METTL14-m6A-FOXO3a axis regulates autophagy and inflammation in ankylosing spondylitis

ETS1 and RBPJ transcriptionally regulate METTL14 to suppress TGF-β1-induced epithelial-mesenchymal transition in human bronchial epithelial cells

Asthma is a chronic respiratory disease characterized by airway inflammation and remodeling. Epithelial-mesenchymal transition (EMT) of bronchial epithelial cells is considered to be a crucial player in asthma. Methyltransferase-like 14 (METTL14), an RNA methyltransferase, is implicated in multiple pathological processes, including EMT, cell proliferation and migration. However, the role of METTL14 in asthma remains uncertain. This research aimed to explore the biological functions of METTL14 in asthma and its underlying upstream mechanisms. METTL14 expression was down-regulated in asthmatic from three GEO datasets (GSE104468, GSE165934, and GSE74986). Consistent with this trend, METTL14 was decreased in the lung tissues of OVA-induced asthmatic mice and transforming growth factor-β1 (TGF-β1)-stimulated human bronchial epithelial cells (Beas-2B) in this study. Overexpression of METTL14 caused reduction in mesenchymal markers (FN1, N-cad, Col-1 and α-SMA) in TGF-β1-treated cells, but caused increase in epithelial markers (E-cad), thus inhibiting EMT. Also, METTL14 suppressed the proliferation and migration ability of TGF-β1-treated Beas-2B cells. Two transcription factors, ETS1 and RBPJ, could both bind to the promoter region of METTL14 and drive its expression. Elevating METTL14 expression could reversed EMT, cell proliferation and migration promoted by ETS1 or RBPJ deficiency. These results indicate that the ETS1/METTL14 and RBPJ/METTL14 transcription axes exhibit anti-EMT, anti-proliferation and anti-migration functions in TGF-β1-induced bronchial epithelial cells, implying that METTL14 may be considered an alternative candidate target for the treatment of asthma.

Application of methylation in the diagnosis of ankylosing spondylitis

Ankylosing spondylitis (AS) is a chronic inflammatory autoimmune disease, mainly characterized by perifibrocartilage osteitis of the sacroiliac joints and spinal enthesitis. To date, the exact pathogenesis of AS remains elusive. It is generally believed that AS is a multifactorial disease involving genetics, infection, environment, and immunity. Among them, genetic factors are the primary determinants of disease risk and severity. In recent years, epigenetic mechanisms such as DNA methylation have been extensively surveyed with respect to the pathogenesis of AS. This review summarizes the latest research progress of methylation in AS, from whole-genome sequencing to individual differentially methylated gene. And finally, the role of methylase in AS inflammation, autophagy, and osteogenic differentiation was explored. In summary, the results of this review attempt to explain the role of methylation in the occurrence and development of AS and point out the shortcomings of current methylation research, providing directions for subsequent methylation research in AS.

Evidence for the potential role of m6A modification in regulating autophagy in models of amyotrophic lateral sclerosis

Objective

Amyotrophic lateral sclerosis (ALS) is a devastating neurodegenerative disease. Research indicates that N6-methyladenosine (m6A) modification plays a crucial role in cellular autophagy during ALS development. This study investigates the role of autophagy in ALS, with a focus on the effect of messenger ribonucleic acid m6A methylation modification on disease progression.

Material and Methods

We compared m6A levels and regulatory molecule expressions in transgenic superoxide dismutase (SOD1)-G93A and non-transgenic mice, categorized into end-stage and control groups, using quantitative polymerase chain reaction and Western blotting. The NSC-34 cell line, which was modified to model ALS, enabled the investigation of apoptosis, autophagy, and autophagy disruption through terminal deoxynucleotidyl transferase deoxyuridine triphosphate nick-end labeling assays, Western blotting, and fluorescent staining.

Results

Our findings indicate significantly elevated m6A methylation levels in ALS mice (0.262 ± 0.005) compared with the controls (0.231 ± 0.003) and in the ALS model cells (0.242±0.005) relative to those belonging to the wild-type control group (0.183 ± 0.007). Furthermore, the proteins involved in m6A RNA modification differed between groups, which suggest impaired autophagy flux in the ALS models.

Conclusion

These results suggest that m6A methylation may accelerate ALS progression through the disruption of autophagic processes. Our study underscores the role of m6A methylation in the pathology of ALS and proposes the targeting of m6A methylation as a potential therapeutic strategy for disease treatment. Although this study primarily used transgenic SOD1-G93A mice and NSC-34 cell models to investigate ALS pathology, potential differences in disease mechanisms between animal models and humans must be considered. Although a correlation was detected between m6A methylation levels and autophagy disruption in ALS, the study primarily established an association rather than provided detailed mechanistic insights.

The physiological and pathological roles of RNA modifications in T cells

RNA molecules undergo dynamic chemical modifications in response to various external or cellular stimuli. Some of those modifications have been demonstrated to post-transcriptionally modulate the RNA transcription, localization, stability, translation, and degradation, ultimately tuning the fate decisions and function of mammalian cells, particularly T cells. As a crucial part of adaptive immunity, T cells play fundamental roles in defending against infections and tumor cells. Recent findings have illuminated the importance of RNA modifications in modulating T cell survival, proliferation, differentiation, and functional activities. Therefore, understanding the epi-transcriptomic control of T cell biology enables a potential avenue for manipulating T cell immunity. This review aims to elucidate the physiological and pathological roles of internal RNA modifications in T cell development, differentiation, and functionality drawn from current literature, with the goal of inspiring new insights for future investigations and providing novel prospects for T cell-based immunotherapy.

Photobiomodulation Using 830 nm Lighting-Emitting Diode Inhibits Melanogenesis via FOXO3a in Human Melanocyte

Photobiomodulation (PBM) using 830 nm light-emitting diode (LED) benefits tissue regeneration, wound healing and neural stimulation. However, there is not much exploration of its effect on melanocytes and ex vivo skin model. This study aims to investigate the mechanism behind the anti-melanogenic activity of 830 nm LED and provides evidence for its activity in human ex vivo skin model. Our results showed that 830 nm LED at fluences ranging from 5 to 20 J/cm2 inhibited melanosome maturation and reduced melanin content, tyrosinase activity and melanogenesis-related proteins. 830 nm LED inhibited the phosphorylation of AKT and its downstream FOXO3a, leading to nuclear translocation of FOXO3a. Furthermore, FOXO3a knockdown and AKT activator like SC79 could reverse the melanogenesis inhibition phenotype induced by 830 nm LED. In human ex vivo skin model, Fontana-Masson staining revealed a decrease in epidermal basal pigmentation after 830 nm LED irradiation. Taken together, 830 nm LED demonstrated the anti-melanogenic activity via FOXO3a.

Identification of key genes with abnormal RNA methylation modification and selected m6A regulators in ankylosing spondylitis

BACKGROUND

N6-methyladenosine (m6A) has been identified as the most abundant modification of RNA molecules and the aberrant m6A modifications have been associated with the development of autoimmune diseases. However, the role of m6A modification in ankylosing spondylitis (AS) has not been adequately investigated. Therefore, we aimed to explore the significance of m6A regulator-mediated RNA methylation in AS.

METHODS

The methylated RNA immunoprecipitation sequencing (meRIP-seq) and digital RNA sequencing (Digital RNA-seq) were conducted using the peripheral blood mononuclear cells from three AS cases and three healthy controls, to identify genes affected by abnormal RNA methylation. The genes associated with different peaks were cross-referenced with AS-related genes obtained from the GeneCards Suite. Subsequently, the expression levels of shared differentially expressed genes (DEGs) and key m6A regulators in AS were evaluated using data from 68 AS cases and 36 healthy controls from two data sets (GSE25101 and GSE73754). In addition, the results were validated through quantitative polymerase chain reaction (qPCR).

RESULTS

The meRIP-seq and Digital RNA-seq analyses identified 28 genes with upregulated m6A peaks but with downregulated expression, and 52 genes with downregulated m6A peaks but with upregulated expression. By intersecting the genes associated with different peaks with 2184 AS-related genes from the GeneCards Suite, we identified a total of five shared DEGs: BCL11B, KAT6B, IL1R1, TRIB1, and ALDH2. Through analysis of the data sets and qPCR, we found that BCL11B and IL1R1 were differentially expressed in AS. Moreover, two key m6A regulators, WTAP and heterogeneous nuclear ribonucleoprotein C, were identified.

CONCLUSIONS

In conclusion, the current study revealed that m6A modification plays a crucial role in AS and might hence provide a new treatment strategy for AS disease.

Exploring the impact of m6A modification on immune diseases: mechanisms and therapeutic implication

N6-methyladenosine (m6A) is a chemical modification of RNA and has become a widely discussed topic among scientific researchers in recent years. It is distributed in various organisms, including eukaryotes and bacteria. It has been found that m6A is composed of writers, erasers and readers and is involved in biological functions such as splicing, transport and translation of RNA. The balance of the human immune microenvironment is important for human health abnormalities. Increasing studies have found that m6A affects the development of immune diseases such as inflammatory enteritis and systemic lupus erythematosus (SLE) by participating in the homeostatic regulation of the immune microenvironment in vivo. In this manuscript, we introduce the composition, biological function, regulation of m6A in the immune microenvironment and its progression in various immune diseases, providing new targets and directions for the treatment of immune diseases in clinical practice.

Identification of sex-specific biomarkers related to programmed cell death and analysis of immune cells in ankylosing spondylitis

Ankylosing spondylitis (AS) stands as a persistent inflammatory ailment predominantly impacting the axial skeleton, with the immune system and inflammation intricately entwined in its pathogenesis. This study endeavors to elucidate gender-specific patterns in immune cell infiltration and diverse forms of cell demise within the AS milieu. The aim is to refine the diagnosis and treatment of gender-specific AS patients, thereby advancing patient outcomes. In the pursuit of our investigation, two datasets (GSE25101 and GSE73754) pertinent to ankylosing spondylitis (AS) were meticulously collected and normalized from the GEO database. Employing the CIBERSORT algorithm, we conducted a comprehensive analysis of immune cell infiltration across distinct demographic groups and genders. Subsequently, we discerned differentially expressed genes (DEGs) associated with various cell death modalities in AS patients and their healthy counterparts. Our focus extended specifically to ferroptosis-related DEGs (FRDEGs), cuproptosis-related DEGs (CRDEGs), anoikis-related DEGs (ARDEGs), autophagy-related DEGs (AURDEGs), and pyroptosis-related DEGs (PRDEGs). Further scrutiny involved discerning disparities in these DEGs between AS patients and healthy controls, as well as disparities between male and female patients. Leveraging machine learning (ML) methodologies, we formulated disease prediction models employing cell death-related DEGs (CDRDEGs) and identified biomarkers intertwined with cell death in AS. Relative to healthy controls, a myriad of differentially expressed genes (DEGs) linked to cell death surfaced in AS patients. Among AS patients, 82 FRDEGs, 29 CRDEGs, 54 AURDEGs, 21 ARDEGs, and 74 PRDEGs were identified. In male AS patients, these numbers were 78, 33, 55, 24, and 94, respectively. Female AS patients exhibited 66, 41, 40, 17, and 82 DEGs in the corresponding categories. Additionally, 36 FRDEGs, 14 CRDEGs, 19 AURDEGs, 10 ARDEGs, and 36 PRDEGs exhibited differential expression between male and female AS patients. Employing machine learning techniques, LASSO, RF, and SVM-RFE were employed to discern key DEGs related to cell death (CDRDDEGs). The six pivotal CDRDDEGs in AS patients, healthy controls, were identified as CLIC4, BIRC2, MATK, PKN2, SLC25A5, and EDEM1. For male AS patients, the three crucial CDRDDEGs were EDEM1, MAP3K11, and TRIM21, whereas for female AS patients, COX7B, PEX2, and RHEB took precedence. Furthermore, the trio of DDX3X, CAPNS1, and TMSB4Y emerged as the key CDRDDEGs distinguishing between male and female AS patients. In the realm of immune correlation, the immune infiltration abundance in female patients mirrored that of healthy controls. Notably, key genes exhibited a positive correlation with T-cell CD4 memory activation when comparing male and female patient samples. This study engenders a more profound comprehension of the molecular underpinnings governing immune cell infiltration and cell death in ankylosing spondylitis (AS). Furthermore, the discernment of gender-specific disparities among AS patients underscores the clinical significance of these findings. By identifying DEGs associated with diverse cell death modalities, this study proffers invaluable insights into potential clinical targets for AS patients, taking cognizance of gender-specific nuances. The identification of gender-specific biological targets lays the groundwork for the development of tailored diagnostic and therapeutic strategies, heralding a pivotal step toward personalized care for AS patients.

Identification of sex-specific biomarkers related to programmed cell death and analysis of immune cells in ankylosing spondylitis

Ankylosing spondylitis (AS) stands as a persistent inflammatory ailment predominantly impacting the axial skeleton, with the immune system and inflammation intricately entwined in its pathogenesis. This study endeavors to elucidate gender-specific patterns in immune cell infiltration and diverse forms of cell demise within the AS milieu. The aim is to refine the diagnosis and treatment of gender-specific AS patients, thereby advancing patient outcomes. In the pursuit of our investigation, two datasets (GSE25101 and GSE73754) pertinent to ankylosing spondylitis (AS) were meticulously collected and normalized from the GEO database. Employing the CIBERSORT algorithm, we conducted a comprehensive analysis of immune cell infiltration across distinct demographic groups and genders. Subsequently, we discerned differentially expressed genes (DEGs) associated with various cell death modalities in AS patients and their healthy counterparts. Our focus extended specifically to ferroptosis-related DEGs (FRDEGs), cuproptosis-related DEGs (CRDEGs), anoikis-related DEGs (ARDEGs), autophagy-related DEGs (AURDEGs), and pyroptosis-related DEGs (PRDEGs). Further scrutiny involved discerning disparities in these DEGs between AS patients and healthy controls, as well as disparities between male and female patients. Leveraging machine learning (ML) methodologies, we formulated disease prediction models employing cell death-related DEGs (CDRDEGs) and identified biomarkers intertwined with cell death in AS. Relative to healthy controls, a myriad of differentially expressed genes (DEGs) linked to cell death surfaced in AS patients. Among AS patients, 82 FRDEGs, 29 CRDEGs, 54 AURDEGs, 21 ARDEGs, and 74 PRDEGs were identified. In male AS patients, these numbers were 78, 33, 55, 24, and 94, respectively. Female AS patients exhibited 66, 41, 40, 17, and 82 DEGs in the corresponding categories. Additionally, 36 FRDEGs, 14 CRDEGs, 19 AURDEGs, 10 ARDEGs, and 36 PRDEGs exhibited differential expression between male and female AS patients. Employing machine learning techniques, LASSO, RF, and SVM-RFE were employed to discern key DEGs related to cell death (CDRDDEGs). The six pivotal CDRDDEGs in AS patients, healthy controls, were identified as CLIC4, BIRC2, MATK, PKN2, SLC25A5, and EDEM1. For male AS patients, the three crucial CDRDDEGs were EDEM1, MAP3K11, and TRIM21, whereas for female AS patients, COX7B, PEX2, and RHEB took precedence. Furthermore, the trio of DDX3X, CAPNS1, and TMSB4Y emerged as the key CDRDDEGs distinguishing between male and female AS patients. In the realm of immune correlation, the immune infiltration abundance in female patients mirrored that of healthy controls. Notably, key genes exhibited a positive correlation with T-cell CD4 memory activation when comparing male and female patient samples. This study engenders a more profound comprehension of the molecular underpinnings governing immune cell infiltration and cell death in ankylosing spondylitis (AS). Furthermore, the discernment of gender-specific disparities among AS patients underscores the clinical significance of these findings. By identifying DEGs associated with diverse cell death modalities, this study proffers invaluable insights into potential clinical targets for AS patients, taking cognizance of gender-specific nuances. The identification of gender-specific biological targets lays the groundwork for the development of tailored diagnostic and therapeutic strategies, heralding a pivotal step toward personalized care for AS patients.

Epigenetic modifications in abdominal aortic aneurysms: from basic to clinical

Abdominal Aortic Aneurysm (AAA) is a disease characterized by localized dilation of the abdominal aorta, involving multiple factors in its occurrence and development, ultimately leading to vessel rupture and severe bleeding. AAA has a high mortality rate, and there is a lack of targeted therapeutic drugs. Epigenetic regulation plays a crucial role in AAA, and the treatment of AAA in the epigenetic field may involve a series of related genes and pathways. Abnormal expression of these genes may be a key factor in the occurrence of the disease and could potentially serve as promising therapeutic targets. Understanding the epigenetic regulation of AAA is of significant importance in revealing the mechanisms underlying the disease and identifying new therapeutic targets. This knowledge can contribute to offering AAA patients better clinical treatment options beyond surgery. This review systematically explores various aspects of epigenetic regulation in AAA, including DNA methylation, histone modification, non-coding RNA, and RNA modification. The analysis of the roles of these regulatory mechanisms, along with the identification of relevant genes and pathways associated with AAA, is discussed comprehensively. Additionally, a comprehensive discussion is provided on existing treatment strategies and prospects for epigenetics-based treatments, offering insights for future clinical interventions.

Methylation of T and B Lymphocytes in Autoimmune Rheumatic Diseases

The role of abnormal epigenetic modifications, particularly DNA methylation, in the pathogenesis of autoimmune rheumatic diseases (ARDs) has garnered increasing attention. Lymphocyte dysfunction is a significant contributor to the pathogenesis of ARDs. Methylation is crucial for maintaining normal immune system function, and aberrant methylation can hinder lymphocyte differentiation, resulting in functional abnormalities that disrupt immune tolerance, leading to the excessive expression of inflammatory cytokines, thereby exacerbating the onset and progression of ARDs. Recent studies suggest that methylation-related factors have the potential to serve as biomarkers for monitoring the activity of ARDs. This review summarizes the current state of research on the impact of DNA and RNA methylation on the development, differentiation, and function of T and B cells and examines the progress of these epigenetic modifications in studies of six specific ARDs: systemic lupus erythematosus, rheumatoid arthritis, Sjögren's syndrome, systemic sclerosis, juvenile idiopathic arthritis, and ankylosing spondylitis. Additionally, we propose that exploring the interplay between RNA methylation and DNA methylation may represent a novel direction for understanding the pathogenesis of ARDs and developing novel treatment strategies.

Analysis of m6A regulators related immune characteristics in ankylosing spondylitis by integrated bioinformatics and computational strategies

N6-methyladenosine (m6A) modification, as a common epigenetic modification, has been widely studied in autoimmune diseases. However, the role of m6A in the regulation of the immune microenvironment of ankylosing spondylitis (AS) remains unclear. Therefore, we aimed to investigate the effect of m6A modification on the immune microenvironment of AS. We first evaluated RNA modification patterns mediated by 26 m6A regulators in 52 AS samples and 20 healthy samples. Thereafter, an m6A related classifier composed of seven genes was constructed and could effectively distinguish healthy and AS samples. Then, the correlation between m6A regulators and immune characteristics were investigated, including infiltrating immunocytes, immune reactions activity, and human leukocyte antigen (HLA) genes expression. The results indicated that m6A regulators was closely correlated with immune characteristics. For example, EIF3A was significantly related to infiltrating immunocytes; IGF2BP2 and EIF3A were significant regulators in immune reaction of TGF-β family member, and the expression of HLA-DPA1 and HLA-E were affected by EIF3A and ALKBH5. Next, two distinct m6A expression patterns were identified through unsupervised clustering analysis, and diverse immune characteristics were found between them. A total of 5889 m6A phenotype-related genes were obtained between the two expression patterns, and their biological functions were revealed. Finally, we validated the expression status of m6A modification regulators using two additional datasets. Our findings illustrate that m6A modifications play a critical role in the diversity and complexity of the AS immune microenvironment.