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Journal of the Royal Society, Interface Jun 2024Cell polarity is important for controlling cell shape, motility and cell division processes. Vimentin intermediate filaments are important for cell migration and cell...
Cell polarity is important for controlling cell shape, motility and cell division processes. Vimentin intermediate filaments are important for cell migration and cell polarization in mesenchymal cells and assembly of vimentin and microtubule networks is dynamically coordinated, but the precise details of how vimentin mediates cell polarity remain unclear. Here, we characterize the effects of vimentin on the structure and function of the centrosome and the stability of microtubule filaments in wild-type and vimentin-null mouse embryonic fibroblasts. We find that vimentin mediates the structure of the pericentriolar material, promotes centrosome-mediated microtubule regrowth and increases the level of stable acetylated microtubules in the cell. Loss of vimentin also impairs centrosome repositioning during cell polarization and migration processes that occur during wound closure. Our results suggest that vimentin modulates centrosome structure and function as well as microtubule network stability, which has important implications for how cells establish proper cell polarization and persistent migration.
Topics: Animals; Centrosome; Mice; Vimentin; Cell Polarity; Microtubules; Acetylation; Cell Movement; Fibroblasts; Mice, Knockout
PubMed: 38835244
DOI: 10.1098/rsif.2023.0641 -
BMB Reports Jun 2024Microtubule acetylation has been shown to regulate actin filament dynamics by modulating signaling pathways that control actin organization, although the precise...
Microtubule acetylation has been shown to regulate actin filament dynamics by modulating signaling pathways that control actin organization, although the precise mechanisms remain unknown. In this study, we found that the downregulation of microtubule acetylation via the disruption ATAT1 (which encodes α-tubulin N-acetyltransferase 1) inhibited the expression of RhoA, a small GTPase involved in regulating the organization of actin filaments and the formation of stress fibers. Analysis of RHOA promoter and chromatin immunoprecipitation assays revealed that C/EBPβ is a major regulator of RHOA expression. Interestingly, the majority of C/EBPβ in ATAT1 knockout (KO) cells was found in the nucleus as a 27-kDa fragment (referred to as C/EBPβp27) lacking the N-terminus of C/EBPβ. Overexpression of a gene encoding a C/EBPβp27-mimicking protein via an N-terminal deletion in C/EBPβ led to competitive binding with wild-type C/EBPβ at the C/EBPβ binding site in the RHOA promoter, resulting in a significant decrease of RHOA expression. We also found that cathepsin L (CTSL), which is overexpressed in ATAT1 KO cells, is responsible for C/EBPβp27 formation in the nucleus. Treatment with a CTSL inhibitor led to the restoration of RHOA expression by downregulation of C/EBPβp27 and the invasive ability of ATAT1 KO MDA-MB-231 breast cancer cells. Collectively, our findings suggest that the downregulation of microtubule acetylation associated with ATAT1 deficiency suppresses RHOA expression by forming C/EBPβp27 in the nucleus through CTSL. We propose that CTSL and C/EBPβp27 may represent a novel therapeutic target for breast cancer treatment. [BMB Reports 2024; 57(6): 293-298].
Topics: Humans; CCAAT-Enhancer-Binding Protein-beta; rhoA GTP-Binding Protein; Down-Regulation; Acetyltransferases; Promoter Regions, Genetic; Acetylation; Cathepsin L; Microtubules; Cell Line, Tumor
PubMed: 38835115
DOI: 10.5483/BMBRep.2023-0230 -
Cell Death & Disease Jun 2024Keratinocyte proliferation and differentiation in epidermis are well-controlled and essential for reacting to stimuli such as ultraviolet light. Imbalance between...
Keratinocyte proliferation and differentiation in epidermis are well-controlled and essential for reacting to stimuli such as ultraviolet light. Imbalance between proliferation and differentiation is a characteristic feature of major human skin diseases such as psoriasis and squamous cell carcinoma. However, the effect of keratinocyte metabolism on proliferation and differentiation remains largely elusive. We show here that the gluconeogenic enzyme fructose-1,6-bisphosphatase 1 (FBP1) promotes differentiation while inhibits proliferation of keratinocyte and suppresses psoriasis development. FBP1 is identified among the most upregulated genes induced by UVB using transcriptome sequencing and is elevated especially in upper epidermis. Fbp1 heterozygous mice exhibit aberrant epidermis phenotypes with local hyperplasia and dedifferentiation. Loss of FBP1 promotes proliferation and inhibits differentiation of keratinocytes in vitro. Mechanistically, FBP1 loss facilitates glycolysis-mediated acetyl-CoA production, which increases histone H3 acetylation at lysine 9, resulting in enhanced transcription of proliferation genes. We further find that the expression of FBP1 is dramatically reduced in human psoriatic lesions and in skin of mouse imiquimod psoriasis model. Fbp1 deficiency in mice facilitates psoriasis-like skin lesions development through glycolysis and acetyl-CoA production. Collectively, our findings reveal a previously unrecognized role of FBP1 in epidermal homeostasis and provide evidence for FBP1 as a metabolic psoriasis suppressor.
Topics: Animals; Humans; Mice; Acetyl Coenzyme A; Acetylation; Cell Differentiation; Cell Proliferation; Disease Models, Animal; Fructose-Bisphosphatase; Glycolysis; Histones; Keratinocytes; Mice, Inbred C57BL; Psoriasis
PubMed: 38834617
DOI: 10.1038/s41419-024-06706-6 -
Cell Communication and Signaling : CCS Jun 2024Dysregulation in histone acetylation, a significant epigenetic alteration closely associated with major pathologies including cancer, promotes tumorigenesis,...
BACKGROUND
Dysregulation in histone acetylation, a significant epigenetic alteration closely associated with major pathologies including cancer, promotes tumorigenesis, inactivating tumor-suppressor genes and activating oncogenic pathways. AMP-activated protein kinase (AMPK) is a cellular energy sensor that regulates a multitude of biological processes. Although a number of studies have identified the mechanisms by which AMPK regulates cancer growth, the underlying epigenetic mechanisms remain unknown.
METHODS
The impact of metformin, an AMPK activator, on cervical cancer was evaluated through assessments of cell viability, tumor xenograft model, pan-acetylation analysis, and the role of the AMPK-PCAF-H3K9ac signaling pathway. Using label-free quantitative acetylproteomics and chromatin immunoprecipitation-sequencing (ChIP) technology, the activation of AMPK-induced H3K9 acetylation was further investigated.
RESULTS
In this study, we found that metformin, acting as an AMPK agonist, activates AMPK, thereby inhibiting the proliferation of cervical cancer both in vitro and in vivo. Mechanistically, AMPK activation induces H3K9 acetylation at epigenetic level, leading to chromatin remodeling in cervical cancer. This also enhances the binding of H3K9ac to the promoter regions of multiple tumor suppressor genes, thereby promoting their transcriptional activation. Furthermore, the absence of PCAF renders AMPK activation incapable of inducing H3K9 acetylation.
CONCLUSIONS
In conclusion, our findings demonstrate that AMPK mediates the inhibition of cervical cancer growth through PCAF-dependent H3K9 acetylation. This discovery not only facilitates the clinical application of metformin but also underscores the essential role of PCAF in AMPK activation-induced H3K9 hyperacetylation.
Topics: Uterine Cervical Neoplasms; Humans; Acetylation; Female; Histones; AMP-Activated Protein Kinases; Cell Proliferation; Animals; p300-CBP Transcription Factors; Metformin; Mice; Mice, Nude; Cell Line, Tumor; Enzyme Activation
PubMed: 38831454
DOI: 10.1186/s12964-024-01687-7 -
PloS One 2024Rheumatoid arthritis (RA) is a systemic immune-mediated disease characterized by joint inflammation and destruction. The disease typically affects small joints in the...
Rheumatoid arthritis (RA) is a systemic immune-mediated disease characterized by joint inflammation and destruction. The disease typically affects small joints in the hands and feet, later progressing to involve larger joints such as the knees, shoulders, and hips. While the reasons for these joint-specific differences are unclear, distinct epigenetic patterns associated with joint location have been reported. In this study, we evaluated the unique epigenetic landscapes of fibroblast-like synoviocytes (FLS) from hip and knee synovium in RA patients, focusing on the expression and regulation of Homeobox (HOX) transcription factors. These highly conserved genes play a critical role in embryonic development and are known to maintain distinct expression patterns in various adult tissues. We found that several HOX genes, especially HOXD10, were differentially expressed in knee FLS compared with hip FLS. Epigenetic differences in chromatin accessibility and histone marks were observed in HOXD10 promoter between knee and hip FLS. Histone modification, particularly histone acetylation, was identified as an important regulator of HOXD10 expression. To understand the mechanism of differential HOXD10 expression, we inhibited histone deacetylases (HDACs) with small molecules and siRNA. We found that HDAC1 blockade or deficiency normalized the joint-specific HOXD10 expression patterns. These observations suggest that epigenetic differences, specifically histone acetylation related to increased HDAC1 expression, play a crucial role in joint-specific HOXD10 expression. Understanding these mechanisms could provide insights into the regional aspects of RA and potentially lead to therapeutic strategies targeting specific patterns of joint involvement during the course of disease.
Topics: Humans; Arthritis, Rheumatoid; Homeodomain Proteins; Synoviocytes; Fibroblasts; Epigenesis, Genetic; Transcription Factors; Histone Deacetylase 1; Promoter Regions, Genetic; Knee Joint; Gene Expression Regulation; Histones; Acetylation; Hip Joint
PubMed: 38829908
DOI: 10.1371/journal.pone.0304530 -
Cell Reports Jun 2024Dendritic cell (DC) progenitors adapt their transcriptional program during development, generating different subsets. How chromatin modifications modulate these...
Dendritic cell (DC) progenitors adapt their transcriptional program during development, generating different subsets. How chromatin modifications modulate these processes is unclear. Here, we investigate the impact of histone deacetylation on DCs by genetically deleting histone deacetylase 1 (HDAC1) or HDAC2 in hematopoietic progenitors and CD11c-expressing cells. While HDAC2 is not critical for DC development, HDAC1 deletion impairs pro-pDC and mature pDC generation and affects ESAMcDC2 differentiation from tDCs and pre-cDC2s, whereas cDC1s are unchanged. HDAC1 knockdown in human hematopoietic cells also impairs cDC2 development, highlighting its crucial role across species. Multi-omics analyses reveal that HDAC1 controls expression, chromatin accessibility, and histone acetylation of the transcription factors IRF4, IRF8, and SPIB required for efficient development of cDC2 subsets. Without HDAC1, DCs switch immunologically, enhancing tumor surveillance through increased cDC1 maturation and interleukin-12 production, driving T helper 1-mediated immunity and CD8 T cell recruitment. Our study reveals the importance of histone acetylation in DC development and anti-tumor immunity, suggesting DC-targeted therapeutic strategies for immuno-oncology.
Topics: Dendritic Cells; Histone Deacetylase 1; Animals; Humans; Cell Differentiation; Mice; Mice, Inbred C57BL; Acetylation; Neoplasms; Histones; CD8-Positive T-Lymphocytes; Histone Deacetylase 2; Interleukin-12
PubMed: 38829740
DOI: 10.1016/j.celrep.2024.114308 -
Frontiers in Endocrinology 2024Ghrelin is a peptide hormone with various important physiological functions. The unique feature of ghrelin is its serine 3 acyl-modification, which is essential for...
Ghrelin is a peptide hormone with various important physiological functions. The unique feature of ghrelin is its serine 3 acyl-modification, which is essential for ghrelin activity. The major form of ghrelin is modified with n-octanoic acid (C8:0) by ghrelin O-acyltransferase. Various acyl modifications have been reported in different species. However, the underlying mechanism by which ghrelin is modified with various fatty acids remains to be elucidated. Herein, we report the purification of bovine, porcine, and equine ghrelins. The major active form of bovine ghrelin was a 27-amino acid peptide with an n-octanoyl (C8:0) modification at Ser3. The major active form of porcine and equine ghrelin was a 28-amino acid peptide. However, porcine ghrelin was modified with n-octanol (C8:0), whereas equine ghrelin was modified with n-butanol (C4:0) at Ser3. This study indicates the existence of structural divergence in ghrelin and suggests that it is necessary to measure the minor and major forms of ghrelin to fully understand its physiology.
Topics: Animals; Ghrelin; Horses; Cattle; Swine; Amino Acid Sequence; Acylation; Caprylates
PubMed: 38828411
DOI: 10.3389/fendo.2024.1411483 -
Archives of Razi Institute Dec 2023Remdesivir, a competitive inhibitor of viral RNA-dependent RNA polymerase, is the drug of choice for anti-COVID-19 treatment. However, the instability of these...
Remdesivir, a competitive inhibitor of viral RNA-dependent RNA polymerase, is the drug of choice for anti-COVID-19 treatment. However, the instability of these substances in plasma raises doubts about their therapeutic potency. Additionally, SARS-CoV-2-infected cells may exhibit a variety of antiviral behaviors due to intricate activation pathways. Therefore, this study aimed to develop a synthesis for the remdesivir derivative. The remdesivir derivative was synthesized using acetyl chloride as a reagent in a ratio of 1:3 in dichloromethane and tetrahydrofuran solvent at 30°C for 6 h. Thin-layer chromatography and spectrophotometers (1H NMR and 13C NMR) were used to identify the produced molecule, which was a brownish-yellow crystalline powder. The results of the synthesis yielded 0.8 gr (77.34%), and the Rf value of the remdesivir derivate was 0.54. The characterization with 1H NMR at δ2.5 ppm (3H, s) indicated the presence of a proton in the H-C-C=O structure caused by the substitution of the acetyl group in the remdesivir structure. The 13C NMR data indicated the presence of aromatic carbons, alkenes, C≡N, and carbon bonds with electronegative O. This remdesivir derivate chemical can be a potential candidate for an anti-COVID-19 drug that has more potency because it has substitutions of acetyl groups at positions 2' and 3' in the structure of remdesivir.
Topics: Alanine; Adenosine Monophosphate; Antiviral Agents; COVID-19 Drug Treatment; SARS-CoV-2; Acetylation; Humans
PubMed: 38828177
DOI: 10.32592/ARI.2023.78.6.1753 -
The Journal of Biological Chemistry May 2024Adaptive immune responses comprise the activation of T cells by peptide antigens that are presented by proteins of the Major Histocompatibility Complex (MHC) on the... (Review)
Review
Adaptive immune responses comprise the activation of T cells by peptide antigens that are presented by proteins of the Major Histocompatibility Complex (MHC) on the surface of an antigen-presenting cell. As a consequence of the T cell receptor interacting productively with a certain peptide-MHC complex, a specialized cell-cell junction known as the immunological synapse forms and is accompanied by changes in the spatiotemporal patterning and function of intracellular signaling molecules. Key modifications occurring at the cytoplasmic leaflet of the plasma and internal membranes in activated T cells comprise lipid switches that affect the binding and distribution of proteins within or near the lipid bilayer. Here, we describe two major classes of lipid switches that act at this critical water/membrane interface. Phosphoinositides are derived from phosphatidylinositol, an amphiphilic molecule that contains two fatty acid chains and a phosphate group that bridges the glycerol backbone to the carbohydrate inositol. The inositol ring can be variably (de-)phosphorylated by dedicated kinases and phosphatases, thereby creating phosphoinositide signatures that define the composition and properties of signaling molecules, molecular complexes, or whole organelles. Palmitoylation refers to the reversible attachment of the fatty acid palmitate to a substrate protein's cysteine residue. DHHC enzymes, named after the four conserved amino acids in their active site, catalyze this post-translational modification and thereby change the distribution of proteins at, between, and within membranes. T cells utilize these two types of molecular switches to adjust their properties to an activation process that requires changes in motility, transport, secretion, and gene expression.
PubMed: 38823638
DOI: 10.1016/j.jbc.2024.107428 -
Scientific Reports May 2024Sirtuin1 (SIRT1) activity decreases the tuberous sclerosis complex 2 (TSC2) lysine acetylation status, inhibiting the mechanistic target of rapamycin complex 1 (mTORC1)...
Sirtuin1 (SIRT1) activity decreases the tuberous sclerosis complex 2 (TSC2) lysine acetylation status, inhibiting the mechanistic target of rapamycin complex 1 (mTORC1) signalling and concomitantly, activating autophagy. This study analyzes the role of TSC2 acetylation levels in its translocation to the lysosome and the mitochondrial turnover in both mouse embryonic fibroblast (MEF) and in mouse insulinoma cells (MIN6) as a model of pancreatic β cells. Resveratrol (RESV), an activator of SIRT1 activity, promotes TSC2 deacetylation and its translocation to the lysosome, inhibiting mTORC1 activity. An improvement in mitochondrial turnover was also observed in cells treated with RESV, associated with an increase in the fissioned mitochondria, positive autophagic and mitophagic fluxes and an enhancement of mitochondrial biogenesis. This study proves that TSC2 in its deacetylated form is essential for regulating mTORC1 signalling and the maintenance of the mitochondrial quality control, which is involved in the homeostasis of pancreatic beta cells and prevents from several metabolic disorders such as Type 2 Diabetes Mellitus.
Topics: Tuberous Sclerosis Complex 2 Protein; Animals; Acetylation; Lysosomes; Mice; Mitochondria; Mechanistic Target of Rapamycin Complex 1; Sirtuin 1; Autophagy; Protein Transport; Resveratrol; Signal Transduction; Fibroblasts; Insulin-Secreting Cells; Cell Line, Tumor
PubMed: 38822085
DOI: 10.1038/s41598-024-63525-7