Long-Chain Non-Coding RNA Metastasis-Related Lung Adenocarcinoma Transcript 1 (MALAT1) Promotes the Proliferation and Migration of Human Pulmonary Artery Smooth Muscle Cells (hPASMCs) by Regulating the MicroRNA-503 (miR-503)/Toll-Like Receptor 4 (TLR4) Signal Axis

Advances in the study of S100A9 in cardiovascular diseases

Cardiovascular disease (CVD) is a group of diseases that primarily affect the heart or blood vessels, with high disability and mortality rates, posing a serious threat to human health. The causative factors, pathogenesis, and characteristics of common CVD differ, but they all involve common pathological processes such as inflammation, oxidative stress, and fibrosis. S100A9 belongs to the S100 family of calcium-binding proteins, which are mainly secreted by myeloid cells and bind to the Toll-like receptor 4 and receptor for advanced glycation end products and is involved in regulating pathological processes such as inflammatory response, fibrosis, vascular calcification, and endothelial barrier function in CVD. The latest research has found that S100A9 is a key biomarker for diagnosing and predicting various CVD. Therefore, this article reviews the latest research progress on the diagnostic and predictive, and therapeutic value of S100A9 in inflammatory-related CVD such as atherosclerosis, myocardial infarction, and arterial aneurysm and summarizes its molecular mechanisms in the progression of CVD, aiming to explore new predictive methods and to identify potential intervention targets for CVD in clinical practice.

Roles of LncRNAs in the Pathogenesis of Pulmonary Hypertension

Pulmonary hypertension (PH) is a persistently progressive, incurable, multifactorial associated fatal pulmonary vascular disease characterized by pulmonary vascular remodeling. Long noncoding RNAs (lncRNAs) are involved in regulating pathological processes such as pulmonary vasoconstriction, thickening, remodeling, and inflammatory cell infiltration in PH by acting on different cell types. Because of their differential expression in PH patients, as demonstrated by the observation that some lncRNAs are significantly upregulated while others are significantly downregulated in PH patients, lncRNAs are potentially useful biomarkers for assessing disease progression and diagnosis or prognosis in PH patients. This article provides an overview of the different mechanisms by which lncRNAs are involved in the pathogenesis of PH.

G6PD is a prognostic biomarker correlated with immune infiltrates in lung adenocarcinoma and pulmonary arterial hypertension

BACKGROUND

Lung adenocarcinoma (LUAD) with Pulmonary arterial hypertension (PAH) shows a poor prognosis. Detecting related genes is imperative for prognosis prediction.

METHODS

The gene expression profiles of LUAD and PAH were acquired from The Cancer Genome Atlas (TCGA) and the Gene Expression Omnibus (GEO) database, respectively. The co-expression modules associated with LUAD and PAH were evaluated using the Weighted Gene Co-Expression Network Analysis (WGCNA). The relationship between key gene expression with immune-cell infiltration and the tumor immune microenvironment (TIME) was evaluated. We confirmed the mRNA and protein levels in vivo and vitro. G6PD knockdown was used to conduct the colony formation assay, transwell invasion assay, and scratch wound assay of A549 cells. EDU staining and CCK8 assay were performed on G6PD knockdown HPASMCs. We identified therapeutic drug molecules and performed molecular docking between the key gene and small drug molecules.

RESULTS

Three major modules and 52 overlapped genes were recognized in LUAD and PAH. We identified the key gene G6PD, which was significantly upregulated in LUAD and PAH. In addition, we discovered a significant difference in infiltration for most immune cells between high- and low-G6PD expression groups. The mRNA and protein expressions of G6PD were significantly upregulated in LUAD and PAH. G6PD knockdown decreased proliferation, cloning, and migration of A549 cells and cell proliferation in HPASMCs. We screened five potential drug molecules against G6PD and targeted glutaraldehyde by molecular docking.

CONCLUSIONS

This study reveals that G6PD is an immune-related biomarker and a possible therapeutic target for LUAD and PAH patients.

The Long non-coding RNA MALAT1 functions as a competing endogenous RNA to regulate vascular remodeling by sponging miR-145-5p/HK2 in hypertension

Long non-coding RNAs (LncRNAs) have been found to play a regulatory role in the pathophysiology of vascular remodeling-associated illnesses through the lncRNA-microRNA (miRNA) regulation axis. LncRNA metastasis-associated lung adenocarcinoma transcript 1 (MALAT1) is thought to be involved in proliferation, migration, apoptosis, and calcification of vascular smooth muscle cells (VSMCs). The purpose of this study was to investigate the regulatory role of MALAT1 on vascular remodeling in hypertension. Our data indicate that the expression of MALAT1 is significantly upregulated in hypertensive aortic smooth muscle. Knockdown of MALAT1 inhibited the proliferation, migration, and phenotypic transition of VSMCs induced by Ang II. Bioinformatics analysis was used to predict the complementary binding of miR-145-5p to the 3'-untranslated region of MALAT1. Besides, the expressions of MALAT1 and miR-145-5p were negatively correlated, while luciferase reporter assays and RNA immunoprecipitation assay validated the interaction between miR-145-5p and MALAT1. The proliferation, migration and phenotypic transformation of VSMCs induced by overexpression of MALAT1 were reversed in the presence of miR-145-5p. Furthermore, we verified that miR-145-5p could directly target and bind to hexokinase 2 (HK2) mRNA, and that HK2 expression was negatively correlated with miR-145-5p in VSMCs. Knockdown of HK2 significantly inhibited the effects of overexpression of MALAT1 on Ang II-induced VSMCs proliferation, migration and phenotypic transformation. Taken together, the MALAT1/miR-145-5p/HK2 axis may play a critical regulatory role in the vascular remodeling of VSMCs in hypertension.

Unraveling the epigenetic landscape of pulmonary arterial hypertension: implications for personalized medicine development

Pulmonary arterial hypertension (PAH) is a multifactorial disease associated with the remodeling of pulmonary blood vessels. If left unaddressed, PAH can lead to right heart failure and even death. Multiple biological processes, such as smooth muscle proliferation, endothelial dysfunction, inflammation, and resistance to apoptosis, are associated with PAH. Increasing evidence suggests that epigenetic factors play an important role in PAH by regulating the chromatin structure and altering the expression of critical genes. For example, aberrant DNA methylation and histone modifications such as histone acetylation and methylation have been observed in patients with PAH and are linked to vascular remodeling and pulmonary vascular dysfunction. In this review article, we provide a comprehensive overview of the role of key epigenetic targets in PAH pathogenesis, including DNA methyltransferase (DNMT), ten-eleven translocation enzymes (TET), switch-independent 3A (SIN3A), enhancer of zeste homolog 2 (EZH2), histone deacetylase (HDAC), and bromodomain-containing protein 4 (BRD4). Finally, we discuss the potential of multi-omics integration to better understand the molecular signature and profile of PAH patients and how this approach can help identify personalized treatment approaches.

Emerging role of long non-coding RNA MALAT1 related signaling pathways in the pathogenesis of lung disease

Long non-coding RNAs (lncRNAs) are endogenously expressed RNAs longer than 200 nt that are not translated into proteins. In general, lncRNAs bind to mRNA, miRNA, DNA, and proteins and regulate gene expression at various cellular and molecular levels, including epigenetics, transcription, post-transcription, translation, and post-translation. LncRNAs play important roles in many biological processes, such as cell proliferation, apoptosis, cell metabolism, angiogenesis, migration, endothelial dysfunction, endothelial-mesenchymal transition, regulation of cell cycle, and cellular differentiation, and have become an important topic of study in genetic research in health and disease due to their close link with the development of various diseases. The exceptional stability, conservation, and abundance of lncRNAs in body fluids, have made them potential biomarkers for a wide range of diseases. LncRNA MALAT1 is one of the best-studied lncRNAs in the pathogenesis of various diseases, including cancers and cardiovascular diseases. A growing body of evidence suggests that aberrant expression of MALAT1 plays a key role in the pathogenesis of lung diseases, including asthma, chronic obstructive pulmonary diseases (COPD), Coronavirus Disease 2019 (COVID-19), acute respiratory distress syndrome (ARDS), lung cancers, and pulmonary hypertension through different mechanisms. Here we discuss the roles and molecular mechanisms of MALAT1 in the pathogenesis of these lung diseases.

The Common LncRNAs of Neuroinflammation-Related Diseases

Spatio-temporal specific long noncoding RNAs (lncRNAs) play important regulatory roles not only in the growth and development of the brain but also in the occurrence and development of neurologic diseases. Generally, the occurrence of neurologic diseases is accompanied by neuroinflammation. Elucidation of the regulatory mechanisms of lncRNAs on neuroinflammation is helpful for the clinical treatment of neurologic diseases. This paper focuses on recent findings on the regulatory effect of lncRNAs on neuroinflammatory diseases and selects 10 lncRNAs that have been intensively studied to analyze their mechanism action. The clinical treatment status of lncRNAs as drug targets is also reviewed. SIGNIFICANCE STATEMENT: Gene therapies such as clustered regularly interspaced short palindrome repeats technology, antisense RNA technology, and RNAi technology are gradually applied in clinical treatment, and the development of technology is based on a large number of basic research investigations. This paper focuses on the mechanisms of lncRNAs regulation of neuroinflammation, elucidates the beneficial or harmful effects of lncRNAs in neurosystemic diseases, and provides theoretical bases for lncRNAs as drug targets.

Biomarker-based approach to determine etiology and severity of pulmonary hypertension: Focus on microRNA

Pulmonary arterial hypertension (PAH) is characterized by remodeling of the pulmonary arteries, and defined by elevated pulmonary arterial pressure, measured during right heart catheterization. There are three main challenges to the diagnostic and therapeutic process of patients with PAH. First, it is difficult to differentiate particular PAH etiology. Second, invasive diagnostic is required to precisely determine the severity of PAH, and thus to qualify patients for an appropriate treatment. Third, the results of treatment of PAH are unpredictable and remain unsatisfactory. MicroRNAs (miRNAs) are small non-coding RNAs that regulate post transcriptional gene-expression. Their role as a prognostic, and diagnostic biomarkers in many different diseases have been studied in recent years. MiRNAs are promising novel biomarkers in PAH due to their activity in various molecular pathways and processes underlying PAH. Lack of biomarkers to differentiate between particular PAH etiology and evaluate the severity of PAH, as well as paucity of therapeutic targets in PAH open a new field for the possibility to use miRNAs in these applications. In our article, we discuss the potential of miRNAs use as diagnostic tools, prognostic biomarkers and therapeutic targets in PAH.

Focus on long non-coding RNA MALAT1: Insights into acute and chronic lung diseases

Acute lung injury (ALI) is a pulmonary illness with a high burden of morbidity and mortality around the world. Chronic lung diseases also represent life-threatening situations. Metastasis-associated lung adenocarcinoma transcript 1 (MALAT1) is a type of long non-coding RNA (lncRNA) and is highly abundant in lung tissues. MALAT1 can function as a competitive endogenous RNA (ceRNA) to impair the microRNA (miRNA) inhibition on targeted messenger RNAs (mRNAs). In this review, we summarized that MALAT1 mainly participates in pulmonary cell biology and lung inflammation. Therefore, MALAT1 can positively or negatively regulate ALI and chronic lung diseases (e.g., chronic obstructive pulmonary disease (COPD), bronchopulmonary dysplasia (BPD), pulmonary fibrosis, asthma, and pulmonary hypertension (PH)). Besides, we also found a MALAT1-miRNA-mRNA ceRNA regulatory network in acute and chronic lung diseases. Through this review, we hope to cast light on the regulatory mechanisms of MALAT1 in ALI and chronic lung disease and provide a promising approach for lung disease treatment.

lncRNA MALAT1 Promotes Diabetic Nephropathy Progression via miR-15b-5p/TLR4 Signaling Axis

Objective

The long noncoding RNA metastasis-associated lung adenocarcinoma transcript 1 (MALAT1) are closely associated with the pathogenesis of diabetic nephropathy (DN). But a complete mechanism for MALAT1 in DN has yet to be identified. This study investigated the effect of MALAT1 on DN through the regulation of miR-15b-5p/TLR4 signaling.

Method

Renal tissues were collected from DN patients. Human renal tubular epithelial cells (HK-2) were used as a model of DN induced by high glucose (HG). We then measured the viability, apoptosis, and inflammatory cytokine levels of HK-2 cells using the corresponding assays. Following transfections of si-MALAT1, si-MALAT1+miR-15b-5p inhibitor, or si-MALAT1+vector TLR4 into HG-stimulated HK-2 cells, cell viability, apoptosis, and inflammatory cytokines were again measured. Furthermore, dual-luciferase reporter assay validated the interactions of MALAT1/miR-15b-5p and miR-15b-5p/TLR4. In addition, the interaction between MALAT1 and miR-15b-5p was investigated by RNA immunoprecipitation (RIP).

Results

A significant upregulation of MALAT1 was observed in DN kidney tissues, as well as in HG-stimulated HK-2 cells. MALAT1 knockdown attenuates the inhibition of cell viability, apoptosis, and inflammatory response induced by HG in HK-2 cells. Moreover, a miR-15b-5p inhibitor or TLR4 overexpression reversed the above effects induced by MALAT1 knockdown.

Conclusion

These results indicate that reduced MALAT1 ameliorates HG-stimulated HK-2 cell damage through an inhibition of the miR-15b-5p/TLR4 axis. MALAT1 may serve as a biomarker and potential therapeutic target for DN.

The Landscape of Noncoding RNA in Pulmonary Hypertension

The transcriptome of pulmonary hypertension (PH) is complex and highly genetically heterogeneous, with noncoding RNA transcripts playing crucial roles. The majority of RNAs in the noncoding transcriptome are long noncoding RNAs (lncRNAs) with less circular RNAs (circRNAs), which are two characteristics gaining increasing attention in the forefront of RNA research field. These noncoding transcripts (especially lncRNAs and circRNAs) exert important regulatory functions in PH and emerge as potential disease biomarkers and therapeutic targets. Recent technological advancements have established great momentum for discovery and functional characterization of ncRNAs, which include broad transcriptome sequencing such as bulk RNA-sequence, single-cell and spatial transcriptomics, and RNA-protein/RNA interactions. In this review, we summarize the current research on the classification, biogenesis, and the biological functions and molecular mechanisms of these noncoding RNAs (ncRNAs) involved in the pulmonary vascular remodeling in PH. Furthermore, we highlight the utility and challenges of using these ncRNAs as biomarkers and therapeutics in PH.

Role of Long Non-Coding RNAs in Pulmonary Arterial Hypertension

Pulmonary arterial hypertension (PAH) is a debilitating condition of the pulmonary circulatory system that occurs in patients of all ages and if untreated, eventually leads to right heart failure and death. Despite existing medical treatment options that improve survival and quality of life, the disease remains incurable. Thus, there is an urgent need to develop novel therapies to treat this disease. Emerging evidence suggests that long non-coding RNAs (lncRNAs) play critical roles in pulmonary vascular remodeling and PAH. LncRNAs are implicated in pulmonary arterial endothelial dysfunction by modulating endothelial cell proliferation, angiogenesis, endothelial mesenchymal transition, and metabolism. LncRNAs are also involved in inducing different pulmonary arterial vascular smooth muscle cell phenotypes, such as cell proliferation, apoptosis, migration, regulation of the phenotypic switching, and cell cycle. LncRNAs are essential regulators of gene expression that affect various diseases at the chromatin, transcriptional, post-translational, and even post-translational levels. Here, we focus on the role of LncRNAs and their molecular mechanisms in the pathogenesis of PAH. We also discuss the current research challenge and potential biomarker and therapeutic potentials of lncRNAs in PAH.

mascRNA and its parent lncRNA MALAT1 promote proliferation and metastasis of hepatocellular carcinoma cells by activating ERK/MAPK signaling pathway

MALAT1-associated small cytoplasmic RNA (mascRNA) is a cytoplasmic tRNA-like small RNA derived from nucleus-located long noncoding RNA (lncRNA) metastasis-associated lung adenocarcinoma transcript 1 (MALAT1). While MALAT1 was extensively studied and was found to function in multiple cellular processes, including tumorigenesis and tumor progression, the role of mascRNA was largely unknown. Here we show that mascRNA is upregulated in multiple cancer cell lines and hepatocellular carcinoma (HCC) clinical samples. Using HCC cells as model, we found that mascRNA and its parent lncRNA MALAT1 can both promote cell proliferation, migration, and invasion in vitro. Correspondingly, both of them can enhance the tumor growth in mice subcutaneous tumor model and can promote metastasis by tail intravenous injection of HCC cells. Furthermore, we revealed that mascRNA and MALAT1 can both activate ERK/MAPK signaling pathway, which regulates metastasis-related genes and may contribute to the aggressive phenotype of HCC cells. Our results indicate a coordination in function and mechanism of mascRNA and MALAT1 during development and progress of HCC, and provide a paradigm for deciphering tRNA-like structures and their parent transcripts in mammalian cells.