Regulation of mouse blastocyst adhesion, outgrowth and matrix metalloproteinase-2 by focal adhesion kinase

2003 ◽  
Vol 48 (5) ◽  
pp. 475-479
Author(s):  
Guodong Tie ◽  
Yongqiang Tian ◽  
Shuyi Chen ◽  
Yujing Cao ◽  
Zelong Liu ◽  
...  
Keyword(s):  
Matrix Metalloproteinase ◽  
Focal Adhesion Kinase ◽  
Focal Adhesion ◽  
Matrix Metalloproteinase 2 ◽  
Mouse Blastocyst

Matrix metalloproteinase-2 stimulates collagen-I expression through phosphorylation of focal adhesion kinase in rat cardiac fibroblasts

2012 ◽  
Vol 303 (9) ◽  
pp. C947-C953 ◽  
Author(s):  
Yasutomo Hori ◽  
Takashige Kashimoto ◽  
Tomohiro Yonezawa ◽  
Naoya Sano ◽  
Ryuta Saitoh ◽  
...  
Keyword(s):  
Extracellular Matrix ◽  
Matrix Metalloproteinase ◽  
Focal Adhesion Kinase ◽  
Focal Adhesion ◽  
Cardiac Fibroblasts ◽  
Primary Cultures ◽  
Collagen I ◽  
Matrix Metalloproteinase 2 ◽  
Dependent Manner ◽  
Simultaneous Treatment

Collagen-I is thought to be the main component of the extracellular matrix in cardiac fibrosis, the accumulation of which occurs with excessive activation of matrix metalloproteinase-2 (MMP-2). MMP-2 degrades the extracellular matrix; however, the relative importance of MMP-2 to collagen-I synthesis in cardiac fibroblasts remains unclear. We investigated whether extracellular activation of MMP-2 regulates collagen-I synthesis and phosphorylation of focal adhesion kinase (FAK) in rat cardiac fibroblasts. Primary cultures of rat cardiac fibroblasts were incubated with purified active MMP-2 to determine whether extracellular MMP-2 affects collagen-I synthesis and FAK phosphorylation in cardiac fibroblasts. Exogenous MMP-2 significantly stimulated FAK (Tyr397) phosphorylation and induced collagen-I expression in a time-dependent manner. Simultaneous treatment with the FAK inhibitor PF573228 abolished exogenous MMP-2-enhanced FAK (Tyr397) phosphorylation and collagen-I expression. Cells were then stimulated with norepinephrine (NE) to investigate whether endogenous MMP-2 could also induce collagen-I expression through FAK (Tyr397) phosphorylation. NE-stimulated endogenous MMP-2 activation in conditioned medium was significantly attenuated by simultaneous treatment with the MMP inhibitor PD166793. Similarly, NE-induced FAK (Tyr397) phosphorylation and collagen-I expression were significantly inhibited by simultaneous treatment with PD166793 or PF573228. Furthermore, MMP-2 knockdown induced by small interfering RNA (siRNA) significantly abolished endogenous MMP-2 expression and activation. MMP-2 siRNA significantly abolished NE-induced FAK (Tyr397) phosphorylation and collagen-I expression. These findings suggest that the extracellular activation of MMP-2 accelerated collagen-I synthesis in rat cardiac fibroblasts and that FAK phosphorylation (Tyr397) plays a pivotal role in MMP-2-stimulated collagen-I synthesis.

Abstract P154: Focal Adhesion Kinase Plays a Critical Role in Upregulating Fibrogenesis in Load-Induced Cardiac Hypertrophy

2011 ◽  
Vol 109 (suppl_1) ◽  
Author(s):  
Ana Paula Dalla Costa ◽  
Carolina F Clemente ◽  
Thais H Theizen ◽  
José Roberto Souza ◽  
Leandro Cardoso ◽  
...  
Keyword(s):  
Cardiac Hypertrophy ◽  
Focal Adhesion Kinase ◽  
Myocardial Fibrosis ◽  
Focal Adhesion ◽  
Cardiac Fibroblasts ◽  
Heart Diseases ◽  
Smooth Muscle Actin ◽  
Critical Role ◽  
Matrix Metalloproteinase 2 ◽  
Activated Fibroblasts

Myocardial fibrosis is maladaptive, accelerating the evolution of diseased hearts to failure. The pathogenesis of myocardial fibrosis is critically dependent on complex processes of activation (i.e. enhanced proliferation, production and secretion of soluble factors, collagen and matrix metalloproteinases) and terminal differentiation of cardiac fibroblasts into myofibroblasts, resultant from the mobilization of numerous signaling molecules by physical and humoral stimuli. Noting that Focal Adhesion Kinase (FAK) is activated in areas of ongoing myocardial fibrosis, we sought to examine whether it is a critical mediator of fibrogenesis in load-induced hypertrophic hearts. Isolated fibroblasts from hypertrophic hearts of mice subjected to transverse aortic constriction (TAC; 1 to 8 weeks) were highly activated as recognized by markers that indicate enhanced proliferation (nuclear Ki67), production of collagen and matrix metalloproteinase-2 (MMP-2) and differentiation into myofibroblasts (expression of α-smooth muscle actin - α-SMA). In these cells, FAK was upregulated, as also were its dowstream pathways Src/ERK1/2 and PI3K/AKT/mTOR. Depletion of FAK (∼80%) after treatment with small interfering RNA (siRNA-FAK) markedly attenuated cardiac hypertrophy and fibrosis, and significantly reduced the number of activated fibroblasts harvested from overloaded hearts. Restoration of FAK function by overexpressing a full-length FAK construct in these cells, selectively enhanced the activity of the downstream PI3K/AKT/mTOR and rescued the activated phenotype of fibroblasts. Transfection with an inactive FAK mutant (Tyr397 substituted by phenylalanine) did not rescue the activated phenotype of fibroblasts harvested from overloaded hearts depleted of FAK. However, cells harvested from overloaded hearts depleted of FAK and treated with the mTOR activating aminoacid leucine showed typical phenotype of activated fibroblasts. These findings uncover a role for FAK in regulating the signaling cascade PI3K/AKT/mTOR in cardiac fibroblasts, which seems to be critical for the pathogenesis of myocardial fibrosis in hypertrophic hearts. Targeting this pathway may provide a novel strategy for treating hypertrophic heart diseases.

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