As one of the most sensitive cells of endoplasmic retieulum stress (ERS), pancreatic β-cells have an a-bundance of endoplasmic reticulum. Fatty acids cause apoptosis of β-cells and might contribute to β-cell loss in type 2 diabetes mellitus via the induction of ERS. Glucose is an amplifier of the ERS response to fatty acid, leading to increased β-cell apoptosis. ERS response mediates glucolipotoxicity-induced β-cell apoptosis.

Objective To construct and to identify eukaryotic expression vector expressing Islet-brain 1(IB1) gene.Methods Total RNA was extracted from human insulinoma.IB1 gene was amplified by PCR from human IB1cDNA library.The eukaryotic expression vector encoding IB1 was constructed by inserting the IB1 cDNA into EcoR I/Kpn I sites of the pEGFP-N1 vector with the green fluorescent.The construct was transfected into RINm5F cell line,screened by G418.The phase contrast fluorescence microscope,flow cytometer,and Western blot were used to identify the recombinant plasmid and transfeced cell line.Results The RT-PCR products for IB1(AA1-280)generated from human insulinoma was 840 bp.Sequence analysis proved the same sequence as published in Gen-Bank.Two bands showed that pEGFP-N1 vector encoding IB1 digested by EcoR I or Kpn I.Western blot showed IB1 gene was expressed in RINm5F cells.Conclusion The recombinant prokaryotic expression plasmid pEGFP-N1-IB1 has been successfully constructed.

We have designed and carried out problem based learning (PBL) pedagogy since 2004. According to clinical eases, students learnt the pathophysiology of heart failure knowledge by themselves. Each group recommen-ded one student to make an oral presentation and wrote a review about heart failure. Preparing clinical cases and group discussions are very important. At the same time we should pay attention to the change in role of the teacher in PBL and cooperation with other disciplines.