TGF-beta 2 attenuates the injury-induced death of mature motoneurons.
The distributions of transforming growth factor-betas (TGF-betas) and their receptors suggest that the TGF-betas regulate motoneuron survival. This hypothesis was tested by avulsing the hypoglossal nerve of adult rats and perfusing either TGF-beta 2 or vehicle adjacent to the hypoglossal nucleus. By 4 weeks, half of the avulsed motoneurons had died. Infusion of 6 ng of TGF-beta 2 adjacent to the avulsed motor nucleus caused a significant attenuation of this death. This dose of TGF-beta 2 is low compared to that used with GDNF or BDNF in previous studies of avulsed motoneurons, indicating that TGF-beta 2 may be one of the more potent survival factors for adult motoneurons. TGF-beta 2 was, however, unable to prevent or reduce the axotomy-induced down regulation of choline acetyltransferase. Other motoneuron survival factors also have a narrow-spectrum of actions, suggesting that the homeostasis of motoneurons is regulated by a cocktail of growth factors with distinct but partially overlapping actions.
Jiang
Y
Y
Department of Anatomy and Structural Biology, University of Otago, Dunedin, New Zealand.
Zhang
M
M
Koishi
K
K
McLennan
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IS
D000818:Animals; D019771:Axotomy; D016923:Cell Death / Q000187:drug effects* / Q000502:physiology; D002795:Choline O-Acetyltransferase / Q000187:drug effects* / Q000378:metabolism; D005260:Female; D007002:Hypoglossal Nerve / Q000187:drug effects* / Q000502:physiology; D061228:Hypoglossal Nerve Injuries; D008297:Male; D009046:Motor Neurons / Q000187:drug effects* / Q000502:physiology; D051381:Rats; D016212:Transforming Growth Factor beta / Q000494:pharmacology*; D053781:Transforming Growth Factor beta2
D016212:Transforming Growth Factor beta; D053781:Transforming Growth Factor beta2; D002795:Choline O-Acetyltransferase