Monaghan P, Perusinghe N, Carlile G, Evans W H
Institute of Cancer Research, Haddow Laboratories, Sutton, Surrey, United Kingdom.
J Histochem Cytochem. 1994 Jul;42(7):931-8. doi: 10.1177/42.7.8014476.
We investigated the expression of gap junctions in virgin, pregnant, lactating, and involuting mouse mammary gland epithelium with a panel of sequence-specific antibodies to connexins 26, 32, 40 and 43. Indirect immunofluorescence labeling of frozen sections of mammary gland showed that connexin26 was the major connexin in mammary epithelium. Connexins 43, 40, and 32 were not detected. Connexin26 was not detected in the mammary epithelium of virgin mice but was increasingly expressed during pregnancy. At Day 4 of pregnancy, when the mammary gland was composed almost exclusively of ducts, low levels of labeling were detected in the duct epithelium. As pregnancy progressed, the level of labeling with antibodies to connexin26 increased in quantity and intensity. At Day 12, when developing lobules were present, immunolabeling for connexin26 was detected surrounding the developing lumina, which on Day 19 were distended with milk. Labeling of mammary gland reached a maximum on Day 24 (5 days' lactation) but within 24 hr of removal of the litter on Day 28, connexin26 labeling was greatly diminished. No further change in labeling intensity with the antibodies to connexins was detected throughout involution. Double immunofluorescence labeling of 5-day lactating mammary gland with antibodies to connexin26 and anti-keratin 14 or -keratin 19 indicated that the majority of gap junctions detected by this analysis were within the luminal cell population. Western blot analysis of a lactating mammary gland (Day 24) confirmed the absence or low level of expression of connexins 32 and 43, as seen in the immunofluorescence studies, and showed that connexin26 was a dominant antigen expressed in lactating mammary gland epithelium.
我们使用一组针对连接蛋白26、32、40和43的序列特异性抗体，研究了未孕、怀孕、哺乳和乳腺 involuting期小鼠乳腺上皮中缝隙连接的表达情况。乳腺冰冻切片的间接免疫荧光标记显示，连接蛋白26是乳腺上皮中的主要连接蛋白。未检测到连接蛋白43、40和32。在未孕小鼠的乳腺上皮中未检测到连接蛋白26，但在怀孕期间其表达逐渐增加。在怀孕第4天，当乳腺几乎完全由导管组成时，在导管上皮中检测到低水平的标记。随着怀孕进程的推进，针对连接蛋白26的抗体标记水平在数量和强度上均增加。在第12天，当出现发育中的小叶时，在发育中的管腔周围检测到连接蛋白26的免疫标记，在第19天这些管腔中充满了乳汁。乳腺标记在第24天（哺乳5天）达到最大值，但在第28天移除幼崽后的24小时内，连接蛋白26标记大大减少。在整个 involution期，未检测到针对连接蛋白抗体的标记强度有进一步变化。用针对连接蛋白26和抗角蛋白14或 -角蛋白19的抗体对5天哺乳期乳腺进行双重免疫荧光标记表明，该分析检测到的大多数缝隙连接位于腔面细胞群体内。对哺乳期乳腺（第24天）的蛋白质免疫印迹分析证实，如免疫荧光研究中所见，连接蛋白32和43不存在或表达水平低，并表明连接蛋白26是哺乳期乳腺上皮中表达的主要抗原。
