Biology subjects

Moisoi, N.

Publications and source records attributed to Moisoi, N..

3 recordsLinked to original sources

bioRxiv2025

Detecting Mitochondrial Free Radicals with Quantum Sensors: From Organelles to a D. melanogaster Model of Neurodegeneration

This study identifies a distinct free radical signature in a D. melanogaster model of Parkinsons Disease, successfully differentiating Pink1-deficient flies from wild-type controls. This insight was achieved using a robust quantum sensing methodology for the selective detection of free radicals in biological systems. Our approach utilizes optically detected magnetic resonance (ODMR) and magnetic modulation (MM) protocols with nanodiamond nitrogen-vacancy (NV) centres. Selective identification is achieved using the spin probe TEMPOL, a cell-permeable superoxide dismutase 2 (SOD2) mimic that initially quenches the photoluminescence signal. Upon scavenging free radicals like hydroxyl and superoxide, TEMPOL is converted to a diamagnetic adduct, restoring the contrast and thus enabling quantitative detection. The approach was first validated in a chemical system with radical generation confirmed by electron paramagnetic resonance (EPR) spectroscopy. It was then demonstrated across biological scales, from isolated mitochondria and whole glioblastoma cells to the Drosophila model. In these studies, high-resolution respirometry revealed distinct free radical signatures, and findings were compared with NV T1 relaxometry. This work provides new biophysical insight into mitochondrial dysfunction, demonstrating a distinct free radical signature in a neurodegeneration model and connecting it to specific metabolic states.

cell biology↗

bioRxiv2022

A method to assess the mitochondrial respiratory capacity of complexes I and II from frozen tissue using the Oroboros O2k-FluoRespirometer

High-resolution respirometry methods allow for the assessment of oxygen consumption by the electron transfer systems within cells, tissue samples, and isolated mitochondrial preparations. As mitochondrial integrity is compromised by the process of cryopreservation, these methods have been limited to fresh samples. Here we present a simple method to assess the activity of mitochondria respiratory complexes I and II in previously cryopreserved murine skeletal muscle tissue homogenates, as well as previously frozen D. melanogaster, as a function of oxygen consumption.

cell biology↗

bioRxiv2021

The dysregulated Pink1- Drosophila mitochondrial proteome is partially corrected with exercise.

One of the genes which has been linked to the onset of juvenile/early onset Parkinsons disease (PD) is PINK1. There is evidence that supports the therapeutic potential of exercise in the alleviation of PD symptoms. It is possible that exercise may enhance synaptic plasticity, protect against neuro-inflammation and modulate L-Dopa regulated signalling pathways. We explored the effects of exercise on Pink1 deficient Drosophila melanogaster which undergo neurodegeneration and muscle degeneration. We used a power-tower type exercise platform to deliver exercise activity to Pink1- and age matched wild-type flies. Mitochondrial proteomic profiles responding to exercise were obtained. Of the 516 proteins identified, 105 proteins had different levels between Pink1- and wild-type (WT) non-exercised D. melanogaster. Gene ontology enrichment analysis and STRING network analysis highlighted proteins and pathways with altered expression within the mitochondrial proteome. Comparison of the Pink1- exercised proteome to WT proteomes showed that exercising the Pink1- flies caused their proteomic profile to return towards wild-type levels.

cell biology↗