Heparan sulfate proteoglycan–Transforming growth factor-beta signaling complex (HSPG–TGF-β complex)

The Heparan sulfate proteoglycan–Transforming growth factor-beta (HSPG–TGF-β) signaling complex is a multi-component molecular assembly that regulates the activity of TGF-β through the interaction of heparan sulfate (HS) glycosaminoglycan chains with the ligand and its signaling receptors (NIH/PubMed). HSPGs, such as betaglycan (TGF-β receptor type III), syndecans, and glypicans, act as essential co-receptors that sequester TGF-β in the extracellular matrix and facilitate its presentation to the type I and type II signaling receptors (TβRI and TβRII) (Journal of Biological Chemistry). This complex is fundamental to maintaining cellular homeostasis, as it modulates signaling pathways involved in cell proliferation, differentiation, and the epithelial-mesenchymal transition (EMT) (MDPI/Biomolecules). In pathological conditions, particularly cancer and fibrosis, the deregulation of this complex—often via altered HSPG expression or HS sulfation patterns—promotes tumor invasion, metastasis, and excessive collagen deposition (NIH/PubMed). Therapeutic strategies targeting the complex include the use of heparin mimetics, such as necuparanib and muparfostat, which compete for TGF-β binding, and heparanase inhibitors that prevent the remodeling of the HS scaffold (Cancers). Additionally, antibodies and peptides targeting specific HSPG core proteins are being developed to disrupt the signaling axis in a more selective manner (NIH/PubMed). Understanding the spatial and temporal regulation of this complex is critical for developing effective treatments for TGF-β-driven diseases while avoiding systemic side effects (Nature/Scientific Reports). The complex also plays a role in morphogen gradient formation during development, highlighting its broad biological significance (NIH/PubMed).

Other names

HSPG–TGF-beta complexHeparan sulfate proteoglycan–TGF-beta complexBetaglycan–TGF-beta complexTβRIII–TGF-beta complexHeparan sulfate proteoglycan–Transforming growth factor-beta complex

The complex is targeted by heparin mimetics and heparanase inhibitors that competitively inhibit the binding of TGF-β to heparan sulfate chains or prevent the enzymatic remodeling of the signaling scaffold, thereby disrupting the formation of the active ternary signaling complex and attenuating downstream Smad-dependent and non-Smad signaling pathways.