Ru360 protects against vitrification-induced oocyte meiotic defects by restoring mitochondrial function.

Oocyte vitrification has been widely application in female fertility preservation. Recent studies found that vitrification of immature (germinal vesicle stage, GV) oocytes increased the risk of aneuploidy during meiotic maturation; however, the underlying mechanisms and the strategies to prevent this defect remain unexplored. In this study, we found that vitrification of GV oocytes decreased the first polarbody extrusion rate (90.51 ± 1.04% vs. 63.89 ± 1.39%, p < 0.05) and increased the aneuploid rate (2.50% vs. 20.00%, p < 0.05), accompanied with a series of defects during meiotic maturation, including aberrant spindle morphology, chromosome misalignment, incorrect Kinetochore-Microtubule attachments (KT-MTs) and weakened spindle assembly checkpoint protein complex (SAC) function. We also found that vitrification disrupted mitochondrial function by increasing mitochondrial Ca2+ levels. Importantly, inhibition of mitochondrial Ca2+ entry by 1 µM Ru360 significantly restored mitochondrial function and rescued the meiotic defects, indicating that the increase of mitochondrial Ca2+, at least, was a cause of meiotic defects in vitrified oocytes. These results shed light on the molecular mechanisms of oocyte vitrification-induced adverse effects of meiotic maturation and provided a potential strategy to improve oocyte cryopreservation protocols further.

All-Trans Retinoic Acid Inhibits Bone Marrow Mesenchymal Stem Cell Commitment to Adipocytes via Upregulating FRA1 Signaling.

Obesity, caused by an increased number and volume of adipocytes, is a global epidemic that seriously threatens human health. Bone marrow mesenchymal stem cells (BMSCs) can differentiate into adipocytes. All-trans retinoic acid (atRA, the active form of vitamin A) inhibits the adipogenic differentiation of BMSCs through its receptor RARG. The expression level of FRA1 (FOS like 1, AP-1 transcription factor subunit) in atRA-treated BMSCs increased, suggesting that atRA-mediated inhibition of BMSCs adipogenesis involves FRA1. BMSCs were transfected with adenovirus overexpressing Fra1 (ad-fra1) or silenced for Fra1 (si-fra1) and then treated with atRA. BMSCs treated with atRA and treated with ad-fra1 showed decreased mRNA and protein levels of key adipogenic genes (Pparg2, Cebpa) and adipogenesis-associated genes (Cd36, Fabp, Lpl, and Plin); atRA had a stronger inhibitory effect on adipogenesis compared with that in the ad-fra1 group. Adipogenic gene expression in Fra1-silenced BMSCs was significantly upregulated. Compared with that in the atRA group, the si-fra1 + atRA also upregulated adipogenic gene expression. However, compared with si-fra1, si-fra1 + atRA significantly inhibited adipogenic differentiation. Chromatin immunoprecipitation showed that RARG directly regulates Fra1 and FRA1 directly regulates Pparg2 and Cebpa. The results supported the conclusion that atRA inhibits BMSC adipogenesis partially through the RARG-FRA1-PPARG2 or the CEBPA axis or both. Thus, vitamin A might be used to treat obesity and its related diseases.

Vitamin A bio-modulates apoptosis via the mitochondrial pathway after hypoxic-ischemic brain damage.

Our previous studies demonstrated that vitamin A deficiency (VAD) can impair the postnatal cognitive function of rats by damaging the hippocampus. The present study examined the effects of retinoic acid (RA) on apoptosis induced by hypoxic-ischemic damage in vivo and in vitro, and investigated the possible signaling pathway involved in the neuroprotective anti-apoptotic effects of RA. Flow cytometry, immunofluorescence staining and behavioral tests were used to evaluate the neuroprotective and anti-apoptotic effects of RA. The protein and mRNA levels of RARα, PI3K, Akt, Bad, caspase-3, caspase-8, Bcl-2, Bax, and Bid were measured with western blotting and real-time PCR, respectively. We found impairments in learning and spatial memory in VAD group compared with vitamin A normal (VAN) and vitamin A supplemented (VAS) group. Additionally, we showed that hippocampal apoptosis was weaker in the VAN group than that in VAD group. Relative to the VAD group, the VAN group also had increased mRNA and protein levels of RARα and PI3K, and upregulated phosphorylated Akt/Bad levels in vivo. In vitro, excessively low or high RA signaling promoted apoptosis. Furthermore, the effects on apoptosis involved the mitochondrial membrane potential (MMP). These data support the idea that sustained VAD following hypoxic-ischemic brain damage (HIBD) inhibits RARα, which downregulates the PI3K/Akt/Bad and Bcl-2/Bax pathways and upregulates the caspase-8/Bid pathway to influence the MMP, ultimately producing deficits in learning and spatial memory in adolescence. This suggests that clinical interventions for HIBD should include suitable doses of VA.

The paracrine effect of cobalt chloride on BMSCs during cognitive function rescue in the HIBD rat.

Hypoxia-ischemia (HI)-induced perinatal encephalopathy frequently causes chronic neurological morbidities and acute mortality. Bone mesenchymal stem cell (BMSC) transplantation could potentially promote functional and anatomical recovery of ischemic tissue. In vitro hypoxic preconditioning is an effective strategy to improve the survival of BMSCs in ischemic tissue. In this study, cobalt chloride (CoCl2) preconditioned medium from BMSC cultures was injected into the left lateral ventricle of HI rats using a micro-osmotic pump at a flow rate 1.0µl/h for 7 days. The protein levels of HIF-1α and its target genes, vascular endothelial growth factor and erythropoietin, markedly increased after CoCl2 preconditioning in BMSCs. In 7-week-old rats that received CoCl2 preconditioned BMSC medium, results of the Morris water maze test indicated ameliorated spatial working memory function following hypoxia-ischemia damage. Neuronal loss, cellular disorganization, and shrinkage in brain tissue were also ameliorated. Extracellular field excitatory postsynaptic potentials (fEPSPs) in the brain slices of 8-week-old rats were recorded; administration of CoCl2 preconditioned BMSC culture medium induced a progressive increment of baseline and amplitude of the fEPSPs. Immunohistochemical quantification showed that GluR2 protein expression increased. In conclusion, CoCl2 activates HIF-1α signals in BMSCs. CoCl2 preconditioned BMSC culture medium likely effects neuroprotection by inducing long-term potentiation (LTP), which could be associated with GluR2 expression. The paracrine effects of hypoxia preconditioning on BMSCs could have applications in novel cell-based therapeutic strategies for hypoxic and ischemic brain injury.

Periconceptional folic acid supplementation and vitamin B12 status in a cohort of Chinese early pregnancy women with the risk of adverse pregnancy outcomes.

Maternal folate and vitamin B12 deficiency predict poor pregnancy outcome. To improve pregnancy outcomes in rural area of China, we investigate rural women's folic acid supplementation (FAS) status and the associations between maternal vitamin B status during the first trimester and subsequent adverse pregnancy outcomes. We collected the questionnaire information and drew 5 ml of blood from 309 early pregnant rural women. The birth outcomes were retrieved from medical records after delivery. Out of the total, 257 had taken FAS, including 50 before conception (group A) and 207 during the first trimester (group B). The concentration of plasma folate and the RBC folate supplementation groups were obviously higher than that of no-supplementation group (group N, p<0.01). The mean vitamin B12 levels in FAS group were significantly higher than those in groups N and B (p<0.05). Women who delivered SGA or premature infants had reduced plasma folate levels (p<0.05) compared with controls. The multiple linear regression models revealed that RBC folate levels affected the infant birth weight (p<0.01) and birth length (p<0.05). In conclusion, FAS can significantly improve plasma folate and RBC folate levels in childbearing-age women and reduce the risk of subsequent adverse pregnancy outcomes.

Marginal Vitamin A Deficiency Exacerbates Memory Deficits Following Aß1-42 Injection in Rats.

BACKGROUND: Although clinical vitamin A deficiency (VAD), which is a public health problem developing throughout the world, has been well controlled, marginal vitamin A deficiency (MVAD) is far more prevalent, especially among pregnant women and preschool children in China. Increasing evidence suggests that VAD is involved in the pathogenesis of Alzheimer's disease (AD). However, whether MVAD, beginning early in life, increases the risk of developing AD has yet to be determined. OBJECTIVE: The goal of this study was to investigate the long-term effects of MVAD on the pathogenesis of AD in rats. METHOD: An MVAD model was generated from maternal MVAD rats and maintained with an MVAD diet after weaning. The males were bilaterally injected with aggregated amyloid ß (Aß)1-42 into the CA3 area of the hippocampus, and the AD-associated cognitive and neuropathological phenotypes were examined. RESULTS: We found that MVAD feeding significantly aggravated Aß1-42-induced learning and memory deficits in the Morris water maze test. MVAD did not induce the mRNA expression of retinoic acid receptors (RARs), a disintegrin and metalloprotease 10 (ADAM10) or insulin-degrading enzyme (IDE) in Aß1-42-injected rats. Moreover, RARα and RARγ mRNA were positively correlated with ADAM10 mRNA, whereas RARß mRNA was positively correlated with IDE mRNA. CONCLUSION: Our study suggests that MVAD beginning from the embryonic period perturbs the ADassociated genes, resulting in an enhanced risk of developing AD.

[Association between development of hypertension and nutrition in school-age children in Fengdu County of Chongqing, China].

OBJECTIVE: To investigate the association between the development of hypertension and nutrition in school-age children in Fengdu County of Chongqing, China. METHODS: A total of 8 033 children from 2 public primary schools in Fengdu County of Chongqing, whose registered residence was in the subdistricts where the two schools were located, were selected as study subjects using cluster random sampling. Body height, body weight, and blood pressure were measured, and the semi-quantitative food frequency questionnaire was used for dietary survey. The association between body mass index (BMI), dietary nutrients, and the development of hypertension in children was analyzed. RESULTS: A total of 7 538 children were enrolled for analysis. The detection rates of obesity, overweight, and hypertension were 9.11%, 12.27%, and 11.83% respectively. In children with obesity and overweight, the detection rate of hypertension was 33.62% and 17.84% respectively, 4.02 and 2.13 times that in normal children. The multivariate logistic stepwise regression analysis revealed that increased intake of calcium and sodium increased the risk of hypertension (OR=1.003 and 1.002 respectively), while the increased iron intake and calcium intake per unit body weight reduced the risk of hypertension (OR=0.979 and 0.926 respectively). CONCLUSIONS: The prevalence of hypertension and obesity in school-age children in Fengdu County of Chongqing is high. BMI and dietary nutrients are closely associated with the development of hypertension in children. Active control of body weight, adjustment of dietary structure, and limitation of sodium intake should be adopted to reduce the development of hypertension in school-age children.

Serum vitamin A status is associated with obesity and the metabolic syndrome among school-age children in Chongqing, China.

The aim of our study was to examine the association of vitamin A status with obesity and the metabolic syndrome (MS) in school-age children in Chongqing, China. A cross-sectional study was conducted of 1,928 children aged 7~11 years from 5 schools in Chongqing, China. Body height, weight, waist circumference (WC) and blood pressure were measured. Blood glucose, lipids and vitamin A were determined. Overall prevalences for overweight, obesity and MS were 10.1%, 6.7% and 3.5%, respectively. There were 274 (14.2%) marginally vitamin A deficient (MVAD) children and 53 (2.8%) vitamin A deficient (VAD) children, respectively. Serum vitamin A in the obese group was significantly lower than in the overweight and normal weight groups (p<0.001). Body mass index (BMI), WC, high density lipoprotein cholesterol (HDL-C) and glucose were strongly associated with vitamin A status (p<0.05). In a separate model adjusted for age and sex, compared with normal children, participants with obesity had a significantly higher risk of having vitamin A insufficiency (<=1.05 µmol/L) (OR: 2.37; 95% CI: 1.59, 3.55) (p<0.001), and participants with MS had a 1.99-fold (95% CI: 1.14, 3.47) greater risk of having vitamin A insufficiency (p=0.016), while participants with VAD had significantly higher risk of having MS (OR: 3.82; 95% CI: 1.44, 10.2) (p=0.007). Vitamin A insufficiency among Chongqing urban school-age children was found to be a severe health problem, significantly associated with obesity, hypertriglyceridemia and MS.

Plasma antioxidant enzymes and lipoperoxidation status in children with Down syndrome.

OBJECTIVES: Oxidative stress (OS) may play a critical role in cell aging and neurologic disorders that are often seen in Down syndrome (DS) patients. The aim of this study was to determine the antioxidant enzyme level and lipoperoxidation status in blood from DS children. DESIGN AND METHODS: In a cross-sectional study, we recruited a total of 36 DS children and 40 healthy controls (HCs). All subjects were free of infection according to the C reactive protein (CRP) value and routine peripheral blood profile. The activities of total superoxide dismutases (SODs), extracellular glutathione peroxidase (GPx3),malondialdehyde (MDA) and nitric oxide synthase (NOS) concentrations in peripheral blood were measured by spectrophotometric methods. The relationship of SOD and GPx3 was analyzed in the two groups. RESULTS: The two groups were similar with respect to age, gender and peripheral blood profiles. The total SOD activity was significantly increased, while the GPx3 activity was significantly reduced in the DS group compared to the HCs (p=0.000, p=0.033 respectively). The MDA level was higher in DS children (p=0.013). There was no significant difference in NOS between DS and HCs (p=0.708). A significant negative correlation between GPx3 and SOD activity was identified in DS (r=-0.14, p=0.018) but not in the HC group. CONCLUSIONS: Abnormal redox metabolism takes place in DS individuals. Reducing GPx3 may be a compensatory mechanism of protection against intracellular OS. Moreover, monitoring of decreases in GPx3 activity may be a useful biomarker for evaluating OS in DS patients.

[Acetylated Histone Expressions of the Primary Hippocampal Neurons in Rats Reduced by siCBP Lentivirus].

This study aims to construct the recombinant lentivirus vector containing specific small interfering RNA (siRNA) targeting rat CREB binding protein(CBP)gene and to identify its function of inhibiting the expressions of acetylated histone in primarily cultured hippocampal neurons. Firstly, we constructed four kinds of recombinant lentivirus siCBP. And then we used them to infect the primarily cultured hippocampal neurons, and performed real-time PCR, western blot respectively to detect the expressions of CBP. Afterwards, the most effective lentivirus siCBP was used to infect the primarily cultured hippocampal neurons, and then the HAT activity and protein expressions of acetylated histone Ac-H3, Ac-H4 of the neurons were examined. By using PCR, endonuclease cutting and gene sequencing, we confirmed that the target genes were correctly cloned in lentivirus vector. Besides, CBP mRNA and protein expressions in neurons were found to be with varying degrees of decreases after infections of the four kinds of lentivirus siCBP. Furthermore, the representative and most effective lentivirus GR806 could effectively inhibit the HAT activity and the protein expressions of Ac-H3, Ac-H4 in neurons. It provides the experimental basis for the subsequent application of siCBP to clarify the effects and corresponding molecular mechanism of the CBP-dependent histone acetylation on learning and memory function in hippocampus.

Effect of the one­carbon unit cycle on overall DNA methylation in children with Down's syndrome.

DNA methylation is a major epigenetic mechanism regulating gene expression. In order to analyze the impact of the one­carbon unit cycle on the overall level of DNA methylation in children with Down's syndrome (DS), the levels of indicators associated with the one­carbon unit cycle, including folic acid (FA), vitamin B12 (VB12) and homocysteine (Hcy), and the overall DNA methylation level of DS and healthy controls (HCs) were determined in the present study. A total of 36 DS children and 40 age­ and gender­matched HCs were included in the present study to determine the levels of FA, VB12, Hcy and overall DNA methylation. The effect of the one­carbon unit cycle on the overall level of DNA methylation within the DS group was analyzed. The results demonstrated that the level of VB12 was decreased (P=0.008), while the Hcy level was increased (P=0.000) in DS patients compared with the HCs. FA and VB12 levels decreased with increasing age in DS patients (P<0.05). DNA hypermethylation and hypomethylation were observed in DS patients with VB12 deficiency and hyperhomocysteinemia, respectively (P=0.031, P=0.021). Abnormalities in the one­carbon unit cycle tend to worsen with increasing age in DS children. Thus, one­carbon unit cycle­associated alterations in DNA methylation may be important in the neuropathological alterations observed in DS.

Vitamin A deficiency impairs spatial learning and memory: the mechanism of abnormal CBP-dependent histone acetylation regulated by retinoic acid receptor alpha.

Vitamin A (VA) is an essential micronutrient. Numerous studies have confirmed that VA deficiency (VAD) leads to a decline in learning and memory function. Our previous studies have demonstrated that retinoic acid nuclear receptor α (RARα) in the hippocampus plays a crucial role in learning and memory, but the exact mechanism for this process is unclear. Epigenetic modifications, particularly histone acetylation, are involved in nervous system development, learning and memory function, and the pathogenesis of neurodegenerative diseases. Histone acetyltransferases (HATs), such as CREB-binding protein (CBP), E1A-binding protein p300 (p300), and p300/CBP-associated factor (PCAF), are critical for regulating memory function. The current study uses RARα and CBP as examples to study the connections between the RA signaling pathway and histone acetylation modification and to reveal the epigenetic mechanism in VAD-induced learning and memory impairment. This study examined the expression of RARα, HATs, acetylated histone H3/H4, and memory-related genes (Zif268, cFos, FosB), as well as the interaction of RARα and CBP in the hippocampus of 8-week-old rats. Additionally, the changes shown in vivo were further assessed in primary cultured neurons with the inhibition or overexpression of RARα. We found significantly lower levels of histone acetylation in the VAD rats. Furthermore, this downregulation, which impairs learning and memory, is induced by the dysregulation of CBP-dependent histone acetylation that is mediated by RARα. This work provides a solid theoretical foundation and experimental basis for the importance of ensuring sufficient nutritional VA during pregnancy and early life to prevent impairments of learning and memory in adulthood.

5-Mehtyltetrahydrofolate rescues alcohol-induced neural crest cell migration abnormalities.

BACKGROUND: Alcohol is detrimental to early development. Fetal alcohol spectrum disorders (FASD) due to maternal alcohol abuse results in a series of developmental abnormalities including cranial facial dysmorphology, ocular anomalies, congenital heart defects, microcephaly and intellectual disabilities. Previous studies have been shown that ethanol exposure causes neural crest (NC) apoptosis and perturbation of neural crest migration. However, the underlying mechanism remains elusive. In this report we investigated the fetal effect of alcohol on the process of neural crest development in the Xenopus leavis. RESULTS: Pre-gastrulation exposure of 2-4% alcohol induces apoptosis in Xenopus embryo whereas 1% alcohol specifically impairs neural crest migration without observing discernible apoptosis. Additionally, 1% alcohol treatment considerably increased the phenotype of small head (43.4% ± 4.4%, total embryo n = 234), and 1.5% and 2.0% dramatically augment the deformation to 81.2% ± 6.5% (n = 205) and 91.6% ± 3.0% (n = 235), respectively (P < 0.05). Significant accumulation of Homocysteine was caused by alcohol treatment in embryos and 5-mehtyltetrahydrofolate restores neural crest migration and alleviates homocysteine accumulation, resulting in inhibition of the alcohol-induced neurocristopathies. CONCLUSIONS: Our study demonstrates that prenatal alcohol exposure causes neural crest cell migration abnormality and 5-mehtyltetrahydrofolate could be beneficial for treating FASD.

[Effect of dietary vitamin A intake on plasma vitamin A concentration in preschool children of Banan district, Chongqing, China].

OBJECTIVE: To study the relationship between dietary vitamin A intake and plasma vitamin A concentration, and establish the theoretical basis for dietary intake predicting vitamin A nutritional status. METHODS: By using cluster sampling, 492 children aged 2-7 years in kindergartens in Banan district of Chongqing were selected. A cross-sectional nutrition and health survey was conducted, including the clinical examination, anthropometry, laboratory test and dietary survey. RESULTS: Among the children surveyed, 229 were boys, and 263 girls, the mean age was (4.54 ± 0.87) years, height (107.50 ± 7.20) cm, and weight (18.42 ± 3.41) kg, the mean value of plasma vitamin A was (1.04 ± 0.30) µmol/L. The prevalence of marginal vitamin A deficiency (MVAD) was 43.5%. No cases of severe clinical vitamin A deficiency were found (plasma vitamin A ≤ 0.35 µmol/L). Clinical examination found no conjunctiva, corneaor skin abnormalities, and no Bitot's spots. Prevalence of the last two weeks colds were 27.4% (135/492), no diarrhea and other gastrointestinal or digestive diseases were found. The proportion of insufficient dietary vitamin A intake (<600 µg RE/d) was as high as 50.0%. By using correlation analysis, plasma retinol concentrations were related to dietary vitamin A intake (r=0.162, P<0.001), and to dietary energy intake (r=0.107, P=0.017). After adjustment for the effects of other non-dietary factors on vitamin A deficiency, the multivariate logistic regression showed that vitamin A-rich foods of liver intake=0 g/d (OR=1.95, 95% CI: 1.05-3.61, P=0.034), vitamin A-rich fruits intake=0 g/d (OR=1.55, 95% CI: 1.03-2.33, P=0.034), vitamin A-rich vegetables intake<200 g/d (OR=3.47, 95% CI: 1.37-8.75, P=0.009) were important risk factors of vitamin A deficiency. But we had not found the correlation between the intake of meat, eggs and milk and vitamin A deficiency. CONCLUSION: Dietary factors may be the major risk factor of vitamin A deficiency in the three kindergartens. The dietary vitamin A intakes are significantly related to plasma retinol concentrations, and the vitamin A-rich foods intakes can predict the body's vitamin A nutritional status.

Spatiotemporal expression of HDAC2 during the postnatal development of the rat hippocampus.

BACKGROUND: Histone acetylation, which is a chromatin modification of histone tails, can dynamically regulate the expression of various genes in normal development. HDAC2 is a negative regulatory factor of acetylation and closely related to learning and memory. NSE is a nerve marker and vital for maintaining physiological functions in nervous system. Currently, few studies associated with the expression pattern of HDAC2 in postnatal rat hippocampus have been reported. This study aimed to explore the temporal and spatial expression pattern of HDAC2, helping to reveal the expression characteristics of HDAC2 during postnatal neuronal maturation. MATERIALS AND METHODS: With NSE as a biomarker of neuronal maturation at postnatal days 1, 3, 7 and weeks 2, 4, and 8 (P1D, P3D, P7D, P2W, P4W, P8W), the expression patterns of HDAC2 in rat hippocampus were examined using real-time PCR and western blotting. Additionally, the subcellular distribution of HDAC2 was analysed by immunofluorescence. RESULTS: We found that HDAC2 was highly expressed in the neonatal period and decreased gradually. HDAC2 expression was widely distributed in neurons of hippocampal CA1, CA3 and DG regions and gradually shifted from the nucleus to the cytoplasm during postnatal development. Altogether, the expression of HDAC2 decreased gradually with different subcellular localizations throughout development. CONCLUSIONS: The observed results indicate that the expression levels of HDAC2 become lower and with different subcellular localizations in neurons during hippocampal neuronal maturation, suggesting the specific expression characteristics of HDAC2 might play an important role during postnatal learning-memory function and development.

The effect of hypertension and diabetes management in Southwest China: a before- and after-intervention study.

BACKGROUND: Non-communicable diseases are leading causes of disease burden in middle income countries. Little evidence exists to determine if the primary healthcare system can effectively manage non-communicable diseases. The purpose of this study was to examine the effectiveness of hypertension and diabetes management by the primary healthcare system. METHODS: We used individual level data from the 2009 National Basic Public Health Services System to assess the effectiveness of hypertension and diabetes interventions on fasting plasma glucose, and blood pressure. We analyzed the associations between fasting plasma glucose, systolic or diastolic blood pressure and risk factors. The estimated average intervention effect on data balanced with confounding variables was assessed. RESULTS: 9543 individuals who had data for fasting plasma glucose, systolic blood pressure and diastolic blood pressure were included in this analysis. This study included 6681 patients with hypertension and 2222 with diabetes. The intervention lowered mean fasting plasma glucose by 0.5 mmol/L (0.4-0.6), lowered mean systolic blood pressure by 3.5 mm Hg (3.2-3.7), and lowered diastolic blood pressure by 2.9 mm Hg (2.7-3.2). Individuals who received medicinal treatment had 1.3 mmHg (0.8 to 1.8, P<0.01) lower diastolic blood pressure and 0.6 mmol/L (0.5-0.8, P<0.01) lower fasting plasma glucose than those who did not receive medicine. Generalized linear model indicated that medicinal treatment and baseline systolic blood pressure were significant positive predictors of change in systolic blood pressure. Age, living in urban areas and diabetic complications were significant negative predictors of change for systolic blood pressure. CONCLUSION: The National Basic Public Health Services System in China using trained community healthcare workers and well-established guidelines can be effectively implement non-communicable disease prevention and management care paradigms.

Preconditioning and post-treatment with cobalt chloride in rat model of perinatal hypoxic-ischemic encephalopathy.

BACKGROUND: Hypoxia-ischemia (HI)-induced perinatal encephalopathy is a major cause of acute mortality and chronic neurologic morbidities such as cerebral palsy, mental retardation, and epilepsy. As the essential transcription factor for the activation of hypoxia-inducible genes, hypoxia-inducible factor 1 alpha (HIF-1α) plays an important role in the pathophysiological response to the stress of HI brain damage. Whether HIF-1α activation promotes neuroprotection in HI tissues is controversial. METHODS: The left common carotid artery of rats aged 7days was ligated under anesthesia. The pups were then exposed to hypoxia in a normobaric chamber filled with 8% oxygen and 92% nitrogen for 2.5h. In the sham control group, the left common carotid artery was exposed but was not ligated or exposed to hypoxia. To assess the time window for effective treatment, the HIF-1α inducer cobalt chloride (CoCl2) was injected subcutaneously 1day before surgery, immediately or 1day after surgery. The brain tissues were harvested from the pups of each groups at 1, 2 and 7days after insult for HIF-1α protein ant its target genes expression and for investigating the injury. Morris water maze tests were performed at postnatal 7weeks. RESULTS: HIF-1α protein levels and its target genes vascular endothelial growth factor, heme oxygenase-1, and insulin-like growth factor 1 were markedly increased after intraperitoneal injection of CoCl2 (60mg/kg). The target gene inducible nitric oxide synthase exhibited a biphasic time course. HI caused apoptosis and reduced capillary density, which were ameliorated by CoCl2. Both preconditioning with CoCl2 24h before HI and administration of CoCl2 24h after HI improved long-term reference memory compared with that in vehicle-injected littermate controls. Administration of CoCl2 immediately after HI did not improve spatial working memory. CONCLUSIONS: CoCl2 activates HIF-1α and protects against brain damage in vivo. The time of administration could be used to manipulate the activity of HIF-1α pathways and promote recovery.

AP2α transcriptional activity is essential for retinoid-induced neuronal differentiation of mesenchymal stem cells.

Pre-activation of the retinoid signaling pathway by all-trans retinoic acid facilitates neuronal differentiation of mesenchymal stem cells. Using protein/DNA based screening assays, we identified activator protein 2α as an important downstream target of all-trans retinoic acid. Although all-trans retinoic acid treatment significantly increased activator protein 2α transcriptional activity, it did not affect its expression. Inhibition of activator protein 2α with dominant-negative mutants reduced ATRA-induced differentiation of mesenchymal stem cells into neurons and reversed its associated functional recovery of memory impairment in the cell-based treatment of a hypoxic-ischemic brain damage rat model. Dominant-negative mutants of activator protein 2α inhibited the expression of neuronal markers which were induced by retinoic acid receptor ß activation. All-trans retinoic acid treatment increased phosphorylation of activator protein 2α and resulted in its nuclear translocation. This was blocked by siRNA-mediated knockdown of retinoic acid receptor ß. Furthermore, we found that retinoic acid receptor ß directly interacted with activator protein 2α. In summary, the regulation of all-trans retinoic acid on activator protein 2α transcriptional activity was mediated by activation of retinoic acid receptor ß and subsequent phosphorylation and nuclear translocation of activator protein 2α. Our results strongly suggest that activator protein 2α transcriptional activity is essential for all-trans retinoic acid-induced neuronal differentiation of mesenchymal stem cells.

Effects of egg and vitamin A supplementation on hemoglobin, retinol status and physical growth levels of primary and middle school students in Chongqing, China.

Lack of protein and vitamin A influences the growth of student in impoverished mountain areas. The aim of the study was to assess the effects of egg and vitamin A supplementation on hemoglobin, serum retinol and anthropometric indices of 10-18 years old students of a low socioeconomic status. A total number of 288 students from four boarding schools were randomly selected by using cluster sampling method in Chongqing, and they were assigned into supplement group and control group non-randomly. Students in supplement group received a single 200,000 international units vitamin A and 1 egg/day (including weekends) for 6 months. The control group did not receive any supplementation. We measured hemoglobin, serum retinol and height and weight at baseline and after supplementation. The supplementation increased the mean hemoglobin concentration by 7.13 g/L compared with 1.38 g/L in control group (p<0.001), the mean serum retinol concentration by 0.31 µmol/L compared with 0.09 µmol/L in the control group (p=0.005), the mean height-for-age z score by 0.05 compared with 0.03 in the control group (p=0.319), the mean weight-for-age z score by 0.05 compared with -0.12 in the control group (p<0.001). Our results revealed that egg and vitamin A supplementation is an effective, convenient, and practical method to improve the levels of hemoglobin, serum retinol and prevent the deterioration of growth in terms of weight for primary and middle school students from outlying poverty-stricken areas. Our intervention did not have a beneficial effect on linear growth.

Effects of vitamin A, vitamin A plus zinc, and multiple micronutrients on anemia in preschool children in Chongqing, China.

This study is to clarify the impact of vitamin A or vitamin A combined with other micronutrients supplementation on anemia and growth in preschoolers. In the present study, a total of 290 preschoolers, aged 36-72 months old were randomly assigned to 3 treatment groups: vitamin A (A group), vitamin A plus zinc (AZ group), and vitamin A combined with additional multiple-micronutrient (AMM group). After 6-month supplementation, the height and height-for-age z-score gains of the AZ group were significantly higher than the other groups; the weight gain of the AMM group was greater than the other groups. Compared with baseline values, the concentrations of hemoglobin, and zinc at the end significantly increased in all 3 groups. The incremental concentrations of hemoglobin in the AMM group were significant higher than in the other two groups. Furthermore, the incremental concentrations of serum retinol in the AMM group, and the increase in serum zinc concentrations in the AZ group were significantly higher, respectively, than in the other groups. These 3 kinds of supplements in the present study are effective in enhancing height gains and are effective in reducing the prevalence of anemia. Supplementation of zinc plus vitamin A is a better way for improving children's height and height-for-age z-score. Vitamin A combined with multiple-micronutrient is more effective in improving the hemoglobin concentrations in preschool children.