A synthetic five amino acid propeptide increases dopamine neuron differentiation and neurochemical function

O. M. Littrell, J. L. Fuqua, A. D. Richardson, J. Turchan-Cholewo, E. R. Hascup, P. Huettl, F. Pomerleau, L. H. Bradley, D. M. Gash, G. A. Gerhardt

Research output: Contribution to journalArticlepeer-review

1 Scopus citations


A major consequence of Parkinson's disease (PD) involves the loss of dopaminergic neurons in the substantia nigra (SN) and a subsequent loss of dopamine (DA) in the striatum. We have shown that glial cell line-derived neurotrophic factor (GDNF) shows robust restorative and protective effects for DA neurons in rats, non-human primates and possibly in humans. Despite GDNF's therapeutic potential, its clinical value has been questioned due to its limited diffusion to target areas from its large size and chemical structure. Several comparatively smaller peptides are thought to be generated from the prosequence. A five amino-acid peptide, dopamine neuron stimulating peptide-5 (DNSP-5), has been proposed to demonstrate biological activity relevant to neurodegenerative disease. We tested the in vitro effects of DNSP-5 in primary dopaminergic neurons dissected from the ventral mesencephalon of E14 Sprague Dawley rat fetuses. Cells were treated with several doses (0.03, 0.1, 1.0, 10.0. ng/mL) of GDNF, DNSP-5, or an equivalent volume of citrate buffer (vehicle). Morphological features of tyrosine hydroxylase positive neurons were quantified for each dose. DNSP-5 significantly increased (p<0.001) all differentiation parameters compared to citrate vehicle (at one or more dose). For in vivo studies, a unilateral DNSP-5 treatment (30. μg) was administered directly to the SN. Microdialysis in the ipsilateral striatum was performed 28. days after treatment to determine extracellular levels of DA and its primary metabolites (3,4-dihydroxyphenylacetic acid and homovanillic acid). A single treatment significantly increased (∼66%) extracellular DA levels compared to vehicle, while DA metabolites were unchanged. Finally, the protective effects of DNSP-5 against staurosporine-induced cytotoxicity were investigated in a neuronal cell line showing substantial protection by DNSP-5. Altogether, these studies strongly indicate biological activity of DNSP-5 and suggest that DNSP-5 has neurotrophic-like properties that may be relevant to the treatment of neurodegenerative diseases like PD.

Original languageEnglish
Pages (from-to)43-49
Number of pages7
Issue number1
StatePublished - Feb 2013

Bibliographical note

Funding Information:
GAG: NIH Training Grants: 5T32 AG000242-14, T32 DA022738 (OML/JLF); USPHS NS39787; DA017186; AG13494; NSF EEC-0310723.


  • Dopamine
  • Glial cell line-derived neurotrophic factor
  • Parkinson's disease
  • Striatum

ASJC Scopus subject areas

  • Endocrinology
  • Neurology
  • Endocrine and Autonomic Systems
  • Cellular and Molecular Neuroscience


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