TGF-β_2局部应用对大鼠角膜碱烧伤后CD44和E-selectin表达的影响

Effect of TGF-β_2 on expression of CD44 and E-selectin following corneal alkali burns in rats

目的研究TGFβ2局部应用对大鼠角膜碱烧伤后CD44和Eselectin的mRNA合成的影响,探求其对角膜碱烧伤的治疗作用。方法制备Wistar大鼠角膜碱烧伤模型,一组给予TGFβ2(浓度为1mg·L-1)局部滴眼,每日3次,一组未给予TGFβ2治疗。于角膜碱烧伤后3d和2周应用RTPCR方法检测TGFβ2治疗组与未治疗组角膜CD44和Eselectin的mRNA合成情况。结果角膜碱烧伤3d时CD44mRNA表达无显著变化,碱烧伤2周时CD44表达量增加,同正常对照组相比差异显著(P<0.01)。TGFβ2治疗组3d和2周时CD44的mRNA合成同未治疗组相比均有增加,2组差异显著。角膜碱烧伤3d时EselectinmRNA的表达量低于正常对照组,碱烧伤2周时Eselectin表达量高于正常对照组,有显著差异(P<0.01)。TGFβ2治疗组3d和2周时Eselectin的mRNA合成同未治疗组相比均有增加,3d时增加明显,差异极显著。结论TGFβ2能促进急性期和营养紊乱期CD44和EselectinmRNA的合成,减轻碱烧伤后的炎症反应。TGFβ2能够通过影响角膜局部粘附分子的合成和表达来减轻病理损伤,促进创伤愈合。

Objective To observe the effect of TGF-β2 applied topically to the alkali burned cornea on mRNA synthesis and expression of CD44 and E-selectin and its therapeutic action on corneal alkali burns. Methods We induced the model of corneal alkali burns in Wistar rat. Those animals were divided into two groups, one group applying TGF-β2 （ 1 mg· L^-1 ） topically to the injured cornea three times one day,another group without application of TGF-β2.These rats were sacrificed on the 3rd day and in the 2nd week after burn. We tested the expression of mRNA of CD44 and E-selecttn by RT-PCR. Total RNA was isolated from the excised cornea and reverse-transcribed into cDNA. The PCR products were separated by electrophoresis in 2 % agarose gels and analyzed by a Pharmacia Blotech Image Master VDS Video Documentation system using image analysis softmare. The optical intensity of each PCR product was normalized to that of β-actin from the same animal and clectrophoresed. Results There was not change in expression of CD44 mRNA on the 3rd day and the expression increased significantly in the 2nd week. The expression of E-selectin mRNA decreased on the 3rd day and increased significantly in the 2nd week with significant difference compared to the control （P 〈 0.01 ）. The expression of CD44 and E-selectin of treated group on the 3rd day and in the 2nd week after corneal alkali burns increased significantly compared in the untreated group. Conclusion TGF-β2 could upregulate CD44 and E-selectin on mRNA synthesis during period of nutrational confusion of corneal alkali burns. TGF-β2 could lighten pathologic injury and accelerate the wound healing by affecting the synthesis and expression of CD44 and E-selectin. [Rec Adv Ophthalmol 2006;26.（7）：491-494]