Lens protein glycation

Lens protein glycation is a pathological post-translational modification process involving the non-enzymatic reaction between reducing sugars and the amino groups of long-lived lens crystallins (alpha, beta, and gamma). Because lens crystallins lack turnover and persist throughout an individual's lifetime, they are exceptionally susceptible to the cumulative accumulation of Advanced Glycation End-products (AGEs). This process leads to significant structural alterations, including protein unfolding, cross-linking, and the formation of high-molecular-weight aggregates that impair light transmission and increase scattering. Clinically, lens protein glycation is a primary driver in the pathogenesis of age-related and diabetic cataracts, as well as the age-dependent hardening of the lens known as presbyopia. Therapeutic strategies focus on inhibiting the early stages of the Maillard reaction, scavenging reactive dicarbonyls like methylglyoxal, or maintaining the chaperone function of alpha-crystallin. While various pharmacological agents like pirenoxine and carnosine are used to slow progression, surgical replacement of the lens remains the standard of care for restoring vision in advanced cases.

Other names

Lens crystallin glycationNon-enzymatic glycosylation of lens proteinsAdvanced glycation end-product formation in the lensCrystallin glycationMaillard reaction in the lens

Inhibition of non-enzymatic glycation (Maillard reaction) by preventing the formation of Schiff bases and Amadori products, scavenging reactive dicarbonyl intermediates such as methylglyoxal, and preventing the cross-linking and aggregation of lens crystallins. Some agents also act by maintaining or restoring the molecular chaperone activity of alpha-crystallin.