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

Lectin histochemistry of respiratory mucosa in the Pacific white-sided dolphin

Sugars in the glycocalyx play an important role in the attachment of infectious agents to the respiratory mucosa. We examined the histochemistry of 23 lectins to survey the sugar expression in the glycocalyx of the respiratory mucosa of the Pacific white-sided dolphin, Lagenorhynchus obliquidens. The ciliated and basal cells were positive for all of the lectins studied. SBA, WFA, GSL-II, STL, S-WGA, and PNA staining in the cytoplasm showed different intensities between basal cells and ciliated cells. These results suggest that multiple terminal glycosylation occurs on ciliated and basal cells, such as GalNAc, GlcNAc, NeuNAc, galactose, glucose/mannose, oligosaccharide, and fucose, and that sugar residue expression changes during cell differentiation. The Pacific white-sided dolphin respiratory mucosa might express multiple sugar residues in the glycocalyx, to prevent the attachment and colonisation of infectious agents.

Significance of a galactose specific plant lectin for the differential diagnosis of adenocarcinoma cells in effusion

Background:

Distinguishing adenocarcinoma cells from reactively proliferated mesothelial cells and macrophages is one of the greatest challenges in the cytodiagnosis of effusions. Aberrant glycosylation of cell surface glycoconjugates is emblematic to malignancy, and lectins being an important class of probes to demonstrate these aberrations, lectin cytochemistry is of great interest to differentiate adenocarcinoma cells from reactive mesothelial cells.

Aim:

The present study analyzed the potential of a plant lectin to distinguish malignant cells from reactive mesothelial cells and macrophages.

Materials and Methods:

Snake gourd lectin (SGL) was isolated, purified and conjugated to horse radish peroxidase (HRP) and incubated with the cells of benign (46) as well as malignant (39) effusions using the standard immunocytochemical method with diaminobenzidine as the chromogen. The lectin-bound areas were quantitatively assessed as mild, moderate and intense binding.

Statistical Analysis:

The mean score for benign and malignant effusions were statistically analyzed. Student's ‘t’-test was performed to assess the significance.

Results:

The lectin HRP complex bind to the cytoplasm of benign and malignant cells as well as macrophages. A significantly higher score for intense binding (P = 0.001) was found to differentiate malignant cells from reactive mesothelial cells. Macrophages showed intense irregular binding.

Conclusions:

SGL binding assay can play a role in the differential diagnosis of metastatic adenocarcinoma in effusions.

Mesothelial cell transplantation in myocardial infarction

Mesothelial cells (MCs) are accessible in human patients by excision and digestion of epiploon or from peritoneal fluid or lavage. MCs are easy to culture to obtain large quantities in vitro and they can be genetically modified with interesting therapeutic genes. The important potential of MCs in tissue engineering has been shown during epiplooplasty to different organs and also in creating artificial blood conduits. MC of epicardium is probably the precursor of coronary arteries during embryogenesis. MCs secrete a broad spectrum of angiogenic cytokines, growth factors and extracellular matrix, which could be useful for repairing damaged tissues. MCs are transitional mesodermal-derived cells and considered as progenitor stem cell, have similar morphological and functional properties with endothelial cells and conserve properties of transdifferentiation. MC therapy in myocardial infarction induced neoangiogenesis in infarcted scar and preserved heart function. In conclusion, a potential therapeutic strategy would be to implant or re-implant genetically modified MCs in post-infarction injury to enhance tissue repair and healing. Imparting therapeutic target genes such as angiogenic genes would also be useful for inducing neovascularization.