M2型巨噬细胞在衰老上皮细胞诱导良性前列腺增生间质纤维样改变中的机制研究

Benign prostatic hyperplasia (BPH) is an extremely common urological disease of older men, and its development is regarded as a respect of the organism aging process. In our earlier studies, we found that the senescent prostatic epithelial cells were prevalent, the macrophage infiltration increased and stromal become fibrosis-related alteration in the BPH tissue. These histological features were especially evident in the early-onset BPH (age < 50 years old) patients. Therefore, we hypothesized that senescent prostatic epithelial cells might induce infiltration and differentiation of macrophages, then activating TGF-β1 and IL-4 signaling to mediated myofibroblasts phenoconversion and promoting rapid progression of BPH. In this project, first, we will investigate the molecular mechanism of senescence prostatic epithelial cells derived senescence- associated secretory phenotype (SASP) inducing the infiltration and differentiation of macrophages. Then we will uncover the signaling mechanism by which infiltrating macrophages inducing prostate fibroblasts to myofibroblast phenotypes. The project will elucidate the molecular signaling mechanism of macrophages in the process of senescent epithelial cells inducing stromal fibrosis-ralated disease in BPH. It might provide a new theoretical basis of dealing with BPH progression.

良性前列腺增生(BPH)是老年男性常见病，其发生发展被看作是机体老化的表现之一。 我们前期发现，BPH组织中普遍存在衰老的前列腺上皮细胞，组织中巨噬细胞浸润增多，间质呈现纤维样改变，这种组织学特征在早期进展性BPH（年龄<50岁）患者尤为明显；衰老细胞能分泌衰老相关分泌表型(SASP)趋化免疫细胞，M2型巨噬细胞能诱导肌成纤维细胞表型转化。 所以我们提出假设：衰老的前列腺上皮细胞能通过趋化和诱导分化M2型巨噬细胞，继而激活相关下游信号诱导肌成纤维细胞发生表型转化，促进BPH快速进展。本课题拟探讨1）衰老前列腺上皮细胞趋化和诱导分化巨噬细胞的SASP及其分子生物学机制；2）M2型巨噬细胞诱导前列腺成纤维细胞发生肌成纤维细胞表型转化的信号调控机制。本课题拟阐明M2型巨噬细胞在衰老上皮细胞诱导BPH间质纤维样改变过程中的分子信号机制，为临床控制BPH进展提供新的理论依据。

BPH(良性前列腺增生)是一种以上皮和间质增生为主，严重影响老年男性生活质量的疾病。随着年龄增加，衰老的前列腺上皮细胞可以通过分泌衰老相关表型促进BPH的进展。60例BPH患者冰冻切片中，约30%患者可观察到SA-β-gal（β-半乳糖苷酶）染色呈现阳性，阳性细胞主要位于上皮细胞，间质细胞则无明显染色。18例SA-β-gal染色阳性患者的冰冻切片分析，整圈，半圈，四分之一圈阳性的比例分别是13.2%±11.7%、5.9%±2.9%、6.5%±3.5%。通过100ng/ml阿霉素诱导人前列腺上皮细胞系BPH-1和PWR-1E成衰老细胞，其细胞形态表现为细胞体积增大，且SA-β-gal表达阳性，p21蛋白表达增高。流式细胞术检测阿霉素诱导后的BPH-1和PWR-1E的SA-β-gal染色阳性率分别为93.5%±1.0%，98.7%±0.8%。多因子筛查显示在衰老BPH-1和PWR-1E的培养基中IL-15等明显上升。CCK8，流式检测周期显示阿霉素诱导后的衰老BPH-1和PWR-1E的条件培养基可以显著促进WPMY-1和PrSC的生长，以及S期和G2/M期的细胞的比值，外源性加入IL-15能够促进前列腺间质细胞(WPMY-1和PrSC)的生长，而IL-15中和抗体可以抑制这种增殖的效应。BPH组织连续切片显示，衰老的前列腺上皮细胞腺腔周围IL-15的表达高于未衰老的上皮腺腔。最后通过western blot实验检测JAK/STAT3、JAK/STAT5信号通路分析发现，IL-15能够促进间质细胞STAT3蛋白通路的磷酸化。本研究结果显示，大约30%的前列腺组织内存在衰老细胞，衰老细胞主要分布在前列腺上皮，间质很少。衰老的上皮细胞及其分泌的IL-15能够刺激周围的间质细胞增殖：JAK/STAT3可能参与了这一过程。