Glycosaminoglycans in porcine lung: an ultrastructural study using Cupromeronic Blue

Abstract

Glycosaminoglycans (GAGs) are essential components of the extracellular matrix contributing to the mechanical properties of connective tissues as well as to cell recognition and growth regulation. The ultrastructural localization of GAGs in porcine lung was studied by means of the dye Cupromeronic Blue in the presence of 0.3 M MgCl2 according to Scott's critical electrolyte concentration technique. GAGs were observed in locations described as follows. Pleura: Dermatan sulphate (DS) and chondroitin sulphate (CS) attached in the region of the d-band of collagen fibrils, interconnecting the fibrils; heparan sulphate (HS) at the surface of elastic fibers and in the basement membrane of the mesothelium and blood vessels. Bronchial cartilage: Abundant amounts of GAGs were observed in three zones: pericellular, in the intercellular matrix and at the perichondrial collagen. By enzyme digestion a superficial cartilage layer with predominantly CS could be distinguished from a deep zone with CS and keratan sulphate. The structure of the large aggregating cartilage proteoglycan was confirmed in situ. Airway epithelium: HS at the whole surface of cilia and microvilli and in the basement membrane of the epithelial cells. Alveolar wall: CS/DS at collagen fibrils, HS at the surface of elastic fibers and in the basement membranes of epithelium and endothelium.

P159 from Mycoplasma hyopneumoniae Binds Porcine Cilia and Heparin and Is Cleaved in a Manner Akin to Ectodomain Shedding

“…34 We also mapped the precise cleavage event in P110 that generates P76 and P35 within the sequence 738 L-K-V↓G-A-A 743 by identifying the semitryptic fragment 741 GAAAANSIFSSE- We previously identified a cleavage site in Mhp385, a heparin-binding paralog of P97 that showed sequence similarity with 738 L-K-V↓G-A-A 743 . This cleavage event occurred at the sequence L-N-V↓A-V-S, and like 738 L-K-V↓G-A-A 743 , it did not reside within a region of protein disorder.…”

The Structure of the Gular Pouch of Mature Males of the Lamprey Geotria australis

“…In mammals, they have been shown to be part of a proteoglycan that is attached to collagen and termed decorin (Fischer 1993). In the connective tissue of the pig lung, this glycosaminoglycan is dermatan sulphate (Erlinger 1995), whose function is apparently to form cross bridges between collagen fibrils (Scott 1988(Scott , 1992. In those areas of the extracellular matrix, where collagen fibrils are absent, the cupromeronic blue precipitates, that are present at 0.06 M MgCI2, but not 0.3 M MgCI2, represent hyaluronic acid, a large nonsulphated molecule that binds water and is thus responsible for creating diffusion spaces for metabolites (Scott 1992).…”

Influence of fetuin and hyaluronan on the post-thaw quality and fertilizing ability of Holstein bull semen

“…Hyaluronan (which is an essential component of the extracellular matrix), a non-sulfated glycosaminoglycan and an additive with antioxidant properties, contributes to cell recognition, cellular adhesion and growth regulation. It is involved in important physiological functions such as the post-thaw motility, capacitation ability and antioxidant capacity of the sperm cell [19,26,31]. Fetuin is both a major glycoprotein component of foetal calf serum (FCS) and a protease inhibitor, and has been shown to inhibit zona pellucida hardening during the in vitro maturation of mouse [50] and equine oocytes [24].…”