Histone Deacetylase 1 (HDAC1)

Overview

Histone deacetylase 1 (HDAC1) is a member of the class I histone deacetylase family and a nuclear enzyme that removes acetyl groups from lysine residues on histone and non-histone proteins. By promoting chromatin condensation and altering transcriptional accessibility, HDAC1 helps regulate gene expression programs involved in cell proliferation, differentiation, stress responses, inflammation, and metabolic control. It is therefore an important epigenetic regulator in both normal physiology and disease.

In biomedical research, HDAC1 is frequently studied as a therapeutic target because altered HDAC1 activity or expression can contribute to inflammatory signaling, endothelial dysfunction, metabolic disease, and other pathological states. It is also used as a reference selectivity target in drug discovery, particularly in the development of HDAC inhibitors designed to distinguish HDAC1 from related isoforms such as HDAC6.

Recent Publications Summary

Recent studies have continued to implicate HDAC1 as a key epigenetic regulator in cancer, inflammation, and metabolic disease. In pancreatic ductal adenocarcinoma, class I HDACs including HDAC1/2 were shown to control the genomic distribution of H3K27ac and maintain BRD4 and RNA polymerase II occupancy at DNA damage response gene promoters; HDAC inhibition with entinostat redistributed transcriptional machinery away from these promoters, suppressed DDR gene expression, increased DNA damage, and sensitized tumors to DNA-damaging and DDR-targeting agents 42348617Jun. To improve tumor selectivity, the same study developed bottlebrush prodrug nanoparticles for entinostat delivery, which achieved tumor-specific HDAC inhibition with reduced systemic toxicity 42348617Jun.

HDAC1 was also linked to endothelial dysfunction in diabetes. In endothelial cells exposed to intermittent high glucose, HDAC1 expression increased alongside reduced H4K5 acetylation, elevated ICAM1 and p21, and decreased KLF2 and eNOS, while diabetic rat glomeruli similarly showed increased HDAC1 and reduced H4K5 acetylation in glomerular endothelium 42207449May. These findings supported a mechanism in which enhanced HDAC1-mediated H4K5 deacetylation contributes to endothelial inflammation through repression of the KLF2-eNOS axis 42207449May. In another disease context, a study of lncRNA PAX8-AS1 in sepsis proposed regulation through the miR-34a-5p/HDAC1 axis, indicating ongoing interest in HDAC1-linked noncoding RNA networks in inflammatory disease 42154028May.

Several medicinal chemistry studies also evaluated HDAC1 as a target for isoform-selective inhibitor development. Novel N-arylamide-quinoline derivatives were reported to inhibit HDAC1, HDAC2, HDAC3, and HDAC10, with compound 6b showing potent activity against these isoforms and no activity against HDAC4-9; it also induced histone H3 hyperacetylation, apoptosis-related protein changes including BAX, BAK, and BCL-2, and G0/G1 arrest in cancer cells 41997004Apr. Likewise, indole-based derivatives derived from vorinostat and entinostat were designed against HDAC1 and HDAC6, with benzamide derivatives showing preferential HDAC1 inhibition and one compound, 23c, favoring HDAC1 over HDAC6 41880788Mar. A separate computational study identified vernomenin as a ligand linked to fever-related targets including HDAC1, although the strongest binding in that analysis was to SIRT1 41691789Feb.

Outside oncology and inflammation, HDAC1 appeared in a proteomic study of follicular thyroid cancer progression, where selected proteins were prioritized for distinguishing follicular thyroid carcinoma from adenoma and were further examined by co-immunoprecipitation, immunofluorescence, gene interference, overexpression, and immunohistochemistry. In metabolic disease, Huanglian Wendan Decoction was reported to attenuate hepatic inflammation and lipogenesis via inhibition of the NF-κB/HDAC1/SREBP-1c axis in metabolic dysfunction-associated steatohepatitis, further extending HDAC1’s relevance to liver pathology 42276391Jun.

What Changes, What Holds

1. HDAC1 now looks like a context-dependent driver of DNA-damage response gene accessibility in pancreatic cancer
REINFORCES The new work extends the established view of HDAC1 as a transcriptional regulator by showing that class I HDAC activity can sustain promoter occupancy of BRD4 and RNA polymerase II at DNA damage response genes in pancreatic ductal adenocarcinoma 42348617Jun. That strengthens the case for HDAC1-directed inhibition as a way to alter tumor transcriptional programs, while also suggesting that delivery strategy matters if systemic toxicity is to be avoided.

2. HDAC1-mediated deacetylation appears to be a mechanistic link between diabetic glucose stress and endothelial inflammation
NEW DIRECTION The Overview already places HDAC1 in endothelial dysfunction and inflammatory signaling, but not specifically in the KLF2-eNOS axis or glomerular endothelium. These findings add a more defined disease mechanism in diabetes, with increased HDAC1 and reduced H4K5 acetylation aligning with inflammatory activation 42207449May. The noncoding-RNA sepsis result points in the same general direction, but remains a separate regulatory layer rather than a settled mechanism 42154028May.

3. HDAC1 remains a useful medicinal-chemistry target, but selectivity claims are still compound-specific rather than isoform-general
REINFORCES The recent inhibitor studies do not overturn the established role of HDAC1 in drug discovery; they sharpen it by showing that new scaffolds can preferentially hit HDAC1 over related HDACs in some cases 41997004Apr41880788Mar. That supports the baseline view of HDAC1 as a reference selectivity target, while also underscoring that potency against HDAC1 often comes bundled with activity against other class I isoforms.

4. HDAC1 is being pulled into additional disease settings, but these reports mainly broaden relevance rather than redefine function
NEW DIRECTION The thyroid-cancer proteomic work and the steatohepatitis study extend HDAC1 into tumor progression and metabolic liver disease, areas the Overview does not specifically cover42276391Jun. The liver finding is the more mechanistically informative one because it ties HDAC1 to an NF-κB/SREBP-1c inflammatory-lipogenic axis, whereas the thyroid study mainly supports HDAC1 as a candidate marker or node in a broader protein network. Neither displaces the baseline account.

Overview update candidates: HDAC1 involvement in diabetic endothelial dysfunction via H4K5 deacetylation and the KLF2-eNOS axis; HDAC1 participation in metabolic dysfunction-associated steatohepatitis through the NF-κB/HDAC1/SREBP-1c axis.