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Objective: Chronic atrophic gastritis (CAG) is a complex and burdensome disease. However, side effects and compliance issues cannot be ignored due to the long treatment cycle. Numerous studies have confirmed the effectiveness of rutaecarpine (RUT) for treating digestive dysfunction. However, the potential mechanism of action of RUT in the context of CAG treatment remains unclear. This study aimed to explore the therapeutic effects and mechanisms of RUT in 1-methyl-3-nitro-1-nitrosoguanidine-induced CAG using network pharmacology, metabolomics, and traditional pharmacological approaches. Materials and Methods: Pathological tests and ELISA assays were used to observe the therapeutic effects of RUT treatment on CAG. Differential metabolites were identified using ultra-high-performance liquid chromatography-tandem mass spectrometry, and metabolism-related target genes were enriched. The same target genes were identified between RUT and CAG diseases. The intersectional target genes were uploaded to Cytoscape for enrichment, and the nucleotide-binding oligomerization domain (NOD)-like receptor signaling pathway was selected to validate the mechanisms of the study. Finally, cell pyroptosis status was evaluated using the terminal deoxynucleotidyl transferase-mediated dUTP nick end labeling assay, and the expressions of associated proteins of the NOD-like receptor signaling pathway were assessed by Western blotting and immunohistochemistry. Results: RUT alleviated gastric mucosal damage and significantly downregulated indicators associated with inflammation and gastric atrophy. A total of 29 intersection target genes was identified, and core pathways were obtained. The NOD-like receptor signaling pathway and pyroptosis status were selected to validate the mechanisms of RUT treatment in CAG rats. The expression of NOD-related proteins and downstream factors was downregulated in the RUT group. Conclusions: RUT exerts a pharmacological effect on relieving gastric damage in CAG rats by inhibiting NOD-like receptors and inflammasomes.

Background and Objective: Diabetes influences the frequency and development of periodontitis. Inflammation of human periodontal ligament cells (HPDLCs) participates in this pathologic process. Hence, this study aims to explore whether advanced glycation end products (AGEs), by‐products of diabetes, could exaggerate inflammation induced by muramyl dipeptide (MDP) in HPDLCs, and whether nucleotide‐binding oligomerization domain‐like receptors (NLRs) signaling pathway was involved. Material and Methods: Human periodontal ligament cells were pre‐treated with 100 μg/mL AGEs for 24 hours and stimulated with 10 μg/mL MDP for 24 hours. IL‐6, IL‐1β, and RAGE were detected, and the activation of NF‐κB signaling pathway was observed. The expression of NLRs was evaluated with or without silencing RAGE or blocking NF‐κB pathway under AGEs stimulation. Statistical analyses were performed by using independent sample t test. Results: Advanced glycation end products induced significant increase of inflammatory cytokines in HPDLCs (P < 0.05). Results of western blot (WB) showed that after 45 minutes stimulation of AGEs, p‐p65/p65 ratio peaked; AGEs promoted the expression of NLRP1, NLRP3, and apoptosis‐associated speck‐like protein containing a CARD (ASC). After silencing RAGE or blocking NF‐κB pathway, the up‐regulation of NLRs protein caused by AGEs was attenuated. Additionally, AGEs pre‐treatment could enhance the inflammatory response of MDP and the expression of NLRs, which were demonstrated by more expression of IL‐6, IL‐1β, NOD2, NLRP1, NLRP3, and ASC. Conclusion: Advanced glycation end products induced inflammatory response in HPDLCs via NLRP1‐inflammasome and NLRP3‐inflammasome activation in which NF‐κB signal pathway was involved. Besides, AGEs promoted the inflammatory response of MDP via NOD2, NLRP1‐inflammasome, and NLRP3‐inflammasome. [ABSTRACT FROM AUTHOR]

Aim: The active domains (TIR and NACHT) of the pattern recognition receptors (PRRs: Toll-like receptors [TLRs] and nucleotide-binding oligomerization domain [NOD]-like receptors [NLR], respectively) are the major hotspots of evolution as natural selection has crafted their final structure by substitution of residues over time. This paper addresses the evolutionary perspectives of the TLR and NLR genes with respect to the active domains in terms of their chronological fruition, functional diversification, and species-specific stipulation. Materials and Methods: A total of 48 full-length cds (and corresponding peptide) of the domains were selected as representatives of each type of PRRs, belonging to divergent animal species, for the biocomputational analyses. The secondary and tertiary structure of the taurine TIR and NACHT domains was predicted to compare the relatedness among the domains under study. Results: Multiple sequence alignment and phylogenetic tree results indicated that these host-specific PRRs formed entirely different clusters, with active domains of NLRs (NACHT) evolved earlier as compared to the active domains of TLRs (TIR). Each type of TLR or NLR shows comparatively less variation among the animal species due to the specificity of action against the type of microbes. Conclusion: It can be concluded from the study that there has been no positive selection acting on the domains associated with disease resistance which is a fitness trait indicating the extent of purifying pressure on the domains. Gene duplication could be a possible reason of genesis of similar kinds of TLRs (virus or bacteria specific).

Summary: Formation of supramolecular assemblies appears to be a general mechanism in immune signalling pathways. These supramolecular assemblies appear to form through a nucleated polymerization mechanism. This review examines selected immune signalling pathways that involve supramolecular assemblies, describes the concepts of protein polymerization, and discusses how those concepts of protein polymerization implicate new elegant ways for signal amplification, setting threshold and noise reduction in these pathways. Formation of supramolecular assemblies appears to be a general mechanism in immune signalling pathways. This review examines selected immune signalling pathways that involve supramolecular assemblies, describes the concepts of protein polymerization, and discusses how those concepts may implicate new molecular mechanisms in signal transduction. [ABSTRACT FROM AUTHOR]

Traumatic brain injury (TBI), an acquired brain injury imparted by a mechanical trauma to the head, has significant ramifications in terms of long-term disability and cost of healthcare. TBI is characterized by an initial phase of cell death owing to direct mechanical injury, followed by a secondary phase in which neuroinflammation plays a pivotal role. Activation of inflammasome complexes triggers a cascade that leads to activation of inflammatory mediators such as caspase-1, Interleukin (IL)-18, and IL-1β, eventually causing pyroptosis. NLRP3 inflammasome, a component of the innate immune response, has been implicated in a number of neurodegenerative diseases, including TBI. Recent findings indicate that NLRP3 inhibitors can potentially ameliorate neuroinflammation and improve cognition and motor function in TBI. The NLRP3 inflammasome also holds potential as a predictive biomarker for the long-term sequelae following TBI. Although several therapeutic agents have shown promising results in pre-clinical studies, none of them have been effective in human trials for TBI, to date. Thus, it is imperative that such promising therapeutic candidates are evaluated in clinical trials to assess their efficacy in alleviating neurological impairments in TBI. This review offers an insight into the pathophysiology of TBI, with an emphasis on neuroinflammation in the aftermath of TBI. We highlight the NLRP3 inflammasome and explore its role in the neuroinflammatory cascade in TBI. We also shed light on its potential as a prospective biomarker and therapeutic target for TBI management. [Display omitted] • Traumatic brain injury (TBI) is an acquired brain injury induced by an external trauma to the head. • Despite causing high mortality rates and significant healthcare costs, there exists no effective therapy for TBI. • NLRP3 inflammasome triggers the activation of several inflammatory mediators like caspase-1, IL-18, and IL-1β. • Recent findings indicate that NLRP3 inhibitors can potentially ameliorate neuroinflammation in the wake of TBI. • NLRP3 inflammasome also holds potential as a predictive biomarker for the long-term sequelae following TBI. [ABSTRACT FROM AUTHOR]

Aim: The active domains (TIR and NACHT) of the pattern recognition receptors (PRRs: Toll-like receptors [TLRs] and nucleotide-binding oligomerization domain [NOD]-like receptors [NLR], respectively) are the major hotspots of evolution as natural selection has crafted their final structure by substitution of residues over time. This paper addresses the evolutionary perspectives of the TLR and NLR genes with respect to the active domains in terms of their chronological fruition, functional diversification, and species-specific stipulation. Materials and Methods: A total of 48 full-length cds (and corresponding peptide) of the domains were selected as representatives of each type of PRRs, belonging to divergent animal species, for the biocomputational analyses. The secondary and tertiary structure of the taurine TIR and NACHT domains was predicted to compare the relatedness among the domains under study. Results: Multiple sequence alignment and phylogenetic tree results indicated that these host-specific PRRs formed entirely different clusters, with active domains of NLRs (NACHT) evolved earlier as compared to the active domains of TLRs (TIR). Each type of TLR or NLR shows comparatively less variation among the animal species due to the specificity of action against the type of microbes. Conclusion: It can be concluded from the study that there has been no positive selection acting on the domains associated with disease resistance which is a fitness trait indicating the extent of purifying pressure on the domains. Gene duplication could be a possible reason of genesis of similar kinds of TLRs (virus or bacteria specific). [ABSTRACT FROM AUTHOR]

Lower respiratory tract infections (LRTIs) are a persistent and pervasive public health problem worldwide. Pneumonia and other LRTIs will be among the leading causes of death in adults, and pneumonia is the single largest cause of death in children. LRTIs are also an important cause of acute lung injury and acute exacerbations of chronic obstructive pulmonary disease. Because innate immunity is the first line of defense against pathogens, understanding the role of innate immunity in the pulmonary system is of paramount importance. Pattern recognition molecules (PRMs) that recognize microbial-associated molecular patterns are an integral component of the innate immune system and are located in both cell membranes and cytosol. Toll-like receptors and nucleotide-binding oligomerization domain-like receptors (NLRs) are the major sensors at the forefront of pathogen recognition. Although Toll-like receptors have been extensively studied in host immunity, NLRs have diverse and important roles in immune and inflammatory responses, ranging from antimicrobial properties to adaptive immune responses. The lung contains NLR-expressing immune cells such as leukocytes and nonimmune cells such as epithelial cells that are in constant and close contact with invading microbes. This pulmonary perspective addresses our current understanding of the structure and function of NLR family members, highlighting advances and gaps in knowledge, with a specific focus on immune responses in the respiratory tract during bacterial infection. Further advances in exploring cellular and molecular responses to bacterial pathogens are critical to develop improved strategies to treat and prevent devastating infectious diseases of the lung. [ABSTRACT FROM AUTHOR]

Cardiovascular diseases (CVDs) are the leading cause of death in the industrialized world. Most CVDs are associated with increased inflammation that arises mainly from innate immune system activation related to cardiac damage. Sustained activation of the innate immune system frequently results in maladaptive inflammatory responses that promote cardiovascular dysfunction and remodeling. Much research has focused on determining whether some mediators of the innate immune system are potential targets for CVD therapy. The innate immune system has specific receptors-termed pattern recognition receptors (PRRs)-that not only recognize pathogen-associated molecular patterns, but also sense danger-associated molecular signals. Activation of PRRs triggers the inflammatory response in different physiological systems, including the cardiovascular system. The classic PRRs, toll-like receptors (TLRs), and the more recently discovered nucleotide-binding oligomerization domain-like receptors (NLRs), have been recently proposed as key partners in the progression of several CVDs (e.g., atherosclerosis and heart failure). The present review discusses the key findings related to the involvement of TLRs and NLRs in the progression of several vascular and cardiac diseases, with a focus on whether some NLR subtypes (nucleotide-binding oligomerization domain, leucine rich repeat and pyrin domain-containing receptor 3 and nucleotide-binding oligomerization domain-containing protein 1) can be candidates for the development of new therapeutic strategies for several CVDs., (© 2020 The Authors.)