PDGF-D/PDGFR-β信号通路在大鼠心肺复苏后心肌纤维增生中的作用机制

The role of PDGF-D/PDGFR-βsignaling in myocardial fibroplasia in rats resuscitated from cardiac arrest

目的研究PDGF-D/PDGFR-β信号通路在大鼠心肺复苏后心肌间质胶原增生及纤维增殖中的作用机制。方法90只雄性SD大鼠,随机(随机数字法)分为5组:假手术组(Sham)、对照组(Control)、伊马替尼组(Imatinib)、腺病毒GFP组(Ad-GFP)和腺病毒PDGFR组(Ad-PDGFR);每组再分为复苏后(post-resuscitation,PR)4 h和PR72 h两个亚组。采用致颤法心肺复苏模型,心肌苦味酸-天狼猩红染色计算间质胶原容积分数(CVF),酶联免疫吸附测定法检测血浆PDGF-D表达,Western blot检测CollagenⅠ、α-SMA、Vimentin和PDGFR-β表达。多组间参数比较用二因素方差分析(two-way ANOVA),两两比较用Bonferroni检验,以P<0.05为差异有统计学意义。结果(1)PR72 h,Control组CVF值显著高于Sham组[(11.24±0.31)vs(1.65±0.19),t=10.81,P<0.05],Ad-PDGFR组显著高于Ad-GFP组[(25.60±4.09)vs(10.73±2.42),t=16.77,P<0.05],Imatinib组较Contol组显著减少[(5.11±0.29)vs(11.24±0.31),t=3.892,P<0.05];(2)在PR4h,Control组、Imatinib组、Ad-GFP组及Ad-PDGFR组PDGF-D表达较Sham组显著增加(均P<0.05);在PR72 h,Ad-PDGFR组PDGF-D表达仍较Sham组显著增加[(296.46±30.82)pg/ml vs(93.74±5.43)pg/ml,t=7.755,P<0.05];(3)在PR72 h,Control组CollagenⅠ、α-SMA、Vimentin和PDGFR-β表达较Sham组显著增加,Ad-PDGFR组上述蛋白表达均较Ad-GFP组显著增加,Imatinib组较Control组显著下降(均P<0.05)。结论大鼠心肺复苏后72 h出现心肌间质胶原增生和心肌纤维增殖,这可能与血浆PDGF-D增加及心肌PDGFR-β表达增多有关。

Objective To investigate the effects of PDGF-D/PDGFR-βsignaling on interstitial collagen hyperplasia and fibroplasia of myocardium following cardiopulmonary resuscitation(CPR)in rats.Methods A total of 90 male Sprague-Dawley(SD)rats were randomly(random number)assigned into 5 groups:sham,control,Imatinib,Ad-GFP and Ad-PDGFR groups.Each group was further subdivided into post-resuscitation(PR)4 h and PR 72 h groups.The ventricular fibrillation cardiopulmonary resuscitation(CPR)model was used.Cardiac collagen volume fraction(CVF)was measured with Sirius red staining.Platelet derived growth factor D(PDGF-D)was detected by enzyme-linked immunosorbent assay(ELISA).CollagenⅠ,αsmooth muscle actin(α-SMA),vimentin and PDGF receptorβ(PDGFRβ)were detected by Western blot.The data were analyzed by a two-way ANOVA and Bonferroni test.P<0.05 was considered statistically significant.Results(1)At PR 72 h,the CVF value in the control group was significantly higher than that in the sham group[(11.24±0.31)vs(1.65±0.19),t=10.81,P<0.05]and in the Ad-PDGFR group significantly higher than that in Ad-GFP group[(25.60±4.09)vs(10.73±2.42),t=16.77,P<0.05],respectively.Compared to the control group,the level of CVF in the Imatinib group significantly decreased[(5.11±0.29)vs(11.24±0.31),t=3.892,P<0.05].(2)At PR 4 h,compared with the sham group,the expression of serum PDGF-D was greatly increased in the control,Imatinib,Ad-GFP and Ad-PDGFR groups(all P<0.05).At PR 72 h,serum PDGF-D was continuously significantly higher in the Ad-PDGFR group when compared with the sham group[(296.46±30.82)pg/mL vs(93.74±5.43)pg/mL,t=7.755,P<0.05].(3)At PR 72 h,the expression of Collagen I,α-SMA,Vimentin and PDGFR-βin the control and Ad-PDGFR groups were significantly increased than those in the sham and Ad-GFP groups,respectively(all P<0.05).However,compared with the control group,Imatinib significantly decreased the expressions of the above proteins(all P<0.05).Conclusions The interstitial collagen hyperplasia and fibroplasia of myocardium at 72 h following CPR in rats might be related to the increased levels of PDGF-D in serum and PDGFR-βin myocardium.