Microbial infection promotes amyloid pathology in a mouse model of Alzheimer's disease via modulating γ-secretase.

Microbial infection as a type of environmental risk factors is considered to be associated with long-term increased risk of dementia, including Alzheimer's disease (AD). AD is characterized by two neuropathologically molecular hallmarks of hyperphosphorylated tau and amyloid-ß (Aß), the latter generated by several biochemically reactive enzymes, including γ-secretase. However, how infectious risk factors contribute to pathological development of the AD core molecules remains to be addressed. In this work, we utilized a modified herpes simplex virus type 1 (mHSV-1) and found that its hippocampal infection locally promotes Aß pathology in 5 × FAD mice, the commonly used amyloid model. Mechanistically, we identified HSV-1 membrane glycoprotein US7 (Envelope gI) that interacts with and modulates γ-secretase and consequently facilitates Aß production. Furthermore, we presented evidence that adenovirus-associated virus-mediated locally hippocampal overexpression of the US7 aggravates Aß pathology in 5 × FAD mice. Collectively, these findings identify a herpesviral factor regulating γ-secretase in the development and progression of AD and represent a causal molecular link between infectious pathogens and neurodegeneration.

The relationship between late (≥ 7 days) systemic dexamethasone and functional network connectivity in very preterm infants.

Background: Current evidence shows that systemic dexamethasone administration starting after the first week of age reduces bronchopulmonary dysplasia for very preterm (VPT) infants, but its neurological effects remain obscure. Using resting-state functional magnetic resonance imaging (rs-fMRI), we assessed the changes in functional network connectivity (FNC) in very preterm infants treated with late systemic dexamethasone (≥7 days of age). Methods: VPT infants (GA ≤ 32 weeks) who needed to rely on mechanical ventilation for more than 7 days but fewer than 14 days to maintain vital signs were included in the study. The cohort was divided into two groups according to whether they were given systemic dexamethasone. In addition, 26 healthy term infants were recruited as controls. At term-equivalent age (TEA), rs-fMRI and 3D-T1 data from eligible infants were acquired with a 3.0-T MRI scanner. After the MRI data were preprocessed, group-level independent component analysis (ICA), a technique used for blind source separation, was used to identify the components of resting-state networks (RSNs). Then, the functional connectivity between components and RSNs was compared among different groups. Upon follow-up at 3 months of corrected age, the neurodevelopmental outcomes of enrolled infants were assessed with the Bayley Scales of Infant Development-Chinese Revision (BSID-CR), and the Motor Development Index (MDI) and Psychomotor Development Index (PDI) were measured. Finally, the correlations between resting-state FNC and BSID scores were analysed. Results: Ultimately, 59 infants were included in the final analysis, including 19 preterm infants who received dexamethasone, 20 who did not, and 20 healthy term infants as controls. Based on their data, 11 components were identified, belonging to 5 RSNs: the visual network (VN), the dorsal attention network (DAN), the auditory network (AN), the primary sensorimotor network (SMN), and the default-mode network (DMN). Compared with the term infants, the preterm infants showed significantly weakened functional connectivity between the DAN and VN, as well as the VN and AN (P < 0.05). Among preterm infants, those who were given dexamethasone showed significantly stronger functional connectivity between the DAN and VN, as well as the DMN and AN (P < 0.05), than those who were not. The correlation analysis demonstrated that the connectivity values between the DAN and VN and between the VN and AN were positively correlated with the MDI (r = 0.432, P＜0.001, and r = 0.479, P＜0.001, respectively) and the PDI (r = 0.436, P＜0.001 and r = 0.516, P＜0.001, respectively). Conclusions: Our investigation uncovers a noteworthy link between the administration of late systemic dexamethasone (≥7 days of age) in VPT infants and distinct improvements in FNC. Furthermore, the observed positive correlation between inter-network connectivity and scores on the BSID-CR implies a plausible neuroprotective aspect of this therapeutic approach in this specific group of children.

Notch signaling pathway involved in Echinococcus granulosus infection regulates dendritic cell development and differentiation.

Introduction: The Notch signaling pathway is involved in the development of many diseases; it regulates the development of dendritic cells (DCs), and affects the immune response of DC-mediated T cells. We previously found that ferritin and malate dehydrogenase (mMDH) in Echinococcus granulosus (E.granulosus) induced different immune responses through sensitized DCs. Therefore, in the study we explored whether the Notch signaling pathway affects the development and differentiation of DCs, causing changes in the immune response of DCs sensitized with E. granulosus antigens, and clarified whether it is involved in E.granulosus infection. Methods: We used the Notch signaling pathway inhibitor [N-[3,5-difluorophenace-tyl] -L-alanyl]-S-phenylglycinet-butyl ester (DAPT) or activator Jagged1 to construct in vitro cell models with blocked or activated Notch signaling respectively. We analyzed the effect of Notch signaling on the development and differentiation of DCs by detecting their morphology, migration function, capacity to promote T cell proliferation, and cytokine secretion. We observed the changes in DC response to E. granulosus antigens and the mediated immune response. Results: DAPT inhibited the development and maturation of DCs, which were in a non-responsive or incompetent state, reduced the sensitization of DCs to Eg.ferritin, weakened the migration ability of DCs, disrupted their ability to mediate T-cell proliferation, reduced DC expression of MHCII, CD80, CD60, and CD40 co-stimulatory molecules, prevented the secretion of cytokines and attenuated the expression of Notch1, Notch2, Notch3 receptors, Jagged1, Delta-like 4 (Delta4), and Hes1. Following Jagged1 addition, the function of DCs was restored to some extent, and the expression of Notch1, Delta4 and Hes1 was activated in response to the stimulation of Eg.ferritin. However, Eg.mMDH stimulated DCs to produce an immune response showing weak interference by DAPT and Jagged1. Discussion: The study suggests that the Notc h signaling pathway is involved in the Eg.ferritin-sensitized DC-mediated immune response, which may become a new target for treating E.granulosus infection.

IL-27 as a potential biomarker for distinguishing between necrotising enterocolitis and highly suspected early-onset food protein-induced enterocolitis syndrome with abdominal gas signs.

BACKGROUND: The initial clinical manifestations and abdominal imaging findings of neonates with necrotising enterocolitis (NEC) and food protein-induced enterocolitis syndrome (FPIES) are sometimes similar; however, their prognosis and therapies are different. We aimed to evaluate the utility of interleukin (IL)-27 as a differentiation marker between NEC and highly suspected early onset (HSEO)-FPIES. METHODS: All samples used in this study were obtained from the neonatal diagnosis centre of Children's Hospital of Chongqing Medical University. In the case-control study, neonates with NEC (n = 13), HSEO-FPIES (n = 9), and jaundice (control, n = 8) were enroled to determine the serum IL-27 levels using commercial enzyme-linked immunosorbent assay (ELISA) kits. In the validation cohort study, the NEC (n = 87), HSEO-FPIES (n = 62), and jaundice (control, n = 54) groups were included to analyse the diagnostic efficiency of IL-27 for discriminating between NEC and HSEO-FPIES using a receiver operating characteristic (ROC) curve. FINDINGS: In the case-control study, IL-27 levels were higher in the NEC group than in the HSEO-FPIES group (p = 0·005). In the cohort study, the area under the ROC curve (AUC) of IL-27 for differentiating NEC from HSEO-FPIES was 0·878, which was higher than the AUCs of IL-6 (0·761), C-reactive protein (0·800), white blood cell count (0·637), neutrophils (0·765), lymphocytes (0·782), neutrophil to lymphocyte ratio (0·781), and platelet count (0·729). INTERPRETATION: Serum IL-27 is a novel biomarker that may potentially discriminate NEC from HSEO-FPIES in neonates. FUNDING: None.

Isolation, Purification, and Identification of Taxol and Related Taxanes from Taxol-Producing Fungus Aspergillus niger subsp. taxi.

The content of taxol in the bark of yews is very low, and this is not affordable from the environmental point of view. Thus, it is a necessity to look for alternative sources of taxol production to solve its supply. Currently, a large portion of the taxol in the market comes from chemical semi-synthesis, but the semi-synthetic precursors such as baccatin III and 10-deacetyl-baccatin III are extracted from needles and twigs of yew trees. Taxol-producing fungi as a renewable resource is a very promising way to increase the scale of taxol production. Our group has obtained a taxol-producing endophytic fungus, Aspergillus niger subsp. taxi HD86-9, to examine if A. niger can produce the taxanes. Six compounds from the fermentation broth of strain HD86-9 were isolated and identified by 1H NMR, 13C NMR, and ESI-MS. The results showed that the six compounds included four taxane diterpenoids (taxol, cephalomannine, baccatin III, and 10-deacetyl-baccatin III) and two non-taxane compounds (ß-sitosterol and flavonoid isovitexin). The study verified that the taxanes can be produced by the A. niger, which is very important to taxol production via chemical semi-synthesis. Additionally, the finding is potentially very significant to solve the taxol semi-synthetic precursors extracted from needles and twigs of yew trees, and the precursor production can be easily increased through the culture condition optimization, genetic breeding, and metabolic engineering of the A. niger.

Genistein inhibits hypoxia, ischemic-induced death, and apoptosis in PC12 cells.

A hypoxia/ischemia neuronal model was established in PC12 cells using oxygen-glucose deprivation (OGD). OGD-induced neuronal death, apoptosis, glutamate receptor subunit GluR2 expression, and potassium channel currents were evaluated in the present study to determine the effects of genistein in mediating the neuronal death and apoptosis induced by hypoxia and ischemia, as well as its underlying mechanism. OGD exposure reduced the cell viability, increased apoptosis, decreased the GluR2 expression, and decreased the voltage-activated potassium currents. Genistein partially reversed the effects induced by OGD. Therefore, genistein may prevent hypoxia/ischemic-induced neuronal apoptosis that is mediated by alterations in GluR2 expression and voltage-activated potassium currents.

Stat3 Controls Maturation and Terminal Differentiation in Mouse Hippocampal Neurons.

The hippocampus is an important region in the brain, responsible for learning, memory, and emotion. The hippocampus is composed of abundant neuronal cells, of which maturation is critical to physiological function and neural disease occurrence. Although the factors affecting neuronal maturation in the hippocampus has been widely studied, the specific mechanism involved in this process is still elusive to us. In the current study, Stat3 silencing and overexpression was achieved through lentivirus and adenovirus system. We found that hippocampal neuronal maturation was enhanced when Stat3 was downregulated. By contrast, formation of neurosphreres was observed in hippocampal cultures due to the overexpression of Stat3. In addition, these neuropheres had the capacity to differentiate into different cell subtypes, indicating the acquisition of multipotency when Stat3 was overexpressed in hippocampal cells. These processes were correlated with MAPK signaling, indicating the potential linkage among Stat3 expression, MAPK activation, and neuronal maturation. Above all, this study demonstrated the role of Stat3 in hippocampal neuronal maturation and differentiation. Also, the molecular mechanism was explored through the MAPK signal manipulation.

Biodegradable Polymeric Nanoparticles as the Delivery Carrier for Drug.

BACKGROUND: Drug research and development has entered into the new epoch of innovation formulation, and the drug delivery system has been in the forefront of pharmaceutical innovation. Nanotechnology is widely used in fiber and textiles, electronics, space, agriculture, forensic science and medical therapeutics. It increasingly plays a significant role in drug delivery system. Compared with traditional delivery system, the nanoparticle drug delivery system has lots of merits, such as the high drug loading ability, the excellent biocompatibility, low toxicity, controlled and targeted drug release. METHODS: We undertook a structured research of biodegradable polymeric nanoparticles used as delivery carrier for drug using a focused review question and inclusion/exclusion criteria. We have searched the bibliographic databases for peerreviewed research literature. The outstanding characteristics of the screened papers were described respectively, and a systematic content analysis methodology was used to analysis the findings. RESULTS: Seventy-three papers were included in the review, the majority defined leadership and governance approaches that had impacted upon the polymeric nanoparticles as the delivery carrier for drug in therapeutic applications and developments. Seven papers outlined the superiority characteristics of polymeric nanoparticles that applied in the field of vaccine. Forty-seven papers overviewed the application prospects of polymeric nanoparticles used as drug delivery carrier for cancer. These included current advances in research and clinical applications of polymeric nanoparticles. The review identified the drug delivery carrier of biodegradable polymeric nanoparticles, and we described the synthesis methods, applications and challenges of polymeric nanoparticles. CONCLUSION: The findings of this review identified that the biodegradable polymeric nanoparticles were used as delivery carrier for drug currently. It also indicates that the biodegradable polymeric nanoparticles play an important role in the drug delivery.

Oxygen-glucose deprivation enhancement of cell death/apoptosis in PC12 cells and hippocampal neurons correlates with changes in neuronal excitatory amino acid neurotransmitter signaling and potassium currents.

Neuronal death is a pathophysiological process that is often caused by hypoxia/ischemia. However, the causes of hypoxia/ischemia-induced neuronal death are debated, and additional experimental data are needed to resolve this debate. In the present study, we applied oxygen-glucose deprivation (OGD) to PC12 cells and hippocampal neurons to establish a hypoxia/ischemia model. We evaluated the effects of OGD on cell death/apoptosis and on the levels of two excitatory amino acid neurotransmitters, aspartic acid and glutamic acid, in both hippocampal neurons and the medium used to culture the hippocampal neurons. We also evaluated GluR2 expression in hippocampal neurons as well as the effects of OGD on whole-cell potassium currents in PC12 cells and hippocampal neurons. Our experimental results showed that OGD significantly decreased cell viability and markedly enhanced apoptosis in PC12 cells and hippocampal neurons. OGD treatment for 3 h increased the levels of Asp and Glu in the medium used to culture hippocampal neurons, but decreased both the levels of Asp and Glu and GluR2 expression in hippocampal neurons. Furthermore, OGD altered the electrophysiological properties of voltage-dependent potassium channels in PC12 cells and hippocampal neurons in different ways; OGD decreased the voltage-dependent potassium current in PC12 cells, but increased this current in hippocampal neurons. On the basis of these results, we concluded that OGD enhanced neuronal cell death/apoptosis in addition to altering neuronal excitatory amino acid neurotransmitter signaling and whole-cell voltage-dependent potassium currents.

[Advances and prospects of taxol biosynthesis by endophytic fungi].

Taxol is one of the most important chemotherapeutic drugs against cancer. Taxol has been mainly extracted from the bark of yews for a long time. However, methods for the extraction of taxol from the bark of Taxus species were inefficient and environmentally costly. As a result of the high ecological toll exacted on trees with the potential for Pacific yew extinction, investigators began to look for other methods of taxol production. Recently, increasing efforts have been made to develop alternative means of taxol production, such as using complete chemical synthesis, semi-synthesis, Taxus spp. plant cell culture and microbe fermentation. Using microbe fermentation in the production of taxol would be a very prospective method for obtaining a large amount of taxol. Therefore, it is necessary to understand the molecular basis and genetic regulation mechanisms of taxol biosynthesis by endophytic fungi, which may be helpful to construct the genetic engineering strain with high taxol output. In this paper, the taxol biosynthesis pathway from Taxus cells and the advantages of taxol biosynthesis by endophytic fungi were discussed. The study on the isolation and biodiversity of taxol-producing endophytic fungi and the taxol biosynthesis related genes are also discussed.

MiR-495 is a Predictive Biomarker that Downregulates GFI1 Expression in Medulloblastoma.

BACKGROUND: Alterations in the expression level of miR-495 were recently observed in various tumours. Medulloblastoma is the most common malignant brain tumour in children. However, the clinical significance of miR-495 in medulloblastomas remains unclear. METHODS: The expression levels of miR-495 was examined in 62 archival formalin-fixed paraffin-embedded (FFPE) medulloblastoma specimens using TaqMan Real-time Quantitative PCR arrays. Immunohistochemistry was used to determine the expression of Gfi1 in medulloblastoma tissues, and a luciferase reporter assay was carried out to confirm whether Gfi1 is a direct target of miR-495. RESULTS: MiR-495 expression is repressed in medulloblastoma samples compared with normal cerebellum tissues. Furthermore, patients with a low level of miR- 495 showed significantly poorer survival, as determined by the log-rank test (P = 0.033). The multivariate analysis results showed that the miR-495 expression levels were an independent predictor of overall survival in medulloblastoma patients (P = 0.027; hazard ratio = 0.267). Our study provides the first demonstration that miR-495 directly interacts with the Gfi1 3'UTR to regulate Gfi1 at a post-transcriptional level and that the expression level of miR-495 is inversely correlated with the Gfi1 protein level in medulloblastoma specimens. CONCLUSION: Our results suggest that miR-495 may be a prognostic predictor in medulloblastoma and that Gfi1 is a potential functional target of miR-495.

Effect of bone marrow stromal cell transplantation on neurologic function and expression of VEGF in rats with focal cerebral ischemia.

There is evidence that the transplantation of mesenchymal stem cells into rat models of cerebral ischemia reduces ischemic damage; however, the mechanism remains to be elucidated. The present study aimed to assess the effect of transplantation of human bone marrow stromal cells (hBMSCs) on neurologic function and the expression of vascular endothelial growth factor (VEGF) in a rat model of focal cerebral ischemia. The left middle cerebral artery of adult Wistar rats was occluded for 90 min using a nylon thread, followed by reperfusion for 1 h. hBMSCs labeled with 5-bromo-2-deoxyuridine (BrdU) were stereotaxically injected into the ischemic boundary zone. Behavioral analysis using the Neurological Severity Score (NSS) was conducted on days 1, 3, 7 and 28, and a histologic evaluation was performed simultaneously. VEGF was detected by immunofluorescence staining and western blot analysis. Fifty rats were divided equally into five groups: Normal control, sham­operated, operated (no transplantation), Dulbecco's medium Eagle's medium (DMEM)-injected (received only serum-free DMEM), and hBMSC-transplanted. The hBMSC-transplanted group showed significantly improved behavioral recovery compared with the operated and DMEM-transplanted groups on days 3, 7 and 28. Histological examination showed that transplanted cells migrated from the injection site into nearby areas including the cortex. Expression of VEGF was significantly greater in the hBMSC group compared with the other four groups on each assessment day. The expression of VEGF was found to be beneficial for functional recovery following cerebral ischemic injury and hBMSC transplantation stimulated the expression of VEGF. Transplantation of BMSCs may be a promising therapeutic strategy for treating cerebral infarction.

Genetic association of osteopontin (OPN) and its receptor CD44 genes with susceptibility to Chinese gastric cancer patients.

PURPOSE: (1) To investigate associations between single nucleotide polymorphisms (SNPs) in osteopontin (OPN) and its receptor-cluster of differentiation 44 (CD44) genes and gastric cancer susceptibility. (2) To explore the correlation of OPN and CD44 expression of gastric cancer. METHODS: We detected 26 SNPs of the genes in gastric cancer patients from the Chinese Han population by Sequenom technique and performed expression of OPN in combination with CD44 in 243 tissues samples of the cases by tissue microarray and immunohistochemistry (IHC). RESULTS: We found that the minor alleles of OPN rs4754C>T and OPN rs9138C>A remained strongly associated with decreased gastric cancer risk (P = 1.53 × 10(-4), odds ratio (OR) 0.642, 95 % confidence interval (CI) 0.511-0.808 and P = 1.59 × 10(-4), OR 0.642, 95 %CI 0.510-0.809). OPN variant rs1126772A>G and CD44 variant rs353639A>C significantly contributed to elevated risk of gastric cancer (P = 0.042, OR 1.279, 95 % CI 1.008-1.622 and P = 0.047, OR 1.334, 95 % CI 1.003-1.772). Haplotypes of OPN and CD44 variants significantly influenced risk of gastric cancer. Clinical data indicated that rs4754 and rs9138 of OPN were significantly associated with smoking (P = 0.029, OR 0.343, 95 % CI 0.127-0.926 and P = 0.029, OR 0.343, 95 %CI 0.127-0.926) and OPN rs1126772 revealed associations with tumor-node-metastasis (TNM) stage (P = 0.025, OR 1.765, 95 % CI 1.073-2.905) and tumor differentiation (P = 0.031, OR 1.722, 95 % CI 1.049-2.825). OPN expression was observed in 133 of the 243 cases (54.7 %) by IHC and was correlated with serosa invasion (P = 0.013), TNM stage (P = 0.003) and lymph node metastasis (P = 0.002). CD44 expression was found in 92 of the 243 cases (37.9 %) and was associated with tumor size (P = 0.005) and lymph node metastasis (P = 0.023), respectively. The OPN expression displayed a positive association with CD44 (P = 0.01, r s = 0.164). CONCLUSIONS: We found that the polymorphisms rs4754, rs9138 and rs1126772 of OPN gene and rs353639 of CD44 gene were significantly associated with gastric cancer. Our IHC data indicated that interaction of OPN and CD44 protein would promote progression and metastasis of gastric cancer.

Association analysis of ERBB2 amplicon genetic polymorphisms and STARD3 expression with risk of gastric cancer in the Chinese population.

The purpose of this study was to investigate whether risk of gastric cancer (GC) was associated with single nucleotide polymorphisms (SNPs) in a gene cluster on the chromosome 17q12-q21 (ERBB2 amplicon) in the Chinese Han population. We detected twenty-six SNPs in this gene cluster containing steroidogenic acute regulatory-related lipid transfer domain containing 3 (STARD3), protein phosphatase 1 regulatory subunit 1B (PPP1R1B/DARPP32), titin-cap (TCAP), per1-like domain containing 1(PERLD1/CAB2), human epidermal growth factor receptor-2 (ERBB2/HER2), zinc-finger protein subfamily 1A 3 (ZNFN1A3/IKZF3) and DNA topoisomerase 2-alpha (TOP2A) genes in 311 patients with GC and in 425 controls by Sequenom. We found no associations between genetic variations and GC risk. However, haplotype analysis implied that the haplotype CCCT of STARD3 (rs9972882, rs881844, rs11869286 and rs1877031) conferred a protective effect on the susceptibility to GC (P=0.043, odds ratio [OR]=0.805, 95% confidence intervals [95% CI]=0.643-0.992). The STARD3 rs1877031 TC genotype endued histogenesis of gastric mucinous adenocarcinoma and signet-ring cell carcinoma (P=0.021, OR=2.882, 95% CI=1.173-7.084). We examined the expression of STARD3 in 243 tumor tissues out of the 311 GC patients and 20 adjacent normal gastric tissues using immumohistochemical (IHC) analysis and tissue microarrays (TMA). The expression of STARD3 was observed in the gastric parietal cells and in gastric tumor tissues and significantly correlated with gender (P=0.004), alcohol drinking (P<0.001), tumor location (P=0.007), histological type (P=0.005) and differentiation (P=0.023) in GC. We concluded that the combined effect of haplotype CCCT of STARD3 might affect GC susceptibility. STARD3 expression might be related to the tumorigenesis of GC in the Chinese population.

Genetic analysis of ADIPOQ variants and gastric cancer risk: a hospital-based case-control study in China.

Single-nucleotide polymorphisms (SNPs) of adiponectin (ADIPOQ), adiponectin receptor 1 (ADIPOR1) and ADIPOR2 genes contribute to the risk and progression of cancers. Here, we investigated the associations between variants of these three genes and the risk of gastric cancer. We genotyped six ADIPOQ SNPs, nine ADIPOR1 SNPs and six ADIPOR2 SNPs using the Sequenom technique in a hospital-based case-control study of patients with gastric cancer and cancer-free controls in the Chinese Han population. We found associations of certain variants with location of gastric cancer. Rs16861205 with the minor allele A in ADIPOQ, rs10773989 with the minor allele C and rs1044471 with the minor allele T in ADIPOR2 presented significant associations with a decreased risk of cardia cancer (P = 0.024, OR 0.605, 95 % CI 0.390-0.938; P = 0.015, OR 0.699, 95 % CI 0.522-0.935; and P = 0.022, OR = 0.703, 95 % CI 0.519-0.951, respectively). ADIPOQ rs16861205 with minor allele A displayed an association with an increased risk of body cancer (P = 0.010, OR 1.821, 95 % CI 1.148-2.890). Further stratified analysis of the patients indicated that there were significant correlations for rs1342387A/G (P = 0.027) and rs16861205A/G (P = 0.000) with tumor location; rs16850799A/G (P = 0.004) and rs2058033C/A (P = 0.003) with invasion depth; rs16850799A/G (P = 0.019) with the tumor-node-metastasis stage; rs16850799A/G (P = 0.016), rs1501299A/C (P = 0.005) and rs1063538C/T (P = 0.017) with alcohol consumption; rs11612414A/G (P = 0.040) and rs12733285T/C (P = 0.005) with salted food; rs1063538C/T (P = 0.043) with family history of gastric cancer; and rs11612414A/G (P = 0.029) with gender. Adiponectin expression significantly correlated with gender (P = 0.014), alcohol consumption (P = 0.037), family history (P = 0.019) and invasion depth of primary tumor (P = 0.024). Our data suggested that variants of ADIPOQ may be genetic markers conferring susceptibility to gastric cancer subtypes. These findings need to be validated in a larger panel of samples from distinct populations.

Human mesenchymal stem cells increases expression of α-tubulin and angiopoietin 1 and 2 in focal cerebral ischemia and reperfusion.

Angiogenesis is associated with improved neurologic recovery after cerebral ischemia. Human bone marrow mesenchymal stem cells (hMSCs) have been successfully used to treat ischemic stroke and were shown to induce the expression of a number of neurotrophic factors including VEGF, epidermal growth factor (EGF) and basic fibroblast growth factor (bFGF) in a rat middle cerebral artery occlusion (MCAO) ischemia model. In this study, we aimed to understand the mechanism underlying the improvement of neurological function following hMSCs transplantation into MCAO rats. We established a rat MCAO model and used immunofluorescence to evaluate α-tubulin expression in the hippocampus. We used RT-PCR to determine the expression of Ang-1 and Ang-2 mRNAs after transplantation of hMSCs into MCAO rats. We showed a significant decrease in α-tubulin expression in rats with cerebral ischemia, suggesting that α-tubulin is a protective protein in cerebral ischemia Transplantation of hMSCs significantly upregulated α-tubulin levels in the hippocampus. Transplantation of hMSCs also resulted in a significant upregulation of Ang-1 and Ang-2 mRNAs in MCAO rats. Ang-2 expression was upregulated earlier than Ang-1, suggesting that (1) transplantation of hMSCs promotes angiogenesis and that (2) Ang-2 may be an initiator of angiogenesis. Our results provide a theoretical basis for the therapeutic use of hMSCs in cerebral ischemia.

Association of the variant rs2243421 of human DOC-2/DAB2 interactive protein gene (hDAB2IP) with gastric cancer in the Chinese Han population.

Human DOC-2/DAB2 interactive protein (hDAB2IP) gene is a novel member of the Ras GTPase-activating family and has been demonstrated to be a tumor-suppressor gene that inhibits cell survival and proliferation and induces cell apoptosis. It was reported that the expression level of hDAB2IP in gastric cancer tissue was highly correlated with tumor progression, however, whether hDAB2IP genetic variants are associated with the risk of gastric cancer remains yet unknown. In this case-control study, we conducted a genetic analysis for hDAB2IP variants in 311 patients with gastric cancer and 425 controls from the Chinese Han population. We found that the SNP rs2243421 of hDAB2IP gene with the minor allele C significantly revealed strong association with decreased gastric cancer susceptibility (P=0.007, adjusted odds ratio [OR]=0.734, 95%CI=0.586-0.919). Haplotypes rs2243421 and rs10985332 (HaploType: CC, P=0.012, aOR=0.760) and haplotypes rs2243421 and rs555996 (HaploType: CG, P=0.034, aOR=0.788) represented the decreased risk of gastric cancer, respectively. On the contrary, rs2243421 and rs555996 showed an elevated susceptibility (HaploType: TG, P=0.010, aOR=1.320). Our results for the first time provided new insight into susceptibility factors of hDAB2IP gene variants in carcinogenesis of gastric cancer.

Development of a protein biochip to identify 6 monoclonal antibodies against subtypes of recombinant human interferons.

Recombinant human interferons (rhIFNs) are broadly used as effective therapeutic agents with antiviral, antitumor, and immune-modulating properties. Advances in protein biochip technology have benefited the medical community greatly, making true parallelism, miniaturization, and high throughput possible. In this study, 5 rhIFN proteins (IFN-alpha1b, IFN-alpha2a, IFN-alpha2b, IFN-beta, and IFN-gamma) were immobilized onto an N-hydroxysuccinimide (NHS)-modified gold-based biochip. The protein biochip was incubated with 6 specific mouse IgG antibodies (AK1, AK2, AK3, AK4, BK1, and CK1) against the human IFNs and then with Cy3-conjugated goat anti-mouse IgG antibody. The results showed that monoclonal antibody AK1 presented a unique binding characteristic to IFN-alpha1b. AK2 reacted in immunoassays equally with IFN-alpha2a and IFN-alpha2b. AK3 detected IFN-alpha1b, IFN-alpha2a, and IFN-alpha2b. AK4 had positive immunological responses directed to both IFN-alpha1b and IFN-alpha2b. Monoclonal antibodies BK1 and CK1 recognized epitope of IFN-beta and IFN-gamma, specifically. The assay specificity of the biochip was further confirmed by enzyme-linked immunosorbent assay (ELISA) and western blotting. Finally, 88 serum samples from patients treated with rhIFN-alpha2b were simultaneously tested on a single biochip. The result demonstrated that 6.8% (6 of 88 cases) presented positive reactions to anti-IFN-alpha2b antibodies, indicating that the patients under rhIFN-alpha2b therapy produced neutralized antibody against the IFN. The biochip format would offer a competitive alternative tool not only for facilitating characterization of IFN subtypes but also potentially for enabling clinical serum detection of corresponding antibodies directed against IFNs.

Role of ATP in trauma-associated cytokine release and apoptosis by P2X7 ion channel stimulation.

Trauma causes immediate cytokine release and the systemic inflammatory response syndrome (SIRS), often preceding sepsis and septic shock. Mechanisms may involve P2X7 ion channel activation via adenosine 5'-triphosphate (ATP) released from surrounding tissue and platelets. A number of single nucleotide polymorphisms (SNPs) influence the nature and magnitude of P2X7-stimulated cytokine release and apoptosis. In whole blood and isolated mononuclear blood cells (PBMCs) of donors with wild-type and heterozygous mutated genotypes, we found downregulated IL-8 and caspase-3 activation but no reproducible effect on tumor necrosis factor (TNF)-alpha and IL-1beta release. IL-8 and caspase-3 activation were both influenced by paxilline, an inhibitor of calcium-activated potassium channels. Confocal laser scanning microscopy demonstrated that calcium signaling is affected by paxilline as well. We propose that blockade of potassium channels may be relevant to attenuate ATP-induced cytokine responses and apoptosis. The presence of functional SNPs in heterozygous genotypes appears to play a role.

Biochip as a potential platform of serological interferon alpha2b antibody assay.

The formation of antibodies against cytokines may play a major role in the generation of the immune response and may affect treatment protocols with recombinant cytokines. Interferon (IFN) is one of the effective therapeutic agents with anti-viral and anti-tumor specific effects. The appearance of IFN antibodies in patients may limit the natural and the therapeutic effect by IFNs. In contrast to conventional ELISA techniques, we here report a simple biochip methodology that enables identification of antibodies against cytokines and peptides. The method takes advantage of a functionalized self-assembled monolayer modified by N-hydroxysuccinimide (NHS). To validate this surface, four human proteins: IFNalpha2b, leptin, growth hormone and human IgG, with molecular sizes ranging between 14 and 150 kDa, were used. A number of other parameters for protein assay conditions by array technology were evaluated concomitantly. Finally, 56 serum samples from patients treated with recombinant human IFNalpha2b were simultaneously tested on single chip. In these patients, 16.1% (9 of 56 cases) were positive for IFNalpha2b antibodies. All results were confirmed in an ELISA, specific for the identification of IFNalpha specific antibodies in human samples. The potential application of this protein biochip can be amplified rapidly and reliably to test not only IFNalpha2b, but also other cytokine specific antibodies. The clinical relevance of such assays for investigations in autoimmune disorders is expected.