MicroRNA-638 inhibits human airway smooth muscle cell proliferation and migration through targeting cyclin D1 and NOR1

Targeting PDGF/PDGFR Signaling Pathway by microRNA, lncRNA, and circRNA for Therapy of Vascular Diseases: A Narrow Review

Despite the significant progress in diagnostic and therapeutic strategies, vascular diseases, such as cardiovascular diseases (CVDs) and respiratory diseases, still cannot be successfully eliminated. Vascular cells play a key role in maintaining vascular homeostasis. Notably, a variety of cells produce and secrete platelet-derived growth factors (PDGFs), which promote mitosis and induce the division, proliferation, and migration of vascular cells including vascular smooth muscle cells (SMCs), aortic SMCs, endothelial cells, and airway SMCs. Therefore, PDGF/PDGR receptor signaling pathways play vital roles in regulating the homeostasis of blood vessels and the onset and development of CVDs, such as atherosclerosis, and respiratory diseases including asthma and pulmonary arterial hypertension. Recently, accumulating evidence has demonstrated that microRNA, long-chain non-coding RNA, and circular RNA are involved in the regulation of PDGF/PDGFR signaling pathways through competitive interactions with target mRNAs, contributing to the occurrence and development of the above-mentioned diseases. These novel findings are useful for laboratory research and clinical studies. The aim of this article is to conclude the recent progresses in this field, particular the mechanisms of action of these non-coding RNAs in regulating vascular remodeling, providing potential strategies for the diagnosis, prevention, and treatment of vascular-dysfunction-related diseases, particularly CVDs and respiratory diseases.

Nur77 Mediates Anaphylaxis by Regulating miR-21a

Nur77 belongs to the NR4A subfamily of orphan nuclear hormone receptors. It has been shown to play important roles in metabolism, cancer progression, cellular differentiation, and the regulation of immune process. However, there has yet to be research reporting on the role of Nur77 in allergic inflammations such as anaphylaxis. This study aimed to identify molecules that could mediate allergic inflammations. To this end, we performed RNA sequencing analysis employing bone marrow-derived mast cells (BMMCs). Antigen (DNP-HSA) stimulation increased the expression levels of transcription factors such as Nr4a3 (NOR1), Nr4a1 (Nur77), and Nr4a2 (Nurr1). We focused our study on Nur77. Antigen stimulation increased the expression of Nur77 in a time- and dose-dependent manner in rat basophilic leukemia cells (RBL2H3). The downregulation of Nur77 prevented both antigen-induced increase in β-hexosaminidase activity as well as hallmarks of allergic reactions such as HDAC3, COX2, and MCP1 in RBL2H3 cells. Nur77 was necessary for both passive cutaneous anaphylaxis (PCA) and passive systemic anaphylaxis (PSA). TargetScan analysis predicted that miR-21a would be a negative regulator of Nur77. miR-21a mimic negatively regulated PCA and PSA by inhibiting the hallmarks of allergic reactions. ChIP assays showed that c-JUN could bind to the promoter sequences of Nur77. Antigen stimulation increased the expression of c-JUN in RBL2H3 cells. Altogether, our findings demonstrate the regulatory role played by Nur77-miR-21a loop in allergic inflammations such as anaphylaxis, making this the first report to present the role played by Nur77 in an allergic inflammation. Our results suggest that Nur77 and miR-21 might serve as targets for developing anti-allergy drugs.

Notoginsenoside R1 restrains the proliferation and migration of airway smooth muscle cells isolated from rats with chronic obstructive pulmonary disease

OBJECTIVE

Chronic obstructive pulmonary disease (COPD) is a common disorder that is characterized by systemic and lung inflammation. Notoginsenoside R1 (NGR1) displays anti-inflammatory properties in numerous diseases. We aimed to explore the function and mechanism of NGR1 in COPD.

MATERIALS AND METHODS

COPD rats were established through cigarette smoke exposure, lipopolysaccharide injection, and cold stimulation. Rat airway smooth muscle cells (ASMCs) were separated and identified. Then, ASMCs were treated with NGR1 (25 or 50 μM) and cigarette smoke extract (CSE). Thereafter, the vitality, proliferation, and migration of ASMCs were measured. Additionally, cell cycle, inflammation-related factors, α-SMA, and PI3K/AKT pathway-related marker expressions of the ASMCs were also detected. Molecular docking experiments were conducted to explore the interaction of NGR1 to PI3K, TGF-β, p65, and AKT. Moreover, 740 Y-P (a PI3K/Akt pathway agonist) were used to validate the mechanism of NGR1 on COPD.

RESULTS

NGR1 inhibited the proliferation and migration, but caused cell cycle arrest for CSE-triggered ASMCs. Furthermore, NGR1 not only decreased IL-1β, IL-6, IL-8, and TNF-α contents, but also reduced α-SMA expression in CSE-stimulated ASMCs. Moreover, NGR1restrainedTGF-β1 expression, PI3K, p65, and AKT phosphorylation in CSE-stimulated ASMCs. Molecular docking experiments showed NGR1 exhibited a strong binding ability to PI3K, TGF-β1, p65, and AKT. Notably, the effects of NGR1 on the proliferation and migration of CSE-induced ASMCs were reversed by 740 Y-P.

CONCLUSIONS

NGR1 can restrain the proliferation and migration of CSE-induced ASMCs, indicating that NGR1 may be a therapeutic candidate for treating COPD.

Cysteine and glycine-rich protein 2 retards platelet-derived growth factor-BB-evoked phenotypic transition of airway smooth muscle cells by decreasing YAP/TAZ activity

Cysteine and glycine-rich protein 2 (Csrp2) has emerged as a key factor in controlling the phenotypic modulation of smooth muscle cells. The phenotypic transition of airway smooth muscle cells (ASMCs) is a pivotal step in developing airway remodeling during the onset of asthma. However, whether Csrp2 mediates the phenotypic transition of ASMCs in airway remodeling during asthma onset is undetermined. This work aimed to address the link between Csrp2 and the phenotypic transition of ASMCs evoked by platelet-derived growth factor (PDGF)-BB in vitro. The overexpression or silencing of Csrp2 in ASMCs was achieved through adenovirus-mediated gene transfer. The expression of mRNA was measured by quantitative real-time-PCR. Protein levels were determined through Western blot analysis. Cell proliferation was detected by EdU assay and Calcein AM assays. Cell cycle distribution was assessed via fluorescence-activated cell sorting assay. Cell migration was evaluated using the scratch-wound assay. The transcriptional activity of Yes-associated protein (YAP)/transcriptional coactivator with PDZ-binding motif (TAZ) was measured using the luciferase reporter assay. A decline in Csrp2 level occurred in PDGF-BB-stimulated ASMCs. Increasing Csrp2 expression repressed the PDGF-BB-evoked proliferation and migration of ASMCs. Moreover, increasing Csrp2 expression impeded the phenotypic change of PDGF-BB-stimulated ASMCs from a contractile phenotype into a synthetic/proliferative phenotype. On the contrary, the opposite effects were observed in Csrp2-silenced ASMCs. The activity of YAP/TAZ was elevated in PDGF-BB-stimulated ASMCs, which was weakened by Csrp2 overexpression or enhanced by Csrp2 silencing. The YAP/TAZ activator could reverse Csrp2-overexpression-mediated suppression of the PDGF-BB-evoked phenotypic switching of ASMCs, while the YAP/TAZ suppressor could dimmish Csrp2-silencing-mediated enhancement on PDGF-BB-evoked phenotypic switching of ASMCs. In summary, Csrp2 serves as a determinant for the phenotypic switching of ASMCs. Increasing Csrp2 is able to impede PDGF-BB-evoked phenotypic change of ASMCs from a synthetic phenotype into a synthetic/proliferative phenotype through the effects on YAP/TAZ. This work implies that Csrp2 may be a key player in airway remodeling during the onset of asthma.

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.

Conventional, Complementary and Alternative Medicines: Mechanistic Insights into Therapeutic Landscape of Chronic Obstructive Pulmonary Disease

COPD (chronic obstructive pulmonary disease) is a major public health concern associated with significant morbidity and mortality worldwide. Current therapeutic guidelines for this disease recommend starting with an inhaled bronchodilator, stepping up to combination therapy as necessary, and/or adding inhaled corticosteroids as symptoms and airflow obstruction progress. However, no drug therapy exists to stop disease progression. The mechanistic definition underlying COPD pathogenesis remains poorly understood, it is generally accepted that oxidative stress and the altered immune response of low-grade airway inflammation are major factors contributing to COPD development. There are several potential therapeutic targets that are currently under investigation, including immune regulatory pathways in inflammation and lung-associated steroid resistance induced by oxidative stress signaling cascades. Patients with COPD have increased levels of inflammatory mediators, including lipid and peptide mediators, as well as a network of cytokines and chemokines that maintain inflammatory immune response and recruit circulating cells into the lungs. Many of these pro-inflammatory mediators are regulated by nuclear factor-kappaB (NF-κB) and mitogen-activated protein kinases (MAPKs), such as p38 MAPK. Increased oxidative stress is a key driving mechanism in perpetuating inflammation and lung injury. Furthermore, many proteases that degrade elastin fibres are secreted by airway resident infiltrating immune cells in COPD patients. In this perspective, we discuss novel aspects of signaling pathway activation in the context of inflammation and oxidative stress, and the broad view of potential effective pharmacotherapies that target the underlying mechanistic disease process in COPD.

The extract from Hyssopus cuspidatus Boriss. Prevents bronchial airway remodeling by inhibiting mouse bronchial wall thickening and hASMC proliferation and migration

ETHNOPHARMACOLOGICAL RELEVANCE

Bronchial asthma, a non-communicable chronic respiratory disease, affects people of all ages. An important pathological feature of bronchial asthma is airway remodeling. Hyssopus cuspidatus Boriss. has been used to treat bronchial asthma for over 100 years in Uygur medicine. The ethanol extract of Hyssopus cuspidatus Boriss.(JAX2) can improve airway inflammation in asthma. However, the anti-asthmatic airway-remodeling effect of JAX2 is unclear.

AIM OF THE STUDY

The current study investigated the anti-airway remodeling effect of JAX2 and elucidated its mechanism of action.

MATERIALS AND METHODS

The present study established an ovalbumin-induced mouse model of asthma and platelet-derived growth factor-BB-induced human airway smooth muscle cells (hASMCs) proliferation model, with dexamethasone (DEX) and feining tablets (FNP) designated as positive control drugs. Pathological changes in lung tissues were observed using hematoxylin and eosin staining. Interleukin (IL)-5, IL-10, IL-13, and IL-33 levels in the bronchoalveolar lavage fluid (BALF) and serum of mice were determined using enzyme-linked immunosorbent assay (ELISA). Changes in the expression and distribution of TGF-β1, p-ERK1/2, Smad2/3, and p-Smad3 in lung tissues were determined using immunohistochemistry. Western blotting (WB) was used to determine the protein levels of p-ERK1/2 in lung tissues and cells. MTS assay was used to determine the effects of JAX2 on cell proliferation. IL-5, IL-10, IL-13, MMP-2, and MMP-9 levels in the cell supernatant were determined using ELISA. HASMCs migration was observed using the scratch and transwell methods. The effect of JAX2 on the hASMCs cycle was determined using flow cytometry.

RESULTS

JAX2 significantly improved the pathological status of lung tissues in asthmatic mice. It could also significantly reduce IL-5, IL-13, and IL-33 levels in the BALF and serum of asthmatic mice in a dose-dependent manner and significantly increase IL-10 levels. TGF-β1, p-ERK1/2, Smad2/3, and p-Smad3 expression in lung tissues were decreased in a dose-dependent manner. The protein level of p-ERK1/2 in lung tissues was also reduced. JAX2 could significantly inhibit the proliferation and migration of PDGF-BB-induced hASMCs. IL-5, IL-13, MMP-9, and MMP-2 levels decreased significantly, and IL-10 levels increased significantly in a dose-dependent manner in the cell supernatant. JAX2 could block hASMCs in the G0/G1 phase, thereby inhibiting cell proliferation. p-ERK1/2 protein levels were found to decrease in a dose-dependent manner.

CONCLUSIONS

JAX2 significantly inhibits airway remodeling in asthma. Its mechanism of action may be inhibiting the proliferation and migration of hASMCs, releasing inflammatory factors and metalloproteinases, activating the ERK1/2 signal pathway, and promoting the secretion of anti-inflammatory factors.

Regulation of oxidized LDL-induced proliferation and migration in human vascular smooth muscle cells by a novel circ_0007478/miR-638/ROCK2 ceRNA network

BACKGROUND

Circular RNAs (circRNAs) have been implicated in the pathogenesis of atherosclerosis (AS) and the migration and proliferation of vascular smooth muscle cells (VSMCs) under oxidized low-density lipoprotein (ox-LDL). Here, we defined the exact action of human circ_0007478 in VSMC migration and proliferation induced by ox-LDL.

METHODS

Human VSMCs (HVSMCs) were exposed to ox-LDL. Circ_0007478, microRNA (miR)-638, and rho-associated protein kinase 2 (ROCK2) levels were gauged by quantitative real-time PCR (qRT-PCR) and western blot. Cell viability and proliferation were assessed by MTT and EdU assays, respectively. Transwell assays were used to detect cell migration and invasion. Dual-luciferase reporter and RNA immunoprecipitation (RIP) assays were used to evaluate the direct relationship between miR-638 and circ_0007478 or ROCK2.

RESULTS

Our data indicated that circ_0007478 expression was augmented in AS serum samples and ox-LDL-treated HVSMCs. Depletion of circ_0007478 attenuated HVSMC proliferation, migration, and invasion induced by ox-LDL. Mechanistically, circ_0007478 targeted miR-638 by directly pairing to miR-638. Reduction of miR-638 reversed the effects of circ_0007478 depletion on ox-LDL-evoked proliferation, migration, and invasion in HVSMCs. ROCK2 was a direct miR-638 target and miR-638-mediated inhibition of ROCK2 relieved ox-LDL-evoked HVSMC proliferation, migration, and invasion. Furthermore, circ_0007478 was identified as a competing endogenous RNA (ceRNA) for miR-638 to modulate ROCK2 expression.

CONCLUSION

Our present study establishes an undescribed ceRNA regulatory network, in which circ_0007478 targets miR-638 to upregulate ROCK2, thereby contributing to ox-LDL-induced proliferation and migration in HVSMCs.

MiR-140-3p Ameliorates The Inflammatory Response of Airway Smooth Muscle Cells by Targeting HMGB1 to Regulate The JAK2/STAT3 Signaling Pathway

OBJECTIVE

The growth and migration of airway smooth muscle cells (ASMCs) are dysregulated in asthma. MicroRNAs (miRNAs) are associated with the pathogenesis of many diseases including asthma. Instead, the function of miR-140- 3pin ASMCs' dysregulation in asthma remains inconclusive. This study aimed to explore the role and mechanism of miR-140-3p in ASMCs' dysregulation.

MATERIALS AND METHODS

In this experimental study, ASMCs were stimulated with platelet-derived growth factor (PDGF)- BB to construct an asthma cell model in vitro. MiR-140-3p expression level in the plasma of 50 asthmatic patients and 50 healthy volunteers was measured with quantitative real-time polymerase chain reaction (qRT-PCR). Besides, the enzyme-linked immunosorbent assay (ELISA) was applied to detect the contents of interleukin (IL) -1β, IL-6, and tumor necrosis factor-α (TNF-α) in the cell culture supernatant of ASMCs. Additionally, CCK-8 and transwell assays were adopted to probe the multiplication and migration of ASMCs. In addition, the western blot was employed to examine HMGB1, JAK2, and STAT3 protein expressions in ASMCs after miR-140-3p and HMGB1 were selectively regulated.

RESULTS

miR-140-3p expression was declined in asthmatic patients' plasma and ASMCs stimulated by PDGF-BB. Upregulating miR-140-3p suppressed the viability and migration of the cells and alleviated the inflammatory response while inhibiting miR-140-3p showed opposite effects. Additionally, HMGB1 was testified as the target of miR-140-3p. HMGB1 overexpression could reverse the impact of miR-140-3p upregulation on the inflammatory response of ASMCs stimulated by PDGF-BB. MiR-140-3p could repress the activation of JAK2/STAT3 via suppressing HMGB1.

CONCLUSION

In ASMCs, miR-140-3p can inhibit the JAK2/STAT3 signaling pathway by targeting HMGB1, thus ameliorating airway inflammation and remodeling in the pathogenesis of asthma.

Nuclear receptor NOR-1 (Neuron-derived Orphan Receptor-1) in pathological vascular remodelling and vascular remodelling

Vascular cells and their interaction with inflammatory cells and the immune system play a key role in pathological vascular remodeling. A large number of genes and proteins regulated in a coordinated manner by a small number of transcription factors are involved in this process. In recent years, research on a small subfamily of transcription factors, the NR4A subfamily, has had a major impact on our understanding of vascular biology. The NR4A1 (Nur77), NR4A2 (Nurr1) and NR4A3 (NOR-1) receptors are products of early response genes whose expression is induced by multiple pathophysiological and physical stimuli. Their wide distribution in different tissues and cells places them in the control of numerous processes such as cell differentiation, proliferation, survival and apoptosis, as well as inflammation and the metabolism of lipids and carbohydrates. This review analyzes the role of these receptors, particularly NOR-1, in pathological vascular remodeling associated with atherosclerosis, abdominal aortic aneurysm and pulmonary arterial hypertension.

Long noncoding RNA ANRIL up-regulates CCND1 via sponging miR-98-5p to promote TGF-β1-induced human airway smooth muscle cell proliferation, migration, and extracellular matrix deposition

Excessive proliferation and migration of airway smooth muscle cell (ASMC) contribute to asthma pathogenesis. Long noncoding RNAs (lncRNAs) are reported to take part in asthma pathogenesis. This study is targeted at deciphering the role of the lncRNA antisense noncoding RNA in the INK4 locus (ANRIL) in ASMC proliferation, migration and extracellular matrix (ECM) deposition. qRT-PCR was performed to determine ANRIL, miR-98-5p, and cyclin D1 (CCND1) mRNA expression levels in transforming growth factor-β1 (TGF-β1)-treated ASMCs. CCK-8 and Transwell assays were employed to examine ASMC proliferation and migration, respectively. Dual-luciferase reporter gene assay and RNA immunoprecipitation assay were carried out for analyzing the targeted relationship of miR-98-5p with ANRIL or CCND1 mRNA 3'-UTR. The levels of CCND1 and ECM proteins (such as fibronectin, COL3A1, and COL1A2) in ASMCs were detected through Western blot. In this work, we found that ANRIL and CCND1 were up-regulated in TGF-β1-treated ASMCs, whereas miR-98-5p was down-regulated. ANRIL overexpression facilitated the proliferation, ECM deposition and migration of TGF-β1-induced ASMCs, while knocking down ANRIL had the opposite effect. Furthermore, ANRIL targeted miR-98-5p directly, and CCND1 was miR-98-5p's downstream target. ANRIL indirectly increased CCND1 expression in ASMCs via competitively binding to miR-98-5p. MiR-98-5p inhibition or CCND1 overexpression counteracted the inhibiting effect that ANRIL knockdown had on TGF-β1-stimulated ASMC proliferation, migration and ECM deposition. In conclusion, ANRIL indirectly up-regulates CCND1 expression by targeting miR-98-5p to promote ASMC proliferation, migration and ECM deposition, thus facilitating the pathogenesis of asthma.

MicroRNA-98-5p Inhibits IL-13-Induced Proliferation and Migration of Human Airway Smooth Muscle Cells by Targeting RAC1

The dysfunction of airway smooth muscle cells (ASMCs) is one of the key factors in the pathogenesis of asthma. How miR-98-5p works in asthma has not been completely elucidated. This work focused on how miR-98-5p functions in the proliferation and migration of human ASMCs treated with interleukin-13 (IL-13). MiR-98-5p expression in plasma of asthmatic patients and IL-13-stimulated ASMCs was probed by quantitative real-time polymerase chain reaction (qRT-PCR). RAS-relevant C3 botulinum toxin substrate 1 (RAC1) protein expression in ASMCs was assessed by Western blot. The growth of ASMCs was measured by cell counting kit-8 (CCK-8) assay and 5-ethynyl-2'-deoxyuridine (EdU) assay. The migration of ASMCs was examined by Transwell assay. Besides, the apoptosis of ASMCs was analyzed by flow cytometry. The targeting relationship between miR-98-5p and RAC1 3'-UTR was verified by a dual-luciferase reporter gene assay. MiR-98-5p expression was reduced in patients' plasma and IL-13-stimulated ASMCs, and RAC1 expression was upregulated in ASMCs treated with IL-13. MiR-98-5p overexpression inhibited IL-13-induced proliferation and migration of ASMCs while promoting the apoptosis. The opposite result was observed after inhibiting miR-98-5p expression. Besides, RAC1 was identified as a direct downstream target of miR-98-5p in ASMCs. The restoration of RAC1 expression counteracted the impacts of miR-98-5p overexpression on IL-13-stimulated proliferation, migration, and apoptosis of ASMCs. MiR-98-5p inhibits IL-13-induced proliferation and migration and accelerates the apoptosis of ASMCs by downregulating RAC1 expression.

MicroRNA-885-3p alleviates bronchial epithelial cell injury induced by lipopolysaccharide via toll-like receptor 4

Airway inflammation is one of the typical pathological characteristics of asthma. MicroRNAs (miRNAs) play important roles in regulating inflammation. Nevertheless, miRNA-885-3p (miR-885-3p)’s role in asthmatic inflammation and the underlying mechanism need to be explained. In this work, miR-885-3p expression and toll-like receptor 4 (TLR4) expression in asthma patients’ plasma and lipopolysaccharide (LPS)-treated 16HBE cells were detected through quantitative real-time PCR. The interleukin-8 (IL-8), tumor necrosis factor-α (TNF-α) and interleukin-6 (IL-6) levels in 16HBE cell supernatant were examined via enzyme-linked immunosorbent assay. Cell counting kit-8 (CCK-8) assay and flow cytometry were employed to examine 16HBE cell viability and apoptosis, respectively. Western blotting was performed to examine the expression of TLR4, cleaved caspase-3, B-cell lymphoma-2 (Bcl-2), nuclear factor-kappa B (NF-κB) p65, Bcl-2-related X protein (Bax), phosphorylated (p)-NF-κB p65 and myeloid differentiation primitive-response protein 88 (MyD88) in 16HBE cells. Furthermore, the targeted relationship between TLR4 and miR-885-3p in 16HBE cells was determined through dual-luciferase reporter gene assay. Compared with healthy volunteers, miR-885-3p expression in acute asthma patients’ plasma was significantly downregulated. In 16HBE cells, the stimulation of LPS reduced miR-885-3p expression. MiR-885-3p overexpression reduced LPS-stimulated 16HBE cell injury by enhancing cell viability, and suppressing the levels of inflammatory factors and apoptosis. Furthermore, TLR4 was identified as miR-885-3p’s target gene. TLR4 overexpression weakened the impacts of miR-885-3p on LPS-stimulated cell injury and NF-κB-MyD88 signaling. In conclusion, miR-885-3p can reduce LPS-induced 16HBE cell damage, via targeting TLR4 to suppress the NF-κB-MyD88 pathway.

MicroRNA-15b-5p inhibits tumor necrosis factor alpha-induced proliferation, migration, and extracellular matrix production of airway smooth muscle cells via targeting yes-associated protein 1

The excessive proliferation and the deposition of extracellular matrix (ECM) of airway smooth muscle (ASM) cells facilitates airway remodeling in asthma. This study explores how microRNA-15b-5p (miR-15b-5p) functions in modulating the proliferation, migration, inflammatory response, and ECM deposition of ASM cells. MiR-15b-5p and yes-associated protein 1 (YAP1) mRNA expression levels in tumor necrosis factor alpha (TNF-α)-induced ASM cells were, respectively, examined by real-time quantitative polymerase-chain reaction. Besides, the proliferative ability and migrative potential of ASM cells were examined by cell counting kit-8 assay, 5-bromo-2 ‘-deoxyuridine assay, and transwell assays, respectively. Interleukin-6 and interleukin-8 levels in ASM cells were detected by enzyme-linked immunosorbent assay. YAP1, collagen I, and collagen III expressions in ASM cells were detected by Western blot. With dual-luciferase reporter gene assay, the relations between miR-15b-5p and YAP1 3ʹUTR in ASM cells was examined. MiR-15b-5p expression level was reduced in ASM cells treated with TNF-α. MiR-15b-5p repressed TNF-α-initiated growth and migration of ASM cells and also suppressed IL-6 and IL-8 secretion, and inhibited collagen I and collagen III expressions in ASM cells. Furthermore, it was validated that YAP1 was a downstream target of miR-15b-5p in ASM cells. Notably, YAP1 overexpression attenuated the inhibitory effects of miR-15b-5p up-regulation on the proliferation, migration, and inflammatory response, as well as ECM deposition of TNF-α-induced ASM cells. In conclusion, miR-15b-5p/YAP1 axis modulates the growth, migration, inflammatory response, and ECM deposition of ASM cells, thus participating in the pathogenesis of asthma.

Multiplex-Heterogeneous Network-Based Capturing Potential SNP "Switches" of Pathways Associating With Diverse Disease Characteristics of Asthma

Asthma is a complex heterogeneous respiratory disorder. In recent years nubbly regions of the role of genetic variants and transcriptome including mRNAs, microRNAs, and long non-coding RNAs in the pathogenesis of asthma have been separately excavated and reported. However, how to systematically integrate and decode this scattered information remains unclear. Further exploration would improve understanding of the internal communication of asthma. To excavate new insights into the pathogenesis of asthma, we ascertained three asthma characteristics according to reviews, airway inflammation, airway hyperresponsiveness, and airway remodeling. We manually created a contemporary catalog of corresponding risk transcriptome, including mRNAs, miRNAs, and lncRNAs. MIMP is a multiplex-heterogeneous networks-based approach, measuring the relevance of disease characteristics to the pathway by examining the similarity between the determined vectors of risk transcriptome and pathways in the same low-dimensional vector space. It was developed to enable a more concentrated and in-depth exploration of potential pathways. We integrated experimentally validated competing endogenous RNA regulatory information and the SNPs with significant pathways into the ceRNA-mediated SNP switching pathway network (CSSPN) to analyze ceRNA regulation of pathways and the role of SNP in these dysfunctions. We discovered 11 crucial ceRNA regulations concerning asthma disease feature pathway and propose a potential mechanism of ceRNA regulatory SNP → gene → pathway → disease feature effecting asthma pathogenesis, especially for MALAT1 (rs765499057/rs764699354/rs189435941) → hsa-miR-155 → IL13 (rs201185816/rs1000978586/rs202101165) → Interleukin-4 and Interleukin-13 signaling → inflammation/airway remodeling and MALAT1 (rs765499057/rs764699354/rs189435941) → hsa-miR-155 → IL17RB (rs948046241) → Interleukin-17 signaling (airway remodeling)/Cytokine-cytokine receptor interaction (inflammation). This study showed a systematic and propagable workflow for capturing the potential SNP “switch” of asthma through text and database mining and provides further information on the pathogenesis of asthma.

Hypoxia-inducible factor-1α promotes proliferation of airway smooth muscle cells through miRNA-103-mediated signaling pathway under hypoxia

The hypoxia-inducible factor-1α (HIF-1α) activated during asthma development plays a causative role in the abnormal proliferation of airway smooth muscle (ASM) cells and consequential airway remodeling. Although the underlying mechanisms of HIF-1α activity have not been fully revealed, HIF-1α-regulated miRNA signaling is considered important for disrupted differentiation and proliferation of local cells in various tissues under inflammation. We aimed to identify the key miRNA signaling involved in HIF-1α regulation of the proliferation of ASM cells. This study was based on primary ASM cells isolated from adult male rats. Three percent O2 and 21% O2 were set as hypoxic and normoxic condition for ASM cell treatment, respectively. Knockdown of HIF-1α was performed through transfection of pSUPER-shHIF-1α plasmid. Overexpression and knockdown of miRNA-103 were performed through transfection of miRNA-103 mimic or inhibitor, respectively. Levels of HIF-1α, PTEN, and PCNA were determined with Western blot and RT-qPCR. Hypoxia increased HIF-1α and miRNA-103 expression and proliferation in ASM cells. Knockdown of HIF-1α suppressed hypoxia-induced upregulation of proliferation and miRNA-103 expression in ASM cells. Knockdown of miRNA-103 displayed similar effects as knockdown of HIF-1α in ASM cells under hypoxia, while overexpression of miRNA-103 played the opposite role. Additionally, increased or decreased expression of PTEN was also detected when HIF-1α/miRNA-103 was knocked down under hypoxia or miRNA-103 was overexpressed under normoxia, respectively. Our results suggest that HIF-1α promotes the proliferation of ASM cells via upregulating miRNA-103 expression under hypoxia, and PTEN is involved in the miRNA-103-mediated signaling pathway.

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.

NR4A3: A Key Nuclear Receptor in Vascular Biology, Cardiovascular Remodeling, and Beyond

The mechanisms committed in the activation and response of vascular and inflammatory immune cells play a major role in tissue remodeling in cardiovascular diseases (CVDs) such as atherosclerosis, pulmonary arterial hypertension, and abdominal aortic aneurysm. Cardiovascular remodeling entails interrelated cellular processes (proliferation, survival/apoptosis, inflammation, extracellular matrix (ECM) synthesis/degradation, redox homeostasis, etc.) coordinately regulated by a reduced number of transcription factors. Nuclear receptors of the subfamily 4 group A (NR4A) have recently emerged as key master genes in multiple cellular processes and vital functions of different organs, and have been involved in a variety of high-incidence human pathologies including atherosclerosis and other CVDs. This paper reviews the major findings involving NR4A3 (Neuron-derived Orphan Receptor 1, NOR-1) in the cardiovascular remodeling operating in these diseases.

PADI6 Regulates Trophoblast Cell Migration-Invasion Through the Hippo/YAP1 Pathway in Hydatidiform Moles

Purpose

Peptidyl arginine deiminase, type VI (PADI6), a member of the subcortical maternal complex, plays an important role in oocyte growth and the development of fertilized oocytes. Human patients with PADI6 mutations can suffer from multiple reproductive deficiencies including hydatidiform moles and miscarriages. Recent studies have demonstrated that the Hippo signaling pathway plays a central role in the specification of the first cell fates and the maintenance of the human placental trophoblast epithelium. The present study aimed to verify the hypothesis that PADI6 regulates the biological functions of trophoblast cells by targeting YAP1 and to explore the mechanism by which PADI6 accomplishes this in trophoblast cells.

Methods

Villi from HMs and human trophoblast cell lines were used to identify the localization of PADI6 and YAP1 by immunohistochemistry and immunocytochemistry. PADI6 overexpression and knockdown were induced in human trophoblast cells. Co-immunoprecipitation was used to explore the interaction between PADI6 and YAP1. Wound healing, Transwell and EdU staining assays were used to detect migration, invasion and proliferation. Flow cytometric analysis was used to analyze the cell cycle and apoptosis. β-Tubulin and F-actin levels were determined by Western blot, quantitative real-time PCR and phalloidin staining.

Results

The results showed that PADI6 and YAP1 had the same expression pattern in villi and colocalized in the cytotrophoblast. An interaction between PADI6 and YAP1 was also confirmed in human trophoblast cell lines. We found that PADI6 positively regulated the expression of YAP1. Functionally, overexpression of PADI6 promoted cell cycle progression and enhanced migration, invasion, proliferation and apoptosis, whereas downregulation of PADI6 showed the opposite effects.

Conclusion

This study demonstrates that YAP1 is a novel target of PADI6 that serves as an important regulator of trophoblast dysfunction. The crosstalk between the Hippo/YAP1 pathway and the SCMC might be a new topic to explore to uncover the pathological mechanisms of HMs.

MicroRNA-30b-5p promotes the proliferation and migration of human airway smooth muscle cells induced by platelet-derived growth factor by targeting phosphatase and tensin homolog deleted on chromosome ten

Dysfunction of airway smooth muscle (ASM) cells is crucial in asthma pathogenesis. Here, microRNA-30b-5p (miR-30b-5p)’s function and mechanism in ASM cells’ multiplication and migration were investigated. Microarray was utilized for identifying the differentially expressed miRNAs in the bronchial epithelial cells of the asthma patients and healthy controls. Platelet-derived growth factor (PDGF) was employed to treat ASM cells to establish an in-vitro asthma model. Quantitative real-time PCR (qRT-PCR) was conducted for detecting the expressions of miR-30b-5p and phosphatase and tensin homolog deleted on chromosome 10 (PTEN). 3-(4,5-Dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) and 5-bromo-2ʹ-deoxyuridine (BrdU) assays were used for examining cell multiplication; Transwell assay was performed for detecting cell migration; cell cycle was analyzed through flow cytometry. The targeted relationship between PTEN and miR-30b-5p was verified using a dual-luciferase reporter gene assay. Western blot was used for detecting the expressions of phosphorylated (p)-phosphatidylinositol 3-kinase (PI3K), PTEN, PI3K, protein kinase B (AKT) and p-AKT in ASM cells. We demonstrated that, miR-30b-5p expression in the bronchial epithelial cells of asthmatic patients was up-regulated. It was also increased in PDGF-stimulated ASM cells. Transfection of miR-30b-5p mimics facilitated ASM cells’ multiplication, migration and cycle progression, while inhibiting miR-30b-5p had the opposite effect. Furthermore, miR-30b-5p could target PTEN to repress PTEN expression. PTEN overexpression attenuated the effect of miR-30b-5p on ASM cells. Moreover, miR-30b-5p overexpression facilitated the expression of p-PI3K and p-AKT in PDGF-stimulated ASM cells. Collectively, miR-30b-5p activates the PI3K/AKT pathway by targeting PTEN to facilitate PDGF-induced dysfunction of ASM cells.

The lncRNA PVT1/miR-590-5p/FSTL1 axis modulates the proliferation and migration of airway smooth muscle cells in asthma

OBJECTIVE

Asthma is a prevalent chronic inflammatory airway disease that is characterised by airway remodelling and airway hyperresponsiveness. Abnormal proliferation and migration of airway smooth muscle cells (ASMCs) contribute to airway remodelling in asthma. However, the molecular mechanism underlying an increased ASMC mass in asthma remains elusive. Herein, we aimed at investigating the regulation of lncRNA PVT1 on ASMCs and focussing on the mechanism in the proliferation and migration.

METHODS

Expression levels of lncRNA PVT1 and miR-590-5p in the serum collected from 24 children with asthma and 10 control children were determined by qRT-PCR. ASMCs proliferation and migration prior to and post platelet-derived growth factor subunit B (PDGF-BB) stimulation were examined by CCK-8 test and transwell assay. Dual-luciferase reporter assay was performed to determine miR-590-5p interaction with lncRNA PVT1 and follistatin-like 1 (FSTL1). Expression of lncRNA PVT1, miR-590-5p, FSTL1, C-Myc, cyclin D1, and cyclin-dependent kinase 1 (CDK1) was tested by quantitative real-time PCR (qRT-PCR) and immunoblotting analysis.

RESULTS

The expression level of lncRNA PVT1 was higher but the expression level of miR-590-5p was lower in the serum of children with asthma than in control children. The expression level of lncRNA PVT1 was negatively correlated with the expression level of miR-590-5p in asthma. LncRNA PVT1 was upregulated upon PDGF-BB stimulation. LncRNA PVT1 knockdown by its specific shRNA repressed PDGF-BB-induced promotion of proliferation and migration in ASMCs and triggered an elevated miR-590-5p along with declined C-Myc, cyclin D1, and CDK1. The effects of lncRNA PVT1 knockdown on PDGF-BB-induced ASMCs were lost upon miR-590-5p inhibition. MiR-590-5p targeted FSTL1 gene and declined its expression, thus suppressing ASMC proliferation and migration following PDGF-BB stimulation and downregulating C-Myc, cyclin D1, and CDK1 expressions. The effects of miR-590-5p on PDGF-BB-induced ASMCs were lost upon FSTL1 overexpression.

CONCLUSION

These results support the notion that the lncRNA PVT1/miR-590-5p/FSTL1 axis modulates ASMCs proliferation and migration following PDGF-BB stimulation, providing a potential therapeutic target to attenuate airway remodelling in asthma.

Baicalin regulates the development of pediatric asthma via upregulating microRNA-103 and mediating the TLR4/NF-κB pathway

Pediatric asthma seriously endangers the well-being and health of children worldwide. Baicalin (BA) protects against diverse disorders, including asthma. Therefore, this study explored the mechanism of BA in pediatric asthma. The ovalbumin (OVA)-induced asthmatic mouse model was established to evaluate BA efficacy from aspects of oxidative stress, inflammation, blood cells in bronchoalveolar lavage fluid (BALF) and collagen deposition. Differentially expressed microRNAs (miRs) in BA-treated mice were analyzed. Effects of BA on PDGF-BB-induced smooth muscle cells (SMCs) were assessed. miR downstream mRNA and the related pathway were predicted and verified, and their effects on asthmatic mice were evaluated. BA effectively reversed OVA-induced oxidative stress and inflammation, as well as decreased the number of total cells, eosinophils and neutrophils in BALF, and collagen deposition. miR-103 was significantly upregulated after BA treatment. BA inhibited the abnormal proliferation of PDGF-BB-induced SMCs, which was prevented by miR-103 knockdown. miR-103 targeted TLR4 and regulated the extent of NF-κB phosphorylation. In vivo, miR-103 inhibition weakened the alleviating effects of BA on asthma, which was then reversed after silencing of TLR4. We highlighted that BA has the potency to halt the pediatric asthma progression via miR-103 upregulation and the TLR4/NF-κB axis inhibition.

MicroRNAs as Potential Regulators of Immune Response Networks in Asthma and Chronic Obstructive Pulmonary Disease

Chronic respiratory diseases (CRDs) are an important factor of morbidity and mortality, accounting for approximately 6% of total deaths worldwide. The main CRDs are asthma and chronic obstructive pulmonary disease (COPD). These complex diseases have different triggers including allergens, pollutants, tobacco smoke, and other risk factors. It is important to highlight that although CRDs are incurable, various forms of treatment improve shortness of breath and quality of life. The search for tools that can ensure accurate diagnosis and treatment is crucial. MicroRNAs (miRNAs) are small non-coding RNAs and have been described as promising diagnostic and therapeutic biomarkers for CRDs. They are implicated in multiple processes of asthma and COPD, regulating pathways associated with inflammation, thereby showing that miRNAs are critical regulators of the immune response. Indeed, miRNAs have been found to be deregulated in several biofluids (sputum, bronchoalveolar lavage, and serum) and in both structural lung and immune cells of patients in comparison to healthy subjects, showing their potential role as biomarkers. Also, miRNAs play a part in the development or termination of histopathological changes and comorbidities, revealing the complexity of miRNA regulation and opening up new treatment possibilities. Finally, miRNAs have been proposed as prognostic tools in response to both conventional and biologic treatments for asthma or COPD, and miRNA-based treatment has emerged as a potential approach for clinical intervention in these respiratory diseases; however, this field is still in development. The present review applies a systems biology approach to the understanding of miRNA regulatory networks in asthma and COPD, summarizing their roles in pathophysiology, diagnosis, and treatment.

Eosinophil microRNAs Play a Regulatory Role in Allergic Diseases Included in the Atopic March

(1) Background: The atopic march is defined by the increased prevalence of allergic diseases after atopic dermatitis onset. In fact, atopic dermatitis is believed to play an important role in allergen sensitization via the damaged skin barrier, leading to allergic diseases such as allergic asthma and allergic rhinitis. The eosinophil, a pro-inflammatory cell that contributes to epithelial damage, is one of the various cells recruited in the inflammatory reactions characterizing these diseases. Few studies were conducted on the transcriptome of this cell type and even less on their specific microRNA (miRNA) profile, which could modulate pathogenesis of allergic diseases and clinical manifestations post-transcriptionally. Actually, their implication in allergic diseases is not fully understood, but they are believed to play a role in inflammation-related patterns and epithelial cell proliferation. (2) Methods: Next-generation sequencing was performed on RNA samples from eosinophils of individuals with atopic dermatitis, atopy, allergic rhinitis and asthma to obtain differential counts of primary miRNA (pri-miRNA); these were also analyzed for asthma-related phenotypes such as forced expiratory volume in one second (FEV₁), immunoglobulin E (IgE) and provocative concentration of methacholine inducing a 20% fall in forced expiratory volume in 1 s (PC₂₀) levels, as well as FEV₁ to forced vital capacity (FEV₁/FVC) ratio. (3) Results: Eighteen miRNAs from eosinophils were identified to be significantly different between affected individuals and unaffected ones. Based on counts from these miRNAs, individuals were then clustered into groups using Ward's method on Euclidian distances. Groups were found to be explained by asthma diagnosis, familial history of respiratory diseases and allergic rhinitis as well as neutrophil counts. (4) Conclusions: The 18 differential miRNA counts for the studying phenotypes allow a better understanding of the epigenetic mechanisms underlying the development of the allergic diseases included in the atopic march.

Therapeutic RNA Strategies for Chronic Obstructive Pulmonary Disease

Chronic obstructive pulmonary disease (COPD) is characterized by airflow limitation with persistent respiratory symptoms. Current therapeutics for COPD are largely borrowed from the drug armamentarium for the treatment of asthma, which has different pathophysiological mechanisms from COPD. COPD has been linked to dysregulated expression of mRNAs and noncoding (nc)RNAs including miRNAs, PIWI-interacting (pi)RNAs, long noncoding (lnc)RNAs, and circular (circ)RNAs. This review highlights and discusses some recent advances towards development of RNA therapeutics for COPD.

miR‑106b‑5p modulates acute pulmonary embolism via NOR1 in pulmonary artery smooth muscle cells

Acute pulmonary embolism (APE) is a common cause of acute cardiovascular failure and has a high morbidity and mortality rate. Inhibiting the excessive proliferation and migration of pulmonary artery smooth muscle cells (PASMCs) is a potential treatment strategy following an APE. Various microRNAs (miRNAs/miRs) have been shown to regulate cell proliferation, apoptosis and other physiological processes. However, the specific mechanisms underlying the action of multiple miRNAs are still not understood in APE. In the present study, the role of miR‑106b‑5p on APE was demonstrated in platelet‑derived growth factor (PDGF)‑induced PASMCs in vitro and in an APE‑mouse model in vivo. The results showed that miR‑106b‑5p expression was downregulated in PDGF‑induced PASMCs and APE mice, and NOR1 levels were upregulated. Proliferating cell nuclear antigen (PCNA) expression levels in cells and proliferation of PASMCs proliferation and migration were reduced following treatment with miR‑106b‑5p agomiR, and increased following treatment with miR‑106b‑5p antagomiR. miR‑106b‑5p targeted the 3' untranslated region of NOR‑1 mRNA and reduced NOR1 expression. NOR1 overexpression reversed the effects of miR‑106‑5p on PDGF‑induced PASMCs. The functional roles of miR‑106b‑5p in PDGF‑induced PASMCs and an APE mouse‑model, and the underlying molecular mechanisms were evaluated. AgomiR‑106b‑5p improved APE‑induced mortality and pulmonary vascular proliferation in mice. These data suggest that miR‑106‑5p is a novel regulator of proliferation of PASMCs and of pulmonary vascular remodeling through PDGF‑induced PASMCs in an APE mouse model via targeting NOR1. These results expand the understanding of the pathogenesis underlying APE and highlight potential novel therapeutic targets.

Resveratrol prevented experimental pulmonary vascular remodeling via miR-638 regulating NR4A3/cyclin D1 pathway

OBJECTIVE

Resveratrol has shown benefit for pulmonary hypertension improvement. Our previous reports showed NR4A3/cyclin D1 pathway promoted pulmonary arterial smooth muscle cells (PASMCs) proliferation. This study tried to explore the mechanism underlying this process, focusing on the role of resveratrol in regulation of miRNA and NR4A3.

METHODS

Rats were injected with monocrotaline (MCT) to establish pulmonary hypertension (PH) models. Resveratrol was used to prevent pulmonary vascular remodeling. Primary rat PASMCs were cultured in vitro and stimulated by platelet-derived growth factor (PDGF) with or without resveratrol. Cells proliferation and expression of miR-638 as well as NR4A3 were evaluated.

RESULTS

MCT resulted in significant pulmonary vascular remodeling and down-regulation of miR-638, which could be suppressed by resveratrol. Moreover, PDGF-induced PASMC proliferation and miR-638 down-regulation were both significantly prevented by resveratrol treatment in vitro. MiR-638 mimics markedly inhibited PASMC proliferation and percentage of PCNA-positive cells in vitro. But anti-miR-638 could markedly promote cells proliferation and percentage of PCNA-positive cells. The luciferase reporter assay showed that NR4A3 was a direct target of miR-638. The loss-of-function and gain-of-function experiments indicated that NR4A3 promoted proliferation via cyclin D1 pathway.

CONCLUSION

Our data indicated that resveratrol prevented MCT-induced pulmonary vascular remodeling via miR-638 regulating NR4A3/cyclin D1 pathway.

Skeletal muscle transcriptional networks linked to type I myofiber grouping in Parkinson's disease

Parkinson's disease (PD) is a common neurodegenerative disorder impacting cognition, movement, and quality of life in >10 million individuals worldwide. We recently characterized and quantified a skeletal muscle pathology in PD represented by exaggerated type I myofiber grouping presumed to result from denervation-reinnervation processes. Our previous findings indicated that impaired neuromuscular junction integrity may be involved in type I grouping, which is associated with excessive motor unit activation during weight-bearing tasks. In this study, we performed transcriptional profiling to test the hypothesis that type I grouping severity would link to distinct gene expression networks. We generated transcriptome-wide poly(A) RNA-Seq data from skeletal muscle of individuals with PD [n = 12 (9 men, 3 women); 67 ± 2 yr], age- and sex-matched older adults (n = 12; 68 ± 2 yr), and sex-matched young adults (n = 12; 30 ± 1 yr). Differentially expressed genes were evaluated across cohorts. Weighted gene correlation network analysis (WGCNA) was performed to identify gene networks most correlated with indicators of abnormal type I grouping. Among coexpression networks mapping to phenotypes pathologically increased in PD muscle, one network was highly significantly correlated to type I myofiber group size and another to percentage of type I myofibers found in groups. Annotation of coexpressed networks revealed that type I grouping is associated with altered expression of genes involved in neural development, postsynaptic signaling, cell cycle regulation and cell survival, protein and energy metabolism, inflammation/immunity, and posttranscriptional regulation (microRNAs). These transcriptomic findings suggest that skeletal muscle may play an active role in signaling to promote myofiber survival, reinnervation, and remodeling, perhaps to an extreme in PD.NEW & NOTEWORTHY Despite our awareness of the impact of Parkinson's disease (PD) on motor function for over two centuries, limited attention has focused on skeletal muscle. We previously identified type I myofiber grouping, a novel indicator of muscle dysfunction in PD, presumably a result of heightened rates of denervation/reinnervation. Using transcriptional profiling to identify networks associated with this phenotype, we provide insight into potential mechanistic roles of skeletal muscle in signaling to promote its survival in PD.

Production of bioactive recombinant human myeloid-derived growth factor in Escherichia coli and its mechanism on vascular endothelial cell proliferation

Myeloid-derived growth factor (MYDGF) is a novel protein secreted by bone marrow cells that features important physiological functions. In recent years, MYDGF has gained considerable interest due to their extensive beneficial effect on cardiac repair and protects cardiomyocytes from cell death. However, its precise molecular mechanisms have not been well elucidated. The purpose of this study was to produce sufficient amount of biologically active recombinant human (rh) MYDGF more economically and effectively by using in vitro molecular cloning techniques to study its clinical application. The prokaryotic expression system of Escherichia coli was established for the preparation of rhMYDGF. Finally, a large amount of high biologically active and purified form of recombinant protein was obtained. Moreover, we investigated the potential mechanism of rhMYDGF-mediated proliferation and survival in human coronary artery endothelial cells (HCAECs). Mechanistically, the results suggested that MAPK/STAT3 and the cyclin D1 signalling pathways are indispensable for rhMYDGF-mediated HCAEC proliferation and survival. Therefore, this study successfully established a preparation protocol for biologically active rhMYDGF and it may be a most economical way to produce high-quality active rhMYDGF for future clinical application.

Crosstalk Between Signaling Pathways Involved in the Regulation of Airway Smooth Muscle Cell Hyperplasia

Increased ASM mass, primarily due to ASM hyperplasia, has been recognized as a hallmark of airway remodeling in asthma. Increased ASM mass is the major contributor to the airway narrowing, thus worsening the bronchoconstriction in response to stimuli. Inflammatory mediators and growth factors released during inflammation induce increased ASM mass surrounding airway wall via increased ASM proliferation, diminished ASM apoptosis and increased ASM migration. Several major pathways, such as MAPKs, PI3K/AKT, JAK2/STAT3 and Rho kinase, have been reported to regulate these cellular activities in ASM and were reported to be interrelated at certain points. This article aims to provide an overview of the signaling pathways/molecules involved in ASM hyperplasia as well as the mapping of the interplay/crosstalk between these major pathways in mediating ASM hyperplasia. A more comprehensive understanding of the complexity of cellular signaling in ASM cells will enable more specific and safer drug development in the control of asthma.

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.