Biology subjects

Vilain, S.

Publications and source records attributed to Vilain, S..

4 recordsLinked to original sources

bioRxiv2025

Switching ON Hydrogen Sulfide: A Chemogenetic Toolkit for Spatially Resolved H2S Manipulation

Hydrogen sulfide (H2S) is emerging as a multifaceted signalling molecule that shapes energy metabolism, vascular tone, cancer biology and neurodegeneration. Although fluorescent and genetically encoded sensors now allow real-time H2S imaging, tools for selective control of intracellular H2S remain scarce. Here we benchmark two substrate-based chemogenetic enzymes--the yeast D-amino-acid oxidase (mDAAO) and the Salmonella typhimurium D-cysteine desulfhydrase (stDCyD)--for controlled H2S production. Both enzymes catalyse the conversion of D-cysteine to H2S, yet only mDAAO concomitantly generates hydrogen peroxide, introducing an unwanted oxidative signal. In contrast, stDCyD produces exclusively H2S, thereby offering a clean and efficient means to elevate intracellular H2S in vitro. Our data position stDCyD as the superior chemogenetic actuator for dissecting H2S biology without confounding redox artefacts.

biochemistry↗

bioRxiv2024

Development of a Robust Gel-Free 3D Culture System for Generating Spheroids from Axolotl Blastema Cells

Regenerative biology seeks to uncover the principles enabling organisms to restore complex tissues and organs. The axolotl (Ambystoma mexicanum), a salamander with unparalleled limb regenerative capacity, remains a premier model system in this field. However, in vitro studies have been limited by the absence of reliable culture platforms for maintaining blastema cell identity and functionality. Here, we present a robust, gel-free 3D culture protocol that enables the formation of spheroids from axolotl blastema cells under fully defined, serum-free conditions. These spheroids preserve the expression of key regenerative markers such as Prrx1, Msx2, and CTGF for at least 10 days in culture, and exhibit cellular stability supported by antioxidant and amino acid supplementation. Importantly, spheroids cultured for 10 days were capable of initiating extra digit formation when transplanted into limb bud after amputation. With unique advantage of fully defined incubation conditions, this technique adds a powerful in vitro platform to existing experimental models of axolotl limb regeneration.

molecular biology↗

bioRxiv2024

Behavioral screening defines three molecular Parkinsonism subgroups in Drosophila

Parkinsonism is defined by motor dysfunction, but the specific upstream molecular causes of these clinical symptoms can vary widely. We hypothesize that these causes converge onto a limited number of core cellular pathways. To investigate this, we created a new collection of 24 genetically very well-controlled animal models of familial forms of parkinsonism. Using unbiased behavioral screening and machine learning we identified three clusters of mutants that converge on (1) mitochondrial function; (2) retromer/vesicle trafficking; and (3) proteostasis/autophagy. Genes within each cluster have a similar genetic interaction profile and compounds that target specific molecular pathways ameliorate dopaminergic neuron dysfunction in a cluster-specific manner. This suggests that familial parkinsonism can be stratified into three broad functional groups and our findings pave the way for targeted biomarker discovery and drug development.

neuroscience↗

bioRxiv2017

Growth and extended survival of Escherichia coli O157:H7 in soil organic matter

Enterohaemorrhagic Escherichia coli such as serotype O157:H7 are a leading cause of food-associated outbreaks. While the primary reservoir is associated with cattle, plant foods have been associated as sources of human infection. E. coli is able to grow in the tissue of food plants such as spinach. While fecal contamination is the primary suspect, soil has been underestimated as a potential reservoir. Persistence of bacterial populations in open systems is the product of growth, death, predation, and competition. Here we report that E. coli O157:H7 can grow using the soluble compounds in soil, and characterize the effect of soil growth in the stationary phase proteome. E. coli 933D (stxII-) was cultured in Soil Extracted Soluble Organic Matter (SESOM) and the culturable count determined for 24 d. The proteomes of exponential and stationary phase populations were characterized by 2D gel electrophoresis and protein spots were identified by MALDI-TOF mass spectrometry. While LB controls displayed a death phase, SESOM grown population remained culturable for 24 d, indicating an altered physiological state with superior longevity. This was not due to decreased cell density on entry to stationary phase as 24h SESOM populations concentrated 10-fold retained their longevity. Principal component analysis showed that stationary phase proteomes from SESOM and LB were different. Differences included proteins involved in stress response, motility, membrane and wall composition, nutrient uptake, translation and protein turnover, and anabolic and catabolic pathways, indicating an altered physiological state of soil-grown cells entering stationary phase. The results suggest that E. coli may be a soil commensal that in absence of predation and competition maintains stable populations in soil.

microbiology↗