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Zhang B, Han D, Yang L, He Y, Yang S, Wang H, Zhang X, Du Y, Xiong W, Ha H, Shang P. The mitochondrial fusion-associated protein MFN2 can be used as a novel prognostic molecule for clear cell renal cell carcinoma. BMC Cancer 2023; 23:986. [PMID: 37845657 PMCID: PMC10577979 DOI: 10.1186/s12885-023-11419-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/26/2023] [Accepted: 09/19/2023] [Indexed: 10/18/2023] Open
Abstract
BACKGROUND Mitofusin 2 (MFN2) plays an important role in many tumors, but how its role in renal clear cell carcinoma needs further research. METHODS In this study, we analyzed the expression of MFN2 in renal clear cell carcinoma tissues and normal kidney tissues through the Cancer Genome Atlas (TCGA) database and our clinical samples.Enrichment analysis was performed to determine MFN2-related pathways and biological functions. The correlation of MFN2 expression with immune cells was analyzed.The correlation of the expression of methylation and the methylation sites of MFN2 were analyzed by UALCAN and TCGA databases. Univariate / multivariate COX risk regression and Kaplan-Meier methods were used to determine the prognostic value of MFN2.Nomograms were drawn to predict overall survival (OS) at 1,3, and 5 years. We investigated the role of MFN2 in renal cancer cells using CCK 8, clone formation, wound healing assay, and methylase qPCR experiments. RESULTS MFN2 is poorly expressed in renal clear cell carcinoma compared to normal kidney tissue,and is significantly negatively associated with TNM stage, histological grade and pathological stage.MFN2 was directly associated with OS after multivariate Cox regression analysis.MFN2 shows a hypomethylation state and shows a positive correlation with multiple methylation sites.Signaling pathways through functional enrichment to B-cell receptors and oxidative stress-induced senescence.Moreover, the low expression of MFN2 was positively correlated with the degree of immune cell infiltration in a variety of immune cells.In vitro experiments showed that overexpression of MFN2 significantly inhibited the proliferation and migration of renal clear cells and promoted methylation. CONCLUSIONS In conclusion, MFN2 can be used as a novel prognostic marker for renal clear cell carcinoma and requires further investigation of its role in tumor development.
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Affiliation(s)
- Bin Zhang
- Department of Urology, Institute of Urology, Key Laboratory of Urological Diseases in Gansu Province, Gansu Nephro-Urological Clinical Center, Lanzhou University Second Hospital, Lanzhou, 730030, Gansu, China
| | - Dali Han
- Department of Urology, Institute of Urology, Key Laboratory of Urological Diseases in Gansu Province, Gansu Nephro-Urological Clinical Center, Lanzhou University Second Hospital, Lanzhou, 730030, Gansu, China
| | - LiMing Yang
- Department of Skin and Venereal Diseases, Jincheng People's Hospital, Jincheng, 048000, Shanxi, China
| | - Yang He
- Department of Urology, Institute of Urology, Key Laboratory of Urological Diseases in Gansu Province, Gansu Nephro-Urological Clinical Center, Lanzhou University Second Hospital, Lanzhou, 730030, Gansu, China
| | - Shujun Yang
- Department of Urology, Institute of Urology, Key Laboratory of Urological Diseases in Gansu Province, Gansu Nephro-Urological Clinical Center, Lanzhou University Second Hospital, Lanzhou, 730030, Gansu, China
| | - Hongbo Wang
- Department of Urology, Institute of Urology, Key Laboratory of Urological Diseases in Gansu Province, Gansu Nephro-Urological Clinical Center, Lanzhou University Second Hospital, Lanzhou, 730030, Gansu, China
| | - Xingxing Zhang
- Department of Urology, Institute of Urology, Key Laboratory of Urological Diseases in Gansu Province, Gansu Nephro-Urological Clinical Center, Lanzhou University Second Hospital, Lanzhou, 730030, Gansu, China
| | - Yuelin Du
- Department of Urology, Institute of Urology, Key Laboratory of Urological Diseases in Gansu Province, Gansu Nephro-Urological Clinical Center, Lanzhou University Second Hospital, Lanzhou, 730030, Gansu, China
| | - Wei Xiong
- Department of Urology, Institute of Urology, Key Laboratory of Urological Diseases in Gansu Province, Gansu Nephro-Urological Clinical Center, Lanzhou University Second Hospital, Lanzhou, 730030, Gansu, China
| | - Hualan Ha
- Department of Urology, Institute of Urology, Key Laboratory of Urological Diseases in Gansu Province, Gansu Nephro-Urological Clinical Center, Lanzhou University Second Hospital, Lanzhou, 730030, Gansu, China
| | - Panfeng Shang
- Department of Urology, Institute of Urology, Key Laboratory of Urological Diseases in Gansu Province, Gansu Nephro-Urological Clinical Center, Lanzhou University Second Hospital, Lanzhou, 730030, Gansu, China.
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Ahn SY, Song J, Kim YC, Kim MH, Hyun YM. Mitofusin-2 Promotes the Epithelial-Mesenchymal Transition-Induced Cervical Cancer Progression. Immune Netw 2021; 21:e30. [PMID: 34522443 PMCID: PMC8410987 DOI: 10.4110/in.2021.21.e30] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/11/2021] [Revised: 07/14/2021] [Accepted: 07/17/2021] [Indexed: 12/18/2022] Open
Abstract
High expression of mitofusin-2 (MFN2), a mitochondrial fusion protein, has been frequently associated with poor prognosis of patients with cervical cancer. Here, we aimed to identify the function of MFN2 in cervical cancer to understand its influence on disease prognosis. To this end, from cervical adenocarcinoma, we performed an MTT assay and quantitative RT-PCR (qRT-PCR) analysis to assess the effects of MFN2 on the proliferation and of HeLa cells. Then, colony-formation ability and tumorigenesis were evaluated using a tumor xenograft mouse model. The migration ability related to MFN2 was also measured using a wound healing assay. Consequently, epithelial-mesenchymal transition (EMT) of MFN2-knockdowned HeLa cells originating from adenocarcinoma. markers related to MFN2 were assessed by qRT-PCR. Clinical data were analyzed using cBioPortal and The Cancer Genome Atlas. We found that MFN2 knockdown reduced the proliferation, colony formation ability, migration, and in vivo tumorigenesis of HeLa cells. Primarily, migration of MFN2-knockdowned HeLa cells decreased through the suppression of EMT. Thus, we concluded that MFN2 facilitates cancer progression and in vivo tumorigenesis in HeLa cells. These findings suggest that MFN2 could be a novel target to regulate the EMT program and tumorigenic potential in HeLa cells and might serve as a therapeutic target for cervical cancer. Taken together, this study is expected to contribute to the treatment of patients with cervical cancer.
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Affiliation(s)
- Sung Yong Ahn
- Department of Anatomy, Brain Korea 21 Project, Yonsei University College of Medicine, Seoul, Korea
| | - Jiwon Song
- Department of Anatomy, Brain Korea 21 Project, Yonsei University College of Medicine, Seoul, Korea.,Graduate School of Medical Science, Brain Korea 21 Project, Yonsei University College of Medicine, Seoul, Korea
| | - Yu Cheon Kim
- Department of Anatomy, Brain Korea 21 Project, Yonsei University College of Medicine, Seoul, Korea.,Graduate School of Medical Science, Brain Korea 21 Project, Yonsei University College of Medicine, Seoul, Korea
| | - Myoung Hee Kim
- Department of Anatomy, Brain Korea 21 Project, Yonsei University College of Medicine, Seoul, Korea.,Graduate School of Medical Science, Brain Korea 21 Project, Yonsei University College of Medicine, Seoul, Korea
| | - Young-Min Hyun
- Department of Anatomy, Brain Korea 21 Project, Yonsei University College of Medicine, Seoul, Korea.,Graduate School of Medical Science, Brain Korea 21 Project, Yonsei University College of Medicine, Seoul, Korea
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Ramos-Kuri M, Meka SH, Salamanca-Buentello F, Hajjar RJ, Lipskaia L, Chemaly ER. Molecules linked to Ras signaling as therapeutic targets in cardiac pathologies. Biol Res 2021; 54:23. [PMID: 34344467 PMCID: PMC8330049 DOI: 10.1186/s40659-021-00342-6] [Citation(s) in RCA: 15] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/15/2021] [Accepted: 06/26/2021] [Indexed: 12/11/2022] Open
Abstract
Abstract The Ras family of small Guanosine Triphosphate (GTP)-binding proteins (G proteins) represents one of the main components of intracellular signal transduction required for normal cardiac growth, but is also critically involved in the development of cardiac hypertrophy and heart failure. The present review provides an update on the role of the H-, K- and N-Ras genes and their related pathways in cardiac diseases. We focus on cardiac hypertrophy and heart failure, where Ras has been studied the most. We also review other cardiac diseases, like genetic disorders related to Ras. The scope of the review extends from fundamental concepts to therapeutic applications. Although the three Ras genes have a nearly identical primary structure, there are important functional differences between them: H-Ras mainly regulates cardiomyocyte size, whereas K-Ras regulates cardiomyocyte proliferation. N-Ras is the least studied in cardiac cells and is less associated to cardiac defects. Clinically, oncogenic H-Ras causes Costello syndrome and facio-cutaneous-skeletal syndromes with hypertrophic cardiomyopathy and arrhythmias. On the other hand, oncogenic K-Ras and alterations of other genes of the Ras-Mitogen-Activated Protein Kinase (MAPK) pathway, like Raf, cause Noonan syndrome and cardio-facio-cutaneous syndromes characterized by cardiac hypertrophy and septal defects. We further review the modulation by Ras of key signaling pathways in the cardiomyocyte, including: (i) the classical Ras-Raf-MAPK pathway, which leads to a more physiological form of cardiac hypertrophy; as well as other pathways associated with pathological cardiac hypertrophy, like (ii) The SAPK (stress activated protein kinase) pathways p38 and JNK; and (iii) The alternative pathway Raf-Calcineurin-Nuclear Factor of Activated T cells (NFAT). Genetic alterations of Ras isoforms or of genes in the Ras-MAPK pathway result in Ras-opathies, conditions frequently associated with cardiac hypertrophy or septal defects among other cardiac diseases. Several studies underline the potential role of H- and K-Ras as a hinge between physiological and pathological cardiac hypertrophy, and as potential therapeutic targets in cardiac hypertrophy and failure. Graphic abstract ![]()
The Ras (Rat Sarcoma) gene family is a group of small G proteins Ras is regulated by growth factors and neurohormones affecting cardiomyocyte growth and hypertrophy Ras directly affects cardiomyocyte physiological and pathological hypertrophy Genetic alterations of Ras and its pathways result in various cardiac phenotypes Ras and its pathway are differentially regulated in acquired heart disease Ras modulation is a promising therapeutic target in various cardiac conditions.
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Affiliation(s)
- Manuel Ramos-Kuri
- Instituto Nacional de Cancerología, Unidad de Investigación Biomédica en Cáncer, Secretarìa de Salud/Instituto de Investigaciones Biomédicas, Universidad Nacional Autónoma de México, Mexico City, México.,Researcher of the Facultad de Bioética, Cátedra de Infertilidad, Universidad Anáhuac, Mexico City, México.,Centro de Investigación en Bioética y Genética, Querétaro, México
| | - Sri Harika Meka
- Division of Nephrology, Department of Medicine, Jacobs School of Medicine and Biomedical Sciences, State University of New York at Buffalo, Clinical and Translational Research Center, 875 Ellicott Street, Suite 8030B, Buffalo, NY, 14203, USA
| | - Fabio Salamanca-Buentello
- University of Toronto Institute of Medical Science, Medical Sciences Building, 1 King's College Circle, Room 2374, Toronto, ON, M5S 1A8, Canada
| | | | - Larissa Lipskaia
- INSERM U955 and Département de Physiologie, Hôpital Henri Mondor, FHU SENEC, AP-HP, and Université Paris-Est Créteil (UPEC), 94010, Créteil, France
| | - Elie R Chemaly
- Division of Nephrology, Department of Medicine, Jacobs School of Medicine and Biomedical Sciences, State University of New York at Buffalo, Clinical and Translational Research Center, 875 Ellicott Street, Suite 8030B, Buffalo, NY, 14203, USA.
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Li J, Xu MX, Dai Z, Xu T. Mitofusion 2 Overexpression Decreased Proliferation of Human Embryonic Lung Fibroblasts in Acute Respiratory Distress Syndrome through Inhibiting RAS-RAF-1-ERK1/2 Pathway. Curr Med Sci 2021; 40:1092-1098. [PMID: 33428137 DOI: 10.1007/s11596-020-2305-y] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/06/2020] [Accepted: 09/08/2020] [Indexed: 11/28/2022]
Abstract
Acute respiratory distress syndrome (ARDS) is one of the most fatal diseases worldwide. Pulmonary fibrosis occurs early in ARDS, and its severity plays a crucial role in ARDS mortality rate. Some studies suggested that fibroproliferation is an essential mechanism in ARDS. Mitofusion2 (Mfn2) overexpression plays a role in inhibiting cell proliferation. However, the role and potential mechanism of Mfn2 on the proliferation of fibroblasts is still unknown. In this study, we aimed at exploring the effect of Mfn2 on the human embryonic lung fibroblasts (HELF) and discussed its related mechanism. The HELF were treated with the Mfn2 overexpressing lentivirus (adv-Mfn2). The cell cycle was detected by flow cytometry. MTT, PCR and Western blotting were used to investigate the effect of Mfn2 on the proliferation of the HELF, collagen expression, the RAS-RAF-1-ERK1/2 pathway and the expression of cycle-related proteins (p21, p27, Rb, Raf-1, p-Raf-1, Erk1/2 and p-Erk1/2). The co-immunoprecipitation assay was used to explore the interaction between Mfn2 and Ras. The results showed that the overexpression of Mfn2 inhibited the proliferation of the HELF and induced the cell cycle arrest at the G0/G1 phase. Meanwhile, Mfn2 also inhibited the expression of collagen I, p-Erk and p-Raf-1. In addition, an interaction between Mfn2 and Ras existed in the HELF. This study suggests that the overexpression of Mfn2 can decrease the proliferation of HELF in ARDS, which was associated with the inhibition of the RAS-RAF-1-ERK1/2 pathway. The results may offer a potential therapeutic intervention for patients with ARDS.
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Affiliation(s)
- Juan Li
- Department of Critical Care Medicine, Wuhan Fourth Hospital (Puai Hospital), Tongji Medical College, Huazhong University of Science and Technology, Wuhan, 430030, China
| | - Mei-Xia Xu
- Department of Critical Care Medicine, Wuhan Fourth Hospital (Puai Hospital), Tongji Medical College, Huazhong University of Science and Technology, Wuhan, 430030, China
| | - Zhong Dai
- Department of Critical Care Medicine, Wuhan Fourth Hospital (Puai Hospital), Tongji Medical College, Huazhong University of Science and Technology, Wuhan, 430030, China
| | - Tao Xu
- Department of Critical Care Medicine, Wuhan Fourth Hospital (Puai Hospital), Tongji Medical College, Huazhong University of Science and Technology, Wuhan, 430030, China.
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Shu Z, Zhang X, Zheng L, Zeng G, Mo Y, Yu M, Zhang X, Tan X. Epigallocatechin-3-gallate regulates mitofusin 2 expression through the peroxisome proliferator-activated receptor-γ coactivator-1α and estrogen-related receptor-α pathway. J Cell Biochem 2019; 120:7211-7221. [PMID: 30387209 DOI: 10.1002/jcb.27995] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/05/2018] [Accepted: 10/08/2018] [Indexed: 02/05/2023]
Abstract
Our previous study showed that epigallocatechin-3-gallate (EGCG) inhibition of human aortic smooth muscle cell (HASMC) proliferation might be mediated via upregulation of mitofusin 2 (Mfn-2). Studies on the mechanism of Mfn-2 inhibition of cell proliferation have mainly focused on downstream signaling. However, it is still not clear how upstream signaling molecules regulate Mfn-2. The promoter region of the Mfn-2 gene contains cis-acting elements of peroxisome proliferator-activated receptor-γ coactivator-1α (PGC-1α) and estrogen-related receptor-α (ERR-α), suggesting a possible link between EGCG, Mfn-2, and PGC-1α/ERR-α. However, the effect of EGCG on PGC-1α/ERR-α remains unknown. In this study, we investigated the role of PGC-1α/ERR-α in the regulation of Mfn-2 induced by EGCG and assessed the underlying mechanisms. The effects of EGCG on cell proliferation of cultured HASMCs were observed by a cell counting kit-8 (CCK8) and 5-ethynyl-2-deoxyuridine (EdU) incorporation assay. Mfn-2, PGC-1α, and ERR-α gene and protein levels were determined by quantitative real-time polymerase chain reaction (PCR) and Western blot analysis. PGC-1α gene-silencing (PGC-1α small interfering RNA [siRNA]) was achieved by RNA interference and Mfn-2 promoter and peroxisome proliferator response element (PPRE) functional activity was achieved by a luciferase transfection assay. The results showed that the ERR-α-specific antagonist XCT-790 and PGC-1α siRNA decreased the expression of Mfn-2, thus antagonizing the inhibition of HASMC proliferation induced by EGCG. EGCG enhanced Mfn-2 promoter (-352 to 459) activity, while XCT-790 and PGC-1α siRNA abrogated this effect. PGC-1α stimulating Mfn-2 expression was dependent on intact ERR-α binding in the Mfn-2 promoter. The transcriptional effect of PGC-1α on the Mfn-2 promoter required the integrity of the -432 to 459 region and supported that Mfn-2 was a key target gene of PGC-1α. These results imply that PGC-1α/ERR-α played important physiological roles in inhibiting the proliferation of HASMCs by modulating Mfn-2 gene expression. Hence, EGCG regulated Mfn-2 expression likely through the PGC-1α/ERR-α pathway.
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Affiliation(s)
- ZhouWu Shu
- Department of Cardiology, The First Affiliated Hospital of Shantou University Medical College, Shantou, China
- Molecular Biology Laboratory, The First Affiliated Hospital of Shantou University Medical College, Shantou, China
| | - XiaoCong Zhang
- Department of Cardiology, The First Affiliated Hospital of Shantou University Medical College, Shantou, China
| | - Li Zheng
- Department of Cardiology, The First Affiliated Hospital of Shantou University Medical College, Shantou, China
| | - GuoNing Zeng
- Department of Cardiology, The First Affiliated Hospital of Shantou University Medical College, Shantou, China
| | - You Mo
- Department of Cardiology, The First Affiliated Hospital of Shantou University Medical College, Shantou, China
| | - Min Yu
- Department of Cardiology, The First Affiliated Hospital of Shantou University Medical College, Shantou, China
- Molecular Biology Laboratory, The First Affiliated Hospital of Shantou University Medical College, Shantou, China
| | - Xin Zhang
- Molecular Biology Laboratory, The First Affiliated Hospital of Shantou University Medical College, Shantou, China
| | - XueRui Tan
- Department of Cardiology, The First Affiliated Hospital of Shantou University Medical College, Shantou, China
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Allegra A, Innao V, Allegra AG, Musolino C. Relationship between mitofusin 2 and cancer. ADVANCES IN PROTEIN CHEMISTRY AND STRUCTURAL BIOLOGY 2018; 116:209-236. [PMID: 31036292 DOI: 10.1016/bs.apcsb.2018.11.009] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/12/2023]
Abstract
Mitochondria are dynamic organelles whose actions are fundamental for cell viability. Within the cell, the mitochondrial system is incessantly modified via the balance between fusion and fission processes. Among other proteins, mitofusin 2 is a central protagonist in all these mitochondrial events (fusion, trafficking, contacts with other organelles), the balance of which causes the correct mitochondrial action, shape, and distribution within the cell. Here we examine the structural and functional characteristics of mitofusin 2, underlining its essential role in numerous intracellular pathways, as well as in the pathogenesis of cancer.
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Affiliation(s)
- Alessandro Allegra
- Division of Hematology, Department of Human Pathology in Adulthood and Childhood "Gaetano Barresi", University of Messina, Messina, Italy.
| | - Vanessa Innao
- Division of Hematology, Department of Human Pathology in Adulthood and Childhood "Gaetano Barresi", University of Messina, Messina, Italy
| | - Andrea Gaetano Allegra
- Division of Hematology, Department of Human Pathology in Adulthood and Childhood "Gaetano Barresi", University of Messina, Messina, Italy
| | - Caterina Musolino
- Division of Hematology, Department of Human Pathology in Adulthood and Childhood "Gaetano Barresi", University of Messina, Messina, Italy
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Yu F, Xu T, Wang M, Chang W, Li P, Wang J. Function and regulation of mitofusin 2 in cardiovascular physiology and pathology. Eur J Cell Biol 2018; 97:474-482. [DOI: 10.1016/j.ejcb.2018.07.003] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/10/2018] [Revised: 07/06/2018] [Accepted: 07/17/2018] [Indexed: 02/03/2023] Open
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Shi Y, Yi C, Li X, Wang J, Zhou F, Chen X. Overexpression of Mitofusin2 decreased the reactive astrocytes proliferation in vitro induced by oxygen-glucose deprivation/reoxygenation. Neurosci Lett 2016; 639:68-73. [PMID: 28013092 DOI: 10.1016/j.neulet.2016.12.052] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/15/2016] [Revised: 12/19/2016] [Accepted: 12/20/2016] [Indexed: 11/19/2022]
Abstract
Glia scar is a hallmark in late-stage of brain stroke disease, which hinder axonal regeneration and neuronal repair. Mitofusin2 (Mfn2) is a newly found cellular proliferation inhibitor. This study is to elucidate the role of Mfn2 in reactive astrocytes induced by oxygen-glucose deprivation/reoxygenation(OGD/R) model in vitro. Up-expression in EdU staining and protein level of GFAP, PCNA and CyclinD1, demonstrates the distinct activation and proliferation of astrocytes after the stimulation of OGD/R. Meanwhile, Mfn2 was proved to be down-regulated both in gene and protein levels. Pretreatment of cells with adenoviral vector encoding Mfn2 gene increased Mfn2 expression and subsequently attenuated OGD-induced astrocyte proliferation. Down-regulation of Ras-p-Raf1-p-ERK1/2 pathway and cell cycle arrest were found to be relevant. Together, these results suggested that overexpression of Mfn2 can effectively inhibit the proliferation of reactive astrogliosis, which might contribute to a promising therapeutic intervention in cerebral ischemic injury.
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Affiliation(s)
- Yulong Shi
- Department of Traumatic Surgery, Tong-ji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, Jie Fang Avenue 1095, China
| | - Chengla Yi
- Department of Traumatic Surgery, Tong-ji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, Jie Fang Avenue 1095, China.
| | - Xiao Li
- Department of Neurology, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, Hubei 430030, China
| | - Jiangpeng Wang
- Department of Traumatic Surgery, Tong-ji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, Jie Fang Avenue 1095, China
| | - Fangyuan Zhou
- Department of Traumatic Surgery, Tong-ji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, Jie Fang Avenue 1095, China
| | - Xiaoqian Chen
- Department of Pathophysiology, School of Basic Medicine, Key Laboratory of Neurological Diseases, Ministry of Education and Hubei Provincial Key Laboratory of Neurological Diseases, Tongji Medical College, Huazhong University of Science and Technology, Wuhan 430030, China
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Lv P, Zhang F, Yin YJ, Wang YC, Gao M, Xie XL, Zhao LL, Dong LH, Lin YL, Shu YN, Zhang DD, Liu GX, Han M. SM22α inhibits lamellipodium formation and migration via Ras-Arp2/3 signaling in synthetic VSMCs. Am J Physiol Cell Physiol 2016; 311:C758-C767. [PMID: 27629412 DOI: 10.1152/ajpcell.00033.2016] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/04/2016] [Accepted: 09/07/2016] [Indexed: 02/03/2023]
Abstract
We previously demonstrated that smooth muscle (SM) 22α promotes the migration activity in contractile vascular smooth muscle cells (VSMCs). Based on the varied functions exhibited by SM22α in different VSMC phenotypes, we investigated the effect of SM22α on VSMC migration under pathological conditions. The results demonstrated that SM22α overexpression in synthetic VSMCs inhibited platelet-derived growth factor (PDGF)-BB-induced cell lamellipodium formation and migration, which was different from its action in contractile cells. The results indicated two distinct mechanisms underlying inhibition of lamellipodium formation by SM22α, increased actin dynamic stability and decreased Ras activity via interference with interactions between Ras and guanine nucleotide exchange factor. The former inhibited actin cytoskeleton rearrangement in the cell cortex, while the latter significantly disrupted actin nucleation activation of the Arp2/3 complex. Baicalin, a herb-derived flavonoid compound, inhibited VSMC migration via upregulation of SM22α expression in vitro and in vivo. These data suggest that SM22α regulates lamellipodium formation and cell migration in a phenotype-dependent manner in VSMCs, which may be a new therapeutic target for vascular lesion formation.
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Affiliation(s)
- Pin Lv
- Key Laboratory of Medical Biotechnology of Hebei Province, Department of Biochemistry and Molecular Biology, College of Basic Medicine, Hebei Medical University, Shijiazhuang, China
| | - Fan Zhang
- Key Laboratory of Medical Biotechnology of Hebei Province, Department of Biochemistry and Molecular Biology, College of Basic Medicine, Hebei Medical University, Shijiazhuang, China
| | - Ya-Juan Yin
- Key Laboratory of Medical Biotechnology of Hebei Province, Department of Biochemistry and Molecular Biology, College of Basic Medicine, Hebei Medical University, Shijiazhuang, China
| | - Yu-Can Wang
- Key Laboratory of Medical Biotechnology of Hebei Province, Department of Biochemistry and Molecular Biology, College of Basic Medicine, Hebei Medical University, Shijiazhuang, China
| | - Min Gao
- Key Laboratory of Medical Biotechnology of Hebei Province, Department of Biochemistry and Molecular Biology, College of Basic Medicine, Hebei Medical University, Shijiazhuang, China
| | - Xiao-Li Xie
- Key Laboratory of Medical Biotechnology of Hebei Province, Department of Biochemistry and Molecular Biology, College of Basic Medicine, Hebei Medical University, Shijiazhuang, China
| | - Li-Li Zhao
- Key Laboratory of Medical Biotechnology of Hebei Province, Department of Biochemistry and Molecular Biology, College of Basic Medicine, Hebei Medical University, Shijiazhuang, China
| | - Li-Hua Dong
- Key Laboratory of Medical Biotechnology of Hebei Province, Department of Biochemistry and Molecular Biology, College of Basic Medicine, Hebei Medical University, Shijiazhuang, China
| | - Yan-Ling Lin
- Key Laboratory of Medical Biotechnology of Hebei Province, Department of Biochemistry and Molecular Biology, College of Basic Medicine, Hebei Medical University, Shijiazhuang, China
| | - Ya-Nan Shu
- Key Laboratory of Medical Biotechnology of Hebei Province, Department of Biochemistry and Molecular Biology, College of Basic Medicine, Hebei Medical University, Shijiazhuang, China
| | - Dan-Dan Zhang
- Key Laboratory of Medical Biotechnology of Hebei Province, Department of Biochemistry and Molecular Biology, College of Basic Medicine, Hebei Medical University, Shijiazhuang, China
| | - Gui-Xia Liu
- Key Laboratory of Medical Biotechnology of Hebei Province, Department of Biochemistry and Molecular Biology, College of Basic Medicine, Hebei Medical University, Shijiazhuang, China
| | - Mei Han
- Key Laboratory of Medical Biotechnology of Hebei Province, Department of Biochemistry and Molecular Biology, College of Basic Medicine, Hebei Medical University, Shijiazhuang, China
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Mitofusin-2 over-expresses and leads to dysregulation of cell cycle and cell invasion in lung adenocarcinoma. Med Oncol 2015; 32:132. [PMID: 25796500 DOI: 10.1007/s12032-015-0515-0] [Citation(s) in RCA: 37] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/16/2015] [Accepted: 02/13/2015] [Indexed: 10/23/2022]
Abstract
Mitofusin-2 (MFN2) is a mitochondrial protein associated with mitochondrial fusion process. It was initially identified as a hyperplasia suppressor and implicated in Charcot-Marie-Tooth disease. Recent studies showed that MFN2 played important roles in the development of multiple tumors. Here we examined MFN2 expression in 30 lung adenocarcinoma samples and revealed that the expression of MFN2 was significantly higher in lung adenocarcinoma tissues as compared to adjacent normal tissues. We then investigated the impact of MFN2 knockdown on A549 human lung adenocarcinoma cells and showed that cell proliferation, cell cycle and invasion behavior were all deregulated by MFN2 knockdown. And deregulation of cell cycle pathway after MFN2 knockdown was confirmed by microarray analysis. Furthermore, microarray analysis also revealed that different oncogenes such as RAP1A, RALB and ITGA2 were oppositely regulated by MFN2, which provided molecular clues for the paradoxical functions of MFN2 in tumor development. Taken together, our study unraveled the tumor-promoting functions of MFN2 in lung adenocarcinoma and implicated that the role of MFN2 in cancer development might be more complicated than expected and should be explored in detail in the future.
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Shu Z, Yu M, Zeng G, Zhang X, Wu L, Tan X. Epigallocatechin-3-gallate inhibits proliferation of human aortic smooth muscle cells via up-regulating expression of mitofusin 2. Eur J Cell Biol 2014; 93:137-44. [PMID: 24880525 DOI: 10.1016/j.ejcb.2014.04.001] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/27/2013] [Revised: 04/23/2014] [Accepted: 04/24/2014] [Indexed: 02/05/2023] Open
Abstract
Previous studies have shown that epigallocatechin-3-gallate (EGCG) inhibits the proliferation of vascular smooth muscle cells (VSMCs) via the extracellular-signal-regulated kinase (ERK1/2) and mitogen activated protein kinases (MAPKs) pathway. Mitofusin 2 (Mfn-2) also suppresses VSMC proliferation through Ras-Raf-ERK/MAPK, suggesting a possible link between EGCG, Mfn-2 and ERK/MAPK. However, the effect of EGCG on Mfn-2 remains unknown. In this study, we investigated the role of Mfn-2 in the regulation of VSMC proliferation by EGCG, and assessed the underlying mechanisms. The effects of EGCG on the proliferation of cultured human aortic smooth muscle cells (HASMCs) were observed by 5-ethynl-2-deoxyuridine (EdU) incorporation assay. Mfn-2 gene and protein levels, and Ras, p-c-Raf and p-ERK1/2 protein levels were determined by quantitative real-time polymerase chain reaction and western blotting, respectively. Mfn-2 gene silencing was achieved by RNA interference. EGCG 50 μmol/L profoundly inhibited the proliferation of HASMCs in culture, up-regulated Mfn-2, and down-regulated the expression of p-c-Raf and p-ERK1/2. Furthermore, RNA interference-mediated gene knockdown of Mfn-2 antagonized EGCG-induced anti-proliferation and down-regulation of Ras, p-c-Raf and p-ERK1/2. These results suggest that EGCG inhibits the proliferation of HASMCs in vitro largely via Mfn-2-mediated suppression of the Ras-Raf-ERK/MAPK signaling pathway.
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Affiliation(s)
- Zhouwu Shu
- Department of Cardiology, The First Affiliated Hospital of Shantou University Medical College, Shantou, Guangdong 515041, China; Molecular Biology Laboratory, The First Affiliated Hospital of Shantou University Medical College, Shantou, Guangdong 515041, China
| | - Min Yu
- Department of Cardiology, The First Affiliated Hospital of Shantou University Medical College, Shantou, Guangdong 515041, China; Molecular Biology Laboratory, The First Affiliated Hospital of Shantou University Medical College, Shantou, Guangdong 515041, China
| | - Guoning Zeng
- Molecular Biology Laboratory, The First Affiliated Hospital of Shantou University Medical College, Shantou, Guangdong 515041, China
| | - Xin Zhang
- Molecular Biology Laboratory, The First Affiliated Hospital of Shantou University Medical College, Shantou, Guangdong 515041, China
| | - Libiao Wu
- Molecular Biology Laboratory, The First Affiliated Hospital of Shantou University Medical College, Shantou, Guangdong 515041, China
| | - Xuerui Tan
- Department of Cardiology, The First Affiliated Hospital of Shantou University Medical College, Shantou, Guangdong 515041, China.
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Chen KH, Dasgupta A, Ding J, Indig FE, Ghosh P, Longo DL. Role of mitofusin 2 (Mfn2) in controlling cellular proliferation. FASEB J 2013; 28:382-94. [PMID: 24081906 DOI: 10.1096/fj.13-230037] [Citation(s) in RCA: 88] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
It has been reported that Mitofusin2 (Mfn2) inhibits cell proliferation when overexpressed. We wanted to study the role of endogenous Mfn2 in cell proliferation, along with the structural features of Mfn2 that influence its mitochondrial localization and control of cell proliferation. Mfn2-knockdown clones of a B-cell lymphoma cell line BJAB exhibited an increased rate of cell proliferation. A 2-fold increase in cell proliferation was also observed in Mfn2-knockout mouse embryonic fibroblast (MEF) cells as compared with the control wild-type cells, and the proliferative advantage of the knockout MEF cells was blocked on reintroduction of the Mfn2 gene. Mfn2 exerts its antiproliferative effect by acting as an effector molecule of Ras, resulting in the inhibition of the Ras-Raf-ERK signaling pathway. Furthermore, both the N-terminal (aa 1-264) and the C-terminal (aa 265-757) fragments of Mfn2 blocked cell proliferation through distinct mechanisms: the N-terminal-mediated inhibition was due to its interaction with Raf-1, whereas the C-terminal fragment of Mfn2 inhibited cell proliferation by interacting with Ras. The inhibition of proliferation by the N-terminal fragment was independent of its mitochondrial localization. Collectively, our data provide new insights regarding the role of Mfn2 in controlling cellular proliferation.
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Affiliation(s)
- Kuang-Hueih Chen
- 2Lymphocyte Cell Biology Unit, Laboratory of Genetics, National Institute on Aging, National Institutes of Health, Biomedical Research Center, 251 Bayview Blvd., Baltimore, MD 21224, USA. P.G.,
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13
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Sulforaphane inhibits smooth muscle cell proliferation and migration by reducing MMP-9 activity via the Ras and RhoA/ROCK pathways. J Funct Foods 2013. [DOI: 10.1016/j.jff.2013.03.005] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022] Open
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Valsartan inhibits angiotensin II-induced proliferation of vascular smooth muscle cells via regulating the expression of mitofusin 2. ACTA ACUST UNITED AC 2012; 32:31-35. [DOI: 10.1007/s11596-012-0005-y] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/19/2011] [Indexed: 01/07/2023]
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Radhakrishnan K, Edwards JS, Lidke DS, Jovin TM, Wilson BS, Oliver JM. Sensitivity analysis predicts that the ERK-pMEK interaction regulates ERK nuclear translocation. IET Syst Biol 2011; 3:329-41. [PMID: 21028924 DOI: 10.1049/iet-syb.2009.0010] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022] Open
Abstract
Following phosphorylation, nuclear translocation of the mitogen-activated protein kinases (MAPKs), ERK1 and ERK2, is critical for both gene expression and DNA replication induced by growth factors. ERK nuclear translocation has therefore been studied extensively, but many details remain unresolved, including whether or not ERK dimerisation is required for translocation. Here, we simulate ERK nuclear translocation with a compartmental computational model that includes systematic sensitivity analysis. The governing ordinary differential equations are solved with the backward differentiation formula and decoupled direct methods. To better understand the regulation of ERK nuclear translocation, we use this model in conjunction with a previously published model of the ERK pathway that does not include an ERK dimer species and with experimental measurements of nuclear translocation of wild-type ERK and a mutant form, ERK1-4, which is unable to dimerise. Sensitivity analysis reveals that the delayed nuclear uptake of ERK1-4 compared to that of wild-type ERK1 can be explained by the altered interaction of ERK1-4 with phosphorylated MEK (MAPK/ERK kinase), and so may be independent of dimerisation. Our study also identifies biological experiments that can verify this explanation.
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Affiliation(s)
- K Radhakrishnan
- University of New Mexico School of Medicine, Department of Pathology and Cancer Center, Albuquerque, NM, USA.
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16
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Zheng M, Xiao RP. Role of mitofusin 2 in cardiovascular oxidative injury. J Mol Med (Berl) 2010; 88:987-91. [PMID: 20824264 DOI: 10.1007/s00109-010-0675-5] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/28/2010] [Revised: 08/16/2010] [Accepted: 08/16/2010] [Indexed: 01/27/2023]
Abstract
Mitochondria are highly dynamic organelles with constant shape changes regulated by fusion and fission events. In addition to regulating mitochondrial morphology, mitochondrial fusion/fission is involved in fundamental mitochondrial biological processes, including mitochondrial metabolism, energization, respiration, mitochondrial membrane potential, and mtDNA stability. Dysfunction of mitochondrial dynamics has been implicated in various human diseases, especially in neurodegenerative diseases. Emerging evidence indicates that impaired expression of mitochondrial fusion proteins or their malfunction participates in oxidative stress-induced cardiovascular injury. This review will focus on recent advances of mitochondrial fusion in regulating various cellular processes in cardiovascular system.
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Affiliation(s)
- Ming Zheng
- Institute of Molecular Medicine, Peking University, Beijing, 100871, People's Republic of China
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Mutation of the protein kinase A phosphorylation site influences the anti-proliferative activity of mitofusin 2. Atherosclerosis 2010; 211:216-23. [DOI: 10.1016/j.atherosclerosis.2010.02.012] [Citation(s) in RCA: 47] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/02/2009] [Revised: 02/05/2010] [Accepted: 02/08/2010] [Indexed: 11/23/2022]
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Heo SK, Yun HJ, Park WH, Park SD. Emodin inhibits TNF-alpha-induced human aortic smooth-muscle cell proliferation via caspase- and mitochondrial-dependent apoptosis. J Cell Biochem 2008; 105:70-80. [PMID: 18494000 DOI: 10.1002/jcb.21805] [Citation(s) in RCA: 50] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
Vascular smooth-muscle cell (VSMC) proliferation plays a vital role in hypertension, atherosclerosis and restenosis. It has been reported that emodin, an active component extracted from rhubarb, can stop the growth of cancer cells; however, it is not known if emodin exerts similar anti-atherogenic effects in TNF-alpha treated human aortic smooth-muscle cells (HASMC). In this study, emodin treatment showed potent inhibitory effects in TNF-alpha-induced HASMC proliferation that were associated with induced apoptosis, including the cleavage of poly ADP-ribose polymerase (PARP). Moreover, inhibitors of caspase-3, -8 and -9 (Ac-DEVD-CHO, Z-IETD-FMK and Z-LEHD-FMK) efficiently blocked emodin-induced apoptosis in TNF-alpha treated HASMC. Therefore, emodin-induced cell death occurred via caspase-dependent apoptosis. Emodin treatment resulted in the release of cytochrome c into cytosol and a loss of mitochondrial membrane potential (DeltaPsi(m)), as well as a decrease in the expression of an anti-apoptotic protein (Bcl-2) and an increase in the expression of an a pro-apoptotic protein (Bax). Emodin-mediated apoptosis was also blocked by a mitochondrial membrane depolarization inhibitor, which indicates that emodin-induced apoptosis occurred via a mitochondrial pathway. Taken together, the results of this study showed that emodin inhibits TNF-alpha-induced HASMC proliferation via caspase- and a mitochondrial-dependent apoptotic pathway. In addition, these results indicate that emodin has potential as an anti-atherosclerosis agent.
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Affiliation(s)
- Sook-Kyoung Heo
- Cardiovascular Medical Research Center and Department of Prescriptionology University of Dongguk, Gyeongju City, Gyeongbuk 780-714, Republic of Korea
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Regulation of myosin light chain kinase expression by angiotensin II in hypertension. Am J Hypertens 2008; 21:860-5. [PMID: 18511912 DOI: 10.1038/ajh.2008.199] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022] Open
Abstract
BACKGROUND Increased growth and contraction of vascular smooth muscle cells (VSMCs) are major abnormalities in many vascular disorders. To investigate the signaling pathways that mediate these processes, we studied the expression of smooth muscle myosin light chain kinase (smMLCK) in VSMCs. METHODS Primary cultured VSMCs isolated from normotensive Wistar-Kyoto (WKY) rats were treated with angiotensin II (Ang II). smMLCK expression was examined in the cells using western blot analysis. In vivo, a specific inhibitor of smMLCK or MAP kinase kinase (MEK) was delivered to spontaneously hypertensive rats (SHRs) using an osmotic pump, and their blood pressures were measured using tail-cuff sphygmomanometry. RESULTS Expression of smMLCK protein is rapidly increased by Ang II, an important agonist responsible for increased vasoconstriction and vascular remodeling, in concert with increased myosin light chain phosphorylation. Inhibiting Ang II type 1 (AT1) receptor, Ras, or MEK blocked the Ang II-induced increase in smMLCK expression. In vivo, inhibiting MEK decreased smMLCK expression, blood pressure, and vascular thickening in SHRs. Moreover, inhibiting smMLCK activity decreased blood pressure and smooth muscle mass in arteries in SHRs. CONCLUSIONS The regulation of smMLCK expression by Ang II via Ras signaling is important in the regulation of vascular remodeling and blood pressure. Targeting this pathway could be an effective strategy for developing novel therapeutics to treat hypertension.
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Lasater EA, Bessler WK, Mead LE, Horn WE, Clapp DW, Conway SJ, Ingram DA, Li F. Nf1+/- mice have increased neointima formation via hyperactivation of a Gleevec sensitive molecular pathway. Hum Mol Genet 2008; 17:2336-44. [PMID: 18442999 DOI: 10.1093/hmg/ddn134] [Citation(s) in RCA: 51] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022] Open
Abstract
Neurofibromatosis type I (NF1) is a genetic disorder caused by mutations in the NF1 tumor suppressor gene. Neurofibromin is encoded by NF1 and functions as a negative regulator of Ras activity. Somatic mutations in the residual normal NF1 allele within cancers of NF1 patients is consistent with NF1 functioning as a tumor-suppressor. However, the prevalent non-malignant manifestations of NF1, including learning and bone disorders emphasize the importance of dissecting the cellular and biochemical effects of NF1 haploinsufficiency in multiple cell lineages. One of the least studied complications of NF1 involves cardiovascular disorders, including arterial occlusions that result in cerebral and visceral infarcts. NF1 vasculopathy is characterized by vascular smooth muscle cell (VSMC) accumulation in the intima area of vessels resulting in lumen occlusion. We recently showed that Nf1 haploinsufficiency increases VSMC proliferation and migration via hyperactivation of the Ras-Erk pathway, which is a signaling axis directly linked to neointima formation in diverse animal models of vasculopathy. Given this observation, we tested whether heterozygosity of Nf1 would lead to vaso-occlusive disease in genetically engineered mice in vivo. Strikingly, Nf1+/- mice have increased neointima formation, excessive vessel wall cell proliferation and Erk activation after vascular injury in vivo. Further, this effect is directly dependent on a Gleevec sensitive molecular pathway. Therefore, these studies establish an Nf1 model of vasculopathy, which mirrors features of human NF1 vaso-occlusive disease, identifies a potential therapeutic target and provides a platform to further dissect the effect of Nf1 haploinsufficiency in cardiovascular disease.
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Affiliation(s)
- Elisabeth A Lasater
- Department of Pediatrics, Indiana University School of Medicine, Indianapolis, IN 46202, USA
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Comparison of the efficacies of five different statins on inhibition of human saphenous vein smooth muscle cell proliferation and invasion. J Cardiovasc Pharmacol 2008; 50:458-61. [PMID: 18049315 DOI: 10.1097/fjc.0b013e318123767f] [Citation(s) in RCA: 45] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
Statins (HMG-CoA reductase inhibitors) exhibit beneficial effects on the vasculature independently of their cholesterol-lowering properties. These pleiotropic effects underlie the ability of statins to reduce intimal hyperplasia in saphenous vein (SV) bypass grafts by attenuating smooth muscle cell (SMC) invasion and proliferation. Although all statins can effectively lower cholesterol, the pleiotropic effects of individual statins may well differ. We therefore compared the concentration-dependent effects of 4 lipophilic statins (simvastatin, atorvastatin, fluvastatin, and lovastatin) and 1 hydrophilic statin (pravastatin) on the proliferation and invasion of SMC cultured from SV of 9 different patients undergoing coronary artery bypass grafting (CABG). The lipophilic statins inhibited SV-SMC proliferation over a 4-day period with an order of potency of fluvastatin > atorvastatin > simvastatin > lovastatin (IC50 range = 0.07 to 1.77 microM). Similarly, these statins also inhibited SV-SMC invasion through an artificial basement membrane barrier (fluvastatin > atorvastatin > simvastatin >> lovastatin; IC50 range = 0.92 to 26.9 microM). In contrast, the hydrophilic pravastatin had no significant effect on SV-SMC proliferation at concentrations up to 10 microM, nor did it attenuate SV-SMC invasion (up to 30 microM). Our data provide strong evidence that individual statins possess differential pleiotropic effects on SV-SMC function. This may be of clinical relevance in the selection of individual statins for the treatment of CABG patients.
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Guo X, Chen KH, Guo Y, Liao H, Tang J, Xiao RP. Mitofusin 2 Triggers Vascular Smooth Muscle Cell Apoptosis via Mitochondrial Death Pathway. Circ Res 2007; 101:1113-22. [PMID: 17901359 DOI: 10.1161/circresaha.107.157644] [Citation(s) in RCA: 147] [Impact Index Per Article: 8.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Abstract
Previous studies have shown that mitofusin 2 (Mfn-2) (or hyperplasia suppressor gene [HSG]) inhibits vascular smooth muscle cell (VSMC) proliferation. Here, we demonstrate that Mfn-2 is a primary determinant of VSMC apoptosis. First, oxidative stress with H2O2, inhibition of protein kinase C with staurosporine, activation of protein kinase A with forskolin, and serum deprivation concurrently elevate Mfn-2 expression and induce VSMC apoptosis. Second, overexpression of Mfn-2 also triggers apoptosis of VSMCs in culture and in balloon-injured rat carotid arteries, thus contributing to Mfn-2-mediated prevention of neointima formation after angioplasty. Third, Mfn-2 silencing protects VSMCs against H2O2 or Mfn-2 overexpression-induced apoptosis, indicating that upregulation of Mfn-2 is necessary and sufficient for oxidative stress-mediated VSMC apoptosis. The Mfn-2 proapoptotic effect is independent of its role in mitochondrial fusion but mainly mediated by inhibition of Akt signaling and the resultant activation of the mitochondrial apoptotic pathway, as manifested by decreased Akt phosphorylation, increased mitochondrial Bax/Bcl-2 ratio, cytochrome c release, and activation of caspases-9 and caspase-3. Furthermore, Mfn-2-induced apoptosis was blocked by overexpression of an active phosphoinositide 3-kinase mutant or Bcl-xL or inhibition of caspase-9 but not caspases-8. Thus, in addition to its antiproliferative effects, Mfn-2 constitutes a primary determinant of VSMC apoptosis.
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Affiliation(s)
- Xiaomei Guo
- Laboratory of Cardiovascular Science, Gerontology Research Center, NIA, NIH, 5600 Nathan Shock Dr, Baltimore, MD 21224, USA
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Guo YH, Chen K, Gao W, Li Q, Chen L, Wang GS, Tang J. Overexpression of Mitofusin 2 inhibited oxidized low-density lipoprotein induced vascular smooth muscle cell proliferation and reduced atherosclerotic lesion formation in rabbit. Biochem Biophys Res Commun 2007; 363:411-7. [PMID: 17880918 DOI: 10.1016/j.bbrc.2007.08.191] [Citation(s) in RCA: 50] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/23/2007] [Accepted: 08/30/2007] [Indexed: 01/03/2023]
Abstract
Our previous studies have implies that Mitofusin 2 (Mfn2), which was progressively reduced in arteries from ApoE(-/-) mice during the development of atherosclerosis, may take part in pathogenesis of atherosclerosis. In this study, we found that overexpression of Mfn2 inhibited oxidized low-density lipoprotein or serum induced vascular smooth muscle cell proliferation by down-regulation of Akt and ERK phosphorylation. Then we investigated the in vivo role of Mfn2 on the development of atherosclerosis in rabbits using adenovirus expressing Mitofusin 2 gene (AdMfn2). By morphometric analysis we found overexpression of Mfn2 inhibited atherosclerotic lesion formation and intima/media ratio by 66.7% and 74.6%, respectively, compared with control group. These results suggest that local Mfn2 treatment suppresses the development of atherosclerosis in vivo in part by attenuating the smooth muscle cell proliferation induced by lipid deposition and vascular injury.
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Affiliation(s)
- Yan-Hong Guo
- Department of Cardiology, Peking University Third Hospital, Key Laboratory of Molecular Cardiovascular Science, Ministry of Education, No. 49, North Garden Road, Beijing 100083, China
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Shirai H, Autieri M, Eguchi S. Small GTP-binding proteins and mitogen-activated protein kinases as promising therapeutic targets of vascular remodeling. Curr Opin Nephrol Hypertens 2007; 16:111-5. [PMID: 17293685 DOI: 10.1097/mnh.0b013e3280148e4f] [Citation(s) in RCA: 44] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
PURPOSE OF REVIEW To summarize the most recent findings concerning the targeting of mitogen-activated protein kinases and small GTP-binding proteins toward vascular remodeling together with molecular mechanisms of their activations in vascular pathophysiology. RECENT FINDINGS In addition to targeting the classical Ras/extracellular signal-regulated kinase cascade, Rho-kinase inhibitors, as well as the HMG-CoA reductase inhibitors, or 'statins', have pleiotropic efficacy for experimental cardiovascular diseases that involve inhibition of the signal transduction cascades originated by the small GTP-binding proteins such as Rho and Rac. Moreover, the underlying molecular mechanisms of the activation of these small GTP-binding proteins and downstream mitogen-activated protein kinases in cardiovascular tissue and cells have recently been better characterized. Additionally, gene-targeting studies in animal models are revealing select roles of the isoforms of these signaling proteins in the pathophysiology of cardiovascular disease. This is exemplified by the role of c-Jun NH(2)-terminal kinases in mediating atherosclerosis and diabetes. SUMMARY Characterization of the function of small GTP-binding proteins, mitogen-activated protein kinases and their effectors in cardiovascular pathophysiology can be readily identified by using select inhibitors, dominant-negative gene transfer and the generation of select gene-targeted animals. These findings strongly support the notion that small GTP-binding proteins and mitogen-activated protein kinases are promising therapeutic targets toward cardiovascular diseases.
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Affiliation(s)
- Heigoro Shirai
- Cardiovascular Research Center and Department of Physiology, Temple University School of Medicine, Philadelphia, Pennsylvania 19140, USA
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Ohtsu H, Suzuki H, Nakashima H, Dhobale S, Frank GD, Motley ED, Eguchi S. Angiotensin II Signal Transduction Through Small GTP-Binding Proteins. Hypertension 2006; 48:534-40. [PMID: 16923993 DOI: 10.1161/01.hyp.0000237975.90870.eb] [Citation(s) in RCA: 81] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Affiliation(s)
- Haruhiko Ohtsu
- Cardiovascular Research Center and Department of Physiology, Temple University School of Medicine, Philadelphia, PA 19140, USA
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Santel A. Get the balance right: Mitofusins roles in health and disease. BIOCHIMICA ET BIOPHYSICA ACTA-MOLECULAR CELL RESEARCH 2006; 1763:490-9. [PMID: 16574259 DOI: 10.1016/j.bbamcr.2006.02.004] [Citation(s) in RCA: 44] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/30/2005] [Revised: 02/07/2006] [Accepted: 02/13/2006] [Indexed: 01/08/2023]
Abstract
Mitochondria are highly dynamic organelles exhibiting an elaborate morphology and fine structure. Fusion and fission processes contribute to the maintenance and dynamics of mitochondrial morphology. The Mitofusins, a class of evolutionary conserved GTPases of the mitochondrial outer membrane, are essential for the controlled fusion of mitochondrial membranes. Genetic and biochemical data propose a model in which functional domains, such as the GTPase domain and the C-terminally located coiled coil structure, act in an orchestrated manner to coordinate the tethering and mitochondrial outer membrane fusion. In addition, recent reports shed new light on the physiological importance of Mitofusin function suggesting a role in mitochondrial metabolism, apoptosis as well as cellular signalling. Mutations identified in the human Mfn2 gene from patients with the peripheral neuropathy Charcot-Marie-Tooth Type 2A invoke a direct correlation between mitochondrial morphology and function.
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Affiliation(s)
- Ansgar Santel
- Atugen AG/SR Pharma plc, Otto-Warburg-Haus, Robert-Rössle-Str.10, 13125 Berlin, Germany.
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Li F, Munchhof AM, White HA, Mead LE, Krier TR, Fenoglio A, Chen S, Wu X, Cai S, Yang FC, Ingram DA. Neurofibromin is a novel regulator of RAS-induced signals in primary vascular smooth muscle cells. Hum Mol Genet 2006; 15:1921-30. [PMID: 16644864 DOI: 10.1093/hmg/ddl114] [Citation(s) in RCA: 59] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
Neurofibromatosis type I (NF1) is a genetic disorder caused by mutations in the NF1 tumor suppressor gene. Neurofibromin is encoded by NF1 and functions as a negative regulator of Ras activity. NF1 patients develop renal artery stenosis and arterial occlusions resulting in cerebral and visceral infarcts. Further, NF1 patients develop vascular neurofibromas where tumor vessels are invested in a dense pericyte sheath. Although it is well established that aberrations in Ras signaling lead to human malignancies, emerging data generated in genetically engineered mouse models now implicate perturbations in the Ras signaling axis in vascular smooth muscular cells (VSMCs) as central to the initiation and progression of neointimal hyperplasia and arterial stenosis. Despite these observations, the function of neurofibromin in regulating VSMC function and how Ras signals are terminated in VSMCs is virtually unknown. Utilizing VSMCs harvested from Nf1+/- mice and primary human neurofibromin-deficient VSMCs, we identify a discrete Ras effector pathway, which is tightly regulated by neurofibromin to limit VSMC proliferation and migration. Thus, these studies identify neurofibromin as a novel regulator of Ras activity in VSMCs and provide a framework for understanding cardiovascular disease in NF1 patients and a mechanism by which Ras signals are attenuated for maintaining VSMC homeostasis in blood vessel walls.
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Affiliation(s)
- Fang Li
- Department of Pediatrics, Herman B. Wells Center for Pediatric Research, Indiana University School of Medicine, 1044 W. Walnut Street, Indianapolis, IN 46202, USA
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Potenza N, Vecchione C, Notte A, De Rienzo A, Rosica A, Bauer L, Affuso A, De Felice M, Russo T, Poulet R, Cifelli G, De Vita G, Lembo G, Di Lauro R. Replacement of K-Ras with H-Ras supports normal embryonic development despite inducing cardiovascular pathology in adult mice. EMBO Rep 2005; 6:432-7. [PMID: 15864294 PMCID: PMC1299307 DOI: 10.1038/sj.embor.7400397] [Citation(s) in RCA: 102] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/17/2005] [Revised: 03/21/2005] [Accepted: 03/22/2005] [Indexed: 12/30/2022] Open
Abstract
Ras proteins are highly related GTPases that have key roles in regulating growth, differentiation and tumorigenesis. Gene-targeting experiments have shown that, out of the three mammalian ras genes, only K-ras is essential for normal mouse embryogenesis, and that mice deprived of H-ras and/or N-ras show no major phenotype. We generated mice (HrasKI) in which the K-ras gene had been modified to encode H-Ras protein. HrasKI mice produce undetectable amounts of K-Ras but-in contrast to mice homozygous for a null K-ras allele-they are born at the expected mendelian frequency, indicating that H-Ras can be substituted for K-Ras in embryonic development. However, adult HrasKI mice show dilated cardiomyopathy associated with arterial hypertension. Our results show that K-Ras can be replaced by H-Ras in its essential function in embryogenesis, and indicate that K-Ras has a unique role in cardiovascular homeostasis.
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Affiliation(s)
- Nicoletta Potenza
- Stazione Zoologica ‘A Dohrn', Laboratory of Animal Genetics, Villa Comunale, 1, 80121 Napoli, Italy
| | - Carmine Vecchione
- Department of Angiocardioneurology, IRCCS ‘Neuromed', 86077 Pozzilli (IS), Italy
| | - Antonella Notte
- Department of Angiocardioneurology, IRCCS ‘Neuromed', 86077 Pozzilli (IS), Italy
| | - Assunta De Rienzo
- BioGeM, c/o CEINGE Biotecnologie Avanzate, via Comunale Margherita 482, 80145 Napoli, Italy
| | - Annamaria Rosica
- BioGeM, c/o CEINGE Biotecnologie Avanzate, via Comunale Margherita 482, 80145 Napoli, Italy
| | - Lisa Bauer
- BioGeM, c/o CEINGE Biotecnologie Avanzate, via Comunale Margherita 482, 80145 Napoli, Italy
| | - Andrea Affuso
- BioGeM, c/o CEINGE Biotecnologie Avanzate, via Comunale Margherita 482, 80145 Napoli, Italy
| | - Mario De Felice
- Stazione Zoologica ‘A Dohrn', Laboratory of Animal Genetics, Villa Comunale, 1, 80121 Napoli, Italy
- BioGeM, c/o CEINGE Biotecnologie Avanzate, via Comunale Margherita 482, 80145 Napoli, Italy
| | - Tommaso Russo
- CEINGE Biotecnologie Avanzate, via Comunale Margherita 482, 80145 Napoli, Italy
| | - Roberta Poulet
- Department of Angiocardioneurology, IRCCS ‘Neuromed', 86077 Pozzilli (IS), Italy
| | - Giuseppe Cifelli
- Department of Angiocardioneurology, IRCCS ‘Neuromed', 86077 Pozzilli (IS), Italy
| | - Gabriella De Vita
- BioGeM, c/o CEINGE Biotecnologie Avanzate, via Comunale Margherita 482, 80145 Napoli, Italy
| | - Giuseppe Lembo
- Department of Angiocardioneurology, IRCCS ‘Neuromed', 86077 Pozzilli (IS), Italy
| | - Roberto Di Lauro
- Stazione Zoologica ‘A Dohrn', Laboratory of Animal Genetics, Villa Comunale, 1, 80121 Napoli, Italy
- BioGeM, c/o CEINGE Biotecnologie Avanzate, via Comunale Margherita 482, 80145 Napoli, Italy
- Tel: +39 081 3722865; Fax: +39 081 3722802; E-mail:
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