A proliferation-inducing ligand (APRIL) is a ligand of the tumor necrosis factor (TNF) family that stimulates tumor cell growth in vitro and in vivo. Expression of APRIL is highly upregulated in many tumors including colon and prostate carcinomas. Here we identify B cell maturation antigen (BCMA) and transmembrane activator and calcium modulator and cyclophilin ligand (CAML) interactor (TACI), two predicted members of the TNF receptor family, as receptors for APRIL. APRIL binds BCMA with higher affinity than TACI. A soluble form of BCMA, which inhibits the proliferative activity of APRIL in vitro, decreases tumor cell proliferation in nude mice. Growth of HT29 colon carcinoma cells is blocked when mice are treated once per week with the soluble receptor. These results suggest an important role for APRIL in tumorigenesis and point towards a novel anticancer strategy.

BACKGROUND Ovarian cancer is the most common gynecological malignancies in women, with high mortality rates worldwide. Tumor necrosis factor-related apoptosis-inducing ligand (TRAIL) is a member of the tumor necrosis factor (TNF) superfamily which preferentially induces apoptosis of cancer cells. However, acquired resistance to TRAIL hampers its therapeutic application. Identification of compounds that sensitize cancer cells to TRAIL is vital in combating resistance to TRAIL. The effect of kaempferol, a flavonoid enhancing TRAIL-induced apoptosis in ovarian cancer cells, was investigated in this study. MATERIAL AND METHODS The cytotoxic effects of TRAIL (25 ng/mL) and kaempferol (20-100 µM) on human ovarian cancer cells OVCAR-3 and SKOV-3 were assessed. Effect of kaempferol on the expression patterns of cell survival proteins (Bcl-xL, Bcl-2, survivin, XIAP, c-FLIP) and apoptotic proteins (caspase-3, caspase-8, caspase-9, Bax) were studied. The influence of kaempferol on expression of DR4 and DR5 death receptors on the cell surface and protein and mRNA levels was also analyzed. Apoptosis following silencing of DR5 and CHOP by small interfering RNA (siRNA), and activation of MAP kinases were analyzed as well. RESULTS Kaempferol enhanced apoptosis and drastically up-regulated DR4, DR5, CHOP, JNK, ERK1/2, p38 and apoptotic protein expression with decline in the expression of anti-apoptotic proteins. Further transfection with siRNA specific to CHOP and DR5 indicated the involvement of CHOP in DR5 up-regulation and also the contribution of DR5 in kaempferol-enhanced TRAIL-induced apoptosis. CONCLUSIONS Kaempferol sensitized ovarian cancer cells to TRAIL-induced apoptosis via up-regulation of DR4 and DR5 through ERK/JNK/CHOP pathways.

Low 25(OH)D has been associated with dyslipidemia, insulin resistance and inflammation in both general and HIV-infected (mostly treated) populations. We investigated these associations in antiretroviral-naïve HIV-infected persons.

Hip OF carries the highest morbidity and mortality. Previous studies revealed that individual genes/loci in the Tumor Necrosis Factor (TNF)-Related Apoptosis-Inducing Ligand (TRAIL) pathway were associated with bone metabolism. This study aims to verify the potential association between hip OF and TRAIL pathway.

Particulate matter (PM2.5) is a risk factor for organ injury and disease progression, such as lung, brain and liver. However, its effects on renal injury and the underlying molecular mechanism have not been understood. The inactive rhomboid protein 2 (iRhom2), also known as rhomboid family member 2 (Rhbdf2), is a necessary modulator for shedding of tumor necrosis factor-α (TNF-α) in immune cells, and has been explored in the pathogenesis of chronic renal diseases. In the present study, we found that compared to the wild type (iRhom2+/+) mice, iRhom2 knockout (iRhom2-/-) protected PM2.5-exposed mice from developing severe renal injury, accompanied with improved renal pathological changes and functions. iRhom2-/- mice exhibited reduced inflammatory response, as evidenced by the reduction of interleukin 1β (IL-1β), IL-6, tumor necrosis factor-α (TNF-α) and IL-18 in kidney samples, which might be, at least partly, through inactivating TNF-α converting enzyme/TNF-α receptors (TACE/TNFRs) and inhibitor of α/nuclear factor κ B (IκBα/NF-κB) signaling pathways. In addition, oxidative stress was also restrained by iRhom2-/- in kidney of PM2.5-exposed mice by enhancing heme oxygenase/nuclear factor erythroid 2-related factor 2 (HO-1/Nrf-2) expressions, and reducing phosphorylated c-Jun N-terminal kinase (JNK). In vitro, blockage of HO-1 or Nrf-2 rescued the inflammatory response and oxidative stress that were reduced by iRhom2 knockdown in PM2.5-incubated RAW264.7 cells. Similar results were observed in JNK activator-treated cells. Taken together, our findings indicated that iRhom2 played an essential role in regulating PM2.5-induced chronic renal damage, thus revealing a potential target for preventing chronic kidney diseases development.

Synovial fibroblasts (SF) were reported to produce B cell activating factor (BAFF) in response to stimulation with interferon-γ (IFN-γ) or tumor necrosis factor (TNF). However, the influence of these pro-inflammatory cytokines on other receptors/ligands of the TNF superfamily or associated cytokine receptors in SF has not been investigated yet. Here we show the differential regulation of BAFF (CD257), Fn14 (CD266), TACI (CD267), BAFF-R (CD268), BCMA (CD269), CD40 ligand (CD40L, CD154), IFN-γR (CD119), Leptin receptor (ObR, CD295), VCAM-1 (CD106) and membrane TGF-β in isolated SF and the impact of IFN-γ/TNF co-incubation on proliferation, IL-6 and IL-8 production. In addition, the impact of differentially stimulated SF on B cell survival in co-cultures was assessed. Surface cytokines and cytokine receptors were detected by flow cytometry. Soluble cytokine receptors and cytokines were quantified by ELISA. Proliferation was assessed by cell titer blue. Murine B cell survival in fibroblast/ B cell co-cultures was determined by annexin V/propidium iodide staining and flow cytometry. IFN-γ together with TNF synergistically and significantly increased the cell surface levels of BAFF, Fn14, TACI, BAFF-R, BCMA, CD40L, ObR and IFN-γR in rheumatoid arthritis SF after 72 h incubation. Soluble BAFF was only induced by IFN-γ and inhibited by TNF. Addition of TWEAK had no influence on proliferation or IL-8 production but decreased TNF-induced IL-6 production, whereas APRIL, BAFF and leptin did not modulate TNF or TNF/IFN-γ-induced proliferation or cytokine production. Proliferation was increased by TNF and further enhanced by the addition of IFN-γ. In co-culture experiments, SF stimulated with TNF/IFN but not TNF or IFN-γ alone increased shedding of VCAM-1 and expression of membrane TGFβ, which was associated with reduced survival of murine B cells. IFN-γ and TNF regulate the expression of TNF family member cytokines and associated receptors. Ligation of IFN-γR and Fn14 under pro-inflammatory conditions modulated IL-6/IL-8 production and proliferation. In B cell/SF co-cultures, the combination of TNF/IFN reduced B cell survival possibly via enhanced VCAM-1 shedding and/or increased TGF-β production. IFN-γ is necessary for the observed effects on B cell survival and SF cytokine production and emphasizes its anti-inflammatory role in rheumatoid arthritis.

Human Fas ligand (L) (CD95L) and tumor necrosis factor (TNF)-alpha undergo metalloproteinase-mediated proteolytic processing in their extracellular domains resulting in the release of soluble trimeric ligands (soluble [s]FasL, sTNF-alpha) which, in the case of sFasL, is thought to be implicated in diseases such as hepatitis and AIDS. Here we show that the processing of sFasL occurs between Ser126 and Leu127. The apoptotic-inducing capacity of naturally processed sFasL was reduced by >1,000-fold compared with membrane-bound FasL, and injection of high doses of recombinant sFasL in mice did not induce liver failure. However, soluble FasL retained its capacity to interact with Fas, and restoration of its cytotoxic activity was achieved both in vitro and in vivo with the addition of cross-linking antibodies. Similarly, the marginal apoptotic activity of recombinant soluble TNF-related apoptosis-inducing ligand (sTRAIL), another member of the TNF ligand family, was greatly increased upon cross-linking. These results indicate that the mere trimerization of the Fas and TRAIL receptors may not be sufficient to trigger death signals. Thus, the observation that sFasL is less cytotoxic than membrane-bound FasL may explain why in certain types of cancer, systemic tissue damage is not detected, even though the levels of circulating sFasL are high.

Objective: This study aimed to investigate the molecular mechanism of tumor necrosis factor (TNF) superfamily-related genes and potential therapeutic drugs for glioblastoma multiforme (GBM) patients based on transcriptome and epigenome. Methods: Gene expression data, corresponding clinical data, and methylation data of GBM samples and normal samples in the TCGA-GBM and GTEx datasets were downloaded. The TNF-related genes were obtained, respectively, from two groups in the TCGA dataset. Then, the TNF-related differentially expressed genes (DEGs) were investigated between two groups, followed by enrichment analysis. Moreover, TNF superfamily-related gene expression and upstream methylation regulation were investigated to explore candidate genes and the prognostic model. Finally, the protein expression level of candidate genes was performed, followed by drug prediction analysis. Results: A total of 41 DEGs including 4 ligands, 18 receptors, and 19 downstream signaling molecules were revealed between two groups. These DEGs were mainly enriched in pathways like TNF signaling and functions like response to TNF. A total of 5 methylation site-regulated prognosis-related genes including TNF Receptor Superfamily Member (TNFRSF) 12A, TNFRSF11B, and CD40 were explored. The prognosis model constructed by 5 genes showed a well-prediction effect on the current dataset and verification dataset. Finally, drug prediction analysis showed that zoledronic acid (ZA)-TNFRSF11B was the unique drug-gene relation in both two databases. Conclusion: Methylation-driven gene TNFRSF12A might participate in the development of GBM via response to the TNF biological process and TNF signaling pathway and significantly associated with prognosis. ZA that targets TNFRSF11B expression might be a potential effective drug for clinical treatment of GBM.

The zinc finger protein 36-like 2, ZFP36L2, is a member of a small family of RNA-binding proteins composed by ZFP36 (also known as tristetraprolin, TTP), ZFP36L1 and ZFP36L2 in humans, with corresponding murine orthologs. These proteins bind to adenine uridine-rich element (ARE) in the 3'untranslated region of target messenger RNA and stimulate target degradation. ZFP36 functions as an anti-inflammatory modulator in murine models of inflammatory diseases by down-regulating the production of inflammatory cytokines such as tumor necrosis factor-α. However, how ZFP36L1 and ZFP36L2 alter the function of CD4+ T cells is not completely understood. We addressed this issue by searching for the target genes of ZFP36L2 by comprehensive transcriptome analysis. We observed that ZFP36L2 is highly expressed in naïve CD4+ T cells; however, when CD4+ T cells are stimulated through their T cell receptors, ZFP36L2 expression is rapidly reduced in both humans and mice. Among CD4+ T cell populations, the expression levels of ZFP36L2 in regulatory T cells (Tregs) were significantly lower than those in naïve or effector CD4+ T cells. RNA-sequence analysis revealed that the forced expression of ZFP36L2 decreased Ikzf2 (encoding Helios) expression in Foxp3+ Tregs and inhibited the ability of induced Tregs (iTregs). ZFP36L2 directly bound to and destabilized the 3'untranslated region of Ikzf2 mRNA, which contains AU-rich elements. These results indicate that ZFP36L2 reduces the expression of Ikzf2 and suppresses iTreg function, raising the interesting possibility that the inhibition of ZFP36L2 in iTregs could be a therapeutic strategy for autoimmune diseases.

Sporothrix schenckii is a member of the Sporothrix pathogenic clade and one of the most common etiological agents of sporotrichosis, a subcutaneous fungal infection that affects both animal and human beings. Like other fungal pathogens, the Sporothrix cell wall is composed of structural polysaccharides and glycoproteins that are covalently modified with both N-linked and O-linked glycans. Thus far, little is known about the N-linked glycosylation pathway in this organism or its contribution to cell wall composition and interaction with the host. Here, we silenced ROT2, which encodes the catalytic subunit of the endoplasmic reticulum α-glucosidase II, a processing enzyme key for the N-linked glycan core processing. Silencing of ROT2 led to the accumulation of the Glc2Man9GlcNAC2 glycan core at the cell wall and a reduction in the total content of N-linked glycans found in the wall. However, the highly silenced mutants showed a compensatory mechanism with increased content of cell wall O-linked glycans. The phenotype of mutants with intermediate levels of ROT2 silencing was more informative, as they showed changes in the cell wall composition and exposure of β-1.3-glucans and chitin at the cell surface. Furthermore, the ability to stimulate cytokine production by human mononuclear cells was affected, along with the phagocytosis by human monocyte-derived macrophages, in a mannose receptor-, complement receptor 3-, and TLR4-dependent stimulation. In an insect model of experimental sporotrichosis, these mutant cells showed virulence attenuation. In conclusion, S. schenckii ROT2 is required for proper N-linked glycosylation, cell wall organization and composition, and interaction with the host.

The rapidly spreading Coronavirus Disease (COVID-19) pandemic, caused by the severe acute respiratory syndrome coronavirus (SARS-CoV-2), represents an unprecedented serious challenge to the global public health community. The extremely rapid international spread of the disease with significant morbidity and mortality made finding possible therapeutic interventions a global priority. While approved specific antiviral drugs against SARS-CoV-2 are still lacking, a large number of existing drugs are being explored as a possible treatment for COVID-19 infected patients. Recent publications have re-examined the use of Chloroquine (CQ) and/or Hydroxychloroquine (HCQ) as a potential therapeutic option for these patients. In an attempt to explore the evidence that supports their use in COVID-19 patients, we comprehensively reviewed the previous studies which used CQ or HCQ as an antiviral treatment. Both CQ and HCQ demonstrated promising in vitro results, however, such data have not yet been translated into meaningful in vivo studies. While few clinical trials have suggested some beneficial effects of CQ and HCQ in COVID-19 patients, most of the reported data are still preliminary. Given the current uncertainty, it is worth being mindful of the potential risks and strictly rationalise the use of these drugs in COVID-19 patients until further high quality randomized clinical trials are available to clarify their role in the treatment or prevention of COVID-19.