Temporal changes of NF-κB signaling pathway genes in bacterial stimulated whole blood- a host mechanism associated with sepsis

Macrophage polarization in sepsis: Emerging role and clinical application prospect

Sepsis is a severe, potentially fatal condition defined by organ dysfunction due to excessive inflammation. Its complex pathogenesis and poor therapeutic outcomes pose significant challenges in treatment. Macrophages, with their high heterogeneity and plasticity, play crucial roles in both the innate and adaptive immune systems. They can polarize into M1-like macrophages, which promote pro-inflammatory responses, or M2-like macrophages, which mediate anti-inflammatory responses, positioning them as critical mediators in the immune response during sepsis.Macrophages are the main regulators of inflammatory responses, and their polarization is also regulated by inflammatory signaling pathways. This review highlights recent advances in the inflammatory signaling pathways involved in sepsis, mechanism of macrophage polarization mediated by inflammation-related signaling pathways in sepsis, and the role of signaling pathway mediated macrophage polarization in organ dysfunction involved in sepsis. We also explore the therapeutic potential of targeting macrophage polarization for immunotherapy, offering new perspectives on macrophage-targeted treatments for sepsis.

Design, Synthesis, and Biological Evaluation of a Novel NIK Inhibitor with Anti-Inflammatory and Hepatoprotective Effects for Sepsis Treatment

NIK plays a crucial role in the noncanonical NF-κB signaling pathway associated with diverse inflammatory and autoimmune diseases. Our study presents compound 54, a novel NIK inhibitor, designed through a structure-based scaffold-hopping approach from the previously identified B022. Compound 54 demonstrates remarkable selectivity and potency against NIK both in vitro and in vivo, effectively suppressing pro-inflammatory cytokines and nitric oxide production. In mouse models, compound 54 protected against LPS-induced systemic sepsis, reducing AST, ALT, and AKP liver injury markers. Additionally, it also attenuates sepsis-induced lung and kidney damage. Mechanistically, compound 54 blocks the noncanonical NF-κB signaling pathway by targeting NIK, preventing p100 to p52 processing. This work reveals a novel class of NIK inhibitors with significant potential for sepsis therapy.

The protective effect of muscimol against systemic inflammatory response in endotoxemic mice is independent of GABAergic and cholinergic receptors

Systemic inflammatory response syndrome plays an important role in the development of sepsis. GABAergic and cholinergic pathways activation are considered important for inflammatory response regulation. Tumor necrosis factor (TNF)-α, interleukin (IL)-1β, IL-12, IL-10, as well as inducible nitric oxide synthase (iNOS)-derived nitric oxide (NO) are important inflammatory mediators involved in the pathogenesis of sepsis. Muscimol, an active compound from the mushroom Amanita muscaria (L.) Lam., is a potent GABA_A agonist, inhibits inflammatory response via activating GABA_A receptor and vagus nerve. However, the effect of muscimol on lipopolysaccharide (LPS)-induced systemic inflammatory response is still unclear. Therefore, we studied the effects of muscimol on systemic inflammatory response and survival rate in endotoxemic mice. Mice endotoxemia was induced by LPS. Muscimol was given to mice or RAW264.7 cells 30 min before LPS (10 mg/kg, i.p., or 10 ng/mL, respectively). Mice received GABAergic and cholinergic receptor antagonists 30 min before muscimol and LPS. Muscimol decreased TNF-α, IL-1β, IL-12, iNOS-derived NO, and increased IL-10 levels and survival rate after LPS treatment. Muscimol significantly decreased nuclear factor kappa B (NF-κB) activity, increased IκB expression, and decreased pIKK expression in LPS-treated RAW264.7 cells. GABAergic and cholinergic antagonists failed to reverse muscimol's protection in LPS-treated mice. In conclusion, muscimol protected against systemic inflammatory response in endotoxemic mice may be partially independent of GABAergic and cholinergic receptors.

MicroRNAs Promote the Progression of Sepsis-Induced Cardiomyopathy and Neurovascular Dysfunction Through Upregulation of NF-kappaB Signaling Pathway-Associated HDAC7/ACTN4

Introduction

The objective of this study was to determine the NF-kappaB pathway, hub genes, and transcription factors (TFs) in monocytes implicated in the progression of neurovascular-related sepsis-induced cardiomyopathy (SIC) as well as potential miRNAs with regulatory functions.

Methods

: Sepsis-induced cardiomyopathy—and heart failure (HF)-related differentially expressed genes (DEGs) between SIC and HF groups were identified separately by differential analysis. In addition, DEGs and differentially expressed miRNAs (DEmiRNAs) in monocytes between sepsis and the HC group were identified. Then, common DEGs in SIC, HF, and monocyte groups were identified by intersection analysis. Based on the functional pathways enriched by these DEGs, genes related to the NF-kB-inducing kinase (NIK)/NF-kappaB signaling pathway were selected for further intersection analysis to obtain hub genes. These common DEGs, together with sepsis-related DEmiRNAs, were used to construct a molecular interplay network and to identify core TFs in the network.

Results

: A total of 153 upregulated genes and 25 downregulated genes were obtained from SIC-, HF-, and monocyte-related DEGs. Functional pathway analysis revealed that the upregulated genes were enriched in NF-κB signaling pathway. A total of eight genes associated with NF-κB signaling pathway were then further identified from the 178 DEGs. In combination with sepsis-related DEmiRNAs, HDAC7/ACTN4 was identified as a key transcriptional regulatory pair in the progression of SIC and in monocyte regulation. hsa-miR-23a-3p, hsa-miR-3175, and hsa-miR-23b-3p can regulate the progression of SIC through the regulation of HDAC7/ACTN4. Finally, gene set enrichment analysis (GSEA) suggested that HDAC7/ACTN4 may be associated with apoptosis in addition to the inflammatory response.

Conclusion

: hsa-miR-23a-3p, hsa-miR-3175, and hsa-miR-23b-3p are involved in SIC progression by regulating NF-κB signaling signaling pathway-related HDAC7/ACTN4 in monocytes and cardiac tissue cells. These mechanisms may contribute to sepsis-induced neurovascular damage.