Colon-Targeted eNAMPT-Specific Peptide Systems for Treatment of DSS-Induced Acute and Chronic Colitis in Mouse

Abstract

Nicotinamide phosphoribosyl transferase (NAMPT) is required to maintain the NAD+ pool, among which extracellular (e) NAMPT is associated with inflammation, mainly mediated by macrophages. However, the role of (e) NAMPT in inflammatory macrophages in ulcerative colitis is insufficiently understood. Here our analyses of single-cell RNA-seq data revealed that the levels of NAMPT and CYBB/NOX2 in macrophages were elevated in patients with colitis and in mouse models of acute and chronic colitis. These findings indicate the clinical significance of NAMPT and CYBB in colitis. Further, we found that eNAMPT directly binds the extracellular domains of CYBB and TLR4 in activated NLRP3 inflammasomes. Moreover, we developed a recombinant 12-residue TK peptide designated colon-targeted (CT)-conjugated multifunctional NAMPT (rCT-NAMPT), comprising CT as the colon-targeting moiety, which harbors the minimal essential residues required for CYBB/TLR4 binding. rCT-NAMPT effectively suppressed the severity of disease in DSS-induced acute and chronic colitis models through targeting the colon and inhibiting the interaction of NAMPT with CYBB or TLR4. Together, our data show that rCT-NAMPT may serve as an effective novel candidate therapeutic for colitis by modulating the NLRP3 inflammasome-mediated immune signaling system.

Extracellular nicotinamide phosphoribosyltransferase: role in disease pathophysiology and as a biomarker

“…The latter findings were recently confirmed by Kim et al. ( 95 ), who showed that the 57–65 aa region of eNAMPT interacts with the leucine-rich repeats (LRR) domain of TLR4. A putative TLR4-binding site in the C-terminal region of eNAMPT (445–457 aa) has also been identified ( 96 ).…”

“…Using site-directed mutagenesis, the authors identified two regions in the N-terminal part of eNAMPT that are involved in TLR4 binding (b1-b2 loop: 41-52 aa; and a1-a2 loop: 68-77 aa). The latter findings were recently confirmed by Kim et al (95), who showed that the 57-65 aa region of eNAMPT interacts with the leucine-rich repeats (LRR) domain of TLR4. A putative TLR4-binding site in the C-terminal region of eNAMPT (445-457 aa) has also been identified (96).…”

Integrative Analysis of Clinical and Bioinformatics Databases to Reveal the Role of Peripheral Innate Immunity in Kawasaki Disease

“…All available data thus provide evidence of neutrophil activation being crucial to KD pathogenesis. Furthermore, it has been observed that IL1B, SOCS3, and IL1RN exhibit high expression levels in other autoimmune diseases that are closely linked to impaired innate immune function [69].…”

Integrative analysis of single-cell RNA-seq and gut microbiome metabarcoding data elucidates macrophage dysfunction in mice with DSS-induced ulcerative colitis

“…Using public single-cell datasets, our previous study identified key driver genes in macrophages associated with IBD in humans and mouse models through Nampt . Notably, we identified and validated that eNAMPT interact with Tlr4 or Cybb /NOX2 and activate NLRP3 inflammasome in IBD tissues 5 . By understanding the relationship between dysbiotic communities and host immune response, we revealed a crucial role for Nlrp3 / Nampt .…”