Histone deacetylase 4 inhibits NF-κB activation by facilitating IκBα sumoylation

Extracellular Adipose Matrix Hydrogel Laden with Adipose-Derived Stem Cell Modulates Macrophage Polarization for Enhanced Full-Thickness Skin Wound Repair

Adipose-derived stem cells (ADSC) represent a promising approach for wound healing, while the limited survival rate has restricted their application. To address this, we equipped a hydrogel from acellular porcine adipose tissue (HAPA) with ADSC to fabricate the HAPA + ADSC composite hydrogel. In addition to serving as a carrier for stem cell delivery, the bioactive components of the HAPA hydrogel support immune regulation and tissue repair. In this study, we demonstrated that the HAPA + ADSC composite could effectively modulate macrophage polarization, promote angiogenesis, and regulate extracellular matrix (ECM) deposition and remodeling, thereby substantially accelerating wound healing. Additionally, transcriptomic sequencing analysis indicated that the HAPA + ADSC composite upregulated Nfkbia and Nfkbie to inhibit the nuclear transcription of RelA-p50 heterodimer so that macrophages polarization toward an M1 phenotype is suppressed. The combined effects of ADSC and HAPA hydrogel make it a promising candidate for functional skin wound healing.

Histone modifications and metabolic reprogramming in tumor-associated macrophages: a potential target of tumor immunotherapy

Histone modifications, including methylation, acetylation, lactylation, phosphorylation, ubiquitination, SUMOylation, ADP-ribosylation, and crotonylation, critically regulate tumor-associated macrophages (TAMs) polarization by modulating gene expression and functional states. Reprogramming TAMs from M2 to M1 phenotypes through epigenetic targeting has emerged as a promising strategy to enhance anti-tumor immunity and improve the efficacy of cancer immunotherapy. This review explores the role of histone modifications in TAM biology, their interplay with metabolic reprogramming, and the opportunities and challenges in developing epigenetic-based therapies to advance cancer immunotherapy.

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).

LC-MS/MS-Profiling of Human Serum Unveils Significant Increase in Neuroinflammation and Carcinogenesis Following Chronic Organophosphate Exposure

The utilization of organophosphate pesticides (OPs) has escalated in response to the growing global food demand driven by a rapidly increasing population and the environmental disruptions caused by climate change. While acute exposure leads to cholinergic poisoning, chronic OP exposure has been linked to organ dysfunction, inflammation, and carcinogenesis. Serum samples from healthy individuals (n = 11), patients with acute OP exposure (n = 12), and those with chronic OP exposure (n = 31) were analyzed to discern the differentially expressed pathways after acute and chronic OP exposure. Differential expression analysis identified 132 proteins altered in chronic exposure vs control, 86 in acute exposure vs control, and 124 in chronic vs acute exposure. Pathway analysis revealed increased blood coagulation and reduced LXR/RXR activation and DCHR24 signaling in both acute and chronic exposures. Elevated levels of pro-inflammatory proteins, such as S100A8, VWF, and GPIBA, were observed, particularly in chronic exposure, highlighting significant inflammatory effects of OP exposure. These findings provide insights into the pathological mechanisms underlying chronic OP exposure and its contribution to inflammation and long-term health risks.

Metabolic pathways, genomic alterations, and post-translational modifications in pulmonary hypertension and cancer as therapeutic targets and biomarkers

Background

Pulmonary hypertension (PH) can lead to right ventricular hypertrophy, significantly increasing mortality rates. This study aims to clarify PH-specific metabolites and their impact on genomic and post-translational modifications (PTMs) in cancer, evaluating DHA and EPA's therapeutic potential to mitigate oxidative stress and inflammation.

Methods

Data from 289,365 individuals were analyzed using Mendelian randomization to examine 1,400 metabolites' causal roles in PH. Anti-inflammatory and antioxidative effects of DHA and EPA were tested in RAW 264.7 macrophages and cancer cell lines (A549, HCT116, HepG2, LNCaP). Genomic features like CNVs, DNA methylation, tumor mutation burden (TMB), and PTMs were analyzed. DHA and EPA's effects on ROS production and cancer cell proliferation were assessed.

Results

We identified 57 metabolites associated with PH risk and examined key tumor-related pathways through promoter methylation analysis. DHA and EPA significantly reduced ROS levels and inflammatory markers in macrophages, inhibited the proliferation of various cancer cell lines, and decreased nuclear translocation of SUMOylated proteins during oxidative stress and inflammatory responses. These findings suggest a potential anticancer role through the modulation of stress-related nuclear signaling, as well as a regulatory function on cellular PTMs.

Conclusion

This study elucidates metabolic and PTM changes in PH and cancer, indicating DHA and EPA's role in reducing oxidative stress and inflammation. These findings support targeting these pathways for early biomarkers and therapies, potentially improving disease management and patient outcomes.

Nutraceuticals and pharmacological to balance the transitional microbiome to extend immunity during COVID-19 and other viral infections

SCOPE

The underlying medical conditions and gut dysbiosis is known to influence COVID-19 severity in high-risk patients. The current review proposed the optimal usage of nutraceuticals & pharmacological interventions can help regulate the protective immune response and balance the regulatory functionality of gut microbiota. Many studies have revealed that the probiotic interventions viz., Lactobacillus rhamnosus, L. plantarum & other bacterial spp. reduce IFNγ & TNF-α and increase IL-4 & IL-10 secretions to control the immunostimulatory effects in upper respiratory tract infection. Dietary fibres utilized by beneficial microbiota and microbial metabolites can control the NF-kB regulation. Vitamin C halts the propagation of pathogens and vitamin D and A modulate the GM. Selenium and Flavonoids also control the redox regulations. Interferon therapy can antagonize the viral replications, while corticosteroids may reduce the death rates. BCG vaccine reprograms the monocytes to build trained immunity. Bifidobacterium and related microbes were found to increase the vaccine efficacy. Vaccines against COVID-19 and season flu also boost the immunity profile for robust protection. Over all, the collective effects of these therapeutics could help increase the opportunities for faster recovery from infectious diseases.

CONCLUSION

The nutraceutical supplements and pharmacological medicines mediate the modulatory functionalities among beneficial microbes of gut, which in turn eliminate pathogens, harmonize the activity of immune cells to secrete essential regulatory molecular receptors and adaptor proteins establishing the homeostasis in the body organs through essential microbiome. Therefore, the implementation of this methodology could control the severity events during clinical sickness and reduce the mortalities.

Crosstalk between SUMOylation and other post-translational modifications in breast cancer

Breast cancer represents the most prevalent tumor type and a foremost cause of mortality among women globally. The complex pathophysiological processes of breast cancer tumorigenesis and progression are regulated by protein post-translational modifications (PTMs), which are triggered by different carcinogenic factors and signaling pathways, with small ubiquitin-like modifier (SUMOylation) emerging as a particularly pivotal player in this context. Recent studies have demonstrated that SUMOylation does not act alone, but interacts with other PTMs, such as phosphorylation, ubiquitination, acetylation, and methylation, thereby leading to the regulation of various pathological activities in breast cancer. This review explores novel and existing mechanisms of crosstalk between SUMOylation and other PTMs. Typically, SUMOylation is regulated by phosphorylation to exert feedback control, while also modulates subsequent ubiquitination, acetylation, or methylation. The crosstalk pairs in promoting or inhibiting breast cancer are protein-specific and site-specific. In mechanism, alterations in amino acid side chain charges, protein conformations, or the occupation of specific sites at specific domains or sites underlie the complex crosstalk. In summary, this review centers on elucidating the crosstalk between SUMOylation and other PTMs in breast cancer oncogenesis and progression and discuss the molecular mechanisms contributing to these interactions, offering insights into their potential applications in facilitating novel treatments for breast cancer.

Roles of Histone Deacetylase 4 in the Inflammatory and Metabolic Processes

Histone deacetylase 4 (HDAC4), a class IIa HDAC, has gained attention as a potential therapeutic target in treating inflammatory and metabolic processes based on its essential role in various biological pathways by deacetylating non-histone proteins, including transcription factors. The activity of HDAC4 is regulated at the transcriptional, post-transcriptional, and post-translational levels. The functions of HDAC4 are tissue-dependent in response to endogenous and exogenous factors and their substrates. In particular, the association of HDAC4 with non-histone targets, including transcription factors, such as myocyte enhancer factor 2, hypoxia-inducible factor, signal transducer and activator of transcription 1, and forkhead box proteins, play a crucial role in regulating inflammatory and metabolic processes. This review summarizes the regulatory modes of HDAC4 activity and its functions in inflammation, insulin signaling and glucose metabolism, and cardiac muscle development.

Peptide-based PROTACs: Current Challenges and Future Perspectives

Proteolysis-targeting chimeras (PROTACs) are an attractive means to target previously undruggable or drug-resistant mutant proteins. While small molecule-based PROTACs are stable and can cross cell membranes, there is limited availability of suitable small molecule warheads capable of recruiting proteins to an E3 ubiquitin ligase for degradation. With advances in structural biology and in silico protein structure prediction, it is now becoming easier to define highly selective peptides suitable for PROTAC design. As a result, peptide-based PROTACs are becoming a feasible proposition for targeting previously "undruggable" proteins not amenable to small molecule inhibition. In this review, we summarize recent progress in the design and application of peptide-based PROTACs as well as several practical approaches for obtaining candidate peptides for PROTACs. We also discuss the major hurdles preventing the translation of peptide-based PROTACs from bench to bedside, such as their delivery and bioavailability, with the aim of stimulating discussion about how best to accelerate the clinical development of peptide- based PROTACs in the near future.

Non-Psychoactive Phytocannabinoids Inhibit Inflammation-Related Changes of Human Coronary Artery Smooth Muscle and Endothelial Cells

Atherosclerosis is associated with vascular smooth muscle cell proliferation, chronic vascular inflammation, and leukocyte adhesion. In view of the cardioprotective effects of cannabinoids described in recent years, the present study investigated the impact of the non-psychoactive phytocannabinoids cannabidiol (CBD) and tetrahydrocannabivarin (THCV) on proliferation and migration of human coronary artery smooth muscle cells (HCASMC) and on inflammatory markers in human coronary artery endothelial cells (HCAEC). In HCASMC, CBD and THCV at nontoxic concentrations exhibited inhibitory effects on platelet-derived growth factor-triggered proliferation (CBD) and migration (CBD, THCV). When interleukin (IL)-1β- and lipopolysaccharide (LPS)-stimulated HCAEC were examined, both cannabinoids showed a concentration-dependent decrease in the expression of vascular cell adhesion molecule-1 (VCAM-1), which was mediated independently of classical cannabinoid receptors and was not accompanied by a comparable inhibition of intercellular adhesion molecule-1. Further inhibitor experiments demonstrated that reactive oxygen species, p38 mitogen-activated protein kinase activation, histone deacetylase, and nuclear factor κB (NF-κB) underlie IL-1β- and LPS-induced expression of VCAM-1. In this context, CBD and THCV were shown to inhibit phosphorylation of NF-κB regulators in LPS- but not IL-1β-stimulated HCAEC. Stimulation of HCAEC with IL-1β and LPS was associated with increased adhesion of monocytes, which, however, could not be significantly abolished by CBD and THCV. In summary, the results highlight the potential of the non-psychoactive cannabinoids CBD and THCV to regulate inflammation-related changes in HCASMC and HCAEC. Considering their effect on both cell types studied, further preclinical studies could address the use of CBD and THCV in drug-eluting stents for coronary interventions.

Adipose Tissue Macrophage-Mediated Inflammation in Obesity: A Link to Posttranslational Modification

Adipose tissue macrophages (ATM) are an essential type of immune cells in adipose tissue. Obesity induces the inflammation of adipose tissues, as expressed by ATM accumulation, that is more likely to become a source of systemic metabolic diseases, including insulin resistance. The process is characterized by the transcriptional regulation of inflammatory pathways by virtue of signaling molecules such as cytokines and free fatty acids. Notably, posttranslational modification (PTM) is a key link for these signaling molecules to trigger the proinflammatory or anti-inflammatory phenotype of ATMs. This review focuses on summarizing the functions and molecular mechanisms of ATMs regulating inflammation in obese adipose tissue. Furthermore, the role of PTM is elaborated, hoping to identify new horizons of treatment and prevention for obesity-mediated metabolic disease.

The Role of Histone Deacetylases in Acute Lung Injury-Friend or Foe

Acute lung injury (ALI), caused by intrapulmonary or extrapulmonary factors such as pneumonia, shock, and sepsis, eventually disrupts the alveolar-capillary barrier, resulting in diffuse pulmonary oedema and microatasis, manifested by refractory hypoxemia, and respiratory distress. Not only is ALI highly lethal, but even if a patient survives, there are also multiple sequelae. Currently, there is no better treatment than supportive care, and we urgently need to find new targets to improve ALI. Histone deacetylases (HDACs) are epigenetically important enzymes that, together with histone acetylases (HATs), regulate the acetylation levels of histones and non-histones. While HDAC inhibitors (HDACis) play a therapeutic role in cancer, inflammatory, and neurodegenerative diseases, there is also a large body of evidence suggesting the potential of HDACs as therapeutic targets in ALI. This review explores the unique mechanisms of HDACs in different cell types of ALI, including macrophages, pulmonary vascular endothelial cells (VECs), alveolar epithelial cells (AECs), and neutrophils.

Cytoplasmic HDAC4 recovers synaptic function in the 3×Tg mouse model of Alzheimer's disease

AIMS

Early dysfunction in Alzheimer's disease (AD) is characterised by alterations of synapse structure and function leading to dysmorphic neurites, decreased spine density, impaired synaptic plasticity and cognitive deficits. The class II member HDAC4, which recently emerged as a crucial factor in shaping synaptic plasticity and memory, was found to be altered in AD. We investigated how the modulation of HDAC4 may contribute to counteracting AD pathogenesis.

METHODS

Using a cytoplasmic HDAC4 mutant (HDAC4^SD ), we studied the recovery of synaptic function in hippocampal tissue and primary neurons from the triple-transgenic mouse model of AD (3×Tg-AD).

RESULTS

Here, we report that in wild-type mice, HDAC4 is localised at synapses and interacts with postsynaptic proteins, whereas in the 3×Tg-AD, it undergoes nuclear import, reducing its interaction with synaptic proteins. Of note, HDAC4 delocalisation was induced by both amyloid-β and tau accumulation. Overexpression of the HDAC4^SD mutant in CA1 pyramidal neurons of organotypic hippocampal slices obtained from 3×Tg-AD mice increased dendritic length and promoted the enrichment of N-cadherin, GluA1, PSD95 and CaMKII proteins at the synaptic level compared with AD neurons transfected with the empty vector. Moreover, HDAC4 overexpression recovered the level of SUMO2/3ylation of PSD95 in AD hippocampal tissue, and in AD organotypic hippocampal slices, the HDAC4^SD rescued spine density and synaptic transmission.

CONCLUSIONS

These results highlight a new role of cytoplasmic HDAC4 in providing a structural and enzymatic regulation of postsynaptic proteins. Our findings suggest that controlling HDAC4 localisation may represent a promising strategy to rescue synaptic function in AD, potentially leading to memory improvement.

HDAC4 in cancer: A multitasking platform to drive not only epigenetic modifications

Controlling access to genomic information and maintaining its stability are key aspects of cell life. Histone acetylation is a reversible epigenetic modification that allows access to DNA and the assembly of protein complexes that regulate mainly transcription but also other activities. Enzymes known as histone deacetylases (HDACs) are involved in the removal of the acetyl-group or in some cases of small hydrophobic moieties from histones but also from the non-histone substrate. The main achievement of HDACs on histones is to repress transcription and promote the formation of more compact chromatin. There are 18 different HDACs encoded in the human genome. Here we will discuss HDAC4, a member of the class IIa family, and its possible contribution to cancer development.

Ubiquitin Proteasome Gene Signatures in Ependymoma Molecular Subtypes

The ubiquitin proteasome system (UPS) is critically important for cellular homeostasis and affects virtually all key functions in normal and neoplastic cells. Currently, a comprehensive review of the role of the UPS in ependymoma (EPN) brain tumors is lacking but may provide valuable new information on cellular networks specific to different EPN subtypes and reveal future therapeutic targets. We have reviewed publicly available EPN gene transcription datasets encoding components of the UPS pathway. Reactome analysis of these data revealed genes and pathways that were able to distinguish different EPN subtypes with high significance. We identified differential transcription of several genes encoding ubiquitin E2 conjugases associated with EPN subtypes. The expression of the E2 conjugase genes UBE2C, UBE2S, and UBE2I was elevated in the ST_EPN_RELA subtype. The UBE2C and UBE2S enzymes are associated with the ubiquitin ligase anaphase promoting complex (APC/c), which regulates the degradation of substrates associated with cell cycle progression, whereas UBE2I is a Sumo-conjugating enzyme. Additionally, elevated in ST_EPN_RELA were genes for the E3 ligase and histone deacetylase HDAC4 and the F-box cullin ring ligase adaptor FBX031. Cluster analysis demonstrated several genes encoding E3 ligases and their substrate adaptors as EPN subtype specific genetic markers. The most significant Reactome Pathways associated with differentially expressed genes for E3 ligases and their adaptors included antigen presentation, neddylation, sumoylation, and the APC/c complex. Our analysis provides several UPS associated factors that may be attractive markers and future therapeutic targets for the subtype-specific treatment of EPN patients.

Role of Post-translational Modification of Silent Mating Type Information Regulator 2 Homolog 1 in Cancer and Other Disorders

Silent mating type information regulator 2 homolog 1 (SIRT1), an NAD⁺-dependent histone/protein deacetylase, has multifarious physiological roles in development, metabolic regulation, and stress response. Thus, its abnormal expression or malfunction is implicated in pathogenesis of various diseases. SIRT1 undergoes post-translational modifications, including phosphorylation, oxidation/reduction, carbonylation, nitrosylation, glycosylation, ubiquitination/deubiquitination, SUMOylation etc. which can modulate its catalytic activity, stability, subcellular localization, and also binding affinity for substrate proteins. This short review highlights the regulation of SIRT1 post-translational modifications and their pathophysiologic implications.

Serum HDAC4 level in rheumatoid arthritis: Longitudinal change during treatment and correlation with clinical outcomes

Objective

Histone deacetylase 4 (HDAC4) modulates immunity, inflammation, and osteoblast differentiation to engage in rheumatoid arthritis (RA) etiology. This study aimed to evaluate the HDAC4 longitudinal change and its relationship with clinical features and outcomes in RA patients.

Methods

Eighty‐three RA patients were enrolled. Their serum HDAC4 level was detected by ELISA at baseline (W0), week (W) 4, W12, and W24 after treatment. RA patients were divided into response or non‐response, low disease activity (LDA) or non‐LDA, remission or non‐remission patients according to their treatment outcomes at W24. Meanwhile, serum HDAC4 was detected by ELISA in 20 osteoarthritis patients and 20 healthy controls (HCs).

Results

HDAC4 level was reduced in RA patients compared with HCs (p < 0.001) and osteoarthritis patients (p = 0.009). HDAC4 was negatively related to some of the disease activity indexes such as C‐reactive protein (p = 0.003), tender joint count (p = 0.025), and disease activity score based on 28 joints (p = 0.013) in RA patients; it was also negatively correlated with TNF‐α (p = 0.003), IL‐6 (p = 0.022), and IL‐17A (p = 0.015). However, the HDAC4 level was not related to different treatment histories or current initiating treatment regimens (all p < 0.05). After treatment, HDAC4 was gradually elevated along with the time (p < 0.001). Interestingly, HDAC4 level at W12 (p = 0.041) and W24 (p = 0.012) was higher in response patients versus non‐response patients, and its level at W24 was higher in LDA patients versus non‐LDA patients (p = 0.019), and in remission patients versus non‐remission patients (p = 0.039).

Conclusion

HDAC4 gradually increases during treatment and its elevation estimates good treatment outcomes in RA patients.

The Role of SUMO E3 Ligases in Signaling Pathway of Cancer Cells

Small ubiquitin-like modifier (SUMO)ylation is a reversible post-translational modification that plays a crucial role in numerous aspects of cell physiology, including cell cycle regulation, DNA damage repair, and protein trafficking and turnover, which are of importance for cell homeostasis. Mechanistically, SUMOylation is a sequential multi-enzymatic process where SUMO E3 ligases recruit substrates and accelerate the transfer of SUMO onto targets, modulating their interactions, localization, activity, or stability. Accumulating evidence highlights the critical role of dysregulated SUMO E3 ligases in processes associated with the occurrence and development of cancers. In the present review, we summarize the SUMO E3 ligases, in particular, the novel ones recently identified, and discuss their regulatory roles in cancer pathogenesis.

SUMO-Based Regulation of Nuclear Positioning to Spatially Regulate Homologous Recombination Activities at Replication Stress Sites

DNA lesions have properties that allow them to escape their nuclear compartment to achieve DNA repair in another one. Recent studies uncovered that the replication fork, when its progression is impaired, exhibits increased mobility when changing nuclear positioning and anchors to nuclear pore complexes, where specific types of homologous recombination pathways take place. In yeast models, increasing evidence points out that nuclear positioning is regulated by small ubiquitin-like modifier (SUMO) metabolism, which is pivotal to maintaining genome integrity at sites of replication stress. Here, we review how SUMO-based pathways are instrumental to spatially segregate the subsequent steps of homologous recombination during replication fork restart. In particular, we discussed how routing towards nuclear pore complex anchorage allows distinct homologous recombination pathways to take place at halted replication forks.

Histone deacetylase 5 deacetylates the phosphatase PP2A for positively regulating NF-κB signaling

Histone deacetylase 5 (HDAC5) has been reported to have a strong regulatory function in the proinflammatory response, but the mechanism is still unknown. Here, we identified HDAC5 as a positive regulator of NF-κB signaling in vivo. HDAC5-deficient mice exhibited enhanced survival in response to LPS challenge. Using LPS, TNFα, different kinds of viruses, hydrogen peroxide, or ultraviolet stimulation, we demonstrate that HDAC5-mediated regulation of NF-κB occurs in manners both dependent on and independent of IKK, an upstream kinase in the NF-κB signaling pathway. Deficiency in HDAC5 impaired the phosphorylation of IKKβ, subsequent phosphorylation of the NF-κB inhibitor protein IκBα and NF-κB subunit p65. We also show that the phosphatase PP2A repressed transcriptional activation of NF-κB by decreasing phosphorylation of IKKβ, p65, and IκBα. In vitro deacetylation experiments and site-directed mutagenesis experiments indicated that HDAC5 directly deacetylated PP2Ac at Lys136, which resulted in the deactivation of PP2A. Our data add mechanistic insight into the cross talk between epigenetic and posttranslational modifications regulating NF-κB signaling and protein phosphatase activation that mediate survival in response to inflammatory challenges.