Unique Toll-Like Receptor 4 Activation by NAMPT/PBEF Induces NFκB Signaling and Inflammatory Lung Injury

Predictive Modeling of ARDS Mortality Integrating Biomarker/Cytokine, Clinical and Metabolomic Data

Acute Respiratory Distress Syndrome (ARDS), characterized by the rapid onset of respiratory failure and mortality rates of ∼40%, remains a significant challenge in critical care medicine. Despite advances in supportive care, accurate prediction of ARDS mortality remains challenging, resulting in delayed delivery of targeted interventions and effective disease management. Traditional critical illness severity scores lack specificity for ARDS, underscoring the need for more precise prognostic tools for ARDS mortality. To address this crucial gap, we employed a multimodal approach to predict ARDS patients utilizing a comprehensive dataset comprised of integrated clinical, metabolomic, and biochemical/cytokine data from ARDS patients (collected within hours of ICU admission) to develop and validate predictive models of ARDS mortality risk. The most robust multimodal data model generated demonstrated superior predictive capability with an area under the curve (AUC) of 0.868 on the test set and 0.959 on the validation set. Notably, this model achieved perfect specificity in identifying non-survivors in the validation cohort, highlighting potential utility in guiding early and targeted interventions in ICU settings. Metabolomic analysis revealed significant alterations in crucial pathways associated with ARDS mortality with tryptophan metabolism, particularly the kynurenine pathway, emerging as the most significantly enriched metabolic route, as well as the NAD+ metabolism/ nicotinamide phosphoribosyltransferase (NAMPT) and glycosaminoglycan biosynthesis pathways. These metabolic derangements were strongly confirmed by lipidomic/metabolomic analysis of lung tissues from a porcine sepsis/ARDS model. Together, these findings demonstrate the promise of integrating multimodal data to improve ARDS prognostication and to provide important insights into the complex metabolic derangements underlying severe ARDS. Identification of metabolic signatures, such as kynurenine and NAD+ metabolism/NAMPT pathways, may serve as a foundation for developing personalized and effective targeted interventions and management strategies for ARDS patients.

Anti-DAMP therapies for acute inflammation

Shock, affecting a third of intensive care patients, remains a highly fatal condition despite advances in critical care, irrespective of its etiology. Cellular injury, central to shock pathophysiology, triggers the release of damage-associated molecular patterns (DAMPs), such as extracellular cold-inducible RNA-binding protein (eCIRP), high-mobility group box 1 (HMGB1), histones 3 and 4, and adenosine triphosphate (ATP). These molecules are confined within cells under normal conditions and perform essential physiological functions. However, upon their extracellular release during cellular injury, they act as alarmins, engaging pattern recognition receptors (PRRs) on immune cells. This interaction triggers a robust inflammatory response, propagating systemic inflammation and exacerbating tissue damage. Excessive DAMP-mediated inflammation is increasingly recognized as a major contributor to morbidity and mortality in a wide range of critical illnesses, including trauma, hemorrhagic shock, sepsis, and organ ischemia/reperfusion (I/R) injury. These pathologies are characterized by uncontrolled inflammatory cascades driven by the deleterious effects of DAMPs, underscoring the urgent need for targeted therapeutic interventions. This review explores the pivotal role of DAMPs in the pathogenesis of acute inflammation and shock, highlighting cutting-edge therapeutic strategies aimed at mitigating their effects. Emerging approaches include monoclonal antibodies, decoy receptors, small molecule inhibitors, and scavengers designed to neutralize or inhibit DAMP activity. The discussion also delves into the potential clinical applications of these interventions, offering insights into how targeting DAMPs could transform the management of shock and improve patient outcomes.

Small Extracellular Vesicle-Derived Nicotinamide Phosphoribosyltransferase (NAMPT) Induces Acyl-Coenzyme A Synthetase SLC27A4-Mediated Glycolysis to Promote Hepatocellular Carcinoma

Tumour-derived small extracellular vesicles (sEV) are critical mediators within the tumour microenvironment (TME) and are known to regulate various metabolic pathways. In metastatic hepatocellular carcinoma (HCC), mass spectrometry protein analysis of HCC-derived sEV (HCC-sEV) identified an upregulation of nicotinamide phosphoribosyltransferase (NAMPT), a key enzyme in maintaining cellular nicotinamide adenine dinucleotide (NAD+) levels. Our study demonstrates that sEV-NAMPT enhances glycolysis, tumorigenesis, and metastasis in HCC. Specifically, sEV-NAMPT activates the NF-κB transcription factor through toll-like receptor 4 (TLR4), leading to elevated SLC27A4 expression. SLC27A4 functions primarily as a long-chain fatty acid transporter and acyl-CoA synthetase. Lipidomic and metabolomic analyses revealed a positive correlation between SLC27A4 and intracellular levels of triacylglycerol (TG) and dihydroxyacetone phosphate (DHAP). Increased TG levels enhance lipolysis via hepatic lipase and facilitate the conversion of glycerol-3-P to DHAP, an intermediate that bridges lipid metabolism and glycolysis. This study uncovers a novel regulatory axis involving sEV-NAMPT and SLC27A4 in glycolysis, independent of traditional fatty acid metabolism pathways. Clinically, targeting sEV-NAMPT with the inhibitor FK866 significantly inhibited tumour growth in various HCC in vivo models, highlighting the potential of sEV-NAMPT as both a biomarker and therapeutic target in HCC.

NEDD4 E3 ligase-catalyzed NAMPT ubiquitination and autophagy activation are essential for pyroptosis-independent NAMPT secretion in human monocytes

NAMPT is an important intracellular metabolic enzyme (iNAMPT) regulating the NAD+ salvage pathway. However, increased cellular stress (infection, inflammation, hypoxia) promotes the secretion of extracellular NAMPT (eNAMPT), a TLR4 ligand and damage-associated molecular pattern protein (DAMP) that directly drives amplification of innate immune-mediated inflammatory, fibrotic, and neoplastic responses to influence disease severity. We sought to examine the mechanisms underlying pyroptotic eNAMPT release from human monocytic THP-1 cells, evoked by Nigericin, and non-pyroptotic eNAMPT secretion elicited by lipopolysaccharide (LPS). Our data indicate eNAMPT secretion/release requires NLRP3 inflammasome activation with substantial attenuation by either NLRP3 inhibition (MCC-950) or targeted genetic deletion of key inflammasome components, including NLRP3, caspase-1, or gasdermin D (GSDMD). Pyroptosis-associated eNAMPT release involved cleavage of the pore-forming GSDMD protein resulting in plasma membrane rupture (PMR) whereas non-pyroptotic LPS-induced eNAMPT secretion involved neither GSDMD cleavage nor PMR, verified utilizing non-cleavable GSDMD mutant constructs. LPS-induced eNAMPT secretion, however, was highly dependent upon NAMPT ubiquitination catalyzed by a complex containing the NEDD4 E3 ligase, Hsp90 (a selective chaperone), and intact GSDMD verified by enzymatic inhibition or silencing of NEDD4, GSDMD, or Hsp90. NAMPT ubiquitination and secretion involves autophagy activation as super-resolution microscopy analyses demonstrate NAMPT co-localization with autophagosome marker LC3B and eNAMPT secretion was significantly reduced by targeted ATG5 and ATG7 inhibition, critical components of the autophagy E3-like complex. These studies provide key insights into eNAMPT secretion that may accelerate the development of therapeutic strategies that address unmet therapeutic needs in inflammatory, fibrotic and neoplastic disorders.

Implication of Immunobiological Function of Melanocytes in Dermatology

Melanocytes are essential for regulating pigmentation and providing photoprotection in human skin. Originating from neural crest cells, these cells migrate to the basal layer of the epidermis and hair follicles during embryogenesis. Melanosomes, the specialized, membrane-bound organelles are essential for melanin synthesis. Beyond their role in pigmentation, melanocytes exhibit complex immune functions, expressing a variety of immune-related markers and receptors, such as pattern recognition receptors (PRRs), major histocompatibility complex class II (MHC-II) molecules, CD40, intercellular adhesion molecule 1 (ICAM-1), and programmed death-ligand 1 (PD-L1). These receptors allow melanocytes to detect environmental signals and engage in the innate immune response. Furthermore, melanocytes release various immunomodulatory substances, including proinflammatory cytokines, chemokines, and damage-associated molecular patterns (DAMPs), contributing to immune regulation. The immune functions of melanocytes are significantly influenced by external factors such as ultraviolet radiation (UVR), the microbiome, and oxidative stress. In different skin diseases, these immune functions may vary. For example, vitiligo, a common hypopigmentary disorder, is primarily driven by an autoimmune response targeting melanocytes, giving rise to depigmentation and the appearance of white patches. In contrast, melanoma, a form of skin cancer that arises from melanocytes, is closely linked to UV exposure. This review highlights the diverse immunobiological functions of melanocytes and their implications in dermatology.

NAD World 3.0: the importance of the NMN transporter and eNAMPT in mammalian aging and longevity control

Over the past five years, systemic NAD+ (nicotinamide adenine dinucleotide) decline has been accepted to be a key driving force of aging in the field of aging research. The original version of the NAD World concept was proposed in 2009, providing an integrated view of the NAD+-centric, systemic regulatory network for mammalian aging and longevity control. The reformulated version of the concept, the NAD World 2.0, was then proposed in 2016, emphasizing the importance of the inter-tissue communications between the hypothalamus and peripheral tissues including adipose tissue and skeletal muscle. There has been significant progress in our understanding of the importance of nicotinamide mononucleotide (NMN), a key NAD+ intermediate, and nicotinamide phosphoribosyltransferase (NAMPT), particularly extracellular NAMPT (eNAMPT). With these exciting developments, the further reformulated version of the concept, the NAD World 3.0, is now proposed, featuring multi-layered feedback loops mediated by NMN and eNAMPT for mammalian aging and longevity control.

Retinoic Acid Regulates Allergic Inflammation via Limiting Mast Cell Activation

BackgroundAllergic diseases have become one of the major public health problems to be addressed in the world today. As a tissue resident cell, mast cells are crucial in the pathogenesis of allergic diseases. Vitamin A is an important fat-soluble vitamin with immunomodulatory functions. Vitamin A deficiency has been shown to be associated with allergic disease states, including asthma; however, no studies have been reported on whether vitamin A deficiency has an effect on the activation of mast cells in allergic reactions. ObjectiveTo explore whether blocking retinoic acid receptors has an effect on mast cell degranulation. Methods Flow cytometry was used to analyze the expression of FCεRIα and CD117 on the cell surface, toluidine blue staining was used to visualize cellular features and morphological changes. ELISA was used to detect histamine release. High-throughput transcriptome sequencing and qRT-PCR were used to detect the expression of relevant signaling pathways and cytokine genes. Western blot was used to detect the expression of relevant signaling pathway proteins. ResultsIn the present study, we found that antagonism of the retinoic acid receptor (RAR) resulted in overactive mast cells and increased their degranulation. Furthermore, inflammatory signaling pathways such as MyD88-IKK-NF-κB and PI3K-Akt-m-TOR were involved in the effect of retinoic acid (RA) on the activation state of mast cells. ConclusionsIn this paper, we demonstrated that blocking RAR can exacerbate its activation state in IgE-mediated mast cells. This study provided new insights into the possibility that vitamin A deficiency exacerbated mast cell activation and thus affectd allergic diseases and their mechanisms.

Extracellular nicotinamide phosphoribosyltransferase (eNAMPT) drives abnormal pericyte-rich vasculature in triple-negative breast cancer

Tumour angiogenesis supports malignant cells with oxygen and nutrients to promote invasion and metastasis. A number of cytokines released in situ participate in the recruitment of endothelial cells and pericytes to trigger the formation of novel blood vessels, which are often abnormal, leaky, and disorganized. Nicotinamide phosphoribosyltransferase is a key intracellular enzyme involved in NAD metabolism and is up regulated in many cancers to meet bioenergetic demands. Yet, the same protein is also secreted extracellularly (eNAMPT), where it acts as a pro-inflammatory cytokine. High plasma eNAMPT levels have been reported in breast cancer patients and correlate with aggressiveness and prognosis. We now report that in a triple-negative breast cancer model, enriching the tumour microenvironment with eNAMPT leads to abundant angiogenesis and increased metastatization. Atypically, the eNAMPT-mediated pro-angiogenic effect is mainly directed to NG2+ pericytes. Indeed, eNAMPT acts as chemoattractant for pericytes and coordinates vessel-like tube formation, in synergism with the classical factor PDGF-BB. Stimulation of pericytes by eNAMPT leads to a pro-inflammatory activation, characterized by the overexpression of key chemokines (CXCL8, CXCL1, CCL2) and VCAM1, via NF-κB signalling. All these effects were ablated by the use of C269, an anti-eNAMPT neutralizing antibody, suggesting that this might represent a novel anti-angiogenic pharmacological approach for triple-negative breast cancer.

Visfatin Enhances RANKL-Induced Osteoclastogenesis In Vitro: Synergistic Interactions and Its Role as a Mediator in Osteoclast Differentiation and Activation

Visfatin, an adipokine secreted by various cell types, plays multifaceted pathophysiological roles in inflammatory conditions, including obesity, which is closely associated with osteoclastogenesis, a key process underlying bone loss and increased osteoporosis (OP) risk. However, the role of visfatin in osteoclastogenesis remains controversial. This study was conducted to investigate the effects of visfatin on receptor activator of nuclear factor kappa-B ligand (RANKL)-induced osteoclast differentiation from precursor cells in vitro. Our results demonstrated that although visfatin exhibited a modest osteoclast-inductive effect relative to that of RANKL, co-stimulation of bone marrow-derived macrophages (BMDMs) with visfatin and RANKL led to significantly enhanced osteoclast differentiation and activation compared to individual stimulation. Neutralization of visfatin activity using blocking antibodies before differentiation markedly suppressed RANKL-induced osteoclastogenesis, as evidenced by a near-complete absence of tartrate-resistant acid phosphatase-positive multinucleated osteoclasts, decreased levels of nuclear factor of activated T cells cytoplasmic 1 and osteoclast-specific proteins, inhibition of nuclear factor-κB and mitogen-activated protein kinase signaling pathways, and a decrease in resorption pit formation. Our findings underscore the critical role of visfatin in RANKL-induced osteoclastogenesis in vitro and highlight the RANKL/visfatin signaling axis as a potential therapeutic target for destructive bone loss-related diseases.

The function of nicotinamide phosphoribosyl transferase (NAMPT) and its role in diseases

Nicotinamide phosphoribosyl transferase (NAMPT) is a rate-limiting enzyme in the mammalian nicotinamide adenine dinucleotide (NAD) salvage pathway, and plays a vital role in the regulation of cell metabolic activity, reprogramming, aging and apoptosis. NAMPT synthesizes nicotinamide mononucleotide (NMN) through enzymatic action, which is a key protein involved in host defense mechanism and plays an important role in metabolic homeostasis and cell survival. NAMPT is involved in NAD metabolism and maintains intracellular NAD levels. Sirtuins (SIRTs) are a family of nicotinamide adenine dinucleotide (NAD)-dependent histone deacetylases (HDACs), the members are capable of sensing cellular NAD+ levels. NAMPT-NAD and SIRT constitute a powerful anti-stress defense system. In this paper, the structure, biological function and correlation with diseases of NAMPT are introduced, aiming to provide new ideas for the targeted therapy of related diseases.

Inhibition of ethanol-induced eNAMPT secretion attenuates liver ferroptosis through BAT-Liver communication

BACKGROUND & AIMS

Extracellular nicotinamide phosphoribosyltransferase (eNAMPT) has long been recognized as an adipokine. However, the exact role of eNAMPT in alcoholic liver disease (ALD) and its relevance to brown adipose tissue (BAT) remain largely unknown. This study aimed to evaluate the impact of eNAMPT on liver function and the underlying mechanisms involved in BAT-Liver communication.

METHODS

Serum eNAMPT levels were detected in the serum of both ALD patients and mice. Chronic and binge ethanol feeding was used to induce alcoholic liver injury in mice. An eNAMPT antibody, a coculture model of brown adipocytes and hepatocytes, and BAT-specific Nampt knockdown mice were used to investigate the role of eNAMPT in ALD.

RESULTS

Serum eNAMPT levels are elevated in ALD patients and are significantly positively correlated with the liver injury index. In ALD mice, neutralizing eNAMPT reduced the elevated levels of circulating eNAMPT induced by ethanol and attenuated liver injury. In vitro experiments revealed that eNAMPT induced hepatocyte ferroptosis through the TLR4-dependent mitochondrial ROS-induced ferritinophagy pathway. Furthermore, ethanol stimulated eNAMPT secretion from brown adipocytes but not from other adipocytes. In the coculture model, ethanol-induced release of eNAMPT from brown adipocytes promoted hepatocyte ferroptosis. In BAT-specific Nampt-knockdown mice, ethanol-induced eNAMPT secretion was significantly reduced, and alcoholic liver injury were attenuated. These effects can be reversed by intraperitoneal injection of eNAMPT.

CONCLUSION

Inhibition of ethanol-induced eNAMPT secretion from BAT attenuates liver injury and ferroptosis. Our study reveals a previously uncharacterized critical role of eNAMPT-mediated BAT-Liver communication in ALD and highlights its potential as a therapeutic target.

NAMPT enhances LOX expression and promotes metastasis in human chondrosarcoma cells by inhibiting miR-26b-5p synthesis

Chondrosarcoma is a malignant bone tumor that emerges from abnormalities in cartilaginous tissue and is related with lung metastases. Nicotinamide phosphoribosyltransferase (NAMPT) is an adipocytokine reported to enhance tumor metastasis. Our results from clinical samples and the Gene Expression Omnibus data set reveal that NAMPT levels are markedly higher in chondrosarcoma patients than in normal individuals. NAMPT stimulation significantly increased lysyl oxidase (LOX) production in chondrosarcoma cells. Additionally, NAMPT increased LOX-dependent cell migration and invasion in chondrosarcoma by suppressing miR-26b-5p generation through the c-Src and Akt signaling pathways. Overexpression of NAMPT promoted chondrosarcoma metastasis to the lung in vivo. Furthermore, knockdown of LOX counteracted NAMPT-facilitated metastasis. Thus, the NAMPT/LOX axis presents a novel target for treating the metastasis of chondrosarcoma.

Inflammatory lung injury is associated with endothelial cell mitochondrial fission and requires the nitration of RhoA and cytoskeletal remodeling

Higher levels of extracellular nicotinamide phosphoribosyltransferase (eNAMPT), a TLR4 agonist, are associated with poor clinical outcomes in sepsis-induced acute lung injury (ALI). Little is known regarding the mechanisms by which eNAMPT is involved in ALI. Our recent work has identified a crucial role for mitochondrial dysfunction in ALI. Thus, this study aimed to determine if eNAMPT-mediated inflammatory injury is associated with the loss of mitochondrial function. Our data show that eNAMPT disrupted mitochondrial bioenergetics. This was associated with cytoskeleton remodeling and the loss of endothelial barrier integrity. These changes were associated with enhanced mitochondrial fission and blocked when Rho-kinase (ROCK) was inhibited. The increases in mitochondrial fission were also associated with the nitration-mediated activation of the small GTPase activator of ROCK, RhoA. Blocking RhoA nitration decreased eNAMPT-mediated mitochondrial fission and endothelial barrier dysfunction. The increase in fission was linked to a RhoA-ROCK mediated increase in Drp1 (dynamin-related protein 1) at serine(S)616. Another TLR4 agonist, lipopolysaccharide (LPS), also increased mitochondrial fission in a Drp1 and RhoA-ROCK-dependent manner. To validate our findings in vivo, we challenged C57BL/6 mice with eNAMPT in the presence and absence of the Drp1 inhibitor, Mdivi-1. Mdivi-1 treatment protected against eNAMPT-induced lung inflammation, edema, and lung injury. These studies demonstrate that mitochondrial fission-dependent disruption of mitochondrial function is essential in TLR4-mediated inflammatory lung injury and identify a key role for RhoA-ROCK signaling. Reducing mitochondrial fission could be a potential therapeutic strategy to improve ARDS outcomes.

Pro- and anti-inflammatory cytokines: the hidden keys to autoimmune gastritis therapy

Autoimmune gastritis (AIG) is an autoimmune disorder characterized by the destruction of gastric parietal cells and atrophy of the oxyntic mucosa which induces intrinsic factor deficiency and hypo-achlorhydria. AIG predominantly affects the antral mucosa with AIG patients experiencing increased inflammation and a predisposition toward the development of gastric adenocarcinoma and type I neuroendocrine tumors. The exact pathogenesis of this autoimmune disorder is incompletely understood although dysregulated immunological mechanisms appear to major contributors. This review of autoimmune gastritis, an unmet medical need, summarizes current knowledge on pro- and anti-inflammatory cytokines and strategies for the discovery of novel biomarkers and potential pharmacological targets.

Inhibition of nicotinamide phosphoribosyltransferase (NAMPT) in cancer: a patent review

INTRODUCTION

Nicotinamide phosphoribosyltransferase (NAMPT) is the rate-limiting enzyme in the biosynthesis of nicotinamide adenine dinucleotide (NAD) from nicotinamide. In addition to its role as essential redox cofactor, NAD also functions as a substrate for NAD-consuming enzymes, regulating multiple cellular processes such as DNA repair and gene expression, fundamental to sustain energetic needs for tumor growth. In this sense, NAMPT over-expression represents a common strategy that several tumor types adopt to sustain NAD production. In addition to its enzymatic role, NAMPT behaves as cytokine-like protein with pro-inflammatory function. Increasing evidence demonstrated that NAMPT inhibition represents a promising anti-cancer strategy to deplete NAD and impair cellular metabolism in cancer conditions.

AREAS COVERED

By using Espacenet, we collected the patents which identified new molecules, compounds, formulations and methods able to inhibit NAMPT from 2007 to date.

EXPERT OPINION

Most of the collected patents focused the attention on the ability of different compounds to inhibit the enzymatic activity of NAMPT, lacking other important aspects related to the extracellular role of NAMPT and the ability of alternative enzymes to counteract NAMPT-mediated NAD depletion. It is necessary to consider also these aspects to promote novel strategies and create novel inhibitors and molecules useful as anti-cancer compounds.

Single-Cell RNA Sequencing Reveals the Spatial Heterogeneity and Functional Alteration of Endothelial Cells in Chronic Hepatitis B Infection

Chronic Hepatitis B virus (CHB) infection is a global health challenge, causing damage ranging from hepatitis to cirrhosis and hepatocellular carcinoma. In our study, single-cell RNA sequencing (scRNA-seq) analysis was performed in livers from mice models with chronic inflammation induced by CHB infection and we found that endothelial cells (ECs) exhibited the largest number of differentially expressed genes (DEGs) among all ten cell types. NF-κB signaling was activated in ECs to induce cell dysfunction and subsequent hepatic inflammation, which might be mediated by the interaction of macrophage-derived and cholangiocyte-derived VISFATIN/Nampt signaling. Moreover, we divided ECs into three subclusters, including periportal ECs (EC_Z1), midzonal ECs (EC_Z2), and pericentral ECs (EC_Z3) according to hepatic zonation. Functional analysis suggested that pericentral ECs and midzonal ECs, instead of periportal ECs, were more vulnerable to HBV infection, as the VISFATIN/Nampt- NF-κB axis was mainly altered in these two subpopulations. Interestingly, pericentral ECs showed increasing communication with macrophages and cholangiocytes via the Nampt-Insr and Nampt-Itga5/Itgb1 axis upon CHB infection, which contribute to angiogenesis and vascular capillarization. Additionally, ECs, especially pericentral ECs, showed a close connection with nature killer (NK) cells and T cells via the Cxcl6-Cxcr6 axis, which is involved in shaping the microenvironment in CHB mice livers. Thus, our study described the heterogeneity and functional alterations of three subclusters in ECs. We revealed the potential role of VISFATIN/Nampt signaling in modulating ECs characteristics and related hepatic inflammation, and EC-derived chemokine Cxcl16 in shaping NK and T cell recruitment, providing key insights into the multifunctionality of ECs in CHB-associated pathologies.

NAMPT-targeting PROTAC and nicotinic acid co-administration elicit safe and robust anti-tumor efficacy in NAPRT-deficient pan-cancers

Nicotinamide phosphoribosyltransferase (NAMPT) catalyzes the biosynthesis of nicotinamide adenine dinucleotide (NAD+), making it a potential target for cancer therapy. Two challenges hinder its translation in the clinic: targeting the extracellular form of NAMPT (eNAMPT) remains insufficient, and side effects are observed in normal tissues. We previously utilized proteolysis-targeting chimera (PROTAC) to develop two compounds capable of simultaneously degrading iNAMPT and eNAMPT. Unfortunately, the pharmacokinetic properties were inadequate, and toxicities similar to those associated with traditional inhibitors arose. We have developed a next-generation PROTAC molecule 632005 to address these challenges, demonstrating exceptional target selectivity and bioavailability, improved in vivo exposure, extended half-life, and reduced clearance rate. When combined with nicotinic acid, 632005 exhibits safety and robust efficacy in treating NAPRT-deficient pan-cancers, including xenograft models with hematologic malignancy and prostate cancer and patient-derived xenograft (PDX) models with liver cancer. Our findings provide clinical references for patient selection and treatment strategies involving NAMPT-targeting PROTACs.

The Intersection of the Pathogenic Processes Underlying Psoriasis and the Comorbid Condition of Obesity

In the past decade, our understanding of psoriasis pathogenesis has made significant steps forward, leading to the development of multiple game-changing therapies. While psoriasis primarily affects the skin, it is increasingly recognized as a systemic disease that can have effects beyond the skin. Obesity is associated with more severe forms of psoriasis and can potentially worsen the systemic inflammation and metabolic dysfunction seen in psoriatic patients. The exact mechanisms underlying the link between these two conditions are not fully understood, but it is believed that chronic inflammation and immune dysregulation play a role. In this review, we examine the existing body of knowledge regarding the intersection of pathogenic processes responsible for psoriasis and obesity. The ability of biological therapies to reduce systemic and obesity-related inflammation in patients with psoriasis will be also discussed.

Development of a cloud-based flow rate tool for eNAMPT biomarker detection

Increased levels of extracellular nicotinamide phosphoribosyltransferase (eNAMPT) are increasingly recognized as a highly useful biomarker of inflammatory disease and disease severity. In preclinical animal studies, a monoclonal antibody that neutralizes eNAMPT has been generated to successfully reduce the extent of inflammatory cascade activation. Thus, the rapid detection of eNAMPT concentration in plasma samples at the point of care (POC) would be of great utility in assessing the benefit of administering an anti-eNAMPT therapeutic. To determine the feasibility of this POC test, we conducted a particle immunoagglutination assay on a paper microfluidic platform and quantified its extent with a flow rate measurement in less than 1 min. A smartphone and cloud-based Google Colab were used to analyze the flow rates automatically. A horizontal flow model and an immunoagglutination binding model were evaluated to optimize the detection time, sample dilution, and particle concentration. This assay successfully detected eNAMPT in both human whole blood and plasma samples (diluted to 10 and 1%), with the limit of detection of 1-20 pg/mL (equivalent to 0.1-0.2 ng/mL in undiluted blood and plasma) and a linear range of 5-40 pg/mL. Furthermore, the smartphone POC assay distinguished clinical samples with low, mid, and high eNAMPT concentrations. Together, these results indicate this POC assay, which utilizes low-cost materials, time-effective methods, and a straightforward immunoassay (without surface immobilization), may reliably allow rapid determination of eNAMPT blood/plasma levels to advantage patient stratification in clinical trials and guide ALT-100 mAb therapeutic decision-making.

Extracellular Nicotinamide Phosphoribosyltransferase Is a Therapeutic Target in Experimental Necrotizing Enterocolitis

Necrotizing enterocolitis (NEC) is the most common gastrointestinal emergency of prematurity. Postulated mechanisms leading to inflammatory necrosis of the ileum and colon include activation of the pathogen recognition receptor Toll-like receptor 4 (TLR4) and decreased levels of transforming growth factor beta (TGFβ). Extracellular nicotinamide phosphoribosyltransferase (eNAMPT), a novel damage-associated molecular pattern (DAMP), is a TLR4 ligand and plays a role in a number of inflammatory disease processes. To test the hypothesis that eNAMPT is involved in NEC, an eNAMPT-neutralizing monoclonal antibody, ALT-100, was used in a well-established animal model of NEC. Preterm Sprague-Dawley pups delivered prematurely from timed-pregnant dams were exposed to hypoxia/hypothermia and randomized to control-foster mother dam-fed rats, injected IP with saline (vehicle) 48 h after delivery; control + mAB-foster dam-fed rats, injected IP with 10 µg of ALT-100 at 48 h post-delivery; NEC-orally gavaged, formula-fed rats injected with saline; and NEC + mAb-formula-fed rats, injected IP with 10 µg of ALT-100 at 48 h. The distal ileum was processed 96 h after C-section delivery for histological, biochemical, molecular, and RNA sequencing studies. Saline-treated NEC pups exhibited markedly increased fecal blood and histologic ileal damage compared to controls (q < 0.0001), and findings significantly reduced in ALT-100 mAb-treated NEC pups (q < 0.01). Real-time PCR in ileal tissues revealed increased NAMPT in NEC pups compared to pups that received the ALT-100 mAb (p < 0.01). Elevated serum levels of tumor necrosis factor alpha (TNFα), interleukin 6 (IL-6), interleukin-8 (IL-8), and NAMPT were observed in NEC pups compared to NEC + mAb pups (p < 0.01). Finally, RNA-Seq confirmed dysregulated TGFβ and TLR4 signaling pathways in NEC pups that were attenuated by ALT-100 mAb treatment. These data strongly support the involvement of eNAMPT in NEC pathobiology and eNAMPT neutralization as a strategy to address the unmet need for NEC therapeutics.

Nicotinamide phosphoribosyltransferase prompts bleomycin-induced pulmonary fibrosis by driving macrophage M2 polarization in mice

Rationale: Idiopathic pulmonary fibrosis (IPF) is an irreversible, fatal interstitial lung disease lacking specific therapeutics. Nicotinamide phosphoribosyltransferase (NAMPT), the rate-limiting enzyme of the nicotinamide adenine dinucleotide (NAD) salvage biosynthesis pathway and a cytokine, has been previously reported as a biomarker for lung diseases; however, the role of NAMPT in pulmonary fibrosis has not been elucidated. Methods: We identified the NAMPT level changes in pulmonary fibrosis by analyzing public RNA-Seq databases, verified in collected clinical samples and mice pulmonary fibrosis model by Western blotting, qRT-PCR, ELISA and Immunohistochemical staining. We investigated the role and mechanism of NAMPT in lung fibrosis by using pharmacological inhibition on NAMPT and Nampt transgenic mice. In vivo macrophage depletion by clodronate liposomes and reinfusion of IL-4-induced M2 bone marrow-derived macrophages (BMDMs) from wild-type mice, combined with in vitro cell experiments, were performed to further validate the mechanism underlying NAMPT involving lung fibrosis. Results: We found that NAMPT increased in the lungs of patients with IPF and mice with bleomycin (BLM)-induced pulmonary fibrosis. NAMPT inhibitor FK866 alleviated BLM-induced pulmonary fibrosis in mice and significantly reduced NAMPT levels in bronchoalveolar lavage fluid (BALF). The lung single-cell RNA sequencing showed that NAMPT expression in monocytes/macrophages of IPF patients was much higher than in other lung cells. Knocking out NAMPT in mouse monocytes/macrophages (Namptfl/fl;Cx3cr1CreER) significantly alleviated BLM-induced pulmonary fibrosis in mice, decreased NAMPT levels in BALF, reduced the infiltration of M2 macrophages in the lungs and improved mice survival. Depleting monocytes/macrophages in Namptfl/fl;Cx3cr1CreER mice by clodronate liposomes and subsequent pulmonary reinfusion of IL-4-induced M2 BMDMs from wild-type mice, reversed the protective effect of monocyte/macrophage NAMPT-deletion on lung fibrosis. In vitro experiments confirmed that the mechanism of NAMPT engaged in pulmonary fibrosis is related to the released NAMPT by macrophages promoting M2 polarization in a non-enzyme-dependent manner by activating the STAT6 signal pathway. Conclusions: NAMPT prompts bleomycin-induced pulmonary fibrosis by driving macrophage M2 polarization in mice. Targeting the NAMPT of monocytes/macrophages is a promising strategy for treating pulmonary fibrosis.

Channeling Nicotinamide Phosphoribosyltransferase (NAMPT) to Address Life and Death

Nicotinamide phosphoribosyltransferase (NAMPT) catalyzes the rate-limiting step in NAD+ biosynthesis via salvage of NAM formed from catabolism of NAD+ by proteins with NADase activity (e.g., PARPs, SIRTs, CD38). Depletion of NAD+ in aging, neurodegeneration, and metabolic disorders is addressed by NAD+ supplementation. Conversely, NAMPT inhibitors have been developed for cancer therapy: many discovered by phenotypic screening for cancer cell death have low nanomolar potency in cellular models. No NAMPT inhibitor is yet FDA-approved. The ability of inhibitors to act as NAMPT substrates may be associated with efficacy and toxicity. Some 3-pyridyl inhibitors become 4-pyridyl activators or "NAD+ boosters". NAMPT positive allosteric modulators (N-PAMs) and boosters may increase enzyme activity by relieving substrate/product inhibition. Binding to a "rear channel" extending from the NAMPT active site is key for inhibitors, boosters, and N-PAMs. A deeper understanding may fulfill the potential of NAMPT ligands to regulate cellular life and death.

Palmatine Attenuated Lipopolysaccharide-Induced Acute Lung Injury by Inhibiting M1 Phenotype Macrophage Polarization via NAMPT/TLR2/CCR1 Signaling

The present work was conducted to research the potential mechanism of palmatine (PAL) on lipopolysaccharide (LPS)-caused acute lung injury (ALI). Network pharmacology and bioinformatic analyses were carried out. Mice were intragastrically treated with PAL and intratracheally stimulated with LPS. LPS-induced RAW264.7 cells were employed for the in vitro model. The MPO activity, W/D ratio, neutrophils, total cell number in BALF, and histopathological alteration were examined. The levels of TNF-α, IL-1β, IL-6, IL-18, IL-4, and IL-10 in serum, BALF, and supernatant were examined by ELISA. The mRNA expressions of iNOS, CD68, Arg1, Ym1, and CD206 and protein expressions of NAMPT, TLR2, CCR1, and NLRP3 inflammasome were detected by PCR, WB, and immunofluorescence. The NAMPT inhibitor FK866, TLR2 inhibitor C29, CCR1 inhibitor BX471, NAMPT-overexpression (OE) plasmid, and TLR2-OE plasmid were used for mechanism research. As a result, PAL relieved the symptoms of ALI. PAL inhibited M1 phenotype indices and promoted M2 phenotype indices in both LPS-induced mice and RAW264.7 cells. PAL also inhibited the expressions of NAMPT, TLR2, CCR1, and NLRP3 inflammasome. The treatments with FK866, NAMPT-OE plasmid, C29, TLR2-OE plasmid, and BX471 proved that PAL exerted its effect via NAMPT/TLR2/CCR1. Molecular docking suggested that PAL might combine with NAMPT. In conclusion, PAL ameliorated LPS-induced ALI by inhibiting M1 phenotype macrophage polarization via NAMPT/TLR2/CCR1 signaling.

Single-cell colocalization analysis using a deep generative model

Analyzing colocalization of single cells with heterogeneous molecular phenotypes is essential for understanding cell-cell interactions, and cellular responses to external stimuli and their biological functions in diseases and tissues. However, existing computational methodologies identified the colocalization patterns between predefined cell populations, which can obscure the molecular signatures arising from intercellular communication. Here, we introduce DeepCOLOR, a computational framework based on a deep generative model that recovers intercellular colocalization networks with single-cell resolution by the integration of single-cell and spatial transcriptomes. Along with colocalized population detection accuracy that is superior to existing methods in simulated dataset, DeepCOLOR identified plausible cell-cell interaction candidates between colocalized single cells and segregated cell populations defined by the colocalization relationships in mouse brain tissues, human squamous cell carcinoma samples, and human lung tissues infected with SARS-CoV-2. DeepCOLOR is applicable to studying cell-cell interactions behind various spatial niches. A record of this paper's transparent peer review process is included in the supplemental information.

A Razor's Edge: Vascular Responses to Acute Inflammatory Lung Injury/Acute Respiratory Distress Syndrome

Historically considered a metabolically inert cellular layer separating the blood from the underlying tissue, the endothelium is now recognized as a highly dynamic, metabolically active tissue that is critical to organ homeostasis. Under homeostatic conditions, lung endothelial cells (ECs) in healthy subjects are quiescent, promoting vasodilation, platelet disaggregation, and anti-inflammatory mechanisms. In contrast, lung ECs are essential contributors to the pathobiology of acute respiratory distress syndrome (ARDS), as the quiescent endothelium is rapidly and radically altered upon exposure to environmental stressors, infectious pathogens, or endogenous danger signals into an effective and formidable regulator of innate and adaptive immunity. These dramatic perturbations, produced in a tsunami of inflammatory cascade activation, result in paracellular gap formation between lung ECs, sustained lung edema, and multi-organ dysfunction that drives ARDS mortality. The astonishing plasticity of the lung endothelium in negotiating this inflammatory environment and efforts to therapeutically target the aberrant ARDS endothelium are examined in further detail in this review.

Interorgan communication networks in the kidney-lung axis

The homeostasis and health of an organism depend on the coordinated interaction of specialized organs, which is regulated by interorgan communication networks of circulating soluble molecules and neuronal connections. Many diseases that seemingly affect one primary organ are really multiorgan diseases, with substantial secondary remote organ complications that underlie a large part of their morbidity and mortality. Acute kidney injury (AKI) frequently occurs in critically ill patients with multiorgan failure and is associated with high mortality, particularly when it occurs together with respiratory failure. Inflammatory lung lesions in patients with kidney failure that could be distinguished from pulmonary oedema due to volume overload were first reported in the 1930s, but have been largely overlooked in clinical settings. A series of studies over the past two decades have elucidated acute and chronic kidney-lung and lung-kidney interorgan communication networks involving various circulating inflammatory cytokines and chemokines, metabolites, uraemic toxins, immune cells and neuro-immune pathways. Further investigations are warranted to understand these clinical entities of high morbidity and mortality, and to develop effective treatments.

TLR4 Ligation by eNAMPT, a Novel DAMP, is Essential to Sulfur Mustard- Induced Inflammatory Lung Injury and Fibrosis

Objective

Human and preclinical studies of sulfur mustard (SM)-induced acute and chronic lung injuries highlight the role of unremitting inflammation. We assessed the utility of targeting the novel DAMP and TLR4 ligand, eNAMPT (extracellular nicotinamide phosphoribosyltransferase), utilizing a humanized mAb (ALT-100) in rat models of SM exposure.

Methods

Acute (SM 4.2 mg/kg, 24 hrs), subacute (SM 0.8 mg/kg, day 7), subacute (SM 2.1 mg/kg, day 14), and chronic (SM 1.2 mg/kg, day 29) SM models were utilized.

Results

Each SM model exhibited significant increases in eNAMPT expression (lung homogenates) and increased levels of phosphorylated NFkB and NOX4. Lung fibrosis (Trichrome staining) was observed in both sub-acute and chronic SM models in conjunction with elevated smooth muscle actin (SMA), TGFβ, and IL-1β expression. SM-exposed rats receiving ALT-100 (1 or 4 mg/kg, weekly) exhibited increased survival, highly significant reductions in histologic/biochemical evidence of lung inflammation and fibrosis (Trichrome staining, decreased pNFkB, SMA, TGFβ, NOX4), decreased airways strictures, and decreased plasma cytokine levels (eNAMPT, IL-6, IL-1β. TNFα).

Conclusion

The highly druggable, eNAMPT/TLR4 signaling pathway is a key contributor to SM-induced ROS production, inflammatory lung injury and fibrosis. The ALT-100 mAb is a potential medical countermeasure to address the unmet need to reduce SM-associated lung pathobiology/mortality.

The Role of Adipokines in the Control of Pituitary Functions

The pituitary gland is a key endocrine gland in all classes of vertebrates, including mammals. The pituitary gland is an important component of hypothalamus-pituitary-target organ hormonal regulatory axes and forms a functional link between the nervous system and the endocrine system. In response to hypothalamic stimuli, the pituitary gland secretes a number of hormones involved in the regulation of metabolism, stress reactions and environmental adaptation, growth and development, as well as reproductive processes and lactation. In turn, hormones secreted by target organs at the lowest levels of the hormonal regulatory axes regulate the functions of the pituitary gland in the process of hormonal feedback. The pituitary also responds to other peripheral signals, including adipose-tissue-derived factors. These substances are a broad group of peptides known as adipocytokines or adipokines that act as endocrine hormones mainly involved in energy homeostasis. Adipokines, including adiponectin, resistin, apelin, chemerin, visfatin, and irisin, are also expressed in the pituitary gland, and they influence the secretory functions of this gland. This review is an overview of the existing knowledge of the relationship between chosen adipose-derived factors and endocrine functions of the pituitary gland, with an emphasis on the pituitary control of reproductive processes.

An eNAMPT-neutralizing mAb reduces post-infarct myocardial fibrosis and left ventricular dysfunction

Myocardial infarction (MI) triggers adverse ventricular remodeling (VR), cardiac fibrosis, and subsequent heart failure. Extracellular nicotinamide phosphoribosyltransferase (eNAMPT) is postulated to play a significant role in VR processing via activation of the TLR4 inflammatory pathway. We hypothesized that an eNAMPT specific monoclonal antibody (mAb) could target and neutralize overexpressed eNAMPT post-MI and attenuate chronic cardiac inflammation and fibrosis. We investigated humanized ALT-100 and ALT-300 mAb with high eNAMPT-neutralizing capacity in an infarct rat model to test our hypothesis. ALT-300 was 99mTc-labeled to generate 99mTc-ALT-300 for imaging myocardial eNAMPT expression at 2 hours, 1 week, and 4 weeks post-IRI. The eNAMPT-neutralizing ALT-100 mAb (0.4 mg/kg) or saline was administered intraperitoneally at 1 hour and 24 hours post-reperfusion and twice a week for 4 weeks. Cardiac function changes were determined by echocardiography at 3 days and 4 weeks post-IRI. 99mTc-ALT-300 uptake was initially localized to the ischemic area at risk (IAR) of the left ventricle (LV) and subsequently extended to adjacent non-ischemic areas 2 hours to 4 weeks post-IRI. Radioactive uptake (%ID/g) of 99mTc-ALT-300 in the IAR increased from 1 week to 4 weeks (0.54 ± 0.16 vs. 0.78 ± 0.13, P < 0.01). Rats receiving ALT-100 mAb exhibited significantly improved myocardial histopathology and cardiac function at 4 weeks, with a significant reduction in the collagen volume fraction (%LV) compared to controls (21.5 ± 6.1% vs. 29.5 ± 9.9%, P < 0.05). Neutralization of the eNAMPT/TLR4 inflammatory cascade is a promising therapeutic strategy for MI by reducing chronic inflammation, fibrosis, and preserving cardiac function.

NAMPT mediates PDGF-induced pulmonary arterial smooth muscle cell proliferation by TLR4/NF-κB/PLK4 signaling pathway

Nicotinamide phosphoribosyltransferase (NAMPT), a pleiotropic protein, promotes the proliferation and migration of pulmonary artery smooth muscle cells (PASMCs), which is associated with the genesis and progression of pulmonary arterial hypertension (PAH). NAMPT is highly increased in PAH patient's plasma and highly relevant to PAH severity. The mRNA and protein levels of NAMPT are elevated in PAH animal models. However, the underlying molecular mechanisms how NAMPT mediated platelet-derived growth factor (PDGF)-induced PASMCs proliferation are still unclear. The present study aimed to address these issues. Primary cultured PASMCs were attained from male Sprague-Dawley (SD) rats. Western blotting, RT-PCR, ELISA, cell transfection, Cell Counting Kit-8 (CCK-8) and EdU incorporation assays were used in the experiments. We showed that PDGF upregulated NAMPT expression through the activation of signal transducers and activators of transcription 5 (STAT5), and elevated extracellular NAMPT further promoted the activation of NF-κB through Toll-like receptor 4 (TLR4), which ultimately upregulated polo-like kinase 4 (PLK4) expression leading to PASMCs proliferation. Knockdown of STAT5, NAMPT or PLK4, and inhibition of TLR4 or NF-κB suppressed PDGF-induced PASMCs proliferation. Our study suggests that NAMPT plays an essential role in PDGF-induced PASMCs proliferation via TLR4/NF-κB/PLK4 pathway, suggesting that targeting NAMPT might be valuable in ameliorating pulmonary arterial hypertension.

Targeting NAD+ metabolism: dual roles in cancer treatment

Nicotinamide adenine dinucleotide (NAD+) is indispensable for various oxidation-reduction reactions in mammalian cells, particularly during energy production. Malignant cells increase the expression levels of NAD+ biosynthesis enzymes for rapid proliferation and biomass production. Furthermore, mounting proof has indicated that NAD-degrading enzymes (NADases) play a role in creating the immunosuppressive tumor microenvironment (TME). Interestingly, both inhibiting NAD+ synthesis and targeting NADase have positive implications for cancer treatment. Here we summarize the detrimental outcomes of increased NAD+ production, the functions of NAD+ metabolic enzymes in creating an immunosuppressive TME, and discuss the progress and clinical translational potential of inhibitors for NAD+ synthesis and therapies targeting NADase.

Visfatin in the porcine pituitary gland: expression and regulation of secretion during the oestrous cycle and early pregnancy

Visfatin is a multifunctional protein which, besides the control of energy homeostasis, seems to be also involved in the regulation of female fertility through the influence on the endocrine hypothalamus-pituitary-gonadal axis, including the pituitary. The aim of this study was to investigate the expression of visfatin mRNA and protein in the anterior (AP) and posterior pituitary lobes of the pig during the oestrous cycle and early pregnancy. In AP, we also examined colocalisation of visfatin with pituitary tropic hormones. Moreover, we aimed to evaluate the in vitro effects of GnRH, FSH, LH, and insulin on visfatin protein concentration and secretion in AP cells during the cycle. The study showed that visfatin is present in all types of porcine pituitary endocrine cells and its expression is reliant on stage of the cycle or pregnancy. GnRH, FSH, LH and insulin stimulated visfatin secretion by AP cells on days 17 to 19 of the cycle, while on days 2 to 3 visfatin release was enhanced only by LH. Summarising, visfatin is locally produced in the pituitary in a way dependent on hormonal milieu typical for reproductive status of pigs. Further research is required to clarify the role of visfatin in the pituitary gland.

Overlapping Science in Radiation and Sulfur Mustard Exposures of Skin and Lung: Consideration of Models, Mechanisms, Organ Systems, and Medical Countermeasures: Overlapping science in radiation and sulfur mustard injuries to lung and skin

PURPOSE

To summarize presentations and discussions from the 2022 trans-agency workshop titled "Overlapping science in radiation and sulfur mustard (SM) exposures of skin and lung: Consideration of models, mechanisms, organ systems, and medical countermeasures."

METHODS

Summary on topics includes: (1) an overview of the radiation and chemical countermeasure development programs and missions; (2) regulatory and industry perspectives for drugs and devices; 3) pathophysiology of skin and lung following radiation or SM exposure; 4) mechanisms of action/targets, biomarkers of injury; and 5) animal models that simulate anticipated clinical responses.

RESULTS

There are striking similarities between injuries caused by radiation and SM exposures. Primary outcomes from both types of exposure include acute injuries, while late complications comprise chronic inflammation, oxidative stress, and vascular dysfunction, which can culminate in fibrosis in both skin and lung organ systems. This workshop brought together academic and industrial researchers, medical practitioners, US Government program officials, and regulators to discuss lung-, and skin- specific animal models and biomarkers, novel pathways of injury and recovery, and paths to licensure for products to address radiation or SM injuries.

CONCLUSIONS

Regular communications between the radiological and chemical injury research communities can enhance the state-of-the-science, provide a unique perspective on novel therapeutic strategies, and improve overall US Government emergency preparedness.

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

Nicotinamide phosphoribosyltransferase (NAMPT) plays a central role in mammalian cell metabolism by contributing to nicotinamide adenine dinucleotide biosynthesis. However, NAMPT activity is not limited to the intracellular compartment, as once secreted, the protein accomplishes diverse functions in the extracellular space. Extracellular NAMPT (eNAMPT, also called visfatin or pre-B-cell colony enhancing factor) has been shown to possess adipocytokine, pro-inflammatory, and pro-angiogenic activities. Numerous studies have reported the association between elevated levels of circulating eNAMPT and various inflammatory and metabolic disorders such as obesity, diabetes, atherosclerosis, arthritis, inflammatory bowel disease, lung injury and cancer. In this review, we summarize the current state of knowledge on eNAMPT biology, proposed roles in disease pathogenesis, and its potential as a disease biomarker. We also briefly discuss the emerging therapeutic approaches for eNAMPT inhibition.

Extracellular nicotinamide phosphoribosyltransferase (eNAMPT) neutralization counteracts T cell immune evasion in breast cancer

BACKGROUND

Nicotinamide phosphoribosyltransferase (NAMPT) is a key intracellular enzyme that participates in nicotinamide adenine dinucleotide (NAD) homeostasis as well as a released cytokine (eNAMPT) that is elevated in inflammatory conditions and in cancer. In patients with breast cancer, circulating eNAMPT is elevated and its plasma levels correlate with prognosis and staging. In light of this, we investigated the contribution of eNAMPT in triple negative mammary carcinoma progression by investigating the effect of its neutralization via a specific neutralizing monoclonal antibody (C269).

METHODS

We used female BALB/c mice injected with 4T1 clone 5 cells and female C57BL6 injected with EO771 cells, evaluating tumoral size, spleen weight and number of metastases. We injected two times a week the anti-eNAMPT neutralizing antibody and we sacrificed the mice after 28 days. Harvested tumors were analyzed by histopathology, flow cytometry, western blot, immunohistochemistry, immunofluorescence and RNA sequencing to define tumor characteristics (isolating tumor infiltrating lymphocytes and tumoral cells) and to investigate the molecular mechanisms behind the observed phenotype. Moreover, we dissected the functional relationship between T cells and tumoral cells using three-dimensional (3D) co-cultures.

RESULTS

The neutralization of eNAMPT with C269 led to decreased tumor size and reduced number of lung metastases. RNA sequencing and functional assays showed that eNAMPT controlled T-cell response via the programmed death-ligand 1/programmed cell death protein 1 (PD-L1/PD-1) axis and its neutralization led to a restoration of antitumoral immune responses. In particular, eNAMPT neutralization was able to activate CD8+IFNγ+GrzB+ T cells, reducing the immunosuppressive phenotype of T regulatory cells.

CONCLUSIONS

These studies indicate for the first time eNAMPT as a novel immunotherapeutic target for triple negative breast cancer.

Nicotinamide restores tissue NAD+ and improves survival in rodent models of cardiac arrest

Metabolic suppression in the ischemic heart is characterized by reduced levels of NAD+ and ATP. Since NAD+ is required for most metabolic processes that generate ATP, we hypothesized that nicotinamide restores ischemic tissue NAD+ and improves cardiac function in cardiomyocytes and isolated hearts, and enhances survival in a mouse model of cardiac arrest. Mouse cardiomyocytes were exposed to 30 min simulated ischemia and 90 min reperfusion. NAD+ content dropped 40% by the end of ischemia compared to pre-ischemia. Treatment with 100 μM nicotinamide (NAM) at the start of reperfusion completely restored the cellular level of NAD+ at 15 min of reperfusion. This rescue of NAD+ depletion was associated with improved contractile recovery as early as 10 min post-reperfusion. In a mouse model of cardiac arrest, 100 mg/kg NAM administered IV immediately after cardiopulmonary resuscitation resulted in 100% survival at 4 h as compared to 50% in the saline group. In an isolated rat heart model, the effect of NAM on cardiac function was measured for 20 min following 18 min global ischemia. Rate pressure product was reduced by 26% in the control group following arrest. Cardiac contractile function was completely recovered with NAM treatment given at the start of reperfusion. NAM restored tissue NAD+ and enhanced production of lactate and ATP, while reducing glucose diversion to sorbitol in the heart. We conclude that NAM can rapidly restore cardiac NAD+ following ischemia and enhance glycolysis and contractile recovery, with improved survival in a mouse model of cardiac arrest.

The NQR Complex Regulates the Immunomodulatory Function of Bacteroides thetaiotaomicron

The gut microbiome and intestinal immune system are engaged in a dynamic interplay that provides myriad benefits to host health. However, the microbiome can also elicit damaging inflammatory responses, and thus establishing harmonious immune-microbiome interactions is essential to maintain homeostasis. Gut microbes actively coordinate the induction of anti-inflammatory responses that establish these mutualistic interactions. Despite this, the microbial pathways that govern this dialogue remain poorly understood. We investigated the mechanisms through which the gut symbiont Bacteroides thetaiotaomicron exerts its immunomodulatory functions on murine- and human-derived cells. Our data reveal that B. thetaiotaomicron stimulates production of the cytokine IL-10 via secreted factors that are packaged into outer membrane vesicles, in a TLR2- and MyD88-dependent manner. Using a transposon mutagenesis-based screen, we identified a key role for the B. thetaiotaomicron-encoded NADH:ubiquinone oxidoreductase (NQR) complex, which regenerates NAD+ during respiration, in this process. Finally, we found that disruption of NQR reduces the capacity of B. thetaiotaomicron to induce IL-10 by impairing biogenesis of outer membrane vesicles. These data identify a microbial pathway with a previously unappreciated role in gut microbe-mediated immunomodulation that may be targeted to manipulate the capacity of the microbiome to shape host immunity.

Pathophysiology and pathogenic mechanisms of pulmonary hypertension: role of membrane receptors, ion channels, and Ca2+ signaling

The pulmonary circulation is a low-resistance, low-pressure, and high-compliance system that allows the lungs to receive the entire cardiac output. Pulmonary arterial pressure is a function of cardiac output and pulmonary vascular resistance, and pulmonary vascular resistance is inversely proportional to the fourth power of the intraluminal radius of the pulmonary artery. Therefore, a very small decrease of the pulmonary vascular lumen diameter results in a significant increase in pulmonary vascular resistance and pulmonary arterial pressure. Pulmonary arterial hypertension is a fatal and progressive disease with poor prognosis. Regardless of the initial pathogenic triggers, sustained pulmonary vasoconstriction, concentric vascular remodeling, occlusive intimal lesions, in situ thrombosis, and vascular wall stiffening are the major and direct causes for elevated pulmonary vascular resistance in patients with pulmonary arterial hypertension and other forms of precapillary pulmonary hypertension. In this review, we aim to discuss the basic principles and physiological mechanisms involved in the regulation of lung vascular hemodynamics and pulmonary vascular function, the changes in the pulmonary vasculature that contribute to the increased vascular resistance and arterial pressure, and the pathogenic mechanisms involved in the development and progression of pulmonary hypertension. We focus on reviewing the pathogenic roles of membrane receptors, ion channels, and intracellular Ca2+ signaling in pulmonary vascular smooth muscle cells in the development and progression of pulmonary hypertension.

The eNAMPT/TLR4 inflammatory cascade drives the severity of intra-amniotic inflammation in pregnancy and predicts infant outcomes

Introduction: Intra-amniotic inflammation (IAI) or chorioamnionitis is a common complication of pregnancy producing significant maternal morbidity/mortality, premature birth and neonatal risk of chronic lung diseases such as bronchopulmonary dysplasia (BPD). We examined eNAMPT (extracellular nicotinamide phosphoribosyltransferase), a critical inflammatory DAMP and TLR4 ligand, as a potential therapeutic target to reduce IAI severity and improve adverse fetal/neonatal outcomes. Methods: Blood/tissue samples were examined in: 1) women with histologically-proven chorioamnionitis, 2) very low birth weight (VLBW) neonates, and 3) a preclinical murine pregnancy model of IAI. Groups of pregnant IAI-exposed mice and pups were treated with an eNAMPT-neutralizing mAb. Results: Human placentas from women with histologically-proven chorioamnionitis exhibited dramatic NAMPT expression compared to placentas without chorioamnionitis. Increased NAMPT expression in whole blood from VLBW neonates (day 5) significantly predicted BPD development. Compared to untreated LPS-challenged murine dams (gestational day 15), pups born to eNAMPT mAb-treated dams (gestational days 15/16) exhibited a > 3-fold improved survival, reduced neonate lung eNAMPT/cytokine levels, and reduced development and severity of BPD and pulmonary hypertension (PH) following postnatal exposure to 100% hyperoxia days 1-14. Genome-wide gene expression studies of maternal uterine and neonatal cardiac tissues corroborated eNAMPT mAb-induced reductions in inflammatory pathway genes. Discussion: The eNAMPT/TLR4 inflammatory pathway is a highly druggable contributor to IAI pathobiology during pregnancy with the eNAMPT-neutralizing mAb a novel therapeutic strategy to decrease premature delivery and improve short- and long-term neonatal outcomes. eNAMPT blood expression is a potential biomarker for early prediction of chronic lung disease among premature neonates.

NAD+ Metabolism and Immune Regulation: New Approaches to Inflammatory Bowel Disease Therapies

Inflammatory bowel disease (IBD), which includes Crohn's disease (CD) and ulcerative colitis (UC), is a multifactorial systemic inflammatory immune response. Nicotinamide adenine dinucleotide (NAD⁺) is a co-enzyme involved in cell signaling and energy metabolism. Calcium homeostasis, gene transcription, DNA repair, and cell communication involve NAD⁺ and its degradation products. There is a growing recognition of the intricate relationship between inflammatory diseases and NAD⁺ metabolism. In the case of IBD, the maintenance of intestinal homeostasis relies on a delicate balance between NAD⁺ biosynthesis and consumption. Consequently, therapeutics designed to target the NAD⁺ pathway are promising for the management of IBD. This review discusses the metabolic and immunoregulatory processes of NAD⁺ in IBD to examine the molecular biology and pathophysiology of the immune regulation of IBD and to provide evidence and theoretical support for the clinical use of NAD⁺ in IBD.

Involvement of eNAMPT/TLR4 inflammatory signaling in progression of non-alcoholic fatty liver disease, steatohepatitis, and fibrosis

Although the progression of non-alcoholic fatty liver disease (NAFLD) from steatosis to steatohepatitis (NASH) and cirrhosis remains poorly understood, a critical role for dysregulated innate immunity has emerged. We examined the utility of ALT-100, a monoclonal antibody (mAb), in reducing NAFLD severity and progression to NASH/hepatic fibrosis. ALT-100 neutralizes eNAMPT (extracellular nicotinamide phosphoribosyltransferase), a novel damage-associated molecular pattern protein (DAMP) and Toll-like receptor 4 (TLR4) ligand. Histologic and biochemical markers were measured in liver tissues and plasma from human NAFLD subjects and NAFLD mice (streptozotocin/high-fat diet-STZ/HFD, 12 weeks). Human NAFLD subjects (n = 5) exhibited significantly increased NAMPT hepatic expression and significantly elevated plasma levels of eNAMPT, IL-6, Ang-2, and IL-1RA compared to healthy controls, with IL-6 and Ang-2 levels significantly increased in NASH non-survivors. Untreated STZ/HFD-exposed mice displayed significant increases in NAFLD activity scores, liver triglycerides, NAMPT hepatic expression, plasma cytokine levels (eNAMPT, IL-6, and TNFα), and histologic evidence of hepatocyte ballooning and hepatic fibrosis. Mice receiving the eNAMPT-neutralizing ALT-100 mAb (0.4 mg/kg/week, IP, weeks 9 to 12) exhibited marked attenuation of each index of NASH progression/severity. Thus, activation of the eNAMPT/TLR4 inflammatory pathway contributes to NAFLD severity and NASH/hepatic fibrosis. ALT-100 is potentially an effective therapeutic approach to address this unmet NAFLD need.

Mechanism of Allosteric Modulation of Nicotinamide Phosphoribosyltransferase to Elevate Cellular NAD. Biochemistry 2023;62:923-933. [PMID: 36746631 DOI: 10.1021/acs.biochem.2c00655]

In aging and disease, cellular nicotinamide adenine dinucleotide (NAD+) is depleted by catabolism to nicotinamide (NAM). NAD+ supplementation is being pursued to enhance human healthspan and lifespan. Activation of nicotinamide phosphoribosyltransferase (NAMPT), the rate-limiting step in NAD+ biosynthesis, has the potential to increase the salvage of NAM. Novel NAMPT-positive allosteric modulators (N-PAMs) were discovered in addition to the demonstration of NAMPT activation by biogenic phenols. The mechanism of activation was revealed through the synthesis of novel chemical probes, new NAMPT co-crystal structures, and enzyme kinetics. Binding to a rear channel in NAMPT regulates NAM binding and turnover, with biochemical observations being replicated by NAD+ measurements in human cells. The mechanism of action of N-PAMs identifies, for the first time, the role of the rear channel in the regulation of NAMPT turnover coupled to productive and nonproductive NAM binding. The tight regulation of cellular NAMPT via feedback inhibition by NAM, NAD+, and adenosine 5'-triphosphate (ATP) is differentially regulated by N-PAMs and other activators, indicating that different classes of pharmacological activators may be engineered to restore or enhance NAD+ levels in affected tissues.

NAMPT and NAPRT serum levels predict response to anti-TNF therapy in inflammatory bowel disease

BACKGROUND

Nicotinamide phosphoribosyltransferase (NAMPT) and nicotinic acid phosphoribosyl transferase (NAPRT) are key intracellular enzymes that participate in the biosynthesis on NAD but have also been shown to be released as proinflammatory cytokines. A number of reports have shown that circulating NAMPT is increased in serum of patients with inflammatory disorders, including inflammatory bowel diseases (IBD), while nothing is known regarding circulating NAPRT and the presence of both cytokines in IBD patient stools. In the present study, we evaluated eNAMPT and eNAPRT levels in a large cohort of IBD patients not on biological therapy and in a subset that then was prescribed biologics.

METHODS

We conducted a retro-perspective study on 180 patients, of which 111 underwent subsequent biological treatment (adalimumab, vedolizumab, and ustekinumab). We analyzed eNAMPT and eNAPRT concentrations in serum and faces of IBD patients, correlating them with response to biologics.

RESULTS

We now report that eNAMPT and eNAPRT are significantly increased in both serum and stools of IBD patients. NAMPT and NAPRT levels correlate with disease severity, with C reactive protein and with serum IL-6 levels. Importantly, levels of NAMPT in patients starting treatment with adalimumab correlate with response failure at three months: patients with levels above 4 ng/ml were significantly less likely to obtain benefit. Serum NAMPT as a biomarker of response yields a sensitivity of 91% and a specificity of 100%.

CONCLUSION

The present work strongly suggests that a prospective trial evaluating eNAMPT and eNAPRT levels in relation to response to biologicals in IBD should be initiated.

The Predictive Role of Extracellular NAPRT for the Detection of Advanced Fibrosis in Biopsy-Proven Non-Alcoholic Fatty Liver Disease

Intrahepatic oxidative stress is a key driver of inflammation and fibrogenesis in non-alcoholic fatty liver disease (NAFLD). We aimed to investigate the role of extracellular Nicotinamide phosphoribosyltransferase (eNAMPT) and extracellular nicotinic acid phosphoribosyltransferase (eNAPRT) for the detection of advanced fibrosis. eNAMPT and eNAPRT were tested in 180 consecutive biopsy-proven NAFLD patients and compared with liver stiffness (LS) and the FIB-4 score. eNAMPT was similarly distributed across fibrosis stages, whereas eNAPRT was increased in patients with advanced fibrosis (p = 0.036) and was associated with advanced fibrosis (OR 1.08, p = 0.016). A multiple stepwise logistic regression model containing significant variables for advanced fibrosis (eNAPRT, type 2 diabetes, age, male sex, ALT) had an area under the curve (AUC) of 0.82 (Se 89.6%, Sp 67.3%, PPV 46.7%, NPV 93.8%) when compared to that of LS (0.79; Se 63.5%, Sp 86.2%, PPV 66.0%, NPV 84.8%) and to that of the FIB-4 score (0.73; Se 80.0%, Sp 56.8%, PPV 44.9%, NPV 86.6%). The use of eNAPRT in clinical practice might allow for the better characterization of NAFLD patients at higher risk of disease progression.

Linkage of NAMPT promoter variants to eNAMPT secretion, plasma eNAMPT levels, and ARDS severity

BACKGROUND AND OBJECTIVES

eNAMPT (extracellular nicotinamide phosphoribosyltransferase), a novel DAMP and TLR4 ligand, is a druggable ARDS therapeutic target with NAMPT promoter SNPs associated with ARDS severity. This study assesses the previously unknown influence of NAMPT promoter SNPs on NAMPT transcription, eNAMPT secretion, and ARDS severity.

METHODS AND DESIGN

Human lung endothelial cells (ECs) transfected with NAMPT promoter luciferase reporters harboring SNPs G-1535A, A-1001 C, and C-948A, were exposed to LPS or LPS/18% cyclic stretch (CS) and NAMPT promoter activity, NAMPT protein expression, and secretion assessed. NAMPT genotypes and eNAMPT plasma measurements (Days 0/7) were assessed in two ARDS cohorts (DISCOVERY n = 428; ALVEOLI n = 103).

RESULTS

Comparisons of minor allelic frequency (MAF) in both ARDS cohorts with the 1000 Human Genome Project revealed the G-1535A and C-948A SNPs to be significantly associated with ARDS in Blacks compared with controls and trended toward significance in non-Hispanic Whites. LPS-challenged and LPS/18% CS-challenged EC harboring the -1535G wild-type allele exhibited significantly increased NAMPT promoter activity (compared with -1535A) with the -1535G/-948A diplotype exhibiting significantly increased NAMPT promoter activity, NAMPT protein expression, and eNAMPT secretion compared with the -1535A/-948 C diplotype. Highly significant increases in Day 0 eNAMPT plasma values were observed in both DISCOVERY and ALVEOLI ARDS cohorts (compared with healthy controls). Among subjects surviving to Day 7, Day 7 eNAMPT values were significantly increased in Day 28 non-survivors versus survivors. The protective -1535A SNP allele drove -1535A/-1001A and -1535A/-948 C diplotypes that confer significantly reduced ARDS risk (compared with -1535G, -1535G/-1001 C, -1535G/-948A), particularly in Black ARDS subjects. NAMPT SNP comparisons within the two ARDS cohorts did not identify significant association with either APACHE III scores or plasma eNAMPT levels.

CONCLUSION

NAMPT SNPs influence promoter activity, eNAMPT protein expression/secretion, plasma eNAMPT levels, and ARDS severity. NAMPT genotypes are a potential tool for stratification in eNAMPT-focused ARDS clinical trials.

eNAMPT/TLR4 inflammatory cascade activation is a key contributor to SLE Lung vasculitis and alveolar hemorrhage

Rationale

Effective therapies to reduce the severity and high mortality of pulmonary vasculitis and diffuse alveolar hemorrhage (DAH) in patients with systemic lupus erythematosus (SLE) is a serious unmet need. We explored whether biologic neutralization of eNAMPT (extracellular nicotinamide phosphoribosyl-transferase), a novel DAMP and Toll-like receptor 4 ligand, represents a viable therapeutic strategy in lupus vasculitis.

Methods

Serum was collected from SLE subjects (n = 37) for eNAMPT protein measurements. In the preclinical pristane-induced murine model of lung vasculitis/hemorrhage, C57BL/6 J mice (n = 5-10/group) were treated with PBS, IgG (1 mg/kg), or the eNAMPT-neutralizing ALT-100 mAb (1 mg/kg, IP or subcutaneously (SQ). Lung injury evaluation (Day 10) included histology/immuno-histochemistry, BAL protein/cellularity, tissue biochemistry, RNA sequencing, and plasma biomarker assessment.

Results

SLE subjects showed highly significant increases in blood NAMPT mRNA expression and eNAMPT protein levels compared to healthy controls. Preclinical pristane-exposed mice studies showed significantly increased NAMPT lung tissue expression and increased plasma eNAMPT levels accompanied by marked increases in alveolar hemorrhage and lung inflammation (BAL protein, PMNs, activated monocytes). In contrast, ALT-100 mAb-treated mice showed significant attenuation of inflammatory lung injury, alveolar hemorrhage, BAL protein, tissue leukocytes, and plasma inflammatory cytokines (eNAMPT, IL-6, IL-8). Lung RNA sequencing showed pristane-induced activation of inflammatory genes/pathways including NFkB, cytokine/chemokine, IL-1β, and MMP signaling pathways, each rectified in ALT-100 mAb-treated mice.

Conclusions

These findings highlight the role of eNAMPT/TLR4-mediated inflammatory signaling in the pathobiology of SLE pulmonary vasculitis and alveolar hemorrhage. Biologic neutralization of this novel DAMP appears to serve as a viable strategy to reduce the severity of SLE lung vasculitis.

Roles of NAD+ in Acute and Chronic Kidney Diseases

Nicotinamide adenine dinucleotide (oxidized form, NAD⁺) is a critical coenzyme, with functions ranging from redox reactions and energy metabolism in mitochondrial respiration and oxidative phosphorylation to being a central player in multiple cellular signaling pathways, organ resilience, health, and longevity. Many of its cellular functions are executed via serving as a co-substrate for sirtuins (SIRTs), poly (ADP-ribose) polymerases (PARPs), and CD38. Kidney damage and diseases are common in the general population, especially in elderly persons and diabetic patients. While NAD⁺ is reduced in acute kidney injury (AKI) and chronic kidney disease (CKD), mounting evidence indicates that NAD⁺ augmentation is beneficial to AKI, although conflicting results exist for cases of CKD. Here, we review recent progress in the field of NAD⁺, mainly focusing on compromised NAD⁺ levels in AKI and its effect on essential cellular pathways, such as mitochondrial dysfunction, compromised autophagy, and low expression of the aging biomarker αKlotho (Klotho) in the kidney. We also review the compromised NAD⁺ levels in renal fibrosis and senescence cells in the case of CKD. As there is an urgent need for more effective treatments for patients with injured kidneys, further studies on NAD⁺ in relation to AKI/CKD may shed light on novel therapeutics.

NAD+ metabolism in peripheral neuropathic pain

Nicotinamide adenine dinucleotide (NAD⁺) is an omnipresent metabolite that participates in redox reactions. Multiple NAD⁺-consuming enzymes are implicated in numerous biological processes, including transcription, signaling, and cell survival. Multiple pieces of evidence have demonstrated that NAD⁺-consuming enzymes, including poly(ADP-ribose) polymerases (PARPs), sirtuins (SIRTs), and sterile alpha and TIR motif-containing 1 (SARM1), play major roles in peripheral neuropathic pain of various etiologies. These NAD⁺ consumers primarily participate in peripheral neuropathic pain via mechanisms such as mitochondrial dysfunction, oxidative stress, and inflammation. Furthermore, NAD⁺ synthase and nicotinamide phosphoribosyltransferase (NAMPT) have recently been found to contribute to the regulation of pain. Here, we review the evidence indicating the involvement of NAD⁺ metabolism in the pathological mechanisms of peripheral neuropathic pain. Advanced understanding of the molecular and cellular mechanisms associated with NAD⁺ in peripheral neuropathic pain will facilitate the development of novel treatment options for diverse types of peripheral neuropathic pain.

TLR4 activation induces inflammatory vascular permeability via Dock1 targeting and NOX4 upregulation

The loss of vascular integrity is a cardinal feature of acute inflammatory responses evoked by activation of the TLR4 inflammatory cascade. Utilizing in vitro and in vivo models of inflammatory lung injury, we explored TLR4-mediated dysregulated signaling that results in the loss of endothelial cell (EC) barrier integrity and vascular permeability, focusing on Dock1 and Elmo1 complexes that are intimately involved in regulation of Rac1 GTPase activity, a well recognized modulator of vascular integrity. Marked reductions in Dock1 and Elmo1 expression was observed in lung tissues (porcine, rat, mouse) exposed to TLR4 ligand-mediated acute inflammatory lung injury (LPS, eNAMPT) in combination with injurious mechanical ventilation. Lung tissue levels of Dock1 and Elmo1 were preserved in animals receiving an eNAMPT-neutralizing mAb in conjunction with highly significant decreases in alveolar edema and lung injury severity, consistent with Dock1/Elmo1 as pathologic TLR4 targets directly involved in inflammation-mediated loss of vascular barrier integrity. In vitro studies determined that pharmacologic inhibition of Dock1-mediated activation of Rac1 (TBOPP) significantly exacerbated TLR4 agonist-induced EC barrier dysfunction (LPS, eNAMPT) and attenuated increases in EC barrier integrity elicited by barrier-enhancing ligands of the S1P1 receptor (sphingosine-1-phosphate, Tysiponate). The EC barrier-disrupting influence of Dock1 inhibition on S1PR1 barrier regulation occurred in concert with: 1) suppressed formation of EC barrier-enhancing lamellipodia, 2) altered nmMLCK-mediated MLC2 phosphorylation, and 3) upregulation of NOX4 expression and increased ROS. These studies indicate that Dock1 is essential for maintaining EC junctional integrity and is a critical target in TLR4-mediated inflammatory lung injury.

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

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.