Laminin-1 induces neurite outgrowth in human mesenchymal stem cells in serum/differentiation factors-free conditions through activation of FAK-MEK/ERK signaling pathways.
Mesenchymal stem cells (MSCs) can be differentiated into cell types derived from all three germ layers by manipulating culture conditions in vitro. A multitude of growth and differentiation factors have been employed for driving MSCs towards a neuronal phenotype. In the present study, we investigated the potential of extracellular matrix (ECM) proteins-fibronectin, collagen-1, collagen-IV, laminin-1, and laminin-10/11, to induce a neuronal phenotype in bone marrow derived human MSCs in the absence of growth factors/differentiating agents. All of the ECM proteins tested were found to support adhesion of MSCs to different extents. However, direct interaction only with laminin-1 triggered sprouting of neurite-like processes. Cells plated on laminin-1 exhibited neurite out growth as early as 3h, and by 24h, the cells developed elaborate neurites with contracted cell bodies and neuronal-like morphology. Function-blocking antibodies directed against alpha6 and beta1 integrin subunits inhibited neurite formation on laminin-1 which confirmed the involvement of integrin alpha6beta1 in neurite outgrowth. Mechanistic studies revealed that cell adhesion to laminin-1 activated focal adhesion kinase (FAK), and mitogen-activated protein kinase kinase/extracellular signal-regulated kinase (MEK/ERK) signaling pathways. Abrogation of FAK phosphorylation by herbimycin-A inhibited neurite formation and also decreased activities of MEK and ERK. Pharmacological inhibitors of MEK (U0126) and ERK (PD98059) also blocked neurite outgrowth in cells plated on laminin-1. Our study demonstrates the involvement of integrin alpha6beta1 and FAK-MEK/ERK signaling pathways in laminin-1-induced neurite outgrowth in MSCs in the absence of serum and differentiation factors.
Mruthyunjaya
S
S
National Centre for Cell Science, Ganeshkhind, Pune 411007, India.
Manchanda
Rumma
R
Godbole
Ravibhushan
R
Pujari
Radha
R
Shiras
Anjali
A
Shastry
Padma
P
D002448:Cell Adhesion; D024042:Collagen Type I / Q000378:metabolism / Q000494:pharmacology; D024141:Collagen Type IV / Q000378:metabolism / Q000494:pharmacology; D048049:Extracellular Signal-Regulated MAP Kinases / Q000378:metabolism; D051416:Focal Adhesion Protein-Tyrosine Kinases / Q000378:metabolism; D006801:Humans; D039503:Integrin alpha6 / Q000378:metabolism; D039641:Integrin beta Chains / Q000378:metabolism; D007797:Laminin / Q000378:metabolism* / Q000494:pharmacology; D020930:MAP Kinase Kinase Kinases / Q000378:metabolism; D059630:Mesenchymal Stem Cells / Q000187:drug effects / Q000502:physiology*; D016501:Neurites / Q000502:physiology*; D055495:Neurogenesis; D009474:Neurons / Q000166:cytology* / Q000378:metabolism
D024042:Collagen Type I; D024141:Collagen Type IV; D039503:Integrin alpha6; D039641:Integrin beta Chains; D007797:Laminin; C121346:laminin 1; C119013:laminin 10; D051416:Focal Adhesion Protein-Tyrosine Kinases; D048049:Extracellular Signal-Regulated MAP Kinases; D020930:MAP Kinase Kinase Kinases