In Vivo Molecular MRI Imaging of Prostate Cancer by Targeting PSMA with Polypeptide-Labeled Superparamagnetic Iron Oxide Nanoparticles.

The prostate specific membrane antigen (PSMA) is broadly overexpressed on prostate cancer (PCa) cell surfaces. In this study, we report the synthesis, characterization, in vitro binding assay, and in vivo magnetic resonance imaging (MRI) evaluation of PSMA targeting superparamagnetic iron oxide nanoparticles (SPIONs). PSMA-targeting polypeptide CQKHHNYLC was conjugated to SPIONs to form PSMA-targeting molecular MRI contrast agents. In vitro studies demonstrated specific uptake of polypeptide-SPIONs by PSMA expressing cells. In vivo MRI studies found that MRI signals in PSMA-expressing tumors could be specifically enhanced with polypeptide-SPION, and further Prussian blue staining showed heterogeneous deposition of SPIONs in the tumor tissues. Taken altogether, we have developed PSMA-targeting polypeptide-SPIONs that could specifically enhance MRI signal in tumor-bearing mice, which might provide a new strategy for the molecular imaging of PCa.

[Preparation and antithrombogenicity of oxidated low molecular weight heparin-antithrombin complex coated-polyvinyl chloride tubing].

Based on non-enzymatic protein glycated reaction, the sodium periodate-oxidated low molecular weight heparin-antithrombin covalent complex (SPLMWATH) was produced. By using polyethyleneimine-glutaraldehyde bonding technique, polyvinyl chloride (PVC) tubings were coated with SPLMWATH, heparin and low molecular weight heparin (LMWH). Spectrophotometry and dynamic clotting time experiment were used to determine the synthetic ratio of SPLMWATH, graft density, coating leaching ratio and to evaluate the antithrombogenicity of different coating on the PVC tubings. The results showed that the synthetic ratio of SPLMWATH was approximately 55%, and compared with heparin coating and LMWH coating, the graft density of SPLMWATH coating on the PVC tubing was smaller, but its coating stability and antithrombogenicity were significantly better than that of heparin coating and LMWH coating on the PVC tubings.

Enterovirus 71 induces neural cell apoptosis and autophagy through promoting ACOX1 downregulation and ROS generation.

Enterovirus 71 (EV71) infection causes hand, foot, and mouth disease (HFMD), and even fatal neurological complications. However, the mechanisms underlying EV71 neurological pathogeneses are largely unknown. This study reveals a distinct mechanism by which EV71 induces apoptosis and autophagy in neural cells. EV71 non-structure protein 3D (also known as RNA-dependent RNA polymerase, RdRp) interacts with the peroxisomal protein acyl-CoA oxidase 1 (ACOX1), and contributes to ACOX1 downregulation. Further studies demonstrate that EV71 reduces peroxisome numbers. Additionally, knockdown of ACOX1 or peroxin 19 (PEX19) induces apoptosis and autophagy in neural cells including human neuroblastoma (SK-N-SH) cells and human astrocytoma (U251) cells, and EV71 infection induces neural cell death through attenuating ACOX1 production. Moreover, EV71 infection and ACOX1 knockdown facilitate reactive oxygen species (ROS) production and attenuate the cytoprotective protein deglycase (DJ-1)/Nuclear factor erythroid 2-related factor 2 (NRF2)/Heme oxygenase 1 (HO-1) pathway (DJ-1/NRF2/HO-1), which collectively result in ROS accumulation in neural cells. In conclusion, EV71 downregulates ACOX1 protein expression, reduces peroxisome numbers, enhances ROS generation, and attenuates the DJ-1/NRF2/HO-1 pathway, thereby inducing apoptosis and autophagy in neural cells. These findings provide new insights into the mechanism underlying EV71-induced neural pathogenesis, and suggest potential treatments for EV71-associated diseases.

Enterovirus 71 Represses Interleukin Enhancer-Binding Factor 2 Production and Nucleus Translocation to Antagonize ILF2 Antiviral Effects.

Enterovirus 71 (EV71) infection causes hand-foot-mouth disease (HFMD), meningoencephalitis, neonatal sepsis, and even fatal encephalitis in children, thereby presenting a serious risk to public health. It is important to determine the mechanisms underlying the regulation of EV71 infection. In this study, we initially show that the interleukin enhancer-binding factor 2 (ILF2) reduces EV71 50% tissue culture infective dose (TCID50) and attenuates EV71 plaque-formation unit (PFU), thereby repressing EV71 infection. Microarray data analyses show that ILF2 mRNA is reduced upon EV71 infection. Cellular studies indicate that EV71 infection represses ILF2 mRNA expression and protein production in human leukemic monocytes (THP-1) -differentiated macrophages and human rhabdomyosarcoma (RD) cells. In addition, EV71 nonstructural protein 2B interacts with ILF2 in human embryonic kidney (HEK293T) cells. Interestingly, in the presence of EV71 2B, ILF2 is translocated from the nucleus to the cytoplasm, and it colocalizes with 2B in the cytoplasm. Therefore, we present a distinct mechanism by which EV71 antagonizes ILF2-mediated antiviral effects by inhibiting ILF2 expression and promoting ILF2 translocation from the nucleus to the cytoplasm through its 2B protein.

[Research on application of modified polyethylene glycol hydrogels in the construction of tissue engineered heart valve].

OBJECTIVE: To explore the effect of the polyethylene glycol (PEG)-hydrogels to enhance the seeding-cells adhesion to the biomaterial scaffolds. METHODS: Sixteen porcine aortic valves were decellularized with Triton X-100 and trypsin, then divided into A and B group, eight in each group. Group A: the donor goat's autologous bone marrow mesenchymal stem cells (BMSCs) Selected as the seeding-cells were encapsulated into the modified PEG-hydrogels to complete the process of the cells attaching to the acellular porcine aortic valves. Non-PEG but reservation of BMSCs was modified in Group B. After static culture for 7 d, the mono semilunar tissue engineering heart valve (TEHV) were implanted respectively into each donor goat's abdominal aortas. Gross and histology examination, ultrasonic scanning, electron microscopy observation and biomechanics detection were performed at 16 weeks after operation. The 8 native goat aortic valves from the donor goats were selected at the same time as control group (Group C). RESULTS: There were much more improvements compared Group A to Group B (P < 0.05) in tensile strength [(12.9 +/- 1.3) MPa vs. (8.8 +/- 0.4) MPa], ratio of re-endothelial (84.6% vs. 14.8%) and mural thrombosis (0/8 vs. 8/8). The data illustrated the critical importance of BMSCs differentiation to endothelial and myofibroblast for remodeling into native tissue in microenvironment in vivo. CONCLUSIONS: It is feasible to reconstruct TEHV efficiently by combining modified PEG-hydrogels with acellular biomaterial scaffold and autologous MSCs cells. It can improve the integration of the seeding-cells and scaffold. It can also protect the growth and differentiation of the BMSCs in the systemic circulation effectively.

[Construction and evaluation of the property of decellular porcine aortic valve].

OBJECTIVE: To construct decellular porcine aortic valve (PAV) and to observe the existence of porcine endogenous retrovirus (PERV) and valve scaffold structure before and after implantation. METHODS: (1) Porcine aortic valve was obtained. The cellular components of PAV were completely removed by using detergent and nucleotidase solution combined with alteration of osmosis. (2) The decellular underwent HE staining and light microscopy and detection of its physical and chemical properties. (3) 20 pieces of decellular PAV were implanted into dogs. On e month later blood samples of the dogs were collected. PCR and RT-PCR were used to detect the PERV expression in 20 samples of pig's peripheral blood, 20 fresh PAVs, cultured pig kidney cells of the PK15 line (as positive control), decellular PAVs implanted into the dogs, and 10 samples of dogs' peripheral blood. (4) Small pieces of decellular PAVs were implanted into the subcutaneous tissues of 6 rabbits at the back, 6 pieces for one rabbit, and then extracted by the ends of the 4th, 6th, 8th and 10th week respectively after implantation to undergo HE staining and light microscopy. RESULTS: (1) Almost all cellular components in the PAVs had been removed after decellularization; the soluble protein contents lost markedly [(0.238 +/- 0.038)% vs. (0.484 +/- 0.116)%]; the water content of the decellular tissues increased significantly [(92.16 +/- 1.48)% vs. (89.2 +/- 1.55)%]; however, the decellular PAVs still maintained their excellent fibrous scaffold structure, and their shrinkage temperature and tension at fracture were not significantly changed [(72.0 +/- 0.7) degrees C vs. (71.2 +/- 0.8) degrees C, and (448.7 +/- 18.65)g/mm2 vs. (540.7 +/- 19.46)g/mm2 respectively]. (2) Agarose gel electrophoresis of all fresh PAVs and porcine peripheral blood samples showed a 219 bp band, which was 90% to 97% homologous with PERV-C gene, and the sequence of which is published in Medline. No 219 bp amplified band was found in all decellular PAVs and the peripheral blood samples of the dogs implanted with decellular PAV one month after the implantation. (3) The PAVs implanted in rabbit body showed very slight tissue reaction. Neutrophil, lymphocyte and plasmacyte infiltration were seen 4 weeks after; such inflammatory cell infiltration decreased markedly and the peripheral portions of the decellular PAVs began to be absorbed by the end of the 6th week after implantation. The decellular PAVs were completely absorbed without fibrosis or scar formation in the implantation area by the end of the 10th week. CONCLUSION: (1) The cellular components of PAV can be completely removed, the excellent fibrous scaffold structure and mechanical strength of aorta valve can be maintained, and the antigenicity is very weak. Subcutaneous implantation investigation shows that decellular PAV is an absorbable and degradable biological material. (2) There is PERV-C in PAV that can be removed after decellularization. PERV-C reaction is negative in the peripheral blood samples of the recipients implanted with decellular PAV.

Tissue-engineered heart valve on acellular aortic valve scaffold: in-vivo study.

The feasibility of constructing a tissue-engineered heart valve on an acellular porcine aortic valve leaflet was evaluated. A detergent and enzymatic extraction process was developed to remove the cellular components from porcine aortic valves. The acellular valve leaflets were seeded for 7 days in vitro with cells from canine arterial wall and endothelial cells. The constructs were implanted into the lumens of 6 canine abdominal aortas to assess the reconstruction of the valve leaflets. It was found that all cellular components had been removed from the porcine aortic valves. The valve leaflets were completely reconstructed at the end of the 10th week in vivo. Scanning electron microscopy showed that the valve leaflets were partially covered with endothelial cells. It was concluded that porcine aortic valves can be decellularized by the detergent and enzymatic extraction process and it is feasible to construct a tissue-engineered heart valve in vivo on an acellular valve scaffold.

Co-circulation and genomic recombination of coxsackievirus A16 and enterovirus 71 during a large outbreak of hand, foot, and mouth disease in Central China.

A total of 1844 patients with hand, foot, and mouth disease (HFMD), most of them were children of age 1-3-year-old, in Central China were hospitalized from 2011 to 2012. Among them, 422 were infected with coxsackievirus A16 (CVA16), 334 were infected with enterovirus 71 (EV71), 38 were co-infected with EV71 and CVA16, and 35 were infected with other enteroviruses. Molecular epidemiology analysis revealed that EV71 and CVA16 were detected year-round, but EV71 circulated mainly in July and CVA16 circulated predominantly in November, and incidence of HFMD was reduced in January and February and increased in March. Clinical data showed that hyperglycemia and neurologic complications were significantly higher in EV71-infected patients, while upper respiratory tract infection and C-reactive protein were significantly higher in CVA16-associated patients. 124 EV71 and 80 CVA16 strains were isolated, among them 56 and 68 EV71 strains were C4a and C4b, while 25 and 55 CVA16 strains were B1a and B1b, respectively. Similarity plots and bootscan analyses based on entire genomic sequences revealed that the three C4a sub-genotype EV71 strains were recombinant with C4b sub-genotype EV71 in 2B-2C region, and the three CVA16 strains were recombinant with EV71 in 2A-2B region. Thus, CVA16 and EV71 were the major causative agents in a large HFMD outbreak in Central China. HFMD incidence was high for children among household contact and was detected year-round, but outbreak was seasonal dependent. CVA16 B1b and EV71 C4b reemerged and caused a large epidemic in China after a quiet period of many years. Moreover, EV71 and CVA16 were co-circulated during the outbreak, which may have contributed to the genomic recombination between the pathogens. It should gain more attention as there may be an upward trend in co-circulation of the two pathogens globally and the new role recombination plays in the emergence of new enterovirus variants.

Characterization of an outbreak of hand, foot, and mouth disease in Nanchang, China in 2010.

Recent outbreaks of human enterovirus 71 (EV71) infection and EV71-associated hand, foot, and mouth disease (HFMD) in China have affected millions and potentially lead to life-threatening complications in newborns. Furthermore, these outbreaks represent a significant global public health issue in the world. Understanding the epidemiology of HFMD and EV71 infection and their transmission patterns in China is essential for controlling outbreaks. However, no studies on the outbreaks of HFMD and EV71 infection in China during 2010 have been reported. In this report, we carried out an epidemiological analysis to study an outbreak of HFMD and EV71 infection in 2010 in the city of Nanchang in the Jiangxi province of People's Republic of China. From April 7 to May 11, 2010, a total of 109 HFMD cases were reported, and in this report the HFMD cases were studied by both epidemiological and laboratory analyses. The epidemiological study indicates that children aged younger than 8 years old represented more than 90% of the reported cases, with the age group of 1-3 years containing the highest number of cases. Laboratory studies detected a high prevalence of EV71 amongst the cases in our study, suggesting EV71 as a common enterovirus found in HFMD cases in Nanchang. Phylogenetic analysis of the sequence of the VP1 region of four EV71 isolates indicated that the Nanchang strains belong to the C4 subgenotype commonly found in China during outbreaks in 2008 but contain distinct variations from these strains. Our study for the first time characterizes the epidemiology of HFMD and EV71 infection in China in 2010 and furthermore, provides the first direct evidence of the genotype of EV71 circulating in Nanchang, China. Our study should facilitate the development of public health measures for the control and prevention of HFMD and EV71 infection in at-risk individuals in China.