MiR-138 suppresses airway smooth muscle cell proliferation through the PI3K/AKT signaling pathway by targeting PDK1

Roles of estrogen and its receptors in polycystic ovary syndrome

Polycystic ovary syndrome (PCOS) is an endocrine disorder characterized by abnormal steroid hormone levels in peripheral blood and poor-quality oocytes. In the ovary, androgen is produced by theca cells, and estrogen is produced by granulosa cells. Androgen is converted to estrogen in granulosa cells, with cytochrome P450 aromatase as the limiting enzyme during this process. Estrogen receptors (ER) include ER alpha, ER beta, and membrane receptor GPR30. Studies have demonstrated that the abnormal functions of estrogen and its receptors and estradiol synthesis-related enzymes are closely related to PCOS. In recent years, some estrogen-related drugs have made significant progress in clinical application for subfertility with PCOS, such as letrozole and clomiphene. This article will elaborate on the recent advances in PCOS caused by abnormal expression of estrogen and its receptors and the application of related targeted small molecule drugs in clinical research and treatment.

Noncoding RNAs in asthmatic airway smooth muscle cells

Asthma is a complex and heterogeneous airway disease caused by genetic, environmental and epigenetic factors treated with hormones and biologics. Irreversible pathological changes to airway smooth muscle cells (ASMCs) such as hyperplasia and hypertrophy can occur in asthmatic patients. Determining the mechanisms responsible is vital for preventing such changes. In recent years, noncoding RNAs (ncRNAs), especially microRNAs, long noncoding RNAs and circular RNAs, have been found to be associated with abnormalities of the ASMCs. This review highlights recent ncRNA research into ASMC pathologies. We present a schematic that illustrates the role of ncRNAs in pathophysiological changes to ASMCs that may be useful in future research in diagnostic and treatment strategies for patients with asthma.

Cystatin SN in type 2 inflammatory airway diseases

Cystatin SN, encoded by CST1, belongs to the type 2 (T2) cystatin protein superfamily. In the past decade, several publications have highlighted the association between cystatin SN and inflammatory airway diseases including chronic rhinosinusitis, rhinitis, asthma, chronic obstructive pulmonary disease, and chronic hypersensitivity pneumonitis. It is, therefore, crucial to understand the role of cystatin SN in the wider context of T2 inflammatory diseases. Here, we review the expression of cystatin SN in airway-related diseases with different endotypes. We also emphasize the physiological and pathological roles of cystatin SN. Physiologically, cystatin SN protects host tissues from destructive proteolysis by cysteine proteases present in the external environment or produced via internal dysregulated expression. Pathologically, the secretion of cystatin SN from airway epithelial cells initiates and amplifies T2 immunity and subsequently leads to disease. We further discuss the development of cystatin SN as a T2 immunity marker that can be monitored noninvasively and assist in airway disease management. The discovery, biology, and inhibition capability are also introduced to better understand the role of cystatin SN in airway diseases.

Aberrant expression of miR-138 as a novel diagnostic biomarker in systemic sclerosis

BACKGROUND

MicroRNAs are short nucleotide sequences that contribute to the regulation of various biological functions and therefore their roles have been investigated in many pathologic conditions such as epithelial to mesenchymal transition in cancer and fibrosis; among them, miR-138 has been mostly studied in cancer biology and is well-known for its suppressing effect on cancer progression. Being able to suppress major pathways involved in EMT, miR-138 could be a good candidate to be investigated in fibrotic responses too. Based on our previous studies, and the capability of miR-138 to target and regulate several components of the EMT pathway; we hypothesized a role for miR-138 in systemic sclerosis. Accordingly, the gene expression of miR-138 was assessed to find any alterations in the whole blood of the SSc patients.

METHODS

Blood was collected from 70 patients with systemic sclerosis (equally divided between 2 groups of limited and diffuse categories) and 30 healthy individuals as controls. RNA was immediately isolated from the fresh whole blood; afterward, the resulting RNA was reverse transcribed into cDNA and then the relative expression of miR-138 was compared between the patients and the controls by the means of qPCR, and specific TaqMan primer and probes.

RESULTS

The relative expression of miR-138 was significantly lower in patients with systemic sclerosis compared to the controls. No significant difference was observed between the limited and diffuse patient groups. ROC curve analysis showed an appropriate diagnostic value of miR-138 in effectively differentiating SSc patients from the healthy controls.

CONCLUSION

miR-138 is likely involved in the pathogenesis of SSc and with further evaluations may be utilized as a diagnostic biomarker in SSc. Also, targeting miR-138 in future studies could be promising for finding a novel treatment option for patients with SSc.

High-content analysis of microRNAs involved in the phenotype regulation of vascular smooth muscle cells

In response to vascular injury vascular smooth muscle cells (VSMCs) alternate between a differentiated (contractile) and a dedifferentiated (synthetic) state or phenotype. Although parts of the signaling cascade regulating the phenotypic switch have been described, the role of miRNAs is still incompletely understood. To systematically address this issue, we have established a microscopy-based quantitative assay and identified 23 miRNAs that induced contractile phenotypes when over-expressed. These were then correlated to miRNAs identified from RNA-sequencing when comparing cells in the contractile and synthetic states. Using both approaches, six miRNAs (miR-132-3p, miR-138-5p, miR-141-3p, miR-145-5p, miR-150-5p, and miR-22-3p) were filtered as candidates that induce the phenotypic switch from synthetic to contractile. To identify potentially common regulatory mechanisms of these six miRNAs, their predicted targets were compared with five miRNAs sharing ZBTB20, ZNF704, and EIF4EBP2 as common potential targets and four miRNAs sharing 16 common potential targets. The interaction network consisting of these 19 targets and additional 18 hub targets were created to facilitate validation of miRNA-mRNA interactions by suggesting the most plausible pairs. Furthermore, the information on drug candidates was integrated into the network to predict novel combinatorial therapies that encompass the complexity of miRNAs-mediated regulation. This is the first study that combines a phenotypic screening approach with RNA sequencing and bioinformatics to systematically identify miRNA-mediated pathways and to detect potential drug candidates to positively influence the phenotypic switch of VSMCs.

Long non-coding RNA TUG1 promotes proliferation and migration in PDGF-BB-stimulated HASMCs by regulating miR-216a-3p/SMURF2 axis

BACKGROUND

Abnormal proliferation and migration of human airway smooth muscle cells (HASMCs) play an important role in the development of childhood asthma. Long non-coding RNAs (lncRNAs) have been demonstrated to participate in HASMC proliferation and migration. We aimed to explore more effects and molecular mechanism of taurine upregulated gene 1 (TUG1) in childhood asthma.

RESULTS

TUG1 and SMURF2 were overexpressed and miR-216a-3p was downregulated in childhood asthma patients and PDGF-BB-stimulated HASMCs. TUG1 knockdown attenuated PDGF-BB-triggered proliferation and migration of HASMCs. MiR-216a-3p was targeted by TUG1, and miR-216a-3p suppression counteracted the repressive effects of TUG1 interference on proliferation and migration in PDGF-BB-treated HASMCs. SMURF2 was a downstream target of miR-216a-3p, and SMURF2 upregulation abated the inhibiting effects of miR-216a-3p on migration and proliferation in PDGF-BB-exposed HASMCs. TUG1 sponged miR-216a-3p to positively regulate SMURF2 expression.

CONCLUSION

TUG1 downregulation inhibited PDGF-BB-induced HASMC proliferation and migration by regulating miR-216a-3p/SMURF2 axis, offering novel insight into the potential application of TUG1 for childhood asthma treatment.

Long non-coding RNA TUG1 accelerates abnormal growth of airway smooth muscle cells in asthma by targeting the miR-138-5p/E2F3 axis

Asthma is a chronic airway inflammatory disease. The present study aimed to explore the effect of the long non-coding RNA taurine-upregulated gene 1 (TUG1) on the viability and migration of airway smooth muscle cells (ASMCs) in asthma. Rat asthma models were constructed with ovalbumin sensitization and challenge and the level of serum immunoglobulin E (IgE) and the rates of inspiratory and expiratory resistance were measured. Reverse transcription-quantitative PCR was also performed to determine the expression levels of TUG1. Platelet-derived growth factor-BB (PDGF-BB)-treated ASMCs were then used as a cell model of asthma. The viability and migratory abilities of ASMCs were analysed with the MTT and Transwell assays. Additionally, a dual-luciferase reporter assay was used to confirm the relationship between TUG1 and microRNA (miR)-138-5p and between transcription factor E2F3 and miR-138-5p. The expression of TUG1, level of serum IgE, inspiratory resistance and expiratory resistance were clearly increased in the rat asthma model in comparison with controls. Knockdown of TUG1 the viability and migration of PDGF-BB-induced ASMCs and reduced the inspiratory and expiratory resistances. In addition, TUG1 functioned as a bait of miR-138-5p, and miR-138-5p modulated E2F3 expression. Knockdown of E2F3 hindered the abnormal growth of ASMCs. Moreover, miR-138-5p inhibition or E2F3 overexpression reversed the inhibitory effects of TUG1 knockdown on viability and migration of PDGF-BB-induced ASMCs. The TUG1/miR-138-5p/E2F3 regulatory axis appeared to play a critical role in accelerating the viability and migration of ASMCs and may therefore have a role in asthma.

The circular RNA circCPE regulates myoblast development by sponging miR-138

Background

Skeletal muscle development, a long-term and complex process, is controlled by a set of the myogenic genes. Circular RNAs (circRNAs), a class of noncoding RNA, have been shown to regulate various biological processes. Recent studies indicate circRNAs may be involved in myogenesis, but the role and regulatory mechanism of circRNAs in myogenesis is largely unknown. In the present study, circCPE was firstly found to promote the bovine myoblast proliferation and inhibit cell apoptosis and differentiation by influencing the expression of FOXC1 in a miR138-mediated manner. And in vivo experiments revealed that overexpression of circCPE attenuates skeletal muscle regeneration.

Results

We identified a novel circular RNA circCPE by analyzing circRNAs sequencing data of bovine muscle tissue. Sequencing verification, RNase R treatment and Actinomycin D treatment confirmed the circular nature of circCPE in bovine muscle. Functional assays showed that overexpression of circCPE could inhibit bovine myoblast apoptosis and differentiation, as well as facilitate cell proliferation. Moreover, in vivo experiments revealed that overexpression of circCPE attenuates skeletal muscle regeneration. In consideration of circRNA action as miRNAs sponge, we found that circCPE harbors miR-138 binding sites and absorbed miR-138. Mechanistically, the rescue experiments showed that the overexpression of circCPE can counteract the inhibitory effect of miR-138 on the cell proliferation and the accelerated effects on the differentiation and apoptosis. Subsequently, we found that circCPE sequester the inhibitory effect of miR-138 on FOXC1 so as to involve in myogenesis.

Conclusions

Collectively, we constructed a novel circCPE/miR-138/FOXC1 regulatory network in bovine myogenesis, which further provide stronger evidence that circRNA involved in muscle development acting as miRNA sponge.

Supplementary Information

The online version contains supplementary material available at 10.1186/s40104-021-00618-7.

Airway Epithelial Cells Drive Airway Smooth Muscle Cell Phenotype Switching to the Proliferative and Pro-inflammatory Phenotype

The increased mass of airway smooth muscle (ASM) in the airways of asthmatic patients may contribute to the pathology of this disease by increasing the capacity for airway narrowing. Evidence for the airway epithelium as a participant in ASM remodeling is accruing. To investigate mechanisms by which airway epithelial cells induce ASM cell (ASMC) proliferation, we have employed a co-culture model to explore markers of ASMC proliferative phenotype. Co-culture with epithelial cells led to incorporation of bromodeoxyuridine into ASMCs, indicating augmented proliferation and an associated increase in mRNA of the pro-proliferative co-transcription factor Elk1. Although the mitogen heparin-binding epidermal growth factor (HB-EGF) was augmented in the co-culture supernatant, the ASMC epidermal growth factor receptor (EGFR), an effector of HB-EGF induced proliferation, did not mediate epithelial-induced proliferation. The co-culture increased the expression of ASMC mRNA for the pro-inflammatory cytokines IL-6 and IL-8 as well as the pro-proliferative microRNA miR-210. The transcriptional repressor Max-binding protein (Mnt), a putative target of miR-210, was transcriptionally repressed in co-cultured ASMCs. Together, these data indicate that the airway epithelium-induced proliferative phenotype of ASMCs is not driven by EGFR signaling, but rather may be dependent on miR210 targeting of tumor suppressor Mnt.

MicroRNAs in chronic airway diseases: Clinical correlation and translational applications

MicroRNAs (miRNAs) are short single-stranded RNAs that have pivotal roles in disease pathophysiology through transcriptional and translational modulation of important genes. It has been implicated in the development of many diseases, such as stroke, cardiovascular conditions, cancers and inflammatory airway diseases. There is recent evidence that miRNAs play important roles in the pathogenesis of asthma and chronic obstructive pulmonary disease (COPD), and could help to distinguish between T2-low (non-eosinophilic, steroid-insensitive) versus T2-high (eosinophilic, steroid-sensitive) disease endotypes. As these are the two most prevalent chronic respiratory diseases globally, with rising disease burden, miRNA research might lead to the development of new diagnostic and therapeutic targets. Research involving miRNAs in airway disease is challenging because: (i) asthma and COPD are heterogeneous inflammatory airway diseases; there are overlapping but distinct inter- and intra-disease differences in the immunological pathophysiology, (ii) there exists more than 2000 known miRNAs and a single miRNA can regulate multiple targets, (iii) differential effects of miRNAs could be present in different cellular subtypes and tissues, and (iv) dysregulated miRNA expression might be a direct consequence of an indirect effect of airway disease onset or progression. As miRNAs are actively secreted in fluids and remain relatively stable, they have the potential for biomarker development and therapeutic targets. In this review, we summarize the preclinical data on potential miRNA biomarkers that mediate different pathophysiological mechanisms in airway disease. We discuss the framework for biomarker development using miRNA and highlight the need for careful patient characterization and endotyping in the screening and validation cohorts, profiling both airway and blood samples to determine the biological fluids of choice in different disease states or severity, and adopting an untargeted approach. Collaboration between the various stakeholders - pharmaceutical companies, laboratory professionals and clinician-scientists is crucial to reduce the difficulties and cost required to bring miRNA research into the translational stage for airway diseases.

MicroRNA-138 inhibits tumor growth and enhances chemosensitivity in human cervical cancer by targeting H2AX

MicroRNA-138 (miR-138) acts as a key regulator in the modulation of carcinogenesis in numerous tumor types. Chemoresistance is common and relevant to the failure of multiple treatment strategies for cervical cancer. However, the biological role of miR-138 in the progression and chemosensitivity of cervical cancer is still unclear. The present study aimed to investigate the expression, function and mechanism of miR-138 in cervical cancer. An miR-138 mimic, inhibitor and negative control were transfected into SiHa and C33A cells. The expression of miR-138 and its target were assessed by reverse transcription-PCR, western blotting and immunohistochemistry. The functional significance of miR-138 in tumor progression and chemosensitivity to cisplatin in vitro was examined by Cell Counting Kit-8, flow cytometry, wound healing and Transwell assays. A tumor xenograft model was used to validate the effects in vivo. These results demonstrated that miR-138 was significantly downregulated in cervical cancer cells. Overexpression of miR-138 suppressed cervical cancer cell proliferation, invasion, increased apoptosis and enhanced chemotherapy sensitivity in vivo and in vitro. Furthermore, bioinformatics analysis and dual luciferase reporter assays demonstrated that H2AX served as a target for miR-138, and the rescue experiment revealed that H2AX was a functional target of miR-138. The protective effects of miR-138 overexpression were dependent on H2AX. This study provides evidence that miR-138/H2AX may be a novel therapeutic target in cervical cancer.

Down-regulation of microRNA-138 improves immunologic function via negatively targeting p53 by regulating liver macrophage in mice with acute liver failure

MicroRNAs (miRNAs) have been frequently identified as key mediators in almost all developmental and pathological processes, including those in the liver. The present study was conducted with aims of investigating the role of microRNA-138 (miR-138) in acute liver failure (ALF) via a mechanism involving p53 and liver macrophage in a mouse model. The ALF mouse model was established using C57BL/6 male mice via tail vein injection of Concanamycin A (Con A) solution. The relationship between miR-138 and p53 was tested. The mononuclear macrophages were infected with mimic and inhibitor of miR-138 in order to identify roles of miR-138 in p53 and levels of inflammatory factors. Reverse transcription quantitative polymerase chain reaction (RT-qPCR), Western blot analysis and ELISA were conducted in order to determine the levels of miR-138, inflammatory factors, and p53 during ALF. The results showed an increase in the levels of miR-138 and inflammatory factors in ALF mice induced by the ConA as time progressed and reached the peak at 12 h following treatment with ConA, while it was on the contrary when it came to the level of p53. Dual-luciferase reporter gene assay revealed that p53 was a target gene of miR-138. Furthermore, the results from the in vitro transfection experiments in primary macrophages of ALF mouse showed that miR-138 down-regulated p53 and enhanced levels of inflammatory factors; thus, improving immune function in ALF mice. In conclusion, by negatively targeting p53, the decreased miR-138 improves immunologic function by regulating liver macrophage in mouse models of ALF.

Silencing PDK1 limits hypoxia-induced pulmonary arterial hypertension in mice via the Akt/p70S6K signaling pathway

The present study aimed to investigate the effect of phosphoinositide-dependent protein kinase-1 (PDK1) on hypoxia-induced pulmonary arterial hypertension (PAH). A mouse model of hypoxia-induced PAH was generated using normal or PDK1-knockout mice. Histological analysis and hemodynamic evaluations were performed to identify the progression of PAH. The expression and phosphorylation of PDK1/protein kinase B (Akt) signaling pathway associated proteins were detected by western blot analysis. Increased lung vessel thickness, right ventricular (RV) systolic pressure (RVSP), RV hypertrophy index (RVHI) values [the RV weight-to-left ventricular (LV) plus septum (S) weight ratio] and PDK1 expression were observed in the hypoxia-induced PAH model compared with the normal control. The phosphorylation of Akt^T308, proline-rich Akt1 substrate 1 (PRAS40) and S6KT²²⁹ was also notably increased in the PAH model compared with the control. The changes of proteins were not observed in the hypoxia treated PDK1^flox/+ : Tie2-Cre mice. Similarly, the RVSP and RVHI values, and PDK1 expression were reduced in the hypoxia treated PDK1^flox/+: Tie2-Cre mice to a level comparable with those in the control, suggesting that PDK1 partial knockout significantly limited hypoxia-induced PAH. The results of the present study indicate that PDK1 is essential for hypoxia-induced PAH through the PDK1/Akt/S6K signaling cascades.

Involvement of microRNAs in physiological and pathological processes in asthma

Asthma is the most common respiratory disease accompanied by lung inflammatory disorders. The main symptoms are airway obstruction, chronic inflammation due to mast cell and eosinophil activity, and the disturbance of immune responses mostly mediated by the Th2 response. Genetic background and environmental factors also contribute to the pathogenesis of asthma. Today, microRNAs (miRNAs) are known as remarkable regulators of gene expression. As a small group of noncoding single-strand RNAs, mature miRNAs (~21 nucleotides) modulate the gene expression by targeting complement RNAs at both transcriptional and posttranscriptional levels. The role of miRNAs in the pathogenesis of many diseases such as allergies, asthma, and autoimmunity has been vastly studied. This review provides a thorough research update on the role of miRNAs in the pathogenesis of asthma and their probable role as diagnostic and/or therapeutic biomarkers.

Overexpression of miR-138-5p suppresses MnCl2 -induced autophagy by targeting SIRT1 in SH-SY5Y cells

The mechanism of manganism caused by manganese (Mn), an important environmental risk factor for Parkinson's disease, is still unclear. Recent evidence suggested that autophagy participated in neurodegenerative diseases, in which microRNA played a crucial role. However, roles of microRNA in the aberrant autophagy that occurs in neurodegenerative diseases remains controversial. In nervous system, miRNA-138-5p is highly expressed and plays a key role in regulating memory and axon regeneration. Importantly, we also found that miR-138-5p expression decreased significantly after SH-SY5Y cells exposed to manganese chloride (MnCl₂ ) in previous study. To explore the role of miR-138-5p in Mn-induced autophagy, autophagy associated indicators were detected. And we found that MnCl₂ could induce autophagic dysregulation and inhibit expression of miR-138-5p. While the levels of LC3-II/LC3-I, Beclin1, and p62, the number of autophagosome formation significantly decreased after miR-138-5p over-expression, which demonstrated that miR-138-5p could clearly retard Mn-induced autophagy. In additional, we found there were classical and evolutionarily conserved miR-138-5p binding sites in 3'-UTR region of SIRT1, which was inhibited when overexpression of miR-138-5p. Therefore, it was speculated that elevated expression of SIRT1 may be resulted from inhibition of miR-138-5p after cells exposed to MnCl₂ . Finally, we found that SIRT1 inhibitor EX-527 suppressed Mn-induced autophagy as well as miR-138-5p, while the suppression was reversed by SIRT1-specific activator SRT1720. These results indicated that overexpression of miR-138-5p suppressed Mn-induced autophagy by targeting SIRT1.

The geranyl acetophenone tHGA attenuates human bronchial smooth muscle proliferation via inhibition of AKT phosphorylation

Increased airway smooth muscle (ASM) mass is a prominent hallmark of airway remodeling in asthma. Inhaled corticosteroids and long-acting beta₂-agonists remain the mainstay of asthma therapy, however are not curative and ineffective in attenuating airway remodeling. The geranyl acetophenone 2,4,6-trihydroxy-3-geranyl acetophenone (tHGA), an in-house synthetic non-steroidal compound, attenuates airway hyperresponsiveness and remodeling in murine models of asthma. The effect of tHGA upon human ASM proliferation, migration and survival in response to growth factors was assessed and its molecular target was determined. Following serum starvation and induction with growth factors, proliferation and migration of human bronchial smooth muscle cells (hBSMCs) treated with tHGA were significantly inhibited without any significant effects upon cell survival. tHGA caused arrest of hBSMC proliferation at the G₁ phase of the cell cycle with downregulation of cell cycle proteins, cyclin D1 and diminished degradation of cyclin-dependent kinase inhibitor (CKI), p27^Kip1. The inhibitory effect of tHGA was demonstrated to be related to its direct inhibition of AKT phosphorylation, as well as inhibition of JNK and STAT3 signal transduction. Our findings highlight the anti-remodeling potential of this drug lead in chronic airway disease.

Epigenetic Changes in Airway Smooth Muscle as a Driver of Airway Inflammation and Remodeling in Asthma

Epigenetic changes are heritable changes in gene expression, without changing the DNA sequence. Epigenetic processes provide a critical link between environmental insults to the airway and functional changes that determine how airway cells respond to future stimuli. There are three primary epigenetic processes: histone modifications, DNA modification, and noncoding RNAs. Airway smooth muscle has several important roles in the development and maintenance of the pathologic processes occurring in asthma, including inflammation, remodeling, and contraction/hyperresponsiveness. In this review, we describe the evidence for the role of epigenetic changes in driving these processes in airway smooth muscle cells in asthma, with a particular focus on histone modifications. We also discuss how existing therapies may target some of these changes and how epigenetic processes provide targets for the development of novel asthma therapeutics. Epigenetic marks may also provide a biomarker to assess phenotype and treatment responses.

MiR-216a inhibits proliferation and promotes apoptosis of human airway smooth muscle cells by targeting JAK2

Objective: Accumulating evidence suggests that aberrantly expressed microRNAs in airway smooth muscle (ASM) cells could change airway remodeling during the development of asthma. However, the underlying functions of microRNAs in ASM cell proliferation and apoptosis need to be further elucidated. Methods: By using RT-qPCR, miR-216a expression level was examined in the asthmatic patients and non-asthmatic individuals. Cell proliferation assay and flow cytometry analysis were used in ASM cells in which miR-216a was an abnormal expression. MiR-216a predicted to target gene was explored by bioinformatic software, and further analyzed by Western blotting and luciferase reporter assay. Results: Our results demonstrated that miR-216a levels were considerably lower in the ASM cells of asthmatic patients than in those of non-asthmatic individuals. Further study verified that the overexpression of miR-216a markedly suppressed cell proliferation and promoted cell apoptosis, whereas the knockdown of miR-216a had opposite effects in ASM cells. In addition, luciferase reporter assays and Western blotting identified that JAK2 was the direct functional target of miR-216a, and the ectopic expression of JAK2 partially rescued the inhibitory effect of miR-216a in ASM cells. Conclusions: The above data indicate that miR-216a may function as a key regulator of airway remodeling by targeting JAK2, thus suggesting the potential role of miR-216a in the pathogenesis of asthma.

Downregulation of microRNA‑182 inhibits cell viability, invasion and angiogenesis in retinoblastoma through inhibition of the PI3K/AKT pathway and CADM2 upregulation

Retinoblastoma (RB) is a well‑vascularized tumor dependent on angiogenesis. The present study aimed to explore whether microRNA (miR)‑182 regulates cell viability, invasion and angiogenesis in RB via the phosphatidylinositol‑3‑OH kinase (PI3K)/protein kinase B (AKT) signaling pathway and by targeting cell adhesion molecule 2 (CADM2). The expression levels of miR‑182 and CADM2 were initially detected in RB tissues from patients with RB who underwent ophthalmectomy, and normal retinal tissues collected from other trauma patients who underwent eye enucleation. To determine whether CADM2 was targeted by miR‑182, a dual luciferase reporter assay was conducted. Subsequently, Y79 and WERI‑Rb‑1 RB cells were transfected with a miR‑182 mimic or miR‑182 inhibitor, or small interfering RNA against CADM2, in order to investigate the effects of miR‑182 on viability and invasion, which were detected using MTT and Transwell assays, respectively. In addition, to determine whether the regulatory mechanism underlying the effects of miR‑182 was associated with the PI3K/AKT signaling pathway, the expression levels of associated genes were detected by reverse transcription‑quantitative polymerase chain reaction and western blot analysis. A xenograft tumor model in nude mice was also established, in order to evaluate the effects of miR‑182 on tumor growth and angiogenesis. The results indicated that miR‑182 expression was increased and CADM2 expression was reduced in RB tissues; CADM2 was confirmed to be targeted and negatively regulated by miR‑182. When the expression of miR‑182 was downregulated, cell viability, invasion, tumor volume and angiogenesis were significantly decreased. Furthermore, the expression levels of PI3K/AKT signaling pathway‑associated genes were increased in response to miR‑182 overexpression or CADM2 silencing. Taken together, these results suggested that inhibition of miR‑182 may suppress cell viability, invasion and angiogenesis in RB through inactivation of the PI3K/AKT pathway and CADM2 upregulation. This mechanism may reveal a novel potential therapeutic target.

MicroRNA-590-5p represses proliferation of human fetal airway smooth muscle cells by targeting signal transducer and activator of transcription 3

INTRODUCTION

Pediatric asthma has remained a health threat to children in recent years. The abnormal proliferation of airway smooth muscle (ASM) cells contributes to airway remodeling during development of asthma. MicroRNAs (miRNAs) are critical regulators of ASM cell proliferation during airway remodeling. miR-590-5p has been reported to regulate cell proliferation in various cell types. However, it remains unclear whether miR-590-5p regulates ASM cell proliferation. In this study, we aimed to investigate the potential role of miR-590-5p in regulating fetal ASM cell proliferation in vitro stimulated by platelet-derived growth factor (PDGF).

MATERIAL AND METHODS

miRNA, mRNA, and protein expression was detected by real-time quantitative polymerase chain reaction and western blot. Cell proliferation was detected by CCK-8 and BrdU assays. The target of miR-590-5p was confirmed by dual-luciferase reporter assay.

RESULTS

MiR-590-5p expression was significantly down-regulated in fetal ASM cells stimulated with PDGF (p < 0.05). Overexpression of miR-590-5p inhibited cell proliferation (p < 0.05), whereas the suppression of miR-590-5p promoted cell proliferation of fetal ASM cells stimulated with PDGF (p < 0.05). Signal transducer and activator of transcription 3 (STAT3) was identified as a target gene of miR-590-5p. In addition, miR-590-5p negatively regulated STAT3 expression (p < 0.05). Moreover, miR-590-5p also modulated downstream genes of STAT3 including cyclin D3 and p27 (p < 0.05). The restoration of STAT3 significantly reversed the inhibitory effect of miR-590-5p on fetal ASM cell proliferation.

CONCLUSIONS

MiR-590-5p inhibits proliferation of fetal ASM cells by down-regulating STAT3, thereby suggesting a novel therapeutic target for the treatment of pediatric asthma.

Extracellular matrix promotes proliferation, migration and adhesion of airway smooth muscle cells in a rat model of chronic obstructive pulmonary disease via upregulation of the PI3K/AKT signaling pathway

Extracellular matrix (ECM) creates the tissue microenvironment and serves a role in airway wall remodeling in chronic obstructive pulmonary disease (COPD). However, the biological function of ECM in COPD remains to be elucidated. In the present study, 24 healthy Sprague Dawley rats were randomized to normal and COPD groups. COPD was established by intratracheal injection with lipopolysaccharide over 30 days. Subsequently, airway smooth muscle cells (ASMCs) were isolated from rats and served as a model to assess the effects of three ECM components, including collagen type I, laminin and collagen type III (COL‑3). Functional analysis in vitro, using cell counting kit‑8, flow cytometry, wound healing and cell adhesion assays indicated that the ECM components could promote cell proliferation, cell cycle progression, migration and adhesion ability, respectively. Furthermore, as demonstrated by ELISA, treatment with ECM components increased levels of C‑X‑C motif chemokine ligand 1 (CXCL1), CXCL8 and interleukin‑6 in ASMCs. Expression of transforming growth factor β1 (TGFβ1), fibroblast growth factor‑1 (FGF‑1) and tissue inhibitor of metalloproteinase 1 (TIMP1) was increased, and expression of matrix metalloproteinase‑9 (MMP‑9) was decreased following treatment with ECM components, as demonstrated by reverse transcription‑quantitative polymerase chain reaction and western blot analysis. Additionally, specific activation of phosphoinositide 3‑kinase (PI3K) signaling, using insulin‑like growth factor‑1 (IGF‑1), promoted cell proliferation and cell cycle progression, increased expression of TGFβ1, FGF‑1, PI3K, AKT, phospho‑AKT, serine/threonine‑protein kinase mTOR (mTOR), phospho‑mTOR and TIMP1, promoted cell migration capacity and reduced the expression level of MMP‑9 in cells from COPD rats. Consistently, PI3K inhibitor LY294002 exerted the opposite effect to IGF‑1. In conclusion, ECM proteins promoted proliferation, migration and adhesion of ASMCs form rat models of COPD through activation of the PI3K/AKT signaling pathway.

Mechanism of Yanghe Pingchuan granules treatment for airway remodeling in asthma

Purpose

Yanghe Pingchuan granules (YPG), a hospital preparation developed by The First Affiliated Hospital, Anhui University of Chinese Medicine, has been used for the clinical treatment of bronchial asthma (BA) for several decades. This study aimed to explore the mechanism of action of YPG in the treatment of BA.

Materials and methods

Male Sprague Dawley rats (n=60) were randomly divided into six groups (n=10 per group): control, a BA model, positive drug control (Guilong Kechuanning capsules; a proven effective treatment for BA), and model rats treated with a high, medium, or low dose of YPG. H&E staining was used to detect pathological changes in the bronchial tubes. The mRNA expression levels of PI3K, PKB, PCNA, and AR were determined by real-time PCR, and the protein levels of phospho- (p-)PI3K, p-PKB, p-PCNA, and p-AR were detected by Western blotting. ELISAs were used to detect the expression of PIP2, PIP3 IL-6, IL-8, IL-1β, and epinephrine (EPI).

Results

H&E staining demonstrated that BA can be ameliorated using YPG. Real-time PCR, Western blotting, and ELISA indicated that use of YPG decreased expression of the phosphoinositide 3-kinase (PI3K) signaling pathway and PCNA, and can also ameliorate the condition kidney Yang deficiency, which is associated with BA in Chinese traditional medicine.

Conclusion

YPG can attenuate BA therapeutically in a dose-dependent manner. The mechanism underlying its therapeutic effect comprises influences on three features that contribute to BA: the PI3K signaling pathway, cell proliferation, and “kidney-Yang deficiency”.

A systems immunology approach identifies the collective impact of 5 miRs in Th2 inflammation

Allergic asthma is a chronic inflammatory disease dominated by a CD4+ T helper 2 (Th2) cell signature. The immune response amplifies in self-enforcing loops, promoting Th2-driven cellular immunity and leaving the host unable to terminate inflammation. Posttranscriptional mechanisms, including microRNAs (miRs), are pivotal in maintaining immune homeostasis. Since an altered expression of various miRs has been associated with T cell-driven diseases, including asthma, we hypothesized that miRs control mechanisms ensuring Th2 stability and maintenance in the lung. We isolated murine CD4+ Th2 cells from allergic inflamed lungs and profiled gene and miR expression. Instead of focusing on the magnitude of miR differential expression, here we addressed the secondary consequences for the set of molecular interactions in the cell, the interactome. We developed the Impact of Differential Expression Across Layers, a network-based algorithm to prioritize disease-relevant miRs based on the central role of their targets in the molecular interactome. This method identified 5 Th2-related miRs (mir27b, mir206, mir106b, mir203, and mir23b) whose antagonization led to a sharp reduction of the Th2 phenotype. Overall, a systems biology tool was developed and validated, highlighting the role of miRs in Th2-driven immune response. This result offers potentially novel approaches for therapeutic interventions.

MicroRNA-20b-5p inhibits platelet-derived growth factor-induced proliferation of human fetal airway smooth muscle cells by targeting signal transducer and activator of transcription 3

Pediatric asthma is still a health threat to the pediatric population in recent years. The airway remodeling induced by abnormal airway smooth muscle (ASM) cell proliferation is an important cause of asthma. MicroRNAs (miRNAs) are important regulators of ASM cell proliferation. Numerous studies have reported that miR-20b-5p is a critical regulator for cell proliferation. However, whether miR-20b-5p is involved in regulating ASM cell proliferation remains unknown. In this study, we aimed to investigate the potential role of miR-20b-5p in regulating the proliferation of fetal ASM cell induced by platelet-derived growth factor (PDGF). Here, we showed that miR-20b-5p was significantly decreased in fetal ASM cells treated with PDGF. Biological experiments showed that the overexpression of miR-20b-5p inhibited the proliferation while miR-20b-5p inhibition markedly promoted the proliferation of fetal ASM cells. Bioinformatics analysis and luciferase reporter assay showed that miR-20b-5p directly targeted the 3'-UTR of signal transducer and activator of transcription 3 (STAT3). Further data showed that miR-20b-5p negatively regulated the expression of STAT3 in fetal ASM cells. Moreover, miR-20b-5p regulates the transcriptional activity of STAT3 in fetal ASM cells. Overexpression of STAT3 reversed the inhibitory effect of miR-20b-5p overexpression on fetal ASM cell proliferation while the knockdown of STAT3 abrogated the promoted effect of miR-20b-5p inhibition on fetal ASM cell proliferation. Overall, our results show that miR-20b-5p impedes PDGF-induced proliferation of fetal ASM cells through targeting STAT3. Our study suggests that miR-20b-5p may play an important role in airway remodeling during asthma and suggests that miR-20b-5p may serve as a potential therapeutic target for pediatric asthma.

Egr2-dependent microRNA-138 is dispensable for peripheral nerve myelination

Recent studies have elucidated the crucial role for microRNAs in peripheral nerve myelination by ablating components of the microRNA synthesis machinery. Few studies have focused on the role of individual microRNAs. To fill this gap, we focused this study on miR-138, which was shown to be drastically reduced in Dicer1 and Dgcr8 knockout mice with hypomyelinating phenotypes and to potentially target the negative regulators of Schwann cell differentiation. Here, we show that of two miR-138 encoding loci, mir-138-1 is the predominant locus transcribed in Schwann cells. mir-138-1 is transcriptionally upregulated during myelination and downregulated upon nerve injury. EGR2 is required for mir-138-1 transcription during development, and both SOX10 and EGR2 bind to an active enhancer near the mir-138-1 locus. Based on expression analyses, we hypothesized that miR-138 facilitates the transition between undifferentiated Schwann cells and myelinating Schwann cells. However, in conditional knockouts, we could not detect significant changes in Schwann cell proliferation, cell cycle exit, or myelination. Overall, our results demonstrate that miR-138 is an Egr2-dependent microRNA but is dispensable for Schwann cell myelination.

Targeting IGF1R pathway in cancer with microRNAs: How close are we?

Cancer of the head and neck are the most common cancers in India and account for 30% of all cancers. At molecular level, it could be attributed to the overexpression of growth factors like IGF1-R, EGFR, VEGF-R and deregulation of cell cycle regulators and tumor suppressors. IGF1-R is an emerging target in head and neck cancer treatment, because of its reported role in tumor development, progression and metastasis. IGF1R targeted agents are in advanced stages of clinical development. Nevertheless, these agents suffer from several disadvantages including acquired resistance and toxic side effects. Hence there is a need for developing newer agents targeting not only the receptor but also its downstream signaling. miRNAs are considered as master regulators of gene expression of multiple genes and has been widely reported to be a promising therapeutic strategy. This review discusses the present status of research in both these arenas and emphasizes the role of miRNA as a promising agent for biologic therapy.

Integrated analysis of mRNA-seq and miRNA-seq reveals the potential roles of sex-biased miRNA-mRNA pairs in gonad tissue of dark sleeper (Odontobutis potamophila)

Background

The dark sleeper (Odontobutis potamophila) is an important commercial fish species which shows a sexually dimorphic growth pattern. However, the lack of sex transcriptomic data is hindering further research and genetically selective breeding of the dark sleeper. In this study, integrated analysis of mRNA and miRNA was performed on gonad tissue to elucidate the molecular mechanisms of sex determination and differentiation in the dark sleeper.

Results

A total of 143 differentially expressed miRNAs and 16,540 differentially expressed genes were identified. Of these, 8103 mRNAs and 75 miRNAs were upregulated in testes, and 8437 mRNAs and 68 miRNAs were upregulated in ovaries. Integrated analysis of miRNA and mRNA expression profiles predicted more than 50,000 miRNA-mRNA interaction sites, and among them 27,583 negative miRNA-mRNA interactions. A number of sex related genes were targeted by sex-biased miRNAs. The relationship between 15 sex-biased genes and 15 sex-biased miRNAs verified by using qRT-PCR were described. Additionally, a number of SNPs were revealed through the transcriptome data.

Conclusions

The overall results of this study facilitate our understanding of the molecular mechanism underlying sex determination and differentiation and provide valuable genomic information for selective breeding of the dark sleeper.

Electronic supplementary material

The online version of this article (doi:10.1186/s12864-017-3995-9) contains supplementary material, which is available to authorized users.

Overexpression of microRNA-138 alleviates human coronary artery endothelial cell injury and inflammatory response by inhibiting the PI3K/Akt/eNOS pathway

This study aimed to investigate the role of miR‐138 in human coronary artery endothelial cell (HCAEC) injury and inflammatory response and the involvement of the PI3K/Akt/eNOS signalling pathway. Oxidized low‐density lipoprotein (OX‐LDL)‐induced HCAEC injury models were established and assigned to blank, miR‐138 mimic, miR‐138 inhibitor, LY294002 (an inhibitor of the PI3K/Akt/eNOS pathway), miR‐138 inhibitor + LY294002 and negative control (NC) groups. qRT‐PCR and Western blotting were performed to detect the miR‐138, PI3K, Akt and eNOS levels and the protein expressions of PI3K, Akt, eNOS, p‐Akt, p‐eNOS, Bcl‐2, Bax and caspase‐3. ELISAs were employed to measure the expressions of TNF‐α, IL‐4, IL‐6, IL‐8, IL‐10 and nitric oxide (NO) and the activities of lactate dehydrogenase (LDH) and eNOS. MTT and flow cytometry were performed to assess the proliferation and apoptosis of HCAECs. Compared to the blank group, PI3K, Akt and eNOS were down‐regulated in the miR‐138 mimic and LY294002 groups but were up‐regulated in the miR‐138 inhibitor group. The miR‐138 mimic and LY294002 groups showed decreased concentrations of TNF‐α, IL‐6, IL‐8 and NO and reduced activities of LDH and eNOS, while opposite trends were observed in the miR‐138 inhibitor group. The concentrations of IL‐4 and IL‐10 increased in the miR‐138 mimic and LY294002 groups but decreased in the miR‐138 inhibitor group. The miR‐138 mimic and LY294002 groups had significantly decreased cell proliferation and increased cell apoptosis compared to the blank group. These findings indicate that up‐regulation of miR‐138 alleviates HCAEC injury and inflammatory response by inhibiting the PI3K/Akt/eNOS signalling pathway.

Emerging concepts in smooth muscle contributions to airway structure and function: implications for health and disease

Airway structure and function are key aspects of normal lung development, growth, and aging, as well as of lung responses to the environment and the pathophysiology of important diseases such as asthma, chronic obstructive pulmonary disease, and fibrosis. In this regard, the contributions of airway smooth muscle (ASM) are both functional, in the context of airway contractility and relaxation, as well as synthetic, involving production and modulation of extracellular components, modulation of the local immune environment, cellular contribution to airway structure, and, finally, interactions with other airway cell types such as epithelium, fibroblasts, and nerves. These ASM contributions are now found to be critical in airway hyperresponsiveness and remodeling that occur in lung diseases. This review emphasizes established and recent discoveries that underline the central role of ASM and sets the stage for future research toward understanding how ASM plays a central role by being both upstream and downstream in the many interactive processes that determine airway structure and function in health and disease.

Molecular Background of miRNA Role in Asthma and COPD: An Updated Insight

Inflammatory airway diseases are a significant health problems requiring new approaches to the existing therapies and addressing fundamental issues. Difficulties in developing effective therapeutic strategies might be caused by lack of understanding of their exact molecular mechanism. MicroRNAs (miRNAs) are a class of regulators that already revolutionized the view of gene expression regulation. A cumulating number of investigations show a pivotal role of miRNAs in the pathogenesis of asthma, chronic obstructive pulmonary disease (COPD), or airway remodeling through the regulation of many pathways involved in their pathogenesis. Expression changes of several miRNAs have also been found to play a role in the development and/or improvement in asthma or COPD. Still, relatively little is known about the role of miRNAs in inflammatory disorders. The microRNA profiles may differ depending on the cell type or antigen-presenting cell. Based on the newest literature, this review discusses the current knowledge concerning miRNA contribution and influence on lung inflammation and chosen inflammatory airway diseases: asthma and COPD.

MicroRNA‑205 promotes the tumorigenesis of nasopharyngeal carcinoma through targeting tumor protein p53-inducible nuclear protein 1

Nasopharyngeal carcinoma (NPC) is a common type of cancer in southern China, miRNAs have been shown to be involved in the tumorigenesis of multiple cancer types. The present study aimed to explore the potential role of miR‑205 in NPC. Reverse transcription quantitative polymerase chain reaction was used to determine the expression levels of miR‑205 in 20 fresh NPC specimens and 20 normal nasopharyngeal tissues. The function of miR‑205 in the proliferation, migration, invasion and apoptosis of NPC‑derived cells was detected by MTT assay, colony formation assay, wound healing assay, Transwell assay and flow cytometry. Furthermore, a target gene of miR‑205 was identified using the luciferase reporter assay. The expression of miR‑205 was increased in NPC tissues compared with that in normal tissues. Overexpression of miR‑205 was found to promote the proliferation, migration and invasion of NPC‑derived cells, while apoptosis was suppressed. Tumor protein p53-inducible nuclear protein 1 was identified as a target gene of miR‑205. Overall, the present study demonstrated that miR‑205 may function as an oncogene in NPC tumorigenesis.