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Objective:To investigate the effect of interleukin (IL)-7 receptor α (IL-7Rα) antibody on the immune inflammation and renal injury in MRL/lpr lupus mice.Methods:Fifteen 3-4-week-old female MRL/lpr lupus mice (specific pathogen free) weighing 15-16 g were bred to 14-week-old and randomly divided into three groups: IL-7Rα antibody intervention group, isotype antibody (positive control) group and normal saline (negative control) group. The mice in the threc groups were intraperitoneally injected with IL-7Rα antibody, isotype antibody and normal saline respectively, with 100 μg three times a week for 4 weeks. At the age of 18-week old, the mice were sacrificed. Twenty-four-hour urinary protein was detected by Coomassie brilliant blue method, serum creatinine was detected by peroxidase method, and the expression of autoantibody (anti-double strand DNA antibody) and inflammatory factors such as tumor necrosis factor-α (TNF-α), interferon-γ (IFN-γ) and IL-21 was detected by enzyme-linked immunosorbent assay method. Renal pathology was detected by PAS and Sirius red staining, and CD3 and F4/80 in renal tissues were detected by immunohistochemistry method. Regulatory T cells, follicullar helper T cells (Tfh) and follicular regulatory T cells (Tfr) were detected by flow cytometry.Results:The 24-hour urinary protein, serum creatinine, serum anti-double strand DNA antibody and serum IFN-γ and IL-21 in the IL-7Rα antibody intervention group were significantly lower than those in the control groups (all P<0.01). However, there was no significant difference in serum TNF-α among the three groups ( F=0.39, P>0.05). The positive infiltrating cells of CD3 and F4/F80, and the ratio of type Ⅰ/Ⅲ collagen fibers ( F=41.11, P<0.01) of renal tissues in the IL-7Rα antibody intervention group were lower than those in the other two groups. Compared with the control groups, the ratio of regulatory T cells (CD4 +CD25 +Foxp3 +)/effector T cells (CD4 +CD25 +) in blood of IL-7Rα antibody intervention group increased ( F=21.64, P<0.01), while the ratio of Tfr (CD4 +CXCR5 +Foxp3 +)/Tfh (CD4 +CXCR5 +) in peripheral blood and spleen increased ( F=38.95, P<0.01; F=12.90, P<0.01). Conclusion:IL-7Rα antibody can reduce the production of autoantibodies such as anti-double strand DNA antibody and inflammatory factors by increasing the ratio of regulatory T cells and Tfr/Tfh, thus alleviating immune inflammation and renal damage in MRL/lpr lupus mice.
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Objective To investigate the effects and underlying mechanism of the scavenger receptor CD36 in high glucose-induced rat glomerular mesangial cells apoptosis.Methods The mesangial cells of rats were divided into 4 groups:control group (5.6 mmol/L glucose),mannitol group (24.2 mmol/L mannitol+5.6 mmo]/L glucose),high glucose group (30 mmol/L glucose),CD36 monoantibody group (30 mmol/L glucose+CD36 mono-antibody).The intracellular ROS level was detected by confocal microscopy with fluorescent probe CM-H2DCFDA.MDA,GSH-PX,8-OHDGA in cell supernatant were detected.Apoptosis was determined by flow cytometry followed by Annexin V-FITC/PI double stains.The expression of CD36,Bax and Bcl-2 were detected by RT-PCR and Western blotting.Results The expression of CD36 was detected in glomerular mesangial cells.The highest level was found in high glucose group in 24 hours.There was no significant difference found between control group and mannitol group with respect to intracellular ROS generation,MDA,8-OHDG,GSH-PX level,apoptosis rate,expression of CD36,Bax and Bcl-2 (all P ＞ 0.05).There was no significant difference in the expression of CD36 between CD36 mono-antibody group and high glucose group (P ＞ 0.05).Compared to control group,the intracellular ROS generation,MDA and 8-OHDG levels,apoptosis rate,the expression of CD36 and Bax were significantly increased,the GSH-PX level and the expression of Bcl-2 were significantly lower in high glucose group (all P ＜ 0.05).Compared to the high glucose group,the intracellular ROS generation,MDA and 8-OHDG levels,apoptosis rate,the expression of Bax were suppressed but the GSH-PX level and the expression of Bcl-2 increased in CD36 mono-antibody group (all P ＜ 0.05).The intracellular ROS level was positively correlated with apoptosis rate,protein expression of CD36 and Bax gene,was negatively correlated with Bcl-2 protein expression.Conclusions CD36 was involved in the high glucose induced apoptosis of mesangial cells which was potentially mediated by an increased level of oxidative stress.
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Objective To investigate the renoprotective effect of erythropoietin(EPO) in streptozotocin-induced diabetic rats and to explore the possible mechanism.Methods The SD rats were randomly divided into there groups: normal control rats, diabetic, diabetic treated with EPO(NC, DM, DE groups).The rats were sacrificed after 8 weeks treatment.Renal morphology was observed by light microscopy.The expression of erythropoietin receptor(EPOR) in kidney was detected by immunofluorescence and Western blotting.The expression of p47phox, transforming growthfactor (TGF)β1andfibronectin (FN)proteininkidneywasdetectedby immunohistochemistry and Western blotting.The activity of antioxidants including total antioxidant capacity (T-AOC), superoxide dismutase (SOD), glutathione peroxidase (GSH-Px) and the level of malondialdehyde(MDA) in kidney were also measured.Results EPO treatment notably attenuated renal pathologic and functional changes.The expression of EPOR was found in kidney,but there was no difference among groups(P＞0.05).Compared with normal rats, diabetic rats showed an elevated expression of p47phox, TGF-β1, FN proteins and MDA levels in kidney as well as reduced activities of SOD, GSH-Px and T-AOC (all P＜0.01).Compared with diabetic rats, EPO could decrease the protein expression of p47phox,TGF-β1and FN in kidney (all P＜0.05).Meanwhile, elevated MDA level in the kidney was decreased as well as decreased SOD, GSH-Px,T-AOC activities were significantly remitted in DE group(all P＜0.01).Conclusion EPO can amelioraterenaldamagevia theinhibition of oxidativestressandTGF-β1andFNprotein expression in streptozotocin-induced diabetic rats.
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Objective To investigate whether erythropoietin (EPO) can inhibit the proapoptotic effect of high glucose on rat proximal tubular epithelial cells, and the possible mechanisms in which EPO exerts its anti-apoptotic role. Methods Rat proximal tubular epithelial cells (NRK-52E) were divided into 5 groups: normal control group, osmolarity control group, high glucose group, high glucose with EPO (50 U/ml) group and high glucose with EPO (100 U/ml) group. The expression of EPO receptor (EPOR) in NRK-52E cells was examined by immunocytochemistry. The effect of high glucose on the expression of EPOR was detected by Western blotting. The rate of apoptosis was evaluated by flow cytometry Annexin V-FITC/PI double stains. The intracellular ROS was detected using fluorescent probe CM-H2DCFDA. The expression of bcl-2, bax and caspase-3 mRNA were examined by RT-PCR. Results The expression of EPOR was demonstrated in NRK-52E cells, and high glucose could up-regulate the expression of EPOR. High glucose could induce oxidative stress in NRK-52E cells, and up-regulate the mRNA expression of bax and caspase-3, down-regulate the mRNA expression of bcl-2. These effects of high glucose on NRK-52E cells could be reversed by EPO. Conclusion EPO inhibits NRK-52E cells apoptosis induced by high glucose through attenuating oxidative stress,up-regulating theexpression of bcl-2 mRNA and down-regulating the expression of bax and caspase-3 mRNA, which may be mediated by EPOR.