Amelioration of acute myocardial infarction injury through targeted ferritin nanocages loaded with an ALKBH5 inhibitor

m6A control programmed cell death in cardiac fibrosis

N6-methyladenosine (m6A) modification is closely related to cardiac fibrosis. As the most common and abundant form of mRNA modification in eukaryotes, m6A is deposited by methylases ("writers"), recognized and effected by RNA-binding proteins ("readers"), and removed by demethylases ("erasers"), achieving highly dynamic reversibility. m6A modification is involved in regulating the entire biological process of target RNA, including transcription, processing and splicing, export from the nucleus to the cytoplasm, and enhancement or reduction of stability and translation. Programmed cell death (PCD) comprises many forms and pathways, with apoptosis and autophagy being the most common. Other forms include pyroptosis, ferroptosis, necroptosis, mitochondrial permeability transition (MPT)-dependent necrosis, and parthanatos. In recent years, increasing evidence suggests that m6A modification can mediate PCD, affecting cardiac fibrosis. Since the correlation between some PCD types and m6A modification is not yet clear, this article mainly introduces the relationship between four common PCD types (apoptosis, autophagy, pyroptosis, and ferroptosis) and m6A modification, as well as their role and influence in cardiac fibrosis.

M6A modification in cardiovascular disease: With a focus on programmed cell death

N6-methyladenosine (m6A) methylation is one of the most predominant internal RNA modifications in eukaryotes and has become a hot spot in the field of epigenetics in recent years. Cardiovascular diseases (CVDs) are a leading cause of death globally. Emerging evidence demonstrates that RNA modifications, such as the m6A modification, are associated with the development and progression of many diseases, including CVDs. An increasing body of studies has indicated that programmed cell death (PCD) plays a vital role in CVDs. However, the molecular mechanisms underlying m6A modification and PCD in CVDs remain poorly understood. Herein, elaborating on the highly complex connections between the m6A mechanisms and different PCD signaling pathways and clarifying the exact molecular mechanism of m6A modification mediating PCD have significant meaning in developing new strategies for the prevention and therapy of CVDs. There is great potential for clinical application.

Unravelling the impact of RNA methylation genetic and epigenetic machinery in the treatment of cardiomyopathy

Cardiomyopathy (CM) represents a heterogeneous group of diseases primarily affecting cardiac structure and function, with genetic and epigenetic dysregulation playing a pivotal role in its pathogenesis. Emerging evidence from the burgeoning field of epitranscriptomics has brought to light the significant impact of various RNA modifications, notably N6-methyladenosine (m6A), 5-methylcytosine (m5C), N7-methylguanosine (m7G), N1-methyladenosine (m1A), 2'-O-methylation (Nm), and 6,2'-O-dimethyladenosine (m6Am), on cardiomyocyte function and the broader processes of cardiac and vascular remodelling. These modifications have been shown to influence key pathological mechanisms including mitochondrial dysfunction, oxidative stress, cardiomyocyte apoptosis, inflammation, immune response, and myocardial fibrosis. Importantly, aberrations in the RNA methylation machinery have been observed in human CM cases and animal models, highlighting the critical role of RNA methylating enzymes and their potential as therapeutic targets or biomarkers for CM. This review underscores the necessity for a deeper understanding of RNA methylation processes in the context of CM, to illuminate novel therapeutic avenues and diagnostic tools, thereby addressing a significant gap in the current management strategies for this complex disease.

The role of RNA m6A demethylase ALKBH5 in the mechanisms of fibrosis

ALKBH5 is one of the demethylases involved in the regulation of RNA m6A modification. In addition to its role in the dynamic regulation of RNA m6A modification, ALKBH5 has been found to play important roles in various tissues fibrosis processes in recent years. However, the mechanisms and effects of ALKBH5 in fibrosis have been reported inconsistently. Multiple cell types, including parenchymal cells, immune cells (neutrophils and T cells), macrophages, endothelial cells, and fibroblasts, play roles in various stages of fibrosis. Therefore, this review analyzes the mechanisms by which ALKBH5 regulates these cells, its impact on their functions, and the outcomes of fibrosis. Furthermore, this review summarizes the role of ALKBH5 in fibrotic diseases such as pulmonary fibrosis, liver fibrosis, cardiac fibrosis, and renal fibrosis, and discusses various ALKBH5 inhibitors that have been discovered to date, exploring the potential of ALKBH5 as a clinical target for fibrosis.

The potential of RNA methylation in the treatment of cardiovascular diseases

RNA methylation has emerged as a dynamic regulatory mechanism that impacts gene expression and protein synthesis. Among the known RNA methylation modifications, N6-methyladenosine (m6A), 5-methylcytosine (m5C), 3-methylcytosine (m3C), and N7-methylguanosine (m7G) have been studied extensively. In particular, m6A is the most abundant RNA modification and has attracted significant attention due to its potential effect on multiple biological processes. Recent studies have demonstrated that RNA methylation plays an important role in the development and progression of cardiovascular disease (CVD). To identify key pathogenic genes of CVD and potential therapeutic targets, we reviewed several common RNA methylation and summarized the research progress of RNA methylation in diverse CVDs, intending to inspire effective treatment strategies.

N6-Methyladenosine in Vascular Aging and Related Diseases: Clinical Perspectives

Aging leads to progressive deterioration of the structure and function of arteries, which eventually contributes to the development of vascular aging-related diseases. N6-methyladenosine (m6A) is the most prevalent modification in eukaryotic RNAs. This reversible m6A RNA modification is dynamically regulated by writers, erasers, and readers, playing a critical role in various physiological and pathological conditions by affecting almost all stages of the RNA life cycle. Recent studies have highlighted the involvement of m6A in vascular aging and related diseases, shedding light on its potential clinical significance. In this paper, we comprehensively discuss the current understanding of m6A in vascular aging and its clinical implications. We discuss the molecular insights into m6A and its association with clinical realities, emphasizing its significance in unraveling the mechanisms underlying vascular aging. Furthermore, we explore the possibility of m6A and its regulators as clinical indicators for early diagnosis and prognosis prediction and investigate the therapeutic potential of m6A-associated anti-aging approaches. We also examine the challenges and future directions in this field and highlight the necessity of integrating m6A knowledge into patient-centered care. Finally, we emphasize the need for multidisciplinary collaboration to advance the field of m6A research and its clinical application.

N6-methyladenosine demethylase ALKBH5 homologous protein protects against cerebral I/R injury though suppressing SNHG3-mediated neural PANoptosis: Involvement of m6A-related macromolecules in the diseases of nervous system

In order to address this gap in knowledge, the present study utilized both in vivo and in vitro models to investigate the role of the m6A demethylase ALKBH5 in protecting against cerebral I/R injury by inhibiting PANoptosis (Pytoptosis, Ppoptosis, and Necroptosis) in an m6A-dependent manner. They observed that ALKBH5, the predominant m6A demethylase, was downregulated in these models, while SNHG3 and PANoptosis-related proteins (ZBP1, AIM2, Cappase-3, Caspase-8, cleaved Caspase-1, GSDMD-N, and p-MLKL) were elevated. Additionally, both ALKBH5 overexpression and SNHG3-deficiency were found to ameliorate PANoptosis and injury induced by OGD/reperfusion and OGD/RX in both mice tissues and astrocyte cells. Further experiments demonstrated that ALKBH5 induced m6A-demethylation in SNHG3, leading to its degradation. Low expression of SNHG3, on the other hand, prevented the formation of the SNHG3-ELAVL1-ZBP1/AIM2 complex, which in turn destabilized ZBP1 and AIM2 mRNA, resulting in the downregulation of these PANoptosis-related genes. Ultimately, the rescue experiments provided evidence that ALKBH5 protected against PANoptosis in cerebral I/R injury models through the inhibition of SNHG3.This study sheds light on the intricate molecular mechanisms involved in the pathogenesis of cerebral I/R injury and highlights the potential of m6A-related genes as therapeutic targets in this condition.

m6A mRNA methylation-mediated MAPK signaling modulates the nasal mucosa inflammatory response in allergic rhinitis

Background

Allergic rhinitis (AR) is a complex disease in which gene-environment interactions contribute to its pathogenesis. Epigenetic modifications, such as N6-methyladenosine (m6A) modification of mRNA, play important roles in regulating gene expression in multiple physiological and pathological processes. However, the function of m6A modification in AR and the inflammatory response is poorly understood.

Methods

We used the ovalbumin (OVA) and aluminum hydroxide to induce an AR mouse model. Nasal symptoms, histopathology, and serum cytokines were examined. We performed combined m6A and RNA sequencing to analyze changes in m6A modification profiles. Reverse transcription-quantitative polymerase chain reaction (RT-qPCR) and methylated RNA immunoprecipitation sequencing qPCR (MeRIP-qPCR) were used to verify differential methylation of mRNAs and the m6A methylation level. Knockdown or inhibition of Alkbh5 in nasal mucosa of mice was mediated by lentiviral infection or IOX1 treatment.

Results

We showed that m6A was enriched in a group of genes involved in MAPK signaling pathway. Moreover, we identified a MAPK pathway involving Map3k8, Erk2, and Nfκb1 that may play a role in the disrupted inflammatory response associated with nasal inflammation. The m6A eraser, Alkbh5, was highly expressed in the nasal mucosa of AR model mice. Furthermore, knockdown of Alkbh5 expression by lentiviral infection resulted in high MAPK pathway activity and a significant nasal mucosa inflammatory response. Our findings indicate that ALKBH5-mediated m6A dysregulation likely contributes to a nasal inflammatory response via the MAPK pathway.

Conclusion

Together, our data show that m6A dysregulation mediated by ALKBH5, is likely to contribute to inflammation of the nasal mucosa via the MAPK signaling pathway, suggesting that ALKBH5 is a potential biomarker for AR treatment.

Methylation modifications in tRNA and associated disorders: Current research and potential therapeutic targets

High-throughput sequencing has sparked increased research interest in RNA modifications, particularly tRNA methylation, and its connection to various diseases. However, the precise mechanisms underpinning the development of these diseases remain largely elusive. This review sheds light on the roles of several tRNA methylations (m1A, m3C, m5C, m1G, m2G, m7G, m5U, and Nm) in diverse biological functions, including metabolic processing, stability, protein interactions, and mitochondrial activities. It further outlines diseases linked to aberrant tRNA modifications, related enzymes, and potential underlying mechanisms. Moreover, disruptions in tRNA regulation and abnormalities in tRNA-derived small RNAs (tsRNAs) contribute to disease pathogenesis, highlighting their potential as biomarkers for disease diagnosis. The review also delves into the exploration of drugs development targeting tRNA methylation enzymes, emphasizing the therapeutic prospects of modulating these processes. Continued research is imperative for a comprehensive comprehension and integration of these molecular mechanisms in disease diagnosis and treatment.

N6-methyladenosine (m6A) modification in hepatocellular carcinoma

Hepatocellular carcinoma (HCC) is one of the deadliest cancers of human, the tumor-related death of which ranks third among the common malignances. N6-methyladenosine (m6A) methylation, the most abundant internal modification of RNA in mammals, participates in the metabolism of mRNA and interrelates with ncRNAs. In this paper, we overviewed the complex function of m6A regulators in HCC, including regulating the tumorigenesis, progression, prognosis, stemness, metabolic reprogramming, autophagy, ferroptosis, drug resistance and tumor immune microenvironment (TIME). Furthermore, we elucidated the interplay between m6A modification and non-coding RNAs (ncRNAs), including microRNAs (miRNAs), long non-coding RNAs (lncRNAs) and circular RNAs (circRNAs). Finally, we summarized the potential of m6A regulators as diagnostic biomarkers. What's more, we reviewed the inhibitors targeting m6A enzymes as promising therapeutic targets of HCC. We aimed to help understand the function of m6A methylation in HCC systematically and comprehensively so that more effective strategies for HCC treatment will be developed.

ALKBH5-mediated m6A demethylation of pri-miR-199a-5p exacerbates myocardial ischemia/reperfusion injury by regulating TRAF3-mediated pyroptosis

Myocardial ischemia‒reperfusion injury (MI/RI) is closely related to pyroptosis. alkB homolog 5 (ALKBH5) is abnormally expressed in the MI/RI models. However, the detailed molecular mechanism of ALKBH5 in MI/RI has not been elucidated. In this study, rats and H9C2 cells served as experimental subjects and received MI/R induction and H/R induction, respectively. The abundance of the targeted molecules was evaluated using RT-qPCR, Western blotting, immunohistochemistry, immunofluorescence, and enzyme-linked immunosorbent assay. The heart functions of the rats were evaluated using echocardiography, and heart injury was evaluated. Cell viability and pyroptosis were determined using cell counting Kit-8 and flow cytometry, respectively. Total m6A modification was measured using a commercial kit, and pri-miR-199a-5p m6A modification was detected by Me-RNA immunoprecipitation (RIP) assay. The interactions among the molecules were validated using RIP and luciferase experiments. ALKBH5 was abnormally highly expressed in H/R-induced H9C2 cells and MI/RI rats. ALKBH5 silencing improved injury and inhibited pyroptosis. ALKBH5 reduced pri-miR-199a-5p m6A methylation to block miR-199a-5p maturation and inhibit its expression. TNF receptor-associated Factor 3 (TRAF3) is a downstream gene of miR-199a-5p. Furthermore, in H/R-induced H9C2 cells, the miR-199a-5p inhibitor-mediated promotion of pyroptosis was reversed by ALKBH5 silencing, and the TRAF3 overexpression-mediated promotion of pyroptosis was offset by miR-199a-5p upregulation. ALKBH5 silencing inhibited pri-miR-199a-5p expression and enhanced pri-miR-199a-5p m6A modification to promote miR-199a-5p maturation and enhance its expression, thereby suppressing pyroptosis to alleviate MI/RI through decreasing TRAF3 expression.

Enhanced TfR1 Recognition of Myocardial Injury after Acute Myocardial Infarction with Cardiac Fibrosis via Pre-Degrading Excess Fibrotic Collagen

The fibrosis process after myocardial infarction (MI) results in a decline in cardiac function due to fibrotic collagen deposition and contrast agents' metabolic disorders, posing a significant challenge to conventional imaging strategies in making heart damage clear in the fibrosis microenvironment. To address this issue, we developed an imaging strategy. Specifically, we pretreated myocardial fibrotic collagen with collagenase I combined with human serum albumin (HSA-C) and subsequently visualized the site of cardiac injury by near-infrared (NIR) fluorescence imaging using an optical contrast agent (CI, CRT-indocyanine green) targeting transferrin receptor 1 peptides (CRT). The key point of this strategy is that pretreatment with HSA-C can reduce background signal interference in the fibrotic tissue while enhancing CI uptake at the heart lesion site, making the boundary between the injured heart tissue and the normal myocardium clearer. Our results showed that compared to that in the untargeted group, the normalized fluorescence intensity of cardiac damage detected by NIR in the targeted group increased 1.28-fold. The normalized fluorescence intensity increased 1.21-fold in the pretreatment group of the targeted groups. These data demonstrate the feasibility of applying pretreated fibrotic collagen and NIR contrast agents targeting TfR1 to identify ferroptosis at sites of cardiac injury, and its clinical value in the management of patients with MI needs further study.

Characterization of the m6A regulators' landscape highlights the clinical significance of acute myocardial infarction

Objective

Acute myocardial infarction (AMI) is a severe cardiovascular disease that threatens human life and health globally. N6-methyladenosine (m6A) governs the fate of RNAs via m6A regulators. Nevertheless, how m6A regulators affect AMI remains to be deciphered. To solve this issue, an integrative analysis of m6A regulators in AMI was conducted.

Methods

We acquired transcriptome profiles (GSE59867, GSE48060) of peripheral blood samples from AMI patients and healthy controls. Key m6A regulators were used for LASSO, and consensus clustering was conducted. Next, the m6A score was also computed. Immune cell infiltration, ferroptosis, and oxidative stress were evaluated. In-vitro and in-vivo experiments were conducted to verify the role of the m6A regulator ALKBH5 in AMI.

Results

Most m6A regulators presented notable expression alterations in circulating cells of AMI patients versus those of controls. Based on key m6A regulators, we established a gene signature and a nomogram for AMI diagnosis and risk prediction. AMI patients were classified into three m6A clusters or gene clusters, respectively, and each cluster possessed the unique properties of m6A modification, immune cell infiltration, ferroptosis, and oxidative stress. Finally, the m6A score was utilized to quantify m6A modification patterns. Therapeutic targeting of ALKBH5 greatly alleviated apoptosis and intracellular ROS in H/R-induced H9C2 cells and NRCMs.

Conclusion

Altogether, our findings highlight the clinical significance of m6A regulators in the diagnosis and risk prediction of AMI and indicate the critical roles of m6A modification in the regulation of immune cell infiltration, ferroptosis, and oxidative stress.

N6-methyladenosine modification in ischemic stroke: Functions, regulation, and therapeutic potential

N6-methyladenosine (m6A) modification is the most frequently occurring internal modification in eukaryotic RNAs. By modulating various aspects of the RNA life cycle, it has been implicated in a wide range of pathological and physiological processes associated with human diseases. Ischemic stroke is a major cause of death and disability worldwide with few treatment options and a narrow therapeutic window, and accumulating evidence has indicated the involvement of m6A modifications in the development and progression of this type of stroke. In this review, which provides insights for the prevention and clinical treatment of stroke, we present an overview of the roles played by m6A modification in ischemic stroke from three main perspectives: (1) the association of m6A modification with established risk factors for stroke, including hypertension, diabetes mellitus, hyperlipidemia, obesity, and heart disease; (2) the roles of m6A modification regulators and their functional regulation in the pathophysiological injury mechanisms of stroke, namely oxidative stress, mitochondrial dysfunction, endothelial dysfunction, neuroinflammation, and cell death processes; and (3) the diagnostic and therapeutic potential of m6A regulators in the treatment of stroke.

Alkylation Repair Homolog 5 Regulates N(6)-methyladenosine (m6A) Methylation of Mitsugumin 53 to Attenuate Myocardial Infarction by Inhibiting Apoptosis and Oxidative Stress

ABSTRACT

N(6)-methyladenosine (m6A) methylation modification is involved in the progression of myocardial infarction (MI). In this study, we investigated the effects of demethylase alkylation repair homolog 5 (ALKBH5) on cell apoptosis and oxidative stress in MI. The ischemia/reperfusion (I/R) injury mouse model and hypoxia/reoxygenation (H/R) cell model were established. The levels of ALKBH5 and mitsugumin 53 (MG53) were measured by quantitative real-time polymerase chain reaction, immunohistochemical, and immunofluorescence analysis. Apoptosis was evaluated by TUNEL assay, flow cytometry, and western blot. Oxidative stress was assessed by antioxidant index kits. Methylation was analyzed by RNA binding protein immunoprecipitation (RIP), MeRIP, and dual-luciferase reporter assay. We observed that ALKBH5 and MG53 were highly expressed in MI. Overexpression of ALKBH5 inhibited H/R-induced cardiomyocyte apoptosis and oxidative stress in vitro, and it inhibited I/R-induced collagen deposition, cardiac function, and apoptosis in vivo. ALKBH5 could bind to MG53, inhibit m6A methylation of MG53, and increase its mRNA stability. Silencing of MG53 counteracted the inhibition of apoptosis and oxidative stress induced by ALKBH5. In conclusion, ALKBH5 suppressed m6A methylation of MG53 and inhibited MG53 degradation to inhibit apoptosis and oxidative stress of cardiomyocytes, thereby attenuating MI. The results provided a theoretical basis that ALKBH5 is a potential target for MI treatment.

Multifaceted Applications of Ferritin Nanocages in Delivering Metal Ions, Bioactive Compounds, and Enzymes: A Comprehensive Review

Ferritin, a distinctive iron-storage protein, possesses a unique cage-like nanoscale structure that enables it to encapsulate and deliver a wide range of biomolecules. Recent advances prove that ferritin can serve as an efficient 8 nm diameter carrier for various bioinorganic nutrients, such as minerals, bioactive polyphenols, and enzymes. This review offers a comprehensive summary of ferritin's structural features from different sources and emphasizes its functions in iron supplementation, calcium delivery, single- and coencapsulation of polyphenols, and enzyme package. Additionally, the influence of innovative food processing technologies, including manothermosonication, pulsed electric field, and atmospheric cold plasma, on the structure and function of ferritin are examined. Furthermore, the limitations and prospects of ferritin in food and nutritional applications are discussed. The exploration of ferritin as a multifunctional protein with the capacity to load various biomolecules is crucial to fully harnessing its potential in food applications.

Key m6A regulators mediated methylation modification pattern and immune infiltration characterization in hepatic ischemia-reperfusion injury

BACKGROUND

N6-methyladenosine (m6A) mRNA modification plays a critical role in various human biological processes. However, there has been no study reported to elucidate its role in hepatic ischemia-reperfusion injury (IRI). This study was aimed to explore the expression pattern together with the potential functions of m6A regulators in hepatic IRI.

METHODS

The gene expression data (GSE23649) of m6A regulators in human liver tissue samples before cold perfusion and within 2 h after portal vein perfusion from Gene Expression Omnibus database was analyzed. The candidate m6A regulators were screened using random forest (RF) model to predict the risk of hepatic IRI. The evaluation of infiltrating abundance of 23 immune cells was performed using single sample gene set enrichment analysis. Besides, quantitative real time polymerase chain reaction (qRT-PCR) assay was carried out to validate the expression of key m6A regulators in mouse hepatic IRI model.

RESULTS

The expressions of WTAP, CBLL1, RBM15, and YTHDC1 were found to be increased in liver tissues 2 h after portal vein perfusion; in contrast, the expressions of LRPPRC, FTO, METTL3, and ALKBH5 were decreased. Based on RF model, we identified eight m6A methylation regulators for the prediction of the risk of hepatic IRI. Besides, a nomogram was built to predict the probability of hepatic IRI. In addition, the levels of WTAP, ALKBH5, CBLL1, FTO, RBM15B, LRPPRC and YTHDC1 were correlated with the immune infiltration of activated CD4 T cell, activated dendritic cell (DC), immature DC, mast cell, neutrophil, plasmacytoid DC, T helper (Th) cell (type 1, 2, and 17), gamma delta T cell, T follicular helper (Tfh) cell, myeloid-derived suppressor cell (MDSC), macrophage, natural killer cell, and regulatory Th cell. Among mouse hepatic IRI model, the mRNA level of CBLL1 and YTHDC1 was increased with statistical significance; however, the mRNA level of FTO and METTL3 was decreased among post-reperfusion liver samples compared with those in pre-reperfusion samples with statistical significance.

CONCLUSIONS

The m6A regulators exerted a pivotal impact on hepatic IRI. The m6A patterns that found in this study might provide novel targets and strategies for the alleviation/treatment of hepatic IRI in the future.

RNA modification in cardiovascular disease: implications for therapeutic interventions

Cardiovascular disease (CVD) is the leading cause of death in the world, with a high incidence and a youth-oriented tendency. RNA modification is ubiquitous and indispensable in cell, maintaining cell homeostasis and function by dynamically regulating gene expression. Accumulating evidence has revealed the role of aberrant gene expression in CVD caused by dysregulated RNA modification. In this review, we focus on nine common RNA modifications: N6-methyladenosine (m6A), N1-methyladenosine (m1A), 5-methylcytosine (m5C), N7-methylguanosine (m7G), N4-acetylcytosine (ac4C), pseudouridine (Ψ), uridylation, adenosine-to-inosine (A-to-I) RNA editing, and modifications of U34 on tRNA wobble. We summarize the key regulators of RNA modification and their effects on gene expression, such as RNA splicing, maturation, transport, stability, and translation. Then, based on the classification of CVD, the mechanisms by which the disease occurs and progresses through RNA modifications are discussed. Potential therapeutic strategies, such as gene therapy, are reviewed based on these mechanisms. Herein, some of the CVD (such as stroke and peripheral vascular disease) are not included due to the limited availability of literature. Finally, the prospective applications and challenges of RNA modification in CVD are discussed for the purpose of facilitating clinical translation. Moreover, we look forward to more studies exploring the mechanisms and roles of RNA modification in CVD in the future, as there are substantial uncultivated areas to be explored.

ALKBH5 causes retinal pigment epithelium anomalies and choroidal neovascularization in age-related macular degeneration via the AKT/mTOR pathway

Retinal pigment epithelium (RPE) dysfunction and choroidal neovascularization (CNV) are predominant features of age-related macular degeneration (AMD), with an unclear mechanism. Herein, we show that RNA demethylase α-ketoglutarate-dependent dioxygenase alkB homolog 5 (ALKBH5) is up-regulated in AMD. In RPE cells, ALKBH5 overexpression associates with depolarization, oxidative stress, disturbed autophagy, irregular lipid homeostasis, and elevated VEGF-A secretion, which subsequently promotes proliferation, migration, and tube formation of vascular endothelial cells. Consistently, ALKBH5 overexpression in mice RPE correlates with various pathological phenotypes, including visual impairments, RPE anomalies, choroidal neovascularization (CNV), and interrupted retinal homeostasis. Mechanistically, ALKBH5 regulates retinal features through its demethylation activity. It targets PIK3C2B and regulates the AKT/mTOR signaling pathway with YTHDF2 as the N⁶-methyladenosine reader. IOX1, an ALKBH5 inhibitor, suppresses hypoxia-induced RPE dysfunction and CNV progression. Collectively, we demonstrate that ALKBH5 induces RPE dysfunction and CNV progression in AMD via PIK3C2B-mediated activation of the AKT/mTOR pathway. Pharmacological inhibitors of ALKBH5, like IOX1, are promising therapeutic options for AMD.

Critical roles of m6A methylation in cardiovascular diseases

Cardiovascular diseases (CVDs) have been established as a major cause of mortality globally. However, the exact pathogenesis remains obscure. N6-methyladenosine (m⁶A) methylation is the most common epigenetic modification on mRNAs regulated by methyltransferase complexes (writers), demethylase transferases (erasers) and binding proteins (readers). It is now understood that m⁶A is a major player in physiological and pathological cardiac processes. m⁶A methylation are potentially involved in many mechanisms, for instance, regulation of calcium homeostasis, endothelial function, different forms of cell death, autophagy, endoplasmic reticulum stress, macrophage response and inflammation. In this review, we will summarize the molecular functions of m⁶A enzymes. We mainly focus on m⁶A-associated mechanisms and functions in CVDs, especially in heart failure and ischemia heart disease. We will also discuss the potential application and clinical transformation of m⁶A modification.

Aberrant RNA m6A modification in gastrointestinal malignancies: versatile regulators of cancer hallmarks and novel therapeutic opportunities

Gastrointestinal (GI) cancer is one of the most common malignancies, and a leading cause of cancer-related death worldwide. However, molecular targeted therapies are still lacking, leading to poor treatment efficacies. As an important layer of epigenetic regulation, RNA N6-Methyladenosine (m⁶A) modification is recently linked to various biological hallmarks of cancer by orchestrating RNA metabolism, including RNA splicing, export, translation, and decay, which is partially involved in a novel biological process termed phase separation. Through these regulatory mechanisms, m⁶A dictates gene expression in a dynamic and reversible manner and may play oncogenic, tumor suppressive or context-dependent roles in GI tumorigenesis. Therefore, regulators and effectors of m⁶A, as well as their modified substrates, represent a novel class of molecular targets for cancer treatments. In this review, we comprehensively summarize recent advances in this field and highlight research findings that documented key roles of RNA m⁶A modification in governing hallmarks of GI cancers. From a historical perspective, milestone findings in m⁶A machinery are integrated with a timeline of developing m⁶A targeting compounds. These available chemical compounds, as well as other approaches that target core components of the RNA m⁶A pathway hold promises for clinical translational to treat human GI cancers. Further investigation on several outstanding issues, e.g. how oncogenic insults may disrupt m⁶A homeostasis, and how m⁶A modification impacts on the tumor microenvironment, may dissect novel mechanisms underlying human tumorigenesis and identifies next-generation anti-cancer therapeutics. In this review, we discuss advances in our understanding of m⁶A RNA modification since its discovery in the 1970s to the latest progress in defining its potential clinic relevance. We summarize the molecular basis and roles of m⁶A regulators in the hallmarks of GI cancer and discuss their context-dependent functions. Furthermore, the identification and characterization of inhibitors or activators of m⁶A regulators and their potential anti-cancer effects are discussed. With the rapid growth in this field there is significant potential for developing m⁶A targeted therapy in GI cancers.

Suxiao Jiuxin Pill alleviates myocardial ischemia-reperfusion injury through the ALKBH5/GSK3β/mTOR pathway

BACKGROUND

Many studies have shown effective protection from myocardial ischemia-reperfusion injury (MIRI) in animal models, but few, if any, treatments have yielded a substantial reduction in clinical. Several studies showed significant therapeutic effects for the Chinese patent medicine Suxiao Jiuxin Pill (SJP) in MIRI, although the specific molecular mechanisms remain undefined. Recently, increasing evidence indicates an important role for m6A modification in autophagy regulation in MIRI, and SJP has not been investigated in this regard.

METHODS

In vivo experiments were performed in a Wistar rat MIRI model. In vitro assays were conducted in hypoxia/reoxygenation (H/R)-treated H9c2 cells. H9c2 cells with ALKBH5 and GSK3β silencing were constructed by lentivirus transfection. TUNEL and Annexin V/PI assays were carried out for apoptosis detection. Then, m6A modification was detected with the EpiQuik m6A RNA methylation quantification kit, and GFP-RFP-LC3B was used to observe dynamic changes in autophagy. The autophagosome structure was assessed by Transmission electron microscopy. qPCR and immunoblot were performed for mRNA and protein analyses, receptively.

RESULTS

SJP significantly mitigated MIRI in rats, reducing infarct size and myocardial apoptosis, and improving left ventricular function. In addition, SJP inhibited autophagy through the GSK3β/mTOR pathway in MIRI rats. In cultured H9c2 cells, SJP significantly inhibited H/R- related apoptosis and autophagic activity through the GSK3β/mTOR pathway. Additionally, SJP enhanced ALKBH5 expression in H/R cardiomyocytes, which is important in impaired m6A modification. Interestingly, ALKBH5 knockdown enhanced autophagy and apoptosis in H/R-induced cells, whereas SJP reversed these effects. Further experiments showed that autophagic activity and apoptosis enhanced by ALKBH5 deficiency are GSK3β/mTOR pathway dependent in H/R-treated H9c2 cells. After SJP administration the above effects were alleviated, suggesting SJP inhibited autophagy through the ALKBH5/GSK3β/mTOR pathway in H/R-induced cardiomyocytes. These effects of SJP were common to its two main constituents, including tetra-methylpyrazine (TMP) and borneol (BOR).

CONCLUSION

SJP improves MIRI in rats and alleviates autophagy and apoptosis in H9c2 cells through the ALKBH5/GSK3β/mTOR pathway, thanks to its two major constituents TMP and BOR.

Inhibition of ALKBH5 attenuates I/R-induced renal injury in male mice by promoting Ccl28 m6A modification and increasing Treg recruitment

Ischemia reperfusion injury (IRI) is a common cause of acute kidney injury (AKI). The role of N^6-methyladenosine (m6A) modification in AKI remains unclear. Here, we characterize the role of AlkB homolog 5 (ALKBH5) and m6A modification in an I/R-induced renal injury model in male mice. Alkbh5-knockout mice exhibit milder pathological damage and better renal function than wild-type mice post-IRI, whereas Alkbh5-knockin mice show contrary results. Also conditional knockout of Alkbh5 in the tubular epithelial cells alleviates I/R-induced AKI and fibrosis. CCL28 is identified as a target of ALKBH5. Furthermore, Ccl28 mRNA stability increases with Alkbh5 deficiency, mediating by the binding of insulin-like growth factor 2 binding protein 2. Treg recruitment is upregulated and inflammatory cells are inhibited by the increased CCL28 level in IRI-Alkbh5^fl/flKsp^Cre mice. The ALKBH5 inhibitor IOX1 exhibits protective effects against I/R-induced AKI. In summary, inhibition of ALKBH5 promotes the m6A modifications of Ccl28 mRNA, enhancing its stability, and regulating the Treg/inflammatory cell axis. ALKBH5 and this axis is a potential AKI treatment target.

Ferritin-based nanomedicine for disease treatment

Ferritin is an endogenous protein which is self-assembled by 24 subunits into a highly uniform nanocage structure. Due to the drug-encapsulating ability in the hollow inner cavity and abundant modification sites on the outer surface, ferritin nanocage has been demonstrated great potential to become a multi-functional nanomedicine platform. Its good biocompatibility, low toxicity and immunogenicity, intrinsic tumor-targeting ability, high stability, low cost and massive production, together make ferritin nanocage stand out from other nanocarriers. In this review, we summarized ferritin-based nanomedicine in field of disease diagnosis, treatment and prevention. The different types of drugs to be loaded in ferritin, as well as drug-loading methods were classified. The strategies for site-specific and non-specific functional modification of ferritin were investigated, then the application of ferritin for disease imaging, drug delivery and vaccine development were discussed. Finally, the challenges restricting the clinical translation of ferritin-based nanomedicines were analyzed.

N6-methyladenosine in macrophage function: a novel target for metabolic diseases

N6-methyladenosine (m⁶A) is one of the most prevalent internal transcriptional modifications. Evidence has highlighted changes in m⁶A in metabolic disorders and various metabolic diseases. However, the precise mechanisms of these m⁶A changes in such conditions are not understood. Macrophages are crucial for the innate immune system and exert either beneficial or harmful roles in metabolic disease. Notably, m⁶A was found to be closely related to macrophage phenotype and dysfunction. In this review, we summarize m⁶A in macrophage function from the perspective of macrophage development, activation, and polarization, pyroptosis, and metabolic disorders. Furthermore, we discuss how m⁶A-mediated macrophage function affects metabolic diseases, including atherosclerosis and nonalcoholic fatty liver disease (NAFLD). Finally, we discuss challenges and prospects for m⁶A in macrophage and metabolic diseases with the aim of providing guidance for the treatment of metabolic diseases.

RNA modifications in cardiovascular health and disease

RNA is not always a faithful copy of DNA. Advances in tools enabling the interrogation of the exact RNA sequence have permitted revision of how genetic information is transferred. We now know that RNA is a dynamic molecule, amenable to chemical modifications of its four canonical nucleotides by dedicated RNA-binding enzymes. The ever-expanding catalogue of identified RNA modifications in mammals has led to a burst of studies in the past 5 years that have explored the biological relevance of the RNA modifications, also known as epitranscriptome. These studies concluded that chemical modification of RNA nucleotides alters several properties of RNA molecules including sequence, secondary structure, RNA-protein interaction, localization and processing. Importantly, a plethora of cellular functions during development, homeostasis and disease are controlled by RNA modification enzymes. Understanding the regulatory interface between a single-nucleotide modification and cellular function will pave the way towards the development of novel diagnostic, prognostic and therapeutic tools for the management of diseases, including cardiovascular disease. In this Review, we use two well-studied and abundant RNA modifications - adenosine-to-inosine RNA editing and N⁶-methyladenosine RNA methylation - as examples on which to base the discussion about the current knowledge on installation or removal of RNA modifications, their effect on biological processes related to cardiovascular health and disease, and the potential for development and application of epitranscriptome-based prognostic, diagnostic and therapeutic tools for cardiovascular disease.

A pH/H2 O2 /MMP9 Time-Response Gel System with Sparchigh Tregs Derived Extracellular Vesicles Promote Recovery After Acute Myocardial Infarction

Regulatory T cells overexpressing SPARC (secreted protein acidic and cysteine rich) (Sparc^high Tregs) can help repair infarct tissues after acute myocardial infarction (AMI). This research demonstrates that Sparc^high Treg-derived extracellular vesicles (EVs) effectively improved cardiac function through proinflammatory factors IL-1β, IL-6, and TNF-α inhibition and collagen synthesis related gene Col3a1 promotion in AMI; moreover, a composite hydrogel-EVs system (DHPM(4APPC)_EVs) is designed based on Sparc^high Treg-derived EVs with CXCR2 overexpressing and pH/H₂ O₂ /MMP9 temporally responsive gel microspheres. In AMI, due to the levels of chemokine, pH, H₂ O₂ , and MMP9 enzymes in the infarct area, DHPM(4APPC)_EVs can effectively target the infarct area, release the loaded EVs, form the gel to capture the released EVs, and slowly release the captured EVs, contribute to promote EVs to stay in the infarct area for a long time to play the repair function, so as to reduce myocardial injury and promote the improvement of cardiac function. The proposed system in this research provides a potential approach for the treatment of AMI in the future.

N6-methyladenosine modification: A potential regulatory mechanism in spinal cord injury

N6-methyladenosine (m6A), an essential post-transcriptional modification in eukaryotes, is closely related to the development of pathological processes in neurological diseases. Notably, spinal cord injury (SCI) is a serious traumatic disease of the central nervous system, with a complex pathological mechanism which is still not completely understood. Recent studies have found that m6A modification levels are changed after SCI, and m6A-related regulators are involved in the changes of the local spinal cord microenvironment after injury. However, research on the role of m6A modification in SCI is still in the early stages. This review discusses the latest progress in the dynamic regulation of m6A modification, including methyltransferases (“writers”), demethylases (“erasers”) and m6A -binding proteins (“readers”). And then analyses the pathological mechanism relationship between m6A and the microenvironment after SCI. The biological processes involved included cell death, axon regeneration, and scar formation, which provides new insight for future research on the role of m6A modification in SCI and the clinical transformation of strategies for promoting recovery of spinal cord function.

Ferritin nanocage based delivery vehicles: From single-, co- to compartmentalized- encapsulation of bioactive or nutraceutical compounds

Bioactive or nutraceutical ingredients have been widely used in pursuit of health and well-being. However, the environmental instability, poor solubility and bioavailability, and unspecific delivery highly limited their practical values. By virtue of the unique shell-like structure, definite disassembly/reassembly behavior, and excellent safety profile of ferritin protein, it stands out among of various nano-materials and is emerging as one of the most promising vehicles for the encapsulation and delivery of bioactive ingredients or drugs. In this review, we present a systematic overview of recent advances of ferritin-based delivery systems from single-encapsulation, co-encapsulation, to compartmentalized-encapsulation of bioactive ingredients or drugs. Different encapsulation strategies for cargo loading as well as their advantages and drawbacks have been critically reviewed. This study emphasized the importance of the construction of compartmentalized delivery systems through the usage of ferritin nanocages, which exhibit great potential for facilitating the synergistic functionality of different types of cargos. Lastly, the applications of ferritin nanocages for physicochemical improvements and functionality achievements of loaded cargos are summarized. In conclusion, ferritin protein nanocages not only are excellent nanocarriers, but also can act as"multi-seated" vehicles for co-encapsulation and compartmentalized encapsulation of different cargos simultaneously.

N(6)-methyladenosine modification: A vital role of programmed cell death in myocardial ischemia/reperfusion injury

N(6)-methyladenosine (m⁶A) modification is closely associated with myocardial ischemia/reperfusion injury (MIRI). As the most common modification among RNA modifications, the reversible m⁶A modification is processed by methylase ("writers") and demethylase ("erasers"). The biological effects of RNA modified by m⁶A are regulated under the corresponding RNA binding proteins (RBPs) ("readers"). m⁶A modification regulates the whole process of RNA, including transcription, processing, splicing, nuclear export, stability, degradation, and translation. Programmed cell death (PCD) is a regulated mechanism that maintains the internal environment's stability. PCD plays an essential role in MIRI, including apoptosis, autophagy, pyroptosis, ferroptosis, and necroptosis. However, the relationship between PCD modified with m⁶A and MIRI is still not clear. This review summarizes the regulators of m⁶A modification and their bioeffects on PCD in MIRI.

N6-methyladenosine (m6A) modification in gynecological malignancies

N6-methyladenosine (m6A) modification is one of the most abundant modifications in eukaryotic mRNA, regulated by m6A methyltransferase and demethylase. m6A modified RNA is specifically recognized and bound by m6A recognition proteins, which mediate splicing, maturation, exonucleation, degradation, and translation. In gynecologic malignancies, m6A RNA modification-related molecules are expressed aberrantly, significantly altering the posttranscriptional methylation level of the target genes and their stability. The m6A modification also regulates related metabolic pathways, thereby controlling tumor development. This review analyzes the composition and mode of action of m6A modification-related proteins and their biological functions in the malignant progression of gynecologic malignancies, which provide new ideas for the early clinical diagnosis and targeted therapy of gynecologic malignancies.

Cyclosporine A loaded brain targeting nanoparticle to treat cerebral ischemia/reperfusion injury in mice

BACKGROUND

Ischemic stroke is one of the main causes of death and disability in the world. The treatment for ischemic stroke is to restore blood perfusion as soon as possible. However, when ischemic brain tissue is re-perfused by blood, the mitochondrial permeability transition pore (mPTP) in neuron and microglia is excessively opened, resulting in the apoptosis of neuron and nerve inflammation. This aggravates nerve injury. Cyclosporine A (CsA) inhibits the over-opening of mPTP, subsequently reducing the release of ROS and the apoptosis of cerebral ischemia/reperfusion injured neuron and microglia. However, CsA is insoluble in water and present in high concentrations in lymphatic tissue. Herein, cerebral infarction tissue targeted nanoparticle (CsA@HFn) was developed to treat cerebral ischemia/reperfusion injury.

RESULTS

CsA@HFn efficiently penetrated the blood-brain barrier (BBB) and selectively accumulated in ischemic area, inhibiting the opening of mPTP and ROS production in neuron. This subsequently reduced the apoptosis of neuron and the damage of BBB. Consequently, CsA@HFn significantly reduced the infarct area. Moreover, CsA@HFn inhibited the recruitment of astrocytes and microglia in ischemic region and polarized microglia into M2 type microglia, which subsequently alleviated the nerve inflammation.

CONCLUSIONS

CsA@HFn showed a significant therapeutic effect on cerebral ischemia/reperfusion injury by alleviating the apoptosis of neuron, nerve inflammation and the damage of BBB in ischemic area. CsA@HFn has great potential in the treatment of ischemic stroke.

N6-Methyladenosine RNA Methylation in Cardiovascular Diseases

N6-methyladenosine (m6A) modification is the most universal and abundant post-transcriptional modification of eukaryotic RNA and occurs mainly at the consensus motif RR (m6A) CH (R = A or G, H = A, C, or U) in long internal exons, near stop codons, or in the 3' untranslated region (UTR). "Writers," "erasers," and "readers" are responsible for the occurrence, removal, and recognition of m6A modification, respectively. Substantial evidence has shown that m6A RNA modification can exert important functions in physiological and pathological processes. Cardiovascular diseases (CVDs) are a wide array of disorders affecting heart or vessels, including atherosclerosis (AS), hypertension (HT), ischemia/reperfusion (I/R) injury, myocardial infarction (MI), stroke, cardiac hypertrophy, heart failure (HF), and so on. Despite the advances in lipid-lowering drugs, antihypertensives, antiplatelet agents, and anticoagulation therapy, CVDs are still the leading cause of death worldwide. Recent studies have suggested that m6A modification of RNA may contribute to the pathogenesis of CVDs, providing a novel research insight for CVDs. Herein, we provide an up-of-date summarization of the molecular mechanism of m6A and the roles of m6A in different types of CVDs. At last, we propose that m6A might be a potiential biomarker or therapeutic target for CVDs.