Summary： Primary cell culture, techniques of gene transfection, gelatin zymography, and Western blot were used to investigate the effect of hypoxia on the secretion of MMP 2 and MMP-9 in pulmonary artery endothelial ...Summary： Primary cell culture, techniques of gene transfection, gelatin zymography, and Western blot were used to investigate the effect of hypoxia on the secretion of MMP 2 and MMP-9 in pulmonary artery endothelial cells （PAEC） and smooth muscle cells （PASMC）, and the role of HIF-1. Our results showed that （1） after exposure to hypoxia for 24 h, the protein content and activity of MMP-2 in the PAEC medium as well as these of MMP-2 and MMP-9 in PASMC medium （P〈0. 01 ） decreased significantly in contrast to those in normoxic group （P（0.05） ; （2） after transfection of wild type EPO3＇ enhancer, a HIF-1 decoy, the content and activity of MMP 2 and MMP-9 in hypoxic mediums became higher than those in normoxic group （P〈0. 01）, while transfection of mutant EPO3＇-enhancer didn＇t affect the hypoxia-induced down-regulation. It is concluded that hypoxia could inhibit the secretion and activity of MMP 2 and MMP-9 in PAEC and PASMC, which could he mitigated by the transfection of EPO3 ＇-enhancer and that H1F-1 pathway might contribute to hypoxia-induced down regulation of MMP-2 and MMP-9.展开更多
The plasma effects during hypoxia and hemorrhagic shock on the interactions between plymorphonuclear neutrophils (PMNs) and cultured pulmonary artery endothelial cells (PAECs) were studied. The plasma samples were obt...The plasma effects during hypoxia and hemorrhagic shock on the interactions between plymorphonuclear neutrophils (PMNs) and cultured pulmonary artery endothelial cells (PAECs) were studied. The plasma samples were obtained from the goats under the following conditions: (1)Normal control plasma was obtained from the goats at sea level to aserve as the control (CP). (2)Hypoxic plasma was obtained after the goats were exposed to a simulated altitude of 4 000 m for 24 h (HP). (3) Hypotensive hypoxic plasma was obtained after the goats were bled to a mean arterial pressure of 5. 5±0. 3 kpa for 1 h under hypoxic condition (HHP). (4) Retransfused hypoxic plasma was obtained when the hypotensive goats were transfused with the shed blood for 4 h under hypoxic condition (RHP). It was found that HP , HHP and RHP especially RHP exerted profound effects on the activities of PMNs and PAECs in a concentration and time dependent manner after the PMNs and PAECs were incubated in the media containing different concentrations of the 4 kinds of plasma for different durations. Low concentration of RHP (less than 12. 5%) significantly increased the activity of PAECs (P<0. 01 vs CP) but its high concentration (more than 12. 5%) markedly decreased their activity (P<0. 01 vs CP, HP and HHP). HP, HHP and RHP increased the activity of PAECs in the early stage of incubation (1 to 3 h) (P<0. 01 vs CP) but decreased it in the late stage (6 to 12 h) (P<0. 01 vs CP). The activity of PMNs was significantly increased after 1 h incubation with HP, HHP and RHP (PM0. 001) and this effect was also concentrationdependent.The effects of RHP was the most potent, HHP the next and HP the least. The deformability of PMNs was significantly decreased (P <0. 001) after they were incubated in RHP for 3 h. The adhesive force of PMNs and PAECs was also significantly increased after 12 h incubation with RHP. These findings suggest that there are substances in the hypoxic plasma to activate or damage the interactions between PMNs and PAECs and the amounts of the substances are further increased in hypotensive hypoxic plasma and retransfused hypoxic plasma and the 'activation-damage'to PMNs and PAECs and the subsequent interactions between PMNs and PAECs play an important role in the pathological changes of hypoxia and hemorrhagic shock.展开更多
Adenosine monophosphate-activated protein kinase (AMPK) is a heterotrimeric serine-threonine kinase important as a metabolic sensor for intracellular ATP levels and plays a key role in regulating cell survival and pro...Adenosine monophosphate-activated protein kinase (AMPK) is a heterotrimeric serine-threonine kinase important as a metabolic sensor for intracellular ATP levels and plays a key role in regulating cell survival and proliferation, particularly when cells are exposed to hypoxia. AMPK is critical for lung function, and abnormal AMPK signaling participates in many lung diseases. Recent studies suggest that both inhibition and activation of AMPK are preventive for the development of pulmonary arterial hypertension (PAH). However, the molecular mechanisms by which inhibition or activation of AMPK affects pulmonary hypertension (PH) appear to be distinct. Inhibition of AMPK by compound C blocks hypoxia-induced autophagy and induces apoptosis in pulmonary artery smooth muscle cells, leading to prevention of PAH;activation of AMPK by metformin attenuates the PH phenotype induced by hypoxia by regulating endothelial cell function. These seemingly opposing data on the function of AMPK in PH can be partly explained by off-target and compartment-specific effects of AMPK inhibitors and activators and the differentiated expression of AMPK in various cell types and subcellular locations. To elucidate the specific roles of AMPK in the pathogenesis of PAH, it is important to study the role of AMPK in a tissue specific manner combining genetic and biochemical approaches.展开更多
文摘Summary： Primary cell culture, techniques of gene transfection, gelatin zymography, and Western blot were used to investigate the effect of hypoxia on the secretion of MMP 2 and MMP-9 in pulmonary artery endothelial cells （PAEC） and smooth muscle cells （PASMC）, and the role of HIF-1. Our results showed that （1） after exposure to hypoxia for 24 h, the protein content and activity of MMP-2 in the PAEC medium as well as these of MMP-2 and MMP-9 in PASMC medium （P〈0. 01 ） decreased significantly in contrast to those in normoxic group （P（0.05） ; （2） after transfection of wild type EPO3＇ enhancer, a HIF-1 decoy, the content and activity of MMP 2 and MMP-9 in hypoxic mediums became higher than those in normoxic group （P〈0. 01）, while transfection of mutant EPO3＇-enhancer didn＇t affect the hypoxia-induced down-regulation. It is concluded that hypoxia could inhibit the secretion and activity of MMP 2 and MMP-9 in PAEC and PASMC, which could he mitigated by the transfection of EPO3 ＇-enhancer and that H1F-1 pathway might contribute to hypoxia-induced down regulation of MMP-2 and MMP-9.
文摘The plasma effects during hypoxia and hemorrhagic shock on the interactions between plymorphonuclear neutrophils (PMNs) and cultured pulmonary artery endothelial cells (PAECs) were studied. The plasma samples were obtained from the goats under the following conditions: (1)Normal control plasma was obtained from the goats at sea level to aserve as the control (CP). (2)Hypoxic plasma was obtained after the goats were exposed to a simulated altitude of 4 000 m for 24 h (HP). (3) Hypotensive hypoxic plasma was obtained after the goats were bled to a mean arterial pressure of 5. 5±0. 3 kpa for 1 h under hypoxic condition (HHP). (4) Retransfused hypoxic plasma was obtained when the hypotensive goats were transfused with the shed blood for 4 h under hypoxic condition (RHP). It was found that HP , HHP and RHP especially RHP exerted profound effects on the activities of PMNs and PAECs in a concentration and time dependent manner after the PMNs and PAECs were incubated in the media containing different concentrations of the 4 kinds of plasma for different durations. Low concentration of RHP (less than 12. 5%) significantly increased the activity of PAECs (P<0. 01 vs CP) but its high concentration (more than 12. 5%) markedly decreased their activity (P<0. 01 vs CP, HP and HHP). HP, HHP and RHP increased the activity of PAECs in the early stage of incubation (1 to 3 h) (P<0. 01 vs CP) but decreased it in the late stage (6 to 12 h) (P<0. 01 vs CP). The activity of PMNs was significantly increased after 1 h incubation with HP, HHP and RHP (PM0. 001) and this effect was also concentrationdependent.The effects of RHP was the most potent, HHP the next and HP the least. The deformability of PMNs was significantly decreased (P <0. 001) after they were incubated in RHP for 3 h. The adhesive force of PMNs and PAECs was also significantly increased after 12 h incubation with RHP. These findings suggest that there are substances in the hypoxic plasma to activate or damage the interactions between PMNs and PAECs and the amounts of the substances are further increased in hypotensive hypoxic plasma and retransfused hypoxic plasma and the 'activation-damage'to PMNs and PAECs and the subsequent interactions between PMNs and PAECs play an important role in the pathological changes of hypoxia and hemorrhagic shock.
文摘Adenosine monophosphate-activated protein kinase (AMPK) is a heterotrimeric serine-threonine kinase important as a metabolic sensor for intracellular ATP levels and plays a key role in regulating cell survival and proliferation, particularly when cells are exposed to hypoxia. AMPK is critical for lung function, and abnormal AMPK signaling participates in many lung diseases. Recent studies suggest that both inhibition and activation of AMPK are preventive for the development of pulmonary arterial hypertension (PAH). However, the molecular mechanisms by which inhibition or activation of AMPK affects pulmonary hypertension (PH) appear to be distinct. Inhibition of AMPK by compound C blocks hypoxia-induced autophagy and induces apoptosis in pulmonary artery smooth muscle cells, leading to prevention of PAH;activation of AMPK by metformin attenuates the PH phenotype induced by hypoxia by regulating endothelial cell function. These seemingly opposing data on the function of AMPK in PH can be partly explained by off-target and compartment-specific effects of AMPK inhibitors and activators and the differentiated expression of AMPK in various cell types and subcellular locations. To elucidate the specific roles of AMPK in the pathogenesis of PAH, it is important to study the role of AMPK in a tissue specific manner combining genetic and biochemical approaches.
