TRIF mRNA Research Articles

Porcine circovirus type 3 capsid protein induces NF-κB activation and upregulates pro-inflammatory cytokine expression in HEK-293T cells.

Porcine circovirus type 3 (PCV3) has been widely detected throughout the world since it was first discovered on pig farms in 2015. PCV3 is closely associated with cardiac and multisystem inflammation, respiratory disease, congenital tremors, myocarditis, diarrhea, encephalitis and neurologic disease, and periarteritis. However, there have been few reports on the relationship between PCV3 and inflammatory pathways. The NF-κB signaling pathway plays an important role in the defense against viral infection. Here, we demonstrate that the capsid protein (Cap) of PCV3 plays a key role in the activation of NF-κB signaling in HEK-293T cells. Furthermore, PCV3 Cap promotes the mRNA expression of the pro-inflammatory cytokines IL6 and TNFα. In addition, PCV3 Cap promotes RIG-I and MDA5 mRNA expression in RIG-like receptor (RLR) signaling and MyD88 mRNA expression in Toll-like receptor (TLR) signaling but does not influence TRIF mRNA expression in TLR signaling. These results show that PCV3 Cap activates NF-κB signaling, possibly through the RLR and the TLR signaling pathways. This work illustrates that PCV3 Cap activates NF-κB signaling and thus may provide a basis for the pathogenesis of PCV3 and the innate immunity of the host.

Ethanol extracts from Ilex pubescens promotes cerebral ischemic tolerance via modulation of TLR4-MyD88/TRIF signaling pathway in rats

Ethnopharmacological relevancePubescent Holly Root is the dry root of Ilex pubescens Hook. et Arn. It is clinically using in the treatment for stroke and coronary artery disease. It remains unclear whether the ethanol extracts of Ilex pubescens(IPEE) treatment can promote cerebral ischemic tolerance (CIT) and exert endogenous neuroprotective effects and thus to alleviate the nerve injury caused by the subsequent persistent cerebral ischemic attacks. Aim of the studyTo investigate the effects of IPEE on CIT and its underlying molecular mechanisms. Materials and methods: Adult male Wistar rats were used in the present study. The bilateral common carotid arteries were blocked for 10 min followed a subsequent reperfusion to create the cerebral ischemic preconditioning (CIP); After 3 days post CIP, rats were subjected to middle cerebral artery occlusion/reperfusion (MCAO/R)-injury. Rats were continuously fed with IPEE for 5 days throughout the experiment period at the dose of 100 mg/kg and 200 mg/kg, respectively. Then, the brain infarct volume, histopathology, neurological deficits, and the gene/protein expression related with the TLR4-MyD88/TRIF signaling pathway were evaluated after 24 h of MCAO/R experiment. ResultsIPEE pretreatment significantly reduced the cerebral infarct volume, the neurological deficit scores, and the plasma level of neuron specific enolase (NSE) at the dose of 100 mg/kg. Meanwhile, IPEE pretreatment significantly decreased the levels of inflammatory cytokines including TNF-α, IL-6, MCP-1, MIP-1α and RANTES, while it increased the levels of anti-inflammatory cytokines, such as IL-10 and TGF-β, when compared with the group with CIP treatment alone. Moreover, the effect of IPEE treatment on CIT was in a dose-dependent manner, showing as a better effect in the group pretreated with IPEE with the dose of 100 mg/kg than that in group pretreated with IPEE with the dose of 200 mg/kg. In addition, IPEE pretreatment significantly inhibited the expressions of MyD88 mRNA and the protein expression of COX-2 and NF-κBp65, while it strengthened the expressions of TRIF mRNA and protein. The effects of IPEE pretreatment on the expression of these genes were better than that in the group treated with CIP alone. ConclusionsThe present study demonstrates that IPEE pretreatment can enhance cerebral ischemic tolerance with a underlying mechanism involved in the toll-like receptor 4 (TLR4) signaling pathway through inhibiting the production of proteins or cytokines in the downstream of MyD88 and activating TRIF dependent anti-inflammatory pathways.

Classical swine fever virus non-structural proteins modulate Toll-like receptor signaling pathways in porcine monocyte-derived macrophages

Toll-like receptors (TLRs) are crucial activators of the innate immune response that play various roles in viral infection. Studies have confirmed that classical swine fever virus (CSFV) infection has significant effects on the expression of immune effectors participating in TLR signaling pathways; however, the involvement of CSFV-encoded proteins in TLR signaling pathways remains unclear. In this study, lentiviral individually expressing CSFV non-structural proteins (NSPs) were constructed to identify the “key proteins” that affect TLR gene expression and to analyze the impacts of these proteins on factors downstream of the TLR signaling pathways. The results indicated that Npro, NS2, NS3, NS3/4A, NS4B and NS5A all failed to induce the activation of NF-κB p65. Furthermore, NS4B was found to inhibit poly (I:C) stimulation-mediated activation of the TLR3 signaling pathway in porcine monocyte-derived macrophages (pMDMs), thereby suppressing the TRIF mRNA transcription, the IRF3 protein translation and the NF-κB p65 phosphorylation, and ultimately affecting the secretion of IL-6 and IFN-β; CSFV NS5A protein could significantly increase the activation of MyD88 and IRF7 as well as the consequent synthesis of IFN-α in pMDMs. The results suggest that CSFV NSPs affect TLR-mediated innate immune responses in pMDMs.

Toll-like receptor signaling and serum levels of interferon β and lipopolysaccharide binding protein are related to abdominal obesity: a case-control study between metabolically healthy and metabolically unhealthy obese individuals

It is still unclear whether toll-like receptor (TLR) signaling and serum levels of inflammatory markers in metabolically unhealthy abdominally obese (MUAO) are due to their obesity and/or their metabolic state. We hypothesized that abdominal obesity is an important mediator of the association of metabolic state with TLR signaling and serum inflammatory markers. Therefore, in this case-control study, we compared the expression levels of TLR4 and Toll/interleukin-1 receptor domain containing adaptor protein-inducing interferon β (TRIF) and serum concentrations of interferon β and lipoprotein-binding protein (LBP) in metabolically healthy abdominally obese (MHAO) and MUAO individuals. Basal blood samples from 65 abdominally obese subjects with waist circumference (WC) of at least 95 cm were collected to determine serum metabolic parameters, IFNβ, and LBP. Those with 3 or more metabolic alterations were defined as MUAO (n = 34), and those having 2 or less were classified as MHAO (n = 31). Furthermore, messenger RNA (mRNA) was isolated from peripheral blood mononuclear cells. TLR4 and TRIF gene expression assay was performed using quantitative real-time polymerase chain reaction. There were significant differences in serum fasting blood sugar (P = .017), triglyceride (P < .001), cholesterol (P = .002), and low-density lipoprotein cholesterol (P = .034) between the MUAO and MHAO groups, whereas no significant difference was observed in the expression ratio of TLR4 and TRIF mRNA and serum levels of IFNβ and LBP. However, a significant correlation was noticed between mRNA expression levels of TLR4 and TRIF (r = 0.50, P < .001) and serum IFNβ and LBP (r = 0.70, P < .001). It is concluded that the expression levels of TLR4 and TRIF as well as serum IFNβ and LBP are more related to abdominal obesity than to metabolic health.

The optimal decoction time of Yinqiao Powder on inhibit influenza A virus FM1 in mice

Background: Yinqiao Powder (YQP) is administered in Traditional Chinese Medicine (TCM) for febrile infectious diseases and has been demonstrated to fight the prevalence of influenza. Objective: The present study aimed to identify the optimal decoction time of YQP on inhibit influenza A virus FM1 and investigate the molecular mechanisms of different decocting time YQP. Methods: The male BALB/c mice were made into pneumonia model of influenza A virus FM1. They were randomly assigned to twelve groups: blank control group, model control group, tamiflu (27.5 mg/Kg) group, 3 minutes YQP (High-dose group 30 g/Kg·d, Middle-dose group 15 g/Kg·d, and Low-dose group 7.5 g/Kg·d) groups, 6 minutes YQP (High-dose group 30 g/Kg·d, Middle-dose group 15 g/Kg·d, and Low-dose group 7.5 g/Kg·d) groups, and 12 minutes YQP (High-dose group 30 g/Kg·d, Middle-dose group 15 g/Kg·d, and Low-dose group 7.5 g/Kg·d) groups. All groups were administrated for 7 days. The mice were killed after the third and last days. Viral load of lung tissues were observed by Real-time PCR. Pulmonary index and inhibition rate were calculated by formula. Furthermore, the mice macrophage Ana-1 was infected by FM1, treated with different decocting time YQP drug-containing serum for 24 h. TLR3/4, MyD88, TRAF-6, TRAM and TRIF mRNA were detected by Real-time PCR. TLR3/4 proteins were observed by western blot. Results: All YQP intervention groups induced a reduction in the viral load and pulmonary index on the third and last days of infection, especially in 3 minutes YQP H/M/L groups and 6 minutes High-dose group. Meanwhile, YQP intervention groups led to significant decrease in TLR3/4, MyD88, TRAF-6, TRAM and TRIF mRNA levels and TLR3/4 proteins, in particular with 3 and 6 minutes YQP groups. Conclusion: YQP could protect the lung tissue and alleviate the inflammation caused by influenza A virus FM1. The optimal decoction time of YQP was 3to 6minutes on inhibit influenza A virus FM1 in mice.

Expression of Toll-Like Receptors in the Developing Brain

Toll-like receptors (TLR) are key players of the innate and adaptive immune response in vertebrates. The original protein Toll in Drosophila melanogaster regulates both host defense and morphogenesis during development. Making use of real-time PCR, in situ hybridization, and immunohistochemistry we systematically examined the expression of TLR1–9 and the intracellular adaptor molecules MyD88 and TRIF during development of the mouse brain. Expression of TLR7 and TLR9 in the brain was strongly regulated during different embryonic, postnatal, and adult stages. In contrast, expression of TLR1–6, TLR8, MyD88, and TRIF mRNA displayed no significant changes in the different phases of brain development. Neurons of various brain regions including the neocortex and the hippocampus were identified as the main cell type expressing both TLR7 and TLR9 in the developing brain. Taken together, our data reveal specific expression patterns of distinct TLRs in the developing mouse brain and lay the foundation for further investigation of the pathophysiological significance of these receptors for developmental processes in the central nervous system of vertebrates.

Growth inhibition and apoptosis of a multiple myeloma cell line induced by TLR3 pathway activation

Objective To investigate the roles of TLR3 pathway activiated by polyI:C in proliferation and apoptosis of multiple myeloma (MM) RPMI8226 cell line.Methods RPMI8226 cells were cultured in RPMI 1640 with different dose of polyl:C.Cells were collected in different time.Proliferation and apoptosis were detected by CCK-8 kit and flow cytometry,separately.Results The proliferation of RPM18226 was inhibited by polyI:C,and it was dose and time dependent,24 h:12.30％ ±2.04％,22.50％±2.20％,37.90％ ±1.30％ ; 48 h:17.80％ ±1.52％,29.60％ ±0.85％,45.80％ ±1.68％ ;72 h:25.10％±1.01％,34.60％±1.27％,60.50％±2.08％,P＜0.05.RPMI8226 cells were incubated with 50 μg/ml,100 μg/ml and 200 μg/ml polyI:C for 48 h.Apoptotic rate were 5.60％ ±1.06％,8.71％ ±1.06％ and 13.93％ ±1.17％,P＜0.05.TLR3 and TRIF mRNA expression increased obviously and dose dependent,TLR3:1.41±0.10,2.24±0.16,4.08±0.13; TRIF:1.07±0.16,1.97±0.13,3.56±0.19,P＜0.05.Conclusion The proliferation of MM cells were inhibited by TLR3 pathway obviously,and apoptosis was induced by polyI:C. Key words: Multiple myeloma; Toll like receptor 3 ; Proliferation; Apoptosis; PolyI : C

The Toll-Like receptor adaptor TRIF contributes to otitis media pathogenesis and recovery

BackgroundToll-like receptor (TLR) signalling is crucial for innate immune responses to infection. The involvement of TLRs in otitis media (OM), the most prevalent childhood disease in developed countries, has been implicated by studies in middle ear cell lines, by association studies of TLR-related gene polymorphisms, and by altered OM in mice bearing mutations in TLR genes. Activated TLRs signal via two alternative intracellular signaling molecules with differing effects; MyD88 (Myeloid differentiation primary response gene 88) inducing primarily interleukin expression and TRIF (Tir-domain-containing adaptor inducing interferon β) mediating type I interferon (IFN) expression. We tested the hypothesis that TRIF and type I IFN signaling play a role in OM, using a murine model of OM induced by non-typeable Haemophilus influenzae (NTHi). The ME inflammatory response to NTHi was examined in wild-type (WT) and TRIF-/- mice by qPCR, gene microarray, histopathology and bacterial culture.ResultsExpression of TRIF mRNA was only modesty enhanced during OM, but both type I IFN signalling genes and type I IFN-inducible genes were significantly up-regulated in WT mice. TRIF-deficient mice showed reduced but more persistent mucosal hyperplasia and less leukocyte infiltration into the ME in response to NTHi infection than did WT animals. Viable bacteria could be cultured from MEs of TRIF-/- mice for much longer in the course of disease than was the case for middle ears of WT mice.ConclusionOur results demonstrate that activation of TRIF/type I IFN responses is important in both the pathogenesis and resolution of NTHi-induced OM.

MyD88 but not TRIF is essential for osteoclastogenesis induced by lipopolysaccharide, diacyl lipopeptide, and IL-1alpha.

Myeloid differentiation factor 88 (MyD88) plays essential roles in the signaling of the Toll/interleukin (IL)-1 receptor family. Toll–IL-1 receptor domain-containing adaptor inducing interferon-β (TRIF)-mediated signals are involved in lipopolysaccharide (LPS)-induced MyD88-independent pathways. Using MyD88-deficient (MyD88−/−) mice and TRIF-deficient (TRIF−/−) mice, we examined roles of MyD88 and TRIF in osteoclast differentiation and function. LPS, diacyl lipopeptide, and IL-1α stimulated osteoclastogenesis in cocultures of osteoblasts and hemopoietic cells obtained from TRIF−/− mice, but not MyD88−/− mice. These factors stimulated receptor activator of nuclear factor-κB ligand mRNA expression in TRIF−/− osteoblasts, but not MyD88−/− osteoblasts. LPS stimulated IL-6 production in TRIF−/− osteoblasts, but not TRIF−/− macrophages. LPS and IL-1α enhanced the survival of TRIF−/− osteoclasts, but not MyD88−/− osteoclasts. Diacyl lipopeptide did not support the survival of osteoclasts because of the lack of Toll-like receptor (TLR)6 in osteoclasts. Macrophages expressed both TRIF and TRIF-related adaptor molecule (TRAM) mRNA, whereas osteoblasts and osteoclasts expressed only TRIF mRNA. Bone histomorphometry showed that MyD88−/− mice exhibited osteopenia with reduced bone resorption and formation. These results suggest that the MyD88-mediated signal is essential for the osteoclastogenesis and function induced by IL-1 and TLR ligands, and that MyD88 is physiologically involved in bone turnover.