Bioactivity screening of partially desulfated low-molecular-weight heparins: A structure/activity relationship study

Abstract

A series of size-defined low-molecular-weight heparins were generated by regioselective chemical modifications and profiled for their in vitro and in vivo activities. The compounds displayed reduced anti-coagulant activity, demonstrated varying affinities toward angiogenic growth factors (fibroblast growth factor-2, vascular endothelial growth factor and stromal cell-derived factor-1α), inhibited the P-selectin/P-selectin glycoprotein ligand-1 interaction and, notably, exhibited anti-tumor efficacy in a murine melanoma experimental metastasis model. Our results demonstrate that modulating specific sequences, especially the N-domains (-NS or -NH(2) or -NHCOCH(3)) in these polysaccharide sequences, has a major impact on the participation in a diverse range of biological activities. These results also suggest that the 6-O-sulfates, but not the 2-O-sulfates, critically affect the binding of a desulfated derivative to certain angiogenic proteins as well as its ability to inhibit P-selectin-mediated B16F10 melanoma metastases. Furthermore, N-desulfation followed by N-acetylation regenerates the affinity/inhibition properties to different extents in all the compounds tested in the in vitro assays. This systematic study lays a conceptual foundation for detailed structure function elucidation and will facilitate the rational design of targeted heparan sulfate proteoglycan-based anti-metastatic therapeutic candidates.

Pharmacology of Heparin and Related Drugs

“…A systematic survey of binding of FGF-2, VEGF, and SDF-1 with carefully characterized preparations of partially desulfated LMWH fractions using surface plasmon resonance (SPR) has been reported (Roy et al, 2011). Although all the compounds tested remained heterogeneous, it was possible to show that 6-O-sulfation had more of an effect on binding to VEGF and SDF-1 and 2-O-sulfation on FGF-2.…”

Heparin-based hydrogels with tunable sulfation & degradation for anti-inflammatory small molecule delivery

“…22 Hep −N hydrogels were chosen for this experiment as they showed the most linear, long-term release of CV and, due to their diminished anti-coagulation properties compared to fully sulfated heparin, may be a safer alternative for in vivo theparies. 41,42 Furthermore, only the supernatant from the last time point prior to hydrogel degradation was used. After 6.5 hours incubation, ang-2 gene expression was significantly more inhibited in the 20 μM soluble CV and Hep −N hydrogel supernatant groups, which also contained ~ 20 μM CV, than in the no treatment control (Figure 5).…”

Old and new applications of non-anticoagulant heparin

“…N-desulfated heparin, named "heparamine", showed reduced anticoagulant activity, experimental beneficial effects in preventing hepatic and renal damage by ischemia and reperfusion, as well as in inhibiting angiogenesis and experimental metastatic gastric cancer [88]. Structural modifications and structural activity relationship studies were mainly targeted towards inflammation [5], angiogenesis, cardiovascular and pulmo nary diseases [11], metastasis [89] as well as Alzheimer's disease [90] and cerebral malaria [91]. The last two reports demonstrated the activity of N-desulfated-Nacetylated heparin (named heparide) and LMWHs.…”

“…The last two reports demonstrated the activity of N-desulfated-Nacetylated heparin (named heparide) and LMWHs. These and some N-acyl analogues showed beneficial effects in inflammation myocardial ischemic and reperfusion injury [5], inhibitory activity of angiogenesis and metastasis [89] in a broad spectrum of experimental models. An oversulfated LMWH preparation was found beneficial in an iron restricted anaemia model through inhibition of the peptide hormone Hepcidin [68].…”

“…An oversulfated LMWH preparation was found beneficial in an iron restricted anaemia model through inhibition of the peptide hormone Hepcidin [68]. Various types of derivatives, chemical processes, some biological interactions and activities are reported in dedicated reviews [87,89,92,93]. While the early structurally defined heparin binding to AT and thrombin supported the search of new anticoagulants and antithrombotics, only a few of the heparin interactions with the multitude of proteins involved, for example in inflammation [5], angiogenesis, metastasis and cancer [94] as well as atherosclerosis (LDL) [95] have been fully investigated to date.…”