SHIP-1, a target of miR-155, regulates endothelial cell responses in lung fibrosis

miR-92a-3p promotes pulmonary fibrosis progression by regulating KLF2-mediated endothelial-to-mesenchymal transition

Pulmonary fibrosis (PF) is a chronic lung disease that has a poor prognosis and a serious impact on the quality of life of patients. Here, we investigated the potential role of miR-92a-3p in PF. The mRNA level of miR-92a-3p was significantly increased in both the lung tissues of bleomycin (BLM)--treated mice and pulmonary microvascular endothelial cells (PMVECs). Overexpressing miR-92a-3p increased the mRNA and protein levels of α‑SMA, vimentin, and Col-1 but downregulated E-cadherin. Additionally, the protein and mRNA expression levels of KLF2 were significantly decreased in the lung tissues of BLM-treated mice, suggesting that KLF2 participated in the progression of BLM-induced PF. Downregulating miR-92a-3p upregulated the expression of KLF2 and inhibited the endothelial-to-mesenchymal transition (EndoMT) process, thus alleviating PF in vivo. Altogether, a miR-92a-3p deficiency could significantly reduce the development of myofibroblasts and ameliorate PF progression.

ORF3a of SARS-CoV-2 modulates PI3K/AKT signaling in human lung epithelial cells via hsa-miR-155-5p

SARS-CoV-2 infection results in cytokine burst, leading to proinflammatory responses in lungs of COVID-19 patients. SARS-CoV-2 ORF3a triggers the generation of proinflammatory cytokines. However, the underlying mechanism of dysregulation of proinflammatory responses is not well understood. We studied the role of microRNA in the generation of proinflammatory responses as a bystander effect of SARS-CoV-2 ORF3a in human lung epithelial cells. We observed upregulation of hsa-miR-155-5p in SARS-CoV-2 ORF3a transfected human lung epithelial cells, which led to the reduced expression of SHIP1. This resulted in phosphorylation of AKT and NF-κB, which further led to the increased expression of the proinflammatory cytokines IL-6 and TNF-α. Additionally, overexpression and knockdown studies of hsa-miR-155-5p were performed to confirm the role of hsa-miR-155-5p in the regulation of the SHIP1. We demonstrated that hsa-miR-155-5p modulates the proinflammatory response by activating the PI3K/AKT pathway through the inhibition of SHIP1 in SARS-CoV-2 ORF3a transfected human lung epithelial cells.

Analysis of Key Genes and miRNA-mRNA Networks Associated with Glucocorticoids Treatment in Chronic Obstructive Pulmonary Disease

Background

Some patients with chronic obstructive pulmonary disease (COPD) benefit from glucocorticoid (GC) treatment, but its mechanism is unclear.

Objective

With the help of the Gene Expression Omnibus (GEO) database, the key genes and miRNA-mRNA related to the treatment of COPD by GCs were discussed, and the potential mechanism was explained.

Methods

The miRNA microarray dataset (GSE76774) and mRNA microarray dataset (GSE36221) were downloaded, and differential expression analysis were performed. Gene Ontology (GO) function and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway enrichment analyses were performed on the differentially expressed genes (DEGs). The protein interaction network of the DEGs in the regulatory network was constructed with the STRING database, and the key genes were screened through Cytoscape. Potential downstream target genes regulated by differentially expressed miRNAs (DEMs) were predicted by the miRWalk3.0 database, and miRNA-mRNA regulatory networks were constructed. Finally, some research results were validated.

Results

① Four DEMs and 83 DEGs were screened; ② GO and KEGG enrichment analysis mainly focused on the PI3K/Akt signalling pathway, ECM receptor interaction, etc.; ③ CD2, SLAMF7, etc. may be the key targets of GC in the treatment of COPD; ④ 18 intersection genes were predicted by the mirwalk 3.0 database, and 9 pairs of miRNA-mRNA regulatory networks were identified; ⑤ The expression of miR-320d-2 and TFCP2L1 were upregulated by dexamethasone in the COPD cell model, while the expression of miR-181a-2-3p and SLAMF7 were downregulated.

Conclusion

In COPD, GC may mediate the expression of the PI3K/Akt signalling pathway through miR-181a-2-3p, miR-320d-2, miR-650, and miR-155-5p, targeting its downstream signal factors. The research results provide new ideas for RNA therapy strategies of COPD, and also lay a foundation for further research.

SHIP1 and its role for innate immune regulation-Novel targets for immunotherapy

Phosphoinositide-3-kinase/AKT (PI3K/AKT) signaling plays key roles in the regulation of cellular activity in both health and disease. In immune cells, this PI3K/AKT pathway is critically regulated by the phosphoinositide phosphatase SHIP1, which has been reported to modulate the function of most immune subsets. In this review, we summarize our current knowledge of SHIP1 with a focus on innate immune cells, where we reflect on the most pertinent aspects described in the current literature. We also present several small-molecule agonists and antagonists of SHIP1 developed over the last two decades, which have led to improved outcomes in several preclinical models of disease. We outline these promising findings and put them in relation to human diseases with unmet medical needs, where we discuss the most attractive targets for immune therapies based on SHIP1 modulation.

Regulation of Microglial Signaling by Lyn and SHIP-1 in the Steady-State Adult Mouse Brain

Chronic neuroinflammation and glial activation are associated with the development of many neurodegenerative diseases and neuropsychological disorders. Recent evidence suggests that the protein tyrosine kinase Lyn and the lipid phosphatase SH2 domain-containing inositol 5' phosphatase-1 (SHIP-1) regulate neuroimmunological responses, but their homeostatic roles remain unclear. The current study investigated the roles of Lyn and SHIP-1 in microglial responses in the steady-state adult mouse brain. Young adult Lyn-/- and SHIP-1-/- mice underwent a series of neurobehavior tests and postmortem brain analyses. The microglial phenotype and activation state were examined by immunofluorescence and flow cytometry, and neuroimmune responses were assessed using gene expression analysis. Lyn-/- mice had an unaltered behavioral phenotype, neuroimmune response, and microglial phenotype, while SHIP-1-/- mice demonstrated reduced explorative activity and exhibited microglia with elevated activation markers but reduced granularity. In addition, expression of several neuroinflammatory genes was increased in SHIP-1-/- mice. In response to LPS stimulation ex vivo, the microglia from both Lyn-/- and SHIP-1-/- showed evidence of hyper-activity with augmented TNF-α production. Together, these findings demonstrate that both Lyn and SHIP-1 have the propensity to control microglial responses, but only SHIP-1 regulates neuroinflammation and microglial activation in the steady-state adult brain, while Lyn activity appears dispensable for maintaining brain homeostasis.

[Arecoline induces activation of human oral fibroblasts by promoting macrophage secretion of exosomes containing miR-155-5p]

OBJECTIVE

To investigate the mechanism by which arecoline regulates the level of miR-155-5p in macrophage-secreted exosomes to induce the transformation of human oral mucosal fibroblasts (HOMFs) into fibroblast phenotype.

METHODS

Exosomes were harvested from human monocytic cell line THP-1 with or without arecoline treatment. The effects of arecoline-treated THP-1 cell culture supernatant (CS), THP-1-derived exosomes (EXO), exosome-depleted THP-1 cell supernatant (NES), miR-155-5p overexpression, and miR-155-5p inhibitor on migration ability of arecoline-treated HOMF cells were examined using Transwell migration assay. The polarization of THP-1 cells was detected using flow cytometry. DCFH-DA was used to detect the level of oxidative stress in the cells with different treatments. The mRNA and protein expressions of α- SMA, type I collagen and SOCS1 in the cells were detected with qRT-PCR and Western blotting.

RESULTS

Flow cytometry showed that arecoline-treated THP-1 cells exhibited obvious polarization from M₀ to M₁. Both the supernatant and exosomes from arecoline-treated THP-1 cells significantly enhanced the migration ability of HOMF cells, increased intracellular oxidative stress, up-regulated the expressions of miR-155- 5p and the mRNA and protein levels of α-SMA and type I collagen, and lowered the mRNA and protein expressions of SOCS1. In HOMF cells treated with exosomes from arecoline- treated THP-1 cells, overexpression of miR-155-5p significantly enhanced cell migration ability and increased cellular expressions of α-SMA and type I collagen, and miR-155-5p inhibitor caused the opposite changes.

CONCLUSION

Arecoline can up-regulate miR-155-5p expression in THP-1 cells and inhibit the expression of SOCS1 protein in HOMF cells via the exosome pathway, thus promoting the fibrotic phenotype transformation of HOMF cells.

MiR-155-5p-SOCS1/JAK1/STAT1 participates in hepatic lymphangiogenesis in liver fibrosis and cirrhosis by regulating M1 macrophage polarization

BACKGROUND

The role and underlying mechanism of liver macrophages and their derived miR-155-5p in hepatic lymphangiogenesis in liver fibrosis remain unclear. Here, we investigated the mechanism by which macrophages and miR-155-5p were involved in lymphangiogenesis during liver fibrosis and cirrhosis.

METHODS

In vivo, hepatic lymphatic vessel expansion was evaluated; the liver macrophage subsets, proportion of peripherally-derived macrophages and expressions of CCL25, MCP-1, VAP-1 and MAdCAM-1 were documented; and miR-155-5p in the peripheral blood and liver was detected. In vitro, macrophages with miR-155-5p overexpression and inhibition were used to clarify the effect of miR-155-5p on regulation of macrophage polarization and the possible signalling pathway.

RESULTS

Hepatic lymphangiogenesis was observed in mice with liver fibrosis and cirrhosis challenged with carbon tetrachloride (CCl4). In the liver, the number of M1 macrophages was associated with lymphangiogenesis and the degree of fibrosis. The liver recruitment of peripherally-derived macrophages occurred during liver fibrosis. The levels of miR-155-5p in the liver and peripheral blood gradually increased with aggravation of liver fibrosis. In vitro, SOCS1, a target of miR-155-5p, regulated macrophage polarization into the M1 phenotype through the JAK1/STAT1 pathway.

CONCLUSION

MiR-155-5p-SOCS1/JAK1/STAT1 pathway participates in hepatic lymphangiogenesis in mice with liver fibrosis and cirrhosis induced by CCl4 by regulating the polarization of macrophages into the M1 phenotype.

Non-coding RNA in idiopathic interstitial pneumonia and Covid-19 pulmonary fibrosis

Pulmonary fibrosis is the key feature of majority of idiopathic interstitial pneumonias (IIPs) as well as many patients with post-COVID-19. The pathogenesis of pulmonary fibrosis is a complex molecular process that involves myriad of cells, proteins, genes, and regulatory elements. The non-coding RNA mainly miRNA, circRNA, and lncRNA are among the key regulators of many protein coding genes and pathways that are involved in pulmonary fibrosis. Identification and molecular mechanisms, by which these non-coding RNA molecules work, are crucial to understand the molecular basis of the disease. Additionally, elucidation of molecular mechanism could also help in deciphering a potential diagnostic/prognostic marker as well as therapeutic targets for IIPs and post-COVID-19 pulmonary fibrosis. In this review, we have provided the latest findings and discussed the role of these regulatory elements in the pathogenesis of pulmonary fibrosis associated with Idiopathic Interstitial Pneumonia and Covid-19.

mmu-microRNA-92a-3p attenuates pulmonary fibrosis by modulating Cpeb4-mediated Smad2/3 signaling pathway

Pulmonary fibrosis (PF) is a chronic lung disorder, in which the mechanism of mmu-microRNA (miR)-92a-3p is not elucidated clearly. The present work was proposed to disclose mmu-miR-92a-3p-focused mechanism in PF with cytoplasmic polyadenylation element-binding protein 4 (Cpeb4)/Smad2/3 axis. PF was induced in mice by the intratracheal injection of bleomycin (BLM). Then, the BLM-treated mice were injected with mmu-miR-92a-3p- and/or Cpeb4-related adenovirus vectors. mmu-miR-92a-3p, Cpeb4, and Smad2/3 expression in lung tissues were examined. Alveolar cell apoptosis and collagen deposition in lung tissues and inflammatory factors in serum were observed. The interaction between mmu-miR-92a-3p and Cpeb4 was explored. Lowly expressed mmu-miR-92a-3p and highly expressed Cpeb4 and Smad2/3 were manifested in BLM-induced PF mice. BLM-induced PF mice exhibited enhanced inflammation, alveolar cell apoptosis, and collagen deposition, which would be attenuated by upregulating mmu-miR-92a-3p or downregulating Cpeb4. mmu-miR-92a-3p targeted Cpeb4. Upregulating mmu-miR-92a-3p or downregulating Cpeb4 inactivated the Smad2/3 signaling pathway in BLM-induced PF mice. It is elaborated that mmu-miR-92a-3p attenuates the process of PF by modulating Cpeb4-mediated Smad2/3 signaling pathway, renewing the molecular mechanism of PF.

MicroRNA-155 expression is associated with pulpitis progression by targeting SHIP1

BACKGROUND

Pulpitis is a commonly seen oral inflammation condition in clinical practice, it can cause much pain for the patient and may induce infections in other systems. Much is still unknown for the pathogenic mechanism of pulpitis. In this work, we discovered that the expression of miR-155 was associated with dental pulpal inflammation both in vivo and in vitro.

METHODS AND RESULTS

Our experiments of LPS stimulated odontoblast cell line MDPC-23 showed miR-155 could act as a positive regulator by increasing the production of pro-inflammatory cytokines IL-1β and IL-6 during inflammatory responses, whereas knockdown of miR-155 can reverse the effects. Bioinformatics analysis demonstrated that SHIP1 is a direct target of miR-155 in odontoblasts, this result was further verified at both mRNA and protein level. Inhibition of miR-155 resulted in the downregulation of inflammation factors, while co-transfection of si-SHIP1 and miR-155 inhibitor promoted the inflammatory responses. Treatment with miR-155 mimic or si-SHIP1 up-regulated the protein level of p-PI3K and p-AKT. By contrast, miR-155 inhibitor exerted the opposite effects. miR-155 mimics could upregulate the gene expression of IL-1β and IL-6. Co-transfection of LY294002 and miR-155 mimic attenuated the inflammatory responses. Consistent with in vitro results, miR-155^-/- mice could alleviate inflammatory response, as well as decrease the activation of p-PI3K and p-AKT, whereas increase the activation of SHIP1.

CONCLUSIONS

Our data revealed a novel role for miR-155 in regulation of dental pulpal inflammatory response by targeting SHIP1 through PI3K/AKT signaling pathway.

Construction of MicroRNA-mRNA Regulatory Network in the Molecular Mechanisms of Bleomycin-Induced Pulmonary Fibrosis

Bleomycin is a common antitumor agent used to treat many different types of malignancies; however, its main side effect is pulmonary fibrosis. The mechanism of bleomycin-induced pulmonary fibrosis (BIPF) has not been fully elucidated. Therefore, to further explore the molecular mechanisms of BIPF, we screened for microRNA (miRNA) and mRNA expression obtained from BIPF samples from the Gene Expression Omnibus database. Subsequently, we identified the differentially expressed miRNAs and genes that overlapped with the differentially expressed miRNAs target genes, predicted by using the miRWalk database selected as a candidate. The candidate genes were visualized based on Gene Ontology and the Kyoto Encyclopedia of Genes and Genomes analyses. A protein-protein interaction network was constructed. Hub differentially expressed genes were selected and corresponding miRNAs to construct a miRNA-mRNA regulation network. Then, we chose three key miRNAs to study their regulatory relationship in bleomycin-induced pulmonary fibrosis. Finally, mouse lung epithelial cells TC-1 and MLE-12 were treated with bleomycin with qPCR to validate the results of three important hub genes and all key miRNAs. And dual-luciferase report experiment was carried out to verify the interaction of mmu-miR-1946a and serpina3n. The results revealed that the imbalance of matrix metalloproteinase-9 (MMP-9) and tissue inhibitor of metalloproteinase-1 (TIMP-1) plays a pivotal role in the occurrence and development of BIPF. In addition, Serpina3n and mmu-miR-1946a were proved interaction and may be involved in the regulation of the balance between MMP-9 and TIMP-1. The experimental results also verify the analysis. Our findings provide new insights into the key mediators and pathways related to the molecular mechanisms of BIPF.

Linagliptin ameliorates pulmonary fibrosis in systemic sclerosis mouse model via inhibition of endothelial-to-mesenchymal transition

Systemic sclerosis (SSc) is a connective tissue disease that often causes pulmonary fibrosis. Dipeptidyl peptidase 4 (DPP4) inhibitor has shown anti-fibrotic properties in various fibrotic diseases. However, only two studies have reported its anti-fibrosis effects in pulmonary fibrosis, and the mechanism is not completely clear. In the present study, we further investigated the protective effects of linagliptin, a highly specific DPP4 inhibitor, on pulmonary fibrosis in SSc mouse model and the potential mechanisms. The results showed that linagliptin ameliorated pulmonary fibrosis in SSc mouse model, as evidenced by improved pathological changes of lung and body weight loss induced by BLM. Linagliptin also reduced BLM-induced oxidative stress, inflammation in lung in vivo. We revealed that linagliptin attenuated BLM-induced endothelial-to-mesenchymal transition (EndMT) in vitro and in vivo. BLM-induced enhanced migration ability of endothelial cells was also alleviated by linagliptin. Moreover, we confirmed that the Akt/mammalian target of rapamycin pathway was involved in BLM-induced EndMT in vivo, which was suppressed by linagliptin. In summary, we further confirmed the therapeutic effects of linagliptin on pulmonary fibrosis in SSc mouse model, which is based on its inhibitory effects on EndMT, oxidative stress, and inflammation.

Isolation of Primary Mouse Pulmonary Microvascular Endothelial Cells and Generation of an Immortalized Cell Line to Obtain Sufficient Extracellular Vesicles

Pulmonary microvascular endothelial cells (PMECs) and the extracellular vesicles (EVs) derived from PMECs participate in maintaining pulmonary homeostasis and mediating the inflammatory response. However, obtaining a high-purity population of PMECs and their EVs from mouse is still notoriously difficult. Herein we provide a method to isolate primary mouse PMECs (pMPMECs) and to transduce SV40 lentivirus into pMPMECs to establish an immortalized cell line (iMPMECs), which provides sufficient quantities of EVs for further studies. pMPMECs and iMPMECs can be identified using morphologic criteria, a phenotypic expression profile (e.g., CD31, CD144, G. simplicifolia lectin binding), and functional properties (e.g., Dil-acetylated low-density protein uptake, Matrigel angiogenesis). Furthermore, pMPMEC-EVs and iMPMEC-EVs can be identified and compared. The characteristics of pMPMEC-EVs and iMPMEC-EVs are ascertained by transmission electron microscopy, nanoparticle tracking analysis, and specific protein markers. iMPMECs produce far more EVs than pMPMECs, while their particle size distribution is similar. Our detailed protocol to isolate and immortalize MPMECs will provide researchers with an in vitro model to investigate the specific roles of EVs in pulmonary physiology and diseases.

Steatosis, inflammasome upregulation, and fibrosis are attenuated in miR-155 deficient mice in a high fat-cholesterol-sugar diet-induced model of NASH

Nonalcoholic fatty liver disease (NAFLD) is the most common cause of chronic liver disease globally. miRNAs (miRs) regulate various cellular events that lead to NAFLD. In this study we tested the hypothesis that miR-155 is an important regulator of steatohepatitis and fibrosis pathways. Wild type (WT) or miR-155 deficient (KO) mice received a high fat-high cholesterol-high sugar-diet (HF-HC-HS) for 34 weeks and liver tissues were analyzed. In patients with nonalcoholic steatohepatitis and in the mouse model of HF-HC-HS diet we found increased miR-155 levels in the liver compared to normal livers. Upon HF-HC-HS diet feeding, miR-155 KO mice displayed less liver injury, decreased steatosis, and attenuation in fibrosis compared to WT mice. ALT, triglyceride levels, and genes involved in fatty acid metabolic pathway were increased in WT mice whereas miR-155 KO mice showed attenuation in these parameters. HF-HC-HS diet-induced significant increase in the expression of NLRP3 inflammasome components in the livers of WT mice compared to chow fed diet. Compared to WT mice, miR-155 KO showed attenuated induction in the NLRP3, ASC, and caspase1 inflammasome expression on HF-HC-HS diet. Fibrosis markers such as collagen content and deposition, αSMA, Zeb2, and vimentin were all increased in WT mice and miR-155 KO mice showed attenuated fibrosis marker expression. Overall, our findings highlight a role for miR-155 in HF-HC-HS diet-induced steatosis and liver fibrosis.

LncRNA GAS5 participates in childhood pneumonia by inhibiting cell apoptosis and promoting SHIP-1 expression via downregulating miR-155

Background

LncRNA GAS5 and miR-155 are reported to play opposite roles in lung inflammatory responses. Lung inflammation participates in childhood pneumonia, indicating the involvement of GAS5 and miR-155 in pneumonia. The study aimed to analyze the potential interaction between GAS5 and miR-155 in childhood pneumonia.

Methods

GAS5 and miR-155 levels in plasma samples from pneumonia patients and controls were detected using RT-qPCR. The role of GAS5 in miR-155 RNA gene methylation in human bronchial epithelial cells (HBEpCs) was analyzed by methylation analysis. Flow cytometry and RT-qPCR were applied to analyze cell apoptosis and SHIP-1 expression, respectively.

Results

GAS5 was downregulated in pneumonia, and miR-155 was upregulated in pneumonia. GAS5 and miR-155 were inversely correlated. GAS5 overexpression decreased miR-155 expression in HBEpCs, while miR-155 overexpression showed no significant effects on GAS5 expression. In addition, GAS5 suppressed LPS-induced HBEpC apoptosis, promoted SHIP-1 expression, and reduced the enhancing effect of miR-155 on cell apoptosis and SHIP-1 expression.

Conclusions

GAS5 may participate in childhood pneumonia by inhibiting cell apoptosis and promoting SHIP-1 expression via downregulating miR-155.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12890-021-01724-y.

Circulating plasma miR-155 is a potential biomarker for the detection of SARS-CoV-2 infection

Identification of human miRNAs involved in coronavirus-host interplay is important due to the current COVID-19 pandemic. Therefore, this study aimed to measure the circulating plasma miR-155 expression level in COVID-19 patients and healthy controls to investigate its roles in the pathogenesis and severity of COVID-19 disease and to assess its usefulness as a clinical biomarker for the detection of COVID-19 disease and the severity of infection.

A total of 150 COVID-19 patients and 50 controls were enrolled into our study. Beside the routine laboratory work and chest computed tomography (CT) scans of COVID-19 patients, plasma miR-155 expression level was measured using reverse transcription quantitative real-time PCR (RT-qPCR) technique.

Our results demonstrated increased miR-155 expression level in COVID-19 patients compared to controls, in severe compared to moderate COVID-19 patients, and in non-survival compared to survival COVID-19 patients. miR-155 expression level also had significant correlation with clinicopathological characteristics of COVID-19 patients such as chest CT findings, CRP, ferritin, mortality, D-dimer, WBC count, and lymphocytes and neutrophils percentages. Also, our results showed that the area under the curve (AUC) for miR-155 was 0.986 with 90% sensitivity and 100% specificity when used as a biomarker for the detection of COVID-19 disease; while in detection of severity of COVID-19 disease, AUC for miR-155 was 0.75 with 76% sensitivity and specificity.

From these results we can conclude that miR-155 has a crucial role in the pathogenesis and severity of COVID-19; also, it could be a good diagnostic clinical biomarker for the detection of COVID-19 disease and the severity of infection.

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.

Bone morphogenetic protein-7 inhibits endothelial-to-mesenchymal transition in primary human umbilical vein endothelial cells and mouse model of systemic sclerosis via Akt/mTOR/p70S6K pathway

BACKGROUND

Systemic sclerosis (SSc) is an autoimmune inflammatory and vascular disorder that causes tissue fibrosis of the skin and internal organs. Endothelial-to-mesenchymal transition (EndoMT) has been considered an important mechanism in the pathogenesis of vascular remodeling in SSc. Recent studies suggested that bone morphogenic protein 7 (BMP-7) has anti-fibrotic effects in several fibrotic diseases.

OBJECTIVES

To investigate the mechanism of BMP-7 in inhibiting TGF-β-induced EndoMT in systemic sclerosis (SSc).

METHODS

Skin tissues of both healthy controls and SSc patients were detected the distribution of BMP-7. TGF-β was applied to induce the EndoMT model of human umbilical vein endothelial cells (HUVECs), and bleomycin was used to established the SSc mouse model. After treatment of BMP-7, the protein levels of endothelial specific markers, mesenchymal cell products, transcription factors and Akt signal pathway were examined by western blotting, immunofluorescence or immunohistochemistry both in vivo and in vitro.

RESULTS

The expression of BMP-7 was decreased in the basal layer of epidermis and dermis of SSc patients. EndoMT in TGF-β-treated HUVECs and skins of SSc mouse model were markedly attenuated after treatment with rh-BMP-7. Moreover, Akt/mTOR/p70S6K phosphorylation was involved in EndoMT and BMP-7 suppressed TGF-β- or bleomycin-induced theses phosphorylation in HUVECs or SSc mouse model.

CONCLUSION

BMP-7 reduced the production of TGF-β-induced EndoMT in HUVECs and SSc mouse model through Akt/mTOR/p70S6K signaling pathway. These findings suggested that BMP-7 could be employed as a promising antifibrotic therapy for SSc.

MicroRNAs as crucial mediators in the pharmacological activities of triptolide (Review)

Triptolide is the main bioactive constituent isolated from the Chinese herb Tripterygium wilfordii Hook F., which possesses a variety of pharmacological properties. MicroRNAs (miRNAs/miRs) are short non-coding RNAs that regulate gene expression post-transcriptionally. miRNAs are implicated in several intracellular processes, whereby their dysregulation contributes to pathogenesis of various diseases. Thus, miRNAs have great potential as biomarkers and therapeutic targets for diseases, and are implicated in drug treatment. Previous studies have reported that specific miRNAs are targeted, and their expression levels can be altered following exposure to triptolide. Thus, miRNAs are emerging as crucial mediators in the pharmacological activities of triptolide. The present review summarizes current literature on miRNAs as target molecules in the pharmacological activities of triptolide, including antitumor, anti-inflammatory, immunosuppressive, renal protective, cardioprotective, antiangiogenesis activities and multiorgan toxicity effects. In addition, the diverse signaling pathways involved are discussed to provide a comprehensive understanding of the underlying molecular mechanisms of triptolide in the regulation of target miRNAs.

Selective deletion of SHIP-1 in hematopoietic cells in mice leads to severe lung inflammation involving ILC2 cells

Src homology 2 domain-containing inositol 5-phosphatase 1 (SHIP-1) regulates the intracellular levels of phosphotidylinositol-3, 4, 5-trisphosphate, a phosphoinositide 3-kinase (PI3K) product. Emerging evidence suggests that the PI3K pathway is involved in allergic inflammation in the lung. Germline or induced whole-body deletion of SHIP-1 in mice led to spontaneous type 2-dominated pulmonary inflammation, demonstrating that SHIP-1 is essential for lung homeostasis. However, the mechanisms by which SHIP-1 regulates lung inflammation and the responsible cell types are still unclear. Deletion of SHIP-1 selectively in B cells, T cells, dendritic cells (DC) or macrophages did not lead to spontaneous allergic inflammation in mice, suggesting that innate immune cells, particularly group 2 innate lymphoid cells (ILC2 cells) may play an important role in this process. We tested this idea using mice with deletion of SHIP-1 in the hematopoietic cell lineage and examined the changes in ILC2 cells. Conditional deletion of SHIP-1 in hematopoietic cells in Tek-Cre/SHIP-1 mice resulted in spontaneous pulmonary inflammation with features of type 2 immune responses and airway remodeling like those seen in mice with global deletion of SHIP-1. Furthermore, when compared to wild-type control mice, Tek-Cre/SHIP-1 mice displayed a significant increase in the number of IL-5/IL-13 producing ILC2 cells in the lung at baseline and after stimulation by allergen Papain. These findings provide some hints that PI3K signaling may play a role in ILC2 cell development at baseline and in response to allergen stimulation. SHIP-1 is required for maintaining lung homeostasis potentially by restraining ILC2 cells and type 2 inflammation.

MiRNA, a New Treatment Strategy for Pulmonary Fibrosis

Pulmonary fibrosis (PF) is the most common chronic, progressive interstitial lung disease, mainly occurring in the elderly, with a median survival of 2-4 years after diagnosis. Its high mortality rate attributes to the delay in diagnosis due to its generic symptoms, and more importantly, to the lack of effective treatments. MicroRNAs (miRNAs) are a class of small non-coding RNAs that are involved in many essential cellular processes, including extracellular matrix remodeling, alveolar epithelial cell apoptosis, epithelial-mesenchymal transition, etc. We summarized the dysregulated miRNAs in TGF-β signaling pathway-mediated PF in recent years with dual effects, such as anti-fibrotic let-7 family and pro-fibrotic miR-21 members. Therefore, this review will set out the latest application of miRNAs to provide a new direction for PF treatment.

Sialic acid-binding immunoglobulin-like lectin 9 as a potential therapeutic target for chronic obstructive pulmonary disease

ABSTRACT

Chronic obstructive pulmonary disease (COPD) has become the third-leading cause of death worldwide, which is a severe economic burden to the healthcare system. Chronic bronchitis is the most common condition that contributes to COPD, both locally and systemically. Neutrophilic inflammation predominates in the COPD airway wall and lumen. Logically, repression of neutrophilia is an essential fashion to COPD treatment. However, currently available anti-neutrophilic therapies provide little benefit in COPD patients and may have serious side effects. Thus, there is an urgent need to explore an effective and safe anti-neutrophilic approach that might delay progression of the disease. Sialic acid-binding immunoglobulin-like lectin (Siglec)-9 is a member of the Siglec cell surface immunoglobulin family. It is noteworthy that Siglec-9 is highly expressed on human neutrophils and monocytes. Ligation of Siglec-9 by chemical compounds or synthetic ligands induced apoptosis and autophagic-like cell death in human neutrophils. Furthermore, administration of antibody to Siglec-E, mouse functional ortholog of Siglec-9, restrained recruitment and activation of neutrophils in mouse models of airway inflammation in vivo. Given the critical role that neutrophils play in chronic bronchitis and emphysema, targeting Siglec-9 could be beneficial for the treatment of COPD, asthma, fibrosis, and related chronic inflammatory lung diseases.

Emerging role of CCN family proteins in fibrosis

Fibrosis is a common pathological change characterized by the excessive accumulation of fibrous connective tissue. Once uncontrolled, this pathological progress can lead to irreversible damage to the structure and function of organs, which is a serious threat to human health and life. Actually, the disability and death of patients caused by many chronic diseases have a closed relationship with fibrosis. The CCN protein family, including six members, is a small group of matrix proteins exhibiting structurally similar features. In the past 20 years, different biological functions of CCN proteins have been identified in various diseases. Of note, it has been recently shown that they are implicated in the key pathological process of fibrosis. In this review, we summarize the current status of knowledge regarding the role of CCN proteins involved in the pathogenesis of fibrosis diseases in detail. Furthermore, we highlight some of the underlying interaction mechanisms of CCN protein acting in fibrosis that helps to develop new drugs and determine appropriate clinical strategies for fibrotic diseases.

The Vascular Involvement in Soft Tissue Fibrosis-Lessons Learned from Pathological Scarring

Soft tissue fibrosis in important organs such as the heart, liver, lung, and kidney is a serious pathological process that is characterized by excessive connective tissue deposition. It is the result of chronic but progressive accumulation of fibroblasts and their production of extracellular matrix components such as collagens. Research on pathological scars, namely, hypertrophic scars and keloids, may provide important clues about the mechanisms that drive soft tissue fibrosis, in particular the vascular involvement. This is because these dermal fibrotic lesions bear all of the fibrotic characteristics seen in soft tissue fibrosis. Moreover, their location on the skin surface means they are readily observable and directly treatable and therefore more accessible to research. We will focus here on the roles that blood vessel-associated cells play in cutaneous scar pathology and assess from the literature whether these cells also contribute to other soft tissue fibroses. These cells include endothelial cells, which not only exhibit aberrant functions but also differentiate into mesenchymal cells in pathological scars. They also include pericytes, hepatic stellate cells, fibrocytes, and myofibroblasts. This article will review with broad strokes the roles that these cells play in the pathophysiology of different soft tissue fibroses. We hope that this brief but wide-ranging overview of the vascular involvement in fibrosis pathophysiology will aid research into the mechanisms underlying fibrosis and that this will eventually lead to the development of interventions that can prevent, reduce, or even reverse fibrosis formation and/or progression.