RESUMO
Heme oxygenase-1 (HO-1) has potent anti-inflammatory activity and recognized vascular protective effects. We have recently described the expression and vascular protective effects of an anti-inflammatory interleukin (IL-19), in vascular smooth muscle cells (VSMC) and injured arteries. The objective of this study was to link the anti-inflammatory effects of IL-19 with HO-1 expression in resident vascular cells. IL-19 induced HO-1 mRNA and protein in cultured human VSMC, as assayed by quantitative RT-PCR, immunoblot, and ELISA. IL-19 does not induce HO-1 mRNA or protein in human endothelial cells. IL-19 activates STAT3 in VSMC, and IL-19-induced HO-1 expression is significantly reduced by transfection of VSMC with STAT3 siRNA or mutation of the consensus STAT binding site in the HO-1 promoter. IL-19 treatment can significantly reduce ROS-induced apoptosis, as assayed by Annexin V flow cytometry. IL-19 significantly reduced ROS concentrations in cultured VSMC. The IL-19-induced reduction in ROS concentration is attenuated when HO-1 is reduced by siRNA, indicating that the IL-19-driven decrease in ROS is mediated by HO-1 expression. IL-19 reduces vascular ROS in vivo in mice treated with TNFα. This points to IL-19 as a potential therapeutic for vascular inflammatory diseases and a link for two previously unassociated protective processes: Th2 cytokine-induced anti-inflammation and ROS reduction.
Assuntos
Regulação Enzimológica da Expressão Gênica/fisiologia , Heme Oxigenase-1/biossíntese , Interleucinas/metabolismo , Músculo Liso Vascular/metabolismo , Miócitos de Músculo Liso/metabolismo , Espécies Reativas de Oxigênio/metabolismo , Animais , Apoptose/efeitos dos fármacos , Apoptose/fisiologia , Células Cultivadas , Regulação Enzimológica da Expressão Gênica/efeitos dos fármacos , Heme Oxigenase-1/genética , Heme Oxigenase-1/imunologia , Humanos , Interleucinas/genética , Interleucinas/imunologia , Camundongos , Músculo Liso Vascular/imunologia , Miócitos de Músculo Liso/imunologia , RNA Mensageiro/biossíntese , RNA Mensageiro/genética , RNA Mensageiro/imunologia , Espécies Reativas de Oxigênio/imunologia , Elementos de Resposta/fisiologia , Fator de Transcrição STAT3/genética , Fator de Transcrição STAT3/imunologia , Fator de Transcrição STAT3/metabolismo , Células Th2/imunologia , Células Th2/metabolismo , Fator de Necrose Tumoral alfa/imunologia , Fator de Necrose Tumoral alfa/metabolismo , Fator de Necrose Tumoral alfa/farmacologia , Vasculite/genética , Vasculite/imunologia , Vasculite/metabolismoRESUMO
Allograft inflammatory factor-1 (AIF-1) is a cytoplasmic, scaffold signal transduction protein constitutively expressed in inflammatory cells, but inducible in vascular smooth muscle cells (VSMCs) in response to injury or inflammatory stimuli. Although several basic science and population studies have reported increased AIF-1 expression in human and experimental atherosclerosis, a direct causal effect of AIF-1 expression on development of atherosclerosis has not been reported. The purpose of this study is to establish a direct relationship between AIF-1 expression and development of atherosclerosis. AIF-1 expression is detected VSMC in atherosclerotic lesions from ApoE(-/-) mice, but not normal arteries from wild-type mice. AIF-1 expression can be induced in cultured VSMC by stimulation with oxidized LDL (ox-LDL). Transgenic mice in which AIF-1 expression is driven by the G/C modified SM22 alpha promoter to restrict AIF-1 expression to VSMC develop significantly increased atherosclerosis compared with wild-type control mice when fed a high-fat diet (P=0.022). Cultured VSMC isolated from Tg mice demonstrated significantly increased migration in response to ox-LDL compared with matched controls (P<0.001). VSMC isolated from Tg mice and cultured human VSMC which over express AIF-1 demonstrated increased expression of MMP-2 and MMP-9 mRNA and protein and increased NF-κB activation in response to ox-LDL as compared with wild-type control mice. VSMC which over express AIF-1 have significantly increased uptake of ox-LDL, and increased CD36 expression. Together, these data suggest a strong association between AIF-1 expression, NF-κB activation, and development of experimental atherosclerosis.
Assuntos
Doenças da Aorta/metabolismo , Aterosclerose/metabolismo , Proteínas de Ligação ao Cálcio/metabolismo , Dieta Hiperlipídica , Proteínas dos Microfilamentos/metabolismo , Músculo Liso Vascular/metabolismo , Miócitos de Músculo Liso/metabolismo , Animais , Aorta Abdominal/metabolismo , Aorta Abdominal/patologia , Doenças da Aorta/etiologia , Doenças da Aorta/genética , Doenças da Aorta/patologia , Apolipoproteínas E/deficiência , Apolipoproteínas E/genética , Aterosclerose/etiologia , Aterosclerose/genética , Aterosclerose/patologia , Antígenos CD36/metabolismo , Proteínas de Ligação ao Cálcio/genética , Movimento Celular , Células Cultivadas , Modelos Animais de Doenças , Humanos , Lipoproteínas LDL/metabolismo , Metaloproteinase 2 da Matriz/genética , Metaloproteinase 9 da Matriz/genética , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Knockout , Camundongos Transgênicos , Proteínas dos Microfilamentos/genética , Proteínas Musculares/genética , Músculo Liso Vascular/patologia , Miócitos de Músculo Liso/patologia , NF-kappa B/metabolismo , Regiões Promotoras Genéticas , RNA Mensageiro/metabolismo , Fatores de Tempo , TransfecçãoRESUMO
Wavelength-resolved femtosecond transient absorption spectroscopy is used to follow the electronic dynamics of single-walled carbon nanotubes in polymers following visible photoexcitation. Electron-hole (e-h) pairs give rise to sharp features in the transient spectra that decay in amplitude and exhibit rapid spectral shifts. The decay reflects (e-h) recombination on both short (1.3 ps) and long (35 ps) time scales. Transient spectra also exhibit a broad photobleach at early times that arises from the cooling of a hot electron gas created via excitation at the red edge of a pi-plasmon band.