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Biology subjects

Lebas, B.

Publications and source records attributed to Lebas, B..

3 recordsLinked to original sources

Plant Cell Wall Enzymatic Hydrolysis: Predicting Yield Dynamics from Autofluorescence and Morphological Temporal Changes

Enzymatic hydrolysis of plant cell walls into fermentable sugars is a critical step in biotechnological conversion, yet efficiency is limited by cell wall recalcitrance. Predicting conversion yields of cell wall-derived sugars during hydrolysis is challenging due to the complex underlying mechanisms and the labor-intensive nature of conventional assays. This study introduces an innovative pipeline that accurately quantifies cell wall autofluorescence intensity and morphological descriptors during enzymatic hydrolysis. The pipeline incorporates a novel adaptive drift compensation strategy which dynamically adjusts to the progression and extent of deconstruction ensuring robust analysis. Applied to time-lapse images of spruce wood enzymatic deconstruction, the pipeline revealed strong negative correlations of conversion yields during hydrolysis with both the dynamics of cell wall autofluorescence intensity and morphological descriptors. Phase-specific analysis uncovered distinct correlation patterns dependent on hydrolysis stage and sugar type. This non-destructive pipeline eliminates the need for extensive sampling and time-consuming chemical assays, establishing plant cell wall autofluorescence and morphological descriptors as accurate predictive real-time biomarkers of dynamics of sugar conversion yields. The findings provide a framework for accelerating the development of optimized biotechnological conversion processes.

biochemistry↗

Lymphangiogenesis in Abdominal Aortic Aneurysm regulates the balance between resident and circulating eosinophils via a 15-lipoxygenase-dependent mechanism

The abdominal aortic aneurysm (AAA) is a chronic degeneration of the aortic wall involving an inflammatory response, aberrant remodeling of the extracellular matrix, and the development of microvessels. Among these, lymphatic capillaries develop in the adventitia. However, the role of lymphangiogenesis in AAA remains unclear. Here, we confirmed the development of lymphatic vessels in both human and mouse AAA. This was associated with a decrease in specialized pro-resolving mediators (SPM) generated by 15-Lipoxygenase (15LO), an enzyme that controls resolution of inflammation in lymphatic diseases. Lymphatic selective depletion of 15LO (Prox1cre; Alox15fl/fl mice) increased both systemic and resident eosinophil (EOS) accumulation in lesions, but had no effect on other immune cell populations. Mechanistically, in vitro depletion of 15LO in lymphatic endothelial cells (LEC) significantly decreased EOS adhesion. In contrast, 15LO LEC depletion improved transendothelial migration. In vivo, the rescue of 15LO using lentivector transduction modified the balance between resident and systemic EOS in favor of the resident ones and reduced the AAA lesion. Altogether, we show that lymphatic vessels play a protective role in AAA by regulating the trafficking of EOS into the aorta wall.

cell biology↗

A Distinct Autofluorescence Distribution Pattern Marks Enzymatic Deconstruction of Plant Cell Wall

Achieving an economically viable transformation of plant cell walls into bioproducts requires a comprehensive understanding of enzymatic deconstruction. Microscale quantitative analysis offers a relevant approach to enhance our understanding of cell wall hydrolysis, but becomes challenging under high deconstruction conditions. This study comprehensively addresses the challenges of quantifying the impact of extensive enzymatic deconstruction on plant cell wall at microscale. Investigation of highly deconstructed spruce wood provided spatial profiles of cell walls during hydrolysis with a remarkable precision. A distinct cell wall autofluorescence distribution pattern marking enzymatic hydrolysis along with an asynchronous impact of hydrolysis on cell wall structure, with cell wall volume reduction preceding cell wall accessible surface area decrease, were revealed. This study provides novel insights into enzymatic deconstruction of cell wall at under-investigated cell scale, and a robust computational pipeline applicable to diverse biomass species and pretreatment types for assessing hydrolysis impact and efficiency.

biochemistry↗