Effect of bone marrow mesenchymal stem cells on microglial activation after optic nerve injury in rats / 中国组织工程研究

BACKGROUND: Traumatic optic nerve injury is an important cause of vision loss, and the treatment methods are relatively limited. In order to find a better treatment method, this experiment started from the direction of microglia. Under neuropathological conditions, activation of microglia can maintain the stability of the central nervous system, but excessive activation of microglia can produce a large number of inflammatory factors that progressively aggravate the damage. OBJECTIVE: To investigate the activation of microglia after optic nerve injury and the effect of bone marrow mesenchymal stem cells (BMSCs) on the overexpression of microglia. METHODS: There were 18 Sprague-Dawley rats, 8 weeks of age, which were divided into BMSCs transplantation group, model group and sham operation group, with 6 rats in each group. In the model group and BMSCs transplantation group, the rat’s left eye was selected to separate the retina and optic nerve after the optic clamping of the optic nerve. The sham operation group only separated the retina and optic nerve with no clamping. In the BMSCs transplantation group, the left eye vitreous body was injected with quantitative passage 3 BMSCs (1×108 cells, 2 μL) immediately after the injury. While in the model group and sham operation group, the same amount of PBS was injected into the vitreous body. All the rats were sacrificed at 15 days postoperatively. After perfusion and fixation, the retina with optic nerve was taken for hematoxylin-eosin staining and immunohistochemical detection. RESULTS AND CONCLUSION: The expression levels of Ox-42 and tumor necrosis factor α were significantly higher in the model group than in the sham operation group (P < 0.05), while the expression of Ox-42 and tumor necrosis factor α in the optic nerve and retina in the BMSCs group was decreased and almost the same to that in the sham operation group. Therefore, excessive activation of microglia is associated with optic nerve injury, and BMSCs can inhibit the excessive activation of microglia and release of inflammatory factors, thus protecting the retina and optic nerve from traumatic injury to some extent.

Transplantation of rat-derived microglial cells promotes functional recovery in a rat model of spinal cord injury

This study evaluated the effect of microglia transplantation on neurological functional recovery in rats subjected to traumatic spinal cord injury (SCI). The rat model of SCI was established using a weight drop device. Forty SCI rats were randomly divided into the microglia group and the saline group. Then, rat-derived microglial cells or normal saline was injected into the injured site 7 days after surgery. The Basso-Beattie-Bresnahan (BBB) score, inclined plate test, and motor-evoked potentials (MEPs) were applied to assess the recovery of motor function. Hematoxylin and eosin (H&E) staining was used to assess the therapeutic effect. Microglia transplantation significantly improved BBB scores and functional scores at 2, 3, 4, 6, and 8 weeks after surgery compared to saline injection (P<0.05). Meanwhile, a prolonged MEP latency and decreased MEP amplitude were observed at 4 and 8 weeks in the microglia group (P<0.05). Histological analysis showed less damage and better prognosis in SCI rats of the microglia group. BrdU+ cell tracing experiments showed that microglia were recruited to the injured area of the spinal cord at 7 and 14 days after transplantation. The intensity of immunofluorescence was increased in CD68+ and OX42+ microglia at 2 days, 1 week, and 2 weeks, and then decreased at 3 and 4 weeks after transplantation in the microglia group. The transplantation of activated microglia played a key role in promoting the recovery of spinal cord function in a rat model of SCI.

Peripheral N-methyl-D-aspartate Receptors Involved in Long-term Hyperalgesia Induced by Peripheral Injection of Formalin in Rats / 中国康复理论与实践

@#Objective To investigate the role of peripheral N-methyl-D-aspartate (NMDA) receptors in the long-term hyperalgesia induced by peripheral injection of formalin in rats. Methods Formalin was injected in the paws of the SD rats with or without the MK-801 pre-injection. OX-42 expressions in the dorsal horn were observed, and the paw withdrawal thermal latency was measured. Results The OX-42 expression decreased and the paw withdrawal thermal latency prolonged in rats with MK-801 pre-injection. Conclusion Peripheral NMDA receptors may be involved in the long-term hyperalgesia.

Effects of interventional administration of L-Arginine or nitroglycerin on acute local cerebral ischemia in rats / 基础医学与临床

Objective To observe the effects of treating acute ischemic stroke in rats with interventional administration of nitric oxide precurcer L-Arginine or nitric oxide donor nitroglycerin.Methods The right middle cerebral arteries of rats were occluded by insertion of a suture to duplicate ischemia-reperfusion models.Forty-two male SD rats were randomly divided into four groups: MCAO group(n=12);sham operation group(n=6);NG group(n=12) and L-ARG group(n=12),intracarotid arteries administrated respectively by NS、NS、NG and ARG.Each of the four groups were subdivided into 2 groups according to the reperfusion time(3 h and 24 h),measurement of Longa scores,NO2-/NO3-in serum,HE staining and immunohistochemical(SABC)method were utilized to assess the changes of ischemic brain tissues in different groups.Results OX-42 positive cells of cortex and CA3 area of hippocampal: OX-42 positive cells were found,their features identified at 3 h after reperfusion.24 h the response of microglias was obvious,the number of the cells increased(P

Effects of repetitive transcranial magnetic stimulation on GFAP and OX-42 expression in hippocampus and dentate gyrus in rats / 临床神经病学杂志

Objective To observe the effects of repetitive transcranial magnetic stimulation (rTMS) on the expression of glial fibrillary acidic protein (GFAP) and OX-42 in hippocampus and dentate gyrus in rats.Methods The rats were treated with 1 Hz, 100 mT TMS 10 min once a day for 14 days, and then the expression of GFAP and OX-42 in hippocampus and dentate gyrus were investigated by ABC technique of immunohistochemistry.Results Compared with the control group, there were no significant difference in the expression of GFAP and OX-42 between the two groups.Conclusion rTMS using our parameters does not cause brain injury in rats.