Antioxidant micronutrients improve intrinsic and UV-induced apoptosis of human lymphocytes particularly in elderly people

OBJECTIVE

Aging and oxidative stress may lead to enhanced cellular damage and programmed cell death. To study the association of intrinsic apoptosis with age and the effect of antioxidant supplementation on intrinsic and UV-induced apoptosis in children, young and elderly people.

METHODS

The study was a 2 months, double-blind, randomized trial. Three age groups were studied: children, young adults and elderly people. A total of 274 healthy subjects were allocated to a group supplemented with moderate amounts of retinol, β-carotene, α-tocopherol, ascorbic acid and selenium or placebo. Plasma oxidative stress parameters were detected and apoptosis of lymphocytes was evaluated with TUNEL staining.

RESULTS

At baseline, percentages of intrinsic apoptosis were 13.8% and 11.1% in elderly and young people, respectively, both significantly higher than children (6.3%). A decrease of 1.7% and 2.3% in intrinsic apoptosis of lymphocytes was found in the supplemented groups of young and elderly people compared with their control groups (all p values <0.001), but no significant decrease in children. Moreover, percentages UV-induced apoptosis significantly decreased by 1.4%, 1.9% and 3.1% in children, young and elderly people, respectively, compared with control groups after the trial. There were considerable increments in concentrations of plasma β-carotene, retinol, tocopherol, ascorbic acid and selenium in all three treated groups after the supplementation.

CONCLUSIONS

Young and elderly people have a higher intrinsic apoptosis than children, which was improved by antioxidant supplementation. UV-induced damage was attenuated by the supplementation in all three age groups.

A naturally occurring nanomaterial from the Sundew (Drosera) for tissue engineering

In recent years advances have been made in the design of novel materials for tissue engineering through the use of polysaccharides. This study evaluated the ability of a naturally secreted polysaccharide adhesive from the Sundew (Drosera capensis) as a support for cell growth. The Sundew adhesive has several advantages including its high elasticity and antibiotic nature. By coating glass cover slips with the Sundew adhesive, a network of nanofibers was generated that was capable of promoting attachment and differentiation of a model neuronal cell line, PC-12. We also demonstrated the potential of this material for repairing bone and soft tissue injuries, by testing attachment of osteoblasts and endothelial cells. Finally, it was determined that the Sundew biomaterial was stable through testing by atomic force microscopy and prolonged cell growth. This work has proven the capabilities of using a nanomaterial derived from the Sundew adhesive for the purpose of tissue engineering.

Interleukin-10 polymorphisms and tuberculosis susceptibility: a meta-analysis

BACKGROUND

A large number of studies have shown that polymorphisms in the interleukin 10 (IL-10) gene are implicated in susceptibility to tuberculosis (TB). However, the results are inconsistent and inconclusive.

OBJECTIVE

A meta-analysis was performed to analyse the association between polymorphisms in the IL-10 gene and TB susceptibility.

RESULTS

A total of 18 studies that referred to three polymorphisms (-1082G/A, -819C/T and -592A/C) were identified. No association was found between these three polymorphisms and TB risk in combined analyses: -1082G/A (AA+AG vs. GG): OR 0.87, 95%CI 0.66-1.14, P = 0.30; -819C/T (TT+TC vs. CC): OR 1.02, 95%CI 0.92-1.14, <e1>P</e> = 0.66; -592A/C (CC+CA vs. AA): OR 0.99, 95%CI 0.88-1.11, P = 0.82. However, in the subgroup analysis by ethnicity, European subjects with the -1082(AA+GG) genotypes have a decreased risk of TB: OR 0.55, 95%CI 0.35-0.88, P = 0.01.

CONCLUSION

This meta-analysis suggests that the -1082G/A polymorphism of the IL-10 gene could be a risk factor for TB in Europeans. Further studies with larger populations are required to assess the association between IL-10 polymorphisms and TB susceptibility.

Secreted glyceraldehyde-3-phosphate dehydrogenase as a broad spectrum vaccine candidate against microbial infection in aquaculture

AIMS

Subcellullar localizations and cross-immunities of GAPDHs from six common pathogenic bacteria in aquaculture were investigated.

METHODS AND RESULTS

Subcellullar localizations of GAPDHs of Edwardsiella tarda EIB202, Edwardsiella ictaluri ATCC33202, Aeromonas hydrophila LSA34, Vibrio anguillarum MVM425, Vibrio alginolyticus EPGS020401 and Vibrio harveyi VIB647 were analysed with Western blotting, indirect immunofluorescence and flow cytometry examinations. Immunoprotections of different recombinant GAPDHs against these pathogens were investigated with zebrafish model. Western blotting of subcellular extractions showed that all GAPDHs were secreted into extracellular medium and periplasmic space. In addition, GAPDHs were demonstrated to distribute in the outer membranes except MVM425 and VIB647. And, GAPDHs were confirmed to be present on the surface of these bacteria with indirect immunofluorescence and flow cytometry examinations. The remarkable cross-protective immunities of these recombinant GAPDHs were induced in zebrafish, and the relative protective survivals were almost over 60%.

CONCLUSIONS

Localizations of GAPDHs from these pathogenic bacteria were similar to many other causative agents. And, GAPDHs could be important protective antigens and give remarkable cross-immunity against different pathogens.

SIGNIFICANCE AND IMPACT OF THE STUDY

Recombinant GAPDH could be designed as a broad spectrum vaccine candidate against multiple microbial infections in aquaculture.

Associations of miRNA polymorphisms and female physiological characteristics with breast cancer risk in Chinese population

mircoRNAs (miRNAs) play important roles on regulation of gene expressions. Aberrant expression of miRNAs was involved in various biological and pathological processes, including tumorigenesis of breast cancer. Single-nucleotide polymorphisms (SNPs) were implicated in altered expression or biological functions of mature miRNAs. To explore the relevance of miRNA polymorphisms and female physiological characteristics to breast cancer risk, SNPs located within hsa-miR-605 (rs2043556), hsa-miR-149 (rs2292832), hsa-miR-27a (rs895819), hsa-miR-196a-2 (rs11614913) and hsa-miR-618 (rs2682818) were selected, and their associations with breast cancer risk were analysed. In addition, associations between physiological characteristics-related factors and breast cancer risk were estimated too. We found that the ones with menarche age less than 16 years had increased breast cancer risk (OR = 2.10, 95% CI: 1.23-3.60). Marginally significant association between rs11614913 CT/CC genotypes and reduced breast cancer risk was observed (OR = 0.65, 95% CI: 0.40-1.06), while no significance was detected about the other miRNA polymorphisms. We concluded that menarche at less than 16 years old increased breast cancer risk, while the genetic variants in miR-196-a-2 might decrease the risk.

Low glucose sensitivity and polymodal chemosensing in neonatal rat adrenomedullary chromaffin cells

Glucose is the primary metabolic fuel in mammalian fetuses, yet mammals are incapable of endogenous glucose production until several hours after birth. Thus, when the maternal supply of glucose ceases at birth there is a transient hypoglycemia that elicits a counterregulatory surge in circulating catecholamines. Because the innervation of adrenomedullary chromaffin cells (AMCs) is immature at birth, we hypothesized that neonatal AMCs act as direct glucosensors, a property that could complement their previously established roles as hypoxia and acid hypercapnia sensors. During perforated-patch, whole cell recordings, low glucose depolarized and/or excited a subpopulation of neonatal AMCs; in addition, aglycemia (0 mM glucose) caused inhibition of outward K+ current, blunted by the simultaneous activation of glibenclamide-sensitive KATP channels. Some cells were excited by each of the three metabolic stimuli, i.e., aglycemia, hypoxia (Po2 ∼30 mmHg), and isohydric hypercapnia (10% CO2; pH = 7.4). Using carbon fiber amperometry, aglycemia and hypoglycemia (3 mM glucose) induced robust catecholamine secretion that was sensitive to nickel (50 μM and 2 mM) and the L-type Ca2+ channel blocker nifedipine (10 μM), suggesting involvement of both T-type and L-type voltage-gated Ca2+ channels. Fura-2 measurements of intracellular Ca2+ ([Ca2+] i) revealed that ∼42% of neonatal AMCs responded to aglycemia with a significant rise in [Ca2+] i. Approximately 40% of these cells responded to hypoxia, whereas ∼25% cells responded to both aglycemia and hypoxia. These data suggest that together with hypoxia and acid hypercapnia, low glucose is another important metabolic stimulus that contributes to the vital asphyxia-induced catecholamine surge from AMCs at birth.

Deficiency in TLR2 but not in TLR4 impairs dendritic cells derived IL-10 responses to schistosome antigens

The purpose of this study was to observe the diverse functions of Toll-like receptors (TLRs) in responses to specific schistosome antigens. Bone marrow-derived dendritic cells (BMDCs) from TLR2-deficient (TLR2(-/-)) or TLR4-deficient (TLR4(-/-)) mice were activated with soluble schistosomule antigen (SSA) or soluble egg antigen (SEA). TLR2 mRNA expression was significantly increased in B6 BMDCs following SEA stimulation. TLR2-deficient BMDCs showed enhanced MHCII expression following SSA and SEA stimulation. TLR2-deficient but not TLR4-deficient BMDC failed to produce IL-12p70 and IL-10 in response to schistosome antigens. TLR2-deficient BMDCs induced a stronger CD4(+) T cell proliferative response. IL-4 and IL-10 expression was inhibited in CD4(+) T cells primed with TLR2-deficient BMDCs, while enhanced in TLR4-deficient BMDCs-primed CD4(+) T cells. These results suggest that TLR2 is essential for the establishment of the DC production of IL-12p70 and IL-10.

Passive synchronization of all-fiber lasers through a common saturable absorber

We present the synchronization of two all-fiber mode-locked lasers, operating at 1.0 μm and 1.54 μm, coupled through the use of a shared single-wall carbon nanotube absorber. Both lasers operate in the soliton-regime, achieving a synchronized repetition rate of 13.08 MHz. The broadband absorption range of the single-wall carbon nanotubes allows the stable mode-locking behavior at 1 μm and 1.5 μm. The nonlinear coupling effects between two energy states of the carbon nanotube absorber result in stable synchronized pulses for hours of operation, with a large cavity mismatch of 1400 μm.

Altered brain activation and connectivity in early Parkinson disease tactile perception

BACKGROUND AND PURPOSE

Deficits in tactile perception are common in patients with PD. However, the neural mechanisms have not been previously reported in the early stages. This study aims to investigate how the brain activity and connectivity changed under tactile perception at early Parkinsonian state by using functional MR imaging.

MATERIALS AND METHODS

Twenty-one patients with early PD and 22 age- and sex-matched controls were recruited and scanned under a passive tactile stimulation task. Within-group and between-group activation maps were acquired, and regions of interest were defined according to the group-comparison result. This was followed by a functional connectivity analysis based on the graph theory.

RESULTS

We found that in the PD group, bilateral sensorimotor cortex was hypoactive during the task, whereas the hyperactive regions were mainly in bilateral prefrontal cortex, bilateral cerebellum, and contralateral striatum. There was a significant decrease of total connectivity degree in ipsilateral SMA in PD, which was negatively correlated with the Unified Parkinson's Disease Rating Scale score. Furthermore, the connection strengths among the areas of prefrontal cortex, striatum, and cerebellum were increased.

CONCLUSIONS

This study illustrated that early PD was associated with not only altered brain activation but also changed functional connectivity in tactile perception. The most significant impairment was in SMA, whereas striato-prefrontal and cerebello-prefrontal loops may play a compensatory role in early PD tactile function.

Translocation of active mitochondria during buffalo (Bubalus bubalis) oocytes in vitro maturation, fertilization and preimplantation embryo development

Mitochondria are energy-supplying organelles, whose distribution and functional integrity are necessary for cell survival and development. In this study, the mitochondrial distribution pattern and activity during buffalo oocyte in vitro maturation, fertilization and preimplantation embryo development were revealed using a fluorescent dye and confocal laser scanning microscopy. Distribution of active mitochondria changed during buffalo oocyte in vitro maturation. Active mitochondria were transferred from the outer to inner and perinuclear cytoplasm as oocytes matured in vitro and aggregated around the pronuclei in the fertilized eggs. Active mitochondria were also observed in preimplantation embryos. In the two-cell stage, they were distributed throughout the cytoplasm. From four-cell to the spherical embryonic stages, active mitochondria translocated to the perinuclear and the periphery of the cytoplasm. These results confirm that mitochondria play an important role in oocyte and embryo. The distribution of active mitochondria might be a marked feature of buffalo oocyte maturation, fertilization and preimplantation embryo development in vitro.

UCP2 -866G/A and Ala55Val, and UCP3 -55C/T polymorphisms in association with type 2 diabetes susceptibility: a meta-analysis study

AIMS/HYPOTHESIS

A meta-analysis was performed to assess the association between the UCP2 -866G/A, UCP2 Ala55Val and UCP3 -55C/T polymorphisms and type 2 diabetes susceptibility.

METHODS

A literature-based search was conducted to identify all relevant studies. The fixed or random effect pooled measure was calculated mainly at the allele level to determine heterogeneity bias among studies. Further analyses were performed that stratified for ethnicity.

RESULTS

We examined 17 publications. Stratified analysis for ethnicity and sensitivity analysis revealed that there was no heterogeneity between studies for these variants. Using an additive model, no significant association of the UCP2 -866G/A polymorphism with type 2 diabetes risk was observed, either in participants of Asian (OR 1.05, 95% CI 0.96, 1.16) or of European (OR 1.03, 95% CI 0.99, 1.07) descent. Neither the UCP2 Ala55Val nor the UCP3 -55C/T polymorphism showed any significant association with type 2 diabetes risk in Europeans (OR 1.04, 95% CI 0.98, 1.09 for Ala55Val; OR 1.04, 95% CI 1.00, 1.09 for -55C/T). In contrast, a statistically significant association was observed for both polymorphisms in participants of Asian descent (OR 1.23, 95% CI 1.12, 1.36 for Ala55Val; OR 1.15, 95% CI 1.03, 1.28 for -55C/T).

CONCLUSIONS/INTERPRETATION

Our meta-analysis suggests that the UCP2 -866G/A polymorphism is unlikely to be associated with increased type 2 diabetes risk in the populations investigated. In contrast, our results indicate that the UCP2 Ala55Val and UCP3 -55C/T polymorphisms may indeed be risk factors for susceptibility to type 2 diabetes in individuals of Asian descent, but not in individuals of European descent. This conclusion warrants confirmation by further studies.

Deletion of Ia-2 and/or Ia-2β in mice decreases insulin secretion by reducing the number of dense core vesicles

AIMS/HYPOTHESIS

Islet antigen 2 (IA-2) and IA-2β are dense core vesicle (DCV) transmembrane proteins and major autoantigens in type 1 diabetes. The present experiments were initiated to test the hypothesis that the knockout of the genes encoding these proteins impairs the secretion of insulin by reducing the number of DCV.

METHODS

Insulin secretion, content and DCV number were evaluated in islets from single knockout (Ia-2 [also known as Ptprn] KO, Ia-2β [also known as Ptprn2] KO) and double knockout (DKO) mice by a variety of techniques including electron and two-photon microscopy, membrane capacitance, Ca(2+) currents, DCV half-life, lysosome number and size and autophagy.

RESULTS

Islets from single and DKO mice all showed a significant decrease in insulin content, insulin secretion and the number and half-life of DCV (p < 0.05 to 0.001). Exocytosis as evaluated by two-photon microscopy, membrane capacitance and Ca(2+) currents supports these findings. Electron microscopy of islets from KO mice revealed a marked increase (p < 0.05 to 0.001) in the number and size of lysosomes and enzymatic studies showed an increase in cathepsin D activity (p < 0.01). LC3 protein, an indicator of autophagy, also was increased in islets of KO compared with wild-type mice (p < 0.05 to 0.01) suggesting that autophagy might be involved in the deletion of DCV.

CONCLUSIONS/INTERPRETATION

We conclude that the decrease in insulin content and secretion, resulting from the deletion of Ia-2 and/or Ia-2β, is due to a decrease in the number of DCV.

Wld(S) protects against peripheral neuropathy and retinopathy in an experimental model of diabetes in mice

AIMS/HYPOTHESIS

We aimed to evaluate the effect of the mutant Wld(S) (slow Wallerian degeneration; also known as Wld) gene in experimental diabetes on early experimental peripheral diabetic neuropathy and diabetic retinopathy.

METHODS

The experiments were performed in four groups of mice: wild-type (WT), streptozotocin (STZ)-induced diabetic WT, C57BL/Wld(S) and STZ-induced diabetic C57BL/Wld(S). In each group, intraperitoneal glucose and insulin tolerance tests were performed; blood glucose, glycated haemoglobin and serum insulin were monitored. These mice were also subjected to the following behavioural tests: grasping test, hot-plate test and von Frey aesthesiometer test. For some animals, sciatic-tibial motor nerve conduction velocity, tail sensory nerve conduction velocity and eye pattern electroretinogram were measured. At the end of the experiments, islets were isolated to detect glucose-stimulated insulin secretion, ATP content and extent of apoptosis. The NAD/NADH ratio in islets and retinas was evaluated. Surviving retinal ganglion cells were estimated by immunohistochemistry.

RESULTS

We found that the Wld(S) gene is expressed in islets and protects beta cells against multiple low doses of STZ by increasing the NAD/NADH ratio, maintaining the ATP concentration, and reducing apoptosis. Consistently, significantly higher insulin concentrations, lower blood glucose concentrations, and better glucose tolerance were observed in Wld(S) mice compared with WT mice after STZ treatment. Furthermore, Wld(S) alleviated abnormal sensory responses, nerve conduction, retina dysfunction and reduction of surviving retinal ganglion cells in STZ-induced diabetic models.

CONCLUSIONS/INTERPRETATION

We provide the first evidence that expression of the Wld(S) gene decreases beta cell destruction and preserves islet function in STZ-induced diabetes, thus revealing a novel protective strategy for diabetic models.