Since the NAD+-dependent histone deacetylases sirtuin-1 (SIRT1) and sirtuin-2 (SIRT2) are critically involved in epigenetics, endocrinology and immunology and affect the longevity in model organisms, we investigated their expression in brains of 3-month-old and 14–15 months old rat model of depression Flinders Sensitive Line (FSL) and control Flinders Resistant Line (FRL) rats. In view of the dysregulated NPY system in depression, we also studied NPY in young and old FSL to explore the temporal trajectory of depressive-like–ageing interaction. Sirt1, Sirt2 and Npy mRNA were determined using qRT-PCR in prefrontal cortex (PFC) from young and old FSL and FRL, and in hippocampi from young FSL and FRL. PFC: Sirt1 expression was decreased in FSL (p = 0.001). An interaction between age and genotype was found (p = 0.032); young FSL had lower Sirt1 with respect to both age (p = 0.026) and genotype (p = 0.001). Sirt2 was lower in FSL (p = 0.003). Npy mRNA was downregulated in FSL (p = 0.001) but did not differ between the young and old rat groups. Hippocampus: Sirt1 was reduced in young FSL compared to young FRL (p = 0.005). There was no difference in Sirt2 between FSL and FRL. Npy levels were decreased in hippocampus of young FSL compared to young FRL (p = 0.003). Effects of ageing could not be investigated due to loss of samples. To conclude, i this is the first demonstration that SIRT1 and SIRT2 are changed in brain of FSL, a rat model of depression; ii the changes are age-dependent; iii sirtuins are potential targets for treatment of age-related neurodegenerative diseases.

Sirtuins, NAD-dependent histone deacetylase (HDAC), are correlated to aging and antioxidant. The aim of this study was to determine breed differences of porcine Sirtuins expression and antioxidant capacity in brain between Jinhua pigs (a fatty breed of China) and Danish Landrace pigs (a leaner breed). Effect of age on Sirtuins’ expression was also investigated. At the age of 180 days, the mRNA levels of Sirt1, as well as Sirt2 and Sirt4, in Jinhua pigs were greater, but the mRNA levels of Sirt3, Sirt5, Sirt6, and Sirt7 of Jinhua pigs were lower compared with Danish Landrace pigs. Likewise, at the same BW of 64 kg, the mRNA levels of Sirtuins, except Sirt5 and Sirt7, in Jinhua pigs were greater than Danish Landrace pigs. Meanwhile, Jinhua pigs possessed higher antioxidants activity than Danish Landrace pigs either at the same age or at the same BW. Furthermore, mRNA levels of Sirtuins were decreased with age in brain of the two breeds from 30 to 120 days. The results indicated that Sirtuins expression in brain was different between fatty and lean pigs, and Sirtuins expression may be correlated to antioxidant capacity. In addition, age could down-regulate Siruins expression in porcine brain.