1
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Zhang Q, Ding L, Li J, Liu K, Xia C, Chen S, Huang X, Pu Y, Song Y, Hu Q, Wang Y. Single-cell RNA sequencing of OSCC primary tumors and lymph nodes reveals distinct origin and phenotype of fibroblasts. Cancer Lett 2024; 600:217180. [PMID: 39154702 DOI: 10.1016/j.canlet.2024.217180] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/04/2024] [Revised: 07/02/2024] [Accepted: 08/09/2024] [Indexed: 08/20/2024]
Abstract
Desmoplasia in fibroblasts within metastatic lymph nodes (MLNs) serves as an indicator of extranodal extension (ENE), which led mortality in oral squamous cell carcinoma (OSCC). However, systematic studies on fibroblasts in MLNs are lacking. Therefore, this study characterized the differences in phenotype, function, and origin of fibroblasts between primary tumors (PTs) and lymph nodes (LNs) in OSCC. We generated single-cell maps of PTs and paired MLNs and draining LNs from three OSCC patients. The transcriptomic atlas, pseudotime analysis, intercellular communication networks and enrichment analysis of the single cells were characterized. Phenotype and function heterogeneity of fibroblast cells between PTs and MLNs were further verified in vitro. Among 44,052 fibroblasts, we identified two distinct subpopulations of cancer-associated myofibroblastic cells (mCAFs): RGS4+ mCAF1 and COMP + mCAF2. Notably, they exhibited distinct distributions, with mCAF1 predominantly localized in the PTs and mCAF2 in the MLNs. Moreover, pseudotime analysis revealed their distinct origins: mCAF1 originated from inherent normal myofibroblastic cells in the PT, whereas mCAF2 originated from fibroblastic reticular cells in the LNs. Further functional experiments using primary fibroblasts revealed that, compared to mCAF1, mCAF2 in MLNs exhibited weaker crosstalk with immune cells but enhanced extracellular matrix activity, which is closely linked to ENE formation in OSCC. Additionally, we identified two fibroblast subgroups in a transforming state, indicating a potential epithelial-mesenchymal transition. Our research offers profound insights into the heterogeneity of fibroblasts between the PT and MLN in OSCC, serving as an essential resource for future drug discovery endeavors.
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Affiliation(s)
- Qian Zhang
- Department of Oral and Maxillofacial Surgery, Nanjing Stomatological Hospital, Medical School of Nanjing University, China
| | - Liang Ding
- Central Laboratory of Stomatology, Nanjing Stomatological Hospital, Medical School of Nanjing University, China
| | - Jingyi Li
- Department of Oral and Maxillofacial Surgery, Nanjing Stomatological Hospital, Medical School of Nanjing University, China
| | - Kunyu Liu
- Department of Oral and Maxillofacial Surgery, Nanjing Stomatological Hospital, Medical School of Nanjing University, China
| | - Chengwan Xia
- Department of Oral and Maxillofacial Surgery, Nanjing Stomatological Hospital, Medical School of Nanjing University, China
| | - Sheng Chen
- Pathology Department, Nanjing Stomatological Hospital, Medical School of Nanjing University, China
| | - Xiaofeng Huang
- Pathology Department, Nanjing Stomatological Hospital, Medical School of Nanjing University, China
| | - Yumei Pu
- Department of Oral and Maxillofacial Surgery, Nanjing Stomatological Hospital, Medical School of Nanjing University, China
| | - Yuxian Song
- Central Laboratory of Stomatology, Nanjing Stomatological Hospital, Medical School of Nanjing University, China
| | - Qingang Hu
- Department of Oral and Maxillofacial Surgery, Nanjing Stomatological Hospital, Medical School of Nanjing University, China.
| | - Yuxin Wang
- Department of Oral and Maxillofacial Surgery, Nanjing Stomatological Hospital, Medical School of Nanjing University, China.
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2
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Zimmer A, Wang ER, Choudhary G, Zhang P. Protocol for simultaneous isolation of high-quality and high-quantity cardiomyocytes and non-myocyte cells from adult rat hearts. STAR Protoc 2024; 5:103174. [PMID: 38970791 PMCID: PMC11264182 DOI: 10.1016/j.xpro.2024.103174] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/12/2024] [Revised: 05/28/2024] [Accepted: 06/17/2024] [Indexed: 07/08/2024] Open
Abstract
Isolating high-quality different cell types is a powerful approach for understanding cellular compositions and features in the heart, but it is challenging. The available protocols typically focus on isolating one or two cell types. Here, we present a protocol to simultaneously isolate high-quality and high-quantity cardiomyocytes and non-myocyte cells, including immune cells, from adult rat hearts. We describe steps for purifying cells using bovine serum albumin. We also detail procedures for viability analysis and cell type identification using fluorescence-activated cell sorting. For complete details on the use and execution of this protocol, please refer to Zhang et al.,1 Valkov et al.,2 Vang et al.,3 and Li et al.4.
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Affiliation(s)
- Alexsandra Zimmer
- Vascular Research Laboratory, Providence VA Medical Center, Providence, RI 02908, USA; Department of Medicine, Alpert Medical School of Brown University, Providence, RI, USA; Lifespan Cardiovascular Institute, Rhode Island Hospital, Providence, RI, USA
| | - Eric R Wang
- Vascular Research Laboratory, Providence VA Medical Center, Providence, RI 02908, USA; Department of Medicine, Alpert Medical School of Brown University, Providence, RI, USA
| | - Gaurav Choudhary
- Vascular Research Laboratory, Providence VA Medical Center, Providence, RI 02908, USA; Department of Medicine, Alpert Medical School of Brown University, Providence, RI, USA; Lifespan Cardiovascular Institute, Rhode Island Hospital, Providence, RI, USA
| | - Peng Zhang
- Vascular Research Laboratory, Providence VA Medical Center, Providence, RI 02908, USA; Department of Medicine, Alpert Medical School of Brown University, Providence, RI, USA; Lifespan Cardiovascular Institute, Rhode Island Hospital, Providence, RI, USA.
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3
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Garvin AM, Katwa LC. Primary cardiac fibroblast cell culture: methodological considerations for physiologically relevant conditions. Am J Physiol Heart Circ Physiol 2023; 325:H869-H881. [PMID: 37624100 DOI: 10.1152/ajpheart.00224.2023] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/20/2023] [Revised: 07/31/2023] [Accepted: 08/17/2023] [Indexed: 08/26/2023]
Abstract
Primary cardiac fibroblast (CF) tissue culture is a necessary tool for interrogating specific signaling mechanisms that dictate the phenotypic heterogeneity observed in vivo in different disease states. Traditional approaches that use tissue culture plastic and nutrient-rich medium have been shown to induce CF activation and, therefore, alter CF subpopulation composition. This shift away from in vivo phenotypes complicate the interpretation of results through the lens of the animal model. As the field works to identify CF diversity, these methodological flaws have begun to be addressed and more studies are focused on the dynamic interaction of CFs with their environment. This review focuses on the aspects of tissue culture that impact CF activation and, therefore, require consideration when designing in vitro experiments. The complexity of CF biology overlaid onto diverse model systems highlight the need for study-specific optimization and validation.
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Affiliation(s)
- Alexandra M Garvin
- Department of Physiology, Brody School of Medicine, East Carolina University, Greenville, North Carolina, United States
| | - Laxmansa C Katwa
- Department of Physiology, Brody School of Medicine, East Carolina University, Greenville, North Carolina, United States
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4
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Borges JI, Suster MS, Lymperopoulos A. Cardiac RGS Proteins in Human Heart Failure and Atrial Fibrillation: Focus on RGS4. Int J Mol Sci 2023; 24:ijms24076136. [PMID: 37047106 PMCID: PMC10147095 DOI: 10.3390/ijms24076136] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2023] [Revised: 03/22/2023] [Accepted: 03/23/2023] [Indexed: 04/14/2023] Open
Abstract
The regulator of G protein signaling (RGS) proteins are crucial for the termination of G protein signals elicited by G protein-coupled receptors (GPCRs). This superfamily of cell membrane receptors, by far the largest and most versatile in mammals, including humans, play pivotal roles in the regulation of cardiac function and homeostasis. Perturbations in both the activation and termination of their G protein-mediated signaling underlie numerous heart pathologies, including heart failure (HF) and atrial fibrillation (AFib). Therefore, RGS proteins play important roles in the pathophysiology of these two devasting cardiac diseases, and several of them could be targeted therapeutically. Although close to 40 human RGS proteins have been identified, each RGS protein seems to interact only with a specific set of G protein subunits and GPCR types/subtypes in any given tissue or cell type. Numerous in vitro and in vivo studies in animal models, and also in diseased human heart tissue obtained from transplantations or tissue banks, have provided substantial evidence of the roles various cardiomyocyte RGS proteins play in cardiac normal homeostasis as well as pathophysiology. One RGS protein in particular, RGS4, has been reported in what are now decades-old studies to be selectively upregulated in human HF. It has also been implicated in protection against AFib via knockout mice studies. This review summarizes the current understanding of the functional roles of cardiac RGS proteins and their implications for the treatment of HF and AFib, with a specific focus on RGS4 for the aforementioned reasons but also because it can be targeted successfully with small organic molecule inhibitors.
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Affiliation(s)
- Jordana I Borges
- Laboratory for the Study of Neurohormonal Control of the Circulation, Department of Pharmaceutical Sciences, Barry and Judy Silverrman College of Pharmacy, Nova Southeastern University, Fort Lauderdale, FL 33328-2018, USA
| | - Malka S Suster
- Laboratory for the Study of Neurohormonal Control of the Circulation, Department of Pharmaceutical Sciences, Barry and Judy Silverrman College of Pharmacy, Nova Southeastern University, Fort Lauderdale, FL 33328-2018, USA
| | - Anastasios Lymperopoulos
- Laboratory for the Study of Neurohormonal Control of the Circulation, Department of Pharmaceutical Sciences, Barry and Judy Silverrman College of Pharmacy, Nova Southeastern University, Fort Lauderdale, FL 33328-2018, USA
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5
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Del Calvo G, Baggio Lopez T, Lymperopoulos A. The therapeutic potential of targeting cardiac RGS4. Ther Adv Cardiovasc Dis 2023; 17:17539447231199350. [PMID: 37724539 PMCID: PMC10510358 DOI: 10.1177/17539447231199350] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/01/2023] [Accepted: 08/16/2023] [Indexed: 09/21/2023] Open
Abstract
G protein-coupled receptors (GPCRs) play pivotal roles in regulation of cardiac function and homeostasis. To function properly, every cell needs these receptors to be stimulated only when a specific extracellular stimulus is present, and to be silenced the moment that stimulus is removed. The regulator of G protein signaling (RGS) proteins are crucial for the latter to occur at the cell membrane, where the GPCR normally resides. Perturbations in both activation and termination of G protein signaling underlie numerous heart pathologies. Although more than 30 mammalian RGS proteins have been identified, each RGS protein seems to interact only with a specific set of G protein subunits and GPCR types/subtypes in any given tissue or cell type, and this applies to the myocardium as well. A large number of studies have provided substantial evidence for the roles various RGS proteins expressed in cardiomyocytes play in cardiac physiology and heart disease pathophysiology. This review summarizes the current understanding of the functional roles of cardiac RGS proteins and their implications for the treatment of specific heart diseases, such as heart failure and atrial fibrillation. We focus on cardiac RGS4 in particular, since this isoform appears to be selectively (among the RGS protein family) upregulated in human heart failure and is also the target of ongoing drug discovery efforts for the treatment of a variety of diseases.
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Affiliation(s)
- Giselle Del Calvo
- Laboratory for the Study of Neurohormonal Control of the Circulation, Department of Pharmaceutical Sciences, Barry and Judy Silverman College of Pharmacy, Nova Southeastern University, Fort Lauderdale, FL, USA
| | - Teresa Baggio Lopez
- Laboratory for the Study of Neurohormonal Control of the Circulation, Department of Pharmaceutical Sciences, Barry and Judy Silverman College of Pharmacy, Nova Southeastern University, Fort Lauderdale, FL, USA
| | - Anastasios Lymperopoulos
- Laboratory for the Study of Neurohormonal Control of the Circulation, Department of Pharmaceutical Sciences, Barry and Judy Silverman College of Pharmacy, Nova Southeastern University, 3200 South University Drive, HPD (Terry) Building/Room 1350, Fort Lauderdale, FL 33328-2018, USA
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6
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Lymperopoulos A, Suster MS, Borges JI. Cardiovascular GPCR regulation by regulator of G protein signaling proteins. PROGRESS IN MOLECULAR BIOLOGY AND TRANSLATIONAL SCIENCE 2022; 193:145-166. [PMID: 36357075 DOI: 10.1016/bs.pmbts.2022.06.006] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Abstract
G protein-coupled receptors (GPCRs) play pivotal roles in regulation of cardiovascular homeostasis across all vertebrate species, including humans. In terms of normal cellular function, termination of GPCR signaling via the heterotrimeric G proteins is equally (if not more) important to its stimulation. The Regulator of G protein Signaling (RGS) protein superfamily are indispensable for GPCR signaling cessation at the cell membrane, and thus, for cellular control of GPCR signaling and function. Perturbations in both activation and termination of G protein signaling underlie many examples of cardiovascular dysfunction and heart disease pathogenesis. Despite the plethora of over 30 members comprising the mammalian RGS protein superfamily, each member interacts with a specific set of second messenger pathways and GPCR types/subtypes in a tissue/cell type-specific manner. An increasing number of studies over the past two decades have provided compelling evidence for the involvement of various RGS proteins in physiological regulation of cardiovascular GPCRs and, consequently, also in the pathophysiology of several cardiovascular ailments. This chapter summarizes the current understanding of the functional roles of RGS proteins as they pertain to cardiovascular, i.e., heart, blood vessel, and platelet GPCR function, with a particular focus on their implications for chronic heart failure pathophysiology and therapy.
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Affiliation(s)
- Anastasios Lymperopoulos
- Laboratory for the Study of Neurohormonal Control of the Circulation, Department of Pharmaceutical Sciences, Nova Southeastern University College of Pharmacy, Fort Lauderdale, FL, United States.
| | - Malka S Suster
- Laboratory for the Study of Neurohormonal Control of the Circulation, Department of Pharmaceutical Sciences, Nova Southeastern University College of Pharmacy, Fort Lauderdale, FL, United States
| | - Jordana I Borges
- Laboratory for the Study of Neurohormonal Control of the Circulation, Department of Pharmaceutical Sciences, Nova Southeastern University College of Pharmacy, Fort Lauderdale, FL, United States
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7
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Cardioprotective effects of early intervention with sacubitril/valsartan on pressure overloaded rat hearts. Sci Rep 2021; 11:16542. [PMID: 34400686 PMCID: PMC8368201 DOI: 10.1038/s41598-021-95988-3] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/16/2021] [Accepted: 08/03/2021] [Indexed: 12/11/2022] Open
Abstract
Left ventricular remodeling due to pressure overload is associated with poor prognosis. Sacubitril/valsartan is the first-in-class Angiotensin Receptor Neprilysin Inhibitor and has been demonstrated to have superior beneficial effects in the settings of heart failure. The aim of this study was to determine whether sacubitril/valsartan has cardioprotective effect in the early intervention of pressure overloaded hearts and whether it is superior to valsartan alone. We induced persistent left ventricular pressure overload in rats by ascending aortic constriction surgery and orally administrated sacubitril/valsartan, valsartan, or vehicle one week post operation for 10 weeks. We also determined the effects of sacubitril/valsartan over valsartan on adult ventricular myocytes and fibroblasts that were isolated from healthy rats and treated in culture. We found that early intervention with sacubitril/valsartan is superior to valsartan in reducing pressure overload-induced ventricular fibrosis and in reducing angiotensin II-induced adult ventricular fibroblast activation. While neither sacubitril/valsartan nor valsartan changes cardiac hypertrophy development, early intervention with sacubitril/valsartan protects ventricular myocytes from mitochondrial dysfunction and is superior to valsartan in reducing mitochondrial oxidative stress in response to persistent left ventricular pressure overload. In conclusion, our findings demonstrate that sacubitril/valsartan has a superior cardioprotective effect over valsartan in the early intervention of pressure overloaded hearts, which is independent of the reduction of left ventricular afterload. Our study provides evidence in support of potential benefits of the use of sacubitril/valsartan in patients with resistant hypertension or in patients with severe aortic stenosis.
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8
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Vang A, da Silva Gonçalves Bos D, Fernandez-Nicolas A, Zhang P, Morrison AR, Mancini TJ, Clements RT, Polina I, Cypress MW, Jhun BS, Hawrot E, Mende U, O-Uchi J, Choudhary G. α7 Nicotinic acetylcholine receptor mediates right ventricular fibrosis and diastolic dysfunction in pulmonary hypertension. JCI Insight 2021; 6:142945. [PMID: 33974567 PMCID: PMC8262476 DOI: 10.1172/jci.insight.142945] [Citation(s) in RCA: 16] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/10/2020] [Accepted: 05/06/2021] [Indexed: 12/12/2022] Open
Abstract
Right ventricular (RV) fibrosis is a key feature of maladaptive RV hypertrophy and dysfunction and is associated with poor outcomes in pulmonary hypertension (PH). However, mechanisms and therapeutic strategies to mitigate RV fibrosis remain unrealized. Previously, we identified that cardiac fibroblast α7 nicotinic acetylcholine receptor (α7 nAChR) drives smoking-induced RV fibrosis. Here, we sought to define the role of α7 nAChR in RV dysfunction and fibrosis in the settings of RV pressure overload as seen in PH. We show that RV tissue from PH patients has increased collagen content and ACh expression. Using an experimental rat model of PH, we demonstrate that RV fibrosis and dysfunction are associated with increases in ACh and α7 nAChR expression in the RV but not in the left ventricle (LV). In vitro studies show that α7 nAChR activation leads to an increase in adult ventricular fibroblast proliferation and collagen content mediated by a Ca2+/epidermal growth factor receptor (EGFR) signaling mechanism. Pharmacological antagonism of nAChR decreases RV collagen content and improves RV function in the PH model. Furthermore, mice lacking α7 nAChR exhibit improved RV diastolic function and have lower RV collagen content in response to persistently increased RV afterload, compared with WT controls. These finding indicate that enhanced α7 nAChR signaling is an important mechanism underlying RV fibrosis and dysfunction, and targeted inhibition of α7 nAChR is a potentially novel therapeutic strategy in the setting of increased RV afterload.
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Affiliation(s)
- Alexander Vang
- Vascular Research Laboratory, Providence VA Medical Center, Providence, Rhode Island, USA
| | - Denielli da Silva Gonçalves Bos
- Vascular Research Laboratory, Providence VA Medical Center, Providence, Rhode Island, USA.,Department of Medicine, Alpert Medical School of Brown University, Providence, Rhode Island, USA
| | - Ana Fernandez-Nicolas
- Vascular Research Laboratory, Providence VA Medical Center, Providence, Rhode Island, USA.,Department of Medicine, Alpert Medical School of Brown University, Providence, Rhode Island, USA
| | - Peng Zhang
- Vascular Research Laboratory, Providence VA Medical Center, Providence, Rhode Island, USA.,Department of Medicine, Alpert Medical School of Brown University, Providence, Rhode Island, USA
| | - Alan R. Morrison
- Vascular Research Laboratory, Providence VA Medical Center, Providence, Rhode Island, USA.,Department of Medicine, Alpert Medical School of Brown University, Providence, Rhode Island, USA
| | - Thomas J. Mancini
- Vascular Research Laboratory, Providence VA Medical Center, Providence, Rhode Island, USA
| | - Richard T. Clements
- Vascular Research Laboratory, Providence VA Medical Center, Providence, Rhode Island, USA.,Biomedical & Pharmaceutical Sciences, University of Rhode Island, Kingston, Rhode Island, USA
| | - Iuliia Polina
- Department of Medicine, University of Minnesota, Minneapolis, Minnesota, USA
| | - Michael W. Cypress
- Department of Medicine, University of Minnesota, Minneapolis, Minnesota, USA
| | - Bong Sook Jhun
- Department of Medicine, University of Minnesota, Minneapolis, Minnesota, USA
| | - Edward Hawrot
- Department of Molecular Pharmacology, Physiology, and Biotechnology, Alpert Medical School of Brown University, Providence, Rhode Island, USA
| | - Ulrike Mende
- Department of Medicine, Alpert Medical School of Brown University, Providence, Rhode Island, USA.,Cardiovascular Research Center, Lifespan Cardiovascular Institute, Rhode Island Hospital, Providence, Rhode Island, USA
| | - Jin O-Uchi
- Department of Medicine, University of Minnesota, Minneapolis, Minnesota, USA
| | - Gaurav Choudhary
- Vascular Research Laboratory, Providence VA Medical Center, Providence, Rhode Island, USA.,Department of Medicine, Alpert Medical School of Brown University, Providence, Rhode Island, USA
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9
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Guo J, Hang P, Yu J, Li W, Zhao X, Sun Y, Fan Z, Du Z. The association between RGS4 and choline in cardiac fibrosis. Cell Commun Signal 2021; 19:46. [PMID: 33892733 PMCID: PMC8063380 DOI: 10.1186/s12964-020-00682-y] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/21/2020] [Accepted: 11/03/2020] [Indexed: 11/10/2022] Open
Abstract
Background Myocardial fibrosis is caused by the adverse and powerful remodeling of the heart secondary to the death of cardiomyocytes after myocardial infarction. Regulators of G protein Signaling (RGS) 4 is involved in cardiac diseases through regulating G protein-coupled receptors (GPCRs). Methods Cardiac fibrosis models were established through cardiac fibroblasts (CFs) treatment with transforming growth factor (TGF)-β1 in vitro and mice subjected to myocardial infarction in vivo. The mRNA expression of RGS4, collagen I/III and α-SMA detected by qRT-PCR. Protein level of RGS4, collagen I, CTGF and α-SMA detected by Western blot. The ejection fraction (EF%) and fractional shortening (FS%) of mice were measured by echocardiography. Collagen deposition of mice was tested by Masson staining. Results The expression of RGS4 increased in CFs treatment with TGF-β1 and in MI mice. The model of cardiac fibrosis detected by qRT-PCR and Western blot. It was demonstrated that inhibition of RGS4 expression improved cardiac fibrosis by transfection with small interfering RNA in CFs and injection with lentivirus shRNA in mice. The protective effect of choline against cardiac fibrosis was counteracted by overexpression of RGS4 in vitro and in vivo. Moreover, choline inhibited the protein level of TGF-β1, p-Smad2/3, p-p38 and p-ERK1/2 in CFs treated with TGF-β1, which were restored by RGS4 overexpression. Conclusion This study demonstrated that RGS4 promoted cardiac fibrosis and attenuated the anti-cardiac fibrosis of choline. RGS4 may weaken anti-cardiac fibrosis of choline through TGF-β1/Smad and MAPK signaling pathways. ![]()
Video Abstract: Video Byte of this article
Supplementary Information The online version contains supplementary material availlable at 10.1186/s12964-020-00682-y.
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Affiliation(s)
- Jing Guo
- Institute of Clinical Pharmacology, The Second Affiliated Hospital of Harbin Medical University (The University Key Laboratory of Drug Research, Heilongjiang Province), Harbin, 150086, People's Republic of China.,Department of Clinical Pharmacology, College of Pharmacy, Harbin Medical University, Harbin, 150081, People's Republic of China
| | - Pengzhou Hang
- Institute of Clinical Pharmacology, The Second Affiliated Hospital of Harbin Medical University (The University Key Laboratory of Drug Research, Heilongjiang Province), Harbin, 150086, People's Republic of China.,Department of Clinical Pharmacology, College of Pharmacy, Harbin Medical University, Harbin, 150081, People's Republic of China
| | - Jie Yu
- Institute of Clinical Pharmacology, The Second Affiliated Hospital of Harbin Medical University (The University Key Laboratory of Drug Research, Heilongjiang Province), Harbin, 150086, People's Republic of China.,Department of Clinical Pharmacology, College of Pharmacy, Harbin Medical University, Harbin, 150081, People's Republic of China
| | - Wen Li
- Institute of Clinical Pharmacology, The Second Affiliated Hospital of Harbin Medical University (The University Key Laboratory of Drug Research, Heilongjiang Province), Harbin, 150086, People's Republic of China.,Department of Clinical Pharmacology, College of Pharmacy, Harbin Medical University, Harbin, 150081, People's Republic of China
| | - Xiuye Zhao
- Institute of Clinical Pharmacology, The Second Affiliated Hospital of Harbin Medical University (The University Key Laboratory of Drug Research, Heilongjiang Province), Harbin, 150086, People's Republic of China.,Department of Clinical Pharmacology, College of Pharmacy, Harbin Medical University, Harbin, 150081, People's Republic of China
| | - Yue Sun
- Institute of Clinical Pharmacology, The Second Affiliated Hospital of Harbin Medical University (The University Key Laboratory of Drug Research, Heilongjiang Province), Harbin, 150086, People's Republic of China.,Department of Clinical Pharmacology, College of Pharmacy, Harbin Medical University, Harbin, 150081, People's Republic of China
| | - Ziyi Fan
- Institute of Clinical Pharmacology, The Second Affiliated Hospital of Harbin Medical University (The University Key Laboratory of Drug Research, Heilongjiang Province), Harbin, 150086, People's Republic of China.,Department of Clinical Pharmacology, College of Pharmacy, Harbin Medical University, Harbin, 150081, People's Republic of China
| | - Zhimin Du
- Institute of Clinical Pharmacology, The Second Affiliated Hospital of Harbin Medical University (The University Key Laboratory of Drug Research, Heilongjiang Province), Harbin, 150086, People's Republic of China. .,Department of Clinical Pharmacology, College of Pharmacy, Harbin Medical University, Harbin, 150081, People's Republic of China. .,State Key Laboratory of Quality Reserch in Chinese Medicines, Macau University of Science and Technology, Macau, Macau, 150086, People's Republic of China.
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10
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Lwin HP, Choi YH, Lee MW, Yu JH, Shin KS. RgsA Attenuates the PKA Signaling, Stress Response, and Virulence in the Human Opportunistic Pathogen Aspergillus fumigatus. Int J Mol Sci 2019; 20:ijms20225628. [PMID: 31717953 PMCID: PMC6888639 DOI: 10.3390/ijms20225628] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/23/2019] [Revised: 11/05/2019] [Accepted: 11/07/2019] [Indexed: 12/14/2022] Open
Abstract
The regulator of G-protein signaling (RGS) proteins play an important role in upstream control of heterotrimeric G-protein signaling pathways. In the genome of the human opportunistic pathogenic fungus Aspergillus fumigatus, six RGS protein-encoding genes are present. To characterize the rgsA gene predicted to encode a protein with an RGS domain, we generated an rgsA null mutant and observed the phenotypes of the mutant. The deletion (Δ) of rgsA resulted in increased radial growth and enhanced asexual sporulation in both solid and liquid culture conditions. Accordingly, transcripts levels of the key asexual developmental regulators abaA, brlA, and wetA are elevated in the ΔrgsA mutant. Moreover, ΔrgsA resulted in elevated spore germination rates in the absence of a carbon source. The activity of cAMP-dependent protein kinase A (PKA) and mRNA levels of genes encoding PKA signaling elements are elevated by ΔrgsA. In addition, mRNA levels of genes associated with stress-response signaling increased with the lack of rgsA, and the ΔrgsA spores showed enhanced tolerance against oxidative stressors. Comparative transcriptomic analyses revealed that the ΔrgsA mutant showed higher mRNA levels of gliotoxin (GT) biosynthetic genes. Accordingly, the rgsA null mutant exhibited increased production of GT and elevated virulence in the mouse. Conversely, the majority of genes encoding glucan degrading enzymes were down-regulated by ΔrgsA, and endoglucanase activities were reduced. In summary, RgsA plays multiple roles, governing growth, development, stress responses, virulence, and external polymer degradation-likely by attenuating PKA signaling.
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Affiliation(s)
- Hnin Phyu Lwin
- Department of Microbiology, Graduate School, Daejeon University, Daejeon 34520, Korea; (H.P.L.); (Y.-H.C.)
| | - Yong-Ho Choi
- Department of Microbiology, Graduate School, Daejeon University, Daejeon 34520, Korea; (H.P.L.); (Y.-H.C.)
| | - Min-Woo Lee
- Soonchunhyang Institute of Medi-bio Science, Soonchunhyang University, Chungcheongnam-do 31151, Korea;
| | - Jae-Hyuk Yu
- Department of Bacteriology, University of Wisconsin-Madison, Madison, WI 53706, USA
- Department of Systems Biotechnology, Konkuk University, Seoul 05029, Korea
- Correspondence: (J.-H.Y.); (K.-S.S.); Tel.: +1-608-262-4696 (J.-H.Y.); +82-42-280-2439 (K.-S.S.); Fax: +1-608-262-2976 (J.-H.Y.); +82-42-280-2608 (K.-S.S.)
| | - Kwang-Soo Shin
- Department of Microbiology, Graduate School, Daejeon University, Daejeon 34520, Korea; (H.P.L.); (Y.-H.C.)
- Correspondence: (J.-H.Y.); (K.-S.S.); Tel.: +1-608-262-4696 (J.-H.Y.); +82-42-280-2439 (K.-S.S.); Fax: +1-608-262-2976 (J.-H.Y.); +82-42-280-2608 (K.-S.S.)
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11
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Valkov N, King ME, Moeller J, Liu H, Li X, Zhang P. MicroRNA-1-Mediated Inhibition of Cardiac Fibroblast Proliferation Through Targeting Cyclin D2 and CDK6. Front Cardiovasc Med 2019; 6:65. [PMID: 31157242 PMCID: PMC6533459 DOI: 10.3389/fcvm.2019.00065] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2019] [Accepted: 05/01/2019] [Indexed: 12/24/2022] Open
Abstract
MicroRNA-1 (miRNA-1) has been long viewed as a muscle-specific miRNA and plays a critical role in myocardium and cardiomyocytes by controlling myocyte growth and rhythm. We identified that miRNA-1 is expressed in cardiac fibroblasts, which are one of the major non-muscle cell types in myocardium and are responsible for cardiac fibrosis in pathological conditions. In this study, we aimed to investigate the effect and mechanism of action of miRNA-1 on cardiac fibroblast proliferation. Subcutaneous angiotensin II (Ang II) infusion via osmotic minipumps for 4 weeks was used to induce myocardial interstitial fibrosis in male Sprague-Dawley rats. MiRNA-1 expression was significantly down-regulated by 68% in freshly isolated ventricular fibroblasts from Ang II-infused rats than that from control rats. Similar results were obtained in adult rat ventricular fibroblasts that were stimulated in culture by Ang II or TGFβ for 48 h. Functionally, overexpression of miRNA-1 inhibited fibroblast proliferation, whereas knockdown of endogenous miRNA-1 increased fibroblast proliferation. We then identified and validated cyclin D2 and cyclin-dependent kinase 6 (CDK6) as direct targets of miRNA-1 in cardiac fibroblasts using biochemical assays. Moreover, we showed that the inhibitory effects of miRNA-1 on cardiac fibroblast proliferation can be blunted by overexpression of its target, cyclin D2. In conclusion, our findings demonstrate miRNA-1 expression and regulation in adult ventricular fibroblasts, where it acts as a novel negative regulator of adult cardiac fibroblast proliferation that is at least partially mediated by direct targeting of two cell cycle regulators. Our results expand the understanding of the regulatory roles of miRNA-1 in cardiac cells (i.e., from myocytes to a major non-muscle cells in the heart).
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Affiliation(s)
- Nedyalka Valkov
- Cardiovascular Research Center, Cardiovascular Institute, Rhode Island Hospital and Alpert Medical School of Brown University, Providence, RI, United States.,Department of Molecular Pharmacology, Physiology and Biotechnology, Brown University, Providence, RI, United States
| | - Michelle E King
- Cardiovascular Research Center, Cardiovascular Institute, Rhode Island Hospital and Alpert Medical School of Brown University, Providence, RI, United States
| | - Jacob Moeller
- Cardiovascular Research Center, Cardiovascular Institute, Rhode Island Hospital and Alpert Medical School of Brown University, Providence, RI, United States
| | - Hong Liu
- Cardiovascular Research Center, Cardiovascular Institute, Rhode Island Hospital and Alpert Medical School of Brown University, Providence, RI, United States
| | - Xiaofei Li
- Cardiovascular Research Center, Cardiovascular Institute, Rhode Island Hospital and Alpert Medical School of Brown University, Providence, RI, United States
| | - Peng Zhang
- Cardiovascular Research Center, Cardiovascular Institute, Rhode Island Hospital and Alpert Medical School of Brown University, Providence, RI, United States
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12
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El Awdan SA, Abdel Rahman RF, Ibrahim HM, Hegazy RR, El Marasy SA, Badawi M, Arbid MS. Regression of fibrosis by cilostazol in a rat model of thioacetamide-induced liver fibrosis: Up regulation of hepatic cAMP, and modulation of inflammatory, oxidative stress and apoptotic biomarkers. PLoS One 2019; 14:e0216301. [PMID: 31067255 PMCID: PMC6505801 DOI: 10.1371/journal.pone.0216301] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/17/2019] [Accepted: 04/17/2019] [Indexed: 12/20/2022] Open
Abstract
In liver fibrosis, conversion of fibroblasts to profibrogenic myofibroblasts significantly drives the development of the disease. A crucial role of cyclic adenosine monophosphate (cAMP) in regulation of fibroblast function has been reported. Increase in cAMP levels has been found to decrease fibroblast proliferation, inhibit their conversion to myofibroblast, and stimulate their death. cAMP is generated by adenyl cyclase (AC), and degraded by cyclic nucleotide phosphodiesterase (PDE). In this study, the antifibrotic effect of a PDE inhibitor, cilostazol (Cilo), on a rat model of liver fibrosis induced by thioacetamide (TAA) was investigated. Four groups of rats were used; the first group received the vehicles and served as the normal control group, while liver fibrosis was induced in the other groups using (TAA, 200 mg/kg/biweekly for 8 successive weeks, ip). The last two groups were treated with Cilo (50 and 100 mg/kg/day, po, respectively). Induction of liver fibrosis in TAA-treated rats was observed as evidenced by the biochemical and histopathological findings. On the other hand, a potent antifibrotic effect was observed in the groups treated with Cilo, with preference to the higher dose. In these groups, a significant increase in the liver content of cAMP was demonstrated that was accompanied by reduction in the hepatic expression of key fibrogenic cytokines, growth factors, and inflammatory biomarkers, including interleukin-6, tumor necrosis factor-alpha, nuclear factor kappa B, and transforming growth factor-beta as compared to TAA group. Moreover, amelioration of TAA-induced oxidative stress and apoptosis in the liver has been observed. These findings reveal the antifibrotic effect of Cilo against TAA-induced liver fibrosis in rats, and suggest regulation of cAMP pathway, together with the modulation of oxidative stress, inflammation, and apoptosis as mechanistic cassette underlines this effect.
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Affiliation(s)
- Sally A. El Awdan
- Pharmacology Department, Medical Division, National Research Centre, Giza, Egypt
| | | | - Heba M. Ibrahim
- Pharmacology Department, Medical Division, National Research Centre, Giza, Egypt
| | - Rehab R. Hegazy
- Pharmacology Department, Medical Division, National Research Centre, Giza, Egypt
| | - Salma A. El Marasy
- Pharmacology Department, Medical Division, National Research Centre, Giza, Egypt
| | - Manal Badawi
- Pathology Department, Medical Division, National Research Centre, Giza, Egypt
| | - Mahmoud S. Arbid
- Pharmacology Department, Medical Division, National Research Centre, Giza, Egypt
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13
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RgsD negatively controls development, toxigenesis, stress response, and virulence in Aspergillus fumigatus. Sci Rep 2019; 9:811. [PMID: 30692551 PMCID: PMC6349852 DOI: 10.1038/s41598-018-37124-2] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/29/2018] [Accepted: 11/28/2018] [Indexed: 12/19/2022] Open
Abstract
The regulator of G protein signaling (RGS) domain proteins generally attenuate heterotrimeric G protein signaling, thereby fine-tune the duration and strength of signal transduction. In this study, we characterize the functions of RgsD, one of the six RGS domain proteins present in the human pathogenic fungus Aspergillus fumigatus. The deletion (Δ) of rgsD results in enhanced asexual sporulation coupled with increased mRNA levels of key developmental activators. Moreover, ΔrgsD leads to increased spore tolerance to UV and oxidative stress, which might be associated with the enhanced expression of melanin biosynthetic genes and increased amount of melanin. Yeast two-hybrid assays reveal that RgsD can interact with the three Gα proteins GpaB, GanA, and GpaA, showing the highest interaction potential with GpaB. Importantly, the ΔrgsD mutant shows elevated expression of genes in the cAMP-dependent protein kinase A (PKA) pathway and PKA catalytic activity. The ΔrgsD mutant also display increased gliotoxin production and elevated virulence toward Galleria mellonella wax moth larvae. Transcriptomic analyses using RNA-seq reveal the expression changes associated with the diverse phenotypic outcomes caused by ΔrgsD. Collectively, we conclude that RgsD attenuates cAMP-PKA signaling pathway and negatively regulates asexual development, toxigenesis, melanin production, and virulence in A. fumigatus.
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14
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Interplay between negative and positive design elements in Gα helical domains of G proteins determines interaction specificity toward RGS2. Biochem J 2018; 475:2293-2304. [PMID: 29925530 DOI: 10.1042/bcj20180285] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/11/2018] [Revised: 06/18/2018] [Accepted: 06/19/2018] [Indexed: 01/26/2023]
Abstract
Regulators of G protein signaling (RGS) proteins inactivate Gα subunits, thereby controlling G protein-coupled signaling networks. Among all RGS proteins, RGS2 is unique in interacting only with the Gαq but not with the Gαi subfamily. Previous studies suggested that this specificity is determined by the RGS domain and, in particular, by three RGS2-specific residues that lead to a unique mode of interaction with Gαq This interaction was further proposed to act through contacts with the Gα GTPase domain. Here, we combined energy calculations and GTPase activity measurements to determine which Gα residues dictate specificity toward RGS2. We identified putative specificity-determining residues in the Gα helical domain, which among G proteins is found only in Gα subunits. Replacing these helical domain residues in Gαi with their Gαq counterparts resulted in a dramatic specificity switch toward RGS2. We further show that Gα-RGS2 specificity is set by Gαi residues that perturb interactions with RGS2, and by Gαq residues that enhance these interactions. These results show, for the first time, that the Gα helical domain is central to dictating specificity toward RGS2, suggesting that this domain plays a general role in governing Gα-RGS specificity. Our insights provide new options for manipulating RGS-G protein interactions in vivo, for better understanding of their 'wiring' into signaling networks, and for devising novel drugs targeting such interactions.
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15
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Zhang Y, Luo G, Zhang Y, Zhang M, Zhou J, Gao W, Xuan X, Yang X, Yang D, Tian Z, Ni B, Tang J. Critical effects of long non-coding RNA on fibrosis diseases. Exp Mol Med 2018; 50:e428. [PMID: 29350677 PMCID: PMC5799794 DOI: 10.1038/emm.2017.223] [Citation(s) in RCA: 32] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/02/2017] [Revised: 07/03/2017] [Accepted: 07/05/2017] [Indexed: 02/07/2023] Open
Abstract
The expression or dysfunction of long non-coding RNAs (lncRNAs) is closely related to various hereditary diseases, autoimmune diseases, metabolic diseases and tumors. LncRNAs were also recently recognized as functional regulators of fibrosis, which is a secondary process in many of these diseases and a primary pathology in fibrosis diseases. We review the latest findings on lncRNAs in fibrosis diseases of the liver, myocardium, kidney, lung and peritoneum. We also discuss the potential of disease-related lncRNAs as therapeutic targets for the clinical treatment of human fibrosis diseases.
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Affiliation(s)
- Yue Zhang
- Department of Dermatology, 105th Hospital of PLA, Hefei, China.,Department of Pathophysiology and High Altitude Pathology, Third Military Medical University, Chongqing, China.,Graduate School, Bengbu Medical College, Bengbu, China
| | - Gang Luo
- Department of Pathophysiology and High Altitude Pathology, Third Military Medical University, Chongqing, China
| | - Yi Zhang
- Department of Clinical Laboratory, 150th Hospital of PLA, Luoyang, China
| | - Mengjie Zhang
- Department of Pathophysiology and High Altitude Pathology, Third Military Medical University, Chongqing, China
| | - Jian Zhou
- Department of Pathophysiology and High Altitude Pathology, Third Military Medical University, Chongqing, China
| | - Weiwu Gao
- Department of Pathophysiology and High Altitude Pathology, Third Military Medical University, Chongqing, China
| | - Xiuyun Xuan
- Department of Microbiology and Immunology, Shanxi Medical University, Taiyuan, China
| | - Xia Yang
- Institute of Immunology, PLA, Third Military Medical University, Chongqing, China
| | - Di Yang
- Institute of Immunology, PLA, Third Military Medical University, Chongqing, China
| | - Zhiqiang Tian
- Institute of Immunology, PLA, Third Military Medical University, Chongqing, China
| | - Bing Ni
- Department of Pathophysiology and High Altitude Pathology, Third Military Medical University, Chongqing, China
| | - Jun Tang
- Department of Dermatology, 105th Hospital of PLA, Hefei, China.,Graduate School, Bengbu Medical College, Bengbu, China
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16
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Kim Y, Heo IB, Yu JH, Shin KS. Characteristics of a Regulator of G-Protein Signaling (RGS) rgsC in Aspergillus fumigatus. Front Microbiol 2017; 8:2058. [PMID: 29109714 PMCID: PMC5660106 DOI: 10.3389/fmicb.2017.02058] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/03/2017] [Accepted: 10/06/2017] [Indexed: 12/12/2022] Open
Abstract
The regulator of G-protein signaling (RGS) proteins have a conserved RGS domain that facilitates the intrinsic GTPase activity of an activated Gα subunit of heterotrimeric G protein, thereby attenuating signal transduction. Among six predicted RGS proteins in the opportunistic human pathogenic fungus Aspergillus fumigatus, only three (FlbA, GprK, and Rax1) have been studied. The unexplored RgsC composed of the Phox-associated (PXA), RGS, Phox homology (PX), and Nexin_C superfamily domains is highly conserved in many ascomycete fungi, suggesting a crucial role of RgsC in fungal biology. To address this, we have investigated functions of the rgsC gene. The deletion (Δ) of rgsC causes impaired vegetative growth and asexual development coupled with reduced expression of key developmental regulators. Moreover, ΔrgsC results in accelerated and elevated conidial germination regardless of the presence or absence of an external carbon source. Furthermore, ΔrgsC causes reduced conidial tolerance to oxidative stress. In addition, activities and expression of catalases and superoxide dismutases (SODs) are severely decreased in the ΔrgsC mutant. The deletion of rgsC results in a slight reduction in conidial tolerance to cell wall damaging agents, yet significantly lowered mRNA levels of cell wall integrity/biogenesis transcription factors, indicating that RgsC may function in proper activation of cell wall stress response. The ΔrgsC mutant exhibits defective gliotoxin (GT) production and decreased virulence in the wax moth larvae, Galleria mellonella. Transcriptomic studies reveal that a majority of transporters is down-regulated by ΔrgsC and growth of the ΔrgsC mutant is reduced on inorganic and simple nitrogen medium, suggesting that RgsC may function in external nitrogen source sensing and/or transport. In summary, RgsC is necessary for proper growth, development, stress response, GT production, and external nutrients sensing.
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Affiliation(s)
- Young Kim
- Department of Biological Science, Daejeon University, Daejeon, South Korea
| | - In-Beom Heo
- Department of Biological Science, Daejeon University, Daejeon, South Korea
| | - Jae-Hyuk Yu
- Departments of Bacteriology and Genetics, University of Wisconsin-Madison, Madison, WI, United States
| | - Kwang-Soo Shin
- Department of Biological Science, Daejeon University, Daejeon, South Korea
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17
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Kofron CM, Kim TY, King ME, Xie A, Feng F, Park E, Qu Z, Choi BR, Mende U. G q-activated fibroblasts induce cardiomyocyte action potential prolongation and automaticity in a three-dimensional microtissue environment. Am J Physiol Heart Circ Physiol 2017; 313:H810-H827. [PMID: 28710068 DOI: 10.1152/ajpheart.00181.2017] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/22/2017] [Revised: 06/13/2017] [Accepted: 07/03/2017] [Indexed: 11/22/2022]
Abstract
Cardiac fibroblasts (CFs) are known to regulate cardiomyocyte (CM) function in vivo and in two-dimensional in vitro cultures. This study examined the effect of CF activation on the regulation of CM electrical activity in a three-dimensional (3-D) microtissue environment. Using a scaffold-free 3-D platform with interspersed neonatal rat ventricular CMs and CFs, Gq-mediated signaling was selectively enhanced in CFs by Gαq adenoviral infection before coseeding with CMs in nonadhesive hydrogels. After 3 days, the microtissues were analyzed by signaling assay, histological staining, quantitative PCR, Western blots, optical mapping with voltage- or Ca2+-sensitive dyes, and microelectrode recordings of CF resting membrane potential (RMPCF). Enhanced Gq signaling in CFs increased microtissue size and profibrotic and prohypertrophic markers. Expression of constitutively active Gαq in CFs prolonged CM action potential duration (by 33%) and rise time (by 31%), prolonged Ca2+ transient duration (by 98%) and rise time (by 65%), and caused abnormal electrical activity based on depolarization-induced automaticity. Constitutive Gq activation in CFs also depolarized RMPCF from -33 to -20 mV and increased connexin 43 and connexin 45 expression. Computational modeling confers that elevated RMPCF and increased cell-cell coupling between CMs and CFs in a 3-D environment could lead to automaticity. In conclusion, our data demonstrate that CF activation alone is capable of altering action potential and Ca2+ transient characteristics of CMs, leading to proarrhythmic electrical activity. Our results also emphasize the importance of a 3-D environment where cell-cell interactions are prevalent, underscoring that CF activation in 3-D tissue plays a significant role in modulating CM electrophysiology and arrhythmias.NEW & NOTEWORTHY In a three-dimensional microtissue model, which lowers baseline activation of cardiac fibroblasts but enables cell-cell, paracrine, and cell-extracellular matrix interactions, we demonstrate that selective cardiac fibroblast activation by enhanced Gq signaling, a pathophysiological trigger in the diseased heart, modulates cardiomyocyte electrical activity, leading to proarrhythmogenic automaticity.
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Affiliation(s)
- C M Kofron
- Cardiovascular Research Center, Cardiovascular Institute, Rhode Island Hospital and Alpert Medical School of Brown University, Providence, Rhode Island; and
| | - T Y Kim
- Cardiovascular Research Center, Cardiovascular Institute, Rhode Island Hospital and Alpert Medical School of Brown University, Providence, Rhode Island; and
| | - M E King
- Cardiovascular Research Center, Cardiovascular Institute, Rhode Island Hospital and Alpert Medical School of Brown University, Providence, Rhode Island; and
| | - A Xie
- Cardiovascular Research Center, Cardiovascular Institute, Rhode Island Hospital and Alpert Medical School of Brown University, Providence, Rhode Island; and
| | - F Feng
- Cardiovascular Research Center, Cardiovascular Institute, Rhode Island Hospital and Alpert Medical School of Brown University, Providence, Rhode Island; and
| | - E Park
- Cardiovascular Research Center, Cardiovascular Institute, Rhode Island Hospital and Alpert Medical School of Brown University, Providence, Rhode Island; and
| | - Z Qu
- Department of Medicine, University of California, Los Angeles, California
| | - B-R Choi
- Cardiovascular Research Center, Cardiovascular Institute, Rhode Island Hospital and Alpert Medical School of Brown University, Providence, Rhode Island; and
| | - U Mende
- Cardiovascular Research Center, Cardiovascular Institute, Rhode Island Hospital and Alpert Medical School of Brown University, Providence, Rhode Island; and
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18
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Vang A, Clements RT, Chichger H, Kue N, Allawzi A, O'Connell K, Jeong EM, Dudley SC, Sakhatskyy P, Lu Q, Zhang P, Rounds S, Choudhary G. Effect of α7 nicotinic acetylcholine receptor activation on cardiac fibroblasts: a mechanism underlying RV fibrosis associated with cigarette smoke exposure. Am J Physiol Lung Cell Mol Physiol 2017; 312:L748-L759. [PMID: 28258105 PMCID: PMC5451597 DOI: 10.1152/ajplung.00393.2016] [Citation(s) in RCA: 29] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/06/2016] [Revised: 02/17/2017] [Accepted: 02/23/2017] [Indexed: 01/03/2023] Open
Abstract
Right ventricular (RV) dysfunction is associated with numerous smoking-related illnesses, including chronic obstructive pulmonary disease (COPD), in which it is present even in the absence of pulmonary hypertension. It is unknown whether exposure to cigarette smoke (CS) has direct effects on RV function and cardiac fibroblast (CF) proliferation or collagen synthesis. In this study, we evaluated cardiac function and fibrosis in mice exposed to CS and determined mechanisms of smoke-induced changes in CF signaling and fibrosis. AKR mice were exposed to CS for 6 wk followed by echocardiography and evaluation of cardiac hypertrophy, collagen content, and pulmonary muscularization. Proliferation and collagen content were evaluated in primary isolated rat CFs exposed to CS extract (CSE) or nicotine. Markers of cell proliferation, fibrosis, and proliferative signaling were determined by immunoblot or Sircol collagen assay. Mice exposed to CS had significantly decreased RV function, as determined by tricuspid annular plane systolic excursion. There were no changes in left ventricular parameters. RV collagen content was significantly elevated, but there was no change in RV hypertrophy or pulmonary vascular muscularization. CSE directly increased CF proliferation and collagen content in CF. Nicotine alone reproduced these effects. CSE and nicotine-induced fibroblast proliferation and collagen content were mediated through α7 nicotinic acetylcholine receptors and were dependent on PKC-α, PKC-δ, and reduced p38-MAPK phosphorylation. CS and nicotine have direct effects on CFs to induce proliferation and fibrosis, which may negatively affect right heart function.
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MESH Headings
- Animals
- Cell Proliferation/drug effects
- Enzyme Activation/drug effects
- Fibroblasts/drug effects
- Fibroblasts/metabolism
- Fibroblasts/pathology
- Heart Ventricles/drug effects
- Heart Ventricles/pathology
- Heart Ventricles/physiopathology
- Hemodynamics/drug effects
- Hypertrophy, Right Ventricular/complications
- Hypertrophy, Right Ventricular/diagnostic imaging
- Hypertrophy, Right Ventricular/pathology
- Hypertrophy, Right Ventricular/physiopathology
- MAP Kinase Signaling System/drug effects
- Male
- Mice, Inbred AKR
- Myocardium/pathology
- Nicotine/pharmacology
- Phosphorylation/drug effects
- Protein Kinase C-alpha/metabolism
- Protein Kinase C-delta/metabolism
- Rats, Sprague-Dawley
- Smoking/adverse effects
- Vascular Remodeling/drug effects
- Ventricular Dysfunction, Right/complications
- Ventricular Dysfunction, Right/diagnostic imaging
- Ventricular Dysfunction, Right/pathology
- Ventricular Dysfunction, Right/physiopathology
- alpha7 Nicotinic Acetylcholine Receptor/metabolism
- p38 Mitogen-Activated Protein Kinases/metabolism
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Affiliation(s)
- Alexander Vang
- Vascular Research Laboratory, Providence Veterans Affairs Medical Center, Providence, Rhode Island
| | - Richard T Clements
- Vascular Research Laboratory, Providence Veterans Affairs Medical Center, Providence, Rhode Island
- Department of Surgery, Rhode Island Hospital, Providence, Rhode Island; and
- Cardiovascular Research Center, Rhode Island Hospital, Providence, Rhode Island
| | - Havovi Chichger
- Vascular Research Laboratory, Providence Veterans Affairs Medical Center, Providence, Rhode Island
- Department of Medicine, Warren Alpert Medical School of Brown University, Providence, Rhode Island
| | - Nouaying Kue
- Vascular Research Laboratory, Providence Veterans Affairs Medical Center, Providence, Rhode Island
| | - Ayed Allawzi
- Vascular Research Laboratory, Providence Veterans Affairs Medical Center, Providence, Rhode Island
- Department of Molecular Pharmacology, Physiology, and Biotechnology, Brown University, Providence, Rhode Island
| | - Kelly O'Connell
- Vascular Research Laboratory, Providence Veterans Affairs Medical Center, Providence, Rhode Island
- Department of Medicine, Warren Alpert Medical School of Brown University, Providence, Rhode Island
| | - Euy-Myoung Jeong
- Department of Medicine, Warren Alpert Medical School of Brown University, Providence, Rhode Island
- Cardiovascular Research Center, Rhode Island Hospital, Providence, Rhode Island
| | - Samuel C Dudley
- Department of Medicine, Warren Alpert Medical School of Brown University, Providence, Rhode Island
- Cardiovascular Research Center, Rhode Island Hospital, Providence, Rhode Island
| | - Pavlo Sakhatskyy
- Vascular Research Laboratory, Providence Veterans Affairs Medical Center, Providence, Rhode Island
- Department of Medicine, Warren Alpert Medical School of Brown University, Providence, Rhode Island
| | - Qing Lu
- Vascular Research Laboratory, Providence Veterans Affairs Medical Center, Providence, Rhode Island
- Department of Medicine, Warren Alpert Medical School of Brown University, Providence, Rhode Island
| | - Peng Zhang
- Department of Medicine, Warren Alpert Medical School of Brown University, Providence, Rhode Island
- Cardiovascular Research Center, Rhode Island Hospital, Providence, Rhode Island
| | - Sharon Rounds
- Vascular Research Laboratory, Providence Veterans Affairs Medical Center, Providence, Rhode Island
- Department of Medicine, Warren Alpert Medical School of Brown University, Providence, Rhode Island
| | - Gaurav Choudhary
- Vascular Research Laboratory, Providence Veterans Affairs Medical Center, Providence, Rhode Island;
- Department of Medicine, Warren Alpert Medical School of Brown University, Providence, Rhode Island
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19
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Patel VB, McLean BA, Chen X, Oudit GY. Regulators of G-Protein Signaling 10 and Heart Failure: The Importance of Negative Regulators of Heart Disease. Hypertension 2015; 67:38-40. [PMID: 26573716 DOI: 10.1161/hypertensionaha.115.06109] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Affiliation(s)
- Vaibhav B Patel
- From the Division of Cardiology, Department of Medicine (V.B.P., X.C., G.Y.O.), Mazankowski Alberta Heart Institute (V.B.P., B.A.M., X.C., G.Y.O.), and Department of Physiology (B.A.M., G.Y.O.), University of Alberta, Edmonton, Alberta, Canada
| | - Brent A McLean
- From the Division of Cardiology, Department of Medicine (V.B.P., X.C., G.Y.O.), Mazankowski Alberta Heart Institute (V.B.P., B.A.M., X.C., G.Y.O.), and Department of Physiology (B.A.M., G.Y.O.), University of Alberta, Edmonton, Alberta, Canada
| | - Xueyi Chen
- From the Division of Cardiology, Department of Medicine (V.B.P., X.C., G.Y.O.), Mazankowski Alberta Heart Institute (V.B.P., B.A.M., X.C., G.Y.O.), and Department of Physiology (B.A.M., G.Y.O.), University of Alberta, Edmonton, Alberta, Canada
| | - Gavin Y Oudit
- From the Division of Cardiology, Department of Medicine (V.B.P., X.C., G.Y.O.), Mazankowski Alberta Heart Institute (V.B.P., B.A.M., X.C., G.Y.O.), and Department of Physiology (B.A.M., G.Y.O.), University of Alberta, Edmonton, Alberta, Canada.
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20
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Jiang H, Xie Y, Abel PW, Wolff DW, Toews ML, Panettieri RA, Casale TB, Tu Y. Regulator of G-protein signaling 2 repression exacerbates airway hyper-responsiveness and remodeling in asthma. Am J Respir Cell Mol Biol 2015; 53:42-9. [PMID: 25368964 DOI: 10.1165/rcmb.2014-0319oc] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023] Open
Abstract
G protein-coupled receptors (GPCRs) are important regulators of cell functions in asthma. We recently reported that regulator of G-protein signaling (RGS) 2, a selective modulator of Gq-coupled GPCRs, is a key regulator of airway hyper-responsiveness (AHR), the pathophysiologic hallmark of asthma. Because RGS2 protein levels in airway cells were significantly lower in patients with asthma compared with patients without asthma, we further investigated the potential pathological importance of RGS2 repression in asthma. The human RGS2 gene maps to chromosome 1q31. We first screened patients with asthma for RGS2 gene promoter single-nucleotide polymorphisms (SNPs) and found significant differences in the distribution of two RGS2 SNPs (A638G, rs2746071 and C395G, rs2746072) between patients with asthma and nonasthmatic subjects. These two SNPs are always associated with each other and have the same higher prevalence in patients with asthma (65%) as compared with nonasthmatic subjects (35%). Point mutations corresponding to these SNPs decrease RGS2 promoter activity by 44%. The importance of RGS2 down-regulation was then determined in an acute IL-13 mouse model of asthma. Intranasal administration of IL-13 in mice also decreased RGS2 expression in lungs by ∼50% and caused AHR. Although naive RGS2 knockout (KO) mice exhibit spontaneous AHR, acute IL-13 exposure further increased AHR in RGS2 KO mice. Loss of RGS2 also significantly enhanced IL-13-induced mouse airway remodeling, including peribronchial smooth muscle thickening and fibrosis, without effects on goblet cell hyperplasia or airway inflammation in mice. Thus, genetic variations and increased inflammatory cytokines can lead to RGS2 repression, which exacerbates AHR and airway remodeling in asthma.
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Affiliation(s)
- Haihong Jiang
- 1 Department of Pharmacology, Creighton University School of Medicine, Omaha, Nebraska
| | - Yan Xie
- 1 Department of Pharmacology, Creighton University School of Medicine, Omaha, Nebraska
| | - Peter W Abel
- 1 Department of Pharmacology, Creighton University School of Medicine, Omaha, Nebraska
| | - Dennis W Wolff
- 2 Department of Biomedical Sciences, University of South Carolina School of Medicine at Greenville, Greenville, South Carolina
| | - Myron L Toews
- 3 Department of Pharmacology and Experimental Neuroscience, University of Nebraska Medical Center, Omaha, Nebraska
| | - Reynold A Panettieri
- 4 Pulmonary, Allergy and Critical Care Division, Airways Biology Initiative, University of Pennsylvania, Philadelphia, Pennsylvania; and
| | - Thomas B Casale
- 5 Department of Internal Medicine, University of South Florida School of Medicine, Tampa, Florida
| | - Yaping Tu
- 1 Department of Pharmacology, Creighton University School of Medicine, Omaha, Nebraska
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Nakayama A, Morita H, Nakao T, Yamaguchi T, Sumida T, Ikeda Y, Kumagai H, Motozawa Y, Takahashi T, Imaizumi A, Hashimoto T, Nagai R, Komuro I. A Food-Derived Flavonoid Luteolin Protects against Angiotensin II-Induced Cardiac Remodeling. PLoS One 2015; 10:e0137106. [PMID: 26327560 PMCID: PMC4556625 DOI: 10.1371/journal.pone.0137106] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/11/2015] [Accepted: 08/12/2015] [Indexed: 12/20/2022] Open
Abstract
Oxidative stress has been implicated in cardiac remodeling (cardiac fibrosis and hypertrophy), which impairs cardiac function and metabolism; therefore, it is anticipated antioxidative compounds will have protective properties against cardiac remodeling. Luteolin (3',4',5,7-tetrahydroxyflavone), a widely distributed flavonoid found in many herbal extracts including celery, green pepper, perilla leaves and seeds, and chamomile, is a known to be a potent antioxidant and was previously demonstrated to exert an antifibrotic effect in the lungs and the liver. In this study, we clearly demonstrate that oral pretreatment with the higher-luteolin diet (0.035% (wt/wt)) protected against cardiac fibrosis and hypertrophy as well as a hyperoxidative state in Ang II-infused rats. In cardiac tissue, increased gene expression levels of TGFβ1, CTGF, Nox2, Nox4, ANP, and BNP induced by Ang II were restored by oral pretreatment of this high-luteolin diet. In cultured rat cardiac fibroblasts, H2O2-induced TGFβ1 expression and the phosphorylation of JNK were suppressed by luteolin pretreatment. In conclusion, food-derived luteolin has protective actions against Ang II-induced cardiac remodeling, which could be mediated through attenuation of oxidative stress.
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Affiliation(s)
- Atsuko Nakayama
- Department of Cardiovascular Medicine, Graduate School of Medicine, The University of Tokyo, Tokyo, Japan
| | - Hiroyuki Morita
- Department of Translational Research for Healthcare and Clinical Science, Graduate School of Medicine, The University of Tokyo, Tokyo, Japan
- * E-mail:
| | - Tomoko Nakao
- Department of Cardiovascular Medicine, Graduate School of Medicine, The University of Tokyo, Tokyo, Japan
| | - Toshihiro Yamaguchi
- Department of Cardiovascular Medicine, Graduate School of Medicine, The University of Tokyo, Tokyo, Japan
| | - Tomokazu Sumida
- Department of Cardiovascular Medicine, Graduate School of Medicine, The University of Tokyo, Tokyo, Japan
| | - Yuichi Ikeda
- Department of Cardiovascular Medicine, Graduate School of Medicine, The University of Tokyo, Tokyo, Japan
| | - Hidetoshi Kumagai
- Department of Cardiovascular Medicine, Graduate School of Medicine, The University of Tokyo, Tokyo, Japan
| | - Yoshihiro Motozawa
- Department of Cardiovascular Medicine, Graduate School of Medicine, The University of Tokyo, Tokyo, Japan
| | | | | | | | - Ryozo Nagai
- Department of Cardiovascular Medicine, Graduate School of Medicine, The University of Tokyo, Tokyo, Japan
| | - Issei Komuro
- Department of Cardiovascular Medicine, Graduate School of Medicine, The University of Tokyo, Tokyo, Japan
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22
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Jiang X, Zhang F, Ning Q. Losartan reverses the down-expression of long noncoding RNA-NR024118 and Cdkn1c induced by angiotensin II in adult rat cardiac fibroblasts. ACTA ACUST UNITED AC 2015; 63:122-5. [DOI: 10.1016/j.patbio.2015.04.001] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/10/2015] [Accepted: 04/17/2015] [Indexed: 10/23/2022]
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Osei-Owusu P, Blumer KJ. Regulator of G Protein Signaling 2: A Versatile Regulator of Vascular Function. PROGRESS IN MOLECULAR BIOLOGY AND TRANSLATIONAL SCIENCE 2015; 133:77-92. [PMID: 26123303 DOI: 10.1016/bs.pmbts.2015.02.001] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Abstract
Regulators of G protein signaling (RGS) proteins of the B/R4 family are widely expressed in the cardiovascular system where their role in fine-tuning G protein signaling is critical to maintaining homeostasis. Among members of this family, RGS2 and RGS5 have been shown to play key roles in cardiac and smooth muscle function by tightly regulating signaling pathways that are activated through Gq/11 and Gi/o classes of heterotrimeric G proteins. This chapter reviews accumulating evidence supporting a key role for RGS2 in vascular function and the implication of changes in RGS2 function and/or expression in the pathogenesis of blood pressure disorders, particularly hypertension. With such understanding, RGS2 and the signaling pathways it controls may emerge as novel targets for developing next-generation antihypertensive drugs/agents.
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Affiliation(s)
- Patrick Osei-Owusu
- Department of Pharmacology and Physiology, Drexel University College of Medicine, Philadelphia, Pennsylvania, USA.
| | - Kendall J Blumer
- Department of Cell Biology and Physiology, Washington University School of Medicine, St. Louis, Missouri, USA
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24
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Chichger H, Vang A, O'Connell KA, Zhang P, Mende U, Harrington EO, Choudhary G. PKC δ and βII regulate angiotensin II-mediated fibrosis through p38: a mechanism of RV fibrosis in pulmonary hypertension. Am J Physiol Lung Cell Mol Physiol 2015; 308:L827-36. [PMID: 25659900 DOI: 10.1152/ajplung.00184.2014] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/03/2014] [Accepted: 02/03/2015] [Indexed: 01/26/2023] Open
Abstract
Pulmonary hypertension (PH) eventually leads to right ventricular (RV) fibrosis and dysfunction that is associated with increased morbidity and mortality. Although angiotensin II plays an important role in RV remodeling associated with hypoxic PH, the molecular mechanisms underlying RV fibrosis in PH largely remain unresolved. We hypothesized that PKC-p38 signaling is involved in RV collagen accumulation in PH and in response to angiotensin II stimulation. Adult male Sprague-Dawley rats were exposed to 3 wk of normoxia or hypoxia (10% FiO2 ) as a model of PH. Hypoxic rats developed RV hypertrophy and fibrosis associated with an increase in PKC βII and δ protein expression and p38 dephosphorylation in freshly isolated RV cardiac fibroblasts. Further mechanistic studies were performed in cultured primary cardiac fibroblasts stimulated with angiotensin II, a key activator of ventricular fibrosis in PH. Angiotensin II induced a reduction in p38 phosphorylation that was attenuated following chemical inhibition of PKC βII and δ. Molecular and chemical inhibition of PKC βII and δ abrogated angiotensin II-induced cardiac fibroblast proliferation and collagen deposition in vitro. The effects of PKC inhibition on proliferation and fibrosis were reversed by chemical inhibition of p38. Conversely, constitutive activation of p38 attenuated angiotensin II-induced increase of cardiac fibroblast proliferation and collagen accumulation. PKC βII- and δ-dependent inactivation of p38 regulates cardiac fibroblast proliferation and collagen deposition in response to angiotensin II, which suggests that the PKC-p38 signaling in cardiac fibroblasts may be involved and important in the pathophysiology of RV fibrosis in PH.
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Affiliation(s)
- Havovi Chichger
- Vascular Research Laboratory, Providence Veterans Affairs Medical Center, Providence, Rhode Island; Department of Medicine, Alpert Medical School of Brown University, Providence, Rhode Island
| | - Alexander Vang
- Vascular Research Laboratory, Providence Veterans Affairs Medical Center, Providence, Rhode Island
| | - Kelly A O'Connell
- Vascular Research Laboratory, Providence Veterans Affairs Medical Center, Providence, Rhode Island; Department of Medicine, Alpert Medical School of Brown University, Providence, Rhode Island
| | - Peng Zhang
- Cardiovascular Research Center, Rhode Island Hospital, Providence, Rhode Island; and Department of Medicine, Alpert Medical School of Brown University, Providence, Rhode Island
| | - Ulrike Mende
- Cardiovascular Research Center, Rhode Island Hospital, Providence, Rhode Island; and Department of Medicine, Alpert Medical School of Brown University, Providence, Rhode Island
| | - Elizabeth O Harrington
- Vascular Research Laboratory, Providence Veterans Affairs Medical Center, Providence, Rhode Island; Department of Medicine, Alpert Medical School of Brown University, Providence, Rhode Island
| | - Gaurav Choudhary
- Vascular Research Laboratory, Providence Veterans Affairs Medical Center, Providence, Rhode Island; Department of Medicine, Alpert Medical School of Brown University, Providence, Rhode Island
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25
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Mao Y, Su J, Lei L, Meng L, Qi Y, Huo Y, Tang C. Impaired regulator of G protein signaling 2 transcription facilitates vascular remodeling in injured rat aorta. J Cardiovasc Med (Hagerstown) 2015; 15:572-8. [PMID: 24914635 DOI: 10.2459/jcm.0b013e3283629c30] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Abstract
BACKGROUND The activation of Gq-protein-coupled receptors induces proliferation of vascular smooth muscle cells (VSMCs) proliferation and is involved in vascular remodeling. The regulator of G protein signaling 2 (RGS2), which accelerates the termination of Gq protein signaling, may play a role in vascular remodeling. However, this role remains unclear. METHODS Aortic balloon injury or sham operation was produced in male Wistar rats. Histological examination and gene expression analysis were performed after surgery. In cultured VSMCs after modulation of RGS2 expression, cell proliferation was also evaluated. RESULTS At day 3 after injury, RGS2 transcription was reduced by 52.8% (P <0.05 vs. sham group) with vascular remodeling. In cultured VSMCs stimulated by endothelin-1, phenylephrine or angiotensin II, the proliferation of RGS2 overexpressed cells was significantly inhibited; the proliferation of RGS2 downregulated cells was significantly promoted, compared with that of RGS2 normal cells. Moreover, after incubation with angiotensin II of high concentration (>10 μmol/l) or long term (>8 h), the RGS2 expression was clearly downregulated in cultured VSMCs. Administration of an angiotensin receptor blocker, valsartan (20 mg/kg per day) starting from 1 week preballoon injury to 3 days after injury, restored aortic RGS2 transcription and improved vascular remodeling. CONCLUSION These results suggested that the inhibiting effect of RGS2 on VSMC proliferation is downregulated in vascular remodeling of injured rat aorta, and this effect is likely to be mediated by angiotensin II signaling.
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Affiliation(s)
- Yuanjie Mao
- aDepartment of Cardiology, Peking University First Hospital, Beijing, China bDepartment of Biochemistry, National Cerebral and Cardiovascular Center, Osaka, Japan cCardiology Division, Cardiovascular Research Center, Rhode Island Hospital and Alpert Medical School of Brown University, Providence, Rhode Island, USA dDepartment of Endocrinology, Beijing Aerospace Center Hospital eDepartment of Physiology, School of Basic Medical Sciences, Peking University, Beijing, China
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26
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Zou L, Liu R, Zhang X, Chu R, Dai J, Zhou H, Liu H. Upregulation of regulator of G-protein signaling 2 in the sclera of a form deprivation myopic animal model. Mol Vis 2014; 20:977-87. [PMID: 25018620 PMCID: PMC4087119] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/29/2013] [Accepted: 06/30/2014] [Indexed: 10/25/2022] Open
Abstract
PURPOSE Scleral remodeling is an important mechanism underlying the development of myopia. Atropine, an antagonist of G protein-coupled muscarinic receptors, is currently used as an off-label treatment for myopia. Regulator of G-protein signaling 2 (RGS2) functions as an intracellular selective inhibitor of muscarinic receptors. In this study we measured scleral RGS2 expression and scleral remodeling in an animal model of myopia in the presence or absence of atropine treatment. METHODS GUINEA PIGS WERE ASSIGNED TO FOUR GROUPS: normal (free of form deprivation), form deprivation myopia (FDM) for 4 weeks, FDM treated with saline, and FDM treated with atropine. Biometric measurements were then performed. RGS2 expression levels and scleral remodeling, including scleral thickness and collagen type I expression, were compared among the four groups. RESULTS Compared with normal eyes and contralateral control eyes, the FDM eyes had the most prominent changes in refraction, axial length, and scleral remodeling, indicating myopia. There was no significant difference between control and normal eyes. Hematoxylin and eosin staining showed that the scleral thickness was significantly thinner in the posterior pole region of FDM eyes compared to normal eyes. Real-time PCR and western blot analysis showed a significant decrease in posterior scleral collagen type I mRNA and protein expression in the FDM eyes compared to the normal eyes. The FDM eyes also had increased levels of RGS2 mRNA and protein expression in the sclera. Atropine treatment attenuated the FDM-induced changes in refraction, axial length, and scleral remodeling. Interestingly, atropine treatment significantly increased collagen type I mRNA expression but decreased RGS2 mRNA and protein expression in the sclera of the FDM eyes. CONCLUSIONS We identified a significant RGS2 upregulation and collagen type I downregulation in the sclera of FDM eyes, which could be partially attenuated by atropine treatment. Our data suggest that targeting dysregulated RGS2 may provide a novel strategy for development of therapeutic agents to suppress myopia progression.
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Affiliation(s)
- Leilei Zou
- Department of Ophthalmology, Eye & ENT Hospital, Fudan University, Shanghai,China,Shanghai Key Laboratory of Visual Impairment and Restoration, Fudan University, Shanghai, China,Key Laboratory of Myopia, Ministry of Health PR China, Shanghai, China
| | - Rui Liu
- Department of Ophthalmology, Eye & ENT Hospital, Fudan University, Shanghai,China,Shanghai Key Laboratory of Visual Impairment and Restoration, Fudan University, Shanghai, China,Key Laboratory of Myopia, Ministry of Health PR China, Shanghai, China
| | - Xiaohui Zhang
- Department of Ophthalmology, Eye & ENT Hospital, Fudan University, Shanghai,China,Shanghai Key Laboratory of Visual Impairment and Restoration, Fudan University, Shanghai, China,Key Laboratory of Myopia, Ministry of Health PR China, Shanghai, China
| | - Renyuan Chu
- Department of Ophthalmology, Eye & ENT Hospital, Fudan University, Shanghai,China,Shanghai Key Laboratory of Visual Impairment and Restoration, Fudan University, Shanghai, China,Key Laboratory of Myopia, Ministry of Health PR China, Shanghai, China
| | - Jinhui Dai
- Department of Ophthalmology, Eye & ENT Hospital, Fudan University, Shanghai,China,Shanghai Key Laboratory of Visual Impairment and Restoration, Fudan University, Shanghai, China,Key Laboratory of Myopia, Ministry of Health PR China, Shanghai, China
| | - Hao Zhou
- Department of Ophthalmology, Eye & ENT Hospital, Fudan University, Shanghai,China,Shanghai Key Laboratory of Visual Impairment and Restoration, Fudan University, Shanghai, China,Key Laboratory of Myopia, Ministry of Health PR China, Shanghai, China
| | - Hong Liu
- Department of Ophthalmology, Eye & ENT Hospital, Fudan University, Shanghai,China,Shanghai Key Laboratory of Visual Impairment and Restoration, Fudan University, Shanghai, China,Key Laboratory of Myopia, Ministry of Health PR China, Shanghai, China
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27
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Jang HS, Kim JI, Noh M, Rhee MH, Park KM. Regulator of G protein signaling 2 (RGS2) deficiency accelerates the progression of kidney fibrosis. Biochim Biophys Acta Mol Basis Dis 2014; 1842:1733-41. [PMID: 24973550 DOI: 10.1016/j.bbadis.2014.06.022] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/11/2014] [Revised: 06/02/2014] [Accepted: 06/18/2014] [Indexed: 01/07/2023]
Abstract
The regulator of G protein signaling 2 (RGS2) is a potent negative regulator of Gq protein signals including the angiotensin II (AngII)/AngII receptor signal, which plays a critical role in the progression of fibrosis. However, the role of RGS2 on the progression of kidney fibrosis has not been assessed. Here, we investigated the role of RGS2 in kidney fibrosis induced by unilateral ureteral obstruction (UUO) in mice. UUO resulted in increased expression of RGS2 mRNA and protein in the kidney along with increases of AngII and its type 1 receptor (AT1R) signaling and fibrosis. Furthermore, UUO increased the levels of F4/80, Ly6G, myeloperoxidase, and CXCR4 in the kidneys. RGS2 deficiency significantly enhanced these changes in the kidney. RGS2 deletion in the bone marrow-derived cells by transplanting the bone marrow of RGS2 knock-out mice into wild type mice enhanced UUO-induced kidney fibrosis. Overexpression of RGS2 in HEK293 cells, a human embryonic kidney cell line, and RAW264.7 cells, a monocyte/macrophage line, inhibited the AngII-induced activation of ERK and increase of CXCR4 expression. These findings provide the first evidence that RGS2 negatively regulates the progression of kidney fibrosis following UUO, likely by suppressing fibrogenic and inflammatory responses through the inhibition of AngII/AT1R signaling.
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Affiliation(s)
- Hee-Seong Jang
- Department of Anatomy, Cardiovascular Research Institute, BK21 Plus Biomedical Convergence Program, Kyungpook National University School of Medicine, Daegu 700-422, Republic of Korea
| | - Jee In Kim
- Department of Molecular Medicine and Obesity-Mediated Disease Research Center, College of Medicine, Keimyung University, Daegu, 704-701, Republic of Korea
| | - Mira Noh
- Department of Anatomy, Cardiovascular Research Institute, BK21 Plus Biomedical Convergence Program, Kyungpook National University School of Medicine, Daegu 700-422, Republic of Korea
| | - Man Hee Rhee
- Laboratory of Physiology and Signaling, College of Veterinary Medicine, Kyungpook National University, Daegu 702-701, Republic of Korea
| | - Kwon Moo Park
- Department of Anatomy, Cardiovascular Research Institute, BK21 Plus Biomedical Convergence Program, Kyungpook National University School of Medicine, Daegu 700-422, Republic of Korea.
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28
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Jiang XY, Ning QL. Expression profiling of long noncoding RNAs and the dynamic changes of lncRNA-NR024118 and Cdkn1c in angiotensin II-treated cardiac fibroblasts. INTERNATIONAL JOURNAL OF CLINICAL AND EXPERIMENTAL PATHOLOGY 2014; 7:1325-1336. [PMID: 24817929 PMCID: PMC4014213] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Subscribe] [Scholar Register] [Received: 01/31/2014] [Accepted: 02/15/2014] [Indexed: 06/03/2023]
Abstract
A growing body of evidence shows that long non-coding RNAs (lncRNAs) are involved in multiple human diseases than previously realized. However, no information is available now about lncRNAs in cardiac fibroblasts. The expression profile of lncRNAs was analyzed in Ang II-treated cardiac fibroblasts using lncRNAs arrays. The analysis showed that 282 of 4376 detected lncRNAs demonstrated >2-fold differential expression in response to the treatment with Ang II (100 nm) for 24 h. Among of them, 22 lncRNAs showed a greater than 4-fold changes. Meanwhile, Ang II also induced a widely expression changes in protein-coding genes in cardiac fibroblasts. Quantitative real time PCR confirmed the changes of six lncRNAs (AF159100, BC086588, MRNR026574, MRAK134679, NR024118, AX765700) and mRNAs (IL6, RGS2, PRG4, TIMP1, Cdkn1c, TIMP3, Col I, Col III and Fibronectin) in cardiac fibroblasts. Bioinformatic analysis indicated the process of cell proliferation. Further studies revealed that the down-regulating of Ang II on the expression of lncRNA-NR024118 was time-dependent, that the level of NR024118 was lowest at 24 h and back at 48 h. Ang II also dynamically down regulated the expression of Cdkn1c in cardiac fibroblasts. Ang II at a range from 10(-9) M to 10(-6) M induced a decrease of NR024118 and Cdkn1c in cardiac fibroblasts. In conclusion, the expression profile of lncRNAs was significantly altered in the Ang II-treated cardiac fibroblasts and Ang II dynamically regulated the expression of lncRNA-NR024118 and Cdkn1c in cardiac fibroblasts, indicating the potential role of NR024118 in cardiac fibroblasts.
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MESH Headings
- Angiotensin II/pharmacology
- Animals
- Cells, Cultured
- Cyclin-Dependent Kinase Inhibitor p57/genetics
- Cyclin-Dependent Kinase Inhibitor p57/metabolism
- Dose-Response Relationship, Drug
- Down-Regulation/drug effects
- Fibroblasts/drug effects
- Fibroblasts/metabolism
- Gene Expression Profiling
- Gene Expression Regulation/drug effects
- Male
- Microarray Analysis
- Models, Animal
- Myocytes, Cardiac/drug effects
- Myocytes, Cardiac/metabolism
- RNA, Long Noncoding/genetics
- RNA, Long Noncoding/metabolism
- RNA, Messenger/genetics
- RNA, Messenger/metabolism
- Rats
- Rats, Sprague-Dawley
- Time Factors
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Affiliation(s)
- Xiao-Ying Jiang
- Department of Genetics and Molecular Biology, School of Medicine, Xi'an Jiaotong University Xi'an, 710061, Shaanxi, China
| | - Qi-Lan Ning
- Department of Genetics and Molecular Biology, School of Medicine, Xi'an Jiaotong University Xi'an, 710061, Shaanxi, China
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29
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Chidiac P, Sobiesiak AJ, Lee KN, Gros R, Nguyen CH. The eIF2B-interacting domain of RGS2 protects against GPCR agonist-induced hypertrophy in neonatal rat cardiomyocytes. Cell Signal 2014; 26:1226-34. [PMID: 24576550 DOI: 10.1016/j.cellsig.2014.02.006] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/27/2013] [Revised: 02/05/2014] [Accepted: 02/11/2014] [Indexed: 11/29/2022]
Abstract
The protective effect of Regulator of G protein Signaling 2 (RGS2) in cardiac hypertrophy is thought to occur through its ability to inhibit the chronic GPCR signaling that promotes pathogenic growth both in vivo and in cultured cardiomyocytes. However, RGS2 is known to have additional functions beyond its activity as a GTPase accelerating protein, such as the ability to bind to eukaryotic initiation factor, eIF2B, and inhibit protein synthesis. The RGS2 eIF2B-interacting domain (RGS2(eb)) was examined for its ability to regulate hypertrophy in neonatal ventricular myocytes. Both full-length RGS2 and RGS2(eb) were able to inhibit agonist-induced cardiomyocyte hypertrophy, but RGS2(eb) had no effect on receptor-mediated inositol phosphate production, cAMP production, or ERK 1/2 activation. These results suggest that the protective effects of RGS2 in cardiac hypertrophy may derive at least in part from its ability to govern protein synthesis.
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Affiliation(s)
- Peter Chidiac
- Department of Physiology and Pharmacology, Schulich School of Medicine and Dentistry, University of Western Ontario, London, ON N6A 5C1, Canada
| | - Alina J Sobiesiak
- Department of Physiology and Pharmacology, Schulich School of Medicine and Dentistry, University of Western Ontario, London, ON N6A 5C1, Canada
| | - Katherine N Lee
- Department of Physiology and Pharmacology, Schulich School of Medicine and Dentistry, University of Western Ontario, London, ON N6A 5C1, Canada
| | - Robert Gros
- Department of Physiology and Pharmacology, Schulich School of Medicine and Dentistry, University of Western Ontario, London, ON N6A 5C1, Canada
| | - Chau H Nguyen
- Department of Physiology and Pharmacology, Schulich School of Medicine and Dentistry, University of Western Ontario, London, ON N6A 5C1, Canada; School of Pharmacy, D'Youville College, Buffalo, NY 14201, USA.
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30
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Keinan D, Yang S, Cohen RE, Yuan X, Liu T, Li YP. Role of regulator of G protein signaling proteins in bone. Front Biosci (Landmark Ed) 2014; 19:634-48. [PMID: 24389209 DOI: 10.2741/4232] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
Regulators of G protein signaling (RGS) proteins are a family with more than 30 proteins that all contain an RGS domain. In the past decade, increasing evidence has indicated that RGS proteins play crucial roles in the regulation of G protein coupling receptors (GPCR), G proteins, and calcium signaling during cell proliferation, migration, and differentiation in a variety of tissues. In bone, those proteins modulate bone development and remodeling by influencing various signaling pathways such as GPCR-G protein signaling, Wnt, calcium oscillations and PTH. This review summarizes the recent advances in the understanding of the regulation of RGS gene expression, as well as the functions and mechanisms of RGS proteins, especially in regulating GPCR-G protein signaling, Wnt signaling, calcium oscillations signaling and PTH signaling during bone development and remodeling. This review also highlights the regulation of different RGS proteins in osteoblasts, chondrocytes and osteoclasts. The knowledge from the recent advances of RGS study summarized in the review would provide the insights into new therapies for bone diseases.
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Affiliation(s)
- David Keinan
- Department of Oral Biology, School of Dental Medicine, University at Buffalo, The State University of New York, 3435 Main Street, Buffalo, NY 14214
| | - Shuying Yang
- Department of Oral Biology, School of Dental Medicine, University at Buffalo, The State University of New York, 3435 Main Street, Buffalo, NY 14214
| | - Robert E Cohen
- Department of Periodontics and Endodontics, School of Dental Medicine, University at Buffalo, The State University of New York, 3435 Main Street, Buffalo, NY, 14214, USA
| | - Xue Yuan
- Department of Oral Biology School of Dental Medicine, University at Buffalo, The State University of New York, B36 Foster Hall, Buffalo, NY 14214
| | - Tongjun Liu
- Department of Oral Biology School of Dental Medicine, University at Buffalo, The State University of New York, B36 Foster Hall, Buffalo, NY 14214
| | - Yi-Ping Li
- Department of Pathology, University of Alabama at Birmingham (UAB), 1825 University Blvd, Birmingham AL 35294, USA
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Zhang P, Mende U. Functional role, mechanisms of regulation, and therapeutic potential of regulator of G protein signaling 2 in the heart. Trends Cardiovasc Med 2013; 24:85-93. [PMID: 23962825 DOI: 10.1016/j.tcm.2013.07.002] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/16/2013] [Revised: 07/08/2013] [Accepted: 07/10/2013] [Indexed: 12/22/2022]
Abstract
G protein-mediated signal transduction is essential for the regulation of cardiovascular function, including heart rate, growth, contraction, and vascular tone. Regulators of G protein Signaling (RGS proteins) fine-tune G protein-coupled receptor-induced signaling by regulating its magnitude and duration through direct interaction with the α subunits of heterotrimeric G proteins. Changes in the RGS protein expression and/or function in the heart often lead to pathophysiological changes and are associated with cardiac disease in animals and humans, including hypertrophy, fibrosis development, heart failure, and arrhythmias. This article focuses on Regulator of G protein Signaling 2 (RGS2), which is widely expressed in many tissues and is highly regulated in its expression and function. Most information to date has been obtained in biochemical, cellular, and animal studies, but data from humans is emerging. We review recent advances on the functional role of cardiovascular RGS2 and the mechanisms that determine its signaling selectivity, expression, and functionality. We highlight key unanswered questions and discuss the potential of RGS2 as a therapeutic target.
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Affiliation(s)
- Peng Zhang
- Cardiovascular Research Center, Cardiology Division, Rhode Island Hospital and Alpert Medical School of Brown University, Providence, RI, USA
| | - Ulrike Mende
- Cardiovascular Research Center, Cardiology Division, Rhode Island Hospital and Alpert Medical School of Brown University, Providence, RI, USA.
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32
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Ning Q, Jiang X. Angiotensin II upregulated the expression of microRNA-224 but not microRNA-21 in adult rat cardiac fibroblasts. Biomed Rep 2013; 1:776-780. [PMID: 24649028 DOI: 10.3892/br.2013.144] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/22/2013] [Accepted: 07/05/2013] [Indexed: 02/06/2023] Open
Abstract
The role of microRNA-21 (miRNA-21, miR-21) in cardiac fibrosis remains controversial, while the role of microRNA-224 (miRNA-224, miR-224) in cardiac fibroblasts has not been reported. Angiotensin II (Ang II) is known to play a pivotal role in the pathogenesis of cardiac fibrosis. The aim of this study was to confirm whether the expression of miR-21 and miR-224 is regulated by Ang II in adult rat cardiac fibroblasts. Semi-quantitative reverse transcription-polymerase chain reaction (RT-PCR) and quantitative PCR (qPCR) were performed to measure the levels of miR-21 and miR-224 in Ang II-treated or untreated adult rat cardiac fibroblasts. The RT-PCR, qPCR and previous miRNA array results demonstrated that treatment with Ang II (100 nM) for 24 h did not induce the increase of miR-21 in cardiac fibroblasts, although the level of miR-21 in cardiac fibroblasts was not considered as low. The results of the present study also demonstrated that Ang II significantly upregulated the expression of miR-224 in adult rat cardiac fibroblasts. Bioinformatic analysis revealed that the potential target genes of miR-224 included SMAD4, SMAD5, cyclin-dependent kinase 9 and early growth response 1/2. In previous studies, it was reported that miR-224 was upregulated in tumors by promoting cell proliferation and targeting SMAD4. Those results indicated the potential roles of miR-224 in cardiac fibroblasts and cardiac fibrosis. In conclusion, results of the present study demonstrated that miR-21 was not induced by Ang II, whereas Ang II upregulated miR-224 expression in adult rat cardiac fibroblasts, a finding that may provide a starting point for the investigation of the potential role of miR-224 in cardiac fibrosis.
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Affiliation(s)
- Qilan Ning
- Department of Genetics and Molecular Biology, School of Medicine, Xi'an Jiaotong University, Xi'an, Shaanxi 710061, P.R. China
| | - Xiaoying Jiang
- Department of Genetics and Molecular Biology, School of Medicine, Xi'an Jiaotong University, Xi'an, Shaanxi 710061, P.R. China
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Jiang X, Ning Q, Wang J. Angiotensin II induced differentially expressed microRNAs in adult rat cardiac fibroblasts. J Physiol Sci 2013; 63:31-38. [PMID: 23007623 PMCID: PMC10717151 DOI: 10.1007/s12576-012-0230-y] [Citation(s) in RCA: 42] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/20/2012] [Accepted: 08/24/2012] [Indexed: 10/27/2022]
Abstract
Angiotensin II (Ang II) plays a pivotal role in cardiac fibrosis, and microRNAs (miRNAs) have been shown to participate in diverse pathological processes. Our aim is to identify the Ang II-induced miRNAs in cardiac fibroblasts (CFs). The miRNA array was used to analyze the miRNA expression profile in CFs treated by Ang II and control cells. Stem-loop real-time PCR was performed to re-measure the levels of the differentially expressed miRNAs. Analysis of miRNA arrays showed that 33 miRNAs were differentially expressed (13 up- and 20 downregulated) in response to Ang II (100 nM) for 24 h as compared to control cells. Quantitative PCR revealed that Ang II upregulated the levels of miR-132, -125b-3p and miR-146b but downregulated the levels of miR-300-5p, -204* and miR-181b in CFs. The trend of miRNA change is consistent with microarray and qRT-PCR. Bioinformatic analysis revealed that MMP9 as the target of miR-132, MMP16 as the target of miR-146b and TIMP3 as the target of miR-181b have been listed in the miR database with experimentally validated targets, indicating the potential role of those miRNAs in cardiac fibrosis. Our results demonstrated that we did identify a subset of miRNAs that was differentially expressed in Ang II-treated CFs, which provide a starting point to explore their potential roles in cardiac fibrosis and hypertension.
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Affiliation(s)
- Xiaoying Jiang
- Department of Genetics and Molecular Biology, School of Medicine, Xi'an Jiaotong University, 76 Yanta West Road, Xi'an, 710061, Shaanxi, China.
- NIHR Translational Research Facility in Respiratory Medicine Group, School of Translational Medicine, Stopford Building, University of Manchester, Manchester, M13 9PT, UK.
| | - Qilan Ning
- Department of Genetics and Molecular Biology, School of Medicine, Xi'an Jiaotong University, 76 Yanta West Road, Xi'an, 710061, Shaanxi, China
| | - Juanli Wang
- Department of Genetics and Molecular Biology, School of Medicine, Xi'an Jiaotong University, 76 Yanta West Road, Xi'an, 710061, Shaanxi, China
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Zhang P, Su J, Mende U. Cross talk between cardiac myocytes and fibroblasts: from multiscale investigative approaches to mechanisms and functional consequences. Am J Physiol Heart Circ Physiol 2012; 303:H1385-96. [PMID: 23064834 DOI: 10.1152/ajpheart.01167.2011] [Citation(s) in RCA: 96] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
The heart is comprised of a syncytium of cardiac myocytes (CM) and surrounding nonmyocytes, the majority of which are cardiac fibroblasts (CF). CM and CF are highly interspersed in the myocardium with one CM being surrounded by one or more CF. Bidirectional cross talk between CM and CF plays important roles in determining cardiac mechanical and electrical function in both normal and diseased hearts. Genetically engineered animal models and in vitro studies have provided evidence that CM and CF can regulate each other's function. Their cross talk contributes to structural and electrical remodeling in both atria and ventricles and appears to be involved in the pathogenesis of various heart diseases that lead to heart failure and arrhythmia disorders. Mechanisms of CM-CF cross talk, which are not yet fully understood, include release of paracrine factors, direct cell-cell interactions via gap junctions and potentially adherens junctions and nanotubes, and cell interactions with the extracellular matrix. In this article, we provide an overview of the existing multiscale experimental and computational approaches for the investigation of cross talk between CM and CF and review recent progress in our understanding of the functional consequences and underlying mechanisms. Targeting cross talk between CM and CF could potentially be used therapeutically for the modulation of the cardiac remodeling response in the diseased heart and may lead to new strategies for the treatment of heart failure or rhythm disturbances.
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Affiliation(s)
- P Zhang
- Cardiovascular Research Center, Cardiology Division, Rhode Island Hospital, Providence, USA
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Sjögren B, Parra S, Heath LJ, Atkins KB, Xie ZJ, Neubig RR. Cardiotonic steroids stabilize regulator of G protein signaling 2 protein levels. Mol Pharmacol 2012; 82:500-9. [PMID: 22695717 DOI: 10.1124/mol.112.079293] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022] Open
Abstract
Regulator of G protein signaling 2 (RGS2), a G(q)-specific GTPase-activating protein, is strongly implicated in cardiovascular function. RGS2(-/-) mice are hypertensive and prone to heart failure, and several rare human mutations that accelerate RGS2 degradation have been identified among patients with hypertension. Therefore, pharmacological up-regulation of RGS2 protein levels might be beneficial. We used a β-galactosidase complementation method to screen several thousand compounds with known pharmacological functions for those that increased RGS2 protein levels. Several cardiotonic steroids (CTSs), including ouabain and digoxin, increased RGS2 but not RGS4 protein levels. CTSs increased RGS2 protein levels through a post-transcriptional mechanism, by slowing protein degradation. RGS2 mRNA levels in primary vascular smooth muscle cells were unaffected by CTS treatment, whereas protein levels were increased 2- to 3-fold. Na(+)/K(+)-ATPase was required for the increase in RGS2 protein levels, because the effect was lost in Na(+)/K(+)-ATPase-knockdown cells. Furthermore, we demonstrated that CTS-induced increases in RGS2 levels were functional and reduced receptor-stimulated, G(q)-dependent, extracellular signal-regulated kinase phosphorylation. Finally, we showed that in vivo treatment with digoxin led to increased RGS2 protein levels in heart and kidney. CTS-induced increases in RGS2 protein levels and function might modify several deleterious mechanisms in hypertension and heart failure. This novel CTS mechanism might contribute to the beneficial actions of low-dose digoxin treatment in heart failure. Our results support the concept of small-molecule modulation of RGS2 protein levels as a new strategy for cardiovascular therapy.
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Affiliation(s)
- Benita Sjögren
- Department of Pharmacology, University of Michigan, Ann Arbor, MI 48109, USA
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Kach J, Sethakorn N, Dulin NO. A finer tuning of G-protein signaling through regulated control of RGS proteins. Am J Physiol Heart Circ Physiol 2012; 303:H19-35. [PMID: 22542620 DOI: 10.1152/ajpheart.00764.2011] [Citation(s) in RCA: 40] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/08/2023]
Abstract
Regulators of G-protein signaling (RGS) proteins are GTPase-activating proteins (GAP) for various Gα subunits of heterotrimeric G proteins. Through this mechanism, RGS proteins regulate the magnitude and duration of G-protein-coupled receptor signaling and are often referred to as fine tuners of G-protein signaling. Increasing evidence suggests that RGS proteins themselves are regulated through multiple mechanisms, which may provide an even finer tuning of G-protein signaling and crosstalk between G-protein-coupled receptors and other signaling pathways. This review summarizes the current data on the control of RGS function through regulated expression, intracellular localization, and covalent modification of RGS proteins, as related to cell function and the pathogenesis of diseases.
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Affiliation(s)
- Jacob Kach
- Department of Medicine, University of Chicago, Illinois, 60637, USA
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Stewart A, Huang J, Fisher RA. RGS Proteins in Heart: Brakes on the Vagus. Front Physiol 2012; 3:95. [PMID: 22685433 PMCID: PMC3368389 DOI: 10.3389/fphys.2012.00095] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/29/2011] [Accepted: 03/27/2012] [Indexed: 12/14/2022] Open
Abstract
It has been nearly a century since Otto Loewi discovered that acetylcholine (ACh) release from the vagus produces bradycardia and reduced cardiac contractility. It is now known that parasympathetic control of the heart is mediated by ACh stimulation of G(i/o)-coupled muscarinic M2 receptors, which directly activate G protein-coupled inwardly rectifying potassium (GIRK) channels via Gβγ resulting in membrane hyperpolarization and inhibition of action potential (AP) firing. However, expression of M2R-GIRK signaling components in heterologous systems failed to recapitulate native channel gating kinetics. The missing link was identified with the discovery of regulator of G protein signaling (RGS) proteins, which act as GTPase-activating proteins to accelerate the intrinsic GTPase activity of Gα resulting in termination of Gα- and Gβγ-mediated signaling to downstream effectors. Studies in mice expressing an RGS-insensitive Gα(i2) mutant (G184S) implicated endogenous RGS proteins as key regulators of parasympathetic signaling in heart. Recently, two RGS proteins have been identified as critical regulators of M2R signaling in heart. RGS6 exhibits a uniquely robust expression in heart, especially in sinoatrial (SAN) and atrioventricular nodal regions. Mice lacking RGS6 exhibit increased bradycardia and inhibition of SAN AP firing in response to CCh as well as a loss of rapid activation and deactivation kinetics and current desensitization for ACh-induced GIRK current (I(KACh)). Similar findings were observed in mice lacking RGS4. Thus, dysregulation in RGS protein expression or function may contribute to pathologies involving aberrant electrical activity in cardiac pacemaker cells. Moreover, RGS6 expression was found to be up-regulated in heart under certain pathological conditions, including doxorubicin treatment, which is known to cause life-threatening cardiotoxicity and atrial fibrillation in cancer patients. On the other hand, increased vagal tone may be cardioprotective in heart failure where acetylcholinesterase inhibitors and vagal stimulation have been proposed as potential therapeutics. Together, these studies identify RGS proteins, especially RGS6, as new therapeutic targets for diseases such as sick sinus syndrome or other maladies involving abnormal autonomic control of the heart.
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Affiliation(s)
- Adele Stewart
- Department of Pharmacology, Carver College of Medicine, University of Iowa Iowa City, IA, USA
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Desroches BR, Zhang P, Choi BR, King ME, Maldonado AE, Li W, Rago A, Liu G, Nath N, Hartmann KM, Yang B, Koren G, Morgan JR, Mende U. Functional scaffold-free 3-D cardiac microtissues: a novel model for the investigation of heart cells. Am J Physiol Heart Circ Physiol 2012; 302:H2031-42. [PMID: 22427522 DOI: 10.1152/ajpheart.00743.2011] [Citation(s) in RCA: 69] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/19/2023]
Abstract
To bridge the gap between two-dimensional cell culture and tissue, various three-dimensional (3-D) cell culture approaches have been developed for the investigation of cardiac myocytes (CMs) and cardiac fibroblasts (CFs). However, several limitations still exist. This study was designed to develop a cardiac 3-D culture model with a scaffold-free technology that can easily and inexpensively generate large numbers of microtissues with cellular distribution and functional behavior similar to cardiac tissue. Using micromolded nonadhesive agarose hydrogels containing 822 concave recesses (800 μm deep × 400 μm wide), we demonstrated that neonatal rat ventricular CMs and CFs alone or in combination self-assembled into viable (Live/Dead stain) spherical-shaped microtissues. Importantly, when seeded simultaneously or sequentially, CMs and CFs self-sorted to be interspersed, reminiscent of their myocardial distribution, as shown by cell type-specific CellTracker or antibody labeling. Microelectrode recordings and optical mapping revealed characteristic triangular action potentials (APs) with a resting membrane potential of -66 ± 7 mV (n = 4) in spontaneously contracting CM microtissues. Under pacing, optically mapped AP duration at 90% repolarization and conduction velocity were 100 ± 30 ms and 18.0 ± 1.9 cm/s, respectively (n = 5 each). The presence of CFs led to a twofold AP prolongation in heterogenous microtissues (CM-to-CF ratio of 1:1). Importantly, Ba(2+)-sensitive inward rectifier K(+) currents and Ca(2+)-handling proteins, including sarco(endo)plasmic reticulum Ca(2+)-ATPase 2a, were detected in CM-containing microtissues. Furthermore, cell type-specific adenoviral gene transfer was achieved, with no impact on microtissue formation or cell viability. In conclusion, we developed a novel scaffold-free cardiac 3-D culture model with several advancements for the investigation of CM and CF function and cross-regulation.
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Affiliation(s)
- B R Desroches
- Cardiovascular Research Center, Cardiology Division, Rhode Island Hospital, Providence, RI 02903, USA
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Abstract
Signal transduction through G-protein-coupled receptors (GPCRs) is central for the regulation of virtually all cellular functions and has been widely implicated in human disease. Regulators of G-protein signaling (RGS proteins) belong to a diverse protein family that was originally discovered for their ability to accelerate signal termination in response to GPCR stimulation, thereby reducing the amplitude and duration of GPCR effects. All RGS proteins share a common RGS domain that interacts with G protein α subunits and mediates their biological regulation of GPCR signaling. However, RGS proteins differ widely in size and the organization of their sequences flanking the RGS domain, which contain several additional functional domains that facilitate protein-protein (or protein-lipid) interactions. RGS proteins are subject to posttranslational modifications, and, in addition, their expression, activity, and subcellular localization can be dynamically regulated. Thus, there exists a wide array of mechanisms that facilitate their proper function as modulators and integrators of G-protein signaling. Several RGS proteins have been implicated in the cardiac remodeling response and heart rate regulation, and changes in RGS protein expression and/or function are believed to participate in the pathophysiology of cardiac hypertrophy, failure and arrhythmias as well as hypertension. This review is based on recent advances in our understanding of the expression pattern, regulation, and functional role of canonical RGS proteins, with a special focus on the healthy heart and the diseased heart. In addition, we discuss their potential and promise as therapeutic targets as well as strategies to modulate their expression and function.
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Affiliation(s)
- Peng Zhang
- Cardiovascular Research Center, Rhode Island Hospital and Alpert Medical School of Brown University, 1 Hoppin St, Providence, RI 02903, USA
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