Growth hormone pathways signaling for cell proliferation and survival in hippocampal neural precursors from postnatal mice
1 Department of Physiology, School of Medicine, University of Santiago de Compostela, 15710 Santiago de Compostela, Spain
2 Neuroprotection and Neurogenesis in Brain Repair Group, Center for Neuroscience and Cell Biology, School of Medicine, University of Coimbra, 3004-517 Coimbra, Portugal
3 Medical Center Proyecto Foltra, Travesía de Montouto 24, 15886 Teo, Spain
BMC Neuroscience 2014, 15:100 doi:10.1186/1471-2202-15-100Published: 26 August 2014
Accumulating evidence suggests that growth hormone (GH) may play a major role in the regulation of postnatal neurogenesis, thus supporting the possibility that it may be also involved in promoting brain repair after brain injury. In order to gain further insight on this possibility, in this study we have investigated the pathways signaling the effect of GH treatment on the proliferation and survival of hippocampal subgranular zone (SGZ)-derived neurospheres.
Our results demonstrate that GH treatment promotes both proliferation and survival of SGZ neurospheres. By using specific chemical inhibitors we have been also able to demonstrate that GH treatment promotes the activation of both Akt-mTOR and JNK signaling pathways, while blockade of these pathways either reduces or abolishes the GH effects. In contrast, no effect of GH on the activation of the Ras-ERK pathway was observed after GH treatment, despite blockade of this signaling path also resulted in a significant reduction of GH effects. Interestingly, SGZ cells were also capable of producing GH, and blockade of endogenous GH also resulted in a decrease in the proliferation and survival of SGZ neurospheres.
Altogether, our findings suggest that GH treatment may promote the proliferation and survival of neural progenitors. This effect may be elicited by cooperating with locally-produced GH in order to increase the response of neural progenitors to adequate stimuli. On this view, the possibility of using GH treatment to promote neurogenesis and cell survival in some acquired neural injuries may be envisaged.