年龄相关钙蛋白酶2上调C499促进前列腺间质细胞增生导致前列腺增生的发生机制

Calpain 2 up-regulate C499 in the prostatic stroma and promotes the proliferation of interstitial cells,leading to the occurrence of BPH

目的探讨前列腺增生(BPH)的发病机制。我们前期发现塌陷反应调节蛋白4(CRMP4)受前列腺组织内钙调蛋白2切割产生两个片段,其中N端产物为C499(1-498aa),C499进入细胞核作用E2F1促进细胞增殖。我们认为C499上升促进前列腺间质细胞增生导致BPH的发生。方法收集BPH病例按年龄建立队列。分别做CD86+M1巨噬细胞、钙蛋白酶2、C499、CRMP4的免疫组化(IHC),评估CD86+M1巨噬细胞、钙蛋白酶2与C499表达与年龄和BPH间质组织增生的联系。C499基因质粒转染RWPE-1细胞,观察细胞增殖。结果在60例BPH患者各年龄组,IHC检测显示CD86+M1巨噬细胞、钙蛋白酶2、C499在前列腺间质表达,随年龄增长而升高;而前列腺上皮细胞内CRMP4表达随年龄增加而逐渐减少。CCK-8实验显示C499促进RWPE-1生长。结论随着年龄增长,BPH患者前列腺间质细胞CD86+M1巨噬细胞增加,激活钙蛋白酶2活性;切割因上皮间质细胞转化至前列腺间质细胞的CRMP4,促使C499在前列腺间质表达升高,C499促进前列腺间质细胞增殖,导致BPH的发生。

Objective To explore the pathogenesis of benign prostatic hyperplasia(BPH).Previously we found that C499(1-498aa),the N-terminal product of collapsin response mediator protein 4(CRMP4),increases with age.Basically,C499 enters the nucleus and binds with promoter of E2F1 to promote cell proliferation.Accordingly,we believe that the accumulation of C499 promotes prostatic stromal cell proliferation and leads to the occurrence of BPH.Methods 60 patients with BPH were enrolled to establish a cohort by age.Immunohistochemistry(IHC)of M1 macrophages,calpain 2,C499,and CRMP4 were respectively performed to evaluate the number of M1 macrophages,the expression status of calpain 2 and C499 in BPH paraffin samples in accordance with aging and stromal cell proliferation in patients with BPH.In addition,The C499 gene plasmid was transfected into RWPE-1 cells,and the cell proliferation was observed.Results 60 patients were divided into 4 group according with age(50~,60~,70~,80~.In each group,IHC analysis showed that the number of M1 macrophages increased in the prostatic interstitium with age;calpain 2 was expressed in prostatic interstitial cells and elevated with age;C499 was mainly expressed in the prostatic stromal was up-regulated with age whereas CRMP4 in epithelial cell was reduced along with age.The CCK-8 experiment showed that C499 promoted the growth of RWPE-1.Conclusion With age increases,M1 type macrophages in prostate mesenchymal cells in BPH patients was gradually accumulated and thus activated calpain 2 activity.Given epithelial-mesenchymal transition is evolutionary processed with age in BPH,CRMP4 in prostate epithelial cells was moved to prostate stromal and cleaved by calpain 2.Accumulation of C499 in prostatic stromal stimulated to proliferation of stromal cells,leading to the occurrence of BPH.