Research Resource: A Chromogranin A Reporter for Serotonin and Histamine Secreting Enteroendocrine Cells
Research Resource: A Chromogranin A Reporter for Serotonin and Histamine Secreting Enteroendocrine Cells
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DOI：
10.1210/me.2015-1106
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发表时间：
2015-11-01
影响因子：
--
通讯作者：
Schwartz, Thue W.
中科院分区：
文献类型：
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作者：
Engelstoft, Maja S.;Lund, Mari L.;Schwartz, Thue W.
嗜铬粒蛋白A （Chromogranin A, ChgA）是一种存在于大的致密核分泌囊泡中的酸性蛋白，一般认为在胃肠道的所有肠内分泌细胞中都有表达。在这里，我们描述了一种新的ChgA报告小鼠，ChgA-人源化Renilla reniformis (hr) GFP。hrGFP报告基因是在肾上腺髓质的单胺储存染色质细胞中发现的，而ChgA最初是在肾上腺髓质中发现的。通过免疫组织化学和荧光活化细胞分选纯化细胞的定量PCR分析，hrGFP也在整个胃肠道的肠内分泌细胞中表达，与ChgA表达一致，尽管小肠中的表达与胃和结肠相比较弱。在胃中，hrGFP在几乎所有储存组胺的肠染色质（EC）样细胞中高表达，在大多数储存5 -羟色胺的EC细胞和胃饥饿素细胞中表达较低，在一小部分生长抑素细胞中表达较低，但在胃泌素细胞中不表达。在小肠中，hrGFP报告基因在EC细胞中选择性表达，但在任何储存肽的肠内分泌细胞中均不表达。在结肠中，hrGFP仅在EC细胞中表达，而在储存肽的肠内分泌细胞中不表达。相反，在胰腺中，hrGFP在β细胞、α细胞和一部分胰腺多肽细胞中表达。这表明，胃肠道中的ChgA-hrGFP是一种有效的报告细胞，特别是对于大量尚不清楚单胺储存的肠内分泌细胞。此外，我们的研究结果证实了ChgA作为单胺结合蛋白的潜在功能，促进了肠内分泌细胞中大量单胺的内分泌调节。
Chromogranin A (ChgA) is an acidic protein found in large dense-core secretory vesicles and generally considered to be expressed in all enteroendocrine cells of the gastrointestinal (GI) tract. Here, we characterize a novel reporter mouse for ChgA, ChgA-humanized Renilla reniformis (hr) GFP. The hrGFP reporter was found in the monoamine-storing chromaffin cells of the adrenal medulla, where ChgA was originally discovered. hrGFP also was expressed in enteroendocrine cells throughout the GI tract, faithfully after the expression of ChgA, as characterized by immunohistochemistry and quantitative PCR analysis of fluorescence-activated cell sorting-purified cells, although the expression in the small intestine was weak compared with that of the stomach and colon. In the stomach, hrGFP was highly expressed in almost all histamine-storing enterochromaffin (EC)-like cells, at a lower level in the majority of serotonin-storing EC cells and ghrelin cells, in a small fraction of somatostatin cells, but was absent from gastrin cells. In the small intestine, the hrGFP reporter was selectively, but weakly expressed in EC cells, although not in any peptide-storing enteroendocrine cells. In the colon, hrGFP was exclusively expressed in EC cells but absent from the peptide-storing enteroendocrine cells. In contrast, in the pancreas, hrGFP was expressed in beta-cells, alpha-cells, and a fraction of pancreatic polypeptide cells. It is concluded that ChgA-hrGFP in the GI tract functions as an effective reporter, particularly for the large populations of still poorly characterized monoamine-storing enteroendocrine cells. Furthermore, our findings substantiate the potential function of ChgA as a monoamine-binding protein that facilitates the regulated endocrine secretion of large amounts of monoamines from enteroendocrine cells.