Tunneling nanotubes and actin cytoskeleton dynamics in glaucoma

Glaucoma is an eye condition characterized by increased intraocular pressure that damages the retina and optic nerve, leading to irreversible blindness if left untreated. The human eye has various components, including the cornea, iris, pupil, lens, and optic nerve. Aqueous humor is secreted by the epithelium of the ciliary body in the posterior chamber and flows through the trabecular meshwork and canal of Schlemm, maintaining normal intraocular pressure. The trabecular meshwork and the canal...

Complex microtubule structures are present in resting cells and in dividing cells. In resting cells, they are responsible for maintaining the cellular architecture, tracks for intracellular transport, positioning of organelles, assembly of cilia and flagella. They mediate the bipolar spindle assembly for chromosomal segregation and positioning of the cell division plate in dividing cells. The formation of microtubule complex structures depends on the cell type, cell stage, and cell function.

Actin filaments undergo polymerization and depolymerization from either end. The polymerization and depolymerization rates depend on the cytosolic concentration of free G-actins. The polymerization rate is generally higher at the plus or barbed end, while the depolymerization rate is higher at the minus or pointed end. At a steady state, critical concentration describes the concentration of free G-actin monomers at which the polymerization rate at the plus end is equal to that of the...

In open-angle glaucoma, the iridocorneal angle remains open, but the trabecular meshwork becomes stiff, slowing down the outflow of aqueous humor. This causes a buildup of aqueous humor in the anterior chamber, leading to a sudden increase in intraocular pressure. The treatment for open-angle glaucoma focuses on reducing the elevated intraocular pressure by either decreasing the secretion of aqueous humor or increasing its outflow.
Drugs such as carbonic anhydrase inhibitors, α2- and...

Actin is a family of globular proteins that are highly abundant in eukaryotic cells. It makes up approximately 1-5% of total cell protein concentration. Actin monomers polymerize to form a complex network of polarized filaments, the actin cytoskeleton, that plays a crucial role in many cellular processes, including cell motility, division, endocytosis, and metastasis of cancer cells.
Actin cytoskeleton dynamics can produce pushing, pulling, and resistance forces that help the cell to migrate....