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Background and Purpose: tubulointerstitial damage is a common pathway for a variety of end-stage renal disease, is closely related to the severity and prognosis of chronic kidney disease. Tubulointerstitial damage interstitial inflammatory cell infiltration as the main feature, the particular infiltration and activation of T cells, macrophages are the most critical. These inflammatory cells through the secretion of inflammatory cytokines can activate local inflammatory response, and thus caused tubulointerstitial damage and fibrosis. Effectively reduce renal interstitial inflammation and fibrosis reaction, has a particularly important significance to slow kidney disease to end-stage renal disease. Costimulatory molecules are a class of cell surface molecules, respectively to provide the necessary auxiliary signal to the T, B cell activation, thereby regulating cell proliferation, activation and differentiation. The experimental study of kidney disease in recent years, through the inhibition of CD28, CD40, and ICOS costimulatory pathways indirect induction of the incompetence of effector T cells, in order to achieve the purpose of reducing renal tissue injury, has achieved a certain effect. Also known as complement receptor Ig superfamily molecule (Complement receptor of the immunoglobulin the superfamily CRIg) of VSIG4 (V-set and immunoglobulin domain-containing protein 4), or Ig superfamily protein -39 the (Ig the superfamily protein 39, Z39Ig), as type I transmembrane molecules, has an important regulatory role of the B7 family of costimulatory molecules is a newly identified on T cell activation and survival. VSIG4 mainly expressed in the cells of the monocyte-derived macrophages in the monocyte macrophages adult humans mainly distributed organizations, such as the liver, lungs, etc. have VSIG4mRNA the expression. Recent studies have shown that, VSIG4 cross linking its unknown receptor molecule to inhibit T cell activation play a total inhibition of the function of the molecule ligands. Early nephropathy in patients with renal biopsy specimens found in varying degrees in all specimens infiltration of T cells, the T cell is surrounded by rich macrophages; macrophage-specific expression of the group VSIG4 and VSIG4 mainly expressed in the tubule matter damage light area. We speculated the macrophages expressed VSIG4 play the role of costimulatory molecule ligands not yet known by the T cell surface receptors inhibit T cell activation, T-cell inflammatory cytokine secretion, reduce the activation of T cells to neighboring cells , thereby improving renal interstitial inflammation and fibrosis of the pathological process. This test is intended using VSIG4 gene knock unilateral ureteral obstruction (Unilateral ureteral occlusion, UUO) model, in addition to (VSIG4 - / - ) mice and VSIG / mice two sets of the tubulointerstitial injury severity and in vivo T cell, macrophage function differences, and to explore the therapeutic effect and mechanism of VSIG4 tubulointerstitial injury. Looking for new ideas for the prevention and treatment of renal interstitial inflammation and fibrosis. Methods: SPF grade male C57B6 (VSIG4 - / - and VSIG4 / ) mice were 40, which VSIG4 - / - group, VSIG4 / 20 mice, two groups of mice were left ureteral ligation, unilateral ureteral obstruction (Unilateral ureteral occlusion, UUO) model, and in the sham-operated group, postoperative 3, 7, and 14 days to take the left kidney of mice (each time point, each of the five mice in the control group laparotomy without ligation) HE staining of the left renal tubular injury and interstitial inflammatory cell infiltration, biochemical indicators detection of the mice serum creatinine, blood urea nitrogen, immunohistochemical observation of renal tissue transforming growth factor-β1 (Transforming growth factor-β1, TGF-β1), matrix metalloproteinase-2 (Matrix metalloproteinase 2, MMP-2), CD3 T cells CD68 macrophages, immunofluorescence observed CD3, CD4 and CD8 T cells change, Real-time PCR observe interleukin -2 (Interleukin-2, IL-2) and tumor necrosis factor-α (Tumour necrosis factor-α, TNF-α), γ-interferon (Interleukin-γ, IFN-gamma), interleukin -10 (Interleukin-10, IL-10), the expression of the difference between groups, and statistically analyzed. Results: 1. The reference Priraini method, lesions of the renal tubules and renal interstitial Rating: light microscope by counting measurement the HE staining obstruction tubular interstitial lesions: VSIG4 / group : the kidneys of mice in the control group, no significant change; 3 days after the obstructed kidney see section vacuolar degeneration of tubular epithelial cells, a small amount of tubular mild expansion, interstitial less inflammatory cell infiltration, extent of disease (18.71 ± 2.21)% tubulointerstitial mild lesions; seven days after tubular dilatation is more pronounced, more inflammatory cells in the renal interstitial infiltration, interstitial width significantly increased, occasionally atrophy tubular, extent of disease (30.06 ± 3.68)%, tubulo quality moderate lesions; After 14 days, see diffuse tubular basement membrane thickening of the the shrunken cortex and outer medulla more tubular atrophy, and a large number of inflammatory cell infiltration, fibrosis obvious, extent of disease (53.49 ± 3.65)%, the tubulointerstitial severe lesions gradually increased (p lt; 0.05); extension of renal interstitial inflammatory cell infiltration and tubular damage with the time of obstruction. : Control mouse kidney VSIG4 - / - group had no significant change; obstructed kidneys after 3 days to see part of the tubular mild expansion, interstitial inflammatory cell infiltration, extent of disease (30.47 ± 2.14)% tubulointerstitial moderate lesions; 7 days after the tubular remarkable expansion, renal interstitial more inflammatory cell infiltration, interstitial gap significantly widened, showing little atrophy tubular, extent of disease (43.48 ± 2.93)% tubule quality of severe lesions; 14 days after see more tubular atrophy, infiltration of inflammatory cells, fibroblasts significantly more pronounced fibrosis, extent of disease (62.06 ± 2.15)%, the tubulointerstitial severe lesions; with the obstruction Time to extend renal interstitial inflammatory cell infiltration and tubular damage also gradually increased (p lt; 0.05). VSIG4 - / - the interstitial inflammation renal cell infiltration and tubular damage than the same period VSIG4 / group (p lt; 0.05). The of postoperative VSIG4 / group serum creatinine, blood urea nitrogen, a transient increase (p lt; 0.05) appears in 14d after fall, and were within normal range; VSIG4 - / - 7 days postoperative serum creatinine, urea nitrogen, a transient increase (p lt; 0.05), fall in postoperative 14d, are in addition to the 7 days after urea nitrogen slightly above normal normal range. The two groups showed no significant difference. 3 Immunohistochemical detection of TGF-β1, MMP-2, results showed: VSIG4 / group was extended with a time of obstruction gradual increase in TGF-β1 expression (p lt; 0.05) of; VSIG4 - / - group of TGF-β1 expression also gradually increased with the time extension of the obstruction; compared with VSIG4 / , VSIG4 - / - group postoperative phase time points TGF-β1 expression more (p lt; 0.05). MMP-2 in VSIG4 / group after three days to reach the peak, then decreases with the time of obstruction (p lt; 0.05); VSIG4 - / - group expression trends the same VSIG4 / group, and the postoperative phase at the same time the phase points VSIG4 - / - Group MMP-2 expression of than VSIG4 / group lowered (p lt ; 0.05). 4, Realtime PCR detection of IL-2, IFN-γ, IL-10, of TNF-α (157bp, 205bp, 158bp, 202bp). The results showed that: ① of IL-2 mRNA in VSIG4 / group the postoperative expression levels increased (p lt; 0.05) expression reached its peak after 14 days; VSIG4 - / - group after expression levels also increased (p lt; 0.05), reached a peak after 14 days. VSIG4 - / - of IL-2 expression after 3 days, 14 days than VSIG4 / group relative to the same point increased expression. ② IFN-γmRNA VSIG4 - / - and VSIG4 / group the postoperative renal tissue were expressed after 7 days, 14 days VSIG4 / group expression of IFN-γ than 3 days after a significant increase (p lt; 0.01); 7 days after than 14 days VSIG4 - / - Group IFN-γ expression after 3 days increase (p lt; 0.05). After VSIG4 - / - group IFN-γ expression than VSIG4 / group the same phase point expression increased significantly (p lt; 0.01). ③ IL-10 mRNA in VSIG4 / in renal tissue was gradually extended with the time of obstruction increased (p lt; 0.05), IL-after the same group in VSIG4 - / - 10 extended with the time of obstruction expression also gradually increase (p lt; 0.01). IL-10 mRNA expression in VSIG4 - / - group was 14 days compared with VSIG4 / group relative to the same point expression was significantly decreased. ④ TNF-αmRNA VSIG4 / group after three days in the renal tissue expression of the control group had no significant difference (p gt; 0.05), seven days after the expression began to increase; in VSIG4 - / - group expression of TNF-α with the obstruction time and gradually increase (p lt; 0.05). VSIG4 - / - of TNF-α after 7 days, 14 days expression than VSIG4 / group expression increased during the same period (p lt; 0.05). Immunofluorescence test results show: postoperative renal tissue VSIG4 / CD3, CD4, CD8 T cells were extended expression gradually increased with the time of obstruction; VSIG4 - / - group expressed the trend with VSIG4 / group postoperatively; However, in expression compared to the same period VSIG4 / VSIG4 - / - group after group upregulation . Immunohistochemical detection results: VSIG4 / CD68 macrophages postoperative extended with the time of obstruction increased expression after 7 days and reached the peak in VSIG4 - / - group expressed the same trend, but VSIG4 - / - group after expression with the same period VSIG4 / group express no statistically significant differences. Conclusion: 1. Experiment successfully prepared VSIG4 / and VSIG4 - / - mouse model of unilateral ureteral obstruction. 2. VSIG4 - / - group mice postoperative renal interstitial inflammation cell infiltration and the tubule damage important than VSIG4 / mice. The prompted VSIG4 unilateral ureteral obstruction mice renal interstitial inflammation reaction and renal interstitial fibrosis can be suppressed. 3 TGF-β1 in renal tissue VSIG4 / expression to extend progressively increased with the time of obstruction; expression of MMP-2, reached the peak after 3 days, then gradually decreased; IL-2, IFN- γ, IL-10, TNF-α expression after surgery were increased. - / - in renal tissue VSIG4 postoperative these indicators change more obvious. Tip VSIG4 inhibit macrophage-mediated renal tubular interstitial inflammatory response. 4. VSIG4 inhibition of renal tissue CD3 of to CD4 CD8 T cells infiltrating the sites of inflammation, inhibition of T cells to secrete IL-2 and IFN -γ; but no obvious effect on macrophage infiltration. Suggesting that VSIG4 may be suppressed by inducing T cell anergy tubulointerstitial inflammation and fibrosis.
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