The expression and role of Notch1/RBP-Jκ/Msx2 signaling pathway in the aorta of chronic kidney disease rats with vascular calcification / 中华肾脏病杂志

ABSTRACT

Objective To observe the expression of Notch1 signaling pathway in the aorta of chronic kidney disease (CKD) rats with vascular calcification and to explore the role of this signaling pathway activation in aortic calcification of CKD.Methods A total of 40 male SD rats were randomly divided into normal group (Nor group) and CKD with vascular calcification group (CKD+VC group).Rats in each group were sacrificed at 4 weeks,6 weeks and 8 weeks respectively after the success of modeling.Their 24-hour urine was reserved to test 24 hour urine protein (24 h Upro);blood sample was collected from abdominal aorta to test blood urea nitrogen (BUN),serum creatinine (Scr),Ca and P.The histopathology of renal was detected by HE staining.The aortic calcification was detected by alizarin red S staining.Immunohistochemistry (IHC) was used to test the protein expressions of alpha-smooth muscle actin (or-SMA),Runt-related transcription factor 2 (Runx2),Notchl,recombination signal-binding protein for immunoglobulin kappa J region (RBP-Jκ),Msh homeobox 2 (Msx2),Jagged1 and Notch1 intracellular domain (N1-ICD) in the aorta.Real time PCR was applied to detect the mRNA expressions of α-SMA,smooth muscle 22 alpha (SM22α),Runx2,alkaline phosphatase (ALP),Notch1,RBP-Jκ,Msx2 and Jagged1.Results Compared with those in Nor group,24 h Upro,BUN and Scr increased in the CKD+VC group at 4th,6th and 8th weeks (all P ＜ 0.05).Numerous continuous calcified nodules were detected in the vascular wall of the CKD+VC group,but none in Nor group.As compared with Nor group,the expression of α-SMA was low,while the expression of Runx2 was relatively high in the CKD+VC rats at each time point (all P ＜ 0.05).The expressions of Notchl,RBP-Jκ,Msx2,Jaggedl and NI-ICD in the Nor group were slightly appeared in the aortic wall,while in CKD+VC group these signal protein expressions increased relatively during the experimental period (all P ＜ 0.05).As compared with Nor group,the expressions of α-SMA and SM22α mRNA were low,yet the expressions of Runx2 and ALP mRNA were high in the CKD+VC rats at each time point (all P ＜ 0.05).The mRNA levels of Notch1,RBP-Jκ,Msx2 and Jagged1 in the CKD+VC group at each time point were significantly up-regulated as compared with the Nor group (all P ＜ 0.05).Conclusions There exist phenotypic changes in smooth muscle cells and activations of Notch1/RBP-Jκ/Msx2 signaling pathway in CKD rats with vascular calcification.It may be one of the important signal transduction pathways.