Biology subjects

Bergaglio, T.

Publications and source records attributed to Bergaglio, T..

3 recordsLinked to original sources

bioRxiv2024

On Levodopa interactions with brain disease proteins at the nanoscale

The cerebral accumulation of -Synuclein (-Syn) and amyloid {beta}-1-42 (A{beta}-42) proteins are known to play a crucial role in the pathology of neurocognitive disorders such as Parkinsons disease (PD). Currently, Levodopa (L-dopa) is the dopamine replacement therapy for treating bradykinetic symptoms visible in PD patients. Here, we use atomic force microscopy to evidence at nanometer length scales the effects of L-dopa on the morphology of -Syn and A{beta}-42 protein fibrils. L-dopa treatment reduces the length and diameter of both types of protein fibrils, with a stark reduction observed for A{beta}-42 both in physiological buffer and human spinal fluid. The insights gained on A{beta}-42 fibril disassembly from the nanoscale imaging experiments are substantiated using atomic-scale molecular dynamics simulations. Our results reveal the mechanism governing L-dopa-driven reversal of protein aggregation, which may be useful in drug design of small molecule drugs for potentially treating neurocognitive disorders and provide leads for designing chemical effector-mediated disassembly of protein architectures.

neuroscience↗

bioRxiv2023

Digital holo-tomographic 3D maps of COVID-19 microclots in blood to assess disease severity

The coronavirus disease 2019 (COVID-19) has impacted health globally. Cumulative evidence points to long-term effects of COVID-19 such as cardiovascular and cognitive disorders diagnosed in patients even after the recovery period. In particular, micrometer-sized blood clots and hyperactivated platelets have been identified as potential indicators of long COVID. Here we resolve individual microclot structures in platelet-rich plasma of donors with different subphenotypes of COVID-19 in a label-free manner, using 3D digital holo-tomographic microscopy (DHTM). Based on 3D refractive index (RI) tomograms, the size, dry mass, and prevalence of microclot composites were quantified and then parametrically differentiated from fibrin-rich microclots and platelet aggregates in the plasma of COVID-19 donors. Importantly, fewer microclots and platelet aggregates were detected in the plasma of healthy controls when compared to COVID-19 donors. Our work highlights the utility of integrating DHTM in clinical settings that may allow the detection of individuals at risk of developing microvascular thrombotic disorders and for monitoring the efficiency of prescribed treatments by screening plasma samples.

pathology↗

bioRxiv2022

Label-free digital holotomography reveals ibuprofen-induced morphological changes to red blood cells

Understanding the dose-dependent effect of over-the-counter drugs on red blood cells (RBCs) is crucial for hematology and digital pathology. Yet, it is challenging to continuously record the real-time, drug-induced nanoscopic shape changes of RBCs in a label-free manner. Here, we demonstrate digital holotomography (DHTM) enabled real-time, label-free concentration-dependent and time-dependent monitoring of ibuprofen on RBCs from a healthy donor. The RBCs are segmented based on 3D and 4D refractive index tomograms and their morphological and chemical parameters are retrieved with their shapes classified using machine learning. We directly observed the formation and motion of spicules on the RBC membranes when aqueous solutions of ibuprofen were drop cast on wet blood, creating rough-membraned echinocyte forms. At low concentrations of 0.25-0.50 mM, the ibuprofen-induced morphological change was transient but at high concentrations (1.5-3 mM) the spiculated RBC remained over a period of up to 1.5 hours. Molecular simulations confirmed that aggregates of ibuprofen molecules at high concentrations significantly disrupted the RBC membrane structural integrity and lipid order, but produced negligible effect at low ibuprofen concentrations. Control experiments on the effect of urea, hydrogen peroxide and aqueous solutions on RBCs showed zero spicule formation. Our work elucidates the dose-dependent chemical effects on RBCs using label-free microscopes that can be deployed for the rapid detection of overdosage of over-the-counter and prescribed drugs. SignificanceThe interaction between drugs and blood cells is an important field of study in order to understand the risk for drug-induced haematological adverse effects. Using digital holo-tomographic microscopy (DHTM), we can resolve the real-time effect of medications on the morphological and chemical properties of red blood cells with high spatial and temporal resolution and in a label-free manner. We show that our approach can be used as a haematology platform for the diagnosis of blood disorders and for monitoring the dose-dependent effect of prescribed and over-the-counter medications in a cost-effective manner, with significant implications for its applicability in resource-limited settings and in the field of personalized medicine.

cell biology↗