[The effect of Connexin43 downregulation on biological functions of HUVEC].

Connexin43 has been shown to play a pivotal role in wound healing process. Wound repair is enhanced by acute downregulation of connexin43, by increasing proliferation and migration of keratinocyte and fibroblast. Angiogenesis is also a central feature of wound repair, but little is known about the effects of connexin43 modulation on functions of endothelial cells. We used connexin43 specific small interference RNA (siRNA) to reduce the expression of connexin43 in human umbilical vein endothelial cell (HUVEC), and investigated the effects of connexin43 downregulation on intercellular communication, viability, proliferation, migration and angiogenic activity of HUVEC. Treatment of siRNA markedly reduced the expression of connexin43 by -80% in HUVEC (P < 0.05), and decreased the intercellular communication by -65% (P < 0.05). The viability, proliferation, migration and angiogenic activity of HUVEC decreased significantly (P < 0.05), compared with that of the normal cells. The results suggest that temporally downregulation of connexin43 expression at early stage of wound to inhibit the abnormal angiogenesis characterized with leaky and inflamed blood vessels, maybe a prerequisite for coordinated normal healing process.

Associations of prenatal exposure to bisphenols with BMI growth trajectories in offspring within the first two years: evidence from a birth cohort study in China.

BACKGROUND: Prenatal bisphenol exposure has been reported to be associated with lower birth weight and obesity-related indicators in early childhood. These findings warrant an investigation of the relationship between prenatal bisphenol exposure and the dynamic growth of offspring. This study aimed to evaluate the relationship of maternal bisphenol concentration in urine with the body mass index (BMI) growth trajectory of children aged up to two years and to identify the critical exposure periods. METHODS: A total of 826 mother-offspring pairs were recruited from Wuhan Children's Hospital between November 2013 and March 2015. Maternal urine samples collected during the first, second, and third trimesters were analyzed for bisphenol A (BPA), bisphenol S, and bisphenol F (BPF) concentrations. Measurements of length and weight were taken at 0, 1, 3, 6, 8, 12, 18, and 24 months. Children's BMI was standardized using the World Health Organization reference, and group-based trajectory modeling was used to identify BMI growth trajectories. The associations between prenatal bisphenol exposure and BMI growth trajectory patterns were assessed using multinomial logistic regression models. RESULTS: The BMI growth trajectories of the 826 children were categorized into four patterns: low-stable (n = 134, 16.2%), low-increasing (n = 142, 17.2%), moderate-stable (n = 350, 42.4%), and moderate-increasing (n = 200, 24.2%). After adjusting for potential confounders, we observed that prenatal exposure to BPA during the second trimester [odds ratio (OR) = 2.20, 95% confidence interval (CI) = 1.09-4.43] and BPF during the third trimester (OR = 3.28, 95% CI = 1.55-6.95) at the highest quartile concentration were associated with an increased likelihood of the low-increasing BMI trajectory. Furthermore, in the subgroup analysis by infant sex, the positive association between the highest quartile of prenatal average urinary BPF concentration during the whole pregnancy and the low-increasing BMI trajectory was found only in girls (OR = 2.82, 95% CI = 1.04-7.68). CONCLUSION: Our study findings suggest that prenatal exposure to BPA and BPF (a commonly used substitute for BPA) is associated with BMI growth trajectories in offspring during the first two years, increasing the likelihood of the low-increasing pattern. Video Abstract (MP4 120033 kb).

GDF-15 gene expression alterations in human lymphoblastoid cells and peripheral blood lymphocytes following exposure to ionizing radiation.

The identification of rapid, sensitive and high­throughput biomarkers is imperative in order to identify individuals harmed by radiation accidents, and accurately evaluate the absorbed doses of radiation. DNA microarrays have previously been used to evaluate the alterations in growth/differentiation factor 15 (GDF15) gene expression in AHH­1 human lymphoblastoid cells, following exposure to γ­rays. The present study aimed to characterize the relationship between the dose of ionizing radiation and the produced effects in GDF­15 gene expression in AHH­1 cells and human peripheral blood lymphocytes (HPBLs). GDF­15 mRNA and protein expression levels following exposure to γ­rays and neutron radiation were assessed by reverse transcription­quantitative polymerase chain reaction and western blot analysis in AHH­1 cells. In addition, alterations in GDF­15 gene expression in HPBLs following ex vivo irradiation were evaluated. The present results demonstrated that GDF­15 mRNA and protein expression levels in AHH­1 cells were significantly upregulated following exposure to γ­ray doses ranging between 1 and 10 Gy, regardless of the dose rate. A total of 48 h following exposure to neutron radiation, a dose­response relationship was identified in AHH­1 cells at γ­ray doses between 0.4 and 1.6 Gy. GDF­15 mRNA levels in HPBLs were significantly upregulated following exposure to γ­ray doses between 1 and 8 Gy, within 4­48 h following irradiation. These results suggested that significant time­ and dose­dependent alterations in GDF­15 mRNA and protein expression occur in AHH­1 cells and HPBLs in the early phases following exposure to ionizing radiation. In conclusion, alterations in GDF­15 gene expression may have potential as a biomarker to evaluate radiation exposure.

Dose-effect of ionizing radiation-induced PIG3 gene expression alteration in human lymphoblastoid AHH-1 cells and human peripheral blood lymphocytes.

PURPOSE: To identify new ionizing radiation (IR)-sensitive genes and observe the dose-effect of gene expression alteration (GEA) induced by IR. MATERIALS AND METHODS: Microarray was used to screen the differentially expressed genes in human lymphoblastoid cells (AHH-1) using three doses of (60)Co γ-rays (0.5-8 Gy at 1 Gy/min). Given that p53-inducible gene 3 (PIG3) was consistently upregulated, the GEA of PIG3 in AHH-1 cells and human peripheral blood lymphocytes (HPBL) induced by γ-rays (1 Gy/min) was measured at messenger RNA (mRNA) and protein levels. The GEA of PIG3 in AHH-1 cells exposed to neutron radiation (californium-252, 0.073 Gy/min) was also quantified. RESULTS: PIG3 was one of the seven differentially expressed genes found in the microarray analysis. The PIG3 mRNA and protein levels in AHH-1 cells were significantly increased from 1-10 Gy of γ-rays 8-72 h or 8-168 h after exposure, respectively. The enhancement was also observed in AHH-1 cells from 0.4-1.6 Gy of neutrons 48 h post-irradiation. The PIG3 mRNA levels (mRNA copy numbers) in HPBL were significantly increased from 1-8 Gy of γ-rays within 4-24 h post-irradiation, but the highest increase in signal-to-noise responsiveness is approximately two-fold, which was less than that of AHH-1 (approximately 20-fold). CONCLUSIONS: IR can upregulate the PIG3 gene expression in AHH-1 and HPBL in the early phase after exposure; however, the IR induced expression levels of PIG3 are greater in AHH-1 than HPBL.