Role of the NLRP3 inflammatory signaling pathway in promoting neointimal hyperplasia associated with chronic renal disease / 中华肾脏病杂志

ABSTRACT

Objective:To investigate the role and mechanism of Nod-like receptor protein 3 (NLRP3) in chronic kidney disease (CKD)-related neointimal hyperplasia (NH) of vessels.Methods:Wild type C57BL/6J male mice were randomly divided into normal control group ( n=6) and experimental group ( n=18), by removal of 5/6 kidney and ligation of left common carotid artery to establish a NH model. After established successfully, the mice in NH experimental group were randomly divided into NH model group, NLRP3 inhibitor group, and drug control group ( n=6/group). C57BL/6J male mice with NLRP3 gene knockout group did not do any treatment after the establishment of NH model. After 3 weeks of feeding, the blood and vascular tissue samples of mice were collected. The pathological changes of vascular tissue samples in mice were observed by hematoxylin-eosin staining. The expressions and localization of NLRP3-related protein were observed by immunofluorescence staining. The expression of NLRP3 mRNA in vascular tissue was detected by quantitative real-time PCR. The activity of caspase-1 in vascular tissue was measured by colorimetric method. Human aortic smooth muscle cells (HASMCs) were treated with 10% uremic serum to simulate the body's internal environment during the uremic phase. NLRP3 small interfering RNA (siRNA) was transfected or NLRP3 inhibitor glibenclamide was added to the cell cultures. The expression of NLRP3 mRNA in HASMCs was detected by quantitative real-time PCR. The activity of caspase-1 in HASMCs was detected by colorimetric method. Results:Compared with the control group, the levels of serum creatinine and blood urea nitrogen were significantly increased in the NH model group (both P<0.01). The vascular histopathology showed that vascular intima thickened, vascular smooth muscle cells proliferated and hypertrophied, nuclei were deeply stained, and cells arranged disorderly and migrated to vascular intima in the experimental group. Quantitative analysis showed that the ratio of neointima to lumen increased significantly in the NH model group than that in control group ( P<0.01). Compared with the control group, the immunofluorescence staining of vascular tissue showed that the expressions of NLRP3, caspase-1, IL-18, IL-1β and proliferating cell nuclear antigen (PCNA) protein in the NH model group increased (all P<0.01), while the expression of α-SMA decreased ( P<0.01). NLRP3 was mainly located in vascular smooth muscle cells (VSMCs). VSMCs showed a synthetic phenotype. Compared with the NH model group, the expression of NLRP3, caspase-1, IL-18, IL-1β and PCNA protein in the NLRP3 inhibitor group and NLRP3 gene knockout group decreased (all P<0.01), the expression of α-SMA increased ( P<0.01), and the pathological changes of blood vessels alleviated. Compared with healthy serum group, the expression of NLRP3, IL-18, and IL-1β and bromodeoxyuridine (BrdU) uptake in uremic serum-stimulated group were increased (all P<0.01). After transfection of NLRP3 siRNA and addition of glibenclamide, the expression of NLRP3, IL-18, and IL-1β in VSMCs in uremic serum-stimulated group decreased, and BrdU intake decreased (all P<0.01). Conclusions:NLRP3 inflammatory bodies play an important role in promoting CKD-related neointimal hyperplasia of vessels, and glibenclamide can effectively reduce neointimal hyperplasia.