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Biology subjects

Batut, A.

Publications and source records attributed to Batut, A..

6 recordsLinked to original sources

The NaaS Methodology applied to modeling chemotherapy-induced peripheral neuropathy with human hiPSC neurons

The Neuron-as-a-Sensor (NaaS) methodology is a human-relevant platform designed to detect compound-induced effects by capturing functional changes in neuronal activity. This is achieved by integrating hiPSC-derived neuronal cultures, compartmentalized MEA microfluidic devices, a detailed electrophysiology paradigm and a standardized analysis pipeline. Applied to chemotherapy-induced peripheral neuropathy (CIPN), NaaS leverages electrophysiological profiling to capture alterations in neuronal excitability beyond cytotoxicity. Using paclitaxel and oxaliplatin as reference compounds, we demonstrated drug-specific, time-dependent changes in spontaneous and thermally evoked activity that align with their distinct clinical neuropathic phenotypes. Dimensionality reduction of electrophysiological metrics enabled construction of a functional discrimination map, allowing robust separation of compound signatures from vehicle controls. These findings highlight the ability of NaaS to model clinically relevant neurotoxic effects in a scalable manner, supporting its application in both adverse effect prediction and therapeutic screening.

bioengineering↗

Neurons as biosensors for discriminating neurological disorders in a brain-on-chip platform: Application to Alzheimer s Disease using patient CSF

Alzheimers disease (AD) is characterized by the accumulation of aggregated amyloid beta peptide (A{beta}) leading to progressive neuronal loss and dysfunction. Current ADs diagnosis involves biomarkers assays in cerebrospinal fluid (CSF) as A{beta} to validate the diagnosis. However, these methods are time-consuming, expensive, and can result in inaccurate diagnoses by not accounting for differential diagnose. To overcome these challenges, researchers are exploring new technologies for detecting AD biomarkers in biological fluids, though progress is hindered by an incomplete understanding of AD mechanisms and CSF composition. In this study, we used a standardized microfluidic platform to investigate the effects of synthetic A{beta} peptides and cerebrospinal fluid (CSF) from AD and healthy patients on neuronal functional activity. First, human neurons derived from induced pluripotent stem cells (iPSCs) were characterized. Then, to modulate the functional activity of neurons, tetrodotoxin (TTX), a specific sodium channel blocker, was used as a control for inhibiting neuronal activity. Subsequently, glutamatergic neurons were chronically exposed to A{beta}O and patients CSF. MEA recordings were performed before and after the treatments to assess changes in network activity. Our results demonstrated that extracting key electrophysiological metrics allows for discrimination between healthy and AD CSF samples. This system could offer the potential for differential diagnosis and development of personalized therapeutic strategies.

neuroscience↗

Deposition chamber technology as building blocks for a standardized brain-on-chip framework

In vitro modeling of human brain connectomes is key to explore the structure-function relationship of the central nervous system. The comprehension of this intricate relationship will serve to better study the pathological mechanisms of neurodegeneration, and hence to perform improved drug screenings for complex neurological disorders, such as Alzheimers and Parkinsons diseases. However, currently used in vitro modeling technologies lack potential to mimic physiologically relevant neural structures, because they are unable to represent the concurrent interconnectivity between myriad subtypes of neurons across multiple brain regions. Here, we present an innovative microfluidic design that allows the controlled and uniform deposition of various specialized neuronal populations within unique plating chambers of variable size and shape. By applying our design, we offer novel neuro-engineered microfluidic platforms, so called neurofluidic devices, which can be strategically used as organ-on-a-chip platforms for neuroscience research. Through the fine tuning of the hydrodynamic resistance and the cell deposition rate, the number of neurons seeded in each plating chamber can be tailored from a thousand up to a million, creating multi-nodal circuits that represent connectomes existing within the intact brain. These advances provide essential enhancements to in vitro platforms in the quest accurately model the brain for the investigation of human neurodegenerative diseases.

bioengineering↗

Neurite growth kinetics regulation through hydrostatic pressure in a novel triangle-shaped neurofluidic system

Microfluidic neuro-engineering design rules have been widely explored to create in vitro neural networks with the objective to replicate physiologically relevant structures of the brain. Several neurofluidic strategies have been reported to study the connectivity of neurons, either within a population or between two separated populations, through the control of the directionality of their neuronal projections. Yet, the in vitro regulation of the growth kinetics of those projections remains challenging. Here, we describe a new neurofluidic chip with a triangular design that allows the accurate monitoring of neurite growth kinetics in a neuronal culture. This device permits to measure the maximum achievable length of projecting neurites over time and to report variations in neurite length under several conditions. Our results show that, by applying positive or negative hydrostatic pressure to primary rat hippocampal neurons, neurite growth kinetics can be tuned. This work presents a pioneering approach for the precise characterization of neurite length dynamics within an in vitro minimalistic environment.

neuroscience↗

Nuclear HMGB1 protects from non-alcoholic fatty liver diseases through negative regulation of liver X receptor

Dysregulations of lipid metabolism in the liver may trigger steatosis progression leading to potentially severe clinical consequences such as non-alcoholic fatty liver diseases (NAFLD). Molecular mechanisms underlying liver lipogenesis are very complex and fine-tuned by chromatin dynamics and the activity of multiple key transcription factors. Here, we demonstrate that the nuclear factor HMGB1 acts as a strong repressor of liver lipogenesis during metabolic stress in NAFLD. Mice with liver-specific Hmgb1-deficiency display exacerbated liver steatosis and hepatic insulin resistance when subjected to a high-fat diet or after fasting/refeeding. Global transcriptome and functional analysis revealed that the deletion of Hmgb1 gene enhances LXR activity resulting in increased lipogenesis. HMGB1 repression is not mediated through nucleosome landscape re-organization but rather via a preferential DNA occupation in region carrying genes regulated by LXR. Together these findings suggest that hepatocellular HMGB1 protects from liver steatosis development. HMGB1 may constitute a new attractive option to therapeutically target LXR axis during NAFLD.

pathology↗

Hepatocyte-specific deletion of Pparα promotes NASH in the context of obesity

ObjectivesPeroxisome proliferator activated receptor (PPAR) acts as a fatty acid sensor to orchestrate the transcription of genes coding for rate-limiting enzymes required for lipid oxidation in hepatocytes. Mice only lacking Ppar in hepatocytes spontaneously develop steatosis without obesity in aging. Altough steatosis is a benign condition it can develop into non alcoholic steatohepatitis (NASH), which may progress to irreversible damage, such as fibrosis and hepatocarcinoma. While NASH appears as a major public health concern worldwide, it remains an unmet medical need. Several drugs are being tested in clinical trials, including pharmacological agonists for the different PPAR isotypes. In current study, we investigated the role of hepatocyte PPAR in a preclinical model of steatosis.\n\nMethods/ResultsWe have investigated the role of hepatocyte PPAR in a preclinical model of steatosis using High Fat Diet (HFD) feeding as a model of obesity in C57BL/6J male Wild-Type mice (WT), in whole-body (Ppar-/-) mice and in mice lacking Ppar in hepatocyte (Pparhep-/-). We provide evidence that Ppar deletion in hepatocytes promotes NASH in mice fed an HFD. This enhanced NASH susceptibility occurs without development of glucose intolerance. Moreover, our data reveal that non-hepatocytic PPAR activity predominantly contributes to the metabolic response to HFD.\n\nConclusionTaken together, our data support hepatocyte PPAR as being essential to the prevention of steatosis progression to NASH and that extra-hepatocyte PPAR activity contributes to whole-body lipid homeostasis.\n\nHighlightsO_LIPpar deletion in hepatocytes promotes steatosis and inflammation in HFD-induced obesity\nC_LIO_LIHepatocyte-specific deletion of Ppar dissociates NAFLD from glucose intolerance in HFD-induced obesity obesity\nC_LIO_LIExtrahepatic PPAR activity contributes to the metabolic response to HFD-induced obesity\nC_LI

pathology↗