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EMBO Molecular Medicine Feb 2024Diabetic retinopathy (DR) is a leading cause of irreversible vision loss in working-age populations. Fat mass and obesity-associated protein (FTO) is an...
Diabetic retinopathy (DR) is a leading cause of irreversible vision loss in working-age populations. Fat mass and obesity-associated protein (FTO) is an N-methyladenosine (mA) demethylase that demethylates RNAs involved in energy homeostasis, though its influence on DR is not well studied. Herein, we detected elevated FTO expression in vitreous fibrovascular membranes of patients with proliferative DR. FTO promoted cell cycle progression and tip cell formation of endothelial cells (ECs) to facilitate angiogenesis in vitro, in mice, and in zebrafish. FTO also regulated EC-pericyte crosstalk to trigger diabetic microvascular leakage, and mediated EC-microglia interactions to induce retinal inflammation and neurodegeneration in vivo and in vitro. Mechanistically, FTO affected EC features via modulating CDK2 mRNA stability in an mA-YTHDF2-dependent manner. FTO up-regulation under diabetic conditions was driven by lactate-mediated histone lactylation. FB23-2, an inhibitor to FTO's mA demethylase activity, suppressed angiogenic phenotypes in vitro. To allow for systemic administration, we developed a nanoplatform encapsulating FB23-2 and confirmed its targeting and therapeutic efficiency in mice. Collectively, our study demonstrates that FTO is important for EC function and retinal homeostasis in DR, and warrants further investigation as a therapeutic target for DR patients.
Topics: Animals; Mice; Alpha-Ketoglutarate-Dependent Dioxygenase FTO; Cyclin-Dependent Kinase 2; Diabetes Mellitus; Diabetic Retinopathy; Endothelial Cells; Retina; RNA; Zebrafish
PubMed: 38297099
DOI: 10.1038/s44321-024-00025-1 -
Redox Biology Nov 2023Chronic obstructive pulmonary disease (COPD) is a significant global cause of morbidity and mortality currently. Long-term exposure of cigarette smoke (CS) inducing...
Chronic obstructive pulmonary disease (COPD) is a significant global cause of morbidity and mortality currently. Long-term exposure of cigarette smoke (CS) inducing persistent inflammation, small airway remodeling and emphysematous lung are the distinguishing features of COPD. Ferroptosis, occurred in lung epithelial cells has recently been reported to be associated with COPD pathogenesis. DNA dioxygenase ten-eleven translocation 2 (TET2) is an important demethylase and its genetic mutation is associated with low forced expiratory volume in 1 s (FEV) of lung function. However, its role in COPD remains elusive. Here, we found that TET2 regulates CS induced lipid peroxidation through demethylating glutathione peroxidase 4 (GPx4), thus alleviating airway epithelial cell ferroptosis in COPD. TET2 protein levels were mainly reduced in the airway epithelia of COPD patients, mouse models, and CS extract-treated bronchial epithelial cells. The deletion of TET2 triggered ferroptosis and further exaggerated CS-induced airway remodeling, inflammation, and emphysema in vivo. Moreover, we demonstrated that TET2 silencing intensified ferroptosis, while TET2 overexpression inhibited ferroptosis in airway epithelial cell treated with CSE. Mechanically, TET2 protected airway epithelial cells from CS-induced lipid peroxidation and ferroptosis through demethylating the promoter of glutathione peroxidase 4 (GPx4). Finally, co-administration of methylation inhibitor 5'-aza-2'-deoxycytidine (5-AZA) and the antioxidant N-acetyl-cysteine (NAC) have more protective effects on CS-induced COPD than either administration alone. Overall, our study reveals that TET2 is an essential modulator in the lipid peroxidation and ferroptosis of airway epithelial cell, and could act as a potential therapeutic target for CS-induced COPD.
Topics: Animals; Humans; Mice; Cigarette Smoking; Dioxygenases; DNA; DNA-Binding Proteins; Epithelial Cells; Ferroptosis; Inflammation; Lung; Phospholipid Hydroperoxide Glutathione Peroxidase; Pulmonary Disease, Chronic Obstructive
PubMed: 37812881
DOI: 10.1016/j.redox.2023.102916 -
Clinical and Translational Medicine Jul 2023The first-line therapy is effective for the treatment of primary immune thrombocytopenia (ITP); however, maintaining the long-term responses remains challenging....
BACKGROUND
The first-line therapy is effective for the treatment of primary immune thrombocytopenia (ITP); however, maintaining the long-term responses remains challenging. Low-dose decitabine (DAC) has been adopted to treat refractory ITP, while its role in macrophage polarization has not been fully understood. We aimed to investigate the mechanistic role of DAC in M2 macrophage polarization and evaluated its therapeutic effect in ITP.
METHODS
The M2 monocytes were identified by flow cytometry from peripheral blood mononuclear cells in healthy controls (HCs) and ITP patients. The expression of PPARγ, Arg-1, DNMT3b and NLRP3, together with IL-10 plasma levels was measured to examine its function. Bisulfite-sequencing PCR was used to evaluate the methylation status of PPARγ promoter, and the binding affinity of KLF4 was measured by Cut&Tag. A sh-PPARγ THP-1 cell line was created to verify if low-dose DAC-modulated M2 macrophage polarization was PPARγ-dependent. The passive ITP models were used to investigate the therapeutic effects of low-dose DAC and its role in modulating polarization and immunomodulatory function of macrophages. NLRP3 inflammasome and reactive oxygen species were also tested to understand the downstream of PPARγ.
RESULTS
The M2 monocytes with impaired immunoregulation were observed in ITP. After high-dose dexamethasone (HD-DXM) treatment, M2 monocytes increased significantly with the elevated expression of PPARγ, Arg-1 and IL-10 in CR patients. Low-dose DAC promoted M2 macrophage polarization in a PPARγ-dependent way via demethylating the promoter of PPARγ, especially the KLF4 binding sites. Low-dose DAC alleviated ITP mice by restoring the M1/M2 balance and fine-tuning immunomodulatory function of macrophages. The downstream of the PPARγ modulation of M2 macrophage polarization might physiologically antagonize NLRP3 inflammasome.
CONCLUSIONS
Low-dose DAC promoted M2 macrophage polarization due to the demethylation within the promoter of PPARγ, thus enhanced the KLF4 binding affinity in ITP.
Topics: Animals; Mice; PPAR gamma; Decitabine; Interleukin-10; Inflammasomes; Leukocytes, Mononuclear; NLR Family, Pyrin Domain-Containing 3 Protein; Purpura, Thrombocytopenic, Idiopathic; Macrophages
PubMed: 37488670
DOI: 10.1002/ctm2.1344 -
Nucleic Acids Research Mar 2024Albeit N1-Methyladenosine (m1A) RNA modification represents an important regulator of RNA metabolism, the role of m1A modification in carcinogenesis remains enigmatic....
Albeit N1-Methyladenosine (m1A) RNA modification represents an important regulator of RNA metabolism, the role of m1A modification in carcinogenesis remains enigmatic. Herein, we found that histone lactylation enhances ALKBH3 expression and simultaneously attenuates the formation of tumor-suppressive promyelocytic leukemia protein (PML) condensates by removing the m1A methylation of SP100A, promoting the malignant transformation of cancers. First, ALKBH3 is specifically upregulated in high-risk ocular melanoma due to excessive histone lactylation levels, referring to m1A hypomethylation status. Moreover, the multiomics analysis subsequently identified that SP100A, a core component for PML bodies, serves as a downstream candidate target for ALKBH3. Therapeutically, the silencing of ALKBH3 exhibits efficient therapeutic efficacy in melanoma both in vitro and in vivo, which could be reversed by the depletion of SP100A. Mechanistically, we found that YTHDF1 is responsible for recognition of the m1A methylated SP100A transcript, which increases its RNA stability and translational efficacy. Conclusively, we initially demonstrated that m1A modification is necessary for tumor suppressor gene expression, expanding the current understandings of dynamic m1A function during tumor progression. In addition, our results indicate that lactylation-driven ALKBH3 is essential for the formation of PML nuclear condensates, which bridges our knowledge of m1A modification, metabolic reprogramming, and phase-separation events.
Topics: Humans; AlkB Homolog 3, Alpha-Ketoglutarate-Dependent Dioxygenase; Demethylation; DNA Methylation; Histones; Melanoma; Promyelocytic Leukemia Protein; RNA; Transcription Factors; Antigens, Nuclear; Autoantigens; Eye Neoplasms
PubMed: 38118002
DOI: 10.1093/nar/gkad1193 -
Redox Biology Aug 2023There are no effective therapeutic targets or strategies that simultaneously inhibit tumour growth and promote cardiac function recovery. Here, we analyzed targets for...
There are no effective therapeutic targets or strategies that simultaneously inhibit tumour growth and promote cardiac function recovery. Here, we analyzed targets for cancer treatments and cardiac repair, with demethylation emerging as a common factor in these candidate lists. As DNA methyltransferase 1 (DNMT1) majorly responds to methylation, a natural compound library is screened, identifying dioscin as a novel agent targeted at DNMT1, widely used for heart diseases. Dioscin was found to reduce DNMT activities and inhibits growth in breast cancer cells. Combined with analyses of RNA-seq and MeDIP-seq, the promoters of antioxidant genes were demethylated after dioscin, recruiting NRF2 and elevating their expression. In Nrf2 knockout mice, the cardiac protection role of dioscin was blocked by Nrf2-loss. Furthermore, in tumour-bearing mice with hypertrophy, dioscin was observed to inhibit tumour growth and alleviate cardiac injury simultaneously. This study is the first to identify dioscin as a novel demethylation agent with dual functions of anti-cancer and cardio-protection.
Topics: Mice; Animals; Recovery of Function; NF-E2-Related Factor 2; Neoplasms; Demethylation; DNA Methylation
PubMed: 37343447
DOI: 10.1016/j.redox.2023.102785 -
Frontiers in Plant Science 2023Fruit ripening is a crucial stage in quality development, influenced by a diverse array of internal and external factors. Among these factors, epigenetic regulation... (Review)
Review
Fruit ripening is a crucial stage in quality development, influenced by a diverse array of internal and external factors. Among these factors, epigenetic regulation holds significant importance and has garnered substantial research attention in recent years. Here, this review aims to discuss the breakthrough in epigenetic regulation of tomato () fruit ripening, including DNA methylation, N-Methyladenosine mRNA modification, histone demethylation/deacetylation, and non-coding RNA. Through this brief review, we seek to enhance our understanding of the regulatory mechanisms governing tomato fruit ripening, while providing fresh insights for the precise modulation of these mechanisms.
PubMed: 37780524
DOI: 10.3389/fpls.2023.1269090 -
Journal of Advanced Research Dec 2023Poor wound healing is a significant complication of diabetes, which is commonly caused by neuropathy, trauma, deformities, plantar hypertension and peripheral arterial... (Review)
Review
BACKGROUND
Poor wound healing is a significant complication of diabetes, which is commonly caused by neuropathy, trauma, deformities, plantar hypertension and peripheral arterial disease. Diabetic foot ulcers (DFU) are difficult to heal, which makes patients susceptible to infections and can ultimately conduce to limb amputation or even death in severe cases. An increasing number of studies have found that epigenetic alterations are strongly associated with poor wound healing in diabetes.
AIM OF REVIEW
This work provides significant insights into the development of therapeutics for improving chronic diabetic wound healing, particularly by targeting and regulating DNA methylation and demethylation in DFU. Key scientific concepts of review: DNA methylation and demethylation play an important part in diabetic wound healing, via regulating corresponding signaling pathways in different breeds of cells, including macrophages, vascular endothelial cells and keratinocytes. In this review, we describe the four main phases of wound healing and their abnormality in diabetic patients. Furthermore, we provided an in-depth summary and discussion on how DNA methylation and demethylation regulate diabetic wound healing in different types of cells; and gave a brief summary on recent advances in applying cellular reprogramming techniques for improving diabetic wound healing.
Topics: Humans; Diabetic Foot; DNA Methylation; Endothelial Cells; Wound Healing; Demethylation; Diabetes Mellitus
PubMed: 36706989
DOI: 10.1016/j.jare.2023.01.009 -
Journal of Experimental & Clinical... Aug 2023Gemcitabine resistance has brought great challenges to the treatment of pancreatic cancer. The N6-methyladenosine (m6A) mutation has been shown to have a significant...
BACKGROUND
Gemcitabine resistance has brought great challenges to the treatment of pancreatic cancer. The N6-methyladenosine (m6A) mutation has been shown to have a significant regulatory role in chemosensitivity; however, it is not apparent whether gemcitabine resistance can be regulated by fat mass and obesity-associated protein (FTO).
METHODS
Cells with established gemcitabine resistance and tissues from pancreatic cancer patients were used to evaluate FTO expression. The biological mechanisms of the effects of FTO on gemcitabine resistant cells were investigated using CCK-8, colony formation assay, flow cytometry, and inhibitory concentration 50. Immunoprecipitation/mass spectrometry, MeRIP-seq, RNA sequencing and RIP assays, RNA stability, luciferase reporter, and RNA pull down assays were employed to examine the mechanism of FTO affecting gemcitabine resistant pancreatic cancer cells.
RESULTS
The results revealed that FTO was substantially expressed in cells and tissues that were resistant to gemcitabine. Functionally, the gemcitabine resistance of pancreatic cancer could be enhanced by FTO, while its depletion inhibited the growth of gemcitabine resistant tumor cells in vivo. Immunoprecipitation/mass spectrometry showed that the FTO protein can be bound to USP7 and deubiquitinated by USP7, leading to the upregulation of FTO. At the same time, FTO knockdown significantly decreased the expression level of NEDD4 in an m6A-dependent manner. RNA pull down and RNA immunoprecipitation verified YTHDF2 as the reader of NEDD4, which promoted the chemoresistance of gemcitabine resistant cells. FTO knockdown markedly increased the PTEN expression level in an NEDD4-dependent manner and influenced the chemosensitivity to gemcitabine through the PI3K/AKT pathway in pancreatic cancer cells.
CONCLUSION
In conclusion, we found that gemcitabine resistance in pancreatic cancer can be influenced by FTO that demethylates NEDD4 RNA in a m6A-dependent manner, which then influences the PTEN expression level and thereby affects the PI3K/AKT pathway. We also identified that the FTO level can be upregulated by USP7.
Topics: Humans; Gemcitabine; Phosphatidylinositol 3-Kinases; Proto-Oncogene Proteins c-akt; Ubiquitin-Specific Peptidase 7; RNA Stability; Pancreatic Neoplasms; PTEN Phosphohydrolase; Alpha-Ketoglutarate-Dependent Dioxygenase FTO
PubMed: 37605223
DOI: 10.1186/s13046-023-02792-0 -
Theranostics 2024Epigenetics refers to the reversible process through which changes in gene expression occur without changing the nucleotide sequence of DNA. The process is currently... (Review)
Review
Epigenetics refers to the reversible process through which changes in gene expression occur without changing the nucleotide sequence of DNA. The process is currently gaining prominence as a pivotal objective in the treatment of cancers and other ailments. Numerous drugs that target epigenetic mechanisms have obtained approval from the Food and Drug Administration (FDA) for the therapeutic intervention of diverse diseases; many have drawbacks, such as limited applicability, toxicity, and resistance. Since the discovery of the first proteolysis-targeting chimeras (PROTACs) in 2001, studies on targeted protein degradation (TPD)-encompassing PROTACs, molecular glue (MG), hydrophobic tagging (HyT), degradation TAG (dTAG), Trim-Away, a specific and non-genetic inhibitor of apoptosis protein (IAP)-dependent protein eraser (SNIPER), antibody-PROTACs (Ab-PROTACs), and other lysosome-based strategies-have achieved remarkable progress. In this review, we comprehensively highlight the small-molecule degraders beyond PROTACs that could achieve the degradation of epigenetic proteins (including bromodomain-containing protein-related targets, histone acetylation/deacetylation-related targets, histone methylation/demethylation related targets, and other epigenetic targets) via proteasomal or lysosomal pathways. The present difficulties and forthcoming prospects in this domain are also deliberated upon, which may be valuable for medicinal chemists when developing more potent, selective, and drug-like epigenetic drugs for clinical applications.
Topics: United States; Humans; Histones; Protein Processing, Post-Translational; Proteolysis; Epigenesis, Genetic; Lysosomes; Neoplasms, Squamous Cell
PubMed: 38389844
DOI: 10.7150/thno.92526 -
Redox Biology Apr 2024Doxorubicin (DOX)-induced cardiotoxicity seriously limits its clinical applicability, and no therapeutic interventions are available. Ferroptosis, an iron-dependent...
Doxorubicin (DOX)-induced cardiotoxicity seriously limits its clinical applicability, and no therapeutic interventions are available. Ferroptosis, an iron-dependent regulated cell death characterised by lipid peroxidation, plays a pivotal role in DOX-induced cardiotoxicity. N6-methyladenosine (m6A) methylation is the most frequent type of RNA modification and involved in DOX-induced ferroptosis, however, its underlying mechanism remains unclear. P21 was recently found to inhibit ferroptosis by interacting with Nrf2 and is regulated in a P53-dependent or independent manner, such as through m6A modification. In the present study, we investigated the mechanism underlying m6A modification in DOX-induced ferroptosis by focusing on P21. Our results show that fat mass and obesity-associated protein (FTO) down-regulation was associated with DOX-induced cardiotoxicity. FTO over-expression significantly improved cardiac function and cell viability in DOX-treated mouse hearts and H9C2 cells. FTO over-expression significantly inhibited DOX-induced ferroptosis, and the Fer-1 inhibition of ferroptosis significantly reduced DOX-induced cardiotoxicity. P21 was significantly upregulated by FTO and activated Nrf2, playing a crucial role in the anti-ferroptotic effect. FTO upregulated P21/Nrf2 in a P53-dependent manner by mediating the demethylation of P53 or in a P53-independent manner by mediating P21/Nrf2 directly. Human antigen R (HuR) is crucial for FTO-mediated regulation of ferroptosis and P53-P21/Nrf2. Notably, we also found that P21 inhibition in turn inhibited HuR and P53 expression, while HuR inhibition further inhibited FTO expression. RNA immunoprecipitation assay showed that HuR binds to the transcripts of FTO and itself. Collectively, FTO inhibited DOX-induced ferroptosis via P21/Nrf2 activation by mediating the m6A demethylation of P53 or P21/Nrf2 in a HuR-dependent manner and constituted a positive feedback loop with HuR and P53-P21. Our findings provide novel insight into key functional mechanisms associated with DOX-induced cardiotoxicity and elucidate a possible therapeutic approach.
Topics: Mice; Animals; Humans; Cardiotoxicity; Tumor Suppressor Protein p53; NF-E2-Related Factor 2; Ferroptosis; Myocytes, Cardiac; Doxorubicin; RNA; Alpha-Ketoglutarate-Dependent Dioxygenase FTO; Adenine
PubMed: 38316068
DOI: 10.1016/j.redox.2024.103067