PDF《Induced Plasticity》

1501 NW 10th Avenue, BRB-407 (M-860), Miami, FL 33136. E-mail: [email protected]. DOI:10.1523/JNEUROSCI.0826-15.2015 Copyright ?

2015 the authors 0270-6474/15/3515062-11$15.00/0 Significance Statement Proteinsinvolvedinthe readout oflysineacetylationmarks,referredtoasBETbromodomainproteins(includingBRD2,BRD3, BRD4, and BRDT), have been shown to be key regulators of chromatin dynamics and disease, and BET inhibitors are currently being studied in several clinical trials. However, their role in addiction-related phenomena remains unknown. In the current studies, we revealed that BRD4 is elevated in the nucleus accumbens and recruited to promoter regions of addiction-related genes following repeated cocaine administration, and that inhibition of BRD4 attenuates transcriptional and behavioral responses to cocaine. Together, these studies reveal that BET inhibitors may have therapeutic utility in the treatment of cocaine addiction.

15062 ? The Journal of Neuroscience, November 11,

2015 ? 35(45):15062C15072 ulators of histone lysine acetylation have recently come to light. For instance, proteins involved in the readout of lysine acetylation marks, referred to as bromodomain-containing proteins (BRDs), have been shown to be key regulators of chromatin dynamics and the disease-associated acetylome (for review, see Prinjha et al., 2012;

Filippakopoulos and Knapp, 2014), but their involvement in addic- tion is currently unknown. The bromodomain and extraterminal domain (BET) family of proteins (BRD2, BRD3, BRD4, and BRDT) contain two bro- modomains, which bind acetylated histone tails and are involved in transcriptional coactivation and elongation (Dhalluin et al., 1999;

Winston and Allis, 1999;

Owen et al., 2000;

Patel et al., 2013). In particular, BET proteins have high affinity for clustered polyacetylated histone lysine sites but also bind to monoacety- lated lysines with modest affinity (Dey et al., 2003;

Morinie `re et al., 2009). Genome-wide analysis studies have revealed that BET- bound nucleosomes are enriched in histone post-translational modifications that regulate actively transcribed euchromatin, and BRD4-bound sites are highly correlated with increased gene expression (LeRoy et al., 2012) and play a role in super-enhancer function (Zhang et al., 2012;

Brown et al., 2014). With the devel- opment of selective, small-molecule inhibitors of BET bromodo- mains (Filippakopoulos et al., 2010;

Chung et al., 2011), there has been increasing interest in their therapeutic utility (Delmore et al., 2011;

Zuber et al., 2011;

Belkina and Denis, 2012;

Barrett et al., 2014), and inhibitors of these proteins are currently being tested in clinical trials for treatment of several diseases (www.Clinical- trials.gov;

IDs NCT01713582, NCT01949883, NCT02157636, NCT01987362, and NCT01587703). However, it is unclear whether BET proteins regulate molecular and behavioral aspects of addiction. Given that histone acetylation mechanisms regulate cocaine-induced neuroadaptations and behaviors (LaPlant and Nestler, 2011), we hypothesized that BET proteins may also play a vital role in addiction-related phenomena. Using behavioral, pharmacological, and molecular techniques, we show that BET proteins are upregulated and recruited to promoter region of Bdnf in the NAc following repeated cocaine administration and that inhibition of these proteins attenuates transcriptional and behavioral responses to cocaine. Together, these studies indicate that the displacement of BET proteins from chromatin may have therapeutic efficacy in addiction-related behaviors. Materials and Methods Animals Male C57BL/6 mice (8C10 weeks old) and Sprague Dawley rats (initial weight ?300C325 g, Charles River Laboratories) were housed 2C4 ani- mals per cage under a regular