TNF-α Receptor Research Articles

Chronic inflammation deters natural killer cell fitness and cytotoxicity in myeloid leukemia

AbstractNatural killer (NK) cells play an integral role in immunosurveillance against myeloid malignancies, with their mature phenotype and abundance linked to prolonged treatment-free remission in chronic myeloid leukemia (CML). However, NK cell function is suppressed during the disease, and the orchestrators of this impairment are not fully understood. Using a chimeric BCR::ABL1+ CML mouse model, we characterized the impact of the leukemic microenvironment on NK cell function. We showed that NK cells have reduced counts, immature phenotype, poor cytotoxicity, and altered expression of activating and inhibitory receptors in CML mice, which revert to a steady state upon BCR::ABL1 inhibition. Single-cell RNA sequencing revealed an inflammatory cytokine response in CML-exposed NK cells, highlighted by the tumor necrosis factor α (TNFα)-induced gene signature, upregulation of TNFα receptor 2, and enrichment of SOCS family genes such as Cish, the critical NK cell checkpoint. Ex vivo exposure of healthy NK cells to leukemic soluble factors compromised target-specific NK cell degranulation, which was partially rescued by targeting Cish or TNFα. In alignment with these findings, NK cells from healthy donors displayed suppressed cytotoxicity when exposed to plasma from untreated patients with CML, with a partial restoration upon Cish or TNFα inhibition. Furthermore, NK cells from newly diagnosed patients with CML predestined for blast crisis showed an enrichment of the TNFα-induced proinflammatory gene signature identified in CML mice. These results suggest that targeting inflammatory signaling could enhance NK cell-based immunotherapies for CML.

Expression of NLRP3 in serum and induced sputum of children with asthma and their relationship with disease severity

ObjectivesThe aim of this cross-sectional study is to investigate the levels of NLRP3 in the serum and induced sputum of children with asthma and their potential association with lung function and disease severity.MethodsThis cross-sectional study included 83 children with bronchial asthma who sought medical care at our hospital from May 2023 to February 2024. Portable spirometry was used to monitor lung function parameters, including forced vital capacity, forced expiratory volume in 1 s, peak expiratory flow. The expression of C-reactive protein (CRP), interleukin (IL)-6, IL-1β, TNF-α, and Nod-like receptor family pyrin domain-containing 3 (NLRP3) in the serum and induced sputum were measured by enzyme-linked immunosorbent assay. Data analysis was performed using SPSS 25.0 and differences with P < 0.05 were considered statistically significant.ResultsChildren with asthma exhibited significantly elevated levels of serum NLRP3, CRP, IL-6, IL-1β, and TNF-α compared to healthy controls. In addition, children with moderate–severe asthma had significantly higher levels of serum and induced sputum NLRP3 and IL-1β compared to children with mild asthma. Spearman’s correlation analysis revealed a positive correlation between induced sputum NLRP3 and IL-6. Moreover, induced sputum NLRP3 was negatively correlated with lung function parameters. The results of receiver operating characteristic curves showed that induced sputum NLRP3 could be used for diagnosing children with moderate–severe asthma, with an AUC was 0.758, cutoff value of 3.33 ng/mL, sensitivity of 66.1%, and specificity of 70.8%. Furthermore, the logistic regression analysis revealed that serum and induced sputum NLRP3, induced sputum IL-6 and IL-1β were risk factors for children with moderate–severe asthma.ConclusionsIn this cross-sectional study, we found a significant increase in NLRP3 levels in induced sputum of children with asthma, which further increased in those with moderate–severe disease. The levels of NLRP3 in induced sputum could serve as potential biomarkers for assessing disease severity.

Lysimachia mauritiana Lam. Extract Alleviates Airway Inflammation Induced by Particulate Matter Plus Diesel Exhaust Particles in Mice.

The respiratory-protective effects of Lysimachia mauritiana (LM) against airway inflammation were evaluated in a mouse model exposed to a fine dust mixture of diesel exhaust particles and particulate matter with a diameter of less than 10 µm (PM10D). To induce airway inflammation, PM10D was intranasally injected into BALB/c mice three times a day for 12 days, and LM extracts were given orally once per day. The immune cell subtypes, histopathology, and expression of inflammatory mediators were analyzed from the bronchoalveolar lavage fluid (BALF) and lungs. LM alleviated the accumulation of neutrophils and the number of inflammatory cells in the lungs and the BALF of the PM10D-exposed mice. LM also reduced the release of inflammatory mediators (MIP-2, IL-17, IL-1α, CXCL1, TNF-α, MUC5AC, and TRP receptor channels) in the BALF and lungs. Lung histopathology was used to examine airway inflammation and the accumulation of collagen fibers and inflammatory cells after PM10D exposure and showed that LM administration improved this inflammation. Furthermore, LM extract inhibited the MAPK and NF-κB signaling pathway in the lungs and improved expectoration activity through an increase in phenol red release from the trachea. LM alleviated PM10D-exposed neutrophilic airway inflammation by suppressing MAPK/NF-κB activation. This study indicates that LM extract may be an effective therapeutic agent against inflammatory respiratory diseases.

Protective effect of Tecoma stans (L.) Juss.ex Kunth in CFA-induced arthritic rats

Ethnopharmacological relevanceTecoma stans (L.) Juss.ex Kunth (Bignoniaceae) is mainly found in tropical and subtropical regions of Africa and Asia. The leaves, flowers, roots, and bark are used to treat various aliments includes, skin infections, kidney problems, intestinal disorders, jaundice, toothaches, joint pain and repair cracked bones, antidotes for snake, scorpion, and rat bites. Aim of the studyThe objective of the study is to assess the anti-arthritic properties of T. stans leaf using Complete Freund's adjuvant (CFA)-induced rat. Materials and methodThe ethanol extract of T. stans leaf (ETSL) was subjected toGas Chromatography-Mass Spectrometry (GC-MS) and Liquid Chromatography-Mass Spectrometry (LC-MS) analysis for the identification of potential bioactive. The anti-arthritic activity was carried out by administering CFA (0.1 ml) into the sub-plantar surface of the right hind paw. The experimental animals were treated with indomethacin (10 mg/kg) and ETSL (250, 500 mg/kg) once a day orally for fourteen days. The arthritic parameters and hematological and biochemical parameters were evaluated using standard kit reagents. The levels of pro-inflammatory cytokines and inflammatory mediators were measured in blood serum. Antioxidant parameters were assessed in homogenized liver and joint tissues. Radiological and histopathological analysis of joint was performed. A computational molecular docking investigation of the phytoconstituents was conducted against COX-2, IL-1β, IL-6, and TNF-α receptors. ResultsThe ETSL at 500 mg/kg demonstrated significant (p < 0.01) restoration of arthritic parameters, hematological and biochemical indices and oxidative stress in CFA-induced rats which was further supported by radiological histological examination. In addition, there was significant (p < 0.05) reduction observed in pro-inflammatory cytokines, inflammatory mediators and up-regulation of anti-inflammatory cytokines in the treated group. Verbascoside was found to exhibit better biding affinities −10.4, −7.4, −7 and −6.2 kcal/mol against COX-2, IL-1β, TNF-α, and IL-6 respectively, confirmed through in silico study. ConclusionsThe observed outcome suggests that ETSL at a dosage of 500 mg/kg demonstrated notable anti-arthritic effects by suppressing pro-inflammatory cytokines and oxidative stress biomarkers. This effect could potentially be attributed to the presence of bioactive verbascoside identified in the LC-MS analysis.

Tumor Necrosis Factor Receptors and C-C Chemokine Receptor-2 Positive Cells Play an Important Role in the Intraerythrocytic Death and Clearance of Babesia microti.

Babesia microti is an Apicomplexan parasite that infects erythrocytes and causes the tick-transmitted infection, babesiosis. B. microti can cause a wide variety of clinical manifestations ranging from asymptomatic to severe infection and death. Some risk factors for severe disease are well-defined, an immune compromised state, age greater than 50, and asplenia. However, increasing cases of severe disease and hospitalization in otherwise healthy individuals suggests that there are unknown risk factors. The immunopathology of babesiosis is poorly described. CD4+ T cells and the spleen both play a critical role in parasite clearance, but few other factors have been found that significantly impact the course of disease. Here, we evaluated the role of several immune mediators in B. microti infection. Mice lacking TNF receptors 1 and 2, the receptors for TNFα and LTα, had a higher peak parasitemia, reduced parasite killing in infected red blood cells (iRBCs), and delayed parasite clearance compared to control mice. Mice lacking CCR2, a chemokine receptor involved in the recruitment of inflammatory monocytes, and mice lacking NADPH oxidase, which generates superoxide radicals, demonstrated reduced parasite killing but had little effect on the course of parasitemia. These results suggest that TNFR-mediated responses play an important role in limiting parasite growth, the death of parasites in iRBCs, and the clearance of iRBCs, and that the parasite killing in iRBCs is being primarily mediated by ROS and inflammatory monocytes/macrophages. By identifying factors involved in parasite killing and clearance, we can begin to identify additional risk factors for severe infection and newer therapeutic interventions.

Anti-inflammatory and anticancer activities of boron nitride nanotubes functionalized with curcumin: Density functional theory and molecular docking studies

Boron nitride (BN) nanotubes have emerged as promising carrier options for drug delivery systems. This study investigates the loading of curcumin (CUR) in various states onto the surface of a zigzag (8, 0) boron nitride nanotube, which consists of 8 unit cells, has a diameter of approximately 6.66 Å, and a length of approximately 20 Å, in order to enhance its solubility and stability. The assessment utilizes density functional theory (DFT) methods with the PBE1-D functional and 6-311G** basis set in a solvent (water) phase. It was found that the CUR, via its carbonyl group in compound A (−1.37 eV), can be electrostatically interact with the center of BNNT surface compared to compound B (−0.84 eV) and compound C (−1.12 eV). During the adsorption process, compound A exhibited the highest increase in dipole moment, with a value of 16.84 Debye, followed by compound C with 15.99 Debye, and compound B with 13.03 Debye, suggesting enhanced solubility of the system. The results indicate that the hardness, softness, and electrophilicity values of compounds A, B, and C decrease upon CUR adsorption, implying that CUR enhances the reactivity of BNNT. Additionally, the conductivity of the BNNT is affected by changes in the energy gap when CUR is adsorbed onto the outer surface of the nanotube. The molecular docking results of the TNF-α receptor revealed that complex B exhibited the lowest binding energy (−10.8 kcal/mol) and optimal orientations toward the receptor, suggesting a strong binding affinity. Conversely, complex C (−10.1 kcal/mol) demonstrated significant binding affinity to the NF-KB target, indicating its potential as an effective NF-KB inhibitor. Therefore, BNNTs could serve as templates for the design and synthesis of innovative anti-inflammatory agents with potent anticancer properties.

The intervention mechanism of Tanshinone IIA in alleviating neuronal injury induced by HMGB1 or TNF-α-mediated microglial activation

Tanshinone IIA (Tan IIA), a neuroprotective natural compound extracted from Salvia miltiorrhiza, is used in stroke treatment. However, elucidating Tan IIA's neuroprotective mechanisms remains challenging due to limitations in assessing drug efficacy and biochemical parameters in clinical studies. This study investigated Tan IIA's impact on neuroinflammatory responses and its neuroprotective mechanisms using HMGB1- or TNF-α-stimulated BV2 microglia in a co-culture system with primary neuron cells. The results indicated that Tan IIA significantly reduced microglial activation induced by TNF-α or HMGB1. Concurrently, Tan IIA disrupted the interactions between HMGB1 and toll-like receptor 4 (TLR4), and between TNF-α and TNF receptor 1 (TNFR1), modulating the HMGB1/TLR4/nuclear factor-kappa B (NF-κB) and TNF-α/TNFR1/NF-κB signaling pathways and related protein expressions. Moreover, co-culture experiments showed that neuronal apoptosis induced by microglial activation was reversed by Tan IIA. In conclusion, Tan IIA provides neuroprotection by modulating signaling pathways in microglia, thus preventing neuronal apoptosis. This study offers new insights into therapeutic targets for ischemic stroke.

Gene Polymorphism Of TNF-A (Rs1799964) In Aborted Women With Respiratory Disease In Al-Diwaniyah Province

Background: TNF-α, a proinflammatory cytokine, plays a significant role in the etiology of various illnesses. The encoding gene is found on chromosome 6's short arm in the major histocompatibility complex class III region. Polymorphisms in the TNF-α gene promoter region are believed to impact illness susceptibility and severity. This review summarizes the research on the association between TNF-α gene and receptor polymorphisms and respiratory illness development. This study aim to determine of gene polymorphism of TNF-α in aborted women with respiratory diseases. Methods : The study was carried out for 100 pregnant women, including 60 aborted women with and without respiratory diseases, and 40 women as healthy control group. Genotypes in TNF-α T&gt;C SNPs were identified using self- designed nested T-ARMS PCR tests. Sequencing validated randomly chosen PCR results that represented unique genotypes in TNF-α SNPs. Results : The results of TNF-α (rs1799964) C/T SNP genotyping between aborted women with respiratory diseases and healthy control revealed that the heterozygous C/T genotype was a significant risk factor with an OR of 6.28, while the homozygous TT genotype was non-significant (OR= 2.09). Conclusion : The rs1799964 TNF-α polymorphisms are possible genetic risk factors of respiratory diseases and might be its predictive markers.

Glucoraphanin and sulforaphane mitigate TNFα-induced Caco-2 monolayers permeabilization and inflammation

Intestinal permeabilization is central to the pathophysiology of chronic gut inflammation. This study investigated the efficacy of glucoraphanin (GR), prevalent in cruciferous vegetables, particularly broccoli, and its derivative sulforaphane (SF), in inhibiting tumor necrosis factor alpha (TNFα)-induced Caco-2 cell monolayers inflammation and permeabilization through the regulation of redox-sensitive events. TNFα binding to its receptor led to a rapid increase in oxidant production and subsequent elevation in the mRNA levels of NOX1, NOX4, and Duox2. GR and SF dose-dependently mitigated both these short- and long-term alterations in redox homeostasis. Downstream, GR and SF inhibited the activation of the redox-sensitive signaling cascades NF-κB (p65 and IKK) and MAPK ERK1/2, which contribute to inflammation and barrier permeabilization. GR (1 μM) and SF (0.5–1 μM) prevented TNFα-induced monolayer permeabilization and the associated reduction in the levels of the tight junction (TJ) proteins occludin and ZO-1. Both GR and SF also mitigated TNFα-induced increased mRNA levels of the myosin light chain kinase, which promotes TJ opening. Molecular docking suggests that although GR is mostly not absorbed, it could interact with extracellular and membrane sites in NOX1. Inhibition of NOX1 activity by GR would mitigate TNFα receptor downstream signaling and associated events. These findings support the concept that not only SF, but also GR, could exert systemic health benefits by protecting the intestinal barrier against inflammation-induced permeabilization, in part by regulating redox-sensitive pathways. GR has heretofore not been viewed as a biologically active molecule, but rather, the benign precursor of highly active SF. The consumption of GR and/or SF-rich vegetables or supplements in the diet may offer a means to mitigate the detrimental consequences of intestinal permeabilization, not only in disease states but also in conditions characterized by chronic inflammation of dietary and lifestyle origin.

In-Vitro and In-Silico Studies of Brevifoliol Ester Analogues against Insulin Resistance Condition.

Brevifoliol is a diterpenoid that occurs naturally in the plants of Taxus genus and is widely used as chemotherapy agent for the management of cancer. A series of semisynthetic esters analogues of brevifoliol were prepared by Steglich esterification and attempted for their pharmacological potential against insulin resistance conditions using in-vitro and in-silico assays. The aim of this study is to understand the pharmacological potential of eighteen semisynthetic analogs through Steglich esterification of Brevifoliol against insulin resistance condition Methods: In the in-vitro study, insulin resistance condition was induced in skeletal muscle cells using TNF-α, pro-inflammatory cytokine and these cells were treated with brevifoliol analogues. The most potent analouge was further validated using in-silico docking study against the tumor necrosis factor (TNF-α) (PDB ID: 2AZ5) and Human Insulin Receptor (PDB ID: 1IR3), using the Auto dock Vina v0.8 program. Although, all the analogues of Brevifoliol significantly exhibited the pharmacological potential. Among all, analogue 17 was most potent in reversing the TNF-α induced insulin resistance condition in skeletal muscle cells and also to inhibit the production of TNF-α in LPSinduced inflammation in macrophage cells in a dose-dependent manner. Similarly, in-silico molecular docking studies revealed that analogue 17 possesses a more promising binding affinity than the selected control drug metformin toward the TNF-α and insulin receptor. These findings suggested the suitability of analogue 17 as a drug-like candidate for further investigation toward the management of insulin resistance conditions.

Protective Effects of Vitamin D on Proteoglycans of Human Articular Chondrocytes through TGF-β1 Signaling.

The extracellular matrix of cartilage primarily constitutes of collagen and aggrecan. Cartilage degradation starts with aggrecan loss in osteoarthritis (OA). Vitamin D (VD) plays an essential role in several inflammation-related diseases and can protect the collagen in cartilage during OA. The present study focused on the role of VD in aggrecan turnover of human articular chondrocytes treated with tumor necrosis factor α (TNF-α) and the possible mechanism. Treatment with different doses of VD and different periods of intervention with TNF-α and TGF-β1 receptor (TGFβR1) inhibitor SB525334 were investigated. The viability of human chondrocytes and extracellular secretion of TGF-β1 were measured. The expression of intracellular TGFβR1 and VD receptor was examined. Transcriptional and translational levels of aggrecan and the related metabolic factors were analyzed. The results showed that TNF-α markedly reduced the viability, TGFβR1 expressions and aggrecan levels of human chondrocytes, and increased disintegrin and metalloproteinase with thrombospondin motifs. The alterations were partially inhibited by VD treatment. Furthermore, the effects of VD were blocked by the TGFβR1 inhibitor SB525334 in TNF-α-treated cells. VD may prevent proteoglycan loss due to TNF-α via TGF-β1 signaling in human chondrocytes.

Interferon-gamma signaling drives epithelial TNF-alpha receptor-2 expression during colonic tissue repair.

Interferon-gamma (IFNγ) is traditionally recognized for its pro-inflammatory role during intestinal inflammation. Here, we demonstrate that IFNγ also functions as a pro-repair molecule by increasing TNFα receptor 2 (TNFR2 protein/TNFRSF1B gene) expression on intestinal epithelial cells (IEC) following injury invitro and invivo. In silico analyses identified binding sites for the IFNγ signaling transcription factor STAT1 in the promoter region of TNFRSF1B. Scratch-wounded IEC exposed to IFNγ exhibited a STAT1-dependent increase in TNFR2 expression. Insitu hybridization revealed elevated Tnfrsf1b mRNA levels in biopsy-induced colonic mucosal wounds, while intraperitoneal administration of IFNγ neutralizing antibodies following mucosal injury resulted in impaired IEC Tnfrsf1b mRNA and inhibited colonic mucosal repair. These findings challenge conventional notions that "pro-inflammatory" mediators solely exacerbate damage by highlighting latent pro-repair functions. Moreover, these results emphasize the critical importance of timing and amount in the synthesis and release of IFNγ and TNFα during the inflammatory process, as they are pivotal in restoring tissue homeostasis.

Mesalamine may be a Plausible Therapeutic Agent for the Management of Diabetic Wounds: A Computational Approach

Aim: Validation of mesalamine (MS) as a potential therapeutic agent in treating diabetic wound (DW) healing using in silico approach. Background: Diabetic wound (DW) is a serious consequence of diabetes that frequently results in the amputation of the affected organ. Maggot therapy, pressure off-loading, surgical intervention, glucose control, hyperbaric oxygen therapy, wound debridement, and other treatments are currently available for DW. However, the majority of people do not meet all DW requirements due to significant pathology and the high expense of the solutions. Objective: To address the issues with current conventional therapy, we reasoned that repurposing existing medication (MS) to a target receptor that plays a significant role in the progression of DW might be advantageous. Mesalamine (MS), also known as Mesalazine or 5- Aminosalicylic acid, is an aminosalicylate anti-inflammatory used to treat inflammatory bowel disease (IBD), ulcerative colitis (UC), inflamed anus or rectum. The complicated pathophysiology of DW, which includes prolonged inflammation, increased infection, decreased cell proliferation, and migration, is a serious issue. As a result, we chose the MMP-9, TNF-α, MurC, ParE, and GSK-3β receptors as a universal target for treating the complex pathogenesis of DW. The use of MS as a therapeutic modulator on MMP-9, TNF-α, MurC, ParE, and GSK-3β receptors was studied in the current hypothetical investigation. Methods: Computational studies such as molecular docking and MMGBSA were performed by using the Schrödinger suite. Results: Computational investigations, such as molecular docking and MMGBSA were used to test our theory. It is clear from the in silico methods that MS has a higher binding affinity for the designated receptors. Hence, it is predicted that MS may be a good therapeutic agent to use in the treatment of DW. Conclusion: As a result of our findings, MS appears to be a unique therapeutic drug for the treatment of DW. However, further studies are highly required to take MS into clinical use.

Biologics in Focus: A Comprehensive Review of Current Biological and Small Molecules Therapies for Crohn’s Disease in the United Arab Emirates (UAE)

Introduction: The management of Crohn’s disease (CD) in the Middle East, like in other parts of the world, is rapidly evolving with the introduction of novel advanced medical and biological therapies. In the United Arab Emirates (UAE), several biological therapies are used to achieve remission in severe and resistant cases of CD. We carried out a literature search to analyze the effectiveness and safety of biologic treatments currently licensed in the UAE. Methods: We searched the PubMed, Embase and Cochrane library databases from inception to January 2020 to identify relevant studies. Search terms were generated using established treatment guidelines for CD. We also manually searched the bibliographies of relevant literature to obtain additional papers. Results: Biologic and small molecule agents for CD include four core drug classes: anti-tumor necrosis factor-α agents (TNF-α), integrin receptor antagonists, Janus kinase (JAK) inhibitors and IL-12/IL-23 antagonists. All drug classes showed good efficacy and safety in managing patients with CD. Some drug classes had distinguishable side effect profiles. This included an increased lymphoma and tuberculous risk for TNF-α and integrin receptor antagonists. Many trials supported the effectiveness of these licensed drugs. Biologic agent intolerance was common; one-third of patients receiving TNF-α treatment will develop intolerance to that specific drug. Conclusions: Advanced medical therapies licensed in the UAE have proven to be safe and efficacious. Additional research is required to evaluate the safety and efficacy of newer biologics and biosimilars.

Relationship between plasma TNF-α levels and agitation symptoms in first episode patients with schizophrenia

BackgroundIncreasing evidence suggested that immune abnormalities involved in the pathophysiology of schizophrenia. However, the relationship between immunity and clinical features has not been clarified. The aim of this study was to measure the plasma levels of tumor necrosis factor alpha (TNF-α) and soluble TNF-α receptor 1 (sTNF-α R1) and to investigate their association with agitation in first episode patients with schizophrenia (FEPS).MethodsThe plasma TNF-α and sTNF-α R1 levels were measured using sandwich enzyme-linked immunosorbent assay (ELISA) in the FEPS with (n = 36) and without agitation (n = 49) symptoms, and healthy controls (HCs, n = 54). The psychopathology was assessed by the Positive and Negative Syndrome Scale (PANSS), and the agitation symptoms were evaluated by the PANSS excitatory component (PANSS-EC).ResultsThe plasma TNF-α levels in patients with and without agitation symptoms were significantly higher than those in HCs. The patients with agitation had significantly higher plasma TNF-α levels compared to the patients without agitation. There were no significant differences in the sTNF-α R1 levels among the three groups. Furthermore, the plasma TNF-α levels were positively correlated with the PANSS total score, Positive and General psychopathological subscores, and PANSS-EC score in the FEPS, but the relationships were not found for the plasma sTNF-α R1 levels.ConclusionsThese results suggested that TNF-α might play an important role in the onset and development of agitation symptoms of schizophrenia.

Augmentation of Nitric Oxide Deficient Hypertension by High Salt Diet Is Associated With Reduced TNF-α Receptor Type 1 Expression in the Kidneys.

High salt (HS) intake induces an augmented hypertensive response to nitric oxide (NO) inhibition, though it causes minimal changes in blood pressure (BP) in NO intact condition. The cause of such augmentation is not known. HS induces tumor necrosis factor-alpha (TNFα) production that causes natriuresis via activation of its receptor type 1 (TNFR1). We hypothesized that NO deficiency reduces renal TNFR1 activity, leading to enhanced sodium retention and hypertension. We examined the changes in renal TNFR1 protein expression (Immunohistochemistry analyses) after HS (4% NaCl) intake in wild-type mice (WT, C57BL6) treated with a NO synthase (NOS) inhibitor, nitro-l-arginine methyl ester (L-NAME; 0.05 mg/min/g; osmotic mini-pump), as well as in endothelial NOS knockout mice (eNOSKO) and compared the responses in WT mice with normal salt (NS; 0.3% NaCl) intake. BP was measured with tail-cuff plethysmography and 24-hour urine collections were made using metabolic cages. HS alone did not alter mean BP in untreated mice (76 ± 3 to 77 ± 1 mm Hg) but induced an augmented response in L-NAME treated (106 ± 1 vs. 97 ± 2 mm Hg) and in eNOSKO (107 ± 2 vs. 89 ± 3 mm Hg) mice. The percentage area of TNFR1 expression in renal tissue was higher in WT + HS (4.1 + 0.5%) than in WT + NS mice (2.7 ± 0.6%). However, TNFR1 expression was significantly lower in L-NAME treated WT + NS (0.9 ± 0.1%) and in eNOSKO + NS (1.4 ± 0.2%) than in both WT + NS and WT + HS mice. These data indicate that TNFR1 activity is downregulated in NO deficient conditions, which facilitates salt retention leading to augmented hypertension during HS intake.

Quality of life and strength, but not cytokines, are associated with DAS-28 in active and inactive rheumatoid arthritis

Objective: Evaluate and correlate data between relevant cytokines, disease progression, and handgrip and quality of life among RA patients at different stages of disease progression. Method: Thirty-three RA patients were recruited for analysis, using comparisons and correlations, between levels of circulating cytokines (IFN-γ, TNF-α, IL-4, IL-6, IL-10, IL-17, IL-1β, and TNF receptors I and II), activity of the disease (evaluated using the DAS-28), handgrip (Hydraulic dynamometer), and quality of life (SF-36). Result: RA patients in different disease stages showed increases of IL-6 and IL-10 compared control group. Positive correlation between IL-6 with TNF-α, and IL-4 with IL-10 was found. Handgrip strength and quality of life were not related to cytokine levels. However, remission patients had better strength and quality of life indices compared to the active patients. In addition, handgrip of the non-dominant side, physical functions, role limitations physical health, pain, energy/fatigue and social functions have a negative correlation with the DAS28-PCR. Conclusion: High levels of IL-6 and IL-10 were observed in the chronic RA patients, but the values did not show correlation with disease activity, handgrip strength and quality of life. Disease activity show correlation with handgrip strength and quality of life. Furthermore, remission patients had better strength and quality of life indices compared to the active patients.

Protective role of RIPK1 scaffolding against HDV-induced hepatocyte cell death and the significance of cytokines in mice.

Hepatitis delta virus (HDV) infection represents the most severe form of human viral hepatitis; however, the mechanisms underlying its pathology remain incompletely understood. We recently developed an HDV mouse model by injecting adeno-associated viral vectors (AAV) containing replication-competent HBV and HDV genomes. This model replicates many features of human infection, including liver injury. Notably, the extent of liver damage can be diminished with anti-TNF-α treatment. Here, we found that TNF-α is mainly produced by macrophages. Downstream of the TNF-α receptor (TNFR), the receptor-interacting serine/threonine-protein kinase 1 (RIPK1) serves as a cell fate regulator, playing roles in both cell survival and death pathways. In this study, we explored the function of RIPK1 and other host factors in HDV-induced cell death. We determined that the scaffolding function of RIPK1, and not its kinase activity, offers partial protection against HDV-induced apoptosis. A reduction in RIPK1 expression in hepatocytes through CRISPR-Cas9-mediated gene editing significantly intensifies HDV-induced damage. Contrary to our expectations, the protective effect of RIPK1 was not linked to TNF-α or macrophage activation, as their absence did not alter the extent of damage. Intriguingly, in the absence of RIPK1, macrophages confer a protective role. However, in animals unresponsive to type-I IFNs, RIPK1 downregulation did not exacerbate the damage, suggesting RIPK1's role in shielding hepatocytes from type-I IFN-induced cell death. Interestingly, while the damage extent is similar between IFNα/βR KO and wild type mice in terms of transaminase elevation, their cell death mechanisms differ. In conclusion, our findings reveal that HDV-induced type-I IFN production is central to inducing hepatocyte death, and RIPK1's scaffolding function offers protective benefits. Thus, type-I IFN together with TNF-α, contribute to HDV-induced liver damage. These insights may guide the development of novel therapeutic strategies to mitigate HDV-induced liver damage and halt disease progression.

TNF-a Receptor 1 Activity Is Differentially Required for Phrenic Long-term Facilitation (pLTF) Over the Course of Motor Neuron Death in Adult Rats

Intrapleural injection of cholera toxin B fragment conjugated to saporin (CTB-SAP) selectively kills respiratory motor neurons, and mimics aspects of neuromuscular disorders and neurodegenerative diseases including phrenic motor neuron death, decreased phrenic motor output, and increased microglial cell number. Over the course of motor neuron loss, enhanced A2A receptor-dependent phrenic plasticity is observed early (7d), and then constrained 5-HT receptor-dependent phrenic plasticity is observed later (28d). In addition, COX-1/2-induced inflammation differentially impacts breathing and phrenic plasticity in CTB-SAP rats, but the underlying mechanism by which COX-1/2-induced inflammation impacts breathing and plasticity over the course of motor neuron death has not been studied. We observe that increased cervical neuroinflammatory gene expression ( e.g., tumor necrosis factor-a; TNF-a) is reduced back to control levels in the presence of ketoprofen in CTB-SAP rats, and it is known that TNF-a is involved in phrenic plasticity in naïve rats. Thus, we hypothesized that acute TNF-a receptor inhibition attenuates phrenic plasticity at 7d and enhances it at 28d TNF-a following CTB-SAP-induced neuropathology. Using anesthetized, paralyzed and ventilated CTB-SAP-treated adult Sprague Dawley rats, we studied acute intermittent hypoxia (AIH; 3, 5 min bouts of 10.5% O2) induced pLTF following acute intrathecal C4 delivery of a TNF-a receptor 1 inhibitor (soluble TNFR1; sTNFR1; 0.13 ug/ul) or vehicle (aCSF) to rats that received bilateral, intrapleural injections of: 1) CTB-SAP (25ug), or 2) un-conjugated CTB and SAP (control) in rats treated 7d or 28d prior. Surprisingly, preliminary results indicate that acute sTNFR1 delivery does not affect pLTF in 7d CTB-SAP-treated rats (n=5; i.e., pLTF still enhanced) but it enhanced pLTF in 28d CTB-SAP-treated rats (n=6; p&lt;0.05) vs. controls (n=6 at 7d; n=7 at 28d) and vs. vehicle treated rats (controls n=6 for 7d and n=9 for 28d; CTB-SAP, n=4 for 7d and 28d each). These preliminary observations suggest that TNF-a does not contribute to pLTF in 7d CTB-SAP-treated rats, whereas it may undermine pLTF in 28d CTB-SAP-treated rats. Studies are underway to assess the cellular source of TNF-a and the impact of chronic sTNFR1 delivery on pLTF, diaphragm activity, and breathing. Since most patients with neuromuscular disorders or neurodegenerative disease develop respiratory insuffciency and ultimately become ventilator dependent, our long-range goal is to develop new strategies to enhance the functional capacity of spared motor neurons and reduce ventilatory compromise in motor neuron loss pathology. These novel strategies, if successful, will identify new therapeutic targets for future, translational studies to enhance breathing in patients with neuromuscular disorders. Supported by a Spinal Cord Injury and Disease Research grant. This is the full abstract presented at the American Physiology Summit 2024 meeting and is only available in HTML format. There are no additional versions or additional content available for this abstract. Physiology was not involved in the peer review process.

The involvement of RIPK4 in TNF-α-stimulated IL-6 and IL-8 production by melanoma cells

PurposeThe receptor-interacting protein kinase (RIPK4) has an oncogenic function in melanoma, regulates NF-κB and Wnt/β-catenin pathways, and is sensitive to the BRAF inhibitors: vemurafenib and dabrafenib which lead to its decreased level. As its role in melanoma remains not fully understood, we examined the effects of its downregulation on the transcriptomic profile of melanoma.MethodsApplying RNA-seq, we revealed global alterations in the transcriptome of WM266.4 cells with RIPK4 silencing. Functional partners of RIPK4 were evaluated using STRING and GeneMANIA databases. Cells with transient knockdown (via siRNA) and stable knockout (via CRISPR/Cas9) of RIPK4 were stimulated with TNF-α. The expression levels of selected proteins were assessed using Western blot, ELISA, and qPCR.ResultsGlobal analysis of gene expression changes indicates a complex role for RIPK4 in regulating adhesion, migration, proliferation, and inflammatory processes in melanoma cells. Our study highlights potential functional partners of RIPK4 such as BIRC3, TNF-α receptors, and MAP2K6. Data from RIPK4 knockout cells suggest a putative role for RIPK4 in modulating TNF-α-induced production of IL-8 and IL-6 through two distinct signaling pathways—BIRC3/NF-κB and p38/MAPK. Furthermore, increased serum TNF-α levels and the correlation of RIPK4 with NF-κB were revealed in melanoma patients.ConclusionThese data reveal a complex role for RIPK4 in regulating the immune signaling network in melanoma cells and suggest that this kinase may represent an alternative target for melanoma-targeted adjuvant therapy.