Axonal remyelination by cord blood stem cells after spinal cord injury.
Human umbilical cord blood stem cells (hUCB) hold great promise for therapeutic repair after spinal cord injury (SCI). Here, we present our preliminary investigations on axonal remyelination of injured spinal cord by transplanted hUCB. Adult male rats were subjected to moderate SCI using NYU Impactor, and hUCB were grafted into the site of injury one week after SCI. Immunohistochemical data provides evidence of differentiation of hUCB into several neural phenotypes including neurons, oligodendrocytes and astrocytes. Ultrastructural analysis of axons reveals that hUCB form morphologically normal appearing myelin sheaths around axons in the injured areas of spinal cord. Colocalization studies prove that oligodendrocytes derived from hUCB secrete neurotrophic hormones neurotrophin-3 (NT3) and brain-derived neurotrophic factor (BDNF). Cord blood stem cells aid in the synthesis of myelin basic protein (MBP) and proteolipid protein (PLP) of myelin in the injured areas, thereby facilitating the process of remyelination. Elevated levels of mRNA expression were observed for NT3, BDNF, MBP and PLP in hUCB-treated rats as revealed by fluorescent in situ hybridization (FISH) analysis. Recovery of hind limb locomotor function was also significantly enhanced in the hUCB-treated rats based on Basso-Beattie-Bresnahan (BBB) scores assessed 14 days after transplantation. These findings demonstrate that hUCB, when transplanted into the spinal cord 7 days after weight-drop injury, survive for at least 2 weeks, differentiate into oligodendrocytes and neurons, and enable improved locomotor function. Therefore, hUCB facilitate functional recovery after moderate SCI and may prove to be a useful therapeutic strategy to repair the injured spinal cord.
Dasari
Venkata Ramesh
VR
Program of Cancer Biology, Department of Cancer Biology and Pharmacology, University of Illinois College of Medicine at Peoria, Peoria, Illinois 61605, USA.
Spomar
Daniel G
DG
Gondi
Christopher S
CS
Sloffer
Christopher A
CA
Saving
Kay L
KL
Gujrati
Meena
M
Rao
Jasti S
JS
Dinh
Dzung H
DH
D000818:Animals; D001369:Axons / Q000502:physiology*; D036101:Cord Blood Stem Cell Transplantation; D006614:Hindlimb / Q000503:physiopathology; D006801:Humans; D008297:Male; D009043:Motor Activity / Q000502:physiology; D009186:Myelin Sheath / Q000502:physiology*; D009414:Nerve Growth Factors / Q000378:metabolism; D051381:Rats; D020127:Recovery of Function / Q000502:physiology; D012038:Regeneration / Q000502:physiology*; D013119:Spinal Cord Injuries / Q000378:metabolism / Q000503:physiopathology* / Q000628:therapy*; D013904:Thoracic Vertebrae
D009414:Nerve Growth Factors