CD47 associates with alpha 5 integrin and regulates responses of human articular chondrocytes to mechanical stimulation in an in vitro model.
CD47 associates with alpha 5 integrin and regulates responses of human articular chondrocytes to mechanical stimulation in an in vitro model.
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DOI：
10.1186/ar2350
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发表时间：
2008
影响因子：
4.9
通讯作者：
Salter, Donald M.
中科院分区：
文献类型：
--
作者：
Orazizadeh, Mahmoud;Lee, Herng Sheng;Groenendijk, Bianca;Sadler, S. Jane Millward;Wright, Malcolm O.;Lindberg, Frederik P.;Salter, Donald M.
最近的研究提供了整合素在骨和软骨机械信号传导中的作用的证据。整合素信号通过多种机制调节，包括与其他跨膜蛋白的相互作用。我们的目的是确定一种这样的蛋白，整合素相关蛋白（CD47/IAP）是否在软骨细胞中表达，以及它是否可能调节整合素依赖的机械转导。在静息状态和0.33 Hz的机械刺激下，研究了从肉眼正常和骨关节炎患者膝关节软骨中分离的软骨细胞。通过免疫组织学、逆转录聚合酶链反应、免疫印迹和免疫沉淀证实CD47/IAP的表达及其相关性。通过评估功能阻断抗体对原代软骨细胞的一系列电生理、细胞和分子反应的影响，以及转染CD47/IAP的CD47/IAP缺失细胞系的反应，研究了其在机械转导中的作用。人类关节软骨细胞显示表达CD47/IAP，主要是2型亚型。免疫沉淀显示CD47/IAP与α5整合素和血小板反应蛋白相关，而与SIRPα（信号调节蛋白- α）无关。功能阻断抗cd47 /IAP抗体Bric 126抑制了机械刺激诱导的膜电位、酪氨酸磷酸化和聚集蛋白mRNA相对水平升高的变化，而在B6H12（一种具有部分激动剂活性的抗体）存在下，机械刺激诱导的是膜去极化而不是膜超极化反应。CD47-null细胞系在机械刺激后未表现出细胞膜电位的变化。用CD47/IAP表达载体转染CD47-null细胞时，可以观察到机械刺激后细胞膜电位的变化，但在没有跨膜和胞内结构域的情况下，用CD47/IAP细胞外免疫球蛋白变量（IgV）结构域载体转染细胞后，没有观察到机械刺激后细胞膜电位的变化。CD47/IAP是软骨细胞机械转导所必需的。CD47/IAP可能通过与α5β1整合素和血小板反应蛋白的相互作用，调节软骨细胞对机械信号的反应。
Recent studies provide evidence of roles for integrins in mechanical signalling in bone and cartilage. Integrin signalling is modulated by various mechanisms, including interaction with other transmembrane proteins. We aimed to identify whether one such protein, integrin-associated protein (CD47/IAP), is expressed by chondrocytes and whether it may regulate integrin-dependent mechanotransduction. Chondrocytes, isolated from macroscopically normal and osteoarthritic articular cartilage of human knee joints, were studied in a resting state or following mechanical stimulation at 0.33 Hz. CD47/IAP expression and associations were confirmed by immunohistology, reverse transcription-polymerase chain reaction, Western blotting, and immunoprecipitation. Roles in mechanotransduction were studied by assessing effects of function-blocking antibodies on a range of electrophysiological, cellular, and molecular responses of primary chondrocytes and responses of CD47/IAP-null cell lines transfected with CD47/IAP. Human articular chondrocytes were shown to express CD47/IAP, predominantly the type 2 isoform. Immunoprecipitation showed association of CD47/IAP with α5 integrin and thrombospondin but not SIRPα (signal-regulatory protein-alpha). The function-blocking anti-CD47/IAP antibody Bric 126 inhibited changes in membrane potential, tyrosine phosphorylation, and elevation of relative levels of aggrecan mRNA induced by mechanical stimulation, whereas in the presence of B6H12, an antibody that has partial agonist activity, a membrane depolarisation rather than a membrane hyperpolarisation response was induced by mechanical stimulation. CD47-null cell lines did not show changes in cell membrane potential following mechanical stimulation. Changes in cell membrane potential following mechanical stimulation were seen when CD47-null cells were transfected with CD47/IAP expression vectors but were not seen following mechanical stimulation of cells transfected with vectors for the extracellular immunoglobulin variable (IgV) domain of CD47/IAP in the absence of the transmembrane and intracellular domains. CD47/IAP is necessary for chondrocyte mechanotransduction. Through interactions with α5β1 integrin and thrombospondin, CD47/IAP may modulate chondrocyte responses to mechanical signals.
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DOI：
10.1083/jcb.153.3.491
发表时间：
2001-04-30
期刊：
The Journal of cell biology
影响因子：
--
作者：
Erb L;Liu J;Ockerhausen J;Kong Q;Garrad RC;Griffin K;Neal C;Krugh B;Santiago-Pérez LI;González FA;Gresham HD;Turner JT;Weisman GA
通讯作者：
Weisman GA
影响因子：
4.8
作者：
Fitzgerald, JB;Jin, M;Grodzinsky, AJ
通讯作者：
Grodzinsky, AJ
DOI：
10.1083/jcb.135.2.533
发表时间：
1996-10
期刊：
The Journal of cell biology
影响因子：
--
作者：
Gao AG;Lindberg FP;Dimitry JM;Brown EJ;Frazier WA
通讯作者：
Frazier WA
影响因子：
4.8
作者：
Frazier, WA;Gao, AG;Linder, ME
通讯作者：
Linder, ME
影响因子：
7.8
作者：
Lindberg, FP;Gresham, HD;Brown, EJ
通讯作者：
Brown, EJ