Galectin-1 and galectin-3 in fetal development of bovine respiratory and digestive tracts

Abstract

Histochemical monitoring of developmental processes is presently centered on protein-protein interactions. However, oligosaccharides have the potential to store and transmit biological information. Carbohydrate chains of cellular glycoconjugates present determinants for binding of endogenous lectins. This interaction can be relevant for developmental processes. In fact, beta-galactosides and their derivatives serve as ligands for members of the lectin family of galectins. Since it is unclear to what extent functions of different galectins differ or overlap, hereby introducing redundancy into this system, monitoring of galectin presence during tissue maturation should include more than one type of galectin (galectin fingerprinting). Here, we focus on the two most frequently described ones, namely the homodimeric prototype galectin-1 and the chimera-type galectin-3, the latter one so far not characterized from bovine tissue. In the first step, we have detected its presence biochemically in addition to the abundant galectin-1 in bovine respiratory and digestive tracts during development. Evidently, diversification of the primitive foregut will not lead to an alteration of this property. Immunohistochemistry revealed clear differences in the galectins' localization profiles. Galectin-1 expression is strong in mesenchymal cells, especially smooth muscle cells, while epithelial lining harbors galectin-3. A gradual increase in staining intensity with development is especially observed in the case of galectin-3. Notably, this change is accompanied by a shift from primarily nuclear localization to the cytoplasm, an alteration not seen for galectin-1. However, nuclear presence of galectin-1 is encountered. Thus, the delineation of differences in expression of galectin-1 and -3 with respect to cell types and in the developmental course of subcellular localization argues in favor of mediation of nonoverlapping functions by these two homologous, endogenous lectins.

Increased galectin-3 expression and intra-epithelial neutrophils in small airways in severe COPD

“…Galectins are secreted lectins that participate in the regulation of neutrophil recruitment and cell apoptosis/proliferation, notably during lung development and inflammatory responses [10][11][12][13][14]. The present study showed for the first time that epithelial expression of galectin-3 is increased in the small airways of severe COPD patients.…”

“…Endogenous peroxidase activity was inhibited by incubation in 0.03% v/v H 2 O 2 and sections were blocked by normal horse serum and avidin/biotin blocking kit (Dako, Glostrup, Denmark). Sections were then treated for 30 min with 1:100 rabbit polyclonal anti-human galectin-1 or -3 antibodies, which had been rigorously tested for specificity by ELISA and Western blotting [12,19,20]. Control sections were incubated with normal rabbit serum (1:100).…”

“…Galectins are galactose-binding proteins that are involved in lung physiology [9][10][11][12]. Galectin-3 can enhance the proliferation of respiratory epithelial cells by limiting adhesion to the basement membrane through competition with integrin receptors for the binding of laminin in the extracellular matrix [13].…”

Search for additional influenza virus to cell interactions

“…Thus, our data on galactosidebinding ability of MDCK cells is in agreement with data on infection of desialylated MDCK cells [1], however this phenomenon seems to be rather exceptional, MDCK-specific, than general. It is even challenging to understand, whether galectin/galactoside interaction may play a role during the infection process, taking into account the presence of galectins in bronchial and tracheal epithelium [42,43]. It should be also noted that several galectins demonstrate elevated binding to sulfated galactosides, and, at the same time, as mentioned above, influenza virus envelop, especially HA is extensively sulfated.…”

Persubstituted Cyclodextrin-Based Glycoclusters as Inhibitors of Protein−Carbohydrate Recognition Using Purified Plant and Mammalian Lectins and Wild-Type and Lectin-Gene-Transfected Tumor Cells as Targets

“…To calculate the glycoclusters' efficiency, we set an internal standard by running assays with galactose and lactose as reference substances in parallel. Tables 1 and 2 present the data for the five receptor types and the four (neo)glycoproteins as IC 50 values. The measurements revealed that the glycoclusters had pronounced activities, the immunoglobulin G fraction and the plant lectin being markedly responsive (Tables 1a,b).…”