Pharmacological targeting of the transcription factor SOX18 delays breast cancer in mice.

Pharmacological targeting of transcription factors holds great promise for the development of new therapeutics, but strategies based on blockade of DNA binding, nuclear shuttling, or individual protein partner recruitment have yielded limited success to date. Transcription factors typically engage in complex interaction networks, likely masking the effects of specifically inhibiting single protein-protein interactions. Here, we used a combination of genomic, proteomic and biophysical methods to discover a suite of protein-protein interactions involving the SOX18 transcription factor, a known regulator of vascular development and disease. We describe a small-molecule that is able to disrupt a discrete subset of SOX18-dependent interactions. This compound selectively suppressed SOX18 transcriptional outputs in vitro and interfered with vascular development in zebrafish larvae. In a mouse pre-clinical model of breast cancer, treatment with this inhibitor significantly improved survival by reducing tumour vascular density and metastatic spread. Our studies validate an interactome-based molecular strategy to interfere with transcription factor activity, for the development of novel disease therapeutics

IL-1β is an innate immune sensor of microbial proteolysis

Interleukin-1β (IL-1β) is a key proinflammatory cytokine that drives antimicrobial immune responses. IL-1β is aberrantly activated in autoimmune diseases, and IL-1β inhibitors are used as therapeutic agents to treat patients with certain autoimmune disorders. Review of postmarketing surveillance of patients receiving IL-1β inhibitors found a disproportionate reporting of invasive infections by group A Streptococcus (GAS). IL-1β inhibition increased mouse susceptibility to GAS infection, but IL-1β was produced independent of canonical inflammasomes. Newly synthesized IL-1β has an amino-terminal prodomain that blocks signaling activity, which is usually proteolytically removed by caspase-1, a protease activated within the inflammasome structure. In place of host caspases, the secreted GAS cysteine protease SpeB generated mature IL-1β. During invasive infection, GAS isolates may acquire pathoadaptive mutations eliminating SpeB expression to evade detection by IL-1β. Pharmacological IL-1β inhibition alleviates this selective pressure, allowing invasive infection by nonpathoadapted GAS. Thus, IL-1β is a sensor that directly detects pathogen-associated proteolysis through an independent pathway operating in parallel with host inflammasomes. Because IL-1β function is maintained across species, yet cleavage by caspases does not appear to be, detection of microbial proteases may represent an ancestral system of innate immune regulation

MCC950 reduces autophagy and improves cognitive function by inhibiting NLRP3-dependent neuroinflammation in a rat model of Alzheimer's disease

Alzheimer's disease (AD) is the seventh most common cause of mortality and one of the major causes of disability and vulnerability in the elderly. AD is characterized by gradual cognitive deterioration, the buildup of misfolded amyloid beta (Aβ) peptide, and the generation of neurofibrillary tangles. Despite enormous scientific progress, there is no effective cure for AD. Thus, exploring new treatment options to stop AD or at least slow down its progress is important. In this study, we investigated the potential therapeutic effects of MCC950 on NLRP3-mediated inflammasome-driven inflammation and autophagy in AD. Rats treated with streptozotocin (STZ) exhibited simultaneous activation of the NLRP3 inflammasome and autophagy, as confirmed by Western blot, immunofluorescence, and co-immunoprecipitation analyses. MCC950, a specific NLRP3 inhibitor, was intraperitoneally administered (50 mg/kg body weight) to rats with AD-like symptoms induced by intracerebroventricular STZ injections (3 mg/kg body weight). MCC950 effectively suppressed STZ-induced cognitive impairment and anxiety by inhibiting NLRP3-dependent neuroinflammation. Moreover, our findings indicate that MCC950 exerts neuroprotective effects by attenuating autophagy in neuronal cells. The inhibiting effects of MCC950 on inflammasome activation and autophagy were reproduced in vitro, provding further mechansistic insights into MCC950 therapeutic action. Our findings suggest that MCC950 impedes the progression of AD and may also improve cognitive function through the mitigation of autophagy and NLRP3 inflammasome inhibition. [Abstract copyright: Copyright © 2023 Elsevier Inc. All rights reserved.

Prevention of the foreign body response to implantable medical devices by inflammasome inhibition.

SignificanceImplantable electronic medical devices (IEMDs) are used for some clinical applications, representing an exciting prospect for the transformative treatment of intractable conditions such Parkinson's disease, deafness, and paralysis. The use of IEMDs is limited at the moment because, over time, a foreign body reaction (FBR) develops at the device-neural interface such that ultimately the IEMD fails and needs to be removed. Here, we show that macrophage nucleotide-binding oligomerization domain-like receptor family pyrin domain containing 3 (NLRP3) inflammasome activity drives the FBR in a nerve injury model yet integration of an NLRP3 inhibitor into the device prevents FBR while allowing full healing of damaged neural tissue to occur.Part of the RNA-Seq work was performed with the Genomics and Transcriptomics Core, which is funded by the UK Medical Research Council (MRC) Metabolic Disease Unit (MRC_MC_UU_00014/5) and a Wellcome Trust Major Award (208363/Z/17/Z), and guidance from Marcella Ma, whom the authors wish to thank. CEB was supported by a Wellcome Trust Investigator award (108045/Z/15/Z). This work was also supported by the UK Wellcome Trust (Translational Medicine and Therapeutics PhD Programme Fellowship 109511/Z/15/Z to DGB), the UK Health Education England and the National Institute for Health Research (HEE/ NIHR ICA Program Clinical Lectureship CL-2019-14-004 to DGB), the UK Medical Research Council (MRC) and the Sackler Foundation (doctoral training grant RG70550 to ACL), the Engineering and Physical Sciences Research Council (EPSRC) Cambridge NanoDTC (EP/L015978/1), the Centre for Trophoblast Research (MP and RSH), the Whitaker International Scholars Program (ALR), the European Commission’s Horizon 2020 (Marie Sklodowska-Curie Fellowship 797506 to ALR), the Bertarelli Foundation (SPL), the European Research Council (Consolidator Award 772426 to KF), the UK Biotechnology and Biological Sciences Research Council (Research Grant BB/N006402/1 to KF), and the Alexander von Humboldt Foundation (Humboldt Professorship to KF)

Specific inhibition of NLRP3 in chikungunya disease reveals a role for inflammasomes in alphavirus-induced inflammation

Mosquito-borne viruses can cause severe inflammatory diseases and there are limited therapeutic solutions targeted specifically at virus-induced inflammation. Chikungunya virus (CHIKV), a re-emerging alphavirus responsible for several outbreaks worldwide in the past decade, causes debilitating joint inflammation and severe pain. Here, we show that CHIKV infection activates the NLRP3 inflammasome in humans and mice. Peripheral blood mononuclear cells isolated from CHIKV-infected patients showed elevated NLRP3, caspase-1 and interleukin-18 messenger RNA expression and, using a mouse model of CHIKV infection, we found that high NLRP3 expression was associated with peak inflammatory symptoms. Inhibition of NLRP3 activation using the small-molecule inhibitor MCC950 resulted in reduced CHIKV-induced inflammation and abrogated osteoclastogenic bone loss and myositis, but did not affect in vivo viral replication. Mice treated with MCC950 displayed lower expression levels of the cytokines interleukin-6, chemokine ligand 2 and tumour necrosis factor in joint tissue. Interestingly, MCC950 treatment abrogated disease signs in mice infected with a related arthritogenic alphavirus, Ross River virus, but not in mice infected with West Nile virus—a flavivirus. Here, using mouse models of alphavirus-induced musculoskeletal disease, we demonstrate that NLRP3 inhibition in vivo can reduce inflammatory pathology and that further development of therapeutic solutions targeting inflammasome function could help treat arboviral disease

Interleukin-10 regulates the inflammasome-driven augmentation of inflammatory arthritis and joint destruction

Introduction: Activation of the inflammasome has been implicated in the pathology of various autoinflammatory and autoimmune diseases. While the NLRP3 inflammasome has been linked to arthritis progression, little is known about its synovial regulation or contribution to joint histopathology. Regulators of inflammation activation, such as interleukin (IL)-10, may have the potential to limit the inflammasome-driven arthritic disease course and associated structural damage. Hence, we used IL-10-deficient (IL-10KO) mice to assess NLRP3 inflammasome-driven arthritic pathology.Methods: Antigen-induced arthritis (AIA) was established in IL-10KO mice and wild-type controls. Using histological and radiographic approaches together with quantitative real-time PCR of synovial mRNA studies, we explored the regulation of inflammasome components. These were combined with selective blocking agents and ex vivo investigative studies in osteoclast differentiation assays.Results: In AIA, IL-10KO mice display severe disease with increased histological and radiographic joint scores. Here, focal bone erosions were associated with increased tartrate-resistant acid phosphatase (TRAP)-positive cells and a localized expression of IL-1β. When compared to controls, IL-10KO synovium showed increased expression of Il1b, Il33 and NLRP3 inflammasome components. Synovial Nlrp3 and Casp1 expression further correlated with Acp5 (encoding TRAP), while neutralization of IL-10 receptor signaling in control mice caused increased expression of Nlrp3 and Casp1. In ex vivo osteoclast differentiation assays, addition of exogenous IL-10 or selective blockade of the NLRP3 inflammasome inhibited osteoclastogenesis.Conclusions: These data provide a link between IL-10, synovial regulation of the NLRP3 inflammasome and the degree of bone erosions observed in inflammatory arthritis