Characterization of a novel functional protein in the pancreatic islet: islet homeostasis protein regulation of glucagon synthesis in α cells.
Characterization of a novel functional protein in the pancreatic islet: islet homeostasis protein regulation of glucagon synthesis in α cells.
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DOI：
10.1097/mpa.0b013e3182222ee5
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发表时间：
2012-01
期刊：
影响因子：
2.9
通讯作者：
Petersen BE
中科院分区：
文献类型：
--
作者：
Oh SH;Darwiche H;Cho JH;Shupe T;Petersen BE
We have identified a novel protein in bone marrow (BM)-derived insulin-producing cells (IPCs). Here we characterize this protein, hereby named Islet Homeostasis Protein (IHoP), in the pancreatic islet. Detection of IHoP mRNA and protein were performed using RT-PCR, immunocytochemistry and in-situ hybridization. IHoP functions were utilizing proliferation, insulin secretion by in vitro assays, and as well as following siRNA protocols for suppression of IHoP. We found that IHoP did not homologue with known pancreatic hormones. IHoP expression was seen in both BM-derived IPCs and isolated pancreatic islets. Immunohistochemistry on pancreatic islet revealed that IHoP localized to the glucagon synthesizing α (alpha)-cells. Inhibition of IHoP by siRNA resulted in the loss of glucagon expression, which induced low blood glucose levels (63–85 mg/dL). Subsequently, cellular apoptosis was observed throughout the islet, including the insulin-producing β (beta)-cells. Islets of pre-onset diabetic patients showed normal expression of IHoP and glucagon; however IHoP was lost upon onset of the disease. These data suggest that IHoP could be a new functional protein in the islet, and may play a role in islet homeostasis.
