Glial fibrillary acidic protein‐solubility characteristics, relation to cell growth phases and cellular localization in rat C‐6 glioma cells: an immunoradiometric and immunohistologic study
Glial fibrillary acidic protein‐solubility characteristics, relation to cell growth phases and cellular localization in rat C‐6 glioma cells: an immunoradiometric and immunohistologic study
复制标题
大鼠 C-6 神经胶质瘤细胞中胶质原纤维酸性蛋白溶解度特征、与细胞生长期和细胞定位的关系：免疫放射和免疫组织学研究
作者：
C. Liao;L. Eng;M. M. Herman;K. Bensch
(我公司lihrillary酸性iFA)蛋白质已被证明他二世\ pccilic标记星形胶质细胞(EN (; P我ol。， 1971；Bignaui ci 01..1972年:在<;& KOSFK。1974年;我不喜欢……[qh]它的普遍性已得到证实。在某些特殊条件下。在大鼠C-6胶质瘤细胞中，一种相对未分化的神经胶质瘤细胞。免疫荧光法检测。1974)。它只存在于偶尔维持单层或悬浮培养的C-6细胞中，但在维持i ？在器官培养系统里待了14天。然而，胶质蛋白的增加与胞浆内丝的产生无关。通过tv+o位点免疫放射测定法（2位点IRMA）的定量分析表明，与在单层或悬浮培养中维持相同时间的细胞相比，在器官培养系统中维持6天和13天的同一细胞系中，水溶性GFA蛋白显著增加（BISSELL等）。1975)。因为在器官培养中，无论是用单层培养基还是用器官培养的富集培养基，GFA蛋白都有所增加。初步认为，在器官培养系统的泡沫基质中发生的细胞间接触可能在增加蛋白质产量中起主要作用。然而，在器官培养系统中发现的更有利的细胞氧合速率也可能是一个因素。如其他地方所讨论的（BISSELL等）。, 1975)。人们提出的问题是，不同培养体系中GFA蛋白产量的变化是否主要是由于溶解度的差异，而不是由于蛋白质总量的差异（BIGNAMI, 1975）。几个工人（工程师）…1971年;工程与工业，1973；DAHL & BICNAMI, 1973)表明，GFA蛋白仅部分用水从人脑组织中提取，并提出水溶性GFA蛋白代表未聚合的胶质纤维形式，而水不溶性（洗涤剂溶性）GFA蛋白代表聚合的胶质纤维形式。此外，结合免疫过氧化物酶法表明，GFA蛋白与80-90nm的胶质细丝（ENG & KOSEK）在地形上相关。1974)。由于现在可以用洗涤剂溶解水不溶性GFA蛋白，并通过我们的2点IRMA测定GFA蛋白浓度（LEE等，1976）。
( i i IAI lihrillary acidic It iFA) protein has been shown to he ii \pccilic marker for astrocytes (EN(; P I ol., 1971 ; BIGNAUI CI 01.. 1972: EN<; & KOSFK. 1974; L[II)WIN t'f ul.. 1Y7hl I t \ prewnce has been demonstrated. in certain spccilic conditions. in rat C-6 glioma cells, a line of relaribel) undinerentiated glial tumor cells. By immunofluoresccnce IHISSILL er ul.. 1974). i t was present in only an occahional C-6 cell maintained in monolayer or suspension culturc hut was found in most cells after maintenance for I ? 14 days in an organ culture system. This increase in glial protein was not associated, however, with intracytoplasmic filament production. Quantitative analysis by a tv+o-site immunoradiometric assay (2-site IRMA) demonstrated a marked increase of aqueous soluble GFA protein in the same line of cells maintained in an organ culture system for 6 and 13 days as compared to those maintained for slmilar periods in monolayer or suspension cultures (BISSELL er al.. 1975). Since the increased GFA protein occurred in organ culture both with the medium used for monolayer and with the enriched medium used for organ culture. i t was tentatively suggested that cell-to-cell contact occurring in the foam matrices of the organ culture system might play the major role in the increased production of the protein. However, the more favorable rates of cellular oxygenation found in the organ culture system might also be a factor. as discussed elsewhere (BISSELL ef a/., 1975). The question has been raised whether the variation in GFA protein production in the various culture systems is due mainly to differences in solubility rather than to differences in the total amount of the protein (BIGNAMI, 1975). Several workers (ENG er a/.. 1971 ; ENG & UYEDA, 1973; DAHL & BICNAMI, 1973) showed that GFA protein is only partially extracted with water from human brain tissue, and suggested that the water-soluble GFA protein represented the unpolymerized form of glial filaments while the water-insoluble (detergent-soluble) GFA protein represented the polymerized glial filaments. In addition, it was shown by the conjugated-immunoperoxidase method that GFA protein is topographically associated with the 80-90nm glial filaments (ENG & KOSEK. 1974). Since it IS now possible to solubilize the water-insoluble GFA protein with detergent and to determine the GFA protein concentration by our 2-site IRMA assay (LEE ef al., 1976).