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Cai W, Hu J, Zhang Y, Guo Z, Zhou Z, Hou S. Cis-eQTLs in seven duck tissues identify novel candidate genes for growth and carcass traits. BMC Genomics 2024; 25:429. [PMID: 38689208 PMCID: PMC11061949 DOI: 10.1186/s12864-024-10338-7] [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: 10/29/2023] [Accepted: 04/23/2024] [Indexed: 05/02/2024] Open
Abstract
BACKGROUND Expression quantitative trait loci (eQTL) studies aim to understand the influence of genetic variants on gene expression. The colocalization of eQTL mapping and GWAS strategy could help identify essential candidate genes and causal DNA variants vital to complex traits in human and many farm animals. However, eQTL mapping has not been conducted in ducks. It is desirable to know whether eQTLs within GWAS signals contributed to duck economic traits. RESULTS In this study, we conducted an eQTL analysis using publicly available RNA sequencing data from 820 samples, focusing on liver, muscle, blood, adipose, ovary, spleen, and lung tissues. We identified 113,374 cis-eQTLs for 12,266 genes, a substantial fraction 39.1% of which were discovered in at least two tissues. The cis-eQTLs of blood were less conserved across tissues, while cis-eQTLs from any tissue exhibit a strong sharing pattern to liver tissue. Colocalization between cis-eQTLs and genome-wide association studies (GWAS) of 50 traits uncovered new associations between gene expression and potential loci influencing growth and carcass traits. SRSF4, GSS, and IGF2BP1 in liver, NDUFC2 in muscle, ELF3 in adipose, and RUNDC1 in blood could serve as the candidate genes for duck growth and carcass traits. CONCLUSIONS Our findings highlight substantial differences in genetic regulation of gene expression across duck primary tissues, shedding light on potential mechanisms through which candidate genes may impact growth and carcass traits. Furthermore, this availability of eQTL data offers a valuable resource for deciphering further genetic association signals that may arise from ongoing extensive endeavors aimed at enhancing duck production traits.
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Affiliation(s)
- Wentao Cai
- Institute of Animal Science, Chinese Academy of Agricultural Sciences, Beijing, 100193, China
| | - Jian Hu
- Institute of Animal Science, Chinese Academy of Agricultural Sciences, Beijing, 100193, China
| | - Yunsheng Zhang
- Institute of Animal Science, Chinese Academy of Agricultural Sciences, Beijing, 100193, China
| | - Zhanbao Guo
- Institute of Animal Science, Chinese Academy of Agricultural Sciences, Beijing, 100193, China
| | - Zhengkui Zhou
- Institute of Animal Science, Chinese Academy of Agricultural Sciences, Beijing, 100193, China
| | - Shuisheng Hou
- Institute of Animal Science, Chinese Academy of Agricultural Sciences, Beijing, 100193, China.
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Abstract
Diabetes mellitus is the most common endocrine disturbance in inherited mitochondrial diseases. It is essential to increase awareness of the correct diagnosis and treatment of diabetes in these patients and screen for the condition in family members, as diabetes might appear with distinctive clinical features, complications and at different ages of onset. The severity of mitochondrial-related diabetes is likely to manifest on a large scale of phenotypes depending on the location of the mutation and whether the number of affected mitochondria copies (heteroplasmy) reaches a critical threshold. Regarding diabetes treatment, the first-choice treatment for type 2 diabetes (T2D), metformin, is not recommended because of the risk of lactic acidosis. The preferred treatment for diabetes in patients with mitochondrial disorders is SGLT-2i and mitochondrial GLP-1-related substances. The tight relationship between mitochondrial dysfunction, reduced glucose-stimulated insulin secretion (GSIS), and diabetes development in human patients is acknowledged. However, despite the well-characterized role of mitochondria in GSIS, there is a relative lack of data in humans implicating mitochondrial dysfunction as a primary defect in T2D. Our recent studies have provided data supporting the significant role of the mitochondrial respiratory-chain enzyme, cytochrome c oxidase (COX), in regulating GSIS in a rodent model of T2D, the Cohen diabetic sensitive (CDs) rat. The nutritionally induced diabetic CDs rat demonstrates several features of mitochondrial diseases: markedly reduced COX activity in several tissues, increased reactive oxygen production, decreased ATP generation, and increased lactate dehydrogenase expression in islets. Moreover, our data demonstrate that reduced islet-COX activity precedes the onset of diabetes, suggesting that islet-COX deficiency is the primary defect causing diabetes in this model. This review examines the possibility of including T2D as a primary mitochondrial-related disease. Understanding the critical interdependence between diabetes and mitochondrial dysfunction, centering on the role of COX, may open novel avenues to diagnose and treat diabetes in patients with mitochondrial diseases and mitochondrial dysfunction in diabetic patients.
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Aharon-Hananel G, Romero-Afrima L, Saada A, Mantzur C, Raz I, Weksler-Zangen S. Cytochrome c Oxidase Activity as a Metabolic Regulator in Pancreatic Beta-Cells. Cells 2022; 11:cells11060929. [PMID: 35326380 PMCID: PMC8946064 DOI: 10.3390/cells11060929] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/11/2022] [Revised: 03/01/2022] [Accepted: 03/03/2022] [Indexed: 02/06/2023] Open
Abstract
Pancreatic β-cells couple glucose-stimulated insulin secretion (GSIS) with oxidative phosphorylation via cytochrome c oxidase (COX), a mitochondrial respiratory-chain enzyme. The Cohen diabetic-sensitive (CDs) rats exhibit hyperglycemia when fed a diabetogenic diet but maintain normoglycemia on a regular diet. We have previously reported a decreased COX activity in CDs rats and explored its relevance for type 2 diabetes (T2D). In this study, we investigated the relation between COX activity in islets, peripheral-blood mononuclear cells (PBMCs), and GSIS during diabetes development in CDs rats fed a diabetogenic diet for 4, 11, 20, and 30 days and during reversion to normoglycemia in hyperglycemic CDs rats fed a reversion diet for 7, 11, and 20 days. An oral glucose-tolerance test was performed at different periods of the diets measuring blood glucose and insulin concentrations. COX activity was determined in islets and PBMCs isolated from rats at the different periods of the diets. We demonstrated a progressive reduction in COX activity in CDs-islets that correlated positively with the decreasing GSIS (R2 = 0.9691, p < 0.001) and inversely with the elevation in blood glucose levels (R2 = 0.8396, p < 0.001). Hyperglycemia was initiated when islet COX activity decreased below 46%. The reversion diet restored >46% of the islet COX activity and GSIS while re-establishing normoglycemia. Interestingly, COX activity in PBMCs correlated significantly with islet COX activity (R2 = 0.8944, p < 0.001). Our data support islet COX activity as a major metabolic regulator of β-cells function. The correlation between COX activity in PBMCs and islets may serve as a noninvasive biomarker to monitor β-cell dysfunction in diabetes.
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Affiliation(s)
- Genya Aharon-Hananel
- The Hadassah Diabetes Center, Hadassah Medical Center, Jerusalem 9112102, Israel; (G.A.-H.); (L.R.-A.); (C.M.); (I.R.)
- Division of Endocrinology, Diabetes and Metabolism, The Chaim Sheba Medical Center, Tel Hashomer, Ramat-Gan 5266202, Israel
- Sackler School of Medicine, Tel Aviv University, Tel Aviv 6997801, Israel
- The Department of Genetics, Hadassah Medical Center, Jerusalem 9112102, Israel;
| | - Leonor Romero-Afrima
- The Hadassah Diabetes Center, Hadassah Medical Center, Jerusalem 9112102, Israel; (G.A.-H.); (L.R.-A.); (C.M.); (I.R.)
- The Department of Genetics, Hadassah Medical Center, Jerusalem 9112102, Israel;
| | - Ann Saada
- The Department of Genetics, Hadassah Medical Center, Jerusalem 9112102, Israel;
- Faculty of Medicine Hebrew, University of Jerusalem, Jerusalem 9112102, Israel
| | - Carmit Mantzur
- The Hadassah Diabetes Center, Hadassah Medical Center, Jerusalem 9112102, Israel; (G.A.-H.); (L.R.-A.); (C.M.); (I.R.)
| | - Itamar Raz
- The Hadassah Diabetes Center, Hadassah Medical Center, Jerusalem 9112102, Israel; (G.A.-H.); (L.R.-A.); (C.M.); (I.R.)
- Faculty of Medicine Hebrew, University of Jerusalem, Jerusalem 9112102, Israel
| | - Sarah Weksler-Zangen
- The Hadassah Diabetes Center, Hadassah Medical Center, Jerusalem 9112102, Israel; (G.A.-H.); (L.R.-A.); (C.M.); (I.R.)
- Faculty of Medicine Hebrew, University of Jerusalem, Jerusalem 9112102, Israel
- The Liver Research Laboratory, Hadassah Medical Center, Jerusalem 9112102, Israel
- Correspondence: ; Tel.: +972-50-5172008
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Abstract
Cancer is a heterogeneous set of diseases characterized by the rewiring of cellular signaling and the reprogramming of metabolic pathways to sustain growth and proliferation. In past decades, studies were focused primarily on the genetic complexity of cancer. Recently, increasing number of studies have discovered several mutations among metabolic enzymes in different tumor cells. Most of the enzymes are regulated by coenzymes, organic cofactors, that function as intermediate carrier of electrons or functional groups that are transferred during the reaction. However, the precise role of cofactors is not well elucidated. In this review, we discuss several metabolic enzymes associated to cancer metabolism rewiring, whose inhibition may represent a therapeutic target. Such enzymes, upon expression or inhibition, may impact also the coenzymes levels, but only in few cases, it was possible to direct correlate coenzymes changes with a specific enzyme. In addition, we also summarize an up-to-date information on biological role of some coenzymes, preclinical and clinical studies, that have been carried out in various cancers and their outputs.
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Forte M, Palmerio S, Bianchi F, Volpe M, Rubattu S. Mitochondrial complex I deficiency and cardiovascular diseases: current evidence and future directions. J Mol Med (Berl) 2019; 97:579-91. [PMID: 30863992 DOI: 10.1007/s00109-019-01771-3] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/15/2019] [Revised: 02/06/2019] [Accepted: 03/05/2019] [Indexed: 02/06/2023]
Abstract
Compelling evidence demonstrates the emerging role of mitochondrial complex I deficiency in the onset and development of cardiovascular diseases (CVDs). In particular, defects in single subunits of mitochondrial complex I have been associated with cardiac hypertrophy, ischemia/reperfusion injury, as well as diabetic complications and stroke in pre-clinical studies. Moreover, data obtained in humans revealed that genes coding for complex I proteins were associated with different CVDs. In this review, we discuss recent experimental studies that underline the contributory role of mitochondrial complex I deficiency in the etiopathogenesis of several CVDs, with a particular focus on those involving loss of function models of mitochondrial complex I. We also discuss human studies and potential therapeutic strategies able to rescue mitochondrial function in CVDs.
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Fang H, Hu N, Zhao Q, Wang B, Zhou H, Fu Q, Shen L, Chen X, Shen F, Lyu J. mtDNA Haplogroup N9a Increases the Risk of Type 2 Diabetes by Altering Mitochondrial Function and Intracellular Mitochondrial Signals. Diabetes 2018; 67:1441-1453. [PMID: 29735607 DOI: 10.2337/db17-0974] [Citation(s) in RCA: 30] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/14/2017] [Accepted: 04/26/2018] [Indexed: 11/13/2022]
Abstract
Mitochondrial DNA (mtDNA) haplogroups have been associated with the incidence of type 2 diabetes (T2D); however, their underlying role in T2D remains poorly elucidated. Here, we report that mtDNA haplogroup N9a was associated with an increased risk of T2D occurrence in Southern China (odds ratio 1.999 [95% CI 1.229-3.251], P = 0.005). By using transmitochondrial technology, we demonstrated that the activity of respiratory chain complexes was lower in the case of mtDNA haplogroup N9a (N9a1 and N9a10a) than in three non-N9a haplogroups (D4j, G3a2, and Y1) and that this could lead to alterations in mitochondrial function and mitochondrial redox status. Transcriptome analysis revealed that OXPHOS function and metabolic regulation differed markedly between N9a and non-N9a cybrids. Furthermore, in N9a cybrids, insulin-stimulated glucose uptake might be inhibited at least partially through enhanced stimulation of ERK1/2 phosphorylation and subsequent TLR4 activation, which was found to be mediated by the elevated redox status in N9a cybrids. Although it remains unclear whether other signaling pathways (e.g., Wnt pathway) contribute to the T2D susceptibility of haplogroup N9a, our data indicate that in the case of mtDNA haplogroup N9a, T2D is affected, at least partially through ERK1/2 overstimulation and subsequent TLR4 activation.
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Affiliation(s)
- Hezhi Fang
- Key Laboratory of Laboratory Medicine, Ministry of Education, Zhejiang Provincial Key Laboratory of Medical Genetics, College of Laboratory Medicine and Life Sciences, Wenzhou Medical University, Wenzhou, Zhejiang, China
| | - Nianqi Hu
- Key Laboratory of Laboratory Medicine, Ministry of Education, Zhejiang Provincial Key Laboratory of Medical Genetics, College of Laboratory Medicine and Life Sciences, Wenzhou Medical University, Wenzhou, Zhejiang, China
| | - Qiongya Zhao
- Key Laboratory of Laboratory Medicine, Ministry of Education, Zhejiang Provincial Key Laboratory of Medical Genetics, College of Laboratory Medicine and Life Sciences, Wenzhou Medical University, Wenzhou, Zhejiang, China
| | - Bingqian Wang
- Key Laboratory of Laboratory Medicine, Ministry of Education, Zhejiang Provincial Key Laboratory of Medical Genetics, College of Laboratory Medicine and Life Sciences, Wenzhou Medical University, Wenzhou, Zhejiang, China
| | - Huaibin Zhou
- Key Laboratory of Laboratory Medicine, Ministry of Education, Zhejiang Provincial Key Laboratory of Medical Genetics, College of Laboratory Medicine and Life Sciences, Wenzhou Medical University, Wenzhou, Zhejiang, China
| | - Qingzi Fu
- Key Laboratory of Laboratory Medicine, Ministry of Education, Zhejiang Provincial Key Laboratory of Medical Genetics, College of Laboratory Medicine and Life Sciences, Wenzhou Medical University, Wenzhou, Zhejiang, China
| | - Lijun Shen
- Key Laboratory of Laboratory Medicine, Ministry of Education, Zhejiang Provincial Key Laboratory of Medical Genetics, College of Laboratory Medicine and Life Sciences, Wenzhou Medical University, Wenzhou, Zhejiang, China
| | - Xiong Chen
- Department of Endocrinology, The First Affiliated Hospital of Wenzhou Medical University, Wenzhou Medical University, Wenzhou, Zhejiang, China
| | - Feixia Shen
- Department of Endocrinology, The First Affiliated Hospital of Wenzhou Medical University, Wenzhou Medical University, Wenzhou, Zhejiang, China
| | - Jianxin Lyu
- Key Laboratory of Laboratory Medicine, Ministry of Education, Zhejiang Provincial Key Laboratory of Medical Genetics, College of Laboratory Medicine and Life Sciences, Wenzhou Medical University, Wenzhou, Zhejiang, China
- Zhejiang Provincial People's Hospital, Affiliated People's Hospital of Hangzhou Medical College, Hangzhou, Zhejiang, China
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Raffa S, Scrofani C, Valente S, Micaloni A, Forte M, Bianchi F, Coluccia R, Geurts AM, Sciarretta S, Volpe M, Torrisi MR, Rubattu S. In vitro characterization of mitochondrial function and structure in rat and human cells with a deficiency of the NADH: ubiquinone oxidoreductase Ndufc2 subunit. Hum Mol Genet 2018; 26:4541-4555. [PMID: 28973657 PMCID: PMC5886163 DOI: 10.1093/hmg/ddx333] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/26/2017] [Accepted: 08/22/2017] [Indexed: 12/11/2022] Open
Abstract
Ndufc2, a subunit of the NADH: ubiquinone oxidoreductase, plays a key role in the assembly and activity of complex I within the mitochondrial OXPHOS chain. Its deficiency has been shown to be involved in diabetes, cancer and stroke. To improve our knowledge on the mechanisms underlying the increased disease risk due to Ndufc2 reduction, we performed the present in vitro study aimed at the fine characterization of the derangements in mitochondrial structure and function consequent to Ndufc2 deficiency. We found that both fibroblasts obtained from skin of heterozygous Ndufc2 knock-out rat model showed marked mitochondrial dysfunction and PBMC obtained from subjects homozygous for the TT genotype of the rs11237379/NDUFC2 variant, previously shown to associate with reduced gene expression, demonstrated increased generation of reactive oxygen species and mitochondrial damage. The latter was associated with increased oxidative stress and significant ultrastructural impairment of mitochondrial morphology with a loss of internal cristae. In both models the exposure to stress stimuli, such as high-NaCl concentration or LPS, exacerbated the mitochondrial damage and dysfunction. Resveratrol significantly counteracted the ROS generation. These findings provide additional insights on the role of an altered pattern of mitochondrial structure–function as a cause of human diseases. In particular, they contribute to underscore a potential genetic risk factor for cardiovascular diseases, including stroke.
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Affiliation(s)
- Salvatore Raffa
- Department of Clinical and Molecular Medicine, School of Medicine and Psychology, Sapienza University of Rome, Rome, Italy.,Cellular Diagnostics Unit, Azienda Sant'Andrea University Hospital, Rome, Italy
| | - Cristina Scrofani
- Department of Clinical and Molecular Medicine, School of Medicine and Psychology, Sapienza University of Rome, Rome, Italy
| | - Sabatino Valente
- Department of Clinical and Molecular Medicine, School of Medicine and Psychology, Sapienza University of Rome, Rome, Italy
| | - Andrea Micaloni
- Department of Clinical and Molecular Medicine, School of Medicine and Psychology, Sapienza University of Rome, Rome, Italy
| | | | | | | | - Aron M Geurts
- Department of Physiology and Human and Molecular Genetics Center, Medical College of Wisconsin, Milwaukee, WI, USA
| | - Sebastiano Sciarretta
- I.R.C.C.S. Neuromed, Pozzilli (Isernia), Italy.,Department of Medical-Surgical Sciences and Biotechnologies, Sapienza University of Rome, Latina, Italy
| | - Massimo Volpe
- Department of Clinical and Molecular Medicine, School of Medicine and Psychology, Sapienza University of Rome, Rome, Italy.,I.R.C.C.S. Neuromed, Pozzilli (Isernia), Italy
| | - Maria Rosaria Torrisi
- Department of Clinical and Molecular Medicine, School of Medicine and Psychology, Sapienza University of Rome, Rome, Italy.,Cellular Diagnostics Unit, Azienda Sant'Andrea University Hospital, Rome, Italy
| | - Speranza Rubattu
- Department of Clinical and Molecular Medicine, School of Medicine and Psychology, Sapienza University of Rome, Rome, Italy.,I.R.C.C.S. Neuromed, Pozzilli (Isernia), Italy
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Rubattu S, Stanzione R, Volpe M. Mitochondrial Dysfunction Contributes to Hypertensive Target Organ Damage: Lessons from an Animal Model of Human Disease. Oxid Med Cell Longev 2016; 2016:1067801. [PMID: 27594970 DOI: 10.1155/2016/1067801] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 05/24/2016] [Revised: 07/06/2016] [Accepted: 07/13/2016] [Indexed: 12/18/2022]
Abstract
Mechanisms underlying hypertensive target organ damage (TOD) are not completely understood. The pathophysiological role of mitochondrial oxidative stress, resulting from mitochondrial dysfunction, in development of TOD is unclear. The stroke-prone spontaneously hypertensive rat (SHRSP) is a suitable model of human hypertension and of its vascular consequences. Pathogenesis of TOD in SHRSP is multifactorial, being determined by high blood pressure levels, high salt/low potassium diet, and genetic factors. Accumulating evidence points to a key role of mitochondrial dysfunction in increased susceptibility to TOD development of SHRSP. Mitochondrial abnormalities were described in both heart and brain of SHRSP. Pharmacological compounds able to protect mitochondrial function exerted a significant protective effect on TOD development, independently of blood pressure levels. Through our research efforts, we discovered that two genes encoding mitochondrial proteins, one (Ndufc2) involved in OXPHOS complex I assembly and activity and the second one (UCP2) involved in clearance of mitochondrial ROS, are responsible, when dysregulated, for vascular damage in SHRSP. The suitability of SHRSP as a model of human disease represents a promising background for future translation of the experimental findings to human hypertension. Novel therapeutic strategies toward mitochondrial molecular targets may become a valuable tool for prevention and treatment of TOD in human hypertension.
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Sharples AP, Stewart CE, Seaborne RA. Does skeletal muscle have an 'epi'-memory? The role of epigenetics in nutritional programming, metabolic disease, aging and exercise. Aging Cell 2016; 15:603-16. [PMID: 27102569 PMCID: PMC4933662 DOI: 10.1111/acel.12486] [Citation(s) in RCA: 99] [Impact Index Per Article: 12.4] [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] [Accepted: 03/24/2016] [Indexed: 12/17/2022] Open
Abstract
Skeletal muscle mass, quality and adaptability are fundamental in promoting muscle performance, maintaining metabolic function and supporting longevity and healthspan. Skeletal muscle is programmable and can ‘remember’ early‐life metabolic stimuli affecting its function in adult life. In this review, the authors pose the question as to whether skeletal muscle has an ‘epi’‐memory? Following an initial encounter with an environmental stimulus, we discuss the underlying molecular and epigenetic mechanisms enabling skeletal muscle to adapt, should it re‐encounter the stimulus in later life. We also define skeletal muscle memory and outline the scientific literature contributing to this field. Furthermore, we review the evidence for early‐life nutrient stress and low birth weight in animals and human cohort studies, respectively, and discuss the underlying molecular mechanisms culminating in skeletal muscle dysfunction, metabolic disease and loss of skeletal muscle mass across the lifespan. We also summarize and discuss studies that isolate muscle stem cells from different environmental niches in vivo (physically active, diabetic, cachectic, aged) and how they reportedly remember this environment once isolated in vitro. Finally, we will outline the molecular and epigenetic mechanisms underlying skeletal muscle memory and review the epigenetic regulation of exercise‐induced skeletal muscle adaptation, highlighting exercise interventions as suitable models to investigate skeletal muscle memory in humans. We believe that understanding the ‘epi’‐memory of skeletal muscle will enable the next generation of targeted therapies to promote muscle growth and reduce muscle loss to enable healthy aging.
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Affiliation(s)
- Adam P. Sharples
- Stem Cells, Ageing and Molecular Physiology (SCAMP) Research Unit Exercise Metabolism and Adaptation Research Group (EMARG) Research Institute for Sport and Exercise Sciences (RISES) Liverpool John Moores University Liverpool UK
| | - Claire E. Stewart
- Stem Cells, Ageing and Molecular Physiology (SCAMP) Research Unit Exercise Metabolism and Adaptation Research Group (EMARG) Research Institute for Sport and Exercise Sciences (RISES) Liverpool John Moores University Liverpool UK
| | - Robert A. Seaborne
- Stem Cells, Ageing and Molecular Physiology (SCAMP) Research Unit Exercise Metabolism and Adaptation Research Group (EMARG) Research Institute for Sport and Exercise Sciences (RISES) Liverpool John Moores University Liverpool UK
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Sargsyan E, Artemenko K, Manukyan L, Bergquist J, Bergsten P. Oleate protects beta-cells from the toxic effect of palmitate by activating pro-survival pathways of the ER stress response. Biochim Biophys Acta Mol Cell Biol Lipids 2016; 1861:1151-1160. [PMID: 27344025 DOI: 10.1016/j.bbalip.2016.06.012] [Citation(s) in RCA: 26] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/25/2015] [Revised: 06/11/2016] [Accepted: 06/20/2016] [Indexed: 12/20/2022]
Abstract
Long-term exposure of beta cells to saturated fatty acids impairs insulin secretion and increases apoptosis. In contrast, unsaturated fatty acids protect beta-cells from the long-term negative effects of saturated fatty acids. We aimed to identify the mechanisms underlying this protective action of unsaturated fatty acids. To address the aim, insulin-secreting MIN6 cells were exposed to palmitate in the absence or presence of oleate and analyzed by using nano-LC MS/MS based proteomic approach. Important findings were validated by using alternative approaches. Proteomic analysis identified 34 proteins differentially expressed in the presence of palmitate compared to control samples. These proteins play a role in insulin processing, mitochondrial function, metabolism of biomolecules, calcium homeostasis, exocytosis, receptor signaling, ER protein folding, antioxidant activity and anti-apoptotic function. When oleate was also present during culture, expression of 15 proteins was different from the expression in the presence of palmitate alone. Most of the proteins affected by oleate are targets of the ER stress response and play a pro-survival role in beta cells such as protein folding and antioxidative defence. We conclude that restoration of pro-survival pathways of the ER stress response is a major mechanism underlying the protective effect of unsaturated fatty acids in beta-cells treated with saturated fatty acids.
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Affiliation(s)
- Ernest Sargsyan
- Department of Medical Cell Biology, Uppsala University, Box 571, 75123 Uppsala, Sweden.
| | | | - Levon Manukyan
- Department of Medical Cell Biology, Uppsala University, Box 571, 75123 Uppsala, Sweden
| | - Jonas Bergquist
- Department of Chemistry, Uppsala University, Uppsala, Sweden; SciLifeLab, Uppsala University, Uppsala, Sweden
| | - Peter Bergsten
- Department of Medical Cell Biology, Uppsala University, Box 571, 75123 Uppsala, Sweden
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Rubattu S, Di Castro S, Schulz H, Geurts AM, Cotugno M, Bianchi F, Maatz H, Hummel O, Falak S, Stanzione R, Marchitti S, Scarpino S, Giusti B, Kura A, Gensini GF, Peyvandi F, Mannucci PM, Rasura M, Sciarretta S, Dwinell MR, Hubner N, Volpe M. Ndufc2 Gene Inhibition Is Associated With Mitochondrial Dysfunction and Increased Stroke Susceptibility in an Animal Model of Complex Human Disease. J Am Heart Assoc 2016; 5:JAHA.115.002701. [PMID: 26888427 PMCID: PMC4802485 DOI: 10.1161/jaha.115.002701] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Abstract
Background The genetic basis of stroke susceptibility remains to be elucidated. STR1 quantitative trait locus (STR1/QTL) was identified on rat chromosome 1 of stroke‐prone spontaneously hypertensive rat (SHRSP) upon Japanese‐style stroke‐permissive diet (JD), and it contributes to 20% of the stroke phenotype variance. Methods and Results Nine hundred eighty‐six probe sets mapping on STR1 were selected from the Rat RAE230A array and screened through a microarray differential expression analysis in brains of SHRSP and stroke‐resistant SHR (SHRSR) fed with either regular diet or JD. The gene encoding Ndufc2 (NADH dehydrogenase [ubiquinone] 1 subunit), mapping 8 Mb apart from STR1/QTL Lod score peak, was found significantly down‐regulated under JD in SHRSP compared to SHRSR. Ndufc2 disruption altered complex I assembly and activity, reduced mitochondrial membrane potential and ATP levels, and increased reactive oxygen species production and inflammation both in vitro and in vivo. SHRSR carrying heterozygous Ndufc2 deletion showed renal abnormalities and stroke occurrence under JD, similarly to SHRSP. In humans, T allele variant at NDUFC2/rs11237379 was associated with significant reduction in gene expression and with increased occurrence of early‐onset ischemic stroke by recessive mode of transmission (odds ratio [OR], 1.39; CI, 1.07–1.80; P=0.012). Subjects carrying TT/rs11237379 and A allele variant at NDUFC2/rs641836 had further increased risk of stroke (OR=1.56; CI, 1.14–2.13; P=0.006). Conclusions A significant reduction of Ndufc2 expression causes complex I dysfunction and contributes to stroke susceptibility in SHRSP. Moreover, our current evidence may suggest that Ndufc2 can contribute to an increased occurrence of early‐onset ischemic stroke in humans.
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Affiliation(s)
- Speranza Rubattu
- IRCCS Neuromed, Pozzilli (Isernia), Italy Department of Clinical and Molecular Medicine, School of Medicine and Psychology, Sapienza University of Rome, Ospedale S. Andrea, Rome, Italy
| | | | | | - Aron M Geurts
- Department of Physiology and Human and Molecular Genetics Center, Medical College of Wisconsin, Milwaukee, WI
| | | | | | | | | | | | | | | | - Stefania Scarpino
- Department of Cytology and Histology, School of Medicine and Psychology, University Sapienza of Rome, Ospedale S. Andrea, Rome, Itlay
| | - Betti Giusti
- Department of Experimental and Clinical Medicine, University of Florence, Italy Atherothrombotic Disease Center, AOU Careggi, Florence, Italy
| | - Ada Kura
- Department of Experimental and Clinical Medicine, University of Florence, Italy Atherothrombotic Disease Center, AOU Careggi, Florence, Italy
| | - Gian Franco Gensini
- Department of Experimental and Clinical Medicine, University of Florence, Italy Department of Cardiothoracovascular Medicine, AOU Careggi, Florence, Italy Don Carlo Gnocchi Foundation, Florence, Italy
| | - Flora Peyvandi
- IRCCS Ca' Granda Maggiore Policlinico Hospital Foundation, Milan, Italy
| | | | - Maurizia Rasura
- Stroke Unit, School of Medicine and Psychology, Sapienza University of Rome, Ospedale S. Andrea, Rome, Italy
| | - Sebastiano Sciarretta
- IRCCS Neuromed, Pozzilli (Isernia), Italy Department of Medical-Surgical Sciences and Biotechnologies, Sapienza University of Rome, Latina, Italy
| | - Melinda R Dwinell
- Department of Physiology and Human and Molecular Genetics Center, Medical College of Wisconsin, Milwaukee, WI
| | | | - Massimo Volpe
- IRCCS Neuromed, Pozzilli (Isernia), Italy Department of Clinical and Molecular Medicine, School of Medicine and Psychology, Sapienza University of Rome, Ospedale S. Andrea, Rome, Italy
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Abstract
Since the discovery of the existence of superassemblies between mitochondrial respiratory complexes, such superassemblies have been the object of a passionate debate. It is accepted that respiratory supercomplexes are structures that occur in vivo, although which superstructures are naturally occurring and what could be their functional role remain open questions. The main difficulty is to make compatible the existence of superassemblies with the corpus of data that drove the field to abandon the early understanding of the physical arrangement of the mitochondrial respiratory chain as a compact physical entity (the solid model). This review provides a nonexhaustive overview of the evolution of our understanding of the structural organization of the electron transport chain from the original idea of a compact organization to a view of freely moving complexes connected by electron carriers. Today supercomplexes are viewed not as a revival of the old solid model but rather as a refined revision of the fluid model, which incorporates a new layer of structural and functional complexity.
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Affiliation(s)
- José Antonio Enríquez
- Centro Nacional de Investigaciones Cardiovasculares Carlos III (CNIC), 28029 Madrid, Spain;
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13
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Voisin S, Eynon N, Yan X, Bishop DJ. Exercise training and DNA methylation in humans. Acta Physiol (Oxf) 2015; 213:39-59. [PMID: 25345837 DOI: 10.1111/apha.12414] [Citation(s) in RCA: 154] [Impact Index Per Article: 17.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/26/2014] [Revised: 06/14/2014] [Accepted: 10/18/2014] [Indexed: 12/17/2022]
Abstract
The response to exercise training (trainability) has been shown to have a strong heritable component. There is growing evidence suggesting that traits such as trainability do not only depend on the genetic code, but also on epigenetic signals. Epigenetic signals play an important role in the modulation of gene expression, through mechanisms such as DNA methylation and histone modifications. There is an emerging evidence to show that physical activity influences DNA methylation in humans. The present review aims to summarize current knowledge on the link between DNA methylation and physical activity in humans. We have critically reviewed the literature and only papers focused on physical activity and its influence on DNA methylation status were included; a total of 25 papers were selected. We concluded that both acute and chronic exercises significantly impact DNA methylation, in a highly tissue- and gene-specific manner. This review also provides insights into the molecular mechanisms of exercise-induced DNA methylation changes, and recommendations for future research.
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Affiliation(s)
- S. Voisin
- Institute of Sport, Exercise and Active Living (ISEAL); Victoria University; Melbourne Vic. Australia
| | - N. Eynon
- Institute of Sport, Exercise and Active Living (ISEAL); Victoria University; Melbourne Vic. Australia
- Murdoch Childrens Research Institute; Royal Children's Hospital; Melbourne Vic. Australia
| | - X. Yan
- Institute of Sport, Exercise and Active Living (ISEAL); Victoria University; Melbourne Vic. Australia
- Murdoch Childrens Research Institute; Royal Children's Hospital; Melbourne Vic. Australia
| | - D. J. Bishop
- Institute of Sport, Exercise and Active Living (ISEAL); Victoria University; Melbourne Vic. Australia
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14
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Gershoni M, Levin L, Ovadia O, Toiw Y, Shani N, Dadon S, Barzilai N, Bergman A, Atzmon G, Wainstein J, Tsur A, Nijtmans L, Glaser B, Mishmar D. Disrupting mitochondrial-nuclear coevolution affects OXPHOS complex I integrity and impacts human health. Genome Biol Evol 2014; 6:2665-80. [PMID: 25245408 PMCID: PMC4224335 DOI: 10.1093/gbe/evu208] [Citation(s) in RCA: 57] [Impact Index Per Article: 5.7] [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] [Indexed: 02/06/2023] Open
Abstract
The mutation rate of the mitochondrial DNA (mtDNA), which is higher by an order of magnitude as compared with the nuclear genome, enforces tight mitonuclear coevolution to maintain mitochondrial activities. Interruption of such coevolution plays a role in interpopulation hybrid breakdown, speciation events, and disease susceptibility. Previously, we found an elevated amino acid replacement rate and positive selection in the nuclear DNA-encoded oxidative phosphorylation (OXPHOS) complex I subunit NDUFC2, a phenomenon important for the direct interaction of NDUFC2 with the mtDNA-encoded complex I subunit ND4. This finding underlines the importance of mitonuclear coevolution to physical interactions between mtDNA and nuclear DNA-encoded factors. Nevertheless, it remains unclear whether this interaction is important for the stability and activity of complex I. Here, we show that siRNA silencing of NDUFC2 reduced growth of human D-407 retinal pigment epithelial cells, significantly diminished mitochondrial membrane potential, and interfered with complex I integrity. Moreover, site-directed mutagenesis of a positively selected amino acid in NDUFC2 significantly interfered with the interaction of NDUFC2 with its mtDNA-encoded partner ND4. Finally, we show that a genotype combination involving this amino acid (NDUFC2 residue 46) and the mtDNA haplogroup HV likely altered susceptibility to type 2 diabetes mellitus in Ashkenazi Jews. Therefore, mitonuclear coevolution is important for maintaining mitonuclear factor interactions, OXPHOS, and for human health.
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Affiliation(s)
- Moran Gershoni
- Department of Life Sciences, Ben Gurion University of the Negev, Beer Sheva, Israel
| | - Liron Levin
- Department of Life Sciences, Ben Gurion University of the Negev, Beer Sheva, Israel
| | - Ofer Ovadia
- Department of Life Sciences, Ben Gurion University of the Negev, Beer Sheva, Israel
| | - Yasmin Toiw
- Department of Life Sciences, Ben Gurion University of the Negev, Beer Sheva, Israel
| | - Naama Shani
- Department of Life Sciences, Ben Gurion University of the Negev, Beer Sheva, Israel
| | - Sara Dadon
- Department of Life Sciences, Ben Gurion University of the Negev, Beer Sheva, Israel
| | - Nir Barzilai
- Institute of Aging, Division of Endocrinology, Departments of Medicine and Genetics, Albert Einstein College of Medicine, New York, NY, USA
| | - Aviv Bergman
- Department of Systems and Computational Biology, Albert Einstein College of Medicine, New York, NY, USA
| | - Gil Atzmon
- Institute of Aging, Division of Endocrinology, Departments of Medicine and Genetics, Albert Einstein College of Medicine, New York, NY, USA
| | | | - Anat Tsur
- Endocrine Clinic, Clalit Health Services, Jerusalem, Israel
| | - Leo Nijtmans
- Nijmegen Center for Mitochondrial Disorders, Radboud University Medical Centre, Nijmegen, The Netherlands
| | - Benjamin Glaser
- Endocrinology and Metabolism Service, Hadassah-Hebrew University Medical Center, Jerusalem, Israel
| | - Dan Mishmar
- Department of Life Sciences, Ben Gurion University of the Negev, Beer Sheva, Israel
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15
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Weksler-Zangen S, Aharon-Hananel G, Mantzur C, Aouizerat T, Gurgul-Convey E, Raz I, Saada A. IL-1β hampers glucose-stimulated insulin secretion in Cohen diabetic rat islets through mitochondrial cytochrome c oxidase inhibition by nitric oxide. Am J Physiol Endocrinol Metab 2014; 306:E648-57. [PMID: 24425765 DOI: 10.1152/ajpendo.00451.2013] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/16/2023]
Abstract
A high-sucrose, low-copper-diet (HSD) induces inhibition of glucose-sensitive rats (CDs) but not Cohen diabetes-resistant rats (CDr). Copper-supplemented HSD increased activity of the copper-dependent mitochondrial respiratory chain enzyme cytochrome c oxidase (COX) and reversed hyperglycemia. This study examined the mechanism by which interleukin-1β modulates GSIS and the role of COX in this process. We measured COX activity, ATP content, GSIS, iNOS expression, and nitrite production with and without IL-1β, N(ω)-nitro-l-arginine, copper, or potassium cyanide in isolated islets of CDs and CDr fed different diets. We found reduced COX activity, ATP content, and GSIS in isolated islets of CDs rats fed a regular diet. These were severely reduced following HSD and were restored to regular diet levels on copper-supplemented HSD (P < 0.01 vs. CDr islets). Potassium cyanide chemically reduced COX activity, decreasing GSIS and thus reinforcing the link between islet COX activity and GSIS. Interleukin-1β (2.5 U/ml) reduced GSIS and COX activity in CDs islets. Exposure to 10 U/ml interleukin-1β decreased GSIS and COX activity in both CDs and CDr islets, inducing a similar nitrite production. Nevertheless, the effect on GSIS was more marked in CDs islets. A significant iNOS expression was detected in CDs on the HSD diet, which was reduced by copper supplementation. N(ω)-nitro-l-arginine and copper prevented the deleterious effect of interleukin-1β on COX activity and GSIS. We conclude that reduced islet COX activity renders vulnerability to GSIS inhibition on low-copper HSD through two interrelated pathways: 1) by further reducing the activity of COX that is essential for β-cell ATP-production and insulin secretion and 2) by inducing the expression of iNOS and nitric oxide-mediated COX inhibition. We suggest that islet COX activity must be maintained above a critical threshold to sustain adequate GSIS with exposure to low-copper HSD.
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Affiliation(s)
- Sarah Weksler-Zangen
- Diabetes Unit, Department of Internal Medicine, Hadassah-Hebrew University Medical Center, Jerusalem, Israel
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16
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Nitert MD, Dayeh T, Volkov P, Elgzyri T, Hall E, Nilsson E, Yang BT, Lang S, Parikh H, Wessman Y, Weishaupt H, Attema J, Abels M, Wierup N, Almgren P, Jansson PA, Rönn T, Hansson O, Eriksson KF, Groop L, Ling C. Impact of an exercise intervention on DNA methylation in skeletal muscle from first-degree relatives of patients with type 2 diabetes. Diabetes 2012; 61:3322-32. [PMID: 23028138 PMCID: PMC3501844 DOI: 10.2337/db11-1653] [Citation(s) in RCA: 267] [Impact Index Per Article: 22.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/12/2023]
Abstract
To identify epigenetic patterns, which may predispose to type 2 diabetes (T2D) due to a family history (FH) of the disease, we analyzed DNA methylation genome-wide in skeletal muscle from individuals with (FH(+)) or without (FH(-)) an FH of T2D. We found differential DNA methylation of genes in biological pathways including mitogen-activated protein kinase (MAPK), insulin, and calcium signaling (P ≤ 0.007) and of individual genes with known function in muscle, including MAPK1, MYO18B, HOXC6, and the AMP-activated protein kinase subunit PRKAB1 in skeletal muscle of FH(+) compared with FH(-) men. We further validated our findings from FH(+) men in monozygotic twin pairs discordant for T2D, and 40% of 65 analyzed genes exhibited differential DNA methylation in muscle of both FH(+) men and diabetic twins. We further examined if a 6-month exercise intervention modifies the genome-wide DNA methylation pattern in skeletal muscle of the FH(+) and FH(-) individuals. DNA methylation of genes in retinol metabolism and calcium signaling pathways (P < 3 × 10(-6)) and with known functions in muscle and T2D including MEF2A, RUNX1, NDUFC2, and THADA decreased after exercise. Methylation of these human promoter regions suppressed reporter gene expression in vitro. In addition, both expression and methylation of several genes, i.e., ADIPOR1, BDKRB2, and TRIB1, changed after exercise. These findings provide new insights into how genetic background and environment can alter the human epigenome.
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Affiliation(s)
- Marloes Dekker Nitert
- Department of Clinical Sciences, Lund University Diabetes Centre, Lund University, CRC, Scania University Hospital, Malmö, Sweden
| | - Tasnim Dayeh
- Department of Clinical Sciences, Lund University Diabetes Centre, Lund University, CRC, Scania University Hospital, Malmö, Sweden
| | - Peter Volkov
- Department of Clinical Sciences, Lund University Diabetes Centre, Lund University, CRC, Scania University Hospital, Malmö, Sweden
| | - Targ Elgzyri
- Department of Clinical Sciences, Lund University Diabetes Centre, Lund University, CRC, Scania University Hospital, Malmö, Sweden
| | - Elin Hall
- Department of Clinical Sciences, Lund University Diabetes Centre, Lund University, CRC, Scania University Hospital, Malmö, Sweden
| | - Emma Nilsson
- Department of Clinical Sciences, Lund University Diabetes Centre, Lund University, CRC, Scania University Hospital, Malmö, Sweden
| | - Beatrice T. Yang
- Department of Clinical Sciences, Lund University Diabetes Centre, Lund University, CRC, Scania University Hospital, Malmö, Sweden
| | - Stefan Lang
- Department of Clinical Sciences, Lund University Diabetes Centre, Lund University, CRC, Scania University Hospital, Malmö, Sweden
| | - Hemang Parikh
- Laboratory of Translational Genomics, Division of Cancer Epidemiology and Genetics, National Cancer Institute, National Institutes of Health, Bethesda, Maryland
| | - Ylva Wessman
- Department of Clinical Sciences, Lund University Diabetes Centre, Lund University, CRC, Scania University Hospital, Malmö, Sweden
| | - Holger Weishaupt
- Immunology Unit, Institute for Experimental Medical Science, Lund University, Lund, Sweden
| | - Joanne Attema
- Immunology Unit, Institute for Experimental Medical Science, Lund University, Lund, Sweden
| | - Mia Abels
- Department of Clinical Sciences, Lund University Diabetes Centre, Lund University, CRC, Scania University Hospital, Malmö, Sweden
| | - Nils Wierup
- Department of Clinical Sciences, Lund University Diabetes Centre, Lund University, CRC, Scania University Hospital, Malmö, Sweden
| | - Peter Almgren
- Department of Clinical Sciences, Lund University Diabetes Centre, Lund University, CRC, Scania University Hospital, Malmö, Sweden
| | - Per-Anders Jansson
- Wallenberg Laboratory, Sahlgrenska University Hospital, Gothenburg, Sweden
| | - Tina Rönn
- Department of Clinical Sciences, Lund University Diabetes Centre, Lund University, CRC, Scania University Hospital, Malmö, Sweden
| | - Ola Hansson
- Department of Clinical Sciences, Lund University Diabetes Centre, Lund University, CRC, Scania University Hospital, Malmö, Sweden
| | - Karl-Fredrik Eriksson
- Department of Clinical Sciences, Lund University Diabetes Centre, Lund University, CRC, Scania University Hospital, Malmö, Sweden
| | - Leif Groop
- Department of Clinical Sciences, Lund University Diabetes Centre, Lund University, CRC, Scania University Hospital, Malmö, Sweden
| | - Charlotte Ling
- Department of Clinical Sciences, Lund University Diabetes Centre, Lund University, CRC, Scania University Hospital, Malmö, Sweden
- Corresponding author: Charlotte Ling,
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17
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Andersson SA, Olsson AH, Esguerra JLS, Heimann E, Ladenvall C, Edlund A, Salehi A, Taneera J, Degerman E, Groop L, Ling C, Eliasson L. Reduced insulin secretion correlates with decreased expression of exocytotic genes in pancreatic islets from patients with type 2 diabetes. Mol Cell Endocrinol 2012; 364:36-45. [PMID: 22939844 DOI: 10.1016/j.mce.2012.08.009] [Citation(s) in RCA: 95] [Impact Index Per Article: 7.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/14/2011] [Revised: 08/07/2012] [Accepted: 08/13/2012] [Indexed: 02/06/2023]
Abstract
Reduced insulin release has been linked to defect exocytosis in β-cells. However, whether expression of genes suggested to be involved in the exocytotic process (exocytotic genes) is altered in pancreatic islets from patients with type 2 diabetes (T2D), and correlate to insulin secretion, needs to be further investigated. Analysing expression levels of 23 exocytotic genes using microarray revealed reduced expression of five genes in human T2D islets (χ(2)=13.25; p<0.001). Gene expression of STX1A, SYT4, SYT7, SYT11, SYT13, SNAP25 and STXBP1 correlated negatively to in vivo measurements of HbA1c levels and positively to glucose stimulated insulin secretion (GSIS) in vitro in human islets. STX1A, SYT4 and SYT11 protein levels correspondingly decreased in human T2D islets. Moreover, silencing of SYT4 and SYT13 reduced GSIS in INS1-832/13 cells. Our data support that reduced expression of exocytotic genes contributes to impaired insulin secretion, and suggest decreased expression of these genes as part of T2D pathogenesis.
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Affiliation(s)
- Sofia A Andersson
- Islet Cell Exocytosis, Lund University Diabetes Centre, Department of Clinical Sciences Malmö, Lund University, Malmö, Sweden
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18
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Alam MR, Groschner LN, Parichatikanond W, Kuo L, Bondarenko AI, Rost R, Waldeck-Weiermair M, Malli R, Graier WF. Mitochondrial Ca2+ uptake 1 (MICU1) and mitochondrial ca2+ uniporter (MCU) contribute to metabolism-secretion coupling in clonal pancreatic β-cells. J Biol Chem 2012; 287:34445-54. [PMID: 22904319 PMCID: PMC3464549 DOI: 10.1074/jbc.m112.392084] [Citation(s) in RCA: 106] [Impact Index Per Article: 8.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022] Open
Abstract
In pancreatic β-cells, uptake of Ca2+ into mitochondria facilitates metabolism-secretion coupling by activation of various matrix enzymes, thus facilitating ATP generation by oxidative phosphorylation and, in turn, augmenting insulin release. We employed an siRNA-based approach to evaluate the individual contribution of four proteins that were recently described to be engaged in mitochondrial Ca2+ sequestration in clonal INS-1 832/13 pancreatic β-cells: the mitochondrial Ca2+ uptake 1 (MICU1), mitochondrial Ca2+ uniporter (MCU), uncoupling protein 2 (UCP2), and leucine zipper EF-hand-containing transmembrane protein 1 (LETM1). Using a FRET-based genetically encoded Ca2+ sensor targeted to mitochondria, we show that a transient knockdown of MICU1 or MCU diminished mitochondrial Ca2+ uptake upon both intracellular Ca2+ release and Ca2+ entry via L-type channels. In contrast, knockdown of UCP2 and LETM1 exclusively reduced mitochondrial Ca2+ uptake in response to either intracellular Ca2+ release or Ca2+ entry, respectively. Therefore, we further investigated the role of MICU1 and MCU in metabolism-secretion coupling. Diminution of MICU1 or MCU reduced mitochondrial Ca2+ uptake in response to d-glucose, whereas d-glucose-triggered cytosolic Ca2+ oscillations remained unaffected. Moreover, d-glucose-evoked increases in cytosolic ATP and d-glucose-stimulated insulin secretion were diminished in MICU1- or MCU-silenced cells. Our data highlight the crucial role of MICU1 and MCU in mitochondrial Ca2+ uptake in pancreatic β-cells and their involvement in the positive feedback required for sustained insulin secretion.
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Affiliation(s)
- Muhammad Rizwan Alam
- Institute of Molecular Biology and Biochemistry, Center of Molecular Medicine, Medical University of Graz, 8010 Graz, Austria
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Snogdal LS, Wod M, Grarup N, Vestmar M, Sparsø T, Jørgensen T, Lauritzen T, Beck-Nielsen H, Henriksen JE, Pedersen O, Hansen T, Højlund K. Common variation in oxidative phosphorylation genes is not a major cause of insulin resistance or type 2 diabetes. Diabetologia 2012; 55:340-8. [PMID: 22095239 DOI: 10.1007/s00125-011-2377-0] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/09/2011] [Accepted: 10/25/2011] [Indexed: 10/15/2022]
Abstract
AIMS/HYPOTHESIS There is substantial evidence that mitochondrial dysfunction is linked to insulin resistance and is present in several tissues relevant to the pathogenesis of type 2 diabetes. Here, we examined whether common variation in genes involved in oxidative phosphorylation (OxPhos) contributes to type 2 diabetes susceptibility or influences diabetes-related metabolic traits. METHODS OxPhos gene variants (n = 10) that had been nominally associated (p < 0.01) with type 2 diabetes in a recent genome-wide meta-analysis (n = 10,108) were selected for follow-up in 3,599 type 2 diabetic and 4,956 glucose-tolerant Danish individuals. A meta-analysis of these variants was performed in 11,729 type 2 diabetic patients and 43,943 non-diabetic individuals. The impact on OGTT-derived metabolic traits was evaluated in 5,869 treatment-naive individuals from the Danish Inter99 study. RESULTS The minor alleles of COX10 rs9915302 (p = 0.02) and COX5B rs1466100 (p = 0.005) showed nominal association with type 2 diabetes in our Danish cohort. However, in the meta-analysis, none of the investigated variants showed a robust association with type 2 diabetes after correction for multiple testing. Among the alleles potentially associated with type 2 diabetes, none negatively influenced surrogate markers of insulin sensitivity in non-diabetic participants, while the minor alleles of UQCRC1 rs2228561 and COX10 rs10521253 showed a weak (p < 0.01 to p < 0.05) negative influence on indices of glucose-stimulated insulin secretion. CONCLUSIONS/INTERPRETATION We cannot rule out the possibility that common variants in or near OxPhos genes may influence beta cell function in non-diabetic individuals. However, our quantitative trait studies and a sufficiently large meta-analysis indicate that common variation in proximity to the examined OxPhos genes is not a major cause of insulin resistance or type 2 diabetes.
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Affiliation(s)
- L S Snogdal
- Diabetes Research Centre, Department of Endocrinology, Odense University Hospital, Kløvervænget 6, 4th Floor, 5000 Odense, Denmark
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Olsson AH, Yang BT, Hall E, Taneera J, Salehi A, Dekker Nitert M, Ling C. Decreased expression of genes involved in oxidative phosphorylation in human pancreatic islets from patients with type 2 diabetes. Eur J Endocrinol 2011; 165:589-95. [PMID: 21775499 PMCID: PMC3178933 DOI: 10.1530/eje-11-0282] [Citation(s) in RCA: 52] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/09/2023]
Abstract
OBJECTIVE Gene expression alterations, especially in target tissues of insulin, have been associated with type 2 diabetes (T2D). In this study, we examined if genes involved in oxidative phosphorylation (OXPHOS) show differential gene expression and DNA methylation in pancreatic islets from patients with T2D compared with non-diabetic donors. DESIGN AND METHODS Gene expression was analyzed in human pancreatic islets from 55 non-diabetic donors and nine T2D donors using microarray. RESULTS While the expected number of OXPHOS genes with reduced gene expression is 7.21, we identified 21 downregulated OXPHOS genes in pancreatic islets from patients with T2D using microarray analysis. This gives a ratio of observed over expected OXPHOS genes of 26.37 by a χ(2)-test with P=2.81 × 10(-7). The microarray data was validated by qRT-PCR for four selected OXPHOS genes: NDUFA5, NDUFA10, COX11, and ATP6V1H. All four OXPHOS genes were significantly downregulated in islets from patients with T2D compared with non-diabetic donors using qRT-PCR (P ≤ 0.01). Furthermore, HbAlc levels correlated negatively with gene expression of NDUFA5, COX11, and ATP6V1H (P<0.05). Gene expression of NDUFA5, NDUFA10, COX11, and ATP6V1H correlated positively with glucose-stimulated insulin secretion (P<0.03). Finally, DNA methylation was analyzed upstream of the transcription start for NDUFA5, COX11, and ATP6V1H. However, none of the analyzed CpG sites in the three genes showed differences in DNA methylation in islets from donors with T2D compared with non-diabetic donors. CONCLUSION Pancreatic islets from patients with T2D show decreased expression of a set of OXPHOS genes, which may lead to impaired insulin secretion.
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