Chaqour Brahim, Goppelt-Struebe Margarete
Department of Anatomy and Cell Biology, SUNY Downstate Medical Center, Brooklyn, NY, USA.
FEBS J. 2006 Aug;273(16):3639-49. doi: 10.1111/j.1742-4658.2006.05360.x. Epub 2006 Jul 19.
Cells in various anatomical locations are constantly exposed to mechanical forces from shear, tensile and compressional forces. These forces are significantly exaggerated in a number of pathological conditions arising from various etiologies e.g., hypertension, obstruction and hemodynamic overload. Increasingly persuasive evidence suggests that altered mechanical signals induce local production of soluble factors that interfere with the physiologic properties of tissues and compromise normal functioning of organ systems. Two immediate early gene-encoded members of the family of the Cyr61/CTGF/Nov proteins referred to as cysteine-rich protein 61 (Cyr61/CCN1) and connective tissue growth factor (CTGF/CCN2), are highly expressed in several mechanical stress-related pathologies, which result from either increased externally applied or internally generated forces by the actin cytoskeleton. Both Cyr61 and CTGF are structurally related but functionally distinct multimodular proteins that are expressed in many organs and tissues only during specific developmental or pathological events. In vitro assessment of their biological activities revealed that Cyr61 expression induces a genetic reprogramming of angiogenic, adhesive and structural proteins while CTGF promotes distinctively extracellular matrix accumulation (i.e., type I collagen) which is the principal hallmark of fibrotic diseases. At the molecular level, expression of the Cyr61 and CTGF genes is regulated by alteration of cytoskeletal actin dynamics orchestrated by various components of the signaling machinery, i.e., small Rho GTPases, mitogen-activated protein kinases, and actin binding proteins. This review discusses the mechanical regulation of the Cyr61 and CTGF in various tissues and cell culture models with a special attention to the cytoskeletally based mechanisms involved in such regulation.
处于不同解剖位置的细胞不断受到来自剪切力、拉力和压力的机械力作用。在多种病因引起的一些病理状况下,如高血压、梗阻和血流动力学过载,这些力会显著增强。越来越多有说服力的证据表明,机械信号改变会诱导可溶性因子的局部产生,这些因子会干扰组织的生理特性并损害器官系统的正常功能。富含半胱氨酸蛋白61(Cyr61/CCN1)和结缔组织生长因子(CTGF/CCN2)是Cyr61/CTGF/Nov蛋白家族中两个由即刻早期基因编码的成员,在几种与机械应力相关的病理状况中高度表达,这些病理状况是由肌动蛋白细胞骨架外部施加的力增加或内部产生的力增加所致。Cyr61和CTGF在结构上相关但功能不同,是多模块蛋白,仅在特定的发育或病理事件中在许多器官和组织中表达。对它们生物学活性的体外评估表明,Cyr61的表达会诱导血管生成、黏附及结构蛋白的基因重编程,而CTGF则特别促进细胞外基质(即I型胶原)的积累,这是纤维化疾病的主要特征。在分子水平上,Cyr61和CTGF基因的表达受信号传导机制的各种成分(即小Rho GTP酶、丝裂原活化蛋白激酶和肌动蛋白结合蛋白)精心调控的细胞骨架肌动蛋白动力学改变的调节。本综述讨论了Cyr61和CTGF在各种组织和细胞培养模型中的机械调节,特别关注参与这种调节的基于细胞骨架的机制。