CELLULAR-DISTRIBUTION OF ISOFORMS OF PROTEIN-KINASE-C (PKC) IN PANCREATIC ACINI
CELLULAR-DISTRIBUTION OF ISOFORMS OF PROTEIN-KINASE-C (PKC) IN PANCREATIC ACINI
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DOI：
10.1016/0167-4889(95)00120-0
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发表时间：
1995-11-30
影响因子：
5.1
通讯作者：
GARDNER, JD
中科院分区：
文献类型：
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作者：
BASTANI, B;YANG, LY;GARDNER, JD
在之前的研究中（Biochim. Biophys. Acta 1224（1994）127-138），我们使用定量免疫印迹分析发现大鼠胰腺腺泡具有PKC-α、δ、ε和zeta四种不同的亚型。佛波酯12-O-十四烷酰基佛波13-乙酸酯（TPA）引起每个亚型从细胞质易位到膜部分。CCK-8增加甘油二酯（DAG），并引起PKC-δ和PKC-β易位，但不引起PKC-α或PKC-zeta易位。CCK受体拮抗剂L-364，718可阻断和逆转CCK-8对DAG和PKC-δ、PKC-β转位的影响。为探讨PKC不同亚型在大鼠胰腺组织中的分布差异，我们采用免疫细胞化学方法，观察了PKC不同亚型在完整胰腺及胰腺腺泡中的细胞分布。在完整胰腺中，PKC-α和PKC-δ在胰岛细胞中检测到，但在导管或腺泡细胞中未检测到。在腺泡细胞的顶端区域检测到PKC-β，并且在腺泡细胞的腔表面和从腺泡延伸的小管上检测到PKC-zeta。在胰岛中未检测到PKC-β和PKC-zeta。在胰腺腺泡中，在污染制备物的胰岛或胰岛碎片中检测到PKC-α和PKC-δ，但在腺泡细胞中未检测到。PKC-β在腺泡细胞的顶端区域被检测到，并且加入1 μ M TPA或1 μ M CCK-8加重了免疫染色，但没有改变其细胞分布。L-364，718逆转CCK-8引起的免疫染色变化。PKC-ζ在腺泡细胞的腔表面上被检测到。TPA，而不是CCK-8或CCK-8后的L-364，718，增加腺泡细胞的管腔表面染色的腺泡数量。因此，本研究结果表明，不同的PKC亚型分布不同，在大鼠胰腺和不同的分布模式可以解释，至少部分，CCK-8的不同反应。
As in a previous study (Biochim. Biophys. Acta 1224 (1994) 127-138), we used quantitative immunoblot analysis and found that rat pancreatic acini possess four different isoforms of PKC-alpha, delta, epsilon and zeta. The phorbol ester 12-O-tetradecanoyl phorbol 13-acetate (TPA) caused translocation of each isoform from the cytosol to the membrane fraction. CCK-8 increased diacylglycerol (DAG) and caused translocation of PKC-delta and PKC-epsilon but not that of PKC-alpha or PKC-zeta. L-364,718, a CCK receptor antagonist, prevented as well as reversed the effects of CCK-8 on DAG and on translocation of PKC-delta and PKC-epsilon. To explore the possibility that different isoforms of PKC might have different distributions in rat pancreas, we used immunocytochemistry to determine the cellular distribution of different isoforms of PKC in intact pancreas as well as pancreatic acini. In intact pancreas, PKC-alpha and PKC-delta were detected in islet cells but not in duct or acinar cells. PKC-epsilon was detected in the apical region of acinar cells and PKC-zeta was detected over the luminal surfaces of acinar cells and the ductules that extend from the acinus. Neither PKC-epsilon nor PKC-zeta was detected in islets. In pancreatic acini PKC-alpha and PKC-delta were detected in islets or fragments of islets that contaminated the preparation but were not detected in acinar cells. PKC-epsilon was detected in the apical region of acinar cells and adding 1 mu M TPA or 1 mu M CCK-8 accentuated the immunostaining but did not alter its cellular distribution. L-364,718 reversed the changes in immunostaining caused by CCK-8. PKC-zeta was detected over the luminal surface of the acinar cells. TPA, but not CCK-8 or CCK-8 followed by L-364,718, increased the number of acini that showed staining of the luminal surfaces of acinar cells. Thus, the present results demonstrate that different isoforms of PKC are distributed differently in rat pancreas and that the different patterns of distribution can explain, at least in part, the different responses to CCK-8.