hromatin immunoprecipitation (ChIP) analysis of histone H3/4 acetylation at HDAC promoters: Differential effects of modafinil and methamphetamine on the mouse prefrontal cortex

BISAGNO, VERÓNICA; TORRES, OSCAR V.; SOSA, MÁXIMO H.; CADET, JEAN-LUD; GONZÁLEZ, BETINA; JAYANTHI, SUBRAMANIAM; URBANO, FRANCISCO J.; BERNARDI, ALEJANDRA; GOMEZ, NATALIA; GARCÍA-RILL, EDGAR

San Diego

Congreso; SFN Neuroscience 2018; 2018

Methamphetamine (METH) and modafinil are psychostimulants with different addictive and cognitive profiles: METH causes neuroplastic changes that negatively impact the prefrontal cortex (PFC) leading to cognitive deficits and addiction. In contrast, modafinil has little abuse liability and is a cognitive enhancer that improves PFC function. Epigenetic mechanisms are contributory factors in drug-induced neuroadaptations. Specifically, acetylation of histone tails appears to be involved in long-term plasticity associated with cognition and addiction. Histone deacetylases (HDACs) are key players that regulate chromatin functions, thus generating short-term and long-term metaplastic cellular changes responsible for mnemonic adaptations. In the brain, these mechanisms may be pivotal for drug-induced alterations in gene expression and behavioral manifestations. HDACs are divided into zinc-dependent (classical HDACs) or NAD-dependent (sirtuins 1-7) enzymes. Classical HDACs are clustered in class I (HDAC1-3 and 8), class II (HDAC4-7, 9, and 10), or class IV (HDAC11). Class III HDACs are the sirtuins (Sirt1-Sirt7). In our continuing efforts to identify epigenetic effects of METH and modafinil, we tested the possibility that a single dose or chronic administration of these drugs might be followed by changes in histone acetylation (H3ac and H4ac) at the promoters of various HDACs using mouse mPFC. METH (1 mg/kg) or modafinil (90 mg/kg) were administered as a single-dose or repeatedly (daily for 7 days and 4 days washout) and the PFC was used in chromatin immunoprecipitation (ChIP)-PCR studies. We found that, after a single injection, i) METH increased H4Ac abundance at Hdac1 and Hdac10 promoters, but decreased H4Ac acetylation at Hdac4 and Hdac5 promoters; ii) modafinil increased H3Ac but decreased H4Ac at the Hdac7 promoter; iii) both drugs decreased H4Ac at Hdac2 and Hdac8 promoters. Repeated injections were associated with different epigenetic modifications. Specifically, i) METH increased H3Ac at the Sirt3 promoter and H4Ac at Hdac4, Hdac5, Hdac11 and Sirt2 promoters, but promoted decreased H3Ac at Hdac1 and Hdac8 promoters and decreased H4Ac at the Sirt7 promoter; METH also decreased both H3 and H4 acetylation at the Hdac2 promoter; ii) both drugs increased H3 acetylation at Hdac3, Hdac4 and Sirt6 promoters but decreased H4 acetylation at the Hdac8 promoter. These results show different patterns of epigenetic modifications after single-dose in contrast to repeated injections. Specific METH- and modafinil-induced epigenetic alterations may play important roles in the differential effects of the drugs on cognition, addiction, and mPFC functions.