Inhibition of miR‐337‐3p involved in the protection of CoCl₂‐induced injury in PC12 cells via activating JAK2/STAT3 signaling pathway

Abstract

Objective To investigate the possibility of microRNA (miR)‐337‐3p in the protection of hypoxia‐induced injury in PC12 cells via modulating the JAK2/STAT3 signaling pathway. Methods Dual‐luciferase reporter assay analyzed the relationship between the miR‐337‐3p and JAK2. PC12 cells were divided into normal, CoCl2, CoCl2 + NC, CoCl2 + inhibitors, CoCl2 + JAK2, and CoCl2 + mimics + JAK2 groups. Then, PC12 cell viability and apoptosis were measured by the 3‐(4,5‐dimethyl‐2‐thiazolyl)‐2,5‐diphenyl‐2H‐tetrazolium bromide (MTT) and Annexin‐V‐fluorescein isothiocyanate/propidium iodide methods. Quantitative real‐time polymerase chain reaction and Western blot analysis were used to determine expressions. Besides, the intracellular reactive oxygen species (ROS) was examined by dichloro‐dihydro‐fluorescein diacetate (DCFH‐DA) while the mitochondrial membrane potential (MMP) by using JC‐1. Results The negative targeting relationship between miR‐337‐3p and JAK2 was confirmed. When compared with the normal group, miR‐337‐3p was increased while JAK2 and STAT3 were decreased in CoCl2‐induced PC12 cells, with decreased cell viability. Moreover, either miR‐337‐3p inhibitor or JAK2 overexpression could partially reverse CoCl2‐induced decrease in PC12 cell viability. Besides, CoCl2 could also trigger PC12 cell apoptosis by increasing cleaved caspase 3 and Bax but decreasing Bcl‐2 and Bcl‐XL, which, however, were abolished with the transfection of miR‐337‐3p inhibitors or lentivirus transfection to activate JAK2. Compared with the CoCl2 group, the average of fluorescent signals of ROS in the CoCl2 + inhibitors group and the CoCl2 + JAK2 group was lower, while the activities of superoxide dismutase, catalase, glutathione peroxidase, and total anti‐oxidative capacity were higher, together with an increase in MMP. Conclusion Inhibiting miR‐337‐3p could activate the JAK2/STAT3 signaling pathway to suppress CoCl 2‐induced cytotoxicity and apoptosis and ameliorate oxidative stress and MMP in PC12 cells.

Propofol Attenuates Hypoxia-Induced Inflammation in BV2 Microglia by Inhibiting Oxidative Stress and NF-κB/Hif-1α Signaling

“…In this study, we chose CoCl 2 treatment to mimic hypoxia. CoCl 2 is known as a hypoxia-mimetic agent in cell line models, as it induces biochemical and molecular reactions similar to those observed under hypoxic conditions [31][32][33][34]. In our study, we observed that with prolonged incubation with CoCl 2 , the expression of TNF-α, IL-1β, IL-6, and iNOS significantly increased in BV2 cells (Figure 1).…”

PGC‐1 alpha regulates mitochondrial biogenesis to ameliorate hypoxia‐inhibited cementoblast mineralization

“…When cementoblasts were treated with 30 μM CoCl 2 for 24 and 48 h, HIF‐1α expression also increased in the hypoxic group compared to the control group, in a time‐dependent manner (Figure 2D). Finally, a treatment concentration of 30 μM CoCl 2 was chosen for subsequent experiments 31 …”

Molecular Mechanisms of PD-1 and PD-L1 Activity on a Pan-Cancer Basis: A Bioinformatic Exploratory Study

“…In concordance with this, high expression of hsa-miR-337-3p was associated with poor outcomes in these cancer types ( Figure 3 ). There is also experimental evidence to support the ability of this microRNA to suppress expression of JAK2 [ 29 , 30 ] via decreased luciferase activity upon co-transfection of the JAK2 3′UTR luciferase reporter and hsa-miR-337-3p, and decreased JAK2 protein levels upon overexpression of the microRNA in liver cancer cell lines. It should be noted, however, that the study by Zuo and colleagues [ 29 ] was conducted in hepatocellular carcinoma cells and hsa-miR-337-3p acted as a tumor suppressor and suppressed proliferation and invasion.…”