ROS/p38MAPK-induced lamin B1 accumulation promotes chronic kidney disease-associated vascular smooth muscle cells senescence

The incidence of cardiovascular thrombotic events which are highly associated with atherosclerotic plaque vulnerability and its rupture is much higher in chronic kidney disease (CKD) patients than that in the general population. It has been reported that the thinning of fibrous cap in atherosclerotic plaque is a crucial factor in plaque vulnerability and thrombosis. Moreover, vascular smooth muscle cells (VSMCs) senescence play a crucial role in maintaining the thickness of fibrous cap. Lamin B1, one of the members of laminin family, is an important component of the nuclear membrane and it is related to cell senescence. While whether lamin B1 participates CKD-related VSMCs senescence and plaque vulnerability and the underlying mechanism remain unclear. Here, we found that CKD promoted fibrous cap thinning and reduced the stability of atherosclerotic plaque through accelerating VSMCs senescence. VSMCs senescence induced by CKD was related to the increased expression of lamin B1 and abnormality of nuclear membrane structure. Knocking down the expression of lamin B1 with RNA interference prevented CKD-induced aberrant nuclear membrane structure and senescence in VSMCs. Additionally, overproduction of reactive oxidative stress (ROS) and subsequent activation of ROS/p38MAPK under CKD milieus contribute to these series of outcomes, as scavenging ROS with N-acety-l-cysteine (NAC) or inhibiting p38MAPK signal pathway with SB203580 could inhibit CKD-induced activation of ROS/p38MAPK, increased expression of lamin B1, abnormality of nuclear membrane structure and VSMCs senescence. Taken together, these results suggested that ROS/p38MAPK-mediated increased expression of lamin B1 and abnormality of nuclear membrane structure was an important mechanism of CKD-induced VSMCs senescence.