Résumé
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.
Résumé
Objective:To investigate the effects of high-energy shock and vibration on cortex injury and peripheral blood immune cells in goats.Methods:Seventeen Boer goats without gender preference were selected. By using random number tables, the goats were divided into normal control group ( n=5) and shock and vibration injury group ( n=12). The goats in the normal control group were anatomized routinely and their brain was collected after being sacrificed without any other treatment. The goats in the high-energy shock and vibration model group were placed on a loading table (part of the BY10-100 instant shock and vibration simulation platform) in a restrained state, and made into a high-energy shock and vibration injury model induced by a vertical impact waveform generator. The intravenous blood samples were taken from the goats in the shock and vibration injury group before and at 0, 3, 6 and 24 hours after injury.Then, the goats were sacrificed and the following procedures were the same as the normal control group. At 24 hours after injury, the brain injury and the histopathological changes of the cerebral cortex in the normal control group and shock and vibration injury group were observed by gross pathological and anatomical examination and HE staining. The mRNA expression of zonula occludens 1 (ZO-1), tight junction protein 5 (Claudin-5), glial fibrillary acidic protein (GFAP), ionized calcium binding adaptor molecule 1 (IBA-1), interleukin (IL)-1β, IL-6 and cluster of differentiation antigen 177 (CD177) of the cerebral cortex in the normal control group and shock and vibration injury group were measured through fluorogenic quantitative polymerase chain reaction. The expression of ZO-1 and Claudin-5 proteins of the cerebral cortex in the normal control group and shock and vibration injury group were detected by Western blotting. Hematology analyzer and coagulation analyzer were used to detect white blood cell count, neutrocyte, lymphocyte, monocyte, prothrombin time 1 (PT-1), prothrombin time international normalized ratio (PT-INR), activated partial thromboplastin time (APTT), thrombin time (TT), prothrombin activity (PTA) and fibrinogen (FIB) levels in goats of the shock and vibration injury group before and at 0, 3, 6 and 24 hours after injury, respectively. Results:At 24 hours after injury, no visible contusion or necrosis was found in goat brain tissue in the shock and vibration injury group; the cerebral micro-vessels presented with a local dilation, hyperemia, edema, aggregation of inflammatory cells, disruption of vessel walls and leakage of red blood cells. These changes were not observed in the normal control group. In the shock and vibration injury group, ZO-1 and Claudin-5 mRNA expressions in the cerebral cortex were 0.25±0.10 and 0.09(0.04, 0.44) respectively, which were significantly lower than those of the normal control group [1.00±0.15 and 0.99(0.80, 1.20)]; GFAP, IBA-1, IL-1β, IL-6 and CD177 mRNA expression levels were 4.40(3.88, 6.75), 2.60±1.07, 3.04±0.51, 2.71±0.45 and 2.93±0.62 respectively, which were significantly higher than those of the normal control group [1.00(0.78, 1.22), 1.00±0.37, 1.00±0.27, 1.00±0.57 and 1.00±0.35]; ZO-1 and Claudin-5 protein expression levels were 0.41±0.06 and 0.42±0.11 respectively, which were significantly lower than those of the normal control group (1.08±0.12 and 0.91±0.23) (all P<0.01). In the shock and vibration injury group, the levels of white blood count, neutrocyte, and lymphocyte in peripheral blood were (13.7±3.3)×10 9/L, (35.3±14.8)% and (57.2±15.1)% respectively before injury, (19.4±3.1)×10 9/L, (60.5±12.5)% and (33.6±14.2)% respectively at 3 hours after injury, and (20.6±3.6)×10 9/L, (63.6±13.0)% and (30.9±15.0)% respectively at 6 hours after injury. By contrast, the levels of white blood count and neutrocyte were significantly increased but the level of lymphocyte was significantly decreased at 3 and 6 hours after injury ( P<0.05 or 0.01); the levels of the above indicators showed no significant changes at 0 and 24 hours after injury (all P>0.05); the level of monocyte did not change significantly at all time points before and after injury (all P>0.05). The levels of PT-1, PT-INR, APTT, TT, PTA and FIB in the shock and vibration injury group did not change significantly at each time point before and after injury (all P>0.05). Conclusion:Cerebral cortex microvascular injury and disruption of blood-brain barrier can be initiated in the early stage of high-energy shock and vibration injury in goats, accompanied by the presence of central and peripheral inflammatory response.