Original Article

Neurotherapeutics

, Volume 9, Issue 2, pp 464-476

A Novel “Molecular Tweezer” Inhibitor of α-Synuclein Neurotoxicity in Vitro and in Vivo

  • Shubhangi PrabhudesaiAffiliated withDepartment of Neurology, UCLA David Geffen School of Medicine
  • , Sharmistha SinhaAffiliated withDepartment of Neurology, UCLA David Geffen School of Medicine
  • , Aida AttarAffiliated withDepartment of Neurology, UCLA David Geffen School of Medicine
  • , Aswani KotagiriAffiliated withDepartment of Neurology, UCLA David Geffen School of Medicine
  • , Arthur G. FitzmauriceAffiliated withDepartment of Neurology, UCLA David Geffen School of Medicine
  • , Ravi LakshmananAffiliated withDepartment of Chemistry and Biochemistry, University of California at Los Angeles
  • , Magdalena I. IvanovaAffiliated withDepartment of Biological Chemistry, University of California at Los Angeles
  • , Joseph A. LooAffiliated withDepartment of Chemistry and Biochemistry, University of California at Los AngelesMolecular Biology Institute, University of California at Los Angeles
  • , Frank-Gerrit KlärnerAffiliated withDepartment of Organic Chemistry, University of Duisburg-Essen
    • , Thomas SchraderAffiliated withDepartment of Organic Chemistry, University of Duisburg-Essen
    • , Mark StahlAffiliated withDepartment of Neurology, UCLA David Geffen School of Medicine
    • , Gal BitanAffiliated withDepartment of Neurology, UCLA David Geffen School of MedicineBrain Research Institute, University of California at Los AngelesMolecular Biology Institute, University of California at Los Angeles Email author 
    • , Jeff M. BronsteinAffiliated withDepartment of Neurology, UCLA David Geffen School of MedicineBrain Research Institute, University of California at Los AngelesGreater Los Angeles Veterans Administration Medical Center Email author 

Summary

Aggregation of α-synuclein (α-syn) is implicated as being causative in the pathogenesis of Parkinson’s disease, multiple system atrophy, and dementia with Lewy bodies. Despite several therapies that improve symptoms in these disorders, none slow disease progression. Recently, a novel “molecular tweezer” (MT) termed CLR01 has been described as a potent inhibitor of assembly and toxicity of multiple amyloidogenic proteins. Here we investigated the ability of CLR01 to inhibit assembly and toxicity of α-syn. In vitro, CLR01 inhibited the assembly of α-syn into β-sheet-rich fibrils and caused disaggregation of pre-formed fibrils, as determined by thioflavin T fluorescence and electron microscopy. α-Syn toxicity was studied in cell cultures and was completely mitigated by CLR01 when α-syn was expressed endogenously or added exogenously. To determine if CLR01 was also protective in vivo, we used a novel zebrafish model of α-syn toxicity (α-syn-ZF), which expresses human, wild-type α-syn in neurons. α-Syn-ZF embryos developed severe deformities due to neuronal apoptosis and most of them died within 48 to 72 h. CLR01 added to the water significantly improved zebrafish phenotype and survival, suppressed α-syn aggregation in neurons, and reduced α-syn-induced apoptosis. α-Syn expression was found to inhibit the ubiquitin proteasome system in α-syn-ZF neurons, resulting in further accumulation of α-syn. Treatment with CLR01 almost completely mitigated the proteasome inhibition. The data suggest that CLR01 is a promising therapeutic agent for the treatment of Parkinson’s disease and other synucleinopathies.

Key Words

Parkinson’s disease zebrafish synucleinopathy amyloid neuroprotection