In Ageing, a pair of researchers has printed a perspective connecting fat (lipid) accumulation and cellular senescence in neurons to Parkinson’s disease.
α-syn, however not simply α-syn
Parkinson’s illness is characterised by the lack of a selected inhabitants of neurons: the dopaminergic neurons within the substantia nigra, part of the mind that governs motion [1]. The following issues with primary motion are accompanied by cognitive decline and despair.
On the mobile degree, a key hallmark is the buildup of alpha-synuclein (α-syn) aggregates that result in Lewy our bodies. That is linked to lipid metabolism, and analysis has discovered that stressors that encourage Parkinson’s illness additionally encourage lipid accumulation [2]. Ageing is, after all, the strongest danger issue for Parkinson’s, however genetic elements additionally play a job: essentially the most well-documented of those is a mutation of GBA, a gene that encodes for β-glucocerebrosidase (GCase), an enzyme that breaks down glucosylceramides (GluCer), a category of lipids.
This relationship seems to be a robust one: elevated quantities of GluCer are related to sharp cognitive decline in Parkinson’s sufferers, and a scarcity of GCase seems to be the trigger [3]. Dysfunction of the lysosomes [4], which break down protein, and reactions with dopamine itself [5] can also contribute to this enhance in GluCer.
The genetic hyperlink
These researchers had discovered that that is additionally linked to mobile senescence [6]. SATB1, a gene that has additionally been discovered to be a danger issue for Parkinson’s, downregulates the microRNA miR-22-3p, which downregulates GBA. Subsequently, a discount in SATB1 results in extra GluCer and senescence within the neurons. In that paper, these researchers had handled human neurons with GluCer and located that it drove them senescent and inspired α-syn aggregation. A earlier paper had additionally discovered that lipid droplet accumulation and mobile senescence are linked [7].
This connection between lipid droplets and senescence additionally seems to contain α-syn. Lipid droplets themselves encourage its manufacturing, and α-syn by itself has been discovered to drive the related cells senescent [8]. The researchers notice that this can be depending on cell kind: a discount in SATB1 drives dopaminergic neurons, that are particularly harmed by Parkinson’s illness, senescent [9], whereas it doesn’t drive different kinds of neurons senescent. These neurons, specifically, are depending on the operate of lysosomes.
This distinction in particular cell kind seems to be why Parkinson’s is proscribed to such a small and important inhabitants of neurons. Most critically, it provides researchers a possible new goal for Parkinson’s therapies. If GBA or lipid accumulation could be immediately affected along with α-syn, it is likely to be potential for Parkinson’s illness to be handled rather more successfully.
Literature
[1] Dauer, W., & Przedborski, S. (2003). Parkinson’s illness: mechanisms and fashions. Neuron, 39(6), 889-909.
[2] Alecu, I., & Bennett, S. A. (2019). Dysregulated lipid metabolism and its function in α-synucleinopathy in Parkinson’s illness. Frontiers in neuroscience, 13, 328.
[3] Huh, Y. E., Park, H., Chiang, M. S. R., Tuncali, I., Liu, G., Locascio, J. J., … & Scherzer, C. R. (2021). Glucosylceramide in cerebrospinal fluid of sufferers with GBA-associated and idiopathic Parkinson’s illness enrolled in PPMI. npj Parkinson’s Illness, 7(1), 102.
[4] Arévalo, N. B., Lamaizon, C. M., Cavieres, V. A., Burgos, P. V., Álvarez, A. R., Yañez, M. J., & Zanlungo, S. (2022). Neuronopathic Gaucher illness: Past lysosomal dysfunction. Frontiers in Molecular Neuroscience, 15, 934820.
[5] Riessland, M., Kolisnyk, B., & Greengard, P. (2017). Reactive dopamine results in triple bother in nigral neurons. Biochemistry, 56(49), 6409-6410.
[6] Russo, T., Kolisnyk, B., BS, A., Plessis‐Belair, J., Kim, T. W., Martin, J., … & Riessland, M. (2024). The SATB1‐MIR22‐GBA axis mediates glucocerebroside accumulation inducing a mobile senescence‐like phenotype in dopaminergic neurons. Ageing cell, 23(4), e14077.
[7] Millner, A., & Atilla-Gokcumen, G. E. Lipid Gamers of Mobile Senescence. Metabolites 2020, 10, 339.
[8] Verma, D. Ok., Search engine optimisation, B. A., Ghosh, A., Ma, S. X., Hernandez-Quijada, Ok., Andersen, J. Ok., … & Kim, Y. H. (2021). Alpha-synuclein preformed fibrils induce mobile senescence in Parkinson’s illness fashions. Cells, 10(7), 1694.
[9] Riessland, M., Kolisnyk, B., Kim, T. W., Cheng, J., Ni, J., Pearson, J. A., … & Greengard, P. (2019). Lack of SATB1 induces p21-dependent mobile senescence in post-mitotic dopaminergic neurons. Cell stem cell, 25(4), 514-530.
