RESUMEN
The complex microenvironment that surrounds hematopoietic stem cells (HSCs) in the bone marrow niche involves different coordinated signaling pathways. The stem cells establish permanent interactions with distinct cell types such as mesenchymal stromal cells, osteoblasts, osteoclasts or endothelial cells and with secreted regulators such as growth factors, cytokines, chemokines and their receptors. These interactions are mediated through adhesion to extracellular matrix compounds also. All these signaling pathways are important for stem cell fates such as self-renewal, proliferation or differentiation, homing and mobilization, as well as for remodeling of the niche. Among these complex molecular cues, this review focuses on heparan sulfate (HS) structures and functions and on the role of enzymes involved in their biosynthesis and turnover. HS associated to core protein, constitute the superfamily of heparan sulfate proteoglycans (HSPGs) present on the cell surface and in the extracellular matrix of all tissues. The key regulatory effects of major medullar HSPGs are described, focusing on their roles in the interactions between hematopoietic stem cells and their endosteal niche, and on their ability to interact with Heparin Binding Proteins (HBPs). Finally, according to the relevance of HS moieties effects on this complex medullar niche, we describe recent data that identify HS mimetics or sulfated HS signatures as new glycanic tools and targets, respectively, for hematopoietic and mesenchymal stem cell based therapeutic applications.
Asunto(s)
Citocinas/química , Proteínas de la Matriz Extracelular/química , Células Madre Hematopoyéticas/química , Heparitina Sulfato/química , Células Madre Mesenquimatosas/química , Receptores de Citocinas/química , Animales , Materiales Biomiméticos/farmacología , Médula Ósea/fisiología , Conformación de Carbohidratos , Secuencia de Carbohidratos , Citocinas/metabolismo , Células Endoteliales/química , Células Endoteliales/metabolismo , Proteínas de la Matriz Extracelular/metabolismo , Células Madre Hematopoyéticas/efectos de los fármacos , Células Madre Hematopoyéticas/metabolismo , Heparitina Sulfato/clasificación , Heparitina Sulfato/metabolismo , Humanos , Células Madre Mesenquimatosas/efectos de los fármacos , Células Madre Mesenquimatosas/metabolismo , Osteoblastos/química , Osteoblastos/metabolismo , Osteoclastos/química , Osteoclastos/metabolismo , Unión Proteica , Receptores de Citocinas/metabolismo , Transducción de Señal , Nicho de Células Madre/fisiologíaRESUMEN
Electrospinning coupled with electrospraying provides a straightforward and robust route toward promising electrospun biocomposite scaffolds for bone tissue engineering. In this comparative investigation, four types of poly(3-hydroxybutyrate) (PHB)-based nanofibrous scaffolds were produced by electrospinning a PHB solution, a PHB/gelatin (GEL) mixture or a PHB/GEL/nHAs (hydroxyapatite nanoparticles) mixed solution, and by electrospinning a PHB/GEL solution and electrospraying a nHA dispersion simultaneously. SEM and TEM analyses demonstrated that the electrospun nHA-blended framework contained a majority of nHAs trapped within the constitutive fibers, whereas the electrospinning-electrospraying combination afforded fibers with a rough surface largely covered by the bioceramic. Structural and morphological characterizations were completed by FTIR, mercury intrusion porosimetry, and contact angle measurements. Furthermore, an in vitro investigation of human mesenchymal stromal cell (hMSC) adhesion and proliferation properties showed a faster cell development on gelatin-containing scaffolds. More interestingly, a long-term investigation of hMSC osteoblastic differentiation over 21 days indicate that hMSCs seeded onto the nHA-sprayed scaffold developed a significantly higher level of alkaline phosphatase activity, as well as a higher matrix biomineralization rate through the staining of the generated calcium deposits: the fiber surface deposition of nHAs by electrospraying enabled their direct exposure to hMSCs for an efficient transmission of the bioceramic osteoinductive and osteoconductive properties, producing a suitable biocomposite scaffold for bone tissue regeneration.
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Materiales Biocompatibles/síntesis química , Células Madre Mesenquimatosas/citología , Osteoblastos/citología , Osteogénesis/fisiología , Polímeros/síntesis química , Andamios del Tejido , Diferenciación Celular , Células Cultivadas , Electroquímica/métodos , Diseño de Equipo , Humanos , Ensayo de Materiales , Células Madre Mesenquimatosas/fisiología , Osteoblastos/fisiología , Prohibitinas , RotaciónRESUMEN
Glycosaminoglycans (GAGs) are essential components of the extracellular matrix, the natural environment from which cell behavior is regulated by a number or tissue homeostasis guarantors including growth factors. Because most heparin-binding growth factor activities are regulated by GAGs, structural and functional alterations of these polysaccharides may consequently affect the integrity of tissues during critical physiological and pathological processes. Here, we investigated whether the aging process can induce changes in the myocardial GAG composition in rats and whether these changes can affect the activities of particular heparin-binding growth factors known to sustain cardiac tissue integrity. Our results showed an age-dependent increase of GAG levels in the left ventricle. Biochemical and immunohistological studies pointed out heparan sulfates (HS) as the GAG species that increased with age. ELISA-based competition assays showed altered capacities of the aged myocardial GAGs to bind FGF-1, FGF-2, and VEGF but not HB EGF. Mitogenic assays in cultured cells showed an age-dependent decrease of the elderly GAG capacities to potentiate FGF-2 whereas the potentiating effect on VEGF(165) was increased, as confirmed by augmented angiogenic cell proliferation in Matrigel plugs. Moreover, HS disaccharide analysis showed considerably altered 6-O-sulfation with modest changes in N- and 2-O-sulfations. Together, these findings suggest a physiological significance of HS structural and functional alterations during aging. This can be associated with an age-dependent decline of the extracellular matrix capacity to efficiently modulate not only the activity of resident or therapeutic growth factors but also the homing of resident or therapeutic cells.
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Envejecimiento/metabolismo , Glicosaminoglicanos/metabolismo , Heparitina Sulfato/metabolismo , Péptidos y Proteínas de Señalización Intercelular/metabolismo , Miocardio/metabolismo , Envejecimiento/fisiología , Animales , Disacáridos/metabolismo , Factor 2 de Crecimiento de Fibroblastos/metabolismo , Glicosaminoglicanos/aislamiento & purificación , Ventrículos Cardíacos/metabolismo , Ventrículos Cardíacos/fisiopatología , Masculino , Ratas , Ratas Wistar , Factor A de Crecimiento Endotelial Vascular/metabolismoRESUMEN
Tissue engineering is a promising alternative to current full thickness circumferential esophageal replacement methods. The aim of our study was to develop a clinical grade Decellularized Human Esophagus (DHE) for future clinical applications. After decontamination, human esophagi from deceased donors were placed in a bioreactor and decellularized with sodium dodecyl sulfate (SDS) and ethylendiaminetetraacetic acid (EDTA) for 3 days. The esophagi were then rinsed in sterile water and SDS was eliminated by filtration on an activated charcoal cartridge for 3 days. DNA was removed by a 3-hour incubation with DNase. A cryopreservation protocol was evaluated at the end of the process to create a DHE cryobank. The decellularization was efficient as no cells and nuclei were observed in the DHE. Sterility of the esophagi was obtained at the end of the process. The general structure of the DHE was preserved according to immunohistochemical and scanning electron microscopy images. SDS was efficiently removed, confirmed by a colorimetric dosage, lack of cytotoxicity on Balb/3T3 cells and mesenchymal stromal cell long term culture. Furthermore, DHE did not induce lymphocyte proliferation in-vitro. The cryopreservation protocol was safe and did not affect the tissue, preserving the biomechanical properties of the DHE. Our decellularization protocol allowed to develop the first clinical grade human decellularized and cryopreserved esophagus.
Asunto(s)
Matriz Extracelular , Andamios del Tejido , Ratones , Animales , Humanos , Andamios del Tejido/química , Ingeniería de Tejidos/métodos , Criopreservación , Dodecil Sulfato de Sodio/química , EsófagoRESUMEN
Glioblastoma is the most common primary brain tumor in human adults. Since existing treatments are not effective enough, novel therapeutic targets must be sought. The heparin-binding growth factor, heparin affin regulatory peptide (HARP), also known as pleiotrophin (PTN), could potentially represent such a target. We have previously shown that a mutant protein, HARPDelta111-136, which lacks HARP's C-terminal 26 amino acids, acts as a dominant negative HARP effector by heterodimerizing with the wild-type growth factor. The aim of our study was to evaluate the potential inhibitory activity of HARPDelta111-136 on the U87 MG human glioblastoma cell line. By overexpressing the truncated form of HARP in stably established clones of U87 MG cells, we observed an inhibition of proliferation under both anchorage-dependent and anchorage-independent conditions. We confirmed these results in an in vivo subcutaneous tumor xenograft model. In addition, we found that HARPDelta111-136 inhibited cell proliferation in a paracrine manner. Analysis of key cellular pathways revealed a decrease of cell adhesion in U87 MG cells that overexpressed the mutant protein, which could explain this inhibitory effect. A replication-defective adenovirus model that encoded HARPDelta111-136 supported a putative antiproliferative role for the truncated protein in vitro and in vivo. Interestingly, HARPDelta111-136 was also able to abolish angiogenic activity in HUVEC proliferation and in a Matrigel plug assay. These results demonstrate that considering its antiproliferative and angiostatic effects, HARPDelta111-136 could be of great interest when used in conjunction with standard treatments.
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Neoplasias Encefálicas/patología , Proteínas Portadoras/genética , Citocinas/genética , Glioblastoma/patología , Mutación/genética , Proteínas Proto-Oncogénicas/genética , Animales , Apoptosis , Western Blotting , Neoplasias Encefálicas/genética , Neoplasias Encefálicas/metabolismo , Células CHO , Adhesión Celular , Movimiento Celular , Proliferación Celular , Colágeno/metabolismo , Cricetinae , Cricetulus , Combinación de Medicamentos , Ensayo de Inmunoadsorción Enzimática , Femenino , Regulación Neoplásica de la Expresión Génica/fisiología , Glioblastoma/genética , Glioblastoma/metabolismo , Humanos , Técnicas para Inmunoenzimas , Laminina/metabolismo , Ratones , Ratones Desnudos , Fragmentos de Péptidos/genética , Fragmentos de Péptidos/farmacología , Proteoglicanos/metabolismo , ARN Mensajero/genética , Reacción en Cadena de la Polimerasa de Transcriptasa Inversa , Células Tumorales Cultivadas , Ensayos Antitumor por Modelo de XenoinjertoRESUMEN
Angiogenesis assays based on in vitro capillary-like growth of endothelial cells (EC) are widely used, either to evaluate the effect of anti- and pro-angiogenesis drugs of interest, or to test and compare the functional capacities of various types of EC and progenitor cells. Among the different methods applied to study angiogenesis, the most commonly used is the "Endothelial Tube Formation Assay" (ETFA). In suitable culture conditions, EC form two-dimensional (2D) branched structures that can lead to a meshed pseudo-capillary network. An alternative approach to ETFA is the "Fibrin Bead Assay" (FBA), based on the use of Cytodex 3 microspheres, which promote the growth of 3D capillary-like patterns from coated EC, suitable for high throughput in vitro angiogenesis studies. The analytical evaluation of these two widely used assays still remains challenging in terms of observation method and image analysis. We previously developed the "Angiogenesis Analyzer" for ImageJ (AA), a tool allowing analysis of ETFA-derived images, according to characteristics of the pseudo-capillary networks. In this work, we developed and implemented a new algorithm for AA able to recognize microspheres and to analyze the attached capillary-like structures from the FBA model. Such a method is presented for the first time in fully automated mode and using non-destructive image acquisition. We detailed these two algorithms and used the new AA version to compare both methods (i.e. ETFA and FBA) in their efficiency, accuracy and statistical relevance to model angiogenesis patterns of Human Umbilical Vein EC (HUVEC). Although the two methods do not assess the same biological step, our data suggest that they display specific and complementary information on the angiogenesis processes analysis.
Asunto(s)
Morfogénesis/genética , Neovascularización Patológica/diagnóstico por imagen , Neovascularización Fisiológica/genética , Factor A de Crecimiento Endotelial Vascular/genética , Endotelio/crecimiento & desarrollo , Endotelio/metabolismo , Endotelio/patología , Fibrina/química , Células Endoteliales de la Vena Umbilical Humana , Humanos , Neovascularización Patológica/genética , Neovascularización Patológica/patologíaRESUMEN
BACKGROUND: Heparan sulfate (HS) proteoglycans (PG) may be found at the chondrocyte surface and in the pericellular cartilage matrix, and are involved in cell-cell and cell-matrix interactions. An important function of HS chains is to regulate cell fate through specific interactions with heparin-binding proteins (HBP) modulated by their complex sulfation pattern. Osteoarthritis (OA) is a joint disorder characterized by the degradation of articular cartilaginous extracellular matrix. The aim of this study was to investigate HS structure and functions in osteoarthritic cartilages compared to normal cartilages (controls). METHODS: Glycosaminoglycans (GAG) were extracted from human macroscopically normal cartilages (controls, n = 7) and (OA cartilages n = 11). HS were isolated and quantified using the DMMB quantification method. Their structure and functions were then compared using respectively a HPLC analysis and HBP binding tests and their phenotypic effects on murine chondrocytes were studied by RQ-PCR. Statistical analyzes were performed using a one-way ANOVA followed by a Dunnett's test or a t test for pairwise comparisons. RESULTS: In OA, HS were characterized by increased sulfation levels compared to controls. Moreover, the capacity of these HS to bind HBP involved in the OA pathophysiological process such as FGF2 and VEGF was reduced. Chondroitin sulfates and keratan sulfates regulated these binding properties. Finally, HS from OA cartilages induced the mRNA levels of catabolic markers such as MMP3, MMP13, and TS4 and inhibited the mRNA levels of anabolic markers such as COL2, ACAN, SOX9, and VEGF in murine articular chondrocytes. CONCLUSION: The sulfation of HS chains was increased in OA cartilages with changes in HBP binding properties and biological effects on chondrocyte phenotypes. Thus, modified HS present in altered cartilages could be a novel therapeutic target in OA.
Asunto(s)
Cartílago Articular , Osteoartritis , Animales , Condrocitos , Glicosaminoglicanos , Heparitina Sulfato , Humanos , RatonesRESUMEN
In pathologies of the esophagus such as esophageal atresia, cancers, and caustic injuries, methods for full thickness esophageal replacement require the sacrifice of healthy intra-abdominal organs such as the stomach and the colon and are associated with high morbidity, mortality, and poor functional results. To overcome these problems, tissue engineering methods are developed to create a substitute with scaffolds and cells. The aim of this study was to develop a simple and safe decellularization process in order to obtain a clinical grade esophageal extracellular matrix. Following the decontamination step, porcine esophagi were decellularized in a bioreactor with sodium dodecyl sulfate and ethylenediaminetetraacetic acid for 3 days and were rinsed with deionized water. DNA was eliminated by a 3-hr DNase treatment. To remove any residual detergent, the matrix was then incubated with an absorbing resin. The resulting porcine esophageal matrix was characterized by the assessment of the efficiency of the decellularization process (DNA quantification), evaluation of sterility and absence of cytotoxicity, and its composition and biomechanical properties, as well as the possibility to be reseeded with mesenchymal stem cells. Complete decellularization with the preservation of the general structure, composition, and biomechanical properties of the native esophageal matrix was obtained. Sterility was maintained throughout the process, and the matrix showed no cytotoxicity. The resulting matrix met clinical grade criteria and was successfully reseeded with mesenchymal stem cells..
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Esófago/química , Matriz Extracelular/química , Ensayo de Materiales , Células Madre Mesenquimatosas/metabolismo , Ingeniería de Tejidos , Andamios del Tejido/química , Animales , Células Madre Mesenquimatosas/citología , PorcinosRESUMEN
Malignant rhabdoid tumours (MRT) are highly aggressive cancers of early childhood that arise in different organs or tissues. The unifying criterion for these tumours is the presence of inactivating mutations of the hSNF5/INI1 tumour suppressor gene which encodes a core subunit of the chromatin remodelling SWI/SNF complex. Using a variety of markers we analysed the phenotypic traits of MON and DEV cell lines derived respectively from an undifferentiated abdominal MRT and from a brain MRT. DEV cells express spontaneously a wide range of neural and glial markers. It can be induced to differentiate into the neural lineage following hSNF5/INI1 expression with appearance of neurite processes, strong increase of neural markers and decrease of glial markers. A less pronounced neural differentiation is also observed with MON cells, which possess more primitive polyphenotypic features with positivity for markers from the three embryonic layers. Finally, we show that the neural differentiation of rat PC12 cells in the presence of nerve growth factor (NGF) is strongly impaired when hSNF5/INI1 expression is inhibited by RNA interference. Altogether these results indicate that hSNF5/INI1 is an essential subunit for SWI/SNF-dependant induction of neural differentiation programs. Further experiments should enable documentation of whether it provides instructive or permissive signals for differentiation.
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Transformación Celular Neoplásica/patología , Proteínas Cromosómicas no Histona/fisiología , Proteínas de Unión al ADN/fisiología , Genes Supresores de Tumor/fisiología , Tumor Rabdoide/patología , Factores de Transcripción/fisiología , Animales , Anticuerpos Antineoplásicos/fisiología , Western Blotting , Línea Celular Tumoral , Proteínas Cromosómicas no Histona/metabolismo , Proteínas de Unión al ADN/metabolismo , Citometría de Flujo , Ratones , Fenotipo , ARN Neoplásico , Proteína SMARCB1 , Factores de Transcripción/metabolismo , TransfecciónRESUMEN
BACKGROUND: Expansion protocols aim at both increasing the number of umbilical cord blood (UCB) hematopoietic stem cells and progenitor cells (HSPCs) and reducing the period of neutropenia in UCB HSPC graft. Because glycosaminoglycans (GAGs) are known to be important components of the hematopoietic niche and to modulate growth factor effects, we explored the use of GAG mimetic OTR4131 to potentiate HSPC's in vitro expansion and in vivo engraftment. METHODS: UCB CD34+ cells were expanded with serum-free medium, SCF, TPO, FLT3-lig and G-CSF during 12 days in the absence or the presence of increasing OTR4131 concentrations (0-100 µg/mL). Proliferation ratio, cell viability and phenotype, functional assays, migration capacity and NOD-scid/γc(-/-) mice engraftment were assessed after expansion. RESULTS: At Day 12, ratios of cell expansion were not significantly increased by OTR4131 treatment. Better total nucleated cell viability was observed with the use of 1 µg/mL GAG mimetic compared to control (89.6 % ± 3.7 % and 79.9 % ± 3.3 %, respectively). Phenotype analysis showed a decrease of monocyte lineage in the presence of OTR4131 and HSPC migration capacity was diminished when GAG mimetic was used at 10 µg/mL (10.9 % ± 4.1 % vs. 52.9 % ± 17.9 % for control). HSPC clonogenic capacities were similar whatever the culture conditions. Finally, in vivo experiments revealed that mice successfully engrafted in all conditions, even if some differences were observed during the first month. Three months after graft, bone marrow chimerism and blood subpopulations were similar in both groups. CONCLUSIONS: UCB HSPCs ex-vivo expansion in the presence of OTR4131 is a safe approach that did not modify cell function and engraftment capacities. In our experimental conditions, the use of a GAG mimetic did not, however, allow increasing cell expansion or optimizing their in vivo engraftment.
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Glucanos/farmacología , Trasplante de Células Madre Hematopoyéticas , Células Madre Hematopoyéticas/fisiología , Animales , Técnicas de Cultivo de Célula , Proliferación Celular , Células Cultivadas , Sangre Fetal/citología , Células Madre Hematopoyéticas/efectos de los fármacos , Humanos , Ratones Endogámicos NOD , Ratones SCID , Imitación MolecularRESUMEN
Statins are currently used for the treatment of hypercholesterolemia. Recently, we demonstrated that cerivastatin also reduces the proliferation and invasion of aggressive breast cancer cells, MDA-MB-231. In this report, a molecular mechanism to explain its anti-cancer action is proposed by combining the study of cerivastatin effect on both gene expression (microarray) and signal transduction pathways. Firstly, the expression of 13 genes was modified by cerivastatin and confirmed at protein level. They could contribute to the inhibition of both cell proliferation (down-regulation of cyclin D1, PCNA, c-myc and up-regulation p21(Waf1), p19(INK4d), integrin beta8) and cell invasion, either directly (decrease in u-PA, MMP-9, u-PAR, PAI-1 and increase in anti-oncogenes Wnt-5a and H-cadherin) or indirectly by stimulating an anti-angiogenic gene (thrombospondin-2). The anti-angiogenic activity was confirmed by in vivo experiments. Secondly, we demonstrated that the biochemical mechanism of its anti-cancer action could be mainly explained by the inhibition of RhoA-dependent cell signalling. This hypothesis was supported by the fact that a RhoA inhibitor (C3 exoenzyme) or a dominant negative mutant RhoA (N19RhoA) induced similar effects to those of cerivastatin. In conclusion, cerivastatin, by preventing RhoA prenylation, inhibits (i) the RhoA/ROCK pathway, leading to defective actin stress fibres formation responsible for the loss of traction forces required for cell motility and (ii) the RhoA/FAK/AKT signalling pathway that could explain the majority of cancer-related gene modifications described above. Thus, the inhibition of RhoA cell signalling could be a good strategy in therapy of aggressive forms of breast cancer.
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Antineoplásicos/farmacología , Neoplasias de la Mama/tratamiento farmacológico , Regulación Neoplásica de la Expresión Génica/efectos de los fármacos , Inhibidores de Hidroximetilglutaril-CoA Reductasas/farmacología , Piridinas/farmacología , ADP Ribosa Transferasas/farmacología , Animales , Toxinas Botulínicas/farmacología , Neoplasias de la Mama/genética , Neoplasias de la Mama/metabolismo , División Celular/efectos de los fármacos , Membrana Celular/metabolismo , Citosol/metabolismo , Humanos , Ratones , Ratones Desnudos , Invasividad Neoplásica , Neovascularización Patológica/tratamiento farmacológico , Análisis de Secuencia por Matrices de Oligonucleótidos , Prenilación de Proteína/efectos de los fármacos , Transducción de Señal/efectos de los fármacos , Células Tumorales Cultivadas/citología , Células Tumorales Cultivadas/efectos de los fármacos , Ensayos Antitumor por Modelo de Xenoinjerto , Proteína de Unión al GTP rhoA/metabolismoRESUMEN
OBJECTIVE: p21(WAF1/Cip/kip) and p27(Kip1) are cyclin-dependant kinase inhibitors controlling cell-cycle exit and differentiation of numerous cell types. Among hematopoietic cells, megakaryocytes express high levels of p21, while in erythroid cells, p27(Kip1) is predominant. As p21 and p27 could display overlapping functions and as megakaryocytes and erythroid cells derive from a bipotent progenitor, we developed an in vivo model to determine the specific role of p21 in controlling the proliferation/differentiation balance of erythroid and megakaryocytic progenitors. METHODS: Transgenic mice that overexpressed p21 under the control of the human GPIIb promoter in early progenitors and along megakaryocytic differentiation were generated. Different subsets of hematopoietic progenitors (BFU and CFU) and primitive cells (CAFC, LTC-IC) were analyzed by methylcellulose assay. Phenotypic evolution and clonogenic properties of the lin(-) population were analyzed along erythroid and megakaryocytic differentiation. RESULTS: We observed p21 ectopic expression in early hematopoietic progenitors (lin(-)Sca(+)), megakaryocytes, and, to a lesser extent, erythroid cells. This expression induced an important decrease in the number of CFU-MK, BFU-E, CFU-E, primitive progenitors (CAFC day 35), and LTC-IC, but did not affect the maturation process of these cells and the blood cell count. CONCLUSIONS: We show that variation of p21 expression level changes the fate of hematopoietic cells by favoring either proliferation or differentiation pathways. This effect of p21 is exerted not only at the level of primitive progenitors but also in more mature progenitors. However, in vivo, a systemic compensation mechanism is most likely activated in response to variations of the flow of progenitor production.
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Ciclinas/fisiología , Hematopoyesis/fisiología , Células Madre Hematopoyéticas/citología , Glicoproteína IIb de Membrana Plaquetaria/genética , Regiones Promotoras Genéticas , Animales , Recuento de Células Sanguíneas , Diferenciación Celular , División Celular , Linaje de la Célula , Ensayo de Unidades Formadoras de Colonias , Inhibidor p21 de las Quinasas Dependientes de la Ciclina , Ciclinas/biosíntesis , Ciclinas/genética , ADN Complementario/genética , Células Precursoras Eritroides/citología , Células Precursoras Eritroides/metabolismo , Regulación de la Expresión Génica , Genes Sintéticos , Hematopoyesis/genética , Células Madre Hematopoyéticas/metabolismo , Homeostasis , Humanos , Megacariocitos/citología , Megacariocitos/metabolismo , Ratones , Ratones Transgénicos , Proteínas Recombinantes de Fusión/fisiologíaRESUMEN
Primary myelofibrosis is a myeloproliferative neoplasm that is a precursor to myeloid leukemia. Dysmegakaryopoiesis and extramedullary hematopoiesis characterize primary myelofibrosis, which is also associated with bone marrow stromal alterations marked by fibrosis, neoangiogenesis, and osteomyelosclerosis. In particular, contributions to primary myelofibrosis from mesenchymal stromal cells (MSC) have been suggested by mouse studies, but evidence in humans remains lacking. In this study, we show that bone marrow MSCs from primary myelofibrosis patients exhibit unique molecular and functional abnormalities distinct from other myeloproliferative neoplasms and these abnormalities are maintained stably ex vivo in the absence of leukemic cells. Primary myelofibrosis-MSC overexpressed heparin-binding cytokines, including proinflammatory TGFß1 and osteogenic BMP-2, as well as glycosaminoglycans such as heparan sulfate and chondroitin sulfate. Transcriptome and functional analyses revealed alterations in MSC differentiation characterized by an increased osteogenic potential and a TGFß1 signaling signature. Accordingly, phospho-Smad2 levels were intrinsically increased in primary myelofibrosis-MSC along with enhanced expression of the master bone regulator RUNX2, while inhibition of the endogenous TGFß1 receptor TGFßR1 impaired osteogenic differentiation in these MSCs. Taken together, our results define the source of a critical osteogenic function in primary myelofibrosis that supports its pathophysiology, suggesting that combined targeting of both the hematopoietic and stromal cell compartments in primary myelofibrosis patients may heighten therapeutic efficacy.
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Diferenciación Celular/fisiología , Células Madre Mesenquimatosas/patología , Osificación Heterotópica/fisiopatología , Mielofibrosis Primaria/fisiopatología , Adulto , Anciano , Anciano de 80 o más Años , Animales , Células Cultivadas , Femenino , Xenoinjertos , Humanos , Masculino , Ratones , Ratones Desnudos , Persona de Mediana Edad , Reacción en Cadena de la PolimerasaRESUMEN
3-hydroxy-3-methylglutaryl coenzyme A reductase inhibitors (statins) reduce the risk of coronary event by cholesterollowering dependent and independent mechanisms. We have already described that the inhibitory effect of cerivastatin on angiogenesis contribute to the cholesterol-independent beneficial effect and was due to the inhibition of the cell signaling cascade RhoA/FAK/Akt. In this study, new insights in the molecular mechanism of action were provided. It indicates an inhibition of exposure of alpha V beta 3 integrin on cell membrane and a modification of gene expression. The inhibition of angiogenesis could be related to 1) an increase in genes involved in the inhibition of cell proliferation (p19(INK4), p21(Waf/Cip1),Wnt-5a), the inhibition of cell migration (Rho-GDI 1, alpha E-catenin) and 2) a downregulation of genes involved in angiogenesis (PAI-1, Vitronectin, HoxD3, Notch4) or in cell invasion (Semaphorin E). In addition, DNA repair protein genes (MLH1, XRCC1) were increased. This study may indicate new biological interest of genes involved in angiogenesis control.
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Inhibidores de la Angiogénesis/farmacología , Inhibidores de Hidroximetilglutaril-CoA Reductasas/farmacología , Neovascularización Patológica/tratamiento farmacológico , Piridinas/farmacología , Línea Celular , Endotelio Vascular/efectos de los fármacos , Endotelio Vascular/metabolismo , Expresión Génica/efectos de los fármacos , Humanos , Integrina alfaVbeta3/genética , Integrinas/genética , Neovascularización Patológica/genética , Neovascularización Patológica/fisiopatología , Receptores de Vitronectina/genética , Transducción de Señal/efectos de los fármacos , Proteína de Unión al GTP rhoA/antagonistas & inhibidoresRESUMEN
Human circulating endothelial progenitor cells isolated from peripheral blood generate in culture cells with features of endothelial cells named late-outgrowth endothelial colony-forming cells (ECFC). In adult blood, ECFC display a constant quantitative and qualitative decline during life span. Even after expansion, it is difficult to reach the cell dose required for cell therapy of vascular diseases, thus limiting the clinical use of these cells. Glycosaminoglycans (GAG) are components from the extracellular matrix (ECM) that are able to interact and potentiate heparin binding growth factor (HBGF) activities. According to these relevant biological properties of GAG, we designed a GAG mimetic having the capacity to increase the yield of ECFC production from blood and to improve functionality of their endothelial outgrowth. We demonstrate that the addition of [OTR(4131)] mimetic during the isolation process of ECFC from Cord Blood induces a 3 fold increase in the number of colonies. Moreover, addition of [OTR(4131)] to cell culture media improves adhesion, proliferation, migration and self-renewal of ECFC. We provide evidence showing that GAG mimetics may have great interest for cell therapy applied to vascular regeneration therapy and represent an alternative to exogenous growth factor treatments to optimize potential therapeutic properties of ECFC.
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Células Progenitoras Endoteliales/citología , Células Progenitoras Endoteliales/metabolismo , Glicosaminoglicanos/metabolismo , Adhesión Celular , Movimiento Celular , Proliferación Celular , Ensayo de Unidades Formadoras de Colonias , Femenino , Sangre Fetal/citología , Glicosaminoglicanos/química , Humanos , Recién Nacido , MasculinoRESUMEN
Pleiotrophin (PTN) is a growth factor present in the extracellular matrix of the growth plate during bone development and in the callus during bone healing. Bone healing is a complicated process that recapitulates endochondral bone development and involves many cell types. Among those cells, mesenchymal stromal cells (MSC) are able to differentiate toward chondrogenic and osteoblastic lineages. We aimed to determine PTN effects on differentiation properties of human bone marrow stromal cells (hBMSC) under chondrogenic induction using histological analysis and quantitative reverse transcription polymerase chain reaction. PTN dramatically potentiated chondrogenic differentiation as indicated by a strong increase of collagen 2 protein, and cartilage-related gene expression. Moreover, PTN increased transcription of hypertrophic chondrocyte markers such as MMP13, collagen 10 and alkaline phosphatase and enhanced calcification and the content of collagen 10 protein. These effects are dependent on PTN receptors signaling and PI3 K pathway activation. These data suggest a new role of PTN in bone regeneration as an inducer of hypertrophy during chondrogenic differentiation of hBMSC.
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Células de la Médula Ósea/metabolismo , Proteínas Portadoras/metabolismo , Diferenciación Celular/fisiología , Aumento de la Célula , Condrogénesis/fisiología , Citocinas/metabolismo , Células Madre Mesenquimatosas/metabolismo , Células de la Médula Ósea/citología , Humanos , Células Madre Mesenquimatosas/citologíaRESUMEN
The electrospinning technique combined with the electrospraying process provides a straightforward and versatile approach for the fabrication of novel nanofibrous biocomposite scaffolds with structural, mechanical, and biological properties potentially suitable for bone tissue regeneration. In this comparative investigation, three types of poly(3-hydroxybutyrate) (PHB)-based scaffolds were engineered: (i) PHB mats by electrospinning of a PHB solution, (ii) mats of PHB/hydroxyapatite nanoparticle (nHA) blends by electrospinning of a mixed solution containing PHB and nHAs, and (iii) mats constituted of PHB nanofibers and nHAs by simultaneous electrospinning of a PHB solution and electrospraying of a nHA dispersion. Scaffolds based on PHB/nHA blends displayed improved mechanical properties compared to those of neat PHB mats, due to the incorporation of nHAs within the fibers. The electrospinning/electrospraying approach afforded biocomposite scaffolds with lower mechanical properties, due to their higher porosity, but they displayed slightly better biological properties. In the latter case, the bioceramic, i.e. nHAs, largely covered the fiber surface, thus allowing for a direct exposure to cells. The 21 day-monitoring through the use of MTS assays and SEM analyses demonstrated that human mesenchymal stromal cells (hMSCs) remained viable on PHB/nHA biocomposite scaffolds and proliferated continuously until reaching confluence.
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Materiales Biocompatibles/farmacología , Huesos/efectos de los fármacos , Durapatita/farmacología , Hidroxibutiratos/farmacología , Nanofibras/química , Poliésteres/farmacología , Ingeniería de Tejidos/métodos , Andamios del Tejido/química , Rastreo Diferencial de Calorimetría , Humanos , Células Madre Mesenquimatosas/citología , Células Madre Mesenquimatosas/efectos de los fármacos , Células Madre Mesenquimatosas/ultraestructura , Nanofibras/ultraestructura , Nanopartículas/química , Nanopartículas/ultraestructura , Porosidad , Prohibitinas , Estrés Mecánico , Resistencia a la Tracción/efectos de los fármacos , TermogravimetríaRESUMEN
Widespread skeletal muscle degeneration and impaired regeneration lead to progressive muscle weakness and premature death in patients with Duchenne muscular dystrophy (DMD). Dystrophic muscles are progressively replaced by nonfunctional tissue because of exhaustion of muscle precursor cells and excessive accumulation of extracellular matrix (ECM). Sulfated glycosaminoglycans (GAGs) are components of the ECM and are increasingly implicated in the regulation of biologic processes, but their possible role in the progression of DMD pathology is not understood. In the present study, we performed immunohistochemical and biochemical analyses of endogenous GAGs in skeletal muscle biopsies of 10 DMD patients and 11 healthy individuals (controls). Immunostaining targeted to specific GAG species showed greater deposition of chondroitin sulfate (CS)/dermatan (DS) sulfate in DMD patient biopsies versus control biopsies. The selective accumulation of CS/DS in DMD biopsies was confirmed by biochemical quantification assay. In addition, high-performance liquid chromatography analysis demonstrated a modification of the sulfation pattern of CS/DS disaccharide units in DMD muscles. In conclusion, our data open up a new path of investigation and suggest that GAGs could represent a new and original therapeutic target for improving the success of gene or cell therapy for the treatment of muscular dystrophies.
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Sulfatos de Condroitina/metabolismo , Dermatán Sulfato/análogos & derivados , Glicosaminoglicanos/metabolismo , Músculo Esquelético/metabolismo , Músculo Esquelético/patología , Distrofia Muscular de Duchenne/patología , Adolescente , Adulto , Niño , Sulfatos de Condroitina/genética , Cromatografía Líquida de Alta Presión , Dermatán Sulfato/genética , Dermatán Sulfato/metabolismo , Progresión de la Enfermedad , Femenino , Glicosaminoglicanos/genética , Humanos , Masculino , ARN Mensajero/genética , Adulto JovenRESUMEN
A straightforward and versatile method for immobilizing polysaccharides on the surface of poly(3-hydroxybutyrate-co-3-hydroxyvalerate) (PHBHV) electrospun fibers is developed with the objective of designing a new functional biomaterial having a significant effect on cell proliferation. The approach relies on a one-step procedure: UV grafting of a photosensitive dextran (AQ-Dext) on the surface of PHBHV fibers according to a "grafting onto" method, with the use of an anthraquinone derivative. The photografting is conducted through a photoinduced free radical process employing an anthraquinone-based photosensitizer in aqueous medium. Under appropriate conditions, AQ-Dext reacts with C-H σ-bonds of the polymer substrate (PHBHV) to produce a semianthraquinone radical according to an H-abstraction reaction. This radical recombines together with the alkylradical (RË) formed at the surface of PHBHV fibers via the oxygen atom of the anthraquinone photolinker. The photochemical mechanism of the AQ-Dext photolysis is entirely described for the first time by an electron spin resonance technique and laser flash photolysis. The modified PHBHV microfibrous scaffolds are extensively characterized by water contact angle measurements, XPS analysis and atomic force microscopy, confirming the covalent grafting of dextran on PHBHV fibers. Finally, a primary investigation demonstrates that dextran modified PHBHV fibers are permissive for optimized cell colonization and proliferation. The cell morphologies are described by SEM micrographs, revealing a significant affinity and favorable interactions for adherence of human mesenchymal stem cells (hMSCs) on scaffolds provided by dextran chemical structure. Moreover, the proliferation rate of hMSCs increases on this new functionalized biomaterial associated with a higher extra-cellular matrix production after 5 days of culture in comparison with native PHBHV fibers.
RESUMEN
Tissue engineering approaches to stimulate bone formation currently combine bioactive scaffolds with osteocompetent human mesenchymal stem cells (hMSC). Moreover, osteogenic and angiogenic factors are required to promote differentiation and survival of hMSC through improved vascularization through the damaged extracellular matrix (ECM). Glycosaminoglycans (GAGs) are ECM compounds acting as modulators of heparin-binding protein activities during bone development and regenerative processes. GAG mimetics have been proposed as ECM stabilizers and were previously described for their positive effects on bone formation and angiogenesis after local treatment. Here, we developed a strategy associating the GAG mimetic [OTR4120] with bone substitutes to optimize stem cell-based therapeutic products. We showed that [OTR4120] was able to potentiate proliferation, migration, and osteogenic differentiation of hMSC in vitro. Its link to tricalcium phosphate/hydroxyapatite scaffolds improved their colonization by hMSC. Surprisingly, when these combinations were tested in an ectopic model of bone formation in immunodeficient mice, the GAG mimetics inhibit bone formation induced by hMSC and promoted an osteoclastic activity. Moreover, the inflammatory response was modulated, and the peri-implant vascularization stimulated. All together, these findings further support the ability of GAG mimetics to organize the local ECM to coordinate the host response toward the implanted biomaterial, and to inhibit the abnormal bone formation process on a subcutaneous ectopic site.