goyang Korea
| | - Soo-Youl Kim
- Cancer Cell and Molecular Biology Branch Research Institute National Cancer Center Goyang Korea
| | - Chang-Hun Lee
- Cancer Cell and Molecular Biology Branch Research Institute National Cancer Center Goyang Korea
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O'Neill HM, Lally JS, Galic S, Pulinilkunnil T, Ford RJ, Dyck JRB, van Denderen BJ, Kemp BE, Steinberg GR. Skeletal muscle ACC2 S212 phosphorylation is not required for the control of fatty acid oxidation during exercise. Physiol Rep 2015; 3:3/7/e12444. [PMID: 26156967 PMCID: PMC4552526 DOI: 10.14814/phy2.12444] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022] Open
Abstract
During submaximal exercise fatty acids are a predominant energy source for muscle contractions. An important regulator of fatty acid oxidation is acetyl-CoA carboxylase (ACC), which exists as two isoforms (ACC1 and ACC2) with ACC2 predominating in skeletal muscle. Both ACC isoforms regulate malonyl-CoA production, an allosteric inhibitor of carnitine palmitoyltransferase 1 (CPT-1); the primary enzyme controlling fatty acyl-CoA flux into mitochondria for oxidation. AMP-activated protein kinase (AMPK) is a sensor of cellular energy status that is activated during exercise or by pharmacological agents such as metformin and AICAR. In resting muscle the activation of AMPK with AICAR leads to increased phosphorylation of ACC (S79 on ACC1 and S221 on ACC2), which reduces ACC activity and malonyl-CoA; effects associated with increased fatty acid oxidation. However, whether this pathway is vital for regulating skeletal muscle fatty acid oxidation during conditions of increased metabolic flux such as exercise/muscle contractions remains unknown. To examine this we characterized mice lacking AMPK phosphorylation sites on ACC2 (S212 in mice/S221 in humans-ACC2-knock-in [ACC2-KI]) or both ACC1 (S79) and ACC2 (S212) (ACC double knock-in [ACCD-KI]) during submaximal treadmill exercise and/or ex vivo muscle contractions. We find that surprisingly, ACC2-KI mice had normal exercise capacity and whole-body fatty acid oxidation during treadmill running despite elevated muscle ACC2 activity and malonyl-CoA. Similar results were observed in ACCD-KI mice. Fatty acid oxidation was also maintained in muscles from ACC2-KI mice contracted ex vivo. These findings indicate that pathways independent of ACC phosphorylation are important for regulating skeletal muscle fatty acid oxidation during exercise/muscle contractions.
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Affiliation(s)
- Hayley M O'Neill
- Division of Endocrinology and Metabolism, Department of Medicine, McMaster University, Hamilton, Ontario, Canada Department of Medicine, St. Vincent's Institute of Medical Research, University of Melbourne, Fitzroy, Victoria, Australia Faculty of Health Sciences and Medicine, Bond Institute of Health and Sport, Bond University, Robina, Queensland, Australia
| | - James S Lally
- Division of Endocrinology and Metabolism, Department of Medicine, McMaster University, Hamilton, Ontario, Canada
| | - Sandra Galic
- Department of Medicine, St. Vincent's Institute of Medical Research, University of Melbourne, Fitzroy, Victoria, Australia
| | - Thomas Pulinilkunnil
- Department of Pediatrics, Faculty of Medicine and Dentistry, Cardiovascular Research Centre, Mazankowski Alberta Heart Institute, University of Alberta, Edmonton, Alberta, Canada
| | - Rebecca J Ford
- Division of Endocrinology and Metabolism, Department of Medicine, McMaster University, Hamilton, Ontario, Canada
| | - Jason R B Dyck
- Department of Pediatrics, Faculty of Medicine and Dentistry, Cardiovascular Research Centre, Mazankowski Alberta Heart Institute, University of Alberta, Edmonton, Alberta, Canada
| | - Bryce J van Denderen
- Department of Medicine, St. Vincent's Institute of Medical Research, University of Melbourne, Fitzroy, Victoria, Australia
| | - Bruce E Kemp
- Department of Medicine, St. Vincent's Institute of Medical Research, University of Melbourne, Fitzroy, Victoria, Australia
| | - Gregory R Steinberg
- Division of Endocrinology and Metabolism, Department of Medicine, McMaster University, Hamilton, Ontario, Canada Department of Medicine, St. Vincent's Institute of Medical Research, University of Melbourne, Fitzroy, Victoria, Australia
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