Tumor necrosis factor receptor-associated factor 2 signaling provokes adverse cardiac remodeling in the adult mammalian heart

Vijay G. Divakaran, Sarah Evans, Veli K. Topkara, Abhinav Diwan, Jana Burchfield, Feng Gao, Jianwen Dong, Huei-Ping Tzeng, Natarajan Sivasubramanian, Philip M. Barger, and Douglas L. Mann; Circulation: Heart Failure Read More


Background—Tumor necrosis factor superfamily ligands provoke a dilated cardiac phenotype signal through a common scaffolding protein termed tumor necrosis factor receptor–associated factor 2 (TRAF2); however, virtually nothing is known about TRAF2 signaling in the adult mammalian heart.

Methods and Results—We generated multiple founder lines of mice with cardiac-restricted overexpression of TRAF2 and characterized the phenotype of mice with higher expression levels of TRAF2 (myosin heavy chain [MHC]-TRAF2HC). MHC-TRAF2HC transgenic mice developed a time-dependent increase in cardiac hypertrophy, left ventricular dilation, and adverse left ventricular remodeling, and a significant decrease in LV+dP/dt and LV−dP/dt when compared with littermate controls (P<0.05 compared with littermate). During the early phases of left ventricular remodeling, there was a significant increase in total matrix metalloproteinase activity that corresponded with a decrease in total myocardial fibrillar collagen content. As the MHC-TRAF2HC mice aged, there was a significant decrease in total matrix metalloproteinase activity accompanied by an increase in total fibrillar collagen content and an increase in myocardial tissue inhibitor of metalloproteinase-1 levels. There was a significant increase in nuclear factor–κB activation at 4 to 12 weeks and jun N-terminal kinases activation at 4 weeks in the MHC-TRAF2HC mice. Transciptional profiling revealed that >95% of the hypertrophic/dilated cardiomyopathy–related genes that were significantly upregulated genes in the MHC-TRAF2HC hearts contained κB elements in their promoters.

Conclusions—These results show for the first time that targeted overexpression of TRAF2 is sufficient to mediate adverse cardiac remodeling in the heart.

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Posted on May 13, 2014
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