Effect of primary cilia expression rate on Wnt/β signaling pathway in tibial growth plate chondrocytes from chronic renal insufficiency young rats

Abstract

Objective: To observe the effect of primary cilia expression rate on Wnt/β signaling pathway in tibial growth plate chondrocytes from chronic renal insufficiency (CRI) young rats. Methods: Male 2-week-old SD rats were randomly divided into two groups: (1) Sham group: only the left ureter was exposed (n=6); (2) CRI group: the left ureter was ligated (n=6). Rats were sacrificed 2 weeks after the operation and the primary cilia expression rate of growth plate chondrocytes and key protein β-catenin in Wnt/β signaling pathway were observed in histological section of tibia specimen. Chondrocytes isolated from growth plate in two groups were cultured in vitro to P3 generation. The primary cilia expression rate and the level of β-catenin were measured. The primary cilia expression rate was detected by agonists and antagonists Wnt/β signaling pathway in chondrocytes of CRI group. The level of β-catenin was detected by using serum-free culture and chloral hydrate to intervene chondrocytes in CRI group. Results: The primary cilia expression rate of growth plate chondrocytes in histological section of tibia specimen in CRI group was higher than that in Sham group [(17.5±7.7)% vs (8.7±3.6)%, t=3.237, P=0.005], and the level of β-catenin was higher in CRI group (5.1±0.7 vs 1.9±0.8, t=6.731, P<0.001). The primary cilia expression rate of growth plate chondrocytes cultured in vitro in CRI group was higher than that in Sham group [(20.9±8.1)% vs (11.8±4.7)%, t=3.073, P=0.007], and the level of β-catenin was higher in CRI group (0.49±0.12 vs 0.25±0.11, t=3.297, P=0.011). There was no significant change in primary cilia expression rate after intervention by using Wnt/β signaling agonists and antagonists to change the level of β-catenin [agonists group: (21.3±7.6)%, control: (20.6±6.8)%, antagonists group: (22.4±6.2)%, F=0.173, P=0.842]. The level of β-catenin was significantly changed after intervention by using serum-free culture, chloral hydrate to alter the primary cilia expression rate (serum-free culture group: 0.61±0.23, control: 0.39±0.24, chloral hydrate group: 0.15±0.11, F=6.476, P=0.012). There was a positive correlation between the level of β-catenin and primary cilia expression rate. Conclusion: The primary cilia expression rate and the level of Wnt/β signaling pathway were higher in tibial growth plate chondrocytes in CRI rats model, and primary cilia might have positive regulatory effects on the Wnt/β signaling pathway.