DARP-36aa selectively promotes survival and morphological development of cultured mesencephalic neurons.
We examined the effects of DARP-36aa on the survival and morphological development of embryonic rat mesencephalic neurons. Treatment of mesencephalic cultures with DARP-36aa, a synthetic peptide corresponding to the N terminal of dopamine-releasing protein (DARP), resulted in a 1.8-fold increase in neuron survival. Morphological analysis revealed that DARP-36aa-treated neurons contained 48% more branching points per neuron compared with controls. DARP-36aa selectively affected mesencephalic cultures; diencephalic and C6 glioma cells were not affected by DARP-36aa treatments. Mesencephalic cultures were also incubated with polyclonal antibodies against DARP-36aa (anti-DARP-36aa) to assess the effect of immunoneutralization of endogenous DARP on these cells. Mesencephalic cultures treated with anti-DARP-36aa contained 43% fewer neurons, and the number of branching points per neuron was decreased by nearly twofold compared with cultures grown with medium alone. Similar to cultures treated with DARP-36aa, immunoneutralization of DARP had no effect on any parameters examined in primary diencephalic and C6 glioma cultures. Mesencephalic cultures maintained in the presence of DARP-36aa had a 3.2-fold increase in the number of tyrosine hydroxylase (TH)-immunoreactive neurons, whereas anti-DARP-36aa incubations decreased TH-immunoreactive neurons by 40% compared with control cultures. Finally, coincubation of the specific tyrosine kinase inhibitor genistein with DARP-36aa resulted in a complete attenuation of DARP-36aa-mediated neuron survival and development in mesencephalic cultures. The findings indicate that DARP-36aa is a novel neurotrophic peptide that selectively promotes the survival and development of mesencephalic neurons.
Smith
Sean M
SM
Neuroscience Program, Department of Molecular and Integrative Physiology, University of Illinois at Urbana-Champaign, Urbana, Illinois 61801, USA.
Ramirez
Victor D
VD
D000595:Amino Acid Sequence; D000818:Animals; D000906:Antibodies / Q000494:pharmacology; D002395:Catecholamines / Q000378:metabolism; D002452:Cell Count; D002470:Cell Survival; D002478:Cells, Cultured; D004027:Diencephalon / Q000166:cytology / Q000196:embryology; D004791:Enzyme Inhibitors / Q000494:pharmacology; D019833:Genistein / Q000494:pharmacology; D006023:Glycoproteins / Q000737:chemistry; D036341:Intercellular Signaling Peptides and Proteins; D008636:Mesencephalon / Q000166:cytology* / Q000196:embryology*; D008969:Molecular Sequence Data; D009419:Nerve Tissue Proteins / Q000737:chemistry / Q000276:immunology / Q000494:pharmacology*; D009474:Neurons / Q000166:cytology* / Q000187:drug effects; D010446:Peptide Fragments / Q000737:chemistry / Q000276:immunology / Q000494:pharmacology*; D051381:Rats; D017207:Rats, Sprague-Dawley; D014407:Tumor Cells, Cultured; D014446:Tyrosine 3-Monooxygenase / Q000032:analysis
D000906:Antibodies; D002395:Catecholamines; C470467:DARP-36aa; D004791:Enzyme Inhibitors; D006023:Glycoproteins; D036341:Intercellular Signaling Peptides and Proteins; D009419:Nerve Tissue Proteins; D010446:Peptide Fragments; C058043:dopamine-releasing factor, rat; D019833:Genistein; D014446:Tyrosine 3-Monooxygenase