Tseng H, Matsuzaki K, Lavker R M
Department of Dermatology and Cancer Center, University of Pennsylvania, Philadelphia 19104, USA.
Differentiation. 1999 Dec;65(4):221-7. doi: 10.1046/j.1432-0436.1999.6540221.x.
Basonuclin is a zinc finger protein with highly restricted tissue distribution. It has been found in abundance only in keratinocytes of stratified epithelia and the germ cells of the testis and ovary. We studied the expression pattern of basonuclin in relation to cellular proliferation and differentiation in murine corneal and lens epithelia, two self-renewing tissues in the eye which contain cells that proliferate throughout life. Mouse corneal and lens epithelial cells at various stages of development were labeled with BrdU for 90 min to detect cells in S phase and to establish proliferative rates. Whole eyes of mouse or rat were processed for frozen sections and cellular basonuclin was detected by either a rabbit antimouse- or a rabbit anti-human-basonuclin antibody. Basonuclin was expressed in virtually all cells in the basal layer of corneal epithelium and in the pre-equatorial lens epithelium, the respective proliferative compartments of adult corneal and lens epithelia. Basonuclin expression in corneal epithelium began at post-natal life day 4, first in a few cells and then spread to virtually all basal cells at day 20. Basonuclin was consistently absent in limbal epithelium. Lens basonuclin, which was detected earlier than that of the cornea, was confined to the pre-equatorial epithelium and was absent in equatorial cells that expressed p57KIP2, an early differentiation marker for these cells. An important distinction between corneal and lens basonuclin is that the former is predominantly nuclear whereas the latter cytoplasmic.
碱性成纤维细胞生长因子结合蛋白是一种组织分布高度受限的锌指蛋白。仅在复层上皮的角质形成细胞以及睾丸和卵巢的生殖细胞中大量发现。我们研究了碱性成纤维细胞生长因子结合蛋白在小鼠角膜和晶状体上皮细胞中的表达模式，这两种眼内的自我更新组织含有终生增殖的细胞。用溴脱氧尿苷（BrdU）标记处于不同发育阶段的小鼠角膜和晶状体上皮细胞90分钟，以检测处于S期的细胞并确定增殖率。对小鼠或大鼠的全眼进行冷冻切片处理，并用兔抗小鼠或兔抗人碱性成纤维细胞生长因子结合蛋白抗体检测细胞中的碱性成纤维细胞生长因子结合蛋白。碱性成纤维细胞生长因子结合蛋白在角膜上皮基底层的几乎所有细胞以及赤道前晶状体上皮中表达，这分别是成年角膜和晶状体上皮的增殖区室。角膜上皮中的碱性成纤维细胞生长因子结合蛋白在出生后第4天开始表达，最初在少数细胞中表达，然后在第20天扩散到几乎所有基底层细胞。角膜缘上皮中始终不存在碱性成纤维细胞生长因子结合蛋白。晶状体碱性成纤维细胞生长因子结合蛋白的检测早于角膜，局限于赤道前上皮，而在表达p57KIP2（这些细胞的早期分化标志物）的赤道细胞中不存在。角膜和晶状体碱性成纤维细胞生长因子结合蛋白的一个重要区别在于，前者主要位于细胞核，而后者位于细胞质。
