Pleiotrophin mediates the neurotrophic effect of cyclic AMP on dopaminergic neurons: analysis of suppression-subtracted cDNA libraries and confirmation in vitro

Exp Neurol. 2005 Jul;194(1):243-54. doi: 10.1016/j.expneurol.2005.02.015.


To better understand the particular vulnerability of mesencephalic dopaminergic neurons to toxins or gene mutations causing parkinsonism, we have taken advantage of a primary cell culture system in which these neurons die selectively. Antimitotic agents, such as cytosine arabinoside or cAMP, prevent the death of the neurons by arresting astrocyte proliferation. To identify factors implicated in either the death of the dopaminergic neurons or in the neuroprotective effect of cAMP, we constructed cDNA libraries enriched by subtractive hybridization and suppressive PCR in transcripts that are preferentially expressed in either control or cAMP-treated cultures. Differentially expressed transcripts were identified by hybridization of the enriched cDNAs with a commercially available cDNA expression array. The proteoglycan receptors syndecan-3 and the receptor protein tyrosine phosphatase zeta/beta were found among the transcripts preferentially expressed under control conditions, and their ligand, the cytokine pleiotrophin, was highly represented in the cDNA libraries for both conditions. Since pleiotrophin is expressed during embryonic and perinatal neural development and following lesions in the adult brain, we investigated its role in our cell culture model. Pleiotrophin was not responsible for the death of dopaminergic neurons under control conditions, or for their survival in cAMP-treated cultures. It was, however, implicated in the initial and cAMP-dependent enhancement of the differentiation of the dopaminergic neurons in our cultures. In addition, our experiments have provided evidence for a cAMP-dependent regulatory pathway leading to protease activation, and the identification of pleiotrophin as a target of this pathway.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Carrier Proteins / genetics*
  • Carrier Proteins / physiology
  • Cells, Cultured
  • Cyclic AMP / metabolism*
  • Cytokines / genetics*
  • Cytokines / physiology
  • Dopamine / metabolism
  • Drug Resistance / genetics
  • Enzyme Activation / physiology
  • Gene Expression Profiling
  • Gene Expression Regulation / physiology
  • Gene Library
  • Genetic Predisposition to Disease / genetics
  • Membrane Glycoproteins / genetics
  • Nerve Degeneration / metabolism*
  • Nerve Degeneration / pathology
  • Nerve Degeneration / physiopathology
  • Nerve Growth Factors / metabolism*
  • Nerve Tissue Proteins / genetics
  • Neurons / metabolism*
  • Neurons / pathology
  • Oligonucleotide Array Sequence Analysis
  • Parkinsonian Disorders / metabolism
  • Parkinsonian Disorders / pathology
  • Parkinsonian Disorders / physiopathology
  • Peptide Hydrolases / metabolism
  • Protein Tyrosine Phosphatases / genetics
  • Proteoglycans / genetics
  • Rats
  • Receptor-Like Protein Tyrosine Phosphatases, Class 5
  • Substantia Nigra / metabolism*
  • Substantia Nigra / pathology
  • Substantia Nigra / physiopathology
  • Syndecan-3


  • Carrier Proteins
  • Cytokines
  • Membrane Glycoproteins
  • Nerve Growth Factors
  • Nerve Tissue Proteins
  • Proteoglycans
  • Sdc3 protein, rat
  • Syndecan-3
  • pleiotrophin
  • Cyclic AMP
  • Protein Tyrosine Phosphatases
  • Ptprz1 protein, rat
  • Receptor-Like Protein Tyrosine Phosphatases, Class 5
  • Peptide Hydrolases
  • Dopamine