miRNA let-7e targeting MMP9 is involved in adipose-derived stem cell differentiation toward epithelia

miRNA let-7e is involved in stem cell differentiation, and metalloproteinases are among its potential target genes. We hypothesized that the inhibitory action of let-7e on regulation of MMP9 expression could represent a crucial mechanism during differentiation of adipose-derived stem cells (ASCs). ASCs were differentiated with all-trans retinoic acid (ATRA) to promote differentiation, and the effect of let-7 silencing during differentiation was tested. Results indicate that ASCs cultured with ATRA differentiated into cells of the epithelial lineage. We found that ASCs cultured with ATRA or transfected with miRNA let-7e expressed epithelial markers such as cytokeratin-18 and early renal organogenesis markers such as Pax2, Wt1, Wnt4 and megalin. Conversely, the specific knockdown of miRNA let-7e in ASCs significantly decreased the expression of these genes, indicating its vital role during the differentiation process. Using luciferase reporter assays, we also showed that MMP9 is a direct target of miRNA let-7e. Thus, our results suggest that miRNA let-7e acts as a matrix metalloproteinase-9 (MMP9) inhibitor and differentiation inducer in ASCs

miRNA let-7e modulates the Wnt pathway and early nephrogenic markers in mouse embryonic stem cell differentiation

This study indicates that embryonic stem cells [ESCs] cultured with retinoic acid and activin A significantly upregulate the miRNA let-7e. This specific miRNA modulates the Wnt pathway and the expression of early nephrogenic markers under these differentiation conditions. The differentiation markers WT1, Pax2 and Wnt4 were downregulated when miRNA let-7e was silenced, thus indicating the role of miRNA let-7e in the differentiation process. PKCβ, GSK3β phosphorylation (GSK3βP) and β-catenin expression was reduced in differentiated cells and reversed by miRNA let-7e silencing. Addition of a PKCβ inhibitor to the miRNA let-7e silenced cells abolished let-7e-derived effects in differentiation markers, and reversed the increase in GSK3βP and β-catenin, thus indicating that miRNA let-7e is involved in differentiation via the modulation of GSK3β phosphorylation and β-catenin production

miRNA let-7e modulates the wnt pathway and early nephrogenic markers in mouse embryonic stem cell differentiation

This study indicates that embryonic stem cells [ESCs] cultured with retinoic acid and activin A significantly upregulate the miRNA let-7e. This specific miRNA modulates the Wnt pathway and the expression of early nephrogenic markers under these differentiation conditions. The differentiation markers WT1, Pax2 and Wnt4 were downregulated when miRNA let-7e was silenced, thus indicating the role of miRNA let-7e in the differentiation process. PKCβ, GSK3β phosphorylation (GSK3β(P)) and β-catenin expression was reduced in differentiated cells and reversed by miRNA let-7e silencing. Addition of a PKCβ inhibitor to the miRNA let-7e silenced cells abolished let-7e-derived effects in differentiation markers, and reversed the increase in GSK3β(P) and β-catenin, thus indicating that miRNA let-7e is involved in differentiation via the modulation of GSK3β phosphorylation and β-catenin production

Genetically modified macrophages and renal regeneration

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Genetically Modified Macrophages and Renal Regeneration

[spa] Después de la lesión isquémica en el riñón, los macrófagos activados alternativamente o M2 no solo participan en la reparación del daño sino son factores clave en la resolución de la inflamación. La obtención de este fenotipo particular es un proceso controlado por la desregulación de una serie de genes. Modulando estos genes, se podría controlar el fenotipo y las funciones de los macrófagos, con el objetivo de nuevos enfoques en el tratamiento de FRA. El primer objetivo de este estudio fue identificar los genes que están implicados en la reparación de tejidos y que están relacionados con los macrófagos M2. Por genómica funcional hemos identificado la expresión de 14 genes cruciales para la inducción de la capacidad regeneradora endógena del riñón y modulados por la presencia de macrófagos. A continuación hemos demostrado que la modulación del gen Ivns1abp puede modular la reparación renal. En concreto hemos demostrado que la sobre-expresión del gen Ivns1abp en macrófagos puede mejorar su capacidad regenerativa y cambiar su fenotipo hacia M2, provocando la modulación de su estado inflamatorio y aumento de su resistencia frente la inflamación. Se demostró además que el silenciamiento del gen Ivns1abp en macrófagos disminuye su capacidad reparadora y fagocítica transformando su fenotipo a M1. Como ultimo, hemos definido las vías que regulan la transcripción del gen Ivns1abp. Hemos demostrado que la expresión del gen Ivns1abp en los macrófagos está regulada por el factor del trascripción c-myc y modulada por la presencia de citoquinas, determinando el destino de la célula.[eng] After ischemic damage in kidney, alternatively activated or M2 macrophages are key players in resolving inflammation and participating in kidney repair. Obtaining this particular phenotype is a process controlled by deregulation of a series of genes. Modulation of those genes could result in controlling macrophages phenotype and functions, aiming new approaches in resolving ARF. The first aim of this study was to identify genes that are related to M2 macrophages that are involved in tissue repair. By functional genomics we have identified the expression of 14 genes crucial for the induction of the endogenous reparative capacity of the kidney that are modulated by the presence of macrophages. We also demonstrated that modulation of Ivns1abp gene can modulate renal repair. More concrete we show that over-expression of the Ivns1abp gene can enhance macrophages regenerative capacity and switch their phenotype towards M2, provoking modulation of their inflammatory state and increasing its resistance against inflammation inputs. We also demonstrated that silencing of the Ivns1abp genet to macrophages leads them to acquire a M1 phenotype and decrease their reparative and phagocytosis capacity. As a last step, we define pathways that regulate the transcription of the Ivns1abp gene. We show that Ivns1abp gene expression in macrophages is regulated by the c-myc transcription factor and modulated by the presence of cytokines determining cell fate

HIF-1α provokes delayed neutrophil apoptosis by decreasing 24p3 expression and intracellular iron content

Neutrophil apoptosis is delayed in medical conditions associated to anoxia or hypoxia, prolonging tissue destruction and fostering the inflammation. Hypoxia Inducible Factor-1α (HIF-1α), is a main regulator of delayed neutrophil apoptosis but the mechanism of action is poorly characterized. Neutrophil gelatinase-associated lipocalin (24p3) participates actively in iron metabolism and the regulation of iron-responsive genes. Recently, a connection has been described between HIF-1α and 24p3. The purpose of the present study was to determine whether constitutive apoptosis in neutrophils requires 24p3 and whether HIF-1α represses 24p3 affecting cell death iron intracellular levels. To this end we used in vivo ischemic models and anoxic approaches based on the reactivation of the delayed apoptosis. We found that the stabilization of HIF-α during anoxic periods provoked a delay in neutrophil apoptosis through decrease of 24p3 expression and intracellular iron content. The ischemia drastically inhibited the synthesis of 24p3 in circulating neutrophils, increasing the tissue damage. Reactivation of neutrophil apoptosis with opsonized E.coli induced increases in intracellular levels of iron and 24p3. In conclusion, contrary to other cell types, constitutive apoptosis in neutrophils requires 24p3. During hypoxia or ischemia, HIF-1α stabilization represses 24p3 expression, consequently iron levels are depleted and neutrophil apoptosis is delayed. Copyright © by BIOLIFE, s.a.s.Peer Reviewe

miRNA let-7e Modulates the Wnt Pathway and Early Nephrogenic Markers in Mouse Embryonic Stem Cell Differentiation

This study indicates that embryonic stem cells [ESCs] cultured with retinoic acid and activin A significantly upregulate the miRNA let-7e. This specific miRNA modulates the Wnt pathway and the expression of early nephrogenic markers under these differentiation conditions. The differentiation markers WT1, Pax2 and Wnt4 were downregulated when miRNA let-7e was silenced, thus indicating the role of miRNA let-7e in the differentiation process. PKCβ, GSK3β phosphorylation (GSK3βP) and β-catenin expression was reduced in differentiated cells and reversed by miRNA let-7e silencing. Addition of a PKCβ inhibitor to the miRNA let-7e silenced cells abolished let-7e-derived effects in differentiation markers, and reversed the increase in GSK3βP and β-catenin, thus indicating that miRNA let-7e is involved in differentiation via the modulation of GSK3β phosphorylation and β-catenin production. © 2013 Viñas et al.This study has been supported by EU project PROLIGEN (Hypoxic renal Proliferation, LSHBT-CT-2006-036813) , awarded to Georgina Hotter and by grants from Plan Nacional project referenced: SAF 2012-39947-CO2-01 awarded to Georgina Hotter and Fondo de Investigación Sanitaria projects referenced: FIS PS09/01288 and PI 12/00720 awarded to Anna Sola. Anna Sola is supported by Miguel Servet contracting system (CP08/00138)Peer Reviewe

Erythropoietin Delivered for Protection From Acute Kidney Injury May Have Secondary Benefits in Protecting Heart

Póster presentada en el 50th ERA-EDTA Congress (European Renal Association - European Dialysis Transplant Association), celebrado del 18 al 21 de mayo de 2013 en Estambul (Turquía)Abstract publicado en: Nephrology Dialysis Transplantation 28(Supp. 1): i75 (2013) doi: 10.1093/ndt/gft107Peer reviewe

miRNA let 7e regulates stem cell differentiation towards renal lineage

Comunicación presentada en el ERA-EDTA 50th Congress (European Renal Association - European Dialysis Transplant Association), celebrado del 18 al 21 de mayo de 2013 en Estambul (Turquía)Abstract publicado en: Nephrology Dialysis Transplantation 28(Supp. 1): i75 (2013) doi: 10.1093/ndt/gft188Peer Reviewe

Inhibitory action of Wnt target gene osteopontin on mitochondrial cytochrome c release determines renal ischemic resistance

Certain determinants of ischemic resistance in the Brown Norway rat strain have been proposed, but no studies to date have focused on the role of the Wnt pathway in the ischemic resistance mechanism. We performed a comparative genomic study in Brown Norway vs. Sprague-Dawley rats. Selective manipulations of the Wnt pathway in vivo and in vitro allowed us to study whether the action of the Wnt pathway on apoptosis through the regulation of osteopontin was critical to the maintenance of inherent ischemic resistance mechanisms. The results revealed a major gene upregulation of the Wnt family in Brown Norway rats after renal ischemia-reperfusion. Manipulation of the Wnt signaling cascade by selective antibodies increased mitochondrial cytochrome c release and caspase 3 activity. The antiapoptotic role of Wnt was mediated by osteopontin, a direct Wnt target gene. Osteopontin was reduced by Wnt antibody administration in vivo, and osteopontin gene silencing in vitro significantly increased mitochondrial cytochrome c release. The overexpression of Wnt pathway genes detected in Brown Norway rats is critical in the maintenance of their inherent ischemic resistance. Activation of the Wnt signaling cascade reduces mitochondrial cytochrome c release and caspase 3 activity through the action of osteopontin. Copyright © 2010 the American Physiological Society.This work was supported by EU Grant LSHB-CT-2006-036813 (to G. Hotter), FISS PS09/00057 (to G. Hotter), 2009 SGR 1094 (to G. Hotter), FISS PS09/01288 (to A. Sola), and Miguel Servet CP08/00138 (to A. Sola). C. Mastora is supported by the University of Barcelona.Peer Reviewe