Publications by authors named "Thomas Mathivet"

The blood vessel network is heavily impacted by SARS-CoV-2 infection. How SARS-CoV-2 contributes to vascular inflammation and whether epithelio-endothelial cross-talk is involved remain unclear. We investigated in detail the interaction between SARS-CoV-2 and the vasculature using 2D and 3D vesseloid in vitro models.

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Current therapies ultimately fail to eradicate metastatic renal cell carcinoma (RCC). Validated biomarkers and a better understanding of the mechanisms causing therapy resistance are still needed. Here we demonstrate that interleukin-34 (IL34) is associated with poor prognosis, metastasis, and therapy resistance in RCC.

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Aberrant mitochondrial function can lead to severe human diseases, including neurodegenerative diseases and cancer. Here, we describe a cell-based protocol for measuring different mitochondrial respiratory parameters using the high-resolution real-time Resipher system. We optimized this protocol on brain tumor stem cells cultured in three-dimensional spheroids.

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Glioblastoma is one of the most treatment-resistant and lethal cancers, with a subset of self-renewing brain tumour stem cells (BTSCs), driving therapy resistance and relapse. Here, we report that mubritinib effectively impairs BTSC stemness and growth. Mechanistically, bioenergetic assays and rescue experiments showed that mubritinib targets complex I of the electron transport chain, thereby impairing BTSC self-renewal and proliferation.

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Article Synopsis
  • In situ hybridization is a method used to visualize RNA in cells, but analyzing images can be complicated.
  • The presented protocol utilizes open-source software for automating the analysis of multiple RNA probes (up to 14) in fluorescence in situ transcriptomics.
  • Key steps involve segmenting cell nuclei, storing raw data, ensuring quality control, and using a Python app to compile results into a comprehensive spreadsheet that shows cell positivity.
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Unlabelled: Phosphatase of regenerating liver 2 (also known as PTP4A2) has been linked to cancer progression. Still, its exact role in glioblastoma (GBM), the most aggressive type of primary brain tumor, remains elusive. In this study, we report that pharmacologic treatment using JMS-053, a pan-phosphatase of regenerating liver inhibitor, inhibits GBM cell viability and spheroid growth.

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Dysregulated autophagy is associated with cardiovascular and metabolic diseases, where impaired flow-mediated endothelial cell responses promote cardiovascular risk. The mechanism by which the autophagy machinery regulates endothelial functions is complex. We applied multi-omics approaches and in vitro and in vivo functional assays to decipher the diverse roles of autophagy in endothelial cells.

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Glioblastoma (GBM) is the most common and fatal primary tumor of the central nervous system (CNS) and current treatments have limited success. Chemokine signaling regulates both malignant cells and stromal cells of the tumor microenvironment (TME), constituting a potential therapeutic target against brain cancers. Here, we investigated the C-C chemokine receptor type 7 (CCR7) and the chemokine (C-C-motif) ligand 21 (CCL21) for their expression and function in human GBM and then assessed their therapeutic potential in preclinical mouse GBM models.

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Article Synopsis
  • Glioblastoma (GBM) is a very dangerous brain tumor that is hard to treat, even with a lot of research.
  • Scientists are now looking at the area around the tumor (called the tumor microenvironment) to understand how it affects the tumor and how to fight it better.
  • This review brings together ideas from doctors and researchers in France to explain what the tumor microenvironment is like and how it can help create better treatments for GBM.
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During vascular development, endothelial cAMP-dependent protein kinase A (PKA) regulates angiogenesis by controlling the number of tip cells, and PKA inhibition leads to excessive angiogenesis. Whether this role of endothelial PKA is restricted to embryonic and neonatal development or is also required for vascular homeostasis later on is unknown. Here, we show that perinatal (postnatal days P1-P3) of later (P28-P32) inhibition of endothelial PKA using dominant-negative PKA expressed under the control of endothelial-specific Cdh5-CreERT2 recombinase (dnPKA mice) leads to severe subcutaneous edema, hypoalbuminemia, hypoglycemia and premature death.

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Background: Microtubes (MTs), cytoplasmic extensions of glioma cells, are important cell communication structures promoting invasion and treatment resistance through network formation. MTs are abundant in chemoresistant gliomas, in particular, glioblastomas (GBMs), while they are uncommon in chemosensitive IDH-mutant and 1p/19q co-deleted oligodendrogliomas. The aim of this study was to identify potential signaling pathways involved in MT formation.

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Sepsis capillary leak syndrome (SCLS) is an independent prognostic factor for poor sepsis outcome. We previously demonstrated that α1AMP-activated protein kinase (α1AMPK) prevents sepsis-induced vascular hyperpermeability by mechanisms involving VE-cadherin (VE-Cad) stabilization and activation of p38 mitogen activated protein kinase/heat shock protein of 27 kDa (p38MAPK/HSP27) pathway. Canagliflozin, a sodium-glucose co-transporter 2 inhibitor, has recently been proven to activate AMPK in endothelial cells.

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SLIT2 is a secreted polypeptide that guides migration of cells expressing Roundabout 1 and 2 (ROBO1 and ROBO2) receptors. Herein, we investigated SLIT2/ROBO signaling effects in gliomas. In patients with glioblastoma (GBM), SLIT2 expression increased with malignant progression and correlated with poor survival and immunosuppression.

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Rationale: Cerebrovascular function is critical for brain health, and endogenous vascular protective pathways may provide therapeutic targets for neurological disorders. S1P (Sphingosine 1-phosphate) signaling coordinates vascular functions in other organs, and S1P (S1P receptor-1) modulators including fingolimod show promise for the treatment of ischemic and hemorrhagic stroke. However, S1P also coordinates lymphocyte trafficking, and lymphocytes are currently viewed as the principal therapeutic target for S1P modulation in stroke.

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Background: The tumor microenvironment plays a major tumor-supportive role in glioma. In particular, tumor-associated macrophages (TAMs), which can make up to one-third of the tumor mass, actively support tumor growth, invasion, and angiogenesis. Predominantly alternatively activated (M2-polarized) TAMs are found in late-stage glioma in both human and mouse tumors, as well as in relapse samples from patients.

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The role of the innate immune system in ovarian cancer is gaining importance. The relevance of tumor-associated macrophages (TAM) is insufficiently understood. In this pilot project, comprising the immunofluorescent staining of 30 biopsies taken from 24 patients with ovarian cancer, we evaluated the presence of total TAM (cluster of differentiation (CD) 68 expression), M1 (major histocompatibility complex (MHC) II expression), and M2 (anti-mannose receptor C type 1 (MRC1) expression), and the blood vessel diameter.

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Cranial lymphatic vessels (LVs) are involved in the transport of fluids, macromolecules and central nervous system (CNS) immune responses. Little information about spinal LVs is available, because these delicate structures are embedded within vertebral tissues and difficult to visualize using traditional histology. Here we show an extended vertebral column LV network using three-dimensional imaging of decalcified iDISCO-clarified spine segments.

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The presence of tumor infiltrating lymphocytes (TILs) is associated with a longer overall survival in advanced stage epithelial ovarian cancer. Despite the prognostic impact of TILs, response to checkpoint-inhibitors and antigen-specific active immunotherapy is limited in ovarian cancer. The goal of our study was to investigate the interaction between ovarian cancer and the innate and adaptive immune system in the ID8-fLuc syngeneic ovarian cancer mouse model.

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Endothelial cell migration, proliferation and survival are triggered by VEGF-A activation of VEGFR2. However, how these cell behaviors are regulated individually is still unknown. Here we identify Endophilin-A2 (ENDOA2), a BAR-domain protein that orchestrates CLATHRIN-independent internalization, as a critical mediator of endothelial cell migration and sprouting angiogenesis.

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Background: Appropriate information about the benefits and risks of invasive procedures is crucial, but limited data is available in this field. The aim of this study was to evaluate the incremental value of a short video about coronary angiography compared with standard information, in terms of patient understanding, satisfaction and anxiety.

Methods: This prospective multicenter study included patients admitted for scheduled coronary angiography, who were randomized to receive either standard information or video information by watching a three-dimensional educational video.

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Article Synopsis
  • Researchers developed solid lipid nanoparticles (SLN) with modified surface properties to enhance the delivery of inhaled chemotherapy specifically targeting lung tumors.
  • A new folate-grafted copolymer, F-PEG-HTCC, was synthesized and used to prepare SLN that showed near 100% drug encapsulation efficiency and favorable characteristics for targeted delivery.
  • In preclinical studies, these coated SLN significantly improved the effectiveness of paclitaxel against specific cancer cells and demonstrated a prolonged lung exposure time post-delivery, indicating their potential for better treatment outcomes in lung cancer therapy.
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Article Synopsis
  • The discovery of meningeal lymphatic vessels (LVs) has sparked interest in their role in brain health, but their growth and upkeep are not well-understood.
  • LVs begin to develop after birth, starting near skull openings and spreading along blood vessels and nerves to the surrounding protective layers of the brain and spinal cord.
  • Key factors for their development include VEGF-C and VEGFR3, while blocking these pathways can cause regression of these vessels and impair fluid drainage, highlighting their potential for future therapeutic applications.
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Glioma growth and progression are characterized by abundant development of blood vessels that are highly aberrant and poorly functional, with detrimental consequences for drug delivery efficacy. The mechanisms driving this vessel dysmorphia during tumor progression are poorly understood. Using longitudinal intravital imaging in a mouse glioma model, we identify that dynamic sprouting and functional morphogenesis of a highly branched vessel network characterize the initial tumor growth, dramatically changing to vessel expansion, leakage, and loss of branching complexity in the later stages.

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