| Objective:To study the proteins related to aging in aortic of old rats for laying the foundation of further study of aging mechanism.Methods:Twenty four male Wistar-Kyoto (WKY) rats and spontaneously hypertensive rats (SHR) were randomized into two groups respectively, a total of four groups:the adult group (9weeks), the old group (12months) of WKY rats, and the age-matched SHR. The pressure and body weight of rats were measured every four weeks, and the systolic blood pressure (SBP) was measured by tail-off plethysmograph. At the end of the nine week and the twelve month, the rats were sacrificed respectively, separating the aorta and extracting protein. Morphological change of aorta was observed by HE staining. Differential proteins were identified by iTRAQ-coupled liquid chromatography and tandem mass spectrometry technology and Mascot database retrieval. The mRNA expression level of Prelamin-A and Prohibitin were subsequently detected by real time PCR, and the protein expression level of Profilin-1was detected by Western-blot.Results:The12-month-old SHR presented a significantly higher mean SBP than did age-matched normotensive WKY (P<0.05). The9-week-old SHR also exhibited a higher SBP than did young WKY (P<0.05), and the difference between the young rats was less marked than between the old rats. Furthermore, the body weight was significantly higher in WKY than in age-matched SHR (P<0.05).Compared with the adult group, aging change in the aortic morphology of old SHR and WKY were shown in HE staining, and the change in SHR rats was more marked.7proteins related to aging were identified by Mass spectrum analysis, and they are Profilin-1、 Prelamin A、HSP70、CK-M、Fibulin-5、eIF5A and Prohibitin.2proteins including Profilin-1、Prelamin A were up-regulated and5proteins including HSP70、CK-M、 Fibulin-5、eIF5A、Prohibitin were down-regulated. Part of differential proteins was subsequently confirmed by real time PCR and Western-blot. Prelamin-A was up-regulated in the old group of WKY and SHR(0.45±0.04vs0.15±0.009,0.78±0.06vs0.34±0.02)(t=12.67,12.06, P<0.01), Prohibitin was down-regulated in the old group of WKY and SHR(1.01±0.062vs1.34±0.046,0.88±0.075vs1.24±0.046)(1=7.41、7.09, P<0.01). Profilin-1was up-regulated in the old group of WKY and SHR(20.76±0.8vs9.12±0.4,55.16±0.9vs16.84±0.5)(t=22.55,64.46, P<0.01), and Profilin-1expression in the old group of SHR was higher than WKY(55.16±0.9vs20.76±0.8)(t=49.49, P<0.01)Conclusions:Differential proteins of the old rat aorta were identified through the comparative proteomics method, and part of differential proteins was detected. The preliminary discussion of biological functions of the differential proteins, suggested that they may be associated with aging. If we study these differential proteins in depth, we will lay a foundation for further discussed the molecular mechanisms of aging, and also provide new targets for the prevention and control of vascular aging. |
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