Culture conditions affect proliferative responsiveness of olfactory ensheathing glia to neuregulins.
Olfactory ensheathing glia (OEG) have been used to improve outcome after experimental spinal cord injury and are being trialed clinically. Their rapid proliferation in vitro is essential to optimize clinical application, with neuregulins (NRG) being potential mitogens. We examined the effects of NRG-1beta, NRG-2alpha, and NRG3 on proliferation of p75-immunopurified adult OEG. OEG were grown in serum-containing medium with added bovine pituitary extract and forskolin (added mitogens) or in serum-containing medium (no added mitogens). Cultures were switched to chemically defined medium (no added mitogens or serum), NRG added and OEG proliferation assayed using BrdU. OEG grown initially with added mitogens were not responsive to added NRGs and pre-exposure to forskolin and pituitary extract increased basal proliferation rates so that OEG no longer responded to added NRG. However, NRG promoted proliferation but only if cells were initially grown in mitogen-free medium. Primary OEG express ErbB2, ErbB3, and small levels of ErbB4 receptors; functional blocking indicates that ErbB2 and ErbB3 are the main NRG receptors utilized in the presence of NRG-1beta. The long-term stimulation of OEG proliferation by initial culture conditions raises the possibility of manipulating OEG before therapeutic transplantation.
De Mello
T R
TR
Red's Spinal Cord Research Laboratory, School of Anatomy and Human Biology, The University of Western Australia, 35 Stirling Highway, Perth, WA 6009, Australia.
Busfield
S
S
Dunlop
S A
SA
Plant
G W
GW
D000818:Animals; D001798:Blood Proteins / Q000494:pharmacology; D016380:Brain Tissue Transplantation / Q000379:methods; D018929:Cell Culture Techniques; D002455:Cell Division / Q000187:drug effects / Q000502:physiology; D049109:Cell Proliferation / Q000187:drug effects*; D002478:Cells, Cultured; D003470:Culture Media / Q000737:chemistry / Q000494:pharmacology; D066246:ErbB Receptors / Q000378:metabolism; D006023:Glycoproteins / Q000378:metabolism; D047908:Intracellular Signaling Peptides and Proteins / Q000378:metabolism / Q000494:pharmacology; D009414:Nerve Growth Factors / Q000378:metabolism / Q000494:pharmacology; D020890:Neuregulin-1 / Q000378:metabolism / Q000494:pharmacology; D020880:Neuregulins / Q000378:metabolism / Q000494:pharmacology*; D009457:Neuroglia / Q000187:drug effects / Q000502:physiology*; D009830:Olfactory Bulb / Q000166:cytology / Q000187:drug effects / Q000502:physiology*; D051381:Rats; D011916:Rats, Inbred F344; D018719:Erb-b2 Receptor Tyrosine Kinases; D020893:Receptor, ErbB-3 / Q000378:metabolism; D066247:Receptor, ErbB-4
D001798:Blood Proteins; D003470:Culture Media; D066246:ErbB Receptors; D006023:Glycoproteins; D047908:Intracellular Signaling Peptides and Proteins; D009414:Nerve Growth Factors; D020890:Neuregulin-1; D020880:Neuregulins; D018719:Erb-b2 Receptor Tyrosine Kinases; D020893:Receptor, ErbB-3; D066247:Receptor, ErbB-4; C491452:Nrg2 protein, rat; C108113:Nrg3 protein, mouse; C117467:neuregulin beta; C587689:ERBB4 protein, human; C483804:Erbb2 protein, rat; C587690:Erbb4 protein, mouse; C587691:Erbb4 protein, rat