Rosewicz S, Ahnert-Hilger G, Haller H, Riecken E O, Wiedenmann B
Department of Gastroenterology, Klinikum Steglitz, Freie Universität Berlin, Germany.
Ann N Y Acad Sci. 1994 Sep 15;733:407-15. doi: 10.1111/j.1749-6632.1994.tb17290.x.
The rat pancreatic acinar tumor cell line, AR42J, is widely used to study pancreatic acinar cell biology and biochemistry. In addition to the well-documented exocrine cell features, we have identified by immunofluorescence and by electron microscopy the co-expression of small neuroendocrine (NE) vesicles using the NE vesicle-specific markers synaptophysin and "protein S.V.2." AR24J cells store [3H]GABA, which is secreted upon potassium depolarization in a calcium-dependent manner. In addition, we found the expression of the receptor for the neurotransmitter substance P by using a receptor-specific cDNA probe. Glucocorticoid treatment, which profoundly inhibits cellular growth and induces differentiation, results in a rapid decrease of substance P receptor (SPR) gene expression as assessed by Northern blot analysis. Intracellular Ca2+ mobilization was then determined in response to substance P in control cells and glucocorticoid-pretreated cells by dual wavelength spectrophotometry using fura-2 in single cells. Glucocorticoid-mediated down-regulation of substance P receptors resulted in a dose- and time-dependent decrease of the intracellular Ca2+ mobilization stimulated by substance P. In summary, these data indicate that AR42J cells display an amphicrine phenotype with two differentially regulated secretory pathways; during glucocorticoid-induced differentiation, the cells become less sensitive to substance P stimulation as a consequence of reduced gene expression of the substance P receptor.
大鼠胰腺腺泡肿瘤细胞系AR42J被广泛用于研究胰腺腺泡细胞生物学和生物化学。除了有充分记录的外分泌细胞特征外，我们通过免疫荧光和电子显微镜鉴定出，使用神经内分泌（NE）小泡特异性标记物突触素和“蛋白S.V.2”，小NE小泡存在共表达。AR24J细胞储存[3H]GABA，其在钾离子去极化时以钙依赖方式分泌。此外，我们通过使用受体特异性cDNA探针发现了神经递质P物质受体的表达。糖皮质激素处理可显著抑制细胞生长并诱导分化，通过Northern印迹分析评估，结果显示P物质受体（SPR）基因表达迅速降低。然后，使用fura-2通过双波长分光光度法在单细胞中测定对照细胞和糖皮质激素预处理细胞中对P物质的细胞内Ca2+动员情况。糖皮质激素介导的P物质受体下调导致P物质刺激的细胞内Ca2+动员呈剂量和时间依赖性降低。总之，这些数据表明AR42J细胞表现出具有两种不同调节分泌途径的双分泌表型；在糖皮质激素诱导的分化过程中，由于P物质受体基因表达降低，细胞对P物质刺激的敏感性降低。
