Lung fibroblasts express a miR-19a-19b-20a sub-cluster to suppress TGF-β-associated fibroblast activation in murine pulmonary fibrosis

Mechanomemory of pulmonary fibroblasts demonstrates reversibility of transcriptomics and contraction phenotypes

Fibroblasts are cells responsible for producing extracellular matrix (ECM) components, which provides physical support for organs. Although these mesenchymal cells are responsive to mechanical cues in their environment, the permanence of these mechanophenotypes is not well defined. We investigated the mechanomemory of lung fibroblasts and determined how switching culture conditions modulate cell responses and function. Primary murine lung fibroblasts were isolated and cultured on 2D tissue culture plates or within 3D collagen hydrogels and were then passaged within the same or opposite culture condition to assess changes in gene expression, protein production, fibroblast subpopulation, contractile behavior, and traction forces. Compared to fibroblasts isolated on 2D tissue culture plates, fibroblasts within 3D hydrogels exhibited a decreased activation phenotype including reduced contraction profiles, diminished cell traction forces and decreased αSMA gene expression. Cells initially isolated via 2D culture and then cultured in 3D hydrogels exhibited a reversal in activation phenotype as measured by gene expression and contraction profiles. Bulk RNAseq identified groups of genes that exhibit reversible and non-reversable expression patterns. Overall, these findings indicate that lung fibroblasts have a mechanical memory that is altered by culture condition and can be reversible through precondition of cells within a softer 3D microenvironment.

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.

Eggshell membrane and its major component lysozyme and ovotransferrin enhance the secretion of decorin as an endogenous antifibrotic mediator from lung fibroblasts and ameliorate bleomycin-induced pulmonary fibrosis

Aging is a high-risk factor for obstructive and fibrotic lung diseases. Fibrotic lung disease leading to decreased lung function is characterized by interstitial remodeling and tissue scarring (sclerosis), with destruction of alveoli and excess deposition of type I collagen, an extracellular matrix component secreted by fibroblasts. Therefore, regulating transforming growth factor-β (TGF-β) as a profibrotic signal is essential to suppress pulmonary fibrosis. In pulmonary fibrosis, TGF-β signaling is mediated by Smad and YAP/TAZ, and TAZ linked to the pathology of pulmonary function is observed in lung fibroblasts from patients with idiopathic pulmonary fibrosis. Although fibrosis is thought to be irreversible, it is an interventional condition. Decorin (DCN) blocks TGF-β signaling in pulmonary fibrosis, although there are no cellular pharmacological methods to stimulate DCN secretion. We previously showed that chicken eggshell membrane (ESM, a well-known wound-healing material) promotes dcn gene expression in fibroblasts. In this study, we investigated whether ESM stimulates DCN secretion as an endogenous mediator and ameliorates pulmonary fibrosis. Decorin secretion was significantly enhanced in the WI-38 lung fibroblast culture supernatants supplemented with ESM. This effect was increased with major component lysozyme and maximally promoted in experiments with lysozyme and ovotransferrin (the two main proteins in soluble ESM) at a 16:1 concentration ratio, the ratio in the ESM extract. Decorin secretion by ESM modulates TGF-β signaling in lung fibroblasts by reducing TAZ and pSmad2 nuclear localization. Decorin siRNA experiments confirmed that nuclear localization of TAZ is DCN-dependent. In a mouse model of bleomycin-induced pulmonary fibrosis, all fibrotic markers of ESM treatment group such as hydroxyproline (a collagen deposition marker), and both evaluation of fibrosis density by automated thresholding of picrosirius red-stained lung tissue scan images and Ashcroft fibrosis scores, and also the nuclear localization of TAZ were reduced after 2 weeks compared with control group. Furthermore, long-term (22 week) ESM consumption by healthy individuals significantly improved vital capacity and the forced expiratory volume in 1 s to forced vital capacity ratio (FEV1/FVC). This study reveals that ESM, a well-established wound-healing material, may be a potential preventive medicine for pulmonary fibrosis.

Unveiling the Cutting-Edge Impact of Polarized Macrophage-Derived Extracellular Vesicles and MiRNA Signatures on TGF-β Regulation within Lung Fibroblasts

Depending on local cues, macrophages can polarize into classically activated (M1) or alternatively activated (M2) phenotypes. This study investigates the impact of polarized macrophage-derived Extracellular Vesicles (EVs) (M1 and M2) and their cargo of miRNA-19a-3p and miRNA-425-5p on TGF-β production in lung fibroblasts. EVs were isolated from supernatants of M0, M1, and M2 macrophages and quantified using nanoscale flow cytometry prior to fibroblast stimulation. The concentration of TGF-β in fibroblast supernatants was measured using ELISA assays. The expression levels of miRNA-19a-3p and miRNA-425-5p were assessed via TaqMan-qPCR. TGF-β production after stimulation with M0-derived EVs and with M1-derived EVs increased significantly compared to untreated fibroblasts. miRNA-425-5p, but not miRNA-19a-3p, was significantly upregulated in M2-derived EVs compared to M0- and M1-derived EVs. This study demonstrates that EVs derived from both M0 and M1 polarized macrophages induce the production of TGF-β in fibroblasts, with potential regulation by miRNA-425-5p.

Results from omic approaches in rat or mouse models exposed to inhaled crystalline silica: a systematic review

BACKGROUND

Crystalline silica (cSiO2) is a mineral found in rocks; workers from the construction or denim industries are particularly exposed to cSiO2 through inhalation. cSiO2 inhalation increases the risk of silicosis and systemic autoimmune diseases. Inhaled cSiO2 microparticles can reach the alveoli where they induce inflammation, cell death, auto-immunity and fibrosis but the specific molecular pathways involved in these cSiO2 effects remain unclear. This systematic review aims to provide a comprehensive state of the art on omic approaches and exposure models used to study the effects of inhaled cSiO2 in mice and rats and to highlight key results from omic data in rodents also validated in human.

METHODS

The protocol of systematic review follows PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-Analyses) guidelines. Eligible articles were identified in PubMed, Embase and Web of Science. The search strategy included original articles published after 1990 and written in English which included mouse or rat models exposed to cSiO2 and utilized omic approaches to identify pathways modulated by cSiO2. Data were extracted and quality assessment was based on the SYRCLE's Risk of Bias tool for animal studies.

RESULTS

Rats and male rodents were the more used models while female rodents and autoimmune prone models were less studied. Exposure of animals were both acute and chronic and the timing of outcome measurement through omics approaches were homogeneously distributed. Transcriptomic techniques were more commonly performed while proteomic, metabolomic and single-cell omic methods were less utilized. Immunity and inflammation were the main domains modified by cSiO2 exposure in lungs of mice and rats. Less than 20% of the results obtained in rodents were finally verified in humans.

CONCLUSION

Omic technics offer new insights on the effects of cSiO2 exposure in mice and rats although the majority of data still need to be validated in humans. Autoimmune prone model should be better characterised and systemic effects of cSiO2 need to be further studied to better understand cSiO2-induced autoimmunity. Single-cell omics should be performed to inform on pathological processes induced by cSiO2 exposure.

Molecular and Cellular Mechanism of Action of Chrysotile Asbestos in MRC5 Cell Line

Asbestos is a known carcinogen; however, the influence of chrysotile asbestos on the development of tumor-related diseases remains a subject of intense debate within the scientific community. To analyze the effect of asbestos, we conducted a study using the MRC5 cell line. We were able to demonstrate that chrysotile asbestos stimulated the production of reactive oxygen species (ROS), leading to cell death and DNA damage in the MRC5 cell line, using various techniques such as ROS measurement, comet assay, MTT assay, and qPCR. In addition, we found that chrysotile asbestos treatment significantly increased extracellular mitochondrial DNA levels in the culture medium and induced significant changes in the expression profile of several miRNAs, which was the first of its kind. Thus, our research highlights the importance of studying the effects of chrysotile asbestos on human health and reveals multiple adverse effects of chrysotile asbestos.

Hsa-miR-379 down-regulates Rac1/MLK3/JNK/AP-1/Collagen I cascade reaction by targeting connective tissue growth factor in human alveolar basal epithelial A549 cells

OBJECTIVE

This study was aimed to screen and identify miRNAs that could regulate human CTGF gene and downstream cascade reaction Rac1/MLK3/JNK/AP-1/Collagen I by bioinformatics and experimental means.

METHODS

TargetScan and Tarbase were used to predict miRNAs that may have regulatory effects on human CTGF gene. The dual-luciferase reporter gene assay was employed to verify the results obtained in bioinformatics. Human alveolar basal epithelial A549 cells were exposed to silica (SiO₂) culture medium for 24 h to establish an in vitro model of pulmonary fibrosis, and bleomycin (BLM) of 100 ng/mL was used as a positive control. The miRNA and mRNA expression levels were determined by RT-qPCR, and the protein levels were measured by western blot in hsa-miR-379-3p overexpression group or not.

RESULTS

A total of 9 differentially expressed miRNAs that might regulate the human CTGF gene were predicted. Hsa-miR-379-3p and hsa-miR-411-3p were selected for the subsequent experiments. The results of the dual-luciferase reporter assay showed that hsa-miR-379-3p could bind to CTGF, but hsa-miR-411-3p could not. Compared with the control group, SiO₂ exposure (25 and 50 μg/mL) could significantly reduce the expression level of hsa-miR-379-3p in A549 cells. SiO₂ exposure (50 μg/mL) could significantly increase the mRNA expression levels of CTGF, Collagen I, Rac1, MLK3, JNK, AP1, and VIM in A549 cells, while CDH1 level was significantly decreased. Compared with SiO₂ + NC group, the mRNA expression levels of CTGF, Collagen I, Rac1, MLK3, JNK, AP1, and VIM were significantly decreased, and CDH1 level was significantly higher when hsa-miR-379-3p was overexpressed. At the same time, overexpression of hsa-miR-379-3p improved the protein levels of CTGF, Collagen I, c-Jun and phospho-c-Jun, JNK1 and phospho-JNK1 significantly compared with SiO₂ + NC group.

CONCLUSION

Hsa-miR-379-3p was demonstrated for the first time that could directly target and down-regulate human CTGF gene, and further affect the expression levels of key genes and proteins in Rac1/MLK3/JNK/AP-1/Collagen I cascade reaction.

Dual Role of Fibroblasts Educated by Tumour in Cancer Behavior and Therapeutic Perspectives

Tumours are complex systems with dynamic interactions between tumour cells, non-tumour cells, and extracellular components that comprise the tumour microenvironment (TME). The majority of TME's cells are cancer-associated fibroblasts (CAFs), which are crucial in extracellular matrix (ECM) construction, tumour metabolism, immunology, adaptive chemoresistance, and tumour cell motility. CAF subtypes have been identified based on the expression of protein markers. CAFs may act as promoters or suppressors in tumour cells depending on a variety of factors, including cancer stage. Indeed, CAFs have been shown to promote tumour growth, survival and spread, and secretome changes, but they can also slow tumourigenesis at an early stage through mechanisms that are still poorly understood. Stromal-cancer interactions are governed by a variety of soluble factors that determine the outcome of the tumourigenic process. Cancer cells release factors that enhance the ability of fibroblasts to secrete multiple tumour-promoting chemokines, acting on malignant cells to promote proliferation, migration, and invasion. This crosstalk between CAFs and tumour cells has given new prominence to the stromal cells, from being considered as mere physical support to becoming key players in the tumour process. Here, we focus on the concept of cancer as a non-healing wound and the relevance of chronic inflammation to tumour initiation. In addition, we review CAFs heterogeneous origins and markers together with the potential therapeutic implications of CAFs "re-education" and/or targeting tumour progression inhibition.

Role of MicroRNAs in Signaling Pathways Associated with the Pathogenesis of Idiopathic Pulmonary Fibrosis: A Focus on Epithelial-Mesenchymal Transition

Idiopathic pulmonary fibrosis (IPF) is a chronic and progressive disease with high mortality and unclear etiology. Previous evidence supports that the origin of this disease is associated with epigenetic alterations, age, and environmental factors. IPF initiates with chronic epithelial lung injuries, followed by basal membrane destruction, which promotes the activation of myofibroblasts and excessive synthesis of extracellular matrix (ECM) proteins, as well as epithelial-mesenchymal transition (EMT). Due to miRNAs’ role as regulators of apoptosis, proliferation, differentiation, and cell-cell interaction processes, some studies have involved miRNAs in the biogenesis and progression of IPF. In this context, the analysis and discussion of the probable association of miRNAs with the signaling pathways involved in the development of IPF would improve our knowledge of the associated molecular mechanisms, thereby facilitating its evaluation as a therapeutic target for this severe lung disease. In this work, the most recent publications evaluating the role of miRNAs as regulators or activators of signal pathways associated with the pathogenesis of IPF were analyzed. The search in Pubmed was made using the following terms: “miRNAs and idiopathic pulmonary fibrosis (IPF)”; “miRNAs and IPF and signaling pathways (SP)”; and “miRNAs and IPF and SP and IPF pathogenesis”. Additionally, we focus mainly on those works where the signaling pathways involved with EMT, fibroblast differentiation, and synthesis of ECM components were assessed. Finally, the importance and significance of miRNAs as potential therapeutic or diagnostic tools for the treatment of IPF are discussed.

Cancer-associated fibroblasts (CAFs) and tumor-associated macrophages (TAMs); where do they stand in tumorigenesis and how they can change the face of cancer therapy?

The tumor microenvironment (TME) and its components have recently attracted tremendous attention in cancer treatment strategies, as alongside the genetic and epigenetic alterations in tumor cells, TME could also provide a fertile background for malignant cells to survive and proliferate. Interestingly, TME plays a vital role in the mediation of cancer metastasis and drug resistance even against immunotherapeutic agents. Among different cells that are presenting in TME, tumor-associated macrophages (TAMs) and cancer-associated fibroblasts (CAFs) have shown to have significant value in the regulation of angiogenesis, tumor metastasis, and drug-resistance through manipulating the composition as well as the organization of extracellular matrix (ECM). Evidence has shown that the presence of both TAMs and CAFs in TME is associated with poor prognosis and failure of chemotherapeutic agents. It seems that these cells together with ECM form a shield around tumor cells to protect them from the toxic agents and even the adaptive arm of the immune system, which is responsible for tumor surveillance. Given this, targeting TAMs and CAFs seems to be an essential approach to potentiate the cytotoxic effects of anti-cancer agents, either conventional chemotherapeutic drugs or immunotherapies. In the present review, we aimed to take a deep look at the mechanobiology of CAFs and TAMs in tumor progression and to discuss the available therapeutic approaches for harnessing these cells in TME.

microRNAs and Inflammatory Immune Response in SARS-CoV-2 Infection: A Narrative Review

The current SARS-CoV-2 pandemic has emerged as an international challenge with strong medical and socioeconomic impact. The spectrum of clinical manifestations of SARS-CoV-2 is wide, covering asymptomatic or mild cases up to severe and life-threatening complications. Critical courses of SARS-CoV-2 infection are thought to be driven by the so-called “cytokine storm”, derived from an excessive immune response that induces the release of proinflammatory cytokines and chemokines. In recent years, non-coding RNAs (ncRNAs) emerged as potential diagnostic and therapeutic biomarkers in both inflammatory and infectious diseases. Therefore, the identification of SARS-CoV-2 miRNAs and host miRNAs is an important research topic, investigating the host–virus crosstalk in COVID-19 infection, trying to answer the pressing question of whether miRNA-based therapeutics can be employed to tackle SARS-CoV-2 complications. In this review, we aimed to directly address ncRNA role in SARS-CoV-2-immune system crosstalk upon COVID-19 infection, particularly focusing on inflammatory pathways and cytokine storm syndromes.

Circulating miRNAs: Potential diagnostic role for coronavirus disease 2019 (COVID-19)

Nowadays, the coronavirus disease (COVID-19) pandemic, caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) represents a major global health problem. Intensive efforts are being employed to better understand this pathology and develop strategies enabling its early diagnosis and efficient treatment. In this study, we compared the signature of circulating miRNAs in plasma of COVID-19 patients versus healthy donors. MiRCURY LNA miRNA miRNome qPCR Panels were performed for miRNA signature characterization. Individual quantitative real-time PCR (qRT-PCR) was carried out to validate miRNome qPCR results. Receiver-operator characteristic (ROC) curve analysis was applied to assess the diagnostic accuracy of the most significantly deregulated miRNA(s) as potential diagnostic biomarker(s). Eight miRNAs were identified to be differentially expressed with miR-17-5p and miR-142-5p being down-regulated whilst miR-15a-5p, miR-19a-3p, miR-19b-3p, miR-23a-3p, miR-92a-3p and miR-320a being up-regulated in SARS-CoV-2-infected patients. ROC curve analyses revealed an AUC (Areas Under the ROC Curve) of 0.815 (P = 0.031), 0.875 (P = 0.012), and 0.850 (P = 0.025) for miR-19a-3p, miR-19b-3p, and miR-92a-3p, respectively. Combined ROC analyses using these 3 miRNAs showed a greater AUC of 0.917 (P = 0.0001) indicating a robust diagnostic value of these 3 miRNAs. These results suggest that plasma miR-19a-3p, miR-19b-3p, and miR-92a-3p expression levels could serve as potential diagnostic biomarker and/or a putative therapeutic target during SARS-CoV-2-infection.

Obesity-Activated Lung Stromal Cells Promote Myeloid Lineage Cell Accumulation and Breast Cancer Metastasis

Obesity is correlated with increased incidence of breast cancer metastasis; however, the mechanisms underlying how obesity promotes metastasis are unclear. In a diet-induced obese mouse model, obesity enhanced lung metastasis in both the presence and absence of primary mammary tumors and increased recruitment of myeloid lineage cells into the lungs. In the absence of tumors, obese mice demonstrated increased numbers of myeloid lineage cells and elevated collagen fibers within the lung stroma, reminiscent of premetastatic niches formed by primary tumors. Lung stromal cells isolated from obese tumor-naïve mice showed increased proliferation, contractility, and expression of extracellular matrix, inflammatory markers and transforming growth factor beta-1 (TGFβ1). Conditioned media from lung stromal cells from obese mice promoted myeloid lineage cell migration in vitro in response to colony-stimulating factor 2 (CSF2) expression and enhanced invasion of tumor cells. Together, these results suggest that prior to tumor formation, obesity alters the lung microenvironment, creating niches conducive to metastatic growth.

Mechanical stretch and LPS affect the proliferation, extracellular matrix remodeling and viscoelasticity of lung fibroblasts

The present study aimed to investigate the effects of mechanical stretch and lipopolysaccharides (LPS) on the expression of transforming growth factor-β1 (TGF-β1) and collagen and viscoelasticity in human embryonic MRC-5 lung fibroblasts cultured in vitro and to assess the mechanisms of ARDS-associated ventilator-induced lung injury using an in vitro model. Human embryonic MRC-5 lung fibroblasts were treated with different concentrations of LPS to establish an acute respiratory distress syndrome (ARDS) cell injury model, followed by further culture under different mechanical stretch amplitudes using the Flexcell system to establish a cellular mechanical damage model. The proliferation of MRC-5 cells and the protein and gene expression levels of TGF-β1 and collagen were detected by flow cytometry, ELISA and reverse transcription-quantitative PCR, respectively. As the concentration of LPS increased, the proliferation activity of MRC-5 cells gradually decreased. Low concentrations of LPS led to upregulation of the secretion levels of TGF-β1 and collagen I and the expression of their mRNA, TGF-β1 mRNA and collagen type 1, α1. Conversely, high concentrations of LPS reduced TGF-β1 and collagen I levels and their gene expression. Mechanical stimulation with a stretch of 5% increased the cell proliferation activity; however, it had no significant effect on the expression levels of TGF-β1 and collagen. Mechanical stimulation with a stretching force of 10% inhibited the cell proliferation but increased the expression levels of TGF-β1 and collagen I. A higher mechanical stimulation (15 and 20%) had a significantly greater effect. Mechanical stretch and LPS stimulation led to changes in the structure and viscoelastic behavior of human embryonic MRC-5 lung fibroblasts. In terms of cell function, mechanical stretch may cause an increase in the expression of TGF-β1 in MRC-5 cells, in turn affecting the transcription and translation of collagen genes. This present study provides provides cell-level evidence for understand the mechanisms of action behind the ARDS ventilator-induced lung injury and lung structural remodeling.

lncRNA ZFAS1 promotes lung fibroblast-to-myofibroblast transition and ferroptosis via functioning as a ceRNA through miR-150-5p/SLC38A1 axis

Pulmonary fibrosis (PF) is a lethal fibrotic lung disease. The role of lncRNAs in multiple diseases has been confirmed, but the role and mechanism of lncRNA zinc finger antisense 1 (ZFAS1) in the progression of PF need to be elucidated further. Here, we found that lncRNA ZFAS1 was upregulated in bleomycin (BLM)-induced PF rats lung tissues and transforming growth factor-β1 (TGF-β1)-treated HFL1 cells, and positively correlated with the expression of solute carrier family 38 member 1 (SLC38A1), which is an important regulator of lipid peroxidation. Moreover, knockdown of lncRNA ZFAS1 significantly alleviated TGF-β1-induced fibroblast activation, inflammation and lipid peroxidation. In vivo experiments showed that inhibition of lncRNA ZFAS1 abolished BLM-induced lipid peroxidation and PF development. Mechanistically, silencing of lncRNA ZFAS1 attenuated ferroptosis and PF progression by lncRNA ZFAS1 acting as a competing endogenous RNA (ceRNA) and sponging miR-150-5p to downregulate SLC38A1 expression. Collectively, our studies demonstrated the role of the lncRNA ZFAS1/miR-150-5p/SLC38A1 axis in the progression of PF, and may provide a new biomarker for the treatment of PF patients.

Pulmonary Silicosis Alters MicroRNA Expression in Rat Lung and miR-411-3p Exerts Anti-fibrotic Effects by Inhibiting MRTF-A/SRF Signaling

To identify potential therapeutic targets for pulmonary fibrosis induced by silica, we studied the effects of this disease on the expression of microRNAs (miRNAs) in the lung. Rattus norvegicus pulmonary silicosis models were used in conjunction with high-throughput screening of lung specimens to compare the expression of miRNAs in control and pulmonary silicosis tissues. A total of 70 miRNAs were found to be differentially expressed between control and pulmonary silicosis tissues. This included 41 miRNAs that were upregulated and 29 that were downregulated relative to controls. Among them, miR-292-5p, miR-155-3p, miR-1193-3p, miR-411-3p, miR-370-3p, and miR-409a-5p were found to be similarly altered in rat lung and transforming growth factor (TGF)-β1-induced cultured fibroblasts. Using miRNA mimics and inhibitors, we found that miR-1193-3p, miR-411-3p, and miR-370-3p exhibited potent anti-fibrotic effects, while miR-292-5p demonstrated pro-fibrotic effects in TGF-β1-stimulated lung fibroblasts. Moreover, we also found that miR-411-3p effectively reduced pulmonary silicosis in the mouse lung by regulating Mrtfa expression, as demonstrated using biochemical and histological assays. In conclusion, our findings indicate that miRNA expression is perturbed in pulmonary silicosis and suggest that therapeutic interventions targeting specific miRNAs might be effective in the treatment of this occupational disease.

Exosomal miR-19a from adipose-derived stem cells suppresses differentiation of corneal keratocytes into myofibroblasts

In this study, we investigated the effects of exosomal microRNAs (miRNAs) from adipose-derived stem cells (ADSCs) on the differentiation of rabbit corneal keratocytes. Keratocytes grown in 10% FBS differentiated into myofibroblasts by increasing HIPK2 kinase levels and activity. HIPK2 enhanced p53 and Smad3 pathways in FBS-induced keratocytes. Keratocytes grown in 10% FBS also showed increased levels of pro-fibrotic proteins, including collagen III, MMP9, fibronectin, and α-SMA. These effects were reversed by knocking down HIPK2. Moreover, ADSCs and exosomes derived from ADSCs (ADSCs-Exo) suppressed FBS-induced differentiation of keratocytes into myofibroblasts by inhibiting HIPK2. Quantitative RT-PCR analysis showed that ADSCs-Exos were significantly enriched in miRNA-19a as compared to ADSCs. Targetscan and dual luciferase reporter assays confirmed that the HIPK2 3'UTR is a direct binding target of miR-19a. Keratocytes treated with 10% FBS and ADSCs-Exo-miR-19a-agomir or ADSCs-Exo-NC-antagomir showed significantly lower levels of HIPK2, phospho-Smad3, phospho-p53, collagen III, MMP9, fibronectin and α-SMA than those treated with 10% FBS plus ADSCs-Exo-NC-agomir or ADSCs-Exo-miR-19a-antagomir. Thus, exosomal miR-19a derived from the ADSCs suppresses FBS-induced differentiation of rabbit corneal keratocytes into myofibroblasts by inhibiting HIPK2 expression. This suggests their potential use in the treatment of corneal fibrosis.

Cancer-associated fibroblasts-heroes or villains?

Cancer-associated fibroblasts (CAFs) were originally presumed to represent a homogeneous population uniformly driving tumorigenesis, united by their morphology and peritumoural location. Our understanding of CAFs has since been shaped by sophisticated in vitro and in vivo experiments, pathological association and, more recently, ablation, and it is now widely appreciated that CAFs form a group of highly heterogeneous cells with no single overarching marker. Studies have demonstrated that the CAF population contains different subtypes based on the expression of marker proteins with the capacity to promote or inhibit cancer, with their biological role as accomplices or adversaries dependent on many factors, including the cancer stage. So, while CAFs have been endlessly shown to promote the growth, survival and spread of tumours via improvements in functionality and an altered secretome, they are also capable of retarding tumorigenesis via largely unknown mechanisms. It is important to reconcile these disparate results so that the functions of, or factors produced by, tumour-promoting subtypes can be specifically targeted to improve cancer patient outcomes. This review will dissect out CAF complexity and CAF-directed cancer treatment strategies in order to provide a case for future, rational therapies.

Correlation analysis between mechanical power, transforming growth factor-β1, and connective tissue growth factor levels in acute respiratory distress syndrome patients and their clinical significance in pulmonary structural remodeling

BACKGROUND

To identify the clinical correlations between mechanical power and transforming growth factor-β1 (TGF-β1) and connective tissue growth factor (CTGF) in acute respiratory distress syndrome (ARDS) patients, their clinical significance in pulmonary structural remodeling in ARDS patients was investigated.

METHODS

Ninety-five patients with moderate or severe ARDS, who required mechanical ventilation therapy, were randomly selected among hospitalized patients from January 2017 to February 2019. Their mechanical power was monitored and recorded, the TGF-β1 and CTGF levels were detected by enzyme-linked immunosorbent assay (ELISA), their relevance was analyzed, and the relationship between mechanical power and 28-day survival rate was investigated. According to the high-resolution computed tomography (HRCT) examination, the patients were divided into an ARDS group and an ARDS pulmonary fibrosis (ARDS-PF) group. The differences in mechanical power, TGF-β1, and CTGF between the 2 groups were compared, and the significance of TGF-β1 and CTGF in the diagnosis of ARDS pulmonary interstitial fibrosis were evaluated.

RESULTS

A significant positive correlation between mechanical power and serum TGF-β1 and CTGF in patients with ARDS was found and the correlation coefficients were 0.424 and 0.581, respectively. The difference between mechanical power and 28-day survival rate was statistically significant (P < .05), while the area under the receiver operating characteristic curves of TGF-β1 and CTGF for the diagnosis of ARDS pulmonary fibrosis was 0.838 and 0.884, respectively (P < .05).

CONCLUSION

A significant correlation between mechanical power and serum fibrosis biomarkers TGF-β1 and CTGF in ARDS patients was found, and its level was related to the survival prognosis of patients. Mechanical power, TGF-β1, and CTGF were clinically evaluated for the assessment of lung structural remodeling, such as ARDS pulmonary fibrosis. This study has particular significance to the early prevention of ventilator-induced lung injury and pulmonary fibrosis in patients with ARDS receiving mechanical ventilation.