人脊髓前角运动神经元190KD蛋白的初步研究

本研究采用ＳＤＳ凝胶电泳方法从人脊神经前根中分离出人脊髓前角运动神经元特有的蛋白—１９０ＫＤ。将该蛋白作为抗原,免疫ＢＡＬＢ／ｃ小鼠,经杂交瘤技术,获得了抗１９０ＫＤ蛋白的单克隆抗体。免疫细胞化学检测表明,１９０ＫＤ单抗与脊髓灰质前角神经元、前根及肌支发生阳性反应。实验结果提示,１９０ＫＤ蛋白分布在脊髓运动神经元胞体及脊神经的前根和肌支纤维中。     

Transplanted neural progenitor cells expressing mutant NT3 promote myelination and partial hindlimb recovery in the chronic phase after spinal cord injury

Neutrotrophin-3 (NT3) plays a protective role in injured central nervous system tissues through interaction with trk receptors. To enhance the regeneration of damaged tissue, a combination therapy with cell transplantation and neurotrophins has been under development. We examined whether the transplantation of neural progenitor cells (NPCs) secreting NT3/D15A, a multi-neurotrophin with the capacity to bind both trkB and trkC, would enhance the repair of damaged tissues and the functional recovery in a chronic phase of spinal cord injury. The cultured NPCs with lentiviral vector containing either GFP or NT3/D15A were transplanted into the contused spinal cord at 6 weeks after the initial thoracic injury. Eight weeks after the transplantation, the NT3/D15A transplants displayed better survival than the GFP transplants, and they exhibited enhanced myelin formation and partial improvement of hindlimb function. Our study revealed that NT3/D15A produced positive effects in injured spinal cords even in the chronic phase. These effects suggest an enhanced neurotrophin-trk signaling by NT3/D15A.     

Immobilization and bone structure in humans

Long-term immobilization is known to result in substantial bone loss. The present review examined the existing evidence for deterioration of bone structure during long-term disuse in humans. Paralysis due to spinal cord injury, long-term exposure to microgravity in space or tightly restricted mobility during bed rest provide reasonable models to assess the influence of immobilization on bone structure. Expectedly, the duration of immobilisation was the major determinant of bone loss, but irrespective of whether the skeletal unloading was due to irrecoverable paralysis, long-term spaceflight or bed rest, the mean pattern of structural deterioration of bone, mainly manifest as substantial cortical thinning and trabecular bone loss, was quite similar. However, skeletal responses to disuse can be highly variable between individuals. Apparently the relative decline in individual’s bone loading in relation to loading prior to immobilization accounts for inter-individual variation.     

A neurobiological model of the recovery strategies from perturbed walking

This paper proposes a human mimetic neuro-musculo-skeletal model to simulate the recovery reactions from perturbations during walking. The computational model incorporates nonlinear viscoelastic muscular mechanics, supraspinal control of the center-of-mass, spinal pattern generator including muscle synergy network, spinal reflexes, and long-loop reflexes. Especially the long-loop reflexes specify recovery strategies based on the experimental observations [Schillings, A.M., van Wezel, B.M.H., Mulder, T.H., Duysen, J., 2000. Muscular responses and movement strategies during stumbling over obstacles. J. Neurophysiol. 83, 2093–2102; Eng, J.J., Winter, D.A., Patla, A.E., 1994. Strategies for recovery from a trip in early and late swing during human walking. Exp. Brain Res. 102, 339–349]. The model demonstrates two typical recovery strategies, i.e., elevating and lowering strategies against pulling over a swing leg. Sensed perturbation triggers a simple tonic pulse from the cortex. Depending on the swing phase, the tonic pulse activates a different compound of muscles over lower limbs. The compound induces corresponding recovery strategies. The reproduction of principal recovery behaviors may support the model's proposed functional and/or anatomical correspondence.     

A novel approach for myocardial regeneration with educated cord blood cells cocultured with cells from brown adipose tissue

Umbilical cord blood (CB) is a promising source for regeneration therapy in humans. Recently, it was shown that CB was a source of mesenchymal stem cells as well as hematopoietic stem cells, and further that the mesenchymal stem cells could differentiate into a number of cells types of mesenchymal lineage, such as cardiomyocytes (CMs), osteocytes, chondrocytes, and fat cells. Previously, we reported that brown adipose tissue derived cells (BATDCs) differentiated into CMs and these CMs could adapt functionally to repair regions of myocardial infarction. In this study, we examined whether CB mononuclear cells (CBMNCs) could effectively differentiate into CMs by coculturing them with BATDCs and determined which population among CBMNCs differentiated into CMs. The results show that BATDCs effectively induced CBMNCs that were non-hematopoietic stem cells (HSCs) (educated CB cells: e-CBCs) into CMs in vitro. E-CBCs reconstituted infarcted myocardium more effectively than non-educated CBMNCs or CD34-positive HSCs. Moreover, we found that e-CBCs after 3 days coculturing with BATDCs induced the most effective regeneration for impaired CMs. This suggests that e-CBCs have a high potential to differentiate into CMs and that adequate timing of transplantation supports a high efficiency for CM regeneration. This strategy might be a promising therapy for human cardiac disease.     

Human umbilical cord blood serum can replace fetal bovine serum in the culture of mesenchymal stem cells

The potential of mesenchymal stem cells (MSC) to differentiate into different cell types has opened up the possibility of using these cells clinically to treat a variety of disorders. In this study we describe the use of human umbilical cord blood serum (CBS) as a replacement for fetal bovine serum (FBS) for culturing MSC from different sources. MSC from human and swine bone marrow and human umbilical cord blood were cultured in the presence of DMEM/F12 containing either FBS or CBS. Human MSC cultured in presence of FBS or CBS showed typical fibroblast-like morphology, which is characteristic of MSC. 99% of the cells cultured in FBS had a CD73+/CD105+/CD45- phenotype compared to 96% of cells cultured in CBS. Cells cultured in CBS had a significantly higher cell count as compared to cells cultured in FBS. Swine Bone Marrow MSC cultured in the presence of FBS and CBS were morphologically and phenotypically similar. Human umbilical cord blood serum supports the growth of MSC. While no significant differences were observed in the MSC numbers in swine cells cultured in the presence of FBS or CBS, human cells showed a greater proliferation potential in the presence of CBS as compared to FBS. Therefore, CBS can be used as an effective substitute to FBS for developing clinically useful protocols for culturing MSC.     

Review of spino-occipital and spinal nerves in Tetraodontiformes,with special reference to pectoral and pelvic fin muscle innervation

The spino-occipital nerve (SO) and ventral rami of the spinal nerves (SV) in 10 tetraodontiform families and 5 outgroup taxa were examined, with special reference to pectoral and pelvic fin muscle innervation. Compared with the outgroup taxa, tetraodontiforms were characteristic in having SO3 + SV1 (SO3 in tetraodontids) that gave off several lateral subbranches to the pectoral fin base and SO participation in infracarinalis anterior innervation. SO and SV1 were connected with one another (6 patterns) before entering the pectoral fin muscles in most species, including the outgroup taxa, resulting in the participation of SV1 in the innervation of almost all of the pectoral fin muscles. SO3 + SV1 was present in all tetraodontiforms (except in 2 tetraodontids having only SO3) and the outgroup taxa, an upper dorsal branch uniformly extending dorsally into the pectoral fin base. The pectoral fin base also received a branch ventrally, but its identity differed (participation or nonparticipation of SV2). SV1 alone constituting the branch was a derived condition occurring in Aracanidae, Ostraciidae, Tetraodontidae, Diodontidae, and Molidae. No strong characters supporting a tetraodontiform sister group were recognized among the spino-occipital nerve and ventral rami of spinal nerves.     

Mesenchymal Stem Cells from Rat Bone Marrow Downregulate Caspase-3-mediated Apoptotic Pathway After Spinal Cord Injury in Rats

Mesenchymal stem cells have been intensively studied for their potential use in reparative strategies for neurodegenerative diseases and traumatic injuries. We used mesenchymal stem cells (rMSC) from rat bone marrow to evaluate the therapeutic potential after spinal cord injury (SCI). Immunohistochemistry confirmed a large number of apoptotic neurons and oligodendrocytes in caudal segments 2 mm away from the lesion site. Expression of caspase-3 on both neurons and oligodendrocytes after SCI was significantly downregulated by rMSC. Caspase-3 downregulation by rMSC involves increased expression of FLIP and XIAP in the cytosol and inhibition of PARP cleavage in the nucleus. Animals treated with rMSC had higher Basso, Beattie, Bresnahan (BBB) locomotor scoring and better recovery of hind limb sensitivity. Treatment with rMSC had a positive effect on behavioral outcome and histopathological assessment after SCI. The ability of rMSC to incorporate into the spinal cord, differentiate and to improve locomotor recovery hold promise for a potential cure after SCI. Special issue in honor of Naren Banik.     

内皮素-1促进反应性星形胶质细胞增殖

目的利用成年SD大鼠脊髓损伤原代培养的反应性星形胶质细胞模型,探讨内皮素-1(ET1)与反应性星形胶质细胞增殖之间的关系。方法建立成年SD大鼠脊髓损伤原代培养的反应性星形胶质细胞模型,用100 n M ET1和5μM BQ788(内皮素受体B的拮抗剂)处理反应性星形胶质细胞48 h,通过免疫荧光的方法对各实验组中星形胶质细胞的标记分子Vimentin及Brdu进行检测,以确定ET1对反应性星形胶质细胞增殖的影响。结果 ET1组中星形胶质细胞的数量明显增加,Brdu阳性细胞占星形胶质细胞的平均百分比(19.41%)高于正常对照组(3.28%,P0.01);而ET1+BQ788组中Brdu阳性细胞数占星形胶质细胞的平均百分比为10.38%,明显低于ET1组(19.41%,P0.01)。结论在成年SD大鼠脊髓损伤原代培养的反应性星形胶质细胞模型中,ET1可刺激反应性星形胶质细胞的增殖,ET1受体endothelin B的拮抗剂BQ788可有效抑制ET1对反应性星形胶质细胞的促增殖效应。