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Li TL, Zhu NN, Yin Z, Sun J, Guo JP, Yuan HT, Shi XM, Guo HY, Li SX, Shan ZL. Transcriptomic analysis of epicardial adipose tissue reveals the potential crosstalk genes and immune relationship between type 2 diabetes mellitus and atrial fibrillation. Gene 2024; 920:148528. [PMID: 38703871 DOI: 10.1016/j.gene.2024.148528] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/02/2023] [Revised: 03/27/2024] [Accepted: 05/01/2024] [Indexed: 05/06/2024]
Abstract
BACKGROUND The complex relationship between atrial fibrillation (AF) and type 2 diabetes mellitus (T2DM) suggests a potential role for epicardial adipose tissue (EAT) that requires further investigation. This study employs bioinformatics and experimental approaches to clarify EAT's role in linking T2DM and AF, aiming to unravel the biological mechanisms involved. METHOD Bioinformatics analysis initially identified common differentially expressed genes (DEGs) in EAT from T2DM and AF datasets. Pathway enrichment and network analyses were then performed to determine the biological significance and network connections of these DEGs. Hub genes were identified through six CytoHubba algorithms and subsequently validated biologically, with further in-depth analyses confirming their roles and interactions. Experimentally, db/db mice were utilized to establish a T2DM model. AF induction was executed via programmed transesophageal electrical stimulation and burst pacing, focusing on comparing the incidence and duration of AF. Frozen sections and Hematoxylin and Eosin (H&E) staining illuminated the structures of the heart and EAT. Moreover, quantitative PCR (qPCR) measured the expression of hub genes. RESULTS The study identified 106 DEGs in EAT from T2DM and AF datasets, underscoring significant pathways in energy metabolism and immune regulation. Three hub genes, CEBPZ, PAK1IP1, and BCCIP, emerged as pivotal in this context. In db/db mice, a marked predisposition towards AF induction and extended duration was observed, with HE staining verifying the presence of EAT. Additionally, qPCR validated significant changes in hub genes expression in db/db mice EAT. In-depth analysis identified 299 miRNAs and 33 TFs as potential regulators, notably GRHL1 and MYC. GeneMANIA analysis highlighted the hub genes' critical roles in stress responses and leukocyte differentiation, while immune profile correlations highlighted their impact on mast cells and neutrophils, emphasizing the genes' significant influence on immune regulation within the context of T2DM and AF. CONCLUSION This investigation reveals the molecular links between T2DM and AF with a focus on EAT. Targeting these pathways, especially EAT-related ones, may enable personalized treatments and improved outcomes.
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Affiliation(s)
- Tian-Lun Li
- Postgraduate School, Medical School of Chinese PLA, Beijing, China; Department of Cardiology, The Sixth Medical Center, Chinese PLA General Hospital, Beijing, China
| | - Na-Na Zhu
- Postgraduate School, Medical School of Chinese PLA, Beijing, China; Department of Cardiology, The Sixth Medical Center, Chinese PLA General Hospital, Beijing, China
| | - Zhao Yin
- Postgraduate School, Medical School of Chinese PLA, Beijing, China; Department of Cardiology, The Sixth Medical Center, Chinese PLA General Hospital, Beijing, China
| | - Jiao Sun
- Postgraduate School, Medical School of Chinese PLA, Beijing, China; Department of Cardiology, The Sixth Medical Center, Chinese PLA General Hospital, Beijing, China
| | - Jian-Pin Guo
- Department of Cardiology, The Sixth Medical Center, Chinese PLA General Hospital, Beijing, China
| | - Hong-Tao Yuan
- Department of Cardiology, The Sixth Medical Center, Chinese PLA General Hospital, Beijing, China
| | - Xiang-Min Shi
- Department of Cardiology, The Sixth Medical Center, Chinese PLA General Hospital, Beijing, China
| | - Hong-Yang Guo
- Department of Cardiology, The Sixth Medical Center, Chinese PLA General Hospital, Beijing, China
| | - Shi-Xing Li
- Department of Cardiology, The Sixth Medical Center, Chinese PLA General Hospital, Beijing, China
| | - Zhao-Liang Shan
- Postgraduate School, Medical School of Chinese PLA, Beijing, China; Department of Cardiology, The Sixth Medical Center, Chinese PLA General Hospital, Beijing, China.
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Almeida EA, Mehndiratta M, Madhu SV, Kar R, Puri D. PINK1 and oxidative stress in lean and obese patients with type 2 diabetes mellitus. J Diabetes Complications 2023; 37:108542. [PMID: 37354803 DOI: 10.1016/j.jdiacomp.2023.108542] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/09/2023] [Revised: 05/06/2023] [Accepted: 06/10/2023] [Indexed: 06/26/2023]
Abstract
AIM To compare mRNA [messenger RNA] expression of PINK1 in whole blood and the levels of biomarkers of Oxidative Stress (mitochondrial DNA [mtDNA] content & Total Antioxidant status [TAS]) in newly diagnosed lean and obese patients with T2DM. METHODS Newly diagnosed patients of T2DM were enrolled in this study. The patients were divided into two groups of 30 patients each, lean (BMI < 18.5 kg/m2) and obese (BMI > 25 kg/m2). mRNA expression of PINK1 & mtDNA content was measured by real time PCR. Serum TAS was measured using a commercially available kit. RESULTS There was a 1.78-fold decrease in mRNA expression of PINK1 in obese group compared to the lean group. Mean mtDNA content was 300.82 ± 169.66 in the obese group and 332.78 ± 147.07 in the lean group (p = 0.06). Mean levels of TAS was 5.39 ± 2.28 μM Trolox Equivalents in the obese group and 3.85 ± 3.33 μM Trolox Equivalents in the lean group (p = 0.001). CONCLUSION The T2DM patient with obesity had greater OS than the lean patients. Thus, there is a compensatory increase in antioxidants in obese patients with T2DM. Our findings also suggest that decreased levels of PINK1 in obese group are unable to protect the mitochondria against OS leading to decreased mtDNA content. Does it also result in beta cell dysfunction or contribute to insulin resistance in obese patients with T2DM needs to be explored.
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Affiliation(s)
- Edelbert Anthonio Almeida
- MD (Biochemistry), Senior Resident, Department of Biochemistry, University College of Medical Sciences & GTB Hospital, University of Delhi, Delhi, India
| | - Mohit Mehndiratta
- MD (Biochemistry), Professor, Department of Biochemistry, University College of Medical Sciences & GTB Hospital, University of Delhi, Delhi, India.
| | - S V Madhu
- DM (Endocrinology), Professor, Department of Endocrinology, University College of Medical Sciences & GTB Hospital, University of Delhi, Delhi, India
| | - Rajarshi Kar
- MD (Biochemistry), Professor, Department of Biochemistry, University College of Medical Sciences & GTB Hospital, University of Delhi, Delhi, India
| | - Dinesh Puri
- MD (Biochemistry), Director Professor and Head, Department of Biochemistry, University College of Medical Sciences & GTB Hospital, University of Delhi, Delhi, India
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Kitamura N, Zhang S, Morel JD, Nagano U, Taworntawat T, Hosoda S, Nakamura A, Ogawa Y, Benegiamo G, Auwerx J, Tsubota K, Yokoyama Y, Watanabe M. Sodium ferrous citrate and 5-aminolevulinic acid improve type 2 diabetes by maintaining muscle and mitochondrial health. Obesity (Silver Spring) 2023; 31:1038-1049. [PMID: 36823345 DOI: 10.1002/oby.23705] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/09/2022] [Revised: 12/09/2022] [Accepted: 12/14/2022] [Indexed: 02/25/2023]
Abstract
OBJECTIVE Improving mitochondrial function is a promising strategy for intervention in type 2 diabetes mellitus. This study investigated the preventive effects of sodium ferrous citrate (SFC) and 5-aminolevulinic acid phosphate (ALA) on several metabolic dysfunctions associated with obesity because they have been shown to alleviate abnormal glucose metabolism in humans. METHODS Six-week-old male C57BL/6J mice were fed with a normal diet, a high-fat diet, or a high-fat diet supplemented with SFC and ALA for 15 weeks. RESULTS The simultaneous supplementation of SFC + ALA to high-fat diet-fed mice prevented loss of muscle mass, improved muscle strength, and reduced obesity and insulin resistance. SFC + ALA prevented abnormalities in mitochondrial morphology and reverted the diet effect on the skeletal muscle transcriptome, including the expression of glucose uptake and mitochondrial oxidative phosphorylation-related genes. In addition, SFC + ALA prevented the decline in mitochondrial DNA copy number by enhancing mitochondrial DNA maintenance and antioxidant transcription activity, both of which are impaired in high-fat diet-fed mice during long-term fasting. CONCLUSIONS These findings suggest that SFC + ALA supplementation exerts its preventive effects in type 2 diabetes mellitus via improved skeletal muscle and mitochondrial health, further validating its application as a promising strategy for the prevention of obesity-induced metabolic disorders.
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Affiliation(s)
- Naho Kitamura
- Systems Biology Program, Graduate School of Media and Governance, Keio University, Kanagawa, Japan
- Health Science Laboratory, Keio Research Institute at SFC, Kanagawa, Japan
| | - Shiyang Zhang
- Systems Biology Program, Graduate School of Media and Governance, Keio University, Kanagawa, Japan
- Health Science Laboratory, Keio Research Institute at SFC, Kanagawa, Japan
| | - Jean-David Morel
- Laboratory of Integrative and Systems Physiology, École Polytechnique Fédérale de Lausanne (EPFL), Lausanne, Switzerland
| | - Utana Nagano
- Systems Biology Program, Graduate School of Media and Governance, Keio University, Kanagawa, Japan
- Health Science Laboratory, Keio Research Institute at SFC, Kanagawa, Japan
| | - Tanon Taworntawat
- Systems Biology Program, Graduate School of Media and Governance, Keio University, Kanagawa, Japan
- Health Science Laboratory, Keio Research Institute at SFC, Kanagawa, Japan
| | - Shotaro Hosoda
- Systems Biology Program, Graduate School of Media and Governance, Keio University, Kanagawa, Japan
- Health Science Laboratory, Keio Research Institute at SFC, Kanagawa, Japan
| | - Anna Nakamura
- Systems Biology Program, Graduate School of Media and Governance, Keio University, Kanagawa, Japan
- Health Science Laboratory, Keio Research Institute at SFC, Kanagawa, Japan
| | - Yoko Ogawa
- Department of Ophthalmology, Keio University School of Medicine, Tokyo, Japan
| | - Giorgia Benegiamo
- Laboratory of Integrative and Systems Physiology, École Polytechnique Fédérale de Lausanne (EPFL), Lausanne, Switzerland
| | - Johan Auwerx
- Laboratory of Integrative and Systems Physiology, École Polytechnique Fédérale de Lausanne (EPFL), Lausanne, Switzerland
| | - Kazuo Tsubota
- Health Science Laboratory, Keio Research Institute at SFC, Kanagawa, Japan
- Tsubota Laboratory, Inc., Tokyo, Japan
| | - Yoko Yokoyama
- Systems Biology Program, Graduate School of Media and Governance, Keio University, Kanagawa, Japan
- Health Science Laboratory, Keio Research Institute at SFC, Kanagawa, Japan
| | - Mitsuhiro Watanabe
- Systems Biology Program, Graduate School of Media and Governance, Keio University, Kanagawa, Japan
- Health Science Laboratory, Keio Research Institute at SFC, Kanagawa, Japan
- Department of Environment and Information Studies, Keio University, Kanagawa, Japan
- Department of Internal Medicine, Keio University School of Medicine, Tokyo, Japan
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Mohan R, Jo S, Lockridge A, Ferrington DA, Murray K, Eschenlauer A, Bernal-Mizrachi E, Fujitani Y, Alejandro EU. OGT Regulates Mitochondrial Biogenesis and Function via Diabetes Susceptibility Gene Pdx1. Diabetes 2021; 70:2608-2625. [PMID: 34462257 PMCID: PMC8564412 DOI: 10.2337/db21-0468] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/27/2021] [Accepted: 08/19/2021] [Indexed: 12/26/2022]
Abstract
O-GlcNAc transferase (OGT), a nutrient sensor sensitive to glucose flux, is highly expressed in the pancreas. However, the role of OGT in the mitochondria of β-cells is unexplored. In this study, we identified the role of OGT in mitochondrial function in β-cells. Constitutive deletion of OGT (βOGTKO) or inducible ablation in mature β-cells (iβOGTKO) causes distinct effects on mitochondrial morphology and function. Islets from βOGTKO, but not iβOGTKO, mice display swollen mitochondria, reduced glucose-stimulated oxygen consumption rate, ATP production, and glycolysis. Alleviating endoplasmic reticulum stress by genetic deletion of Chop did not rescue the mitochondrial dysfunction in βOGTKO mice. We identified altered islet proteome between βOGTKO and iβOGTKO mice. Pancreatic and duodenal homeobox 1 (Pdx1) was reduced in in βOGTKO islets. Pdx1 overexpression increased insulin content and improved mitochondrial morphology and function in βOGTKO islets. These data underscore the essential role of OGT in regulating β-cell mitochondrial morphology and bioenergetics. In conclusion, OGT couples nutrient signal and mitochondrial function to promote normal β-cell physiology.
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Affiliation(s)
- Ramkumar Mohan
- Department of Integrative Biology and Physiology, University of Minnesota Medical School, Minneapolis, MN
| | - Seokwon Jo
- Department of Integrative Biology and Physiology, University of Minnesota Medical School, Minneapolis, MN
| | - Amber Lockridge
- Department of Integrative Biology and Physiology, University of Minnesota Medical School, Minneapolis, MN
| | - Deborah A Ferrington
- Department of Ophthalmology and Visual Neurosciences, University of Minnesota Medical School, Minneapolis, MN
| | - Kevin Murray
- University of Minnesota Informatics Institute, University of Minnesota Medical School, Minneapolis, MN
| | - Arthur Eschenlauer
- University of Minnesota Informatics Institute, University of Minnesota Medical School, Minneapolis, MN
| | - Ernesto Bernal-Mizrachi
- Miami VA Healthcare System, Miami, FL
- Division of Endocrinology, Diabetes and Metabolism, University of Miami, Miami, FL
| | - Yoshio Fujitani
- Institute for Molecular and Cellular Regulation, Gunma University, Gunma, Japan
| | - Emilyn U Alejandro
- Department of Integrative Biology and Physiology, University of Minnesota Medical School, Minneapolis, MN
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5
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Gupta P, Sharma G, Lahiri A, Barthwal MK. FOXO3a acetylation regulates PINK1, mitophagy, inflammasome activation in murine palmitate-conditioned and diabetic macrophages. J Leukoc Biol 2021; 111:611-627. [PMID: 34288093 DOI: 10.1002/jlb.3a0620-348rr] [Citation(s) in RCA: 16] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022] Open
Abstract
Nucleotide-binding oligomerization domain, leucine-rich repeat, and pyrin domain containing 3 inflammasome and mitophagy play an important role in cytokine release and diabetes progression; however, the role of saturated fatty acid that is induced under such conditions remains little explored. Therefore, the present study evaluates mechanisms regulating mitophagy and inflammasome activation in primary murine diabetic and palmitate-conditioned wild-type (WT) peritoneal macrophages. Peritoneal macrophage, from the diabetic mice and WT mice, challenged with LPS/ATP and palmitate/LPS/ATP, respectively, showed dysfunctional mitochondria as assessed by their membrane potential, mitochondrial reactive oxygen species (mtROS) production, and mitochondrial DNA (mtDNA) release. A defective mitophagy was observed in the diabetic and palmitate-conditioned macrophages stimulated with LPS/ATP as assessed by translocation of PTEN-induced kinase 1 (PINK1)/Parkin or p62 in the mitochondrial fraction. Consequently, increased apoptosis-associated speck-like protein containing a caspase recruitment domain (ASC) oligomerization, caspase-1 activation, and IL1β secretion were observed in LPS/ATP stimulated diabetic and palmitate-conditioned macrophages. LPS/ATP induced Forkhead box O3a (FOXO3a) binding to PINK1 promoter and increased PINK1 mRNA expression in WT macrophages. However, PINK1 mRNA and protein expression were significantly decreased in diabetic and palmitate-conditioned macrophages in response to LPS/ATP. Palmitate-induced acetyl CoA promoted FOXO3a acetylation, which prevented LPS/ATP-induced FOXO3a binding to the PINK1 promoter. C646 (P300 inhibitor) and SRT1720 (SIRT1 activator) prevented FOXO3a acetylation and restored FOXO3a binding to the PINK1 promoter, PINK1 mRNA expression, and mitophagy in palmitate-conditioned macrophages treated with LPS/ATP. Also, a significant decrease in the LPS/ATP-induced mtROS production, mtDNA release, ASC oligomerization, caspase-1 activation, and IL-1β release was observed in the palmitate-conditioned macrophages. Similarly, modulation of FOXO3a acetylation also prevented LPS/ATP-induced mtDNA release and inflammasome activation in diabetic macrophages. Therefore, FOXO3a acetylation regulates PINK1-dependent mitophagy and inflammasome activation in the palmitate-conditioned and diabetic macrophages.
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Affiliation(s)
- Priya Gupta
- Department of Pharmacology, Council of Scientific and Industrial Research-Central Drug Research Institute (CSIR-CDRI), Lucknow, India
| | - Gaurav Sharma
- Department of Pharmacology, Council of Scientific and Industrial Research-Central Drug Research Institute (CSIR-CDRI), Lucknow, India
| | - Amit Lahiri
- Department of Pharmacology, Council of Scientific and Industrial Research-Central Drug Research Institute (CSIR-CDRI), Lucknow, India
| | - Manoj Kumar Barthwal
- Department of Pharmacology, Council of Scientific and Industrial Research-Central Drug Research Institute (CSIR-CDRI), Lucknow, India
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6
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Wang B, Lv X, Wang Y, Wang Z, Liu Q, Lu B, Liu Y, Gu F. CRISPR/Cas9-mediated mutagenesis at microhomologous regions of human mitochondrial genome. SCIENCE CHINA-LIFE SCIENCES 2021; 64:1463-1472. [PMID: 33420919 DOI: 10.1007/s11427-020-1819-8] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/17/2020] [Accepted: 09/04/2020] [Indexed: 12/21/2022]
Abstract
Genetic manipulation of mitochondrial DNA (mtDNA) could be harnessed for deciphering the gene function of mitochondria; it also acts as a promising approach for the therapeutic correction of pathogenic mutation in mtDNA. However, there is still a lack of direct evidence showing the edited mutagenesis within human mtDNA by clustered regularly interspaced short palindromic repeats-associated protein 9 (CRISPR/Cas9). Here, using engineered CRISPR/Cas9, we observed numerous insertion/deletion (InDel) events at several mtDNA microhomologous regions, which were triggered specifically by double-strand break (DSB) lesions within mtDNA. InDel mutagenesis was significantly improved by sgRNA multiplexing and a DSB repair inhibitor, iniparib, demonstrating the evidence of rewiring DSB repair status to manipulate mtDNA using CRISPR/Cas9. These findings would provide novel insights into mtDNA mutagenesis and mitochondrial gene therapy for diseases involving pathogenic mtDNA.
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Affiliation(s)
- Bang Wang
- School of Ophthalmology and Optometry, Eye Hospital, State Key Laboratory of Ophthalmology, Optometry and Vision Science, Ministry of Health and Zhejiang Provincial Key Laboratory of Ophthalmology and Optometry, Wenzhou Medical University, Wenzhou, 325027, China
| | - Xiujuan Lv
- School of Ophthalmology and Optometry, Eye Hospital, State Key Laboratory of Ophthalmology, Optometry and Vision Science, Ministry of Health and Zhejiang Provincial Key Laboratory of Ophthalmology and Optometry, Wenzhou Medical University, Wenzhou, 325027, China
| | - Yufei Wang
- School of Ophthalmology and Optometry, Eye Hospital, State Key Laboratory of Ophthalmology, Optometry and Vision Science, Ministry of Health and Zhejiang Provincial Key Laboratory of Ophthalmology and Optometry, Wenzhou Medical University, Wenzhou, 325027, China
| | - Zhibo Wang
- School of Ophthalmology and Optometry, Eye Hospital, State Key Laboratory of Ophthalmology, Optometry and Vision Science, Ministry of Health and Zhejiang Provincial Key Laboratory of Ophthalmology and Optometry, Wenzhou Medical University, Wenzhou, 325027, China
| | - Qi Liu
- Department of Endocrinology & Metabolism, Shanghai Tenth People's Hospital, Tongji University, Shanghai, 200092, China
| | - Bin Lu
- Attardi Institute of Mitochondrial Biomedicine, School of Laboratory Medicine and Life Sciences, Wenzhou Medical University, Wenzhou, 325035, China
| | - Yong Liu
- School of Ophthalmology and Optometry, Eye Hospital, State Key Laboratory of Ophthalmology, Optometry and Vision Science, Ministry of Health and Zhejiang Provincial Key Laboratory of Ophthalmology and Optometry, Wenzhou Medical University, Wenzhou, 325027, China
| | - Feng Gu
- School of Ophthalmology and Optometry, Eye Hospital, State Key Laboratory of Ophthalmology, Optometry and Vision Science, Ministry of Health and Zhejiang Provincial Key Laboratory of Ophthalmology and Optometry, Wenzhou Medical University, Wenzhou, 325027, China.
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7
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Moore TM, Zhou Z, Strumwasser AR, Cohn W, Lin AJ, Cory K, Whitney K, Ho T, Ho T, Lee JL, Rucker DH, Hoang AN, Widjaja K, Abrishami AD, Charugundla S, Stiles L, Whitelegge JP, Turcotte LP, Wanagat J, Hevener AL. Age-induced mitochondrial DNA point mutations are inadequate to alter metabolic homeostasis in response to nutrient challenge. Aging Cell 2020; 19:e13166. [PMID: 33049094 PMCID: PMC7681042 DOI: 10.1111/acel.13166] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/05/2019] [Revised: 04/10/2020] [Accepted: 04/27/2020] [Indexed: 12/14/2022] Open
Abstract
Mitochondrial dysfunction is frequently associated with impairment in metabolic homeostasis and insulin action, and is thought to underlie cellular aging. However, it is unclear whether mitochondrial dysfunction is a cause or consequence of insulin resistance in humans. To determine the impact of intrinsic mitochondrial dysfunction on metabolism and insulin action, we performed comprehensive metabolic phenotyping of the polymerase gamma (PolG) D257A “mutator” mouse, a model known to accumulate supraphysiological mitochondrial DNA (mtDNA) point mutations. We utilized the heterozygous PolG mutator mouse (PolG+/mut) because it accumulates mtDNA point mutations ~ 500‐fold > wild‐type mice (WT), but fails to develop an overt progeria phenotype, unlike PolGmut/mut animals. To determine whether mtDNA point mutations induce metabolic dysfunction, we examined male PolG+/mut mice at 6 and 12 months of age during normal chow feeding, after 24‐hr starvation, and following high‐fat diet (HFD) feeding. No marked differences were observed in glucose homeostasis, adiposity, protein/gene markers of metabolism, or oxygen consumption in muscle between WT and PolG+/mut mice during any of the conditions or ages studied. However, proteomic analyses performed on isolated mitochondria from 12‐month‐old PolG+/mut mouse muscle revealed alterations in the expression of mitochondrial ribosomal proteins, electron transport chain components, and oxidative stress‐related factors compared with WT. These findings suggest that mtDNA point mutations at levels observed in mammalian aging are insufficient to disrupt metabolic homeostasis and insulin action in male mice.
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Affiliation(s)
- Timothy M. Moore
- Department of Biological Sciences Dana & David Dornsife College of Letters, Arts, and Sciences University of Southern California Los Angeles CA USA
- Division of Endocrinology, Diabetes, and Hypertension Department of Medicine David Geffen School of Medicine University of California Los Angeles CA USA
| | - Zhenqi Zhou
- Division of Endocrinology, Diabetes, and Hypertension Department of Medicine David Geffen School of Medicine University of California Los Angeles CA USA
| | - Alexander R. Strumwasser
- Division of Endocrinology, Diabetes, and Hypertension Department of Medicine David Geffen School of Medicine University of California Los Angeles CA USA
| | - Whitaker Cohn
- Department of Psychiatry and Biobehavioral Sciences & The Semel Institute for Neuroscience and Human Behavior University of California Los Angeles CA USA
| | - Amanda J. Lin
- Division of Endocrinology, Diabetes, and Hypertension Department of Medicine David Geffen School of Medicine University of California Los Angeles CA USA
| | - Kevin Cory
- Division of Endocrinology, Diabetes, and Hypertension Department of Medicine David Geffen School of Medicine University of California Los Angeles CA USA
| | - Kate Whitney
- Division of Endocrinology, Diabetes, and Hypertension Department of Medicine David Geffen School of Medicine University of California Los Angeles CA USA
| | - Theodore Ho
- Division of Endocrinology, Diabetes, and Hypertension Department of Medicine David Geffen School of Medicine University of California Los Angeles CA USA
| | - Timothy Ho
- Division of Endocrinology, Diabetes, and Hypertension Department of Medicine David Geffen School of Medicine University of California Los Angeles CA USA
| | - Joseph L. Lee
- Division of Endocrinology, Diabetes, and Hypertension Department of Medicine David Geffen School of Medicine University of California Los Angeles CA USA
| | - Daniel H. Rucker
- Division of Endocrinology, Diabetes, and Hypertension Department of Medicine David Geffen School of Medicine University of California Los Angeles CA USA
| | - Austin N. Hoang
- Division of Endocrinology, Diabetes, and Hypertension Department of Medicine David Geffen School of Medicine University of California Los Angeles CA USA
| | - Kevin Widjaja
- Division of Endocrinology, Diabetes, and Hypertension Department of Medicine David Geffen School of Medicine University of California Los Angeles CA USA
| | - Aaron D. Abrishami
- Division of Cardiology Department of Medicine David Geffen School of Medicine University of California Los Angeles CA USA
| | - Sarada Charugundla
- Division of Cardiology Department of Medicine David Geffen School of Medicine University of California Los Angeles CA USA
| | - Linsey Stiles
- Division of Endocrinology, Diabetes, and Hypertension Department of Medicine David Geffen School of Medicine University of California Los Angeles CA USA
| | - Julian P. Whitelegge
- Department of Psychiatry and Biobehavioral Sciences & The Semel Institute for Neuroscience and Human Behavior University of California Los Angeles CA USA
| | - Lorraine P. Turcotte
- Department of Biological Sciences Dana & David Dornsife College of Letters, Arts, and Sciences University of Southern California Los Angeles CA USA
| | - Jonathan Wanagat
- Division of Endocrinology, Diabetes, and Hypertension Department of Medicine David Geffen School of Medicine University of California Los Angeles CA USA
| | - Andrea L. Hevener
- Division of Endocrinology, Diabetes, and Hypertension Department of Medicine David Geffen School of Medicine University of California Los Angeles CA USA
- Iris Cantor‐UCLA Women's Health Center University of California Los Angeles CA USA
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8
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Montgomery MK. Mitochondrial Dysfunction and Diabetes: Is Mitochondrial Transfer a Friend or Foe? BIOLOGY 2019; 8:E33. [PMID: 31083560 PMCID: PMC6627584 DOI: 10.3390/biology8020033] [Citation(s) in RCA: 27] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 11/09/2018] [Revised: 11/21/2018] [Accepted: 12/20/2018] [Indexed: 01/01/2023]
Abstract
Obesity, insulin resistance and type 2 diabetes are accompanied by a variety of systemic and tissue-specific metabolic defects, including inflammation, oxidative and endoplasmic reticulum stress, lipotoxicity, and mitochondrial dysfunction. Over the past 30 years, association studies and genetic manipulations, as well as lifestyle and pharmacological invention studies, have reported contrasting findings on the presence or physiological importance of mitochondrial dysfunction in the context of obesity and insulin resistance. It is still unclear if targeting mitochondrial function is a feasible therapeutic approach for the treatment of insulin resistance and glucose homeostasis. Interestingly, recent studies suggest that intact mitochondria, mitochondrial DNA, or other mitochondrial factors (proteins, lipids, miRNA) are found in the circulation, and that metabolic tissues secrete exosomes containing mitochondrial cargo. While this phenomenon has been investigated primarily in the context of cancer and a variety of inflammatory states, little is known about the importance of exosomal mitochondrial transfer in obesity and diabetes. We will discuss recent evidence suggesting that (1) tissues with mitochondrial dysfunction shed their mitochondria within exosomes, and that these exosomes impair the recipient's cell metabolic status, and that on the other hand, (2) physiologically healthy tissues can shed mitochondria to improve the metabolic status of recipient cells. In this context the determination of whether mitochondrial transfer in obesity and diabetes is a friend or foe requires further studies.
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Affiliation(s)
- Magdalene K Montgomery
- Department of Physiology, School of Biomedical Sciences, University of Melbourne, Melbourne 3010, Australia.
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9
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Buj R, Aird KM. Deoxyribonucleotide Triphosphate Metabolism in Cancer and Metabolic Disease. Front Endocrinol (Lausanne) 2018; 9:177. [PMID: 29720963 PMCID: PMC5915462 DOI: 10.3389/fendo.2018.00177] [Citation(s) in RCA: 42] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/09/2018] [Accepted: 04/03/2018] [Indexed: 12/22/2022] Open
Abstract
The maintenance of a healthy deoxyribonucleotide triphosphate (dNTP) pool is critical for the proper replication and repair of both nuclear and mitochondrial DNA. Temporal, spatial, and ratio imbalances of the four dNTPs have been shown to have a mutagenic and cytotoxic effect. It is, therefore, essential for cell homeostasis to maintain the balance between the processes of dNTP biosynthesis and degradation. Multiple oncogenic signaling pathways, such as c-Myc, p53, and mTORC1 feed into dNTP metabolism, and there is a clear role for dNTP imbalances in cancer initiation and progression. Additionally, multiple chemotherapeutics target these pathways to inhibit nucleotide synthesis. Less is understood about the role for dNTP levels in metabolic disorders and syndromes and whether alterations in dNTP levels change cancer incidence in these patients. For instance, while deficiencies in some metabolic pathways known to play a role in nucleotide synthesis are pro-tumorigenic (e.g., p53 mutations), others confer an advantage against the onset of cancer (G6PD). More recent evidence indicates that there are changes in nucleotide metabolism in diabetes, obesity, and insulin resistance; however, whether these changes play a mechanistic role is unclear. In this review, we will address the complex network of metabolic pathways, whereby cells can fuel dNTP biosynthesis and catabolism in cancer, and we will discuss the potential role for this pathway in metabolic disease.
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Affiliation(s)
| | - Katherine M. Aird
- Department of Cellular and Molecular Physiology, Penn State College of Medicine, Hershey, PA, United States
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10
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Alexandar SP, Dhinakaran I, Ravi V, Parthasarathy N, Ganesan S, Bhaskaran M, Arun Kumar GP. Meta-Analysis of Association of Mitochondrial DNA Mutations with Type 2 Diabetes and Gestational Diabetes Mellitus. INT J HUM GENET 2018. [DOI: 10.1080/09723757.2018.1430110] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
Affiliation(s)
- Soundarya Priya Alexandar
- Human Genomics Laboratory, School of Chemical & Biotechnology, SASTRA University Thanjavur, Thanjavur 613 401, Tamil Nadu, India
| | - Indhumathi Dhinakaran
- Human Genomics Laboratory, School of Chemical & Biotechnology, SASTRA University Thanjavur, Thanjavur 613 401, Tamil Nadu, India
| | - Vidhya Ravi
- K.A.P. Viswanatham Govt. Medical College, Trichy, 620 001, Tamil Nadu, India
| | - Nandhini Parthasarathy
- Human Genomics Laboratory, School of Chemical & Biotechnology, SASTRA University Thanjavur, Thanjavur 613 401, Tamil Nadu, India
| | - Somasundari Ganesan
- Human Genomics Laboratory, School of Chemical & Biotechnology, SASTRA University Thanjavur, Thanjavur 613 401, Tamil Nadu, India
| | - Muthumeenakshi Bhaskaran
- Human Genomics Laboratory, School of Chemical & Biotechnology, SASTRA University Thanjavur, Thanjavur 613 401, Tamil Nadu, India
| | - Ganesh Prasad Arun Kumar
- Human Genomics Laboratory, School of Chemical & Biotechnology, SASTRA University Thanjavur, Thanjavur 613 401, Tamil Nadu, India
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Lee SR, Han J. Mitochondrial Mutations in Cardiac Disorders. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2017; 982:81-111. [PMID: 28551783 DOI: 10.1007/978-3-319-55330-6_5] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
Mitochondria individually encapsulate their own genome, unlike other cellular organelles. Mitochondrial DNA (mtDNA) is a circular, double-stranded, 16,569-base paired DNA containing 37 genes: 13 proteins of the mitochondrial respiratory chain, two ribosomal RNAs (rRNAs; 12S and 16S), and 22 transfer RNAs (tRNAs). The mtDNA is more vulnerable to oxidative modifications compared to nuclear DNA because of its proximity to ROS-producing sites, limited presence of DNA damage repair systems, and continuous replication in the cell. mtDNA mutations can be inherited or sporadic. Simple mtDNA mutations are point mutations, which are frequently found in mitochondrial tRNA loci, causing mischarging of mitochondrial tRNAs or deletion, duplication, or reduction in mtDNA content. Because mtDNA has multiple copies and a specific replication mechanism in cells or tissues, it can be heterogenous, resulting in characteristic phenotypic presentations such as heteroplasmy, genetic drift, and threshold effects. Recent studies have increased the understanding of basic mitochondrial genetics, providing an insight into the correlations between mitochondrial mutations and cardiac manifestations including hypertrophic or dilated cardiomyopathy, arrhythmia, autonomic nervous system dysfunction, heart failure, or sudden cardiac death with a syndromic or non-syndromic phenotype. Clinical manifestations of mitochondrial mutations, which result from structural defects, functional impairment, or both, are increasingly detected but are not clear because of the complex interplay between the mitochondrial and nuclear genomes, even in homoplasmic mitochondrial populations. Additionally, various factors such as individual susceptibility, nutritional state, and exposure to chemicals can influence phenotypic presentation, even for the same mtDNA mutation.In this chapter, we summarize our current understanding of mtDNA mutations and their role in cardiac involvement. In addition, epigenetic modifications of mtDNA are briefly discussed for future elucidation of their critical role in cardiac involvement. Finally, current strategies for dealing with mitochondrial mutations in cardiac disorders are briefly stated.
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Affiliation(s)
- Sung Ryul Lee
- Department of Integrated Biomedical Science, Cardiovascular and Metabolic Disease Center, College of Medicine, Inje University, Busan, 47392, South Korea
| | - Jin Han
- National Research Laboratory for Mitochondrial Signaling, Cardiovascular and Metabolic Disease Center, Department of Physiology, College of Medicine, Inje University, Busan, 47392, South Korea.
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