Retinal Neuroprotective Effect of Sirtuins

istone deacetylases (HDACs) are enzymes that deacetylate histones, but also act on certain non-histone substrates. Class III HDACs, which are known as sirtuins, catalyze deacetylation of the acetyl-lysine residues of histones using nicotinamide adenine dinucleotide (NAD+) as a cofactor. Silent information regulator 2 (Sir2) was the first gene of the sirtuin family to be discovered. Sir2 shows a high level of evolutionary conservation and is an important regulator of senescence, cell differentiation, stress tolerance, metabolism, and cancer in several organisms. Sirtuins have been suggested to have a role in aging [1,2], calorie restriction [1-10], and inflammation. Overexpression of Sir2 prolongs the lifespan of various organisms, whereas deletion or mutation of Sir2 leads to a shorter lifespan [11-13]. Seven human Sir2 homologues (sirtuins) have been identified to date, and these are designated as SIRT1 to SIRT7 [14-15]. Sirtuins are also important in preventing age-related ocular diseases [16]. In this review, we focus on the retinal neuroprotective effect of sirtuins.