Neural differentiation from pluripotent stem cells: The role of natural and synthetic extracellular matrix

Table 1 Protocols and in vivo studies for oligodendrocyte progenitor cells differentiation from human pluripotent stem cells

Growth factors	Cell source	Cell characteristics	Ref.
EGF-dependent protocol
RA/EGF (short FGF-2 exposure)	hESC lines: H1 and H7	Olig1 (80%-90%), Sox10 (76%-84%), NG2 (95%); remyelinated in a rat thoracic contusion model	Nistor et al[21], 2005; Keirstead et al[19], 2006; Li et al[13], 2013
RA/EGF (short FGF-2 exposure)	hiPSC lines: Royan hiPSC1, hiPSC8	> 90% Olig2, Sox 10, > 80% NG2 and PDGFRα; tested in a rat model of optic chiasm demyelination	Pouya et al[33], 2011
RA/EGF (short FGF-2 exposure)	hESC H7 line	OPCs remyelinated in a rat cervical contusion model	Sharp et al[94], 2010
RA/EGF (short FGF-2 exposure)	hiPSC lines: 201B7, 253G1	O4+ cells were observed in EGF-dependent protocol	Ogawa et al[20], 2011
PDGF-dependent protocol
PDGF/FGF-2 (short EGF exposure)	SNUhES1 line	PDGFRα (81%), A2B5 (90.4%), NG2 (91.3%) and O1 (81%); myelinate axons in co-cultures with fetus hippocampal neurons.	Kang et al[24], 2007
RA/Shh/FGF-2/PDGF	hESC lines: H1, H9 H14	> 80% PDGFRα+, also co-express Olig2, Nkx2.2, Sox10 and NG2	Hu et al[26], 2009
RA/Shh/FGF-2/PDGF	hiPSC lines: K04, C14, and C27	70%-90% Olig2+/Nkx2.2+, OPCs myelinated the brains of myelin-deficient shiverer mice	Wang et al[7], 2013
FGF-2/EGF/PDGF/CNTF plus laminin; Shh, PDGF, IGF-1, EGF, FGF-2 and CNTF plus RA and laminin	hESC lines: HS360 and HS362; Regea 06/040 and Regea 08/023	> 90% NG2+, > 80% PDGFRα+; multilayered myelin sheet formation around axons was detected in co-culture with neuronal cells	Sundberg et al[28], 2010 Sundberg et al[27], 2011
Noggin/FGF-2/FGF-4/PDGF/EGF	hESC H1 line	> 95% cells expressing Sox10, A2B5, PDGFRα, NG2, O4, O1; increased neurological response in a rat contusion model	Kerr et al[29], 2010

RA: Retinoic acid; EGF: Epidermal growth factor; FGF-2: Fibroblast growth factor 2; hESC: Human embryonic stem cell; hiPSC: Human induced pluripotent stem cell; PDGFR: Platelet-derived growth factor receptor; PDGF: Platelet-derived growth factor; Shh: Sonic hedgehog; CNTF: Ciliary neurotrophic factor; IGF-1: Insulin-like growth factor-1.

Table 2 Effects of extracellular matrices proteins on neural differentiation of pluripotent stem cells

ECM protein	Integrins	Cell source	Neural differentiation	Ref.
Laminin Matrigel (rich in laminin)	α6β1 α3β1	HESC lines: TE03 and TE06	Neuronal generation and neurite outgrowth were significantly greater on laminin and laminin-rich Matrigel than fibronectin, poly-D-lysine, and collagen I	Ma et al[16], 2008
Fibronectin	α5β1	Oligodendrocyte progenitor cells from rats	Promoted OPC survival, proliferation, migration, process extension, and OPC purity	Hu et al[35], 2009
Vitronectin	αvβ1, αvβ3, αvβ5	hESC lines: Miz-hES4, Miz-hES6	Promoted oligodendrocyte differentiation in the presence of RA/Shh/Noggin	Gil et al[36], 2009
Collagen IV	α1β1, α10β1	Rabbit neural progenitor cells	Conducive for both neuronal and glial cell differentiation	Raghavan et al[61], 2013
Collagen I	α2β1	Rabbit neural progenitor cells	Conducive for both neuronal and glial cell differentiation	Raghavan et al[61], 2013
Vitronectin-derived synthetic peptide acrylate surface	αvβ5	hESC line: H1	Promoted oligodendrocyte progenitor differentiation; higher NG2 expression compared to Matrigel	Li et al[13], 2013
Heparan sulfate	Binding heparin	Rabbit neural progenitor cells	Addition of heparan sulfate to collagen mixtures improved neuronal differentiation	Raghavan et al[61], 2013

ECM: Extracellular matrix; hESC: Human embryonic stem cells; RA: Retinoic acid; Shh: Sonic hedgehog; OPC: Oligodendrocyte progenitor cells.

Table 3 Protocols and in vivo studies for neural progenitor cells differentiation from human pluripotent stem cells

Growth factors	Cell source	Cell characteristics	Ref.
EB-based protocol
FGF-2/RA/ascorbic acid, db-cAMP, HAg	16 hiPSC lines	13 of the cell lines produced functional motor neurons. Treat with BDNF, GDNF, CNTF to produce motor neurons (4%-15% ISL+ neurons)	Boulting et al[43], 2011
RA/FGF-2	hESC lines: H7, hCSC14, hCSC14-CL1	Produce neuronal progenitors (> 95% nestin and Musashi-1), can become cholinergic neurons, GABA neurons, etc	Nistor et al[47], 2011
Isolated Rosette expanded with EGF/FGF-2	hiPSC lines	Generate long-term expandable neuro-epithelial like stem cells (Lt-NES); in stoke model, the cells improved recovery of fine forelimb movements	Oki et al[53], 2012
RA/Shh	hESC lines H1 and H9	To generate motor neurons (50% HB9+ motor neurons)	Hu et al[51], 2009
Monolayer-based protocol
Noggin and SB431542	hESC line: H9 hiPSC lines: iPS-14, iPS-27	> 80% PAX6+ cells; Shh/FGF8 for midbrain dopamine neurons; BDNF, Shh, RA, ascorbic acid for motor neurons	Chambers et al[12], 2009
Noggin and SB431542	hESC line: H9 hiPSC line: 253G4	Treat BDNF, GDNF, NT-3 for forebrain neurons which secrete Aβ for drug screening.	Yahata et al[52], 2011
Noggin only; FGF-2 may be added at later stage	hESC line: H1, H7, H9	> 90% nestin, musashi, and PSA-NCAM; For TH neurons, add Shh/FGF8/ascorbic acid; followed by BDNF, GDNF, ascorbic acid and laminin	Gerrard et al[48], 2005
FGF-2	hESC line: SA002 and AS034	> 90% nestin, NCAM; For neuronal lineage, add Shh/FGF8; after differentiation TH+ cells, MAPab+ cells and astrocytes existed	Axell et al[49], 2009

EB: Embryoid body; FGF-2: Fibroblast growth factor-2; RA: Retinoic acid; db-cAMP: Dibutyryl-cAMP; HAg: A small molecule agonist of the sonic hedgehog pathway; hESC: Human embryonic stem cell; hiPSC: Human induced pluripotent stem cell; BDNF: Brain-derived neurotrophic factor; GDNF: Glial cell-derived neurotrophic factor; CNTF: Ciliary neurotrophic factor; GABA: Gamma-Aminobutyric acid; Shh: Sonic hedgehog; NT-3: Neurotrophin-3; PSA-NCAM: Polysialylated-neural cell adhesion molecule; TH: Tyrosine hydroxylase; NCAM: Neural cell adhesion molecule.

Table 4 Three-dimensional natural and synthetic extracellular matrices scaffolds for neural differentiation of pluripotent stem cells

Scaffolds	Cell source	Neural differentiation	Ref.
Poly(lactic-co-glycolic acid) and poly(L- lactic acid) scaffolds	hESC	Enhanced numbers of neural structures and staining of nestin and β-tubulin III were observed	Levenberg et al[74], 2005
Synthetic hydrogel matrix PuraMatrix	hESC-derived neuronal cells	HESC-derived neurons, astrocytes, and oligodendrocytes grew, matured and migrated in hydrogel; neuronal cells had electrically active connections.	Ylä-Outinen et al[76], 2012
Poly(epsilon-caprolactone)-poly(beta-hydroxybutyrate) scaffolds	Mouse iPSCs	Improved iPSCs to differentiate into neurons and inhibited other differentiations.	Kuo et al[79], 2012
Polycaprolactone nanofiber matrices	HESC-derived neural precursors	Aligned fibrous matrices showed higher rate of neuronal differentiation compared to random micro- and nano- fibers (62%-86% vs 27%-32%).	Mahairaki et al[77], 2011
Polyurethane nanofibrous scaffolds	hESC line SA002	Neuronal differentiation was preferred over astrocyte differentiation.	Carlberg et al[80], 2009
Tissue-engineered fibrin scaffolds	Mouse ESC-derived NPCs	Enhanced NPC survival and directed differentiation into neurons.	Johnson et al[82], 2010
PET microfibrous scaffolds	Mouse ESC D3 line	Enhanced neuronal differentiation indicated by nestin, Nurr1, and tyrosine hydroxylase compared to 2-D culture.	Liu et al[84,85], 2013, 2013
Multiwalled carbon nanotube modified PET microfibrous scaffolds	Mouse ESC D3 line	Enhanced neuronal differentiation compared to unmodified scaffolds	Zang et al[83], 2013
Chitin-alginate 3-D microfibrous scaffolds	hESC line: HUES 7 hiPSC lines: PD-iPS5 and hFib2-iPS4	Efficient neuronal differentiation: > 95% nestin+; able to mature into neurons (> 90% β-tubulin III+)	Lu et al[75], 2012
3-D ECM scaffolds derived from ESC aggregates	Mouse ESC D3 line	ECM scaffolds derived from RA-treated EBs enhanced nestin and β-tubulin III expressions	Sart et al[60], 2013
Inverted colloidal crystal (ICC) scaffolds containing alginate, poly(gamma- glutamic acid), and surface peptide; or chitin-chitosan-gelatin ICC scaffolds	Mouse iPSCs	Accelerated neuronal differentiation (β-tubulin III expression) of iPSCs.	Kuo et al[86,87], 2013, 2013

hESCs: Human embryonic stem cells; iPSCs: Induced pluripotent stem cells; NPC: Neural progenitor cells; PET: Poly(ethylene terephthalate); ECM: Extracellular matrix; RA: Retinoic acid; EB: Embryoid body.