Heparin Inhibits Activation of Latent Transforming Growth Factor-β₁

Abstract

Aim: Besides acting as an anticoagulant, heparin has antifibrotic effects. Transforming growth factor-β₁ (TGF-β₁) is secreted from cells as latent TGF-β₁ (LTGF-β₁). LTGF-β₁ consists of TGF-β₁ and latency-associated peptide (LAP). To be biologically active, TGF-β₁ has to be released from LAP. Heparin binds to LAP as well as TGF-β₁. This study was performed to explore the biological effect of the interaction of heparin with LTGF-β₁. Materials and Methods: TGF-β₁ was measured by ELISA. Furin-like proprotein convertase activity was assayed using the fluorogenic substrate, Pyr-Arg-Thr-Lys-Arg-AMC. Results: Heparin did not interfere with the receptor binding of TGF-β₁, but inhibited furin-like proprotein convertase-mediated activation of platelet LTGF-β₁. This was not by inhibition of the enzyme because heparin did not inhibit the activity of furin-like proprotein convertase. In addition, heparin inhibited acid activations of recombinant small LTGF-β₁, platelet LTGF-β₁ and LTGF-β₁s secreted in the supernatant of cultured cells. Low-molecular-weight heparins, including dalteparin, enoxaparin and nadroparin, also had inhibitory effects on furin-like proprotein convertase-mediated or acid activation of platelet LTGF-β₁. Conclusion: The findings suggest that heparin renders LTGF-β₁ resistant to activation, possibly by binding simultaneously to TGF-β₁ and LAP. Inhibition of LTGF-β₁ activation by heparin may in part account for its antifibrotic effects.

Structural characteristics of Heparan sulfate required for the binding with the virus processing Enzyme Furin

“…5 , heparin significantly inhibits the Furin enzymatic activity by pre-mixing heparin with either Furin or Furin substrate and the reaction is very quick. The results is consistent with the results that heparin inhibits the activation of latent TGFß-1 by inhibiting the processing of latent TGFß-1 by Furin [ 19 ]. But heparin enhances the Furin cleavage of HIV-1 gp160 peptides in different length [ 10 ], the difference could be due to the reaction condition and enzymatic activity determination method is different from what we used.…”

Aortic Dimensions, Biophysical Properties, and Plasma Biomarkers in Children and Adults with Marfan or Loeys-Dietz Syndrome

“…10,11 The ELISA method and the TGF-b1 assay we used was the same Quantikine immunoassay as those studies. [32][33][34] To confirm this result, and in keeping with the suggestion that free TGF-b1 may be a more relevant marker, 35 we analyzed free and total TGF-b1 levels using the Quanterix immunoassay. Free TGF-b1 was not increased and total TGF-b1 levels were very similar using both assays.…”

Recombinant production, purification, crystallization, and structure analysis of human transforming growth factor β2 in a new conformation

“…Mature human and mouse TGFβ2 GFs were obtained in high yields (~8–10 mg/liter of cell culture) from Escherichia coli systems 34 . However, these proteins lacked glycosylated LAP, which has (glycan-mediated) functions beyond latency maintenance 35–38 . In addition, these systems produced insoluble protein in inclusion bodies that had to be refolded 34,39 .…”