LncRNA NKILA regulates endothelium inflammation by controlling a NF-κB/KLF4 positive feedback loop

Epigenetic and epitranscriptomic role of lncRNA in carcinogenesis (Review)

Long non‑coding RNAs (lncRNAs) are key players in the regulation of gene expression by mediating epigenetic and epitranscriptomic modification. Dysregulation of lncRNAs is implicated in tumor initiation, progression and metastasis. lncRNAs modulate chromatin structure and gene transcription by recruiting epigenetic regulators, including DNA‑ or histone‑modifying enzymes. Additionally, lncRNAs mediate chromatin remodeling and enhancer‑promoter long‑range chromatin interactions to control oncogene expression by recruiting chromatin organization‑associated proteins, thereby promoting carcinogenesis. Furthermore, lncRNAs aberrantly induce oncogene expression by mediating epitranscriptomic modifications, including RNA methylation and RNA editing. The present study aimed to summarize the regulatory mechanisms of lncRNAs in cancer to unravel the complex interplay between lncRNAs and epigenetic/epitranscriptomic regulators in carcinogenesis. The present review aimed to provide a novel perspective on the epigenetic and epitranscriptomic roles of lncRNAs in carcinogenesis to facilitate identification of potential biomarkers and therapeutic targets for cancer diagnosis and treatment.

Phosphorylation of FOXN3 by NEK6 promotes pulmonary fibrosis through Smad signaling

The transcriptional repressor FOXN3 plays a key role in regulating pulmonary inflammatory responses, which are crucial in the development of pulmonary fibrosis. However, its specific regulatory function in lung fibrosis remains unclear. Here, we show that FOXN3 suppresses pulmonary fibrosis by inhibiting Smad transcriptional activity. FOXN3 targets a substantial number of Smad response gene promoters, facilitating Smad4 ubiquitination, which disrupts the association of the Smad2/3/4 complex with chromatin and abolishes its transcriptional response. In response to pro-fibrotic stimuli, NEK6 phosphorylates FOXN3 at S412 and S416, leading to its degradation. The loss of FOXN3 inhibits β-TrCP-mediated ubiquitination of Smad4, stabilizing the Smad complex's association with its responsive elements and promoting transcriptional activation, thus contributing to the development of pulmonary fibrosis. Notably, we found a significant inverse expression pattern between FOXN3 and Smad4 in clinical pulmonary fibrosis cases, underscoring the importance of the NEK6-FOXN3-Smad axis in the pathological process of pulmonary fibrosis.

Biological functions and affected signaling pathways by Long Non-Coding RNAs in the immune system

Recently, the various regulative functions of long non-coding RNAs (LncRNAs) have been well determined. Recently, the vital role of LncRNAs as gene regulators has been identified in the immune system, especially in the inflammatory response. All cells of the immune system are governed by a complex and ever-changing gene expression program that is regulated through both transcriptional and post-transcriptional processes. LncRNAs regulate gene expression within the cell nucleus by influencing transcription or through post-transcriptional processes that affect the splicing, stability, or translation of messenger RNAs (mRNAs). Recent studies in immunology have revealed substantial alterations in the expression of lncRNAs during the activation of the innate immune system as well as the development, differentiation, and activation of T cells. These lncRNAs regulate key aspects of immune function, including the manufacturing of inflammatory molecules, cellular distinction, and cell movement. They do this by modulating protein-protein interactions or through base pairing with RNA and DNA. Here we review the current understanding of the mechanism of action of lncRNAs as novel immune-related regulators and their impact on physiological and pathological processes related to the immune system, including autoimmune diseases. We also highlight the emerging pattern of gene expression control in important research areas at the intersection between immunology and lncRNA biology.

LncRNAs Are Key Regulators of Transcription Factor-Mediated Endothelial Stress Responses

The functional role of long noncoding RNAs in the endothelium is highly diverse. Among their many functions, regulation of transcription factor activity and abundance is one of the most relevant. This review summarizes the recent progress in the research on the lncRNA-transcription factor axes and their implications for the vascular endothelium under physiological and pathological conditions. The focus is on transcription factors critical for the endothelial response to external stressors, such as hypoxia, inflammation, and shear stress, and their lncRNA interactors. These regulatory interactions will be exemplified by a selected number of lncRNAs that have been identified in the endothelium under physiological and pathological conditions that are influencing the activity or protein stability of important transcription factors. Thus, lncRNAs can add a layer of cell type-specific function to transcription factors. Understanding the interaction of lncRNAs with transcription factors will contribute to elucidating cardiovascular disease pathologies and the development of novel therapeutic approaches.

A review of KLF4 and inflammatory disease: Current status and future perspective

Inflammation is the response of the human body to injury, infection, or other abnormal states, which is involved in the development of many diseases. As a member of the Krüppel-like transcription factors (KLFs) family, KLF4 plays a crucial regulatory role in physiological and pathological processes due to its unique dual domain of transcriptional activation and inhibition. A growing body of evidence has demonstrated that KLF4 plays a pivotal role in the pathogenesis of various inflammatory disorders, including inflammatory bowel disease, osteoarthritis, renal inflammation, pneumonia, neuroinflammation, and so on. Consequently, KLF4 has emerged as a promising new therapeutic target for inflammatory diseases. This review systematically generalizes the molecular regulatory network, specific functions, and mechanisms of KLF4 to elucidate its complex roles in inflammatory diseases. An in-depth study on the biological function of KLF4 is anticipated to offer a novel research perspective and potential intervention strategies for inflammatory diseases.

Exploring potential roles of long non-coding RNAs in cancer immunotherapy: a comprehensive review

Cancer treatment has long been fraught with challenges, including drug resistance, metastasis, and recurrence, making it one of the most difficult diseases to treat effectively. Traditional therapeutic approaches often fall short due to their inability to target cancer stem cells and the complex genetic and epigenetic landscape of tumors. In recent years, cancer immunotherapy has revolutionized the field, offering new hope and viable alternatives to conventional treatments. A particularly promising area of research focuses on non-coding RNAs (ncRNAs), especially long non-coding RNAs (lncRNAs), and their role in cancer resistance and the modulation of signaling pathways. To address these challenges, we performed a comprehensive review of recent studies on lncRNAs and their impact on cancer immunotherapy. Our review highlights the crucial roles that lncRNAs play in affecting both innate and adaptive immunity, thereby influencing the outcomes of cancer treatments. Key observations from our review indicate that lncRNAs can modify the tumor immune microenvironment, enhance immune cell infiltration, and regulate cytokine production, all of which contribute to tumor growth and resistance to therapies. These insights suggest that lncRNAs could serve as potential targets for precision medicine, opening up new avenues for developing more effective cancer immunotherapies. By compiling recent research on lncRNAs across various cancers, this review aims to shed light on their mechanisms within the tumor immune microenvironment.

Effect of Priming With Toll-Like Receptor 3 Agonist on Expression of Long Noncoding RNAs in Human Wharton Jelly Mesenchymal Stem Cells

OBJECTIVES

Mesenchymal stem cells are gaining attention in medicine because of their anti-inflammatory and immunosuppressive properties. Inflammatory conditions can modulate immune responses in mesenchymal stem cells.We investigated the expression of long noncoding RNAs (RMRP, MALT1, NKILA,THRIL, and Linc-MAF-4) in humanWharton jelly mesenchymal stem cells primed with polyinosinicpolycytidylic acid.

MATERIALS AND METHODS

Mesenchymal stem cells were isolated from human Wharton jelly by the explant method. To determine the stem nature of the cells, we performed a differentiation test on bone and fat cells. We used flow cytometry analysis to determine surface markers. Umbilical cord mesenchymal stem cells (1 × 105) were cultured in T75 culture flasks in Dulbecco's modified Eagle medium containing 10% fetal bovine serum. After cells reached approximately 80% confluency, cells were exposed to 50 µg/mL of polyinosinic-polycytidylic acid, a Toll-like receptor 3 ligand, for 24, 48, and 72 hours. The control group were cells not exposed to polyinosinic-polycytidylic acid. Real-time polymerase chain reaction evaluated RMRP, MALAT1, NKILA, THRIL, and Linc-MAF-4 long noncoding RNAs.

RESULTS

We observed significantly increased expression of NKILA inWharton jelly mesenchymal stem cells stimulated with polyinosinic-polycytidylic acid at 72 hours compared with expression level in the control group (P < .001).

CONCLUSIONS

Results indicated that a potential mechanism by which the Toll-like receptor 3 ligand improves immunosuppression of mesenchymal stem cells can be attributed to the regulatory role of long noncoding RNAs, possibly through increased expression of anti-inflammatory long noncoding RNAs such as NKILA.

Insights into the defensive roles of lncRNAs during Mycoplasma pneumoniae infection

Mycoplasma pneumoniae causes respiratory tract infections, affecting both children and adults, with varying degrees of severity ranging from mild to life-threatening. In recent years, a new class of regulatory RNAs called long non-coding RNAs (lncRNAs) has been discovered to play crucial roles in regulating gene expression in the host. Research on lncRNAs has greatly expanded our understanding of cellular functions involving RNAs, and it has significantly increased the range of functions of lncRNAs. In lung cancer, transcripts associated with lncRNAs have been identified as regulators of airway and lung inflammation in a process involving protein complexes. An excessive immune response and antibacterial immunity are closely linked to the pathogenesis of M. pneumoniae. The relationship between lncRNAs and M. pneumoniae infection largely involves lncRNAs that participate in antibacterial immunity. This comprehensive review aimed to examine the dysregulation of lncRNAs during M. pneumoniae infection, highlighting the latest advancements in our understanding of the biological functions and molecular mechanisms of lncRNAs in the context of M. pneumoniae infection and indicating avenues for investigating lncRNAs-related therapeutic targets.

GOLM1 Promotes Pulmonary Fibrosis through Upregulation of NEAT1

Idiopathic pulmonary fibrosis (IPF) is a lethal progressive disease with elusive molecular mechanisms and limited therapeutic options. Aberrant activation of fibroblasts is a central hallmark of lung fibrosis. Here, we report that Golgi membrane protein 1 (GOLM1, also known as GP73 or GOLPH2) was increased in the lungs of patients with pulmonary fibrosis and mice with bleomycin (BLM)-induced pulmonary fibrosis. Loss of GOLM1 inhibited proliferation, differentiation, and extracellular matrix deposition of fibroblasts, whereas overexpression of GOLM1 exerted the opposite effects. Similarly, worsening pulmonary fibrosis after BLM treatment was observed in GOLM1-knock-in mice, whereas BLM-treated Golm1-knockout mice exhibited alleviated pulmonary fibrosis and collagen deposition. Furthermore, we identified long noncoding RNA NEAT1 downstream of GOLM1 as a potential mediator of pulmonary fibrosis through increased GOLM1 expression. Depletion of NEAT1 inhibited fibroblast proliferation and extracellular matrix production and reversed the profibrotic effects of GOLM1 overexpression. Additionally, we identified KLF4 as a downstream mediator of GOLM1 signaling to NEAT1. Our findings suggest that GOLM1 plays a pivotal role in promoting pulmonary fibrosis through the GOLM1-KLF4-NEAT1 signaling axis. Targeting GOLM1 and its downstream pathways may represent a novel therapeutic strategy for treating pulmonary fibrosis.

Noncoding RNA as an influential epigenetic modulator with promising roles in cancer therapeutics

The epigenetic landscape has an important role in cellular homeostasis and its deregulation leads to cancer. Noncoding (nc)RNA networks function as major regulators of cellular epigenetic hallmarks via regulation of vital processes, such as histone modification and DNA methylation. They are integral intracellular components affecting multiple oncogenic pathways. Thus, it is important to elucidate the effects of ncRNA networks on epigenetic programming that lead to the initiation and progression of cancer. In this review, we summarize the effects of epigenetic modification influenced by ncRNA networks and crosstalk between diverse classes of ncRNA, which could aid the development of patient-specific cancer therapeutics targeting ncRNAs, thereby altering cellular epigenetics.

Extracellular vesicle-transmitted miR-671-5p alleviates lung inflammation and injury by regulating the AAK1/NF-κB axis

Mesenchymal stem cells regulate remote intercellular signaling communication via their secreted extracellular vesicles. Here, we report that menstrual blood-derived stem cells alleviate acute lung inflammation and injury via their extracellular vesicle-transmitted miR-671-5p. Disruption of this abundantly expressed miR-671-5p dramatically reduced the ameliorative effect of extracellular vesicles released by menstrual blood-derived stem cells on lipopolysaccharide (LPS)-induced pulmonary inflammatory injury. Mechanistically, miR-671-5p directly targets the kinase AAK1 for post-transcriptional degradation. AAK1 is found to positively regulate the activation of nuclear factor κB (NF-κB) signaling by controlling the stability of the inhibitory protein IκBα. This study identifies a potential molecular basis of how extracellular vesicles derived from mesenchymal stem cells improve pulmonary inflammatory injury and highlights the functional importance of the miR-671-5p/AAK1 axis in the progression of pulmonary inflammatory diseases. More importantly, this study provides a promising cell-based approach for the treatment of pulmonary inflammatory disorders through an extracellular vesicle-dependent pathway.

ANRIL overexpression globally induces expression and alternative splicing of genes involved in inflammation in HUVECs

Long non‑coding (lnc)RNAs serve important cellular functions and certain lncRNAs have roles in different mechanisms of gene regulation. lncRNA‑antisense non‑coding RNA in the INK4 locus (ANRIL) affects cell inflammation; however, the potential genes underlying the inflammatory response regulated by ANRIL remain unclear. In the present study, the potential function of ANRIL in regulating gene expression and alternative splicing was assessed. ANRIL‑regulated human umbilical vein endothelial cell (HUVEC) transcriptome was obtained using high‑throughput RNA sequencing (RNA‑seq) to evaluate the potential role of ANRIL. Following plasmid transfection, gene expression profile and alternative splicing pattern of HUVECs overexpressing ANRIL were analyzed using RNA‑seq. ANRIL overexpression affected the transcription levels of genes associated with the inflammatory response, NF‑κB signaling pathway, type I interferon‑mediated signal transduction pathway and innate immune response. ANRIL regulated the alternative splicing of hundreds of genes with functions such as gene expression, translation, DNA repair, RNA processing and participation in the NF‑κB signaling pathway. Many of these genes serve a key role in the inflammatory response. ANRIL‑regulated inflammatory response may be achieved by regulating alternate splicing and transcription. The present study broadened the understanding of ANRIL‑mediated gene regulation mechanisms and clarified the role of ANRIL in mediating inflammatory response mechanisms.

Insights into the role of long non-coding RNAs in DNA methylation mediated transcriptional regulation

DNA methylation is one of the most important epigenetic mechanisms that governing regulation of gene expression, aberrant DNA methylation patterns are strongly associated with human malignancies. Long non-coding RNAs (lncRNAs) have being discovered as a significant regulator on gene expression at the epigenetic level. Emerging evidences have indicated the intricate regulatory effects between lncRNAs and DNA methylation. On one hand, transcription of lncRNAs are controlled by the promoter methylation, which is similar to protein coding genes, on the other hand, lncRNA could interact with enzymes involved in DNA methylation to affect the methylation pattern of downstream genes, thus regulating their expression. In addition, circular RNAs (circRNAs) being an important class of noncoding RNA are also found to participate in this complex regulatory network. In this review, we summarize recent research progress on this crosstalk between lncRNA, circRNA, and DNA methylation as well as their potential functions in complex diseases including cancer. This work reveals a hidden layer for gene transcriptional regulation and enhances our understanding for epigenetics regarding detailed mechanisms on lncRNA regulatory function in human cancers.

Unveiling the Vital Role of Long Non-Coding RNAs in Cardiac Oxidative Stress, Cell Death, and Fibrosis in Diabetic Cardiomyopathy

Diabetes mellitus is a burdensome public health problem. Diabetic cardiomyopathy (DCM) is a major cause of mortality and morbidity in diabetes patients. The pathogenesis of DCM is multifactorial and involves metabolic abnormalities, the accumulation of advanced glycation end products, myocardial cell death, oxidative stress, inflammation, microangiopathy, and cardiac fibrosis. Evidence suggests that various types of cardiomyocyte death act simultaneously as terminal pathways in DCM. Long non-coding RNAs (lncRNAs) are a class of RNA transcripts with lengths greater than 200 nucleotides and no apparent coding potential. Emerging studies have shown the critical role of lncRNAs in the pathogenesis of DCM, along with the development of molecular biology technologies. Therefore, we summarize specific lncRNAs that mainly regulate multiple modes of cardiomyopathy death, oxidative stress, and cardiac fibrosis and provide valuable insights into diagnostic and therapeutic biomarkers and strategies for DCM.

L-Glutamine alleviates osteoarthritis by regulating lncRNA-NKILA expression through the TGF-β1/SMAD2/3 signalling pathway

Osteoarthritis (OA) is a heterogeneous condition characterized by cartilage degradation, subchondral sclerosis, and osteophyte formation, and accompanied by the generation of pro-inflammatory mediators and degradation of extracellular matrix. The current treatment for early OA is focused on the relief of symptoms, such as pain, but this treatment cannot delay the pathological process. L-Glutamine (L-Gln), which has anti-inflammatory and anti-apoptotic effects, is the most abundant amino acid in human blood. However, its role in OA has not been systematically studied. Therefore, the objective of this work was to explore the therapeutic effect and molecular mechanism of L-Gln on OA. In vitro, we found that L-Gln could up-regulate the expression of the long non-coding RNA NKILA, which is regulated by the transforming growth factor-β1/SMAD2/3 pathway, and inhibit the activity of nuclear factor-κB, thereby decreasing the expression of nitric oxide synthase, cyclooxygenase-2, and matrix metalloproteinase-13 (MMP-13). This led to a reduction in the generation of nitrous oxide, prostaglandin E-2, tumour necrosis factor-α, and degradation of the extracellular matrix (i.e. aggrecan and collagen II) in rat OA chondrocytes. Moreover, intragastric administration of L-Gln reduced the degradation of cartilage tissue and expression of MMP-13 in a rat OA model. L-Gln also relieved the clinical symptoms in some patients with early knee joint OA. These findings highlight that L-Gln is a potential therapeutic drug to delay the occurrence and development of OA.

Epigenetics-mediated pathological alternations and their potential in antiphospholipid syndrome diagnosis and therapy

APS (antiphospholipid syndrome) is a systematic autoimmune disease accompanied with venous or arterial thrombosis and poor pregnant manifestations, partly attributing to the successive elevated aPL (antiphospholipid antibodies) and provoked prothrombotic and proinflammatory molecules production. Nowadays, most researches focus on the laboratory detection and clinic features of APS, but its precise etiology remains to be deeply explored. As we all know, the dysfunction of ECs (endothelial cells), monocytes, platelets, trophoblasts and neutrophils are key contributors to APS progression. Especially, their epigenetic variations, mainly including the promoter CpGs methylation, histone PTMs (post-translational modifications) and ncRNAs (noncoding RNAs), result in genes expression or silence engaged in inflammation initiation, thrombosis formation, autoimmune activation and APOs (adverse pregnancy outcomes) in APS. Given the potential of epigenetic markers serving as diagnostic biomarkers or therapeutic targets of APS, and the encouraging advancements in epigenetic drugs are being made. In this review, we would systematically introduce the epigenetic underlying mechanisms for APS progression, comprehensively elucidate the functional mechanisms of epigenetics in boosting ECs, monocytes, platelets, trophoblasts and neutrophils. Lastly, the application of epigenetic alterations for probing novel diagnostic, specific therapeutic and prognostic strategies would be proposed.

Expression analysis of inflammatory response-associated genes in coronary artery disease

BACKGROUND

Coronary artery disease (CAD) is among prominent causes of death throughout the world. Inflammatory processes participate in the pathogenesis of this disorder.

METHODS

In the current case-control study, we compared expression levels of three inflammation-associated genes namely Antisense noncoding RNA in the INK4 locus (ANRIL), NKILA and IL-1B between CAD patients and matched healthy subjects.

RESULTS

ANRIL, IL-1B and NKILA were significantly down-regulated in CAD patients compared with controls (p values of <.0001, .023 and <.0001, respectively). When evaluating study participants based on their gender, the differences in expression levels of ANRIL and NKILA were significant in both male and female patients compared with the matched controls. However, IL-1B was only down-regulated in female patients compared with female controls.

CONCLUSION

Taken together, our study revealed dysregulation of inflammation-associated genes in the peripheral blood of CAD patients and supported the previously suggested role of inflammation in the pathogenesis of CAD.

A Review of the Mechanism of Vascular Endothelial Injury in Immunoglobulin A Vasculitis

Immunoglobulin A (IgA) vasculitis (IgAV), also known as Henoch-Schönlein purpura, is the most common form of childhood vasculitis. It is characterized by cutaneous hemorrhage, resulting from red blood cell leakage into the skin or mucosae, possibly caused by damage to small blood vessels. These acute symptoms usually disappear without treatment. Endothelial cells are distributed on the inner surfaces of blood vessels and lymphatic vessels, and have important functions in metabolism and endocrine function, as well as being the primary targets of external stimuli and endogenous immune activity. Injury to endothelial cells is a feature of IgA vasculitis. Endothelial cell damage may be related to the deposition of immune complexes, the activation of complement, inflammatory factors, and chemokines, oxidative stress, hemodynamics, and coagulation factors. Both epigenetic mechanisms and genetic diversity provide a genetic background for endothelial cell injury. Here, research on the role of endothelial cells in allergic IgA vasculitis is reviewed.

LncRNA-mediated DNA methylation: an emerging mechanism in cancer and beyond

DNA methylation is one of the most important epigenetic mechanisms to regulate gene expression, which is highly dynamic during development and specifically maintained in somatic cells. Aberrant DNA methylation patterns are strongly associated with human diseases including cancer. How are the cell-specific DNA methylation patterns established or disturbed is a pivotal question in developmental biology and cancer epigenetics. Currently, compelling evidence has emerged that long non-coding RNA (lncRNA) mediates DNA methylation in both physiological and pathological conditions. In this review, we provide an overview of the current understanding of lncRNA-mediated DNA methylation, with emphasis on the roles of this mechanism in cancer, which to the best of our knowledge, has not been systematically summarized. In addition, we also discuss the potential clinical applications of this mechanism in RNA-targeting drug development.

Long non-coding RNA CHRF accelerates LPS-induced acute lung injury through microRNA-146a/Notch1 axis

Background

The present study sought to investigate the regulatory role of the long non-coding RNA (lncRNA) cardiac hypertrophy-related factor (CHRF) in a mouse model of acute lung injury (ALI) and in primary mouse pulmonary microvascular endothelial cells (MPVECs) treated with lipopolysaccharide (LPS).

Methods

C57BL/6 mice were given adenovirus (Ad) sh-CHRF or negative control (NC) before undergoing cecal ligation and perforation. MPVECs transfected with Adsh-CHRF or NC were treated with LPS. Double luciferase assay was used to detect the binding of miR-146a to CHRF or Notch1. Subsequently, MPVECs were co-transfected with miR-146a inhibitor and sh-CHRF for 24 hours, and then treated with LPS.

Results

High expression of CHRF was detected in septic mice. Cecal ligation and perforation induced ALI and apoptosis in mice, whereas, CHRF knockout could inhibit ALI. The protein expression levels of TNF-α, IL-1β and IL-6 in the lung and bronchoalveolar lavage fluid of the CLP group were up-regulated, whereas the expression of IL-4 and IL-10 was down-regulated. CHRF inhibition reduced the production of proinflammatory cytokines in septic mice. The inhibitory effect of CHRF gene knockdown on lung inflammation and apoptosis was confirmed in the septic cell model. Mechanistic investigation showed that CHRF up-regulated the level of Notch1 by sponging miR-146a. Additionally, the low expression of miR-146a reversed the inhibitory effect of CHRF gene knockout on LPS-induced inflammatory response and apoptosis. Together, in vivo and in vitro results demonstrated that CHRF enhanced sepsis-induced ALI by targeting miR-146a and up-regulating Notch1.

Conclusions

CHRF can induce inflammation and apoptosis caused by sepsis by miR-146a/Notch1 axis. Therefore, it may serve as a potential drug target for treating sepsis-induced ALI.

Coordination of PRKCA/PRKCA-AS1 interplay facilitates DNA methyltransferase 1 recruitment on DNA methylation to affect protein kinase C alpha transcription in mitral valve of rheumatic heart disease

In the present study, mitral valve tissues from three mitral stenosis patients with RHD by valve replacement and two healthy donors were harvested and conducted DNA methylation signature on PRKCA by MeDIP-qPCR. The presence of hypomethylated CpG islands at promoter and 5' terminal of PRKCA was observed in RHD accompanied with highly expressed PRKCA and down-regulated antisense long non-coding RNA (lncRNA) PRKCA-AS1 compared to health control. Furthermore, the enrichments of DNMT1/3A/3B on PRKCA were detected by ChIP-qPCR assay in vivo and in human cardiomyocyte AC16 and RL-14 cells exposed to TNF-α in vitro, and both demonstrated that DNMT1 substantially contributed to DNA methylation. Additionally, PRKCA-AS1 was further determined to bind with promoter of PRKCA via 5' terminal and interact with DNMT1 via 3' terminal. Taken together, our results illuminated a novel regulatory mechanism of DNA methylation on regulating PRKCA transcription through lncRNA PRKCA-AS1, and shed light on the molecular pathogenesis of RHD occurrence.

LncRNA NKILA relieves astrocyte inflammation and neuronal oxidative stress after cerebral ischemia/reperfusion by inhibiting the NF-κB pathway

BACKGROUND

Ischemic stroke is one of the major diseases of the cerebral vasculature. Currently, Ischemic stroke is the leading cause of neurological disability worldwide and has a high morbidity and mortality rate. The NF-κB interacting lncRNA (NKILA), the recently identified, is a key booster of NF-κB pathway. Accumulating studies have shown that NKILA plays a cancer suppressor in a variety of malignancies by regulating the NF-κB pathway. Nevertheless, the role of NKILA in ischemic stroke remains to be elucidated.

METHODS

We constructed a mouse model of middle cerebral artery occlusion-reperfusion (MCAO/R). TTC staining and dry and wet weight method were used to evaluate infarction and water content of brain tissue. RT-qPCR was performed to detect NKILA expression in cerebral infarction tissues. After labeling astrocytes and neurons with GFAP and NeuN, respectively, EDU and TUNEL staining were performed. Inflammatory factor levels were detected by ELISA. Commercial kits were used to detect the levels of oxidative stress-related factors. In in vitro, the HT22/U251 cell co-culture model was used for oxygen-glucose deprivation and re-introduction (OGD/R) to verify the effect of NKILA on neuronal cell inflammation and oxidative stress through astrocytes.

RESULTS

In in vivo experiments, NKILA significantly reduced cerebral infarction volume, brain water content and neurological score caused by MCAO/R. Moreover, NKILA blocked the activation of the NF-κB pathway, and inhibited astrocyte proliferation and neuron apoptosis as well as inflammation and oxidative stress. In in vitro experiments, NKILA significantly inhibited NF-κB pathway in HT22 cells. In addition, NKILA alleviated the inflammatory response and oxidative stress of U251 cells mediated by HT22 cells after OGD/R, and promoted U251 cell proliferation and inhibit their apoptosis.

CONCLUSIONS

In summary, we found for the first time that NKILA alleviates inflammatory response and oxidative stress after cerebral ischemia/reperfusion by blocking the activation of NF-κB pathway.

Long noncoding RNAs: A potential target in sepsis-induced cellular disorder

Sepsis, an inflammation-related clinical syndrome, is characterized by disrupted immune homeostasis accompanied by infection and multiple organ dysfunction as determined by the Sequential Organ Failure Assessment (SOFA). Substantial evidence has recently suggested that lncRNAs orchestrate various biological processes in diseases, and lncRNAs play special roles in the diagnosis and management of sepsis. To date, very few reviews have provided clear and comprehensive clues to demonstrate the roles of lncRNAs in the pathogenesis of sepsis. Based on previously published studies, in this review, we summarize the different functions of lncRNAs in sepsis-induced cellular disorders and sepsis-induced organ failure to show the potential roles of lncRNAs in the diagnosis and management of sepsis. We further depict the function of some lncRNAs known to be pivotal regulators in the pathogenesis of sepsis to discuss the underlying molecular events. Additionally, we list and discuss several hotspots in research on lncRNAs, which may be conducive to future lncRNA-targeted therapeutic approaches for sepsis treatment.

Long non-coding RNA NKILA alleviates airway inflammation in asthmatic mice by promoting M2 macrophage polarization and inhibiting the NF-κB pathway

Asthma remains a severe public health problem. Long non-coding RNAs (lncRNAs) are potent regulators in various diseases including asthma. This study investigated the mechanism of lncRNA NF-κB interacting lncRNA (NKILA) in asthma. The model of asthma in mice was induced by ovalbum (OVA). LncRNA NKILA expression, serum total IgE level and expressions of inflammatory cytokines (IL-4, IL-5, IL-13, and TNF-α) in OVA-induced asthmatic mice were detected. NKILA was overexpressed to evaluate the airway inflammation and airway hyperresponsiveness (AHR) in asthmatic mice. Macrophage abundance, M1/M2-polarized macrophage numbers, and expressions of macrophage polarization-related genes were detected. Levels of the NF-κB pathway-related proteins were determined. Downregulated NKILA and upregulated total IgE level and expressions of inflammatory cytokines were observed in asthmatic mice. NKILA overexpression alleviated AHR and airway inflammation in asthmatic mice. NKILA reduced macrophage abundance and promoted M2 macrophage polarization in asthmatic mice. NKILA inhibited the NF-κB pathway in asthmatic mice. We highlighted that lncRNA NKILA limited the asthmatic airway inflammation via promoting M2 macrophage polarization and inhibiting the NF-κB pathway.

Endothelial Dysfunction in Atherosclerotic Cardiovascular Diseases and Beyond: From Mechanism to Pharmacotherapies

The endothelium, a cellular monolayer lining the blood vessel wall, plays a critical role in maintaining multiorgan health and homeostasis. Endothelial functions in health include dynamic maintenance of vascular tone, angiogenesis, hemostasis, and the provision of an antioxidant, anti-inflammatory, and antithrombotic interface. Dysfunction of the vascular endothelium presents with impaired endothelium-dependent vasodilation, heightened oxidative stress, chronic inflammation, leukocyte adhesion and hyperpermeability, and endothelial cell senescence. Recent studies have implicated altered endothelial cell metabolism and endothelial-to-mesenchymal transition as new features of endothelial dysfunction. Endothelial dysfunction is regarded as a hallmark of many diverse human panvascular diseases, including atherosclerosis, hypertension, and diabetes. Endothelial dysfunction has also been implicated in severe coronavirus disease 2019. Many clinically used pharmacotherapies, ranging from traditional lipid-lowering drugs, antihypertensive drugs, and antidiabetic drugs to proprotein convertase subtilisin/kexin type 9 inhibitors and interleukin 1β monoclonal antibodies, counter endothelial dysfunction as part of their clinical benefits. The regulation of endothelial dysfunction by noncoding RNAs has provided novel insights into these newly described regulators of endothelial dysfunction, thus yielding potential new therapeutic approaches. Altogether, a better understanding of the versatile (dys)functions of endothelial cells will not only deepen our comprehension of human diseases but also accelerate effective therapeutic drug discovery. In this review, we provide a timely overview of the multiple layers of endothelial function, describe the consequences and mechanisms of endothelial dysfunction, and identify pathways to effective targeted therapies. SIGNIFICANCE STATEMENT: The endothelium was initially considered to be a semipermeable biomechanical barrier and gatekeeper of vascular health. In recent decades, a deepened understanding of the biological functions of the endothelium has led to its recognition as a ubiquitous tissue regulating vascular tone, cell behavior, innate immunity, cell-cell interactions, and cell metabolism in the vessel wall. Endothelial dysfunction is the hallmark of cardiovascular, metabolic, and emerging infectious diseases. Pharmacotherapies targeting endothelial dysfunction have potential for treatment of cardiovascular and many other diseases.

Functional roles of lncRNAs in the pathogenesis and progression of cancer

Long noncoding RNAs (lncRNAs) act as regulators of gene expression and pivotal transcriptional regulators in cancer cells via diverse mechanisms. lncRNAs involves a variety of pathological and biological activities, such as apoptosis, cell proliferation, metastasis, and invasion. By using microarray and RNA sequencing, it was identified that dysregulation of lncRNAs affects the tumorigenesis process. Taken together, these lncRNAs are putative biomarker and therapeutic target in human malignancies. In this review, I discuss the latest finding regarding the dysregulation of some important lncRNAs and their diverse mechanisms of these lncRNAs in the pathogenesis and progression of certain cancers; also, I summarize the possible roles of lncRNAs in clinical application for diagnosis and prognosis of cancer.

Profiling and Molecular Mechanism Analysis of Long Non-Coding RNAs and mRNAs in Pulmonary Arterial Hypertension Rat Models

Pulmonary arterial hypertension (PAH) is an immune-mediated disease with poor prognosis and associated with various inflammatory immune diseases. In fact, its pathogenesis is far from clear. Although long non-coding RNAs (lncRNAs) have been implicated in PAH, the molecular mechanisms remain largely unknown. For the first time, in lungs of monocrotaline-induced PAH rat models, we simultaneously detected the expression profiles of lncRNAs and mRNAs by high-throughput sequencing, and explored their roles with bioinformatics analysis and cell assay to discover more potential pathogenesis about PAH. Our data identified that a total of 559 lncRNAs and 691 mRNAs were differentially expressed in lungs during the pathogenesis of PAH. Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) analyses demonstrated that these dysregulated lncRNAs and mRNAs participated in important biological processes and pathways of PAH, among which inflammatory and immune responses represented the chief enriched pathway. The lncRNA-mRNA co-expression network was developed to uncover the hidden interactions between lncRNAs and mRNAs. Further, the expression levels of lncRNAs (NONRATT018084.2, NONRATT009275.2, NONRATT007865.2, and NONRATT026300.2) and mRNAs (LGALS3, PDGFC, SERPINA1, and NFIL3) were confirmed using quantitative real-time PCR. In the end, lncRNA NONRATT009275.2 could facilitate macrophage polarization to M2 type and be involved in inflammatory immune response. In conclusion, this study provided candidate drug targets and potential roles on lncRNAs in the pathogenesis of PAH, and several key regulatory genes were identified, which laid the initial foundation for further mechanism study in PAH.

Effect of Baicalin on Transcriptome Changes in Piglet Vascular Endothelial Cells Induced by a Combination of Glaesserella parasuis and Lipopolysaccharide

Glaesserella parasuis causes porcine Glässer's disease and lipopolysaccharide (LPS) induces acute inflammation and pathological damage. Baicalin has antioxidant, antimicrobial, and anti-inflammatory functions. Long noncoding RNAs (lncRNAs) play key regulatory functions during bacterial infection. However, the role of lncRNAs in the vascular dysfunction induced by a combination of G. parasuis and LPS during systemic inflammation and the effect of baicalin on lncRNA expression induced in porcine aortic vascular endothelial cells (PAVECs) by a combination of G. parasuis and LPS have not been investigated. In this study, we investigated the changes in lncRNA and mRNA expression induced in PAVECs by G. parasuis, LPS, or a combination of G. parasuis and LPS, and the action of baicalin on lncRNA expression induced in PAVECs by the combination of G. parasuis and LPS. Our results showed 133 lncRNAs and 602 genes were differentially expressed when PAVECs were stimulated with the combination of G. parasuis and LPS, whereas 107 lncRNAs and 936 genes were differentially expressed when PAVECs were stimulated with the combination of G. parasuis and LPS after pretreatment with baicalin. The Kyoto Encyclopedia of Genes and Genomes (KEGG) analysis showed the dominant signaling pathways triggered by the combination of G. parasuis and LPS were the tumor necrosis factor signaling pathway, phosphatidylinositol signaling system, and inositol phosphate metabolism. Protein-protein interaction network analysis showed the differentially expressed target genes of the differentially expressed lncRNAs (DELs) were related to each other. A coexpression analysis indicated the expression levels of the DELs were co-regulated with those of their differentially expressed target genes. This is the first study to systematically compare the changes in lncRNAs and mRNAs in PAVECs stimulated with a combination of G. parasuis and LPS. Our data clarified the mechanisms underlying the vascular inflammation and damage triggered by G. parasuis and LPS, and it may provide novel targets for the treatment of LPS-induced systemic inflammation.

Attenuated lncRNA NKILA Enhances the Secretory Function of Airway Epithelial Cells Stimulated by Mycoplasma pneumoniae via NF-κB

The secretory function of airway epithelial cells is important in the pathogenesis of Mycoplasma pneumoniae pneumonia (MPP). To investigate the regulatory function of NKILA (nuclear factor-κB (NF-κB) interacting long noncoding RNA (lncRNA)) in MPP, we first detected NKILA as well as the concentration of interleukin 8 (IL-8) and tumor necrosis factor-α (TNF-α) in bronchoalveolar lavage fluid of children with MPP. Then, NKILA was knocked down in epithelial cells to investigate its effect on their secretory function. The results suggested that NKILA was downregulated in children with MPP, while IL-8 and TNF-α levels increased. Knockdown of NKILA in vitro promoted the inflammatory effects of Mycoplasma pneumoniae (MP) in epithelial A549 and BEAS-2B cells. Knockdown of NKILA promoted inhibitor of κBα (IκBα) phosphorylation and degradation, and NF-κB p65 nuclear translocation. Furthermore, RNA immunoprecipitation showed that NKILA could physically bind to IκBα in MP-treated A549 cells. Collectively, our data demonstrated that attenuation of NKILA enhances the effects of MP-stimulated secretory functions of epithelial cells via regulation of NF-κB signaling.

The interaction between miRNAs/lncRNAs and nuclear factor-κB (NF-κB) in human disorders

Nuclear factor-κB (NF-κB) represents a group of inducible transcription factors (TFs) regulating the expression of a great variety of genes implicated in diverse processes, particularly modulation of immune system responses. This TF has functional interactions with non-coding RNAs, constructing a complicated network through which NF-κB, miRNAs, and lncRNAs coordinately regulate gene expression at different facets. This type of interaction is involved in the pathophysiology of several human disorders including both neoplastic disorders and non-neoplastic conditions. MALAT1 and NKILA are among lncRNAs whose interactions with NF-κB have been vastly assessed in different conditions including cancer and inflammatory conditions. In addition, miR-146a/b has functional interactions with this TF in different contexts. Although miRNAs have mutual interactions with NF-κB, the regulatory role of miRNAs on this TF has been more clarified. The aim of the current review is to explore the function of NF-κB-related miRNAs and lncRNAs in these two types of human disorders.

LncRNAs and Immunity: Coding the Immune System with Noncoding Oligonucleotides

Long noncoding RNAs (lncRNAs) represent key regulators of gene transcription during the inflammatory response. Recent findings showed lncRNAs to be dysregulated in human diseases, such as inflammatory bowel disease, diabetes, allergies, asthma, and cancer. These noncoding RNAs are crucial for immune mechanism, as they are involved in differentiation, cell migration and in the production of inflammatory mediators through regulating protein–protein interactions or their ability to assemble with RNA and DNA. The last interaction can occur in cis or trans and is responsible for all the possible lncRNAs biological effects. Our proposal is to provide an overview on lncRNAs roles and functions related to immunity and immune mediated diseases, since these elucidations could be beneficial to untangle the complex bond between them.

Mesenchymal stem cell-originated exosomal lncRNA HAND2-AS1 impairs rheumatoid arthritis fibroblast-like synoviocyte activation through miR-143-3p/TNFAIP3/NF-κB pathway

Background

Long non-coding RNA heart and neural crest derivatives expressed 2-antisense RNA 1 (HAND2-AS1) was found to be elevated in rheumatoid arthritis (RA) fibroblast-like synoviocytes (RA-FLSs). However, whether HAND2-AS1 functions as an exosomal lncRNA related to mesenchymal stem cells (MSCs) in RA progression is unknown.

Methods

The expression of HAND2-AS1, microRNA (miR)-143-3p, and tumor necrosis factor alpha-inducible protein 3 (TNFAIP3) was detected using quantitative real-time polymerase chain reaction and Western blot. Cell proliferation, apoptosis, migration, and invasion were detected using cell counting kit-8, flow cytometry, and wound healing and transwell assays. The levels of tumor necrosis factor-α (TNF-α) and interleukins (IL)-6 were analyzed using enzyme-linked immunosorbent assay. The level of phosphorylated-p65 was examined by Western blot. The binding interaction between miR-143-3p and HAND2-AS1 or TNFAIP3 was confirmed by the dual-luciferase reporter and RIP assays. Exosomes were isolated by ultracentrifugation and qualified by transmission electron microscopy (TEM), nanoparticle tracking analysis (NTA), and Western blot.

Results

HAND2-AS1 was lowly expressed in RA synovial tissues, and HAND2-AS1 re-expression suppressed the proliferation, motility, and inflammation and triggered the apoptosis in RA-FLSs via the inactivation of NF-κB pathway. Mechanistically, HAND2-AS1 directly sponged miR-143-3p and positively regulated TNFAIP3 expression, the target of miR-143-3p. Moreover, the effects of HAND2-AS1 on RA-FLSs were partially attenuated by miR-143-3p upregulation or TNFAIP3 knockdown. HAND2-AS1 could be packaged into hMSC-derived exosomes and absorbed by RA-FLSs, and human MSC-derived exosomal HAND2-AS1 also repressed above malignant biological behavior of RA-FLSs.

Conclusion

MSC-derived exosomes participated in the intercellular transfer of HAND2-AS1 and suppressed the activation of RA-FLSs via miR-143-3p/TNFAIP3/NF-κB pathway, which provided a novel insight into the pathogenesis and treatment of RA.

Epigenetic mechanisms underlying the benefits of flavonoids in cardiovascular health and diseases: are long non-coding RNAs rising stars?

Cardiovascular diseases (CVDs) rank as the first leading cause of death globally. High dietary polyphenol (especially flavonoids) intake has strongly been associated with low incidence of the primary outcome, overall mortality, blood pressure, inflammatory biomarkers, onset of new-onset type 2 diabetes mellitus (T2DM), and obesity. Phytogenic flavonoids affect the physiological and pathological processes of CVDs by modulating various biochemical signaling pathways. Non-coding RNAs (ncRNAs) have attracted increasing attention as fundamental regulator of gene expression involved in CVDs. Among the different ncRNA subgroups, long ncRNAs (lncRNAs) have recently emerged as regulatory eukaryotic transcripts and therapeutic targets with important and diverse functions in health and diseases. lncRNAs may be associated with the initiation, development and progression of CVDs by modulating acute and chronic inflammation, adipogenesis and lipid metabolism, and cellular physiology. This review summarizes this research on the modulatory effects of lncRNAs and their roles in mediating cellular processes. The mechanisms of action of flavonoids underlying their therapeutic effects on CVDs are also discussed. Based on our review, flavonoids might facilitate a significant epigenetic modification as part (if not full) of their tissue-/cell-related biological effects. This finding may be attributed to their interaction with cellular signaling pathways involved in chronic diseases. Certain lncRNAs might be the target of specific flavonoids, and some critical signaling processes involved in the intervention of CVDs might mediate the therapeutic roles of flavonoids.

Role of DNA methylation on human CTSG in dermatomyositic myoideum

Dermatomyositis (DM) is a multifactorial chronic autoimmune disorder with characteristic skin and muscle pathological changes and involvement of other organ systems. Cathepsin G (CTSG) contributes to the risk of developing DM, which is likely to be associated with inflammatory cytokines. Differential DNA methylation on CTSG has been determined to be implicated in DM in vivo. However, the underlying mechanism of this epigenetic regulation on CTST in DM is poorly explored. In this study, we investigated DNA methylation signature on CTSG at single-nucleotide resolution in quadriceps femoris of six DM patients and paracancerous muscles of three patients with rhabdomyosarcoma on inner thigh using pyrosequencing and observed that the overall DNA methylation level of CTSG was increased in DM compared with control, in which CpG loci at third and fourth exons but not promoter contributed to the significant hypermethylation. Furthermore, we observed that transcription and DNA methylation of CTSG were both declined in DNMT3a knockdown compared with DNMT1 and DNMT3b knockdown in human skeletal muscle SJCRH30 and A-204 cell lines exposed to tumor necrosis factor-α. Furthermore, Bortezomib (NF-κB inhibitor) and Brevilin A (JAK/STAT inhibitor) were employed to treat SJCRH30 and A-204 cells, respectively, and we observed that CTSG was hypomethylated and silenced after Bortezomib treatment compared with untreatment and Brevilin A. Finally, chromatin immunoprecipitation-quantitative polymerase chain reaction indicated that DNMT3a could bind to the coding regions of CTSG and the interaction was dependent on NF-κB activity. Taken together, our results determined a novel regulatory mechanism of DNA methylation on CTSG in DM.

Role of Kruppel-like factor 4 in atherosclerosis

Atherosclerosis is one of the chronic progressive diseases, which is caused by vascular injury and promoted by the interaction of various inflammatory factors and inflammatory cells. In recent years, kruppel-like factor 4 (KLF4), a significant transcription factor that participated in cell growth, differentiation and proliferation, has been proved to cause substantial impacts on regulating cardiovascular disease. This paper will give a comprehensive summary to highlight KLF4 as a crucial regulator of foam cell formation, vascular smooth muscle cells (VSMCs) phenotypic transformation, macrophage polarization, endothelial cells inflammation, lymphocyte differentiation and cell proliferation in the process of atherosclerosis. Recent studies show that KLF4 may be an important "molecular switch" in the process of improving vascular injury and inflammation under harmful stimulation, suggesting that KLF4 is a latent disease biomarker for the therapeutic target of atherosclerosis and vascular disease.

LOX-1 Regulates P. gingivalis-Induced Monocyte Migration and Adhesion to Human Umbilical Vein Endothelial Cells

Porphyromonas gingivalis (P. gingivalis) is one of the main periodontal bacteria. This pathogen was reported to enhance monocyte migration and adhesion to endothelial cells in atherosclerosis. The scavenger receptor lectin-like oxidized low-density lipoprotein receptor-1 (LOX-1) plays a pivotal role in atherogenesis. The aim of this study was to investigate whether LOX-1 modulates P. gingivalis-mediated monocyte migration and adhesion to endothelial cells and how it works. The results showed that the migration and adhesion of monocytic THP-1 cells to human umbilical vein endothelial cells (HUVECs) were significantly enhanced when HUVECs or THP-1 cells were challenged with P. gingivalis. Meanwhile, the expression level of LOX-1 in both HUVECs and THP-1 cells were also significantly increased by P. gingivalis stimulation. It is well known that ligand/receptor pairs monocyte chemoattractant protein-1 (MCP-1)/CC chemokine receptor 2 (CCR2), selectins/Integrins, and cell adhesion molecules (CAMs)/Integrins mediate monocyte migration and adhesion to endothelial cells. In this study, LOX-1 was demonstrated to be crucially involved in P. gingivalis-induced THP-1 cell migration and adhesion to HUVECs, by regulating expression of ligands MCP-1, intercellular adhesion molecule-1 (ICAM-1) and E-selectin in HUVECs and that of their receptors CCR2 and Integrin αMβ2 in THP-1 cells. The nuclear factor-kappa B (NF-κB) signaling pathway was proved to be involved in this process. In conclusion, LOX-1 plays a crucial role in P. gingivalis-induced monocyte migration and adhesion to endothelial cells. This result implies LOX-1 may act as a bridge in linking periodontitis to atherosclerosis.

Active fraction of Polyrhachis vicina Rogers (AFPR) suppressed breast cancer growth and progression via regulating EGR1/lncRNA-NKILA/NF-κB axis

Breast cancer (BC) is a major contributor of cancer-associated mortality in women. It is essential to find new therapeutic targets and drugs. Polyrhachis vicina Rogers is one of the Traditional Chinese Medicine (TCM). Our previous studies have shown an active fraction of Polyrhachis vicina Rogers (AFPR) has significant anti-inflammatory activity, suggesting its anti-cancer effect. Here, we aimed to explore the inhibitory effects of AFPR on BC and reveal its mechanism. The effects of AFPR on BC were examined by cell proliferation assay, wound healing assay, invasion assay and xenograft assay. Microarray sequencing, qRT-PCR, Western blot, chromatin immunoprecipitation assay and luciferase reporter assay were performed to investigate the regulation of AFPR on related genes and underlying mechanisms. As a result, AFPR suppressed BC cell growth, migration and invasion and inhibited tumor growth. LncRNA NKILA was most prominently upregulated in AFPR-treated MCF7 cells. AFPR inactivated NF-κB signaling pathway via regulating NKILA. Furthermore, AFPR regulated the expression of NKILA by inhibiting its transcript suppressor EGR1. This study firstly indicated that AFPR was a potential inhibitor of BC development via regulating EGR1/NKILA/NF-κB axis.

LncRNA TUG1 alleviates sepsis-induced acute lung injury by targeting miR-34b-5p/GAB1

Background

Sepsis-induced acute lung injury (ALI) is a clinical syndrome characterized by the injury of alveolar epithelium and pulmonary endothelial cells. This study aimed to investigate the regulation of long noncoding RNA (lncRNA) taurine up-regulated gene 1 (TUG1) in a murine ALI model and in primary murine pulmonary microvascular endothelial cells (PMVECs) stimulated with lipopolysaccharide (LPS).

Methods

Adult C57BL/6 mice were intravenously injected with or without TUG1-expressiong adenoviral vector or control vector 1 week before the establishment of ALI model. PMVECs were transfected with TUG1-expressiong or control vectors followed by LPS stimulation. MiR-34b-5p was confirmed as a target of TUG1 using dual-luciferase reporter assay. GRB2 associated binding protein 1 (GAB1) was confirmed as a downstream target of miR-34b-5p using the same method. In the rescue experiment, PMVECs were co-transfected with TUG1-expressing vector and miR-34b-5p mimics (or control mimics) 24 h before LPS treatment.

Results

ALI mice showed reduced levels of TUG1, pulmonary injury, and induced apoptosis and inflammation compared to the control group. The overexpression of TUG1 in ALI mice ameliorated sepsis-induced pulmonary injury, apoptosis and inflammation. TUG1 also showed protective effect in LPS-treated PMVECs. The expression of MiR-34b-5p was negatively correlated with the level of TUG1. TUG1-supressed apoptosis and inflammation in LPS-stimulated PMVECs were restored by miR-34b-5p overexpression. GAB1 was inversely regulated by miR-34b-5p but was positively correlated with TUG1 expression.

Conclusion

TUG1 alleviated sepsis-induced inflammation and apoptosis via targeting miR-34b-5p and GAB1. These findings suggested that TUG1 might be served as a therapeutic potential for the treatment of sepsis-induced ALI.

Non-coding RNAs as Epigenetic Gene Regulators in Cardiovascular Diseases

Epigenetic gene regulations can be considered as de-novo initiation of abnormal molecular signaling events whose regulation is otherwise required during normal or specific developmental stages of the organisms. Primarily, three different mechanisms have been identified to participate in epigenetic gene regulations which include, DNA methylation, non-coding RNA species (microRNAs [miRNA], and long non-coding RNAs [LNC-RNA]) and histone modifications. These de-novo epigenetic mechanisms have been associated with altered normal cellular functions which eventually facilitate normal cells to transition into an abnormal phenotype. Among the three modes of regulation, RNA species which are usually considered to be less stable, can be speculated to initiate instant alterations in gene expression compared to DNA methylation or histone modifications. However, LNC-RNAs appear to be more stable in the cells than the other RNA species. Moreover, there is increasing literature which clearly suggests that a single specific LNC-RNA can regulate multiple mechanisms and disease phenotypes. With specific focus on cardiovascular diseases, here we attempt to provide UpToDate information on the functional role of miRNAs and LNC-RNAs. Here we discuss the role of these epigenetic mediators in different components of cardiovascular disease which include physiopathological heart development, athersclerosis, retenosis, diabetic hearts, myocardial infarction, ischemia-reperfusion, heart valve disease, aortic aneurysm, osteogenesis, angiogenesis and hypoxia in the heart. While there is abundant literature support that shows the involvement of many LNC-RNAs and miRNAs in cardiovascular diseases, very few RNA species have been identified which regulate epigenetic mechanisms which is the current focus in this article. Understanding the role of these RNA species in regulating epigenetic mechanisms in different cell types causing cardiovascular disease, would advance the field and promote disease prevention approaches that are aimed to target epigenetic mechanisms.

LncRNA HOTAIRM1 promotes osteogenesis by controlling JNK/AP-1 signalling-mediated RUNX2 expression

Mesenchymal stem cells (MSCs) have potential ability to differentiate into osteocytes in response to in vitro specific induction. However, the molecular basis underlying this biological process remains largely unclear. In this study, we identify lncRNA HOTAIRM1 as a critical regulator to promote osteogenesis of MSCs. Loss of HOTAIRM1 significantly inhibits the calcium deposition and alkaline phosphatase activity of MSCs. Mechanistically, we find that HOTAIRM1 positively modulates the activity of JNK and c-Jun, both of which are widely accepted as crucial regulators of osteogenic differentiation. More importantly, c-Jun is found to be functionally involved in the regulation of RUNX2 expression, a master transcription factor of osteogenesis. In detail, c-Jun can help recruit the acetyltransferase p300 to RUNX2 promoter, facilitating acetylation of histone 3 at K27 site, therefore epigenetically activating RUNX2 gene transcription. In summary, this study highlights the functional importance of HOTAIRM1 in regulation of osteogenesis, and we characterize HOTAIRM1 as a promising molecular target for bone tissue repair and regeneration.

LncRNA NKILA integrates RXFP1/AKT and NF-κB signalling to regulate osteogenesis of mesenchymal stem cells

Mesenchymal stem cells (MSCs) are previously found to have potential capacity to differentiate into osteocytes when exposed to specific stimuli. However, the detailed molecular mechanism during this progress remains largely unknown. In the current study, we characterized the lncRNA NKILA as a crucial positive regulator for osteogenesis of MSCs. NKILA attenuation significantly inhibits the calcium deposition and alkaline phosphatase activity of MSCs. More interestingly, we defined that NKILA is functionally involved in the regulation of RXFP1/PI3K‐AKT and NF‐κB signalling. Knockdown of NKILA dramatically down‐regulates the expression of RXFP1 and then reduces the activity of AKT, a downstream regulator of RXFP1 signalling which is widely accepted as an activator of osteogenesis. Moreover, we identify NF‐κB as another critical regulator implicated in NKILA‐mediated osteogenic differentiation. Inhibition of NF‐κB can induce the expression of RUNX2, a master transcription factor of osteogenesis, in a HDAC2‐mediated deacetylation manner. Thus, this study illustrates the regulatory function of NKILA in osteogenesis through distinct signalling pathways, therefore providing a new insight into searching for new molecular targets for bone tissue repair and regeneration.

UCA1 long non-coding RNA: An update on its roles in malignant behavior of cancers

The lncRNA urothelial carcinoma-associated 1 (UCA1) is a 1.4 kb long transcript which has been firstly recognized in human bladder cancer cell line. Subsequent studies revealed its over-expression in a wide array of human cancer cell lines and patients' samples. In addition to conferring malignant phenotype to cells, it enhances resistance to conventional anti-cancer drugs. Moreover, transcript levels of this lncRNA have been regarded as diagnostic markers in several cancer types including gastric, bladder and liver cancers. The underlying mechanism of its participation in carcinogenesis has been identified in some cancer types. Sponging tumor suppressor miRNAs, interacting with cancer-promoting signaling pathways and enhancing cell cycle progression are among these mechanisms. Although few studies have shown anti-carcinogenic properties for this lncRNA, the bulk of evidence supports its oncogenic roles. In the current study, we have reviewed the current literature on the role of UCA1 in the carcinogenic process based on the results of in vitro studies, investigations in animal models and assessment of UCA1 expression in clinical samples.

Long Noncoding RNA HOXA-AS3 Integrates NF-κB Signaling To Regulate Endothelium Inflammation

The long noncoding RNA HOXA-AS3 has recently been reported to act as a critical regulator in inflammation-linked lung adenocarcinoma. However, the roles of HOXA-AS3 in endothelium inflammation and related vascular disorders remain poorly defined. In the current study, we identified HOXA-AS3 to be a critical activator to promote NF-κB-mediated endothelium inflammation. HOXA-AS3, a chromatin-associated regulator which colocalizes with NF-κB at specific gene promoters, was found to interact with NF-κB and positively regulate its activity through control of the expression of the NF-κB inhibitor protein IκBα and the acetylation status at the K310 site of p65. More importantly, clinicopathological analysis showed that HOXA-AS3 expression has a significant positive correlation with atherosclerosis. Thus, we conclude that HOXA-AS3 may serve as a crucial biomarker for the clinical diagnosis of atherosclerosis, as well as a promising therapeutic target for the treatment of multiple inflammatory vascular diseases. In addition, this study suggests the functional importance of HOXA-AS3 in the regulation of inflammatory disorders.

Concise Review: Regulation of Self-Renewal in Normal and Malignant Hematopoietic Stem Cells by Krüppel-Like Factor 4

Pluripotent and tissue‐specific stem cells, such as blood‐forming stem cells, are maintained through a balance of quiescence, self‐renewal, and differentiation. Self‐renewal is a specialized cell division that generates daughter cells with the same features as the parental stem cell. Although many factors are involved in the regulation of self‐renewal, perhaps the most well‐known factors are members of the Krüppel‐like factor (KLF) family, especially KLF4, because of the landmark discovery that this protein is required to reprogram somatic cells into induced pluripotent stem cells. Because KLF4 regulates gene expression through transcriptional activation or repression via either DNA binding or protein‐to‐protein interactions, the outcome of KLF4‐mediated regulation largely depends on the cellular context, cell cycle regulation, chromatin structure, and the presence of oncogenic drivers. This study first summarizes the current understanding of the regulation of self‐renewal by KLF proteins in embryonic stem cells through a KLF circuitry and then delves into the potential function of KLF4 in normal hematopoietic stem cells and its emerging role in leukemia‐initiating cells from pediatric patients with T‐cell acute lymphoblastic leukemia via repression of the mitogen‐activated protein kinase 7 pathway. stem cells translational medicine2019;8:568–574