Proteomic and transcriptomic analysis for streptozotocin‐induced diabetic rat pancreas in response to fungal polysaccharide treatments

Abstract

In an attempt to search for novel biomarkers for monitoring diabetes prognosis, we examined the influence of the hypoglycemic fungal extracellular polysaccharides (EPS) on the differential change in pancreatic proteome and transcriptome in streptozotocin (STZ)-induced diabetic rats using 2-DE-based protein mapping and oligonucleotide microarray analysis. The 2-DE system separated more than 2000 individual spots, demonstrating that 34 proteins out of about 500 matched spots were differentially expressed. A total of 22 overexpressed and 12 underexpressed proteins in 2-DE map were observed (p<0.05) between the healthy and diabetic rats, of which 26 spots were identified by PMF analysis. Of these, significant down regulation of carbonyl reductase (Cbr), hydroxymethylglutaryl-CoA synthase (HMGCS), and putative human mitogen-activated protein kinase activator with WD repeats-binding protein (MAWDBP) in diabetic pancreas were reported for the first time in this study. When treated with EPS, all these four proteins were reverted to normal levels. The microarray analysis revealed that 96 out of 1272 genes were down- or up-regulated in the diabetic rats and the altered transcript levels of many of these genes were reversed after EPS treatment. In particular, ROS generation in rat islets was significantly increased after STZ treatment, thereafter EPS treatment was likely to play a preventive role in beta-cell destruction mediated by STZ. Taken together, EPS may act as a potent regulator of gene expression for a wide variety of genes in diabetic rats, particularly in antioxidative stress, insulin biosynthesis, and cell proliferation.

Unraveling pancreatic islet biology by quantitative proteomics

“…After electrophoresis, the proteins on the gel are visualized and quantified by gel staining, such as Coomassie Brilliant Blue staining and SYPRO Ruby staining, and protein spots of interest are typically excised, digested and then identified using MS. A 2D-DIGE that utilizes fluorescent tags (Cy2, Cy3 and Cy5) to analyze multiple samples simultaneously can further improve protein quantification by 2DE [27,32]. While 2DE is still one of the commonly applied proteomic technologies in diabetes research [33–36], the technique has several inherent limitations, such as the laborious process of identifying proteins from individual gel spots by MS and the low sensitivity for detecting low-abundance proteins, as well as proteins with extreme molecular weight, isoelectric point or hydrophobicity.…”

Gene Expression Profiling of Adipose Tissues in Obesity Susceptible and Resistant Rats under a High Fat Diet

“…In each group the gene expression profiles of adipose tissues from normal, OP, and OR rats were generated using the Illumina RatRef-12 Bead Chip, which includes 21,290 probe sets representing >11,360 known genes and 6,856 expressed sequence tags with unknown functions. In this study, the PANTHER classification system (http:/ /www.pantherdb.org) was used for classification of genes according to their functions [25]. In brief, gene lists can be uploaded to the size and analyzed relative to molecular functions, biological processes, and pathways.…”

Alterations in Pancreatic Protein Expression in STZ-Induced Diabetic Rats and Genetically Diabetic Mice in Response to Treatment with Hypoglycemic Dipeptide Cyclo (His-Pro)

“…In-gel digestion was performed using modified porcine trypsin according to the methods outlined by our previous method [27]. Each of the silver-stained gels was washed with 50% acetonitrile to remove SDS, salts, and the stain.…”

“…A series of proteomic studies have been performed on both whole pancreatic tissues as well as isolated islets of Langerhans from mice [21,22] and rats [14][15][16][17][18][19][20][21][22][23][24][25][26][27]. However, those pancreatic proteome profiling studies were not aimed to investigate proteomic alterations in response to treatment with anti-diabetic agents or other environmental stimuli.…”