Histone Deacetylase 3 Couples Mitochondria to Drive IL-1β-Dependent Inflammation by Configuring Fatty Acid Oxidation

Histone modifications in the regulation of erythropoiesis

INTRODUCTION

The pathogenesis of anemia and other erythroid dysphasia are mains poorly understood, primarily due to limited knowledge about the differentiation processes and regulatory mechanisms governing erythropoiesis. Erythropoiesis is a highly complex and precise biological process, that can be categorized into three distinct stages: early erythropoiesis, terminal erythroid differentiation, and reticulocyte maturation, and this complex process is tightly controlled by multiple regulatory factors. Emerging evidence highlights the crucial role of epigenetic modifications, particularly histone modifications, in regulating erythropoiesis. Methylation and acetylation are two common modification forms that affect genome accessibility by altering the state of chromatin, thereby regulating gene expression during erythropoiesis.

DISCUSSION

This review systematically examines the roles of histone methylation and acetylation, along with their respective regulatory enzymes, in regulating the development and differentiation of hematopoietic stem/progenitor cells (HSPCs) and erythroid progenitors. Furthermore, we discuss the involvement of these histone modifications in erythroid-specific developmental processes, including hemoglobin switching, chromatin condensation, and enucleation.Conclusions This review summarizes the current understanding of the role of histone modifications in erythropoiesis based on existing research, as a foundation for further research the mechanisms of epigenetic regulatory in erythropoiesis.

Microbiome, metabolome, and ionome profiling of cyst fluids reveals heterogeneity in pancreatic cystic neoplasms

Pancreatic cystic neoplasms (PCNs) carry variable malignant potential, requiring precise clinical management. However, the heterogeneity and progression of PCNs remain poorly understood. This study analyzed the microbiome, metabolome, and ionome profiles of cyst fluids from 188 patients, including 165 with PCNs and 23 with other cyst types, using PacBio full-length 16S/ITS sequencing, LC-MS/MS, and ICP-MS. Bioinformatic analyses were performed, and metabolic enzyme and endoplasmic reticulum (ER) stress-related gene expression were examined using the PAAD TCGA dataset. PCNs were classified into distinct histopathological subtypes, including mucinous cystic lesions (MCLs) and serous cystic lesions (SCLs). MCLs demonstrated lower microbial diversity compared to SCLs, indicating microbial instability. Streptococcus and Staphylococcus were identified as key taxa in intraductal papillary mucinous neoplasms (IPMNs) and mucinous cystic neoplasms (MCNs), respectively. MCLs exhibited metabolic shifts towards lipid metabolism, while IPMNs showed distinct metabolic profiles potentially reflecting inflammation-related metabolic reprogramming. Ionic diversity varied among subtypes, with MCLs showing reduced diversity and IPMNs presenting broader ionic profiles. Palmitic acid (PA), a metabolite linked to Streptococcus, may contribute to pro-inflammatory metabolic alterations in IPMN. Our preliminary experiments demonstrated that co-culturing Streptococcus orails (S. orails) with ASAN-PaCa cells promoted their proliferation, accompanied by an elevation of PA levels in the supernatant. This integrative microbiome-metabolome-ionome analysis highlights histopathological heterogeneity among PCNs. While mechanistic associations remain to be fully defined, mucinous lesions may be more susceptible to microbe-driven metabolic disruption, with Streptococcus-associated lipid alterations as a potential contributing factor.

HDAC9-Mediated Pyroptosis Promotes Orthodontically Induced Inflammatory Root Resorption

INTRODUCTION AND AIMS

Orthodontically induced inflammatory root resorption (OIIRR) is a common iatrogenic outcome of orthodontic treatment. Both epigenetic modifications and pyroptosis have demonstrated a certain role in OIIRR. This study aims to investigate whether epigenetic modifications regulate pyroptosis to be involved in OIIRR.

METHOD

Rat model of OIIRR was established, and the periodontal tissues were utilized for H&E staining, TRAP staining, immunofluorescence, transcriptome sequencing, and RT-qPCR analysis. Human periodontal ligament fibroblasts (hPDLFs) were overexpressed with HDAC9, treated with pyroptosis inhibitor, incubated with osteoclast, and then subjected to CUT&Tag sequencing.

RESULTS

Orthodontic force increased the distance of orthodontic tooth movement and the abundance of osteoclast. Transcriptome sequencing identified that Hdac9 was upregulated in the periodontal tissues of OIIRR rats compared to the control. Immunofluorescence revealed that HDAC9 was present in periodontal ligament fibroblasts, with reduced fluorescence of HDAC9 in OIIRR compared to the control. HDAC9 overexpression in hPDLFs induced pyroptosis and promoted osteoclast differentiation. These effects were reversed by pyroptosis inhibitor. CUT&Tag analysis showed that HDAC9 overexpression resulted in an enrichment of deacetylated genes on mitochondrial dysfunction-associated pathways. CUT&Tag-PCR analysis confirmed reduced H3K9ac enrichment on the mitochondrial dysfunction-associated genes VPS13D, AQP1, PEX2, CDK1, and PLEKHA1 after HDAC9 overexpression, and RT-qPCR analysis revealed a corresponding decrease in their respective expression levels. Accordingly, the ROS level was also increased by HDAC9 overexpression.

CONCLUSION

HDAC9-mediated histone deacetylation induces mitochondrial dysfunction and pyroptosis in hPDLFs, thereby promoting osteoclast differentiation and OIIRR progression.

CLINICAL RELEVANCE

This study reveals the regulatory mechanism of pyroptosis in OIIRR from the perspective of epigenetic modifications, providing new insights into the pathogenesis of OIIRR.

Histone Deacetylases (HDACs) Roles in Inflammation-mediated Diseases; Current Knowledge

The histone acetyl transferases (HATs) and histone deacetylases (HDACs), which are mostly recognized for their involvement in regulating chromatin remodeling via histone acetylation/deacetylation, have been shown to also change several non-histone proteins to regulate other cellular processes. Acetylation affects the activity or function of cytokine receptors, nuclear hormone receptors, intracellular signaling molecules, and transcription factors in connection to inflammation. Some small-molecule HDAC inhibitors are utilized as anticancer medications in clinical settings due to their capability to regulate cellular growth arrest, differentiation, and death. Here, we summarize our present knowledge of the innate and adaptive immunological pathways that classical HDAC enzymes control. The aim is to justify the targeted (or non-targeted) use of inhibitors against certain HDAC enzymes in inflammatory diseases such as arthritis, inflammatory bowel diseases (IBD), airways inflammation and neurological diseases.

Butyrate receptor HCAR2/GPR109A controls imiquimod-induced psoriasis-like skin inflammation

Psoriasis is a chronic inflammatory skin disorder characterized by aberrant keratinocyte proliferation and immune cell infiltration with upregulation of inflammatory cytokines. Here, we examined the contribution of HCAR2 encoding for the short-chain fatty acid receptor GPR109A. Human and mouse RNA sequencing public datasets reveal elevated HCAR2 gene expression in psoriatic as compared with healthy skin, both in keratinocytes and myeloid cells. Immunostaining and flow cytometry of imiquimod-induced psoriatic-like lesions in Hcar2-mRFP reporter mice showed increased GPR109A expression by keratinocytes and inflammatory cells. GPR109A-deficient mice demonstrated a more severe imiquimod-induced psoriasis-like response than wild-type mice, with exacerbated epidermal hyperplasia, dermal inflammatory cell infiltration, and increased inflammatory mediators myeloperoxidase, CXCL5, LCN2, interleukin (IL)-1β, IL-6, IL-23, and IL-17A. Conversely, topical administration of sodium butyrate reduced imiquimod-induced skin inflammation in wild-type mice, but not in GPR109A-deficient mice. Mechanistically, GPR109A agonist butyrate inhibits histone deacetylase 3, thus inhibiting IL-1β and the inflammatory IL-1β/IL-23/IL-17A axis in imiquimod-induced skin inflammation. Therefore, GPR109A may have a protective role in psoriasis pathogenesis, supporting a potential therapeutic benefit of sodium butyrate administration or other GPR109A agonists for treating psoriasis.

Chondrocyte fatty acid oxidation drives osteoarthritis via SOX9 degradation and epigenetic regulation

Osteoarthritis is the most prevalent age-related degenerative joint disease and is closely linked to obesity. However, the underlying mechanisms remain unclear. Here we show that altered lipid metabolism in chondrocytes, particularly enhanced fatty acid oxidation (FAO), contributes to osteoarthritis progression. Excessive FAO causes acetyl-CoA accumulation, thereby altering protein-acetylation profiles, where the core FAO enzyme HADHA is hyperacetylated and activated, reciprocally boosting FAO activity and exacerbating OA progression. Mechanistically, elevated FAO reduces AMPK activity, impairs SOX9 phosphorylation, and ultimately promotes its ubiquitination-mediated degradation. Additionally, acetyl-CoA orchestrates epigenetic modulation, affecting multiple cellular processes critical for osteoarthritis pathogenesis, including the transcriptional activation of MMP13 and ADAMTS7. Cartilage-targeted delivery of trimetazidine, an FAO inhibitor and AMPK activator, demonstrates superior efficacy in a mouse model of metabolism-associated post-traumatic osteoarthritis. These findings suggest that targeting chondrocyte-lipid metabolism may offer new therapeutic strategies for osteoarthritis.

Ketogenic diet attenuates microglia-mediated neuroinflammation by inhibiting NLRP3 inflammasome activation via HDAC3 inhibition to activate mitophagy in experimental autoimmune encephalomyelitis

The activation of microglia is an important cause of central nervous system (CNS) inflammatory cell infiltration and inflammatory demyelination in multiple sclerosis (MS). NOD-, LRR- and pyrin domain-containing protein 3 (NLRP3) inflammasome-mediated signaling plays a decisive role in microglial activation. Mitophagy is closely related to NLRP3-mediated neuroinflammation. Previous studies have shown that ketogenic diet (KD) suppresses microglial NLRP3 inflammasome activation and exerts mitophagy-stimulating effects, but the specific mechanism remains unclear. The current study examined the mechanism underlying the anti-inflammatory effect of KD on experimental autoimmune encephalomyelitis (EAE). Our data show that KD inhibited demyelination, increased co-staining of the translocase of the outer mitochondrial membrane (TOM20) and microtubule-associated protein 1A/1B-light chain 3 (LC3II), and decreased microglial NLRP3 inflammasome activation and histone deacetylase 3 (HDAC3) in the hippocampus of EAE mice. Further correlation analysis showed that the reduction of HDAC3 was negatively correlated with NLRP3 activation and positively correlated with the induction of mitophagy in KD-fed EAE mice. In BV2 microglial cells, we confirmed that the inhibition of HDAC3 promoted 5' adenosine monophosphate-activated protein kinase (AMPK)/mammalian target of rapamycin (mTOR)/unc-51-like autophagy activating kinase (ULK)1 and PTEN-induced putative kinase 1 (PINK1)/Parkin-meditated mitophagy, which led to the up-regulation of acetylated AMPK, acetylated ULK1 and acetylated Parkin, and subsequently reduced ROS accumulation and inhibited the activation of the NLRP3 inflammasome. In addition, treatment with 3-methyladenine (3-MA), a specific autophagy inhibitor, abolished the anti-inflammatory effect of HDAC3 inhibition in BV2 cells. The study illustrates that KD ameliorates EAE by reducing NLRP3-mediated inflammation in microglial cells via HDAC3 inhibition and enhancement of mitophagy-related protein acetylation.

Inflammatory signaling pathways in pancreatic β-cell: New insights into type 2 diabetes pathogenesis

Type 2 diabetes (T2D) is a complex metabolic disorder with a growing global prevalence, and there is a linking between inflammation in pancreatic β-cell and impaired glucose homeostasis which has emerged as a key player in the pathogenesis of T2D. Recent advances in research have provided new insights into various inflammatory signaling cascades in β-cell among which we focus on Toll-like Receptor 4 (TLR4), Nuclear Factor kappa B (NF-κB), Janus Kinase-Signal Transducer and Activator of Transcription (JAK/STAT), Platelet-Derived Growth Factor Receptor α (PDGFR-α), Stimulator of Interferon Genes (STING), and the death receptor TMEM219. TLR4 activation by pathogen- or damage-associated molecular patterns initiates NF-κB and mitogen-activated protein kinase (MAPK) cascades, promoting pro-inflammatory cytokine release and β-cell apoptosis. NF-κB acts as a central hub, integrating metabolic stress signals (e.g., glucolipotoxicity, ER stress) and amplifying inflammatory responses through crosstalk with JAK/STAT and STING pathways. Meanwhile, JAK/STAT signaling exhibits dual roles in β-cell survival and inflammation, influenced by cytokine milieu and feedback regulation. PDGFR-α, traditionally linked to β-cell proliferation, paradoxically contributes to pathological hyperplasia in obesity, while STING activation by cytosolic DNA triggers β-cell senescence and ferroptosis via IRF3/NF-κB. In this review, we synthesize recent advancements of these inflammatory signaling pathways in β-cells, and current therapeutic strategies targeting TLR4/NF-κB inhibitors, JAK/STAT modulators, STING antagonists, and the death receptor TMEM219 are discussed, alongside challenges in pathway specificity and clinical translation. Understanding these inflammatory signaling pathways and their interactions in pancreatic β-cell is essential for the development of novel therapeutic strategies to prevent or treat T2D.

Low-dose exposure to microplastics retards meiotic maturation via HDAC3 insufficiency

Microplastics (MPs) are considered one of the main causes of male and female infertility. However, the reproductive toxicity and its related mechanisms are currently understood primarily through animal models with acute exposure to MPs. In this study, we demonstrate that low-dose exposure to polystyrene microplastics (PSMPs) leads to severely abnormal reproduction in females, manifested by oocyte meiotic maturation defect. Mechanistically, PSMPs exposure induce the overactivation of cell metabolism pathways, insufficient HDACs, and H4K16 hyperacetylation in oocytes both in vivo and in vitro. When an HDAC3 inhibitor is added, the oocyte maturation defect, overactivation of cell metabolism pathways, and H4K16 hyperacetylation are recapitulated. Conversely, the overexpression of HDAC3 can rescue the defects in meiotic maturation induced by PSMPs. Our observations suggest a direct link between the maturation defects caused by PSMPs and HDAC3 insufficiency. Thus, we propose potential treatments to address the meiotic maturation defect of oocytes in women highly exposed to MPs by activating or supplying HDAC3.

Mitochondrial dynamics and metabolism in macrophages for cardiovascular disease: A review

BACKGROUND

Mitochondria regulate macrophage function, affecting cardiovascular diseases like atherosclerosis and heart failure. Their dynamics interact with macrophage cell death mechanisms, including apoptosis and necroptosis.

PURPOSE

This review explores how mitochondrial dynamics and metabolism influence macrophage inflammation and cell death in CVDs, highlighting therapeutic targets for enhancing macrophage resilience and reducing CVD pathology, while examining molecular pathways and pharmacological agents involved.

STUDY DESIGN

This is a narrative review that integrates findings from various studies on mitochondrial dynamics and metabolism in macrophages, their interactions with the endoplasmic reticulum (ER) and Golgi apparatus, and their implications for CVDs. The review also considers the potential therapeutic effects of pharmacological agents on these pathways.

METHODS

The review utilizes a comprehensive literature search to identify relevant studies on mitochondrial dynamics and metabolism in macrophages, their role in CVDs, and the effects of pharmacological agents on these pathways. The selected studies are analyzed and synthesized to provide insights into the complex relationships between mitochondria, the ER, and Golgi apparatus, and their implications for macrophage function and fate.

RESULTS

The review reveals that mitochondrial metabolism intertwines with cellular architecture and function, particularly through its intricate interactions with the ER and Golgi apparatus. Mitochondrial-associated membranes (MAMs) facilitate Ca2+ transfer from the ER to mitochondria, maintaining mitochondrial homeostasis during ER stress. The Golgi apparatus transports proteins crucial for inflammatory signaling, contributing to immune responses. Inflammation-induced metabolic reprogramming in macrophages, characterized by a shift from oxidative phosphorylation to glycolysis, underscores the multifaceted role of mitochondrial metabolism in regulating immune cell polarization and inflammatory outcomes. Notably, mitochondrial dysfunction, marked by heightened reactive oxygen species generation, fuels inflammatory cascades and promotes cell death, exacerbating CVD pathology. However, pharmacological agents such as Metformin, Nitazoxanide, and Galanin emerge as potential therapeutic modulators of these pathways, offering avenues for mitigating CVD progression.

CONCLUSION

This review highlights mitochondrial dynamics and metabolism in macrophage inflammation and cell death in CVDs, suggesting therapeutic targets to improve macrophage resilience and reduce pathology, with new pharmacological agents offering treatment opportunities.

Acetylation and deacetylation dynamics in stress response to cancer and infections

In response to stress stimuli, cells have evolved various mechanisms to integrate internal and external signals to achieve dynamic homeostasis. Lysine acetyltransferase (KATs) and deacetyltransferase (KDACs) are the key modulators of epigenetic modifications, enabling cells to modulate cellular responses through the acetylation and deacetylation of both histone and nonhistone proteins. Understanding the signaling pathways involved in cellular stress response, along with the roles of KATs and KDACs may pave the way for the development of novel therapeutic strategies. This review discusses the molecular mechanisms of acetylation and deacetylation in stress responses related to tumorigenesis, viral and bacterial infections. In tumorigenesis section, we focused on the tumor cells' intrinsic and external molecules and signaling pathways regulated by acetylation and deacetylation modification. In viral and bacterial infections, we summarized the update research on acetylation and deacetylation modification in viral and bacterial infections, which systematical introduction on this topic is not too much. Additionally, we provide an overview of current therapeutic interventions and clinical trials involving KAT and KDAC inhibitors in the treatment of cancer, as well as viral and bacterial infection-related diseases.

Histone deacetylases and their inhibitors in kidney diseases

Histone deacetylases (HDACs) have emerged as key regulators in the pathogenesis of various kidney diseases. This review explores recent advancements in HDAC research, focusing on their role in kidney development and their critical involvement in the progression of chronic kidney disease (CKD), acute kidney injury (AKI), autosomal dominant polycystic kidney disease (ADPKD), and diabetic kidney disease (DKD). It also discusses the therapeutic potential of HDAC inhibitors in treating these conditions. Various HDAC inhibitors have shown promise by targeting specific HDAC isoforms and modulating a range of biological pathways. Their protective effects include modulation of apoptosis, autophagy, inflammation, and fibrosis, underscoring their broad therapeutic potential for kidney diseases. However, further research is essential to improve the selectivity of HDAC inhibitors, minimize toxicity, overcome drug resistance, and enhance their pharmacokinetic properties. This review offers insights to guide future research and prevention strategies for kidney disease management.

Acetylation suppresses breast cancer progression by sustaining CLYBL stability

BACKGROUND

The incidence of breast cancer remains high and it remains the leading cause of cancer-related deaths in women. A better understanding of the molecular mechanisms of breast cancer and identifying novel biomarkers will help improve therapeutic strategies. Citrate lyase beta like (CLYBL) is expressed at low levels in breast cancer tissues and is associated with low patient survival rates. In this study, we explored the regulatory mechanisms of CLYBL and its acetylation in breast cancer.

METHODS

CLYBL expression patterns in breast cancer were assessed using a breast cancer tissue microarray, immunohistochemistry, and publicly available datasets. The acetylation patterns of CLYBL and the related regulatory functions were detected by high resolution mass spectrometry, immunoprecipitation assays, and western blot analysis. The potential effects of CLYBL and its acetylation on breast cancer were determined using both in vitro and in vivo assays.

RESULTS

CLYBL was expressed at lower levels in breast cancer samples compared with normal tissues. This low CLYBL expression was associated with poor patient survival rates. Overexpressing CLYBL could inhibit breast cancer and reduce NRF2 pathway-mediated antioxidants. We identified two acetylated lysine sites in CLYBL, K57 and K82, using acetylated peptide affinity enrichment and high-resolution mass spectrometry. Our results suggest that K82 is the main acetylation site. Further work showed that the p300/CBP associated factor (PCAF) and histone deacetylase 3 (HDAC3) as the CLYBL acetyltransferase and deacetylase, respectively. Additionally, CLYBL acetylation facilitates its own protein stability by reducing it affinity for ubiquitin, thus enhancing the anti-breast cancer effects.

CONCLUSION

We revealed the role of CLYBL overexpression and its acetylation in breast cancer. Our study suggests that CLYBL is a potential molecular target for breast cancer therapy.

Integrated network pharmacological analysis and multi-omics techniques to reveal the mechanism of polydatin in the treatment of silicosis via gut-lung axis

Silicosis is a pulmonary disease characterized by inflammation and progressive fibrosis. Previous studies have shown that polydatin (PD) has potential biological activity in key signaling pathways regulating inflammation and apoptosis. To investigate the effect of PD on rats with silicosis, this study used network pharmacology and molecular docking methods to determine the target of PD treatment for silicosis. The therapeutic effect of PD on silicosis was confirmed by measuring the lung injury score, hydroxyproline content, and mRNA expression levels of key targets. In addition, metagenomic sequencing and gas chromatography-mass spectrometry were used to determine the gut microbiota composition and targeted metabolomics analysis, respectively. The results showed that PD could inhibit the expression of inflammation-related indexes and apoptosis-related indexes at protein and mRNA levels. PD also regulates the diversity of the intestinal flora and the content of short-chain fatty acids. In conclusion, the current data suggest that PD has a protective effect against silica-induced lung injury and plays a protective role in regulating intestinal flora diversity and short-chain fatty acid levels through the gut-lung axis.

HADHA promotes apoptosis and inflammatory response in bovine endometrial epithelial cells by regulating transcription and metabolism

Endometritis in dairy cows significantly impacts their reproductive performance. However, its underlying mechanisms remain unclear. Hydroxyacyl-CoA dehydrogenase trifunctional multienzyme complex subunit-alpha (HADHA) is known to regulate the occurrence of various diseases, but its role in bovine endometritis is poorly understood. In the present study, an in vitro bovine endometrial epithelial cells (BEECs) inflammation model was constructed to explore the effects of HADHA on inflammation, proliferation, and apoptosis. Functional analyses based on HADHA interference and overexpression revealed that it positively regulated the expression of IL-6, IL-8, and IL-1β in lipopolysaccharide (LPS)-induced BEECs, enhancing reactive oxygen species (ROS) production and promoting inflammation. Concurrently, HADHA decreased the expression of PCNA, CDK2, and CDK4, inhibited mitotic transition of BEECs from S to G2 phase, and negatively regulated BEEC proliferation. It also increased BAX and Caspase-3 expression while decreasing BCL2 expression, hence promoting BEECs apoptosis. Transcriptomic and metabolomic analyses indicated that HADHA modulated inflammation in BEECs by affecting pathways such as the TGF-beta signaling pathway, fatty acid metabolism, and p53 signaling. These findings provide novel insights into HADHA's role in bovine endometritis and reveal future research directions on its regulatory mechanisms.

The shared mechanism of barrier dysfunction in ulcerative colitis and Alzheimer's disease: DDIT4/IL1β neutrophil extracellular traps drive macrophages-mediated phagocytosis

Ulcerative colitis (UC) and Alzheimer's disease (AD) share a common etiology as inflammatory diseases characterized by barrier deterioration. The aim of this study is to elucidate how neutrophil extracellular traps (NETs), serving as a comorbid etiological factor, can trigger the dysfunction in both the intestinal barrier and blood-brain barrier (BBB). Integrated bioinformatics analysis revealed 14 overlapped NETs-related differential expressed genes in UC and AD, which strongly featured barrier dysfunction. The following verification experiments identified enriched NETs, as well as damaged intestinal epithelium and BBB permeability, in the colon and prefrontal cortex of colitis mice and APP/PS1 mice. By employing pharmacological interventions (Cl-amidine and Disulfiram), we disrupted the formation of NETs and discovered significantly restored barrier integrity and attenuated inflammation. Further enrichment and correlation analysis indicated, for the first time, DDIT4/IL-1β NETs might drive macrophage-mediated phagocytosis to induce barrier dysfunction in UC and AD. Our findings originally established the peripheral-central inflammation interactions of UC and AD from the perspective of NETs, highlighting the potential valuable roles in gut-brain interactions and future clinic translational therapeutics.

New insights into the relationship of mitochondrial metabolism and atherosclerosis

Atherosclerotic cardiovascular and cerebrovascular diseases are the number one killer of human health. In view of the important role of mitochondria in the formation and evolution of atherosclerosis, our manuscript aims to comprehensively elaborate the relationship between mitochondria and the formation and evolution of atherosclerosis from the aspects of mitochondrial dynamics, mitochondria-organelle interaction (communication), mitochondria and cell death, mitochondria and vascular smooth muscle cell phenotypic switch, etc., which is combined with genome, transcriptome and proteome, in order to provide new ideas for the pathogenesis of atherosclerosis and the diagnosis and treatment of related diseases.

An sp2 Carbon-Conjugated Covalent Organic Framework for Fusing Lipid Droplets and Engineered Macrophage Therapy

Engineered immune cell therapy has proven to be a transformative cancer treatment despite the challenges of its prohibitive costs and manufacturing complexity. In this study, we propose a concise "lipid droplet fusion" strategy for engineering macrophages. Because of the integration of hydrophobic alkyl chains and π-conjugated structures, the mildly synthesized sp2C-conjugated covalent organic framework (COF) UM-101 induced lipid droplet fusion and metabolic reprogramming of macrophages, thus promoting their antitumor classical activation. Intravenous injection of UM-101-engineered macrophages effectively inhibited tumor progression. These results represent the first report of room-temperature synthesis of sp2C-conjugated COFs for engineered immune cell therapy, providing a new perspective for the development of therapeutic immune cells via organelle manipulation.

Interleukin 8 exacerbates age-related hearing loss through regulating perivascular-resident macrophage-like melanocytes viability and the permeability of the endothelial cells

The etiology and mechanism causing Age-related hearing loss (ARHL) are not understood. This study aimed to investigate the molecular mechanism of interleukin 8 (IL-8) associated with ARHL. Sera content of IL-8 was significantly higher in patients with ARHL than normal volunteers and had a positive association with disease severity of ARHL. Human IL-8 (hIL-8) could exacerbate the progressive ARHL with time increase and promoted apoptosis of hair cells in cochlea. As the important component in maintaining the integrity of the blood-labyrinth barrier (BLB) and hearing function, cell viability of perivascular-resident macrophage-like melanocytes (PVM/Ms) was restrained while apoptosis of PVM/Ms was enhanced in the presence of hIL-8. Using a cell culture-based in vitro model, the permeability of the endothelial cells (ECs) monolayer increased markedly in the presence of IL-8-treated PVM/Ms or PVM/Ms-derived from LV5-hIL-8 mice as compared with the presence of PVM/Ms-derived from wild type (WT) mice or 12-months WT mice. Mechanistically, IL-8 exposure enhanced the expression of histone deacetylase 3 (HDAC3) in PVM/Ms and HDAC3 inhibitor significantly blocked the permeability of the ECs in the presence of IL-8-treated PVM/Ms. Besides, HDAC3 inhibitor had a protective effect on hIL-8-launched ARHL in mice. Collectively, the elevated of serum IL-8 in ARHL patients activated the activity of HDAC3 in PVM/Ms, subsequently increased the permeability of the ECs, resulting in the impairments of the BLB and hair cells in cochlea. Possibly, IL-8 could be used in the diagnosis of ARHL and these findings might help to identify the clinical therapeutic direction for ARHL.

Identification and Characterization of Genes Associated with Intestinal Ischemia-Reperfusion Injury and Oxidative Stress: A Bioinformatics and Experimental Approach Integrating High-Throughput Sequencing, Machine Learning, and Validation

Purpose

Intestinal ischemia-reperfusion injury (IIRI) occurs as a result of temporary blood flow interruption, leading to tissue damage upon reperfusion. Oxidative stress plays a critical role in this process, instigating inflammation and cell death. Identifying and characterizing genes associated with the oxidative stress response can offer valuable insights into potential therapeutic targets for managing IIRI.

Patients and Methods

The IIRI dataset was sourced from the NCBI Gene Expression Omnibus Database (GEO), while oxidative stress genes were obtained from the Genecards database. Following the acquisition of differentially expressed genes in IIRI, they were cross-linked with oxidative stress genes to yield IIRI oxidative stress related genes (IOSRGs). The least absolute shrinkage and selection operator, as well as the support vector machine with random forest algorithm, were utilized for machine learning. Subsequently, the PPI network was established, and the Degree and MNC algorithms of the Cytohuba plugin were integrated with the genes obtained through the machine learning algorithms to identify hub IOSRGs (HIOSRGs). A mouse IIRI model and ROC curve were employed to verify the accuracy of HIOSRGs. Finally, siRNA was utilized to suppress the expression of HDAC3 in Caco2 cells, and the changes in oxidative stress levels before and after hypoxia-reoxygenation in Caco2 cells were observed.

Results

A total of 277 OSRGs and 4 HIOSRGs were obtained. Concurrently, in vivo experimental results of IIRI in C57BL/6 mice, and the establishment of ROC curves, reflected the accuracy and specificity of HIOSRGs. The knockdown of HDAC3 in Caco2 cells resulted in increased oxidative stress levels before and after hypoxia-reoxygenation, underscoring the significant role of HDAC3 in IIRI.

Conclusion

This study elucidates the interplay between oxidative stress genes and IIRI, offering novel insights into the potential pathogenesis of IIRI and medical interventions for IIRI.

HDAC10 switches NLRP3 modification from acetylation to ubiquitination and attenuates acute inflammatory diseases

BACKGROUND

The NOD-like receptor protein (NLRP)3 inflammasome is at the signaling hub center to instigate inflammation in response to pathogen infection or oxidative stress, and its tight control is pivotal for immune defense against infection while avoiding parallel intensive inflammatory tissue injury. Acetylation of NLRP3 is critical for the full activation of NLRP3 inflammasome, while the precise regulation of the acetylation and deacetylation circuit of NLRP3 protein remained to be fully understood.

METHODS

The interaction between histone deacetylase 10 (HDAC10) and NLRP3 was detected by immunoprecipitation and western blot in the HDAC10 and NLRP3 overexpressing cells. The role of HDAC10 in NLRP3 inflammasome activation was measured by immunofluorescence, real-time PCR and immunoblotting assay in peritoneal macrophages and bone marrow-derived macrophages after the stimulation with LPS and ATP. To investigate the role of HDAC10 in NLRP3-involved inflammatory diseases, the Hdac10 knockout (Hdac10-/-) mice were used to construct the LPS-induced acute endotoxemia model and folic acid-induced acute tubular necrosis model. Tissue injury level was analyzed by hematoxylin and eosin staining, and the serum level of IL-1β was measured by enzyme-linked immunosorbent assay (ELISA). The conservative analysis and immunoprecipitation assay were performed to screen the precise catalytic site regulated by HDAC10 responsible for the switching from the acetylation to ubiquitination of NLRP3.

RESULTS

Here we demonstrated that HDAC10 directly interacted with NLRP3 and induced the deacetylation of NLRP3, thus leading to the inhibition of NLRP3 inflammasome and alleviation of NLRP3 inflammasome-mediated acute inflammatory injury. Further investigation demonstrated that HDAC10 directly induced the deacetylation of NLRP3 at K496 residue, thus switching NLRP3 acetylation to the ubiquitination modification, resulting in the proteasomal degradation of NLRP3 protein. Thus, this study identified HDAC10 as a new eraser for NLRP3 acetylation, and HDAC10 attenuated NLRP3 inflammasome involved acute inflammation via directly deacetylating NLRP3.

CONCLUSIONS

This study indicated that HDAC10 switched NLRP3 modification from acetylation to ubiquitination and attenuated acute inflammatory diseases, thus it provided a potential therapeutic strategy for NLRP3 inflammasome-associated diseases by targeting HDAC10.

Bifidobacterium longum Metabolite Indole-3-Carboxaldehyde Blocks HDAC3 and Inhibits Macrophage NLRP3 Inflammasome Activation in Intestinal Ischemia/Reperfusion Injury

Indole-3-carboxaldehyde (3-IAld), a tryptophan metabolite derived from gut microbiota, has been reported to protect the intestine against radiation injury. This study aimed to clarify the role of Bifidobacterium longum (B. longum) and its metabolite indole-3-carboxaldehyde (3-IAld) in the pathophysiology of intestinal ischemia/reperfusion (II/R) injury. Superior mesenteric artery occlusion and reperfusion were performed to establish II/R mice, and pathological injury in II/R mice was evaluated. II/R mice showed impaired gut microbiota diversity and reduced abundance of B. longum in the intestines. Transplantation of B. longum mitigated II/R injury by protecting the integrity of the intestinal barrier and reducing inflammatory response. The 3-IAld level increased after transplantation of B. longum, and 3-IAld treatment inhibited the inflammatory response of bone marrow-derived macrophages (BMDM). Histone deacetylase 3 (HDAC3) was a target of 3-IAld, and HDAC3 was translocated to mitochondria to promote mitochondrial fatty acid oxidation (FAO) during macrophage inflammasome formation. HDAC3 overexpression promoted the formation of macrophage inflammasomes in intestinal tissues. Overall, this study confirmed the beneficial effects of B. longum in combating II/R injury through HDAC3-mediated control of mitochondrial FAO and macrophage inflammasome formation via 3-IAld.

Role of the histone deacetylase family in lipid metabolism: Structural specificity and functional diversity

Lipids play crucial roles in signal transduction. Lipid metabolism is associated with several transcriptional regulators, including peroxisome proliferator activated receptor γ, sterol regulatory element-binding protein 1, and acetyl-CoA carboxylase. In recent years, increasing evidence has suggested that members of the histone deacetylase (HDAC) family play key roles in lipid metabolism. However, the mechanisms by which each member of this family regulates lipid metabolism remain unclear. This review discusses the latest research on the roles played by HDACs in fat metabolism. The role of HDACs in obesity, diabetes, and atherosclerosis has also been discussed. In addition, the interaction of HDACs with the gut microbiome and circadian rhythm has been reviewed, and the future development trend in HDACs has been predicted, which may potentiate therapeutic application of targeted HDACs in related metabolic diseases.

Advances in research on the relationship between mitochondrial function and colorectal cancer: a bibliometric study from 2013 to 2023

The study provides a thorough examination of literature from 2013 to 2023, delving into the intricate relationship between mitochondrial function and colorectal cancer (CRC). It offers a concise overview of the current landscape and emerging trends in this rapidly evolving research area. The findings indicate a consistent rise in annual publications, reflecting growing interest and significant potential in the field. China emerges as the leading contributor, followed by the United States and India. However, despite China's dominance in output, its average citation rate is lower than that of the US, which leads in citations per publication, highlighting a noticeable disparity. In the realm of research institutions, Shanghai Jiao Tong University and China Medical University are identified as major contributors, yet the potential for inter-institutional collaboration remains largely untapped, suggesting avenues for future synergy. Internationally, China-US collaborations are particularly robust, fostering cross-border knowledge exchange. Hyun Jin Won and Li Wei are recognized as prolific authors, while Ahmedin Jemal is an influential co-cited scholar, noted for his seminal contributions. Keyword analysis reveals research focus areas, such as the complex CRC tumor microenvironment, molecular mechanisms of oxidative stress, and key multidrug resistance pathways. It also highlights the promising potential of mitochondria-targeted therapies and nanomolecular technologies in clinical practice, signaling their growing significance in addressing complex health challenges. The study underscores the imperative to validate complex mitochondrial mechanisms and signaling pathways in CRC, with a particular emphasis on translating these insights into drug targets for clinical trials. Advancing this research is expected to refine and enhance CRC treatment strategies. Additionally, it highlights the urgency of validating mitochondrial complexities in CRC, advocating for collaborative efforts to link these mechanisms with tailored therapeutic interventions for clinical testing. This integrated approach promises significant advancements in developing effective, targeted CRC treatments, ultimately improving patient outcomes.

Mass Spectrometry Probe Combined with Machine Learning to Capture the Relationship between Metabolites and Mitochondrial Complex Activity at the Whole-Cell Level

Mitochondrial complex activity controls a multitude of physiological processes by regulating the cellular metabolism. Current methods for evaluating mitochondrial complex activity mainly focus on single metabolic reactions within mitochondria. These methods often require fresh samples in large quantities for mitochondria purification or intact mitochondrial membranes for real-time monitoring. Confronting these limitations, we shifted the analytical perspective toward interactive metabolic networks at the whole-cell level to reflect mitochondrial complex activity. To this end, we compiled a panel of mitochondrial respiratory chain-mapped metabolites (MRCMs), whose perturbations theoretically provide an overall reflection on mitochondrial complex activity. By introducing N-dimethyl-p-phenylenediamine and N-methyl-p-phenylenediamine as a pair of mass spectrometry probes, an ultraperformance liquid chromatography-tandem mass spectrometry method with high sensitivity (LLOQ as low as 0.2 fmol) was developed to obtain accurate quantitative data of MRCMs. Machine learning was then combined to capture the relationship between MRCMs and mitochondrial complex activity. Using Complex I as a proof-of-concept, we identified NADH, alanine, and phosphoenolpyruvate as metabolites associated with Complex I activity based on the whole-cell level. The effectiveness of using their concentrations to reflect Complex I activity was further validated in external data sets. Hence, by capturing the relationship between metabolites and mitochondrial complex activity at the whole-cell level, this study explores a novel analytical paradigm for the interrogation of mitochondrial complex activity, offering a favorable complement to existing methods particularly when sample quantities, type, and treatment timeliness pose challenges. More importantly, it shifts the focus from individual metabolic reactions within mitochondria to a more comprehensive view of an interactive metabolic network, which should serve as a promising direction for future research into the functional architecture between mitochondrial complexes and metabolites.

The role of macrophage and adipocyte mitochondrial dysfunction in the pathogenesis of obesity

Obesity has emerged as a prominent global public health concern, leading to the development of numerous metabolic disorders such as cardiovascular diseases, type-2 diabetes mellitus (T2DM), sleep apnea and several system diseases. It is widely recognized that obesity is characterized by a state of inflammation, with immune cells-particularly macrophages-playing a significant role in its pathogenesis through the production of inflammatory cytokines and activation of corresponding pathways. In addition to their immune functions, macrophages have also been implicated in lipogenesis. Additionally, the mitochondrial disorders existed in macrophages commonly, leading to decreased heat production. Meantime, adipocytes have mitochondrial dysfunction and damage which affect thermogenesis and insulin resistance. Therefore, enhancing our comprehension of the role of macrophages and mitochondrial dysfunction in both macrophages and adipose tissue will facilitate the identification of potential therapeutic targets for addressing this condition.

Classical swine fever virus inhibits serine metabolism-mediated antiviral immunity by deacetylating modified PHGDH

Classical swine fever virus (CSFV), an obligate intracellular pathogen, hijacks cellular metabolism to evade immune surveillance and facilitate its replication. The precise mechanisms by which CSFV modulates immune metabolism remain largely unknown. Our study reveals that CSFV infection disrupts serine metabolism, which plays a crucial role in antiviral immunity. Notably, we discovered that CSFV infection leads to the deacetylation of PHGDH, a key enzyme in serine metabolism, resulting in autophagic degradation. This deacetylation impairs PHGDH's enzymatic activity, reduces serine biosynthesis, weakens innate immunity, and promotes viral proliferation. Molecularly, CSFV infection induces the association of HDAC3 with PHGDH, leading to deacetylation at the K364 site. This modification attracts the E3 ubiquitin ligase RNF125, which facilitates the addition of K63-linked ubiquitin chains to PHGDH-K364R. Subsequently, PHGDH is targeted for lysosomal degradation by p62 and NDP52. Furthermore, the deacetylation of PHGDH disrupts its interaction with the NAD+ substrate, destabilizing the PHGDH-NAD complex, impeding the active site, and thereby inhibiting de novo serine synthesis. Additionally, our research indicates that deacetylated PHGDH suppresses the mitochondria-MAVS-IRF3 pathway through its regulatory effect on serine metabolism, leading to decreased IFN-β production and enhanced viral replication. Overall, our findings elucidate the complex interplay between CSFV and serine metabolism, revealing a novel aspect of viral immune evasion through the lens of immune metabolism.

IMPORTANCE

Classical swine fever (CSF) seriously restricts the healthy development of China's aquaculture industry, and the unclear pathogenic mechanism and pathogenesis of classical swine fever virus (CSFV) are the main obstacle to CSF prevention, control, and purification. Therefore, it is of great significance to explore the molecular mechanism of CSFV and host interplay, to search for the key signaling pathways and target molecules in the host that regulate the replication of CSFV infection, and to elucidate the mechanism of action of host immune dysfunction and immune escape due to CSFV infection for the development of novel CSFV vaccines and drugs. This study reveals the mechanism of serine metabolizing enzyme post-translational modifications and antiviral signaling proteins in the replication of CSFV and enriches the knowledge of CSFV infection and immune metabolism.

Overview of class I HDAC modulators: Inhibitors and degraders

Class I histone deacetylases (HDACs) are closely associated with the development of a diverse array of diseases, including cancer, neurodegenerative disorders, HIV, and inflammatory diseases. Considering the essential roles in tumorigenesis, class I HDACs have emerged as highly desirable targets for therapeutic strategies, particularly in the field of anticancer drug development. However, the conventional class I HDAC inhibitors faced several challenges such as acquired resistance, inherent toxicities, and limited efficacy in inhibiting non-enzymatic functions of HDAC. To address these problems, novel strategies have emerged, including the development of class I HDAC dual-acting inhibitors, targeted protein degradation (TPD) technologies such as PROTACs, molecular glues, and HyT degraders, as well as covalent inhibitors. This review provides a comprehensive overview of class I HDAC enzymes and inhibitors, by initially introducing their structure and biological roles. Subsequently, we focus on the recent advancements of class I HDAC modulators, including isoform-selective class I inhibitors, dual-target inhibitors, TPDs, and covalent inhibitors, from the perspectives of rational design principles, pharmacodynamics, pharmacokinetics, and clinical progress. Finally, we also provide the challenges and outlines future prospects in the realm of class I HDAC-targeted drug discovery for cancer therapeutics.

Neuronal HIPK2-HDAC3 axis regulates mitochondrial fragmentation to participate in stroke injury and post-stroke anxiety like behavior

Post-stroke anxiety (PSA) seriously affects the prognosis of patients, which is an urgent clinical problem to be addressed. However, the pathological mechanism of PSA is largely unclear. Here, we found that neuronal HIPK2 expression was upregulated in the ischemic lesion after stroke. The upregulation of HIPK2 promotes Drp1 oligomerization through the HDAC3-dependent pathway, leading to excessive mitochondrial damage. This subsequently triggers the release of cellular cytokines such as IL-18 from neurons under ischemic stress. Microglia are capable of responding to IL-18, which promotes their activation and enhances their phagocytosis, ultimately resulting in the loss of synapses and neurons, thereby exacerbating the pathological progression of PSA. HIPK2 knockdown or inhibition suppresses excessive pruning of neuronal synapses by activated microglia in the contralateral vCA1 region to compromise inactivated anxiolytic pBLA-vCA1Calb1+ circuit, relieving anxiety-like behavior after stroke. Furthermore, we discovered that early remimazolam administration can remodel HIPK2-HDAC3 axis, ameliorating the progression of PSA. In conclusion, our study revealed that the neuronal HIPK2-HDAC3 axis in the ischemic focus regulates mitochondrial fragmentation to balance inflammation stress reservoir to participate in anxiety susceptibility after stroke.

Gasdermin D-mediated metabolic crosstalk promotes tissue repair

The establishment of an early pro-regenerative niche is crucial for tissue regeneration1,2. Gasdermin D (GSDMD)-dependent pyroptosis accounts for the release of inflammatory cytokines upon various insults3-5. However, little is known about its role in tissue regeneration followed by homeostatic maintenance. Here we show that macrophage GSDMD deficiency delays tissue recovery but has little effect on the local inflammatory milieu or the lytic pyroptosis process. Profiling of the metabolite secretome of hyperactivated macrophages revealed a non-canonical metabolite-secreting function of GSDMD. We further identified 11,12-epoxyeicosatrienoic acid (11,12-EET) as a bioactive, pro-healing oxylipin that is secreted from hyperactive macrophages in a GSDMD-dependent manner. Accumulation of 11,12-EET by direct supplementation or deletion of Ephx2, which encodes a 11,12-EET-hydrolytic enzyme, accelerated muscle regeneration. We further demonstrated that EPHX2 accumulated within aged muscle, and that consecutive 11,12-EET treatment rejuvenated aged muscle. Mechanistically, 11,12-EET amplifies fibroblast growth factor signalling by modulating liquid-liquid phase separation of fibroblast growth factors, thereby boosting the activation and proliferation of muscle stem cells. These data depict a GSDMD-guided metabolite crosstalk between macrophages and muscle stem cells that governs the repair process, which offers insights with therapeutic implications for the regeneration of injured or aged tissues.

The involvement of HDAC3 in the pathogenesis of lung injury and pulmonary fibrosis

Acute lung injury (ALI) and its severe counterpart, acute respiratory distress syndrome (ARDS), are critical respiratory conditions with high mortality rates due primarily to acute and intense pulmonary inflammation. Despite significant research advances, effective pharmacological treatments for ALI and ARDS remain unavailable, highlighting an urgent need for therapeutic innovation. Notably, idiopathic pulmonary fibrosis (IPF) is a chronic, progressive disease characterized by the irreversible progression of fibrosis, which is initiated by repeated damage to the alveolar epithelium and leads to excessive extracellular matrix deposition. This condition is further complicated by dysregulated tissue repair and fibroblast dysfunction, exacerbating tissue remodeling processes and promoting progression to terminal pulmonary fibrosis. Similar to that noted for ALI and ARDS, treatment options for IPF are currently limited, with no specific drug therapy providing a cure. Histone deacetylase 3 (HDAC3), a notable member of the HDAC family with four splice variants (HD3α, -β, -γ, and -δ), plays multiple roles. HDAC3 regulates gene transcription through histone acetylation and adjusts nonhistone proteins posttranslationally, affecting certain mitochondrial and cytoplasmic proteins. Given its unique structure, HDAC3 impacts various physiological processes, such as inflammation, apoptosis, mitochondrial homeostasis, and macrophage polarization. This article explores the intricate role of HDAC3 in ALI/ARDS and IPF and evaluates its therapeutic potential the treatment of these severe pulmonary conditions.

HADHA promotes glioma progression by accelerating MDM2-mediated p53 ubiquitination

Glioma represents a notoriously aggressive and malignant tumor that targets the central nervous system, with a poor prognosis for patients. In this research, we set out to examine the role of hydroxyacyl-CoA dehydrogenase trifunctional multienzyme complex subunit alpha (HADHA) in glioma, its clinical significance, as well as its potential biological mechanisms. In this study, we used immunohistochemistry staining to assess the expression level of HADHA in glioma tissues. We also evaluated the correlation between HADHA expression and patient survival using the Kaplan-Meier method. To determine the role of HADHA in glioma cells, we conducted loss-of-function assays in vitro and in vivo. Additionally, we utilized co-immunoprecipitation and protein stability assays to investigate the potential mechanisms involving HADHA, MDM2, and p53 in glioma. Our research findings indicate that gliomas exhibit high levels of HADHA. Clinically, high expression of HADHA suggests an increased risk of malignant tumors, recurrence, and reduced survival rates. Functionally, knocking down HADHA can lead to decreased proliferation, enhanced apoptosis, and inhibited migration of glioma cells. Mechanistically, HADHA accelerates MDM2-mediated p53 ubiquitination through interaction with MDM2. Consistently, MDM2 knockdown or overexpression of p53 can attenuate the promoting effect of HADHA overexpression on the malignant progression of glioma. We have discovered a novel role of HADHA in promoting MDM2-mediated p53 ubiquitination, which contributes to the progression of glioma. This finding provides a new perspective to understand the pathogenesis of glioma and offers a potential target for developing innovative therapeutic strategies.

Lactucopicrin promotes fatty acid β-oxidation and attenuates lipid accumulation through adenosine monophosphate-activated protein kinase activation in free fatty acid-induced human hepatoblastoma cancer cells

With its annually increasing prevalence, non-alcoholic fatty liver disease (NAFLD) has become a serious threat to people's life and health. After a preliminary research, we found that Lactucopicrin has pharmacological effects, such as lowering blood lipids and protecting the liver. Further research showed its significant activation for fatty acid β-oxidase hydroxyacyl-coenzyme A (CoA) dehydrogenase trifunctional multienzyme complex subunit alpha (HADHA), so we hypothesized that Lactucopicrin could ameliorate lipid accumulation in hepatocytes by promoting fatty acid β-oxidation. In this study, free fatty acid (FFA)-induced human hepatoblastoma cancer cells (HepG2) were used to establish an in vitro NAFLD model to investigate the molecular basis of Lactucopicrin in regulating lipid metabolism. Staining with Oil red O and measurements of triglyceride (TG) content, fatty acid β-oxidase (FaβO) activity, reactive oxygen species (ROS) content, mitochondrial membrane potential, and adenosine triphosphate (ATP) content were used to assess the extent to which Lactucopicrin ameliorates lipid accumulation and promotes fatty acid β-oxidation. Quantitative real-time polymerase chain reaction (qRT-PCR) and Western blot methods were used to explore the regulatory effects of Lactucopicrin on factors related to fatty acid β-oxidation. Results showed that Lactucopicrin downregulated phosphorylated mammalian target of rapamycin (P-mTOR) by activating the adenosine monophosphate-activated protein kinase (AMPK) pathway and upregulated the messenger RNA (mRNA) and protein expression levels of coactivators (peroxisome proliferator-activated receptor gamma coactivator 1-alpha (PGC1α)), transcription factors (peroxisome proliferator-activated receptor α (PPARα) and peroxisome proliferator-activated receptor γ (PPARγ)), and oxidative factors (carnitine palmitoyltransferase 1A (CPT1A) and HADHA). This phenomenon resulted in a significant increase in FaβO activity, ATP content, and JC-1 and a significant decrease in ROS level, TG content, and intracellular lipid droplets. With the addition of Dorsomorphin, all the effects of Lactucopicrin intervention were suppressed. In summary, Lactucopicrin promotes fatty acid β-oxidation by activating the AMPK pathway, thereby ameliorating FFA-induced intracellular lipid accumulation in HepG2 cells.

The role of HDAC3 in inflammation: mechanisms and therapeutic implications

Histone deacetylases (HDACs) are critical regulators of inflammatory gene expression, and the efficacy of pan-HDAC inhibitors has been implicated in various disease conditions. However, it remains largely unclear how HDACs precisely regulate inflammation. To this end, evaluating the isoform-specific function of HDACs is critical, and the isoform-specific targeting could also circumvent the off-target effects of pan-HDAC inhibitors. This review provides an overview of the roles of HDAC3, a class I HDAC isoform, in modulating inflammatory responses and discusses the molecular mechanisms by which HDAC3 regulates inflammation associated with brain pathology, arthritis, cardiovascular diseases, lung pathology, allergic conditions, and kidney disorders. The articles also identify knowledge gaps in the field for future studies. Despite some conflicting reports, the selective inhibition of HDAC3 has been demonstrated to play a beneficial role in various inflammatory pathologies. Exploring the potential of HDAC3 inhibition to improve disease prognosis is a promising avenue requiring further investigation.

Metabolism-inflammasome crosstalk shapes innate and adaptive immunity

Inflammasomes are a central component of innate immunity and play a vital role in regulating innate immune response. Activation of inflammasomes is also indispensable for adaptive immunity, modulating the development and response of adaptive immunity. Recently, increasing studies have shown that metabolic alterations and adaptations strongly influence and regulate the differentiation and function of the immune system. In this review, we will take a holistic view of how inflammasomes bridge innate and adaptive (especially T cell) immunity and how inflammasomes crosstalk with metabolic signals during the immune responses. And, special attention will be paid to the metabolic control of inflammasome-mediated interactions between innate and adaptive immunity in disease. Understanding the metabolic regulatory functions of inflammasomes would provide new insights into future research directions in this area and may help to identify potential targets for inflammasome-associated diseases and broaden therapeutic avenues.

Nanoceria-Mediated Cyclosporin A Delivery for Dry Eye Disease Management through Modulating Immune-Epithelial Crosstalk

Dry eye disease (DED) affects a substantial worldwide population with increasing frequency. Current single-targeting DED management is severely hindered by the existence of an oxidative stress-inflammation vicious cycle and complicated intercellular crosstalk within the ocular microenvironment. Here, a nanozyme-based eye drop, namely nanoceria loading cyclosporin A (Cs@P/CeO2), is developed, which possesses long-term antioxidative and anti-inflammatory capacities due to its regenerative antioxidative activity and sustained release of cyclosporin A (CsA). In vitro studies showed that the dual-functional Cs@P/CeO2 not only inhibits cellular reactive oxygen species production, sequentially maintaining mitochondrial integrity, but also downregulates inflammatory processes and repolarizes macrophages. Moreover, using flow cytometric and single-cell sequencing data, the in vivo therapeutic effect of Cs@P/CeO2 was systemically demonstrated, which rebalances the immune-epithelial communication in the corneal microenvironment with less inflammatory macrophage polarization, restrained oxidative stress, and enhanced epithelium regeneration. Collectively, our data proved that the antioxidative and anti-inflammatory Cs@P/CeO2 may provide therapeutic insights into DED management.

Targeting the lipid metabolic reprogramming of tumor-associated macrophages: A novel insight into cancer immunotherapy

BACKGROUND

Tumor-associated macrophages, as the major immunocytes in solid tumors, show divided loyalty and remarkable plasticity in tumorigenesis. Once the M2-to-M1 repolarization is achieved, they could be switched from the supporters for tumor development into the guardians for host immunity. Meanwhile, Lipid metabolic reprogramming is demonstrated to be one of the most important hallmarks of tumor-associated macrophages, which plays a decisive role in regulating their phenotypes and functions to promote tumorigenesis and immunotherapy resistance. Therefore, targeting the lipid metabolism of TAMs may provide a new direction for anti-tumor strategies.

CONCLUSION

In this review, we first summarized the origins, classifications and general lipid metabolic process of TAMs. Then we discussed the currently available drugs and interventions that target lipid metabolic disorders of TAMs, including those targeting lipid uptake, efflux, lipolysis, FAO and lipid peroxidation. Besides, based on the recent research status, we summarized the present challenges for this cancer immunotherapy, including the precise drug delivery system, the lipid metabolic heterogeneity, and the intricate lipid metabolic interactions in the TME, and we also proposed corresponding possible solutions. Collectively, we hope this review will give researchers a better understanding of the lipid metabolism of TAMs and lead to the development of corresponding anti-tumor therapies in the future.

Unraveling the complex roles of macrophages in obese adipose tissue: an overview

Macrophages, a heterogeneous population of innate immune cells, exhibit remarkable plasticity and play pivotal roles in coordinating immune responses and maintaining tissue homeostasis within the context of metabolic diseases. The activation of inflammatory macrophages in obese adipose tissue leads to detrimental effects, inducing insulin resistance through increased inflammation, impaired thermogenesis, and adipose tissue fibrosis. Meanwhile, adipose tissue macrophages also play a beneficial role in maintaining adipose tissue homeostasis by regulating angiogenesis, facilitating the clearance of dead adipocytes, and promoting mitochondrial transfer. Exploring the heterogeneity of macrophages in obese adipose tissue is crucial for unraveling the pathogenesis of obesity and holds significant potential for targeted therapeutic interventions. Recently, the dual effects and some potential regulatory mechanisms of macrophages in adipose tissue have been elucidated using single-cell technology. In this review, we present a comprehensive overview of the intricate activation mechanisms and diverse functions of macrophages in adipose tissue during obesity, as well as explore the potential of drug delivery systems targeting macrophages, aiming to enhance the understanding of current regulatory mechanisms that may be potentially targeted for treating obesity or metabolic diseases.

A proximity labeling-based orthogonal trap strategy identifies HDAC8 promotes cell motility by modulating cortactin acetylation

It is a challenge for the traditional affinity methods to capture transient interactions of enzyme-post-translational modification (PTM) substrates in vivo. Herein we presented a strategy termed proximity labeling-based orthogonal trap approach (ProLORT), relying upon APEX2-catalysed proximity labeling and an orthogonal trap pipeline as well as quantitative proteomics to directly investigate the transient interactome of enzyme-PTM substrates in living cells. As a proof of concept, ProLORT allows for robust evaluation of a known HDAC8 substrate, histone H3K9ac. By leveraging this approach, we identified numerous of putative acetylated proteins targeted by HDAC8, and further confirmed CTTN as a bona fide substrate in vivo. Next, we demonstrated that HDAC8 facilitates cell motility via deacetylation of CTTN at lysine 144 that attenuates its interaction with F-actin, expanding the underlying regulatory mechanisms of HDAC8. We developed a general strategy to profile the transient enzyme-substrate interactions mediated by PTMs, providing a powerful tool for identifying the spatiotemporal PTM-network regulated by enzymes in living cells.

Crosstalk of HDAC4, PP1, and GSDMD in controlling pyroptosis

Gasdermin D (GSDMD) functions as a pivotal executor of pyroptosis, eliciting cytokine secretion following cleavage by inflammatory caspases. However, the role of posttranslational modifications (PTMs) in GSDMD-mediated pyroptosis remains largely unexplored. In this study, we demonstrate that GSDMD can undergo acetylation at the Lysine 248 residue, and this acetylation enhances pyroptosis. We identify histone deacetylase 4 (HDAC4) as the specific deacetylase responsible for mediating GSDMD deacetylation, leading to the inhibition of pyroptosis both in vitro and in vivo. Deacetylation of GSDMD impairs its ubiquitination, resulting in the inhibition of pyroptosis. Intriguingly, phosphorylation of HDAC4 emerges as a critical regulatory mechanism promoting its ability to deacetylate GSDMD and suppress GSDMD-mediated pyroptosis. Additionally, we implicate Protein phosphatase 1 (PP1) catalytic subunits (PP1α and PP1γ) in the dephosphorylation of HDAC4, thereby nullifying its deacetylase activity on GSDMD. This study reveals a complex regulatory network involving HDAC4, PP1, and GSDMD. These findings provide valuable insights into the interplay among acetylation, ubiquitination, and phosphorylation in the regulation of pyroptosis, offering potential targets for further investigation in the field of inflammatory cell death.

Alisol A Exerts Neuroprotective Effects Against HFD-Induced Pathological Brain Aging via the SIRT3-NF-κB/MAPK Pathway

Chronic consumption of a high-fat diet (HFD) has profound effects on brain aging, which is mainly characterized by cognitive decline, inflammatory responses, and neurovascular damage. Alisol A (AA) is a triterpenoid with therapeutic potential for metabolic diseases, but whether it has a neuroprotective effect against brain aging caused by a HFD has not been investigated. Six-month-old male C57BL6/J mice were exposed to a HFD with or without AA treatment for 12 weeks. Behavioral tasks were used to assess the cognitive abilities of the mice. Neuroinflammation and changes in neurovascular structure in the brains were examined. We further assessed the mechanism by which AA exerts neuroprotective effects against HFD-induced pathological brain aging in vitro and in vivo. Behavioral tests showed that cognitive function was improved in AA-treated animals. AA treatment reduced microglia activation and inflammatory cytokine release induced by a HFD. Furthermore, AA treatment increased the number of hippocampal neurons, the density of dendritic spines, and the expression of tight junction proteins. We also demonstrated that AA attenuated microglial activation by targeting the SIRT3-NF-κB/MAPK pathway and ameliorated microglial activation-induced tight junction degeneration in endothelial cells and apoptosis in hippocampal neurons. The results of this study show that AA may be a promising agent for the treatment of HFD-induced brain aging.

Metabolic Flexibility of the Heart: The Role of Fatty Acid Metabolism in Health, Heart Failure, and Cardiometabolic Diseases

This comprehensive review explores the critical role of fatty acid (FA) metabolism in cardiac diseases, particularly heart failure (HF), and the implications for therapeutic strategies. The heart's reliance on ATP, primarily sourced from mitochondrial oxidative metabolism, underscores the significance of metabolic flexibility, with fatty acid oxidation (FAO) being a dominant source. In HF, metabolic shifts occur with an altered FA uptake and FAO, impacting mitochondrial function and contributing to disease progression. Conditions like obesity and diabetes also lead to metabolic disturbances, resulting in cardiomyopathy marked by an over-reliance on FAO, mitochondrial dysfunction, and lipotoxicity. Therapeutic approaches targeting FA metabolism in cardiac diseases have evolved, focusing on inhibiting or stimulating FAO to optimize cardiac energetics. Strategies include using CPT1A inhibitors, using PPARα agonists, and enhancing mitochondrial biogenesis and function. However, the effectiveness varies, reflecting the complexity of metabolic remodeling in HF. Hence, treatment strategies should be individualized, considering that cardiac energy metabolism is intricate and tightly regulated. The therapeutic aim is to optimize overall metabolic function, recognizing the pivotal role of FAs and the need for further research to develop effective therapies, with promising new approaches targeting mitochondrial oxidative metabolism and FAO that improve cardiac function.

The Role of Histone Deacetylases in NLRP3 Inflammasomesmediated Epilepsy

Epilepsy is one of the most common brain disorders that not only causes death worldwide, but also affects the daily lives of patients. Previous studies have revealed that inflammation plays an important role in the pathophysiology of epilepsy. Activation of inflammasomes can promote neuroinflammation by boosting the maturation of caspase-1 and the secretion of various inflammatory effectors, including chemokines, interleukins, and tumor necrosis factors. With the in-depth research on the mechanism of inflammasomes in the development of epilepsy, it has been discovered that NLRP3 inflammasomes may induce epilepsy by mediating neuronal inflammatory injury, neuronal loss and blood-brain barrier dysfunction. Therefore, blocking the activation of the NLRP3 inflammasomes may be a new epilepsy treatment strategy. However, the drugs that specifically block NLRP3 inflammasomes assembly has not been approved for clinical use. In this review, the mechanism of how HDACs, an inflammatory regulator, regulates the activation of NLRP3 inflammasome is summarized. It helps to explore the mechanism of the HDAC inhibitors inhibiting brain inflammatory damage so as to provide a potential therapeutic strategy for controlling the development of epilepsy.

Inflammaging and fatty acid oxidation in monocytes and macrophages

Fatty acid oxidation (FAO), primarily known as β-oxidation, plays a crucial role in breaking down fatty acids within mitochondria and peroxisomes to produce cellular energy and preventing metabolic dysfunction. Myeloid cells, including macrophages, microglia, and monocytes, rely on FAO to perform essential cellular functions and uphold tissue homeostasis. As individuals age, these cells show signs of inflammaging, a condition that includes a chronic onset of low-grade inflammation and a decline in metabolic function. These lead to changes in fatty acid metabolism and a decline in FAO pathways. Recent studies have shed light on metabolic shifts occurring in macrophages and monocytes during aging, correlating with an altered tissue environment and the onset of inflammaging. This review aims to provide insights into the connection of inflammatory pathways and altered FAO in macrophages and monocytes from older organisms. We describe a model in which there is an extended activation of receptor for advanced glycation end products, nuclear factor-κB (NF-κB) and the nod-like receptor family pyrin domain containing 3 inflammasome within macrophages and monocytes. This leads to an increased level of glycolysis, and also promotes pro-inflammatory cytokine production and signaling. As a result, FAO-related enzymes such as 5' AMP-activated protein kinase and peroxisome proliferator-activated receptor-α are reduced, adding to the escalation of inflammation, accumulation of lipids, and heightened cellular stress. We examine the existing body of literature focused on changes in FAO signaling within macrophages and monocytes and their contribution to the process of inflammaging.

Macrophage fatty acid oxidation in atherosclerosis

Atherosclerosis significantly contributes to the development of cardiovascular diseases (CVD) and is characterized by lipid retention and inflammation within the artery wall. Multiple immune cell types are implicated in the pathogenesis of atherosclerosis, macrophages play a central role as the primary source of inflammatory effectors in this pathogenic process. The metabolic influences of lipids on macrophage function and fatty acid β-oxidation (FAO) have similarly drawn attention due to its relevance as an immunometabolic hub. This review discusses recent findings regarding the impact of mitochondrial-dependent FAO in the phenotype and function of macrophages, as well as transcriptional regulation of FAO within macrophages. Finally, the therapeutic strategy of macrophage FAO in atherosclerosis is highlighted.

Gut microbiota-mediated IL-22 alleviates metabolic inflammation

Low-grade chronic inflammation, also known as metabolic inflammation, promotes the development of metabolic diseases. Increasing evidence suggests that changes in gut microbes and metabolites disrupt the integrity of the gut barrier and exert significant effects on the metabolism of various tissues, including the liver and adipose tissue, thereby contributing to metabolic inflammation. We observed that IL-22 is a key signaling molecule that serves as a bridge between intestinal microbes and the host, effectively alleviating metabolic inflammation by modulating the host immunomodulatory network. Here, we focused on elucidating the underlying mechanisms by which the gut microbiota and their metabolites reduce inflammation via IL-22, highlighting the favorable impact of IL-22 on metabolic inflammation. Furthermore, we discuss the potential of IL-22 as a therapeutic target for the management of metabolic inflammation and related diseases.

SEPTIN2 suppresses an IFN-γ-independent, proinflammatory macrophage activation pathway

Interferon-gamma (IFN-γ) signaling is necessary for the proinflammatory activation of macrophages but IFN-γ-independent pathways, for which the initiating stimuli and downstream mechanisms are lesser known, also contribute. Here we identify, by high-content screening, SEPTIN2 (SEPT2) as a negative regulation of IFN-γ-independent macrophage autoactivation. Mechanistically, endoplasmic reticulum (ER) stress induces the expression of SEPT2, which balances the competition between acetylation and ubiquitination of heat shock protein 5 at position Lysine 327, thereby alleviating ER stress and constraining M1-like polarization and proinflammatory cytokine release. Disruption of this negative feedback regulation leads to the accumulation of unfolded proteins, resulting in accelerated M1-like polarization, excessive inflammation and tissue damage. Our study thus uncovers an IFN-γ-independent macrophage proinflammatory autoactivation pathway and suggests that SEPT2 may play a role in the prevention or resolution of inflammation during infection.

COX17 acetylation via MOF-KANSL complex promotes mitochondrial integrity and function

Reversible acetylation of mitochondrial proteins is a regulatory mechanism central to adaptive metabolic responses. Yet, how such functionally relevant protein acetylation is achieved remains unexplored. Here we reveal an unprecedented role of the MYST family lysine acetyltransferase MOF in energy metabolism via mitochondrial protein acetylation. Loss of MOF-KANSL complex members leads to mitochondrial defects including fragmentation, reduced cristae density and impaired mitochondrial electron transport chain complex IV integrity in primary mouse embryonic fibroblasts. We demonstrate COX17, a complex IV assembly factor, as a bona fide acetylation target of MOF. Loss of COX17 or expression of its non-acetylatable mutant phenocopies the mitochondrial defects observed upon MOF depletion. The acetylation-mimetic COX17 rescues these defects and maintains complex IV activity even in the absence of MOF, suggesting an activatory role of mitochondrial electron transport chain protein acetylation. Fibroblasts from patients with MOF syndrome who have intellectual disability also revealed respiratory defects that could be restored by alternative oxidase, acetylation-mimetic COX17 or mitochondrially targeted MOF. Overall, our findings highlight the critical role of MOF-KANSL complex in mitochondrial physiology and provide new insights into MOF syndrome.

Transcription factors direct epigenetic reprogramming at specific loci in human cancers

The characterization of epigenetic changes during cancer development and progression led to notable insights regarding the roles of cancer-specific epigenetic reprogramming. Recent studies showed that transcription factors (TFs) are capable to regulate epigenetic reprogramming at specific loci in different cancer types through their DNA-binding activities. However, the causal association of dynamic histone modification change mediated by TFs is still not well elucidated. Here we evaluated the impacts of 636 transcription factor binding activities on histone modification in 24 cancer types. We performed Instrumental Variables analysis by using genetic lesions of TFs as our instrumental proxies, which previously discovered to be associated with histone mark activities. As a result, we showed a total of 6 EpiTFs as strong directors of epigenetic reprogramming of histone modification in cancers, which alters the molecular and clinical phenotypes of cancer. Together our findings highlight a causal mechanism driven by the TFs and genome-wide histone modification, which is relevant to multiple status of oncogenesis.

Mitochondrial metabolism-related signature depicts immunophenotype and predicts therapeutic response in testicular germ cell tumors

In recent years, there has been growing evidence linking mitochondrial dysfunction to the development and progression of cancer. However, the role of mitochondrial metabolism-related genes (MMRGs) in testicular germ cell tumor (TGCT) remains unclear. We downloaded clinical pathology, transcriptome, and somatic mutation data for TGCT from public databases and conducted univariate Cox regression analysis to investigate prognostic correlations. We also used consensus clustering to identify molecular subtypes, comparing differential expression genes, biological processes, Kyoto Encyclopedia of Genes and Genomes pathways, mutations, prognosis, immune infiltration, drug sensitivity, and immune therapeutic response between these subtypes. We constructed multi-gene risk features and nomograms for TGCT prognosis. Fifteen MMRGs were significantly correlated with progression-free survival in TGCT patients. Based on these genes, we identified 2 molecular subtypes which showed significant differences in somatic mutations, prognosis, and immune cell infiltration. These subtypes could also indicate drug sensitivity and immune therapeutic response; the subtype with poor prognosis showed a higher potential benefit from some drugs and immunotherapy. Abnormalities in immune-related biological processes and extracellular matrix as well as Kyoto Encyclopedia of Genes and Genomes pathways such as PI3K-AKT signaling pathway, pat5hways in cancer, primary immunodeficiency, and neutrophil extracellular trap formation were associated with significant differences in phenotypes among subtypes. Finally, we constructed an 8-gene TGCT risk feature based on differential expression genes between subtypes which performed well in TGCT patient prognostic evaluation. Our study elucidated the prognostic correlation between MMRGs and TGCT and established MMRG-derived molecular subtypes and risk features for personalized treatment of TGCT which have potential clinical application value.