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  1. Article ; Online: Can We Treat Neurodegenerative Proteinopathies by Enhancing Protein Degradation?

    Engelender, Simone / Stefanis, Leonidas / Oddo, Salvatore / Bellucci, Arianna

    Movement disorders : official journal of the Movement Disorder Society

    2022  Volume 37, Issue 7, Page(s) 1346–1359

    Abstract: Neurodegenerative proteinopathies are defined as a class of neurodegenerative disorders, with either genetic or sporadic age-related onset, characterized by the pathological accumulation of aggregated protein deposits. These mainly include Alzheimer's ... ...

    Abstract Neurodegenerative proteinopathies are defined as a class of neurodegenerative disorders, with either genetic or sporadic age-related onset, characterized by the pathological accumulation of aggregated protein deposits. These mainly include Alzheimer's disease (AD), Parkinson's disease (PD), amyotrophic lateral sclerosis (ALS), Huntington's disease (HD) as well as frontotemporal lobar degeneration (FTLD). The deposition of abnormal protein aggregates in the brain of patients affected by these disorders is thought to play a causative role in neuronal loss and disease progression. On that account, the idea of improving the clearance of pathological protein aggregates has taken hold as a potential therapeutic strategy. Among the possible approaches to pursue for reducing disease protein accumulation, there is the stimulation of the main protein degradation machineries of eukaryotic cells: the ubiquitin proteasomal system (UPS) and autophagy lysosomal pathway (ALP). Of note, several clinical trials testing the efficacy of either UPS- or ALP-active compounds are currently ongoing. Here, we discuss the main gaps and controversies emerging from experimental studies and clinical trials assessing the therapeutic efficacy of modulators of either the UPS or ALP in neurodegenerative proteinopathies, to gather whether they may constitute a real gateway from these disorders. © 2022 International Parkinson and Movement Disorder Society.
    MeSH term(s) Amyotrophic Lateral Sclerosis ; Frontotemporal Lobar Degeneration ; Humans ; Protein Aggregates ; Proteins/metabolism ; Proteolysis ; Ubiquitin/metabolism
    Chemical Substances Protein Aggregates ; Proteins ; Ubiquitin
    Language English
    Publishing date 2022-05-17
    Publishing country United States
    Document type Journal Article ; Research Support, Non-U.S. Gov't
    ZDB-ID 607633-6
    ISSN 1531-8257 ; 0885-3185
    ISSN (online) 1531-8257
    ISSN 0885-3185
    DOI 10.1002/mds.29058
    Database MEDical Literature Analysis and Retrieval System OnLINE

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  2. Article: SUMOylation in α-Synuclein Homeostasis and Pathology.

    Savyon, Mor / Engelender, Simone

    Frontiers in aging neuroscience

    2020  Volume 12, Page(s) 167

    Abstract: The accumulation and aggregation of α-synuclein are central to Parkinson's disease (PD), yet the molecular mechanisms responsible for these events are not fully understood. Post-translational modifications of α-synuclein regulate several of its ... ...

    Abstract The accumulation and aggregation of α-synuclein are central to Parkinson's disease (PD), yet the molecular mechanisms responsible for these events are not fully understood. Post-translational modifications of α-synuclein regulate several of its properties, including degradation, interaction with proteins and membranes, aggregation and toxicity. SUMOylation is a post-translational modification involved in various nuclear and extranuclear processes, such as subcellular protein targeting, mitochondrial fission and synaptic plasticity. Protein SUMOylation increases in response to several stressful situations, from viral infections to trauma. In this framework, an increasing amount of evidence has implicated SUMOylation in several neurodegenerative diseases, including PD. This review will discuss recent findings in the role of SUMOylation as a regulator of α-synuclein accumulation, aggregation and toxicity, and its possible implication in neurodegeneration that underlies PD.
    Keywords covid19
    Language English
    Publishing date 2020-06-25
    Publishing country Switzerland
    Document type Journal Article ; Review
    ZDB-ID 2558898-9
    ISSN 1663-4365
    ISSN 1663-4365
    DOI 10.3389/fnagi.2020.00167
    Database MEDical Literature Analysis and Retrieval System OnLINE

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  3. Article ; Online: α-Synuclein fate: proteasome or autophagy?

    Engelender, Simone

    Autophagy

    2012  Volume 8, Issue 3, Page(s) 418–420

    Abstract: The accumulation of α-synuclein is critical for the development of Parkinson disease (PD), and unraveling the mechanisms that regulate α-synuclein levels is key to understanding the pathophysiology of the disease. We recently found that USP9X ... ...

    Abstract The accumulation of α-synuclein is critical for the development of Parkinson disease (PD), and unraveling the mechanisms that regulate α-synuclein levels is key to understanding the pathophysiology of the disease. We recently found that USP9X deubiquitinates α-synuclein, and that this process determines the partition of α-synuclein between the proteasomal and autophagy pathways. By manipulating USP9X levels, we observed that monoubiquitinated α-synuclein is degraded by the proteasome, whereas deubiquitination of α-synuclein favors its degradation by autophagy. As USP9X levels and activity are decreased in α-synucleinopathy brains, USP9X may now represent a novel target for PD.
    MeSH term(s) Autophagy ; Humans ; Models, Biological ; Parkinson Disease/metabolism ; Parkinson Disease/pathology ; Proteasome Endopeptidase Complex/metabolism ; Signal Transduction ; Ubiquitin Thiolesterase/metabolism ; Ubiquitination ; alpha-Synuclein/metabolism
    Chemical Substances USP9X protein, human ; alpha-Synuclein ; Ubiquitin Thiolesterase (EC 3.4.19.12) ; Proteasome Endopeptidase Complex (EC 3.4.25.1)
    Language English
    Publishing date 2012-02-24
    Publishing country United States
    Document type Journal Article
    ZDB-ID 2454135-7
    ISSN 1554-8635 ; 1554-8627
    ISSN (online) 1554-8635
    ISSN 1554-8627
    DOI 10.4161/auto.19085
    Database MEDical Literature Analysis and Retrieval System OnLINE

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  4. Article ; Online: The Threshold Theory for Parkinson's Disease.

    Engelender, Simone / Isacson, Ole

    Trends in neurosciences

    2017  Volume 40, Issue 1, Page(s) 4–14

    Abstract: Parkinson's disease (PD) is recognized by the accumulation of α-synuclein within neurons. In contrast to the current ascending theory where α-synuclein would propagate from neuron to neuron, we now propose the threshold theory for PD based on evidence of ...

    Abstract Parkinson's disease (PD) is recognized by the accumulation of α-synuclein within neurons. In contrast to the current ascending theory where α-synuclein would propagate from neuron to neuron, we now propose the threshold theory for PD based on evidence of parallel degeneration of both central nervous system (CNS) and peripheral nervous system (PNS) in PD. The functional threshold is lower for the emergence of early symptoms before the classical motor symptoms of PD. This is due to the larger functional reserve of the midbrain dopamine and integrated basal ganglia motor systems to control movement. This threshold theory better accounts for the current neurobiology of PD symptom progression compared to the hypothesis that the disease ascends from the PNS to the CNS as proposed by Braak's hypothesis.
    MeSH term(s) Animals ; Brain/physiopathology ; Dopaminergic Neurons/physiology ; Humans ; Models, Neurological ; Parkinson Disease/physiopathology
    Language English
    Publishing date 2017-01
    Publishing country England
    Document type Journal Article ; Review
    ZDB-ID 282488-7
    ISSN 1878-108X ; 0378-5912 ; 0166-2236
    ISSN (online) 1878-108X
    ISSN 0378-5912 ; 0166-2236
    DOI 10.1016/j.tins.2016.10.008
    Database MEDical Literature Analysis and Retrieval System OnLINE

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  5. Article ; Online: Mic19 depletion impairs endoplasmic reticulum-mitochondrial contacts and mitochondrial lipid metabolism and triggers liver disease.

    Dong, Jun / Chen, Li / Ye, Fei / Tang, Junhui / Liu, Bing / Lin, Jiacheng / Zhou, Pang-Hu / Lu, Bin / Wu, Min / Lu, Jia-Hong / He, Jing-Jing / Engelender, Simone / Meng, Qingtao / Song, Zhiyin / He, He

    Nature communications

    2024  Volume 15, Issue 1, Page(s) 168

    Abstract: Endoplasmic reticulum (ER)-mitochondria contacts are critical for the regulation of lipid transport, synthesis, and metabolism. However, the molecular mechanism and physiological function of endoplasmic reticulum-mitochondrial contacts remain unclear. ... ...

    Abstract Endoplasmic reticulum (ER)-mitochondria contacts are critical for the regulation of lipid transport, synthesis, and metabolism. However, the molecular mechanism and physiological function of endoplasmic reticulum-mitochondrial contacts remain unclear. Here, we show that Mic19, a key subunit of MICOS (mitochondrial contact site and cristae organizing system) complex, regulates ER-mitochondria contacts by the EMC2-SLC25A46-Mic19 axis. Mic19 liver specific knockout (LKO) leads to the reduction of ER-mitochondrial contacts, mitochondrial lipid metabolism disorder, disorganization of mitochondrial cristae and mitochondrial unfolded protein stress response in mouse hepatocytes, impairing liver mitochondrial fatty acid β-oxidation and lipid metabolism, which may spontaneously trigger nonalcoholic steatohepatitis (NASH) and liver fibrosis in mice. Whereas, the re-expression of Mic19 in Mic19 LKO hepatocytes blocks the development of liver disease in mice. In addition, Mic19 overexpression suppresses MCD-induced fatty liver disease. Thus, our findings uncover the EMC2-SLC25A46-Mic19 axis as a pathway regulating ER-mitochondria contacts, and reveal that impairment of ER-mitochondria contacts may be a mechanism associated with the development of NASH and liver fibrosis.
    MeSH term(s) Mice ; Animals ; Lipid Metabolism/genetics ; Non-alcoholic Fatty Liver Disease/metabolism ; Endoplasmic Reticulum Stress ; Liver/metabolism ; Mitochondria/metabolism ; Liver Cirrhosis/pathology ; Endoplasmic Reticulum/metabolism
    Language English
    Publishing date 2024-01-02
    Publishing country England
    Document type Journal Article
    ZDB-ID 2553671-0
    ISSN 2041-1723 ; 2041-1723
    ISSN (online) 2041-1723
    ISSN 2041-1723
    DOI 10.1038/s41467-023-44057-6
    Database MEDical Literature Analysis and Retrieval System OnLINE

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  6. Article ; Online: Lipid and immune abnormalities causing age-dependent neurodegeneration and Parkinson's disease.

    Hallett, Penelope J / Engelender, Simone / Isacson, Ole

    Journal of neuroinflammation

    2019  Volume 16, Issue 1, Page(s) 153

    Abstract: This article describes pathogenic concepts and factors, in particular glycolipid abnormalities, that create cell dysfunction and synaptic loss in neurodegenerative diseases. By phenocopying lysosomal storage disorders, such as Gaucher disease and related ...

    Abstract This article describes pathogenic concepts and factors, in particular glycolipid abnormalities, that create cell dysfunction and synaptic loss in neurodegenerative diseases. By phenocopying lysosomal storage disorders, such as Gaucher disease and related disorders, age- and dose-dependent changes in glycolipid cell metabolism can lead to Parkinson's disease and related dementias. Recent results show that perturbation of sphingolipid metabolism can precede or is a part of abnormal protein handling in both genetic and idiopathic Parkinson's disease and Lewy body dementia. In aging and genetic predisposition with lipid disturbance, α-synuclein's normal vesicular and synaptic role may be detrimentally shifted toward accommodating and binding such lipids. Specific neuronal glycolipid, protein, and vesicular interactions create potential pathophysiology that is amplified by astroglial and microglial immune mechanisms resulting in neurodegeneration. This perspective provides a new logic for therapeutic interventions that do not focus on protein aggregation, but rather provides a guide to the complex biology and the common sequence of events that lead to age-dependent neurodegenerative disorders.
    MeSH term(s) Animals ; Brain/immunology ; Brain/metabolism ; Brain/pathology ; Humans ; Inflammation/immunology ; Inflammation/metabolism ; Inflammation/pathology ; Nerve Degeneration/immunology ; Nerve Degeneration/metabolism ; Nerve Degeneration/pathology ; Neurons/immunology ; Neurons/metabolism ; Neurons/pathology ; Parkinson Disease/immunology ; Parkinson Disease/metabolism ; Parkinson Disease/pathology ; alpha-Synuclein/metabolism ; tau Proteins/metabolism
    Chemical Substances alpha-Synuclein ; tau Proteins
    Language English
    Publishing date 2019-07-22
    Publishing country England
    Document type Journal Article ; Review
    ISSN 1742-2094
    ISSN (online) 1742-2094
    DOI 10.1186/s12974-019-1532-2
    Database MEDical Literature Analysis and Retrieval System OnLINE

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  7. Article ; Online: Ubiquitination of alpha-synuclein and autophagy in Parkinson's disease.

    Engelender, Simone

    Autophagy

    2008  Volume 4, Issue 3, Page(s) 372–374

    Abstract: alpha-Synuclein is mutated in Parkinson's disease (PD) and is found in cytosolic inclusions, called Lewy bodies, in sporadic forms of the disease. A fraction of alpha-synuclein purified from Lewy bodies is monoubiquitinated, but the role of this ... ...

    Abstract alpha-Synuclein is mutated in Parkinson's disease (PD) and is found in cytosolic inclusions, called Lewy bodies, in sporadic forms of the disease. A fraction of alpha-synuclein purified from Lewy bodies is monoubiquitinated, but the role of this monoubiquitination has been obscure. We now review recent data indicating a role of alpha-synuclein monoubiquitination in Lewy body formation and implicating the autophagic pathway in regulating these processes. The E3 ubiquitin-ligase SIAH is present in Lewy bodies and monoubiquitinates alpha-synuclein at the same lysines that are monoubiquitinated in Lewy bodies. Monoubiquitination by SIAH promotes the aggregation of alpha-synuclein into amorphous aggregates and increases the formation of inclusions within dopaminergic cells. Such effect is observed even at low monoubiquitination levels, suggesting that monoubiquitinated alpha-synuclein may work as a seed for aggregation. Accumulation of monoubiquitinated alpha-synuclein and formation of cytosolic inclusions is promoted by autophagy inhibition and to a lesser extent by proteasomal and lysosomal inhibition. Monoubiquitinated alpha-synuclein inclusions are toxic to cells and recruit PD-related proteins, such as synphilin-1 and UCH-L1. Altogether, the new data indicate that monoubiquitination might play an important role in Lewy body formation. Decreasing alpha- synuclein monoubiquitination, by preventing SIAH function or by stimulating autophagy, constitutes a new therapeutic strategy for Parkinson's disease.
    MeSH term(s) Autophagy/physiology ; Carrier Proteins/metabolism ; Humans ; Lewy Bodies/metabolism ; Nerve Tissue Proteins/metabolism ; Parkinson Disease/metabolism ; Parkinson Disease/pathology ; Ubiquitin Thiolesterase/metabolism ; Ubiquitin-Protein Ligases/metabolism ; Ubiquitination ; alpha-Synuclein/metabolism
    Chemical Substances Carrier Proteins ; Nerve Tissue Proteins ; SNCAIP protein, human ; UCHL1 protein, human ; alpha-Synuclein ; Ubiquitin-Protein Ligases (EC 2.3.2.27) ; Ubiquitin Thiolesterase (EC 3.4.19.12)
    Language English
    Publishing date 2008-01-18
    Publishing country United States
    Document type Journal Article ; Review
    ZDB-ID 2454135-7
    ISSN 1554-8635 ; 1554-8627
    ISSN (online) 1554-8635
    ISSN 1554-8627
    DOI 10.4161/auto.5604
    Database MEDical Literature Analysis and Retrieval System OnLINE

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  8. Article ; Online: Hypoxia-reprogramed megamitochondrion contacts and engulfs lysosome to mediate mitochondrial self-digestion.

    Hao, Tianshu / Yu, Jianglong / Wu, Zhida / Jiang, Jie / Gong, Longlong / Wang, Bingjun / Guo, Hanze / Zhao, Huabin / Lu, Bin / Engelender, Simone / He, He / Song, Zhiyin

    Nature communications

    2023  Volume 14, Issue 1, Page(s) 4105

    Abstract: Mitochondria are the key organelles for sensing oxygen, which is consumed by oxidative phosphorylation to generate ATP. Lysosomes contain hydrolytic enzymes that degrade misfolded proteins and damaged organelles to maintain cellular homeostasis. ... ...

    Abstract Mitochondria are the key organelles for sensing oxygen, which is consumed by oxidative phosphorylation to generate ATP. Lysosomes contain hydrolytic enzymes that degrade misfolded proteins and damaged organelles to maintain cellular homeostasis. Mitochondria physically and functionally interact with lysosomes to regulate cellular metabolism. However, the mode and biological functions of mitochondria-lysosome communication remain largely unknown. Here, we show that hypoxia remodels normal tubular mitochondria into megamitochondria by inducing broad inter-mitochondria contacts and subsequent fusion. Importantly, under hypoxia, mitochondria-lysosome contacts are promoted, and certain lysosomes are engulfed by megamitochondria, in a process we term megamitochondria engulfing lysosome (MMEL). Both megamitochondria and mature lysosomes are required for MMEL. Moreover, the STX17-SNAP29-VAMP7 complex contributes to mitochondria-lysosome contacts and MMEL under hypoxia. Intriguingly, MMEL mediates a mode of mitochondrial degradation, which we termed mitochondrial self-digestion (MSD). Moreover, MSD increases mitochondrial ROS production. Our results reveal a mode of crosstalk between mitochondria and lysosomes and uncover an additional pathway for mitochondrial degradation.
    MeSH term(s) Humans ; Lysosomes ; Mitochondria ; Hypoxia ; Oxygen ; Digestion
    Chemical Substances Oxygen (S88TT14065)
    Language English
    Publishing date 2023-07-11
    Publishing country England
    Document type Journal Article ; Research Support, Non-U.S. Gov't
    ZDB-ID 2553671-0
    ISSN 2041-1723 ; 2041-1723
    ISSN (online) 2041-1723
    ISSN 2041-1723
    DOI 10.1038/s41467-023-39811-9
    Database MEDical Literature Analysis and Retrieval System OnLINE

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  9. Article ; Online: Mic19 depletion impairs endoplasmic reticulum-mitochondrial contacts and mitochondrial lipid metabolism and triggers liver disease

    Jun Dong / Li Chen / Fei Ye / Junhui Tang / Bing Liu / Jiacheng Lin / Pang-Hu Zhou / Bin Lu / Min Wu / Jia-Hong Lu / Jing-Jing He / Simone Engelender / Qingtao Meng / Zhiyin Song / He He

    Nature Communications, Vol 15, Iss 1, Pp 1-

    2024  Volume 16

    Abstract: Abstract Endoplasmic reticulum (ER)-mitochondria contacts are critical for the regulation of lipid transport, synthesis, and metabolism. However, the molecular mechanism and physiological function of endoplasmic reticulum-mitochondrial contacts remain ... ...

    Abstract Abstract Endoplasmic reticulum (ER)-mitochondria contacts are critical for the regulation of lipid transport, synthesis, and metabolism. However, the molecular mechanism and physiological function of endoplasmic reticulum-mitochondrial contacts remain unclear. Here, we show that Mic19, a key subunit of MICOS (mitochondrial contact site and cristae organizing system) complex, regulates ER-mitochondria contacts by the EMC2-SLC25A46-Mic19 axis. Mic19 liver specific knockout (LKO) leads to the reduction of ER-mitochondrial contacts, mitochondrial lipid metabolism disorder, disorganization of mitochondrial cristae and mitochondrial unfolded protein stress response in mouse hepatocytes, impairing liver mitochondrial fatty acid β-oxidation and lipid metabolism, which may spontaneously trigger nonalcoholic steatohepatitis (NASH) and liver fibrosis in mice. Whereas, the re-expression of Mic19 in Mic19 LKO hepatocytes blocks the development of liver disease in mice. In addition, Mic19 overexpression suppresses MCD-induced fatty liver disease. Thus, our findings uncover the EMC2-SLC25A46-Mic19 axis as a pathway regulating ER-mitochondria contacts, and reveal that impairment of ER-mitochondria contacts may be a mechanism associated with the development of NASH and liver fibrosis.
    Keywords Science ; Q
    Subject code 570
    Language English
    Publishing date 2024-01-01T00:00:00Z
    Publisher Nature Portfolio
    Document type Article ; Online
    Database BASE - Bielefeld Academic Search Engine (life sciences selection)

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  10. Article ; Online: Hypoxia-reprogramed megamitochondrion contacts and engulfs lysosome to mediate mitochondrial self-digestion

    Tianshu Hao / Jianglong Yu / Zhida Wu / Jie Jiang / Longlong Gong / Bingjun Wang / Hanze Guo / Huabin Zhao / Bin Lu / Simone Engelender / He He / Zhiyin Song

    Nature Communications, Vol 14, Iss 1, Pp 1-

    2023  Volume 17

    Abstract: Abstract Mitochondria are the key organelles for sensing oxygen, which is consumed by oxidative phosphorylation to generate ATP. Lysosomes contain hydrolytic enzymes that degrade misfolded proteins and damaged organelles to maintain cellular homeostasis. ...

    Abstract Abstract Mitochondria are the key organelles for sensing oxygen, which is consumed by oxidative phosphorylation to generate ATP. Lysosomes contain hydrolytic enzymes that degrade misfolded proteins and damaged organelles to maintain cellular homeostasis. Mitochondria physically and functionally interact with lysosomes to regulate cellular metabolism. However, the mode and biological functions of mitochondria-lysosome communication remain largely unknown. Here, we show that hypoxia remodels normal tubular mitochondria into megamitochondria by inducing broad inter-mitochondria contacts and subsequent fusion. Importantly, under hypoxia, mitochondria-lysosome contacts are promoted, and certain lysosomes are engulfed by megamitochondria, in a process we term megamitochondria engulfing lysosome (MMEL). Both megamitochondria and mature lysosomes are required for MMEL. Moreover, the STX17-SNAP29-VAMP7 complex contributes to mitochondria-lysosome contacts and MMEL under hypoxia. Intriguingly, MMEL mediates a mode of mitochondrial degradation, which we termed mitochondrial self-digestion (MSD). Moreover, MSD increases mitochondrial ROS production. Our results reveal a mode of crosstalk between mitochondria and lysosomes and uncover an additional pathway for mitochondrial degradation.
    Keywords Science ; Q
    Subject code 610
    Language English
    Publishing date 2023-07-01T00:00:00Z
    Publisher Nature Portfolio
    Document type Article ; Online
    Database BASE - Bielefeld Academic Search Engine (life sciences selection)

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