Faraonio R, Galdieri M, Colantuoni V
Dipartimento di Biochemica e Biotecnologie Mediche, II Facoltà di Medicina e Chirurgia, Università degli Studi di Napoli, Italy.
Eur J Biochem. 1993 Feb 1;211(3):835-42. doi: 10.1111/j.1432-1033.1993.tb17616.x.
The levels of the mRNA corresponding to the intracellular binding proteins for retinoic acid and retinol (CRABP1 and CRBP1, respectively) were studied in primary cultures of somatic and germ cells of the rat seminiferous tubules. We show that the CRABP1 mRNA is expressed in Sertoli and germ cells and a single molecular species of mRNA is detected. CRBP1 mRNA is detected in Sertoli and peritubular cells. The regulation of the expression of both genes by retinoids was studied in Sertoli cells. CRABP1 mRNA levels are not affected by either retinoic acid or retinol, whereas both compounds positively regulate CRBP1 mRNA synthesis in a dose-dependent manner. A fivefold increase in CRBP1 mRNA levels was observed 32-48 h after addition of either agent. These results demonstrate that in Sertoli cells the expression of CRABP1 is not affected by retinoids, similar to the situation observed in vivo and in other in-vitro cultures. CRBP1-gene expression is, instead, induced and the variations in CRBP1-mRNA levels may regulate the intracellular concentrations of retinoids, as a response to changes in the vitamin-A nutritional status.
在大鼠生精小管的体细胞和生殖细胞原代培养物中，研究了与视黄酸和视黄醇细胞内结合蛋白（分别为CRABP1和CRBP1）相对应的mRNA水平。我们发现，CRABP1 mRNA在支持细胞和生殖细胞中表达，且检测到单一分子种类的mRNA。CRBP1 mRNA在支持细胞和睾丸周细胞中被检测到。在支持细胞中研究了类视黄醇对这两个基因表达的调控。CRABP1 mRNA水平不受视黄酸或视黄醇的影响，而这两种化合物均以剂量依赖方式正向调节CRBP1 mRNA的合成。添加任何一种试剂后32 - 48小时，观察到CRBP1 mRNA水平增加了五倍。这些结果表明，在支持细胞中，CRABP1的表达不受类视黄醇的影响，这与体内和其他体外培养中观察到的情况相似。相反，CRBP1基因表达被诱导，并且CRBP1 - mRNA水平的变化可能作为对维生素A营养状况变化的一种反应，调节类视黄醇的细胞内浓度。
