共查询到18条相似文献,搜索用时 234 毫秒
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昆虫干细胞研究进展 总被引:1,自引:1,他引:0
干细胞是一类具有自我更新和分化潜能的细胞,按照其来源可分为胚胎干细胞和成年干细胞。昆虫中也同样存在多种干细胞。开展昆虫干细胞自我更新、发育命运决定、分化潜能等特性以及其与周围微环境相互关系的研究,对农林害虫的生物防治、经济昆虫的遗传育种以及一些生物反应器材料的利用,甚至对于人类疾病的治疗等都具有重要意义。以模式生物果蝇为主,介绍了昆虫干细胞的相关研究进展,重点集中在果蝇各种组织干细胞的鉴定与识别方面,包括研究较成熟的生殖腺内干细胞、中肠干细胞、马氏管干细胞、神经母细胞和造血干细胞。同时介绍了对干细胞维持起重要调控作用的各种信号途径的研究进展。这些昆虫干细胞的研究成果将为开展家蚕等鳞翅目昆虫的干细胞研究提供启示。 相似文献
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动物肠道生理活动受到各级神经系统及体液的调控,特别是依赖于肠神经系统的调控作用.肠神经包括肌间神经丛和粘膜下神经丛,其各类神经元可通过多种神经递质的相互作用来调节肠道的分泌和运动.论文就脊椎动物肠道中几种主要的神经递质的分布及功能作一简要论述,以期为进一步探讨肠神经系统调节机制及脊椎动物肠道疾病的研究提供基础性资料. 相似文献
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胚胎干细胞向神经细胞定向诱导分化方法的研究进展 总被引:2,自引:0,他引:2
胚胎干细胞具有自我更新和多向分化潜能,有望成为治疗神经系统疾病重要的种子细胞来源。如何高效地诱导胚胎干细胞向特定神经细胞分化是目前研究的热点。本文就胚胎干细胞定向分化成神经细胞的3种方法:RA诱导法、谱系选择法和SDIA法及其移植研究做一综述。 相似文献
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神经干细胞研究进展及其在环境兽医学中的应用 总被引:1,自引:0,他引:1
1992年,Reynolds等最先从成年鼠的纹状体和海马中分离出能够进行自我更新、不断分裂增殖且具有多种分化潜能细胞群落,由此提出了神经干细胞(neural stem cells,NSCs)的概念,从而打破了多年来人们一直信为中枢神经细胞是在胚胎时期产生的,成年以后神经细胞的数目不再增加,只会因衰老而发生死亡的论断。Mckay于1997年在Science杂志上将神经干细胞的概念总结为:具有分化为神经元、星形胶质细胞及少突胶质细胞的能力,能自我更新并足以提供大量脑组织细胞的细胞。总之,正因为干细胞具有自我更新能力、多能性或全能性、整合性和转分化性、低免疫原性等特性,所以有着非常重要的理论研究意义和临床应用价值。 相似文献
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本研究旨在优化组织培养法分离小鼠脂肪间充质干细胞(adipose-derived stem cells,ASCs),为研究成骨分化和成脂分化在间充质干细胞分化过程中的相互影响奠定基础。通过细胞形态学观察、细胞生长曲线和流式仪器检测所分离获得的间充质干细胞的特性,利用CRISPR-dCas9系统在快速促进间充质干细胞成骨分化的前提下观察其对成脂分化的影响,并通过生化染色、实时荧光定量PCR和免疫细胞学等手段进行分析。结果显示,接种3~5 d后可见细胞从组织块周围爬出,光镜下可见细胞形态多为成纤维细胞样的梭形细胞,且形态单一均匀,具有较高的爬出率,可以大大提高脂肪间充质干细胞的分离效率;通过CRISPR-dCas9系统激活Runx2和Osterix基因后可以促进间充质干细胞的成骨分化,实时荧光定量PCR及油红O染色结果显示,CRISPR-dCas9系统可以同时抑制间充质干细胞的成脂分化;通过CRISPR-dCas9-KRAB系统同时抑制成骨相关基因Runx2和Osterix后可以促进成脂分化。本研究利用组织贴壁法成功获得了高纯度的脂肪间充质干细胞,具有间充质干细胞的特性和分化能力;利用CRISPR系统可以同时过表达Runx2和Osterix两个基因,可以在进成骨分化的同时抑制成脂分化,表明成脂分化和成骨分化的相关性,为基因编辑在间充质干细胞诱导分化和临床应用方面提供了新的思路和方法。 相似文献
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神经干细胞是一类具有自我复制、自我更新能力,高度增殖和多种分化潜能的神经前体细胞.为了进一步了解神经干细胞的特性,探求神经系统疾病治疗的新途径,文章参阅国内外相关文献,重点介绍了神经干细胞的分布、纯化培养的方法、增殖和分化的影响因素、应用及目前存在的问题等. 相似文献
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New Insights into the Neural Differentiation Potential of Canine Adipose Tissue‐Derived Mesenchymal Stem Cells
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D. Blecker M. I. Elashry M. Heimann S. Wenisch S. Arnhold 《Anatomia, histologia, embryologia》2017,46(3):304-315
Adipose tissue‐derived stem cells (ASCs) can be obtained from different adipose tissue sources within the body. It is an abundant cell pool, easily accessible, suitable for cultivation and expansion in vitro and preparation for therapeutic approaches. Amongst these therapeutic approaches are tissue engineering and nervous system disorders such as spinal cord injuries. For such treatment, ASCs have to be reliably differentiated in to the neuronal direction. Therefore, we investigated the neural differentiation potential of ASCs using protocols with neurogenic inductors such as valproic acid and forskolin, while dog brain tissue served as control. Morphological changes could already be noticed 1 h after neuronal induction. Gene expression analysis revealed that the neuronal markers nestin and βIII‐tubulin as well as MAP2 were expressed after induction of neuronal differentiation. Additionally, the expression of the neurotrophic factors NGF, BDNF and GDNF was determined. Some of the neuronal markers and neurotrophic factors were already expressed in undifferentiated cells. Our findings point out that ASCs can reliably be differentiated into the neuronal lineage; therefore, these cells are a suitable cell source for cell transplantation in disorders of the central nervous system. Follow‐up studies would show the clinical benefit of these cells after transplantation. 相似文献
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K S Kang J E Park D Y Ryu Y S Lee 《The Journal of veterinary medical science / the Japanese Society of Veterinary Science》2001,63(11):1183-1190
Endocrine disrupters are exogenous compounds thought to mimic the action of estrogen or other hormones and influence endocrine activity in the body (Juberg, 2000). These chemicals have adverse effects not only in the reproductive system but also in the central nervous system during development and throughout life. Polychlorinated biphenyls (PCBs) are a class of environmentally persistent and widespread halogenated hydrocarbons. It has been reported that PCBs are potential neurotoxicants. Endosulfan is an organochlorine insecticide that is extensively used to control pests in vegetables, cotton, and fruits. To determine the effect of 2, 2', 4, 4', 5, 5',-hexachlorobiphenyl(2, 4, 5-HCB) and endosulfan on embryo nervous system, we isolated neural stem cells from rat brain at embryonic day 17. Isolated neural stem cells showed pluripotenty. Stem cells could differentiate into neurons and glia. Neurite formation in endosulfan and 2, 4, 5-HCB treated cells. And it appeared to be decreased as compared with that in untreated cells. In order to know the neuro-toxic mechanisms of 2, 4, 5-HCB and endosulfan in neuronal stem cells, we investigated mitogen-activated protein kinase activity (MAPK) and gap junctional intercellular communication (GJIC). Endosulfan decreased the MAPK activity in dose dependent manner. Endosulfan and 2, 4, 5-HCB inhibited GJIC compared to the untreated cell by scrape loading dye transfer (SL/DT). 2, 4, 5-HCB and endosulfan decreased the expression of connexin 43 in dose dependent manner. These results indicated that 2, 4, 5-HCB and endosulfan may inhibit differentiation and proliferation of neural stem cells and gap junctional intercellular communication which play a crucial role in the maintenance of cellular homeostasis. 相似文献
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Bone Marrow Mesenchymal Stem Cells: From Characterization of Neural Differentiation to a Possible Therapeutic Use in Neurodegeneration 总被引:1,自引:0,他引:1
Bone marrow derived stromal cells are of mesenchymal origin and precursor cells for skeletal tissue components such as chondroblasts and osteoblasts. Furthermore, under experimental conditions, a differentiation potency into myogenic and neuronal cells could be demonstrated. Because of their multipotency these cells represent a population of non-haematogen stem cells that can be regarded as an alternative to human embryonic stem cells for future autologous cell replacement therapies. For a closer look at the differentiation capacity of these cells, rat and human bone marrow stromal cells were isolated from the femur bone and kept in the cell culture applying different cultivation protocols. In a cultivation medium with a serum content of 20%, the majority of these cells express a variety of neuronal markers such as ß-III Tubulin and NeuN as well as the astrocyte marker GFAP, while a minority of about 20% express the marker for neural precursor cells nestin. Cultivation in a chemically defined serum free medium results in the differentiation of a markedly higher percentage of nestin positive neural precursor-like cells. Using bFGF in combination with B27 these cells can be forced to form three dimensionally organized spheres. In order to elucidate a possible therapeutical potency of the bone marrow derived cells the synthesis of neurotrophic factors such as BDNF and NGF were analysed using the ELISA technique. Furthermore, they can be infected using a third generation adenoviral vector with high efficiency and show migratory activity in vitro . After injection of bone marrow derived mesenchymal stem cells into the lateral ventricle of adult rats they adhere to the ependymocytes and pass the ependymal barrier in order to settle in the subventricular space. 相似文献
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Earlier observations in neuroscience suggested that no new neurons form in the mature central nervous system. Evidence now indicates that new neurons do form in the adult mammalian brain. Two regions of the mature mammalian brain generate new neurons: (a) the border of the lateral ventricles of the brain (subventricular zone) and (b) the subgranular zone (SGZ) of the dentate gyrus of the hippocampus. This review focuses only on new neuron formation in the dentate gyrus of the hippocampus. During normal prenatal and early postnatal development, neural stem cells (NSCs) give rise to differentiated neurons. NSCs persist in the dentate gyrus SGZ, undergoing cell division, with some daughter cells differentiating into functional neurons that participate in learning and memory and general cognition through integration into pre-existing neural networks. Axons, which emanate from neurons in the entorhinal cortex, synapse with dendrites of the granule cells (small neurons) of the dentate gyrus. Axons from granule cells synapse with pyramidal cells in the hippocampal CA3 region, which send axons to synapse with CA1 hippocampal pyramidal cells that send their axons out of the hippocampus proper. Adult neurogenesis includes proliferation, differentiation, migration, the death of some newly formed cells and final integration of surviving cells into neural networks. We summarise these processes in adult mammalian hippocampal neurogenesis and discuss the roles of major signalling molecules that influence neurogenesis, including neurotransmitters and some hormones. The recent controversy raised concerning whether or not adult neurogenesis occurs in humans also is discussed. 相似文献
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Role of gap junctional intercellular communication (GJIC) through p38 and ERK1/2 pathway in the differentiation of rat neuronal stem cells 总被引:4,自引:0,他引:4
Yang SR Cho SD Ahn NS Jung JW Park JS Jo EH Hwang JW Jung JY Kim TY Yoon BS Lee BH Kang KS Lee YS 《The Journal of veterinary medical science / the Japanese Society of Veterinary Science》2005,67(3):291-294
Gap junctional intercellular communications (GJIC) contributes to neural function in development and differentiation of CNS. In this study, we have investigated the expression of GJIC during the differentiation of neuronal stem cells and 12-O-tetradecanoylphorbol-13-acetate (TPA)-induced neuronal stem cell-derived cells from rat brain. During neuronal stem cell differentiation, expressions of Cx43 and 32 were increased for the duration of 72 hr, however the effect were decreased on the 7d. In the neuronal stem cell-derived cells, pretreatments with p38 MAP kinase inhibitor, SB203580, and MEK inhibitor, PD98059, could protect GJIC against TPA-induced inhibition of GJIC. Our data suggest that GJIC plays an important role during neuronal stem cell differentiation, and ERK1/2 and p38 MAP kinase signaling pathway may be closely related functionally to regulate gap junction in rat neuronal stem cell-derived cells. 相似文献