Nano-selenium attenuates mitochondrial-associated apoptosis via the PI3K/AKT pathway in nickel-induced hepatotoxicity in vivo and in vitro

Cooperative application of transcriptomics and ceRNA hypothesis: lncRNA-00742/miR-116 targets CD74 to mediate vanadium-induced mitochondrial apoptosis in duck liver

Vanadium (V) is a poisonous metallic environmental pollutant which poses hazard to the animal health of the liver. Competitive endogenous ribonucleic acids (ceRNAs) are essential elements of mitochondrial function and apoptosis, and their effects have been associated with the metal toxicity mechanism. However, the specific mechanism of ceRNAs in V-induced mitochondrial apoptosis in the liver has not been adequately investigated. Hence, we established an in vivo model of ducks exposed to V for 44 days and an in vitro model of V exposure duck hepatocyte knockdown/overexpression. Results showed that V exposure triggered the differential expression of 1106 lncRNAs and 11 miRNAs in the liver. Besides, we established the lncRNA-00742/miR-116/CD74 regulatory network by the dual luciferase reporter gene. Our results also found that V induced mitochondrial injury and up-regulated the expression levels of mitochondrial apoptosis-related factors. Furthermore, knockdown of miR-116 attenuated V-induced mitochondrial injury and apoptosis in hepatocytes. In contrast, overexpression of miR-116 and knockdown of CD74 exacerbated mitochondrial injury and apoptosis. BTZO-1 upregulated the CD74 level and alleviated V-induced mitochondrial apoptosis. In summary, V induced mitochondrial damage and apoptosis in duck liver by activating the lncRNA-00742/miR-116/CD74 axis. This research firstly revealed the mechanism of lncRNA-related ceRNAs regulating V-induced mitochondrial apoptosis.

Hepatic and immune modulatory effectiveness of lactoferrin loaded Selenium nanoparticles on bleomycin induced hepatic injury

This study aimed to estimate the hepatic and immune ameliorating potential of extracted bovine lactoferrin (LF), Selenium nanoparticles (SeNPs) or their combination (LF/SeNPs) against bleomycin (BLM) induced hepatic injury. Fifty adult male rats (160-200 g) were equally divided into five groups: (1) the saline control group, (2) BLM-injected (15 mg/kg twice a week, ip), and (3-5) groups treated orally with LF (200 mg/kg/day), SeNPs (0.0486 mg/kg/day) or LF/SeNPs combination (200.0486 mg/kg/day) for 6 weeks post BLM-intoxication. Blood and liver samples were subjected to biochemical, histopathological, and immunohistochemical analyses. The results revealed that BLM caused a significant increase in hepatic lipid peroxidation and nitric oxide, as well as serum markers of liver functions (AST, ALT and GGT activities), and levels of GM-CSF, CD4, TNF-α, IL-1β, TGF-β1, fibronectin, triglycerides, cholesterol and LDL-C. Additionally, hepatic glutathione, Na+/K+-ATPase, and glutathione peroxidase, as well as serum HDL-C, total protein and albumin levels were significantly reduced. Moreover, BLM injection resulted in marked histopathological alterations and severe expression of caspase 3. Post-treatment of BLM-intoxicated rats with LF, SeNPs or LF/SeNPs combination obviously improved the BLM-induced hepatic damages; this was achieved from the marked modulations in the mentioned parameters, besides improving the histopathological hepatic architecture. It is worth mentioning that LF/SeNPs exerted the greatest potency. In conclusion, the obtained results demonstrated that LF, SeNPs and LF/SeNPs succeeded in attenuating the BLM-induced hepatic dysfunction. Therefore, these supplements might be used to protect against drug-associated side effects.

Integrated transcriptomic and metabolomic approaches reveal molecular response and potential biomarkers of the deep-sea mussel Gigantidas platifrons to copper exposure

Metal pollution caused by deep-sea mining activities has potential detrimental effects on deep-sea ecosystems. However, our knowledge of how deep-sea organisms respond to this pollution is limited, given the challenges of remoteness and technology. To address this, we conducted a toxicity experiment by using deep-sea mussel Gigantidas platifrons as model animals and exposing them to different copper (Cu) concentrations (50 and 500 μg/L) for 7 days. Transcriptomics and LC-MS-based metabolomics methods were employed to characterize the profiles of transcription and metabolism in deep-sea mussels exposed to Cu. Transcriptomic results suggested that Cu toxicity significantly affected the immune response, apoptosis, and signaling processes in G. platifrons. Metabolomic results demonstrated that Cu exposure disrupted its carbohydrate metabolism, anaerobic metabolism and amino acid metabolism. By integrating both sets of results, transcriptomic and metabolomic, we find that Cu exposure significantly disrupts the metabolic pathway of protein digestion and absorption in G. platifrons. Furthermore, several key genes (e.g., heat shock protein 70 and baculoviral IAP repeat-containing protein 2/3) and metabolites (e.g., alanine and succinate) were identified as potential molecular biomarkers for deep-sea mussel's responses to Cu toxicity. This study contributes novel insight for assessing the potential effects of deep-sea mining activities on deep-sea organisms.

AP-1 and SP1 trans-activate the expression of hepatic CYP1A1 and CYP2A6 in the bioactivation of AFB1 in chicken

Dietary exposure to aflatoxin B1 (AFB1) is harmful to the health and performance of domestic animals. The hepatic cytochrome P450s (CYPs), CYP1A1 and CYP2A6, are the primary enzymes responsible for the bioactivation of AFB1 to the highly toxic exo-AFB1-8,9-epoxide (AFBO) in chicks. However, the transcriptional regulation mechanism of these CYP genes in the liver of chicks in AFB1 metabolism remains unknown. Dual-luciferase reporter assay, bioinformatics and site-directed mutation results indicated that specificity protein 1 (SP1) and activator protein-1 (AP-1) motifs were located in the core region -1,063/-948, -606/-541 of the CYP1A1 promoter as well as -636/-595, -503/-462, -147/-1 of the CYP2A6 promoter. Furthermore, overexpression and decoy oligodeoxynucleotide technologies demonstrated that SP1 and AP-1 were pivotal transcriptional activators regulating the promoter activity of CYP1A1 and CYP2A6. Moreover, bioactivation of AFB1 to AFBO could be increased by upregulation of CYP1A1 and CYP2A6 expression, which was trans-activated owing to the upregulalion of AP-1, rather than SP1, stimulated by AFB1-induced reactive oxygen species. Additionally, nano-selenium could reduce ROS, downregulate AP-1 expression and then decrease the expression of CYP1A1 and CYP2A6, thus alleviating the toxicity of AFB1. In conclusion, AP-1 and SP1 played important roles in the transactivation of CYP1A1 and CYP2A6 expression and further bioactivated AFB1 to AFBO in chicken liver, which could provide novel targets for the remediation of aflatoxicosis in chicks.

Nanotoxicity of tungsten trioxide nanosheets containing oxygen vacancy to human umbilical vein endothelial cells

Because of the excellent performance in photochemistry, WO3 is increasingly applied in the field of biology and medicine. However, little is known about the mechanism of WO3 cytotoxicity. In this work, WO3 nanosheets with oxygen vacancy are synthesized by solvothermal method, then characterized and added to culture medium of human umbilical vein endothelial cells (HUVECs) with different concentrations. We characterized and analyzed the morphology of nano-WO3 by transmission electron microscopy and calculated the specific data of oxygen vacancy by XPS. It is the first time the effect of WO3-x on cells that WO3-x can cause oxidative stress in HUVEC cells, resulting in DNA damage and thus promoting apoptosis. Transcriptome sequencing is performed on cells treated with low and high concentrations of WO3-x, and a series of key signals affecting cell proliferation and apoptosis are detected in differentially expressed genes, which indicates the research direction of nanotoxicity. The expression levels of key genes are also verified by quantitative PCR after cell treatment with different concentrations of WO3-x. This work fills the gap between the biocompatibility of nano WO3-x materials and molecular cytology and paves the way for investigating the mechanism and risks of oxygen vacancy in cancer therapy.

Nano-selenium Antagonizes Heat Stress-Induced Apoptosis of Rainbow Trout (Oncorhynchus mykiss) Hepatocytes by Activating the PI3K/AKT Pathway

The cold-water fish rainbow trout (Oncorhynchus mykiss) shows poor resistance to heat, which is the main factor restricting their survival and yield. With the advancement of nanotechnology, nano-selenium (nano-Se) has emerged as a key nano-trace element, showing unique advantages, including high biological activity and low toxicity, for studying the response of animals to adverse environmental conditions. However, little is still known regarding the potential protective mechanisms of nano-Se against heat stress-induced cellular damage. Herein, we aimed to investigate the mechanism underlying the antagonistic effects of nano-Se on heat stress. Four groups were assessed: CG18 (0 μg/mL nano-Se, 18 °C), Se18 (5.0 μg/mL nano-Se, 18 °C), CG24 (0 μg/mL nano-Se, incubated at 18 °C for 24 h and then transferred to 24 °C culture), and Se24 (5.0 μg/mL nano-Se, incubated at 18 °C for 24 h and then transferred to 24 °C culture). We found that after heat treatment (CG24 group), T-AOC, GPx, and CAT activities in rainbow trout hepatocytes showed a decrease of 36%, 33%, and 19%, respectively, while ROS and MDA levels showed an increase of 67% and 93%, respectively (P < 0.05). Meanwhile, the mRNA levels of the apoptosis-related genes caspase3, caspase9, Cyt-c, Bax, and Bax/Bcl-2 in the CG24 group were 41%, 47%, 285%, 65%, and 151% higher than those in the CG18 group, respectively, while those of PI3K and AKT were 31% and 17% lower, respectively (P < 0.05). Besides, flow cytometry analysis showed an increase in the level of apoptotic cells after heat exposure. More importantly, we observed that nano-Se cotreatment (Se24 group) remarkably attenuated heat stress-induced effects (P < 0.05). We conclude that heat stress induces oxidative stress and apoptosis in rainbow trout hepatocytes. Nano-Se ameliorates heat stress-induced apoptosis by activating the PI3K/AKT pathway. Our results provide a new perspective to improve our understanding of the ability of nano-Se to confer heat stress resistance.

Nickel induces hepatotoxicity by mitochondrial biogenesis, mitochondrial dynamics, and mitophagy dysfunction

Nickel (Ni) is an important and widely hazardous chemical industrial waste. Excessive Ni exposure could cause multi-organs toxicity in human and animals. Liver is the major target organ of Ni accumulation and toxicity, however, the precise mechanism is still unclear. In this study, nickel chloride (NiCl₂ )-treatment induced hepatic histopathological changes in the mice, and, transmission electron microscopy results showed mitochondrial swollen and deformed of hepatocyte. Next, the mitochondrial damages including mitochondrial biogenesis, mitochondrial dynamics, and mitophagy were measured after NiCl₂ administration. The results showed that NiCl₂ suppressed mitochondrial biogenesis by decreasing PGC-1α, TFAM, and NRF1 protein and mRNA expression levels. Meanwhile, the proteins involved in mitochondrial fusion were reduced by NiCl₂ , such as Mfn1 and Mfn2, however, mitochondrial fission proteins Drip1 and Fis1 were significantly increased. The up-regulation of mitochondrial p62 and LC3II expression indicated that NiCl₂ increased mitophagy in the liver. Moreover, the receptor-mediated mitophagy and ubiquitin (Ub)-dependent mitophagy were detected. NiCl₂ promoted PINK1 accumulation and Parkin recruitment on mitochondria. And, the receptor proteins of mitophagy Bnip3 and FUNDC1 were increased in the NiCl₂ -treated mice liver. Overall, these results show that NiCl₂ could induce mitochondria damage in the liver of mice, and, dysfunction of mitochondrial biogenesis, mitochondrial dynamics and mitophagy involved in the molecular mechanism of NiCl₂ -induced hepatotoxicity.

Selenium nanoparticles improve nickel-induced testosterone synthesis disturbance by down-regulating miR-708-5p/p38 MAPK pathway in Leydig cells

The present study was designed to investigate the role of miR-708-5p/p38 mitogen-activated protein kinase (MAPK) pathway during the mechanism of selenium nanoparticles (Nano-Se) against nickel (Ni)-induced testosterone synthesis disorder in rat Leydig cells. We conducted all procedures based on in vitro culture of rat primary Leydig cells. After treating Leydig cells with Nano-Se and NiSO₄ alone or in combination for 24 h, we determined the cell viability, reactive oxygen species (ROS) levels, testosterone production, and the protein expression of key enzymes involved in testosterone biosynthesis: steroidogenic acute regulatory (StAR) and cytochrome P450 cholesterol side chain cleavage enzyme (CYP11A1). The results indicated that Nano-Se antagonized cytotoxicity and eliminated ROS generation induced by NiSO₄ , suppressed p38 MAPK protein phosphorylation and reduced miR-708-5p expression. Importantly, we found that Nano-Se upregulated the expression of testosterone synthase and increased testosterone production in Leydig cells. Furthermore, we investigated the effects of p38 MAPK and miR-708-5p using their specific inhibitor during Nano-Se against Ni-induced testosterone synthesis disorder. The results showed that Ni-inhibited testosterone secretion was alleviated by Nano-Se co-treatment with p38 MAPK specific inhibitor SB203580 and miR-708-5p inhibitor, respectively. In conclusion, these findings suggested Nano-Se could inhibit miR-708-5p/p38 MAPK pathway, and up-regulate the key enzymes protein expression for testosterone synthesis, thereby antagonizing Ni-induced disorder of testosterone synthesis in Leydig cells.

Decreased thioredoxin reductase 3 expression promotes nickel-induced damage to cardiac tissue via activating oxidative stress-induced apoptosis and inflammation

Thioredoxin reductase 3 (Txnrd3) plays a crucial role in antioxidant and anti-cancer activities, and sperm maturation. The damage of heavy metals, including Nickel (Ni), is the most prominent harm in social development, and hampering Txnrd3 might exacerbate Ni-induced cardiac damage. In this study, a total of 160 8-week-old C57BL/N male mice with 25-30 g weight of Txnrd3+/+ wild-type and Txnrd3-/- homozygote-type were randomly divided into eight groups. The mice in the control and Ni groups were gavaged with distilled water and a freshly prepared 10 mg/kg NiCl₂ solution. Melatonin (Mel) groups were administered at a concentration of 2 mg/kg for 21 days at the mice's 0.1 ml/10 g body weight. Ni exposure up-regulated the messenger RNA (mRNA) levels of mitochondrial apoptosis (caspase-3, caspase-9, cytochrome c, p53, and BAX), autophagy (LC3, ATG 1, ATG 7, and Beclin-1), and inflammation (TNF-α, COX 2, IL-1β, IL-2, IL-6, and IL-7)-related markers, but down-regulated the mRNA levels of BCL-2, p62 and mTOR (p < .05). Ni exposure decreased the expression of BCL-2 and p62 protein but increased the expression levels of caspase-3, caspase-9, cytochrome c, p53, BAX, ATG 7, Beclin-1, TNF-α, COX 2, IL-1β and IL-2 protein (p < .05). Ni increased the contents of glutathione disulfide (GSSG) and malondialdehyde (MDA) and decreased the activities of catalase (CAT) and total superoxide dismutase (T-SOD) (p < .05). Decreased Txnrd3 expression significantly exacerbated changes compared to the Ni exposure (p < .05). Mel significantly attenuated these changes, but the effect decreased when Txnrd3 was inhibited (p < .05). In conclusion, decreased Txnrd3 expression promoted Ni-induced mitochondrial apoptosis and inflammation via oxidative stress and aggravated heart damage in mice. Decreased Txnrd3 expression significantly reduced the protective effect of Mel to Ni exposure.

Comprehensive proteomic analysis to elucidate the anti-heat stress effects of nano-selenium in rainbow trout (Oncorhynchus mykiss)

Because of the continuous intensification of global warming, extreme climate fluctuations, and high-density farming, cold-water rainbow trout (Oncorhynchus mykiss) are exposed to conditions of heat stress, which has severely impacted their survival and yield. Nano-selenium (nano-Se) shows higher biological activity and lower toxicity and has emerged as an ideal and ecological Se formulation. Herein rainbow trout were fed either a basal diet (control group) or basal diet plus 5 mg/kg nano-Se (treatment group). Samples were collected before (18 °C for 9 days; CG18, Se18) and after (24 °C for 8 h; CG24, Se24) heat stress. The DIA/SWATH approach was then applied to compare changes at the proteome level. We found 223 and 269 differentially abundant proteins in the CG18-CG24 and Se18-Se24 groups, respectively, which mainly included apoptosis-, heat stress-, and lipid-related proteins. In comparison with the CG18-CG24 group, the Se18-Se24 group showed higher abundance of molecular chaperone, such as Hsp70, Hsp90a.1, Hspa8, Hsp30, DNAJA4, Dnajb1, Bag2 and Ahsa1; on nano-Se supplementation, the heat stress-induced decline in the abundance of the selenoprotein MsrB2 was partially restored. Furthermore, nano-Se supplementation downregulated the abundance of lipid-related (CYP51, EBP, DHCR7, DHCR24, and APOB) and pro-apoptotic (caspase-8 and Bad) proteins. Protein-protein interaction analyses suggested that nano-Se inhibits apoptosis by upregulating the expression of Hsp70, Hsp90a.1, Hspa8, and Dnajb1; further, Hsp70/Hspa8 and MsrB2 appear to play a synergistic role in antioxidant defense under heat stress. Overall, our findings provide novel insights into nano-Se-mediated tolerance of heat stress, demonstrating that nano-Se exerts its anti-heat stress effects in rainbow trout by promoting protein repair, enhancing recovery of antioxidant enzyme activity, and alleviating lipid metabolism and apoptosis.

Heavy Metal Accumulation, Tissue Injury, Oxidative Stress, and Inflammation in Dromedary Camels Living near Petroleum Industry Sites in Saudi Arabia

The petroleum industry can impact the environment and human health. Heavy metals (HMs), including lead (Pb), cadmium (Cd), nickel (Ni), and vanadium (V), are toxic pollutants found in petroleum that can cause several severe diseases. This study investigated the impact of the oil industry on the Arabian camel (Camelus dromedarius) in the eastern region of Saudi Arabia, pointing to HMs accumulation, tissue injury, redox imbalance, inflammation, and apoptosis. Soil and camel samples (milk, blood, muscle, liver, and kidney) were collected from a site near an oil industry field and another two sites to analyze HMs. Pb, Cd, Ni, and V were increased in the soil and in the camel’s milk, blood, muscle, liver, and kidney at the polluted site. Serum aminotransferases, urea, and creatinine were elevated, and histopathological alterations were observed in the liver and kidney of camels at the oil industry site. Hepatic and renal lipid peroxidation, pro-inflammatory cytokines, Bax, and caspase-3 were increased, whereas cellular antioxidants and Bcl-2 declined in camels at the oil extraction site. In conclusion, the oil industry caused soil and tissue accumulation of HMs, liver and kidney injury, oxidative stress, and apoptosis in camels living close to the oil extraction site. These findings pinpoint the negative impact of the oil industry on the environment, animal, and human health.

Harnessing reactive oxygen/nitrogen species and inflammation: Nanodrugs for liver injury

Overall, 12% of the global population (800 million) suffers from liver disease, which causes 2 million deaths every year. Liver injury involving characteristic reactive oxygen/nitrogen species (RONS) and inflammation plays a key role in progression of liver disease. As a key metabolic organ of the human body, the liver is susceptible to injury from various sources, including COVID-19 infection. Owing to unique structural features and functions of the liver, most current antioxidants and anti-inflammatory drugs are limited against liver injury. However, the characteristics of the liver could be utilized in the development of nanodrugs to achieve specific enrichment in the liver and consequently targeted treatment. Nanodrugs have shown significant potential in eliminating RONS and regulating inflammation, presenting an attractive therapeutic tool for liver disease through controlling liver injury. Therefore, the main aim of the current review is to provide a comprehensive summary of the latest developments contributing to our understanding of the mechanisms underlying nanodrugs in the treatment of liver injury via harnessing RONS and inflammation. Meanwhile, the prospects of nanodrugs for liver injury therapy are systematically discussed, which provides a sound platform for novel therapeutic insights and inspiration for design of nanodrugs to treat liver disease.