Down-Regulation of Nogo-B Expression as a Newly Identified Feature of Intrahepatic Cholangiocarcinoma

Inhibition of miR-29b-1-5p Attenuates Inflammatory Response and Pulmonary Fibrosis in LPS-Induced Acute Lung Injury by Regulating RTN4 Expression

Objective

Acute lung injury (ALI) is a severe respiratory disorder causing alveolar-capillary barrier, leading to a high rate of morbidity and death in critically ill individuals. microRNAs (miRNAs)-mediated mechanism in the pathogenesis of ALI has attracted much interest. Herein, we attempt to characterize a candidate miRNA and its downstream target that is linked to the pathogenesis of ALI.

Methods

LPS-conditioned MH-S cells were treated with miR-29a-1-5p mimic, inhibitor, and RNT4 expression vector, and the ALI animal model was injected with agomir and antagomir of miR-29b-1-5p and RNT4 expression vector, in which the pro-inflammatory cytokine production, cell viability and apoptosis, myeloperoxidase (MPO) activity, wet/dry (W/D) ratio, and expression of TGF-β1, α-smooth muscle actin (α-SMA), E-cadherin, and vimentin were examined. miR-29a-1-5p inhibition of RTN4 translation was confirmed by luciferase activity assays.

Results

An elevated miR-29a-1-5p expression was demonstrated in LPS-conditioned MH-S cells. miR-29a-1-5p inhibitor transfection attenuated the production of pro-inflammatory cytokines and MH-S cell viability but enhanced the apoptosis. miR-29a-1-5p inhibition of RTN4 translation was demonstrated in the setting of LPS-induced ALI. LPS-induced murine models demonstrated upregulated miR-29a-1-5p. Intravenous injection of miR-29b-1-5p agomir attenuated mouse lung injury and pulmonary fibrosis. RTN4 overexpression resisting to miR-29a-1-5p overexpression was demonstrated in LPS-induced murine models.

Conclusion

The findings obtained from the study that disturbing the action of miR-29a-1-5p may be a novel therapeutic strategy for preventing ALI.

Reticulon 2 promotes gastric cancer metastasis via activating endoplasmic reticulum Ca2+ efflux-mediated ERK signalling

Gastric cancer ranks fourth for mortality globally among various malignant tumours, and invasion and metastasis are the major reason leading to its poor prognosis. Recently, accumulating studies revealed the role of reticulon proteins in cell growth and transmigration. However, the expression and biological function of reticulon proteins in human gastric cancer remain largely unclear. Herein, we explored the potential role of reticulon 2 (RTN2) in the progression of gastric cancer. Tissue microarray was used to determine the expression levels of RTN2 in 267 gastric cancer patients by immunohistochemistry. Gastric cancer cell lines were utilised to examine the influences of RTN2 on cellular migration and invasion abilities, epithelial-to-mesenchymal transition (EMT) and signalling pathway. In vivo studies were also performed to detect the effect of RTN2 on tumour metastasis. We found that RTN2 expression was notably upregulated in tumour tissues compared to pericarcinomatous tissues. High RTN2 expression was positively correlated with patients’ age, vessel invasion, tumour invasion depth, lymph node metastasis and TNM stage. Besides, high RTN2 staining intensity was associated with adverse survival which was further identified as an independent prognostic factor for gastric cancer patients by multivariate analysis. And the predictive accuracy was also improved when incorporated RTN2 into the TNM-staging system. RTN2 could promote the proliferation, migration and invasion of gastric cancer cells in vitro and lung metastasis in vivo. Mechanistically, RTN2 interacted with IP3R, and activated ERK signalling pathway via facilitating Ca²⁺ release from the endoplasmic reticulum, and subsequently drove EMT in gastric cancer cells. These results proposed RTN2 as a novel promotor and potential molecular target for gastric cancer therapies.