Small stress protein Hsp27 accumulation during dopamine-mediated differentiation of rat olfactory neurons counteracts apoptosis.
The small stress protein Hsp27 is expressed during mammalian neural development. We have analyzed the role of this protein in immortalized rat olfactory neuroblasts. In the presence of dopamine a fraction of these cells differentiate into neurons while the remaining cells undergo apoptosis. We report here that the dopamine induced differentiation and apoptosis are associated with a transient and specific accumulation of Hsp27. Moreover, transfection experiments have shown that Hsp27 overexpression drastically decreases the fraction of cells undergoing apoptosis. In contrast, reduction of the endogenous level of Hsp27 led to abortion of differentiation and, therefore, drastically increased the number of apoptotic cells. Furthermore, in the normal cell population we show that Hsp27 accumulation takes place only in differentiating cells that were not undergoing apoptosis. We therefore conclude that Hsp27 may represent a key protein that controls the decision of olfactory precursor cells to undergo either differentiation or cell death.
Mehlen
P
P
Apoptosis/Differentiation Laboratory, CNRS-UMR-5534, Claude Bernard University, Lyon-I, F-69622 Villeurbanne, France.
Coronas
V
V
Ljubic-Thibal
V
V
Ducasse
C
C
Granger
L
L
Jourdan
F
F
Arrigo
A P
AP
D000818:Animals; D017209:Apoptosis / Q000187:drug effects / Q000502:physiology; D002454:Cell Differentiation / Q000187:drug effects / Q000502:physiology; D002460:Cell Line; D004298:Dopamine / Q000494:pharmacology*; D015870:Gene Expression; D055551:HSP27 Heat-Shock Proteins; D006360:Heat-Shock Proteins / Q000235:genetics / Q000378:metabolism*; D009363:Neoplasm Proteins / Q000235:genetics / Q000378:metabolism*; D018034:Olfactory Receptor Neurons / Q000166:cytology / Q000187:drug effects* / Q000378:metabolism*; D051381:Rats; D014162:Transfection
D055551:HSP27 Heat-Shock Proteins; D006360:Heat-Shock Proteins; C486114:Hspb1 protein, rat; D009363:Neoplasm Proteins; D004298:Dopamine