Biology subjects

Damoiseaux, R.

Publications and source records attributed to Damoiseaux, R..

31 records · Page 2Linked to original sources

bioRxiv2023

FLECS Technology for High-Throughput Screening of Hypercontractile Cellular Phenotypes in Fibrosis: A Function-First Approach to Anti-Fibrotic Drug Discovery

The pivotal role of myofibroblast contractility in the pathophysiology of fibrosis is widely recognized, yet HTS approaches are not available to quantify this critically important function in drug discovery. We develop, validate, and scale-up a HTS platform that quantifies contractile function of primary human lung myofibroblasts upon treatment with pro-fibrotic TGF-{beta}1. With the fully automated assay we screened a library of 40,000 novel small molecules in under 80 h of total assay run-time. We identified 42 hit compounds that inhibited the TGF-{beta}1-induced contractile phenotype of myofibroblasts, and enriched for 19 that specifically target myofibroblasts but not phenotypically related smooth muscle cells. Selected hits were validated in an ex vivo lung tissue models for their inhibitory effects on fibrotic gene upregulation by TGF-{beta}1. Our results demonstrate that integrating a functional contraction test into the drug screening process is key to identify compounds with targeted and diverse activity as potential anti-fibrotic agents.

bioengineering↗

bioRxiv2023

NSC95397 is a Novel HIV Latency Reversing Agent

The latent viral reservoir represents one of the major barriers of curing HIV-1. Focus on the "kick and kill" approach, in which virus expression is reactivated then cells producing virus are selectively depleted, has led to the discovery of many latency reversing agents (LRAs) that have furthered our understanding of the mechanisms driving HIV-1 latency and latency reversal. Thus far, individual compounds have yet to be robust enough to work as a therapy, highlighting the importance of identifying new compounds that target novel pathways and synergize with known LRAs. In this study, we identified a promising LRA, NSC95397, from a screen of [~]4250 compounds. We validated that NSC95397 reactivates latent viral transcription and protein expression from cells with unique integration events and across different latency models. Co-treating cells with NSC95397 and known LRAs demonstrated that NSC95397 synergizes with different drugs under both standard normoxic and physiological hypoxic conditions. NSC95397 does not globally increase open chromatin, and bulk RNA sequencing revealed NSC95397 does not greatly increase cellular transcription. Instead, NSC95397 downregulates pathways key to metabolism, cell growth, and DNA repair - highlighting the potential of these pathways in regulating HIV-1 latency. Overall, we identified NSC95397 as a novel LRA that does not largely alter global transcription, that shows potential for synergy with known LRAs, and that may act through novel pathways not previously recognized for their ability to modulate HIV-1 latency. ImportanceOne of the largest barriers to curing HIV-1 is the latent viral reservoir - this is when the virus incorporates itself into long-lived cells in the body, ready to reactivate and re-seed infection. Destroying dormant HIV-1 is one potential pathway to a cure, yet no therapeutics have been discovered to work well in patients. In our study, we identified a compound, NSC95397, that can awaken dormant HIV-1 on its own through novel mechanisms not previously linked to HIV-1 latency. Moreover, NSC95397 improves the abilities of previously identified compounds to reactivate latent HIV-1. Thus, our study has identified a compound that can help towards the better understanding of an HIV-1 cure.

microbiology↗

bioRxiv2022

Identification of a Papain-Like Protease Inhibitor with Potential for Repurposing in Combination with an Mpro Protease Inhibitor for Treatment of SARS-CoV-2

SARS-CoV-2 requires two cysteine proteases for viral polypeptide processing to allow maturation and replication: the 3C-like protease also known as the Main protease (Mpro) and the papain-like protease (PLpro). In addition to its critical role in viral replication, PLpro removes post-translational modifications like ubiquitin and interferon-stimulated gene product 15 (ISG15) from host proteins through its deubiquitinase domain, leading to host immunosuppression and increased ability of the virus to evade the host antiviral immune response. Through screening of a custom clinical compound library, we identified eltrombopag (DDL-701), a thrombopoietin receptor agonist, as having PLpro inhibitory activity that is sustained in the presence of the Mpro inhibitor nirmatrelvir. DDL-701 also suppressed both the deubiquitinase and ISG15 cleavage activities of PLpro. In addition, DDL-701 partially restored interferon-{beta} induction - an element of the host immune response - in an in vitro model system. Further, modeling and docking studies suggest DDL-701 interacts with the active site region of the PLpro enzyme and pilot pharmacokinetic studies indicate it is brain permeable. DDL-701 is already approved for treatment of thrombocytopenia and has previously been shown to achieve human plasma levels after oral dosing that is above the IC50 needed for it to exert its PLpro inhibitory activity in vivo. In addition, it has also been reported to have antiviral efficacy against SARS-CoV-2. DDL-701 thus represents a drug that can immediately be repurposed and undergo clinical evaluation as a PLpro inhibitor that may be most effectively used in a protease inhibitor cocktail with an Mpro inhibitor such as nirmatrelvir (Paxlovid) for the treatment of COVID-19.

microbiology↗

bioRxiv2022

Assessing Functional Androgen Receptor Pathway Activity in Response to Radiotherapy Using hK2-targeted PET Imaging

External beam radiotherapy (EBRT) remains a common treatment for all stages of PCa, but DNA damage induced by EBRT upregulates androgen receptor (AR) pathway activity to promote therapeutic resistance. [89Zr]11B6-PET is a novel modality targeting prostate-specific protein human kallikrein 2 (hK2), which is a surrogate biomarker for AR activity. Here, we studied if [89Zr]11B6-PET can accurately assess EBRT-induced AR activity. PCa mouse models received EBRT (2-50 Gy) and treatment response was monitored by [89Zr]11B6-PET/CT. Radiotracer uptake and expression of AR and AR target genes was quantified in resected tissue. EBRT increased AR pathway activity in LNCaP-AR tumors. EBRT increased prostate-specific [89Zr]11B6 uptake and hK2 levels in PCa-bearing mice (Hi-Myc x Pb_KLK2) with no significant changes in uptake in healthy (Pb_KLK2) mice. Thus, [89Zr]11B6-PET specifically detects activation of AR pathway activity after EBRT in PCa. Further clinical evaluation of hK2-PET for monitoring EBRT is warranted.

cancer biology↗

bioRxiv2021

Inhibition of amyloid formation of the Nucleoprotein of SARS-CoV-2

The SARS-CoV-2 Nucleoprotein (NCAP) functions in RNA packaging during viral replication and assembly. Computational analysis of its amino acid sequence reveals a central low-complexity domain (LCD) having sequence features akin to LCDs in other proteins known to function in liquid-liquid phase separation. Here we show that in the presence of viral RNA, NCAP, and also its LCD segment alone, form amyloid-like fibrils when undergoing liquid-liquid phase separation. Within the LCD we identified three 6-residue segments that drive amyloid fibril formation. We determined atomic structures for fibrils formed by each of the three identified segments. These structures informed our design of peptide inhibitors of NCAP fibril formation and liquid-liquid phase separation, suggesting a therapeutic route for Covid-19. One Sentence SummaryAtomic structures of amyloid-driving peptide segments from SARS-CoV-2 Nucleoprotein inform the development of Covid-19 therapeutics.

biochemistry↗

bioRxiv2020

PSA-targeted Alpha-, Beta- and Positron Emitting Immuno-Theranostics in Murine Prostate Cancer Models and Non-Human Primates

PurposeMost prostate cancer (PCa) patients treated with androgen receptor (AR)-signaling inhibitors develop therapeutic resistance due to restoration of AR-functionality. Thus, there is a critical need for novel treatment approaches. Here we investigate the theranostic potential of hu5A10, a humanized monoclonal antibody specifically targeting free prostate-specific antigen (KLK3). Experimental DesignLNCaP-AR xenografts (NSG mice) and KLK3_Hi-Myc transgenic mice were imaged with 89Zr- or treated with 90Y- or 225Ac-labeled hu5A10; biodistribution and subcellular localization were analyzed by gamma-counting, positron emission tomography (PET), autoradiography and microscopy. Therapeutic efficacy of [225Ac]hu5A10 and [90Y]hu5A10 in LNCaP-AR tumors was assessed by tumor volume measurements, time to nadir (TTN), time to progression (TTP), and survival. Pharmacokinetics of [89Zr]hu5A10 in non-human primates (NHP) were determined using PET. ResultsBiodistribution of radiolabeled hu5A10-constructs was comparable in different mouse models. Specific tumor uptake increased over time and correlated with PSA expression. Treatment with [90Y]/[225Ac]hu5A10 effectively reduced tumor burden and prolonged survival (p[≤]0.0054). Effects of [90Y]hu5A10 were more immediate than [225Ac]hu5A10 (TTN, p<0.0001) but less sustained (TTP, p<0.0001). Complete responses were observed in 7/18 [225Ac]hu5A10 and 1/9 mice [90Y]hu5A10. Pharmacokinetics of [89Zr]hu5A10 were consistent between NHPs and comparable to those in mice. [89Zr]hu5A10-PET visualized the NHP-prostate over the 2-week observation period. ConclusionsWe present a complete preclinical evaluation of radiolabeled hu5A10 in mouse PCa models and NHPs, and establish hu5A10 as a new theranostic agent that allows highly specific and effective downstream targeting of AR in PSA-expressing tissue. Our data support the clinical translation of radiolabeled hu5A10 for treating PCa.

cancer biology↗

bioRxiv2020

DUSP7 Regulates the Activity of ERK2 to PromoteProper Chromosome Alignment During Cell Division

Human cell division is a highly regulated process that relies on the accurate capture and movement of chromosomes to the metaphase plate. Errors in the fidelity of chromosome congression and alignment can lead to improper chromosome segregation, which is correlated with aneuploidy and tumorigenesis. Here we show that the dual specificity phosphatase DUSP7 is important for regulating chromosome alignment. DUSP7 bound to ERK2 and regulated the abundance of active phospho-ERK2 through its phosphatase activity. Overexpression of DUSP7, but not catalytic dead mutants, led to a marked decrease in phopho-ERK2 and mitotic chromosome misalignment, while knockdown of DUSP7 also led to defective chromosome congression that resulted in a prolonged mitosis. Consistently, chemical inhibition of the MEK kinase that phosphorylates ERK2 or ERK2 itself led to chromosome alignment defects. Our results support a model where MEK phosphorylation and DUSP7 dephosphorylation regulate the levels of active phospho-ERK2 to promote proper cell division.

cell biology↗

bioRxiv2020

Massively parallel encapsulation of single cells with structured microparticles and secretion-based flow sorting

Techniques to analyze and sort single cells based on functional outputs, such as secreted products, have the potential to transform our understanding of cellular biology, as well as accelerate the development of next generation cell and antibody therapies. However, secreted molecules rapidly diffuse away from cells, and analysis of these products requires specialized equipment and expertise to compartmentalize individual cells and capture their secretions. Herein we demonstrate the use of suspendable microcontainers to sort single viable cells based on their secreted products at high-throughput using only commonly accessible laboratory infrastructure. Our microparticles act as solid supports which facilitate cell attachment, partition uniform aqueous compartments, and capture secreted proteins. Using this platform, we demonstrate high-throughput screening of stably- and transiently-transfected producer cells based on relative IgG production as well as screening of B lymphocytes and hybridomas based on antigen-specific antibody production using commercially available flow sorters. Leveraging the high-speed sorting capabilities of standard sorters, we sorted >1,000,000 events in less than an hour. The reported microparticles can be easily stored, and distributed as a consumable reagent amongst researchers, democratizing access to high-throughput functional cell screening.

bioengineering↗

bioRxiv2019

The Dopamine Receptor Antagonist TFP Prevents Phenotype Conversion and Improves Survival in Mouse Models of Glioblastoma

Glioblastoma (GBM) is the deadliest adult brain cancer and all patients ultimately succumb to the disease. Radiation therapy (RT) provides survival benefit of 6 months over surgery alone but these results have not improved in decades. We report that radiation induces a glioma-initiating cell phenotype and we have identified trifluoperazine (TFP) as a compound that interferes with this phenotype conversion. TFP caused loss of radiation-induced Nanog mRNA expression, activation of GSK3 with consecutive post-translational reduction in p-Akt, Sox2 and {beta}-catenin protein levels. TFP did not alter the intrinsic radiation sensitivity of glioma-initiating cells (GICs). Continuous treatment with TFP and a single dose of radiation reduced the number of GICs in vivo and prolonged survival in syngeneic and patient-derived orthotopic xenograft (PDOX) mouse models of GBM. Our findings suggest that combination of a dopamine receptor antagonist with radiation enhances the efficacy of RT in GBM by preventing radiation-induced phenotype conversion of radiosensitive non-GICs into treatment resistant, induced GICs. SignificanceGBM is the most common and most deadly adult brain cancer. The current standard-of-care is surgery followed by RT and temozolomide, which results in a median survival time of only 15 months. The efficacy of chemotherapies and targeted therapies in GBM is very limited because most of these drugs do not pass the blood-brain-barrier. Ultimately, all patients succumb to the disease. Our study describes radiation-induced cellular plasticity as a novel resistance mechanism in GBM. We identified a dopamine receptor antagonist as a readily available, FDA-approved drug known to penetrate the blood-brain-barrier which prevents phenotype conversion of glioma cells into glioma-initiating cells and prologs survival in mouse models of GBM, thus suggesting that it will improve the efficacy of RT without increasing toxicity.

neuroscience↗

bioRxiv2019

Genetic signature of prostate cancer resistant to optimized hK2 targeted alpha-particle therapy

Hu11B6 is a monoclonal antibody that internalizes in cells expressing androgen receptor (AR)-regulated prostate specific enzyme human kallikrein 2 (hK2; KLK2). In multiple rodent models, Actinium-225 labeled hu11B6-IgG1 ([225Ac]hu11B6-IgG1) has shown promising treatment efficacy. In the current study we investigated options to enhance and optimize [225Ac]hu11B6 treatment. Firstly, we evaluated the possibility of exploiting IgG3, the immunoglobulin G (IgG) subclass with superior activation of complement and ability to mediate FC-gamma-receptor binding, for immunotherapeutically enhanced hK2 targeted alpha-radioimmunotherapy. Secondly, we compared the therapeutic efficacy of a single high activity vs. fractionated activity. Finally, we used RNA sequencing to analyze the genomic signatures of prostate cancer that progressed after targeted alpha therapy. [225Ac]hu11B6-IgG3 was a functionally enhanced alternative to [225Ac]hu11B6-IgG1 but offered no improvement of therapeutic efficacy. Progression free survival was slightly increased with a single high activity compared to fractionated activity. Tumor free animals succumbing after treatment revealed no evidence of treatment associated toxicity. In addition to upregulation of canonical aggressive prostate cancer genes, such as MMP7, ETV1, NTS and SCHLAP1, we also noted a significant decrease in both KLK3 (PSA) and FOLH1 (PSMA) but not in AR and KLK2, demonstrating efficacy of sequential [225Ac]hu11B6 in a mouse model.

cancer biology↗

bioRxiv2018

Transitions in interaction landscapes of multidrug combinations

Drug combinations are a promising strategy to increase killing efficiency and to decrease the likelihood of evolving resistance. A major challenge is to gain a detailed understanding of how drugs interact in a dose-specific manner, especially for interactions involving more than two drugs. Here we introduce a direct and intuitive visual representation that we term \"interaction landscapes\". We use these landscapes to clearly show that the interaction type of two drugs typically transitions smoothly from antagonism to no interaction to synergy as drug doses increase. This finding contradicts prevailing assumptions that interaction type is always the same. Our results, from 56 interaction landscapes, are derived from all possible three-drug combinations among 8 antibiotics, each varied across a range of 7 concentrations and applied to a pathogenic Escherichia coli strain. Such comprehensive data and analysis are only recently possible through implementation of an automated high-throughput drug-delivery system and an explicit mathematical framework that disentangles pairwise versus three-way as well as net (any effect) versus emergent (requiring all three drugs) interactions. Altogether, these landscapes partly capture and encapsulate selective pressures that correspond to different dose regions and could help optimize treatment strategies. Consequently, interaction landscapes have profound consequences for choosing effective drug-dose combinations because there are regions where small changes in dose can cause large changes in pathogen killing efficiency and selective pressure.

evolutionary biology↗

bioRxiv2017

Prevalence and patterns of higher-order interactions

Interactions and emergent processes are essential for research on complex systems involving many components. Most studies focus solely on pairwise interactions and ignore higher-order interactions among three or more components. To gain deeper insights into higher-order interactions and complex environments, we study antibiotic combinations applied to pathogenic Escherichia coli and obtain unprecedented amounts of detailed data (251 two-drug combinations, 1512 three-drug combinations, 5670 four-drug combinations, and 13608 five-drug combinations). Directly opposite to previous assumptions and reports, we find higher-order interactions increase in frequency with the number of drugs in the bacterias environment. Furthermore, we observe a shift towards net synergy (effect greater than expected based on independent individual effects) and towards emergent antagonism (effect less than expected based on lower-order interaction effects). These findings have implications for the potential efficacy of drug combinations and are crucial for better navigating problems associated with the combinatorial complexity of multi-component systems.

systems biology↗

bioRxiv2017

Miniring approach for high-throughput drug screenings in 3D tumor models

There is increasing interest in developing 3D tumor organoid models for drug development and personalized medicine applications. While tumor organoids are in principle amenable to high-throughput drug screenings, progress has been hampered by technical constraints and extensive manipulations required by current methodologies. Here, we introduce a miniaturized, fully automatable, flexible high-throughput method using a simplified geometry to rapidly establish 3D organoids from cell lines and primary tissue and robustly assay drug responses. As proof of principle, we use our miniring approach to establish organoids of high-grade serous tumors and one carcinosarcoma of the ovaries and screen hundreds of protein kinase compounds currently FDA-approved or in clinical development. In all cases we could identify drugs causing significant reduction in cell viability, number and size of organoids within a week from surgery, a timeline compatible with therapeutic decision making.

cancer biology↗