[Time course of ubiquitin and rat component 3 of proteasome expressions and association with common carotid artery intimal proliferation after balloon injury in rats.].

OBJECTIVE: To investigate the dynamic ubiquitin and rat component 3 of proteasome (RC3) change and association with intimal proliferation in the common carotid artery of rats after balloon injury. METHODS: Male SD rats were randomly divided into two groups: sham operation group (n = 8), ballon injury group at various time points (1, 4, 7, 14, 21, 28-days post injury, n = 8 each). The balloon injury model was established by deendothelializing the rat common carotid aortic artery by inflated 2F balloon catheter. HE staining was used to observe the ratio of intima-media (I/M) thickness of the injured arteries under optical microscopy. The expression levels of ubiquitin and RC3 mRNA were detected with RT-PCR. The expression level of ubiquitin protein was measured by immunohistochemistry method. RESULTS: The maximal intimal proliferation and peak intima-media ratio (2.31 +/- 0.43 vs. control 0.02 +/- 0.005, P < 0.01) were seen at 28th day post injury. The peak expression of ubiquitin was observed at the 7th day post injury (1.33 +/- 0.26 vs. control 0.21 +/- 0.04, P < 0.01) and peak RC3 expression was found at the 14th day post injury (1.35 +/- 0.26 vs. control 0.31 +/- 0.06, P < 0.01). The protein expression of ubiquitin was also seen at the 14th day post injury (21.53 +/- 4.09 vs. control 4.21 +/- 0.78, P < 0.01). The expression of ubiquitin protein was positively correlated with intimal proliferation(r = 0.827, P < 0.05). CONCLUSION: The upregulated ubiquitin and RC3 expressions after balloon injury might play an important role in intimal proliferation in this model.