heparitin-sulfate and Hypertrophy

Exostosin-1 (EXT1) and EXT2 are the major genetic etiologies of multiple hereditary exostoses and are essential for heparan sulfate (HS) biosynthesis. Previous studies investigating HS in several mouse models of multiple hereditary exostoses have reported that aberrant bone morphogenetic protein (BMP) signaling promotes osteochondroma formation in Ext1-deficient mice. This study examined the mechanism underlying the effects of HS deficiency on BMP/Smad signaling in articular cartilage in a cartilage-specific Ext. We generated mice with a conditional Ext1 knockout in cartilage tissue (Ext1-cKO mice) using Prg4-Cre transgenic mice. Structural cartilage alterations were histologically evaluated and phospho-Smad1/5/9 (pSmad1/5/9) expression in mouse chondrocytes was analyzed. The effect of pharmacological intervention of BMP signaling using a specific inhibitor was assessed in the articular cartilage of Ext1-cKO mice.. Hypertrophic chondrocytes were significantly more abundant (P = 0.021) and cartilage thickness was greater in Ext1-cKO mice at 3 months postnatal than in control littermates (P = 0.036 for femur; and P < 0.001 for tibia). However, osteoarthritis did not spontaneously occur before the 1-year follow-up. matrix metalloproteinase (MMP)-13 and adamalysin-like metalloproteinases with thrombospondin motifs(ADAMTS)-5 were upregulated in hypertrophic chondrocytes of transgenic mice. Immunostaining and western blotting revealed that pSmad1/5/9-positive chondrocytes were more abundant in the articular cartilage of Ext1-cKO mice than in control littermates. Furthermore, the BMP inhibitor significantly decreased the number of hypertrophic chondrocytes in Ext1-cKO mice (P = 0.007).. HS deficiency in articular chondrocytes causes chondrocyte hypertrophy, wherein upregulated BMP/Smad signaling partially contributes to this phenotype. HS might play an important role in maintaining the cartilaginous matrix by regulating BMP signaling.

Topics: ADAMTS5 Protein; Animals; Bone Morphogenetic Proteins; Cartilage, Articular; Chondrocytes; Disease Models, Animal; Heparitin Sulfate; Hypertrophy; Matrix Metalloproteinase 13; Mice; Mice, Knockout; Mice, Transgenic; N-Acetylglucosaminyltransferases; Osteoarthritis, Knee; Pyrazoles; Pyrimidines; Smad1 Protein; Smad5 Protein; Smad8 Protein

To report unusual gynaecological features associated with Sanfilippo syndrome, a rare progressive multisystem storage disorder.. A 10-year-old adolescent girl with Sanfilippo syndrome type B, presented to the Center for Adolescent Medicine accompanied by her mother. Maternal anxiety was related to a palpable mass over the adolescent's external genitalia that had been causing her discomfort and exacerbation of her behavioural problems when wearing trousers. The mass was also a site of blood accumulation during her menstruation causing hygiene issues. Gynaecological examination revealed hypertrophy and thickening of the adolescent's hymen, labia minora and the posterior fourchette, that protruded like a mass in her perineum. These findings were attributed to the accumulation of heparan sulphate in the connective tissue of her external genitalia and perineal area. Reassurance as well as counselling about hygiene and avoidance of tight clothes were provided to the mother.. Girls with mucopolysaccharidoses need monitoring for evolving gynaecological problems in order to improve their quality of life.

Topics: Child; Female; Heparitin Sulfate; Humans; Hypertrophy; Mucopolysaccharidosis III; Perineum; Vagina; Vulva

Heparan sulfate (HS) is one of the components of extracellular matrix and a potent anti-growth factor in various cells. Heparin has a similar structure to HS and is demonstrated to inhibit myocardial cell hypertrophy. We examined the intracellular signal mechanisms linking to the inhibitory effects of heparin and HS on endothelin-1 (ET-1)-induced hypertrophy in cultured rat neonatal myocardial cells (MCs). Heparin inhibited ET-1-induced c-fos mRNA expression. Heparin and HS inhibited ET-1-induced activation of c-fos promoter/enhancer in MCs. Although heparin and HS inhibited ET-1-induced activation of the wild-type c-fos serum response element (SRE), the activation of a mutated c-fos SRE that contains an intact binding site for the serum response factor (SRF) but lacks the ternary complex factor (TCF) binding site, was not inhibited. In addition, heparin and HS inhibited the activation of TPA response element (TRE). However, heparin did not inhibit the activation of cyclic AMP response element (CRE). Furthermore, heparin and HS inhibited ET-1-induced activation of extracellular signal-regulated kinase (ERK) and phosphorylation of Elk-1, which is one of the TCFs. These results indicate that heparin and HS inhibited ET-1-induced ERK activation, resulting in suppression of Elk-1 phosphorylation, and lead to inhibition of c-fos gene expression through SRF-independent manner. Moreover, heparin and HS inhibited ET-1-induced [3H] leucine incorporation. These results suggest that heparin and HS inhibit ET-1 induced myocardial cell hypertrophy through the inhibition of gene expression and protein synthesis.

Topics: Amino Acids; Animals; Cyclic AMP Response Element-Binding Protein; DNA-Binding Proteins; Endothelin-1; Enhancer Elements, Genetic; Enzyme Activation; Enzyme Inhibitors; ets-Domain Protein Elk-1; Gene Expression; Heparin; Heparitin Sulfate; Hypertrophy; Mitogen-Activated Protein Kinases; Myocardium; Phosphorylation; Promoter Regions, Genetic; Proto-Oncogene Proteins; Proto-Oncogene Proteins c-fos; Rats; Rats, Sprague-Dawley; Response Elements; RNA, Messenger; Transcription Factors

Heparan sulfate, one of the primary components of extracellular matrix, is a potent antigrowth factor in certain types of cells. To elucidate a possible role of endogenous heparin-like molecules in regulating cardiomyocyte hypertrophy, we investigated the effects of heparin and heparan sulfate on angiotensin (Ang) II-induced hypertrophy in cultured neonatal rat cardiomyocytes.. Competitive [3H]heparin binding assay showed that cardiomyocytes had specific binding sites for heparin. In situ [3H]heparin binding assay demonstrated that heparin, which rapidly bound to the cardiomyocyte surface, was subsequently accumulated around the nuclei, suggesting that heparin might work in the nucleus. Cotreatment with heparin (20 micrograms/mL) completely inhibited increased cell surface area by Ang II (10(-6) mol/L). Increased [3H]leucine incorporation by Ang II was reduced by heparin dose-dependently. The inhibitory effect of heparin on Ang II-induced cardiomyocyte hypertrophy also was confirmed by Northern blot analysis: heparin dose-dependently inhibited skeletal alpha-actin and atrial natriuretic peptide gene expression, genetic markers for cardiomyocyte hypertrophy. Heparan sulfate showed similar inhibitory effects on cell surface area, [3H]leucine incorporation, and skeletal alpha-actin gene expression. Treatment with heparinase I or III, which specifically digests the disaccharide chains of endogenous heparin-like molecules, upregulated protein synthesis and skeletal alpha-actin and atrial natriuretic peptide gene expression in cardiomyocytes.. Our findings in this study strongly suggest that heparin and heparan sulfate are potent inhibitors of cardiomyocyte hypertrophy and that endogenous heparin-like substances negatively regulate cardiomyocyte hypertrophy.

Topics: Angiotensin II; Animals; Cardiomegaly; Cells, Cultured; Heart; Heparin; Heparin Lyase; Heparitin Sulfate; Humans; Hypertrophy; Leucine; Myocardium; Polysaccharide-Lyases; Rats; Recombinant Proteins