Role of laminin-111 in neurotrophin-3 production of canine adipose-derived stem cells: Involvement of Akt, mTOR, and p70S6K

Abstract

Extracellular matrix (ECM) components play an important role in the regulation and maintenance of neural stem cells (NSCs). Laminin, an ECM component, is a key factor in promoting axonal regeneration and differentiation of NSCs. Since NSCs cannot be easily harvested with low morbidity, adipose-derived stem cells have been suggested for therapeutic applications of neural tissue damage. Therefore, the potential of laminin-111 to enhance the production of neurotrophin-3 (NT3) and its related signal pathways from canine adipose tissue-derived stem cells (cADSCs) was investigated. Laminin-111 enhanced NT3 production in neural induction medium (NIM). Treatment of NIM or laminin-111 on cADSCs distinctively changed integrin β1 mRNA and protein expression levels. In addition, laminin-111-induced Akt phosphorylation was inhibited by integrin β1 small interfering RNA (siRNA) and PI3K inhibitors (LY294002 and wortmannin). Furthermore, increased phosphorylations of mTOR and p70S6K by laminin-111 were blocked by inhibitors or specific siRNA, respectively. Moreover, laminin-111-induced NT3 production was blocked by these inhibitors. In experiments to induce the differentiation of cADSCs, laminin-111 increased the expression of neuronal markers β 3 tubulin, MAP2, and NeuN, and decreased the expression of the NSC markers nestin and vimentin. In conclusion, laminin-111 increases NT3 production through Akt, mTOR, and p70S6K pathways via integrin β1 in cADSCs cultured in NIM.