LncRNA-ATB regulates epithelial-mesenchymal transition progression in pulmonary fibrosis via sponging miR-29b-2-5p and miR-34c-3p

Revisiting the role of MicroRNAs in the pathogenesis of idiopathic pulmonary fibrosis

Idiopathic pulmonary fibrosis (IPF) is a prevalent chronic pulmonary fibrosis disease characterized by alveolar epithelial cell damage, fibroblast proliferation and activation, excessive extracellular matrix deposition, and abnormal epithelial-mesenchymal transition (EMT), resulting in tissue remodeling and irreversible structural distortion. The mortality rate of IPF is very high, with a median survival time of 2-3 years after diagnosis. The exact cause of IPF remains unknown, but increasing evidence supports the central role of epigenetic changes, particularly microRNA (miRNA), in IPF. Approximately 10% of miRNAs in IPF lung tissue exhibit differential expression compared to normal lung tissue. Diverse miRNA phenotypes exert either a pro-fibrotic or anti-fibrotic influence on the progression of IPF. In the context of IPF, epigenetic factors such as DNA methylation and long non-coding RNAs (lncRNAs) regulate differentially expressed miRNAs, which in turn modulate various signaling pathways implicated in this process, including transforming growth factor-β1 (TGF-β1)/Smad, mitogen-activated protein kinase (MAPK), and phosphatidylinositol-3-kinase/protein kinase B (PI3K/AKT) pathways. Therefore, this review presents the epidemiology of IPF, discusses the multifaceted regulatory roles of miRNAs in IPF, and explores the impact of miRNAs on IPF through various pathways, particularly the TGF-β1/Smad pathway and its constituent structures. Consequently, we investigate the potential for targeting miRNAs as a treatment for IPF, thereby contributing to advancements in IPF research.

LncRNA MRAK052509 competitively adsorbs miR-204-3p to regulate silica dust-induced EMT process

Silicosis is a systemic disease caused by long-term inhalation of free SiO2 and retention in the lungs. At present, it is still the most important occupational health hazard disease in the world. Existing studies have shown that non-coding RNA can also participate in complex fibrosis regulatory networks. However, its role in regulating silicotic fibrosis is still unclear. In this study, we constructed a NR8383/RLE-6TN co-culture system to simulate the pathogenesis of silicosis in vitro. Design of miR-204-3p mimics and inhibitors to overexpress or downregulate miR-204-3p in RLE-6TN cells. Design of short hairpin RNA (sh-RNA) to downregulate MRAK052509 in RLE-6TN cells. The regulatory mechanism of miR-204-3p and LncRNA MRAK052509 on EMT process was studied by Quantitative real-time PCR, Western blotting, Immunofluorescence and Cell scratch test. The results revealed that miR-204-3p affects the occurrence of silica dust-induced cellular EMT process mainly through regulating TGF-βRΙ, a key molecule of TGF-β signaling pathway. In contrast, Lnc MRAK052509 promotes the EMT process in epithelial cells by competitively adsorbing miR-204-3p and reducing its inhibitory effect on the target gene TGF-βRΙ, which may influence the development of silicosis fibrosis. This study perfects the targeted regulation relationship between LncRNA MRAK052509, miR-204-3p and TGF-βRΙ, and may provide a new strategy for the study of the pathogenesis and treatment of silicosis.

LncRNA-mediated ceRNA network reveals the mechanism of action of Saorilao-4 decoction against pulmonary fibrosis

Introduction: Pulmonary fibrosis (PF), a type of interstitial pneumonia with complex etiology and high mortality, is characterized by progressive scarring of the alveolar interstitium and myofibroblastic lesions. In this study, we screened for potential biomarkers in PF and clarified the role of the lncRNA-miRNA-mRNA ceRNA network in the inhibitory effect of SRL-4 on PF. Methods: Healthy male SPF SD rats were randomly divided into three groups, namely, CON, MOD, and SRL-4. Gene Ontology and Kyoto Encyclopedia of Genes and Genomes enrichment analyses were performed to determine the biological functions of the target genes. A visualized lncRNA-miRNA-mRNA ceRNA network was constructed using Cytoscape, while key genes in the network were identified using the cytoNCA plugin. Results: Seventy-four differentially expressed lncRNAs and 118 differentially expressed mRNAs were identified. Gene Ontology analysis revealed that the target genes were mainly enriched in the cell membrane and in response to organic substances, while Kyoto Encyclopedia of Genes and Genomes analysis showed that the target genes were mainly enriched in the AMPK, PPAR, and cAMP signaling pathways. We elucidated a ceRNA axis, namely, Plcd3-OT1/rno-miR-150-3p/Fkbp5, with potential implications in PF. Key genes, such as AABR07051308.1-201, F2rl2-OT1, and LINC3337, may be important targets for the treatment of PF, while the AMPK, PPAR, and cAMP signaling pathways are potential key targets and important pathways through which SRL-4 mitigates PF. Conclusion: Our findings suggest that SRL-4 improves PF by regulating the lncRNA-miRNA-mRNA network.

Epigenetic Regulation of EMP/EMT-Dependent Fibrosis

Fibrosis represents a process characterized by excessive deposition of extracellular matrix (ECM) proteins. It often represents the evolution of pathological conditions, causes organ failure, and can, in extreme cases, compromise the functionality of organs to the point of causing death. In recent years, considerable efforts have been made to understand the molecular mechanisms underlying fibrotic evolution and to identify possible therapeutic strategies. Great interest has been aroused by the discovery of a molecular association between epithelial to mesenchymal plasticity (EMP), in particular epithelial to mesenchymal transition (EMT), and fibrogenesis, which has led to the identification of complex molecular mechanisms closely interconnected with each other, which could explain EMT-dependent fibrosis. However, the result remains unsatisfactory from a therapeutic point of view. In recent years, advances in epigenetics, based on chromatin remodeling through various histone modifications or through the intervention of non-coding RNAs (ncRNAs), have provided more information on the fibrotic process, and this could represent a promising path forward for the identification of innovative therapeutic strategies for organ fibrosis. In this review, we summarize current research on epigenetic mechanisms involved in organ fibrosis, with a focus on epigenetic regulation of EMP/EMT-dependent fibrosis.

miR-34c-5p inhibited fibroblast proliferation, differentiation and epithelial-mesenchymal transition in benign airway stenosis via MDMX/p53 pathway

Benign airway stenosis (BAS) means airway stenosis or obstruction that results from a variety of non-malignant factors, including tuberculosis, trauma, benign tumors, etc. In consideration of the currently limited research on microRNAs in BAS, this study aimed to explore the role and mechanism of miR-34c-5p in BAS. The expression of miR-34c-5p in BAS granulation tissues showed a significant down-regulation compared with the normal control group. Moreover, miR-34c-5p mimics suppressed the proliferation and differentiation of human bronchial fibroblasts (HBFs) and the epithelial-mesenchymal transition (EMT) of human bronchial epithelial cells (HBE). Conversely, miR-34c-5p inhibitors aggravated those effects. A dual-luciferase reporter assay confirmed that miR-34c-5p can target MDMX rather than Notch1. The over-expression of MDMX can reverse the inhibiting effect of miR-34c-5p on HBFs proliferation, differentiation and EMT. Furthermore, the expressions of tumor protein (p53) and PTEN were down-regulated following the over-expression of MDMX. In addition, the expressions of PI3K and AKT showed an up-regulation. In conclusion, miR-34c-5p was down-regulated in BAS and may inhibit fibroblast proliferation differentiation and EMT in BAS via the MDMX/p53 signaling axis. These findings expand the understanding of the role of miR-34c-5p and will help develop new treatment strategies for BAS.

Interaction between long noncoding RNA and microRNA in lung inflammatory diseases

BACKGROUND

Non-coding RNAs (ncRNAs) are a group of RNAs that cannot synthesize proteins, but are critical in gene expression regulation. Long non-coding RNAs (lncRNAs) and microRNAs (miRNAs), the two major family members, are intimately involved in controlling immune response, cell proliferation, apoptosis, differentiation and polarization, and cytokine secretion. Their interactions significantly influence lung inflammatory diseases and could be potential therapeutic targets.

OBJECTIVES

The review aims to elucidate the role of ncRNAs, especially the interactions between lncRNA and miRNA in lung diseases, including acute and chronic lung inflammatory diseases, as well as lung cancer. And provide novel insights into disease mechanisms and potential therapeutic methods.

METHODS

We conducted a comprehensive review of the latest studies on lncRNA and miRNA in lung inflammatory diseases. Our research involved searching through electronic databases like PubMed, Web of Science, and Scopus.

RESULTS

We explain the fundamental characteristics and functions of miRNA and lncRNA, their potential interaction mechanisms, and summarize the newly explorations on the role of lncRNA and miRNA interactions in lung inflammatory diseases.

CONCLUSIONS

Numerous lncRNAs and miRNAs have been found to partipicate in all stages of lung inflammatory diseases. While ncRNA-based therapies have been validated and developed, there remain challenges in developing more stable and effective drugs for clinical use.

New aspects of the epigenetic regulation of EMT related to pulmonary fibrosis

Pulmonary fibrosis is a chronic and progressive fibrotic disease that results in impaired gas exchange, ventilation, and eventual death. The pro-fibrotic environment is instigated by various factors, leading to the transformation of epithelial cells into myofibroblasts and/or fibroblasts that trigger fibrosis. Epithelial mesenchymal transition (EMT) is a biological process that plays a critical role in the pathogenesis of pulmonary fibrosis. Epigenetic regulation of tissue-stromal crosstalk involving DNA methylation, histone modifications, non-coding RNA, and chromatin remodeling plays a key role in the control of EMT. The review investigates the epigenetic regulation of EMT and its significance in pulmonary fibrosis.

TGF-β as A Master Regulator of Aging-Associated Tissue Fibrosis

Fibrosis is the abnormal accumulation of extracellular matrix proteins such as collagen and fibronectin. Aging, injury, infections, and inflammation can cause different types of tissue fibrosis. Numerous clinical investigations have shown a correlation between the degree of liver and pulmonary fibrosis in patients and telomere length and mitochondrial DNA content, both of which are signs of aging. Aging involves the gradual loss of tissue function over time, which results in the loss of homeostasis and, ultimately, an organism's fitness. A major feature of aging is the accumulation of senescent cells. Senescent cells abnormally and continuously accumulate in the late stages of life, contributing to age-related fibrosis and tissue deterioration, among other aging characteristics. Furthermore, aging generates chronic inflammation, which results in fibrosis and decreases organ function. This finding suggests that fibrosis and aging are closely related. The transforming growth factor-beta (TGF-β) superfamily plays a crucial role in the physiological and pathological processes of aging, immune regulation, atherosclerosis, and tissue fibrosis. In this review, the functions of TGF-β in normal organs, aging, and fibrotic tissues is discussed: TGF-β signalling is altered with age and is an indicator of pathology associated with tissue fibrosis. In addition, this review discusses the potential targeting of noncoding.

The therapeutic effect of exosomal lncRNA MSTRG.91634.7 on mitochondrial dysfunction during SiO2-induced lung fibrosis

Long-term silica (SiO₂) exposure led to irreversible lung fibrosis, in which epithelial-mesenchymal transition (EMT) played an essential role. A novel lncRNA MSTRG.91634.7 in the peripheral exosomes of silicosis patients was reported in our previous study, which could remold the pathological process of silicosis. However, whether its regulatory role on the development of silicosis was related to EMT process is unclear, and its mechanism remains to be further studied. In this study, up-regulating lncRNA MSTRG91634.7 restricted SiO₂-activated EMT and restored mitochondrial homeostasis binding to PINK1 in vitro. Moreover, overexpressing PINK1 could inhibit SiO₂-activated EMT in pulmonary inflammation and fibrosis in mice. Meanwhile, PINK1 contributed to restoring the SiO₂-induced mitochondrial dysfunction in mice lung. Our results revealed that exosomal lncRNA MSTRG.91634.7 from macrophages could restore mitochondrial homeostasis to restrict the SiO₂-activated EMT by binding to PINK1 during pulmonary inflammation and fibrosis due to SiO₂ exposure.

Jaceosidin inhibits the progression and metastasis of NSCLC by regulating miR-34c-3p/Integrin α2β1 axis

Non-coding RNAs are crucial for cancer progression, among which miR-34c-3p has been demonstrated to be a tumor suppressor in non-small cell lung cancer (NSCLC). In this study, we attempt to identify flavonoids that can up-regulate miR-34c-3p expression, evaluate the anticancer activity of the flavonoids and explore its underlying mechanism in NSCLC cells. Six flavonoids were screened by RT-qPCR and we found that jaceosidin significantly increased miR-34c-3p expression in A549 cells. We found that jaceosidin inhibited the proliferation, migration and invasion of A549 and H1975 cells in a dose-relevant manner, indicated by cell counting kit (CCK-8) assay, wound healing assay, transwell assay and EdU assay, we observed that jaceosidin inhibited the proliferation, migration and invasion of A549 and H1975 cells in a dose-relevant manner. Further research suggested that miR-34c-3p bound to the transcriptome of integrin α2β1 and then inhibited its expression, leading to the inhibitory effect on the migration and invasion of NSCLC. Our study sheds some light on anti-tumor of jaceosidin and provides a potential lead compound for NSCLC therapy.

Aryl Hydrocarbon Receptor Activation Ameliorates Acute Respiratory Distress Syndrome through Regulation of Th17 and Th22 Cells in the Lungs

Acute respiratory distress syndrome (ARDS) is triggered by a variety of insults, including bacterial and viral infections, and this leads to high mortality. While the role of the aryl hydrocarbon receptor (AhR) in mucosal immunity is being increasingly recognized, its function during ARDS is unclear. In the current study, we investigated the role of AhR in LPS-induced ARDS. AhR ligand, indole-3-carbinol (I3C), attenuated ARDS which was associated with a decrease in CD4+ RORγt +IL-17a+IL-22+ pathogenic Th17 cells, but not CD4+RORγt +IL-17a+IL-22- homeostatic Th 17 cells, in the lungs. AhR activation also led to a significant increase in CD4+IL-17a-IL-22+ Th22 cells. I3C-mediated Th22 cell expansion was dependent on the AhR expression on RORγt+ cells. AhR activation downregulated miR-29b-2-5p in immune cells from the lungs, which in turn downregulated RORc expression and upregulated IL-22. Collectively, the current study suggests that AhR activation can attenuate ARDS and may serve as a therapeutic modality by which to treat this complex disorder. IMPORTANCE Acute respiratory distress syndrome (ARDS) is a type of respiratory failure that is triggered by a variety of bacterial and viral infections, including the coronavirus SARS-CoV2. ARDS is associated with a hyperimmune response in the lungs that which is challenging to treat. Because of this difficulty, approximately 40% of patients with ARDS die. Thus, it is critical to understand the nature of the immune response that is functional in the lungs during ARDS as well as approaches by which to attenuate it. AhR is a transcription factor that is activated by a variety of endogenous and exogenous environmental chemicals as well as bacterial metabolites. While AhR has been shown to regulate inflammation, its role in ARDS is unclear. In the current study, we provide evidence that AhR activation can attenuate LPS-mediated ARDS through the activation of Th22 cells in the lungs, which are regulated through miR-29b-2-5p. Thus, AhR can be targeted to attenuate ARDS.

Comparing species-different responses in pulmonary fibrosis research: Current understanding of in vitro lung cell models and nanomaterials

Pulmonary fibrosis (PF) is a chronic, irreversible lung disease that is typically fatal and characterized by an abnormal fibrotic response. As a result, vast areas of the lungs are gradually affected, and gas exchange is impaired, making it one of the world's leading causes of death. This can be attributed to a lack of understanding of the onset and progression of the disease, as well as a poor understanding of the mechanism of adverse responses to various factors, such as exposure to allergens, nanomaterials, environmental pollutants, etc. So far, the most frequently used preclinical evaluation paradigm for PF is still animal testing. Nonetheless, there is an urgent need to understand the factors that induce PF and find novel therapeutic targets for PF in humans. In this regard, robust and realistic in vitro fibrosis models are required to understand the mechanism of adverse responses. Over the years, several in vitro and ex vivo models have been developed with the goal of mimicking the biological barriers of the lung as closely as possible. This review summarizes recent progress towards the development of experimental models suitable for predicting fibrotic responses, with an emphasis on cell culture methods, nanomaterials, and a comparison of results from studies using cells from various species.

The emerging role of epigenetic regulation in the progression of silicosis

Silicosis is one of the most severe occupational diseases worldwide and is characterized by silicon nodules and diffuse pulmonary fibrosis. However, specific treatments for silicosis are still lacking at present. Therefore, elucidating the pathogenesis of silicosis plays a significant guiding role for its treatment and prevention. The occurrence and development of silicosis are accompanied by many regulatory mechanisms, including epigenetic regulation. The main epigenetic regulatory mechanisms of silicosis include DNA methylation, non-coding RNA (ncRNA), and histone modifications. In recent years, the expression and regulation of genes related to silicosis have been explored at epigenetic level to reveal its pathogenesis further, and the identification of aberrant epigenetic markers provides new biomarkers for prediction and diagnosis of silicosis. Here, we summarize the studies on the role of epigenetic changes in the pathogenesis of silicosis to give some clues for finding specific therapeutic targets for silicosis.

The silencing of lnc-NONHSAT071210 suppresses the proliferation, fibrosis, migration, and invasion of TGFβ1-treated lung epithelial cells

Background

Pulmonary fibrosis, which is a frequent manifestation of connective tissue disease (CTD), is a leading cause of morbidity and mortality. However, the role of long non-coding ribonucleic acids (lncRNAs) in CTD-associated pulmonary fibrosis requires clarification. This study sought to examine the effects of lnc-NONHSAT071210 on the phenotypes of transforming growth factor β1 (TGFβ1)-treated lung epithelial cells.

Methods

The GeneChip was used to identify differentially expressed lncRNAs in CTD-associated pulmonary fibrosis patients. After lnc-NONHSAT071210 was knocked down in the TGFβ1-challenged lung epithelial cells, cell viability, cell cycle, migration, and invasion were estimated by Cell Counting Kit-8 assays, a flow cytometry analysis, wound-healing assays, and transwell assays, respectively. The expression and levels of the fibrosis-associated factors were examined by enzyme-linked immunosorbent assays, RT-qPCR, and western blots.

Results

The expression of the top 7 most significantly upregulated lncRNAs in the CTD-associated pulmonary fibrosis patients was depicted in a heat map and examined by reverse transcription-quantitative polymerase chain reaction (RT-qPCR). The results showed that the expression of lnc-NONHSAT071210 was significantly increased in the tissues of the CTD-associated pulmonary fibrosis patients (P<0.001). The silencing of Lnc-NONHSAT071210 suppressed proliferation, migration, and invasion in the TGFβ1-exposed alveolar epithelial cells (P<0.001).

Conclusions

Thus, lnc-NONHSAT071210 expression was increased in the tissues of the CTD-associated pulmonary fibrosis patients and TGFβ1-treated lung epithelial cells, and TGFβ1-induced lung epithelial cell injury was alleviated by impeding the expression of lnc-NONHSAT071210.

Construction and validation of an eight pyroptosis-related lncRNA risk model for breast cancer

OBJECTIVE

We developed a risk model based on pyroptosis-related long non-coding RNAs (lncRNAs) and assessed its prognostic value and clinical significance in breast cancer (BRCA).

METHODS

BRCA RNA sequencing data with corresponding clinical information were retrieved from The Cancer Genome Atlas (TCGA) database. Univariate Cox regression analysis was used to examine correlations between prognosis of BRCA patients and the expression levels of pyroptosis-related lncRNAs. A prognostic model was developed and validated by identifying the correlation of risk scores with tumor immune infiltration and immune cell function through immune response analysis. Functional analyses of focal dysfunction-related lncRNA were also carried out. Lastly, single sample gene set enrichment analysis (ssGSEA) was conducted to determine the differences in immune responses between the low- and high-risk groups.

RESULTS

We divided the TCGA-BRCA dataset into 3 clusters by consensus clustering, and identified 11 pyroptosis-related lncRNAs that are differentially expressed between tumors and normal tissues. In addition, we determined if PD-L1 expression is associated with clustering and gene expression. The list was further narrowed down to eight pyroptosis-related lncRNAs and their regression coefficients were obtained through LASSO regression analysis. The relative proportion of 22 different immune cells in the BRCA microenvironment was determined using the CIBERSORT algorithm to explore the indicative effects of risk score on the tumor microenvironment (TME). We found that the resting mast cells, M0, and M2 macrophages were positively correlated with the risk scores.

CONCLUSION

The potential role of pyroptosis-related lncRNAs in BRCA prognosis may be exploited as a treatment target for patients with BRCA.

Circulating microRNA profiling is altered in the acute respiratory distress syndrome related to SARS-CoV-2 infection

One of the hallmarks of SARS-CoV-2 infection is an induced immune dysregulation, in some cases resulting in cytokine storm syndrome and acute respiratory distress syndrome (ARDS). Several physiological parameters are altered as a result of infection and cytokine storm. Among them, microRNAs (miRNAs) might reflect this poor condition since they play a significant role in immune cellular performance including inflammatory responses. Circulating miRNAs in patients who underwent ARDS and needed mechanical ventilation (MV+; n = 15) were analyzed by next generation sequencing in comparison with patients who had COVID-19 poor symptoms but without intensive care unit requirement (MV−; n = 13). A comprehensive in silico analysis by integration with public gene expression dataset and pathway enrichment was performed. Whole miRNA sequencing identified 170 differentially expressed miRNAs between patient groups. After the validation step by qPCR in an independent sample set (MV+  = 10 vs. MV− = 10), the miR-369-3p was found significantly decreased in MV+ patients (Fold change − 2.7). After integrating with gene expression results from COVID-19 patients, the most significant GO enriched pathways were acute inflammatory response, regulation of transmembrane receptor protein Ser/Thr, fat cell differentiation, and regulation of biomineralization and ossification. In conclusion, miR-369-3p was altered in patients with mechanical ventilation requirement in comparison with COVID-19 patients without this requirement. This miRNA is involved in inflammatory response which it can be considered as a prognosis factor for ARDS in COVID-19 patients.

Identification of a Twelve Epithelial-Mesenchymal Transition-Related lncRNA Prognostic Signature in Kidney Clear Cell Carcinoma

Background

Epithelial-mesenchymal transition (EMT) plays a vital role in tumor metastasis and drug resistance. It has been reported that EMT is regulated by several long noncoding RNAs (lncRNAs). We aimed to identify EMT-related lncRNAs and develop an EMT-related lncRNA prognostic signature in kidney renal clear cell carcinoma (KIRC).

Materials and Methods

In total, 530 ccRCC patients with 611 transcriptome profiles were included in this study. We first identified differentially expressed EMT-related lncRNAs. Then, all the samples with transcriptional data and clinical survival information were randomly split into training/test sets at a ratio of 1 : 1. Accordingly, we further developed a twelve differentially expressed EMT-related lncRNA prognostic signature in the training set. Following this, risk analysis, survival analysis, subgroup analysis, and the construction of the ROC curves were applied to verify the efficacy of the signature in the training set, test set, and all patients. Besides, we further investigated the differential immune infiltration, immune checkpoint expression, and immune-related functions between high-risk patients. Finally, we explored the different drug responses to targeted therapy (sunitinib and sorafenib) and immunotherapy (anti-PD1 and anti-CTLA4).

Results

A twelve differentially expressed EMT-related lncRNA prognostic signature performed superior in predicting the overall survival of KIRC patients. High-risk patients were observed with a significantly higher immune checkpoint expression and showed better responses to the targeted therapy and immunotherapy.

Conclusions

Our study demonstrates that the twelve differentially expressed EMT-related lncRNA prognostic signature could act as an efficient prognostic indicator for KIRC, which also contributes to the decision-making of the further treatment.

Long Noncoding RNA LOC550643 Acts as an Oncogene in the Growth Regulation of Colorectal Cancer Cells

Long noncoding RNAs play a key role in the progression of colorectal cancer (CRC). However, the role and mechanism of LOC550643 in CRC cell growth and metastasis remain largely unknown. In this study, we assessed the clinical impacts of LOC550643 on CRC through the analysis of The Cancer Genome Atlas database, which revealed the significant upregulation of LOC550643 in CRC. Moreover, the high expression of LOC550643 was associated with poor survival in patients with CRC (p = 0.001). Multivariate Cox regression analysis indicated that LOC550643 overexpression was an independent prognostic factor for shorter overall survival in patients with CRC (adjusted hazard ratio, 1.90; 95% confidence interval, 1.21-3.00; p = 0.006). A biological function analysis revealed that LOC550643 knockdown reduced colon cancer cell growth by hindering cell cycle progression. In addition, LOC550643 knockdown significantly induced cell apoptosis through the inhibition of signaling activity in phosphoinositide 3-kinases. Moreover, LOC550643 knockdown contributed to the inhibition of migration and invasion ability in colon cancer cells. Furthermore, miR-29b-2-5p interacted with the LOC550643 sequence. Ectopic miR-29b-2-5p significantly suppressed colon cancer cell growth and motility and induced cell apoptosis. Our findings suggest that, LOC550643-miR-29b-2-5p axis was determined to participate in the growth and metastasis of colon cancer cells; this could serve as a useful molecular biomarker for cancer diagnosis and as a potential therapeutic target for CRC.

Detection and analysis of long noncoding RNA expression profiles related to epithelial-mesenchymal transition in keloids

BACKGROUND

The role of epithelial-mesenchymal transition (EMT) in the pathogenesis of keloids is currently raising increasing attention. Long noncoding RNAs (lncRNAs) govern a variety of biological processes, such as EMT, and their dysregulation is involved in many diseases including keloid disease. The aim of this study was to identify differentially expressed EMT-related lncRNAs in keloid tissues versus normal tissues and to interpret their functions.

RESULTS

Eleven lncRNAs and 16 mRNAs associated with EMT were identified to have differential expression between keloid and normal skin tissues (fold change > 1.5, P < 0.05). Gene Ontology (GO) analysis showed that these differentially expressed mRNAs functioned in the extracellular matrix, protein binding, the positive regulation of cellular processes, the Set1C/COMPASS complex and histone acetyltransferase activity. Kyoto Encyclopedia of Genes and Genomes (KEGG) analysis demonstrated that these mRNAs are involved in pathways in cancer. The lncRNA, XLOC_000587 may promote cell proliferation and migration by enhancing the expression of ENAH, while AF268386 may facilitate the invasive growth of keloids by upregulating DDR2.

CONCLUSIONS

We characterized the differential expression profiles of EMT-related lncRNAs and mRNAs in keloids, which may contribute to preventing the occurrence and development of keloids by targeting the corresponding signaling pathways. These lncRNAs and mRNAs may provide biomarkers for keloid diagnosis and serve as potential targets for the treatment of this disease.

The single nucleotide polymorphism rs1814521 in long non-coding RNA ADGRG3 associates with the susceptibility to silicosis: a multi-stage study

Background

This study aimed to evaluate the correlation between long non-coding RNA (lncRNA)-related single nucleotide polymorphisms (SNPs) and susceptibility to silicosis.

Methods

First, RNA-sequencing (RNA-seq) data were comprehensively analyzed in the peripheral blood lymphocytes of eight participants (four silicosis cases and four healthy controls) exposed to silica dust to identify differentially expressed lncRNAs (DE-lncRNAs). The functional SNPs in the identified DE-lncRNAs were then identified using several databases. Finally, the association between functional SNPs and susceptibility to silicosis was evaluated by a two-stage case-control study. The SNPs of 155 silicosis cases and 141 healthy silica-exposed controls were screened by genome-wide association study (GWAS), and the candidate SNPs of 194 silicosis cases and 235 healthy silica-exposed controls were validated by genotyping using the improved Mutiligase Detection Reaction (iMLDR) system.

Results

A total of 76 DE-lncRNAs were identified by RNA-seq data analysis (cut-offs: fold change > 2 or fold change < 0.5, P < 0.05), while 127 functional SNPs among those 76 DE-lncRNAs were identified through multiple public databases. Furthermore, five SNPs were found to be significantly correlated with the risk of silicosis by GWAS screening (P < 0.05), while the results of GWAS and iMLDR validation indicated that the variant A allele of rs1814521 was associated with a reduced risk of silicosis (OR = 0.76, 95% CI = 0.62–0.94, P = 0.011).

Conclusion

The presence of the SNP rs1814521 in the lncRNA ADGRG3 is associated with susceptibility to silicosis. Moreover, ADGRG3 was found to be lowly expressed in silicosis cases. The underlying biological mechanisms by which lncRNA ADGRG3 and rs1814521 regulate the development of silicosis need further study.

Supplementary information

The online version contains supplementary material available at https://doi.org/10.1265/ehpm.21-00338.

LINC02381, a sponge of miR-21, weakens osteogenic differentiation of hUC-MSCs through KLF12-mediated Wnt4 transcriptional repression

INTRODUCTION

Human umbilical cord blood-derived MSCs (hUC-MSCs) have the potential to differentiate into osteoblasts. This study investigated the function and potential mechanisms of a novel lncRNA LINC02381 in hUC-MSC osteogenic differentiation.

MATERIALS AND METHODS

hUC-MSCs were maintained in osteogenic differentiation medium. RT-qPCR assay was performed to assess LINC02381 expression. Alizarin Red S (ARS) and alkaline phosphatase (ALP) staining were performed to evaluate osteogenic differentiation. The interaction between miR-21 and LINC0238/KLF12 was determined by luciferase reporter and RNA immunoprecipitation (RIP) assays. Chromatin immunoprecipitation (ChIP) assay was used to confirm the transcriptional regulation of KLF12 on Wnt4 promoter. The nuclear translocation of β-catenin was evaluated using immunofluorescence. hUC-MSCs seeded on Bio-Oss Collagen scaffolds were transplanted into nude mice to assess in vivo osteogenesis. Bone formation was observed by H&E and Masson's trichrome staining. OSX and OPN levels were assessed by immunohistochemistry.

RESULTS

LINC02381 was up-regulated in the clinical samples of osteoporotic patients. However, LINC02381 expression was reduced during osteogenic differentiation of hUC-MSCs. Enforced expression of LINC02381 suppressed the osteogenic differentiation of hUC-MSCs. Mechanistically, LINC02381 sponged miR-21 to enhance KLF12 expression, which led to the inactivation of Wnt/β-catenin signaling pathway. Furthermore, miR-21 mimics or KLF12 silencing counteracted LINC02381-induced inhibition of osteogenic differentiation, whereas IWP-4 (an inhibitor of Wnt pathway) abolished this effect.

CONCLUSION

In summary, LINC02381 repressed osteogenic differentiation of hUS-MSCs through sponging miR-21 to enhance KLF12-mediated inactivation of Wnt/β-catenin pathway, indicating that LINC02381 might be a therapeutic target for osteoporosis.

Pulmonary fibrosis from molecular mechanisms to therapeutic interventions: lessons from post-COVID-19 patients

Pulmonary fibrosis (PF) is characterised by several grades of chronic inflammation and collagen deposition in the interalveolar space and is a hallmark of interstitial lung diseases (ILDs). Recently, infectious agents have emerged as driving causes for PF development; however, the role of viral/bacterial infections in the initiation and propagation of PF is still debated. In this context, the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), the virus responsible for the current coronavirus disease 2019 (COVID-19) pandemic, has been associated with acute respiratory distress syndrome (ARDS) and PF development. Although the infection by SARS-CoV-2 can be eradicated in most cases, the development of fibrotic lesions cannot be precluded; furthermore, whether these lesions are stable or progressive fibrotic events is still unknown. Herein, an overview of the main molecular mechanisms driving the fibrotic process together with the currently approved and newly proposed therapeutic solutions was given. Then, the most recent data that emerged from post-COVID-19 patients was discussed, in order to compare PF and COVID-19-dependent PF, highlighting shared and specific mechanisms. A better understanding of PF aetiology is certainly needed, also to develop effective therapeutic strategies and COVID-19 pathology is offering one more chance to do it. Overall, the work reported here could help to define new approaches for therapeutic intervention in the diversity of the ILD spectrum.

Metformin attenuates silica-induced pulmonary fibrosis via AMPK signaling

Background

Silicosis is one of the most common occupational pulmonary fibrosis caused by respirable silica-based particle exposure, with no ideal drugs at present. Metformin, a commonly used biguanide antidiabetic agent, could activate AMP-activated protein kinase (AMPK) to exert its pharmacological action. Therefore, we sought to investigate the role of metformin in silica-induced lung fibrosis.

Methods

The anti-fibrotic role of metformin was assessed in 50 mg/kg silica-induced lung fibrosis model. Silicon dioxide (SiO₂)-stimulated lung epithelial cells/macrophages and transforming growth factor-beta 1 (TGF-β1)-induced differentiated lung fibroblasts were used for in vitro models.

Results

At the concentration of 300 mg/kg in the mouse model, metformin significantly reduced lung inflammation and fibrosis in SiO₂-instilled mice at the early and late fibrotic stages. Besides, metformin (range 2–10 mM) reversed SiO₂-induced cell toxicity, oxidative stress, and epithelial-mesenchymal transition process in epithelial cells (A549 and HBE), inhibited inflammation response in macrophages (THP-1), and alleviated TGF-β1-stimulated fibroblast activation in lung fibroblasts (MRC-5) via an AMPK-dependent pathway.

Conclusions

In this study, we identified that metformin might be a potential drug for silicosis treatment.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12967-021-03036-5.

LncRNA-ATB regulates epithelial-mesenchymal transition progression in pulmonary fibrosis via sponging miR-29b-2-5p and miR-34c-3p

Dysregulation of non‐coding RNAs (ncRNAs) has been proved to play pivotal roles in epithelial‐mesenchymal transition (EMT) and fibrosis. We have previously demonstrated the crucial function of long non‐coding RNA (lncRNA) ATB in silica‐induced pulmonary fibrosis‐related EMT progression. However, the underlying molecular mechanism has not been fully elucidated. Here, we verified miR‐29b‐2‐5p and miR‐34c‐3p as two vital downstream targets of lncRNA‐ATB. As opposed to lncRNA‐ATB, a significant reduction of both miR‐29b‐2‐5p and miR‐34c‐3p was observed in lung epithelial cells treated with TGF‐β1 and a murine silicosis model. Overexpression miR‐29b‐2‐5p or miR‐34c‐3p inhibited EMT process and abrogated the pro‐fibrotic effects of lncRNA‐ATB in vitro. Further, the ectopic expression of miR‐29b‐2‐5p and miR‐34c‐3p with chemotherapy attenuated silica‐induced pulmonary fibrosis in vivo. Mechanistically, TGF‐β1‐induced lncRNA‐ATB accelerated EMT as a sponge of miR‐29b‐2‐5p and miR‐34c‐3p and shared miRNA response elements with MEKK2 and NOTCH2, thus relieving these two molecules from miRNA‐mediated translational repression. Interestingly, the co‐transfection of miR‐29b‐2‐5p and miR‐34c‐3p showed a synergistic suppression effect on EMT in vitro. Furthermore, the co‐expression of these two miRNAs by using adeno‐associated virus (AAV) better alleviated silica‐induced fibrogenesis than single miRNA. Approaches aiming at lncRNA‐ATB and its downstream effectors may represent new effective therapeutic strategies in pulmonary fibrosis.