279 research outputs found
Immunomodulatory and anti-viral effects of statins in influenza H5N1 virus infection of human alveolar epithelial cells and peripheral blood–derived macrophages
Poster Session: Novel TherapeuticsBackground: Highly pathogenic avian influenza (HPAI) H5N1 virus panzootic in poultry continues to
spread. It causes zoonotic human disease with a high (> 60%) fatality rate and continues to pose a
pandemic threat. Based on clinical, animal, and in vitro cell studies, we and others have suggested
that differences in viral replication competence, tissue tropism, and cytokine dysregulation between
H5N1 and low pathogenic viruses may contribute to disease pathogenesis. Statins as HMG-CoA
inhibitors act to reduce cholesterol and have been demonstrated to have anti-inflammatory and
immune-modulatory activities. However, there is controversy about the benefits of statin use on
influenza infection in mice and humans. In this study, we aimed to evaluate the effects of statin treatment in influenza infection using physiologically relevant in vitro models—human alveolar
epithelial cells (AECs) and peripheral blood–derived macrophages (PBDMs). Materials and Methods:
Primary human AECs and PBDMs were infected with HPAI H5N1 (A/HK/483/97) and seasonal H1N1
(A/HK/54/98) viruses in the presence or absence of statin (simvastatin and sevastatin) treatment.
Virus replication was monitored by measuring infectious viral particles in cell culture supernatants
using TCID50. Immuno-modulatory effects of statins were examined by measuring the mRNA and
protein expression of cytokines and chemokines using qPCR and ELISA. In order to understand the
intervention of statins and influenza infection, the gene expression profile of selected members of the
sterol-biosynthesis pathway in influenza virus–infected AECs and PBDMs were also monitored. The
responses of a variety of cytokine treatments on the genes of the sterol-biosynthesis pathway were
investigated in AECs. Furthermore, the intracellular free cholesterol level was also examined by
enzymatic assay in AECs infected with influenza virus. Results: We demonstrated that both
simvastatin and mevastatin exhibited a dose-dependent inhibition of influenza virus replication for
both HPAI H5N1 and seasonal H1N1 viruses in human AECs and PBDMs. The observed inhibitory
effect of simvastatin and mevastatin occurred below the non-specific toxic effects to cells, which were
measured by MTT assay. Treatment of simvastatin and mevastatin significantly suppressed H5N1
virus–induced pro-inflammatory cytokines such as TNF-α in PBDMs and chemokines, including IP-10
and MCP-1 secretion in both AECs and PBDMs at 24 hours post-infection. We further showed that
human AECs and PBDMs infected with both HPAI H5N1 and seasonal H1N1 viruses had significant
down-regulation of sterol pathway gene expression at 24 hours post-infection. AECs and PBDMs
treated with IFN-γ or IFN-β but not IL-1β, TNF, or IL-6, showed down-regulation of sterol pathway
gene expression. In addition, we found that the free cholesterol level was significantly reduced at 24
and 48 h post-H5N1 virus infection in AECs and in IFN-β–treated AECs. These results further support
a specific modulation of the sterol metabolic pathway upon influenza virus infection. Conclusions:
Taken together, the controversy about the beneficial effects of statin use in influenza infection and our
data suggest that statins possess both the antiviral and immune-regulatory effects in H5N1-infected in
vitro cell models. We also demonstrated a highly specific response of AECs and PBDMs through a
coordinated negative regulation of multiple sterol pathway members upon influenza virus infection or
treatment of interferon. Identification of a reduction in sterol pathway gene expression and cholesterol
levels with IFN treatment in human AECs offers new insights on the host-mediated antiviral responses
through the sterol metabolism pathway and opens new therapeutic options for human influenza
disease.published_or_final_versio
Highly pathogenic avian influenza H5N1 virus delays apoptotic responses via activation of STAT3
Highly pathogenic avian influenza (HPAI) H5N1 virus continues to pose pandemic threat, but there is a lack of understanding of its pathogenesis. We compared the apoptotic responses triggered by HPAI H5N1 and low pathogenic H1N1 viruses using physiologically relevant respiratory epithelial cells. We demonstrated that H5N1 viruses delayed apoptosis in primary human bronchial and alveolar epithelial cells (AECs) compared to H1N1 virus. Both caspase-8 and -9 were activated by H5N1 and H1N1 viruses in AECs, while H5N1 differentially up-regulated TRAIL. H5N1-induced apoptosis was reduced by TRAIL receptor silencing. More importantly, STAT3 knock-down increased apoptosis by H5N1 infection suggesting that H5N1 virus delays apoptosis through activation of STAT3. Taken together, we demonstrate that STAT3 is involved in H5N1-delayed apoptosis compared to H1N1. Since delay in apoptosis prolongs the duration of virus replication and production of pro-inflammatory cytokines and TRAIL from H5N1-infected cells, which contribute to orchestrate cytokine storm and tissue damage, our results suggest that STAT3 may play a previously unsuspected role in H5N1 pathogenesis.published_or_final_versio
Tropism and innate host responses of a novel avian influenza A H7N9 virus: an analysis of ex-vivo and in-vitro cultures of the human respiratory tract
BACKGROUND: Since March, 2013, an avian-origin influenza A H7N9 virus has caused severe pneumonia in China. The aim of this study was to investigate the pathogenesis of this new virus in human beings. METHODS: We obtained ex-vivo cultures of the human bronchus, lung, nasopharynx, and tonsil and in-vitro cultures of primary human alveolar epithelial cells and peripheral blood monocyte-derived macrophages. We compared virus tropism and induction of proinflammatory cytokine responses of two human influenza A H7N9 virus isolates, A/Shanghai/1/2013 and A/Shanghai/2/2013; a highly pathogenic avian influenza H5N1 virus; the highly pathogenic avian influenza H7N7 virus that infected human beings in the Netherlands in 2003; the 2009 pandemic influenza H1N1 virus, and a low pathogenic duck H7N9 virus that was genetically different to the human disease causing A H7N9 viruses. FINDINGS: Both human H7N9 viruses replicated efficiently in human bronchus and lung ex-vivo cultures, whereas duck/H7N9 virus failed to replicate in either. Both human A H7N9 viruses infected both ciliated and non-ciliated human bronchial epithelial cells and replicated to higher titres than did H5N1 (p<0·0001 to 0·0046) and A/Shanghai/1/2013 replicated to higher titres than did H7N7 (p=0·0002-0·01). Both human A H7N9 viruses predominantly infected type II alveolar epithelial cells and alveolar macrophages in the human lung and replicated to higher titres than did H5N1 (p<0·0001 to 0·0078); A/Shanghai/1/2013 replicated to higher titres than did H1N1 (p=0·0052-0·05) and H7N7 (p=0·0031-0·0151). Human H7N9 viruses were less potent inducers of proinflammatory cytokines compared with H5N1 virus. INTERPRETATION: Collectively, the results suggest that the novel H7N9 viruses are better adapted to infect and replicate in the human conducting and lower airways than are other avian influenza viruses, including H5N1, and pose an important pandemic threat.postprin
Cooperation of decay-accelerating factor and membrane cofactor protein in regulating survival of human cervical cancer cells
<p>Abstract</p> <p>Background</p> <p>Decay-accelerating factor (DAF) and membrane cofactor protein (MCP) are the key molecules involved in cell protection against autologus complement, which restricts the action of complement at critical stages of the cascade reaction. The cooperative effect of DAF and MCP on the survival of human cervical cancer cell (ME180) has not been demonstrated.</p> <p>Methods</p> <p>In this study we applied, for the first time, short hairpin RNA (shRNA) to knock down the expression of the DAF and MCP with the aim of exploiting complement more effectively for tumor cell damage. Meanwhile, we investigated the cooperative effects of DAF and MCP on the viability and migration, moreover the proliferation of ME180 cell.</p> <p>Results</p> <p>The results showed that shRNA inhibition of DAF and MCP expression enhanced complement-dependent cytolysis (CDC) up to 39% for MCP and up to 36% for DAF, and the combined inhibition of both regulators yielded further additive effects in ME180 cells. Thus, the activities of DAF and MCP, when present together, are greater than the sum of the two protein individually.</p> <p>Conclusion</p> <p>These data indicated that combined DAF and MCP shRNA described in this study may offer an additional alternative to improve the efficacy of antibody-and complement-based cancer immunotherapy.</p
Antimetastatic Effects of Norcantharidin on Hepatocellular Carcinoma by Transcriptional Inhibition of MMP-9 through Modulation of NF-kB Activity
The rate of morbidity and mortality of hepatocellular carcinoma (HCC) in Taiwan has not lessened because of difficulty in treating tumor metastasis. Norcantharidin (NCTD) is currently used as an anticancer drug for hepatoma, breast cancer, and colorectal adenocarcinoma. NCTD possesses various biological anticancer activities, including apoptosis. However, detailed effects and molecular mechanisms of NCTD on metastasis are unclear. Thus, HCC cells were subjected to treatment with NCTD and then analyzed to determine the effects of NCTD on cell metastasis.Modified Boyden chamber assays revealed that NCTD treatment inhibited cell migration and invasion capacities of HCC cells substantially. Results of zymography and western blotting showed that activities and protein levels of matrix metalloproteinase-9 (MMP-9) and urokinase plasminogen activator (u-PA) were inhibited by NCTD. Western blot analysis showed that NCTD inhibits phosphorylation of ERK1/2. Testing of mRNA level, quantitative real-time PCR, and promoter assays evaluated the inhibitory effects of NCTD on MMP-9 and u-PA expression in HCC cells. The chromatin immunoprecipitation (ChIP) assay for analyzing the genomic DNA sequences bound to these proteins was reactive to the transcription protein nuclear factor (NF)-kappaB, which was inhibited by NCTD. The expression of NF-kappa B was measured by western blot analysis, which revealed decreased nuclear-factor DNA-binding activity after NCTD treatment.NCTD inhibited MMP-9 and u-PA expression through the phosphorylation of ERK1/2 and NF-kappaB signaling pathway which serves as a powerful chemopreventive agent in HCC cell metastasis
Chromosome 2p14 Is Linked to Susceptibility to Leprosy
BACKGROUND: A genetic component to the etiology of leprosy is well recognized but the mechanism of inheritance and the genes involved are yet to be fully established. METHODOLOGY: A genome-wide single nucleotide polymorphism (SNP) based linkage analysis was carried out using 23 pedigrees, each with 3 to 7 family members affected by leprosy. Multipoint parametric and non-parametric linkage analyses were performed using MERLIN 1.1.1. PRINCIPAL FINDINGS: Genome-wide significant evidence for linkage was identified on chromosome 2p14 with a heterogeneity logarithm of odds (HLOD) score of 3.51 (rs1106577) under a recessive model of inheritance, while suggestive evidence was identified on chr.4q22 (HLOD 2.92, rs1349350, dominant model), chr. 8q24 (HLOD 2.74, rs1618523, recessive model) and chr.16q24 (HLOD 1.93, rs276990 dominant model). Our study also provided moderate evidence for a linkage locus on chromosome 6q24-26 by non-parametric linkage analysis (rs6570858, LOD 1.54, p = 0.004), overlapping a previously reported linkage region on chromosome 6q25-26. CONCLUSION: A genome-wide linkage analysis has identified a new linkage locus on chromosome 2p14 for leprosy in Pedigrees from China
Caregiver awareness of reproductive health issues for women with intellectual disabilities
<p>Abstract</p> <p>Background</p> <p>Limited attention has been paid to the issue of reproductive health as it affects women with intellectual disabilities, despite reproductive health being a vital issue in public health policy for women in the general population. This paper describes caregiver awareness of reproductive health issues relative to women with intellectual disabilities who are being cared for in welfare institutions in Taiwan.</p> <p>Methods</p> <p>The study employed a cross-sectional, questionnaire-based study which recruited 1,152 caregivers (response rate = 71.87%) from 32 registered disability welfare institutions in Taiwan. We classified their understanding/awareness of reproductive health issues into four domains: menstrual (1) and menopause (2) issues, sex education (3), and reproductive health services (4). Each domain had five associated yes/no questions and the total score for the four domains was out of a maximum of 20. Data were analyzed using SPSS 15.0 software.</p> <p>Results</p> <p>We found that most of the caregivers were familiar with matters concerning sex education, menopause, and reproductive health services, but they lacked adequate understanding of issues associated with menstruation in women with ID. Many aspects of reproductive health such as "menstrual pain", "age at menarche", "masturbation", "diet during perimenopause", and "publicly available reproductive health services" were issues in which caregivers lacked adequate knowledge and required further instruction. Logistic regression analysis revealed that female caregivers with a university degree, and those who had experience assisting with reproductive health care were more inclined to have higher reproductive health awareness scores than their counterparts.</p> <p>Conclusions</p> <p>This study highlights that service providers should offer appropriate reproductive health education to institutional caregivers, and that more attention be focused on the personal experiences and concerns of intellectually disabled women in future research.</p
The neck-region polymorphism of DC-SIGNR in peri-centenarian from Han Chinese Population
<p>Abstract</p> <p>Background</p> <p>DC-SIGNR (also called CD209L) has been extensively studied on its role in host genetic predisposition to viral infection. In particular, variable number tandem repeat (VNTR) of the neck-region of DC-SIGNR is highly polymorphic and the polymorphism has been investigated for genetic predisposition to various infectious diseases, though conflicting results had been reported. As infection is a major cause of human death and a mechanism of natural selection, we hypothesized that VNTR polymorphism of DC-SIGNR might have an effect on human life span.</p> <p>Methods</p> <p>Here we collected 361 peri-centenarian individuals (age ≥94 for female and age ≥90 for male) and 342 geographically matched controls (age 22-53, mean 35.0 ± 12.0) from Han Chinese. The VNTR polymorphism of the neck region was determined by PCR and genotype was called by separating the PCR products in agarose gel.</p> <p>Results</p> <p>A total of 11 genotypes and 5 alleles were found in our population. The genotype distribution, allele frequencies and homozygote proportion did not show a significant difference between peri-centenarian and control group. As gender differences in lifespan are ubiquitously observed throughout the animal kingdom, we then stratified the samples by gender. There was more 6/7 genotypes in female peri-centenarian group than that in female control group, at a marginal level of significance (5.56 vs. 1.28%, p = 0.041). The difference was not significant after correction by Bonferroni method. It suggests a possible differential effect of DC-SIGNR VNTR genotypes between sexes. Further studies are warranted to confirm our preliminary findings and investigate the mechanisms of the underlying functions.</p> <p>Conclusions</p> <p>Our study indicated that there was absence of association between the neck region polymorphism of DC-SIGNR and longevity in Han Chinese population. But the question of whether the DC-SIGNR could affect longevity in a gender-specific pattern remains open.</p
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