Study Of The Polymorphism Of Exon 6 Of PPAR-γ Gene And Of Exon 17 Of INSR Gene In The PCOS

Background and ObjectivePolycystic ovary syndrome (PCOS) is a comman endocrinic disorder disease. It is characterized by hyperandrogenemia, anovulation, infertility and obesity. Its biochemistry character is that insulin resistance, adipose metablic disorder and type 2 diabtes mellitus. The results of epidemic investigations show that PCOS has an obvious trend of family gather. This hints that genetic factors play an important role in the pathogeny. Many investigation have proved genetic factors dertermined the occurrence of PCOS. Peroxisome proliferators-activated receptor-γ(PPAR-γ) is a transcription factor involved in adipogensis and energy metabolism. It is a key factor of thiazolidinediones (TZDs) introduced as insulin-sensitizing agents. Several studies investigated that the polymorphism of PPAR-γgene is involved with obesity and type 2 diabtes mellitus, moreover it is one of clinical of PCOS long-term complications. Taim of this study was to investigate PPAR-γgene and to determine whether it exists polymorphism,and try to find the certain play of PCOS.We hope to provide some theoretical bases on pathogeny seeking and treatment of PCOS.MethodsNnety-six patients with PCOSand fifty-six patients with normal ovulation and fallopian tubal and/or male factor infertility were chosen in the department of assisted repreductive centre in the Second Affiliated hospital of Zhengzhou Universty.. The later was designated the normal control group. In addition, we chose sixteen patients with type 2 diabtes mellitus in the department of endrocrine in the second affiliated hospital of Zhengzhou Universty. The blood sample was collected at the third day of menstrual cycle, The blood sample of at those who with amenorrhea and menopause could be collected at anytime. First, we collect the human genome DNA, secondly we magnify the aim gene by using polymerase chain reaction and restriction fragment length polymorphisms assay (PCR-RFLP) .thirdly PCR product was digested four hours with Pmac I .The PCR products and the digested product were all surveyed on 2.5% agrarose gel electrophoresis and visualized under UV light after ethidium bromide staining.Thus we can determine the polymorphism of exon 6 in PPAR-γgene. The clinical characteristics including BMI (body mass index), FPG (fasting plasma glucose ) , FINS (fasting insulin) , FSH, LH, and T (testosterone) of the subjects were detected and the relationship between the genotype of exon 6 polymorphism and the clinical characteristics were analysed.Results(1) The genotype frequencies of CC, CT/TT in the cases group were 69%, 31%, and in the contral group were 89%, 11% , respectively. The genotype frequencies of CT/TT of PCOS was significantly higher than control (P<0.05);(2) The C and T allele frequenciy of exon 6 in PPAR-γgene in the PCOS group were 77%, 23% and in the control group were 93%, 7% ,respectively. The T allele frequency of exon 6 was significantly higher (P<0.05) in PCOS patients compared with that in control women;(3) The BMI (27.60±4.12 ) of PCOS patients carrying the C→T substitution were higher than that in no substitution (24.61±4.51) (P<0.05). The FINS and HOMA-IR of PCOS patients carrying the C→T substitution were slightly higher than that in no one,but no statistics difference between both groups.Conlusions(1) Han women indeed exist the polymorphism in exon 6 of PPAR-γgene;(2) The base substitution in exon 6 of PPAR-γgene in patients with PCOS was associated with obesity of PCOS;(3) PPAR-γgene may be one of susceptive gene but a essential one of PCOS. Background and ObjectiveInsulin resistance (IR) is one of endocrine metabolism disorders of polycystic ovary syndrome (PCOS) .This is associated with impaired glucose tolerance(IGT) and adipose metabolism disorder of PCOS,ahd it is a main pathologic basis of type 2 diabtes mellitus. Insulin resistance was a common feature in patients with PCOS,and may play a direct role in the development of PCOS, exacerbating and underlying metabolic abnormality. Insulin resistance is a common pathologic state in which target cells fail to respond to ordinary levels of circulating insulin, followed by ompensatory HI. The IR in patients with PCOS will exacerbating the HA and anovulation, increasing the risk of developing type 2DM, hypertension, arteriosclerosis, vascular disease, and carcinoma of endometrium, et al. The mechism resulted this disease is unknown.Previous studies showed that polymorphisms in the INSR gene that induce mild changes in insulin receptor function may contribute to the development of PCOS,especially in the tyrosine domain of INSR, which is critical to the function of the genc. Although many breakthrough progress in mechanism of IR have achieved recently, because IR involve extensive effect agents and complexity of signal transduction system, the precise molecular mechanism of IR was not clearly. The aim of our study is to investigate the association of exon 17 polymorphism in insulin receptor gene and polycystic ovary syndrome .Our study on account of obtained research achievement, questing probable mutation sites from gene constitution, andtry to find the certain mechanism of PCOS IR from the regulation of gene function,hope to establish some new therapeutics for PCOS patients, and to provide sometheoretical bases on prevention and treatment of those severity metabolism complication of PCOS. MethodsFirst, we collect the human genome DNA, secondly we magnify the aim gene by using polymerase chain reaction and restriction fragment length polymorphisms assay (PCR-RFLP) ,thirdly PCR product was digested four hours with Pml I .The PCR products and the digested product were all surveyed on 2.5% agrarose gel electrophoresis and visualized under UV light after ethidium bromide staining. Thus we can determine the polymorphism of exonl7 in INSR gene. The clinical characteristics including BMI ( body mass index ) , FPG ( fasting plasma glucose ), FINS (fasting insulin) and T (testosterone) of the subjects were detected. According to the BMI, T C allele frenquency occurrence of the exon 17 of INSR , insulin resistance and without insulin resistance , hyperandrogenemia and without hyperandrogenemia to divide groups.Compare the difference between related index.Results(1) T allele frenquency occurrence of the exon 17 of INSR in patients with PCOS (41.7%) was higher than that in the countrol (4.3%) (P<0.05).(2) The BMI(25.21±4.47) of T group was lower than that of the C group (P<0.05 ) .(3) The T allele frenquency in the exon 17 of INSR was not different between the insulin resistane group and without insulin resistance group.(4) The T allele frenquency in the exon 17 of INSR was not different between the hyperandrogenemia group and without hyperandrogenemia group.Conlusions(1) Single nucleotide polymorphism of the 17 exon of insulin receptor gene is associated with Chinese patients with PCOS.(2) T allele higher occurrence frenquency is associated with BMI , it is may be one of the charaters of the lean PCOS.(3) T allele higher occurrence frenquency this is not associated with insulin resistance, hyperandrogenemia. So we can think the INSR gene is a susceptive gene but a main one gene of PCOS.