Characterization of crustacean cardioactive peptide as a novel insect midgut factor: isolation, localization, and stimulation of alpha-amylase activity and gut contraction.
Characterization of crustacean cardioactive peptide as a novel insect midgut factor: isolation, localization, and stimulation of alpha-amylase activity and gut contraction.
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DOI：
10.1210/en.2004-0722
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发表时间：
2004-12
期刊：
影响因子：
4.8
通讯作者：
T. Sakai;H. Satake;H. Minakata;M. Takeda
中科院分区：
文献类型：
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作者：
T. Sakai;H. Satake;H. Minakata;M. Takeda
中肠在昆虫的取食行为中起着重要作用，它被认为是由包括神经肽在内的多种因素控制的。在本研究中，我们确定了一种神经肽甲壳动物心脏活性肽（CCAP）作为一种新的昆虫肠道因子。CCAP是从美洲大蠊的中肠中分离得到的。RT-PCR检测到蟑螂CCAP mRNA在腹神经索和中肠的表达，揭示了CCAP在中肠和中枢神经系统中的产生。此外，我们观察到CCAP基因的表达在中肠内分泌细胞的原位杂交，免疫组化分析表明，CCAP分布在周围的内分泌细胞的侧面。在向中肠添加CCAP后观察到α-淀粉酶活性的升高。这些结果表明CCAP以旁分泌方式参与碳水化合物的消化。原位杂交和免疫组织化学也显示CCAP表达在沉积神经节的细胞体中，其支配中肠肌肉层但不支配上皮，表明CCAP在沉积神经节中产生，然后通过神经纤维运输到肌肉层。此外，发现CCAP以剂量依赖性方式刺激前肠、中肠和后肠的收缩。总之，我们的数据表明CCAP作为神经肽和新的中肠因子在调节肠道组织中的多功能性。
The midgut, which plays a major role in the feeding behavior of insects, is believed to be controlled by various factors including neuropeptides. In the present study, we identified a neuropeptide crustacean cardioactive peptide (CCAP) as a novel gut factor in insects. CCAP was isolated from the midgut of the cockroach, Periplaneta americana. RT-PCR analysis detected the expression of the cockroach CCAP mRNA in the ventral nerve cord and the midgut, revealing the production of CCAP in the midgut as well as the central nervous system. Moreover, we observed expression of the CCAP gene in the endocrine cells of the midgut by in situ hybridization, and immunohistochemical analysis showed that CCAP was distributed around the lateral surfaces of the endocrine cells. Elevation of alpha-amylase activity was observed upon addition of CCAP to the midgut. These results suggest that CCAP is involved in digestion of carbohydrate in a paracrine manner. In situ hybridization and immunohistochemistry also revealed CCAP expression in the cell bodies of the ingluvial ganglion, which innervates the midgut muscle layer but not the epithelium, indicating that CCAP is produced in the ingluvial ganglion and then transported to the muscle layer through nerve fibers. Furthermore, CCAP was found to stimulate the contraction of the foregut, midgut, and hindgut in a dose-dependent manner. Taken together, our data indicate the multifunctionality of CCAP in the regulation of gut tissues as both a neuropeptide and a novel midgut factor.