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Aim To study the effect of menthol on hypobaric hypoxia-induced pulmonary arterial hypertension and explore the underlying mechanism in mice. Methods 10 to 12 weeks old wild type (WT) mice and TRPM8 gene knockout (TRPM8
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Intrauterine growth retardation (IUGR) is associated with the development of adult-onset diseases, including pulmonary hypertension. However, the underlying mechanism of the early nutritional insult that results in pulmonary vascular dysfunction later in life is not fully understood. Here, we investigated the role of tyrosine phosphorylation of voltage-gated potassium channel 1.5 (Kv1.5) in this prenatal event that results in exaggerated adult vascular dysfunction. A rat model of chronic hypoxia (2 weeks of hypoxia at 12 weeks old) following IUGR was used to investigate the physiological and structural effect of intrauterine malnutrition on the pulmonary artery by evaluating pulmonary artery systolic pressure and vascular diameter in male rats. Kv1.5 expression and tyrosine phosphorylation in pulmonary artery smooth muscle cells (PASMCs) were determined. We found that IUGR increased mean pulmonary artery pressure and resulted in thicker pulmonary artery smooth muscle layer in 14-week-old rats after 2 weeks of hypoxia, while no difference was observed in normoxia groups. In the PASMCs of IUGR-hypoxia rats, Kv1.5 mRNA and protein expression decreased while that of tyrosine-phosphorylated Kv1.5 significantly increased. These results demonstrate that IUGR leads to exaggerated chronic hypoxia pulmonary arterial hypertension (CH-PAH) in association with decreased Kv1.5 expression in PASMCs. This phenomenon may be mediated by increased tyrosine phosphorylation of Kv1.5 in PASMCs and it provides new insight into the prevention and treatment of IUGR-related CH-PAH.
Subject(s)
Animals , Male , Female , Pregnancy , Organophosphates/metabolism , Polymers/metabolism , Kv1.5 Potassium Channel/analysis , Fetal Hypoxia/complications , Fetal Hypoxia/physiopathology , Fetal Growth Retardation/metabolism , Hypertension, Pulmonary/etiology , Muscle, Smooth, Vascular/chemistry , Phosphorylation , Prenatal Exposure Delayed Effects/metabolism , Pulmonary Artery/physiopathology , Pulmonary Artery/pathology , Time Factors , RNA, Messenger/analysis , Immunohistochemistry , Immunoblotting , Random Allocation , Up-Regulation , Fluorescent Antibody Technique , Rats, Sprague-Dawley , Malnutrition/complications , Disease Models, Animal , Fetal Growth Retardation/etiology , Real-Time Polymerase Chain Reaction , Hypertension, Pulmonary/physiopathology , Hypertension, Pulmonary/pathology , Muscle, Smooth, Vascular/pathologyABSTRACT
Objective To study the function of the toll-like receptor-4 (TLR-4) signaling pathway in the synthesis and secretion of pulmonary artery smooth muscle cells of rats with COPD. Methods The primary pulmonary artery smooth muscle cells (PASMCs) of rats with COPD were digested, separated and purified. Then they were randomly divided into control group, LPS group, TLR4 inhibitor group (TAK242) and LPS + TLR4 inhibitor group. RT-PCR, Western blot were used to detect the expression level of TLR-4 and NF-κB among groups. The levels of IFN-γ and PDGF-AB in supernatant with PASMCs in each group were detected by ELISA. Results LPS increased the expression of TLR-4、 NF-κB and the levels of IFN-γ and PDGF-AB. The expression of TLR4, NF-κB and the levels of IFN-γ and PDGF-AB were significantly reduced after inhibiting the expression of TLR4(P < 0.05). Conclusion TLR-4 signaling pathway involved in the inflammatory response and pulmonary vascular remodeling which increased the synthesis and secretion of IFN-γ and PDGF-AB in PASMCs. It provides a theoretical approach for the early intervention of clinical with COPD.
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Pulmonary artery hypertension (PAH ) is a chronic progressive disease characterized by a persistent elevation of pul-monary vascular pressure,and the disease would limit the right ventricular function severely,fail the organ and even lead to death in the end.The histopathological change of PAH is fea-tured by the restructuring of pulmonary vessels,and the abnor-mal reproduction of pulmonary artery smooth muscle cells (PASMCs)in peripheral vessels is the major pathological basis of pulmonary vascular restructuring.This paper mainly reviews the research advances on signal transduction mechanisms and their inhibitors in promoting the proliferation of pulmonary artery smooth muscle cells.
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This study is to explore the activation of the Ca2+/CaM/CaN signal pathway in 5-HT-induced proliferation of rat pulmonary artery smooth muscle cells (PASMCs) and the inhibitory effect of m-nisoldipine (m-Nis) on this pathway. PASMCs were cultured with the explant technique. The proliferation of PASMCs was evaluated by MTT assay. Confocal microscopy was used to measure the change of [Ca2+]i. The mRNA expression of CaM and CaN was evaluated by RT-PCR and the activity of CaN was measured according to the instruction of kits. The results of MTT assay suggested that 5-HT (1 ?mol?L-1) significantly induced the proliferation of rat PASMCs (P
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Aim To explore the effect of m-Nisoldipine(m-Nis) on 5-HT-induced proliferation,migration of rat PASMCs and to study the mechanisms.Methods PASMCs were cultured with the explant technique,and were divided into 6 groups:control group,5-HT(1 μmol·L~(-1)) group and m-Nis(10~(-5),10~(-6),10~(-7),10~(-8) mol·L~(-1))group.MTT assay was used to evaluate the proliferation of PASMCs,and transwell chambers were used to detect the migration of PASMCs.In addition,the expression of PCNA and the phosphorylation of ERK1/2 were evaluated by Western blot analysis.Results m-Nis inhibited the proliferation(P<0.05 or P<0.01)and migration(P<0.01)of rat PASMCs induced by 5-HT obviously.Similarly,Western blot analysis of PCNA indicated that the expression of PCNA was significantly higher in 5-HT group than that in control group(P<0.01).Whereas,in four m-Nis treated groups,the level of PCNA was markedly decreased(P<0.05 or P<0.01).Meanwhile,m-Nis 10~(-5),10~(-6) and 10~(-7) mol·L~(-1) pretreatment also reduced 5-HT-induced phosphorylation of ERK1/2 obviously(P<0.05 or P<0.01).Conclusion m-Nis inhibits 5-HT-induced proliferation and migration of rat PASMCs obviously,which may be related to the inhibition of PCNA expression and the blockage of ERK1/2/MAPK signal pathway.
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Aim: The purpose of this study was to observe the effect of 15-HETE on rabbit pulmonary artery (PA) vasoconstriction after removing extracellular Ca2+ and on [Ca2+]i in PASMCs and to discuss the mechanisms of cytosolic Ca2+ mobilization induced by 15-HETE. Methods: We used tention studies of PA rings to observe the effect of L-type Ca2+ channel blocker and non-Ca2+ solution on PA vasoconstriction induced by 15-HETE. Then we used laser-scanning confocal microscope to investigate [Ca2+]i signaling in cultured PASMCs. Results: L-type Ca2+ channel blocker and non-Ca2+ solution had no effect on 15-HETE induced vasoconstriction in normoxic and hypoxic rabbit PA rings. The increase of [Ca2+]i was shown in 15-HETE group cells and the change in [Ca2+]i induced by 15-HETE was significantly different from that of control. Conclusion: 15-HETE may activate Ca2+ release from intracellular stores and raise [Ca2+]i in PASMCs.
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Aim To test the contribution of 15-HETE on expression of KV1.5 channel under hypoxia condition,using CDC or NDGA to block 15-LO/15-HETE,and to observe the effect of hypoxia on KV1.5 channel protein,mRNA expressions in cultured rat pulmonary arterial smooth muscle cells(PASMCs)and pulmonary arterials(PAs).Methods Western blot,RT-PCR and 15-LO blockers,cinnamyl 3,4-dihydroxy-[alpha]-cyanocinnamate(CDC)or nordihydroguiairetic acid(NDGA)were used to identify the role of endogenous 15-HETE on expression of KV1.5 channel in cultured rat pulmonary arterial smooth muscle cells(PASMCs)and PAs.Results(1)The expressions of KV1.5 channel protein and mRNA in PASMCs and PAs preteated with CDC or NDGA greatly increased than those of PASMCs under hypoxia group.(2)Exogenous 15-HETE added to PASMCs pretreated with CDC or NDGA greatly decreased the expression of KV1.5 than that of adding PASMCs pretreated with CDC or NDGA under hypoxia condition.Conclusion The down-regulation of KV1.5 channel expression caused by hypoxia is through endogenous 15-HETE.