Redling Stephanie, Pfaff Imke L, Leitges Michael, Vallon Volker
Institute of Pharmacology and Toxicology, University of Tübingen, 72074 Tuebingen, Germany.
Am J Physiol Renal Physiol. 2004 Aug;287(2):F289-98. doi: 10.1152/ajprenal.00273.2003. Epub 2004 Mar 23.
Localization of protein kinase C (PKC) isoenzymes alpha, beta I, beta II, delta, and epsilon was studied employing Western blot analysis and immunohistochemical methods including confocal laser-scanning microscopy in the kidney of two mice strains, namely, C57BL/6 and 129/Sv, which have recently been used as genetic backgrounds for respective knockout mice. Immunoblot analysis identified immunoreactive bands for each isoenzyme in total kidney cell extracts. Isoenzyme expression sites were identical for both strains. Glomeruli expressed PKC-alpha, -beta I, and -epsilon. The latter isoenzyme was also detected in apical aspects of proximal convoluted but not in proximal straight tubules. In contrast to rats, neither PKC-alpha nor PKC-beta I was detectable in the proximal tubule. Immunofluorescence was observed in luminal membranes of medullary (MTAL) and cortical thick ascending limbs for PKC-beta I and in MTAL for PKC-epsilon. The cortical collecting duct expressed PKC-alpha, -beta I, and -delta in intercalated cells only. In the outer medullary collecting duct, PKC-alpha and -beta I were detectable in principal cells, whereas PKC-delta was found in intercalated cells. In the inner medullary collecting duct, PKC-alpha, -beta I, and -beta II were detected. As described for the rat, the expression of PKC-beta II was otherwise restricted to cortical and medullary interstitial cells. The specificity of all labeling was confirmed in respective PKC isoenzyme knockout mice. In summary, distinct expression patterns were shown for PKC isoenzymes alpha, beta I, beta II, delta, and epsilon in the mouse kidney.
利用蛋白质印迹分析和免疫组织化学方法（包括共聚焦激光扫描显微镜），研究了蛋白激酶C（PKC）同工酶α、βI、βII、δ和ε在两种小鼠品系（即C57BL/6和129/Sv）肾脏中的定位，这两种品系最近被用作各自基因敲除小鼠的遗传背景。免疫印迹分析在全肾细胞提取物中鉴定出每种同工酶的免疫反应条带。两种品系的同工酶表达位点相同。肾小球表达PKC-α、-βI和-ε。后一种同工酶也在近端曲管的顶端部分检测到，但在近端直小管中未检测到。与大鼠不同，近端小管中未检测到PKC-α和PKC-βI。在髓质（MTAL）和皮质厚升支的管腔膜中观察到PKC-βI的免疫荧光，在MTAL中观察到PKC-ε的免疫荧光。皮质集合管仅在闰细胞中表达PKC-α、-βI和-δ。在外髓集合管中，主细胞中可检测到PKC-α和-βI，而闰细胞中可检测到PKC-δ。在内髓集合管中，检测到PKC-α、-βI和-βII。如对大鼠的描述，PKC-βII的表达否则仅限于皮质和髓质间质细胞。在各自的PKC同工酶基因敲除小鼠中证实了所有标记的特异性。总之，小鼠肾脏中PKC同工酶α、βI、βII、δ和ε呈现出不同的表达模式。
