Study On The Differentially Expressed Genes In Peripheral Leucocytes And Placenta Tissue Of Gestational Diabetes Mellitus Patients

Gestational diabetes mellitus(GDM) is one of the common complications of pregnancy. However its real patho-physiological process has remained unknown after intensive studies for many years. The possible reason maybe involve insulin resistance; dysfunction of insulin sensibility; disorder of signal transmission ;immune dysfunction and so on. So, the etiology and pathogenesis of GDM are not one gene or protein abnormality, but possibly involve in a series of gene and protein changes. It is necessary to investigate the etiology of GDM thoroughly with new approach which can provide new clue for the study of GDM.Gene expression detection with Gene microarray and real-time PCR technique has been widely applied in recent years, which as a new bio-technology play an important role in the etiology and molecular diagnosis. The isolation of Diabetes mellitus associated gene is the hot spot of current research, which also is key link for the investigation of GDM etiology for molecular level. Till now, little is known for the gene expression change of GDM etiology process, so it is an important step to clarify the gene expression profile during GDM genesis and development stage.Our study presented here is the first using DNA microarray technique and human genome Oligo chip for the detection of placenta tissue and peripheral leucocytes expression profile between normal pregnanciy and GDM, and compare the mRNA expression difference between them.Parallel, large scale, high-throughput analysis of placenta tissue and peripheral leucocytes expression in GDM were proceeded to screen the differentially expressed gene in placenta tissue and peripheral leucocytes from GDM and try to find the internal relationship between differentially expressed gene and etiology of GDM. Real-time PCR technique was used to verify the diffential expression of TNF-αin placenta tissue from GDM.The results of microarray analysis of mRNA in peripheral leucocytes between GDM group and normal pregnancy group indicate: there are 486 differentially expressed genes in Oligo chip, in which 194 up-regulating gens and 292 down-regulating genes. After primary classification with GeneBank research, there are 415 functionally classified genes, 45 unclassified genes, 26 unknown gene expression sequences. Some of the genes have been reported to be associated with GDM, at the same time, we also found some gene never reported before , which have show changes in the peripheral leucocytes.The results of microarray analysis of mRNA in placenta tissue between GDM group and normal pregnancy group indicate: there are 211 differentially expressed genes in Oligo chip, in which 82 up-regulated gens and 129 down-regulated genes. After primary classification with GeneBank research, there are 165 functionally classified genes, 46 unclassified genes and unknown gene expression sequences.The detection and analysis with RT-PCR verified the specificity of the gene-chip result, simultaneously, we validated significantly increased expression of TNF-αgene at placenta from GDM patients. Through the research, we draw the following conclusions:1.The gene expression of placenta tissue and peripheral leucocytes in GDM patients is significantly different from that of normal pregnancy, which indicate GDM is a complicated patho-physiological procedure, involving in cell immunology, metabolism, cell cycle, signal transmission and other extensive and multi-level changes.Insulin resistance may be a key cause of GDM.2.TNF-αgene is up-regulated significantly in the placenta tissue of GDM. It possibly participate in the pathogenesis of GDM, or maybe the result of patho-physiological changes in GDM. TNF-αmay be a predictor of GDM.3. We have undertaken primary research for differentially expressed genes of peripheral leucocytes and placenta from GDM using microarray technique, and found that a part of etiology of GDM were different from Type 2 diabetes in gene level .4. Placenta is a specific tissue in pregnancy process. The differentially expressed genes of placenta tissue may be a specific etiology of GDM.5.Microarray technique is high thoughput and low-waste tool for the screening of differentially expressed gene in placenta tissue and peripheral leucocytes of GDM in a large.On the whole, we have undertaken primary research for differentially expressed genes of GDM using microarray technique, and found a lot of gene associated with etiology and patho-physiology of GDM. Simultaneously, We have verified the feasibility of microarray in the study of GDM . Those differentially expressed genes are related to versatile cell function, which indicate that the generation of GDM are associated with kinds of genetic molecular mechanisms. The consecutive study of these genes in the patho-physiology of GDM can provide new clue for the elucidating of GDM pathogenesis.