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Diesel exhaust particles induce human umbilical vein endothelial cells apoptosis by accumulation of autophagosomes and caspase-8 activation. Sci Rep 2022; 12:16492. [PMID: 36192481 PMCID: PMC9529885 DOI: 10.1038/s41598-022-21044-3] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/24/2022] [Accepted: 09/22/2022] [Indexed: 11/13/2022] Open
Abstract
Diesel exhaust particles (DEP) are risk factors for endothelial cells (ECs) dysfunction. However, the mechanism by which DEP induce ECs apoptosis remains unclear. Here, we investigated how DEP induce death of human umbilical vein ECs (HUVECs), with a focus on the autophagy-mediated apoptotic pathway. DEP induced dose-dependent HUVECs death and exposure to the IC50 concentration of DEP (70 µg/ml) led to apoptosis. DEP phosphorylated Beclin-1 (Ser93) and increased protein levels of p62 and LC3BII and the number of LC3B puncta, indicating autophagy initiation. DEP increased expression of pro- and mature forms of cathepsin D, which increases lysosomal activity. However, DEP suppressed expression of the soluble N-ethylmaleimide-sensitive factor attachment protein receptor proteins (STX17, VAMP8, SNAP29, YKT6, and STX7) to inhibit autolysosome formation, resulting in accumulation of autophagosomes. LC3B, p62, and caspase-8 form a tertiary complex in accumulated autophagosomes, which is known to serve as a platform for caspase-8 activation. Indeed, DEP activates caspase-8 and pretreatment with a caspase-8 inhibitor suppressed DEP-induced apoptosis. Furthermore, depletion of p62 decreased caspase-8 and caspase-3 activation and inhibited the DEP-induced apoptosis. Taken together, these findings demonstrated that DEP induced HUVECs apoptosis by inhibiting autophagosome maturation and identified caspase-8 as a novel mediator of DEP-induced ECs apoptosis.
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2
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Cao YJ, Li JY, Wang PX, Lin ZR, Yu WJ, Zhang JG, Lu J, Liu PQ. PKC-ζ Aggravates Doxorubicin-Induced Cardiotoxicity by Inhibiting Wnt/β-Catenin Signaling. Front Pharmacol 2022; 13:798436. [PMID: 35237161 PMCID: PMC8883055 DOI: 10.3389/fphar.2022.798436] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/20/2021] [Accepted: 01/03/2022] [Indexed: 11/25/2022] Open
Abstract
Doxorubicin (Dox) is a chemotherapeutic drug used to treat a wide range of cancers, but its clinical application is limited due to its cardiotoxicity. Protein kinase C-ζ (PKC-ζ) is a serine/threonine kinase belonging to atypical protein kinase C (PKC) subfamily, and is activated by its phosphorylation. We and others have reported that PKC-ζ induced cardiac hypertrophy by activating the inflammatory signaling pathway. This study focused on whether PKC-ζ played an important role in Dox-induced cardiotoxicity. We found that PKC-ζ phosphorylation was increased by Dox treatment in vivo and in vitro. PKC-ζ overexpression exacerbated Dox-induced cardiotoxicity. Conversely, knockdown of PKC-ζ by siRNA relieved Dox-induced cardiotoxicity. Similar results were observed when PKC-ζ enzyme activity was inhibited by its pseudosubstrate inhibitor, Myristoylated. PKC-ζ interacted with β-catenin and inhibited Wnt/β-catenin signaling pathway. Activation of Wnt/β-catenin signaling by LiCl protected against Dox-induced cardiotoxicity. The Wnt/β-catenin inhibitor XAV-939 aggravated Dox-caused decline of β-catenin and cardiomyocyte apoptosis and mitochondrial damage. Moreover, activation of Wnt/β-catenin suppressed aggravation of Dox-induced cardiotoxicity due to PKC-ζ overexpression. Taken together, our study revealed that inhibition of PKC-ζ activity was a potential cardioprotective approach to preventing Dox-induced cardiac injury.
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Affiliation(s)
- Yan-Jun Cao
- National and Local United Engineering Lab of Druggability and New Drugs Evaluation, School of Pharmaceutical Sciences, Sun Yat-sen University, Guangzhou, China
| | - Jing-Yan Li
- National and Local United Engineering Lab of Druggability and New Drugs Evaluation, School of Pharmaceutical Sciences, Sun Yat-sen University, Guangzhou, China
- School of Pharmaceutical Science, International Institute for Translational Chinese Medicine, Guangzhou University of Chinese Medicine, Guangzhou, China
| | - Pan-Xia Wang
- National and Local United Engineering Lab of Druggability and New Drugs Evaluation, School of Pharmaceutical Sciences, Sun Yat-sen University, Guangzhou, China
| | - Zhi-Rong Lin
- National and Local United Engineering Lab of Druggability and New Drugs Evaluation, School of Pharmaceutical Sciences, Sun Yat-sen University, Guangzhou, China
| | - Wen-Jing Yu
- National and Local United Engineering Lab of Druggability and New Drugs Evaluation, School of Pharmaceutical Sciences, Sun Yat-sen University, Guangzhou, China
| | - Ji-Guo Zhang
- School of Pharmaceutical Sciences, Shandong Academy of Medical Sciences, Shandong First Medical University, Taian, China
- *Correspondence: Ji-Guo Zhang, ; Jing Lu, ; Pei-Qing Liu,
| | - Jing Lu
- National and Local United Engineering Lab of Druggability and New Drugs Evaluation, School of Pharmaceutical Sciences, Sun Yat-sen University, Guangzhou, China
- *Correspondence: Ji-Guo Zhang, ; Jing Lu, ; Pei-Qing Liu,
| | - Pei-Qing Liu
- National and Local United Engineering Lab of Druggability and New Drugs Evaluation, School of Pharmaceutical Sciences, Sun Yat-sen University, Guangzhou, China
- School of Pharmaceutical Sciences, Shandong Academy of Medical Sciences, Shandong First Medical University, Taian, China
- *Correspondence: Ji-Guo Zhang, ; Jing Lu, ; Pei-Qing Liu,
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3
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Chen X, Hu C, Fan X, Wang Y, Li Q, Su YQ, Zhang DM, Yang Q, Passerini AG, Sun C. mTOR Inhibition Promotes Pneumonitis Through Inducing Endothelial Contraction and Hyperpermeability. Am J Respir Cell Mol Biol 2021; 65:646-657. [PMID: 34251297 DOI: 10.1165/rcmb.2020-0390oc] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022] Open
Abstract
Compromised endothelial (EC) barrier function is a hallmark of inflammatory diseases. Mammalian target of rapamycin (mTOR) inhibitors, widely applied as clinical therapies, cause pneumonitis through mechanisms not yet fully understood. This study aimed to elucidate the EC mechanisms underlying the pathogenesis of pneumonitis caused by mTOR inhibition (mTORi). Mice with EC-specific deletion of mTOR complex components (Mtor, Rptor or Rictor) were administered LPS to induce pulmonary injury. Cultured EC were treated with pharmacological inhibitors, small interfering RNA or overexpression-plasmids. EC barrier function was evaluated in vivo with Evan's blue assay and in vitro by measurement of transendothelial electrical resistance and albumin flux. mTORi increased basal and TNFα-induced EC permeability, which was caused by myosin light chain (MLC) phosphorylation-dependent cell contraction. Inactivation of mTOR kinase activity by mTORi triggered PKCδ/p38/NF-κB signaling that significantly upregulated TNFα-induced MLC kinase (MLCK) expression, while Raptor promoted the phosphorylation of PKCα/MYPT1 independent of its interaction with mTOR, leading to suppression of MLC phosphatase (MLCP) activity. EC-specific deficiency in mTOR, Raptor or Rictor aggravated lung inflammation in LPS-treated mice. These findings reveal that mTORi induces PKC-dependent endothelial MLC phosphorylation, contraction and hyperpermeability that promote pneumonitis.
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Affiliation(s)
- Xiaolin Chen
- Nanjing Medical University Collaborative Innovation Center for Cardiovascular Disease Translational Medicine, 540955, Key Laboratory of Targeted Intervention of Cardiovascular Disease, Nanjing, China.,2Key laboratory of Human Functional Genomics of Jiangsu Province, Nanjing, China
| | - Chengxiu Hu
- Nanjing Medical University Collaborative Innovation Center for Cardiovascular Disease Translational Medicine, 540955, Key Laboratory of Targeted Intervention of Cardiovascular Disease, Nanjing, China.,Key laboratory of Human Functional Genomics of Jiangsu Province, Nanjing, China
| | - Xing Fan
- Nanjing Medical University Collaborative Innovation Center for Cardiovascular Disease Translational Medicine, 540955, Key Laboratory of Targeted Intervention of Cardiovascular Disease, Nanjing, China.,Key laboratory of Human Functional Genomics of Jiangsu Province, Nanjing, China
| | - Yiying Wang
- Nanjing Medical University Collaborative Innovation Center for Cardiovascular Disease Translational Medicine, 540955, Key Laboratory of Targeted Intervention of Cardiovascular Disease, Nanjing, China.,Key laboratory of Human Functional Genomics of Jiangsu Province, Nanjing, China
| | - Qiannan Li
- Nanjing Medical University Collaborative Innovation Center for Cardiovascular Disease Translational Medicine, 540955, Key Laboratory of Targeted Intervention of Cardiovascular Disease, Nanjing, China.,Key laboratory of Human Functional Genomics of Jiangsu Province, Nanjing, China
| | - You-Qiang Su
- Nanjing Medical University, 12461, State Key Laboratory of Reproductive Medicine, Nanjing, China
| | - Dai-Min Zhang
- Nanjing First Hospital, Nanjing Medical University, Department of Cardiology, Nanjing, China
| | - QianLu Yang
- Nanjing Medical University Collaborative Innovation Center for Cardiovascular Disease Translational Medicine, 540955, Key Laboratory of Targeted Intervention of Cardiovascular Disease, Nanjing, China.,Key laboratory of Human Functional Genomics of Jiangsu Province, Nanjing, China
| | - Anthony G Passerini
- University of California Davis, 8789, Department of Biomedical Engineering, Davis, California, United States
| | - ChongXiu Sun
- Nanjing Medical University, 12461, Nanjing, China;
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Long X, You G, Wu Q, Zhou Y, Xiao Y, Yu F, Deng S, Mo R, Song F, Huang J, Tian M. HomeoboxC6 affects the apoptosis of human vascular endothelial cells and is involved in atherosclerosis. J Cell Physiol 2021; 236:1913-1925. [PMID: 32740941 DOI: 10.1002/jcp.29974] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/10/2020] [Revised: 06/23/2020] [Accepted: 07/16/2020] [Indexed: 12/18/2022]
Abstract
Apoptosis of vascular endothelial cells (VECs) is highly important in the occurrence and development of atherosclerosis (AS). HomeboxC6 (HOXC6) is expressed in higher levels in multiple malignant tissues, and it influences the malignant biological behavior of the cancer cells. However, the effects of HOXC6 on AS and the apoptosis of VECs have not been fully elucidated. In this study, we demonstrated that HOXC6 expression was increased in aortic wall of AS rats and peripheral blood monocytes of patients with coronary heart disease. Furthermore, it was uncovered that BAX expression was upregulated, while BCL-2 expression was downregulated in the aortic wall of AS rats. The apoptosis of human VECs (HVECs) cultured normally or treated with oxidized low-density lipoprotein in vitro was decreased after transfection with HOXC6-siRNA. Moreover, the results of Western blot analysis unveiled that the expressions of proapoptotic proteins, such as BAX, caspase-3, cleaved-caspase-3, and caspase-9 were reduced, while the expression of antiapoptotic protein, BCL-2, was elevated. Meanwhile, mRNA and protein expressions of phospholipase C beta (PLCβ) were decreased, the phosphorylation levels of protein kinase C zeta (PKCζ) and nuclear transcription factor-κB-p65 (NF-κBp65) and the membrane translocation of PKCζ were reduced as well. Besides, the expression of interleukin-18 (IL-18) protein was downregulated. However, after overexpression of HOXC6, the opposite trends of the abovementioned indices were observed. Furthermore, the inhibition of apoptosis induced by HOXC6-siRNA was reversed by lysophosphatidylcholine, an activator of PKCζ. Taken together, our results indicated that HOXC6 can promote the apoptosis of HVECs and may be involved in the occurrence and development of AS, which may be partially associated with the activation of PLCβ/PKCζ/NF-κBp65/IL-18 signaling pathway.
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Affiliation(s)
- Xiangshu Long
- Medical College, Guizhou University, Guiyang, Guizhou, China
- Department of Cardiology, Guizhou Provincial People's Hospital, Guiyang, Guizhou, China
- People's Hospital of Guizhou University, Guiyang, Guizhou, China
| | - Ganhua You
- Department of Cardiology, Guizhou Provincial People's Hospital, Guiyang, Guizhou, China
- People's Hospital of Guizhou University, Guiyang, Guizhou, China
| | - Qiang Wu
- Department of Cardiology, Guizhou Provincial People's Hospital, Guiyang, Guizhou, China
- People's Hospital of Guizhou University, Guiyang, Guizhou, China
| | - Yu Zhou
- Medical College, Guizhou University, Guiyang, Guizhou, China
- Department of Cardiology, Guizhou Provincial People's Hospital, Guiyang, Guizhou, China
| | - Yan Xiao
- Department of Cardiology, Guizhou Provincial People's Hospital, Guiyang, Guizhou, China
| | - Fuxun Yu
- Department of Research Laboratory Center, Guizhou Provincial People's Hospital, Guiyang, Guizhou, China
| | - Shiyan Deng
- Department of Cardiology, Guizhou Provincial People's Hospital, Guiyang, Guizhou, China
| | - Rui Mo
- Department of Cardiology, Guizhou Provincial People's Hospital, Guiyang, Guizhou, China
| | - Fang Song
- Department of Cardiology, Guizhou Provincial People's Hospital, Guiyang, Guizhou, China
| | - Jing Huang
- Department of Cardiology, Guizhou Provincial People's Hospital, Guiyang, Guizhou, China
| | - Maobo Tian
- Department of Cardiology, Guizhou Provincial People's Hospital, Guiyang, Guizhou, China
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5
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Kim GY, Lim HJ, Kim WH, Park HY. Coronin 1B regulates the TNFα-induced apoptosis of HUVECs by mediating the interaction between TRADD and FADD. Biochem Biophys Res Commun 2020; 526:999-1004. [DOI: 10.1016/j.bbrc.2020.03.096] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/02/2020] [Accepted: 03/18/2020] [Indexed: 01/11/2023]
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6
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Marrocco V, Bogomolovas J, Ehler E, Dos Remedios CG, Yu J, Gao C, Lange S. PKC and PKN in heart disease. J Mol Cell Cardiol 2019; 128:212-226. [PMID: 30742812 PMCID: PMC6408329 DOI: 10.1016/j.yjmcc.2019.01.029] [Citation(s) in RCA: 41] [Impact Index Per Article: 8.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/03/2018] [Revised: 01/30/2019] [Accepted: 01/31/2019] [Indexed: 12/22/2022]
Abstract
The protein kinase C (PKC) and closely related protein kinase N (PKN) families of serine/threonine protein kinases play crucial cellular roles. Both kinases belong to the AGC subfamily of protein kinases that also include the cAMP dependent protein kinase (PKA), protein kinase B (PKB/AKT), protein kinase G (PKG) and the ribosomal protein S6 kinase (S6K). Involvement of PKC family members in heart disease has been well documented over the years, as their activity and levels are mis-regulated in several pathological heart conditions, such as ischemia, diabetic cardiomyopathy, as well as hypertrophic or dilated cardiomyopathy. This review focuses on the regulation of PKCs and PKNs in different pathological heart conditions and on the influences that PKC/PKN activation has on several physiological processes. In addition, we discuss mechanisms by which PKCs and the closely related PKNs are activated and turned-off in hearts, how they regulate cardiac specific downstream targets and pathways, and how their inhibition by small molecules is explored as new therapeutic target to treat cardiomyopathies and heart failure.
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Affiliation(s)
- Valeria Marrocco
- Division of Cardiology, School of Medicine, University of California-San Diego, La Jolla, USA
| | - Julius Bogomolovas
- Division of Cardiology, School of Medicine, University of California-San Diego, La Jolla, USA; Department of Cognitive and Clinical Neuroscience, Central Institute of Mental Health, Medical Faculty Mannheim, Heidelberg University, Mannheim, Germany
| | - Elisabeth Ehler
- Randall Centre for Cell and Molecular Biophysics, School of Basic and Medical Biosciences, School of Cardiovascular Medicine and Sciences, British Heart Foundation Research Excellence Centre, King's College London, New Hunt's House, Guy's Campus, London SE1 1UL, UK
| | | | - Jiayu Yu
- Key Laboratory of Cell Differentiation and Apoptosis of Chinese Ministry of Education, Department of Pathophysiology, Shanghai Jiao Tong University School of Medicine, Shanghai, China
| | - Chen Gao
- Division of Molecular Medicine, Department of Anesthesiology, David Geffen School of Medicine at UCLA, University of California-Los Angeles, Los Angeles, USA.
| | - Stephan Lange
- Division of Cardiology, School of Medicine, University of California-San Diego, La Jolla, USA; University of Gothenburg, Wallenberg Laboratory, Department of Molecular and Clinical Medicine, Institute of Medicine, Gothenburg, Sweden.
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7
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Kearney CJ, Vervoort SJ, Hogg SJ, Ramsbottom KM, Freeman AJ, Lalaoui N, Pijpers L, Michie J, Brown KK, Knight DA, Sutton V, Beavis PA, Voskoboinik I, Darcy PK, Silke J, Trapani JA, Johnstone RW, Oliaro J. Tumor immune evasion arises through loss of TNF sensitivity. Sci Immunol 2018; 3:3/23/eaar3451. [DOI: 10.1126/sciimmunol.aar3451] [Citation(s) in RCA: 165] [Impact Index Per Article: 27.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/27/2017] [Accepted: 03/29/2018] [Indexed: 12/11/2022]
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8
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Islam MA, Sooro MA, Zhang P. Autophagic Regulation of p62 is Critical for Cancer Therapy. Int J Mol Sci 2018; 19:ijms19051405. [PMID: 29738493 PMCID: PMC5983640 DOI: 10.3390/ijms19051405] [Citation(s) in RCA: 152] [Impact Index Per Article: 25.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/30/2018] [Revised: 04/30/2018] [Accepted: 05/03/2018] [Indexed: 12/13/2022] Open
Abstract
Sequestosome1 (p62/SQSTM 1) is a multidomain protein that interacts with the autophagy machinery as a key adaptor of target cargo. It interacts with phagophores through the LC3-interacting (LIR) domain and with the ubiquitinated protein aggregates through the ubiquitin-associated domain (UBA) domain. It sequesters the target cargo into inclusion bodies by its PB1 domain. This protein is further the central hub that interacts with several key signaling proteins. Emerging evidence implicates p62 in the induction of multiple cellular oncogenic transformations. Indeed, p62 upregulation and/or reduced degradation have been implicated in tumor formation, cancer promotion as well as in resistance to therapy. It has been established that the process of autophagy regulates the levels of p62. Autophagy-dependent apoptotic activity of p62 is recently being reported. It is evident that p62 plays a critical role in both autophagy and apoptosis. Therefore in this review we discuss the role of p62 in autophagy, apoptosis and cancer through its different domains and outline the importance of modulating cellular levels of p62 in cancer therapeutics.
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Affiliation(s)
- Md Ariful Islam
- Jiangsu Key Laboratory of New Drug Screening & Jiangsu Center for Pharmacodynamics Research and Evaluation, China Pharmaceutical University, Nanjing 210009, China.
| | - Mopa Alina Sooro
- Jiangsu Key Laboratory of New Drug Screening & Jiangsu Center for Pharmacodynamics Research and Evaluation, China Pharmaceutical University, Nanjing 210009, China.
| | - Pinghu Zhang
- Institute of Translational Medicine & Jiangsu Key Laboratory of Integrated Traditional Chinese and Western Medicine for Prevention and Treatment of Senile Diseases, Medical College, Yangzhou University, Yangzhou 225001, China.
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9
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Kim GY, Lim HJ, Park HY. Binding of coronin 1B to TβRI negatively regulates the TGFβ1 signaling pathway. Biochem Biophys Res Commun 2017. [PMID: 28625921 DOI: 10.1016/j.bbrc.2017.06.080] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/19/2022]
Abstract
Coronin 1B is an actin-binding protein that regulates several actin-dependent cellular processes including migration and endocytosis. However, the role of coronin 1B in the tumor growth factor (TGF)β signaling pathway is largely unknown. Here, we investigated whether coronin 1B affects the TGFβ signaling cascade and found that coronin 1B negatively regulates the TGFβ signaling pathway. Immunoprecipitation and glutathione-S-transferase-pulldown assays revealed that coronin 1B directly associated with TGFβ receptor I (TβRI). Overexpression of coronin 1B inhibited the TGFβ1-induced interaction between TβRI and Smad2/3 in plasmid-transfected HEK293T cells. Coronin 1B was basally bound to TβRI in vascular smooth muscle cells (VSMCs), but TGFβ1 stimulation did not affect their association, suggesting constitutive binding between coronin 1B and TβRI. Overexpression of coronin 1B suppressed TGFβ1-induced activation of a Smad-binding element-luciferase reporter construct and a plasminogen activator inhibitor (PAI)-1 promoter-luciferase reporter construct in HEK293T cells. By contrast, depletion of coronin 1B by siRNA transfection increased TGFβ1-induced Smad2/3 phosphorylation and PAI-1 expression in VSMCs. These results suggest that coronin 1B regulates the TGFβ1 signaling cascade by constitutively interacting with TβRI and inhibiting the binding of Smad2/3 to TβRI in response to TGFβ1 stimulation.
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Affiliation(s)
- Geun-Young Kim
- Division of Cardiovascular and Rare Disease, Center for Biomedical Sciences, Korea National Research Institute of Health, Cheongju, Republic of Korea; Jeju National Quarantine Station, Centers for Disease Control & Prevention, Jeju, Republic of Korea
| | - Hyun-Joung Lim
- Division of Cardiovascular and Rare Disease, Center for Biomedical Sciences, Korea National Research Institute of Health, Cheongju, Republic of Korea
| | - Hyun-Young Park
- Division of Cardiovascular and Rare Disease, Center for Biomedical Sciences, Korea National Research Institute of Health, Cheongju, Republic of Korea.
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10
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Evans TD, Sergin I, Zhang X, Razani B. Target acquired: Selective autophagy in cardiometabolic disease. Sci Signal 2017; 10:eaag2298. [PMID: 28246200 PMCID: PMC5451512 DOI: 10.1126/scisignal.aag2298] [Citation(s) in RCA: 47] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
The accumulation of damaged or excess proteins and organelles is a defining feature of metabolic disease in nearly every tissue. Thus, a central challenge in maintaining metabolic homeostasis is the identification, sequestration, and degradation of these cellular components, including protein aggregates, mitochondria, peroxisomes, inflammasomes, and lipid droplets. A primary route through which this challenge is met is selective autophagy, the targeting of specific cellular cargo for autophagic compartmentalization and lysosomal degradation. In addition to its roles in degradation, selective autophagy is emerging as an integral component of inflammatory and metabolic signaling cascades. In this Review, we focus on emerging evidence and key questions about the role of selective autophagy in the cell biology and pathophysiology of metabolic diseases such as obesity, diabetes, atherosclerosis, and steatohepatitis. Essential players in these processes are the selective autophagy receptors, defined broadly as adapter proteins that both recognize cargo and target it to the autophagosome. Additional domains within these receptors may allow integration of information about autophagic flux with critical regulators of cellular metabolism and inflammation. Details regarding the precise receptors involved, such as p62 and NBR1, and their predominant interacting partners are just beginning to be defined. Overall, we anticipate that the continued study of selective autophagy will prove to be informative in understanding the pathogenesis of metabolic diseases and to provide previously unrecognized therapeutic targets.
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Affiliation(s)
- Trent D Evans
- Cardiovascular Division, Department of Medicine, Washington University School of Medicine, St. Louis, MO 63110, USA
| | - Ismail Sergin
- Cardiovascular Division, Department of Medicine, Washington University School of Medicine, St. Louis, MO 63110, USA
| | - Xiangyu Zhang
- Cardiovascular Division, Department of Medicine, Washington University School of Medicine, St. Louis, MO 63110, USA
| | - Babak Razani
- Cardiovascular Division, Department of Medicine, Washington University School of Medicine, St. Louis, MO 63110, USA.
- Department of Pathology and Immunology, Washington University School of Medicine, St. Louis, MO 63110, USA
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11
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Flow signaling and atherosclerosis. Cell Mol Life Sci 2016; 74:1835-1858. [PMID: 28039525 PMCID: PMC5391278 DOI: 10.1007/s00018-016-2442-4] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/29/2016] [Revised: 12/12/2016] [Accepted: 12/15/2016] [Indexed: 12/26/2022]
Abstract
Atherosclerosis rarely develops in the region of arteries exposed to undisturbed flow (u-flow, unidirectional flow). Instead, atherogenesis occurs in the area exposed to disturbed flow (d-flow, multidirectional flow). Based on these general pathohistological observations, u-flow is considered to be athero-protective, while d-flow is atherogenic. The fact that u-flow and d-flow induce such clearly different biological responses in the wall of large arteries indicates that these two types of flow activate each distinct intracellular signaling cascade in vascular endothelial cells (ECs), which are directly exposed to blood flow. The ability of ECs to differentially respond to the two types of flow provides an opportunity to identify molecular events that lead to endothelial dysfunction and atherosclerosis. In this review, we will focus on various molecular events, which are differentially regulated by these two flow types. We will discuss how various kinases, ER stress, inflammasome, SUMOylation, and DNA methylation play roles in the differential flow response, endothelial dysfunction, and atherosclerosis. We will also discuss the interplay among the molecular events and how they coordinately regulate flow-dependent signaling and cellular responses. It is hoped that clear understanding of the way how the two flow types beget each unique phenotype in ECs will lead us to possible points of intervention against endothelial dysfunction and cardiovascular diseases.
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12
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Xi G, Shen X, Rosen CJ, Clemmons DR. IRS-1 Functions as a Molecular Scaffold to Coordinate IGF-I/IGFBP-2 Signaling During Osteoblast Differentiation. J Bone Miner Res 2016; 31:1300-14. [PMID: 26773517 PMCID: PMC5228590 DOI: 10.1002/jbmr.2791] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/18/2015] [Revised: 01/12/2016] [Accepted: 01/15/2016] [Indexed: 12/29/2022]
Abstract
Insulin like growth factor I (IGF-I) and insulin like growth factor binding protein-2 (IGFBP-2) function coordinately to stimulate AKT and osteoblast differentiation. IGFBP-2 binding to receptor protein tyrosine phosphatase β (RPTPβ) stimulates polymerization and inactivation of phosphatase activity. Because phosphatase and tensin homolog (PTEN) is the primary target of RPTPβ, this leads to enhanced PTEN tyrosine phosphorylation and inactivation. However RPTPβ inactivation also requires IGF-I receptor activation. The current studies were undertaken to determine the mechanism by which IGF-I mediates changes in RPTPβ function in osteoblasts. IGFBP-2/IGF-I stimulated vimentin binding to RPTPβ and this was required for RPTPβ polymerization. Vimentin serine phosphorylation mediated its binding to RPTPβ and PKCζ was identified as the kinase that phosphorylated vimentin. To determine the mechanism underlying IGF-I stimulation of PKCζ-mediated vimentin phosphorylation, we focused on insulin receptor substrate-1 (IRS-1). IGF-I stimulated IRS-1 phosphorylation and recruitment of PKCζ and vimentin to phospho-IRS-1. IRS-1 immunoprecipitates containing PKCζ and vimentin were used to confirm that activated PKCζ directly phosphorylated vimentin. PKCζ does not contain a SH-2 domain that is required to bind to phospho-IRS-1. To determine the mechanism of PKCζ recruitment we analyzed the role of p62 (a PKCζ binding protein) that contains a SH2 domain. Exposure to differentiation medium plus IGF-I stimulated PKCζ/p62 association. Subsequent analysis showed the p62/PKCζ complex was co-recruited to IRS-1. Peptides that disrupted p62/PKCζ or p62/IRS-1 inhibited IGF-I/IGFBP-2 stimulated PKCζ activation, vimentin phosphorylation, PTEN tyrosine phosphorylation, AKT activation, and osteoblast differentiation. The importance of these signaling events for differentiation was confirmed in primary mouse calvarial osteoblasts. These results demonstrate the cooperative interaction between RPTPβ and the IGF-I receptor leading to a coordinated series of signaling events that are required for osteoblast differentiation. Our findings emphasize the important role IRS-1 plays in modulating these signaling events and confirm its essential role in facilitating osteoblast differentiation. © 2016 American Society for Bone and Mineral Research.
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Affiliation(s)
- Gang Xi
- Department of Medicine, University of North Carolina, School of Medicine, Chapel Hill, NC, USA
| | - Xinchun Shen
- College of Food Science and Engineering, Nanjing University of Finance and Economics, Nanjing, China
| | | | - David R Clemmons
- Department of Medicine, University of North Carolina, School of Medicine, Chapel Hill, NC, USA
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13
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Kim GY, Kim H, Lim HJ, Park HY. Coronin 1A depletion protects endothelial cells from TNFα-induced apoptosis by modulating p38β expression and activation. Cell Signal 2015; 27:1688-93. [DOI: 10.1016/j.cellsig.2015.04.012] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/29/2015] [Revised: 04/23/2015] [Accepted: 04/25/2015] [Indexed: 11/15/2022]
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14
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Xi G, Shen X, Wai C, Vilas CK, Clemmons DR. Hyperglycemia stimulates p62/PKCζ interaction, which mediates NF-κB activation, increased Nox4 expression, and inflammatory cytokine activation in vascular smooth muscle. FASEB J 2015; 29:4772-82. [PMID: 26231202 DOI: 10.1096/fj.15-275453] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/05/2015] [Accepted: 07/20/2015] [Indexed: 12/20/2022]
Abstract
Hyperglycemia leads to vascular smooth muscle cell (VSMC) dedifferentiation and enhances responses to IGF-I. Prior studies showed that hyperglycemia stimulated NADPH oxidase 4 (Nox4) synthesis, and IGF-I facilitated its recruitment to a signaling complex where it oxidized src, leading to AKT and MAPK activation. To determine the mechanism that led to these changes, we analyzed the roles of p62 (sequestrosome1) and PKCζ. Hyperglycemia induced a 4.9 ± 1.0-fold increase in p62/PKCζ association, and disruption of PKCζ/p62 using a peptide inhibitor or p62 knockdown reduced PKCζ activation (78 ± 6%). 3-Phosphoinoside-dependent protein kinase 1 was also recruited to the p62 complex and directly phosphorylated PKCζ, leading to its activation (3.1 ± 0.4-fold). Subsequently, activated PKCζ phosphorylated p65 rel, which led to increased Nox4 synthesis. Studies in diabetic mice confirmed these findings (6.0 ± 0.4-fold increase in p62/PKCζ) and their disruption of attenuated Nox4 synthesis (76 ± 9% reduction). PKCζ/p62 activation stimulated inflammatory cytokine production and enhanced IGF-I-stimulated VSMC proliferation. These results define the molecular mechanism by which PKCζ is activated in response to hyperglycemia and suggest that this could be a mechanism by which other stimuli such as cytokines or metabolic stress function to stimulate NF-κB activation, thereby altering VSMC sensitivity to IGF-I.
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Affiliation(s)
- Gang Xi
- *Department of Medicine, University of North Carolina, School of Medicine, Chapel Hill, North Carolina, USA; and College of Food Science and Engineering, Nanjing University of Finance and Economics, Nanjing, China
| | - Xinchun Shen
- *Department of Medicine, University of North Carolina, School of Medicine, Chapel Hill, North Carolina, USA; and College of Food Science and Engineering, Nanjing University of Finance and Economics, Nanjing, China
| | - Christine Wai
- *Department of Medicine, University of North Carolina, School of Medicine, Chapel Hill, North Carolina, USA; and College of Food Science and Engineering, Nanjing University of Finance and Economics, Nanjing, China
| | - Caroline K Vilas
- *Department of Medicine, University of North Carolina, School of Medicine, Chapel Hill, North Carolina, USA; and College of Food Science and Engineering, Nanjing University of Finance and Economics, Nanjing, China
| | - David R Clemmons
- *Department of Medicine, University of North Carolina, School of Medicine, Chapel Hill, North Carolina, USA; and College of Food Science and Engineering, Nanjing University of Finance and Economics, Nanjing, China
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Abstract
The protein kinases C (PKCs) are a family of serine/threonine kinases involved in regulating multiple essential cellular processes such as survival, proliferation, and differentiation. Of particular interest is the novel, calcium-independent PKCθ which plays a central role in immune responses. PKCθ shares structural similarities with other PKC family members, mainly consisting of an N-terminal regulatory domain and a C-terminal catalytic domain tethered by a hinge region. This isozyme, however, is unique in that it translocates to the immunological synapse between a T cell and an antigen-presenting cell (APC) upon T cell receptor-peptide MHC recognition. Thereafter, PKCθ interacts physically and functionally with downstream effectors to mediate T cell activation and differentiation, subsequently leading to inflammation. PKCθ-specific perturbations have been identified in several diseases, most notably autoimmune disorders, and hence the modulation of its activity presents an attractive therapeutic intervention. To that end, many inhibitors of PKCs and PKCθ have been developed and tested in preclinical and clinical studies. And although selectivity remains a challenge, results are promising for the future development of effective PKCθ inhibitors that would greatly advance the treatment of several T-cell mediated diseases.
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Burke RM, Berk BC. The Role of PB1 Domain Proteins in Endothelial Cell Dysfunction and Disease. Antioxid Redox Signal 2015; 22:1243-56. [PMID: 25686626 DOI: 10.1089/ars.2014.6182] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
SIGNIFICANCE There are a limited number of proteins containing the Phox-Bem1 (PB1) protein interaction domain, and almost all of them play some role in endothelial cell (EC) function, health, and homeostasis. RECENT ADVANCES Most of these proteins have been shown to physically interact through PB1-PB1 binding and, as such, are linked together to form complexes that are responsive to hemodynamic force. These complexes range from redox regulation to inflammation to autophagy and back, and they employ multiple feedback mechanisms that are reliant on PB1 domain proteins. CRITICAL ISSUES Pathologic roles for PB1 domain-containing proteins have been demonstrated in multiple diseases, including vascular disease, cancer, liver disease, and myriad other concerns. Findings cited in this review show that dimerization of PB1 proteins exerts novel effects on EC function that may be important in multiple cardiovascular diseases, including atherosclerosis, thrombosis, inflammation, and hypertension. FUTURE DIRECTIONS As mechanistic understanding of the component pathways (redox regulation, cell polarity, inflammation, atheroprotection, and autophagy) is continually increasing, the larger picture of how these pathways interact with one another is evolving rapidly. We can now evaluate the PB1 domain proteins as a family in the context of multiple phenotypic readouts in EC function as well as evaluate them as drug targets against disease.
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Affiliation(s)
- Ryan M Burke
- Department of Medicine, Aab Cardiovascular Research Institute, University of Rochester Medical Center , Rochester, New York
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17
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Jaadane I, Chahory S, Leprêtre C, Omri B, Jonet L, Behar-Cohen F, Crisanti P, Torriglia A. The activation of the atypical PKC zeta in light-induced retinal degeneration and its involvement in L-DNase II control. J Cell Mol Med 2015; 19:1646-55. [PMID: 25781645 PMCID: PMC4511362 DOI: 10.1111/jcmm.12539] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/24/2014] [Accepted: 12/15/2014] [Indexed: 02/06/2023] Open
Abstract
Light-induced retinal degeneration is characterized by photoreceptor cell death. Many studies showed that photoreceptor demise is caspase-independent. In our laboratory we showed that leucocyte elastase inhibitor/LEI-derived DNase II (LEI/L-DNase II), a caspase-independent apoptotic pathway, is responsible for photoreceptor death. In this work, we investigated the activation of a pro-survival kinase, the protein kinase C (PKC) zeta. We show that light exposure induced PKC zeta activation. PKC zeta interacts with LEI/L-DNase II and controls its DNase activity by impairing its nuclear translocation. These results highlight the role of PKC zeta in retinal physiology and show that this kinase can control caspase-independent pathways.
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Affiliation(s)
- Imene Jaadane
- INSERM U1138, Centre de Recherches des Cordeliers, Université Paris Descartes, Université Pierre et Marie Curie, Paris, France
| | - Sabine Chahory
- ENVA, Ecole Nationale Vétérinaire d'Alfort, Maison Alfort, Paris, France
| | - Chloé Leprêtre
- INSERM U1138, Centre de Recherches des Cordeliers, Université Paris Descartes, Université Pierre et Marie Curie, Paris, France
| | - Boubaker Omri
- INSERM U1138, Centre de Recherches des Cordeliers, Université Paris Descartes, Université Pierre et Marie Curie, Paris, France
| | - Laurent Jonet
- INSERM U1138, Centre de Recherches des Cordeliers, Université Paris Descartes, Université Pierre et Marie Curie, Paris, France
| | - Francine Behar-Cohen
- INSERM U1138, Centre de Recherches des Cordeliers, Université Paris Descartes, Université Pierre et Marie Curie, Paris, France.,Hôpital Ophtalmique Jules-Gonin, Lausanne, Switzerland
| | - Patricia Crisanti
- INSERM U1138, Centre de Recherches des Cordeliers, Université Paris Descartes, Université Pierre et Marie Curie, Paris, France
| | - Alicia Torriglia
- INSERM U1138, Centre de Recherches des Cordeliers, Université Paris Descartes, Université Pierre et Marie Curie, Paris, France
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18
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Abstract
Atherosclerosis is a focal disease that develops preferentially where nonlaminar, disturbed blood flow occurs, such as branches, bifurcations, and curvatures of large arteries. Endothelial cells sense and respond differently to disturbed flow compared with steady laminar flow. Disturbed flow that occurs in so-called atheroprone areas activates proinflammatory and apoptotic signaling, and this results in endothelial dysfunction and leads to subsequent development of atherosclerosis. In contrast, steady laminar flow as atheroprotective flow promotes expression of many anti-inflammatory genes, such as Kruppel-like factor 2 and endothelial nitric oxide synthase and inhibits endothelial inflammation and athrogenesis. Here we will discuss that disturbed flow and steady laminar flow induce pro- and antiatherogenic events via flow type-specific mechanotransduction pathways. We will focus on 5 mechanosensitive pathways: mitogen-activated protein kinases/extracellular signal-regulated kinase 5/Kruppel-like factor 2 signaling, extracellular signal-regulated kinase/peroxisome proliferator-activated receptor signaling, and mechanosignaling pathways involving SUMOylation, protein kinase C-ζ, and p90 ribosomal S6 kinase. We think that clarifying regulation mechanisms between these 2 flow types will provide new insights into therapeutic approaches for the prevention and treatment of atherosclerosis.
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Affiliation(s)
- Jun-ichi Abe
- From the Aab Cardiovascular Research Institute, University of Rochester, NY.
| | - Bradford C Berk
- From the Aab Cardiovascular Research Institute, University of Rochester, NY.
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Abdel-Halim M, Diesel B, Kiemer AK, Abadi AH, Hartmann RW, Engel M. Discovery and optimization of 1,3,5-trisubstituted pyrazolines as potent and highly selective allosteric inhibitors of protein kinase C-ζ. J Med Chem 2014; 57:6513-30. [PMID: 25058929 DOI: 10.1021/jm500521n] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
Abstract
There is increasing evidence that the atypical protein kinase C, PKCζ, might be a therapeutic target in pulmonary and hepatic inflammatory diseases. However, targeting the highly conserved ATP-binding pocket in the catalytic domain held little promise to achieve selective inhibition. In the present study, we introduce 1,3,5-trisubstituted pyrazolines as potent and selective allosteric PKCζ inhibitors. The rigid scaffold offered many sites for modification, all acting as hot spots for improving activity, and gave rise to sharp structure-activity relationships. Targeting of PKCζ in cells was confirmed by reporter gene assay, transfection assays, and Western blotting. The strongly reduced cell-free and cellular activities toward a PIF-pocket mutant of PKCζ suggested that the inhibitors most likely bound to the PIF-pocket on the kinase catalytic domain. Thus, using a rigidification strategy and by establishing and optimizing multiple molecular interactions with the binding site, we were able to significantly improve the potency of the previously reported PKCζ inhibitors.
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Affiliation(s)
- Mohammad Abdel-Halim
- Pharmaceutical and Medicinal Chemistry, Saarland University , Campus C2.3, D-66123 Saarbrücken, Germany
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Soe NN, Sowden M, Baskaran P, Kim Y, Nigro P, Smolock EM, Berk BC. Acetylation of cyclophilin A is required for its secretion and vascular cell activation. Cardiovasc Res 2013; 101:444-53. [PMID: 24293519 DOI: 10.1093/cvr/cvt268] [Citation(s) in RCA: 50] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
AIMS Cyclophilin A (CyPA) is a pro-inflammatory mediator involved in oxidative stress-related cardiovascular diseases. It is secreted from vascular smooth muscle cell (VSMC) in response to reactive oxygen species (ROS) in a highly regulated manner. Extracellular CyPA activates VSMCs and endothelial cells (ECs) promoting inflammation, cell growth, and cell death. Recently, it was shown that acetylated CyPA (AcK-CyPA) affects its function. We investigated the role of acetylation of CyPA for its secretion and signalling in vascular cells. METHODS AND RESULTS We used angiotensin II (Ang II) to create sustained ROS and found significantly increased AcK-CyPA in VSMC. Site-directed mutagenesis showed that lysines K82 and K125 were the predominant CyPA residues acetylated in response to Ang II. Importantly, acetylation of K82 and K125 were required for Ang II-mediated CyPA secretion. ROS inhibitors, Tiron, and N-acetylcysteine inhibited Ang II-induced intracellular CyPA acetylation and also AcK-CyPA secretion. Using secreted CyPA from wild type and K82/125R mutants expressed in transduced VSMC or in vitro acetylated recombinant CyPA, we showed that extracellular AcK-CyPA significantly increased pERK1/2, matrix metalloproteinase-2 activation, and ROS production in VSMC compared with non-acetylated CyPA. Moreover, extracellular AcK-CyPA increased adhesion molecule expression (VCAM-1 and ICAM-1) in EC, which promoted monocyte adhesion. CONCLUSIONS ROS-dependent acetylation of CyPA is required for the generation of extracellular CyPA. Acetylated extracellular CyPA regulates VSMC and EC activation, suggesting that inhibition of acetylation of CyPA may prevent the pathogenesis of oxidative stress-related cardiovascular diseases.
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Affiliation(s)
- Nwe Nwe Soe
- Aab Cardiovascular Research Institute and Department of Medicine, University of Rochester School of Medicine and Dentistry, Box CVRI, 601 Elmwood Avenue, Rochester, NY 14642, USA
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Abstract
AIM To investigate whether sequestosome 1/p62 (p62), a key cargo adaptor protein involved in both the ubiquitin-proteasome system and the autophagy-lysosome system, could directly regulate autophagy in vitro. METHODS HEK 293 cells or HeLa cells were transfected with p62-expressing plasmids or siRNA targeting p62. The cells or the cell lysates were subsequently subjected to immunofluorescence assay, immunoprecipitation assay, or immunoblot analysis. In vitro pulldown assay was used to study the interaction of p62 with Bcl-2. RESULTS Overexpression of p62 significantly increased the basal level of autophagy in both HEK 293 cells and HeLa cells, whereas knockdown of p62 significantly decreased the basal level of autophagy. In vitro pulldown assay showed that p62 directly interacted with Bcl-2. It was observed in HeLa cells that p62 co-localized with Bcl-2. Furthermore, knockdown of p62 in HEK 293 cells significantly increased the amount of Beclin 1 that co-immunoprecipitated with Bcl-2. CONCLUSION p62 induces autophagy by disrupting the association between Bcl-2 and Beclin 1.
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22
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Jin M, Ande A, Kumar A, Kumar S. Regulation of cytochrome P450 2e1 expression by ethanol: role of oxidative stress-mediated pkc/jnk/sp1 pathway. Cell Death Dis 2013; 4:e554. [PMID: 23519123 PMCID: PMC3615729 DOI: 10.1038/cddis.2013.78] [Citation(s) in RCA: 117] [Impact Index Per Article: 10.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Abstract
CYP2E1 metabolizes ethanol leading to production of reactive oxygen species (ROS) and acetaldehyde, which are known to cause not only liver damage but also toxicity to other organs. However, the signaling pathways involved in CYP2E1 regulation by ethanol are not clear, especially in extra-hepatic cells. This study was designed to examine the role of CYP2E1 in ethanol-mediated oxidative stress and cytotoxicity, as well as signaling pathways by which ethanol regulates CYP2E1 in extra-hepatic cells. In this study, we used astrocytic and monocytic cell lines, because they are important cells in central nervous system . Our results showed that 100 mM ethanol significantly induced oxidative stress, apoptosis, and cell death at 24 h in the SVGA astrocytic cell line, which was rescued by a CYP2E1 selective inhibitor, diallyl sulfide (DAS), CYP2E1 siRNA, and antioxidants (vitamins C and E). Further, we showed that DAS and vitamin C abrogated ethanol-mediated (50 mℳ) induction of CYP2E1 at 6 h, as well as production of ROS at 2 h, suggesting the role of oxidative stress in ethanol-mediated induction of CYP2E1. We then investigated the role of the protein kinase C/c-Jun N-terminal kinase/specificity protein1 (PKC/JNK/SP1) pathway in oxidative stress-mediated CYP2E1 induction. Our results showed that staurosporine, a non-specific inhibitor of PKC, as well as specific PKCζ inhibitor and PKCζ siRNA, abolished ethanol-induced CYP2E1 expression. In addition, inhibitors of JNK (SP600125) and SP1 (mithramycin A) completely abrogated induction of CYP2E1 by ethanol in SVGA astrocytes. Subsequently, we showed that CYP2E1 is also responsible for ethanol-mediated oxidative stress and apoptotic cell death in U937 monocytic cell lines. Finally, our results showed that PKC/JNK/SP1 pathway is also involved in regulation of CYP2E1 in U937 cells. This study has clinical implications with respect to alcohol-associated neuroinflammatory toxicity among alcohol users.
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Affiliation(s)
- M Jin
- Division of Pharmacology and Toxicology, School of Pharmacy, University of Missouri-Kansas City, Kansas City, MO 64108, USA
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