Immunomodulatory effects of bone marrow versus adipose tissue-derived mesenchymal stromal cells on NK cells: implications in the transplantation setting

INTRODUCTION

The ability of mesenchymal stromal cells (MSC) to suppress T-cell function has prompted their therapeutic use for graft-versus-host disease (GVHD) control. However, as MSC also modulate the activity of NK cells, which play an important role in graft-versus-leukemia (GVL) reaction, their administration could hamper this beneficial effect of allogeneic hematopoietic stem cell transplantation. MSC can be expanded from several sources, especially bone marrow and fat, but it is not well established if the cell source makes a difference in their immunoregulatory capacity.

OBJECTIVE

The aim of this study was to compare the immunomodulatory effect of MSC derived from bone marrow (BM-CSM) or adipose tissue (AT-MSC) on NK cells, to determine whether the use of MSC from one or the other origin could be more favorable to preserve NK cell activity and, therefore, GVL.

METHODS

Human NK cells were stimulated with IL-15 in the presence of BM-MSC or AT-MSC. The effect of both MSC populations on NK cell proliferation, cell cycle progression, and CD56 expression was analyzed by flow cytometry. Cytokine secretion was measured by ELISA, and cytotoxic activity was assessed by calcein release assays.

RESULTS

Although both BM-MSC and AT-MSC induced a similar inhibition of NK cell proliferation, only BM-MSC decreased significantly NK cell cytotoxic activity and showed a trend for a higher reduction of IFN-γ secretion.

CONCLUSION

These results suggest that, in the context of GVHD inhibition, the use of AT-MSC rather than BM-MSC could further preserve NK cell activity and, thus, favor GVL.

Ex vivo identification and characterization of a population of CD13(high) CD105(+) CD45(-) mesenchymal stem cells in human bone marrow

Introduction

Mesenchymal stem cells (MSCs) are multipotent cells capable of self-renewal and multilineage differentiation. Their multipotential capacity and immunomodulatory properties have led to an increasing interest in their biological properties and therapeutic applications. Currently, the definition of MSCs relies on a combination of phenotypic, morphological and functional characteristics which are typically evaluated upon in vitro expansion, a process that may ultimately lead to modulation of the immunophenotypic, functional and/or genetic features of these cells. Therefore, at present there is great interest in providing markers and phenotypes for direct in vivo and ex vivo identification and isolation of MSCs.

Methods

Multiparameter flow cytometry immunophenotypic studies were performed on 65 bone marrow (BM) samples for characterization of CD13^high CD105⁺ CD45^– cells. Isolation and expansion of these cells was performed in a subset of samples in parallel to the expansion of MSCs from mononuclear cells following currently established procedures. The protein expression profile of these cells was further assessed on (paired) primary and in vitro expanded BM MSCs, and their adipogenic, chondrogenic and osteogenic differentiation potential was also determined.

Results

Our results show that the CD13^high CD105⁺ CD45⁻ immunophenotype defines a minor subset of cells that are systematically present ex vivo in normal/reactive BM (n = 65) and that display immunophenotypic features, plastic adherence ability, and osteogenic, adipogenic and chondrogenic differentiation capacities fully compatible with those of MSCs. In addition, we also show that in vitro expansion of these cells modulates their immunophenotypic characteristics, including changes in the expression of markers currently used for the definition of MSCs, such as CD105, CD146 and HLA-DR.

Conclusions

BM MSCs can be identified ex vivo in normal/reactive BM, based on a robust CD13^high CD105⁺ and CD45⁻ immunophenotypic profile. Furthermore, in vitro expansion of these cells is associated with significant changes in the immunophenotypic profile of MSCs.

Electronic supplementary material

The online version of this article (doi:10.1186/s13287-015-0152-8) contains supplementary material, which is available to authorized users.

Transcriptomic profile induced in bone marrow mesenchymal stromal cells after interaction with multiple myeloma cells: implications in myeloma progression and myeloma bone disease

Despite evidence about the implication of the bone marrow (BM) stromal microenvironment in multiple myeloma (MM) cell growth and survival, little is known about the effects of myelomatous cells on BM stromal cells. Mesenchymal stromal cells (MSCs) from healthy donors (dMSCs) or myeloma patients (pMSCs) were co-cultured with the myeloma cell line MM.1S, and the transcriptomic profile of MSCs induced by this interaction was analyzed. Deregulated genes after co-culture common to both d/pMSCs revealed functional involvement in tumor microenvironment cross-talk, myeloma growth induction and drug resistance, angiogenesis and signals for osteoclast activation and osteoblast inhibition. Additional genes induced by co-culture were exclusively deregulated in pMSCs and predominantly associated to RNA processing, the ubiquitine-proteasome pathway, cell cycle regulation, cellular stress and non-canonical Wnt signaling. The upregulated expression of five genes after co-culture (CXCL1, CXCL5 and CXCL6 in d/pMSCs, and Neuregulin 3 and Norrie disease protein exclusively in pMSCs) was confirmed, and functional in vitro assays revealed putative roles in MM pathophysiology. The transcriptomic profile of pMSCs co-cultured with myeloma cells may better reflect that of MSCs in the BM of myeloma patients, and provides new molecular insights to the contribution of these cells to MM pathophysiology and to myeloma bone disease.

Preclinical activity of the oral proteasome inhibitor MLN9708 in Myeloma bone disease

PURPOSE

MLN9708 (ixazomib citrate), which hydrolyzes to pharmacologically active MLN2238 (ixazomib), is a next-generation proteasome inhibitor with demonstrated preclinical and clinical antimyeloma activity, but yet with an unknown effect on myeloma bone disease. Here, we investigated its bone anabolic and antiresorptive effects in the myeloma setting and in comparison with bortezomib in preclinical models.

EXPERIMENTAL DESIGN

The in vitro effect of MLN2238 was tested on osteoclasts and osteoclast precursors from healthy donors and patients with myeloma, and on osteoprogenitors derived from bone marrow mesenchymal stem cells also from both origins. We used an in vivo model of bone marrow-disseminated human myeloma to evaluate MLN2238 antimyeloma and bone activities.

RESULTS

Clinically achievable concentrations of MLN2238 markedly inhibited in vitro osteoclastogenesis and osteoclast resorption; these effects involved blockade of RANKL (receptor activator of NF-κB ligand)-induced NF-κB activation, F-actin ring disruption, and diminished expression of αVβ3 integrin. A similar range of MLN2238 concentrations promoted in vitro osteoblastogenesis and osteoblast activity (even in osteoprogenitors from patients with myeloma), partly mediated by activation of TCF/β-catenin signaling and upregulation of the IRE1 component of the unfolded protein response. In a mouse model of bone marrow-disseminated human multiple myeloma, orally administered MLN2238 was equally effective as bortezomib to control tumor burden and also provided a marked benefit in associated bone disease (sustained by both bone anabolic and anticatabolic activities).

CONCLUSION

Given favorable data on pharmacologic properties and emerging clinical safety profile of MLN9708, it is conceivable that this proteasome inhibitor may achieve bone beneficial effects in addition to its antimyeloma activity in patients with myeloma.

Secular changes in Paget's disease: contrasting changes in the number of new referrals and in disease severity in two neighboring regions of Spain

SUMMARY

We studied the changes in the number of new referrals with Paget's disease of bone (PDB) and severity of PDB in a high prevalence focus and its neighboring region. Referral of patients changed only in the high prevalence focus. The severity of PDB decreased in both regions. These results could suggest the effects of an environmental influence on disease activity.

INTRODUCTION

The prevalence and severity of PDB have decreased in several countries over recent years. We previously reported a high radiological prevalence of PDB in Vitigudino. Here we sought to determine if secular changes in the number of new referrals and severity of PDB had occurred over recent years.

METHODS

We studied 280 patients with clinically diagnosed PDB who were evaluated at a regional referral center for metabolic bone disease between 1986 and 2009. Changes in the number of new referrals were calculated by relating these data to the number of subjects at risk as determined by population registers. Trends in disease severity were analyzed with alkaline phosphatase (ALP) activity and disease extent on scan.

RESULTS

Referrals from the Vitigudino region increased substantially between 1986 and 2003 but fell markedly between 2004 and 2009, although by this time there had been depopulation of the region due to emigration. No significant changes in the rates of referral occurred in the remainder of Salamanca. ALP activity and disease extent decreased in Salamanca, but only ALP activity decreased in Vitigudino. Referrals rate and severity of PDB in Vitigudino were greater than in the remainder of Salamanca.

CONCLUSIONS

Referral of patients with clinically diagnosed PDB has remained stable for most of Salamanca during the past 24 years, but substantial changes have been observed in Vitigudino. In agreement with other reports, the severity of PDB has decreased in both regions consistent with the effects of an environmental influence on disease activity.

The streams of Gorgona Natural National Park within the global context: an introduction to the special issue

Este artículo destaca la importancia de las islas para proponer y probar hipótesis en ecología de arroyos y, por lo tanto, aboga por la implementación de estudios de referencia en la isla Gorgona (Pacífico colombiano). En primer lugar, resume estudios ecológicos pasados ​​en arroyos en la isla Gorgona y describe una serie de artículos resultantes de una encuesta reciente. Estos documentos informan que la isla Gorgona exhibe un clima marítimo, una cubierta de selva tropical y una litología basáltica e intrusiva, todas características típicas de islas en otros lugares. También describen que a pesar del efecto insular sobre la biota de los arroyos, la proximidad (<50 km) de la isla a la costa del Pacífico de Colombia facilitó la dispersión de muchos componentes faunísticos y florísticos del continente, brindando así una oportunidad única para estudiar los arroyos costeros. en el Chocó Biogeográfico. Por último, el estado de la isla Gorgona como parque natural establecido en 1984, y una historia relativamente bien conocida de usos de la tierra, pueden contribuir aún más a apoyar programas de investigación con objetivos a largo plazo y gran escala

Características físico-químicas de las quebradas del Parque Nacional Natural Gorgona, Pacífico colombiano

En Colombia son escasos los estudios biogeoquímicos en quebradas naturales. Por esa razón se midieron varios parámetros físico-químicos y las concentraciones de carbono orgánico disuelto, nitrógeno total, fósforo total, cloruros y sulfatos para aproximarnos al papel de procesos geológicos, atmosféricos y biológicos en las quebradas de la Isla Gorgona en periodos de baja y alta precipitación durante 2008. Las aguas superficiales son prístinas por los bajos contenidos de nitrógeno. La litología volcánica, predominantemente basáltica e instrusiva ultramáfica, posiblemente determina la ocurrencia de aguas salinas (conductividad > 500 μMhos/cm), neutro-alcalinas (pH < 8,5) y ricas en fósforo total (< 200 μg/l). Los aerosoles marinos son los posibles responsables de una alta concentración de cloruros (> 2 mg/l). La concentración de carbono orgánico disuelto fue mayor en bosques maduros (> 60 mg/l) que en secundarios y rastrojos (< 60 mg/l). La baja concentración de sulfatos sugiere que no hay aportes atmosféricos desde fuentes industriales o volcánicas, aunque existen emisiones submarinas de gases en La Azufrada. El disturbio hidrológico alteró la concentración de los elementos dependiendo de su naturaleza y de las características de las cuencas.

GA, Lizarazo-M. PX, Blanco JF. Patrones espacio-temporales de la estructura y composición de la hojarasca en las quebradas del Parque Nacional Natural Gorgona

Este trabajo estima la estructura y composición de la tafocenosis de la hojarasca acumulada en el lecho de nueve quebradas de la isla Gorgona en abril y junio de 2008. La pácora (Cespedesia macrophylla) fue la especie dominante en términos de biomasa total en toda la isla, aunque fue más abundante en las quebradas cuyos bosques ribereños fueron deforestados antes de la declaración del parque nacional o están sometidos a disturbios naturales (e.g., caída de árboles y los derrumbes) que frecuentemente abren el dosel. Sin embargo, se registraron más de cien morfoespecies, veintidós de las cuales se registraron en ambos muestreos. La mayor parte de las especies aporta poca biomasa y número de hojas, y por lo tanto no parecen ser funcionalmente importantes. Además de las especies dominantes, la biomasa total, abundancia total (número de hojas) y riqueza de la tafocenosis difiere significativamente entre las quebradas posiblemente como consecuencia del estado sucesional del bosque ribereño. Durante la época de lluvias se redujo significativamente la biomasa de la hojarasca acumulada.

[Effects mangrove conversion to pasture on density and shell size of two gastropods in the Turbo River Delta (Urabá Gulf, Caribbean coast of Colombia)]

Mangrove deforestation is widespread in the Greater Caribbean but its impact on macrobenthos has not been evaluated to date. In order to assess the impact of mangrove conversion to pasture, densities and shell sizes of two dominant gastropods (Neritina virginea and Melampus coffeus) were compared among four mangrove types: 1) Rhizophora mangle-dominated fringing mangroves, 2) Avicennia germinans-dominated basin mangroves, 3) Mixed-species basin mangroves, and 4) A. germinans- basin mangroves converted to pastures, in the Turbo River Delta (Urabá Gulf, Colombia). Mangrove types were polygon-delimited with satellite images and color aerial photographs were taken in 2009. Various (n<5) polygons per mangrove type were sampled in January, July and December 2009, and a total (n<20) 0.025m2-quadrats were randomly placed along each polygon. Forest structure variables, pore-water physicochemical variables and sediment-grain metrics were measured in the four mangrove types. Mean density and size of both gastropod species were measured. The results showed that the mean density and size of both species were significantly greater in R. mangle-fringing mangroves. N. virginea density decreased gradually towards the A. germinans-basin mangroves seemly related to the diadromous life-history. This species nearly disappeared in the neighboring pastures because individuals were constrained to a few remaining flooded areas. In the pastures, M. coffeus individuals were clumped in the remaining A. germinans trees due to its climbing behavior as a pulmonate. We hypothesize that the decline of these two gastropods was related to physical microhabitat (e.g. trees, prop roots, and seedlings) degradation, and alteration of soil properties (e.g. temperature, pH, organic matter content). Finally, we also hypothesize that the local extinction of N. virginea due to clear-cutting may exert strong negative effects on the ecosystem function because it is a dominant omnivore.

Cambios multianuales y espaciales de la composición y estructura del ensamblaje de insectos acuáticos en las quebradas perennes de la Isla Gorgona, Colombia

Este estudio presenta un análisis del cambio multi-anual de los años 1986, 1993 y 2008, de la composición y estructura del ensamble de insectos acuáticos en cinco quebradas en las vertientes Este (Ilú, Iguapoga y Pizarro) y Oeste (Cocal Norte y La Camaronera o Cocal Sur) de Isla Gorgona, Colombia. Se compararon datos de estudios previos desarrollados por Calá en 1986 y Zamora et al. en 1993 y los obtenidos por el proyecto GIS-BIO en 2008. Se realizaron comparaciones en tres escalas espaciales: isla (diversidad γ), vertientes (β) y quebradas (α). El número de órdenes en 1986, 1993 y 2008 fue 8, 7 y 9, respectivamente. Entre 1993 y 2008 aumentaron el número de familias (de 17 a 27) y el de géneros (de 24 a 51). Debido al incremento en el número de taxones, la similitud (Sorensen) entre 1993 y 2008, fue 57,8% en términos de la composición de familias y 32,0% en relación de géneros. El índice de diversidad de Shannon-Wiener (H’) aumentó en el tiempo, en 1993 el promedio para la isla fue 1,92 (1,67-2,12 nats/ind.) y en 2008 fue 2,54 (2,30-2,82 nats/ind.). La dominancia (D) (< 0,19) y la equidad (J’) (> 0,68) en promedio fueron similares en ambos períodos. Al comparar las vertientes, la Este presentó mayor número de familias y géneros en ambos períodos. La similitud de la composición faunística entre ellas fue mayor para el año 2008 (74%) que 1993 (50%); por tanto, el recambio de géneros (diversidad β) entre vertientes fue inverso. La relación entre la diversidad local y regional fue de tipo I (insaturada) que para 1993 y 2008. Los patrones temporales y espaciales podrían ser explicados por la deforestación que sufrió el área “El Poblado” durante el funcionamiento de la penitenciaria entre 1960 y 1984. El bosque nativo a lo largo de varias quebradas fue reemplazado por cultivos de “pan-coger”, o sometido a entresaca de madera. Adicionalmente, se construyó una microcentral eléctrica en una de las quebradas. Desde la declaración de Isla Gorgona como Parque Nacional Natural en 1984, las cuencas impactadas entraron en un proceso de recuperación natural. Los muestreos en 1993 y 2008 representaron trayectorias de sucesión de 10 y 24 años, respectivamente. Sin embargo, no se descarta en los resultados, un efecto por las diferencias en el esfuerzo de muestreo entre años y la no disponibilidad para Suramérica de claves taxonómicas para la identificación de los organismos en los años 90s. Ésto se apoya en una mayor tasa de registros nuevos de familias y géneros en la vertiente Oeste, cuyo paisaje ha presentado mínima intervención humana.

The hydroclimatology of Gorgona Island: seasonal and ENSO-related Patternsa

Most small watersheds in the Tropical Eastern Pacific remain ungauged, and discharge analyses using gauge and simulated data have been published only for a few large rivers. I analyzed a 20-yr record of rainfall and stream discharge from Gorgona Island, a natural national park located 30 km offshore in the Pacific Ocean of Colombia to explore intra- and inter-annual patterns and drivers. Gorgona Island receives > 6.600 mm of annual rainfall thus feeding numerous permanent streams. Inter Tropical Convergence Zone-driven seasonal rainfall patterns (unimodal) were consistent regardless of interannual variability. However, a large yearly variation was observed between May and August. Monthly and annual rainfall in Gorgona Island was greater than at a neighboring continental-coastal area, suggesting the occurrence of orographic and convective rain. El Niño Southern Oscillation slightly influenced interannual variation in rainfall, but it strongly influenced stream discharge. The importance of the Chocó Jet Current and Meso-Scale Stationary Systems is discussed

Macroinvertebrate assemblages in Gorgona Island streams: spatial patterns during two contrasting hydrologic periods

Studies comparing various streams are scarce in tropical insular systems and inexistent in Colombia. In order to understand the spatial patterns of macroinvertebrates in tropical insular streams, and the environmental drivers of such patterns, we tested for patterns among streams but using a nested sampling design from streams to microhabitats in Gorgona Island (Colombia, Tropical Eastern Pacific) during two seasons (low and high precipitation). We found that benthic macroinvertebrate assemblages showed clear differences among streams despite of the variability within nested levels. Hydrologic disturbance tended to homogenize spatial patterns in most of the streams. Although ordinations of sampling units using either macroinvertebrate composition or environmental variables were not fully consistent, it was evident that water physicochemistry influenced by underlying geology was a pervasive driver of macroinvertebrate distribution. We highlight the importance of incorporating multiscale sampling designs for studying distributions of macroinvertebrates in tropical islands, and for biomonitoring.

Sobre los filtros que determinan la distribución y la abundancia de los macroinvertebrados diádromos y no-díadromos en cada nivel jerarárquico del paisaje fluvial en islas

Los ecosistemas fluviales presentes en las islas son importantes ya que albergan especies con historias de vida particulares. Algunas de ellas son organismos diádromos como peces, camarones, cangrejos y caracoles que constantemente migran entre las cabeceras de los ríos y los estuarios o el océano para completar sus ciclos de vida. Otros, como los insectos, constituyen la fauna no-diádroma, la cual debido a su limitada capacidad de dispersión, a las altas tasas de especiación y al aislamiento propio de cada isla, podría encontrarse restringida a una región insular. Esta clara diferencia en las estrategias de vida, hace necesario el relevamiento de información acerca de los patrones de abundancia y distribución y de los procesos responsables en todos los niveles de la jerarquía espacial (regiones, microcuencas, segmentos, tramos, hábitats y microhábitats), con el fin de establecer medidas que garanticen un manejo adecuado tendiente a la conservación de estos ecosistemas. Por ello, este trabajo presenta una revisión sobre los principales factores que determinan la estructura de los ensambles diádromos y no-diádromos, y que operan en cada nivel jerárquico de las quebradas insulares. 

Analysis of the immune system of multiple myeloma patients achieving long-term disease control by multidimensional flow cytometry

Multiple myeloma remains largely incurable. However, a few patients experience more than 10 years of relapse-free survival and can be considered as operationally cured. Interestingly, long-term disease control in multiple myeloma is not restricted to patients with a complete response, since some patients revert to having a profile of monoclonal gammopathy of undetermined significance. We compared the distribution of multiple compartments of lymphocytes and dendritic cells in the bone marrow and peripheral blood of multiple myeloma patients with long-term disease control (n=28), patients with newly diagnosed monoclonal gammopathy of undetermined significance (n=23), patients with symptomatic multiple myeloma (n=23), and age-matched healthy adults (n=10). Similarly to the patients with monoclonal gammopathy of undetermined significance and symptomatic multiple myeloma, patients with long-term disease control showed an expansion of cytotoxic CD8(+) T cells and natural killer cells. However, the numbers of bone marrow T-regulatory cells were lower in patients with long-term disease control than in those with symptomatic multiple myeloma. It is noteworthy that B cells were depleted in patients with monoclonal gammopathy of undetermined significance and in those with symptomatic multiple myeloma, but recovered in both the bone marrow and peripheral blood of patients with long-term disease control, due to an increase in normal bone marrow B-cell precursors and plasma cells, as well as pre-germinal center peripheral blood B cells. The number of bone marrow dendritic cells and tissue macrophages differed significantly between patients with long-term disease control and those with symptomatic multiple myeloma, with a trend to cell count recovering in the former group of patients towards levels similar to those found in healthy adults. In summary, our results indicate that multiple myeloma patients with long-term disease control have a constellation of unique immune changes favoring both immune cytotoxicity and recovery of B-cell production and homing, suggesting improved immune surveillance.

The epoxyketone-based proteasome inhibitors carfilzomib and orally bioavailable oprozomib have anti-resorptive and bone-anabolic activity in addition to anti-myeloma effects

Proteasome inhibitors (PIs), namely bortezomib, have become a cornerstone therapy for multiple myeloma (MM), potently reducing tumor burden and inhibiting pathologic bone destruction. In clinical trials, carfilzomib, a next generation epoxyketone-based irreversible PI, has exhibited potent anti-myeloma efficacy and decreased side effects compared with bortezomib. Carfilzomib and its orally bioavailable analog oprozomib, effectively decreased MM cell viability following continual or transient treatment mimicking in vivo pharmacokinetics. Interactions between myeloma cells and the bone marrow (BM) microenvironment augment the number and activity of bone-resorbing osteoclasts (OCs) while inhibiting bone-forming osteoblasts (OBs), resulting in increased tumor growth and osteolytic lesions. At clinically relevant concentrations, carfilzomib and oprozomib directly inhibited OC formation and bone resorption in vitro, while enhancing osteogenic differentiation and matrix mineralization. Accordingly, carfilzomib and oprozomib increased trabecular bone volume, decreased bone resorption and enhanced bone formation in non-tumor bearing mice. Finally, in mouse models of disseminated MM, the epoxyketone-based PIs decreased murine 5TGM1 and human RPMI-8226 tumor burden and prevented bone loss. These data demonstrate that, in addition to anti-myeloma properties, carfilzomib and oprozomib effectively shift the bone microenvironment from a catabolic to an anabolic state and, similar to bortezomib, may decrease skeletal complications of MM.

Dasatinib as a bone-modifying agent: anabolic and anti-resorptive effects

BACKGROUND

Bone loss, in malignant or non-malignant diseases, is caused by increased osteoclast resorption and/or reduced osteoblast bone formation, and is commonly associated with skeletal complications. Thus, there is a need to identify new agents capable of influencing bone remodeling. We aimed to further pre-clinically evaluate the effects of dasatinib (BMS-354825), a multitargeted tyrosine kinase inhibitor, on osteoblast and osteoclast differentiation and function.

METHODS

For studies on osteoblasts, primary human bone marrow mensenchymal stem cells (hMSCs) together with the hMSC-TERT and the MG-63 cell lines were employed. Osteoclasts were generated from peripheral blood mononuclear cells (PBMC) of healthy volunteers. Skeletally-immature CD1 mice were used in the in vivo model.

RESULTS

Dasatinib inhibited the platelet derived growth factor receptor-β (PDGFR-β), c-Src and c-Kit phosphorylation in hMSC-TERT and MG-63 cell lines, which was associated with decreased cell proliferation and activation of canonical Wnt signaling. Treatment of MSCs from healthy donors, but also from multiple myeloma patients with low doses of dasatinib (2-5 nM), promoted its osteogenic differentiation and matrix mineralization. The bone anabolic effect of dasatinib was also observed in vivo by targeting endogenous osteoprogenitors, as assessed by elevated serum levels of bone formation markers, and increased trabecular microarchitecture and number of osteoblast-like cells. By in vitro exposure of hemopoietic progenitors to a similar range of dasatinib concentrations (1-2 nM), novel biological sequelae relative to inhibition of osteoclast formation and resorptive function were identified, including F-actin ring disruption, reduced levels of c-Fos and of nuclear factor of activated T cells 1 (NFATc1) in the nucleus, together with lowered cathepsin K, αVβ3 integrin and CCR1 expression.

CONCLUSIONS

Low dasatinib concentrations show convergent bone anabolic and reduced bone resorption effects, which suggests its potential use for the treatment of bone diseases such as osteoporosis, osteolytic bone metastasis and myeloma bone disease.

[Long-term analysis of minimally invasive surgery in knee arthroplasty]

BACKGROUND

Knee arthroplasty is the treatment of choice for gonarthrosis. The development of minimally invasive surgery (MIS) requires assessing results based on the classical approaches and this is the purpose of our study.

METHODS

Randomized, prospective study comparing two groups; one underwent MIS (45 patients) and the second one a classical approach (51 patients); both groups were comparable. The following variables were assessed in the immediate postoperative period and at 4 and 8 years: blood loss, pain according to the VAS, flexion and extension and quality of life measured with the SF-36.

RESULTS

In the immediate postoperative period we observed statistically significant differences (p < 0.05) in favor of the MIS approach in pain, hospital stay and blood loss. However, this was not observed at 4 and 8 years concerning pain, quality of life and range of motion. We observed an improvement in the functional scale and quality of life compared with the preoperative status, without any differences when both groups were compared.

CONCLUSIONS

The MIS technique results in a better immediate postoperative period, but no differences were seen in the choice of the approach 4 and 8 years after surgery.

Bone marrow mesenchymal stem cells for improving hematopoietic function: an in vitro and in vivo model. Part 2: Effect on bone marrow microenvironment

The aim of the present study was to determine how mesenchymal stem cells (MSC) could improve bone marrow (BM) stroma function after damage, both in vitro and in vivo. Human MSC from 20 healthy donors were isolated and expanded. Mobilized selected CD34⁺ progenitor cells were obtained from 20 HSCT donors. For in vitro study, long-term bone marrow cultures (LTBMC) were performed using a etoposide damaged stromal model to test MSC effect in stromal confluence, capability of MSC to lodge in stromal layer as well as some molecules (SDF1, osteopontin,) involved in hematopoietic niche maintenance were analyzed. For the in vivo model, 64 NOD/SCID recipients were transplanted with CD34+ cells administered either by intravenous (IV) or intrabone (IB) route, with or without BM derived MSC. MSC lodgement within the BM niche was assessed by FISH analysis and the expression of SDF1 and osteopontin by immunohistochemistry. In vivo study showed that when the stromal damage was severe, TP-MSC could lodge in the etoposide-treated BM stroma, as shown by FISH analysis. Osteopontin and SDF1 were differently expressed in damaged stroma and their expression restored after TP-MSC addition. Human in vivo MSC lodgement was observed within BM niche by FISH, but MSC only were detected and not in the contralateral femurs. Human MSC were located around blood vessels in the subendoestal region of femurs and expressed SDF1 and osteopontin. In summary, our data show that MSC can restore BM stromal function and also engraft when a higher stromal damage was done. Interestingly, MSC were detected locally where they were administered but not in the contralateral femur.

Titanium and tantalum as mesenchymal stem cell scaffolds for spinal fusion: an in vitro comparative study

INTRODUCTION

In the last few years, great interest has been focused on tissue engineering as a potential therapeutic approach for musculoskeletal diseases. The role of metallic implants for spinal fusion has been tested in preclinical and clinical settings. Titanium and tantalum have excellent biocompatibility and mechanical properties and are being used in this situation. On the other hand, the therapeutic role of mesenchymal stem cells (MSC) is extensively explored for their multilineage differentiation into osteoblasts.

OBJECTIVES

In vitro comparison of titanium and tantalum as MSCs scaffolds.

MATERIAL AND METHODS

In the present study, we have compared the in vitro expansion capacity, viability, immunophenotype (both explored by flow cytometry) and multi-differentiation ability of MSC cultured in the presence of either titanium or tantalum fragments. The adherence of MSC to either metal was demonstrated by electron microscopy.

RESULTS

Both metals were able to carry MSC when transferred to new culture flasks. In addition, our study shows that culture of MSC with titanium or tantalum improves cell viability and maintains all their biological properties, with no significant differences regarding the metal employed.

CONCLUSION

This would support the use of these combinations for clinical purposes, especially in the spinal fusion and reconstruction setting.