Tannous-Khuri L, Hillemanns P, Rajan N, Wright T C, Talmage D A
Institute of Human Nutrition, Columbia University, New York, New York 10032.
Am J Pathol. 1994 Jan;144(1):148-59.
To determine the potential roles of retinoids in the growth and differentiation of the reproductive tract epithelium, we have studied the expression of the cellular retinol- and retinoic acid-binding proteins, CRBP I and CRABP I, in the reproductive tract of female rats. CRBP I and CRABP I gene expression have been examined in the oviduct, ovary, uterus, and particularly in the cervix, which normally undergoes a cyclical squamous metaplasia during the estrus cycle. CRBP I was expressed in all four tissues examined, whereas CRABP I was expressed predominantly in cervix and uterus. In the cervix, CRBP I was detected in all epithelial layers including the columnar epithelium but was greatly reduced in the superficial, cornified layers of the stratified squamous epithelium. CRABP I was localized to the basement membrane region of the epithelium with the strongest expression in the basal layer of epithelial cells. While the expression of CRBP I and CRABP I in the keratinizing exocervix changed during the estrus cycle, it remained constant in the incompletely keratinized endocervix. The highest levels of CRBP I were seen during anestrus and proestrus, and for CRABP I during proestrus. Both CRBP I and CRABP I levels fell to barely detectable levels during estrus and metestrus. Using estrogen repletion of ovariectomized rats, we found that CRABP I levels transiently increased during the early proliferative response to estrogen, whereas CRBP I levels gradually declined, becoming barely detectable by 24 to 48 hours. These results suggest that CRBP I and CRABP I play different roles in the cyclical squamous metaplasia normally occurring in this tissue and that hormonal control of CRBP I and CRABP I expression might modulate the retinoid responsiveness of the epithelium during this process.
为了确定类视黄醇在生殖道上皮生长和分化中的潜在作用，我们研究了细胞视黄醇结合蛋白（CRBP I）和细胞视黄酸结合蛋白（CRABP I）在雌性大鼠生殖道中的表达。我们检测了输卵管、卵巢、子宫，尤其是子宫颈中CRBP I和CRABP I基因的表达，子宫颈在发情周期中通常会经历周期性的鳞状化生。在所检测的所有四种组织中均有CRBP I表达，而CRABP I主要在子宫颈和子宫中表达。在子宫颈中，在包括柱状上皮在内的所有上皮层中均检测到CRBP I，但在分层鳞状上皮的表层角质化层中其表达大幅降低。CRABP I定位于上皮的基底膜区域，在上皮细胞的基底层表达最强。虽然发情周期中角化性宫颈外口的CRBP I和CRABP I表达会发生变化，但在未完全角化的宫颈内口其表达保持恒定。CRBP I在动情间期和发情前期水平最高，CRABP I在发情前期水平最高。在发情期和动情后期，CRBP I和CRABP I水平均降至几乎检测不到的水平。通过对去卵巢大鼠补充雌激素，我们发现CRABP I水平在对雌激素的早期增殖反应中短暂升高，而CRBP I水平逐渐下降，在24至48小时时几乎检测不到。这些结果表明，CRBP I和CRABP I在该组织正常发生的周期性鳞状化生中发挥不同作用，并且在此过程中CRBP I和CRABP I表达的激素调控可能会调节上皮的类视黄醇反应性。
