Antenatal taurine supplementation for improving brain ultrastructure in fetal rats with intrauterine growth restriction

Changes in brain ultrastructure of fetal rats with intrauterine growth restriction (IUGR) were explored and the effects of antenatal taurine supplementation on their brain ultrastructure were determined. Fifteen pregnant rats were randomly divided into three groups: control group, IUGR model group and IUGR group given antenatal taurine supplements. Taurine was added to the diet of the taurine group at a dose of 300 mg/kg/d from 12 days after conception until natural delivery. Transmission electron microscopy was used to observe ultrastructural changes in the brains of the newborn rats. At the same time, brain cellular apoptosis was detected using TUNEL, and the changes in protein expression of neuron specific enolase and glial fibrillary acidic protein were analyzed using immunohistochemistry. The results showed that: 1) The average body weight and cerebral weight were significantly lower in the IUGR group than in the control group (p<0.01) and both of them were less so after taurine was supplemented (p<0.01). 2) Transmission electron microscopy revealed that brain cortex structures were sparse IUGR rats, showing many scattered apoptotic cells, decreased numbers of synapses, lower glial cell proliferation, and fewer neurons, more sparsely arranged, while these factors were significantly improved with taurine supplementation. 3) The results of TUNEL showed that the counts of apoptotic brain cells in IUGR groups were significantly increased from those in control groups and that taurine could significantly decrease brain cell apoptosis (p<0.001). 4) The results of immunohistochemistry showed that antenatal taurine-supplementation could significantly increase the counts of neuron specific enolase and glial fibrillary acidic protein immunoreactive cells in fetal rats with IUGR (p<0.001). It can be concluded that it IUGR has a significant detrimental influence on the development of fetal rat brains, and antenatal supplement of taurine can significantly improve the IUGR fetal brain development.

Acute restraint stress increases intrahypothalamic oestradiol concentrations in conjunction with increased hypothalamic oestrogen receptor β and aromatase mRNA expression in female rats

Activation of the hypothalamic-pituitary-adrenal axis is considered to be one of the key physiological responses to stress and, interestingly, shows a marked sex difference. Oestradiol plays an important role in this sex difference. The present study investigated the systemic and intrahypothalamic oestradiol response to physical restraint stress in female rats. We used jugular catheterisation and intrahypothalamic microdialysis to simultaneously measure plasma oestradiol and local oestradiol concentrations in the paraventricular nucleus (PVN) of the hypothalamus. We also assessed corticotrophin-releasing hormone (CRH), aromatase, and oestrogen receptor (ER) α and β mRNA expression in the PVN by quantitative polymerase chain reaction immediately after the acute stress period. As expected, PVN CRH mRNA and plasma corticosterone were significantly increased after acute stress. Interestingly, the local oestradiol concentration in the PVN also increased during the 1-h stress period in pro-oestrus and in ovariectomised (OVX) animals. Aromatase mRNA expression in the PVN was increased markedly in pro-oestrus but only modestly in oestrus. PVN ERβ but not ERα mRNA expression was significantly elevated in pro-oestrous animals. In addition, plasma oestradiol levels increased 10 min after stress, both during pro-oestrus and oestrus but not in OVX animals. To conclude, we report an intra-hypothalamic oestradiol response to restraint stress. The rising hypothalamic oestradiol concentration together with increased ERβ gene expression indicates a positive feedback of hypothalamic oestradiol signalling during acute stress in rats.

Free energy of nascent-chain folding in the translocon

During their synthesis, many water-soluble proteins and nearly all membrane proteins transit through a protein-conducting channel in the membrane, the Sec translocon, from where they are inserted into the lipid bilayer. Increasing evidence indicates that folding of the nascent protein begins already within the ribosomal exit tunnel in a sequence- and environment-dependent fashion. To examine the effects of the translocon on the nascent-chain folding, we have calculated the potential of mean force for α-helix formation of a 10-alanine oligopeptide as a function of its position within the translocon channel. We find that the predominant conformational states, α-helical and extended, reflect those found for the peptide in water. However, the translocon, via its surface properties and its variable diameter, shifts the equilibrium in favor of the α-helical state. Thus, we suggest that the translocon facilitates not only the insertion of membrane proteins into the bilayer but also their folding.

Mitochondrial nutrients stimulate performance and mitochondrial biogenesis in exhaustively exercised rats

The aim of this study was to investigate the effects of a combination of nutrients on physical performance, oxidative stress and mitochondrial biogenesis in rats subjected to exhaustive exercise. Rats were divided into sedentary control (SC), exhaustive exercise (EC) and exhaustive exercise with nutrient supplementation (EN). The nutrients include (mg/kg/day): R-α-lipoic acid 50, acetyl-L-carnitine 100, biotin 0.1, nicotinamide 15, riboflavin 6, pyridoxine 6, creatine 50, CoQ10 5, resveratrol 5 and taurine 100. Examination of running distances over the 4-week period revealed that EN rats ran significantly longer throughout the entire duration of the exhaustive exercise period compared with the EC rats. Nutrient supplementation significantly inhibited the increase in activities of alanine transaminase, lactate dehydrogenase and creatine kinase, reversed increases in malondialdehyde, inhibited decreases in glutathione S-transferase and total antioxidant capacity in plasma, and suppressed the elevation of reactive oxygen species and apoptosis in splenic lymphocytes. Nutrient supplementation increased the protein expression of mitochondrial complexes I, II and III, mtDNA number and transcription factors involved in mitochondrial biogenesis and fusion in skeletal muscle. These findings suggest that mitochondrial nutrient supplementation can reduce exhaustive exercise-induced oxidative damage and mitochondrial dysfunction, thus leading to enhancement of physical performance and of fatigue recovery.

Replication of 13 obesity loci among Singaporean Chinese, Malay and Asian-Indian populations

OBJECTIVE

Recent genome-wide association studies (GWAS) have identified 38 obesity-associated loci among European populations. However, their contribution to obesity in other ethnicities is largely unknown.

METHODS

We utilised five GWAS (N=10 482) from Chinese (three cohorts, including one with type 2 diabetes and another one of children), Malay and Indian ethnic groups from Singapore. Data sets were analysed individually and subsequently in combined meta-analysis for Z-score body-mass index (BMI) associations.

RESULTS

Variants at the FTO locus showed the strongest associations with BMI Z-score after meta-analysis (P-values 1.16 × 10(-7)-7.95 × 10(-7)). We further detected associations with nine other index obesity variants close to the MC4R, GNPDA2, TMEM18, QPCTL/GIPR, BDNF, ETV5, MAP2K5/SKOR1, SEC16B and TNKS/MSRA loci (meta-analysis P-values ranging from 3.58 × 10(-4)-1.44 × 10(-2)). Three other single-nucleotide polymorphisms (SNPs) from CADM2, PTBP2 and FAIM2 were associated with BMI (P-value ≤ 0.0418) in at least one dataset. The neurotrophin/TRK pathway (P-value=0.029) was highlighted by pathway-based analysis of loci that had statistically significant associations among Singaporean populations.

CONCLUSION

Our data confirm the role of FTO in obesity predisposition among Chinese, Malays and Indians, the three major Asian ethnic groups. We additionally detected associations for 12 obesity-associated SNPs among Singaporeans. Thus, it is likely that Europeans and Asians share some of the genetic predisposition to obesity. Furthermore, the neurotrophin/TRK signalling may have a central role for common obesity among Asians.

QTL mapping in outbred half-sib families using Bayesian model selection

In this article, we propose a model selection method, the Bayesian composite model space approach, to map quantitative trait loci (QTL) in a half-sib population for continuous and binary traits. In our method, the identity-by-descent-based variance component model is used. To demonstrate the performance of this model, the method was applied to map QTL underlying production traits on BTA6 in a Chinese half-sib dairy cattle population. A total of four QTLs were detected, whereas only one QTL was identified using the traditional least square (LS) method. We also conducted two simulation experiments to validate the efficiency of our method. The results suggest that the proposed method based on a multiple-QTL model is efficient in mapping multiple QTL for an outbred half-sib population and is more powerful than the LS method based on a single-QTL model.

NANOG is a key factor for induction of pluripotency in bovine adult fibroblasts

Since the first reports on isolation of pluripotent mouse embryonic stem (ES) cells 3 decades ago, there have been numerous attempts to derive ES cell lines from commercially important livestock species with limited success. The recent discovery that ectopic expression of a handful of stem cell-related genes was capable of inducing pluripotency in rodents and primates provided a novel approach to derivation of pluripotent stem cell lines. We used this approach in cattle and demonstrated that the ectopic expression of POU5F1 (also known as Oct4), SOX2, KLF4, and c-MYC alone was not sufficient for stable induction of pluripotency in bovine adult fibroblasts and that the additional expression of NANOG to the reprogramming cocktail was essential for the generation of stable bovine (b) induced pluripotent stem (iPS) cells. The resulting biPS cells were characterized by reverse-transcription PCR for a panel of ES marker genes. Immunocytochemical localization of POU5F1, SSEA-1, SSEA-4, and colorimetric alkaline phosphatase activity was measured in the iPS clones. The differentiation potential of the biPS cells was determined in vitro by expression of differentiation markers in embryoid bodies. Injection of biPS into immunocompromised mice resulted in teratomas containing cell types of the 3 germ lineages. This study reports the first generation of bovine induced pluripotent cell lines and paves the way for the use of biPS cells for biotechnological and agricultural purposes.

Bayes estimators for phylogenetic reconstruction

Tree reconstruction methods are often judged by their accuracy, measured by how close they get to the true tree. Yet, most reconstruction methods like maximum likelihood (ML) do not explicitly maximize this accuracy. To address this problem, we propose a Bayesian solution. Given tree samples, we propose finding the tree estimate that is closest on average to the samples. This "median" tree is known as the Bayes estimator (BE). The BE literally maximizes posterior expected accuracy, measured in terms of closeness (distance) to the true tree. We discuss a unified framework of BE trees, focusing especially on tree distances that are expressible as squared euclidean distances. Notable examples include Robinson-Foulds (RF) distance, quartet distance, and squared path difference. Using both simulated and real data, we show that BEs can be estimated in practice by hill-climbing. In our simulation, we find that BEs tend to be closer to the true tree, compared with ML and neighbor joining. In particular, the BE under squared path difference tends to perform well in terms of both path difference and RF distances.

Mixture model-based approach for optic cup segmentation

Glaucoma is a leading cause of blindness with permanent damage to optic nerve head. ARGALI is an automated computer-aided diagnosis system designed for glaucoma detection via optic cup-to-disc ratio assessment. It employs several methods to determine the optic cup and disc from retinal images.

miR-223 suppresses differentiation of tumor-induced CD11b⁺ Gr1⁺ myeloid-derived suppressor cells from bone marrow cells

Tumor-associated factors are related to increased accumulation of CD11b(+) Gr1(+) myeloid-derived suppressor cells (MDSCs). However, the exact mechanism of how genetic factors control the expansion of MDSCs in tumor-bearing hosts remains elusive. Herein, we found that tumor-associated MDSCs and their subsets, mononuclear MDSCs and polymorphonuclear MDSCs, have decreased expression of miR-223 when compared to CD11b(+) Gr1(+) cells from the spleen of disease-free mice. With the differentiation of CD11b(+) Gr1(+) MDSCs from bone marrow cells (BMCs) upon exposure to tumor-associated factors, the expression of both pri-miR-223 and mature miR-223 was downregulated, indicating that the expression of miR-223 could be regulated by tumor-associated factors. Interestingly, miR-223 remarkably inhibits differentiation of BMCs into CD11b(+) Gr1(+) MDSCs in the presence of tumor-associated factors by targeting myocyte enhancer factor 2C (MEF2C). Using reconstituted s.c. tumor models, miR-223 also suppresses accumulation of CD11b(+) Gr1(+) MDSCs, whereas its targeting molecule MEF2C increases the number of MDSCs. Tumor growth is slower in mice infused by miR223-engineered BMCs than in mice infused with control transfected BMCs. As miR-223 and its target molecule MEF2C are highly conserved between mice and humans, the modulation of miR-223 in tumor-induced CD11b(+) Gr1(+) MDSCs may exert an important role in controlling the increased accumulation of CD11b(+) Gr1(+) MDSCs in patients with tumor.

Involvement of mitogen-activated protein kinase activation in cyclooxygenase-2 and transforming growth factor-β production in alveolar macrophage from chronic bronchitis rats

OBJECTIVE

Lipopolysaccharides (LPS) activates several signaling pathways in macrophages including mitogen-activated protein kinases (MAPK). Previous studies have investigated effect of LPS on MAPK activation in macrophage of normal rats. In the current study, we investigated the effect of LPS exposure on activation of MAPK in alveolar macrophage (AM) of chronic bronchitis (CB) rats and researched the corresponding cyclooxygenase-2 (COX-2), prostaglandins-2 (PGE(2)) and transforming growth factor- β (TGF-β) production and their MAPK signal pathways.

METHODS

CB model was established by injection of Bacillus Calmette-Guerin (BCG) and LPS in rats. Special inhibitors of p38, extracellular signal-regulated kinase (ERK) and c-Jun-N-terminal kinases (JNK) MAPK signal pathways were used to determine the effect of MAPK activation on COX-2, PGE(2), TGF-β production in AM of CB rats via RT-PCR, western blotting, radioimmunoassay and ELISA.

KEY FINDINGS

Synthesis of PGE(2) from AM of CB rats was increased and suppressed by either PD98059 or SB203580. SB203580 and PD98059, (inhibitors of ERK and p38 MAPK), could significantly inhibit COX-2 mRNA and protein expression. Moreover, ERK and p38 MAPK had synergistic effect on COX-2 expression. Inhibitor of ERK MAPK signal transduction could inhibit TGF-β expression in AM.

CONCLUSION

These results demonstrated COX-2, PGE(2) and TGF-β productions in AM of CB rats were significantly increased, which might be regulated by the different MAPK signaling pathway.

Apoptosis: its functions and control in the ocular lens

The ocular lens is a non-vascular and non-innervated transparent organ that plays an important role in vision processing. This unique organ is derived from the embryonic ectoderm of the brain region through a complicated differentiation process in which apoptosis plays a key role. First, when the committed ectoderm becomes thickened and invaginated, the defined number of cells required to form the lens vesicle is partially determined by apoptosis. Second, separation of lens vesicle from the above corneal ectoderm is executed through apoptosis of the lens stalk cells. Finally, differentiation of the lens epithelial cells is controlled by the regulators, most of which are involved in control of apoptosis at multiple signaling steps. The lens is also characterized by continuous growth and differentiation in the adulthood. Through the different stages of growth and differentiation in the adult lens, various stress conditions can induce apoptosis of the lens epithelial cells, leading to eventual non-congenital cataractogenesis. The present review summarizes the current knowledge on the functions and regulators of apoptosis in the ocular lens.

High-risk human papillomavirus reduces the expression of microRNA-218 in women with cervical intraepithelial neoplasia

This study was designed to investigate whether there is a correlation between the down-regulation of microRNA-218 (miR-218) and the presence of human papillomavirus (HPV) infection in the pathogenesis of cervical cancer. The participants comprised 78 women with cervical intraepithelial neoplasia (CIN); 22 (28.2%) had CIN 1, 27 (34.6%) had CIN 2 and 29 (37.2%) had CIN 3. MiR-218 expression was determined by reverse transcriptase polymerase chain reaction and HPV genotypes in tissue specimens were identified with a microarray test kit. The findings showed that miR-218 levels in patients with high-risk HPV infection were lower than in those infected with low-risk or intermediate-risk HPV, or in those who were HPV-free. MiR-218 levels in patients with high-risk CIN were lower than in those with low-risk CIN. We concluded that infection with high-risk HPV lowered the expression of miR-218 and that down-regulation of miR-218 was involved in the pathogenesis of cervical cancer.

Immunostimulatory activities of specific bacterial secondary metabolite of Anoxybacillus flavithermus strain SX-4 on carp, Cyprinus carpio

AIMS

  To determine the capacity of secondary metabolite of strain SX-4, to enhance the nonspecific immunity and survival of carp (Cyprinus carpio), and to identify the constituents that are responsible.

METHODS AND RESULTS

  A thermophilic strain SX-4 that is able to produce immunostimulatory metabolite was isolated from sludge sample of hot spring and identified by comparison with 16S rRNA sequences (99% of homology) as Anoxybacillus flavithermus. Bioactivity-guided fractionation of methanol extract from its cell-free culture, one bacterial peptide with the capacity of improving the nonspecific immune responses and disease resistance (relative per cent survival = 66·67%) was obtained and the compound was characterized as cyclo-(L-Pro-Gly) by IR, ESI-MS, (1) H NMR and (13) C NMR spectroscopic analyses. After intraperitoneal administration of this peptide, selected innate immune parameters including phagocytic activity, superoxide anion production, serum lysozyme activity and serum SOD activity, along with immune-related genes expression (i.e. interleukin-1β and inducible nitric oxide synthase), in the blood were found to be significantly increased.

CONCLUSIONS

  The bacterial peptide cyclo-(L-Pro-Gly) significantly enhances nonspecific immunity and survival of carp.

SIGNIFICANCE AND IMPACT OF THE STUDY

  There is a possibility of using cyclo-(L-Pro-Gly) as a better natural immunostimulant, which could have a promising role in aquaculture to prevent diseases and disease outbreaks.

Seasonal abundance and activity of the tick Dermacentor silvarum in northern China

Studies on the seasonal abundance and activity of larvae, nymphs and adults of Dermacentor silvarum (Ixodida: Ixodidae), both on and off the host, were carried out over a 2-year period from February 2008 to January 2010 in northern China. During the study period, feeding ticks were removed weekly from domestic sheep and free-living ticks were collected weekly by flag-dragging in four different habitat types. Rodents were captured and inspected for immature ticks from June to September 2008. The results of this study suggest that the ticks mainly reside in shrubs and complete only one generation per year with sequential seasonal distribution and little overlap between the activity of the larvae and nymphs. Adults were most prevalent from late February to late May and peaked in number in mid-April. Larvae were found from early June to early September and peaked in number in mid-July. Nymphs were mainly distributed from late June to late September and peaked in mid-August. Adult and nymphal D. silvarum were found primarily on the ears of sheep, but no larvae were found on sheep. Additionally, an overwintering male adult population was detected on sheep after October, but no free-living adults were found by dragging.