Stretch-induced Expression of CYR61 Increases the Secretion of IL-8 in A549 Cells via the NF-κβ/Iκβ Pathway

Mechanical ventilation （MV） with large tidal volumes can increase lung alveolar permeability and initiate inflammatory responses, resulting in ventilator-induced lung injury （VILI）. The mechanisms of the injurious effects of MV and the genetic susceptibility remain unclear. VILI-related genes such as cysteine-rich angiogenic inducer 61 （Cyr61） have been demonstrated to play a detrimental role in the aggressive ventilation strategies. In the present study, we investigated the involvement of Cyr61 in the VILI and the underlying mechanism. A549 cells were exposed to cyclic stretch of varying durations and then the mRNA and protein levels of Cyr61 were measured by real-time PCR and Western blotting, respectively. Additionally, after exposure ofA549 cells to cyclic stretch for 5 min to 1 h, the expression levels of nuclear factor kappaB （NF-κβ） and IL-8 were detected by ELISA and Western blotting. Thereafter, Cyr61 expression was depressed in A549 cells with the siRNA pGenesill. 1-Cyr61-3 before the cyclic stretch, and IL-8 secretion and the activation of NF- κB pathways were probed by ELISA and Western blotting, respectively. Moreover, a NF- κB inhibitor （PDTC） and an activator （TNF） were used before mechanical stretch. Realtime PCR and ELISA were performed to detect the mRNA and protein of IL-8, respectively. The results showed that the mechanical cyclic stretch led to increased Cyr61 expression at mRNA and protein levels in A549 cells. Additionally, cyclic stretch also mobilized NF- κB from the cytoplasm to the nucleus and increased IL-8 secretion in A549 cells. The inhibition of Cyr61 blocked the NF-κB activation and IL-8 secretion in response to cyclic stretch. Inhibition of NF-κB attenuated the mRNA and protein expression of IL-8 in A549 cells transfected with Cyr61 siRNA. It was suggested that Cyr61/NF-κB signaling pathway mediates the upregulation of IL-8 in response to cyclic stretch in A594 cells. These findings support the hypothesis that Cyr61 plays a critical role in acute lung inflammation triggered by mechanical strain.

Cyr61/CTGF/Nov family proteins in gastric carcinogenesis

Gastric cancer(GC)is the second leading cause of cancer-related death.The poor survival rate may reflect the relatively aggressive tumor biology of GC.Recently,the importance of the tumor microenvironment in carcinogenesis has emerged.In the tumor microenvironment,tumor cells and the surrounding stromal cells aberrantly secrete matricellular proteins capable of modulating carcinogenesis and regulating metastasis.The Cyr61/CTGF/Nov(CCN)proteins are a family of matricellular proteins with variable roles in many physiological and pathological processes.The evidence suggests that CCN family proteins contribute to GC carcinogenic processes.Here,we briefly review recent research on the effects of CCN family proteins in GC carcinogenesis and the development of new targeted agents in this field.

Cyr61 Alleviates Cholangitis by Inhibiting Cytotoxic Effects of CD8^(+) T Cells on Biliary Epithelial Cells

Objective:Primary biliary cholangitis(PBC)is a chronic progressive cholestatic liver disease.In recent years,researchers have found that cysteine-rich angiogenic inducer 61(Cyr61,also known as CCN1)has a potential role in reducing portal inflammation in patients with PBC.This study aimed to explore the relationship between Cyr61 and PBC to provide new ideas and an experimental basis for the clinical treatment of PBC.Methods:After induction of the overexpression of Cyr61 in a mouse model of PBC using recombinant adenovirus,hematoxylin and eosin staining and pathological scores were used to indicate intrahepatic inflammation and bile duct damage.Real-time PCR was used to detect changes in inflammation-related cytokines in the liver.To further study the mechanism,we assessed whether Cyr61 protects bile duct epithelial cells from cytotoxic effects.Results:Serum and hepatic Cyr61 levels were increased in the murine model of PBC.Overexpression of Cyr61 alleviated hepatic inflammation and bile duct injury in vivo.Cyr61 inhibited the cytotoxic effects of CD8^(+)T cells by acting on biliary epithelial cells(BECs)in vitro.Conclusion:Our results provide novel insight into the pathogenesis of PBC and suggest that Cyr61 plays a dominant role in the cytotoxic effects on BECs in PBC.Consequently,therapeutic strategies targeting Cyr61 could be a potent therapy for PBC.

肺癌中Cyr61的表达及其对肺癌细胞增殖、迁移和凋亡的影响

目的探讨Cyr61在非小细胞肺癌(non-small cell lung cancer,NSCLC)中的表达,以及其对NSCLC细胞增殖、迁移和凋亡的影响。方法收集63例NSCLC组织及对应癌旁组织,采用免疫组化法检测组织中Cyr61的表达,分析Cyr61表达与NSCLC临床病理特征的关系。体外培养A549、NCI-H460细胞,转染Cyr61 mimics分为空白对照组、阴性转染组、Cyr61转染组,MTT法检测细胞增殖情况;Transwell小室检测细胞侵袭、迁移能力;流式细胞仪检测细胞凋亡情况;Western blot法检测转染后细胞中Cyr61、BCL-2、Bax、Caspase-3蛋白表达。结果与癌旁组织相比,NSCLC组织中Cyr61蛋白阳性率降低,差异有统计学意义(P<0.05)。Cyr61蛋白表达与吸烟、淋巴结转移、临床分期有关(P<0.05)。转染Cyr61 mimics后,Cyr61蛋白表达、细胞迁移、侵袭数量、BCL-2蛋白表达降低(P<0.05),细胞抑制率、凋亡率、Bax、Caspase-3蛋白表达升高(P<0.05)。结论Cyr61在肺癌中呈低表达,体外过表达后能够抑制细胞增殖、迁移,诱导凋亡,其机制可能与Caspase-3凋亡通路激活有关。