Cytosolic Hsp60 orchestrates the survival and inflammatory responses of vascular smooth muscle cells in injured aortic vessels by regulating NF-?B-dependent gene expression

Pro-inflammatory response of VSMCs is triggered by endothelial damage and a causative step for thrombosis and neointimal thickening in the arterial vessels. Therefore, we investigate a role of cytosolic Hsp60 as a novel pro-inflammatory mediator in VSMCs. Hsp60 was detected in the cytosol of VSMCs. The selective depletion of cytosolic Hsp60 in VSMCs reduced the IKK activation, repressed the induction of NF-?B-dependent pro-survival genes (MnSOD and Bfl-1/A1), and enhanced apoptotic death in response to TNF-a. Moreover, a quantitative RNA sequencing revealed that the expression of 75 genes among the 774 TNF-a-inducible genes was significantly reduced by the depletion of cytosolic Hsp60. In particular, the expression of pro-inflammatory cytokines/chemokines, such as CCL2, CCL20, and IL-6, was regulated by the cytosolic Hsp60 in VSMCs. Finally, the depletion of cytosolic Hsp60 markedly inhibited the neointimal thickening in the balloon-injured arterial vessels by inducing apoptotic cell death and inhibiting chemokine production. This study provides the first evidence that cytosolic Hsp60 could be a therapeutic target for preventing inflammation-driven VSMC hyperplasia in the injured vessels. Overall design: Hsp60 normal vs knockout with TNF-alpha treatment

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Choi B, Choi M, Park C, Lee EK, Kang DH, Lee DJ, Yeom JY, Jung Y, Kim J, Lee S, Kang SW