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TIMP-1 ACTIVATES A UNIQUE CARDIAC STEM CELL POPULATION, CD63+ve/C-KIT+ve, THEREBY ENHANCING CARDIAC DIFFERENTIATION, AND PROTECTS THE HEART FROM ADVERSE CARDIAC REMODELING FOLLOWING MYOCARDIAL INFARCTION

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Date Issued:
2015
Abstract/Description:
We previously demonstrated that embryonic stem (ES) cells over-expressing tissue inhibitor of metalloproteinase-1 (TIMP-1) have increased potential to engraft and differentiate into cardiac myocytes following transplantation into the infarcted heart. However, the ability of TIMP-1 to activate endogenous stem cells and enhance their differentiation into cardiac regenerative cell types is still unknown. We postulate that TIMP-1 may additionally activate a stem cell population that enhances cardiac cell type differentiation in the infarcted myocardium. To prove this hypothesis, we isolated c-kit+ve cells from four weeks old C57BL/6 mice and cultured them in vitro in presence of ES conditioned media (ESCM), ES-TIMP-1-CM or TIMP-1. Our immunostaining data validate the existence of a novel CD63+ve/c-kit+ve cells. When treated with TIMP-1, these cells showed significantly (p(<)0.05) increased proliferation and differentiation into cardiac myocytes, vascular smooth muscle cells, and endothelial cells. Western blot analysis revealed significantly (p(<)0.05) increased expression of CD63, phosphorylated and total ?-catenin proteins. Furthermore, our RT-PCR data showed increased cardiac gene expression (GATA-4, Mef2C, and Nkx-2.5) when compared to ESCM and control cells. Based on the in vitro findings, we investigated the effect of intramyocardial delivery of TIMP-1 on endogenous CD63+ve/c-kit+ve cells following myocardial infarction (MI). C57BL/6 and TIMP-1 KO mice underwent coronary artery ligation followed by intramyocardial delivery of 20(&)#181;l of culture media (CC), ESCM, ES-TIMP-1-CM or TIMP-1. Subsequent immunohistochemistry analysis demonstrated the presence of a CD63+ve/c-kit+ve cell population within the peri-infarct area and confirmed intramyocardial delivery of ES-TIMP-1-CM or TIMP-1 significantly (p(<)0.05) enhanced their proliferation. Percentage of CD63+ve/c-kit+ve cells was significantly (p(<)0.05) lower in TIMP-1 KO mice compared to C57BL/6 animals. RT-PCR analysis revealed TIMP-1 KO animals expressed significantly less CD63 and TIMP-1 mRNAs compared to C57BL/6 mice. Activated CD63+ve/c-kit+ve cells were also able to differentiate into major cardiac cell types as previously shown in vitro. The differentiation potential of these cells was however higher in C57BL/6 mice compared to TIMP-1 KO mice. We also demonstrate that CD63+ve/c-kit+ve cells differentiation is regulated by CD63/?-catenin pathway in vivo. Additionally, we provide evidence that TIMP-1 protects the heart from adverse cardiac remodeling through inhibition of cardiac apoptosis and fibrosis leading to significantly (p(<)0.05) improved contractile function. Collectively, our data show TIMP-1 plays a dual protective role in the MI heart. It activates a unique stem cell population, CD63+ve/c-kit+ve, which proliferates and differentiates into functional myocytes, smooth muscle cells and endothelial cells mediated through CD63/?-catenin pathway. TIMP-1 also protects the heart from adverse cardiac remodeling. Increased cardiac regeneration and inhibition of adverse cardiac remodeling consequently lead to restored cardiac function. ?
Title: TIMP-1 ACTIVATES A UNIQUE CARDIAC STEM CELL POPULATION, CD63+ve/C-KIT+ve, THEREBY ENHANCING CARDIAC DIFFERENTIATION, AND PROTECTS THE HEART FROM ADVERSE CARDIAC REMODELING FOLLOWING MYOCARDIAL INFARCTION.
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Name(s): Abdelli, Latifa, Author
Singla, Dinender, Committee Chair
Cheng, Zixi, Committee Member
Parthasarathy, Sampath, Committee Member
Jewett, Mollie, Committee Member
University of Central Florida, Degree Grantor
Type of Resource: text
Date Issued: 2015
Publisher: University of Central Florida
Language(s): English
Abstract/Description: We previously demonstrated that embryonic stem (ES) cells over-expressing tissue inhibitor of metalloproteinase-1 (TIMP-1) have increased potential to engraft and differentiate into cardiac myocytes following transplantation into the infarcted heart. However, the ability of TIMP-1 to activate endogenous stem cells and enhance their differentiation into cardiac regenerative cell types is still unknown. We postulate that TIMP-1 may additionally activate a stem cell population that enhances cardiac cell type differentiation in the infarcted myocardium. To prove this hypothesis, we isolated c-kit+ve cells from four weeks old C57BL/6 mice and cultured them in vitro in presence of ES conditioned media (ESCM), ES-TIMP-1-CM or TIMP-1. Our immunostaining data validate the existence of a novel CD63+ve/c-kit+ve cells. When treated with TIMP-1, these cells showed significantly (p(<)0.05) increased proliferation and differentiation into cardiac myocytes, vascular smooth muscle cells, and endothelial cells. Western blot analysis revealed significantly (p(<)0.05) increased expression of CD63, phosphorylated and total ?-catenin proteins. Furthermore, our RT-PCR data showed increased cardiac gene expression (GATA-4, Mef2C, and Nkx-2.5) when compared to ESCM and control cells. Based on the in vitro findings, we investigated the effect of intramyocardial delivery of TIMP-1 on endogenous CD63+ve/c-kit+ve cells following myocardial infarction (MI). C57BL/6 and TIMP-1 KO mice underwent coronary artery ligation followed by intramyocardial delivery of 20(&)#181;l of culture media (CC), ESCM, ES-TIMP-1-CM or TIMP-1. Subsequent immunohistochemistry analysis demonstrated the presence of a CD63+ve/c-kit+ve cell population within the peri-infarct area and confirmed intramyocardial delivery of ES-TIMP-1-CM or TIMP-1 significantly (p(<)0.05) enhanced their proliferation. Percentage of CD63+ve/c-kit+ve cells was significantly (p(<)0.05) lower in TIMP-1 KO mice compared to C57BL/6 animals. RT-PCR analysis revealed TIMP-1 KO animals expressed significantly less CD63 and TIMP-1 mRNAs compared to C57BL/6 mice. Activated CD63+ve/c-kit+ve cells were also able to differentiate into major cardiac cell types as previously shown in vitro. The differentiation potential of these cells was however higher in C57BL/6 mice compared to TIMP-1 KO mice. We also demonstrate that CD63+ve/c-kit+ve cells differentiation is regulated by CD63/?-catenin pathway in vivo. Additionally, we provide evidence that TIMP-1 protects the heart from adverse cardiac remodeling through inhibition of cardiac apoptosis and fibrosis leading to significantly (p(<)0.05) improved contractile function. Collectively, our data show TIMP-1 plays a dual protective role in the MI heart. It activates a unique stem cell population, CD63+ve/c-kit+ve, which proliferates and differentiates into functional myocytes, smooth muscle cells and endothelial cells mediated through CD63/?-catenin pathway. TIMP-1 also protects the heart from adverse cardiac remodeling. Increased cardiac regeneration and inhibition of adverse cardiac remodeling consequently lead to restored cardiac function. ?
Identifier: CFE0005750 (IID), ucf:50108 (fedora)
Note(s): 2015-08-01
Ph.D.
Medicine, Burnett School of Biomedical Sciences
Doctoral
This record was generated from author submitted information.
Subject(s): Myocardial Infarction -- Cardiac Stem Cells -- TIMP-1 -- c-kit -- CD63 -- ?-catenin -- proliferation -- differentiation.
Persistent Link to This Record: http://purl.flvc.org/ucf/fd/CFE0005750
Restrictions on Access: campus 2018-08-15
Host Institution: UCF

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