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.

Mitochondria-associated endoplasmic reticulum membrane as a mediator of vanadium-induced endoplasmic reticulum quality control in duck brains.

Vanadium (V) plays a crucial role in normal cells, but excess V causes multi-organ toxicity, including neurotoxicity. Mitochondria-associated endoplasmic reticulum membrane (MAM) is a dynamic structure between endoplasmic reticulum (ER) and mitochondria that mediates ER quality control (ERQC). To explore the effects of excess V on MAM and ERQC in the brain, 72 ducks were randomly divided into two groups: the control group (basal diet) and the V group (30 mg V/kg basal diet). On days 22 and 44, brain tissues were collected for histomorphological observation and determination of trace element contents. In addition, the mRNA and protein levels of MAM and ERQC-related factors in the brain were analyzed. Results show that excessive V causes the imbalance of trace elements, the integrity disruption of MAM, rupture of ER and autophagosomes formation. Moreover, it inhibits IP3R and VDAC1 co-localization, down-regulates the expression levels of MAM-related factors, but up-regulates the expression levels of ERQC and autophagy related factors. Together, results indicate that V exposure causes disruption of MAM and activates ERQC, which is further causing autophagy.

Hexavalent-Chromium-Induced Disruption of Mitochondrial Dynamics and Apoptosis in the Liver via the AMPK-PGC-1α Pathway in Ducks.

Hexavalent chromium (Cr(VI)) is a hazardous substance that poses significant risks to environmental ecosystems and animal organisms. However, the specific consequences of Cr(VI) exposure in terms of liver damage remain incompletely understood. This study aims to elucidate the mechanism by which Cr(VI) disrupts mitochondrial dynamics, leading to hepatic injury in ducks. Forty-eight healthy 8-day-old ducks were divided into four groups and subjected to diets containing varying doses of Cr(VI) (0, 9.28, 46.4, and 232 mg/kg) for 49 days. Our results demonstrated that Cr(VI) exposure resulted in disarranged liver lobular vacuolation, along with increasing the serum levels of ALT, AST, and AKP in a dose-dependent manner, which indicated liver damage. Furthermore, Cr(VI) exposure induced oxidative stress by reducing the activities of T-SOD, SOD, GSH-Px, GSH, and CAT, while increasing the contents of MDA and H2O2. Moreover, Cr(VI) exposure downregulated the activities of CS and MDH, resulting in energy disturbance, as evidenced by the reduced AMPK/p-AMPK ratio and PGC-1α protein expression. Additionally, Cr(VI) exposure disrupted mitochondrial dynamics through decreased expression of OPA1, Mfn1, and Mfn2 and increased expression of Drp-1, Fis1, and MFF proteins. This disruption ultimately triggered mitochondria-mediated apoptosis, as evidenced by elevated levels of caspase-3, Cyt C, and Bax, along with decreased expression of Bcl-2 and the Bcl-2/Bax ratio, at both the protein and mRNA levels. In summary, this study highlights that Cr(VI) exposure induces oxidative stress, inhibits the AMPK-PGC-1α pathway, disrupts mitochondrial dynamics, and triggers liver cell apoptosis in ducks.

Berberine Protects against High-Energy and Low-Protein Diet-Induced Hepatic Steatosis: Modulation of Gut Microbiota and Bile Acid Metabolism in Laying Hens.

Berberine (BBR) is a natural alkaloid with multiple biotical effects that has potential as a treatment for fatty liver hemorrhagic syndrome (FLHS). However, the mechanism underlying the protective effect of BBR against FLHS remains unclear. The present study aimed to investigate the effect of BBR on FLHS induced by a high-energy, low-protein (HELP) diet and explore the involvement of the gut microbiota and bile acid metabolism in the protective effects. A total of 90 healthy 140-day-old Hy-line laying hens were randomly divided into three groups, including a control group (fed a basic diet), a HELP group (fed a HELP diet), and a HELP+BBR group (high-energy, high-protein diet supplemented with BBR instead of maize). Our results show that BBR supplementation alleviated liver injury and hepatic steatosis in laying hens. Moreover, BBR supplementation could significantly regulate the gut's microbial composition, increasing the abundance of Actinobacteria and Romboutsia. In addition, the BBR supplement altered the profile of bile acid. Furthermore, the gut microbiota participates in bile acid metabolism, especially taurochenodeoxycholic acid and α-muricholic acid. BBR supplementation could regulate the expression of genes and proteins related to glucose metabolism, lipid synthesis (FAS, SREBP-1c), and bile acid synthesis (FXR, CYP27a1). Collectively, our findings demonstrate that BBR might be a potential feed additive for preventing FLHS by regulating the gut microbiota and bile acid metabolism.

Molybdenum and/or cadmium induce NLRP3 inflammasome production by causing mitochondria-associated endoplasmic reticulum membrane dysfunction in sheep hepatocytes.

Accumulation of the heavy metals molybdenum (Mo) and cadmium (Cd) in the liver can induce organelle damage and inflammation, resulting in hepatotoxicity. The effect of Mo and/or Cd on sheep hepatocytes was investigated by determining the relationship between the mitochondria-associated endoplasmic reticulum membrane (MAM) and NLRP3 inflammasome. Sheep hepatocytes were divided into four groups: the control group, Mo group (600 µM Mo), Cd group (4 µM Cd) and Mo + Cd group (600 µM Mo+4 µM Cd). The results showed that Mo and/or Cd exposure increased the levels of lactate dehydrogenase (LDH) and nitric oxide (NO) in the cell culture supernatant, elevated the levels of intracellular Ca2+ and mitochondrial Ca2+, downregulated the expression of MAM-related factors (IP3R, GRP75, VDAC1, PERK, ERO1-α, Mfn1, Mfn2, ERP44), shortened the length of the MAM and reduced the formation of the MAM structure, eventually causing MAM dysfunction. Moreover, the expression levels of NLRP3 inflammasome-related factors (NLRP3, Caspase1, IL-1ß, IL-6, TNF-α) were also dramatically increased after Mo and Cd exposure, triggering NLRP3 inflammasome production. However, an IP3R inhibitor, 2-APB treatment significantly alleviated these changes. Overall, the data indicate that Mo and Cd coexposure leads to structural disruption and dysfunction of MAM, disrupts cellular Ca2+ homeostasis, and increases NLRP3 inflammasome production in sheep hepatocytes. However, the inhibition of IP3R alleviates NLRP3 inflammasome production induced by Mo and Cd.

Mitochondria-associated endoplasmic reticulum membranes participate mitochondrial dysfunction and endoplasmic reticulum stress caused by copper in duck kidney.

Copper (Cu) can be harmful to host physiology at high levels, although it is still unclear exactly how it causes nephrotoxicity. Mitochondrial dysfunction and endoplasmic reticulum (ER) stress are associated with heavy metal intoxication. Meanwhile, mitochondria and ER are connected via mitochondria-associated ER membranes (MAM). In order to reveal the crosstalk between them, a total of 144 1-day-old Peking ducks were randomly divided into four groups: control (basal diet), 100 mg/kg Cu, 200 mg/kg Cu, and 400 mg/kg Cu groups. Results found that excessive Cu disrupted MAM integrity, reduced the co-localization of IP3R and VDAC1, and significantly changed the MAM-related factors levels (Grp75, Mfn2, IP3R, MCU, PACS2, and VDAC1), leading to MAM dysfunction. We further found that Cu exposure induced mitochondrial dysfunction via decreasing the ATP level and the expression levels of COX4, TOM20, SIRT1, and OPA1 and up-regulating Parkin expression level. Meanwhile, Cu exposure dramatically increased the expression levels of Grp78, CRT, and ATF4, resulting in ER stress. Overall, these findings demonstrated MAM plays the critical role in Cu-induced kidney mitochondrial dysfunction and ER stress, which deepened our understanding of Cu-induced nephrotoxicity.

The key role of proteostasis at mitochondria-associated endoplasmic reticulum membrane in vanadium-induced nephrotoxicity using a proteomic strategy.

Excessive vanadium (V) contamination is an attracting growing concern, which can negatively affect the health of human and ecosystems. But how V causes nephrotoxicity and the role of mitochondria-associated endoplasmic reticulum membrane (MAM) in V-induced nephrotoxicity have remained elusive. To explore the detailed mechanism and screen of potential effective drugs for V-evoked nephrotoxicity, a total of 72 ducks were divided into two groups, control group and V group (30 mg/kg V). Results showed that excessive V damaged kidney function of ducks including causing histopathological abnormality, biochemical makers derangement and oxidative stress. Then MAM of duck kidneys was extracted to investigate differentially expressed proteins (DEPs) under V exposure using proteomics analysis. Around 4240 MAM-localized proteins were identified, of which 412 DEPs showed dramatic changes, including 335 upregulated and 77 downregulated DEPs. On the basis of gene ontology (GO), string and KEGG database analysis, excessive V led to nephrotoxicity primarily by affecting MAM-mediated metabolic pathways, especially elevating the endoplasmic Reticulum (ER) proteostasis related pathway. Further validation analysis of the detected genes and proteins of ER proteostasis related pathway under V poisoning revealed a consistent relationship with proteome analysis, indicating that V disrupted MAM-mediated ER proteostasis. Accordingly, our data proved the critical role for MAM in V-evoked nephrotoxicity, particularly with MAM-mediated ER proteostasis, providing promising insights into the toxicological exploration mechanisms of V.

Inhibition of the BNIP3/NIX-dependent mitophagy aggravates copper-induced mitochondrial dysfunction in duck renal tubular epithelial cells.

The accumulation of copper (Cu) in the organisms could lead to kidney damage by causing mitochondrial dysfunction. Given that mitochondria are one of the targets of Cu poisoning, this study aimed to investigate the role of mitophagy in Cu-induced mitochondrial dysfunction in renal tubular epithelial cells to understand the mechanism of Cu nephrotoxicity. Hence, the cells were treated with different concentrations of Cu sulfate (CuSO4 ) (0, 100, and 200 µM), and mitophagy inhibitor (Cyclosporine A, 0.5 µM) and/or 200 µM CuSO4 in the combination for 12 h. Results showed that Cu caused mitochondrial swelling, vacuoles, and cristae fracture; increased the number of mitochondrial and lysosome fluorescent aggregation points; upregulated the mRNA levels of mitophagy-associated genes (LC3A, LC3B, P62, BNIP3, NIX, OPTN, NDP52, Cyp D LAMP1, and LAMP2) and protein levels of LC3II/LC3I, BNIP3, and NIX, downregulated the mRNA and protein levels of P62; reduced the mitochondrial membrane potential (MMP), ATP content, mitochondrial respiratory control rate (RCR), mitochondrial respiratory control rate (OPR), and the mRNA and protein levels of PGC-1α, TOMM20, and Mfn2, but increased the mRNA and protein levels of Drp1. Besides, cotreatment with Cu and CsA dramatically decreased the level of mitophagy, but increased mitochondrial division, further reduced MMP, ATP content, RCR, and OPR, mitochondrial fusion and thereby reduced mitochondrial biogenesis. Taken together, these data indicated that Cu exposure induced BNIP3/NIX-dependent mitophagy in duck renal tubular epithelial cells, and inhibition of mitophagy aggravated Cu-induced mitochondrial dysfunction.

Selenium alleviates cadmium-induced mitophagy through FUNDC1-mediated mitochondrial quality control pathway in the lungs of sheep.

Cadmium (Cd) is a poisonous metal element that causes mitochondrial dysfunction. Selenium (Se) can reduce the damage of Cd to various organs of animals, but the protective mechanism of Se in Cd-induced lung injury has not been fully elucidated. For purpose of further illustrating the specific mechanism of Se alleviated Cd-triggered pulmonary toxicity, 48 sheep were divided into 4 groups, of which the sheep in the treatment group were taken 1 mg/kg body weight (BW) of Cd, 0.34 mg/kg BW of Se, and 0.34 mg Se + 1 mg/kg BW of Cd by intragastric administration for 50 d, respectively. The results indicated that Cd caused inflammatory cell infiltration and alveolar wall thickening, which facilitated mitochondrial vacuolation and formation of mitophagosomes in lung tissues. Simultaneously, Cd treatment impaired the antioxidant capacity of sheep lung tissue. Additionally, Cd treatment down-regulated the expression levels of mitochondrial biogenesis and mitochondrial fusion, but up-regulated the levels of mitochondrial fission and mitophagy mediated by FUNDC1. Moreover, the immunofluorescence co-localization puncta of LC3B/COX IV, LC3B/FUNDC1 were increased after Cd treatment. Nevertheless, co-treatment with Se improved effectively the above variation caused by Cd exposure. In summary, Se could mitigate Cd-generated mitophagy through FUNDC1-mediated mitochondrial quality control pathway in the lungs of sheep.

Hexavalent Chromium Exposure Induces Intestinal Barrier Damage via Activation of the NF-κB Signaling Pathway and NLRP3 Inflammasome in Ducks.

Hexavalent chromium [Cr(VI)] is a dangerous heavy metal which can impair the gastrointestinal system in various species; however, the processes behind Cr(VI)-induced intestinal barrier damage are unknown. Forty-eight healthy 1-day-old ducks were stochastically assigned to four groups and fed a basal ration containing various Cr(VI) dosages for 49 days. Results of the study suggested that Cr(VI) exposure could significantly increase the content of Cr(VI) in the jejunum, increase the level of diamine oxidase (DAO) in serum, affect the production performance, cause histological abnormalities (shortening of the intestinal villi, deepening of the crypt depth, reduction and fragmentation of microvilli) and significantly reduced the mRNA levels of intestinal barrier-related genes (ZO-1, occludin, claudin-1, and MUC2) and protein levels of ZO-1, occludin, cand laudin-1, resulting in intestinal barrier damage. Furthermore, Cr(VI) intake could increase the contents of hydrogen peroxide (H2O2) and malondialdehyde (MDA), tumor necrosis factor-α (TNF-α), interleukin-1ß (IL-1ß), and interleukin-18 (IL-18) but decrease the activities of total superoxide dismutase (T-SOD), catalase (CAT), and glutathione reductase (GR), as well as up-regulate the mRNA levels of TLR4, MyD88, NF-κB, TNFα, IL-6, NLRP3, caspase-1, ASC, IL-1ß, and IL-18 and protein levels of TLR4, MyD88, NF-κB, NLRP3, caspase-1, ASC, IL-1ß, and IL-18 in the jejunum. In conclusion, Cr(VI) could cause intestinal oxidative damage and inflammation in duck jejunum by activating the NF-κB signaling pathway and the NLRP3 inflammasome.

Cadmium exposure induces autophagy via PLC-IP3 -IP3 R signaling pathway in duck renal tubular epithelial cells.

Cadmium (Cd) is detrimental to animals, but nephrotoxic effects of Cd on duck have not been fully elucidated. To evaluate the impacts of Cd on Ca homeostasis and autophagy via PLC-IP3 -IP3 R pathway, primary duck renal tubular epithelial cells were exposed to 2.5 µM and 5.0 µM Cd, and combination of 5.0 µM Cd and 10.0 µM 2-APB or 0.125 µM U-73122 for 12 h (U-73122 pretreated for 1 h). These results evidenced that Cd induced [Ca2+ ]c overload mainly came from intracellular Ca store. Cd caused [Ca2+ ]mit and [Ca2+ ]c overload with [Ca2+ ]ER decrease, elevated Ca homeostasis related factors (GRP78, GRP94, CRT, CaN, CaMKII, and CaMKKß) expression, PLC and IP3 activities and IP3 R expression, but subcellular Ca2+ redistribution was reversed by 2-APB. PLC inhibitor U-73122 dramatically relieved the changes of the above indicators induced by Cd. Additionally, U-73122 obviously reduced the number of autophagosomes and LC3 accumulation spots, Atg5, LC3A, LC3B mRNA levels and LC3II/LC3I, Beclin-1 protein levels induced by Cd, and markedly elevated p62 mRNA and protein levels. Overall, the results verified that Cd induced [Ca2+ ]c overload mainly originated from ER Ca2+ release mediated by PLC-IP3 -IP3 R pathway, then triggered autophagy in duck renal tubular epithelial cells.

Selenium Antagonizes Cadmium-Induced Inflammation and Oxidative Stress via Suppressing the Interplay between NLRP3 Inflammasome and HMGB1/NF-κB Pathway in Duck Hepatocytes.

Cadmium (Cd) is a toxic heavy metal that can accumulate in the liver of animals, damaging liver function. Inflammation and oxidative stress are considered primary causes of Cd-induced liver damage. Selenium (Se) is an antioxidant and can resist the detrimental impacts of Cd on the liver. To elucidate the antagonism of Se on Cd against hepatocyte injury and its mechanism, duck embryo hepatocytes were treated with Cd (4 µM) and/or Se (0.4 µM) for 24 h. Then, the hepatocyte viability, oxidative stress and inflammatory status were assessed. The findings manifested that the accumulation of reactive oxygen species (ROS) and the levels of pro-inflammatory factors were elevated in the Cd group. Simultaneously, immunofluorescence staining revealed that the interaction between NOD-like receptor pyran domain containing 3 (NLRP3) and apoptosis-associated speck-like protein (ASC) was enhanced, the movement of high-mobility group box 1 (HMGB1) from nucleus to cytoplasm was increased and the inflammatory response was further amplified. Nevertheless, the addition of Se relieved the above-mentioned effects, thereby alleviating cellular oxidative stress and inflammation. Collectively, the results suggested that Se could mitigate Cd-stimulated oxidative stress and inflammation in hepatocytes, which might be correlated with the NLRP3 inflammasome and HMGB1/nuclear factor-κB (NF-κB) signaling pathway.

Selenium alleviates cadmium-induced aging via mitochondrial quality control in the livers of sheep.

Cadmium (Cd) is a heavy metal with toxicity that induces mitochondrial dysfunction and aging, and selenium (Se) can alleviate its toxicity. However, the underlying mechanism of Se alleviating Cd-induced aging in sheep livers deserves further study. This study was to explore the protective mechanism of Se on the Cd-induced aging in the livers of sheep. A total of forty-eight sheep weighing about 10 kg were randomly divided into four groups: control group, Se group [0.34 mg Se·kg-1·body weight (BW)], Cd group (1 mg Cd·kg-1·BW), and Se + Cd group (0.34 mg Se·kg-1·BW +1 mg Cd·kg-1·BW). The results showed that Cd caused vacuolization, granule denaturation, and mitochondrial vacuolization in hepatocytes. Furthermore, the levels of catalase (CAT), total superoxide dismutase (T-SOD), glutathione (GSH) and adenosine triphosphate (ATP) in liver mitochondria were down-regulated, but the levels of hydrogen peroxide (H2O2) and malonaldehyde (MDA) were up-regulated under Cd treatment. Besides, the cyclin-dependent kinase inhibitor 1 (P21) immunohistochemistry positive signal and the puncta of immunofluorescence co-locations of E3 ubiquitin ligase Parkin (Parkin)/ cytochrome c oxidase IV (COX IV) and light chain 3B (LC3B)/COX IV were increased under Cd stress. Moreover, Cd exposure decreased the levels of mitochondrial biogenesis and fusion related factors and minichromosome maintenance protein 2 (MCM2), but increased the levels of mitochondrial fission, mitophagy, and cell aging related factors. However, the variations mentioned above caused by Cd were effectively ameliorated by Se co-treatment. In conclusion, Se might alleviate Cd-induced aging via regulating mitochondrial quality control in sheep livers.

Molecular cloning, characterization, and expression analysis of TIPE1 in chicken (Gallus gallus): Its applications in fatty liver hemorrhagic syndrome.

Tumor necrosis factor-α-induced protein eight like 1 (TIPE1) plays important role in autophagy, immunity, and lipid metabolism. The potential role of TIPE1 in fatty liver hemorrhage syndrome (FLHS) is elusory. In the present study, the full-length coding sequence of TIPE1 was cloned, and the polyclonal antibody of TIPE1 was produced by the recombinant TIPE1 protein. The bioinformatic analysis showed that the chicken TIPE1 protein, which was predicted to be a hydrophobic and non-transmembrane protein without signal peptide was highly different from that of mammals. Furthermore, proceeded by using TIPE1 polyclonal antibody, the tissue distribution analysis showed that TIPE1 protein is ubiquitously expressed in various tissues in adult hens and chicks, with its level being higher in the liver and, spleen, moderate in intestinal, brain, and heart. Besides, immunohistochemistry and immunofluorescence observation demonstrated that TIPE1 mainly existed in the cytoplasm in liver, duodenum, and cecum cell. Notably, the TIPE1 expressions were significantly decreased in laying hens suffering from FLHS. Collectively, these results showed that the chicken TIPE1 polyclonal antibody was successfully prepared and further used to analyze the expression profiles of chicken. And the expression of TIPE1 was reduced in FLHS which provided the foundation for further investigation in FLHS.

Endoplasmic reticulum-mitochondria coupling attenuates vanadium-induced apoptosis via IP3R in duck renal tubular epithelial cells.

Vanadium (V) is necessary for the health and growth of animals, but excessive V has harmful effects on the ecosystem health. Endoplasmic reticulum (ER)-mitochondria coupling as a membrane structure connects the mitochondrial outer membrane with the ER. The mitochondria-associated ER membrane (MAM) is a region of the ER-mitochondria coupling and is essential for normal cell function. Currently, the crosstalk between ER-mitochondrial coupling and apoptosis in the toxic mechanism of V on duck kidney is still unclear. In this study, duck renal tubular epithelial cells were incubated with different concentrations of sodium metavanadate (NaVO3) and/or inositol triphosphate receptor (IP3R) inhibitor 2-aminoethyl diphenyl borate (2-APB) for 24 h. The results showed that V could significantly increase lactate dehydrogenase (LDH) release, the mitochondrial calcium level and the numbers of the fluorescent signal points of IP3R; shortened the length ER-mitochondria coupling and reduced its formation; markedly upregulate the mRNA levels of MAM-related genes and protein levels, causing MAM dysfunction. Additionally, V treatment appeared to upregulate pro-apoptotic genes and downregulate anti-apoptotic genes, followed by cell apoptosis. The V-induced changes were alleviated by treatment with IP3R inhibitor. In summary, V could induce the dysfunction of ER-mitochondrial coupling and apoptosis, and inhibition of ER-mitochondrial coupling could attenuate V-induced apoptosis in duck renal tubular epithelial cells.

Molybdenum and cadmium co-exposure induces endoplasmic reticulum stress-mediated apoptosis by Th1 polarization in Shaoxing duck (Anas platyrhyncha) spleens.

Excessive molybdenum (Mo) and cadmium (Cd) are deleterious to animals, but immunotoxicity co-induced by Mo and Cd remains unclear. To ascertain the confederate impacts of Mo and Cd on endoplasmic reticulum (ER) stress-mediated apoptosis by Helper T (Th) cells 1 polarization in the spleen of ducks, we randomly allocated forty 8-day-old Shaoxing ducks (Anas platyrhyncha) into 4 groups and reared them with having different doses of Mo and/or Cd basic diet. At the 16th week of the experiment, serum and spleen tissues were extracted. Data confirmed that Mo and/or Cd strikingly promoted their levels in spleen, caused histological abnormality and trace elements imbalance, and disrupted Th1/Th2 balance to divert toward Th1, then triggered ER stress by increasing three branches PERK/eIF2α/CHOP, IRE1/Caspase-12 and TRAF2/JNK signaling pathways-related genes mRNA and proteins levels, which stimulated apoptosis by elevating Bak-1, Bax, Caspase-9, Caspase-3 mRNA expression, and cleaved-Caspase-9/Caspase-9, cleaved-Caspase-3/Caspase-3 proteins expression as well as apoptosis rate, and decreasing Bcl-xL, Bcl-2 mRNA expression and Bcl-2/Bax ratio. Besides, the variation in combined group was most evident. Briefly, the study indicates that Mo and/or Cd exposure trigger ER stress-induced apoptosis via Th1 polarization in duck spleens, and its mechanism is somehow closely linked with the deposition of Cd and Mo, which may aggravate toxic damage to spleen.

Activation of endoplasmic reticulum-mitochondria coupling drives copper-induced autophagy in duck renal tubular epithelial cells.

Copper (Cu) as a transition metal can be toxic to public and ecosystem health at high level, but the specific mechanism of Cu-evoked nephrotoxicity remains elusive. Here, we first revealed the crosstalk between mitofusin2 (Mfn2)-dependent mitochondria-associated endoplasmic reticulum membrane (MAM) dynamics and autophagy in duck renal tubular epithelial cells under Cu exposure. Primary duck renal tubular epithelial cells were treated with 100 and 200 µM Cu sulfate for 12 h and exposed to lentivirus to deliver mitofusin2 (Mfn2). We found that excessive Cu disrupted MAM integrity, decreased the mitochondrial calcium level, co-localization of IP3R and VDAC1, the mRNA levels of PACS2, Mfn2, IP3R and MCU, and Mfn2 and VDAC1 protein levels, causing MAM dysfunction. Furthermore, Mfn2 overexpression ameliorated Cu-induced MAM dysfunction, and increased Cu-evoked autophagy in duck renal tubular epithelial cells accompanied with the elevation of autophagosomes number, ROS level, LC3 puncta, Atg5 and LC3B mRNA levels, and Beclin1, Atg14, LC3BII/LC3BI protein levels. Accordingly, our data proved that excessive Cu could trigger MAM dysfunction and autophagy in duck renal tubular epithelial cells, and Cu-induced autophagy could be activated through Mfn2-dependent MAM, providing evidence on the toxicological exploration mechanisms of Cu.

Molybdenum and Cadmium Co-induce Mitochondrial Quality Control Disorder via FUNDC1-Mediated Mitophagy in Sheep Kidney.

Molybdenum (Mo), fundamental trace mineral for animals and plants, but undue Mo damages animal health. Cadmium (Cd) is a toxic heavy metal that exists in the environment. Nevertheless, the mechanism of Mo and Cd on mitochondrial quality control are still indistinct. The objective of this research was to explore the effects of mitophagy on mitochondrial quality control via the FUNDC1-mediated by Mo and Cd in sheep kidney. Forty-eight 2-month-old sheep were stochastically divided into four groups, as shown below: control group, Mo [45 mg/kg body weight (BW)] group, Cd (1 mg/kg BW) group and Mo (45 mg/kg BW)+Cd (1 mg/kg BW) group, with 50 days feed technique. The results showed that Mo or/and Cd attract an unbalance of trace minerals and vacuoles and granular degeneration of renal tubular epithelial cells, and increase the number of mitophagosomes and vacuole-mitochondria and LC3 puncta and MDA and H2O2 contents, and decrease ATP content in the kidney. Moreover, Mo or/and Cd treatment could upregulate the mRNA levels of FUNDC1, LC3A, LC3B, PGAM5, DRP1, FIS1 and MFF, and the protein levels of FUNDC1, p-FUNDC1, LC3II/LC3I, DRP1, MFF and FIS1, downregulate the mRNA levels of MFN1, MFN2, OPA1, PGC-1α, SIRT1, SIRT3, FOXO1 and FOXO3, and the protein levels of MFN1, MFN2, OPA1 and PGC-1α. Notably, variations of above-mentioned factors in Mo and Cd group were more obvious than in Mo or Cd groups. Taken together, these results displayed that Mo and Cd co-treatment might induce mitochondrial quality control disorder via FUNDC1-mediated mitophagy in sheep kidney.

Selenium protects against cadmium-induced cardiac injury by attenuating programmed cell death via PI3K/AKT/PTEN signaling.

Cadmium (Cd) is an environmental pollutant that has an enormous influence on agricultural production, but selenium (Se) can alleviate its toxicity. The present study aimed to illustrate the effects of Se on Cd-induced heart injury. All 40 rabbits were randomly divided into four groups: control group, Se [0.5 mg kg-1 ·body weight (BW)] group, Cd (1 mg kg-1 ·BW) group, and Se + Cd group. After 30 days of feeding, morphological changes, the levels of oxidative stress and myocardial enzyme, the content of cardiac troponin T, programmed cell death (pyroptosis, autophagy and apoptosis), and PI3K/AKT/PTEN transduction capacity were observed. The results showed that Cd destroyed the physiological balance of trace elements and caused myocardial damage, increased the cardiac oxidative damage and led to programmed cell death. Coadministration of Se prominently ameliorated histological lesions and improved cardiac function of hearts in Cd-induced rabbits. Furthermore, Se exerted detoxification and oxidation resistance, maintained trace element homeostasis, and alleviated the changes of mRNA and protein levels of pyroptosis-, autophagy- and apoptosis-controlling factors and PI3K/AKT/PTEN signal molecules caused by Cd. In conclusion, Se might protect against Cd-induced pyroptosis, autophagy and apoptosis by interfering with PI3K/AKT/PTEN signaling in heart.

Involvement of calcium homeostasis and unfolded protein response in autophagy co-induced by molybdenum and cadmium in duck (Anas platyrhyncha) brain.

Excess molybdenum (Mo) and cadmium (Cd) are harmful to animals, but neurotoxicity caused by Mo and Cd co-exposure in ducks is yet unknown. To assess joint impacts of Mo and Cd on autophagy via calcium homeostasis and unfolded protein response (UPR) in duck brain, 40 healthy 7-day-old ducks (Anas platyrhyncha) were assigned to 4 groups at random and fed diets supplemented with different doses of Mo or/and Cd for 16 weeks, respectively. Brain tissues were excised for experiment. Results exhibited that Mo or/and Cd disturbed calcium homeostasis by decreased ATPase activities and increased calcium (Ca) content, and upregulated calcium homeostasis-related factors Ca2+/CAM-dependent kinase IIɑ (CaMKIIɑ), calcineurin (CaN), inositol-1,4,5-trisphosphate receptor (IP3R), and calreticulin (CRT) expression levels. Meanwhile, the upregulation of UPR-related factor expression levels indicated that Mo or/and Cd activated UPR. Moreover, Mo or/and Cd triggered autophagy through promoting the number of autophagosomes and LC3II immunofluorescence intensity and altering autophagy key factor expression levels. Correlation analysis showed that there were obvious connections among Ca2+ homeostasis, endoplasmic reticulum (ER) stress, and autophagy induced by Mo or/and Cd. Thence, it can be speculated that autophagy initiated by Mo or/and Cd may be associated with interfering Ca2+ homeostasis and triggering UPR.