In patients with Alzheimer’s disease,gamma-glutamyl transferase 5(GGT5)expression has been observed to be downregulated in cerebrovascular endothelial cells.However,the functional role of GGT5 in the development of A...In patients with Alzheimer’s disease,gamma-glutamyl transferase 5(GGT5)expression has been observed to be downregulated in cerebrovascular endothelial cells.However,the functional role of GGT5 in the development of Alzheimer’s disease remains unclear.This study aimed to explore the effect of GGT5 on cognitive function and brain pathology in an APP/PS1 mouse model of Alzheimer’s disease,as well as the underlying mechanism.We observed a significant reduction in GGT5 expression in two in vitro models of Alzheimer’s disease(Aβ_(1-42)-treated hCMEC/D3 and bEnd.3 cells),as well as in the APP/PS1 mouse model.Additionally,injection of APP/PS1 mice with an adeno-associated virus encoding GGT5 enhanced hippocampal synaptic plasticity and mitigated cognitive deficits.Interestingly,increasing GGT5 expression in cerebrovascular endothelial cells reduced levels of both soluble and insoluble amyloid-βin the brains of APP/PS1 mice.This effect may be attributable to inhibition of the expression ofβ-site APP cleaving enzyme 1,which is mediated by nuclear factor-kappa B.Our findings demonstrate that GGT5 expression in cerebrovascular endothelial cells is inversely associated with Alzheimer’s disease pathogenesis,and that GGT5 upregulation mitigates cognitive deficits in APP/PS1 mice.These findings suggest that GGT5 expression in cerebrovascular endothelial cells is a potential therapeutic target and biomarker for Alzheimer’s disease.展开更多
Endogenous neural stem cells become "activated" after neuronal injury, but the activation sequence and fate of endogenous neural stem cells in focal cerebral ischemia model are little known. We evaluated the relatio...Endogenous neural stem cells become "activated" after neuronal injury, but the activation sequence and fate of endogenous neural stem cells in focal cerebral ischemia model are little known. We evaluated the relationships between neural stem cells and hypoxia-inducible factor-1α and vascular endothelial growth factor expression in a photothromobotic rat stroke model using immunohistochemistry and western blot analysis. We also evaluated the chronological changes of neural stem cells by 5-bromo-2′-deoxyuridine(BrdU) incorporation. Hypoxia-inducible factor-1α expression was initially increased from 1 hour after ischemic injury, followed by vascular endothelial growth factor expression. Hypoxia-inducible factor-1α immunoreactivity was detected in the ipsilateral cortical neurons of the infarct core and peri-infarct area. Vascular endothelial growth factor immunoreactivity was detected in bilateral cortex, but ipsilateral cortex staining intensity and numbers were greater than the contralateral cortex. Vascular endothelial growth factor immunoreactive cells were easily found along the peri-infarct area 12 hours after focal cerebral ischemia. The expression of nestin increased throughout the microvasculature in the ischemic core and the peri-infarct area in all experimental rats after 24 hours of ischemic injury. Nestin immunoreactivity increased in the subventricular zone during 12 hours to 3 days, and prominently increased in the ipsilateral cortex between 3–7 days. Nestin-labeled cells showed dual differentiation with microvessels near the infarct core and reactive astrocytes in the peri-infarct area. BrdU-labeled cells were increased gradually from day 1 in the ipsilateral subventricular zone and cortex, and numerous BrdU-labeled cells were observed in the peri-infarct area and non-lesioned cortex at 3 days. BrdU-labeled cells rather than neurons, were mainly co-labeled with nestin and GFAP. Early expressions of hypoxia-inducible factor-1α and vascular endothelial growth factor after ischemia made up the microenvironment to increase the neuronal plasticity of activated endogenous neural stem cells. Moreover, neural precursor cells after large-scale cortical injury could be recruited from the cortex nearby infarct core and subventricular zone.展开更多
Hypoxia and transforming growth factor-β1 (TGF-β1) increase vascular endothelial growth factor A (VEGFA) expression in a number of malignancies. This effect of hypoxia and TGF-β1 might be responsible for tumor ...Hypoxia and transforming growth factor-β1 (TGF-β1) increase vascular endothelial growth factor A (VEGFA) expression in a number of malignancies. This effect of hypoxia and TGF-β1 might be responsible for tumor progression and metastasis of advanced prostate cancer. In the present study, TGF-β1 was shown to induce VEGFA165 secretion from both normal cell lines (HPV7 and RWPE1) and prostate cancer cell lines (DU 145 and PC3). Conversely, hypoxia-stimulated VEGFA165 secretion was observed only in prostate cancer cell lines. Hypoxia induced TGF-β1 expression in PC3 prostate cancer cells, and the TGF-β1 type I receptor (ALK5) kinase inhibitor partially blocked hypoxia-mediated VEGFA16s secretion. This effect of hypoxia provides a novel mechanism to increase VEGFA expression in prostate cancer cells. Although autocrine signaling of VEGFA has been implicated in prostate cancer progression and metastasis, the associated mechanism is poorly characterized. VEGFA activity is mediated via VEGF receptor (VEGFR) 1 (Fit-l) and 2 (FIk-I/KDR). Whereas VEGFR-1 mRNA was detected in normal prostate epithelial cells, VEGFR-2 mRNA and VEGFR protein were expressed only in PC3 cells. VEGFA165 treatment induced phosphorylation of extracellular signal-regulated kinase 1/2 (ERKI/2) in PC3 cells but not in HPV7 cells, suggesting that the autocrine function of VEGFA may be uniquely associated with prostate cancer. Activation of VEGFR-2 by VEGFA165 was shown to enhance migration of PC3 cells. A similar effect was also observed with endogenous VEGFA induced by TGF-β1 and hypoxia. These findings illustrate that an autocrine loop of VEGFA via VEGFR-2 is critical for the tumorigenic effects of TGF-β1 and hypoxia on metastatic prostate cancers.展开更多
BACKGROUND Diabetic macular edema(DME)is the most common cause of vision loss in people with diabetes.Tight junction disruption of the retinal pigment epithelium(RPE)cells has been reported to induce DME development.S...BACKGROUND Diabetic macular edema(DME)is the most common cause of vision loss in people with diabetes.Tight junction disruption of the retinal pigment epithelium(RPE)cells has been reported to induce DME development.SMAD-specific E3 ubiquitin protein ligase(SMURF)1 was associated with the tight junctions of cells.However,the mechanism of SMURF1 in the DME process remains unclear.AIM To investigate the role of SMURF1 in RPE cell tight junction during DME.METHODS ARPE-19 cells treated with high glucose(HG)and desferrioxamine mesylate(DFX)for establishment of the DME cell model.DME mice models were constructed by streptozotocin induction.The trans-epithelial electrical resistance and permeability of RPE cells were analyzed.The expressions of tight junction-related and autophagy-related proteins were determined.The interaction between insulin like growth factor 2 mRNA binding protein 2(IGF2BP2)and SMURF1 mRNA was verified by RNA immunoprecipitation(RIP).SMURF1 N6-methyladenosine(m6A)level was detected by methylated RIP.RESULTS SMURF1 and vascular endothelial growth factor(VEGF)were upregulated in DME.SMURF1 knockdown reduced HG/DFX-induced autophagy,which protected RPE cell tight junctions and ameliorated retinal damage in DME mice.SMURF1 activated the Wnt/β-catenin-VEGF signaling pathway by promoting WNT inhibitory factor(WIF)1 ubiquitination and degradation.IGF2BP2 upregulated SMURF1 expression in an m6A modification-dependent manner.CONCLUSION M6A-modified SMURF1 promoted WIF1 ubiquitination and degradation,which activated autophagy to inhibit RPE cell tight junctions,ultimately promoting DME progression.展开更多
This study was designed to determine the levels of early endothelial progenitor cells (EPCs), apelin, vascu- lar endothelial growth factor (VEGF) and stromal cell-derived growth factor-1 (SDF-1) after acute myoc...This study was designed to determine the levels of early endothelial progenitor cells (EPCs), apelin, vascu- lar endothelial growth factor (VEGF) and stromal cell-derived growth factor-1 (SDF-1) after acute myocardial infarction (AMI), and to investigate the relationships between these cytokines and early EPCs. Early EPCs, de- fined as CD133+, KDR+, and CD34~ cells, were quantified by flow cytometry. The levels of early EPCs and those cytokines in AMI patients were significantly different from those with coronary artery disease or controls (P 〈 0.05). Plasma apelin levels were inversely correlated with Gensini score and early EPCs (both P 〈 0.01). Early EPCs, VEGF and SDF-1 showed different patterns of changes in AMI patients during the first 24 h. The trend in the change of early EPCs was proportionally correlated with that of VEGF (P 〈 0.05). AMI patients exhibited in- creased early EPCs with remarkably decreased apelin levels and enhanced VEGF levels.展开更多
AIMTo determine whether small interfering RNA (siRNA) of PGC-1α could inhibit vascular endothelial growth factor (VEGF) expression and tube formation in human retinal vascular endothelial cells (hRVECs).ME...AIMTo determine whether small interfering RNA (siRNA) of PGC-1α could inhibit vascular endothelial growth factor (VEGF) expression and tube formation in human retinal vascular endothelial cells (hRVECs).METHODShRVECs transfected with peroxisome proliferator-activated receptor-γ coactivator-1α (PGC-1α) siRNA were incubated for 24h and then placed into a normoxic (20%, O<sub>2</sub>) or hypoxic (1%, O<sub>2</sub>) environment for another 16h. PGC-1α mRNA and protein levels were detected by real-time PCR and Western blot. VEGF mRNA and protein levels were detected by real-time PCR and ELISA. Cell proliferation was evaluated by BrdU incorporation assay. Forty-eight hours after siRNA transfection, hRVECs were planted into Matrigel-coated plates and cultured under normoxic (20%, O<sub>2</sub>) or hypoxic (1%, O<sub>2</sub>) conditions for another 48h. The tube formation of hRVECs was observed under an optical microscope and quantified by counting the number of branch points and calculating the total tube length.RESULTSPGC-1α mRNA and protein levels were significantly reduced by PGC-1α siRNA, and VEGF mRNA and protein levels also decreased significantly. The percentage of BrdU-labeled cells in siPGC-1α groups were significantly decreased compared with control siRNA groups under normoxia and hypoxia in cell proliferation assay. In the tube formation assay, PGC-1α siRNA treated cells formed significantly fewer tubes.CONCLUSIONBlocking PGC-1α expression can inhibit VEGF expression in hRVECs and inhibit their ability to form tubes under both normoxic and hypoxic conditions.展开更多
AIM:To study the effects of hypoxia-inducible factor1α(HIF-1α) silencing on the proliferation of hypoxic CBRH-7919 rat hepatoma cells.METHODS:The CBRH-7919 rat hepatoma cell line was used in this study and the hypox...AIM:To study the effects of hypoxia-inducible factor1α(HIF-1α) silencing on the proliferation of hypoxic CBRH-7919 rat hepatoma cells.METHODS:The CBRH-7919 rat hepatoma cell line was used in this study and the hypoxic model was constructed using CoCl2.The HIF-1α-specific RNAi sequences were designed according to the gene coding sequence of rat HIF-1α obtained from GeneBank.The secondary structure of the HIF-1α gene sequence was analyzed using RNA draw software.The small interfering RNA(siRNA) transfection mixture was produced by mixing the siRNA and Lipofectamine2000TM,and transfected into the hypoxic hepatoma cells.Real time reverse transcription-polymerase chain reaction(RTPCR) and Western blotting assay were used to detect the expression levels of mRNA and protein.HIF-1α and vascular endothelial growth factor(VEGF) mRNA was determined using real time RT-PCR;the protein expression levels of AKT,p-AKT,p21 and cyclinD1 were determined using Western blotting.The proliferation of hepatoma cells was observed using the methyl thiazolyl tetrazolium(MTT) assay and the bromodeoxyuridine(BrdU) incorporation cell proliferation assay.RESULTS:Under induced hypoxia,the viability of the hepatoma cells reached a minimum at 800 μmol/L CoCl2;the viability of the cells was relatively high at CoCl2 concentrations between 100 μmol/L and 200 μmol/L.Under hypoxia,the mRNA and protein expression levels of HIF-1α and VEGF were significantly higher than that of hepatoma cells that were cultured in normaxia.HIF-1α-specific RNAi sequences were successfully transfected into hepatoma cells.The transfection of specific siRNAs significantly inhibited the mRNA and protein expression levels of HIF-1α and VEGF,along with the protein expression levels of p-AKT and cyclinD1;the protein expression of p21 was significantly increased,and there was no significant difference in the expression of AKT.The MTT assay showed that the amount of hepatoma cells in S phase in the siRNA transfection group was obviously smaller than that in the control group;in the siRNA transfection group,the amount of hepatoma cells in G1 phase was more than that in the control group.The BrdU incorporation assay showed that the number of BrdU positive hepatoma cells in the siRNA transfection group was less than that in the control group.The data of the MTT assay and BrdU incorporation assay suggested that HIF-1α silencing using siRNAs significantly inhibited the proliferation of hepatoma cells.CONCLUSION:Hypoxia increases the expression of HIF-1α,and HIF-1α silencing significantly inhibits the proliferation of hypoxic CBRH-7919 rat hepatoma cells.展开更多
The influence of early-stage intensive insulin therapy on the plasma levels of vascular en- dothelial growth factor (VEGF) and the related parameters in patients with severe trauma and the clini- cal implication wer...The influence of early-stage intensive insulin therapy on the plasma levels of vascular en- dothelial growth factor (VEGF) and the related parameters in patients with severe trauma and the clini- cal implication were investigated. Sixty-four cases of severe trauma (injury severity score 〉20) with stress hyperglycemia (blood glucose 〉9 mmol/L) were randomly divided into intensive insulin therapy group and conventional therapy group. ELISA method, radioimmunoassay and density gradient grada- tion one-step process were used to determine plasma VEGF, endothelin-1 (ET-1), and the number of circulating endothelial cells (CECs) at the day of 0, 2, 3, 5 and 7 after admission. Simultaneously, the changes of CRP concentration in plasma were monitored to evaluate inflammatory response. The results showed that plasma levels of observational indexes in patients receiving early-stage intensive insulin therapy were all significantly lower than those in conventional therapy groups 2, 3, 5 and 7 days after admission [for VEGF (ng/L), 122.2±23.8 vs. 135.9±26.5, 109.6±27.3 vs. 129.0±18.4, 88.7±18.2 vs. 102.6±27.3, 54.2±26.4 vs. 85.7±35.2, P〈0.05, 0.01, 0.05, 0.05 respectively; for ET-1 (ng/L), 162.8±23.5 vs. 173.7±13.2, 128.6±17.5 vs. 148.8±22.4, 96.5±14.8 vs. 125.7±14.8, 90.7±16.9 vs. 104.9±22.5, P〈0.05, 0.01, 0.01, 0.01 respectively; for CRP (mg/L), 23.2±13.8 vs. 31.9±16.5, 13.6±17.3 vs. 23.5±18.4, 8.7±10.2 vs. 15.6±13.3, 5.2±9.4 vs. 10.7±11.2, all P〈0.05; for CECs (/0.9 μL), 10.9±5.6 vs. 13.9±6.2, 8.5±4.9 vs. 11.3±5.3, 6.3±6.4 vs. 9.4±5.7, 4.8±7.1 vs. 7.8±4.8, all P〈0.05]. It was concluded that intensive insulin therapy could antagonize the endothelium injury after trauma and reduce inflammation response quickly, which was one of important mechanisms by which intensive insulin therapy improves the prognosis of trauma patients.展开更多
Summary: In order to investigate the expression of nerve growth factor (NGF) and hypoxia inducible factor-1α (HIF-1α) and its correlation with angiogenesis in non-small cell lung cancer (NSCLC), paraffin-embe...Summary: In order to investigate the expression of nerve growth factor (NGF) and hypoxia inducible factor-1α (HIF-1α) and its correlation with angiogenesis in non-small cell lung cancer (NSCLC), paraffin-embedded tissue blocks from 20 patients with NSCLC were examined. Twenty corresponding para-cancerous lung tissue specimens were obtained to serve as a control. The expression of NGF, HIF-1α, and vascular endothelial growth factor (VEGF) in the NSCLC tissues was detected by using immunohistochemistry. The microvascular density (MVD) was determined by CD31 staining. The resuits showed that the expression levels ofNGF, HIF-1α and VEGF in the NSCLC tissues were remarkably higher than those in the para-cancerous lung tissues (P〈0.05). There was significant difference in the MVD between the NSCLC tissues (9.19±1.43) and para-cancerous lung tissues (2.23±1.19) (P〈0.05). There were positive correlations between NGF and VEGF, between HIF-1α and VEGF, and between NGF and HIF-1α in NSCLC tissues, with the spearman correlation coefficient being 0.588, 0.519 and 0.588, respectively. In NSCLC tissues, the MVD had a positive correlation with the three factors (P〈0.05). Theses results suggest that NGF and HIF-1α are synergically involved in the angiogenesis of NSCLC.展开更多
Neovascularization and angiogenesis in the brain are important physiological processes for normal brain development and repair/regeneration following insults. Integrins are cell surface adhesion receptors mediating im...Neovascularization and angiogenesis in the brain are important physiological processes for normal brain development and repair/regeneration following insults. Integrins are cell surface adhesion receptors mediating important function of cells such as survival, growth and development during tissue organization, differentiation and organogenesis. In this study, we used an integrin-binding array platform to identify the important types of integrins and their binding peptides that facilitate adhesion, growth, development, and vascular-like network formation of rat primary brain microvascular endothelial cells. Brain microvascular endothelial cells were isolated from rat brain on post-natal day 7. Cells were cultured in a custom-designed integrin array system containing short synthetic peptides binding to 16 types of integrins commonly expressed on cells in vertebrates. After 7 days of culture, the brain microvascular endothelial cells were processed for immunostaining with markers for endothelial cells including von Willibrand factor and platelet endothelial cell adhesion molecule. 5-Bromo-2′-dexoyuridine was added to the culture at 48 hours prior to fixation to assess cell proliferation. Among 16 integrins tested, we found that α5β1, αvβ5 and αvβ8 greatly promoted proliferation of endothelial cells in culture. To investigate the effect of integrin-binding peptides in promoting neovascularization and angiogenesis, the binding peptides to the above three types of integrins were immobilized to our custom-designed hydrogel in three-dimensional(3 D) culture of brain microvascular endothelial cells with the addition of vascular endothelial growth factor. Following a 7-day 3 D culture, the culture was fixed and processed for double labeling of phalloidin with von Willibrand factor or platelet endothelial cell adhesion molecule and assessed under confocal microscopy. In the 3 D culture in hydrogels conjugated with the integrin-binding peptide, brain microvascular endothelial cells formed interconnected vascular-like network with clearly discernable lumens, which is reminiscent of brain microvascular network in vivo. With the novel integrin-binding array system, we identified the specific types of integrins on brain microvascular endothelial cells that mediate cell adhesion and growth followed by functionalizing a 3 D hydrogel culture system using the binding peptides that specifically bind to the identified integrins, leading to robust growth and lumenized microvascular-like network formation of brain microvascular endothelial cells in 3 D culture. This technology can be used for in vitro and in vivo vascularization of transplants or brain lesions to promote brain tissue regeneration following neurological insults.展开更多
Objective: To observe the changes of plasma concentrations of endotoxin, soluble intercellular adhesion molecule 1, tumor necrosis factor α, and urinary microalbumin in children undergoing cardiac procedure and to st...Objective: To observe the changes of plasma concentrations of endotoxin, soluble intercellular adhesion molecule 1, tumor necrosis factor α, and urinary microalbumin in children undergoing cardiac procedure and to study the effects of cardiopulmonary bypass (CPB) on the injury or activation of endothelial cells and vascular permeability. Methods: Twenty children undergoing cardiac operation with CPB were selected in the study. Plasma concentrations of endotoxin, soluble intercellular adhesion molecule 1, tumor necrosis factor α, and urinary microalbumin were measured after anesthetic induction (baseline), bypass for 20 minutes, at the end of CPB, and at 2, 4, and 18 h after the end of CPB. Results: The plasma concentrations of endotoxin, soluble intercellular adhesion molecule 1, and urinary microalbumin began to increase at 2 h after the end of CPB, and remained higher than that of the baseline, while the concentration of tumor necrosis factor α increased only at the end CPB and at 2 h after the end of CPB. Conclusion: Cardiopulmonary bypass can induce inflammatory response, resulting in the activation or injury of vascular endothelial cells, and can increase the vascular permeability.展开更多
Objective:To investigate the effect and mechanism of miRNA-24 on the proliferation,migration and tube formation of vascular endothelial cells.Methods:Human umbilical vein endothelial cells(HUVECs)were assigned into co...Objective:To investigate the effect and mechanism of miRNA-24 on the proliferation,migration and tube formation of vascular endothelial cells.Methods:Human umbilical vein endothelial cells(HUVECs)were assigned into control,microRNA(miR)-24 overexpression and anti-miR-24 groups.The proliferation and migration abilities of HUVECs were detected by methyl thiazolyl tetrazolium(MTT)assay and scratch wound healing assay,respectively.The ability of HUVECs to form tubular structures was evaluated by a tube formation assay.The mRNA and protein expressions of vascular endothelial growth factor(VEGF)and transcription factor Sp1 were determined by RT-PCR,immunocytochemistry and western blotting,respectively.Results:The miR-24 overexpression group exhibited decreased cell proliferation and migration,and expressions of VEGF and Sp1 compared with the control group(P <0.01).No tube-like network structure was formed in the miR-24 overexpression group.However,inhibition of miR-24 in HUVECs markedly increased cell proliferation and migration,enhanced tube formation and expressions of VEGF and Sp1(P<0.05 or P<0.01).Conclusion:MiR-24 suppressed the proliferation,migration and tube formation of HUVECs,and the mechanism might be related to the down-regulation of VEGF expression.Sp1 might participate in this regulation process.展开更多
Objective:To study the effect of estrogen on anovulatory dysfunctional uterine bleeding(ADUB).Methods:Primary endometrial epithelial cells of Hainan Lizu female was cultured and hydrolylic activity of gelalinase was d...Objective:To study the effect of estrogen on anovulatory dysfunctional uterine bleeding(ADUB).Methods:Primary endometrial epithelial cells of Hainan Lizu female was cultured and hydrolylic activity of gelalinase was determined by gelatin zymography analysis.Cellular mRNA and protein synthesis was blocked respectively to determine whether the increased expression of MMP-2/9 was induced by estrogen.The expression of VEGF was blocked by siRNA.After treatment with various factors.MMP-9,VEGF,total Erk and phosphorylated Erk expression in primary uterine epithelial cells was detected by Western blotting analysis.Cell MMP-2/9mRNA levels was measured by real-time RT-PCR.Results:The activity and expression of MMP2/9 was inereased in the endometrium of patients with ADUB.Estrogen could up-regulate the expression of VEGF and activate Erk 1/2-Elk1 signal path.After interference by siRNA,ERK1/2 pathway was blocked in cells,and the expression of MMP-2/9 was down-regulated.ERK1/2 specific blocker U0126 blocked ERK phosphorylation,and it could down-regulate the expression of MMP-2/9.Conclusions:The results showed that the estrogen can increase the expression of VEGF,and thus activate ERK1/2 pathway to induce MMP-2/9 expression.展开更多
基金supported by STI2030-Major Projects,No.2021ZD 0201801(to JG)Shanxi Province Basic Research Program,No.20210302123429(to QS).
文摘In patients with Alzheimer’s disease,gamma-glutamyl transferase 5(GGT5)expression has been observed to be downregulated in cerebrovascular endothelial cells.However,the functional role of GGT5 in the development of Alzheimer’s disease remains unclear.This study aimed to explore the effect of GGT5 on cognitive function and brain pathology in an APP/PS1 mouse model of Alzheimer’s disease,as well as the underlying mechanism.We observed a significant reduction in GGT5 expression in two in vitro models of Alzheimer’s disease(Aβ_(1-42)-treated hCMEC/D3 and bEnd.3 cells),as well as in the APP/PS1 mouse model.Additionally,injection of APP/PS1 mice with an adeno-associated virus encoding GGT5 enhanced hippocampal synaptic plasticity and mitigated cognitive deficits.Interestingly,increasing GGT5 expression in cerebrovascular endothelial cells reduced levels of both soluble and insoluble amyloid-βin the brains of APP/PS1 mice.This effect may be attributable to inhibition of the expression ofβ-site APP cleaving enzyme 1,which is mediated by nuclear factor-kappa B.Our findings demonstrate that GGT5 expression in cerebrovascular endothelial cells is inversely associated with Alzheimer’s disease pathogenesis,and that GGT5 upregulation mitigates cognitive deficits in APP/PS1 mice.These findings suggest that GGT5 expression in cerebrovascular endothelial cells is a potential therapeutic target and biomarker for Alzheimer’s disease.
基金supported by the National Research Foundation of Korea Grant funded by the Korean Government,No.NRF-013-2011-1-E00045
文摘Endogenous neural stem cells become "activated" after neuronal injury, but the activation sequence and fate of endogenous neural stem cells in focal cerebral ischemia model are little known. We evaluated the relationships between neural stem cells and hypoxia-inducible factor-1α and vascular endothelial growth factor expression in a photothromobotic rat stroke model using immunohistochemistry and western blot analysis. We also evaluated the chronological changes of neural stem cells by 5-bromo-2′-deoxyuridine(BrdU) incorporation. Hypoxia-inducible factor-1α expression was initially increased from 1 hour after ischemic injury, followed by vascular endothelial growth factor expression. Hypoxia-inducible factor-1α immunoreactivity was detected in the ipsilateral cortical neurons of the infarct core and peri-infarct area. Vascular endothelial growth factor immunoreactivity was detected in bilateral cortex, but ipsilateral cortex staining intensity and numbers were greater than the contralateral cortex. Vascular endothelial growth factor immunoreactive cells were easily found along the peri-infarct area 12 hours after focal cerebral ischemia. The expression of nestin increased throughout the microvasculature in the ischemic core and the peri-infarct area in all experimental rats after 24 hours of ischemic injury. Nestin immunoreactivity increased in the subventricular zone during 12 hours to 3 days, and prominently increased in the ipsilateral cortex between 3–7 days. Nestin-labeled cells showed dual differentiation with microvessels near the infarct core and reactive astrocytes in the peri-infarct area. BrdU-labeled cells were increased gradually from day 1 in the ipsilateral subventricular zone and cortex, and numerous BrdU-labeled cells were observed in the peri-infarct area and non-lesioned cortex at 3 days. BrdU-labeled cells rather than neurons, were mainly co-labeled with nestin and GFAP. Early expressions of hypoxia-inducible factor-1α and vascular endothelial growth factor after ischemia made up the microenvironment to increase the neuronal plasticity of activated endogenous neural stem cells. Moreover, neural precursor cells after large-scale cortical injury could be recruited from the cortex nearby infarct core and subventricular zone.
文摘Hypoxia and transforming growth factor-β1 (TGF-β1) increase vascular endothelial growth factor A (VEGFA) expression in a number of malignancies. This effect of hypoxia and TGF-β1 might be responsible for tumor progression and metastasis of advanced prostate cancer. In the present study, TGF-β1 was shown to induce VEGFA165 secretion from both normal cell lines (HPV7 and RWPE1) and prostate cancer cell lines (DU 145 and PC3). Conversely, hypoxia-stimulated VEGFA165 secretion was observed only in prostate cancer cell lines. Hypoxia induced TGF-β1 expression in PC3 prostate cancer cells, and the TGF-β1 type I receptor (ALK5) kinase inhibitor partially blocked hypoxia-mediated VEGFA16s secretion. This effect of hypoxia provides a novel mechanism to increase VEGFA expression in prostate cancer cells. Although autocrine signaling of VEGFA has been implicated in prostate cancer progression and metastasis, the associated mechanism is poorly characterized. VEGFA activity is mediated via VEGF receptor (VEGFR) 1 (Fit-l) and 2 (FIk-I/KDR). Whereas VEGFR-1 mRNA was detected in normal prostate epithelial cells, VEGFR-2 mRNA and VEGFR protein were expressed only in PC3 cells. VEGFA165 treatment induced phosphorylation of extracellular signal-regulated kinase 1/2 (ERKI/2) in PC3 cells but not in HPV7 cells, suggesting that the autocrine function of VEGFA may be uniquely associated with prostate cancer. Activation of VEGFR-2 by VEGFA165 was shown to enhance migration of PC3 cells. A similar effect was also observed with endogenous VEGFA induced by TGF-β1 and hypoxia. These findings illustrate that an autocrine loop of VEGFA via VEGFR-2 is critical for the tumorigenic effects of TGF-β1 and hypoxia on metastatic prostate cancers.
基金Supported by Natural Science Foundation of Guangdong Province,No.2022A1515012346.
文摘BACKGROUND Diabetic macular edema(DME)is the most common cause of vision loss in people with diabetes.Tight junction disruption of the retinal pigment epithelium(RPE)cells has been reported to induce DME development.SMAD-specific E3 ubiquitin protein ligase(SMURF)1 was associated with the tight junctions of cells.However,the mechanism of SMURF1 in the DME process remains unclear.AIM To investigate the role of SMURF1 in RPE cell tight junction during DME.METHODS ARPE-19 cells treated with high glucose(HG)and desferrioxamine mesylate(DFX)for establishment of the DME cell model.DME mice models were constructed by streptozotocin induction.The trans-epithelial electrical resistance and permeability of RPE cells were analyzed.The expressions of tight junction-related and autophagy-related proteins were determined.The interaction between insulin like growth factor 2 mRNA binding protein 2(IGF2BP2)and SMURF1 mRNA was verified by RNA immunoprecipitation(RIP).SMURF1 N6-methyladenosine(m6A)level was detected by methylated RIP.RESULTS SMURF1 and vascular endothelial growth factor(VEGF)were upregulated in DME.SMURF1 knockdown reduced HG/DFX-induced autophagy,which protected RPE cell tight junctions and ameliorated retinal damage in DME mice.SMURF1 activated the Wnt/β-catenin-VEGF signaling pathway by promoting WNT inhibitory factor(WIF)1 ubiquitination and degradation.IGF2BP2 upregulated SMURF1 expression in an m6A modification-dependent manner.CONCLUSION M6A-modified SMURF1 promoted WIF1 ubiquitination and degradation,which activated autophagy to inhibit RPE cell tight junctions,ultimately promoting DME progression.
基金supported by the program (No. CX10B_421Z to Jiaxin Ye) for Postgraduate Research Innovation in Universities of Jiangsu Provincethe grants (No. 81070195) and (No. 81000055) from Chinese National Science Fund of China (all to Biao Xu)grant (No.KF200938 to Lina Kang) from Jiangsu Province
文摘This study was designed to determine the levels of early endothelial progenitor cells (EPCs), apelin, vascu- lar endothelial growth factor (VEGF) and stromal cell-derived growth factor-1 (SDF-1) after acute myocardial infarction (AMI), and to investigate the relationships between these cytokines and early EPCs. Early EPCs, de- fined as CD133+, KDR+, and CD34~ cells, were quantified by flow cytometry. The levels of early EPCs and those cytokines in AMI patients were significantly different from those with coronary artery disease or controls (P 〈 0.05). Plasma apelin levels were inversely correlated with Gensini score and early EPCs (both P 〈 0.01). Early EPCs, VEGF and SDF-1 showed different patterns of changes in AMI patients during the first 24 h. The trend in the change of early EPCs was proportionally correlated with that of VEGF (P 〈 0.05). AMI patients exhibited in- creased early EPCs with remarkably decreased apelin levels and enhanced VEGF levels.
基金Supported by National Natural Science Fundation of China(No.81000387)
文摘AIMTo determine whether small interfering RNA (siRNA) of PGC-1α could inhibit vascular endothelial growth factor (VEGF) expression and tube formation in human retinal vascular endothelial cells (hRVECs).METHODShRVECs transfected with peroxisome proliferator-activated receptor-γ coactivator-1α (PGC-1α) siRNA were incubated for 24h and then placed into a normoxic (20%, O<sub>2</sub>) or hypoxic (1%, O<sub>2</sub>) environment for another 16h. PGC-1α mRNA and protein levels were detected by real-time PCR and Western blot. VEGF mRNA and protein levels were detected by real-time PCR and ELISA. Cell proliferation was evaluated by BrdU incorporation assay. Forty-eight hours after siRNA transfection, hRVECs were planted into Matrigel-coated plates and cultured under normoxic (20%, O<sub>2</sub>) or hypoxic (1%, O<sub>2</sub>) conditions for another 48h. The tube formation of hRVECs was observed under an optical microscope and quantified by counting the number of branch points and calculating the total tube length.RESULTSPGC-1α mRNA and protein levels were significantly reduced by PGC-1α siRNA, and VEGF mRNA and protein levels also decreased significantly. The percentage of BrdU-labeled cells in siPGC-1α groups were significantly decreased compared with control siRNA groups under normoxia and hypoxia in cell proliferation assay. In the tube formation assay, PGC-1α siRNA treated cells formed significantly fewer tubes.CONCLUSIONBlocking PGC-1α expression can inhibit VEGF expression in hRVECs and inhibit their ability to form tubes under both normoxic and hypoxic conditions.
基金Supported by Natural Science Foundation of Guangdong Province People’s Republic of China,No. 10151008901000182
文摘AIM:To study the effects of hypoxia-inducible factor1α(HIF-1α) silencing on the proliferation of hypoxic CBRH-7919 rat hepatoma cells.METHODS:The CBRH-7919 rat hepatoma cell line was used in this study and the hypoxic model was constructed using CoCl2.The HIF-1α-specific RNAi sequences were designed according to the gene coding sequence of rat HIF-1α obtained from GeneBank.The secondary structure of the HIF-1α gene sequence was analyzed using RNA draw software.The small interfering RNA(siRNA) transfection mixture was produced by mixing the siRNA and Lipofectamine2000TM,and transfected into the hypoxic hepatoma cells.Real time reverse transcription-polymerase chain reaction(RTPCR) and Western blotting assay were used to detect the expression levels of mRNA and protein.HIF-1α and vascular endothelial growth factor(VEGF) mRNA was determined using real time RT-PCR;the protein expression levels of AKT,p-AKT,p21 and cyclinD1 were determined using Western blotting.The proliferation of hepatoma cells was observed using the methyl thiazolyl tetrazolium(MTT) assay and the bromodeoxyuridine(BrdU) incorporation cell proliferation assay.RESULTS:Under induced hypoxia,the viability of the hepatoma cells reached a minimum at 800 μmol/L CoCl2;the viability of the cells was relatively high at CoCl2 concentrations between 100 μmol/L and 200 μmol/L.Under hypoxia,the mRNA and protein expression levels of HIF-1α and VEGF were significantly higher than that of hepatoma cells that were cultured in normaxia.HIF-1α-specific RNAi sequences were successfully transfected into hepatoma cells.The transfection of specific siRNAs significantly inhibited the mRNA and protein expression levels of HIF-1α and VEGF,along with the protein expression levels of p-AKT and cyclinD1;the protein expression of p21 was significantly increased,and there was no significant difference in the expression of AKT.The MTT assay showed that the amount of hepatoma cells in S phase in the siRNA transfection group was obviously smaller than that in the control group;in the siRNA transfection group,the amount of hepatoma cells in G1 phase was more than that in the control group.The BrdU incorporation assay showed that the number of BrdU positive hepatoma cells in the siRNA transfection group was less than that in the control group.The data of the MTT assay and BrdU incorporation assay suggested that HIF-1α silencing using siRNAs significantly inhibited the proliferation of hepatoma cells.CONCLUSION:Hypoxia increases the expression of HIF-1α,and HIF-1α silencing significantly inhibits the proliferation of hypoxic CBRH-7919 rat hepatoma cells.
基金supported by the National Natural Science Foundation of China (No. 30700869)
文摘The influence of early-stage intensive insulin therapy on the plasma levels of vascular en- dothelial growth factor (VEGF) and the related parameters in patients with severe trauma and the clini- cal implication were investigated. Sixty-four cases of severe trauma (injury severity score 〉20) with stress hyperglycemia (blood glucose 〉9 mmol/L) were randomly divided into intensive insulin therapy group and conventional therapy group. ELISA method, radioimmunoassay and density gradient grada- tion one-step process were used to determine plasma VEGF, endothelin-1 (ET-1), and the number of circulating endothelial cells (CECs) at the day of 0, 2, 3, 5 and 7 after admission. Simultaneously, the changes of CRP concentration in plasma were monitored to evaluate inflammatory response. The results showed that plasma levels of observational indexes in patients receiving early-stage intensive insulin therapy were all significantly lower than those in conventional therapy groups 2, 3, 5 and 7 days after admission [for VEGF (ng/L), 122.2±23.8 vs. 135.9±26.5, 109.6±27.3 vs. 129.0±18.4, 88.7±18.2 vs. 102.6±27.3, 54.2±26.4 vs. 85.7±35.2, P〈0.05, 0.01, 0.05, 0.05 respectively; for ET-1 (ng/L), 162.8±23.5 vs. 173.7±13.2, 128.6±17.5 vs. 148.8±22.4, 96.5±14.8 vs. 125.7±14.8, 90.7±16.9 vs. 104.9±22.5, P〈0.05, 0.01, 0.01, 0.01 respectively; for CRP (mg/L), 23.2±13.8 vs. 31.9±16.5, 13.6±17.3 vs. 23.5±18.4, 8.7±10.2 vs. 15.6±13.3, 5.2±9.4 vs. 10.7±11.2, all P〈0.05; for CECs (/0.9 μL), 10.9±5.6 vs. 13.9±6.2, 8.5±4.9 vs. 11.3±5.3, 6.3±6.4 vs. 9.4±5.7, 4.8±7.1 vs. 7.8±4.8, all P〈0.05]. It was concluded that intensive insulin therapy could antagonize the endothelium injury after trauma and reduce inflammation response quickly, which was one of important mechanisms by which intensive insulin therapy improves the prognosis of trauma patients.
基金supported by the Scientific Research Program of Health Department of Hubei Province,China(No.JX6B04)
文摘Summary: In order to investigate the expression of nerve growth factor (NGF) and hypoxia inducible factor-1α (HIF-1α) and its correlation with angiogenesis in non-small cell lung cancer (NSCLC), paraffin-embedded tissue blocks from 20 patients with NSCLC were examined. Twenty corresponding para-cancerous lung tissue specimens were obtained to serve as a control. The expression of NGF, HIF-1α, and vascular endothelial growth factor (VEGF) in the NSCLC tissues was detected by using immunohistochemistry. The microvascular density (MVD) was determined by CD31 staining. The resuits showed that the expression levels ofNGF, HIF-1α and VEGF in the NSCLC tissues were remarkably higher than those in the para-cancerous lung tissues (P〈0.05). There was significant difference in the MVD between the NSCLC tissues (9.19±1.43) and para-cancerous lung tissues (2.23±1.19) (P〈0.05). There were positive correlations between NGF and VEGF, between HIF-1α and VEGF, and between NGF and HIF-1α in NSCLC tissues, with the spearman correlation coefficient being 0.588, 0.519 and 0.588, respectively. In NSCLC tissues, the MVD had a positive correlation with the three factors (P〈0.05). Theses results suggest that NGF and HIF-1α are synergically involved in the angiogenesis of NSCLC.
基金supported by NIH grant RO1 NS093985 (to DS, NZ, XW) and RO1 NS101955 (to DS)the VCU Microscopy Facility,supported,in part,by funding from NIH-NCI Cancer Center Support Grant P30 CA016059。
文摘Neovascularization and angiogenesis in the brain are important physiological processes for normal brain development and repair/regeneration following insults. Integrins are cell surface adhesion receptors mediating important function of cells such as survival, growth and development during tissue organization, differentiation and organogenesis. In this study, we used an integrin-binding array platform to identify the important types of integrins and their binding peptides that facilitate adhesion, growth, development, and vascular-like network formation of rat primary brain microvascular endothelial cells. Brain microvascular endothelial cells were isolated from rat brain on post-natal day 7. Cells were cultured in a custom-designed integrin array system containing short synthetic peptides binding to 16 types of integrins commonly expressed on cells in vertebrates. After 7 days of culture, the brain microvascular endothelial cells were processed for immunostaining with markers for endothelial cells including von Willibrand factor and platelet endothelial cell adhesion molecule. 5-Bromo-2′-dexoyuridine was added to the culture at 48 hours prior to fixation to assess cell proliferation. Among 16 integrins tested, we found that α5β1, αvβ5 and αvβ8 greatly promoted proliferation of endothelial cells in culture. To investigate the effect of integrin-binding peptides in promoting neovascularization and angiogenesis, the binding peptides to the above three types of integrins were immobilized to our custom-designed hydrogel in three-dimensional(3 D) culture of brain microvascular endothelial cells with the addition of vascular endothelial growth factor. Following a 7-day 3 D culture, the culture was fixed and processed for double labeling of phalloidin with von Willibrand factor or platelet endothelial cell adhesion molecule and assessed under confocal microscopy. In the 3 D culture in hydrogels conjugated with the integrin-binding peptide, brain microvascular endothelial cells formed interconnected vascular-like network with clearly discernable lumens, which is reminiscent of brain microvascular network in vivo. With the novel integrin-binding array system, we identified the specific types of integrins on brain microvascular endothelial cells that mediate cell adhesion and growth followed by functionalizing a 3 D hydrogel culture system using the binding peptides that specifically bind to the identified integrins, leading to robust growth and lumenized microvascular-like network formation of brain microvascular endothelial cells in 3 D culture. This technology can be used for in vitro and in vivo vascularization of transplants or brain lesions to promote brain tissue regeneration following neurological insults.
文摘Objective: To observe the changes of plasma concentrations of endotoxin, soluble intercellular adhesion molecule 1, tumor necrosis factor α, and urinary microalbumin in children undergoing cardiac procedure and to study the effects of cardiopulmonary bypass (CPB) on the injury or activation of endothelial cells and vascular permeability. Methods: Twenty children undergoing cardiac operation with CPB were selected in the study. Plasma concentrations of endotoxin, soluble intercellular adhesion molecule 1, tumor necrosis factor α, and urinary microalbumin were measured after anesthetic induction (baseline), bypass for 20 minutes, at the end of CPB, and at 2, 4, and 18 h after the end of CPB. Results: The plasma concentrations of endotoxin, soluble intercellular adhesion molecule 1, and urinary microalbumin began to increase at 2 h after the end of CPB, and remained higher than that of the baseline, while the concentration of tumor necrosis factor α increased only at the end CPB and at 2 h after the end of CPB. Conclusion: Cardiopulmonary bypass can induce inflammatory response, resulting in the activation or injury of vascular endothelial cells, and can increase the vascular permeability.
基金supported by the National Natural Science Foundation of China(No.81373403)
文摘Objective:To investigate the effect and mechanism of miRNA-24 on the proliferation,migration and tube formation of vascular endothelial cells.Methods:Human umbilical vein endothelial cells(HUVECs)were assigned into control,microRNA(miR)-24 overexpression and anti-miR-24 groups.The proliferation and migration abilities of HUVECs were detected by methyl thiazolyl tetrazolium(MTT)assay and scratch wound healing assay,respectively.The ability of HUVECs to form tubular structures was evaluated by a tube formation assay.The mRNA and protein expressions of vascular endothelial growth factor(VEGF)and transcription factor Sp1 were determined by RT-PCR,immunocytochemistry and western blotting,respectively.Results:The miR-24 overexpression group exhibited decreased cell proliferation and migration,and expressions of VEGF and Sp1 compared with the control group(P <0.01).No tube-like network structure was formed in the miR-24 overexpression group.However,inhibition of miR-24 in HUVECs markedly increased cell proliferation and migration,enhanced tube formation and expressions of VEGF and Sp1(P<0.05 or P<0.01).Conclusion:MiR-24 suppressed the proliferation,migration and tube formation of HUVECs,and the mechanism might be related to the down-regulation of VEGF expression.Sp1 might participate in this regulation process.
基金supported by Natural Science Foundation of Hainan Province(No.812148)
文摘Objective:To study the effect of estrogen on anovulatory dysfunctional uterine bleeding(ADUB).Methods:Primary endometrial epithelial cells of Hainan Lizu female was cultured and hydrolylic activity of gelalinase was determined by gelatin zymography analysis.Cellular mRNA and protein synthesis was blocked respectively to determine whether the increased expression of MMP-2/9 was induced by estrogen.The expression of VEGF was blocked by siRNA.After treatment with various factors.MMP-9,VEGF,total Erk and phosphorylated Erk expression in primary uterine epithelial cells was detected by Western blotting analysis.Cell MMP-2/9mRNA levels was measured by real-time RT-PCR.Results:The activity and expression of MMP2/9 was inereased in the endometrium of patients with ADUB.Estrogen could up-regulate the expression of VEGF and activate Erk 1/2-Elk1 signal path.After interference by siRNA,ERK1/2 pathway was blocked in cells,and the expression of MMP-2/9 was down-regulated.ERK1/2 specific blocker U0126 blocked ERK phosphorylation,and it could down-regulate the expression of MMP-2/9.Conclusions:The results showed that the estrogen can increase the expression of VEGF,and thus activate ERK1/2 pathway to induce MMP-2/9 expression.