MicroRNA-205-5p targets E2F1 to promote autophagy and inhibit pulmonary fibrosis in silicosis through impairing SKP2-mediated Beclin1 ubiquitination.

Silicosis is an occupational disease characterized by extensive pulmonary fibrosis, and the underlying pathological process remains uncertain. Herein, we explored the molecular mechanism by which microRNA-205-5p (miR-205-5p) affects the autophagy of alveolar macrophages (AMs) and pulmonary fibrosis in mice with silicosis through the E2F transcription factor 1 (E2F1)/S-phase kinase-associated protein 2 (SKP2)/Beclin1 axis. Alveolar macrophages (MH-S cells) were exposed to crystalline silica (CS) to develop an in vitro model, and mice were treated with CS to establish an in vivo model. Decreased Beclin1 and increased SKP2 and E2F1 were identified in mice with silicosis. We silenced or overexpressed miR-205-5p, E2F1, SKP2 and Beclin1 to investigate their potential roles in pulmonary fibrosis in vivo and autophagy in vitro. Recombinant adenovirus mRFP-GFP-LC3 was transduced into the MH-S cells to assay autophagic flow. Knocking down Beclin1 promoted pulmonary fibrosis and suppressed the autophagy. Co-immunoprecipitation and ubiquitination assays suggested that SKP2 induced K48-linked ubiquitination of Beclin1. Furthermore, chromatin immunoprecipitation-PCR revealed the site where E2F1 bound to the SKP2 promoter between 1638 bp and 1645 bp. As shown by dual-luciferase reporter gene assay, the transfection with miR-205-5p mimic inhibited the luciferase activity of the wild-type E2F1 3'untranslated region, suggesting that miR-205-5p targeted E2F1. Additionally, miR-205-5p overexpression increased autophagy and reduced the pulmonary fibrosis, while overexpression of E2F1 or SKP2 or inhibition of Beclin1 could annul this effect. The current study elucidated that miR-205-5p targeted E2F1, thereby inhibiting SKP2-mediated Beclin1 ubiquitination to promote macrophage autophagy and inhibit pulmonary fibrosis in mice with silicosis.

TNF-α-TNFR signal pathway inhibits autophagy and promotes apoptosis of alveolar macrophages in coal worker's pneumoconiosis.

OBJECTIVE: Exposure to coal dust causes the development of coal worker's pneumoconiosis (CWP), which is associated with accumulating macrophages in the lower respiratory tract. This study was performed to investigate the effect of tumor necrosis factor-α (TNF-α)-tumor necrosis factor receptor (TNFR) signal pathway on autophagy and apoptosis of alveolar macrophages (AMs) in CWP. METHODS: AMs from controls exposed to coal dust and CWP patients were collected, in which expressions of TNF-α and TNFR1 were determined. Autophagy was observed by transmission electron microscopy, and apoptosis by light microscope and using terminal deoxynucleotidyl transferase dUTP nick-end labeling staining. AMs in CWP patients were treated with TNF-α or anti-TNF-α antibody. Besides, expressions of autophagy marker proteins, apoptosis-related factors, FAS, caspase-8, and receptor-interacting serine-threonine-protein kinase 3 (RIPK3) were determined by western Blot. Activities of caspase-3 and caspase-8 were determined by a fluorescence kit. Flow cytometry was applied to measure the expression of TNFR1 on the surface of the AM. RESULTS: TNF-α expression and TNFR1 expression on the surface of AM, as well as autophagy and apoptotic index were significantly increased in AMs of CWP patients. In response to the treatment of TNF-α, TNF-α expression and TNFR1 expression on the surface of AM as well as LC3I expression were increased, autophagy was decreased, and LC3, LC3II, Beclin1 and B-cell lymphoma 2 expressions decreased, whereas FAS expression and activity and expression of caspase-3 and caspase-8 increased, and apoptotic index increased. Moreover, the situations were reversed with the treatment of anti-TNF-α antibody. CONCLUSION: TNF-α-TNFR signal pathway was involved in the occurrence and development of CWP by activating FAS-caspase-8 and thus inhibiting autophagy while promoting apoptosis of AM.

Analysis of Hemogram of Radiation Workers in Tangshan, China.

OBJECTIVES: This study aimed to investigate changes in peripheral blood cells of radiation workers and explore the impact of long-term ionizing radiation (IR) on human peripheral hemogram. METHODS: With a cohort method, we selected 1,392 radiation workers (case group) and 1,430 non-health-ray-exposure history persons (control group) to detect and analyze their peripheral hemogram. FAITH3000 automatic biochemical analyzer was used for blood testing. Examination of peripheral hemogram includes the examination of white blood cells (WBCs), platelet (PLTs), red blood cells (RBCs), hemoglobin (Hb), lymphocytes (LYMs), and mononuclear cells (MOs). The data analysis was conducted with software SPSS19.0. RESULTS: All the peripheral hemogram indicators (WBCs, RBCs, Hb, PLTs, LYMs, and MOs) in the case group, in accordance with the order of radiology diagnostic medical group, industrial inspection group, petroleum logging group, and radiotherapy medical group, showed a significant decreasing trend and were lower than those in the control group (all P < 0.05). Besides, with the increase of radiation seniority and accumulative radiation dose, all the peripheral hemogram indicators (WBCs, RBCs, Hb, PLTs, LYMs, and MOs) in the case group dramatically decreased and were lower than those in the control group (all P < 0.05). Seniority was in negative association with the expressions of WBCs, PLTs, RBCs, Hb, LYMs, and MOs and radiation dose with Hb, LYMs, and MOs (all P < 0.05). CONCLUSION: Long-term IR has some effects on the health of radiation workers, thus protective measures should be further strengthened.

Circ-E2F3 promotes cervical cancer progression by inhibiting microRNA-296-5p and increasing STAT3 nuclear translocation.

Circular RNA E2F transcription factor 3 (circ-E2F3) has been demonstrated to be differentially expressed in some diseases and cancers. However, the role of circ-E2F3 in cervical cancer (CC) progression remains unclear. Therefore, we aimed to elucidate the mechanism of circ-E2F3 regulation of CC progression. Circ-E2F3 expression was determined in CC samples, and its correlation with the clinicopathological characteristics of CC patients and cell biological processes was examined. The interaction among circ-E2F3, microRNA-296-5p (miR-296-5p), and signal transducer and activator of transcription 3 (STAT3) was analyzed by dual luciferase reporter gene and fluorescence in situ hybridization assays. Circ-E2F3-depleted CaSki cells were implanted into nude mice to verify the function of circ-E2F3 in vivo. Circ-E2F3 was upregulated in both CC tissues and cell lines, and this correlated with the clinicopathological features and poor prognosis of CC patients. Moreover, circ-E2F3 promoted the proliferation, invasion, and migration of CC cells and tumor growth in vivo. It was also observed that circ-E2F3 promoted the nuclear translocation of STAT3 through inhibition of miR-296-5p, thus affecting the expression of cyclin D1. Taken together, the key findings of our study demonstrate that circ-E2F3 induces inhibition of miR-296-5p, which triggers activation and nuclear translocation of STAT3 that then upregulates cyclin D1 expression.

Downregulated miR-129-5p expression inhibits rat pulmonary fibrosis by upregulating STAT1 gene expression in macrophages.

OBJECTIVE: This study investigated the mechanism by which microRNA-129-5p (miR-129-5p) in macrophages affects pulmonary fibrosis in rats by regulating the expression of the signal transducer and activator of transcription 1 (STAT1) gene. METHODS: After the establishment of a pulmonary fibrosis rat model, quantitative real-time polymerase chain reaction (qRT-PCR) was employed to detect the expression of miR-129-5p in the sham group and model group. The binding sites between miR-129-5p and STAT1 were predicted online and verified by using a dual luciferase reporter system. qRT-PCR and Western blot analyses were used to test the effect of miR-129-5p on STAT1 gene expression. M2 macrophages were isolated and induced, and exosomes were extracted. Cell proliferation was detected by EdU. Furthermore, qRT-PCR was performed to detect the expression of STAT1, collagen type I A2 (COL1A2), collagen type III A1 (COL3A1), fibronectin, and α-SMA in cells and tissues followed by the detection of CD9, CD63, CD81, CD31 and STAT1 protein expression using a Western blot analysis. The pulmonary fibrosis area was detected by Masson staining followed by the immunohistochemical detection of α-smooth muscle actin (α-SMA) and type I collagen (COL-I) expression in pulmonary fibroblasts. RESULTS: Compared with the sham group, the expression level of miR-129-5p in the model group was significantly increased (P < 0.05). miR-129-5p was observed to negatively regulate the expression of STAT1 (P < 0.05). The in vitro cell transfection experiments showed that after inhibiting the expression of miR-129-5p, the expression of STAT1 was increased, and the proliferation of fibroblasts and pulmonary fibrosis were inhibited (all P < 0.05). Furthermore, compared with the fibroblasts without coculture, the proliferation of the fibroblasts cocultured with M2 macrophage-secreted exosomes was clearly increased, and the expression levels of COL1A2, COL3A1, fibronectin and α-SMA were significantly increased (all P < 0.05). Compared with the mimic NC-exo group, the miR-129-5p-exo group had significantly increased proliferation of fibroblasts, decreased expression of STAT1, and significantly increased expression of COL1A2, COL3A1, fibronectin and α-SMA, and M2 macrophage-secreted exosomes could carry miR-129-5p to fibroblasts. Furthermore, the in vivo experiment confirmed that the exosomes of M2 macrophages could carry miR-129-5p, which could regulate M2 macrophages with pulmonary fibrosis in vivo. CONCLUSION: M2 macrophages can carry miR-129-5p to pulmonary interstitial fibroblasts and inhibit STAT1 gene expression, which may lead to the proliferation of fibroblasts and promote pulmonary fibrosis. The downregulation of miR-129-5p can significantly promote STAT1 gene expression in macrophages to inhibit pulmonary fibrosis in rats.

Silencing long non-coding RNA MIAT ameliorates myocardial dysfunction induced by myocardial infarction via MIAT/miR-10a-5p/EGR2 axis.

Long non-coding RNA (lncRNA) myocardial infarction-associated transcript (MIAT) has been widely-demonstrated to function as diagnostic markers for acute myocardial infarction (MI). This study was designed to explore the modulatory role of MIAT and its underlying molecular mechanism in MI. Firstly, MI mouse model was developed via ligation of the descending branch of the left coronary artery, and cell model was established through exposure to hypoxic conditions. Online prediction indicated that MIAT could bind to microRNA-10a-5p (miR-10a-5p), while miR-10a-5p was highlighted to bind to early growth response gene-2 (EGR2). MIAT and EGR2 were subsequently determined to be highly-expressed, whereas miR-10a-5p was found to be poorly-expressed in cardiomyocytes exposed to hypoxia as well as in MI mice using RT-qPCR and Western blot assay. The binding relationships between MIAT and miR-10a-5p, and between miR-10a-5p and EGR2 were further confirmed by dual-luciferase reporter and RNA immunoprecipitation assays. The results of in vitro and in vivo experimentation also suggested that overexpression of miR-10a-5p or silencing of MIAT and EGR2 reduced cardiomyocyte apoptosis and increased ATP content, thus alleviating the impairment of cardiac function following MI. In a word, inhibition of MIAT protects against cardiac dysfunction induced by MI through the crosstalk with miR-10a-5p/EGR2.

Up-regulation of microRNA-223 inhibits brain injury and hippocampal neuron apoptosis of rats after febrile seizure through the NLRP3-Caspase-1 signaling pathway.

OBJECTIVE: This study is conducted to explore the role of microRNA-223 (miR-223) in brain injury and apoptosis of hippocampal neurons through the NLRP3-Caspase-1 signaling pathway in febrile seizure (FS) rats. METHODS: The models of FS were induced in rats by hot water-bath, which were stereotactically injected with miR-223 mimics and mimics negative control (NC) to perturb the expression of miR-223. A series of experiments was conducted to find out the potential mechanisms of miR-223 on convulsion attack, learning and memory ability, pathological injury of hippocampal neurons, inflammatory injury, apoptosis of hippocampal neurons in FS rats. Besides, the targeting relationship between miR-223 and NLRP3 was also verified. RESULTS: Low expression of miR-223 was found in hippocampus tissues of FS rats. Up-regulation of miR-223 alleviated convulsion attack and improved learning and memory ability, while inhibiting pathological injury of hippocampal neurons and inflammatory injury in FS rats. Up-regulation of miR-223 promoted the survival of hippocampal neurons and inhibited their apoptosis in FS rats. MiR-223 inhibited the activation of NLRP3-Caspase-1 signaling pathway in hippocampus tissues of FS rats by inhibiting NLRP3. CONCLUSION: The inhibited expression of miR-223 after FS may participate in the activation of the NLRP3-Caspase-1 signaling pathway, resulting in brain injury and apoptosis of hippocampal neurons in rat models of FS.

TNFR/TNF-α signaling pathway regulates apoptosis of alveolar macrophages in coal workers' pneumoconiosis.

We explored the role of TNFR/TNF-α signalingin apoptosis among alveolar macrophages (AM) and its relevance to the development of coal workers' pneumoconiosis (CWP). Purified alveolar macrophages (AMs) were prepared from bronchoalveolar lavage fluid harvested from 366 CWP patients and 120 healthy subjects enrolled inthe study. The purified AMs were then divided into control, SOD, anti-TNFR, TNFR and NFkB inhibitor groups and analyzed for apoptosis usingflow cytometry (sub-diploid peak) and western blotting (Bcl-2, Caspase-3 and Caspase-8 expression). We found thatAM apoptosis washigher amongCWP patients than thehealthycontrols. Expression ofBcl-2, Caspase-3 and Caspase-8 was higher inAMs from CWP patientsthan in those from the controlsand correlated with increased AM apoptosis. Univariate and multivariate analyses suggested that CWP grade, initial exposure time, exposure time inyears, and CWP onset agewereall associated with altered levels of Bcl-2, Caspase-3 and Caspase-8. Inhibition of TNFR/TNF-α signaling usinganti-TNFR antibody, SOD or NFkB inhibitionreduced AM apoptosisand decreased Bcl-2, Caspase-3 and Caspase-8 expression. These data suggestinhibition of a TNFR/TNF-α signaling pathway is a potentiallyeffective means ofalleviating CWP by inhibiting AM apoptosis.

Serum Resistin Levels May Contribute to an Increased Risk of Acute Cerebral Infarction.

The objective of this study was to investigate the association between serum resistin levels and acute cerebral infarction (ACI). PubMed, SpringerLink, Wiley, EBSCO, Ovid, Web of Science, Wanfang, China National Knowledge Infrastructure, and VIP databases (last updated search in October 2014) were exhaustively searched, and data from the eligible studies were extracted and analyzed to assess the association between serum resistin levels and ACI. STATA software (version 12.0, Stata Corporation, College Station, TX, USA) was utilized for data analysis. Ten studies including 1829 ACI patients and 1557 healthy controls were eligible for inclusion in the meta-analysis. Our major result revealed that ACI patients exhibited higher serum resistin levels compared with healthy controls. Asubgroup analysis based on ethnicity showed a significant association between serum resistin levels and ACI in Asians, but surprisingly not in Caucasians. The results of our meta-analysis suggest that serum resistin levels are associated with an increased risk of ACI.

Relationship of cumulative dust exposure dose and cumulative abnormal rate of pulmonary function in coal mixture workers.

To investigate the dose-response relationship between cumulative dust exposure (CDE) and cumulative abnormal rate of pulmonary function in coal mixture workers. Three hundred and twenty eight coal mixture workers (exposed group) and 169 nondust-exposed workers (control group) were recruited. Basic information data were collected and pulmonary function tests were performed. Pulmonary function was compared between the two groups after comparing smoking behaviors. Pulmonary function indices [forced vital capacity in 1 second after full inspiration (FVC)%, forced expiratory volume (FEV)1%, and FEV1/FVC%] were compared among groups stratified by service length (exposure duration). The relationship between CDE dose and cumulative abnormal rate of pulmonary function in coal mixture workers was analyzed. Abnormal rate of pulmonary function in the exposed group (35.1%) was significantly higher than the control group (10.1%; p < 0.001); FVC%, FEV1%, and FEV1/FVC% in the exposed group decreased significantly compared with the control group (all p < 0.05). Differences in FVC%, FEV1%, and FEV1/FVC% among coal mixture workers stratified by exposure duration in the exposed group were statistically significant (all p < 0.05). The discernible increase in the cumulative abnormal rate was observed, from ≥ 1000 mg/m(3)·years group to ≥ 1700 mg/m(3)·years group. Correlation analysis revealed a positive correlation between the CDE dose and the cumulative abnormal rate of pulmonary function. Higher abnormal pulmonary function rate was found among coal mixture workers, characterized by decreased pulmonary function indices. Our results suggested a positive relationship between CDE dose and cumulative abnormal pulmonary function rate, and a rapid increase in cumulative abnormal rate within a certain range of CDE dose. A lower limit value of 1000 mg/m(3)·years has reference significance.