Biology subjects

Cristobal, S.

Publications and source records attributed to Cristobal, S..

4 recordsLinked to original sources

bioRxiv2023

Predictive toxicology of chemical mixtures using proteome-wide thermal profiling and protein target properties

Our capability to predict the impact of exposure to chemical mixtures on environmental and human health is limited in comparison to the advances on the chemical characterization of the exposome. Current approaches, such as new approach methodologies, rely on the chemical mixture characterization and the available toxicological knowledge of individual compounds or similar mixtures. In this study, we show a new methodological approach for assessment of chemical mixtures based on a proteome-wide identification of the protein targets and revealing the relevance of new targets based on their role in the cellular crosstalk. We applied a proteome integral solubility alteration assay to identify 24 protein targets from a chemical mixture of 2,3,7,8- tetrachlorodibenzo-p-dioxin, alpha-endosulfan, and bisphenol A among the HepG2 soluble proteome, and validated the chemical mixture-target interaction orthogonally. To define the range of interactive capability of the new targets, the data from intrinsic properties of the targets were retrieved. Introducing the target properties as criteria for a multi-criteria decision-making analysis called the analytical hierarchy process, the prioritization of targets was based on their involvement in multiple pathways. This methodological approach that we present here opens a more realistic and achievable scenario to address the impact of complex and uncharacterized chemical mixtures in biological systems. SYNOPSISMethods for unbiased identification of protein targets of chemical mixtures and prediction of their impact in human and environmental health.

pharmacology and toxicology↗

bioRxiv2022

A first-in-class Wiskott-Aldrich syndrome protein (WASp) activator with anti-tumor activity in hematological cancers

Hematological cancers are among the most common cancers in adults and in children. Despite significant improvements in therapies, many patients still succumb to the disease, therefore, novel therapies are needed. The Wiskott-Aldrich syndrome protein (WASp) family proteins regulate actin assembly in conjunction with the Arp2/3 complex, a ubiquitous nucleation factor. WASp is expressed exclusively in hematopoietic cells and exists in two allosteric conformations, auto-inhibited and active conformations. Here, we describe the development of EG-011, a first-in-class small molecule activator of the WASp auto-inhibited form. EG-011 possesses in vitro and in vivo anti-tumor activity as single agent in lymphoma, leukemia and multiple myeloma, including models of secondary resistance to PI3K, BTK and proteasome inhibitors. The in vitro activity was confirmed in a lymphoma xenograft. Actin polymerization induced by EG-011 was demonstrated with multiple techniques. Transcriptome analysis highlighted homology with drugs inducing actin polymerization. Key pointsO_LIEG-011 is a novel small molecule with anti-tumor activity in hematological cancers, including resistant lymphoma and multiple myeloma models C_LIO_LIEG-011 is a first-in-class small molecule activator of the auto-inhibited form of the Wiskott-Aldrich syndrome protein (WASp) C_LI

cancer biology↗

bioRxiv2022

Proteome integral solubility alteration assay combined with multi-criteria decision-making analysis for developing adverse outcome pathways

Understanding the biological impact of chemicals is hindered by the high number and diversity of compounds in the market. To simplify the chemical risk assessment, the adverse outcome pathway (AOP) method has arisen as a framework to predict the impact of chemical exposure on human and environmental health. The development of this predictive tool requires knowledge of the molecular interaction between chemicals and protein targets. Those molecular initiating events connect alterations of cellular function with physiological impairment. This strategy aims to focus on the complex biological interaction to predict the impact on health. The high-throughput identification of all chemical targets can be obtained by a proteomics-based thermal shift assay, however, selecting the priority target candidate is a biased process strongly dependent on expert knowledge and literature. Here, we unravel new molecular initiating event from a tested chemical combining the target deconvolution by the proteome integral solubility alteration (PISA) assay, and the target selection by an analytical hierarchy process (AHP) approach. In the proof-of-concept study, we identified by PISA assay 8 protein targets for 2,3,7,8 tetrachlorodibenzo-p-dioxin (TCDD) from the soluble proteome from hepatic cells containing 2824 proteins. The definition of the AHP approach facilitates the selection of heat shock protein beta-1 (Hspb1) as the most suitable protein for developing AOPs. Our results demonstrated that the process of target identification is independent from a chemical characterization, and that the process of data curation and target selection is less sensitive to lack of toxicological information. We anticipate that this innovative integration of methods could decipher the chemical-protein interactions from new chemicals including the new alternative chemicals designed for chemical replacement and that would discover new molecular initiating events to support more sustainable methodologies to gain time and resources in chemicals assessment. SYNOPSISOur combined methodologies can determine the most suitable target to develop adverse outcome pathways from the proteome-wide protein target identification.

pharmacology and toxicology↗

bioRxiv2022

Nonionic surfactants can modify the thermal stability of globular and membrane proteins interfering with the thermal proteome profiling principles to identify protein targets

The membrane proteins are essential targets to understand cellular function. The unbiased identification of membrane protein targets is still the bottleneck for a system-level understanding of cellular response to stimuli or perturbations. It has been suggested to enrich the soluble proteome with membrane proteins by introducing nonionic surfactants in the solubilization solution. This strategy was aiming to simultaneous identify the globular and membrane protein targets by thermal proteome profiling principles. However, the thermal shift assay would surpass the cloud point temperature from the nonionic surfactants frequently utilized for membrane protein solubilization. It is expected that around the cloud point temperature, the surfactant micelles would suffer structural modifications altering protein solubility. Here, we show that the presence of nonionic surfactants can alter protein thermal stability from a mixed, globular and membrane, proteome. In the presence of surfactant micelles, the changes in proteins solubility analyzed after the thermal shift assay were affected by the thermal dependent modification of the micellar size, and its interaction with proteins. We demonstrate that the introduction of nonionic surfactants for the solubilization of membrane proteins is not compatible with the principles of target identification by thermal proteome profiling methodologies. Our results lead to explore thermal-independent strategies for membrane protein solubilization to assure confident membrane protein target identification. The proteome-wide thermal shift methods have already shown their capability to elucidate mechanisms of action from pharma, biomedicine, analytical chemistry, or toxicology and finding strategies, free from surfactants, to identify membrane protein targets would be the next challenge.

biophysics↗