title: Effects of glucose, insulin, and supernatant from pancreatic beta-cells on brain-pancreas relative protein in rat hippocampus.
abstract: Brain-pancreas relative protein (BPRP) is a novel protein that mainly expresses in brain and pancreas. In our previous study, we found that various stressors significantly decreased the expression of BPRP in pancreas in vivo, accompanied by changes in insulin and glucose levels, and that expression of BPRP in pancreas also decreased significantly in diabetic rats induced by Streptozocin (STZ). All these findings suggest that BPRP may be a glucose or insulin-sensitive protein. However, how the changes in insulin or glucose levels influence the expression of BPRP in hippocampus requires further study. Here, we investigated the effects of insulin or glucose on the expression of BPRP in primary cultured hippocampal neurons. We supplied hippocampal neurons with glucose, insulin, or supernatant from pancreatic beta-cells, which secrete insulin into the supernatant. Our data showed that insulin had beneficial effect on the viability while no significant effect on the expression of BPRP in hippocampal neurons. On the contrary, 40 mM glucose or free glucose culture significantly decreased the expression of BPRP, while had no significant effect on the viability and apoptosis of hippocampal neurons. Further study showed that levels of insulin in the supernatant collected from pancreatic beta-cells medium changed over days, and that supernatant increased the viability of hippocampal neurons, while it had no obvious effect on the expression of BPRP in hippocampal neurons. These results suggest that BPRP may be a glucose-sensitive protein.
authors.affiliation: Department of Pharmacology, School of Basic Medical Sciences and State Key Laboratory of Natural & Biomimetic Drugs, Peking University Health Science Center, Beijing, China.
authors.forename: Yan-Hua
authors.initials: YH
authors.lastname: Lin
authors.forename: Christel
authors.initials: C
authors.lastname: Westenbroek
authors.forename: Lu
authors.initials: L
authors.lastname: Tie
authors.forename: Ai-Hua
authors.initials: AH
authors.lastname: Liu
authors.forename: He-Ming
authors.initials: HM
authors.lastname: Yu
authors.forename: Gert J Ter
authors.initials: GJ
authors.lastname: Horst
authors.forename: Xue-Jun
authors.initials: XJ
authors.lastname: Li
mesh_terms: D000818:Animals; D017209:Apoptosis / Q000187:drug effects; D002470:Cell Survival / Q000187:drug effects; D002478:Cells, Cultured; D005434:Flow Cytometry; D005947:Glucose / Q000494:pharmacology*; D006624:Hippocampus / Q000187:drug effects / Q000378:metabolism*; D007004:Hypoglycemic Agents / Q000494:pharmacology*; D007328:Insulin / Q000494:pharmacology*; D050417:Insulin-Secreting Cells / Q000187:drug effects / Q000378:metabolism*; D008297:Male; D018613:Microscopy, Confocal; D009419:Nerve Tissue Proteins / Q000096:biosynthesis*; D009474:Neurons / Q000187:drug effects / Q000378:metabolism; D051381:Rats; D017207:Rats, Sprague-Dawley; D013778:Tetrazolium Salts; D013844:Thiazoles
chemical_list: D007004:Hypoglycemic Agents; D007328:Insulin; D009419:Nerve Tissue Proteins; D013778:Tetrazolium Salts; D013844:Thiazoles; C516848:brain-pancreas relative protein, rat; C022616:thiazolyl blue; D005947:Glucose