Polycomb-repressed genes have permissive enhancers that initiate reprogramming.

Key regulatory genes, suppressed by Polycomb and H3K27me3, become active during normal differentiation and induced reprogramming. Using the well-characterized enhancer/promoter pair of MYOD1 as a model, we have identified a critical role for enhancers in reprogramming. We observed an unexpected nucleosome-depleted region (NDR) at the H3K4me1-enriched enhancer at which transcriptional regulators initially bind, leading to subsequent changes in the chromatin at the cognate promoter. Exogenous Myod1 activates its own transcription by binding first at the enhancer, leading to an NDR and transcription-permissive chromatin at the associated MYOD1 promoter. Exogenous OCT4 also binds first to the permissive MYOD1 enhancer but has a different effect on the cognate promoter, where the monovalent H3K27me3 marks are converted to the bivalent state characteristic of stem cells. Genome-wide, a high percentage of Polycomb targets are associated with putative enhancers in permissive states, suggesting that they may provide a widespread avenue for the initiation of cell-fate reprogramming.

Mdivi-1: Effective but complex mitochondrial fission inhibitor.

Mdivi-1, Mitochondrial DIVIsion inhibitor 1, has been widely employed in research under the assumption that it exclusively influences mitochondrial fusion, but effects other than mitochondrial dynamics have been underinvestigated. This paper provides transcriptome and DNA methylome-wide analysis for Mdivi-1 treated SH-SY5Y human neuroblastoma cells using RNA sequencing (RNA-seq) and methyl capture sequencing (MC-seq) methods. Gene ontology analysis of RNA sequences revealed that p53 transcriptional gene network and DNA replication initiation-related genes were significantly up and down-regulated, respectively, showing the correlation with the arrest cell cycle in the G1 phase. MC-seq, a powerful sequencing method for capturing DNA methylation status in CpG sites, revealed that although Mdivi-1 does not induce dramatic DNA methylation change, the subtle alterations were concentrated within the CpG island. Integrative analysis of both sequencing data disclosed that the p53 transcriptional network was activated while the Parkinson's disease pathway was halted. Next, we investigated several changes in mitochondria in response to Mdivi-1. Copy number and transcription of mitochondrial DNA were suppressed. ROS levels increased, and elevated ROS triggered mitochondrial retrograde signaling rather than inducing direct DNA damage. In this study, we could better understand the molecular network of Mdivi-1 by analyzing DNA methylation and mRNA transcription in the nucleus and further investigating various changes in mitochondria, providing inspiration for studying nuclear-mitochondrial communications.

S6K1 Phosphorylation of H2B Mediates EZH2 Trimethylation of H3: A Determinant of Early Adipogenesis.

S6K1 has been implicated in a number of key metabolic responses, which contribute to obesity. Critical among these is the control of a transcriptional program required for the commitment of mesenchymal stem cells to the adipocytic lineage. However, in contrast to its role in the cytosol, the functions and targets of nuclear S6K1 are unknown. Here, we show that adipogenic stimuli trigger nuclear translocation of S6K1, leading to H2BS36 phosphorylation and recruitment of EZH2 to H3, which mediates H3K27 trimethylation. This blocks Wnt gene expression, inducing the upregulation of PPARγ and Cebpa and driving increased adipogenesis. Consistent with this finding, white adipose tissue from S6K1-deficient mice exhibits no detectable H2BS36 phosphorylation or H3K27 trimethylation, whereas both responses are highly elevated in obese humans or in mice fed a high-fat diet. These findings define an S6K1-dependent mechanism in early adipogenesis, contributing to the promotion of obesity.

Nuclear S6K1 Enhances Oncogenic Wnt Signaling by Inducing Wnt/ß-Catenin Transcriptional Complex Formation.

Ribosomal protein S6 kinase 1 (S6K1), a key downstream effector of the mammalian target of rapamycin (mTOR), regulates diverse functions, such as cell proliferation, cell growth, and protein synthesis. Because S6K1 was previously known to be localized in the cytoplasm, its function has been mainly studied in the cytoplasm. However, the nuclear localization and function of S6K1 have recently been elucidated and other nuclear functions are expected to exist but remain elusive. Here, we show a novel nuclear role of S6K1 in regulating the expression of the Wnt target genes. Upon activation of the Wnt signaling, S6K1 translocated from the cytosol into the nucleus and subsequently bound to ß-catenin and the cofactors of the Wnt/ß-catenin transcriptional complex, leading to the upregulation of the Wnt target genes. The depletion or repression of S6K1 downregulated the Wnt target gene expression by inhibiting the formation of the Wnt/ß-catenin transcriptional complex. The S6K1-depleted colon cancer cell lines showed lower transcription levels of the Wnt/ß-catenin target genes and a decrease in the cell proliferation and invasion compared to the control cell lines. Taken together, these results indicate that nuclear S6K1 positively regulates the expression of the Wnt target genes by inducing the reciprocal interaction of the subunits of the transcriptional complex.

Hexosamine Biosynthetic Pathway-Derived O-GlcNAcylation Is Critical for RANKL-Mediated Osteoclast Differentiation.

O-linked-N-acetylglucosaminylation (O-GlcNAcylation) performed by O-GlcNAc transferase (OGT) is a nutrient-responsive post-translational modification (PTM) via the hexosamine biosynthetic pathway (HBP). Various transcription factors (TFs) are O-GlcNAcylated, affecting their activities and significantly contributing to cellular processes ranging from survival to cellular differentiation. Given the pleiotropic functions of O-GlcNAc modification, it has been studied in various fields; however, the role of O-GlcNAcylation during osteoclast differentiation remains to be explored. Kinetic transcriptome analysis during receptor activator of nuclear factor-kappaB (NF-κB) ligand (RANKL)-mediated osteoclast differentiation revealed that the nexus of major nutrient metabolism, HBP was critical for this process. We observed that the critical genes related to HBP activation, including Nagk, Gfpt1, and Ogt, were upregulated, while the global O-GlcNAcylation was increased concomitantly during osteoclast differentiation. The O-GlcNAcylation inhibition by the small-molecule inhibitor OSMI-1 reduced osteoclast differentiation in vitro and in vivo by disrupting the translocation of NF-κB p65 and nuclear factor of activated T cells c1 (NFATc1) into the nucleus by controlling their PTM O-GlcNAcylation. Furthermore, OSMI-1 had a synergistic effect with bone target therapy on osteoclastogenesis. Lastly, knocking down Ogt with shRNA (shOgt) mimicked OSMI-1's effect on osteoclastogenesis. Targeting O-GlcNAcylation during osteoclast differentiation may be a valuable therapeutic approach for osteoclast-activated bone diseases.

SMARCB1 Acts as a Quiescent Gatekeeper for Cell Cycle and Immune Response in Human Cells.

Switch/sucrose non-fermentable (SWI/SNF)-related matrix-associated actin-dependent regulator of chromatin (SMARC) subfamily B member 1 (SMARCB1) is a core subunit of the switch/sucrose non-fermentable (SWI/SNF) complex, one of the adenosine triphosphate (ATP)-dependent chromatin remodeler complexes. The unique role of SMARCB1 has been reported in various cellular contexts. Here, we focused on the general role of the ubiquitous expression of SMARCB1 in a normal cell state. We selected ARPE19 (human primary retinal pigment epithelium) and IMR90 (from human fetal lung fibroblasts) cell lines as they have completely different contexts. Furthermore, although these cell lines have been immortalized, they are relatively close to normal human cells. The loss of SMARCB1 in ARPE19 and IMR90 cells reduced cell cycle progression via the upregulation of P21. Transcriptome analysis followed by SMARCB1 knockdown in both cell lines revealed that SMARCB1 was not only involved in cell maintenance but also conferred immunomodulation. Of note, SMARCB1 bound to interleukin (IL) 6 promoter in a steady state and dissociated in an active immune response state, suggesting that SMARCB1 was a direct repressor of IL6, which was further confirmed via loss- and gain-of-function studies. Taken together, we demonstrated that SMARCB1 is a critical gatekeeper molecule of the cell cycle and immune response.

Alcohol dysregulates miR-148a in hepatocytes through FoxO1, facilitating pyroptosis via TXNIP overexpression.

OBJECTIVE: Alcoholic liver disease (ALD) is a leading cause of death among chronic liver diseases. However, its pathogenesis has not been completely established. MicroRNAs (miRNAs) are key contributors to liver diseases progression. This study investigated hepatocyte-abundant miRNAs dysregulated by ALD, its impact on hepatocyte injury and the underlying basis. DESIGN: Alcoholic hepatitis (AH) human and animal liver samples and hepatocytes were used to assess miR-148a levels. Pre-miR-148a was delivered specifically to hepatocytes in vivo using lentivirus. Immunoblottings, luciferase reporter assays, chromatin immunoprecipitation and immunofluorescence assays were carried out in cell models. RESULTS: The miRNA profile and PCR analyses enabled us to find substantial decrease of miR-148a in the liver of patients with AH. In mice subjected to Lieber-DeCarli alcohol diet or binge alcohol drinking, miR-148a levels were also markedly reduced. In cultured hepatocytes and mouse livers, alcohol exposure inhibited forkhead box protein O1 (FoxO1) expression, which correlated with miR-148a levels and significantly decreased in human AH specimens. FoxO1 was identified as a transcription factor for MIR148A transactivation. MiR-148a directly inhibited thioredoxin-interacting protein (TXNIP) expression. Consequently, treatment of hepatocytes with ethanol resulted in TXNIP overexpression, activating NLRP3 inflammasome and caspase-1-mediated pyroptosis. These events were reversed by miR-148a mimic or TXNIP small-interfering RNA transfection. Hepatocyte-specific delivery of miR-148a to mice abrogated alcohol-induced TXNIP overexpression and inflammasome activation, attenuating liver injury. CONCLUSION: Alcohol decreases miR-148a expression in hepatocytes through FoxO1, facilitating TXNIP overexpression and NLRP3 inflammasome activation, which induces hepatocyte pyroptosis. Our findings provide information on novel targets for reducing incidence and progression of ALD.

SOX9 is controlled by the BRD4 inhibitor JQ1 via multiple regulation mechanisms.

SOX9 is a key transcription factor during cell differentiation, sex determination, and tumorigenesis. However, the detailed mechanisms of its targeting strategy remain elusive. To investigate possibilities of targeting SOX9 with epigenetic drugs and the precise underlying mechanisms, two human cancer cell lines were chosen as model systems, which showed high SOX9 expression and anti-tumorigenic effects upon loss of SOX9. Histone acetylation-related screening of a small panel of epigenetic drugs revealed that the bromodomain reader inhibitor JQ1 dramatically downregulated SOX9 through multiple regulation steps, namely, transcription, BRD4-SOX9 protein-protein interaction, and further protein stability. These findings suggest that BRD4 inhibition is a novel therapeutic strategy for diseases characterized by SOX9 overexpression.

Suppression of interferon-mediated anti-HBV response by single CpG methylation in the 5'-UTR of TRIM22.

OBJECTIVE: Interferons (IFNs) mediate direct antiviral activity. They play a crucial role in the early host immune response against viral infections. However, IFN therapy for HBV infection is less effective than for other viral infections. DESIGN: We explored the cellular targets of HBV in response to IFNs using proteome-wide screening. RESULTS: Using LC-MS/MS, we identified proteins downregulated and upregulated by IFN treatment in HBV X protein (HBx)-stable and control cells. We found several IFN-stimulated genes downregulated by HBx, including TRIM22, which is known as an antiretroviral protein. We demonstrated that HBx suppresses the transcription of TRIM22 through a single CpG methylation in its 5'-UTR, which further reduces the IFN regulatory factor-1 binding affinity, thereby suppressing the IFN-stimulated induction of TRIM22. CONCLUSIONS: We verified our findings using a mouse model, primary human hepatocytes and human liver tissues. Our data elucidate a mechanism by which HBV evades the host innate immune system.

Establishment of active chromatin structure at enhancer elements by mixed-lineage leukemia 1 to initiate estrogen-dependent gene expression.

A number of genome-wide analyses have revealed that estrogen receptor α binding to and regulation of its target genes correlate with binding of FOXA1, a pioneer factor, to nearby DNA sites in MCF-7 breast cancer cells. The enhancer element-specific histone H3K4me1/2 mark is enriched at the specific FOXA1/ERα recruitment sites in chromatin, but the mechanism by which these enhancer marks are established in chromatin before hormone treatment is unclear. Here, we show that mixed-lineage leukemia 1 (MLL1) protein is a key determinant that maintains permissive chromatin structure of the TFF1 enhancer region. MLL1 occupies the TFF1 enhancer region and methylates H3K4 before hormone stimulation. In vitro, MLL1 binds directly to the CpG-rich region of the TFF1 enhancer, and its binding is dependent on hypomethylation of DNA. Furthermore, the depletion of MLL1 in MCF-7 cells results in a dramatic decrease of chromatin accessibility and recruitment of FOXA1 and ERα to the enhancer element. Our study defines the mechanism by which MLL1 nucleates histone H3K4 methylation marks in CpG-enriched regions to maintain permissive chromatin architecture and allow FOXA1 and estrogen receptor α binding to transcriptional regulatory sites in breast cancer cells.

SNF5 is an essential executor of epigenetic regulation during differentiation.

Nucleosome occupancy controls the accessibility of the transcription machinery to DNA regulatory regions and serves an instructive role for gene expression. Chromatin remodelers, such as the BAF complexes, are responsible for establishing nucleosome occupancy patterns, which are key to epigenetic regulation along with DNA methylation and histone modifications. Some reports have assessed the roles of the BAF complex subunits and stemness in murine embryonic stem cells. However, the details of the relationships between remodelers and transcription factors in altering chromatin configuration, which ultimately affects gene expression during cell differentiation, remain unclear. Here for the first time we demonstrate that SNF5, a core subunit of the BAF complex, negatively regulates OCT4 levels in pluripotent cells and is essential for cell survival during differentiation. SNF5 is responsible for generating nucleosome-depleted regions (NDRs) at the regulatory sites of OCT4 repressed target genes such as PAX6 and NEUROG1, which are crucial for cell fate determination. Concurrently, SNF5 closes the NDRs at the regulatory regions of OCT4-activated target genes such as OCT4 itself and NANOG. Furthermore, using loss- and gain-of-function experiments followed by extensive genome-wide analyses including gene expression microarrays and ChIP-sequencing, we highlight that SNF5 plays dual roles during differentiation by antagonizing the expression of genes that were either activated or repressed by OCT4, respectively. Together, we demonstrate that SNF5 executes the switch between pluripotency and differentiation.

The Epigenetic Reader BRD2 as a Specific Modulator of PAI-1 Expression in Lipopolysaccharide-Stimulated Mouse Primary Astrocytes.

The post translational modification of lysine acetylation is a key mechanism that regulates chromatin structure. Epigenetic readers, such as the BET domains, are responsible for reading histone lysine acetylation which is a hallmark of open chromatin structure, further providing a scaffold that can be accessed by RNA polymerases as well as transcription factors. Recently, several reports have assessed and highlighted the roles of epigenetic readers in various cellular contexts. However, little is known about their role in the regulation of inflammatory genes, which is critical in exquisitely tuning inflammatory responses to a variety of immune stimuli. In this study, we investigated the role of epigenetic readers BRD2 and BRD4 in the lipopolysaccharide (LPS)-induced immune responses in mouse primary astrocytes. Inflammatory stimulation by LPS showed that the levels of Brd2 mRNA and protein were increased, while Brd4 mRNA levels did not change. Knocking down of Brd2 mRNA using specific small interfering RNA (siRNA) in cultured mouse primary astrocytes inhibited LPS-induced mRNA expression and secretion of plasminogen activator inhibitor-1 (PAI-1). However, no other pro-inflammatory cytokines, such as Il-6, Il-1ß and Tnf-α, were affected. Indeed, treatment with bromodomain-containing protein inhibitor, JQ1, blocked Pai-1 mRNA expression through the inhibition of direct BRD2 protein-binding and active histone modification on Pai-1 promoter. Taken together, our data suggest that BRD2 is involved in the modulation of neuroinflammatory responses through PAI-1 and via the regulation of epigenetic reader BET protein, further providing a potential novel therapeutic strategy in neuroinflammatory diseases.

Functional DNA demethylation is accompanied by chromatin accessibility.

DNA methylation inhibitors such as 5-aza-2'-deoxycytidine (5-Aza-CdR) are currently used for the treatment of myelodysplastic syndrome. Although global DNA demethylation has been observed after treatment, it is unclear to what extent demethylation induces changes in nucleosome occupancy, a key determinant of gene expression. We use the colorectal cancer cell line HCT116 as a model to address this question and determine that <2% of regions demethylated by 5-Aza-CdR treatment assume an open configuration. Consolidating our findings, we detect nucleosome retention at sites of global DNA methylation loss in DKO1, an HCT116-derived non-tumorigenic cell-line engineered for DNA methyltransferase disruption. Notably, regions that are open in both HCT116 cells after treatment and in DKO1 cells include promoters belonging to tumor suppressors and genes under-expressed in colorectal cancers. Our results indicate that only a minority of demethylated promoters are associated with nucleosome remodeling, and these could potentially be the epigenetic drivers causing the loss of tumorigenicity. Furthermore, we show that the chromatin opening induced by the histone deacetylase inhibitor suberoylanilide hydroxamic acid has strikingly distinct targets compared with those of 5-Aza-CdR, providing a mechanistic explanation for the importance of combinatorial therapy in eliciting maximal de-repression of the cancer epigenome.

Characteristic molecular and proteomic signatures of drug-induced liver injury in a rat model.

Drug-induced liver injury (DILI) is a major safety concern during drug development and remains one of the main reasons for withdrawal of drugs from the market. Although it is crucial to develop methods that will detect potential hepatotoxicity of drug candidates as early and as quickly as possible, there is still a lack of sensitive and specific biomarkers for DILI that consequently leads to a scarcity of reliable hepatotoxic data. Hence, in this study, we assessed characteristic molecular signatures in rat liver treated with drugs (pyrazinamide, ranitidine, enalapril, carbamazepine and chlorpromazine) that are known to cause DILI in humans. Unsupervised hierarchical clustering analysis of transcriptome changes induced by DILI-causing drugs resulted in three different subclusters on dendrogram, i.e., hepatocellular, cholestatic and mixed type of DILI at early time points (2 days), and multiclassification analysis suggested 31 genes as discernible markers for each DILI pattern. Further analysis for characteristic molecular signature of each DILI pattern provided a molecular basis for different modes of DILI action. A proteomics study of the same rat livers was used to confirm the results, and the two sets of data showed 60 matching classifiers. In conclusion, the data of different DILI-causing drug treatments from genomic analysis in a rat model suggest that DILI-specific molecular signatures can discriminate different patterns of DILI at an early exposure time point, and that they provide useful information for mechanistic studies that may lead to a better understanding of the molecular basis of DILI.

Rhamnus davurica leaf extract inhibits Fyn activation by antigen in mast cells for anti-allergic activity.

BACKGROUND: Complementary and alternative herbal medicines are recently considered as a promising approach for treating various diseases. We screened approximately 100 plant extracts for anti-allergic activity. Rhamnus davurica leaf extract showed the most potent inhibitory effect on the activation of RBL-2H3 mast cells. Although Rhamnus davurica extract has been used to treat pruritus, dysuresia, and constipation as a traditional herbal medicine in some Asian countries, an anti-allergic effect of Rhamnus davurica has not yet been demonstrated. We aimed to investigate the effect and mechanism of the leaf extract of Rhamnus davurica (LERD) on mast cells in vitro and allergic responses in vivo. METHODS: The effects of LERD on the activation of mast cells and mast cell-mediated passive cutaneous anaphylaxis (PCA) were measured in mice and two types of mast cells, mouse bone marrow-derived mast cells (BMMCs) and RBL-2H3 cells in vitro. A mechanistic study of its inhibitory effect was performed by using degranulation assay, reverse transcriptase-polymerase chain reaction, enzyme-linked immunosorbent assay, and western blotting analysis. RESULTS: LERD reversibly suppressed antigen-stimulated degranulation in BMMCs and RBL-2H3 cells, and also inhibited mRNA expression and secretion of TNF-α and IL-4 in a dose-dependent manner. In a PCA animal model, LERD significantly inhibited antigen-induced allergic response and degranulation of ear tissue mast cells. As for the mechanism of action, LERD inhibited the activation of Syk, which is the pivotal signaling protein for mast cell activation by antigen. Furthermore, LERD also impeded the activations of well-known downstream proteins such as LAT, Akt and three MAP kinases (Erk, p38 and JNK). In an in vitro kinase assay, LERD suppressed the activation of Fyn in antigen-stimulated mast cells. CONCLUSION: This study demonstrated for the first time that LERD has anti-allergic effects through inhibiting the Fyn/Syk pathway in mast cells. Therefore, this study provides scientific evidence for LERD to be used as an herbal medicine or health food for patients with allergic diseases.

OCT4 establishes and maintains nucleosome-depleted regions that provide additional layers of epigenetic regulation of its target genes.

Recent epigenome-wide mapping studies describe nucleosome-depleted regions (NDRs) at transcription start sites and enhancers. However, these static maps do not address causality or the roles of NDRs in gene control, and their relationship to transcription factors and DNA methylation is not well understood. Using a high-resolution single-molecule mapping approach to simultaneously investigate endogenous DNA methylation and nucleosome occupancies on individual DNA molecules, we show that the unmethylated OCT4 distal enhancer has an NDR, whereas NANOG has a clear NDR at its proximal promoter. These NDRs are maintained by binding of OCT4 and are required for OCT4 and NANOG expression. Differentiation causes a rapid loss of both NDRs accompanied by nucleosome occupancy, which precedes de novo DNA methylation. NDRs can be restored by forced expression of OCT4 in somatic cells but only when there is no cytosine methylation. These data show the central role of the NDRs, established by OCT4, in ensuring the autoregulatory loop of pluripotency and, furthermore, that de novo methylation follows the loss of NDRs and stabilizes the suppressed state.

Epigenetic landscape analysis reveals the significance of early reduced chromatin accessibility in osteoclastogenesis.

Recently improved techniques could provide snapshots of chromatin structure generated based on chromatin accessibility. Since chromatin accessibility determines transcriptional potential, it has been attempted in a variety of cell systems. However, there has been no genome-wide analysis of chromatin accessibility for the entire murine osteoclast (OC) differentiation process. We performed an Assay for Transposase-Accessible Chromatin (ATAC)-sequencing (seq) during RANKL-induced OC differentiation and found that global chromatin accessibility decreased, especially early in OC differentiation. The global histone H3K27Ac level, an active histone modification mark, was diminished during OC differentiation by western blot and histone extract experiments. Its genomic enrichment was also reduced based on publicly available H3K27Ac chromatin immunoprecipitation (ChIP)-seq data. ATAC-seq and H3K27Ac ChIP-seq data demonstrated that RANKL induced a less accessible chromatin state during OC differentiation. Restoration of reduced H3K27Ac, presumably representing accessible states upon acetate treatment, suppresses OC differentiation by provoking immune-related gene expression. Subsequential integrative analysis of ATAC-seq, RNA-seq after acetate treatment, and H3K27Ac ChIP-seq reveals that Irf8 and its downstream targets are the most vulnerable to chromatin accessibility changes and acetate supplementation. Taken together, our study generated chromatin accessibility maps during the whole OC differentiation and suggested perturbation of chromatin accessibility might be a potential therapeutic strategy for excessive OC diseases.

Senescence and impaired DNA damage responses in alpha-synucleinopathy models.

α-Synuclein is a crucial element in the pathogenesis of Parkinson's disease (PD) and related neurological diseases. Although numerous studies have presented potential mechanisms underlying its pathogenesis, the understanding of α-synuclein-mediated neurodegeneration remains far from complete. Here, we show that overexpression of α-synuclein leads to impaired DNA repair and cellular senescence. Transcriptome analysis showed that α-synuclein overexpression led to cellular senescence with activation of the p53 pathway and DNA damage responses (DDRs). Chromatin immunoprecipitation analyses using p53 and γH2AX, chromosomal markers of DNA damage, revealed that these proteins bind to promoters and regulate the expression of DDR and cellular senescence genes. Cellular marker analyses confirmed cellular senescence and the accumulation of DNA double-strand breaks. The non-homologous end joining (NHEJ) DNA repair pathway was activated in α-synuclein-overexpressing cells. However, the expression of MRE11, a key component of the DSB repair system, was reduced, suggesting that the repair pathway induction was incomplete. Neuropathological examination of α-synuclein transgenic mice showed increased levels of phospho-α-synuclein and DNA double-strand breaks, as well as markers of cellular senescence, at an early, presymptomatic stage. These results suggest that the accumulation of DNA double-strand breaks (DSBs) and cellular senescence are intermediaries of α-synuclein-induced pathogenesis in PD.

Glutamine metabolite α-ketoglutarate acts as an epigenetic co-factor to interfere with osteoclast differentiation.

Osteoclasts (OCs) have been well-known involved in the exacerbation of bone-related diseases. However, the role of metabolites on osteoclastogenesis has not been well characterized. Herein, we found osteoclastogenesis was negatively regulated by α-ketoglutarate (αKG) in vitro and in vivo (C57BL/6 mouse). Kinetic transcriptome analysis revealed the upregulation of solute carrier family 7 member 11 (Slc7a11), a subunit of the cysteine/glutamate antiporter, as well as the downregulation of typical OC maker genes through αKG treatment. Given that Slc7a11 could control ROS level through glutathione import, we measured intracellular ROS, then RANKL-induced ROS production was inhibited by αKG. Notably, we highlight that αKG plays an epigenetic co-factor at the Slc7a11 promoter by demethylating repressive histone H3K9 methylation and simultaneously increasing the nuclear factor erythroid 2-related factor (Nrf2) binding, a critical transcription factor through chromatin immunoprecipitation (ChIP) analysis. Together, we suggested that αKG could be a therapeutic strategy for OC activated diseases.

IOX1 activity as sepsis therapy and an antibiotic against multidrug-resistant bacteria.

Sepsis is caused by organ dysfunction initiated by an unrestrained host immune response to infection. The emergence of antibiotic-resistant bacteria has rapidly increased in the last decades and has stimulated a firm research platform to combat infections caused by antibiotic-resistant bacteria that cannot be eradicated with conventional antibiotics. Strategies like epigenetic regulators such as lysine demethylase (Kdm) has received attention as a new target. Thus, we sought to investigate the epigenetic mechanisms in sepsis pathophysiology with the aim of discovering new concepts for treatment. A transcriptome analysis of dendritic cells during their inflammatory state identified Kdm as a critical molecule in sepsis regulation. Next, 8-hydroxyquinoline-5-carboxylic acid (IOX1) ability to control endotoxemia induced by Lipopolysaccharide and bacterial sepsis was demonstrated. IOX1 has been shown to regulate endotoxemia and sepsis caused by Escherichia coli and carbapenem-resistant Acinetobacter baumannii and has also contributed to the suppression of multidrug-resistant bacterial growth through the inhibition of DNA Gyrase. These findings show that IOX1 could be a component agent against bacterial sepsis by functioning as a broad-spectrum antibiotic with dual effects.