Abstract Objective To evaluate the possible vascular effects of an environment carcinogen benzo（a）pyrene （BaP）. Methods The cytotoxicit of BaP and rat liver S9 （0.25 mg/mL）-activated BaP were examined by MTT ass...Abstract Objective To evaluate the possible vascular effects of an environment carcinogen benzo（a）pyrene （BaP）. Methods The cytotoxicit of BaP and rat liver S9 （0.25 mg/mL）-activated BaP were examined by MTT assay. Thoracic aortic rings were dissected from Sprague-Dawley rats. Contraction of aortic rings was induced by 60 mmol/L KCl or 10-6 mol/L phenylephrine （PE） in an ex-vivo perfusion system after BaP （100 tlmol/L） incubation for 6 h. [Ca^2＋]i was measured using Fluo-4/AM. For in-vivo treatment, rats were injected with BaP for 4 weeks （10 mg/kg, weekly, i.p.）. Results BaP （1-500 μm） did not significantly affect cell viability; S9-activated BaP stimulated cell proliferation. BaP did not affect the contractile function of endothelium-intact or -denuded aortic rings. BaP did not affect ATP-induced （[Ca2＋]i） increases in human umbilical vein endothelial cells. In BaP-treated rats, heart rate and the number of circulating inflammatory cells were not affected. Body weight decreased while blood pressure increased significantly. The maximum aortic contractile responses to PE and KCI and the maximum aortic relaxation response to acetylcholine were significantly decreased by 25.0%, 34.2%, and 10.4%, respectively. Conclusion These results suggest, in accordance with its DNA-damaging properties, that metabolic activation is a prerequisite for BaP-induced cardiovascular toxicity.展开更多
AIM To investigate the effect of metformin on activated hepatic stellate cells(HSCs) and the possible signaling pathways involved. METHODS A fibrotic mouse model was generated by intraperitoneal injection of carbon te...AIM To investigate the effect of metformin on activated hepatic stellate cells(HSCs) and the possible signaling pathways involved. METHODS A fibrotic mouse model was generated by intraperitoneal injection of carbon tetrachloride(CCl_4) and subsequent treatment with or without metformin. The level of fibrosis was detected by hematoxylin-eosin staining, Sirius Red staining, and immunohistochemistry. The HSC cell line LX-2 was used for in vitro studies. The effect of metformin on cell proliferation(CCK8 assay),motility(scratch test and Transwell assay), contraction(collagen gel contraction assay), extracellular matrix(ECM) secretion(Western blot), and angiogenesis(ELISA and tube formation assay) was investigated. We also analyzed the possible signaling pathways involved by Western blot analysis.RESULTS Mice developed marked liver fibrosis after intraperitoneal injection with CCl_4 for 6 wk. Metformin decreased the activation of HSCs, reduced the deposition of ECM, and inhibited angiogenesis in CCl_4-treated mice. Platelet-derived growth factor(PDGF) promoted the fibrogenic response of HSCs in vitro, while metformin inhibited the activation, proliferation, migration, and contraction of HSCs, and reduced the secretion of ECM. Metformin decreased the expression of vascular endothelial growth factor(VEGF) in HSCs through inhibition of hypoxia inducible factor(HIF)-1α in both PDGF-BB treatment and hypoxic conditions, and it down-regulated VEGF secretion by HSCs and inhibited HSC-based angiogenesis in hypoxic conditions in vitro. The inhibitory effects of metformin on activated HSCs were mediated by inhibiting the Akt/mammalian target of rapamycin(m TOR) and extracellular signal-regulated kinase(ERK) pathways via the activation of adenosine monophosphate-activated protein kinase(AMPK).CONCLUSION Metformin attenuates the fibrogenic response of HSCs in vivo and in vitro, and may therefore be useful for the treatment of chronic liver diseases.展开更多
Pulmonary artery hypertension is a serious disease in respiratory system and a key tache in the mechanism of pulmonary-heart disease. The pathological changes include the contraction and remodeling of the pulmonary ve...Pulmonary artery hypertension is a serious disease in respiratory system and a key tache in the mechanism of pulmonary-heart disease. The pathological changes include the contraction and remodeling of the pulmonary vessels. There are more and more studies on the pulmonary artery hypertension because of its refractory character and the following increasing mortality. This article summarizes the updating research of the factors and mechanism studied on pulmonary artery hypertension recently,to provide a new view for the clinical and basic medical investigation.展开更多
基金supported by National Natural Science Foundation of China,grant numbers30872140and81172692Zhejiang Provincial Natural Science Foundation,R2100555Ministry of Science and Technology,China,2009DFB30390
文摘Abstract Objective To evaluate the possible vascular effects of an environment carcinogen benzo（a）pyrene （BaP）. Methods The cytotoxicit of BaP and rat liver S9 （0.25 mg/mL）-activated BaP were examined by MTT assay. Thoracic aortic rings were dissected from Sprague-Dawley rats. Contraction of aortic rings was induced by 60 mmol/L KCl or 10-6 mol/L phenylephrine （PE） in an ex-vivo perfusion system after BaP （100 tlmol/L） incubation for 6 h. [Ca^2＋]i was measured using Fluo-4/AM. For in-vivo treatment, rats were injected with BaP for 4 weeks （10 mg/kg, weekly, i.p.）. Results BaP （1-500 μm） did not significantly affect cell viability; S9-activated BaP stimulated cell proliferation. BaP did not affect the contractile function of endothelium-intact or -denuded aortic rings. BaP did not affect ATP-induced （[Ca2＋]i） increases in human umbilical vein endothelial cells. In BaP-treated rats, heart rate and the number of circulating inflammatory cells were not affected. Body weight decreased while blood pressure increased significantly. The maximum aortic contractile responses to PE and KCI and the maximum aortic relaxation response to acetylcholine were significantly decreased by 25.0%, 34.2%, and 10.4%, respectively. Conclusion These results suggest, in accordance with its DNA-damaging properties, that metabolic activation is a prerequisite for BaP-induced cardiovascular toxicity.
基金Supported by National Natural Science Foundation of China,No.81370590
文摘AIM To investigate the effect of metformin on activated hepatic stellate cells(HSCs) and the possible signaling pathways involved. METHODS A fibrotic mouse model was generated by intraperitoneal injection of carbon tetrachloride(CCl_4) and subsequent treatment with or without metformin. The level of fibrosis was detected by hematoxylin-eosin staining, Sirius Red staining, and immunohistochemistry. The HSC cell line LX-2 was used for in vitro studies. The effect of metformin on cell proliferation(CCK8 assay),motility(scratch test and Transwell assay), contraction(collagen gel contraction assay), extracellular matrix(ECM) secretion(Western blot), and angiogenesis(ELISA and tube formation assay) was investigated. We also analyzed the possible signaling pathways involved by Western blot analysis.RESULTS Mice developed marked liver fibrosis after intraperitoneal injection with CCl_4 for 6 wk. Metformin decreased the activation of HSCs, reduced the deposition of ECM, and inhibited angiogenesis in CCl_4-treated mice. Platelet-derived growth factor(PDGF) promoted the fibrogenic response of HSCs in vitro, while metformin inhibited the activation, proliferation, migration, and contraction of HSCs, and reduced the secretion of ECM. Metformin decreased the expression of vascular endothelial growth factor(VEGF) in HSCs through inhibition of hypoxia inducible factor(HIF)-1α in both PDGF-BB treatment and hypoxic conditions, and it down-regulated VEGF secretion by HSCs and inhibited HSC-based angiogenesis in hypoxic conditions in vitro. The inhibitory effects of metformin on activated HSCs were mediated by inhibiting the Akt/mammalian target of rapamycin(m TOR) and extracellular signal-regulated kinase(ERK) pathways via the activation of adenosine monophosphate-activated protein kinase(AMPK).CONCLUSION Metformin attenuates the fibrogenic response of HSCs in vivo and in vitro, and may therefore be useful for the treatment of chronic liver diseases.
文摘Pulmonary artery hypertension is a serious disease in respiratory system and a key tache in the mechanism of pulmonary-heart disease. The pathological changes include the contraction and remodeling of the pulmonary vessels. There are more and more studies on the pulmonary artery hypertension because of its refractory character and the following increasing mortality. This article summarizes the updating research of the factors and mechanism studied on pulmonary artery hypertension recently,to provide a new view for the clinical and basic medical investigation.
