Research progress on the mechanism of phenotypic transformation of pulmonary artery smooth muscle cells induced by hypoxia / 浙江大学学报·医学版

Phenotypic transformation of pulmonary artery smooth muscle cells (PASMCs) is a key factor in pulmonary vascular remodeling. Inhibiting or reversing phenotypic transformation can inhibit pulmonary vascular remodeling and control the progression of hypoxic pulmonary hypertension. Recent studies have shown that hypoxia causes intracellular peroxide metabolism to induce oxidative stress, induces multi-pathway signal transduction, including those related to autophagy, endoplasmic reticulum stress and mitochondrial dysfunction, and also induces non-coding RNA regulation of cell marker protein expression, resulting in PASMCs phenotypic transformation. This article reviews recent research progress on mechanisms of hypoxia-induced phenotypic transformation of PASMCs, which may be helpful for finding targets to inhibit phenotypic transformation and to improve pulmonary vascular remodeling diseases such as hypoxia-induced pulmonary hypertension.

Alleviating experimental pulmonary hypertension via co-delivering FoxO1 stimulus and apoptosis activator to hyperproliferating pulmonary arteries

Pulmonary hypertension (PH) is an insidious pulmonary vasculopathy with high mortality and morbidity and its underlying pathogenesis is still poorly delineated. The hyperproliferation and apoptosis resistance of pulmonary artery smooth muscle cells (PASMCs) contributes to pulmonary vascular remodeling in pulmonary hypertension, which is closely linked to the downregulation of fork-head box transcriptional factor O1 (FoxO1) and apoptotic protein caspase 3 (Cas-3). Here, PA-targeted co-delivery of a FoxO1 stimulus (paclitaxel, PTX) and Cas-3 was exploited to alleviate monocrotaline-induced pulmonary hypertension. The co-delivery system is prepared by loading the active protein on paclitaxel-crystal nanoparticles, followed by a glucuronic acid coating to target the glucose transporter-1 on the PASMCs. The co-loaded system (170 nm) circulates in the blood over time, accumulates in the lung, effectively targets the PAs, and profoundly regresses the remodeling of pulmonary arteries and improves hemodynamics, leading to a decrease in pulmonary arterial pressure and Fulton's index. Our mechanistic studies suggest that the targeted co-delivery system alleviates experimental pulmonary hypertension primarily via the regression of PASMC proliferation by inhibiting cell cycle progression and promoting apoptosis. Taken together, this targeted co-delivery approach offers a promising avenue to target PAs and cure the intractable vasculopathy in pulmonary hypertension.

Salidroside inhibits phenotypic transformation of rat pulmonary artery smooth muscle cells induced by hypoxia / 中国中药杂志

This study investigated the effect of salidroside on phenotypic transformation of rat pulmonary artery smooth muscle cells(PASMCs) induced by hypoxia. Rat pulmonary arteries were isolated by tissue digestion and PASMCs were cultured. The OD values of cells treated with salidroside at different concentrations for 48 hours were measured by cell counting kit-8(CCK-8) to determine the appropriate concentration range of salidroside. The cells were divided into a normal(normoxia) group, a model(hypoxia) group, and three hypoxia + salidroside groups(40, 60, and 80 μg·mL~(-1)). Quantitative real-time PCR(qRT-PCR) was used to detect the mRNA expression of cell contractile markers in each group, such as α-smooth muscle actin(α-SMA), smooth muscle 22(SM22), and calcium-binding protein(calponin), and synthetic marker vimentin. The expression levels of cell phenotypic markers and proliferating cell nuclear antigen(PCNA) were detected by Western blot. The proliferation of cells in each group was detected by the 5-ethynyl-2'-deoxyuridine(EdU) assay. Cell migration was measured by Transwell assay. As revealed by results, compared with the normal group, the model group showed decreased mRNA and protein expression of contractile phenotypic markers of PASMCs and increased mRNA and protein expression of synthetic markers. Compared with the conditions in the model group, salidroside could down-regulate the mRNA and protein expression of synthetic markers in PASMCs and up-regulated the mRNA and protein expression of contractile phenotypic markers. Compared with the normal group, the model group showed potentiated proliferation and migration. Compared with the model group, the hypoxia + salidroside groups showed blunted proliferation and migration of cells after phenotypic transformation. The results suggest that salidroside can inhibit the expression of synthetic markers in PASMCs and promote the expression of contractile markers to inhibit the hypoxia-induced phenotypic transformation of PASMCs. The mechanism of salidroside in inhibiting the proliferation and migration of PASMCs is related to the inhibition of the phenotypic transformation of PASMCs.

let-7b-5p suppresses the proliferation and migration of pulmonary artery smooth muscle cells via down-regulating IGF1

Abstract Objectives Some previous studies indicated that the excessive proliferation and migration of Pulmonary Artery Smooth Muscle Cells (PASMCs) could be observed in pulmonary artery intima after Pulmonary Embolism (PE) occurred. In addition, recent studies identified some miRNAs that are differentially expressed in the blood of PE patients, which might be used as a diagnostic biomarker for PE, including let-7a-5p, let-7b-5p, and miR-150-5p. Hence, the authors sought to explore the effects of let-7b-5p in PASMC proliferation and migration and the corresponding regulatory mechanism. Methods Platelet-Derived Growth Factor (PDGF) was utilized to induce the hyper-proliferation model in PASMCs. The mRNA and protein expression levels were detected by RT-qPCR and western blot, respectively. The proliferation of PASMCs was evaluated by the detection of PCNA expression, as well as CCK-8 and Edu assays. Wound healing and Transwell assays were exploited to assess the migration ability of PASMCs. The targets of let-7b-5p were predicted based on two bioinformatics online tools. Dual-luciferase and Ago2 pull-down assays were applied to confirm the interaction between let-7b-5p and IGF1. Results 40 ng/mL PDGF was selected as the optimal concentration to induce PASMCs. let-7b-5p mimics suppressed the proliferation and migration of PDGF-induced PASMCs, while let-7b-5p inhibitor led to the opposite result. In further mechanism exploration, IGF1 was predicted and confirmed as the direct target gene of let-7b-5p. The promotion role of IGF1 overexpression on the proliferation and migration of PDGF-induced PASMCs was dramatically countered by let-7b-5p mimics. Conclusion let-7b-5p prohibits the proliferation and migration of PDGF-induced PASMCs by modulating IGF1.

Effects of Puerarin on Hypoxia Induced Pyroptosis of Pulmonary Artery Smooth Muscle Cells Based on NLRP 3 Inflammasome / 中国药房

OBJECTIVE：To investigate the effects and mechanism of puerarin （Pue） on hypoxia-induced pyroptosis of pulmonary artery smooth muscle cells （PASMCs）. METHODS ：PASMCs of rats as research objects were randomly divided into normoxia group ，hypoxia group and hypoxia+Pue group （0.2 mmol/L）. Except for normoxia group ，other groups were cultured with 5％ CO2 and 3％ O2 at 37 ℃ for 24 hours to establish hypoxia model. Western blot assay was used to detect the expression of pyroptosis related proteins [NOD-like receptor protein- 3 （NLPR3），caspase-1，interleukin-1 β （IL-1 β），apoptosis-associated speck-like protein （ASC）]. Lactate dehydrogenase （LDH）release assay was used to detect the release of LDH in cells ；Hoechst 33342/PI double staining test was adopted to detect the proportion of pyroptosis positive cells. PASMCs was randomly divided into normoxia group+control plasmid group ，hypoxia+control plasmid group ，hypoxia+over-expression plasmid group and hypoxia+ over-expression plasmid+Pue group. Except for the normoxia+control plasmid group ，the other groups were established hypoxia model by the same method. After transfection of control plasmid or NLRP 3 over-expression plasmid ，Western blot ，LDH release test and Hoechst 33342/PI double staining test were used to investigate whether Pue could inhibit hypoxia-induced PASMCs pyroptosis by interfering with the activity of NLRP 3 inflammasomes. RESULTS ：Compared with normoxia group ，the expression of pyroptosis related proteins ，the release of LDH and the proportion of pyroptosis positive cells were increased significantly in hypoxia group （P＜0.05 or P＜0.01）. Pue had the effect of reversing the above indexes （P＜0.05 or P＜0.01）. When the NLRP 3 inflammasome was over-expressed ，the expression of pyroptosis related proteins ，the release of LDH and the proportion of Δ 基金项目：黑龙江省自然科学基金资助项目（No.ZD201416） pyroptosis positive cells were increased significantly （P＜0.05 ＊教授，博士生导师 ，博士。研究方向 ：心血管药理学 。电话： or P＜0.01）. Pue could inhibit the above phenomenon through 0451-58853046。E-mail：zhangxd85@163.com regulating NLRP 3 inflammasome （P＜0.05 or P＜0.01）. 中国药房 2021年第32卷第11期 China Pharmacy 2021Vol. 32 No. 11 ·1337· CONCLUSIONS：Pue can significantly inhibit the hypoxia-induced pyroptosis of PASMCs by down-regulating the expression of pyroptosis related proteins ，reducing the release of LDH and proportion of pyroptosis positive cells. The mechanism is related to the activity inhibition of NLRP 3 inflammasome.

MicroRNA-143–5p modulates pulmonary artery smooth muscle cells functions in hypoxic pulmonary hypertension through targeting HIF-1α

This paper explores the potential mechanism of microRNA-143–5p regulation effects on pulmonary arterysmooth muscle cells (PASMCs) functions in hypoxic pulmonary hypertension (HPH) via targeting HIF-1a,which may offer a new idea for HPH therapy. PASMCs were transfected with mimics control/miR-143–5pmimics or inhibitor control/miR-143–5p inhibitor. We used Western blotting and RT-qPCR to detect the proteinand mRNA expressions, CCK-8 assay to detect cellular viability, Annexin V-FITC/PI staining and caspase3/cleaved caspase-3 protein to evaluate cellular apoptosis, transwell migration experiment for cellularmigration measurement and Dual luciferase reporter gene assay to prove the target of miR-143–5p. Cells underhypoxic condition presented the decreased protein and mRNA expressions of a-smooth muscle actin (SM-aactin), Myocardin, smooth muscle myosin heavy chain (SMMHC), and smooth muscle-22a (SM22a),Calponin1 and Hypoxia-inducible factor-1a(HIF-1a), the increased cell viability and miR-143–5p level; Overexpression of miR-143–5p obviously reduced vascular smooth muscle-specific contraction marker proteinlevels and cellular apoptosis, increased cellular migration of PASMCs with hypoxia stimulation; Low-expression of miR-143–5p caused the opposite changes, while co-transfected with Si HIF-1a blocked thebeneficial effects of miR-143–5p inhibition on PASMCs under hypoxia. MicroRNA-143–5p can promote thephenotype conversion, proliferation and migration of pulmonary artery smooth muscle cells under hypoxiccondition through direct targeting of HIF-1a.

Epalrestat inhibits PDGF-induced proliferation of rat PASMCs by inhibiting aldose reductase expression / 中国药理学与毒理学杂志

OBJECTIVE To explore the inhibitory effects of epalrestat (EPS) on platelet-derived growth factor (PDGF)-induced rat pulmonary artery smooth muscle cells proliferation by inhibiting aldose reductase (AR) expression.METHODS Primary rat pulmonary arterial smooth muscle cells (PASMCs) were prepared from the pulmonary artery of male 10-week-old Sprague-Dawley rats using explant method.PDGF 30 mg·L-1was given to induce cell proliferation.After PASMCs grew to 70%-80% conflu?ence, AR small-interferring RNA(ARsiRNA) was transfected with Lipofectamine 3000 into PASMCs. After 24 h,the expression and activity of AR were detected by reverse transcription-quantitative polymerase chain reaction (RT-qPCR),Western blotting and spectrophotometric method,respectively to investigate EPS on PASMCs proliferation and proliferating cell nuclear antigen (PCNA) and collagenⅠexpression induced by PDGF from in vitro. PASMCs (normal control, PDGF 30 mg·L-1, PDGF+EPS 1, 10 and 100 μmol·L-1,EPS 100 μmol·L-1)were treated according to groups.Cell proliferation was measured by BrdU marking and flow cytometry. The expressions of AR, PCNA and collagenⅠwere analyzed with RT-qPCR and Western blotting.RESULTS In cultured PASMCs,compared with normal control group, the application of exogenous PDGF-induced cell proliferation concomitantly up-regulated AR expres?sion and activity (P<0.01), and such effect was abolished by ARsiRNA. Compared with PDGF group, EPS attenuated PDGF-induced proliferation of PASMCs,expression of PCNA,and collagenⅠ(P<0.05, P<0.01),and the inhibitory effect of EPS was accompanied by inhibition of AR expression(P<0.05,P<0.01).CONCLUSION EPS inhibits PDGF-induced proliferation of PASMCs via inhibiting AR expression.

Alteration of tetraethylammonium-sensitive potassium current in pulmonary artery smooth muscle cells of pulmonary hypertension rats / 中国药理学通报

Aim To investigate the alteration of volt-age-depending potassium channel(KV) current in pul-monary arterial smooth muscle cells(PASMCs) of pul-monary hypertension (PH) rats, and the effect of tet-raethylammonium (TEA,a blocker of KV) on potassi-um channel current in different PH models. Methods The whole-cell patch clamp techniques were applied to record the KVcurrents from PASMCs cultured with Ham's F-12 (1% FBS). Furthermore, the effects of TEA on the KVcurrents were examined in different PH models. Results The whole-cell KVcurrents were ob-viously inhibited in PASMCs of chronic hypoxia (CH)and monocrotaline (MCT)-treated rats. TEA signifi-cantly decreased the whole-cell KVcurrents in PASMCs of control and PH rats,and the inhibitory effect of TEA was dramatically reduced in PH group. Conclusions The degree of the voltage-dependent potassium chan-nels opening is significantly inhibited in PASMCs of CH and MCT-treated rats,accordingly,the TEA-sen-sitive KVcurrents obviously decrease.

17β-estradiol Attenuates Hypoxia-induced Pulmonary Vascular Remodeling via Downregulating miRNA-21 Signaling Pathway / 中国循环杂志

Objectives: To explore the effect of 17β-estradiol (E2) on hypoxic pulmonary hypertension (HPH) and explore if the effects were mediated through suppressing pulmonary artery smooth muscle cells (PASMCs) proliferation by targeting miRNA-21 (miR-21). Methods: Animal experiment: A total of 32 healthy female SD rats with castrated surgery were randomly divided into 4 groups: normoxia group, normoxia+E2 group, hypoxia group, hypoxia+E2 group (n=8 each). The rats in normoxia+E2 group and hypoxia+E2 group received subcutaneous injection of E2 20 μg/kg/d, and the rest groups received subcutaneous injection of equal volume saline. The hypoxic groups were placed in the hypoxic chamber (24 hours per day for 8 weeks) to establish HPH model and normoxic groups were kept in the room air. The pulmonary artery remodeling, mean pulmonary artery pressure (mPAP), right ventricle hypertrophy index (RVHI) were observed. Real-time PCR and Western blot were used to detect the levels of proliferation cell nuclear antibody (PCNA) and miR-21 expression in pulmonary artery. In vitro: human pulmonary artery smooth muscle cells (hPASMCs) were randomly divided into 3 groups: normoxia group, hypoxia group, hypoxia+E2 group. The levels of cell proliferation in each group were tested by MTT after 24 hours. Real-time PCR and Western blot were used to detect the levels of PCNA and miR-21 in cells. Results: Animal experiment: compared with normoxia group, the hypoxia group showed obviously thickened pulmonary artery wall, increased mPAP and RVHI, and significantly increased expression of miR-21 and PCNA (P<0.01);above changed were significantly attenuated in hypoxia+E2 group (P<0.01). In vitro: compared with normoxia group, the hypoxia group showed obvious proliferation and significantly increased expression of miR-21 and PCNA (P<0.01);compared with hypoxia group, the proliferation of hPASMCs and expression of miR-21 and PCNA were obviously reduced in hypoxia+E2 group (P<0.01). Conclusions: E2 could effectively reduce mPAP, attenuate the degree of right heart hypertrophy and pulmonary vascular remodeling, the protective effect may be mediated through downregulating miR-21 and PCNA expression, and subsequently inhibiting the proliferation of hPASMCs.

Effects of endogenous sulfur dioxide on the oxidative stress induced by cobalt chloride in the rat pulmonary artery smooth muscle cells / 中华实用儿科临床杂志

Objective To investigate the effects of endogenous sulfur dioxide (SO2) on the oxidative stress induced by cobalt chloride (CoCl2) in the rat pulmonary artery smooth muscle cells (PASMCs).Methods Rat PASMCs were treated with 200 μ mol/L CoCl2 to mimic the hypoxia insult.Endogenous SO2 generating enzyme aspartate aminotransferase 1 (AAT1) expression was upregulated or downregulated (AAT1 sh) by transfection with lentivirus.Rat PASMCs were randomly divided into 8 groups:vehicle group,vehicle + CoCl2 group,AAT1 group,AAT1 + CoCl2 group,scramble group,scramble + SO2 group,AAT1 sh group and AAT1 sh + SO2 group.SO2 donor Na2 SO3/NaHSO3 at concentration of 100 μ mol/L were added in scramble + SO2 group and AAT1sh + SO2 group.The expressions of AAT1,superoxide dismutase 1 (SOD1) and SOD2 in PASMCs were detected by Western blot method.In situ SO2 content in PASMCs was detected by fluorescent probe.The superoxide anions in PASMCs were labeled by dihydroethidium (DHE) probe under fluorescent microscope.Results Compared with the vehicle group,the levels of SO2 and the expressions of AAT1 (0.221 ± 0.002 vs.0.446 ± 0.004),SOD1 (0.076 ± 0.028 vs.0.171 ± 0.019) and SOD2 (0.080 ± 0.031 vs.0.196 ± 0.018) significantly decreased (all P ＜ 0.01),and superoxide anion increased in rat PASMCs of vehicle + CoCl2 group.Meanwhile,compared with vehicle + CoCl2 group,the levels of SO2 and the expressions of AAT1 (0.839 ± 0.056 vs.0.221 ± 0.002),SOD1 (0.177 ± 0.020 vs.0.076 ± 0.028) and SOD2 (0.195 ±0.018 vs.0.080-± 0.031) markedly increased (all P ＜ 0.01),and superoxide anion decreased in rat PASMCs of AAT1 + CoCl2 group.On the contrary,compared with the scramble group,the levels of SO2 and the expressions of AAT1 (0.062 ±0.017 vs.0.354 ±0.034),SOD1 (0.054 ±0.029 vs.0.157 ±0.023) and SOD2(0.180 ±0.100 vs.0.586 ± 0.176)significantly decreased (all P ＜ 0.01),and superoxide anion increased in rat PASMCs of AAT1sh group.Furthermore,compared with the AAT1 sh group,the levels of SO2 and the expressions of SOD1 (0.155 ± 0.022vs.0.054 ± 0.029) and SOD2 (0.578 ± 0.200 vs.0.180 ± 0.100) significantly increased (all P ＜ 0.01),and superoxide anion decreased in rats PASMCs of AAT1sh + SO2 group.Conclusion Endogenous SO2/AAT1 inhibits CoCl2-induced oxidative stress in rat PASMCs.

Effect of hypoxic pulmonary vasoconstriction on hypoxic pulmonary hypertension / 中国药理学通报

Sustained hypoxic pulmonary vasoconstriction (HPV ) as experienced at high altitude can lead to hypoxic pulmonary hypertension(HPH).HPV,a special physiological phenomenon of lung,is the physiological reflex of organism in hypoxic envi-ronment.However,in high altitude hypoxic environment,the sustained HPV can lead to pulmonary vascular remodeling and right ventricular hypertrophy,at the same time,the degree of hypoxia in alveoli can be aggravated.Vicious circle of hypoxia is formed,further causing the severe high altitude sickness such as pulmonary edema and pulmonary heart disease.HPV appears in preliminary of HPH,but in the chronic phase,irreversible hy-poxic pulmonary vascular remodeling forms.Therefore,studying the mechanism of HPV and the effect of HPV in HPH can pro-vide targets and ideas for the prevention and treatment of high al-titude sickness. Additionally, in preliminary stage of HPV, prompt treatment is critical for the prevention of high altitude sickness.However,the mechanism of HPV and its roles in HPH are still not fully elucidated in current studies.This paper sum-marizes the studies about HPV in HPH of recent years,aiming to provide references for researchers and clinical treatment in this research field.

Angiotensin II inhibits Na+/K+ATPase activity in pulmonary artery smooth muscle cells via glutathionylation and with the involvement of a 15.6 kDa inhibitor protein.

The role of angiotensin II in regulating Na+/K+-ATPase activity has been investigated in bovine pulmonary artery smooth muscle cells (BPASMCs). Our study reveals that angiotensin II inhibits the Na+/K+ATPase activity via glutathionylation of the pump with the involvement of an increase in NADPH oxidase-derived O2.-. Additionally, angiotensin II treatment to the cells increases the inhibitory potency of the 15.6 kDa inhibitor towards the Na+/K+ATPase activity.

Effects of inhibiting myosin light chain kinase on endothelin-1 induced proliferation and apoptosis of pulmonary arterial smooth muscle cells in rats / 中国病理生理杂志

AIM: To investigate the effect of inhibiting myosin light chain kinase ( MLCK) on endothelin-1 (ET-1) induced proliferation and apoptosis of rat pulmonary artery smooth muscle cells (PASMCs).METHODS: Rat PASMCs were cultured and stimulated with ET-1.The cells were randomly divided into control group , ET-1 group and ET-1+MLCK inhibitor group (ET-1+M).Western blotting, MTT assay, [3H]-TdR incorporation and flow cytometry were employed to test the expression of myosin light chain (MLC) and MLCK, cell proliferation, cell cycle and apoptotic rate of PASMCs ,respectively .The phosphorylation of MLC was determined by glycerol-PAGE coupled with Western blotting .RE-SULTS:Compared with control group , the protein expression of MLCK and MLC phosphorylation significantly enhanced af -ter ET-1 stimulation.ET-1 markedly induced the proliferation and decreased the percentage of apoptotic rate in the PASMCs.However, pretreatment with ML-7, a MLCK inhibitor, significantly reversed the above effects induced by ET-1. CONCLUSION:MLCK inhibitor effectively inhibits the ET-1-induced proliferation and the cell cycle progression .

The expression changes of miR-214 in hypoxic induced pulmonary artery smooth muscle cells of rats / 重庆医学

Objective To observe the changes of microRNA‐214 (miR‐214) expression in rat pulmonary artery smooth mus‐cle cells (PASMCs) induced by different hypoxia time ,and lay the foundation to explore the effect and mechanism of regulation of miR‐214 on PASMCs proliferation .Methods The primary cultured PASMCs were cultured under hypoxic 0 h ,6 h ,12 h ,24 h ,48 h ,respectively .The real time quantitative PCR was used to detect miR‐214 expression in each group PASMCs .Results The ex‐pression of miR‐214 in hypoxia group PASMCs was sustained as time increased ,apart from hypoxic hypoxia 6h group and 0h group ,the expression of miR‐214 was no significant difference (P>0 .05);the expression of miR‐214 among other groups PASMCs was significantly different (P<0 .05) .Conclusion The expression of miR‐214 in PASMCs increased after induction of hypoxia .We speculated that miR‐214 may be involved in the regulation of hypoxia induced PASMCs proliferation .

AICAR Blocks the Proliferation of Pulmonary Artery Smooth Muscle Cells by Inhibition of Cell Cycle in G0/G1 / 医学研究杂志

Objective To establish the PDGF-BB-induced proliferation of rat pulmonary artery smooth muscle cells(PASMCs), and investigate the effects of the AMPK agonist AICAR on the cell cycle of PASMCs, in order to search new drugs for prevention of pulmo-nary vascular remodeling. Methods 20ng/ml PDGF-BB was used to induced the proliferation of PASMCs, and the effect of 0. 5mmol/L AICAR on the proliferation of PASMCs was observed. Western blot was used to detect the total and phosphorylated AMPK. The prolifer-ation of PASMCs was determined by CCK-8. The mRNA expression of cyclinD1, cyclinE and CDK2/4/6 were detected by flow cytometry analysis cell cycle,quantitative real-time PCR. Results Western blot Results indicated AICAR could promote the activation of AMPK. CCK-8 test Results showed that AICAR blocked the proliferation of PASMCs induced by PDGF-BB. Flow cytometry analysis indicated that AICAR arrested the cell cycle in G0/G1 to S phase. RT-PCR Results demonstrated that AICAR inhibited the mRNA expression of cy-clinD1, cyclinE and CDK2/4/6. Conclusion The AMPK agonist AICAR can block the proliferation of PASMCs induced through arrest cell cycle in G0/G1-S phase by regulation the mRNA expression of cyclin D1, cyclinE, CDK2/4/6, and AICAR has a potential applica-tion in preventing pulmonary vascular remodeling.

Effect of YC-1 on the hypoxia-induced proliferation of HPASMCs and the P53 expression / 基础医学与临床

Objective_To investigate the effects of hypoxia-inducible factor-1 alpha ( HIF-1α) inhibitor YC-1 on hy-poxia induced human pulmonary artery smooth muscle cells ( HPASMCs) proliferation, apoptosis and the expression of P53, and to explore the molecular mechanism in the processes.Methods_HPASMCs were cultured in DMEM me-dium supplemented with 10%FBS in vitro.Then divided them into four groups:normoxia, hypoxia and hypoxia+YC-1(0.01 and 0.05 mmol/L).Cell proliferation was measured by CCK-8 and apoptosis was detected by flow cytom-etry.The expressions of HIF-1αand P53 were tested by Western blot, and the mRNA expression of P53 was tested by RT-PCR.Results_Hypoxia can promote the proliferation of HPASMCs.Treatment of HPASMCs with different concentrations of YC-1 intervention for 24h obviously dropped proliferation rate (P<0.05), and the apoptosis rate increased significantly (P<0.05).YC-1 can also down-regulate the expression of HIF-1αand up-regulate the ex-pression of P53 significantly ( P<0.05 ) .Conclusions_YC-1 can inhibit hypoxia-induced HPASMCs proliferation and promote apoptosis, the mechanism is potentially related to the up-regulation of P53 expression.

Effect of 2,3,4′,5-Tetrahydroxystilbene-2 -O -beta -D-glucoside on the Proliferation of Pulmonary Artery Smooth Muscle Cells In-duced by Hypoxia / 医学研究杂志

Objective To investigate the effects of the 2,3,4′,5-Tetrahydroxystilbene -2-O-beta-D-glucoside on the prolif-eration of PASMCs induced by hypoxia , in orde to search new drugs for the treatment and prevention of hypoxic pulmonary vascular remod -eling.Methods 3%O2 hypoxia was used to induced the proliferation of PASMCs .After hypoxic and TSG treatment for 24h, cell growth was determined by cell counting kit -8 ( CCK-8 ) , cell cycle was analysed by flow cytometry , the mRNA expression of HIF -1αwas measured by quantitative real -time PCR, and the reactive oxygen species ( ROS) production was determined by the fluorescence micro-plate reader .Results TSG can block the proliferation of PASMCs through G 0/G1 to S phase of the cell cycle arrest without cell cytotoxic-ity.Further experiments showed that TSG blocking the proliferation of PASMCs was associated suppression the mRNA expression of HIF -1αand the production of intracellular ROS in hypoxia -stimulated-PASMCs.Conclusion TSG can inhibit the proliferation of pulmo-nary artery smooth muscle cells induced by hypoxia through suppression the mRNA expression of HIF -1αand the production of intracel-lular ROS.

Effects of Kv1.5 on proliferation and apoptosis of rat PASMCs under hy-poxia+hypercapnia condition and relationship with MAPK pathway / 中国病理生理杂志

AIM:To investigate the effects of voltage-dependent K +channel 1.5 (Kv1.5) on the proliferation and apoptosis of rat pulmonary artery smooth muscle cells (PASMCs) under hypoxia+hypercapnia condition and the relation-ship with mitogen-activated protein kinase(MAPK) signal pathway.METHODS:The PASMCs isolated from the male SD rat were cultured under hypoxia +hypercapnia condition, and randomly divided into normal group (N group), hypoxia+hyper-capnia group (HH group), hypoxia+hypercapnia+DMSO incubation group (HD group), hypoxia+hypercapnia +U0126 (an extracellular signal-regulated kinase 1/2 inhibitor) incubation group (HU group), hypoxia+hypercapnia+SB203580 (a p38 mitogen-activated protein kinase inhibitor ) incubation group (HS group), and hypoxia+hypercapnia+anisomycin (an agonist of MAPK) incubation group (HA group).Cell Counting Kit-8 was used to detect the cell viability.The protein expression of Kv1.5, PCNA and Bax was detected by Western blotting .RESULTS:Compared with N group , the cell via-bility and PCNA protein expression in HH group and HD group were significantly raised (P0.05 ) .Compared with HD group , the cell viability and PCNA protein expression in HU group , HS group and HA group were decreased (P<0.05 or P<0.01), but Kv1.5 protein and Bax protein were raised (P<0.01), with the most significant changes in HA group .CONCLUSION:The regulation of Kv1.5 to the proliferation and apoptosis of PASMCs under hy-poxia+hypercapnia condition might have a relationship with the activation of MAPK signal pathway .

C-reactive protein induced inflammatory response in pulmonary artery smooth muscle cell by nuclear factor-κB pathway / 中华急诊医学杂志

Objective To examine the impact of C-reactive protein (CRP) on the expression of interleukin-6 (IL-6), inflammatory cytokine, in cultured human pulmonary artery smooth muscle cells (hPASMCs) in order to find out the cause of pulmonary artery hypertension (PAH). Method The hPASMCs were cultured and stimulated by different concerntrations of CRP (5 - 200 μg/ml) for different lengths of time. The activity of nuclear factor-κB (NF-κB) was evaluated by electrophoretic gel mobility shift assay (EMSA). The expression of IL-6 mRNA and the level of IL-6 protein were measured by using real-time PCR and ELISA, respectively. Results CRP increased IL-6 production in hPASMCs in a dose-dependent manner. The increase in IL-6 at concerntration of 200 μg/mL in the CRP group was as high as 2.8times that in the control group. CRP also significantly induced the activation of NF-κB in hPASMCs. The effect of CRP on the inflammatory cytokine, IL-6, was inhibited by the specific FcγⅡa receptor antibody.Conclusions In vitro, CRP increases the production of IL-6 in hPASMCs mediated by FcγⅡa receptor and NF-κB translocation. These data offer important insights into the role of CRP in the pathogenesis of PAH.

Influence of the 15-HETE on cytosolic [ Ca2+] i of the rabbit pulmonary artery smooth muscle cells

Extracellular Ca2+ influx was blocked by L-type Ca2+ channel blocker nifedipine to observe the effects of 15-hydroxyeicosatetraenoic acid on the constriction of rabbit pulmonary artery rings and on the changes of Ca2+ level in the rabbit pulmonary artery smooth muscle cells, and further to investigate the mechanism of the calcium mobilization induced by the 15-HETE under hypoxic conditions. The effect of extracellular Ca2+ on tension of the rabbit PA rings was also studied. Nifedipine (10 µ mol/L) had no effect on 1 µ mol/L 15-hydroxyeicosatetraenoic acid induced vasoconstriction under normoxic and hypoxic conditions. Intracellular Ca2+ increased markedly in the 15-HETE group (cells were exposed to 1 µ mol/L 15-HETE for 8 min during culture) compared to the control group (P < 0.05). The study demonstrated that the 15-HETE could induce the elevation of Ca2+ in the pulmonary artery smooth muscle cells and the elevated calcium came from the release of the intracellular calcium.