AIM:This study aimed to confirm the glycolytic inhibitory activity of 3-bromopyruvic acid(3BP)and to assess whether this inhibition could ameliorate hypoxia-induced pulmonary hypertension in rats.METHODS:PAH model rats were generated from normal SD rats via exposure to normal pressure and hypoxia.Intervention groups I and II(6 rats per group)were then intraperitoneally injected with 3BP(15 mg/kg),and the normal and hypoxia groups(6 rats per group)were given the same amount of normal saline for a total of 21 d.The average pulmonary artery pressure of the rats in each group was measured via right heart catheterisation,and hilar tissue measurements.The right ventricle(RV),left ventricle,and interventricular septum(LV+S)were weighed,and the ratio of RV/(LV+S)was calculated as an index of right ventricular hypertrophy.Right lower lung tissues were fixed in 4%paraformaldehyde-PBS buffer,sec-tioned in conventional paraffin(5 μm thick),stained with HE and Masson,photographed under a microscope.Then the thickness ratio of the tunica media and the area ratio of collagen fibres were calculated.The expression of pyruvate kinase isozyme type M2(PKM2),nucleotide-binding oligomerization domain-like receptor protein 3(NLRP3),and pyruvate de-hydrogenase(PDH)proteins in the hilar tissues of each group were detected by western blot,whereas interleukin-1β(IL-1β)and IL-18 contents were detected using ELISA,and lactic acid content was detected using a lactic acid kit.RE-SULTS:The results showed that 3-brpa effectively inhibited glycolysis and significantly improved hypoxia-induced pulmo-nary hypertension in rats.Compared with the hypoxia group,in intervention group II,PKM2 expression was decreased(P<0.05),PDH expression increased significantly(P<0.01),and NLRP3 expression was decreased(P<0.05).The IL-18 and IL-1β contents decreased(P<0.05 or P<0.01,respectively).Pulmonary hemodynamic indexes showed that the pro-portion of the right ventricle and the mean pressure of the pulmonary artery decreased(P<0.05 or P<0.01,respectively).The HE and Masson staining results showed that the thickness ratio of the tunica media and the area ratio of collagen fibres decreased significantly(P<0.01).Lactic acid content was significantly decreased(P<0.01).CONCLUSION:This study showed that 3BP can inhibit glycolysis and alleviate hypoxia-induced pulmonary hypertension in rats.

AIM:To investigate the effect and mechanism of panax notoginseng saponins(PNS)inhibiting the proliferation of pulmonary artery smooth muscle cells(PASMCs)in rats under the ef-fect of monocrotaline(MCT).METHODS:PASMCs cultured in vitro were randomly divided into the normal control(Control)group,the monocrotaline(MCT)group,the panax notoginseng saponins(PNS)group,the knockdown(M+Si ADAM10)group,the knockdown postconditioning(M+P+Si ADAM10)group,the overexpression(M+OE AD-AM10)group,and the overexpression postcondi-tioning(M+P+OE ADAM10)group.After the model was constructed,the cell viability of each group was measured using the CCK-8 assay,along with Western blot utilized to detect the expression of proliferating cell nuclear antigen(PCNA),disinteg-rin metalloproteinase 10(ADAM10),and notch ho-mology protein-3(Notch3)at the cellular neurogen-ic locus,respectively.RESULTS:Under the effect of MCT,the viability of PASMCs was significantly en-hanced(P<0.05 or P<0.01);0-400 mg/L PNS was not toxic to the viability of normal cells,and 100 mg/L PNS could significantly inhibit the MCT-in-duced viability(P<0.01).After the knockdown of ADAM10,the viability of PASMCs significantly de-clined(P<0.01),and the expression of PCNA protein was significantly decreased(P<0.05),evidently in the M+P+Si ADAM10 group.Meanwhile,the ex-pression of ADAM10 and Notch3 protein was signif-icantly decreased(P<0.05 or P<0.01),evidently in the M+P+Si ADAM10 group.After overexpression of ADAM10,the viability of PASMCs was significant-ly enhanced(P<0.01),the expression of PCNA pro-tein was significantly increased(P<0.01),the PCNA value was slightly higher(P>0.05),and the expres-sion of ADAM10 and Notch3 protein was signifi-cantly elevated(P<0.05)in the M+P+OE ADAM10 group.Additionally,PASMCs overexpressing AD-AM10 with concomitant PNS exhibited a significant decrease in the expression of PCNA protein com-pared with PASMCs knocking down ADAM10(P<0.01),and the expression of ADAM10 and Notch3 protein declined to varying degrees(P>0.05).CON-CLUSION:Panax notoginseng saponins can mitigate MCT-induced PASMCs proliferation in rats by inhib-iting the ADAM10/Notch3 signaling pathway.

AIM:To investigate the effect and mechanism of panax notoginseng saponins(PNS)inhibiting the proliferation of pulmonary artery smooth muscle cells(PASMCs)in rats under the ef-fect of monocrotaline(MCT).METHODS:PASMCs cultured in vitro were randomly divided into the normal control(Control)group,the monocrotaline(MCT)group,the panax notoginseng saponins(PNS)group,the knockdown(M+Si ADAM10)group,the knockdown postconditioning(M+P+Si ADAM10)group,the overexpression(M+OE AD-AM10)group,and the overexpression postcondi-tioning(M+P+OE ADAM10)group.After the model was constructed,the cell viability of each group was measured using the CCK-8 assay,along with Western blot utilized to detect the expression of proliferating cell nuclear antigen(PCNA),disinteg-rin metalloproteinase 10(ADAM10),and notch ho-mology protein-3(Notch3)at the cellular neurogen-ic locus,respectively.RESULTS:Under the effect of MCT,the viability of PASMCs was significantly en-hanced(P<0.05 or P<0.01);0-400 mg/L PNS was not toxic to the viability of normal cells,and 100 mg/L PNS could significantly inhibit the MCT-in-duced viability(P<0.01).After the knockdown of ADAM10,the viability of PASMCs significantly de-clined(P<0.01),and the expression of PCNA protein was significantly decreased(P<0.05),evidently in the M+P+Si ADAM10 group.Meanwhile,the ex-pression of ADAM10 and Notch3 protein was signif-icantly decreased(P<0.05 or P<0.01),evidently in the M+P+Si ADAM10 group.After overexpression of ADAM10,the viability of PASMCs was significant-ly enhanced(P<0.01),the expression of PCNA pro-tein was significantly increased(P<0.01),the PCNA value was slightly higher(P>0.05),and the expres-sion of ADAM10 and Notch3 protein was signifi-cantly elevated(P<0.05)in the M+P+OE ADAM10 group.Additionally,PASMCs overexpressing AD-AM10 with concomitant PNS exhibited a significant decrease in the expression of PCNA protein com-pared with PASMCs knocking down ADAM10(P<0.01),and the expression of ADAM10 and Notch3 protein declined to varying degrees(P>0.05).CON-CLUSION:Panax notoginseng saponins can mitigate MCT-induced PASMCs proliferation in rats by inhib-iting the ADAM10/Notch3 signaling pathway.

AIM:This study aimed to confirm the glycolytic inhibitory activity of 3-bromopyruvic acid(3BP)and to assess whether this inhibition could ameliorate hypoxia-induced pulmonary hypertension in rats.METHODS:PAH model rats were generated from normal SD rats via exposure to normal pressure and hypoxia.Intervention groups I and II(6 rats per group)were then intraperitoneally injected with 3BP(15 mg/kg),and the normal and hypoxia groups(6 rats per group)were given the same amount of normal saline for a total of 21 d.The average pulmonary artery pressure of the rats in each group was measured via right heart catheterisation,and hilar tissue measurements.The right ventricle(RV),left ventricle,and interventricular septum(LV+S)were weighed,and the ratio of RV/(LV+S)was calculated as an index of right ventricular hypertrophy.Right lower lung tissues were fixed in 4%paraformaldehyde-PBS buffer,sec-tioned in conventional paraffin(5 μm thick),stained with HE and Masson,photographed under a microscope.Then the thickness ratio of the tunica media and the area ratio of collagen fibres were calculated.The expression of pyruvate kinase isozyme type M2(PKM2),nucleotide-binding oligomerization domain-like receptor protein 3(NLRP3),and pyruvate de-hydrogenase(PDH)proteins in the hilar tissues of each group were detected by western blot,whereas interleukin-1β(IL-1β)and IL-18 contents were detected using ELISA,and lactic acid content was detected using a lactic acid kit.RE-SULTS:The results showed that 3-brpa effectively inhibited glycolysis and significantly improved hypoxia-induced pulmo-nary hypertension in rats.Compared with the hypoxia group,in intervention group II,PKM2 expression was decreased(P<0.05),PDH expression increased significantly(P<0.01),and NLRP3 expression was decreased(P<0.05).The IL-18 and IL-1β contents decreased(P<0.05 or P<0.01,respectively).Pulmonary hemodynamic indexes showed that the pro-portion of the right ventricle and the mean pressure of the pulmonary artery decreased(P<0.05 or P<0.01,respectively).The HE and Masson staining results showed that the thickness ratio of the tunica media and the area ratio of collagen fibres decreased significantly(P<0.01).Lactic acid content was significantly decreased(P<0.01).CONCLUSION:This study showed that 3BP can inhibit glycolysis and alleviate hypoxia-induced pulmonary hypertension in rats.

AIM:To investigate the effects of sodium hydrosulfide(NaHS)on hexokinase 2(HK2)-nucleo-tide-binding oligomerization domain-like receptor protein 3(NLRP3)-gasdermin D(GSDMD)pathway and pyroptosis in-duced by lung ischemia/reperfusion(I/R)in rats.METHODS:Male Sprague-Dawley rats were divided into 6 groups:control group,control+NaHS group,I/R group,low-dose NaHS+I/R(L+I/R)group,medium-dose NaHS+I/R(M+I/R)group,and high-dose NaHS+I/R(H+I/R)group,with 6 rats in each group.The NaHS was administered via intraperi-toneal injection at 1.5 mL,30 min before modeling.The left lung tissues were collected 30 min after ischemia and 1 h af-ter reperfusion,and the wet/dry weight ratio and total lung water content were recorded.Hematoxylin-eosin(HE)staining was used to examine lung tissue morphological changes.The levels of malondialdehyde(MDA),myeloperoxidase(MPO)and lactate in lung tissues were measured with test kits.ELISA was employed to determine the levels of interleukin-1β(IL-1β)and IL-18.The expression of glycolysis-and pyroptosis-related indicators was analyzed by Western blot,qRT-PCR and immunofluorescence staining.RESULTS:Compared with control group,the rats in NaHS group showed no signifi-cant differences in all laboratory tests(P>0.05).The rats in I/R group exhibited significant lung injury,oxidative stress,increased lactate level,and up-regulated glycolysis and pyroptosis(P<0.05 or P<0.01).Compared with I/R group,the indicators in L+I/R group showed a downward trend(P<0.01)or no difference(P>0.05),while those in M+I/R group dis-played a significant reduction(P<0.05 or P<0.01).However,the indexes in H+I/R group exhibited no significant dif-ferences in these tests(all P>0.05).CONCLUSION:A moderate dose(56 μmol·L-1·kg-1)of NaHS mitigated the oc-currence of pyroptosis by inhibiting the HK2-NLRP3-GSDMD pathway,thus contributing to the attenuation of lung I/R in-jury in rats.

AIM:To investigate the regulatory role of retinoid X receptor(RXR)in oxidative stress response of rat type Ⅱ alveolar epithelial cells(AECII)induced by hypoxia/reoxygenation(HR).METHODS:The AECII were di-vided into control(C)group,HR group,HR+solvent dimethyl sulfoxide(DMSO)group(HD group),HR+RXR agonist 9-cis-retinoic acid(9-RA)group(RA group),and HR+RXR antagonist HX531 group(HX group).Cell Counting Kit-8(CCK-8)method was used to measure the cell viability.Immunofluorescence staining was used to detect the expression of surfactant protein A(SP-A)and RXRα in AECII.Kits were detected to the levels of superoxide dismutase(SOD)and malondialdehyde(MDA)in cells.Transmission electron microscopy was used to observe the ultrastructural changes of the cells.Western blot was used to detect the protein level of nuclear factor E2-related factor 2(Nrf2).RT-PCR was used to detect the expression level of Nrf2 mRNA.RESULTS:Compared with C group,the cell viability and SOD activity in HR,HD,RA and HX groups were decreased significantly(P<0.05),the MDA content were increased significantly(P<0.05),the Nrf2 mRNA and protein expression levels were decreased significantly(P<0.05 or P<0.01),and the immuno-fluorescence expression of RXRα was significantly increased(P<0.01).Compared with HR and HX groups,the cells in RA group showed significantly increased cell viability(P<0.05),increased SOD activity(P<0.05),decreased MDA con-tent(P<0.05),increased Nrf2 mRNA and protein expression levels(P<0.01),and significantly increased immunofluo-rescence expression of RXRα(P<0.01).CONCLUSION:Hypoxia/reoxygenation can aggravate the oxidative stress re-sponse of rat AECII,and RXR agonist intervention can alleviate HR-induced rat AECII injury by inhibiting oxidative stress.

AIM:To investigate the effect and mechanism of the exogenous hydrogen sulfide donor GYY4137 on hypoxia-induced proliferation of rat pulmonary artery smooth muscle cells(PASMCs).METHODS:Rat PASMCs in optimal growth condition were used.Once the cell density reached 60%～70%,the cells were serum starved for 24 h.The cells were then randomly divided into four groups:normal group,normal+GYY4137 group,hypoxia group,and hypoxia+GYY4137 group.A CCK-8 assay was used to determine the safe concentration range of GYY4137 that exerted no adverse effects on normal cells,and the optimal concentration of GYY4137 to inhibit hypoxia-induced proliferation of PASMCs was identified.EdU staining was employed to assess PASMCs proliferation in each group.Western blot analysis was conducted to evaluate the expression of proliferating cell nuclear antigen(PCNA)and proteins related to glycolysis and pyroptosis in PASMCs.Lactic acid content was quantified using a lactic acid assay kit.Immunofluorescence was used to detect the pro-tein expression of hexokinase 2(HK2)and nucleotide-binding oligomerization domain-like receptor protein 3(NLRP3)in PASMCs,and the levels of interleukin-1β(IL-1β)and IL-18 in PASMCs were measured using ELISA.RESULTS:The effective concentration of GYY4137 in inhibiting hypoxia-induced viability of PAMSCs was 100 μmol/L(P＜0.05).Com-pared with the hypoxia group,the hypoxia+GYY4137 group showed a significant decrease in PCNA protein expression(P＜0.05),reduced PAMSCs proliferation(P＜0.01),decreased HK2 and pyruvate kinase isozyme type M2(PKM2)protein expression(P＜0.05,P＜0.01),increased pyruvate dehydrogenase(PDH)protein expression(P＜0.05),and reduced lac-tic acid content(P＜0.01).Additionally,the expression of pyroptosis-related proteins was significantly decreased(P＜0.015,P＜0.01),and immunofluorescence revealed a significant decrease in HK2 and NLRP3 expression(P＜0.01).ELISA results showed that IL-1β and IL-18 protein levels were significantly decreased(P＜0.05,P＜0.01).CONCLU-SION:GYY4137 inhibits hypoxia-induced proliferation of rat PASMCs by regulating glycolysis and pyroptosis.

AIM:To investigate the effect and mechanism of the exogenous hydrogen sulfide donor GYY4137 on hypoxia-induced proliferation of rat pulmonary artery smooth muscle cells(PASMCs).METHODS:Rat PASMCs in optimal growth condition were used.Once the cell density reached 60%～70%,the cells were serum starved for 24 h.The cells were then randomly divided into four groups:normal group,normal+GYY4137 group,hypoxia group,and hypoxia+GYY4137 group.A CCK-8 assay was used to determine the safe concentration range of GYY4137 that exerted no adverse effects on normal cells,and the optimal concentration of GYY4137 to inhibit hypoxia-induced proliferation of PASMCs was identified.EdU staining was employed to assess PASMCs proliferation in each group.Western blot analysis was conducted to evaluate the expression of proliferating cell nuclear antigen(PCNA)and proteins related to glycolysis and pyroptosis in PASMCs.Lactic acid content was quantified using a lactic acid assay kit.Immunofluorescence was used to detect the pro-tein expression of hexokinase 2(HK2)and nucleotide-binding oligomerization domain-like receptor protein 3(NLRP3)in PASMCs,and the levels of interleukin-1β(IL-1β)and IL-18 in PASMCs were measured using ELISA.RESULTS:The effective concentration of GYY4137 in inhibiting hypoxia-induced viability of PAMSCs was 100 μmol/L(P＜0.05).Com-pared with the hypoxia group,the hypoxia+GYY4137 group showed a significant decrease in PCNA protein expression(P＜0.05),reduced PAMSCs proliferation(P＜0.01),decreased HK2 and pyruvate kinase isozyme type M2(PKM2)protein expression(P＜0.05,P＜0.01),increased pyruvate dehydrogenase(PDH)protein expression(P＜0.05),and reduced lac-tic acid content(P＜0.01).Additionally,the expression of pyroptosis-related proteins was significantly decreased(P＜0.015,P＜0.01),and immunofluorescence revealed a significant decrease in HK2 and NLRP3 expression(P＜0.01).ELISA results showed that IL-1β and IL-18 protein levels were significantly decreased(P＜0.05,P＜0.01).CONCLU-SION:GYY4137 inhibits hypoxia-induced proliferation of rat PASMCs by regulating glycolysis and pyroptosis.