BACKGROUND Cancerous inhibitor of protein phosphatase 2A(CIP2A)is a newly discovered oncogene.It is an active cell proliferation regulatory factor that inhibits tumor apoptosis in gastric cancer(GC)cells.CIP2A is func...BACKGROUND Cancerous inhibitor of protein phosphatase 2A(CIP2A)is a newly discovered oncogene.It is an active cell proliferation regulatory factor that inhibits tumor apoptosis in gastric cancer(GC)cells.CIP2A is functionally related to chemoresistance in various types of tumors according to recent studies.The underlying mechanism,however,is unknown.Further,the primary treatment regimen for GC is oxaliplatin-based chemotherapy.Nonetheless,it often fails due to chemoresistance of GC cells to oxaliplatin.AIM The goal of this study was to examine CIP2A expression and its association with oxaliplatin resistance in human GC cells.METHODS Immunohistochemistry was used to examine CIP2A expression in GC tissues and adjacent normal tissues.CIP2A expression in GC cell lines was reduced using small interfering RNA.After confirming the silencing efficiency,3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide tetrazolium and flow cytometry assays were used to evaluate cell proliferation and apoptosis caused by oxaliplatin treatment.Further,the key genes and protein changes were verified using realtime quantitative reverse transcription PCR and Western blotting,respectively,before and after intervention.For bioinformatics analysis,we used the R software and Bioconductor project.For statistical analysis,we used GraphPad Prism 6.0 and the Statistical Package for the Social Sciences software version 20.0(IBM,Armonk,United States).RESULTS A high level of CIP2A expression was associated with tumor size,T stage,lymph node metastasis,Tumor Node Metastasis stage,and a poor prognosis.Further,CIP2A expression was higher in GC cells than in normal human gastric epithelial cells.Using small interfering RNA against CIP2A,we discovered that CIP2A knockdown inhibited cell proliferation and significantly increased GC cell sensitivity to oxaliplatin.Moreover,CIP2A knockdown enhanced oxaliplatin-induced apoptosis in GC cells.Hence,high CIP2A levels in GC may be a factor in chemoresistance to oxaliplatin.In human GC cells,CIP2A regulated protein kinase B phosphorylation,and chemical inhibition of the protein kinase B signaling pathway was significantly associated with increased sensitivity to oxaliplatin.Therefore,the protein kinase B signaling pathway was correlated with CIP2Aenhanced chemoresistance of human GC cells to oxaliplatin.CONCLUSION CIP2A expression could be a novel therapeutic strategy for chemoresistance in GC.展开更多
Genome wide association studies have associated single nucleotide polymorphisms within the gene locus encoding protein tyrosine phosphatase non-receptor type 2(PTPN2) with the onset of inflammatory bowel disease(IBD) ...Genome wide association studies have associated single nucleotide polymorphisms within the gene locus encoding protein tyrosine phosphatase non-receptor type 2(PTPN2) with the onset of inflammatory bowel disease(IBD) and other inflammatory disorders. Expression of PTPN2 is enhanced in actively inflamed intestinal tissue featuring a marked up-regulation in intestinal epithelial cells. PTPN2 deficient mice suffer from severe intestinal and systemic inflammation and display aberrant innate and adaptive immune responses. In particular, PTPN2 is involved in the regulation of inflammatory signalling cascades, and critical for protecting intestinal epithelial barrier function, regulating innate and adaptive immune responses, and finally for maintaining intestinal homeostasis. On one hand, dysfunction of PTPN2 has drastic effects on innate host defence mechanisms, including increased secretion of pro-inflammatory cytokines, limited autophagosome formation in response to invading pathogens, and disruption of the intestinal epithelial barrier. On the other hand, PTPN2 function is crucial for controlling adaptive immune functions, by regulating T cell proliferation and differentiation as well as maintaining T cell tolerance. In this way, dysfunction of PTPN2 contributes to the manifestation of IBD. The aim of this review is to present an overview of recent findings on the role of PTPN2 in intestinal homeostasis and the impact of dysfunctional PTPN2 on intestinal inflammation.展开更多
Protein phosphatase 2A(PP2A)is a major serine/threonine phosphatase which participates in the regulation of multiple cellular processes.As a confirmed tumor suppressor,PP2A activity is downregulated in tumors and its ...Protein phosphatase 2A(PP2A)is a major serine/threonine phosphatase which participates in the regulation of multiple cellular processes.As a confirmed tumor suppressor,PP2A activity is downregulated in tumors and its re-activation can induce apoptosis of cancer cells.In the brains of Alzheimer's disease(AD)patients,decreased PP2A activity also plays a key role in promoting tau hyperphosphorylation and A0 generation.In this review,we discussed compounds aiming at modulating PP2A activity in the treatment of cancer or AD.The upstream factors that inactivate PP2A in diseases have not been fully elucidated and further studies are needed.It will help for the refinement and development of novel and clinically tractable PP2A-targeted compounds or therapies for the treatment of tumor and AD.展开更多
BACKGROUND Protein phosphatase 2 regulatory subunit B''alpha(PPP2R3A)gene has been reported in other tumors,but the influence of PPP2R3A gene expression on the occurrence,development,and prognosis of hepatocel...BACKGROUND Protein phosphatase 2 regulatory subunit B''alpha(PPP2R3A)gene has been reported in other tumors,but the influence of PPP2R3A gene expression on the occurrence,development,and prognosis of hepatocellular carcinoma(HCC)remains unclear.AIM To investigate whether the PPP2R3A gene could be used to predict tumor recurrence and survival of HCC patients after liver transplantation(LT).METHODS Diseased liver tissues of HCC patients after LT were collected as well as their clinical data and follow-up information.The immunohistochemical method was used to detect the expression of PPP2R3A protein in the tissues of 108 patients with primary liver cancer.Theχ2 test was used to analyze the relationship between PPP2R3A protein expression levels and the clinicopathological features of tumors.The Kaplan-Meier method was used to analyze overall postoperative survival.The COX proportional hazard model was used to analyze adverse prognostic factors.RESULTS Immunohistochemistry showed that the PPP2R3A protein was mainly expressed in the cytoplasm of HCC cells.Compared to corresponding peritumoral tissues,expression was higher in HCC tissues(P≤0.001).Correlation analysis showed that high PPP2R3A expression was correlated with preoperative serum alphafetoprotein(AFP)levels(P=0.003),tumor-node-metastasis-t stage(P≤0.001),and envelope invasion(P=0.001).Univariate analysis showed that overall survival(P≤0.001)and recurrence-free survival(P=0.025)of patients with high PPP2R3A expression(≥4 points)were poor compared to those with low expression(<4 points).The overall survival rates or recurrence-free survival rates at 1,2,and 3 years with high PPP2R3A expression were 73%,38%,and 23%or 31%,23%,and 23%,respectively.Multivariate analysis showed that high PPP2R3A expression(hazard ratio=2.900,95%confidence interval:1.411–5.960,P=0.004)was an independent survival risk factor of HCC patients after LT,and it was also an independent predictor of postoperative tumor recurrence.This study also showed in patients with AFP≥400 ng/mL,the overall survival(P≤0.001)and recurrencefree survival(P=0.023)of those with high PPP2R3A expression were significantly worse compared to those with low PPP2R3A expression.When PPP2R3A expression was low,the overall survival rate(P=0.461)or recurrence-free survival rate(P=0.072)after LT in patients with AFP<400 ng/mL and≥400 ng/mL was not significantly difference.The 1,2,and 3 year survival rate of patients with low PPP2R3A expression and AFP<400 ng/mL were 98%,80%,and 69%,respectively,while patients who met Hangzhou criteria had a posttransplant 1,2,and 3 years overall survival rate of 89%,66%,and 55%,respectively.CONCLUSION High expression of PPP2R3A might be a potential marker for predicting poor prognosis of HCC after LT.Combined with serum AFP levels,PPP2R3A might enhance the accuracy of predicting HCC outcome in patients after LT and supplement the efficacy of the Hangzhou criteria.展开更多
The Ikaros gene encodes a zinc finger,DNA-binding protein that regulates gene transcription and chromatin remodeling.Ikaros is a master regulator of hematopoiesis and an established tumor suppressor.Moderate alteratio...The Ikaros gene encodes a zinc finger,DNA-binding protein that regulates gene transcription and chromatin remodeling.Ikaros is a master regulator of hematopoiesis and an established tumor suppressor.Moderate alteration of Ikaros activity (e.g.haploinsufficiency) appears to be sufficient to promote malignant transformation in human hematopoietic cells.This raises questions about the mechanisms that normally regulate Ikaros function and the potential of these mechanisms to contribute to the development of leukemia.The focus of this review is the regulation of Ikaros function by phosphorylation/dephosphorylation.Site-specific phosphorylation of Ikaros by casein kinase 2 (CK2) controls Ikaros DNA-binding ability and subcellular localization.As a consequence,the ability of Ikaros to regulate cell cycle progression,chromatin remodeling,target gene expression,and thymocyte differentiation are controlled by CK2.In addition,hyperphosphorylation of Ikaros by CK2 leads to decreased Ikaros levels due to ubiquitinmediated degradation.Dephosphorylation of Ikaros by protein phosphatase 1 (PP1) acts in opposition to CK2 to increase Ikaros stability and restore Ikaros DNA binding ability and pericentromeric localization.Thus,the CK2 and PP1 pathways act in concert to regulate Ikaros activity in hematopoiesis and as a tumor suppressor.This highlights the importance of these signal transduction pathways as potential mediators of leukemogenesis via their role in regulating the activities of Ikaros.展开更多
Reducing the secondary inflammatory response, which is partly mediated by microglia, is a key focus in the treatment of spinal cord injury. Src homology 2-containing protein tyrosine phosphatase 2(SHP2), encoded by PT...Reducing the secondary inflammatory response, which is partly mediated by microglia, is a key focus in the treatment of spinal cord injury. Src homology 2-containing protein tyrosine phosphatase 2(SHP2), encoded by PTPN11, is widely expressed in the human body and plays a role in inflammation through various mechanisms. Therefore, SHP2 is considered a potential target for the treatment of inflammation-related diseases. However, its role in secondary inflammation after spinal cord injury remains unclear. In this study, SHP2 was found to be abundantly expressed in microglia at the site of spinal cord injury. Inhibition of SHP2 expression using siRNA and SHP2 inhibitors attenuated the microglial inflammatory response in an in vitro lipopolysaccharide-induced model of inflammation. Notably, after treatment with SHP2 inhibitors, mice with spinal cord injury exhibited significantly improved hind limb locomotor function and reduced residual urine volume in the bladder. Subsequent in vitro experiments showed that, in microglia stimulated with lipopolysaccharide, inhibiting SHP2 expression promoted M2 polarization and inhibited M1 polarization. Finally, a co-culture experiment was conducted to assess the effect of microglia treated with SHP2 inhibitors on neuronal cells. The results demonstrated that inflammatory factors produced by microglia promoted neuronal apoptosis, while inhibiting SHP2 expression mitigated these effects. Collectively, our findings suggest that SHP2 enhances secondary inflammation and neuronal damage subsequent to spinal cord injury by modulating microglial phenotype. Therefore, inhibiting SHP2 alleviates the inflammatory response in mice with spinal cord injury and promotes functional recovery postinjury.展开更多
Ischemic stroke can cause blood-brain barrier(BBB)injury,which worsens brain damage induced by stroke.Abnormal expression of tight junction proteins in endothelial cells(ECs)can increase intracellular space and BBB le...Ischemic stroke can cause blood-brain barrier(BBB)injury,which worsens brain damage induced by stroke.Abnormal expression of tight junction proteins in endothelial cells(ECs)can increase intracellular space and BBB leakage.Selective inhibition of mitogen-activated protein kinase,the negative regulatory substrate of mitogen-activated protein kinase phosphatase(MKP)-1,improves tight junction protein function in ECs,and genetic deletion of MKP-1 aggravates ischemic brain injury.However,whether the latter affects BBB integrity,and the cell type-specific mechanism underlying this process,remain unclear.In this study,we established an adult male mouse model of ischemic stroke by occluding the middle cerebral artery for 60 minutes and overexpressed MKP-1 in ECs on the injured side via lentiviral transfection before stroke.We found that overexpression of MKP-1 in ECs reduced infarct volume,reduced the level of inflammatory factors interleukin-1β,interleukin-6,and chemokine C-C motif ligand-2,inhibited vascular injury,and promoted the recovery of sensorimotor and memory/cognitive function.Overexpression of MKP-1 in ECs also inhibited the activation of cerebral ischemia-induced extracellular signal-regulated kinase(ERK)1/2 and the downregulation of occludin expression.Finally,to investigate the mechanism by which MKP-1 exerted these functions in ECs,we established an ischemic stroke model in vitro by depriving the primary endothelial cell of oxygen and glucose,and pharmacologically inhibited the activity of MKP-1 and ERK1/2.Our findings suggest that MKP-1 inhibition aggravates oxygen and glucose deprivation-induced cell death,cell monolayer leakage,and downregulation of occludin expression,and that inhibiting ERK1/2 can reverse these effects.In addition,co-inhibition of MKP-1 and ERK1/2 exhibited similar effects to inhibition of ERK1/2.These findings suggest that overexpression of MKP-1 in ECs can prevent ischemia-induced occludin downregulation and cell death via deactivating ERK1/2,thereby protecting the integrity of BBB,alleviating brain injury,and improving post-stroke prognosis.展开更多
AIM:To explore the alteration of tyrosine phosphatase SHP-2 protein expression in gastric cancer and to assess its prognostic values.METHODS:Three hundred and five consecutive cases of gastric cancer were enrolled int...AIM:To explore the alteration of tyrosine phosphatase SHP-2 protein expression in gastric cancer and to assess its prognostic values.METHODS:Three hundred and five consecutive cases of gastric cancer were enrolled into this study.SHP-2 expression was carried out in 305 gastric cancer specimens,of which 83 were paired adjacent normal gastric mucus samples,using a tissue microarray immunohistochemical method.Correlations were analyzed between expression levels of SHP-2 protein and tumor parameters or clinical outcomes.Serum anti-Helicobacter pylori(H.pylori) immunoglobulin G was detected with enzyme-linked immunosorbent assay.Cox proportional hazards model was used to evaluate prognostic values by compassion of the expression levels of SHP-2 and disease-specific survivals in patients.RESULTS:SHP-2 staining was found diffuse mainly in the cytoplasm and the weak staining was also observed in the nucleus in gastric mucosa cells.Thirty-two point five percent of normal epithelial specimen and 62.6% of gastric cancer specimen were identified to stain with SHP-2 antibody positively(P < 0.001).Though SHP-2 staining intensities were stronger in the H.pylori(+) group than in the H.pylori(-) group,no statistically significant difference was found in the expression levels of SHP-2 between H.pylori(+) and H.pylori(-) gastric cancer(P = 0.40).The SHP-2 expression in gastric cancer was not significantly associated with cancer stages,lymph node metastases,and distant metastasis of the tumors(P = 0.34,P = 0.17,P = 0.52).Multivariate analysis demonstrated no correlation between SHP-2 expression and disease-free survival(P = 0.86).CONCLUSION:Increased expression of SHP-2 protein in gastric cancer specimen suggesting the aberrant upregulation of SHP-2 protein might play an important role in the gastric carcinogenesis.展开更多
基金Supported by This work was supported by the Natural Science Foundation of Gansu Province,China,No.17JR5RA272 and No.22JR5RA923the Research Fund Project of The First Hospital of Lanzhou University,No.ldyyyn2021-120,No.ldyyyn2020-98 and No.ldyyyn2021-30.
文摘BACKGROUND Cancerous inhibitor of protein phosphatase 2A(CIP2A)is a newly discovered oncogene.It is an active cell proliferation regulatory factor that inhibits tumor apoptosis in gastric cancer(GC)cells.CIP2A is functionally related to chemoresistance in various types of tumors according to recent studies.The underlying mechanism,however,is unknown.Further,the primary treatment regimen for GC is oxaliplatin-based chemotherapy.Nonetheless,it often fails due to chemoresistance of GC cells to oxaliplatin.AIM The goal of this study was to examine CIP2A expression and its association with oxaliplatin resistance in human GC cells.METHODS Immunohistochemistry was used to examine CIP2A expression in GC tissues and adjacent normal tissues.CIP2A expression in GC cell lines was reduced using small interfering RNA.After confirming the silencing efficiency,3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide tetrazolium and flow cytometry assays were used to evaluate cell proliferation and apoptosis caused by oxaliplatin treatment.Further,the key genes and protein changes were verified using realtime quantitative reverse transcription PCR and Western blotting,respectively,before and after intervention.For bioinformatics analysis,we used the R software and Bioconductor project.For statistical analysis,we used GraphPad Prism 6.0 and the Statistical Package for the Social Sciences software version 20.0(IBM,Armonk,United States).RESULTS A high level of CIP2A expression was associated with tumor size,T stage,lymph node metastasis,Tumor Node Metastasis stage,and a poor prognosis.Further,CIP2A expression was higher in GC cells than in normal human gastric epithelial cells.Using small interfering RNA against CIP2A,we discovered that CIP2A knockdown inhibited cell proliferation and significantly increased GC cell sensitivity to oxaliplatin.Moreover,CIP2A knockdown enhanced oxaliplatin-induced apoptosis in GC cells.Hence,high CIP2A levels in GC may be a factor in chemoresistance to oxaliplatin.In human GC cells,CIP2A regulated protein kinase B phosphorylation,and chemical inhibition of the protein kinase B signaling pathway was significantly associated with increased sensitivity to oxaliplatin.Therefore,the protein kinase B signaling pathway was correlated with CIP2Aenhanced chemoresistance of human GC cells to oxaliplatin.CONCLUSION CIP2A expression could be a novel therapeutic strategy for chemoresistance in GC.
基金Supported by Grants from the Swiss National Science Foundation(SNF)to MSGrant No.314730-146204 and No.CRSII3_154488/1(to Rogler G)+2 种基金Grant No.310030-120312the Swiss IBD CohortGrant No.3347CO-108792
文摘Genome wide association studies have associated single nucleotide polymorphisms within the gene locus encoding protein tyrosine phosphatase non-receptor type 2(PTPN2) with the onset of inflammatory bowel disease(IBD) and other inflammatory disorders. Expression of PTPN2 is enhanced in actively inflamed intestinal tissue featuring a marked up-regulation in intestinal epithelial cells. PTPN2 deficient mice suffer from severe intestinal and systemic inflammation and display aberrant innate and adaptive immune responses. In particular, PTPN2 is involved in the regulation of inflammatory signalling cascades, and critical for protecting intestinal epithelial barrier function, regulating innate and adaptive immune responses, and finally for maintaining intestinal homeostasis. On one hand, dysfunction of PTPN2 has drastic effects on innate host defence mechanisms, including increased secretion of pro-inflammatory cytokines, limited autophagosome formation in response to invading pathogens, and disruption of the intestinal epithelial barrier. On the other hand, PTPN2 function is crucial for controlling adaptive immune functions, by regulating T cell proliferation and differentiation as well as maintaining T cell tolerance. In this way, dysfunction of PTPN2 contributes to the manifestation of IBD. The aim of this review is to present an overview of recent findings on the role of PTPN2 in intestinal homeostasis and the impact of dysfunctional PTPN2 on intestinal inflammation.
基金grants from National Natural Science Foundation of China(No.31970964 and No.31771189)Natural Science Foundation of Hubei Province,China(No.2017CFA065)Wuhan Health and Family Planning Commission(No.WX18C17).
文摘Protein phosphatase 2A(PP2A)is a major serine/threonine phosphatase which participates in the regulation of multiple cellular processes.As a confirmed tumor suppressor,PP2A activity is downregulated in tumors and its re-activation can induce apoptosis of cancer cells.In the brains of Alzheimer's disease(AD)patients,decreased PP2A activity also plays a key role in promoting tau hyperphosphorylation and A0 generation.In this review,we discussed compounds aiming at modulating PP2A activity in the treatment of cancer or AD.The upstream factors that inactivate PP2A in diseases have not been fully elucidated and further studies are needed.It will help for the refinement and development of novel and clinically tractable PP2A-targeted compounds or therapies for the treatment of tumor and AD.
基金National Natural Science Foundation of China,No.81372595.
文摘BACKGROUND Protein phosphatase 2 regulatory subunit B''alpha(PPP2R3A)gene has been reported in other tumors,but the influence of PPP2R3A gene expression on the occurrence,development,and prognosis of hepatocellular carcinoma(HCC)remains unclear.AIM To investigate whether the PPP2R3A gene could be used to predict tumor recurrence and survival of HCC patients after liver transplantation(LT).METHODS Diseased liver tissues of HCC patients after LT were collected as well as their clinical data and follow-up information.The immunohistochemical method was used to detect the expression of PPP2R3A protein in the tissues of 108 patients with primary liver cancer.Theχ2 test was used to analyze the relationship between PPP2R3A protein expression levels and the clinicopathological features of tumors.The Kaplan-Meier method was used to analyze overall postoperative survival.The COX proportional hazard model was used to analyze adverse prognostic factors.RESULTS Immunohistochemistry showed that the PPP2R3A protein was mainly expressed in the cytoplasm of HCC cells.Compared to corresponding peritumoral tissues,expression was higher in HCC tissues(P≤0.001).Correlation analysis showed that high PPP2R3A expression was correlated with preoperative serum alphafetoprotein(AFP)levels(P=0.003),tumor-node-metastasis-t stage(P≤0.001),and envelope invasion(P=0.001).Univariate analysis showed that overall survival(P≤0.001)and recurrence-free survival(P=0.025)of patients with high PPP2R3A expression(≥4 points)were poor compared to those with low expression(<4 points).The overall survival rates or recurrence-free survival rates at 1,2,and 3 years with high PPP2R3A expression were 73%,38%,and 23%or 31%,23%,and 23%,respectively.Multivariate analysis showed that high PPP2R3A expression(hazard ratio=2.900,95%confidence interval:1.411–5.960,P=0.004)was an independent survival risk factor of HCC patients after LT,and it was also an independent predictor of postoperative tumor recurrence.This study also showed in patients with AFP≥400 ng/mL,the overall survival(P≤0.001)and recurrencefree survival(P=0.023)of those with high PPP2R3A expression were significantly worse compared to those with low PPP2R3A expression.When PPP2R3A expression was low,the overall survival rate(P=0.461)or recurrence-free survival rate(P=0.072)after LT in patients with AFP<400 ng/mL and≥400 ng/mL was not significantly difference.The 1,2,and 3 year survival rate of patients with low PPP2R3A expression and AFP<400 ng/mL were 98%,80%,and 69%,respectively,while patients who met Hangzhou criteria had a posttransplant 1,2,and 3 years overall survival rate of 89%,66%,and 55%,respectively.CONCLUSION High expression of PPP2R3A might be a potential marker for predicting poor prognosis of HCC after LT.Combined with serum AFP levels,PPP2R3A might enhance the accuracy of predicting HCC outcome in patients after LT and supplement the efficacy of the Hangzhou criteria.
基金Supported by (in part) An NIH R01 HL095120 grant,a St.Baldrick’s Foundation Career Development Award,the Four Diamonds Fund of the Pennsylvania State University College of Medicine,and the John Wawrynovic Leukemia Research Scholar Endowment (SD)
文摘The Ikaros gene encodes a zinc finger,DNA-binding protein that regulates gene transcription and chromatin remodeling.Ikaros is a master regulator of hematopoiesis and an established tumor suppressor.Moderate alteration of Ikaros activity (e.g.haploinsufficiency) appears to be sufficient to promote malignant transformation in human hematopoietic cells.This raises questions about the mechanisms that normally regulate Ikaros function and the potential of these mechanisms to contribute to the development of leukemia.The focus of this review is the regulation of Ikaros function by phosphorylation/dephosphorylation.Site-specific phosphorylation of Ikaros by casein kinase 2 (CK2) controls Ikaros DNA-binding ability and subcellular localization.As a consequence,the ability of Ikaros to regulate cell cycle progression,chromatin remodeling,target gene expression,and thymocyte differentiation are controlled by CK2.In addition,hyperphosphorylation of Ikaros by CK2 leads to decreased Ikaros levels due to ubiquitinmediated degradation.Dephosphorylation of Ikaros by protein phosphatase 1 (PP1) acts in opposition to CK2 to increase Ikaros stability and restore Ikaros DNA binding ability and pericentromeric localization.Thus,the CK2 and PP1 pathways act in concert to regulate Ikaros activity in hematopoiesis and as a tumor suppressor.This highlights the importance of these signal transduction pathways as potential mediators of leukemogenesis via their role in regulating the activities of Ikaros.
基金supported by the Natural Science Research Project of Anhui Province University, No.2023AH040394 (to TY)Hefei Comprehensive National Science Center Leading Medicine and Frontier Technology Research Institute Project, No.2023IHM01073 (to TY)the Natural Science Foundation of Anhui Province, Nos.2308085QH258 (to JW), 2008085MH246 (to TY)。
文摘Reducing the secondary inflammatory response, which is partly mediated by microglia, is a key focus in the treatment of spinal cord injury. Src homology 2-containing protein tyrosine phosphatase 2(SHP2), encoded by PTPN11, is widely expressed in the human body and plays a role in inflammation through various mechanisms. Therefore, SHP2 is considered a potential target for the treatment of inflammation-related diseases. However, its role in secondary inflammation after spinal cord injury remains unclear. In this study, SHP2 was found to be abundantly expressed in microglia at the site of spinal cord injury. Inhibition of SHP2 expression using siRNA and SHP2 inhibitors attenuated the microglial inflammatory response in an in vitro lipopolysaccharide-induced model of inflammation. Notably, after treatment with SHP2 inhibitors, mice with spinal cord injury exhibited significantly improved hind limb locomotor function and reduced residual urine volume in the bladder. Subsequent in vitro experiments showed that, in microglia stimulated with lipopolysaccharide, inhibiting SHP2 expression promoted M2 polarization and inhibited M1 polarization. Finally, a co-culture experiment was conducted to assess the effect of microglia treated with SHP2 inhibitors on neuronal cells. The results demonstrated that inflammatory factors produced by microglia promoted neuronal apoptosis, while inhibiting SHP2 expression mitigated these effects. Collectively, our findings suggest that SHP2 enhances secondary inflammation and neuronal damage subsequent to spinal cord injury by modulating microglial phenotype. Therefore, inhibiting SHP2 alleviates the inflammatory response in mice with spinal cord injury and promotes functional recovery postinjury.
基金supported by Research Start-up Funding of Shenzhen Traditional Chinese Medicine Hospital,No.2021-07(to FB)Sanming Project of Medicine in Shenzhen,No.SZZYSM 202111011(to XDQ and FB)+1 种基金Key Discipline Established by Zhejiang Province,Jiaxing City Jointly-Pain Medicine,No.2019-ss-ttyx(to LSX)Jiaxing Key Laboratory of Neurology and Pain Medicine,No.[2014]81(to LSX)。
文摘Ischemic stroke can cause blood-brain barrier(BBB)injury,which worsens brain damage induced by stroke.Abnormal expression of tight junction proteins in endothelial cells(ECs)can increase intracellular space and BBB leakage.Selective inhibition of mitogen-activated protein kinase,the negative regulatory substrate of mitogen-activated protein kinase phosphatase(MKP)-1,improves tight junction protein function in ECs,and genetic deletion of MKP-1 aggravates ischemic brain injury.However,whether the latter affects BBB integrity,and the cell type-specific mechanism underlying this process,remain unclear.In this study,we established an adult male mouse model of ischemic stroke by occluding the middle cerebral artery for 60 minutes and overexpressed MKP-1 in ECs on the injured side via lentiviral transfection before stroke.We found that overexpression of MKP-1 in ECs reduced infarct volume,reduced the level of inflammatory factors interleukin-1β,interleukin-6,and chemokine C-C motif ligand-2,inhibited vascular injury,and promoted the recovery of sensorimotor and memory/cognitive function.Overexpression of MKP-1 in ECs also inhibited the activation of cerebral ischemia-induced extracellular signal-regulated kinase(ERK)1/2 and the downregulation of occludin expression.Finally,to investigate the mechanism by which MKP-1 exerted these functions in ECs,we established an ischemic stroke model in vitro by depriving the primary endothelial cell of oxygen and glucose,and pharmacologically inhibited the activity of MKP-1 and ERK1/2.Our findings suggest that MKP-1 inhibition aggravates oxygen and glucose deprivation-induced cell death,cell monolayer leakage,and downregulation of occludin expression,and that inhibiting ERK1/2 can reverse these effects.In addition,co-inhibition of MKP-1 and ERK1/2 exhibited similar effects to inhibition of ERK1/2.These findings suggest that overexpression of MKP-1 in ECs can prevent ischemia-induced occludin downregulation and cell death via deactivating ERK1/2,thereby protecting the integrity of BBB,alleviating brain injury,and improving post-stroke prognosis.
基金Supported by National Natural Science Foundation of China,No. 81072369Natural Science Foundation of Jilin Province,China,No. 200905131
文摘AIM:To explore the alteration of tyrosine phosphatase SHP-2 protein expression in gastric cancer and to assess its prognostic values.METHODS:Three hundred and five consecutive cases of gastric cancer were enrolled into this study.SHP-2 expression was carried out in 305 gastric cancer specimens,of which 83 were paired adjacent normal gastric mucus samples,using a tissue microarray immunohistochemical method.Correlations were analyzed between expression levels of SHP-2 protein and tumor parameters or clinical outcomes.Serum anti-Helicobacter pylori(H.pylori) immunoglobulin G was detected with enzyme-linked immunosorbent assay.Cox proportional hazards model was used to evaluate prognostic values by compassion of the expression levels of SHP-2 and disease-specific survivals in patients.RESULTS:SHP-2 staining was found diffuse mainly in the cytoplasm and the weak staining was also observed in the nucleus in gastric mucosa cells.Thirty-two point five percent of normal epithelial specimen and 62.6% of gastric cancer specimen were identified to stain with SHP-2 antibody positively(P < 0.001).Though SHP-2 staining intensities were stronger in the H.pylori(+) group than in the H.pylori(-) group,no statistically significant difference was found in the expression levels of SHP-2 between H.pylori(+) and H.pylori(-) gastric cancer(P = 0.40).The SHP-2 expression in gastric cancer was not significantly associated with cancer stages,lymph node metastases,and distant metastasis of the tumors(P = 0.34,P = 0.17,P = 0.52).Multivariate analysis demonstrated no correlation between SHP-2 expression and disease-free survival(P = 0.86).CONCLUSION:Increased expression of SHP-2 protein in gastric cancer specimen suggesting the aberrant upregulation of SHP-2 protein might play an important role in the gastric carcinogenesis.
