Butyrate Prevents the Pathogenic Anemia-Inflammation Circuit by Facilitating Macrophage Iron Export.

Most patients with inflammatory bowel disease (IBD) develop anemia, which is attributed to the dysregulation of iron metabolism. Reciprocally, impaired iron homeostasis also aggravates inflammation. How this iron-mediated, pathogenic anemia-inflammation crosstalk is regulated in the gut remains elusive. Herein, it is for the first time revealed that anemic IBD patients exhibit impaired production of short-chain fatty acids (SCFAs), particularly butyrate. Butyrate supplementation restores iron metabolism in multiple anemia models. Mechanistically, butyrate upregulates ferroportin (FPN) expression in macrophages by reducing the enrichment of histone deacetylase (HDAC) at the Slc40a1 promoter, thereby facilitating iron export. By preventing iron sequestration, butyrate not only mitigates colitis-induced anemia but also reduces TNF-α production in macrophages. Consistently, macrophage-conditional FPN knockout mice exhibit more severe anemia and inflammation. Finally, it is revealed that macrophage iron overload impairs the therapeutic effectiveness of anti-TNF-α antibodies in colitis, which can be reversed by butyrate supplementation. Hence, this study uncovers the pivotal role of butyrate in preventing the pathogenic circuit between anemia and inflammation.

Mitochondrial dysfunction-associated microbiota establishes a transmissible refractory response to anti-TNF therapy during ulcerative colitis.

Anti-TNF therapy can induce and maintain a remission status during intestinal bowel disease. However, up to 30% of patients do not respond to this therapy by mechanisms that are unknown. Here, we show that the absence of MCJ, a natural inhibitor of the respiratory chain Complex I, induces gut microbiota changes that are critical determinants of the lack of response in a murine model of DSS-induced inflammation. First, we found that MCJ expression is restricted to macrophages in human colonic tissue. Therefore, we demonstrate by transcriptomic analysis of colon macrophages from DSS-induced mice that MCJ-deficiency is linked to the expression of genes belonging to the FcγR signaling pathway and contains an anti-TNF refractory gene signature identified in ulcerative colitis patients. The gut microbial composition changes observed upon DSS treatment in the MCJ-deficient mice revealed the increased presence of specific colitogenic members, including Ruminococcus gnavus and Oscillospira, which could be associated with the non-response to TNF inhibitors. Further, we show that the presence of a microbiota associated resistance to treatment is dominant and transmissible to responsive individuals. Collectively, our findings underscore the critical role played by macrophage mitochondrial function in the gut ecological niche that can substantially affect not only the severity of inflammation but also the ability to successfully respond to current therapies.

Decreased TMIGD1 aggravates colitis and intestinal barrier dysfunction via the BANF1-NF-κB pathway in Crohn's disease.

BACKGROUND: Disrupted intestinal epithelial barrier is one of the major causes of Crohn's disease (CD). Novel molecular targets for intestinal epithelial barrier are essential to treatment of CD. Transmembrane and immunoglobulin domain-containing protein 1 (TMIGD1) is an adhesion molecule that regulates cell adhesion, migration, and enterocyte differentiation. However, the function and mechanism of TMIGD1 in CD and intestinal epithelial barrier has rarely been studied. Furthermore, the association between TMIGD1 and the clinical features of CD remains unclear. METHODS: Transcriptome analysis on colonic mucosa from CD patients and healthy individuals were performed to identify dysregulated genes. Multi-omics integration of the 1000IBD cohort including genomics, transcriptomics of intestinal biopsies, and serum proteomics identified the association between genes and characteristics of CD. Inflammation was assessed by cytokine production in cell lines, organoids and intestinal-specific Tmigd1 knockout (Tmigd1INT-KO) mice. Epithelial barrier integrity was evaluated by trans-epithelium electrical resistance (TEER), paracellular permeability, and apical junction complex (AJC) expression. Co-immunoprecipitation, GST pull-down assays, mass spectrometry, proteomics, and transcriptome analysis were used to explore downstream mechanisms. RESULTS: Multi-omics integration suggested that TMIGD1 was negatively associated with inflammatory characteristics of CD. TMIGD1 was downregulated in inflamed intestinal mucosa of patients with CD and mice colitis models. Tmigd1INT-KO mice were more susceptible to chemically induced colitis. In epithelial cell lines and colonic organoids, TMIGD1 knockdown caused impaired intestinal barrier integrity evidenced by increased paracellular permeability and reduced TEER and AJC expression. TMIGD1 knockdown in intestinal epithelial cells also induced pro-inflammatory cytokine production. Mechanistically, TMIGD1 directly interacted with cytoplasmic BAF nuclear assembly factor 1 (BANF1) to inhibit NF-κB activation. Exogenous expression of TMIGD1 and BANF1 restored intestinal barrier function and inhibited inflammation in vitro and in vivo. TMIGD1 expression predicted response to anti-TNF treatment in patients with CD. CONCLUSIONS: Our study demonstrated that TMIGD1 maintained intestinal barrier integrity and inactivated inflammation, and was therefore a potential therapeutic target for CD.

A macrophage plasma membrane-coated and DNA structured nanomedicine targets to alleviate rheumatoid arthritis via dual inhibition to TNF-α and NF-κB.

High heterogenicity of rheumatoid arthritis (RA) leads to poor response in many patients. Combined therapies that simultaneously inhibit multiple proinflammatory targets may improve anti-RA efficacy. However, which monotherapies to combine and how to achieve the combination are critical issues. Here, we design a macrophage plasma membrane-coated and DNA structured nanomedicine to achieve a dual inhibitory therapy to Tumor necrosis factor alpha (TNF-α) and NF-κB. An anti-NF-κB decoy oligodeoxynucleotides (dODN) is first conjugated to a DNA cage with precise numbers and locations (Cage-dODN). Meanwhile, an anti-TNF-α siRNA is anchored to extracted macrophage plasma membrane (siRNA@M). Subsequently, siRNA@M is used to encapsulate Cage-dODN to fabricate siRNA@M(Cage-dODN) (siMCO). The size and zeta potential of siMCO are 63.1 ± 15.7 nm and -20.7 ± 3.8 mV respectively. siMCO shows increased intracellular uptake by inflamed macrophages and enhanced accumulation in inflamed mouse paws. siMCO also reduces pro-inflammatory factors at genetic and protein levels, alleviates arthritic symptoms, and shows no influence to major blood components. These results show that siMCO is a potential targeted, efficient, and safe dual inhibitory therapy for the treatment of inflammatory arthritis. The macrophage plasma membrane can be utilized to improve the targeting, stability, and efficacy of DNA structured nanomedicines.

Dietary palmitoleic acid reprograms gut microbiota and improves biological therapy against colitis.

Magnitude and diversity of gut microbiota and metabolic systems are critical in shaping human health and diseases, but it remains largely unclear how complex metabolites may selectively regulate gut microbiota and determine health and diseases. Here, we show that failures or compromised effects of anti-TNF-α therapy in inflammatory bowel diseases (IBD) patients were correlated with intestinal dysbacteriosis with more pro-inflammatory bacteria, extensive unresolved inflammation, failed mucosal repairment, and aberrant lipid metabolism, particularly lower levels of palmitoleic acid (POA). Dietary POA repaired gut mucosal barriers, reduced inflammatory cell infiltrations and expressions of TNF-α and IL-6, and improved efficacy of anti-TNF-α therapy in both acute and chronic IBD mouse models. Ex vivo treatment with POA in cultured inflamed colon tissues derived from Crohn's disease (CD) patients reduced pro-inflammatory signaling/cytokines and conferred appreciable tissue repairment. Mechanistically, POA significantly upregulated the transcriptional signatures of cell division and biosynthetic process of Akkermansia muciniphila, selectively increased the growth and abundance of Akkermansia muciniphila in gut microbiota, and further reprogrammed the composition and structures of gut microbiota. Oral transfer of such POA-reprogrammed, but not control, gut microbiota induced better protection against colitis in anti-TNF-α mAb-treated recipient mice, and co-administration of POA with Akkermansia muciniphila showed significant synergistic protections against colitis in mice. Collectively, this work not only reveals the critical importance of POA as a polyfunctional molecular force to shape the magnitude and diversity of gut microbiota and therefore promote the intestinal homeostasis, but also implicates a new potential therapeutic strategy against intestinal or abenteric inflammatory diseases.

Irisin, a novel metabolic biomarker in hidradenitis suppurativa: correlation with clinical responsivity to anti-TNF-α therapy.

BACKGROUND: Suppurative hidradenitis (HS) is a chronic, inflammatory skin disease of the hair follicle unit. Adalimumab (ADA), an anti-tumor necrosis factor (TNF) alpha, is the only FDA-approved biologic available for the management of HS. TNF-α can also affect glucose and lipid metabolism, promoting insulin resistance and obesity by negatively regulating irisin, a new adipomyokine. METHODS: A total of 17 HS patients were enrolled in the study. Blood samples were collected from all patients at baseline and week-16. Plasma irisin levels were detected by ELISA assay. RESULTS: Plasma irisin levels were significantly increased after 16 weeks of ADA therapy in HS patients compared to baseline. Interestingly, plasma irisin levels correlated with clinical response. CONCLUSIONS: The link between skin inflammatory diseases and metabolic disorders has aroused great interest in order to research new biomarkers able to early identify metabolic comorbidities. Among these emerging biomarkers, irisin is one of the most recently discovered. We examined a group of patients affected by moderate-severe HS treated with anti-TNF-α, demonstrating for the first time how a therapy able to block an inflammatory cytokine can also affect the metabolic profile by modifying levels of irisin.

The mechanisms and functions of TNF-α in intervertebral disc degeneration.

Low back pain (LBP) is one of the most common health problems in people's lives, which brings a massive burden to clinicians, and the leading cause of LBP is intervertebral disc degeneration (IDD). IDD is mainly caused by factors such as aging, mechanical stress, and lack of nutrition. The pathological mechanism of IDD is very complex, involving inflammatory response, cell metabolism disorder, and so on. Unfortunately, in the current treatment of IDD, only relieving symptoms as the primary means of relieving a patient's pain cannot effectively inhibit or reverse the progression of IDD. Tumor necrosis factor-α (TNF-α) is a multifunctional pro-inflammatory factor involved in many diseases' pathological processes. With the in-depth study of the pathological mechanism of IDD, more and more evidence has shown that TNF-α is an essential activator of IDD, which is related to the metabolic disorder, inflammatory responses, apoptosis, and other pathological processes of extracellular dissociation in the intervertebral disc. Therefore, anti-TNF-α therapy is an effective therapeutic target for alleviating IDD, especially in inhibiting extracellular matrix degradation and reducing inflammatory responses. This article reviews the pathological role of TNF-α in IDD and the latest research progress of TNF-α inhibitors in treating IDD.

Additive efficacy of a bispecific anti-TNF/IL-6 nanobody compound in translational models of rheumatoid arthritis.

Rheumatoid arthritis (RA) is one of the most common autoimmune diseases affecting primarily the joints. Despite successful therapies including antibodies against tumor necrosis factor (TNF) and interleukin-6 (IL-6) receptor, only 20 to 30% of patients experience remission. We studied whether inhibiting both TNF and IL-6 would result in improved efficacy. Using backtranslation from single-cell RNA sequencing (scRNA-seq) data from individuals with RA, we hypothesized that TNF and IL-6 act synergistically on fibroblast-like synoviocytes (FLS) and T cells. Coculture of FLS from individuals with RA and T cells supported this hypothesis, revealing effects on both disease-driving pathways and biomarkers. Combining anti-TNF and anti-IL-6 antibodies in collagen-induced arthritis (CIA) mouse models resulted in sustained long-term remission, improved histology, and effects on bone remodeling pathways. These promising data initiated the development of an anti-TNF/IL-6 bispecific nanobody compound 1, with similar potencies against TNF and IL-6. We observed additive efficacy of compound 1 in a FLS/T cell coculture affecting arthritis and T helper 17 (TH17) pathways. This nanobody compound transcript signature inversely overlapped with described RA endotypes, indicating a potential efficacy in a broader patient population. In summary, we showed superiority of a bispecific anti-TNF/IL-6 nanobody compound or combination treatment over monospecific treatments in both in vitro and in vivo models. We anticipate improved efficacy in upcoming clinical studies.

TNF or EGFR inhibition equally block AKI-to-CKD transition: opportunities for etanercept treatment.

BACKGROUND: Inflammation is a key driver of the transition of acute kidney injury to progressive fibrosis and chronic kidney disease (AKI-to-CKD transition). Blocking a-disintegrin-and-metalloprotease-17 (ADAM17)-dependent ectodomain shedding, in particular of epidermal growth factor receptor (EGFR) ligands and of the type 1 inflammatory cytokine tumor necrosis factor (TNF), reduces pro-inflammatory and pro-fibrotic responses after ischemic AKI or unilateral ureteral obstruction (UUO), a classical fibrosis model. Metalloprotease or EGFR inhibition show significant undesirable side effects in humans. In retrospective studies anti-TNF biologics reduce the incidence and progression of CKD in humans. Whether TNF has a role in AKI-to-CKD transition and how TNF inhibition compares to EGFR inhibition is largely unknown. METHODS: Mice were subjected to bilateral renal ischemia-reperfusion injury or unilateral ureteral obstruction. Kidneys were analyzed by histology, immunohistochemistry, qPCR, western blot, mass cytometry, scRNA sequencing, and cytokine profiling. RESULTS: Here we show that TNF or EGFR inhibition reduce AKI-to-CKD transition and fibrosis equally by about 25%, while combination has no additional effect. EGFR inhibition reduced kidney TNF expression by about 50% largely by reducing accumulation of TNF expressing immune cells in the kidney early after AKI, while TNF inhibition did not affect EGFR activation or immune cell accumulation. Using scRNAseq data we show that TNF is predominantly expressed by immune cells in AKI but not in proximal tubule cells (PTC), and PTC-TNF knockout did not affect AKI-to-CKD transition in UUO. Thus, the anti-inflammatory and anti-fibrotic effects of the anti-TNF biologic etanercept in AKI-to-CKD transition rely on blocking TNF that is released from immune cells recruited or accumulating in response to PTC-EGFR signals. CONCLUSION: Short-term anti-TNF biologics during or after AKI could be helpful in the prevention of AKI-to-CKD transition.

Differential involvement of LUBAC-mediated linear ubiquitination in intestinal epithelial cells and macrophages during intestinal inflammation.

Disruption of the intestinal epithelial barrier and dysregulation of macrophages are major factors contributing to the pathogenesis of inflammatory bowel diseases (IBDs). Activation of NF-κB and cell death are involved in maintaining intestinal homeostasis in a cell type-dependent manner. Although both are regulated by linear ubiquitin chain assembly complex (LUBAC)-mediated linear ubiquitination, the physiological relevance of linear ubiquitination to intestinal inflammation remains unexplored. Here, we used two experimental mouse models of IBD (intraperitoneal LPS and oral dextran sodium sulfate [DSS] administration) to examine the role of linear ubiquitination in intestinal epithelial cells (IECs) and macrophages during intestinal inflammation. We did this by deleting the linear ubiquitination activity of LUBAC specifically from IECs or macrophages. Upon LPS administration, loss of ligase activity in IECs induced mucosal inflammation and augmented IEC death. LPS-mediated death of LUBAC-defective IECs was triggered by TNF. IEC death was rescued by an anti-TNF antibody, and TNF (but not LPS) induced apoptosis of organoids derived from LUBAC-defective IECs. However, augmented TNF-mediated IEC death did not overtly affect the severity of colitis after DSS administration. By contrast, defective LUBAC ligase activity in macrophages ameliorated DSS-induced colitis by attenuating both infiltration of macrophages and expression of inflammatory cytokines. Decreased production of macrophage chemoattractant MCP-1/CCL2, as well as pro-inflammatory IL-6 and TNF, occurred through impaired activation of NF-κB and ERK via loss of ligase activity in macrophages. Taken together, these results indicate that both intraperitoneal LPS and oral DSS administrations are beneficial for evaluating epithelial integrity under inflammatory conditions, as well as macrophage functions in the event of an epithelial barrier breach. The data clarify the cell-specific roles of linear ubiquitination as a critical regulator of TNF-mediated epithelial integrity and macrophage pro-inflammatory responses during intestinal inflammation. © 2022 The Pathological Society of Great Britain and Ireland.

A Novel LC-MS/MS-Based Method for the Diagnosis of ADA2 Deficiency from Dried Plasma Spot.

Adenosine Deaminase 2 Deficiency (DADA2) (OMIM: 607575) is a monogenic, autoinflammatory disease caused by the loss of functional homozygous or heterozygous mutations in the ADA 2 gene (previously CECR1, Cat Eye Syndrome Chromosome Region 1). A timely diagnosis is crucial to start Anti-TNF therapies that are efficacious in controlling the disease. The confirmation of DADA2 is based on DNA sequencing and enzymatic assay. It is, thus, very important to have robust and reliable assays that can be rapidly utilized in specialized laboratories that can centralize samples from other centers. In this paper, we show a novel enzymatic assay based on liquid chromatography-tandem mass spectrometry that allows the accurate determination of the ADA2 enzyme activity starting from very small amounts of plasma spotted on filter paper (dried plasma spot). The method allows significantly distinguishing healthy controls from affected patients and carriers and could be of help in implementing the diagnostic workflow of DADA2.

A cross-linked anti-TNF-α aptamer for neutralization of TNF-α-induced cutaneous Shwartzman phenomenon: A simple and novel approach for improving aptamers' affinity and efficiency.

To increase the efficiency of aptamers to their targets, a simple and novel method has been developed based on aptamer oligomerization. To this purpose, previously anti-human TNF-α aptamer named T1-T4 was trimerized through a trimethyl aconitate core for neutralization of in vitro and in vivo of TNF-α. At first, 54 mer T1-T4 aptamers with 5'-NH2 groups were covalently coupled to three ester residues in the trimethyl aconitate. In vitro activity of novel anti-TNF-α aptamer and its dissociation constant (Kd ) was done using the L929 cell cytotoxicity assay. In vivo anti-TNF-α activity of new oligomerized aptamer was assessed in a mouse model of cutaneous Shwartzman. Anchoring of three T1-T4 aptamers to trimethyl aconitate substituent results in formation of the 162 mer fragment, which was well revealed by gel electrophoresis. In vitro study indicated that the trimerization of T1-T4 aptamer significantly improved its anti-TNF-α activity compared to non-modified aptamers (P < 0.0001) from 40% to 60%. The determination of Kd showed that trimerization could effectively enhance Kd of aptamer from 67 nM to 36 nM. In vivo study showed that trimer aptamer markedly reduced mean scar size from 15.2 ± 1.2 mm to 1.6 ± 0.1 mm (P < 0.0001), which prevent the formation of skin lesions. In vitro and in vivo studies indicate that trimerization of anti-TNF-α aptamer with a novel approach could improve the anti-TNF-α activity and therapeutic efficacy. According to our findings, a new anti-TNF-α aptamer described here could be considered an appropriate therapeutic agent in treating several inflammatory diseases.

The Spectrum of the Deficiency of Adenosine Deaminase 2: An Observational Analysis of a 60 Patient Cohort.

The deficiency of adenosine deaminase 2 (DADA2) is an autosomal recessively inherited disease that has undergone extensive phenotypic expansion since being first described in patients with fevers, recurrent strokes, livedo racemosa, and polyarteritis nodosa in 2014. It is now recognized that patients may develop multisystem disease that spans multiple medical subspecialties. Here, we describe the findings from a large single center longitudinal cohort of 60 patients, the broad phenotypic presentation, as well as highlight the cohort's experience with hematopoietic cell transplantation and COVID-19. Disease manifestations could be separated into three major phenotypes: inflammatory/vascular, immune dysregulatory, and hematologic, however, most patients presented with significant overlap between these three phenotype groups. The cardinal features of the inflammatory/vascular group included cutaneous manifestations and stroke. Evidence of immune dysregulation was commonly observed, including hypogammaglobulinemia, absent to low class-switched memory B cells, and inadequate response to vaccination. Despite these findings, infectious complications were exceedingly rare in this cohort. Hematologic findings including pure red cell aplasia (PRCA), immune-mediated neutropenia, and pancytopenia were observed in half of patients. We significantly extended our experience using anti-TNF agents, with no strokes observed in 2026 patient months on TNF inhibitors. Meanwhile, hematologic and immune features had a more varied response to anti-TNF therapy. Six patients received a total of 10 allogeneic hematopoietic cell transplant (HCT) procedures, with secondary graft failure necessitating repeat HCTs in three patients, as well as unplanned donor cell infusions to avoid graft rejection. All transplanted patients had been on anti-TNF agents prior to HCT and received varying degrees of reduced-intensity or non-myeloablative conditioning. All transplanted patients are still alive and have discontinued anti-TNF therapy. The long-term follow up afforded by this large single-center study underscores the clinical heterogeneity of DADA2 and the potential for phenotypes to evolve in any individual patient.

TNF Inhibitor Pomalidomide Sensitizes Glioblastoma Cells to EGFR Inhibition.

OBJECTIVE: Epidermal growth factor receptor (EGFR) is one of the important targets in cancer treatment. However, EGFR inhibitors are reported to be ineffective in treating glioblastoma (GBM). In this study, we evaluated the potential mechanism of GBM resistance to EGFR inhibition. METHODS: EGFR, p38, extracellular signal-related kinase (ERK), and c-Jun N-terminal kinase (JNK) expression levels were detected by western blotting. Cell viability was evaluated by the MTT assay. Tumor necrosis factor (TNF) mRNA expression was assessed by qRT-PCR. TNF-α expression was detected by ELISA. The combined effect of EGFR inhibitor (afatinib) and TNF inhibitor (pomalidomide) was evaluated in xenograft athymic mouse model of GBM. RESULTS: Upon blocking TNF, GBM sensitivity to EGFR inhibitors was observed to recover. The combination of afatinib and pomalidomide was found to effectively inhibit cell growth of EG-FR-expressing GBM. In addition, the p38/JNK/ERK pathway was activated following EGFR inhibition. CONCLUSIONS: We demonstrated that GBM resistance to EGFR inhibition was mediated by the activation of TNF. The combination of EGFR inhibitor and TNF inhibitor may have potential clinical implication in treating patients with EGFR-positive GBM.

Pharmacomicrobiomics in inflammatory arthritis: gut microbiome as modulator of therapeutic response.

In the past three decades, extraordinary advances have been made in the understanding of the pathogenesis of, and treatment options for, inflammatory arthritides, including rheumatoid arthritis and spondyloarthritis. The use of methotrexate and subsequently biologic therapies (such as TNF inhibitors, among others) and oral small molecules have substantially improved clinical outcomes for many patients with inflammatory arthritis; for others, however, these agents do not substantially improve their symptoms. The emerging field of pharmacomicrobiomics, which investigates the effect of variations within the human gut microbiome on drugs, has already provided important insights into these therapeutics. Pharmacomicrobiomic studies have demonstrated that human gut microorganisms and their enzymatic products can affect the bioavailability, clinical efficacy and toxicity of a wide array of drugs through direct and indirect mechanisms. This discipline promises to facilitate the advent of microbiome-based precision medicine approaches in inflammatory arthritis, including strategies for predicting response to treatment and for modulating the microbiome to improve response to therapy or reduce drug toxicity.

TNF-α antagonists differentially induce TGF-ß1-dependent resuscitation of dormant-like Mycobacterium tuberculosis.

TNF-α- as well as non-TNF-α-targeting biologics are prescribed to treat a variety of immune-mediated inflammatory disorders. The well-documented risk of tuberculosis progression associated with anti-TNF-α treatment highlighted the central role of TNF-α for the maintenance of protective immunity, although the rate of tuberculosis detected among patients varies with the nature of the drug. Using a human, in-vitro granuloma model, we reproduce the increased reactivation rate of tuberculosis following exposure to Adalimumab compared to Etanercept, two TNF-α-neutralizing biologics. We show that Adalimumab, because of its bivalence, specifically induces TGF-ß1-dependent Mycobacterium tuberculosis (Mtb) resuscitation which can be prevented by concomitant TGF-ß1 neutralization. Moreover, our data suggest an additional role of lymphotoxin-α-neutralized by Etanercept but not Adalimumab-in the control of latent tuberculosis infection. Furthermore, we show that, while Secukinumab, an anti-IL-17A antibody, does not revert Mtb dormancy, the anti-IL-12-p40 antibody Ustekinumab and the recombinant IL-1RA Anakinra promote Mtb resuscitation, in line with the importance of these pathways in tuberculosis immunity.

Fibroblast growth factor-inducible 14 mediates macrophage infiltration in heart to promote pressure overload-induced cardiac dysfunction.

AIMS: Heart failure (HF) is characterized by compromised cardiac structure and function. Previous work has identified a link between upregulation of pro-inflammatory cytokines and HF. Tumor necrosis factor (TNF)-like weak inducer of apoptosis (TWEAK) is a pro-inflammatory cytokine, which binds to fibroblast growth factor inducible 14 (Fn14), a ubiquitously expressed cell-surface receptor. The objective of this study was to investigate the role of TWEAK/Fn14 pathway in promoting cardiac inflammation under non ischemic stress conditions. MAIN METHODS: Wild type (WT) and Fn14 knock out (Fn14-/-) mice were subjected to pressure overload [transaortic constriction (TAC)] for 1 or 6 weeks. A subset of WT TAC animals were treated with the Fn14 antagonist L524-0366. Cardiac function was measured by echocardiography. Cardiac fibrosis and macrophage infiltration were quantified using immunohistochemistry and flow cytometry, respectively. Cardiac fibroblasts were isolated for quantifying TWEAK-induced chemokine release. KEY FINDINGS: Fn14-/- mice displayed improved cardiac function, reduced fibrosis and lower macrophage infiltration in heart compared to WT following TAC. L524-0366 mitigated maladaptive remodeling with TAC. TWEAK induced secretion of the pro-inflammatory chemokine, monocyte chemoattractant protein 1 from WT but not Fn14-/- fibroblasts in vitro, in part through activation of non-canonical NF-κB signaling. Finally, Fn14 expression was increased in mouse following TAC and in human failing hearts. SIGNIFICANCE: Our findings support an important role for the TWEAK/Fn14 promoting macrophage infiltration and fibrosis in heart under non-ischemic stress, with potential for therapeutic intervention to improve cardiac function in the setting of HF.

Predictors of anti-TNF treatment failure in anti-TNF-naive patients with active luminal Crohn's disease: a prospective, multicentre, cohort study.

BACKGROUND: Anti-TNF drugs are effective treatments for the management of Crohn's disease but treatment failure is common. We aimed to identify clinical and pharmacokinetic factors that predict primary non-response at week 14 after starting treatment, non-remission at week 54, and adverse events leading to drug withdrawal. METHODS: The personalised anti-TNF therapy in Crohn's disease study (PANTS) is a prospective observational UK-wide study. We enrolled anti-TNF-naive patients (aged ≥6 years) with active luminal Crohn's disease at the time of first exposure to infliximab or adalimumab between March 7, 2013, and July 15, 2016. Patients were evaluated for 12 months or until drug withdrawal. Demographic data, smoking status, age at diagnosis, disease duration, location, and behaviour, previous medical and drug history, and previous Crohn's disease-related surgeries were recorded at baseline. At every visit, disease activity score, weight, therapy, and adverse events were recorded; drug and total anti-drug antibody concentrations were also measured. Treatment failure endpoints were primary non-response at week 14, non-remission at week 54, and adverse events leading to drug withdrawal. We used regression analyses to identify which factors were associated with treatment failure. FINDINGS: We enrolled 955 patients treated with infliximab (753 with originator; 202 with biosimilar) and 655 treated with adalimumab. Primary non-response occurred in 295 (23·8%, 95% CI 21·4-26·2) of 1241 patients who were assessable at week 14. Non-remission at week 54 occurred in 764 (63·1%, 60·3-65·8) of 1211 patients who were assessable, and adverse events curtailed treatment in 126 (7·8%, 6·6-9·2) of 1610 patients. In multivariable analysis, the only factor independently associated with primary non-response was low drug concentration at week 14 (infliximab: odds ratio 0·35 [95% CI 0·20-0·62], p=0·00038; adalimumab: 0·13 [0·06-0·28], p<0·0001); the optimal week 14 drug concentrations associated with remission at both week 14 and week 54 were 7 mg/L for infliximab and 12 mg/L for adalimumab. Continuing standard dosing regimens after primary non-response was rarely helpful; only 14 (12·4% [95% CI 6·9-19·9]) of 113 patients entered remission by week 54. Similarly, week 14 drug concentration was also independently associated with non-remission at week 54 (0·29 [0·16-0·52] for infliximab; 0·03 [0·01-0·12] for adalimumab; p<0·0001 for both). The proportion of patients who developed anti-drug antibodies (immunogenicity) was 62·8% (95% CI 59·0-66·3) for infliximab and 28·5% (24·0-32·7) for adalimumab. For both drugs, suboptimal week 14 drug concentrations predicted immunogenicity, and the development of anti-drug antibodies predicted subsequent low drug concentrations. Combination immunomodulator (thiopurine or methotrexate) therapy mitigated the risk of developing anti-drug antibodies (hazard ratio 0·39 [95% CI 0·32-0·46] for infliximab; 0·44 [0·31-0·64] for adalimumab; p<0·0001 for both). For infliximab, multivariable analysis of immunododulator use, and week 14 drug and anti-drug antibody concentrations showed an independent effect of immunomodulator use on week 54 non-remission (odds ratio 0·56 [95% CI 0·38-0·83], p=0·004). INTERPRETATION: Anti-TNF treatment failure is common and is predicted by low drug concentrations, mediated in part by immunogenicity. Clinical trials are required to investigate whether personalised induction regimens and treatment-to-target dose intensification improve outcomes. FUNDING: Guts UK, Crohn's and Colitis UK, Cure Crohn's Colitis, AbbVie, Merck Sharp and Dohme, Napp Pharmaceuticals, Pfizer, and Celltrion.