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Biology subjects

Bailly, S.

Publications and source records attributed to Bailly, S..

4 recordsLinked to original sources

Dual targeting of GPX4 and TXNRD1 triggers eradication of AML cells through induction of apoptosis and ferroptosis

MyeloDysplastic Syndromes (MDS) are a group of heterogeneous hematological disorders characterized by bone marrow failure and abnormal hematopoietic cell expansion, often progressing to acute myeloid leukemia (AML). Current treatments for AML and high-risk MDS have limited efficacy, requiring the exploration of new therapeutic approaches. Recent research highlighted the potential of inducing cell death through ferroptosis, either independently or alongside traditional chemotherapy, as promising approaches for treating MDS/AML cells. We described here two novel compounds, HA344 and #231, capable of targeting both ferroptosis and apoptosis, leading to the effective eradication of cell lines and primary blasts from MDS/AML patients, while sparing normal hematopoietic cells. RNASeq analysis identified oxidation reduction and apoptotic processes as highly significant induced pathways in two different AML cell lines. Using click-chemistry approaches coupled to mass spectrometry, we identified glutathione peroxidase 4 (GPX4) and thioredoxin reductase 1 (TXNRD1) as the main targets of HA344 and #231 in a large panel of AML cells. Accordingly, both compounds inhibited GPX4 and TXNRD1 activity in the micromolar range and triggered GPX4 degradation. Moreover, using recombinant GPX4 carrying or not a selenium (GPX4-Se and GPX4-S), we confirmed by mass spectrometry that HA344 and #231 bind more efficiently GPX4-Se than GPX4-S. In conclusion, these compounds might represent a new pharmacological approach in the treatment of MDS and AML, offering a potential avenue for future therapies.

biochemistry↗

Two new qPCR assays for detecting and quantifying the Aspergillus flavus and Aspergillus parasiticus clades in maize kernels

The fungi of Aspergillus section Flavi mostly produce carcinogenic mycotoxins -- aflatoxins (AFs) -- of two types: types B and G (AFBs and AFGs). AF are highly hazardous for human and animal health. Their levels in food and feed are therefore highly regulated, with a low acceptable limit for AF content. In France, global warming has led to the detection of AFs in maize harvests since 2015. Mycoflora analyses have identified two species, A. flavus (producing AFBs) and A. parasiticus (producing both AFBs and AFGs), as responsible for this AF contamination. However, mycoflora analysis is a time-consuming method that cannot readily be applied to large numbers of samples. We propose here an alternative clade-specific functional TaqMan(R) qPCR method based on the calmodulin gene for distinguishing between the A. flavus clade (AfC) and the A. parasiticus clade (ApC). We applied this method to 553 maize samples collected in three different harvest years (2018 to 2020). Both clades were detected in about 40% of the samples tested. As expected, we observed significant positive correlations between AFBs and AfC DNA (R{superscript 2} =0.708), and between AFGs and ApC DNA (R{superscript 2} =0.885). This method will be useful for the rapid, simple and cheap characterisation of maize grain contamination with Aspergillus section Flavi. This method will make it possible to study the relationship between agroclimatic conditions, AF content and species prevalence, to facilitate the anticipation of AF risks due to global warming in France.

pathology↗

Non-invasive, Real-time Detection of Vascular Disorders in Mice using Bright SWIR-emitting Gold Nanoclusters and Monte Carlo Image Analysis

We present here a new approach for non-invasive high resolution whole-body vascular imaging in depth by combining water-soluble and bright SWIR-emitting gold nanoclusters revealing an anisotropic surface charge with Monte Carlo image processing of the images. We applied and validated this approach to quantify vessel complexity in transgenic mice presenting vascular disorders.

bioengineering↗

Inflammation is the main risk factor of voriconazole overdose in hematological patients

Aim: Voriconazole (VRC) overdoses are frequent and expose patients at high risk of adverse effects. This case-control study performed in hematological patients who benefited from VRC therapeutic drug monitoring from January 2012 to December 2015 aimed to identify risk factors of VRC overdose.\n\nMethods: Pharmacogenetic, biological, and demographic parameters at the time of VRC trough concentration (Cmin) were retrospectively collected from medical records. Cases (VRC overdose: defined by a VRC Cmin [&ge;] 4 mg/l; n = 31) were compared to controls (no VRC overdose: defined by VRC Cmin < 4 mg/L; n = 31) using non-parametric or Chi-square tests followed by multivariable analysis.\n\nResults: VRC overdoses were significantly associated with high CRP and bilirubin levels, intra-venous administration, and age in univariable analysis. In contrast, the proportion of CYP genotypes (CYP2C19, CYP3A4, or CYP3A5, considered alone or combined in a genetic score1) were not significantly different between patients who experienced a VRC overdose and those who did not. In multivariable analysis, the class of CRP level (defined by median CRP levels of 96 mg/l) was the sole independent risk factor of VRC overdose (p < 0.01). Patients with CRP levels > 96 mg/l had a 27-fold (IC 95%: [6-106]) higher risk of VRC overdose than patients with CRP levels [&le;] 96 mg/l.\n\nConclusion: This study demonstrates that inflammatory status, assessed by CRP levels, is the main risk factor of VRC overdose in French hematological patients, whereas pharmacogenetic determinants do not appear to be involved.

pharmacology and toxicology↗