scholarly journals Toll-Like Receptor Signaling Pathways: Novel Therapeutic Targets for Cerebrovascular Disorders

2021 ◽  
Vol 22 (11) ◽  
pp. 6153
Author(s):  
Rezan Ashayeri Ahmadabad ◽  
Zahra Mirzaasgari ◽  
Ali Gorji ◽  
Maryam Khaleghi Ghadiri
Keyword(s):  
Signaling Pathway ◽  
Inflammatory Responses ◽  
Critical Role ◽  
Cerebrovascular Disorders ◽  
Cerebrovascular Diseases ◽  
Tlr Signaling ◽  
Integral Role ◽  
Potential Benefits ◽  
Tlr Signaling Pathway

Toll-like receptors (TLRs), a class of pattern recognition proteins, play an integral role in the modulation of systemic inflammatory responses. Cerebrovascular diseases (CVDs) are a group of pathological conditions that temporarily or permanently affect the brain tissue mostly via the decrease of oxygen and glucose supply. TLRs have a critical role in the activation of inflammatory cascades following hypoxic-ischemic events and subsequently contribute to neuroprotective or detrimental effects of CVD-induced neuroinflammation. The TLR signaling pathway and downstream cascades trigger immune responses via the production and release of various inflammatory mediators. The present review describes the modulatory role of the TLR signaling pathway in the inflammatory responses developed following various CVDs and discusses the potential benefits of the modulation of different TLRs in the improvement of functional outcomes after brain ischemia.

scholarly journals Luteolin Targets the Toll-Like Receptor Signaling Pathway in Prevention of Hepatic and Adipocyte Fibrosis and Insulin Resistance in Diet-Induced Obese Mice

Nutrients ◽  
2018 ◽  
Vol 10 (10) ◽  
pp. 1415 ◽  
Author(s):  
Eun-Young Kwon ◽  
Myung-Sook Choi
Keyword(s):  
Insulin Resistance ◽  
Signaling Pathway ◽  
Low Grade ◽  
Toll Like Receptor ◽  
High Fat ◽  
Gene Expressions ◽  
Tlr Signaling ◽  
Low Grade Inflammation ◽  
Tlr Signaling Pathway

This study was to investigate the protective role of luteolin on inflammation-mediated metabolic diseases, focusing on the role of luteolin in the modulation of the Toll-like receptor (TLR) signaling pathway. C57BL/6J mice were fed a normal, high-fat, or high-fat + 0.005% (w/w) luteolin diet for 16 weeks. Luteolin improved chronic low-grade inflammation by modulating the TLR signaling pathway, resulting in reduced pro-inflammatory cytokines and macrophage accumulation. A positive relationship was detected between gene expressions of Tlr5, Map2k7, Mapk12, Mapk13, and Mapk9 and lipogenesis in epididymal white adipose tissue (eWAT) of luteolin-treated mice, which was linked to attenuation of hepatic lipotoxicity by increasing free fatty acid (FFA) flux to the WAT. Luteolin prevented fibrosis by decreasing extracellular matrix accumulation and cathepsin gene expressions, while enhancing the hepatic antioxidant system. Emr1 and Ccl7, important markers inducing low-grade inflammation, were affected by advanced age and greater body weight, which were normalized by luteolin treatment. Luteolin improved insulin resistance by normalizing pancreatic islet dysfunction and differentially modulating the plasma glucagon-like peptide-1 and gastric inhibitory polypeptide levels. Our results suggest that luteolin ameliorates diet-induced obesity and its comorbidities. Overall, this study provides novel insights into the effect of luteolin on the links among adiposopathy, insulin resistance, hepatic steatosis, and fibrosis.

scholarly journals Effect of a Mushroom (Coriolus versicolor) Based Probiotic on the Expression of Toll-like Receptors and Signal Transduction in Goat Neutrophils

2016 ◽  
Vol 6 (1) ◽  
pp. 71 ◽  
Author(s):  
Kingsley Ekwemalor ◽  
Emmanuel Asiamah ◽  
Mulumebet Worku
Keyword(s):  
Innate Immunity ◽  
Signaling Pathway ◽  
Cold Treatment ◽  
Free Water ◽  
Control Group ◽  
Tlr Signaling ◽  
Blood Neutrophils ◽  
Definition Of ◽  
Tlr Signaling Pathway

<p class="1Body">Neutrophils recognize and destroy pathogens through activation of the Toll like receptor (TLR) system as part of the inflammatory response of innate immunity. The expression and modulation of genes in the TLR signaling pathway in caprine blood neutrophils was investigated. Following initial screening for infection, goats (N=15) were assigned to three groups of five (n=5) individuals. Goats were drenched daily with 10 mL of powdered CorPet (Mycology labs Inc) soaked in hot (treatment I) or cold (treatment II) sterile filtered endotoxin free water, for a 4-week period. A control group of five age-matched goats received sterile water (treatment III). Blood was collected weekly and analyzed for packed cell volume and white blood cell differential counts. At weeks 1 and 4 neutrophils were isolated, using differential centrifugation and hypotonic lysis of red blood cells. The concentration and purity of total RNA isolated using Trizol was determined on a Nanodrop spectrophotometer. The RETROscript kit was used to synthesize cDNA. The expression of 84 genes in the human TLR signaling pathway RT<sup>2</sup> PCR Array was evaluated using real time PCR and the Livak method. The house keeping gene GAPDH was used to normalize the data. At week 1 untreated goats expressed 48 genes in the pathway. Goat neutrophils expressed 10 TLRs. Mushroom extracts modulated expression of and signaling by TLR. These results will help in the definition of the role of TLR expression in neutrophils and its contribution to goat innate immunity. Further this may aid in the design of therapeutics for goat health.</p>

scholarly journals The Inflammatory Role of Pro-Resolving Mediators in Endometriosis: An Integrative Review

2021 ◽  
Vol 22 (9) ◽  
pp. 4370
Author(s):  
Cássia de Fáveri ◽  
Paula M. Poeta Fermino ◽  
Anna P. Piovezan ◽  
Lia K. Volpato
Keyword(s):  
Intracellular Signaling ◽  
Inflammatory Responses ◽  
Therapeutic Potential ◽  
Critical Role ◽  
Integrative Review ◽  
Inflammatory Factors ◽  
Resolvin D1 ◽  
Endogenous Factors

The pathogenesis of endometriosis is still controversial, although it is known that the inflammatory immune response plays a critical role in this process. The resolution of inflammation is an active process where the activation of endogenous factors allows the host tissue to maintain homeostasis. The mechanisms by which pro-resolving mediators (PRM) act in endometriosis are still little explored. Thus, this integrative review aims to synthesize the available content regarding the role of PRM in endometriosis. Experimental and in vitro studies with Lipoxin A4 demonstrate a potential inhibitory effect on endometrial lesions’ progression, attenuating pro-inflammatory and angiogenic signals, inhibiting proliferative and invasive action suppressing intracellular signaling induced by cytokines and estradiol, mainly through the FPR2/ALX. Investigations with Resolvin D1 demonstrated the inhibition of endometrial lesions and decreased pro-inflammatory factors. Annexin A1 is expressed in the endometrium and is specifically present in women with endometriosis, although the available studies are still inconsistent. Thus, we believe there is a gap in knowledge regarding the PRM pathways in patients with endometriosis. It is important to note that these substances’ therapeutic potential is evident since the immune and abnormal inflammatory responses play an essential role in endometriosis development and progression.

scholarly journals Critical Role of Zinc as Either an Antioxidant or a Prooxidant in Cellular Systems

2018 ◽  
Vol 2018 ◽  
pp. 1-11 ◽  
Author(s):  
Sung Ryul Lee
Keyword(s):  
Oxidative Stress ◽  
Zinc Deficiency ◽  
Metal Binding ◽  
Inflammatory Responses ◽  
Binding Capacity ◽  
Critical Role ◽  
Cellular Systems ◽  
Oxidative Stresses ◽  
Dual Action

Zinc is recognized as an essential trace metal required for human health; its deficiency is strongly associated with neuronal and immune system defects. Although zinc is a redox-inert metal, it functions as an antioxidant through the catalytic action of copper/zinc-superoxide dismutase, stabilization of membrane structure, protection of the protein sulfhydryl groups, and upregulation of the expression of metallothionein, which possesses a metal-binding capacity and also exhibits antioxidant functions. In addition, zinc suppresses anti-inflammatory responses that would otherwise augment oxidative stress. The actions of zinc are not straightforward owing to its numerous roles in biological systems. It has been shown that zinc deficiency and zinc excess cause cellular oxidative stress. To gain insights into the dual action of zinc, as either an antioxidant or a prooxidant, and the conditions under which each role is performed, the oxidative stresses that occur in zinc deficiency and zinc overload in conjunction with the intracellular regulation of free zinc are summarized. Additionally, the regulatory role of zinc in mitochondrial homeostasis and its impact on oxidative stress are briefly addressed.

scholarly journals Lipotoxicity-Induced mtDNA Release Promotes Diabetic Cardiomyopathy by Activating the cGAS-STING Pathway in Obesity Related Diabetes

2021 ◽  
Author(s):  
Xiu Mei Ma ◽  
Kang Geng ◽  
Betty Yuen-Kwan Law ◽  
Peng Wang ◽  
Yue Li Pu ◽  
...  
Keyword(s):  
Mouse Model ◽  
Signaling Pathway ◽  
Diabetic Cardiomyopathy ◽  
Cell Model ◽  
Critical Role ◽  
Kidney Tissue ◽  
H9c2 Cells ◽  
Downstream Targets ◽  
Sting Pathway

Abstract Diabetic cardiomyopathy (DCM) is characterized by lipid accumulation, mitochondrial dysfunction, and aseptic inflammatory activation. Mitochondria-derived cytosolic DNA has been reported to induce inflammation by activating cyclic GMP-AMP synthase (cGAS)/the stimulator of interferon genes (STING) pathway in the adipose, liver, and kidney tissue. However, the role of cytosolic mtDNA in the progression of DCM is unclear. In this study, with an obesity-related DCM mouse model established by feeding db/db mice with a high-fat diet (HFD), we observed increased mtDNA in the cytosol and activated cGAS-STING signaling pathway during DCM, as well as the downstream targets, IRF3, NF-κB, IL-18, and IL-1β. In further study with a palmitic acid (PA)-induced lipotoxic cell model established in H9C2 cells, we revealed that the cytosolic mtDNA was resulted from PA-induced overproduction of mitochondrial ROS, which also led to the activation of the cGAS/STING system and its downstream targets. Notably, treatment of extracted mtDNA alone was sufficient to activate the cGAS-STING signaling pathway in cultured H9C2 cells. Besides, both knockdown of STING in PA-induced H9C2 cells and inhibition of STING by C-176 injection in the DCM mouse model could remarkably block the inflammation and apoptosis of cardiomyocytes. In conclusion, our study elucidated the critical role of cytosolic mtDNA-induced cGAS-STING activation in the pathogenesis of obesity-related DCM and provided preclinical validation for using a STING inhibitor as a new potential therapeutic strategy for the treatment of DCM.

scholarly journals MicroRNA-34a Inhibition of the TLR Signaling Pathway Via CXCL10 Suppresses Breast Cancer Cell Invasion and Migration

2018 ◽  
Vol 46 (3) ◽  
pp. 1286-1304 ◽  
Author(s):  
Min Xu ◽  
Dong Li ◽  
Chen Yang ◽  
Jian-Song Ji
Keyword(s):  
Breast Cancer ◽  
Signaling Pathway ◽  
Migration And Invasion ◽  
Loss Of Function ◽  
Breast Tumorigenesis ◽  
Tlr Signaling ◽  
T47d Cells ◽  
Tlr Signaling Pathway ◽  
Mcf 7

Background/Aims: Breast cancer (BC) starts as a local disease, but it can metastasize to the lymph nodes and distant organs. However, the metastatic process is still poorly understood. The mRNA microarray datasets GSE26910 and GSE33447 show that CXCL10 is up-regulated in BC, and the microRNA microarray dataset GSE38167 and a network meta-analysis of microRNA expression profile studies in human BC suggest that microRNA-34a (miR-34a) is down-regulated in BC. CXCL10 was predicted as a target of miR-34a by microRNA.org. In this study, we uncovered a CXCL10-independent mechanism by which miR-34a exerts its antimetastatic activity in BC. Methods: To investigate the clinical significance of miR-34a in BC, we collected cancer tissues and paracancerous tissues from 258 patients with BC. In addition, a series of inhibitors, mimics, and siRNAs was introduced into MCF-7 and T47D cells to validate the regulatory mechanisms by which miR-34a regulates CXCL10. Next, to better understand the pivotal role of TLR signaling pathway inhibition in MCF-7 and T47D cells, we blocked the TLR signaling pathway using OxPAPC, an antagonist of TLR signaling. Results: Among BC patients, miR-34a was down-regulated, CXCL10 was up-regulated, and the TLR signaling pathway was activated. Determination of luciferase activity revealed that CXCL10 was a target of miR-34a. Through gain- and loss-of-function studies, miR-34a was demonstrated to negatively regulate CXCL10; inhibit activation of the TLR signaling pathway; significantly suppress in vitro cell proliferation, migration, and invasion; and induce apoptosis. Conclusion: Our findings suggest that functional loss or suppression of the tumor suppressor CXCL10 due to induction of miR-34a leads to inhibition of the TLR signaling pathway during breast tumorigenesis, providing a novel target for the molecular treatment of breast malignancies.

scholarly journals NF-κB mediates lipopolysaccharide-induced alternative pre-mRNA splicing of MyD88 in mouse macrophages

2020 ◽  
Vol 295 (18) ◽  
pp. 6236-6248
Author(s):  
Frank Fang-Yao Lee ◽  
Kevin Davidson ◽  
Chelsea Harris ◽  
Jazalle McClendon ◽  
William J. Janssen ◽  
...  
Keyword(s):  
Signaling Pathway ◽  
Chronic Inflammation ◽  
Mrna Splicing ◽  
Dominant Negative ◽  
Mrna Isoforms ◽  
Inflammatory Signaling ◽  
Tlr Signaling ◽  
Tlr4 Agonist ◽  
Alternatively Spliced ◽  
Tlr Signaling Pathway

Although a robust inflammatory response is needed to combat infection, this response must ultimately be terminated to prevent chronic inflammation. One mechanism that terminates inflammatory signaling is the production of alternative mRNA splice forms in the Toll-like receptor (TLR) signaling pathway. Whereas most genes in the TLR pathway encode positive mediators of inflammatory signaling, several, including that encoding the MyD88 signaling adaptor, also produce alternative spliced mRNA isoforms that encode dominant-negative inhibitors of the response. Production of these negatively acting alternatively spliced isoforms is induced by stimulation with the TLR4 agonist lipopolysaccharide (LPS); thus, this alternative pre-mRNA splicing represents a negative feedback loop that terminates TLR signaling and prevents chronic inflammation. In the current study, we investigated the mechanisms regulating the LPS-induced alternative pre-mRNA splicing of the MyD88 transcript in murine macrophages. We found that 1) the induction of the alternatively spliced MyD88 form is due to alternative pre-mRNA splicing and not caused by another RNA regulatory mechanism, 2) MyD88 splicing is regulated by both the MyD88- and TRIF-dependent arms of the TLR signaling pathway, 3) MyD88 splicing is regulated by the NF-κB transcription factor, and 4) NF-κB likely regulates MyD88 alternative pre-mRNA splicing per se rather than regulating splicing indirectly by altering MyD88 transcription. We conclude that alternative splicing of MyD88 may provide a sensitive mechanism that ensures robust termination of inflammation for tissue repair and restoration of normal tissue homeostasis once an infection is controlled.

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