Reports of research work funded by grants prior to 2012
University of Otago Wellington, School of Medicine and Health Sciences
Identification of Protein Profile Differences in the Isolated Segments of Bowel Following Gastric Bypass Surgery in a Zucker Diabetic Fatty Rat Model of Obese Type 2 Diabetes Mellitus
J Foo and M Hayes
Department of Pathology and Molecular Medicine
A grant of $10,000 was kindly given by the Foundation towards a project primarily aimed at identifying the proteins which are altered in rat duodenal tissues by gastric bypass surgery, which may be involved in the process by which this surgery resolves type 2 diabetes. We have previously shown from our work that gastric bypass performed in Zucker Diabetic Fatty rats (ZDF rats) does indeed resolve the diabetes in this animal model, within days of surgery, in the same way as our group has seen resolution of type 2 diabetes in severely obese diabetic subjects undergoing gastric bypass surgery. Whereas it had been our intention to conduct this work using 2D-DIGE followed by MALDI-TOF mass spectrometry, because of limitation on funding, and our recent success in another project with cDNA arrays in liver tissue before and after gastric bypass surgery, it was decided in collaboration with Dr Bill Jordan from Victoria University School of Biological Sciences, to use the funds along with others obtained from the Surgical Trust to fund cDNA analysis work on the duodenal tissue obtained from ZDF rats. Sham operated animals would serve as controls (still diabetic) and animals sacrificed seven days after gastric bypass would act as the study group (diabetes resolved).
We initially proposed using Illumina rat arrays for this work but Illumina discontinued production of this product late 2011. We subsequently decided to use Affimetrix rat exon arrays which unfortunately are several times more expensive, which limits the number of comparisons which can be made. So far we have extracted both protein and mRNA from duodenal epithelial tissue and sent two sets of RNA to our collaborator, Dr Eric Hoffman at the National Children’s Medical Center in Washington DC, neither of which have proved of sufficient quality for use in the assays. We are now in the process of sending rat duodenal tissue directly to our collaborator for processing using an automated RNA extraction machine which has a better chance of extracting viable total RNA for the assays. Providing good quality RNA can be obtained, the cDNA arrays will be carried out and we expect to obtain critically useful information regarding duodenal proteins which change following gastric bypass in ZDF rats and which may be responsible or at least associated with the resolution of type 2 diabetes which follows this operation. This will then allow further work as described in our original application to proceed, when further funds are available.