Peptide transporter 1 (PepT1) is a transporter responsible for absorbing dipeptide and tripeptide in enterocytes and is upregulated by dipeptide in mammals. It has not been certain whether intestinal PepT1 expression is responsive to dipeptides in chickens because of the lack of in vitro study using the cultured enterocytes. This study established a primary culture model of chicken intestinal epithelial cells (IECs) in two-dimensional monolayer culture using collagen gel by which the response of chicken PepT1 gene expression to dipeptide stimuli was evaluated. The cultured chicken IECs showed the epithelial-like morphology attached in a patch-manner and exhibited positive expression of cytokeratin and epithelial cadherin, specific marker proteins of epithelial cells. Moreover, the chicken IECs exhibited the gene expression of intestinal cell type-specific marker, villin1, mucin 2, and chromogranin A, suggesting that the cultured IECs were composed of enterocytes as well as goblet and enteroendocrine cells. PepT1 gene expression was significantly upregulated by synthetic dipeptide, glycyl-l-glutamine, in the cultured IECs. From the results, we herein suggested that dipeptide is a factor upregulating PepT1 gene expression in chicken IECs.

中文翻译：

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二肽对肠肽转运蛋白 1 基因表达的影响：使用原代培养的鸡肠上皮细胞进行评估

肽转运蛋白 1 (PepT1) 是一种负责吸收肠细胞中二肽和三肽的转运蛋白，在哺乳动物中被二肽上调。由于缺乏使用培养的肠细胞的体外研究，尚不确定肠道 PepT1 表达是否对鸡的二肽有反应。本研究使用胶原凝胶在二维单层培养中建立鸡肠上皮细胞 (IEC) 的原代培养模型，通过该模型评估鸡 PepT1 基因表达对二肽刺激的反应。培养的鸡 IECs 显示出以贴片方式附着的上皮样形态，并表现出细胞角蛋白和上皮钙粘蛋白（上皮细胞的特异性标记蛋白）的阳性表达。而且，鸡 IECs 表现出肠细胞类型特异性标志物 villin1、粘蛋白 2 和嗜铬粒蛋白 A 的基因表达，表明培养的 IECs 由肠细胞以及杯状细胞和肠内分泌细胞组成。在培养的 IEC 中，PepT1 基因表达被合成二肽甘氨酰-l-谷氨酰胺显着上调。根据结果​​，我们在此表明​​二肽是上调鸡 IEC 中 PepT1 基因表达的一个因素。