维生素A缺乏干眼症兔泪腺凋亡及相关基因的表达

Apoptosis and related gene expression in vitamin A deficient rabbit lacrimal gland with experimental xerophthalmia

目的 探讨维生素A缺乏兔干眼症模型泪腺上皮细胞凋亡及相关基因表达与组织损伤的关系。方法 制作 6只维生素A缺乏兔干眼症模型 ,采用原位末端标记及免疫组织化学方法 ,对模型兔及 6只对照兔泪腺组织上皮细胞中的凋亡细胞及Fas、FasL、Bax和bcl 2等相关基因蛋白的表达进行检测。结果 干眼症模型兔泪腺上皮细胞凋亡数为每高倍视野 (18.17± 5 .33)个 ,对照兔为每高倍视野 (3.5 6± 1.18)个 ,P <0 .0 0 1。模型兔泪腺导管及腺泡上皮细胞中 ,Fas、FasL及Bax阳性表达的细胞数 [每 10 0 0个细胞(416 .33± 112 .0 9)个、(45 8.6 7± 12 0 .5 2 )个及 (32 8.74± 89.0 8)个 ]均明显高于对照组 [每10 0 0个细胞阳性数为 (98.83± 5 1.2 3)个、(12 6 .88± 5 4 .0 9)个及 (87.75± 4 3.33)个 ],P <0 .0 0 1,与凋亡细胞数呈正相关 (r =0 .86 ,0 .91,0 .88;P <0 .0 1)。bcl 2阳性表达的细胞数[每 10 0 0个细胞阳性数为 (113.37± 72 .4 5 )个 ],明显低于对照组 [每 10 0 0个细胞阳性数为 (396 .6 7± 98.73)个 ],P <0 .0 0 1,与凋亡细胞数呈负相关 (r =- 0 .73,P <0 .0 5 )。结论 维生素A缺乏兔泪腺组织中上皮细胞凋亡可能是导致腺体破坏进而功能丧失的原因之一 ;Fas、FasL及Bax增加及bcl 2的减少均与促进细胞?

Objective To assess the roles of apoptosis and expression of the related genes in lacrimal glandular destruction of vitamin A deficient rabbit with experimental xerophthalmia.Methods Six rabbits were given a casein base vitamin A deficient diet for six months and then we got experimental xerophthalmia models. Small pieces of palpebral lobes of lacrimal glands were obtained from the models and 6 normal controls. They had been investigated by the in situ end labeling and immunohistochemical staining to detect the apoptotic cells and the expression of Fas, FasL, Bax and bcl 2.Results The numbers of epithelial apoptotic cells in lacrimal glands of xerophthalmia models and normal rabbits were 18.17±5.33 and 3.56± 1.18 every high view. The former was significantly higher than the later( P <0.001).Xerophthalmia models epithelial cells showed increased expression of Fas, FasL, Bax( 416.33 ± 112.09 , 458.67 ± 120.52 and 328.74 ± 89.08 every thousand cells)and decreased expression of bcl 2 (113.37±72.45 every thousand cells) than the normal (98.83±51.23,126.88±54.09, 87.75 ±43.33 and 396.67±98.73 every thousand cells), P <0.001. There was significant positive correlation between the number of apoptotic cells and that of the cells expressing Fas, FasL, Bax ( r=0.86,0.91,0.88;P <0.01) and respectively negative correlation between apoptotic cells and bcl 2( r=-0.73, P <0.05).Conclusion The apoptosis of the epithelial cells in the lacrimal gland may be one of the mechanisms leading to the glandular destruction found in xerophthalmia. The expression of Fas, FasL and Bax may promote apoptosis, respectively, bcl 2 may inhibit it.