Regulation of tissue homeostasis by NF-kappaB signalling: implications for inflammatory diseases

Single-nucleus transcriptome profiling provides insights into the pathophysiology of adhesive arachnoiditis

Adhesive arachnoiditis (AA) is a rare form of chronic degenerative pathology associated with persistent inflammation in the arachnoid matter of the spinal cord. Despite the existing knowledge, the detailed pathological mechanisms underlying AA are not fully understood. This study aimed to elucidate through comprehensive single nuclei RNA sequencing (snRNA-seq) to delineate the transcriptomic landscape of AA. From six arachnoid membrane samples, a total of 52,886 cells met the quality control standards for analysis. The main cell populations identified with specific gene markers were as follows: fibroblasts, glial cells, microglial cells, endothelial cells, mural cells, plasma cells, and T cells. Downstream analysis of fibroblasts, glial cells, and microglial cells was performed. Notably, fibroblast subsets 1 and 3 demonstrated a strong association with AA. Among them, subcluster 3 demonstrated elevated expression of genes COL1A1, COL3A1, and FN1, indicative of enhanced Wnt/β-catenin and extracellular matrix (ECM) synthesis pathways. Subcluster 3 was predicted to progressively transform into subcluster 1. In subcluster 1, there was a significant upregulation of genes such as BMP and ALPL, signaling enhanced activation of calcification-related pathways. This was highly relevant to end-stage arachnoid ossification formation. After being activated, microglial cells transformed into inflammatory disease-associated microglial cells and continued to express high levels of chemokines CCL2, CCL4, IL-1β, and other inflammatory factors NAMPT, INPP5D and NLRP3. This might be the main reason why AA recurrence is frequently observed in patients. These insights enhance our understanding of the pathological progression of AA and may contribute to the identification of novel therapeutic targets.

Artesunate alleviates radiation-induced submandibular gland epithelial cell damage in rats by reducing inflammation and apoptosis

Salivary hypofunction is a common complication in patients with head and neck cancers following radiotherapy (RT). RT-induced inflammation in salivary gland cells leads to apoptosis and fibrosis. Artesunate (ART) is a bioactive compound with anti-inflammatory and anti-fibrosis properties. This study aimed to investigate the protective effects of ART on X-ray-induced injury of submandibular gland (SMG) epithelial cells in rats. Second-generation SMG epithelial cells were randomly divided into five groups: natural control group (NC), irradiated group (IR), and irradiated groups treated with ART at concentrations of 5, 10, and 20 μM. Cells were harvested 48 h postirradiation for analysis. The results demonstrated that ART attenuated the damage to AQP5, a crucial indicator of salivary gland function, as evidenced by the decreased expression of AQP5 at both mRNA and protein levels. Additionally, ART decreased the expression of inflammatory cytokines: IL-6 and TNF-α. TUNEL staining revealed reduced apoptosis in the ART groups, particularly the IR + 10 μM group. RT-PCR and Western blot analysis of apoptosis cytokines Bax/Bcl-2 and Caspase-3 confirmed these findings. Furthermore, ART inhibited the expression of NF-κB at both mRNA and protein levels. In conclusion, these results suggest that ART may reduce inflammation and apoptosis in SMG epithelial cells following radiation by inhibiting the NF-κB pathway.

Icariin-loaded chitosan/β-glycerophosphate thermosensitive hydrogel enhanced infection control and bone regeneration in canine with infectious bone defects

Faced with infectious bone defects, the development of a thermosensitive hydrogel containing icariin (ICA) represents a promising therapeutic strategy targeting infection control and bone regeneration. In this study, we prepared and evaluated the physicochemical properties, in vitro and in vivo drug release, antimicrobial activity, anti-inflammatory properties, and bone repair effects of ICA/Chitosan/β-Glycerophosphate (ICA/CTS/β-GP) thermosensitive hydrogel. Our findings demonstrate that the ICA/CTS/β-GP thermosensitive hydrogel undergoes a liquid-to-gel transition at body temperature, which is crucial for maintaining local drug release at the defect site. Additionally, the hydrogel exhibited sustained release of ICA over 28 days, showing high antimicrobial activity against Staphylococcus aureus and good biocompatibility in blood compatibility tests. In a canine model of infectious bone defects, the ICA/CTS/β-GP thermosensitive hydrogel showed effective infection control and modulated inflammation, vascular formation, and bone factor expression, while also activating the Wnt/β-catenin signaling pathway. In conclusion, the ICA/CTS/β-GP thermosensitive hydrogel could control infection and repair bone tissue. Its antimicrobial and osteogenic properties provide hope for its clinical application.

IĸBζ as a Central Modulator of Inflammatory Arthritis Pathogenesis

OBJECTIVE

Current therapies targeting individual factors in inflammatory arthritis show variable efficacy, often requiring treatment with combinations of drugs, and are associated with undesirable side effects. NF-ĸB is critical for the production and function of most inflammatory cytokines. However, given its essential role in physiologic processes, targeting NF-ĸB is precarious. Hence, identifying pathways downstream of NF-ĸB that selectively govern the expression of inflammatory cytokines in inflammatory arthritis would be advantageous. We have previously identified IĸBζ as a unique inflammatory signature of NF-ĸB that controls the transcription of inflammatory cytokines only under pathologic conditions while sparing physiologic NF-ĸB signals.

METHODS

We generated mice harboring myeloid, lymphoid, and global deletion of Nfkbiz (the gene encoding IĸBζ). These models were subjected to serum transfer-induced arthritis. Additionally, pharmacologic inhibitors of IĸBζ were injected intraperitonially. Joint swelling, microcomputed tomography, immunohistochemistry, flow cytometry, and cytokine measurements were conducted using synovial tissue samples.

RESULTS

Global deletion of Nfkbiz or depletion of neutrophils (vastly IĸBζ+ cells) reduced inflammatory synovial cells and increased anti-inflammatory and regenerative synovial cells, plummeted expression of inflammatory factors and ameliorated experimental mouse inflammatory arthritis. Further, expression of immune responsive gene-1, the enzyme responsible for itaconate production, was increased in synovial cells. Accordingly, the itaconate derivative dimethyl itaconate (DI) inhibited IĸBζ-mediated inflammatory factors. Further, in silico screen identified 8-hydroxyquinoline (HQ) as a putative inhibitor of IĸBζ not affecting physiologic NF-ĸB activity. Congruently, systemic administration of either DI or HQ inhibited joint swelling and damage.

CONCLUSION

Our study positions IĸBζ as an inflammation-specific target for therapeutic consideration in rheumatoid arthritis because its inhibition spares the beneficial functions of NF-ĸB.

Curcumin attenuates ulcerative colitis via regulation of Sphingosine kinases 1/NF-κB signaling pathway

Curcumin, a compound from Curcuma longa L., has significant anti-inflammatory properties. However, the mechanisms underlying its anti-inflammatory activity in dextran sodium sulfate (DSS)-induced ulcerative colitis (UC) remain inadequately understood. This study aimed to further elucidate the molecular mechanisms of curcumin DSS-induced UC mice. Our data showed that curcumin alleviated DSS-induced colitis by reducing intestinal damage and inflammation, increasing goblet cells in colon tissues. Enzyme-linked immunosorbent assay revealed that curcumin reduced the expression of inflammatory cytokines (tumor necrosis factor-alpha, interleukin-1β, and interleukin-8) in serum and myeloperoxidase in colon tissues. A comprehensive analysis integrating network pharmacology and RNA sequencing (RNA-seq) revealed significant enrichment of the nuclear factor kappa B (NF-κB) signaling pathways. Notably, RNA-seq analysis demonstrated that curcumin significantly downregulated the mRNA expression of sphingosine kinase 1 (SphK1). Furthermore, molecular docking analysis showed that curcumin can bind to SphK1 and NF-κB. Additionally, curcumin was found to inhibit the activation of the SphK1/NF-κB signaling pathway in DSS-induced UC colon tissue. This study addresses pharmacologic and mechanistic perspectives of curcumin that ameliorates DSS-induced UC and inflammatory response.

Arctigenin ameliorates high-fat diet-induced metabolic disorders by reshaping gut microbiota and modulating GPR/HDAC3 and TLR4/NF-κB pathways

BACKGROUND

Arctigenin (AG), a phenylpropanoid lignan from the medicinal and food homologous plant Arctium lappa l., is known for its anti-cancer, anti-inflammatory and antioxidant properties. However, the pharmacological effects of AG on metabolic disorders remain limited, and specific mechanisms based on gut microbiota have not been reported.

PURPOSE

This study aimed to evaluate the regulation of glycolipid metabolism by AG in obese mice and investigate the potential mechanisms associated with gut microbes.

METHODS

The anti-obesity efficacy of AG was evaluated in high-fat diet (HFD)-fed mice. 16S rRNA gene sequencing and GC-MS were used to detect changes in gut microbes and metabolite levels. Immunohistochemistry, immunofluorescence, and polymerase chain reaction were used to validate the molecular mechanisms of gut microbe-derived metabolites involved in the improvement of intestinal homeostasis and hepatic metabolism by AG.

RESULTS

We found that AG significantly ameliorated HFD-induced glucolipid metabolism disorders, liver degeneration and the imbalance of macrophage M1/M2 polarization. In addition, AG attenuated intestinal barrier damage, inflammation and imbalance of Th17/Treg immune in HFD mice. Importantly, AG promoted short-chain fatty acid (SCFA)-producing bacteria and SCFA levels, which regulated the G protein-coupled receptor (GPR)41/43 and HDAC3 pathways to induce FOXP3 protein expression and consequently maintained intestinal Th17/Treg immunity. AG also inhibited lipopolysaccharide (LPS) production leading to attenuation of TLR4/NF-κB-mediated intestinal inflammation. Furthermore, AG upregulated intestinal MCT1 protein levels to promote absorption of SCFA and activated the hepatic GPR41/43/109a-AMPK pathway to regulate lipid metabolism, and thus reduced lipid accumulation.

CONCLUSION

This study first demonstrated that AG could modulate the gut microbiota and derived metabolites to repair intestinal damage and regulate hepatic metabolic pathways, thereby ameliorating metabolic disorders induced by HFD. These findings support the great potential of AG as a novel prebiotic to fight obesity and chronic metabolic diseases by targeting the gut microbiota.

Challenges in tendon-bone healing: emphasizing inflammatory modulation mechanisms and treatment

Tendons are fibrous connective tissues that transmit force from muscles to bones. Despite their ability to withstand various loads, tendons are susceptible to significant damage. The healing process of tendons and ligaments connected to bone surfaces after injury presents a clinical challenge due to the intricate structure, composition, cellular populations, and mechanics of the interface. Inflammation plays a pivotal role in tendon healing, creating an inflammatory microenvironment through cytokines and immune cells that aid in debris clearance, tendon cell proliferation, and collagen fiber formation. However, uncontrolled inflammation can lead to tissue damage, and adhesions, and impede proper tendon healing, culminating in scar tissue formation. Therefore, precise regulation of inflammation is crucial. This review offers insights into the impact of inflammation on tendon-bone healing and its underlying mechanisms. Understanding the inflammatory microenvironment, cellular interactions, and extracellular matrix dynamics is essential for promoting optimal healing of tendon-bone injuries. The roles of fibroblasts, inflammatory cytokines, chemokines, and growth factors in promoting healing, inhibiting scar formation, and facilitating tissue regeneration are discussed, highlighting the necessity of balancing the suppression of detrimental inflammatory responses with the promotion of beneficial aspects to enhance tendon healing outcomes. Additionally, the review explores the significant implications and translational potential of targeted inflammatory modulation therapies in refining strategies for tendon-bone healing treatments.

A scallop IκB protein involved in innate immunity acts as a key regulator of NF-κB

Chlamys farreri, a commercially important bivalve mollusk, is extensively cultivated in China. In recent years, the frequent occurrence of diseases has led to significant mortality in scallop farms. Despite this, our understanding of scallop's innate immune mechanisms remains limited. The NF-κB signaling pathway plays a crucial role in various biological processes, including cellular, developmental, and immune defense mechanisms. Inhibitors of NF-κB (IκB) proteins block the nuclear localization and DNA binding of NF-κB, thereby inhibiting its activity. However, the role of these proteins in invertebrates is not well understood. In this study, we identified a new homolog of the IκB gene in C. farreri, named CfIκB1. The open reading frame of CfIκB1 spans 1089 bp, encoding 362 amino acids. Through sequence comparison and phylogenetic analysis, CfIκB1 was classified as a member of the invertebrate IκB family. Quantitative real-time PCR revealed that CfIκB1 transcripts are present in all examined tissues, with the highest expression observed in hemocytes. Expression levels were significantly upregulated following exposure to lipopolysaccharide, peptidoglycan, and polyinosinic:polycytidylic acid. Co-immunoprecipitation studies confirmed that CfIκB1 interacts with NF-κB family proteins CfRel-1 and CfRel. Dual-luciferase reporter assays demonstrated that CfIκB1 inhibits CfRel-dependent activation of NF-κB, ISRE, IFNβ, and AP-1. These findings suggest that CfIκB1 plays a crucial role in regulating NF-κB activity, which is integral to the innate immunity of C. farreri. This research enhances our understanding of the innate immune system in invertebrates and provides a theoretical basis for developing disease-resistant scallops at the molecular level.

Phytochemical Compounds as Promising Therapeutics for Intestinal Fibrosis in Inflammatory Bowel Disease: A Critical Review

BACKGROUND/OBJECTIVE

Intestinal fibrosis, a prominent consequence of inflammatory bowel disease (IBD), presents considerable difficulty owing to the absence of licensed antifibrotic therapies. This review assesses the therapeutic potential of phytochemicals as alternate methods for controlling intestinal fibrosis. Phytochemicals, bioactive molecules originating from plants, exhibit potential antifibrotic, anti-inflammatory, and antioxidant activities, targeting pathways associated with inflammation and fibrosis. Compounds such as Asperuloside, Berberine, and olive phenols have demonstrated potential in preclinical models by regulating critical signaling pathways, including TGF-β/Smad and NFκB, which are integral to advancing fibrosis.

RESULTS

The main findings suggest that these phytochemicals significantly reduce fibrotic markers, collagen deposition, and inflammation in various experimental models of IBD. These phytochemicals may function as supplementary medicines to standard treatments, perhaps enhancing patient outcomes while mitigating the adverse effects of prolonged immunosuppressive usage. Nonetheless, additional clinical trials are necessary to validate their safety, effectiveness, and bioavailability in human subjects.

CONCLUSIONS

Therefore, investigating phytochemicals may lead to crucial advances in the formulation of innovative treatment approaches for fibrosis associated with IBD, offering a promising avenue for future therapeutic development.

Attenuating mitochondrial dysfunction-derived reactive oxygen species and reducing inflammation: the potential of Daphnetin in the viral pneumonia crisis

Amidst the global burden of viral pneumonia, mitigating the excessive inflammatory response induced by viral pneumonia has emerged as a significant challenge. Pneumovirus infections can lead to the persistent activation of M1 macrophages, culminating in cytokine storms that exacerbate pulmonary inflammation and contribute to the development of pulmonary fibrosis. Mitochondria, beyond their role as cellular powerhouses, are pivotal in integrating inflammatory signals and regulating macrophage polarization. Mitochondrial damage in alveolar macrophages is postulated to trigger excessive release of reactive oxygen species (ROS), thereby amplifying macrophage-mediated inflammatory pathways. Recent investigations have highlighted the anti-inflammatory potential of Daphnetin, particularly in the context of cardiovascular and renal disorders. This review elucidates the mechanisms by which viral infection-induced mitochondrial damage promotes ROS generation, leading to the phenotypic shift of alveolar macrophages towards a pro-inflammatory state. Furthermore, we propose a mechanism whereby Daphnetin attenuates inflammatory signaling by inhibiting excessive release of mitochondrial ROS, thus offering mitochondrial protection. Daphnetin may represent a promising pharmacological intervention for viral pneumonia and could play a crucial role in addressing future pandemics.

Identification of COMMD gene family in large yellow croaker (Larimichthys crocea): Immune response induced by Pseudomonas plecoglossicida infection and acute hypoxia stress

The COMMD (Copper Metabolism gene MURR1 Domain) gene family consists of 10 members, which are involved in various biological processes such as copper and sodium transport, NF-κB activity and cell cycle progression. However, the study of COMMD gene family in large yellow croaker (Larimichthys crocea) is largely unknown. In this study, 10 COMMD gene family members (named LcCOMMDs) were successfully identified from large yellow croaker. The results showed that there were differences in the number of LcCOMMDs exons at the level of gene structure, which reflected that they had adjusted and changed accordingly in the process of evolution to adapt to the environment and achieved functional diversification. Through phylogenetic analysis, we found that the LcCOMMDs was highly conserved, indicating their important functions in organisms. It was worth noting that the expression levels of LcCOMMD1, LcCOMMD2, LcCOMMD3, LcCOMMD5 and LcCOMMD10 in the spleen changed significantly after bacterial stress, which suggested that these genes might be involved in the regulation of innate immune response. In addition, the expression levels of LcCOMMD1, LcCOMMD2, LcCOMMD3, LcCOMMD5, LcCOMMD7, LcCOMMD8, LcCOMMD9 and LcCOMMD10 changed significantly after hypoxia exposure, which further proved the role of LcCOMMDs in immune function. In summary, this study not only revealed the important role of COMMD genes in the innate immune response of large yellow croaker, but also provided valuable information for further understanding the regulatory mechanism of COMMD gene family under different conditions.

METTL3 restricts RIPK1-dependent cell death via the ATF3-cFLIP axis in the intestinal epithelium

Intestinal epithelial cells (IECs) are pivotal for maintaining intestinal homeostasis through self-renewal, proliferation, differentiation, and regulated cell death. While apoptosis and necroptosis are recognized as distinct pathways, their intricate interplay remains elusive. In this study, we report that Mettl3-mediated m6A modification maintains intestinal homeostasis by impeding epithelial cell death. Mettl3 knockout induces both apoptosis and necroptosis in IECs. Targeting different modes of cell death with specific inhibitors unveils that RIPK1 kinase activity is critical for the cell death triggered by Mettl3 knockout. Mechanistically, this occurs via the m6A-mediated transcriptional regulation of Atf3, a transcription factor that directly binds to Cflar, the gene encoding the anti-cell death protein cFLIP. cFLIP inhibits RIPK1 activity, thereby suppressing downstream apoptotic and necroptotic signaling. Together, these findings delineate the essential role of the METTL3-ATF3-cFLIP axis in homeostatic regulation of the intestinal epithelium by blocking RIPK1 activity.

Design and Synthesis of Novel Aminoindazole-pyrrolo[2,3-b]pyridine Inhibitors of IKKα That Selectively Perturb Cellular Non-Canonical NF-κB Signalling

The inhibitory-kappaB kinases (IKKs) IKKα and IKKβ play central roles in regulating the non-canonical and canonical NF-κB signalling pathways. Whilst the proteins that transduce the signals of each pathway have been extensively characterised, the clear dissection of the functional roles of IKKα-mediated non-canonical NF-κB signalling versus IKKβ-driven canonical signalling remains to be fully elucidated. Progress has relied upon complementary molecular and pharmacological tools; however, the lack of highly potent and selective IKKα inhibitors has limited advances. Herein, we report the development of an aminoindazole-pyrrolo[2,3-b]pyridine scaffold into a novel series of IKKα inhibitors. We demonstrate high potency and selectivity against IKKα over IKKβ in vitro and explain the structure-activity relationships using structure-based molecular modelling. We show selective target engagement with IKKα in the non-canonical NF-κB pathway for both U2OS osteosarcoma and PC-3M prostate cancer cells by employing isoform-related pharmacodynamic markers from both pathways. Two compounds (SU1261 [IKKα Ki = 10 nM; IKKβ Ki = 680 nM] and SU1349 [IKKα Ki = 16 nM; IKKβ Ki = 3352 nM]) represent the first selective and potent pharmacological tools that can be used to interrogate the different signalling functions of IKKα and IKKβ in cells. Our understanding of the regulatory role of IKKα in various inflammatory-based conditions will be advanced using these pharmacological agents.

Immunomodulatory and immune-toxicological role of nanoparticles: Potential therapeutic applications

Nowadays, Nanoparticle-based immunotherapeutic research has invoked global interest due to their unique properties. The immune system is a shielding structure that defends living things from external threats. Before the use of any materials in drug design, it is essential to study the immunological response to avoid triggering undesirable immune responses in the body. This review tries to summarize the properties, various applications, and immunotherapeutic aspects of NP-induced immunomodulation relating to therapeutic development and toxicity in human health. The role of NPs in the immune system and their modulatory functions, resulting in immunosuppression or immunostimulation, exerts benefits or dangers depending on their compositions, sizes, surface chemistry, and so forth. After NPs enter into the body, they can interact with body fluid exposing, them to different body proteins to form protein corona particles and other bio-molecules (DNA, RNA, sugars, etc.), which may alter their bioactivity. Phagocytes are the first immune cells that can interact with foreign materials including nanoparticles. Immunostimulation and immunosuppression operate in two distinct manners. Overall, functionalized nanocarriers optimized various therapeutic implications by stimulating the host immune system and regulating the tranquility of the host immune system. Among others, toxicity and bio-clearance of nanomaterials are always prime concerns at the preclinical and clinical stages before final approval. The interaction of nanoparticles with immune cells causes direct cell damage via apoptosis and necroses as well as immune signaling pathways also become influenced.

Alleviative effects of exopolysaccharides from Limosilactobacillus mucosae CCFM1273 against ulcerative colitis via modulation of gut microbiota and inhibition of Fas/Fasl and TLR4/NF-κB pathways

Ulcerative colitis (UC) has become a public health challenge as its global prevalence increases annually. The use of prebiotics in healthcare has grown in recent years. Thus, the present study was designed to explore the alleviating effects and mechanisms of exopolysaccharides (EPS) produced by Limosilactobacillus mucosae CCFM1273 on UC. The results indicated that CCFM1273 EPS mitigated the disease symptoms and colonic pathologic damage in DSS-induced colitis mice. Moreover, CCFM1273 EPS improved the intestinal barrier by restoring goblet cell numbers and MUC2 production, enhancing intercellular junctions, and inhibiting epithelial cell apoptosis. In addition, CCFM1273 EPS inhibited colonic inflammation and oxidative stress. Importantly, CCFM1273 EPS augmented short-chain fatty acid (SCFA) producers, leading to increased levels of SCFAs (especially propionic acid), which inhibited the Fas/Fasl pathway and consequently inhibited epithelial apoptosis, and diminished Gram-negative bacteria, further decreasing lipopolysaccharides (LPS), which suppressed the TLR4/NF-κB pathway and consequently suppressed colonic inflammation, eventually relieving UC in mice. This study provides theoretical support for the use of prebiotics in clinical practice for UC.

Wheat peptides inhibit the activation of MAPK and NF-κB inflammatory pathways and maintain epithelial barrier integrity in NSAID-induced intestinal epithelial injury

The use of non-steroidal anti-inflammatory drugs (NSAIDs) has negative effects on the gastrointestinal tract, but the proton pump inhibitors currently in use only protect against gastrointestinal disease and may even make NSAID-induced enteropathy worse. Therefore, new approaches to treating enteropathy are required. This study aimed to investigate the protective effect of wheat peptides (WPs) against NSAID-induced intestinal damage in mice and their mechanism. Here, an in vivo mouse model was built to investigate the protective and reparative effects of different concentrations of WPs on NSAID-induced intestinal injury. WPs ameliorated NSAID-induced weight loss and small intestinal tissue damage in mice. WP treatment inhibited NSAID-induced injury leading to increased levels of oxidative stress and expression levels of inflammatory factors. WPs protected and repaired the integrity and permeability injury of the intestinal tight junction induced by NSAIDs. An in vitro Caco-2 cell model was built with lipopolysaccharide (LPS). WP pretreatment inhibited LPS-induced changes in the Caco-2 cell permeability and elevated the levels of oxidative stress. WPs inhibited LPS-induced phosphorylation of NF-κB p65 and mitogen-activated protein kinase (MAPK) signaling pathways and reduced the expression of inflammatory factors. In addition, WPs increased tight junction protein expression, which contributed to improved intestinal epithelial dysfunction. Our results suggest that WPs can ameliorate NSAID-induced impairment of intestinal barrier functional integrity by improving intestinal oxidative stress levels and reducing inflammatory factor expression through inhibition of NF-κB p65 and MAPK signaling pathway activation. WPs can therefore be used as potential dietary supplements to reduce NSAID-induced injury of the intestine.

Catalpol ameliorates LPS-induced inflammatory response by activating AMPK/mTOR signaling pathway in rat intestinal epithelial cells

Intestinal inflammation is a common clinical intestinal disease. Catalpol, a natural iridoid compound, has been shown to have anti-inflammatory, anti-oxidant and anti-apoptotic functions, but the mechanism of its protection against intestinal inflammation is still unclear. This study investigated the protective effect and potential mechanism of catalpol on the lipopolysaccharide (LPS)-induced inflammatory response of intestinal epithelial cell-6 (IEC-6). The results showed that catalpol could inhibit LPS-induced inflammatory response by dose-dependently reducing the release of inflammatory factors, such as tumor necrosis (TNF)-α, interleukin (IL)-1β and IL-6, and inhibiting the nuclear factor kappa-B (NF-κB) signaling pathway. Catalpol ameliorated cellular oxidative stress by reducing reactive oxygen species (ROS) and malondialdehyde (MDA) levels and increasing superoxide dismutase (SOD) and glutathione peroxidase (GSH-PX) expression. Meanwhile, catalpol also inhibited cell apoptosis, decreased the expression of B-cell lymphoma 2 (Bcl-2) - associated X (Bax), caspase 3 and caspase 9, and increased the expression of Bcl-2. This study found that catalpol activates AMP-activated protein kinase (AMPK) signaling pathway and inhibit mammalian target of rapamycin (mTOR) phosphorylationthe. In a further study, after inhibiting AMPK with dorsomorphin, the anti-inflammatory effects of catalpol were significantly reduced. Therefore, catalpol ameliorates LPS-induced inflammatory response by activating AMPK/mTOR signaling pathway in IEC-6 cells.

The Antioxidant and Immunomodulatory Potential of Coccoloba alnifolia Leaf Extracts

Oxidative stress has been associated with different diseases, and different medicinal plants have been used to treat or prevent this condition. The leaf ethanolic extract (EE) and aqueous extract (AE) from Coccoloba alnifolia have previously been characterized to have antioxidant potential in vitro and in vivo. In this study, we worked with EE and AE and two partition phases, AF (ethyl acetate) and BF (butanol), from AE extract. These extracts and partition phases did not display cytotoxicity. The EE and AE reduced NO production and ROS in all three concentrations tested. Furthermore, it was observed that EE and AE at 500 μg/mL concentration were able to reduce phagocytic activity by 30 and 50%, respectively. A scratch assay using a fibroblast cell line (NHI/3T3) showed that extracts and fractions induced cell migration with 60% wound recovery within 24 h, especially for BF. It was also observed that AF and BF had antioxidant potential in all the assays evaluated. In addition, copper chelation was observed. This activity was previously not detected in AE. The HPLC-DAD analysis showed the presence of phenolic compounds such as p-cumaric acid and vitexin for extracts, while the GNPS annotated the presence of isoorientin, vitexin, kanakugiol, and tryptamine in the BF partition phase. The data presented here demonstrated that the EE, AE, AF, and BF of C. alnifolia have potential immunomodulatory effects, antioxidant effects, as well as in vitro wound healing characteristics, which are important for dynamic inflammation process control.

The mechanism of ferroptosis and its related diseases

Ferroptosis, a regulated form of cellular death characterized by the iron-mediated accumulation of lipid peroxides, provides a novel avenue for delving into the intersection of cellular metabolism, oxidative stress, and disease pathology. We have witnessed a mounting fascination with ferroptosis, attributed to its pivotal roles across diverse physiological and pathological conditions including developmental processes, metabolic dynamics, oncogenic pathways, neurodegenerative cascades, and traumatic tissue injuries. By unraveling the intricate underpinnings of the molecular machinery, pivotal contributors, intricate signaling conduits, and regulatory networks governing ferroptosis, researchers aim to bridge the gap between the intricacies of this unique mode of cellular death and its multifaceted implications for health and disease. In light of the rapidly advancing landscape of ferroptosis research, we present a comprehensive review aiming at the extensive implications of ferroptosis in the origins and progress of human diseases. This review concludes with a careful analysis of potential treatment approaches carefully designed to either inhibit or promote ferroptosis. Additionally, we have succinctly summarized the potential therapeutic targets and compounds that hold promise in targeting ferroptosis within various diseases. This pivotal facet underscores the burgeoning possibilities for manipulating ferroptosis as a therapeutic strategy. In summary, this review enriched the insights of both investigators and practitioners, while fostering an elevated comprehension of ferroptosis and its latent translational utilities. By revealing the basic processes and investigating treatment possibilities, this review provides a crucial resource for scientists and medical practitioners, aiding in a deep understanding of ferroptosis and its effects in various disease situations.

Inflammation-related signaling pathways in tendinopathy

Tendon is a connective tissue that produces movement by transmitting the force produced by muscle contraction to the bones. Most tendinopathy is caused by prolonged overloading of the tendon, leading to degenerative disease of the tendon. When overloaded, the oxygen demand of tenocytes increases, and the tendon structure is special and lacks blood supply, which makes it easier to form an oxygen-deficient environment in tenocytes. The production of reactive oxygen species due to hypoxia causes elevation of inflammatory markers in the tendon, including PGE2, IL-1β, and TNF-α. In the process of tendon healing, inflammation is also a necessary stage. The inflammatory environment formed by cytokines and various immune cells play an important role in the clearance of necrotic material, the proliferation of tenocytes, and the production of collagen fibers. However, excessive inflammation can lead to tendon adhesions and hinder tendon healing. Some important and diverse biological functions of the body originate from intercellular signal transduction, among which cytokine mediation is an important way of signal transduction. In particular, NF-κB, NLRP3, p38/MAPK, and signal transducer and activator of transcription 3, four common signaling pathways in tendinopathy inflammatory response, play a crucial role in the regulation and transcription of inflammatory factors. Therefore, summarizing the specific mechanisms of inflammatory signaling pathways in tendinopathy is of great significance for an in-depth understanding of the inflammatory response process and exploring how to inhibit the harmful part of the inflammatory response and promote the beneficial part to improve the healing effect of the tendon.

The COP9 signalosome reduces neuroinflammation and attenuates ischemic neuronal stress in organotypic brain slice culture model

The constitutive photomorphogenesis 9 (COP9) signalosome (CSN) is a deNEDDylase controlling ubiquitination activity of cullin-RING-E3 ligases (CRLs) and thus the levels of key cellular proteins. While the CSN and its catalytic subunit CSN5 have been extensively studied in cancer, its role in inflammatory and neurological diseases is less understood. Following verification that CSN5 is expressed in mouse and human brain, here we studied the role of the CSN in neuroinflammation and ischemic neuronal damage employing models of relevant brain-resident cell types, an ex vivo organotypic brain slice culture model, and the CRL NEDDylation state-modifying drugs MLN4924 and CSN5i-3, which mimic and inhibit, respectively, CSN5 deNEDDylase activity. Untargeted mass spectrometry-based proteomics revealed that MLN4924 and CSN5i-3 substantially alter the microglial proteome, including inflammation-related proteins. Applying these drugs and mimicking microglial and endothelial inflammation as well as ischemic neuronal stress by TNF and oxygen-glucose-deprivation/reoxygenation (OGD/RO) treatment, respectively, we could link CSN5/CSN-mediated cullin deNEDDylation to reduction of microglial inflammation, attenuated cerebral endothelial inflammation, improved barrier integrity, as well as protection from ischemic stress-induced neuronal cell death. Specifically, MLN4924 reduced phagocytic activity, motility, and inflammatory cytokine expression of microglial cells, and this was linked to inhibition of inflammation-induced NF-κB and Akt signaling. Inversely, Csn5 knockdown and CSN5i-3 increased NF-κB signaling. Moreover, MLN4924 abrogated TNF-induced NF-κB signaling in cerebral microvascular endothelial cells (hCMECs) and rescued hCMEC monolayers from OGD/RO-triggered barrier leakage, while CSN5i-3 exacerbated permeability. In an ex vivo organotypic brain slice model of ischemia/reperfusion stress, MLN4924 protected from neuronal death, while CSN5i-3 impaired neuronal survival. Neuronal damage was attributable to microglial activation and inflammatory cytokines, as indicated by microglial shape tracking and TNF-blocking experiments. Our results indicate a protective role of the CSN in neuroinflammation via brain-resident cell types involved in ischemic brain disease and implicate CSN activity-mimicking deNEDDylating drugs as potential therapeutics.

Bojungikgi-tang improves skin barrier function and immune response in atopic dermatitis mice fed a low aryl hydrocarbon receptor ligand diet

BACKGROUND

The aryl hydrocarbon receptor (AhR) is a transcription factor that plays a crucial role in regulating the immune system and maintaining skin barrier function. AhR signaling is pivotal in the pathogenesis of inflammatory diseases such as atopic dermatitis (AD), and the absence of AhR ligands further contributes to the progression or worsening of AD symptoms.

METHODS

AD was induced with 2,4-dinitrochlorobenzene (DNCB), and Bojungikgi-tang (BJIKT) was administered orally daily for 10 weeks. Serum IgE, splenocyte IL-4, and IFN-γ levels, skin barrier genes, and AhR target gene expressions were analyzed using RNA-sequencing analysis. Spleen tissues were extracted for fluorescence-activated cell sorting (FACS) analysis to analyze the effect of BJIKT on immune responses. A correlation analysis was conducted to analyze the correlation between immune markers and skin barrier genes and AhR target genes.

RESULTS

BJIKT effectively improved AD symptoms in AD mice fed a low AhR ligand diet by reducing neutrophil and eosinophil counts, lowering IgE levels in the blood, and decreasing IL-4 and IFN-γ levels in the splenocytes. Additionally, BJIKT significantly reduced epithelial skin thickness and transepidermal water loss (TEWL) values and reversed the decreased expression of skin barrier genes. BJIKT also considerably altered the expression of AhR target genes, including Ahr, Ahrr, cytochrome P450 1A1 (CYP1A1), and CYP1B1. Furthermore, AhR target pathway genes were negatively correlated with immune cell subtypes, including CD4 + and CD8 + T cells and macrophages (CD11b + F4/80 +) at the systemic level.

CONCLUSIONS

BJIKT can regulate AhR activation and may help reduce inflammation in AD by regulating the expression of skin barrier genes and immune responses.

The great potential of flavonoids as candidate drugs for NAFLD

Non-alcoholic fatty liver disease (NAFLD) has a global prevalence of approximately 25 % and is associated with high morbidity and high mortality. NAFLD is a leading cause of cirrhosis and hepatocellular carcinoma. Its pathophysiology is complex and still poorly understood, and there are no drugs used in the clinic to specifically treat NAFLD. Its pathogenesis involves the accumulation of excess lipids in the liver, leading to lipid metabolism disorders and inflammation. Phytochemicals with the potential to prevent or treat excess lipid accumulation have recently received increasing attention, as they are potentially more suitable for long-term use than are traditional therapeutic compounds. In this review, we summarize the classification, biochemical properties, and biological functions of flavonoids and how they are used in the treatment of NAFLD. Highlighting the roles and pharmacological uses of these compounds will be of importance for enhancing the prevention and treatment of NAFLD.

Construction of a Triple-Gene Deletion Mutant of Orf Virus and Evaluation of Its Safety, Immunogenicity and Protective Efficacy

Contagious ecthyma is a zoonotic disease caused by the orf virus (ORFV). Since there is no specific therapeutic drug available, vaccine immunization is the main tool to prevent and control the disease. Previously, we have reported the construction of a double-gene deletion mutant of ORFV (rGS14ΔCBPΔGIF) and evaluated it as a vaccine candidate. Building on this previous work, the current study reports the construction of a new vaccine candidate, generated by deleting a third gene (gene 121) to generate ORFV rGS14ΔCBPΔGIFΔ121. The in vitro growth characteristics, as well as the in vivo safety, immunogenicity, and protective efficacy, were evaluated. RESULTS: There was a minor difference in viral replication and proliferation between ORFV rGS14ΔCBPΔGIFΔ121 and the other two strains. ORFV rGS14ΔCBPΔGIFΔ121 induced continuous differentiation of PBMC to CD4⁺T cells, CD8⁺T cells and CD80⁺CD86⁺ cells and caused mainly Th1-like cell-mediated immunity. By comparing the triple-gene deletion mutant with the parental strain and the double-gene deletion mutant, we found that the safety of both the triple-gene deletion mutant and the double-gene deletion mutant could reach 100% in goats, while the safety of parental virus was only 50% after continually observing immunized animals for 14 days. A virulent field strain of ORFV from an ORF scab was used in the challenge experiment by inoculating the virus to the hairless area of the inner thigh of immunized animals. The result showed that the immune protection rate of triple-gene deletion mutant, double-gene mutant, and the parental virus was 100%, 66.7%, and 28.6%, respectively. In conclusion, the safety, immunogenicity, and immune-protectivity of the triple-gene deletion mutant were greatly improved to 100%, making it an excellent vaccine candidate.

Protective effects of an electrophilic metabolite of docosahexaenoic acid on UVB-induced oxidative cell death, dermatitis, and carcinogenesis

Docosahexaenoic acid (DHA), a representative omega-3 (ω-3) polyunsaturated fatty acids, undergoes metabolism to produce biologically active electrophilic species. 17-Oxo-DHA is one such reactive metabolite generated from DHA by cyclooxygenase-2 and dehydrogenase in activated macrophages. The present study was aimed to investigate the effects of 17-oxo-DHA on ultraviolet B (UVB)-induced oxidative stress, inflammation, and carcinogenesis in mouse skin. UVB-induced epidermal cell death was ameliorated by topically applied 17-oxo-DHA. Topical application of 17-oxo-DHA onto hairless mouse skin inhibited UVB-induced phosphorylation of the proinflammatory transcription factor, STAT3 on tyrosine 705 (Tyr705). The 17-oxo-DHA treatment also reduced the levels of oxidative stress markers, 4-hydroxynonenal-modified protein, malondialdehyde, and 8-oxo-2'-deoxyguanosine. The protective effects of 17-oxo-DHA against oxidative damage in UVB-irradiated mouse skin were associated with activation of Nrf2. 17-Oxo-DHA enhanced the engulfment of apoptotic JB6 cells by macrophages, which was related to the increased expression of the scavenger receptor CD36. The 17-oxo-DHA-mediated potentiation of efferocytic activity of macrophages was attenuated by the pharmacologic inhibition or knockout of Nrf2. The pretreatment with 17-oxo-DHA reduced the UVB-induced skin carcinogenesis and tumor angiogenesis. It was also confirmed that 17-oxo-DHA treatment significantly inhibited the phosphorylation of the Tyr705 residue of STAT3 and decreased the expression of its target proteins in cutaneous papilloma. In conclusion, 17-oxo-DHA protects against UVB-induced oxidative cell death, dermatitis, and carcinogenesis. These effects were associated with inhibition of STAT3-mediated proinflammatory signaling and also activation of Nrf2 with subsequent upregulation of antioxidant and anti-inflammatory gene expression.

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.

Purification of PaTx-II from the Venom of the Australian King Brown Snake and Characterization of Its Antimicrobial and Wound Healing Activities

Infections caused by multi-drug-resistant (MDR) bacteria are a global threat to human health. As venoms are the source of biochemically diverse bioactive proteins and peptides, we investigated the antimicrobial activity and murine skin infection model-based wound healing efficacy of a 13 kDa protein. The active component PaTx-II was isolated from the venom of Pseudechis australis (Australian King Brown or Mulga Snake). PaTx-II inhibited the growth of Gram-positive bacteria in vitro, with moderate potency (MICs of 25 µM) observed against S. aureus, E. aerogenes, and P. vulgaris. The antibiotic activity of PaTx-II was associated with the disruption of membrane integrity, pore formation, and lysis of bacterial cells, as evidenced by scanning and transmission microscopy. However, these effects were not observed with mammalian cells, and PaTx-II exhibited minimal cytotoxicity (CC50 > 1000 µM) toward skin/lung cells. Antimicrobial efficacy was then determined using a murine model of S. aureus skin infection. Topical application of PaTx-II (0.5 mg/kg) cleared S. aureus with concomitant increased vascularization and re-epithelialization, promoting wound healing. As small proteins and peptides can possess immunomodulatory effects to enhance microbial clearance, cytokines and collagen from the wound tissue samples were analyzed by immunoblots and immunoassays. The amounts of type I collagen in PaTx-II-treated sites were elevated compared to the vehicle controls, suggesting a potential role for collagen in facilitating the maturation of the dermal matrix during wound healing. Levels of the proinflammatory cytokines interleukin-1β (IL-1β), interleukin-6 (IL-6) and tumor necrosis factor-α (TNF-α), cyclooxygenase-2 (COX-2) and interleukin-10 (IL-10), factors known to promote neovascularization, were substantially reduced by PaTx-II treatment. Further studies that characterize the contributions towards efficacy imparted by in vitro antimicrobial and immunomodulatory activity with PaTx-II are warranted.

Gut microbiota involved in myocardial dysfunction induced by sepsis

Myocardial dysfunction is an important complication of sepsis and an important cause of death in sepsis patients. Sepsis will significantly change the composition of gut microbiota, and the destruction of gut microbiota also creates conditions for the occurrence and progression of sepsis. Gut microbiota is an important player in myocardial injury in sepsis. This review elaborates on the possible mechanisms of gut microbiota affecting myocardial injury in sepsis, including short-chain fatty acids, trimethylamine and trimethylamine oxides, various cytokines, and mitochondrial dysfunction. A better understanding of the mechanism could help improve the treatment of sepsis and get a better prognosis for sepsis patients.

NEMO- and RelA-dependent NF-κB signaling promotes small cell lung cancer

Small cell lung cancer (SCLC) is an aggressive type of lung cancer driven by combined loss of the tumor suppressors RB1 and TP53. SCLC is highly metastatic and despite good initial response to chemotherapy patients usually relapse, resulting in poor survival. Therefore, better understanding of the mechanisms driving SCLC pathogenesis is required to identify new therapeutic targets. Here we identified a critical role of the IKK/NF-κB signaling pathway in SCLC development. Using a relevant mouse model of SCLC, we found that ablation of NEMO/IKKγ, the regulatory subunit of the IKK complex that is essential for activation of canonical NF-κB signaling, strongly delayed the onset and growth of SCLC resulting in considerably prolonged survival. In addition, ablation of the main NF-κB family member p65/RelA also delayed the onset and growth of SCLC and prolonged survival, albeit to a lesser extent than NEMO. Interestingly, constitutive activation of IKK/NF-κB signaling within the tumor cells did not exacerbate the pathogenesis of SCLC, suggesting that endogenous NF-κB levels are sufficient to fully support tumor development. Moreover, TNFR1 deficiency did not affect the development of SCLC, showing that TNF signaling does not play an important role in this tumor type. Taken together, our results revealed that IKK/NF-κB signaling plays an important role in promoting SCLC, identifying the IKK/NF-κB pathway as a promising therapeutic target.

Impact of Copper Nanoparticles and Copper Ions on Transcripts Involved in Neural Repair Mechanisms in Rainbow Trout Olfactory Mucosa

Olfactory mucosa is well known for its lifelong ability for regeneration. Regeneration of neurons and regrowth of severed axons are the most common neural repair mechanisms in olfactory mucosa. Nonetheless, exposure to neurotoxic contaminants, such as copper nanoparticles (CuNPs) and copper ions (Cu²⁺), may alter the reparative capacity of olfactory mucosa. Here, using RNA-sequencing, we investigated the molecular basis of neural repair mechanisms that were affected by CuNPs and Cu²⁺ in rainbow trout olfactory mucosa. The transcript profile of olfactory mucosa suggested that regeneration of neurons was inhibited by CuNPs. Exposure to CuNPs reduced the transcript abundances of pro-inflammatory proteins which are required to initiate neuroregeneration. Moreover, the transcript of genes encoding regeneration promoters, including canonical Wnt/β-catenin signaling proteins and developmental transcription factors, were downregulated in the CuNP-treated fish. The mRNA levels of genes regulating axonal regrowth, including the growth-promoting signals secreted from olfactory ensheathing cells, were mainly increased in the CuNP treatment. However, the reduced transcript abundances of a few cell adhesion molecules and neural polarity genes may restrict axonogenesis in the CuNP-exposed olfactory mucosa. In the Cu²⁺-treated olfactory mucosa, both neural repair strategies were initiated at the transcript level. The stimulation of repair mechanisms can lead to the recovery of Cu²⁺-induced olfactory dysfunction. These results indicated CuNPs and Cu²⁺ differentially affected the neural repair mechanism in olfactory mucosa. Exposure to CuNP had greater effects on the expression of genes involved in olfactory repair mechanisms relative to Cu²⁺ and dysregulated the transcripts associated with stem cell proliferation and neural reconstitution.

Enhancement of IgA production by membrane vesicles derived from Bifidobacterium longum subsp. infantis

Immunoglobulin A (IgA) is involved in the maintenance of gut homeostasis. Although the oral administration of bifidobacteria increases the amount of fecal IgA, the effects of bifidobacteria on intestinal immunity remain unclear. We found and characterized membrane vesicles (MVs) derived from Bifidobacterium longum subsp. infantis toward host immune cells. Bifidobacterium infantis MVs consisted of a cytoplasmic membrane, and extracellular solute-binding protein (ESBP) was specifically detected. In the presence of B. infantis MVs or recombinant ESBP, RAW264 cells produced the pro-inflammatory cytokine IL-6. IgA was produced by Peyer's patches cells following the addition of B. infantis MVs. Therefore, ESBP of B. infantis MVs is involved in the production of IgA by acquired immune cells via the production of IL-6 by innate immune cells.

Distinct gene programs underpinning disease tolerance and resistance in influenza virus infection

When challenged with an invading pathogen, the host-defense response is engaged to eliminate the pathogen (resistance) and to maintain health in the presence of the pathogen (disease tolerance). However, the identification of distinct molecular programs underpinning disease tolerance and resistance remained obscure. We exploited transcriptional and physiological monitoring across 33 mouse strains, during in vivo influenza virus infection, to identify two host-defense gene programs-one is associated with hallmarks of disease tolerance and the other with hallmarks of resistance. Both programs constitute generic responses in multiple mouse and human cell types. Our study describes the organizational principles of these programs and validates Arhgdia as a regulator of disease-tolerance states in epithelial cells. We further reveal that the baseline disease-tolerance state in peritoneal macrophages is associated with the pathophysiological response to injury and infection. Our framework provides a paradigm for the understanding of disease tolerance and resistance at the molecular level.

A novel IRAK4/PIM1 inhibitor ameliorates rheumatoid arthritis and lymphoid malignancy by blocking the TLR/MYD88-mediated NF-κB pathway

Interleukin-1 receptor-associated kinase 4 (IRAK4) is a pivotal enzyme in the Toll-like receptor (TLR)/MYD88 dependent signaling pathway, which is highly activated in rheumatoid arthritis tissues and activated B cell-like diffuse large B-cell lymphoma (ABC-DLBCL). Inflammatory responses followed by IRAK4 activation promote B-cell proliferation and aggressiveness of lymphoma. Moreover, proviral integration site for Moloney murine leukemia virus 1 (PIM1) functions as an anti-apoptotic kinase in propagation of ABC-DLBCL with ibrutinib resistance. We developed a dual IRAK4/PIM1 inhibitor KIC-0101 that potently suppresses the NF-κB pathway and proinflammatory cytokine induction in vitro and in vivo. In rheumatoid arthritis mouse models, treatment with KIC-0101 significantly ameliorated cartilage damage and inflammation. KIC-0101 inhibited the nuclear translocation of NF-κB and activation of JAK/STAT pathway in ABC-DLBCLs. In addition, KIC-0101 exhibited an anti-tumor effect on ibrutinib-resistant cells by synergistic dual suppression of TLR/MYD88-mediated NF-κB pathway and PIM1 kinase. Our results suggest that KIC-0101 is a promising drug candidate for autoimmune diseases and ibrutinib-resistant B-cell lymphomas.

Neuroinflammation Plays a Critical Role in Cerebral Cavernous Malformation Disease

BACKGROUND

Cerebral cavernous malformations (CCMs) are neurovascular lesions caused by loss of function mutations in 1 of 3 genes, including KRIT1 (CCM1), CCM2, and PDCD10 (CCM3). CCMs affect ≈1 out of 200 children and adults, and no pharmacologic therapy is available. CCM lesion count, size, and aggressiveness vary widely among patients of similar ages with the same mutation or even within members of the same family. However, what determines the transition from quiescent lesions into mature and active (aggressive) CCM lesions is unknown.

METHODS

We use genetic, RNA-sequencing, histology, flow cytometry, and imaging techniques to report the interaction between CCM endothelium, astrocytes, leukocytes, microglia/macrophages, neutrophils (CCM endothelium, astrocytes, leukocytes, microglia/macrophages, neutrophils interaction) during the pathogenesis of CCMs in the brain tissue.

RESULTS

Expression profile of astrocytes in adult mouse brains using translated mRNAs obtained from the purification of EGFP (enhanced green fluorescent protein)-tagged ribosomes (Aldh1l1-EGFP/Rpl10a) in the presence or absence of CCM lesions (Slco1c1-iCreERT2;Pdcd10fl/fl; Pdcd10BECKO) identifies a novel gene signature for neuroinflammatory astrocytes. CCM-induced reactive astrocytes have a neuroinflammatory capacity by expressing genes involved in angiogenesis, chemotaxis, hypoxia signaling, and inflammation. RNA-sequencing analysis on RNA isolated from brain endothelial cells in chronic Pdcd10BECKO mice (CCM endothelium), identified crucial genes involved in recruiting inflammatory cells and thrombus formation through chemotaxis and coagulation pathways. In addition, CCM endothelium was associated with increased expression of Nlrp3 and Il1b. Pharmacological inhibition of NLRP3 (NOD [nucleotide-binding oligomerization domain]-' LRR [leucine-rich repeat]- and pyrin domain-containing protein 3) significantly decreased inflammasome activity as assessed by quantification of a fluorescent indicator of caspase-1 activity (FAM-FLICA [carboxyfluorescein-fluorochrome-labeled inhibitors of caspases] caspase-1) in brain endothelial cells from Pdcd10BECKO in chronic stage. Importantly, our results support the hypothesis of the crosstalk between astrocytes and CCM endothelium that can trigger recruitment of inflammatory cells arising from brain parenchyma (microglia) and the peripheral immune system (leukocytes) into mature active CCM lesions that propagate lesion growth, immunothrombosis, and bleedings. Unexpectedly, partial or total loss of brain endothelial NF-κB (nuclear factor κB) activity (using Ikkbfl/fl mice) in chronic Pdcd10BECKO mice does not prevent lesion genesis or neuroinflammation. Instead, this resulted in a trend increase in the number of lesions and immunothrombosis, suggesting that therapeutic approaches designed to target inflammation through endothelial NF-κB inhibition may contribute to detrimental side effects.

CONCLUSIONS

Our study reveals previously unknown links between neuroinflammatory astrocytes and inflamed CCM endothelium as contributors that trigger leukocyte recruitment and precipitate immunothrombosis in CCM lesions. However, therapeutic approaches targeting brain endothelial NF-κB activity may contribute to detrimental side effects.

Therapeutic Targeting of NF-κB in Acute Lung Injury: A Double-Edged Sword

Acute lung injury/acute respiratory distress syndrome (ALI/ARDS) is a devastating disease that can be caused by a variety of conditions including pneumonia, sepsis, trauma, and most recently, COVID-19. Although our understanding of the mechanisms of ALI/ARDS pathogenesis and resolution has considerably increased in recent years, the mortality rate remains unacceptably high (~40%), primarily due to the lack of effective therapies for ALI/ARDS. Dysregulated inflammation, as characterized by massive infiltration of polymorphonuclear leukocytes (PMNs) into the airspace and the associated damage of the capillary-alveolar barrier leading to pulmonary edema and hypoxemia, is a major hallmark of ALI/ARDS. Endothelial cells (ECs), the inner lining of blood vessels, are important cellular orchestrators of PMN infiltration in the lung. Nuclear factor-kappa B (NF-κB) plays an essential role in rendering the endothelium permissive for PMN adhesion and transmigration to reach the inflammatory site. Thus, targeting NF-κB in the endothelium provides an attractive approach to mitigate PMN-mediated vascular injury, not only in ALI/ARDS, but in other inflammatory diseases as well in which EC dysfunction is a major pathogenic mechanism. This review discusses the role and regulation of NF-κB in the context of EC inflammation and evaluates the potential and problems of targeting it as a therapy for ALI/ARDS.

Vildagliptin alleviates liver fibrosis in NASH diabetic rats via modulation of insulin resistance, oxidative stress, and inflammatory cascades

AIMS

This study investigates the therapeutic potential of Vilda in a NASH model with liver fibrosis and elucidates the underlying molecular mechanisms.

MAIN METHODS

To induce NASH, male Sprague-Dawley rats were fed a high-fat diet for 24 weeks with a single dose of STZ (40 mg/kg, IP). Vilda was orally administered at two doses (10 and 20 mg/kg) for 20 weeks.

KEY FINDINGS

The induction of NASH was validated by abnormalities in hepatotoxicity indices, lipid profile, oxidative stress markers, and pathologically by marked fat deposition in hepatic tissues together with severe inflammatory cell infiltration. Moreover, NASH-affected rats demonstrated reduced insulin sensitivity manifested as elevated fasting blood glucose levels and disrupted homeostasis model assessment for insulin resistance. Vilda, at both doses, effectively abrogated all these pathological features of NASH. Mechanistically, these hepatoprotective properties of Vilda can be attributed to its antioxidant effects, anti-inflammatory effects (by inhibiting the TNF-α, NF-κB, JNK, and JAK/STAT pathways), and insulin-sensitizing effect (by upregulating the IRS-1/PI3K/Akt pathway). Besides, Vilda successfully counteracted NASH-associated liver fibrosis by downregulating the TGF-β1 pathway.

SIGNIFICANCE

The hepatoprotective and antifibrotic effects of Vilda were mostly dose-dependent. Collectively, this study offered a promising therapeutic avenue for Vilda as a novel strategy for counteracting the pathological progression of NASH and associated liver fibrosis.

NF-κB-coupled IL17 mediates inflammatory signaling and intestinal inflammation in Artemia sinica

Nuclear factor-κB (NF-κB) plays a role as a rheostatic transcription factor in regulating intestinal inflammation, and its disruption or constitutive activation leads to inflammation and injury. However, the molecular mechanisms of NF-κB regulation remain largely unknown. In this study, the NF-κB-regulated host defenses against pathogen infections and facilitation of IL17 expression during stimulation with different bacteria were investigated. Intestinal inflammation was induced by dextran sulfate sodium, and NF-κB activity was inhibited in an intestinal injury model. Mannose receptor C type, ABF1/2, serpin B13, lysozyme, and β-arrestin were significantly controlled by NF-κB in the inflamed intestinal tissue. High levels of NF-κB activation resulted in less pervasive intestinal damage and the maintenance of intestinal barrier integrity. Intestinal injury robustly increased the expression of IL17. NF-κB activation was enhanced by IL17 deficiency in the intestinal injury model. IL17 inhibition aggravated intestinal inflammation, leading to loss of epithelial architecture and the infiltration of inflammatory cells. These data suggest that NF-κB and IL17 play key mediator roles in the maintenance of gut epithelial integrity and immune homeostasis.

Uptake and Immunomodulatory Properties of Betanin, Vulgaxanthin I and Indicaxanthin towards Caco-2 Intestinal Cells

The present study aimed to compare the absorption and transport patterns of three main betalains, betanin, vulgaxanthin I and indicaxanthin, into intestinal epithelial cells and to assess their distinct molecular effects on inflammatory and redox-related cell signalling in association with their radial scavenging potencies. All three betalains showed anti-inflammatory effects (5–80 μM), reflected by attenuated transcription of pro-inflammatory mediators such as cyclooxygenase-2 and inducible NO-synthase. Concomitant increases in antioxidant enzymes such as heme oxygenase-1 were only observed for betanin. Moreover, betanin uniquely demonstrated a potent dose-dependent radical scavenging activity in EPR and cell-based assays. Results also indicated overall low permeability for the three betalains with P_app of 4.2–8.9 × 10⁻⁷ cm s⁻¹. Higher absorption intensities of vulgaxanthin and indicaxanthin may be attributed to smaller molecular sizes and greater lipophilicity. In conclusion, betanin, vulgaxanthin I and indicaxanthin have differentially contributed to lowering inflammatory markers and mitigating oxidative stress, implying the potential to ameliorate inflammatory intestinal disease. Compared with two betaxanthins, the greater efficacy of betanin in scavenging radical and promoting antioxidant response might, to some extent, compensate for its poorer absorption efficiency, as demonstrated by the Caco-2 cell model.

Characterization of extracellular vesicles from Lactiplantibacillus plantarum

We investigated the characteristics and functionalities of extracellular vesicles (EVs) from Lactiplantibacillus plantarum (previously Lactobacillus plantarum) towards host immune cells. L. plantarum produces EVs that have a cytoplasmic membrane and contain cytoplasmic metabolites, membrane and cytoplasmic proteins, and small RNAs, but not bacterial cell wall components, namely, lipoteichoic acid and peptidoglycan. In the presence of L. plantarum EVs, Raw264 cells inducibly produced the pro-inflammatory cytokines IL-1β and IL-6, the anti-inflammatory cytokine IL-10, and IF-γ and IL-12, which are involved in the differentiation of naive T-helper cells into T-helper type 1 cells. IgA was produced by PP cells following the addition of EVs. Therefore, L. plantarum EVs activated innate and acquired immune responses. L. plantarum EVs are recognized by Toll-like receptor 2 (TLR2), which activates NF-κB, but not by other TLRs or NOD-like receptors. N-acylated peptides from lipoprotein19180 (Lp19180) in L. plantarum EVs were identified as novel TLR2 ligands. Therefore, L. plantarum induces an immunostimulation though the TLR2 recognition of the N-acylated amino acid moiety of Lp19180 in EVs. Additionally, we detected a large amount of EVs in the rat gastrointestinal tract for the first time, suggesting that EVs released by probiotics function as a modulator of intestinal immunity.

Proteomics analysis of chronic skin injuries caused by mustard gas

Sulfur mustard (SM) is an alkylating and forming chemical that was widely used by Iraqi forces during the Iran–Iraq wars. One of the target organs of SM is the skin. Understanding the mechanisms involved in the pathogenesis of SM may help better identify complications and find appropriate treatments. The current study collected ten SM-exposed patients with long-term skin complications and ten healthy individuals. Proteomics experiments were performed using the high-efficiency TMT10X method to evaluate the skin protein profile, and statistical bioinformatics methods were used to identify the differentially expressed proteins. One hundred twenty-nine proteins had different expressions between the two groups. Of these 129 proteins, 94 proteins had increased expression in veterans' skins, while the remaining 35 had decreased expression. The hub genes included RPS15, ACTN1, FLNA, HP, SDHC, and RPL29, and three modules were extracted from the PPI network analysis. Skin SM exposure can lead to oxidative stress, inflammation, apoptosis, and cell proliferation.

Dexmedetomidine Inhibits NF-κB-Transcriptional Activity in Neurons Undergoing Ischemia-Reperfusion by Regulating O-GlcNAcylation of SNW1

Dexmedetomidine (Dex) is neuroprotective in ischemia-reperfusion (I/R) by suppressing inflammation but the underlying molecular mechanisms are not known. SNW domain-containing protein 1 (SNW1) is a coactivator of the pro-inflammatory transcription factor NF-κB p65. Because SNW1 is regulated by O-GlcNAcylation, we aimed to determine whether this modification influences NF-κB transcriptional activity in neurons undergoing I/R and how Dex may affect the O-GlcNAcylation of SNW1. SH-SY5Y and PC12 cells under hypoxia/reoxygenation (H/R) conditions were treated with Dex and with inhibitors of O-GlcNAc transferase (OGT). O-GlcNAc levels in SNW1 and effects of SNW1 on NF-κB p65 were determined by immunoprecipitation. H/R increased SNW1 protein levels but inhibited O-GlcNAcylation of SNW1. A Luciferase reporter assay demonstrated that increased SNW1 levels led to increased NF-κB p65 activity and increased secretion of neuron-derived inflammatory factors demonstrated by ELISA. Dex reversed the H/R-induced increase of SNW1 protein by upregulating OGT and enhancing O-GlcNAcylation of SNW1. Dex suppression of the SNW1/NF-κB complex resulted in neuroprotection in vitro and in a middle cerebral artery occlusion model in vivo. PKA and ERK1/2 inhibitors abolished the effect of Dex on OGT protein. Taken together, these data indicate that Dex inhibits NF-κB-transcriptional activity in neurons undergoing I/R by regulating O-GlcNAcylation of SNW1.

Genome-wide identification and analysis of scavenger receptors and their expression profiling in response to Edwardsiella tarda infection in Japanese flounder (Paralichthys olivaceus)

The scavenger receptors (SRs) gene family, as one of pattern recognition receptors, participates in the innate immune response in diverse lineages. However, the systematic identification, characteristics and functions of SRs family are lacking in teleost. Here, we identified all 19 SRs family members in Japanese flounder (Paralichthys olivaceus) based on the genome and transcriptome data. Phylogenetic and Ka/Ks analysis demonstrated that these SRs genes were divided into five classes and all exhibited pronounced purified selection pressures. Whole genome duplication event was found in colec12, scarb2, and lamp1. Gene structure, functional domain and motif distribution analyses indicated that SRs within the different subfamilies are severely conservative. SRs genes showed diverse expression patterns in the embryogenesis and unchanged tissues. The regulations of 14 SRs genes in blood, gill and kidney after E. tarda infection suggested their roles in innate immune response. Meanwhile, ten SRs genes were differentially expressed after E. tarda stimulation in macrophages in vitro. Then we proved that PoSCARA3 could suppress the activity of NF-κB and AP-1 in HEK 293T cells by dual-luciferase assays. In summary, this study provided valuable basis for further functional characterization and immune functions of SRs genes in P. olivaceus.

NF-κB Regulation by Gut Microbiota Decides Homeostasis or Disease Outcome During Ageing

Human beings and their indigenous microbial communities have coexisted for centuries, which led to the development of co-evolutionary mechanisms of communication and cooperation. Such communication machineries are governed by sophisticated multi-step feedback loops, which typically begin with the recognition of microbes by pattern recognition receptors (PRRs), followed by a host transcriptional response leading to the release of effector molecules. Our gastrointestinal tract being the main platform for this interaction, a variety of host intestinal cells tightly regulate these loops to establish tolerance towards the microbial communities of the gut and maintain homeostasis. The transcription factor, nuclear factor kappa B (NF-κB) is an integral component of such a communication apparatus, which plays a critical role in determining the state of homeostasis or inflammation associated with dysbiosis in the host. Here we outline the crucial role of NF-κB in host response to microbial cues in the context of ageing and associated diseases.

Nuclear factor-kappa B and effector molecules in photoaging

Nuclear factor-kappa B (NF-κB) has important but complex functions in the photoaging of the human skin. This protein complex is activated upon UV irradiation and plays a key role in the signalling pathway of the inflammatory cascade. NF-κB induces the expression of various proinflammatory cytokines, such as tumour necrosis factor (TNF) and interleukin-1 (IL-1). These proinflammatory cytokines can in turn stimulate the activation of NF-κB, forming a vicious cycle. These processes cause chronic inflammation and contribute to skin ageing. In addition, the activation of NF-κB upregulates the expression of matrix metalloproteinases (MMPs) and leads to the degradation of structural proteins in the dermis. NF-κB disrupts the barrier function of the skin under prolonged and repeated UV stimulations in these ways. Such activity causes chronic skin damage, followed by the formation of wrinkles, dryness, roughness, laxity, and other photoaging manifestations. This study on the NF-κB signalling pathway and effector molecules provides a new perspective to understand and prevent photoaging.

NF-κB: A Double-Edged Sword Controlling Inflammation

Inflammation, when properly mounted and precisely calibrated, is a beneficial process that enables the rapid removal of invading pathogens and/or cellular corpses and promotes tissue repair/regeneration to restore homeostasis after injury. Being a paradigm of a rapid response transcription factor, the nuclear factor-kappa B (NF-κB) transcription factor family plays a central role in amplifying inflammation by inducing the expression of inflammatory cytokines and chemokines. Additionally, NF-κB also induces the expression of pro-survival and -proliferative genes responsible for promoting tissue repair and regeneration. Paradoxically, recent studies have suggested that the NF-κB pathway can also exert inhibitory effects on pro-inflammatory cytokine production to temper inflammation. Here, we review our current understanding about the pro- and anti-inflammatory roles of NF-κB and discuss the implication of its dichotomous inflammation-modulating activity in the context of inflammasome activation and tumorigenesis.

New AKT-dependent mechanisms of anti-COVID-19 action of high-CBD Cannabis sativa extracts

COVID-19 is caused by the SARS-CoV-2 virus, which enters target cells via interactions with ACE2 and TMPRSS2. Here, we show AKT serine/threonine kinase-dependent epigenetic control of ACE2 and TMPRSS2 expression by high-cannabidiol (CBD) cannabis extracts and their individual components. CBD alone and extracts #1, #5, #7, and #129 downregulated ACE2 and TMPRSS2 in lung fibroblast WI-38 cells through AKT-mediated inhibition. miR-200c-3p and let-7a-5p were two contributing miRNAs in CBD-mediated suppression of ACE2 and TMPRSS2. CBD and terpene PTWT2.2 profoundly inhibited ACE2 and TMPRSS2 expression, both individually and in combination. Extracts #1, #5, #7, and #169 suppressed COX2 expression and remarkably attenuated TNFα/IFNγ-triggered induction of proinflammatory factors IL-6 and IL-8 by AKT pathway. The most abundant molecules present in extracts #1 and #7 modulated the expression of COX2, IL-6, and IL-8 both individually and in combination. These results reveal that high-CBD cannabis extracts attenuated ACE2 and TMPRSS2 expression and the induction of inflammatory mediators COX2, IL-6, and IL-8 via the AKT pathway, highlighting their potential anti-COVID-19 features.

Nucleic Acids for Potential Treatment of Rheumatoid Arthritis

Rheumatoid arthritis (RA) is a common systemic inflammatory autoimmune disease that severely affects the life quality of patients. Current therapeutics in clinic mainly focus on alleviating the development of RA or relieving the pain of patients. The emerging biological disease-modifying antirheumatic drugs (DMARDs) require long-term treatment to achieve the expected efficacy. With the development of bionanotechnology, nucleic acids fulfill characters as therapeutics or nanocarriers and can therefore be alternatives to combat RA. This review summarizes the therapeutic RNAs developed through RNA interference (RNAi), nucleic acid aptamers, DNA nanostructures-based drug delivery systems, and nucleic acid vaccines for the applications in RA therapy and diagnosis. Furthermore, prospects of nucleic acids for RA therapy are intensively discussed as well.

Role of EGF Receptor Regulatory Networks in the Host Response to Viral Infections

In this review article, we will first provide a brief overview of EGF receptor (EGFR) structure and function, and its importance as a therapeutic target in epithelial carcinomas. We will then compare what is currently known about canonical EGFR trafficking pathways that are triggered by ligand binding, versus ligand-independent pathways activated by a variety of intrinsic and environmentally induced cellular stresses. Next, we will review the literature regarding the role of EGFR as a host factor with critical roles facilitating viral cell entry and replication. Here we will focus on pathogens exploiting virus-encoded and endogenous EGFR ligands, as well as EGFR-mediated trafficking and signaling pathways that have been co-opted by wild-type viruses and recombinant gene therapy vectors. We will also provide an overview of a recently discovered pathway regulating non-canonical EGFR trafficking and signaling that may be a common feature of viruses like human adenoviruses which signal through p38-mitogen activated protein kinase. We will conclude by discussing the emerging role of EGFR signaling in innate immunity to viral infections, and how viral evasion mechanisms are contributing to our understanding of fundamental EGFR biology.

Adaptive homeostasis and the p53 isoform network

All living organisms have developed processes to sense and address environmental changes to maintain a stable internal state (homeostasis). When activated, the p53 tumour suppressor maintains cell and organ integrity and functions in response to homeostasis disruptors (stresses) such as infection, metabolic alterations and cellular damage. Thus, p53 plays a fundamental physiological role in maintaining organismal homeostasis. The TP53 gene encodes a network of proteins (p53 isoforms) with similar and distinct biochemical functions. The p53 network carries out multiple biological activities enabling cooperation between individual cells required for long‐term survival of multicellular organisms (animals) in response to an ever‐changing environment caused by mutation, infection, metabolic alteration or damage. In this review, we suggest that the p53 network has evolved as an adaptive response to pathogen infections and other environmental selection pressures.

Tendon healing is adversely affected by low-grade inflammation

BACKGROUND

Tendinopathy is common, presents with pain and activity limitation, and is associated with a high risk of recurrence of the injury. Tendinopathy usually occurs as a results of a disrupted healing response to a primary injury where cellular and molecular pathways lead to low grade chronic inflammation.

MAIN FINDINGS

There has been a renewed interest in investigating the role of Inflammation in the pathogenesis of tendinopathy, in particular during the initial phases of the condition where it may not be clinically evident. Understanding the early and late stages of tendon injury pathogenesis would help develop new and effective treatments addressed at targeting the inflammatory pathways.

CONCLUSION

This review outlines the role of low-grade Inflammation in the pathogenesis of tendinopathy, stressing the role of proinflammatory cytokines, proteolytic enzymes and growth factors, and explores how Inflammation exerts a negative influence on the process of tendon healing.