| Abstract: | Objective To investigate the effect of suppressor of cytokine signaling 3 (SOCS3) on the proliferation of human mesangial cells stimulated by aggregated IgA1 (aIgA1) from patients with IgA nephropathy(IgAN), and explore its possible mechanism. Methods Serum monomeric IgA1 was isolated with jacalin affinity and Sephacryl S-200 HR chromatography from IgAN patients, and then heated to aggregated form (aIgA1). Human glomerular mesangial cells(HMC) were transfected with Adv-SOCS3-IRES2-EGFP for 48 hours, and incubated with aIgA1 for 12-48 h. The cells were divided into blank control group, IgA1 group, IgA1+Adv-EGFP group and IgA1+Adv-SOCS3-IRES2-EGFP group. The mesangial cell proliferation was observed through MTT, and the levels of SOCS3, TLR4, TGF-β1 protein and mRNA were detected through Western blotting and real-time PCR. Results HMC proliferation was promoted significantly after IgA1 stimulated at 24 h. Compared with control group, the protein and mRNA expression of SOCS3, TLR4, TGF-β1 were significantly increased in IgA1 group (P＜0.05). Compared with IgA1 group and IgA1+Adv-EGFP group, MTT absorbency was obviously reduced after incubation with aIgA1 for 24 h and 48 h in IgA+Adv-SOCS3-IRES2-EGFP group, and the protein and mRNA expression of TLR4 and TGF-β1 were significantly decreased in IgA1+Adv-SOCS3-EGFP group (P＜0.05). Conclusion Over-expression of SOCS3 may inhibit the proliferation of HMC stimulated by aIgA1, partly through down-regulating the expression of TLR4 and TGF-β1. |
