Quercetin-Rich Ethanolic Extract of Polygonum odoratum var Pakphai Leaves Decreased Gene Expression and Secretion of Pro-Inflammatory Mediators in Lipopolysaccharide-Induced Murine RAW264.7 Macrophages.

Polygonum odoratum var. Pakphai has been used in traditional Thai medicine for the treatment of flatulence and constipation and to relieve the inflammation caused by insect bites. Quercetin (Q), which is abundant in plant-based foods, has been found to exert anti-inflammatory properties. This study evaluated the anti-inflammatory activity of P. odoratum ethanolic extract in RAW264.7 macrophage cells. Leaves were extracted with 50% ethanol, phenolics and flavonoids were then analyzed using UHPLC-QTOF-MS and HPLC-DAD. RAW264.7 cells were induced with lipopolysaccharides (LPSs). They were then treated with the extract and prostaglandin E2 (PGE2), and interleukin-6 (IL-6) and tumor necrotic factor-alpha (TNF-α) concentrations were determined. Levels of cyclooxygenase-2 (COX-2), inducible nitric oxide synthase (iNOS), IL-6 and TNF-α mRNAs were analyzed using qRT-PCR. Chemical analysis demonstrated that the extract was abundant with Q while also containing catechin, gallic acid, epicatechin gallate and coumarin. The extract increased the viability of RAW264.7 cells and dose-dependently decreased nitric oxide production, PGE2, IL-6 and TNF-α levels in the medium from the LPS-induced RAW264.7 cell culture. Consistently, COX-2, iNOS, IL-6 and TNF-α mRNA levels were decreased in a concentration-dependent manner (p < 0.05). Thus, the quercetin-rich ethanolic extract derived from P. odoratum var Pakphai leaves can exert anti-inflammatory activity in LPS-induced RAW264.7 cells through a reduction of the pro-inflammatory mediator response.

EFTUD2 Is a Novel Innate Immune Regulator Restricting Hepatitis C Virus Infection through the RIG-I/MDA5 Pathway.

UNLABELLED: The elongation factor Tu GTP binding domain-containing protein 2 (EFTUD2) was identified as an anti-hepatitis C virus (HCV) host factor in our recent genome-wide small interfering RNA (siRNA) screen. In this study, we sought to further determine EFTUD2's role in HCV infection and investigate the interaction between EFTUD2 and other regulators involved in HCV innate immune (RIG-I, MDA5, TBK1, and IRF3) and JAK-STAT1 pathways. We found that HCV infection decreased the expression of EFTUD2 and the viral RNA sensors RIG-I and MDA5 in HCV-infected Huh7 and Huh7.5.1 cells and in liver tissue from in HCV-infected patients, suggesting that HCV infection downregulated EFTUD2 expression to circumvent the innate immune response. EFTUD2 inhibited HCV infection by inducing expression of the interferon (IFN)-stimulated genes (ISGs) in Huh7 cells. However, its impact on HCV infection was absent in both RIG-I knockdown Huh7 cells and RIG-I-defective Huh7.5.1 cells, indicating that the antiviral effect of EFTUD2 is dependent on RIG-I. Furthermore, EFTUD2 upregulated the expression of the RIG-I-like receptors (RLRs) RIG-I and MDA5 to enhance the innate immune response by gene splicing. Functional experiments revealed that EFTUD2-induced expression of ISGs was mediated through interaction of the EFTUD2 downstream regulators RIG-I, MDA5, TBK1, and IRF3. Interestingly, the EFTUD2-induced antiviral effect was independent of the classical IFN-induced JAK-STAT pathway. Our data demonstrate that EFTUD2 restricts HCV infection mainly through an RIG-I/MDA5-mediated, JAK-STAT-independent pathway, thereby revealing the participation of EFTUD2 as a novel innate immune regulator and suggesting a potentially targetable antiviral pathway. IMPORTANCE: Innate immunity is the first line defense against HCV and determines the outcome of HCV infection. Based on a recent high-throughput whole-genome siRNA library screen revealing a network of host factors mediating antiviral effects against HCV, we identified EFTUD2 as a novel innate immune regulator against HCV in the infectious HCV cell culture model and confirmed that its expression in HCV-infected liver tissue is inversely related to HCV infection. Furthermore, we determined that EFTUD2 exerts its antiviral activity mainly through governing its downstream regulators RIG-I and MDA5 by gene splicing to activate IRF3 and induce classical ISG expression independent of the JAT-STAT signaling pathway. This study broadens our understanding of the HCV innate immune response and provides a possible new antiviral strategy targeting this novel regulator of the innate response.

Kinetic differences in the induction of interferon stimulated genes by interferon-α and interleukin 28B are altered by infection with hepatitis C virus.

UNLABELLED: Several genome-wide association studies (GWAS) have identified a genetic polymorphism associated with the gene locus for interleukin 28B (IL28B), a type III interferon (IFN), as a major predictor of clinical outcome in hepatitis C. Antiviral effects of the type III IFN family have previously been shown against several viruses, including hepatitis C virus (HCV), and resemble the function of type I IFN including utilization of the intracellular Janus kinase signal transducer and activator of transcription (JAK-STAT) pathway. Effects unique to IL28B that would distinguish it from IFN-α are not well defined. By analyzing the transcriptomes of primary human hepatocytes (PHH) treated with IFN-α or IL28B, we sought to identify functional differences between IFN-α and IL28B to better understand the roles of these cytokines in the innate immune response. Although our data did not reveal distinct gene signatures, we detected striking kinetic differences between IFN-α and IL28B stimulation for interferon stimulated genes (ISGs). While gene induction was rapid and peaked at 8 hours of stimulation with IFN-α in PHH, IL28B produced a slower, but more sustained increase in gene expression. We confirmed these findings in the human hepatoma cell line Huh7.5.1. Interestingly, in HCV-infected cells the rapid response after stimulation with IFN-α was blunted, and the induction pattern resembled that caused by IL28B. CONCLUSION: The kinetics of gene induction are fundamentally different for stimulations with either IFN-α or IL28B in hepatocytes, suggesting distinct roles of these cytokines within the immune response. Furthermore, the observed differences are substantially altered by infection with HCV.

Hepatitis C virus genotypes circulating in patients with chronic hepatitis C in Thailand and their responses to combined PEG-IFN and RBV therapy.

Different genotypes of hepatitis C virus (HCV) are circulating in different areas of the world. In Thailand, distribution of HCV genotypes has been investigated mostly in the central area while the information in other regions is limited. This study aimed to determine the HCV genotypes circulating in chronic hepatitis C patients in Chiang Mai, Thailand and to investigate the response of different HCV genotypes to pegylated interferon (PEG-IFN) and ribavirin (RBV) treatment. Patients infected chronically with HCV were treated with PEG-IFN/RBV based on the standard regimens for each HCV genotype and followed up the patients until the end of treatment and 6 months afterward. Out of 158 patients, three major HCV genotypes and eight subtypes were identified. Genotype 3 was the most predominant at 54.5%, followed by genotypes 1 (31%) and 6 (14.5%). Among subtypes, 3a was the most prevalent subtype (45%), followed by 1b (18.4%), 1a and 6f (each at 12.6%), 3b (9.5%), and 6a, 6i, 6n (each at 0.63%). Patients with genotype 3 showed higher rate of responding to the treatment at 80.2% compared to genotypes 1 (73.5%) and 6f (65%). Additionally, patients with genotype 6f showed higher rate of relapsing (25%) compared to genotypes 1 and 3 (14.3% and 16.3%, respectively). In conclusion, this study reported multiple HCV genotypes circulated in Thai patients and the response of different HCV genotypes to PEG-IFN/RBV treatment.

Anti-inflammatory potential of a Thai traditional remedy called Prabchompoothaweep in an animal model of acute and sub-acute inflammation.

ETHNOPHARMACOLOGICAL RELEVANCE: Prabchompoothaweep (PCT) is a Thai remedy which is composed of 23 herbs and has been added onto the National List of Essential Medicines (NLEM) of Thailand. This remedy has been used to treat allergic rhinitis and asthma in Thai traditional medicine for many years. Furthermore, a few studies have reported anti-allergic, anti-malarial, anti-inflammatory and antioxidant activities. AIM OF THE STUDY: This study aims to evaluate anti-inflammatory activity of PCT extract in an animal model. MATERIALS AND METHODS: The animal model of acute inflammation was studied over a 24-h period, utilizing the method of carrageenan-induced paw oedema. In addition, sub-acute inflammation was examined over 7 days, using the formalin-induced paw oedema method. The treatment groups received PCT extracts, via the oral route, at 1-h prior to injection and then the sub plantar of the rat right paw was injected with the named substances to generate paw oedema. The paw thickness was measured by vernier caliper at regular intervals after injection. At the end of experiment, the blood and paw tissues were collected for measurement of pro-inflammatory cytokines and histological examination respectively. RESULTS: In acute inflammation, all doses of PCT extract (250, 500 and 1000 mg/kg p.o.) significantly reduced paw thickness after the first 3 h in a dose-dependent manner and the percentage of inhibition was 38.7%, 47.8% and 49.5% respectively. The pro-inflammatory cytokines, including TNF-α and IL-1ß, statistically decreased with all doses of the extracts. However, the histological examination did not reveal significant results due to the short time duration. As regards to sub-acute inflammation, all doses of PCT extract significantly reduced paw thickness with 12.78%, 23.64% and 35.78%, in a dose dependent manner. Also, the pro-inflammatory cytokines (TNF-α and IL-1ß) significantly decreased at day 7. Interestingly, the histological examination of paw tissue demonstrated reductions of mononuclear infiltrations of inflammatory cells, this was observed in the group receiving PCT extracts, also in a dose-dependent manner. CONCLUSION: Therefore, PCT exerted anti-inflammatory activity in an animal model of acute and sub-acute inflammation, suggesting that it could be used as a new source for treatment of inflammatory diseases.

Hepatitis C virus NS5A disrupts STAT1 phosphorylation and suppresses type I interferon signaling.

Responses to alpha interferon (IFN-α)-based treatment are dependent on both host and viral factors and vary markedly among patients infected with different hepatitis C virus (HCV) genotypes (GTs). Patients infected with GT3 viruses consistently respond better to IFN treatment than do patients infected with GT1 viruses. The mechanisms underlying this difference are not well understood. In this study, we sought to determine the effects of HCV NS5A proteins from different genotypes on IFN signaling. We found that the overexpression of either GT1 or GT3 NS5A proteins significantly inhibited IFN-induced IFN-stimulated response element (ISRE) signaling, phosphorylated STAT1 (P-STAT1) levels, and IFN-stimulated gene (ISG) expression compared to controls. GT1 NS5A protein expression exhibited stronger inhibitory effects on IFN signaling than did GT3 NS5A protein expression. Furthermore, GT1 NS5A bound to STAT1 with a higher affinity than did GT3 NS5A. Domain mapping revealed that the C-terminal region of NS5A conferred these inhibitory effects on IFN signaling. The overexpression of HCV NS5A increased HCV replication levels in JFH1-infected cells through the further reduction of levels of P-STAT1, ISRE signaling, and downstream ISG responses. We demonstrated that the overexpression of GT1 NS5A proteins resulted in less IFN responsiveness than did the expression of GT3 NS5A proteins through stronger binding to STAT1. We confirmed that GT1 NS5A proteins exerted stronger IFN signaling inhibition than did GT3 NS5A proteins in an infectious recombinant JFH1 virus. The potent antiviral NS5A inhibitor BMS-790052 did not block NS5A-mediated IFN signaling suppression in an overexpression model, suggesting that NS5A's contributions to replication are independent of its subversive action on IFN. We propose a model in which the binding of the C-terminal region of NS5A to STAT1 leads to decreased levels of P-STAT1, ISRE signaling, and ISG transcription and, ultimately, to preferential GT1 resistance to IFN treatment.

Detection and characterization of ESBL-producing Escherichia coli and additional co-existence with mcr genes from river water in northern Thailand.

Background: Extended-spectrum ß-lactamase producing Escherichia coli (ESBL-producing E. coli) have emerged, causing human and animal infections worldwide. This study was conducted to investigate the prevalence and molecular genetic features of ESBL-producing and multidrug-resistant (MDR) E. coli in river water. Methods: A total of 172 E. coli samples were collected from the Kok River and Kham River in Chiang Rai, Thailand, during a 10-month period (2020-2021). Results: We detected 45.3% of E. coli to be MDR. The prevalence of ESBL-producers was 22%. Among those ESBL-producing strains, CTX-M-15 (44.7%) was predominantly found, followed by CTX-M-55 (26.3%), CTX-M-14 (18.4%), and CTX-M-27 (10.5%). The bla TEM-1 and bla TEM-116 genes were found to be co-harbored with the bla CTX-M genes. Mobile elements, i.e., ISEcp1 and Tn3, were observed. Twelve plasmid replicons were found, predominantly being IncF (76.3%) and IncFIB (52.6%). Whole genome sequencing of ten selected isolates revealed the co-existence of ESBL with mcr genes in two ESBL-producing E. coli. A wide diversity of MLST classifications was observed. An mcr-1.1-pap2 gene cassette was found to disrupt the PUF2806 domain-containing gene, while an mcr-3.4 contig on another isolate contained the nimC/nimA-mcr-3.4-dgkA core segment. Discussion: In conclusion, our data provides compelling evidence of MDR and ESBL-producing E. coli, co-existing with mcr genes in river water in northern Thailand, which may be disseminated into other environments and so cause increased risks to public health.

Analysis of mutations in the core and NS5A genes of hepatitis C virus in non-responder and relapser patients after treatment with Peg-IFN-α and ribavirin.

Mutations in several regions of HCV genome are shown to correlate with response to interferon (IFN) treatment. Persistence of HCV infection and poor susceptibility to treatment might be contributed by mutations arising within HCV genome which enable the virus to escape from host immune response/IFN treatment. This study investigated mutations in core and NS5A genes of HCV from non-responder and relapser patients after treatment with Peg-IFN-α and ribavirin. Viral RNA was extracted from patient sera and core and NS5A genes were amplified by RT-PCR. Nucleotide sequences of the core and NS5A genes were determined by direct sequencing, and converted to amino acid sequences. Nucleotide and amino acid sequences in the core region, ISDR, PKRBD, and V3 regions within NS5A after treatment were highly conserved when comparing to their corresponding sequences obtained before treatment. Interestingly, when comparing the virus from relapsers to those from non-responders, the number of mutations after treatment in N-terminal region of NS5A of virus from relapsers was significantly higher than those from non-responders (P < 0.05). Amino acid mutations at the N-terminus of NS5A of the virus in relapsers might help the virus to survive and somehow relapse after the cessation of the treatment.

HCV induces transforming growth factor ß1 through activation of endoplasmic reticulum stress and the unfolded protein response.

HCV replication disrupts normal endoplasmic reticulum (ER) function and activates a signaling network called the unfolded protein response (UPR). UPR is directed by three ER transmembrane proteins including ATF6, IRE1, and PERK. HCV increases TGF-ß1 and oxidative stress, which play important roles in liver fibrogenesis. HCV has been shown to induce TGF-ß1 through the generation of reactive oxygen species (ROS) and p38 MAPK, JNK, ERK1/2, and NFκB-dependent pathways. However, the relationship between HCV-induced ER stress and UPR activation with TGF-ß1 production has not been fully characterized. In this study, we found that ROS and JNK inhibitors block HCV up-regulation of ER stress and UPR activation. ROS, JNK and IRE1 inhibitors blocked HCV-activated NFκB and TGF-ß1 expression. ROS, ER stress, NFκB, and TGF-ß1 signaling were blocked by JNK specific siRNA. Knockdown IRE1 inhibited JFH1-activated NFκB and TGF-ß1 activity. Knockdown of JNK and IRE1 blunted JFH1 HCV up-regulation of NFκB and TGF-ß1 activation. We conclude that HCV activates NFκB and TGF-ß1 through ROS production and induction of JNK and the IRE1 pathway. HCV infection induces ER stress and the UPR in a JNK-dependent manner. ER stress and UPR activation partially contribute to HCV-induced NF-κB activation and enhancement of TGF-ß1.

Influence of amino acid variations in the NS3, NS4A and NS4B of HCV genotypes 1a, 1b, 3a, 3b and 6f on the response to pegylated interferon and ribavirin combination therapy.

BACKGROUND: It has been suggested that HCV proteins, core, NS3/4A, NS4B, and NS5A, contribute to the resistance of HCV to IFN and ribavirin (RBV) treatments. AIM: To assess the effects of HCV amino acid variations in NS3, NS4A and NS4B of HCV subtypes 1a, 1b, 3a, 3b and 6f on the response to pegylated interferon (Peg-IFN) and RBV therapy. METHODS: One hundred and thirty four HCV isolates of genotypes 1a, 1b, 3a, 3b and 6f obtained from HCV patients both before and at week 4 of treatments were evaluated. Amino acid sequences of NS3, NS4A and NS4B were analyzed and in compared to reference sequences of corresponding genotypes. RESULTS: The data revealed that amino acid variations within the full-length NS3, protease and helicase domains of NS3 of HCV 1a from responders were significantly higher than those from treatment failure groups as compared to reference sequences of each corresponding genotype. Similar results were observed in the full-length and helicase domain but not in the protease domain of HCV 1b. However, the number of amino acid variations in NS3 of HCV 3a, 3b and 6f as well as in NS4A and NS4B showed no difference between the viruses from responders and treatment failure group. Analysis of amino acid variations both before and at week 4 of treatment revealed that the mean number of amino acid variation in the full-length NS3 of HCV 3a and 3b from responders were also significantly higher than those from the treatment failure group. CONCLUSION: Our study suggests that the increase of amino acid variations within the NS3 protein of HCV 1a, 1b, 3a and 3b were associated with the response to Peg-IFN and RBV treatment in Thai patients.

Evolutionary consequences of G9 rotaviruses circulating in Thailand.

Infection with group A rotaviruses is the main cause of acute gastroenteritis in infants and young children worldwide. Rotavirus G9 is recognized as the fifth most predominant G genotype that spreads throughout the world. In this study, we describe the changing distribution of rotavirus G9 genotype in Chiang Mai, Thailand, from 1989 to 2005. Molecular genetic evolutionary analysis of the G9 rotavirus VP7 gene was performed. The G9 rotavirus in Thailand was first detected in Chiang Mai in 1989 with a low prevalence of 1.98%, but in 2000 and 2001 it had become the most predominant genotype, reaching prevalence of 75% and 92.2%, respectively. Then, the prevalence of G9 reached a peak of 100% in 2002 and decreased abruptly over the next 3 years, i.e. 16.7% in 2003, 32.1% in 2004, and 4.7% in 2005. Our phylogenetic analysis demonstrates that all the G9 rotaviruses circulating in Thailand belonged to lineage III, and clustered closely together based on the year of virus isolation. One amino acid change from Thr to Ile was observed in antigenic region C at position 208 between the G9 strains isolated in 1989 and the strains of 1997-2005. These findings provide the overall picture and genomic data of G9 rotaviruses circulating in Chiang Mai, Thailand.