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Wei X, Yuan Y, Li M, Li Z, Wang X, Cheng H, Liu X, Hao J, Jin T. Nicotine aggravates pancreatic fibrosis in mice with chronic pancreatitis via mitochondrial calcium uniporter. Tob Induc Dis 2024; 22:TID-22-69. [PMID: 38686042 PMCID: PMC11057042 DOI: 10.18332/tid/186587] [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] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/22/2023] [Revised: 03/27/2024] [Accepted: 03/30/2024] [Indexed: 05/02/2024] Open
Abstract
INTRODUCTION This study aimed to investigate the effects of nicotine on the activation of pancreatic stellate cells (PSCs) and pancreatic fibrosis in chronic pancreatitis (CP), along with its underlying molecular mechanisms. METHODS This was an in vivo and in vitro study. In vitro, PSCs were cultured to study the effects of nicotine on their activation and oxidative stress. Transcriptome sequencing was performed to identify potential signaling pathways involved in nicotine action. And the impact of nicotine on mitochondrial Ca2+ levels and Ca2+ transport-related proteins in PSCs was analyzed. The changes in nicotine effects were observed after the knockdown of the mitochondrial calcium uniporter (MCU) in PSCs. In vivo experiments were conducted using a mouse model of CP to assess the effects of nicotine on pancreatic fibrosis and oxidative stress in mice. The alterations in nicotine effects were observed after treatment with the MCU inhibitor Ru360. RESULTS In vitro experiments demonstrated that nicotine promoted PSCs activation, characterized by increased cell proliferation, elevated α-SMA and collagen expression. Nicotine also increased the production of reactive oxygen species (ROS) and cellular malondialdehyde (MDA), exacerbating oxidative stress damage. Transcriptome sequencing revealed that nicotine may exert its effects through the calcium signaling pathway, and it was verified that nicotine elevated mitochondrial Ca2+ levels and upregulated MCU expression. Knockdown of MCU reversed the effects of nicotine on mitochondrial calcium homeostasis, improved mitochondrial oxidative stress damage and structural dysfunction, thereby alleviating the activation of PSCs. In vivo validation experiments showed that nicotine significantly aggravated pancreatic fibrosis in CP mice, promoted PSCs activation, exacerbated pancreatic tissue oxidative stress, and increased MCU expression. However, treatment with Ru360 significantly mitigated these effects. CONCLUSIONS This study confirms that nicotine upregulates the expression of MCU, leading to mitochondrial calcium overload and exacerbating oxidative stress in PSCs, and ultimately promoting PSCs activation and exacerbating pancreatic fibrosis in CP.
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Affiliation(s)
- Xue Wei
- Department of Gastroenterology, Beijing Chaoyang Hospital, Capital Medical University, Beijing, China
| | - Yue Yuan
- Department of Gastroenterology, Beijing Chaoyang Hospital, Capital Medical University, Beijing, China
| | - Miaomiao Li
- Department of Gastroenterology, Beijing Chaoyang Hospital, Capital Medical University, Beijing, China
| | - Zhiren Li
- Department of Gastroenterology, Beijing Chaoyang Hospital, Capital Medical University, Beijing, China
| | - Xinye Wang
- Department of Gastroenterology, Beijing Chaoyang Hospital, Capital Medical University, Beijing, China
| | - Haoxuan Cheng
- Department of Gastroenterology, Beijing Chaoyang Hospital, Capital Medical University, Beijing, China
| | - Xinjuan Liu
- Department of Gastroenterology, Beijing Chaoyang Hospital, Capital Medical University, Beijing, China
| | - Jianyu Hao
- Department of Gastroenterology, Beijing Chaoyang Hospital, Capital Medical University, Beijing, China
| | - Tong Jin
- Department of Gastroenterology, Beijing Chaoyang Hospital, Capital Medical University, Beijing, China
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Sun X, Gao S, Luo S, Chang R, Jia H, Xu Q, Jiang Q, Loor JJ, Xu C. Mitochondrial Calcium Uniporter Regulator 1 (MCUR1) Relieves Mitochondrial Damage Induced by Lipopolysaccharide by Mediating Mitochondrial Ca 2+ Homeostasis in Bovine Mammary Epithelial Cells. J Agric Food Chem 2023; 71:7278-7288. [PMID: 37145034 DOI: 10.1021/acs.jafc.2c07494] [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] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/06/2023]
Abstract
The metabolic stress triggered by negative energy balance after calving induces mitochondrial damage of bovine mammary epithelial cells. Mitochondrial calcium uniporter regulator 1 (MCUR1) is a key protein-coding gene that mediates mitochondrial calcium ion (Ca2+) uptake and plays an important role in mediating homeostasis of mitochondria. The aim of the present study was to elucidate the effects of MCUR1-mediated Ca2+ homeostasis on mitochondria of bovine mammary epithelial cells in response to an inflammatory challenge with lipopolysaccharide (LPS). Exogenous LPS resulted in upregulation of the MCUR1 mRNA and protein abundance, mitochondrial Ca2+ content, and mitochondrial reactive oxygen species (Mito-ROS) content while decreasing mitochondrial membrane potential, causing mitochondrial damage, and increasing the rate of apoptosis. Ryanodine pretreatment attenuated the upregulation of the mitochondrial Ca2+ content and Mito-ROS content induced by LPS. Overexpression of MCUR1 increased the mitochondrial Ca2+ content and Mito-ROS content, while it decreased mitochondrial membrane potential, damaged mitochondria, and induced cell apoptosis. In addition, knockdown of MCUR1 by small interfering RNA attenuated LPS-induced mitochondrial dysfunction by inhibiting mitochondrial Ca2+ uptake. Our results revealed that exogenous LPS induces MCUR1-mediated mitochondrial Ca2+ overload in bovine mammary epithelial cells, which leads to mitochondrial injury. Thus, MCUR1-mediated Ca2+ homeostasis may be a potential therapeutic target against mitochondrial damage induced by metabolic challenges in bovine mammary epithelial cells.
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Affiliation(s)
- Xudong Sun
- Key Laboratory of Bovine Disease Control in Northeast China, Ministry of Agriculture and Rural Affairs, Heilongjiang Provincial Key Laboratory of Prevention and Control of Bovine Diseases, College of Animal Science and Veterinary Medicine, Heilongjiang Bayi Agricultural University, Daqing 163319, China
| | - Shuang Gao
- Key Laboratory of Bovine Disease Control in Northeast China, Ministry of Agriculture and Rural Affairs, Heilongjiang Provincial Key Laboratory of Prevention and Control of Bovine Diseases, College of Animal Science and Veterinary Medicine, Heilongjiang Bayi Agricultural University, Daqing 163319, China
| | - Shengbin Luo
- Key Laboratory of Bovine Disease Control in Northeast China, Ministry of Agriculture and Rural Affairs, Heilongjiang Provincial Key Laboratory of Prevention and Control of Bovine Diseases, College of Animal Science and Veterinary Medicine, Heilongjiang Bayi Agricultural University, Daqing 163319, China
| | - Renxu Chang
- College of Veterinary Medicine, Hunan Agricultural University, Changsha 410128, China
| | - Hongdou Jia
- Key Laboratory of Bovine Disease Control in Northeast China, Ministry of Agriculture and Rural Affairs, Heilongjiang Provincial Key Laboratory of Prevention and Control of Bovine Diseases, College of Animal Science and Veterinary Medicine, Heilongjiang Bayi Agricultural University, Daqing 163319, China
| | - Qiushi Xu
- Key Laboratory of Bovine Disease Control in Northeast China, Ministry of Agriculture and Rural Affairs, Heilongjiang Provincial Key Laboratory of Prevention and Control of Bovine Diseases, College of Animal Science and Veterinary Medicine, Heilongjiang Bayi Agricultural University, Daqing 163319, China
| | - Qianming Jiang
- Mammalian NutriPhysioGenomics, Department of Animal Sciences and Division of Nutritional Sciences, University of Illinois, Urbana, Illinois 61801, United States
| | - Juan J Loor
- Mammalian NutriPhysioGenomics, Department of Animal Sciences and Division of Nutritional Sciences, University of Illinois, Urbana, Illinois 61801, United States
| | - Chuang Xu
- Key Laboratory of Bovine Disease Control in Northeast China, Ministry of Agriculture and Rural Affairs, Heilongjiang Provincial Key Laboratory of Prevention and Control of Bovine Diseases, College of Animal Science and Veterinary Medicine, Heilongjiang Bayi Agricultural University, Daqing 163319, China
- College of Veterinary Medicine, China Agricultural University, Haidian District, Beijing 100193, China
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Arrigo A, Regua AT, Najjar MK, Lo HW. Tumor Suppressor Candidate 2 (TUSC2): Discovery, Functions, and Cancer Therapy. Cancers (Basel) 2023; 15:cancers15092455. [PMID: 37173921 PMCID: PMC10177220 DOI: 10.3390/cancers15092455] [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] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/24/2023] [Revised: 04/20/2023] [Accepted: 04/23/2023] [Indexed: 05/15/2023] Open
Abstract
Tumor Suppressor Candidate 2 (TUSC2) was first discovered as a potential tumor suppressor gene residing in the frequently deleted 3p21.3 chromosomal region. Since its discovery, TUSC2 has been found to play vital roles in normal immune function, and TUSC2 loss is associated with the development of autoimmune diseases as well as impaired responses within the innate immune system. TUSC2 also plays a vital role in regulating normal cellular mitochondrial calcium movement and homeostasis. Moreover, TUSC2 serves as an important factor in premature aging. In addition to TUSC2's normal cellular functions, TUSC2 has been studied as a tumor suppressor gene that is frequently deleted or lost in a multitude of cancers, including glioma, sarcoma, and cancers of the lung, breast, ovaries, and thyroid. TUSC2 is frequently lost in cancer due to somatic deletion within the 3p21.3 region, transcriptional inactivation via TUSC2 promoter methylation, post-transcriptional regulation via microRNAs, and post-translational regulation via polyubiquitination and proteasomal degradation. Additionally, restoration of TUSC2 expression promotes tumor suppression, eventuating in decreased cell proliferation, stemness, and tumor growth, as well as increased apoptosis. Consequently, TUSC2 gene therapy has been tested in patients with non-small cell lung cancer. This review will focus on the current understanding of TUSC2 functions in both normal and cancerous tissues, mechanisms of TUSC2 loss, TUSC2 cancer therapeutics, open questions, and future directions.
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Affiliation(s)
- Austin Arrigo
- Department of Neurosurgery, McGovern Medical School, University of Texas Health Science Center at Houston, Houston, TX 77030, USA
- Graduate School of Arts and Sciences, Wake Forest University, Winston-Salem, NC 27101, USA
| | - Angelina T Regua
- Department of Neurosurgery, McGovern Medical School, University of Texas Health Science Center at Houston, Houston, TX 77030, USA
| | - Mariana K Najjar
- Department of Neurosurgery, McGovern Medical School, University of Texas Health Science Center at Houston, Houston, TX 77030, USA
- Graduate School of Arts and Sciences, Wake Forest University, Winston-Salem, NC 27101, USA
| | - Hui-Wen Lo
- Department of Neurosurgery, McGovern Medical School, University of Texas Health Science Center at Houston, Houston, TX 77030, USA
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Geng J, Khaket TP, Pan J, Li W, Zhang Y, Ping Y, Cobos Sillero MI, Lu B. Deregulation of ER-mitochondria contact formation and mitochondrial calcium homeostasis mediated by VDAC in fragile X syndrome. Dev Cell 2023; 58:597-615.e10. [PMID: 37040696 PMCID: PMC10113018 DOI: 10.1016/j.devcel.2023.03.002] [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: 02/27/2022] [Revised: 07/31/2022] [Accepted: 03/06/2023] [Indexed: 04/13/2023]
Abstract
Loss of fragile X messenger ribonucleoprotein (FMRP) causes fragile X syndrome (FXS), the most prevalent form of inherited intellectual disability. Here, we show that FMRP interacts with the voltage-dependent anion channel (VDAC) to regulate the formation and function of endoplasmic reticulum (ER)-mitochondria contact sites (ERMCSs), structures that are critical for mitochondrial calcium (mito-Ca2+) homeostasis. FMRP-deficient cells feature excessive ERMCS formation and ER-to-mitochondria Ca2+ transfer. Genetic and pharmacological inhibition of VDAC or other ERMCS components restored synaptic structure, function, and plasticity and rescued locomotion and cognitive deficits of the Drosophila dFmr1 mutant. Expressing FMRP C-terminal domain (FMRP-C), which confers FMRP-VDAC interaction, rescued the ERMCS formation and mito-Ca2+ homeostasis defects in FXS patient iPSC-derived neurons and locomotion and cognitive deficits in Fmr1 knockout mice. These results identify altered ERMCS formation and mito-Ca2+ homeostasis as contributors to FXS and offer potential therapeutic targets.
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Affiliation(s)
- Ji Geng
- Department of Pathology, Stanford University School of Medicine, Stanford, CA 94305, USA
| | - Tejinder Pal Khaket
- Department of Pathology, Stanford University School of Medicine, Stanford, CA 94305, USA
| | - Jie Pan
- Department of Pathology, Stanford University School of Medicine, Stanford, CA 94305, USA
| | - Wen Li
- Department of Pathology, Stanford University School of Medicine, Stanford, CA 94305, USA
| | - Yan Zhang
- Bio-X Institutes, Key Laboratory for the Genetics of Developmental and Neuropsychiatric Disorders, Ministry of Education, Shanghai Jiao Tong University, Shanghai 200240, China; Shanghai Key Laboratory of Psychotic Disorders (No. 13dz2260500), Shanghai Mental Health Center, School of Medicine, Shanghai Jiao Tong University, Shanghai 200030, China
| | - Yong Ping
- Bio-X Institutes, Key Laboratory for the Genetics of Developmental and Neuropsychiatric Disorders, Ministry of Education, Shanghai Jiao Tong University, Shanghai 200240, China; Shanghai Key Laboratory of Psychotic Disorders (No. 13dz2260500), Shanghai Mental Health Center, School of Medicine, Shanghai Jiao Tong University, Shanghai 200030, China
| | | | - Bingwei Lu
- Department of Pathology, Stanford University School of Medicine, Stanford, CA 94305, USA.
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Vecellio Reane D, Cerqua C, Sacconi S, Salviati L, Trevisson E, Raffaello A. The Splicing of the Mitochondrial Calcium Uniporter Genuine Activator MICU1 Is Driven by RBFOX2 Splicing Factor during Myogenic Differentiation. Int J Mol Sci 2022; 23:2517. [PMID: 35269658 DOI: 10.3390/ijms23052517] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/24/2022] [Revised: 02/17/2022] [Accepted: 02/22/2022] [Indexed: 02/04/2023] Open
Abstract
Alternative splicing, the process by which exons within a pre-mRNA transcript are differentially joined or skipped, is crucial in skeletal muscle since it is required both during myogenesis and in post-natal life to reprogram the transcripts of contractile proteins, metabolic enzymes, and transcription factors in functionally distinct muscle fiber types. The importance of such events is underlined by the numerosity of pathological conditions caused by alternative splicing aberrations. Importantly, many skeletal muscle Ca2+ homeostasis genes are also regulated by alternative splicing mechanisms, among which is the Mitochondrial Ca2+ Uniporter (MCU) genuine activator MICU1 which regulates MCU opening upon cell stimulation. We have previously shown that murine skeletal muscle MICU1 is subjected to alternative splicing, thereby generating a splice variant-which was named MICU1.1-that confers unique properties to the mitochondrial Ca2+ uptake and ensuring sufficient ATP production for muscle contraction. Here we extended the analysis of MICU1 alternative splicing to human tissues, finding two additional splicing variants that were characterized by their ability to regulate mitochondrial Ca2+ uptake. Furthermore, we found that MICU1 alternative splicing is induced during myogenesis by the splicing factor RBFOX2. These results highlight the complexity of the alternative splicing mechanisms in skeletal muscle and the regulation of mitochondrial Ca2+ among tissues.
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Morris JL, Gillet G, Prudent J, Popgeorgiev N. Bcl-2 Family of Proteins in the Control of Mitochondrial Calcium Signalling: An Old Chap with New Roles. Int J Mol Sci 2021; 22:3730. [PMID: 33918511 DOI: 10.3390/ijms22073730] [Citation(s) in RCA: 32] [Impact Index Per Article: 10.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/08/2021] [Revised: 03/29/2021] [Accepted: 03/31/2021] [Indexed: 12/12/2022] Open
Abstract
Bcl-2 family proteins are considered as one of the major regulators of apoptosis. Indeed, this family is known to control the mitochondrial outer membrane permeabilization (MOMP): a central step in the mitochondrial pathway of apoptosis. However, in recent years Bcl-2 family members began to emerge as a new class of intracellular calcium (Ca2+) regulators. At mitochondria-ER contacts (MERCs) these proteins are able to interact with major Ca2+ transporters, thus controlling mitochondrial Ca2+ homeostasis and downstream Ca2+ signalling pathways. Beyond the regulation of cell survival, this Bcl-2-dependent control over the mitochondrial Ca2+ dynamics has far-reaching consequences on the physiology of the cell. Here, we review how the Bcl-2 family of proteins mechanistically regulate mitochondrial Ca2+ homeostasis and how this regulation orchestrates cell death/survival decisions as well as the non-apoptotic process of cell migration.
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Vecellio Reane D, Vallese F, Checchetto V, Acquasaliente L, Butera G, De Filippis V, Szabò I, Zanotti G, Rizzuto R, Raffaello A. A MICU1 Splice Variant Confers High Sensitivity to the Mitochondrial Ca 2+ Uptake Machinery of Skeletal Muscle. Mol Cell 2016; 64:760-73. [PMID: 27818145 DOI: 10.1016/j.molcel.2016.10.001] [Citation(s) in RCA: 82] [Impact Index Per Article: 10.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/08/2016] [Revised: 09/06/2016] [Accepted: 09/30/2016] [Indexed: 01/28/2023]
Abstract
Skeletal muscle is a dynamic organ, characterized by an incredible ability to rapidly increase its rate of energy consumption to sustain activity. Muscle mitochondria provide most of the ATP required for contraction via oxidative phosphorylation. Here we found that skeletal muscle mitochondria express a unique MCU complex containing an alternative splice isoform of MICU1, MICU1.1, characterized by the addition of a micro-exon that is sufficient to greatly modify the properties of the MCU. Indeed, MICU1.1 binds Ca2+ one order of magnitude more efficiently than MICU1 and, when heterodimerized with MICU2, activates MCU current at lower Ca2+ concentrations than MICU1-MICU2 heterodimers. In skeletal muscle in vivo, MICU1.1 is required for sustained mitochondrial Ca2+ uptake and ATP production. These results highlight a novel mechanism of the molecular plasticity of the MCU Ca2+ uptake machinery that allows skeletal muscle mitochondria to be highly responsive to sarcoplasmic [Ca2+] responses.
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Wang G, Mémin E, Murali I, Gaspers LD. The effect of chronic alcohol consumption on mitochondrial calcium handling in hepatocytes. Biochem J 2016; 473:3903-21. [PMID: 27582500 DOI: 10.1042/BCJ20160255] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/22/2016] [Accepted: 08/31/2016] [Indexed: 01/08/2023]
Abstract
The damage to liver mitochondria is universally observed in both humans and animal models after excessive alcohol consumption. Acute alcohol treatment has been shown to stimulate calcium (Ca2+) release from internal stores in hepatocytes. The resultant increase in cytosolic Ca2+ is expected to be accumulated by neighboring mitochondria, which could potentially lead to mitochondrial Ca2+ overload and injury. Our data indicate that total and free mitochondrial matrix Ca2+ levels are, indeed, elevated in hepatocytes isolated from alcohol-fed rats compared with their pair-fed control littermates. In permeabilized hepatocytes, the rates of mitochondrial Ca2+ uptake were substantially increased after chronic alcohol feeding, whereas those of mitochondrial Ca2+ efflux were decreased. The changes in mitochondrial Ca2+ handling could be explained by an up-regulation of the mitochondrial Ca2+ uniporter and loss of a cyclosporin A-sensitive Ca2+ transport pathway. In intact cells, hormone-induced increases in mitochondrial Ca2+ declined at slower rates leading to more prolonged elevations of matrix Ca2+ in the alcohol-fed group compared with controls. Moreover, treatment with submaximal concentrations of Ca2+-mobilizing hormones markedly increased the levels of mitochondrial reactive oxygen species (ROS) in hepatocytes from alcohol-fed rats, but did not affect ROS levels in controls. The changes in mitochondrial Ca2+ handling are expected to buffer and attenuate cytosolic Ca2+ increases induced by acute alcohol exposure or hormone stimulation. However, these alterations in mitochondrial Ca2+ handling may also lead to Ca2+ overload during cytosolic Ca2+ increases, which may stimulate the production of mitochondrial ROS, and thus contribute to alcohol-induced liver injury.
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