人肝脏贮脂细胞中血小板衍生生长因子分泌及基因表达的调控

Regulation of platelet-derived growth factor secretion and gene expression in human liver fat-storing cells.

作者信息

Marra F, Choudhury G G, Pinzani M, Abboud H E

机构信息

Department of Medicine, University of Texas Health Science Center at San Antonio.

出版信息

Gastroenterology. 1994 Oct;107(4):1110-7. doi: 10.1016/0016-5085(94)90236-4.

DOI:10.1016/0016-5085(94)90236-4

PMID:7926460

Abstract

BACKGROUND/AIMS: Liver fat-storing cells (FSCs) actively proliferate and secrete extracellular matrix during liver injury. Platelet-derived growth factor (PDGF) is a potent mitogen for cultured FSCs. In the present study, we investigated the regulation of PDGF gene expression and production in cultured human liver FSCs.

METHODS

PDGF A-chain and B-chain expression was analyzed by Northern blotting and ribonuclease protection assay, respectively. Secretion of PDGF was evaluated by immunoprecipitation and immunoblotting of conditioned medium and metabolic labeling of FSC followed by immunoprecipitation.

RESULTS

Three PDGF A-chain transcripts were detectable. Stimulation of FSC with phorbol myristate acetate (10(-7) mol/L) or PDGF BB (20 ng/mL) increased steady-state levels of PDGF A-chain and B-chain messenger RNA. PDGF AA had a small stimulatory effect on A-chain but not B-chain messenger RNA levels. FSCs secrete PDGF in the conditioned medium. The secreted protein is bioactive, because concentrated conditioned medium induced an increase in thymidine incorporation that was inhibited by anti-PDGF antibodies.

CONCLUSIONS

This study shows that cultured FSCs express PDGF A- and B-chain genes and release bioactive PDGF in the culture medium. These data raise the possibility of an autocrine or short-loop paracrine effect of PDGF in FSCs as a mechanism contributing to the maintenance of the proliferative state during liver injury.

摘要

背景/目的：肝贮脂细胞（FSCs）在肝损伤时会活跃增殖并分泌细胞外基质。血小板衍生生长因子（PDGF）是培养的FSCs的一种强效促有丝分裂原。在本研究中，我们调查了培养的人肝FSCs中PDGF基因表达和产生的调控情况。

方法

分别通过Northern印迹法和核糖核酸酶保护试验分析PDGF A链和B链的表达。通过对条件培养基进行免疫沉淀和免疫印迹以及对FSC进行代谢标记后再进行免疫沉淀来评估PDGF的分泌。

结果

可检测到三种PDGF A链转录本。用佛波醇肉豆蔻酸酯乙酸盐（10⁻⁷mol/L）或PDGF BB（20 ng/mL）刺激FSC可增加PDGF A链和B链信使核糖核酸的稳态水平。PDGF AA对A链信使核糖核酸水平有轻微刺激作用，但对B链信使核糖核酸水平无刺激作用。FSCs在条件培养基中分泌PDGF。分泌的蛋白具有生物活性，因为浓缩的条件培养基可诱导胸苷掺入增加，而这种增加可被抗PDGF抗体抑制。