The Michael J. Fox Foundation's Strategies for Accelerating Translation of LRRK2 into Therapies for Parkinson Disease

Exploring public perceptions and awareness of Parkinson's disease: A scoping review

BACKGROUND

Parkinson's disease (PD) is a common neurological disease affecting around 1% of people above sixty years old. It is characterised by both motor and non-motor symptoms including tremor, slow movement, unsteady gait, constipation and urinary incontinence. As the disease progresses, individuals living with the disease are likely to lose their independence and autonomy, subsequently affecting their quality of life. People with PD should be supported to live well within their communities but there has been limited research regarding what the public know about PD. This review aims to develop an understanding of how the public view people living with PD, which has the potential to aid the development of an educational resource for the future to improve public awareness and understanding of PD. The purpose of this scoping review is to review and synthesise the literature on the public perception and attitudes towards people living with PD and identify and describe key findings.

AIM

This scoping review aims to explore public perceptions and awareness of Parkinson's Disease among diverse populations, encompassing beliefs, knowledge, attitudes, and the broader societal context influencing these perceptions.

METHODS

A scoping review of the literature was conducted following the Preferred Reporting Items for Systematic Reviews and Meta-analysis extension for ScR (PRISMA-ScR). Four electronic databases were searched systematically (CINAHL Plus, Medline, PsycINFO and International Bibliography of the Social Sciences). The Joanna Briggs Institute Critical Appraisal Tools (JBI) were used to assess the quality of primary studies, however, all relevant studies were considered regardless of their methodological quality. The 'Population-Concept-Context' framework was used in the screening process to identify eligible papers.

RESULTS

A total of 23 studies were included in the review representing global research in quantitative (n = 12) and mixed methods approaches (n = 11). All 23 studies adopted some aspect of cross-sectional design. Three themes emerged from the studies, the first being public knowledge of symptoms, causes and treatment of PD and this highlighted a lack of understanding about the disease. Secondly, the review identified public attitudes towards PD, highlighting the social consequences of the disease, including the association between PD and depression, isolation and loss of independence. Finally, the third theme highlighted that there was a paucity of educational resources available to help increase public understanding of PD.

CONCLUSION

Findings from this scoping review have indicated that public awareness of PD is a growing area of interest. To our knowledge, this is the first scoping review on this topic and review findings have indicated that public knowledge and attitudes towards PD vary internationally. The implications of this are that people with PD are more likely to be a marginalised group within their communities. Future research should focus on understanding the perception of the public from the perspective of people with PD, the development of interventions and awareness campaigns to promote public knowledge and attitude and further high-quality research to gauge public perceptions of PD.

A blood-based marker of mitochondrial DNA damage in Parkinson's disease

Parkinson's disease (PD) is the most common neurodegenerative movement disorder, and neuroprotective or disease-modifying interventions remain elusive. High-throughput markers aimed at stratifying patients on the basis of shared etiology are required to ensure the success of disease-modifying therapies in clinical trials. Mitochondrial dysfunction plays a prominent role in the pathogenesis of PD. Previously, we found brain region-specific accumulation of mitochondrial DNA (mtDNA) damage in PD neuronal culture and animal models, as well as in human PD postmortem brain tissue. To investigate mtDNA damage as a potential blood-based marker for PD, we describe herein a PCR-based assay (Mito DNADX) that allows for the accurate real-time quantification of mtDNA damage in a scalable platform. We found that mtDNA damage was increased in peripheral blood mononuclear cells derived from patients with idiopathic PD and those harboring the PD-associated leucine-rich repeat kinase 2 (LRRK2) G2019S mutation in comparison with age-matched controls. In addition, mtDNA damage was elevated in non-disease-manifesting LRRK2 mutation carriers, demonstrating that mtDNA damage can occur irrespective of a PD diagnosis. We further established that Lrrk2 G2019S knock-in mice displayed increased mtDNA damage, whereas Lrrk2 knockout mice showed fewer mtDNA lesions in the ventral midbrain, compared with wild-type control mice. Furthermore, a small-molecule kinase inhibitor of LRRK2 mitigated mtDNA damage in a rotenone PD rat midbrain neuron model and in idiopathic PD patient-derived lymphoblastoid cell lines. Quantifying mtDNA damage using the Mito DNADX assay may have utility as a candidate marker of PD and for measuring the pharmacodynamic response to LRRK2 kinase inhibitors.

Celebrities and Medical Awareness-The Case of Celine Dion and Stiff-Person Syndrome

The positive role of celebrities in spreading important medical information and contributing to increasing public awareness regarding the diagnosis, treatment, and prevention of various medical conditions cannot be overemphasized. Interestingly and importantly at the same time, this impact is not related to the rarity of the disease, as very rare diseases are looked up by the public due to the fact that a celebrity suffers from this disorder. Therefore, if taken seriously and used to address the public in regard to critical medical conditions, such as screening for cancer or the importance of vaccines in fighting infections, celebrities could have a huge impact in this field. As previously shown in the medical literature, the recent announcement of the famous Canadian singer Celine Dion concerning her newly diagnosed stiff-person syndrome has influenced the public interest regarding the syndrome which manifested as an increased search volume related to the disorder as seen in Google Trends. In brief, in this short communication we aimed to address the phenomenon of celebrities' impact on public apprehension, revise the syndrome for the medical community, and emphasize taking advantage of such involvement of celebrities for improving the spread of highly important medical information for the public.

Abrogation of LRRK2 dependent Rab10 phosphorylation with TLR4 activation and alterations in evoked cytokine release in immune cells

LRRK2 protein is expressed prominently in immune cells, cell types whose contribution to LRRK2-associated genetic Parkinson's disease (PD) is increasingly being recognised. We investigated the effect of inflammatory stimuli using RAW264.7 murine macrophage cells as model systems. A detailed time course of TLR2 and TLR4 stimulation was investigated through measuring LRRK2 phosphorylation at its specific phospho-sites, and Rab8 and Rab10 phosphorylation together with cytokine release following treatment with LPS and zymosan. LRRK2 phosphorylation at Ser935, Ser955 and Ser973 was increased significantly over untreated conditions at 4-24h in both WT-LRRK2 and T1348N-LRRK2 cell lines to similar extents although levels of Ser910 phosphorylation were maintained at higher levels throughout. Importantly we demonstrate that LPS stimulation significantly decreased phospho-Rab10 but not phospho-Rab8 levels over 4-24h in both WT-LRRK2 and T1348N-LRRK2 cell lines. The dephosphorylation of Rab10 was not attributed to its specific phosphatase, PPM1H as the levels remained unaltered with LPS treatment. MAPK phosphorylation occurred prior to LRRK2 phosphorylation which was validated by blocking TLR4 and TLR2 receptors with TAK242 or Sparstolonin B respectively. A significant decrease in basal level of TNFα release was noted in both T1348N-LRRK2 and KO-LRRK2 cell lines at 48h compared to WT-LRRK2 cell line, however LPS and zymosan treatment did not cause any significant alteration in the TNFα and IL-6 release between the three cell lines. In contrast, LPS and zymosan caused significantly lower IL-10 release in T1348N-LRRK2 and KO-LRRK2 cell lines. A significant decrease in phospho-Rab10 levels was also confirmed in human IPS-derived macrophages with TLR4 activation. Our data demonstrates for the first time that LRRK2-dependent Rab10 phosphorylation is modulated by LPS stimulation, and that cytokine release may be influenced by the status of LRRK2. These data provide further insights into the function of LRRK2 in immune response, and has relevance for understanding cellular dysfunctions when developing LRRK2-based inhibitors for clinical treatment.

Genetic background influences LRRK2-mediated Rab phosphorylation in the rat brain

Pathogenic missense mutations in the leucine-rich repeat kinase 2 gene, encoding LRRK2, results in the upregulation of Rab10 and Rab12 phosphorylation in different cells and tissues. Here, we evaluate levels of the LRRK2 kinase substrates pT73-Rab10 and pS106-Rab12 proteins in rat brain tissues from different genetic backgrounds. Whereas lines of Sprague Dawley rats have equivalent levels of pT73-Rab10 and pS106-Rab12 similar to Lrrk2 knockout rats, Long-Evans rats have levels of pT73-Rab10 and pS106-Rab12 comparable to G2019S-LRRK2 BAC transgenic rats. Strong LRRK2 kinase inhibitors are ineffective at reducing pT73-Rab10 and pS106-Rab12 levels in the Sprague Dawley rats, but potently reduce pT73-Rab10 and pS106-Rab12 levels in Long-Evans rats. Oral administration of the PFE-360 LRRK2 kinase inhibitor fails to provide neuroprotection from dopaminergic neurodegeneration caused by rAAV2/1-mediated overexpression of A53T-αsynuclein in Sprague Dawley rats. These results highlight substantial differences in LRRK2-mediated Rab10 and Rab12 phosphorylation in commonly utilized rat genetic backgrounds and suggest LRRK2 may not play a central role in Rab phosphorylation or mutant αsynuclein toxicity in Sprague Dawley rats.