Lysine-specific Demethylase 6B Research Articles

Epigenetic mechanism of RBM15 in affecting cisplatin resistance in laryngeal carcinoma cells by regulating ferroptosis

Laryngeal carcinoma (LC) is a common cancer of the respiratory tract. This study aims to investigate the role of RNA-binding motif protein 15 (RBM15) in the cisplatin (DDP) resistance of LC cells. LC-DDP-resistant cells were constructed. RBM15, lysine-specific demethylase 5B (KDM5B), lncRNA Fer-1 like family member 4 (FER1L4), lncRNA KCNQ1 overlapping transcript 1 (KCNQ1OT1), glutathione peroxidase 4 (GPX4), and Acyl-CoA synthetase long-chain family (ACSL4) was examined. Cell viability, IC50, and proliferation were assessed after RBM15 downregulation. The enrichment of insulin-like growth factor 2 mRNA-binding protein 3 (IGF2BP3) and N6-methyladenosine (m6A) on KDM5B was analyzed. KDM5B mRNA stability was measured after actinomycin D treatment. A tumor xenograft assay was conducted to verify the role of RBM15 in LC. Results showed that RBM15 was upregulated in LC and its knockdown decreased IC50, cell viability, proliferation, glutathione, and upregulated iron ion content, ROS, malondialdehyde, ACSL4, and ferroptosis. Mechanistically, RBM15 improved KDM5B stability in an IGF2BP3-dependent manner, resulting in FER1L4 downregulation and GPX4 upregulation. KDM5B increased KCNQ1OT1 and inhibited ACSL4. KDM5B/KCNQ1OT1 overexpression or FER1L4 knockdown promoted DDP resistance in LC by inhibiting ferroptosis. In conclusion, RBM15 promoted KDM5B expression, and KDM5B upregulation inhibited ferroptosis and promoted DDP resistance in LC by downregulating FER1L4 and upregulating GPX4, as well as by upregulating KCNQ1OT1 and inhibiting ACSL4. Silencing RBM15 inhibited tumor growth in vivo.

ETS homologous factor, controlled by lysine-specific demethylase 5B, suppresses clear cell renal cell carcinoma by inducing Filamin-B

BackgroundClear cell renal cell carcinoma (ccRCC) remains a deadly disease with a poor prognosis. Here, we identified the ETS homologous factor (EHF) and its target Filamin-B (FLNB) as molecules related to immune evasion in ccRCC. We also explored the upstream modifier that manipulates EHF in ccRCC. DesignCell proliferation and apoptosis assay, wound healing assay, and Transwell assay were designed to analyze the effects of EHF or FLNB knockdown on the biological activity of ccRCC cells. The growth of differently treated ccRCC cells was assessed by orthotopic tumors. ccRCC cells with different treatments were co-cultured with macrophages, and the role of the lysine-specific demethylase 5B (KDM5B)/EHF/FLNB axis on macrophage polarization or ccRCC progression was characterized by detecting the expression of M2 macrophage markers in the co-culture system or tumor tissues of tumor-bearing mice. ResultsThe expression of EHF and FLNB was higher, while KDM5B was lower in HK2 cells than in ccRCC cells. EHF overexpression inhibited the biological behavior of ccRCC cells and tumor growth in mice. EHF activated FLNB transcription. Knockdown of FLNB supported the biological activity of ccRCC cells and tumor growth and reversed M2 macrophage polarization in tumor tissues of mice in the presence of EHF. KDM5B inhibited EHF expression by H3K4me3 demethylation, and EHF knockdown potentiated M2 macrophage polarization and tumor growth in vivo repressed by KDM5B knockdown. ConclusionsKDM5B inhibited the expression of EHF by repressing H3K4me3 modification and the transcription of FLNB by EHF to promote immune evasion and progression of ccRCC.

KDM5B promotes SMAD4 loss-driven drug resistance through activating DLG1/YAP to induce lipid accumulation in pancreatic ductal adenocarcinoma

Inactivated suppressor of mothers against decapentaplegic homolog (SMAD) 4 significantly affects cancer development in pancreatic ductal adenocarcinoma (PDAC). However, the contribution of smad4 loss to drug resistance in PDAC is largely undetermined. In the present study, we reported that the loss of SMAD4 endows PDAC cells the ability to drug resistance through upregulating histone lysine demethylase, Lysine-Specific Demethylase 5B (KDM5B, also known as JARID1B or PLU1). Upregulated KDM5B was found in PDAC, associated with poor prognosis and recurrence of PDAC patients. Upregulated KDM5B promotes PDAC tumor malignancy, i.e. cancer cells stemness and drug resistance in vitro and in vivo, while KDM5B knockout exerts opposite effects. Mechanistically, loss of Smad4-mediated upregulation of KDM5B promotes drug resistance through inhibiting the discs-large homolog 1 (DLG1), thereby facilitating nuclear translocation of YAP to induce de novo lipogenesis. Moreover, m6A demethylase FTO is involved in the upregulation of KDM5B by maintaining KDM5B mRNA stability. Collectively, the present study suggested FTO-mediated KDM5B stabilization in the context of loss of Smad4 activate DLG1/YAP1 pathway to promote tumorigenesis by reprogramming lipid accumulation in PDAC. Our study confirmed that the KDM5B-DLG1-YAP1 pathway axis plays a crucial role in the genesis and progression of PDAC, and KDM5B was expected to become a target for the treatment of PDAC.The schematic diagram of KDM5B-DLG1-YAP pathway axis in regulating drug resistance of PDAC to gemcitabine (GEM). In the context of SMAD4 loss PDAC cells, FTO-mediated stabilization and upregulation of KDM5B promotes drug resistance through directly targeting DLG1 to promote YAP1 translocation to nucleus to induce de novo lipogenesis (DNL).

Discovery of an efficacious KDM5B PROTAC degrader GT-653 up-regulating IFN response genes in prostate cancer

Epigenetic alterations promote cancer development by regulating the expression of various oncogenes and anti-oncogenes. Histone methylation modification represents a pivotal area in epigenetic research and numerous publications have demonstrated that aberrant histone methylation is highly correlated with tumorigenesis and development. As a key histone demethylase, lysine-specific demethylase 5B (KDM5B) demethylates lysine 4 of histone 3 (H3K4) and serves as a transcriptional repressor of certain tumor suppressor genes. Meanwhile, KDM5B inhibits STING-induced intrinsic immune response of tumor cells or recruits SETDB1 through non-enzymatic function to silence reverse transcription elements to promote immune escape. The conventional small molecule inhibitors can only inhibit the enzymatic function of KDM5B with no effect on the non-enzymatic function. In the article, we present the development of the first series of KDM5B degraders based on CPI-455 to inhibit the non-enzymatic function. Among them, GT-653 showed optimal KDM5B degradation efficiency in a ubiquitin proteasome-dependent manner. GT-653 efficiently reduced KDM5B protein levels without affecting KDM5B transcription. Interestingly, GT-653 increased H3K4me3 levels and activated the type-I interferon signaling pathway in 22RV1 cells without significant phenotypic response on cell proliferation.

Abstract 7270: Combination targeting of SKP2 and KDM5B induces senescence in castration-resistant prostate cancer cells via AKT signaling

Abstract Prostate cancer (PCa) is the second-leading cause of cancer mortalities and morbidities in the United States and is the most commonly diagnosed malignancy in men. Despite the fact that androgen deprivation therapy is the first-line option to initial responses, most PCa patients invariably develop castration-resistant prostate cancer (CRPC). CRPC is a lethal type of malignancy, therefore, novel and effective treatment strategies are needed. The goal of this study was to evaluate the combination treatment of small molecule inhibitors, SZL-P1-41, a SKP2 target and PBIT, a KDM5B target on PCa growth and progression; as well as to delineate the underlying mechanisms of suppressing CRPC. Literature reports that S-Phase Kinase Associated Protein 2 (SKP2) is upregulated in PCa and Lysine-specific demethylase 5B (KDM5B) serves as a histone demethylase with a crucial role in cancers. Studies showed that KDM5B is increased in human PCa and KDM5B knockout decreases carcinogenic properties of PCa cells. We previously reported that SKP2 loss partially decreases the growth of prostate tumors and that KDM5B levels are reversely regulated by SKP2 in PCa cells. However, the mechanisms of KDM5B and SKP2 interplay on PCa malignancy is unknown. We hypothesize that combination of PBIT and SZL-P1-41 treatment will enhance anti-cancer effects on PCa progression by inducing cellular senescence. Here, we showed that inhibition of KDM5B and SKP2 decreased the proliferation of PCa cells, and KDM5B KO cells were more vulnerable to SKP2 inhibition. More importantly, a combined inhibition of KDM5B and SKP2 significantly blocked malignant progression and migration of PCa cells. Mechanistically, combined inhibition of KDM5B and SKP2 in PCa cells abrogated AKT activation, resulting in an induction of cellular senescence, which was measured via Western blot analysis and senescence-associated β-galactosidase (SA-β-Gal) staining. Taken together, our results show that combined inhibition of KDM5B and SKP2 is more efficacious in inhibiting proliferation and migration in CRPC cells, and this regimen would be an ideal therapeutic approach for treating CRPC. Citation Format: LaKendria K. Brown, Thanigaivelan Kanagasabai, Guoliang Li, Sherly I. Celada, Zhenbang Chen. Combination targeting of SKP2 and KDM5B induces senescence in castration-resistant prostate cancer cells via AKT signaling [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2024; Part 1 (Regular Abstracts); 2024 Apr 5-10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2024;84(6_Suppl):Abstract nr 7270.

Deubiquitinase USP7 stabilizes KDM5B and promotes tumor progression and cisplatin resistance in nasopharyngeal carcinoma through the ZBTB16/TOP2A axis

Cisplatin-based chemotherapy improves the control of distant metastases in patients with nasopharyngeal carcinoma (NPC); however, around 30% of patients fail treatment due to acquired drug resistance. Epigenetic regulation is known to contribute to cisplatin resistance; nevertheless, the underlying mechanisms remain poorly understood. Here, we showed that lysine-specific demethylase 5B (KDM5B) was overexpressed and correlates with tumor progression and cisplatin resistance in patients with NPC. We also showed that specific inhibition of KDM5B impaired the progression of NPC and reverses cisplatin resistance, both in vitro and in vivo. Moreover, we found that KDM5B inhibited the expression of ZBTB16 by directly reducing H3K4me3 at the ZBTB16 promoter, which subsequently increased the expression of Topoisomerase II- α (TOP2A) to confer cisplatin resistance in NPC. In addition, we showed that the deubiquitinase USP7 was critical for deubiquitinating and stabilizing KDM5B. More importantly, the deletion of USP7 increased sensitivity to cisplatin by disrupting the stability of KDM5B in NPC cells. Therefore, our findings demonstrated that USP7 stabilized KDM5B and promoted cisplatin resistance through the ZBTB16/TOP2A axis, suggesting that targeting KDM5B may be a promising cisplatin-sensitization strategy in the treatment of NPC.

MicroRNA-93-5p regulates odontogenic differentiation and dentin formation via KDM6B

BackgroundEpigenetic factors influence the odontogenic differentiation of dental pulp stem cells and play indispensable roles during tooth development. Some microRNAs can epigenetically regulate other epigenetic factors like DNA methyltransferases and histone modification enzymes, functioning as epigenetic-microRNAs. In our previous study, microarray analysis suggested microRNA-93-5p (miR-93-5p) was differentially expressed during the bell stage in human tooth germ. Prediction tools indicated that miR-93-5p may target lysine-specific demethylase 6B (KDM6B). Therefore, we explored the role of miR-93-5p as an epi-miRNA in tooth development and further investigated the underlying mechanisms of miR-93-5p in regulating odontogenic differentiation and dentin formation.MethodsThe expression pattern of miR-93-5p and KDM6B of dental pulp stem cells (DPSCs) was examined during tooth development and odontogenic differentiation. Dual luciferase reporter and ChIP-qPCR assay were used to validate the target and downstream regulatory genes of miR-93-5p in human DPSCs (hDPSCs). Histological analyses and qPCR assays were conducted for investigating the effects of miR-93-5p mimic and inhibitor on odontogenic differentiation of hDPSCs. A pulpotomy rat model was further established, microCT and histological analyses were performed to explore the effects of KDM6B-overexpression and miR-93-5p inhibition on the formation of tertiary dentin.ResultsThe expression level of miR-93-5p decreased as odontoblast differentiated, in parallel with elevated expression of histone demethylase KDM6B. In hDPSCs, miR-93-5p overexpression inhibited the odontogenic differentiation and vice versa. MiR-93-5p targeted 3′ untranslated region (UTR) of KDM6B, thereby inhibiting its protein translation. Furthermore, KDM6B bound the promoter region of BMP2 to demethylate H3K27me3 marks and thus upregulated BMP2 transcription. In the rat pulpotomy model, KDM6B-overexpression or miR-93-5p inhibition suppressed H3K27me3 level in DPSCs and consequently promoted the formation of tertiary dentin.ConclusionsMiR-93-5p targets epigenetic regulator KDM6B and regulates H3K27me3 marks on BMP2 promoters, thus modulating the odontogenic differentiation of DPSCs and dentin formation.

Upregulation of KDM6B in the anterior cingulate cortex contributes to neonatal maternal deprivation-induced chronic visceral pain in mice.

Irritable bowel syndrome (IBS) is a prevalent functional gastrointestinal disease characterized by chronic visceral pain with a complex etiology and challenging treatment. Although accumulating evidence supports the involvement of central nervous system sensitization in the development of visceral pain, the precise molecular mechanisms remain incompletely understood. In this study, we highlight the critical regulatory role of lysine-specific demethylase 6B (KDM6B) in the anterior cingulate cortex (ACC) in chronic visceral pain. To simulate clinical IBS conditions, we utilized the neonatal maternal deprivation (NMD) mouse model. Our results demonstrated that NMD induced chronic visceral pain and anxiety-like behaviors in mice. Notably, the protein expression level of KDM6B significantly increased in the ACC of NMD mice, leading to a reduction in the expression level of H32K7me3. Immunofluorescence staining revealed that KDM6B primarily co-localizes with neurons in the ACC, with minimal presence in microglia and astrocytes. Injecting GSK-J4 (a KDM6B-specific inhibitor) into ACC of NMD mice, resulted in a significant alleviation in chronic visceral pain and anxiety-like behaviors, as well as a remarkable reduction in NR2B expression level. ChIP assay further indicated that KDM6B regulates NR2B expression by influencing the demethylation of H3K27me3. In summary, our findings underscore the critical role of KDM6B in regulating chronic visceral pain and anxiety-like behaviors in NMD mice. These insights provide a basis for further understanding the molecular pathways involved in IBS and may pave the way for targeted therapeutic interventions.

Entecavir: A Review and Considerations for Its Application in Oncology.

Entecavir (ETV) is a drug used as a first-line treatment for chronic hepatitis B (CHB) virus infection because it is a guanosine nucleoside analogue with activity against the hepatitis B virus polymerase. The ETV dosage can range from 0.5 mg to 1 mg once a day and the most common side effects include headache, insomnia, fatigue, dizziness, somnolence, vomiting, diarrhea, nausea, dyspepsia, and increased liver enzyme levels. In addition to its conventional use, ETV acts as an inhibitor of lysine-specific demethylase 5B (KDM5B), an enzyme that is overexpressed in breast, lung, skin, liver, and prostate tumors and is involved in the hormonal response, stem cell regeneration, genomic stability, cell proliferation, and differentiation. The KDM5B enzyme acts as a transcriptional repressor in tumor suppressor genes, silencing them, and its overexpression leads to drug resistance in certain tumor types. Furthermore, the literature suggests that KDM5B activates the PI3K/AKT signaling pathway, while reducing KDM5B expression decreases AKT signaling, resulting in decreased tumor cell proliferation. In silico studies have demonstrated that ETV can inhibit tumor cell proliferation and induce apoptosis by reducing KDM5B expression. ETV also appears to inhibit PARP-1, has a high genetic barrier, reducing the chance of resistance development, and can also prevent the reactivation of the hepatitis B virus in cancer patients, which have proven to be significant advantages regarding its use as a repurposed drug in oncology. Therefore, ETV holds promise beyond its original therapeutic indication.

DDDR-22. PREDICTING AND TARGETING CLONALLY EXPANDING, TMZ-RESISTANT TUMOR CELLS IN GLIOBLASTOMA

Abstract Emerging evidence supports the notion that phenotypic plasticity contributes to disease progression and drug resistance in malignant glioma. We have recently described a rare population of ALDH1A1+ tumor cells in newly diagnosed, treatment-naive glioblastoma that can adapt to the exposure of the standard chemotherapeutic temozolomide (TMZ). Their subclonal growth leads to AKT-driven, TMZ-resistant cellular hierarchies. Accumulation of ALDH1A1+/pAKT+ cells can therefore be noted subsequent to TMZ in patient relapse tissue and in PDX models of disease. We have also shown that this series of events requires a sequential targeting approach where these subclones are allowed to enrich under TMZ and, only in a second step, are treated with AKT inhibitors. This “enrich and kill” strategy doubles the TMZ-based survival benefit in preclinical PDX models (Kebir et al., Clin Cancer Res 2023). Here, we took advantage of short-term expanded patient-derived cell cultures, which allow the study of early stages of this type of adaptive plasticity in controlled conditions. Specifically, we characterized the human lysine-specific demethylase 5B (KDM5B) as a prospective indicator for subclonal expansion in rare cells under first-time exposure to TMZ. We used genetic reporters, pharmacological interference, CHIP-seq analysis and cellular barcoding to investigate the dynamics of KDM5B expression and the related intracellular cross-signaling. We monitored patient cell samples over prolonged periods of time, and we found that KDM5Bhigh treatment-naive glioblastoma cells preferentially contribute to the dynamics of ALDH1A1 subclones and drug resistance under the influence of TMZ. These findings may lay ground for the development of biomarker-assisted clinical trials. This work is supported by DFG/GRC-CRU337/2 (proj#405344257).

Sensory neuron-specific long noncoding RNA in small non-peptidergic dorsal root ganglion neurons selectively impairs nerve injury-induced mechanical hypersensitivity

AimsNerve injury-induced mechanical hypersensitivity is one of major clinical symptoms in neuropathic pain patients. Understanding molecular mechanisms underlying this symptom is crucial for developing effective therapies. The present study was to investigate whether sensory neuron-specific long noncoding RNA (SS-lncRNA) predominantly expressed in small non-peptidergic dorsal root ganglion (DRG) neurons repaired nerve injury-induced mechanical hypersensitivity. Materials and methodsSS-lncRNA downregulation in the mas-related G protein-coupled receptor member D (Mrgprd)-expressed DRG neurons was rescued and mimicked by crossbreeding MrgprdCreERT2/+ lines with Rosa26SS-lncRNA knock-in mice and SS-lncRNAfl/fl mice, respectively, followed by tamoxifen injection. Key findingsRescuing SS-lncRNA downregulation in the Mrgprd-expressed DRG neurons significantly reversed the spinal nerve ligation (SNL)-induced reduction of the calcium-activated potassium channel subfamily N member 1 (KCNN1) in these DRG neurons and alleviated the SNL-induced mechanical hypersensitivity, without affecting the SNL-induced heat and cold nociceptive hypersensitivities, on the ipsilateral side. Conversely, mimicking SS-lncRNA downregulation in the Mrgprd-expressed DRG neurons reduced basal KCNN1 expression in these DRG neurons and produced the enhanced response to mechanical stimulation, but not thermal and cold stimuli, on bilateral sides. Mechanistically, SS-lncRNA downregulation caused a reduction in its binding to lysine-specific demethylase 6B (KDM6B) and consequent recruitment of less KDM6B to Kcnn1 promoter and an increase of H3K27me3 enrichment in this promoter in injured DRG. SignificanceOur findings suggest that SS-lncRNA downregulation in small non-peptidergic sensory neurons is required specifically for nerve injury-induced mechanical hypersensitivity likely through silencing KCNN1 expression caused by KDM6B-gated increase of H3K27me3 enrichment in Kcnn1 promoter in these neurons.

Upregulation of lysine-specific demethylase 6B aggravatesinflammatory pain through H3K27me3 demethylation-dependent production of TNF-α in the dorsal root ganglia and spinal dorsal horn in rats.

Lysine-specific demethylase 6B (KDM6B) serves as a key mediator of gene transcription. It regulates expression of proinflammatory cytokines and chemokines in variety of diseases. Herein, the role and the underlying mechanisms of KDM6B in inflammatory pain were studied. The inflammatory pain was conducted by intraplantar injection of complete Freund's adjuvant (CFA) in rats. Immunofluorescence, Western blotting, qRT-PCR, and chromatin immunoprecipitation (ChIP)-PCR were performed to investigate the underlying mechanisms. CFA injection led to upregulation of KDM6B and decrease in the level of H3K27me3 in the dorsal root ganglia (DRG) and spinal dorsal horn. The mechanical allodynia and thermal hyperalgesia following CFA were alleviated by the treatment of intrathecal injection of GSK-J4, and by microinjection of AAV-EGFP-KDM6B shRNA in the sciatic nerve or in lumbar 5 dorsal horn. The increased production of tumor necrosis factor-α (TNF-α) following CFA in the DRGs and dorsal horn was inhibited by these treatments. ChIP-PCR showed that CFA-induced increased binding of nuclear factor κB with TNF-α promoter was repressed by the treatment of microinjection of AAV-EGFP-KDM6B shRNA. These results suggest that upregulated KDM6B via facilitating TNF-α expression in the DRG and spinal dorsal horn aggravates inflammatory pain.

MiR-29c-3p Accelerates Mucosal Injury in Dextran Sodium Sulfate-induced Ulcerative Colitis Mice through the KDM6B/ H3K27me3/LDHA axis.

Ulcerative colitis (UC) is an inflammatory intestinal disorder featured by mucosal injury. MicroRNAs (miRNAs) play a role in the pathogenesis underlying UC. This study was conducted to investigate the role of miR-29c-3p in a dextran sodium sulfate (DSS)-induced UC mouse model and provide targets for UC treatment. The UC mouse model was established by DSS induction. The expression levels of miR-29c-3p, lysine-specific demethylase 6B (KDM6B), zonula occludens-1 (ZO-1), Occludin, and lactate dehydrogenase A (LDHA) were detected by real-time quantitative polymerase chain reaction or Western blot assays. The mucosal injury was evaluated by disease activity index (DAI), colon length, Hematoxylin-Eosin staining, and fluorescein isothiocyanate-glucan permeability test. The binding between miR-29c-3p and KDM6B and the occupation of KDM6B or trimethylated H3 lysine 27 (H3K27me3) on the LDHA promoter were analyzed by the dual-luciferase and chromatin-immunoprecipitation assays. miR-29c-3p was downregulated while KDM6B and LDHA were upregulated in DSS mice. miR-29c-3p overexpression reduced DAI and inflammatory cell infiltration while increasing colon length, intestinal permeability, and levels of ZO-1 and Occludin. miR-29c-3p inhibited KDM6B expression and increased H3K27me3 occupation on the LDHA promoter, thus inhibiting LDHA transcription. Overexpression of KDM6B or LDHA averted the protective role of miR-29c-3p upregulation in mucosal injury. miR-29c-3p limited KDM6B expression and increased the H3K27me3 occupation on the LDHA promoter to enhance LDHA transcription, moderating mucosal injury and delaying UC progression.

Histone demethylase KDM5B licenses macrophage-mediated inflammatory responses by repressing Nfkbia transcription.

Macrophages play a critical role in the immune homeostasis and host defense against invading pathogens. However, uncontrolled activation of inflammatory macrophages leads to tissue injury and even fuels autoimmunity. Hence the molecular mechanisms underlying macrophage activation need to be further elucidated. The effects of epigenetic modifications on the function of immune cells draw increasing attention. Here, we demonstrated that lysine-specific demethylase 5B (KDM5B), a classical transcriptional repressor in stem cell development and cancer, was required for the full activation of NF-κB signaling cascade and pro-inflammatory cytokine production in macrophages. KDM5B deficiency or inhibitor treatment protected mice from immunologic injury in both collagen-induced arthritis (CIA) model and endotoxin shock model. Genome-wide analysis of KDM5B-binding peaks identified that KDM5B was selectively recruited to the promoter of Nfkbia, the gene encoding IκBα, in activated macrophages. KDM5B mediated the H3K4me3 modification erasing and decreased chromatin accessibility of Nfkbia gene locus, coordinating the elaborate suppression of IκBα expression and the enhanced NF-κB-mediated macrophage activation. Our finding identifies the indispensable role of KDM5B in macrophage-mediated inflammatory responses and provides a candidate therapeutic target for autoimmune and inflammatory disorders.

Dual-Targeted Nanodiscs Revealing the Cross-Talk between Osteogenic Differentiation of Mesenchymal Stem Cells and Macrophages.

Ongoing research has highlighted the significance of the cross-play of macrophages and mesenchymal stem cells (MSCs). Lysine-specific demethylase 6B (KDM6B) has been shown to control osteogenic differentiation of MSCs by depleting trimethylated histone 3 lysine 27 (H3K27me3). However, to date, the role of KDM6B in bone marrow-derived macrophages (BMDMs) remains controversial. Here, a chromatin immunoprecipitation assay (ChIP) proved that KDM6B derived from osteogenic-induced BMSCs could bind to the promoter region of BMDMs' brain and muscle aryl hydrocarbon receptor nuclear translocator-like protein-1 (BMAL1) gene in a coculture system and activate BMAL1. Transcriptome sequencing and experiments in vitro showed that the overexpression of BMAL1 in BMDM could inhibit the TLR2/NF-κB signaling pathway, reduce pyroptosis, and decrease the M1/M2 ratio, thereby promoting osteogenic differentiation of BMSCs. Furthermore, bone and macrophage dual-targeted GSK-J4 (KDM6B inhibitor)-loaded nanodiscs were synthesized via binding SDSSD-apoA-1 peptide analogs (APA) peptide, which indirectly proved the critical role of KDM6B in osteogenesis in vivo. Overall, we demonstrated that KDM6B serves as a positive circulation trigger during osteogenic differentiation by decreasing the ratio of M1/M2 both in vitro and in vivo. Collectively, these results provide insight into basic research in the field of osteoporosis and bone repair.

Emodin inhibits bladder inflammation and fibrosis in mice with interstitial cystitis by regulating JMJD3.

Interstitial cystitis/bladder pain syndrome (IC/BPS) is a devastating urological chronic pelvic pain condition. In search of a potential treatment, we investigated the effect of emodin on IC/BPS inflammation and fibrosis, and explore the potential mechanism. An experimental model of interstitial cystitis was induced by cyclophosphamide, and human bladder smooth muscle cells were treated with lipopolysaccharide to establish the cell model in vitro. In both models, inflammation- and fibrosis-related indexes were measured after emodin administration. Furthermore, the specific antagonists were used to dig for the mechanisms underlying the response to emodin treatment. Emodin significantly ameliorated management of cystitis, reduced the amount of inflammatory cytokines (tumor necrosis factor-α, monocyte chemoattractant protein-1, interleukin-1β, interleukin-8, and interleukin-6) in models, as well as reducing the synthesis of fibrosis marker including collagen1, collagen3, vimentin, fibronectin and α-smooth muscle actin. Further mechanism studies demonstrated that emodin inhibited inflammatory reaction and fibrosis through blocking lysine-specific demethylase 6B (JMJD3) expression via JAK/STAT, NF-κB and TGF-β/SMAD pathways. Our study reveals the critical role of emodin-JMJD3 signaling in interstitial cystitis by regulating inflammation, fibrosis, and extracellular matrix deposition in cells and tissues, and these findings provide an avenue for effective treatment of patients with cystitis.

KDM6B promotes gastric carcinogenesis and metastasis via upregulation of CXCR4 expression

KDM6B (Lysine-specific demethylase 6B) is a histone lysine demethyltransferase that plays a key role in many types of cancers. However, its potential role in gastric cancer (GC) remains unclear. Here, we focused on the clinical significance and potential role of KDM6B in GC. We found that the KDM6B expression is upregulated in GC tissues and that its high expression in patients is related to poor prognosis. KDM6B ectopic expression promotes GC cells’ proliferation and metastasis, while its inhibition has opposite effects in vitro and in vivo. Mechanistically, KDM6B promotes GC cells proliferation and metastasis through its enzymatic activity through the induction of H3K27me3 demethylation near the CXCR4 (C-X-C chemokine receptor type 4) promoter region, resulting in the upregulation of CXCR4 expression. Furthermore, H. pylori was found to induce KDM6B expression. In conclusion, our results suggest that KDM6B is aberrantly expressed in GC and plays a key role in gastric carcinogenesis and metastasis through CXCR4 upregulation. Our work also suggests that KDM6B may be a potential oncogenic factor and a therapeutic target for GC.

Discovery of Novel Pyrazole-Based KDM5B Inhibitor TK-129 and Its Protective Effects on Myocardial Remodeling and Fibrosis

Lysine-specific demethylase 5B (KDM5B) has been recognized as a potential drug target for cardiovascular diseases. In this work, we first found that the KDM5B level was increased in mouse hearts after transverse aortic constriction (TAC) and in Ang II-induced activated cardiac fibroblasts. Structure-based design and further optimizations led to the discovery of highly potent pyrazole-based KDM5B inhibitor TK-129 (IC50 = 0.044 μM). TK-129 reduced Ang II-induced activation of cardiac fibroblasts in vitro, exhibited good PK profile (F = 42.37%), and reduced isoprenaline-induced myocardial remodeling and fibrosis in vivo. Mechanistically, we found that KDM5B up-regulation in cardiac fibroblast activation was associated with the activation of Wnt-related pathway. The protective effects of TK-129 were associated with its KDM5B inhibition and blocking KDM5B-related Wnt pathway activation. Taken together, TK-129 may represent a novel KDM5-targeting lead compound for cardiac remodeling and fibrosis.

KDM5B regulates the PTEN/PI3K/Akt pathway to increase sorafenib-resistance in hepatocellular carcinoma.

Lysine-specific demethylase 5B (KDM5B) exerts its tumor-promoting functions in numerous malignancies, although the possible mechanisms by which KDM5B promotes cancer aggressiveness in hepatocellular carcinoma (HCC) have been preliminarily explored, the role of this gene in regulating sorafenib-resistance in HCC has not been studied. Thus, the present study was designed to resolve this problem, and our data suggested that KDM5B was significantly upregulated in the HCC tissues collected from patients with sorafenib treatment history. Consistently, continuous low-dose sorafenib administration increased KDM5B expression levels in the sorafenib-resistant HCC cells compared to their sorafenib-sensitive counterparts. Next, by performing the functional experiments, we found that KDM5B positively regulated sorafenib-resistance and cancer stem cell (CSC) properties in HCC cells in vitro and in vivo . Furthermore, upregulation of KDM5B-degraded phosphatase and tensin homolog (PTEN), results in the activation of the downstream oncogenic PI3K/Akt pathway. Subsequently, the rescuing experiments verified that the promoting effects of KDM5B overexpression on chemoresistance and cancer stemness in HCC cells were all abrogated by PI3K (p110) knockdown and PTEN overexpression. Collectively, those data hinted that KDM5B influenced CSC properties and sorafenib-resistance in HCC cells through modulating the PTEN/PI3K/Akt pathway, and KDM5B could be used as a potential target for the treatment of HCC in clinic.

Characterization of 2,2',4,4'-tetrabromodiphenyl ether (BDE47)-induced testicular toxicity via single-cell RNA-sequencing.

BackgroundThe growing male reproductive diseases have been linked to higher exposure to certain environmental compounds such as 2,2′,4,4′-tetrabromodiphenyl ether (BDE47) that are widely distributed in the food chain. However, the specific underlying molecular mechanisms for BDE47-induced male reproductive toxicity are not completely understood.MethodsHere, for the first time, advanced single-cell RNA sequencing (ScRNA-seq) was employed to dissect BDE47-induced prepubertal testicular toxicity in mice from a pool of 76 859 cells.ResultsOur ScRNA-seq results revealed shared and heterogeneous information of differentially expressed genes, signaling pathways, transcription factors, and ligands-receptors in major testicular cell types in mice upon BDE47 treatment. Apart from disruption of hormone homeostasis, BDE47 was discovered to downregulate multiple previously unappreciated pathways such as double-strand break repair and cytokinesis pathways, indicative of their potential roles involved in BDE47-induced testicular injury. Interestingly, transcription factors analysis of ScRNA-seq results revealed that Kdm5b (lysine-specific demethylase 5B), a key transcription factor required for spermatogenesis, was downregulated in all germ cells as well as in Sertoli and telocyte cells in BDE47-treated testes of mice, suggesting its contribution to BDE47-induced impairment of spermatogenesis.ConclusionsOverall, for the first time, we established the molecular cell atlas of mice testes to define BDE47-induced prepubertal testicular toxicity using the ScRNA-seq approach, providing novel insight into our understanding of the underlying mechanisms and pathways involved in BDE47-associated testicular injury at a single-cell resolution. Our results can serve as an important resource to further dissect the potential roles of BDE47, and other relevant endocrine-disrupting chemicals, in inducing male reproductive toxicity.