Nonalcoholic fatty liver disease (NAFLD) is characterized by elevated hepatic lipids caused by nonalcoholic factors, where histone lactylation is lately discovered as a modification driving disease progression. This research aimed to explore the role of histone 3 lysine 18 lactylation (H3K18lac) in NAFLD progression using a high-fat diet (HFD)-treated mouse model and free fatty acids (FFA)-treated L-02 cell lines. Lipids accumulation was screened via Oil Red O staining, real-time quantitative polymerase chain reaction (RT-qPCR), western blotting, and commercially available kits. Similarly, molecular mechanism was analyzed using immunoprecipitation (IP), dual-luciferase reporter assay, and RNA decay assay. Results indicated that FFA upregulated lactate dehydrogenase A (LDHA) and H3K18lac levels in L-02 cells. Besides, LDHA-mediated H3K18lac was enriched on the proximal promoter of methyltransferase 3 (METTL3), translating into an increased expression. Moreover, METTL3 or LDHA knockdown relieved lipid accumulation, decreased total cholesterol (TC) and triglyceride (TG) levels, and downregulated lipogenesis-related proteins in FFA-treated L-02 cell lines, in addition to enhancing the m6A and mRNA levels of stearoyl-coenzyme A desaturase 1 (SCD1). The m6A modification of SCD1 was recognized by YTH N6-methyladenosine RNA binding protein F1 (YTHDF1), resulting in enhanced mRNA stability. LDHA was found to be highly expressed in HFD-treated mice, where knocking down LDHA attenuated HFD-induced hepatic steatosis. These findings demonstrated that LDHA-induced H3K18lac promoted NAFLD progression, where LDHA-induced H3K18lac in METTL3 promoter elevated METTL3 expression, thereby promoting m6A methylation and stabilizing SCD1 via a YTHDF1-dependent manner. Keywords: Nonalcoholic fatty liver disease, LDHA, METTL3, YTHDF1, Histone lactylation.
- MeSH
- Adenosine * metabolism analogs & derivatives MeSH
- Diet, High-Fat adverse effects MeSH
- Histones * metabolism MeSH
- L-Lactate Dehydrogenase metabolism MeSH
- Humans MeSH
- Methyltransferases * metabolism genetics MeSH
- Mice, Inbred C57BL * MeSH
- Mice MeSH
- Non-alcoholic Fatty Liver Disease * metabolism pathology MeSH
- Disease Progression * MeSH
- RNA-Binding Proteins * metabolism genetics MeSH
- Stearoyl-CoA Desaturase * metabolism genetics MeSH
- Animals MeSH
- Check Tag
- Humans MeSH
- Male MeSH
- Mice MeSH
- Animals MeSH
- Publication type
- Journal Article MeSH
Histones are positively charged proteins found in the chromatin of eukaryotic cells. They regulate gene expression and are required for the organization and packaging of DNA within the nucleus. Histones are extremely conserved, allowing for transcription, replication, and repair. This review delves into their complex structure and function in DNA assembly, their role in nucleosome assembly, and the higher-order chromatin structures they generate. We look at the five different types of histone proteins: H1, H2A, H2B, H3, H4, and their variations. These histones bind with DNA to produce nucleosomes, the basic units of chromatin that are essential for compacting DNA and controlling its accessibility. Their dynamic control of chromatin accessibility has important implications for genomic stability and cellular activities. We elucidate regulatory mechanisms in both normal and pathological situations by investigating their structural features, diverse interaction mechanisms, and chromatin impact. In addition, we discuss the functions of histone post-translational modifications (PTMs) and their significance in various disorders. These alterations, which include methylation, acetylation, phosphorylation, and ubiquitination, are crucial in regulating histone function and chromatin dynamics. We specifically describe and explore the role of changed histones in the evolution of cancer, neurological disorders, sepsis, autoimmune illnesses, and inflammatory conditions. This comprehensive review emphasizes histone's critical role in genomic integrity and their potential as therapeutic targets in various diseases.
- MeSH
- Chromatin metabolism genetics chemistry MeSH
- DNA * metabolism chemistry MeSH
- Genome MeSH
- Histones * metabolism chemistry genetics MeSH
- Humans MeSH
- Neoplasms genetics metabolism MeSH
- Protein Processing, Post-Translational MeSH
- Animals MeSH
- Check Tag
- Humans MeSH
- Animals MeSH
- Publication type
- Journal Article MeSH
- Review MeSH
Spermatogenesis starts with the onset of puberty within the seminiferous epithelium of the testes. It is a complex process under intricate control of the endocrine system. Physiological regulations by steroid hormones in general and by estrogens in particular are due to their chemical nature prone to be disrupted by exogenous factors acting as endocrine disruptors (EDs). 17α-Ethynylestradiol (EE2) is an environmental pollutant with a confirmed ED activity and a well-known effect on spermatogenesis and chromatin remodeling in haploid germ cells. The aim of our study was to assess possible effects of two doses (2.5ng/ml; 2.5 μg/ml) of EE2 on both histone-to-protamine exchange and epigenetic profiles during spermatogenesis performing a multi/transgenerational study in mice. Our results demonstrated an impaired histone-to-protamine exchange with a significantly higher histone retention in sperm nuclei of exposed animals, when this process was accompanied by the changes of histone post-translational modifications (PTMs) abundancies with a prominent effect on H3K9Ac and partial changes in protamine 1 promoter methylation status. Furthermore, individual changes in molecular phenotypes were partially transmitted to subsequent generations, when no direct trans-generational effect was observed. Finally, the uncovered specific localization of the histone retention in sperm nuclei and their specific PTMs profile after EE2 exposure may indicate an estrogenic effect on sperm motility and early embryonic development via epigenetic mechanisms.
- MeSH
- Endocrine Disruptors pharmacology toxicity MeSH
- Epigenesis, Genetic * drug effects MeSH
- Ethinyl Estradiol * pharmacology MeSH
- Histones * metabolism MeSH
- Mice MeSH
- Protein Processing, Post-Translational drug effects MeSH
- Protamines * metabolism genetics MeSH
- Spermatogenesis * drug effects genetics MeSH
- Spermatozoa drug effects metabolism MeSH
- Testis * drug effects metabolism MeSH
- Animals MeSH
- Check Tag
- Male MeSH
- Mice MeSH
- Female MeSH
- Animals MeSH
- Publication type
- Journal Article MeSH
INTRODUCTION: Within oncology research, there is a high effort for new approaches to prevent and treat cancer as a life-threatening disease. Specific plant species that adapt to harsh conditions may possess unique properties that may be utilized in the management of cancer. HYPOTHESIS: Chokeberry fruit is rich in secondary metabolites with anti-cancer activities potentially useful in cancer prevention and treatment. AIMS OF THE STUDY AND METHODS: Based on mentioned hypothesis, the main goal of our study was to evaluate the antitumor effects of dietary administered Aronia melanocarpa L. fruit peels (in two concentrations of 0.3 and 3% [w/w]) in the therapeutic syngeneic 4T1 mouse adenocarcinoma model, the chemopreventive model of chemically induced mammary carcinogenesis in rats, a cell antioxidant assay, and robust in vitro analyses using MCF-7 and MDA-MB-231 cancer cells. RESULTS: The dominant metabolites in the A. melanocarpa fruit peel extract tested were phenolic derivatives classified as anthocyanins and procyanidins. In a therapeutic model, aronia significantly reduced the volume of 4T1 tumors at both higher and lower doses. In the same tumors, we noted a significant dose-dependent decrease in the mitotic activity index compared to the control. In the chemopreventive model, the expression of Bax was significantly increased by aronia at both doses. Additionally, aronia decreased Bcl-2 and VEGF levels, increasing the Bax/Bcl-2 ratio compared to the control group. The cytoplasmic expression of caspase-3 was significantly enhanced when aronia was administered at a higher dosage, in contrast to both the control group and the aronia group treated with a lower dosage. Furthermore, the higher dosage of aronia exhibited a significant reduction in the expression of the tumor stem cell marker CD133 compared to the control group. In addition, the examination of aronia`s epigenetic impact on tumor tissue through in vivo analyses revealed significant alterations in histone chemical modifications, specifically H3K4m3 and H3K9m3, miRNAs expression (miR155, miR210, and miR34a) and methylation status of tumor suppressor genes (PTEN and TIMP3). In vitro studies utilizing a methanolic extract of A.melanocarpa demonstrated significant anti-cancer properties in the MCF-7 and MDA-MB-231 cell lines. Various analyses, including Resazurin, cell cycle, annexin V/PI, caspase-3/7, Bcl-2, PARP, and mitochondrial membrane potential, were conducted in this regard. Additionally, the aronia extract enhanced the responsiveness to epirubicin in both cancer cell lines. CONCLUSION: This study is the first to analyze the antitumor effect of A. melanocarpa in selected models of experimental breast carcinoma in vivo and in vitro. The utilization of the antitumor effects of aronia in clinical practice is still minimal and requires precise and long-term clinical evaluations. Individualized cancer-type profiling and patient stratification are crucial for effectively implementing plant nutraceuticals within targeted anti-cancer strategies in clinical oncology.
- Publication type
- Journal Article MeSH
The establishment of long-lasting immunity against pathogens is facilitated by the germinal center (GC) reaction, during which B cells increase their antibody affinity and differentiate into antibody-secreting cells (ASC) and memory cells. These events involve modifications in chromatin packaging that orchestrate the profound restructuring of gene expression networks that determine cell fate. While several chromatin remodelers were implicated in lymphocyte functions, less is known about SMARCA5. Here, using ribosomal pull-down for analyzing translated genes in GC B cells, coupled with functional experiments in mice, we identified SMARCA5 as a key chromatin remodeler in B cells. While the naive B cell compartment remained unaffected following conditional depletion of Smarca5, effective proliferation during B cell activation, immunoglobulin class switching, and as a result GC formation and ASC differentiation were impaired. Single-cell multiomic sequencing analyses revealed that SMARCA5 is crucial for facilitating the transcriptional modifications and genomic accessibility of genes that support B cell activation and differentiation. These findings offer novel insights into the functions of SMARCA5, which can be targeted in various human pathologies.
- MeSH
- Adenosine Triphosphatases MeSH
- Lymphocyte Activation immunology MeSH
- B-Lymphocytes * metabolism immunology MeSH
- Cell Differentiation * MeSH
- Chromosomal Proteins, Non-Histone * metabolism genetics MeSH
- Mice, Inbred C57BL MeSH
- Mice MeSH
- Immunoglobulin Class Switching genetics MeSH
- Chromatin Assembly and Disassembly * MeSH
- Germinal Center * immunology metabolism MeSH
- Animals MeSH
- Check Tag
- Mice MeSH
- Animals MeSH
- Publication type
- Journal Article MeSH
BACKGROUND: Obesity is a major health burden. Preadipocytes proliferate and differentiate in mature adipocytes in the adipogenic process, which could be a potential therapeutic approach for obesity. Deficiency of SIRT6, a stress-responsive protein deacetylase and mono-ADP ribosyltransferase enzyme, blocks adipogenesis. Mutants of SIRT6 (N308K/A313S) were recently linked to the in the long lifespan Ashkenazi Jews. In this study, we aimed to clarify how these new centenarian-associated SIRT6 genetic variants affect adipogenesis at the transcriptional and epigenetic level. METHODS: We analyzed the role of SIRT6 wild-type (WT) or SIRT6 centenarian-associated mutant (N308K/A313S) overexpression in adipogenesis, by creating stably transduced preadipocyte cell lines using lentivirus on the 3T3-L1 model. Histone post-translational modifications (PTM: acetylation, methylation) and transcriptomic changes were analyzed by mass spectrometry (LC-MS/MS) and RNA-Seq, respectively, in 3T3-L1 adipocytes. In addition, the adipogenic process and related signaling pathways were investigated by bioinformatics and biochemical approaches. RESULTS: Overexpression of centenarian-associated SIRT6 mutant increased adipogenic differentiation to a similar extent compared to the WT form. However, it triggered distinct histone PTM profiles in mature adipocytes, with significantly higher acetylation levels, and activated divergent transcriptional programs, including those dependent on signaling related to the sympathetic innervation and to PI3K pathway. 3T3-L1 mature adipocytes overexpressing SIRT6 N308K/A313S displayed increased insulin sensitivity in a neuropeptide Y (NPY)-dependent manner. CONCLUSIONS: SIRT6 N308K/A313S overexpression in mature adipocytes ameliorated glucose sensitivity and impacted sympathetic innervation signaling. These findings highlight the importance of targeting SIRT6 enzymatic activities to regulate the co-morbidities associated with obesity.
- MeSH
- Adipogenesis * genetics MeSH
- 3T3-L1 Cells * MeSH
- Epigenesis, Genetic * genetics MeSH
- Histones metabolism genetics MeSH
- Humans MeSH
- Mutation MeSH
- Mice MeSH
- Obesity genetics metabolism MeSH
- Protein Processing, Post-Translational genetics MeSH
- Sirtuins * genetics metabolism MeSH
- Adipocytes * metabolism MeSH
- Animals MeSH
- Check Tag
- Humans MeSH
- Mice MeSH
- Animals MeSH
- Publication type
- Journal Article MeSH
Gene therapy is a focus of interest in both human and veterinary medicine, especially in recent years due to the potential applications of CRISPR/Cas9 technology. Another relatively new approach is that of epigenetic therapy, which involves an intervention based on epigenetic marks, including DNA methylation, histone post-translational modifications, and post-transcription modifications of distinct RNAs. The epigenome results from enzymatic reactions, which regulate gene expression without altering DNA sequences. In contrast to conventional CRISP/Cas9 techniques, the recently established methodology of epigenetic editing mediated by the CRISPR/dCas9 system is designed to target specific genes without causing DNA breaks. Both natural epigenetic processes and epigenetic editing regulate gene expression and thereby contribute to maintaining the balance between physiological functions and pathophysiological states. From this perspective, knowledge of specific epigenetic marks has immense potential in both human and veterinary medicine. For instance, the use of epigenetic drugs (chemical compounds with therapeutic potential affecting the epigenome) seems to be promising for the treatment of cancer, metabolic, and infectious diseases. Also, there is evidence that an epigenetic diet (nutrition-like factors affecting epigenome) should be considered as part of a healthy lifestyle and could contribute to the prevention of pathophysiological processes. In summary, epigenetic-based approaches in human and veterinary medicine have increasing significance in targeting aberrant gene expression associated with various diseases. In this case, CRISPR/dCas9, epigenetic targeting, and some epigenetic nutrition factors could contribute to reversing an abnormal epigenetic landscape to a healthy physiological state.
- Publication type
- Journal Article MeSH
- Review MeSH
... Uldrijan) -- 6.1 Epigenetic regulation of gene expression -- 6.1.1 DNA methylation -- 6.1.2 Histone modifications ...
First edition 227 stran : ilustrace ; 30 cm
- Conspectus
- Lékařské vědy. Lékařství
- Učební osnovy. Vyučovací předměty. Učebnice
- NML Fields
- biologie
- NML Publication type
- učebnice vysokých škol
The etiopathogenesis of mental disorders is not fully understood and accumulating evidence support that clinical symptomatology cannot be assigned to a single gene mutation, but it involves several genetic factors. More specifically, a tight association between genes and environmental risk factors, which could be mediated by epigenetic mechanisms, may play a role in the development of mental disorders. Several data suggest that epigenetic modifications such as DNA methylation, post-translational histone modification and interference of microRNA (miRNA) or long non-coding RNA (lncRNA) may modify the severity of the disease and the outcome of the therapy. Indeed, the study of these mechanisms may help to identify patients particularly vulnerable to mental disorders and may have potential utility as biomarkers to facilitate diagnosis and treatment of psychiatric disorders. This article summarizes the most relevant preclinical and human data showing how epigenetic modifications can be central to the therapeutic efficacy of antidepressant and/or antipsychotic agents, as possible predictor of drugs response.
NEUROD1 is a transcription factor that helps maintain a mature phenotype of pancreatic β cells. Disruption of Neurod1 during pancreatic development causes severe neonatal diabetes; however, the exact role of NEUROD1 in the differentiation programs of endocrine cells is unknown. Here, we report a crucial role of the NEUROD1 regulatory network in endocrine lineage commitment and differentiation. Mechanistically, transcriptome and chromatin landscape analyses demonstrate that Neurod1 inactivation triggers a downregulation of endocrine differentiation transcription factors and upregulation of non-endocrine genes within the Neurod1-deficient endocrine cell population, disturbing endocrine identity acquisition. Neurod1 deficiency altered the H3K27me3 histone modification pattern in promoter regions of differentially expressed genes, which resulted in gene regulatory network changes in the differentiation pathway of endocrine cells, compromising endocrine cell potential, differentiation, and functional properties.
