Biology subjects

Ugalde, C.

Publications and source records attributed to Ugalde, C..

3 recordsLinked to original sources

bioRxiv2024

Sprint interval exercise disrupts mitochondrial ultrastructure driving a unique mitochondrial stress response and remodelling in humans

Exercise remains the most effective lifestyle intervention to remodel the mitochondrial network and to prevent most non-communicable diseases. Despite this, the molecular mechanisms by which different exercise prescriptions dictate mitochondrial remodelling are poorly understood in humans. Here, we show that, compared to moderate-intensity continuous exercise (MICE), sprint-interval exercise (SIE) - a known time-efficient high-intensity exercise - leads to mitochondrial stress and activates the mitochondrial unfolded protein response (UPRmt). The SIE-specific signature is characterized by a morphological and ultrastructural mitochondrial disturbance, concurrent with the activation of the integrated stress response (ISR) and mitochondrial quality control (MQC) pathways. When the respective exercises are repeated over time (8 weeks), our results demonstrate that moderate-intensity continuous training (MICT) and sprint-interval training (SIT) lead to a divergent mitochondrial remodelling. MICT elicits a mitochondrial adaptation characterized by an increase in markers of mitochondrial content, complex I activity, and enrichment of proteins involved in tricarboxylic acid (TCA) cycle and oxidative phosphorylation (OXPHOS) system. On the other hand, SIT leads to proteomic enrichment of pathways involved in mitochondrial 1-Carbon metabolism and protein quality control, concurrently with improvements in mitochondrial respiratory function. Lastly, we have identified COX7A2L as a divergently regulated protein across groups, significantly accumulating in III2+IV1 respiratory supercomplexes only following SIT. In conclusion, our study provides mechanistic insights on how SIE and MICE divergently impact the post-exercise mitochondrial signalling, and subsequent long-term mitochondrial remodelling following training. These findings provide a strong basis for targeted exercise prescription to modulate specific mitochondrial adaptations in human skeletal muscle.

molecular biology↗

bioRxiv2020

CEDAR, an online resource for the reporting and exploration of complexome profiling data

Complexome profiling is an emerging omics approach that systematically interrogates the composition of protein complexes (the complexome) of a sample, by combining biochemical separation of native protein complexes with mass-spectrometry based quantitation proteomics. The resulting fractionation profiles hold comprehensive information on the abundance and composition of the complexome, and have a high potential for reuse by experimental and computational researchers. However, the lack of a central resource that provides access to these data, reported with adequate descriptions and an analysis tool, has limited their reuse. Therefore, we established the ComplexomE profiling DAta Resource (CEDAR, www3.cmbi.umcn.nl/cedar/), an openly accessible database for depositing and exploring mass spectrometry data from complexome profiling studies. Compatibility and reusability of the data is ensured by a standardized data and reporting format containing the "minimum information required for a complexome profiling experiment" (MIACE). The data can be accessed through a user-friendly web interface, as well as programmatically using the REST API portal. Additionally, all complexome profiles available on CEDAR can be inspected directly on the website with the profile viewer tool that allows the detection of correlated profiles and inference of potential complexes. In conclusion, CEDAR is a unique, growing and invaluable resource for the study of protein complex composition and dynamics across biological systems.

bioinformatics↗

bioRxiv2019

Misfolded α-synuclein causes hyperactive respiration without functional deficit in live neuronal cells

The misfolding and aggregation of the largely disordered protein, -synuclein, is a central pathogenic event that occurs in the synucleinopathies; a group of neurodegenerative disorders that includes Parkinsons disease. While there is a clear link between protein misfolding and neuronal vulnerability, the precise pathogenic mechanisms employed by disease-associated -synuclein are unresolved. Here, we studied the pathogenicity of misfolded -synuclein produced using the Protein Misfolding Cyclic Amplification (PMCA) assay. To do this, previous published methods were adapted to allow PMCA-induced protein fibrillization to occur under non-toxic conditions. Insight into potential intracellular targets of misfolded -synuclein was obtained using an unbiased lipid screen of 15 biologically relevant lipids that identified cardiolipin (CA) as a potential binding partner for PMCA-generated misfolded -synuclein. To investigate if such an interaction can impact the properties of -synuclein misfolding, protein fibrillization was carried out in the presence of the lipid. We show CA both accelerates the rate of -synuclein fibrillization and produces species that harbour enhanced resistance to proteolysis. Because CA is virtually exclusively expressed in the inner mitochondrial membrane, we then assessed the ability of these misfolded species to alter mitochondrial respiration in live non-transgenic SH-SY5Y neuroblastoma cells. Extensive analysis revealed misfolded -synuclein causes hyperactive mitochondrial respiration without causing any functional deficit. These data give strong support for the mitochondrion as a target for misfolded -synuclein and reveals persistent, hyperactive respiration as a potential up-stream pathogenic event associated with the synucleinopathies. Summary statementMisfolded -synuclein that was produced using the Protein Misfolding Cyclic Amplification (PMCA) assay was found to associate with cardiolipin and cause hyperactive respiration in neuronal cells.

neuroscience↗