Novel Genetic Variants of PPARγ2 Promoter in Gestational Diabetes Mellitus and its Molecular Regulation in Adipogenesis.

Peroxisome proliferator-activated receptor γ2 (PPARγ2) is a nuclear hormone receptor of ligand-dependent transcription factor with a key role in adipogenesis and insulin sensitization in diabetes mellitus. In this study, we investigated genetic variants in PPARγ2 promoter, its association with gestational diabetes mellitus (GDM), and its molecular regulation. PPARγ2 promoter and start codon (-2,091 to +82 bp) from 400 pregnancies with GDM and 400 gestational-age matched control pregnancies were sequenced. Association and linkage disequilibrium of the identified polymorphisms with GDM was determined. ChIP-seq, gene silencing, and dual-luciferase reporter assays were performed to confirm transcription factor binding sites and promoter activity of the variants. Transfection experiments were carried out to determine the effects of variants on gene expression and adipogenesis. Among 15 variants identified, 7 known variants were not significantly associated with the risk of GDM (odds ratio: 0.710-1.208, 95% confidence interval: 0.445-0.877 to 1.132-1.664, P > 0.05) while linkage disequilibrium was significant (D' > 0.7, R2 > 0.9). However, T-A-A-T-G haplotype was not significantly associated with GDM (χ2 = 2.461, P = 0.117). Five rare variants and 3 novel variants (rs948820149, rs1553638909, and rs1553638903) were only found in GDM. Transcription factor glucocorticoid receptor ß (GRß) bound to -807A/C (rs948820149) and knockdown of GRß suppressed PPARγ2 promoter activity. This mutation significantly down-regulated PPARγ2 expression and alleviated adipogenesis. In conclusion, a novel -807A/C in PPARγ2 promoter was identified in Chinese women with GDM and the mutation affected GRß binding and transcription of PPARγ2 for adipogenesis.

Development of noninvasive prenatal diagnosis of trisomy 21 by RT-MLPA with a new set of SNP markers.

INTRODUCTION: Placental mRNA can now be detected in maternal whole blood, raising the possibility of using maternal blood for noninvasive prenatal diagnosis (NIPD) of trisomy 21. We aimed to identify new mRNA-single nucleotide polymorphism (mRNA-SNP) markers suitable for use in reverse-transcriptase multiplex ligation-dependent probe amplification (RT-MLPA) to develop a more reliable diagnostic method for trisomy 21 in Chinese subjects. MATERIALS AND METHODS: Using sequencing, we determined the status of SNPs in genes expressed in the placenta and calculated their heterozygote frequencies to determine which loci were suitable for use in RT-MLPA. Cell-free fetal RNA was extracted from peripheral blood samples of 246 women at 12-24 weeks of pregnancy, and the SNP loci selected were analyzed by RT-MLPA, followed by capillary electrophoresis. Karyotype analyses were used to confirm the diagnosis of trisomy 21. RESULTS: As compared with karyotype analysis, the diagnostic sensitivity and specificity of RT-MLPA were excellent (95 and 100% in different gestational weeks). CONCLUSION: The RT-MLPA technique is a suitable and reliable method for the diagnosis of trisomy 21. Use of RT-MLPA with the SNP markers described here shows good specificity, high sensitivity, and high throughput potential, making this technique suitable for NIPD in clinical practice.

[Identification of risk factors related to the failure of immunization to interrupt hepatitis B virus perinatal transmission].

OBJECTIVE: To explore the factors influencing failure of an immunization to interrupt perinatal (mother-to-child) transmission of hepatitis B virus (HBV). METHODS: Between June 2006 and March 2010, a total of 1355 pregnant women testing positive for the hepatitis B surface antigen (HBsAg), at gestational weeks 20 to 42, and without use of antiviral or immunomodulatory drugs during the pregnancy were prospectively recruited to the study. The mothers were given a choice of receiving hepatitis B immunoglobulin (HBIG; three 200 IU intramuscular injections give at four-week intervals starting from gestation week 28) or not. All neonates (1360, including five sets of twins) received hepatitis B vaccine (10 mug) plus HBIG (200 IU) combined immunization within 24 h of birth, as early as possible. Peripheral venous blood samples were collected from the neonates within 24 h of birth and at 7 and 12 months of age for detection of HBV markers, including hepatitis B e antigen (HBeAg) and HBV DNA. The infants were classified according to HBV perinatal transmission status (infection group and non-infection group) and various factors (maternal-related: age, gravidity, parity; pregnancy/birth-related: threatened premature labor, complications; neonate-related: sex, birth weight, apgar score) were compared between the two groups by using non-conditional logistic regression analysis to determine their potential influence on failure of immunization to inhibit transmission. RESULTS: After 12 months of follow-up, 1.54% (21/1360) of the neonates had presented with HBV infection. Analysis of the HBV-infected neonates revealed differences in infection rates between neonates born to mothers with HBIG injection (2.22% vs. without HBIG injection: 1.11%, P less than 0.05) and caesarean section (1.35% vs. vaginal delivery: 1.73%) but neither reached statistical significance (P less than 0.05); only the practice of breastfeeding showed a significant difference for infection rate, with neonates fed artificial formula having higher infection rate (3.13%) than the breastfed neonates (0.27%, P less than 0.05). The neonate HBV infection rate was also significantly higher for neonates born to HBeAg-positive mothers (4.44% vs. HBeAg-negative mothers: 0%, P less than 0.05) and HBV DNA-positive mothers (3.13% vs. HBV DNA-negative mothers: 0%, P less than 0.05). When the mothers were stratified by serum level of HBV DNA, there was a significant difference in HBV-infected neonates born to mothers with more than or equal to 1*10(7) IU/ml(6.01% vs. 10(3)-10(6) IU/ml: 0.56% and less than 1*10(3) IU/ml: 0%, both P less than 0.05). Logistic regression analysis indicated that the independent risk factors for HBV perinatal transmission despite immunization were maternal serum HBeAg-positive status (relative risk (RR)=31.74, 95% confidence interval (CI): 3.88-259.38) and maternal HBV DNA of ≥ 107 copies/mL (RR=22.58, 95% CI: 4.75-107.40). CONCLUSION: Failure of vaccine plus HBIG to interrupt mother-to-child transmission of HBV is influenced by maternal serum HBeAg-positive status and maternal HBV DNA of ≥107 copies/mL.

[Intrauterine growth characteristics of twins and those twins discordant birthweight].

OBJECTIVE: To investigate the intrauterine growth characteristics of twins and birthweight discordant twins (discordant twins). METHODS: Total of 1010 twin pregnancies (2020 fetuses) with complete delivery records from the Department of Obstetrics and Gynecology, the First and Third Affiliated Hospital of SUN Yat-sen University between January 1, 2000 and July 31, 2010 were studied retrospectively. One handred and ninteen cases (238 fetuses) with intrapair birthweight difference ≥ 25% were determined as the discordant twins group, and the other 891 cases (1782 fetuses) with intrapair birthweight difference < 25% were identified as the concordant twins group. The singleton control group included 4042 singleton pregnancies in the same period. RESULTS: (1) Comparison of clinical data between the twins groups: the birthweight of larger-twin, smaller-twin and intrapair birthweight difference in the discordant twins group and the concordant twins group were (2090 ± 827) g, (1392 ± 592) g, (33.9 ± 9.3)%, and (2408 ± 543) g, (2191 ± 505) g, (8.9 ± 6.5)%, respectively, with significant differences (P < 0.01). The incidence of discordant twins was 11.78% (119/1010). Compared with the concordant twins group, the discordant twins group had higher proportion of monochorionic twins, and higher prevalence of pregnancy complications such as late miscarriage, abnormal umbilical insertion, twin-twin transfusion syndrome and hypertensive disorders in pregnancy (P < 0.05). (2) The characteristics of twin birthweight distribution: 1) In all the 2020 twins, 80.05% (1617/2020) fetuses had birthweight below the 50(th) percentile of the singleton control group, while 23.71% (479/2020) feeuses got birthweight below the 10(th) percentile of the singleton control group. 2) After 19(th) gestational week, the 50(th) and 90(th) percentile of all twins' birthweight were lower than those of singletons. After 38(th) gestational week, the birthweight of singletons kept increasing and reached its peak at 41(th) week, while the birthweight of twins reached its peak at 38(th) week, followed by a decline at 39 weeks, which was even lower than the 10(th) percentile of the singleton control group. 3) The distribution of birthweight of larger- and smaller-twin in the discordant twins group: 65 (54.6%, 65/119) larger-twins and one (0.8%, 1/119) smaller-twin had birthweight above the 50(th) percentile of all twins, while 5 (4.2%, 5/119) larger-twins and 97 (81.5%, 97/119) smaller-twins got birthweight below the 10(th) percentile of all twins. CONCLUSIONS: (1) The patterns of birthweight curves for each gestational week are different between twins and singletons. In order to evaluate the growth of twins, birthweight reference for twins should be employed. (2) According to the reference of twins birthweight, the most discordant twins are complicated with fetal growth restriction at least in one twin.

[Intrauterine HBV infection: risk factors and impact of HBV DNA].

OBJECTIVE: To investigate the risk factors of intrauterine hepatitis B virus (HBV) infection and the impact of HBV DNA on the infection. METHODS: The serum levels of HBsAg, HbsAb, HBeAg, HBeAb, HBcAb and HBV DNA were determined in blood samples from 230 HBsAg-positive pregnant women and their newborns by enzyme-linked immunosorbent assay (ELISA) and fluorescence quantitative PCR (FQ-PCR), respectively. The newborns acquiring HBV infection via intrauterine transmission were selected as the case group and others as the control group. The risk factors for intrauterine HBV infection were analyzed by non-conditional logistic regression model. RESULTS: Six infants were found to be HBsAg-positive, and 18 HBV DNA-positive, and 3 of them were positive for both HBsAg and HBV DNA. The rate of intrauterine HBV infection was 9.6% (22/230). The grade of HBV DNA level was identified as the only risk factor of intrauterine HBV infection by non-conditional logistic regression model, with odds ratio (OR) of 1.57 (95% confidence interval 1.12-2.21). Of the 119 pregnant women positive for HBV DNA, 18 were diagnosed as having intrauterine HBV infection, and the likeliness of the infection significantly increased for a maternal serum HBV DNA level > or =10(7) copies/ml (chi(2)=7.92, P<0.05). CONCLUSION: The grade of serum HBV DNA level is the predominant risk factor for intrauterine HBV infection in pregnant women, and for those with serum HBV DNA lever > or =10(7) copies/ml, the chance for intrauterine HBV infection can be significantly increased.

[Relations of pre-pregnant weight and weight gain during pregnancy with pregnancy-induced hypertension and birth weight].

OBJECTIVE: To determine the influence of pre-pregnant body mass index (BMI) and weight gain during pregnancy on the occurrence of pregnancy-induced hypertension (PIH) and birth weight. METHODS: Pre-pregnant BMI and pregnancy weight gain of 769 mothers giving full-term birth to a single baby for the first time were measured and the pregnancy outcomes were followed up. RESULTS: (1) The incidence of PIH and fetal macrosomia was significantly higher in the overweight group than in the normal weight and underweight groups (P<0.01 and P<0.05, respectively), but differed little between the latter two groups (P>0.05). Underweight mothers were more likely to give birth to babies with low birth weight than the normal and overweight mothers (P<0.01), but the likelihood was similar between the latter two groups (P>0.05). (2) Irrespective of the pre-pregnant BMI, PIH and fetal macrosomia occurred at higher rates with the mothers with pregnancy weight gain no less than 18 kg (P<0.01), whereas low birth weight was significantly more likely with mothers with pregnancy weight gain less than 9 kg (P<0.01). (3) A weight gain during pregnancy over 18 kg gave rise to higher risk of PIH in normal and underweight mothers, but in overweight group, PIH occurred at a significantly higher rates when a weight gain more than 9 kg was recorded (P<0.05). The incidence of fetal macrosomia was significantly higher when the maternal weight gain exceeded 18 kg in the normal weight group (P<0.01), and low birth weight occurred more frequently in relation to a maternal weight gain less than 9 kg in the normal and underweight groups (P<0.01). CONCLUSION: Pre-pregnant BMI and weight gain during pregnancy can be important factors influencing the occurrence of PIH and the neonates' birth weight.

Effect of hepatitis B immunoglobulin on interruption of HBV intrauterine infection.

AIM: To evaluate the efficacy of hepatitis B immunoglobulin (HBIG) in interrupting hepatitis B virus (HBV) intrauterine infection during late pregnancy. METHODS: We allocated 112 HBsAg positive pregnant women into 2 groups randomly. Fifty seven cases in the HBIG group received 200 IU (unit) HBIG intramuscularly every 4 wk from the 28 wk of gestation to the time of delivery, while 55 cases in the control group received no special treatment. HBsAg, HBeAg, HBcAb, HBeAb, HBsAb and HBV DNA levels were tested in the peripheral blood specimens from all of the mothers at 28 wk of gestation, just before delivery, and in blood from their newborns within 24 h before administration of immune prophylaxis. RESULTS: The intrauterine infection rate in HBIG group and control group were 10.5% and 27.3%, respectively, with significant difference (P<0.05). It showed ascendant trend as HBV DNA levels in the peripheral blood increased before delivery. CONCLUSION: HBIG is potent to cut down HBV intrauterine infection rate significantly when administered to pregnant women regularly during late pregnancy. The possibility of HBV intrauterine infection increases if maternal blood HBV DNA> or =10(8) copies/mL.

Interruption of HBV intrauterine transmission: a clinical study.

AIM: To investigate the effect of hepatitis B virus (HBV) specific immunoglobin (HBIG) and lamivudine on HBV intrauterine transmission in HBsAg positive pregnant women. METHODS: Each subject in the HBIG group (56 cases) was given 200 IU HBIG intramuscularly (im.) every 4 weeks from 28-week (wk) of gestation, while each subject in the lamivudine group (43 cases) received 100 mg lamivudine orally (po.) every day from 28-wk of gestation until the 30(th) day after labor. Subjects in the control group (52 cases) received no specific treatment. Blood specimens were tested for HBsAg, HBeAg, and HBV-DNA in all maternities at 28-wk of gestation, before delivery, and in their newborns 24 hours before the administration of immune prophylaxis. RESULTS: Reductions of HBV DNA in both treatments were significant (P<0.05). The rate of neonatal intrauterine HBV infection was significantly lower in HBIG group (16.1 %) and lamivudine group (16.3 %) compared with control group (32.7 %) (P<0.05), but there was no significant difference between HBIG group and lamivudine group (P>0.05). No side effects were found in all the pregnant women or their newborns. CONCLUSION: The risk of HBV intrauterine infection can be effectively reduced by administration of HBIG or Lamivudine in the 3(rd) trimester of HBsAg positive pregnant women.