Autophagy and apoptosis in liver injury

Arsenic trioxide-induced autophagy affected the antioxidant capacity and apoptosis rate of chicken hepatocytes

Arsenic has recently received widespread attention due to its high toxicological effects on multiple animals; however, the mechanism underlying this toxicity is unclear. We investigated the damaging effects of arsenic trioxide (ATO) on hepatocytes and the effects of regulating autophagy on the hepatocyte damage induced by ATO exposure. First, we investigated the effects of ATO exposure (0, 0.6, 1.2, 2.4, and 4.8 μM) on the biochemical function and autophagy of chicken hepatocytes. The findings showed that as the concentration of ATO increased, the lactate dehydrogenase (LDH) concentration increased, more autophagosomes were observed via transmission electron microscopy (TEM), and the gene and protein expression levels of P62, LC3Ⅱ, and Beclin1 increased. Adding N-acetyl-l-cystine (NAC, 1 mM) attenuated autophagy and the hepatocyte damage induced by ATO. Then, we used rapamycin (Rapa) and 3-methylpurine (3-MA) to regulate the autophagy induced by exposure to 4.8 μM ATO and observed changes in the antioxidant capacity and apoptosis rate of chicken hepatocytes. Induction of autophagy reduced ATO-induced hepatocyte apoptosis but caused no significant effect on oxidative stress in chicken hepatocytes. Inhibition of autophagy exacerbated ATO-induced hepatocyte oxidative stress and apoptosis. These findings demonstrate that autophagy plays an important role in ATO-induced cell damage.

Hypoxia-Inducible Factors and Burn-Associated Acute Kidney Injury-A New Paradigm?

O₂ deprivation induces stress in living cells linked to free-radical accumulation and oxidative stress (OS) development. Hypoxia is established when the overall oxygen pressure is less than 40 mmHg in cells or tissues. However, tissues and cells have different degrees of hypoxia. Hypoxia or low O₂ tension may be present in both physiological (during embryonic development) and pathological circumstances (ischemia, wound healing, and cancer). Meanwhile, the kidneys are major energy-consuming organs, being second only to the heart, with an increased mitochondrial content and O₂ consumption. Furthermore, hypoxia-inducible factors (HIFs) are the key players that orchestrate the mammalian response to hypoxia. HIFs adapt cells to low oxygen concentrations by regulating transcriptional programs involved in erythropoiesis, angiogenesis, and metabolism. On the other hand, one of the life-threatening complications of severe burns is acute kidney injury (AKI). The dreaded functional consequence of AKI is an acute decline in renal function. Taking all these aspects into consideration, the aim of this review is to describe the role and underline the importance of HIFs in the development of AKI in patients with severe burns, because kidney hypoxia is constant in the presence of severe burns, and HIFs are major players in the adaptative response of all tissues to hypoxia.

Autophagy Promotes α-Amanitin-Induced Apoptosis of Hepa1-6 Liver Cells

It is estimated that 90% of deaths from food poisoning in China can be attributed to Amanita poisoning, whose main toxin is α-amanitin. Studies showed that apoptosis plays a critical role in liver injuries induced by α-amanitin. Although the relationship between autophagy and apoptosis in different liver models has been addressed many times, whether autophagy plays a pro or con effect on α-amanitin-induced apoptosis has not been clarified. Therefore, this study was conducted to explore the effect of autophagy in α-amanitin-induced apoptosis in Hepa1-6 liver cells. A 3-[4,5-dimethylthiazol-2-yl]-2,5 diphenyl tetrazolium bromide (MTT) assay was applied to determine cell viability, a 2',7'-dichlorofluorescin diacetate probe was used to monitor reactive oxygen species (ROS) levels, a flow cytometer and dansylcadaverine (MDC) staining were used to observe α-amanitin-induced apoptosis and autophagy, respectively, and apoptosis and autophagy proteins were assessed by western blotting. The results showed that α-amanitin suppressed cell viability in a time- and concentration-dependent manner. Moreover, the release of ROS was increased with increasing α-amanitin amount. Cell apoptosis and autophagy were noticed and characterized by the increased apoptosis rate and autophagic vesicles under a fluorescence microscope as well as upregulation of Bax/Bcl-2, cleaved caspase-3, and LC3-II/I and downregulation of p62. Further, the autophagy activator rapamycin (Rap) and the inhibitor 3-methylademine (3-MA) were introduced, which showed that the apoptosis rate and the ratio of Bax/Bcl-2 as well as the protein expression level of cleaved caspase-3 increased significantly with the pretreatment of Rap and decreased remarkably with the pretreatment of 3-MA. Moreover, cell viability was found to decrease further with the promotion of autophagy. Notably, the ROS level was attenuated after autophagy was elevated. In conclusion, autophagy could promote α-amanitin-induced Hepa1-6 cell apoptosis, and the process is unassociated with ROS levels. This research provides a theoretical basis for the study of the toxicological mechanism of α-amanitin-induced liver injuries.

Possible Cytoprotection of Low Dose Lipopolysaccharide in Rat Thioacetamide-Induced Liver Lesions, Focusing on the Analyses of Hepatic Macrophages and Autophagy

Lipopolysaccharide (LPS) may influence hepatic macrophages and autophagy. We evaluated the potential participation of macrophages and autophagosomes in thioacetamide (TAA)-induced rat liver injury under pretreatment of a low dose LPS (0.1 mg/kg BW, intraperitoneally; nonhepatotoxic dose). F344 rats were pretreated with LPS (LPS + TAA) or saline (TAA alone) at 24 hours before TAA injection (100 mg/kg BW, intraperitoneally); rats were examined on Days 0 (controls), 1, 2, and 3 after TAA injection. Data were compared between TAA alone and LPS + TAA rats. LPS pretreatment significantly reduced TAA-induced hepatic lesion (centrilobular necrosis with inflammation) on Days 1 and 2, being reflected by declined hepatic enzyme values and decreased number of apoptotic cells. LC3B-immunoreacting autophagosomes (as cytoplasmic fine granules) were significantly increased on Days 1 and 2 in hepatocytes of LPS + TAA rats. In LPS + TAA rats, hepatic macrophages reacting to CD68, CD163, and MHC class II mainly on Day 2 and mRNA levels of macrophage-related factors (MCP-1, IL-1β, and IL-4) on Day 1 were significantly decreased. Collectively, the low-dose LPS pretreatment might act as cytoprotection against TAA-induced hepatotoxicity through increased autophagosomes and decreased hepatic macrophages, although the dose/time-dependent cytoprotection of LPS should be further investigated at molecular levels.

Role of Autophagy in Lysophosphatidylcholine-Induced Apoptosis of Mouse Ovarian Granulosa Cells

Lysophosphatidylcholine (LPC), also known as lysolecithin, is one of the major components of oxidized low-density lipoproteins (ox-LDL). In the pathogenetic process of diverse diseases, LPC acts as a significant lipid mediator. However, no evidence shows that LPC can affect the female reproductive system. In our study, we found that LPC inhibited the cell viability of primary mouse ovarian granulosa cells. Meanwhile, LPC was shown to induce apoptosis, which is accompanied by an increase in apoptosis-related protein levels, such as cleaved caspase-3, cleaved caspase-8 and Bax, as well as a decrease in Bcl-2. The total numbers of early and late apoptotic cells also increased in the LPC-treated cells. These results indicated that LPC could induce apoptosis of mouse ovarian granulosa cells. Furthermore, the increase in autophagy-related protein levels and the number of autophagic vesicles suggested that LPC could induce autophagy. The inhibition of oxidative stress by N-acetyl-L-cysteine (NAC) could rescue the induction of apoptosis and autophagy by LPC, which indicated that oxidative stress was involved in LPC-induced apoptosis and autophagy. Interestingly, the inhibition of autophagy by 3-MA could reserve the inhibition of cell viability and the induction of apoptosis by LPC. In conclusion, oxidative stress was involved in LPC-induced apoptosis, whileautophagy of mouse ovarian granulosa cells and the inhibition of autophagy could alleviate LPC-induced apoptosis.

Circular RNA hsa_circ_0001658 regulates apoptosis and autophagy in gastric cancer through microRNA-182/Ras-related protein Rab-10 signaling axis

Gastric cancer (GC) is a tumor with high incidence and lack of early diagnostic markers. The aim of this study was to explore novel regulatory circular RNAs (circRNAs) in GC and their underlying mechanisms. Differentially expressed circRNAs were analyzed using the Gene Expression Omnibus (GEO). mRNA and miRNA expression levels were determined using real-time reverse transcription polymerase chain reaction (RT-qPCR). Protein expression was detected using Western blotting. Cellular functions were evaluated using the cell counting kit-8 (CCK-8) assay and flow cytometry analysis. Immunofluorescence analysis was used to visually identify microtubule-associated protein 1 light chain 3 (LC3) puncta on a per-cell basis. Furthermore, dual-luciferase reporter and RNA pull-down assays were performed to verify the interaction between microRNA (miR)-182 and circ_0001658/Ras-related protein Rab-10 (RAB10). Circ_0001658 was identified to be aberrantly expressed in GC tissues and was demonstrated in GC cell lines (AGS and HGC27) in vitro. MiR-182 bound to circ_0001658 and RAB10. Circ_0001658 and RAB10 were upregulated, whereas miR-182 was suppressed in AGS and HGC27 cells. GC cell viability and autophagy were inhibited and apoptosis was promoted after circ_0001658 knockdown, and the cellular functions were reversed by downregulating miR-182. Moreover, upregulated RAB10 neutralized the effects of miR-182 on cell viability, autophagy, and apoptosis of GC cells. Silencing circ_0001658 restrained cell viability, suppressed autophagy, and promoted apoptosis of GC cells by sponging miR-182 to suppress the expression of RAB10. Therefore, circ_0001658 may be a potential therapeutic target for GC.

Inhibition of FOXO1‑mediated autophagy promotes paclitaxel‑induced apoptosis of MDA‑MB‑231 cells

Triple-negative breast cancer (TNBC) is the most aggressive subtype of breast cancer, and it often becomes resistant to paclitaxel (PTX) therapy. Autophagy plays an important cytoprotective role in PTX-induced tumor cell death, and targeting autophagy has been promising for improving the efficacy of tumor chemotherapy in recent years. The aim of the present study was to clarify the mechanism of PTX inducing autophagy in TNBC cells to provide a potential clinical chemotherapy strategy of PTX for TNBC. The present study reported that PTX induced both apoptosis and autophagy in MDA-MB-231 cells and that inhibition of autophagy promoted apoptotic cell death. Furthermore, it was found that forkhead box transcription factor O1 (FOXO1) enhanced PTX-induced autophagy through a transcriptional activation pattern in MDA-MB-231 cells, which was associated with the downstream target genes autophagy related 5, class III phosphoinositide 3-kinase vacuolar protein sorting 34, autophagy related 4B cysteine peptidase, beclin 1 and microtubule associated protein 1 light chain 3β. Knocking down FOXO1 attenuated the survival of MDA-MB-231 cells in response to PTX treatment. These findings may be beneficial for improving the treatment efficacy of PTX and to develop autophagic targeted therapy for TNBC.

Sestrin2 Overexpression Ameliorates Endoplasmic Reticulum Stress-Induced Apoptosis via Inhibiting mTOR Pathway in HepG2 Cells

Sestrin2 is a highly conserved stress-inducible protein, acting as a crucial part in regulating homeostasis in response to various stress conditions in the cell. However, the role of Sestrin2 in regulating cell apoptosis related to endoplasmic reticulum (ER) has not been fully investigated. Our study presented here aims to reveal the effect of Sestrin2 in tunicamycin (TM)-induced cell apoptosis related to ER stress and its underlying molecular mechanisms. The results demonstrated that Sestrin2 expression was significantly upregulated correlated with ER stress responses in TM treated HepG2 cells. Sestrin2 overexpression obviously alleviated ER stress with the determination of ER stress-related proteins expression. In addition, Sestrin2 overexpression inhibited cell apoptosis with the examination of apoptosis-related proteins and TUNEL assay. However, Sestrin2 knockdown further promoted the ER stress-mediated cell apoptosis. The further mechanistic study revealed that Sestrin2 overexpression inhibited TM-induced mTOR pathway activation. Taken together, our current study indicated that Sestrin2 overexpression ameliorates ER stress-induced apoptosis via inhibiting mTOR pathway in HepG2 cells.

MicroRNA-128b mediates lipopolysaccharide-induced apoptosis via reactive oxygen species in human pulmonary microvascular endothelial cells

OBJECTIVES

This study aimed to explore the effects of miR-128b in the regulation of Lipopolysaccharide (LPS) induced apoptosis.

METHODS

Human Pulmonary Microvascular Endothelial Cells (HPMECs) were transfected with an miR-128b inhibitor and stimulated with LPS for 24 h. FCM was performed to detect apoptosis and Reactive Oxygen Species (ROS) production. In addition, miRNA and caspase-3 expression levels were determined using real-time quantitative polymerase chain reaction and western blotting.

RESULTS

LPS significantly induced apoptosis and ROS production and upregulated miR-128b and caspase-3 expressions in HPMECs. However, LPS-induced effects were suppressed when an miR-128b inhibitor was used. Preincubation with NAC decreased the LPS-induced apoptosis of HPMECs.

CONCLUSIONS

These effects were mediated by miR-128b via the caspase-3 pathway.

Astragalus polysaccharide alleviated hepatocyte senescence via autophagy pathway

Aging is characterized by inevitable organ function decline over time, with consequent body deterioration and increased susceptibility to death. Astragalus polysaccharide (APS) has been reported to have anti-oxidative, anti-apoptotic, and anti-inflammatory properties. We investigated the potential protective effects of APS on hydrogen peroxide (H₂ O₂ ) induced hepatocyte senescence and identified related mechanisms in L02, Huh7, and LM3 cell lines. Aged female C57BL/6 mice were given APS for 1 week by intraperitoneal injection, and APS provided the strongest protective effect against H₂ O₂ -induced damage at 100 μM. APS reduced the expression of cell senescence markers and alleviated pathological damage in aged mouse liver. APS treatment decreased oxidative stress, apoptosis, NOD-like receptor protein-3-mediated pyroptosis, and maintained mitochondrial homeostasis. Notably, the protective effect of APS was weakened in the presence of chloroquine. APS might enrich autophagy by activating AMP-activated protein kinase (AMPK) and inhibiting mammalian target of rapamycin (mTOR). In conclusion, APS reduced reactive oxygen species levels, inhibited apoptosis and pyroptosis, and promoted mitophagy via AMPK/mTOR pathway to alleviate hepatocyte senescence in vitro and in vivo.

20(S)-Ginsenoside Rh2-induced apoptosis and protective autophagy in cervical cancer cells by inhibiting AMPK/mTOR pathway

20(S)-Ginsenoside Rh2 (GRh2) has various biological activities including anticancer effects. However, no reports have investigated the connection between autophagy and apoptosis in HeLa cells treated with 20(S)-GRh2. In this study, we found that 20(S)-GRh2 suppressed proliferation and induced apoptosis in HeLa cells by activating the intrinsic apoptotic pathway and causing mitochondrial dysfunction. 20(S)-GRh2 enhanced cell autophagy through promoting the phosphorylation of AMPK, depressed the phosphorylation of AKT, and suppressed mTOR activity. Furthermore, treatment with the autophagy inhibitor 3-methyladenine (3-MA) enhanced 20(S)-GRh2-induced apoptosis, while the autophagy inducer rapamycin promoted cell survival. Moreover, the apoptosis inhibitor Z-VAD-FMK significantly restrained the apoptosis and autophagy induced by 20(S)-GRh2 in HeLa cells. We found that 20(S)-ginsenoside Rh2-induced protective autophagy promotes apoptosis of cervical cancer cells by inhibiting AMPK/mTOR pathway.

Dysfunction of aged liver of male albino rats and the effect of intermitted fasting; Biochemical, histological, and immunohistochemical study

Intermittent fasting exerts beneficial effects on most age-related degenerative changes throughout the body. This study aimed to investigate the possible protective effects and mechanism of intermittent fasting on aged liver in male albino rats. Forty male albino rats were used in this study and were divided into four equal groups; Group I served as control ; rats aged 1 month sacrfied when they reached age of 4 month. Group II; rats aged 1 month with intermittent fasting for 3 months. The rats sacrfied when they reached age of 4 mounth Group III; rats aged 15-month fed an ad-libitum diet. The rats sacrified when they reached age of 18 month. Group IV; 15 month rats with intermittent fasting for 3 months. The rats sacrified when they reached age of 18 month. Liver specimens were excised and processed for biochemical, histological, and immunohistochemical study. Blood samples were collected for biochemical study. The result showed a significant increase in liver injury, oxidative stress, and inflammatory markers with a marked decrease in the autophagy marker in group III if compared with both group I and II. Additionally, group III showed hepatic vacuolations, cellular filtration, and congestion in both central and portal veins. A highly significant increase in the mean color intensity of positive immunochemical reaction for anti caspase 3 and anti-TNFα as well as a highly significant increase in the surface area fraction of collagen fibers were noticed in group III if compared with group I and II. Interestingly, intermittent fasting (group IV) remarkably reduced the previous alternation that that occurred in group III. It could be concluded that various biochemical, histological, and immunohistochemical alterations were observed in liver rat in group III. Beneficial effects of fasting on these changes were recorded in group IV through its anti-inflammatory, anti-apoptotic effect as well as its effect in modulating autophagy in aged liver cells. This might open the gate for further research and provide a new line for therapeutic intervention in aged liver. These data lead to speculate that sporadic fasting might represent a simple, safe, and inexpensive means to fight the changes occurred in the aged liver.

Identification of a Five Autophagy Subtype-Related Gene Expression Pattern for Improving the Prognosis of Lung Adenocarcinoma

Background: Autophagy plays an important role in lung adenocarcinoma (LUAD). In this study, we aimed to explore the autophagy-related gene (ARG) expression pattern and to identify promising autophagy-related biomarkers to improve the prognosis of LUAD.

Methods: The gene expression profiles and clinical information of LUAD patients were downloaded from the Cancer Genome Atlas (TCGA), and validation cohort information was extracted from the Gene Expression Omnibus database. The Human Autophagy Database (HADb) was used to extract ARGs. Gene expression data were analyzed using the limma package and visualized using the ggplot2 package as well as the pheatmap package in R software. Functional enrichment analysis was also performed for the differentially expressed ARGs (DEARGs). Then, consensus clustering revealed autophagy-related tumor subtypes, and differentially expressed genes (DEGs) were screened according to the subtypes. Next, the univariate Cox and multivariate Cox regression analyses were used to identify independent prognostic ARGs. After overlapping DEGs and the independent prognostic ARGs, the predictive risk model was established and validated. Correlation analyses between ARGs and clinicopathological variables were also explored. Finally, the TIMER and TISIDB databases were used to further explore the correlation analysis between immune cell infiltration levels and the risk score as well as clinicopathological variables in the predictive risk model.

Results: A total of 222 genes from the HADb were identified as ARGs, and 28 of the 222 genes were pooled as DEARGs. The most significant GO term was autophagy (p = 3.05E-07), and KEGG analysis results indicated that 28 DEARGs were significantly enriched in the ErbB signaling pathway (p < 0.001). Then, consensus clustering analysis divided the LUAD into two clusters, and a total of 168 DEGs were identified according to cluster subtypes. Then univariate and multivariate Cox regression analyses were used to identify 12 genes that could serve as independent prognostic indicators. After overlapping 168 DEGs and 12 genes, 10 genes (ATG4A, BAK1, CAPNS1, CCR2, CTSD, EIF2AK3, ITGB1, MBTPS2, SPHK1, ST13) were selected for the further exploration of the prognostic pattern. Survival analysis results indicated that this risk model identified the prognosis (p = 4.379E-10). Combined with the correlation analysis results between ARGs and clinicopathological variables, five ARGs were screened as prognostic genes. Among them, SPHK1 expression levels were positively correlated with CD4⁺ T cells and dendritic cell infiltration levels.

Conclusions: In this study, we constructed a predictive risk model and identified a five autophagy subtype-related gene expression pattern to improve the prognosis of LUAD. Understanding the subtypes of LUAD is helpful to accurately characterize the LUAD and develop personalized treatment.

Toosendanin triggered hepatotoxicity in zebrafish via inflammation, autophagy, and apoptosis pathways

Toosendanin (TSN) is a crucial component from Toosendan Fructus with a promising anti-tumor capacity. It is also the primary suspect hepatotoxic component of Toosendan Fructus. However, the mechanisms underlying TSN-induced liver injury are still largely unknown. In present study, we evaluated the hepatotoxicity of TSN on zebrafish and explored the role of inflammation, autophagy, and apoptosis in TSN-induced hepatotoxicity. We found that TSN treatment decreased the area and fluorescence intensity of zebrafish liver in time- and dose-dependent manners at nonlethal concentrations. The ALT and AST activities were increased after TSN treatment. Severe cytoplasmic vacuolation and nuclear shrank were found in the liver of TSN-treated zebrafish. The expression profile of genes demonstrated that inflammation, autophagy and apoptosis pathways were involved in TSN-induced hepatotoxicity. Our study demonstrated for the first time that TSN treatment gave rise to liver injury in zebrafish, and inflammation, autophagy, apoptosis played a role in TSN-induced hepatotoxicity.

miR-4486 reverses cisplatin-resistance of colon cancer cells via targeting ATG7 to inhibiting autophagy

Cisplatin (DDP) resistance is one of the main causes of treatment failure in patients with colon cancer (CC). Autophagy is a key mechanism of resistance to chemotherapy. Since autophagy-related 7 (ATG7) has been reported to be involved in the regulation of autophagy and DDP resistance for lung and esophageal cancer, the present study aimed to explore the functions of microRNA (miR)-4486 in the autophagy-mediated DDP resistance of CC. The expression level of miR-4486 in HCT116, DDP-resistant HCT116 cells (HCT116/DDP), SW480 and DDP-resistant SW480 cells (SW480/DDP) was quantified by reverse transcription-quantitative PCR. Western blotting was utilized to analyze the expression of ATG7, autophagy-related proteins Beclin 1 and LC3-I/II, as well as apoptosis-related proteins Bcl-2, Bax and cleaved-caspase 3 in HCT116/DDP and SW480/DDP cells. The half maximal inhibitory concentration of DDP on all cell lines and the cell viability of HCT116/DDP and SW480/DDP cells were measured using Cell Counting Kit 8 assay. Luciferase assay was used to examine the potential targets of miR-4486 and ATG7. The effects of upregulating mimic miR-4486 expression on the apoptosis and autophagy of HCT116/DDP and SW480/DDP cells were determined by flow cytometry and electron microscopy, respectively. It was found that miR-4486 expression was significantly decreased in HCT116/DDP and SW480/DDP cells compared with that in HCT116 and SW480 cells. Overexpression of miR-4486 could increase the sensitivity of HCT116/DDP and SW480/DDP cells to DDP by reducing cell viability, promoting apoptosis and inhibiting autophagy through downregulating Beclin 1 expression and the LC3-II/LC3-I ratio. Additionally, ATG7 was identified to be a target gene of miR-4486, where ATG7 overexpression could partially reverse the effects of miR-4486 on cell viability and apoptosis by promoting the formation of autophagosomes. In conclusion, the present results demonstrated that miR-4486 could reverse DDP resistance in HCT116/DDP and SW480/DDP cells by targeting ATG7 to inhibit autophagy.

Ginsenoside Rb1 alleviates liver injury induced by 3-chloro-1,2-propanediol by stimulating autophagic flux

In recent years, foodborne pollutants have become a hot issue in the field of food safety. 3-chloro-1,2-propanediol (3-MCPD) is a widely existing food contaminant. In our previous study, it was confirmed that 3-MCPD can block autophagic flux by inhibiting lysosomal function, thus causing liver injury. Ginseng is a traditional Chinese herbal medicine that contains a variety of bioactive ingredients, among which ginsenoside Rb1 (Gs-Rb1) is the most abundant. In this study, we aim to use Gs-Rb1 to improve 3-MCPD-induced autophagic flux blockage to alleviate liver injury. First, a nontoxic dose of Gs-Rb1 was identified by screening with the MTT method in which Gs-Rb1was added to HepG2 cells and co-treated with 3-MCPD. We found that Gs-Rb1 effectively enhanced the cell activity inhibited by 3-MCPD. Meanwhile, apoptosis data showed that Gs-Rb1 significantly alleviated the apoptosis of HepG2 cells induced by 3-MCPD. Subsequently, we found that Gs-Rb1 could alleviate autophagic flux blockage caused by 3-MCPD in a dose-dependent manner by detecting autophagy-related protein levels and transfecting mRFP-GFP-LC3 adenovirus. On this basis, we used Western blotting and qPCR to explore whether miR-128 was involved in the alleviation effect of Gs-Rb1 on autophagic flux blockade induced by 3-MCPD. The results showed that Gs-Rb1 inhibited the expression of miR-128 and promoted the nuclear expression and target gene transcription of TFEB. Finally, the findings were confirmed by using a hsa-miR-128 inhibitor and mimic. We found that hsa-miR-128 inhibitor alleviated the autophagic flux blockage and apoptosis caused by 3-MCPD and Gs-Rb1 also had a certain alleviation effect on the autophagic flux blockage and apoptosis caused by hsa-miR-128 mimic. This study elaborated the mechanism by which Gs-Rb1 alleviates hepatotoxicity induced by foodborne 3-MCPD by stimulating autophagic flux via miR-128-targeted TFEB, which provides a reliable theoretical basis and target for the use of natural substances to reduce the harm of food processing pollutants on the human body. PRACTICAL APPLICATION: We found that natural ginsenoside Rb1 can alleviate liver injury induced by 3-MCPD(a toxic substance found in foods such as refined vegetable oil, soy sauce, and baby milk powder), which is conducive to the development and utilization of ginseng and has practical significance for the prevention of foodborne liver injury.

Toxicity and Functional Tissue Responses of Two Freshwater Fish after Exposure to Polystyrene Microplastics

Microplastics (MPs)' ingestion has been demonstrated in several aquatic organisms. This process may facilitate the hydrophobic waterborne pollutants or chemical additives transfer to biota. In the present study the suitability of a battery of biomarkers on oxidative stress, physiology, tissue function and metabolic profile was investigated for the early detection of adverse effects of 21-day exposure to polystyrene microplastics (PS-MPs, sized 5-12 μm) in the liver and gills of zebrafish Danio rerio and perch, Perca fluviatilis, both of which are freshwater fish species. An optical volume map representation of the zebrafish gill by Raman spectroscopy depicted 5 μm diameter PS-MP dispersed in the gill tissue. Concentrations of PS-MPs close to the EC50 of each fish affected fish physiology in all tissues studied. Increased levels of biomarkers of oxidative damage in exposed fish in relation to controls were observed, as well as activation of apoptosis and autophagy processes. Malondialdehyde (MDA), protein carbonyls and DNA damage responses differed with regard to the sensitivity of each tissue of each fish. In the toxicity cascade gills seemed to be more liable to respond to PS-MPs than liver for the majority of the parameters measured. DNA damage was the most susceptible biomarker exhibiting greater response in the liver of both species. The interaction between MPs and cellular components provoked metabolic alterations in the tissues studied, affecting mainly amino acids, nitrogen and energy metabolism. Toxicity was species and tissue specific, with specific biomarkers responding differently in gills and in liver. The fish species that seemed to be more susceptible to MPs at the conditions studied, was P. fluviatilis compared to D. rerio. The current findings add to a holistic approach for the identification of small sized PS-MPs' biological effects in fish, thus aiming to provide evidence regarding PS-MPs' environmental impact on wild fish populations and food safety and adequacy.

Salvianolic acid B improves autophagic dysfunction and decreases the apoptosis of cholesterol crystal‑induced macrophages via inhibiting the Akt/mTOR signaling pathway

Progressive macrophage dysfunction and apoptosis are some of the major events that occur during atherogenesis. To further investigate the intrinsic association between atherosclerosis (AS) and macrophage apoptosis and autophagy, cholesterol crystals (CHCs) were used to stimulate RAW264.7 macrophages to establish a macrophage model of advanced AS. Cells in the CHC group were treated with salvianolic acid B (Sal B) to evaluate its protective effects and reveal its underlying molecular mechanism. The results demonstrated that treatments with Sal B significantly improved autophagy dysfunction and reduced the apoptotic rate of CHC‑induced macrophages. Furthermore, Sal B significantly attenuated CHC‑induced release of proinflammatory factors (TNF‑α and IL‑6) by macrophages. Treatment of macrophages with a specific inhibitor of autophagy (3‑methyladenine) significantly reversed Sal B‑mediated effects on autophagy, suggesting that Sal B‑induced autophagy may display a protective effect in CHC‑induced macrophages. Furthermore, pretreatment of CHC‑induced macrophages with insulin significantly decreased Sal B‑induced autophagy, indicating that the Akt/mTOR signaling pathway may serve as a critical mediator in regulating Sal B‑mediated cell death. Taken together, the present study demonstrated that Sal B improved autophagic dysfunction and reduced the apoptosis of CHC‑induced macrophages via inhibiting the Akt/mTOR signaling pathway.

Fluoride regulates chondrocyte proliferation and autophagy via PI3K/AKT/mTOR signaling pathway

Fluorine is an essential trace element for human health. However, excessive fluoride intake causes skeletal fluorosis which affects cartilage development. Fluoride inhibited chondrocyte proliferation which is the initial and critical step of endochondral ossification, but the underlying mechanism has not been clearly illustrated. Mammalian target of rapamycin (mTOR) is an important protein kinase which modulates various cellular processes and is believed to be a central regulator of chondrocyte proliferation and autophagy. In this study, we explored the effect of fluoride on the proliferation and autophagy of chondrocytes and the regulatory role of mTOR signaling pathway. Our results suggested that NaF inhibited the protein expressions of proliferating cell nuclear antigen (PCNA) and pS6 in cultured fetal rat tibias. Furthermore, NaF significantly downregulated the expressions of mTOR signaling pathway-related genes, including PI3K, AKT, mTOR, 4EBP1 and S6K1 in mouse ATDC5 chondrogenic cell line. We also found that NaF increased autophagy in ATDC5 cells. The mRNA and protein levels of autophagy-related genes LC3, Beclin1 and p62 were significantly changed after NaF treatment. Further studies demonstrated that MHY1485, a small-molecular mTOR activator, totally reversed fluoride-induced promotion of autophagy. MHY1485 also recovered the downregulation of proliferative chondrocytes markers Sox9 and Type Ⅱ Collagen (Col2a1) induced by fluoride in ATDC5 cells. Taken together, our result demonstrate that fluoride suppressed proliferation and facilitated autophagy via PI3K/AKT/mTOR signaling pathway in chondrogenesis.

Impaired placental mitophagy and oxidative stress are associated with dysregulated BNIP3 in preeclampsia

Preeclampsia (PE) is a severe multisystem pregnancy complication characterized by gestational hypertension and proteinuria. Bcl-2/adenovirus E1B 19-kDa interacting protein 3 (BNIP3) is a mediator of mitophagy and has been proven to be associated with PE, but the mechanism is not well understood. This study aimed to investigate the role of BNIP3 in PE. Placentae from preeclamptic and normal pregnancies were analyzed by western-blot and transmission electron microscopy to quantify the level of BNIP3 expression and observe the organelle morphologies. Trophoblast cells with knockdown BNIP3 were analyzed by western-blot, immunofluorescence, flow cytometry, migration and invasion assays. BNIP3 expression was suppressed in PE patients. Impaired autophagy and increased mitochondrial damage were observed in PE placentae when compared with normal placentae. Suppression of BNIP3 inhibited Beclin-1 expression and reduced the transformation of LC3-I to LC3-II. In the knockdown BNIP3 group, p62 was overexpressed, ROS accumulated and the apoptotic process was elevated under oxidative stress condition. The knockdown of BNIP3 reduced the colocalization of GFP-LC3 and mitochondria. The findings of this study suggest that dysregulated BNIP3 is associated with impaired mitophagy, oxidative stress, and apoptosis in PE. The study provides new insights into the role of BNIP3 in the pathophysiology of PE.

An Autophagy-Related Gene-Based Prognostic Risk Signature for Hepatocellular Carcinoma: Construction and Validation

BACKGROUND

Hepatocellular carcinoma (HCC) is a prevalent primary liver cancer. Treatment is dramatically difficult due to its high complexity and poor prognosis. Due to the disclosed dual functions of autophagy in cancer development, understanding autophagy-related genes devotes into novel biomarkers for HCC.

METHODS

Differential expression of genes in normal and tumor groups was analyzed to acquire autophagy-related genes in HCC. These genes were subjected to GO and KEGG pathway analyses. Genes were then screened by univariate regression analysis. The screened genes were subjected to multivariate Cox regression analysis to build a prognostic model. The model was validated by the ICGC validation set.

RESULTS

To sum up, 42 differential genes relevant to autophagy were screened by differential expression analysis. Enrichment analysis showed that they were mainly enriched in pathways including regulation of autophagy and cell apoptosis. Genes were screened by univariate analysis and multivariate Cox regression analysis to build a prognostic model. The model constituted 6 feature genes: EIF2S1, BIRC5, SQSTM1, ATG7, HDAC1, and FKBP1A. Validation confirmed the accuracy and independence of this model in predicting the HCC patient's prognosis.

CONCLUSION

A total of 6 feature genes were identified to build a prognostic risk model. This model is conducive to investigating interplay between autophagy-related genes and HCC prognosis.

Autophagic degradation of IRF3 induced by the small-molecule auranofin inhibits its transcriptional and proapoptotic activities

The ubiquitously expressed transcription factor interferon (IFN) regulatory factor 3 (IRF3) is critical for the induction of antiviral genes, e.g., type-I IFN. In addition to its transcriptional function, IRF3 also activates a nontranscriptional, proapoptotic signaling pathway. While the proapoptotic function of IRF3 protects against viral infections, it is also involved in harmful immune responses that trigger hepatocyte cell death and promote liver disease. Thus, we hypothesized that a small-molecule inhibitor of the proapoptotic activity of IRF3 could alleviate fatty-acid-induced hepatocyte cell death. We conducted a high-throughput screen, which identified auranofin as a small-molecule inhibitor of the proapoptotic activity of IRF3. In addition to the nontranscriptional apoptotic pathway, auranofin also inhibited the transcriptional activity of IRF3. Using biochemical and genetic tools in human and mouse cells, we uncovered a novel mechanism of action for auranofin, in which it induces cellular autophagy to degrade IRF3 protein, thereby suppressing IRF3 functions. Autophagy-deficient cells were unable to degrade IRF3 upon auranofin treatment, suggesting that the autophagic degradation of IRF3 is a novel approach to regulate IRF3 activities. Using a physiologically relevant in vitro model, we demonstrated that auranofin inhibited fatty-acid-induced apoptotic cell death of hepatocytes. In summary, auranofin is a novel inhibitor of IRF3 functions and may represent a potential therapeutic option in diseases where IRF3 is deleterious.

Evaluation of toxic effects induced by arsenic trioxide or/and antimony on autophagy and apoptosis in testis of adult mice

Arsenic trioxide (ATO) and antimony (Sb) are well-known ubiquitous environmental contaminants and cause unpromising male reproductive effects in target and non-target exposed organisms. The main objective of this study was to investigate the effects of ATO or/and Sb on process of autophagy, apoptosis, and reproductive organ in adult mice. For this reason, a total of 32 adult mice were randomly divided into different groups like control group, ATO-treated group, Sb-treated group, and combined group. The duration of current experimental trial was 2 months. Various adverse effects of ATO or/and Sb on sperm parameters, oxidative stress, autophagy, and apoptosis were determined in testis of mice. Results indicated that parameters of sperm quality for organ coefficient, sperm count, ratio of sperm survival, testosterone level, and germ cells were significantly decreased, while malformation rate and vacuolization significantly increased in mice exposed to different treatments. Furthermore, the status of antioxidant index of T-AOC, SOD, and MsrB1 levels was reduced, while MDA increased significantly in ATO + Sb group. Results on TEM investigation determined that the autophagosomes, autolysosome, nuclear pyknosis, and chromatin condensation were prominent ailments, and the levels of autophagy and pro-apoptosis indictors including Beclin1, Atg-5, LC3B/LC3A, caspase-8, cytc, cleaved caspase-3, p53, and Bax were up-regulated in treated group, while the content of an anti-apoptosis maker (Bcl-2) was down-regulated. In conclusion, the results of our experiment suggested that abnormal process of autophagy and apoptosis was triggered by arsenic and antimony, and intensity of toxic effects increased in combined treatments of ATO and Sb.

PLK1 (polo like kinase 1)-dependent autophagy facilitates gefitinib-induced hepatotoxicity by degrading COX6A1 (cytochrome c oxidase subunit 6A1)

Liver dysfunction is an outstanding dose-limiting toxicity of gefitinib, an EGFR (epidermal growth factor receptor)-tyrosine kinase inhibitor (TKI), in the treatment of EGFR mutation-positive non-small cell lung cancer (NSCLC). We aimed to elucidate the mechanisms underlying gefitinib-induced hepatotoxicity, and provide potentially effective intervention strategy. We discovered that gefitinib could sequentially activate macroautophagy/autophagy and apoptosis in hepatocytes. The inhibition of autophagy alleviated gefitinib-induced apoptosis, whereas the suppression of apoptosis failed to lessen gefitinib-induced autophagy. Moreover, liver-specific Atg7+/- heterozygous mice showed less severe liver injury than vehicle, suggesting that autophagy is involved in the gefitinib-promoted hepatotoxicity. Mechanistically, gefitinib selectively degrades the important anti-apoptosis factor COX6A1 (cytochrome c oxidase subunit 6A1) in the autophagy-lysosome pathway. The gefitinib-induced COX6A1 reduction impairs mitochondrial respiratory chain complex IV (RCC IV) function, which in turn activates apoptosis, hence causing liver injury. Notably, this autophagy-promoted apoptosis is dependent on PLK1 (polo like kinase 1). Both AAV8-mediated Plk1 knockdown and PLK1 inhibitor BI-2536 could mitigate the gefitinib-induced hepatotoxicity in vivo by abrogating the autophagic degradation of the COX6A1 protein. In addition, PLK1 inhibition could not compromise the anti-cancer activity of gefitinib. In conclusion, our findings reveal the gefitinib-hepatotoxicity pathway, wherein autophagy promotes apoptosis through COX6A1 degradation, and highlight pharmacological inhibition of PLK1 as an attractive therapeutic approach toward improving the safety of gefitinib-based cancer therapy.Abbreviations: 3-MA: 3-methyladenine; AAV8: adeno-associated virus serotype 8; ATG5: autophagy related 5; ATG7: autophagy related 7; B2M: beta-2-microglobulin; CCCP: carbonyl cyanide m-chlorophenylhydrazone; CHX: cycloheximide; COX6A1: cytochrome c oxidase subunit 6A1; c-PARP: cleaved poly(ADP-ribose) polymerase; CQ: chloroquine; GOT1/AST: glutamic-oxaloacetic transaminase 1, soluble; GPT/ALT: glutamic pyruvic transaminase, soluble; HBSS: Hanks´ balanced salt solution; H&E: hematoxylin and eosin; MAP1LC3/LC3: microtubule associated proteins 1 light chain 3; PLK1: polo like kinase 1; RCC IV: respiratory chain complex IV; ROS: reactive oxygen species; TUBB8: tubulin beta 8 class VIII.

Ononin alleviates H2O2-induced cardiomyocyte apoptosis and improves cardiac function by activating the AMPK/mTOR/autophagy pathway

Ononin (ON) is an isoflavone with numerous reported bioactivities, including anti-oxidative, anti-inflammatory and neuroprotective effects. Autophagy is a critical homeostatic process in the body that has been reported to closely associate with the apoptotic processes of cardiomyocytes. Using flow cytometry, western blotting, echocardiography and Masson's staining, the present study investigated the effects of ON on H₂O₂-induced cardiomyocyte apoptosis and myocardial infarction, in addition to any potential underlying molecular mechanisms. H₂O₂ treatment reliably induced apoptosis in H9C2 cells. The anti-apoptotic effects of ON were revealed by flow cytometry results and by the downregulation of cleaved-caspase 3. Further investigations indicated that ON may alleviate apoptosis by enhancing autophagy, as evidenced by increased microtubule-associated proteins 1A/1B light chain 3B expression and p62 degradation. Activation of the 5' AMP-activated protein kinase (AMPK)/mTOR pathway was observed after ON administration following H₂O₂-induced cardiomyocyte injury. However, these anti-apoptotic effects mediated by ON were lost after autophagy inhibition by chloroquine or AMPK inhibition by Compound C. Finally, the protective effects of ON on cardiomyocytes in vitro could also be observed in vivo. A myocardial infarction model was established by ligating the left anterior descending branch of the rat heart. Using echocardiography and Masson's staining, ON was shown to increase the ejection fraction and decrease cardiac fibrosis in rats with myocardial infarction. These results suggest that ON exerts cardioprotective effects by improving autophagy via the AMPK/mTOR signaling pathway.

Liquiritigenin protects against arsenic trioxide-induced liver injury by inhibiting oxidative stress and enhancing mTOR-mediated autophagy

Liquiritigenin (LQ) has protective effects against various hepatotoxicities. However, its specific role on arsenic trioxide (ATO)-induced hepatotoxicity and the related biomolecular mechanisms remain unclear. The purpose of this study is to explore the protective actions of LQ on ATO-induced hepatotoxicity and its biomolecular mechanisms in mice. LQ was administered orally at 20 and 40 mg/kg per day for seven consecutive days with an intraperitoneal injection of ATO (5 mg/kg). Liver injury was induced by ATO and was alleviated by treatment with LQ as reflected by reduced histopathological damage of liver and decreased serum ALT, AST, and ALP levels. The generation of intracellular ROS induced by ATO was attenuated after LQ treatment. The levels of SOD, CAT, and GSH were elevated with LQ administration while MDA levels decreased. LQ mitigated elevated TNF-α and IL-6 levels as well as the hepatic mitochondrial damage caused by ATO. Moreover, LQ upregulated the expression of LC3-II and enhanced autophagy in the liver of ATO-induced mice. Further studies indicated that LQ significantly suppressed the expression of p-PI3K, p-AKT, and p-mTOR in ATO-induced mice. In conclusion, our findings show that LQ protects against ATO-induced hepatotoxicity due to its antioxidant and anti-inflammatory activities and enhancement of autophagy mediated by the PI3K/AKT/mTOR signaling pathway in mice.

Huganbuzure Granule Attenuates Concanavalin-A-Induced Immune Liver Injury in Mice via Regulating the Balance of Th1/Th2/Th17/Treg Cells and Inhibiting Apoptosis

In Uygur medicine, Huganbuzure granule (HBG) is one of the classical prescriptions for liver protection. However, its role in immune liver injury remains unknown. This study evaluates the effect of HBG on concanavalin-A- (ConA-) induced immune liver injury and investigates its protective underlying mechanism. BALB/c mice were randomly divided into five groups (n = 24 mice per group): control, ConA, 1.6 g/kg HBG + ConA, 3.2 g/kg HBG + ConA, and 6 mg/kg prednisolone + ConA. HBG was intragastrically administrated once daily for ten consecutive days, prior to ConA (20 mg/kg) injection. The levels of alanine aminotransferase (ALT), aspartate aminotransferase (AST), total bilirubin (TBIL), superoxide dismutase (SOD), and malondialdehyde (MDA) in mouse serum were measured after ConA injection. Moreover, liver-related mRNA levels were evaluated by qPCR. The detection of liver-related proteins was assessed by immunohistochemistry and western blot analysis. Compared with the ConA group, HBG reduced the mRNA expression of IL-17A and IFN-γ and the protein expression of T-bet and ROR-γt. In addition, HBG increased the mRNA expression of IL-4 and TGF-β and protein expression of GATA3 and Foxp3, indicating that HBG regulated the balance of Th1/Th2 and Th17/Treg. Furthermore, HBG alleviated immune liver injury by reducing oxidative stress, inhibiting apoptosis, and decreasing the expression of p-JNK, p-ERK, p-p38, p-JAK1, p-STAT1, p-STAT3, and IRF1. Our data suggested that HBG attenuated ConA-induced immune liver injury by regulating the immune balance and inhibiting JAK1/STATs/IRF1 signaling, thereby reducing apoptosis induced by JNK activation. The findings indicate that HBG may be a promising drug for immune liver injury.

Inhibition of endoplasmic reticulum stress-related autophagy attenuates MCLR-induced apoptosis in zebrafish testis and mouse TM4 cells

Microcystin-leucine arginine (MCLR), a widespread environmental contaminant produced by cyanobacteria, poses a severe threat to the male reproductive system. However, the mechanisms of MCLR-induced testis injury accompanied by autophagy are still obscure. This study aimed to investigate the effects of MCLR on autophagy and apoptosis on the male reproductive system and its mechanism both in vitro and in vivo. MCLR caused damage to the testis of zebrafish, resulting in decreased hatching and growth retardation in the offspring. It also remarkably enhanced autophagic flux by elevating the expression of LC3BII, ATG5, and ATG12 proteins. The autophagic flux was also confirmed through the formation of autophagosomes in the ultrastructure of the zebrafish testis and the accumulation of LC3-positive puncta in zebrafish testis and mouse TM4 cells. Further evaluations revealed that inhibition of autophagy by 3-methyladenine (3-MA) significantly attenuated MCLR-induced apoptosis. This finding indicated that autophagy plays an essential role in cell death in the male reproductive system. Besides, inhibiting endoplasmic reticulum (ER) stress using 4-phenylbutyrate (4-PBA) remarkably blocked autophagy and partially suppressed apoptosis in TM4 cells induced by MCLR. This phenomenon suggested that ER stress-related autophagy was involved in MCLR-induced apoptosis. This study reveals crosstalk between ER stress and autophagy via the PERK/eIF2α/ATF4 signaling pathway. It further suggests that ER stress-related autophagy contributes to MCLR-induced apoptosis and injury in the male reproductive system. These findings provide a novel insight into MCLR-induced impairments of the testis.

Fucoidan as an Autophagy Regulator: Mechanisms and Therapeutic Potentials for Cancer and Other Diseases

Fucoidan, a natural polysaccharide with a variety of classical bioactivities mainly sourced from brown algae, has been extensively studied owing to its favorable pharmacological effects, including anti-inflammatory, anti-tumor, anticoagulant and liver protection. Recently it has been found to play a regulatory role in the processes of autophagy. Autophagy is an important cellular process that effectively protects cells and organisms from stimulating factors such as nutrient deficiency, low cellular ATP levels, metabolic stress, growth factor deprivation and hypoxic conditions. In recent years, many studies have shown that fucoidan can treat human diseases by regulating autophagy process though cell signaling pathways. In this review, we summarize the latest progress in the discovery of natural autophagy regulator of fucoidan for the therapeutic application in cardiac diseases, cancers and liver diseases, aiming to provide the new pharmacological application that fucoidan may treat human diseases by regulating autophagy. Furthermore, we look forward to seeing more diseases that would be treated by autophagy modulator of fucoidan and the discovery of more elaborate autophagy regulation mechanism.

Berberine-loaded nanostructured lipid carriers mitigate warm hepatic ischemia/reperfusion-induced lesion through modulation of HMGB1/TLR4/NF-κB signaling and autophagy

OBJECTIVE

Berberine (BBR) is a known alkaloid that has verified its protective effects against ischemia/reperfusion (I/RN) lesion in multiple organs but its poor oral bioavailability limited its use. Despite the previous works, its possible impact on the warm hepatic I/RN-induced lesion is not clear. Accordingly, a nanostructured lipid carrier of BBR (NLC BBR) was developed for enhancing its efficiency and to inspect its protective mechanistic against warm hepatic I/RN.

METHODS

NLC BBR formula was evaluated pharmaceutically. Wistar rats were orally pre-treated with either BBR or NLC BBR (100 mg/kg) for 2 weeks followed by hepatic I/RN (30 min/24 h). Biochemical, ELISA, qPCR, western blot, histopathological, and immunohistochemical studies were performed.

KEY FINDINGS

Optimized NLC BBR was prepared with a particle size of 130 ± 8.3 nm. NLC BBR divulged its aptitude to safeguard the hepatic tissues partly due to anti-inflammatory capacity through downsizing the HMGB1/TLR4/NF-κB trajectory with concomitant rebating of TNF-α, iNOS, COX-2, and MPO content. Furthermore, NLC BBR antiapoptotic trait was confirmed by boosting the prosurvival protein (Bcl-2) and cutting down the pro-apoptotic marker (Bax). Moreover, its antioxidant nature was confirmed by TAC uplifting besides MDA subsiding. On the other hand, NLC BBR action embroiled autophagy flux spiking merit exemplified in Beclin-1 and LC3-II enhancement. Finally, NLC BBR administration ascertained its hepatocyte guarding action by recovering the histopathological ailment and diminishing serum transaminases.

CONCLUSION

NLC BBR purveyed reasonable shielding mechanisms and subsided incidents contemporaneous to warm hepatic I/RN lesion in part, by moderating HMGB1/TLR4/NF-κB inflammatory signaling, autophagy, and apoptosis.

Isoflurane induces liver injury by modulating the expression of miR-125a-5p

BACKGROUND

Isoflurane can cause hepatotoxicity, and microRNAs (miRNAs) are involved in the regulation of liver injury. Therefore, this study aimed to explore the effect of miR-125a-5p on isoflurane-induced liver injury.

BASIC PROCEDURES

Sprague-Dawley (SD) male rats and BRL-3A cells were exposed to isoflurane to construct animal and cell models. Serum alanine transaminase (ALT) and aspartate transaminase (AST) levels of rats were detected. RT-qPCR was performed for the measurement of miR-125a-5p levels. Cell proliferation and apoptosis were also detected.

MAIN FINDINGS

After isoflurane treatment, serum ALT and AST levels of rats increased in a time-dependent manner, and the differences reached significant levels from 3 days after isoflurane treatment. MiR-125a-5p levels increased significantly in the liver tissues of isoflurane-treated rats. MiR-125a-5p downregulation significantly attenuated isoflurane-induced increasing trend of serum ALT and AST levels in rats. In BRL-3A cells, isoflurane treatment significantly inhibited cell proliferation and promoted cell apoptosis, which was reversed by miR-125a-5p downregulation.

PRINCIPAL CONCLUSIONS

Isoflurane exposure significantly elevates the level of miR-125a-5p in the liver tissues of rats. Downregulation of miR-125a-5p may protect against isoflurane-induced liver injury through regulating liver cell proliferation and apoptosis. Dysregulation of miR-125a-5p might be a possible mechanism of isoflurane-induced liver injury.

The effects of mTOR or Vps34-mediated autophagy on methylmercury-induced neuronal apoptosis in rat cerebral cortex

Methylmercury (MeHg) is a environmental contaminant, which can induce neurotoxic effects. So far, the exact molecular mechanisms of autophagy and its effect on apoptosis in MeHg-induced neurotoxicity have not been elucidated. Here, rats were exposed to MeHg (4, 8, or 12 μmol/kg) for 4 weeks to evaluate the dose-effect relationship between MeHg and apoptosis, or autophagy in cerebral cortex. On this basis, rapamycin (Rapa) or 3-methyladenine (3-MA) was administrated to further explore the regulatory mechanisms of autophagy on MeHg-induced neuronal apoptosis. The pathological changes, autophagy or apoptosis levels, expression of autophagic or apoptotic-associated factors such as mTOR, S6K1, 4EBP1, Vps34, Beclin1, p62, LC3, Bcl-2/Bax, caspase, or MAPKs were investigated. Results showed that MeHg dose-dependently induced pathological changes in cerebral cortex, and the levels of autophagy and apoptosis were increased. Furthermore, Rapa pretreatment antagonized MeHg-induced apoptosis, whereas 3-MA further aggravated apoptosis, which were supported by findings that Rapa activated mTOR-mediated autophagy while 3-MA inhibited Vps34-related autophagy, further affect neuronal apoptosis through regulation of apoptotic factors mentioned above. In conclusion, the findings indicated that MeHg dose-dependently induced autophagy or apoptosis, and mTOR or Vps34 may play important roles in mediating autophagy, which further regulated apoptosis through MAPKs or mitochondrial apoptosis pathways.

Combined effects of hyperthermia and chemotherapy on the regulate autophagy of oral squamous cell carcinoma cells under a hypoxic microenvironment

Autophagy has a complex dual role in tumor survival or cell death owning to that is an evolutionarily conserved catabolic mechanism and provides the cells with a sustainable source of biomolecules and energy for the maintenance of homeostasis under stressful conditions such as tumor microenvironment. Hyperthermia is a rapidly growing field in cancer therapy and many advances have been made in understanding and applying the mechanisms of hyperthermia. The shallow oral and maxillofacial position and its abundant blood supply are favorable for the use of hyperthermia. However, the relationship between hyperthermia and autophagy has not been examined of oral squamous cell carcinoma (OSCC) in the tumor hypoxia microenvironment. Here, the expression level of autophagy relative genes is examined to explore autophagy effect on the responses of hyperthermia, hypoxia, and innutrition tumor microenvironment. It is founded that hyperthermia and hypoxia cause autophagy in starvation conditions; further, in hypoxia and innutrition tumor microenvironment, hyperthermia combines YC-1 and 3-MA could inhibit HIF-1α/BNIP3/Beclin1 signal pathway and decrease the secretion of HMGB1; moreover, the cell apoptosis rate increases with an inhibited of cell migration capacity. Thus, the present study demonstrated that combined use of YC-1 and 3-MA might increase the death of tumor cells in physiological and hyperthermic conditions, which could be relevant with the inhibition of autophagy in OSCC tumor cells under hypoxia microenvironment in vitro, which offers new insight into the therapy of OSCC and its application in treating others study carcinomas.

Saikosaponin D Inhibits the Proliferation and Promotes the Apoptosis of Rat Hepatic Stellate Cells by Inducing Autophagosome Formation

Objective

This study aimed to investigate the effects of saikosaponin D (SSd) on the proliferation and apoptosis of the HSC-T6 hepatic stellate cell line and determine the key pathway that mediates SSd's function.

Methods

Cell viability was detected using the CCK-8 kit. The EdU kit and flow cytometry were used to examine cell proliferation. The Annexin V-FITC/PI double staining kit and flow cytometry were used to examine cell apoptosis. Western blot analysis was performed to analyze the expression levels of LC3, Ki67, cleaved caspase 3, Bax, and Bcl2. Autophagosome formation was detected by LC3-GFP adenovirus transfection.

Results

SSd inhibits the proliferation and promotes the apoptosis of acetaldehyde-activated HSC-T6 cells. SSd treatment increased the expression of cleaved caspase 3 and Bax but reduced that of Ki67 and Bcl2. The same concentration of SSd barely influenced the growth of normal rat liver BRL-3A cells. SSd upregulated LC3-II expression and induced autophagosome formation. Autophagy agonist rapamycin had the same effect as SSd and autophagy inhibitor 3-methyladenine could neutralize the effect of SSd in acetaldehyde-activated HSC-T6 cells.

Conclusions

SSd could inhibit the proliferation and promote the apoptosis of HSC-T6 cells by inducing autophagosome formation.

[Lysosomal membrane protein Sidt2 deletion impairs autophagy in human hepatocytes]

OBJECTIVE

To study the effect of lysosomal membrane protein Sidt2 deletion on autophagy in human hepatocytes.

METHODS

Crispr-Cas9 technology was used to construct a human hepatocyte (HL7702) model of Sidt2 knockout (Sidt2-/-), and the expression levels of the key autophagy proteins LC3II/I, P62 and autophagy-related proteins Atg5, Atg7, and Atg12 were detected.The co-localization of LC3B and P62 in the cells were analyzed with immunofluorescence assay to assess the identification and storage of P62 cargo proteins by the autophagosomes and the degradation of the autophagolysosomes.The co-localization of LC3B and LAMP1 was also determined with immunofluorescence assay to detect the fusion of the autophagosomes with the lysosomes, and LysoTracker was used to trace the acidic lysosomes.

RESULTS

We successfully constructed a HL7702 cell model of Sidt2+/+ and Sidt2-/-, and compared with Sidt2+/+ cells, the Sidt2-/- cell model showed significantly increased expressions of LC3-II/I and P62 (P < 0.01).Immunofluorescence assay showed a significant increase of LC3B and P62 expressions (P < 0.001) and obviously lowered expressions of Atg5, Atg7, and Atg12 in Sidt2-/- cells (P < 0.05).The co-localization of LC3B and P62 and that of LC3B and LAMP1 were both reduced and the number of acidic lysosomes was significantly lowered in Sidt2-/- cells (P < 0.05).

CONCLUSION

Sidt2 gene deletion disturbs the recognition and sequestration of P62 cargo protein by autophagosomes in human hepatocytes.At the same time, the decreased number of acidic lysosomes and the dysfunction of autophagosome and lysosome fusion cause the block of the autophagy-lysosome pathway, leading eventually to LC3B and P62 accumulation and impaired autophagy in the hepatocytes.

Paclobutrazol exposure induces apoptosis and impairs autophagy in hepatocytes via the AMPK/mTOR signaling pathway

Paclobutrazol (PBZ), one of the most widely used plant growth retardants in vegetables, fruits, and traditional Chinese medicine ingredients, exposes people to adverse events. In this study, HepaRG hepatocytes were cultured and exposed to PBZ (360 μM) in vitro to determine its mechanism. Results showed that PBZ exposure inhibited cell viability in a time- and dose-dependent manner and increased the oxidative stress and apoptosis ratio in HepaRG cells. These data revealed that the adenosine monophosphate-activated protein kinase (AMPK)/mammalian target of rapamycin (mTOR) has an important role in PBZ-induced cell apoptosis, which is mediated by impaired autophagy and blocked by the AMPK activator. In conclusion, PBZ exposure induces apoptosis and impairs autophagy in hepatocytes via the AMPK/mTOR signaling pathway.

Astragalus polysaccharide ameliorates steroid-induced osteonecrosis of femoral head through miR-206/HIF-1α/BNIP3 axis

Declining autophagy and rising apoptosis are the main factors driving the development of steroid-induced osteonecrosis of the femoral head (SONFH). Here, we showed that astragalus polysaccharide (APS) improved femoral head necrosis via regulation of cell autophagy and apoptosis through microRNA (miR)-206/hypoxia inducible factor-1 (HIF-1α)/BCL2 interacting protein 3 (BNIP3) axis. The expression of miR-206, HIF-1α, and BNIP3 in SONFH specimens and cell model were measured using qPCR. SONFH cell model was treated with APS. Cell autophagy was evaluated using LC3-immunofluorescence assays. Flow cytometry was conducted to assess cell apoptosis. Apoptosis-related proteins and autophagy-related proteins were determined using western blot. Besides, dual-luciferase reporter assay was employed to investigate the relationship between miR-206 and HIF-1α. Here we showed that miR-206 expression was upregulated in SONFH tissues and cell model. APS promoted autophagy and inhibited apoptosis in SONFH cell model via downregulating miR-206. What is more, HIF-1α was the target of miR-206. Knockdown of HIF-1α reversed the recovery effect of miR-206 inhibitor on SONFH cell model. Furthermore, BNIP3 was the target of HIF-1α. HIF-1α overexpression promoted autophagy and inhibited apoptosis, and knockdown of BNIP3 abolished the recovery effect of HIF-1α overexpression in SONFH cell model. These results provided evidence that APS reduced miR-206 expression, and the downregulated miR-206 increased BNIP3 expression by targeting HIF-1α to promote autophagy and inhibit bone cell apoptosis. Our research proved that APS effectively improved SONFH by regulating cell autophagy and apoptosis.

Interrelationship among paraptosis, apoptosis and autophagy in lung cancer A549 cells induced by BEAP, an antitumor protein isolated from the edible porcini mushroom Boletus edulis

In today's world, cancer is still the leading cause of human death. Among them, the incidence and mortality of lung cancer remain high, and have become the focus of research in the world. BEAP, a protein with anti-lung cancer activity, was isolated and purified from the edible mushroom Boletus edulis. Previous studies have shown that BEAP can inhibit the proliferation of non-small cell lung cancer A549 cells by inducing apoptosis and cell cycle arrest in vitro and in vivo. However, there are many ways in which antitumor proteins from edible and medicinal mushroom play their roles. It is worth exploring whether there are other antitumor mechanisms of BEAP, which can provide reference value for the development of new drugs targeting non-small cell lung cancer and the repurposing of existing drugs.

The NUPR1/p73 axis contributes to sorafenib resistance in hepatocellular carcinoma

The multikinase inhibitor sorafenib was the first drug approved by the FDA for treating patients with advanced hepatocellular carcinoma (HCC). However, sorafenib resistance remains a major challenge for improving the effectiveness of HCC treatment. Previously, we identified several genes modulated after sorafenib treatment of human HCC cells, including the stress-inducible nuclear protein 1 (NUPR1) gene. Multiple studies have shown that NUPR1 regulates autophagy, apoptosis, and chemoresistance. Here, we demonstrate that treatment of HCC cells with sorafenib resulted in the activation of autophagic flux. NUPR1 knock-down (KD) in HCC cells was associated with increased p62 expression, suggesting an impairment of autophagic flux, and with a significant increase of cell sensitivity to sorafenib. In NUPR1 KD cells, reduced levels of NUPR1 were associated with the increased expression of p73 as well as its downstream transcription targets PUMA, NOXA, and p21. Simultaneous silencing of p73 and NUPR1 in HCC cells resulted in increased resistance to sorafenib, as compared to the single KD of either gene. Conversely, pharmacological activation of p73, via the novel p73 small molecule activator NSC59984, determined synergistic anti-tumor effects in sorafenib-treated HCC cells. The combination of NSC59984 and sorafenib, when compared to either treatment alone, synergistically suppressed tumor growth of HCC cells in vivo. Our data suggest that the activation of the p73 pathway achieved by NUPR1 KD potentiates sorafenib-induced anti-tumor effects in HCC cells. Moreover, combined pharmacological therapy with the p73 activator NSC59984 and sorafenib could represent a novel approach for HCC treatment.

Liver injury mediated by the UII and its receptor (UT) system is possibly associated with the activation of autophagy-related and apoptosis-resisted pathways of Kupffer cells in acute liver failure

The system of urotensin II (UII) and its receptor (UT) (or: UII/UT system) mediates hepatic immune inflamed injury in acute liver failure (ALF) with autophagy inhibition. However, it is unknown whether the system has an effect on liver autophagy in ALF. In this study, we attempted to explore hepatic autophagy response in ALF through blocking the UII/UT signal. Autophagy-related genes were examined in the liver tissues of lipopolysaccharide (LPS)/d-galactosamine (D-GalN)-induced ALF after pretreatment of UT receptor specific antagonist urantide. And then, the levels of autophagy- and apoptosis-related genes were assayed in LPS-stimulated KCs via urantide pretreatment. We found that the expressions of hepatic autophagy related genes, including Beclin-1, Atg5, Atg7, LC3 and p62 mRNA, and LC3 II and p62 protein, were significantly downregulated in LPS/D-GalN-induced ALF mice; but they were not affected by pretreatment of urantide, a special UT receptor antagonist. To probe inflammatory mechanisms of the UII/UT system, we further investigated the effect of the system on Kupffer cells (KCs), the innate immune cells in liver. We found that urantide pretreatment significantly inhibited production of inflammatory injury molecules including TRAF6 and ROS in LPS-stimulated KCs. LPS stimulation induced LC3 and p62 mRNA and LC3 II and p62 protein expression in KCs. After urantide pretreatment, LC3 and p62 mRNA and LC3 II protein were downregulated, while p62 protein was upregulated in LPS-stimulated KCs. In addition, antiapoptotic protein Bcl-2 inhibition and proapoptotic protein cleaved caspase-3 increase were observed in LPS-stimulated KCs, and the effects were enhanced after urantide pretreatment in the study. We conclude that liver injury mediated by the UII/UT system is possibly associated with the activation of autophagy-related and apoptosis-resisted pathways of KCs in ALF.

Angelica sinensis polysaccharide (ASP) attenuates diosbulbin-B (DB)-induced hepatotoxicity through activating the MEK/ERK pathway

Diosbulbin-B (DB) is a promising therapeutic drug for cancer treatment; however, DB-induced hepatotoxicity seriously limits its clinical utilization. Based on this, the present study investigated whether the Angelica sinensis extract, angelica sinensis polysaccharide (ASP), was effective to attenuate DB-induced cytotoxicity in hepatocytes. The primary hepatocytes were isolated from rats and cultured in vitro, which were subsequently treated with high-dose DB (100 μM) and ASP (12 μg/ml) to establish the DB-induced hepatotoxicity models. MTT assay and flow cytometry (FCM) were performed to evaluate cell viability, and the results showed that high-dose DB-induced cell apoptosis and inhibition of proliferation were reversed by co-treating cells with ASP, which were supported by our Western Blot assay data that ASP upregulated Cyclin D1 and CDK2 to abrogate high-dose DB-induced cell cycle arrest. In addition, ASP exerted its regulating effects on cell autophagy, and we found that ASP increased LC3B-II/I ratio and Atg5, but decreased p62 to activate the autophagy flux. Of note, the MEK/ERK pathway could be activated by ASP in the DB-treated hepatocytes, and the protective effects of ASP on high-dose DB-induced hepatocyte death were abolished by co-treating cells with the autophagy inhibitor (3-methyladenine, 3-MA) and MEK/ERK selective inhibitor (SCH772984). Moreover, blockage of the MEK/ERK pathway suppressed cell autophagy in the hepatocytes co-treated with ASP and high-dose DB. Taken together, this in vitro study illustrated that ASP activated the MEK/ERK pathway mediated autophagy to suppress high-dose DB-induced hepatotoxicity.

Potential protective effect of hesperidin on hypoxia/reoxygenation-induced hepatocyte injury

Hesperidin (HDN) has been reported to have hydrogen radical- and hydrogen peroxide-removal activities and to serve an antioxidant role in biological systems. However, whether HDN protects hepatocytes (HCs) against hypoxia/reoxygenation (H/R)-induced injury remains unknown. The present study aimed to explore the role of HDN in H/R-induced injury. HCs were isolated and cultured under H/R conditions with or without HDN treatment. HC damage was markedly induced under H/R, as indicated by cell viability, supernatant lactate dehydrogenase levels and alanine aminotransferase levels; however, HDN treatment significantly reversed HC injury. Oxidative stress markers (malondialdehyde, superoxide dismutase, glutathioneand reactive oxygen species) were increased markedly during H/R in HCs; however, this effect was significantly attenuated after exposure to HDN. Compared with those of the control group, the mRNA expression levels of IL-6 and TNF-α in HCs and the concentrations of IL-6 and TNF-α in the supernatants increased significantly following H/R, and HDN significantly ameliorated these effects. Western blotting demonstrated that microtubule-associated protein 1 light chain 3α (MAP1LC3A, also known as LC3) and Beclin-1 protein expression levels increased, while sequestosome 1 levels decreased during H/R following exposure to HDN. The number of GFP-LC3 puncta in HCs following exposure to HDN was increased compared with that observed in HCs without HDN exposure under the H/R conditions after bafilomycin A1 treatment. In summary, the present study demonstrated that HDN attenuated HC oxidative stress and inflammatory responses while enhancing autophagy during H/R. HDN may have a potential protective effect on HCs during H/R-induced injury.

Rapamycin protects against aristolochic acid nephropathy in mice by potentiating mammalian target of rapamycin‑mediated autophagy

Autophagy serves a crucial role in the etiology of kidney diseases, including drug‑induced renal impairment, inherited kidney disease, diabetic nephropathy and aristolochic acid nephropathy (AAN) and is, therefore, a potential target for treatment. We previously demonstrated that rapamycin could attenuate AAN in mice; however, the underlying mechanism remains to be elucidated. Therefore, whether the renal protective effect of rapamycin (an autophagy activator) is related to autophagy in aristolochic acid (AA)‑treated mice was of particular interest. The pathophysiological roles of rapamycin were investigated in AA‑induced nephrotoxicity in mice and the mechanisms of rapamycin action were explored by evaluating the modulation of autophagy in rapamycin‑treated mice and cultured renal tubular epithelial cells. Supplementation with rapamycin reversed AA‑induced kidney injury in mice and improved AA‑induced autophagy damage in vivo and in vitro. Mechanistically, rapamycin inhibited the renal expression of phosphorylated (p‑)mammalian target of rapamycin (mTOR) and p‑ribosomal S6 protein kinase 1, which in turn activated renal autophagy and decreased apoptosis, probably by removing AA‑elicited damaged mitochondria and misfolded proteins. The findings of the present study demonstrated that rapamycin protects against AA‑induced nephropathy by activating the mTOR‑autophagy axis and suggested that rapamycin may be a promising pharmacological target for the treatment of AAN.

Characterizing Autophagy in the Cold Ischemic Injury of Small Bowel Grafts: Evidence from Rat Jejunum

Cold ischemic injury to the intestine during preservation remains an unresolved issue in transplantation medicine. Autophagy, a cytoplasmic protein degradation pathway, is essential for metabolic adaptation to starvation, hypoxia, and ischemia. It has been implicated in the cold ischemia (CI) of other transplantable organs. This study determines the changes in intestinal autophagy evoked by cold storage and explores the effects of autophagy on ischemic grafts. Cold preservation was simulated by placing the small intestines of Wistar rats in an IGL-1 (Institute George Lopez) solution at 4 °C for varying periods (3, 6, 9, and 12 h). The extent of graft preservation injury (mucosal and cellular injury) and changes in autophagy were measured after each CI time. Subsequently, we determined the differences in apoptosis and preservation injury after activating autophagy with rapamycin or inhibiting it with 3-methyladenine. The results revealed that ischemic injury and autophagy were induced by cold storage. Autophagy peaked at 3 h and subsequently declined. After 12 h of storage, autophagic expression was reduced significantly. Additionally, enhanced intestinal autophagy by rapamycin was associated with less tissue, cellular, and apoptotic damage during and after the 12-h long preservation. After reperfusion, grafts with enhanced autophagy still presented with less injury. Inhibiting autophagy exhibited the opposite trend. These findings demonstrate intestinal autophagy changes in cold preservation. Furthermore, enhanced autophagy was protective against cold ischemia-reperfusion damage of the small bowels.

Transmembrane Protein 166 and its Significance

Transmembrane protein 166 (TMEM166) is a lysosomal/endoplasmic reticulum (ER)-associated protein found in different species where it functions as a regulator of programmed cell death through autophagy and apoptosis. It is expressed in a variety of normal tissues and organs, and it is involved in a wide variety of physiological and pathological processes, including cancers, infection, autoimmune diseases, and neurodegenerative diseases. Previous studies indicated that TMEM166 is associated with autophagosomal membrane development. TMEM166 can cause lysosomal membrane permeabilization (LMP) leading to the release of proteolytic enzymes, e.g., cathepsins, that may cause potential mitochondrial membrane damage, which triggers several autophagic and apoptotic events. A low level of TMEM166 expression is also found in tumors, while high level of TMEM166 is found in brain ischemia. In addition, loss of TMEM166 leads to impaired NSC self-renewal and differentiation along with a decrease in autophagy. These findings offer a comprehensive understanding of the pathways involved in the role of TMEM166 in programmed cell death and treatment of various diseases.

Novel therapeutic strategies and perspectives for pancreatic cancer: Autophagy and apoptosis are key mechanisms to fight pancreatic cancer

Pancreatic cancer (PC) is the most lethal malignancy of the gastrointestinal tract. The poor prognosis of patients with PC is primarily due to lack of effective treatments against its progressive and metastatic behavior. Hence, figuring out the mechanisms underlying PC development and putting up with effective targeted therapies are of great significance to improve the prognosis of patients with PC. Apoptosis and autophagy serve to maintain tissue homoeostasis. Escaping from apoptosis or autophagy is one of the features of malignancy. PC is seriously resistant to autophagy and apoptosis, which explains its invasiveness and resistance to conventional treatment. Recently, several biological activities and pharmacological functions found in natural product extracts have been reported to inhibit PC progression. The current review focuses on understanding natural product extracts and their derivatives as one kind of novel treatments through affecting the apoptosis or autophagy in PC.

Different types of cell death in vascular diseases

In a mature organism, tissue homeostasis is regulated by cell division and cell demise as the two major physiological procedures. There is increasing evidence that deregulation of these processes is important in the pathogenicity of main diseases, including myocardial infarction, stroke, atherosclerosis, and inflammatory diseases. Therefore, there are ongoing efforts to discover modulating factors of the cell cycle and cell demise planners aiming at shaping innovative therapeutically modalities to the therapy of such diseases. Although the life of a cell is terminated by several modes of action, a few cell deaths exist-some of which resemble apoptosis and/or necrosis, and most of them are different from one another-that contribute to a wide range of functions to either support or disrupt the homoeostasis. Even in normal physiological conditions, cell life is severe within the cardiovascular system. Cells are persistently undergoing stretch, contraction, injurious metabolic byproducts, and hemodynamic forces, and a few of cells sustain decade-long lifetimes. The duration of vascular disease causes further exposure of vascular cells to a novel range of offences, most of which induce cell death. There is growing evidence on consequences of direct damage to a cell, as well as on responses of adjacent and infiltrating cells, which also have an effect on the pathology. In this study, by focusing on different pathways of cell death in different vascular diseases, an attempt is made to open a new perspective on the therapeutic goals associated with cell death in these diseases.

Unique Features of Hepatitis B Virus-Related Hepatocellular Carcinoma in Pathogenesis and Clinical Significance

Simple Summary

Hepatitis B virus (HBV) infection is the major risk factor for hepatocellular carcinoma (HCC). Understanding the unique features for HBV-induced HCC can shed new light on the unmet needs in its early diagnosis and effective therapy. During decades of chronic hepatitis B, hepatocytes undergoing repeated damage and regeneration accumulate genetic changes predisposing to HCC development. In addition to traditional mutations in viral and cellular oncogenes, HBV integration into the cell chromosomes is an alternative genetic change contributing to hepatocarcinogenesis. A striking male dominance in HBV-related HCC further highlights an interaction between androgen sex hormone and viral factors, which contributes to the gender difference via stimulating viral replication and activation of oncogenes preferentially in male patients. Meanwhile, a novel circulating tumor biomarker generated by HBV integration shows great potential for the early diagnosis of HCC. These unique HBV-induced hepatocarcinogenic mechanisms provide new insights for the future development of superior diagnosis and treatment strategies.

Abstract

Hepatitis B virus (HBV) infection is one of the important risk factors for hepatocellular carcinoma (HCC) worldwide, accounting for around 50% of cases. Chronic hepatitis B infection generates an inflammatory microenvironment, in which hepatocytes undergoing repeated cycles of damage and regeneration accumulate genetic mutations predisposing them to cancer. A striking male dominance in HBV-related HCC highlights the influence of sex hormones which interact with viral factors to influence carcinogenesis. HBV is also considered an oncogenic virus since its X and surface mutant proteins showed tumorigenic activity in mouse models. The other unique mechanism is the insertional mutagenesis by integration of HBV genome into hepatocyte chromosomes to activate oncogenes. HCC survival largely depends on tumor stages at diagnosis and effective treatment. However, early diagnosis by the conventional protein biomarkers achieves limited success. A new biomarker, the circulating virus–host chimera DNA from HBV integration sites in HCC, provides a liquid biopsy approach for monitoring the tumor load in the majority of HBV–HCC patients. To maximize the efficacy of new immunotherapies or molecular target therapies, it requires better classification of HCC based on the tumor microenvironment and specific carcinogenic pathways. An in-depth study may benefit both the diagnosis and treatment of HBV-related HCC.

Fas/FasL mediates NF-κBp65/PUMA-modulated hepatocytes apoptosis via autophagy to drive liver fibrosis

Fas/Fas ligand (FasL)-mediated cell apoptosis involves a variety of physiological and pathological processes including chronic hepatic diseases, and hepatocytes apoptosis contributes to the development of liver fibrosis following various causes. However, the mechanism of the Fas/FasL signaling and hepatocytes apoptosis in liver fibrogenesis remains unclear. The Fas/FasL signaling and hepatocytes apoptosis in liver samples from both human sections and mouse models were investigated. NF-κBp65 wild-type mice (p65^f/f), hepatocytes specific NF-κBp65 deletion mice (p65Δhepa), p53-upregulated modulator of apoptosis (PUMA) wild-type (PUMA-WT) and PUMA knockout (PUMA-KO) littermate models, and primary hepatic stellate cells (HSCs) were also used. The mechanism underlying Fas/FasL-regulated hepatocytes apoptosis to drive HSCs activation in fibrosis was further analyzed. We found Fas/FasL promoted PUMA-mediated hepatocytes apoptosis via regulating autophagy signaling and NF-κBp65 phosphorylation, while inhibition of autophagy or PUMA deficiency attenuated Fas/FasL-modulated hepatocytes apoptosis and liver fibrosis. Furthermore, NF-κBp65 in hepatocytes repressed PUMA-mediated hepatocytes apoptosis via regulating the Bcl-2 family, while NF-κBp65 deficiency in hepatocytes promoted PUMA-mediated hepatocytes apoptosis and enhanced apoptosis-linked inflammatory response, which contributed to the activation of HSCs and liver fibrogenesis. These results suggest that Fas/FasL contributes to NF-κBp65/PUMA-modulated hepatocytes apoptosis via autophagy to enhance liver fibrogenesis, and this network could be a potential therapeutic target for liver fibrosis.

Flutamide induces uterus and ovary damage in the mouse via apoptosis and excessive autophagy of cells following triggering of the unfolded protein response

Intrauterine exposure to flutamide not only causes abnormal development of the reproductive organs in male offspring, but also damages ovaries and uteri. The unfolded protein response (UPR) is believed to play an important role in embryo development and teratogenic processes. In the present study, pregnant mice were administered either flutamide (300mg kg-1 day-1, p.o.) on an equivalent volume of soybean oil (control) on Days 12-18 of gestation. Eight weeks after birth, female offspring in the flutamide-treated group had a lower bodyweight and lower ovarian and uterine weights, but there was no significant difference in uterine and ovarian weights normalised by bodyweight between the flutamide-treated and control groups. Furthermore, histopathological changes were observed in all uteri and ovaries in the flutamide-treated group, with fewer and less-developed follicles in the ovaries. In both the uteri and ovaries, flutamide increased the expression of UPR members, although the expression of cell cycle-related genes remained unchanged compared with the control group. Flutamide increased the expression of all autophagy- and apoptosis-related genes evaluated in the uterus, as well as some in the ovary. The results suggest that the in utero exposure of mice to flutamide may contribute to uterine and ovarian damage in the offspring, with endoplasmic reticulum stress possibly triggered by the UPR leading to the induction of excessive autophagy and apoptosis.