Myeloid Src-family kinases are critical for neutrophil-mediated autoinflammation in gout and motheaten models

Study on the effect and mechanism of ZeXie decoction in treating MSU-induced acute gouty arthritis model through PI3K-AKT-mTOR signaling pathway

BACKGROUND

The incidence of acute gouty arthritis (AGA) is annually increasing, significantly detrimenting the quality of life for patients. ZeXie decoction (ZXT), composed of Atractylodes macrocephala Koidz and Alisma rhizome (Sam.), a timeless formula detailed in "Synopsis of the Golden Chamber" of Chinese medical sage Zhong-Jing Zhang, has shown promising clinical application in treating AGA. Alisol B, a principal component of ZXT, remains however, elusive in its mechanism of action against AGA. This study aimed to delve into the anti-inflammatory effects of Alisol B, a key component within ZXT, and to clarify its mechanism of action in the treatment of AGA.

MATERIALS AND METHODS

We adopted a network pharmacology approach to pinpoint the core targets and pathways involved in ZXT and Alisol B's treatment of AGA patients. Molecular docking was conducted using Autodock software to investigate potential interactions between Alisol B and its target proteins. An in vitro inflammation model was subsequently established. The impact of Alisol B on the expression of inflammatory factors in BMDMs treated with MSU was evaluated using RT-qPCR, supplemented by comparison with the PI3K agonist 740 Y-P (740YPDGFR) treated BMDMs. Subsequently, the expression of EGFR, PIK3CA, PIK3CB, and JAK2 - key players in the PI3K/AKT/mTOR signaling pathway - was assessed via RT-qPCR and Western blotting. Finally, the effect of MSU treatment and Alisol B's treatment on macrophage polarization was determined by flow cytometry.

RESULTS

Findings from network pharmacology and molecular docking suggest that Alisol B may modulate the PI3K-AKT-mTOR signaling pathway to treat AGA. In vitro experiments revealed that Alisol B inhibited the expression of inflammatory vesicles and pro-inflammatory factors by suppressing MSU-induced activation of the PI3K/AKT/mTOR signaling pathway. Additionally, Alisol B improved the cellular inflammatory environment, fostering the production of M2 cells, which could potentially repair cells within the inflammatory environment.

CONCLUSION

Our research unveils that Alisol B curtails the production of inflammatory vesicles and pro-inflammatory cytokines while enhancing the production of anti-inflammatory factors by targeting the PI3K-AKT-mTOR signaling pathway in BMDMs. This may elucidate the pivotal mechanism of Alisol B in the treatment of AGA.

Disruption of survivin protein expression by treatment with YM155 accelerates the resolution of neutrophilic inflammation

BACKGROUND AND PURPOSE

Prolonged survival of neutrophils is essential for determining the progression and severity of inflammatory and immune-mediated disorders, including gouty arthritis. Survivin, an anti-apoptotic molecule, has been described as a regulator of cell survival. This study aims to examine the effects of YM155 treatment, a survivin selective suppressant, in maintaining neutrophil survival in vitro and in vivo experimental settings of neutrophilic inflammation.

EXPERIMENTAL APPROACH

BALB/c mice were injected with monosodium urate (MSU) crystals and treated with YM155 (intra-articularly) at the peak of inflammatory response. Leukocyte recruitment, apoptosis neutrophil and efferocytosis were determined by knee joint wash cell morphology counting and flow cytometry. Resolution interval (Ri) was quantified by neutrophil infiltration, monitoring the amplitude and duration of the inflammation. Cytokine production was measured by ELISA. Mechanical hypernociception was assessed using an electronic von Frey aesthesiometer. Efferocytosis was evaluated in zymosan-induced neutrophilic peritonitis. Survivin and cleaved caspase-3 expression was determined in human neutrophils by flow cytometry.

KEY RESULTS

Survivin was expressed in neutrophils during MSU-induced gout, and the treatment with YM155 reduced survivin expression and shortened Ri from ∼8 h observed in vehicle-treated mice to ∼5.5 h, effect accompanied by increased neutrophil apoptosis and efferocytosis, both crucial for the inflammation resolution. Reduced IL-1β and CXCL1 levels were also observed in periarticular tissue. YM155 reduced histopathological score and hypernociceptive response. In human neutrophils, lipopolysaccharide (LPS) increased survivin expression, whereas survivin inhibition with YM155 induced neutrophil apoptosis, with activation of caspase-3.

CONCLUSIONS AND IMPLICATIONS

Survivin may be a promising therapeutic target to control neutrophilic inflammation.

Myriscagayanone C, a new compound from the fruit of myristica cagayanensis, inhibits fMLP-induced respiratory bursts by specifically preventing Akt translocation in human neutrophils

Neutrophils that are overactivated can cause inflammatory diseases. Neutrophils possess various surface receptors, including G-protein-coupled chemoattractant receptors, which assist in recognizing pathogen attacks and the inflammatory environment. Therefore, targeting G-protein-coupled chemoattractant receptors and their downstream molecules is important for preventing abnormal neutrophil activation. This study examines the effects and underlying mechanism of myriscagayanone C, a new compound obtained from the fruit of myristica cagayanensis, on neutrophil respiratory burst induced by fMLP. The immunoblotting assay was conducted to assess the mechanisms by which myriscagayanone C inhibits fMLP-induced respiratory burst by disrupting the translocation of Akt to the cellular membrane. Briefly, myriscagayanone C suppressed the production of superoxide anions induced by fMLP on human neutrophils in a concentration-dependent manner (IC50: 4.73 ± 0.68 μM). Myriscagayanone C blocked fMLP-induced Akt translocation to the cell membrane, inhibiting AktT308 and AktS473 phosphorylation by PDK1Y373/376 and mTORS2481, respectively. Myriscagayanone C inhibited fMLP-induced p47phox phosphorylation and translocation. Myriscagayanone C did not inhibit the activity of PI3K, the amount of phosphatidylinositol (3, 4, 5)-trisphosphate, or the translocation of phosphorylated-PDK1Y373/376 and -mTORS2481 to the membrane. Myriscagayanone C did not inhibit fMLP-induced PKC, Src, ERK1/2, p38 phosphorylation, and intracellular calcium mobilization. Myriscagayanone C did not inhibit the chemotaxis and CD11b expression induced by fMLP. Myriscagayanone C did not inhibit PMA-induced superoxide anion production and neutrophil extracellular trap formation. According to this data, myriscagayanone C inhibits fMLP-induced neutrophil superoxide anion production by interrupting the translocation of Akt to the plasma membrane, which affects the NADPH oxidase activity by preventing p47phox phosphorylation and translocation.

Neutrophil diversity and function in health and disease

Neutrophils, the most abundant type of granulocyte, are widely recognized as one of the pivotal contributors to the acute inflammatory response. Initially, neutrophils were considered the mobile infantry of the innate immune system, tasked with the immediate response to invading pathogens. However, recent studies have demonstrated that neutrophils are versatile cells, capable of regulating various biological processes and impacting both human health and disease. Cytokines and other active mediators regulate the functional activity of neutrophils by activating multiple receptors on these cells, thereby initiating downstream signal transduction pathways. Dysfunctions in neutrophils and disruptions in neutrophil homeostasis have been implicated in the pathogenesis of numerous diseases, including cancer and inflammatory disorders, often due to aberrant intracellular signaling. This review provides a comprehensive synthesis of neutrophil biological functions, integrating recent advancements in this field. Moreover, it examines the biological roles of receptors on neutrophils and downstream signaling pathways involved in the regulation of neutrophil activity. The pathophysiology of neutrophils in numerous human diseases and emerging therapeutic approaches targeting them are also elaborated. This review also addresses the current limitations within the field of neutrophil research, highlighting critical gaps in knowledge that warrant further investigation. In summary, this review seeks to establish a comprehensive and multidimensional model of neutrophil regulation, providing new perspectives for potential clinical applications and further research.

Comprehensive analysis of the HCK gene in myeloid neoplasms: Insights into biological functions, prognosis, and response to antineoplastic agents

Myeloid neoplasms result from molecular alterations in hematopoietic stem cells, with acute myeloid leukemia (AML) being one of the most aggressive and with a poor prognosis. Hematopoietic cell kinase (HCK) is a proto-oncogene that encodes a protein-tyrosine kinase of the Scr family, and it is highly expressed in AML. The present study investigated HCK expression in normal hematopoietic cells across myeloid differentiation stages and myeloid neoplasm patients. Within the AML cohort, we explored the impact of HCK expression on clinical outcomes and its correlation with clinical, genetic, and laboratory characteristics. Furthermore, we evaluated the association between HCK expression and the response to antineoplastic agents using ex vivo assay data from AML patients. HCK expression is higher in differentiated subpopulations of myeloid cells. High HCK expression was observed in patients with chronic myelomonocytic leukemia, chronic myeloid leukemia, and AML. In patients with AML, high levels of HCK negatively impacted overall and disease-free survival. High HCK expression was also associated with worse molecular risk groups and white blood cell count; however, it was not an independent prognostic factor. In functional genomic analyses, high HCK expression was associated with several biological and molecular processes relevant to leukemogenesis. HCK expression was also associated with sensitivity and resistance to several drugs currently used in the clinic. In conclusion, our analysis confirmed the differential expression of HCK in myeloid neoplasms and its potential association with unfavorable molecular risks in AML. We also provide new insights into HCK biological functions, prognosis, and response to antineoplastic agents.

Network pharmacology and molecular docking to explore the treatment potential and molecular mechanism of Si-Miao decoction against gouty arthritis

Gouty arthritis (GA) is a common metabolic rheumatological disease. Si-Miao decoction has therapeutic effects on GA. In our study, we investigated the mechanism of Si-Miao decoction against GA using network pharmacology and molecular docking analytical methods. The Traditional Chinese Medicine Systems Pharmacology Database was used as the basis for screening the main targets and agents of the Si-Miao decoction, and the Genecards, OMIM, and Drugbank databases were used to screen GA-related targets. They were analyzed using Venn with the drug targets to obtain the intersection targets. We used Cytoscape 3.9.1 to draw the "Drugs-Compounds-Targets" network and the String database for creative protein-protein interaction networks of target genes and filtered core targets. Gene Ontology and Kyoto Encyclopedia of Genes and Genomes were used to analyze the core targets. Molecular docking was performed using AutoDockTools to predict the binding capacity between nuclear targets and active components in the Si-Miao decoction. A total of 50 chemically active components containing 53 common targets of Si-Miao decoction anti-GA and 53 potential drug target proteins were identified. Core targets, namely, TNF, STAT3, SRC, PPARG, TLR4, PTGS2, MMP9, RELA, TGFB1, and SIRT1, were obtained through PPI network analysis. GO and KEGG analyses showed that the mechanism of anti-GA in Si-Miao decoction may proceed by regulating biological processes such as inflammatory factor levels, cell proliferation, apoptosis, and lipid and glucose metabolism, and modulating the NOD-like receptor signaling pathway, IL-17 signaling pathway, TNF signaling pathway, NF-kappa B signaling pathway, and Toll-like receptor signaling pathway. We further screened the core targets, including PTGS2, MMP9, and PPAGR, as receptor proteins based on their degree value and molecular docking with the main active compounds in Si-Miao decoction, and found that baicalein had high affinity. In conclusion, Si-Miao decoction, through anti-inflammatory, apoptosis-regulating, and anti-oxidative stress action mechanisms in the treatment of GA.

Spatiotemporal Observation of Monosodium Urate Crystals Deposition in Synovial Organoids Using Label-Free Stimulated Raman Scattering

Gout, a common form of arthritis, is characterized by the deposition of monosodium urate (MSU) crystals in joints. MSU deposition in synovial tissues would initiate arthritis flares and recurrence, causing irreversible joint damage. However, the dynamic deposition of MSU crystals in tissues lacks experimental observation. In this study, we used chemical-specific, label-free stimulated Raman scattering (SRS) microscopy to investigate the spatiotemporal deposition and morphological characteristics of MSU crystals in human synovial organoids. Our findings revealed a critical 12-h window for MSU deposition in the lining layer of gouty synovium. Moreover, distinctive inflammatory reactions of the lining and sublining synovial layers in gout using SRS microscopy were further verified by immunofluorescence. Importantly, we identified a crucial proinflammatory role of sublining fibroblast-like synoviocytes, indicating a need for targeted medication treatment on these cells. Our work contributes to the fundamental understanding of MSU-based diseases and offers valuable insights for the future development of targeted gout therapies.