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Son CO, Hong MH, Kim HY, Han BH, Seo CS, Lee HS, Yoon JJ, Kang DG. Sibjotang Protects against Cardiac Hypertrophy In Vitro and In Vivo. Life (Basel) 2023; 13:2307. [PMID: 38137908 PMCID: PMC10744393 DOI: 10.3390/life13122307] [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: 09/04/2023] [Revised: 10/19/2023] [Accepted: 10/26/2023] [Indexed: 12/24/2023] Open
Abstract
Cardiac hypertrophy is developed by various diseases such as myocardial infarction, valve diseases, hypertension, and aortic stenosis. Sibjotang (, Shizaotang, SJT), a classic formula in Korean traditional medicine, has been shown to modulate the equilibrium of body fluids and blood pressure. This research study sought to explore the impact and underlying process of Sibjotang on cardiotoxicity induced by DOX in H9c2 cells. In vitro, H9c2 cells were induced by DOX (1 μM) in the presence or absence of SJT (1-5 μg/mL) and incubated for 24 h. In vivo, SJT was administrated to isoproterenol (ISO)-induced cardiac hypertrophy mice (n = 8) at 100 mg/kg/day concentrations. Immunofluorescence staining revealed that SJT mitigated the enlargement of H9c2 cells caused by DOX in a dose-dependent way. Using SJT as a pretreatment notably suppressed the rise in cardiac hypertrophic marker levels induced by DOX. SJT inhibited the DOX-induced ERK1/2 and p38 MAPK signaling pathways. In addition, SJT significantly decreased the expression of the hypertrophy-associated transcription factor GATA binding factor 4 (GATA 4) induced by DOX. SJT also decreased hypertrophy-associated calcineurin and NFAT protein levels. Pretreatment with SJT significantly attenuated DOX-induced apoptosis-associated proteins such as Bax, caspase-3, and caspase-9 without affecting cell viability. In addition, the results of the in vivo study indicated that SJT significantly reduced the left ventricle/body weight ratio level. Administration of SJT reduced the expression of hypertrophy markers, such as ANP and BNP. These results suggest that SJT attenuates cardiac hypertrophy and heart failure induced by DOX or ISO through the inhibition of the calcineurin/NFAT/GATA4 pathway. Therefore, SJT may be a potential treatment for the prevention and treatment of cardiac hypertrophy that leads to heart failure.
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Affiliation(s)
- Chan-Ok Son
- Department of Ophthalmology, Konkuk University School of Medicine, Gwangjin-gu, Seoul 05030, Republic of Korea;
| | - Mi-Hyeon Hong
- Hanbang Cardio-Renal Syndrome Research Center, Wonkwang University, 460, Iksan-daero, Iksan, Jeonbuk 54538, Republic of Korea; (M.-H.H.); (H.-Y.K.); (B.-H.H.); (H.-S.L.)
| | - Hye-Yoom Kim
- Hanbang Cardio-Renal Syndrome Research Center, Wonkwang University, 460, Iksan-daero, Iksan, Jeonbuk 54538, Republic of Korea; (M.-H.H.); (H.-Y.K.); (B.-H.H.); (H.-S.L.)
| | - Byung-Hyuk Han
- Hanbang Cardio-Renal Syndrome Research Center, Wonkwang University, 460, Iksan-daero, Iksan, Jeonbuk 54538, Republic of Korea; (M.-H.H.); (H.-Y.K.); (B.-H.H.); (H.-S.L.)
| | - Chang-Seob Seo
- KM Science Research Division, Korea Institute of Oriental Medicine, Daejeon 34054, Republic of Korea;
| | - Ho-Sub Lee
- Hanbang Cardio-Renal Syndrome Research Center, Wonkwang University, 460, Iksan-daero, Iksan, Jeonbuk 54538, Republic of Korea; (M.-H.H.); (H.-Y.K.); (B.-H.H.); (H.-S.L.)
| | - Jung-Joo Yoon
- Hanbang Cardio-Renal Syndrome Research Center, Wonkwang University, 460, Iksan-daero, Iksan, Jeonbuk 54538, Republic of Korea; (M.-H.H.); (H.-Y.K.); (B.-H.H.); (H.-S.L.)
| | - Dae-Gill Kang
- Hanbang Cardio-Renal Syndrome Research Center, Wonkwang University, 460, Iksan-daero, Iksan, Jeonbuk 54538, Republic of Korea; (M.-H.H.); (H.-Y.K.); (B.-H.H.); (H.-S.L.)
- College of Oriental Medicine, Wonkwang University, 460, Iksan-daero, Iksan, Jeonbuk 54538, Republic of Korea
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Free fatty acid receptor 2 promotes cardiomyocyte hypertrophy by activating STAT3 and GATA4. FOOD SCIENCE AND HUMAN WELLNESS 2022. [DOI: 10.1016/j.fshw.2021.11.022] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
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Takano APC, Senger N, Barreto-Chaves MLM. The endocrinological component and signaling pathways associated to cardiac hypertrophy. Mol Cell Endocrinol 2020; 518:110972. [PMID: 32777452 DOI: 10.1016/j.mce.2020.110972] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/07/2020] [Revised: 07/14/2020] [Accepted: 07/30/2020] [Indexed: 02/06/2023]
Abstract
Although myocardial growth corresponds to an adaptive response to maintain cardiac contractile function, the cardiac hypertrophy is a condition that occurs in many cardiovascular diseases and typically precedes the onset of heart failure. Different endocrine factors such as thyroid hormones, insulin, insulin-like growth factor 1 (IGF-1), angiotensin II (Ang II), endothelin (ET-1), catecholamines, estrogen, among others represent important stimuli to cardiomyocyte hypertrophy. Thus, numerous endocrine disorders manifested as changes in the local environment or multiple organ systems are especially important in the context of progression from cardiac hypertrophy to heart failure. Based on that information, this review summarizes experimental findings regarding the influence of such hormones upon signalling pathways associated with cardiac hypertrophy. Understanding mechanisms through which hormones differentially regulate cardiac hypertrophy could open ways to obtain therapeutic approaches that contribute to prevent or delay the onset of heart failure related to endocrine diseases.
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Affiliation(s)
| | - Nathalia Senger
- Department of Anatomy, Institute of Biomedical Sciences, University of Sao Paulo, São Paulo, Brazil
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Cardiac Fibroblast p38 MAPK: A Critical Regulator of Myocardial Remodeling. J Cardiovasc Dev Dis 2019; 6:jcdd6030027. [PMID: 31394846 PMCID: PMC6787752 DOI: 10.3390/jcdd6030027] [Citation(s) in RCA: 51] [Impact Index Per Article: 10.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/23/2019] [Revised: 08/02/2019] [Accepted: 08/06/2019] [Indexed: 12/15/2022] Open
Abstract
The cardiac fibroblast is a remarkably versatile cell type that coordinates inflammatory, fibrotic and hypertrophic responses in the heart through a complex array of intracellular and intercellular signaling mechanisms. One important signaling node that has been identified involves p38 MAPK; a family of kinases activated in response to stress and inflammatory stimuli that modulates multiple aspects of cardiac fibroblast function, including inflammatory responses, myofibroblast differentiation, extracellular matrix turnover and the paracrine induction of cardiomyocyte hypertrophy. This review explores the emerging importance of the p38 MAPK pathway in cardiac fibroblasts, describes the molecular mechanisms by which it regulates the expression of key genes, and highlights its potential as a therapeutic target for reducing adverse myocardial remodeling.
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Ben P, Hu M, Wu H, Zhang Z, Gao Y, Luo L, Yin Z. L-Theanine Down-Regulates the JAK/STAT3 Pathway to Attenuate the Proliferation and Migration of Vascular Smooth Muscle Cells Induced by Angiotensin II. Biol Pharm Bull 2018; 41:1678-1684. [DOI: 10.1248/bpb.b18-00387] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Affiliation(s)
- Peiling Ben
- Department of Medicine, Chuzhou City Vocation College
| | - Monong Hu
- Department of Medicine, Chuzhou City Vocation College
| | - Huizhen Wu
- Department of Medicine, Chuzhou City Vocation College
| | - Zhengping Zhang
- State Key Laboratory of Pharmaceutical Biotechnology, School of Life Sciences, Nanjing University
| | - Yanhong Gao
- Jiangsu Province Key Laboratory for Molecular and Medical Biotechnology, College of Life Sciences, Nanjing Normal University
| | - Lan Luo
- State Key Laboratory of Pharmaceutical Biotechnology, School of Life Sciences, Nanjing University
| | - Zhimin Yin
- Jiangsu Province Key Laboratory for Molecular and Medical Biotechnology, College of Life Sciences, Nanjing Normal University
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Nakai K, Kawato T, Morita T, Yamazaki Y, Tanaka H, Tonogi M, Oki H, Maeno M. Angiotensin II suppresses osteoblastic differentiation and mineralized nodule formation via AT1 receptor in ROS17/2.8 cells. Arch Med Sci 2015; 11:628-37. [PMID: 26170858 PMCID: PMC4495158 DOI: 10.5114/aoms.2015.52369] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/19/2013] [Revised: 07/02/2013] [Accepted: 07/19/2013] [Indexed: 12/18/2022] Open
Abstract
INTRODUCTION Angiotensin II (Ang II) not only regulates systemic blood pressure through a vasoconstrictive effect, but also promotes bone resorption. We recently reported that Ang II (10(-6) M) stimulated the production of matrix metalloproteinases via the AT1 receptor in osteoblastic ROS17/2.8 cells, but suppressed alkaline phosphatase activity. However, the roles of Ang II in osteoblastic differentiation and the function of osteogenesis in osteoblasts are unclear. Therefore, we examined the effect of Ang II on the expression of osteogenesis-related transcription factors and extracellular matrix (ECM) proteins, as well as mineralized nodule formation in ROS17/2.8 cells. MATERIAL AND METHODS ROS17/2.8 cells were cultured with 0 (control) or 10(-6) M Ang II in the presence or absence of the AT1 receptor blocker losartan. Mineralized nodule formation was detected by Alizarin Red staining. Gene and protein expression levels of transcription factors and ECM proteins were determined using real-time PCR and Western blotting, respectively. RESULTS Runx2, Msx2, and osteocalcin expression significantly decreased with Ang II compared to the control, whereas AJ18 expression significantly increased. Osterix, Dlx5, type I collagen, bone sialoprotein, and osteopontin expression was unaffected. Mineralized nodule formation and calcium content in mineralized nodules decreased with Ang II. Losartan blocked suppressive or stimulatory effects of Ang II on Runx2, Msx2, osteocalcin, and AJ18 expression. CONCLUSIONS These results suggest that Ang II suppresses osteoblastic differentiation by altering the expression of osteogenesis-related transcription factors via the AT1 receptor and the function of osteogenesis in ROS17/2.8 cells.
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Affiliation(s)
- Kumiko Nakai
- Division of Oral Health Sciences, Nihon University Graduate School of Dentistry, Tokyo, Japan
| | - Takayuki Kawato
- Department of Oral Health Sciences, Nihon University School of Dentistry, Tokyo, Japan
- Division of Functional Morphology, Dental Research Center, Nihon University School of Dentistry, Tokyo, Japan
| | - Toyoko Morita
- Department of Oral Health Sciences, Nihon University School of Dentistry, Tokyo, Japan
- The Lion Foundation for Dental Health, Tokyo, Japan
| | | | - Hideki Tanaka
- Department of Oral Health Sciences, Nihon University School of Dentistry, Tokyo, Japan
- Division of Functional Morphology, Dental Research Center, Nihon University School of Dentistry, Tokyo, Japan
| | - Morio Tonogi
- Department of Oral and Maxillofacial Surgery, Nihon University School of Dentistry, Tokyo, Japan
| | - Hidero Oki
- Department of Oral and Maxillofacial Surgery, Nihon University School of Dentistry, Tokyo, Japan
- Division of Immunology and Pathobiology, Dental Research Center, Nihon University School of Dentistry, Tokyo, Japan
| | - Masao Maeno
- Department of Oral Health Sciences, Nihon University School of Dentistry, Tokyo, Japan
- Division of Functional Morphology, Dental Research Center, Nihon University School of Dentistry, Tokyo, Japan
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Chao CM, El Agha E, Tiozzo C, Minoo P, Bellusci S. A breath of fresh air on the mesenchyme: impact of impaired mesenchymal development on the pathogenesis of bronchopulmonary dysplasia. Front Med (Lausanne) 2015; 2:27. [PMID: 25973420 PMCID: PMC4412070 DOI: 10.3389/fmed.2015.00027] [Citation(s) in RCA: 47] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/06/2015] [Accepted: 04/11/2015] [Indexed: 12/14/2022] Open
Abstract
The early mouse embryonic lung, with its robust and apparently reproducible branching pattern, has always fascinated developmental biologists. They have extensively used this embryonic organ to decipher the role of mammalian orthologs of Drosophila genes in controlling the process of branching morphogenesis. During the early pseudoglandular stage, the embryonic lung is formed mostly of tubes that keep on branching. As the branching takes place, progenitor cells located in niches are also amplified and progressively differentiate along the proximo-distal and dorso-ventral axes of the lung. Such elaborate processes require coordinated interactions between signaling molecules arising from and acting on four functional domains: the epithelium, the endothelium, the mesenchyme, and the mesothelium. These interactions, quite well characterized in a relatively simple lung tubular structure remain elusive in the successive developmental and postnatal phases of lung development. In particular, a better understanding of the process underlying the formation of secondary septa, key structural units characteristic of the alveologenesis phase, is still missing. This structure is critical for the formation of a mature lung as it allows the subdivision of saccules in the early neonatal lung into alveoli, thereby considerably expanding the respiratory surface. Interruption of alveologenesis in preterm neonates underlies the pathogenesis of chronic neonatal lung disease known as bronchopulmonary dysplasia. De novo formation of secondary septae appears also to be the limiting factor for lung regeneration in human patients with emphysema. In this review, we will therefore focus on what is known in terms of interactions between the different lung compartments and discuss the current understanding of mesenchymal cell lineage formation in the lung, focusing on secondary septae formation.
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Affiliation(s)
- Cho-Ming Chao
- Department of General Pediatrics and Neonatology, University Children's Hospital Giessen , Giessen , Germany ; Department of Internal Medicine II, Universities of Giessen and Marburg Lung Center , Giessen , Germany ; Member of the German Center for Lung Research (DZL) , Giessen , Germany
| | - Elie El Agha
- Department of Internal Medicine II, Universities of Giessen and Marburg Lung Center , Giessen , Germany ; Member of the German Center for Lung Research (DZL) , Giessen , Germany
| | - Caterina Tiozzo
- Division of Neonatology, Department of Pediatrics, Columbia University , New York, NY , USA
| | - Parviz Minoo
- Division of Newborn Medicine, Department of Pediatrics, Children's Hospital Los Angeles, University of Southern California , Los Angeles, CA , USA
| | - Saverio Bellusci
- Department of Internal Medicine II, Universities of Giessen and Marburg Lung Center , Giessen , Germany ; Member of the German Center for Lung Research (DZL) , Giessen , Germany ; Saban Research Institute, Childrens Hospital Los Angeles, University of Southern California , Los Angeles, CA , USA ; Kazan Federal University , Kazan , Russia
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Song T, Wang W, Xu J, Zhao D, Dong Q, Li L, Yang X, Duan X, Liang Y, Xiao Y, Wang J, He J, Tang M, Wang J, Luo J. Fibroblast growth factor 2 inhibits bone morphogenetic protein 9-induced osteogenic differentiation of mesenchymal stem cells by repressing Smads signaling and subsequently reducing Smads dependent up-regulation of ALK1 and ALK2. Int J Biochem Cell Biol 2013; 45:1639-46. [PMID: 23680673 DOI: 10.1016/j.biocel.2013.05.005] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/14/2013] [Revised: 04/10/2013] [Accepted: 05/06/2013] [Indexed: 12/24/2022]
Abstract
Understanding the interactions between growth factors and bone morphogenic proteins (BMPs) signaling remains a crucial issue to optimize the use of mesenchymal stem cells (MSCs) and BMPs in bone tissue engineering. BMP9 is highly capable of promoting osteogenic differentiation of MSCs. Fibroblast growth factor 2 (FGF2) is abundantly secreted during the healing process of fractures or in surgery bone sites. Herein, we explore the detail effect of FGF2 on BMP9-induced osteogenic differentiation of MSCs. It was found that FGF2 inhibited BMP9-induced osteogenic differentiation by blocking BMP9-induced Smads signaling and subsequently reducing Smads dependent up-regulation of ALK1 and ALK2 in MSCs. This effect was rescued by exogenous expression of ALK1 and ALK2, which are proved to be receptors for BMP9. Our results discovered a clue to explain the mechanism involved in the inhibitory effect of FGF2 on BMP9-induced osteogenic differentiation of MSCs. This crosstalk between FGF2 and BMP9 should be emphasized in the future use of BMP9 in therapeutic purpose of fracture repair.
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Affiliation(s)
- Tao Song
- Key Laboratory of Diagnostic Medicine Designated by the Chinese Ministry of Education, Chongqing Medical University, Chongqing 40016, PR China
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Yu L, Li M, She T, Shi C, Meng W, Wang B, Cheng M. Endothelin-1 stimulates the expression of L-type Ca2+ channels in neonatal rat cardiomyocytes via the extracellular signal-regulated kinase 1/2 pathway. J Membr Biol 2013; 246:343-53. [PMID: 23546014 DOI: 10.1007/s00232-013-9538-7] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/06/2012] [Accepted: 03/16/2013] [Indexed: 01/07/2023]
Abstract
The cardiac L-type Ca(2+) channel current (I(Ca,L)) plays an important role in controlling both cardiac excitability and excitation-contraction coupling and is involved in the electrical remodeling during postnatal heart development and cardiac hypertrophy. However, the possible role of endothelin-1 (ET-1) in the electrical remodeling of postnatal and diseased hearts remains unclear. Therefore, the present study was designed to investigate the transcriptional regulation of I(Ca,L) mediated by ET-1 in neonatal rat ventricular myocytes using the whole-cell patch-clamp technique, quantitative RT-PCR and Western blotting. Furthermore, we determined whether the extracellular signal-regulated kinase 1/2 (ERK1/2) pathway is involved. ET-1 increased I(Ca,L) density without altering its voltage dependence of activation and inactivation. In line with the absence of functional changes, ET-1 increased L-type Ca(2+) channel pore-forming α1C-subunit mRNA and protein levels without affecting the mRNA expression of auxiliary β- and α2/δ-subunits. Furthermore, an actinomycin D chase experiment revealed that ET-1 did not alter α1C-subunit mRNA stability. These effects of ET-1 were inhibited by the ETA receptor antagonist BQ-123 but not the ETB receptor antagonist BQ-788. Moreover, the effects of ET-1 on I(Ca,L) and α1C-subunit expression were abolished by the ERK1/2 inhibitor (PD98059) but not by the p38 MAPK inhibitor (SB203580) or the c-Jun N-terminal kinase inhibitor (SP600125). These findings indicate that ET-1 increased the transcription of L-type Ca(2+) channel in cardiomyocytes via activation of ERK1/2 through the ETA receptor, which may contribute to the electrical remodeling of heart during postnatal development and cardiac hypertrophy.
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Affiliation(s)
- Liangzhu Yu
- Hubei Province Key Laboratory on Cardiovascular, Cerebrovascular, and Metabolic Disorders, Hubei University of Science and Technology, Xianning, Peoples Republic of China.
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Ma L, Hua J, He L, Li Q, Zhou J, Yu J. Anti-fibrotic effect of Aliskiren in rats with deoxycorticosterone induced myocardial fibrosis and its potential mechanism. Bosn J Basic Med Sci 2012; 12:69-73. [PMID: 22642589 DOI: 10.17305/bjbms.2012.2498] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022] Open
Abstract
The objective of our study was to investigate the effect of Aliskiren, a renin inhibitor, on the deoxycorticosterone (DOCA) induced myocardial fibrosis in a rat model and its underlying mechanism. A total of 45 Sprague-Dawley (SD) rats underwent right nephrectomy and were randomly assigned into 3 groups: control group (CON group: silicone tube was embedded subcutaneously); DOCA treated group (DOC group: 200 mg of DOCA was subcutaneously administered); DOCA and Aliskiren (ALI) treated group (ALI group: 200 mg of DOCA and 50 mg/kg/d ALI were subcutaneously and intragastrically given, respectively). Treatment was done for 4 weeks. Sirius red staining was employed to detect the expression of myocardial collagen, and the myocardial collagen volume fraction (CVF) and perivascular collagen volume area (PVCA) were calculated. Radioimmunoassay was carried out to measure the renin activity (RA) and content of angiotensin II (Ang II) in the plasma and ventricle. Western blot assay was done to detect the expressions of extracellular signal-regulated kinase 1/2 (ERK1/2), phosphorylated ERK1/2 (PERK1/2) and matrix metalloproteinase 9 (MMP-9). In the DOC group and ALI group, the CVF and PVCA were significantly increased; the RA and Ang II levels in the plasma and ventricle were remarkably lowered when compared with the CON group. The RA and Ang II levels in the ventricle of the ALI group were significantly lower than those in the DOC group. Moreover, the expressions of ERK1/2, PERK1/2 and MMP9 were the lowest in the CON group, but those in the ALI group were significantly reduced as compared to the DOC group. ALI can inhibit the DOCA induced myocardial fibrosis independent of its pressure-lowing effect, which may be related to the suppression of RA and Ang II production, inhibition of ERK1/2 phosphorylation and MMP9 expression in the heart.
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Affiliation(s)
- Likun Ma
- Department of Cardiology, Anhui Provincial Hospital, No 17 Lujiang Road, Hefei 230001, China.
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Kim JH, Jiang S, Elwell CA, Engel JN. Chlamydia trachomatis co-opts the FGF2 signaling pathway to enhance infection. PLoS Pathog 2011; 7:e1002285. [PMID: 21998584 PMCID: PMC3188521 DOI: 10.1371/journal.ppat.1002285] [Citation(s) in RCA: 49] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/23/2010] [Accepted: 08/10/2011] [Indexed: 12/12/2022] Open
Abstract
The molecular details of Chlamydia trachomatis binding, entry, and spread are incompletely understood, but heparan sulfate proteoglycans (HSPGs) play a role in the initial binding steps. As cell surface HSPGs facilitate the interactions of many growth factors with their receptors, we investigated the role of HSPG-dependent growth factors in C. trachomatis infection. Here, we report a novel finding that Fibroblast Growth Factor 2 (FGF2) is necessary and sufficient to enhance C. trachomatis binding to host cells in an HSPG-dependent manner. FGF2 binds directly to elementary bodies (EBs) where it may function as a bridging molecule to facilitate interactions of EBs with the FGF receptor (FGFR) on the cell surface. Upon EB binding, FGFR is activated locally and contributes to bacterial uptake into non-phagocytic cells. We further show that C. trachomatis infection stimulates fgf2 transcription and enhances production and release of FGF2 through a pathway that requires bacterial protein synthesis and activation of the Erk1/2 signaling pathway but that is independent of FGFR activation. Intracellular replication of the bacteria results in host proteosome-mediated degradation of the high molecular weight (HMW) isoforms of FGF2 and increased amounts of the low molecular weight (LMW) isoforms, which are released upon host cell death. Finally, we demonstrate the in vivo relevance of these findings by showing that conditioned medium from C. trachomatis infected cells is enriched for LMW FGF2, accounting for its ability to enhance C. trachomatis infectivity in additional rounds of infection. Together, these results demonstrate that C. trachomatis utilizes multiple mechanisms to co-opt the host cell FGF2 pathway to enhance bacterial infection and spread. Chlamydia trachomatis is an obligate intracellular bacterium that is an important cause of human disease, including sexually transmitted diseases and acquired blindness in developing countries. The inability to carry out conventional genetic manipulations limits our understanding of the mechanisms of C. trachomatis binding, entry, and spread. Previous studies have shown that heparan sulfate proteoglycans (HSPGs) play a role in early binding events. As cell surface HSPGs facilitate the interactions of many growth factors with their receptors, we investigated whether HSPG-associated growth factors affect C. trachomatis binding or entry. Here, we report the novel finding that Fibroblast Growth Factor 2 (FGF2), a ubiquitously expressed growth factor, enhances C. trachomatis binding to host cells in an HSPG-dependent manner. Furthermore, C. trachomatis infection stimulates production and release of FGF2 through distinct signaling pathways. Released FGF2 is sufficient to enhance the subsequent rounds of infection. Together, these results demonstrate that C. trachomatis utilizes multiple mechanisms to co-opt the host cell FGF2 pathway that sets up a positive feedback loop to enhance bacterial infection and spread.
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Affiliation(s)
- Jung Hwa Kim
- Department of Medicine, University of California San Francisco, San Francisco, California, United States of America
- Microbial Pathogenesis and Host Defense Program, University of California San Francisco, San Francisco, California, United States of America
| | - Shaobo Jiang
- Department of Medicine, University of California San Francisco, San Francisco, California, United States of America
- Microbial Pathogenesis and Host Defense Program, University of California San Francisco, San Francisco, California, United States of America
| | - Cherilyn A. Elwell
- Department of Medicine, University of California San Francisco, San Francisco, California, United States of America
- Microbial Pathogenesis and Host Defense Program, University of California San Francisco, San Francisco, California, United States of America
| | - Joanne N. Engel
- Department of Medicine, University of California San Francisco, San Francisco, California, United States of America
- Microbial Pathogenesis and Host Defense Program, University of California San Francisco, San Francisco, California, United States of America
- Department of Microbiology and Immunology, University of California San Francisco, San Francisco, California, United States of America
- * E-mail:
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