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
The mitogen-activated protein kinase(MAPK) interacting protein kinases 1 and 2(Mnk1 and Mnk2) play important roles in controlling signals involved in mRNA translation. In addition to the MAPKs(p38 or Erk), multiple st...The mitogen-activated protein kinase(MAPK) interacting protein kinases 1 and 2(Mnk1 and Mnk2) play important roles in controlling signals involved in mRNA translation. In addition to the MAPKs(p38 or Erk), multiple studies suggest that the Mnk kinases can be regulated by other known kinases such as Pak2 and/or other unidentified kinases by phosphorylation of residues distinct from the sites phosphorylated by the MAPKs. Several studies have established multiple Mnk protein targets, including PSF, heterogenous nuclear ribonucleoprotein A1, Sprouty 2 and have lead to the identification of distinct biological functions and substrate specificity for the Mnk kinases. In this review we discuss the pathways regulating the Mnk kinases, their known substrates as well as the functional consequences of engagement of pathways controlled by Mnk kinases. These kinases play an important role in mRNA translation via their regulation of eukaryotic initiation factor 4E(eIF4E) and their functions have important implications in tumor biology as well as the regulation of drug resistance to anti-oncogenic therapies. Other studies have identified a role for the Mnk kinases in cap-independent mRNA translation, suggesting that the Mnk kinases can exert important functional effects independently of the phosphorylation of eIF4 E. The role of Mnk kinases in inflammation and inflammationinduced malignancies is also discussed.展开更多
AIM: To identify kinases involved in phenotype regulation of vascular endothelial cells(VECs): Proproliferative G-protein signaling 5(RGS5)^(high)(typeⅠ) vs anti-proliferative RGS5^(low)(typeⅡ) VECs.METHODS: Proteom...AIM: To identify kinases involved in phenotype regulation of vascular endothelial cells(VECs): Proproliferative G-protein signaling 5(RGS5)^(high)(typeⅠ) vs anti-proliferative RGS5^(low)(typeⅡ) VECs.METHODS: Proteomic kinase assays were performed to identify the crucial kinase involved in the phenotype regulation of human VECs using typeⅠ VECs, which promotes the proliferation of human vascular smooth muscle cells(VSMCs), and typeⅡ VECs, which suppress the proliferation of human VSMCs. The assays were performed using multiple pairs of typeⅠ and typeⅡ VECs to obtain the least number of candidates. The involvement of the candidate kinases was verified by evaluating the effects of their specific inhibitors on the phenotype regulation of human VECs as well as the expression levels of regulator of RGS5, which is the causative gene for the "typeⅡ to typeⅠ" phenotype conversion of human VECs. RESULTS: p38α mitogen-activated protein kinase(p38α MAPK) was the only kinase that showed distinctive activities between typeⅠ and typeⅡ VECs: p38α MAPK activities were low and high in type-Ⅰand typeⅡ VECs, respectively. We found that an enforced expression of RGS5 indeed lowered p38α MAPK activitiesin typeⅡ VECs. Furthermore, treatments with a p38α MAPK inhibitor nullified the anti-proliferative potential in typeⅡ VECs. Interestingly, MAPK inhibitor treatments enhanced the induction of RGS5 gene. Thus, there is a vicious cycle between "RGS5 induction" and "p38α MAPK inhibition", which can explain the unidirectional process in the stress-induced "typeⅡ to typeⅠ" conversions of human VECs. To understand the upstream signaling of RGS5, which is known as an inhibitory molecule against the G protein-coupled receptor(GPCR)-mediated signaling, we examined the effects of RGS5 overexpression on the signaling events from sphingosine-1-phosphate(S1P) to N-cadherin, because S1 P receptors belong to the GPCR family gene and N-cadherin, one of their downstream effectors, is reportedly involved in the regulation of VEC-VSMC interactions. We found that RGS5 specifically bound with S1P1. Moreover, N-cadherin localization at intercellular junctions in typeⅡ VECs was abolished by "RGS5 overexpression" and "p38α MAPK inhibition".CONCLUSION: p38α MAPK plays crucial roles in "type-Ⅰ vs type-Ⅱ" phenotype regulations of human VECs at the downstream of RGS5.展开更多
Transcription factors can be used to engineer plants for enhanced productivity.However,the mechanism(s)by which the C2H2-type zinc fi nger transcription factor enhances pathogen resistance in cells is not fully unders...Transcription factors can be used to engineer plants for enhanced productivity.However,the mechanism(s)by which the C2H2-type zinc fi nger transcription factor enhances pathogen resistance in cells is not fully understood.Here,Agrobacterium tumefaciens carrying the gene for Arabidopsis thaliana cysteine2/histidine2-type transcription factor 6(ZAT6)was used to engineer rice(Oryza sativa L.),cotton(Gossypium hirsutum L.),and slash pine(Pinus elliottii Engelm.)to generate transgenic cell lines.Transgenic cells were then inoculated with the pathogenic bacterium Pseudomonas syringae.Compared to the control,cell viability of transgenic cells increased 39–47%and growth rate increased 9–15%by 7 days after inoculation in rice,cotton and slash pine.Acid phosphatase activity and alkaline phosphatase activity and transcript levels of Ca 2+-dependent protein kinase genes OsCPK1,OsCPK2,OsCPK6,and OsCPK8 and mitogen-activated protein kinase genes OsMAPK1,OsMAPK2,OsMAPK3,and OsMAPK8 increased signifi cantly in transgenic rice cells by 3 day after inoculation,and extracellular pH had decreased by 10–14%by 96 min after inoculation in transgenic rice,cotton and slash pine cells.These results suggest that ZAT6 enhances P.syringae resistance in plant cells by modulating transcription of CPK and MAPK and oxidase activity.展开更多
Objective: To investigate the attenuating effect of Hydroxysafflor yellow A(HSYA) on inflammatory injury in chronic obstructive pulmonary disease(COPD). Methods: Rats were randomly assigned to 7 groups according to bo...Objective: To investigate the attenuating effect of Hydroxysafflor yellow A(HSYA) on inflammatory injury in chronic obstructive pulmonary disease(COPD). Methods: Rats were randomly assigned to 7 groups according to body weight including normal control group, HSYA blank group(76.8 mg/kg), COPD group, COPD+HSYA(30, 48, 76.8 mg/kg) groups and COPD+dexamethasone(2 mg/kg), 10 in each group. Passive cigarette smoke and intratracheal instil ation of lipopolysaccharides were used to establish a COPD model in rats. Hematoxylin and eosin staining of lung tissue sections was used, real-time polymerase chain reaction(PCR) was used to assay m RNA levels of some cytokines in lung tissues, the cytokines in bronchoalveolar lavage fluid(BALF) were measured by enzyme-linked immunosorbent assay(ELISA), Western blot analysis was used to determine phosphorylated p38 mitogen-activated protein kinase(MAPK) levels in lung tissues, and nuclear factor-κB(NF-κB) p65 protein levels in lung tissues were detected by immunohistochemistry. Results: Lung alveolar septa destruction, alveolus fusion, inflammatory cel infiltration, and bronchiole exudation were observed. These pathological changes were al eviated in the COPD+HSYA group. The m RNA expression of inflammatory factors were significantly increased in lung tissues from COPD rats(all P<0.01) and were inhibited by HSYA. Levels of inflammatory cytokines in BALF of COPD rats were significantly increased(all P<0.01) which were inhibited by HSYA(all P<0.01, 48, 76.8 mg/kg). The levels of p38 MAPK phosphorylation and p65 in lung tissues of COPD rats were significantly increased(al P<0.01) and were suppressed by HSYA(all P<0.01, 48, 76.8 mg/kg). Conclusions: HSYA could alleviate inflammatory cell infiltration and other pathological changes in the lungs of COPD rats. HSYA could inhibit inflammatory cytokine expression, and increase phosphorylation of p38 MAPK and NF-κB p65 in the lungs of COPD rats. The protective mechanism of HSYA to inhibit COPD inflammation might be by attenuating NF-κB and p38 MAPK signal transduction.展开更多
Mitogen-activated protein kinase(MAPK)cascades are key signaling modules downstream of receptors/sensors that perceive either endogenously produced stimuli such as peptide ligands and damage-associated molecular patte...Mitogen-activated protein kinase(MAPK)cascades are key signaling modules downstream of receptors/sensors that perceive either endogenously produced stimuli such as peptide ligands and damage-associated molecular patterns(DAMPs)or exogenously originated stimuli such as pathogen/microbe-associated molecular patterns(P/MAMPs),pathogen-derived effectors,and environmental factors.In this review,we provide a historic view of plant MAPK research and summarize recent advances in the establishment of MAPK cascades as essential components in plant immunity,response to environmental stresses,and normal growth and development.Each tier of the MAPK cascades is encoded by a small gene family,and multi ple members can function redundantly in an MAPK cascade.Yet,they carry out a diverse array of biological functions in plants.How the signaling specificity is achieved has become an interesting topic of MAPK research.Future investigations into the molecular mechanism(s)underlying the regulation of MAPK activation including the activation kinetics and magnitude in response to a stimulus,the spatiotemporal expression patterns of all the components in the signaling pathway,and functional characterization of novel MAPK substrates are central to our understanding of MAPK functions and signaling specificity in plants.展开更多
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.
文摘The mitogen-activated protein kinase(MAPK) interacting protein kinases 1 and 2(Mnk1 and Mnk2) play important roles in controlling signals involved in mRNA translation. In addition to the MAPKs(p38 or Erk), multiple studies suggest that the Mnk kinases can be regulated by other known kinases such as Pak2 and/or other unidentified kinases by phosphorylation of residues distinct from the sites phosphorylated by the MAPKs. Several studies have established multiple Mnk protein targets, including PSF, heterogenous nuclear ribonucleoprotein A1, Sprouty 2 and have lead to the identification of distinct biological functions and substrate specificity for the Mnk kinases. In this review we discuss the pathways regulating the Mnk kinases, their known substrates as well as the functional consequences of engagement of pathways controlled by Mnk kinases. These kinases play an important role in mRNA translation via their regulation of eukaryotic initiation factor 4E(eIF4E) and their functions have important implications in tumor biology as well as the regulation of drug resistance to anti-oncogenic therapies. Other studies have identified a role for the Mnk kinases in cap-independent mRNA translation, suggesting that the Mnk kinases can exert important functional effects independently of the phosphorylation of eIF4 E. The role of Mnk kinases in inflammation and inflammationinduced malignancies is also discussed.
基金Supported by A Grant-in-Aid from the Ministry of HealthLabour and Welfare of Japan+2 种基金No.KHD1017by that from JSTPRESTO
文摘AIM: To identify kinases involved in phenotype regulation of vascular endothelial cells(VECs): Proproliferative G-protein signaling 5(RGS5)^(high)(typeⅠ) vs anti-proliferative RGS5^(low)(typeⅡ) VECs.METHODS: Proteomic kinase assays were performed to identify the crucial kinase involved in the phenotype regulation of human VECs using typeⅠ VECs, which promotes the proliferation of human vascular smooth muscle cells(VSMCs), and typeⅡ VECs, which suppress the proliferation of human VSMCs. The assays were performed using multiple pairs of typeⅠ and typeⅡ VECs to obtain the least number of candidates. The involvement of the candidate kinases was verified by evaluating the effects of their specific inhibitors on the phenotype regulation of human VECs as well as the expression levels of regulator of RGS5, which is the causative gene for the "typeⅡ to typeⅠ" phenotype conversion of human VECs. RESULTS: p38α mitogen-activated protein kinase(p38α MAPK) was the only kinase that showed distinctive activities between typeⅠ and typeⅡ VECs: p38α MAPK activities were low and high in type-Ⅰand typeⅡ VECs, respectively. We found that an enforced expression of RGS5 indeed lowered p38α MAPK activitiesin typeⅡ VECs. Furthermore, treatments with a p38α MAPK inhibitor nullified the anti-proliferative potential in typeⅡ VECs. Interestingly, MAPK inhibitor treatments enhanced the induction of RGS5 gene. Thus, there is a vicious cycle between "RGS5 induction" and "p38α MAPK inhibition", which can explain the unidirectional process in the stress-induced "typeⅡ to typeⅠ" conversions of human VECs. To understand the upstream signaling of RGS5, which is known as an inhibitory molecule against the G protein-coupled receptor(GPCR)-mediated signaling, we examined the effects of RGS5 overexpression on the signaling events from sphingosine-1-phosphate(S1P) to N-cadherin, because S1 P receptors belong to the GPCR family gene and N-cadherin, one of their downstream effectors, is reportedly involved in the regulation of VEC-VSMC interactions. We found that RGS5 specifically bound with S1P1. Moreover, N-cadherin localization at intercellular junctions in typeⅡ VECs was abolished by "RGS5 overexpression" and "p38α MAPK inhibition".CONCLUSION: p38α MAPK plays crucial roles in "type-Ⅰ vs type-Ⅱ" phenotype regulations of human VECs at the downstream of RGS5.
文摘Transcription factors can be used to engineer plants for enhanced productivity.However,the mechanism(s)by which the C2H2-type zinc fi nger transcription factor enhances pathogen resistance in cells is not fully understood.Here,Agrobacterium tumefaciens carrying the gene for Arabidopsis thaliana cysteine2/histidine2-type transcription factor 6(ZAT6)was used to engineer rice(Oryza sativa L.),cotton(Gossypium hirsutum L.),and slash pine(Pinus elliottii Engelm.)to generate transgenic cell lines.Transgenic cells were then inoculated with the pathogenic bacterium Pseudomonas syringae.Compared to the control,cell viability of transgenic cells increased 39–47%and growth rate increased 9–15%by 7 days after inoculation in rice,cotton and slash pine.Acid phosphatase activity and alkaline phosphatase activity and transcript levels of Ca 2+-dependent protein kinase genes OsCPK1,OsCPK2,OsCPK6,and OsCPK8 and mitogen-activated protein kinase genes OsMAPK1,OsMAPK2,OsMAPK3,and OsMAPK8 increased signifi cantly in transgenic rice cells by 3 day after inoculation,and extracellular pH had decreased by 10–14%by 96 min after inoculation in transgenic rice,cotton and slash pine cells.These results suggest that ZAT6 enhances P.syringae resistance in plant cells by modulating transcription of CPK and MAPK and oxidase activity.
基金Supported by the National Natural Science Foundation of China(No.81270103)the Natural Science Foundation of Beijing(No.7132047)the Project of Integrated Traditional Chinese Medicine-Western Medicine Institute of Heart Lung and Blood Vessel Diseases
文摘Objective: To investigate the attenuating effect of Hydroxysafflor yellow A(HSYA) on inflammatory injury in chronic obstructive pulmonary disease(COPD). Methods: Rats were randomly assigned to 7 groups according to body weight including normal control group, HSYA blank group(76.8 mg/kg), COPD group, COPD+HSYA(30, 48, 76.8 mg/kg) groups and COPD+dexamethasone(2 mg/kg), 10 in each group. Passive cigarette smoke and intratracheal instil ation of lipopolysaccharides were used to establish a COPD model in rats. Hematoxylin and eosin staining of lung tissue sections was used, real-time polymerase chain reaction(PCR) was used to assay m RNA levels of some cytokines in lung tissues, the cytokines in bronchoalveolar lavage fluid(BALF) were measured by enzyme-linked immunosorbent assay(ELISA), Western blot analysis was used to determine phosphorylated p38 mitogen-activated protein kinase(MAPK) levels in lung tissues, and nuclear factor-κB(NF-κB) p65 protein levels in lung tissues were detected by immunohistochemistry. Results: Lung alveolar septa destruction, alveolus fusion, inflammatory cel infiltration, and bronchiole exudation were observed. These pathological changes were al eviated in the COPD+HSYA group. The m RNA expression of inflammatory factors were significantly increased in lung tissues from COPD rats(all P<0.01) and were inhibited by HSYA. Levels of inflammatory cytokines in BALF of COPD rats were significantly increased(all P<0.01) which were inhibited by HSYA(all P<0.01, 48, 76.8 mg/kg). The levels of p38 MAPK phosphorylation and p65 in lung tissues of COPD rats were significantly increased(al P<0.01) and were suppressed by HSYA(all P<0.01, 48, 76.8 mg/kg). Conclusions: HSYA could alleviate inflammatory cell infiltration and other pathological changes in the lungs of COPD rats. HSYA could inhibit inflammatory cytokine expression, and increase phosphorylation of p38 MAPK and NF-κB p65 in the lungs of COPD rats. The protective mechanism of HSYA to inhibit COPD inflammation might be by attenuating NF-κB and p38 MAPK signal transduction.
基金supported by the Zhongshan Young Principal Investigator award from Nanjing Agricultural University and a grant from Jiangsu Provincial Post-doctoral Research Funding Program(2020Z325)。
文摘Mitogen-activated protein kinase(MAPK)cascades are key signaling modules downstream of receptors/sensors that perceive either endogenously produced stimuli such as peptide ligands and damage-associated molecular patterns(DAMPs)or exogenously originated stimuli such as pathogen/microbe-associated molecular patterns(P/MAMPs),pathogen-derived effectors,and environmental factors.In this review,we provide a historic view of plant MAPK research and summarize recent advances in the establishment of MAPK cascades as essential components in plant immunity,response to environmental stresses,and normal growth and development.Each tier of the MAPK cascades is encoded by a small gene family,and multi ple members can function redundantly in an MAPK cascade.Yet,they carry out a diverse array of biological functions in plants.How the signaling specificity is achieved has become an interesting topic of MAPK research.Future investigations into the molecular mechanism(s)underlying the regulation of MAPK activation including the activation kinetics and magnitude in response to a stimulus,the spatiotemporal expression patterns of all the components in the signaling pathway,and functional characterization of novel MAPK substrates are central to our understanding of MAPK functions and signaling specificity in plants.