Protein lysine β-hydroxybutyrylation (Kbhb) is a newly discovered post-translational modification associated with a wide range of biological processes. Identifying Kbhb sites is critical for a better understanding of its mechanism of action. However, biochemical experimental methods for probing Kbhb sites are costly and have a long cycle. Therefore, a feature embedding learning method based on the Transformer encoder was proposed to predict Kbhb sites. In this method, amino acid residues were mapped into numerical vectors according to their amino acid class and position in a learnable feature embedding method. Then the Transformer encoder was used to extract discriminating features, and the bidirectional long short-term memory network (BiLSTM) was used to capture the correlation between different features. In this paper, a benchmark dataset was constructed, and a Kbhb site predictor, AutoTF-Kbhb, was implemented based on the proposed method. Experimental results showed that the proposed feature embedding learning method could extract effective features. AutoTF-Kbhb achieved an area under curve (AUC) of 0.87 and a Matthews correlation coefficient (MCC) of 0.37 on the independent test set, significantly outperforming other methods in comparison. Therefore, AutoTF-Kbhb can be used as an auxiliary means to identify Kbhb sites.
Protein Processing, Post-Translational ; Lysine/chemistry* ; Proteins/chemistry* ; Machine Learning ; Algorithms

OBJECTIVES: To summarize the clinical and genetic characteristics of epilepsy with intellectual disability caused by SETD1B gene variants in children. METHODS: A retrospective analysis was conducted on the clinical data of three children with SETD1B gene variants diagnosed and treated at the Department of Pediatric Neurology of Xiangya Hospital of Central South University. Relevant literature was reviewed to summarize the clinical characteristics of this condition. RESULTS: All three children presented with symptoms during infancy or early childhood, including mild intellectual disability and myoclonic seizures, with two cases exhibiting eyelid myoclonia. After treatment with three or more antiepileptic drugs, two cases achieved seizure control or partial control, while one case remained refractory. Each of the three children was found to have a heterozygous variant in the SETD1B gene (one deletion, one frameshift, and one missense variant). To date, 54 cases with SETD1B gene variants have been reported, involving a total of 56 variants, predominantly missense variants (64%, 36/56). The main clinical manifestations included varying degrees of developmental delay (96%, 52/54) and seizures (81%, 44/54). Among the 44 patients with seizures, myoclonic (20%, 9/44) and absence seizures (34%, 15/44) were common, with eyelid myoclonia reported in six cases. Approximately one-fifth of these patients had poorly controlled seizures. CONCLUSIONS The primary phenotypes associated with SETD1B gene variants are intellectual disability and seizures, and seizures exhibit distinct characteristics. Eyelid myoclonia is not uncommon.
Humans ; Intellectual Disability/complications* ; Epilepsy/complications* ; Male ; Female ; Histone-Lysine N-Methyltransferase/genetics* ; Child, Preschool ; Child ; Retrospective Studies

OBJECTIVE: To explore the role of nuclear receptor-binding SET-domain protein 1 (NSD1) in the pathogenesis of nonobstructive azoospermia (NOA) by regulating the expressions of relevant genes. METHODS: We detected the expression of NSD1 in the testis tissue of 7 male patients with obstructive azoospermia (OA) and 18 with NOA by qPCR and immunofluorescence assay, and determined the modification level of H3K36me2 in the testes of two groups of patients by immunofluorescence staining, Western blot and immunoprecipitation (IP). We examined the difference in the enrichment of H3K36me2 in the testis tissue by chromatin IP-based sequencing (ChIP-Seq), analyzed the genomic distribution and target genes using bioinformatics, and verified the expression levels of the target genes in the testes of the two groups of patients by qPCR. RESULTS: Compared with the patients with OA, those with NOA showed dramatically decreased mRNA and protein expressions of NSD1 (P=0.000 8). The binding of NSD1 to H3K36me2 was observed in the testis tissue of both the two groups of patients, while the modification level of H3K36me2 was evidently reduced in the NOA males. H3K36me2 was distributed mainly in the intergenic region in the testes of the two groups of patients, but the enrichment of H3K36me2 was obviously decreased in the NOA group. The differentially H3K36me2-enriched genes were involved in various biological processes, including tissue development, and cell morphogenesis. Results of ChIP-Seq and qPCR showed significantly down-regulated expressions of the target genes KIT, SPO11 and ACRV1 in the testis tissue of the NOA males compared with those in the OA patients (P<0.01). CONCLUSION The levels of NSD1 and H3K36me2 are decreased in testis tissue of the NOA patient, H3K36me2 is highly enriched in the spermatogenesis-related key genes KIT, SPO11 and ACRV1, and the down-regulated expression of NSD1 impairs spermatogenesis.
Humans ; Male ; Azoospermia/genetics* ; Testis/metabolism* ; Histone-Lysine N-Methyltransferase/metabolism* ; Histones/metabolism*

OBJECTIVE: To explore the specific mechanism of histone deacetylase 2 (HDAC2) mediated histone H3 lysine 27 acetylation (H3K27ac) modification in promoting the proliferation and migration of hepatocellular carcinoma cells. METHODS: Samples of 40 cases of hepatocellular carcinoma and paracancerous tissues resected from January 2021 to January 2023 were collected. The expressions of HDAC2 and H3K27ac in hepatocellular carcinoma, paracancerous tissues and cell lines were detected by immunohistochemistry and Western blotting. The correlation between the expression levels of HDAC2 and H3K27ac and the relationship between HDAC2 expression and clinicopathological characteristics of patients with hepatocellular carcinoma were analyzed. The proliferation, migration and invasion of Hep3B and HepG2 cells were determined by MTS, clone formation, scratch and Transwell experiments. The acetylation of H3K27 mediated by HDAC2 was verified by Western blotting, real-time fluorescence quantitative PCR (qRT-PCR) and chromatin immunoprecipitation high-throughput sequencing (ChIP-seq). In vivo xenotransplantation experiment, the tumorigenicity of cells in each group was measured, and the expression of proteins related to phosphoinositide 3-kinases/phosphatase and tensin homolog deleted on chromosome ten/protein kinase B/mammalian target of rapamycin (PI3K/PTEN/AKT/mTOR) signal pathway was detected. RESULTS: High expression of HDAC2 and low expression of H3K27ac were found in hepatocellular carcinoma tissues and cell lines (P < 0.05), and there was a negative correlation between them (r=-0.477, P=0.002). The expression of HDAC2 was related to tumor size, hepatitis B virus infection, TNM stage and portal vein tumor thrombus (P < 0.05). Compared with the sh-NC group of Hep3B and HepG2 cells, the proliferation, clone formation, migration and invasion ability of sh-HDAC2 group were decreased (P < 0.05). Compared with the Empty group, the HDAC2 group exhibited increased expression levels and activity of HDAC2, as well as enhanced cell proliferation, clone formation, migration, invasion ability, tumor volume and mass in vivo, and elevated expression levels of p-PI3K, p-AKT, and p-mTOR (P < 0.05). Conversely, the enrichment and expression levels of H3K27ac, along with the expression level of PTEN, were decreased (P < 0.05). In the iHDAC2 group, the expression levels and activity of HDAC2, as well as the proliferation, clone formation, migration, invasion ability, tumor volume and mass in vivo, and expression levels of p-PI3K, p-AKT, and p-mTOR were reduced (P < 0.05). Additionally, the expression levels of H3K27ac and PTEN were increased (P < 0.05). To validate the involvement of the PI3K/PTEN/AKT/mTOR signaling pathway in HDAC2-mediated regulation of malignant behaviors in liver cancer cells through H3K27ac, the PI3K activator 740Y-P was introduced. Compared with the iHDAC2 group, the iHDAC2+740Y-P group exhibited increased proliferation, clone formation, migration, invasion ability, tumor volume and mass in vivo, and elevated expression levels of p-PI3K, p-AKT, and p-mTOR (P < 0.05). Conversely, the expression level of PTEN was decreased (P < 0.05). CONCLUSION HDAC2 initiates PI3K/PTEN/AKT/mTOR signal pathway by mediating H3K27 acetylation, which promotes the occurrence and development of hepatocellular carcinoma.
Humans ; Carcinoma, Hepatocellular/metabolism* ; Liver Neoplasms/metabolism* ; Histone Deacetylase 2/physiology* ; Cell Proliferation ; Acetylation ; Cell Movement ; Histones/metabolism* ; Animals ; Hep G2 Cells ; Male ; Female ; Mice ; Cell Line, Tumor ; Signal Transduction ; Mice, Nude ; PTEN Phosphohydrolase/metabolism* ; Lysine/metabolism* ; Middle Aged

The nod-like receptor family pyrin domain containing 3 (NLRP3) inflammasome plays a crucial role in the prognosis of subarachnoid hemorrhage (SAH). WNK1 kinase negatively regulates NLRP3 in various inflammatory conditions, but its role in early brain injury (EBI) after SAH remains unclear. In this study, we used an in vivo SAH model in rats/mice and AAV-WNK1 intraventricular injection to investigate its neuroprotective mechanisms. WNK1 expression was significantly reduced in SAH patient blood and SAH model brain tissue, correlating negatively with microglial activation. AAV-WNK1 alleviated brain edema, neuronal necrosis, behavioral deficits, and inflammation by inhibiting NLRP3 inflammasome activation. In hemin-stimulated BV-2 cells, WNK1 overexpression reduced NLRP3 activation and inflammatory cytokines. Chloride counteracted WNK1's inhibitory effects, and WNK1 suppressed P2X7R-induced NLRP3 activation. Mechanistically, WNK1 functioned via the OXSR1/STK39 pathway. These findings highlight WNK1 as a key regulator of intracellular chloride balance and neuroinflammation, presenting a potential therapeutic target for SAH treatment.
Animals ; NLR Family, Pyrin Domain-Containing 3 Protein/metabolism* ; Subarachnoid Hemorrhage/complications* ; Inflammasomes/metabolism* ; Rats ; Mice ; Neuroinflammatory Diseases/metabolism* ; WNK Lysine-Deficient Protein Kinase 1/genetics* ; Male ; Humans ; Chlorides/metabolism* ; Mice, Inbred C57BL ; Rats, Sprague-Dawley ; Brain Injuries/metabolism* ; Microglia/metabolism* ; Protein Serine-Threonine Kinases

Stem cells play a crucial role in maintaining tissue regenerative capacity and homeostasis. However, mechanisms associated with stem cell senescence require further investigation. In this study, we conducted a proteomic analysis of human dental pulp stem cells (HDPSCs) obtained from individuals of various ages. Our findings showed that the expression of NUP62 was decreased in aged HDPSCs. We discovered that NUP62 alleviated senescence-associated phenotypes and enhanced differentiation potential both in vitro and in vivo. Conversely, the knocking down of NUP62 expression aggravated the senescence-associated phenotypes and impaired the proliferation and migration capacity of HDPSCs. Through RNA-sequence and decoding the epigenomic landscapes remodeled induced by NUP62 overexpression, we found that NUP62 helps alleviate senescence in HDPSCs by enhancing the nuclear transport of the transcription factor E2F1. This, in turn, stimulates the transcription of the epigenetic enzyme NSD2. Finally, the overexpression of NUP62 influences the H3K36me2 and H3K36me3 modifications of anti-aging genes (HMGA1, HMGA2, and SIRT6). Our results demonstrated that NUP62 regulates the fate of HDPSCs via NSD2-dependent epigenetic reprogramming.
Humans ; Dental Pulp/cytology* ; Nuclear Pore Complex Proteins/genetics* ; Cellular Senescence/genetics* ; Stem Cells/metabolism* ; Epigenesis, Genetic ; Cell Proliferation ; Cell Differentiation ; Histone-Lysine N-Methyltransferase/metabolism* ; Cells, Cultured ; Cellular Reprogramming ; Cell Movement ; Proteomics

Successful cloning through somatic cell nuclear transfer (SCNT) faces significant challenges due to epigenetic obstacles. Recent studies have highlighted the roles of H3K4me3 and H3K27me3 as potential contributors to these obstacles. However, the underlying mechanisms remain largely unclear. In this study, we generated genome-wide maps of H3K4me3 and H3K27me3 in mouse pre-implantation NT embryos. Our analysis revealed that aberrantly over-represented broad H3K4me3 domain and H3K27me3 signal lead to increased bivalent marks at gene promoters in NT embryos compared with naturally fertilized (NF) embryos at the 2-cell stage, which may link to relatively low levels of H3K36me3 in NT 2-cell embryos. Notably, the overexpression of Setd2, a H3K36me3 methyltransferase, successfully restored multiple epigenetic marks, including H3K36me3, H3K4me3, and H3K27me3. In addition, it reinstated the expression levels of ZGA-related genes by reestablishing H3K36me3 at gene body regions, which excluded H3K27me3 from bivalent promoters, ultimately improving cloning efficiency. These findings highlight the excessive bivalent state at gene promoters as a potent barrier and emphasize the removal of these barriers as a promising approach for achieving higher cloning efficiency.
Animals ; Mice ; Histone-Lysine N-Methyltransferase/biosynthesis* ; Histones/genetics* ; Nuclear Transfer Techniques ; Female ; Gene Expression Regulation, Developmental ; Promoter Regions, Genetic ; Epigenesis, Genetic ; Embryo, Mammalian/metabolism*

The p60 subunit of the chromatin assembly factor-1 complex, that is, chromatin assembly factor-1 subunit B (CHAF1B), is a histone H3/H4 chaperone crucial for the transcriptional regulation of cell differentiation and self-renewal. CHAF1B is overexpressed in several cancers and may represent a potential target for cancer therapy. However, its expression and clinical significance in lung squamous-cell carcinoma (LUSC) remain unclear. In this study, we performed weighted gene correlation network analysis to analyze the Gene Expression Omnibus GSE68793 LUSC dataset and identified CHAF1B as one of the most important driver gene candidates. Immunohistochemical analysis of 126 LUSC tumor samples and 80 adjacent normal lung tissues showed the marked upregulation of CHAF1B in tumor tissues and the negative association of its expression level with patient survival outcomes. Silencing of CHAF1B suppressed LUSC proliferation in vitro and LUSC tumor growth in vivo. Furthermore, bulk RNA sequencing of CHAF1B knockdown cells indicated SET domain containing 7 (SETD7) as a significant CHAF1B target gene. In addition, CHAF1B competitively binds to the SETD7 promoter region and represses its transcription. Altogether, these results imply that CHAF1B plays a vital role in LUSC tumorigenesis and may represent a potential molecular target for this deadly disease.
Humans ; Lung Neoplasms/metabolism* ; Histone-Lysine N-Methyltransferase/metabolism* ; Carcinoma, Squamous Cell/metabolism* ; Gene Expression Regulation, Neoplastic ; Disease Progression ; Cell Proliferation/genetics* ; Cell Line, Tumor ; Chromatin Assembly Factor-1/metabolism* ; Animals ; Mice ; Male ; Female

Objective To investigate the effects of folate deficiency on changes in histone H3 lysine 4 (H3K4) mono-methylation (me1)-marked enhancers and the molecular mechanism underpinning the folate deficiency-induced neural tube defects (NTD). Methods Mouse embryonic stem cells (mESCs) were cultured in the folate-free DMEM medium (folate-deficient group) and the DMEM medium containing 4 mg/L folate (normal control group),respectively.Chromatin immunoprecipitation sequencing (ChIP-seq) was performed for H3K4me1. The mouse model of folate-induced NTD was established,and transcriptome sequencing (RNA-seq) was performed for the brain tissue of fetal mice to reveal the differential expression profiles.The results were validated through real-time quantitative polymerase chain reaction (RT-qPCR).The activity of the differential peak regions of H3K4me1 was verified through the luciferase reporter assay. Results The folate content in the mESCs cultured in the folate-free medium reduced compared with that in the normal control group (P=0.008).The H3K4me1-maked enhancers in the mESCs cultured in the folate-free medium induced significant changes in intronic regions,and these changes were concentrated in metabolic and energy metabolism processes (q=9.56×10^-48,P=1.28×10^-47).The differentially expressed genes harboring H3K4me1-marked enhancers in mESCs were mainly enriched in the Wnt signaling pathway (q=0.004,P=0.004 7).ChIP-qPCR results confirmed that H3K4me1 binding decreased in the differential peak regions of the Ldlrap1 gene (P=0.008),Camta1 gene (P=0.002),and Apc2 gene (P=0.012).The H3K4 demethylase inhibitor T-448 effectively reversed the H3K4me1 binding in the differential peak regions of the aforementioned genes (P=0.01).The results of RNA-seq for the brain tissue of NTD fetal mice showed significant enrichment of the differentially expressed genes in the Wnt signaling pathway (P=1.52×10^-5).The enrichment of differential peak regions of H3K4me1-marked enhancers in Apc2,Ldlrap1,and Camta1 genes in the brain tissue also showed significant changes.The differential peak region in Apc2 exhibited transcription factor activity (P=0.020). Conclusion Folate deficiency may affect changes in H3K4me1-marked enhancers to participate in the regulation of neural tube closure genes,thereby inducing the occurrence of NTD.
Neural Tube Defects/genetics* ; Animals ; Mice ; Folic Acid Deficiency/complications* ; Histones/metabolism* ; Folic Acid/metabolism* ; Methylation ; Mouse Embryonic Stem Cells/metabolism* ; Wnt Signaling Pathway ; Lysine/metabolism* ; Chromatin Immunoprecipitation Sequencing

Objective: To investigate the effect of ubiquitin mutation at position 331 of tumor necrosis factor receptor related factor 6 (TRAF6) on the biological characteristics of colorectal cancer cells and its mechanism. Methods: lentivirus wild type (pCDH-3×FLAG-TRAF6) and mutation (pCDH-3×FLAG-TRAF6-331mut) of TRAF6 gene expression plasmid with green fluorescent protein tag were used to infect colorectal cancer cells SW480 and HCT116, respectively. The infection was observed by fluorescence microscope, and the expressions of TRAF6 and TRAF6-331mut in cells was detected by western blot. Cell counting kit-8 (CCK-8) and plate cloning test were used to detect the proliferation ability of colorectal cancer cells in TRAF6 group and TRAF6-331mut group, cell scratch test to detect cell migration, Transwell chamber test to detect cell migration and invasion, immunoprecipitation to detect the ubiquitination of TRAF6 and TRAF6-331mut with ubiquitinof lysine binding sites K48 and K63. Western blot was used to detect the effects of TRAF6 and TRAF6-331mut over expression on the nuclear factor kappa-B (NF-κB) and mitogen activated protein kinase mitogen-activated protein kinase (MAPK)/activating protein-1(AP-1) signal pathway. Results: The successful infection of colorectal cancer cells was observed under fluorescence microscope. Western blot detection showed that TRAF6 and TRAF6-331mut were successfully expressed in colorectal cancer cells. The results of CCK-8 assay showed that on the fourth day, the absorbance values of HCT116 and SW480 cells in TRAF6-331mut group were 1.89±0.39 and 1.88±0.24 respectively, which were lower than those in TRAF6 group (2.09±0.12 and 2.17±0.45, P=0.036 and P=0.011, respectively). The results of plate colony formation assay showed that the number of clones of HCT116 and SW480 cells in TRAF6-331mut group was 120±14 and 85±14 respectively, which was lower than those in TRAF6 group (190±21 and 125±13, P=0.001 and P=0.002, respectively). The results of cell scratch test showed that after 48 hours, the percentage of wound healing distance of HCT116 and SW480 cells in TRAF6-331mut group was (31±12)% and (33±14)%, respectively, which was lower than those in TRAF6 group [(43±13)% and (43±7)%, P=0.005 and 0.009, respectively]. The results of Transwell migration assay showed that the migration numbers of HCT116 and SW480 cells in TRAF6-331mut group were significantly lower than those in TRAF6 group (P<0.001 and P<0.002, respectively). The results of Transwell invasion assay showed that the number of membrane penetration of HCT116 and SW480 cells in TRAF6-331mut group was significantly lower than those in TRAF6 group (P=0.008 and P=0.009, respectively). The results of immunoprecipitation detection showed that the ubiquitin protein of K48 chain pulled by TRAF6-331mut was lower than that of wild type TRAF6 in 293T cells co-transfected with K48 (0.57±0.19), and the ubiquitin protein of K63 chain pulled down by TRAF6-331mut in 293T cells co-transfected with K63 was lower than that of wild type TRAF6 (0.89±0.08, P<0.001). Western blot assay showed that the protein expression levels of NF-κB, p-NF-κB and p-AP-1 in TRAF6-331mut-HCT116 cells were 0.63±0.08, 0.42±0.08 and 0.60±0.07 respectively, which were lower than those in TRAF6-HCT116 cells (P=0.002, P<0.001 and P<0.001, respectively). The expression level of AP-1 protein in TRAF6-HCT116 cells was 0.89±0.06, compared with that in TRAF6-HCT116 cells. The difference was not statistically significant (P>0.05). The protein expression levels of NF-κB, p-NF-κB and p-AP-1 in TRAF6-331mut-SW480 cells were 0.50±0.06, 0.51±0.04, 0.48±0.02, respectively, which were lower than those in TRAF6-SW480 cells (all P<0.001). There was no significant difference in AP-1 protein expression between TRAF6-331mut-SW480 cells and TRAF6-SW480 cells. Conclusion: The ubiquitin site mutation of TRAF6 gene at 331 may prevent the binding of TRAF6 and ubiquitin lysine sites K48 and K63, and then affect the expressions of proteins related to downstream NF-κB and MAPK/AP-1 signal pathways, and inhibit the proliferation, migration and invasion of colorectal cancer cells.
Humans ; Cell Line, Tumor ; Cell Movement ; Cell Proliferation ; Colorectal Neoplasms/pathology* ; Lysine/metabolism* ; NF-kappa B/metabolism* ; TNF Receptor-Associated Factor 6/metabolism* ; Transcription Factor AP-1/metabolism* ; Ubiquitin/metabolism*