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1.
Nat Commun ; 15(1): 4883, 2024 Jun 07.
Article in English | MEDLINE | ID: mdl-38849395

ABSTRACT

The human methyltransferase and transcriptional coactivator MLL4 and its paralog MLL3 are frequently mutated in cancer. MLL4 and MLL3 monomethylate histone H3K4 and contain a set of uncharacterized PHD fingers. Here, we report a novel function of the PHD2 and PHD3 (PHD2/3) fingers of MLL4 and MLL3 that bind to ASXL2, a component of the Polycomb repressive H2AK119 deubiquitinase (PR-DUB) complex. The structure of MLL4 PHD2/3 in complex with the MLL-binding helix (MBH) of ASXL2 and mutational analyses reveal the molecular mechanism which is conserved in homologous ASXL1 and ASXL3. The native interaction of the Trithorax MLL3/4 complexes with the PR-DUB complex in vivo depends solely on MBH of ASXL1/2, coupling the two histone modifying activities. ChIP-seq analysis in embryonic stem cells demonstrates that MBH of ASXL1/2 is required for the deubiquitinase BAP1 recruitment to MLL4-bound active enhancers. Our findings suggest an ASXL1/2-dependent functional link between the MLL3/4 and PR-DUB complexes.


Subject(s)
DNA-Binding Proteins , Histone-Lysine N-Methyltransferase , Protein Binding , Repressor Proteins , Tumor Suppressor Proteins , Ubiquitin Thiolesterase , Tumor Suppressor Proteins/metabolism , Tumor Suppressor Proteins/genetics , Humans , Histone-Lysine N-Methyltransferase/metabolism , Histone-Lysine N-Methyltransferase/genetics , Ubiquitin Thiolesterase/metabolism , Ubiquitin Thiolesterase/genetics , Repressor Proteins/metabolism , Repressor Proteins/genetics , Animals , DNA-Binding Proteins/metabolism , DNA-Binding Proteins/genetics , Mice , Enhancer Elements, Genetic , HEK293 Cells , PHD Zinc Fingers , Histones/metabolism
2.
Plant Mol Biol ; 114(3): 67, 2024 Jun 05.
Article in English | MEDLINE | ID: mdl-38836995

ABSTRACT

Sugar beet (Beta vulgaris L.), a biennial sugar crop, contributes about 16% of the world's sugar production. The transition from vegetative growth, during which sugar accumulated in beet, to reproductive growth, during which sugar exhausted in beet, is determined by vernalization and photoperiod. GIGANTEA (GI) is a key photoperiodic flowering gene that is induced by vernalization in sugar beet. To identify the upstream regulatory factors of BvGI, candidate transcription factors (TF) that were co-expressed with BvGI and could bind to the BvGI promoter were screened based on weighted gene co-expression network analysis (WGCNA) and TF binding site prediction. Subsequently, their transcriptional regulatory role on the BvGI was validated through subcellular localization, dual-luciferase assays and yeast transformation tests. A total of 7,586 differentially expressed genes were identified after vernalization and divided into 18 co-expression modules by WGCNA, of which one (MEcyan) and two (MEdarkorange2 and MEmidnightblue) modules were positively and negatively correlated with the expression of BvGI, respectively. TF binding site predictions using PlantTFDB enabled the screening of BvLHY, BvTCP4 and BvCRF4 as candidate TFs that negatively regulated the expression of BvGI by affecting its transcription. Subcellular localization showed that BvLHY, BvTCP4 and BvCRF4 were localized to the nucleus. The results of dual-luciferase assays and yeast transformation tests showed that the relative luciferase activity and expression of HIS3 was reduced in the BvLHY, BvTCP4 and BvCRF4 transformants, which suggested that the three TFs inhibited the BvGI promoter. In addition, real-time quantitative reverse transcription PCR showed that BvLHY and BvTCP4 exhibited rhythmic expression characteristics similar to that of BvGI, while BvCRF4 did not. Our results revealed that vernalization crosstalked with the photoperiod pathway to initiate bolting in sugar beet by inhibiting the transcriptional repressors of BvGI.


Subject(s)
Beta vulgaris , Flowers , Gene Expression Regulation, Plant , Plant Proteins , Transcription Factors , Beta vulgaris/genetics , Beta vulgaris/growth & development , Beta vulgaris/physiology , Plant Proteins/genetics , Plant Proteins/metabolism , Transcription Factors/metabolism , Transcription Factors/genetics , Flowers/genetics , Flowers/growth & development , Flowers/physiology , Promoter Regions, Genetic/genetics , Repressor Proteins/genetics , Repressor Proteins/metabolism , Photoperiod , Vernalization
3.
Biochemistry (Mosc) ; 89(4): 626-636, 2024 Apr.
Article in English | MEDLINE | ID: mdl-38831500

ABSTRACT

Su(Hw) belongs to the class of proteins that organize chromosome architecture, determine promoter activity, and participate in formation of the boundaries/insulators between the regulatory domains. This protein contains a cluster of 12 zinc fingers of the C2H2 type, some of which are responsible for binding to the consensus site. The Su(Hw) protein forms complex with the Mod(mdg4)-67.2 and the CP190 proteins, where the last one binds to all known Drosophila insulators. To further study functioning of the Su(Hw)-dependent complexes, we used the previously described su(Hw)E8 mutation with inactive seventh zinc finger, which produces mutant protein that cannot bind to the consensus site. The present work shows that the Su(Hw)E8 protein continues to directly interact with the CP190 and Mod(mdg4)-67.2 proteins. Through interaction with Mod(mdg4)-67.2, the Su(Hw)E8 protein can be recruited into the Su(Hw)-dependent complexes formed on chromatin and enhance their insulator activity. Our results demonstrate that the Su(Hw) dependent complexes without bound DNA can be recruited to the Su(Hw) binding sites through the specific protein-protein interactions that are stabilized by Mod(mdg4)-67.2.


Subject(s)
Chromatin , Drosophila Proteins , Drosophila melanogaster , Repressor Proteins , Transcription Factors , Drosophila Proteins/metabolism , Drosophila Proteins/genetics , Drosophila Proteins/chemistry , Animals , Chromatin/metabolism , Transcription Factors/metabolism , Drosophila melanogaster/metabolism , Repressor Proteins/metabolism , Repressor Proteins/genetics , Protein Binding , Nuclear Proteins/metabolism , DNA-Binding Proteins/metabolism , Zinc Fingers , Microtubule-Associated Proteins
4.
Elife ; 122024 Jun 05.
Article in English | MEDLINE | ID: mdl-38836839

ABSTRACT

New experimental findings continue to challenge our understanding of protein allostery. Recent deep mutational scanning study showed that allosteric hotspots in the tetracycline repressor (TetR) and its homologous transcriptional factors are broadly distributed rather than spanning well-defined structural pathways as often assumed. Moreover, hotspot mutation-induced allostery loss was rescued by distributed additional mutations in a degenerate fashion. Here, we develop a two-domain thermodynamic model for TetR, which readily rationalizes these intriguing observations. The model accurately captures the in vivo activities of various mutants with changes in physically transparent parameters, allowing the data-based quantification of mutational effects using statistical inference. Our analysis reveals the intrinsic connection of intra- and inter-domain properties for allosteric regulation and illustrate epistatic interactions that are consistent with structural features of the protein. The insights gained from this study into the nature of two-domain allostery are expected to have broader implications for other multi-domain allosteric proteins.


Subject(s)
Mutation , Repressor Proteins , Thermodynamics , Allosteric Regulation , Repressor Proteins/chemistry , Repressor Proteins/metabolism , Repressor Proteins/genetics , Protein Domains , Models, Molecular
5.
Nat Commun ; 15(1): 4790, 2024 Jun 05.
Article in English | MEDLINE | ID: mdl-38839752

ABSTRACT

Cancer cells are often addicted to serine synthesis to support growth. How serine synthesis is regulated in cancer is not well understood. We recently demonstrated protein arginine methyltransferase 1 (PRMT1) is upregulated in hepatocellular carcinoma (HCC) to methylate and activate phosphoglycerate dehydrogenase (PHGDH), thereby promoting serine synthesis. However, the mechanisms underlying PRMT1 upregulation and regulation of PRMT1-PHGDH axis remain unclear. Here, we show the E3 ubiquitin ligase F-box-only protein 7 (FBXO7) inhibits serine synthesis in HCC by binding PRMT1, inducing lysine 37 ubiquitination, and promoting proteosomal degradation of PRMT1. FBXO7-mediated PRMT1 downregulation cripples PHGDH arginine methylation and activation, resulting in impaired serine synthesis, accumulation of reactive oxygen species (ROS), and inhibition of HCC cell growth. Notably, FBXO7 is significantly downregulated in human HCC tissues, and inversely associated with PRMT1 protein and PHGDH methylation level. Overall, our study provides mechanistic insights into the regulation of cancer serine synthesis by FBXO7-PRMT1-PHGDH axis, and will facilitate the development of serine-targeting strategies for cancer therapy.


Subject(s)
Carcinoma, Hepatocellular , F-Box Proteins , Liver Neoplasms , Phosphoglycerate Dehydrogenase , Protein-Arginine N-Methyltransferases , Serine , Ubiquitination , Protein-Arginine N-Methyltransferases/metabolism , Protein-Arginine N-Methyltransferases/genetics , Humans , Carcinoma, Hepatocellular/metabolism , Carcinoma, Hepatocellular/pathology , Carcinoma, Hepatocellular/genetics , Liver Neoplasms/metabolism , Liver Neoplasms/pathology , Liver Neoplasms/genetics , F-Box Proteins/metabolism , F-Box Proteins/genetics , Serine/metabolism , Serine/biosynthesis , Phosphoglycerate Dehydrogenase/metabolism , Phosphoglycerate Dehydrogenase/genetics , Cell Line, Tumor , Animals , Repressor Proteins/metabolism , Repressor Proteins/genetics , Mice , Cell Proliferation , Methylation , Gene Expression Regulation, Neoplastic , Mice, Nude , Male , HEK293 Cells , Female , Hep G2 Cells
6.
PLoS One ; 19(6): e0304770, 2024.
Article in English | MEDLINE | ID: mdl-38829888

ABSTRACT

Age-related hearing loss is a complex disease caused by a combination of genetic and environmental factors, and a study have conducted animal experiments to explore the association between BCL11B heterozygosity and age-related hearing loss. The present study used established genetic models to examine the association between BCL11B gene polymorphisms and age-related hearing loss. A total of 410 older adults from two communities in Qingdao, China, participated in this study. The case group comprised individuals aged ≥ 60 years with age-related hearing loss, and the control group comprised individuals without age-related hearing loss from the same communities. The groups were matched 1:1 for age and sex. The individual characteristics of the participants were analyzed descriptively using the Mann-Whitney U test and the chi-square test. To explore the association between BCL11B gene polymorphisms and age-related hearing loss, conditional logistic regression was performed to construct genetic models for two single-nucleotide-polymorphisms (SNPs) of BCL11B, and haplotype analysis was conducted to construct their haplotype domains. Two SNP sites of the BCL11B gene, four genetic models of rs1152781 (additive, dominant, recessive, and codominant), and five genetic models of rs1152783 (additive, dominant, recessive, codominant, and over dominant) were significantly associated with age-related hearing loss in the models both unadjusted and adjusted for all covariates (P < 0.05). Additionally, a linkage disequilibrium between rs1152781 and rs1152783 was revealed through haplotype analysis. Our study revealed that BCL11B gene polymorphisms were significantly associated with age-related hearing loss.


Subject(s)
Haplotypes , Polymorphism, Single Nucleotide , Repressor Proteins , Tumor Suppressor Proteins , Humans , Male , Female , Aged , China/epidemiology , Case-Control Studies , Middle Aged , Repressor Proteins/genetics , Tumor Suppressor Proteins/genetics , Hearing Loss/genetics , Hearing Loss/epidemiology , Genetic Predisposition to Disease , Aged, 80 and over , Presbycusis/genetics , Presbycusis/epidemiology , Linkage Disequilibrium
8.
Cell Mol Life Sci ; 81(1): 254, 2024 Jun 10.
Article in English | MEDLINE | ID: mdl-38856931

ABSTRACT

The endogenous mitochondrial quality control (MQC) system serves to protect mitochondria against cellular stressors. Although mitochondrial dysfunction contributes to cardiac damage during many pathological conditions, the regulatory signals influencing MQC disruption during septic cardiomyopathy (SC) remain unclear. This study aimed to investigate the involvement of pyruvate kinase M2 (PKM2) and prohibitin 2 (PHB2) interaction followed by MQC impairment in the pathogenesis of SC. We utilized LPS-induced SC models in PKM2 transgenic (PKM2TG) mice, PHB2S91D-knockin mice, and PKM2-overexpressing HL-1 cardiomyocytes. After LPS-induced SC, cardiac PKM2 expression was significantly downregulated in wild-type mice, whereas PKM2 overexpression in vivo sustained heart function, suppressed myocardial inflammation, and attenuated cardiomyocyte death. PKM2 overexpression relieved sepsis-related mitochondrial damage via MQC normalization, evidenced by balanced mitochondrial fission/fusion, activated mitophagy, restored mitochondrial biogenesis, and inhibited mitochondrial unfolded protein response. Docking simulations, co-IP, and domain deletion mutant protein transfection experiments showed that PKM2 phosphorylates PHB2 at Ser91, preventing LPS-mediated PHB2 degradation. Additionally, the A domain of PKM2 and the PHB domain of PHB2 are required for PKM2-PHB2 binding and PHB2 phosphorylation. After LPS exposure, expression of a phosphorylation-defective PHB2S91A mutant negated the protective effects of PKM2 overexpression. Moreover, knockin mice expressing a phosphorylation-mimetic PHB2S91D mutant showed improved heart function, reduced inflammation, and preserved mitochondrial function following sepsis induction. Abundant PKM2 expression is a prerequisite to sustain PKM2-PHB2 interaction which is a key element for preservation of PHB2 phosphorylation and MQC, presenting novel interventive targets for the treatment of septic cardiomyopathy.


Subject(s)
Cardiomyopathies , Myocytes, Cardiac , Prohibitins , Pyruvate Kinase , Repressor Proteins , Sepsis , Animals , Phosphorylation , Cardiomyopathies/metabolism , Cardiomyopathies/pathology , Mice , Pyruvate Kinase/metabolism , Pyruvate Kinase/genetics , Sepsis/metabolism , Repressor Proteins/metabolism , Repressor Proteins/genetics , Myocytes, Cardiac/metabolism , Myocytes, Cardiac/pathology , Mitochondria, Heart/metabolism , Mice, Transgenic , Mice, Inbred C57BL , Male , Lipopolysaccharides , Humans , Mitophagy
9.
Diagn Pathol ; 19(1): 76, 2024 Jun 08.
Article in English | MEDLINE | ID: mdl-38851744

ABSTRACT

BACKGROUND: CIC-rearranged sarcomas (CRS) represent a new entity of undifferentiated small round cell sarcoma belonging to the Ewing-like sarcomas family. CRS are the most common type. Fusion partners for the CIC gene include DUX4, FOXO4, and the recently recognizedNUTM1. Rare cases of CIC::NUTM1 sarcoma in pediatric patients have recently been reported in brain, kidney, bone, and soft tissues. However, such cases have not been identified in the soft tissues of the limbs. CASE PRESENTATION: We reported a case of CIC::NUTM1 sarcoma located in the right upper limb of an 18-year-old man. The tumor displayed morphologic features typical of CIC::DUX4 sarcomas, with small- to medium-sized round cells, a lobular pattern, focal spindling, myxoid stroma, and patchy necrosis. The tumor diffusely expressed NUTM1, was positive for WT1cter at weak to moderate intensity, and was focally positive for CD99, while it was negative for keratins, EMA, P40, MyoD1, myogenin, NKX2.2, BCOR, and pan-TRK. Fluorescence in situ hybridization analyses revealed cleavage of the CIC and NUTM1 genes. CONCLUSION: CIC::NUTM1 sarcomas represent a novel molecular variant of CRS with a preference for the central nervous system and younger pediatric persons. Its morphology and phenotype may be mistaken for NUT carcinomas, and the behavior is more progressive than other forms of CRS. For this rare and newly discovered gene fusion variant, it is necessary to integrate molecular and immunohistochemical findings with morphologic features in the diagnosis of undifferentiated neoplasms.


Subject(s)
Repressor Proteins , Soft Tissue Neoplasms , Humans , Male , Adolescent , Soft Tissue Neoplasms/genetics , Soft Tissue Neoplasms/pathology , Repressor Proteins/genetics , Neoplasm Proteins/genetics , Nuclear Proteins/genetics , Biomarkers, Tumor/genetics , Biomarkers, Tumor/analysis , Oncogene Proteins, Fusion/genetics , Sarcoma/genetics , Sarcoma/pathology , Sarcoma/diagnosis , Upper Extremity/pathology , Gene Rearrangement , Homeobox Protein Nkx-2.2 , In Situ Hybridization, Fluorescence , Transcription Factors , Homeodomain Proteins
10.
Commun Biol ; 7(1): 707, 2024 Jun 08.
Article in English | MEDLINE | ID: mdl-38851815

ABSTRACT

The human protein lysine methyltransferase NSD2 catalyzes dimethylation at H3K36. It has very important roles in development and disease but many mechanistic features and its full spectrum of substrate proteins are unclear. Using peptide SPOT array methylation assays, we investigate the substrate sequence specificity of NSD2 and discover strong readout of residues between G33 (-3) and P38 (+2) on H3K36. Unexpectedly, we observe that amino acid residues different from natural ones in H3K36 are preferred at some positions. Combining four preferred residues led to the development of a super-substrate which is methylated much faster by NSD2 at peptide and protein level. Molecular dynamics simulations demonstrate that this activity increase is caused by distinct hyperactive conformations of the enzyme-peptide complex. To investigate the substrate spectrum of NSD2, we conducted a proteome wide search for nuclear proteins matching the specificity profile and discovered 22 peptide substrates of NSD2. In protein methylation studies, we identify K1033 of ATRX and K819 of FANCM as NSD2 methylation sites and also demonstrate their methylation in human cells. Both these proteins have important roles in DNA repair strengthening the connection of NSD2 and H3K36 methylation to DNA repair.


Subject(s)
Histone-Lysine N-Methyltransferase , Humans , Histone-Lysine N-Methyltransferase/metabolism , Histone-Lysine N-Methyltransferase/chemistry , Histone-Lysine N-Methyltransferase/genetics , Substrate Specificity , Methylation , Molecular Dynamics Simulation , Repressor Proteins/metabolism , Repressor Proteins/genetics , Repressor Proteins/chemistry , Histones/metabolism , Histones/chemistry , Histones/genetics , Peptides/metabolism , Peptides/chemistry
11.
J Cancer Res Clin Oncol ; 150(6): 294, 2024 Jun 06.
Article in English | MEDLINE | ID: mdl-38842683

ABSTRACT

BACKGROUND: Cervical cancer (CC) is a common malignancy amongst women globally. Ubiquitination plays a dual role in the occurrence and development of cancers. This study analyzed the mechanism of long noncoding RNA HOXC cluster antisense RNA 3 (lncRNA HOXC-AS3) in malignant proliferation of CC cells via mediating ubiquitination of lysine demethylase 5B (KDM5B/JARID1B). METHODS: The expression patterns of lncRNA HOXC-AS3 and KDM5B were measured by real-time quantitative polymerase chain reaction or Western blot analysis. After transfection with lncRNA HOXC-AS3 siRNA and pcDNA3.1-KDM5B, proliferation of CC cells was assessed by the cell counting kit-8, colony formation, and 5-Ethynyl-2'-deoxyuridine staining assays. The xenograft tumor model was established to confirm the impact of lncRNA HOXC-AS3 on CC cell proliferation in vivo by measuring tumor size and weight and the immunohistochemistry assay. The subcellular location of lncRNA HOXC-AS3 and the binding of lncRNA HOXC-AS3 to KDM5B were analyzed. After treatment of lncRNA HOXC-AS3 siRNA or MG132, the protein and ubiquitination levels of KDM5B were determined. Thereafter, the interaction and the subcellular co-location of tripartite motif-containing 37 (TRIM37) and KDM5B were analyzed by the co-immunoprecipitation and immunofluorescence assays. RESULTS: LncRNA HOXC-AS3 and KDM5B were upregulated in CC tissues and cells. Depletion of lncRNA HOXC-AS3 repressed CC cell proliferation and in vivo tumor growth. Mechanically, lncRNA HOXC-AS3 located in the nucleus directly bound to KDM5B, inhibited TRIM37-mediated ubiquitination of KDM5B, and upregulated the protein levels of KDM5B. KDM5B overexpression attenuated the inhibitory role of silencing lncRNA HOXC-AS3 in CC cell proliferation in vivo and in vitro. CONCLUSION: Nucleus-located lncRNA HOXC-AS3 facilitated malignant proliferation of CC cells via stabilization of KDM5B protein levels.


Subject(s)
Cell Proliferation , Jumonji Domain-Containing Histone Demethylases , Mice, Nude , RNA, Long Noncoding , Uterine Cervical Neoplasms , Humans , Uterine Cervical Neoplasms/genetics , Uterine Cervical Neoplasms/pathology , Uterine Cervical Neoplasms/metabolism , RNA, Long Noncoding/genetics , Female , Cell Proliferation/genetics , Jumonji Domain-Containing Histone Demethylases/genetics , Jumonji Domain-Containing Histone Demethylases/metabolism , Animals , Mice , Ubiquitination , Cell Line, Tumor , Repressor Proteins/genetics , Repressor Proteins/metabolism , Gene Expression Regulation, Neoplastic , Mice, Inbred BALB C , Xenograft Model Antitumor Assays , Nuclear Proteins
12.
Int J Biol Sci ; 20(7): 2622-2639, 2024.
Article in English | MEDLINE | ID: mdl-38725840

ABSTRACT

Sorafenib is a standard first-line drug for advanced hepatocellular carcinoma, but the serious cardiotoxic effects restrict its therapeutic applicability. Here, we show that iron-dependent ferroptosis plays a vital role in sorafenib-induced cardiotoxicity. Remarkably, our in vivo and in vitro experiments demonstrated that ferroptosis inhibitor application neutralized sorafenib-induced heart injury. By analyzing transcriptome profiles of adult human sorafenib-treated cardiomyocytes, we found that Krüppel-like transcription factor 11 (KLF11) expression significantly increased after sorafenib stimulation. Mechanistically, KLF11 promoted ferroptosis by suppressing transcription of ferroptosis suppressor protein 1 (FSP1), a seminal breakthrough due to its ferroptosis-repressing properties. Moreover, FSP1 knockdown showed equivalent results to glutathione peroxidase 4 (GPX4) knockdown, and FSP1 overexpression counteracted GPX4 inhibition-induced ferroptosis to a substantial extent. Cardiac-specific overexpression of FSP1 and silencing KLF11 by an adeno-associated virus serotype 9 markedly improved cardiac dysfunction in sorafenib-treated mice. In summary, FSP1-mediated ferroptosis is a crucial mechanism for sorafenib-provoked cardiotoxicity, and targeting ferroptosis may be a promising therapeutic strategy for alleviating sorafenib-induced cardiac damage.


Subject(s)
Cardiotoxicity , Ferroptosis , S100 Calcium-Binding Protein A4 , Sorafenib , Sorafenib/adverse effects , Ferroptosis/drug effects , Animals , Mice , Cardiotoxicity/metabolism , Cardiotoxicity/etiology , Humans , S100 Calcium-Binding Protein A4/metabolism , S100 Calcium-Binding Protein A4/genetics , Male , Mice, Inbred C57BL , Myocytes, Cardiac/metabolism , Myocytes, Cardiac/drug effects , Repressor Proteins/metabolism , Repressor Proteins/genetics
13.
Int J Biol Sci ; 20(7): 2422-2439, 2024.
Article in English | MEDLINE | ID: mdl-38725842

ABSTRACT

Background & Aims: Reactive oxygen species (ROS) act as modulators triggering cellular dysfunctions and organ damage including liver fibrosis in which hepatic stellate cell (HSC) activation plays a key role. Previous studies suggest that microRNA-144 (miR-144) acts as a pro-oxidant molecule; however, whether and how miR-144 affects HSC activation and liver fibrosis remain unknown. Methods: Carbon tetrachloride (CCl4) and bile duct ligation (BDL)-induced experimental liver fibrosis models were used. Hepatic miR-144 expression was analyzed by miRNA in situ hybridization with RNAscope probe. The in vivo effects of silencing or overexpressing miR-144 were examined with an adeno-associated virus 6 (AAV6) carrying miR-144 inhibitor or mimics in fibrotic mouse experimental models. Results: In this study, we demonstrated that ROS treatment significantly upregulated miR-144 in HSCs, which further promoted HSC activation in vitro. Interestingly, miR-144 was preferentially elevated in HSCs of experimental liver fibrosis in mice and in human liver fibrotic tissues. Furthermore, in vivo loss or gain-of-function experiments via AAV6 carrying miR-144 antagomir or agomir revealed that blockade of miR-144 in HSCs mitigated, while overexpression of miR-144 in HSCs accelerated the development of experimental liver fibrosis. Mechanistically, SIN3 transcription regulator family member A (SIN3A), a transcriptional repressor, was identified to be the target of miR-144 in HSCs. MiR-144 downregulated Sin3A, and in line with this result, specific knockdown of Sin3a in HSCs remarkedly activated p38 MAPK signaling pathway to promote HSC activation, eventually exacerbating liver fibrosis. Conclusions: Oxidative stress-driven miR-144 fuels HSC activation and liver fibrogenesis by limiting the SIN3A-p38 axis. Thus, a specific inhibition of miR-144 in HSCs could be a novel therapeutic strategy for the treatment of liver fibrosis.


Subject(s)
Hepatic Stellate Cells , Liver Cirrhosis , MicroRNAs , Oxidative Stress , Reactive Oxygen Species , Sin3 Histone Deacetylase and Corepressor Complex , p38 Mitogen-Activated Protein Kinases , MicroRNAs/metabolism , MicroRNAs/genetics , Animals , Hepatic Stellate Cells/metabolism , Liver Cirrhosis/metabolism , Liver Cirrhosis/genetics , Liver Cirrhosis/pathology , Mice , Humans , p38 Mitogen-Activated Protein Kinases/metabolism , Sin3 Histone Deacetylase and Corepressor Complex/metabolism , Reactive Oxygen Species/metabolism , Male , Mice, Inbred C57BL , Repressor Proteins/metabolism , Repressor Proteins/genetics , Carbon Tetrachloride
14.
J Cell Biol ; 223(8)2024 Aug 05.
Article in English | MEDLINE | ID: mdl-38709169

ABSTRACT

Histone H3 lysine36 dimethylation (H3K36me2) is generally distributed in the gene body and euchromatic intergenic regions. However, we found that H3K36me2 is enriched in pericentromeric heterochromatin in some mouse cell lines. We here revealed the mechanism of heterochromatin targeting of H3K36me2. Among several H3K36 methyltransferases, NSD2 was responsible for inducing heterochromatic H3K36me2. Depletion and overexpression analyses of NSD2-associating proteins revealed that NSD2 recruitment to heterochromatin was mediated through the imitation switch (ISWI) chromatin remodeling complexes, such as BAZ1B-SMARCA5 (WICH), which directly binds to AT-rich DNA via a BAZ1B domain-containing AT-hook-like motifs. The abundance and stoichiometry of NSD2, SMARCA5, and BAZ1B could determine the localization of H3K36me2 in different cell types. In mouse embryos, H3K36me2 heterochromatin localization was observed at the two- to four-cell stages, suggesting its physiological relevance.


Subject(s)
Chromatin Assembly and Disassembly , Heterochromatin , Histone-Lysine N-Methyltransferase , Histones , Repressor Proteins , Animals , Humans , Mice , Adenosine Triphosphatases , Bromodomain Containing Proteins/genetics , Bromodomain Containing Proteins/metabolism , Centromere/metabolism , Centromere/genetics , Chromosomal Proteins, Non-Histone/metabolism , Chromosomal Proteins, Non-Histone/genetics , Heterochromatin/metabolism , Heterochromatin/genetics , Histone-Lysine N-Methyltransferase/metabolism , Histone-Lysine N-Methyltransferase/genetics , Histones/metabolism , Histones/genetics , Methylation , Repressor Proteins/metabolism , Repressor Proteins/genetics , Transcription Factors/metabolism , Transcription Factors/genetics
15.
BMC Genomics ; 25(1): 441, 2024 May 03.
Article in English | MEDLINE | ID: mdl-38702600

ABSTRACT

BACKGROUND: Quorum sensing (QS) is a sophisticated cell-to-cell signalling mechanism that allows the coordination of important processes in microbial populations. The AI-1 and AI-2 autoinducer systems are among the best characterized bacterial QS systems at the genetic level. RESULTS: In this study, we present data derived from in silico screening of QS proteins from bacterial genomes available in public databases. Sequence analyses allowed identifying candidate sequences of known QS systems that were used to build phylogenetic trees. Eight categories were established according to the number of genes from the two major QS systems present in each genome, revealing a correlation with specific taxa, lifestyles or metabolic traits. Many species had incomplete QS systems, encoding the receptor protein but not the biosynthesis of the quorum sensing molecule (QSMs). Reconstruction of the evolutionary history of the LuxR family and prediction of the 3D structure of the ancestral protein suggested their monomeric configuration in the absence of the signal molecule and the presence of a cavity for its binding. CONCLUSIONS: Here we correlate the taxonomic affiliation and lifestyle of bacteria from different genera with the QS systems encoded in their genomes. Moreover, we present the first ancestral reconstruction of the LuxR QS receptors, providing further insight in their evolutionary history.


Subject(s)
Bacteria , Bacterial Proteins , Evolution, Molecular , Phylogeny , Quorum Sensing , Quorum Sensing/genetics , Bacterial Proteins/genetics , Bacterial Proteins/metabolism , Bacteria/genetics , Bacteria/metabolism , Genome, Bacterial , Trans-Activators/genetics , Trans-Activators/metabolism , Trans-Activators/chemistry , Repressor Proteins/genetics , Repressor Proteins/metabolism
16.
J Genet ; 1032024.
Article in English | MEDLINE | ID: mdl-38736250

ABSTRACT

In acute lymphoblastic leukaemia (ALL), elevated foetal haemoglobin (HbF) levels have been associated with the prognosis of patients. Genetic variants in HbF regulatory genes: BAF chromatin remodelling complex subunit (BCL11A), HBS1L-MYB transcriptional GTPase intergenic region (HBS1L-MYB), Krüppel-like factor 1 (KLF1), haemoglobin gamma subunit 2 (HBG2), haemoglobin gamma subunit 1 (HBG1), and haemoglobin subunit beta pseudogene 1 (HBBP1) are often associatedwith elevatedHbF concentration. This study investigated the association of genetic variants in HbF regulatory genes with HbF concentration, unfavourable prognosis, and outcome in children with ALL.We quantified HbF concentration and genotyped 17 genetic variants in 48 patients with ALL and 64 children without ALL as a reference group. HbF concentrationwas higher in patients than in the reference group (4.4%vs 1.4%), and 75%(n = 36) of thepatientshadHbF>2.5%.Unfavourable prognosis ALL was established in 68.8% (n = 33) of the patients. Variant HBG2 rs7482144 was associated with high HbF concentration (P = 0.015); while HBS1L-MYB rs9399137 (P = 0.001), HBG2 rs7482144 (P = 0.001) and the ß-globin genes HBG2, HBG1, and HBPP1 haplotypeTGC(P = 0.017) with unfavourable prognosisALL.Additionally, variantBCL11A rs4671393 showed a protective role (P = 0.0001). In conclusion, variants HBG2 rs7482144, HBS1L-MYB rs9399137 and BCL11A rs4671393 may play a significant role in ALL.


Subject(s)
Fetal Hemoglobin , Polymorphism, Single Nucleotide , Precursor Cell Lymphoblastic Leukemia-Lymphoma , Repressor Proteins , Humans , Fetal Hemoglobin/genetics , Female , Male , Child , Prognosis , Repressor Proteins/genetics , Child, Preschool , Precursor Cell Lymphoblastic Leukemia-Lymphoma/genetics , Infant , Nuclear Proteins/genetics , Proto-Oncogene Proteins c-myb/genetics , Carrier Proteins/genetics , Adolescent , Genotype , gamma-Globins/genetics , GTP-Binding Proteins
17.
BMC Pediatr ; 24(1): 308, 2024 May 06.
Article in English | MEDLINE | ID: mdl-38711055

ABSTRACT

BACKGROUND: ASXL3-related disorder, first described in 2013, is a genetic disorder with an autosomal dominant inheritance that is caused by a heterozygous loss-of-function variant in ASXL3. The most characteristic feature is neurodevelopmental delay with consistently limited speech. Feeding difficulty is a main symptom observed in infancy. However, no adolescent case has been reported. CASE PRESENTATION: A 14-year-old girl with ASXL3-related syndrome was referred to our hospital with subacute onset of emotional lability. Limbic encephalitis was ruled out by examination; however, the patient gradually showed a lack of interest in eating, with decreased diet volume. Consequently, she experienced significant weight loss. She experienced no symptoms of bulimia, or food allergy; therefore, avoidant/restrictive food intake disorder (ARFID) was clinically suspected. CONCLUSIONS: We reported the first case of ASXL3-related disorder with adolescent onset of feeding difficulty. ARFID was considered a cause of the feeding difficulty.


Subject(s)
Abnormalities, Multiple , Facies , Feeding and Eating Disorders , Neurodevelopmental Disorders , Humans , Female , Adolescent , Feeding and Eating Disorders/etiology , Feeding and Eating Disorders/complications , Feeding and Eating Disorders/diagnosis , Repressor Proteins/genetics
18.
Cells ; 13(9)2024 Apr 23.
Article in English | MEDLINE | ID: mdl-38727269

ABSTRACT

The histone deacetylase inhibitor (HDACi) valproic acid (VPA) has neuroprotective and anti-inflammatory effects in experimental traumatic brain injury (TBI), which have been partially attributed to the epigenetic disinhibition of the transcription repressor RE1-Silencing Transcription Factor/Neuron-Restrictive Silencer Factor (REST/NRSF). Additionally, VPA changes post-traumatic brain injury (TBI) brain metabolism to create a neuroprotective environment. To address the interconnection of neuroprotection, metabolism, inflammation and REST/NRSF after TBI, we subjected C57BL/6N mice to experimental TBI and intraperitoneal VPA administration or vehicle solution at 15 min, 1, 2, and 3 days post-injury (dpi). At 7 dpi, TBI-induced an up-regulation of REST/NRSF gene expression and HDACi function of VPA on histone H3 acetylation were confirmed. Neurological deficits, brain lesion size, blood-brain barrier permeability, or astrogliosis were not affected, and REST/NRSF target genes were only marginally influenced by VPA. However, VPA attenuated structural damage in the hippocampus, microgliosis and expression of the pro-inflammatory marker genes. Analyses of plasma lipidomic and polar metabolomic patterns revealed that VPA treatment increased lysophosphatidylcholines (LPCs), which were inversely associated with interleukin 1 beta (Il1b) and tumor necrosis factor (Tnf) gene expression in the brain. The results show that VPA has mild neuroprotective and anti-inflammatory effects likely originating from favorable systemic metabolic changes resulting in increased plasma LPCs that are known to be actively taken up by the brain and function as carriers for neuroprotective polyunsaturated fatty acids.


Subject(s)
Brain Injuries, Traumatic , Inflammation , Lysophosphatidylcholines , Mice, Inbred C57BL , Neurons , Valproic Acid , Animals , Brain Injuries, Traumatic/drug therapy , Brain Injuries, Traumatic/pathology , Brain Injuries, Traumatic/blood , Brain Injuries, Traumatic/complications , Valproic Acid/pharmacology , Valproic Acid/therapeutic use , Mice , Male , Neurons/drug effects , Neurons/pathology , Neurons/metabolism , Inflammation/pathology , Inflammation/drug therapy , Lysophosphatidylcholines/blood , Cell Death/drug effects , Disease Models, Animal , Histone Deacetylase Inhibitors/pharmacology , Histone Deacetylase Inhibitors/therapeutic use , Neuroprotective Agents/pharmacology , Neuroprotective Agents/therapeutic use , Repressor Proteins/metabolism , Repressor Proteins/genetics
19.
Sci Adv ; 10(18): eadm7039, 2024 May 03.
Article in English | MEDLINE | ID: mdl-38701209

ABSTRACT

Long-range glutamatergic inputs originating from the cortex and thalamus are indispensable for striatal development, providing the foundation for motor and cognitive functions. Despite their significance, transcriptional regulation governing these inputs remains largely unknown. We investigated the role of a transcription factor encoded by a high-risk autism-associated gene, FOXP1, in sculpting glutamatergic inputs onto spiny projection neurons (SPNs) within the striatum. We find a neuron subtype-specific role of FOXP1 in strengthening and maturing glutamatergic inputs onto dopamine receptor 2-expressing SPNs (D2 SPNs). We also find that FOXP1 promotes synaptically driven excitability in these neurons. Using single-nuclei RNA sequencing, we identify candidate genes that mediate these cell-autonomous processes through postnatal FOXP1 function at the post-synapse. Last, we demonstrate that postnatal FOXP1 reinstatement rescues electrophysiological deficits, cell type-specific gene expression changes, and behavioral phenotypes. Together, this study enhances our understanding of striatal circuit development and provides proof of concept for a therapeutic approach for FOXP1 syndrome and other neurodevelopmental disorders.


Subject(s)
Corpus Striatum , Forkhead Transcription Factors , Neurons , Receptors, Dopamine D2 , Repressor Proteins , Animals , Forkhead Transcription Factors/metabolism , Forkhead Transcription Factors/genetics , Corpus Striatum/metabolism , Corpus Striatum/cytology , Mice , Neurons/metabolism , Repressor Proteins/metabolism , Repressor Proteins/genetics , Phenotype , Synapses/metabolism , Synapses/physiology , Male
20.
Nat Commun ; 15(1): 3916, 2024 May 10.
Article in English | MEDLINE | ID: mdl-38729927

ABSTRACT

The UK observed a marked increase in scarlet fever and invasive group A streptococcal infection in 2022 with severe outcomes in children and similar trends worldwide. Here we report lineage M1UK to be the dominant source of invasive infections in this upsurge. Compared with ancestral M1global strains, invasive M1UK strains exhibit reduced genomic diversity and fewer mutations in two-component regulator genes covRS. The emergence of M1UK is dated to 2008. Following a bottleneck coinciding with the COVID-19 pandemic, three emergent M1UK clades underwent rapid nationwide expansion, despite lack of detection in previous years. All M1UK isolates thus-far sequenced globally have a phylogenetic origin in the UK, with dispersal of the new clades in Europe. While waning immunity may promote streptococcal epidemics, the genetic features of M1UK point to a fitness advantage in pathogenicity, and a striking ability to persist through population bottlenecks.


Subject(s)
COVID-19 , Phylogeny , Streptococcal Infections , Streptococcus pyogenes , Streptococcus pyogenes/genetics , Streptococcus pyogenes/pathogenicity , Streptococcus pyogenes/isolation & purification , United Kingdom/epidemiology , Humans , Streptococcal Infections/epidemiology , Streptococcal Infections/microbiology , COVID-19/epidemiology , Pandemics , Scarlet Fever/epidemiology , Scarlet Fever/microbiology , Mutation , Repressor Proteins/genetics , SARS-CoV-2/genetics , SARS-CoV-2/isolation & purification , Genome, Bacterial , Europe/epidemiology , Bacterial Proteins
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