ObjectiveTo summarize the mechanism and research progress of ferroptosis in acute liver injury. MethodThe domestic and foreign literatures related of ferroptosis and acute liver injury were searched and reviewed. ResultsFerroptosis was a newly identified form of iron-dependent cell death. The loss of lipid peroxidation repair activity of glutathione peroxidase 4, the presence of redox active iron and the oxidation of phospholipids containing polyunsaturated fatty acids were considered to be distinctive features of ferroptosis. At present, the research on the regulation of ferroptosis genes involved common liver diseases, including drug-induced liver injury, hepatocellular carcinoma, liver fibrosis, liver ischemia-reperfusion injury, liver failure, nonalcoholic fatty liver and so on. Based on the high correlation between ferroptosis and acute liver injury, chemical therapy targeting ferroptosis could provide individualized treatment for patients with acute liver injury in the future. ConclusionsThe ferroptosis plays a critical role in governing various cellular processes and downstream effects. Its aberrant expression contributes to the development and advancement of acute liver injury through diverse mechanisms. Thoroughly exploring the involvement of the ferroptosis in acute liver injury is of utmost significance, as it holds the potential to unveil novel therapeutic targets for effective management of acute liver injury.
ObjectiveTo investigate the in vitro effect of pseudolaric acid B (PAB) on apoptosis of protoscolece cells and its regulatory effects on angiogenesis and cell apoptosis in the the lesion-host microenvironment tissue in vivo, as well as its possible mechanisms, in order to provide a basis for the clinical development of new alternative drugs for Echinococcus multilocularis. MethodsIn vitro experiments: the protoscoleces, vesicles, germinal cells, human foreskin fibroblasts (HFFs) and normal human liver cells were treated with different concentrations of PAB (0, 2.5, 5, 10, 20, 40, 80, 160 and 320 μmol/L) for 7, 5, 5, 5 and 5 days, then evaluated the survival rate of the protoscoleces, the release level of phosphoglucose isomerase (PGI) from the vesicles, the viability of the germinal cells, as well as the viability of HFFs and normal human liver cells. The protoscoleces and vesicles were fixed with 2.5% glutaraldehyde and used for scanning electron microscopy and transmission electron microscopy observation. Animal experiments: the protoscoleces were isolated from the abdominal lesions of the protected gerbils, and then infected 18 C57BL/6J mice by intraperitoneal injection to establish models, dividing into 3 groups with 6 mice in each group. The model group was given 0.3 mL of PBS by gavage daily, the albendazole (ABZ) group was given 0.3 mL ABZ (100 mg/kg) daily by gavage, the PAB group was given 0.3 mL of PAB (40 mg/kg) by gavage daily. After continuous gavage for 6 weeks, the lesion host microenvironment tissue was taken and ELISA was used to detect the expression levels of vascular endothelial growth factor (VEGF), endothelial nitric oxide synthase (eNOS) and cysteinyl aspartate specific proteinase3 (caspase3), the expression levels of nitric oxide (NO) was detected using a biochemical detection kit, Western blot was used to detect the expression levels of BCL2-associated X protein (Bax), B-cell lymphoma-2 (Bcl2), caspase3, cleaved-caspase3, VEGF, vascular endothelial growth factor receptor 2 (VEGFR2), phosphatidylinositol 3 kinase (PI3K), phosphorylated PI3K (p-PI3K), protein kinase B (AKT) and phosphorylated AKI (p-AKT) protein. ResultsIn vitro experiments: the protoscoleces of Echinococcus multilocularis were cultured with different concentrations of PAB for 7 days in vitro, the protoscoleces of 40, 80, 160 and 320 μmol/L group all died after 6, 4, 2 and 1 day, respectively; PAB exhibited a certain time and concentration dependence on the protoscoleces of Echinococcus multilocularis. After PAB treatment, the release of PGI in culture supernatant of Echinococcus multilocularis gradually increased with the increase of PAB concentration [concentration for 50% of maximal effect value was (24.40±1.42) μmol/L], the vitality of germinal cells was significantly inhibited [half maximal inhibitory concentration value was (15.94±2.55) μmol/L]. PAB had no significant toxicity to mammalian cells. When 20 μmol/L PAB intervention in the protoscoleces for 3 days, the expression levels of Bax and caspase3 proteins were upregulated, while the expression level of Bcl2 protein was downregulated. Animal experiments: compared with the model group, the wet weight of lesions in the PAB and ABZ groups decreased (P<0.01), and the inhibition rates of lesion growth in the PAB and ABZ groups were 91.03% and 74.44%, respectively. The expression of proliferation and angiogenesis indicators (Ki67, CD34, VEGF, VEGFR2, eNOS, NO) were downregulated in the lesion host microenvironment tissues of mice in the ABZ and PAB groups (P<0.05), while the expression of apoptosis related proteins (caspase3, cleaved-caspase3 and Bax) were upregulated and the expression of PI3K/AKT signaling pathway related proteins (p-PI3K and p-AKT) were downregulated (P<0.05). ConclusionPAB has a strong in vitro and in vivo effect against Echinococcus multilocularis, and its mechanism may be related to the inhibition of PI3K/AKT signaling pathway, leading to increased apoptosis and decreased angiogenesis.
Objectives To observe the expression of key proteins in the NLRP3/Caspase-1 pathway of pyroptosis in the mouse model of hepatic Echinococcus multilocularis (Em) infection and explore its correlation. Methods Twenty-five BALB/c mice were randomly divided into the control group and the infected group. The infected group was injected with 0.2 mL suspension of protoscolex (including 3 000 protoscoleces) injected under the liver capsule to establish a model of secondary infection with hepatic Em. The control group was treated without any treatments and conventional feeding was conducted. The mice were sacrificed at 1, 2, 3, and 5 months after infection. The liver was harvested and observed for gross morphology. HE staining and transmission electron microscopy were performed to observe the histopathological changes. The expressions of key proteins in the NLRP3/Caspase-1 pathway of pyroptosis and the IL-1β, a downstream factor of pyroptosis in the liver were detected by immunohistochemistry, Western blot and ELISA. Results Compared with the control group, the cystic lesions on the surface of liver tissues in the infected group mice gradually increased and protruded from the liver surface with the extension of infection time. HE staining showed various pathological changes such as inflammatory cell infiltration and fibrous hyperplasia in the liver lesions to varying degrees. After 2 months of Em infection, transmission electron microscope observation showed that the cell membrane of hepatocytes were broken and discontinuous, conforming to the "punching" phenomenon of pyroptosis. The results of ELISA showed that the concentration of IL-1β in liver homogenate of mice after 1, 2, 3 and 5 months of Em infection were significantly higher than that of the control group, and the difference was statistically significant (F=127.2, P<0.05). Immunohistochemical examination showed that the positive cell ratios of Caspase-1 and NLRP3 in liver of mice infected with Em at 1, 2, 3 and 5 months, were higher than that of the control group, and the difference were statistically significant (F=114.6, P<0.05; F=85.89, P<0.05). The Western blot results showed that the relative expression levels of Caspase-1, Xiaopi D, and NLRP3 proteins in the liver of infected mice showed a trend of first increasing (the expression of Caspase-1 and GSDMD reached their peak at 1 month of infection, while the expression of NLRP3 reached its peak at 2 months of infection) and then decreasing. There were statistically significant differences between the infection groups at different time points and the control group, as well as comparison between the infection groups at different time points there were also statistically significant differences (all P<0.05). Conclusion It is feasible to establish mouse Em infection model by “skin incision and liver puncture through abdominal muscle layer”. There is a new type of programmed cell death, pyroptosis, after Em infection in mouse liver. It may play a role in inflammation amplification through pyroptosis NLRP3/Caspase-1 pathway.