Xiaoping Wei

Antioxidant vitamin status during pregnancy in relation to cognitive development in the first two years of life

OBJECTIVE To investigate the correlation of the antioxidant vitamins status (vitamins A, E and C) during pregnancy and the intellectual development of early childhood. METHOD A total of 150 paired maternal-neonatal subjects were recruited into the present study. The serum concentrations of antioxidant vitamins (vitamins A, E and C) in maternal blood and cord blood after delivery were determined by high performance liquid chromatography and the intellectual development was evaluated by Gesell Development Schedules (GDS) at two-years-old. RESULT Children with higher cord serum vitamin E level showed higher scores of motor, adaptive domain and average compared to children with lower cord serum vitamin E level (p<0.01 or 0.05), respectively. Cord serum vitamin A level had significant positive correlation with effect on motor DQs (beta=4.227, p<0.05), and vitamin E level in cord blood showed a positive relation with motor DQ and average DQ (beta=0.329 and 0.1875, respectively, p<0.05) in multiple linear regression model. The language and social DQs were influenced by placental vitamin E transport rate (beta=3.1968 and 3.0194, respectively, p<0.05). The placental transport rate of vitamin E also was a protective factor for the prevalence of motor behavior developmental delay [OR: 0.118, 95% confident interval (95% CI), 0.018-0.765, p=0.0251], personal and social behavior developmental delay (OR: 0.052, 95% CI: 0.004-0.610, p=0.0185) and average developmental delay (OR: 0.041, 95% CI: 0.003-0.642, p=0.0229) in logistic multiple regression model. CONCLUSION Data suggested that vitamin A, E status and vitamin E transfer rate at delivery had beneficial influence on childrens cognitive and behavior development quotients.

Immortalized mesenchymal stem cells: an alternative to primary mesenchymal stem cells in neuronal differentiation and neuroregeneration associated studies

BackgroundMesenchymal stem cells (MSCs) can be induced to differentiate into neuronal cells under appropriate cellular conditions and transplanted in brain injury and neurodegenerative diseases animal models for neuroregeneration studies. In contrast to the embryonic stem cells (ESCs), MSCs are easily subject to aging and senescence because of their finite ability of self-renewal. MSCs senescence seriously affected theirs application prospects as a promising tool for cell-based regenerative medicine and tissue engineering. In the present study, we established a reversible immortalized mesenchymal stem cells (IMSCs) line by using SSR#69 retrovirus expressing simian virus 40 large T (SV40T) antigen as an alternative to primary MSCs.MethodsThe retroviral vector SSR#69 expressing simian virus 40 large T (SV40T) antigen was used to construct IMSCs. IMSCs were identified by flow cytometry to detect cell surface makers. To investigate proliferation and differentiation potential of IMSCs, cell growth curve determination and mesodermal trilineage differentiation tests were performed. Neuronal differentiation characteristics of IMSCs were detected in vitro. Before IMSCs transplantation, we excluded its tumorigenicity in nude mice firstly. The Morris water maze tests and shuttle box tests were performed five weeks after HIBD models received cells transplantation therapy.ResultsIn this study, reversible IMSCs were constructed successfully and had the similar morphology and cell surface makers as primary MSCs. IMSCs possessed better ability of proliferation and anti-senescence compared with primary MSCs, while maintained multilineage differentiation capacity. Neural-like cells derived from IMSCs had similar expressions of neural-specific genes, protein expression patterns and resting membrane potential (RMP) compared with their counterparts derived from primary MSCs. There was no bump formation in nude mice subcutaneously injected with IMSCs. IMSCs played same role as primary MSCs to improve learning ability and spatial memory of HIBD rats.ConclusionsIMSCs not only retain their features of primary MSCs but also possess the ability of high proliferation and anti-senescence. IMSCs can definitely be induced to differentiate into neuronal cells in vitro and take the place of primary MSCs for cell transplantation therapy without tumorigenesis in vivo. The stable cell line is particularly useful and valuable as an alternative to MSCs in neuronal differentiation and neuroregeneration associated studies.

Perinatal vitamin A status in relation to neurodevelopmental outcome at two years of age.

UNLABELLED Information about the effect of antioxidant vitamins nutrition during pregnancy on offsprings intellectual development is extremely limited. OBJECTIVE To investigate the correlation of antioxidant vitamins (Vitamin A, E and C) at delivery and the neurodevelopment of early childhood. METHOD A total of 158 paired maternal-neonatal subjects were recruited. The serum concentrations of vitamin A, E and C in maternal and cord blood after delivery were determined and intellectual development was evaluated by Gesell Development Schedule (GDS) at two years old. RESULT After adjusting for potential confounders, vitamin A placental transport ratio (VA-PTR) was positively associated with motor area development quotients (DQ) and average DQ(p<0.01). Cord VA level was positively related with language area and social area DQ (p<0.05). Nevertheless, there was no significant association between cord VE, VC levels, VE PTR or VC PTR and GDS. The adaptive area and average DQ in high cord VA group was higher than those in low VA group (p<0.05). Cord VA level and VA-PTR were positively associated with birth head circumference and birth weight, respectively. CONCLUSION Our data suggested that adequate vitamin A at delivery had beneficial influence on neonatal birth outcomes and childrens neurodevelopment in later childhood.

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 β 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 β. Furthermore, we found that retinoic acid receptor β 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 β 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.

Gestational vitamin A deficiency reduces the intestinal immune response by decreasing the number of immune cells in rat offspring

OBJECTIVES Vitamin A (VA) is a critical micronutrient for life, especially during growth and development. There is a close relationship between VA deficiency (VAD) and the morbidity of diarrhea in the clinical setting. However, the regulatory mechanisms of VA are not clearly understood. METHODS Specific-pathogen-free Wistar rats received a diet with or without VA before gestation. The offspring were submitted to an abdominal injection of Escherichia coli lipopolysaccharide. After the challenge, which lasted for 12 h, the serum retinol was detected by high-performance liquid chromatography, and the level of immunoglobulin A in the stool was analyzed by enzyme-linked immunosorbent assay. The lymphocyte immunophenotypes were evaluated with the use of flow cytometry with samples collected from the spleen, the mesenteric lymph nodes, Peyer patches, and intestinal intraepithelial lymphocytes. RESULTS Early life VAD, independent of the lipopolysaccharide challenge, significantly decreased serum retinol level and CD8(+) intestinal intraepithelial lymphocytes. The level of immunoglobulin A secretion and percentages of splenic CD4(+)CD8(+) T cells were affected by the interaction effects of the lipopolysaccharide challenge and VAD treatment. Gestational VAD significantly increased the percentages of B cells in the mesenteric lymph nodes and decreased the percentages of CD11 C(+) dendritic cells and CD4(+)CD25(+) T cells from the Peyer patches. The lipopolysaccharide challenge only significantly increased percentages of splenic CD4(+)CD25(+) T cells. The intestinal tissue of the pups with VAD displayed mild inflammation. CONCLUSIONS Gestational or early life VAD decreases the numbers of immune cells in offspring, which may partly suppress the activities of the mucosal immune responses in the intestine. This suggests that more attention should be given to the VA nutritional state of children and women of reproductive age.

Serum Vitamin A Status is Associated with Obesity and 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.

Vitamin A supplementation in early life enhances the intestinal immune response of rats with gestational vitamin A deficiency by increasing the number of immune cells.

Vitamin A is a critical micronutrient for regulating immunity in many organisms. Our previous study demonstrated that gestational or early-life vitamin A deficiency decreases the number of immune cells in offspring. The present study aims to test whether vitamin A supplementation can restore lymphocyte pools in vitamin A-deficient rats and thereby improve the function of their intestinal mucosa; furthermore, the study aimed to identify the best time frame for vitamin A supplementation. Vitamin A-deficient pregnant rats or their offspring were administered a low-dose of vitamin A daily for 7 days starting on gestational day 14 or postnatal day 1, day 14 or day 28. Serum retinol concentrations increased significantly in all four groups that received vitamin A supplementation, as determined by high-performance liquid chromatography. The intestinal levels of secretory immunoglobulin A and polymeric immunoglobulin receptor increased significantly with lipopolysaccharide challenge in the rats that received vitamin A supplementation starting on postnatal day 1. The rats in this group had higher numbers of CD8+ intestinal intraepithelial lymphocytes, CD11C + dendritic cells in the Peyers patches and CD4+CD25+ T cells in the spleen compared with the vitamin A-deficient rats; flow cytometric analysis also demonstrated that vitamin A supplementation decreased the number of B cells in the mesenteric lymph nodes. Additionally, vitamin A supplementation during late gestation increased the numbers of CD8+ intestinal intraepithelial lymphocytes and decreased the numbers of B lymphocytes in the mesenteric lymph nodes. However, no significant differences in lymphocyte levels were found between the rats in the other two vitamin A supplement groups and the vitamin A-deficient group. In conclusion, the best recovery of a subset of lymphocytes in the offspring of gestational vitamin A-deficient rats and the greatest improvement in the intestinal mucosal immune response are achieved when vitamin A supplementation occurs during the early postnatal period.

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.

Adenovirus-mediated RAR-β over-expression enhances ATRA-induced neuronal differentiation of rat mesenchymal stem cells.

Introduction The retinoic acid (RA) signaling pathway plays important roles in neural development. All-trans retinoic acid (ATRA) activates the RA signal by regulating RAR-β in mesenchymal stem cell (MSC)-derived neuron cells. Here, we try to investigate whether RAR-β over-expression can affect neuronal differentiation of MSCs. Material and methods The RAR-β gene was constructed into adenovirus Ad-RAR-β by using the AdEasy system. The MSCs were infected with Ad-RAR-β. Real time-polymerase chain reaction (RT-PCR), Western blot and immunofluorescence were performed to detect the expression and localization of RAR-β. The MSCs were treated with 1 µmol/l ATRA and modified neuronal induction medium (MNM). Soma size and axon length of induced neurons were measured. Neural specific markers were detected by RT-PCR, western blot and immunofluorescence to evaluate neuronal differentiation. Results The 1300 bp fragment of RAR-β gene was confirmed to be correctly cloned in the adenovirus vector. Cloudiness amplification of Ad-RAR-β was observed in HEK293 cells during package. After 48 h of Ad-RAR-β infection, about 70% of MSCs were RFP-positive. RAR-β expression was increased by about 1988-fold and located in the nucleus. RAR-β over-expression did not affect neuronal differentiation efficiency; however, soma size of induced neuron cells enlarged from 716.25 ±95.96 µm2 to 1160.12 ±352.65 µm2 and axon length from 64.17 ±11.88 µm to 83.98 ±13.69 µm. Neural markers other than nestin – NSE, MAP-2, Tau, and Tuj1 – were increased by 4- to 11-fold in RAR-β over-expressed neuron cells with ATRA/MNM induction compared with the Ad-null control group. Conclusions Our results have demonstrated that adenovirus-mediated RAR-β over-expression could facilitate neuron cell types of MSCs in vitro, indicating that the RAR-β-activated RA signal might be a vital factor in neuronal differentiation.

Mesenchymal stromal cell neuroprotection of hydrogen peroxide -challenged pheochromocytoma cells through reducing apoptosis and releasing cytokines

BACKGROUND AIMS Immunoregulation of mesenchymal stromal cells (MSC) is more efficient at restoring biologic function of injured tissue than transdifferentiation during transplantation. However, the exact mechanisms and characteristics of MSC regarding immunomodulation are still unknown, especially in the damaged niche after hypoxic-ischemic insult. We investigated the anti-apoptotic actions of MSC against the neurotoxicity of hydrogen peroxide (H(2)O(2)) on pheochromocytoma (PC12) cells. METHODS To mimic hypoxic-ischemic brain injury in vivo, a relatively high H(2)O(2) concentration and short period were used to treat PC12 cells. MSC were co-cultured directly with the injured PC12 cells, and 5-(3-carboxymethoxyphenyl)-2-(4,5-dimethylthiazoly)-3-(4-sulfophenyl)tetrazolium, inner salt (MTS), lactose dehydrogenase (LDH) and nitric oxide (NO) assays, intracellular Ca(2+) and resting membrane potential (RMP) were analyzed. Apoptotic-associated genes and cytokine releases were detected by reverse transcriptase-polymerase chain reaction (RT-PCR) and enzyme-linked immunosorbent assay (ELISA). RESULTS After exposure to H(2)O(2), the viability of PC12 cells was significantly decreased, while the levels of LDH and NO increased, resulting in intracellular Ca(2+) accumulation and cell apoptosis. Co-culture of MSC with the H(2)O(2)-treated PC12 cells sustained viability of the PC12 cells, reduced LDH levels and NO release, and improved Ca(2+) influx and cell apoptosis. The injured PC12 cells exhibited lower RMP following co-culture with MSC compared with the injured PC12 cells alone. The mRNA expression levels of Bcl-2 were up-regulated and caspase-3 levels down-regulated in the MSC co-culture groups. The release of interleukin (IL)-10 was gradually reduced by co-cultured MSC, while the release of IL-6 was sharply increased following MSC co-culture. CONCLUSIONS These findings indicate that MSC have neuroprotective effects on suppressing cell apoptosis via regulation of the H(2)O(2)-impaired microenvironment, partly through IL-6 and IL-10 cytokine production.