Identification and comparison of the porcine H1, U6, and 7SK RNA polymerase III promoters for short hairpin RNA expression.

RNA polymerase III is an essential enzyme in eukaryotes for synthesis of tRNA, 5S rRNA, and other small nuclear and cytoplasmic RNAs. Thus, RNA polymerase III promoters are often used in small hairpin RNA (shRNA) expression. In this study, the porcine H1, U6, and 7SK RNA polymerase III type promoters were cloned into a pcDNA3.1( +) expression vector containing a shRNA sequence targeting enhanced green fluorescent protein (EGFP). PK and DF-1 cells were cotransfected with the construction of recombinant interference expression vector and the EGFP expression vector, pEGFP-N1. The average fluorescence intensity of EGFP in transfected cells was measured by fluorescence microscopy and flow cytometry. Real-time PCR was used to detect expressed shRNAs and the relative expression of EGFP, to confirm the activity of the promoters. The results showed that the activity of porcine 7SK promoter is stronger than the U6 promoter, which is in turn stronger than porcine H1. While the high levels of expression of the U6 and 7SK promoters saturate the shRNAs level in the host cell, which can cause cytotoxicity and tissue damage. Therefore, porcine H1 promoter is effective for expression of shRNA, and may be an excellent tool to knockdown gene expression in pigs for functional genomics studies. The results also lay a foundation for the development of porcine RNAi technology and genetically modified porcine research.

Neuroprotective properties of Madecassoside from Centella asiatica after hypoxic-ischemic injury.

Madecassoside is one of increasingly used constituent of Centella asiatica, a frequently prescribed crude drug in South eastern Asia and China for wound healing. In the present experiment, it exposes the neuroprotective nature of Madecassoside in GT1-7 cell lines, further, which the antioxidant activities are performed. The cellular toxicity was assessed using 3-(4,5-Dimethylthiazol-2-Yl)-2,5-Diphenyltetrazolium Bromide (MTT) assay with increased cell viability with IC50 2.5µg/ml. the regulation of antioxidant levels showed changes in madecassoside treated cell lysate viz., SOD assay. Also, the antioxidative assays confirmed the negligible cellular damage caused to the GT1-7 cell lines. Hence, the results advocate that the current antioxidant and antitumor activity be justified by the high concentration of phenolic constituents, primarily the triterpene present in the C. asiatica.

Mice transgenic for equine cyclin T1 and ELR1 are susceptible to equine infectious anemia virus infection.

BACKGROUND: As a member of the tumor necrosis factor receptor (TNFR) protein superfamily, equine lentivirus receptor 1 (ELR1) has been shown to be expressed in various equine cells that are permissive for equine infectious anemia virus (EIAV) replication. The EIAV Tat protein (eTat) activates transcription initiated at the viral long terminal repeat (LTR) promoter through a unique mechanism that requires the recruitment of the equine cyclin T1 (eCT1) cofactor into the viral TAR RNA target element. In vitro studies have demonstrated that mouse fibroblast cell lines (e.g., NIH 3T3 cells) that express the EIAV receptor ELR1 and eCT1 support the productive replication of EIAV. Therefore, we constructed transgenic eCT1- and ELR1-expressing mice to examine whether they support in vivo EIAV replication. FINDINGS: For the first time, we constructed mice transgenic for ELR1 and eCT1. Real-time reverse transcription polymerase chain reaction (RT-PCR) and Western blot analysis confirmed that ELR1 and eCT1 were expressed in the transgenic mouse tissues, particularly in the intestines, spleen and lymph nodes. Consistent with the results of EIAV infection in NIH 3T3 cells expressing ELR1 and eCT1, mouse embryonic fibroblasts (MEFs) from the transgenic mice could support EIAV replication. More importantly, this virus could infect and replicate in mouse blood monocyte-derived macrophages (mMDMs). Macrophages are the principle target cell of EIAV in its natural hosts. Furthermore, after the transgenic mice were inoculated with EIAV, the virus could be detected not only in the plasma of the circulating blood but also in multiple organs, among which, the spleen and lymph nodes were the predominant sites of EIAV replication. Finally, we found that consistent with high viral replication levels, the relevant pathological changes occurred in the spleen and lymph nodes. CONCLUSIONS: Our results show that mice transgenic for ELR1 and eCT1 are susceptible to EIAV infection and replication. Further, EIAV infection can cause lesions on the spleen and lymph nodes, similar to those frequently observed in horses, the natural hosts. Therefore, ELR1 and eCT1 are essential in vivo for EIAV invasion and replication.

Experimental study on the effect and mechanism of adipose stem cell-derived exosomes combined with botulinum toxin A on skin trauma in rats.

BACKGROUND: Adipose stem cell-derived exosomes (ADSC-EXO) and botulinum toxin type A (BTX-A) individually showed a therapeutic effect on skin wound repair. AIMS: This study investigated their synergistic effect on promoting skin wound healing in vitro and in vivo and the underlying molecular events. METHODS: ADSCs were isolated from Sprague-Dawley (SD) rats to obtain ADSC-EXO by ultrafiltration and ultracentrifugation and were confirmed using nanoparticle tracking analysis and transmission electron microscopy. Human skin fibroblasts (HSF) were cultured and treated with or without ADSC-EXO, BTX-A, or their combination. Changes in cell phenotypes and protein expression were analyzed using different in vitro assays, and a rat skin wound model was used to assess their in vivo effects. RESULTS: The isolated ADSC-EXO from primarily cultured ADSCs had a circular vesicle shape with a 30-180 nm diameter. Treatment of HSF with ADSC-EXO and/or BTX-A significantly accelerated HSF migration in vitro and skin wound healing in a rat model. Moreover, ADSC-EXO plus BTX-A treatment dramatically induced VEGFA expression but reduced COL III and COL I levels in vivo. ADSC-EXO and/or BTX-A treatment significantly upregulated TGF-ß3 expression on Day 16 after surgery but downregulated TGF-ß1 expression, suggesting that ADSC-EXO plus BTX-A promoted skin wound healing and reduced inflammatory cell infiltration. CONCLUSIONS: The ADSC-EXO plus BTX-A treatment demonstrated a synergistic effect on skin wound healing through upregulation of VEGF expression and the TGF-ß3/TGF-ß1 and COL III/COL I ratio.

Inhibition of avian leukosis virus subgroup J replication by miRNA targeted against env.

No effective vaccine has been developed against the subgroup J avian leukosis virus (ALV-J). The genetic diversity of ALV-J might be related to the env gene, therefore, we selected conserved sequences of the env gene and designed interference sequence. In this study, microRNAs (miRNAs) were designed and synthesized, corresponding to conserved regions of the env gene. These miRNAs were cloned into the linearized eukaryotic expression vector. The recombinant plasmids were transfected into DF-1 cells. After transfection, the cells were inoculated with ALV-J. In reporter assays, the transfection efficiency is 80% by indirect immunofluorescence (IFA). Expression of the virus envelope glycoprotein was measured by IFA and western blotting assays. The relative expression of env gene was determined using quantitative PCR. Our results show that the mi-env 231 and mi-env 1384 could effectively suppress the replication of ALV-J with an efficiency of 68.7-75.2%. These data suggest that the miRNAs targeting the env can inhibit replication of ALV-J efficiently. This finding provides evidence that miRNAs could be used as a potential tool against ALV infection.

[Prognostic significance of serum level of vascular endothelial growth factor receptor-2 in hepatocellular carcinoma patients after transcatheter arterial chemoembolization].

OBJECTIVE: To explore the prognostic significance of serum vascular endothelial growth factor receptor-2 (VEGFR-2) in patients with hepatocellular carcinoma (HCC) after transcatheter arterial chemoembolization (TACE). METHODS: A total of 69 HCC patients undergoing TACE from October 2008 to April 2012 were recruited and examined. Their serum level of VEGFR-2 level was measured by enzyme-linked immunosorbent assay (ELISA). The relationship between VEGFR-2 and their clinicopathologic features were observed. Prognostic significance of VEGFR-2 was assessed for their survival. RESULTS: Significant differences existed when the serum level of VEGFR-2 was categorized by tumor number and liver cirrhosis (P = 0.021, P = 0.049). The post-treatment serum level of VEGFR-2 was significant higher than that at pre-treatment (P = 0.045). When the mean pre-treatment serum level of VEGFR-2 (8709 ng/L) was used as a cut-off point, the patients with a low serum level of VEGFR-2 had better overall and progression-free survival than those with a high serum level of VEGF (17 vs. 28 months, P = 0.001 and 10 vs. 15 months P = 0.031 respectively). As revealed by multivariate Cox analysis, the pre-treatment serum level of VEGFR-2 was an independent and significant prognostic factor of survival for HCC patients at post-TACE. CONCLUSION: The pre-treatment serum level of VEGFR-2 may predict the post-TACE prognosis in HCC patients.

[Expression of serum microRNAs (miR-222, miR-181, miR-216) in human hepatocellular carcinoma and its clinical significance].

OBJECTIVE: To investigate the abnormal expression of microRNAs (miR-216, miR-222, miR-181) in the serum of patients with hepatocellular carcinoma (HCC) and its clinical significance. METHODS: Serum miRNAs expression was investigated in 49 patients with HCC and 25 healthy normal controls by using real-time PCR technique, and then correlations between miRNAs expression and the clinicopathological features and prognosis of HCC patients were evaluated. RESULTS: No differences were observed between the HCC patients and healthy controls with respect to the expressions of serum miR-181 and miR-216 (P > 0.05), while miR-222 was found to be significantly overexpressed in HCC serum samples (6.1 ± 6.6 vs 1.2 ± 0.6, P < 0.01). According to the median fold change of miR-222 (3-fold) in all HCC serum samples, we divided the 49 patients into two groups:a low expression group (25 patients) and a high expression group (24 patients).High level of miR-222 expression was correlated with cirrhosis (P < 0.01), tumor number (P = 0.013), portal vein tumor thrombosis (P = 0.002) and TNM stage (P = 0.020), while not correlated with serum alpha-fetoprotein level, tumor size and HbsAg. Kaplan-Meier survival analysis showed that the median overall survival in the high miR-222 expression group was significantly shorter than that in the low expression group (8.7 months vs 16.5 months, P = 0.036). In multivariate Cox analysis, TNM stage and serum miR-222 expression were two independent prognostic factors. CONCLUSION: Serum miR-222, upregulated in HCC, maybe helpful in prognosis of HCC patients.

Enhanced inhibition of Avian leukosis virus subgroup J replication by multi-target miRNAs.

BACKGROUND: Avian leukosis virus (ALV) is a major infectious disease that impacts the poultry industry worldwide. Despite intensive efforts, no effective vaccine has been developed against ALV because of mutations that lead to resistant forms. Therefore, there is a dire need to develop antiviral agents for the treatment of ALV infections and RNA interference (RNAi) is considered an effective antiviral strategy. RESULTS: In this study, the avian leukosis virus subgroup J (ALV-J) proviral genome, including the gag genes, were treated as targets for RNAi. Four pairs of miRNA sequences were designed and synthesized that targeted different regions of the gag gene. The screened target (i.e., the gag genes) was shown to effectively suppress the replication of ALV-J by 19.0-77.3%. To avoid the generation of escape variants during virus infection, expression vectors of multi-target miRNAs were constructed using the multi-target serial strategy (against different regions of the gag, pol, and env genes). Multi-target miRNAs were shown to play a synergistic role in the inhibition of ALV-J replication, with an inhibition efficiency of viral replication ranging from 85.0-91.2%. CONCLUSION: The strategy of multi-target miRNAs might be an effective method for inhibiting ALV replication and the acquisition of resistant mutations.

Expression and prognostic values of Id-1 and Id-3 in gastric adenocarcinoma.

BACKGROUND: Id (inhibitor of differentiation/DNA binding)-1 and -3 are involved in neoangiogenesis; they antagonize basic helix-loop-helix proteins, inhibit differentiation, and enhance cell proliferation. The aim of this study was to investigate Id-1 and -3 expression in gastric tumors and their clinical relevance in gastric cancer. MATERIALS AND METHODS: We investigated Id-1 and Id-3 expression in gastric cancer samples by immunohistochemistry and Western blotting, and further analyzed the relationship between expression of Id-1 and Id-3 and clinicopathologic characteristics. RESULTS: Expression of Id-1 and -3 was found significantly more often in gastric cancers than in matched adjacent nonmalignant tissues. Cancer samples with poor or moderate histologic differentiation showed significantly stronger Id-1 and -3 expression than cancer samples with high differentiation. In cancer samples, strong or moderate expression of Id-3, but not Id-1, was a strong independent predictor for shorter overall survival in multivariate analysis. CONCLUSIONS: The level of Id-1 and -3 protein expression was associated with the malignant potential of gastric tumors. In cancer samples, stronger Id-1 and -3 expression is associated with poor differentiation and more aggressive behavior of tumor cells, resulting in poor clinical outcome. Consequently, Id-3 might be used to independently predict survival of patients with gastric cancer.

Production of transgenic broilers by non-viral vectors via optimizing egg windowing and screening transgenic roosters.

The generation of transgenic chickens is of both biomedical and agricultural significance, and recently chicken transgenesis technology has been greatly advanced. However, major issues still exist in the efficient production of transgenic chickens. This study was designed to optimize the production of enhanced green fluorescence protein (EGFP)-transgenic broilers, including egg windowing at the blunt end (air cell) of egg, and the direct transfection of circulating primordial germ cells by microinjection of the Tol2 plasmid-liposome complex into the early embryonic dorsal aorta. For egg windowing, we discovered that proper manipulation of the inner shell membrane at the blunt end could improve the rate of producing G0 transgenic roosters. From 27 G0 roosters, we successfully collected semen with EGFP-positive sperms from 16 and 19 roosters after direct fluorescence observation and fluorescence-activated cell sorting analyses (13 detected by both methods), respectively. After artificial insemination using the G0 rooster with the highest number of EGFP fluorescent sperm, one G1 EGFP transgenic broiler (1/81, 1.23%) was generated. Our results indicate that appropriate egg windowing and screening of potentially transgene-positive roosters can improve the production of germline-transmitted transgenic birds.

1A and 3D gene sequences of coxsackievirus B3 strain CC: variation and phylogenetic analysis.

Coxsackievirus B3 (CVB3) was thought to be the most common causative agent of life-threatening viral myocarditis. Coxsackievirus B3 strain CC (CVB3-CC) was isolated in China; however, no sequence data are available. The 1A and 3D regions of CVB3-CC were sequenced and phylogenetic analysis was done with reference to ten other CVB3 strains and all 36 prototype strains of human enterovirus B (HEV-B). Sequence analysis showed that the 1A gene region of CVB3-CC consisted of 207 nucleotides, encoding 69 amino acids; and the 3D gene region was comprised of 1386 nucleotides, encoding 462 amino acids. Variation analysis showed that the 3D gene of CVB3 strain CC varied the least among the two regions. Phylogenetic tree analysis of the 1A and 3D regions indicated that CVB3-CC clustered together with CVB3 Nancy strain suggesting that there may be a close evolutionary relationship between the two strains. Incongruity was observed between the non-structural protein gene and the structural protein gene trees, according to the topological structure, indicating that recombination was occurred among these strains.

[Study on the animal model for severe acute respiratory syndrome].

To screen small animals susceptible to SARS-CoV, five species of animals, including guinea pig, hamster, albino hamster, chicken and rat, were experimentally infected with SARS-CoV strain BJ-01 by different routes. On the basis of this, further cynomolgus and rhesus macaques were selected and experimentally inoculated SARS-CoV, the quality they serve as animal model for SARS was evaluated. The results showed that, all five species of small animals chosed were not susceptible to SARS-CoV, no characterized changes in clinical sign and histopathology were observed after infection, but from the lung samples of large rat and pig guinea, the genomic RNA of SARS-CoV could be detected by RT-PCR at day 14 post infection, this suggested that SARS-CoV could replicate in these animals. After inoculated with SARS-CoV, all inoculated cynomolgus and rhesus macaques had developed interstitial pneumonia of differing severity. These changes on histopathology were similar to that seen in SARS patients, but the pathological lesions were less severe than that of human. Except interstitial pneumonia, no other characterized pathological changes were observed. This suggested cynomolgus and rhesus macaques were not the ideal animal model for SARS in fact, but they could serve as animal model for SARS when a more ideal animal model is absent.

Prognostic value of serum vascular endothelial growth factor receptor 2 response in patients with hepatocellular carcinoma undergoing transarterial chemoembolization.

We aimed to elucidate whether serum VEGFR2 concentration before and after transarterial chemoembolization (TACE) can predict survival in patients with unresectable hepatocellular carcinoma (HCC). Serum VEGFR2 concentrations were serially measured in 169 patients with advanced HCC before and after TACE. We defined a decrease in the serum VEGFR2 level>10% from the pretreatment level as response. Serum VEGFR2 concentrations decreased in 44 (26.0%) patients at week 4. Patients who had a VEGFR2 response at week 4 had a longer median survival than those who did not have a VEGFR2 decrease (19.0 vs. 9.8 months, p<0.001). Clinical variables associated with OS in addition to VEGFR2 response also included extrahepatic metastases (p=0.005) and vascular invasion (p=0.035). VEGFR2 decrease after TACE (p=0.012) and presence of extrahepatic metastases (p=0.02) were independently associated with OS by multivariate analysis. A serum VEGFR2 concentration decrease at 4 weeks after TACE may predict favorable overall survival in patients with advanced HCC.

Protection of chickens against highly lethal H5N1 and H7N1 avian influenza viruses with a recombinant fowlpox virus co-expressing H5 haemagglutinin and N1 neuraminidase genes.

Inactivated whole avian influenza virus (AIV) vaccine provides protection against homologous haemagglutinin (HA) subtype virus, but poor protection against a heterologous HA virus. Moreover, it induces chickens to produce antibodies to cross-reactive antigens, especially nucleoprotein, which is limits AIV serological surveillance. In this study, a recombinant fowlpox virus co-expressing HA (H5 subtype) and NA (NI subtype)genes of AIV was evaluated for its ability to protect chickens against intramuscular challenge with a lethal dose of highly pathogenic (HP) AIV. Susceptible chickens were also vaccinated by wing-web puncture with the parent fowlpox vaccine virus. Following challenge 4 weeks later with HPAIV, all chickens vaccinated with recombinant virus were protected, while the chickens vaccinated with either the unaltered parent fowlpox vaccine virus or unvaccinated controls experienced 100% mortality following challenge. This protection was accompanied by the high levels of specific antibody to the respective components of the recombinant vaccine. The above results showed that rFPV-HA-NA could be a potential vaccine to replace current inactivated vaccines for preventing AI.