Preliminary Research On The Treatment Of Spinal Cord Ischemic Reperfusion Injury In Rats Via Bone Marrow Mesenchymal Stem Cells Which Was Modified By Hypoxia-inducible Factor-1α

Spinal cord injury is a primary damage which was caused by spinal cord trauma,aortic artery occlusion surgery, spinal surgery and lower perfusion pressure etc. After theperfusion was recovered, the tissue could get more hurt. This process was called spinalcord ischemia reperfusion injury (SCII). At present, the treatment methods of SCIIinclude drug treatment, bypass surgery, low temperature protection technique, to name justa few. But the effects were not significant. So, how to reduce or protect SCII is asignificant problem to be solved. Numerous studies have demonstrated that thepathophysiology process of SCII is complex and many factors occur with it, and themechanism of SCII was not clear.Recently, the development of cell transplantation technique and genetically modifiedtechnology provide a new treatment method of SCII. The crucial factor is how to choosethe appropriate cell or gene. Hypoxia inducible factor-1(HIF-1) is an important transcription factor which has a significant role in the adaption of hypoxia both in cell andtissue. It may against hypoxic environment, promote angiogenesis, reconstruction ofmicrocirculation and relieve spinal cord injury[1]. Bone marrow mesenchymal stem cells(BMSCs) have a multidirectional differentiation potential and low immunogenicity. Theymay differentiate into neurons, osteoblasts, adipocytes cells, etc[2]. Because of thesefactors, it is the most application prospect of cells for transplant. We will transfect HIF-1αinto BMSCs, and discuss the preliminary role of HIF-1α-BMSCs in SCII.Objection:Observe the effect of the neural function of spinal cord ischemia reperfusion injuryby using HIF-1α-BMSCs through intrathecal injection. Observe the expression levels ofHIF-1α in SCII tissue.Methods:Adult healthy male Sprague Dawley rats were randomly divided into4groups, whichincludes Sham group (only exposed the abdominal aorta), SCII group (intrathecalinjection of5ul saline after the establishment of SCII model), BMSCs group (intrathecalinjection of1×106/5ul BMSCs at the time of3hours after the establishment of SCII model)and HIF-1α-BMSCs group (intrathecal injection of1×106/5ul HIF-1α-BMSCs at the timeof3hours after the establishment of SCII model). Observe the rat’s neurobehavioral scoreby using BBB score3days after operation, then sacrificed the rats, and remove the spinalcord tissue. Finally, use HE staining to observe the pathological changes of spinal cordtissue. Use immunohistochemistry and Western-blot to observe the HIF-1α levels of spinalcord tissue.Results:（1） The BBB score of HIF-1α-BMSCs group was higher than the other groups(P<0.05). （2） Pathologicalobservation of HE staining showed that in SCII group, the spinal cordtissue appeared edema and cell shrinkage. BMSCs group had less edema comparedwith SCII group, and Nissl body could be observed. In HIF-1α-BMSCs group,normal cell morphology, clear nucleolous and Nissl body could be watched.（3） Use immunohistochemistry to observe the HIF-1α levels of spinal cord tissue.There were hardly any HIF-1α levels in Sham group. While, in SCII and BMSCsgroups, the expression levels of HIF-1α could be observed. The most obviousexpression levels of HIF-1α were observed in HIF-1α-BMSCs group.（4） Western-blot results showed that there were also hardly any HIF-1α protein levelsin Sham group, and the most obvious expression levels of HIF-1α were observedin HIF-1α-BMSCs group(P<0.05).Conclude:Intrathecal injection of HIF-1α-BMSCs could have therapy or protection effects inrats which were hurt by SCII. Intrathecal injection of HIF-1α-BMSCs could have promotethe expression level of HIF-1α in myeloid tissue, and thus reduce the rat SCII.