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‣ Efeitos da resistencia periferica a insulina e do diabetes na prostata ventral de ratos; Effects of peripheral insulin resistance and diabetes in the rat ventral prostate

Daniele Lisboa Ribeiro
Fonte: Biblioteca Digital da Unicamp Publicador: Biblioteca Digital da Unicamp
Tipo: Tese de Doutorado Formato: application/pdf
Publicado em 30/05/2008 Português
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O diabetes mellitus leva a complicações em diversos órgãos, incluindo as glândulas acessórias do sistema genital masculino. Na próstata, é bem estabelecido que essa doença acarreta atrofia epitelial, mas ainda não é claro o seu efeito sobre os componentes estromais e sua associação com alterações patológicas. Esse estudo visa esclarecer três aspectos controversos referentes ao impacto do diabetes sobre a próstata: 1) como as condições metabólicas do diabetes crônico não tratado afeta o compartimento estromal, em especial os componentes da matriz extracelular; 2) as possíveis associações entre essa doença e a incidência de alterações neoplásicas e 3) examinar as alterações prostáticas causadas pela resistência à insulina em comparação com o diabetes. A resistência à insulina, induzida pela administração do glicocorticóide dexametasona (1mg mg/Kg pc, durante 5 dias) causa, em curto prazo, efeitos semelhantes aos do diabetes, tais como a atrofia epitelial e alteração fenotípica das células musculares lisas (cml). Contudo, esta situação difere do diabetes pela atrofia das cml e ativação dos fibroblastos. Os efeitos do diabetes (90 dias), induzido experimentalmente pela administração de aloxana (45 mg/Kg pc)...

‣ Tumorigenic conversion of immortal human keratinocytes through stromal cell activation

Skobe, Mihaela; Fusenig, Norbert E.
Fonte: The National Academy of Sciences Publicador: The National Academy of Sciences
Tipo: Artigo de Revista Científica
Publicado em 03/02/1998 Português
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The stromal microenvironment plays a crucial role in tumor development and progression. One of the most potent activators of stromal cells is the platelet-derived growth factor (PDGF). To investigate the role of PDGF in epithelial tumor development we stably transfected immortal nontumorigenic human keratinocytes with the PDGF-B cDNA. Transfected HaCaT cells overexpressed PDGF-B but remained negative for the PDGF receptors α and β (mRNA). Thus, they did not exhibit autocrine growth stimulation in vitro, but proliferation of cocultured fibroblasts was enhanced and this effect was inhibited by a neutralizing antibody to PDGF-BB. After subcutaneous injection into nude mice the transfected cells maintained high PDGF expression and formed progressively enlarging, rapidly proliferating cysts, classified as benign tumors. During early tumor development (up to 2 months), PDGF-B transfectants induced marked mesenchymal cell proliferation and angiogenesis, yet this effect vanished at later stages (2–6 months) concomitantly with increased epithelial cell proliferation and enhanced tumor growth. These results demonstrate that an activated stromal environment can promote tumorigenic conversion of nontumorigenic keratinocytes by inducing sustained epithelial hyperproliferation. This effect is apparently caused by a dual action of PDGF-BB: (i) PDGF-BB can promote tumor growth by inducing angiogenesis and stroma formation...

‣ Modulated Expression of the Epidermal Growth Factor-Like Homeotic Protein dlk Influences Stromal-Cell–Pre-B-Cell Interactions, Stromal Cell Adipogenesis, and Pre-B-Cell Interleukin-7 Requirements

Bauer, Steven R.; Ruiz-Hidalgo, María José; Rudikoff, Eva K.; Goldstein, Julia; Laborda, Jorge
Fonte: American Society for Microbiology Publicador: American Society for Microbiology
Tipo: Artigo de Revista Científica
Publicado em /09/1998 Português
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A close relationship exists between adipocyte differentiation of stromal cells and their capacity to support hematopoiesis. The molecular basis for this is unknown. We have studied whether dlk, an epidermal growth factor-like molecule that intervenes in adipogenesis and fetal liver hematopoiesis, affects both stromal cell adipogenesis and B-cell lymphopoiesis in an established pre-B-cell culture system. Pre-B-cell cultures require both soluble interleukin-7 (IL-7) and interactions with stromal cells to promote cell growth and prevent B-cell maturation or apoptosis. We found that BALB/c 3T3 fibroblasts express dlk and function as stromal cells. Transfection of these cells with antisense dlk decreased dlk expression and increased insulin-induced adipocytic differentiation. When antisense transfectants were used as stroma, IL-7 was no longer required to support the growth of pre-B cells and prevent maturation or apoptosis. Antisense dlk transfectants of S10 stromal cells also promoted pre-B-cell growth in the absence of IL-7. These results show that modulation of dlk on stromal cells can influence their adipogenesis and the IL-7 requirements of the pre-B cells growing in contact with them. These results indicate that dlk influences differentiation signals directed both to the stromal cells and to the lymphocyte precursors...

‣ Interleukin 7 production and function in stromal cell-dependent B cell development

Fonte: The Rockefeller University Press Publicador: The Rockefeller University Press
Tipo: Artigo de Revista Científica
Publicado em 01/07/1989 Português
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The role of IL-7 in the stromal cell-dependent B cell development was investigated using two stromal cell clones, ST2 and PA6; the former supports B lymphopoiesis while the latter can not. We demonstrate here that: (a) the ability of the stromal cell clone to produce IL-7 correlates well with the stromal cell activity to support B lymphopoiesis; (b) IL-7 production by ST2 is inducible rather than constitutive; (c) the IL-7-dependent B cell itself is a potent inducer of IL-7 production by ST2; (d) addition of rIL-7 to the PA6 layer renders this in vitro environment B lymphopoietic; and (e) the differentiation from early B progenitor to pre-B cell requires both IL- 7 and other stromal cell molecule(s) yet to be identified.

‣ One synchronous wave of B cell development in mouse fetal liver changes at day 16 of gestation from dependence to independence of a stromal cell environment

Fonte: The Rockefeller University Press Publicador: The Rockefeller University Press
Tipo: Artigo de Revista Científica
Publicado em 01/12/1989 Português
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Precursor cells of the B lineage can be enriched from mouse fetal liver by FACS with the aid of the pre-B cell-specific mAb G-5-2. The cells are concomitantly enriched for cells expressing the pre-B cell-specific gene lambda 5, and for cells developing to LPS-reactive mature B cells. The enriched purified precursors are not influenced by rIL-2 through - 7, alone or in combination, to develop to mitogen-reactive, sIg+ cells. Marginal proliferation of the precursors is observed in response to IL- 3 plus -4, and IL-6 plus -7, and this does not change in the presence of stromal cells. Development to mitogen-reactive, sIg+ cells is dependent on interactions with embryonic stromal cells from fetal liver. Two mAbs raised against the stromal cells inhibit this development. Two phases of precursor cell development can be distinguished in fetal liver. Between days 13 and 15 of gestation, it is dependent on stromal cell interactions, thereafter, from days 16 to 19, it is independent. A sudden increase in the number of mitogen- reactive, sIg+ B lineage cells occurs within 24 h between days 16 and 17. All these results indicate that B cell development occurs in one wave with synchronous steps of changes from a mitogen-insensitive, sIg- , stromal cell dependent to a mitogen-reactive...

‣ Human Prostate Stromal Cells Stimulate Increased PSA Production in DHEA-treated Prostate Cancer Epithelial Cells

Arnold, Julia T.; Gray, Nora E.; Jacobowitz, Ketzela; Viswanathan, Lavanya; Cheung, Pui W.; McFann, Kimberly K.; Le, Hanh; Blackman, Marc R.
Fonte: PubMed Publicador: PubMed
Tipo: Artigo de Revista Científica
Português
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Dehydroepiandrosterone (DHEA) is commonly used as a dietary supplement and may affect prostate pathophysiology when metabolized to androgens and/or estrogens. Human prostate LAPC-4 cancer cells with a wild type androgen receptor (AR), were treated with DHEA, androgens (DHT, T, or R1881), and E2 and assayed for PSA protein and gene expression. In LAPC-4 monocultures, DHEA and E2 induced little or no increase in PSA protein or mRNA expression compared to androgen-treated cells. When prostate cancer-associated (6S) stromal cells were added in coculture, DHEA stimulated LAPC-4 cell PSA protein secretion to levels approaching induction by DHT. Also, DHEA induced 15-fold more PSA mRNA in LAPC-4 cocultures than in monocultures. LAPC-4 proliferation was increased 2–3 fold when cocultured with 6S stromal cells regardless of hormone treatment. DHEA-treated 6S stromal cells exhibited a dose- and time-dependent increase in T secretion, demonstrating stromal cell metabolism of DHEA to T. Coculture with non-cancerous stroma did not induce LAPC-4 PSA production, suggesting a differential modulation of DHEA effect in a cancer-associated prostate stromal environment. This coculture model provides a research approach to reveal detailed endocrine, intracrine...

‣ An absence of stromal caveolin-1 is associated with advanced prostate cancer, metastatic disease and epithelial Akt activation

Di Vizio, Dolores; Morello, Matteo; Sotgia, Federica; Pestell, Richard G.; Freeman, Michael R.; Lisanti, Michael P.
Fonte: PubMed Publicador: PubMed
Tipo: Artigo de Revista Científica
Português
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Here, we examined the status of stromal Cav-1 expression in patients with benign prostatic hypertrophy (BPH), primary prostate cancers (PCa), and prostate-cancer metastases (Mets). Interestingly, an absence of stromal Cav-1 directly correlated with prostate cancer disease progression. For example, virtually all BPH samples showed abundant stromal Cav-1 immunostaining. In contrast, in a subset of patients with primary prostate cancer, the stromal levels of Cav-1 were significantly decreased, and this correlated with a high Gleason score, indicative of a worse prognosis and poor clinical outcome. Remarkably, all metastatic tumors (either from lymph node or bone) were completely negative for stromal Cav-1 staining. Thus, stromal Cav-1 expression may be considered as a new biomarker of prostate cancer disease progression and metastasis. Mechanistically, stromal Cav-1 levels were inversely correlated with the epithelial expression levels of Cav-1 and epithelial phospho-Akt. Thus, loss of stromal Cav-1 is predictive of elevated levels of epithelial Cav-1 and epithelial Akt-activation. This provides important new clinical evidence for paracrine signaling between prostate cancer epithelial cells and the tumor stromal micro-environment, especially related to disease progression and metastasis.

‣ Identification of stromal proteins overexpressed in nodular sclerosis Hodgkin lymphoma

Kischel, Philippe; Waltregny, David; Greffe, Yannick; Mazzucchelli, Gabriel; De Pauw, Edwin; de Leval, Laurence; Castronovo, Vincent
Fonte: BioMed Central Publicador: BioMed Central
Tipo: Artigo de Revista Científica
Publicado em 05/10/2011 Português
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Hodgkin lymphoma (HL) represents a category of lymphoid neoplasms with unique features, notably the usual scarcity of tumour cells in involved tissues. The most common subtype of classical HL, nodular sclerosis HL, characteristically comprises abundant fibrous tissue stroma. Little information is available about the protein composition of the stromal environment from HL. Moreover, the identification of valid protein targets, specifically and abundantly expressed in HL, would be of utmost importance for targeted therapies and imaging, yet the biomarkers must necessarily be accessible from the bloodstream. To characterize HL stroma and to identify potentially accessible proteins, we used a chemical proteomic approach, consisting in the labelling of accessible proteins and their subsequent purification and identification by mass spectrometry. We performed an analysis of potentially accessible proteins in lymph node biopsies from HL and reactive lymphoid tissues, and in total, more than 1400 proteins were identified in 7 samples. We have identified several extracellular matrix proteins overexpressed in HL, such as versican, fibulin-1, periostin, and other proteins such as S100-A8. These proteins were validated by immunohistochemistry on a larger series of biopsy samples...

‣ Stromal control of cystine metabolism promotes cancer cell survival in chronic lymphocytic leukemia

Zhang, Wan; Trachootham, Dunyaporn; Liu, Jinyun; Chen, Gang; Pelicano, Helene; Garcia-Prieto, Celia; Lu, Weiqin; Burger, Jan A; Croce, Carlo M; Plunkett, William; Keating, Michael J; Huang, Peng
Fonte: PubMed Publicador: PubMed
Tipo: Artigo de Revista Científica
Publicado em 19/02/2012 Português
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Tissue stromal cells interact with leukemia cells and profoundly affect their viability and drug sensitivity. Here we show a biochemical mechanism by which bone marrow stromal cells modulate the redox status of chronic lymphocytic leukemia (CLL) cells and promote cellular survival and drug resistance. Primary CLL cells from patients exhibit limited ability to transport cystine for glutathione (GSH) synthesis due to a low expression of Xc- transporter, while bone marrow stromal cells effectively import cystine and convert it to cysteine, which is then released into the microenvironment for uptake by CLL cells to promote GSH synthesis. The elevated GSH enhances leukemia cell survival and protects them from drug-induced cytotoxicity. Furthermore, disabling this protective mechanism significantly sensitizes CLL cells to drug treatment in stromal environment. This stromal-leukemia interaction is critical for CLL cell survival and represents a key biochemical pathway for effectively targeting leukemia cells to overcome drug resistance in vivo.

‣ Effect of AGM and Fetal Liver-Derived Stromal Cell Lines on Globin Expression in Adult Baboon (P. anubis) Bone Marrow-Derived Erythroid Progenitors

Lavelle, Donald; Vaitkus, Kestutis; Ruiz, Maria Armila; Ibanez, Vinzon; Kouznetsova, Tatiana; Saunthararajah, Yogen; Mahmud, Nadim; DeSimone, Joseph
Fonte: Public Library of Science Publicador: Public Library of Science
Tipo: Artigo de Revista Científica
Publicado em 31/05/2012 Português
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This study was performed to investigate the hypothesis that the erythroid micro-environment plays a role in regulation of globin gene expression during adult erythroid differentiation. Adult baboon bone marrow and human cord blood CD34+ progenitors were grown in methylcellulose, liquid media, and in co-culture with stromal cell lines derived from different developmental stages in identical media supporting erythroid differentiation to examine the effect of the micro-environment on globin gene expression. Adult progenitors express high levels of γ-globin in liquid and methylcellulose media but low, physiological levels in stromal cell co-cultures. In contrast, γ-globin expression remained high in cord blood progenitors in stromal cell line co-cultures. Differences in γ-globin gene expression between adult progenitors in stromal cell line co-cultures and liquid media required cell-cell contact and were associated with differences in rate of differentiation and γ-globin promoter DNA methylation. We conclude that γ-globin expression in adult-derived erythroid cells can be influenced by the micro-environment, suggesting new potential targets for HbF induction.

‣ Enhanced Immunoreactivity of TIMP-2 in the Stromal Compartment of Tumor as a Marker of Favorable Prognosis in Ovarian Cancer Patients

Hałoń, Agnieszka; Nowak-Markwitz, Ewa; Donizy, Piotr; Matkowski, Rafał; Maciejczyk, Adam; Gansukh, Tserenchunt; Györffy, Balázs; Spaczyński, Marek; Zabel, Maciej; Lage, Hermann; Surowiak, Paweł
Fonte: SAGE Publications Publicador: SAGE Publications
Tipo: Artigo de Revista Científica
Publicado em /07/2012 Português
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Degradation of the extracellular matrix and basement membrane is a critical step in tumor progression. Matrix metalloproteinase 2 (MMP-2) and tissue inhibitor of metalloproteinase 2 (TIMP 2) act in a coordinated manner to form an integrated system involved in ovarian cancer (OC) progression. In this study, the authors describe the expression of TIMP-2 detected by immunohistochemistry in 6 OC cell lines and in 43 malignant epithelial ovarian tumors (in tumor and stromal compartments) in sections originating from primary laparotomies. No significant correlations between overall and progression-free survival and TIMP-2 expression in tumor compartment were observed. The analysis demonstrated a significant association between enhanced stromal expression of TIMP-2 and better clinical response to cisplatin- and paclitaxel-based chemotherapy. Increased expression of TIMP-2 in the stromal compartment and simultaneous overexpression in both stromal and tumor compartments strongly correlated with increased survival. No significant correlations were found in vitro between resistance to cisplatin, paclitaxel, or topotecan and the expression of TIMP-2 in the OC cell lines, suggesting stromal influences on tumor chemoresistance in the physiological environment. This study supports the concept of TIMP-2 expression in the stromal compartment of OC as a promising marker of prognosis and response to cisplatin- and paclitaxel-based chemotherapy in OC patients.

‣ Stromal myofibroblasts in oral leukoplakia and oral squamous cell carcinoma

de-Assis, Eliene M.; Pimenta, Luiz G.G.S.; Costa-e-Silva, Edson; Souza, Paulo E.A.; Horta, Martinho C.R.
Fonte: Medicina Oral S.L. Publicador: Medicina Oral S.L.
Tipo: Artigo de Revista Científica
Português
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Objectives: Oral leukoplakia (OL) is the main potentially malignant disorder and oral squamous cell carcinoma (OSCC) is the most common malignancy of the oral mucosa. Stromal myofibroblasts play an important role in tumor invasion and metastasis, due to its ability to modify the extracellular matrix. This study aimed to evaluate the presence of stromal myofibroblasts in OL and OSCC. Differences in the presence of myofibroblasts among OL with distinct grades of epithelial dysplasia as well as between histologically high- and low-invasive OSCC were also assessed. Study Design: A total of 30 OL and 41 OSCC from archival formalin-fixed, paraffin-embedded specimens were evaluated. 10 samples of normal oral mucosa were used as a control. Myofibroblasts were identified by immunohistochemical detection of alpha smooth muscle actin and its presence was classified as negative, scanty or abundant. Differences in the presence of myofibroblasts among OL with distinct grades of epithelial dysplasia as well as between high- and low-invasive OSCC were analyzed using the Mann-Whitney test. Results: Myofibroblasts were not detected in normal oral mucosa and OL, whatever its histological grade. In OSCC, the presence of stromal myofibroblasts was classified as negative in 11 (26.8%)...

‣ Corneal Stromal Cell Plasticity: In Vitro Regulation of Cell Phenotype Through Cell-Cell Interactions in a Three-Dimensional Model

Wilson, Samantha L.; Yang, Ying; El Haj, Alicia J.
Fonte: Mary Ann Liebert, Inc. Publicador: Mary Ann Liebert, Inc.
Tipo: Artigo de Revista Científica
Português
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In vivo, epithelial cells are connected both anatomically and functionally with stromal keratocytes. Co-culturing aims at recapturing this cellular anatomy and functionality by bringing together two or more cell types within the same culture environment. Corneal stromal cells were activated to their injury phenotype (fibroblasts) and expanded before being encapsulated in type I collagen hydrogels constructs. Three different epithelial-stromal co-culture methods were then examined: epithelial explant; transwell; and the use of conditioned media. The aim was to determine whether the native, inactivated keratocyte cell phenotype could be restored in vitro. Media supplementation with transforming growth factor beta-1 (TGF-β1) was then used to determine whether the inactivated stromal cells retained their plasticity in vitro and could be re-activated to the fibroblast phenotype. Finally, media supplementation with wortmannin was used to inhibit epithelial–stromal cell interactions. Two different nondestructive techniques, spherical indentation and optical coherence tomography, were used to reveal how epithelial-stromal co-culturing with TGF-β1, and wortmannin media supplementation, respectively, affect stromal cell behavior and differentiation in terms of construct contraction and elastic modulus measurement. Cell viability...

‣ Tumour–stromal interactions generate emergent persistence in collective cancer cell migration

Chang, William K.; Carmona-Fontaine, Carlos; Xavier, Joao B.
Fonte: The Royal Society Publicador: The Royal Society
Tipo: Artigo de Revista Científica
Publicado em 06/08/2013 Português
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Cancer cell collective migration is a complex behaviour leading to the invasion of cancer cells into surrounding tissue, often with the aid of stromal cells in the microenvironment, such as macrophages or fibroblasts. Although tumour–tumour and tumour–stromal intercellular signalling have been shown to contribute to cancer cell migration, we lack a fundamental theoretical understanding of how aggressive invasion emerges from the synergy between these mechanisms. We use a computational self-propelled particle model to simulate intercellular interactions between co-migrating tumour and stromal cells and study the emergence of collective movement. We find that tumour–stromal interaction increases the cohesion and persistence of migrating mixed tumour–stromal cell clusters in a noisy and unbounded environment, leading to increased cell cluster size and distance migrated by cancer cells. Although environmental constraints, such as vasculature or extracellular matrix, influence cancer migration in vivo, our model shows that cell–cell interactions are sufficient to generate cohesive and persistent movement. From our results, we conclude that inhibition of tumour–stromal intercellular signalling may present a viable therapeutic target for disrupting collective cancer cell migration.

‣ Coordinated cytokine expression by stromal and hematopoietic cells during human osteoclast formation

Atkins, G.; Haynes, D.; Geary, S.; Loric, M.; Crotti, T.; Findlay, D.
Fonte: Elsevier Science Inc Publicador: Elsevier Science Inc
Tipo: Artigo de Revista Científica
Publicado em //2000 Português
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An in vitro culture system to generate human osteoclasts (OC) was recently described in which OC precursors in the human peripheral blood mononuclear cell (PBMC) population differentiate in the presence of murine ST-2 stromal cells. We used this culture system to define the cytokine environment in which human OC form and to determine the separate contributions of the stromal and hematopoietic elements. We designed a panel of reverse transcriptase-polymerase chain reaction (RT-PCR) primers that specifically amplify the respective murine or human mRNA species that correspond to cytokines and their cognate receptors previously shown to promote or inhibit OC differentiation. ST-2 cells were cocultured with human PBMC for up to 21 days in the presence of 1α,25(OH)2 vitamin D3, dexamethasone, and recombinant human macrophage-colony stimulating factor (M-CSF). OC formation was monitored by the appearance of cells that were positive for tartrate-resistant acid phosphatase (TRAP) and able to form resorption lacunae on slices of dentine. We found that the ST-2 cells in these cultures express messenger RNA (mRNA) encoding a repertoire of many of the reported osteoclastogenic factors (interleukins [IL]-1/IL-1R1, IL-11, IL-6/IL-6R, and IL-17 transforming growth factor [TGF]-β)...

‣ Haemopoietic cells influence stromal cell gene expression during human osteoclast development

Atkins, G.; Haynes, D.; Zannettino, A.; Capone, M.; Crotti, T.; Findlay, D.
Fonte: British Editorial Society of Bone and Joint Surgery Publicador: British Editorial Society of Bone and Joint Surgery
Tipo: Artigo de Revista Científica
Publicado em //2002 Português
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We have used a culture system of human peripheral blood mononuclear cells (PBMC)as a source of osteoclast (OC) precursors and murine stromal cells to define the cytokine environment in which human OC form, and to determine the separate contributions of the stromal and haemopoietic elements. We designed a panel of reverse transcription-polymerase chain reaction (RT-PCR) primers that specifically amplify the respective murine or human mRNA species that correspond to cytokines and their receptors previously shown to promote or inhibit OC formation. Murine ST-2 cells and human PBMC were cocultured for up to 21 days in the presence of 1,25(OH) 2vitD3, dexamethasone and human macrophage-colony stimulating factor (M-CSF). OC formation was monitored by the appearance of cells that were positive for tartrate resistant acid phosphatase and able to form resorption lacunae on slices of dentine. We found that the ST-2 cells in these cultures expressed mRNA encoding a repertoire of many of the reported osteoclastogenic factors, as well as the recently described OC differentiation factor (ODF/RANKL). The stromal cells also expressed mRNA encoding osteoprotegerin (OPG), a potent inhibitor of OC formation. We found that agonists and antagonists of OC formation were expressed by both the stromal cells and the PBMC. RANK...

‣ Incremental benefits of repeated mesenchymal stromal cell administration compared with solitary intervention after myocardial infarction

Richardson, J.D.; Psaltis, P.J.; Frost, L.; Paton, S.; Carbone, A.; Bertaso, A.G.; Nelson, A.J.; Wong, D.T.L.; Worthley, M.I.; Gronthos, S.; Zannettino, A.C.W.; Worthley, S.G.
Fonte: Elsevier Publicador: Elsevier
Tipo: Artigo de Revista Científica
Publicado em //2014 Português
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BACKGROUND AIMS: Traditionally, stem cell therapy for myocardial infarction (MI) has been administered as a single treatment in the acute or subacute period after MI. These time intervals coincide with marked differences in the post-infarct myocardial environment, raising the prospect that repeat cell dosing could provide incremental benefit beyond a solitary intervention. This prospect was evaluated with the use of mesenchymal stromal cells (MSCs). METHODS: Three groups of rats were studied. Single-therapy and dual-therapy groups received allogeneic, prospectively isolated MSCs (1 × 10(6) cells) by trans-epicardial injection immediately after MI, with additional dosing 1 week later in the dual-therapy cohort. Control animals received cryopreservant solution only. Left ventricular (LV) dimensions and ejection fraction (EF) were assessed by cardiac magnetic resonance immediately before MI and at 1, 2 and 4 weeks after MI. RESULTS: Immediate MSC treatment attenuated early myocardial damage with EF of 35.3 ± 3.1% (dual group, n = 12) and 35.2 ± 2.2% (single group, n = 15) at 1 week after MI compared with 22.1 ± 1.9% in controls (n = 17, P < 0.01). In animals receiving a second dose of MSCs, EF increased to 40.7 ± 3.1% by week 4...

‣ Decidualized and pre-decidualized normal endometrial stromal cells produce more O-linked N-acetylglucosamine containing epitope H than non-decidualized normal endometrial stromal cells

Polyzos, P.T.; Arvanitis, L.; Charchanti, A.; Galani, V.; Havaki, S.; Kallioras, V.; Nakou, María; Faros, E.G.; Marinos, E.; Sgantzos, M.; Kittas, C.
Fonte: Murcia : F. Hernández Publicador: Murcia : F. Hernández
Tipo: Artigo de Revista Científica Formato: application/pdf
Português
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The epitope H contains an O-linked Nacetylglucosamine residue in a specific conformation and/or environment recognized by the monoclonal antibody H (mAbH). mAbH stains two bands with Mr x10-3 of 209 and 62 in lysates of cultured rat astrocytes. In addition, in extracts of cultured MCF-7 breast carcinoma cell line cells it stains cytokeratin 8 and five polypeptides originating from Triton X-100-soluble (Mr x10-3 of 232, 67 and 37) and from the Triton X-100- insoluble (Mr x10-3 of 51 and 50) fractions, respectively. In our previous studies we used the mAbH to investigate by immunostaining the expression of the epitope H in normal human brains, human brains with a variety of lesions, astrocytic tumors, infiltrating ductal breast carcinomas, fibroadenomas, and mitochondria-rich normal, metaplastic and neoplastic cells. In order to gain further insight into the expression patterns of the epitope H in human tissues we used the mAbH to investigate the immunohistochemical expression of the epitope H in normal human endometrium, including 30 cases of proliferative endometrium, 30 cases of early secretory endometrium, 30 cases of mid secretory endometrium, 30 cases of late secretory endometrium and 30 cases of decidual tissues. The main results were the following: 1) The decidual stromal cells presented in all cases high cytoplasmic expression of the epitope H; 2) The predecidual stromal cells presented in all cases of late secretory endometrium significant cytoplasmic expression of the epitope H ranging from moderate to high expression; 3) The non pre-decidual stromal cells of the functional endometrial layer presented in all cases insignificant cytoplasmic expression of the epitope H ranging from null to low expression; 4) The stromal cells of the basal layer of the endometrium and decidua did not express the epitope H in any case; 5) The endometrial stromal granulocytes did not express the epitope H in any case and 6) The blood vessel wall cells (endothelial and smooth muscle) of the endometrium through the whole duration of the menstrual cycle and of the decidua presented high cytoplasmic expression of the epitope H. It is concluded that decidualized and predecidualized human normal endometrial stromal cells show increased expression of the O-linked Nacetylglucosamine containing epitope H compared to non-decidualized endometrial stromal cells. These findings suggest that the expression of the epitope H may be under positive progesteronic control in normal human endometrium. Further investigation of the antigens bearing the epitope H might help to gain further insight into the histophysiology and the pathology of human endometrium.

‣ Stromal and hematopoietic cells in secondary lymphoid organs: partners in immunity

Malhotra, Deepali; Fletcher, Anne L.; Turley, Shannon J.
Fonte: PubMed Publicador: PubMed
Tipo: Artigo de Revista Científica
Publicado em /01/2013 Português
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Secondary lymphoid organs (SLOs), including lymph nodes, Peyer's patches, and the spleen, have evolved to bring cells of the immune system together. In these collaborative environments, lymphocytes scan the surfaces of antigen-presenting cells for cognate antigens, while moving along stromal networks. The cell-cell interactions between stromal and hematopoietic cells in SLOs are therefore integral to the normal functioning of these tissues. Not only do stromal cells physically construct SLO architecture, but they are essential for regulating hematopoietic populations within these domains. Stromal cells interact closely with lymphocytes and dendritic cells, providing scaffolds on which these cells migrate, and recruiting them into niches by secreting chemokines. Within lymph nodes, stromal cell-ensheathed conduit networks transport small antigens deep into the SLO parenchyma. More recently, stromal cells have been found to induce peripheral CD8+ T-cell tolerance and control the extent to which newly activated T cells proliferate within lymph nodes. Thus, stromal-hematopoietic crosstalk has important consequences for regulating immune cell function within SLOs. In addition, stromal cell interactions with hematopoietic cells, other stroma...

‣ NOX4-dependent ROS production by stromal mammary cells modulates epithelial MCF-7 cell migration

Guerrero, Javier; Martínez, Jorge; Smith, Patricio C.; Tobar, Nicolás
Fonte: NATURE PUBLISHING GROUP Publicador: NATURE PUBLISHING GROUP
Tipo: Artículo de revista
Português
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BACKGROUND: The influence of the stromal microenvironment on the progression of epithelial cancers has been demonstrated. Unravelling the mechanisms by which stromal cells affect epithelial behaviour will contribute in understanding cellular malignancy. It has been proposed that redox environment has a role in the acquisition of malignancy. In this work, we studied the influence of epithelial cells on the stromal redox status and the consequence of this phenomenon on MCF-7 cell motility. METHODS: We analysed in a co-culture system, the effect of RMF-EG mammary stromal cells on the migratory capacity of MCF-7 cell line. To test whether the NOX-dependent stromal redox environment influences the epithelial migratory behaviour, we knocked down the expression of NOX4 using siRNA strategy. The effect of TGF-b1 on NOX4 expression and activity was analysed by qPCR, and intracellular ROS production was measured by a fluorescent method. RESULTS: Migration of MCF-7 breast epithelial cells was stimulated when co-cultured with RMF-EG cells. This effect depends on stromal NOX4 expression that, in turn, is enhanced by epithelial soluble factors. Pre-treatment of stromal cells with TGF-b1 enhanced this migratory stimulus by elevating NOX4 expression and intracellular ROS production. TGF-b1 seems to be a major component of the epithelial soluble factors that stimulate NOX4 expression. CONCLUSIONS: Our results have identified that an increased stromal oxidative status...