Novel detection of post-translational modifications in human monocyte-derived dendritic cells after chronic alcohol exposure: Role of inflammation regulator H4K12ac

Abstract

Previous reports on epigenetic mechanisms involved in alcohol abuse have focus on hepatic and neuronal regions, leaving the immune system and specifically monocyte-derived dendritic cells (MDDCs) understudied. Our lab has previously shown histone deacetylases are modulated in cells derived from alcohol users and after in vitro acute alcohol treatment of human MDDCs. In the current study, we developed a novel screening tool using matrix assisted laser desorption ionization-fourier transform-ion cyclotron resonance mass spectrometry (MALDI-FT-ICR MS) and single cell imaging flow cytometry to detect post-translational modifications (PTMs) in human MDDCs due to chronic alcohol exposure. Our results demonstrate, for the first time, in vitro chronic alcohol exposure of MDDCs modulates H3 and H4 and induces a significant increase in acetylation at H4K12 (H4K12ac). Moreover, the Tip60/HAT inhibitor, NU9056, was able to block EtOH-induced H4K12ac, enhancing the effect of EtOH on IL-15, RANTES, TGF-β1, and TNF-α cytokines while restoring MCP-2 levels, suggesting that H4K12ac may be playing a major role during inflammation and may serve as an inflammation regulator or a cellular stress response mechanism under chronic alcohol conditions.

Membrane receptor MerTK is a newly identified transcriptional regulator that associates to chromatin as nanoclusters during human DC differentiation

“…These results are fully in line with a recent study showing a 350 similar increase in the total histone content in pluripotent versus differentiated 351 cells (Karnavas et al, 2014). An additional study also showed that histone content in 352 monocytic-derived DCs can vary significantly upon treatment with different 353 immunological stimuli (Parira et al, 2017). As H2B is directly involved in DNA 354 compaction, our results reveal that chromatin is indeed in a more accessible conformation 355 during early stages of DC differentiation, i.e., at day 0 DCs.…”

Cigarette smoke promotes HIV infection of primary bronchial epithelium and additively suppresses CFTR function

“…Data were acquired and analyzed with Amnis® FlowSight® Imaging Flow Cytometer and IDEAS software. Staining, image collection, and analysis were carried out according to manufacturer’s protocol and as previously published 21 , 22 . As seen in Fig.…”

Epigenetic Mechanisms Regulating the Functional Effects of Chronic Alcohol Exposure of Human Monocyte-derived Dendritic Cells

“…Further, a novel TIP60 inhibitor, NU9056 was being investigated for its effects and role in human neuronal cells (Tan et al, 2016a) . Based on the literature, NU9056 was selected and viability assay like trypan blue and XTT assay was carried out to select 50nM as an optimum concentration for treatment in human MDDCs (data available in publication Parira et al, 2017c). Post differentiation, MDDCs were pre-treated with 50nM NU9056 for 2 hours and then cells receiving alcohol treatment were treated with 0.2% EtOH for five days.…”

“…analyzed according to manufacturer instructions with the RayBiotech inflammation arrays (RayBiotech, Norcross, GA, USA) as previously described by us (Agudelo et al, 2013, Parira et al, 2017c, Parira et al, 2017a. Briefly, supernatants from cells after 5-day posttreatment with NU9056, 0.2% EtOH and 0.2% EtOH + NU9056 and an untreated control were assayed for the experiment.…”

“…In all assays, treatments of NU9056 were incorporated to understand the role of H4K12ac and CID was incorporated to understand the role of GPR55. Image acquisition by Amnis® FlowSight® Imaging Flow Cytometer and analysis by IDEAS® image software was carried out as previously described by us , Parira et al, 2017c (Parira et al, 2017a). For each experiment, from all events collected, FITC positive cells were gated from single cells.…”