bims-tunefa Biomed News
on Tumor necrosis factor superfamily and post-translational modifications
Issue of 2020‒11‒08
fifteen papers selected by
John Silke
Walter and Eliza Hall Institute of Medical Research

  1. Nucleic Acids Res. 2020 Nov 02. pii: gkaa941. [Epub ahead of print]
    Ayyappan V, Wat R, Barber C, Vivelo CA, Gauch K, Visanpattanasin P, Cook G, Sazeides C, Leung AKL.
      ADP-ribosylation is a protein modification responsible for biological processes such as DNA repair, RNA regulation, cell cycle and biomolecular condensate formation. Dysregulation of ADP-ribosylation is implicated in cancer, neurodegeneration and viral infection. We developed ADPriboDB ( to facilitate studies in uncovering insights into the mechanisms and biological significance of ADP-ribosylation. ADPriboDB 2.0 serves as a one-stop repository comprising 48 346 entries and 9097 ADP-ribosylated proteins, of which 6708 were newly identified since the original database release. In this updated version, we provide information regarding the sites of ADP-ribosylation in 32 946 entries. The wealth of information allows us to interrogate existing databases or newly available data. For example, we found that ADP-ribosylated substrates are significantly associated with the recently identified human protein interaction networks associated with SARS-CoV-2, which encodes a conserved protein domain called macrodomain that binds and removes ADP-ribosylation. In addition, we create a new interactive tool to visualize the local context of ADP-ribosylation, such as structural and functional features as well as other post-translational modifications (e.g. phosphorylation, methylation and ubiquitination). This information provides opportunities to explore the biology of ADP-ribosylation and generate new hypotheses for experimental testing.
  2. Chem Sci. 2020 Apr 07. 11(13): 3474-3486
    Steinebach C, Ng YLD, Sosič I, Lee CS, Chen S, Lindner S, Vu LP, Bricelj A, Haschemi R, Monschke M, Steinwarz E, Wagner KG, Bendas G, Luo J, Gütschow M, Krönke J.
      Cyclin-dependent kinase 6 (CDK6) is an important regulator of the cell cycle. Together with CDK4, it phosphorylates and inactivates retinoblastoma (Rb) protein. In tumour cells, CDK6 is frequently upregulated and CDK4/6 kinase inhibitors like palbociclib possess high activity in breast cancer and other malignancies. Besides its crucial catalytic function, kinase-independent roles of CDK6 have been described. Therefore, targeted degradation of CDK6 may be advantageous over kinase inhibition. Proteolysis targeting chimeras (PROTACs) structurally based on the cereblon (CRBN) ligand thalidomide have recently been described to degrade the targets CDK4/6. However, CRBN-based PROTACs have several limitations including the remaining activity of immunomodulatory drugs (IMiDs) on Ikaros transcription factors as well as CRBN inactivation as a resistance mechanism in cancer. Here, we systematically explored the chemical space of CDK4/6 PROTACs by addressing different E3 ligases and connecting their respective small-molecule binders via various linkers to palbociclib. The spectrum of CDK6-specific PROTACs was extended to von Hippel Lindau (VHL) and cellular inhibitor of apoptosis protein 1 (cIAP1) that are essential for most cancer cells and therefore less likely to be inactivated. Our VHL-based PROTAC series included compounds that were either specific for CDK6 or exhibited dual activity against CDK4 and CDK6. IAP-based PROTACs caused a combined degradation of CDK4/6 and IAPs resulting in synergistic effects on cancer cell growth. Our new degraders showed potent and long-lasting degrading activity in human and mouse cells and inhibited proliferation of several leukemia, myeloma and breast cancer cell lines. In conclusion, we show that VHL- and IAP-based PROTACs are an attractive approach for targeted degradation of CDK4/6 in cancer.
  3. Semin Cell Dev Biol. 2020 Oct 29. pii: S1084-9521(20)30163-4. [Epub ahead of print]
    Vince JE.
  4. Cytokine. 2020 Nov 02. pii: S1043-4666(20)30373-2. [Epub ahead of print] 155357
    Ehst B, Wang Z, Leitenberger J, McClanahan D, De La Torre R, Sawka E, Ortega-Loayza AG, Strunck J, Greiling T, Simpson E, Liu Y.
      IL-23 is an inflammatory cytokine that plays an essential role in Th17 immunity by enhancing Th17 cell proliferation and survival, and Th17 cytokine production. IL-23 has pathogenic roles in the development of Th17-mediated inflammatory diseases including psoriasis. Despite successful treatment of psoriasis by blocking IL-23, the regulation of IL-23 expression in psoriasis patients is largely unknown. Dendritic cells are generally considered to be the primary source of IL-23 in psoriasis. While high levels of IL-23 are found in psoriatic epidermis, IL-23 expression in psoriatic keratinoctyes remains a controversial issue. In this study, we demonstrated that IL-23 production is induced by a combination of TNFα and IL-17A in human keratinocytes. Additionally, this IL-23 induction by TNFα and IL-17A is further increased in psoriatic keratinocytes and is enhanced by EGFR signaling. Although IL-23 is also robustly induced by toll-like receptor agonists in dendritic cells and macrophages, IL-23 expression in these cell types is not regulated by TNFα, IL-17A, and EGFR signaling. Given that IL-23 is essential for maintaining Th17 activation, IL-23 induction by TNFα, IL-17A, and EGF in keratinocytes could play an important pathological role in psoriasis pathogenesis as well as the cutaneous rash associated with EGFR inhibition therapy.
    Keywords:  Epidermal growth factor (EGF); Interleukin 17A (IL-17A); Keratinocytes; Psoriasis; Tumor necrosis factor alpha (TNFα)
  5. Endocrinology. 2020 Dec 01. pii: bqaa185. [Epub ahead of print]161(12):
    Eldeeb MA, Zorca CE, Fahlman RP.
      In mammals, protein degradation is mediated selectively by the ubiquitin proteasome system (UPS) and the autophagic-lysosomal system. Over the past decades, N-degron pathways have been shown to be responsible for the selective degradation of proteins that harbor destabilizing N-terminal motifs. Recent studies have employed these pathways in the development of proteolysis targeting chimeras (PROTACs) composed of a degradation module linked to a substrate recognition domain to target proteins encoded by cancer-related genes for proteasomal destruction. Herein we provide an overview of PROTACs in the context of the N-degron concept and address the application of this technique to curb the migration and invasion of cancer cells, with a focus on the far-reaching potential of exploiting N-degron pathways for therapeutic purposes.
    Keywords:  N-degron; N-end rule; PROTACS; apoptosis; cancer; proteasome; protein degradation; proteolysis; ubiquitin
  6. Cell Commun Signal. 2020 Nov 04. 18(1): 176
    Maksymowicz M, Miączyńska M, Banach-Orłowska M.
      BACKGROUND: Lymphotoxin β receptor (LTβR) is a member of tumor necrosis factor receptor (TNFR) superfamily which regulates the immune response. At the cellular level, upon ligand binding, the receptor activates the pro-inflammatory NF-κB and AP-1 pathways. Yet, the intracellular distribution of LTβR, the routes of its endocytosis and their connection to the signaling activation are not characterized. Here, we investigated the contribution of LTβR internalization to its signaling potential.METHODS: Intracellular localization of LTβR in unstimulated and stimulated cells was analyzed by confocal microscopy. Endocytosis impairment was achieved through siRNA- or CRISPR/Cas9-mediated depletion, or chemical inhibition of proteins regulating endocytic routes. The activation of LTβR-induced signaling was examined. The levels of effector proteins of the canonical and non-canonical branches of the NF-κB pathway, and the phosphorylation of JNK, Akt, ERK1/2, STAT1 and STAT3 involved in diverse signaling cascades, were measured by Western blotting. A transcriptional response to LTβR stimulation was assessed by qRT-PCR analysis.
    RESULTS: We demonstrated that LTβR was predominantly present on endocytic vesicles and the Golgi apparatus. The ligand-bound pool of the receptor localized to endosomes and was trafficked towards lysosomes for degradation. Depletion of regulators of different endocytic routes (clathrin-mediated, dynamin-dependent or clathrin-independent) resulted in the impairment of LTβR internalization, indicating that this receptor uses multiple entry pathways. Cells deprived of clathrin and dynamins exhibited enhanced activation of canonical NF-κB signaling represented by increased degradation of IκBα inhibitor and elevated expression of LTβR target genes. We also demonstrated that clathrin and dynamin deficiency reduced to some extent LTβR-triggered activation of the non-canonical branch of the NF-κB pathway.
    CONCLUSIONS: Our work shows that the impairment of clathrin- and dynamin-dependent internalization amplifies a cellular response to LTβR stimulation. We postulate that receptor internalization restricts responsiveness of the cell to subthreshold stimuli. Video Abstract.
    Keywords:  Clathrin-independent endocytosis; Clathrin-mediated endocytosis; Dynamin; Endocytosis; Lymphotoxin β receptor; NF-κB signaling; Receptor internalization
  7. bioRxiv. 2020 Oct 29. pii: 2020.10.29.361048. [Epub ahead of print]
    Karki R, Sharma BR, Tuladhar S, Williams EP, Zalduondo L, Samir P, Zheng M, Sundaram B, Banoth B, Malireddi RKS, Schreiner P, Neale G, Vogel P, Webby R, Jonsson CB, Kanneganti TD.
      The COVID-19 pandemic has caused significant morbidity and mortality. Currently, there is a critical shortage of proven treatment options and an urgent need to understand the pathogenesis of multi-organ failure and lung damage. Cytokine storm is associated with severe inflammation and organ damage during COVID-19. However, a detailed molecular pathway defining this cytokine storm is lacking, and gaining mechanistic understanding of how SARS-CoV-2 elicits a hyperactive inflammatory response is critical to develop effective therapeutics. Of the multiple inflammatory cytokines produced by innate immune cells during SARS-CoV-2 infection, we found that the combined production of TNF-α and IFN-γ specifically induced inflammatory cell death, PANoptosis, characterized by gasdermin-mediated pyroptosis, caspase-8-mediated apoptosis, and MLKL-mediated necroptosis. Deletion of pyroptosis, apoptosis, or necroptosis mediators individually was not sufficient to protect against cell death. However, cells deficient in both RIPK3 and caspase-8 or RIPK3 and FADD were resistant to this cell death. Mechanistically, the STAT1/IRF1 axis activated by TNF-α and IFN-γ co-treatment induced iNOS for the production of nitric oxide. Pharmacological and genetic deletion of this pathway inhibited pyroptosis, apoptosis, and necroptosis in macrophages. Moreover, inhibition of PANoptosis protected mice from TNF-α and IFN-γ-induced lethal cytokine shock that mirrors the pathological symptoms of COVID-19. In vivo neutralization of both TNF-α and IFN-γ in multiple disease models associated with cytokine storm showed that this treatment provided substantial protection against not only SARS-CoV-2 infection, but also sepsis, hemophagocytic lymphohistiocytosis, and cytokine shock models, demonstrating the broad physiological relevance of this mechanism. Collectively, our findings reveal that blocking the COVID-19 cytokine-mediated inflammatory cell death signaling pathway identified in this study may benefit patients with COVID-19 or other cytokine storm-driven syndromes by limiting inflammation and tissue damage. The findings also provide a molecular and mechanistic description for the term cytokine storm. Additionally, these results open new avenues for the treatment of other infectious and autoinflammatory diseases and cancers where TNF-α and IFN-γ synergism play key pathological roles.
  8. Nature. 2020 Nov 04.
    Conlon TM, John-Schuster G, Heide D, Pfister D, Lehmann M, Hu Y, Ertüz Z, Lopez MA, Ansari M, Strunz M, Mayr C, Ciminieri C, Costa R, Kohlhepp MS, Guillot A, Günes G, Jeridi A, Funk MC, Beroshvili G, Prokosch S, Hetzer J, Verleden SE, Alsafadi H, Lindner M, Burgstaller G, Becker L, Irmler M, Dudek M, Janzen J, Goffin E, Gosens R, Knolle P, Pirotte B, Stoeger T, Beckers J, Wagner D, Singh I, Theis FJ, de Angelis MH, O'Connor T, Tacke F, Boutros M, Dejardin E, Eickelberg O, Schiller HB, Königshoff M, Heikenwalder M, Yildirim AÖ.
      Lymphotoxin β-receptor (LTβR) signalling promotes lymphoid neogenesis and the development of tertiary lymphoid structures1,2, which are associated with severe chronic inflammatory diseases that span several organ systems3-6. How LTβR signalling drives chronic tissue damage particularly in the lung, the mechanism(s) that regulate this process, and whether LTβR blockade might be of therapeutic value have remained unclear. Here we demonstrate increased expression of LTβR ligands in adaptive and innate immune cells, enhanced non-canonical NF-κB signalling, and enriched LTβR target gene expression in lung epithelial cells from patients with smoking-associated chronic obstructive pulmonary disease (COPD) and from mice chronically exposed to cigarette smoke. Therapeutic inhibition of LTβR signalling in young and aged mice disrupted smoking-related inducible bronchus-associated lymphoid tissue, induced regeneration of lung tissue, and reverted airway fibrosis and systemic muscle wasting. Mechanistically, blockade of LTβR signalling dampened epithelial non-canonical activation of NF-κB, reduced TGFβ signalling in airways, and induced regeneration by preventing epithelial cell death and activating WNT/β-catenin signalling in alveolar epithelial progenitor cells. These findings suggest that inhibition of LTβR signalling represents a viable therapeutic option that combines prevention of tertiary lymphoid structures1 and inhibition of apoptosis with tissue-regenerative strategies.
  9. Trends Immunol. 2020 Oct 15. pii: S1471-4906(20)30234-9. [Epub ahead of print]
    Lee S, Channappanavar R, Kanneganti TD.
      The innate immune system acts as the first line of defense against pathogens, including coronaviruses (CoVs). Severe acute respiratory syndrome (SARS)-CoV and Middle East respiratory syndrome (MERS)-CoV are epidemic zoonotic CoVs that emerged at the beginning of the 21st century. The recently emerged virus SARS-CoV-2 is a novel strain of CoV that has caused the coronavirus 2019 (COVID-19) pandemic. Scientific advancements made by studying the SARS-CoV and MERS-CoV outbreaks have provided a foundation for understanding pathogenesis and innate immunity against SARS-CoV-2. In this review, we focus on our present understanding of innate immune responses, inflammasome activation, inflammatory cell death pathways, and cytokine secretion during SARS-CoV, MERS-CoV, and SARS-CoV-2 infection. We also discuss how the pathogenesis of these viruses influences these biological processes.
    Keywords:  COVID-19; MERS-CoV; MHV; PANoptosis; PANoptosome; RNA virus; SARS-CoV; SARS-CoV-2; cell death; coronavirus; cytokines; inflammasome; inflammation; innate immunity
  10. J Exp Med. 2020 Dec 07. pii: e20201562. [Epub ahead of print]217(12):
    Melero I, Berraondo P.
      4-1BB (CD137, TNFRSF9) mediates costimulatory signals important for activation and persistence of cytotoxic T lymphocytes. In this issue of JEM, Oda et al. ( report on a chimeric construction encompassing extracellular Fas and intracellular 4-1BB to dramatically improve adoptive T cell therapy.
  11. Cells. 2020 Nov 03. pii: E2407. [Epub ahead of print]9(11):
    Ellman DG, Lund MC, Nissen M, Nielsen PS, Sørensen C, Lester EB, Thougaard E, Jørgensen LH, Nedospasov SA, Andersen DC, Stubbe J, Brambilla R, Degn M, Lambertsen KL.
      Spinal cord injury (SCI) is a devastating condition consisting of an instant primary mechanical injury followed by a secondary injury that progresses for weeks to months. The cytokine tumor necrosis factor (TNF) plays an important role in the pathophysiology of SCI. We investigated the effect of myeloid TNF ablation (peripheral myeloid cells (macrophages and neutrophils) and microglia) versus central myeloid TNF ablation (microglia) in a SCI contusion model. We show that TNF ablation in macrophages and neutrophils leads to reduced lesion volume and improved functional outcome after SCI. In contrast, TNF ablation in microglia only or TNF deficiency in all cells had no effect. TNF levels tended to be decreased 3 h post-SCI in mice with peripheral myeloid TNF ablation and was significantly decreased 3 days after SCI. Leukocyte and microglia populations and all other cytokines (IL-1β, IL-2, IL-4, IL-5, IL-6, IL-10, IL-12, and IFNγ) and chemokines (CCL2, CCL5, and CXCL1) investigated, in addition to TNFR1 and TNFR2, were comparable between genotypes. Analysis of post-SCI signaling cascades demonstrated that the MAPK kinase SAPK/JNK decreased and neuronal Bcl-XL levels increased post-SCI in mice with ablation of TNF in peripheral myeloid cells. These findings demonstrate that peripheral myeloid cell-derived TNF is pathogenic in SCI.
    Keywords:  functional outcome; myeloid cells; spinal cord injury; tumor necrosis factor
  12. FEBS J. 2020 Nov 01.
    Johnston HE, Samant RS.
      Protein misfolding is a major driver of ageing-associated frailty and disease pathology. Although all cells possess multiple, well-characterised protein quality control systems to mitigate the toxicity of misfolded proteins, how they are integrated to maintain protein homeostasis ('proteostasis') in health-and how their dis-integration contributes to disease-is still an exciting and fast-paced area of research. Under physiological conditions, the predominant route for misfolded protein clearance involves ubiquitylation and proteasome-mediated degradation. When the capacity of this route is overwhelmed-as happens during conditions of acute environmental stress, or chronic ageing-related decline-alternative routes for protein quality control are activated. In this review, we summarise our current understanding of how proteasome-targeted misfolded proteins are re-trafficked to alternative protein quality control routes such as juxta-nuclear sequestration and selective autophagy when the ubiquitin-proteasome system is compromised. We also discuss the molecular determinants of these alternative protein quality control systems, attempt to clarify distinctions between various cytoplasmic spatial quality control inclusion bodies (e.g., Q-bodies, p62-bodies, JUNQ, aggresomes, and aggresome-like induced structures 'ALIS'), and speculate on emerging concepts in the field that we hope will spur future research-with the potential to benefit the rational development of healthy ageing strategies.
    Keywords:  PQC; cancer; chaperone; heat shock protein; neurodegeneration; protein aggregate; protein degradation; protein triage; ubiquitin; ubiquitination
  13. Elife. 2020 Nov 06. pii: e61965. [Epub ahead of print]9
    Zhao Z, Zhang Z, Li J, Dong Q, Xiong J, Li Y, Lan M, Li G, Zhu B.
      Transcriptional memory allows certain genes to respond to previously experienced signals more robustly. However, whether and how the key proinflammatory cytokine TNF-α mediates transcriptional memory are poorly understood. Using HEK293F cells as a model system, we report that sustained TNF-α stimulation induces transcriptional memory dependent on TET enzymes. The hypomethylated status of transcriptional regulatory regions can be inherited, facilitating NF-κB binding and more robust subsequent activation. A high initial methylation level and CpG density around κB sites are correlated with the functional potential of transcriptional memory modules. Interestingly, the CALCB gene, encoding the proven migraine therapeutic target CGRP, exhibits the best transcriptional memory. A neighboring primate-specific endogenous retrovirus stimulates more rapid, more strong and at least 100-fold more sensitive CALCB induction in subsequent TNF-α stimulation. Our study reveals that TNF-α-mediated transcriptional memory is governed by active DNA demethylation and greatly sensitizes memory genes to much lower doses of inflammatory cues.
    Keywords:  chromosomes; gene expression; human
  14. Paediatr Anaesth. 2020 Nov 05.
    Chatterjee D, Yaster M, Lockman JL, Glass NL, Schreiner MS, L J, Sinskey , Fiadjoe JE.
      Scientific presentations, usually given with slide presentation software such as PowerPointTM , are the most common method for disseminating knowledge to students and peers. Unfortunately, many are boring, text-heavy, bullet point-riddled data dumps, with animations or cartoons that obscure or distract rather than clarify the message. These presentations, which we have all sat through and/or delivered, are often so dull that they are referred to as "death by PowerPoint™." In this paper, the authors intend to impart basic techniques for organizing and communicating information in the most effective, engaging, and actionable ways possible. We focus on three processes: generating ideas and outlining a talk, creating visually appealing uncluttered slides, and delivering an inspiring, practice-changing presentation. We also discuss considerations for a virtual presentation. We believe that even experienced speakers could benefit from reflecting on these recommendations and editing their slide presentations for clarity and simplicity.
    Keywords:  PowerPointTM; lectures; presentation skills; scientific presentations; slide show; video conference; visual display design