Mild Hypothermia Prevents NO-Induced Cytotoxicity in Human Neuroblastoma Cells Via Induction of COX-2.

The cold-inducible protein RBM3 mediates hypothermic neuroprotection against nitric oxide (NO)-induced cell death. Meanwhile, it is well-known that cyclooxygenase-2 (COX-2) is upregulated by RBM3 in several types of cells; however, it is still unclear whether COX-2 contributes to the neuroprotective effects of mild hypothermia/RBM3 against NO-induced cell death. Using human SH-SY5Y neuroblastoma cells, it was revealed that NO remarkably downregulates the expression of COX-2 at both mRNA and protein levels. When COX-2 was silenced using siRNA technique, cells became more sensitive to NO-induced cell death. Conversely, the overexpression of COX-2 significantly prevented NO-induced cell death in SH-SY5Y cells, indicating a pro-survival role of COX-2. Upon mild hypothermia pre-treatment, COX-2 was notably induced at both mRNA and protein levels; however, COX-2 silencing abrogated hypothermia-related neuroprotection against NO-induced cell death. Furthermore, it was revealed that either silencing or overexpression of RBM3 had no effects on the expression of COX-2 in SH-SY5Y cells. These findings suggest that mild hypothermia could protect neuroblastoma cells against NO-induced cell death by inducing COX-2 in a RBM3-independent manner.

Potentials of the elevated circulating miR-185 level as a biomarker for early diagnosis of HBV-related liver fibrosis.

Early diagnosis of liver fibrosis is critical for early intervention and prognosis of various chronic liver diseases. Conventional repeated histological assessment is impractical due to the associated invasiveness. In the current study, we evaluated circulating miR-185 as a potential biomarker to predict initiation and progression of liver fibrosis. We found that miR-185 was significantly up-regulated in blood specimens from patients with HBV-liver fibrosis and rats with liver fibrosis, the miR-185 levels were correlated with liver fibrosis progression, but not with the different viral loads in HBV-infected patients. miR-185 was observed in collagen deposition regions during advanced liver fibrosis. We found that differences in miR-185 levels facilitated the discrimination between early-staged or advanced-staged liver fibrosis and the healthy controls with high specificity, sensitivity, and likelihood ratio using receiver-operator characteristic analysis. miR-185 targeted SREBF1, and increased expression of COL1A1 and a-SMA genes that are hallmarks of liver fibrosis. Our data supported that circulating miR-185 levels could be used as potential biomarkers for the early diagnosis of liver fibrosis.