Neutrophil extracellular traps mediate the crosstalk between plaque microenvironment and unstable carotid plaque formation.

The development of unstable carotid atherosclerotic plaques is associated with the induction of neutrophil extracellular traps (NETs) via the activation of diverse inflammatory mediators in the circulating bloodstream. However, the underlying mechanisms through which NETs influence the microenvironment of atherosclerotic plaques and contribute to the development of unstable carotid plaques remain largely elusive. The objective of this study was to elucidate the role of myeloid differentiation protein 1 (MD-1, LY86)-induced NETs underlying the crosstalk between unstable plaque formation and the plaque microenvironment. We employed bioinformatics analysis to identify key genes associated with carotid-unstable plaque, followed by comprehensive validation using various experimental approaches on tissue specimens and plasma samples classified based on pathological characteristics. Patients with carotid-unstable plaques exhibited elevated plasma concentrations of MD-1 (LY86), while patients with stable plaques demonstrated comparatively lower levels. Furthermore, soluble MD-1 was found to induce the formation of NETs through activation of Toll-like receptor signaling pathway. The proliferative and immature vascularization effects of NETs on endothelial cells, as well as their inhibitory impact on cell migration, are directly correlated with the concentration of NETs. Additionally, NETs were found to activate the NF-κB signaling pathway, thereby upregulating ICAM1, VCAM1, MMP14, VEGFA, and IL6 expression in both Human umbilical vein endothelial cells (HUVECs) and HAECs. Subsequently, a significant increase in intraplaque neovascularization by NETs results in poor carotid plaque stability, and NETs in turn stimulate macrophages to produce more MD-1, generating a harmful positive feedback loop. Our findings suggest that soluble MD-1 in the bloodstream triggers the production of NETs through activation of the Toll-like receptor signaling pathway and further indicate NETs mediate a crosstalk between the microenvironment of the carotid plaque and the neovascularization of the intraplaque region. Inhibiting NETs formation or MD-1 secretion may represent a promising strategy to effectively suppress the development of unstable carotid plaques.

Circular RNA circ_0074026 indicates unfavorable prognosis for patients with glioma and facilitates oncogenesis of tumor cells by targeting miR-1304 to modulate ERBB4 expression.

Glioma (GM) is a common malignancy all over the world. A novel circular RNA (circRNA), circ_0074026, has been documented to be upregulated in GM tissues than that of normal counterparts, as confirmed by circRNA microarray. However, the biological mechanism of circ_0074026 is still unreported in GM. The expression of circ_0074026 in GM specimens or cells was detected by quantitative real-time polymerase chain reaction. Fisher's exact test was utilized to evaluate the clinical relevance of circ_0074026 in patients with GM. Kaplan-Meier and Cox regression analysis were used to estimate the prognostic value of circ_0074026. Cell counting kit-8 (CCK-8), acridine orange/ethidium bromide double fluorescence staining, flow cytometry, wound healing, and Transwell assays were used to detect the malignant behaviors of GM cells including cell growth, apoptosis, migration, and invasion. CCK-8 and flow cytometric experiments were utilized to evaluate whether circ_0074026 had a side effect on normal human astrocyte cells. The interaction between miR-1304 and circ_0074026 or ERBB4 3'-untranslated region (3'-UTR) was predicted with circular RNA Interactome and TargetScan, respectively, and then confirmed by the dual-luciferase reporter test. The levels of circ_0074026 were both apparently increased in GM samples and cells. The elevated expression of circ_0074026 was linked to patients' tumor size, WHO grade, disease-free survival, and overall survival. The depletion of circ_0074026 can block cell growth, migration, invasion, and impel cell apoptosis in the LN229 cell line. However, ectopically expressed circ_0074026 caused the opposite effect in the U251 cell line. The following dual-luciferase reporter assay demonstrated that miR-1304 interacted with circ_0074026 and ERBB4 3'-UTR. Furthermore, the rescue assay indicated that circ_0074026 modulated ERBB4 to promote tumor progression by regulating miR-1304. Thus, a novel regulatory pathway may provide a new therapeutic target for patients with GM.