Neonatal exposure of bisphenol A led to increased lipolysis of visceral adipose tissue in adult rats with DNA hypomethylation of Atgl being one of the possible underlying mechanisms.

Accumulating evidence suggests the role of developmental exposure of bisphenol A (BPA) in metabolic disorders. However, the underlying mechanism remains unclear. Using a rat model, we investigated the neonatal exposure of BPA on lipid metabolism in adult and the underlying mechanisms. From postnatal day1(PND1) to PND10, male rats were exposed to BPA via daily subcutaneous injection with 10 µg/100 µL BPA (1.24-0.5 mg/kg body weight/day, a dose below the US-EPA LOAEL). After fasting for 8 h, adult rats aged 80 days showed elevated levels of serum free fatty acid (FFA), glycerol and glucose, and increased levels of FFA and glycerol in visceral adipose tissue. The expression levels of key enzymes of lipolysis, adipose triglyceride lipase (Atgl) and hormone-sensitive lipase (Hsl), were increased in visceral adipose tissue from BPA-exposed rats after fasting. On the other hand, transcription levels of lipogenic genes remained unchanged. Differentiation of visceral adipocyte in rats takes place neonatally. In our study, neonatal BPA exposure induced DNA hypomethylation of Atgl in visceral adipose tissue. In 3T3-L1 cell, administration of 10-7 mol/L BPA throughout the differentiation stage led to DNA hypomethylation and increased expression of Atgl. Our results suggest that neonatal exposure of BPA led to increased lipolysis of visceral adipose tissue in young adults, which will predispose individuals to multiple metabolic disorders. The DNA hypomethylation of Atgl might be one of the mechanisms underneath the long-lasting effect of neonatal BPA exposure.

[Impact of GOLPH3 expression in cumulus granulosa cells on outcomes of intracytoplasmic sperm injection].

OBJECTIVE: To evaluate the impact of GOLPH3 expression in cumulus granulosa cells on the outcomes of intracytoplasmic sperm injection (ICSI). METHODS: A total of 119 women receiving ICSI due to male infertility at our center between April, 2012 and June, 2014 were enrolled in the study. Cumulus granulosa cells were collected from the women for detection of GOLPH3 expressions using immunocytochemistry, Western blotting, and real-time PCR. GOLPH3 expression rate was compared between women with and without clinical pregnancy following ICSI, and the associations of GOLPH3 expression with the laboratory indicators of ICSI outcomes were assessed. RESULTS: Immunocytochemistry showed that GOLPH3 expression was located mainly in in the plasma of the cumulus granulosa cells. The rate and intensity of GOLPH3 expression in the cumulus granulosa cells differed significantly between women with and without clinical pregnancy following ICSI (P<0.05). GOLPH3 expression was found to positively correlate with the numbers of punctured follicles, grade III oocyte cumulus complex, ICSI oocytes, fertilized oocytes, cleavage, high quality embryos, blastocysts, high quality blastocysts, and frozen embryos (all P<0.01). The results of RTPCR and Western blotting revealed significant differences in GOLPH3 expressions at both the mRNA and protein levels in the cumulus granulosa cells between the pregnant and non-pregnant groups after ICSI (t=14.560, P=0.000). Western blot analysis revealed significant difference of GOLPH3 protein expression in cumulus granulosa cells between women with and without clinical pregnancy following ICSI. CONCLUSION: GOLPH3 expression in the cumulus granulosa cells plays an important role in the development of oocytes and promotion of conception to affect the outcomes of ICSI.

Testosterone enhances early cardiac remodeling after myocardial infarction, causing rupture and degrading cardiac function.

Cardiac rupture can be fatal after myocardial infarction (MI). Experiments in animals revealed gender differences in rupture rate; however, patient data are controversial. We found a significantly higher rupture rate in testosterone-treated female mice within 1 wk after MI, whereas castration in males significantly reduced rupture. We hypothesized that testosterone may adversely affect remodeling after MI, exaggerating the inflammatory response and increasing cardiac rupture, whereas estrogen may be cardioprotective, attenuating early remodeling and reducing rupture rate. We studied the effect of gender and hormone manipulation on morphological and histological changes during early remodeling after MI in 4-wk-old male and female C57BL/6J mice and how these events could affect cardiac function. Females were randomly divided into 1) sham ovariectomy + placebo (s-ovx + P), 2) s-ovx + testosterone (T), 3) ovx + P, and 4) ovx + T; males were divided into 1) sham castration + P (s-cas + P), 2) s-cas + 17beta-estradiol (E), 3) cas + P, and 4) cas + E. At 6 wk after gonadectomy and hormone manipulation, MI was induced. Mice were randomly killed 1, 2, 4, 7, and 14 days after MI. The left ventricle was weighed and sectioned for evaluation of MI size, infarct expansion index (IEI), and neutrophil infiltration. Transthoracic echocardiography was performed in conscious mice in the 14-day group before organ harvest. Cardiac rupture rate and IEI were significantly higher in testosterone-treated females and noncastrated males than in controls; these effects were accompanied by enhanced neutrophil infiltration and pronounced deterioration of cardiac function and left ventricular dilatation. Ovariectomy in females and estrogen supplementation in males did not confer significant protection from cardiac rupture, IEI, or neutrophil infiltration. We concluded that, in mice, high testosterone levels enhance acute myocardial inflammation, adversely affecting myocardial healing and early remodeling, as indicated by increased cardiac rupture, and possibly causing deterioration of cardiac function after MI, and, conversely, estrogen seems to have no significant protective effect in the acute phase after MI.

Estrogen and testosterone have opposing effects on chronic cardiac remodeling and function in mice with myocardial infarction.

Premenopausal women are much less prone to develop cardiovascular disease than men of similar age, but this advantage no longer applies after menopause. We previously found that male mice have a significantly higher rate of cardiac rupture than females during the acute phase of myocardial infarction (MI); however, the effects of sexual hormones on chronic remodeling are unknown. We hypothesized that estrogen (E) may protect the heart from chronic remodeling and deterioration of function post-MI, whereas testosterone (T) may have adverse effects. Mice (4 wk old) of both genders were divided into four groups: female groups consisted of 1) sham ovariectomy (S-Ovx) + placebo (P) (S-Ovx + P), 2) S-Ovx + T, 3) Ovx + P, and 4) Ovx + T; and male groups consisted of 1) sham castration (S-Cas)+ P (S-Cas + P), 2) S-Cas + 17beta-estradiol (E), 3) Cas + P, and 4) Cas + E. MI was induced 6 wk later. Echocardiography was performed to assess cardiac function and left ventricular dimensions (LVD). Myocyte cross-sectional area (MCSA) was measured at the end of the study. In females, both testosterone and ovariectomy decreased ejection fraction (EF) and increased LVD, and when combined they aggravated cardiac function and remodeling further. Testosterone significantly increased MCSA. In males, castration or estrogen increased EF and reduced LVD, whereas castration significantly reduced MCSA. Our data suggest that estrogen prevents deterioration of cardiac function and remodeling after MI, but testosterone worsens cardiac dysfunction and remodeling and has a pronounced effect when estrogen levels are reduced.