title: The ryanodine receptor is expressed in human pancreatic acinar cells and contributes to acinar cell injury.
abstract: Physiological calcium (Ca(2+)) signals within the pancreatic acinar cell regulate enzyme secretion, whereas aberrant Ca(2+) signals are associated with acinar cell injury. We have previously identified the ryanodine receptor (RyR), a Ca(2+) release channel on the endoplasmic reticulum, as a modulator of these pathological signals. In the present study, we establish that the RyR is expressed in human acinar cells and mediates acinar cell injury. We obtained pancreatic tissue from cadaveric donors and identified isoforms of RyR1 and RyR2 by qPCR. Immunofluorescence staining of the pancreas showed that the RyR is localized to the basal region of the acinar cell. Furthermore, the presence of RyR was confirmed from isolated human acinar cells by tritiated ryanodine binding. To determine whether the RyR is functionally active, mouse or human acinar cells were loaded with the high-affinity Ca(2+) dye (Fluo-4 AM) and stimulated with taurolithocholic acid 3-sulfate (TLCS) (500 μM) or carbachol (1 mM). Ryanodine (100 μM) pretreatment reduced the magnitude of the Ca(2+) signal and the area under the curve. To determine the effect of RyR blockade on injury, human acinar cells were stimulated with pathological stimuli, the bile acid TLCS (500 μM) or the muscarinic agonist carbachol (1 mM) in the presence or absence of the RyR inhibitor ryanodine. Ryanodine (100 μM) caused an 81% and 47% reduction in acinar cell injury, respectively, as measured by lactate dehydrogenase leakage (P < 0.05). Taken together, these data establish that the RyR is expressed in human acinar cells and that it modulates acinar Ca(2+) signals and cell injury.
authors.affiliation: Departments of Pediatrics and.
authors.forename: Christopher M
authors.initials: CM
authors.lastname: Lewarchik
authors.affiliation: Departments of Pediatrics and.
authors.forename: Abrahim I
authors.initials: AI
authors.lastname: Orabi
authors.affiliation: Departments of Pediatrics and.
authors.forename: Shunqian
authors.initials: S
authors.lastname: Jin
authors.affiliation: Departments of Pediatrics and.
authors.forename: Dong
authors.initials: D
authors.lastname: Wang
authors.affiliation: Department of Neurological Surgery, Comprehensive Cancer Center, Wexner Medical Center, Ohio State University, Columbus, Ohio;
authors.forename: Kamaldeen A
authors.initials: KA
authors.lastname: Muili
authors.affiliation: Departments of Pediatrics and.
authors.forename: Ahsan U
authors.initials: AU
authors.lastname: Shah
authors.affiliation: Departments of Pediatrics and.
authors.forename: John F
authors.initials: JF
authors.lastname: Eisses
authors.affiliation: Departments of Pediatrics and.
authors.forename: Adeel
authors.initials: A
authors.lastname: Malik
authors.affiliation: Institute of Cellular Therapeutics, Allegheny General Hospital, Pittsburgh, Pennsylvania.
authors.forename: Rita
authors.initials: R
authors.lastname: Bottino
authors.affiliation: Dental Medicine, Children's Hospital of Pittsburgh of UPMC and the University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania;
authors.forename: Thottala
authors.initials: T
authors.lastname: Jayaraman
authors.affiliation: Departments of Pediatrics and sohail.husain@chp.edu.
authors.forename: Sohail Z
authors.initials: SZ
authors.lastname: Husain
mesh_terms: D061354:Acinar Cells / Q000187:drug effects / Q000378:metabolism*; D000818:Animals; D002118:Calcium / Q000378:metabolism; D002217:Carbachol / Q000494:pharmacology; D016923:Cell Death; D006801:Humans; D007770:L-Lactate Dehydrogenase / Q000378:metabolism; D051379:Mice; D010179:Pancreas / Q000166:cytology / Q000378:metabolism*; D020033:Protein Isoforms / Q000235:genetics / Q000378:metabolism; D012333:RNA, Messenger / Q000235:genetics / Q000378:metabolism; D012433:Ryanodine / Q000494:pharmacology; D019837:Ryanodine Receptor Calcium Release Channel / Q000235:genetics / Q000378:metabolism*; D013658:Taurolithocholic Acid / Q000031:analogs & derivatives / Q000494:pharmacology
chemical_list: D020033:Protein Isoforms; D012333:RNA, Messenger; D019837:Ryanodine Receptor Calcium Release Channel; C066776:taurolithocholic acid 3-sulfate; D012433:Ryanodine; D013658:Taurolithocholic Acid; D002217:Carbachol; D007770:L-Lactate Dehydrogenase; D002118:Calcium
keywords: acinar cell; acinar cell injury; ryanodine receptor; tritiated ryanodine binding