NAT10 accelerates pulmonary fibrosis through N4-acetylated TGFB1-initiated epithelial-to-mesenchymal transition upon ambient fine particulate matter exposure

Advances of NAT10 in diseases: insights from dual properties as protein and RNA acetyltransferase

N-acetyltransferase 10 (NAT10) is a member of the Gcn5-related N-acetyltransferase (GNAT) family and it plays a crucial role in various cellular processes, such as regulation of cell mitosis, post-DNA damage response, autophagy and apoptosis regulation, ribosome biogenesis, RNA modification, and other related pathways through its intrinsic protein acetyltransferase and RNA acetyltransferase activities. Moreover, NAT10 is closely associated with the pathogenesis of tumors, Hutchinson-Gilford progeria syndrome (HGPS), systemic lupus erythematosus, pulmonary fibrosis, depression and host-pathogen interactions. In recent years, mRNA acetylation has emerged as a prominent focus of research due to its pivotal role in regulating RNA stability and translation. NAT10 stands out as the sole identified modification enzyme responsible for RNA acetylation. There remains some ambiguity regarding the similarities and differences in NAT10's actions on protein and RNA substrates. While NAT10 involves acetylation modification in both cases, which is a crucial molecular mechanism in epigenetic regulation, there are significant disparities in the catalytic mechanisms, regulatory pathways, and biological processes involved. Therefore, this review aims to offer a comprehensive overview of NAT10 as a protein and RNA acetyltransferase, covering its basic catalytic features, biological functions, and roles in related diseases.

Compression force promotes the osteogenic differentiation of periodontal ligament stem cells by regulating NAT10-mediated ac4C modification of BMP2

BACKGROUND

Orthodontic treatment applies specific corrective forces to teeth, transmitting stress to periodontal tissue, thereby regulating the growth and development of periodontal ligament stem cells (PDLSCs). Recently, N-acetyltransferase 10 (NAT10) mediated N4-acetylcytidine (ac4C) modification is demonstrated to play a key role in the osteogenic differentiation of stem cells. Therefore, this study aimed explore the effects of Orthodontic treatment on the NAT10 mediated ac4C modification and osteogenic differentiation of PDLSCs.

METHODS

Compressive force was used to treat PDLSCs to simulate orthodontic force treatment. The ALP and ARS staining was performed to analyze the osteogenic differentiation of PDLSCs. Besides, ac4C dot blot and ac4C-RIP assays were performed to detect the global ac4C levels and BMP2 ac4C levels. The relationship between NAT10 and BMP2 was confirmed by RIP assay and immunofluorescence staining. The mRNA and protein levels of RUNX2, Oxterix and BMP2 were detected by RT-qPCR and western blot assays.

RESULTS

Compressive force treatment promoted the osteogenic differentiation of PDLSCs, and enhanced the global ac4C levels and NAT10 levels in PDLSCs. NAT10 overexpression further promoted the osteogenic differentiation of compressive force treated PDLSCs. Besides, NAT10 overexpression increased ac4C levels of BMP2 and enhanced the mRNA stability of BMP2. Remodelin treatment significantly decreased the ac4C and mRNA levels of BMP2. Furthermore, BMP2 silencing reversed the role of NAT10 in the compressive force treated PDLSCs.

CONCLUSION

This study demonstrated that compressive force promotes cell viability and osteogenic differentiation of PDLSCs by regulating BMP2 levels mediated by NAT10. NAT10 mediated ac4C levels of BMP2 is the key signaling axis of orthodontic stress in promoting cell growth and osteogenic differentiation of PDLSCs.

Reticulophagy promotes EMT-induced fibrosis in offspring's lung tissue after maternal exposure to carbon black nanoparticles during gestation by a m5C-dependent manner

Accumulating evidence indicates that maternal exposure to carbon black nanoparticles (CBNPs) during gestation can induce multiple system abnormalities in offspring, whereas its potential mechanism in respiratory disease is still largely unknown. In order to explore the effect of maternal exposure to CBNPs on offspring's lung and latent pathogenesis, we respectively established in vivo model of pregnant rats exposed to CBNPs and ex vivo model of lung epithelial cells treated with pups' serum of pregnant rats exposed to CBNPs. After maternal exposure to CBNPs, epithelial-mesenchymal transition (EMT) and fibrosis levels increased as a result of DDRGK1-mediated reticulophagy upregulated in offspring's lung. DDRGK1 as FAM134B's cargo bound with FAM134B to mediate reticulophagy. Transcription factor "SP1" positively regulated DDRGK1 gene expression by binding to its promoter. Furthermore, the upregulation of NSUN2 elevated m5C methylation of SP1 mRNA and the protein level of SP1 subsequently increased through Ybx1 recognizing and stabilizing m5C-methylated SP1 mRNA, followed by the increased levels of reticulophagy and fibrosis in lung epithelial cells treated with offspring's serum of matrix exposed to CBNPs during gestation. In conclusion, NSUN2/Ybx1/m5C-SP1 axis promoted DDRGK1-mediated reticulophagy, which played an important role in EMT-induced fibrosis in offspring's lung tissue after maternal exposure to CBNPs during gestation.

NAT10-mediated RNA ac4C acetylation contributes to the myocardial infarction-induced cardiac fibrosis

Cardiac fibrosis is featured cardiac fibroblast activation and extracellular matrix accumulation. Ac4C acetylation is an important epigenetic regulation of RNAs that has been recently discovered, and it is solely carried out by NAT10, the exclusive enzyme used for the modification. However, the potential regulatory mechanisms of ac4C acetylation in myocardial fibrosis following myocardial infarction remain poorly understood. In our study, we activated fibroblasts in vitro using TGF-β1 (20 ng/mL), followed by establishing a myocardial infarction mouse model to evaluate the impact of NAT10 on collagen synthesis and cardiac fibroblast proliferation. We utilized a NAT10 inhibitor, Remodelin, to attenuate the acetylation capacity of NAT10. In the cardiac fibrosis tissues of chronic myocardial infarction mice and cultured cardiac fibroblasts (CFs) in response to TGF-β1 treatment, there was an elevation in the levels of NAT10 expression. This increase facilitated proliferation, the accumulation of collagens, as well as fibroblast-to-myofibroblast transition. Through the administration of Remodelin, we effectively reduced cardiac fibrosis in myocardial infarction mice by inhibiting NAT10's ability to acetylate mRNA. Inhibition of NAT10 resulted in changes in collagen-related gene expression and ac4C acetylation levels. Mechanistically, we found that NAT10 upregulates the acetylation modification of BCL-XL mRNA and enhances the stability of BCL-XL mRNA, thereby upregulating its protein expression, inhibiting the activation of Caspase3 and blocking the apoptosis of CFs. Therefore, the crucial involvement of NAT10-mediated ac4C acetylation is significant in the cardiac fibrosis progression, affording promising molecular targets for the treatment of fibrosis and relevant cardiac diseases.

Improvement of MASLD and MASH by suppression of hepatic N-acetyltransferase 10

OBJECTIVE

Metabolic dysfunction-associated steatotic liver disease (MASLD) and metabolic dysfunction-associated steatohepatitis (MASH) are characterized by excessive triglyceride accumulation in the liver. However, due to an incomplete understanding of its pathogenesis, more efforts are needed to identify specific and effective treatments. N4-acetylcytidine (ac4C) is a newly discovered RNA modification to regulate mRNA. N-acetyltransferase 10 (NAT10) has not been fully explored in MASLD and MASH.

METHODS

The clinical relevance of NAT10 was evaluated based on its expression in various mouse and human models of MASLD and MASH. Acetylated RNA immunoprecipitation sequencing and mRNA stability assays were used to explore the role of NAT10 in regulating ac4C modification and expression of target genes. Genetically engineered mice were employed to investigate the role of NAT10 in MASLD and MASH progression.

RESULTS

Hepatic NAT10 expression was significantly increased in multiple mice and humans of MASLD and MASH. Genetic knockout of NAT10 protected mice from diet-induced hepatic steatosis and steatohepatitis, whereas overexpression of NAT10 exacerbated high-fat-diet-induced liver steatosis. Mechanistically, NAT10 binds to Srebp-1c mRNA, promoting its stability and expression, thereby upregulating lipogenic enzymes. Treatment with Remodelin, a NAT10-specific inhibitor, effectively ameliorates liver steatosis and dyslipidemia in a preclinical mouse model.

CONCLUSIONS

Our findings indicate that NAT10 could regulate lipid metabolism in MASLD and MASH by stabilizing Srebp-1c mRNA and upregulating lipogenic enzymes. This study highlights the role of NAT10 and RNA acetylation in the pathogenesis of MASLD and MASH. Thus, our findings suggest a promising new therapeutic approach, such as the use of NAT10 inhibitor, for treating metabolic liver disease.

RNA-Seq-Based Transcriptome Analysis of Chinese Cordyceps Aqueous Extracts Protective Effect against Adriamycin-Induced mpc5 Cell Injury

Pharmacogenomic analysis based on drug transcriptome characteristics is widely used to identify mechanisms of action. The purpose of this study was to elucidate the molecular mechanism of protective effect against adriamycin (ADM)-induced mpc5 cell injury of Chinese cordyceps aqueous extracts (WCCs) by a systematic transcriptomic analysis. The phytochemicals of WCCs were analyzed via the "phenol-sulfuric acid method", high-performance liquid chromatography (HPLC), and HPLC-mass spectrometry (MS). We analyzed the drug-reaction transcriptome profiles of mpc5 cell after treating them with WCCs. RNA-seq analysis revealed that WCCs alleviated ADM-induced mpc5 cell injury via restoring the expression of certain genes to normal level mainly in the one-carbon pool by the folate pathway, followed by the relaxin, apelin, PI3K-Akt, and nucleotide-binding, oligomerization domain (NOD)-like receptor signaling pathway, enhancing DNA synthesis and repair, cell proliferation, fibrosis reduction, and immune regulation. Otherwise, WCCs also modulated the proliferation and survival of the mpc5 cell by regulating metabolic pathways, and partially restores the expression of genes related to human disease pathways. These findings provide an innovative understanding of the molecular mechanism of the protective effect of WCCs on ADM-induced mpc5 cell injury at the molecular transcription level, and Mthfd2, Dhfr, Atf4, Creb5, Apln, and Serpine1, etc., may be potential novel targets for treating nephrotic syndrome.

NAT10-mediated ac4C acetylation of TFRC promotes sepsis-induced pulmonary injury through regulating ferroptosis

BACKGROUND

Sepsis-induced pulmonary injury (SPI) is a common complication of sepsis with a high rate of mortality. N4-acetylcytidine (ac4C) is mediated by the ac4C "writer", N-acetyltransferase (NAT)10, to regulate the stabilization of mRNA. This study aimed to investigate the role of NAT10 in SPI and the underlying mechanism.

METHODS

Twenty-three acute respiratory distress syndrome (ARDS) patients and 27 non-ARDS volunteers were recruited. A sepsis rat model was established. Reverse transcription-quantitative polymerase chain reaction was used to detect the expression of NAT10 and transferrin receptor (TFRC). Cell viability was detected by cell counting kit-8. The levels of Fe2+, glutathione, and malondialdehyde were assessed by commercial kits. Lipid reactive oxygen species production was measured by flow cytometric analysis. Western blot was used to detect ferroptosis-related protein levels. Haematoxylin & eosin staining was performed to observe the pulmonary pathological symptoms.

RESULTS

The results showed that NAT10 was increased in ARDS patients and lipopolysaccharide-treated human lung microvascular endothelial cell line-5a (HULEC-5a) cells. NAT10 inhibition increased cell viability and decreased ferroptosis in HULEC-5a cells. TFRC was a downstream regulatory target of NAT10-mediated ac4C acetylation. Overexpression of TFRC decreased cell viability and promoted ferroptosis. In in vivo study, NAT10 inhibition alleviated SPI.

CONCLUSION

NAT10-mediated ac4C acetylation of TFRC aggravated SPI through promoting ferroptosis.

Rosmarinic Acid Alleviates Radiation-Induced Pulmonary Fibrosis by Downregulating the tRNA N7-Methylguanosine Modification-Regulated Fibroblast-to-Myofibroblast Transition Through the Exosome Pathway

Background

Radiation-induced pulmonary fibrosis (RIPF) is a common complication after radiotherapy in thoracic cancer patients, and effective treatment methods are lacking. The purpose of this study was to investigate the protective effect of rosmarinic acid (RA) on RIPF in mice as well as the mechanism involved.

Methods

m7G-tRNA-seq and tRNA-seq analyses were conducted to identify m7G-modified tRNAs. Western blotting, immunohistochemistry, northwestern blotting, northern blotting, immunofluorescence, wound-healing assays and EdU experiments were performed to explore the molecular mechanism by which RA regulates fibroblast-to-myofibroblast transformation (FMT) by affecting the exosomes of lung epithelial cells. Ribo-seq and mRNA-seq analyses were used to explore the underlying target mRNAs. Seahorse assays and immunoprecipitation were carried out to elucidate the effects of RA on glycolysis and FMT processes via the regulation of 6-phosphofructo-2-kinase/fructose-2,6-biphosphatase 3 (PFKFB3) acetylation.

Results

We found that RA had an antifibrotic effect on the lung tissues of RIPF model mice and inhibited the progression of FMT through exosomes derived from lung epithelial cells. Mechanistically, RA reduced the transcription and translation efficiency of sphingosine kinase 1 in lung fibroblasts by decreasing N7-methylguanosine modification of tRNA, downregulating the expression of tRNAs in irradiated lung epithelial cell-derived exosomes, and inhibiting the interaction between sphingosine kinase 1 and the N-acetyltransferase 10 protein in fibroblasts. Furthermore, the acetylation and cytoplasmic translocation of PFKFB3 were reduced by exosomes derived from irradiated lung epithelial cells, which following RA intervention. This suppression of the FMT process, which is triggered by glycolysis, and ultimately decelerating the progression of RIPF.

Conclusion

These findings suggest that RA is a potential therapeutic agent for RIPF.

Exploring the impact of N4-acetylcytidine modification in RNA on non-neoplastic disease: unveiling its role in pathogenesis and therapeutic opportunities

RNA modifications include not only methylation modifications, such as m6A, but also acetylation modifications, which constitute a complex interaction involving "writers," "readers," and "erasers" that play crucial roles in growth, genetics, and disease. N4-acetylcytidine (ac4C) is an ancient and highly conserved RNA modification that plays a profound role in the pathogenesis of a wide range of diseases. This review provides insights into the functional impact of ac4C modifications in disease and introduces new perspectives for disease treatment. These studies provide important insights into the biological functions of post-transcriptional RNA modifications and their potential roles in disease mechanisms, offering new perspectives and strategies for disease treatment.

Epigenetic mechanisms of particulate matter exposure: air pollution and hazards on human health

Environmental pollution nowadays has not only a direct correlation with human health changes but a direct social impact. Epidemiological studies have evidenced the increased damage to human health on a daily basis because of damage to the ecological niche. Rapid urban growth and industrialized societies importantly compromise air quality, which can be assessed by a notable accumulation of air pollutants in both the gas and the particle phases. Of them, particulate matter (PM) represents a highly complex mixture of organic and inorganic compounds of the most variable size, composition, and origin. PM being one of the most complex environmental pollutants, its accumulation also varies in a temporal and spatial manner, which challenges current analytical techniques used to investigate PM interactions. Nevertheless, the characterization of the chemical composition of PM is a reliable indicator of the composition of the atmosphere, the quality of breathed air in urbanized societies, industrial zones and consequently gives support for pertinent measures to avoid serious health damage. Epigenomic damage is one of the most promising biological mechanisms of air pollution-derived carcinogenesis. Therefore, this review aims to highlight the implication of PM exposure in diverse molecular mechanisms driving human diseases by altered epigenetic regulation. The presented findings in the context of pan-organic cancer, fibrosis, neurodegeneration and metabolic diseases may provide valuable insights into the toxicity effects of PM components at the epigenomic level and may serve as biomarkers of early detection for novel targeted therapies.

Acetylation in pathogenesis: Revealing emerging mechanisms and therapeutic prospects

Protein acetylation modifications play a central and pivotal role in a myriad of biological processes, spanning cellular metabolism, proliferation, differentiation, apoptosis, and beyond, by effectively reshaping protein structure and function. The metabolic state of cells is intricately connected to epigenetic modifications, which in turn influence chromatin status and gene expression patterns. Notably, pathological alterations in protein acetylation modifications are frequently observed in diseases such as metabolic syndrome, cardiovascular disorders, and cancer. Such abnormalities can result in altered protein properties and loss of function, which are closely associated with developing and progressing related diseases. In recent years, the advancement of precision medicine has highlighted the potential value of protein acetylation in disease diagnosis, treatment, and prevention. This review includes provocative and thought-provoking papers outlining recent breakthroughs in acetylation modifications as they relate to cardiovascular disease, mitochondrial metabolic regulation, liver health, neurological health, obesity, diabetes, and cancer. Additionally, it covers the molecular mechanisms and research challenges in understanding the role of acetylation in disease regulation. By summarizing novel targets and prognostic markers for the treatment of related diseases, we aim to contribute to the field. Furthermore, we discuss current hot topics in acetylation research related to health regulation, including N4-acetylcytidine and liquid-liquid phase separation. The primary objective of this review is to provide insights into the functional diversity and underlying mechanisms by which acetylation regulates proteins in disease contexts.

Korean Red Ginseng Prevents the Deterioration of Lung and Brain Function in Chronic PM2.5-Exposed Mice by Regulating Systemic Inflammation

This study was conducted to confirm the effects of Korean red ginseng on lung and brain dysfunction in a BALB/c mice model exposed to particulate matter (PM)2.5 for 12 weeks. Learning and cognitive abilities were assessed with Y-maze, passive avoidance, and Morris water maze tests. To evaluate the ameliorating effect of red ginseng extract (RGE), the antioxidant system and mitochondrial function were investigated. The administration of RGE protected lung and brain impairment by regulating the antioxidant system and mitochondrial functions damaged by PM2.5-induced toxicity. Moreover, RGE prevented pulmonary fibrosis by regulating the transforming growth factor beta 1 (TGF-β1) pathway. RGE attenuated PM2.5-induced pulmonary and cognitive dysfunction by regulating systemic inflammation and apoptosis via the nuclear factor kappa-light-chain-enhancer of activated B cells (NF-κB)/c-Jun N-terminal kinases (JNK) pathway. In conclusion, RGE might be a potential material that can regulate chronic PM2.5-induced lung and brain cognitive dysfunction.