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1.
J Virol ; 94(16)2020 07 30.
Artigo em Inglês | MEDLINE | ID: mdl-32493816

RESUMO

Sirtuin 2 (Sirt2), an NAD+-dependent protein deacetylase, deacetylates tubulin, AKT, and other proteins. Previously, we showed that Sirt2 isoform 1 (Sirt2.1) increased replication of hepatitis B virus (HBV). Here, we show that HBV replication upregulates the expression of Sirt2 primary and alternatively spliced transcripts and their respective isoforms, 1, 2, and 5. Since Sirt2 isoform 5 (Sirt2.5) is a catalytically inactive nuclear protein with a spliced-out nuclear export signal (NES), we speculated that its different localization affects its activity. The overexpression of Sirt2.5 reduced expression of HBV mRNAs, replicative intermediate DNAs, and covalently closed circular DNA (cccDNA), an activity opposite that of Sirt2.1 and Sirt2.2. Unlike the Sirt2.1-AKT interaction, the Sirt2.5-AKT interaction was weakened by HBV replication. Unlike Sirt2.1, Sirt2.5 activated the AKT/GSK-3ß/ß-catenin signaling pathway very weakly and independently of HBV replication. When the NES and an N-terminal truncated catalytic domain were added to the Sirt2.5 construct, it localized in the cytoplasm and increased HBV replication (like Sirt2.1 and Sirt2.2). Chromatin immunoprecipitation assays revealed that more Sirt2.5 was recruited to cccDNA than Sirt2.1. The recruitment of histone lysine methyltransferases (HKMTs), such as SETDB1, SUV39H1, EZH2, and PR-Set7, and their respective transcriptional repressive markers, H3K9me3, H3K27me3, and H4K20me1, to cccDNA also increased in Sirt2.5-overexpressing cells. Among these, the Sirt2.5-PR-Set7 and -SETDB1 interactions increased upon HBV replication. These results demonstrate that Sirt2.5 reduces cccDNA levels and viral transcription through epigenetic modification of cccDNA via direct and/or indirect association with HKMTs, thereby exhibiting anti-HBV activity.IMPORTANCE Sirt2, a predominant cytoplasmic α-tubulin deacetylase, promotes the growth of hepatocellular carcinoma; indeed, HBV replication increases Sirt2 expression, and overexpression of Sirt2 is associated with hepatic fibrosis and epithelial-to-mesenchymal transition. Increased amounts of Sirt2 isoforms 1, 2, and 5 upon HBV replication might further upregulate HBV replication, leading to a vicious cycle of virus replication/disease progression. However, we show here that catalytically inactive nuclear Sirt2.5 antagonizes the effects of Sirt2.1 and Sirt2.2 on HBV replication, thereby inhibiting cccDNA level, transcription of cccDNA, and subsequent synthesis of replicative intermediate DNA. More Sirt2.5 was recruited to cccDNA than Sirt2.1, thereby increasing epigenetic modification by depositing transcriptional repressive markers, possibly through direct and/or indirect association with histone lysine methyltransferases, such as SETDB1, SUV39H1, EZH2, and/or PR-Set7, which represses HBV transcription. Thus, Sirt2.5 might provide a functional cure for HBV by silencing the transcription of HBV.


Assuntos
DNA Circular/genética , Vírus da Hepatite B/fisiologia , Histona-Lisina N-Metiltransferase/genética , Sirtuína 2/genética , Replicação Viral/genética , Processamento Alternativo , Linhagem Celular Tumoral , DNA Circular/metabolismo , DNA Viral/genética , DNA Viral/metabolismo , Epigênese Genética , Repressão Epigenética , Hepatite B/virologia , Vírus da Hepatite B/genética , Vírus da Hepatite B/crescimento & desenvolvimento , Histona-Lisina N-Metiltransferase/metabolismo , Histonas/metabolismo , Humanos , Isoformas de Proteínas , Sirtuína 2/metabolismo , Transcrição Gênica , Ativação Transcricional
2.
Virol J ; 18(1): 34, 2021 02 13.
Artigo em Inglês | MEDLINE | ID: mdl-33581714

RESUMO

Rapid diagnosis of SARS-CoV-2 during pandemic enables timely treatment and prevention of COVID-19. Evaluating the accuracy and reliability of rapid diagnostic testing kits is crucial for surveillance and diagnosis of SARS-CoV-2 infections in general population, injection drug users, multi-transfused populations, healthcare workers, prisoners, barbers and other high risk populations. The aim of this study was to evaluate performance and effectiveness of nasopharyngeal swab (NSP) and saliva based rapid antigen detection testing kits in comparison with USFDA approved triple target gold standard real-time polymerase chain reaction. A cross-sectional study was conducted on 33,000 COVID-19 suspected patients. From RT-PCR positive patients, nasopharyngeal swab (NSP) and saliva samples were obtained for evaluation of rapid COVID-19 testing kits (RDT). 100/33,000 (0.3%) of specimens were RT-PCR positive for SARS-CoV-2. Among RT-PCR positive, 62% were males, 34% were females, and 4% were children. The NSP-RDT (Lepu Medical China) analysis revealed 53% reactivity among males, 58% reactivity among females, and 25% reactivity among children. However saliva based RDT (Lepu Medical China) analysis showed 21% reactivity among males and 23% among females, and no reactivity in children. False negative results were significantly more pronounced in saliva based RDT as compared to NSP-RDT. The sensitivity of these NSP-RDT and saliva based RDT were 52% and 21% respectively. The RDTs evaluated in this study showed limited sensitivities in comparison to gold standard RT-PCR, indicating that there is a dire need in Pakistan for development of suitable testing to improve accurate COVID-19 diagnosis in line with national demands.


Assuntos
Antígenos Virais/isolamento & purificação , Teste Sorológico para COVID-19/métodos , COVID-19/diagnóstico , SARS-CoV-2/isolamento & purificação , Adolescente , Adulto , Idoso , Idoso de 80 Anos ou mais , Antígenos Virais/imunologia , COVID-19/epidemiologia , COVID-19/imunologia , COVID-19/virologia , Criança , Estudos Transversais , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Paquistão/epidemiologia , Kit de Reagentes para Diagnóstico , Reação em Cadeia da Polimerase em Tempo Real , Reprodutibilidade dos Testes , SARS-CoV-2/genética , SARS-CoV-2/imunologia , Adulto Jovem
3.
Can Assoc Radiol J ; 72(1): 109-119, 2021 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-32063026

RESUMO

BACKGROUND: The purpose of this study was to build radiogenomics models from texture signatures derived from computed tomography (CT) and 18F-FDG PET-CT (FDG PET-CT) images of non-small cell lung cancer (NSCLC) with and without epidermal growth factor receptor (EGFR) mutations. METHODS: Fifty patients diagnosed with NSCLC between 2011 and 2015 and with known EGFR mutation status were retrospectively identified. Texture features extracted from pretreatment CT and FDG PET-CT images by manual contouring of the primary tumor were used to develop multivariate logistic regression (LR) models to predict EGFR mutations in exon 19 and exon 20. RESULTS: An LR model evaluating FDG PET-texture features was able to differentiate EGFR mutant from wild type with an area under the curve (AUC), sensitivity, specificity, and accuracy of 0.87, 0.76, 0.66, and 0.71, respectively. The model derived from CT texture features had an AUC, sensitivity, specificity, and accuracy of 0.83, 0.84, 0.73, and 0.78, respectively. FDG PET-texture features that could discriminate between mutations in EGFR exon 19 and 21 demonstrated AUC, sensitivity, specificity, and accuracy of 0.86, 0.84, 0.73, and 0.78, respectively. Based on CT texture features, the AUC, sensitivity, specificity, and accuracy were 0.75, 0.81, 0.69, and 0.75, respectively. CONCLUSION: Non-small cell lung cancer texture analysis using FGD-PET and CT images can identify tumors with mutations in EGFR. Imaging signatures could be valuable for pretreatment assessment and prognosis in precision therapy.


Assuntos
Carcinoma Pulmonar de Células não Pequenas/genética , Interpretação de Imagem Assistida por Computador/métodos , Genômica por Imageamento/métodos , Neoplasias Pulmonares/genética , Aprendizado de Máquina , Mutação/genética , Idoso , Carcinoma Pulmonar de Células não Pequenas/diagnóstico por imagem , Receptores ErbB/genética , Feminino , Fluordesoxiglucose F18 , Humanos , Pulmão/diagnóstico por imagem , Neoplasias Pulmonares/diagnóstico por imagem , Masculino , Tomografia por Emissão de Pósitrons combinada à Tomografia Computadorizada/métodos , Valor Preditivo dos Testes , Compostos Radiofarmacêuticos , Reprodutibilidade dos Testes , Estudos Retrospectivos , Sensibilidade e Especificidade
4.
J Virol ; 93(6)2019 03 15.
Artigo em Inglês | MEDLINE | ID: mdl-30567987

RESUMO

The parvulin 14 (Par14) and parvulin 17 (Par17) proteins, which are both encoded by the PIN4 gene, play roles in protein folding, chromatin remodeling, DNA binding, ribosome biogenesis, and cell cycle progression. However, the effects of Par14 and Par17 on viral replication have never been explored. In this study, we found that, in the presence of HBx, either Par14 or Par17 could upregulate hepatitis B virus (HBV) replication, whereas in the absence of HBx, neither Par14 nor Par17 had any effect on replication. Overexpression of Par14/Par17 markedly increased the formation of covalently closed circular DNA (cccDNA), synthesis of HBV RNA and DNA, and virion secretion. Conversely, PIN4 knockdown significantly decreased HBV replication in HBV-transfected and -infected cells. Coimmunoprecipitation revealed that Par14/Par17 engaged in direct physical interactions with HBx in the cytoplasm, nucleus, and mitochondria, possibly mediated through substrate-binding residues on Par14/Par17 (E46/D74 and E71/D99, respectively) and conserved 19R20P-28R29P motifs on HBx. Furthermore, these interactions enhanced HBx stability, promoted HBx translocation to the nuclear and mitochondrial fractions, and increased HBV replication. Chromatin immunoprecipitation assays revealed that, in the presence of HBx, Par14/Par17 were efficiently recruited to cccDNA and promoted transcriptional activation via specific DNA-binding residues (S19/44). In contrast, in the absence of HBx, Par14/Par17 bound cccDNA only at the basal level and did not promote transcriptional activation. Taken together, our results demonstrate that Par14 and Par17 upregulate HBV RNA transcription and DNA synthesis, thereby increasing the HBV cccDNA level, through formation of the cccDNA-Par14/17-HBx complex.IMPORTANCE The HBx protein plays an essential regulatory role in HBV replication. We found that substrate-binding residues on the human parvulin peptidylprolyl cis/trans isomerase proteins Par14 and Par17 bound to conserved arginine-proline (RP) motifs on HBx in the cytoplasm, nucleus, and mitochondria. The HBx-Par14/Par17 interaction stabilized HBx; promoted its translocation to the nucleus and mitochondria; and stimulated multiple steps of HBV replication, including cccDNA formation, HBV RNA and DNA synthesis, and virion secretion. In addition, in the presence of HBx, the Par14 and Par17 proteins bound to cccDNA and promoted its transcriptional activation. Our results suggest that inhibition or knockdown of Par14 and Par17 may represent a novel therapeutic option against HBV infection.


Assuntos
DNA Circular/metabolismo , Vírus da Hepatite B/genética , Vírus da Hepatite B/metabolismo , Hepatite B/metabolismo , Peptidilprolil Isomerase de Interação com NIMA/metabolismo , Transativadores/metabolismo , Replicação Viral/genética , Sequência de Aminoácidos , Linhagem Celular Tumoral , Núcleo Celular/genética , Núcleo Celular/metabolismo , Núcleo Celular/virologia , DNA Circular/genética , DNA Viral/genética , DNA Viral/metabolismo , Células HEK293 , Células Hep G2 , Hepatite B/virologia , Humanos , Mitocôndrias/genética , Mitocôndrias/metabolismo , Mitocôndrias/virologia , Ativação Transcricional/genética , Regulação para Cima/genética , Proteínas Virais Reguladoras e Acessórias , Vírion/genética , Vírion/metabolismo
5.
J Virol ; 92(21)2018 11 01.
Artigo em Inglês | MEDLINE | ID: mdl-30111572

RESUMO

Sirtuin 2 (Sirt2), a NAD+-dependent protein deacetylase, is overexpressed in many hepatocellular carcinomas (HCCs) and can deacetylate many proteins, including tubulins and AKT, prior to AKT activation. Here, we found that endogenous Sirt2 was upregulated in wild-type hepatitis B virus (HBV WT)-replicating cells, leading to tubulin deacetylation; however, this was not the case in HBV replication-deficient-mutant-transfected cells and 1.3-mer HBV WT-transfected and reverse transcriptase inhibitor (entecavir or lamivudine)-treated cells, but all HBV proteins were expressed. In HBV WT-replicating cells, upregulation of Sirt2 induced AKT activation, which consequently downregulated glycogen synthase kinase 3ß (GSK-3ß) and increased ß-catenin levels; however, downregulation of Sirt2 in HBV-nonreplicating cells impaired AKT/GSK-3ß/ß-catenin signaling. Overexpression of Sirt2 isoform 1 stimulated HBV transcription and consequently HBV DNA synthesis, which in turn activated AKT and consequently increased ß-catenin levels, possibly through physical interactions with Sirt2 and AKT. Knockdown of Sirt2 by short hairpin RNAs (shRNAs), inhibition by 2-cyano-3-[5-(2,5-dichlorophenyl)-2-furanyl]-N-5-quinolinyl-2-propenamide (AGK2), or dominant negative mutant expression inhibited HBV replication, reduced AKT activation, and decreased ß-catenin levels. Through HBV infection, we demonstrated that Sirt2 knockdown inhibited HBV replication from transcription. Although HBx itself activates AKT and upregulates ß-catenin, Sirt2-mediated signaling and upregulated HBV replication were HBx independent. Since constitutively active AKT inhibits HBV replication, the results suggest that upregulated Sirt2 and activated AKT may balance HBV replication to prolong viral replication, eventually leading to the development of HCC. Also, the results indicate that Sirt2 inhibition may be a new therapeutic option for controlling HBV infection and preventing HCC.IMPORTANCE Even though Sirt2, a NAD+-dependent protein deacetylase, is overexpressed in many HCCs, and overexpressed Sirt2 promotes hepatic fibrosis and associates positively with vascular invasion by primary HCCs through AKT/GSK-3ß/ß-catenin signaling, the relationship between Sirt2, HBV, HBx, and/or HBV-associated hepatocarcinogenesis is unclear. Here, we show that HBV DNA replication, not HBV expression, correlates positively with Sirt2 upregulation and AKT activation. We demonstrate that overexpression of Sirt2 further increases HBV replication, increases AKT activation, downregulates GSK-3ß, and increases ß-catenin levels. Conversely, inhibiting Sirt2 decreases HBV replication, reduces AKT activation, and decreases ß-catenin levels. Although HBx activates AKT to upregulate ß-catenin, Sirt2-mediated effects were not dependent on HBx. The results also indicate that a Sirt2 inhibitor may control HBV infection and prevent the development of hepatic fibrosis and HCC.


Assuntos
DNA Viral/biossíntese , Glicogênio Sintase Quinase 3 beta/metabolismo , Vírus da Hepatite B/genética , Hepatite B/genética , Proteínas Proto-Oncogênicas c-akt/metabolismo , RNA Viral/genética , Sirtuína 2/metabolismo , beta Catenina/metabolismo , DNA Viral/genética , Glicogênio Sintase Quinase 3 beta/genética , Células HEK293 , Células Hep G2 , Hepatite B/metabolismo , Hepatite B/virologia , Humanos , Isoformas de Proteínas , Proteínas Proto-Oncogênicas c-akt/genética , Transdução de Sinais , Sirtuína 2/genética , Transcrição Gênica , Ativação Transcricional , Replicação Viral , beta Catenina/genética
6.
Front Microbiol ; 14: 921653, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-36760500

RESUMO

Introduction: Human parvulin peptidyl prolyl cis/trans isomerases PIN1 and PIN4 play important roles in cell cycle progression, DNA binding, protein folding and chromatin remodeling, ribosome biogenesis, and tubulin polymerization. In this article, we found that endogenous PIN1 and PIN4 were upregulated in selected hepatocellular carcinoma (HCC) cell lines. Methods: In this study, we inhibited PIN1 and PIN4 via parvulin inhibitors (Juglone, PiB, ATRA, 6,7,4'-THIF, KPT6566, and EGCG). The native agarose gel electrophoresis (NAGE) immunoblotting analysis revealed that upon PIN1 and/ or PIN4 inhibition, the HBc protein expression and core particle or capsid synthesis reduced remarkably. The effects of PIN4 inhibition on hepatitis B virus (HBV) replication were more pronounced as compared to that of PIN1. The Northern and Southern blotting revealed reduced HBV RNA and DNA levels. Results: During the HBV course of infection, Juglone, PiB, ATRA, 6,7,4'-THIF, KPT6566, and EGCG-mediated inhibition of PIN1 and PIN4 significantly lowered HBV transcriptional activities without affecting total levels of covalently closed circular DNA (cccDNA). Similar to the inhibitory effects of PIN1 and PIN4 on HBV replication, the knockdown of PIN1 and PIN4 in HBV infection cells revealed significantly reduced amounts of intracellular HBc, HBs, HBV pgRNA, SmRNAs, core particles, and HBV DNA synthesis. Similarly, PIN1 and PIN4 KD abrogated extracellular virion release, naked capsid levels, and HBV DNA levels. In comparison with PIN1 KD, the PIN4 KD showed reduced HBc and/or core particle stabilities, indicating that PIN4 is more critically involved in HBV replication. Chromatin immunoprecipitation (ChIP) assays revealed that in contrast to DNA binding PIN4 proteins, the PIN1 did not show binding to cccDNA. Similarly, upon PIN1 KD, the HBc recruitment to cccDNA remained unaffected. However, PIN4 KD significantly abrogated PIN4 binding to cccDNA, followed by HBc recruitment to cccDNA and restricted HBV transcriptional activities. These effects were more pronounced in PIN4 KD cells upon drug treatment in HBV-infected cells. Conclusion: The comparative analysis revealed that in contrast to PIN1, PIN4 is more critically involved in enhancing HBV replication. Thus, PIN1 and PIN4 inhibition or knockdown might be novel therapeutic targets to suppress HBV infection. targets to suppress HBV infection.

7.
J Cancer Res Ther ; 19(7): 1870-1879, 2023 Oct 01.
Artigo em Inglês | MEDLINE | ID: mdl-38376291

RESUMO

BACKGROUND: LRIG1 belongs to the family of transmembrane proteins containing leucine-rich repeats. LRIGs are considered as tumor suppressors as they negatively regulate receptor tyrosine kinases. The role of LRIG1 as an EGFR regulator makes it an important marker to be studied in various epithelial-derived cancers. METHODS: LRIG1 expression was determined in Erbb2 + cell lines by western blotting, and cell motility was examined by cell migration assay. The AKT/GSK3-ß/ß-catenin pathway was determined in the presence of LRIG1 and Erbb2 by using western blotting. RESULTS: So far, no study has reported the expression of LRIG1 in benign forms of tumor such as fibroadenoma. The current study aims to analyze LRIG1 expression in fibroadenoma and invasive ductal carcinoma (IDC) tissues. In this study, we compared the LRIG1 expression with different clinicopathological parameters of patients having IDC or fibroadenoma. LRIG1 expression was low in Erbb2+ cell lines, and more cell motility was observed. The AKT/GSK3-ß/ß-catenin pathway was activated when LRIG1 was downregulated; consequently, Erbb2 was upregulated. Our results indicated that LRIG1 expression can be significantly correlated with age, Nottingham index, and Her2/neu status of cancer. The expression of LRIG1 in IDC and fibroadenoma were found to be significantly different. CONCLUSION: The fibroadenoma tissue sections were found to express LRIG1 more intensely as compared to the IDC sections, which are in line with the studies reporting reduced copy number of the gene either due to gene deletion or transcriptional inhibition. This further supports that the downregulation of LRIG1 may lead to malignant tumor acting as a tumor suppressor.


Assuntos
Neoplasias da Mama , Carcinoma Ductal , Fibroadenoma , Glicoproteínas de Membrana , Feminino , Humanos , beta Catenina , Neoplasias da Mama/genética , Fibroadenoma/genética , Quinase 3 da Glicogênio Sintase , Domínios de Imunoglobulina , Leucina , Glicoproteínas de Membrana/genética , Prognóstico , Proteínas Proto-Oncogênicas c-akt
8.
Front Cell Infect Microbiol ; 13: 1234903, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-38239506

RESUMO

The human sirtuin 2 gene (SIRT2) encodes a full-length Sirt2 protein (i.e., the Sirt2 isoform 1), which primarily functions as a cytoplasmic α-tubulin deacetylase, and which promotes the growth of hepatocellular carcinoma (HCC). Hepatitis B virus (HBV) replication itself, or HBV X (HBx) protein-mediated transcriptional transactivation, enhances Sirt2.1 expression; therefore, Sirt2.1 itself is capable of positively increasing HBV transcription and replication. Sirt2.1 is linked to liver fibrosis and epithelial-to-mesenchymal transition and, consequently, augments the risk of HCC. The Sirt2.1 protein enhances the HBV replication cycle by activating the AKT/glycogen synthase kinase 3 beta (GSK3ß)/ß-catenin pathway. It also activates the transcription of the viral enhancer I/HBx promoter (EnI/Xp) and enhancer II/HBc promoter (EnII/Cp) by targeting the transcription factor p53. The Sirt2 isoform 2 (Sirt2.2) is mainly localized in the cytoplasm, and the N-terminus is shorter by 37 amino acids than that of Sirt2.1. Despite the truncation of the N-terminal region, Sirt2.2 is still capable of enhancing HBV replication and activating the AKT/GSK3ß/ß-catenin signaling pathway. The Sirt2 isoform 5 (Sirt2.5) is primarily localized to the nucleus, it lacks a nuclear export signal (NES), and the catalytic domain (CD) is truncated. Upon HBV replication, expression of the Sirt2 isoforms is also enhanced, which further upregulates the HBV replication, and, therefore, supports the vicious cycle of viral replication and progression of the disease. Sirt2 diversely affects HBV replication such that its isoform 1 intensely augments HBV replication and isoform 2 (despite of the truncated N-terminal region) moderately enhances HBV replication. Isoform 5, on the other hand, tends to protect the cell (for smooth long-term continued viral replication) from HBV-induced extreme damage or death via a discrete set of regulatory mechanisms impeding viral mRNAs, the hepatitis B core/capsid protein (HBc), core particles, replicative intermediate (RI) DNAs, and covalently closed circular DNA (cccDNA) levels, and, consequently, limiting HBV replication. In contrast to Sirt2.1 and Sirt 2.2, the Sirt2.5-mediated HBV replication is independent of the AKT/GSK3ß/ß-catenin signaling cascade. Sirt2.5 is recruited more at cccDNA than the recruitment of Sirt2.1 onto the cccDNA. This recruitment causes the deposition of more histone lysine methyltransferases (HKMTs), including SETDB1, SUV39H1, EZH2, and PR-Set7, along with the respective corresponding transcriptional repressive markers such as H3K9me3, H3K27me3, and H4K20me1 onto the HBV cccDNA. In HBV-replicating cells, Sirt2.5 can also make complexes with PR-Set7 and SETDB1. In addition, Sirt2.5 has the ability to turn off transcription from cccDNA through epigenetic modification via either direct or indirect interaction with HKMTs.


Assuntos
Carcinoma Hepatocelular , Hepatite B , Neoplasias Hepáticas , Humanos , beta Catenina/metabolismo , DNA Circular/metabolismo , DNA Viral/genética , Glicogênio Sintase Quinase 3 beta/metabolismo , Vírus da Hepatite B/fisiologia , Isoformas de Proteínas/metabolismo , Proteínas Proto-Oncogênicas c-akt/metabolismo , Sirtuína 2/genética , Sirtuína 2/metabolismo , Replicação Viral/fisiologia
9.
Microorganisms ; 11(12)2023 Nov 21.
Artigo em Inglês | MEDLINE | ID: mdl-38137971

RESUMO

The Hepatitis B virus (HBV) HBx and HBc proteins play a crucial role in associating with covalently closed circular DNA (cccDNA), the primary factor contributing to intrahepatic viral persistence and a major obstacle in achieving a cure for HBV. The cccDNA serves as a reservoir for viral persistence. Targeting the viral HBc and HBx proteins' interaction with cccDNA could potentially limit HBV replication. In this study, we present epitopes identified from global consensus sequences of HBx and HBc proteins that have the potential to serve as targets for the development of effective vaccine candidates. Furthermore, conserved residues identified through this analysis can be utilized in designing novel, site-specific anti-HBV agents capable of targeting all major genotypes of HBV. Our approach involved designing global consensus sequences for HBx and HBc proteins, enabling the analysis of variable regions and highly conserved motifs. These identified motifs and regions offer potent sites for the development of peptide vaccines, the design of site-specific RNA interference, and the creation of anti-HBV inhibitors. The epitopes derived from global consensus sequences of HBx and HBc proteins emerge as promising targets for the development of effective vaccine candidates. Additionally, the conserved residues identified provide valuable insights for the development of innovative, site-specific anti-HBV agents capable of targeting all major genotypes of HBV from A to J.

10.
Future Microbiol ; 18: 1265-1277, 2023 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-37882773

RESUMO

Background: We determined the prevalence of antimicrobial resistance (AMR) in polymicrobial pathogens in Pakistan. Methods: A total of 70,518 clinical samples were collected aseptically and confirmation of isolates and antibiogram were performed by the VITEK 2 system. Results: Of 70,518 samples, 441 (0.62%) were polymicrobial samples, with 882 (1.2%) polymicrobial pathogens with 689 (78.1%) Gram-negative rods (GNRs), 166 (18.8%) Gram-positive cocci and 27 (3.1%) Candida albicans. Among GNRs, 28.8% were Escherichia coli and 25.9% were Klebsiella pneumoniae. Majority, 15.1% of Pseudomonas aeruginosa and K. pneumoniae were found in combination. 30.1% of isolates were ESBL producers, 9.7% carbapenem-resistant organisms, 35.5% MRSA and 6.0% VRE. 100% of E. coli were resistant to ampicillin and 98% of K. pneumoniae were resistant to piperacillin. Conclusion: A high prevalence of AMR in polymicrobial pathogens was observed.


Infections caused by one or more types of bacteria, viruses, fungi or parasites ­ known as polymicrobial infections ­ are a threat to health. These infections cause serious illness and are linked to high numbers of deaths, long hospital stays and high costs of treatment. Usually, polymicrobial infections are treated with combinations of antimicrobials. However, microbes becoming less susceptible to antimicrobials (known as antimicrobial resistance) is an increasing problem. To find out how common resistance is in Pakistan, this study tested 70,518 clinical samples. Of these, 441 tested positive for polymicrobial infections. These included Candida albicans, Gram-positive cocci and Gram-negative rods infections. Many of these were resistant to widely used antibiotics such as penicillins, cephalosporins, quinolones and fluoroquinolones. This study concluded that hospitals in Pakistan have a high prevalence of resistance and that better cleanliness practices should be put in place to combat this.


Assuntos
Antibacterianos , Coinfecção , Humanos , Antibacterianos/farmacologia , Antibacterianos/uso terapêutico , Estudos Retrospectivos , Escherichia coli , Paquistão/epidemiologia , Coinfecção/epidemiologia , Coinfecção/tratamento farmacológico , Bactérias Gram-Negativas , Testes de Sensibilidade Microbiana
11.
Front Microbiol ; 14: 1270018, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-38098671

RESUMO

The efficacy of antibiotics and other antimicrobial agents in combating bacterial infections faces a grave peril in the form of antimicrobial resistance (AMR), an exceedingly pressing global health issue. The emergence and dissemination of drug-resistant bacteria can be attributed to the rampant overuse and misuse of antibiotics, leading to dire consequences such as organ failure and sepsis. Beyond the realm of individual health, the pervasive specter of AMR casts its ominous shadow upon the economy and society at large, resulting in protracted hospital stays, elevated medical expenditures, and diminished productivity, with particularly dire consequences for vulnerable populations. It is abundantly clear that addressing this ominous threat necessitates a concerted international endeavor encompassing the optimization of antibiotic deployment, the pursuit of novel antimicrobial compounds and therapeutic strategies, the enhancement of surveillance and monitoring of resistant bacterial strains, and the assurance of universal access to efficacious treatments. In the ongoing struggle against this encroaching menace, phage-based therapies, strategically tailored to combat AMR, offer a formidable line of defense. Furthermore, an alluring pathway forward for the development of vaccines lies in the utilization of virus-like particles (VLPs), which have demonstrated their remarkable capacity to elicit a robust immune response against bacterial infections. VLP-based vaccinations, characterized by their absence of genetic material and non-infectious nature, present a markedly safer and more stable alternative to conventional immunization protocols. Encouragingly, preclinical investigations have yielded promising results in the development of VLP vaccines targeting pivotal bacteria implicated in the AMR crisis, including Salmonella, Escherichia coli, and Clostridium difficile. Notwithstanding the undeniable potential of VLP vaccines, formidable challenges persist, including the identification of suitable bacterial markers for vaccination and the formidable prospect of bacterial pathogens evolving mechanisms to thwart the immune response. Nonetheless, the prospect of VLP-based vaccines holds great promise in the relentless fight against AMR, underscoring the need for sustained research and development endeavors. In the quest to marshal more potent defenses against AMR and to pave the way for visionary innovations, cutting-edge techniques that incorporate RNA interference, nanomedicine, and the integration of artificial intelligence are currently under rigorous scrutiny.

12.
Front Med (Lausanne) ; 9: 902611, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-35899213

RESUMO

Achromobacter xylosoxidans, previously identified as Alcaligenes xylosoxidans, is a rod-shaped, flagellated, non-fermenting Gram-negative bacterium that has the ability to cause diverse infections in humans. As a part of its intrinsic resistance to different antibiotics, Achromobacter spp. is also increasingly becoming resistant to Carbapenems. Lack of knowledge regarding the pathogen's clinical features has led to limited efforts to develop countermeasures against infection. The current study utilized an immunoinformatic method to map antigenic epitopes (Helper T cells, B-cell and Cytotoxic-T cells) to design a vaccine construct. We found that 20 different epitopes contribute significantly to immune response instigation that was further supported by physicochemical analysis and experimental viability. The safety profile of our vaccine was tested for antigenicity, allergenicity, and toxicity against all the identified epitopes before they were used as vaccine candidates. The disulfide engineering was carried out in an area of high mobility to increase the stability of vaccine proteins. In order to determine if the constructed vaccine is compatible with toll-like receptor, the binding affinity of vaccine was investigated via molecular docking approach. With the in silico expression in host cells and subsequent immune simulations, we were able to detect the induction of both arms of the immune response, i.e., humoral response and cytokine induced response. To demonstrate its safety and efficacy, further experimental research is necessary.

13.
Front Cell Infect Microbiol ; 12: 726263, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-36189356

RESUMO

Background: Coronavirus disease 2019 (COVID-19) is caused by severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2), which is resilient, highly pathogenic, and rapidly transmissible. COVID-19 patients have been reported to have underlying chronic liver abnormalities linked to hepatic dysfunction. Discussion: Viral RNAs are detectable in fecal samples by RT-PCR even after negative respiratory samples, which suggests that SARS-CoV-2 can affect the gastrointestinal tract and the liver. The case fatality rates are higher among the elderly and those with underlying comorbidities such as hypertension, diabetes, liver abnormality, and heart disease. There is insufficient research on signaling pathways. Identification of molecular mechanisms involved in SARS-CoV-2-induced damages to hepatocytes is challenging. Herein, we demonstrated the multifactorial effects of SARS-CoV-2 on liver injury such as psychological stress, immunopathogenesis, systemic inflammation, ischemia and hypoxia, drug toxicity, antibody-dependent enhancement (ADE) of infection, and several others which can significantly damage the liver. Conclusion: During the COVID-19 pandemic, it is necessary for clinicians across the globe to pay attention to SARS-CoV-2-mediated liver injury to manage the rising burden of hepatocellular carcinoma. To face the challenges during the resumption of clinical services for patients with pre-existing liver abnormalities and HCC, the impact of SARS-CoV-2 on hepatocytes should be investigated both in vitro and in vivo.


Assuntos
COVID-19 , Carcinoma Hepatocelular , Gastroenteropatias , Neoplasias Hepáticas , Idoso , COVID-19/complicações , Humanos , Fígado/patologia , Neoplasias Hepáticas/patologia , Pandemias , SARS-CoV-2
14.
Front Microbiol ; 12: 795047, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34970249

RESUMO

We recently reported that the PPIase Par14 and Par17 encoded by PIN4 upregulate HBV replication in an HBx-dependent manner by binding to conserved arginine-proline (RP) motifs of HBx. HBV core protein (HBc) has a conserved 133RP134 motif; therefore, we investigated whether Par14/Par17 bind to HBc and/or core particles. Native agarose gel electrophoresis (NAGE) and immunoblotting and co-immunoprecipitation were used. Chromatin immunoprecipitation from HBV-infected HepG2-hNTCP-C9 cells was performed. NAGE and immunoblotting revealed that Par14/Par17 bound to core particles and co-immunoprecipitation revealed that Par14/Par17 interacted with core particle assembly-defective, and dimer-positive HBc-Y132A. Thus, core particles and HBc interact with Par14/Par17. Par14/Par17 interacted with the HBc 133RP134 motif possibly via substrate-binding E46/D74 and E71/D99 motifs. Although Par14/Par17 dissociated from core particles upon heat treatment, they were detected in 0.2 N NaOH-treated opened-up core particles, demonstrating that Par14/Par17 bind outside and inside core particles. Furthermore, these interactions enhanced the stabilities of HBc and core particles. Like HBc-Y132A, HBc-R133D and HBc-R133E were core particle assembly-defective and dimer-positive, demonstrating that a negatively charged residue at position 133 cannot be tolerated for particle assembly. Although positively charged R133 is solely important for Par14/17 interactions, the 133RP134 motif is important for efficient HBV replication. Chromatin immunoprecipitation from HBV-infected cells revealed that the S19 and E46/D74 residues of Par14 and S44 and E71/D99 residues of Par17 were involved in recruitment of 133RP134 motif-containing HBc into cccDNA. Our results demonstrate that interactions of HBc, Par14/Par17, and cccDNA in the nucleus and core particle-Par14/Par17 interactions in the cytoplasm are important for HBV replication.

16.
Clin Cancer Res ; 24(19): 4771-4784, 2018 10 01.
Artigo em Inglês | MEDLINE | ID: mdl-29563139

RESUMO

Purpose: Telomerase promoter mutations are highly prevalent in human tumors including melanoma. A subset of patients with metastatic melanoma often fail multiple therapies, and there is an unmet and urgent need to prolong disease control for those patients.Experimental Design: Numerous preclinical therapy-resistant models of human and mouse melanoma were used to test the efficacy of a telomerase-directed nucleoside, 6-thio-2'-deoxyguanosine (6-thio-dG). Integrated transcriptomics and proteomics approaches were used to identify genes and proteins that were significantly downregulated by 6-thio-dG.Results: We demonstrated the superior efficacy of 6-thio-dG both in vitro and in vivo that results in telomere dysfunction, leading to apoptosis and cell death in various preclinical models of therapy-resistant melanoma cells. 6-thio-dG concomitantly induces telomere dysfunction and inhibits the expression level of AXL.Conclusions: In summary, this study shows that indirectly targeting aberrant telomerase in melanoma cells with 6-thio-dG is a viable therapeutic approach in prolonging disease control and overcoming therapy resistance. Clin Cancer Res; 24(19); 4771-84. ©2018 AACR See related commentary by Teh and Aplin, p. 4629.


Assuntos
Desoxiguanosina/análogos & derivados , Melanoma/tratamento farmacológico , Regiões Promotoras Genéticas/genética , Telomerase/genética , Tionucleosídeos/farmacologia , Animais , Linhagem Celular Tumoral , Desoxiguanosina/farmacologia , Resistencia a Medicamentos Antineoplásicos/efeitos dos fármacos , Humanos , Melanoma/genética , Melanoma/patologia , Camundongos , Mutação , Telômero/efeitos dos fármacos , Telômero/genética
17.
Radiol Case Rep ; 12(1): 13-18, 2017 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-28228869

RESUMO

The right vertebral artery most commonly originates as the first branch of the right subclavian artery. Although anatomical variants of the aortic arch are commonly encountered on cross-sectional imaging, certain variants of the right vertebral artery are exceedingly rare. In this report, we present 3 cases of aberrant right vertebral artery arising as the last branch of the aortic arch, a very rare variant.

18.
World J Virol ; 5(2): 82-4, 2016 May 12.
Artigo em Inglês | MEDLINE | ID: mdl-27175353

RESUMO

Pakistan is a developing country that has a population of 190 million people and faces a huge burden of viral diseases. Every year during monsoon season heavy rain fall and lack of disaster management skills potentially increase the transmission of waterborne diseases, vector borne diseases and viral outbreaks. Due to severe flooding, thousands of people lose their lives and millions are displaced each year. In most of the cases the children who lose their family members are forced into illegal professions of begging, child labor and prostitution which make them prone to sexually transmitted infections. Up to date, no scientific study has been conducted nationwide to illustrate epidemiological patterns of waterborne diseases, vector borne diseases and viral epidemics during flash flood. Mosquito sprays would not be a sufficient approach for dengue eradication; mass awareness, larvicide and biological control by Guppy fishes are also effective strategies to overcome dengue problem. International health bodies and non-governmental organizations must take note of this alerting situation and take adequate steps such as financial/medical aid in order to defeat the after-effects of flood.

20.
Jundishapur J Microbiol ; 8(1): e13348, 2015 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-25763131

RESUMO

BACKGROUND: Toll-like receptors (TLRs) play a major role in innate immunity, since they detect conserved pathogen-associated molecular patterns (PAMPs) on a range of microbes, including viruses, leading to innate immune activation and orchestration of the adaptive immune response. OBJECTIVES: The current study aimed to discuss earlier evidence implicating TLRs I and II in the innate immune response to viruses, in the light of more recent clinical data demonstrating that TLRs are important for anti-viral immunity in humans. MATERIALS AND METHODS: A literature search was performed via accessing research articles from PakMediNet, Pubmed and Google Scholar with key words of Toll-like receptors I and II Regarding human viral pathogenesis. The valued information on the recent scientific horizons was subjected to critical analysis. RESULTS: Comprehensive literature review illustrates important signaling pathways involved in TLR1/TLR2 mediated regulation of viral pathogenesis. TLRs mediated activation of apoptosis tends to contribute towards defense strategies utilized by innate immune response. Activation of antiviral TLR1-dependent signaling cascade would ultimately lead to activation of NF-kappa B which promotes antiviral responses via induction of specific genes. TLR1/TLR2 dimer generates intracellular signaling via IRAK4 mediated activation of IRAK1/2 which results in activation of NF-kappa B, p38 and JNK proteins in cytoplasm. NF- kappa B, p38 and JNK enter the nucleus thereby causing activation of various pro-inflammatory cytokines such as IL-1 beta, TNF-alpha, IL-6, IL-8 and IL-18. Among the chronic HCV infection, the HCV core protein induces TNF-α and IL-10 from the macrophages thereby causing reduction in release of interferon alpha. Abnormal TLR1/TLR2 signaling may contribute to the enhancement of infection-related morbidity and mortality. CONCLUSIONS: To date, a large number of viruses are proved to trigger innate immunity via TLRs, suggesting that these receptors are likely to be important in the outcome of viral infection. This suggestion is supported by the observation that many viruses have evolved mechanisms not only to evade the innate immune system, but also to subvert it for the benefit of the virus.

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