糖基化终产物影响成骨细胞的生长和功能。

Advanced glycation end products affect growth and function of osteoblasts.

机构信息

Department Internal Medicine III, Hand and Reconstructive Surgery, Jena University Hospital, Germany.

出版信息

Clin Exp Rheumatol. 2011 Jul-Aug;29(4):650-60. Epub 2011 Aug 31.

PMID:21906430

Abstract

OBJECTIVES

Advanced glycation end products (AGEs) have been implicated in the pathogenesis of bone-destructive disorders. Yet reports on the influence of AGEs on human osteoblasts remain lacking. The aim of the study is to investigate the influence of AGE-modified bovine serum albumin (AGE-BSA) on cell growth and expression of osteoblastic markers associated with osteogenesis and osteoclastogenesis.

METHODS

Human osteoblasts established from bone tissue specimens were stimulated with AGE-BSA and investigated in vitro. Expression of mRNA for the receptor for AGEs (RAGE), nuclear factor kappa B subunit p65 (NFκB p65), tumour necrosis factor alpha (TNF-α), matrix metallo proteinase-1 (MMP-1), receptor activator of NFκB ligand (RANKL), osteoprotegerin, collagen type I (Col1), osteocalcin (OC) and alkaline phosphatase (ALP) were measured using real-time polymerase chain reaction (PCR). Respective protein expressions were evaluated by western blot analysis or ELISA. NFκB activation was investigated by luciferase assay and electrophoretic mobility shift assay (EMSA). Cell cycle analysis, cell proliferation and markers of necrosis and early apoptosis were assessed.

RESULTS

AGE-BSA was actively taken up into osteoblasts and induced cell cycle arrest and an increase in necrotic, but not apoptotic cells. The increased expression of RAGE and TNF-α together with NFκB activation indicates an AGE-mediated inflammatory response. The decreased expression of Col1, OC and ALP presumably reflects a diminished osteogenic potential, whereas upregulation of RANKL and TNF-α enhances osteoclastogenesis.

CONCLUSIONS

The present study demonstrates that AGE-BSA affects the growth and function of osteoblasts. Modulation of the expression of various target genes involved in bone metabolism provides evidence that AGEs accumulated in the bone matrix have the potential to suppress osteogenic and to promote osteoclastogenic properties of osteoblasts in vivo, thereby leading to functional and structural impairment of bone.

摘要

目的

晚期糖基化终产物（AGEs）与破骨细胞相关的骨破坏疾病的发病机制有关。然而，关于 AGEs 对人成骨细胞的影响的报告仍然缺乏。本研究旨在探讨 AGE 修饰的牛血清白蛋白（AGE-BSA）对细胞生长和与成骨和破骨细胞生成相关的成骨细胞标志物表达的影响。

方法

用 AGE-BSA 刺激从骨组织标本中建立的人成骨细胞，并在体外进行研究。使用实时聚合酶链反应（PCR）测量核因子 kappa B 亚单位 p65（NFκB p65）、肿瘤坏死因子-α（TNF-α）、基质金属蛋白酶-1（MMP-1）、核因子κB 受体激活剂配体（RANKL）、骨保护素、胶原 I（Col1）、骨钙素（OC）和碱性磷酸酶（ALP）的 mRNA 表达。通过 Western blot 分析或 ELISA 评估相应的蛋白质表达。通过荧光素酶测定和电泳迁移率变动分析（EMSA）研究 NFκB 激活。评估细胞周期分析、细胞增殖以及坏死和早期凋亡的标志物。

结果

AGE-BSA 被主动摄取到成骨细胞中，并诱导细胞周期停滞和增加坏死细胞，但不增加凋亡细胞。RAGE 和 TNF-α的表达增加以及 NFκB 的激活表明存在 AGE 介导的炎症反应。Col1、OC 和 ALP 的表达减少可能反映了成骨潜能的降低，而 RANKL 和 TNF-α的上调增强了破骨细胞生成。