AIM:To investigate the potential mechanisms by which cell division cycle protein 42(Cdc42)regulates endothelial-mesenchymal transition(EndMT)in pulmonary hypertension(PH).METHODS:The pulmonary hypertension(PH)model was established using Sugen-5416 combined with hypoxia.Twenty-four C57BL/6 mice were ran-domly divided into four groups:normoxia control(CON)group,normoxia+ML141(CON+ML141)group,Sugen-5416+hypoxia(SuHx)group,and SuHx+ML141 group,with 6 mice in each group.After 4 weeks,right ventricular systolic pressure(RVSP)and cardiac ultrasound parameters were measured,and lung tissues were collected for immunofluores-cence staining.Pulmonary microvascular endothelial cells(PMVECs)were isolated using magnetic bead sorting.Calcium imaging was performed to assess Ca2+signaling,and Western blot was used to detect EndMT-related proteins as well as stromal interaction molecule 1(STIM1)and Orai1 expression.RESULTS:In the SuHx group,mice exhibited signifi-cantly increased RVSP,Fulton index(right ventricle/left ventricle+septum),end-diastolic right ventricular free wall thick-ness(RVEDWT),and end-systolic right ventricular free wall thickness(RVESWT)(P<0.01).Conversely,pulmonary artery acceleration time/pulmonary artery ejection time(PAT/PET)and tricuspid annulus plane systolic excursion(TAPSE)were significantly reduced(P<0.01).The Cdc42 inhibitor ML141 ameliorated these changes.The SuHx group exhibited a significant decrease in CD31 fluorescence intensity in pulmonary vascular endothelial cells(P<0.01),a marked increase in α-smooth muscle actin(α-SMA)fluorescence intensity in smooth muscle cells(P<0.01),and the emergence of CD31/α-SMA co-localization.These alterations were reversed by ML141.Hypoxia induced EndMT in PM-VECs,characterized by decreased CD31 and vascular endothelial cadherin(VE-cadherin)along with increased α-SMA and vimentin(P<0.01),which was suppressed by ML141(P<0.01).Hypoxia activated store-operated calcium entry(SOCE),enhancing intracellular Ca2? release,extracellular Ca2? influx,and basal Ca2? levels(P<0.01),while upregulat-ing STIM1 and Orai1 expression(P<0.01).These changes were reversed by ML141.Furthermore,both ML141 and STIM1 knockdown inhibited the upregulation of EndMT-related transcription factors Snail and Twist(P<0.05).CON-CLUSION:Cdc42 may participate in EndMT in PH by regulating store-operated calcium channels in pulmonary microvas-cular endothelial cells.

AIM:To investigate the potential mechanisms by which cell division cycle protein 42(Cdc42)regulates endothelial-mesenchymal transition(EndMT)in pulmonary hypertension(PH).METHODS:The pulmonary hypertension(PH)model was established using Sugen-5416 combined with hypoxia.Twenty-four C57BL/6 mice were ran-domly divided into four groups:normoxia control(CON)group,normoxia+ML141(CON+ML141)group,Sugen-5416+hypoxia(SuHx)group,and SuHx+ML141 group,with 6 mice in each group.After 4 weeks,right ventricular systolic pressure(RVSP)and cardiac ultrasound parameters were measured,and lung tissues were collected for immunofluores-cence staining.Pulmonary microvascular endothelial cells(PMVECs)were isolated using magnetic bead sorting.Calcium imaging was performed to assess Ca2+signaling,and Western blot was used to detect EndMT-related proteins as well as stromal interaction molecule 1(STIM1)and Orai1 expression.RESULTS:In the SuHx group,mice exhibited signifi-cantly increased RVSP,Fulton index(right ventricle/left ventricle+septum),end-diastolic right ventricular free wall thick-ness(RVEDWT),and end-systolic right ventricular free wall thickness(RVESWT)(P<0.01).Conversely,pulmonary artery acceleration time/pulmonary artery ejection time(PAT/PET)and tricuspid annulus plane systolic excursion(TAPSE)were significantly reduced(P<0.01).The Cdc42 inhibitor ML141 ameliorated these changes.The SuHx group exhibited a significant decrease in CD31 fluorescence intensity in pulmonary vascular endothelial cells(P<0.01),a marked increase in α-smooth muscle actin(α-SMA)fluorescence intensity in smooth muscle cells(P<0.01),and the emergence of CD31/α-SMA co-localization.These alterations were reversed by ML141.Hypoxia induced EndMT in PM-VECs,characterized by decreased CD31 and vascular endothelial cadherin(VE-cadherin)along with increased α-SMA and vimentin(P<0.01),which was suppressed by ML141(P<0.01).Hypoxia activated store-operated calcium entry(SOCE),enhancing intracellular Ca2? release,extracellular Ca2? influx,and basal Ca2? levels(P<0.01),while upregulat-ing STIM1 and Orai1 expression(P<0.01).These changes were reversed by ML141.Furthermore,both ML141 and STIM1 knockdown inhibited the upregulation of EndMT-related transcription factors Snail and Twist(P<0.05).CON-CLUSION:Cdc42 may participate in EndMT in PH by regulating store-operated calcium channels in pulmonary microvas-cular endothelial cells.

Acute lung injury(ALI)is a common critical illness caused by intrapulmonary or extra-pulmonary factors,which is accompanied by ex-tremely high morbidity and mortality.Its pathogen-esis is extremely complex and difficult to treat.Src homology 2 domain-containing protein tyrosine phosphatase(Shp2),a key cellular signal transduc-tion molecule,plays a pivotal role in the pathophys-iological processes of diverse diseases.Notably,in the context of pathogen infection,Shp2 regulates the functionality of cellular immunity,lung epitheli-al cells,and vascular endothelial cells.This review article highlights the significant role of Shp2 in the onset and progression of ALI,emphasizing its regu-lation of inflammatory response,apoptosis,and ox-idative stress.Shp2 could emerge as a novel thera-peutic target for ALI,offering valuable insights for the development of innovative drug candidates to treat this debilitating condition.

Acute lung injury(ALI)is a common critical illness caused by intrapulmonary or extra-pulmonary factors,which is accompanied by ex-tremely high morbidity and mortality.Its pathogen-esis is extremely complex and difficult to treat.Src homology 2 domain-containing protein tyrosine phosphatase(Shp2),a key cellular signal transduc-tion molecule,plays a pivotal role in the pathophys-iological processes of diverse diseases.Notably,in the context of pathogen infection,Shp2 regulates the functionality of cellular immunity,lung epitheli-al cells,and vascular endothelial cells.This review article highlights the significant role of Shp2 in the onset and progression of ALI,emphasizing its regu-lation of inflammatory response,apoptosis,and ox-idative stress.Shp2 could emerge as a novel thera-peutic target for ALI,offering valuable insights for the development of innovative drug candidates to treat this debilitating condition.

Objective:To investigate the impact of the size of the liver tumor diameter on the prognosis of patients with hepatitis B-related hepatocellular carcinoma (HCC)-inducing acute-on-chronic liver failure (HBV-HCC/ACLF).Method:A retrospective cohort study was conducted. Clinical data of patients with hepatitis B-related acute-on-chronic liver failure (HBV-ACLF) diagnosed according to the Asia-Pacific Association for the Study of the Liver (APASLT) guidelines who were admitted to the Fifth Medical Center of PLA General Hospital between January 2016 and January 2021 were collected. The patients were enrolled in the HBV-HCC/ACLF group (116 cases) and the HBV-ACLF group (348 cases). General information, medical history, biochemical parameters, complications, and liver cancer status were collected. Clinical data and prognoses at 28 days and 12 months of follow-up were compared between the two groups. Factors influencing mortality in the HBV-HCC/ACLF group were analyzed to determine the prognostic significance of tumor diameter. The t test, χ 2 test, and multivariate logistic regression analysis were used to analyze factors influencing mortality. Receiver operating characteristic (ROC) curves were used to assess the sensitivity and specificity of tumor diameter for 28-day prognosis, and Kaplan-Meier curves were used for survival analysis. Result:There were statistically significant differences in the 28-day mortality rate [(55.17%, 64/116) vs. (38.51%, 134/348)] and 12-month mortality rate [(78.45%, 91/116) vs. (55.75%, 194/348)] between the HBV-HCC/ACLF group and the HBV-ACLF group ( P<0.05). The area under the ROC curve analysis for HBV-HCC/ACLF patients indicated that the tumor diameter was 0.707 (95% CI: 0.615-0.788). The survival group (52 cases) and the mortality group (64 cases) were divided into the HBV-HCC/ACLF group based on 28-day mortality. Univariate analysis showed that the levels of aspartate aminotransferase (AST), alkaline phosphatase, creatinine, alpha-fetoprotein, white blood cell count, international normalized ratio, model for end-stage liver disease score, acute kidney injury (AKI), the occurrence of infections and complications, and others were all significantly higher in the mortality group compared to the survival group ( P<0.05).The mortality group had a larger tumor diameter than the survival group ( P<0.01). The incidence of portal vein tumor thrombosis and distant liver cancer metastasis was also higher in the survival group ( P<0.01). The mortality group had a higher rate of HCC-related minimally invasive treatment within three months before ACLF diagnosis than the survival group ( P<0.01). AST levels, infection, size of tumor diameter, and minimally invasive treatment within three months before onset were independent risk factors for 28-day mortality in the HBV-HCC/ACLF group. The optimal significant value for tumor diameter affecting prognosis was 3.3 cm, with a sensitivity of 67.19% and a specificity of 73.08%. Patients with liver tumor diameters >3.3 cm had significantly lower 28-day survival rates than those with a tumor diameter ≤3.3 cm [(24.56%, 14/57) vs. (64.41%, 38/59)]. Eighty case analyses had the same findings in patients who had not previously received any therapy. Conclusion:Patients with HBV-HCC/ACLF had a high 28-day mortality rate, and the size of the tumor diameter is important in determining the 28-day prognosis.

Chronic hepatitis B（CHB）is one of the major challenges in the global public health field. As of 2022，approximately 254 million people worldwide were infected with the hepatitis B virus（HBV）. CHB is one of the main causes of liver cirrhosis and hepatocellular carcinoma（HCC）. Nucleos（t）ide analogs（NAs）and interferon therapy can delay the progression of liver fibrosis by inhibiting viral replication，but they cannot completely avoid the problem of heterogeneous treatment responses. Some patients are in a state of low-level viremia（LLV）during treatment. The persistent LLV state can induce chronic inflammation and the progression of liver fibrosis，ultimately increase the risk of HCC. In patients with poor treatment responses，the continuous active viral replication can induce immune disorders，accelerate the evolution of fibrosis to the decompensated stage of liver cirrhosis，and increase the risk of patient death. This article aims to review the definition，mechanisms，and impact on treatment outcomes of LLV and suboptimal response based on the latest research，provide a basis for optimizing antiviral therapy for CHB.

AIM:This study aims to investigate the potential mechanism of cell division cycle protein 42(Cdc42)in acute lung injury(ALI).METHODS:(1)The levels of Cdc42 and IQ motif-containing GTPase-activating protein 1(IQGAP1)in ALI were analyzed using the Gene Expression Omnibus(GEO)database.(2)The plasma samples were collected from 30 patients diagnosed with ALI and 30 healthy controls between January 2022 and December 2023.The bronchoalveolar lavage fluid(BALF)from ALI patients was also collected.Eighteen male C57BL/6 mice were ran-domly divided into control(CON)group,lipopolysaccharide(LPS)group,and LPS+ML141(Cdc42 inhibitor)group,with 6 mice in each group.After 72 h,the mice were euthanized,and the BALF was collected for analysis,including cell enumeration and protein concentration determination using the bicinchoninic acid method.Enzyme-linked immunosorbent assay was used to measure the levels of Cdc42 and inflammatory cytokines[interleukin-6(IL-6),IL-1β and tumor necro-sis factor α(TNF-α)]in human plasma and mouse BALF.Lung damage in mouse tissue sections was evaluated by HE staining.(3)Mouse pulmonary microvascular endothelial cells(PMVECs)were isolated by magnetic bead-based cell sorting and were divided into CON,LPS and LPS+ML141 groups.Vascular ring formation assay was conducted to assess the an-giogenic potential of PMVECs,and calcium ion imaging technology was employed to measure calcium ion concentrations in PMVECs.The levels of reactive oxygen species(ROS)were assessed using a ROS detection kit.Western blot was uti-lized to analyze the protein levels of Cdc42,VE-cadherin,intercellular adhesion molecule-1(ICAM-1),myosin light chain(MLC),phosphorylated MLC(p-MLC)and IQGAP1 in PMVECs.RESULTS:(1)The GEO database analysis re-vealed significant up-regulation of Cdc42 expression in ALI model(P<0.01).(2)Clinical assessments showed markedly elevated plasma levels of Cdc42 and pro-inflammatory cytokines(IL-6,IL-1β and TNF-α)in ALI patients(P<0.01),with subsequent reductions after treatment(P<0.05).Neutrophil counts in the BALF of ALI patients were significantly in-creased.In ALI animal models,cell count,protein concentration and inflammatory mediator levels in BALF,and lung tis-sue damage scores were significantly elevated(P<0.01),all of which were notably reduced after treatment with Cdc42 in-hibitor ML141(P<0.05).(3)The PMVECs in LPS group exhibited significant increases in Cdc42,ICAM-1,p-MLC,IQGAP1,ROS,and calcium ion concentrations(P<0.01),alongside significant decreases in VE-cadherin expression and angiogenic capacity(P<0.01).All parameters were significantly improved after ML141 treatment(P<0.05).CON-CLUSION:The Cdc42 may influence IQGAP1 by modulating calcium levels in PMVECs,playing a critical role in pulmo-nary vascular barrier injury during ALI.

AIM:This study aims to investigate the potential mechanism of cell division cycle protein 42(Cdc42)in acute lung injury(ALI).METHODS:(1)The levels of Cdc42 and IQ motif-containing GTPase-activating protein 1(IQGAP1)in ALI were analyzed using the Gene Expression Omnibus(GEO)database.(2)The plasma samples were collected from 30 patients diagnosed with ALI and 30 healthy controls between January 2022 and December 2023.The bronchoalveolar lavage fluid(BALF)from ALI patients was also collected.Eighteen male C57BL/6 mice were ran-domly divided into control(CON)group,lipopolysaccharide(LPS)group,and LPS+ML141(Cdc42 inhibitor)group,with 6 mice in each group.After 72 h,the mice were euthanized,and the BALF was collected for analysis,including cell enumeration and protein concentration determination using the bicinchoninic acid method.Enzyme-linked immunosorbent assay was used to measure the levels of Cdc42 and inflammatory cytokines[interleukin-6(IL-6),IL-1β and tumor necro-sis factor α(TNF-α)]in human plasma and mouse BALF.Lung damage in mouse tissue sections was evaluated by HE staining.(3)Mouse pulmonary microvascular endothelial cells(PMVECs)were isolated by magnetic bead-based cell sorting and were divided into CON,LPS and LPS+ML141 groups.Vascular ring formation assay was conducted to assess the an-giogenic potential of PMVECs,and calcium ion imaging technology was employed to measure calcium ion concentrations in PMVECs.The levels of reactive oxygen species(ROS)were assessed using a ROS detection kit.Western blot was uti-lized to analyze the protein levels of Cdc42,VE-cadherin,intercellular adhesion molecule-1(ICAM-1),myosin light chain(MLC),phosphorylated MLC(p-MLC)and IQGAP1 in PMVECs.RESULTS:(1)The GEO database analysis re-vealed significant up-regulation of Cdc42 expression in ALI model(P<0.01).(2)Clinical assessments showed markedly elevated plasma levels of Cdc42 and pro-inflammatory cytokines(IL-6,IL-1β and TNF-α)in ALI patients(P<0.01),with subsequent reductions after treatment(P<0.05).Neutrophil counts in the BALF of ALI patients were significantly in-creased.In ALI animal models,cell count,protein concentration and inflammatory mediator levels in BALF,and lung tis-sue damage scores were significantly elevated(P<0.01),all of which were notably reduced after treatment with Cdc42 in-hibitor ML141(P<0.05).(3)The PMVECs in LPS group exhibited significant increases in Cdc42,ICAM-1,p-MLC,IQGAP1,ROS,and calcium ion concentrations(P<0.01),alongside significant decreases in VE-cadherin expression and angiogenic capacity(P<0.01).All parameters were significantly improved after ML141 treatment(P<0.05).CON-CLUSION:The Cdc42 may influence IQGAP1 by modulating calcium levels in PMVECs,playing a critical role in pulmo-nary vascular barrier injury during ALI.

Chronic hepatitis B（CHB）is one of the major challenges in the global public health field. As of 2022，approximately 254 million people worldwide were infected with the hepatitis B virus（HBV）. CHB is one of the main causes of liver cirrhosis and hepatocellular carcinoma（HCC）. Nucleos（t）ide analogs（NAs）and interferon therapy can delay the progression of liver fibrosis by inhibiting viral replication，but they cannot completely avoid the problem of heterogeneous treatment responses. Some patients are in a state of low-level viremia（LLV）during treatment. The persistent LLV state can induce chronic inflammation and the progression of liver fibrosis，ultimately increase the risk of HCC. In patients with poor treatment responses，the continuous active viral replication can induce immune disorders，accelerate the evolution of fibrosis to the decompensated stage of liver cirrhosis，and increase the risk of patient death. This article aims to review the definition，mechanisms，and impact on treatment outcomes of LLV and suboptimal response based on the latest research，provide a basis for optimizing antiviral therapy for CHB.

Objective:To investigate the impact of the size of the liver tumor diameter on the prognosis of patients with hepatitis B-related hepatocellular carcinoma (HCC)-inducing acute-on-chronic liver failure (HBV-HCC/ACLF).Method:A retrospective cohort study was conducted. Clinical data of patients with hepatitis B-related acute-on-chronic liver failure (HBV-ACLF) diagnosed according to the Asia-Pacific Association for the Study of the Liver (APASLT) guidelines who were admitted to the Fifth Medical Center of PLA General Hospital between January 2016 and January 2021 were collected. The patients were enrolled in the HBV-HCC/ACLF group (116 cases) and the HBV-ACLF group (348 cases). General information, medical history, biochemical parameters, complications, and liver cancer status were collected. Clinical data and prognoses at 28 days and 12 months of follow-up were compared between the two groups. Factors influencing mortality in the HBV-HCC/ACLF group were analyzed to determine the prognostic significance of tumor diameter. The t test, χ 2 test, and multivariate logistic regression analysis were used to analyze factors influencing mortality. Receiver operating characteristic (ROC) curves were used to assess the sensitivity and specificity of tumor diameter for 28-day prognosis, and Kaplan-Meier curves were used for survival analysis. Result:There were statistically significant differences in the 28-day mortality rate [(55.17%, 64/116) vs. (38.51%, 134/348)] and 12-month mortality rate [(78.45%, 91/116) vs. (55.75%, 194/348)] between the HBV-HCC/ACLF group and the HBV-ACLF group ( P<0.05). The area under the ROC curve analysis for HBV-HCC/ACLF patients indicated that the tumor diameter was 0.707 (95% CI: 0.615-0.788). The survival group (52 cases) and the mortality group (64 cases) were divided into the HBV-HCC/ACLF group based on 28-day mortality. Univariate analysis showed that the levels of aspartate aminotransferase (AST), alkaline phosphatase, creatinine, alpha-fetoprotein, white blood cell count, international normalized ratio, model for end-stage liver disease score, acute kidney injury (AKI), the occurrence of infections and complications, and others were all significantly higher in the mortality group compared to the survival group ( P<0.05).The mortality group had a larger tumor diameter than the survival group ( P<0.01). The incidence of portal vein tumor thrombosis and distant liver cancer metastasis was also higher in the survival group ( P<0.01). The mortality group had a higher rate of HCC-related minimally invasive treatment within three months before ACLF diagnosis than the survival group ( P<0.01). AST levels, infection, size of tumor diameter, and minimally invasive treatment within three months before onset were independent risk factors for 28-day mortality in the HBV-HCC/ACLF group. The optimal significant value for tumor diameter affecting prognosis was 3.3 cm, with a sensitivity of 67.19% and a specificity of 73.08%. Patients with liver tumor diameters >3.3 cm had significantly lower 28-day survival rates than those with a tumor diameter ≤3.3 cm [(24.56%, 14/57) vs. (64.41%, 38/59)]. Eighty case analyses had the same findings in patients who had not previously received any therapy. Conclusion:Patients with HBV-HCC/ACLF had a high 28-day mortality rate, and the size of the tumor diameter is important in determining the 28-day prognosis.