The effect of BIO, a specific GSK3-Β inhibitor, on the expression of neuroprotective factor Tgfβ in cultured astrocytes

Astrocytes are the most important glial cells of the central nervous system, ten times as much as neurons and with the ability of neuroprotection against injuries, ischemia, etc. Apoptosis of the astrocytes therefore leads to disease progression in neurodegenerative pateints such as Alzheimer's and Parkinson's diseases. Investigations on possible signaling pathway (s) involved in neuron death suggest that GSK3-β "glycogen synthase kinase-3β", a key molecule of the Wnt and PI-3 kinase signaling pathways, is considerably increased in neurodegenerative diseases. In this study we sought to determine if the expression of neuroprotective factors such as TGFβ1 and TGFβ2 in cultured astrocytes is altered by inhibition of GSK3-β. Different concentrations of BIO, a specific inhibitor of GSK3-β (0.1 µM, 0.5 µM and 1µM) were therefore used. The treated and control astrocytes were isolated after 48 hours and monitored for the expression of TGFβ1mRNA and TGFβ2mRNA using real-time RT-PCR. Our results show that the BIO treated cells express much higher amounts of TGFβ1 and TGFβ2 in comparison with the control cells. The increased expression of TGFβs following the inhibition of GSK3-β points at the involvement of GSK3-β in neuroprotective activity of astrocytes.