bims-rimeca 2023-06-18 papers

bims-rimeca

Biomed News

on RNA methylation in cancer

Issue of 2023–06–18
25 papers selected by
Sk Ramiz Islam, Saha Institute of Nuclear Physics

FTO promotes the progression of cervical cancer by regulating the N6-methyladenosine modification of ZEB1 and Myc.
N6-methyladenosine modification of FZR1 mRNA promotes gemcitabine resistance in pancreatic cancer.
FTO alleviates cerebral ischemia/reperfusion-induced neuroinflammation by decreasing cGAS mRNA stability in an m6A-dependent manner.
METTL14-mediated m6A modification of TNFAIP3 involved in inflammation in patients with active rheumatoid arthritis.
Oxidative Stress Induced by Arsenite is Involved in YTHDF2 Phase Separation.
METTL14 is decreased and regulates m6 A modification of α-synuclein in Parkinson's disease.
Microenvironment modulation by key regulators of RNA N6-methyladenosine modification in respiratory allergic diseases.
Targeting IGF2BP3 in Cancer.
Therapeutic m6A Eraser ALKBH5 mRNA-Loaded Exosome-Liposome Hybrid Nanoparticles Inhibit Progression of Colorectal Cancer in Preclinical Tumor Models.
m6A RNA methylation: A dynamic regulator of cardiac muscle and extracellular matrix.
HNRNPA2B1-mediated m6A modification of lncRNA MEG3 facilitates tumorigenesis and metastasis of non-small cell lung cancer by regulating miR-21-5p/PTEN axis.
METTL3 Promotes Osteo/Odontogenic Differentiation of Stem Cells by Inhibiting miR-196b-5p Maturation.
As3MT via consuming SAM is involved in arsenic-induced nonalcoholic fatty liver disease by blocking m6A-mediated miR-142-5p maturation.
M1A and m7G modification-related genes are potential biomarkers for survival prognosis and for deciphering the tumor immune microenvironment in esophageal squamous cell carcinoma.
Ythdf2 regulates cardiac remodeling through its mRNA target transcripts.
OCTN2 enhances PGC-1α-mediated fatty acid oxidation and OXPHOS to support stemness in hepatocellular carcinoma.
The Emerging, Multifaceted Role of WTAP in Cancer and Cancer Therapeutics.
Astragaloside IV alleviates neuronal ferroptosis in ischemic stroke by regulating fat mass and obesity-associated-N6-methyladenosine-acyl-CoA synthetase long-chain family member 4 axis.
Vital roles of m5C RNA modification in cancer and immune cell biology.
PARP-dependent and NAT10-independent acetylation of N4-cytidine in RNA appears in UV-damaged chromatin.
5-Methylcytosine-related lncRNAs: predicting prognosis and identifying hot and cold tumor subtypes in head and neck squamous cell carcinoma.
Mechanistic exploration on neurodevelopmental toxicity induced by upregulation of alkbh5 targeted by triclosan exposure to larval zebrafish.
Splicing factor TRA2A contributes to esophageal cancer progression via a noncanonical role in lncRNA m6 A methylation.
IGF2BP3-induced activation of EIF5B contributes to progression of hepatocellular carcinoma cells.
NAT10 regulates the LPS-induced inflammatory response via the NOX2-ROS-NF-κB pathway in macrophages.

Mol Carcinog. 2023 Jun 12.

FTO promotes the progression of cervical cancer by regulating the N6-methyladenosine modification of ZEB1 and Myc.

Aihong Wang, Canhui Jin, Ying Wang, Juanjuan Yu, Ruifang Wang, Xiaoyu Tian.

  Cervical cancer is a malignant tumor of the cervix in women. However, the pathogenesis of cervical cancer has not been fully understood. N6-methyladenosine (m6A) is a kind of RNA modification that plays a critical role in cancer development. We aim to find out the possible m6A regulatory mechanism of the fat mass and obesity-associated protein (FTO) on the development of cervical cancer. The proliferative capacity of cervical cancer cells was detected by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl-2H-tetrazolium bromide (MTT), colony formation and 5-ethynyl-20-deoxyuridine (EdU) staining. The migration and invasion of cervical cancer cells were determined by transwell assay. The function of FTO on tumor growth was evaluated by a xenograft model. We found that FTO was highly expressed in cervical cancer tissues and cell lines. FTO silencing suppressed the proliferation, migration, and invasion of cervical cancer cells. Mechanistically, FTO modulated the m6A modification of Zinc finger E-box binding homeobox 1 (ZEB1) and Myelocytomatosis oncogene (Myc). Furthermore, ZEB1 and Myc overexpression reverse the effect of FTO knockdown on the malignant behaviors of cervical cancer cells. FTO may be a novel therapeutic target for cervical cancer.

Keywords:  FTO; Myc; ZEB1; cervical carcinoma; m6A

DOI:  https://doi.org/10.1002/mc.23559
Cancer Res. 2023 Jun 16. pii: CAN-22-3346. [Epub ahead of print]

N6-methyladenosine modification of FZR1 mRNA promotes gemcitabine resistance in pancreatic cancer.

Jiachun Su, Rui Li, Ziming Chen, Shaoqiu Liu, Hongzhe Zhao, Shuang Deng, Lingxing Zeng, Zilan Xu, Sihan Zhao, Yifan Zhou, Mei Li, Xiaowei He, Ji Liu, Chunling Xue, Ruihong Bai, Lisha Zhuang, Quanbo Zhou, Shaoping Zhang, Rufu Chen, Xudong Huang, Dongxin Lin, Jian Zheng, Jialiang Zhang.

The therapeutic options for treating pancreatic ductal adenocarcinoma (PDAC) are limited, and resistance to gemcitabine, a cornerstone of PDAC chemotherapy regimens, remains a major challenge. N6-methyladenosine (m6A) is a prevalent modification in mRNA that has been linked to diverse biological processes in human diseases. Herein, by characterizing the global m6A profile in a panel of gemcitabine-sensitive and gemcitabine-insensitive PDAC cells, we identified a key role for elevated m6A modification of the master G0/G1 regulator FZR1 in regulating gemcitabine sensitivity. Targeting FZR1 m6A modification augmented the response to gemcitabine treatment in gemcitabine-resistant PDAC cells both in vitro and in vivo. Mechanistically, GEMIN5 was identified as a novel m6A mediator that specifically bound to m6A-modified FZR1 and recruited the eIF3 translation initiation complex to accelerate FZR1 translation. FZR1 upregulation maintained the G0/G1 quiescent state and suppressed gemcitabine sensitivity in PDAC cells. Clinical analysis further demonstrated that both high levels of FZR1 m6A modification and FZR1 protein corresponded to poor response to gemcitabine. These findings reveal the critical function of m6A modification in regulating gemcitabine sensitivity in PDAC and identify the FZR1/GEMIN5 axis as a potential target to enhance gemcitabine response.

DOI: https://doi.org/10.1158/0008-5472.CAN-22-3346
Cell Signal. 2023 Jun 13. pii: S0898-6568(23)00165-1. [Epub ahead of print] 110751

FTO alleviates cerebral ischemia/reperfusion-induced neuroinflammation by decreasing cGAS mRNA stability in an m6A-dependent manner.

Zhiyong Yu, Linbo Zheng, Yan Geng, Yuting Zhang, Yupeng Wang, Guoxing You, Mingsheng Cai, Meili Li, Xiao Cheng, Jie Zan.

  Microglia-mediated inflammation is a major contributor to the brain damage in cerebral ischemia and reperfusion (I/R) injury, and N6-Methyladenosine (m6A) has been implicated in cerebral I/R injury. Here, we explored whether m6A modification is associated with microglia-mediated inflammation in cerebral I/R injury and its underlying regulatory mechanism using an in vivo mice model of intraluminal middle cerebral artery occlusion/reperfusion (MCAO/R) and in vitro models of primary isolated microglia and BV2 microglial cells subjected to oxygen-glucose deprivation and reoxygenation (OGD/R) were used. We found microglial m6A modification increased and microglial fat mass and obesity-associated protein (FTO) expression decreased in cerebral I/R injury in vivo and in vitro. Inhibition of m6A modification by intraperitoneal injection of Cycloleucine (Cyc) in vivo or transfection of FTO plasmid in vitro significantly alleviated brain injury and microglia-mediated inflammatory response. Through Methylated RNA immunoprecipitation sequencing (MeRIP-Seq), RNA sequencing (RNA-Seq) and western blotting, we found that m6A modification promoted cerebral I/R-induced microglial inflammation via increasing cGAS mRNA stability to aggravate Sting/NF-κB signaling. In conclusion, this study deepens our understanding on the relationship of m6A modification and microglia-mediated inflammation in cerebral I/R injury, and insights a novel m6A-based therapeutic for inhibiting inflammatory response against ischemic stroke.

Keywords:  Cerebral ischemia and reperfusion injury; Cyclic GMP-AMP synthase; Fat mass and obesity-associated protein; Inflammation; N6-Methyladenosine

DOI:  https://doi.org/10.1016/j.cellsig.2023.110751
Arthritis Rheumatol. 2023 Jun 16.

METTL14-mediated m6A modification of TNFAIP3 involved in inflammation in patients with active rheumatoid arthritis.

Jifeng Tang, Ziqing Yu, Jinfang Xia, Renquan Jiang, Shuhui Chen, Detai Ye, Huiming Sheng, Jinpiao Lin.

OBJECTIVE: The aim of the study was to investigate the role of N6-Methyladenosine (m6A) modification in the progression of rheumatoid arthritis (RA).
METHODS: Peripheral blood mononuclear cells (PBMCs) from RA patients and healthy controls were collected. The expression of m6A-modification related proteins and m6A levels were detected using PCR, western blot and m6A ELISA. The roles of methyltransferase-like 14 (METTL14) in the regulation of inflammation in RA was explored using MeRIP-sequencing and RNA immunoprecipitation assays. Collagen antibody-induced arthritis (CAIA) mice were used as an in vivo model to study the role of METTL14 in the inflammation progression of RA.
RESULTS: We found that m6A writer METTL14 and m6A levels were decreased in PBMCs of active RA patients, and correlated negatively with the disease activity score using 28 joint counts (DAS28). Knockdown of METTL14 down-regulated m6A, and promoted the secretion of inflammatory cytokines IL-6 and IL-17 in PBMCs of RA patients. Consistently, METTL14 knockdown promoted joint inflammation accompanied by upregulation of IL-6 and IL-17 in CAIA mice. MeRIP-sequencing and functional studies confirmed that tumor necrosis factor alpha induced protein 3 (TNFAIP3), a key suppressor of NF-κB inflammatory pathway, was involved in m6A-regulated PBMCs. Mechanistic investigations revealed that m6A affected TNFAIP3 expression by regulation of mRNA stability and translocation in TNFAIP3 protein-coding regions (CDS).
CONCLUSIONS: Our study highlights the critical roles of m6A on regulation of inflammation in RA progression. Treatment strategies targeting m6A modification may represent a new option for management of RA. This article is protected by copyright. All rights reserved.

DOI: https://doi.org/10.1002/art.42629
Biol Trace Elem Res. 2023 Jun 13.

Oxidative Stress Induced by Arsenite is Involved in YTHDF2 Phase Separation.

Jin Man, Qian Zhang, Tianhe Zhao, Donglei Sun, Weilian Sun, Keyan Long, Zunzhen Zhang.

  YTH N6-methyladenosine RNA binding protein 2 (YTHDF2) undergoes phase separation in response to the stimulation of high concentration of arsenite, suggesting that oxidative stress, the major mechanism of arsenite toxicity, may play a role in YTHDF2 phase separation. However, whether arsenite-induced oxidative stress is involved in phase separation of YTHDF2 has yet to be established. To explore the effect of arsenite-induced oxidative stress on YTHDF2 phase separation, the levels of oxidative stress, YTHDF2 phase separation, and N6-methyladenosine (m6A) in human keratinocytes were detected after exposure to various concentrations of sodium arsenite (0-500 µM; 1 h) and antioxidant N-acetylcysteine (0-10 mM; 2 h). We found that arsenite promoted oxidative stress and YTHDF2 phase separation in a concentration-dependent manner. In contrast, pretreatment with N-acetylcysteine significantly relieved arsenate-induced oxidative stress and inhibited YTHDF2 phase separation. As one of the key factors to YTHDF2 phase separation, N6-methyladenosine (m6A) levels in human keratinocytes were significantly increased after arsenite exposure, accompanied by upregulation of m6A methylesterase levels and downregulation of m6A demethylases levels. On the contrary, N-acetylcysteine mitigated the arsenite-induced increase of m6A and m6A methylesterase and the arsenite-induced decrease in m6A demethylase. Collectively, our study firstly revealed that oxidative stress induced by arsenite plays an important role in YTHDF2 phase separation driven by m6A modification, which provides new insights into the arsenite toxicity from the phase-separation perspective.

Keywords:  Arsenite; N6-methyladenosine; Oxidative stress; Phase separation

DOI:  https://doi.org/10.1007/s12011-023-03728-7
J Neurochem. 2023 Jun 13.

METTL14 is decreased and regulates m6 A modification of α-synuclein in Parkinson's disease.

Honghu He, Qinxin Zhang, Jiajia Liao, Jiang Lei, Man Luo, Jianyi Huang, Meiling Chen, Yuefei Shen, Jin Wang, Pingyi Xu, Yousheng Xiao.

  N6-methyladenosine (m6A), an emerging modification of messenger RNA, has been implicated in many biological processes. However, its role in Parkinson's disease (PD) remains largely unknown. Here, we investigated the role of m6A modification and its underlying mechanism in PD. First, 86 individuals with PD and 86 healthy controls were recruited from a pilot multicenter cohort. Levels of m6A and its modulators in peripheral blood mononuclear cells of patients with PD and controls were measured using an m6A RNA methylation quantification kit and quantitative real-time PCR. The underlying mechanism of m6A modification in PD was investigated in vitro through RNA immunoprecipitation assay, RNA stability assay, gene silencing or overexpression, western blot, and confocal immunoassay. The results show that mRNA levels of m6A, METTL3, METTL14, and YTHDF2 in patients with PD were significantly lower than in healthy controls, and METTL14 was the main factor involved in abnormal m6A modification. Area under the curve (AUC) analysis suggests METTL14 may provide excellent diagnostic capability for PD, especially when combined with plasma α-synuclein (α-syn). Spearman correlation analysis identified that METTL14 was moderately negatively correlated with plasma α-syn and the motor function of PD. Mechanistic experiments demonstrated that Mettl14 targets and regulates the expression of the α-syn gene using its methylation function. Overexpression of Mettl14 dramatically increased m6 A modification of α-syn mRNA and weakened its stability. Further results suggest that α-syn mRNA was modified by Mettl14 binding of an m6 A motif in the coding region of α-syn mRNA, while the reading protein Ythdf2 was involved in recognizing m6 A-modified α-syn mRNA. Taken together, our results reveal the potential of METTL14 as a novel diagnostic biomarker for PD and identify modification of pathogenic α-syn protein by METTL14 via an m6 A-YTHDF2-dependent mechanism.

Keywords:  METTL14; Parkinson's disease; biomarker; m6A modification; α-Synuclein

DOI:  https://doi.org/10.1111/jnc.15882
BMC Pulm Med. 2023 Jun 16. 23(1): 210

Microenvironment modulation by key regulators of RNA N6-methyladenosine modification in respiratory allergic diseases.

Yuting Wang, Jiaxi Wang, Zhanfeng Yan, Siming Liu, Wenlong Xu.

   BACKGROUND: RNA N6-methyladenosine (m6A) regulators are considered post-transcriptional regulators that affect several biological functions, and their role in immunity, in particular, is emerging. However, the role of m6A regulators in respiratory allergic diseases remains unclear. Therefore, we aimed to investigate the role of key m6A regulators in mediating respiratory allergic diseases and immune microenvironment infiltration characteristics.
METHODS: We downloaded gene expression profiles of respiratory allergies from the Gene Expression Omnibus (GEO) database and we performed hierarchical clustering, difference analysis, and construction of predictive models to identify hub m6A regulators that affect respiratory allergies. Next, we investigate the underlying biological mechanisms of key m6A regulators by performing PPI network analysis, functional enrichment analysis, and immune microenvironment infiltration analysis. In addition, we performed a drug sensitivity analysis on the key m6A regulator, hoping to be able to provide some implications for clinical medication.
RESULTS: In this study, we identified four hub m6A regulators that affect the respiratory allergy and investigated the underlying biological mechanisms. In addition, studies on the characteristics of immune microenvironment infiltration revealed that the expression of METTL14, METTL16, and RBM15B correlated with the infiltration of the mast and Th2 cells in respiratory allergy, and METTL16 expression was found to be significantly negatively correlated with macrophages for the first time (R = -0.53, P < 0.01). Finally, a key m6A regulator, METTL14, was screened by combining multiple algorithms. In addition, by performing a drug sensitivity analysis on METTL14, we hypothesized that it may play an important role in the improvement of allergic symptoms in the upper and lower airways with topical nasal glucocorticoids.
CONCLUSIONS: Our findings suggest that m6A regulators, particularly METTL14, play a crucial role in the development of respiratory allergic diseases and the infiltration of immune cells. These results may provide insight into the mechanism of action of methylprednisolone in treating respiratory allergic diseases.

Keywords:  Allergic rhinitis; Asthma; Immune microenvironment; METTL14; Respiratory allergic diseases; m6A modification; m6A regulators

DOI:  https://doi.org/10.1186/s12890-023-02499-0
Int J Mol Sci. 2023 May 29. pii: 9423. [Epub ahead of print]24(11):

Targeting IGF2BP3 in Cancer.

Xin Liu, Jiayu Chen, Wenliang Chen, Yangtao Xu, Yang Shen, Ximing Xu.

  RNA-binding proteins (RBPs) can regulate multiple pathways by binding to RNAs, playing a variety of functions, such as localization, stability, and immunity. In recent years, with the development of technology, researchers have discovered that RBPs play a key role in the N6-methyladenosine (m6A) modification process. M6A methylation is the most abundant form of RNA modification in eukaryotes, which is defined as methylation on the sixth N atom of adenine in RNA. Insulin-like growth factor 2 mRNA-binding protein 3 (IGF2BP3) is one of the components of m6A binding proteins, which plays an important role in decoding m6A marks and performing various biological functions. IGF2BP3 is abnormally expressed in many human cancers, often associated with poor prognosis. Here, we summarize the physiological role of IGF2BP3 in organisms and describe its role and mechanism in tumors. These data suggest that IGF2BP3 may be a valuable therapeutic target and prognostic marker in the future.

Keywords:  IGF2BP3; cancer-promoting factor; m6A binding protein; radiosensitivity; tumor immunity

DOI:  https://doi.org/10.3390/ijms24119423
ACS Nano. 2023 Jun 13.

Therapeutic m6A Eraser ALKBH5 mRNA-Loaded Exosome-Liposome Hybrid Nanoparticles Inhibit Progression of Colorectal Cancer in Preclinical Tumor Models.

Shenshen Wu, Jun Yun, Weiyan Tang, Giuseppe Familiari, Michela Relucenti, Jiong Wu, Xiaobo Li, Hanqing Chen, Rui Chen.

  Although therapeutic targets have been developed for colorectal cancer (CRC) therapy, the therapeutic effects are not ideal and the survival rate for CRC patients remains poor. Therefore, it is crucial to recognize a specific target and develop an efficacious delivery system for CRC therapy. Herein, we demonstrate that reduced ALKBH5 mediates aberrant m6A modification and tumor progression in CRC. Mechanically, histone deacetylase 2-mediated H3K27 deacetylation inhibits ALKBH5 transcription in CRC, whereas ectopic ALKBH5 expression decreases tumorigenesis of CRC cells and protects mice from colitis-associated tumor development. Further, METTL14/ALKBH5/IGF2BPs combine to modulate JMJD8 stability in an m6A-dependent manner, which increases glycolysis and accelerates the development of CRC by enhancing the enzymatic activity of PKM2. Moreover, ALKBH5 mRNA-loaded folic acid-modified exosome-liposome hybrid nanoparticles were synthesized and significantly inhibit the progression of CRC in preclinical tumor models by modulating the ALKBH5/JMJD8/PKM2 axis and inhibiting glycolysis. Overall, our research confirms the crucial function of ALKBH5 in regulating the m6A status in CRC and provides a direct preclinical approach for using ALKBH5 mRNA nanotherapeutics for CRC.

Keywords:  ALKBH5; CRC; RNA methylation; exosome−liposome hybrid nanoparticles; mRNA therapeutics

DOI:  https://doi.org/10.1021/acsnano.3c03050
Curr Opin Physiol. 2022 Aug;pii: 100561. [Epub ahead of print]28

m6A RNA methylation: A dynamic regulator of cardiac muscle and extracellular matrix.

Charles P Rabolli, Federica Accornero.

Post-transcriptional modifications encompass a large group of RNA alterations that control gene expression. Methylation of the N6-Adenosine (m6A) of mRNA is a prevalent modification which alters the life cycle of transcripts. The roles that m6A play in regulating cardiac homeostasis and injury response are an active area of investigation, but it is clear that this chemical modification is a critical controller of fibroblast to myofibroblast transition, cardiomyocyte hypertrophy and division, and the structure and function of the extracellular matrix. Here we discuss the latest findings of m6A in cardiac muscle and matrix.

DOI: https://doi.org/10.1016/j.cophys.2022.100561
J Transl Med. 2023 Jun 12. 21(1): 382

HNRNPA2B1-mediated m6A modification of lncRNA MEG3 facilitates tumorigenesis and metastasis of non-small cell lung cancer by regulating miR-21-5p/PTEN axis.

Ke Li, Quan Gong, Xu-Dong Xiang, Gang Guo, Jia Liu, Li Zhao, Jun Li, Nan Chen, Heng Li, Li-Juan Zhang, Chun-Yan Zhou, Zhi-Yong Wang, Li Zhuang.

   BACKGROUND: Accumulating data indicate that N6-methyladenosine (m6A) RNA methylation and lncRNA deregulation act crucial roles in cancer progression. Heterogeneous nuclear ribonucleoprotein A2B1 (HNRNPA2B1) as an m6A "reader" has been reported to be an oncogene in multiple malignancies. We herein aimed to elucidate the role and underlying mechanism by which HNRNPA2B1-mediated m6A modification of lncRNAs contributes to non-small cell lung cancer (NSCLC).
METHODS: The expression levels of HNRNPA2B1 and their association with the clinicopathological characteristics and prognosis in NSCLC were determined by RT-qPCR, Western blot, immunohistochemistry and TCGA dataset. Then, the role of HNRNPA2B1 in NSCLC cells was assessed by in vitro functional experiments and in vivo tumorigenesis and lung metastasis models. HNRNPA2B1-mediated m6A modification of lncRNAs was screened by m6A-lncRNA epi-transcriptomic microarray and verified by methylated RNA immunoprecipitation (Me-RIP). The lncRNA MEG3-specific binding with miR-21-5p was evaluated by luciferase gene report and RIP assays. The effects of HNRNPA2B1 and (or) lncRNA MEG3 on miR-21-5p/PTEN/PI3K/AKT signaling were examined by RT-qPCR and Western blot analyses.
RESULTS: We found that upregulation of HNRNPA2B1 was associated with distant metastasis and poor survival, representing an independent prognostic factor in patients with NSCLC. Knockdown of HNRNPA2B1 impaired cell proliferation and metastasis in vitro and in vivo, whereas ectopic expression of HNRNPA2B1 possessed the opposite effects. Mechanical investigations revealed that lncRNA MEG3 was an m6A target of HNRNPA2B1 and inhibition of HNRNPA2B1 decreased MEG3 m6A levels but increased its mRNA levels. Furthermore, lncRNA MEG3 could act as a sponge of miR-21-5p to upregulate PTEN and inactivate PI3K/AKT signaling, leading to the suppression of cell proliferation and invasion. Low expression of lncRNA MEG3 or elevated expression of miR-21-5p indicated poor survival in patients with NSCLC.
CONCLUSIONS: Our findings uncover that HNRNPA2B1-mediated m6A modification of lncRNA MEG3 promotes tumorigenesis and metastasis of NSCLC cells by regulating miR-21-5p/PTEN axis and may provide a therapeutic target for NSCLC.

Keywords:  HNRNPA2B1; NSCLC; Proliferation; lncRNA MEG3; m6A; miR-21-5p

DOI:  https://doi.org/10.1186/s12967-023-04190-8
Stem Cells Int. 2023 ;2023 8992284

METTL3 Promotes Osteo/Odontogenic Differentiation of Stem Cells by Inhibiting miR-196b-5p Maturation.

Xiao Han, Guoyue Li, Haoqing Yang, Chen Zhang, Yangyang Cao, Ning Wang, Lihua Ge, Zhipeng Fan.

Mesenchymal stem cells (MSCs) have been considered a potential method for the regeneration of tooth and maxillofacial bone defects based on the multidirectional differentiation characteristics of MSCs. miRNAs have been found to play a key role in the differentiation of MSCs. However, its effectiveness still needs to be improved, and its internal mechanism is still unclear. In the present study, our data discovered that the knockdown of miR-196b-5p promoted alkaline phosphatase (ALP) activity assay, mineralization in vitro, and expressions of osteo/odontogenic differentiation markers DSPP and OCN and enhanced in vivo osteo/odontogenic differentiation of stem cells of the apical papilla (SCAPs). Mechanistically, the results indicated that METTL3-dependent N6-methyladenosine (m6A) methylation inhibited miR-196b-5p maturation by the microprocessor protein DGCR8. Moreover, miR-196b-5p indirectly negatively regulates METTL3 in SCAPs. Then, METTL3 was found to strengthen the ALP activity assay, mineralization, and expressions of osteo/dentinogenic differentiation markers. Taken together, our findings highlight the critical roles of the METTL3-miR-196b-5p signaling axis in an m6A-dependent manner in osteo/odontogenic differentiation of SCAPs, identifying some potential targets for tooth and maxillofacial bone defects.

DOI: https://doi.org/10.1155/2023/8992284
Sci Total Environ. 2023 Jun 08. pii: S0048-9697(23)03369-7. [Epub ahead of print] 164746

As3MT via consuming SAM is involved in arsenic-induced nonalcoholic fatty liver disease by blocking m6A-mediated miR-142-5p maturation.

Han Li, Lu Wu, Fuping Ye, Dapeng Wang, Li Wang, Wenqi Li, Yuan Xu, Zhenyang Li, Jingshu Zhang, Suhua Wang, Aihua Zhang, Qizhan Liu.

  Arsenic, a common environmental hazard, is a risk factor for nonalcoholic fatty liver disease (NAFLD). However, the mechanism remains unclear. Here, we found that chronic exposure to environmental-related doses of arsenic disturbed fatty acid and methionine metabolism in mice, caused liver steatosis, increased arsenic (3) methyltransferase (As3MT), sterol regulatory element binding protein 1 (SREBP1) and lipogenic gene levels, and decreased N6-methyladenosine (m6A) and S-adenosylmethionine (SAM) levels. Mechanistically, arsenic blocks m6A-mediated miR-142-5p maturation by consuming SAM via As3MT. miR-142-5p was involved in arsenic-induced cellular lipid accumulation by targeting SREBP1. SAM supplementation or As3MT deficiency blocked arsenic-induced lipid accumulation by promoting the maturation of miR-142-5p. Moreover, in mice, folic acid (FA) and vitamin B12 (VB12) supplementation blocked arsenic-induced lipid accumulation by restoring SAM levels. Arsenic-exposed heterozygous As3MT mice showed low liver lipid accumulation. Our study demonstrates that SAM consumption caused by arsenic, through As3MT, blocks m6A-mediated miR-142-5p maturation, thereby elevating the levels of SREBP1 and lipogenic genes, leading to NAFLD, which provides a new mechanism and biological insights into the therapy of NAFLD induced by environmental factors.

Keywords:  Arsenic; Arsenic (3) methyltransferase; Nonalcoholic fatty liver disease; m(6)A modification; miR-142-5p

DOI:  https://doi.org/10.1016/j.scitotenv.2023.164746
Discov Oncol. 2023 Jun 14. 14(1): 99

M1A and m7G modification-related genes are potential biomarkers for survival prognosis and for deciphering the tumor immune microenvironment in esophageal squamous cell carcinoma.

Ruixi Wang, Xingyuan Cheng, Dongmei Chi, Shiliang Liu, Qiaoqiao Li, Baoqing Chen, Mian Xi.

   BACKGROUND: Esophageal squamous cell carcinoma (ESCC) is the most common esophageal malignancy, and RNA methylation has been reported to be involved in the tumorigenesis of ESCC. However, no study has explored methylation modifications in m1A and m7G as prognostic markers for survival prediction in ESCC.
METHODS: Public gene-expression data and clinical annotation of 254 patients obtained from The Cancer Genome Atlas and the Gene Expression Omnibus databases were analyzed to identify potential consensus clusters of m1A and m7G modification-related genes. The RNA-seq of 20 patients in Sun Yat-Sen University Cancer Center was used as the validation set. Following screening for relevant differentially expressed genes (DEGs) and enrichment pathways were elucidated. DEGs were used to construct risk models using the randomForest algorithm, and the prognostic role of the models was assessed by applying Kaplan-Meier analysis. Extent of immune cell infiltration, drug resistance, and response to cancer treatment among different clusters and risk groups were also evaluated.
RESULTS: Consensus clustering analysis based on m1A and m7G modification patterns revealed three potential clusters. In total, 212 RNA methylation-related DEGs were identified. The methylation-associated signature consisting of 6 genes was then constructed to calculate methylation-related score (MRScore) and patients were dived into MRScore-high and MRScore-low groups. This signature has satisfied prognostic value for survival of ESCC (AUC = 0.66, 0.67, 0.64 for 2-, 3-, 4- year OS), and has satisfied performance in the validation SYSUCC cohort (AUC = 0.66 for 2- and 3-year OS). Significant correlation between m1A and m7G modification-related genes and immune cell infiltration, and drug resistance was also observed.
CONCLUSIONS: Transcriptomic prognostic signatures based on m1A and m7G modification-related genes are closely associated with immune cell infiltration in ESCC patients and have important correlations with the therapeutic sensitivity of multiple chemotherapeutic agents.

Keywords:  Esophageal squamous cell carcinoma; Immune cell infiltration; Methyladenosine; Prognostic biomarker; Treatment response

DOI:  https://doi.org/10.1007/s12672-023-00710-6
J Mol Cell Cardiol. 2023 Jun 12. pii: S0022-2828(23)00102-5. [Epub ahead of print]181 57-66

Ythdf2 regulates cardiac remodeling through its mRNA target transcripts.

V Kmietczyk, J Oelschläger, P Gupta, E Varma, S Hartl, J Furkel, M Konstandin, A Marx, Z Loewenthal, V Kamuf-Schenk, L Jürgensen, C Stroh, A Gorska, A Martin-Garrido, J Heineke, T Jakobi, N Frey, M Völkers.

  m6A mRNA methylation controls cardiomyocyte function and increased overall m6A levels are a stereotyping finding in heart failure independent of the underlying etiology. However, it is largely unknown how the information is read by m6A reader proteins in heart failure. Here we show that the m6A reader protein Ythdf2 controls cardiac function and identified a novel mechanism how reader proteins control gene expression and cardiac function. Deletion of Ythdf2 in cardiomyocytes in vivo leads to mild cardiac hypertrophy, reduced heart function, and increased fibrosis during pressure overload as well as during aging. Similarly, in vitro the knockdown of Ythdf2 results in cardiomyocyte growth and remodeling. Mechanistically, we identified the eucaryotic elongation factor 2 as post-transcriptionally regulated by Ythdf2 using cell type specific Ribo-seq data. Our study expands our understanding on the regulatory functions of m6A methylation in cardiomyocytes and how cardiac function is controlled by the m6A reader protein Ythdf2.

Keywords:  Eef2; Heart failure; Translation; Ythdf2; m(6)A

DOI:  https://doi.org/10.1016/j.yjmcc.2023.06.001
Metabolism. 2023 Jun 12. pii: S0026-0495(23)00232-9. [Epub ahead of print] 155628

OCTN2 enhances PGC-1α-mediated fatty acid oxidation and OXPHOS to support stemness in hepatocellular carcinoma.

Tao Yang, Ning Liang, Jiahao Zhang, Yaxing Bai, Yuedan Li, Zifeng Zhao, Liusheng Chen, Min Yang, Qian Huang, Pan Hu, Qian Wang, Hongxin Zhang.

   BACKGROUND: The Metabolic reprogramming of tumor cells plays a vital role in the progression of hepatocellular carcinoma. Organic cation/carnitine transporter 2 (OCTN2), a sodium-ion dependent carnitine transporter and a sodium-ion independent tetraethylammonium (TEA) transporter, has been reported to contribute tumor malignancies and metabolic dysregulation in renal and esophageal carcinoma. However, the role of lipid metabolism deregulation mediated by OCTN2 in HCC cells has not been clarified.
METHODS: Bioinformatics analyses and immunohistochemistry assay were employed to identify OCTN2 expression in HCC tissues. The correlation between OCTN2 expression and prognosis was elucidated through K-M survival analysis. The expression and function of OCTN2 were examined via the assays of western blotting, sphere formation, cell proliferation, migration and invasion. The mechanism of OCTN2-mediated HCC malignancies was investigated through RNA-seq and metabolomic analyses. Furthermore, xenograft tumor models based on HCC cells with different OCTN2 expression levels were conducted to analyze the tumorigenic and targetable role of OCTN2 in vivo.
RESULTS: We found that gradually focused OCTN2 was significantly upregulated in HCC and tightly associated with poor prognosis. Additionally, OCTN2 upregulation promoted HCC cells proliferation and migration in vitro and augmented the growth and metastasis of HCC. Moreover, OCTN2 promoted the cancer stem-like properties of HCC by increasing fatty acid oxidation and oxidative phosphorylation. Mechanistically, PGC-1α signaling participated in the HCC cancer stem-like properties mediated by OCTN2 overexpression, which is confirmed by in vitro and in vivo analyses. Furthermore, OCTN2 upregulation may be transcriptionally activated by YY1 in HCC. Particularly, treatment with mildronate, an inhibitor of OCTN2, showed a therapeutic influence on HCC in vitro and in vivo.
CONCLUSIONS: Our findings demonstrate that OCTN2 plays a critical metabolic role in HCC cancer stemness maintenance and HCC progression, providing evidence for OCTN2 as a promising target for HCC therapy.

Keywords:  Cancer stemness; HCC; Lipid metabolism; Mildronate; OCTN2; PGC-1α

DOI:  https://doi.org/10.1016/j.metabol.2023.155628
Cancers (Basel). 2023 Jun 04. pii: 3053. [Epub ahead of print]15(11):

The Emerging, Multifaceted Role of WTAP in Cancer and Cancer Therapeutics.

Guomin Ju, Jiangchu Lei, Shuqi Cai, Siyuan Liu, Xinjia Yin, Chuanhui Peng.

  Cancer is a grave and persistent illness, with the rates of both its occurrence and death toll increasing at an alarming pace. N6-methyladenosine (m6A), the most prevalent mRNA modification in eukaryotic organisms, is catalyzed by methyltransferases and has a significant impact on various aspects of cancer progression. WT1-associated protein (WTAP) is a crucial component of the m6A methyltransferase complex, catalyzing m6A methylation on RNA. It has been demonstrated to participate in numerous cellular pathophysiological processes, including X chromosome inactivation, cell proliferation, cell cycle regulation, and alternative splicing. A better understanding of the role of WTAP in cancer may render it a reliable factor for early diagnosis and prognosis, as well as a key therapeutic target for cancer treatment. It has been found that WTAP is closely related to tumor cell cycle regulation, metabolic regulation, autophagy, tumor immunity, ferroptosis, epithelial mesenchymal transformation (EMT), and drug resistance. In this review, we will focus on the latest advances in the biological functions of WTAP in cancer, and explore the prospects of its application in clinical diagnosis and therapy.

Keywords:  WTAP; cancer; m6A; methylation

DOI:  https://doi.org/10.3390/cancers15113053
J Neurochem. 2023 Jun 09.

Astragaloside IV alleviates neuronal ferroptosis in ischemic stroke by regulating fat mass and obesity-associated-N6-methyladenosine-acyl-CoA synthetase long-chain family member 4 axis.

Zhenglong Jin, Wenying Gao, Fu Guo, Shaojun Liao, Mingzhe Hu, Tao Yu, Shangzhen Yu, Qing Shi.

  Ischemic stroke (IS) is a detrimental neurological disease with limited treatment options. Astragaloside IV (As-IV) was a promising bioactive constituent in the treatment of IS. However, the functional mechanism remains unclear. Here, IS cell and mouse models were established by oxygen glucose deprivation/re-oxygenation (OGD/R) and middle cerebral artery occlusion (MCAO). Quantitative reverse transcription PCR (RT-qPCR), Western blotting, or Immunofluorescence staining measured related gene and protein expression of cells or mice brain tissues, and the results revealed altered expression of acyl-CoA synthetase long-chain family member 4 (Acsl4), fat mass and obesity-associated (Fto), and activation transcription factor 3 (Atf3) after treatment with As-IV. Then, increased N6 -methyladenosine (m6 A) levels caused OGD/R or MCAO were reduced by As-IV according to the data from methylated RNA immunoprecipitation (MeRIP)-qPCR and dot blot assays. Moreover, through a series of functional experiments such as observing mitochondrial changes under transmission electron microscopy (TEM), evaluating cell viability by cell counting kit-8 (CCK-8), analyzing infract area of brain tissues by 2,3,5-triphenyltetrazolium chloride (TTC) staining, measuring levels of malondialdehyde (MDA), lactate dehydrogenase (LDH), Fe2+ , solute carrier family 7 member 11 (Slc7a11) and glutathione peroxidase 4 (Gpx4) and concentration of glutathione (GSH), we found that Fto knockdown, Acsl4 overexpression or Atf3 knockdown promoted the viability of OGD/R cells, inhibited cell ferroptosis, reduced infract size, while As-IV treatment or Fto overexpression reversed these changes. In mechanism, the interplays of YTH N6 -methyladenosine RNA-binding protein 3 (Ythdf3)/Acsl4 and Atf3/Fto were analyzed by RNA-pull down, RNA immunoprecipitation (RIP), chromatin immunoprecipitation (ChIP) and dual-luciferase reporter assay. Fto regulated the m6 A levels of Acsl4. Ythdf3 bound to Acsl4, and modulated its levels through m6 A modification. Atf3 bound to Fto and positively regulated its levels. Overall, As-IV promoted the transcription of Fto by upregulating Atf3, resulting in decreased m6 A levels of Acsl4, thus, improving neuronal injury in IS by inhibiting ferroptosis.

Keywords:  Acsl4; Astragaloside IV; Atf3; Fto; ferroptosis

DOI:  https://doi.org/10.1111/jnc.15871
Front Immunol. 2023 ;14 1207371

Vital roles of m5C RNA modification in cancer and immune cell biology.

Xinyu Gu, Xiao Ma, Chao Chen, Jun Guan, Jing Wang, Shanshan Wu, Haihong Zhu.

  RNA modification plays an important role in epigenetics at the posttranscriptional level, and 5-methylcytosine (m5C) has attracted increasing attention in recent years due to the improvement in RNA m5C site detection methods. By influencing transcription, transportation and translation, m5C modification of mRNA, tRNA, rRNA, lncRNA and other RNAs has been proven to affect gene expression and metabolism and is associated with a wide range of diseases, including malignant cancers. RNA m5C modifications also substantially impact the tumor microenvironment (TME) by targeting different groups of immune cells, including B cells, T cells, macrophages, granulocytes, NK cells, dendritic cells and mast cells. Alterations in immune cell expression, infiltration and activation are highly linked to tumor malignancy and patient prognosis. This review provides a novel and holistic examination of m5C-mediated cancer development by examining the exact mechanisms underlying the oncogenicity of m5C RNA modification and summarizing the biological effects of m5C RNA modification on tumor cells as well as immune cells. Understanding methylation-related tumorigenesis can provide useful insights for the diagnosis as well as the treatment of cancer.

Keywords:  RNA modification; cancer; cancer immunity; immune cells; m5C

DOI:  https://doi.org/10.3389/fimmu.2023.1207371
Epigenetics Chromatin. 2023 Jun 15. 16(1): 26

PARP-dependent and NAT10-independent acetylation of N4-cytidine in RNA appears in UV-damaged chromatin.

Alena Svobodová Kovaříková, Lenka Stixová, Aleš Kovařík, Eva Bártová.

  RNA modifications have been known for many years, but their function has not been fully elucidated yet. For instance, the regulatory role of acetylation on N4-cytidine (ac4C) in RNA can be explored not only in terms of RNA stability and mRNA translation but also in DNA repair. Here, we observe a high level of ac4C RNA at DNA lesions in interphase cells and irradiated cells in telophase. Ac4C RNA appears in the damaged genome from 2 to 45 min after microirradiation. However, RNA cytidine acetyltransferase NAT10 did not accumulate to damaged sites, and NAT10 depletion did not affect the pronounced recruitment of ac4C RNA to DNA lesions. This process was not dependent on the G1, S, and G2 cell cycle phases. In addition, we observed that the PARP inhibitor, olaparib, prevents the recruitment of ac4C RNA to damaged chromatin. Our data imply that the acetylation of N4-cytidine, especially in small RNAs, has an important role in mediating DNA damage repair. Ac4C RNA likely causes de-condensation of chromatin in the vicinity of DNA lesions, making it accessible for other DNA repair factors involved in the DNA damage response. Alternatively, RNA modifications, including ac4C, could be direct markers of damaged RNAs.

Keywords:  DNA repair; NAT10; PARP; RNA acetylation; RNA methylation

DOI:  https://doi.org/10.1186/s13072-023-00501-x
World J Surg Oncol. 2023 Jun 14. 21(1): 180

5-Methylcytosine-related lncRNAs: predicting prognosis and identifying hot and cold tumor subtypes in head and neck squamous cell carcinoma.

Juntao Huang, Ziqian Xu, Chongchang Zhou, Lixin Cheng, Hong Zeng, Yi Shen.

   BACKGROUND: 5-Methylcytosine (m5C) methylation is recognized as an mRNA modification that participates in biological progression by regulating related lncRNAs. In this research, we explored the relationship between m5C-related lncRNAs (mrlncRNAs) and head and neck squamous cell carcinoma (HNSCC) to establish a predictive model.
METHODS: RNA sequencing and related information were obtained from the TCGA database, and patients were divided into two sets to establish and verify the risk model while identifying prognostic mrlncRNAs. Areas under the ROC curves were assessed to evaluate the predictive effectiveness, and a predictive nomogram was constructed for further prediction. Subsequently, the tumor mutation burden (TMB), stemness, functional enrichment analysis, tumor microenvironment, and immunotherapeutic and chemotherapeutic responses were also assessed based on this novel risk model. Moreover, patients were regrouped into subtypes according to the expression of model mrlncRNAs.
RESULTS: Assessed by the predictive risk model, patients were distinguished into the low-MLRS and high-MLRS groups, showing satisfactory predictive effects with AUCs of 0.673, 0.712, and 0.681 for the ROCs, respectively. Patients in the low-MLRS groups exhibited better survival status, lower mutated frequency, and lower stemness but were more sensitive to immunotherapeutic response, whereas the high-MLRS group appeared to have higher sensitivity to chemotherapy. Subsequently, patients were regrouped into two clusters: cluster 1 displayed immunosuppressive status, but cluster 2 behaved as a hot tumor with a better immunotherapeutic response.
CONCLUSIONS: Referring to the above results, we established a m5C-related lncRNA model to evaluate the prognosis, TME, TMB, and clinical treatments for HNSCC patients. This novel assessment system is able to precisely predict the patients' prognosis and identify hot and cold tumor subtypes clearly for HNSCC patients, providing ideas for clinical treatment.

Keywords:  5-Methylcytosine methylation; Head and neck squamous cell carcinoma; Immunotherapy; Long non-coding RNA; Prognosis

DOI:  https://doi.org/10.1186/s12957-023-03067-w
J Hazard Mater. 2023 Jun 12. pii: S0304-3894(23)01114-7. [Epub ahead of print]457 131831

Mechanistic exploration on neurodevelopmental toxicity induced by upregulation of alkbh5 targeted by triclosan exposure to larval zebrafish.

Weiwei Wang, Xin Li, Qiuhui Qian, Jin Yan, Haishan Huang, Xuedong Wang, Huili Wang.

  Because triclosan (TCS) has been confirmed to cause severe neurotoxicity, it is urgent to disclose the underlying toxicity mechanisms at varying levels. TCS exposure resulted in a series of malformations in larval zebrafish, including reduced neurons, blood-vessel ablation and abnormal neurobehavior. Apoptosis staining and the upregulated expression of proapoptotic genes demonstrated that TCS induced neuronal apoptosis and neurotransmitter disorders. By integrating RT-qPCR analysis with the effects of pathway inhibitors and agonists, we found that TCS triggered abnormal regulation of neuron development-related functional genes, and suppressed the BDNF/TrkB signaling pathway. TCS inhibited total m6A-RNA modification level by activating the demethylase ALKBH5, and induced neurodevelopmental toxicity based on the knockdown experiments of alkbh5 and molecular docking. The main novelties of this study lies in: (1) based on specific staining and transgenic lines, the differential neurotoxicity effects of TCS were unravelled at individual, physiological, biochemical and molecular levels in vivo; (2) from a epigenetics viewpoint, the decreasing m6A methylation level was confirmed to be mediated by alkbh5 upregulation; and (3) both homology modeling and molecular docking evidenced the targeting action of TCS on ALKBH5 enzyme. These findings open a novel avene for TCS's risk assessment and early intervention of the contaminant-sourcing diseases.

Keywords:  M(6)A RNA methylation; Triclosan; TrkB receptor; Zebrafish larvae; alkbh5

DOI:  https://doi.org/10.1016/j.jhazmat.2023.131831
Cancer Sci. 2023 Jun 14.

Splicing factor TRA2A contributes to esophageal cancer progression via a noncanonical role in lncRNA m6 A methylation.

Mingrong Bei, Shijia Hao, Kai Lin, Qiuyang Chen, Yujie Cai, Xing Zhao, Leiming Jiang, Lirui Lin, Geng Dong, Jianzhen Xu.

  Transformer 2 alpha homolog (TRA2A), a member of the serine/arginine-rich splicing factor family, has been shown to control mRNA splicing in development and cancers. However, it remains unclear whether TRA2A is involved in lncRNA regulation. In the present study, we found that TRA2A was upregulated and correlated with poor prognosis in esophageal cancer. Downregulation of TRA2A suppressed the tumor growth in xenograft nude mice. Epitranscriptomic microarray showed that depletion of TRA2A affected global lncRNA methylation similarly to the key m6 A methyltransferase, METTL3, by silencing. MeRIP-qPCR, RNA pull-down, CLIP analyses, and stability assays indicated that ablation of TRA2A reduced m6 A-modification of the oncogenic lncRNA MALAT1, thus inducing structural alterations and reduced stability. Furthermore, Co-IP experiments showed TRA2A directly interacted with METTL3 and RBMX, which also affected the writer KIAA1429 expression. Knockdown of TRA2A inhibited cell proliferation in a manner restored by RBMX/KIAA1429 overexpression. Clinically, MALAT1, RBMX, and KIAA1429 were prognostic factors of worse survival in ESCA patients. Structural similarity-based virtual screening in FDA-approved drugs repurposed nebivolol, a β1 -adrenergic receptor antagonist, as a potent compound to suppress the proliferation of esophageal cancer cells. Cellular thermal shift and RIP assay indicated that nebivolol may compete with MALAT1 to bind TRA2A. In conclusion, our study revealed the noncanonical function of TRA2A, which coordinates with multiple methylation proteins to promote oncogenic MALAT1 during ESCA carcinogenesis.

Keywords:  LncRNA methylation; MALAT1; TRA2A; esophageal cancer; splicing factor

DOI:  https://doi.org/10.1111/cas.15870
Oncol Res. 2022 ;30(2): 77-87

IGF2BP3-induced activation of EIF5B contributes to progression of hepatocellular carcinoma cells.

Xiaoyin Li, Qian Wang, Hongfeng Liang, Shisheng Chen, Haiwen Chen, Yaoyong Lu, Changfu Yang.

  In this study, we investigated the functional role of eukaryotic initiation factor 5B (EIF5B) in hepatocellular carcinoma (HCC) and the underlying mechanisms. Bioinformatics analysis demonstrated that the EIF5B transcript and protein levels as well as the EIF5Bcopy number were significantly higher in the HCC tissues compared with the non-cancerous liver tissues. Down-regulation of EIF5B significantly decreased proliferation and invasiveness of the HCC cells. Furthermore, EIF5B knockdown suppressed epithelial-mesenchymal transition (EMT) and the cancer stem cell (CSC) phenotype. Down-regulation of EIF5B also increased the sensitivity of HCC cells to 5-fluorouracil (5-FU). In the HCC cells, activation of the NF-kappa B signaling pathway and IkB phosphorylation was significantly reduced by EIF5B silencing. IGF2BP3 increased the stability of the EIF5B mRNA in an m6A-dependent manner. Our data suggested that EIF5B is a promising prognostic biomarker and therapeutic target in HCC.

Keywords:  Cancer stem cells; EIF5B; Epithelial-mesenchymal transition; Hepatocellular carcinoma; N6-methyladenosine; NF-κB

DOI:  https://doi.org/10.32604/or.2022.026511
Biochim Biophys Acta Mol Cell Res. 2023 Jun 10. pii: S0167-4889(23)00093-9. [Epub ahead of print] 119521

NAT10 regulates the LPS-induced inflammatory response via the NOX2-ROS-NF-κB pathway in macrophages.

Zhanqi Zhang, Yiwen Zhang, Yongjie Cai, Di Li, Jinlin He, Zhihui Feng, Qiong Xu.

  Periodontitis is a chronic osteolytic inflammatory disease resulting from complex dynamic interactions among bacterial pathogens and the host immune response. Macrophages play a vital role in the pathogenesis of periodontitis by triggering periodontal inflammation and inducing periodontium destruction. N-Acetyltransferase 10 (NAT10) is an acetyltransferase that has been shown to catalyse N4-acetylcytidine (ac4C) mRNA modification and is related to cellular pathophysiological processes, including the inflammatory immune response. Nevertheless, whether NAT10 regulates the inflammatory response of macrophages in periodontitis remains unclear. In this study, the expression of NAT10 in macrophages was found to decrease during LPS-induced inflammation. NAT10 knockdown significantly reduced the generation of inflammatory factors, while NAT10 overexpression had the opposite effect. RNA sequencing revealed that the differentially expressed genes were enriched in the NF-κB signalling pathway and oxidative stress. Both the NF-κB inhibitor Bay11-7082 and the ROS scavenger N-acetyl-L-cysteine (NAC) could reverse the upregulation of inflammatory factors. NAC inhibited the phosphorylation of NF-κB, but Bay11-7082 had no effect on the production of ROS in NAT10-overexpressing cells, suggesting that NAT10 activated the LPS-induced NF-κB signalling pathway by regulating ROS generation. Furthermore, the expression and stability of Nox2 was promoted after NAT10 overexpression, indicating that Nox2 may be a potential target of NAT10. In vivo, the NAT10 inhibitor Remodelin reduced macrophage infiltration and bone resorption in ligature-induced periodontitis mice. In summary, these results showed that NAT10 accelerated LPS-induced inflammation via the NOX2-ROS-NF-κB pathway in macrophages and that its inhibitor Remodelin might be of potential therapeutic significance in periodontitis treatment.

Keywords:  Inflammation; Macrophage; NAT10; NF-κB; Oxidative stress; ac(4)C

DOI:  https://doi.org/10.1016/j.bbamcr.2023.119521