title: Persistent glucose transporter expression on pancreatic beta cells from longstanding type 1 diabetic individuals.
abstract: BACKGROUND
  Recent reports have established the notion that many patients with longstanding type 1 diabetes (T1D) possess a remnant population of insulin-producing beta cells. It remains questionable, however, whether these surviving cells can physiologically sense and respond to glucose stimuli.
  
  
  METHODS
  Frozen pancreatic sections from non-diabetic donors (n=8), type 2 diabetic patients (n=4), islet autoantibody-positive non-diabetic patients (n=3), type 1 diabetic patients (n=10) and one case of gestational diabetes were obtained via the network for Pancreatic Organ Donors. All longstanding T1D samples were selected based on the detection of insulin-producing beta cells in the pancreas by immunohistochemistry. RNA was isolated from all sections followed by cDNA preparation and quantitative real-time polymerase chain reaction for insulin, glucose transporter 1 (GLUT1), GLUT2 and GLUT3. Finally, immunofluorescent staining was performed on consecutive sections for all four of these markers and a comparison was made between the expression of GLUT2 in humans versus NOD mice.
  
  
  RESULTS
  In contrast to islets from the most widely used T1D model, the NOD mouse, human islets predominantly express GLUT1 and, to a much lesser extent, GLUT3 on their surface instead of GLUT2. Relative expression levels of these receptors do not significantly change in the context of the various (pre-)diabetic conditions studied. Moreover, in both species preservation of GLUT expression was observed even under conditions of substantial leucocyte infiltration or decades of T1D duration.
  
  
  CONCLUSIONS
  These data suggest that despite being subjected to multiple years of physiological stress, the remaining beta-cell population in longstanding T1D patients retains a capacity to sense glucose via its GLUTs.
authors: Type 1 Diabetes Center, The La Jolla Institute for Allergy and Immunology, La Jolla, CA 92037, USA.
authors: Ken T
authors: KT
authors: Coppieters
authors: Anna
authors: A
authors: Wiberg
authors: Natalie
authors: N
authors: Amirian
authors: Thomas W
authors: TW
authors: Kay
authors: Matthias G
authors: MG
authors: von Herrath
mesh_terms: D000818:Animals; D003922:Diabetes Mellitus, Type 1 / Q000378:metabolism*; D003924:Diabetes Mellitus, Type 2 / Q000378:metabolism; D051246:Glucose Transport Proteins, Facilitative / Q000096:biosynthesis*; D051272:Glucose Transporter Type 1 / Q000096:biosynthesis; D051273:Glucose Transporter Type 2 / Q000096:biosynthesis; D006801:Humans; D050417:Insulin-Secreting Cells / Q000378:metabolism*; D051379:Mice; D016688:Mice, Inbred NOD
chemical_list: D051246:Glucose Transport Proteins, Facilitative; D051272:Glucose Transporter Type 1; D051273:Glucose Transporter Type 2; C495680:SLC2A2 protein, human; C495682:Slc2a2 protein, mouse