Expression of intermediate filaments, EGF and TGF-α in early human kidney development

Abstract

The spatial and temporal expression patterns of cytokeratins, vimentin, epithelial growth factor (EGF) and transforming growth factor alpha (TGF-alpha), were investigated in the 5-9-week old human mesonephros and metanephros. Vimentin was found in all mesonephric structures, while cytokeratins were seen only in the mesonephric tubules. EGF and TGF-alpha were detected early in all mesonephric structures, and immunoreactivity to both factors decreased in later stages. In the 5-6-week metanephros, vimentin immunoreactivity was found in all structures and later increased in the collecting system and interstitium. In the 5th week, cytokeratins 8 and 19 appeared in the ureteric bud and ampullae, and later showed increasing immunoreactivity in the collecting system and nephrons. The coexpression of intermediate filament proteins in metanephric development is a temporary feature and might be associated with mesenchymal to epithelial transformation of developing nephrons. In adult kidneys, such coexpression is associated with fibrosis or carcinomatous changes. At early stages, immunoreactivity to EGF and TGF-alpha was detected in all metanephric structures and from the 7th week onward, it decreased in differentiating nephrons. EGF and TGF-alpha patterns of appearance indicate their role in induction, proliferation and growth of metanephric structures. Disturbances in that pattern might cause reduction in kidney growth.

Expression of cytokeratin 8, vimentin, syndecan-1 and Ki-67 during human tooth development

“…Inset: details of individual cervical loops on the opposite sides of tooth germ with complete (1) and delayed (2) showing tendency to increase during development in the dental pulp and odontoblasts, but in the preameloblasts as well. Co-expression of CKs and vimentin seems to be a common phenomenon that occurs at brief periods of organogenesis with strictly regulated timeline, and it usually hallmarks epithelial-to-mesenchymal or mesenchymalto-epithelial transformation of developing tissues (Carev et al 2008;Wang et al 2014;Vukojevic et al 2012).…”

Microchimeric Fetal Cells Are Recruited to Maternal Kidney following Injury and Activate Collagen Type I Transcription

“…In another study using the same transgenic mice as bone marrow donors but in a unilateral ureteral ligation model, we have seen partial replacement of injured epithelial cells, with a few epithelial cells expressing the luciferase signal, suggesting they were derived from MSCs . It is therefore possible that FMCs can contribute to tubular cells similar to bone marrow cell contribution and a mesenchymal-to-epithelial transition may take place [Archdeacon and Detwiler, 2008;Carev et al, 2008]. The type of cells that replace tubular cells is controversial, with some studies showing that bone marrow cells participate in this replacement [Poulsom et al, 2001;Lin et al, 2003] while others suggest that bone marrow does not replace significant numbers of tubular cells [Duffield et al, 2005;Lin et al, 2005].…”

Epidermal Growth Factor Receptor Signaling in the Kidney

“…14 EGF and TGF-␣ were prominently expressed during in both early and late nephrogenesis, with strong expression in developing tubules and glomeruli. 12,15 Interestingly, AR was expressed in developing glomeruli only at Ϸ18 weeks of gestation. 16 Figure 3 provides an overview of ErbB family member expression during human nephrogenesis.…”