MCL Plays an Anti-Inflammatory Role in Mycobacterium tuberculosis-Induced Immune Response by Inhibiting NF-κB and NLRP3 Inflammasome Activation

Role of pattern recognition receptors in sensing Mycobacterium tuberculosis

Mycobacterium tuberculosis is one of the major invasive intracellular pathogens causing most deaths by a single infectious agent. The interaction between host immune cells and this pathogen is the focal point of the disease, Tuberculosis. Host immune cells not only mount the protective action against this pathogen but also serve as the primary niche for growth. Thus, recognition of this pathogen by host immune cells and following signaling cascades are key dictators of the disease state. Immune cells, mainly belonging to myeloid cell lineage, recognize a wide variety of Mycobacterium tuberculosis ligands ranging from carbohydrate and lipids to proteins to nucleic acids by different membrane-bound and soluble pattern recognition receptors. Simultaneous interaction between different host receptors and pathogen ligands leads to immune-inflammatory response as well as contributes to virulence. This review summarizes the contribution of pattern recognition receptors of host immune cells in recognizing Mycobacterium tuberculosis and subsequent initiation of signaling pathways to provide the molecular insight of the specific Mtb ligands interacting with specific PRR, key adaptor molecules of the downstream signaling pathways and the resultant effector functions which will aid in identifying novel drug targets, and developing novel drugs and adjuvants.

Fraxinol attenuates LPS-induced acute lung injury by equilibrating ACE-Ang II-AT1R and ACE2-Ang (1-7)-Mas and inhibiting NLRP3

CONTEXT

Acute lung injury (ALI) is a serious heterogenous pulmonary disorder. Fraxinol was selected for this study since it is a simple coumarin compound, not previously investigated in ALI.

OBJECTIVES

This study investigates the ALI therapeutic effect and mechanisms of fraxinol.

MATERIALS AND METHODS

Male BALB/c mice were treated with fraxinol (20, 40, and 80 mg/kg) following intranasal injection of lipopolysaccharide (LPS; 10 μg in 50 μL). The mice in control group were intratracheally injected with 50 μL phosphate buffered saline (PBS). Raw264.7 cells were treated with fraxinol by 100 ng/mL LPS for 6 h, then treated by different concentrations of fraxinol (5, 10, and 25 μM) for 48 h. Cells in control group were treated with PBS.

RESULTS

Fraxinol with doses of 20, 40, and 80 mg/kg significantly attenuated LPS-induced lung injury in mice (lung injury score, 10.4, 31.2, 50.3%). Fraxinol attenuated the apoptosis and nucleotide-binding oligomerization domain-like receptor family pyrin domain-containing-3 (NLRP3) activation induced by LPS (apoptosis, 18.3, 30.2, 55.6%; NLRP3, 30.0, 47.7, 63.6%). The anti-apoptosis and anti-inflammation effects of fraxinol were also confirmed in Raw264.7 cells (apoptosis, 38.8, 55.3, 68.9%; NLRP3, 20.6, 55.7, 73.9%).

DISCUSSION AND CONCLUSION

The anti-ALI effects of fraxinol maybe by equilibrating ACE-Ang II-AT1R and ACE2-Ang (1-7)-Mas axis and inhibiting NLRP3 inflammasome. Our research provides a candidate drug in the treatment of ALI.

microRNAs associated with the pathogenesis and their role in regulating various signaling pathways during Mycobacterium tuberculosis infection

Despite more than a decade of active study, tuberculosis (TB) remains a serious health concern across the world, and it is still the biggest cause of mortality in the human population. Pathogenic bacteria recognize host-induced responses and adapt to those hostile circumstances. This high level of adaptability necessitates a strong regulation of bacterial metabolic characteristics. Furthermore, the immune reponse of the host virulence factors such as host invasion, colonization, and survival must be properly coordinated by the pathogen. This can only be accomplished by close synchronization of gene expression. Understanding the molecular characteristics of mycobacterial pathogenesis in order to discover therapies that prevent or resolve illness relies on the bacterial capacity to adjust its metabolism and replication in response to various environmental cues as necessary. An extensive literature details the transcriptional alterations of host in response to in vitro environmental stressors, macrophage infection, and human illness. Various studies have recently revealed the finding of several microRNAs (miRNAs) that are believed to play an important role in the regulatory networks responsible for adaptability and virulence in Mycobacterium tuberculosis. We highlighted the growing data on the existence and quantity of several forms of miRNAs in the pathogenesis of M. tuberculosis, considered their possible relevance to disease etiology, and discussed how the miRNA-based signaling pathways regulate bacterial virulence factors.

The licorice flavonoid isoliquiritigenin attenuates Mycobacterium tuberculosis-induced inflammation through Notch1/NF-κB and MAPK signaling pathways

ETHNOPHARMACOLOGICAL RELEVANCE

The genus Glycyrrhiza is a small perennial herb that has been traditionally used to treat many diseases across the world. Licorice (Gancao in Chinese) is the dried root and rhizome of G. glabra, G. uralensis or G. inflata. Licorice plays an important role in traditional Chinese medicine (TCM), and is the most frequently used in Chinese herbal formulas. Isoliquiritigenin (ISL) is a flavonoid extracted from licorice, and has been evaluated for its various biological activities, including anti-inflammatory, anti-tumor and anti-oxidant activities. Excessive and persistent inflammation in the Mycobacterium tuberculosis (Mtb) infection is not conducive to the elimination of Mtb, but contributes to serious pulmonary dysfunction.

AIM OF THE STUDY

This study aimed to examine the anti-inflammatory effects of ISL in the Mtb infection.

METHODS

In vitro models of Mtb-infected macrophages were established. Murine macrophage Raw 264.7 cells and primary peritoneal macrophages were used in this study. Cell viability was determined by the cell counting kit-8 (CCK-8) assay. The effects of ISL on the secretion levels of interleukin -1β (IL-1β), tumor necrosis factor -α (TNF-α), and interleukin -6 (IL-6) were detected by the enzyme-linked immunosorbent assay (ELISA). The expression levels of inducible nitric oxide synthase (iNOS) and cyclooxygenase-2 (COX2) were measured by the real time quantitative reverse transcription polymerase chain reaction (RT-qPCR) and Western blot. Western blot was used to assess the effects of ISL on the activation of NLRP3 inflammasome and Notch1/NF-κB and MAPK signaling pathways. Immunofluorescence assays was used to detected the translocation of phosphorylation of p65 subunit of NF-κB.

RESULTS

It was revealed that ISL inhibited the secretion of IL-1β and the activation of pore-forming protein (gasdermin D, GSDMD) by suppressing the activation of NLPR3 inflammasome induced by Mtb infection. ISL was also shown to have promising inhibitory effects on inflammatory factors, such as TNF-α, IL-6, iNOS and COX2. Regarding the anti-inflammatory mechanism of ISL, it was found that ISL exerted its anti-inflammatory effects by inhibiting the activation of Notch1/NF-κB and MAPK signaling pathways.

CONCLUSION

ISL reduced Mtb-induced inflammation through the Notch1/NF-κB and MAPK signaling pathways. ISL might be used as a potential adjuvant drug to treat tuberculosis by adjusting host immune responses.

Lnc-EST12, which is negatively regulated by mycobacterial EST12, suppresses antimycobacterial innate immunity through its interaction with FUBP3

Long noncoding RNAs (lncRNAs) have been implicated in the pathogenesis of intracellular pathogens. However, the role and mechanism of the important lncRNAs in Mycobacterium tuberculosis (M.tb) infection remain largely unexplored. Recently, we found that a secreted M.tb Rv1579c (an early secreted target with a molecular weight of 12 kDa, named EST12) protein activates NLRP3-gasdermin D (GSDMD)-mediated pyroptosis and plays a pivotal role in M.tb-induced immunity. In the present study, M.tb and the EST12 protein negatively regulated the expression of a key lncRNA (named lnc-EST12) in mouse macrophages by activating the JAK2-STAT5a signaling pathway. Lnc-EST12, with a size of 1583 bp, is mainly expressed in immune-related organs (liver, lung and spleen). Lnc-EST12 not only reduces the expression of the proinflammatory cytokines IL-1β, IL-6, and CCL5/8 but also suppresses the NLRP3 inflammasome and GSDMD pyroptosis-IL-1β immune pathway through its interaction with the transcription factor far upstream element-binding protein 3 (FUBP3). The KH3 and KH4 domains of FUBP3 are the critical sites for binding to lnc-EST12. Deficiency of mouse lnc-EST12 or FUBP3 in macrophages increased M.tb clearance and inflammation in mouse macrophages or mice. In conclusion, we report a new immunoregulatory mechanism in which mouse lnc-EST12 negatively regulates anti-M.tb innate immunity through FUBP3.

Sesquiterpene Lactones and Cancer: New Insight into Antitumor and Anti-inflammatory Effects of Parthenolide-Derived Dimethylaminomicheliolide and Micheliolide

Applied science nowadays works on the isolation and application of biological macromolecules (BMM). These BMM are isolates from plants using different techniques and used as anticancer, antimicrobial, and anti-inflammatory drugs. Parthenolide (PLT) is one of the most important biological macromolecules and a naturally occurring sesquiterpene lactone that is isolated from a plant species Tanacetum parthenium (T. parthenium). The anti-cancer and anti-inflammatory effects of PTL isolated from T. parthenium were previously reported and summarized in detail. These biological activities make it a vital candidate for further researches and drugs development. As per the previously obtained findings, the sesquiterpene is very much known for some biological activities; therefore, the anti-cancer and anti-inflammatory activities of the sesquiterpene were critically reviewed. During the research process, PTL was found to be unstable in both acidic and basic conditions with low solubility, so structurally related compounds micheliolide (MCL) and Dimethylaminomicheliolide (DMAMCL) (a prodrug of MCL) were developed. In this article, we briefly review the therapeutic effects of PTL and its derivative DMAPT on inflammatory diseases and tumors, focusing on the current application of PTL in targeted therapy and combination therapy, together with anti-inflammatory and anti-tumor functions of MCL and DMAMCL. The uniqueness of this biological macromolecule is not to harm the normal cell but target the cancerous cells. Therefore, the current literature review might be helpful and useful for prospects based on the effects of MCL and DMAMCL on cancer.

Interaction of Mycobacteria With Host Cell Inflammasomes

The inflammasome complex is important for host defense against intracellular bacterial infections. Mycobacterium tuberculosis (Mtb) is a facultative intracellular bacterium which is able to survive in infected macrophages. Here we discuss how the host cell inflammasomes sense Mtb and other related mycobacterial species. Furthermore, we describe the molecular mechanisms of NLRP3 inflammasome sensing of Mtb which involve the type VII secretion system ESX-1, cell surface lipids (TDM/TDB), secreted effector proteins (LpqH, PPE13, EST12, EsxA) and double-stranded RNA acting on the priming and/or activation steps of inflammasome activation. In contrast, Mtb also mediates inhibition of the NLRP3 inflammasome by limiting exposure of cell surface ligands via its hydrolase, Hip1, by inhibiting the host cell cathepsin G protease via the secreted Mtb effector Rv3364c and finally, by limiting intracellular triggers (K+ and Cl- efflux and cytosolic reactive oxygen species production) via its serine/threonine kinase PknF. In addition, Mtb inhibits the AIM2 inflammasome activation via an unknown mechanism. Overall, there is good evidence for a tug-of-war between Mtb trying to limit inflammasome activation and the host cell trying to sense Mtb and activate the inflammasome. The detailed molecular mechanisms and the importance of inflammasome activation for virulence of Mtb or host susceptibility have not been fully investigated.

Exploring the Use of Medicinal Plants and Their Bioactive Derivatives as Alveolar NLRP3 Inflammasome Regulators during Mycobacterium tuberculosis Infection

Mycobacterium tuberculosis, the causative agent of tuberculosis (TB), is a successful intracellular pathogen that is responsible for the highest mortality rate among diseases caused by bacterial infections. During early interaction with the host innate cells, M. tuberculosis cell surface antigens interact with Toll like receptor 4 (TLR4) to activate the nucleotide-binding domain, leucine-rich-repeat containing family, pyrin domain-containing 3 (NLRP3) canonical, and non-canonical inflammasome pathways. NLRP3 inflammasome activation in the alveoli has been reported to contribute to the early inflammatory response that is needed for an effective anti-TB response through production of pro-inflammatory cytokines, including those of the Interleukin 1 (IL1) family. However, overstimulation of the alveolar NLRP3 inflammasomes can induce excessive inflammation that is pathological to the host. Several studies have explored the use of medicinal plants and/or their active derivatives to inhibit excessive stimulation of the inflammasomes and its associated factors, thus reducing immunopathological response in the host. This review describes the molecular mechanism of the NLRP3 inflammasome activation in the alveoli during M. tuberculosis infection. Furthermore, the mechanisms of inflammasome inhibition using medicinal plant and their derivatives will also be explored, thus offering a novel perspective on the alternative control strategies of M. tuberculosis-induced immunopathology.

Immune status changing helps diagnose osteoarticular tuberculosis

Objective

This study is aimed to develop a new nomogram for the clinical diagnosis of osteoarticular tuberculosis (TB).

Methods

xCell score estimation to obtained the immune cell type abundance scores. We downloaded the expression profile of GSE83456 from GEO and proceed xCell score estimation. The routine blood examinations of 326 patients were collected for further validation. We analyzed univariate and multivariate logistic regression to identified independent predicted factor for developing the nomogram. The performance of the nomogram was assessed using the receiver operating characteristic (ROC) curves. The correlation of ESR with lymphocytes, monocytes, and ML ratio was performed and visualized in osteoarticular TB patients.

Results

Compared with the healthy control group in the dataset GSE83456, the xCell score of basophils, monocytes, neutrophils, and platelets was higher, while lymphoid was lower in the EPTB group. The clinical data showed that the cell count of monocytes were much higher, while the cell counts of lymphocytes were lower in the osteoarticular TB group. AUCs of the nomogram was 0.798 for the dataset GSE83456, and 0.737 for the clinical data. We identified the ML ratio, BMI, and ESR as the independent predictive factors for osteoarticular TB diagnosis and constructed a nomogram for the clinical diagnosis of osteoarticular TB. AUCs of this nomogram was 0.843.

Conclusions

We demonstrated a significant change between the ML ratio of the EPTB and non-TB patients. Moreover, we constructed a nomogram for the clinical diagnosis of the osteoarticular TB diagnosis, which works satisfactorily.

Recombinant Rv1654 protein of Mycobacterium tuberculosis induces mitochondria-mediated apoptosis in macrophage

Mycobacterium tuberculosis contains diverse immunologically active components. This study investigated the biological function of a newly identified component, Rv1654, with the potential to induce apoptosis in macrophages. Recombinant Rv1654 induced macrophage apoptosis in a caspase-9/3-dependent manner through the production of reactive oxygen species (ROS) and interaction with Toll-like receptor 4. In addition, Rv1654 induced the production of tumor necrosis factor-α, interleukin-6, and monocyte chemoattractant protein-1 through the mitogen-activated protein kinase pathway. Furthermore, Rv1654-induced c-Jun N-terminal kinase (JNK) activation was inhibited by the ROS scavenger and Rv1654-induced apoptosis was inhibited by the JNK inhibitor. Moreover, it was found that treatment of macrophages with Rv1654 led to the loss of mitochondrial membrane potential, release of cytochrome c into the cytosol, and translocation of Bax into the mitochondria. Finally, Rv1654-mediated apoptosis was inhibited in macrophages transfected with Bax siRNA. These results suggest that Rv1654 induces macrophage apoptosis through a mitochondrial-dependent pathway and ROS-mediated JNK activation.

The Roles of Inflammasomes in Host Defense against Mycobacterium tuberculosis

Mycobacterium tuberculosis (MTB) infection is characterized by granulomatous lung lesions and systemic inflammatory responses during active disease. Inflammasome activation is involved in regulation of inflammation. Inflammasomes are multiprotein complexes serving a platform for activation of caspase-1, which cleaves the proinflammatory cytokines such as interleukin-1β (IL-1β) and IL-18 into their active forms. These cytokines play an essential role in MTB control. MTB infection triggers activation of the nucleotide-binding domain, leucine-rich-repeat containing family, pyrin domain-containing 3 (NLRP3) and absent in melanoma 2 (AIM2) inflammasomes in vitro, but only AIM2 and apoptosis-associated speck-like protein containing a caspase-activation recruitment domain (ASC), rather than NLRP3 or caspase-1, favor host survival and restriction of mycobacterial replication in vivo. Interferons (IFNs) inhibits MTB-induced inflammasome activation and IL-1 signaling. In this review, we focus on activation and regulation of the NLRP3 and AIM2 inflammasomes after exposure to MTB, as well as the effect of inflammasome activation on host defense against the infection.

Elucidation of the Mechanisms and Molecular Targets of Shuanglian Decoction for the Treatment of Hepatocellular Carcinoma Based on Network Pharmacology

Shuanglian decoction (SLD) is traditionally used to treat hepatocellular carcinoma (HCC) in the clinical practice of traditional Chinese medicine. However, its mechanisms of action and molecular targets for the treatment of HCC are not clear. The active compounds of SLD were collected and their targets were identified. HCC-related targets were obtained by analyzing the differentially expressed genes between HCC patients and healthy individuals. Protein-protein interaction (PPI) data were then obtained and PPI networks of SLD putative targets and HCC-related targets were visualized and merged to identify the candidate targets for SLD against HCC. Gene ontology and Kyoto Encyclopedia of Genes and Genomes pathway analysis were carried out. The gene-pathway network was constructed to screen the key target genes. In total, 35 active compounds and 31 targets of SLD were identified. In total, 245 differentially expressed genes with P values <0.005 and |log2 (fold change)| > 1 were identified between HCC patients and control groups, and 68 target genes associated with HCC were finally identified. Twenty-one pathways including cellular senescence, p53 signaling pathway, and cell cycle were significantly enriched. CYP3A4 was the core gene and other several genes including CYP1A2, PPP3CA, PTGS2, CCCNB1, and CDK1 were the key genes in the gene-pathway network of SLD for the treatment of HCC. The results indicated that SLD's effects against HCC may relate to the regulation of an antioxidant function through specific biological processes and related pathways. This study demonstrates the application of network pharmacology in evaluating mechanisms of action and molecular targets of complex herbal formulations.

Anti-mycobacterial and anti-inflammatory activity of restinga plants: a dual approach in searching for new drugs to treat severe tuberculosis

Abstract Tuberculosis (TB) still constitutes a threat to public health in various regions of the world. The existing treatment is long and has many side effects. The need to identify new anti-TB compounds and also adjuvants to control exacerbated inflammation in severe TB cases is relevant. Therefore, the objective of this study was to evaluate the anti-mycobacterial activity of extracts and fractions in vitro from plant species collected in the Restinga of Jurubatiba, in Rio de Janeiro state, Brazil. In addition, to verify their immunomodulatory action and cytotoxicity on macrophages. The dichloromethane fraction of Kielmeyera membranacea and Eremanthus crotonoides showed the lowest MIC50 against Mycobacterium bovis BCG (0.95 ± 1.08 and 2.17 ± 1.11 μg/mL, respectively) and M. tuberculosis H37Rv (4.38 ± 1.19 and 15.28 ± 1.21 μg/mL, respectively). They were also able to inhibit the NO and TNF-α production in LPS-stimulated macrophages, without being toxic to cells. Using gas chromatography analysis coupled with mass spectrometer it was possible to suggest the presence of fatty acids and terpenes in the most promising fractions. Those compounds have been described for their anti-mycobacterial activity. These results have enabled identifying Kielmeyera membranacea and Eremanthus crotonoides as the most promising studied species in searching for new anti-TB compounds with dual activity.

Network Pharmacology Study of the Hepatoprotective Effects of Quercetin-Containing Traditional Chinese Medicine, Anoectochilus roxburghii, and Validation of Quercetin as an Anti-Liver Injury Agent in a Mouse Model of Liver Injury

Background

Anoectochilus roxburghii (Orchidaceae) (AR) has been widely used to treat liver injury in China, but its underlying mechanisms remain elusive. Network pharmacology was utilized to assess the hepatoprotective effects of quercetin (Que)-containing AR, and to validate the anti-liver injury effects of Que in a mouse model of liver injury.

Material/Methods

Network pharmacology analysis was performed to determine bio-active compounds in AR. The core therapeutic targets of AR against liver injury were identified using a protein–protein interaction network. Biological function and pathway enrichment were analyzed based on the identified core therapeutic targets. The hepatoprotective effects of Que in a mouse model of liver injury induced by CCl₄ were assessed to verify the reliability of network pharmacology analysis.

Results

Seven bio-active compounds of AR met drug screening criteria and 17 core therapeutic targets of AR against liver injury were identified. Biological function analysis demonstrated that the therapeutic effects of AR against liver injury were chiefly associated with the suppression of inflammation and immunity; and pathway enrichment analysis showed that nuclear factor-kappa B (NF-κB) and tumor necrosis factor (TNF) signaling pathways were associated with the inflammatory responses. Experimental validation in a mouse model showed that AR exerted anti-inflammatory effects by regulating the NF-κB signaling pathway, a finding that also confirmed the reliability of network pharmacology analysis.

Conclusions

The bio-active compounds identified in AR and the elucidation of their mechanisms of action against liver injury provide a theoretical basis for designing agents that can prevent or suppress liver injury.

Mycobacterium tuberculosis-Secreted Protein, ESAT-6, Inhibits Lipopolysaccharide-Induced MMP-9 Expression and Inflammation Through NF-κB and MAPK Signaling in RAW 264.7 Macrophage Cells

-20pt?>Mycobacterium tuberculosis (Mtb) is a pathogenic bacterium that causes contagious tuberculosis (TB). Recently, Mtb-secreted proteins have been considered virulence factors and candidates for drugs and vaccines. Among these proteins, 6-kDa early secreted antigenic target (ESAT-6) is known to be able to induce component of matrix metalloproteinase-9 (MMP-9) in epithelial cells, leading to recruitment of macrophages. However, detailed function of ESAT-6 during macrophage recruitment to inflammatory sites remains unknown. Thus, the objective of the present study was to elucidate such function of EAST-6 and mechanism(s) involved. In the present study, we have found that recombinant ESAT-6 purified in the form of ESAT-6 double-connected structure (2E6D) could inhibit lipopolysaccharide (LPS)-induced potential of cell migration and inflammation in murine macrophage cells. Interestingly, 2E6D suppressed LPS-induced MMP-9 expression at both protein and mRNA levels as well as its enzyme activity. Levels of cyclooxygenase-2 (COX-2) and inducible nitric oxide synthase (iNOS) enzymes as known upregulators of MMP-9 were significantly decreased when 2E6D has been treated. In addition, nitric oxide (NO) as a second messenger was also significantly decreased by treatment with the purified 2E6D. Furthermore, 2E6D inhibited LPS-induced phosphorylation of IκB and translocation of NF-κB. Moreover, 2E6D suppressed phosphorylation of MAPK signaling proteins. Taken together, these results suggest that ESAT-6 can suppress LPS-induced MMP-9 and inflammation by downregulating COX-2, iNOS, and NO through NF-κB and MAPK signaling.

Micheliolide alleviates ankylosing spondylitis (AS) by suppressing the activation of the NLRP3 inflammasome and maintaining the balance of Th1/Th2 via regulating the NF-κB signaling pathway

Background

Ankylosing spondylitis (AS) is a common form of inflammatory arthritis. Micheliolide (MCL), a sesquiterpene lactone, is reportedly involved in the alleviation of inflammatory response. This study aimed to investigate the mechanism of MCL in the treatment of AS.

Methods

Mice were randomly divided into five groups: the sham group, the MCL (50 mg/kg) group, the AS model group, the AS + MCL (20 mg/kg) group, and the AS + MCL (50 mg/kg) group. After the addition of the inhibitor celastrol, mice were randomly divided into five groups: the sham group, the AS model group, the AS + MCL (50 mg/kg) group, the AS + Celastrol (1 mg/kg) group, and the AS + Celastrol (1 mg/kg) + MCL (50 mg/kg) group.

Results

Compared with the AS model mice, the protein expression levels of tumor necrosis factor-α (TNF-α), interleukin (IL)-1β, IL-6, and IL-18 were decreased after MCL treatment. The protein expression levels of capase-1 p10, IL-1β p17, NOD-like receptor family and pyrin domain containing 3 (NLRP3), caspase-1, and apoptosis-associated speck-like protein (ASC) were also reduced. The protein expression levels of Interferon (IFN)-γ were down-regulated, but levels of IL-4 were increased. Western blotting and immunohistochemistry revealed that the levels of p-IκB α were up-regulated, while the levels of phosphorylated-p65 were down-regulated. After the addition of celastrol, MCL treatment significantly reduced the levels of p-p65, NLRP3, caspase-1, and ASC. Meanwhile, the levels of IFN-γ were markedly down-regulated, but the levels of IL-4 were enhanced.

Conclusions

Our study found that MCL suppressed the activation of NLRP3 inflammasome and maintained the balance of Th1/Th2 via regulating NF-κB signaling. Therefore, MCL could potentially be used to treat AS.

HMGN2 regulates non-tuberculous mycobacteria survival via modulation of M1 macrophage polarization

Non‐tuberculous mycobacteria (NTM), also known as an environmental and atypical mycobacteria, can cause the chronic pulmonary infectious diseases. Macrophages have been suggested as the main host cell to initiate the innate immune responses to NTM infection. However, the molecular mechanism to regulate the antimicrobial immune responses to NTM is still largely unknown. Current study showed that the NTM clinical groups, Mycobacterium abscessus and Mycobacterium smegmatis, significantly induced the M1 macrophage polarization with the characteristic production of nitric oxide (NO) and marker gene expression of iNOS, IFNγ, TNF‐α, IL1‐β and IL‐6. Interestingly, a non‐histone nuclear protein, HMGN2 (high‐mobility group N2), was found to be spontaneously induced during NTM‐activated M1 macrophage polarization. Functional studies revealed that HMGN2 deficiency in NTM‐infected macrophage promotes the expression of M1 markers and the production of NO via the enhanced activation of NF‐κB and MAPK signalling. Further studies exhibited that HMGN2 knock‐down also enhanced IFNγ‐induced M1 macrophage polarization. Finally, we observed that silencing HMGN2 affected the survival of NTM in macrophage, which might largely relevant to enhanced macrophage polarization into M1 phenotype under the NTM infection. Collectively, current studies thus suggested a novel function of HMGN2 in regulating the anti‐non‐tuberculous mycobacteria innate immunity of macrophage.

Dimethylaminomicheliolide ameliorates peritoneal fibrosis through the activation of autophagy

Peritoneal fibrosis (PF) is a major cause of ultrafiltration failure in patients receiving long-term peritoneal dialysis (PD), and effective prevention and treatment strategies are urgently needed. The dimethylamino Michael adduct of a natural product-derived micheliolide (MCL), dimethylaminomicheliolide (DMAMCL), is a new lead compound with the advantages of high stability, low toxicity, and sustainable release of MCL. This study aimed to investigate the protective effect of DMAMCL against PD-related PF and the mechanisms involved. In this study, we found that DMAMCL significantly decreased PD-induced extracellular matrix (ECM) deposition in a mouse model of PD, and that delayed DMAMCL administration halted the progression of PF in an established PD model. In addition, rapamycin administration induced autophagy and significantly ameliorated PF. The protective effect of DMAMCL against PF was weakened when co-administered with DMAMCL and 3-methyladenine. Inducing autophagy by rapamycin decreased transforming growth factor-β1-induced ECM accumulation in vitro. MCL promoted autophagy and inhibited ECM deposition. The anti-fibrotic effect of MCL was eliminated when knocking down ATG7 by siRNA. Taken together, DMAMCL might prevent against PF through activating autophagy. The anti-fibrotic effect of DMAMCL may be a new candidate for the treatment in patients with PD-related PF. KEY MESSAGES: Dimethylaminomicheliolide, the pro-drug of micheliolide, protects against peritoneal fibrosis in a mouse peritoneal dialysis model. Micheliolide inhibits TGF-β1-induced extracellular matrix accumulation in vitro. Autophagy plays a protective role against peritoneal fibrosis. The antifibrogenic effect of dimethylaminomicheliolide may be due to the activation of autophagy.

Bulleyaconitine A Effectively Relieves Allergic Lung Inflammation in a Murine Asthmatic Model

Background

Bulleyaconitine A (BLA) has been widely used as analgesic against chronic inflammatory pain in China. However, its potential therapeutic role in asthma remains unclear. The purpose of this study was to investigate the effect of BLA on airway inflammation in mice with allergic asthma.

Material/Methods

Specific-pathogen-free (SPF) female Balb/c mice were randomly divided into the following 6 groups: (1) Control group (NC), (2) Asthma group (AS), (3) BLA-L group, (4) BLA-M group, (5) BLA-H group, and (6) Dexamethasone group. An asthma mouse model was established by administration of ovalbumin (OVA) and mice were sacrificed within 24 h after the last challenge. Enzyme-linked immunosorbent assay (ELISA) method was used to determine the relative expression levels of IgE and IgG in mouse serum. In addition, bronchoalveolar lavage fluid (BALF) was collected and IL-4, TNF-α, and MCP-1 levels were determined by ELISA. Furthermore, eosinophils, lymphocytes, and macrophages in BALF were classified and analyzed, and inflammatory cell infiltration in the airways of mice was determined by hematoxylin-eosin (HE) staining. The expression of NF-κB1 and PKC-δ in mouse lung tissue was determined by Western blot analysis.

Results

The levels of serum IgE and IgG in BLA- or Dex- treated mice were significantly reduced compared to those in the asthma (AS) group (P<0.01), whereas the levels of cytokines IL-4, TNF-α, and MCP-1 were significantly decreased (P<0.01). HE-staining showed that BLA significantly reduced inflammatory cell infiltration and mucus secretion in lung tissue. Moreover, BLA inhibited the expression of NF-κB1 and PKC-δ via the NF-κB signaling pathway in the lung.

Conclusions

Our data show that BLA activates PKC-δ/NF-κB to reduce airway inflammation in allergic asthma mice.

A Novel Systems Pharmacology Method to Investigate Molecular Mechanisms of Scutellaria barbata D. Don for Non-small Cell Lung Cancer

Non-small cell lung cancer (NSCLC) is the most ordinary type of lung cancer which leads to 1/3 of all cancer deaths. At present, cytotoxic chemotherapy, surgical resection, radiation, and photodynamic therapy are the main strategies for NSCLC treatment. However, NSCLC is relatively resistant to the above therapeutic strategies, resulting in a rather low (20%) 5-year survival rate. Therefore, there is imperative to identify or develop efficient lead compounds for the treatment of NSCLC. Here, we report that the herb Scutellaria barbata D. Don (SBD) can effectively treat NSCLC by anti-inflammatory, promoting apoptosis, cell cycle arrest, and angiogenesis. In this work, we analyze the molecular mechanism of SBD for NSCLC treatment by applying the systems pharmacology strategy. This method combines pharmacokinetics analysis with pharmacodynamics evaluation to screen out the active compounds, predict the targets and assess the networks and pathways. Results show that 33 compounds were identified with potential anti-cancer effects. Utilizing these active compounds as probes, we predicted that 145 NSCLC related targets mainly involved four aspects: apoptosis, inflammation, cell cycle, and angiogenesis. And in vitro experiments were managed to evaluate the reliability of some vital active compounds and targets. Overall, a complete overview of the integrated systems pharmacology method provides a precise probe to elucidate the molecular mechanisms of SBD for NSCLC. Moreover, baicalein from SBD effectively inhibited tumor growth in an LLC tumor-bearing mice models, demonstrating the anti-tumor effects of SBD. Our findings further provided experimental evidence for the application in the treatment of NSCLC.