Involvement of intracellular organelle stress, autophagy and ferroptosis in cobalt chloride-induced vascular smooth muscle cell injury / 中国临床药理学与治疗学

ABSTRACT

AIM: To investigate the relationship between vascular smooth muscle cell (VSMC) injury, organelle stress response and autophagic cell death (autophagy) and ferroptosis induced by the chemical hypoxia inducer cobalt chloride (CoCl2) through the bioinformatics analysis and in vitro cell experimentation. METHODS: The dataset GSE119226 of VSMC treated with cobalt chloride was acquired from the gene expression database (GEO). The R language was used to investigate the relationship between CoCl2 treatment and organelle stress response (Golgi stress, endoplasmic reticulum stress) and two forms of cell death (ferroptosis and autophagic cell death). With primary cultured rat VSMC (rVSMC) and CoCl2-induced anoxia model, the changes in cell viability were detected by CCK-8 method, and reactive oxygen species (ROS) levels were measured using DCFH-DA method. The expression levels of HIF-1α (a key molecule in hypoxia), Golgi stress markers GM130 and p115, endoplasmic reticulum stress markers GRP78 and CHOP, autophagy markers LC3-II / LC3-I and Beclin1, and ferroptosis markers GPx4 and xCT were detected by Western blot. The effect of inducing or inhibiting organelle stress and cell death on the CoCl2-induced cell damage was also observed. RESULTS: Differentially expressed genes analysis of GSE119226 dataset showed that CoCl2 treatment of VSMCs had significant effects on organelle function and stress response, autophagy and ferroptosis-related genes, in which endoplasmic reticulum stress, protein processing in endoplasmic reticulum, regulation of Golgi to plasma membrane protein transport, autophagy / autophagic cell death, and ferroptosis pathways were remarkably enriched. The results of in vitro experiment showed that compared with normal rVSMC, cell viability was significantly decreased after CoCl2 treatment, as well as HIF-1α protein expression and ROS levels in rVSMCs were increased. In rVSMC treated with Co-Cl2, the expression levels of Golgi structural proteins GM130 and p115 (reflecting the occurrence of Golgi stress) were decreased, while the markers GRP78 and CHOP (reflecting the occurrence of endoplasmic reticulum stress) were increased. At the same time, CoCl2 treatment also reduced the expression of autophagy markers LC3-II/LC3-I and Beclin1 (indicating the decrease levels of autophagy), while the expression of ferroptosis markers GPx4 and xCT were decreased (indicating the occurrence of ferroptosis). Compared with CoCl2 treatment group, induced Golgi stress, endoplasmic reticulum stress, or ferroptosis could further reduce cell viability, while inhibition of these processes could improve cell viability. On the other hand, increasing the level of autophagy can improve the cell viability. CONCLUSION: Hypoxia induced by cobalt chloride can lead to VSMC injury. Golgi stress, endoplasmic reticulum stress, ferroptosis, and the reduction of autophagy level play an important role in it. Inhibition of organelle stress response and ferroptosis, or increase of autophagy level can improve VSMC injury caused by cobalt chloride.