Calcium-sensing receptor is not expressed in the absorptive enterocytes of weaned piglets. (16th March 2022) - Zhao, Xiaoya
Abstract: The calcium-sensing receptor (CaSR ) is a kokumi receptor that plays an essential role in nutrient sensing and animal physiology, growth, and development. Pig CaSR (pCaSR ) was identified and characterized in the intestine. However, further research is still needed to confirm the expression of CaSR in the epithelial cells isolated from weaned piglets. In this study, primary enterocytes were isolated and characterized from the ileum of weaned piglets by the Weiser distended intestinal sac technique and fluorescence-activated cell sorting (FACS ) based on sucrase-isomaltase (SI ) as an enterocyte-specific marker. The expression of CaSR was investigated in both primary enterocytes and the intestinal porcine enterocyte cell line-j2 (IPEC-J2 ) by droplet digital polymerase chain reaction (ddPCR ), immunofluorescence staining, and Western blotting. Results demonstrated that porcine enterocytes could be obtained using FACS with the SI as the enterocyte-specific marker and that pCaSR is not expressed in both porcine ileal enterocytes and IPEC-J2 cells, which specifically identified the expression of pCaSR in ileal enterocytes with sensitive and specific approaches. Lay Summary: The calcium-sensing receptor (CaSR ) has been identified as a nutrient sensor along the gastrointestinal tract and plays a pivotal role in food digestion, nutrient absorption, and energy metabolism. Hence, elucidating the expression pattern of pig CaSR (pCaSR ) in the intestinal segments, especially in the absorptive enterocytes, could reveal the significance of pCaSR in nutrient sensing in the gastrointestinal tract. In the present work, after isolating enterocytes from the ileum of weaned piglets, we investigated the expression of pCaSR in porcine enterocytes through a combination of biological tools at both gene and protein expression levels. Data observed in the current study revealed that porcine enterocytes could be obtained by using cell sorting with a digestive enzyme (sucrase-isomaltase) as the enterocyte-specific marker. Plus, the pCaSR is not expressed in either isolated porcine ileal enterocytes or the intestinal porcine enterocyte cell line-j2 (IPEC-J2). Abstract : We isolated enterocytes from the ileum of weaned piglets by using sucrase-isomaltase as an enterocyte-specific marker and investigated the expression of CaSR in porcine primary enterocytes and the enterocyte-like intestinal porcine epithelial cell line-j2 (IPEC-J2). Our findings suggested no expression of pCaSR in both porcine ileal enterocytes and IPEC-J2 cells.