Maintenance of HDACs and H3K9me3 Prevents Arterial Flow-Induced Venous Endothelial Damage

The Histone Deacetylase Activator ITSA-1 Improves the Prognosis of Cardiac Arrest Rats by Alleviating Systemic Inflammatory Responses Following Cardiopulmonary Resuscitation

Objective: To investigate whether the histone deacetylase (HDAC) activator ITSA-1 can ameliorate systemic inflammation after cardiac arrest (CA), thereby enhancing cardiac function and neurological outcomes in rats. Materials and Methods: Sixty-nine healthy adult male Wistar rats were subjected to 12 min of CA induced by Vecuronium bromide. The rats were randomly assigned to five groups: normal control, sham operation, control, suberoylanilide hydroxamic acid (SAHA), and ITSA-1. The study evaluated the effects of ITSA-1 on cardiac function, survival, and neurological functions, including the neurological deficit score (NDS) at 24-, 48-, and 72-h post-return of spontaneous circulation (ROSC) and Morris water maze performance at 72 h. Additionally, levels of TNF-α, IL-1β, glial fibrillary acidic protein (GFAP), S100β in plasma, and TNF-α, IL-1β in the hippocampus were measured 4 h post-ROSC. Western blot analysis was used to assess HDACs, nuclear factor kappa B (NF-κB), p-NF-κB, caspase-3, cleaved caspase-3, Bcl-2, and Bax protein expressions. Results: ITSA-1 reduced basic life support (BLS) duration and adrenaline dosage during cardiopulmonary resuscitation (CPR) and improved cardiac and neural functions, enhancing survival compared to the control and SAHA groups. ITSA-1 decreased serum levels of IL-1β, TNF-α, GFAP, S100β, and hippocampal TNF-α, IL-1β, promoting neuronal survival in the CA1 region. It also inhibited glial cell activation and reduced histone acetylation, blocking the NF-κB pathway and neuronal apoptosis. Conclusion: ITSA-1 enhances the recovery and survival of post-ROSC rats by diminishing histone acetylation and mitigating systemic inflammation. This effect is possibly due to the inhibition of glial cell activation, increased neuronal survival in the brain, and improved cardiac output (CO) and ejection fraction (EF).

HDAC3 in action: Expanding roles in inflammation and inflammatory diseases

Inflammation serves as the foundation for numerous physiological and pathological processes, driving the onset and progression of various diseases. Histone deacetylase 3 (HDAC3), an essential chromatin-modifying protein within the histone deacetylase superfamily, exerts its transcriptional inhibitory role through enzymatic histone modification to uphold normal physiological function, growth, and development of the body. With both enzymatic and non-enzymatic activities, HDAC3 plays a pivotal role in regulating diverse transcription factors associated with inflammatory responses and related diseases. This review examines the involvement of HDAC3 in inflammatory responses while exploring its therapeutic potential as a target for treating inflammatory diseases, thereby offering valuable insights for clinical applications.

Targeting histone deacetylases in head and neck squamous cell carcinoma: molecular mechanisms and therapeutic targets

The onerous health and economic burden associated with head and neck squamous cell carcinoma (HNSCC) is a global predicament. Despite the advent of novel surgical techniques and therapeutic protocols, there is an incessant need for efficacious diagnostic and therapeutic targets to monitor the invasion, metastasis and recurrence of HNSCC due to its substantial morbidity and mortality. The differential expression patterns of histone deacetylases (HDACs), a group of enzymes responsible for modifying histones and regulating gene expression, have been demonstrated in neoplastic tissues. However, there is limited knowledge regarding the role of HDACs in HNSCC. Consequently, this review aims to summarize the existing research findings and explore the potential association between HDACs and HNSCC, offering fresh perspectives on therapeutic approaches targeting HDACs that could potentially enhance the efficacy of HNSCC treatment. Additionally, the Cancer Genome Atlas (TCGA) dataset, CPTAC, HPA, OmicShare, GeneMANIA and STRING databases are utilized to provide supplementary evidence on the differential expression of HDACs, their prognostic significance and predicting functions in HNSCC patients.

Oscillatory shear stress promotes vein graft intimal hyperplasia via NADPH oxidase-related pathways

Background

Uncontrolled intimal hyperplasia (IH) after autologous saphenous vein grafting triggers a high restenosis rate; however, its association with the activation of NADPH oxidase (NOX)-related pathways is unclear. Here, we investigated the effects and mechanism of oscillatory shear stress (OSS) on grafted vein IH.

Methods

Thirty male New Zealand rabbits were randomly divided into control, high-OSS (HOSS), and low-OSS (LOSS) groups, and the vein grafts were harvested after 4 weeks. Hematoxylin and eosin staining and Masson staining assays were used to observe morphological and structural changes. Immunohistochemical staining was used to detect α-SMA, PCNA, MMP-2, and MMP-9 expression. Immunofluorescence staining was used to observe reactive oxygen species (ROS) production in the tissues. Western blotting was used to determine the expression levels of pathway-related proteins (NOX1, NOX2, AKT, p-AKT, and BIRC5), PCNA, BCL-2, BAX, and caspase-3/cleaved caspase-3 in tissues.

Results

Blood flow velocity was lower in the LOSS group than in the HOSS group, while vessel diameter did not change significantly. Shear rate was elevated in both HOSS and LOSS groups but was higher in the HOSS group. Additionally, vessel diameter increased with time in the HOSS and LOSS groups, whereas flow velocity did not. Intimal hyperplasia was significantly lower in the LOSS group than in the HOSS group. IH was dominated by smooth muscle fibers in the grafted veins and collagen fibers in the media. OSS restriction significantly reduced the α-SMA, PCNA, MMP-2, and MMP-9 levels. Moreover, ROS production and the expression of NOX1, NOX2, p-AKT, BIRC5, PCNA, BCL-2, BAX, and cleaved caspase-3 were phase-reduced in LOSS compared to the levels in the HOSS group. Total AKT was not differentially expressed among the three groups.

Conclusion

OSS promotes the proliferation, migration, and survival of subendothelial vascular smooth muscle cells in grafted veins, which may be related to the regulation of downstream p-AKT/BIRC5 levels through the increased production of ROS by NOX. Drugs inhibiting this pathway might be used to prolong vein graft survival time.

Transcriptional and Epigenetic Factors Associated with Early Thrombosis of Femoral Artery Involved in Arteriovenous Fistula

Arteriovenous fistulas (AVFs), created for hemodialysis in end-stage renal disease patients, mature through the outward remodeling of the outflow vein. However, early thrombosis and chronic inflammation are detrimental to the process of AVF maturation and precipitate AVF maturation failure. For the successful remodeling of the outflow vein, blood flow through the fistula is essential, but early arterial thrombosis attenuates this blood flow, and the vessels become thrombosed and stenosed, leading to AVF failure. The altered expression of various proteins involved in maintaining vessel patency or thrombosis is regulated by genes of which the expression is regulated by transcription factors and microRNAs. In this study, using thrombosed and stenosed arteries following AVF creation, we delineated transcription factors and microRNAs associated with differentially expressed genes in bulk RNA sequencing data using upstream and causal network analysis. We observed changes in many transcription factors and microRNAs that are involved in angiogenesis; vascular smooth muscle cell proliferation, migration, and phenotypic changes; endothelial cell function; hypoxia; oxidative stress; vessel remodeling; immune responses; and inflammation. These factors and microRNAs play a critical role in the underlying molecular mechanisms in AVF maturation. We also observed epigenetic factors involved in gene regulation associated with these molecular mechanisms. The results of this study indicate the importance of investigating the transcriptional and epigenetic regulation of AVF maturation and maturation failure and targeting factors precipitating early thrombosis and stenosis.

Expression and Regulation Network of HDAC3 in Acute Myeloid Leukemia and the Implication for Targeted Therapy Based on Multidataset Data Mining

Background

Histone deacetylase 3 (HDAC3) plays an important role in the development and progression of a variety of cancers, but its regulatory mechanism in acute myeloid leukemia (LAML) is not entirely understood.

Methods

We analyzed the expression of HDAC3 in normal and cancerous tissues using Oncomine, UALCAN, and GEO databases. Changes of the HDAC3 gene were analyzed by cBioPortal. The genes coexpressed with HDAC3 were analyzed by WebGestalt, and the predicted signaling pathways in KEGG were discussed.

Results

We discovered that the expression of HDAC3 was elevated in some types of acute myeloid leukemia. The HDAC3 gene has a strong positive correlation with SLC25A5, NDUFA2, Cox4I1, and EIF3K, which regulate cell growth and development. HDAC3 transcription is higher in patients with FLT3 mutation than in healthy people. HDAC3 can be directly involved in regulating the thyroid hormone signaling pathway. MEF2D is directly involved in the cGMP-PKG signaling pathway, and the HDAC3 gene has a strong synergistic relationship with MEF2D. HDAC3 is indirectly involved in the cGMP-PKG signaling pathway, thereby indirectly regulating the expression levels of p53 and p21 genes in patients with LAML. Genomics of Drug Sensitivity in Cancer (GDSC) database analysis revealed that the application of the HDAC3 inhibitor can inhibit the proliferation of leukemia cells.

Conclusions

Therefore, our data suggest that HDAC3 may be a possible therapeutic target for acute myeloid leukemia.

Histone Deacetylase 3: A Potential Therapeutic Target for Atherosclerosis

Atherosclerosis, the pathological basis of most cardiovascular disease, is characterized by plaque formation in the intima. Secondary lesions include intraplaque hemorrhage, plaque rupture, and local thrombosis. Vascular endothelial function impairment and smooth muscle cell migration lead to vascular dysfunction, which is conducive to the formation of macrophage-derived foam cells and aggravates inflammatory response and lipid accumulation that cause atherosclerosis. Histone deacetylase (HDAC) is an epigenetic modifying enzyme closely related to chromatin structure and gene transcriptional regulation. Emerging studies have demonstrated that the Class I member HDAC3 of the HDAC super family has cell-specific functions in atherosclerosis, including 1) maintenance of endothelial integrity and functions, 2) regulation of vascular smooth muscle cell proliferation and migration, 3) modulation of macrophage phenotype, and 4) influence on foam cell formation. Although several studies have shown that HDAC3 may be a promising therapeutic target, only a few HDAC3-selective inhibitors have been thoroughly researched and reported. Here, we specifically summarize the impact of HDAC3 and its inhibitors on vascular function, inflammation, lipid accumulation, and plaque stability in the development of atherosclerosis with the hopes of opening up new opportunities for the treatment of cardiovascular diseases.

Sodium phenylbutyrate inhibits Schwann cell inflammation via HDAC and NFκB to promote axonal regeneration and remyelination

Background

Epigenetic regulation by histone deacetylases (HDACs) in Schwann cells (SCs) after injury facilitates them to undergo de- and redifferentiation processes necessary to support various stages of nerve repair. Although de-differentiation activates the synthesis and secretion of inflammatory cytokines by SCs to initiate an immune response during nerve repair, changes in either the timing or duration of prolonged inflammation mediated by SCs can affect later processes associated with repair and regeneration. Limited studies have investigated the regulatory processes through which HDACs in SCs control inflammatory cytokines to provide a favorable environment for peripheral nerve regeneration.

Methods

We employed the HDAC inhibitor (HDACi) sodium phenylbutyrate (PBA) to address this question in an in vitro RT4 SC inflammation model and an in vivo sciatic nerve transection injury model to examine the effects of HDAC inhibition on the expression of pro-inflammatory cytokines. Furthermore, we assessed the outcomes of suppression of extended inflammation on the regenerative potential of nerves by assessing axonal regeneration, remyelination, and reinnervation.

Results

Significant reductions in lipopolysaccharide (LPS)-induced pro-inflammatory cytokine (tumor necrosis factor-α [TNFα]) expression and secretion were observed in vitro following PBA treatment. PBA treatment also affected the transient changes in nuclear factor κB (NFκB)-p65 phosphorylation and translocation in response to LPS induction in RT4 SCs. Similarly, PBA mediated long-term suppressive effects on HDAC3 expression and activity. PBA administration resulted in marked inhibition of pro-inflammatory cytokine secretion at the site of transection injury when compared with that in the hydrogel control group at 6-week post-injury. A conducive microenvironment for axonal regrowth and remyelination was generated by increasing expression levels of protein gene product 9.5 (PGP9.5) and myelin basic protein (MBP) in regenerating nerve tissues. PBA administration increased the relative gastrocnemius muscle weight percentage and maintained the intactness of muscle bundles when compared with those in the hydrogel control group.

Conclusions

Suppressing the lengthened state of inflammation using PBA treatment favors axonal regrowth and remyelination following nerve transection injury. PBA treatment also regulates pro-inflammatory cytokine expression by inhibiting the transcriptional activation of NFκB-p65 and HDAC3 in SCs in vitro.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12974-021-02273-1.