Surprising absence of heparin in the intestinal mucosa of baby pigs

Abstract

Heparin, a member of a family of molecules called glycosaminoglycans, is biosynthesized in mucosal mast cells. This important anticoagulant polysaccharide is primarily produced by extraction of the mast cell-rich intestinal mucosa of hogs. There is concern about our continued ability to supply sufficient heparin to support the worldwide growth of advanced medical procedures from the static population of adult hogs used as food animals. While the intestinal mucosa of adult pigs is rich in anticoagulant heparin (containing a few hundred milligrams per animal), little is known about how the content of heparin changes with animal age. Using sophisticated mass spectral analysis we discovered that heparin was largely absent from the intestinal mucosa of piglets. Moreover, while the related, nonanticoagulant heparan sulfate glycosaminoglycan was present in significant amounts we found little chondroitin sulfate E also associated with mast cells. Histological evaluation of piglet intestinal mucosa showed a very low mast cell content. Respiratory mast cells have been reported in baby pigs suggesting that there was something unique about the piglets used in the current study. These piglets were raised in the relatively clean environment of a university animal facility and treated with antibiotics over their lifetime resulting in a depleted microbiome that greatly reduced the number of mast cells and heparin content of the intestinal mucosal in these animals. Thus, from the current study it remains unclear whether the lack of intestinal mast cell-derived heparin results from the young age of these animals or their exposure to their depleted microbiome.

Metabolic engineering of Bacillus megaterium for heparosan biosynthesis using Pasteurella multocida heparosan synthase, PmHS2

“…Gel permeation chromatography–high performance liquid chromatography (GPC–HPLC) was used to measure the relative molecular mass properties of heparosan products, with dextran (Additional file 1: Figure S5) being a suitable MW calibrant due to the absence of sulfate groups that can impact molecular shape [41]. The molecular weight ranges determined by GPC–HPLC (Fig.…”

“…GPC-HPLC was used to determine the molecular weight and polydispersity of the heparosan samples [41]. Two analytical columns: TSK G4000 SWXL 7.8 mm × 30 cm, 8 μm in series with TSK G3000SWXL 7.8 mm × 30 cm, 5 μm (Tosoh Corporation, Tokyo, Japan), were protected by a guard column TSK SWXL 6 mm × 4 cm, 7 μm diameter.…”

“…The purified cell pellet and cell culture supernatant heparosan products were also analyzed using polyacrylamide-gel electrophoresis (PAGE) with a 15% total acrylamide resolving gel, as previously described [16, 41, 48]. To visualize the ion front during electrophoresis, a phenol red dye prepared in 50% (w/v) sucrose was added to ~ 10 µg of each sample.…”

Recent advances in biotechnology for heparin and heparan sulfate analysis

“…The UFH and LMWH currently in clinical use are extracted from animal tissues, such as porcine, bovine intestines and bovine lungs [19]. As a result, these products have purity and homogeneity issues and a variable based on animal species, age, sex, health, animal feed types and other environmental factors [20]. More importantly, there is a risk of viral or prion infection, which poses a serious threat to the safety of these drugs.…”

Structural characterization of a clinically described heparin-like substance in plasma causing bleeding

“…HS and HP are polysaccharides having a continuum of sizes with closely related structures and thus in mixtures are difficult to separate and identify. Such structural complexity is further complicated by their different levels of production in organisms of different ages (Yu et al, 2017) and within different tissues and organs (Andrade, et al, 2013;Shi & Zaia, 2009;Warda et al, 2006). Disaccharide analysis represents a useful tool for assessing the structure and concentration of these GAGs (Okamoto, Higashi, Linhardt, & Toida, 2018).…”