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Biology subjects

Chroscicki, P.

Publications and source records attributed to Chroscicki, P..

3 recordsLinked to original sources

miR-155-5p/miR-674-3p presence in peripheral blood leukocytes and relative proportion of white blood cell types as biomarkers of asymptomatic and symptomatic phases of temporal lobe epilepsy

Epilepsy frequently develops as a result of brain insult, for example, brain injury or stroke. Currently, there are no tools allowing us to predict which trauma patients will eventually develop epilepsy. There is evidence that microRNAs levels are altered in the blood, making them attractive candidates for peripheral biomarkers of epilepsy. We analyzed white blood cell subpopulations containing miR-155-5p and miR-674-3p, in control and stimulated animals and in control and symptomatic or asymptomatic animals in the amygdala stimulation model. The first proposed early biomarker of epilepsy is the relative proportion of CD45RA+ B cells containing miR-155-5p and/or miR-674-3p. Others are increased number of CD45RA+ B cells containing either miR-155-5p or miR-155-5p and miR-674-3p together or decreased number of CD161+ NK cells not containing miR-155-5p nor miR-674-3p. Additionally, we found that the decreased number of CD4+ T cells can be used as a potential biomarker for identifying epileptic animals with symptomatic epilepsy.

neuroscience↗

Cytosolic aggregation of mitochondrial proteins disrupts cellular homeostasis by stimulating other proteins aggregation

Mitochondria are organelles with their own genomes, but they rely on the import of nuclear-encoded proteins that are translated by cytosolic ribosomes. Therefore, it is important to understand whether failures in the mitochondrial uptake of these nuclear-encoded proteins can cause proteotoxic stress and identify response mechanisms that may counteract it. Here, we report that upon impairments in mitochondrial protein import, high-risk precursor and immature forms of mitochondrial proteins form aberrant deposits in the cytosol. These deposits then cause further cytosolic accumulation and consequently aggregation of other mitochondrial proteins and disease-related proteins, including -synuclein and amyloid {beta}. This aggregation triggers a cytosolic protein homeostasis imbalance that is accompanied by specific molecular chaperone responses at both the transcriptomic and protein levels. Altogether, our results provide evidence that mitochondrial dysfunction, specifically protein import defects, contributes to impairments in protein homeostasis, thus revealing a possible molecular mechanism by which mitochondria are involved in neurodegenerative diseases.

molecular biology↗

Cytosolic ribosomes on the surface of mitochondria

By electron cryo-tomography and subtomogram averaging, translation-arrested ribosomes were used to depict the clustered organisation of the TOM complex on the surface of mitochondria, corroborating earlier reports of localized translation. Ribosomes were shown to interact specifically with the TOM complex and nascent chain binding was crucial for ribosome recruitment and stabilization. Ribosomes were bound to the membrane in discrete clusters, often in the vicinity of the crista junctions. This interaction highlights how protein synthesis may be coupled with transport, and the importance of spatial organization for efficient mitochondrial protein import.

cell biology↗