The crosstalk between macrophages and cancer cells potentiates pancreatic cancer cachexia.

With limited treatment options, cachexia remains a major challenge for patients with cancer. Characterizing the interplay between tumor cells and the immune microenvironment may help identify potential therapeutic targets for cancer cachexia. Herein, we investigate the critical role of macrophages in potentiating pancreatic cancer induced muscle wasting via promoting TWEAK (TNF-like weak inducer of apoptosis) secretion from the tumor. Specifically, depletion of macrophages reverses muscle degradation induced by tumor cells. Macrophages induce non-autonomous secretion of TWEAK through CCL5/TRAF6/NF-κB pathway. TWEAK promotes muscle atrophy by activating MuRF1 initiated muscle remodeling. Notably, tumor cells recruit and reprogram macrophages via the CCL2/CCR2 axis and disrupting the interplay between macrophages and tumor cells attenuates muscle wasting. Collectively, this study identifies a feedforward loop between pancreatic cancer cells and macrophages, underlying the non-autonomous activation of TWEAK secretion from tumor cells thereby providing promising therapeutic targets for pancreatic cancer cachexia.

Sarcopenia is associated with hypomethylation of TWEAK and increased plasma levels of TWEAK and its downstream inflammatory factor TNF-α in older adults: A case-control study.

BACKGROUND: Sarcopenia is a harmful condition common among older adults for which no treatment is available. Tumor necrosis factor (TNF)-like weak inducer of apoptosis (TWEAK) and its receptor fibroblast growth factor inducible 14 (FN14) are known to play important roles in the pathogenesis of sarcopenia. This study investigated alterations in methylation in TWEAK and Fn14 to identify potential targets for the managing sarcopenia. MATERIALS AND METHODS: Through an epidemiological investigation, we detected methylation of CpG islands (CpGs) in TWEAK and Fn14 in community-dwelling older adult of Xinjiang by bisulfite sequencing. Significant CpGs associated with sarcopenia were selected for detection in 152 older individuals by pyrosequencing. Associations between CpG methylation, plasma inflammatory marker levels, and sarcopenia were analyzed. RESULTS: Of 38 CpGs in TWEAK and 30 CpGs in Fn14 detected in 60 individuals, 6 CpGs showed lower methylation in sarcopenia patients compared with control individuals. In 152 older adults, covariance analysis with adjustment for age, gender, triglyceride level, obesity, diabetes, and hypertension showed that the methylation levels of 6 CpGs (CpG8, CpG12, CpG13, CpG20 and CpG21of TWEAK, and CpG24 of Fn14) were significantly lower in sarcopenia patients than in control individuals. With adjustment for additional confounding factors, covariate variance analysis showed that plasma TWEAK, TNF-α and IL-10 levels in the sarcopenia group were significant higher than those in the control group (P = 0.007, P < 0.001, P = 0.003). Multivariate logistic regression analysis showed that CpG8, CpG13, CpG21, and total methylation of TWEAK (OR = 0.767, 95 % CI = 0.622-0.947; OR = 0.740, 95 % CI = 0.583-0.941; OR = 0.734, 95 % CI = 0.561-0.958; OR = 0.883, 95 % CI = 0.795-0.980) as well as CpG22 and total methylation of Fn14 were significantly associated with sarcopenia (OR = 826, 95 % CI = 0.704-0.968; OR = 0.918, 95 % CI = 0.852-0.989). From partial correlation analysis, plasma TWEAK was correlated with plasma TNF-α (r = 0.172, P = 0.042). CONCLUSION: Sarcopenia is associated with hypomethylation of TWEAK and increased plasma levels of TWEAK and its downstream inflammatory factor TNF-α in a community-dwelling population of older adults in Xinjiang.

TWEAK levels in psoriatic patients treated with narrowband ultraviolet B and methotrexate.

BACKGROUND: Psoriasis is an autoimmune disease which has an effect on the joints and skin. Tumor Necrosis Factor-Like Weak Inducer of Apoptosis (TWEAK) is a multi-functional cytokine which regulates the cellular processes and has been related to a variation of conditions. OBJECTIVES: To measure the level of serum TWEAK in psoriatic diseased persons and its relationship to the PASI score pre- and post-therapy with narrowband ultraviolet B phototherapy (NB-UVB) and methotrexate (MTX). METHODS: This randomized controlled trial was conducted on 40 patients and 20 healthy persons as controls. Patient Group was randomly subdivided to two groups. The 1st group consisted of 20 patients who received NB-UVB treatment. The 2nd group included 20 MTX-treated candidates. Blood samples were drawn from patients in order to detect serum TWEAK levels using ELISA. The research was registered on Clinical Trials Registration: RCT approval numbers: NCT0481191. RESULTS: The mean PASI score percent improvement after 12 weeks of treatment was higher in the MTX group (90%) than NB-UVB group (60%). The serum TWEAK level at baseline was 60.47 ± 12.6 pg/mL in NB-UVB group and 54.69 ± 21.7 pg/mL in MTX group which reduced to 24.93 ± 17.6 pg/mL and 32.13 ± 23.6 pg/mL, respectively (p < 0.001), after 12 weeks of treatment. There was a positive correlation between the serum levels of TWEAK and severity of PASI score (r = 0.399, p = 0.014). CONCLUSION: TWEAK grades in psoriasis are substantially higher than in controls. TWEAK levels were dramatically reduced during NB-UVB and MTX treatment. TWEAK may have a potential sign for psoriasis diagnosis and prognosis.

Th17 Cells Secrete TWEAK to Trigger Epithelial-Mesenchymal Transition and Promote Colorectal Cancer Liver Metastasis.

Liver metastasis is the leading cause of mortality in patients with colorectal cancer. Given the significance of both epithelial-mesenchymal transition (EMT) of tumor cells and the immune microenvironment in colorectal cancer liver metastasis (CRLM), the interplay between them could hold the key for developing improved treatment options. We employed multiomics analysis of 130 samples from 18 patients with synchronous CRLM integrated with external datasets to comprehensively evaluate the interaction between immune cells and EMT of tumor cells in liver metastasis. Single-cell RNA sequencing analysis revealed distinct distributions of nonmalignant cells between primary tumors from patients with metastatic colorectal cancer (mCRC) and non-metastatic colorectal cancer, showing that Th17 cells were predominantly enriched in the primary lesion of mCRC. TWEAK, a cytokine secreted by Th17 cells, promoted EMT by binding to receptor Fn14 on tumor cells, and the TWEAK-Fn14 interaction enhanced tumor migration and invasion. In mouse models, targeting Fn14 using CRISPR-induced knockout or lipid nanoparticle-encapsulated siRNA alleviated metastasis and prolonged survival. Mice lacking Il17a or Tnfsf12 (encoding TWEAK) exhibited fewer metastases compared with wild-type mice, while cotransfer of Th17 with tumor cells promoted liver metastasis. Higher TWEAK expression was associated with a worse prognosis in patients with colorectal cancer. In addition, CD163L1+ macrophages interacted with Th17 cells, recruiting Th17 via the CCL4-CCR5 axis. Collectively, this study unveils the role of immune cells in the EMT process and identifies TWEAK secreted by Th17 as a driver of CRLM. SIGNIFICANCE: TWEAK secreted by Th17 cells promotes EMT by binding to Fn14 on colorectal cancer cells, suggesting that blocking the TWEAK-Fn14 interaction may be a promising therapeutic approach to inhibit liver metastasis.

Systemic biomarker associated with poor outcome after futile reperfusion.

BACKGROUND: Successful recanalization does not lead to complete tissue reperfusion in a considerable percentage of ischemic stroke patients. This study aimed to identify biomarkers associated with futile recanalization. Leukoaraiosis predicts poor outcomes of this phenomenon. Soluble tumour necrosis factor-like weak inducer of apoptosis (sTWEAK), which is associated with leukoaraiosis degrees, could be a potential biomarker. METHODS: This study includes two cohorts of ischemic stroke patients in a multicentre retrospective observational study. Effective reperfusion, defined as a reduction of ≥8 points in the National Institutes of Health Stroke Scale (NIHSS) within the first 24 h, was used as a clinical marker of effective reperfusion. RESULTS: In the first cohort study, female sex, age, and high NIHSS at admission (44.7% vs. 81.1%, 71.3 ± 13.7 vs. 81.1 ± 6.7; 16 [13, 21] vs. 23 [17, 28] respectively; p < .0001) were confirmed as predictors of futile recanalization. ROC curve analysis showed that leukocyte levels (sensitivity of 99%, specificity of 55%) and sTWEAK level (sensitivity of 92%, specificity of 88%) can discriminate between poor and good outcomes. Both biomarkers simultaneously are higher associated with outcome after effective reperfusion (OR: 2.17; CI 95% 1.63-4.19; p < .0001) than individually (leukocytes OR: 1.38; CI 95% 1.00-1.64, p = .042; sTWEAK OR: 1.00; C I95% 1.00-1.01, p = .019). These results were validated using a second cohort, where leukocytes and sTWEAK showed a sensitivity of 100% and specificity of 66.7% and 75% respectively. CONCLUSIONS: Leukocyte and sTWEAK could be biomarkers of reperfusion failure and subsequent poor outcomes. Further studies will be necessary to explore its role in reperfusion processes.

Clinical utility of circulating TWEAK and CD163 as biomarkers of iron-induced cardiac decompensation in transfusion dependent thalassemia major.

BACKGROUND AND AIM: Tumor necrosis factor-like weak inducer of apoptosis (TWEAK) affects most of the cells involved in cardiac fibrosis like inflammatory cells, cardiomyocytes and fibroblasts. CD163, the receptor of TWEAK on the surface of type 2 macrophages, is shed into plasma upon macrophages activation. This work aimed to evaluate serum TWEAK and its decoy receptor CD163 as probable biomarkers to monitor myocardial iron overload (MIO) in transfusion dependent thalassemia major (TDTM) patients and to predict iron-induced cardiac decompensation (IICD). METHODS: A total of 140 TDTM patients were enrolled. Patients were categorized into two groups; group I (n = 70) diagnosed with IICD while group II (n = 70) had no evidence of IICD. sTWEAK and sCD163 were quantitated utilizing Enzyme-linked-immunosorbent- assay. RESULTS: sTWEAK was evidently lower in group I than group II (medians, 412 and 1052 pg/mL respectively). sCD163 was higher in group I than group II (medians, 615.5 and 323.5 ng/mL respectively). sTWEAK positively correlated with cardiac MRI-T2 mapping and ventricular ejection fractions and negatively correlated with B-Natriuretic peptide and cardiac troponin. An inverse relationship between TWEAK and CD163 was documented throughout the study. sTWEAK, sCD163 and TWEAK/CD163 ratio proved to be significant predictors of IICD in TDTM patients. TWEAK/CD163 ratio < 1.04 discriminated IICD in TDTM patients with 100 % clinical sensitivity and specificity. CONCLUSION: Circulating TWEAK and CD163 appears to be promising biomarkers for monitoring MIO and predicting IICD in TDTM patients.

[Correlation of expression of silencing information regulator 2 related enzyme 1 and tumor necrosis factor-like weak inducer of apoptosis in articular effusion and knee osteoarthritis].

OBJECTIVE: To analyze the correlation between the expression of silencing information regulator 2 related enzyme 1 (SIRT1), tumor necrosis factor like weak inducer of apoptosis (TWEAK) and knee osteoarthritis. METHODS: Total of 103 patients with knee joint (knee osteoarthritis group) from February 2019 to August 2021 were selected including 40 males and 63 females with an average age of (62.02±6.09) years;according to the modified Mankin score, 103 patients were divided into mild group (Mankin score 1-4 points, 31 cases) and moderate group (Mankin score 5-8 points, 40 cases) and severe group (Mankin score ≥9, 32 cases). Another 105 physical examination volunteers were selected as the control group including 46 males and 59 females with an average age of (62.11±6.34) years old. The levels of SIRT1 and TWEAK in articular effusion and serum were detected in the knee osteoarthritis group, while serum SIRT1 and TWEAK were detected in the control group only. The relationship between SIRT1, TWEAK and the occurrence and disease of knee osteoarthritis were analyzed. RESULTS: Articular cavity fluid TWEAK, serum TWEAK, CRP, IL-6, IL-1ß, white blood cell count and ESR were higher than those in the control group(P<0.05), articular cavity fluid SIRT1 and serum SIRT1 were lower than those in the control group(P<0.05). TWEAK level in the severe group was higher than that in the moderate and mild groups(P<0.05), SIRT1 was lower than that in the moderate and mild groups (P<0.05). The level of SIRT1 in articular cavity effusion was positively correlated with the serum level of SIRT1 (P<0.05), and negatively correlated with CRP, IL-6, IL-1ß, white blood cell count, modified Mankin score and ESR (P<0.05). TWEAK level in articular cavity fluid was positively correlated with serum TWEAK level (P<0.05), C-reactive protein(CRP), interleukin(IL)-6, IL-1ß, white blood cell count, modified Mankin score and erythrocyte sedimentation rate(ESR) (P<0.05). Body mass index, undertaking heavy physical work, and articular cavity fluid TWEAK were risk factors for the occurrence of knee osteoarthritis(P<0.05), and articular cavity fluid SIRT1 was a protective factor for the occurrence of knee arthritis (P<0.05). The area under curve(AUC) of SIRT1 and TWEAK for knee osteoarthritis was 0.641 and 0.653, and the AUC of SIRT1 and TWEAK for knee osteoarthritis was 0.879, which was higher than SIRT1 and TWEAK alone (z=6.105 and 6.225, P<0.05). CONCLUSION: The level of SIRT1 in articular fluid in patients with knee arthritis is decreased and the level of TWEAK is increased. Low SIRT1 and high TWEAK are associated with the onset and exacerbation of knee osteoarthritis.

Tweak/Fn14 system is involved in rhabdomyolysis-induced acute kidney injury.

BACKGROUND: Rhabdomyolysis is a severe clinical syndrome associated to acute kidney injury (AKI) and chronic kidney disease (CKD). TWEAK/Fn14 signaling axis regulates renal inflammation and tubular cell death. However, the functional role of TWEAK/Fn14 in rhabdomyolysis remains unknown. METHODS: Rhabdomyolysis was induced in wild-type, TWEAK- and Fn14-deficient mice or mice treated with TWEAK blocking antibody. Renal injury, inflammation, fibrosis and cell death were assessed. Additionally, we performed in vivo and in vitro studies to explore the possible signalling pathways involved in Fn14 regulation. FINDINGS: Fn14 renal expression was increased in mice with rhabdomyolysis, correlating with decline of renal function. Mechanistically, myoglobin (Mb) induced Fn14 expression via ERK and p38 pathway, whereas Nrf2 activation diminished Mb-mediated Fn14 upregulation in cultured renal cells. TWEAK or Fn14 genetic depletion ameliorated rhabdomyolysis-associated loss of renal function, histological damage, tubular cell death, inflammation, and expression of both tubular and endothelial injury markers. Deficiency of TWEAK or Fn14 also decreased long-term renal inflammation and fibrosis in mice with rhabdomyolysis. Finally, pharmacological treatment with a blocking TWEAK antibody diminished the expression of acute renal injury markers and cell death and lessened residual kidney fibrosis and chronic inflammation in rhabdomyolysis. INTERPRETATION: TWEAK/Fn14 axis participates in the pathogenesis of rhabdomyolysis-AKI and subsequent AKI-CKD transition. Blockade of this signaling pathway may represent a promising therapeutic strategy for reducing rhabdomyolysis-mediated renal injury. FUNDING: Spanish Ministry of Science and Innovation, ISCIII and Junta de Andalucía.

Targeting the TWEAK-Fn14 pathway prevents dysfunction in cardiac calcium handling after acute kidney injury.

Heart and kidney have a closely interrelated pathophysiology. Acute kidney injury (AKI) is associated with significantly increased rates of cardiovascular events, a relationship defined as cardiorenal syndrome type 3 (CRS3). The underlying mechanisms that trigger heart disease remain, however, unknown, particularly concerning the clinical impact of AKI on cardiac outcomes and overall mortality. Tumour necrosis factor-like weak inducer of apoptosis (TWEAK) and its receptor fibroblast growth factor-inducible 14 (Fn14) are independently involved in the pathogenesis of both heart and kidney failure, and recent studies have proposed TWEAK as a possible therapeutic target; however, its specific role in cardiac damage associated with CRS3 remains to be clarified. Firstly, we demonstrated in a retrospective longitudinal clinical study that soluble TWEAK plasma levels were a predictive biomarker of mortality in patients with AKI. Furthermore, the exogenous application of TWEAK to native ventricular cardiomyocytes induced relevant calcium (Ca2+ ) handling alterations. Next, we investigated the role of the TWEAK-Fn14 axis in cardiomyocyte function following renal ischaemia-reperfusion (I/R) injury in mice. We observed that TWEAK-Fn14 signalling was activated in the hearts of AKI mice. Mice also showed significantly altered intra-cardiomyocyte Ca2+ handling and arrhythmogenic Ca2+ events through an impairment in sarcoplasmic reticulum Ca2+ -adenosine triphosphatase 2a pump (SERCA2a ) and ryanodine receptor (RyR2 ) function. Administration of anti-TWEAK antibody after reperfusion significantly improved alterations in Ca2+ cycling and arrhythmogenic events and prevented SERCA2a and RyR2 modifications. In conclusion, this study establishes the relevance of the TWEAK-Fn14 pathway in cardiac dysfunction linked to CRS3, both as a predictor of mortality in patients with AKI and as a Ca2+ mishandling inducer in cardiomyocytes, and highlights the cardioprotective benefits of TWEAK targeting in CRS3. © 2023 The Authors. The Journal of Pathology published by John Wiley & Sons Ltd on behalf of The Pathological Society of Great Britain and Ireland.

Proteome-Wide Mendelian Randomization Analysis Identified Potential Drug Targets for Atrial Fibrillation.

Background Finding effective and safe therapeutic drugs for atrial fibrillation (AF) is an important concern for clinicians. Proteome-wide Mendelian randomization analysis provides new ideas for finding potential drug targets. Methods and Results Using a proteome-wide Mendelian randomization approach, we assessed the genetic predictive causality between thousands of proteins and AF risk and found that genetically predicted plasma levels of phosphomevalonate kinase, tumor necrosis factor ligand superfamily member 12, sulfhydryl oxidase 2, interleukin-6 receptor subunit alpha, and low-affinity immunoglobulin gamma Fc region receptor II-b might decrease AF risk, while genetically predicted plasma levels of beta-mannosidase, collagen alpha-1(XV) chain, ANXA4 (annexin A4), COF2 (cofilin-2), and RAB1A (Ras-related protein Rab-1A) might increase AF risk (P<3.4×10-5). By using different Mendelian randomization methods and instrumental variable selection thresholds, we performed sensitivity analyses in 30 scenarios to test the robustness of positive findings. Replication analyses were also performed in independent samples to further avoid false-positive findings. Drugs targeting tumor necrosis factor ligand superfamily member 12, interleukin-6 receptor subunit alpha, low-affinity immunoglobulin gamma Fc region receptor II-b, and annexin A4 are approved or in development. The results of the phenome-wide Mendelian randomization analysis showed that changing the plasma levels of phosphomevalonate kinase, cofilin-2, annexin A4, Ras-related protein Rab-1A, sulfhydryl oxidase 2, and collagen alpha-1(XV) chain did not increase the risk of other diseases while decreasing the risk of AF. Conclusions We found a significant causal association between genetically predicted levels of 10 plasma proteins and AF risk. Four of these proteins have drugs targeting them that are approved or in development, and our results suggest the potential for these drugs to treat AF or cause AF. Sulfhydryl oxidase 2, low-affinity immunoglobulin gamma Fc region receptor II-b, and beta-mannosidase have not been suggested by previous laboratory or epidemiological studies to be associated with AF and may reveal new pathophysiological pathways as well as therapeutic targets for AF.

Sclerostin and TNF-related weak inducer of apoptosis: can they be important in the patients with glomerulonephritis?

OBJECTIVE: Sclerostin is a protein produced by osteocytes, kidneys, and vascular cells and has many effects on kidney and vascular structures. Soluble TNF-related weak inducer of apoptosis is a proinflammatory cytokine that may cause glomerular and tubular injury and increase sclerostin expression. This study aimed to investigate serum sclerostin and soluble TNF-related weak inducer of apoptosis levels in patients with glomerulonephritis and the effects they may be associated with. METHODS: This cross-sectional study included 93 patients, 63 of whom were glomerulonephritis and 30 were healthy controls. Serum sclerostin, soluble TNF-related weak inducer of apoptosis, and 24-h urinary protein excretion were measured, and pulse wave velocity was calculated for arterial stiffness. RESULTS: Serum sclerostin and soluble TNF-related weak inducer of apoptosis were higher in glomerulonephritis patients than in the control group, and serum sclerostin and soluble TNF-related weak inducer of apoptosis levels were correlated with both proteinuria and pulse wave velocity. In addition, in the regression analysis, serum sclerostin and soluble TNF-related weak inducer of apoptosis levels were found to be independent predictors of proteinuria in patients with glomerulonephritis. CONCLUSION: This is the first study to show that serum sclerostin and soluble TNF-related weak inducer of apoptosis are elevated in glomerulonephritis patients, and these two markers correlate with arterial stiffness and proteinuria in these patients. Considering the effects of sclerostin and soluble TNF-related weak inducer of apoptosis in patients with glomerulonephritis, we think these mechanisms will be the target of both diagnosis and new therapies.

A2OURSR: Adaptive adjustment based real MRI super-resolution via opinion-unaware measurements.

High-quality and high-resolution magnetic resonance (MR) images can provide more details for diagnosis and analyses. Recently, MR images guided neurosurgery has become an emerging technique in clinics. Unlike other medical imaging techniques, it is impossible to achieve both real-time imaging and high image quality in MR imaging. The real-time performance is closely related to the nuclear magnetic equipment itself as well as the collection strategy of the k space data. Optimizing the imaging time cost via the corresponding algorithm is harder than enhancing image quality. Further, in reconstructing low-resolution and noise-rich MR images, getting relatively high-definition and resolution MR images as references are difficult or impossible. In addition, the existing methods are restricted in learning the controllable functions under the supervision of known degradation types and levels. As a result, severely bad results are inevitable when the modeling assumptions are far apart from the actual situation. To address these problems, we propose a novel adaptive adjustment method based on real MR images via opinion-unaware measurements for real super-resolution (A2OURSR). It can estimate the degree of blur and noise from the test image itself using two scores. These two scores can be considered pseudo labels to train the adaptive adjustable degradation estimation module. Then, the outputs of the above model are used as the inputs of the conditional network to tweak the generated results. Thus, the results can be automatically adjusted via the whole dynamic model. Extensive experimental results show that the proposed A2OURSR is superior to state-of-the-art methods on benchmarks quantitatively and visually.

TWEAK and Fn14 are overexpressed in immune-mediated necrotizing myopathy: implications for muscle damage and repair.

OBJECTIVES: TNF-like weak inducer of apoptosis (TWEAK) and its sole receptor fibroblast growth factor-inducible 14 (Fn14) are involved in various inflammatory conditions. This study was performed to investigate the potential role of TWEAK/Fn14 in immune-mediated necrotizing myopathy (IMNM). METHODS: Muscle biopsies from patients with IMNM (n = 37) and controls (n = 11) were collected. Human muscle cells were treated with TWEAK in vitro. Muscle biopsies and cultured muscle cells were analysed by immunostaining and quantitative PCR. Serum levels of TWEAK and Fn14 were detected by ELISA. RESULTS: TWEAK and Fn14 were overexpressed in IMNM muscle biopsies. The percentage of Fn14-positive myofibers correlated with disease severity, myonecrosis, regeneration and inflammation infiltrates. Fn14-positive myofibers tended to be surrounded or invaded by CD68+ macrophages. TWEAK treatment had a harmful effect on cultured muscle cells by inducing the production of multiple chemokines and pro-inflammatory cytokines. Serum Fn14 levels were increased in patients with IMNM and correlated with muscle weakness. CONCLUSIONS: TWEAK/Fn14 signalling was activated in IMNM, most likely aggravating muscle damage via amplifying inflammatory response and macrophages chemotaxis. Fn14 seems to be a biomarker for assessing disease severity in IMNM. In addition, Fn14 may also contribute to muscle injury repair.

Relief of Extracellular Matrix Deposition Repression by Downregulation of IRF1-Mediated TWEAK/Fn14 Signaling in Keloids.

Keloids represent a fibrotic disorder characterized by the excessive deposition of extracellular matrix (ECM). However, the mechanisms through which ECM deposition in keloids is regulated remain elusive. In this study, we found that the expression of both TWEAK and its cognate receptor Fn14 was significantly downregulated in keloids and that TWEAK/Fn14 signaling repressed the expression of ECM-related genes in keloid fibroblasts. The IRF1 gene was essential for this repression, and the TWEAK/Fn14 downstream transcription factor p65 directly bound to the promoter of the IRF1 gene and induced its expression. Furthermore, in patients with keloid, the expression of TWEAK and Fn14 was negatively correlated with that of ECM genes and positively correlated with that of IRF1. These observations indicate that relief of TWEAK/Fn14/IRF1-mediated ECM deposition repression contributes to keloid pathogenesis, and the identified mechanism and related molecules provide potential targets for keloid treatment in the future.

Status of TWEAK DNA methylation and mRNA expression in systemic lupus erythematosus.

OBJECTIVE: Draw upon research into the serum concentration, mRNA expression, and DNA methylation of TNF-like weak inducer of apoptosis (TWEAK) in the peripheral blood of systemic lupus erythematosus patients and healthy controls in an attempt to investigate the epigenetics associated with TWEAK in the pathogenesis of systemic lupus erythematosus (SLE). METHODS: A total of 178 SLE patients (SLE group) and 131 sex-age matched healthy controls (HC group) were recruited. Enzyme-linked immunosorbent assays (ELISA) was used to detect serum protein concentration of TWEAK. TWEAK mRNA expression was analyzed by Real-time quantitative reverse transcriptase-polymerase chain reaction (RT-PCR). Methylation levels of the promotor of TWEAK were measured using quantitative DNA methylation analysis on the MassARRAY spectrometry. RESULTS: Serum TWEAK concentrations were not statistically significant in SLE patients and HCs. Nevertheless, serum TWEAK concentrations were significantly lower in patients with renal involvement when compared to those without it. Serum TWEAK concentrations were reduced in clinically active patients (SLEDAI ≥ 10) compared with clinically stable patients (SLEDAI < 10). It was also significantly associated with SLEDAI. Compared with the HC group, the TWEAK mRNA expression in the SLE group was significantly lower. The global DNA methylation levels of TWEAK in the SLE group were observed to be significantly higher than the HC group. SLE patients with renal involvement, and the clinically active patients had higher TWEAK global methylation as well as exhibited variation in certain CpG island methylation. Furthermore, TWEAK methylation negatively correlated with TWEAK mRNA expression. CONCLUSION: This study suggests that TWEAK DNA methylation is a valuable as a focus for epigenetic studies because of it potentially influencing TWEAK gene expression in SLE patients. Aberrant DNA methylation of TWEAK may be involved in the initiation and development of SLE.

TWEAK-Fn14-RelB Signaling Cascade Promotes Stem Cell-like Features that Contribute to Post-Chemotherapy Ovarian Cancer Relapse.

Disease recurrence in high-grade serous ovarian cancer may be due to cancer stem-like cells (CSC) that are resistant to chemotherapy and capable of reestablishing heterogeneous tumors. The alternative NF-κB signaling pathway is implicated in this process; however, the mechanism is unknown. Here we show that TNF-like weak inducer of apoptosis (TWEAK) and its receptor, Fn14, are strong inducers of alternative NF-κB signaling and are enriched in ovarian tumors following chemotherapy treatment. We further show that TWEAK enhances spheroid formation ability, asymmetric division capacity, and expression of SOX2 and epithelial-to-mesenchymal transition genes VIM and ZEB1 in ovarian cancer cells, phenotypes that are enhanced when TWEAK is combined with carboplatin. Moreover, TWEAK in combination with chemotherapy induces expression of the CSC marker CD117 in CD117- cells. Blocking the TWEAK-Fn14-RelB signaling cascade with a small-molecule inhibitor of Fn14 prolongs survival following carboplatin chemotherapy in a mouse model of ovarian cancer. These data provide new insights into ovarian cancer CSC biology and highlight a signaling axis that should be explored for therapeutic development. IMPLICATIONS: This study identifies a unique mechanism for the induction of ovarian cancer stem cells that may serve as a novel therapeutic target for preventing relapse.

Conjugation of the Fn14 Ligand to a SMAC Mimetic Selectively Suppresses Experimental Squamous Cell Carcinoma in Mice.

The mimetic of SMAC induced cell death in cancers by depleting the inhibitor of apoptosis proteins. Recent studies showed that Fn14 is overexpressed in the cells of squamous cell carcinoma (SCC), providing a promising candidate target for selective antitumor therapy. In this study, we conjugated a small-molecule SMAC mimetic MV1 to the ligand of Fn14, TWEAK. Our results showed that TWEAK‒MV1 conjugate retained adequate binding specificity to Fn14-positive SCC cells in vitro and accumulated selectively in tumor tissue of cutaneous SCC xenografts mice after intraperitoneal administration. This conjugation compound exhibited remarkable effectiveness in suppressing tumor growth and extending overall survival without causing significant side effects in SCC xenograft mice. Moreover, TWEAK‒MV1 conjugate greatly enhanced both apoptotic and necroptotic cell death both in vitro and in vivo, accompanied by a cellular inhibitor of apoptosis proteins degradation as well as activation of receptor-interacting protein kinase. Taken together, our preclinical data suggested that the designed conjugation compound of TWEAK and MV1 might provide a potential therapeutic strategy for cutaneous SCC with improved antitumor efficacy and negligible toxicity.

Correlation of expression of silencing information regulator 2 related enzyme 1 and tumor necrosis factor-like weak inducer of apoptosis in articular effusion and knee osteoarthritis / 中国骨伤

OBJECTIVE@#To analyze the correlation between the expression of silencing information regulator 2 related enzyme 1 (SIRT1), tumor necrosis factor like weak inducer of apoptosis (TWEAK) and knee osteoarthritis.@*METHODS@#Total of 103 patients with knee joint (knee osteoarthritis group) from February 2019 to August 2021 were selected including 40 males and 63 females with an average age of (62.02±6.09) years;according to the modified Mankin score, 103 patients were divided into mild group (Mankin score 1-4 points, 31 cases) and moderate group (Mankin score 5-8 points, 40 cases) and severe group (Mankin score ≥9, 32 cases). Another 105 physical examination volunteers were selected as the control group including 46 males and 59 females with an average age of (62.11±6.34) years old. The levels of SIRT1 and TWEAK in articular effusion and serum were detected in the knee osteoarthritis group, while serum SIRT1 and TWEAK were detected in the control group only. The relationship between SIRT1, TWEAK and the occurrence and disease of knee osteoarthritis were analyzed.@*RESULTS@#Articular cavity fluid TWEAK, serum TWEAK, CRP, IL-6, IL-1β, white blood cell count and ESR were higher than those in the control group(P<0.05), articular cavity fluid SIRT1 and serum SIRT1 were lower than those in the control group(P<0.05). TWEAK level in the severe group was higher than that in the moderate and mild groups(P<0.05), SIRT1 was lower than that in the moderate and mild groups (P<0.05). The level of SIRT1 in articular cavity effusion was positively correlated with the serum level of SIRT1 (P<0.05), and negatively correlated with CRP, IL-6, IL-1β, white blood cell count, modified Mankin score and ESR (P<0.05). TWEAK level in articular cavity fluid was positively correlated with serum TWEAK level (P<0.05), C-reactive protein(CRP), interleukin(IL)-6, IL-1β, white blood cell count, modified Mankin score and erythrocyte sedimentation rate(ESR) (P<0.05). Body mass index, undertaking heavy physical work, and articular cavity fluid TWEAK were risk factors for the occurrence of knee osteoarthritis(P<0.05), and articular cavity fluid SIRT1 was a protective factor for the occurrence of knee arthritis (P<0.05). The area under curve(AUC) of SIRT1 and TWEAK for knee osteoarthritis was 0.641 and 0.653, and the AUC of SIRT1 and TWEAK for knee osteoarthritis was 0.879, which was higher than SIRT1 and TWEAK alone (z=6.105 and 6.225, P<0.05).@*CONCLUSION@#The level of SIRT1 in articular fluid in patients with knee arthritis is decreased and the level of TWEAK is increased. Low SIRT1 and high TWEAK are associated with the onset and exacerbation of knee osteoarthritis.

TWEAK-Fn14 Axis Induces Calcium-Associated Autophagy and Cell Death To Control Mycobacterial Survival in Macrophages.

Autophagy is a natural defense mechanism that protects the host against pathogens. We previously demonstrated that mycobacterial infection upregulated tumor necrosis factor-like weak inducer of apoptosis (TWEAK) to promote autophagy and mycobacterial autophagosome maturation through activation of AMP-activated protein kinase (AMPK). Fibroblast growth factor-inducible 14 (Fn14) is the receptor of TWEAK. But the role of Fn14 in mycobacterial infection remains elusive. Herein, we observed increased expression of Fn14 in peripheral blood mononuclear cells of active tuberculosis (TB) patients. Downregulation of cellular Fn14 enhanced mycobacterial survival in macrophages. Conversely, Fn14 overexpression inhibited mycobacterial growth, suggesting that Fn14 can inhibit mycobacterial infection. The in vitro results revealed that TWEAK-promoted mycobacterial phagosome maturation is Fn14-dependent. We demonstrated that TWEAK-Fn14 signaling promotes oxidative stress to enhance the expression of stromal interaction molecule 1 (STIM1) and its activation of the Ca2+ channel ORAI1. Elevated calcium influx stimulated the activation of CaMCCK2 (calcium/calmodulin-dependent protein kinase kinase 2) and its downstream effector AMPK, thus inducing autophagy in early infection. Persistently TWEAK-Fn14 signaling caused cell death in late infection by reducing mitochondrial membrane potential, leading to mitochondrial ROS accumulation, and activating cell death-associated proteins. Genetic Fn14 deficiency or TWEAK blockers decreased oxidative stress-induced calcium influx, thus suppressing autophagy and cell death in mycobacteria-infected macrophages, and resulting in elevated mycobacterial survival. We propose that the TWEAK-Fn14 axis and calcium influx could be manipulated for anti-TB therapeutic purposes. Our results offer a new molecular machinery to understand the association between the TWEAK-Fn14 axis, calcium influx, and mycobacterial infection. IMPORTANCE Tuberculosis remains a major cause of morbidity and mortality worldwide. We previously demonstrated a relationship between TWEAK and activation of the autophagic machinery, which promotes anti-mycobacterial immunity. The TWEAK-Fn14 axis is multi-functional and involved in the pathogenesis of many diseases, thus blockade of TWEAK-Fn14 axis has been considered as a potential therapeutic target. Here, we demonstrated that the TWEAK-Fn14 axis plays a novel role in anti-mycobacterial infection by regulating calcium-associated autophagy. Persistently, TWEAK-Fn14 signaling caused cell death in late infection by reducing mitochondrial membrane potential, leading to mitochondrial ROS accumulation, and activating cell death-associated proteins. TWEAK blocker or Fn14 deficiency could suppress oxidative stress and calcium-associated autophagy, resulting in elevated mycobacterial survival. We propose that the TWEAK-Fn14 axis and calcium influx could be manipulated for anti-TB therapeutic purposes. This study offers a new molecular machinery to understand the association between the TWEAK-Fn14 axis, calcium influx, and mycobacterial infection.

Proteolytically generated soluble Tweak Receptor Fn14 is a blood biomarker for γ-secretase activity.

Fn14 is a cell surface receptor with key functions in tissue homeostasis and injury but is also linked to chronic diseases. Despite its physiological and medical importance, the regulation of Fn14 signaling and turnover is only partly understood. Here, we demonstrate that Fn14 is cleaved within its transmembrane domain by the protease γ-secretase, resulting in secretion of the soluble Fn14 ectodomain (sFn14). Inhibition of γ-secretase in tumor cells reduced sFn14 secretion, increased full-length Fn14 at the cell surface, and enhanced TWEAK ligand-stimulated Fn14 signaling through the NFκB pathway, which led to enhanced release of the cytokine tumor necrosis factor. γ-Secretase-dependent sFn14 release was also detected ex vivo in primary tumor cells from glioblastoma patients, in mouse and human plasma and was strongly reduced in blood from human cancer patients dosed with a γ-secretase inhibitor prior to chimeric antigen receptor (CAR)-T-cell treatment. Taken together, our study demonstrates a novel function for γ-secretase in attenuating TWEAK/Fn14 signaling and suggests the use of sFn14 as an easily measurable pharmacodynamic biomarker to monitor γ-secretase activity in vivo.