Protection of H9c2 Myocardial Cells from Oxidative Stress by Crocetin via PINK1/Parkin Pathway-Mediated Mitophagy.

This study aimed to explore the oxidative stress-protective effect of crocetin on H2O2-mediated H9c2 myocardial cells through in vitro experiments, and further explore whether its mechanism is related to the impact of mitophagy. This study also aimed to demonstrate the therapeutic effect of safflower acid on oxidative stress in cardiomyocytes and explore whether its mechanism is related to the effect of mitophagy. Here, an H2O2-based oxidative stress model was constructed and assessed the degree of oxidative stress injury of cardiomyocytes by detecting the levels of lactate dehydrogenase (LDH), creatine kinase (CK), malondialdehyde (MDA), superoxide dismutase (SOD), catalase (CAT), and glutathione peroxidase (GSH Px). Reactive oxygen species (ROS)-detecting fluorescent dye DCFH-DA, JC-1 dye, and TUNEL dye were employed to assess mitochondrial damage and apoptosis. Autophagic flux was measured by transfecting Ad-mCherry-GFP-LC3B adenovirus. Mitophagy-related proteins were then detected via western blotting and immunofluorescence. However, crocetin (0.1-10 µM) could significantly improve cell viability and reduce apoptosis and oxidative stress damage caused by H2O2. In cells with excessive autophagic activation, crocetin could also reduce autophagy flow and the expression of mitophagy-related proteins PINK1 and Parkin, and reverse the transfer of Parkin to mitochondria. Crocetin could reduce H2O2-mediated oxidative stress damage and the apoptosis of H9c2 cells, and its mechanism was closely related to mitophagy.

[Clinical application value and imaging diagnosis of stress fracture].

OBJECTIVE: To discuss the imaging findings of stress fracture, in order to improve the ability of early diagnosis and early treatment of this disease. METHODS: The DR, CT and MRI imaging data of 336 cases of stress fracture from January 2010 to January 2016 were analyzed retrospectively. Early diagnosis ratio in stress fractures by three methods were analyzed using χ²-test. RESULTS: Early diagnosis ratio of three methods as follow: DR was 70.83%(238/332), CT was 55.93%(66/118), and MRI was 73.61%(53/72). There was statistical significance among three methods (χ²=10.15, P=0.006), the early diagnosis ratio of DR was higher than CT (χ²=8.765, P=0.003)and there was no statistical significance between DR and MRI (χ²=0.224, P=0.636). CONCLUSIONS: DR and MRI have better diagnosis of stress fractures while CT is not helpful in the early diagnosis. DR examination is preferred method due to its economical and convenient. MR is the important complement means, which can improve the early diagnosis ratio and provide imaging diagnosis basis for the clinical, so that the disease get early intervention and treatment.