BackgroundIntimal hyperplasia is a common cause of many vasculopathies. There has been a recent surge of interest in the bromo and extra-terminal (BET) epigenetic “readers” including BRD4 since the serendipitous discovery of JQ1(+), an inhibitor specific to the seemingly undruggable BET bromodomains. The role of the BET family in the development of intimal hyperplasia is not known.MethodsWe investigated the effect of BET inhibition on intimal hyperplasia using a rat balloon angioplasty model.ResultsWhile BRD4 was dramatically up-regulated in the rat and human hyperplastic neointima, blocking BET bromodomains with JQ1(+) diminished neointima in rats. Knocking down BRD4 with siRNA, or treatment with JQ1(+) but not the inactive enantiomer JQ1(−), abrogated platelet-derived growth factor (PDGF-BB)-stimulated proliferation and migration of primary rat aortic smooth muscle cells. This inhibitory effect of JQ1(+) was reproducible in primary human aortic smooth muscle cells. In human aortic endothelial cells, JQ1(+) prevented cytokine-induced apoptosis and impairment of cell migration. Furthermore, either BRD4 siRNA or JQ1(+) but not JQ1(−), substantially down-regulated PDGF receptor-α which, in JQ1(+)-treated arteries versus vehicle control, was also reduced.ConclusionsBlocking BET bromodomains mitigates neointima formation, suggesting an epigenetic approach for effective prevention of intimal hyperplasia and associated vascular diseases.
Central nervous system (CNS) immune privilege is complex, and it is still not understood how CNS antigens are sampled by the peripheral immune system under steady state conditions. To compare antigen sampling from immune-privileged or nonprivileged tissues, we created transgenic mice with oligodendrocyte or gut epithelial cell expression of an EGFP-tagged fusion protein containing ovalbumin (OVA) antigenic peptides and tested peripheral anti-OVA peptide-specific sentinel OT-I and OT-II T cell activation. We report that oligodendrocyte or gut antigens are sampled similarly, as determined by comparable levels of OT-I T cell activation. However, activated T cells do not access the CNS under steady state conditions. These data show that afferent immunity is normally intact as there is no barrier at the antigen sampling level, but that efferent immunity is restricted. To understand how this one-sided surveillance contributes to CNS immune privilege will help us define mechanisms of CNS autoimmune disease initiation.
A novel biphasic gas/liquid plasma microreactor performed controlled oxidation of cyclohexane into “KA oil” with more than 70% selectivity and more than 10% conversion.
BackgroundThe bromodomain and extraterminal domain (BET) family proteins (BET2, BET3, and BET4) “read” (bind) histone acetylation marks via two distinct bromodomains (Brom1 and Brom2) facilitating transcriptional activation. These epigenetic “readers” play crucial roles in pathogenic processes such as inflammation. The role of BETs in influencing the degenerative process in the retina is however unknown.MethodsWe employed the rd10 mouse model (Pde6b
rd10 mutation) of retinitis pigmentosa (RP) to examine the involvement of BET proteins in retinal neurodegeneration.ResultsInhibition of BET activity by intravitreal delivery of JQ1, a BET-specific inhibitor binding both Brom1 and Brom2, ameliorated photoreceptor degeneration and improved electroretinographic function. Rescue effects of JQ1 were related to the suppression of retinal microglial activation in vivo, as determined by decreased immunostaining of activation markers (IBA1, CD68, TSPO) and messenger RNA (mRNA) levels of inflammatory cytokines in microglia purified from rd10 retinas. JQ1 pre-treatment also suppressed microglial activation in vitro, decreasing microglial proliferation, migration, and mRNA expression of inflammatory cytokines (TNFα, MCP-1, IL-1β, IL-6, and RANTES). Expression of BET2, but not BET3 and BET4, was significantly elevated during photoreceptor degeneration at postnatal day (PN)24 in retinas of rd10 mice relative to age-matched wild-type controls. siRNA knockdown of BET2 but not BET4, and the inhibitor of Brom2 (RVX208) but not of Brom1 (Olinone), decreased microglial activation.ConclusionsThese findings indicate that BET inhibition rescues photoreceptor degeneration likely via the suppression of microglial activation and implicates BET interference as a potential therapeutic strategy for the treatment of degenerative retinal diseases.Electronic supplementary materialThe online version of this article (doi:10.1186/s12974-016-0775-4) contains supplementary material, which is available to authorized users.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.