Xinrong Pei

Ethanol exposure induces differential microRNA and target gene expression and teratogenic effects which can be suppressed by folic acid supplementation

BACKGROUND microRNAs (miRNAs) play an important role in development and are associated with birth defects. Data are scant on the role of miRNAs in birth defects arising from exposure to environmental factors such as alcohol. METHODS In this study, we determined the expression levels of 509 mature miRNAs in fetal mouse brains with or without prenatal ethanol exposure using a miRNA microarray technique, verified by northern blot and PCR. Mouse embryos in culture were used to examine the effect of ethanol treatment on expression of the putative target genes of miR-10a (Hoxa1 and other Hox members) at mRNA and protein level. Open field and Morris water maze tests were also performed at post-natal day 35. RESULTS Ethanol treatment induced major fetal teratogenesis in mice and caused mental retardation in their offspring, namely lower locomotor activity (P < 0.01) and impaired task acquisition. Of the screened miRNAs, miR-10a, miR-10b, miR-9, miR-145, miR-30a-3p and miR-152 were up-regulated (fold change >1.5) in fetal brains with prenatal ethanol exposure, whereas miR-200a, miR-496, miR-296, miR-30e-5p, miR-362, miR-339, miR-29c and miR-154 were down-regulated (fold change <0.67). Both miR-10a and miR-10b were significantly up-regulated (P < 0.01) in brain after prenatal ethanol exposure. Ethanol treatment also caused major obstruction in the development of cultured embryos, with down-regulated Hoxa1. Co-incubation with folic acid blocked ethanol-induced teratogenesis, with up-regulated Hoxa1 and down-regulated miR-10a (P < 0.01). CONCLUSIONS The study provided new insights into the role of miRNAs and their target genes in the pathogenesis of fetal alcohol syndrome.

Long-term green tea catechin administration prevents spatial learning and memory impairment in senescence-accelerated mouse prone-8 mice by decreasing Aβ1-42 oligomers and upregulating synaptic plasticity–related proteins in the hippocampus

The senescence-accelerated mouse prone-8 (SAMP8) is characterized by early onset of learning and memory deficits along with spontaneous overproduction of soluble beta-amyloid peptide (Abeta) in the brain. In our study, 4 month old male SAMP8 mice were orally administered 0.05% and 0.1% green tea catechins (GTC, w/v) in drinking water for 6 months. We found that a supplementation with 0.05% or 0.1% GTC prevented spatial learning and memory impairments of mice in the Morris water maze. Better performance of GTC-treated mice was associated with decreased levels of Abeta(1-42) oligomers in the hippocampus. The activity of the protein kinase A/cAMP-response element binding protein (PKA/CREB) pathway, one of the molecular targets of Abeta oligomers which is crucial for late long-term potentiation and long-term memory formation, was significantly increased after GTC administration. We also found that chronic 0.05% or 0.1% GTC consumption prevented the reductions of three representative proteins of synaptic function and synaptic structure, including brain-derived neurotrophic factor(BDNF), post-synaptic density protein-95 (PSD95) and Ca(2+)/calmodulin-dependent protein kinase II (CaMKII). These results demonstrated that long-term 0.05% or 0.1% green tea catechin administration may prevent spatial learning and memory decline of SAMP8 mice by decreasing Abeta(1-42) oligomers and upregulating synaptic plasticity-related proteins in the hippocampus.

Long-term administration of green tea catechins prevents age-related spatial learning and memory decline in C57BL/6 J mice by regulating hippocampal cyclic amp-response element binding protein signaling cascade.

Flavonoid-rich foods have been shown to be effective at reversing age-related deficits in learning and memory in both animals and humans. However, little investigation of the preventative effects of flavonoids on the naturally aged animals was reported. In our study, 14-month-old female C57BL/6 J mice were orally administered 0.025%, 0.05% and 0.1% green tea catechins (GTC, w/v) in drinking water for 6 months; we found that a supplementation with 0.05% or 0.1% GTC prevented age-related spatial learning and memory decline of mice in the Morris water maze. Better performance of GTC-treated mice was associated with increased levels of cAMP-response element binding protein (CREB) phosphorylation in the hippocampus. The expressions of brain-derived neurotrophic factor (BDNF) and Bcl-2, two target genes of CREB which can exhibit long-term regulatory roles in synaptic plasticity and synaptic structure, were also increased. We also found that long-term 0.05% or 0.1% GTC administration prevented age-related reductions of two representative post-synaptic density proteins PSD95 and Ca(2+)/calmodulin-dependent protein kinase II, suggesting that synaptic structural changes may be involved. These results demonstrated that long-term 0.05% or 0.1% green tea catechin administration may prevent age-related spatial learning and memory decline of female C57BL/6 J mice by regulating hippocampal CREB signaling cascade.

Long-term ginsenoside administration prevents memory impairment in aged C57BL/6J mice by up-regulating the synaptic plasticity-related proteins in hippocampus

Memory impairment is considered to be one of the most prominent consequences of aging. Deterioration of memory begins in advance of old age in animals, including humans. Thus, it is extremely important to prevent memory decline for increasing healthy aging. Ginsenoside, the effective ingredient of ginseng, has been reported to have a neuron beneficial effect, but the preventive role on memory impairment and the underlying mechanisms have not been well determined. In the present study, C57BL/6J mice aged 12 months were chronically treated with ginsenoside 100mg/kg per day for 8 months. Placebo-treated aged mice, young and adult ones (4- and 8-month-old, respectively) were used as controls. The efficacious effect of ginsenoside was manifested in the amelioration of memory impairment in aged mice by Morris water maze and step-down tests. Compared with aged control group, the plasticity-related proteins including phospho-N-methyl-d-aspartate receptor1 (NMDAR1), phospho-calcium-calmodulin dependent kinase II (CaMK II), phospho-PKA catalytic beta subunit (PKA Cbeta), phospho-cAMP-response element binding protein (CREB) and brain derived neurotrophic factor (BDNF) in hippocampus significantly increased in ginsenoside treated group. These findings suggest that ginsenoside is effective on the prevention of age-related memory impairment, and the up-regulation of plasticity-related proteins in hippocampus may be one of the mechanisms.

Effects of cod bone gelatin on bone metabolism and bone microarchitecture in ovariectomized rats

Several animal studies have showed that gelatin may be effective for minimizing bone loss in OVX rats with established osteopenia. To gain insight into how cod bone gelatin administration affects bone loss after ovariectomy, studies were carried out focusing on bone quality and the molecular mechanisms. Eighty-four female rats were ovariectomized, 12 sham-operated, divided into six groups of 12 each and treated one week after ovariectomy either with vehicle or cod bone gelatin (0.375, 0.75, 1.5, 3, 6 mg/kg body weight) for 90 days. Bone densitometry, microCT analysis, real-time PCR analysis and biochemical analysis were used at the end of the study. After 90 days, BMD of proximal tibia and femoral neck decreased in OVX rats, whereas the loss of BMD in those regions was prevented at 3 g/kg (P<0.05). However, the BMD of midshaft femurs showed no significant differences. BV/TV, Tb.N. and Tb.Th. in the 3 g/kg group were, respectively, 30.4% (P<0.05), 145.5% (P<0.05) and 81.5% (P<0.05) higher than in the OVX group. A significant decrease was detected in urine CTX, NTX and DPD, suggesting decreased bone resorption. Treatment with 3 g/kg and 6 g/kg cod bone gelatin attenuated the increase in serum IL-1beta, IL-6 and TNF-alpha observed in the OVX group. Real-time PCR showed significantly decreased levels of mRNA expression for RANKL at the dosage of 6 g/kg and the RANKL/OPG mRNA ratio in the 3 g/kg and 6 g/kg group significantly decreased compared to the OVX group (P<0.05). In conclusion, our data confirmed that the cod bone gelatin treatment at 3 g/kg is effective in the prevention of estrogen deficient bone loss by modulating the expression of RANKL and OPG and suppressing the release of proinflammatory cytokines.

Protective effect of a marine oligopeptide preparation from Chum Salmon (Oncorhynchus keta) on radiation‐induced immune suppression in mice

BACKGROUND A marine oligopeptide preparation (MOP) obtained from Chum Salmon (Oncorhynchus keta) by the method of enzymatic hydrolysis, has been found to enhance the innate and adaptive immunities through stimulation of the secretion of cytokines in mice. The current study aimed to further investigate the protective effect of MOP on radiation-induced immune suppression in mice. RESULTS Female ICR mice (6-8 weeks old) were randomly divided into three groups, i.e. blank control, irradiation control and MOP (1.350 g kg(-1) body weight) plus irradiation-treated group. MOP significantly increased the survival rate and prolonged the survival times for 30 days after irradiation, and lessened the radiation-induced suppression of T- or B-lymphocyte proliferation, resulting in the recovery of cell-mediated and humoral immune functions. This effect may be produced by augmentation of the relative numbers of radioresistant CD(4) (+) T cells, enhancement of the level of immunostimulatory cytokine, IL-12, reduction of the level of total cellular NF-κB through the induction of IκB in spleen and inhibition of the apoptosis of splenocytes. CONCLUSION We propose that MOP be used as an ideal adjuvant therapy to alleviate radiation-induced injuries in cancer patients.

Antioxidant effect of a marine oligopeptide preparation from chum salmon (Oncorhynchus keta) by enzymatic hydrolysis in radiation injured mice.

Marine oligopeptide preparation (MOP) obtained from Chum Salmon (Oncorhynchus keta) by the method of enzymatic hydrolysis, has been found to possess a radioprotective property through stimulation of the radiation-induced immunosuppression. The current study aimed to further investigate the free radicals scavenging and antioxidant effects of MOP in radiation injured mice. Female ICR mice (6–8 weeks old) were randomly divided into 5 groups, i.e., blank control, irradiation control and MOP (0.225, 0.450 and 1.350 g/kg body weight) plus an irradiation-treated group. The result revealed that MOP significantly increased the white blood cell counts after irradiation, and lessened the radiation-induced oxidative damage. These effects may be caused by augmentation of the activities of antioxidant enzymes, such as SOD and GSH-Px, reduction of the lipid peroxidation (MDA level) in liver, and protection against radiation-induced apoptosis. Therefore, we propose that MOP be used as an ideal antioxidant to alleviate radiation-induced oxidation damage in cancer patients.

A Chronic Oral Toxicity Study of Marine Collagen Peptides Preparation from Chum Salmon (Oncorhynchus keta) Skin Using Sprague-Dawley Rat

Due to the increased consumption of marine collagen peptides preparation (MCP) as ingredients in functional foods and pharmaceuticals, it was necessary to carry out safety requirements in the form of an oral chronic toxicity assessment. In order to define the oral chronic toxicity of MCP, a 24-month feeding study of MCP was carried out. Sprague-Dawley (S-D) rats at the age of four-week of both sexes were treated with MCP at the diet concentrations of 0%, 2.25%, 4.5%, 9% and 18% (wt/wt). The actual food intake and bodyweight of the individual animals were recorded periodically until sacrifice. Blood and urine samples were collected for serum chemistry evaluations and urinalysis. Throughout the experimental period, there was no toxicologically significant difference between the vehicle and MCP-treated animals with respect to the survival rate, body weight, food consumption, urinalysis, clinical biochemistry parameter and relative organ weight in either sex. Moreover, incidences of non-neoplastic lesions in MCP-treated groups did not significantly increase compared with the control group. Under the present experimental conditions, no higher risk of chronic toxic effects was observed in MCP-treated rats at the diet concentrations of 2.25%, 4.5%, 9% and 18% (wt/wt) than in the rats fed with basal rodent diet.