E3 Ubiquitin Ligase NEDD4L Negatively Regulates Skin Tumorigenesis by Inhibiting IL-6/GP130 Signaling Pathway.

IL-6 signaling plays a crucial role in the survival and metastasis of skin cancer. NEDD4L acts as a suppressor of IL-6 signaling by targeting GP130 degradation. However, the effects of the NEDD4L-regulated IL-6/GP130 signaling pathway on skin cancer remain unclear. In this study, protein expression levels of NEDD4L and GP130 were measured in tumor tissues from patients with cutaneous squamous cell carcinoma. Skin tumors were induced in wild-type and Nedd4l-knockout mice, and activation of the IL-6/GP130/signal transducer and activator of transcription 3 signaling pathway was detected. The results indicated a negative correlation between the protein expression levels of NEDD4L and GP130 in cutaneous squamous cell carcinoma tissues from patients. Nedd4l deficiency significantly promoted 7,12-dimethylbenz[a]anthracene/12-O-tetradecanoylphorbol-13-acetate-induced skin tumorigenesis and benign-to-malignant conversion by activating the IL-6/GP130/signal transducer and activator of transcription 3 signaling pathway, which was abrogated by supplementation with the GP130 inhibitor SC144. Furthermore, our findings suggested that NEDD4L can interact with GP130 and promote its ubiquitination in skin tumors. In conclusion, our results indicate that NEDD4L could act as a tumor suppressor in skin cancer, and inhibition of GP130 could be a potential therapeutic method for treating this disease.

Activation of Autophagy Induces Monocrotaline-Induced Pulmonary Arterial Hypertension by FOXM1-Mediated FAK Phosphorylation.

PURPOSE: It has been shown that activation of autophagy promotes the development of pulmonary arterial hypertension (PAH). Meanwhile, forkhead box M1 (FOXM1) has been found to induce autophagy in several types of cancer. However, it is still unclear whether FOXM1 mediates autophagy activation in PAH, and detailed mechanisms responsible for these processes are indefinite. METHOD: PAH was induced by a single intraperitoneal injection of monocrotaline (MCT) to rats. The right ventricle systolic pressure (RVSP), right ventricular hypertrophy index (RVHI), percentage of medial wall thickness (%MT), α-smooth muscle actin (α-SMA) staining, and Ki67 staining were performed to evaluate the development of PAH. The protein levels of FOXM1, phospho-focal adhesion kinase (p-FAK), FAK, and LC3B were determined by immunoblotting or immunohistochemistry. RESULTS: FOXM1 protein level and FAK activity were significantly increased in MCT-induced PAH rats, this was accompanied with the activation of autophagy. Pharmacological inhibition of FOXM1 or FAK suppressed MCT-induced autophagy activation, decreased RVSP, RVHI and %MT in MCT-induced PAH rats, and inhibited the proliferation of pulmonary arterial smooth muscle cells and pulmonary vessel muscularization in MCT-induced PAH rats. CONCLUSION: FOXM1 promotes the development of PAH by inducing FAK phosphorylation and subsequent activation of autophagy in MCT-treated rats.

Ubiquitin-specific protease 7 mediates platelet-derived growth factor-induced pulmonary arterial smooth muscle cells proliferation.

Pulmonary arterial hypertension is a devastating pulmonary vascular disease, in which the pathogenesis is complicated and unclear. Pulmonary arterial smooth muscle cells (PASMCs) proliferation is a key pathological feature of pulmonary arterial hypertension. It has been shown that ubiquitin-specific protease 7 (USP7) is involved in cancer cell proliferation via deubiquitinating and stabilizing E3 ubiquitin ligase mouse double minute 2 (MDM2). However, the effect of USP7 and MDM2 on platelet-derived growth factor (PDGF)-induced PASMCs proliferation is uncertain. This study aims to explore this issue. Our results indicated that PDGF up-regulated USP7 protein expression and stimulated PASMCs proliferation; this was accompanied with the increase of MDM2, forkhead box O4 (FoxO4) reduction and elevation of CyclinD1. While prior transfection of USP7 siRNA blocked PDGF-induced MDM2 up-regulation, FoxO4 down-regulation, increase of CyclinD1 and cell proliferation. Pre-depletion of MDM2 by siRNA transfection reversed PDGF-induced reduction of FoxO4, up-regulation of CyclinD1 and PASMCs proliferation. Furthermore, pre-treatment of cells with proteasome inhibitor MG-132 also abolished PDGF-induced FoxO4 reduction, CyclinD1 elevation and cell proliferation. Our study suggests that USP7 up-regulates MDM2, which facilitates FoxO4 ubiquitinated degradation, and subsequently increases the expression of CyclinD1 to mediate PDGF-induced PASMCs proliferation.

Sphingosine-1-phosphate promotes pulmonary artery smooth muscle cells proliferation by stimulating autophagy-mediated E-cadherin/CDH1 down-regulation.

It has been shown that sphingosine-1-phosphate (S1P) is elevated in patients with pulmonary arterial hypertension (PAH) and promotes the proliferation of pulmonary artery smooth muscle cells (PASMCs). Meanwhile, S1P has been found to induce the activation of autophagy in several types of human diseases including cancers. However, it is still unclear whether activation of autophagy mediates S1P-induced PASMCs proliferation, and detailed mechanisms responsible for these processes are indefinite. The aims of this study are to address these issues. S1P dose- and time-dependently reduced the expression of E-cadherin/CDH1 and stimulated PASMCs proliferation; this was accompanied with the elevation of TNF receptor-associated factor 2 (TRAF2), up-regulation and ubiquitination of BECN1 and the activation of autophagy. Prior silencing TRAF2 or BECN1 using siRNA or pre-incubation of cells with autophagy inhibitor chloroquine phosphate (CQ) suppressed S1P-induced autophagy activation and subsequent CDH1 degradation and further PASMCs proliferation. Taken together, our study indicates that S1P promotes the activation of autophagy by accelerating TRAF2-mediated BECN1 up-regulation and ubiquitination, which in turn results in CDH1 reduction and contributes to PASMCs proliferation.

The association between cystatin C and COPD: a meta-analysis and systematic review.

BACKGROUND: In recent years, many studies have discovered that cystatin C (Cys C) may play an important role in respiratory diseases, especially in chronic obstructive pulmonary disease (COPD). However, the findings of these studies were inconsistent. This systematic review and meta-analysis aimed to assess the relationship between serum Cys C and COPD. METHODS: We conducted a systematic literature search in PubMed, Embase, Web of Science, Wanfang databases, and the China National Knowledge Infrastructure. The standardized mean difference (SMD), Fisher's Z-value and 95% confidence interval (CI) were calculated to investigate the effect sizes. Subgroup analyses were performed on disease status, ethnicity, assay method, and study design. Sensitivity was performed, and publication bias was assessed. RESULTS: A total of 15 studies, including 4079 COPD patients and 5949 controls, were included in this meta-analysis. The results showed that serum Cys C levels in patients with COPD were significantly higher than those in controls (SMD = 0.99, 95% CI =0.62-1.37, P < 0.001), especially in AECOPD (SMD = 1.59, 95% CI =1.05-2.13, P < 0.001), and there were statistically different among AECOPD and SCOPD (SMD = 0.35, 95% CI =0.10-0.59, P = 0.005). The serum Cys C levels were negatively correlated with FEV1%pre (Z = - 0.45, 95%CI = -0.58--0.32, P = 0.011) and FEV1/FVC (Z = - 0.32, 95%CI = -0.50--0.14, P = 0.006). The serum Cys C levels were independent of ethnicity, assay method, and study design. CONCLUSION: Serum Cys C levels were associated with COPD and COPD exacerbation, and they were inversely correlated with FEV1%pre and FEV1/FVC.

Leukotriene B4 induces proliferation of rat pulmonary arterial smooth muscle cells via modulating GSK-3ß/ß-catenin pathway.

Leukotriene B4 (LTB4) has been found to contribute to pulmonary arterial smooth muscle cells (PASMCs) proliferation and pulmonary arterial remodeling therefore the development of pulmonary arterial hypertension (PAH). Yet, the underlying molecular mechanisms remain poorly understood. The present study aims to address this issue. Our results demonstrate that LTB4 dose- and time-dependently induced proliferation of primary cultured rat PASMCs, this was accompanied with the activation of phosphatidylinositol-3-kinase/Akt (PI3K/Akt) and extracellular signal-regulated kinase 1/2 (ERK1/2) signaling pathways, and consequent inactivation of glycogen synthase kinase-3ß (GSK-3ß), up-regulation of ß-catenin and induction of cyclin D1 expression. The presence of PI3K inhibitor (LY294002) or MEK inhibitor (U0126) or prior silencing of ß-catenin with siRNA suppressed LTB4-induced cyclin D1 up-regulation and PASMCs proliferation. In addition, inactivation or lack of GSK-3ß up-regulated ß-catenin and cyclin D1 in PASMCs. Taken together, our study indicates that activation of PI3K/Akt and ERK1/2 pathways mediates LTB4-induced PASMCs proliferation by modulating GSK-3ß/ß-catenin/cyclin D1 axis and suggests that targeting this pathway might have potential value in alleviating vascular remodeling and benefit PAH.

Clinicopathologic Features and Prognostic Implications of Golgi Phosphoprotein 3 in Non-small Cell Lung Cancer: A Meta-analysis.

Background: A number of studies have investigated the role of Golgi phosphoprotein-3 (GOLPH3) in the pathogenesis and progression of non-small cell lung cancer (NSCLC). However, the results of previous studies are heterogeneous and controversial. The aim of this meta-analysis was to clarify its association with the clinicopathological characteristics of patients and evaluate the prognostic significance of GOLPH3 in NSCLC. Methods: A systematic search was conducted through PMC, PubMed, Medline, Web of Science, Chinese National Knowledge Infrastructure and Wanfang database. The odds ratio (OR) and hazard ratio (HR) with 95 % CI were calculated by STATA 12.0. Results: 8 qualified studies with a total of 1001 patients with NSCLC were included. Pooled results showed that GOLPH3 was highly expressed in tumor tissues compared with adjacent lung tissues (OR, 7.55), and overexpression of GOLPH3 was significantly correlated with advanced clinical stage (OR, 3.42), poor differentiation of tumor (OR, 1.97) and positive lymph node metastasis (OR, 2.58), but no association with histological type, gender, age or tumor size was found in NSCLC patients. In addition, the pooled HR for overall survival was 1.79 by univariate analysis and 1.91 by multivariate analysis. The pooled HR for progression-free survival was 2.50. Conclusions: GOLPH3 could be a risk factor for progression of NSCLC and might act as a potential prognostic biomarker for NSCLC patients.

Clinicopathological and prognostic value of LINC01296 in cancers: a meta-analysis.

Objective: The long intergenic non-coding RNA 01296 (LINC01296) has been reported to be overexpressed in multiple tumours. However, the role of LINC01296 in clinicopathologic and prognostic value in cancers remains completely unknown. The aim of the present meta-analysis was to comprehensively elucidate the correlation between LINC01296 with clinicopathological features and survival outcomes in tumours. Methods: Electronic databases of PubMed, Web of Science, Chinese National Knowledge Infrastructure (CNKI), and Wanfang Database were used to search relevant studies. The role of LINC01296 in cancers was evaluated by pooled hazard ratios (HRs), odds ratios (ORs) and 95% confidence intervals (CIs). Results: In total, nine studies compromising 720 participants were enrolled in this analysis. The pooled results showed increased LINC01296 expression could predict unfavourable overall survival (OS) (HR = 1.89, 95%CI = 1.47-2.43, p < .001). Additionally, elevated LINC01296 expression was correlated with clinical stage (OR = 2.95, 95%CI = 2.13-4.08, p < .001), lymph node metastasis (OR = 2.76, 95%CI = 2.00-3.81, p < .001), tumour size (OR = 2.80, 95%CI = 1.77-4.41, p < .001), and tumour differentiation (OR = 2.11, 95%CI = 1.36-3.27, p < .001) in patients with cancers. Conclusion: The results of this meta-analysis indicated LINC01296 was a novel biomarker for prognosis and clinicopathological parameters in cancers.

Paclitaxel alleviates monocrotaline-induced pulmonary arterial hypertension via inhibition of FoxO1-mediated autophagy.

It has been demonstrated that activation of autophagy is involved in the development of pulmonary arterial hypertension (PAH). Recent studies have shown that cytosolic forkhead box protein O1 (FoxO1) activates autophagy in cancer cells. Paclitaxel has been found to potentially reverse PAH progression. However, the role of FoxO1 and the effects of paclitaxel on autophagy in the pathogenesis of PAH remain unknown. PAH was generated by intraperitoneal injection of monocrotaline (MCT) to rats. The right ventricular systolic pressure (RVSP), the right ventricle hypertrophy index (RV/LV+S), and the percentage of medial wall thickness (%MT) were used to detect the development of PAH. Hematoxylin and eosin staining was performed to measure pulmonary vascular remodeling. The protein level, phosphorylation, and nucleus translocation of FoxO1 and the levels of LC3A, LC3B, and Beclin-1 were examined by immunoblotting. The results showed that in spite of reduced expression of FoxO1, elevated phosphorylation of FoxO1 caused most of FoxO1 accumulating in cytosolic fraction in MCT-PAH rats. Autophagy was also activated in the MCT-PAH group. In cultured rat pulmonary arterial smooth muscle cells (PASMCs), knockdown of FoxO1 markedly blocked autophagy activation, indicating that elevation of cytosolic FoxO1 stimulates autophagy activation. Treatment of PAH rats with paclitaxel reduced FoxO1 phosphorylation and increased FoxO1 nuclear accumulation, despite increased FoxO1 expression, therefore suppressed autophagy, finally reduced elevated RVSP, RV/LV+S, and %MT in MCT-induced PAH. Taken together, paclitaxel inhibits pulmonary vascular remodeling by FoxO1-mediated autophagy suppression, suggesting that paclitaxel might be a novel therapeutic agent for the prevention and treatment of PAH.

Salvianolic acid B inhibits the development of diabetic peripheral neuropathy by suppressing autophagy and apoptosis.

OBJECTIVES: The aim of this study was to evaluate the neuroprotective effects of SalB on high glucose (HG)-induced excessive autophagy and apoptosis in vitro. METHODS: The proliferation and apoptosis of RSC96 cells were determined using the MTT assay and flow cytometry, respectively. Western blot analysis was performed to examine the expression of autophagy and apoptosis-related proteins. RT-PCR and flow cytometry were manipulated to examine the level of Bcl-2. The signals of autophagy markers were detected using immunofluorescence methods. KEY FINDINGS: We found that HG significantly reduced RSC96 cell's proliferation and induced apoptosis. What's more, HG increased the level of autophagy and apoptosis-related proteins. However, these effects were reversed by SalB. In addition, we also found that 3-MA decreased the expression of LC3A/B and Beclin1, while the JNK inhibitor SP600125 reduced the levels of phosphorylated JNK, LC3A/B and Beclin1. CONCLUSIONS: High glucose not only induced apoptosis but also caused autophagic cell death by activating the JNK pathway. These effects prevented by SalB in an opposite manner.

COP9 signalosome subunit 6 mediates PDGF -induced pulmonary arterial smooth muscle cells proliferation.

Up-regulation of mammalian COP9 signalosome subunit 6 (CSN6) and consequent reduction of SCF ubiquitin ligase substrate receptor ß-transduction repeat-containing protein (ß-TrCP) have been shown to be associated with cancer cells proliferation. However, it is unclear whether CSN6 and ß-TrCP are also involved in PDGF-induced pulmonary arterial smooth muscle cells (PASMCs) proliferation. This study aims to address this issue and further explore its potential mechanisms. Our results indicated that PDGF phosphorylated Akt, stimulated PASMCs proliferation; while inhibition of PDGF receptor (PDGFR) by imatinib prevented these effects. PDGF further up-regulated CSN6 protein expression, this was accompanied with ß-TrCP reduction and increase of Cdc25A. Inhibition of PDGFR/PI3K/Akt signaling pathway reversed PDGF-induced such changes and cell proliferation. Prior transfection of CSN6 siRNA blocked PDGF-induced ß-TrCP down-regulation, Cdc25A up-regulation and cell proliferation. Furthermore, pre-treatment of cells with MG-132 also abolished PDGF-induced ß-TrCP reduction, Cdc25A elevation and cell proliferation. In addition, pre-depletion of Cdc25A by siRNA transfection suppressed PDGF-induced PASMCs proliferation. Taken together, our study indicates that up-regulation of CSN6 by PDGFR/PI3K/Akt signaling pathway decreases ß-TrCP by increasing its ubiquitinated degradation, and thereby increases the expression of Cdc25A, which promotes PDGF-induced PASMCs proliferation.

Activation of peroxisome proliferation-activated receptor-γ inhibits transforming growth factor-ß1-induced airway smooth muscle cell proliferation by suppressing Smad-miR-21 signaling.

The aims of the current study were to examine the signaling mechanisms for transforming growth factor-ß1 (TGF-ß1)-induced rat airway smooth muscle cell (ASMC) proliferation and to determine the effect of activation of peroxisome proliferation-activated receptor-γ (PPAR-γ) on TGF-ß1-induced rat ASMC proliferation and its underlying mechanisms. TGF-ß1 upregulated microRNA 21 (miR-21) expression by activating Smad2/3, and this in turn downregulated forkhead box O1 (FOXO1) mRNA expression. In addition, TGF-ß1-Smad-miR-21 signaling also downregulated phosphatase and tensin homolog deleted on chromosome ten (PTEN) expression and thus de-repressed the PI3K-Akt pathway. Depletion of PTEN reduced the nuclear FOXO1 protein level without affecting its mRNA level. Inhibition of the PI3K-Akt pathway or proteasome function reversed PTEN knockdown-induced nuclear FOXO1 protein reduction. Our study further showed that loss of FOXO1 increased cyclin D1 expression, leading to rat ASMC proliferation. Preincubation of rat ASMCs with pioglitazone, a PPAR-γ activator, blocked TGF-ß1-induced activation of Smad2/3 and its downstream targets changes of miR-21, PTEN, Akt, FOXO1, and cyclin D1, resulting in the inhibition of rat ASMC proliferation. Our study suggests that the activation of PPAR-γ inhibits rat ASMC proliferation by suppressing Smad-miR-21 signaling and therefore has a potential value in the prevention and treatment of asthma by negatively modulating airway remodeling.

Clinicopathological and prognostic significance of leucine-rich repeats and immunoglobulin-like domains protein 1 (LRIG1) in malignant tumors: A meta-analysis.

Background: Accumulating studies have demonstrated that the expression of leucine-rich repeats and immunoglobulin-like domains protein1 (LRIG1) is associated with various types of tumors. However, the conclusions of previous studies are not completely consistent. Thus, we conducted this meta-analysis to further explore the authentic value of LRIG1 in cancer outcome and clinical significance. Methods: We systematically searched electronic databases including PubMed, Web of Science, Embase, Chinese National Knowledge Infrastructure and Wanfang database. The hazard ratios (HRs), odds ratio (OR) and 95 % confidence intervals (CI) were calculated for effect measures. Results: 16 qualified studies involving 2043 patients with cancer were enrolled. High LRIG1 expression was associated with a good prognosis in malignant tumors (HR: 0.49, 95% CI=0.39-0.59). Furthermore, positive expression rate of LRIG1 was distinctly lower in cancer tissues than that in normal tissues (OR: 0.09, 95% CI=0.05-0.17). Positive LRIG1 expression was definitely related with smaller tumor size (OR: 1.64, 95% CI=1.11-2.42), early tumor stage (OR: 3.67, 95% CI=1.87-7.21), well degree of differentiation (OR: 4.35, 95% CI=2.12-8.93) and negative recurrence (OR: 0.29, 95% CI=0.16-0.53). Conclusions: LRIG1 expression was associated with a good prognosis in terms of overall survival (OS) and might act as a predictive factor for characteristics of cancer patients.

Activation of AMPK prevents monocrotaline-induced pulmonary arterial hypertension by suppression of NF-κB-mediated autophagy activation.

AIMS: It has been shown that activation of autophagy is involved in the development of pulmonary arterial hypertension (PAH). Meanwhile, activation of nuclear factor-kappaB (NF-κB) has been found to induce autophagy in several types of human diseases including cancer and cardiac diseases. However, it is still unknown whether NF-κB mediates autophagy activation in PAH, and whether activation of adenosine monophosphate-activated protein kinase (AMPK) benefits PAH by modulation of NF-κB and autophagy. MAIN METHODS: Rat models of PAH were established by intraperitoneally injection of monocrotaline (MCT). The right ventricle systolic pressure (RVSP), right ventricular hypertrophy index (RVHI), and percentage of medial wall thickness (%MT) were performed to evaluate the development of PAH. The translocation of NF-κB p65 from cytosol to nucleus, the protein levels of LC3A, LC3B, and RND3 were determined by immunoblotting. Metformin was used to activate AMPK. KEY FINDINGS: NF-κB and autophagy were significantly activated in MCT-induced PAH rats, this was accompanied with the reduction of RND3. Pharmacological inhibition of NF-κB suppressed MCT-induced activation of autophagy and down-regulation of RND3 expression and reduced RVSP, RVHI, and %MT in MCT-induced PAH rats. In addition, activation of AMPK by metformin suppressed NF-κB-mediated autophagy activation and down-regulation of RND3 and therefore reduced RVSP, RVHI, and %MT in MCT-induced PAH. SIGNIFICANCE: NF-κB-induced autophagy activation and consequent down-regulation of RND3 contributes to the development of PAH in MCT-treated rats. Activation of AMPK prevents the development of PAH by targeting on NF-κB to suppress autophagy and vascular remodeling.

Association of Serum Galectin-3 with the Acute Exacerbation of Chronic Obstructive Pulmonary Disease.

BACKGROUND Acute exacerbation of chronic obstructive pulmonary disease (AECOPD) aggravates the overall severity in COPD patients, resulting in severe morbidity and mortality. However, there are no objective biomarkers currently available to predict the development of AECOPD. Several studies have indicated that galectin-3 (Gal-3) is involved in diseases characterized by excessive inflammatory response and fibrosis. The objective of this study was to examine the dynamic changes of Gal-3 in acute exacerbation and convalescence phases of COPD. MATERIAL AND METHODS Serum levels of Gal-3, high sensitivity C-reactive protein (hsCRP), and prohormone of brain natriuretic peptide (pro-BNP) were determined using multiplex enzyme-linked immunosorbent assay kits. Serum levels of Gal-3 in 44 patients with COPD were further analyzed and correlated with the parameters of lung function and the biomarkers of systemic inflammation. RESULTS The mean level of serum Gal-3 was significantly higher in acute exacerbation of COPD compared with the level in COPD convalescence phase (32.10±9.83 versus 29.02±8.68 ng/mL, p<0.01). Serum levels of Gal-3 positively correlated with hsCRP (r=0.354, p=0.018 for total patients) and pro-BNP (r=0.319, p=0.035 for total patients) in AECOPD. In addition, the level of Gal-3 was the highest in the current smoker group, and the lowest in the never-smoker group in either the acute exacerbation phase (33.91±3.55 versus 29.12±11.73 ng/mL, p=0.036) or the convalescence phase (30.94±3.40 versus 27.76±9.68 ng/mL, p=0.045) of COPD. CONCLUSIONS Our results indicated that serum Gal-3 is increased in AECOPD patients, which is also positively associated with systemic inflammation and smoking in patients with COPD, suggesting that Gal-3 might be a valuable biomarker for AECOPD.