Mesenchymal stem cells in the treatment of spinal cord injuries: A review

Table 1 Overview of effects of bone marrow stromal cells after spinal cord injury

Source of MSC	Main pathological features improved/repaired	Limitations/recommendations/conclusions	Ref.
Human	Axonal growth, partial recovery of function	Differences in donor or lot-lot efficacy of MSC	Neuhuber et al[37], 2005
Human	Axonal growth, significant behavioral recovery	Survival of BMSC grafts for longer duration	Himes et al[38], 2006
Human	Significant motor improvements in human patients	Autologous bone marrow cell transplantation with GM-CSF administration has no serious complications. More comprehensive multicenter clinical studies are recommended	Park et al[52], 2005
Human	Homing of MSC, functional recovery	Mechanisms of engraftment, homing, long-term safety	Cizkova et al[42], 2006
Rhesus monkey	De novo neurogenesis and functional recovery in rhesus monkeys	Synergetic effects of MSC implantation and locally delivered neurotrophic factors in rhesus SCI models	Deng et al[54], 2006
Pig	Improvement in somatosensory-evoked potentials, functional recovery in pigs	Possible utility of BMSC transplantation in humans suffering from chronic paraplegia	Zurita et al[55], 2008
Rat	No allodynia, anti-inflammatory, increase in white matter volume and decrease in cyst size, sensorimotor enhancements	Survival of MSC	Abrams et al[39], 2009
Rat	MSC form bundles bridging the lesion epicenter, functional recovery	Neuron-like MSC lacked voltage-gated ion channels for generation of action potentials	Hofstetter et al[40], 2002
Rat	Cavity reduction, functional recovery	Unknown trophic factors secreted by BMSC	Ohta et al[41], 2004
Rat	Downregulation of apoptosis, functional recovery	Intrinsic properties of MSC, microenvironment of the injured spinal cord, host-graft interactions	Dasari et al[43], 2007
Rat/gerbil	Activation of survival signaling pathways, neuroprotection	Neuroprotective factors released by BMSC, interactions between neurons and BMSC	Isele et al[44], 2007
Rat	Axonal regeneration, myelination of axons	Resection of the chronic scar
Rat	Increase in spared white matter, functional recovery	Differences in mechanism of action of MSCs or BMCs (bone marrow cells) or G-CSF in inducing functional and morphological improvement	Urdzíková et al[46], 2006
Rat	Reduction in inflammation, promoting angiogenesis, and reducing cavity formation	GS scaffolds may serve as a potential supporting biomaterial for wound healing after SCI	Zeng et al[48], 2011
Rat	Extensive in-growth of serotonin-positive raphaespinal axons and calcitonin gene-related peptide-positive dorsal root sensory axons, attenuation of astroglial and microglial activity	Production of trophic factors support neuronal survival and axonal regeneration	Novikova et al[49], 2011
Rat	Functional recovery	Repetitive IT transplantation may improve behavioral function depending on optimization of dose, timing, and targeted IT delivery of MSCs	Cizkova et al[50], 2011
Rat	Axonal regeneration, functional recovery	Feasibility of therapeutic cell delivery using 3D scaffolds, especially in complete spinal cord transection	Kang et al[51], 2011
Rat	Partial improvement in ASIA score in human patients	Polymer hydrogels may become suitable materials for bridging cavities after SCI	Sykova et al[53], 2006

SCI: Spinal cord injury; MSC: Marrow stromal cell; IT: Intrathecal; CSF: Cerebrospinal fluid; GS: Gelatin sponge; BMSC: Bone marrow-derived mesenchymal stem cell.