1
|
Abstract
Two fluorescence resonance energy transfer (FRET)-based biosensor cell lines developed several years ago by the Diamond group (University of Texas, Southwestern) have allowed convenient, sensitive, and specific measurement of the intracellular aggregation of tau and α-synuclein following the addition of oligomer or small-aggregate "seeds" of these proteins from various sources, and an advancement relative to similar single-fluorophore systems. These biosensor cell lines allow researchers to both visualize the intracellular aggregates of tau or α-synuclein and measure intracellular aggregation with high sensitivity using a FRET signal in flow cytometry. Here we provide detailed protocols for generating seeds, culturing the biosensor cells, measuring intracellular aggregates by flow cytometry, and analyzing the results and discuss the utility of the technique with the aim of characterizing factors involved in the regulation of intracellular tau and α-synuclein aggregation.
Collapse
Affiliation(s)
- Katherine N Maina
- Department of Neurology, David Geffen School of Medicine, University of California, Los Angeles, CA, USA
| | - Caroline Smet-Nocca
- Université de Lille, Inserm, CHU Lille, Institut Pasteur de Lille, U1167 - RID-AGE - Risk Factors and Molecular Determinants of Aging-Related Diseases, Lille, France
- CNRS EMR9002 Integrative Structural Biology, Lille, France
| | - Gal Bitan
- Department of Neurology, David Geffen School of Medicine, University of California, Los Angeles, CA, USA.
- Brain Research Institute, University of California, Los Angeles, CA, USA.
- Molecular Biology Institute, University of California, Los Angeles, CA, USA.
| |
Collapse
|
2
|
Palma JA, Martinez J, Millar Vernetti P, Ma T, Perez MA, Zhong J, Qian Y, Dutta S, Maina KN, Siddique I, Bitan G, Ades-Aron B, Shepherd TM, Kang UJ, Kaufmann H. mTOR Inhibition with Sirolimus in Multiple System Atrophy: A Randomized, Double-Blind, Placebo-Controlled Futility Trial and 1-Year Biomarker Longitudinal Analysis. Mov Disord 2022; 37:778-789. [PMID: 35040506 PMCID: PMC9018525 DOI: 10.1002/mds.28923] [Citation(s) in RCA: 13] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/26/2021] [Revised: 12/01/2021] [Accepted: 12/27/2021] [Indexed: 12/20/2022] Open
Abstract
BACKGROUND Multiple system atrophy (MSA) is a fatal neurodegenerative disease characterized by the aggregation of α-synuclein in glia and neurons. Sirolimus (rapamycin) is an mTOR inhibitor that promotes α-synuclein autophagy and reduces its associated neurotoxicity in preclinical models. OBJECTIVE To investigate the efficacy and safety of sirolimus in patients with MSA using a futility design. We also analyzed 1-year biomarker trajectories in the trial participants. METHODS Randomized, double-blind, parallel group, placebo-controlled clinical trial at the New York University of patients with probable MSA randomly assigned (3:1) to sirolimus (2-6 mg daily) for 48 weeks or placebo. Primary endpoint was change in the Unified MSA Rating Scale (UMSARS) total score from baseline to 48 weeks. (ClinicalTrials.gov NCT03589976). RESULTS The trial was stopped after a pre-planned interim analysis met futility criteria. Between August 15, 2018 and November 15, 2020, 54 participants were screened, and 47 enrolled and randomly assigned (35 sirolimus, 12 placebo). Of those randomized, 34 were included in the intention-to-treat analysis. There was no difference in change from baseline to week 48 between the sirolimus and placebo in UMSARS total score (mean difference, 2.66; 95% CI, -7.35-6.91; P = 0.648). There was no difference in UMSARS-1 and UMSARS-2 scores either. UMSARS scores changes were similar to those reported in natural history studies. Neuroimaging and blood biomarker results were similar in the sirolimus and placebo groups. Adverse events were more frequent with sirolimus. Analysis of 1-year biomarker trajectories in all participants showed that increases in blood neurofilament light chain (NfL) and reductions in whole brain volume correlated best with UMSARS progression. CONCLUSIONS Sirolimus for 48 weeks was futile to slow the progression of MSA and had no effect on biomarkers compared to placebo. One-year change in blood NfL and whole brain atrophy are promising biomarkers of disease progression for future clinical trials. © 2022 International Parkinson and Movement Disorder Society.
Collapse
Affiliation(s)
- Jose-Alberto Palma
- Department of Neurology, New York University Grossman School of Medicine, New York, NY, USA
| | - Jose Martinez
- Department of Neurology, New York University Grossman School of Medicine, New York, NY, USA
| | | | - Thong Ma
- Department of Neurology, New York University Grossman School of Medicine, New York, NY, USA
| | - Miguel A. Perez
- Department of Neurology, New York University Grossman School of Medicine, New York, NY, USA
| | - Judy Zhong
- Department of Population Health, Division of Biostatistics, New York University Grossman School of Medicine, New York, NY, USA
| | - Yingzhi Qian
- Department of Population Health, Division of Biostatistics, New York University Grossman School of Medicine, New York, NY, USA
| | - Suman Dutta
- Department of Neurology, David Geffen School of Medicine, University of California Los Angeles, Los Angeles, CA, USA
| | - Katherine N. Maina
- Department of Neurology, David Geffen School of Medicine, University of California Los Angeles, Los Angeles, CA, USA
| | - Ibrar Siddique
- Department of Neurology, David Geffen School of Medicine, University of California Los Angeles, Los Angeles, CA, USA
| | - Gal Bitan
- Department of Neurology, David Geffen School of Medicine, University of California Los Angeles, Los Angeles, CA, USA,Brain Research Institute, University of California, Los Angeles, CA, USA,Molecular Biology Institute, University of California, Los Angeles, CA, USA
| | - Benjamin Ades-Aron
- Department of Radiology, New York University Grossman School of Medicine, New York, NY, USA
| | - Timothy M. Shepherd
- Department of Radiology, New York University Grossman School of Medicine, New York, NY, USA
| | - Un Jung Kang
- Department of Neurology, New York University Grossman School of Medicine, New York, NY, USA
| | - Horacio Kaufmann
- Department of Neurology, New York University Grossman School of Medicine, New York, NY, USA
| |
Collapse
|