Lazowski K W, Mertz P M, Redman R S, Ann D K, Kousvelari E
Clinical Investigations and Patient Care Branch, National Institute of Dental Research, National Institutes of Health, Bethesda, MD 20892.
Differentiation. 1992 Nov;51(3):225-32. doi: 10.1111/j.1432-0436.1992.tb00700.x.
We have investigated the temporal expression and cellular localization of the c-jun proto-oncogene and two major rat parotid gland secretory protein genes, PRP (proline-rich protein) and amylase, during postnatal development. c-jun mRNA steady-state levels increased at days 1, 7 and 14 after birth and decreased to basal levels at 21 days and older. PRP mRNA was first detected at 14 days and abruptly increased to adult levels at day 21. Amylase transcripts were first seen at day 7 and progressively increased to adult levels by 28 days. In situ hybridization demonstrated c-jun mRNA accumulation in the differentiating acinar cells and the ducts. The c-jun mRNA accumulation with time corresponds with the proliferative activity reported to occur in these two cellular populations. PRP transcripts were present exclusively in the well differentiated acinar cells while the accumulation of amylase mRNA corresponded to the progressive commitment of parotid cells to acinar differentiation. Our data suggest that during the postnatal development of the rat parotid gland: (a) c-jun expression associates with parotid gland proliferation and precedes the expression of PRP and amylase genes, and (b) activation of PRP and amylase genes is not concomitant and apparently occurs only in differentiating acinar cells.
我们研究了c-jun原癌基因以及大鼠腮腺两个主要分泌蛋白基因PRP（富含脯氨酸蛋白）和淀粉酶在出生后发育过程中的时间表达和细胞定位。c-jun mRNA稳态水平在出生后第1、7和14天升高，在21天及更大时降至基础水平。PRP mRNA在14天时首次检测到，并在21天时突然升至成年水平。淀粉酶转录本在第7天首次出现，并在28天时逐渐升至成年水平。原位杂交显示c-jun mRNA在分化的腺泡细胞和导管中积累。c-jun mRNA随时间的积累与据报道在这两个细胞群体中发生的增殖活性相对应。PRP转录本仅存在于高度分化的腺泡细胞中，而淀粉酶mRNA的积累与腮腺细胞向腺泡分化的逐步进程相对应。我们的数据表明，在大鼠腮腺出生后发育过程中：(a) c-jun表达与腮腺增殖相关，并先于PRP和淀粉酶基因的表达；(b) PRP和淀粉酶基因的激活不同时发生，且显然仅发生在分化的腺泡细胞中。
