Immunohistochemical identification of cytokeratins in the rat submandibular salivary glands during ontogenesis

Abstract

Cytokeratins (CK) are a group of proteins comprised of at least 20 different skeletal polypeptides specific for simple and complex epithelia of almost all tissues. Until recently only a few antibodies for cytoskeletal proteins were available and thus it was very difficult to visualize all the components of postnatal cytodifferentiation of salivary glands. Therefore, morphologic and immunophenotypic features of the CK polypeptides, have been analized within the rat submandibular salivary glands (SSG) during postnatal development. SSG were obtained from 1, 30 and 60 days old, male, AO rats. Streptavidin-biotin immunoperoxidase method was used for immunohistochemistry. Cryostat sections were fixed in acetone and incubated with monoclonal antibodies (mAbs) which specifically react with CK polypeptides (CK7, CK8, CK18, CK kidney, K8.12, K8.13) and rat epithelium (PT13D11). Immunohistochemical analysis of the rat SSG showed phenotypic heterogeneity of particular components of this gland during postnatal development. Regarding CK profiles it was shown that epithelial cells of the acini expressed CK18, whereas epithelial cells of the duct expressed K8.12 and K8.13 mAbs. Epithelial cells of the acini were not stained by K8.12 and PT13D11 mAbs. Intercalated ducts were strongly CK kidney+ and PT13D11+. Myoepithelial cells of the acini were stained by K8.13 mAbs, whereas these cells were not stained by mAbs specific for simple epithelia. This immunohistological study showed that the heterogeneity expression of CK polypeptides might also be useful to further understand the origin of epithelial SSG cells, as well as their development and function.

Citokeratini (CK) su grupa složenih proteina koji se sastoje od najmanje 20 različitih polipeptida citoskeleta, specifični za običan i složeni epitel skoro svih tkiva. Do skoro je bilo dostupno samo nekoliko antitela specifičnih za proteine citoskeleta i zbog toga je bila otežana vizualizacija komponenti postnatalne citodiferencijacije pljuvačnih žlezda. U ovoj studiji su, pomoću panela monoklonskih antitela (mAt), analizirane morfološke i imunofenotipske osobine CK polipeptida, u submandibularnoj pljuvač noj žlezdi (SPŽ) pacova tokom ontogeneze. Submandiblarne pljuvačne žlezde uzimane su od soja AO pacova, muškog pola, starosti 1, 30 i 60 dana. U ovom radu korišćena je imunohistohemijska metoda streptavidin-biotin peroksidaznog bojenja. Tkivni preseci fiksirani su u acetonu i inkubirani sa mAt specifičnim za CK polipeptide (CK7, CK 8, CK 18, CK bubrega, K8.12, K8.13) i epitel pacova (PT13D11). U ovoj imunohistohemijskoj analizi, ekspresija anti -CK antitela na SPŽ pacova, pokazuje fenotipsku heterogenost određenih komponenti ove žlezde tokom postnatalnog perioda. Epitelne ćelije acinusa su CK18+, dok epitelne ćelije kanalića imaju izražene CK definisane sa K8.12 i K8.13 mAt. Epitelne ćelije acinusa nisu bile obojene sa K8.12 i PT13D11 mAt. Umetnuti kanali su bili izrazito CK bubrega+ i PT13D11+. Mioepitelne ćelije acinusa su bile obojene sa K8.13 i PT13D11 mAt, dok su ove ćelije imale negativnu reakciju sa mAt specifičnim za obični epitel. Ova imunohistohemijska studija pokazuje heterogenost u ekspresiji CK polipeptida i može poslužiti za razumevanje porekla, razvoja i funkcije epitelnih ćelija SPŽ pacova.