Velloso L A, Kämpe O, Eizirik D L, Hallberg A, Andersson A, Karlsson F A
Department of Internal Medicine, University Hospital, Uppsala, Sweden.
Diabetologia. 1993 Jan;36(1):39-46. doi: 10.1007/BF00399091.
The presence of one of the major targets for autoantibodies in Type 1 (insulin-dependent) diabetes mellitus, the enzyme glutamic acid decarboxylase, was studied in human, rat and mouse pancreatic tissue using immunoprecipitation and immunohistochemical techniques. Immunoprecipitation of glutamic acid decarboxylase was attempted with lysates of [35S]-methionine-labelled rat or mouse pancreatic islets using two different glutamic acid decarboxylase antisera, one mouse monoclonal antibody raised against the 65 kDa isoform of the enzyme, sera from six patients with Type 1 diabetes, one patient with stiff-man syndrome and sera from 19 non-obese diabetic mice. The same sera were used for immunoperoxidase staining of cryosections of human, rat or mouse pancreas. Using patient sera glutamic acid decarboxylase was detected by immunoprecipitations from isolated rat islets but not from islets of five different mouse strains tested, including the non-obese diabetic mouse. When using the non-obese diabetic mouse sera, glutamic acid decarboxylase could not be detected in either rat or mouse tissue. Immunoperoxidase staining demonstrated high levels of glutamic acid decarboxylase in human and rat pancreatic islets but low levels in mouse islets. Direct measurements of enzyme activity showed glutamic acid decarboxylase to be present in mouse islets at a level of about 40% of that in rat islets, and subsequent Western blot analyses indicated that mouse islets express the 67 kDa isoform, whereas as in rat islets both the 67 and 65 kDa isoforms are present.(ABSTRACT TRUNCATED AT 250 WORDS)
利用免疫沉淀和免疫组化技术，对1型（胰岛素依赖型）糖尿病自身抗体的主要靶标之一——谷氨酸脱羧酶，在人、大鼠和小鼠胰腺组织中的情况进行了研究。使用两种不同的谷氨酸脱羧酶抗血清，尝试对[35S] - 甲硫氨酸标记的大鼠或小鼠胰岛裂解物进行谷氨酸脱羧酶的免疫沉淀，一种是针对该酶65 kDa异构体产生的小鼠单克隆抗体，六种1型糖尿病患者的血清，一名僵人综合征患者的血清以及19只非肥胖糖尿病小鼠的血清。同样的血清用于人、大鼠或小鼠胰腺冰冻切片的免疫过氧化物酶染色。使用患者血清，通过对分离的大鼠胰岛进行免疫沉淀检测到了谷氨酸脱羧酶，但在所测试的五种不同小鼠品系（包括非肥胖糖尿病小鼠）的胰岛中未检测到。使用非肥胖糖尿病小鼠血清时，在大鼠或小鼠组织中均未检测到谷氨酸脱羧酶。免疫过氧化物酶染色显示，人及大鼠胰腺胰岛中谷氨酸脱羧酶水平较高，而小鼠胰岛中水平较低。酶活性的直接测量表明，小鼠胰岛中谷氨酸脱羧酶的含量约为大鼠胰岛的40%，随后的蛋白质印迹分析表明，小鼠胰岛表达67 kDa异构体，而大鼠胰岛中同时存在67 kDa和65 kDa异构体。（摘要截选至250字）
