BackgroundTreatment of mild-moderate Alzheimer’s disease (AD) subjects (N = 119) for 52 weeks with the SIRT1 activator resveratrol (up to 1 g by mouth twice daily) attenuates progressive declines in CSF Aβ40 levels and activities of daily living (ADL) scores.MethodsFor this retrospective study, we examined banked CSF and plasma samples from a subset of AD subjects with CSF Aβ42 <600 ng/ml (biomarker-confirmed AD) at baseline (N = 19 resveratrol-treated and N = 19 placebo-treated). We utilized multiplex Xmap technology to measure markers of neurodegenerative disease and metalloproteinases (MMPs) in parallel in CSF and plasma samples.ResultsCompared to the placebo-treated group, at 52 weeks, resveratrol markedly reduced CSF MMP9 and increased macrophage-derived chemokine (MDC), interleukin (IL)-4, and fibroblast growth factor (FGF)-2. Compared to baseline, resveratrol increased plasma MMP10 and decreased IL-12P40, IL12P70, and RANTES. In this subset analysis, resveratrol treatment attenuated declines in mini-mental status examination (MMSE) scores, change in ADL (ADCS-ADL) scores, and CSF Aβ42 levels during the 52-week trial, but did not alter tau levels.ConclusionsCollectively, these data suggest that resveratrol decreases CSF MMP9, modulates neuro-inflammation, and induces adaptive immunity. SIRT1 activation may be a viable target for treatment or prevention of neurodegenerative disorders.Trial registrationClinicalTrials.gov NCT01504854

Parkinson's disease is a movement disorder characterized by death of dopaminergic substantia nigra (SN) neurons and brain accumulation of α-synuclein. The tyrosine kinase Abl is activated in neurodegeneration. Here, we show that lentiviral expression of α-synuclein in the mouse SN leads to Abl activation (phosphorylation) and lentiviral Abl expression increases α-synuclein levels, in agreement with Abl activation in PD brains. Administration of the tyrosine kinase inhibitor nilotinib decreases Abl activity and ameliorates autophagic clearance of α-synuclein in transgenic and lentiviral gene transfer models. Subcellular fractionation shows accumulation of α-synuclein and hyper-phosphorylated Tau (p-Tau) in autophagic vacuoles in α-synuclein expressing brains, but nilotinib enhances protein deposition into the lysosomes. Nilotinib is used for adult leukemia treatment and it enters the brain within US Food and Drug Administration approved doses, leading to autophagic degradation of α-synuclein, protection of SN neurons and amelioration of motor performance. These data suggest that nilotinib may be a therapeutic strategy to degrade α-synuclein in PD and other α-synucleinopathies.

Background: We evaluated the effects of low doses of the tyrosine kinase Abelson (Abl) inhibitor Nilotinib, on safety and pharmacokinetics in Parkinson’s disease dementia or dementia with Lewy bodies.Objectives: The primary outcomes of this study were safety and tolerability; pharmacokinetics and target engagement were secondary, while clinical outcomes were exploratory.Methods: Twelve subjects were randomized into 150 mg (n = 5) or 300 mg (n = 7) groups and received Nilotinib orally every day for 24 weeks.Results: This study shows that 150 mg and 300 mg doses of Nilotinib appear to be safe and tolerated in subjects with advanced Parkinson’s disease. Nilotinib is detectable in the cerebrospinal fluid (CSF) and seems to engage the target Abl. Motor and cognitive outcomes suggest a possible beneficial effect on clinical outcomes. The CSF levels of homovanillic acid are significantly increased between baseline and 24 weeks of treatment. Exploratory CSF biomarkers were measured.Conclusions: This small proof-of-concept study lacks a placebo group and participants were not homogenous, resulting in baseline differences between and within groups. This limits the interpretations of the biomarker and clinical data, and any conclusions should be drawn cautiously. Nonetheless, the collective observations suggest that it is warranted to evaluate the safety and efficacy of Nilotinib in larger randomized, double-blind, placebo-controlled trials.

IMPORTANCE This study evaluated nilotinib safety and its effects on biomarkers as a potential disease-modifying drug in Parkinson disease.OBJECTIVES To assess nilotinib effects on safety and pharmacokinetics and measure the change in exploratory biomarkers in patients with moderately severe Parkinson disease. DESIGN, SETTING, AND PARTICIPANTSThis was a single-center, phase 2, randomized, double-blind, placebo-controlled trial with 300 patients approached in clinic; of these, 200 declined to participate, 100 were screened, 25 were excluded, and 75 were randomized 1:1:1 into placebo; nilotinib, 150-mg; or nilotinib, 300-mg groups. Recruitment started on May 17, 2017, and ended April 28, 2018, and follow-up ended August 10, 2019. Parkinson disease was confirmed according to the UK Brain Bank diagnostic criteria and symptoms were stabilized with use of optimal levodopa and/or dopamine agonists and other medications used in Parkinson disease.INTERVENTIONS Nilotinib vs placebo, administered orally once daily for 12 months followed by a 3-month washout period.MAIN OUTCOMES AND MEASURES It was hypothesized that nilotinib is safe and can be detected in the cerebrospinal fluid, where it alters exploratory biomarkers via inhibition of Abelson tyrosine kinase and potentially improves clinical outcomes. RESULTSOf the 75 patients included in the study, 55 were men (73.3%); mean (SD) age was 68.4 (8.2) years. Doses of 150 or 300 mg of nilotinib were reasonably safe, although more serious adverse events were detected in the nilotinib (150 mg: 6 [24%]; 300 mg: 12 [48%]) vs placebo (4 [16%]) groups. The 150-mg nilotinib group showed an increase in cerebrospinal fluid levels of the dopamine metabolites homovanillic acid (159.80nM; 90% CI, 7.04-312.60nM; P = .04) and 3,4-dihydroxyphenylacetic acid (4.87nM; 90% CI, 1.51-8.23nM; P = .01), and the 300-mg nilotinib group showed an increase in 3,4-dihydroxyphenylacetic acid (7.52nM; 90% CI, 2.35-12.69nM; P = .01). The nilotinib 150-mg but not the nilotinib 300-mg group demonstrated a reduction of α-synuclein oligomers (−0.04 pg/mL; 90% CI, −0.08 to 0.01 pg/mL; P = .03). A significant reduction of hyperphosphorylated tau levels was seen in the nilotinib 150-mg (−10.04 pg/mL; 90% CI, −17.41 to −2.67 pg/mL; P = .01) and nilotinib 300-mg (−12.05 pg/mL; 90% CI, −19.21 to −4.90 pg/mL; P = .01) groups.CONCLUSIONS AND RELEVANCE In this study, nilotinib appeared to be reasonably safe and detectable in the cerebrospinal fluid. Exploratory biomarkers were altered in response to nilotinib. Taken together, these data will guide the development of a phase 3 study to investigate the effects of nilotinib therapy in patients with Parkinson disease. TRIAL REGISTRATION ClinicalTrials.gov identifier: NCT02954978

Background: TDP-43 pathology and the role of E3 ubiquitin ligases are increasingly recognized in neurodegeneration. Results: Parkin ubiquitinates TDP-43 and forms a multiprotein complex with HDAC6 to sequester TDP-43 in cytosol. Conclusion: Parkin E3 ubiquitin ligase activity promotes TDP-43 inclusion formation and nuclear translocation. Significance: Parkin-TDP-43 interaction may be exploited as a therapeutic strategy in ALS/FTLD pathology.

Tyrosine kinase inhibitors (TKIs) are effective therapies for leukaemia. Alzheimer is a neurodegenerative disease characterized by accumulation of β-amyloid (plaques) and hyper-phosphorylated Tau (tangles). Here we show that AD animals have high levels of insoluble parkin and decreased parkin-Beclin-1 interaction, while peripheral administration of TKIs, including Nilotinib and Bosutinib, increases soluble parkin leading to amyloid clearance and cognitive improvement. Blocking Beclin-1 expression with shRNA or parkin deletion prevents tyrosine kinase (TK) inhibition-induced amyloid clearance, suggesting that functional parkin-Beclin-1 interaction mediates amyloid degradation. Isolation of autophagic vacuoles (AVs) in AD mouse brain shows accumulation of parkin and amyloid, consistent with previous results in AD brains, while Bosutinib and Nilotinib increase parkin-Beclin-1 interaction and result in protein deposition in the lysosome. These data suggest that decreased parkin solubility impedes parkin-Beclin-1 interaction and amyloid clearance. We identified two FDA-approved anti-cancer drugs as potential treatment for AD.Two FDA-approved tyrosine kinase inhibitor drugs, Bosutinib and Nilotinib, are shown to ameliorate Alzheimer's disease pathology in mouse models by increasing soluble parkin and leading to amyloid clearance and cognitive improvement.

Alzheimer’s disease (AD) is a neurodegenerative disorder associated with amyloid accumulation and autophagic changes. Parkin is an E3 ubiquitin ligase involved in proteasomal and autophagic clearance. We previously demonstrated decreased parkin solubility and interaction with the key autophagy enzyme Beclin-1 in AD, but tyrosine kinase inhibition restored parkin-Beclin-1 interaction. In the current studies we determined the mechanisms of Nilotinib-induced parkin-Beclin-1 interaction, which leads to amyloid clearance. Nilotinib increased endogenous parkin levels and ubiquitination, which may enhance parkin recycling via the proteasome, leading to increased activity and interaction with Beclin-1. Parkin solubility was decreased and autophagy was altered in amyloid expressing mice, suggesting that amyloid stress affects parkin stability, leading to failure of protein clearance via the lysosome. Isolation of autophagic vacuoles revealed amyloid and parkin accumulation in autophagic compartments but Nilotinib decreased insoluble parkin levels and facilitated amyloid deposition into lysosomes in wild type, but not parkin−/− mice, further underscoring an essential role for endogenous parkin in amyloid clearance. These results suggest that Nilotinib boosts the autophagic machinery, leading to increased level of endogenous parkin that undergoes ubiquitination and interacts with Beclin-1 to facilitate amyloid clearance. These data suggest that Nilotinib-mediated autophagic changes may trigger parkin response via increased protein levels, providing a therapeutic strategy to reduce Aβ and Tau in AD.

Nilotinib is a broad‐based tyrosine kinase inhibitor with the highest affinity to inhibit Abelson (c‐Abl) and discoidin domain receptors ( DDR 1/2). Preclinical evidence indicates that Nilotinib reduces the level of brain alpha‐synuclein and attenuates inflammation in models of Parkinson's disease ( PD ). We previously showed that Nilotinib penetrates the blood‐brain barrier ( BBB ) and potentially improves clinical outcomes in individuals with PD and dementia with Lewy bodies ( DLB ). We performed a physiologically based population pharmacokinetic/pharmacodynamic (pop PK / PD ) study to determine the effects of Nilotinib in a cohort of 75 PD participants. Participants were randomized (1:1:1:1:1) into five groups (n = 15) and received open‐label random single dose ( RSD ) 150:200:300:400 mg Nilotinib vs placebo. Plasma and cerebrospinal fluid ( CSF ) were collected at 1, 2, 3, and 4 hours after Nilotinib administration. The results show that Nilotinib enters the brain in a dose‐independent manner and 200 mg Nilotinib increases the level of 3,4‐Dihydroxyphenylacetic acid ( DOPAC ) and homovanillic acid ( HVA ), suggesting alteration to dopamine metabolism. Nilotinib significantly reduces plasma total alpha‐synuclein and appears to reduce CSF oligomeric: total alpha‐synuclein ratio. Furthermore, Nilotinib significantly increases the CSF level of triggering receptors on myeloid cells ( TREM )‐2, suggesting an anti‐inflammatory effect. Taken together, 200 mg Nilotinib appears to be an optimal single dose that concurrently reduces inflammation and engages surrogate disease biomarkers, including dopamine metabolism and alpha‐synuclein.