Metastatic cancer cells can develop anoikis resistance in the absence of substrate attachment and survive to fight tumors. Anoikis is mediated by endogenous mitochondria-dependent and exogenous death receptor pathways, and studies have shown that caspase-8-dependent external pathways appear to be more important than the activity of the intrinsic pathways. This paper reviews the regulation of anoikis by external pathways mediated by death receptors. Different death receptors bind to different ligands to activate downstream caspases. The possible mechanisms of Fas-associated death domain (FADD) recruitment by Fas and TNF receptor 1 associated-death domain (TRADD) recruitment by tumor necrosis factor receptor 1 (TNFR1), and DR4- and DR5-associated FADD to induce downstream caspase activation and regulate anoikis were reviewed. This review highlights the possible mechanism of the death receptor pathway mediation of anoikis and provides new insights and research directions for studying tumor metastasis mechanisms.

Background: Pulmonary fibrosis is a major category of end-stage changes in lung diseases, characterized by lung epithelial cell damage, proliferation of fibroblasts, and accumulation of extracellular matrix. Peroxiredoxin 1 (PRDX1), a member of the peroxiredoxin protein family, participates in the regulation of the levels of reactive oxygen species in cells and various other physiological activities, as well as the occurrence and development of diseases by functioning as a chaperonin. Methods: Experimental methods including MTT assay, morphological observation of fibrosis, wound healing assay, fluorescence microscopy, flow cytometry, ELISA, western blot, transcriptome sequencing, and histopathological analysis were used in this study. Results: PRDX1 knockdown increased ROS levels in lung epithelial cells and promoted epithelial-mesenchymal transition (EMT) through the PI3K/Akt and JNK/Smad signalling pathways. PRDX1 knockout significantly increased TGF-β secretion, ROS production, and cell migration in primary lung fibroblasts. PRDX1 deficiency also increased cell proliferation, cell cycle circulation, and fibrosis progression through the PI3K/Akt and JNK/Smad signalling pathways. BLM treatment induced more severe pulmonary fibrosis in PRDX1-knockout mice, mainly through the PI3K/Akt and JNK/Smad signalling pathways. Conclusions: Our findings strongly suggest that PRDX1 is a key molecule in BLM-induced lung fibrosis progression and acts through modulating EMT and lung fibroblast proliferation; therefore, it may be a therapeutic target for the treatment of BLM-induced lung fibrosis.

Excessive alcohol intake can significantly reduce cognitive function and cause irreversible learning and memory disorders. The brain is particularly vulnerable to alcohol-induced ROS damage; the hippocampus is one of the most sensitive areas of the brain for alcohol neurotoxicity. In the present study, we observed significant increasing of intracellular ROS accumulations in Peroxiredoxin II (Prx II) knockdown HT22 cells, which were induced by alcohol treatments. We also found that the level of ROS in mitochondrial was also increased, resulting in a decrease in the mitochondrial membrane potential. The phosphorylation of GSK3β (Ser9) and anti-apoptotic protein Bcl2 expression levels were significantly downregulated in Prx II knockdown HT22 cells, which suggests that Prx II knockdown HT22 cells were more susceptible to alcohol-induced apoptosis. Scavenging the alcohol-induced ROS with NAC significantly decreased the intracellular ROS levels, as well as the phosphorylation level of GSK3β in Prx II knockdown HT22 cells. Moreover, NAC treatment also dramatically restored the mitochondrial membrane potential and the cellular apoptosis in Prx II knockdown HT22 cells. Our findings suggest that Prx II plays a crucial role in alcohol-induced neuronal cell apoptosis by regulating the cellular ROS levels, especially through regulating the ROS-dependent mitochondrial membrane potential. Consequently, Prx II may be a therapeutic target molecule for alcohol-induced neuronal cell death, which is closely related to ROS-dependent mitochondria dysfunction.

Lipid droplets are unique lipid storage organelles in hepatocytes. Lipophagy is a key mechanism of selective degradation of lipid droplets through lysosomes. It plays a crucial role in the prevention of metabolic liver disease, including nonalcoholic fatty liver disease (NAFLD) and alcoholic fatty liver disease (AFLD), and is a potential therapeutic target for treating these dysfunctions. In this review, we highlighted recent research and discussed advances in key proteins and molecular mechanisms related to lipophagy in liver disease. Reactive oxygen species (ROS) is an inevitable product of metabolism in alcohol-treated or high-fat-treated cells. Under this light, the potential role of ROS in autophagy in lipid droplet removal was initially explored to provide insights into the link between oxidative stress and metabolic liver disease. Subsequently, the current measures and drugs that treat NAFLD and AFLD through lipophagy regulation were summarized. The complexity of molecular mechanisms underlying lipophagy in hepatocytes and the need for further studies for their elucidation, as well as the status and limitations of current therapeutic measures and drugs, were also discussed.

Background: Alterations in the microbiota-gut-brain axis are associated with the onset of autism spectrum disorder (ASD). Numerous studies have reported that the gut microbiota (GM) is significantly altered in individuals with ASD and animal models of ASD. However, few studies have focused on sex-specific differences in the GM and fecal metabolites of ASD. Methods: In this study, we performed 16S rRNA gene sequencing and untargeted metabolomics in parallel on fecal samples from a valproic acid (VPA)-induced rat model of autism (VPA rats). Based on these data, we analyzed differentially abundant metabolites in the Kyoto Encyclopedia of Genes and Genomes (KEGG) database to reveal the possible mechanism of ASD. Data derived from male and female rats were analyzed separately. Finally, we analyzed the correlation between characteristic genera and characteristic fecal metabolites in VPA rats of both sexes. Results: The results showed that VPA rats of both sexes presented remarkable alterations in the GM and fecal metabolites. Sex-specific differences were noticeably detected. We identified 51 annotated differentially abundant fecal metabolites and 1 differentially enriched KEGG pathway between the male VPA and male control groups. Ruminococcus_2, Candidatus_Soleaferrea, Desulfovibrio, Candidatus_Saccharimonas, Intestinimonas, [Eubacterium]_xylanophilum_group, [Eubacterium]_brachy_group and [Bacteroides]_pectinophilus_group were the characteristic genera of male VPA rats. Between the female VPA and female control groups, 124 annotated differentially abundant fecal metabolites were identified without differentially enriched KEGG pathways. Ruminiclostridium, Acetatifactor, Desulfovibrio, [Eubacterium]_xylanophilum_group and Candidatus_Saccharimonas were the characteristic genera of female VPA rats. Correlation analysis revealed a tight relationship between the GM and fecal metabolites in VPA rats of both sexes. Conclusions: In conclusion, alterations in the GM and fecal metabolites in VPA rats showed sex-specific differences. The therapy for ASD might be different between sexes in the future.