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《Cell cycle (Georgetown, Tex.)》2013,12(23)
Comment on: Ertel A, et al. Cell Cycle 2010; 9:4153–63. 相似文献
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Jori FP Napolitano MA Melone MA Cipollaro M Cascino A Giordano A Galderisi U 《Journal of cellular physiology》2004,200(2):201-212
Marrow stromal cells (MSCs) are stem-like cells having a striking somatic plasticity. In fact, besides differentiating into mesenchymal lineages (bone, cartilage, and fat), they are capable of differentiating into neurons and astrocytes in vitro and in vivo. The RB and RB2/P130 genes, belonging to the retinoblastoma gene family, play a key role in neurogenesis, and for this reason, we investigated their role in neural commitment and differentiation of MSCs. In MSCs that were either uncommitted or committed toward neural differentiation, we ectopically expressed RB and RB2/P130 genes and analyzed their role in regulating the cell cycle, apoptosis and differentiation. In uncommitted MSCs, the activity of RB and RB2/P130 appeared limited to negatively regulating cell cycle progression, having no role in apoptosis and differentiation (toward either mesenchymal or neural lineages). On the other hand, in MSCs committed toward the neural phenotype, both RB and RB2/P130 reduced cell proliferation rate and affected the apoptotic process. RB protected differentiating cells from programmed cell death. On the contrary, RB2/P130 increased the percentage of cells in apoptosis. All of these activities were accomplished mainly in an HDAC-independent way. The retinoblastoma genes also influenced differentiation in neural committed MSCs. RB2/P130 contributes mainly to the induction of generic neural properties, while RB triggers cholinergic differentiation. These differentiating activities are HDAC-dependent. Our research shows that there is a critical temporal requirement for the RB genes during neuronal differentiation of MSCs: they are not required for cell commitment but play a role in the maturation process. For the above reasons, RB and RB2/P130 may have a role in neural differentiation but not in neural determination. 相似文献
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In this study we characterized a bacteriocin, warnericin RB4, produced by Staphylococcus warneri RB4. Warnericin RB4 activity was completely inactivated by trypsin and actinase E. The activity was stable at 100°C for 15 min, and had a pH range of 2 to 6. S. warneri RB4 showed antibacterial activity against only Alicyclobacillus acidoterrestris, A. acidocaldarius, and Micrococcus luteus, among 34 bacterial species tested. The amino acid sequence of the purified bacteriocin contained 27 amino acid residues (K-K-K-S-G-V-I-P-X-V-X-H-D-X-H-M-N-X-F-Q-F-V-F-X-X-X-S). The molecular mass of the bacteriocin was estimated to be 2,958.2 Da by ESI-MS. These results show that the Warnericin RB4 exhibiting specific antibacterial activity against thermo-acidophiles, Alicyclobacillus spp., is a Nukacin ISK-1 or closely related bacteriocin, classified with class IA (Lacticin 481 types). This is the first report that Warnericin RB-4 is effective to inhibit the growth of causative microorganisms of spoilage in various acidic drinks. Warnericin RB4 might prove useful in fruit juices and fruit juice–containing drinks. 相似文献
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Biochemical studies have identified two proteins, RB47 and RB60, that are involved in the light-regulated translation of the psbA mRNA in the chloroplast of the unicellular alga Chlamydomonas reinhardtii. RB47, a member of the eukaryotic poly(A)-binding protein family, binds directly to the 5' untranslated region of the mRNA, whereas RB60, a protein disulfide isomerase (PDI), is thought to bind to RB47 and to modulate its activity via redox and phosphorylation events. Our present studies show that RB47 forms a single disulfide bridge that most probably involves Cys143 and Cys259. We found that RB60 reacts with high selectivity with the disulfide of RB47, suggesting that the redox states of these two redox partners are coupled. Kinetics analysis indicated that RB47 contains two fast reacting cysteines, of which at least one is sensitive to changes in pH conditions. The results support the notion that light controls the redox regulation of RB47 function via the coupling of RB47 and RB60 redox states, and suggest that light-induced changes in stromal pH might contribute to the regulation. 相似文献
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Elaine M. S. Dorneles Graciela K. Lima Andréa Teixeira-Carvalho Márcio S. S. Araújo Olindo A. Martins-Filho Nammalwar Sriranganathan Hamzeh Al Qublan Marcos B. Heinemann Andrey P. Lage 《PloS one》2015,10(9)
Brucella abortus S19 and RB51 strains have been successfully used to control bovine brucellosis worldwide; however, currently, most of our understanding of the protective immune response induced by vaccination comes from studies in mice. The aim of this study was to characterize and compare the immune responses induced in cattle prime-immunized with B. abortus S19 or RB51 and revaccinated with RB51. Female calves, aged 4 to 8 months, were vaccinated with either vaccine S19 (0.6–1.2 x 1011 CFU) or RB51 (1.3 x 1010 CFU) on day 0, and revaccinated with RB51 (1.3 x 1010 CFU) on day 365 of the experiment. Characterization of the immune response was performed using serum and peripheral blood mononuclear cells. Blood samples were collected on days 0, 28, 210, 365, 393 and 575 post-immunization. Results showed that S19 and RB51 vaccination induced an immune response characterized by proliferation of CD4+ and CD8+ T-cells; IFN-ɣ and IL-17A production by CD4+ T-cells; cytotoxic CD8+ T-cells; IL-6 secretion; CD4+ and CD8+ memory cells; antibodies of IgG1 class; and expression of the phenotypes of activation in T-cells. However, the immune response stimulated by S19 compared to RB51 showed higher persistency of IFN-ɣ and CD4+ memory cells, induction of CD21+ memory cells and higher secretion of IL-6. After RB51 revaccination, the immune response was chiefly characterized by increase in IFN-ɣ expression, proliferation of antigen-specific CD4+ and CD8+ T-cells, cytotoxic CD8+ T-cells and decrease of IL-6 production in both groups. Nevertheless, a different polarization of the immune response, CD4+- or CD8+-dominant, was observed after the booster with RB51 for S19 and RB51 prime-vaccinated animals, respectively. Our results indicate that after prime vaccination both vaccine strains induce a strong and complex Th1 immune response, although after RB51 revaccination the differences between immune profiles induced by prime-vaccination become accentuated. 相似文献
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Montanaro L Vici M Donati G Ceccarelli C Santini D Treré D Derenzini M 《Histology and histopathology》2007,22(7):769-775
Recent data challenge the relevance of the RB pathway to cancer based on RB inactivation, at least in breast tumors. To obtain information on the actual role of the components of the RB pathway in tumor progression we decided to investigate whether their quantitative changes were associated with variations in the level of RB phosphorylation in human breast cancer. A series of 68 human primary breast carcinomas was studied. Five cases were excluded from the study due to their lack of RB expression. In the remaining 63 cases the expression of cyclin D1, cdk4, cyclin E, and INK4a mRNA was assessed by real-time RT-PCR. The level of RB phosphorylated protein (ppRB) and p27 expression was immunohistochemically analyzed by measuring the percentage of stained cells (labeling index, LI). Cell proliferation rate was measured by Ki67 LI evaluation. The ppRB LI ranged from 5.2 to 73.8 and, as expected, was strongly related to the Ki67 LI (r=0.80; p<0.001). The expression of cyclin D1 mRNA, expressed in arbitrary units (a. u.), ranged from 1.15 to 123.0 and was inversely related to the ppRB LI (p=0.021) and Ki67 LI (p<0.001). Neither the cdk4 (range from 0.07 to 1.13 a. u.) nor the cyclin E (range from 0.13 to 9.27 a. u.) mRNA expression was significantly associated with the ppRB LI (p=0.962 and p=0.103, respectively). Cyclin E was related to Ki67 LI (p=0.022). Both INK4a mRNA (range from 0.01 to 0.60 a. u.) and p27 (LI from 0.0 to 73.1) values were inversely related to the ppRB LI (p=0.022 and p=0.014, respectively). Cyclin D1, cdk4, and cyclin E mRNA expressions were not significantly related to one another. In human primary breast cancers, the expression levels of the factors known to facilitate the cell cycle progression by RB protein phosphorylation were not positively related to ppRB-LI. Pathological increases of cyclin D, cdk4, and cyclin E are very likely associated with other biological functions other than their well-established action on cell cycle progression. 相似文献
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Currently, lifelong immunosuppression is required for organ transplant recipients. The majority of transplant recipients will eventually develop chronic rejection with resultant graft loss, despite treatment with powerful immunosuppressive agents. These agents are also associated with numerous toxicities including reduced immunity against infection and malignancy. Therefore, the central goal in transplant science is to devise tolerance strategies in an attempt to establish a state of prolonged non-reactivity against the allograft, accompanied with preservation of an intact immune system. Although predictable tolerance induction has been elusive, we found that short course of the novel immunomodulatory agent, anti-CD45RB monoclonal antibody, leads to indefinite acceptance of renal allografts in mice, and has been shown to markedly prolong allograft survival in primates. We review the current state of development of this antibody, and the progress made in defining its mechanism of action. 相似文献