Glutamate decarboxylase （GAD） has been found in animal and higher plant tissues as well as in yeasts and microorganisms. In animals the enzyme plays an important role in central nervous system activity because the e...Glutamate decarboxylase （GAD） has been found in animal and higher plant tissues as well as in yeasts and microorganisms. In animals the enzyme plays an important role in central nervous system activity because the enzyme substrate glutamic acid is a mediator of excitation process and the product, gamma-aminobutyric acid, is the most important mediator of inhibition process in the central nervous system. GAD65 is one form of the glutamate decarboxylases （GAD）, GAD65 has been identified as a major autoantigen in type 1 diabetes, so the GAD65 gene of porcine was cloned by RT-PCR method to construct phylogenetic tree, the homology of 13 glutamate decarboxylases （GAD） of different origin was analyzed by multiple alignment.展开更多
基金Supported in part by Heilongjiang Province Tackle Key Problem Item (GB01B104)
文摘Glutamate decarboxylase （GAD） has been found in animal and higher plant tissues as well as in yeasts and microorganisms. In animals the enzyme plays an important role in central nervous system activity because the enzyme substrate glutamic acid is a mediator of excitation process and the product, gamma-aminobutyric acid, is the most important mediator of inhibition process in the central nervous system. GAD65 is one form of the glutamate decarboxylases （GAD）, GAD65 has been identified as a major autoantigen in type 1 diabetes, so the GAD65 gene of porcine was cloned by RT-PCR method to construct phylogenetic tree, the homology of 13 glutamate decarboxylases （GAD） of different origin was analyzed by multiple alignment.
文摘目的观察视网膜变性过程中γ-氨基丁酸(γ-amino butyric acid,GABA)及合成酶谷氨酸脱羧酶65(glutamicacid decarboxylase 65,GAD65)的表达变化。方法选择出生后15、30、60、90 d的RCS-P+和同年龄的RCS-rdy+-P+大鼠,采用免疫荧光(IF)和免疫印迹法(Western blot)观察两种大鼠出生后15、30、60、90 d GABA和GAD65的表达差异。结果视网膜中GABA和GAD65主要表达于内核层、内从状层和节细胞层。随着天龄的增加,RCS-rdy+-P+大鼠中GABA阳性细胞逐渐减少。RCS-P+变性鼠在出生后15～60 d GABA阳性细胞随天龄增加逐渐减少,在出生后60～90 d(即视网膜变性中晚期)GABA阳性细胞大量增加,GABA表达明显高于RCS-rdy+-P+大鼠(P<0.05)。不同年龄RCS-rdy+-P+大鼠其GAD65表达恒定,发育对GAD65表达无明显影响;与同年龄RCS-rdy+-P+大鼠相比,30 d RCS-P+大鼠GAD65表达略有增加(P<0.05),90 d时大量增加(P<0.01),其表达随病变发展明显升高。结论在视网膜色素变性过程中,GABA、GAD65在视网膜内层的表达均有显著的升高,提示输入剥夺后GABA能无长突细胞未见损伤,其活性甚至略有增高。
