Calcium and its major downstream effector, calcium/calmodulin-dependent protein kinase II (CaMKII), are found to be important for the functions of immune cells. Lipopolysaccharide (LPS) has been shown to induce intracellular calcium release in macrophages; however, whether and how CaMKII is required for Toll-like receptor (TLR) signaling remain unknown. Here we demonstrate that TLR 4, 9, and 3 ligands markedly induce intracellular calcium fluxes and activate CaMKII-␣ in macrophages. Selective inhibition or RNA interference of CaMKII significantly suppresses TLR4, 9, 3-triggered production of interleukin-6 (IL-6), tumor necrosis factor-␣, and interferon-␣/ (IFN-␣/) in macrophages. Coincidently, overexpression of constitutively active CaMKII-␣ significantly enhances production of the above cytokines. In addition to the activation of mitogen-activated protein kinase and nuclear factor B pathways, CaMKII-␣ can directly bind and phosphorylate transforming growth factor -activated kinase 1 (TAK1) and IFN regulatory factor 3 (IRF3; serine IntroductionOn recognition of pathogenic components, Toll-like receptors (TLRs) are activated, leading to a variety of signaling events that initiate innate immunity and activate immune cells to produce proinflammatory cytokines and type I interferon (IFN). 1,2 Most of the members of the TLR family, with the exception of TLR3, trigger immune response via the conserved myeloid differentiation factor 88 (MyD88)-dependent pathway, which involves MyD88, interleukin-1 (IL-1) receptor-associated kinase 1 (IRAK1), tumor necrosis factor (TNF) receptor-associated factor 6 (TRAF6), transforming growth factor- (TGF-)-activated kinase 1 (TAK1), downstream mitogen-activated protein kinases (MAPKs), and nuclear factor B (NF-B). 2,3 Toll/IL-1 receptor-domain-containing adaptor protein inducing IFN- (TRIF) has been found to induce the expression of type I IFN in response to TLR4 and TLR3 ligands, which associates with TANK-binding kinase 1 (TBK1) and activates downstream IFN regulatory factor 3 (IRF3). In addition, the TRIF pathway also contributes to TLR3-and TLR4-activated proinflammatory cytokine production. 3,4 TLR activation is essential for provoking the innate immune response and enhancing adaptive immunity against invading pathogens. Less efficient activation of the TLR response may not evoke potent anti-infection or antitumor immunity; however, excessive activation of TLR may also induce immunopathologic processes, such as endotoxin shock and autoimmune diseases. How to manipulate or control the TLR response for prevention and treatment of inflammatory and immunologic diseases largely depends on the understanding of the molecular basis for TLR responses. Up to now, molecular mechanisms for the initiation and regulation of TLR responses remain to be fully understood. In addition to the MyD88-or TRIF-dependent pathway, ligation of TLRs has been found to activate various other intracellular signaling molecules, such as phosphatidylinositol 3-kinase (PI3K)/ AKT 5 and MAPK kinase kinase (ME...
BackgroundIt has been previously reported that IL-22, one of the cytokines secreted by Th17 cells, demonstrates both a protective and inflammatory promotion effect in inflammatory bowel disease (IBD) through STAT3 signaling activation. We sought to investigate the role of IL-22 expression in colon cancer (CC).MethodsThe expression of IL-22 and related molecules were detected in human CC, the detail function and mechanism of IL-22 were investigated by in vivo and in vitro model.ResultsOur results demonstrated significant upregulation of IL-22 in human CC tumor infiltrated leukocytes (TILs) compared to peripheral lymphocytes. Moreover, our findings demonstrated that IL-22 expression was significantly higher in ulcerative colitis (UC) tissues versus normal colon tissues. Both IL-22 receptor α1 (IL-22RA1) and IL-23 were highly expressed in CC and UC tissues compared to normal controls. TILs exhibiting various IL-22 expression levels isolated from CC patients were demonstrated to enhance tumor growth and metastasis co-transplanted with Hct-116 cells underwent subcutaneous transplantation in mice model. Tumor growth and metastasis was promoted by STAT3 phosphorylation and upregulation of its downstream genes such as Bcl-xl, CyclinD1, and VEGF. In vitro studies confirmed the anti-apoptotic and pro-proliferation effect of IL-22 according to the BrdU cooperation assay and peroxide induced apoptosis analysis with or without the presence of IL-22.ConclusionIn this study we demonstrated that excessive IL-22 in the CC and UC microenvironment leads to tumor growth, inhibition of apoptosis, and promotion of metastasis depend on STAT3 activation.
The median (interquartile range) age of the patients was 35 (24-50) years. A total of 8 patients (89%) reported fever (mean [SD] duration, 5.78 [2.99] days), and 7 patients (78%) reported a cough. Few patients (3 [33%]) showed debilitation, chest distress (2 [22%]), or anorexia (1 [11%]). Diarrhea, myalgia, rhinorrhea, and headache were not reported. C-reactive protein levels were elevated in 9 patients (100%; mean [SD], 3.34 [3.18] mg/dL; to convert to milligrams per liter, multiply by 10).Lymphopenia occurred in 3 patients (33%), lactate dehydrogenase was increased in 3 patients (33%;Author affiliations and article information are listed at the end of this article.
Inappropriate activation of TLR9 has been found to be involved in the pathogenesis of autoimmune diseases such as systemic lupus erythematosus. TLR9 antagonists have been proposed to be therapeutic for some kinds of autoimmune diseases. In contrast, new negative regulators of TLR9 signal pathway need to be identified, and the mechanisms for the control of TLR9 response need to be fully investigated. It is well known that TLR9 will be finally transported to late endosome/lysosome once activated; however, the exact mechanism and the biological significance of the redistribution have not been fully elucidated. Ras related in brain (Rab)7b is a small guanosine triphosphatase, identified by us before, which is mainly localized in late endosome/lysosome. Our previous study shows that Rab7b can negatively regulate TLR4 signaling by promoting lysosomal degradation of TLR4. In this study, we show that TLR9 ligation can inhibit Rab7b expression in macrophages via ERK and p38 activation. In turn, the late endosome/lysosome-localized Rab7b can colocalize with TLR9 in lysosomal-associated membrane protein 1-positive compartment and down-regulate the expression of the TLR9 in macrophages by promoting TLR9 degradation once TLR9 is activated. Accordingly, Rab7b can negatively regulate TLR9-triggered production of TNF-α, IL-6, and IFN-β in macrophages by impairing activation of MAPKs and NF-κB pathways. Our results suggest that the late endosome/lysosome-localized Rab7b can down-regulate TLR9-triggered proinflammatory cytokine and type I IFN production by impairing TLR9 signaling via promotion of TLR9 degradation.
RIG-I–like helicases and TLRs are critical sensors in the induction of type I IFN and proinflammatory cytokines to initiate innate immunity against invading pathogens. However, the mechanisms for the full activation of TLR and RIG-I–triggered innate response remain to be fully investigated. Grb2-associated binder 1 (Gab1), a member of scaffolding/adaptor proteins, can mediate signal transduction from many receptors, however, whether and how Gab1 is required for TLR and RIG-I–triggered innate responses remain unknown. In this study, we demonstrated that Gab1 significantly enhances TLR4-, TLR3-, and RIG-I–triggered IL-6, IL-1β, and IFN-α/β production in macrophages. Gab1 knockdown in primary macrophages or Gab1 deficiency in mouse embryonic fibroblasts significantly suppresses TLR3/4- and RIG-I–triggered production of IL-6, IL-1β, and IFN-α/β. Consistently, Gab1 deficiency impairs vesicular stomatitis virus (VSV) infection-induced IFN-α/β production. In addition to promoting both MyD88- and TLR/IL-1 receptor domain-containing adaptor protein inducing IFN-β–dependent MAPKs and NF-κB activation, Gab1 enhances PI3K/Akt activation by directly binding p85 in TLR signaling and VSV infection. Accordingly, Gab1 inhibits VSV replication and VSV infection-induced cell damage by inducing type I IFNs and IFN-inducible gene expression via PI3K/Akt pathway. Therefore, Gab1 is needed for full activation of TLR3/4- and RIG-I–triggered innate responses by promoting activation of PI3K/Akt, MAPKs, and NF-κB pathways.
The introduction of induction chemotherapy provides an expectation of laryngeal function preservation without reduction in survival for patients with advanced laryngeal squamous cell carcinoma. The antitumor activity of conventional intravenous chemotherapy, however, is limited by systemic toxicity. The polymeric drug system delivered locally provides a novel modality of increasing therapeutic concentrations of drug for a prolonged period while decreasing systemic levels. In the current study, paclitaxel-loaded sustained-release microspheres were developed using poly(lactic-co-glycolic acid) as a drug carrier. Intratumoral administration of paclitaxel in the formulation of polymer showed enhanced efficacy against laryngeal squamous cell carcinoma in nude mice compared with conventional paclitaxel injection via the intratumoral or intraperitoneal route. No significant toxic reactions were observed in the experiment. Immunohistochemical findings indicated that paclitaxel exhibited antiangiogenic activity by inhibiting the expression of basic fibroblast growth factor and vascular endothelial growth factor within the tumor. Moreover, this effect could be better exploited via localized delivery of polymeric paclitaxel. In conclusion, direct administration of polymeric drug system at the tumor sites proved to be promising for the treatment of laryngeal carcinoma.
Background Donor variational arteries often require complex reconstruction. Methods We analysed the incidence of different variations, types of arterial reconstructions and their impact on postoperative results from 409 patients undergoing liver transplantation at Karolinska Institute between 2007 and 2015. Results A total of 292 (71.4%) liver grafts had a standard hepatic artery (SHA), and 117 (28.6%) showed hepatic artery variants (HAV). 58% of HAV needed reconstruction. The main variations were variant left hepatic artery (45.3%) from the gastric artery; variant right hepatic artery (38.5%); and a triple combination of variant right and left hepatic artery and the proper hepatic artery from the common hepatic artery (12.8%); other 3.4%. Patients/graft survival and arterial complications were not different between SHA and HAV. Incidence of biliary stricture was numerically higher in left hepatic artery variants (p = 0.058) and in variants where no arterial reconstruction was performed (p = 0.001). Operation and arterial warm ischaemia time were longer in the HAV group. The need for intraoperative re-reconstruction was higher in the HAV group (p = 0.04). Intraoperative bleeding was larger after back-table reconstruction than with intraoperative reconstruction (p = 0.04). Conclusion No overall differences were found between the HAV and the SHA groups. Occurrence of a variant left hepatic artery and HAV with no reconstruction seems to increase the risk of biliary strictures.
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