heparitin-sulfate and Fatty-Liver

Heparanase is the only confirmed endoglycosidase that cleaves heparan sulfate (HS), a ubiquitous glycosaminoglycan with various essential roles in multiple pathological processes. Thus, the development of heparanase inhibitors has become an attractive strategy for drug discovery, especially in tumour therapy, in which HS mimetics are the most promising compounds. The various biological effects of heparanase also suggest a role for HS mimetics in many non-cancer indications, such as type 1 diabetes. However, the potential benefits of HS mimetics in obesity-related type 2 diabetes have not been elucidated.. In this study, we investigated muparfostat (PI-88), a developed HS mimetic currently enrolled in Phase III clinical trials, in obese mouse models and in vitro cultured murine hepatocytes.. Daily administration of muparfostat for 4 weeks caused hyperlipidaemia and aggravated hepatic steatosis in obese mice models, but not in lean animals. In cultured hepatocytes, muparfostat did not alter lipid accumulation. Acute tests suggested that muparfostat binds to lipoprotein lipase in competition with HS on vascular endothelial cell surfaces, thereby reducing the degradation of circulating triglycerides by lipoprotein lipase and subsequent uptake of fatty acids into vascular endothelial cells and causing hyperlipidaemia. This hyperlipidaemia aggravates hepatic steatosis and causes liver injury in muparfostat-treated obese mice.. The binding activity of HS mimetics to lipoprotein lipase should be investigated as an additional pharmacological effect during heparanase inhibitor drug discovery. This study also provides novel evidence for an increased risk of drug-induced liver injury in obese individuals.

Topics: Animals; Diabetes Mellitus, Type 2; Endothelial Cells; Fatty Liver; Heparitin Sulfate; Lipoprotein Lipase; Mice; Mice, Obese

The extractable and nonextractable collagen and glycosaminoglycuronans (GAG) were estimated and characterized in 32 dried, defatted human livers obtained at necropsy. 10 had normal livers. 22 of the 32 livers were from patients who drank in excess: 5 had fatty livers, 7 had alcholic hepatitis, and 10 had cirrhosis. Livers with alcoholic hepatitis or cirrhosis had significantly increased total and 1 N NaCl-extractable collagen. Only alcoholic hepatitis livers had significantly increased Tris-buffer-extractable GAG, but the amino acid composition of these GAG (proteoglycans) was no different from that of normal livers. The major fraction of these GAG had isoelectric pH (pI)

Topics: Alcoholism; Amino Acids; Chemical and Drug Induced Liver Injury; Chondroitin; Chromatography, Gel; Collagen; Connective Tissue; Dialysis; Fatty Liver; Glucosamine; Glycoproteins; Glycosaminoglycans; Heparitin Sulfate; Hexosamines; Humans; Hyaluronic Acid; Hydroxyproline; Isoelectric Focusing; Liver; Liver Cirrhosis