Biology subjects

Tricou, L.-P.

Publications and source records attributed to Tricou, L.-P..

2 recordsLinked to original sources

bioRxiv2023

Staphylococcus aureus can use an alternative pathway to be internalized by osteoblasts in absence of β1 integrins

Staphylococcus aureus main internalization mechanism in osteoblasts relies on a tripartite interaction between bacterial fibronectin-binding proteins, extracellular matrix soluble fibronectin, and osteoblasts {beta}1 integrins. Caveolins, and particularly caveolin-1, have shown to limit the plasma membrane microdomain mobility, and consequently reduce the uptake of S. aureus in keratinocytes. In this study, we aimed to deepen our understanding of the molecular mechanisms underlying S. aureus internalization in osteoblasts. Mechanistically, S. aureus internalization requires endosomal recycling {beta}1 integrins as well as downstream effectors such as Src, Rac1, and PAK1. Surprisingly, in {beta}1 integrin deficient osteoblasts, S. aureus internalization is restored when Caveolin-1 is absent and requires v{beta}3/v{beta}5 integrins as backup fibronectin receptors. Altogether, our data support that {beta}1 integrins regulate the level of detergent-resistant membrane at the plasma membrane in a an endosomal and Caveolin-1 dependent manner. SUMMARY STATEMENTStaphylococcus aureus can be internalized by osteoblasts via a different mechanism than the main 5{beta}1/fibronectin/fibronectin-binding protein that likely involves v{beta}3 or v{beta}5 integrin.

cell biology↗

bioRxiv2023

Fluorescent pH-sensing bandage for point-of-care wound diagnostics

Diabetic foot ulcers (DFUs) are a serious and prevalent complication of diabetes. Current diagnostic options are limited to macroscopic wound analysis such as wound size, depth, and infection. Molecular diagnostics promise to improve DFU diagnosis, staging, and assessment of treatment response. Here, we developed a rapid and easy-to-use fluorescent pH-sensing bandage for wound diagnostics. In a fluorescent dye screen, we identified pyranine as the lead compound due to its suitable pH-sensing properties in the clinically relevant pH range of 6 to 9. To minimize the release of this dye into the wound bed, we screened a library of ionic microparticles and found a strong adhesion of the anionic dye to a cationic polymeric microparticle. These dye-loaded microparticles showed a strong fluorescence response in the clinically relevant pH range of 6 to 9 and a dye release below 1% after one day in biological media. The dye-loaded microparticles were subsequently encapsulated in a calcium alginate hydrogel to minimize the interaction of the microparticles with the wound tissue. This pH-sensing diagnostic wound dressing was tested on full thickness dorsal wounds of mice, and a linear fluorescence response (R2 = 0.9909) to clinically relevant pH values was observed. These findings encourage further development of this pH-sensing system for molecular diagnostics in DFUs.

pharmacology and toxicology↗