Neural differentiation of human mesenchymal stem cells: Evidence for expression of neural markers and eag K+ channel types.
OBJECTIVE
Mesenchymal stem cells (MSCs) are multipotent cells that can self-renew, proliferate, and exhibit elevated cellular plasticity. To investigate their possible neural fate, we studied human mesenchymal stem cells (hMSCs) in different cell culture conditions from morphological, immunochemical, gene expression, and physiological points of view.


METHODS
We tested hMSCs in three previously reported experimental conditions made of alpha-modified minimum essential medium (alpha-MEM)/1 mM beta-mercaptoethanol (betaME), 10 microM alpha-MEM/retinoic acid (RA) or alpha-MEM/2% dimethylsulfoxide (DMSO) + 200 microM beta-hydroxyanisole (BHA), respectively, and in a new experimental condition with neural progenitor maintenance medium (NPMM).


RESULTS
hMSCs were isolated from bone marrow and expanded for several passages. In betaME, cells became immunoreactive for neuronal nuclear antigen (NeuN), neuron-specific enolase (NSE), Nestin, and glial fibrillary acidic protein (GFAP). In experimental conditions with RA and DMSO/BHA, hMSCs were NeuN and NSE-positive while in NPMM they were positive for GFAP and NSE. Untreated hMSCs showed a weak mRNA expression for microtubule-associated protein, NSE, and neurofilament protein-medium and GFAP, which strongly increased in NPMM-treated hMSCs. In the electrophysiological study, NPMM-differentiated hMSCs expressed two delayed rectifier K+ currents related to two ether-à-go-go K+ channels (eag1, eag2), which are fundamental for setting the negative resting potentials required for neuronal survival and basal cell activity. The two K+ channels were absent in undifferentiated hMSCs. These data were confirmed by real-time polymerase chain reaction.


CONCLUSIONS
In our new culture condition, hMSCs acquired new morphological characteristics, neural markers, and electrophysiological properties, which are suggestive of neural differentiation. This might lead to clinical use of hMSCs in neural degenerative diseases.
Mareschi
Katia
K
Department of Pediatrics, Regina Margherita Children's Hospital, The Oncogenomics Center, Institute for Cancer Research and Treatment (IRCC), University of Turin, Turin, Italy.
Novara
Monica
M
Rustichelli
Deborah
D
Ferrero
Ivana
I
Guido
Daniela
D
Carbone
Emilio
E
Medico
Enzo
E
Madon
Enrico
E
Vercelli
Alessandro
A
Fagioli
Franca
F
D018929:Cell Culture Techniques / Q000379:methods; D002454:Cell Differentiation / Q000187:drug effects / Q000502:physiology; D002478:Cells, Cultured; D003470:Culture Media / Q000494:pharmacology; D004121:Dimethyl Sulfoxide / Q000494:pharmacology; D051638:Ether-A-Go-Go Potassium Channels / Q000096:biosynthesis* / Q000187:drug effects; D006801:Humans; D006854:Hydrocortisone / Q000494:pharmacology; D008623:Mercaptoethanol / Q000494:pharmacology; D059630:Mesenchymal Stem Cells / Q000166:cytology / Q000187:drug effects / Q000502:physiology*; D009419:Nerve Tissue Proteins / Q000096:biosynthesis* / Q000187:drug effects; D009474:Neurons / Q000166:cytology / Q000187:drug effects / Q000502:physiology*; D009930:Organic Chemicals / Q000494:pharmacology; D010751:Phosphopyruvate Hydratase / Q000096:biosynthesis* / Q000187:drug effects; D014212:Tretinoin / Q000494:pharmacology
D003470:Culture Media; D051638:Ether-A-Go-Go Potassium Channels; D009419:Nerve Tissue Proteins; D009930:Organic Chemicals; C420642:alpha minimal essential medium; D014212:Tretinoin; D008623:Mercaptoethanol; D010751:Phosphopyruvate Hydratase; D006854:Hydrocortisone; D004121:Dimethyl Sulfoxide