title: Calcium signaling in a genetically engineered human pancreatic β-cell line.
abstract: OBJECTIVE
  The use of primary human β-cells for studying Ca signaling is limited by the scarcity of human pancreatic islets. Rodent insulinoma cell lines are widely used, but it is difficult to extrapolate results obtained from rodent cells to human. Recently, a genetically engineered human β-cell line EndoC-BH1 has been developed. We have examined whether the EndoC-BH1 cells could be used as a model for studying Ca signaling in the β-cells.
  
  
  METHODS
  We used microscope-based fluorometry to measure cytoplasmic-free Ca concentration from fura-2-loaded single EndoC-BH1 cells cultured on glass cover slips. Ca responses to different agonists of insulin secretion were studied. Insulin secretion was measured by radioimmunoassay.
  
  
  RESULTS
  EndoC-BH1 cells secreted insulin in response to glucose in a dose-dependent manner, and the secretion was enhanced by GLP-1 (glucagon-like peptide 1). Glucose, potassium chloride, carbachol, L-arginine, and tolbutamide increased cytoplasmic-free Ca concentration in the EndoC-BH1 cells. We found that GLP-1 was essential for Ca response to glucose and tolbutamide.
  
  
  CONCLUSIONS
  We concluded that the EndoC-BH1 cells can be used as model cells to study Ca signaling and stimulus-secretion coupling in the human β-cells.
authors.affiliation: From the *Department of Clinical Science and Education, Södersjukhuset, Karolinska Institutet, Stockholm; Departments of †Molecular Medicine and Surgery, and ‡Endocrinology, Metabolism, and Diabetes, Karolinska University Hospital Solna, Stockholm; and §Department of Internal Medicine, Uppsala University Hospital, Uppsala, Sweden.
authors.forename: Kalaiselvan
authors.initials: K
authors.lastname: Krishnan
authors.forename: Zuheng
authors.initials: Z
authors.lastname: Ma
authors.forename: Anneli
authors.initials: A
authors.lastname: Björklund
authors.forename: Md Shahidul
authors.initials: MS
authors.lastname: Islam
mesh_terms: D020013:Calcium Signaling / Q000187:drug effects; D045744:Cell Line, Tumor; D004305:Dose-Response Relationship, Drug; D005456:Fluorescent Dyes; D005470:Fluorometry; D016257:Fura-2; D005818:Genetic Engineering; D005947:Glucose / Q000494:pharmacology; D006801:Humans; D007328:Insulin / Q000378:metabolism; D000078790:Insulin Secretion; D050417:Insulin-Secreting Cells / Q000187:drug effects / Q000378:metabolism*; D007700:Kinetics; D008564:Membrane Potentials
chemical_list: D005456:Fluorescent Dyes; D007328:Insulin; D005947:Glucose; D016257:Fura-2