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Fine particulate matter (PM 2.5) is a risk factor for pulmonary diseases and lung cancer, and inhaled PM 2.5 is mainly deposited in the bronchial epithelium. In this study, we investigated the effect of long-term exposure to low-dose PM 2.5 on BEAS-2B cells derived from the normal bronchial epithelium. BEAS-2B cells chronically exposed to a concentration of 5 µg/ml PM 2.5 for 30 passages displayed the phenotype promoting epithelial-mesenchymal transition (EMT) and cell invasion. Cellular internalization of exosomes (designated PM 2.5 Exo) extracted from BEAS-2B cells chronically exposed to low-dose PM 2.5 promoted cell invasion in vitro and metastatic potential in vivo. Hence, to identify the key players driving phenotypic alterations, we analyzed microRNA (miRNA) expression profiles in PM 2.5 Exo. Five miRNAs with altered expression were selected: miRNA-196b-5p, miR-135a-2–5p, miR-3117–3p, miR-218–5p, and miR-497–5p. miR-196b-5p was the most upregulated in both BEAS-2B cells and isolated exosomes after PM 2.5 exposure. In a functional validation study, genetically modified exosomes overexpressing a miR-196b-5p mimic induced an enhanced invasive phenotype in BEAS-2B cells. Conversely, miR-196b-5p inhibition diminished the PM 2.5 -enhanced EMT and cell invasion. These findings indicate that exosomal miR-196b-5p may be a candidate biomarker for predicting the malignant behavior of the bronchial epithelium and a therapeutic target for inhibiting PM 2.5 -triggered pathogenesis. • Exosomes from BEAS-2B cells chronically exposed to low-dose PM 2.5 promote the invasiveness of adjacent cells. • Exosomal miR-196b-5p may predict and trigger the malignant behavior of adjacent cells. • Exosomes harboring the miR-196b-5p inhibitor may suppress PM2.5-triggered pathogenesis. [ABSTRACT FROM AUTHOR]

Endometrial receptivity is essential for successful embryo implantation and pregnancy initiation and is regulated via various signaling pathways. Adiponectin, an important adipokine, may be a potential regulator of reproductive system functions. The aim of the present study was to elucidate the regulatory role of adiponectin receptor 1 (ADIPOR1) in endometrial receptivity. The endometrial receptivity between RL95-2 and AN3CA cell lines was confirmed using an in vitro JAr spheroid attachment model. 293T cells were transfected with control or short hairpin (sh)ADIPOR1 vectors and RL95-2 cells were transduced with lentiviral particles targeting ADIPOR1. Reverse transcription-quantitative PCR and immunoblot assays were also performed. ADIPOR1 was consistently upregulated in the endometrium during the mid-secretory phase compared with that in the proliferative phase and in receptive RL95-2 cells compared with that in non-receptive AN3CA cells. Stable cell lines with diminished ADIPOR1 expression caused by shRNA showed reduced E-cadherin expression and attenuated in vitro endometrial receptivity. ADIPOR1 regulated AMP-activated protein kinase (AMPK) activity in endometrial epithelial cells. Regulation of AMPK activity via dorsomorphin and 5-aminoimidazole-4-carboxamide ribonucleotide affected E-cadherin expression and in vitro endometrial receptivity. The ADIPOR1/AMPK/E-cadherin axis is vital to endometrial receptivity. These findings can help improve fertility treatments and outcomes. [ABSTRACT FROM AUTHOR]

Background: Colistin (polymyxin E) is an important constituent of the polymyxin class of cationic polypeptide antibiotics. Intrarenal oxidative stress can contribute to colistin-induced nephrotoxicity. Nicotinamide adenine dinucleotide 3-phosphate oxidases (Noxs) are important sources of reactive oxygen species. Among the various types of Noxs, Nox4 is predominantly expressed in the kidney.Objectives: We investigated the role of Nox4 and benefit of Nox4 inhibition in colistin-induced acute kidney injury using in vivo and in vitro models.Methods: Human proximal tubular epithelial (HK-2) cells were treated with colistin with or without NOX4 knockdown, or GKT137831 (most specific Nox1/4 inhibitor). Effects of Nox4 inhibition on colistin-induced acute kidney injury model in Sprague-Dawley rats were examined.Results: Nox4 expression in HK-2 cells significantly increased following colistin exposure. SB4315432 (transforming growth factor-β1 receptor I inhibitor) significantly inhibited Nox4 expression in HK-2 cells. Knockdown of NOX4 transcription reduced reactive oxygen species production, lowered the levels of pro-inflammatory markers (notably mitogen-activated protein kinases) implicated in colistin-induced nephrotoxicity and attenuated apoptosis by altering Bax and caspase 3/7 activity. Pretreatment with GKT137831 replicated these effects mediated by downregulation of mitogen-activated protein kinase activities. In a rat colistin-induced acute kidney injury model, administration of GKT137831 resulted in attenuated colistin-induced acute kidney injury as indicated by attenuated impairment of glomerulus function, preserved renal structures, reduced expression of 8-hydroxyguanosine and fewer apoptotic cells.Conclusions: Collectively, these findings identify Nox4 as a key source of reactive oxygen species responsible for kidney injury in colistin-induced nephrotoxicity and highlight a novel potential way to treat drug-related nephrotoxicity. [ABSTRACT FROM AUTHOR]

Chronic rhinosinusitis (CRS) is a highly prevalent disease characterized by mucosal inflammation of the nose and paranasal sinuses. CRS can be divided into two main categories, CRS with nasal polyps (NPs; CRSwNP) and CRS without NPs (CRSsNP). Although the pathophysiology of CRS remains unclear, DNA methylation has been implicated in the etiology of CRSwNP. The aim of the present study was to elucidate whether DNA methylation of specific genes is involved in the development of NPs. In total, 18 individuals were included in the present study, and were divided into three groups: CRSwNP (n=7), CRSsNP (n=7) and healthy controls (n=4). NP tissues were obtained from the seven patients with CRSwNP and biopsies of the inferior turbinate mucosa from all three groups were used as controls. Methylated genes detected by methyl-CpG-binding domain sequencing were validated by methylation-specific polymerase chain reaction (PCR), bisulfite sequencing, and reverse transcription-quantitative PCR (RT-qPCR). Methyl-CpG-binding domain sequencing identified 43,674 CpG islands in 518 genes. The promotor regions of 10 and 30 genes were hypermethylated and hypomethylated, respectively, in NP samples compared with controls. The top four genes with altered hypomethylation in NP tissues were, Keratin 19 (KRT19), nuclear receptor subfamily 2 group F member 2 (NR2F2), A Disintegrin-like And Metallopeptidase (Reprolysin Type) with Thrombospondin type 1 motif 1 (ADAMTS1) and zinc finger protein 222 (ZNF222). RT-qPCR demonstrated that the expression levels of KRT19, NR2F2 and ADAMTS1 were significantly increased in NP tissues; however, there was no difference in the levels of ZNF222 between NP and control tissues. Further studies are required to confirm the relevance of these epigenetic modifications in the mechanisms underlying NP formation. [ABSTRACT FROM AUTHOR]

Background: Cancer metastasis is a multi-step event including epithelial-to-mesenchymal transition (EMT). Breast cancer metastasis suppressor 1 (BRMS1) is a novel metastasis suppressor protein without anti-proliferating activity. However, a detailed underlying mechanism by which BRMS1 attenuates cancer cell EMT and invasion remained to be answered. In the present study, we report an additional mechanism by which BRMS1 attenuates Transforming growth factor-beta1 (TGF-β1)-induced breast cancer cell EMT and invasion.Methods: Experimental analysis involving chromosome immunoprecipitation (ChIP) and luciferase reporter assays were used to validate hypoxia inducible factor-1alpha (HIF-1α) as a transcriptional regulator of TWIST1 and Snail. Quantitative RT-PCR was used to analyze transcript expression. Immunoblotting and immunofluorescence were used to analyze protein expression. Matrigel-coated in vitro invasion insert was used to analyze cancer cell invasion.Results: BRMS1 strongly inhibited TGF-β1-induced breast cancer cell EMT and invasion. Unexpectedly, we observed that BRMS1 downregulates not only TWIST1 but also Snail expression, thereby inhibiting breast cancer cell invasion. In addition, we provide evidence that HIF-1α is required for Snail and TWIST1 expression. Further, BRMS1 reduced TGF-β1-induced HIF-1α transcript expression through inactivation of nuclear factor kappaB (NF-κB).Conclusion: Collectively, the present study demonstrates a mechanical cascade of BRMS1 suppressing cancer cell invasion through downregulating HIF-1α transcript and consequently reducing Snail and TWIST1 expression. [ABSTRACT FROM AUTHOR]