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1.
Radiotherapy is the primary treatment for patients with head and neck cancer, which account for roughly 500,000 annual cases worldwide. Dysfunction of the salivary glands and associated conditions like xerostomia and dysphagia are often developed by these patients, greatly diminishing their life quality. Current preventative and palliative care fail to deliver an improvement in the quality of life, thus accentuating the need for regenerative therapies. In this study, a model of label retaining cells (LRCs) in murine salivary glands was developed, in which LRCs demonstrated proliferative potential and possessed markers of putative salivary progenitors. Mice were labeled with 5-Ethynyl-2′-deoxyuridine (EdU) at postnatal day 10 and chased for 8 weeks. Tissue sections from salivary glands obtained at the end of chase demonstrated co-localization between LRCs and the salivary progenitor markers keratin 5 and keratin 14, as well as kit mRNA, indicating that LRCs encompass a heterogeneous population of salivary progenitors. Proliferative potential of LRCs was demonstrated by a sphere assay, in which LRCs were found in primary and secondary spheres and they co-localized with the proliferation marker Ki67 throughout sphere formation. Surprisingly, LRCs were shown to be radio-resistant and evade apoptosis following radiation treatment. The clinical significance of these findings lie in the potential of this model to study the mechanisms that prevent salivary progenitors from maintaining homeostasis upon exposure to radiation, which will in turn facilitate the development of regenerative therapies for salivary gland dysfunction. 相似文献
2.
探讨脑源性神经营养因子(brain derived neurotrophic factor, BDNF)对海马神经干细胞(neural progenitor/stem cells, NPCs)的存活、增殖及分化的影响.采用无血清培养基体外分离、纯化、扩增胎鼠海马NPCs.通过细胞形态观察、nestin免疫荧光染色及血清促分化检测NPCs的干细胞特性; 采用神经球计数及神经球直径测定观察BDNF对NPCs的促增殖作用, 筛选出在适当细胞密度下, 促进NPCs增殖的有效浓度; 采用Tunel染色及全自动生化分析仪测定细胞培养上清液乳酸脱氢酶(lactic dehydrogenase, LDH)的含量探讨BDNF对海马NPCs存活的影响; 采用抗-b-微管蛋白(tubulin) III (Tuj-1)染色检测NPCs分化成神经元的百分率, 同时测定分化神经元突起的长度.分离的海马NPCs表现为nestin 免疫染色阳性, 具有自我增殖能力、且能分化为神经元和星形胶质细胞; 当细胞密度为5×105个/ ml 时, 10~200 ng/ml BDNF能显著促进NPCs的增殖, 其中40 ng/ml BDNF促增殖作用最强, 40 ng/ml BDNF能显著增大神经球直径; 40 ng/ml BDNF 显著减少NPCs的凋亡率(Tunel /DAPI ), 抑制LDH漏出; 40 ng/ml BDNF能显著促进NPCs分化为Tuj-1免疫染色阳性神经元, 且分化后神经元的突起长度显著大于对照组.上述结果提示: BDNF促进海马NPCs的存活、增殖及向神经元方向分化. 相似文献
3.
Aleksandrova M. A. Revishchin A. V. Poltavtseva R. A. Cherkasova L. V. Kleshchinov V. N. Korochkin L. I. Sukhikh G. T. 《Russian Journal of Developmental Biology》2003,34(3):131-136
We studied the development of stem/progenitor cells of the human brain transplanted in the adult rat brain after expansion in an in vitrotissue culture. It was preliminarily shown by the immunological methods that the stem cells grown in a medium with growth factors formed neurospheres, which were heterogenous and contained both stem and progenitor cells of the human brain. The cells were implanted in the hippocampus, striatum, or lateral ventricle of the rat brain as a suspension or aggregates (neurospheres) and their behavior and differentiation were studies within 10, 20, and 30 days using the morphological and immunochemical methods. The cultured cells of the human brain continued their development in the rat brain, migrated, and formed neurons and astrocytes. The white mater fibers, lateral ventricle wall, and perivascular spaces served as the main pathways of migration. The neuronal differentiation was shown by staining with antibodies to -tubulin III, neurofilaments-70, and calbindin. Some growing nerve cells had long processes with growth cones. At the same time, some transplanted cells retained the undifferentiated state within one month after the implantation, as shown by the vimentin expression. 相似文献
4.
Bulken-Hoover JD Jackson WM Ji Y Volger JA Tuan RS Nesti LJ 《Molecular biotechnology》2012,51(2):128-136
Peripheral nerve damage frequently accompanies musculoskeletal trauma and repair of these nerves could be enhanced by the
targeted application of neurotrophic factors (NTFs), which are typically expressed by endogenous cells that support nerve
regeneration. Injured muscle tissues express NTFs to promote reinnervation as the tissue regenerates, but the source of these
factors from within the muscles is not fully understood. We have previously identified a population of mesenchymal progenitor
cells (MPCs) in traumatized muscle tissue with properties that support tissue regeneration, and our hypothesis was that MPCs
also secrete the NTFs that are associated with muscle tissue reinnervation. We determined that MPCs express genes associated
with neurogenic function and measured the protein-level expression of specific NTFs with known functions to support nerve
regeneration. We also demonstrated the effectiveness of a neurotrophic induction protocol to enhance the expression of the
NTFs, which suggests that the expression of these factors may be modulated by the cellular environment. Finally, neurotrophic
induction affected the expression of cell surface markers and proliferation rate of the MPCs. Our findings indicate that traumatized
muscle-derived MPCs may be useful as a therapeutic cell type to enhance peripheral nerve regeneration following musculoskeletal
injury. 相似文献
5.
Lisete Haas Luis V. C. Portela Ana Elisa Böhmer Jean Pierre Oses Diogo R. Lara 《Neurochemical research》2010,35(5):830-834
Brain-derived neurotrophic factor (BDNF) is involved in neuronal survival and synaptic plasticity of the central and peripheral
nervous system. BDNF appears to modulate nociceptive sensory inputs and pain hypersensitivity and has been studied in pathological
situations, including chronic pain conditions and major depression. Increased serum BDNF levels have been recently reported
in fibromyalgia (FM). In the present study, we assessed plasma BDNF levels in patients with FM and controls. Plasma BDNF was
measured from 30 female patients with FM and 30 healthy age- and gender-matched volunteers using an enzyme immunoassay. FM
patients showed higher levels of BDNF (FM = 167.1 ± 171.2 pg/mL) when compared with the control group (control = 113.8 ± 149.6 pg/mL)
(P = 0.049; Mann–Whitney test). Six out of 30 controls presented superior values to the medium (15/15) of the patients with
fibromyalgia (129 pg/mL) (P = 0.029, Fisher exact test). There was no correlation between plasma BDNF levels and age, disease duration, pain score, number
of pain points and HAM-D score. Our results confirm previous findings of increased plasma BDNF levels in patients with FM,
suggesting that BDNF may be involved in the pathophysiology of Fibromyalgia, despite high levels of depression. 相似文献
6.
重组人脑源性神经营养因子在大肠杆菌中的可溶性表达及纯化 总被引:1,自引:0,他引:1
按照人脑源性神经营养因子(hBDNF)基因成熟肽编码序列设计合成引物,从人基因组DNA中扩增出360bp的片段,插入到改构载体pTIG-trx上,获得了pTIG-trx—BDNF原核表达重组质粒,限制性酶切分析和DNA序列测定均证实该克隆插入片段为hBDNF基因成熟肽编码序列。将该重组质粒转化大肠杆菌BL21(DE3),经IPTG诱导表达,在大肠杆菌表达系统中获得了高效可溶表达,并对表达产物进行了分离纯化,得到纯度大于83%的样品,Western杂交证实该蛋白具有hBDNF抗原活性。 相似文献
7.
目的:探讨玻璃体腔内注射移植体外培养的骨髓间充质干细胞(Bone marrow mesenchymal stem cells, BMSCs)对家猫视神经损伤后视网膜神经节细胞(Retinal ganglion cells, RGCs)的影响及其可能的作用机制。方法:参照标准化家猫外伤性视神经损伤动物模型建立的方法建立右眼视神经夹伤家猫模型,然后将其分为以下四组:(1)A组:右眼BMSCs注射移植组,玻璃体腔内接受注射移植BMSCs浓度为1×10~5细胞/μL的单细胞悬液0.1 m L;(2)B组:右眼PBS注射组,玻璃体腔内注射PBS缓冲液0.1 mL;(3)C组:假损伤控制组,BMSCs左眼组,仅暴露视神经而不损伤,不接受治疗;(4)D组:正常对照组,PBS左眼组,正常眼,不做任何处理。分别在移植后的3、7、14及28天,用免疫荧光染色双十八烷基四甲基吲哚羰基花青高氯酸盐染色标记法观察分离视网膜的RGCs存活率,用双抗体一步夹心法酶联免疫吸附试验方法检测分离视网膜的脑源性神经营养因子(Brain derived neurotrophic factor, BDNF)的含量。结果:术后3、7、14及28天,在周边区及中央区视网膜上RGCs密度均显著减少(周边区:P3d=0.0446, P7d=0.0011, P14d 0.001, P28d0.001;中央区:P3d=0.0437, P7d=0.0067, P14d0.001, P28d0.001)。7天、14天、28天后,A组RGCs密度及BDNF含量均显著高于B组(P0.05)。结论:BMSCs移植可以减缓外伤性视神经损伤家猫RGCs凋亡,可能与其增加BDNF表达有关。 相似文献
8.
将bdnf基因克隆入逆转录病毒载体pLNCX,构建得到pLNC/BDNF,经PA317细胞包装后,感染大鼠成肌细胞L6TG,G418筛选2周后,得到稳定表达bdnf基因的细胞克隆L6TG/BDNF。DNA印迹结果证实bdnf基因已经整合入L6TG染色体中,RNA印迹和斑点印迹结果分别从mRNA水平和蛋白水平证明了bdnf基因的表达,且L6TG/BDNF培养上清中BDNF的含量约为25ng(106细胞数每ml每24h)。 相似文献
9.
Smita Jain Basu Dev Banerjee Rafat Sultana Ahmed Vinod Kumar Arora Pramod Kumari Mediratta 《Neurochemical research》2013,38(10):2136-2147
Triazophos, O,O-diethyl-1-H-1,2,4-triazol-3-yl phosphorothioate, (TZ) is an organophosphate pesticide widely used as an insecticide in agriculture fields, however, its adverse effects on cognitive function remain unknown till date. The present study was designed to identify the effect of TZ on cognitive function in order to gain an insight into the molecular mechanism(s) probably involved in TZ induced toxicity. Wistar male albino rats were orally administered with TZ at 8.2 mg/kg bw daily for 30 days. Cognitive function was assessed by evaluating step down latency (SDL) in passive avoidance apparatus, transfer latency (TL) on elevated plus maze and escape latency (EL) using morris water maze. The biochemical changes, in terms of malondialdehyde (MDA), reduced glutathione (GSH) and brain derived neurotrophic factor (BDNF) levels were evaluated in hippocampi regions. Relative mRNA expression and protein expression of BDNF were also evaluated. The results demonstrated that rats treated with TZ showed significantly (p < 0.01) reduced SDL and prolonged TL and EL as compared to control group rats. Moreover, significantly low (p < 0.01) mRNA expression and protein levels (p < 0.001) of BDNF, increased MDA and reduced GSH levels were observed in TZ treated rats. The study concludes that chronic exposure to TZ significantly impairs the learning and memory which may be attributed to the significantly reduced mRNA and protein expression of BDNF in hippocampus. Moreover, BDNF is negatively correlated to MDA levels and positively correlated to GSH levels. Hence, it can be suggested that interplay between BDNF and oxidative stress plays an important role in mediating the toxic effects of TZ. 相似文献
10.
Warren Caldwell Opal A. McInnis Robyn J. McQuaid Gele Liu John D. Stead Hymie Anisman Shawn Hayley 《PloS one》2013,8(6)
Disturbances of brain derived neurotrophic factor (BDNF) signalling have been implicated in the evolution of depression, which likely arises, in part, as a result of diminished synaptic plasticity. Predictably, given stressor involvement in depression, BDNF is affected by recent stressors as well as stressors such as neglect experienced in early life. The effects of early life maltreatment in altering BDNF signalling may be particularly apparent among those individuals with specific BDNF polymorphisms. We examined whether polymorphisms of the Val66Met genotype might be influential in moderating how early-life events play out with respect to later coping styles, cognitive flexibility and depressive features. Among male and female undergraduate students (N = 124), childhood neglect was highly related to subsequent depressive symptoms. This outcome was moderated by the BDNF polymorphism in the sense that depressive symptoms appeared higher in Met carriers who reported low levels of neglect than in those with the Val/Val allele. However, under conditions of high neglect depressive symptoms only increased in the Val/Val individuals. In effect, the Met polymorphism was associated with depressive features, but did not interact with early life neglect in predicting later depressive features. It was further observed that among the Val/Val individuals, the relationship between neglect and depression was mediated by emotion-focused styles and diminished perceived control, whereas this mediation was not apparent in Met carriers. In contrast to the more typical view regarding this polymorphism, the data are consistent with the perspective that in the presence of synaptic plasticity presumably associated with the Val/Val genotype, neglect allows for the emergence of specific appraisal and coping styles, which are tied to depression. In the case of the reduced degree of neuroplasticity expected in the Met carriers, early life adverse experiences are not tied to coping styles, and hence less likely to be translated into depressive states. 相似文献
11.
Kun Hua Matthew K. Schindler Joseph A. McQuail M. Elizabeth Forbes David R. Riddle 《PloS one》2012,7(12)
Radiation therapy has proven efficacy for treating brain tumors and metastases. Higher doses and larger treatment fields increase the probability of eliminating neoplasms and preventing reoccurrence, but dose and field are limited by damage to normal tissues. Normal tissue injury is greatest during development and in populations of proliferating cells but also occurs in adults and older individuals and in non-proliferative cell populations. To better understand radiation-induced normal tissue injury and how it may be affected by aging, we exposed young adult, middle-aged, and old rats to 10 Gy of whole brain irradiation and assessed in gray- and white matter the responses of microglia, the primary cellular mediators of radiation-induced neuroinflammation, and oligodendrocyte precursor cells, the largest population of proliferating cells in the adult brain. We found that aging and/or irradiation caused only a few microglia to transition to the classically “activated” phenotype, e.g., enlarged cell body, few processes, and markers of phagocytosis, that is seen following more damaging neural insults. Microglial changes in response to aging and irradiation were relatively modest and three markers of reactivity - morphology, proliferation, and expression of the lysosomal marker CD68- were regulated largely independently within individual cells. Proliferation of oligodendrocyte precursors did not appear to be altered during normal aging but increased following irradiation. The impacts of irradiation and aging on both microglia and oligodendrocyte precursors were heterogeneous between white- and gray matter and among regions of gray matter, indicating that there are regional regulators of the neural response to brain irradiation. By several measures, the CA3 region of the hippocampus appeared to be differentially sensitive to effects of aging and irradiation. The changes assessed here likely contribute to injury following inflammatory challenges like brain irradiation and represent important end-points for analysis in studies of therapeutic strategies to protect patients from neural dysfunction. 相似文献
12.
Jesús Ciriza Marcos García-Ojeda Inmaculada Martín-Burriel Cendra Agulhon Francisco Javier Miana-Mena Maria Jesus Muñoz Pilar Zaragoza Philippe Brûlet Rosario Osta 《Central European Journal of Biology》2008,3(2):105-112
Neurotrophic factors have been widely suggested as a treatment for multiple diseases including motorneuron pathologies, like
Amyotrophic Lateral Sclerosis. However, clinical trials in which growth factors have been systematically administered to Amyotrophic
Lateral Sclerosis patients have not been effective, owing in part to the short half-life of these factors and their low concentrations
at target sites. A possible strategy is the use of the atoxic C fragment of the tetanus toxin as a neurotrophic factor carrier
to the motorneurons. The activity of trophic factors should be tested because their genetic fusion to proteins could alter
their folding and conformation, thus undermining their neuroprotective properties. For this purpose, in this paper we explored
the Brain Derived Neurotrophic Factor (BDNF) activity maintenance after genetic fusion with the C fragment of the tetanus
toxin. We demonstrated that BDNF fused with the C fragment of the tetanus toxin induces the neuronal survival Akt kinase pathway
in mouse cortical culture neurons and maintains its antiapoptotic neuronal activity in Neuro2A cells. 相似文献
13.
14.
Lisa Dovere Stefania Fera Margherita Grasso Dante Lamberti Cesare Gargioli Barbara Muciaccia Anna Maria Lustri Mario Stefanini Elena Vicini 《PloS one》2013,8(4)
In mammals, the biological activity of the stem/progenitor compartment sustains production of mature gametes through spermatogenesis. Spermatogonial stem cells and their progeny belong to the class of undifferentiated spermatogonia, a germ cell population found on the basal membrane of the seminiferous tubules. A large body of evidence has demonstrated that glial cell line-derived neurotrophic factor (GDNF), a Sertoli-derived factor, is essential for in vivo and in vitro stem cell self-renewal. However, the mechanisms underlying this activity are not completely understood. In this study, we show that GDNF induces dose-dependent directional migration of freshly selected undifferentiated spermatogonia, as well as germline stem cells in culture, using a Boyden chamber assay. GDNF-induced migration is dependent on the expression of the GDNF co-receptor GFRA1, as shown by migration assays performed on parental and GFRA1-transduced GC-1 spermatogonial cell lines. We found that the actin regulatory protein vasodilator-stimulated phosphoprotein (VASP) is specifically expressed in undifferentiated spermatogonia. VASP belongs to the ENA/VASP family of proteins implicated in actin-dependent processes, such as fibroblast migration, axon guidance, and cell adhesion. In intact seminiferous tubules and germline stem cell cultures, GDNF treatment up-regulates VASP in a dose-dependent fashion. These data identify a novel role for the niche-derived factor GDNF, and they suggest that GDNF may impinge on the stem/progenitor compartment, affecting the actin cytoskeleton and cell migration. 相似文献
15.
Robertson SJ Mokgokong R Kania KD Guedj AS Hladky SB Barrand MA 《Cellular and molecular neurobiology》2011,31(7):1103-1111
Ischemia–reperfusion leads to increased levels at the blood–brain barrier of the multidrug efflux transporter, P-glycoprotein
that provides protection to the brain by limiting access of unwanted substances. This is coincident with the production of
nitric oxide. This present study using immortalized rat brain endothelial cells (GPNTs) examines whether following hypoxia-reoxygenation,
nitric oxide contributes to the alterations in P-glycoprotein levels. After 6 h of hypoxia, both nitric oxide and reactive
oxygen species, detected intracellularly using fluorescent monitoring dyes, were produced in the subsequent reoxygenation
phase coincident with increased P-glycoprotein. The evidence that nitric oxide can directly affect P-glycoprotein expression
was sought by applying S-nitroso-N-acetyl-dl-penicillamine that as shown increased the nitric oxide generation. Sodium nitroprusside, though more effective at increasing
P-glycoprotein expression, appeared to produce different reactive species. Real time RT-PCR analysis revealed the predominant
form of nitric oxide synthase in these cells to be endothelial, inhibition of which partially prevented the increase in P-glycoprotein
during reoxygenation. These data indicate that the production of nitric oxide by endothelial nitric oxide synthase during
reoxygenation can influence P-glycoprotein expression in cells of the blood-rat brain barrier, highlighting another route
by which nitric oxide may protect the brain. 相似文献
16.
Usuki S Ren J Utsunomiya I Cashman NR Inokuchi J Miyatake T 《Neurochemical research》2001,26(4):375-382
We previously reported that ciliary neurotrophic factor (CNTF) increased the serum-free cell survival of immortalized motor neuron-like cells (NSC-34), and addition of the exogenous ganglioside GalNAc4(Neu5Ac3)Gal4GlcCer (GM2) facilitated cell survival together with CNTF. Moreover 1,4 N-acetylgalactosaminyltransferase (GM2 synthase) activity increased in NSC-34 cells cultured with CNTF. We now have examined whether CNTF-induced cell survival is associated with the collaboration between GM2 and the CNTF receptor (CNTF-R). Despite the presence of CNTF (50 ng/ml), anti-CNTF-R antibody caused cell death and prevented the up-regulation of GM2 synthase expression. The addition of GM2 (1 to 20 M) abrogated the anti-CNTF-R antibody effect which shortened cell survival and blocked GM2 synthase activation. Use of [125I]CNTF showed the specificity of CNTF binding in NSC-34 cells in situ. GM2 produced a 5-fold increase in the CNTF binding affinity per cell but did not change the binding site number. The study by metabolic labeling with [1–14C]N-acetyl-D-galactosamine ([14C]GalNAc) showed that biosynthesized GM2 was involved in the immunoprecipitation of CNTF-R. These findings indicate that up-regulated GM2 synthesis induces functional conversion of CNTF-R to the activated state, in which it has affinity for CNTF. We conclude that GM2 is a bio-regulating molecule of CNTF-R in motor neurons. 相似文献
17.
William E. Louch Johan Hake Guro Five Jølle Halvor K. Mørk Ivar Sjaastad Glenn T. Lines 《Biophysical journal》2010,99(5):1377-1386
Cardiomyocytes from failing hearts exhibit spatially nonuniform or dyssynchronous sarcoplasmic reticulum (SR) Ca2+ release. We investigated the contribution of action potential (AP) prolongation in mice with congestive heart failure (CHF) after myocardial infarction. AP recordings from CHF and control myocytes were included in a computational model of the dyad, which predicted more dyssynchronous ryanodine receptor opening during stimulation with the CHF AP. This prediction was confirmed in cardiomyocyte experiments, when cells were alternately stimulated by control and CHF AP voltage-clamp waveforms. However, when a train of like APs was used as the voltage stimulus, the control and CHF AP produced a similar Ca2+ release pattern. In this steady-state condition, greater integrated Ca2+ entry during the CHF AP lead to increased SR Ca2+ content. A resulting increase in ryanodine receptor sensitivity synchronized SR Ca2+ release in the mathematical model, thus offsetting the desynchronizing effects of reduced driving force for Ca2+ entry. A modest nondyssynchronous prolongation of Ca2+ release was nevertheless observed during the steady-state CHF AP, which contributed to increased time-to-peak measurements for Ca2+ transients in failing cells. Thus, dyssynchronous Ca2+ release in failing mouse myocytes does not result from electrical remodeling, but rather other alterations such as T-tubule reorganization. 相似文献
18.
M. Shamsul Ola Mohd Imtiaz Nawaz Ahmed Abu El-Asrar Marwan Abouammoh Abdullah S. Alhomida 《Cellular and molecular neurobiology》2013,33(3):359-367
Diabetic retinopathy (DR) is widely recognized as a neurovascular disease. Retina, being a neuronal tissue of the eye, produces neurotrophic factors for its maintenance. However, diabetes dysregulates their levels and thereby may damage the retina. Among neurotrophins, brain derived neurotrophic factor (BDNF) is the most abundant in the retina. In this study, we investigated the level of BDNF in the serum of patients with DR and also in the serum and retina of streptozotocin-induced diabetic rats. The level of BDNF was significantly decreased in the serum of proliferative diabetic retinopathy patients as compared to that of non-diabetic healthy controls (25.5 ± 8.5–10.0 ± 8.1 ng/ml, p < 0.001) as well as compared to that of diabetic patients with no retinopathy (21.8 ± 4.7–10.0 ± 8.1 ng/ml, p < 0.001), as measured by ELISA techniques. The levels of BDNF in the serum and retina of diabetic rats were also significantly reduced compared to that of non-diabetic controls (p < 0.05). In addition, the expression level of tropomyosin-related kinase B (TrkB) was significantly decreased in diabetic rat retina compared to that of non-diabetic controls as determined by Western blotting technique. Caspase-3 activity was increased in diabetic rat retina after 3 weeks of diabetes and remained elevated until 10 weeks, which negatively correlated with the level of BDNF (r = ?0.544, p = 0.013). Our results indicate that reduced levels of BDNF in diabetes may cause apoptosis and neurodegeneration early in diabetic retina, which may lead to neuro-vascular damage later in DR. 相似文献
19.
Characterization of TLX Expression in Neural Stem Cells and Progenitor Cells in Adult Brains 总被引:1,自引:0,他引:1
TLX has been shown to play an important role in regulating the self-renewal and proliferation of neural stem cells in adult brains. However, the cellular distribution of endogenous TLX protein in adult brains remains to be elucidated. In this study, we used immunostaining with a TLX-specific antibody to show that TLX is expressed in both neural stem cells and transit-amplifying neural progenitor cells in the subventricular zone (SVZ) of adult mouse brains. Then, using a double thymidine analog labeling approach, we showed that almost all of the self-renewing neural stem cells expressed TLX. Interestingly, most of the TLX-positive cells in the SVZ represented the thymidine analog-negative, relatively quiescent neural stem cell population. Using cell type markers and short-term BrdU labeling, we demonstrated that TLX was also expressed in the Mash1+ rapidly dividing type C cells. Furthermore, loss of TLX expression dramatically reduced BrdU label-retaining neural stem cells and the actively dividing neural progenitor cells in the SVZ, but substantially increased GFAP staining and extended GFAP processes. These results suggest that TLX is essential to maintain the self-renewing neural stem cells in the SVZ and that the GFAP+ cells in the SVZ lose neural stem cell property upon loss of TLX expression.Understanding the cellular distribution of TLX and its function in specific cell types may provide insights into the development of therapeutic tools for neurodegenerative diseases by targeting TLX in neural stem/progenitors cells. 相似文献
20.
Brandon C. Shelley Geneviève Gowing Clive N. Svendsen 《Journal of visualized experiments : JoVE》2014,(88)
A cell expansion technique to amass large numbers of cells from a single specimen for research experiments and clinical trials would greatly benefit the stem cell community. Many current expansion methods are laborious and costly, and those involving complete dissociation may cause several stem and progenitor cell types to undergo differentiation or early senescence. To overcome these problems, we have developed an automated mechanical passaging method referred to as “chopping” that is simple and inexpensive. This technique avoids chemical or enzymatic dissociation into single cells and instead allows for the large-scale expansion of suspended, spheroid cultures that maintain constant cell/cell contact. The chopping method has primarily been used for fetal brain-derived neural progenitor cells or neurospheres, and has recently been published for use with neural stem cells derived from embryonic and induced pluripotent stem cells. The procedure involves seeding neurospheres onto a tissue culture Petri dish and subsequently passing a sharp, sterile blade through the cells effectively automating the tedious process of manually mechanically dissociating each sphere. Suspending cells in culture provides a favorable surface area-to-volume ratio; as over 500,000 cells can be grown within a single neurosphere of less than 0.5 mm in diameter. In one T175 flask, over 50 million cells can grow in suspension cultures compared to only 15 million in adherent cultures. Importantly, the chopping procedure has been used under current good manufacturing practice (cGMP), permitting mass quantity production of clinical-grade cell products. 相似文献