Células madre Mesenquimales de tejido adiposo como tratamiento de la superficie ocular en la deficiencia de células madre limbares

En este trabajo, se ha abordado el estudio de la capacidad que tienen las células madre mesenquimales de tejido adiposo humano (hAT-MSCs) para reparar la superficie ocular en casos de fracaso de la misma por deficiencia de células madre límbicas. Para ello, se han realizado ensayos in vitro, ex vivo e in vivo. En primer lugar, se ha estudiado la capacidad que tienen estas células para diferenciarse in vitro a células con características similares a las epiteliales corneales. En segundo lugar, se ha estudiado la dosis celular más adecuada para su trasplante sobre la superficie ocular en un modelo de daño corneal por causticación en ojo de cerdo ex vivo. Por último, se han desarrollado tres modelos animales de síndrome de insuficiencia límbica (SIL) en los que se ha estudiado la tolerancia y la eficacia del trasplante de hAT-MSCs para regenerar la superficie ocular dañada. Los resultados obtenidos mostraron que las hAT-MSCs pueden adquirir un fenotipo similar al de las células epiteliales corneales cuando estas son cultivadas in vitro con factores secretados por células epiteliales corneales diferenciadas.2017-06-3

Poly-l/dl-lactic acid films functionalized with collagen IV as carrier substrata for corneal epithelial stem cells

Limbal epithelial stem cells (LESCs) are responsible for the renewal of corneal epithelium. Cultivated limbal epithelial transplantation is the current treatment of choice for restoring the loss or dysfunction of LESCs. To perform this procedure, a substratum is necessary for in vitro culturing of limbal epithelial cells and their subsequent transplantation onto the ocular surface. In this work, we evaluated poly-L/DL-lactic acid 70:30 (PLA) films functionalized with type IV collagen (col IV) as potential in vitro carrier substrata for LESCs. We first demonstrated that PLA-col IV films were biocompatible and suitable for the proliferation of human corneal epithelial cells. Subsequently, limbal epithelial cell suspensions, isolated from human limbal rings, were cultivated using culture medium that did not contain animal components. The cells adhered significantly faster to PLA-col IV films than to tissue culture plastic (TCP). The mRNA expression levels for the LESC specific markers, K15, P63α and ABCG2 were similar or greater (significantly in the case of K15) in limbal epithelial cells cultured on PLA-col IV films than limbal epithelial cells cultured on TCP. The percentage of cells expressing the corneal (K3, K12) and the LESC (P63α, ABCG2) specific markers was similar for both substrata. These results suggest that the PLA-col IV films promoted LESC attachment and helped to maintain their undifferentiated stem cell phenotype. Consequently, these substrata offer an alternative for the transplantation of limbal cells onto the ocular surface.This work was supported by the Carlos III National Institute of Health, Spain (CIBER-BBN and Spanish Network on Cell Therapy, (TerCel RD12/0019/0036), MINECO/FEDER, EU), and the Castilla y León Regional Government, Spain (Regional Center for Regenerative Medicine and Cell Therapy, SAN673/VA/28/08 and SAN126/VA11/09)

Therapeutic Effect of Human Adipose Tissue-Derived Mesenchymal Stem Cells in Experimental Corneal Failure Due to Limbal Stem Cell Niche Damage

Producción CientíficaLimbal stem cells are responsible for the continuous renewal of the corneal epithelium. The destruction or dysfunction of these stem cells or their niche induces limbal stem cell deficiency (LSCD) leading to visual loss, chronic pain, and inflammation of the ocular surface. To restore the ocular surface in cases of bilateral LSCD, an extraocular source of stem cells is needed to avoid dependence on allogeneic limbal stem cells that are difficult to obtain, isolate, and culture. The aim of this work was to test the tolerance and the efficacy of human adipose tissue-derived mesenchymal stem cells (hAT-MSCs) to regenerate the ocular surface in two experimental models of LSCD that closely resemble the different severity grades of the human pathology. hAT-MSCs transplanted to the ocular surface of the partial and total LSCD models developed in rabbits were well tolerated, migrated to inflamed tissues, reduced inflammation, and restrained the evolution of corneal neovascularization and corneal opacity. The expression profile of the corneal epithelial cell markers CK3 and E-cadherin, and the limbal epithelial cell markers CK15 and p63 was lost in the LSCD models, but was partially recovered after hAT-MSC transplantation. For the first time, we demonstrated that hAT-MSCs improves corneal and limbal epithelial phenotypes in animal LSCD models. These results support the potential use of hAT-MSCs as a novel treatment of ocular surface failure due to LSCD. hAT-MSCs represent an available, non-immunogenic source of stem cells that may provide therapeutic benefits in addition to reduce health care expenses.This work was supported by Instituto de Salud Carlos III, CIBER‐BBN, Spain (CB06/01/003 MINECO/FEDER, EU); Regional Center for Regenerative Medicine and Cell Therapy, Castilla y León, Spain; Ministry of Science and Innovation, Spain (SAF2010–14900); Ministry of Economy and Competitiveness and European Regional Development Fund, Spain (SAF2015–63594‐R MINECO/FEDER, EU

Consecutive Expansion of Limbal Epithelial Stem Cells from a Single Limbal Biopsy

Producción CientíficaPurpose: Corneal epithelium is maintained by limbal epithelial stem cells (LESCs), the loss of which can be catastrophic for corneal transparency. Effective therapies include the transplantation of cultivated LESCs, requiring optimization of in vitro cultivation protocols. Unfortunately, optimization studies are hampered by the limited number of ocular tissue donors. We investigated the feasibility of obtaining more than one limbal primary culture (LPC) from the same 1-2 mm2 limbal explant (LE). Methods: LEs were plated and maintained until outgrowth surrounded each, being removed at this point. LPCs were allowed to reach confluence (LPC0). The same removed LE was plated again, following the same procedure, obtaining LPC1. This procedure was repeated as often as possible up to 6 times. LPCs from each passage were analysed by real time RT-PCR and immunofluorescence-microscopy. Results: LPCs from LPC0 to LPC2 presented an heterogeneous cell population, with cells positive for LESC markers K14, K15, ABCG2 and p63, differentiated corneal epithelial cell-specific markers K3 and K12, and for the fibroblast marker S100A4. These cells had an epithelial-like morphology. In LPC3-LPC4, elongated cell morphology appeared, and the presence of LESC markers decreased, while the presence of differentiated corneal epithelial-cell and fibroblast markers increased. Conclusion: one LE can be successfully cultivated up to three consecutive times while maintaining the LESC phenotype in the LPC cells. This protocol provides several homologous LPCs for basic research. Additionally, by using a cell-carrier, the resulting LPCs could serve reservoirs for potential autologous expanded LESC transplantations and/or for making correlations between laboratory and clinical outcomes.This study was supported by CIBER-BBN, Spain and Network Center for Regeneration Medicine and Cell Therapy, Castile and Leon Government (SAN673/VA/28/08 and SAN/103/2011). M. L-P. and S. G. were supported by scholarships co-financed by the Castile and Leon Government and the European-Social-Fond

Eficacia del trasplante de células madre mesenquimales de médula ósea y de tejido adiposo en un modelo de deficiencia de células madre limbares desarrollado en conejo: estudio comparativo

INTRODUCCIÓN: La deficiencia de células madre limbares (LSCD, por sus siglas en inglés) se produce como resultado de la destrucción y/o disfunción de las células madre del epitelio limbar, y tiene entre sus consecuencias la pérdida de visión y la inflamación crónica de la superficie ocular. Nuestro grupo de investigación ha demostrado recientemente que el trasplante de células madre mesenquimales (MSC) derivadas de la médula ósea (BM-MSC) en la superficie ocular de pacientes que padecen LSCD es seguro y facilita de manera eficaz la reparación del epitelio corneal. Sin embargo, las MSC derivadas del tejido adiposo (AT-MSC) se ha demostrado que son más accesibles, más económicas y una fuente de células madre más segura que las BM-MSC. OBJETIVO: Comparar la eficacia del trasplante de BM-MSC versus AT-MSC en un modelo de LSCD desarrollado en conejo. MÉTODOS: Dieciocho conejos fueron tratados con 250.000 MSC cultivadas sobre una membrana amniótica (9 con BM-MSC y 9 con AT-MSC) y trasplantadas tres semanas después de inducirles un LSCD. Mediante desepitelización completa de la córnea con n-heptanol, seguida de una peritomía limbar quirúrgica de 360º, se indujo un modelo de LSCD en 27 conejos. Transcurridas 3 semanas de evolución, 18 conejos fueron trasplantados con 250.000 MSC cultivadas sobre una membrana amniótica (9 con BM-MSC y 9 con AT-MSC). Nueve conejos no trasplantados formaron el grupo de control. Semanalmente, se evaluó clínicamente la invasión conjuntival, la neovascularización, la opacidad y el defecto epitelial corneal con una lámpara de hendidura. Mediante un análisis histopatológico realizado al final del periodo del seguimiento (11 semanas), se evaluó el nivel de daño tisular y la presencia de linfocitos (como signo de inflamación) y de células caliciformes (como signo de conjuntivalización) en el limbo y en la córnea. RESULTADOS: El grupo trasplantado con BM-MSC mostró menos neovascularización y menos opacidad corneal en las semanas 6-8 y 6-9, respectivamente, que el grupo no tratado. El grupo tratado con AT-MSC tuvo menos invasión conjuntival y opacidad corneal en las semanas 6-8 y 6-10, respectivamente, que el grupo de control. No hubo diferencias en los defectos epiteliales entre los 3 grupos. Los grupos trasplantados con BM-MSC y AT-MSC mostraron un mayor número de capas epiteliales en la córnea y en el limbo, menos desorganización del estroma, menor cantidad de células inflamatorias en el estroma de la córnea y menos células caliciformes en el epitelio del limbo y/o de la córnea que el grupo no tratado. CONCLUSIONES: El trasplante de BM-MSC y AT-MSC en un modelo de LSCD desarrollado en conejo redujo el desarrollo de la opacidad corneal y restauró parcialmente la estructura dañada del tejido limbar y corneal. Las BM-MSC fueron mejores en la reducción del desarrollo de la neovascularización corneal, mientras que las AT-MSC evitaron mejor la invasión conjuntival. Ambos tipos de MSC parecen alternativas válidas para el tratamiento de la LSCD.Ministerios de Economía y Competitividad (SAF2015-63594-R MINECO/FEDER, UE) y de Ciencia e Innovación, España (SAF2010-14900); Instituto de Salud Carlos III, España (CIBER-BBN, CB06/01/003 MINECO/FEDER). Centro en Red de Medicina Regenerativa y Terapia Celular de Castilla y León, España

A proof-of-concept clinical trial using mesenchymal stem cells for the treatment of corneal epithelial stem cell deficiency

Producción CientíficaOcular stem cell transplantation derived from either autologous or allogeneic donor corneoscleral junction is a functional cell therapy to manage extensive and/or severe limbal stem cell deficiencies that lead to corneal epithelial failure. Mesenchymal stem cells have been properly tested in animal models of this ophthalmic pathology, but never in human eyes despite their potential advantages. We conducted a 6- to 12-month proof-of-concept, randomized, and double-masked pilot trial to test whether allogeneic bone marrow-derived mesenchymal stem cell transplantation (MSCT], n = 17) was as safe and as equally efficient as allogeneic cultivated limbal epithelial transplantation (CLET), (n = 11) to improve corneal epithelial damage due to limbal stem cell deficiency. Primary endpoints demanded combination of symptoms, signs, and the objective improvement of the epithelial phenotype in central cornea by in vivo confocal microscopy. This proof-of-concept trial showed that MSCT was as safe and efficacious as CLET. Global success at 6–12 months was 72.7%–77.8% for CLET cases and 76.5%–85.7% for MSCT cases (not significant differences). Central corneal epithelial phenotype improved in 71.4% and 66.7% of MSCT and CLET cases, respectively at 12 months (P = 1.000). There were no adverse events related to cell products. This trial suggests first evidence that MSCT facilitated improvement of a diseased corneal epithelium due to lack of its stem cells as efficiently as CLET. Consequently, not only CLET but also MSCT deserves more preclinical investigational resources before the favorable results of this proof-of-concept trial could be transformed into the larger numbers of the multicenter trials that would provide stronger evidence. (ClinicalTrials.gov number, NCT01562002.)Ministerio de Sanidad, Consumo y Bienestar Social (project SAS/2481/2009)Centro en Red de Medicina Regenerativa y Terapia Celular de Castilla y León (grant SAN 1178/200)Red de Terapia Celular TerCel (project RD12/0019/0036

Corneal regeneration using adipose-derived mesenchymal stem cells

Producción CientíficaAdipose-derived stem cells are a subtype of mesenchymal stem cell that offers the important advantage of being easily obtained (in an autologous manner) from low invasive procedures, rendering a high number of multipotent stem cells with the potential to differentiate into several cellular lineages, to show immunomodulatory properties, and to promote tissue regeneration by a paracrine action through the secretion of extracellular vesicles containing trophic factors. This secretome is currently being investigated as a potential source for a cell-free based regenerative therapy for human tissues, which would significantly reduce the involved costs, risks and law regulations, allowing for a broader application in real clinical practice. In the current article, we will review the existing preclinical and human clinical evidence regarding the use of such adipose-derived mesenchymal stem cells for the regeneration of the three main layers of the human cornea: the epithelium (derived from the surface ectoderm), the stroma (derived from the neural crest mesenchyme), and the endothelium (derived from the neural crest cells)

Adopting a High-Polyphenolic Diet Is Associated with an Improved Glucose Profile: Prospective Analysis within the PREDIMED-Plus Trial

Previous studies suggested that dietary polyphenols could reduce the incidence and complications of type-2 diabetes (T2D); although the evidence is still limited and inconsistent. This work analyzes whether changing to a diet with a higher polyphenolic content is associated with an improved glucose profile. At baseline, and at 1 year of follow-up visits, 5921 participants (mean age 65.0 ± 4.9, 48.2% women) who had overweight/obesity and metabolic syndrome filled out a validated 143-item semi-quantitative food frequency questionnaire (FFQ), from which polyphenol intakes were calculated. Energy-adjusted total polyphenols and subclasses were categorized in tertiles of changes. Linear mixed-effect models with random intercepts (the recruitment centers) were used to assess associations between changes in polyphenol subclasses intake and 1-year plasma glucose or glycosylated hemoglobin (HbA1c) levels. Increments in total polyphenol intake and some classes were inversely associated with better glucose levels and HbA1c after one year of follow-up. These associations were modified when the analyses were run considering diabetes status separately. To our knowledge, this is the first study to assess the relationship between changes in the intake of all polyphenolic groups and T2D-related parameters in a senior population with T2D or at high-risk of developing T2

Clonal chromosomal mosaicism and loss of chromosome Y in elderly men increase vulnerability for SARS-CoV-2

The pandemic caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2, COVID-19) had an estimated overall case fatality ratio of 1.38% (pre-vaccination), being 53% higher in males and increasing exponentially with age. Among 9578 individuals diagnosed with COVID-19 in the SCOURGE study, we found 133 cases (1.42%) with detectable clonal mosaicism for chromosome alterations (mCA) and 226 males (5.08%) with acquired loss of chromosome Y (LOY). Individuals with clonal mosaic events (mCA and/or LOY) showed a 54% increase in the risk of COVID-19 lethality. LOY is associated with transcriptomic biomarkers of immune dysfunction, pro-coagulation activity and cardiovascular risk. Interferon-induced genes involved in the initial immune response to SARS-CoV-2 are also down-regulated in LOY. Thus, mCA and LOY underlie at least part of the sex-biased severity and mortality of COVID-19 in aging patients. Given its potential therapeutic and prognostic relevance, evaluation of clonal mosaicism should be implemented as biomarker of COVID-19 severity in elderly people. Among 9578 individuals diagnosed with COVID-19 in the SCOURGE study, individuals with clonal mosaic events (clonal mosaicism for chromosome alterations and/or loss of chromosome Y) showed an increased risk of COVID-19 lethality