| Diabetes is a disease with high death rate, following cancer and cardiovascular disorder, and is harmful to human heath. There are still no complete explanations of the mechanism of diabetes, so the discovery of diabetes therapy and mechanism become the focus of researchers. The Chinese traditional drug, island transplantation and gene therapy are of high value in diabetes therapy. We will study the function of PDX-1 in inducing liver cell to pancreatic cell in this paper .we hope this study can be used as a theory basis for diabetes therapy. As far as we known, there are still no reports of this study in domestic. This study will give a new road to diabetes therapy. Type I and type II diabetes are caused by lack of insulin which are caused by abnormal increase of island cell apoptosis and decrease of cell. Pancreatic duodenal homeobox-1,PDX-1,as a important transcription factor in pancreas development, directs the normal development of pancreas and can regulate a number of genes involved in maintaining beta-cell identity and function. These include insulin, glucose transporter 2(GLUT-2), glucokinase and islet amyloid polypeptide. It also regulates somatostatin gene expression in islet delta-cell and in the developing brain. The ability of PDX-1 to activate gene transcription in a tissue specific manner is dependent on its capacity to interact with other transcription factors. For example, in insulin gene promoter, functional PDX-1 DNA-binding sites are arranged in close proximity to E boxes that bind a heterodimeric complex of the ubiquitously expressed bHLH protein E47(also known as Pan-1) and its neuroendocrine specific bHLH partner NeuroD1. Another study indicates that there are two waves of expression of PDX-1 in the developing pancreas. In the endoderm of gut PDX-1 defines a region that will form the pancreas. In the second wave,PDX-1, together with Nkx6.1, NeuroD1,are the differentiation factors of beta-cell. In the recent years, studies have indicated that injection of PDX-1 can turn the mature liver cell or the fetal liver cell into islet cell to cure diabetes. This gives a new way to the work of diabetes therapy. Based on the former study, we want to know whether PDX-1 can be useful in diabetes therapy, whether injection of PDX-1 can turn liver cell to pancreatic cell, and whether different species PDX-1 can be of same use. This paper will include the following contents:(1)clone the human, murine, rat PDX-1 encoding region into pcDNA3 Eukaryotic expression vector and compare the three sequences. (2) induce the murine fetal matrix cell into pancreatic cell.(3) get a fusion vector of PDX-1 and VP16.(4) single diabetes therapy always has not obvious results or causes dependence and tolerance on drug. So we will study the effect of Chinese traditional drug on STZ inducing diabetes animal model All the work and results are summarized below: 1. Clone and analyze the coding region of PDX-1 and construct the eukaryotic expression vector We analyzed the sequence of PDX-1, designed the primers, cloned the human, murine, rat PDX-1 gene from duodenum by RT-PCR, and got the Eukaryotic expression vector pcDNA3-PDX-1. The correct of the gene was confirmed by sequencing and blast. We compared and analyzed their homology, conservative region, function region and chromosome location. We found that human PDX1 shares 83% identity with mice and rats at nucleic acid level, shares 88% with mice and 89% with rats at amino acid level. We also found the 146-206 region of PDX-1 is highly homologous between mammals and this region, as a DNA-binding site, is essential to pancreatic development. The FPWMK region upstream the homologous region can interact with PBX to direct the normal differentiation of pancreatic secretion cells.2. Induce the murine matrix cells into pancreatic cells We transfected the immortalized murine fetal liver matrix cells with pmPDX-1 and pcDNA3, and detected the pancreas specific genes by RT-PCR. We found the expression of two genes on mRNA level: insulin secreted b...
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