Up-regulation of MiR-146b-5p Inhibits Fibrotic Lung Pericytes via Inactivation of the Notch1/PDGFRß/ROCK1 Pathway.

Lung fibrosis is a serious human pathology. MiR-146b-5p is down-regulated in idiopathic pulmonary fibrosis, and the Notch1/PDGFRß/ROCK1 pathway is activated. However, the relation between miR-146b-5p and the Notch1/PDGFRß/ROCK1 pathway in lung fibrosis remains unclear. To investigate the function of miR-146b-5p in lung fibrosis, an in vivo model of lung fibrosis was established in mice by bleomycin. The fibrosis in lung tissues of mice was observed by HE, Masson and Sirius Red staining. Lung pericytes were isolated and identified by fluorescence microscopy. Immunofluorescence staining and Western blot were used to investigate the expression of desmin, NG2, collagen I and α-SMA. CCK8 assay was used to assess the cell viability, and flow cytometry was performed to evaluate the cell cycle in pericytes. Furthermore, the correlation between miR-146b-5p and Notch1 was analysed by Spearman analysis. The mechanism by which miR-146b-5p affects pericytes and lung fibrosis via the Notch1/ PDGFRß/ROCK1 pathway was explored by RT-qPCR, Western blot, immunofluorescence staining and dual luciferase reporter gene assay. In bleomycin-treated mice, miR-146b-5p was down-regulated, while Notch1 was up-regulated. Up-regulation of miR-146b-5p significantly inhibited the viability and induced G1 phase arrest of lung pericytes. MiR-146b-5p mimics up-regulated miR-146b-5p, desmin, and NG2 and down-regulated α-SMA and collagen I in the lung pericytes. Additionally, miR-146b-5p was negatively correlated with Notch1, and miR-146b-5p interacted with Notch1. Over-expression of miR-146b-5p inactivated the Notch1/PDGFRß/ROCK1 pathway. Our results indicate that up-regulation of miR-146b-5p inhibits fibrosis in lung pericytes via modulation of the Notch1/PDGFRß/ROCK1 pathway. Thus, our study might provide a novel target against lung fibrosis.

Increased Dickkopf-1 expression in patients with unexplained recurrent spontaneous miscarriage.

Wnt pathways play an important role in pre-implantation embryo development, blastocyst implantation, and post-implantation uterine decidualisation. However, little is known about the potential role that Wnt signaling plays in patients with unexplained recurrent spontaneous miscarriage (URSM), and no single biomarker with a high predictive value of maternally caused URSM has been identified. We aim to study the molecular mechanisms by which the Wnt pathway controls the progression of early pregnancy by investigating the expression of Dickkopf-1 (DKK1), one of the Wnt agonists, in URSM patients. Plasma and fresh decidual tissues samples were collected from 59 subjects (29 patients with URSM and 30 patients with normal, early pregnancy). Time-resolved immunofluorometric assay system and quantitative real-time RT-PCR were used to determine the serum levels of DKK1 and DKK1 mRNA in the deciduas, respectively. Western blot and immunohistochemistry were used to measure DKK1 protein levels in the deciduas. Serum DKK1 levels were significantly higher in URSM patients compared to the control group (P < 0·001); the expression of DKK1 mRNA and protein in URSM patients were higher relative to healthy controls (P = 0·013). Glandular epithelium from decidual tissues demonstrated cytoplasmic signals for DKK1 in URSM patients, and DKK1 did not stain in healthy controls. Furthermore, serum DKK1 levels significantly correlated with those in the decidual tissues. Our study suggests that DKK1 may be a valuable biomarker of URSM; it can be reliably and conveniently detected in serum, thus obviating the need for decidual tissue analysis.