Roles of platelet-derived growth factor-B expression in the ventral horn and motor cortex in the spinal cord-hemisected rhesus monkey.
It is well known that platelet-derived growth factor-B (PDGF-B), a member of the neurotrophic factor family, is involved in normal physiological conditions, pathological changes, and neuroregulation following lesions. But the roles of endogenous PDGF-B in neuroregulation following spinal cord injury are far from being well known, especially in primates. This study explored the role of PDGF-B in the spinal cord and motor cortex in rhesus monkeys subjected to cord hemisection. Evaluation of the hindlimb motor function and the cortical somatosensory evoked potentials (CSEP) demonstrated a significant partial recovery from 30 days post-operation (dpo) to 90 dpo. Immunostaining revealed PDGF-B expression in neurons and scattered macrophages in the spinal cord. The number of PDGF-B immunoreactive neurons in the ventral horn of the spinal cord decreased significantly at the injury site at 14 dpo, followed by a rapid increase that surpassed the numbers in the control group at 30 dpo, and remained at these levels until 90 dpo. The protein levels of PDGF-B and platelet-derived growth factor receptor-beta (PDGFR-beta) as assessed by Western blot, as well as the mRNA levels of PDGF-B as assessed by RT-PCR demonstrated a tendency similar to that seen with immunohistochemistry. PDGF-B antibody administration effectively decreased locomotor function in the hindlimbs, especially on the injured side. No PDGF-B immunoreactive cells were detected in the motor cortex. Taken together, the present findings indicate that intrinsic PDGF-B expressed in the spinal cord may play an essential role in neuroregulation in primates following cord hemisection.
Xiyang
Yan-Bin
YB
Institute of Neurological Disease, West China Hospital, Sichuan University, Chengdu, China.
Liu
Su
S
Liu
Jia
J
Hao
Chun-Guang
CG
Wang
Zhao-Jun
ZJ
Ni
Wei
W
Wang
Xu-Yang
XY
Wang
Ting-Hua
TH
D000818:Animals; D000870:Anterior Horn Cells / Q000502:physiology*; D000900:Anti-Bacterial Agents / Q000494:pharmacology; D015153:Blotting, Western; D002452:Cell Count; D005073:Evoked Potentials, Somatosensory / Q000502:physiology*; D015870:Gene Expression / Q000502:physiology; D006614:Hindlimb / Q000294:innervation / Q000502:physiology; D008253:Macaca mulatta; D009043:Motor Activity / Q000502:physiology; D009044:Motor Cortex / Q000502:physiology*; D020574:Proto-Oncogene Proteins c-sis / Q000235:genetics* / Q000276:immunology / Q000378:metabolism*; D020127:Recovery of Function; D020133:Reverse Transcriptase Polymerase Chain Reaction; D013119:Spinal Cord Injuries / Q000473:pathology / Q000503:physiopathology*
D000900:Anti-Bacterial Agents; D020574:Proto-Oncogene Proteins c-sis