Cytocheratins Identification in Human Umbilical Cord at Term.

Introduction. Cytokeratins (Cks) are the proteins that constitute intermediate filaments. The pattern of expression of cytokeratins is frequently organ or tissue specific and depends mainly on the type of epithelium, the level of differentiation and the stage of development. With this study we tried to make light on the pattern of expression of a wide range of CKs in human umbilical cord at term. Materials and methods. We investigated the expression of CKs through immunohistochemistry and RT-PCR assay. Results. AE1/AE3 antibody reacts with the basic CKs 1, 2, 3, 4, 5, 6, 7 and 8, and with the acidic CKs 10, 13, 14, 15, 16 and 19. The reactivity for this antibody is localized in the amniotic epithelium. Fibroblasts of the Wharton’s jelly did not react with this antibody. Endothelial cells and some cells of the vessel wall seem to express CKs at low levels. Reactivity for 34βE12 antibody (that recognizes CKs 1, 5, 10 and 14) is localized in the cells of the umbilical epithelium, while all the other regions of the umbilical cord did not react with the antibody. The immunoreactivity for MNF116 antibody (that recognizes CKs 5, 6, 8, 17 and 19) is restricted to the cells of the umbilical epithelium while all the other cells of the umbilical cord seems not to express these types of Cks. RT-PCR analysis revealed gene expression for CKs 5, 6, 8, 10, 14 and at a lower level also cytokeratins 1 and 17. Conclusions. We identified the expression of several types of CKs in human umbilical cord at term both at proteic and RNA level. References. 1) Bea F, Bär H, Watson L, Blessing E, Kübler W, Kreuzer J, Jahn L.Cardiac alpha-actin in smooth muscle cells: detection in umbilical cord vessels and in atherosclerotic lesions.Basic Res Cardiol. 2000 Apr;95(2):106-13. 2) Livasy CA, Karaca G, Nanda R, Tretiakova MS, Olopade OI, Moore DT, Perou CM.P henotypic evaluation of the basal-like subtype of invasive breast carcinoma. Mod Pathol. 2006 Feb;19(2):264-71