Objective: To investigate the effect of nano hydroxyapatite/collagen (nHA/collagen) composite as a graft extender and enhancer when combined with recombinant human bone morphogenetic protein 2 (rhBMP 2) on lumbar inte...Objective: To investigate the effect of nano hydroxyapatite/collagen (nHA/collagen) composite as a graft extender and enhancer when combined with recombinant human bone morphogenetic protein 2 (rhBMP 2) on lumbar intertransverse fusion in rabbits. Methods: Sixty four adult female New Zealand white rabbits, aged 1 year and weighing 3.5 4.5 kg, underwent similar posterolateral intertransverse process arthrodesis and were randomly divided into 4 groups based on different grafts: autogenous cancellous bone alone (ACB group), nHA/collagen alone (HAC group), half autogenous cancellous bone and half nHA/collagen (ACB+HAC group) and nHA/collagen combined with rhBMP 2 (HAC+BMP group). The fusion masses were analyzed by manual palpation, radiography, biomechanical testing and histological examination. Results: Fusion was observed in 4 cases in the 6th week and in 5 cases in the 10th week after surgery in ACB group. No case showed fusion in HAC group. In ACB+HAC group, there was fusion in 3 cases in the 6th week and in 4 cases in the 10th week after surgery. In HAC+BMP group, fusion in 1 case was found in the 4th week, in 5 cases in the 6th week and in 6 cases in the 10th week after surgery. It suggested that ACB, ACB+HAC and HAC+BMP groups showed similar fusion ratio and mechanical strength in the 6th and 10th week after surgery. According to the microstructure analysis of the samples, nHA/collagen had no negative effect when implanted together with ilium autograft. In HAC+BMP group, new bone like tissue was observed in the 2nd week postoperatively, and nearly all of the implanted composites were replaced by mature bone matrix and new bones in 10th week postoperatively. Conclusions: The nHA/collagen, especially combined with rhBMP 2, is a promising bone substitute, for it has quick biodegradation, fine bone bending ability, and high osteoconductivity on posterolateral spinal fusion in rabbits.展开更多
Our preliminary proteomics analysis suggested that expression of microtubule-associated protein tau is elevated in the spinal cord after injury. Therefore, the first aim of the present study was to examine tau express...Our preliminary proteomics analysis suggested that expression of microtubule-associated protein tau is elevated in the spinal cord after injury. Therefore, the first aim of the present study was to examine tau expression in the injured spinal cord. The second aim was to determine whether tau can regulate neural stem cell migration, a critical factor in the successful treatment of spinal cord injury. We established rat models of spinal cord injury and injected them with mouse hippocampal neural stem cells through the tail vein. We used immunohistochemistry to show that the expression of tau protein and the number of migrated neural stem cells were markedly increased in the injured spinal cord. Furthermore, using a Transwell assay, we showed that neural stem cell migration was not affected by an elevated tau concentration in the outer chamber, but it was decreased by changes in intracellular tau phosphorylation state. These results demonstrate that neural stem cells have targeted migration capability at the site of injury, and that although tau is not a chemokine for targeted migration of neural stem cells, intracellular tau phosphorylation/dephosphorylation can inhibit cell migration.展开更多
Reducing the secondary inflammatory response, which is partly mediated by microglia, is a key focus in the treatment of spinal cord injury. Src homology 2-containing protein tyrosine phosphatase 2(SHP2), encoded by PT...Reducing the secondary inflammatory response, which is partly mediated by microglia, is a key focus in the treatment of spinal cord injury. Src homology 2-containing protein tyrosine phosphatase 2(SHP2), encoded by PTPN11, is widely expressed in the human body and plays a role in inflammation through various mechanisms. Therefore, SHP2 is considered a potential target for the treatment of inflammation-related diseases. However, its role in secondary inflammation after spinal cord injury remains unclear. In this study, SHP2 was found to be abundantly expressed in microglia at the site of spinal cord injury. Inhibition of SHP2 expression using siRNA and SHP2 inhibitors attenuated the microglial inflammatory response in an in vitro lipopolysaccharide-induced model of inflammation. Notably, after treatment with SHP2 inhibitors, mice with spinal cord injury exhibited significantly improved hind limb locomotor function and reduced residual urine volume in the bladder. Subsequent in vitro experiments showed that, in microglia stimulated with lipopolysaccharide, inhibiting SHP2 expression promoted M2 polarization and inhibited M1 polarization. Finally, a co-culture experiment was conducted to assess the effect of microglia treated with SHP2 inhibitors on neuronal cells. The results demonstrated that inflammatory factors produced by microglia promoted neuronal apoptosis, while inhibiting SHP2 expression mitigated these effects. Collectively, our findings suggest that SHP2 enhances secondary inflammation and neuronal damage subsequent to spinal cord injury by modulating microglial phenotype. Therefore, inhibiting SHP2 alleviates the inflammatory response in mice with spinal cord injury and promotes functional recovery postinjury.展开更多
Microtubule-associated protein 1B plays an important role in axon guidance and neuronal migration. In the present study, we sought to discover the mechanisms underlying microtu- bule-associated protein 1B mediation of...Microtubule-associated protein 1B plays an important role in axon guidance and neuronal migration. In the present study, we sought to discover the mechanisms underlying microtu- bule-associated protein 1B mediation of axon guidance and neuronal migration. We exposed bone marrow mesenchymal stem cells to okadaic acid or N-acetyl-D-erythro-sphingosine （an inhibitor and stimulator, respectively, of protein phosphatase 2A） for 24 hours. The expression of the phosphorylated form of type I microtubule-associated protein 1B in the cells was greater after exposure to okadaic acid and lower after N-acetyl-D-erythro-sphingosine. We then injected the bone marrow mesenchymal stem cells through the ear vein into rabbit models of spinal cord contusion. The migration of bone marrow mesenchymal stem cells towards the injured spinal cord was poorer in cells exposed to okadaic acid- and N-acetyl-D-erythro-sphingosine than in non-treated bone marrow mesenchymal stem cells. Finally, we blocked phosphatidylinosi- tol 3-kinase （PI3K） and extracellular signal-regulated kinase 1/2 （ERK1/2） pathways in rabbit bone marrow mesenchymal stem cells using the inhibitors LY294002 and U0126, respectively. LY294002 resulted in an elevated expression of phosphorylated type I microtubule-associated protein 1B, whereas U0126 caused a reduction in expression. The present data indicate that PI3K and ERKI/2 in bone marrow mesenchymal stem cells modulate the phosphorylation of micro- tubule-associated protein 1B via a cross-signaling network, and affect the migratory efficiency of bone marrow mesenchymal stem cells towards injured spinal cord.展开更多
Post-translational modifications of cellular proteins with ubiquitin or ubiquitin-like proteins regulate many cellular processes,such as cell proliferation,differentiation,apoptosis, signal transduction,intercellular ...Post-translational modifications of cellular proteins with ubiquitin or ubiquitin-like proteins regulate many cellular processes,such as cell proliferation,differentiation,apoptosis, signal transduction,intercellular immune recognition,inflammatory response,stress response,and DNA repair.Nice4/UBAP2L is an important member in the family of ubiquitin-like proteins,and its biological function remains unknown.This study aimed to investigate the effect of UBAP2L on spinal cord injury (SCI).At first,rat bone marrow mesenchymal stem cells (BMSCs)were infected with adeno-associated virus to induce over-expression of Nice4.Subsequently,the infected BMSCs were transplanted into rats suffering from semi-sectioned SCI.The results showed that the over-expression of Nice4 significantly promoted the proliferation and differentiation of BMSCs. In addition,the transplantation of infected BMSCs into the injured area of SCI rats improved the function repair of SCI.Importantly,the immunohistochemical and hematoxylin-eosin staining and RT-PCR results showed that the number of neuronal cells,oligodendrocytes,and astrocytes was significantly increased in the injured area,along with significantly upregulated expression ofcyclin D1 and p38 mitogen-activated protein kinase (MAPK).Meanwhile,the expression of caspase 3 protein was significantly down-regulated.In conclusion,the over-expression of Nice4 gene can promote the functional recovery in SCI rats by promoting cell proliferation and inhibiting apoptosis. The results of this study indicate an alternative option for the clinical treatment of SCI.展开更多
Tanshinone lla is an effective monomer component of Danshen, which is a traditional Chinese medicine for activating blood circulation to dissipate blood stasis. Tanshinone Ila can effectively improve brain tissue isch...Tanshinone lla is an effective monomer component of Danshen, which is a traditional Chinese medicine for activating blood circulation to dissipate blood stasis. Tanshinone Ila can effectively improve brain tissue ischemia/hypoxia injury. The present study established a rat model of spinal cord ischemia/reperfusion injury and intraperitoneally injected Tanshinone lla, 0.5 hour prior to model establishment. Results showed that Tanshinone Ila promoted heat shock protein 70 and Bcl-2 protein expression, but inhibited Bax protein expression in the injured spinal cord after ischemia/reperfusion injury. Furthermore, Nissl staining indicated a reduction in nerve cell apoptosis and fewer pathological lesions in the presence of Tanshinone Ila, compared with positive control Danshen injection.展开更多
目的分析脊髓压迫性损伤(compressed spinal cord injury,CSCI)后脱髓鞘病变与髓鞘碱性蛋白(myelinbasic protein,MBP)、DNA结合抑制物2(inhibitor of DNA binding2,Id2)的表达变化之间的关系,以探讨CSCI脱髓鞘病变机制。方法采用自行...目的分析脊髓压迫性损伤(compressed spinal cord injury,CSCI)后脱髓鞘病变与髓鞘碱性蛋白(myelinbasic protein,MBP)、DNA结合抑制物2(inhibitor of DNA binding2,Id2)的表达变化之间的关系,以探讨CSCI脱髓鞘病变机制。方法采用自行设计的方法制作SD大鼠CSCI模型,通过锇酸染色检测CSCI后1、3、7 d有髓神经纤维变化;运用免疫荧光双标和免疫印迹(Western blot)检测MBP及Id2的表达变化。结果 CSCI后出现脱髓鞘病变,并随着压迫时间延长,髓鞘逐渐发生水肿、变性、崩解;脊髓损伤后MBP表达下调,其表达趋势与脱髓鞘溃变的严重程度一致;CSCI后,Id2广泛分布于白质,随着压迫时间延长,其表达逐渐上调。结论 Id2表达上调,并负向调控MBP基因启动子的活性,使MBP的表达下降,是CSCI后神经纤维脱髓鞘病变的机制之一。展开更多
文摘Objective: To investigate the effect of nano hydroxyapatite/collagen (nHA/collagen) composite as a graft extender and enhancer when combined with recombinant human bone morphogenetic protein 2 (rhBMP 2) on lumbar intertransverse fusion in rabbits. Methods: Sixty four adult female New Zealand white rabbits, aged 1 year and weighing 3.5 4.5 kg, underwent similar posterolateral intertransverse process arthrodesis and were randomly divided into 4 groups based on different grafts: autogenous cancellous bone alone (ACB group), nHA/collagen alone (HAC group), half autogenous cancellous bone and half nHA/collagen (ACB+HAC group) and nHA/collagen combined with rhBMP 2 (HAC+BMP group). The fusion masses were analyzed by manual palpation, radiography, biomechanical testing and histological examination. Results: Fusion was observed in 4 cases in the 6th week and in 5 cases in the 10th week after surgery in ACB group. No case showed fusion in HAC group. In ACB+HAC group, there was fusion in 3 cases in the 6th week and in 4 cases in the 10th week after surgery. In HAC+BMP group, fusion in 1 case was found in the 4th week, in 5 cases in the 6th week and in 6 cases in the 10th week after surgery. It suggested that ACB, ACB+HAC and HAC+BMP groups showed similar fusion ratio and mechanical strength in the 6th and 10th week after surgery. According to the microstructure analysis of the samples, nHA/collagen had no negative effect when implanted together with ilium autograft. In HAC+BMP group, new bone like tissue was observed in the 2nd week postoperatively, and nearly all of the implanted composites were replaced by mature bone matrix and new bones in 10th week postoperatively. Conclusions: The nHA/collagen, especially combined with rhBMP 2, is a promising bone substitute, for it has quick biodegradation, fine bone bending ability, and high osteoconductivity on posterolateral spinal fusion in rabbits.
基金supported by the National Natural Science Foundation of China,No.81250016,31572217
文摘Our preliminary proteomics analysis suggested that expression of microtubule-associated protein tau is elevated in the spinal cord after injury. Therefore, the first aim of the present study was to examine tau expression in the injured spinal cord. The second aim was to determine whether tau can regulate neural stem cell migration, a critical factor in the successful treatment of spinal cord injury. We established rat models of spinal cord injury and injected them with mouse hippocampal neural stem cells through the tail vein. We used immunohistochemistry to show that the expression of tau protein and the number of migrated neural stem cells were markedly increased in the injured spinal cord. Furthermore, using a Transwell assay, we showed that neural stem cell migration was not affected by an elevated tau concentration in the outer chamber, but it was decreased by changes in intracellular tau phosphorylation state. These results demonstrate that neural stem cells have targeted migration capability at the site of injury, and that although tau is not a chemokine for targeted migration of neural stem cells, intracellular tau phosphorylation/dephosphorylation can inhibit cell migration.
基金supported by the Natural Science Research Project of Anhui Province University, No.2023AH040394 (to TY)Hefei Comprehensive National Science Center Leading Medicine and Frontier Technology Research Institute Project, No.2023IHM01073 (to TY)the Natural Science Foundation of Anhui Province, Nos.2308085QH258 (to JW), 2008085MH246 (to TY)。
文摘Reducing the secondary inflammatory response, which is partly mediated by microglia, is a key focus in the treatment of spinal cord injury. Src homology 2-containing protein tyrosine phosphatase 2(SHP2), encoded by PTPN11, is widely expressed in the human body and plays a role in inflammation through various mechanisms. Therefore, SHP2 is considered a potential target for the treatment of inflammation-related diseases. However, its role in secondary inflammation after spinal cord injury remains unclear. In this study, SHP2 was found to be abundantly expressed in microglia at the site of spinal cord injury. Inhibition of SHP2 expression using siRNA and SHP2 inhibitors attenuated the microglial inflammatory response in an in vitro lipopolysaccharide-induced model of inflammation. Notably, after treatment with SHP2 inhibitors, mice with spinal cord injury exhibited significantly improved hind limb locomotor function and reduced residual urine volume in the bladder. Subsequent in vitro experiments showed that, in microglia stimulated with lipopolysaccharide, inhibiting SHP2 expression promoted M2 polarization and inhibited M1 polarization. Finally, a co-culture experiment was conducted to assess the effect of microglia treated with SHP2 inhibitors on neuronal cells. The results demonstrated that inflammatory factors produced by microglia promoted neuronal apoptosis, while inhibiting SHP2 expression mitigated these effects. Collectively, our findings suggest that SHP2 enhances secondary inflammation and neuronal damage subsequent to spinal cord injury by modulating microglial phenotype. Therefore, inhibiting SHP2 alleviates the inflammatory response in mice with spinal cord injury and promotes functional recovery postinjury.
基金supported by the National Natural Science Foundation of China,No.81350013,81250016the Youth Science Project of National Natural Science Foundation of China,No.81301289the Youth Scientific Research Project of Jilin Provincial Science and Technology Development Plan,No.20130522032JH,20130522039JH
文摘Microtubule-associated protein 1B plays an important role in axon guidance and neuronal migration. In the present study, we sought to discover the mechanisms underlying microtu- bule-associated protein 1B mediation of axon guidance and neuronal migration. We exposed bone marrow mesenchymal stem cells to okadaic acid or N-acetyl-D-erythro-sphingosine （an inhibitor and stimulator, respectively, of protein phosphatase 2A） for 24 hours. The expression of the phosphorylated form of type I microtubule-associated protein 1B in the cells was greater after exposure to okadaic acid and lower after N-acetyl-D-erythro-sphingosine. We then injected the bone marrow mesenchymal stem cells through the ear vein into rabbit models of spinal cord contusion. The migration of bone marrow mesenchymal stem cells towards the injured spinal cord was poorer in cells exposed to okadaic acid- and N-acetyl-D-erythro-sphingosine than in non-treated bone marrow mesenchymal stem cells. Finally, we blocked phosphatidylinosi- tol 3-kinase （PI3K） and extracellular signal-regulated kinase 1/2 （ERK1/2） pathways in rabbit bone marrow mesenchymal stem cells using the inhibitors LY294002 and U0126, respectively. LY294002 resulted in an elevated expression of phosphorylated type I microtubule-associated protein 1B, whereas U0126 caused a reduction in expression. The present data indicate that PI3K and ERKI/2 in bone marrow mesenchymal stem cells modulate the phosphorylation of micro- tubule-associated protein 1B via a cross-signaling network, and affect the migratory efficiency of bone marrow mesenchymal stem cells towards injured spinal cord.
基金the National Natural Science Foundation of China(No.81271347).
文摘Post-translational modifications of cellular proteins with ubiquitin or ubiquitin-like proteins regulate many cellular processes,such as cell proliferation,differentiation,apoptosis, signal transduction,intercellular immune recognition,inflammatory response,stress response,and DNA repair.Nice4/UBAP2L is an important member in the family of ubiquitin-like proteins,and its biological function remains unknown.This study aimed to investigate the effect of UBAP2L on spinal cord injury (SCI).At first,rat bone marrow mesenchymal stem cells (BMSCs)were infected with adeno-associated virus to induce over-expression of Nice4.Subsequently,the infected BMSCs were transplanted into rats suffering from semi-sectioned SCI.The results showed that the over-expression of Nice4 significantly promoted the proliferation and differentiation of BMSCs. In addition,the transplantation of infected BMSCs into the injured area of SCI rats improved the function repair of SCI.Importantly,the immunohistochemical and hematoxylin-eosin staining and RT-PCR results showed that the number of neuronal cells,oligodendrocytes,and astrocytes was significantly increased in the injured area,along with significantly upregulated expression ofcyclin D1 and p38 mitogen-activated protein kinase (MAPK).Meanwhile,the expression of caspase 3 protein was significantly down-regulated.In conclusion,the over-expression of Nice4 gene can promote the functional recovery in SCI rats by promoting cell proliferation and inhibiting apoptosis. The results of this study indicate an alternative option for the clinical treatment of SCI.
基金supported by the National Natural Science Foundation of China,No.30973765New Century Excellent Talents Program,No. NECT-09-0013the Foundationfor Doctors,Ministry of Education,No.20113519110001
文摘Tanshinone lla is an effective monomer component of Danshen, which is a traditional Chinese medicine for activating blood circulation to dissipate blood stasis. Tanshinone Ila can effectively improve brain tissue ischemia/hypoxia injury. The present study established a rat model of spinal cord ischemia/reperfusion injury and intraperitoneally injected Tanshinone lla, 0.5 hour prior to model establishment. Results showed that Tanshinone Ila promoted heat shock protein 70 and Bcl-2 protein expression, but inhibited Bax protein expression in the injured spinal cord after ischemia/reperfusion injury. Furthermore, Nissl staining indicated a reduction in nerve cell apoptosis and fewer pathological lesions in the presence of Tanshinone Ila, compared with positive control Danshen injection.
