HMGB1-Induced p62 Overexpression Promotes Snail-Mediated Epithelial-Mesenchymal Transition in Glioblastoma Cells via the Degradation of GSK-3β

Rationale: Glioblastoma (GBM) is the most common and aggressive brain tumor, characterized by its propensity to invade the surrounding brain parenchyma. The effect of extracellular high-mobility group box 1 (HMGB1) protein on glioblastoma (GBM) progression is still controversial. p62 is overexpressed in glioma cells, and has been associated with the malignant features and poor prognosis of GBM patients. Hence, this study aimed to clarify the role of p62 in HMGB1-induced epithelial-mesenchymal transition (EMT) of GBM both in vitro and in vivo.

Methods: Immunoblotting, immunofluorescence and qRT-PCR were performed to evaluate EMT progression in both human GBM cell line and primary GBM cells. Transwell and wound healing assays were used to assess the invasion and migration of GBM cells. shRNA technique was used to investigate the role of p62 in HMGB1-induced EMT both in vitro and in vivo orthotopic tumor model. Co-immunoprecipitation assay was used to reveal the interaction between p62 and GSK-3β (glycogen synthase kinase 3 beta). Immunohistochemistry was performed to detect the expression levels of proteins in human GBM tissues.

Results: In this study, GBM cells treated with recombinant human HMGB1 (rhHMGB1) underwent spontaneous EMT through GSK-3β/Snail signaling pathway. In addition, our study revealed that rhHMGB1-induced EMT of GBM cells was accompanied by p62 overexpression, which was mediated by the activation of TLR4-p38-Nrf2 signaling pathway. Moreover, the results demonstrated that p62 knockdown impaired rhHMGB1-induced EMT both in vitro and in vivo. Subsequent mechanistic investigations showed that p62 served as a shuttling factor for the interaction of GSK-3β with proteasome, and ultimately activated GSK-3β/Snail signaling pathway by augmenting the degradation of GSK-3β. Furthermore, immunohistochemistry analysis revealed a significant inverse correlation between p62 and GSK-3β, and a combination of the both might serve as a more powerful predictor of poor survival in GBM patients.

Conclusions: This study suggests that p62 is an effector for HMGB1-induced EMT, and may represent a novel therapeutic target in GBM.

Estimation on Formation Time of Thrombus

OBJECTIVES

To observe the changes of the formation time of venous thrombus in rats, and to provide new ideas and methods for the estimation on thrombus formation time of the forensic cases died from thrombosis.

METHODS

Totally 80 rats were randomly divided into 10 groups （0 h, 3 h, 6 h, 12 h, 1 d, 3 d, 1 week, 2 weeks, 3 weeks and 4 weeks after operation）. A vein thrombosis model was established by the "narrow" method. The processes of thrombosis, organization, recanalization and the features of change on hemosiderin and calcium salt were observed by HE stain, Perls stain and Von Kossa stain. The expression changes of CD61, α-SMA and CD34 were observed by immunohistochemical staining technique.

RESULTS

Platelets adhered to the exposed blood vessel intima 3 h after operation, and platelet trabeculae were formed by the repeated accumulation of platelets 1 d after operation. The thrombus organization formed through the fibroblasts from vessel wall that grew into the interior of the thrombus 3 d after operation. Endothelial cells covered the surface of thrombus and then the new blood vessels were reformed, and the vessels were reconstructed. The expression of CD61 upregulated at the stages of the thrombus formation （3 h） and thrombus reformation （4 weeks）, and reached the peak 1 d after thrombus formation. The release of hemosiderin and the initial expression of α-SMA were detected 3 d later. Calcium deposit and expression of CD34 were observed 1 week later.

CONCLUSIONS

The hemosiderin, calcium salt, CD61, α-SMA and CD34 show time-dependent changing characteristics, which is expected to provide a reference for the estimation on thrombus formation time of the forensic cases died from thrombosis.

Hemagglutinin-Neuraminidase and fusion genes are determinants of NDV thermostability

Newcastle disease (ND) caused by infections with virulent strains of Newcastle disease virus (NDV) continues to be a threat for poultry industry worldwide. The prospect of developing a thermostable and effective NDV vaccine is still highly desirable. To investigate the determinants of thermostability in NDV, we generated recombinant NDV strains by exchanging viral hemagglutinin-neuraminidase (HN) gene or by mutating the fusion (F) gene. The results showed that the HN and F protein were both determinants of NDV thermostability. With increased thermostability, the HN protein-chimeric virus showed significantly reduced neuraminidase and hemadsorption activities, but its hemolytic activity was retained. We also found that changing the amino acid in the F protein cleavage sites, affected the thermostability as well as the pathogenicity and fusogenic capacity of the virus. Taken together, our results suggest that HN and F proteins both contribute to the thermostability of NDV, and other viral biological activities change as the thermostability of the virus changes. These findings should be of benefit to the development of a thermostable and efficacious NDV vaccine.

[Effect and significance of mild hypothermia on cerebral blood flow velocity and cerebral extraction rate of oxygen in patients with severe subarachnoid hemorrhage]

Objective: Through studying the variations of cerebral blood flow velocity and cerebral extraction rate of oxygen to investigate the effect and mechanism of mild hypothermia therapy on early brain injury (EBI) and cerebral vasospasm (CVS) induced by sever subarachnoid hemorrhage (SAH). Methods: A total of 62 adult patients admitted in the Department of Neurosurgery of Tianjin TEDA Hospital from January 2014 to December 2016 with severe SAH without contraindications of hypothermia therapy were randomly divided into mild hypothermia (MH) group of 30 cases and routine treatment (RT) group of 32 cases.The general data were no significant difference.The routine treatment group got bloody cerebrospinal fluid drainage, spasmolysis, 3H treatment, etc.Besides conventional treatment, MH group got mild hypothermia therapy started on the day of admission within 2-8 hours, lower rectal temperature and maintained at (35±1) ℃, maintain 5-7 d. The mean velocity of middle cerebral artery blood flow (VmMCA) and Lindergaard index of two groups were detected by transcranial Doppler to indirectly evaluate the degree and evolution of CVS.Blood gas analysis was performed to obtain the blood oxygen content of the artery and jugular vein (CaO(2)/CjvO(2)) in the two groups at the same time, and the cerebral extraction rate of oxygen (CERO(2)) = (CaO(2)-CjvO(2))/CaO(2) was calculated. Results: Within 5 times of admission d1, d2, d3, d7 and d14, mean results of VmMCA of RT group were significantly higher than those of the MH group at d2, d3, d7 and d14 on statistics.The changes of CERO(2) between MH group and RT group during the observation period were compared at the same time: there was no significant difference between d1 and d14 (P>0.05); at d2, d3 and d7 showed marked differences, and that of the MH group was significantly lower than that of the RT group' (P<0.01). The correlation analysis showed that it had a weak correlation between CERO(2) and VmMCA (P>0.05) in the MH group, and CERO(2) was significantly positively correlated with VmMCA in the RT group (P<0.01). Conclusion: MH therapy has a positive significance to reduce the incidence, degree and the duration of CVS.The relationship between CVS and the degree of hypoxia in brain was broken by the MH therapy to reduce the adverse effects of EBI through reducing metabolism, thereby alleviating hypoxia damage in brain tissue.Setting the appropriate target temperature and the course of treatment and then the gentle rewarming process can reduce the incidence of complications of hypothermia therapy.

A subunit vaccine based on fiber-2 protein provides full protection against fowl adenovirus serotype 4 and induces quicker and stronger immune responses than an inactivated oil-emulsion vaccine

As the number of hepatitis hydropericardium syndrome (HHS) cases has increased in recent years in China, development of a safe and effective vaccine is now urgent. To address this problem a subunit vaccine is a good option, we here systematically investigated the minimum immune dose of a subunit vaccine against HHS based on recombinant fowl adenovirus serotype 4 (FAdV-4) fiber-2 protein and compared the effects between this subunit vaccine and an inactivated oil-emulsion FAdV-4 vaccine in a vaccination trial. The results revealed that the lowest dose of recombinant fiber-2 protein that could provide 100% protection against challenge with virulent FAdV-4 strain HB1501 as well as elicit protective immunity was 2.5 μg/bird. Neither clinical signs nor gross lesions were observed in chickens. In addition, immunization of specific-pathogen-free (SPF) chickens with recombinant fiber-2 protein (≥2.5 μg/bird) could induce quicker and stronger immune responses than the inactivated oil-emulsion FAdV-4 vaccine. These findings provide important information about the development of subunit vaccines for the control of HHS.

Attenuation, safety, and efficacy of a QX-like infectious bronchitis virus serotype vaccine

Avian infectious bronchitis (IB) is a highly contagious disease caused by avian infectious bronchitis virus (IBV), which is a considerable economic threat to the poultry industry. QX-like IBV strains have increasingly emerged in China in recent years. Hence, development of a specific vaccine to guard against their potential threat is important. In this study, we sought to develop an attenuated vaccine strain. First, attenuated QX-like IBV strain SZ130 was created by continuous passage in chicken embryos for 130 generations, and then its safety was tested. We also evaluated the protective efficacy of different doses of SZ130 against challenge with QX-like IBV field strain SD in chickens. SZ130-infected birds did not experience IB-like signs and organ lesions. Additionally, an excellent protective effect of SZ130 vaccination was observed when vaccinated birds were challenged with SD, with no clinical signs or gross lesions, decreased target tissue replication rates, and lower ciliostasis scores in all immunized groups. These findings indicate that attenuated IBV strain SZ130 is highly safe in chicks and may serve as an effective vaccine against the threat posed by QX-like IBV strains.

The glutamic residue at position 402 in the C-terminus of Newcastle disease virus nucleoprotein is critical for the virus

The nucleocapsid proteins (NPs) of Newcastle disease virus (NDV) and other paramyxoviruses play an important functional role during genomic RNA replication. Our previous study showed that the NP-encoding gene significantly influenced viral replication. Here, we investigated the roles of certain amino acid residues in the NP C-terminus in viral replication and virulence. Results showed that the glutamic acid residue at position 402 (E402) in the C-terminus of the NP is critical for RNA synthesis in the NDV mini-genome system. Mutation of E402 resulted in larger viral plaques that appeared more quickly, and increased the virulence of NDV. Further study indicated that the mutant virus had increased RNA levels during the early stages of virus infection, but that RNA replication was inhibited at later time points. These findings increase our knowledge of viral replication and contribute to a more comprehensive understanding of the virulence factors associated with NDV.

Dynamaic changes of proliferation and apoptosis in rat retina development

Precise coordination of cell proliferation and apoptosis is essential for proper organ morphogenesis and function during mammalian development. The retina is a part of the central nervous system, with a function in capture and conversion of light particles into nerve signals. However, the dynamical changes of cell proliferation and apoptosis during the retinal development is unclear. Thus, this study was to observe the changes of proliferating cell nuclear antigen expression and apoptosis during the retina development in rats. Rats from different developmental stages (embryonic days 14-20 (E14-20), postnatal days 0-15 (P0-15) and adult (P36)) were used. The eyeballs were removed and fixed immediately in formalin. The tissues were embedded in paraffin. Sections were prepared for immunohistochemical staining and terminal deoxynucleotidyl transferase-mediated dUTP nick end labeling (TUNEL). PCNA expression appeared in large quantities in rat retina from E14 to P7, decreased obviously since P9, and could not be observed since P15. Apoptotic cells appeared in small quantities since E18. And then apoptotic cells dramatically increased during the retina development, and peaked at P7. As maturation continued, these cells decreased gradually. Apoptotic cells could not be found in the mature retina. Cell proliferation and apoptosis shows orderly and dynamic changes during the retina development, which is essential for the development of normal structure and function of the retina.

Pathogenicity differences between QX-like and Mass-type infectious bronchitis viruses

Infectious bronchitis is a highly contagious, acute viral respiratory disease of chickens, caused by infectious bronchitis virus (IBV). In recent years, the isolation rate of QX-like IBV has increased in the world. To clarify this phenomenon and better understand the pathogenicity of QX-like IBV, we examined differences in pathogenicity between two IBV strains, SD and M41, which belong to QX-like and Mass-type IBV, respectively. SD strain was more virulent in 3-week-old specific-pathogen-free chickens than M41 strain causing higher mortality with severe renal lesions. The tissue distribution of the two virus strains was tested by real-time RT-PCR. The results showed that the viral genome copy numbers in the tissues of chickens inoculated with SD strain were higher than those in chickens inoculated with M41 strain, with the exception of the trachea and lung. This study indicates that there are tremendous differences in pathogenicity and tissue tropism between the QX-like strain and Mass-type strain. These findings may benefit the prevention of infectious bronchitis in the poultry industry in China.

The first serological investigation of Chicken astrovirus infection in China

Chicken astrovirus (CAstV) is associated with 'white chick' syndrome, which increases embryo mortality and reduces hatchability in chickens. In the present study, 1760 sera were collected from 21 provinces in China to detect antibodies directed against CAstV with an ELISA. The sera were from different varieties of chicken in 85 flocks and all the flocks produced positive reactions. The overall seroprevalence in the birds tested was 60.68%. The prevalence increased from 34.17% to 74.44% with the increase of age. The positivity rates in layer flocks, layer parent flocks, broiler flocks, broiler parent flocks, and domestic chicken flocks were 70.17%, 89.00%, 31.67%, 59.05%, and 45.79%, respectively. These data indicate that CAstV infections are very common in China. This is the first report of the seroprevalence of CAstV infections in China.

Efficacy of an inactivated bivalent vaccine against the prevalent strains of Newcastle disease and H9N2 avian influenza

Background

Newcastle disease (ND) and avian influenza subtype H9N2 (H9N2 AI) are two of the most important diseases of poultry, causing severe economic losses in the global poultry industry. Vaccination is an effective way to prevent and control the spread of ND virus (NDV) and H9N2 AI virus (AIV), but the antigenic differences between the current circulating strains and the vaccine strains might account for recent ND and H9N2 AI outbreaks in vaccinated poultry flocks.

Methods

We developed an inactivated bivalent H9N2 and NDV vaccine based on the current prevalent strains of H9N2 AIV and NDV in China and evaluated its efficacy in chickens in this study.

Results

The results indicated that the inactivated bivalent vaccine could induce a fast antibody response in vaccinated chickens. The hemagglutination inhibition (HI) titer in the sera increased rapidly, and the highest HI titer was observed at 4 weeks post-vaccination (wpv) with a mean titre of 8.6 log₂ for NDV and 9.5 log₂ for H9N2. Up until 15 wpv, HI titers were still detectable at a high level of over 6 log₂. The immunized chickens showed no signs of disease after challenge at 3 wpv with the prevalent strains of NDV and H9N2 AIV isolated in 2012–2014. Moreover, viral shedding was completely inhibited in vaccinated chickens after challenge with H9N2 AIV and inhibited by at least 90% with NDV compared to the controls at 5dpc.

Conclusions

Our findings suggest that the inactivated NDV and H9N2 vaccine induces a fast and strong antibody response in vaccinated chickens and is efficacious in poultry against NDVs and H9N2 AIVs.

Analysis of antigenicity and pathogenicity reveals major differences among QX-like infectious bronchitis viruses and other serotypes

Avian coronavirus infectious bronchitis virus (IBV) causes considerable damage to the poultry industry worldwide and the proportion of QX-like genotype isolates have increased over time. Here, to better understand the antigenicity and pathogenicity of this genotype, we conducted sequence analyses, cross neutralization tests, and also examined the pathogenicity of two strains, SD and SZ. Sequence analyses revealed that SD and SZ isolates belong to the QX-like IBV genotype and share high homology in their full-length genomes. Cross neutralization tests showed high cross neutralization between SD and SZ, but distant relationships with other representative strains of the classical IBV serotypes. Virus infection experiments showed that SD caused high mortality with strong respiratory and renal pathogenicity in chickens, whereas SZ caused milder lesions by comparison. This study highlights the big discrepancy in antigenicity that exists between QX-like strains and other serotypes. Collectively, these findings provide important information about the epidemiology and pathogenicity of IBV, which may benefit the control of IB in the poultry industry.

Influenza A Viruses Replicate Productively in Mouse Mastocytoma Cells (P815) and Trigger Pro-inflammatory Cytokine and Chemokine Production through TLR3 Signaling Pathway

The influenza A viruses (IAVs) cause acute respiratory infection in both humans and animals. As a member of the initial lines of host defense system, the role of mast cells during IAV infection has been poorly understood. Here, we characterized for the first time that both avian-like (α-2, 3-linked) and human-like (α-2, 6- linked) sialic acid (SA) receptors were expressed by the mouse mastocytoma cell line (P815). The P815 cells did support the productive replication of H1N1 (A/WSN/33), H5N1 (A/chicken/ Henan/1/04) and H7N2 (A/chicken/Hebei/2/02) in vitro while the in vivo infection of H5N1 in mast cells was confirmed by the specific staining of nasal mucosa and lung tissue from mice. All the three viruses triggered the infected P815 cells to produce pro-inflammatory cytokines and chemokines including IL-6, IFN-γ, TNF-α, CCL-2, CCL-5, and IP-10, but not the antiviral type I interferon. It was further confirmed that TLR3 pathway was involved in P815 cell response to IAV-infection. Our findings highlight the remarkable tropism and infectivity of IAV to P815 cells, indicating that mast cells may be unneglectable player in the development of IAV infection.

Leakage Current Mechanism of InN-Based Metal-Insulator-Semiconductor Structures with Al2O3 as Dielectric Layers

InN-based metal-insulator-semiconductor (MIS) structures were prepared with Al2O3 as the gate oxides. Surface morphologies of InN films are improved with increasing Mg doping concentrations. At high frequencies, the measured capacitance densities deviate from the real ones with turning frequencies inversely proportional to series resistances. An ultralow leakage current density of 1.35 × 10(-9) A/cm(2) at 1 V is obtained. Fowler-Nordheim tunneling is the main mechanism of the leakage current at high fields, while Schottky emission dominates at low fields. Capacitance densities shift with different biases, indicating that the InN-based MIS structures can serve as potential candidates for MIS field-effect transistors.

Contribution of HN protein length diversity to Newcastle disease virus virulence, replication and biological activities

To evaluate the contribution of length diversity in the hemagglutinin-neuraminidase (HN) protein to the pathogenicity, replication and biological characteristics of Newcastle disease virus (NDV), we used reverse genetics to generate a series of recombinant NDVs containing truncated or extended HN proteins based on an infectious clone of genotype VII NDV (SG10 strain). The mean death times and intracerebral pathogenicity indices of these viruses showed that the different length mutations in the HN protein did not alter the virulence of NDV. In vitro studies of recombinant NDVs containing truncated or extended HN proteins revealed that the extension of HN protein increased its hemagglutination titer, receptor-binding ability and impaired its neuraminidase activity, fusogenic activity and replication ability. Furthermore, the hemadsorption, neuraminidase and fusogenic promotion activities at the protein level were consistent with those of viral level. Taken together, our results demonstrate that the HN biological activities affected by the C-terminal extension are associated with NDV replication but not the virulence.

Functional Study of Ectodysplasin-A Mutations Causing Non-Syndromic Tooth Agenesis

Recent studies have demonstrated that ectodysplasin-A (EDA) mutations are associated with non-syndromic tooth agenesis. Indeed, we were the first to report three novel EDA mutations (A259E, R289C and R334H) in sporadic non-syndromic tooth agenesis. We studied the mechanism linking EDA mutations and non-syndromic tooth agenesis in human embryonic kidney 293T cells and mouse ameloblast-derived LS8 cells transfected with mutant isoforms of EDA. The receptor binding capability of the mutant EDA1 protein was impaired in comparison to wild-type EDA1. Although the non-syndromic tooth agenesis-causing EDA1 mutants possessed residual binding capability, the transcriptional activation of the receptor's downstream target, nuclear factor κB (NF-κB), was compromised. We also analyzed the changes of selected genes in other signaling pathways, such as WNT and BMP, after EDA mutation. We found that non-syndromic tooth agenesis-causing EDA1 mutant proteins upregulate BMP4 (bone morphogenetic protein 4) mRNA expression and downregulate WNT10A and WNT10B (wingless-type MMTV integration site family member 10A and 10B) mRNA expression. Our results indicated that non-syndromic tooth agenesis causing EDA mutations (A259E, R289C and R334H) were loss-of-function, and suggested that EDA may regulate the expression of WNT10A, WNT10B and BMP4 via NF-κB during tooth development. The results from our study may help to understand the molecular mechanism linking specific EDA mutations with non-syndromic tooth agenesis.

Antigenic evolution of H9N2 chicken influenza viruses isolated in China during 2009-2013 and selection of a candidate vaccine strain with broad cross-reactivity

We previously demonstrated that H9N2 subtype avian influenza viruses (AIVs) isolated from 1994 to 2008 evolved into distinct antigenic groups (C, D, and E) and then underwent antigenic drift from commercial vaccines, causing a country-wide outbreak during 2010-2013. In this study, H9N2 AIVs isolated from chickens during 2009-2013 were antigenically analyzed by performing hemagglutination inhibition and neutralization assays using a panel of polyclonal antibodies. Our findings confirmed the antigenic drift of recent H9N2 viruses from the commercial vaccine and showed that most of these antigenic variants form a novel HI antigenic group, F, with a few belonging to groups D and E. Slight antigenic variation was observed in group F viruses. Genetic analysis of amino acid sequences deduced from hemagglutinin (HA) gene sequences indicated that 9 of 15 mutations predominant in the 2009-2013 viruses can be mapped to known antigenic sites, which might be responsible for the novel antigenicity of group F. These antigenic changes make it necessary to modify the influenza vaccine to ensure efficient protection. A vaccine candidate, Ck/HeB/YT/10, was selected and provided significant protection against viruses from different antigenic groups in terms of reduction in virus shedding, suggesting broad cross-reactivity. Taken together, our results indicate that the H9N2 chicken influenza viruses in China have evolved from distinct antigenic groups into a novel group F that became dominant during the country-wide outbreak and now seems to be undergoing new antigenic divergence. Systematic surveillance and timely updating of vaccine strains are important for viral prevention and control in the future.

Serological evidence of avian encephalomyelitis virus infection associated with vertical transmission in chicks

Avian encephalomyelitis virus (AEV) can be transmitted both horizontally and vertically. In the present study, we report a typical case of AEV infection in broiler breeder chickens and their progeny identified by clinical survey of the disease, antibody detection, and reverse transcription (RT)-polymerase chain reaction (PCR) assay.