Comparative immunochemical study of lectin‐binding sites and cytoskeletal filaments in static and reactive mesothelium and adenocarcinoma

Abstract

In cytological preparations, reactive mesothelial cells (RMC) in serous effusions are sometimes difficult to distinguish from adenocarcinoma cells (AC). RMC and AC can be distinguished by lectin-binding patterns, but the pattern of binding of lectins to normal mesothelium is not well defined. We investigated the expression of cytoskeletal filaments, cytokeratin (CK) and vimentin (VM), and the cell surface binding pattern of 10 lectins (HPA, SBA, ABA, DSA, PNA, RCA-I, UEA-I, LTA, WGA and ConA) in the serosa of 48 adenocarcinoma specimens. We also investigated the usefulness of six lectins (HPA, SBA, RCA-I, UEA-I, LTA and WGA) in identification of RMC and AC in 16 serous effusions. DSA reactivity was significantly higher (P < 0.05) in static mesothelial cells (SMC) than in RMC. Reactivity for LTA and ConA was significantly lower (P < 0.05) in SMC than in RMC. Anti-CK and anti-VM immunoreactivity was always positive in RMC and almost negative in SMC. In serous effusions, HPA, SBA and UEA-I binding was evident in 100, 88 and 81% of AC, respectively. Little to no binding of HPA, SBA or UEA-I was detected in RMC. Our results suggest that the morphological differences between SMC and RMC are likely to be due to differences in cytoskeletal composition, with accompanying changes in cell-surface lectin-binding patterns. HPA, SBA and UEA-I are likely to be useful markers for identification of RMC and AC in cytology.

Mesothelial cell transplantation in the infarct scar induces neovascularization and improves heart function

“…Our in vitro results showing cytokeratin and lectin BS-1 expression in MCs agree with published data demonstrating that the expression of cytokeratin in cultured MCs was positively affected by cell -cell contact or cell spreading [21]. Lectin binding to normal mesothelium is not well-defined.…”

“…The use of DAPI for tracking implanted cells has recently been criticized [29] since it can be taken up by surrounding cells. The DAPI positivity observed in our sections thus cannot be attributed solely to transplanted MCs, but the colocalization of focal DAPI staining and cytokeratin [21] suggests that some DAPI-labeled cells were indeed transplanted MCs. Our results agree with other studies of transplantation of DAPIlabeled cells [6,7,30] in rat MI models.…”

“…Lectin binding to normal mesothelium is not well-defined. Lectin-binding sites on the cell surface are likely to be involved in cell maturation and transformation [21]. Moreover MCs release large quantities of SDF-1a, much more than other cells such as BM stromal cells, that secrete minimal amounts.…”

“…MCs labeled ex vivo were visualized in the infarct scar of myocardial sections and immunostained for cytokeratin after 30 days, indicating that transplanted MCs were still present in the scar and continued to express cytokeratin, reflecting their reactive state [21]. The use of DAPI for tracking implanted cells has recently been criticized [29] since it can be taken up by surrounding cells.…”

Lectin Histochemistry of Respiratory Mucosa in the Pacific White-Sided Dolphin

“…The ciliary movement and mucus prevent these agents from colonising the surface of the respiratory mucosa. Glycoconjugates play important roles in the attachment of parasites and microbes to the respiratory mucosa [15,16], although there are no data on the glycoconjugate sugar residues in the respiratory mucosa of the Pacific white-sided dolphin. Knowledge of the patterns of glycosylation and the glycoprofiles of cells and the extracellular matrix is important for understanding disease mechanisms.…”