Funded Studies
Objective/Rationale:
Mesencephalic Astrocyte-derived Neurotrophic Factor (MANF) is currently one of the most potent factors protecting and rescuing neurons in pre-clinical models of Parkinson’s disease. We found a cell-penetrating octapeptide from MANF that protects the cultured dopaminergic neurons from apoptotic death. The small size and cell-penetrating properties makes this peptide an attractive candidate for therapy in Parkinson’s disease as it spreads in the brain better than the larger full-length MANF and gets inside the neurons.
Project Description:
We will first optimize the MANF-derived peptide in vitro to find out its minimal size, effective concentration and to exclude the adverse effects on the healthy cells. The optimized peptide will then be tested on the 6-hydroxydopamine (6-OHDA) neuroprotection model of Parkinson’s disease. The peptide or Glial Cell Line-Derived Neurotrophic Factor (GDNF) as a positive control will be injected to the striata of the models, followed by 6-OHDA injection 6 h later. 2 and 4 weeks later the amphetamine-induced rotational behavior of the models will be tested to reveal the extent of the functional damage of the dopaminergic system. At the end of the experiment, the brain sections will be stained with the tyrosine hydroxylase antibodies to reveal the extent of the histological damage of the dopaminergic system.
Relevance to Diagnosis/Treatment of Parkinson’s Disease:
As the small-size peptide spreads better in the brain parenchyma than the larger proteins, it should be more efficient than the full-length MANF protein. Also, as MANF can efficiently prevent cell death intracellularly, the cell-penetrating properties of the MANF-derived peptide could attenuate its neurotrophic efficiency.
Anticipated Outcome:
A short, lay-oriented description of what you expect to learn by carrying out the work. Approximately 75 words
We expect that the MANF-derived peptide confers significant protection against 6-OHDA-induced symptoms of Parkinson’s disease. In particular, the reduction in the amphetamine-induced rotation and in the loss of dopaminergic neurons and fibers is expected. If so, future studies include spreading of the peptide in the brain and its neurorestorative potency when applied after the 6-OHDA.
Final Outcome
We found that the peptide can be reduced up to tetrapeptide that still has potent neuroprotective and cell-penetrating properties. The tetrapeptide dose-dependently promoted survival of cultured embryonic mouse dopaminergic neurons and spontaneously penetrated the neurons, but had any obvious effect on the cultured non-neuronal cells. In the proof-of-principle in vivo neuroprotective experiment, the tetrapeptide effectively counteracted the Parkinsonian symptoms caused by 6-hydroxydopamine: it significantly reduced the amphetamine-induced rotation of the animals. The effective dose of the peptide for in vivo experiments was found.