scholarly journals Constitutive Silencing of LRRK2 Kinase Activity Leads to Early Glucocerebrosidase Deregulation and Late Impairment of Autophagy in vivo

2021 ◽  
Author(s):  
Federica Albanese ◽  
Daniela Mercatelli ◽  
Luca Finetti ◽  
Giulia Lamonaca ◽  
Sara Pizzi ◽  
...  
Keyword(s):  
Parkinson’S Disease ◽  
Parkinson's Disease ◽  
Kinase Activity ◽  
Kinase Inhibitor ◽  
Autophagic Flux ◽  
Wild Type ◽  
Knock Out ◽  
Lrrk2 Kinase ◽  
Chaperone Mediated Autophagy

Abstract Background: Mutations in leucine-rich repeat kinase 2 (LRRK2) are associated with familiar and sporadic Parkinson’s disease. LRRK2 modulates the autophagy-lysosome pathway (ALP), a clearance process subserving the quality control of cellular proteins and organelles. Since dysfunctional ALP might lead to α-synuclein accumulation and, hence, Parkinson’s disease, LRRK2 kinase modulation of ALP, its age-dependence and relation with pSer129 a-synuclein inclusions in striatal and nigral neurons were investigated in vivo. Methods: Striatal ALP markers were analyzed by Western blotting in 3, 12 and 20-month-old LRRK2 G2019S knock-in mice (bearing enhanced kinase activity), LRRK2 knock-out mice, LRRK2 D1994S knock-in (kinase-dead) mice and wild-type controls. The lysosomotropic agent chloroquine was used to investigate the autophagic flux in vivo. Quantitative Real-time PCR was used to quantify the transcript levels of key ALP genes. The activity of the lysosomal enzyme glucocerebrosidase was measured using enzymatic assay. Immunohistochemistry was used to co-localize LC3B puncta with pSer129 a-synuclein inclusion in striatal MAP-positive and nigral TH-positive neurons. Results: No genotype differences in macroautophagy and chaperone-mediated autophagy markers were observed at 3 months. Conversely, increase of LC3-I, p62, LAMP2 and GAPDH levels, decrease of p-mTOR levels and downregulation of mTOR and TFEB expression was observed in 12-month-old kinase-dead mice. The LC3-II/LC3-I ratio was reduced following administration of chloroquine, suggesting a defective autophagic flux. G2019S knock-in mice showed LAMP2 accumulation and downregulation of ALP key genes MAP1LC3B, LAMP2, mTOR, TFEB and GBA1. Subacute administration of the LRRK2 kinase inhibitor MLi-2 in wild-type and G2019S knock-in mice did not replicate the pattern of kinase-dead mice. Lysosomal glucocerebrosidase activity was increased in 3 and 12-month-old knock-out and kinase-dead mice, and GBA1 expression reduced in 12-month-old G2019S knock-in mice. Immunofluorescence revealed a dissociation between LC3B puncta accumulation and pSer129 a-synuclein inclusions in striatal neurons of kinase-dead and G2019S knock-in mice. Conclusions: We conclude that constitutive LRRK2 kinase silencing results in early deregulation of GCase activity followed by late impairment of macroautophagy and chaperone-mediated autophagy. In G2019S knock-in mice, pSer129 a-synuclein inclusions observed under basal conditions appear unrelated to autophagy impairment.

scholarly journals Pharmacological rescue of impaired mitophagy in Parkinson’s disease-related LRRK2 G2019S knock-in mice

2020 ◽  
Author(s):  
Francois Singh ◽  
Alan R. Prescott ◽  
Graeme Ball ◽  
Alastair D. Reith ◽  
Ian G. Ganley
Keyword(s):  
Parkinson’S Disease ◽  
Parkinson's Disease ◽  
Kinase Inhibitors ◽  
Kinase Inhibitor ◽  
Neurodegenerative Disorder ◽  
Reporter Mice ◽  
Lrrk2 G2019s ◽  
Lrrk2 Kinase

AbstractParkinson’s disease (PD) is a major and progressive neurodegenerative disorder, yet the biological mechanisms involved in its aetiology are poorly understood. Evidence links this disorder with mitochondrial dysfunction and/or impaired lysosomal degradation – key features of the autophagy of mitochondria, known as mitophagy. Here we investigated the role of LRRK2, a protein kinase frequently mutated in PD, on this process in vivo. Using mitophagy and autophagy reporter mice, bearing either knockout of LRRK2 or expressing the pathogenic kinase-activating G2019S LRRK2 mutation, we found that basal mitophagy was specifically altered in clinically relevant cells and tissues. Our data show that basal mitophagy inversely correlates with LRRK2 kinase activity in vivo. In support of this, use of distinct LRRK2 kinase inhibitors in cells increased basal mitophagy, and a CNS penetrant LRRK2 kinase inhibitor, GSK3357679A, rescued the mitophagy defects observed in LRRK2 G2019S mice. This study provides the first in vivo evidence that pathogenic LRRK2 directly impairs basal mitophagy, a process with strong links to idiopathic Parkinson’s disease, and demonstrates that pharmacological inhibition of LRRK2 is a rational mitophagy-rescue approach and potential PD therapy.

scholarly journals LRRK2 and the Endolysosomal System in Parkinson’s Disease

2020 ◽  
Vol 10 (4) ◽  
pp. 1271-1291
Author(s):  
Madalynn L. Erb ◽  
Darren J. Moore
Keyword(s):  
Parkinson’S Disease ◽  
Parkinson's Disease ◽  
Kinase Activity ◽  
Neuronal Damage ◽  
Distinct Cell Type ◽  
In Vivo Models ◽  
Network Maintenance ◽  
Lrrk2 Kinase ◽  
Lrrk2 Kinase Activity

Mutations in leucine-rich repeat kinase 2 (LRRK2) cause autosomal dominant familial Parkinson’s disease (PD), with pathogenic mutations enhancing LRRK2 kinase activity. There is a growing body of evidence indicating that LRRK2 contributes to neuronal damage and pathology both in familial and sporadic PD, making it of particular interest for understanding the molecular pathways that underlie PD. Although LRRK2 has been extensively studied to date, our understanding of the seemingly diverse functions of LRRK2 throughout the cell remains incomplete. In this review, we discuss the functions of LRRK2 within the endolysosomal pathway. Endocytosis, vesicle trafficking pathways, and lysosomal degradation are commonly disrupted in many neurodegenerative diseases, including PD. Additionally, many PD-linked gene products function in these intersecting pathways, suggesting an important role for the endolysosomal system in maintaining protein homeostasis and neuronal health in PD. LRRK2 activity can regulate synaptic vesicle endocytosis, lysosomal function, Golgi network maintenance and sorting, vesicular trafficking and autophagy, with alterations in LRRK2 kinase activity serving to disrupt or regulate these pathways depending on the distinct cell type or model system. LRRK2 is critically regulated by at least two proteins in the endolysosomal pathway, Rab29 and VPS35, which may serve as master regulators of LRRK2 kinase activity. Investigating the function and regulation of LRRK2 in the endolysosomal pathway in diverse PD models, especially in vivo models, will provide critical insight into the cellular and molecular pathophysiological mechanisms driving PD and whether LRRK2 represents a viable drug target for disease-modification in familial and sporadic PD.

scholarly journals LRRK2 phosphorylates moesin at threonine-558: characterization of how Parkinson's disease mutants affect kinase activity

2007 ◽  
Vol 405 (2) ◽  
pp. 307-317 ◽  
Author(s):  
Mahaboobi Jaleel ◽  
R. Jeremy Nichols ◽  
Maria Deak ◽  
David G. Campbell ◽  
Frank Gillardon ◽  
...  
Keyword(s):  
Parkinson’S Disease ◽  
Parkinson's Disease ◽  
Kinase Activity ◽  
Late Onset ◽  
Phosphorylation Site ◽  
Kinase Domain ◽  
Kinase Substrate ◽  
Lrrk2 Kinase ◽  
Lrrk2 Kinase Activity

Mutations in the LRRK2 (leucine-rich repeat kinase-2) gene cause late-onset PD (Parkinson's disease). LRRK2 contains leucine-rich repeats, a GTPase domain, a COR [C-terminal of Roc (Ras of complex)] domain, a kinase and a WD40 (Trp-Asp 40) motif. Little is known about how LRRK2 is regulated, what its physiological substrates are or how mutations affect LRRK2 function. Thus far LRRK2 activity has only been assessed by autophosphorylation and phosphorylation of MBP (myelin basic protein), which is catalysed rather slowly. We undertook a KESTREL (kinase substrate tracking and elucidation) screen in rat brain extracts to identify proteins that were phosphorylated by an activated PD mutant of LRRK2 (G2019S). This led to the discovery that moesin, a protein which anchors the actin cytoskeleton to the plasma membrane, is efficiently phosphorylated by LRRK2, at Thr558, a previously identified in-vivo-phosphorylation site that regulates the ability of moesin to bind actin. LRRK2 also phosphorylated ezrin and radixin, which are related to moesin, at the residue equivalent to Thr558, as well as a peptide (LRRKtide: RLGRDKYKTLRQIRQ) encompassing Thr558. We exploited these findings to determine how nine previously reported PD mutations of LRRK2 affected kinase activity. Only one of the mutations analysed, namely G2019S, stimulated kinase activity. Four mutations inhibited LRRK2 kinase activity (R1941H, I2012T, I2020T and G2385R), whereas the remainder (R1441C, R1441G, Y1699C and T2356I) did not influence activity. Therefore the manner in which LRRK2 mutations induce PD is more complex than previously imagined and is not only caused by an increase in LRRK2 kinase activity. Finally, we show that the minimum catalytically active fragment of LRRK2 requires an intact GTPase, COR and kinase domain, as well as a WD40 motif and a C-terminal tail. The results of the present study suggest that moesin, ezrin and radixin may be LRRK2 substrates, findings that have been exploited to develop the first robust quantitative assay to measure LRRK2 kinase activity.

scholarly journals Functional analyses of two novel LRRK2 pathogenic variants in familial Parkinson’s disease

2021 ◽  
Author(s):  
I Coku ◽  
E Mutez ◽  
S Eddarkaoui ◽  
S Carrier ◽  
A Marchand ◽  
...  
Keyword(s):  
Parkinson’S Disease ◽  
Parkinson's Disease ◽  
Kinase Activity ◽  
Kinase Inhibitor ◽  
Functional Testing ◽  
Pathogenic Variants ◽  
Lrrk2 Kinase ◽  
Functional Analyses ◽  
Familial Parkinson’S Disease ◽  
Inhibitor Treatment

ABSTRACTBackgroundPathogenic variants in the LRRK2 gene are a common monogenic cause of Parkinson’s disease. However, only seven variants have been confirmed to be pathogenic.ObjectivesWe identified two novel LRRK2 variants (H230R and A1440P) and performed functional testing.MethodsWe transiently expressed wildtype, the two new variants, or two known pathogenic mutants (G2019S and R1441G), in HEK-293T cells, with or without LRRK2 kinase inhibitor treatment. We characterized the phosphorylation and kinase activity of the mutants by western blotting. Thermal shift assays were performed to determine the folding and stability of the LRRK2 proteins.ResultsThe two variants were found in two large families and segregate with the disease. They display altered LRRK2 phosphorylation and kinase activity.ConclusionsWe identified two novel LRRK2 variants which segregate with the disease. The results of functional testing lead us to propose these two variants as novel causative mutations for familial Parkinson’s disease.

scholarly journals Pharmacological rescue of impaired mitophagy in Parkinson’s disease-related LRRK2 G2019S knock-in mice

eLife ◽  
2021 ◽  
Vol 10 ◽  
Author(s):  
Francois Singh ◽  
Alan R Prescott ◽  
Philippa Rosewell ◽  
Graeme Ball ◽  
Alastair D Reith ◽  
...  
Keyword(s):  
Parkinson’S Disease ◽  
Parkinson's Disease ◽  
Kinase Inhibitors ◽  
Kinase Inhibitor ◽  
Neurodegenerative Disorder ◽  
Reporter Mice ◽  
Lrrk2 G2019s ◽  
Lrrk2 Kinase

Parkinson’s disease (PD) is a major and progressive neurodegenerative disorder, yet the biological mechanisms involved in its aetiology are poorly understood. Evidence links this disorder with mitochondrial dysfunction and/or impaired lysosomal degradation – key features of the autophagy of mitochondria, known as mitophagy. Here, we investigated the role of LRRK2, a protein kinase frequently mutated in PD, in this process in vivo. Using mitophagy and autophagy reporter mice, bearing either knockout of LRRK2 or expressing the pathogenic kinase-activating G2019S LRRK2 mutation, we found that basal mitophagy was specifically altered in clinically relevant cells and tissues. Our data show that basal mitophagy inversely correlates with LRRK2 kinase activity in vivo. In support of this, use of distinct LRRK2 kinase inhibitors in cells increased basal mitophagy, and a CNS penetrant LRRK2 kinase inhibitor, GSK3357679A, rescued the mitophagy defects observed in LRRK2 G2019S mice. This study provides the first in vivo evidence that pathogenic LRRK2 directly impairs basal mitophagy, a process with strong links to idiopathic Parkinson’s disease, and demonstrates that pharmacological inhibition of LRRK2 is a rational mitophagy-rescue approach and potential PD therapy.

scholarly journals Vitamin B12 modulates Parkinson’s disease LRRK2 kinase activity through allosteric regulation and confers neuroprotection

Cell Research ◽  
2019 ◽  
Vol 29 (4) ◽  
pp. 313-329 ◽  
Author(s):  
Adam Schaffner ◽  
Xianting Li ◽  
Yacob Gomez-Llorente ◽  
Emmanouela Leandrou ◽  
Anna Memou ◽  
...  
Keyword(s):  
Parkinson’S Disease ◽  
Parkinson's Disease ◽  
Vitamin B12 ◽  
Kinase Activity ◽  
Allosteric Regulation ◽  
Lrrk2 Kinase ◽  
Lrrk2 Kinase Activity

scholarly journals Combined knockout of Lrrk2 and Rab29 does not result in behavioral abnormalities in vivo

2020 ◽  
Author(s):  
Melissa Conti Mazza ◽  
Victoria Nguyen ◽  
Alexandra Beilina ◽  
Jinhui Ding ◽  
Mark R. Cookson
Keyword(s):  
Parkinson’S Disease ◽  
Parkinson's Disease ◽  
Kinase Activity ◽  
Association Studies ◽  
Dopamine Neurons ◽  
Substantia Nigra Pars Compacta ◽  
Genome Wide Association Studies ◽  
Double Knockout ◽  
Knockout Mouse Model

AbstractCoding mutations in the LRRK2 gene, encoding for a large protein kinase, have been shown to cause familial Parkinson’s disease (PD). The immediate biological consequence of LRRK2 mutations is to increase kinase activity, leading to the suggestion that inhibition of this enzyme might be useful therapeutically to slow disease progression. Genome-wide association studies have identified the chromosomal loci around LRRK2 and one of its proposed substrates, RAB29, as contributors towards the lifetime risk of sporadic PD. Considering the evidence for interactions between LRRK2 and RAB29 on the genetic and protein levels, here we generated a double knockout mouse model and determined whether there are any consequences on brain function with aging. From a battery of motor and non-motor behavioral tests, we noted only that 18-24 month Rab29-/- and double (Lrrk2-/-/Rab29-/-) knockout mice had diminished locomotor behavior in open field compared to wildtype mice. However, no genotype differences were seen in number of substantia nigra pars compacta (SNc) dopamine neurons or in tyrosine hydroxylase levels in the SNc and striatum, which might reflect a PD-like pathology. These results suggest that depletion of both Lrrk2 and Rab29 is tolerated, at least in mice, and support that this pathway might be able to be safely targeted for therapeutics in humans.Significance statementGenetic variation in LRRK2 that result in elevated kinase activity can cause Parkinson’s disease (PD), suggesting LRRK2 inhibition as a therapeutic strategy. RAB29, a substrate of LRRK2, has also been associated with increased PD risk. Evidence exists for an interactive relationship between LRRK2 and RAB29. Mouse models lacking either LRRK2 or RAB29 do not show brain pathologies. We hypothesized that the loss of both targets would result in additive effects across in vivo and post-mortem assessments in aging mice. We found that loss of both LRRK2 and RAB29 did not result in significant behavioral deficits or dopamine neuron loss. This evidence suggests that chronic inhibition of this pathway should be tolerated clinically.

scholarly journals p38-TFEB pathways promote microglia activation through inhibiting CMA-mediated NLRP3 degradation in Parkinson's disease

2021 ◽  
Vol 18 (1) ◽  
Author(s):  
Jialong Chen ◽  
Kanmin Mao ◽  
Honglin Yu ◽  
Yue Wen ◽  
Hua She ◽  
...  
Keyword(s):  
Parkinson’S Disease ◽  
Parkinson's Disease ◽  
Nlrp3 Inflammasome ◽  
Dopaminergic Neurons ◽  
Microglia Activation ◽  
Microglial Cells ◽  
Substantia Nigra Pars Compacta ◽  
Mice Model ◽  
Chaperone Mediated Autophagy

Abstract Background Parkinson’s disease (PD) is characterized by degeneration of dopaminergic neurons in the substantia nigra pars compacta (SNpc), accompanied by accumulation of α-synuclein, chronic neuroinflammation and autophagy dysfunction. Previous studies suggested that misfolded α-synuclein induces the inflammatory response and autophagy dysfunction in microglial cells. The NLRP3 inflammasome signaling pathway plays a crucial role in the neuroinflammatory process in the central nervous system. However, the relationship between autophagy deficiency and NLRP3 activation induced by α-synuclein accumulation is not well understood. Methods Through immunoblotting, immunocytochemistry, immunofluorescence, flow cytometry, ELISA and behavioral tests, we investigated the role of p38-TFEB-NLRP3 signaling pathways on neuroinflammation in the α-synuclein A53T PD models. Results Our results showed that increased protein levels of NLRP3, ASC, and caspase-1 in the α-synuclein A53T PD models. P38 is activated by overexpression of α-synuclein A53T mutant, which inhibited the master transcriptional activator of autophagy TFEB. And we found that NLRP3 was degraded by chaperone-mediated autophagy (CMA) in microglial cells. Furthermore, p38-TFEB pathways inhibited CMA-mediated NLRP3 degradation in Parkinson's disease. Inhibition of p38 had a protective effect on Parkinson's disease model via suppressing the activation of NLRP3 inflammasome pathway. Moreover, both p38 inhibitor SB203580 and NLRP3 inhibitor MCC950 not only prevented neurodegeneration in vivo, but also alleviated movement impairment in α-synuclein A53T-tg mice model of Parkinson’s disease. Conclusion Our research reveals p38-TFEB pathways promote microglia activation through inhibiting CMA-mediated NLRP3 degradation in Parkinson's disease, which could be a potential therapeutic strategy for PD. Graphical abstract p38-TFEB pathways promote microglia activation through inhibiting CMA-mediated NLRP3 degradation in Parkinson's disease. In this model, p38 activates NLRP3 inflammasome via inhibiting TFEB in microglia. TFEB signaling negatively regulates NLRP3 inflammasome through increasing LAMP2A expression, which binds to NLRP3 and promotes its degradation via chaperone-mediated autophagy (CMA). NLRP3-mediated microglial activation promotes the death of dopaminergic neurons.

scholarly journals The activities of LRRK2 and GCase are positively correlated in clinical biospecimens and experimental models of Parkinson’s disease

2021 ◽  
Author(s):  
Maria Kedariti ◽  
Emanuele Frattini ◽  
Pascale Baden ◽  
Susanna Cogo ◽  
Laura Civiero ◽  
...  
Keyword(s):  
Parkinson’S Disease ◽  
Parkinson's Disease ◽  
Kinase Activity ◽  
Experimental Models ◽  
Cellular Functions ◽  
Gene Encoding ◽  
Cellular Models ◽  
Lrrk2 Kinase ◽  
The Impact ◽  
Lrrk2 Kinase Activity

AbstractLRRK2 is a kinase involved in different cellular functions, including autophagy, endolysosomal pathways and vesicle trafficking. Mutations in LRRK2 cause autosomal dominant forms of Parkinson’s disease (PD). Heterozygous mutations in GBA1, the gene encoding the lysosomal enzyme glucocerebrosidase (GCase), are the most common genetic risk factors for PD. Moreover, GCase function is altered in idiopathic PD and in other genetic forms of the disease. Recent work suggests that LRRK2 kinase activity can regulate GCase function. However, both a positive and a negative correlation have been described. To gain insights into the impact of LRRK2 on GCase, we investigated GCase levels and activity in LRRK2 G2019S knockin mice, in clinical biospecimens from PD patients carrying this mutation and in patient-derived cellular models. In these models we found a positive correlation between the activities of LRRK2 and GCase, which was further confirmed in cell lines with genetic and pharmacological manipulation of LRRK2 kinase activity. Overall, our study indicates that LRRK2 kinase activity affects both the levels and the catalytic activity of GCase.

Role of LRRK2 kinase activity in the pathogenesis of Parkinson's disease

2012 ◽  
Vol 40 (5) ◽  
pp. 1058-1062 ◽  
Author(s):  
Elisa Greggio
Keyword(s):  
Parkinson’S Disease ◽  
Parkinson's Disease ◽  
Kinase Activity ◽  
Complex Molecule ◽  
Disease Onset ◽  
Missense Mutations ◽  
Lrrk2 Kinase ◽  
Lrrk2 Kinase Activity

Interest in studying the biology of LRRK2 (leucine-rich repeat kinase 2) started in 2004 when missense mutations in the LRRK2 gene were linked to an inherited form of Parkinson's disease with clinical and pathological presentation resembling the sporadic syndrome. LRRK2 is a complex molecule containing domains implicated in protein interactions, as well as kinase and GTPase activities. The observation that the common G2019S mutation increases kinase activity in vitro suggests that altered phosphorylation of LRRK2 targets may have pathological outcomes. Given that protein kinases are ideal targets for drug therapies, much effort has been directed at understanding the role of LRRK2 kinase activity on disease onset. However, no clear physiological substrates have been identified to date, indicating that much research is still needed to fully understand the signalling pathways orchestrated by LRRK2 and deregulated under pathological conditions.

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