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Auffinger B, Tobias AL, Han Y, Lee G, Guo D, Dey M, Lesniak MS, Ahmed AU. Conversion of differentiated cancer cells into cancer stem-like cells in a glioblastoma model after primary chemotherapy. Cell Death Differ 2014; 21:1119-31. [PMID: 24608791 DOI: 10.1038/cdd.2014.31] [Citation(s) in RCA: 244] [Impact Index Per Article: 24.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/11/2013] [Revised: 02/03/2014] [Accepted: 02/03/2014] [Indexed: 12/28/2022] Open
Abstract
Glioblastoma multiforme patients have a poor prognosis due to therapeutic resistance and tumor relapse. It has been suggested that gliomas are driven by a rare subset of tumor cells known as glioma stem cells (GSCs). This hypothesis states that only a few GSCs are able to divide, differentiate, and initiate a new tumor. It has also been shown that this subpopulation is more resistant to conventional therapies than its differentiated counterpart. In order to understand glioma recurrence post therapy, we investigated the behavior of GSCs after primary chemotherapy. We first show that exposure of patient-derived as well as established glioma cell lines to therapeutic doses of temozolomide (TMZ), the most commonly used antiglioma chemotherapy, consistently increases the GSC pool over time both in vitro and in vivo. Secondly, lineage-tracing analysis of the expanded GSC pool suggests that such amplification is a result of a phenotypic shift in the non-GSC population to a GSC-like state in the presence of TMZ. The newly converted GSC population expresses markers associated with pluripotency and stemness, such as CD133, SOX2, Oct4, and Nestin. Furthermore, we show that intracranial implantation of the newly converted GSCs in nude mice results in a more efficient grafting and invasive phenotype. Taken together, these findings provide the first evidence that glioma cells exposed to chemotherapeutic agents are able to interconvert between non-GSCs and GSCs, thereby replenishing the original tumor population, leading to a more infiltrative phenotype and enhanced chemoresistance. This may represent a potential mechanism for therapeutic relapse.
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Zeng F, Li S, Yang J, Pan F, Guo D. Learning processes modulated by the interface effects in a Ti/conducting polymer/Ti resistive switching cell. RSC Adv 2014. [DOI: 10.1039/c3ra46679e] [Citation(s) in RCA: 46] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
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103
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Hui Q, Ma J, Song J, Liu Z, Ren H, Jiang W, Wang Y, Xu Y, Guo D, Zhang X, Lu S. In vitro and in vivo studies of antitumor effects of the recombinant immunotoxin MSH-PE38KDEL on melanoma. Neoplasma 2014; 61:392-400. [PMID: 25027740 DOI: 10.4149/neo_2014_048] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
MSH-PE38KDEL is a chimeric molecule composed of MSH, and fused to a truncated mutant form of Pseudomonas exotoxin (PE38KDEL). Our study aims to evaluate the specific cytotoxicity of recombinant immunotoxin MSH-PE38KDEL on melanoma cells A875 and B16 in vitro, as well as its inhibition of metastatic melanoma in vivo. MSH-PE38KDEL was expressed in Escherichia coli, and greater than 90% purity was obtained. The purified MSH-PE38KDEL was found to be selectively cytotoxic to MSH receptor-positive melanoma cells in vitro. The specific cytotoxicity of recombinant MSH-PE38KDEL to A875 and B16 was over 85% by cell viability assay; however, MSH-PE38KDEL had no cytotoxicity to the human 2BS cells. The anti-tumor activity of MSH-PE38KDEL was evaluated in mice with induced melanoma through intra-tumor or intravenous administration. The results showed that 90% melanoma growths were inhibited, and 40% of the tumors were disappeared completely. Histopathology results showed MSH-PE38KDEL can effectively inhibit intrahepatic metastasis. In conclusion, MSH-PE38KDEL had cytotoxic effects on MSH receptor-positive melanoma cells, and causes significant tumor growth inhibition. These results support a possible new approach for the treatment of melanoma.
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Ren J, Xu S, Guo D, Zhang J, Liu S. Increased expression of α5β1-integrin is a prognostic marker for patients with gastric cancer. Clin Transl Oncol 2013; 16:668-74. [PMID: 24248895 DOI: 10.1007/s12094-013-1133-y] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/15/2013] [Accepted: 11/01/2013] [Indexed: 11/24/2022]
Abstract
OBJECTIVE The study was to evaluate the association of expression level of α5β1-integrin with clinicopathologic features and prognosis in gastric cancer (GC). METHODS The expression of α5β1-integrin in normal gastric mucosa and GC tissue was detected with immunohistochemistry. The level of α5 and β1 mRNA in GC tissues and non-neoplastic tissues was evaluated in 48 paired cases by quantitative real-time polymerase chain reaction (qRT-PCR). Survival analysis by the Kaplan-Meier method was performed to assess prognostic significance. RESULTS The α5β1-integrin expression was detected in 68.3 % (127/186) GC samples, and there was a significant difference on their positive expression rate between GC tissue and normal gastric mucosa (P < 0.001). The positive expression rate of α5β1-integrin in patients with poor histologic differentiation (P = 0.001), lymph node metastasis (P < 0.001), and recurrence (P < 0.001) group was heightened. Using Kaplan-Meier analysis, a comparison of survival curves of low versus high expresser of α5β1-integrin revealed a highly significant difference in human GC tissue (P = 0.002), which suggested that overexpression of α5β1-integrin is associated with a worse prognosis. Multivariate analyses showed that α5β1-integrin expression was independent risk factor predicting overall survival [Hazard ratio (HR) 1.594, 95 % confidence interval (CI) 1.236-2.408, P = 0.006] and disease-free survival [HR 3.952, 95 % CI 1.676-9.861, P = 0.003] in GC. CONCLUSIONS The α5β1-integrin promotes angiogenesis and associates with lymph node metastasis, vascular invasion and poor prognosis of GC. The current study shows that α5β1-integrin may be an independent prognostic factor for GC patients.
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Fačevicová K, Hron K, Todorov V, Guo D, Templ M. Logratio approach to statistical analysis of 2×2 compositional tables. J Appl Stat 2013. [DOI: 10.1080/02664763.2013.856871] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
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Zhang J, Wang L, Fu W, Wang C, Guo D, Jiang J, Wang Y. Smooth muscle cell phenotypic diversity between dissected and unaffected thoracic aortic media. THE JOURNAL OF CARDIOVASCULAR SURGERY 2013; 54:511-21. [PMID: 23594508] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 06/02/2023]
Abstract
AIM Smooth muscle cell (SMC) phenotypic switching in the aortic media may play a critical role in the pathogenesis of thoracic aortic dissection (TAD). However, few investigations are available and most of the observations are based on histological examinations without in vitro evidence. This study, which was performed both in vivo and in vitro, was designed to investigate SMC phenotypic diversity between dissected and unaffected aortic media. METHODS Using optimized explant technique, aortic medial SMCs were obtained from patients with TAD and controls. In vivo and in vitro expression of α-smooth muscle actin (α-SMA), smooth muscle-myosin heavy chain 2 (SM-MHC-2), smooth muscle-calponin (SM-Calponin), Vimentin, osteopontin (OPN) and non-muscle myosin heavy chain B (SMemb) were evaluated by immunostaining and immunoblotting. SMC proliferation was also analyzed. RESULTS Although the majority of SMCs from the dissected media displayed an elongated, spindle- or triangle-like shape as control SMCs, there were some oval or flat, quadrate cells in the dissection cultures. In contrast with controls, SMCs derived from the dissected media uniformly showed the negative staining for the contractile proteins and the intense staining for the synthetic markers. Similarly, in vitro protein levels of α-SMA, SM-MHC-2, SM-Calponin and Vimentin were significantly decreased to 60.1% (P<0.05), 12.0% (P<0.01), 23.1% (P<0.01) and 32.5% (P<0.01) respectively, whereas those of OPN and SMemb were markedly elevated by5.7- and 10.3-fold respectively (P<0.01 for both). In vivo expression of the phenotypic markers showed the parallel results. Furthermore, SMCs derived from the dissected media exhibited the enhanced proliferation (P<0.05). CONCLUSION We have established a simple and potent method to acquire SMCs from the dissected and unaffected aortic media. Compared to the contractile SMCs in the unaffected media, those in the dissected media manifest phenotypic switching from the contractile to the synthetic type. The primary cultures can be subsequently used as in vitro models and contribute to further elucidating the etiopathogenesis of TAD.
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Feng L, Zhang D, Fan C, Ma C, Yang W, Meng Y, Wu W, Guan S, Jiang B, Yang M, Liu X, Guo D. ER stress-mediated apoptosis induced by celastrol in cancer cells and important role of glycogen synthase kinase-3β in the signal network. Cell Death Dis 2013; 4:e715. [PMID: 23846217 PMCID: PMC3730400 DOI: 10.1038/cddis.2013.222] [Citation(s) in RCA: 43] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/08/2012] [Revised: 05/03/2013] [Accepted: 05/06/2013] [Indexed: 01/13/2023]
Abstract
HeLa cells treated with celastrol, a natural compound with inhibitive effect on proteasome, exhibited increase in apoptotic rate and characteristics of apoptosis. To clarify the signal network activated by celastrol to induce apoptosis, both the direct target proteins and undirect target proteins of celastrol were searched in the present study. Proteasome catalytic subunit β1 was predicted by computational analysis to be a possible direct target of celastrol and confirmed by checking direct effect of celastrol on the activity of recombinant human proteasome subunit β1 in vitro. Undirect target-related proteins of celastrol were searched using proteomic studies including two-dimensional electrophoresis (2-DE) analysis and iTRAQ-based LC-MS analysis. Possible target-related proteins of celastrol such as endoplasmic reticulum protein 29 (ERP29) and mitochondrial import receptor Tom22 (TOM22) were found by 2-DE analysis of total cellular protein expression profiles. Further study showed that celastrol induced ER stress and ER stress inhibitor could ameliorate cell death induced by celastrol. Celastrol induced translocation of Bax into the mitochondria, which might be related to the upregulation of BH-3-only proteins such as BIM and the increase in the expression level of TOM22. To further search possible target-related proteins of celastrol in ER and ER-related fractions, iTRAQ-based LC-MS method was use to analyze protein expression profiles of ER/microsomal vesicles-riched fraction of cells with or without celastrol treatment. Based on possible target-related proteins found in both 2-DE analysis and iTRAQ-based LC-MS analysis, protein–protein interaction (PPI) network was established using bioinformatic analysis. The important role of glycogen synthase kinase-3β (GSK3β) in the signal cascades of celastrol was suggested. Pretreatment of LiCL, an inhibitor of GSK3β, could significantly ameliorate apoptosis induced by celastrol. On the basis of the results of the present study, possible signal network of celastrol activated by celastrol leading to apoptosis was predicted.
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Guo D, Li C, Teng Q, Sun Z, Li Y, Zhang C. Notch1 overexpression promotes cell growth and tumor angiogenesis in myeloma. Neoplasma 2013; 60:33-40. [PMID: 23067214 DOI: 10.4149/neo_2013_005] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
Patients with multiple myeloma (MM) have increased bone marrow angiogenesis, but the angiogenic properties of myeloma cells and the mechanism of MM-induced angiogenesis have not been completely clarified. Notch1 signal has been identified as a critical factor in the regulation of vessel formation. However, the role of Notch1 in the angiogenesis of MM is unclear. We constitutively overexpressed active Notch1 in RPMI8226 cells to explore the effect of Notch1 signaling on cell growth and tumor angiogenesis in vivo and in vitro. We found that Notch1 overexpression promoted myeloma cells growth and increased drug resistance. Moreover, vascular endothelial growth factor (VEGF) expression was increased. Finally, our in vitro results were supported by the in vivo finding in human myeloma xenograft Nonobese diabetic/severe combined immunodeficient (NOD/SCID) models. Notch1 overexpression in MM cells resulted in up-regulation of VEGF expression, promotion of tumor growth, and increased microvessel density (MVD). Our study suggests that Notch1-induced angiogenesis is partly due to activation of VEGF pathway.
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Tan W, Wang F, Guo D, Ke Y, Shen Y, Zhang M. AB0343 A high serum level of haptoglobin is associated with the response of 12 weeks methotrexate therapy in recent-onset rheumatoid arthritis patients. Ann Rheum Dis 2013. [DOI: 10.1136/annrheumdis-2012-eular.343] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
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Li H, Guo D, Tian W, Peng S. Cloning and molecular characterization of a cDNA encoding a small GTPase from Hevea brasiliensis. GENETICS AND MOLECULAR RESEARCH 2013; 12:3305-13. [DOI: 10.4238/2013.september.3.7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
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Zhang Q, Li J, Li Y, Chang Q, Chen Y, Jiang H, Zhao Z, Guo D. Expression and localization of the vascular endothelial growth factor and changes of microvessel density during hair follicle development of Liaoning cashmere goats. GENETICS AND MOLECULAR RESEARCH 2013; 12:6424-32. [DOI: 10.4238/2013.december.10.3] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
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Yan Y, Guo D, Wen S. Numerical simulation of junction point pressure during droplet formation in a microfluidic T-junction. Chem Eng Sci 2012. [DOI: 10.1016/j.ces.2012.08.055] [Citation(s) in RCA: 39] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
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Guo D, Shi X, Arledge K, Song D, Jiang L, Fu L, Zhang S, Wang X, Zhang L. V5 region in the HIV-1 envelope glycoprotein determines viral sensitivity to the broadly neutralizing monoclonal antibody VRC01. Retrovirology 2012. [PMCID: PMC3442108 DOI: 10.1186/1742-4690-9-s2-p46] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022] Open
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Gao FS, Bai J, Zhang XH, Zhang WJ, Guo D, Zhang S. Molecular characteristics of the SLA-2 gene from Chinese Hebao pigs. RUSS J GENET+ 2012. [DOI: 10.1134/s1022795412010073] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
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Gao FS, Bai J, Zhang XH, Zhang WJ, Guo D, Zhang S. Molecular characteristics of the SLA-2 gene from Chinese Hebao pigs. GENETIKA 2012; 48:253-259. [PMID: 22568003] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 05/31/2023]
Abstract
To study the molecular characteristics of swine leukocyte antigen (SLA) class I from the Hebao pig, a rare inbreed in China, a pair of primers was designed to amplify the SLA-2 gene (SLA-2-HB) and then the molecular characteristics of the gene were analyzed by computer. After cloning, sequencing and computer analysis, four SLA-2-HB alleles were found, all of 1119 bp. Sites 3-1097 were an open reading frame encoding 364 amino acids with two sets of intra-chain disulfide bonds comprising four cysteines situated in sites 125, 188, 227 and 283. By alignment of SLA-2-HB sequences with other SLA-2 alleles in the DNA Data Bank of Japan/European Molecular Biology Laboratory/GenBank database, nine key variable amino acid sites were found in the extracellular domain of the SLA-2-HB alleles at sites 23(F), 24(I), 43(A), 44(K), 50(Q), 73(N), 95(I), 114(R) and 216(S), which could be used to differentiate other SLA-2 alleles. The amino acid identities between SLA-2-HB and other SLA-2, SLA-3 and SLA-1 alleles were 87.1-97.0%, 85.0-93.9% and 83.3- 88.6%, respectively. The phylogenetic tree of SLA-2-HB showed that it was relatively independent of the other SLA-2 genes. Furthermore, the SLA-2-HB alleles were similar to HLA-B15 and HLA-A2 functional do- mains and preserved some functional sites of HLA-A2. It was concluded that SLA-2-HB is an allele of SLA-2 and that the Hebao pig might have evolved independently in China.
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Kibe R, Zhang S, Guo D, Marrero L, Tsien F, Rodriguez P, Khan S, Zieske A, Huang J, Li W, Durum SK, Iwakuma T, Cui Y. IL-7Rα deficiency in p53null mice exacerbates thymocyte telomere erosion and lymphomagenesis. Cell Death Differ 2012; 19:1139-51. [PMID: 22281704 DOI: 10.1038/cdd.2011.203] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022] Open
Abstract
Interleukin-7 (IL-7) is an essential T-cell survival cytokine. IL-7 receptor (IL-7Rα) deficiency severely impairs T-cell development due to substantial apoptosis. We hypothesized that IL-7Rα(null)-induced apoptosis is partially contributed by an elevated p53 activity. To investigate the genetic association of IL-7/IL-7Rα signaling with the p53 pathway, we generated IL-7Rα(null)p53(null) (DKO) mice. DKO mice exhibited a marked reduction of apoptosis in developing T cells and an augmented thymic lymphomagenesis with telomere erosions and exacerbated chromosomal anomalies, including chromosome duplications, breaks, and translocations. In particular, Robertsonian translocations, in which telocentric chromosomes fuse at the centromeric region, and a complete loss of telomeres at the fusion site occurred frequently in DKO thymic lymphomas. Cellular and molecular investigations revealed that IL-7/IL-7Rα signaling withdrawal diminished the protein synthesis of protection of telomere 1 (POT1), a subunit of telomere protective complex shelterin, leading to telomere erosion and the activation of the p53 pathway. Blockade of IL-7/IL-7Rα signaling in IL-7-dependent p53(null) cells reduced POT1 expression and caused telomere and chromosome abnormalities similar to those observed in DKO lymphomas. This study underscores a novel function of IL-7/IL-7Rα during T-cell development in regulating telomere integrity via POT1 expression and provides new insights into cytokine-mediated survival signals and T-cell lymphomagenesis.
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Guo D, Knight TE, McCusker JK. Angular Momentum Conservation in Dipolar Energy Transfer. Science 2011; 334:1684-7. [DOI: 10.1126/science.1211459] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/02/2022]
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Locasale JW, Melman T, Song SS, Yang X, Swanson KD, Cantley LC, Asara JM, Wong ET, Adams S, Braidy N, Teo C, Guillemin G, Philippe M, Carole C, David T, Eric G, Isabelle NM, de Paula Andre M, Marylin B, Olivier C, L'Houcine O, Dominique FB, Leukel P, Seliger C, Vollmann A, Jachnik B, Bogdahn U, Hau P, Liu X, Kumar VS, McPherson CM, Chow L, Kendler A, Dasgupta B, Piya S, White E, Klein S, Jiang H, Lang F, Alfred Yung WK, Gomez-Manzano C, Fueyo J, Vartanian A, Guha A, Fenton KE, Abdelwahab M, Scheck AC, Guo D, Reinitz F, Youssef M, Hong C, Nathanson D, Akhavan D, Kuga D, Amzajerdi AN, Soto H, Zhu S, Babic I, Iwanami A, Tanaka K, Gini B, DeJesus J, Lisiero DD, Huang T, Prins R, Wen P, Robbins HI, Prados M, DeAngelis L, Mellinghoff I, Mehta M, James CD, Chakravarti A, Cloughesy T, Tontonoz P, Mischel P, Phillips J, Mukherjee J, Cowdrey C, Wiencke J, Pieper RO, Bachoo R, Marin-Valencia I, Cho S, Rakheja D, Hatanpaa K, Mashimo T, Vemireddy V, Kapur P, Good L, Sun X, Pascual J, Takahashi M, Togao O, Raisanen J, Maher EA, DeBerardinis R, Malloy C, Maher EA, Bachoo R, Marin-Valencia I, Hatanpaa K, Choi C, Mashimo T, Raisanen J, Mathews D, Pascual J, Madden C, Mickey B, Malloy C, DeBerardinis R, Mukherjee J, Zheng S, Phillips J, Cowdrey C, Ronen S, Wiencke J, Pieper RO, Park I, Jalbert LE, Ito M, Ozawa T, James CD, Phillips JJ, Vigneron DB, Pieper RO, Ronen SM, Nelson SJ. METABOLIC PATHWAYS. Neuro Oncol 2011; 13:iii69-iii72. [PMCID: PMC3199168 DOI: 10.1093/neuonc/nor153] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 08/14/2023] Open
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Zhu H, Guo D, Li K, Pedersen-White J, Stallmann-Jorgensen IS, Huang Y, Parikh S, Liu K, Dong Y. Increased telomerase activity and vitamin D supplementation in overweight African Americans. Int J Obes (Lond) 2011; 36:805-9. [PMID: 21986705 DOI: 10.1038/ijo.2011.197] [Citation(s) in RCA: 50] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
OBJECTIVE We aimed to investigate whether vitamin D supplementation modulates peripheral blood mononuclear cell (PBMC) telomerase activity in overweight African Americans. DESIGN A double blind, randomized and placebo-controlled clinical trial (#NCT01141192) was recently conducted. SUBJECTS AND METHODS African-American adults were randomly assigned to either the placebo, or the vitamin D group (60,000 IU per month (equivalent to ~2000 IU per day) oral vitamin D3 supplementation). Fresh PBMCs were collected from 37 subjects (18 in the placebo group and 19 in the vitamin D group), both at baseline and 16 weeks. PBMC telomerase activity was measured by the telomeric repeat amplification protocol. RESULTS Serum 25 hydroxyvitamin D levels increased from 40.7±15.7 at baseline to 48.1±17.5 nmol l(-1) at posttest (P=0.004) in the placebo group, and from 35.4±11.3 at baseline to 103.7±31.5 nmol l(-1) at posttests (P<0.0001) in the vitamin D group. In the vitamin D group, PBMC telomerase activity increased by 19.2% from baseline (1.56±0.29 absorbance reading unit (AU)) to posttest (1.86±0.42 AU, P<0.0001). The significance persisted after controlling for age, sex and body mass index (P=0.039). PBMC telomerase activity in the placebo group did not change from baseline (1.43±0.26 AU) to posttest (1.46±0.27 AU, P=0.157). CONCLUSION Vitamin D supplementation significantly increased PBMC telomerase activity in overweight African Americans. Our data suggest that vitamin D may improve telomere maintenance and prevent cell senescence and counteract obesity-induced acceleration of cellular aging.
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Wang W, Zhong B, Sun J, Cao J, Tian J, Zhong N, Zhao W, Tian L, Xu P, Guo D, Ju X, Ma W, Li M, Hou W, Lu S. Down-regulated HS6ST2 in osteoarthritis and Kashin-Beck disease inhibits cell viability and influences expression of the genes relevant to aggrecan metabolism of human chondrocytes. Rheumatology (Oxford) 2011; 50:2176-86. [DOI: 10.1093/rheumatology/ker230] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
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Liu S, Guo D, Guo Y, Zhou W. Preparation and pharmacokinetics of ceftiofur sodium liposomes in cows. J Vet Pharmacol Ther 2011; 34:35-41. [PMID: 21219342 DOI: 10.1111/j.1365-2885.2010.01190.x] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
The objective of this study was to prepare ceftiofur sodium liposomes and assess their physical properties, stability, antibacterial effects, and pharmacokinetics. These liposomes appeared as a milky, light yellow suspension with encapsulation efficiency at 57.2 ± 1.17%, and there were no significant changes in all estimated indexes at 4 °C for 90 days. The minimum inhibitory concentrations of liposomes were all 1/4th that of ceftiofur sodium against Streptococcus suis, Staphylococcus aureus, Escherichia coli, and Salmonella enteritidis. Six healthy, adult cows in two treatment groups were dosed intravenously with ceftiofur sodium liposomes and ceftiofur sodium, serial blood samples collected, and plasma concentrations determined by high performance liquid chromatography. Intravenous plasma concentration profiles of liposomes best fit a two-compartment model and the elimination half-life was 2.11 times that of ceftiofur sodium. Thus, this liposome preparation provided therapeutically effective plasma concentrations for a longer duration than with the drug alone, making it more effective and convenient for use in treating bovine mastitis that requires long duration maintenance of therapeutic plasma concentrations.
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Zhou H, Yan Y, Xu G, Zhou B, Wen H, Guo D, Zhou F, Wang H. Toll-like receptor (TLR)-4 mediates anti-β2GPI/β2GPI-induced tissue factor expression in THP-1 cells. Clin Exp Immunol 2010; 163:189-98. [PMID: 21091668 DOI: 10.1111/j.1365-2249.2010.04291.x] [Citation(s) in RCA: 36] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022] Open
Abstract
Our previous study demonstrated that annexin A2 (ANX2) on cell surface could function as a mediator and stimulate tissue factor (TF) expression of monocytes by anti-β₂-glycoprotein I/β₂-glycoprotein I complex (anti-β₂GPI/β₂GPI). However, ANX2 is not a transmembrane protein and lacks the intracellular signal transduction pathway. Growing evidence suggests that Toll-like receptor 4 (TLR-4) might act as an 'adaptor' for intracellular signal transduction in anti-β₂GPI/β₂GPI-induced TF expressing cells. In the current study, we investigated the roles of TLR-4 and its related molecules, myeloid differentiation protein 2 (MD-2) and myeloid differentiation factor 88 (MyD88), in anti-β₂GPI/β₂GPI-induced TF expressing human monocytic-derived THP-1 (human acute monocytic leukaemia) cells. The relationship of TLR-4 and ANX2 in this process was also explored. Along with TF, expression of TLR-4, MD-2 and MyD88 in THP-1 cells increased significantly when treated by anti-β₂GPI (10 µg/ml)/β₂GPI (100 µg/ml) complex. The addition of paclitaxel, which competes with the MD-2 ligand, could inhibit the effects of anti-β₂GPI/β₂GPI on TLR-4, MD-2, MyD88 and TF expression. Both ANX2 and TLR-4 in THP-1 cell lysates could bind to β₂GPI that had been conjugated to a column (β₂GPI-Affi-Gel). Furthermore, TLR-4, MD-2, MyD88 and TF expression was remarkably diminished in THP-1 cells infected with ANX2-specific RNA interference (RNAi) lentivirus (LV-RNAi-ANX2), in spite of treatment with a similar concentration of anti-β₂GPI/β₂GPI complex. These results indicate that TLR-4 and its signal transduction pathway contribute to anti-β₂GPI/β₂GPI-induced TF expression in THP-1 cells, and the effects of TLR-4 with ANX2 are tightly co-operative.
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Zhang W, Zhao J, Guo D, Zhong W, Shu J, Luo Y. [Application of susceptibility weighted imaging in revealing intratumoral blood products and grading gliomas]. ACTA ACUST UNITED AC 2010; 91:485-90. [PMID: 20514004 DOI: 10.1016/s0221-0363(10)70063-9] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
Abstract
OBJECTIVE Susceptibility weighted imaging (SWI) is a novel imaging method that utilizes the magnetic susceptibility differences between tissues. The purpose of our study was to evaluate the application of SWI for revealing inratumoral blood products and diagnosing high-grade gliomas. MATERIALS AND METHODS Conventional MR sequences and SWI were performed in 32 patients, 10 low-grade gliomas (1 grade I and 9 grade II) and 22 high-grade gliomas (8 grade III and 14 grade IV). The ability of SWI for detecting inratumral blood products was analyzed and compared with conventional MR sequences. Logistic regression and Receiver operating characteristic (ROC) curve analysis were used to evaluate the diagnostic value of SWI for high-grade gliomas. RESULTS SWI was sensitive for showing intrtumoral blood products (P=0.00) and depicted much more micro bleeds. No statistical difference was found in detection rate of blood products between low-grade and high-grade group. According to the result of logistic regression, the frequency of blood products and the diameter of maximum blood products were significant determinants of high-grade gliomas. The result of ROC analysis indicated that with an optimal cut-off point (0.67), the sensitivity, specificity, positive predictive value and negative predictive value for diagnosing high-grade gliomas with blood products detected by SWI were 81.8%, 80.0%, 90.0%, and 66.6%, respectively. CONCLUSION SWI can accurately detect blood products with superlative contrast. With a high-grade gliomas risk estimation model based on two variables, satisfied sensitivity, specificity, PPV and NPV were obtained. Thus, SWI could be a useful adjunct sequence in glioma grading.
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Cheng XL, Zhang H, Guo D, Qiao ZD. Upregulation of Fas and FasL expression in nicotine-induced apoptosis of endothelial cells. ACTA ACUST UNITED AC 2010; 32:13-8. [PMID: 20383341 DOI: 10.1358/mf.2010.32.1.1428742] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/19/2022]
Abstract
Although smoking-related coronary vascular disease is well documented, the effects of nicotine have not been fully investigated. There is controversy over reports about the effect of nicotine on apoptosis. The effect of nicotine on apoptosis of human umbilical vein endothelial cells (HUVECs) and the expressions of Fas/Fas ligand (FasL) and caspase-3 were evaluated in this study. Annexin V fluorescein isothiocyanate and propidium iodide double staining demonstrated that nicotine (0.2 microM, 0.5 microM and 1 microM) could induce apoptosis of HUVECs; reverse transcription (RT)-PCR and Western blotting analysis demonstrated that levels of Fas and FasL expression were increased in nicotine-treated HUVECs. Moreover, caspase-3 expression was also increased. These data indicate that nicotine induces the apoptosis of HUVECs, and that the Fas/FasL pathway may play an important role. This provides evidence that nicotine may have an important role in cardiovascular pathology and atherogenesis.
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Gluhak-Heinrich J, Guo D, Yang W, Harris MA, Lichtler A, Kream B, Zhang J, Feng JQ, Smith LC, Dechow P, Harris SE. New roles and mechanism of action of BMP4 in postnatal tooth cytodifferentiation. Bone 2010; 46:1533-45. [PMID: 20206312 PMCID: PMC2875306 DOI: 10.1016/j.bone.2010.02.024] [Citation(s) in RCA: 53] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/28/2009] [Revised: 01/22/2010] [Accepted: 02/24/2010] [Indexed: 11/28/2022]
Abstract
During the phase of overt tooth cytodifferentiation that occurs after birth in the mouse and using the 3.6Collagen1a-Cre and the BMP4 floxed and BMP4 knockout mice, the BMP4 gene was deleted in early collagen producing odontoblasts around postnatal day 1. BMP4 expression was reduced over 90% in alveolar osteoblasts and odontoblasts. There was decreased rate of predentin to dentin formation and decreased mature odontoblast differentiation reflected in reduced DMP1 expression and proper dentinal tubule formation, as well as reduced Collagen type I and Osteocalcin expression. We observed mutant dysmorphogenic odontoblasts that failed to properly elongate and differentiate. The consequence of this failed differentiation process leads to permanent loss of dentin thickness, apparent enlarged pulp chambers in the molars and reduced bone supporting the tooth structures in mice as old as 10-12 months. Deletion of the BMP4 gene in odontoblasts also indirectly disrupted the process of enamel formation that persisted throughout life. The mechanism for this altered differentiation program in the absence of the BMP4 gene in odontoblasts is from decreased BMP signaling, and decreased expression of three key transcription factors, Dlx3, Dlx5, and Osterix. BMP signaling, as well as Dlx3 and Amelogenin expression, is also indirectly reduced in the ameloblasts of the odontoblast BMP4 cKO mice. This supports a key paracrine or endocrine postnatal role of odontoblast derived BMP4 on the proper amelogenesis and formation of the enamel.
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