Browsing by Author "Ibáñez Torres, Lidia"

The use of mesenchymal stem cells constitutes a promising therapeutic approach, as it has shown beneficial effects in different pathologies. Numerous in vitro, pre-clinical, and, to a lesser extent, clinical trials have been published for osteoarthritis. Osteoarthritis is a type of arthritis that affects diarthritic joints in which the most common and studied effect is cartilage degradation. Nowadays, it is known that osteoarthritis is a disease with a very powerful inflammatory component that affects the subchondral bone and the rest of the tissues that make up the joint. This inflammatory component may induce the differentiation of osteoclasts, the bone-resorbing cells. Subchondral bone degradation has been suggested as a key process in the pathogenesis of osteoarthritis. However, very few published studies directly focus on the activity of mesenchymal stem cells on osteoclasts, contrary to what happens with other cell types of the joint, such as chondrocytes, synoviocytes, and osteoblasts. In this review, we try to gather the published bibliography in relation to the effects of mesenchymal stem cells on osteoclastogenesis. Although we find promising results, we point out the need for further studies that can support mesenchymal stem cells as a therapeutic tool for osteoclasts and their consequences on the osteoarthritic joint.

Bone destruction relies on interactions between bone and immune cells. Bone- resorbing osteoclasts (OCLs) were recently identified as innate immune cells activating T cells toward tolerance or inflammation. Thus, pathological bone destruction not only relies on increased osteoclast differentiation, but also on the presence of inflammatory OCLs (i-OCLs), part of which express Cx3cr1. Here, we investigated the contribution of mouse Cx3cr1+ and Cx3cr1neg i-OCLs to bone loss. We showed that Cx3cr1+ and Cx3cr1neg i-OCLs differ considerably in transcriptional and functional aspects. Cx3cr1neg i-OCLs have a high ability to resorb bone and activate inflammatory CD4+ T cells. Although Cx3cr1+ i-OCLs are associated with inflammation, they resorb less and have in vitro an immune-suppressive effect on Cx3cr1neg i-OCLs, mediated by PD-L1. Our results provide new insights into i-OCL heterogeneity. They also reveal that different i-OCL subsets may interact to regulate inflammation. This contributes to a better understanding and prevention of inflammatory bone destruction.

Osteoclasts (OCLs) are key players in controlling bone remodeling. Modifications in their differentiation or bone resorbing activity are associated with a number of pathologies ranging from osteopetrosis to osteoporosis, chronic inflammation and cancer, that are all characterized by immunological alterations. Therefore, the 2000s were marked by the emergence of osteoimmunology and by a growing number of studies focused on the control of OCL differentiation and function by the immune system. At the same time, it was discovered that OCLs are much more than bone resorbing cells. As monocytic lineage-derived cells, they belong to a family of cells that displays a wide heterogeneity and plasticity and that is involved in phagocytosis and innate immune responses. However, while OCLs have been extensively studied for their bone resorption capacity, their implication as immune cells was neglected for a long time. In recent years, new evidence pointed out that OCLs play important roles in the modulation of immune responses toward immune suppression or inflammation. They unlocked their capacity to modulate T cell activation, to efficiently process and present antigens as well as their ability to activate T cell responses in an antigen-dependent manner. Moreover, similar to other monocytic lineage cells such as macrophages, monocytes and dendritic cells, OCLs display a phenotypic and functional plasticity participating to their anti-inflammatory or pro-inflammatory effect depending on their cell origin and environment. This review will address this novel vision of the OCL, not only as a phagocyte specialized in bone resorption, but also as innate immune cell participating in the control of immune responses.

La clase invertida es un modelo pedagógico creado en 2012 por Jonathan Bergmann y Aaron Sams, profesores de Química en Woodland Park High School (Woodland Park Colorado). En este modelo, el profesor, en lugar de utilizar el tiempo de la clase para introducir nueva materia (vía lección magistral), previamente a que tenga lugar la clase proporciona a los alumnos, a través de la plataforma virtual, material docente (videos, artículos, podcast, etc.) para ayudarles a clarificar la materia objeto de estudio, de manera que puede utilizar el tiempo de la clase para realizar actividades docentes colaborativas. El material docente debe incluir las ideas principales de la unidad de estudio y puede ser creado por el profesor o descargado de internet. Esta actividad se ha desarrollado en el primer cuatrimestre del curso 2018-19 en las asignaturas Farmacología Clínica en el Grado de Farmacia y Farmacología del Grado en Medicina. Basándonos en los resultados obtenidos, la actividad ha resultado muy interesante para los estudiantes. La clase invertida les ha ayudado a clarificar conceptos y algunos estudiantes han considerado que tener conocimientos previos es importante para realizar la actividad, aunque no es esencial. / Flipped classroom is a pedagogical model created in 2012 by Jonathan Bergmann and Aaron Sams, Chemistry teachers at Woodland Park High School (Woodland Park Colorado). In this model, rather than taking up limited class time to explain a new concept (often via lecture), the teacher add a variety of learning material (videos, articles, podcast. etc.) to Blackboard before class. The objective is to introduce students to the concepts that they are going to study during class, freeing up class time for more collaborative activities. Learning material includes main concepts and ideas of the unit of study and it can be produced originally by the teacher or it can be acquired from internet. The activity has been carried out during the first semester of the academic year 2018-19 in the subjects Clinical Pharmacology and Pharmacology in Pharmacy and Medicine degrees, respectively. Acquired knowledge of students was evaluated by Kahoot tests and a survey was conducted to analyse the student’s opinion about the activity. Kahoot results showed that 80 of the students pass the test. On the other hand, based on the results of the survey, the activity proved to be very interesting for the students. The flipped classroom helped them to clarify concepts and many of them considered that having previous theoretical background is important to understand the activity, although it is not essential.

Osteoarthritis (OA) is a degenerative condition of the articular cartilage with chronic low-grade inflammation. Monocytes have a fundamental role in the progression of OA, given their implication in inflammatory responses and their capacity to differentiate into bone-resorbing osteoclasts (OCLs). This observational–experimental study attempted to better understand the molecular pathogenesis of OA through the examination of osteoclast progenitor (OCP) cells from both OA patients and healthy individuals (25 OA patients and healthy samples). The expression of osteoclastogenic and inflammatory genes was analyzed using RT-PCR. The OA monocytes expressed significantly higher levels of CD16, CD115, TLR2, Mincle, Dentin-1, and CCR2 mRNAs. Moreover, a flow cytometry analysis showed a significantly higher surface expression of the CD16 and CD115 receptors in OA vs. healthy monocytes, as well as a difference in the distribution of monocyte subsets. Additionally, the OA monocytes showed a greater osteoclast differentiation capacity and an enhanced response to an inflammatory stimulus. The results of this study demonstrate the existence of significant differences between the OCPs of OA patients and those of healthy subjects. These differences could contribute to a greater understanding of the molecular pathogenesis of OA and to the identification of new biomarkers and potential drug targets for OA.

Parathyroid hormone-related protein (PTHrP) C-terminal peptides regulate the metabolism of bone cells. PHTrP [107–111] (osteostatin) promotes bone repair in animal models of bone defects and prevents bone erosion in inflammatory arthritis. In addition to its positive effects on osteoblasts, osteostatin may inhibit bone resorption. The aim of this study was to determine the effects of osteostatin on human osteoclast differentiation and function. We used macrophage colony-stimulating factor (M-CSF) and receptor activator of nuclear factor B ligand (RANKL) to induce the osteoclast differentiation of adherent human peripheral blood mononuclear cells. Tartrate-resistant acid phosphatase (TRAP) staining was performed for the detection of the osteoclasts. The function of mature osteoclasts was assessed with a pit resorption assay. Gene expression was evaluated with qRT-PCR, and nuclear factor of activated T cells, cytoplasmic 1 (NFATc1) nuclear translocation was studied by immunofluorescence. We observed that osteostatin (100, 250 and 500 nM) decreased the differentiation of osteoclasts in a concentration-dependent manner, but it did not modify the resorptive ability of mature osteoclasts. In addition, osteostatin decreased the mRNA levels of cathepsin K, osteoclast associated Ig-like receptor (OSCAR) and NFATc1. The nuclear translocation of the master transcription factor in osteoclast differentiation NFATc1 was reduced by osteostatin. Our results suggest that the anti-resorptive effects of osteostatin may be dependent on the inhibition of osteoclastogenesis. This study has shown that osteostatin controls human osteoclast differentiation in vitro through the downregulation of NFATc1.

Intestinal mononuclear phagocytes (MPs) comprise dendritic cells (DCs) and macrophages (M0s) that play different roles in response to Salmonella infection. After phagocytosis, DCs expressing CD103 transport Salmonella from the intestinal tract to the mesenteric lymph nodes (MLN) and induce adaptive immune responses whereas resident M0s expressing CX3CR1 capture bacteria in the lumen and reside in the lamina propria (LP) where they induce a local immune response. CX3CR1+ M0s are generated from Ly6Chi monocytes that enter the colonic mucosa and differentiate locally. We previously demonstrated that the probiotic yeast Saccharomyces boulardii CNCM I-745 (S.b) prevents infection by Salmonella enterica serovar Typhimurium (ST), decreases ST translocation to the peripheral organs and modifies the pro-and anti-inflammatory cytokine profiles in the gut. In the present study, we investigated the effect of S.b on the migratory CD103+ DCs and the resident CX3CR1+ M0s. MPs were isolated from the LP of streptomycin-treated mice infected by ST with or without S.b treatment before or during the infection. In S.b-pretreated mice, we observed a decrease of the CD103+ DCs in the LP that was associated with the drop of ST recovery from MLN. Interestingly, S.b induced an infiltration of LP by classical Ly6Chi monocytes, and S.b modified the monocyte-M0 maturation process in ST-infected mice. Our results showed that S.b treatment induced the expansion of Ly6Chi monocytes in the blood as well as in the bone marrow (BM) of mice, thus contributing to the M0 replenishment in LP from blood monocytes. In vitro experiments conducted on BM cells confirmed that S.b induced the expansion of CX3CR1+ M0s and concomitantly ST phagocytosis. Altogether, these data demonstrate that Saccharomyces boulardii CNCM I-745 modulates the innate immune response. Although here, we cannot explicitly delineate direct effects on ST from innate immunity, S. b-amplified innate immunity correlated with partial protection from ST infection. This study shows that S.b can induce the expansion of classical monocytes that are precursors of resident M0s in the LP.

Existen diversas herramientas informáticas aplicadas a mejorar la eficacia de los sistemas de evaluación. Zipgrade es un soporte informático, para uso en PC, tablet o como aplicación en el móvil, para la corrección y análisis automático de pruebas de tipo test. Las opciones que permite esta aplicación son: -Crear y editar respuestas clave. -Escanear las plantillas de respuesta con el teléfono móvil para corregir los exámenes. -Revisar los documentos que han sido escaneados. -Obtrner listados con las calificaciones de los alumnos. -Analizar la información de los datos escaneados (Opción Item analysis). -Resolver dudas en la web http://www.zipgrade.com Hemos querido comprobar si esta herramienta supone un avance en la mejora de la realización de pruebas de test y, en definitiva, en el sistema de corrección y evaluación de estas pruebas. Para ello se ha empleado esta aplicación en la corrección de una prueba realizada a 135 alumnos. La corrección de la prueba se realizó con el móvil, escaneando alrededor de 15 pruebas por minuto. Esta aplicación ha sido de gran utilidad por la reducción de errores en la corrección, la rapidez en la obtención de los resultados y el análisis exhaustivo de la estadística referente a los mismos. / There are different digital assessment tools that has been developed to improve the evaluation methods. Zipgrade is an ICT toll that is available on computer, phone or tablet; and it works as an optical grading machine. The tool will allow the user to: - Create new quiz and define key - Scan and grade examns using the phone camera - Create student grade sheets - Review graded papers and analyze them (Item analysis) - Solve any doubts on its website http://www.zipgrade.com We have studied if the use of Zipgrade improves the efficiency of multiplechoice question (MCQ) tests and their assessment methods. We have used Zipgrade to correct a MCQ test made by 135 students. Test grading was performed scanning the answer sheets using the camera what allowed to correct 15 test per minute. The use of Zipgrade has reduced the errors produced during the correction process and the time required to grade all tests. Moreover, it has been very useful for the exhaustive statistical analysis of the answers of the tests.