Long non-coding RNA H19 protects against intracerebral hemorrhage injuries via regulating microRNA-106b-5p/acyl-CoA synthetase long chain family member 4 axis

Detection and analysis of plasma lncRNA, miRNA and mRNA profile in preterm birth with intraventricular hemorrhage

Intraventricular hemorrhage (IVH) is a cause of morbidity and mortality in preterm infants and is strongly associated with adverse neurological outcomes. The incidence of severe IVH (grade 3 or 4) has persisted despite the overall decline in IVH. IVH has been attributed to changes in cerebral blood flow to the immature germinal matrix microvasculature. The cascade of adverse events following IVH includes inflammation, white matter injury, and delayed oligodendrial maturation. In this study, we aimed to identify long non-coding RNA (lncRNA), microRNA (miRNA), and messenger RNA (mRNA) expression in the peripheral blood of preterm infants with IVH compared to normal controls, resulting in the finding of novel biomarkers for IVH. We conducted transcriptome sequencing and small RNA sequencing for identifying differential expression of RNA in preterm infants with IVH. We identified differentially expressed 47 lncRNAs, 95 miRNAs, and 1,370 mRNAs in preterm infants with IVH compared to normal control. Particularly, lncRNA H19 exhibited significantly high expression in preterm infants with IVH. The functional analysis revealed that differentially expressed RNAs in preterm infants with IVH were associated with ferroptosis, heme metabolism, and immune response such as lymphocyte activation and interferon response. In conclusion, these results demonstrate the potential of lncRNA, miRNA, mRNA as possible diagnostic and prognostic biomarkers for IVH.

The interplay of miRNAs and ferroptosis in diseases related to iron overload

Ferroptosis has been conceptualized as a novel cell death modality distinct from apoptosis, necroptosis, pyroptosis and autophagic cell death. The sensitivity of cellular ferroptosis is regulated at multiple layers, including polyunsaturated fatty acid metabolism, glutathione-GPX4 axis, iron homeostasis, mitochondria and other parallel pathways. In addition, microRNAs (miRNAs) have been implicated in modulating ferroptosis susceptibility through targeting different players involved in the execution or avoidance of ferroptosis. A growing body of evidence pinpoints the deregulation of miRNA-regulated ferroptosis as a critical factor in the development and progression of various pathophysiological conditions related to iron overload. The revelation of mechanisms of miRNA-dependent ferroptosis provides novel insights into the etiology of diseases and offers opportunities for therapeutic intervention. In this review, we discuss the interplay of emerging miRNA regulators and ferroptosis players under different pathological conditions, such as cancers, ischemia/reperfusion, neurodegenerative diseases, acute kidney injury and cardiomyopathy. We emphasize on the relevance of miRNA-regulated ferroptosis to disease progression and the targetability for therapeutic interventions.

Targeting epigenetic and posttranslational modifications regulating ferroptosis for the treatment of diseases

Ferroptosis, a unique modality of cell death with mechanistic and morphological differences from other cell death modes, plays a pivotal role in regulating tumorigenesis and offers a new opportunity for modulating anticancer drug resistance. Aberrant epigenetic modifications and posttranslational modifications (PTMs) promote anticancer drug resistance, cancer progression, and metastasis. Accumulating studies indicate that epigenetic modifications can transcriptionally and translationally determine cancer cell vulnerability to ferroptosis and that ferroptosis functions as a driver in nervous system diseases (NSDs), cardiovascular diseases (CVDs), liver diseases, lung diseases, and kidney diseases. In this review, we first summarize the core molecular mechanisms of ferroptosis. Then, the roles of epigenetic processes, including histone PTMs, DNA methylation, and noncoding RNA regulation and PTMs, such as phosphorylation, ubiquitination, SUMOylation, acetylation, methylation, and ADP-ribosylation, are concisely discussed. The roles of epigenetic modifications and PTMs in ferroptosis regulation in the genesis of diseases, including cancers, NSD, CVDs, liver diseases, lung diseases, and kidney diseases, as well as the application of epigenetic and PTM modulators in the therapy of these diseases, are then discussed in detail. Elucidating the mechanisms of ferroptosis regulation mediated by epigenetic modifications and PTMs in cancer and other diseases will facilitate the development of promising combination therapeutic regimens containing epigenetic or PTM-targeting agents and ferroptosis inducers that can be used to overcome chemotherapeutic resistance in cancer and could be used to prevent other diseases. In addition, these mechanisms highlight potential therapeutic approaches to overcome chemoresistance in cancer or halt the genesis of other diseases.

Acyl-CoA synthase ACSL4: an essential target in ferroptosis and fatty acid metabolism

ABSTRACT

Long-chain acyl-coenzyme A (CoA) synthase 4 (ACSL4) is an enzyme that esterifies CoA into specific polyunsaturated fatty acids, such as arachidonic acid and adrenic acid. Based on accumulated evidence, the ACSL4-catalyzed biosynthesis of arachidonoyl-CoA contributes to the execution of ferroptosis by triggering phospholipid peroxidation. Ferroptosis is a type of programmed cell death caused by iron-dependent peroxidation of lipids; ACSL4 and glutathione peroxidase 4 positively and negatively regulate ferroptosis, respectively. In addition, ACSL4 is an essential regulator of fatty acid (FA) metabolism. ACSL4 remodels the phospholipid composition of cell membranes, regulates steroidogenesis, and balances eicosanoid biosynthesis. In addition, ACSL4-mediated metabolic reprogramming and antitumor immunity have attracted much attention in cancer biology. Because it facilitates the cross-talk between ferroptosis and FA metabolism, ACSL4 is also a research hotspot in metabolic diseases and ischemia/reperfusion injuries. In this review, we focus on the structure, biological function, and unique role of ASCL4 in various human diseases. Finally, we propose that ACSL4 might be a potential therapeutic target.

LncRNA H19: a novel player in the regulation of diabetic kidney disease

Diabetic kidney disease (DKD), one of the most severe complications of diabetes mellitus (DM), has received considerable attention owing to its increasing prevalence and contribution to chronic kidney disease (CKD) and end-stage kidney disease (ESRD). However, the use of drugs targeting DKD remains limited. Recent data suggest that long non-coding RNAs (lncRNAs) play a vital role in the development of DKD. The lncRNA H19 is the first imprinted gene, which is expressed in the embryo and down-regulated at birth, and its role in tumors has long been a subject of controversy, however, in recent years, it has received increasing attention in kidney disease. The LncRNA H19 is engaged in the pathological progression of DKD, including glomerulosclerosis and tubulointerstitial fibrosis via the induction of inflammatory responses, apoptosis, ferroptosis, pyroptosis, autophagy, and oxidative damage. In this review, we highlight the most recent research on the molecular mechanism and regulatory forms of lncRNA H19 in DKD, including epigenetic, post-transcriptional, and post-translational regulation, providing a new predictive marker and therapeutic target for the management of DKD.

The ACSL4 Network Regulates Cell Death and Autophagy in Diseases

Lipid metabolism, cell death, and autophagy are interconnected processes in cells. Dysregulation of lipid metabolism can lead to cell death, such as via ferroptosis and apoptosis, while lipids also play a crucial role in the regulation of autophagosome formation. An increased autophagic response not only promotes cell survival but also causes cell death depending on the context, especially when selectively degrading antioxidant proteins or organelles that promote ferroptosis. ACSL4 is an enzyme that catalyzes the formation of long-chain acyl-CoA molecules, which are important intermediates in the biosynthesis of various types of lipids. ACSL4 is found in many tissues and is particularly abundant in the brain, liver, and adipose tissue. Dysregulation of ACSL4 is linked to a variety of diseases, including cancer, neurodegenerative disorders, cardiovascular disease, acute kidney injury, and metabolic disorders (such as obesity and non-alcoholic fatty liver disease). In this review, we introduce the structure, function, and regulation of ACSL4; discuss its role in apoptosis, ferroptosis, and autophagy; summarize its pathological function; and explore the potential implications of targeting ACSL4 in the treatment of various diseases.

Long non-coding RNAs in intracerebral hemorrhage

Intracerebral hemorrhage (ICH), a subtype of stroke, can lead to long-term disability and is one of the leading causes of death. Unfortunately, the effectiveness of pharmacological therapy for ICH is still uncertain. Long non-coding RNA (lncRNA) was defined as an RNA molecule that consists of more than 200 nt without translational activity. As a vital class of diverse molecules, lncRNAs are involved in developmental and pathological processes and have been attractive for decades. LncRNAs have also become potential targets for therapies, as they were massively identified and profiled. In particular, emerging evidence has revealed the critical role of lncRNAs in ICH while attempts were made to treat ICH via regulating lncRNAs. But the latest evidence remains to be summarized. Thus, in this review, we will summarize the recent advances in lncRNA in ICH, highlighting the regulatory role of lncRNAs and their potential as therapeutic targets.

LncRNA-PEAK1 promotes neuronal apoptosis after intracerebral hemorrhage by miR-466i-5p/caspase 8 axis

Background

At present, the treatment of intracerebral hemorrhage (ICH)-induced secondary brain injury (ISB) is limited, and the curative effect is not good. Long noncoding RNAs (lncRNAs) have been reported to play a role in ISB after ICH. We preliminarily monitored the induction effect of lncRNA-pseudopodium-enriched atypical kinase 1 (PEAK1) on neuronal cell apoptosis after ICH through our previous study and further experimental verification. However, the specific role and mechanism of lncRNA-PEAK1 in neuronal cell apoptosis after ICH have not been reported.

Methods

ICH cell models were established with hemin. Pro-inflammatory cytokines, cell proliferation, and apoptosis were evaluated by enzyme-linked immunosorbent assay, Cell Counting Kit-8 assay, flow cytometry, and terminal deoxynucleotidyl transferase dUTP nick end labeling, respectively. Moreover, lncRNA expression associated with apoptosis was confirmed by quantitative reverse transcription polymerase chain reaction (qRT-PCR). The biological functions of lncRNA-PEAK1, miR-466i-5p, and caspase8 were conducted in vitro. Further, we used bioinformatics, a dual-luciferase reporter assay, and rescue experiments to understand the mechanisms of competitive endogenous RNAs.

Results

qRT-PCR revealed that lncRNA-PEAK1 was markedly upregulated in ICH cell models. LncRNA-PEAK1 knockdown decreased the interleukin-1β and tumor necrosis factor-alpha levels, promoted cell proliferation, weakened cell apoptosis, and downregulated the key molecular protein levels involved in the cell apoptosis pathway. Bioinformatics analysis and dual-luciferase reporter assay revealed that lncRNA bound to miR-466i-5p, and caspase 8 was a target of miR-466i-5p. The mechanistic analysis demonstrated that lncRNA-PEAK1/miR-466i-5p promoted neuronal cell apoptosis by activating the apoptosis pathway through caspase8 after ICH.

Conclusion

Collectively, our investigation identified that the lncRNA-PEAK1/miR-446i-5p/caspase8 axis is closely related to neuronal cell apoptosis after ICH. Additionally, lncRNA-PEAK1 may be a potential target for ICH intervention.

β-Elemene enhances erlotinib sensitivity through induction of ferroptosis by upregulating lncRNA H19 in EGFR-mutant non-small cell lung cancer

Nearly half of all Asian non-small cell lung cancer (NSCLC) patients harbour epidermal growth factor receptor (EGFR) mutations, and first-generation EGFR tyrosine kinase inhibitors (TKIs) are one of the first-line treatments that have improved the outcomes of these patients. Unfortunately, 20% of these patients can not benefit from the treatment. The basis of this primary resistance is poorly understood. Therefore, overcoming EGFR-TKI primary resistance and maintaining the efficacy of TKIs has become a key issue. β-Elemene, a sesquiterpene compound extracted from Curcuma aromatica Salisb. (wenyujing), has shown potent antitumor effects. In this research, we found that β-elemene combined with erlotinib enhanced the cytotoxicity of erlotinib to primary EGFR-TKI-resistant NSCLC cells with EGFR mutations and that ferroptosis was involved in the antitumor effect of the combination treatment. We found that lncRNA H19 was significantly downregulated in primary EGFR-TKI-resistant NSCLC cell lines and was upregulated by the combination treatment. Overexpression or knockdown of H19 conferred sensitivity or resistance to erlotinib, respectively, in both in vitro and in vivo studies. The high level of H19 enhanced the cytotoxicity of erlotinib by inducing ferroptosis. In conclusion, our data showed that β-elemene combined with erlotinib could enhance sensitivity to EGFR-TKIs through induction of ferroptosis via H19 in primary EGFR-TKI-resistant lung cancer, providing a promising strategy to overcome EGFR-TKI resistance in NSCLC patients.

Inhibition of ox‐LDL‐induced endothelial cell injury by LINC02381 knockdown through the microRNA‐491‐5p/transcription factor 7 axis

Atherosclerosis (AS) is a complex multifactorial and chronic inflammatory vascular disease that contributes to the development of cardiovascular diseases. Abnormal cellular proliferation in human umbilical vein endothelial cells (HUVECs) is a crucial element in AS development. In this study, we investigated the potential role of the long noncoding RNA LINC02381/microRNA (miR)‐491‐5p/transcription factor 7 (TCF7) axis in regulating HUVEC injury in 30 participants suffering from AS and 30 healthy control participants. We established an in vitro model of AS in HUVECs using oxidized low‐density lipoprotein (ox‐LDL), and measured cellular mRNA and protein levels of LINC02381, miR‐491‐5p, and TCF7 in serum samples using reverse transcription‐quantitative polymerase chain reaction and Western blotting assays. We evaluated cell viability, apoptosis, and inflammation using Cell Counting Kit‐8, flow cytometry, and enzyme‐linked immunosorbent assays, respectively. Moreover, we analyzed apoptosis‐related protein expression using western blotting analysis and determined the association between miR‐491‐5p and LINC02381 or TCF7 using dual‐luciferase reporter assay, RNA pull‐down, and rescue experiments. We observed that LINC02381 was elevated, while miR‐491‐5p was downregulated in serum samples from participants with AS and in ox‐LDL‐treated HUVECs. LINC02381 knockdown was protective against HUVEC injury via miR‐491‐5p inhibition, which is its downstream target. Rescue experiments further demonstrated that miR‐491‐5p alleviated HUVEC injury by modulating TCF7. Thus, LINC02381 knockdown ameliorated HUVEC injury by regulating the miR‐491‐5p/TCF7 axis, which provides new insights into AS treatment strategies.

Epigenetic Regulation of Ferroptosis in Central Nervous System Diseases

Ferroptosis, a newly identified form of cell death, is characterized by iron overload and accumulation of lipid reactive oxygen species. Inactivation of pathways, such as glutathione/glutathione peroxidase 4, NAD(P)H/ferroptosis suppressor protein 1/ubiquinone, dihydroorotate dehydrogenase/ubiquinol, or guanosine triphosphate cyclohydrolase-1/6(R)-L-erythro-5,6,7,8-tetrahydrobiopterin pathways, have been found to induce ferroptosis. The accumulating data suggest that epigenetic regulation can determine cell sensitivity to ferroptosis at both the transcriptional and translational levels. While many of the effectors that regulate ferroptosis have been mapped, epigenetic regulation in ferroptosis is not yet fully understood. Neuronal ferroptosis is a driver in several central nervous system (CNS) diseases, such as stroke, Parkinson's disease, traumatic brain injury, and spinal cord injury, and thus, research on how to inhibit neuronal ferroptosis is required to develop novel therapies for these diseases. In this review, we have summarized epigenetic regulation of ferroptosis in these CNS diseases, focusing in particular on DNA methylation, non-coding RNA regulation, and histone modification. Understanding epigenetic regulation in ferroptosis will hasten the development of promising therapeutic strategies in CNS diseases associated with ferroptosis.

Elucidating the progress and impact of ferroptosis in hemorrhagic stroke

Hemorrhagic stroke is a devastating cerebrovascular disease with high morbidity and mortality, for which effective therapies are currently unavailable. Based on different bleeding sites, hemorrhagic stroke can be generally divided into intracerebral hemorrhage (ICH) and subarachnoid hemorrhage (SAH), whose pathogenesis share some similarity. Ferroptosis is a recently defined programmed cell deaths (PCDs), which is a critical supplement to the hypothesis on the mechanism of nervous system injury after hemorrhagic stroke. Ferroptosis is characterized by distinctive morphological changes of mitochondria and iron-dependent accumulation of lipid peroxides. Moreover, scientists have successfully demonstrated the involvement of ferroptosis in animal models of ICH and SAH, indicating that ferroptosis is a promising target for hemorrhagic stroke therapy. However, the studies on ferroptosis still faces a serious of technical and theoretical challenges. This review systematically elaborates the role of ferroptosis in the pathogenesis of hemorrhagic stroke and puts forward some opinions on the dilemma of ferroptosis research.

Emerging role of miRNAs in the regulation of ferroptosis

Ferroptosis is a kind of cell death which has distinctive features differentiating it from autophagy, necrosis and apoptosis. This iron-dependent form of cell death is described by an increase in lipid reactive oxygen species, shrinkage of mitochondria and decrease in mitochondrial cristae. Ferroptosis is involved in the initiation and progression of many diseases and is regarded as a hotspot of investigations on treatment of disorders. Recent studies have shown that microRNAs partake in the regulation of ferroptosis. The impact of microRNAs on this process has been verified in different cancers as well as intervertebral disc degeneration, acute myocardial infarction, vascular disease, intracerebral hemorrhage, preeclampsia, hemorrhagic stroke, atrial fibrillation, pulmonary fibrosis and atherosclerosis. miR-675, miR-93, miR-27a, miR-34a and miR-141 have been shown to affect iron metabolism, antioxidant metabolism and lipid metabolism, thus influencing all pivotal mechanisms in the ferroptosis process. In the current review, we summarize the role of microRNAs in ferroptosis and their involvement in the pathetiology of malignant and non-malignant disorders.

Protective effects of brain and muscle ARNT-like gene 1 on oxidized low-density lipoprotein-induced human brain microvascular endothelial cell injury by alleviating ferroptosis

Ferroptosis plays an important role in atherosclerotic cerebrovascular diseases. The brain and muscle ARNT-like gene 1 (BMAL1) is an important mediator in the progression of cerebrovascular diseases. However, whether BMAL1 regulates ferroptosis in atherosclerotic cerebrovascular diseases remains obscure. Here, human brain microvascular endothelial cells (HBMECs) were exposed to oxidized low-density lipoprotein (ox-LDL) to imitate cerebrovascular atherosclerosis. It was found that ox-LDL treatment induced ferroptosis events and reduced BMAL1 expression in HBMECs, which could be reversed by ferroptosis inhibitor ferrostatin-1. Furthermore, BMAL1 overexpression markedly mitigated ox-LDL-induced ferroptosis events and cell damage. Moreover, BMAL1 overexpression significantly promoted nuclear factor erythroid 2-related factor 2 (Nrf2) expression in HBMECs under ox-LDL conditions. And, Nrf2 silencing attenuated the protective effects of BMAL1 on ox-LDL-stimulated HBMEC damage and ferroptosis. Altogether, our findings delineate the cerebrovascular protective role of BMAL1/Nrf2 by antagonizing ferroptosis in response to ox-LDL stimulation and provide novel perspectives for therapeutic strategies for atherosclerotic cerebrovascular diseases.

mRNA and lncRNA co-expression network in mice of acute intracerebral hemorrhage

Background

Intracerebral hemorrhage (ICH) is a severe subtype of stroke lacking effective pharmacological targets. Long noncoding RNA (lncRNA) has been confirmed to participate in the pathophysiological progress of various neurological disorders. However, how lncRNA affects ICH outcomes in the acute phase is not completely clear. In this study, we aimed to reveal the relationship of lncRNA-miRNA-mRNA following ICH.

Method

We conducted the autologous blood injection ICH model and extracted total RNAs on day 7. Microarray scanning was used to obtain mRNA and lncRNA profiles, which were validated by RT-qPCR. GO/KEGG analysis of differentially expressed mRNAs was performed using the Metascape platform. We calculated the Pearson correlation coefficients (PCCs) of lncRNA-mRNA for co-expression network construction. A competitive endogenous (Ce-RNA) network was established based on DIANALncBase and miRDB database. Finally, the Ce-RNA network was visualized and analyzed by Cytoscape.

Results

In total, 570 differentially expressed mRNAs and 313 differentially expressed lncRNAs were identified (FC ≥ 2 and value of p <0.05). The function of differentially expressed mRNAs was mainly enriched in immune response, inflammation, apoptosis, ferroptosis, and other typical pathways. The lncRNA-mRNA co-expression network contained 57 nodes (21 lncRNAs and 36 mRNAs) and 38 lncRNA-mRNA pairs. The ce-RNA network was generated with 303 nodes (29 lncRNAs, 163 mRNAs, and 111 miRNAs) and 906 edges. Three hub clusters were selected to indicate the most significant lncRNA-miRNA-mRNA interactions.

Conclusion

Our study suggests that the top differentially expressed RNA molecules may be the biomarker of acute ICH. Furthermore, the hub lncRNA-mRNA pairs and lncRNA-miRNA-mRNA correlations may provide new clues for ICH treatment.

Ferroptosis and Iron Metabolism after Intracerebral Hemorrhage

The method of iron-dependent cell death known as ferroptosis is distinct from apoptosis. The suppression of ferroptosis after intracerebral hemorrhage (ICH) will effectively treat ICH and improve prognosis. This paper primarily summarizes the mechanism of ferroptosis after ICH, with an emphasis on lipid peroxidation, the antioxidant system, iron metabolism, and other pathways. In addition, regulatory targets and drug molecules were described. Although there has been some progress in the field of study, there are still numerous gaps. The mechanism by which non-heme iron enters neurons through the blood-brain barrier (BBB), the mitochondrial role in ferroptosis, and the specific mechanism by which lipid peroxidation induces ferroptosis remain unclear and require further study. In addition, the inhibitory effect of many drugs on ferroptosis after ICH has only been demonstrated in basic experiments and must be translated into clinical trials. In summary, research on ferroptosis following ICH will play an important role in the treatment of ICH.

An update on the therapeutic implications of long-chain acyl-coenzyme A synthetases in nervous system diseases

Long-chain acyl-coenzyme A synthetases (ACSLs) are a family of CoA synthetases that activate fatty acid (FA) with chain lengths of 12-20 carbon atoms by forming the acyl-AMP derivative in an isozyme-specific manner. This family mainly includes five members (ACSL1, ACSL3, ACSL4, ACSL5, and ACSL6), which are thought to have specific and different functions in FA metabolism and oxidative stress of mammals. Accumulating evidence shows that the dysfunction of ACSLs is likely to affect cell proliferation and lead to metabolic diseases in multiple organs and systems through different signaling pathways and molecular mechanisms. Hence, a central theme of this review is to emphasize the therapeutic implications of ACSLs in nervous system disorders.

Ferroptosis of Endothelial Cells in Vascular Diseases

Endothelial cells (ECs) line the inner surface of blood vessels and play a substantial role in vascular biology. Endothelial dysfunction (ED) is strongly correlated with the initiation and progression of many vascular diseases. Regulated cell death, such as ferroptosis, is one of the multiple mechanisms that lead to ED. Ferroptosis is an iron-dependent programmed cell death associated with various vascular diseases, such as cardiovascular, cerebrovascular, and pulmonary vascular diseases. This review summarized ferroptosis of ECs in vascular diseases and discussed potential therapeutic strategies for treating ferroptosis of ECs. In addition to lipid peroxidation inhibitors and iron chelators, a growing body of evidence showed that clinical drugs, natural products, and intervention of noncoding RNAs may also inhibit ferroptosis of ECs.

Integrated Analysis of a Ferroptosis-Related LncRNA Signature for Evaluating the Prognosis of Patients with Colorectal Cancer

LncRNAs have been well known for their multiple functions in the tumorigenesis, development, and relapse of colorectal cancer (CRC). Accumulating studies demonstrated that the expression of lncRNAs can be regulated by ferroptosis, a biological process that has been revealed to suppress CRC progression. However, the functions and clinical implications of ferroptosis-associated lncRNAs in CRC remain largely unknown. We, herein, aim to construct a prognostic signature with ferroptosis-related lncRNAs for the prognostic estimation of CRC patients. Firstly, we identified the lncRNAs related to ferroptosis based on the RNA-Seq data of CRC from the TCGA database. The univariate and multivariate Cox analyses were then performed to establish a prognostic signature composed of eight ferroptosis-related lncRNAs (AL161729.4, AC010973.2, CCDC144NL-AS1, AC009549.1, LINC01857, AP003555.1, AC099850.3, and AC008494.3). Furthermore, we divided the CRC patients into high- and low-risk groups based on the signature and found the overall survival (OS) of patients in the high-risk group was significantly shorter than that in the low-risk group (p = 3.31 × 10-11). Moreover, the patients in the high-risk groups had shorter recurrence-free survival (RFS) (p = 6.5 × 10-3) and disease-free survival (DFS) (p = 4.27 × 10-4), as well as higher tumor recurrence rate. Additionally, we found that the oncogenic pathways were enriched in the high-risk group, whereas the ferroptosis pathway that probably repressed CRC development was enriched in the low-risk group. In summary, our signature may provide a theoretical foundation for not only accurate judgment for prognosis but also evaluation for recurrence and metastasis in CRC patients.

A graphical journey through iron metabolism, microRNAs, and hypoxia in ferroptosis

Ferroptosis is an iron-dependent form of cell death, which is triggered by disturbed membrane integrity due to an overproduction of lipid peroxides. Induction of ferroptosis comprises several alterations, i.e. altered iron metabolism, response to oxidative stress, or lipid peroxide production. At the physiological level transcription, translation, and microRNAs add to the appearance and/or activity of building blocks that negatively or positively balance ferroptosis. Ferroptosis contributes to tissue damage in the case of, e.g., brain and heart injury but may be desirable to overcome chemotherapy resistance. For a more complete picture, it is crucial to also consider the cellular microenvironment, which during inflammation and in the tumor context is dominated by hypoxia. This graphical review visualizes basic mechanisms of ferroptosis, categorizes general inducers and inhibitors of ferroptosis, and puts a focus on microRNAs, iron homeostasis, and hypoxia as regulatory components.

Methyltransferase-like 3 silenced inhibited the ferroptosis development via regulating the glutathione peroxidase 4 levels in the intracerebral hemorrhage progression

This study examined the effects of methyltransferase-like 3 (METTL3) on ferroptosis during intracerebral hemorrhage (ICH) progression. The brain microvascular endothelial cells (BMVECs) were stimulated with oxygen and glucose deprivation (OGD) and hemin to establish an ICH model. Cell viability was tested using a CCK8 assay. The levels of Fe²⁺, glutathione, reactive oxygen species, LPO, and MDA were determined using the corresponding commercial kits. Cell death was analyzed using TUNEL and propidium iodide staining. The correlation between METTL3 and glutathione peroxidase 4 (GPX4) was analyzed using Spearman’s correlation test and further confirmed using the CHIP assay. Western blotting and RT-qPCR were performed to measure the relative expression levels. Mice were injected with 0.2 units collagenase IV to establish an ICH model in vivo. We found that the Fe²⁺, reactive oxygen species, LPO, and MDA levels were enhanced, and glutathione was depleted in OGD/H-treated BMVECs as well as in ICH mice. Additionally, cell viability and SLC7A11 protein levels decreased, and cell death and TFR1 protein levels increased in OGD/H-treated BMVECs. METTL3 silencing relieves OGD/H-induced injury in BMVECs. In addition, METTL3 was significantly negatively related to GPX4, which was further confirmed by the CHIP assay. Silencing of METTL3 decreased the N6-methyladenosine levels of GPX4 and increased its mRNA levels of GPX4. GPX4 knockdown neutralized the role of METTL3 in OGD/H-treated BMVECs. These results implied that ferroptosis occurred in the ODG/H-treated BMVECs and ICH mouse models. METTL3 silencing effectively suppressed ferroptosis by regulating N6-methyladenosine and mRNA levels of GPX4.

The role of ferroptosis in endothelial cell dysfunction

Ferroptosis is a form of iron-dependent cell death caused by an excessive accumulation of reactive oxygen species and lipid peroxidation. The importance of ferroptosis in the occurrence and progression of various diseases is gradually being recognized; however, the exact biological effects and potential mechanisms of endothelial cell ferroptosis remain unclear. The endothelium forms the innermost layer of the blood vessels and lymphatic vessels. It acts as an important functional interface, responds to various pathological stimuli and causes endothelial dysfunction. Here, we review recent findings to elucidate the role of ferroptosis in endothelial cells under different pathophysiologic settings.

Construction of a lncRNA-associated competing endogenous RNA regulatory network after traumatic brain injury in mouse

Traumatic brain injury (TBI) is a major public health problem worldwide which causes high mortality and disability. Functioning as microRNA (miRNA) sponges, long non-coding RNA (lncRNA) regulates the expression of protein-coding genes in a competing endogenous RNA (ceRNA) network. However, the lncRNA-associated ceRNA in TBI remains unclear. In this study, we processed the raw SRR files of mice cortex samples of sham injury (n = 3) and TBI groups (n = 3) to count files. Then, the expression profiles of lncRNAs and mRNAs were identified, and 86 differentially expressed (DE) lncRNAs and 1201 DEmRNAs between sham and TBI groups were identified. The DEmRNAs were used to perform enrichment analyses. Next, a lncRNA-miRNA-mRNA regulatory ceRNA network was constructed. The network consisted of 23 mRNAs, 5 miRNAs and 2 lncRNAs. The expression alternations of the 5 miRNAs were validated via qRT-PCR. The subnetwork of hub lncRNA Neat1 was extracted. We identified a potential inflammatory associated regulatory axis: Neat1/miR-31-5p/Myd88 axis. The PPI network based on DEmRNA involved in ceRNA network was constructed PPI networks to identify the hub genes. Finally, DElncRNAs and DEmRNAs were selected randomly and validated by qRT-PCR. In conclusion, with the lncRNA-miRNA-mRNA ceRNA network provided above, we can improve our understanding of the regulatory mechanisms and interaction among lncRNAs, miRNAs and mRNAs in TBI process.

Long Non Coding RNA Based Regulation of Cerebrovascular Endothelium

The rapid and high throughput discovery of long non coding RNAs (lncRNAs) has far outstripped the functional annotation of these novel transcripts in their respective cellular contexts. The cells of the blood brain barrier (BBB), especially the cerebrovascular endothelial cells (CVECs), are strictly regulated to maintain a controlled state of homeostasis for undisrupted brain function. Several key pathways are understood in CVEC function that lead to the development and maintenance of their barrier properties, the dysregulation of which leads to BBB breakdown and neuronal injury. Endothelial lncRNAs have been discovered and functionally validated in the past decade, spanning a wide variety of regulatory mechanisms in health and disease. We summarize here the lncRNA-mediated regulation of established pathways that maintain or disrupt the barrier property of CVECs, including in conditions such as ischemic stroke and glioma. These lncRNAs namely regulate the tight junction assembly/disassembly, angiogenesis, autophagy, apoptosis, and so on. The identification of these lncRNAs suggests a less understood mechanistic layer, calling for further studies in appropriate models of the blood brain barrier to shed light on the lncRNA-mediated regulation of CVEC function. Finally, we gather various approaches for validating lncRNAs in BBB function in human organoids and animal models and discuss the therapeutic potential of CVEC lncRNAs along with the current limitations.

Regulation of apoptosis, autophagy and ferroptosis by non‑coding RNAs in metastatic non‑small cell lung cancer (Review)

Non-small cell lung cancer (NSCLC), a common type of cancer worldwide, is normally associated with a poor prognosis. It is difficult to treat successfully as it often metastasizes into brain or bone. Methods to facilitate the induction of effective programmed cell death (PCD) in NSCLC cells to reverse drug resistance, or to inhibit the invasion and migration of NSCLC cells, are currently under investigation. The present study summarized the regulatory functions of PCD, including apoptosis, autophagy and ferroptosis, in the context of NSCLC metastasis. It further summarized how regulatory agents, including long non-coding RNAs, circular RNAs and microRNAs, regulate PCD during the metastasis of NSCLC and characterized new potential diagnostic biomarkers of NSCLC metastasis.

Regulation of Ferroptosis by Non-Coding RNAs in Head and Neck Cancers

Ferroptosis is a newly identified mode of programmed cell death characterized by iron-associated accumulation of lipid peroxides. Emerging research on ferroptosis has suggested its implication in tumorigenesis and stemness of cancer. On the other hand, non-coding RNAs have been shown to play a pivotal role in the modulation of various genes that affect the progression of cancer cells and ferroptosis. In this review, we summarize recent advances in the theoretical modeling of ferroptosis and its relationship between non-coding RNAs and head and neck cancers. Aside from the significance of ferroptosis-related non-coding RNAs in prognostic relevance, we also review how these non-coding RNAs participate in the regulation of iron, lipid metabolism, and reactive oxygen species accumulation. We aim to provide a thorough grounding in the function of ferroptosis-related non-coding RNAs based on current knowledge in an effort to develop effective therapeutic strategies for head and neck cancers.

Long non-coding RNA TTTY15 silencing inhibits gastric cancer progression by sponging microRNA-98-5p to down-regulate cyclin D2 expression

Gastric cancer is the most common malignant tumor in the digestive system. However, the detection rate of early gastric cancer is low, resulting in delayed prognosis and poor outcomes. The identification of effective therapeutic targets for gastric cancer is, therefore, of profound significance. Recently, various lncRNAs have been shown to be biomarkers for different cancers. This study investigated the role of long non-coding RNA (lncRNA) TTTY15 in gastric cancer. The expression level of TTTY15, miR-98-5p, and cyclin D2 (CCND2) were evaluated by quantitative reverse transcription polymerase chain reaction (qRT-PCR) and Western blot assay using tumor and non-tumor tissues collected from 30 patients with gastric cancer, gastric cancer cell lines (AGS, SNU-5, and NCI-N87), and the normal gastric epithelial cell line GES-1. The interaction between TTTY15 and miR-98-5p and between miR-98-5p and CCND2 were predicted by bioinformatics and then further verified by dual-luciferase and RNA pull-down analyses. Cell proliferation was evaluated by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl-2 H-tetrazolium bromide (MTT) assay, and apoptosis was measured using flow cytometry and caspase-3 assay. The results indicate that TTTY15 and CCND2 expression increased and miR-98-5p expression decreased in gastric cancer tumor tissues and cell lines. TTTY15 knockdown inhibited gastric cancer cell proliferation but promoted apoptosis by sponging miR-98-5p, which acted as a tumor suppressor gene by reducing the expression of its target gene CCND2 in gastric cancer. In conclusion, lncRNA TTTY15 is a potential oncogene involved in gastric cancer and may be a novel therapeutic target for gastric cancer treatment.

Circular RNA circCHFR downregulation protects against oxidized low-density lipoprotein-induced endothelial injury via regulation of microRNA-15b-5p/growth arrest and DNA damage inducible gamma

Atherosclerosis is the leading cause of coronary heart disease. In recent years, circ_0029589 (circCHFR) has been found to be associated with atherosclerosis development. However, the molecular mechanism of circCHFR action in atherosclerosis development is unknown. This study was aimed to investigate the function and action mechanism of circCHFR in atherosclerosis development. An atherosclerosis cell model was created by exposing human vascular endothelial cells (HUVECs) to oxidized low-density lipoprotein. The expression of circCHFR, microRNA(miR)-15b-5p, growth arrest and DNA damage inducible gamma (GADD45G), and their associated proteins was evaluated using quantitative reverse transcription-polymerase chain reaction and Western blotting. Additionally, cell viability, apoptosis, and cytokine levels were determined using Cell Counting Kit-8 (CCK8) assay, flow cytometry, and enzyme-linked immunosorbent assay, respectively. circCHFR expression was upregulated in patients with atherosclerosis and oxidized low-density lipoprotein (ox-LDL)-exposed HUVECs, whereas miR-15b-5p expression was downregulated. circCHFR silencing significantly improved viability and reduced apoptosis of HUVECs. In addition, the pro-apoptotic protein Bax and atherosclerosis-associated cytokines (interleukin-1β, interleukin-6, and tumor necrosis factor-α) were significantly downregulated, whereas the anti-apoptotic protein Bcl-2 was upregulated. Further, we discovered that circCHFR serves as a molecular sponge of miR-15b-5p. GADD45G was found to be an important target of miR-15b-5p; miR-15b-5p mimic inhibited GADD45G expression, reduced apoptosis and proinflammatory cytokine secretion, and improved cell survival. However, these effects of miR-15b-5p on (ox-LDL) induced HUVECs were reversed with GADD45G plasmid co-transfection. In conclusion, circCHFR promotes atherosclerosis progression via the miR-15b-5p/GADD45G axis and may be an important target for atherosclerosis treatment.

Targeting ferroptosis in acute kidney injury

Acute kidney injury (AKI) is a major public health problem with high incidence and mortality. As a form of programmed cell death (PCD), ferroptosis could be considered as a process of iron accumulation and enhanced lipid peroxidation. Recently, the fundamental roles of ferroptosis in AKI have attracted much attention. The network mechanism of ferroptosis in AKI and its roles in the AKI to chronic kidney disease (CKD) transition is complicated and multifactorial. Strategies targeting ferroptosis show great potential. Here, we review the research progress on ferroptosis and its participation in AKI. We hope that this work will provide clues for further studies of ferroptosis in AKI.

Knockdown of long non-coding RNA plasmacytoma variant translocation 1 relieves ox-LDL-induced endothelial cell injury through regulating microRNA-30c-5p in atherosclerosis

Atherosclerosis (AS) is a chronic inflammatory disease involving endothelial dysfunction, and is one of the main causes of death from cardiovascular disease (CVD). Long non-coding RNA plasmacytoma variant translocation 1 (lncRNA PVT1) is overexpressed in the serum of CVD patients. However, the mechanism by which lncRNA PVT1 functions in AS remains unknown. Our research was designed to probe interactions involving lncRNA PVT1 and oxidized low-density lipoprotein (ox-LDL)-stimulated endothelial cell injury in AS. lncRNA PVT1 expression in the serum of AS patients and ox-LDL-stimulated human umbilical vein endothelial cells (HUVECs) was detected using reverse transcriptase quantitative polymerase chain reaction (RT-qPCR). Cell counting kit (CCK)-8 assays, flow cytometry (FCM), and enzyme-linked immunosorbent assay (ELISA) were used to determine cell proliferation, apoptosis, and levels of inflammatory cytokines, respectively. Moreover, the correlation between lncRNA PVT1 and miR-30 c-5p was predicted and verified using StarBase3.0, TargetScan, and luciferase reporter-gene assays. lncRNA PVT1 was overexpressed in the serum of AS patients and in ox-LDL-stimulated HUVECs relative to controls. Knockdown of lncRNA PVT1 facilitated proliferation, reduced apoptosis, and secretion of inflammatory factors in ox-LDL-treated HUVECs. Moreover, miR-30 c-5p was verified as a direct target of lncRNA PVT1. Furthermore, we observed that miR-30 c-5p expression was lower in AS patients than in controls. In addition, the influence of lncRNA PVT1 knockdown on ox-LDL-treated HUVECs was significantly reversed by downregulation of miR-30 c-5p. In conclusion, lncRNA PVT1 silencing inhibited HUVEC damage stimulated by ox-LDL via miR-30 c-5p regulation.

lncRNA H19 Aggravates Brain Injury in Rats following Experimental Intracerebral Hemorrhage via NF-κB Pathway

OBJECTIVE

To explore the effect of long noncoding RNA H19 (lncRNA H19) on brain injury in rats following experimental intracerebral hemorrhage (ICH).

METHODS

Rat ICH model was established with type IV collagenase. The neurological function scores were evaluated, and the water content in brain tissue was measured. The nerve injury indexes, inflammatory factors, and oxidative stress indexes were also measured. Moreover, the expression of lncRNA H19 was determined by qRT-PCR, and Western blot detected NF-κB pathway-related protein expression.

RESULTS

Compared with the sham group, the neurological function scores, the water content in brain tissue, and levels of injury indicators myelin basic protein (MBP), S-100B, and neuron-specific enolase (NSE) in the ICH rats were significantly increased. Meanwhile, the levels of TNF-α, IL-6, IL-1β, ROS, and MDA were significantly increased, but the levels of SOD were significantly decreased. In addition, the expression of lncRNA H19 in the brain tissue in the ICH group was significantly higher than that in the sham group. After further interference with lncRNA H19 expression (sh-H19 group), the levels of all the above indicators were reversed and the neurological damage was improved. Western blot results showed that the expression of NF-κBp65 and IKKβ was significantly higher, and IκBα expression was lower in the perivascular hematoma tissue in the ICH group compared with the sham group. Compared with the sh-NC group, NF-κBp65 and IKKβ expression were significantly lower and IκBα was significantly higher in the sh-H19 group.

CONCLUSION

lncRNA H19 exacerbated brain injury in rats with ICH by promoting neurological impairment, brain edema, and releasing inflammatory responses and oxidative stress. This may be related to the activation of NF-κB signaling pathway.

MicroRNA miR-27b-3p regulate microglial inflammation response and cell apoptosis by inhibiting A20 (TNF-α-induced protein 3)

Inflammatory reaction exerts a pivotal role in secondary damage after cerebral hemorrhage and spinal cord injury. miRNAs can both promote and inhibit inflammatory actions among microglial cells. The objective of the present paper was to figure out whether miR-27b-3p produced regulatory effects during processes of microglial inflammation. Lipopolysaccharides (LPS) were used to prepare microglial activation models. Following miR-27b-3p overexpression and interference, the RNA and protein levels of tumor necrosis factor (TNF)-α, interleukin (IL)-6, and IL-1β were subjected to real-time fluorescent quantitative PCR (qPCR) and western blot assays, respectively. Cellular apoptosis was subjected to flow cytometry and miR-27b-3p target genes were visualized using a dual luciferase reporter system for verification. The levels of TNF-α, IL-6, and IL-1β mRNA in miR-27b-3p-overexpressed microglial cells were markedly increased compared to the control. Apoptosis of microglial cells was increased markedly in the overexpressed miR-27b-3p group compared to the negative control. Conversely, a different result was presented in the microglial transfected with miR-27b-3p inhibitors. The downregulation of A20, a miR-27b-3p target gene, mediated levels of TNF-α, IL-6, and IL-1β. Furthermore, A20 reduced microglial apoptosis. These data revealed that miR-27b-3p could mediate not only microglia activation but also neuroinflammation via downregulating A20 expression. Thus, miR-27b-3p is regarded as gene therapy in treating cerebral hemorrhage and spinal cord injury.

Identification of novel biomarkers for intracerebral hemorrhage via long noncoding RNA-associated competing endogenous RNA network

Intracerebral hemorrhage (ICH) is a leading cause of death and disability worldwide. This study aimed to examine the involvement of long non-coding RNAs (lncRNAs), a group of non-coding transcripts, in ICH as potential biomarkers. An expression profile of patients with ICH using four contralateral grey matter controls (GM) and four contralateral white matter controls (WM) was downloaded from the Gene Expression Omnibus (GEO) database. Co-expressed lncRNAs and mRNAs were selected to create competing endogenous RNA (ceRNA) networks. Key lncRNAs were identified in ceRNA networks, which were validated through Real-time qPCR (RT-qPCR) with peripheral blood samples from patients with ICH. A total of 49 differentially expressed lncRNAs were discovered in different brain regions. The ceRNA network in GM included 9 lncRNAs, 40 mRNAs, and 20 microRNAs (miRNAs), while the one in WM covered 6 lncRNAs, 25 mRNAs, and 14 miRNAs. Six hub lncRNAs were observed and RT-qPCR results showed that LY86-AS1, DLX6-AS1, RRN3P2, and CRNDE were down-regulated, while HCP5 and MIAT were up-regulated in patients with ICH. Receiver Operating Characteristic (ROC) assessments demonstrated the diagnostic value of these lncRNAs. Our findings highlight the potential roles of lncRNA in ICH pathogenesis. Moreover, the hub lncRNAs discovered here might become novel biomarkers and promising targets for ICH drug development.