The signaling pathway of NADPH oxidase and its role in glomerular diseases

Abstract

Nicotinamide adenine dinucleotide phosphate (NADPH) oxidase (Nox), a major source of reactive oxygen species, is a critical mediator of redox signaling. It is well-documented that oxidative stress is associated with the development of glomerular diseases (GN). Hence, the Nox was also thought to be involved in the pathogenesis of GN. However, the expression of Nox in various GN was not consistent, the mechanisms by which the activity of the Nox enzymes in regulating renal cells remains unclear. Signaling pathways might be very important in the pathogenesis of GN. We performed this review to provide a relatively complete signaling pathways flowchart for Nox to the investigators who were interested in the role of Nox in the pathogenesis of GN. Here, we reviewed the signal transduction pathway of Nox and its role in the pathogenesis of GN.     

Toll-like receptors are key participants in innate immune responses

During an infection, one of the principal challenges for the host is to detect the pathogen and activate a rapid defensive response. The Toll-like family of receptors (TLRs), among other pattern recognition receptors (PRR), performs this detection process in vertebrate and invertebrate organisms. These type I transmembrane receptors identify microbial conserved structures or pathogen-associated molecular patterns (PAMPs). Recognition of microbial components by TLRs initiates signaling transduction pathways that induce gene expression. These gene products regulate innate immune responses and further develop an antigen-specific acquired immunity. TLR signaling pathways are regulated by intracellular adaptor molecules, such as MyD88, TIRAP/Mal, between others that provide specificity of individual TLR- mediated signaling pathways. TLR-mediated activation of innate immunity is involved not only in host defense against pathogens but also in immune disorders. The involvement of TLR-mediated pathways in auto-immune and inflammatory diseases is described in this review article.     

Role of toll-like receptors gene polymorphism in hepatocellular carcinoma

Abstract

Toll-like receptors (TLRs), evolutionarily conserved innate, play important roles in the development of autoimmunity. TLRs proteins are localized on the cell surface or in endosomes and play critical roles in innate immune responses against different pathogens. Aberrant stimulation of the innate immune system through intracellular TLRs may lead to hyperactive immune responses and contribute to the pathogenesis of hepatocellular carcinoma (HCC). HCC is the seventh most common cancer and the third leading cause of cancer deaths worldwide, and innate immune takes a most important role in HCC. There was no review to sum up the role of TLRs gene polymorphism in HCC. This review was performed to sum up the role of TLRs gene polymorphism in HCC.     

Role of toll-like receptors gene polymorphism in renal transplantation

Abstract

Toll-like receptors (TLRs), evolutionarily conserved innate, are expressed in a wide variety of tissues and cell types, and they play key role in the innate immune system. Gene mutation is an important factor associated with some diseases risk and gene polymorphism of TLRs can influence their function to take part in the physiological process in the body. Chronic kidney disease causes high morbidity and mortality, and renal transplantation provides the optimal treatment for people with end-stage renal disease. Innate immune takes a most important role in renal transplantation. There are some studies reporting that TLRs gene polymorphism takes an important role in the renal transplantation. However, no review summed up the role of TLRs gene polymorphism in renal transplantation. The literatures were searched extensively and this review was performed to review the role of TLRs gene polymorphism in renal transplantation.     

Expression of toll-like receptor 4 is down-regulated during progression of cervical neoplasia

Chronic infection and inflammation are among the most important factors contributing to cancer development and growth. Toll-like receptors (TLRs) are important families of pattern recognition receptors, which recognize conserved components of microbes and trigger the immune response against invading microorganisms. TLR4 is the signaling receptor for lipopolysaccharide (LPS), the endotoxic component of Gram-negative bacteria. Recent studies demonstrate that TLRs are expressed in some tumor cells, and that the expression of TLRs in these cells is associated with tumorigenesis. Cervical intraepithelial neoplasia (CIN) is a key stage in the development of cervical cancer and human papillomavirus (HPV) infection is an essential factor in cervical carcinogenesis. As the cervix is in constant contact with bacteria, especially Gram-negative bacteria, we hypothesize that TLR4-mediated bacterial stimulation may be involved in the tumorigenesis of cervical cancer. In the present study, the expression and distribution of TLR4 in CIN and cervical squamous carcinoma were investigated by immunohistochemistry. To our surprise, we observed a decrease in the expression of TLR4 during the progression of cervical neoplasia and this down-regulation of TLR4 appeared to be associated with the expression of \textP ^{1 6\textINK4A} , {\text{P}}^{{ 1 6^{\text{INK4A}} }} , which is a crucial marker of HPV integration into host cells. These data offer further insight regarding the association of HPV infection and TLR signaling during the carcinogenesis of cervical cancer.     

The role of innate immune receptors in the control of Brucella abortus infection: toll-like receptors and beyond

Research into intracellular sensing of microbial products is an up and coming field in innate immunity. Toll-like receptors (TLRs) recognize Brucella spp. and bacterial components and initiate mononuclear phagocyte responses that influence both innate and adaptive immunity. Recent studies have revealed the intracellular signaling cascades involved in the TLR-initiated immune response to Brucella infection. TLR2, TLR4 and TLR9 have been implicated in host interactions with Brucella; however, TLR9 has the most prominent role. Further, the relationship between specific Brucella molecules and various signal transduction pathways needs to be better understood. MyD88-dependent and TRIF-independent signaling pathways are involved in Brucella activation of innate immune cells through TLRs. We have recently reported the critical role of MyD88 molecule in dendritic cell maturation and interleukin-12 production during B. abortus infection. This article discusses recent studies on TLR signaling and also highlights the contribution of NOD and type I IFN receptors during Brucella infection. The better understanding of the role by such innate immune receptors in bacterial infection is critical in host-pathogen interactions.     

Comparative RNA-Seq analysis reveals insights in Salmonella disease resistance of chicken; and database development as resource for gene expression in poultry

Salmonella, one of the major infectious diseases in poultry, causes considerable economic losses in terms of mortality and morbidity, especially in countries that lack effective vaccination programs. Besides being resistant to diseases, indigenous chicken breeds are also a potential source of animal protein in developing countries. For understanding the disease resistance, an indigenous chicken line Kashmir faverolla, and commercial broiler were selected. RNA-seq was performed after challenging the chicken with Salmonella Typhimurium. Comparative differential expression results showed that following infection, a total of 3153 genes and 1787 genes were differentially expressed in the liver and spleen, respectively. The genes that were differentially expressed included interleukins, cytokines, NOS2, Avβ-defensins, toll-like receptors, and other immune-related gene families. Most of the genes and signaling pathways involved in the innate and adaptive immune responses against bacterial infection were significantly enriched in the Kashmir faverolla. Pathway analysis revealed that most of the enriched pathways were MAPK signaling pathway, NOD-like receptor signaling pathway, TLR signaling pathway, PPAR signaling pathway, endocytosis, etc. Surprisingly some immune-related genes like TLRs were upregulated in the susceptible chicken breed. On postmortem examination, the resistant birds showed small lesions in the liver compared to large necrotic lesions in susceptible birds. The pathological manifestations and RNA sequencing results suggest a balancing link between resistance and infection tolerance in Kashmir faverolla. Here we also developed an online Poultry Infection Database (https://skuastk.org/pif/index.html), the first publicly available gene expression resource for disease resistance in chickens. The available database not only shows the data for gene expression in chicken tissues but also provides quick search, visualization and download capacity.     

The Importance of Toll‐like Receptors in NF‐κB Signaling Pathway Activation by Helicobacter pylori Infection and the Regulators of this Response

Helicobacter pylori (H. pylori) is a common pathogenic bacterium in the stomach that infects almost half of the population worldwide and is closely related to gastric diseases and some extragastric diseases, including iron‐deficiency anemia and idiopathic thrombocytopenic purpura. Both the Maastricht IV/Florence consensus report and the Kyoto global consensus report have proposed the eradication of H. pylori to prevent gastric cancer as H.pylori has been shown to be a major cause of gastric carcinogenesis. The interactions between H. pylori and host receptors induce the release of the proinflammatory cytokines by activating proinflammatory signaling pathways such as nuclear factor kappa B (NF‐κB), which plays a central role in inflammation, immune response, and carcinogenesis. Among these receptors, Toll‐like receptors (TLRs) are classical pattern recognition receptors in the recognition of H. pylori and the mediation of the host inflammatory and immune responses to H. pylori. TLR polymorphisms also contribute to the clinical consequences of H. pylori infection. In this review, we focus on the functions of TLRs in the NF‐κB signaling pathway activated by H. pylori, the regulators modulating this response, and the functions of TLR polymorphisms in H.pylori‐related diseases.     

The Expression of Dectin-1, Irak1 and Rip2 During the Host Response to <Emphasis Type="Italic">Aspergillus fumigatus</Emphasis>

Background

C-type lectin receptors (CLRs), Toll-like receptors (TLRs), and Nod-like receptors (NLRs) have the ability to recognize Aspergillus fumigatus (A. fumigates) and induce innate immune response. Dectin-1 is a well-described CLR, while interleukin-1 receptor-associated kinase 1 (Irak1) and receptor-interacting protein 2 (Rip2) are pivotal adaptor proteins of TLRs and NLRs signaling pathways, respectively.

Objectives

Our primary aim is to elucidate whether Dectin-1 regulates the expression of Irak1 and Rip2, and confirm that CLRs, TLRs, and NLRs pathways act synergistically in response to A. fumigatus infection.

Methods

Pulmonary infection mouse models were established. Myeloid cells were differentiated in cell culture and examined by inverted microscopy, flow cytometry, and scanning electron microscopy. The relative mRNA levels were determined by qRT-PCR. The protein expression levels were determined by immunohistochemistry and Western blot.

Results

The expression of Dectin-1, Irak1, Rip2, and phosphorylation level of nuclear factor (NF)-κB p65 were induced by conidia in immunocompetent mice, while their expression and phosphorylation level were inhibited in immunocompromised mice after the administration of conidia. Conidia increased the expression of Dectin-1, Irak1, and Rip2 in myeloid cells, while Dectin-1 silencing significantly reduced their expression.

Conclusion

Our findings demonstrate that Dectin-1, Irak1, and Rip2 are involved in response to A. fumigatus infection. Dectin-1 modulates the expression of Irak1 and Rip2. Additionally, these three signaling pathways are interconnected, and CLRs pathway plays a dominant role against A. fumigatus invasion.

     

Signaling pathways of prohibitin and its role in diseases

Abstract

Prohibitin (PHB), appearing to be a negative regulator of cell proliferation and to be a tumor suppressor, has been connected to diverse cellular functions including cell cycle control, senescence, apoptosis and the regulation of mitochondrial activities. It is a growth regulatory gene that has pleiotropic functions in the nucleus, mitochondria and cytoplasmic compartments. However, in different tissues/cells, the expression of PHB was different, such as that it was increased in most of the cancers, but its expression was reduced in kidney diseases. Signaling pathways might be very important in the pathogenesis of diseases. This review was performed to provide a relatively complete signaling pathways flowchart for PHB to the investigators who were interested in the roles of PHB in the pathogenesis of diseases. Here, we review the signal transduction pathways of PHB and its role in the pathogenesis of diseases.     

Role of miR-107 and its signaling pathways in diseases

Abstract

MicroRNAs exert their biologic effects by targeting specific mRNAs for degradation or translational inhibition. MicroRNA-mediated regulation is complex, potentially affecting expression of the host gene, related enzymes within the same pathway or apparently distinct targets. miR-107 is found to be implicated in the pathogenesis of some diseases. This review was performed to sum up the role of miR-107 and its signaling pathways in renal diseases.     

Molecular dissection of plasmacytoid dendritic cell activation in vivo during a viral infection

Plasmacytoid dendritic cells (pDC) are the major source of type I interferons (IFN‐I) during viral infections, in response to triggering of endosomal Toll‐like receptors (TLRs) 7 or 9 by viral single‐stranded RNA or unmethylated CpG DNA, respectively. Synthetic ligands have been used to disentangle the underlying signaling pathways. The adaptor protein AP3 is necessary to transport molecular complexes of TLRs, synthetic CpG DNA, and MyD88 into endosomal compartments allowing interferon regulatory factor 7 (IRF7) recruitment whose phosphorylation then initiates IFN‐I production. High basal expression of IRF7 by pDC and its further enhancement by positive IFN‐I feedback signaling appear to be necessary for robust cytokine production. In contrast, we show here that in vivo during mouse cytomegalovirus (MCMV) infection pDC produce high amounts of IFN‐I downstream of the TLR9‐to‐MyD88‐to‐IRF7 signaling pathway without requiring IFN‐I positive feedback, high IRF7 expression, or AP3‐driven endosomal routing of TLRs. Hence, the current model of the molecular requirements for professional IFN‐I production by pDC, established by using synthetic TLR ligands, does not strictly apply to a physiological viral infection.     

Toll-like receptor 3 and TICAM genes in catfish: species-specific expression profiles following infection with Edwardsiella ictaluri

Toll-like receptors (TLRs) are a family of transmembrane proteins that recognize specific pathogen-associated molecular patterns and use conserved signaling pathways to activate proinflammatory cytokines and type-1 interferons to fight infection. TLR3 in mammals is best known for its recognition of dsRNA as ligand and its MyD88-independent signaling. TLR3, upon recognition of dsRNA, recruits and binds its adaptor protein TIR domain-containing adapter molecule (TICAM) 1. Here we report the genomic sequences and structures of TLR3 and a TICAM adaptor from channel catfish (Ictalurus punctatus). Whereas a partial TLR3 cDNA sequence has been reported from channel catfish, and complete TLR3 genes are known from other teleost fish species, a complete TICAM sequence has not been previously reported from a nonmammalian species. Analysis of catfish TLR3 and TICAM expression after infection with Edwardsiella ictaluri, the causative agent of enteric septicemia of catfish (ESC), suggested a conserved TLR3-TICAM receptor–adaptor relation in catfish. Comparison of TLR3 and TICAM expression profiles in channel catfish with those from the closely related blue catfish species (Ictalurus furcatus), which exhibits strong resistance to ESC, revealed a striking pattern of species-specific expression. A dramatic downregulation of TLR3 and TICAM gene expression was observed in blue catfish head kidney and spleen, which we speculate may be the result of maturation and migration of different cell types to and from the lymphoid tissues following infection.Electronic supplementary material Supplementary material is available in the online version of this article at and is accessible for authorized users.Puttharat Baoprasertkul and Eric Peatman contributed equally to this work.     

小麦叶锈菌休眠与萌发夏孢子的差异表达

【目的】小麦叶锈菌引起的小麦叶锈病是小麦的重要病害之一,孢子萌发和侵入气孔是保证叶锈菌正常侵染寄主的重要前提。本研究旨在研究小麦叶锈菌夏孢子萌发的差异表达特性,为揭示萌发的机制及其与致病的关系提供依据。【方法】利用小麦叶锈菌致病类型THTT的休眠夏孢子和萌发夏孢子进行RNA-seq分析。【结果】在萌发夏孢子中筛选出相比休眠夏孢子上调表达的基因为4400个,下调基因5325个。GO富集分析发现,上调差异基因主要涉及细胞进程、有机物代谢、信号传导、单个有机体过程、催化酶活性等;下调基因主要涉及单组织过程、单个有机体细胞过程、有机物代谢过程、催化活性调节等过程。利用KEGG分析发现,差异基因共参与109条通路,从中筛选出两条与孢子萌发相关的通路——丝裂原活化蛋白激酶(MAPK)信号通路和囊泡运输中的SNARE蛋白交流。10个基因的定量分析结果与基因数字表达谱分析结果一致。【结论】研究获得了叶锈菌孢子萌发及侵入气孔过程中的重要差异基因,研究结果为研究叶锈菌致病机制奠定基础。     

Uracil-induced signaling pathways for DUOX-dependent gut immunity

ABSTRACT

Intestinal dual oxidase (DUOX) activation is the first line of host defense against enteric infection in Drosophila. DUOX enzymatic activity is mainly controlled by phospholipase C-β (PLCβ)-dependent calcium mobilization, whereas DUOX gene expression is mainly controlled by the MEKK1-p38 mitogen-activated protein kinase pathway. Furthermore, bacterial-derived uracil molecules act as ligands for DUOX activation. However, our current understanding of uracil-induced signal transduction pathways remain incomplete. We have recently found that uracil stimulates Hedgehog signaling, which in turn upregulates cadherin99C (Cad99C) expression in enterocytes. Cad99C molecules, along with PLCβ and protein kinase C, induce the formation of signaling endosomes that facilitate intracellular calcium mobilization for DUOX activity. These observations illustrate the complexity of signaling cascades in uracil-induced signaling pathways. Here, we further demonstrated the role of lipid raft formation and calmodulin-dependent protein kinase-II on endosome formation and calcium mobilization, respectively. Moreover, we will provide a brief discussion on two different models for uracil recognition and uracil-induced DUOX activation in Drosophila enterocytes.     

三棱内酯B调控人冠状动脉内皮细胞基因表达谱的生物信息学分析

目的:分析三棱内酯B在人冠状动脉内皮细胞中的表达谱数据集,寻找三棱内酯B调控血管内皮功能的关键作用靶点。方法:基于GEO公共数据库,下载原始表达谱数据集(GSE44598),经过差异基因筛选,功能注释,通路富集,信号通路网络以及基因互作网络分析,找出三棱内酯B对人冠状动脉内皮细胞基因表达谱产生影响的关键基因和信号通路。结果:同对照组相比,三棱内酯B给药组共有5224个基因有显著性差异,包括2628个上调基因和2596个下调基因。基因功能注释和信号通路富集分析表明,差异基因主要参与了细胞周期过程。网络分析显示,MAPK信号通路、细胞周期通路以及PLCG2,PRKACA和ADCY4等为关键信号通路和基因。结论:三棱内酯B通过影响PLCG2,PRKACA,ADCY4等基因的表达,参与MAPK和细胞周期等信号通路,从而调节人冠状内皮细胞的功能。这些关键基因和信号通路是三棱内酯B在心血管疾病治疗应用中潜在的作用靶点。