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ABSTRACT: Smoking is the only modifiable risk factor that is associated with the development, expansion and rupture of abdominal aortic aneurysm (AAA). However, the causative link between cigarette smoke and AAA is unknown. Here we report a causative link between smoking and AAA in vivo. Acute infusion of angiotensin II (AngII) or nicotine, a major component of cigarette smoke, markedly increased the incidence of AAA in apolipoprotein E (apoE) knockout (Apoe(-/-)) mice and in mice deficient in both apoE and the AMP-activated kinase α1 subunit (AMPK-α1) (Apoe(-/-); Prkaa1(-/-) mice). In contrast, genetic deletion of AMPK-α2 (Apoe(-/-); Prkaa2(-/-) mice) ablated nicotine- or AngII-triggered AAA in vivo. Mechanistically, we found that both nicotine and AngII activated AMPK-α2 in cultured vascular smooth muscle cells (VSMCs), resulting in the phosphorylation of activator protein 2α (AP-2α) and consequent matrix metallopeptidase 2 (MMP2) gene expression. We conclude that smoking (through nicotine) instigates AAA through AMPK-α2–mediated AP-2α–dependent MMP2 expression in VSMCs.
Nature medicine 05/2012; 18(6):902-10. · 27.14 Impact Factor
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ABSTRACT: PURPOSE:: To describe a step-by-step methodology to establish a reproducible staining protocol for the evaluation of human corneal endothelial cells. METHODS:: Four procedures were performed to determine the best protocol. (1) To determine the optimal trypan blue staining method, goat corneas were stained with 4 dilutions of trypan blue (0.4%, 0.2%, 0.1%, and 0.05%) and 1% alizarin red. (2) To determine the optimal alizarin red staining method, goat corneas were stained with 2 dilutions of alizarin red (1% and 0.5%) and 0.2% trypan blue. (3) To ensure that trypan blue truly stains damaged cells, goat corneas were exposed to either 3% hydrogen peroxide or to balanced salt solution, and then stained with 0.2% trypan blue and 0.5% alizarin red. (4) Finally, fresh human corneal buttons were examined; 1 group was stained with 0.2% trypan blue and another group with 0.4% trypan blue. RESULTS:: For the 4 procedures performed, the results are as follows: (1) trypan blue staining was not observed in any of the normal corneal samples; (2) 0.5% alizarin red demonstrated sharper cell borders than 1% alizarin red; (3) positive trypan blue staining was observed in the hydrogen peroxide exposed tissue in damaged areas; (4) 0.4% trypan blue showed more distinct positive staining than 0.2% trypan blue. CONCLUSIONS:: We were able to determine the optimal vital dye staining conditions for human corneal endothelial cells using 0.4% trypan blue and 0.5% alizarin red.
Cornea 04/2012; · 1.73 Impact Factor
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ABSTRACT: The aim of the present study was to test the hypothesis that the cardiovascular-protective effects of eicosapentaenoic acid (EPA) may be due, in part, to its ability to stimulate the AMP-activated protein kinase (AMPK)-induced endothelial nitric oxide synthase (eNOS) activation. The role of AMPK in EPA-induced eNOS phosphorylation was investigated in bovine aortic endothelial cells (BAEC), in mice deficient of either AMPKα1 or AMPKα2, in eNOS knockout (KO) mice, or in Apo-E/AMPKα1 dual KO mice. EPA-treatment of BAEC increased both AMPK-Thr172 phosphorylation and AMPK activity, which was accompanied by increased eNOS phosphorylation, NO release, and upregulation of mitochondrial uncoupling protein-2 (UCP-2). Pharmacologic or genetic inhibition of AMPK abolished EPA-enhanced NO release and eNOS phosphorylation in HUVEC. This effect of EPA was absent in the aortas isolated from either eNOS KO mice or AMPKα1 KO mice fed a high-fat, high-cholesterol (HFHC) diet. EPA via upregulation of UCP-2 activates AMPKα1 resulting in increased eNOS phosphorylation and consequent improvement of endothelial function in vivo.
PLoS ONE 01/2012; 7(4):e35508. · 4.09 Impact Factor
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ABSTRACT: The aim of this study was to isolate a peptide binding to an antibody against CTGF C-terminal domain from the peptide library and to evaluate its immunological and biological activities. A phage display 12-mer peptide library was screened using anti-CTGF/C antibody as the target. Ten of the positive clones were sequenced after three rounds bio-panning. The DNA encoding peptide ZD521 was cloned and expressed as the fusion protein(TrxA-ZD521). The specificity of ZD521 to anti-CTGF/C antibody was determined by competitive inhibition assay. Mice were immunized with purified fusion protein(TrxA-ZD521) and the anti-peptide or anti-CTGF response of antiserum was also tested by enzyme-linked immunoabsorbent assay (ELISA) and Western blot. The inhibition effect of anti-serum on proliferation of kidney mesangial cells was evaluated by MTT. A peptide ZD521(GEPQTKLFSFPL) that could specifically recognize anti-CTGF/C antibody was isolated. No sequence homology was found between ZD521 and CTGF/C. The purified TrxA-ZD521 could specifically bind to anti-CTGF/C antibody and block the binding of anti-CTGF/C antibody to CTGF/C and native CTGF(mesangial cell lysate). Moreover, the antiserum from mice immunized with TrxA-ZD521 could also bind to CTGF/C recombinant protein and native CTGF, as well as significantly inhibit the proliferation of kidney mesangial cells induced by CTGF/C. Therefore, ZD521 might be a conformational epitope of CTGF which is potentially useful to be developed as a vaccine for prevention and treatment of fibrosis disorders.
International immunopharmacology 01/2009; 9(3):291-7. · 2.21 Impact Factor
