ABSTRACT
Objective To investigate the effects of active vitamin D (VD) on the expression of triggering receptor expressed on myeloid cells-1 (TREM-1) in renal tissue of diabetic nephropathies (DN) rats and to explore the impact of TREM-1 on adhesion and migration capacity of macrophage.Methods DN rat models were established by streptozotocin.Rats were randomly distributed into four groups:control (NC) group,VD group,DN group and DN+VD group (DN rats with 0.1 μg · kg-1 · d-1 calcitriol by garages).Rats were sacrificed respectively at 8 weeks and 12 weeks after treatment.Pathological changes in kidney tissue were detected and the expressions of CD68 and TREM-1 were acquired by immunohistochemistry stain and Western blotting.In vitro,RAW264.7 cells were divided into NC group,VD group,high glucose (HG) group and HG+VD group.In HG+VD group rats were treated by high glucose with 10-8 mol/L 1,25(OH)2D3.TREM-1 expression was measured by immunohistochemistry stain and Western blotting,and the ability of macrophage in migration and adhesion was evaluated by Transwell migration assay and adhesion assay.TREM-1 siRNA was transferred to silence TREM-1 expression,while plasmid of TREM-1 was transferred for high expression.Their ability of adhesion and migration in macrophage and the effect of 1,25(OH)2D3 were examined.Results (1) Compared with the NC group,the expressions of CD68 and TREM-1 were increased in DN group (P ＜ 0.05),whereas markedly decreased in DN+VD group (P ＜ 0.05).(2) The number of adhesion and migration cells,and the expression of TREM-1 protein in macrophage were obviously increased in HG group as compared with those in NC group (all P ＜ 0.05);whereas above changes were markedly decreased in HG+VD group than those in HG group (P ＜ 0.05).(3) The number of adhesion and migrated macrophage was reduced after TREM-1 siRNA intervention (all P ＜ 0.05).VD could significantly decrease the effect of high glucose on adhesion and migrated macrophages after TREM-1 siRNA (all P ＜ 0.05).(4) Adhesion and migration of macrophage were increased via TREM-1 overexpression (all P ＜ 0.05),but the effects of VD on high glucose-induced adhesion and migration of macrophage were disappeared.Conclusions VD can suppress the adhesion and migration of macrophage via reducing the expression of TREM-1,and inhibit infiltration of macrophage in renal tissue of DN rats.
ABSTRACT
Objective To investigate the effect of macrophages on podocytes apoptosis in diabetic nephropathy. Methods Differentiated mouse macrophages (RAW264.7) were exposed to normal glucose, high glucose, then the conditioned media (CM) was collected and considered as NC-CM or HG-CM, respectively. Western blotting and immunofluorescent staining were used to detect the specific markers for M1 macrophages (iNOS) and M2 macrophages (MR). ELISA was used to detect the concentration of TNF-α in the CM. Then normal PRMI 1640 media (control), NC-CM or HG-CM was added to podocytes. In some experiments, ROS inhibitors (Tempo), p38 MAPK inhibitor (SB203580), anti-TNF-α neutralizing antibody, and IgG1 isotype control were respectively added to cells with HG-CM. Besides, recombinant mouse TNF-α alone was applied to incubate podocytes. Podocytes apoptosis was accessed by Annexin V-FITC/PI and Hoechst33342 staining. DCFH-DA staining was used to analyse ROS level. Western blotting was used to detect cleaved casepase-3, p38MAPK, and p-p38MAPK protein. Results Macrophages were activated when exposed to high glucose, displaying pro-inflammatory M1 polarization with higher iNOS and lower MR expression. HG-CM but not NC-CM trigged podocytes apoptosis, up-regulated ROS, cleaved casepase-3 and p-p38MAPK. However, the podocytes apoptosis trigged by HG-CM was abolished by either a ROS inhibitor (Tempo) or a p38 MAPK inhibitor (SB203580). Additionally, TNF-α was increased in the HG-CM. TNF-α protein in macrophage was aslo increased when exposed to high glucose. Anti-TNF-α neutralizing antibody blunted the apoptotic response, excess ROS generation and p-p38 MPAK expression in podocytes induced by HG-CM. Moreover, addition of recombinant TNF-α similarly led to podocytes apoptosis, increased ROS and p38 MPAK expression. Conclusion M1 macrophages activated by high glucose released TNF-α to promote podocytes apoptosis via ROS-p38 MAPK pathway.
ABSTRACT
Objective To investigate the effect of 1,25(OH)2D3 on high glucose induced podocyte injury and its signal transduction mechanism.Methods Differentiated mouse podocytes were exposed to normal glucose,high glucose,and different concentrations of 1,25(OH)2D3 or LY294002 (a selective PI3K inhibitor) for 24 h.PCR and immunofluorescent staining were used to detect nephrin,podocin,and desmin.Western blotting was used to detect protein expression of nephrin,podocin,desmin,PI3K,Akt and p-Akt.Results Compared with high glucose group,1,25(OH)2D3 (100 nmol/L and 1000 nmol/L) significantly up-regulated the expression of podocin and nephrin in podocytes induced by high glucose (P ＜ 0.05).Meanwhile,1,25(OH)2D3 (100 nmol/L) significantly reduced the expression of desmin (P ＜ 0.05).PI3K and p-Akt were obviously reduced in high glucose group.In the presence of 1,25(OH)2D3,the trends were reversed.However the above effects of 1,25(OH)2D3 were abolished when p-Akt was blocked by the PI3K inhibitor LY294002.Conclusions 1,25 (OH)2D3 can inhibit high glucose-induced pedocyte injury through PI3K/p-Akt signaling pathway.
ABSTRACT
Objective To observe the effect of scalp acupuncture and rehabilitation training on the regulation of neuro-plasticity-associated protein MAP-2 in gerbils modelling cerebral ischemia and reperfusion.Methods Cerebral ischemia and reperfusion were modelled into thirty-six male gerbils.They were then randomly divided into a model group (A),a scalp acupuncture and rehabilitation training group (B) and a rehabilitation training group (C),each of 12 cases.The scalp acupuncture and rehabilitation training were administered daily to the gerbils in group B beginning 24 h after modeling,for 14 d.Any changes in Bederson scores were observed after one,7 and 14 days.On the 14th day the expression of MAP-2 around the infarct focus was detected using western blotting in all 3 groups.Results On the 7th day the average Bederson score in group B (1.81 ± 0.52) was not significantly different from that in group A (2.13 ± 0.49) or group C (2.00 ± 0.31) (P ＞ 0.05).At the end of the treatment,however,there were significant differences between the groups,with group B (0.47 ± 0.31) scoring significantly better than groups C (1.04 ± 0.63) and A (1.46 ± 0.72) (P ＜ 0.05).Group C was also significantly better than group A (P ＜0.05).The expression of MAP-2 as measured as integrated optical intensity (IOD) in group B (0.91 ±0.18) was significantly higher than that in group A (0.43 ± 0.21) and group C (0.67 ± 0.24) (P ＜ 0.05) ; so was group C compared to group A (P ＜0.05).Conclusion The scalp acupuncture combined with rehabilitation training can improve the recovery of motor function and enhance the expression of neuro-plasticity-associated protein MAP-2 in gerbils with after cerebral ischemia and reperfusion.
ABSTRACT
Objective To investigate the effect of 1,25(OH)2D3 on high glucose induced macrophage activation and its underlying signal transduction mechanism.Methods RAW 264.7 cells were used to perform cell culture,the activity of intracellular iNOS was measured.VDR siRNA and PPARγ antagonist pre-treatment with macrophages were done before using 10-8 mol/L1,25(OH)2D3 to intervene high glucose pre-incubated macrophages.M1 markers including iNOS,TNF-α,IL-12,M2 markers including MR,Arg-1,IL-10 and nuclear receptors VDR and PPARγ were separately examined.Results The iNOS activity was increased in a glucose-dose and time dependent manner.Particularly,25 mmol/L glucose at 24 h gave the maximum response.After being treated with 25 mmol/L glucose for 24 h,not only inflammatory cytokines of TNF-α,IL-12 in the supernatant were increased,but quantitative real-time PCR and Western blotting analysis showed iNOS was also up-regulated (P ＜ 0.05).However,M2 markers,i.e.MR and Arg-l were significantly decreased (P ＜ 0.05).When in the presence of 1,25(OH),D3,the trends were reversed:the markers of M1,including TNF-α,IL-12 and iNOS were obviously reduced (P ＜ 0.05),while M2 markers,IL-10,Arg-1 and MR were increased (P ＜ 0.05).In addition,VDR and PPARγ were also increased (P ＜ 0.05).However,the above effects of 1,25 (OH)2D3 were abolished when further inhibited the expression of VDR and PPARγby VDR siRNA and PPARγ antagonist.Besides,accompanied by VDR,PPARγwas also decreased upon the treatment with VDR siRNA (P ＜ 0.05).Conclusion 1,25(OH)2D3 can promote high glucose induced classically activated macrophages (M1) converting to alternatively activated macrophages (M2) and this is achieved through VDR-PPARγ pathway.
ABSTRACT
Objective To investigate the effects and underlying mechanism of calcitriol on ameliorating podocytes impairment in DN rats.Methods SD rats were randomly divided into four groups:normal control (NC) group,calcitriol treatment (VD) group:calcitriol 0.1μg· kg--1 d-1,diabetic nephropathy (DN) group:streptozocin (STZ) 58 mg/kg,DN treated with calcitriol (DN + VD) group:calcitriol 0.1 μg · kg-1 · d-1 + STZ 58 mg/kg.Rats were sacrificed at the end of 18 weeks.Results Compared with the DN group,the DN + VD group exhibited significantly lower proteinuria by 36％,improved renal histology at the end of the experiment (P ＜ 0.05),and similar levels of blood glucose,serum urea nitrogen as well as body weight (P ＞ 0.05).There were no significant differences in the serum concentrations of creatinine,calcium and phosphorus among the four groups (P ＞ 0.05).In DN group,the expressions of nephrin,podocin,VDR,PI3K-p85 and p-Akt were significantly decreased and the expression of desmin was increased compared to NC group.Calcitriol treatment could attenuate the above changes.Additionally,a positive correlation was observed between the expressions of nephrin and VDR (r=0.776,P ＜ 0.05).Likewise,the expression of nephrin was positively correlated with either PI3K -p85 or p-Akt (r=-0.736,r=0.855,all P ＜ 0.05).Conclusion Calcitriol can ameliorate podocytes injury in DN rats,which might be related with the further up-regulation of PI3K/p-Akt signaling pathway.
ABSTRACT
Objective To investigate the effect of active vitamin D (VD) on macrophage M1 and M2 phenotype and its role in protecting podocyte impairment in diabetic nephropathy (DN).Methods Diabetes mellitus rats were established by intraperitoneal injection with streptozocin.Rats were randomly divided into four groups:normal-1 (NC-1,n=8),normal-2 (NC-2,n=8,normal rats treated with calcitriol 0.1 μg· kg-1 · d-1 by gavages),DN (n=24) and VD (n=24,DN+calcitriol 0.1 μg· kg-1 · d-1 by gavages).Blood glucose and body weight were assessed,and 24-hour urine was collected regularly.Blood and urine samples were taken for biochemical study,and kidney tissues were used for PAS staining to assess histological changes.Immunohistochemical staining was used to detect number of CD68 + macrophage.Western blotting was used to detect protein expressions of nephrin,podocin,CD68,M1 specific marker of inducible nitric oxide synthase (iNOS),TNF-α and M2 specific marker of CD163,arginase 1 (Arg-1),mannose receptor (MR).Results (1) In DN group,levels of BUN,Scr,urinary protein and glomerular mesangial matrix proliferation were significantly higher (P ＜ 0.05),and the expressions of nephrin,podocin were significantly decreased compared with NC groups (P ＜ 0.05).These above changes were significantly improved in VD group (P ＜ 0.05).(2)Number of CD68 + macrophage infiltration in DN group was increased in a time dependent manner compared with NC groups,which was significantly reduced in VD group (P ＜ 0.05).(3)To further definite M1 and M2 macrophage activation phenotype,the protein expressions of iNOS and TNF-α was increased in DN group at 8th,14th,18th weeks compared with NC groups (P ＜ 0.05),which were significantly decreased in VD group (P ＜ 0.05).Although,there were no significant difference of protein expressions of CD163,Arg-1 and MR between VD and DN group at both 8th and 14th week (P ＞ 0.05),the protein expressions of CD163,Arg-1 and MR were higher in VD group at 18th week than that in DN group (P ＜ 0.05),and the ratio of CD163/CD68 was also enhanced in VD group (P ＜0.05).(4)Moreover,the protein expression of iNOS was negatively correlated with expression of either nephrin or podocin (r =-0.707,P ＜ 0.01; r =-0.712,P ＜ 0.01),whereas the protein expression of CD163 was positively correlated with expression of either nephrin or podocin (r =0.627,P＜ 0.01; r=0.613,P ＜ 0.01).Conclusion Vitamin D can regulate macrophage phenotype,via inhibiting M 1 macrophage activation and enhancing M2 macrophage activation to protect podocyte impairment.