Targeting Collagen Secretion as a Potential Therapeutic Strategy to Modulate Fibrosis

ABSTRACT: Fibrotic diseases are driven by the excessive accumulation of extracellular matrix (ECM), particularly collagens, leading to progressive tissue stiffness and organ dysfunction. While many factors contribute to fibrosis—including cytokine signaling, integrin-mediated mechanotransduction, and altered ECM degradation—the synthesis and secretion of collagen remain central bottlenecks. Collagen biosynthesis is a complex process involving extensive post-translational modification and intracellular trafficking. The export of procollagen from the endoplasmic reticulum (ER) requires Transport and Golgi Organisation 1 (TANGO1), a transmembrane organizer of ER exit sites that coordinates cargo selection, membrane remodeling, and connectivity between the ER and the ER-Golgi-Intermediate-Comaprtment (ERGIC). By assembling into ring-like structures at ER exit sites, TANGO1 builds a secretory route for bulky cargoes that bypasses conventional vesicle constraints. Loss of TANGO1 disrupts collagen secretion and causes developmental defects across various species. In fibrotic tissues, TANGO1 expression is upregulated, linking secretory machinery to pathological matrix deposition. Recent work has identified specific interfaces within the complex of TANGO1 with its vertebrate paralogue Cutaneous T-cell lymphoma-associated antigen 5 (cTAGE5) as targets for cell-permeant peptide inhibitors. Inhibitors that selectively and specifically block TANGO1 complex formation reduce collagen secretion in fibroblasts and scar formation in vivo, offering a new strategy to modulate fibrotic processes.