STAT3 activation in response to IL-6 is prolonged by the binding of IL-6 receptor to EGF receptor

Fibroblast EGFR signaling mediates ricin toxin-induced acute lung injury via EGR1/CXCL1 axis

Ricin toxin (RT), a highly potent plant-derived toxin, represents a critical threat due to its capacity to induce fatal acute lung injury (ALI) upon inhalation. While the epidermal growth factor receptor (EGFR), a receptor tyrosine kinase predominantly expressed on epithelial cells and fibroblasts, regulates cellular processes such as growth, proliferation, differentiation and inflammation, its involvement in RT-induced ALI remains unexplored. This study investigates this relationship using a mouse model of ALI induced by aerosolized RT at a dose of 2.0 × LD50 (approximately 0.01 mg kg -1). The results demonstrate that damage to alveolar epithelial type II (AT2) cells leads to the release of heparin-binding epidermal growth factor-like growth factor (HB-EGF), which activates EGFR on fibroblasts, exacerbating lung injury pathology and reducing survival. Mechanistically, EGFR activation in fibroblasts induces the early growth response protein 1 (EGR1), which subsequently enhances chemokine C-X-C motif ligand 1 (CXCL1) secretion 24 h post-exposure, promoting neutrophil infiltration in the lung. RNA sequencing analysis corroborates these findings. Notably, pharmacological inhibition of EGFR phosphorylation using Erlotinib (ERL) significantly mitigates the inflammatory response in RT-induced ALI. These results not only illuminate the immune response in lung tissue but also highlight EGFR signaling in fibroblasts as a pivotal mediator of RT-induced ALI. This study identifies a novel therapeutic strategy targeting EGFR signaling in fibroblasts for the treatment of inflammatory lung diseases.

Spatiotemporal Clusters of Extracellular Signal-Regulated Kinase Activity Coordinate Cytokine-induced Inflammatory Responses in Human Airway Epithelial Cells

Spatially coordinated extracellular signal-regulated kinase (ERK) signaling events (SPREADs) transmit radially from a central point to adjacent cells via secreted ligands for EGFR (epidermal growth factor receptor) and other receptors. SPREADs maintain homeostasis in nonpulmonary epithelia, but it is unknown whether they play a role in the airway epithelium or are dysregulated in inflammatory disease. To address these questions, we measured SPREAD activity with live-cell ERK biosensors in human bronchial epithelial cell lines (HBE1 and 16HBE) and primary human bronchial epithelial cells, in both submerged and biphasic air-liquid interface culture conditions (i.e., differentiated cells). Airway epithelial cells were exposed to proinflammatory cytokines relevant to asthma and chronic obstructive pulmonary disease. Type 1 proinflammatory cytokines significantly increased the frequency of SPREADs, which coincided with epithelial barrier breakdown in differentiated primary human bronchial epithelial cells. Furthermore, SPREADs correlated with IL-6 peptide secretion and the appearance of localized clusters of phospho-STAT3 immunofluorescence. To probe the mechanism of SPREADs, cells were cotreated with pharmacological treatments (gefitinib, tocilizumab, hydrocortisone) or metabolic modulators (insulin, 2-deoxyglucose). Hydrocortisone, inhibitors of receptor signaling, and suppression of metabolic function decreased SPREAD occurrence, implying that proinflammatory cytokines and glucose metabolism modulate SPREADs in human airway epithelial cells via secreted EGFR and IL6R ligands. We conclude that spatiotemporal ERK signaling plays a role in barrier homeostasis and dysfunction during inflammation of the airway epithelium. This novel signaling mechanism could be exploited clinically to supplement corticosteroid treatment for asthma and chronic obstructive pulmonary disease.

Role of mitogens in normal and pathological liver regeneration

The liver has a unique ability to regenerate to meet the body's metabolic needs, even following acute or chronic injuries. The cellular and molecular mechanisms underlying normal liver regeneration have been well investigated to improve organ transplantation outcomes. Once liver regeneration is impaired, pathological regeneration occurs, and the underlying cellular and molecular mechanisms require further investigations. Nevertheless, a plethora of cytokines and growth factor-mediated pathways have been reported to modulate physiological and pathological liver regeneration. Regenerative mitogens play an essential role in hepatocyte proliferation. Accelerator mitogens in synergism with regenerative ones promote liver regeneration following hepatectomy. Finally, terminator mitogens restore the proliferating status of hepatocytes to a differentiated and quiescent state upon completion of regeneration. Chronic loss of hepatocytes, which can manifest in chronic liver disorders of any etiology, often has undesired structural consequences, including fibrosis, cirrhosis, and liver neoplasia due to the unregulated proliferation of remaining hepatocytes. In fact, any impairment in the physiological function of the terminator mitogens results in the progression of pathological liver regeneration. In the current review, we intend to highlight the updated cellular and molecular mechanisms involved in liver regeneration and discuss the impairments in central regulating mechanisms responsible for pathological liver regeneration.

Integrating network pharmacology and in vivo pharmacological validation to explore the gastroprotective mechanism of Sotetsuflavone against indomethacin-induced gastric ulcer in rats: Involvement of JAK2/STAT3 pathway

Sotetsuflavone (SF) is an antioxidant flavonoid derived from the Cycas thouarsii R.Br. plant. Although SF regulates numerous cellular pathways influencing inflammation, its antiinflammatory benefits against gastric ulcers are less well-studied. Hence, it is imperative to thoroughly understand the potential gastroprotective mechanisms of SF. This study aimed to explore the effectiveness of SF against indomethacin (IND)-induced gastric ulcers. Network analysis and molecular docking were used to identify the specific targets and pathways related to SF and stomach ulcers. To validate the in vivo pharmacological action of SF, 36 rats were divided into six groups. Ulcer index (UI), protective percentage (PP), gastric mucosal mediators, oxidant/antioxidant status, and inflammatory markers (MIF, M-CSF, and AIF-1) were assessed. Additionally, the expression of PI3K, Akt, Siah2, SOCS3, JAK2, and STAT3 was determined. Stomach histopathology and immunohistochemistry were done. Network pharmacology detected 46 overlapping targets between SF and stomach ulcers, with HIF1A as the primary target among the top hubs. The network also revealed that JAK/STAT, PI3K/Akt, and HIF-1A signaling are among the top 50 markedly enriched KEGG pathways. Furthermore, docking results confirmed that SF has a strong binding affinity towards SOCS3, JAK2, STAT3, M-CSF (CSF-1), and AIF-1. Therefore, we hypothesized that the JAK2/STAT3 pathway may be primarily responsible for SF antiinflammatory action. Through up-regulating SOCS3, SF altered the PI3K/Akt pathway, mitigating oxidative stress, blocking the outflow of inflammatory mediators, and impeding gastric ulcer development. Overall, SF, by the SOCS3-mediated JAK2/STAT3 suppression, might considerably reduce oxidative stress, inflammation, and ulceration caused by indomethacin in the stomach.

Cell cycle disorders in podocytes: an emerging and increasingly recognized phenomenon

Proteinuria is observed in various kidney diseases and is frequently associated with a compromised glomerular filtration barrier. Podocytes, as a crucial component of this barrier, play an essential role in preserving the kidney's normal filtration function. Podocytes are terminally differentiated cells that typically do not proliferate. However, certain harmful stimuli can trigger podocytes to re-enter the cell cycle. Due to its unique cytoskeletal structure, podocytes are unable to maintain the structure of the foot process and complete cell division at the same time, eventually form binucleated or multinucleated podocytes. Studies have found that podocytes re-entering the cell cycle are more susceptible to injury, and are prone to detachment from the basement membrane or apoptosis, which are accompanied by the widening of foot processes. This eventually leads to podocyte mitotic catastrophe and the development of proteinuria. Podocyte cell cycle disorders have previously been found mainly in focal segmental glomerulosclerosis and IgA nephropathy. In recent years, this phenomenon has been frequently identified in diabetic kidney disease and lupus nephritis. An expanding body of research has begun to investigate the mechanisms underlying podocyte cell cycle disorders, including cell cycle re-entry, cell cycle arrest, and mitotic catastrophe. This review consolidates the existing literature on podocyte cell cycle disorders in renal diseases and summarizes the molecules that trigger podocyte re-entry into the cell cycle, thereby providing new drug targets for mitigating podocyte damage. This is essential for alleviating podocyte injury, reducing proteinuria, and delaying the progression of kidney diseases.

Human IL-6-Producing B Cells Promote the Differentiation of Monocytes Toward an Anti-Inflammatory CD16⁺CD163⁺CD206⁺PD-L1⁺ Phenotype in Tuberculosis

The polarization of the monocyte/macrophage compartment toward an anti-inflammatory profile is considered detrimental in tuberculosis (TB), but the factors controlling M2 polarization in this context are still poorly understood. Here, we found that B cells promote the differentiation of human monocytes toward an M2-like activation program through a process primarily dependent on IL-6 and the activation of STAT3 signaling in monocytes. This confers monocytes with immunomodulatory properties characterized by a reduced ability to produce proinflammatory cytokines and to stimulate IFNγ secretion by allogeneic T cells. Our findings were validated using B cells from TB patients, which constitutively produce high levels of IL-6, underscoring the clinical relevance of our experimental observations. Collectively, our results indicate that human B-cell-derived IL-6 might impair TB immunity by driving monocyte polarization toward an anti-inflammatory phenotype.

Banxia Xiexin Decoction inhibits colitis-associated colorectal cancer development by modulating STAT3 signaling and gut microbiota

Objective

To investigate the therapeutic effects of Banxia Xiexin Decoction (BXD), a herbal medicine formula, on inflammation and the imbalance of the gut microbiota in a rat model of colorectal cancer (CRC) induced by azoxymethane (AOM) /dextran sulfate sodium (DSS).

Methods

A total of 75 male C57BL/6 mice were randomly divided into five groups: normal control group (NC), model group (MODEL), low-dose BXD treatment group (L-BXD), high-dose BXD treatment (H-BXD) group and MS treatment group (MS). BXD and MS were used in CRC mice at the doses of 3.915 g/kg, 15.66 g/kg, 0.6 g/kg for 3 weeks consecutively. Histopathological changes in the colon were observed using hematoxylin-eosin (HE) staining. The content of inflammatory factors in serum was detected by an enzyme-linked immunosorbent assay (ELISA), and the expression of mRNA and protein of genes related to immunity, apoptosis, inflammation, and inflammatory factors was evaluated. Changes in the intestinal flora of mouse fecal were determined based on high-throughput sequencing of the 16S rRNA microbial gene.

Results

Compared to the model group, the low-dose BXD and high-dose BXD groups decreased the number of colon tumors, reversed weight loss, and shortened colon length of mice. The pathological examination showed that BXD alleviated the malignancy of intestinal tumors. It also suppressed signal transducer and activator of transcription 3 (STAT3), matrix metalloproteinase-9 (MMP-9), and transforming growth factor beta 1 (TGF-β1) expression, while increasing the expression of the tight junction protein ZO-1 in colon tissues. Additionally, the levels of key pathway proteins involved in inflammation (phosphorylated-STAT3, Bcl-2, COX-2) and cell cycle regulatory molecules (c-Myc and PCNA) were reduced. According to 16S rRNA sequence analysis, BXD enhanced the relative abundance of potentially beneficial bacteria, while that of cancer-related bacteria decreased.

Conclusion

BXD plays a preventive role in developing colorectal cancer; its mechanisms are related to the inhibition of inflammation and tumor proliferation, as well as maintenance of intestinal homeostasis.

The role and impact of the IL-6 mediated JAK2-STAT1/3 signaling pathway in the pathogenesis of gout

Background

Interleukin-6 (IL-6) is a pleiotropic cytokine, with specific effects depending on the immune microenvironment. Extensive research has confirmed the pathological roles of the IL-6/JAK2/STAT1/3 signaling pathway in inflammation, autoimmunity, and cancer, as well as its involvement in the pathogenesis of various rheumatic diseases. However, the role and impact of IL-6 as an upstream regulator of the JAK2-STAT1/3 pathway in gout have seldom been reported. This study explores the influence and role of upstream IL-6 in regulating the JAK2-STAT1/3 signaling pathway on gout inflammation, offering new insights for targeted therapeutic interventions and drug development in gout management.

Methods and Results

Clinical data and peripheral blood specimens were collected from gout patients and healthy individuals. In vitro and in vivo models of acute gout inflammation were established by stimulating PBMCs, THP-1 cells, and mice with MSU crystals. IL-6 expression was manipulated using IL-6 agonists and IL-6 knockout (KO) mouse technology to investigate the role and impact of the IL-6-mediated JAK2-STAT1/3 signaling pathway in gout models. RT-qPCR, WB, and ELISA were utilized to assess gene and protein expression levels. Paw swelling in mice was measured using a caliper gauge, while HE and IHC staining were conducted to evaluate the inflammatory status of mouse paw pad synovial tissues and detect the positive expression of relevant proteins. Serum IL-6 protein expression levels were significantly elevated in patients with gouty arthritis (GA) compared to healthy individuals, with multifactor logistic regression revealing an odds ratio (OR) of 2.175 for IL-6. In GA patients, mRNA expression of IL-6, JAK2, STAT1/3, and IL-1β was notably lower in the gout group compared to the healthy control (HC) group. Moreover, IL-6, JAK2, STAT1/3, p-JAK2, p-STAT1/3, and IL-1β proteins were markedly higher in the acute gout (AG) group compared to the intercritical gout (IG) and HC groups. Within the IG group, IL-6, JAK2, STAT3, and IL-1β proteins were significantly elevated compared to the HC group, whereas STAT1, p-JAK2, and p-STAT1/3 proteins were significantly lower. The expression of IL-6 protein and JAK2 mRNA showed positive correlations with certain inflammatory markers. In the 2h human blood in vitro gout inflammation model, expressions of IL-1β, IL-6, JAK2 mRNA, and IL-1β, IL-6, JAK2, STAT1/3, p-JAK2, p-STAT1/3 proteins were significantly higher compared to both the blank control and PBS-negative control groups. In the acute gout THP-1 cell model, The 6-hour model group showed significantly higher levels of IL-1β, IL-6, JAK2, STAT1/3 mRNA, and corresponding proteins, including their phosphorylated forms, compared to the blank control group. Additionally, treatment with an IL-6 agonist further increased these expression levels compared to the untreated model group. In the acute gout mouse model, IL-6 KO mice exhibited significantly reduced footpad swelling and swelling index compared to wild-type (WT) mice. HE staining revealed decreased inflammatory cell infiltration in IL-6 KO mice. Furthermore, Compared to 12-hour gout model WT mice, IL-1β, IL-6, JAK2, STAT1/3 mRNA, protein expression, and phosphorylated protein levels were notably decreased in IL-6 KO mice. IHC staining showed reduced positive expression of p-JAK2 and p-STAT1/3 in IL-6 KO mice. At the 24-hour mark, IL-6 mRNA and protein expression levels did not differ significantly between IL-6 KO and WT mice; however, IL-1β mRNA and protein expression, as well as JAK2 and STAT3 mRNA expression, were reduced in IL-6 KO mice, while STAT1 mRNA expression remained similar.

Conclusion

IL-6 emerges as a potential risk factor for acute gout attacks, with its involvement in the JAK2-STAT1/3 signaling pathway contributing to the inflammation and pathogenesis process of acute gout through positive feedback mechanisms.

IL-6 underlies microenvironment immunosuppression and resistance to therapy in glioblastoma

The glioblastoma tumor immune microenvironment (TIME) is an immunosuppressive barrier to therapy that encumbers glioblastoma responses to immune checkpoint inhibition (ICI). Immunosuppressive cytokines, pro-tumor myeloid cells, and exhausted T-cells are hallmarks of the glioblastoma TIME. Here we integrate spatial and single-cell analyses of patient-matched human glioblastoma samples before and after ICI with genetic, immunologic, single-cell, and pharmacologic studies in preclinical models to reveal that interleukin-6 (IL-6) inhibition reprograms the glioblastoma TIME to sensitize mouse glioblastoma to ICI and radiotherapy. Rare human glioblastoma patients who achieve clinical responses to ICI have lower pre-treatment IL-6 levels compared to glioblastomas who do not respond to ICI. Immune stimulatory gene therapy suppresses IL-6 tumor levels in preclinical murine models of glioblastoma. Furthermore, survival was longer in Il-6 knockout mice with orthotopic SB28 glioblastoma relative to wild-type mice. IL-6 blockade with a neutralizing antibody transiently sensitizes mouse glioblastoma to anti-PD-1 by increasing MHCII+ monocytes, CD103+ migratory dendritic cells (DCs), CD11b+ conventional DCs, and effector CD8+ T cells, and decreasing immunosuppressive Tregs. To translate these findings to a combination treatment strategy for recurrent glioblastoma patients, we show that IL-6 blockade plus ICI durably sensitizes mouse glioblastoma to high-dose radiotherapy.

Immunization induces inflammation in the mouse heart during spaceflight

Space travel is a growing area of interest and includes initiatives such as NASA's Moon-to-Mars Mission. Reports on the cardiovascular effects of space travel reveal changes in morphology, metabolism, and function of the cardiovascular system. In this study, the cardiovascular response to immunization in space was studied in mice which were housed and immunized while on the International Space Station (ISS). Mice were immunized with tetanus toxoid combined with the adjuvant CpG (TT + CpG) and the effects of vaccination in space were studied using transcriptomics. Analysis of the mouse heart transcriptome was performed on flight control and flight-immunized mice. The results show that immunization aboard the ISS stimulates heightened inflammation in the heart via induction of the nuclear factor kappa B (NF-κB) signaling pathway to promote the release of the pro-inflammatory cytokines IFNγ, IL-17 and IL-6. Additional transcriptomic changes included alterations in the cytoskeleton and in the expression of transcripts associated with protection from oxidative stress. In summary, inflammation in the heart can occur following immunization in space. This investigation explores the impact of immune challenges on the heart and lays the groundwork for future research into additional cardiac alterations which can occur during spaceflight.

In Silico Discovery of SARS-CoV-2 Main Protease Inhibitors Using Docking, Molecular Dynamics, and Fragment Molecular Orbital Calculations

The 3C-like protease of severe acute respiratory syndrome coronavirus 2, known as the main protease (Mpro), is an attractive drug target for the treatment of coronavirus disease 2019. This study reports the discovery of novel Mpro inhibitors using several in silico techniques, including docking, molecular dynamics (MD), and fragment molecular orbital (FMO) calculations. We performed docking calculations on 5950 compounds with bioactivity, and 12 compounds were selected. An enzymatic assay was conducted, revealing that BP-1-102 exhibits significant Mpro inhibitory activity with an IC50 of 11.1 μM. The identification of seed compounds from the experiments on a few compounds demonstrates the effectiveness of our docking calculations. Furthermore, the detailed analyses using MD and FMO calculations suggested an interaction mechanism in which the hydroxyl group of BP-1-102 forms a hydrogen bond with E166 of Mpro. The Mpro inhibitory activity of SH-4-54, a derivative without the aforementioned hydroxyl group, was investigated and observed to be significantly reduced, with an IC50 of 81.5 μM. This result strongly supports the suggested interaction mechanism.

CircUCK2(2,3) promotes cancer progression and enhances synergistic cytotoxicity of lenvatinib with EGFR inhibitors via activating CNIH4-TGFα-EGFR signaling

BACKGROUND

Circular (circ)RNAs have emerged as crucial contributors to cancer progression. Nonetheless, the expression regulation, biological functions, and underlying mechanisms of circRNAs in mediating hepatocellular carcinoma (HCC) progression remain insufficiently elucidated.

METHODS

We identified circUCK2(2,3) through circRNA sequencing, RT-PCR, and Sanger sequencing. CircUCK2(2,3) levels were measured in two independent HCC cohorts using quantitative real-time PCR (qRT-PCR). We explored the functions of circUCK2(2,3) using gain- and loss-of-function assays. Techniques such as RNA-sequencing, RNA immunoprecipitation (RIP), polysome fractionation, RNA pulldown, dual luciferase reporter assay, inhibitors of EGFR downstream signaling, CRISPR-Cas9, and medium transfer assays were employed to investigate the regulatory mechanisms and the protumoral activities of circUCK2(2,3). Additionally, in vitro cytotoxic assays and patient-derived xenograft (PDX) models assessed the effects of circUCK2(2,3) on the cytotoxic synergy of lenvatinib and EGFR inhibitors.

RESULTS

CircUCK2(2,3) is upregulated in HCC tissues and serves as an independent risk factor for poor recurrence-free survival. The expression of circUCK2(2,3) is independent on its host gene, UCK2, but is regulated by its upstream promoter and flanking inverted complementary sequences. Functionally, circUCK2(2,3) enhances HCC proliferation, migration, and invasion, both in vitro and in vivo. Mechanistically, by sponging miR-149-5p, circUCK2(2,3) increases CNIH4 levels, which in turn amplifies TGFα secretion, resulting in the activation of EGFR and downstream pAKT and pERK signaling pathways. Moreover, circUCK2(2,3) overexpression sensitizes HCC cells to EGFR inhibitors, and increases the synergistic cytotoxicity of combined lenvatinib and EGFR inhibitor treatment.

CONCLUSIONS

CircUCK2(2,3) regulates a novel oncogenic pathway, miR-149-5p-CNIH4-TGFα-EGFR, in HCC, presenting a viable therapeutic target and biomarker for the precision treatment of HCC.

Noncanonical role of Golgi-associated macrophage TAZ in chronic inflammation and tumorigenesis

Until now, Hippo pathway-mediated nucleocytoplasmic translocation has been considered the primary mechanism by which yes-associated protein (YAP) and transcriptional co-activator with PDZ-binding motif (TAZ) transcriptional coactivators regulate cell proliferation and differentiation via transcriptional enhanced associate domain (TEAD)-mediated target gene expression. In this study, however, we found that TAZ, but not YAP, is associated with the Golgi apparatus in macrophages activated via Toll-like receptor ligands during the resolution phase of inflammation. Golgi-associated TAZ enhanced vesicle trafficking and secretion of proinflammatory cytokines in M1 macrophage independent of the Hippo pathway. Depletion of TAZ in tumor-associated macrophages promoted tumor growth by suppressing the recruitment of tumor-infiltrating lymphocytes. Moreover, in a diet-induced metabolic dysfunction-associated steatohepatitis model, macrophage-specific deletion of TAZ ameliorated liver inflammation and hepatic fibrosis. Thus, targeted therapies being developed against YAP/TAZ-TEAD are ineffective in macrophages. Together, our results introduce Golgi-associated TAZ as a potential molecular target for therapeutic intervention to treat tumor progression and chronic inflammatory diseases.

Computational screening and molecular dynamics of natural compounds targeting the SH2 domain of STAT3: a multitarget approach using network pharmacology

SH2 (Src Homology 2) domains play a crucial role in phosphotyrosine-mediated signaling and have emerged as promising drug targets, particularly in cancer therapy. STAT3 (Signal Transducer and Activator of Transcription 3), which contains an SH2 domain, plays a pivotal role in cancer progression and immune evasion because it facilitates the dimerization of STAT3, which is essential for their activation and subsequent nuclear translocation. SH2 domain-mediated STAT3 inhibition disrupts this binding, reduces phosphorylation of STAT3, and impairs dimerization. This study employed an in silico approach to screen potential natural compounds that could target the SH2 domain of STAT3 and inhibit its function. The phytomolecules (182455) were retrieved from the ZINC 15 database and were docked using various modes like HTVS, SP, and XP. The phytomolecules exhibiting higher binding affinity were selected. MM-GBSA was performed to determine binding free energy, and the QikProp tool was utilized to assess the pharmacokinetic properties of potential hit compounds, narrowing down the list of candidates. Molecular dynamics simulations, thermal MM-GBSA, and WaterMap analysis were performed on compounds that exhibited favorable binding affinities and pharmacokinetic characteristics. Based on docking scores and binding interactions, ZINC255200449, ZINC299817570, ZINC31167114, and ZINC67910988 were identified as potential STAT3 inhibitors. ZINC67910988 demonstrated superior stability in molecular dynamics simulation and WaterMap analysis. Furthermore, DFT was performed to determine energetic and electronic properties, and HOMO and LUMO sites were predicted for electronic structure calculation. Additionally, network pharmacology was performed to map the compounds' interactions within biological networks, highlighting their multitarget potential. Compound-target networks elucidate the relationships between compounds and multiple targets, along with their associated pathways and help to minimize off-target effects. The identified lead compound showed strong potential as a STAT3 inhibitor, warranting further validation through in vitro and in vivo studies.

Diosmin induces mitochondrial-mediated apoptosis and anti-inflammatory effects in Hep-2 cells: an integrated in vitro and in silico analysis

The present study aims to explore the anticancer efficacy of Diosmin by inducing mitochondrial-mediated apoptosis in human epidermoid carcinoma cells (Hep-2). This is done by cell line assays and studying crucial inflammatory and apoptotic signaling molecules. The cytotoxicity property of Diosmin was evaluated by MTT (3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide) assay. Marker expression study was done by western blotting for studying apoptotic markers like Bax, Bcl-2, p53, Bak, and Bcl-xl, proinflammatory cytokine (TNF-α), interleukins (IL-1, IL-6, IL-8), and signal transduction (STAT-3). The docking study confirms the affinity of Diosmin with apoptotic and important markers. Through the MTT assay, a dose-dependent cytotoxic effect of Diosmin was unveiled, with an IC50 value of effective inhibition of cell proliferation. Diosmin treatment resulted in noteworthy downregulation of Bcl-xl, Bak, Bcl-2, IL-1, 6, 8, TNF-α, and STAT-3 while upregulating the p53 and Bax expression levels, highlighting its inhibitory role in inducing apoptosis. Docking studies further exposed robust binding affinities between Diosmin and target apoptotic proteins, suggesting its efficacy in disrupting cellular functions and inflammatory signaling pathways in Hep-2 cells. The cytotoxic effects on Hep-2 cells and suggested activation of Bax, p53, and inhibition of Bcl-xl, Bak, Bcl-2, IL-1, 6, 8, TNF-α, as well as STAT-3 lead to the activation of mitochondrial-mediated apoptosis in Diosmin-treated Hep-2 cells. Further, its anti-inflammatory properties locate Diosmin as a conclusive compound for further studies for effective oral and other related squamous carcinoma treatments.

Pathobiont-induced suppressive immune imprints thwart T cell vaccine responses

Pathobionts have evolved many strategies to coexist with the host, but how immune evasion mechanisms contribute to the difficulty of developing vaccines against pathobionts is unclear. Meanwhile, Staphylococcus aureus (SA) has resisted human vaccine development to date. Here we show that prior SA exposure induces non-protective CD4+ T cell imprints, leading to the blunting of protective IsdB vaccine responses. Mechanistically, these SA-experienced CD4+ T cells express IL-10, which is further amplified by vaccination and impedes vaccine protection by binding with IL-10Rα on CD4+ T cell and inhibit IL-17A production. IL-10 also mediates cross-suppression of IsdB and sdrE multi-antigen vaccine. By contrast, the inefficiency of SA IsdB, IsdA and MntC vaccines can be overcome by co-treatment with adjuvants that promote IL-17A and IFN-γ responses. We thus propose that IL-10 secreting, SA-experienced CD4+ T cell imprints represent a staphylococcal immune escaping mechanism that needs to be taken into consideration for future vaccine development.

Cell-specific regulation of insulin action and hepatic fibrosis by CEACAM1

The incidence of metabolic dysfunction-associated steatotic liver disease (MASLD) has reached an epidemic rise worldwide. The disease is a constellation of a broad range of metabolic and histopathologic abnormalities. It begins with hepatic steatosis and progresses to metabolic dysfunction-associated steatohepatitis (MASH), including hepatic fibrosis, apoptosis, and cell injury. Despite ample research effort, the pathogenesis of the disease has not been fully delineated. Whereas insulin resistance is implicated in the early stages of the disease, its role in hepatic fibrosis remains controversial. We have focused our studies on the role of carcinoembryonic antigen-related cell adhesion molecule 1 (CEACAM1) in hepatocytes and endothelial cells in the metabolic and histopathological dysregulation in MASH. Patients with MASH exhibit lower hepatic CEACAM1 with a progressive decline in hepatocytes and endothelial cells as the fibrosis stage advances. In mice, conditional deletion of CEACAM1 in hepatocytes impairs insulin clearance to cause hyperinsulinemia-driven insulin resistance with steatohepatitis and hepatic fibrosis even when mice are fed a regular chow diet. In contrast, its conditional deletion in endothelial cells causes inflammation-driven hepatic fibrosis without adversely affecting metabolism (mice remain insulin-sensitive and do not develop hepatic steatosis). Thus, this review provides in vivo evidence that supports or discards the role of insulin resistance in liver injury and hepatic fibrosis.

Engineered bio-functional material-based nerve guide conduits for optic nerve regeneration: a view from the cellular perspective, challenges and the future outlook

Nerve injuries can be tantamount to severe impairment, standard treatment such as the use of autograft or surgery comes with complications and confers a shortened relief. The mechanism relevant to the regeneration of the optic nerve seems yet to be fully uncovered. The prevailing rate of vision loss as a result of direct or indirect insult on the optic nerve is alarming. Currently, the use of nerve guide conduits (NGC) to some extent has proven reliable especially in rodents and among the peripheral nervous system, a promising ground for regeneration and functional recovery, however in the optic nerve, this NGC function seems quite unfamous. The insufficient NGC application and the unabridged regeneration of the optic nerve could be a result of the limited information on cellular and molecular activities. This review seeks to tackle two major factors (i) the cellular and molecular activity involved in traumatic optic neuropathy and (ii) the NGC application for the optic nerve regeneration. The understanding of cellular and molecular concepts encompassed, ocular inflammation, extrinsic signaling and intrinsic signaling for axon growth, mobile zinc role, Ca2+ factor associated with the optic nerve, alternative therapies from nanotechnology based on the molecular information and finally the nanotechnological outlook encompassing applicable biomaterials and the use of NGC for regeneration. The challenges and future outlook regarding optic nerve regenerations are also discussed. Upon the many approaches used, the comprehensive role of the cellular and molecular mechanism may set grounds for the efficient application of the NGC for optic nerve regeneration.

The mechanism of wen jing tang in the treatment of endometriosis: Insights from network pharmacology and experimental validation

Background

Endometriosis (EM) is a hormone-dependent condition marked by progressively severe secondary dysmenorrhea, significantly impacting patients' quality of life and overall health. Wen Jing Tang (WJT), a traditional Chinese medicinal formulation derived from the Synopsis of the Golden Chamber, has proven to be an effective therapeutic agent for EM. However, the precise molecular mechanisms underlying its efficacy remain unclear.

Objective

This study aims to elucidate the underlying mechanisms of WJT in the treatment of EM by integrating network pharmacology analysis with experimental validation.

Methods

The chemical constituents and target sites of WJT were obtained from the TCMSP database, while EM-related target genes were sourced from OMIM, TTD, GeneCards, and the DrugBank databases. A "herbs-components-targets" network was constructed using Cytoscape 3.9.1. The intersecting target genes of WJT and EM were then uploaded to the STRING database for protein-protein interaction (PPI) analysis. Subsequently, the common target genes were subjected to GO and KEGG enrichment analysis via the DAVID database. Molecular docking were employed to analyze the binding affinities between the top five core components and their respective targets. Additionally, ELISA were used to quantify the serum levels of IL-6, IL-1β, E2, and P in EM model rats. The expression levels of TNF-α, HIF1A, STAT3, and EGFR mRNA and proteins in ectopic endometrial tissue were assessed using q-PCR and Western blotting.

Results

A total of 250 chemical components and 553 targets were identified in WJT, while 3491 EM-related targets were screened from multiple databases. Among these, 187 common targets between WJT and EM were found, with quercetin, kaempferol, and beta-sitosterol emerging as the core chemical components, and AKT1, IL6, TNF, and IL1B identified as the key targets. These core components demonstrated strong binding affinities to the targets. GO and KEGG enrichment analyses revealed that the shared targets were primarily involved in the HIF1 signaling pathway. Furthermore, compared to the control group, the EM model rats exhibited an increased ectopic endometrial area, disordered glandular and stromal cells, and notable inflammatory infiltration. Serum levels of IL-6, IL-1β, E2, and P were significantly elevated (P < 0.01), and the expression of TNF-α, HIF1A, STAT3, and EGFR in the ectopic endometrium was markedly increased (P < 0.01). Following WJT intervention, the ectopic endometrial area in model rats was reduced, the morphology and structure of the endometrial cells showed improvement, and serum levels of IL-6, IL-1β, E2, and P were significantly decreased (P < 0.05). WJT also inhibited the expression of HIF1 pathway-related proteins TNF-α, HIF1A, STAT3, and EGFR (P < 0.05).

Conclusion

The mechanism by which WJT prevents and treats EM may involve the reduction of inflammation through the inhibition of the HIF1 signaling pathway.

Matrine regulates autophagy in ileal epithelial cells in a porcine circovirus type 2-infected murine model

Introduction

Porcine circovirus type 2 (PCV2) is an important pathogen that causes diarrhea in nursery and fattening pigs, resulting in huge economic losses for commercial pig farms. Protective efficacy of vaccines is compromised by mutations in pathogens. There is an urgent need to articulate the mechanism by which PCV2 destroys the host's intestinal mucosal barrier and to find effective therapeutic drugs. Increasing attention has been paid to the natural antiviral compounds extracted from traditional Chinese medicines. In the present study, we investigated the role of Matrine in mitigating PCV2-induced intestinal damage and enhancing autophagy as a potential therapeutic strategy in mice.

Methods

A total of 40 female, specific-pathogen-free-grade Kunming mice were randomly divided into four groups with 10 mice in each group: control, PCV2 infection, Matrine treatment (40 mg/kg Matrine), and Ribavirin treatment (40 mg/kg Ribavirin). Except for the control group, all mice were injected intraperitoneally with 0.5 mL 105.4 50% tissue culture infectious dose (TCID50)/mL PCV2.

Results

While attenuating PCV2-induced downregulation of ZO-1 and occludin and restoring intestinal barrier function in a PCV2 Kunming mouse model, treatment with Matrine (40 mg/kg) attenuated ultrastructural damage and improved intestinal morphology. Mechanistically, Matrine reversed PCV2-induced autophagosome accumulation by inhibiting signal transducer and activator of transcription 3 (STAT3) phosphorylation and upregulating Beclin1 protein expression, thus resisting viral hijacking of enterocyte autophagy.

Discussion

Our findings demonstrate that Matrine may be a novel, potential antiviral agent against PCV2 by activating intestine cellular autophagy, which provides a new strategy for host-directed drug discovery.

Glutamine and serum starvation alters the ATP production, oxidative stress, and abundance of mitochondrial RNAs in extracellular vesicles produced by cancer cells

Induction of autophagy represents an effective survival strategy for nutrient-deprived or stressed cancer cells. Autophagy contributes to the modulation of communication within the tumor microenvironment. Here, we conducted a study of the metabolic and signaling implications associated with autophagy induced by glutamine (Gln) and serum starvation and PI3K/mTOR inhibitor and autophagy inducer NVP-BEZ235 (BEZ) in the head and neck squamous cell carcinoma (HNSCC) cell line FaDu. We compared the effect of these different types of autophagy induction on ATP production, lipid peroxidation, mitophagy, RNA cargo of extracellular vesicles (EVs), and EVs-associated cytokine secretome of cancer cells. Both BEZ and starvation resulted in a decline in ATP production. Simultaneously, Gln starvation enhanced oxidative damage of cancer cells by lipid peroxidation. In starved cells, there was a discernible fragmentation of the mitochondrial network coupled with an increase in the presence of tumor susceptibility gene 101 (TSG101) on the mitochondrial membrane, indicative of the sorting of mitochondrial cargo into EVs. Consequently, the abundance of mitochondrial RNAs (mtRNAs) in EVs released by FaDu cells was enhanced. Notably, mtRNAs were also detectable in EVs isolated from the serum of both HNSCC patients and healthy controls. Starvation and BEZ reduced the production of EVs by cancer cells, yet the characteristic molecular profile of these EVs remained unchanged. We also found that alterations in the release of inflammatory cytokines constitute a principal response to autophagy induction. Importantly, the specific mechanism driving autophagy induction significantly influenced the composition of the EVs-associated cytokine secretome.

Distinct clinical profiles and patient outcomes in aCML and CNL

The classification of atypical chronic myeloid leukemia (aCML) and chronic neutrophilic leukemia (CNL) as a single disease entity remains a topic of debate. To elucidate the characteristics of both entities, this retrospective cohort study was conducted, encompassing 36 cases of aCML and 18 cases of CNL. We discovered that aCML and CNL presented distinct blood counts, genetics, molecular profiles and outcomes. Specifically, hemoglobin levels (P < 0.001) and platelet counts (P < 0.001) were significantly lower in aCML cases than in CNL cases, with no significant difference in mean white blood cells (P = 0.637). The proportion of abnormal karyotypes was higher in aCML cases compared with CNL cases (P = 0.010). Notably, we found that aCML and CNL showed distinct gene expression profiles by transcriptome sequencing technology. The median follow-up duration for the entire cohort was 8 months (rang 0.4 to 36.6 months), and the median overall survival (OS) was significantly shorter in aCML cases (7.3 months, 95%CI 5.4 to 20.5 months) than in CNL cases (median OS not reached). The one-year OS rate for aCML patients was 31.0% (9/29), compared to 92.9% (13/14) for CNL patients. In conclusion, our study supports the notion that aCML and CNL are indeed distinct disease entities characterized by unique hematological features and clinical outcomes.

Advanced glycation end products (AGEs) impair the intestinal epithelial barrier via STAT3 activation mediated by macrophages

Advanced glycation end products (AGEs) are a spectrum of complex compounds widely found in processed foods and frequently consumed by humans. AGEs are implicated in impairing the intestinal barrier, but the underlying mechanisms remain unclear. This study investigated the effects of three types of AGEs on gene expression of tight junctions (TJs) in colorectal epithelial HT-29 cells, and observed minimal alterations in TJs expression. Given the important role of subepithelial macrophages in regulating the intestinal barrier, we explored whether AGEs affect the intestinal barrier via the involvement of macrophages. Notably, a significant downregulation of TJs expression was observed when supernatants from AGEs-treated RAW264.7 macrophage cells were transferred to HT-29 cells. Further investigations indicated that AGEs increased IL-6 levels in RAW264.7 cells, subsequently triggering STAT3 activation and suppressing TJs expression in HT-29 cells. The role of STAT3 activation was confirmed by observing enhanced TJs expression in HT-29 cells following pretreatment with an inhibitor of STAT3 activation prior to the transfer of the conditioned medium. These findings demonstrated that AGEs impaired the intestinal barrier via macrophage-mediated STAT3 activation, shedding light on the mechanisms underlying AGEs-induced intestinal barrier injury and related food safety risks.

Conditional deletion of CEACAM1 in hepatic stellate cells causes their activation

OBJECTIVES

Hepatic CEACAM1 expression declines with advanced hepatic fibrosis stage in patients with metabolic dysfunction-associated steatohepatitis (MASH). Global and hepatocyte-specific deletions of Ceacam1 impair insulin clearance to cause hepatic insulin resistance and steatosis. They also cause hepatic inflammation and fibrosis, a condition characterized by excessive collagen production from activated hepatic stellate cells (HSCs). Given the positive effect of PPARγ on CEACAM1 transcription and on HSCs quiescence, the current studies investigated whether CEACAM1 loss from HSCs causes their activation.

METHODS

We examined whether lentiviral shRNA-mediated CEACAM1 donwregulation (KD-LX2) activates cultured human LX2 stellate cells. We also generated LratCre + Cc1fl/fl mutants with conditional Ceacam1 deletion in HSCs and characterized their MASH phenotype. Media transfer experiments were employed to examine whether media from mutant human and murine HSCs activate their wild-type counterparts.

RESULTS

LratCre + Cc1fl/fl mutants displayed hepatic inflammation and fibrosis but without insulin resistance or hepatic steatosis. Their HSCs, like KD-LX2 cells, underwent myofibroblastic transformation and their media activated wild-type HSCs. This was inhibited by nicotinic acid treatment which blunted the release of IL-6 and fatty acids, both of which activate the epidermal growth factor receptor (EGFR) tyrosine kinase. Gefitinib inhibition of EGFR and its downstream NF-κB/IL-6/STAT3 inflammatory and MAPK-proliferation pathways also blunted HSCs activation in the absence of CEACAM1.

CONCLUSIONS

Loss of CEACAM1 in HSCs provoked their myofibroblastic transformation in the absence of insulin resistance and hepatic steatosis. This response is mediated by autocrine HSCs activation of the EGFR pathway that amplifies inflammation and proliferation.

ESM1 facilitates the EGFR/HER3-triggered epithelial-to-mesenchymal transition and progression of gastric cancer via modulating interplay between Akt and angiopoietin-2 signaling

Gastric cancer (GC) poses global challenges due to its difficult early diagnosis and drug resistance, necessitating the identification of early detection markers and understanding of oncogenic pathways for effective GC therapy. Endothelial cell-specific molecule 1 (ESM1), a secreted glycoprotein, is elevated in various cancers, but its role in GC remains controversial. In our study, ESM1 was elevated in GC tissues, and its concentration was correlated with progression and poorer patient prognosis in independent cohorts. Functionally, ESM1 expression promoted proliferation, anoikis resistance, and motility of GC cells, as well as tumor growth in PDOs and in GC xenograft models. Mechanistically, ESM1 expression triggered the epithelial-to-mesenchymal transition (EMT) of GC cells by enhancing epidermal growth factor receptor (EGFR)/human EGFR 3 (HER3) association and activating the EGFR/HER3-Akt pathway. Additionally, angiopoietin-2 (ANGPT2) was found to be highly correlated with ESM1 and interplayed with Akt to induce the EMT and cancer progression. Use of a signal peptide deletion mutant (ESM1-19del) showed that the secreted form of ESM1 is crucial for its protumorigenic effects by activating the EGFR/HER3-Akt/ANGPT2 pathway to promote the EMT. Patients with high levels of both ESM1 and ANGPT2 had the poorest prognoses. Furthermore, therapeutic peptides successfully inhibited ESM1's induction of the aforementioned signals and motility of GC cells. ESM1's oncogenic role in GC involves activating the EGFR/HER3-Akt/ANGPT2 pathway, presenting a potential therapeutic target for GC.

MMPs as potential molecular targets in epithelial-to-mesenchymal transition driven COPD progression

Chronic obstructive pulmonary disease (COPD) is the third leading cause of mortality globally and the risk of developing lung cancer is six times greater in individuals with COPD who smoke compared to those who do not smoke. Matrix metalloproteinases (MMPs) play a crucial role in the pathophysiology of respiratory diseases by promoting inflammation and tissue degradation. Furthermore, MMPs are involved in key processes like epithelial-to-mesenchymal transition (EMT), metastasis, and invasion in lung cancer. While EMT has traditionally been associated with the progression of lung cancer, recent research highlights its active involvement in individuals with COPD. Current evidence underscores its role in orchestrating airway remodeling, fostering airway fibrosis, and contributing to the potential for malignant transformation in the complex pathophysiology of COPD. The precise regulatory roles of diverse MMPs in steering EMT during COPD progression needs to be elucidated. Additionally, the less-understood aspect involves how these MMPs bi-directionally activate or regulate various EMT-associated signaling cascades during COPD progression. This review article explores recent advancements in understanding MMPs' role in EMT during COPD progression and various pharmacological approaches to target MMPs. It also delves into the limitations of current MMP inhibitors and explores novel, advanced strategies for inhibiting MMPs, potentially offering new avenues for treating respiratory diseases.

TLR4/TNFR1 blockade suppresses STAT1/STAT3 expression and increases SOCS3 expression in modulation of LPS-induced macrophage responses

Due to the urgent need to create appropriate treatment techniques, which are currently unavailable, LPS-induced sepsis has become a serious concern on a global scale. The primary active component in the pathophysiology of inflammatory diseases such as sepsis is the Gram-negative bacterial lipopolysaccharide (LPS). LPS interacts with cell surface TLR4 in macrophages, causing the formation of reactive oxygen species (ROS), TNF-α, IL-1β and oxidative stress. It also significantly activates the MAPKs and NF-κB pathway. Excessive production of pro-inflammatory cytokines is one of the primary characteristic features in the onset and progression of inflammation. Cytokines mainly signal through the JAK/STAT pathway. We hypothesize that blocking of TLR4 along with TNFR1 might be beneficial in suppressing the effects of STAT1/STAT3 due to the stimulation of SOCS3 proteins. Prior to the LPS challenge, the macrophages were treated with antibodies against TLR4 and TNFR1 either individually or in combination. On analysis of the macrophage populations by flowcytometry, it was seen that receptor blockade facilitated the phenotypic shift of the M1 macrophages towards M2 resulting in lowered oxidative stress. Blocking of TLR4/TNFR1 upregulated the SOCS3 and mTOR expressions that enabled the transition of inflammatory M1 macrophages towards the anti-inflammatory M2 phenotype, which might be crucial in curbing the inflammatory responses. Also the reduction in the production of inflammatory cytokines such as IL-6, IL-1β due to the reduction in the activation of the STAT1 and STAT3 molecules was observed in our combination treatment group. All these results indicated that neutralization of both TLR4 and TNFR1 might provide new insights in establishing an alternative therapeutic strategy for LPS-sepsis.

The Regulation of MicroRNA-21 by Interleukin-6 and Its Role in the Development of Fibrosis in Endometriotic Lesions

Endometriosis is one of the most common causes of chronic pelvic pain and infertility that affects 10% of women of reproductive age. It is currently defined as the presence of endometrial epithelial and stromal cells at ectopic sites; however, advances in endometriosis research have some authors believing that endometriosis should be re-defined as "a fibrotic condition in which endometrial stroma and epithelium can be identified". microRNAs (miRNAs) are regulatory molecules that potentially play a role in endometriotic lesion development. There is evidence that suggests that miRNAs, including microRNA-21 (miR-21), participate in fibrotic processes in different organs, including the heart, kidney, liver and lungs. The objective of this study was to understand the role of miR-21 and the mechanisms that can contribute to the development of fibrosis by determining how IL-6 regulates miR-21 expression and how this miRNA regulates the transforming growth factor beta (TGF-β) signaling pathway to promote fibrosis. We investigated the expression of miR-21 in the baboon and mouse model of endometriosis and its correlation with fibrosis. We demonstrated that inflammation and fibrosis are present at a very early stage of endometriosis and that the inflammatory environment in the peritoneal cavity, which includes interleukin 6 (IL-6), can regulate the expression of miR-21 in vitro and in vivo.

Stimuli-Mediated Macrophage Switching, Unraveling the Dynamics at the Nanoplatforms-Macrophage Interface

Macrophages play an essential role in immunotherapy and tissue regeneration owing to their remarkable plasticity and diverse functions. Recent bioengineering developments have focused on using external physical stimuli such as electric and magnetic fields, temperature, and compressive stress, among others, on micro/nanostructures to induce macrophage polarization, thereby increasing their therapeutic potential. However, it is difficult to find a concise review of the interaction between physical stimuli, advanced micro/nanostructures, and macrophage polarization. This review examines the present research on physical stimuli-induced macrophage polarization on micro/nanoplatforms, emphasizing the synergistic role of fabricated structure and stimulation for advanced immunotherapy and tissue regeneration. A concise overview of the research advancements investigating the impact of physical stimuli, including electric fields, magnetic fields, compressive forces, fluid shear stress, photothermal stimuli, and multiple stimulations on the polarization of macrophages within complex engineered structures, is provided. The prospective implications of these strategies in regenerative medicine and immunotherapeutic approaches are highlighted. This review will aid in creating stimuli-responsive platforms for immunomodulation and tissue regeneration.

Impact of Interleukin-6 Activation and Arthritis on Epidermal Growth Factor Receptor (EGFR) Activation in Sensory Neurons and the Spinal Cord

In tumor cells, interleukin-6 (IL-6) signaling can lead to activation of the epidermal growth factor receptor (EGFR), which prolongs Stat3 activation. In the present experiments, we tested the hypothesis that IL-6 signaling activates EGFR signaling in peripheral and spinal nociception and examined whether EGFR localization and activation coincide with pain-related behaviors in arthritis. In vivo in anesthetized rats, spinal application of the EGFR receptor blocker gefitinib reduced the responses of spinal cord neurons to noxious joint stimulation, but only after spinal pretreatment with IL-6 and soluble IL-6 receptor. Using Western blots, we found that IL-6-induced Stat3 activation was reduced by gefitinib in microglial cells of the BV2 cell line, but not in cultured DRG neurons. Immunohistochemistry showed EGFR localization in most DRG neurons from normal rats, but significant downregulation in the acute and most painful arthritis phase. In the spinal cord of mice, EGFR was highly activated mainly in the chronic phase of inflammation, with localization in neurons. These data suggest that spinal IL-6 signaling may activate spinal EGFR signaling. Downregulation of EGFR in DRG neurons in acute arthritis may limit nociception, but pronounced delayed activation of EGFR in the spinal cord may be involved in chronic inflammatory pain.

2'-Hydroxycinnamaldehyde Alleviates Intestinal Inflammation by Attenuating Intestinal Mucosal Barrier Damage Via Directly Inhibiting STAT3

BACKGROUND

The currently available clinical therapeutic drugs for ulcerative colitis (UC) are considered inadequate owing to certain limitations. There have been reports on the anti-inflammatory effects of 2'-hydroxycinnamaldehyde (HCA). However, whether HCA can improve UC is still unclear. Here, we aimed to investigate the pharmacological effects of HCA on UC and its underlying molecular mechanisms.

METHODS

The pharmacological effects of HCA were comprehensively investigated in 2 experimental setups: mice with dextran sulfate sodium (DSS)-induced colitis and lipopolysaccharide (LPS)-treated fetal human colon (FHC) cells. Furthermore, the interaction between HCA and signal transducer and activator of transcription 3 (STAT3) was investigated using molecular docking. The FHC cells with STAT3 knockdown or overexpression and mice with intestinal epithelium-specific STAT3 deletion (STAT3ΔIEC) were used to evaluate whether STAT3 mediated the pharmacological effects of HCA.

RESULTS

2'-Hydroxycinnamaldehyde attenuated dysregulated expression of inflammatory cytokines in a dose-dependent manner while increasing the expression of tight junction proteins, reducing the apoptosis of intestinal epithelial cells, and effectively alleviating inflammation both in vivo and in vitro. 2'-Hydroxycinnamaldehyde bound directly to STAT3 and inhibited its activation. The modulation of STAT3 activation levels due to STAT3 knockdown or overexpression influenced the mitigating effects of HCA on colitis. Further analysis indicated that the remission effect of HCA was not observed in STAT3ΔIEC mice, indicating that STAT3 mediated the anti-inflammatory effects of HCA.

CONCLUSIONS

We present a novel finding that HCA reduces colitis severity by attenuating intestinal mucosal barrier damage via STAT3. This discovery holds promise as a potential new strategy to alleviate UC.

Neurodegenerative Diseases: Unraveling the Heterogeneity of Astrocytes

The astrocyte population, around 50% of human brain cells, plays a crucial role in maintaining the overall health and functionality of the central nervous system (CNS). Astrocytes are vital in orchestrating neuronal development by releasing synaptogenic molecules and eliminating excessive synapses. They also modulate neuronal excitability and contribute to CNS homeostasis, promoting neuronal survival by clearance of neurotransmitters, transporting metabolites, and secreting trophic factors. Astrocytes are highly heterogeneous and respond to CNS injuries and diseases through a process known as reactive astrogliosis, which can contribute to both inflammation and its resolution. Recent evidence has revealed remarkable alterations in astrocyte transcriptomes in response to several diseases, identifying at least two distinct phenotypes called A1 or neurotoxic and A2 or neuroprotective astrocytes. However, due to the vast heterogeneity of these cells, it is limited to classify them into only two phenotypes. This review explores the various physiological and pathophysiological roles, potential markers, and pathways that might be activated in different astrocytic phenotypes. Furthermore, we discuss the astrocyte heterogeneity in the main neurodegenerative diseases and identify potential therapeutic strategies. Understanding the underlying mechanisms in the differentiation and imbalance of the astrocytic population will allow the identification of specific biomarkers and timely therapeutic approaches in various neurodegenerative diseases.

Regulation of Treg cells by cytokine signaling and co-stimulatory molecules

CD4+CD25+Foxp3+ regulatory T cells (Tregs), a vital component of the immune system, are responsible for maintaining immune homeostasis and preventing excessive immune responses. This review explores the signaling pathways of the cytokines that regulate Treg cells, including transforming growth factor beta (TGF-β), interleukin (IL)-2, IL-10, and IL-35, which foster the differentiation and enhance the immunosuppressive capabilities of Tregs. It also examines how, conversely, signals mediated by IL-6 and tumor necrosis factor -alpha (TNF-α) can undermine Treg suppressive functions or even drive their reprogramming into effector T cells. The B7 family comprises indispensable co-stimulators for T cell activation. Among its members, this review focuses on the capacity of CTLA-4 and PD-1 to regulate the differentiation, function, and survival of Tregs. As Tregs play an essential role in maintaining immune homeostasis, their dysfunction contributes to the pathogenesis of autoimmune diseases. This review delves into the potential of employing Treg-based immunotherapy for the treatment of autoimmune diseases, transplant rejection, and cancer. By shedding light on these topics, this article aims to enhance our understanding of the regulation of Tregs by cytokines and their therapeutic potential for various pathological conditions.

Conditional deletion of CEACAM1 causes hepatic stellate cell activation

Objectives

Hepatic CEACAM1 expression declines with advanced hepatic fibrosis stage in patients with MASH. Global and hepatocyte-specific deletions of Ceacam1 impair insulin clearance to cause hepatic insulin resistance and steatosis. They also cause hepatic inflammation and fibrosis, a condition characterized by excessive collagen production from activated hepatic stellate cells (HSCs). Given the positive effect of PPARγ on CEACAM1 transcriptoin and on HSCs quiescence, the current studies investigated whether CEACAM1 loss from HSCs causes their activation.

Methods

We examined whether lentiviral shRNA-mediated CEACAM1 donwregulation (KD-LX2) activates cultured human LX2 stellate cells. We also generated LratCre+Cc1 fl/fl mutants with conditional Ceacam1 deletion in HSCs and characterized their MASH phenotype. Media transfer experiments were employed to examine whether media from mutant human and murine HSCs activate their wild-type counterparts.

Results

LratCre+Cc1 fl/fl mutants displayed hepatic inflammation and fibrosis but without insulin resistance or hepatic steatosis. Their HSCs, like KD-LX2 cells, underwent myofibroblastic transformation and their media activated wild-type HDCs. This was inhibited by nicotinic acid treatment which stemmed the release of IL-6 and fatty acids, both of which activate the epidermal growth factor receptor (EGFR) tyrosine kinase. Gefitinib inhibition of EGFR and its downstream NF-κB/IL-6/STAT3 inflammatory and MAPK-proliferation pathways also blunted HSCs activation in the absence of CEACAM1.

Conclusions

Loss of CEACAM1 in HSCs provoked their myofibroblastic transformation in the absence of insulin resistance and hepatic steatosis. This response is mediated by autocrine HSCs activation of the EGFR pathway that amplifies inflammation and proliferation.

Spatiotemporal Clusters of ERK Activity Coordinate Cytokine-induced Inflammatory Responses in Human Airway Epithelial Cells

RATIONALE

Spatially coordinated ERK signaling events ("SPREADs") transmit radially from a central point to adjacent cells via secreted ligands for EGFR and other receptors. SPREADs maintain homeostasis in non-pulmonary epithelia, but it is unknown whether they play a role in the airway epithelium or are dysregulated in inflammatory disease.

OBJECTIVES

(1) To characterize spatiotemporal ERK activity in response to pro-inflammatory ligands, and (2) to assess pharmacological and metabolic regulation of cytokine-mediated SPREADs.

METHODS

SPREADs were measured by live-cell ERK biosensors in human bronchial epithelial cell lines (HBE1 and 16HBE) and primary human bronchial epithelial (pHBE) cells, in both submerged and biphasic Air-Liquid Interface (ALI) culture conditions (i.e., differentiated cells). Cells were exposed to pro-inflammatory cytokines relevant to asthma and chronic obstructive pulmonary disease (COPD), and to pharmacological treatments (gefitinib, tocilizumab, hydrocortisone) and metabolic modulators (insulin, 2-deoxyglucose) to probe the airway epithelial mechanisms of SPREADs. Phospho-STAT3 immunofluorescence was used to measure localized inflammatory responses to IL-6.

RESULTS

Pro-inflammatory cytokines significantly increased the frequency of SPREADs. Notably, differentiated pHBE cells display increased SPREAD frequency that coincides with airway epithelial barrier breakdown. SPREADs correlate with IL-6 peptide secretion and localized pSTAT3. Hydrocortisone, inhibitors of receptor signaling, and suppression of metabolic function decreased SPREAD occurrence.

CONCLUSIONS

Pro-inflammatory cytokines modulate SPREADs in human airway epithelial cells via both secreted EGFR and IL6R ligands. SPREADs correlate with changes in epithelial barrier permeability, implying a role for spatiotemporal ERK signaling in barrier homeostasis and dysfunction during inflammation. The involvement of SPREADs in airway inflammation suggests a novel signaling mechanism that could be exploited clinically to supplement corticosteroid treatment for asthma and COPD.

NF-κB and JAK/STAT Signaling Pathways as Crucial Regulators of Neuroinflammation and Astrocyte Modulation in Spinal Cord Injury

Spinal cord injury (SCI) leads to significant functional impairments below the level of the injury, and astrocytes play a crucial role in the pathophysiology of SCI. Astrocytes undergo changes and form a glial scar after SCI, which has traditionally been viewed as a barrier to axonal regeneration and functional recovery. Astrocytes activate intracellular signaling pathways, including nuclear factor κB (NF-κB) and Janus kinase-signal transducers and activators of transcription (JAK/STAT), in response to external stimuli. NF-κB and STAT3 are transcription factors that play a pivotal role in initiating gene expression related to astrogliosis. The JAK/STAT signaling pathway is essential for managing secondary damage and facilitating recovery processes post-SCI: inflammation, glial scar formation, and astrocyte survival. NF-κB activation in astrocytes leads to the production of pro-inflammatory factors by astrocytes. NF-κB and STAT3 signaling pathways are interconnected: NF-κB activation in astrocytes leads to the release of interleukin-6 (IL-6), which interacts with the IL-6 receptor and initiates STAT3 activation. By modulating astrocyte responses, these pathways offer promising avenues for enhancing recovery outcomes, illustrating the crucial need for further investigation into their mechanisms and therapeutic applications in SCI treatment.

Sophocarpine alleviates intestinal fibrosis via inhibition of inflammation and fibroblast into myofibroblast transition by targeting the Sirt1/p65 signaling axis

In this study, we used alkaloids from Sophora flavescens to inhibit the SASP, leading to fibroblast-into-myofibroblast transition (FMT) to maintain intestinal mucosal homeostasis in vitro and in vivo. We used western blotting (WB) and immunofluorescence staining (IF) to assess whether five kinds of alkaloids inhibit the major inflammatory pathways and chose the most effective compound (sophocarpine; SPC) to ameliorate colorectal inflammation in a dextran sulfate sodium (DSS)-induced UC mouse model. IF, Immunohistochemistry staining (IHC), WB, disease activity index (DAI), and enzyme-linked immunosorbent assay (ELISA) were conducted to investigate the mechanism of action of this compound. Next, we detected the pharmacological activity of SPC on the senescence-associated secretory phenotypes (SASP) and FMT in interleukin 6 (IL-6)-induced senescence-like fibroblasts and discussed the mucosal protection ability of SPC on a fibroblast-epithelium/organoid coculture system and organ-on-chip system. Taken together, our results provide evidence that SPC alleviates the inflammatory response, improves intestinal fibrosis and maintains intestinal mucosal homeostasis in vivo. Meanwhile, SPC was able to prevent IL-6-induced SASP and FMT in fibroblasts, maintain the expression of TJ proteins, and inhibit inflammation and genomic stability of colonic mucosal epithelial cells by activating SIRT1 in vitro. In conclusion, SPC treatment attenuates intestinal fibrosis by regulating SIRT1/NF-κB p65 signaling, and it might be a promising therapeutic agent for inflammatory bowel disease.

Suppressor of cytokine signaling-3 expression and its regulation in relation to inflammation in Chronic Obstructive Pulmonary Disease

Background

The family of Suppressor of Cytokine Signaling (SOCS) acts as a controller of the duration and intensity of cytokine function by negatively regulating the JAK-STAT signaling pathway. SOCS' role in inflammatory diseases in animal models is well demonstrated. However, its role in the development of human disease is still under investigation. SOCS3 plays an important role in tumor development where its downregulation has been implicated in the pathogenesis of various solid tumors such as triple-negative breast cancer.

Aim

The aim of this work was to study (1) the expression of SOCS3 in smokers' lungs and its relation to the degree of inflammation and (2) SOCS3 regulation by microRNA (miRNA) in alveolar-macrophage (AM)-derived extracellular vesicles (EVs) in bronchoalveolar lavage (BAL).

Methods

Group A: 35 smokers' [19 with COPD (SC) and 16 without COPD (S)] and 9 nonsmokers (NS); SOCS3, TNFα in AM, and CD8+ T cells were quantified by immunohistochemistry, in lung tissue. Group B: additional 9 SC, 11 S, and 5 NS; AM-EVs expressing SOCS3 (CD14+SOCS3+) and SOCS3 suppressors miRNA-19a-3p and 221-3p in EVs were quantified by flow cytometry and PCR, in BAL.

Results

The percentage of SOCS3+ AM was higher in SC [68 (6.6-99)%] and S [48 (8-100)%] than in NS [9.6 (1.9-61)%; p = 0.002; p = 0.03] and correlated with % of TNFα+AM (r = 0.48; p = 0.0009) and CD8+ T cells (r = 0.44; p = 0.0029). In BAL, the CD14+SOCS3+ EVs/μL were increased in SC [33 (21-74)] compared to S [16 (8-37); p = 0.03] and NS [9 (7-21); p = 0.003]. Conversely, miRNA-19a-3p and miRNA-221-3p expression were increased in S when compared to SC [19 (2-53) vs. 3 (0.6-8); p = 0.03 and 3 (0.005-9.6) vs. 0.2 (0.08-0.7); p = 0.05].

Conclusions

The suppressor function of SOCS3 in COPD seems to be overridden by other factors and does not follow the animal-model paradigm. Expression of SOCS3 in BAL macrophage-derived EVs might be useful to assess the degree of inflammation and possible progression of COPD. Downregulation of SOCS3, by miRNA, in smokers without COPD might contribute to the risk of developing cancer in these patients.

TBK1, a prioritized drug repurposing target for amyotrophic lateral sclerosis: evidence from druggable genome Mendelian randomization and pharmacological verification in vitro

BACKGROUND

There is a lack of effective therapeutic strategies for amyotrophic lateral sclerosis (ALS); therefore, drug repurposing might provide a rapid approach to meet the urgent need for treatment.

METHODS

To identify therapeutic targets associated with ALS, we conducted Mendelian randomization (MR) analysis and colocalization analysis using cis-eQTL of druggable gene and ALS GWAS data collections to determine annotated druggable gene targets that exhibited significant associations with ALS. By subsequent repurposing drug discovery coupled with inclusion criteria selection, we identified several drug candidates corresponding to their druggable gene targets that have been genetically validated. The pharmacological assays were then conducted to further assess the efficacy of genetics-supported repurposed drugs for potential ALS therapy in various cellular models.

RESULTS

Through MR analysis, we identified potential ALS druggable genes in the blood, including TBK1 [OR 1.30, 95%CI (1.19, 1.42)], TNFSF12 [OR 1.36, 95%CI (1.19, 1.56)], GPX3 [OR 1.28, 95%CI (1.15, 1.43)], TNFSF13 [OR 0.45, 95%CI (0.32, 0.64)], and CD68 [OR 0.38, 95%CI (0.24, 0.58)]. Additionally, we identified potential ALS druggable genes in the brain, including RESP18 [OR 1.11, 95%CI (1.07, 1.16)], GPX3 [OR 0.57, 95%CI (0.48, 0.68)], GDF9 [OR 0.77, 95%CI (0.67, 0.88)], and PTPRN [OR 0.17, 95%CI (0.08, 0.34)]. Among them, TBK1, TNFSF12, RESP18, and GPX3 were confirmed in further colocalization analysis. We identified five drugs with repurposing opportunities targeting TBK1, TNFSF12, and GPX3, namely fostamatinib (R788), amlexanox (AMX), BIIB-023, RG-7212, and glutathione as potential repurposing drugs. R788 and AMX were prioritized due to their genetic supports, safety profiles, and cost-effectiveness evaluation. Further pharmacological analysis revealed that R788 and AMX mitigated neuroinflammation in ALS cell models characterized by overly active cGAS/STING signaling that was induced by MSA-2 or ALS-related toxic proteins (TDP-43 and SOD1), through the inhibition of TBK1 phosphorylation.

CONCLUSIONS

Our MR analyses provided genetic evidence supporting TBK1, TNFSF12, RESP18, and GPX3 as druggable genes for ALS treatment. Among the drug candidates targeting the above genes with repurposing opportunities, FDA-approved drug-R788 and AMX served as effective TBK1 inhibitors. The subsequent pharmacological studies validated the potential of R788 and AMX for treating specific ALS subtypes through the inhibition of TBK1 phosphorylation.

Anti-Inflammatory Effect of Chamaecyparis obtusa (Siebold & Zucc.) Endl. Leaf Essential Oil

Chamaecyparis obtusa (Siebold & Zucc.) Endl. (C. obtusa) belongs to the Cupressaceae family and is native to East Asian regions. Essential oils extracted from the leaves, bark, branches, and roots of C. obtusa have both aesthetic and medicinal properties and are thus widely used. However, detailed analyses of the active ingredients of C. obtusa extract are lacking. In this study, the sabinene content in the hydro-distillation of C. obtusa leaf essential oil (COD) was analyzed using GC-MS, and the anti-inflammatory effect of COD was compared with that of pure sabinene. Cell viability was evaluated by MTT assay, and nitric oxide (NO) production was measured using Griess reagent. Relative mRNA and protein levels were analyzed using RT-qPCR and western blot, and secreted cytokines were analyzed using a cytokine array kit. The results showed that both COD and sabinene inhibited the expression of inducible nitric oxide synthase (iNOS) and the phosphorylation of c-Jun N-terminal kinase (JNK) and p38 in lipopolysaccharide (LPS)-induced RAW 264.7 cells. COD and sabinene also reduced the production of pro-inflammatory cytokines interleukin (IL)-1β, IL-6, IL-27, IL-1 receptor antagonist (IL-1ra), and granulocyte-macrophage colony-stimulating factor (GM-CSF). The anti-inflammatory mechanisms of COD and sabinene partially overlap, as COD was shown to inhibit MAPKs and the JAK/STAT axis, and sabinene inhibited MAPKs, thereby preventing LPS-induced macrophage activation.

Endogenous blocking of TLR2 along with TNF-α and IL-1β ameliorates the severity of the S. aureus arthritis via modulating STAT3/SOCS3 expressions in tissue resident macrophages

In vivo studies identifying a role of TLR2 in septic arthritis models are lacking. TNF-α played as the most important proinflammatory cytokine, and connected directly to the pathogenesis of bacterial arthritis. IL-1β is another central mediator cytokine in arthritis. It is therefore reasonable to question the role of neutralization of endogenous TNF-α and IL-1β along with TLR2 and associated downstream signaling as crucial mediators in the S. aureus -induced inflammatory arthritis. In reaction to an injury or a pathogen encounter, innate immune cells serve as the initial line of defense. TLR2 mediated entry of S. aureus into macrophage cells initiates an array of inflammatory cascades. After macrophage cell gets activated at the site inflammation, they generate elevated number of cytokines which includes TNF-α, IL-1β. This cytokines signals through STAT1/STAT3 mediated pathways. Thus, aim of this study was to discover how This bone damage could be altered by altering the STAT/STAT3/SOCS3 ratio by blocking TLR2, a particular S. aureus binding site, in conjunction with the use of IL-1 and TNF- antibodies for neutralizing endogenous IL-1β and TNF-α. Additionally, the role of local macrophages in therapy of arthritis was investigated in synovial and Splenic tissue. To comprehend the inflammatory milieu within the system, ROS and other antioxidant enzymes, along with the expression of mTOR in macrophage cells, were also taken into consideration. The detrimental impact of bacterial burden on synovial joints was reduced by simultaneously inhibiting TLR2, TNF-α, and IL-1β. Lowered IFN-γ decreases its sensitivity to STAT1 and lowered IL-6 reduces STAT3 expressions. Whereas, elevated IL-10 enhances SOSC3 expression, which thereby able to limits STAT1/STAT3 inter-conversion. As a result, NF-κB activity was downregulated.

Dynamic IL-6R/STAT3 signaling leads to heterogeneity of metabolic phenotype in pancreatic ductal adenocarcinoma cells

Malignancy is enabled by pro-growth mutations and adequate energy provision. However, global metabolic activation would be self-terminating if it depleted tumor resources. Cancer cells could avoid this by rationing resources, e.g., dynamically switching between "baseline" and "activated" metabolic states. Using single-cell metabolic phenotyping of pancreatic ductal adenocarcinoma cells, we identify MIA-PaCa-2 as having broad heterogeneity of fermentative metabolism. Sorting by a readout of lactic acid permeability separates cells by fermentative and respiratory rates. Contrasting phenotypes persist for 4 days and are unrelated to cell cycling or glycolytic/respiratory gene expression; however, transcriptomics links metabolically active cells with interleukin-6 receptor (IL-6R)-STAT3 signaling. We verify this by IL-6R/STAT3 knockdowns and sorting by IL-6R status. IL-6R/STAT3 activates fermentation and transcription of its inhibitor, SOCS3, resulting in delayed negative feedback that underpins transitions between metabolic states. Among cells manifesting wide metabolic heterogeneity, dynamic IL-6R/STAT3 signaling may allow cell cohorts to take turns in progressing energy-intense processes without depleting shared resources.

Hepatitis C virus modified sE2F442NYT as an antigen in candidate vaccine facilitates human immune cell activation

The rational selection of hepatitis C virus (HCV) vaccine antigen will aid in the prevention of future chronic liver disease burden and associated healthcare costs. We have previously shown that HCV E2 glycoprotein is not highly immunogenic, and the modification of E2 reduced CD81 binding and displayed altered cytokine and protective immune responses in vitro and in a surrogate mouse model. Here, we compared the influence of a parental and a modified sE2F442NYT glycoprotein region from HCV genotype 1a for the activation of peripheral blood mononuclear cell (PBMC)-derived dendritic cells (DCs), CD4+T cells, and B cells. Modified sE2F442NYT, when incubated with DCs, induced a higher number of CD86-positive cells. The sE2F442NYT or parental sE2 encapsulated as mRNA-lipid nanoparticle (sE2F442NYT mRNA-LNP) primed DCs co-cultured with autologous CD4+T cells did not induce CD25 or forkhead box P3 expression. PBMC-derived CD4+T cells treated with sE2F442NYT exhibited enhanced signal transducer and activator of transcription (Stat)1/Stat4 phosphorylation in response to anti-CD3/CD28 stimulation in comparison to parental sE2 treatment and facilitated isotype switching in B cells, leading to the generation of a broader subclass of antibodies. Cells treated with modified sE2F442NYT displayed an increase in activated Stat3 and extracellular signal-regulated kinase (ERK). Likewise, PBMC-derived naïve B cells upon in vitro stimulation with sE2F442NYT induced an increased proliferation, Stat3 and ERK activation, and protein kinase B (Akt) suppression. Thus, the modified sE2F442NYT antigen from HCV facilitates improved DC, CD4+T, and B cell activation compared to parental sE2 to better induce a robust protective immune response, supporting its selection as an HCV candidate vaccine antigen for preclinical and clinical HCV vaccine trials.IMPORTANCEThe nature of an enhanced immune response induced by sE2F442NYT will help in the selection of a broad cross-protective antigen from hepatitis C virus genotypes, and the inclusion of relatively conserved sE1 with sE2F442NYT may further strengthen the efficacy of the candidate vaccine in evaluating it for human use.

Jingfang granule alleviates Pseudomonas aeruginosa-induced acute lung inflammation through suppression of STAT3/IL-17/NF-κB pathway based on network pharmacology analysis and experimental validation

ETHNOPHARMACOLOGICAL RELEVANCE

Pseudomonas aeruginosa is an opportunistic bacterial pathogen which is the second leading cause of hospital-acquired pneumonia. Jingfang granule (JFG) is an herbal formula of Traditional Chinese medicine (TCM) widely used in treatment of acute respiratory tract infections in China. However, the molecular mechanisms of JFG in treatment of P. aeruginosa-induced acute pneumonia are not clear.

AIM OF STUDY

This study aimed to investigate the mechanisms underlying the effects of JFG on P. aeruginosa-induced acute inflammation using a mouse model of bacterial acute pneumonia.

MATERIALS AND METHODS

The chemical components and targets of JFG were retrieved from Traditional Chinese Medicine Systems Pharmacology (TCMSP) database, and the P. aeruginosa pneumonia-related targets were obtained from the disease databases, including Online Mendelian Inheritance in Man (OMIM), GeneCards and DisGeNet. The protein-protein interaction (PPI) network was constructed using STRING database. Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway enrichment analysis were performed using the Database for Annotation, Visualization and Integrated Discovery (DAVID). Molecular docking was performed using AutoDockTools 1.5.6. Further in vivo experiments employed a mouse model of P. aeruginosa acute pneumonia to verify the target proteins and signaling pathways affected by JFG, which were predicted by the network pharmacology analysis.

RESULTS

A total of 218 active components and 257 targets of JFG were retrieved from TCMSP database. Moreover, 99 intersectant targets were obtained between the 257 JFG targets and 694 disease targets. Among the intersectant targets, STAT3, IL-6, AKT1, TNF, MAPK1, MAPK3 and EGFR were identified to be the key therapeutic targets through PPI network analysis, and STAT3 was in the center of the network, which is a key regulator of IL-17 expression. KEGG pathway enrichment analysis suggested that IL-17 signaling pathway was one of the crucial inflammatory pathways affected by JFG in treatment of P. aeruginosa pneumonia. Furthermore, the in vivo experiments demonstrated that the JFG-treated mice displayed reduced proinflammatory cytokine production (IL-17, IL-1β, IL-6 and TNF), diminished neutrophil infiltration and decreased mortality, compared with the non-drug-treated mice during P. aeruginosa lung infection. Moreover, the expression or phosphorylation levels of the key regulators in STAT3/IL-17/NF-κB axis including STAT3, ERK1/2 (MAPK3/1), AKT, NF-κB p65 and RORγt were significantly reduced in the lung tissues of the JFG-treated mice.

CONCLUSION

JFG was effective in treatment of P. aeruginosa acute lung infection, which reduced inflammatory responses through suppressing STAT3/IL-17/NF-κB pathway.

Regulatory mechanisms underlying interleukin-6 expression in murine brown adipocytes

Three types of adipocytes, white, brown, and beige, regulate the systemic energy balance through the storage and expenditure of chemical energy. In addition, adipocytes produce various bioactive molecules known as adipokines. In contrast to white adipocyte-derived molecules, less information is available on the adipokines produced by brown adipocytes (batokine). This study explored the regulatory expression of interleukin (IL)-6 in cell culture studies. Norepinephrine or a nonselective β-adrenergic receptor agonist increased the expression of IL-6 in primary brown adipocytes and HB2 brown adipocytes. Treatment with forskolin (Fsk), an activator of the cAMP-dependent protein kinase (PKA) pathway (downstream signaling of the β-adrenergic receptor), efficiently stimulated IL-6 expression in brown adipocytes and myotubes. Phosphorylated CREB and phosphorylated p38 MAP kinase levels were increased in Fsk-treated brown adipocytes within 5 min. In contrast, a long-term (∼60 min and ∼4 h) treatment with Fsk was required for increase in STAT3 phosphorylation and C/EBPβ expression, respectively. The PKA, p38 MAP kinase, STAT3, and C/EBPβ pathways are required for the maximal IL-6 expression induced by Fsk, which were verified by use of various inhibitors of these signal pathways. Vitamin C enhanced Fsk-induced IL-6 expression through the extracellular signal-regulated kinase activity. The present study provides basic information on the regulatory expression of IL-6 in activated brown adipocytes.

Inhibiting JAK1, not NF-κB, reverses the effect of pro-inflammatory cytokines on engineered human ligament function

The role of inflammation in chronic tendon/ligament injury is hotly debated. There is less debate about inflammation following acute injury. To better understand the effect of acute inflammation, in this study we developed a multi-cytokine model of inflammatory tendinitis. The combined treatment with TNF-α, IL-1β, and IL-6, at dosages well below what are routinely used in vitro, decreased the mechanical properties and collagen content of engineered human ligaments. Treatment with this cytokine mixture resulted in an increase in phospho-NF-κB and MMP-1, did not affect procollagen production, and decreased STAT3 phosphorylation relative to controls. Using this more physiologically relevant model of acute inflammation, we inhibited NF-κB or JAK1 signaling in an attempt to reverse the negative effects of the cytokine mixture. Surprisingly, NF-κB inhibition led to an even greater decrease in mechanical function and collagen content. By contrast, inhibiting JAK1 led to an increase in mechanical properties, collagen content and thermal stability concomitant with a decrease in MMP-1. Our results suggest that inhibition of JAK1, not NF-κB, reverses the negative effects of pro-inflammatory cytokines on collagen content and mechanics in engineered human ligaments.

Host Genetic Impact on Infectious Diseases among Different Ethnic Groups

Infectious diseases such as malaria, tuberculosis (TB), human immunodeficiency virus (HIV), and the coronavirus disease of 2019 (COVID-19) are problematic globally, with high prevalence particularly in Africa, attributing to most of the death rates. There have been immense efforts toward developing effective preventative and therapeutic strategies for these pathogens globally, however, some remain uncured. Disease susceptibility and progression for malaria, TB, HIV, and COVID-19 vary among individuals and are attributed to precautionary measures, environment, host, and pathogen genetics. While studying individuals with similar attributes, it is suggested that host genetics contributes to most of an individual's susceptibility to disease. Several host genes are identified to associate with these pathogens. Interestingly, many of these genes and polymorphisms are common across diseases. This paper analyzes genes and genetic variations within host genes associated with HIV, TB, malaria, and COVID-19 among different ethnic groups. The differences in host-pathogen interaction among these groups, particularly of Caucasian and African descent, and which gene polymorphisms are prevalent in an African population that possesses protection or risk to disease are reviewed. The information in this review could potentially help develop personalized treatment that could effectively combat the high disease burden in Africa.

Cytokine storm and translating IL-6 biology into effective treatments for COVID-19

As of May 3, 2023, the Coronavirus disease 2019 (COVID-19) pandemic has resulted in more than 760 million confirmed cases and over 6.9 million deaths. Several patients have developed pneumonia, which can deteriorate into acute respiratory distress syndrome. The primary etiology may be attributed to cytokine storm, which is triggered by the excessive release of proinflammatory cytokines and subsequently leads to immune dysregulation. Considering that high levels of interleukin-6 (IL-6) have been detected in several highly pathogenic coronavirus-infected diseases, such as severe acute respiratory syndrome in 2002, the Middle East respiratory syndrome in 2012, and COVID-19, the IL-6 pathway has emerged as a key in the pathogenesis of this hyperinflammatory state. Thus, we review the history of cytokine storm and the process of targeting IL-6 signaling to elucidate the pivotal role played by tocilizumab in combating COVID-19.

Arthrofibrosis After Total Knee Arthroplasty: A Critical Analysis Review

» Arthrofibrosis after total knee arthroplasty (TKA) is the new formation of excessive scar tissue that results in limited ROM, pain, and functional deficits.» The diagnosis of arthrofibrosis is based on the patient's history, clinical examination, absence of alternative diagnoses from diagnostic testing, and operative findings. Imaging is helpful in ruling out specific causes of stiffness after TKA. A biopsy is not indicated, and no biomarkers of arthrofibrosis exist.» Arthrofibrosis pathophysiology is multifactorial and related to aberrant activation and proliferation of myofibroblasts that primarily deposit type I collagen in response to a proinflammatory environment. Transforming growth factor-beta signaling is the best established pathway involved in arthrofibrosis after TKA.» Management includes both nonoperative and operative modalities. Physical therapy is most used while revision arthroplasty is typically reserved as a last resort. Additional investigation into specific pathophysiologic mechanisms can better inform targeted therapeutics.

The critical role of interleukin-6 in protection against neurotropic flavivirus infection

West Nile virus (WNV) and Japanese encephalitis virus (JEV) are emerging mosquito-borne flaviviruses causing encephalitis globally. No specific drug or therapy exists to treat flavivirus-induced neurological diseases. The lack of specific therapeutics underscores an urgent need to determine the function of important host factors involved in flavivirus replication and disease progression. Interleukin-6 (IL-6) upregulation has been observed during viral infections in both mice and humans, implying that it may influence the disease outcome significantly. Herein, we investigated the function of IL-6 in the pathogenesis of neurotropic flavivirus infections. First, we examined the role of IL-6 in flavivirus-infected human neuroblastoma cells, SK-N-SH, and found that IL-6 neutralization increased the WNV or JEV replication and inhibited the expression of key cytokines. We further evaluated the role of IL-6 by infecting primary mouse cells derived from IL-6 knockout (IL-6-/-) mice and wild-type (WT) mice with WNV or JEV. The results exhibited increased virus yields in the cells lacking the IL-6 gene. Next, our in vivo approach revealed that IL-6-/- mice had significantly higher morbidity and mortality after subcutaneous infection with the pathogenic WNV NY99 or JEV Nakayama strain compared to WT mice. The non-pathogenic WNV Eg101 strain did not cause mortality in WT mice but resulted in 60% mortality in IL-6-/- mice, indicating that IL-6 is required for the survival of mice after the peripheral inoculation of WNV or JEV. We also observed significantly higher viremia and brain viral load in IL-6-/- mice than in WT mice. Subsequently, we explored innate immune responses in WT and IL-6-/- mice after WNV NY99 infection. Our data demonstrated that the IL-6-/- mice had reduced levels of key cytokines in the serum during early infection but elevated levels of proinflammatory cytokines in the brain later, along with suppressed anti-inflammatory cytokines. In addition, mRNA expression of IFN-α and IFN-β was significantly lower in the infected IL-6-/- mice. In conclusion, these data suggest that the lack of IL-6 exacerbates WNV or JEV infection in vitro and in vivo by causing an increase in virus replication and dysregulating host immune response.