Am J Physiol Heart Circ Physiol 304: H786-H795, 2013 First publi

Am J Physiol Heart Circ Physiol 304: H786-H795, 2013. First published January 4, 2013; doi:10.1152/ajpheart.00697.2012.-This study aims to identify the potential mechanisms by which perivascular adipose tissue (PVAT) reduces tone in small arteries. Small mesenteric arteries from wild-type and large-conductance Ca2+-activated K+ (BKCa) channel knockout mice were mounted on a wire myograph in the presence and absence of PVAT, and contractile responses to norepinephrine were assessed. Electrophysiology studies were performed in isolated vessels to measure changes in membrane buy Ruboxistaurin potential produced by adiponectin. Contractile responses from wild-type mouse small arteries were significantly reduced in the

presence of PVAT. This was not observed in the presence of a BKCa channel inhibitor or with nitric oxide synthase (NOS) inhibition or in BKCa or adiponectin knockout mice. Solution transfer experiments demonstrated the presence of an anticontractile factor released from PVAT. Adiponectin-induced vasorelaxation and hyperpolarization in wild-type arteries were not evident in the absence of or after inhibition of BKCa channels. PVAT from BKCa or adiponectin

knockout mice failed Belinostat mw to elicit an anticontractile response in wild-type arteries. PVAT releases adiponectin, which is an anticontractile factor. Its effect on vascular tone is mediated by activation of BKCa channels on vascular smooth muscle cells and adipocytes and by endothelial mechanisms.”
“Despite the prominent pro-apoptotic role of p53, this protein has also been shown to promote cell survival in response to metabolic stress. However, the specific mechanism by which p53 protects cells

from metabolic stress-induced death is unknown. Earlier we reported that carnitine palmitoyltransferase 1C (CPT1C), a brain-specific member of a family of mitochondria-associated enzymes that have a central role in fatty acid metabolism promotes cell survival and tumor growth. Unlike other members of the CPT family, the subcellular localization of CPT1C and its cellular function remains elusive. Here, we report that CPT1C is a novel p53-target gene with a bona fide p53-responsive element within Selleck SCH727965 the first intron. CPT1C is upregulated in vitro and in vivo in a p53-dependent manner. Interestingly, expression of CPT1C is induced by metabolic stress factors such as hypoxia and glucose deprivation in a p53 and AMP activated kinase-dependent manner. Furthermore, in a murine tumor model, depletion of Cpt1c leads to delayed tumor development and a striking increase in survival. Taken together, our results indicate that p53 protects cells from metabolic stress via induction of CPT1C and that CPT1C may have a crucial role in carcinogenesis. CPT1C may therefore represent an exciting new therapeutic target for the treatment of hypoxic and otherwise treatment-resistant tumors. Cell Death and Differentiation (2013) 20, 659-668; doi:10.1038/cdd.2012.

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