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

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. J. Cell. Physiol. 226: 3251–3260, 2011. © 2011 Wiley Periodicals, Inc.