IκB kinase regulation of the TPL-2/ERK MAPK pathway

Intestinal Stromal Cells in the Turmoil of Inflammation and Defective Connective Tissue Remodeling in Inflammatory Bowel Disease

In steady state, intestinal subepithelial myofibroblasts form a thin layer below the basement membrane. Unlike the rest of the stromal cells in the lamina propria, they express tensile proteins, guide epithelial regeneration, and sense luminal microbiota. Upon inflammation in inflammatory bowel disease (IBD), they express activation markers, accept trophic signaling by infiltrating neutrophils and macrophages, and are activated by cytokines from helper T cells to produce a narrow spectrum of cytokines and a wider spectrum of chemokines, attract cells of innate and adaptive immunity, orchestrate inflammatory responses, and qualitatively and quantitatively modify the extracellular matrix. Thus, beyond being structural tissue components, they assume active roles in the pathogenesis of complicated IBD. Discrimination between myofibroblasts and fibroblasts may be an oversimplification in light of single-cell sequencing data unveiling the complexity of multiple phenotypes of stromal cells with distinct roles and plasticity. Spatial transcriptomics revealed distinct phenotypes by histologic localization and, more intriguingly, the assembly of mucosal neighborhoods that support spatially distinct functions. Current IBD treatments target inflammation but fail in fibrostenotic or fistulizing disease. Baseline and recent findings on stromal cells, molecules, and pathways involved in disrupted extracellular matrix homeostasis are reviewed to provide relevant pharmacologic targets.

Genetic susceptibility to temporomandibular joint involvement in juvenile idiopathic arthritis

BACKGROUND

Juvenile idiopathic arthritis (JIA) is the most common chronic rheumatic condition of childhood. Temporomandibular joint (TMJ) is among the most commonly affected joints in JIA patients. When JIA involves the TMJ, it may affect condylar growth in the joint; therefore, JIA patients are at risk of unfavourable long-term outcomes from associated joint damage. If undetected, TMJ involvement can lead to various functional disabilities such as reduced mandibular mobility and disorders of the mastication muscles. Limitations in sagittal and vertical mandibular growth can result in micrognathia and anterior open bite with aesthetic and functional restrictions.

OBJECTIVE

Genetic factors may play a role in determining which individuals are more prone to develop TMJ disorders or in predicting the severity of the disease process. Therefore, we applied a GWAS approach to identify loci associated with TMJ involvement in a sample of Estonian patients with JIA. Our aim was to address the potential role of genetic susceptibility factors in TMJ-JIA, a condition not previously studied in this context.

METHODS

The case group consisted of 55 JIA patients with TMJ involvement and 208 patients without TMJ involvement comprised the control group. The entire cohort was genotyped using the Illumina HumanOmniExpress BeadChip arrays. Imputation was performed using a nationwide reference panel obtained of 2240 individuals whose data were obtained from the Estonian Biobank.

RESULTS

We identified six loci as being associated with the risk of TMJ-JIA in Estonian JIA patients. The strongest associations were identified at CD6 rs3019551 (P = 3.80 × 10-6), SLC26A8/MAPK14 rs9470191 (P = 6.15 × 10-6), NLRP3 rs2056795 (P = 8.91 × 10-6) and MAP2K4 rs7225328 (P = 1.64 × 10-5).

CONCLUSION

This study provides first insights into the risk-associated loci between JIA and its manifestation in the TMJ. The reported loci are involved in molecular pathways of immunological relevance and likely represent genomic regions that render the TMJ susceptible to involvement by JIA in Estonian patients.

IL-1β-activated PI3K/AKT and MEK/ERK pathways coordinately promote induction of partial epithelial-mesenchymal transition

Epithelial-mesenchymal transition (EMT) is a cellular process in embryonic development, wound healing, organ fibrosis, and cancer metastasis. Previously, we and others have reported that proinflammatory cytokine interleukin-1β (IL-1β) induces EMT. However, the exact mechanisms, especially the signal transduction pathways, underlying IL-1β-mediated EMT are not yet completely understood. Here, we found that IL-1β stimulation leads to the partial EMT-like phenotype in human lung epithelial A549 cells, including the gain of mesenchymal marker (vimentin) and high migratory potential, without the complete loss of epithelial marker (E-cadherin). IL-1β-mediated partial EMT induction was repressed by PI3K inhibitor LY294002, indicating that the PI3K/AKT pathway plays a significant role in the induction. In addition, ERK1/2 inhibitor FR180204 markedly inhibited the IL-1β-mediated partial EMT induction, demonstrating that the MEK/ERK pathway was also involved in the induction. Furthermore, we found that the activation of the PI3K/AKT and MEK/ERK pathways occurred downstream of the epidermal growth factor receptor (EGFR) pathway and the IL-1 receptor (IL-1R) pathway, respectively. Our findings suggest that the PI3K/AKT and MEK/ERK pathways coordinately promote the IL-1β-mediated partial EMT induction. The inhibition of not one but both pathways is expected yield clinical benefits by preventing partial EMT-related disorders such as organ fibrosis and cancer metastasis.

MAP3K8 is a potential therapeutic target in airway epithelial inflammation

BACKGROUND

We have previously discovered clusters of sequentially negative and positive modulators of acute inflammation during cytokine stimulation in epithelial cells and identified potential targets for therapy within these clusters. MAP3K8 is a druggable kinase that we found to be a hub of a principal interaction network. We describe here the results of MAP3K8 knockdown in the A549 lung cancer cell line, the BEAS-2B epithelial cell line and normal human bronchial epithelial (NHBE) cells following IL-1β stimulation. We analysed signalling transduction and global gene expression after IL-1β stimulation with and without MAP3K8 knockdown, quantifying levels of the inflammatory cytokines IL-6, IL-8 and RANTES levels by qPCRs and/or by ELISAs. We also examined potential small molecule inhibitors for MAP3K8 in the same models.

RESULTS

IL-1β significantly and consistently increased MAP3K8 expression after 2 h in A549, BEAS-2B and NHBE cells. Phosphorylation of MAP3K8 occurred at 20 min after IL-1β stimulation and MAP3K8 protein was degraded at 30 min. MAP3K8 knockdown significantly reduced IL-6, IL-8 levels after IL-1β stimulation and yielded a 10-fold enhancement of the anti-inflammatory effects of dexamethasone. Phosphorylation of ERK1/2 (P-ERK1/2) and phosphorylation of SAPK/JNK (P-SAPK/JNK) decreased at 30 min after IL-1β stimulation with MAP3K8 knockdown. The combination of dexamethasone and MAP3K8 knockdown resulted in greater inhibition of phosphorylated ERK1/2 and SAPK/JNK. Nineteen genes including MMP1, MMP3, MMP10, ITGB8, LAMC2 and PLAT (P corrected < 0.01 respectively) demonstrated a distinct altered temporal response to IL-1β following suppression of MAP3K8. However, putative MAP3K8 inhibitors including Tpl2-1, Tpl2-2 and GSK2222867A only showed inhibition of IL-6 and IL-8 production at a high dose.

CONCLUSIONS

These results confirm that MAP3K8 is a key mediator of the early inflammatory response and that it is a potential target in inflammatory diseases. However, current tool compounds do not effectively inhibit its effects.

Targeting Protein Kinases to Protect Beta-Cell Function and Survival in Diabetes

The prevalence of diabetes is increasing worldwide. Massive death of pancreatic beta-cells causes type 1 diabetes. Progressive loss of beta-cell function and mass characterizes type 2 diabetes. To date, none of the available antidiabetic drugs promotes the maintenance of a functional mass of endogenous beta-cells, revealing an unmet medical need. Dysfunction and apoptotic death of beta-cells occur, in particular, through the activation of intracellular protein kinases. In recent years, protein kinases have become highly studied targets of the pharmaceutical industry for drug development. A number of drugs that inhibit protein kinases have been approved for the treatment of cancers. The question of whether safe drugs that inhibit protein kinase activity can be developed and used to protect the function and survival of beta-cells in diabetes is still unresolved. This review presents arguments suggesting that several protein kinases in beta-cells may represent targets of interest for the development of drugs to treat diabetes.

Design, synthesis and molecular modeling of novel D-ring substituted steroidal 4,5-dihydropyrazole thiazolinone derivatives as anti-inflammatory agents by inhibition of COX-2/iNOS production and down-regulation of NF-κB/MAPKs in LPS-induced RAW264.7 macrophage cells

It has been reported that 4,5-dihydropyrazole and thiazole derivatives have many biological functions, especially in the aspect of anti-inflammation. According to the strategy of pharmacophore combination, we introduced thiazolinone and dihydropyrazole moiety into steroid skeleton to design and synthesize a novel series of D-ring substituted steroidal 4,5-dihydropyrazole thiazolinone derivatives, and assessed their in vitro anti-inflammatory profiles against Lipopolysaccharide (LPS)-induced inflammation in RAW 264.7 macrophage cells. The anti-inflammatory activities assay demonstrated that compound 12e was considered as the most effective anti-inflammatory drug, which suppressed the expression of pro-inflammatory mediators including nitric oxide (NO), interleukin-6 (IL-6), and tumor necrosis factor-α (TNF-α), it also dose-dependently inhibited the expression of inducible nitric oxide synthase (iNOS) and cyclooxygenase-2 (COX-2) in LPS-induced RAW 264.7 macrophage cells. Furthermore, the results of the Western blot analysis showed a correlation between the inhibition of the Nuclear factor-kappa B (NF-κB) and Mitogen-activated protein kinases (MAPKs) signaling pathways and the suppressive effects of compound 12e on pro-inflammatory cytokines. Molecular docking studies of compound 12e into the COX-2 protein receptor (PDB ID: 5IKQ) active site was performed to rationalize their COX-2 inhibitory potency. The results were found to be in line with the biological findings as they exerted more favorable interactions compared to that of dexamethasone (DXM), explaining their remarkable COX-2 inhibitory activity. The findings revealed that these candidates could be identified as potent anti-inflammatory agents, compound 12e could be a promising drug for the treatment of inflammatory diseases.

Design, synthesis and molecular docking of novel D-ring substituted steroidal 4,5-dihydropyrazole thiazole derivatives that act as iNOS/COX-2 inhibitors with potent anti-inflammatory activity against LPS-induced RAW264.7 macrophage cells

Inflammation, an important biological protective response to tissue damage or microbial invasion, is considered to be an alarming signal for the progress of varied biological complications. Based on the previous reports in the literature that proved the noticeable efficacy of pyrazole and thiazole scaffold as well as nitrogen heterocyclic based compounds against acute and chronic inflammatory disease, a new set of novel D-ring substituted steroidal 4,5-dihydropyrazole thiazole derivatives were synthesized and evaluated their anti-inflammatory activities in vitro. Preliminary structure-activity relationship (SAR) analysis was conducted by their inhibitory activities against nitric oxide (NO) release in lipopolysaccharide (LPS)-induced RAW 264.7 cells, and the optimal compound 12b [3β-hydroxy-pregn-5-en-17β-yl-5'- (o- chlorophenyl)- 1'-(4''- phenyl -[1'', 3'']- thiazol-2''- yl) - 4',5'-dihydro - 1'H-pyrazol - 3'- yl] exhibited more potent anti-inflammatory activity than the positive control treatment methylprednisolone (MPS), with an IC50 value of 2.59 μM on NO production and low cytotoxicity against RAW 264.7 cells. In further mechanism study, our results showed that compound 12b significantly suppressed the production of tumor necrosis factor-α (TNF-α), interleukin-6 (IL-6), and inhibited the expressions of inducible nitric oxide synthase (iNOS), cyclooxygenase-2 (COX-2) through blocking NF-κB p65 nuclear translocation and phosphorylation of IκBα. Compound 12b also attenuated LPS-induced activation of c-Jun amino-terminal kinase (JNK) and p38 phosphorylation in RAW 264.7 cells. Molecular docking study revealed the strong binding affinity of compound 12b to the active site of the COX-2 proteins, which confirmed that compound 12b acted as an anti-inflammatory mediator. These results indicate that steroidal derivatives bearing 4,5-dihydropyrazole thiazole structure might be considered for further research and scaffold optimization in designing anti-inflammatory drugs and compound 12b might be a promising therapeutic anti-inflammatory drug candidate.

The Role of TLR4 in the Immunotherapy of Hepatocellular Carcinoma: Can We Teach an Old Dog New Tricks?

Hepatocellular carcinoma (HCC) is the most common type of primary liver cancer and is a leading cause of cancer-related death worldwide. Immunotherapy has emerged as the mainstay treatment option for unresectable HCC. Toll-like receptor 4 (TLR4) plays a crucial role in the innate immune response by recognizing and responding primarily to bacterial lipopolysaccharides. In addition to its role in the innate immune system, TLR4 has also been implicated in adaptive immunity, including specific anti-tumor immune responses. In particular, the TLR4 signaling pathway seems to be involved in the regulation of several cancer hallmarks, such as the continuous activation of cellular pathways that promote cell division and growth, the inhibition of programmed cell death, the promotion of several invasion and metastatic mechanisms, epithelial-to-mesenchymal transition, angiogenesis, drug resistance, and epigenetic modifications. Emerging evidence further suggests that TLR4 signaling holds promise as a potential immunotherapeutic target in HCC. The aim of this review was to explore the multilayer aspects of the TLR4 signaling pathway, regarding its role in liver diseases and HCC, as well as its potential utilization as an immunotherapy target for HCC.

Tumor progression locus 2 (TPL2): A Cot-plicated progression from inflammation to chronic liver disease

The cytoplasmic protein tumor progression locus 2 (TPL2), also known as cancer Osaka thyroid (Cot), or MAP3K8, is thought to have a significant role in a variety of cancers and illnesses and it is a key component in the activation pathway for the expression of inflammatory mediators. Despite the tight connection between inflammation and TPL2, its function has not been extensively studied in chronic liver disease (CLD), a major cause of morbidity and mortality worldwide. Here, we analyze more in detail the significance of TPL2 in CLD to shed light on the pathological and molecular transduction pattern of TPL2 during the progression of CLD. This might result in important advancements and enable progress in the diagnosis and treatment of CLD.

Mechanism of pulmonary plague biphasic syndrome: inhibition or activation of NF-κB signaling pathway

Background: Pneumonic plague is a fatal respiratory disease caused by Yersinia pestis. Time-course transcriptome analysis on the mechanism of pneumonic plague biphasic syndrome is lacking in the literature. Materials & methods: This study documented the disease course through bacterial load, histopathology, cytokine levels and flow cytometry. RNA-sequencing technology was used to investigate the global transcriptome profile of lung tissue in mice infected with Y. pestis. Results: Inflammation-related genes were significantly upregulated at 48 h post-infection, while genes related to cell adhesion and cytoskeletal structure were downregulated. Conclusion: NOD-like receptor and TNF signaling pathways play a plausible role in pneumonic plague biphasic syndrome and lung injury by controlling the activation and inhibition of the NF-κB signaling pathway.

B cell-intrinsic requirement for WNK1 kinase in antibody responses in mice

Migration and adhesion play critical roles in B cells, regulating recirculation between lymphoid organs, migration within lymphoid tissue, and interaction with CD4+ T cells. However, there is limited knowledge of how B cells integrate chemokine receptor and integrin signaling with B cell activation to generate efficient humoral responses. Here, we show that the WNK1 kinase, a regulator of migration and adhesion, is essential in B cells for T-dependent and -independent antibody responses. We demonstrate that WNK1 transduces signals from the BCR, CXCR5, and CD40, and using intravital imaging, we show that WNK1 regulates migration of naive and activated B cells, and their interactions with T cells. Unexpectedly, we show that WNK1 is required for BCR- and CD40-induced proliferation, acting through the OXSR1 and STK39 kinases, and for efficient B cell-T cell collaboration in vivo. Thus, WNK1 is critical for humoral immune responses, by regulating B cell migration, adhesion, and T cell-dependent activation.

Differential involvement of LUBAC-mediated linear ubiquitination in intestinal epithelial cells and macrophages during intestinal inflammation

Disruption of the intestinal epithelial barrier and dysregulation of macrophages are major factors contributing to the pathogenesis of inflammatory bowel diseases (IBDs). Activation of NF-κB and cell death are involved in maintaining intestinal homeostasis in a cell type-dependent manner. Although both are regulated by linear ubiquitin chain assembly complex (LUBAC)-mediated linear ubiquitination, the physiological relevance of linear ubiquitination to intestinal inflammation remains unexplored. Here, we used two experimental mouse models of IBD (intraperitoneal LPS and oral dextran sodium sulfate [DSS] administration) to examine the role of linear ubiquitination in intestinal epithelial cells (IECs) and macrophages during intestinal inflammation. We did this by deleting the linear ubiquitination activity of LUBAC specifically from IECs or macrophages. Upon LPS administration, loss of ligase activity in IECs induced mucosal inflammation and augmented IEC death. LPS-mediated death of LUBAC-defective IECs was triggered by TNF. IEC death was rescued by an anti-TNF antibody, and TNF (but not LPS) induced apoptosis of organoids derived from LUBAC-defective IECs. However, augmented TNF-mediated IEC death did not overtly affect the severity of colitis after DSS administration. By contrast, defective LUBAC ligase activity in macrophages ameliorated DSS-induced colitis by attenuating both infiltration of macrophages and expression of inflammatory cytokines. Decreased production of macrophage chemoattractant MCP-1/CCL2, as well as pro-inflammatory IL-6 and TNF, occurred through impaired activation of NF-κB and ERK via loss of ligase activity in macrophages. Taken together, these results indicate that both intraperitoneal LPS and oral DSS administrations are beneficial for evaluating epithelial integrity under inflammatory conditions, as well as macrophage functions in the event of an epithelial barrier breach. The data clarify the cell-specific roles of linear ubiquitination as a critical regulator of TNF-mediated epithelial integrity and macrophage pro-inflammatory responses during intestinal inflammation. © 2022 The Pathological Society of Great Britain and Ireland.

Whole-Transcriptome Analysis Highlights Adenylyl Cyclase Toxins-Derived Modulation of NF-κB and ERK1/2 Pathways in Macrophages

Edema toxin (ET), one of the main toxic factors of Bacillus anthracis (B. anthracis), is a kind of potent adenylate cyclase (AC). B. anthracis has adapted to resist macrophage microbicidal mechanisms in part by secreting ET. To date, there is limited information on the pathogenic mechanisms used by ET to manipulate macrophage function, especially at the transcriptome level. We used RNA sequencing to study transcriptional changes in RAW264.7 cells treated with ET. We aimed to identify molecular events associated with the establishment of infection and followed changes in cellular proteins. Our results indicate that ET inhibited TNF-α expression in the RAW264.7 mouse macrophage cell line by activating the cAMP/PKA pathway. ET challenge of macrophages induced a differential expression of genes that participate in multiple macrophage effector functions such as cytokine production, cell adhesion, and the inflammatory response. Furthermore, ET influenced the expression of components of the ERK1/2, as well as the NF-αB signaling pathways. We also showed that ET treatments inhibit the phosphorylation of the ERK1/2 protein. ET also attenuated NF-αB subunit p65 phosphorylation and transcriptional activity of NF-αB via the cAMP/PKA pathway in macrophages. Since the observed modulatory effects were characteristic only of the bacterial exotoxin ET, we propose this may be a mechanism used by B. anthracis to manipulate macrophages and establish systemic infection.

Establishment and characterization of a new activated B-cell-like DLBCL cell line, TMD12

We report the establishment of a novel activated B-cell-like (ABC) diffuse large B-cell lymphoma (DLBCL) cell line, designated as TMD12, from a patient with highly refractory DLBCL. ABC-DLBCL is a subtype with a relatively unfavorable prognosis that was originally categorized using gene expression profiling according to its cell of origin. TMD12 cells were isolated from the pleural effusion of the patient at relapse and passaged continuously in vitro for >4 years. The cells displayed cluster of differentiation (CD)19, CD20, CD22, CD38, human leukocyte antigen-DR isotype, and κ positivity and CD5, CD10, CD23, and λ negativity, as detected using flow cytometric analysis. The chromosomal karyotypic analysis, including the spectral karyotyping method, confirmed t(1;19)(q21:q13.1), del(6q23), gain of chromosome 18, and other abnormalities. Mutation analyses, including whole-exome sequencing, revealed that TMD12 cells harbored mutations in MYD88 and CD79B, indicating an ABC subtype. TMD12 cells exhibited chronic active B-cell receptor signaling and constitutive activation of the nuclear factor κB pathway, which is typically associated with sensitivity to a specific Bruton tyrosine kinase inhibitor, ibrutinib. Intriguingly, TMD12 cells displayed moderate resistance to ibrutinib and lacked activation of Janus kinase/signal transducers and activators of transcription 3 signaling, another hallmark of this DLBCL subtype. Treatment with an inhibitor against tumor progression locus 2 (TPL2), a multifunctional intracellular kinase that is activated particularly downstream of Toll-like receptors or MYD88 and IκB kinase α/β (IKKα/β), suppressed the proliferation of TMD12 cells, implying the possible involvement of the TPL2-p105 pathway in the tumorigenesis of ABC-DLBCL. Because only a limited number of ABC-DLBCL cell lines are currently available, TMD12 cells might provide a useful tool in the search for novel druggable targets for this intractable lymphoma.

Major pathways involved in macrophage polarization in cancer

Macrophages play an important role in tissue homeostasis, tissue remodeling, immune response, and progression of cancer. Consequently, macrophages exhibit significant plasticity and change their transcriptional profile and function in response to environmental, tissue, and inflammatory stimuli resulting in pro- and anti-tumor effects. Furthermore, the categorization of tissue macrophages in inflammatory situations remains difficult; however, there is an agreement that macrophages are predominantly polarized into two different subtypes with pro- and anti-inflammatory properties, the so-called M1-like and M2-like macrophages, respectively. These two macrophage classes can be considered as the extreme borders of a continuum of many intermediate subsets. On one end, M1 are pro-inflammatory macrophages that initiate an immunological response, damage tissue integrity, and dampen tumor progression by fostering robust T and natural killer (NK) cell anti-tumoral responses. On the other end, M2 are anti-inflammatory macrophages involved in tissue remodeling and tumor growth, that promote cancer cell proliferation, invasion, tumor metastasis, angiogenesis and that participate to immune suppression. These decisive roles in tumor progression occur through the secretion of cytokines, chemokines, growth factors, and matrix metalloproteases, as well as by the expression of immune checkpoint receptors in the case of M2 macrophages. Moreover, macrophage plasticity is supported by stimuli from the Tumor Microenvironment (TME) that are relayed to the nucleus through membrane receptors and signaling pathways that result in gene expression reprogramming in macrophages, thus giving rise to different macrophage polarization outcomes. In this review, we will focus on the main signaling pathways involved in macrophage polarization that are activated upon ligand-receptor recognition and in the presence of other immunomodulatory molecules in cancer.

TPL2 kinase expression is regulated by the p38γ/p38δ-dependent association of aconitase-1 with TPL2 mRNA

p38γ and p38δ (p38γ/p38δ) regulate inflammation, in part by controlling tumor progression locus 2 (TPL2) expression in myeloid cells. Here, we demonstrate that TPL2 protein levels are dramatically reduced in p38γ/p38δ-deficient (p38γ/δ^-/-) cells and tissues without affecting TPL2 messenger ribonucleic acid (mRNA) expression. We show that p38γ/p38δ posttranscriptionally regulates the TPL2 amount at two different levels. p38γ/p38δ interacts with the TPL2/A20 Binding Inhibitor of NF-κB2 (ABIN2)/Nuclear Factor κB1p105 (NF-κB1p105) complex, increasing TPL2 protein stability. Additionally, p38γ/p38δ regulates TPL2 mRNA translation by modulating the repressor function of TPL2 3' Untranslated region (UTR) mediated by its association with aconitase-1 (ACO1). ACO1 overexpression in wild-type cells increases the translational repression induced by TPL2 3'UTR and severely decreases TPL2 protein levels. p38δ binds to ACO1, and p38δ expression in p38γ/δ^-/- cells fully restores TPL2 protein to wild-type levels by reducing the translational repression of TPL2 mRNA. This study reveals a unique mechanism of posttranscriptional regulation of TPL2 expression, which given its central role in innate immune response, likely has great relevance in physiopathology.

NF-κB Inducing Kinase Regulates Intestinal Immunity and Homeostasis

Intestinal immunity and homeostasis are maintained through the regulation of cytokine trafficking, microbiota, necrosis and apoptosis. Intestinal immunity and homeostasis participate in host defenses and inflammatory responses locally or systemically through the gut-organ axis. NF-κB functions as a crucial transcription factor mediating the expression of proteins related to the immune responses. The activation of NF-κB involves two major pathways: canonical and non-canonical. The canonical pathway has been extensively studied and reviewed. Here, we present the current knowledge of NIK, a pivotal mediator of the non-canonical NF-κB pathway and its role in intestinal immunity and homeostasis. This review also discusses the novel role of NIK signaling in the pathogenesis and treatment of inflammatory bowel disease.

Cellular mechanism underlying the facilitation of contractile response induced by IL-25 in mouse tracheal smooth muscle

Asthma is a common heterogeneous respiratory disease characterized by airway inflammation and airway hyperresponsiveness (AHR) which is associated with abnormality in smooth muscle contractility. The epithelial cell-derived cytokine IL-25 is implicated in type 2 immune pathology including asthma, whereas the underlying mechanisms have not been fully elucidated. This study aims to investigate the effects of IL-25 on mouse tracheal smooth muscle contractility and elucidate the cellular mechanisms. Incubation with IL-25 augmented the contraction of mouse tracheal smooth muscles, which could be suppressed by the L-type voltage-dependent Ca²⁺ channel (L-VDCC) blocker nifedipine. Furthermore, IL-25 enhanced the cytosolic Ca²⁺ signals and triggered up-regulation of α1C L-VDCC (Ca_V1.2) in primary cultured mouse tracheal smooth muscle cells. Knocking down IL-17RA/IL-17RB receptors or inhibiting the transforming growth factor-β-activated kinase 1 (TAK1)-tumor progression locus 2 (TPL2)-MAPK kinase 1/2 (MEK1/2)-ERK1/2-activating protein-1 (AP-1) signaling pathways suppressed the IL-25-elicited up-regulation of Ca_V1.2 and hyperreactivity in tracheal smooth muscles. Moreover, inhibition of TPL2, ERK1/2 or L-VDCC alleviated the AHR symptom induced by IL-25 in a murine model. This study revealed that IL-25 potentiated the contraction of tracheal smooth muscle and evoked AHR via activation of TPL2-ERK1/2-Ca_V1.2 signaling, providing novel targets for the treatment of asthma with a high-IL-25 phenotype.

TPL-2 Inhibits IFN-β Expression via an ERK1/2-TCF-FOS Axis in TLR4-Stimulated Macrophages

TPL-2 activation of ERK1/2 regulates gene expression in TLR-stimulated macrophages.

TPL-2 regulates transcription via ERK1/2 phosphorylation of ternary complex factors.

TPL-2 inhibits Ifnb1 transcription via ternary complex factor–induced Fos mRNA expression.

TPL-2 kinase plays an important role in innate immunity, activating ERK1/2 MAPKs in myeloid cells following TLR stimulation. We investigated how TPL-2 controls transcription in TLR4-stimulated mouse macrophages. TPL-2 activation of ERK1/2 regulated expression of genes encoding transcription factors, cytokines, chemokines, and signaling regulators. Bioinformatics analysis of gene clusters most rapidly induced by TPL-2 suggested that their transcription was mediated by the ternary complex factor (TCF) and FOS transcription factor families. Consistently, TPL-2 induced ERK1/2 phosphorylation of the ELK1 TCF and the expression of TCF target genes. Furthermore, transcriptomic analysis of TCF-deficient macrophages demonstrated that TCFs mediate approximately half of the transcriptional output of TPL-2 signaling, partially via induced expression of secondary transcription factors. TPL-2 signaling and TCFs were required for maximal TLR4-induced FOS expression. Comparative analysis of the transcriptome of TLR4-stimulated Fos^−/− macrophages indicated that TPL-2 regulated a significant fraction of genes by controlling FOS expression levels. A key function of this ERK1/2-TCF-FOS pathway was to mediate TPL-2 suppression of type I IFN signaling, which is essential for host resistance against intracellular bacterial infection.

Synthesis and Evaluation of Bakuchiol Derivatives as Potent Anti-inflammatory Agents in Vitro and in Vivo

Bakuchiol, a prenylated phenolic monoterpene derived from the fruit of Psoralen corylifolia L. (Buguzhi), is widely used to treat tumors, viruses, inflammation, and bacterial infections. In this study, we designed and synthesized 30 bakuchiol derivatives to identify new anti-inflammatory drugs. The anti-inflammatory activities of the derivatives were screened using lipopolysaccharide-induced RAW264.7 cells. To evaluate the anti-inflammatory activity of the compounds, we measured nitric oxide (NO), interleukin-6, and tumor necrosis factor-α production. Based on the screening results, compound 7a displayed more pronounced activity than bakuchiol and celecoxib. Furthermore, the mechanistic studies indicated that 7a inhibited pro-inflammatory cytokine release, which was correlated with activation of the nuclear factor erythroid 2-related factor 2/heme oxygenase-1 signaling pathway and blockade of the nuclear factor-κB/mitogen-activated protein kinase signaling pathway. The in vivo anti-inflammatory activity in zebrafish indicated that 7a inhibited NO and reactive oxygen species production in a dose-dependent manner. These results indicate that 7a is a potential candidate for development as an anti-inflammatory agent.

MAP3K8 Is a Prognostic Biomarker and Correlated With Immune Response in Glioma

MAP3K8 is a serine/threonine kinase that is widely expressed in immune cells, non-immune cells, and many tumor types. The expression, clinical significance, biological role, and the underlying molecular mechanisms of MAP3K8 in glioma have not been investigated yet. Here, we discovered that MAP3K8 was aberrantly overexpressed in glioma and correlated with poor clinicopathological features of glioma by analysis on different datasets and immunohistochemistry staining. MAP3K8 is an independent prognostic indicator and significantly correlates with the progression of glioma. We also performed the function and pathway enrichment analysis of MAP3K8 in glioma to explore its biological functions and underlying molecular mechanisms in glioma. MAP3K8 co-expressed genes were mainly enriched in immune-related biological processes such as neutrophil activation, leukocyte migration, neutrophil-mediated immunity, lymphocyte-mediated immunity, T-cell activation, leukocyte cell–cell adhesion, regulation of leukocyte cell–cell adhesion, B-cell-mediated immunity, myeloid cell differentiation, and regulation of cell–cell adhesion. Single-cell RNA sequencing data and immunohistochemistry analysis demonstrated that MAP3K8 is expressed in malignant and immune cells and mainly enriched in the microglia/macrophage cells of glioma. The expression of MAP3K8 was positively correlated with immune infiltration, including effector memory CD4⁺ T cells, plasmacytoid dendritic cells, neutrophils, myeloid dendritic cells, mast cells, and macrophage in glioma. Further correlation analysis demonstrated that a series of inhibitory immune checkpoint molecules, chemokines, and chemokine receptors was positively correlated with the expression of MAP3K8. MAP3K8 might play an essential role in tumor immunity, and inhibition of MPA3K8 is a plausible strategy for glioma immunotherapy.

Differential regulation of lipopolysaccharide-induced IL-1β and TNF-α production in macrophages by palmitate via modulating TLR4 downstream signaling

Diabetic patients are susceptible to infectious diseases. Bacterial invasion activates immune cells such as macrophages through interaction between LPS and TLR4, and induces the expression of inflammatory mediators, including IL-1β and TNF-α, which play key roles in the elimination of infections. Unregulated overproduction or underproduction of these cytokines has been reported as a major factor in the development of septic shock, immune deficiency, and autoimmunity. Recent studies found that metabolic abnormalities of diabetes, such as hyperglycemia and dyslipidemia, played a major role in modulating the immune response. In this study, we studied the effects of palmitic acid (PA) pretreatment on LPS-induced IL-1β and TNF-α production and LPS-TLR4 signaling in macrophages. Compared with control, PA pretreatment significantly increased LPS-induced TNF-α production and secretion in macrophages. In contrast, LPS-induced IL-1β production and secretion was significantly suppressed by PA pretreatment. PA pretreatment did not affect the expression levels of TLR4 or Myd88, or the endocytosis of TLR4 in macrophages. However, PA pretreatment significantly suppressed the phosphorylation level and nuclear translocation of NF-κB, and the phosphorylation level of ERK1/2, whereas increased the phosphorylation levels of p38 and JNK. The activation of IKK which was upstream of NF-κB and ERK1/2 was attenuated, while the activation of TAK1 which was upstream of JNK and p38 was augmented by PA pretreatment. Inhibitors of NF-κB, MEK1/2, and p38 significantly decreased IL-1β expression, while JNK and p38 pathway inhibitors significantly inhibited TNF-α expression. The differential regulation of LPS-induced TNF-α and IL-1β production by PA was associated with cellular metabolism of PA, because inhibiting metabolism of PA with etomoxir or pretreatment with Br-PA which cannot be metabolized reversed these effects. We also showed that PA treatment increased acetylated IKK level which might contribute to the suppressed activation of IKK. The present study showed that LPS-induced production of TNF-α and IL-1β was regulated by different TLR4 downstream pathways in macrophages. PA differentially affected LPS-induced production of TNF-α and IL-1β in macrophages through differentially modulating these pathways. Further experiments will be needed to determine how these phenomena lead to the impaired immune response in patients with diabetes.

Design, Synthesis, and In Vitro and In Vivo Biological Evaluation of Limonin Derivatives for Anti-Inflammation Therapy

In this study, limonin derivatives were used to design new anti-inflammatory compounds with high pharmacological activity and low toxicity. A total of 23 new limonin derivatives were discovered, synthesized, and screened for their anti-inflammatory activity against lipopolysaccharide (LPS)-treated RAW 264.7 cells. Of them, compound f4 was found to be the most active, with a higher efficiency compared with limonin and celecoxib. Subsequently, we studied the mechanism underlying the activity of f4 and found that it inhibited proinflammatory cytokines by blocking the NF-κB/MAPK signaling pathway in LPS-treated RAW 264.7 cells as well as mice. In conclusion, f4 may be a promising anti-inflammatory lead compound.

Tpl2 contributes to IL-1β-induced IL-8 expression via ERK1/2 activation in canine dermal fibroblasts

In autoimmune diseases, fibroblasts produce and secrete various cytokines and act as sentinel immune cells during inflammatory states. However, the contribution of sentinel immune cells (i.e. dermal fibroblasts) in autoimmune diseases of the skin, such as atopic dermatitis, has been obscure. The pro-inflammatory cytokine interleukin 1β (IL-1β) induces the expression of chemokines, such as interleukin 8 (IL-8), in autoimmune diseases of the skin. IL-8 induces the activation and recruitment of innate immune cells such as neutrophils to the site of inflammation. IL-1β-mediated induction of IL-8 expression is important for the pathogenesis of autoimmune diseases; however, the intracellular singling remains to be understood. To elucidate the mechanism of the onset of autoimmune diseases, we established a model for IL-1β-induced dermatitis and investigated MAPK signaling pathways in IL-1β-induced IL-8 expression. We also identified that a MAP3K Tpl2 acts as an upstream modulator of IL-1β-induced ERK1/2 activation in dermal fibroblasts. We observed an increase in the expression of IL-8 mRNA and protein in cells treated with IL-1β. ERK1/2 inhibitors significantly reduced IL-1β-induced IL-8 expression, whereas the inhibitor for p38 MAPK or JNK had no effect. IL-1β induced ERK1/2 phosphorylation, which was attenuated in the presence of an ERK1/2 inhibitor. IL-1β failed to induce IL-8 expression in cells transfected with siRNA for ERK1, or ERK2. Notably, a Tpl2 inhibitor reduced IL-1β-induced IL-8 expression and ERK1/2 phosphorylation. We confirmed that the silencing of Tpl2 in siRNA-transfected fibroblasts prevented both in IL-1β-induced IL-8 expression and ERK1/2 phosphorylation. Taken together, our data indicate the importance of Tpl2 in the modulation of ERK1/2 signaling involved in the IL-1β-induced development of autoimmune diseases affecting the dermal tissue, such as atopic dermatitis.

Effect of MAP3K8 on Prognosis and Tumor-Related Inflammation in Renal Clear Cell Carcinoma

Background: MAPK kinase kinase 8 (MAP3K8) is involved in the regulation of MAPK cascades and immune responses. Differential expression of MAP3K8 is closely correlated with tumorigenesis. In this study, we used bioinformatics tools to explore expression level, prognostic values, and interactive networks of MAP3K8 in renal clear cell carcinoma (ccRCC).

Methods: Differential expression of MAP3K8 was determined by TIMER2.0, UALCAN, and Oncomine Platform. For exploration of MAP3K8 mutation profile, TIMER2.0, DriverDBv3, and cBioPortal were used. The survival module of GEPIA, UALCAN, and DriverDBv3 was used to examine the prognostic value of MAP3K8. Immune infiltration was estimated by TIMER, TIDE, CIBERSORT, CIBERSORT-ABS, QUANTISEQ, XCELL, MCPCOUNTER, and EPIC algorithms. PPI networks and functional enrichment analysis were constructed using GeneMANIA, Cytoscape, and Metascape. The co-expression module in cBioPortal was used to find genes that are correlated with MAP3K8 in mRNA expression.

Results: Compared to normal renal samples, ccRCC (3.08-fold change, P = 1.50E-7; 1.10-fold change, P = 3.00E-3), papillary RCC (2.24-fold change, P = 1.86E-4), and hereditary ccRCC (1.98-fold change, P = 1.69E-9) have significantly higher levels of MAP3K8 expression. Compared to Grade 1 ccRCC samples, Grade 2 (P = 1.28E-3) and Grade 3 (P = 7.41E-4) cases have higher levels of MAP3K8 methylation. Percentage of patients harboring MAP3K8 mutation is 0.3% from TIMER2.0 and 0.2 to 11.5% from cBioPortal. High levels of MAP3K8 expression were associated with poorer overall survival (OS) in ccRCC (GEPIA: Log-rank P = 0.60E-2, HR = 1.5; DriverDBv3: Log-rank P = 1.68E-7, HR = 2.21; UALCAN: P = 0.20E-2). MAP3K8 was positively correlated with the presence of T cell regulatory (Tregs) (QUANTISEQ: Rho = 0.33, P = 1.59E-13). PPI network and functional enrichment analyses revealed that MAP3K8 correlated with NFKBIZ, MIAT, PARP15, CHFR, MKNK1, and ERMN, which was mainly involved in I-kappaB kinase/NF-kappaB and toll-like receptor signaling pathways.

Conclusion: MAP3K8 overexpression was correlated with damaged survival in ccRC and may play a crucial role in cancer-related inflammation via I-kappaB kinase/NF-kappaB and toll-like receptor signaling pathways.

Stimulus-specific responses in innate immunity: Multilayered regulatory circuits

Immune sentinel cells initiate immune responses to pathogens and tissue injury and are capable of producing highly stimulus-specific responses. Insight into the mechanisms underlying such specificity has come from the identification of regulatory factors and biochemical pathways, as well as the definition of signaling circuits that enable combinatorial and temporal coding of information. Here, we review the multi-layered molecular mechanisms that underlie stimulus-specific gene expression in macrophages. We categorize components of inflammatory and anti-pathogenic signaling pathways into five layers of regulatory control and discuss unifying mechanisms determining signaling characteristics at each layer. In this context, we review mechanisms that enable combinatorial and temporal encoding of information, identify recurring regulatory motifs and principles, and present strategies for integrating experimental and computational approaches toward the understanding of signaling specificity in innate immunity.

Artemisinin Protects Porcine Mammary Epithelial Cells against Lipopolysaccharide-Induced Inflammatory Injury by Regulating the NF-κB and MAPK Signaling Pathways

Simple Summary

Sow mastitis is a serious breast disease that can cause severe inflammation, agalaxia and even lead to death of piglets. Porcine mammary epithelial cells (pMECs) are the main cell types that affect sow milk secretion, therefore, when swine mastitis occurs, the inflammatory response of pMECs directly affects the mammary gland health and sow’s lactation ability. Promoting the health of mammary gland epithelial cells is an important method for treating mastitis. Thus, in the current study, we investigated the effects of artemisinin on the inflammatory response of pMECs induced by lipopolysaccharide (LPS), and proposed a potential anti-inflammatory mechanism. We confirmed that artemisinin can reduce the inflammatory damage of pMECs induced by LPS by inhibiting MAPK and NF-κB signaling pathways. Pretreatment of pMECs with artemisinin showed enhanced anti-inflammatory activity against LPS-induced inflammation. Artemisinin could be a useful, safe and natural anti-inflammatory feed additive to prevent sow mastitis.

Abstract

Artemisinin performs a variety of biological functions, such as anti-cancer, anti-inflammatory, anti-viral, and anti-oxidant effects. However, the effects of artemisinin on sow mastitis have not been studied. The results of the current study showed that mRNA expression abundance and content of the inflammatory factors interleukin-1β (IL-1β), tumor necrosis factor α (TNF-α), and interleukin-6 (IL-6) were significantly increased when using 50 μg/mL LPS to stimulate pMECs for 24 h (p < 0.05). Pretreatment with 20 μM artemisinin weakened LPS-induced inflammatory damage in pMECs and decreased mRNA expression abundance and the content of inflammatory factors (IL-1β, IL-6, and TNF-α) in pMECs (p < 0.05). Mechanistically, artemisinin inhibited LPS-induced activation of the mitogen-activated protein kinase (MAPK) and nuclear factor-κB (NF-κB) signaling pathways. In summary, the pretreatment of pMECs with artemisinin showed enhanced anti-inflammatory activity against LPS-induced inflammation.

Endothelial Tpl2 regulates vascular barrier function via JNK-mediated degradation of claudin-5 promoting neuroinflammation or tumor metastasis

Increased vascular permeability and leakage are hallmarks of several pathologies and determine disease progression and severity by facilitating inflammatory/metastatic cell infiltration. Using tissue-specific genetic ablation in endothelial cells, we have investigated in vivo the role of Tumor progression locus 2 (Tpl2), a mitogen-activated protein kinase kinase kinase (MAP3K) member with pleiotropic effects in inflammation and cancer. In response to proinflammatory stimuli, endothelial Tpl2 deletion alters tight junction claudin-5 protein expression through inhibition of JNK signaling and lysosomal degradation activation, resulting in reduced vascular permeability and immune cell infiltration. This results in significantly attenuated disease scores in experimental autoimmune encephalomyelitis and fewer tumor nodules in a hematogenic lung cancer metastasis model. Accordingly, pharmacologic inhibition of Tpl2 or small interfering RNA (siRNA)-mediated Tpl2 knockdown recapitulates our findings and reduces lung metastatic tumor invasions. These results establish an endothelial-specific role for Tpl2 and highlight the therapeutic potential of blocking the endothelial-specific Tpl2 pathway in chronic inflammatory and metastatic diseases.

TPL-2 kinase induces phagosome acidification to promote macrophage killing of bacteria

Tumour progression locus 2 (TPL‐2) kinase mediates Toll‐like receptor (TLR) activation of ERK1/2 and p38α MAP kinases in myeloid cells to modulate expression of key cytokines in innate immunity. This study identified a novel MAP kinase‐independent regulatory function for TPL‐2 in phagosome maturation, an essential process for killing of phagocytosed microbes. TPL‐2 catalytic activity was demonstrated to induce phagosome acidification and proteolysis in primary mouse and human macrophages following uptake of latex beads. Quantitative proteomics revealed that blocking TPL‐2 catalytic activity significantly altered the protein composition of phagosomes, particularly reducing the abundance of V‐ATPase proton pump subunits. Furthermore, TPL‐2 stimulated the phosphorylation of DMXL1, a regulator of V‐ATPases, to induce V‐ATPase assembly and phagosome acidification. Consistent with these results, TPL‐2 catalytic activity was required for phagosome acidification and the efficient killing of Staphylococcus aureus and Citrobacter rodentium following phagocytic uptake by macrophages. TPL‐2 therefore controls innate immune responses of macrophages to bacteria via V‐ATPase induction of phagosome maturation.

Foot-and-Mouth Disease Virus Structural Protein VP1 Destroys the Stability of TPL2 Trimer by Degradation TPL2 to Evade Host Antiviral Immunity

Tumor progression locus 2 (TPL2) is a serine/threonine kinase that belongs to the mitogen-activated protein 3 kinase (MAP3K) family, and it plays an important role in pathogen infection. The trimer complex of TPL2, p105, and ABIN2 is essential for maintenance of TPL2 steady-state levels and host cell response to pathogens. Foot-and-mouth disease virus (FMDV) is a positive-strand RNA virus of the family Picornaviridae that encodes proteins capable of antagonizing host immune responses to achieve infection. The VP1 protein of FMDV is a multifunctional protein that can bind host cells and induce an immune response as well as cell apoptosis. However, the role and mechanisms of TPL2 in FMDV infection remain unknown. Here, we determined that FMDV infection could inhibit TPL2, p105, and ABIN2 at the transcription and protein levels, while VP1 could only inhibit TPL2, p105 and ABIN2 at protein level. TPL2 inhibited the replication of FMDV in vivo and in vitro, the 268 to 283 amino-acid region in the TPL2 kinase domain was essential for interaction with VP1. Moreover, VP1 promoted K48-linked polyubiquitination of TPL2 and degraded TPL2 by the proteasome pathway. However, VP1-induced degradation of p105 and ABIN2 was independent of proteasome, autophagy, lysosome, and caspase-dependent pathways. Further studies showed that VP1 destroyed the stability of the TPL2-p105-ABIN2 complex. Taken together, these results revealed that VP1 antagonized TPL2-meditated antivirus activity by degrading TPL2 and destroying its complex. These findings may contribute to understand FMDV-host interactions and improve development of a novel vaccine to prevent FMDV infection.Importance Virus-host interactions are critical for virus infection. This study was the first to demonstrate the antiviral effect of host TPL2 during FMDV replication by increasing production of interferons and antiviral cytokines. Both FMDV and VP1 protein can reduce host TPL2, ABIN2 and p105 to destroy TPL2-p105-ABIN2 trimer complex. VP1 interacted with TPL2 and degrade TPL2 via proteasome pathway to repress TPL2-mediated antivirus activity. This study provided new insights into FMDV immune evasion mechanisms, elucidating new informations regarding FMDV counteraction of host antivirus activity.

The Anti-inflammatory Effects of the Bioactive Compounds Isolated from Alpinia officinarum Hance Mediated by the Suppression of NF-kappaB and MAPK Signaling

This study was designed to evaluate the anti-inflammatory effects of Alpinia officinarum Hance extract (AOE) and identify its main active ingredients. AOE was obtained using a 95% ethanol extraction method. Lipopolysaccharide (LPS) were used to induce an inflammatory response in RAW264.7 cells. The results showed that AOE exerts anti-inflammatory effects via inhibition of prostaglandin E₂ secretion and cyclooxygenase -2 (COX-2) production. We further analyzed the components of AOE using high-performance liquid chromatography and found that AOE is comprised of several bioactive flavonoids including quercetin (Q), kaempferol (K), galangin (G), and curcumin (C). These four flavonoids effectively inhibited nitric oxide (NO), interleukin (IL)-1β, IL-6, and tumor necrosis factor-α production. Moreover, they reduced COX-2 and inducible NO synthase expressions via regulation of nuclear factor kappa-light-chain-enhancer of activated B cells and c-Jun N-terminal kinase signaling pathways. Furthermore, we compared and contrasted the anti-inflammatory effects and mechanisms of these four flavonoids at the same dose in the LPS-induced cell inflammation model. The results showed that C is the most effective inhibitor of LPS-induced NO production. However, only Q and K effectively attenuated LPS-induced extracellular signal-regulated kinase and p38 elevations. In conclusion, AOE and its major bioactive compounds exert anti-inflammatory effects on LPS-induced inflammation. As A. officinarum Hance is much cheaper than any of its four flavonoids, especially G, we suggest using AOE as an anti-inflammatory agent.

Adenosine A2A Receptor Agonist Polydeoxyribonucleotide Alleviates Interstitial Cystitis-Induced Voiding Dysfunction by Suppressing Inflammation and Apoptosis in Rats

Background

Interstitial cystitis (IC) is a chronic disorder that indicates bladder-related pain or discomfort. Patients with IC often experience urination problems, such as urinary frequency and urgency, along with pain or discomfort in the bladder area. Therefore, new treatments based on IC etiology are needed. Polydeoxyribonucleotide (PDRN) is a biologic agonist of the adenosine A_2A receptor, and PDRN has anti-inflammatory effect and inhibits apoptosis. In the current study, the effect of PDRN on cyclophosphamide-induced IC animal model was investigated using rats.

Methodology

To induce the IC animal model, 75 mg/kg of cyclophosphamide was injected intraperitoneally once every 3 days for 10 days. The rats in the PDRN-treated groups were intraperitoneally injected with 0.5 mL physiological saline containing 8 mg/kg PDRN, once a day for 10 days after IC induction.

Results

Induction of IC by cyclophosphamide injection caused voiding dysfunction, bladder edema, and histological damage. Cyclophosphamide injection increased secretion of pro-inflammatory cytokines and enhanced apoptosis. In contrast, PDRN treatment alleviated voiding dysfunction, bladder edema, and histological damage. Secretion of pro-inflammatory cytokines and expressions of apoptotic factors were suppressed by PDRN treatment. These changes indicate that treatment with PDRN improves voiding function by ultimately promoting the repair of damaged bladder tissue.

Conclusion

The conclusion of this experiment suggests the possibility that PDRN could be used as an effective therapeutic agent for IC.

Heritable Gut Microbiome Associated with Salmonella enterica Serovar Pullorum Infection in Chickens

Pullorum disease is one of the most common diarrhea-related diseases caused by Salmonella enterica subspecies enterica serovar Gallinarum biovar Pullorum (S Pullorum); it negatively affects the poultry industry. However, limited studies have explored the association between the gut microbiota and S Pullorum infection in chickens. In the present study, we performed a microbiome comparison and a microbiome genome-wide association study (mGWAS) to investigate the association among the host genetics, the gut microbiota, and pullorum disease in chickens. We found that S Pullorum infection in chickens could alter the abundance of 39 bacterial genera (P < 0.05). The altered structure and composition of the gut microbiota were also detected in the offspring. mGWAS results revealed host genetic variants to be prominently associated with gut microbial diversity and individual microbes. The pathogens Pelomonas and Brevundimonas, which had a high abundance in positive parent chickens and their offspring, were significantly associated with several genetic mutations in immunity-related genes, such as TGIF1, TTLL12, and CCR7 This finding explained why Pelomonas and Brevundimonas were heritable in S Pullorum-infected chickens. The heritable gut microbes and identified genetic variants could provide references for the selection of resistant chickens and the elimination of pullorum disease.IMPORTANCE The present study investigated the association among the host genome, the gut microbiome, and S Pullorum infection in chickens. The results suggested that the gut microbial structure is altered in S Pullorum-infected chickens. The diversity and abundance of the gut microbiota remarkably differed between the offspring coming from S Pullorum-positive and S Pullorum-negative chickens. Heritable gut microbiota were detected in the offspring. Moreover, host genetic variants were associated with microbial diversity and individual gut microbes. The pathogens Pelomonas and Brevundimonas, which exhibited a high heritability in S Pullorum-positive parents and their offspring, were associated with several genetic mutations in immunity-related genes.

Structurally modified glycyrrhetinic acid derivatives as anti-inflammatory agents

With the aim of finding new anti-inflammatory drugs, a series of new Glycyrrhetinic acid derivatives (1-34) have been designed and synthesized by structural modification, and their anti-inflammatory activities in vitro have been evaluated. The anti-inflammatory activities assay demonstrated that compound 5b suppressed the expression of pro-inflammatory cytokines including IL-6, TNF-α and NO, it also suppressed the expression of iNOS and COX-2 in LPS-induced RAW264.7 cells in a dose-dependent manner. Additionally, western blot results indicated that the suppressing effect of compound 5b on pro-inflammatory cytokines were correlated with the suppression of NF-κB and MAPK signaling pathways. The results attained in this study indicated that compound 5b had the potential to be developed into an anti-inflammation agent and it may be applied to the prevention and treatment of inflammatory diseases.

Activation of c-Jun N-Terminal Kinase, a Potential Therapeutic Target in Autoimmune Arthritis

The c-Jun-N-terminal kinase (JNK) is a critical mediator involved in various physiological processes, such as immune responses, and the pathogenesis of various diseases, including autoimmune disorders. JNK is one of the crucial downstream signaling molecules of various immune triggers, mainly proinflammatory cytokines, in autoimmune arthritic conditions, mainly including rheumatoid arthritis, ankylosing spondylitis, and psoriatic arthritis. The activation of JNK is regulated in a complex manner by upstream kinases and phosphatases. Noticeably, different subtypes of JNKs behave differentially in immune responses. Furthermore, aside from biologics targeting proinflammatory cytokines, small-molecule inhibitors targeting signaling molecules such as Janus kinases can act as very powerful therapeutics in autoimmune arthritis patients unresponsiveness to conventional synthetic antirheumatic drugs. Nevertheless, despite these encouraging therapies, a population of patients with an inadequate therapeutic response to all currently available medications still remains. These findings identify the critical signaling molecule JNK as an attractive target for investigation of the immunopathogenesis of autoimmune disorders and for consideration as a potential therapeutic target for patients with autoimmune arthritis to achieve better disease control. This review provides a useful overview of the roles of JNK, how JNK is regulated in immunopathogenic responses, and the potential of therapeutically targeting JNK in patients with autoimmune arthritis.

Her2 promotes early dissemination of breast cancer by suppressing the p38 pathway through Skp2-mediated proteasomal degradation of Tpl2

While mechanisms for metastasis were extensively studied in cancer cells from patients with detectable tumors, pathways underlying metastatic dissemination from early lesions before primary tumors appear are poorly understood. Her2 promotes breast cancer early dissemination by suppressing p38, but how Her2 downregulates p38 is unclear. Here, we demonstrate that in early lesion breast cancer models, Her2 inhibits p38 by inducing Skp2 through Akt-mediated phosphorylation, which promotes ubiquitination and proteasomal degradation of Tpl2, a p38 MAP3K. The early disseminating cells are Her2⁺Skp2^highTpl2^lowp-p38^lowE-cadherin^low in the MMTV-Her2 breast cancer model. In human breast carcinoma, high Skp2 and low Tpl2 expression are associated with the Her2⁺ status; Tpl2 expression positively correlates with that of activated p38; Skp2 expression negatively correlates with that of Tpl2 and activated p38. Moreover, the Her2-Akt-Skp2-Tpl2-p38 axis plays a key role in the disseminating phenotypes in early lesion breast cancer cells; inhibition of Tpl2 enhances early dissemination in vivo. These findings identify the Her2-Akt-Skp2-Tpl2-p38 cascade as a novel mechanism mediating breast cancer early dissemination and a potential target for novel therapies targeting early metastatic dissemination.

Baicalin suppresses Propionibacterium acnes-induced skin inflammation by downregulating the NF-κB/MAPK signaling pathway and inhibiting activation of NLRP3 inflammasome

Acne is a kind of common, chronic skin condition caused by the inflammation of the sebaceous glands in hair follicles. Recent studies have demonstrated that baicalin (BA) possesses potential anti-inflammatory properties. In this study, we evaluated the anti-inflammatory activity of BA in vitro and in vivo. Heat-killed Propionibacterium acnes-induced THP-1 cells and live P. acnes-injected male Sprague Dawley rats were used for establishing the acne model. The rate of ear swelling was calculated, and the severity was determined by hematoxylin and eosin staining. The production of cytokines [interleukin (IL)-1β, IL-6, IL-8, and tumor necrosis factor (TNF-α)] in the cell supernatant and ear tissue homogenates was measured by ELISA. Protein levels of JNK, ERK, P38, IκBα, P65, Nod-like receptor pyrin domain-containing 3 (NLRP3), pro-caspase-1, and IL-1β in THP-1 cells and ear tissues were detected by western blotting. NLRP3 and IL-1β were detected by immunohistochemistry, and the NLRP3, IL-1β and pro-caspase-1 mRNAs were detected by quantitative real-time polymerase chain reaction (qRT-PCR). The results showed that BA decreased the expression of pro-inflammatory cytokines in vitro and in vivo. Moreover, BA down-regulated the phosphorylation of JNK, ERK1/2, and κBα and inhibited the nuclear translocation of p65. Furthermore, BA inhibited the activation of NLRP3 inflammasome, at both the gene and protein levels. Taken together, the results demonstrated that BA might exert its anti-inflammatory activity by inhibiting NF-κB/MAPK signaling pathways and consequently suppressing the activation of the NLRP3 inflammasome both in vivo and in vitro.

Tumor progression locus 2 (TPL2) in tumor-promoting Inflammation, Tumorigenesis and Tumor Immunity

Over the years, tumor progression locus 2 (TPL2) has been identified as an essential modulator of immune responses that conveys inflammatory signals to downstream effectors, subsequently modulating the generation and function of inflammatory cells. TPL2 is also differentially expressed and activated in several cancers, where it is associated with increased inflammation, malignant transformation, angiogenesis, metastasis, poor prognosis and therapy resistance. However, the relationship between TPL2-driven inflammation, tumorigenesis and tumor immunity has not been addressed. Here, we reconcile the function of TPL2-driven inflammation to oncogenic functions such as inflammation, proliferation, apoptosis resistance, angiogenesis, metastasis, immunosuppression and immune evasion. We also address the controversies reported on TPL2 function in tumor-promoting inflammation and tumorigenesis, and highlight the potential role of the TPL2 adaptor function in regulating the mechanisms leading to pro-tumorigenic inflammation and tumor progression. We discuss the therapeutic implications and limitations of targeting TPL2 for cancer treatment. The ideas presented here provide some new insight into cancer pathophysiology that might contribute to the development of more integrative and specific anti-inflammatory and anti-cancer therapeutics.

Neuronal ERK MAPK signaling in response to low-dose nanopolystyrene exposure by suppressing insulin peptide expression in Caenorhabditis elegans

The responses of different organs are important for organisms against the toxicity of environmental toxicants. So far, the neuronal response to nanoplastic exposure and the underlying mechanisms are still largely unclear. Due to the sensitivity to environmental exposures, we here employed Caenorhabditis elegans as an animal model to examine the role of ERK MAPK signaling pathway in the neurons to regulate the response to nanopolystyrene (100 nm). Nanopolystyrene exposure in the range of μg/L could significantly increase expressions of genes (lin-45, mek-2, and mpk-1) encoding ERK MAPK signaling pathway. Nanopolystyrene at the predicted environmental concentration of 1 μg/L could only significantly increase the mpk-1 expression. Meanwhile, RNAi knockdown of any of these genes caused a susceptibility to nanopolystyrene toxicity. ERK/MPK-1 acted in the neurons to regulate the response to nanopolystyrene. Moreover, three genes (ins-4, ins-39, and daf-28) encoding insulin peptides were identified as the downstream targeted genes of neuronal mpk-1 in regulating the response to nanopolystyrene. In nanopolystyrene exposed nematodes, neuronal RNAi knockdown of ins-4, ins-39, or daf-28 decreased expression of intestinal daf-2 encoding insulin receptor and increased expression of intestinal daf-16 encoding FOXO transcriptional factor. Therefore, the neuronal ERK MAPK signaling responded to nanopolystyrene by modulating the insulin signaling-mediated communication between neurons and intestine in nematodes. Our findings are helpful for understanding the molecular basis of neuronal response to nanopolystyrene in organisms.

Electro-Acupuncture Inhibits p66Shc-Mediated Oxidative Stress to Facilitate Functional Recovery After Spinal Cord Injury

Oxidative stress is the core problem in improving secondary spinal cord injury (SCI). To investigate the effect of electro-acupuncture with different frequencies on neuroinflammation, oxidative stress injury, as well as related signaling pathways, male Sprague-Dawley (SD) rats were induced using operation for model SCI and then treated with electrical stimulation at low frequency (2 mA, 0.2 Hz), medium frequency (2 mA, 50 Hz), and high frequency (2 mA, 100 Hz), respectively. Here, we first demonstrated that the JNK/p66^Shc signal pathway promoted ROS generation and inhibited the anti-oxidation effect of FoxO3a to induce oxidative stress damage after SCI and the mechanism of electro-acupuncture in anti-oxidative stress. Electro-acupuncture facilitated functional recovery after SCI and improved the apoptosis of neurons. Furthermore, p38MAPK-mediated microglia activation and inflammatory reaction and JNK/p66^Shc-mediated ROS generation and oxidative stress damage were both attenuated by electro-acupuncture. However, the inhibitory effect of electro-acupuncture on p38MAPK was enslaved to the acupuncture frequency, but the ROS generation and phosphorylation of p66^Shc were effectively inhibited by electro-acupuncture. Therefore, the activation of JNK/p66^Shc promoted the ROS-induced oxidative stress damage after SCI, and inhibiting the phosphorylation of p66^Shc-mediated oxidative stress was the key target of electro-acupuncture to facilitate functional recovery SCI, but not p38MAPK.

A central role of IKK2 and TPL2 in JNK activation and viral B-cell transformation

IκB kinase 2 (IKK2) is well known for its pivotal role as a mediator of the canonical NF-κB pathway, which has important functions in inflammation and immunity, but also in cancer. Here we identify a novel and critical function of IKK2 and its co-factor NEMO in the activation of oncogenic c-Jun N-terminal kinase (JNK) signaling, induced by the latent membrane protein 1 (LMP1) of Epstein-Barr virus (EBV). Independent of its kinase activity, the TGFβ-activated kinase 1 (TAK1) mediates LMP1 signaling complex formation, NEMO ubiquitination and subsequent IKK2 activation. The tumor progression locus 2 (TPL2) kinase is induced by LMP1 via IKK2 and transmits JNK activation signals downstream of IKK2. The IKK2-TPL2-JNK axis is specific for LMP1 and differs from TNFα, Interleukin-1 and CD40 signaling. This pathway mediates essential LMP1 survival signals in EBV-transformed human B cells and post-transplant lymphoma, and thus qualifies as a target for treatment of EBV-induced cancer.

Canscora lucidissima, a Chinese folk medicine, exerts anti-inflammatory activities by inhibiting the phosphorylation of ERK1/2 in LPS-activated macrophages

Background

Canscora lucidissima (Levl. & Vaniot) Hand.-Mazz. (C. lucidissima), mainly distributed in southern China, has been shown to be effective in the treatment of inflammatory diseases. However, the underlying mechanism of its anti-inflammatory effect is not fully understood.

Methods

In this study, we investigated the anti-inflammatory mechanism of ethanol extract of C. lucidissima (Cl-EE) in lipopolysaccharide (LPS)-induced inflammatory models. ELISA, real-time PCR, Western blot and luciferase reporter assay were used for the experiments in vitro, and ICR mouse endotoxemia model was used for in vivo test.

Results

Our data showed that Cl-EE reduced the production of NO by down-regulating the mRNA and protein expression of inducible nitric oxide synthase (iNOS) in LPS-activated RAW 264.7 cells. Meanwhile, it potently decreased other proinflammatory mediators, such as TNF-α, IL-6, MCP-1 and IL-1β at the transcriptional and translational levels. Further study indicated that Cl-EE did not affect NF-κB signaling pathway but significantly suppressed the phosphorylation of ERK1/2, rather than JNK or p38. In a LPS-induced endotoxemia mouse model, a single intraperitoneal injection of Cl-EE (75–300 mg/kg) could lower circulatory TNF-α, IL-6 and MCP-1 levels.

Conclusions

Collectively, our results indicated that Cl-EE suppressed the phosphorylation level of ERK1/2 thus reducing the transcription and translation of inflammatory genes, thereby exerted anti-inflammatory activity. This study reveals the anti-inflammatory mechanism of C. lucidissima and may provide an effective treatment option for a variety of inflammatory diseases.

Heracleum moellendorffii roots inhibit the production of pro-inflammatory mediators through the inhibition of NF-κB and MAPK signaling, and activation of ROS/Nrf2/HO-1 signaling in LPS-stimulated RAW264.7 cells

BACKGROUND

Heracleum moellendorffii roots (HM-R) have been long treated for inflammatory diseases such as arthritis, backache and fever. However, an anti-inflammatory effect and the specific mechanism of HM-R were not yet clear. In this study, we for the first time explored the anti-inflammatory of HM-R.

METHODS

The cytotoxicity of HM-R against RAW264.7 cells was evaluated using MTT assay. The inhibition of NO and PGE₂ production by HM-R was evaluated using Griess reagent and Prostaglandin E₂ ELISA Kit, respectively. The changes in mRNA or protein level following HM-R treatment were assessed by RT-PCR and Western blot analysis, respectively.

RESULTS

HM-R dose-dependently blocked LPS-induced NO and PGE₂ production. In addition, HM-R inhibited LPS-induced overexpression of iNOS, COX-2, IL-1β and IL-6 in RAW264.7 cells. HM-R inhibited LPS-induced NF-κB signaling activation through blocking IκB-α degradation and p65 nuclear accumulation. Furthermore, HM-R inhibited MAPK signaling activation by attenuating the phosphorylation of ERK1/2, p38 and JNK. HM-R increased nuclear accumulation of Nrf2 and HO-1 expression. However, NAC reduced the increased nuclear accumulation of Nrf2 and HO-1 expression by HM-R. In HPLC analysis, falcarinol was detected from HM-R as an anti-inflammatory compound.

CONCLUSIONS

These results indicate that HM-R may exert anti-inflammatory activity by inhibiting NF-κB and MAPK signaling, and activating ROS/Nrf2/HO-1 signaling. These findings suggest that HM-R has a potential as a natural material for the development of anti-inflammatory drugs.

ABIN-2, of the TPL-2 Signaling Complex, Modulates Mammalian Inflammation

Mammalian TPL-2 kinase (MAP3K8) mediates Toll-like receptor activation of ERK1/2 and p38α MAP kinases and is critical for regulating immune responses to pathogens. TPL-2 also has an important adaptor function, maintaining stability of associated ABIN-2 ubiquitin-binding protein. Consequently, phenotypes detected in Map3k8^-/- mice can be caused by lack of TPL-2, ABIN-2, or both proteins. Recent studies show that increased inflammation of Map3k8^-/- mice in allergic airway inflammation and colitis results from reduced ABIN-2 signaling, rather than blocked TPL-2 signaling. However, Map3k8^-/- mice have been employed extensively to evaluate the potential of TPL-2 as an anti-inflammatory drug target. We posit that Map3k8^D270A/D270A mice, expressing catalytically inactive TPL-2 and physiologic ABIN-2, should be used to evaluate the potential effects of TPL-2 inhibitors in disease.

Extracellular Signal-Regulated Kinase: A Regulator of Cell Growth, Inflammation, Chondrocyte and Bone Cell Receptor-Mediated Gene Expression

Extracellular signal-regulated kinase (ERK) is a member of the mitogen-activated protein kinase family of signaling molecules. ERK is predominantly found in two forms, ERK1 (p44) and ERK2 (p42), respectively. There are also several atypical forms of ERK, including ERK3, ERK4, ERK5 and ERK7. The ERK1/2 signaling pathway has been implicated in many and diverse cellular events, including proliferation, growth, differentiation, cell migration, cell survival, metabolism and transcription. ERK1/2 is activated (i.e., phosphorylated) in the cytosol and subsequently translocated to the nucleus, where it activates transcription factors including, but not limited to, ETS, c-Jun, and Fos. It is not surprising that the ERK1/2 signaling cascade has been implicated in many pathological conditions, namely, cancer, arthritis, chronic inflammation, and osteoporosis. This narrative review examines many of the cellular events in which the ERK1/2 signaling cascade plays a critical role. It is anticipated that agents designed to inhibit ERK1/2 activation or p-ERK1/2 activity will be developed for the treatment of those diseases characterized by dysregulated gene expression through ERK1/2 activation.