肾小管间质纤维化与单核巨噬细胞的关系

目的：探讨肾小管间质纤维化与单核巨噬细胞(MC／MP)的关系。方法：结扎大鼠一侧肾静脉，连续饲养25d，制作大鼠肾小管间质纤维化模型。每5天杀检取材。HE、PAS、PASM、Masson等染色方法观察MC／MP的聚集和肾小管间质纤维化病变；免疫组化和双重免疫组化观察。肾间质MC／MP的聚集与增生；原位杂交、免疫组化观察单核细胞化学吸引蛋白质1(MCP-1)、巨噬细胞集落刺激因子(M-CSF)在肾内的表达分布。Western blot检测病变肾脏MCP-1的表达。对不同时间点。肾小管变性、肾小管间质纤维化程度、肾间质MC／MP聚集的数量及其中的增生比例、MCP-1和M-CSF的表达进行评估分析。结果：肾静脉结扎侧表现为。肾小管变性萎缩、间质中MC／MP浸润、细胞外基质沉积等肾小管间质纤维化的典型病变。病变早期肾间质中有明显的MC／MP聚集。后期减少。表达增殖细胞核抗原(proliferating cell nuclear antigen，PCNA)的单核细胞占一定比例，单核细胞的增生比例与聚集高度相关。原位杂交、免疫组化和Western blot显示，病变肾组织中MCP-1、M-CSF mRNA的表达主要位于变性的。肾小管上皮细胞胞浆中，病变早期强，后期减弱。肾小管上皮细胞MCP-1和M-CSF的表达与肾间质MC／MP的聚集高度相关。肾间质MC／MP的聚集与肾小管变性高度相关。结论：肾小管间质纤维化早期，间质中有明显的MC／MP聚集，来源于浸润和局部增生。肾小管上皮细胞通过表达MCP-1、M-CSF在MC／MP浸润和增生中起了重要的调控作用。肾间质MC／MP的聚集与肾小管变性高度相关。MC／MP通过分泌多种细胞因子和促增殖因子促进。肾小管间质纤维化，并进一步损伤肾小管。

Relationship between tubulointerstitial fibrosis and mononuclear-macrophage

OBJECTIVE: To study the relationship between monocyte/macrophage (MC/MP) accumulation and tubulointerstitial fibrosis. METHODS: The renal tubulointerstitial fibrosis model in Wistar rats was established by unilateral renal vein ligature. The rats were fed for 25 days. The kidneys were obtained every 5 days by killing the rats. The morphological changes of tubulointerstitial fibrosis were observed by light microscopy with HE, PAS, PASM and Masson staining. Immunohistochemistry and double immunohistochemistry were used to observe MC/MP accumulation and proliferation. In situ hybridization and immunochemistry were used to observe MCP-1 and M-CSF expression in experimental renal tissue. The MCP-1 protein expression was inspected by Western blot. All the data were analyzed statistically. RESULTS: The pathological changes of tubulointerstitial fibrosis were typical. There were many MC/MPs accumulsated in the interstitial space at the early stage and some of them were PCNA positive. At the late stage both accumulation and proliferation of MC/MPs were decreased. The portion of monocyte proliferation was high correlated with the MC/MP accumulation. In situ hybridization showed the positive signals of MCP-1 and M-CSF were mainly located in the cytoplasm of degenerated tubular epithelium and they were strong at the early stage, weak at the late stage. MCP-1 by immunochemistry and Western blot were consistent with in situ hybridization. The MC/MP accumulation was high correlated with the expression of MCP-1 and tubular epithelium degeneration. The portion of monocyte proliferation was high correlated with the expression of M-CSF. CONCLUSION: There was obvious accumulation of MC/MP at the early stage of tubulointerstitial fibrosis. The accumulation came from infiltration and proliferation which were regulated by degenerated tubular epithelial cells producing MCP-1 and M-CSF. MC/MP accumulation was highly correlated with tubular degeneration. MC/MP promoted tubulointerstitial fibrosis and damaged tubular epithelium by secreting a variety of cytokines.