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2.
Zhongguo Zhen Jiu ; 44(4): 449-454, 2024 Apr 12.
Artigo em Inglês, Chinês | MEDLINE | ID: mdl-38621733

RESUMO

OBJECTIVES: To observe the effects of moxibustion on intestinal barrier function and Toll-like receptor 4 (TLR4)/nuclear factor-κB p65 (NF-κB p65) signaling pathway in obese rats and explore the mechanism of moxibustion in the intervention of obesity. METHODS: Fifty-five Wistar rats of SPF grade were randomly divided into a normal group (10 rats) and a modeling group (45 rats). In the modeling group, the obesity model was established by feeding high-fat diet. Thirty successfully-modeled rats were randomized into a model group, a moxibustion group, and a placebo-control group, with 10 rats in each one. In the moxibustion group, moxibustion was applied at the site 3 cm to 5 cm far from the surface of "Zhongwan" (CV 12), with the temperature maintained at (46±1 ) ℃. In the placebo-control group, moxibustion was applied at the site 8 cm to 10 cm far from "Zhongwan" (CV 12), with the temperature maintained at (38±1) ℃. The intervention was delivered once daily for 8 weeks in the above two groups. The body mass and food intake of the rats were observed before and after intervention in each group. Using ELISA methool, the levels of serum triacylglycerol (TG), total cholesterol (TC) and lipopolysaccharide (LPS) were detected and the insulin resistance index (HOMA-IR) was calculated. HE staining was used to observe the morphology of colon tissue. The mRNA expression of zonula occludens-1 (ZO-1), Occludin, Claudin-1, TLR4 and NF-κB p65 in the colon tissue was detected by quantitative real-time PCR; and the protein expression of ZO-1, Occludin, Claudin-1, TLR4 and NF-κB p65 was detected by Western blot in the rats of each group. RESULTS: Compared with the normal group, the body mass, food intake, the level of HOMA-IR, and the serum levels of TC, TG and LPS were increased in the rats of the model group (P<0.01); those indexes in the moxibustion group were all reduced when compared with the model group and the placebo-control group respectively (P<0.01, P<0.05). Compared with the normal group, a large number of epithelial cells in the mucosa of colon tissue was damaged, shed, and the inflammatory cells were infiltrated obviously in the interstitium in the rats of the model group. When compared with the model group, in the moxibustion group, the damage of the colon tissue was recovered to various degrees and there were few infiltrated inflammatory cells in the interstitium, while, the epithelial injury of the colon tissue was slightly recovered and the infiltrated inflammatory cells in the interstitium were still seen in the placebo-control group. The mRNA and protein expressions of ZO-1, Occludin and Caudin-1 were decreased in the model group compared with those in the normal group (P<0.01). When compared with the model group and the placebo-control group, the mRNA and protein expressions of these indexes were increased in the moxibustion group (P<0.01, P<0.05). In the model group, the mRNA and protein expressions of TLR4 and NF-κB p65 were increased when compared with those in the normal group (P<0.01), and the mRNA and protein expressions of these indexes were reduced in the moxibustion group when compared with those in the model group and the placebo-control group (P<0.01). CONCLUSIONS: Moxibustion can reduce the body mass and food intake, regulate the blood lipid and improve insulin resistance in the rats of obesity. It may be related to alleviating inflammatory response through improving intestinal barrier function and modulating the intestinal TLR4/NF-κB p65 signaling pathway.


Assuntos
Resistência à Insulina , Moxibustão , Ratos , Animais , NF-kappa B/genética , NF-kappa B/metabolismo , Ratos Wistar , Receptor 4 Toll-Like/genética , Lipopolissacarídeos/metabolismo , Função da Barreira Intestinal , Ocludina/metabolismo , Claudina-1/metabolismo , Transdução de Sinais , Obesidade/genética , Obesidade/terapia , RNA Mensageiro/metabolismo , Fator de Necrose Tumoral alfa/metabolismo
3.
ACS Biomater Sci Eng ; 10(1): 255-270, 2024 Jan 08.
Artigo em Inglês | MEDLINE | ID: mdl-38118130

RESUMO

The number of patients with bone defects caused by trauma, bone tumors, and osteoporosis has increased considerably. The repair of irregular, recurring, and large bone defects poses a great challenge to clinicians. Bone tissue engineering is emerging as an appropriate strategy to replace autologous bone grafting in the repair of critically sized bone defects. However, the suitability of bone tissue engineering scaffolds in terms of structure, mechanics, degradation, and the microenvironment is inadequate. Three-dimensional (3D) printing is an advanced additive-manufacturing technology widely used for bone repair. 3D printing constructs personalized structurally adapted scaffolds based on 3D models reconstructed from CT images. The contradiction between the mechanics and degradation is resolved by altering the stacking structure. The local microenvironment of the implant is improved by designing an internal pore structure and a spatiotemporal factor release system. Therefore, there has been a boom in the 3D printing of personalized bone repair scaffolds. In this review, successful research on the preparation of highly bioadaptive bone tissue engineering scaffolds using 3D printing is presented. The mechanisms of structural, mechanical, degradation, and microenvironmental adaptations of bone prostheses and their interactions were elucidated to provide a feasible strategy for constructing highly bioadaptive bone tissue engineering scaffolds.


Assuntos
Engenharia Tecidual , Alicerces Teciduais , Humanos , Engenharia Tecidual/métodos , Alicerces Teciduais/química , Osso e Ossos/diagnóstico por imagem , Osso e Ossos/cirurgia , Impressão Tridimensional
4.
Eur Spine J ; 33(3): 1098-1108, 2024 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-38153529

RESUMO

PURPOSE: This study aimed to establish a nomogram to predict the risk of venous thromboembolism (VTE), identifying potential risk factors, and providing theoretical basis for prevention of VTE after spinal surgery. METHODS: A retrospective analysis was conducted on 2754 patients who underwent spinal surgery. The general characteristics of the training group were initially screened using univariate logistic analysis, and the LASSO method was used for optimal prediction. Subsequently, multivariate logistic regression analysis was performed to identify independent risk factors for postoperative VTE in the training group, and a nomogram for predict risk of VTE was established. The discrimination, calibration, and clinical usefulness of the nomogram were separately evaluated using the C-index, receiver operating characteristic curve, calibration plot and clinical decision curve, and was validated using data from the validation group finally. RESULTS: Multivariate logistic regression analysis identified 10 independent risk factors for VTE after spinal surgery. A nomogram was established based on these independent risk factors. The C-index for the training and validation groups indicating high accuracy and stability of the model. The area under the receiver operating characteristic curve indicating excellent discrimination ability; the calibration curves showed outstanding calibration for both the training and validation groups. Decision curve analysis showed the clinical net benefit of using the nomogram could be maximized in the probability threshold range of 0.01-1. CONCLUSION: Patients undergoing spinal surgery with elevated D-dimer levels, prolonger surgical, and cervical surgery have higher risk of VTE. The nomogram can provide a theoretical basis for clinicians to prevent VTE.


Assuntos
Nomogramas , Tromboembolia Venosa , Humanos , Estudos Retrospectivos , Tromboembolia Venosa/epidemiologia , Tromboembolia Venosa/etiologia , Tromboembolia Venosa/prevenção & controle , Procedimentos Neurocirúrgicos , Pescoço , Fatores de Risco
5.
Biomater Sci ; 11(11): 3813-3827, 2023 May 30.
Artigo em Inglês | MEDLINE | ID: mdl-37052182

RESUMO

Cancer is a severe threat to human life and health and represents the main cause of death globally. Drug therapy is one of the primary means of treating cancer; however, most anticancer medications do not proceed beyond preclinical testing because the conditions of actual human tumors are not effectively mimicked by traditional tumor models. Hence, bionic in vitro tumor models must be developed to screen for anticancer drugs. Three-dimensional (3D) bioprinting technology can produce structures with built-in spatial and chemical complexity and models with accurately controlled structures, a homogeneous size and morphology, less variation across batches, and a more realistic tumor microenvironment (TME). This technology can also rapidly produce such models for high-throughput anticancer medication testing. This review describes 3D bioprinting methods, the use of bioinks in tumor models, and in vitro tumor model design strategies for building complex tumor microenvironment features using biological 3D printing technology. Moreover, the application of 3D bioprinting in vitro tumor models in drug screening is also discussed.


Assuntos
Bioimpressão , Neoplasias , Humanos , Bioimpressão/métodos , Avaliação Pré-Clínica de Medicamentos , Microambiente Tumoral , Neoplasias/tratamento farmacológico , Impressão Tridimensional , Engenharia Tecidual , Alicerces Teciduais
6.
J Cardiothorac Surg ; 18(1): 61, 2023 Feb 06.
Artigo em Inglês | MEDLINE | ID: mdl-36747271

RESUMO

BACKGROUND: Rib fractures are a common injury in trauma. Potential complications include pain, pneumonia, respiratory failure, disability, and death. Surgical stabilization of rib fractures (SSRF) has become an available treatment option, and complete video-assisted thoracoscopic surgery (VATS) for SSRF is gradually accepted because of minimally invasive and pain relief. To our knowledge, complete uni-port VATS for SSRF has not yet been reported. CASE PRESENTATION: A 53-year-old man accidentally fell off a three-meter high scaffolding while working resulting in severe chest pain and shortness of breath. He was found with left 7th through 11th rib fractures with a pulmonary contusion from computed tomography (CT). A 4 cm incision was made in the 7th intercostal space in the midaxillary line, and complete uni-port VATS for SSRF were operated. The patient's pain was significantly relieved after the operation, and the scar was tiny and unapparent. CONCLUSIONS: Complete uni-port VATS for SSRF is a novel and modificatory method of operation with the benefit of minimal invasion, meanwhile, intrathoracic injuries could be treated at the same time. Further study is warranted.


Assuntos
Fraturas das Costelas , Parede Torácica , Masculino , Humanos , Pessoa de Meia-Idade , Fraturas das Costelas/cirurgia , Fraturas das Costelas/complicações , Cirurgia Torácica Vídeoassistida/métodos , Fixação de Fratura/métodos , Dor , Estudos Retrospectivos
7.
Front Bioeng Biotechnol ; 10: 1039117, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-36394003

RESUMO

Treating critical-size bone defects beyond the body's self-healing capacity is a challenging clinical task. In this study, we investigate the effect of concentrate growth factors (CGFs) loaded Poloxamer 407 hydrogel on the viability and osteogenic differentiation potential of bone marrow mesenchymal stem cells (BMSCs) and reconstruction of critical-size bone defects. In vitro, this CGFs-loaded thermosensitive hydrogel can significantly promote proliferation, maintain cell viability, and induce osteogenic differentiation of BMSCs by up-regulating the mineralization and alkaline phosphatase (ALP) activity, as well as gene markers, including runt-related transcription factor-2 (Runx-2), type I collagen (Col-1), osteocalcin (OCN), as well as osteopontin (OPN). In vivo, Micro-CT radiography analysis and histological detection demonstrated that the CGFs-loaded hydrogel significantly induced bone healing and reconstructed the medullary cavity structure in critical-size bone defect models. In conclusion, this strategy of transplantation of CGFs-loaded hydrogel promoted bone regeneration and prevented bone nonunion, so as to provide basis for clinical treatment for repairing critical-size bone defects.

8.
Orthop Surg ; 14(3): 522-529, 2022 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-35098677

RESUMO

OBJECTIVE: To evaluate the placement feasibility and safety of the newly designed retropharyngeal reduction plate by cadaveric test and to perform morphometric trajectory analysis. METHODS: The five cadaveric specimens with intact atlantoaxial joint were enrolled in this study. They were used for simulating the placement process and evaluating the placement feasibility of the retropharyngeal reduction plate. The atlantoaxial dislocation (AAD) of five cadaveric specimens were obtained by proper external force after dissecting ligaments. The retropharyngeal reduction plate was placed on atlantoaxial joint of cadaveric specimens. The X-ray and three-dimensional (3D) spiral CT were used for evaluating the placement safety of retropharyngeal reduction plate. The DICOM data was obtained after 3D spiral CT scanning for the morphometric trajectory analysis. RESULTS: The reduction plates were successfully placed on the atlantoaxial joint of five cadaveric specimens through the retropharyngeal approach, respectively. The X-ray and 3D spiral CT showed the accurate screw implantation and satisfying plate placement. The length of the left/right atlas screw trajectory (L/RAT) was, respectively, 1.73 ± 0.01 cm (LAT) and 1.71 ± 0.02 cm (RAT). The length of odontoid screw trajectory (OST) was 1.38 ± 0.02 cm. The length of the left/right axis screw trajectory (L/RAXT) was, respectively, 1.67 ± 0.02 cm (LAXT) and 1.67 ± 0.01 cm (RAXT). There was no statistical significance between left side and right side in terms of AT and AXT (P > 0.05). The angles of atlas screw trajectory angle (ASTA), axis screw trajectory angle (AXSTA), and odontoid screw trajectory angle (OSTA) were 38.04° ± 2.03°, 56.92° ± 2.66°, and 34.78° ± 2.87°, respectively. CONCLUSION: The cadaveric test showed that the retropharyngeal reduction plate is feasible to place on the atlantoaxial joint, which is also a safe treatment choice for atlantoaxial dislocation. The meticulous preoperative planning of screw trajectory based on individual differences was also vital to using this technique.


Assuntos
Articulação Atlantoaxial , Luxações Articulares , Fusão Vertebral , Articulação Atlantoaxial/diagnóstico por imagem , Articulação Atlantoaxial/cirurgia , Placas Ósseas , Parafusos Ósseos , Cadáver , Humanos , Luxações Articulares/diagnóstico por imagem , Luxações Articulares/cirurgia , Tomografia Computadorizada por Raios X
9.
Chem Asian J ; 11(11): 1697-704, 2016 06 06.
Artigo em Inglês | MEDLINE | ID: mdl-27062081

RESUMO

Development of high-strength hydrogels has recently attracted ever-increasing attention. In this work, a new design strategy has been proposed to prepare graphene oxide (GO)/polyacrylamide (PAM)/aluminum ion (Al(3+) )-cross-linked carboxymethyl hemicellulose (Al-CMH) nanocomposite hydrogels with very tough and elastic properties. GO/PAM/Al-CMH hydrogels were synthesized by introducing graphene oxide (GO) into PAM/CMH hydrogel, followed by ionic cross-linking of Al(3+) . The nanocomposite hydrogels were characterized by means of FTIR, X-ray diffraction (XRD), and scanning electron microscopy/energy-dispersive X-ray analysis (SEM-EDX) along with their swelling and mechanical properties. The maximum compressive strength and the Young's modulus of GO3.5 /PAM/Al-CMH0.45 hydrogel achieved values of up to 1.12 and 13.27 MPa, increased by approximately 6488 and 18330 % relative to the PAM hydrogel (0.017 and 0.072 MPa). The as-prepared GO/PAM/Al-CMH nanocomposite hydrogels possess high strength and great elasticity giving them potential in bioengineering and drug-delivery system applications.

10.
Exp Ther Med ; 6(1): 152-158, 2013 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-23935737

RESUMO

The aim of this study was to investigate the method of posterior thoracolumbar vertebral pedicle screw reduction and fixation combined with vertebral bone implantation via the affected vertebral body under navigational aid for the treatment of thoracolumbar fractures. The efficacy of the procedure was also measured. Between June 2005 and March 2011, posterior thoracolumbar vertebral pedicle screw reduction and fixation plus artificial bone implantation via the affected vertebral pedicle under navigational aid was used to treat 30 patients with thoracolumbar fractures, including 18 males and 12 females, ranging in age from 21 to 57 years. Compared with the values prior to surgery, intraspinal occupation, vertebral height ratio and Cobb angle at the follow-up were significantly improved. At the long-term follow-up, the postoperative Cobb angle loss was <1° and the anterior vertebral body height loss was <2 mm. Posterior thoracolumbar vertebral pedicle screw reduction and fixation combined with vertebral bone implantation via the affected vertebral body under navigational aid may increase the accuracy and safety of surgery, and it is an ideal method of internal implantation. Bone implantation via the affected vertebral body may increase vertebral stability.

11.
Oncol Lett ; 5(4): 1133-1139, 2013 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-23599752

RESUMO

In this study, we used a substance P (SP) immunohistochemical method to analyze the expression localization of osteoprotegerin (OPG) and osteoprotegerin ligand (OPGL) in giant cell tumor (GCT) of the bone, and to detect the clinical significance of their expression. The data showed that the positive expression rate of OPG in the multinucleated giant cells (MGCs) and stromal cells (STCs) of GCT was 80.65 and 74.19%, respectively. The positive expression rate of OPG in MGCs was correlated with age and prognosis (P<0.05), but not in STCs. The strength of positive OPG expression in MGCs and STCs was negatively correlated with prognosis (rs=-0.397, P<0.05; rs=-0.390, P<0.05, respectively). The positive expression rate of OPGL in the MGCs and STCs was 41.94 and 67.74%, respectively. The positive expression rate of OPGL in the MGCs was correlated with age and prognosis (P<0.05); the strength of OPGL expression in MGCs was positively correlated with Campanicci's grade and recurrence. Additionally, the positive expression rate of OPGL in STCs was correlated with age and Jaffe's grade (P<0.05). The strength of OPGL expression in STCs was negatively correlated with Jaffe's grade (rs=-0.534, P<0.05). In conclusion, OPG and OPGL are expressed in MGCs and STCs in GCT of the bone. The invasion of tumor cells was positively correlated with OPGL in MGCs, which confirmed that MGCs participate in the process of osteolytic destruction of GCT of bone.

12.
IUBMB Life ; 64(7): 628-35, 2012 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-22539488

RESUMO

MicroRNAs are a class of small endogenous non-coding RNAs that function as post-transcriptional regulators. In our previous study, we found that miR-181b was significantly downregulated in human gastric adenocarcinoma tissue samples compared to the adjacent normal gastric tissues. In this study, we confirm the down-regulation of miR-181b in human gastric cancer cell lines versus the gastric epithelial cells. Overexpression of miR-181b suppressed the proliferation and colony formation rate of gastric cancer cells. miR-181b downregulated the expression of cAMP responsive element binding protein 1 (CREB1) by binding its 3' untranslated region. Overexpression of CREB1 counteracted the suppression of growth in gastric cancer cells caused by ectopic expression of miR-181b. These results indicate that miR-181b may function as a tumor suppressor in gastric adenocarcinoma cells through negative regulation of CREB1.


Assuntos
Adenocarcinoma/metabolismo , Proteína de Ligação ao Elemento de Resposta ao AMP Cíclico/biossíntese , Regulação Neoplásica da Expressão Gênica , MicroRNAs/metabolismo , Neoplasias Gástricas/metabolismo , Regiões 3' não Traduzidas , Proliferação de Células , Perfilação da Expressão Gênica , Proteínas de Fluorescência Verde/metabolismo , Humanos , Oligonucleotídeos Antissenso/genética
13.
FEBS J ; 279(7): 1252-60, 2012 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-22325466

RESUMO

MicroRNAs (miRNAs) constitute a class of noncoding RNAs that post-transcriptionally regulate gene expression. Recent evidence indicates that many miRNAs function as oncogenes or tumor suppressors by negatively regulating their target genes. In our previous study, using miRNA microarray analysis, we found that miRNA-182 (miR-182) was significantly downregulated in human gastric adenocarcinoma tissue samples. Here, we confirmed the downregulation of miR-182 in a larger sample of gastric tissue samples. Overexpression of miR-182 suppressed the proliferation and colony formation of gastric cancer cells. An oncogene, encoding cAMP-responsive element binding protein 1 (CREB1), serves as a direct target gene of miR-182. A fluorescent reporter assay confirmed that miR-182 binds specifically to the predicted site of the CREB1 mRNA 3'-UTR. When miR-182 was overexpressed in gastric cancer cell lines, both the mRNA and protein levels of CREB1 were depressed. Furthermore, CREB1 was present at a high level in human gastric adenocarcinoma tissues, and this was inversely correlated with miR-182 expression. Ectopic expression of CREB1 overcame the suppressive phenotypes of gastric cancer cells caused by miR-182. These results indicate that miR-182 targets the CREB1 gene and suppresses gastric adenocarcinoma cell growth, suggesting that miR-182 shows tumor-suppressive activity in human gastric cancer.


Assuntos
Adenocarcinoma/metabolismo , Adenocarcinoma/patologia , Proteína de Ligação ao Elemento de Resposta ao AMP Cíclico/metabolismo , MicroRNAs/metabolismo , Neoplasias Gástricas/metabolismo , Neoplasias Gástricas/patologia , Regiões 3' não Traduzidas , Adenocarcinoma/genética , Idoso , Proliferação de Células , Proteína de Ligação ao Elemento de Resposta ao AMP Cíclico/genética , Feminino , Regulação Neoplásica da Expressão Gênica , Humanos , Masculino , MicroRNAs/genética , Pessoa de Meia-Idade , Neoplasias Gástricas/genética
14.
Eur Spine J ; 19(5): 713-9, 2010 May.
Artigo em Inglês | MEDLINE | ID: mdl-20174838

RESUMO

Anterior decompression and fusion is an established procedure in surgical treatment for multilevel cervical spondylotic myelopathy (MCSM). However, contiguous corpectomies and fusion (CCF) often induce postoperative complications such as nonunion, graft subsidence, and loss of lordotic alignment. As an alternative, noncontiguous corpectomies or one-level corpectomy plus adjacent-level discectomy with retention of an intervening body has been developed recently. In this study, we prospectively compared noncontiguous anterior decompression and fusion (NADF) and CCF for MCSM in terms of surgical invasiveness, clinical and radiographic outcomes, and complications. From January 2005 to June 2007, 105 patients with MCSM were randomized to NADF group (n = 55) and CCF group (n = 50), and followed up for average 31.5 months (range 24-48 months). Average operative time and blood loss decreased significantly in the NADF group as compared with those in the CCF group (p < 0.05 and <0.001, respectively). For VAS, within 3 months postoperatively, there was no significant difference between the two groups. But at 6 months after surgery and final follow-up, VAS improved significantly in NADF group than that in CCF group (p < 0.05). No significant difference of JOA score was observed between the two groups at every collection time. In NADF group, all 55 cases obtained fusion at 1 year after operation (average 5.1 months). In CCF group, 48 cases achieved fusion 1 year postoperatively, but the other 2 cases were performed posterior stabilization and achieved fusion 6 months later. The differences of cervical lordosis between two groups were insignificant at the same follow-up time. But the loss of lordosis and height of fusion segments in 6 months postoperatively and final follow-up were significantly more in CFF group than in NADF group (p < 0.001). Complications were similar in both groups. But in CCF group three cases needed reoperation, one case with extradural hematoma was immediately re-operated after anterior decompression and two cases mentioned above were performed posterior stabilization at 1 year postoperatively. In conclusion, in the patients with MCSM, without developmental stenosis and continuous or combined ossification of posterior longitudinal ligaments, NADF and CCF showed an identical effect of decompression. In terms of surgical time, blood loss, VAS, fusion rate and cervical alignment, NADF was superior compared with CCF.


Assuntos
Vértebras Cervicais/cirurgia , Laminectomia/métodos , Fusão Vertebral/métodos , Espondilose/cirurgia , Idoso , Vértebras Cervicais/diagnóstico por imagem , Discotomia/efeitos adversos , Discotomia/métodos , Feminino , Humanos , Laminectomia/efeitos adversos , Masculino , Pessoa de Meia-Idade , Ossificação do Ligamento Longitudinal Posterior/complicações , Ossificação do Ligamento Longitudinal Posterior/diagnóstico por imagem , Ossificação do Ligamento Longitudinal Posterior/cirurgia , Medição da Dor , Dor Pós-Operatória/etiologia , Estudos Prospectivos , Radiografia , Reoperação , Fusão Vertebral/efeitos adversos , Estenose Espinal/complicações , Estenose Espinal/diagnóstico por imagem , Estenose Espinal/cirurgia , Espondilose/complicações , Espondilose/diagnóstico por imagem , Resultado do Tratamento
15.
PLoS One ; 4(5): e5498, 2009.
Artigo em Inglês | MEDLINE | ID: mdl-19430532

RESUMO

BACKGROUND: CD133 (Prominin) is widely used as a marker for the identification and isolation of neural precursor cells from normal brain or tumor tissue. However, the assumption that CD133 is expressed constitutively in neural precursor cells has not been examined. METHODOLOGY/PRINCIPAL FINDINGS: In this study, we demonstrate that CD133 and a second marker CD15 are expressed heterogeneously in uniformly undifferentiated human neural stem (NS) cell cultures. After fractionation by flow cytometry, clonogenic tripotent cells are found in populations negative or positive for either marker. We further show that CD133 is down-regulated at the mRNA level in cells lacking CD133 immunoreactivity. Cell cycle profiling reveals that CD133 negative cells largely reside in G1/G0, while CD133 positive cells are predominantly in S, G2, or M phase. A similar pattern is apparent in mouse NS cell lines. Compared to mouse NS cells, however, human NS cell cultures harbour an increased proportion of CD133 negative cells and display a longer doubling time. This may in part reflect a sub-population of slow- or non-cycling cells amongst human NS cells because we find that around 5% of cells do not take up BrdU over a 14-day labelling period. Non-proliferating NS cells remain undifferentiated and at least some of them are capable of re-entry into the cell cycle and subsequent continuous expansion. CONCLUSIONS: The finding that a significant fraction of clonogenic neural stem cells lack the established markers CD133 and CD15, and that some of these cells may be dormant or slow-cycling, has implications for approaches to identify and isolate neural stem cells and brain cancer stem cells. Our data also suggest the possibility that CD133 may be specifically down-regulated during G0/G1, and this should be considered when this marker is used to identify and isolate other tissue and cancer stem cells.


Assuntos
Antígenos CD/metabolismo , Glicoproteínas/metabolismo , Neurônios/metabolismo , Peptídeos/metabolismo , Células-Tronco/metabolismo , Antígeno AC133 , Animais , Antígenos CD/genética , Linhagem Celular , Proliferação de Células , Células Clonais/citologia , Células Clonais/metabolismo , Citometria de Fluxo , Fase G1 , Expressão Gênica , Glicoproteínas/genética , Humanos , Imuno-Histoquímica , Antígeno Ki-67/análise , Antígenos CD15/análise , Neurônios/citologia , Peptídeos/genética , RNA Mensageiro/genética , RNA Mensageiro/metabolismo , Ratos , Fase de Repouso do Ciclo Celular , Reação em Cadeia da Polimerase Via Transcriptase Reversa , Células-Tronco/citologia , Células-Tronco Totipotentes/citologia , Células-Tronco Totipotentes/metabolismo
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