Inflammation Research最新文献

Background: The aberrant expression of α defensin 5 (DEFA5) protein in colonic inflammatory bowel diseases (IBDs) underlies the distinct pathogenesis of Crohn's colitis (CC). It can serve as a biomarker for differentiating CC from Ulcerative colitis (UC), particularly in Indeterminate colitis (IC) cases into UC and CC. We evaluated the specificity of commercially available anti-DEFA5 antibodies, emphasizing the need to further validate their appropriateness for a given application and highlighting the necessity for novel antibodies.

Methods: We established two mice monoclonal DEFA5 antibody clones, 1A8 and 4F5, by immunizing mice with purified recombinant protein. We validated the specificity, sensitivity, and cross-reactivity of these antibodies in recognizing both endogenous and recombinant DEFA5 protein, especially for use in Immunohistochemistry (IHC), Western blot (WB), Immunoprecipitation (IP), and enzyme-linked immunosorbent assay (ELISA).

Results: Clones 1A8 and 4F5 effectively recognized the endogenous DEFA5 in active human colon tissue from patients with diverticulitis (DV), UC, CC, and IC disease samples, as well as in transiently transfected HEK293T cells expressing DEFA5 with minimal non-confounding cross reactivity.

Conclusions: The 1A8 and 4F5 clones are useful for a wide variety of immunoassays, including WB, IHC, IP/WB, and ELISA. Their specificity enhances their potential as valuable tools for research applications in IBD colitis.

Background: One of the etiologic components of degenerative spinal illnesses is intervertebral disc degeneration (IVDD), and the accompanying lower back pain is progressively turning into a significant public health problem. Important pathologic characteristics of IVDD include inflammation and acidic microenvironment, albeit it is unclear how these factors contribute to the disease.

Purpose: To clarify the functions of inflammation and the acidic environment in IVDD, identify the critical connections facilitating glycolytic crosstalk and nucleus pulposus cells (NPCs) pyroptosis, and offer novel approaches to IVDD prevention and therapy.

Methods: By developing keywords search strategy, literature was found and screened using databases such as PUBMED, Google Scholar, Web of Science, China National Knowledge Infrastructure, and others. Hub genes, protein interaction networks, clinical transcriptome data validation, and enrichment analysis were used to further validate relevant biological pathways.

Results: It is clear that disc degeneration is associated with apoptosis or pyroptosis, inflammation, and an acidic environment based on literature review. The process of IVDD is intimately associated with pyroptosis, inflammation, and an acidic environment. The precise mechanism may entail the regulation of key genes such NLRP3, ASIC1a, IL1β, TNF-a, and GSDMD. While the acidic environment exacerbated extracellular matrix degradation and promoted cellular senescence and inflammatory factor expression, it was found to be unfavorable for NPCs survival and proliferation. Moreover, NPCs pyroptosis in an acidic environment, the molecular mechanism behind this phenomenon may be connected to ASIC1a mediated Ca + influx. On the other hand, IVDD can be constantly promoted by the interaction between the degenerating disc's acidic and inflammatory environments through "crosstalk" between anaerobic glycolysis and positive feedback.

Conclusion: In summary, the inflammatory process in NPCs is made worse by the buildup of glucose brought on by metabolic problems, such as anaerobic glycolytic processes, and pyroptosis caused by excessive glucose may be mitigated by inhibiting endoplasmic reticulum stress. A new therapeutic approach for IVDD will involve using ASIC1a as a regulatory target to enhance the inflammatory environment and decrease the incidence of NPCs pyroptosis. Following this, anaerobic glycolysis will be regulated, lactic acid generation will be reduced, and the degenerative vicious loop will be blocked.

Background and aims: Endocan has been scarcely explored in COVID-19, especially regarding its modulation by veno-venous extracorporeal membrane oxygenation (VV-ECMO), hypertension or previous renin-angiotensin-aldosterone system (RAAS) inhibitors treatment. We compared endocan and other endotheliitis markers in hospitalized COVID-19 patients and assessed their modulation by VV-ECMO, hypertension and previous RAAS inhibitors treatment.

Material and methods: Serum endocan, intercellular adhesion molecule-1 (ICAM-1), vascular cell adhesion molecule-1 (VCAM-1) and E-selectin were measured in "severe" (n = 27), "critically ill" (n = 17) and "critically ill on VV-ECMO" (n = 17) COVID-19 patients at admission, days 3-4, 5-8 and weekly thereafter, and in controls (n = 23) at a single time point.

Results: Admission endocan and VCAM-1 were increased in all patients, but "critically ill on VV-ECMO" patients had higher endocan and E-Selectin. Endocan remained elevated throughout hospitalization in all groups. "Severe" and "critically ill" hypertensive patients or previously treated with RAAS inhibitors had higher endocan and/or VCAM-1, but in VV-ECMO patients the raised endocan values seemed unrelated with these factors. Among all COVID-19 hypertensive patients, those with previous RAAS inhibitors treatment had higher endocan.

Conclusions: In our study, endocan stands out as the best marker of endotheliitis in hospitalized COVID-19 patients, being upregulated by VV-ECMO support, hypertension and previous RAAS inhibitor treatment.

Background: Sepsis-associated encephalopathy (SAE) often results from neuroinflammation. Recent studies have shown that brain platelet-derived growth factor receptor β (PDGFRβ) cells, including pericytes, may act as early sensors of infection by secreting monocyte chemoattractant protein-1 (MCP-1), which transmits inflammatory signals to the central nervous system. The erythroblast transformation-specific (ETS) transcription factor Friend leukemia virus integration 1 (Fli-1) plays a critical role in inflammation by regulating the expression of key cytokines, including MCP-1. However, the role of pericyte Fli-1 in neuroinflammation during sepsis remains largely unknown.

Methods: WT and pericyte-specific Fli-1 knockout mice were subjected to endotoxemia through LPS injection or sepsis via cecal ligation and puncture (CLP). In vitro, Fli-1 was knocked down using small interfering RNA in cultured mouse brain pericytes, followed by LPS stimulation.

Results: Elevated Fli-1 levels were observed in isolated brain pericytes 2 h after LPS administration, in brain tissues 4 h after CLP, and in cultured mouse brain pericytes 2 h after LPS stimulation in vitro. In endotoxemic mice, pericyte-specific Fli-1 knockout reduced expression of MCP-1 and IL-6 in brain tissue 2 h after LPS injection. At 24 h post-LPS administration, protein levels of MCP-1 and IL-6, and microglia activation were suppressed in pericyte-Fli-1 knockout mice. Additionally, Fli-1 deficiency in pericytes significantly reduced MCP-1 and IL-6 mRNA levels in the brain tissue 4 h after CLP. Moreover, in cultured brain pericytes, Fli-1 knockdown markedly decreased MCP-1 and IL-6 levels after LPS stimulation. Notably, LPS stimulation increased Fli-1 levels via TLR4-Myd88 signaling, which subsequently led to elevated production of MCP-1 in brain pericytes.

Conclusions: Fli-1 in pericytes may serve as a crucial mediator of neuroinflammation during sepsis by directly regulating pivotal cytokines such as MCP-1 and IL-6. Therefore, Fli-1 has the potential to serve as a therapeutic target in SAE and other neuroinflammatory disorders.

Background: Hypertrophic scar (HS) is a severe skin fibrosis. Transplanting stem cells carrying anti-fibrotic cytokine genes, like interferon-gamma (IFN-γ), is a novel therapeutic strategy. Human amniotic epithelial cells (hAECs) are ideal seed cells and gene vectors. Microencapsulation creates a favorable environment for transplanted cells. This study investigates the effect of alginate-polylysine-alginate (APA)-microencapsulated hAECs modified with IFN-γ on HS fibrosis.

Materials and methods: hAECs were isolated from human placentas and characterized. The full-length IFN-γ gene was cloned into the pcDNA3.1 vector to create the recombinant plasmid IFN-γ-pcDNA3.1. This plasmid was then transfected into hAECs, resulting in the generation of IFN-γ-modified hAECs (IFN-γ-hAECs). Subsequently, these IFN-γ-hAECs were microencapsulated with APA to produce APA-IFN-γ-hAECs. In vitro, the release of IFN-γ, as well as the cellular and metabolic activities, growth, proliferation, migration, apoptosis, and trans-differentiation were assessed using HS-derived fibroblasts. In vivo, the weight loss of HS xenografts, collagen fiber arrangement, tissue oxidative stress, and inflammatory response were evaluated using a nude mouse model that had been transplanted with human HS tissues.

Results: In vitro, APA-IFN-γ-hAECs exhibited significantly sustained and enhanced IFN-γ release, increased cellular vitality, and inhibited fibroblast growth, proliferation, migration, and trans-differentiation into myofibroblasts. APA-IFN-γ-hAECs also remarkably downregulated extracellular matrix (ECM) components and promoted apoptosis. In vivo, they significantly accelerated the weight reduction of HS xenografts, improved collagen fiber arrangement, and mitigated oxidative stress and inflammation.

Conclusions: This study suggests that APA-microencapsulated IFN-γ-hAECs may have potential in alleviating HS fibrosis, offering a new direction for exploring effective clinical HS management strategies.

Background: Sclerostin (SOST) is traditionally regarded as an osteocyte-derived secreted glycoprotein that regulates bone mineralization. Recent studies reported that SOST is also released from non-skeletal sources, especially during inflammation. However, the cellular source and regulatory mechanisms governing SOST generation in inflammation remain unclear. This study investigated whether macrophages produce SOST in response to inflammatory stimuli and determined associated regulatory pathways.

Methods: The effect of lipopolysaccharide (LPS)-induced inflammation in SOST generation and its underlying regulatory mechanism was examined on mouse macrophage RAW 264.7 by western blot and immunofluorescent staining. Transfection with miR-92a-3p mimic and inhibitor were used to validate its role in SOST production. The role of NF-κB and TLR4 were studied using pharmacological inhibitors BAY 11-7085 and TAK242, respectively. The involvement of NF-κB and TLR4 in LPS-induced SOST production was further validated through nuclear NF-κB p65 immunoprecipitation and TLR4 small interfering RNA (siRNA) experiments, respectively.GW4869 and manumycin A (extracellular vesicles (EV) biogenesis inhibitors) were used to examine the associated of SOST and EV. Finally, SOST expression and characteristics of the isolated EV were assessed by Western blot and nanoparticle tracking analysis (NTA).

Results: LPS significantly induced SOST protein expression and secretion in RAW 264.7. MiR-92a-3p was upregulated by LPS stimulation in macrophages. Transfection of miR-92a-3p mimic increased SOST generation in RAW 264.7. Inhibition of TLR4 and NF-κB signalling pathways using pharmacological inhibitors significantly suppressed LPS-induced SOST in RAW 264.7. Similarly, TLR4 siRNA effectively suppressed LPS-induced SOST level. However, the LPS-induced upregulation of miR-92a-3p was only regulated by TLR4, but not by NF-κB. NF-κB was found to directly bind to the mouse sost promoter, thereby activating sost transcription. Additionally, SOST secretion was found predominantly associated with EV from LPS-stimulated cells, and inhibition of EV biogenesis suppressed SOST production in RAW 264.7 cells.

Conclusions: In conclusion, our study showed, for the first time, that LPS induced SOST generation and secretion via TLR4/miR-92a-3p/PTEN/NF-κB singling pathway in murine macrophage RAW 264.7 cells. Moreover, we showed that SOST is secreted from the RAW 264.7 cells in the form of extracellular vesicle. This study identified macrophage as a novel source of SOST, highlighting its potential role in inflammatory diseases.

Celastrol is one of the main active ingredients extracted from the plant Tripterygium wilfordii Hook F. A growing number of studies have shown that celastrol has various pharmacological effects, including anti-inflammation, anti-rheumatism, treatment of neurodegenerative diseases, and anti-tumor. This article systematically summarized the mechanism and role of celastrol in lipid metabolism and obesity, rheumatoid arthritis (RA), osteoarthritis (OA), gouty arthritis, inflammatory bowel disease, neurodegenerative diseases, and cancer and other diseases (such as diabetes, respiratory-related diseases, atherosclerosis, psoriasis, hearing loss, etc.). The celastrol played roles in inflammation response, cell apoptosis, autophagy, ferroptosis, and lipid metabolism mainly by acting on chondrocytes, macrophages, mitochondria, and endoplasmic reticulum (ER) through NF-κB, STAT, MAPK, TLR, PI3K-AKT-mTOR, and other signal pathways. This review could provide a reference for the clinical application and further development and utilization of celastrol.

Objective: We aimed to understand the potential therapeutic and anti-inflammatory effects of the phosphodiesterase-4 (PDE4) inhibitor roflumilast in models of pulmonary infection caused by betacoronaviruses.

Methods: Mice were infected intranasally with murine hepatitis virus (MHV-3) or severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). Roflumilast was given to MHV-3-infected mice therapeutically at doses of 1 mg/kg or 10 mg/kg, or prophylactically at 10 mg/kg. In SARS-CoV-2-infected mice, roflumilast was given therapeutically at a dose of 10 mg/kg. Lung histopathology, chemokines (CXCL-1 and CCL2), cytokines (IL-1β, IL-6, TNF, IFN-γ, IL-10 and TGFβ), neutrophil immunohistochemical staining (Ly6G⁺ cells), macrophage immunofluorescence staining (F4/80⁺ cells), viral titration plaque assay, real-time PCR virus detection, and blood cell counts were examined.

Results: Therapeutic treatment with roflumilast at 10 mg/kg reduced lung injury in SARS-CoV-2 or MHV-3-infected mice without compromising viral clearance. In MHV-3-infected mice, reduced lung injury was associated with decreased chemokines levels, prevention of neutrophil aggregates and reduced macrophage accumulation in the lung tissue. However, the prophylactic treatment strategy with roflumilast increased lung injury in MHV-3-infected mice.

Conclusion: Our findings indicate that therapeutic treatment with roflumilast reduced lung injury in MHV-3 and SARS-CoV-2 lung infections. Given the protection induced by roflumilast in inflammation, PDE4 targeting could be a promising therapeutic avenue worth exploring following severe viral infections of the lung.

Background: Hyperoxia-induced brain injury is a severe neurological complication that is often accompanied by adverse long-term prognosis. The pathogenesis of hyperoxia-induced brain injury is highly complex, with neuroinflammation playing a crucial role. The activation of the nucleotide-binding oligomerization domain-like receptor protein 3 (NLRP3) inflammasome, which plays a pivotal role in regulating and amplifying the inflammatory response, is the pathological core of hyperoxia-induced brain injury. Additionally, astrocytes actively participate in neuroinflammatory responses. However, there is currently no comprehensive overview summarizing the role of astrocytes in hyperoxia-induced brain injury and the NLRP3 signaling pathways in astrocytes.

Objective: This article aims to provide an overview of studies reported in the literature investigating the pathological role of astrocyte involvement during the inflammatory response in hyperoxia-induced brain injury, the mechanisms of hyperoxia activateing the NLRP3 inflammasome to mediate pyroptosis in astrocytes, and the potential therapeutic effects of drugs targeting the NLRP3 inflammasome to alleviate hyperoxia-induced brain injury.

Method: We searched major databases (including PubMed, Web of Science, and Google Scholar, etc.) for literature encompassing astrocytes, NLRP3 inflammasome, and pyroptosis during hyperoxia-induced brain injury up to Oct 2024. We combined with studies found in the reference lists of the included studies.

Conclusion: In this study, we elucidated the transition of function in astrocytes and activation mechanisms under hyperoxic conditions, and we summarized the potential upstream of the trigger involved in NLRP3 inflammasome activation during hyperoxia-induced brain injury, such as ROS and potassium efflux. Furthermore, we described the signaling pathways of the NLRP3 inflammasome and pyroptosis executed by GSDMD and GSDME in astrocytes under hyperoxic conditions. Finally, we summarized the inhibitors targeting the NLRP3 inflammasome in astrocytes to provide new insights for treating hyperoxia-induced brain injury.

Background: Allergic rhinitis (AR) represents a persistent inflammatory condition affecting the upper respiratory tract, characterized by abnormal initiation of the immunoglobulin E (IgE)-mediated cascade. Follicular helper T (Tfh) cells and regulatory T (Tfr) cells are pivotal in orchestrating the development of IgE production in AR patients. IL-35, an anti-inflammatory cytokine, secreted by various cellular subpopulations.

Objective: To investigate the interplay and underlying mechanisms between interleukin-35 (IL-35) and Tfr/Tfh2 cells in the context of AR.

Methods: Experimental animal models employing BALB/c mice and IL-35-deficient mice underwent sensitization and challenge procedures utilizing ovalbumin (OVA) as the antigen in vivo. IL-35 was administered intranasally prior to OVA challenges. Nasal histopathological examination, PBMC isolation, Tfr/Tfh2 cell staining, Tfr/Tfh2 sorting and culture, and qPCR analysis as well as enzyme-linked immunosorbent assay (ELISA) were conducted for exploring the effect of IL-35 on Tfr/Tfh2 cells.

Results: Administration of IL-35 suppressed OVA-elicited allergic inflammation in murine models. IL-35 treatment led to an elevation in the proportion of peripheral blood Tfr cells and a decrease in Tfh2 cells. IL-35 also downregulated IL-4 and IL-21 protein expression by Tfh2 cells and upregulated IL-10 and transforming growth factor-β (TGF-β) production by Tfr cells. The anti-ICOS treatment abrogated the effect of IL-35 on Tfh2 and Tfr cells.

Conclusion: Our study provided novel insights into the mechanisms of IL-35 action and its promoting effects on Tfh2 and inhibiting effects on Tfr cells by targeting key transcription factors, contributing to the understanding of the pathogenesis and treatment of AR.