1. Cholic acid activation of GPBAR1 does not induce or exacerbate acute pancreatitis but promotes exocrine pancreatic secretion.
- Author
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An P, Fan Y, Wang Q, Huang N, Chen H, Sun J, Du Z, Zhang C, and Li J
- Subjects
- Animals, Male, Rats, Acinar Cells metabolism, Acinar Cells drug effects, Acinar Cells pathology, Rats, Sprague-Dawley, Cyclic AMP metabolism, Calcium metabolism, Calcium Signaling drug effects, Receptors, G-Protein-Coupled metabolism, Receptors, G-Protein-Coupled genetics, Pancreatitis metabolism, Pancreatitis chemically induced, Pancreatitis pathology, Pancreas, Exocrine metabolism, Pancreas, Exocrine drug effects, Pancreas, Exocrine pathology, Cholic Acid metabolism, Cholic Acid pharmacology
- Abstract
Obstruction of bile ducts due to gallstones can lead to biliary acute pancreatitis (BAP). According to Perides et al., G protein-coupled bile acid receptor-1 (GPBAR1) mediates BAP. However, Zi's findings suggest that GPR39, rather than GPBAR1, mediates TLCAS-induced increases in cytosolic calcium and acinar cell necrosis, casting doubt on the role of GPBAR1 in BAP. Numerous G protein-coupled receptors on pancreatic acinar cells utilize Ca
2+ and cyclic adenosine monophosphate (cAMP) as second messengers to manage pancreatic exocrine secretion, with significant cross-talk between these signals. The primary bile acid cholic acid (CA) and its conjugated forms are predominant in the human gallbladder. This study aimed to clarify the role and physiological significance of GPBAR1 by investigating the physiological and pathological effects of CA activation on GPBAR1 in pancreatic acinar cells. Isolated rat pancreatic acinar cells were treated with CA and CCK in vitro to observe the effect of CA-induced cAMP signaling on CCK-induced physiological and pathological calcium signaling. In vivo evaluations involved reverse biliopancreatic duct injections of 5 % sodium taurocholate (STC) or 5 % CA in rats. CA induced intracellular cAMP signaling in a concentration-dependent manner without increasing the intracellular Ca2+ concentration. CA did not independently cause calcium overload or enzyme activation, nor did it exacerbate calcium overload or enzyme activation from high-dose CCK. Reverse biliopancreatic duct injections of 5 % CA did not cause acute pancreatitis in the rats. Transcriptomic analysis revealed that 50 μM CA induced changes in gene expression related to protein synthesis in the endoplasmic reticulum and ribosomes. Furthermore, 50 μM CA accelerated the calcium waves and increased the enzyme secretion induced by CCK. GPBAR1 was found on the basolateral membrane in rat pancreatic tissue rather than near the apical region of acinar cells. GPBAR1 activation is not crucial for BAP activity but may play a role in bile acid regulation of pancreatic exocrine secretion, suggesting that GPBAR1 is a potential therapeutic target for pancreatic exocrine insufficiency., Competing Interests: Declaration of competing interest The authors declare the following financial interests/personal relationships which may be considered as potential competing interests: Jun Li reports financial support was provided by National Natural Science Foundation of China. Jun Li reports financial support was provided by Project of Shaanxi Administration of Traditional Chinese Medicine. Jun Li reports financial support was provided by Xi'an Science and Technology Program. Yudan Fan and Peng An reports financial support was provided by Key Research and Development Program of Shaanxi Province of China. If there are other authors, they declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 The Authors. Published by Elsevier Inc. All rights reserved.)- Published
- 2024
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