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The scientific basis of acupuncture on mesenchymal stem cells (MSCs) for treating ischemic stroke (IS) is discussed. MSCs transplantation has great potential for the treatment of tissue damage caused by early stage inflammatory cascade reactions of IS, but its actual transformation is limited by various factors. How to improve the homing efficiency of MSCs is the primary issue to enhance its efficacy. As such, the possible mechanisms of acupuncture and MSCs transplantation in inhibiting inflammatory cascade reactions induced by IS are explored by reviewing literature, and a hypothesis that acupuncture could promote the secretion of stromal cell-derived factor-1α (SDF-1α) from ischemic foci to regulate SDF-1α/CXC chemokine receptor 4 (CXCR4) axis, thereby improving the homing efficiency of MSCs transplantation, exerting its neuroprotective function, and improving the bed transformation ability, is proposed.
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Humans , Ischemic Stroke , Chemokine CXCL12 , Acupuncture Therapy , Mesenchymal Stem Cells , InflammationABSTRACT
Objective: To explored the effect of stromal cell-derived factor 1α (SDF-1α) on promoting the migration ability of rat adipose derived stem cells (rADSCs) by constructed the rADSCs overexpression SDF-1α via adenovirus transfection. Methods: rADSCs were isolated from adipose tissue of 6-week-old SPF Sprague Dawley rats. Morphological observation, multi-directional differentiations (osteogenic, adipogenic, and chondrogenic inductions), and flow cytometry identification were performed. Transwell cell migration experiment was used to observe and screen the optimal concentration of exogenous SDF-1α to optimize the migration ability of rADSCs; the optimal multiplicity of infection (MOI) of rADSCs was screened by observing the cell status and fluorescence expression after transfection. Then the third generation of rADSCs were divided into 4 groups: group A was pure rADSCs; group B was rADSCs co-cultured with SDF-1α at the best concentration; group C was rADSCs infected with recombinant adenovirus-mediated green fluorescent protein (Adv-GFP) with the best MOI; group D was rADSCs infected with Adv-GFP-SDF-1α overexpression adenovirus with the best MOI. Cell counting kit 8 (CCK-8) and Transwell cell migration experiment were preformed to detect and compare the effect of exogenous SDF-1α and SDF-1α overexpression on the proliferation and migration ability of rADSCs. Results: The cell morphology, multi-directional differentiations, and flow cytometry identification showed that the cultured cells were rADSCs. After screening, the optimal stimulating concentration of exogenous SDF-1α was 12.5 nmol/L; the optimal MOI of Adv-GFP adenovirus was 200; the optimal MOI of Adv-GFP-SDF-1α overexpression adenovirus was 400. CCK-8 method and Transwell cell migration experiment showed that compared with groups A and C, groups B and D could significantly improve the proliferation and migration of rADSCs ( P<0.05); the effect of group D on enhancing the migration of rADSCs was weaker than that of group B, but the effect of promoting the proliferation of rADSCs was stronger than that of group D ( P<0.05). Conclusion: SDF-1α overexpression modification on rADSCs can significantly promote the proliferation and migration ability, which may be a potential method to optimize the application of ADSCs in tissue regeneration and wound repair.
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Objective To investigate the effect of alogliptin on albuminuria in patients with early type 2 diabetic kidney disease (DKD) and the related mechanism.Methods One hundred patients with early DKD admitted in our hospital from May 2016 to May 2017 were randomly divided into two groups with 50 cases in each group.Patients in the control group were given metformin and gliclazide,while those in study group were given metformin and alogliptin,the treatment lasted for 24 weeks.The changes of urinary albumin-to-creatinine ratio (UACR),stromal cell-derived factor-1α (SDF-1α) and the fasting plasma glucose (FPG),2-h postprandial plasma glucose (2 hPPG),glycosylated hemoglobin(HbA1c) were measured before and after the treatment in two groups.Results There were no significant differences in HbA1c [(8.17± 0.46)％ vs.(8.29±0.48)％],UACR[(109±53) vs.(105±48)mg/g],SDF-1α [(1.21±0.3 9) vs.(1.17±0.35)μg/L] levels before treatment between two groups (t=0.343,0.464,0.075,all P＞0.05).After treatment,the HbA1c levels were significantly decreased in both groups (t=2.293,2.302,all P=0.03) and there was no significant difference between two groups[(6.82±0.75)％ vs.(6.93 ±0.79)％,t=0.295,P=0.77];the UACR levels were significantly reduced in both groups,but the level of study group was significantly lower than that of control group [(82±38) vs.(94±47) mg/g,t=3.320,P＜0.01];the SDF-1α levels were significantly increased in both groups,but the level of study group was significantly higher than that of control group[(3.01 ±0.38) vs.(2.76±0.42)μg/L,t=5.474,P＜0.01].There was no significant difference in the incidence of adverse reactions between the two groups [13％ (6/46) vs.12％ (6/48),x2=0.002,P＞0.05].Conclusion Alogliptin can effectively control the blood glucose,reduce urine albumin excretion and protect renal function in patients with early type 2 diabetic nephropathy,which is associated with the increased SDF-1α levels.
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Objective: To observe the change of stromal cell-derived factor 1α/cysteine X cysteine receptor 4 (SDF-1α/CXCR4) signaling pathway during the process of axial stress stimulation promoting bone regeneration, and to further explore its mechanism. Methods: A total of 72 male New Zealand white rabbits were selected to prepare the single cortical bone defect in diameter of 8 mm at the proximal end of the right tibia that repaired with deproteinized cancellous bone. All models were randomly divided into 3 groups ( n=24). Group A was treated with intraperitoneally injection of PBS; Group B was treated with stress stimulation and intraperitoneally injection of PBS; Group C was treated with stress stimulation and intraperitoneally injection of AMD3100 solution. The X-ray films were taken and Lane-Sandhu scores of bone healing were scored at 2, 4, 8, and 12 weeks after operation, while specimens were harvested for HE staining, immunohistochemical staining of vascular endothelial growth factor (VEGF) and CXCR4, and Western blot (SDF-1α and CXCR4). The bone healing area was scanned by Micro-CT at 12 weeks after operation, and the volume and density of new bone were calculated. Results: X-ray film showed that the Lane-Sandhu scores of bone healing in group B were significantly higher than those in groups A and C at 4, 8, and 12 weeks after operation ( P<0.05). Micro-CT scan showed that the bone defect was repaired in group B and the pulp cavity was re-passed at 12 weeks after operation. The volume and density of new bone were higher in group B than in groups A and C ( P<0.05). HE staining showed that the new bone growth in bone defect area and the degradation of scaffolds were faster in group B than in groups A and C after 4 weeks. The immunohistochemical staining showed that the expressions of VEGF and CXCR4 in 3 groups reached the peak at 4 weeks, and group B was higher than groups A and C ( P<0.05). Western blot analysis showed that the expressions of SDF-1α and CXCR4 in group B were significantly higher than those in groups A and C at 4 and 8 weeks after operation ( P<0.05). Conclusion: Axial stress stimulation can promote the expression of SDF-1α in bone defect tissue, activate and regulate the CXCR4 signal collected by marrow mesenchymal stem cells, and accelerate bone regeneration in bone defect area.
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OBJECTIVE: To observe the effect of electroacupuncture (EA) of "Baihui" (GV20) and "Zusanli" (ST36) on the expression of stromal cell derived factor-1α (SDF-1α) and CD34 in ischemic cortex tissue of cerebral ische-mia /reperfusion injury (CI/RI) rats, so as to study its mechanisms underlying improving CI/RI. METHODS: Thirty male SD rats were equally and randomly divided into sham operation, model and EA groups (n=10 rats in each group). The CI/RI model was established by occlusion of the middle cerebral artery for 120 min, followed by reperfusion. EA (40 Hz, 1-2 mA) was applied to GV20 and left ST36 for 20 min, once daily for successive 14 days. The neurological deficit severity was assessed by using Longa's and colleagues' methods. The histopathological changes of the ischemic tissues were observed after H.E. staining and the expression of SDF-1α and CD34 in the ischemic cortex tissues was detected by immunohistochemistry. RESULTS: After modeling, the neurological deficit score, and the numbers of SDF-1α and CD34-positive cells in the ischemic cerebral cortex tissue were significantly increased in the model group (P<0.05). Following EA intervention, the increased neurological deficit score was reversed at the 3rd, 7th and 14th day, and the increased SDF-1α and CD34-positive cells were significantly further up-regulated in the EA group (P<0.05). H.E. staining showed tissue edema, widening of the intercellular space, cavitation-like changes, neuronal shrinkage, nuclear pyknosis with hyperchroma or even disappearance, and aggregation of inflammatory and neurogliocytes in the model group. These situations were relatively milder in the EA group. CONCLUSION: EA of GV20 and ST36 can improve neurological function of CI/RI rats, which may be associated with its effect in up-regulating the expression of SDF-1α and CD34 proteins in the ischemic cerebral cortex tissues.
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Stroke is the leading cause of death in Chinese currently, characterized by high incidence, high morbidity and high mortality, of which ischemic stroke accounted for 87%. However, it still lacks the ideal treatment. Stem cells are a class of cells with self-renewal ability and high differentiation potential. Stem cell transplantation breaks the irreversibility of nerve injury to post-stroke infarct area. However, stem cells also requiring specific chemokines to promote their directional migration to the injured tissue site after transplanted. Stromal cell-derived factor-1α (SDF-1α) is one of the typical chemokines. SDF-1α and its specific receptor CXCR4 can induce its migration, increase its proliferation and promote angiogenesis. In this paper, the role of SDF-1α/CXCR4 axis in the treatment of ischemic stroke in stem cells is reviewed in order to provide a theoretical basis for enhancing the efficacy of stem cell transplantation in the treatment of ischemic stroke.
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Objective: To investigate the effects of stromal cell-derived factor-1α (SDF-1α)through CXC-domain chemokine receptor 4 (CXCR4) and CXCR7 on colonic cancer cells resistant to 5-fluorouracil (5-FU), and to explore its possible mechanism. Methods: The expression levels of CXCR4 and CXCR7 in colonic cancer SW480, SW620, HCT116 and HT29 cells were detected by Western blotting. After treatment with SDF-1α, SDF-1α in combination with AMD3100 (CXCR4 inhibitor) or SDF-1α in combination with anti-CXCR7 monoclonal antibody for 6 hours, the SW480 and HT29 cells were then treated with 3.1, 6.25, 12.5, 25, 50, 100 and 150 μg/mL 5-FU for 48 hours. The half inhibitory concentration (IC50) value of 5-FU was detected by sulforhodamine B (SRB) assay. The expressions of drug-resistant proteins P-glycoprotein (P-gp) and multidrug resistance protein-1 (MRP-1) were detected by Western blotting. Results: The expression levels of CXCR4 and CXCR7 in SW480 and HT29 cells were higher than those in SW620 and HCT116 cells (all P 0.05). The expression levels of P-gp in SW480 and HT29 cells in group of SDF-1α in combination with anti-CXCR7 monoclonal antibody were lower than those in SDF-1α group (both P 0.05). The expression level of MRP-1 had no significant difference among different groups (P > 0.05). Conclusion: SDF-1α can promote the resistance to 5-FU in colonic cancer cells. This effect may be related to up-regulating the expression level of P-gp through SDF-1α/CXCR7 signal pathway.
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Objective To observe the treatment effect of early rehabilitation training on acute cerebral infarction patients with hemiplegia,and to explore its possible mechanism.Methods One hundred cases of acute cerebral infarction hemiplegia in our hospital from January 2013 to June 2016 were selected and divided into the rehabilitation training group (50 cases) and control group (50 cases).The control group was given the routine medication therapy and the rehabilitation training group was given early rehabilitation training on the basis of conventional medication therapy.The functional independence assessment (FIM),Fugl-Meyer assessment (FMA) and modified Barthel index (MBI) were used to evaluate the therapeutic effect of early rehabilitation training.The level of stromal cell-derived factor-1α (SDF-1α) in peripheral blood was measured by enzyme linked immunosorbent assay,and the level of CD34+KDR+ in peripheral blood was measured by flow cytometry.Results There was no statistically significant difference in the FIM total score,FIM sports function score,FMA score,MBI score,SDF-1α and CD34+KDR+ levels before treatment between the rehabilitation training group and the control group (P>0.05).After treatment,the FIM total score,FIM sports function score,FMA score,MBI score and SDF-1α and CD34+KDR+ levels of the rehabilitation training group were higher than those of the control group,the differences were statistically significant (P<0.05).Conclusion The effect of early rehabilitation training on acute cerebral infarction patients with hemiplegic is remarkable.The mechanism may be related to promoting the expression of SDF-1α and CD34+KDR+ in peripheral blood.
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Objective To investigate the role of stromal cell derived factor-1α (SDF-1α)-laminin (LN) crosstalk in migration and differentiation of neural stem cells (NSCs).Methods Original generation of NSCs collected from 14-day pregnant fetal rats were separated and cultivated, and the phenotype characteristics were identified with immunofluorescence. The third generation of NSCs were collected, and they were divided into four groups: poly-L-lysine (PLL) group, PLL+SDF-1α group, LN group and LN+SDF-1α group. The NSCs in PLL and LN groups were inoculated into plates coated with 0.1 mg/mL PLL or 1 mg/mL LN, and the NSCs in PLL+SDF-1α and LN+SDF-1αgroups were inoculated into plates coated with PLL or LN and 1 mg/mL SDF-1α containing medium. The effect of SDF-1α-LN crosstalk on NSCs migrated numbers was determined by using Transwell cell migration test, and the differentiation of NSCs was determined by immunofluorescence staining.Results Primary NSCs were successfully isolated and cultivated, neurospheres formed at 3-5 days with typical NSCs morphology positively expressing Nestin which was the specific antigen of NSCs. Compared with PLL group, the number of NSCs migration in PLL+SDF-1α group showed no significant change (cells: 3.00±0.99 vs. 2.3±0.67,P > 0.05). Compared with LN group, the number of NSCs migration in LN+SDF-1α group was significantly increased (cells: 85.33±9.61 vs. 31.67±5.86,P < 0.05). Immunofluorescence staining showed that the differentiation rates of PLL and PLL+SDF-1α groups were almost zero, and some early differentiation neurons were detected in LN group with the differentiation rates of (12.50±2.56)%. The differentiation of early neuronal cells was significantly increased after SDF-1α-LN crosstalk, the neuronal differentiation rate was (21.40±3.41)%, and it was significantly higher than that of LN group (P < 0.05).Conclusion SDF-1α crosstalk with LN in extracellular matrix can significantly and synergistically enhance the migration and differentiation of NSCs in vitro.
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Objective To investigate the effect of lentivirus-stromal cell-derived factor-1α-green fluorescent protein(LV-SDF-1α-GFP) on the cardiac fibroblasts, the optimum conditions of infection, the expression and secretion of the target protein. Methods The cardiac fibroblasts of neonatal rats were primarily isolated and cultured by differential adherence methods, and were observed and identifi with immunofluorescence. LV-SDF-1α-GFP with different titers and conditions was transfected into cardiac fibroblasts. The expression of fluorescence and the optimal transfection conditions were observed. LV-SDF-1α-GFP target gene virus and negative control C0N145 virus were transfected into cardiac fibroblasts. The growth curve was drawn, and the effect of transfection on the proliferation of cardiac fibroblasts was explored. The cardiac fibroblasts were transfected with the optimum transfection dose, and the expression of SDF-1α was detected by Dot-blotting. The measurement data underwent statistical analysis. Results There was no statistical difference between the cardiac fibroblasts with SDF-1α transfected lentivirus and without no-transfected SDF-1α lentivirus. The peak of the expression of SDF-1α appeared in culture day 4 and statistical analysis showed significantly difference (P<0.05). Conclusion The LV-SDF-1α-GFP vector is of higher transfection efficiency to cardiac fibroblasts with the both low cytotoxicity and ability of secreting SDF-la protein.
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BACKGROUND AND OBJECTIVES: Information about the role of the stromal cell-derived factor-1α (SDF-1α)/chemokine receptor type 4 (CXCR4) axis in ischemic postconditioning (IPOC) is currently limited. We hypothesized that the SDF-1α/CXCR4 signaling pathway is directly involved in the cardioprotective effect of IPOC. METHODS: Isolated rat hearts were divided into four groups. The control group was subjected to 30-min of regional ischemia and 2-hour of reperfusion (n=12). The IPOC group was induced with 6 cycles of 10-second reperfusion and 10-second global ischemia (n=8) in each cycle. The CXCR4 antagonist, AMD3100, was applied before reperfusion in the IPOC group (AMD+IPOC group, n=11) and control group (AMD group, n=9). Hemodynamic changes with electrocardiography were monitored and infarct size was measured. The SDF-1α, lactate dehydrogenase (LDH) and creatine kinase (CK) concentrations in perfusate were measured. We also analyzed extracellular signal-regulated kinase 1/2 (ERK1/2) and Akt phosphorylation state expression. RESULTS: IPOC significantly reduced infarct size, but AMD3100 attenuated the infarct reducing effect of IPOC. IPOC significantly decreased LDH and CK, but these effects were reversed by AMD3100. ERK1/2 and Akt phosphorylation increased with IPOC and these effects were blocked by AMD3100. CONCLUSION: Based on the results of this study, SDF-1α/CXCR4 signaling may be involved in IPOC cardioprotection and this signaling pathway couples to the ERK1/2 and Akt pathways.
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Animals , Rats , Creatine Kinase , Electrocardiography , Family Characteristics , Heart , Hemodynamics , Ischemia , Ischemic Postconditioning , L-Lactate Dehydrogenase , Phosphorylation , Phosphotransferases , Receptors, CXCR4 , Reperfusion , Reperfusion InjuryABSTRACT
Objective To explore the repair possibilities of endothelial progenitor cells (EPCs)in peripheral blood in patients with different extents of obstructive sleep apnea (OSA) through measuring the levels of pro-angiogenic factors and different subgroups EPCs in peripheral blood in patients with OSA. Methods Ninety adult patients with OSA, 30 healthy controls with matched age and gender were enrolled for this study. The subjects performed Polysomnography, were divided in-to four group based on Apnea Hypopnea Index (AHI). The serum levels of HIF-1α, SDF-1αand VEGF were assessed by ELISA. Mononuclear cells were isolated from peripheral blood with density gradient centrifugation, and flow cytometry was used to detect levels of CD133+KDR+EPC, CD133+CD34+EPC, CD34+KDR+EPC and ALDHloCD34+KDR+EPC based on AL-DH activity, and CD133, CD34, PE-KDR related cell surface markers. Results The levels of CD133+KDR+EPC, CD133+CD34+EPC, CD34+KDR+EPC were higher in OSA groups than those of control group, both of which were higher in severe OSA group than those of in mild and moderate OSA groups. The levels of ALDHloCD34+KDR+EPC were higher in mild and moderate OSA groups than that of the control groups, and the levels of ALDHloCD34+KDR+EPC were significantly lower in se-vere OSA group than those of control, mild and moderate OSA groups. Serum levels of HIF-1α. VEGF were significantly high-er in OSA groups compared to those in control groups, both of which were higher in severe OSA group than those of mild and moderate OSA groups. Serum levels of SDF-1αwere significantly lower in severe OSA groups than those of mild, moderate OSA and control groups (P<0.05). Conclusion The mobilization and recruitment of different subtypes of EPCs are obvious-ly increased in patients with OSA, but ALDHloCD34+KDR+EPC with vascular repair capacity keeps to invariability, even de-creases in patients with severe OSA, which results in endothelial damage, and increases the risk of cardiovascular disease.
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Objective To observe the effects of early rehabilitation training on endothelial progenitor cells (EPCs),stromal cell-derived factor alpha 1 (SDF-lα) and motor function recovery in hemiplegic patients with acute cerebral infarction.Methods Fifty hemiplegic patients after a first acute cerebral infarction were randomly divided into a control group (n =25) and an experimental group (n =25).Both groups of patients were given routine drug therapy,while the experimental group also received early rehabilitation (within 48 hours of onset).EPCs and SDF-1α levels in peripheral blood were measured before and after one week of treatment,and Fugl-Meyer assessments and modified Barthel index scoring were conducted at admission and after three months of treatment.Results There was no difference between the 2 groups before the treatment.After a week of treatment,however,the EPC and SDF-1α values of both groups had increased,with those of the experimental group increasing significantly more than in the control group.Spearman rank correlation analysis showed that the increase in EPCs was positively correlated with the SDF-1α increment in the first week.After 3 months of treatment,the average FMA and MBI results of the experimental group were significantly better than those of the control group.Conclusion Early rehabilitation training can help to further improve the recovery of motor function for hemiplegic patients after acute cerebral infarction.This may be related to its effect in upregulating the expression of SDF-1α,thus contributing to the mobilization of EPCs in the bone marrow.
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Objective To investigate the changes of serum stromal cell‐derived factor‐1α (SDF‐1α) in patients with diabetic peripheral neuropathy (DPN) and the influence of mouse never growth factor (MNGF) on the levels of serum SDF‐1α. Methods 180 patients with type 2 diabetes (T2DM ) were divided into T2DM with DPN (DPN group ,n=92) and T2DM without DPN (T2DM group ,n=88). 90 healthy people were select as normal control (NC group). DPN group was divided into 47 cases of MNGF treatment (A) subgroup and 45 cases of basic treatment (B) subgroup. The levels of serum SDF‐1αwere measured using ELISA method. The relationships between the levels of serum SDF‐1αand SOD ,TGF‐β1 , hsC‐RP ,and GAP‐43 were analyzed. After treatment ,the levels of serum SDF‐1α in A and B subgroups were compared. Results Compared with NC group [(0.91 ± 0.37)μg/L] ,the levels of serum SDF‐1αin T2DM and DPN group were higher [(2.58 ± 0.58) μg/L and(1.71 ± 0.43)μg/L ,respectively ,P0.05] .Multiple stepwise regression analysis showed that HbA1c ,hsC‐RP and PSCV were the independent factors related with the levels of SDF‐1αin DPN patients. Conclusion The levels of serum SDF‐1αin DPN patients are lower than in T2DM patients without DPN. MNGF may increase the level of serum SDF‐1α.
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Objective To investigate expression of CXCR4 and CXCR7 protein and mRNA, which are the receptors of stromal cell derived factor-1α(SDF-1α), in the bone marrow mesenchymal stem cells (BMSCs);to explore the role of SDF-1α/CXCR4/CXCR7 axis in migration of BMSCs in vitro and the possible mechanism .Method BMSCs were isolated from rats and cultured in vitro.CD29, CD44 and CD34 of the cells were identified by flow cytometry .CXCR4-selective antagonist AMD 3100 and CXCR7-specific neutralizing antibody were applied to block CXCR 4 and CXCR7 respectively.The expressions of CXCR4 and CXCR7 mRNA and protein on BMSCs were detected with RT-PCR and Western blotting .Transwells chamber test was used to observe the migration of BMSCs .The BMSCs were divided into the BMSCs group ( A ) , the AMD3100 pretreated BMSCs group ( B ) , the CXCR7-specific neutralizing antibody pretreated BMSCs group(C), the AMD3100 +CXCR7-specific neutralizing antibody pretreated BMSCs group ( D).Result Flow cytometry showed that the expressions of CD 44 and CD29 were positive, while the expression of CD34 was negative in the third passage of BMSCs (P3-BMSCs).CXCR4 and CXCR7 protein and mRNA were both expressed in P3-BMSCs. Compared with the A group, the expression of CXCR4 and CXCR7 protein declined significantly in the B group and the D group;the protein expression of CXCR7 in the C group was lower compared with the A group (P<0.05).However, the expression of CXCR4 mRNA and CXCR7 mRNA had no significant difference between groups .SDF-1αfactor promoted migration of BMSCs ( P <0.05 ).Compared with the 0μg/L group, the numbers of migrated cells were increased significantly in both of the 10μg/L group and the 100μg/L group ( P<0.01 ) .The number of migration of BMSCs was significantly higher in the 100μg/L group than that of the 10μg/L group ( P <0.01 ) .AMD3100 and CXCR7-specific neutralizing antibody both inhibited significantly the migration of BMSCs ( P<0.05 ) , and the attenuate effect was more significant when they worked together ( P<0.05 ) .Conclusion CXCR4 and CXCR7 receptors are co-expressed in P3-BMSCs;the SDF-1αfactor can promote the migration of BMSCs in the concentration dependent manner ;SDF-1α/CXCR4/CXCR7 axis is involved in the migration of BMSCs , and both of the CXCR4 and CXCR7 receptors have a synergistic promoting effect to the BMSCs migration .
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Aim To investigate the effects of stromal cell-derived factor-1α ( SDF-1α) on cell proliferation in primary cultured rat astrocytes and the possible mechanisms. Methods The primary cultured rat astr-cytes were treated with recombinant human SDF-1α at different concentrations, the cell proliferation was as-sessed by cell counting and 5-bromo-2’-deoxyuridine incorporation assay;intracellular calcium concentration was detected with calcium sensitive fluorescent probe;phorphorylation of extracellular regulated protein ki-nase1/2 ( ERK1/2 ) was determined by Western blot analysis;cell cycle transition was analyzed by flow cy-tometry analysis; mRNA expressions of cyclin A2 and cyclin B1 were determined by quantitative RT-PCR. Results Treatment of astrocytes with SDF-1α (5 -40 nmol·L-1 ) for 48 h induced significant cell prolifera-tion. SDF-1α at 20 nmol·L-1 increased the intracel-lular calcium concentration and the phosphorylation of ERK1/2. In addition, SDF-1α at 20 nmol·L-1 pro-moted the cell cycle transition from G0 to S and M pha-ses, and up-regulated the mRNA expressions of Cyclin A2 and Cyclin B1 . Conclusion SDF-1α significantly induces cell proliferation in primary cultured rat astro-cytes via enhancing calcium influx, ERK1/2 phospho-rylation, Cyclin expression and promoting cell cycle transition.
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Objective To investigate the stromal cell derived factor 1 α (SDF-1 α) and chemokine CXC motif receptor 4 (CXCR4) axis using acupoint electroacupuncture (EA) on the brains of rats after focal cerebral ischemia and reperfusion.Methods Ninety-eight Sprague-Dawley (SD) rats were randomly divided into a control group (8 rats),a model group (50 rats),and an EA group (40 rats).The animal model of focal brain ischemia-reperfusion was made with all the rats in the model group and EA group by using the filament occlusion technique.The model and EA groups were subdivided into 5 subgroups according to the sampling time points on the 1 st,3rd,7th,14th or 21st day after ischemia-reperfusion.The EA was administered bilaterally to the rat analog of the Hegu point (LI 4) in the EA group.The model and control groups received no special treatment.Immunohistochemical methods were employed to detect CXCR4-positive cells in the model and EA groups.The expressions of SDF-1α and CXCR4 mRNA were detected with RT-PCR methods in the 3rd,7th and 14th day subgroups.Results With the prolongation of reperfusion,SDF-1α mRNA expression in the model group had a single peak-like increase in the ischemic area of the cerebral cortex.It had increased significantly by the 3rd day,reached its peak value at the 7th day and then decreased gradually.SDF-1α mRNA expression in the EA group behaved similarly,but SDF-1 mRNA expression was significantly higher in the EA group than in the other two.In the model and EA groups CXCR4 mRNA relative values were higher at the 7th and 14th day than at day 3,and the expression at day 14 was significantly greater than at day 7.CXCR4 mRNA values in the EA group were significantly higher than in the model group at each time point.The expression of CXCR4-positive cells began to increase on the 1 st day in the model group,reached its peak value at the 7th day,then decreased by day 14,but it was still strongly expressed highly at the 21st day.Compared with the model group,the expression in the EA group showed the same pattern,but the number of CXCR4-positive cells in EA group was significantly higher.Conclusion Point EA can activate the SDF-1α and CXCR4 axis to promote angiogenesis after focal cerebral ischemia and reperfusion,at least in rats.
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Objective To investigate the effect of stromal cell-derived factor-1α( SDF-1α) and interleukin ( IL-1β) on inducing vascular endothelial cells to express lymphatic phenotype .Methods The CRL-1730 cell line was cultured and treated with SDF-1αor IL-1β.The expression of endothelial cell markers and lymphatic endothelial cell markers were investigated with Real-time PCR, Western blotting and immunocytochemistry .Results In CRL-1730 cell line, endothelial cell markers such as voln willebrand factor ( vWF ) , VE-cadherin , vascular endothelial growth factor receptor(VEGFR)2, were dose dependently down-regulated after SDF-1αstimulation, while lymphatic phenotypes such as Prox-1, podoplanin and lymphatic vessel endothelial hyaluronan receptor-1(LYVE-1), were dose-dependently up-regulated after SDF-1αstimulation.The changes of vWF, VEGFR2 and podoplanin, Prox-1, LYVE-1 expression after IL-1βstimulation was similar to that after SDF-1αwhile expression of VE-cadherin changed slightly .Conclusion SDF-1αand IL-1βare able to induce vascular endothelial cell expressing lymphatic phenotype .
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Objective To investigate the role of stromal cell-derived factor-1α(SDF-1α)/CXCR4 signal pathway in the therapeutic effects of hypoxic preconditioning endothelial progenitor cell (HEPC) transplantation on acute myocardial in-farction Methods Bone marrow endothelial progenitor cells (EPCs) were isolated from syngeneic adult male Wistar rats. EPCs were cultured under normoxic condition for 4 days and 1%O2+5%CO2+94%N2 condition for 3 days. The effect of HEP-Cs on the migration ability of 100μg/L SDF-1αwas observed. Western blot assay was used to detect the expression of CX-CR4, the solo receptor of SDF-1α on cells surface. Then, 26 syngeneic adult male Wistar rats were randomized into 3 groups:control group (n=8),EPCs group (n=9) and HEPCs group (n=9). The acute myocardium infarction animal model was established. At infarction, the rats received 5-points peri-infarct intramyocardial injections of PBS 200μL, 2×106 EPCs and 2 × 106 HEPCs. After 4 weeks, the haemodynamics parameters of cardiac function were analyzed by echocardiography. Results Compare with EPCs, the migration ability of HEPCs towards SDF-1α was increased significantly. The result of Western blot analysis showed an increased CXCR4 expression on the cell surface. After 4 weeks of transplantation, the left ventricular end systolic diameter and ejection fraction (EF%) were much improved in HEPCs group than those of EPCs group and control group (P＜0.05). Compare with control group, the left ventricular end-diastolic diameter was significantly im-proved in EPCs and HEPCs groups (P＜0.05). There was no significant difference in the improvement of the left ventricular end-diastolic diameter between HEPCs and EPCs groups (P>0.05). Conclusion SDF-1α/CXCR4 pathway was up-regu-lated by HEPCs, which showed the therapeutic effects via EPCs. The adjustment of SDF-1α/CXCR4 signaling pathway is an effective method for the treatment of ischemic heart diseases.
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Objective To investigate how SDF-1α and c-MYC protein regulates TACRl-Tr expression. Methods c-myc shRNA vector was constructed, small interfering RNA was employed for silencing c-myc gene in MCF-7 breast cancer cell. SDF-1α neutralized antibody was used in c-myc+ cell group and c-myc- cell group, while other c-myc+ cell group and c-myc- cells group were cultured under normal condition. The mRNA level of TACRl-Tr was determined by real-time PCR. Results c-myc shRNA vector was constructed successfully, in the normal presence of SDF-la, the level of TACRl-Tr mRNA in c-myc- cell group were lower than that in c-myc+ cell group( P < 0.05). But in the presence of SDF-la neutralized antibody, TACRl-Tr mRNA level of c-myc- cell group was higher than that of c-myc+ cell group(P < 0.05). Conclusion In the normal culture condition, c-MYC protein may transactivate TACRl-Tr transcription in MCF-7 cell, in the presence of SDF-1α neutral antibody, c-MYC protein lost the activity of transactivating for TACRl-Tr transciption.