N6-methyladenosine methylation regulator RBM15 promotes the progression of diabetic nephropathy by regulating cell proliferation, inflammation, oxidative stress, and pyroptosis through activating the AGE-RAGE pathway

Methyltransferase-like 16 drives diabetic nephropathy progression via epigenetic suppression of V-set pre-B cell surrogate light chain 3

AIMS

This study aims to elucidate how Methyltransferase-like 16 (METTL16), as a key m6A methyltransferase, contributes to the pathogenesis of diabetic nephropathy by regulating oxidative stress and gene expression through epigenetic mRNA methylation.

MATERIALS AND METHODS

In the present study, in vivo and in vitro DN models were established to investigate the role of METTL16 in disease progression. RNA-seq and m6A-seq were employed to identify downstream targets of METTL16 and validate its regulatory mechanisms. Intervention experiments were conducted to further elucidate the impact of this axis on DN progression.

KEY FINDINGS

In DN models, METTL16 expression was significantly upregulated, accompanied by an increase in m6A modification levels and enhanced YTH N6-methyladenosine RNA binding protein 2 (YTHDF2)-mediated recognition activity. Transcriptomic analysis identified v-set pre-B cell surrogate light chain (Vpreb3) as a downstream target of METTL16. In the DN model, Vpreb3 expression was suppressed through METTL16-mediated m6A modification and YTHDF2-mediated m6A-dependent mRNA degradation. Silencing METTL16 restored Vpreb3 expression and alleviated oxidative stress-induced kidney injury. The results of the present study indicated that METTL16 epigenetically suppresses Vpreb3 expression, exacerbating the progression of DN.

SIGNIFICANCE

This suggests that targeting this pathway could serve as a potential therapeutic strategy to mitigate oxidative stress and alleviate DN-associated renal injury.

Systematic molecular profiling of non-native N6-substitution effects on m6A binding to the YTH domains of human RNA m6A readers in diabetes

The RNA N6-adenosine methylation, resulting in N6-methyl adenosine (m6A), is one of the most important post-transcriptional modification events in the eukaryotic transcriptome, which is dynamically regulated by methyltransferases (writers), recognition proteins (readers) and demethylases (erasers). Human has five m6A readers namely YTHDC1, YTHDC2, YTHDF1, YTHDF2 and YTHDF3 that specifically recognize and bind to the methylated m6A residue of RNA through their YT521-B homology (YTH) domains, which have been involved in the pathogenesis of diabetes mellitus and its diverse complications such as diabetic nephropathy. Instead of the native N6-methylation, we herein attempted to explore the molecular effect of various non-native N6-substitutions on adenosine (A) binding behavior to YTH domains. A systematic interaction profile of 40 reported N6-substituted adenosine (x6A) mononucleotides with 5 human reader YTH domains was created computationally. Heuristic clustering of the profile divided these YTH domains and these x6A mononucleotides into two subfamilies and three classes, respectively; they represent distinct intrinsic interaction modes between the domains and mononucleotides. Statistical survey unraveled that the volume (Vg) and hydrophobicity (Hg) of N6-substituted chemical groups exhibit linear and nonlinear correlations with the binding energy (ΔGttl) of x6A mononucleotides to YTH domains, respectively; N6-substitutions with moderate size and weak polarity are favorable for the x6A binding. From the profile the N6-bromomethyl adenosine (brm6A) was identified as a potent binder of YTHDF2 YTH domain; its affinity was improved significantly by 77.2-fold from A and considerably by 19.5-fold from m6A. Structural modeling observed that the N6-bromomethyl group of brm6A is tightly packed against an aromatic cage defined by the Trp432-Trp486-Trp491 triad of YTHDF2 YTH domain. Electron-correlation analysis revealed that the bromine atom can form geometrically and energetically satisfactory halogen-π interactions with the aromatic cage, thus conferring considerable affinity and specificity to the domain-brm6A interaction.

Irradiation of 125I seeds blocks glycolysis in pancreatic cancer by inhibiting KLF5 m6A methylation through the suppression of RBM15

This paper investigated whether 125I seed irradiation for pancreatic cancer treatment was mediated through the RBM15/KLF5 pathway in glycolysis. The study collected peripheral blood from pancreatic cancer patients, and detected the expression of RBM15 and KLF5 expression in the serum of pancreatic cancer patients before and after 125I seed irradiation. An in vitro study was conducted to investigate the effects 125I seed irradiation on the malignant behavior and glycolysis of pancreatic cancer cells. The underlying mechanisms were thoroughly examined through a series of logical experiments, including Western blot analysis, Dot-blot experiment, methylated RNA immunoprecipitation assay, and RNA pull down assay. A xenograft tumor model in nude mice was established and treated with 125I seed irradiation, which was employed to research the in vivo effect and mechanism of 125I seed irradiation for pancreatic cancer. The overexpressed RBM15 and KLF5 in serum of pancreatic cancer patients were reduced after 125I seed treatment. 125I seed treatment impaired pancreatic cancer cell proliferation and invasion; enhanced apoptosis; attenuated glycolysis; and reduced RBM15 and KLF5 expression. RBM15 overexpression partially reversed these influences of 125I seed treatment on pancreatic cancer cells. RBM15 was capable of increasing KLF5 expression, which might be achieved by promoting m6A methylation of KLF5. In vivo, 125I seed treatment blocked the growth of pancreatic cancer cells and decreased RBM15 and KLF5 expression in xenograft tumor, whereas RBM15 overexpression abolished these effects. 125I seed irradiation suppressed glycolysis in pancreatic cancer by inhibiting KLF5 m6A methylation through down-regulation of RBM15. This discovery established a solid foundation for the use of in the treatment of pancreatic cancer.

Jiedu Tongluo Tiaogan Formula Modulates Glycolipid Metabolism in Type 2 Diabetes via Pyroptosis: Network Pharmacology and In Vivo Analysis

Type 2 diabetes mellitus (T2DM) is characterized by pancreatic β-cell dysfunction and insulin resistance, with pyroptosis emerging as a key contributor to β-cell loss. Jiedu Tongluo Tiaogan Formula (JTTF), a traditional Chinese medicine (TCM), has shown clinical efficacy in T2DM management, but its mechanism linking pyroptosis remains unexplored. This study integrates UPLC-MS/MS, network pharmacology, and in vivo experiments to elucidate JTTF's anti-diabetic mechanisms. UPLC-MS/MS identified 441 compounds in JTTF, predominantly alkaloids, flavonoids, phenols, and terpenoids. Network pharmacology revealed JTTF's multi-target effects on T2DM-associated pyroptosis, particularly via the NLRP3/Caspase-1/GSDMD pathway. In diabetic mice, JTTF dose-dependently reduced fasting blood glucose, insulin resistance, and dyslipidemia, while restoring pancreatic β-cell morphology. Mechanistically, JTTF suppressed NLRP3 inflammasome activation, downregulated Caspase-1 and GSDMD expression, and attenuated IL-1β/IL-18 release. Notably, this study provides the first evidence of JTTF's anti-pyroptotic effects in T2DM, highlighting its unique ability to modulate glycolipid metabolism and inflammatory cell death concurrently. These findings underscore JTTF's translational promise for preserving β-cell function and suggest future exploration of non-classical pyroptosis pathways. Our work bridges traditional medicine and molecular pharmacology, paving the way for clinical trials and integrative T2DM therapies.

The Role of M6A Modification in Autoimmunity: Emerging Mechanisms and Therapeutic Implications

N6-methyladenosine (m6A), a prevalent and essential RNA modification, serves a key function in driving autoimmune disease pathogenesis. By modulating immune cell development, activation, migration, and polarization, as well as inflammatory pathways, m6A is crucial in forming innate defenses and adaptive immunity. This article provides a comprehensive overview of m6A modification features and reveals how its dysregulation affects the intensity and persistence of immune responses, disrupts immune tolerance, exacerbates tissue damage, and promotes the development of autoimmunity. Specific examples include its contributions to systemic autoimmune disorders like lupus and rheumatoid arthritis, as well as conditions that targeting specific organs like multiple sclerosis and type 1 diabetes. Furthermore, this review explores the therapeutic promise of target m6A-related enzymes ("writers," "erasers," and "readers") and summarizes recent advances in intervention strategies. By focusing on the mechanistic and therapeutic implications of m6A modification, this review sheds light on its role as a promising tool for both diagnosis and treatment in autoimmune disorders, laying the foundation for advancements in customized medicine.

The role and mechanism of m6A methylation in diabetic nephropathy

Diabetic nephropathy (DN) is one of the most common microvascular complications of diabetes mellitus, characterized by progressive deterioration of renal structure and function, which may eventually lead to end-stage kidney disease (ESKD). The N6-methyladenosine (m6A) methylation, an important modality of RNA modification, involves three classes of key regulators, writers (e.g., METTL3), erasers (e.g., FTO, ALKBH5) and readers (e.g., YTHDF2), which play important roles in DN. Writers are responsible for introducing m6A modifications on RNAs, erasers remove m6A modifications and readers recognize and bind m6A-modified RNAs to regulate RNAs functions, such as mRNA stability, translation and localization. In DN, abnormal m6A modification may promote kidney injury and proteinuria by regulating key pathways involved in multiple processes, including lipid metabolism and inflammatory response, in kidney cells such as podocytes. Therefore, an in-depth study of the role and mechanism of m6A methylation that are regulated by "writers", "erasers" and "readers" in DN is expected to provide new targets and strategies for the prevention and treatment of DN.

Investigating the possible mechanism of Cornus officinalis in the therapy of ischemic stroke by UHPLC-Q-TOF-MS, network pharmacology, molecular docking, and experimental verification

ETHNOPHARMACOLOGICAL RELEVANCE

Cornus officinalis is a conventional Chinese medicine for tonifying liver and kidney in ancient China. The active ingredients from Cornus officinalis can delay the progression of cerebral aneurysms, alleviate experimental autoimmune encephalomyelitis, and show a good intervention effect on brain diseases. Loganin, the active ingredient of Cornus officinalis, has a neuroprotective effect on cerebral ischemia-reperfusion injury in mice. It is yet unknown, nevertheless, how Cornus officinalis works to treat ischemic stroke.

AIM OF THE STUDY

Based on ultra-high performance liquid chromatography-quadrupole/time-of-flight mass spectrometry (UHPLC-Q-TOF-MS), network pharmacology and molecular docking, Cornus officinalis's mechanism of intervention in ischemic stroke is explored and verified by experiments.

MATERIALS AND METHODS

To examine the chemical components of Cornus officinalis, UHPLC-Q-TOF-MS was used. The network pharmacology was used to construct the "active ingredient-core target-main pathway" network of Cornus officinalis. Then, the link between the main active components and the key protein targets, as determined by network pharmacology, was verified through the application of molecular docking. The middle cerebral artery occlusion/reperfusion (MCAO/R) rat model used in this study was created using the suture technique. The pharmacological effects of Cornus officinalis were explored by neurological function score, behavior, TTC staining, ultrasound and flow cytometry. Western blot and qPCR were used to confirm the core target.

RESULTS

The outcomes of the investigation demonstrated that Cornus officinalis had a potent anti-ischemic stroke effect. UHPLC-Q-TOF-MS method was used to determine 24 chemical constituents in Cornus officinalis, of which 22 components had a close relationship with protein targets relevant to ischemic stroke. The 27 protein targets screened by "active ingredient-core target-main pathway" may be the possible targets of Cornus officinalis in the therapy of ischemic stroke. Most of the 27 protein targets had to do with the inflammatory response, apoptosis and energy metabolism. KEGG enrichment analysis showed that AGE/RAGE ranked high and was closely related to inflammatory response. Molecular docking predicted that the top 10 components in the network diagram had good binding with inflammatory factors IL6, IL-1β and TNF-α protein targets. Western blot research outcomes stated that Cornus officinalis could firmly impede the production of AGE, RAGE, and P-NFκB P65. Cornus officinalis had the potential to prevent ischemic stroke by drastically inhibiting the production of TNF-α, IL-1β, and IL-6, according to the results of qPCR study.

CONCLUSION

This study found that Cornus officinalis can improve the brain injury, motor ability and blood flow velocity of MCAO/R rats and suppress the inflammatory reaction through the AGE/RAGE/NFκB pathway to exert the therapeutic effect on ischemic stroke.

RBM15 Promotes High Glucose-Induced Lens Epithelial Cell Injury by Inducing PRNP N6-Methyladenine Modification During Diabetic Cataract

PURPOSE

Diabetic cataract (DC) is a major cause of blindness worldwide. Prion protein (PRNP) was proved to be up-regulated and hypomethylated in DC samples. Here, we investigated whether PRNP was involved in DC progression in N6-methyladenosine (m6A)-dependent manner, and its potential mechanisms.

METHODS

Levels of genes and proteins were assayed using qRT-PCR and western blotting. Cell proliferation and apoptosis were determined using Cell Counting Kit-8 assay, 5-thynyl-2'-deoxyuridine (EdU) assay, and flow cytometry, respectively. Oxidative stress was analyzed by measuring the production of glutathione peroxidase (GSH-PX), superoxide dismutase (SOD), and malondialdehyde (MDA). The m6A modification was determined by RNA immunoprecipitation (Me-RIP) assay. The interaction between RBM15 (RNA binding motif protein 15) and PRNP was probed using RIP assay.

RESULTS

PRNP was highly expressed in DC patients and HG-induced HLECs. Functionally, PRNP deficiency reversed HG-induced apoptosis and oxidative stress in HLECs. Mechanistically, RBM15 induced PRNP m6A modification and directly bound to PRNP. Knockdown of RBM15 abolished HG-induced apoptotic and oxidative injury in HLECs, while these effects were rescued after PRNP overexpression.

CONCLUSION

RBM15 silencing suppressed HG-induced lens epithelial cell injury by regulating PRNP in an m6A-mediated manner, hinting a novel therapeutic strategy for DC patients.

Pyroptosis in health and disease: mechanisms, regulation and clinical perspective

Pyroptosis is a type of programmed cell death characterized by cell swelling and osmotic lysis, resulting in cytomembrane rupture and release of immunostimulatory components, which play a role in several pathological processes. Significant cellular responses to various stimuli involve the formation of inflammasomes, maturation of inflammatory caspases, and caspase-mediated cleavage of gasdermin. The function of pyroptosis in disease is complex but not a simple angelic or demonic role. While inflammatory diseases such as sepsis are associated with uncontrollable pyroptosis, the potent immune response induced by pyroptosis can be exploited as a therapeutic target for anti-tumor therapy. Thus, a comprehensive review of the role of pyroptosis in disease is crucial for further research and clinical translation from bench to bedside. In this review, we summarize the recent advancements in understanding the role of pyroptosis in disease, covering the related development history, molecular mechanisms including canonical, non-canonical, caspase 3/8, and granzyme-mediated pathways, and its regulatory function in health and multiple diseases. Moreover, this review also provides updates on promising therapeutic strategies by applying novel small molecule inhibitors and traditional medicines to regulate pyroptosis. The present dilemmas and future directions in the landscape of pyroptosis are also discussed from a clinical perspective, providing clues for scientists to develop novel drugs targeting pyroptosis.

N6-methyladenine RNA methylation epigenetic modification and diabetic microvascular complications

N6-methyladensine (m6A) has been identified as the best-characterized and the most abundant mRNA modification in eukaryotes. It can be dynamically regulated, removed, and recognized by its specific cellular components (respectively called "writers," "erasers," "readers") and have become a hot research field in a variety of biological processes and diseases. Currently, the underlying molecular mechanisms of m6A epigenetic modification in diabetes mellitus (DM) and diabetic microvascular complications have not been extensively clarified. In this review, we focus on the effects and possible mechanisms of m6A as possible potential biomarkers and therapeutic targets in the treatment of DM and diabetic microvascular complications.

METTL Family in Healthy and Disease

Transcription, RNA splicing, RNA translation, and post-translational protein modification are fundamental processes of gene expression. Epigenetic modifications, such as DNA methylation, RNA modifications, and protein modifications, play a crucial role in regulating gene expression. The methyltransferase-like protein (METTL) family, a constituent of the 7-β-strand (7BS) methyltransferase subfamily, is broadly distributed across the cell nucleus, cytoplasm, and mitochondria. Members of the METTL family, through their S-adenosyl methionine (SAM) binding domain, can transfer methyl groups to DNA, RNA, or proteins, thereby impacting processes such as DNA replication, transcription, and mRNA translation, to participate in the maintenance of normal function or promote disease development. This review primarily examines the involvement of the METTL family in normal cell differentiation, the maintenance of mitochondrial function, and its association with tumor formation, the nervous system, and cardiovascular diseases. Notably, the METTL family is intricately linked to cellular translation, particularly in its regulation of translation factors. Members represent important molecules in disease development processes and are associated with patient immunity and tolerance to radiotherapy and chemotherapy. Moreover, future research directions could include the development of drugs or antibodies targeting its structural domains, and utilizing nanomaterials to carry miRNA corresponding to METTL family mRNA. Additionally, the precise mechanisms underlying the interactions between the METTL family and cellular translation factors remain to be clarified.

N6-methyladenosine RNA methylation in diabetic kidney disease

Diabetic kidney disease (DKD) is a major microvascular complication of diabetes, and hyperglycemic memory associated with diabetes carries the risk of disease occurrence, even after the termination of blood glucose injury. The existence of hyperglycemic memory supports the concept of an epigenetic mechanism involving n6-methyladenosine (m6A) modification. Several studies have shown that m6A plays a key role in the pathogenesis of DKD. This review addresses the role and mechanism of m6A RNA modification in the progression of DKD, including the regulatory role of m6A modification in pathological processes, such as inflammation, oxidative stress, fibrosis, and non-coding (nc) RNA. This reveals the importance of m6A in the occurrence and development of DKD, suggesting that m6A may play a role in hyperglycemic memory phenomenon. This review also discusses how some gray areas, such as m6A modified multiple enzymes, interact to affect the development of DKD and provides countermeasures. In conclusion, this review enhances our understanding of DKD from the perspective of m6A modifications and provides new targets for future therapeutic strategies. In addition, the insights discussed here support the existence of hyperglycemic memory effects in DKD, which may have far-reaching implications for the development of novel treatments. We hypothesize that m6A RNA modification, as a key factor regulating the development of DKD, provides a new perspective for the in-depth exploration of DKD and provides a novel option for the clinical management of patients with DKD.