962 resultados para growth differentiation factor 9
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Question: Low back pain is an increasing global health problem, which is associated with intervertebral disc (IVD) damage and de- generation. Major changes occur in the nucleus pulposus (NP), with the degradation of the extracellular matrix (ECM) [1]. Further studies showed that growth factors from the transforming growth factor (TGF) and bone morphogenic proteins (BMP) family may induce chondrogenic differentiation of mesenchymal stem cells (MSC) [2]. Focusing on non-viral gene therapies and their possible translation into the clinics, we investigated if GDF6 (syn. BMP13 or CDMP2) can induce regeneration of degraded NP. We hypothesized that IVD transfected with plasmid over-expressing GDF6 also up-regulates other NP- and chondrogenic cell markers and enhances ECM deposition. Methods: Bovine IVD cells were isolated by pronase/collagenase II overnight digestion. After monolayer expansion up to passage 3, cells were transfected with the plasmid pGDF6 (RG211366, Origene, SF) or with green fluorescence protein (GFP) control using the NeonÒ transfection system (Invitrogen, Basel), both equipped with a Cy- tomegalovirus (CMV) promotor to induce over-expression. We tested a range of yet unpublished parameters for each of the primary disc cells to optimize efficiency. To test a non-viral gene therapy applied directly to 3D whole organ culture, bovine IVDs were harvested from fresh tails obtained from the abattoir within 5 h post-mortem [3]. Discs were then pre-incubated for 24 h in high glucose Dulbecco’s Modified Eagle Medium and 5 % fetal calf serum. Each disc was transfected by injection of 5 lg of plasmid GDF6 (Origene, RG211366) into the center by 25G needle and using Hamilton sy- ringe. Electroporation was performed using 2-needle array electrode or tweezertrodes; 8 pulses at 200mv/cm with an interval of 10 ms were applied using ECM830 Square Wave Electroporation System (Harvard Apparatus, MA) (Fig. 1). After transfection discs were cultured for 72 h to allow expression of GFP or GDF6. Discs were then fixed, cryosectioned and analysed by immunofluorescence against GDF6. Results: We successfully transfected bovine NP and AF cells in monolayer culture with the two plasmids using a 1,400 V, 20 ms and 2 pulses with a *25 % efficiency using 0.15 M cells and 3 lg DNA (Fig. 1). Organ IVD culture transfection revealed GFP6 positive staining in the centre of the disc using 2-needle array electrode. Results from tweezertrodes did not show any GFP posi- tive cells. Conclusions: We identified novel parameters to successfully transfect primary bovine IVD cells. For transfection of whole IVD explants electroporation parameters need to be further optimized. Acknowledgments: This study was supported by the Lindenhof Foundation ‘‘Forschung und Lehre’’ (Project no. 13-02-F). References 1. Roughly PJ (2004) Spine (Phila) 29:2691–2699 2. 3. Clarke LE, McConell JC, Sherratt MJ, Derby B, Richardson SM, Hoyland JA (2014) Arthritis Res Ther 16:R67 Chan SC, Gantenbein-Ritter B (2012) J Vis Exp 60(60):e3490
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Neospora caninum is an intracellular parasite that causes major economic impact on cattle raising farms, and infects a wide range of warm-blooded hosts worldwide. Innate immune mechanisms that lead to protection against this parasite are still unknown. In order to investigate whether myeloid differentiation factor 88 (MyD88) is required for resistance against N. caninum, genetically deficient mice (MyD88(-/-)) and wild type littermates were infected with live tachyzoites and the resistance to infection was evaluated. We found that sub-lethal tachyzoite doses induced acute mortality of MyD88(-/-) mice, which succumbed to infection due to uncontrolled parasite replication. Higher parasitism in MyD88(-/-) mice was associated with the lack of IL-12 production by dendritic cells, delayed IFN-gamma responses by NKT, CD4(+) and CD8(+) T lymphocytes, and production of high levels of IL-10. MyD88(-/-) mice replenished with IL-12 and IFN-gamma abolished susceptibility as the animals survived throughout the experimental period. We conclude that protective IFN-gamma-mediated immunity to N. caninum is dependent on initial MyD88 signaling, in a mechanism triggered by production of IL-12 by dendritic cells. Further knowledge on Toll-like receptor recognition of N. caninum antigens is encouraged, since it could generate new prophylactic and therapeutic tools to control parasite burden.
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RATIONALE: The myeloid differentiation factor (MyD)88/interleukin (IL)-1 axis activates self-antigen-presenting cells and promotes autoreactive CD4(+) T-cell expansion in experimental autoimmune myocarditis, a mouse model of inflammatory heart disease. OBJECTIVE: The aim of this study was to determine the role of MyD88 and IL-1 in the progression of acute myocarditis to an end-stage heart failure. METHODS AND RESULTS: Using alpha-myosin heavy chain peptide (MyHC-alpha)-loaded, activated dendritic cells, we induced myocarditis in wild-type and MyD88(-/-) mice with similar distributions of heart-infiltrating cell subsets and comparable CD4(+) T-cell responses. Injection of complete Freund's adjuvant (CFA) or MyHC-alpha/CFA into diseased mice promoted cardiac fibrosis, induced ventricular dilation, and impaired heart function in wild-type but not in MyD88(-/-) mice. Experiments with chimeric mice confirmed the bone marrow origin of the fibroblasts replacing inflammatory infiltrates and showed that MyD88 and IL-1 receptor type I signaling on bone marrow-derived cells was critical for development of cardiac fibrosis during progression to heart failure. CONCLUSIONS: Our findings indicate a critical role of MyD88/IL-1 signaling in the bone marrow compartment in postinflammatory cardiac fibrosis and heart failure and point to novel therapeutic strategies against inflammatory cardiomyopathy.
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Neuregulin, or neu differentiation factor, induces cell proliferation or differentiation through interaction with members of the ErbB family of receptor tyrosine kinases. We report that neuregulin can also induce profound morphogenic responses in cultured epithelial cells of different origins. These effects include scattering of small epithelial islands and rearrangement of larger cell islands into ordered ring-shaped arrays with internal lumens. The ring-forming cells are interconnected by cadherin- and β-catenin-containing adherens junctions. In confluent cultures, neuregulin treatment induces formation of circular lumenlike gaps in the monolayer. Both cell scattering and ring formation are accompanied by a marked increase in cell motility that is independent of hepatocyte growth factor/scatter factor and its receptor (c-Met). Affinity-labeling experiments implied that a combination of ErbB-2 with ErbB-3 mediates the morphogenic signal of neuregulin in gastric cells. Indeed, a similar morphogenic effect could be reconstituted in nonresponsive cells by coexpression of ErbB-2 and -3. We conclude that a heterodimer between the kinase-defective neuregulin receptor, ErbB-3, and the coreceptor, ErbB-2, mediates the morphogenetic action of neuregulin.
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The Posttraumatic Growth Inventory (PTGI) is frequently used to assess positive changes following a traumatic event. The aim of the study is to examine the factor structure and the latent mean invariance of PTGI. A sample of 205 (M age = 54.3, SD = 10.1) women diagnosed with breast cancer and 456 (M age = 34.9, SD = 12.5) adults who had experienced a range of adverse life events were recruited to complete the PTGI and a socio-demographic questionnaire. We use Confirmatory Factor Analysis (CFA) to test the factor-structure and multi-sample CFA to examine the invariance of the PTGI between the two groups. The goodness of fit for the five-factor model is satisfactory for breast cancer sample (χ2(175) = 396.265; CFI = .884; NIF = .813; RMSEA [90% CI] = .079 [.068, .089]), and good for non-clinical sample (χ2(172) = 574.329; CFI = .931; NIF = .905; RMSEA [90% CI] = .072 [.065, .078]). The results of multi-sample CFA show that the model fit indices of the unconstrained model are equal but the model that uses constrained factor loadings is not invariant across groups. The findings provide support for the original five-factor structure and for the multidimensional nature of posttraumatic growth (PTG). Regarding invariance between both samples, the factor structure of PTGI and other parameters (i.e., factor loadings, variances, and co-variances) are not invariant across the sample of breast cancer patients and the non-clinical sample.
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Activation of dendritic cells (DC) by microbial products via Toll-like receptors (TLR) is instrumental in the induction of immunity. In particular, TLR signaling plays a major role in the instruction of Th1 responses. The development of Th2 responses has been proposed to be independent of the adapter molecule myeloid differentiation factor 88 (MyD88) involved in signal transduction by TLRs. In this study we show that flagellin, the bacterial stimulus for TLR5, drives MyD88-dependent Th2-type immunity in mice. Flagellin promotes the secretion of IL-4 and IL-13 by Ag-specific CD4(+) T cells as well as IgG1 responses. The Th2-biased responses are associated with the maturation of DCs, which are shown to express TLR5. Flagellin-mediated DC activation requires MyD88 and induces NF-kappaB-dependent transcription and the production of low levels of proinflammatory cytokines. In addition, the flagellin-specific response is characterized by the lack of secretion of the Th1-promoting cytokine IL-12 p70. In conclusion, this study suggests that flagellin and, more generally, TLR ligands can control Th2 responses in a MyD88-dependent manner.
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Oncogenesis is closely linked to abnormalities in cell differentiation. Notch signaling provides an important form of intercellular communication involved in cell fate determination, stem cell potential and differentiation. Here we review the role of this pathway in the integrated growth/differentiation control of the keratinocyte cell type, and the maintenance of normal skin homeostasis. In parallel with the pro-differentiation function of Notch1 in keratinocytes, we discuss recent evidence pointing to a tumor suppressor function of this gene in both mouse skin and human cervical carcinogenesis. The possibility that Notch signaling elicits signals with a duality of growth positive and negative function will be discussed.
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In recent years, exciting progress has been made towards unravelling the complex intraovarian control mechanisms that, in concert with systemic signals, coordinate the recruitment, selection and growth of follicles from the primordial stage through to ovulation and corpus luteum formation. A plethora of growth factors, many belonging to the transforming growth factor-beta (TGF-beta) superfamily, are expressed by ovarian somatic cells and oocytes in a developmental, stage-related manner and function as intraovarian regulators of folliculogenesis. Two such factors, bone morphogenetic proteins, RMP-4 and BMP-7, are expressed by ovarian stromal cells and/or theca cells and have recently been implicated as positive regulators of the primordial-to-primary follicle transition. In contrast, evidence indicates a negative role for anti-Mullerian hormone (AMH, also known as Mullerian-inhibiting substance) of pre-granulosa/granulosa cell origin in this key event and subsequent progression to the antral stage. Two other TGF-beta superfamily members, growth and differentiation factor-9 (GDF-9) and BMP-15 (also known as GDF-9B) are expressed in an oocyte-specific manner from a very early stage and play key roles in promoting follicle growth beyond the primary stage; mice with null mutations in the gdf-9 gene or ewes with inactivating mutations in gdf-9 or bmp-15 genes are infertile with follicle development arrested at the primary stage. Studies on later stages of follicle development indicate positive roles for granulosa cell-derived activin, BMP-2, -5 and -6, theca cell-derived BMP-2, -4 and -7 and oocyte-derived BMP-6 in promoting granulosa cell proliferation, follicle survival and prevention of premature luteinization and/or atresia. Concomitantly, activin, TGF-beta and several BMPs may exert paracrine actions on theca cells to attenuate LH-dependent androgen production in small to medium-size antral follicles. Dominant follicle selection in monovular species may depend on differential FSH sensitivity amongst a growing cohort of small antral follicles. Changes in intrafollicular activins, GDF-9, AMH and several BMPs may contribute to this selection process by modulating both FSH- and IGF-dependent signalling pathways in granulosa cells. Activin may also play a positive role in oocyte maturation and acquisition of developmental competence. in addition to its endocrine role to suppress FSH secretion, increased output of inhibin by the selected dominant follicle(s) may upregulate LH-induced androgen secretion that is required to sustain a high level of oestradiol secretion during the pre-ovulatory phase. Advances in our understanding of intraovarian regulatory mechanisms should facilitate the development of new approaches for monitoring and manipulating ovarian function and improving fertility in domesticated livestock, endangered species and man.
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Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)
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The myeloid differentiation factor 88 (MyD88) plays a pivotal role in Toll-like receptor (TLR)- and interleukin-1 receptor (IL-1R)-induced osteoclastogenesis. We examined the role of MyD88 on p38 mitogen-activated protein kinase (MAPK) and nuclear factor kappa-light-chain-enhancer of activated B cell (NF-κB) activation and nucleotide-binding oligomerization domain (Nod) induction by lipopolysaccharide (LPS) and IL-1 beta, and their effect on receptor activator of NF-κB ligand (RANKL) and osteoprotegerin (OPG) production in bone marrow stromal cell (BMSC). RANKL, Nod1, Nod2, NF-κB, and p38 protein levels were determined by Western blot. Nod2 was stimulated with muramyl dipeptide (MDP) prior to TLR4 stimulation with LPS. MyD88 deficiency markedly inhibited RANKL expression after LPS stimulation and increased OPG messenger RNA (mRNA) production. Also, MyD88 was necessary for NF-κB and p38 MAPK activation. MDP alone did not induce RANKL and OPG expressions; however, when combined with LPS, their expressions were significantly increased (p < 0.05). Our results support that MyD88 signaling has a pivotal role in osteoclastogenesis thought NF-κB and p38 activation. Nod2 and especially Nod1 levels were influenced by MyD88.
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Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)
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Nonsyndromic cleft lip with or without cleft palate (NSCLP) is a common birth anomaly that requires prolonged multidisciplinary rehabilitation. Although variation in several genes has been identified as contributing to NSCLP, most of the genetic susceptibility loci have yet to be defined. To identify additional contributory genes, a high-throughput genomic scan was performed using the Illumina Linkage IVb Panel platform. We genotyped 6008 SNPs in nine non-Hispanic white NSCLP multiplex families and a single large African-American NSCLP multiplex family. Fourteen chromosomal regions were identified with LOD>1.5, including six regions not previously reported. Analysis of the data from the African-American and non-Hispanic white families revealed two likely chromosomal regions: 8q21.3-24.12 and 22q12.2-12.3 with LOD scores of 2.98 and 2.66, respectively. On the basis of biological function, syndecan 2 (SDC2) and growth differentiation factor 6 (GDF6) in 8q21.3-24.12 and myosin heavy-chain 9, non-muscle (MYH9) in 22q12.2-12.3 were selected as candidate genes. Association analyses from these genes yielded marginally significant P-values for SNPs in SDC2 and GDF6 (0.01