Administration of AAV-Alpha Synuclein NAC Antibody Improves Locomotor Behavior in Rats Overexpressing Alpha Synuclein.

Yun Wang,Yun-Hsiang Chen,Brandon K Harvey,Seong-Jin Yu,Wei Hsieh,Kuo-Jen Wu,Barry J Hoffer

doi:10.3390/genes12060948

Abstract

Accumulation of α-Synuclein (αSyn) in nigral dopaminergic neurons is commonly seen in patients with Parkinson′s disease (PD). We recently reported that transduction of intracellular single-chain intrabody targeting the 53–87 amino acid residues of human αSyn by recombinant adeno associated viral vector (AAV-NAC32) downregulated αSyn protein in SH-SY5Y cells and rat brain. This study characterizes the behavioral phenotype and dopaminergic protection in animals receiving AAV-NAC32. Our results show that adult DAT-Cre rats selectively overexpress αSyn in nigra dopaminergic neurons after local administration of AAV-DIO-αSyn. These animals develop PD-like phenotype, including bradykinesia and loss of tyrosine hydroxylase (TH) immunoreactivity in substantia nigra pars compacta dorsal tier (SNcd). An injection of AAV-NAC32 to nigra produces a selective antibody against αSyn and normalizes the behavior. AAV-NAC32 significantly increases TH, while reduces αSyn immunoreactivity in SNcd. Altogether, our data suggest that an AAV-mediated gene transfer of NAC32 antibody effectively antagonizes αSyn-mediated dopaminergic degeneration in nigra, which may be a promising therapeutic candidate for synucleinopathy or PD.

Highlights

We demonstrated that the antibody targeting the 53–87 amino acid residues of human αSyn (NAC32) profoundly downregulated αSyn protein, but not αSyn mRNA levels in these cells
adenoassociated virus (AAV)-DIOCultured CHO cells were transduced with recombinant
Injection of AAV-NAC32 produced a selective antibody against the nonamyloidal component (NAC) in imals developed Parkinson’s disease (PD)-like phenotype, including bradykinesia and loss of dopaminergic αSyn, normalized the behavior, and increased the survival of nigra dopaminergic cells

Summary

Introduction

The major histopathology in PD is the formation of fibrillar aggregate or Lewy bodies in nigra. Α-Synuclein (αSyn), a 140 amino acid protein, is the primary component in the Lewy body and has been reported genetically linked to familial PD [1]. Two other proteins in the same synuclein family are βSyn (134 amino acids) and γSyn (127 amino acids). ΒSyn and γSyn share high sequence homology with αSyn. Two other proteins in the same synuclein family are βSyn (134 amino acids) and γSyn (127 amino acids). ΒSyn and γSyn share high sequence homology with αSyn These synucleins, are not found in the Lewy body and are less involved in the pathology of PD. The major structural difference between αSyn and βSyn is in the NAC region. The major structural difference between αSyn and βSyn is in the NAC region. βSyn is missing an 11-residue stretch (73–84) in the NAC and is more resistant to aggregation [6]

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