The association of vitamin D status and supplementation during pregnancy with gestational diabetes mellitus: a Chinese prospective birth cohort study.

BACKGROUND: Previous studies have shown conflicting findings regarding the relation of vitamin D status and supplementation during pregnancy with gestational diabetes mellitus (GDM). Most of these studies hypothesized that 25-hydroxyvitamin D [25(OH)D] concentrations were associated with GDM risk and glucose metabolism based on linear association models. OBJECTIVES: We aimed to estimate the associations of 25(OH)D concentrations and vitamin D supplementation with GDM risk and glucose metabolism and determine the threshold concentrations of 25(OH)D that could significantly affect glucose metabolism and GDM risk. METHODS: In a prospective birth cohort study, we collected information about sociodemographic characteristics, health status, and lifestyle from 4984 pregnant women. Vitamin D supplementation and 25(OH)D concentrations were assessed in the second trimester. Data from the 75-g oral-glucose-tolerance test were obtained at 24-28 weeks of gestation. RESULTS: A total of 922 (18.5%) women were diagnosed with GDM. Compared with women with 25(OH)D concentrations <25 nmol/L, the GDM risk was significantly lower in women with 25(OH)D concentrations ranging from 50 to 75 nmol/L (RR: 0.74; 95% CI: 0.58, 0.95) and >75 nmol/L (RR: 0.40; 95% CI: 0.22, 0.70). The curve-fitting models suggested a significant large reduction in GDM risk, fasting plasma glucose, and area under the curve of glucose with increasing 25(OH)D concentrations only for concentrations >50 nmol/L. Consistently, GDM risk was significantly reduced only in women who took 400-600 IU vitamin D/d (RR: 0.83; 95% CI: 0.70, 0.97) with a mean 25(OH)D concentration of 50 nmol/L but not in women taking vitamin D sometimes with a mean 25(OH)D concentration of 40 nmol/L. CONCLUSIONS: GDM risk was significantly reduced only in pregnant women with 25(OH)D concentrations >50 nmol/L. Pregnant women taking 400-600 IU vitamin D/d with mean 25(OH)D concentrations of 50 nmol/L had a lower risk of GDM.

[Chloroquine induces apoptosis of human hepatocellular carcinoma cells in vitro by miR-26b-mediated regulation of Mcl-1].

OBJECTIVE: To investigate the effect of chloroquine in inducing apoptosis of human hepatocellular carcinoma cells and explore the possible mechanism. METHODS: MTT assay and flow cytometry were used to evaluate chloroquine-induced growth inhibition and apoptosis in human hepatocellular carcinoma HepG2 cells, respectively. The ATP levels in chloroquine-treated cells were detected using an ATP assay kit. PCR and Western blotting were used to detect the expression levels of miR-26b and Mcl-1 in the cells, respectively. RESULTS: Chloroquine inhibited the proliferation of HepG2 cells in a time- and concentration-dependent manner. Treatments with 80 µmol/L chloroquine for 24, 48, and 72 h induced survival rates of (71.59∓0.2)%, (45.40∓0.5)%, and (26.34∓1.4)% in the cells. Treatments with chloroquine at 40, 80, and 160 µmol/L for 5 h resulted in obviously lowered intracellular ATP levels in the cells to 87.80%, 71.29%, and 38.02% of the control level, respectively. At 80 µmol/L, chloroquine significantly increased the expression of miR-26b and down-regulated the expression of Mcl-1 in HepG2 cells, and the application of the miR-26b inhibitor increased the cellular expression of Mcl-1. CONCLUSION: s Chloroquine can inhibit the cell proliferation, reduce ATP level and induce apoptosis in HepG2 cells possibly through miR-26b-mediated regulation of Mcl-1.

Maternal depression attenuates newborn vitamin D concentrations in winter-spring: a prospective population-based study.

We aimed to investigate whether the newborns of mothers with maternal depression (MD) had lower vitamin D levels than newborns of non-MD (NMD) mothers and identify the potential mechanism underlying this association. Maternal depressive symptoms in late pregnancy and concentrations of cord blood 25 hydroxyvitamin D (25(OH)D) were measured in 1491 mother-infant pairs. Data on maternal sociodemographic characteristics, health status, lifestyle and birth outcomes were prospectively collected. For infants born in winter-spring, the infants of MD mothers had significantly reduced concentrations of 25(OH) D (adjusted ß = -3.51 nmol/L; 95% CI: -6.19, -0.84; P = 0.010) and lower birth weight (3267 ± 470 g vs 3348 ± 598 g, F = 4.64, P = 0.031), compared with the infants of NMD mothers. A significant, inverse linear relationship was noted between maternal depression scores and the concentration of 25(OH)D for infants born in winter-spring (adjusted ß = -0.158; 95% CI: -0.259, -0.057). The significant, inverse linear relationship between maternal depression scores and fetomaternal ratios of 25(OH) D was also observed among the infants born in winter-spring (adjusted ß = -0.005; 95% CI: -0.008, -0.003). MD appears to significantly attenuate the vitamin D concentrations and birth weight of infants born in winter-spring. A decreased fetomaternal ratio of 25(OH)D might be involved in this biological pathway.

Microvesicles derived from hypoxia/reoxygenation-treated human umbilical vein endothelial cells impair relaxation of rat thoracic aortic rings.

OBJECTIVE: To investigate the effects of microvesicles (MVs) derived from hypoxia/reoxygenation (H/R)-treated human umbilical vein endothelial cells (HUVECs) on endothelium-dependent relaxation of rat thoracic aortic rings. METHODS: H/R injury model was established to induce HUVECs to release H/R-EMVs. H/R-EMVs from HUVECs were isolated by ultracentrifugation from the conditioned culture medium. H/R-EMVs were characterized using 1 µm latex beads and anti-PE-CD144 by flow cytometry. Thoracic aortic rings of rats were incubated with 2.5, 5, 10, 20 µg/ml H/R-EMVs derived from H/R-treated HUVECs for 4 hours, and their endothelium-dependent relaxation in response to acetylcholine (ACh) or endothelium-independent relaxation in response to sodium nitroprusside (SNP) was recorded in vitro. The nitric oxide (NO) production of ACh-treated thoracic aortic rings of rats was measured using Griess reagent. The expression of endothelial NO synthase (eNOS) and phosphorylated eNOS (p-eNOS, Ser-1177) in the thoracic aortic rings of rats was detected by Western blotting. Furthermore, the levels of SOD and MDA in H/R-EMVs-treated thoracic aortic rings of rats were measured using SOD and MDA kit. RESULTS: H/R-EMVs were induced by H/R-treated HUVECs and isolated by ultracentrifugation. The membrane vesicles (< 1 µm) induced by H/R were CD144 positive. ACh-induced relaxation and NO production of rat thoracic aortic rings were impaired by H/R-EMVs treatment in a concentration-dependent manner (P < 0.05, P < 0.01). The expression of total eNOS (t-eNOS) was not affected by H/R-EMVs. However, the expression of p-eNOS decreased after treated with H/R-EMVs. The activity of SOD decreased and the level of MDA increased in H/R-EMVs treated rat thoracic aortic rings (P < 0.01). CONCLUSION: ACh induced endothelium-dependent relaxation of thoracic aortic rings of rats was impaired by H/R-EMVs in a concentration-dependent manner. The mechanisms included a decrease in NO production, p-eNOS expression and an increase in oxidative stress.

Effects of endothelial microvesicles induced by A23187 on H9c2 cardiomyocytes.

OBJECTIVE: To investigate the effects of endothelial microvesicles (EMVs) induced by calcium ionophore A23187 on H9c2 cardiomyocytes. METHODS: Human umbilical vein endothelial cells (HUVECs) were treated with 10 micromol/L A23187 for 30 min. EMVs from HUVECs were isolated by ultracentrifugation from the conditioned culture medium. EMVs were characterized using 1 and 2 microm latex beads and anti-PE-CD144 antibody by flow cytometry. For functional research, EMVs at different concentrations were cocultured with H9c2 cardiomyocytes for 6 h. Cell viability of H9c2 cells and the activity of LDH leaked from H9c2 cells were tested by colorimetry. Moreover, apoptosis of H9c2 cells was observed through Hoechst 33258 staining and tested by FITC-Annexin V/PI double staining. RESULTS: EMVs were induced by A23187 on HUVECs, and isolated by ultracentrifugation. We identified the membrane vesicles (< 1 microm) induced by A23187 were CD144 positive. In addition, the EMVs could significantly reduce the viability of H9c2 cells, and increase LDH leakage from H9c2 cells in a dose dependent manner (P < 0.05). Condensed nuclei could be observed with the increasing concentrations of EMVs through Hoechst 33258 staining. Furthermore, increased apoptosis rates of H9c2 cells could be assessed through FITC-Annexin V/PI double staining by flow cytometry. CONCLUSION: Microvesicles could be released from HUVECs after induced by A23187 through calcium influx, and these EMVs exerted a pro-apoptotic effect on H9c2 cells by induction of apoptosis.