Heparin-binding epidermal growth factor-like growth factor (HB-EGF) is increased in osteoarthritis and regulates chondrocyte catabolic and anabolic activities.
Heparin-binding epidermal growth factor-like growth factor (HB-EGF) is increased in osteoarthritis and regulates chondrocyte catabolic and anabolic activities.
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DOI：
10.1016/j.joca.2015.04.019
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发表时间：
2015-09
影响因子：
7
通讯作者：
Loeser RF
中科院分区：
文献类型：
--
作者：
Long DL;Ulici V;Chubinskaya S;Loeser RF
我们确定了表皮生长因子受体配体HB-EGF是否在软骨中产生，以及它是否调节软骨细胞合成代谢或分解代谢活性。采用从小鼠膝关节组织和正常及OA人软骨细胞中分离的RNA进行定量PCR检测HB-EGF的表达。对正常和OA人软骨和半月板切片进行免疫组化。用纤维连接蛋白片段（FN-f）作为分解代谢刺激，用成骨蛋白1 （OP-1）作为合成代谢刺激处理培养的软骨细胞。选择信号蛋白免疫印迹法分析HB-EGF对细胞信号传导的影响。在条件培养基中检测MMP-13，硫酸盐掺入法检测蛋白聚糖合成，定量PCR检测基质基因表达。手术诱导OA后8周，12月龄小鼠HB-EGF表达增加，OA膝关节的人关节软骨中HB-EGF含量增加。FN-f刺激软骨细胞HB-EGF表达，HB-EGF刺激软骨细胞MMP-13生成。然而，HB-EGF并不需要FN-f刺激MMP-13的产生。HB-EGF激活了ERK和p38 MAP激酶，并刺激Smad1在抑制丝氨酸位点的磷酸化，这与抑制OP-1介导的蛋白多糖合成和减少聚集蛋白（ACAN）有关，但与COL2A1表达无关。HB-EGF是在OA软骨中发现的一个新因子，它促进软骨细胞分解代谢活性，同时抑制合成代谢活性，提示它可能导致OA软骨中出现的分解代谢-合成代谢失衡。
We determined if the epidermal growth factor receptor ligand HB-EGF is produced in cartilage and if it regulates chondrocyte anabolic or catabolic activity. HB-EGF expression was measured by quantitative PCR using RNA isolated from mouse knee joint tissues and from normal and OA human chondrocytes. Immunohistochemistry was performed on normal and OA human cartilage and meniscus sections. Cultured chondrocytes were treated with fibronectin fragments (FN-f) as a catabolic stimulus and osteogenic protein 1 (OP-1) as an anabolic stimulus. Effects of HB-EGF on cell signaling were analyzed by immunoblotting of selected signaling proteins. MMP-13 was measured in conditioned media, proteoglycan synthesis was measured by sulfate incorporation, and matrix gene expression by quantitative PCR. HB-EGF expression was increased in 12-month old mice at 8 weeks after surgery to induce OA and increased amounts of HB-EGF were noted in human articular cartilage from OA knees. FN-f stimulated chondrocyte HB-EGF expression and HB-EGF stimulated chondrocyte MMP-13 production. However, HB-EGF was not required for FN-f stimulation of MMP-13 production. HB-EGF activated the ERK and p38 MAP kinases and stimulated phosphorylation of Smad1 at an inhibitory serine site which was associated with inhibition of OP-1 mediated proteoglycan synthesis and reduced aggrecan (ACAN) but not COL2A1 expression. HB-EGF is a new factor identified in OA cartilage that promotes chondrocyte catabolic activity while inhibiting anabolic activity suggesting it could contribute to the catabolic-anabolic imbalance seen in OA cartilage.