Involvement of microRNA/cystine/glutamate transporter in cold-stressed gastric mucosa injury.

Stress ulcers are complicated by severe trauma and other critical diseases, the mechanism of which remains unclear. An increasing number of studies have shown that microRNAs (miRNAs) are important regulators of stress responses such as hypoxia, abnormal temperature, and inflammation. The evidence indicates that miRNAs are also involved in regulating stress-induced ulcers. Recently, we demonstrated that gastric mucosal injury induced by aspirin is related to the reduction of glutamate levels by inhibition of cystine/glutamate transporter (xCT) activity. In the present study, the effect of a miRNA/xCT on gastric mucosal injury induced by cold stimulation was investigated. We found that cold stimulation induced gastric mucosa injury with a reduction in glutamate levels and xCT activity and upregulation of miR-143, miR-152, and miR-181 expression. Exogenous glutamate significantly alleviated gastric mucosa injury by cold stimulation. In vitro experiments demonstrated that treatment with miR-143, miR-152, or miR-181 mimics directly induced cell damage. The effects of these mimics were alleviated by exogenous glutamate. The present study suggests that miR-143, miR-152, and miR-181 are involved in cold stimulation-induced acute gastric mucosal injury. Furthermore, the regulatory effect of miRNAs on gastric mucosa injury induced by cold stimulation is related to a decrease in glutamate release by reduction of cystine/glutamate transporter activity.

Calcitonin gene­related peptide­mediated pharmacological effects in cardiovascular and gastrointestinal diseases (Review).

Calcitonin gene­related peptide (CGRP) is the predominant neurotransmitter located in sensory nerves. This peptide is extensively distributed in central and peripheral tissues. CGRP causes relaxation of cardiovascular smooth muscle cells and confers protection against ischaemic myocardium and cardiac remodeling. The pharmacological effects of nitroglycerine and rutaecarpine have been demonstrated to be associated with an increase in the synthesis and release of CGRP. In the gastrointestinal tissues, CGRP participates in the regulation of gastrointestinal function, and exerts protective effects on gastric mucosa. Rutaecarpine, capsaicin and its derivatives, such as evodiamine, decrease gastric mucosal damage induced by several factors, including increased synthesis and release of CGRP. Taken together, this review focuses on the pharmacological effects of several CGRP related canonical drugs and suggests that synthesis and secretion of CGRP exhibit significant therapeutic effects in the occurrence and development of cardiovascular and gastrointestinal diseases.

Involvement of microRNAs-MMPs-E-cadherin in the migration and invasion of gastric cancer cells infected with Helicobacter pylori.

It has been found that Helicobacter pylori （H. pylori）is not only the main cause of gastric cancer, but also closely related to its metastasis. E-cadherin cleavage induced by matrix metalloproteinases (MMPs) plays an important role in the tumor metastasis. In the present study, we investigated the role of microRNAs-MMPs-E-cadherin in migration and invasion of gastric cancer cells treated with H. pylori. The results showed that H. pylori induced migration and invasion of SGC-7901 cells with a down-regulation of E-cadherin expression, which were abolished by MMPs knock down, E-cadherin overexpression, mimics of miR128 and miR148a. MiR128/miR148a inhibitors restored MMP-3/MMP-7 expression, down-regulated E-cadherin level, and accelerated cellular migration and invasion. This study suggests that H. pylori induces migration and invasion of gastric cancer cells through reduction of E-cadherin function by activation of MMP-3, - 7. The present results also suggest that the activated MMPs/E-cadherin pathway is related with down-regulation of miR128/miR148a in the human gastric cancer cells infected with H. pylori.