ABSTRACT
Renal fibrosis is characterized by glomerulosclerosis and tubulointerstitial fibrosis and its pathogenesis is associated with the activity of mesenchymal cells (fibroblasts), being essentially characterized by a process of excessive accumulation resulting from the deposition of extracellular matrix components. The aim of this study was to characterize the morphological presentation of chronic and fibrotic lesions in the glomerular, tubular, interstitial, and vascular compartments in feline CKD, as well as the possible participation of myofibroblasts in renal fibrotic processes in this species. Cat kidneys were collected and processed according to the conventional techniques for light microscopy, circular polarization, immunohistochemistry, and electron microscopy. Fibrotic alterations were present in all compartments analyzed. The main findings in the glomerular compartment were different degrees of glomerular sclerosis, synechia formation, Bowman's capsule calcification, in addition to glomerular basement membrane thickening and pericapsular fibrosis. The tubulointerstitial compartment had intense tubular degeneration and the immunostaining in tubular cells for mesenchymal cell markers demonstrated the possibility of mesenchymal epithelial transition and consequent involvement of myofibroblasts in the development of interstitial tubule damage. Infiltration of inflammatory cells, added to vessel thickening and fibrosis, demonstrated the severity and role of inflammation in the development and perpetuation of damage. Thus, we may conclude that fibrotic lesions play a relevant role in feline CKD and the mechanism of perpetuation of these lesions need further elucidation regarding the origin and participation of myofibroblasts and consequent mesenchymal epithelial transition in this species.
Subject(s)
Cat Diseases/pathology , Kidney/pathology , Renal Insufficiency, Chronic/veterinary , Actins/ultrastructure , Animals , Cats , Collagen/ultrastructure , Extracellular Matrix/ultrastructure , Female , Fibroblasts/ultrastructure , Fibrosis/veterinary , Immunohistochemistry/methods , Immunohistochemistry/veterinary , Inflammation/veterinary , Kidney/ultrastructure , Kidney Glomerulus/pathology , Kidney Glomerulus/ultrastructure , Male , Microscopy/methods , Microscopy/veterinary , Microscopy, Confocal/veterinary , Microscopy, Electron/veterinary , Microscopy, Polarization/veterinary , Myofibroblasts/ultrastructure , Renal Insufficiency, Chronic/pathologyABSTRACT
Reprogramming of human somatic cells by transcription factors to pluripotent state holds great promise for regenerative medicine. However, low efficiencies of current reprogramming methods, immunogenicity and lack of understanding regarding the molecular mechanisms responsible for their generation, limits their utilization and raises questions regarding safety for therapeutic application. Here we report that ACA signaling via PI3K/Akt/mTor induces sustained de-differentiation of human blood progenitor cells leading to generation of ACA pluripotent stem cells. Blood-derived pluripotent stem cells differentiate in vitro into cell types of all three germ layers, exhibiting neuronal, liver, or endothelial characteristics. Our results reveal insight into the molecular events regulating cellular reprogramming and also indicate that pluripotency might be controlled in vivo through binding of a natural ligand(s) to ACA receptor enabling reprogramming through defined pathway(s) and providing a safe and efficient method for generation of pluripotent stem cells which could be a breakthrough in human therapeutics.
