Jun-Bin Lin,Chan-Juan Zheng,Xuan Zhang,Juan Chen,Wei-Jing Liao,Qi Wan
The 2,3,5,6-tetramethylpyrazine (TMP) has been widely used in the treatment of ischemic stroke by Chinese doctors. Here, we report the effects of TMP on functional recovery and dendritic plasticity after ischemic stroke. A classical model of middle cerebral artery occlusion (MCAO) was established in this study. The rats were assigned into 3 groups: sham group (sham operated rats treated with saline), model group (MCAO rats treated with saline) and TMP group (MCAO rats treated with 20 mg/kg/d TMP). The neurological function test of animals was evaluated using the modified neurological severity score (mNSS) at 3 d, 7 d, and 14 d after MCAO. Animals were euthanized for immunohistochemical labeling to measure MAP-2 levels in the peri-infarct area. Golgi-Cox staining was performed to test effect of TMP on dendritic plasticity at 14 d after MCAO. TMP significantly improved neurological function at 7 d and 14 d after ischemia, increased MAP-2 level at 14 d after ischemia, and enhanced spine density of basilar dendrites. TMP failed to affect the spine density of apical dendrites and the total dendritic length. Data analyses indicate that there was significant negative correlation between mNSS and plasticity measured at 14 d after MCAO. Thus, enhanced dendritic plasticity contributes to TMP-elicited functional recovery after ischemic stroke.
Cell-derived extracellular matrix (ECM) has been applied in spinal cord injury (SCI) regeneration because of its various biological functions. However, insufficient mechanical properties limit its wide application. Herein, we developed GelMA/ECM hydrogel fibrous scaffolds (GelMA/ECM scaffolds) that can recruit and enhance the differentiation of neural stem cells (NSCs) by electrospinning and decellularization techniques. Moreover, the GelMA/ECM scaffolds had good mechanical properties and reinforced cell adhesion and proliferation. Compared to GelMA hydrogel fibrous scaffolds (GelMA scaffolds), GelMA/ECM scaffolds promoted more NSCs toward neurons by markedly enhancing the expression of MAP-2 and Tuj-1 and decreasing GFAP expression. In addition, the GelMA/ECM scaffolds significantly reduced the proportion of M1-phenotype macrophages, which is favorable for SCI repair. In vivo, the GelMA/ECM scaffolds recruited NSCs at the injured site, promoted neuron regeneration, and reduced the formation of glial scars and the inflammatory response, which further led to a significant improvement in the functional recovery of SCI. Therefore, this scaffold shows potential in regenerative medicine, mainly in SCI.