latanoprost

Latanoprostene Bunod (LBN) is a topical ophthalmic therapeutic for the reduction of intraocular pressure (IOP) in patients with open-angle glaucoma or ocular hypertension. There is no cure for glaucoma and therapeutic management is predominantly focused on minimizing disease progression and clinical sequelae via the reduction and maintenance of appropriate target IOPs. Latanoprostene Bunod is thought to lower intraocular pressure via a dual mechanism of action since the medication is metabolized into two relevant moieties upon administration: latanoprost acid, and butanediol mononitrate. As a prostaglandin F2-alpha analog, the latanoprost acid moiety operates as a selective PGF2-alpha (FP) receptor agonist. Since FP receptors occur in the ciliary muscle, ciliary epithelium, and sclera the latanoprost acid moiety primarily acts in the uveoscleral pathway where it increases the expression of matrix metalloproteinases (MMPs) like MMP-1, -3, and -9 which promote the degradation of collagen types I, III, and IV in the longitudinal bundles of the ciliary muscle and surrounding sclera. The resultant extracellular matrix remodeling of the ciliary muscle consequently produces reduced outflow resistance via increased permeability and increased aqueous humor outflow through the uveoscleral route. Conversely, the butanediol mononitrate undergoes further metabolism to NO and an inactive 1,4-butanediol moiety. As a gas that can freely diffuse across plasma membranes, it is proposed that the relaxing effect of NO to induce reductions in the cell volume and contractility of vascular smooth muscle-like cells is dependent upon activation of the sGC/cGMP/PKG cascade pathway. NO released from butanediol mononitrate consequently enters the cells of the TM and an inner wall of SC, causing decreases in myosin light chain-2 phosphorylation, increased phosphorylation of large-conductance calcium-activated potassium (BKCa) channels, and a subsequent efflux of potassium ions through such BKCa channels. All of these changes serve to decrease the cell contractility and volume, as well as to rearrange the actin cytoskeleton of the TM and SC cells. These biomechanical changes ultimately allow for enhanced conventional outflow of aqueous humor. — NCATS