TNF receptor signalling in autoinflammatory diseases

A rare missense p.C125Y mutation in the TNFRSF1A gene identified in a Chinese family with tumor necrosis factor receptor-associated periodic fever syndrome

Background

Tumor necrosis factor receptor-associated periodic syndrome (TRAPS) is a rare autosomal dominant disorder with a low incidence in Asia. The most frequent clinical manifestations include fever, rash, myalgia, joint pain and abdominal pain. Misdiagnosis rates are high because of the clinical and genetic variability of the disease. The pathogenesis of TRAPS is complex and yet to be fully defined. Early genetic diagnosis is the key to precise treatment.

Methods

In this study, a Chinese family with suspected TRAPS were analyzed by genome-wide SNP genotyping, linkage analysis and targeted sequencing for identification of mutations in causative genes. To study the pathogenicity of the identified gene mutation, we performed a conservation analysis of the mutation site and protein structure analysis. Flow cytometry was used to detect TNFRSF1A shedding and quantitative real-time PCR were used to assess the activation of unfolded protein response (UPR) in the mutation carriers and healthy individuals.

Results

A typical TRAPS family history, with a pattern of autosomal dominant inheritance, led to the identification of a rare mutation in the TNFRSF1A gene (c.G374A [p.Cys125Tyr]) with unknown significance. The patient responded well to corticosteroids, and long-term therapy with colchicine effectively reduced the inflammatory attacks. No amyloid complications occurred during the 6-year follow-up. In silico protein analysis showed that the mutation site is highly conversed and the mutation prevents the formation of intrachain disulfide bonds in the protein. Despite a normal shedding of the TNFRSF1A protein from stimulated monocytes in the TRAPS patients with p.C125Y mutation, the expression of CHOP and the splicing of XBP1 was significantly higher than healthy controls, suggesting the presence of an activation UPR.

Conclusion

This is the first report of a Chinese family with the rare p.C125Y mutation in TNFRSF1A. The p.C125Y mutation does not result in aberrant receptor shedding, but instead is associated with an activated UPR in these TRAPS patients, which may provide new insights into the pathogenesis of this rare mutation in TRAPS.

A de novo dominant-negative variant is associated with OTULIN-related autoinflammatory syndrome

OTULIN-related autoinflammatory syndrome (ORAS), a severe autoinflammatory disease, is caused by biallelic pathogenic variants of OTULIN, a linear ubiquitin-specific deubiquitinating enzyme. Loss of OTULIN attenuates linear ubiquitination by inhibiting the linear ubiquitin chain assembly complex (LUBAC). Here, we report a patient who harbors two rare heterozygous variants of OTULIN (p.P152L and p.R306Q). We demonstrated accumulation of linear ubiquitin chains upon TNF stimulation and augmented TNF-induced cell death in mesenchymal stem cells differentiated from patient-derived iPS cells, which confirms that the patient has ORAS. However, although the de novo p.R306Q variant exhibits attenuated deubiquitination activity without reducing the amount of OTULIN, the deubiquitination activity of the p.P152L variant inherited from the mother was equivalent to that of the wild-type. Patient-derived MSCs in which the p.P152L variant was replaced with wild-type also exhibited augmented TNF-induced cell death and accumulation of linear chains. The finding that ORAS can be caused by a dominant-negative p.R306Q variant of OTULIN furthers our understanding of disease pathogenesis.

Physiology of deep closed circuit rebreather mixed gas diving: vascular gas emboli and biological changes during a week-long liveaboard safari

Introduction: Diving decompression theory hypothesizes inflammatory processes as a source of micronuclei which could increase related risks. Therefore, we tested 10 healthy, male divers. They performed 6-8 dives with a maximum of two dives per day at depths ranging from 21 to 122 msw with CCR mixed gas diving. Methods: Post-dive VGE were counted by echocardiography. Saliva and urine samples were taken before and after each dive to evaluate inflammation: ROS production, lipid peroxidation (8-iso-PGF2), DNA damage (8-OH-dG), cytokines (TNF-α, IL-6, and neopterin). Results: VGE exhibits a progressive reduction followed by an increase (p < 0.0001) which parallels inflammation responses. Indeed, ROS, 8-iso-PGF2, IL-6 and neopterin increases from 0.19 ± 0.02 to 1.13 ± 0.09 μmol.min-1 (p < 0.001); 199.8 ± 55.9 to 632.7 ± 73.3 ng.mg-1 creatinine (p < 0.0001); 2.35 ± 0.54 to 19.5 ± 2.96 pg.mL-1 (p < 0.001); and 93.7 ± 11.2 to 299 ± 25.9 μmol·mol-1 creatinine (p = 0.005), respectively. The variation after each dive was held constant around 158.3% ± 6.9% (p = 0.021); 151.4% ± 5.7% (p < 0.0001); 176.3% ± 11.9% (p < 0.0001); and 160.1% ± 5.6% (p < 0.001), respectively. Discussion: When oxy-inflammation reaches a certain level, it exceeds hormetic coping mechanisms allowing second-generation micronuclei substantiated by an increase of VGE after an initial continuous decrease consistent with a depletion of "first generation" pre-existing micronuclei.

Long-Term Efficacy and Safety of Canakinumab in Patients With Tumor Necrosis Factor Receptor-Associated Periodic Syndrome: Results From a Phase III Trial

OBJECTIVE

We aimed at assessing efficacy, safety, and tolerability of canakinumab in patients with tumor necrosis factor receptor-associated periodic syndrome (TRAPS) during a 72-week long-term, open-label extension of the CLUSTER study.

METHODS

Patients received open-label canakinumab 150 or 300 mg, either every 4 weeks (q4w) or every 8 weeks, with up-titration permitted after on-treatment flares (maximum dose: 300 mg q4w). Efficacy assessments included physician global assessment of disease activity, number of flares, and serum C-reactive protein (CRP) and serum amyloid A protein (SAA) levels. Adverse events were also reported. Results are described for the overall population and according to the cumulative dose of canakinumab adjusted for body weight (<36 mg/kg or ≥36 mg/kg).

RESULTS

Of 53 patients entering the final phase (epoch 4) of CLUSTER, 51 completed the treatment. At the end of epoch 4, >94% of patients achieved no or minimal disease activity. Most patients had either no (69.8%) or one flare (24.5%), whereas at baseline, the median number of flares was 9.0 per year. Median CRP levels remained at <10 mg/L. Median SAA concentrations were largely unchanged, with medians of 11.5 mg/L and 14.5 mg/L in the <36 mg/kg and ≥36 mg/kg groups, respectively, at the end of the study. No unexpected safety findings were identified.

CONCLUSION

Control of disease activity, with low flare incidence, was maintained with long-term canakinumab treatment in patients with TRAPS during the 72-week final epoch of the CLUSTER study, with no new safety findings.

Correlation of Increased Soluble Tumor Necrosis Factor Receptor 1 with Mortality and Dependence on Treatment in Non-Small-Cell Lung Cancer Patients: A Longitudinal Cohort Study

BACKGROUND

Tumor necrosis factor (TNF) is a multipotent cytokine involved in inflammation and anti-tumor activity. TNF-α exerts its function upon binding to TNF-receptor 1 (TNF-R1) and TNF-receptor 2 (TNF-R2). This study investigates the relationship of soluble (s) TNF-R1 levels in non-small-cell lung cancer (NSCLC) patients with treatment and overall survival.

METHODS

In total, 134 NSCLC patients treated at the Medical Faculty of Martin Luther University Halle-Wittenberg between 2017 and 2019 were included in this study. Serum levels of sTNF-R1 were measured via ELISA at baseline and during and after treatment. A linear mixed-effects model was used to assess sTNF-R1 changes over time. Linear regression was applied to investigate the association between clinical characteristics and changes in sTNF-R1. Cox regression models were used to estimate associations with overall mortality.

RESULTS

The estimated average sTNFR-1 at baseline was 2091.71 pg/mL, with a change of 6.19 pg/mL per day. Cox models revealed that the individual change in sTNF-R1 was more strongly associated with mortality than its baseline value, especially after adjusting for covariates.

CONCLUSIONS

This study provides evidence that the individual change in sTNF-R1 levels during and after treatment were associated with the risk of mortality, suggesting the use of the sTNF-R1 trajectory as a prognostic marker.

Exploration of molecular mechanism of Huanglian-Muxiang-Roudoukou formula in treating ulcerative colitis based on gene expression omnibus chip data mining combined with network pharmacology and molecular docking

BACKGROUND

Huanglian-Muxiang-Roudoukou (HMR) formula was recorded in the book of "Pediatric Medicine Prescription". It can improve the clinical symptoms of ulcerative colitis (UC). Using network pharmacology and other methods to study its biological mechanism is helpful to better explore the resources of traditional Chinese medicine and promote the modern development and application of traditional Chinese medicine in the prevention and treatment of UC.

AIM

To explore the potential molecular mechanism of HMR in the treatment of UC based on gene expression omnibus (GEO) chip data mining, network pharmacology, and molecular docking technology.

METHODS

The GEO database was used to obtain UC gene expression data. Then, differentially expressed genes were identified using R software. The active components of Myristicae Semen (Roudoukou), Aucklandiae Radix (Muxiang), and Coptidis Rhizoma (Huanglian) were searched by using the traditional Chinese medicine systems pharmacology database and analysis platform (TCMSP) database, and the corresponding targets were identified. The intersections of HMR and ulcerative colitis disease targets were obtained. The "drug-active ingredients-disease-target" network and protein-protein interaction (PPI) network were constructed to screen out the core components and targets using Cytoscape 3.9.1 software. Gene ontology (GO) and Kyoto encyclopedia of genes and genomes (KEGG) enrichment analyses were performed for the intersection targets by Metascapes database. Molecular docking between main active components and core targets was performed using AutoDock vina software.

RESULTS

A total of 967 differential genes were identified, and there were 29 active components and 163 active targets in UC. There were 24 active components in the "drug-active ingredients-disease-target" network, including quercetin, stigmasterol, berberine, beta-sitosterol, palmatine, and so on. There were 26 proteins in the PPI network, including interleukin-1β (IL-1β), interleukin-6 (IL-6), C-C motif chemokine 2 (CCL2), tumor necrosis factor (TNF), matrix metallopeptidase 9 (MMP9), and so on. GO enrichment analysis demonstrated that the intersection targets were mainly concentrated in biological processes such as lipopolysaccharide response, in cellular components such as external side of plasma membrane, and in molecular functions such as cytokine activity. KEGG analysis demonstrated that the intersection targets mainly involved the TNF signal pathway, nuclear factor kappa-B (NF-κB) pathway, Toll-like receptor (TLR) signal pathway, and so on. The results of molecular docking showed that the top five main active components had strong binding ability with the core targets IL-1β, IL-6, CCL2, TNF, and MMP9.

CONCLUSION

HMR may act on the expression of IL-1β, IL-6, CCL2, and other proteins through quercetin, stigmasterol, berberine, and other active components, regulate the TNF signaling pathway, and play a role in the treatment of UC via many mechanisms such as anti-inflammatory and intestinal immunity regulation.

Dermatologic Manifestations of Noninflammasome-Mediated Autoinflammatory Diseases

Autoinflammatory diseases (AIDs) arise from disturbances that alter interactions of immune cells and tissues. They give rise to prominent (auto)inflammation in the absence of aberrant autoantibodies and/or autoreactive T cells. AIDs that are predominantly caused by changes in the inflammasome pathways, such as the NLRP3- or pyrin-associated inflammasome, have gained substantial attention over the last years. However, AIDs resulting primarily from other changes in the defense system of the innate immune system are less well-studied. These noninflammasome-mediated AIDs relate to, for example, disturbance in the TNF or IFN signaling pathways or aberrations in genes affecting the IL-1RA. The spectrum of clinical signs and symptoms of these conditions is vast. Thus, recognizing early cutaneous signs constitutes an important step in differential diagnoses for dermatologists and other physicians. This review provides an overview of the pathogenesis, clinical presentation, and available treatment options highlighting dermatologic aspects of noninflammasome-mediated AIDs.

TNF-α interference ameliorates brain damage in neonatal hypoxic-ischemic encephalopathy rats by regulating the expression of NT-3 and TRKC

The aim of this study is to explore the effect of tumor necrosis factor-α (TNF-α) inhibition in rats with neonatal hypoxic-ischemic encephalopathy (HIE) and ascertain the relevant signaling pathways. The Zea-Longa score was used to evaluate the neurological function of the rats. ImageJ was used for quantification of the brain edema volume. Triphenyl tetrazolium chloride (TTC) staining of brain tissue was performed 24 h after hypoxic-ischemic (HI) to detect right brain infarction. The expression of TNF-α was detected by real-time quantitative polymerase chain reaction (RT-qPCR). Immunofluorescence staining was used to identify the localization of TNF-α; Then, the effective shRNA fragment of TNF-α was used to validate the role of TNF-α in HIE rats, and the change of neurotrofin-3 (NT-3) and tyrosine kinase receptor-C (TRKC) was examined after TNF-α-shRNA lentivirus transfection to determine downstream signaling associated with TNF-α. Protein interaction analysis was carried out to predict the links among TNF-α, NT-3, and TRKC. Cerebral edema volume and infarction increased in the right brain after the HI operation. The Zea-Longa score significantly increased within 24 h after the HI operation. The relative expression of TNF-α was upregulated after the HI operation. TNF-α was highly expressed in the right hippocampus post HI through immunofluorescence staining. Bioinformatics analysis found a direct or an indirect link among TNF-α, NT-3, and TRKC. Moreover, the interference of TNF-α increased the expression of NT-3 and TRKC. TNF-α interference might alleviate brain injury in HIE by upregulating NT-3 and TRKC.

Modulation of signaling cross-talk between pJNK and pAKT generates optimal apoptotic response

Tumor necrosis factor alpha (TNFα) is a well-known modulator of apoptosis by maintaining a balance between proliferation and cell-death in normal cells. Cancer cells often evade apoptotic response following TNFα stimulation by altering signaling cross-talks. Thus, varying the extent of signaling cross-talk could enable optimal TNFα mediated apoptotic dynamics. Herein, we use an experimental data-driven mathematical modeling to quantitate the extent of synergistic signaling cross-talk between the intracellular entities phosphorylated JNK (pJNK) and phosphorylated AKT (pAKT) that orchestrate the phenotypic apoptosis level by modulating the activated Caspase3 dynamics. Our study reveals that this modulation is orchestrated by the distinct dynamic nature of the synergism at early and late phases. We show that this synergism in signal flow is governed by branches originating from either TNFα receptor and NFκB, which facilitates signaling through survival pathways. We demonstrate that the experimentally quantified apoptosis levels semi-quantitatively correlates with the model simulated Caspase3 transients. Interestingly, perturbing pJNK and pAKT transient dynamics fine-tunes this accumulated Caspase3 guided apoptotic response. Thus, our study offers useful insights for identifying potential targeted therapies for optimal apoptotic response.

Optimizing study design in LPS challenge studies for quantifying drug induced inhibition of TNFα response: Did we miss the prime time?

In this work we evaluate the study design of LPS challenge experiments used for quantification of drug induced inhibition of TNFα response and provide general guidelines of how to improve the study design. Analysis of model simulated data, using a recently published TNFα turnover model, as well as the optimal design tool PopED have been used to find the optimal values of three key study design variables - time delay between drug and LPS administration, LPS dose, and sampling time points - that in turn could make the resulting TNFα response data more informative. Our findings suggest that the current rule of thumb for choosing the time delay should be reconsidered, and that the placement of the measurements after maximal TNFα response are crucial for the quality of the experiment. Furthermore, a literature study summarizing a wide range of published LPS challenge studies is provided, giving a broader perspective of how LPS challenge studies are usually conducted both in a preclinical and clinical setting.

Cell death in skin function, inflammation, and disease

Cell death is an essential process that plays a vital role in restoring and maintaining skin homeostasis. It supports recovery from acute injury and infection and regulates barrier function and immunity. Cell death can also provoke inflammatory responses. Loss of cell membrane integrity with lytic forms of cell death can incite inflammation due to the uncontrolled release of cell contents. Excessive or poorly regulated cell death is increasingly recognised as contributing to cutaneous inflammation. Therefore, drugs that inhibit cell death could be used therapeutically to treat certain inflammatory skin diseases. Programmes to develop such inhibitors are already underway. In this review, we outline the mechanisms of skin-associated cell death programmes; apoptosis, necroptosis, pyroptosis, NETosis, and the epidermal terminal differentiation programme, cornification. We discuss the evidence for their role in skin inflammation and disease and discuss therapeutic opportunities for targeting the cell death machinery.

The Screening of Therapeutic Peptides for Anti-Inflammation through Phage Display Technology

For the treatment of inflammatory illnesses such as rheumatoid arthritis and carditis, as well as cancer, several anti-inflammatory medications have been created over the years to lower the concentrations of inflammatory mediators in the body. Peptides are a class of medication with the advantages of weak immunogenicity and strong activity, and the phage display technique is an effective method for screening various therapeutic peptides, with a high affinity and selectivity, including anti-inflammation peptides. It enables the selection of high-affinity target-binding peptides from a complex pool of billions of peptides displayed on phages in a combinatorial library. In this review, we will discuss the regular process of using phage display technology to screen therapeutic peptides, and the peptides screened for anti-inflammation properties in recent years according to the target. We will describe how these peptides were screened and how they worked in vitro and in vivo. We will also discuss the current challenges and future outlook of using phage display to obtain anti-inflammatory therapeutic peptides.

Induced Pluripotent Stem Cell-Derived Monocytes/Macrophages in Autoinflammatory Diseases

The concept of autoinflammation, first proposed in 1999, refers to a seemingly unprovoked episode of sterile inflammation manifesting as unexplained fever, skin rashes, and arthralgia. Autoinflammatory diseases are caused mainly by hereditary abnormalities of innate immunity, without the production of autoantibodies or autoreactive T cells. The revolutionary discovery of induced pluripotent stem cells (iPSCs), whereby a patient’s somatic cells can be reprogrammed into an embryonic pluripotent state by forced expression of a defined set of transcription factors, has the transformative potential to enable in vitro disease modeling and drug candidate screening, as well as to provide a resource for cell replacement therapy. Recent reports demonstrate that recapitulating a disease phenotype in vitro is feasible for numerous monogenic diseases, including autoinflammatory diseases. In this review, we provide a comprehensive overview of current advances in research into autoinflammatory diseases involving iPSC-derived monocytes/macrophages. This review may aid in the planning of new studies of autoinflammatory diseases.

Screening of TNFR1 Binding Peptides from Deinagkistrodon acutus Venom through Phage Display

The venomous species Deinagkistrodon acutus has been used as anti-inflammatory medicine in China for a long time. It has been proven to have anti-inflammatory activity, but its specific anti-inflammatory components have not yet been fully elucidated. Tumor necrosis factor receptor-1 (TNFR1), which participates in important intracellular signaling pathways, mediates apoptosis, and functions as a regulator of inflammation, is often used as the target to develop anti-inflammatory drugs. The small peptides of snake venom have the advantages of weak immunogenicity and strong activity. To obtain the specific TNFR1 binding peptides, we constructed a T7 phage library of D. acutus venom glands, and then performed biopanning against TNFR1 on the constructed library. After biopanning three times, several sequences with potential binding capacity were obtained and one 41-amino acid peptide was selected through a series of biological analyses including sequence length, solubility, and simulated affinity, named DAvp-1. After synthesis, the binding capacity of DAvp-1 and TNFR1 was verified using surface plasmon resonance technology (SPR). Conclusively, by applying phage display technology, this work depicts the successful screening of a promising peptide DAvp-1 from D. acutus venom that binds to TNFR1. Additionally, our study emphasizes the usefulness of phage display technology for studies on screening natural product components.

Comprehensive Analysis of Immune Implication and Prognostic Value of IFI44L in Non-Small Cell Lung Cancer

Interferon-induced protein 44-like (IFI44L), a type I interferon-stimulated gene (ISG), has been reported to be involved in innate immune processes and to act as a tumor suppressor in several cancers. However, its immune implication on lung cancer remains unclear. Here, we systemically analyzed the immune association of IFI44L with multiple tumor-infiltrating immune cells (TIICs) and immunomodulators through bioinformatics methods in The Cancer Genome Atlas (TCGA) lung cancer cohorts. Then, the IFI44L-related immunomodulators were selected to construct the prognostic signatures in the lung adenocarcinoma (LUAD) cohort and the lung squamous cell carcinoma (LUSC) cohort, respectively. Concordance index and time-dependent receiver operating characteristics (ROC) curves were applied to evaluate the prognostic signatures. GSE72094 and GSE50081 were used to validate the TCGA-LUAD signature and TCGA-LUSC signature, respectively. A nomogram was established by risk score and clinical features in the LUAD cohort. Finally, the prognostic value and biological function of IFI44L were verified in a real-world cohort and in vitro experiments. The results indicated that IFI44L showed significant correlation with TIICs in LUAD and LUSC samples. Functional enrichment analysis showed that IFI44L may participate in various cancer/immune-related pathways, including JAK/STAT signaling pathway and NF-κB signaling pathway. A total of 44 immunomodulators presented obvious association with IFI44L in the TCGA-LUAD cohort and a robust 10-immunomodulator signature was constructed. Patients in the higher-risk group presented worse prognosis than those in the lower-risk group. Notably, the risk signature was successfully validated in GSE72094. Multivariate Cox regression suggested that the risk signature could act as independent prognostic factors in both TCGA-LUAD and GSE72094 cohorts. Besides, a 17-immunomodulator signature was established in the TCGA-LUSC cohort and similar results were presented through analysis. The nomogram exhibited good accuracy in predicting overall survival (OS) outcome among TCGA-LUAD patients than the risk signature and other clinical features, with the area under curve values being 0.782 at 1 year, 0.825 at 3 years, and 0.792 at 5 years. Finally, tissue microarray analysis indicated that higher expression of IFI44L presented opposite relationship with pathological stage (p = 0.016) and a better outcome among lung cancer patients (p = 0.024). Functional experiments found that IFI44L overexpression significantly inhibited the proliferation, migration, and invasion in LUAD and LUSC cells; RT-qPCR experiments verified the correlation between the expression level of IFI44L with multiple immunomodulators in SPC-A-1 and NCI-H520 cells. In conclusion, our research highlighted that IFI44L is associated with tumor immune infiltration and provided information on IFI44L's immune implication, which indicates that IFI44L has potential clinical immunotherapeutic value and the proposed nomogram is a promising biomarker for non-small cell lung cancer patients.

Myosin 1f-mediated activation of microglia contributes to the photoreceptor degeneration in a mouse model of retinal detachment

Photoreceptor death and neurodegeneration is the leading cause of irreversible vision loss. The inflammatory response of microglia plays an important role in the process of neurodegeneration. In this study, we chose retinal detachment as the model of photoreceptor degeneration. We found Myosin 1f was upregulated after retinal detachment, and it was specifically expressed in microglia. Deficiency of myosin 1f protected against photoreceptor apoptosis by inhibiting microglia activation. The elimination of microglia can abolish the protective effect of myosin 1f deficiency. After stimulation by LPS, microglia with myosin 1f deficiency showed downregulation of the MAPK and AKT pathways. Our results demonstrated that myosin 1f plays a crucial role in microglia-induced neuroinflammation after retinal injury and photoreceptor degeneration by regulating two classic inflammatory pathways and thereby decreasing the expression of inflammatory cytokines. Knockout of myosin 1f reduces the intensity of the immune response and prevents cell death of photoreceptor, suggesting that myosin 1f can be inhibited to prevent a decline in visual acuity after retinal detachment.

Hypoxic and Hyperoxic Breathing as a Complement to Low-Intensity Physical Exercise Programs: A Proof-of-Principle Study

Inflammation is an adaptive response to both external and internal stimuli including infection, trauma, surgery, ischemia-reperfusion, or malignancy. A number of studies indicate that physical activity is an effective means of reducing acute systemic and low-level inflammation occurring in different pathological conditions and in the recovery phase after disease. As a proof-of-principle, we hypothesized that low-intensity workout performed under modified oxygen supply would elicit a "metabolic exercise" inducing a hormetic response, increasing the metabolic load and oxidative stress with the same overall effect expected after a higher intensity or charge exercise. Herein, we report the effect of a 5-week low-intensity, non-training, exercise program in a group of young healthy subjects in combination with the exposure to hyperoxia (30% and 100% pO₂, respectively) or light hypoxia (15% pO₂) during workout sessions on several inflammation and oxidative stress parameters, namely hemoglobin (Hb), redox state, nitric oxide metabolite (NOx), inducible nitric oxide synthase (iNOS), inflammatory cytokine expression (TNF-α, interleukin (IL)-6, IL-10), and renal functional biomarkers (creatinine, neopterin, and urates). We confirmed our previous reports demonstrating that intermittent hyperoxia induces the normobaric oxygen paradox (NOP), a response overlapping the exposure to hypoxia. Our data also suggest that the administration of modified air composition is an expedient complement to a light physical exercise program to achieve a significant modulation of inflammatory and immune parameters, including cytokines expression, iNOS activity, and oxidative stress parameters. This strategy can be of pivotal interest in all those conditions characterized by the inability to achieve a sufficient workload intensity, such as severe cardiovascular alterations and articular injuries failing to effectively gain a significant improvement of physical capacity.

The immunological significance of tumor necrosis factor receptor-associated factors (TRAFs)

The tumor necrosis factor receptor (TNFR)-associated factor (TRAF) family of molecules are intracellular signaling adaptors and control diverse signaling pathways mediated not only by the TNFR superfamily and the Toll-like receptor/interleukin-1 receptor superfamily but also by unconventional cytokine receptors such as IL-6 and IL-17 receptors. There are seven family members, TRAF1 to TRAF7, in mammals. Exaggerated immune responses induced through TRAF signaling downstream of these receptors often lead to inflammatory and autoimmune diseases including rheumatoid arthritis, inflammatory bowel disease, psoriasis and autoinflammatory syndromes, and thus those signals are major targets for therapeutic intervention. For this reason, it has been very important to understand signaling mechanisms regulated by TRAFs that greatly impact on life/death decisions and the activation, differentiation and survival of cells of the innate and adaptive immune systems. Accumulating evidence suggests that dysregulated cellular expression and/or signaling of TRAFs causes overproduction of proinflammatory cytokines, which facilitates aberrant activation of immune cells. In this review, I will explain the structural and functional aspects that are responsible for the cellular activity and disease outcomes of TRAFs, and summarize the findings of recent studies on TRAFs in terms of how individual TRAF family molecules regulates biological and disease processes in the body in both positive and negative ways. This review also discusses how TRAF mutations contribute to human disease.

Wolfberry-derived zeaxanthin dipalmitate delays retinal degeneration in a mouse model of retinitis pigmentosa through modulating STAT3, CCL2 and MAPK pathways

Retinitis pigmentosa (RP) is a group of inherited photoreceptor degeneration diseases that causes blindness without effective treatment. The pathogenesis of retinal degeneration involves mainly oxidative stress and inflammatory responses. Zeaxanthin dipalmitate (ZD), a wolfberry-derived carotenoid, has anti-inflammatory and anti-oxidative stress effects. Here we investigated whether these properties of ZD can delay the retinal degeneration in rd10 mice, a model of RP, and explored its underlying mechanism. One shot of ZD or control vehicle was intravitreally injected into rd10 mice on postnatal day 16 (P16). Retinal function and structure of rd10 mice were assessed at P25, when rods degenerate substantially, using a visual behavior test, multi-electrode-array recordings and immunostaining. Retinal pathogenic gene expression and regulation of signaling pathways by ZD were explored using transcriptome sequencing and western blotting. Our results showed that ZD treatment improved the visual behavior of rd10 mice and delayed the degeneration of retinal photoreceptors. It also improved the light responses of photoreceptors, bipolar cells and retinal ganglion cells. The expression of genes that are involved in inflammation, apoptosis and oxidative stress were up-regulated in rd10 mice, and were reduced by ZD. ZD further reduced the activation of two key factors, signal transducer and activator of transcription 3 and chemokine (C-C motif) ligand 2, down-regulated the expression of the inflammatory factor GFAP, and inhibited extracellular signal regulated protein kinases and P38, but not the JNK pathways. In conclusion, ZD delays the degeneration of the rd10 retina both morphologically and functionally. Its anti-inflammatory function is mediated primarily through the signal transducer and activator of transcription 3, chemokine (C-C motif) ligand 2 and MAPK pathways. Thus, ZD may serve as a potential clinical candidate to treat RP.

A trivalent TNF-R2 as a new tumor necrosis factor alpha-blocking molecule

The neutralization of tumor necrosis factor alpha (TNFα) with biopharmaceuticals is a successful therapy for inflammatory diseases. Currently, one of the main TNFα-antagonists is Etanercept, a dimeric TNF-R2 ectodomain. Considering that TNFα and its receptors are homotrimers, we proposed that a trimeric TNF-R2 ectodomain could be an innovative TNFα-antagonist. Here, the 3cTNFR2 protein was designed by the fusion of the TNF-R2 ectodomain with the collagen XV trimerization domain. 3cTNFR2 was produced in HEK293 cells and purified by immobilized metal affinity chromatography. Monomers, dimers, and trimers of 3cTNFR2 were detected. The interaction 3cTNFR2-TNFα was assessed. By microscale thermophoresis, the K_D value for the interaction was 4.17 ± 0.88 nM, and complexes with different molecular weights were detected by size exclusion chromatography-high performance liquid chromatography. Moreover, 3cTNFR2 neutralized the TNFα-induced cytotoxicity totally in vitro. Although more studies are required to evaluate the anti-inflammatory effect, the results suggest that 3cTNFR2 could be a TNFα-antagonist agent.

Prediction and Verification of the Major Ingredients and Molecular Targets of Tripterygii Radix Against Rheumatoid Arthritis

Tripterygii Radix exhibits good clinical efficacy and safety in rheumatoid arthritis (RA) patients, but its effective components and mechanism of action are still unclear. The purpose of this study was to explore and verify the major ingredients and molecular targets of Tripterygii Radix in RA using drug-compounds-biotargets-diseases network and protein-protein interaction (PPI) network analyses. The processes and pathways were derived from Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway enrichment analyses. The most important compounds and biotargets were determined based on the degree values. RA fibroblast-like synoviocytes (RA-FLS) were separated from RA patients and identified by hematoxylin and eosin (HE) staining and immunohistochemistry. The purity of RA-FLS was acquired by flow cytometry marked with CD90 or VCAM-1. RA-FLS were subjected to control, dimethyl sulfoxide (control), kaempferol, or lenalidomide treatment. Cell migration was evaluated by the transwell assay. The relative expression of biotarget proteins and cytokines was analyzed by western blotting and flow cytometry. In total, 144 chemical components were identified from Tripterygii Radix; kaempferol was the most active ingredient among 33 other components. Fourteen proteins were found to be affected in RA from 285 common biotargets. The tumor necrosis factor (TNF) signaling pathway was predicted to be one of the most latent treatment pathways. Migration of RA-FLS was inhibited and the expression of protein kinase B (AKT1), JUN, caspase 3 (CASP3), TNF receptor 1 and 2 (TNFR1 and TNFR2), interleukin-6 (IL-6), and TNF-α was significantly affected by kaempferol. Thus, this study confirmed kaempferol as the effective component of Tripterygii Radix against RA-FLS and TNF signaling pathway and its involvement in the regulation of AKT1, JUN, CASP3, TNFR1, TNFR2, IL-6, and TNF-α expression.

Clinical characteristics and genetic analysis of A20 haploinsufficiency

PURPOSE

To evaluate the clinical and genetic characteristics of 3 children with Haploinsufficiency of A20 (HA20).

METHODS

The clinical and genetic testing data of 3 children with HA20 treated at Capital Institute of Pediatrics (CIP) between August 2016 and October 2019 were retrospectively analysed.

RESULT

Patient 1 presented with arthritis and inflammatory bowel disease, patient 2 presented with axial spinal arthritis and lupus-like syndrome, and patient 3 presented with recurrent oral ulcers, gastrointestinal ulcers, and perianal abscesses. Regarding laboratory tests, patients were found to have elevated white blood cell (WBC) count, C-reactive protein (CRP) and erythrocyte sedimentation rate (ESR). The CRP and ESR was reported to be high in all the patients. The WBC was reported to be high in patient 1 and 3. Patient 2 was positive for antinuclear antibodies, anti-Sjögren's syndrome antigen A, dsDNA, rheumatoid factor and Coombs test. Genetic testing showed that all three patients had heterozygous mutation in TNFAIP3 gene. As for the treatment, patient 1 was treated with TNFα antagonist, patient 2 was treated with TNF α antagonist and sulfasalazine, and patient 3 was treated with corticosteroids and thalidomide. Patients 1 and 2 were followed for four and 3 months, respectively. There was an improvement in joint and gastrointestinal symptoms; inflammatory indices and rheumatoid factor (RF) were normal, and dsDNA and Coombs test became negative. Patient 3 was treated at another hospital and showed gradual improvement in oral ulcers and perianal abscesses.

CONCLUSION

HA20 is a single-gene auto-inflammatory disease caused by mutation in tumour necrosis factor (TNF)-α-induced protein 3 (TNFAIP3) gene. It may present as Behçet-like syndrome and resemble various other autoimmune diseases as well. Corticosteroids and immunosuppressive agents are effective treatments, and cytokine antagonists can be used in refractory cases. Whole-exome genetic testing should be proactively performed for children with early-age onset or Behçet-like syndrome to achieve early diagnosis and accurate treatment.

Tumor necrosis factor in lung cancer: Complex roles in biology and resistance to treatment

Tumor necrosis factor (TNF) and its receptors are widely expressed in non-small cell lung cancer (NSCLC). TNF has an established role in inflammation and also plays a key role in inflammation-induced cancer. TNF can induce cell death in cancer cells and has been used as a treatment in certain types of cancer. However, TNF is likely to play an oncogenic role in multiple types of cancer, including NSCLC. TNF is a key activator of the transcription factor NF-κB. NF-κB, in turn, is a key effector of TNF in inflammation-induced cancer. Data from The Cancer Genome Atlas database suggest that TNF could be a biomarker in NSCLC and indicate a complex role for TNF and its receptors in NSCLC. Recent studies have reported that TNF is rapidly upregulated in NSCLC in response to targeted treatment with epidermal growth factor receptor (EGFR) inhibition, and this upregulation leads to NF-κB activation. The TNF upregulation and consequent NF-κB activation play a key role in mediating both primary and secondary resistance to EGFR inhibition in NSCLC, and a combined inhibition of EGFR and TNF can overcome therapeutic resistance in experimental models. TNF may mediate the toxic side effects of immunotherapy and may also modulate resistance to immune checkpoint inhibitors. Drugs inhibiting TNF are widely used for the treatment of various inflammatory and rheumatologic diseases and could be quite useful in combination with targeted therapy of NSCLC and other cancers.

USP2-Related Cellular Signaling and Consequent Pathophysiological Outcomes

Ubiquitin specific protease (USP) 2 is a multifunctional deubiquitinating enzyme. USP2 modulates cell cycle progression, and therefore carcinogenesis, via the deubiquitination of cyclins and Aurora-A. Other tumorigenic molecules, including epidermal growth factor and fatty acid synthase, are also targets for USP2. USP2 additionally prevents p53 signaling. On the other hand, USP2 functions as a key component of the CLOCK/BMAL1 complex and participates in rhythmic gene expression in the suprachiasmatic nucleus and liver. USP2 variants influence energy metabolism by controlling hepatic gluconeogenesis, hepatic cholesterol uptake, adipose tissue inflammation, and subsequent systemic insulin sensitivity. USP2 also has the potential to promote surface expression of ion channels in renal and intestinal epithelial cells. In addition to modifying the production of cytokines in immune cells, USP2 also modulates the signaling molecules that are involved in cytokine signaling in the target cells. Usp2 knockout mice exhibit changes in locomotion and male fertility, which suggest roles for USP2 in the central nervous system and male genital tract, respectively. In this review, we summarize the cellular events with USP2 contributions and list the signaling molecules that are upstream or downstream of USP2. Additionally, we describe phenotypic differences found in the in vitro and in vivo experimental models.

Tumor Necrosis Factor Receptors: Pleiotropic Signaling Complexes and Their Differential Effects

Since its discovery in 1975, TNFα has been a subject of intense study as it plays significant roles in both immunity and cancer. Such attention is well deserved as TNFα is unique in its engagement of pleiotropic signaling via its two receptors: TNFR1 and TNFR2. Extensive research has yielded mechanistic insights into how a single cytokine can provoke a disparate range of cellular responses, from proliferation and survival to apoptosis and necrosis. Understanding the intracellular signaling pathways induced by this single cytokine via its two receptors is key to further revelation of its exact functions in the many disease states and immune responses in which it plays a role. In this review, we describe the signaling complexes formed by TNFR1 and TNFR2 that lead to each potential cellular response, namely, canonical and non-canonical NF-κB activation, apoptosis and necrosis. This is followed by a discussion of data from in vivo mouse and human studies to examine the differential impacts of TNFR1 versus TNFR2 signaling.

TNF Is Partially Required for Cell-Death-Triggered Skin Inflammation upon Acute Loss of cFLIP

cFLIP is required for epidermal integrity and skin inflammation silencing via protection from TNF-induced keratinocyte apoptosis. Here, we generated and analyzed cFLIP epidermal KO mice with additional TNF deficiency. Intriguingly, the ablation of TNF rescued the pathological phenotype of epidermal cFLIP KO from characteristic weight loss and increased mortality. Moreover, the lack of TNF in these animals strongly reduced and delayed the epidermal hyperkeratosis and the increased apoptosis in keratinocytes. Our data demonstrate that TNF signaling in cFLIP-deficient keratinocytes is the critical factor for the regulation of skin inflammation via modulated cytokine and chemokine expression and, thus, the attraction of immune cells. Our data suggest that autocrine TNF loop activation upon cFLIP deletion is dispensable for T cells, but is critical for neutrophil attraction. Our findings provide evidence for a negative regulatory role of cFLIP for TNF-dependent apoptosis and partially for epidermal inflammation. However, alternative signaling pathways may contribute to the development of the dramatic skin disease upon cFLIP deletion. Our data warrant future studies of the regulatory mechanism controlling the development of skin disease upon cFLIP deficiency and the role of cFLIP/TNF in a number of inflammatory skin diseases, including toxic epidermal necrolysis (TEN).

Improvement of Certolizumab Fab' properties by PASylation technology

Certolizumab pegol is a Fab' antibody fragment for treatment of rheumatoid arthritis and Crohn's disease which is conjugated to a 40 kDa PEG molecule in order to increase the protein half-life. PEGylation may have disadvantages including immunogenicity, hypersensitivity, vacuolation, decreased binding affinity and biological activity of the protein. To overcome these problems, PASylation has been developed as a new approach. The nucleotide sequence encoding 400 amino acid PAS residues was genetically fused to the corresponding nucleotide sequences of both chains of certolizumab. Then, the bioactivity as well as physicochemical and pharmacokinetic properties of the recombinant PASylated expressed protein was assayed. Circular dichroism spectroscopy demonstrated that the random coil structure of PAS sequences did not change the secondary structure of the PASylated Fab' molecule. It was observed that PASylation influenced the properties of the Fab' molecule by which the hydrodynamic radius and neutralization activity were increased. Also, the antigen binding and binding kinetic parameters improved in comparison to the PEGylated Fab' antibody. Pharmacokinetic studies also showed prolonged terminal half-life and improved pharmacokinetic parameters in PASylated recombinant protein in comparison to the PEGylated and Fab' control molecules. The results reconfirmed the efficiency of PASylation approach as a potential alternative method in increasing the half-life of pharmaceutical proteins.

Systemic autoinflammatory diseases: Clinical state of the art

Systemic autoinflammatory diseases (SAIDs) are defined as disorders of innate immunity. They were initially defined in opposition to autoimmune diseases due to the lack of involvement of the adaptive immune system and circulating autoantibodies. The four historical monogenic diseases are familial Mediterranean fever (associated with MEFV mutations), cryopyrinopathies (NLRP3 mutations), tumor necrosis factor receptor-associated periodic syndrome (TNFRSF1A mutations), and mevalonate kinase deficiency (MVK mutations). In the last 10 years, more than 50 new monogenic SAIDs have been discovered thanks to advances in genetics. Diagnosis is largely based on personal and family history and detailed analysis of signs and symptoms associated with febrile attacks, in the setting of elevated inflammatory markers. Increasingly efficient techniques of genetic analysis can contribute to refining the diagnosis. This review is a guide for the clinician in suspecting and establishing a diagnosis of SAID.

Quantitative single-molecule imaging of TNFR1 reveals zafirlukast as antagonist of TNFR1 clustering and TNFα-induced NF-ĸB signaling

TNFR1 is a crucial regulator of NF-ĸB-mediated proinflammatory cell survival responses and programmed cell death (PCD). Deregulation of TNFα- and TNFR1-controlled NF-ĸB signaling underlies major diseases, like cancer, inflammation, and autoimmune diseases. Therefore, although being routinely used, antagonists of TNFα might also affect TNFR2-mediated processes, so that alternative approaches to directly antagonize TNFR1 are beneficial. Here, we apply quantitative single-molecule localization microscopy (SMLM) of TNFR1 in physiologic cellular settings to validate and characterize TNFR1 inhibitory substances, exemplified by the recently described TNFR1 antagonist zafirlukast. Treatment of TNFR1-mEos2 reconstituted TNFR1/2 knockout mouse embryonic fibroblasts (MEFs) with zafirlukast inhibited both ligand-independent preligand assembly domain (PLAD)-mediated TNFR1 dimerization as well as TNFα-induced TNFR1 oligomerization. In addition, zafirlukast-mediated inhibition of TNFR1 clustering was accompanied by deregulation of acute and prolonged NF-ĸB signaling in reconstituted TNFR1-mEos2 MEFs and human cervical carcinoma cells. These findings reveal the necessity of PLAD-mediated, ligand-independent TNFR1 dimerization for NF-ĸB activation, highlight the PLAD as central regulator of TNFα-induced TNFR1 oligomerization, and demonstrate that TNFR1-mEos2 MEFs can be used to investigate TNFR1-antagonizing compounds employing single-molecule quantification and functional NF-ĸB assays at physiologic conditions.

Innate Lymphocyte Mechanisms in Skin Diseases

Innate lymphocyte populations are emerging as key effectors in tissue homeostasis, microbial defense, and inflammatory skin disease. The cells are evolutionarily ancient and carry conserved principles of function, which can be achieved through shared or unique specific mechanisms. Recent technological and treatment advances have provided insight into heterogeneity within and between individuals and species. Similar pathways can extend through to adaptive lymphocytes, which softens the margins with innate lymphocyte populations and allows investigation of nonredundant pathways of immunity and inflammation that might be amenable to therapeutic intervention. Here, we review advances in understanding of innate lymphocyte biology with a focus on skin disease and the roles of commensal and pathogen responses and tissue homeostasis.

Moving towards a systems-based classification of innate immune-mediated diseases

Autoinflammation as a distinct disease category was first reported in 1999 as a group of monogenic disorders characterized by recurrent episodes of systemic and organ-specific inflammation, known as periodic fever syndromes. Since this original description, the focus has shifted considerably to the inclusion of complex multifactorial conditions with an autoinflammatory basis. Furthermore, the boundaries of what are considered to be autoinflammatory disorders are constantly evolving and currently encompass elements of immunodeficiency and autoimmunity. Notable developments in the intervening 20 years include substantial progress in understanding how the different inflammasomes are activated, how infection is sensed by the innate immune system and how intracellular signalling systems are consequently activated and integrated with many different cellular functions in the autoinflammatory process. With these developments, the field of autoinflammation is moving from a gene-centric view of innate immune-mediated disease towards a systems-based concept, which describes how various convergent pathways, including pyrin and the actin cytoskeleton, protein misfolding and cellular stress, NF-κB dysregulation and interferon activation, contribute to the autoinflammatory process. The development and adoption of a systems-based concept of systemic autoinflammatory diseases is anticipated to have implications for the development of treatments that target specific components of the innate immune system.

Haploinsufficiency of A20 with a novel mutation of deletion of exons 2-3 of TNFAIP3

OBJECTIVES

Haploinsufficiency of A20 (HA20) due to loss-of-function mutations of TNFAIP3 leads to an autoinflammatory disease. These mutations produce a premature termination codon in most cases of HA20. However, exon deletion has not been reported.

METHODS

Genomic DNA was extracted from the peripheral blood of the patient clinically suspected of HA20. We examined autoinflammatory disease-causing genes and performed a multiplex ligation-dependent probe amplification (MLPA) assay for copy number analysis. Next, to determine the disconnection point, genomic DNA was amplified with long-range PCR and sequenced. Finally, western blotting was carried out to measure A20 protein expression in mitogen phytohaemagglutinin (PHA)-induced T-cell blasts from the patient and a healthy volunteer.

RESULTS

Targeted next-generation sequencing found no pathogenic mutation, but copy number variation (CNV) analysis suggested a heterozygous deletion of exons 2-3. The MLPA assay and long-range PCR confirmed the mutation. Western blotting analysis indicated a marked decrease in expression of A20 protein from the patient compared to a normal control. The results showed that this deletion was a pathogenic mutation.

CONCLUSION

This study demonstrates a novel mutation resulting in a deletion of exons 2-3 of TNFAIP3. MLPA analysis is a useful initial screening method for HA20 patients.

Single-molecule imaging reveals the oligomeric state of functional TNFα-induced plasma membrane TNFR1 clusters in cells

Ligand-induced tumor necrosis factor receptor 1 (TNFR1) activation controls nuclear factor κ-light-chain-enhancer of activated B cells (NF-κB) signaling, cell proliferation, programmed cell death, and survival and is crucially involved in inflammation, autoimmune disorders, and cancer progression. Despite the relevance of TNFR1 clustering for signaling, oligomerization of ligand-free and ligand-activated TNFR1 remains controversial. At present, models range from ligand-independent receptor predimerization to ligand-induced oligomerization. Here, we used quantitative, single-molecule superresolution microscopy to study TNFR1 assembly directly in native cellular settings and at physiological cell surface abundance. In the absence of its ligand TNFα, TNFR1 assembled into monomeric and dimeric receptor units. Upon binding of TNFα, TNFR1 clustered predominantly not only into trimers but also into higher-order oligomers. A functional mutation in the preligand assembly domain of TNFR1 resulted in only monomeric TNFR1, which exhibited impaired ligand binding. In contrast, a form of TNFR1 with a mutation in the ligand-binding CRD2 subdomain retained the monomer-to-dimer ratio of the unliganded wild-type TNFR1 but exhibited no ligand binding. These results underscore the importance of ligand-independent TNFR1 dimerization in NF-κB signaling.

Functional analysis of a novel G87V TNFRSF1A mutation in patients with TNF receptor-associated periodic syndrome

Tumor necrosis factor (TNF) receptor-associated periodic syndrome (TRAPS) is an autoinflammatory disease that is caused by heterozygous mutations in the TNFRSF1A gene. Although more than 150 TNFRSF1A mutations have been reported to be associated with TRAPS phenotypes only a few, such as p.Thr79Met (T79M) and cysteine mutations, have been functionally analyzed. We identified two TRAPS patients in one family harboring a novel p.Gly87Val (G87V) mutation in addition to a p.Thr90Ile (T90I) mutation in TNFRSF1A. In this study, we examined the functional features of this novel G87V mutation. In-vitro analyses using mutant TNF receptor 1 (TNF-R1)-over-expressing cells demonstrated that this mutation alters the expression and function of TNF-R1 similar to that with the previously identified pathogenic T79M mutation. Specifically, cell surface expression of the mutant TNF-R1 in transfected cells was inhibited with both G87V and T79M mutations, whereas the T90I mutation did not affect this. Moreover, peripheral blood mononuclear cells (PBMCs) from TRAPS patients harboring the G87V and T90I mutations showed increased mitochondrial reactive oxygen species (ROS). Furthermore, the effect of various Toll-like receptor (TLR) ligands on inflammatory responses was explored, revealing that PBMCs from TRAPS patients are hyper-responsive to TLR-2 and TLR-4 ligands and that interleukin (IL)-8 and granulocyte-macrophage colony-stimulating factor (GM-CSF) are likely to be involved in the pathogenesis of TRAPS. These findings suggest that the newly identified G87V mutation is one of the causative mutations of TRAPS. Our findings based on unique TRAPS-associated mutations provide novel insight for clearer understanding of inflammatory responses, which would be basic findings of developing a new therapeutic and prophylactic approach to TRAPS.