Effect of TGFβ1 and nAG on Astrocyte Cultures: A Study of Astrocyte Proliferation and the Expression of GFAP, CSPG4, S100B and IL-6.

OBJECTIVE: To determine the effects of TGFβ1 and an anti-scar protein nAG on normal (un-injured) 3-D astrocyte cultures with special emphasis on astrocyte proliferation, and the expression of GFAP, CSPG4, S100B, and IL-6. STUDY DESIGN: An experimental study. PLACE AND DURATION OF STUDY: King Saud University, Riyadh, Saudi Arabia, from March to September 2017. METHODOLOGY: 3-D astrocyte gels were treated differently to create one control group (control, untreated astrocytes) and five experimental groups: nAg-only (treated astrocytes with 1 nM nAG recombinant protein), TGFβ1-only (treated astrocytes with 10 ng/ml TGFβ1), TGFβ1+low nAg concentration, TGFβ1+intermediate nAg concentration, and TGFβ1+high nAg concentration. Astrocyte proliferation, and the expression of GFAP, CSPG4, S100B, and IL-6 were studied and compared in these experimental groups. RESULTS: There were major differences in the responses of normal astrocytes in vitro versus the responses of astrocytes in vivo in the setting of injury or disease. The effects of TGFβ1 were dominant over the effects of nAG with regard to changes in CSPG4 and S100B by Real-Time PCR. There was a synergistic inhibitory effect of TGF1 and nAG on the expression of CSPG4 by Western blot. CONCLUSION: The different responses of normal astrocytes in vitro versus astrocytes in vivo in the setting of injury or disease. The response at the gene level might not coincide with the response at the protein level.