Background: Urothelium is a multilayer epithelium covering the inner surface of the urinary bladder that acts as a blood-urine barrier and is involved in maintaining the wellbeing of the whole organism. Glycans serve in the maturation and differentiation of cells and thus play a key role in the morphology and function of the multilayered epithelium. The aim of the present study was to examine the glycoprotein pattern of the horse urinary bladder urothelium by lectin histochemistry.Methods: The study involved urinary bladders from four horse stallions. Tissue sections were stained with a panel of eleven lectins, in combination with saponification and sialidase digestion (Ks).Results: Basal cells displayed high-mannose N-glycans (Con A), alpha 2,6-linked sialic acid (SNA), and O-linked sialoglycans with sialic acids linked to Gal beta l,3GalNAc (T antigen) (KsPNA) and terminal N-acet-ylgalactosamine (Tn antigen) (KsSBA). The young intermediate cells expressed terminal N-acet-ylglucosamine (GlcNAc) (GSA II), galactose (GSA I-B4), T-and Tn antigens (PNA, SBA). The mature intermediate cells showed additional high-mannose N-glycans, O-linked sialoglycans (sialyl-T antigen, sialyl-Tn antigen), alpha 2,6-and alpha 2,3-linked sialic acid (MAL II), alpha 1,2-linked fucose (UEA I), and GlcNAc (KsWGA). The latter residue marked the boundary with the overlying surface layer. Few Con A positive intermediate cells were seen to cross the entire urothelium thickness. The surface cells showed additional glycans such as T antigen and sialic acids linked to GalNAc binding DBA (KsDBA). Few surface cells contained alpha 1,3-linked fucose (LTA), whereas some other cells displayed intraluminal secretion of mucin-type glycans terminating with GalNAc alpha 1,3(LFuc alpha 1,2)Gal beta 1,3/4GlcNAc beta 1 (DBA). The luminal surface expressed the most complex glycan pattern in the urothelium because only alpha 1,3-linked fucose lacked among the demonstrated glycans. Conclusions: This study showed that the glycan pattern becomes more complex from the basal to surface layer of the urothelium and that surface cells could modify the composition of urine via the secretion of glycoproteins.(c) 2022 Elsevier GmbH. All rights reserved.
Differential expression of glycans in the urothelial layers of horse urinary bladder
Desantis, Salvatore
;Santamaria, Nicoletta;Zizza, Sara;Accogli, Gianluca;Mastrodonato, Maria;Scillitani, Giovanni;Mentino, Donatella
2022-01-01
Abstract
Background: Urothelium is a multilayer epithelium covering the inner surface of the urinary bladder that acts as a blood-urine barrier and is involved in maintaining the wellbeing of the whole organism. Glycans serve in the maturation and differentiation of cells and thus play a key role in the morphology and function of the multilayered epithelium. The aim of the present study was to examine the glycoprotein pattern of the horse urinary bladder urothelium by lectin histochemistry.Methods: The study involved urinary bladders from four horse stallions. Tissue sections were stained with a panel of eleven lectins, in combination with saponification and sialidase digestion (Ks).Results: Basal cells displayed high-mannose N-glycans (Con A), alpha 2,6-linked sialic acid (SNA), and O-linked sialoglycans with sialic acids linked to Gal beta l,3GalNAc (T antigen) (KsPNA) and terminal N-acet-ylgalactosamine (Tn antigen) (KsSBA). The young intermediate cells expressed terminal N-acet-ylglucosamine (GlcNAc) (GSA II), galactose (GSA I-B4), T-and Tn antigens (PNA, SBA). The mature intermediate cells showed additional high-mannose N-glycans, O-linked sialoglycans (sialyl-T antigen, sialyl-Tn antigen), alpha 2,6-and alpha 2,3-linked sialic acid (MAL II), alpha 1,2-linked fucose (UEA I), and GlcNAc (KsWGA). The latter residue marked the boundary with the overlying surface layer. Few Con A positive intermediate cells were seen to cross the entire urothelium thickness. The surface cells showed additional glycans such as T antigen and sialic acids linked to GalNAc binding DBA (KsDBA). Few surface cells contained alpha 1,3-linked fucose (LTA), whereas some other cells displayed intraluminal secretion of mucin-type glycans terminating with GalNAc alpha 1,3(LFuc alpha 1,2)Gal beta 1,3/4GlcNAc beta 1 (DBA). The luminal surface expressed the most complex glycan pattern in the urothelium because only alpha 1,3-linked fucose lacked among the demonstrated glycans. Conclusions: This study showed that the glycan pattern becomes more complex from the basal to surface layer of the urothelium and that surface cells could modify the composition of urine via the secretion of glycoproteins.(c) 2022 Elsevier GmbH. All rights reserved.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
