1,720,996 research outputs found
Epithelial-mesenchymal transition (EMT) of renal tubular cells in canine glomerulonephritis.
No full textTubulo-interstitial fibrosis in dogs may result from primary injury to the interstitium or develop secondary to other renal diseases. As in human renal pathology, tubular epithelial cells (TEC) are believed to actively participate in the mechanisms of renal fibrosis. In this study, we examined the changes in the tubular epithelial component in two specific canine diseases. Immunohistochemistry showed the expression of the epithelial marker cytokeratin, the smooth muscle marker alpha-SMA, the mesenchymal marker vimentin and PCNA in 20 dogs with membranous glomerulonephritis and membrano-proliferative glomerulonephritis. Results showed that the loss of the epithelial marker in TEC was directly correlated to the grade of tubulo-interstitial disease present and independent of the type of glomerulonephritis. Varying degrees of vimentin positivity were detected in tubular epithelium in areas of inflammation, and low numbers of scattered alpha-SMA-positive cells were also observed. Immunohistochemistry showed that epithelial tubular cells lose their cytokeratin staining characteristics and transdifferentiate into cells exhibiting key mesenchymal immunophenotypic feature of vimentin-positive staining in both diseases investigated. The integrity of the tubular basement membrane is likely to be fundamental in maintaining the epithelial phenotype of TEC. Animal models provide opportunities for investigating the pathogenesis of renal fibrosis in humans
Glomerular barrier function impairment In Milan rats with experimental diabetes : role of renal hemodynamics
No full textRostafuroxin protects from podocyte injury and proteinuria induced by adducin genetic variants and ouabain
No full textNovel model of in vitro osteocytogenesis induced by retinoic acid treatment
No full textDespite recent research which more and more stresses the importance of osteocytes in regulating bone and systemic mineral metabolism, current molecular and functional knowledge of osteocyte properties are still incomplete, mostly due to limited availability of in vitro models. Osteocytes are terminally differentiated dendritic cells, and therefore are not easy to obtain and maintain in primary cultures. As an alternative, osteocyte differentiation can be induced by progressive osteoblast embedding in mineralised extracellular matrix. In this model, which is suitable for reproduction of bone development, the presence of calcified matrix prevents several cell biological methods from being used. Therefore, the osteocyte-like MLO-Y4 cell line continues to be the most widely used cellular system. Here we show that treatment of primary osteoblasts or MC3T3-E1 cells with retinoic acid generates a homogeneous population of ramified cells with osteocyte features, as confirmed by morphological and molecular analyses. The first morphological changes are detectable in primary cells after 2 days of treatment, and in the cell line after 4 days of treatment. Differentiation is complete in 5 and 10 days, respectively, with progressive development of dendrites, loss of the ability to produce extracellular matrix, down-regulation of osteoblast markers, and up-regulation of osteocyte-specific molecules, most notably among them sclerostin. Compared to other published protocols, our method has a number of advantages. It is easy to perform and does not require special instrumentation, it is highly reproducible, and rapidly generates a mature osteocyte population in the complete absence of extracellular matrix, allowing the use of these cells for unlimited biological applications
Alterazioni della funzione di barriera glomerulare in ratti Milano resi diabetici: ruolo dell’emodinamica renale.
No full textIl Diabete, Supplemento n.1, Marzo 200
Bone marrow-derived stem cells repopulate glomerular and tubular kidney components - Effect of hyperglycemia
No full textRole of TGF-ß/GLUT1 axis in susceptibility vs. resistance to diabetic glomerulopathy in the Milan rat model.
No full textA nanoporous surface is essential for glomerular podocyte differentiation in three-dimensional culture.
Full text linkAlthough it is well recognized that cell-matrix interactions are based on both molecular and geometrical characteristics, the relationship between specific cell types and the three-dimensional morphology of the surface to which they are attached is poorly understood. This is particularly true for glomerular podocytes - the gatekeepers of glomerular filtration - which completely enwrap the glomerular basement membrane with their primary and secondary ramifications. Nanotechnologies produce biocompatible materials which offer the possibility to build substrates which differ only by topology in order to mimic the spatial organization of diverse basement membranes. With this in mind, we produced and utilized rough and porous surfaces obtained from silicon to analyze the behavior of two diverse ramified cells: glomerular podocytes and a neuronal cell line used as a control. Proper differentiation and development of ramifications of both cell types was largely influenced by topographical characteristics. Confirming previous data, the neuronal cell line acquired features of maturation on rough nanosurfaces. In contrast, podocytes developed and matured preferentially on nanoporous surfaces provided with grooves, as shown by the organization of the actin cytoskeleton stress fibers and the proper development of vinculin-positive focal adhesions. On the basis of these findings, we suggest that in vitro studies regarding podocyte attachment to the glomerular basement membrane should take into account the geometrical properties of the surface on which the tests are conducted because physiological cellular activity depends on the three-dimensional microenvironment
The Directed Differentiation of Human iPS Cells into Kidney Podocytes
Full text linkThe loss of glomerular podocytes is a key event in the progression of chronic kidney disease resulting in proteinuria and declining function. Podocytes are slow cycling cells that are considered terminally differentiated. Here we provide the first report of the directed differentiation of induced pluripotent stem (iPS) cells to generate kidney cells with podocyte features. The iPS-derived podocytes share a morphological phenotype analogous with cultured human podocytes. Following 10 days of directed differentiation, iPS podocytes had an up-regulated expression of mRNA and protein localization for podocyte markers including synaptopodin, nephrin and Wilm's tumour protein (WT1), combined with a down-regulation of the stem cell marker OCT3/4. In contrast to human podocytes that become quiescent in culture, iPS-derived cells maintain a proliferative capacity suggestive of a more immature phenotype. The transduction of iPS podocytes with fluorescent labeled-talin that were immunostained with podocin showed a cytoplasmic contractile response to angiotensin II (AII). A permeability assay provided functional evidence of albumin uptake in the cytoplasm of iPS podocytes comparable to human podocytes. Moreover, labeled iPS-derived podocytes were found to integrate into reaggregated metanephric kidney explants where they incorporated into developing glomeruli and co-expressed WT1. This study establishes the differentiation of iPS cells to kidney podocytes that will be useful for screening new treatments, understanding podocyte pathogenesis, and offering possibilities for regenerative medicine
- …
