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Cadmium (Cd) and excess molybdenum (Mo) are multiorgan toxic, but the detrimental impacts of Cd and/or Mo on poultry have not been fully clarified. Thence, a 16-week sub-chronic toxic experiment was executed with ducks to assess the toxicity of Cd and/or Mo. Our data substantiated that Cd and Mo coexposure evidently reduced GSH-Px, GSH, T-SOD, and CAT activities and elevated H 2 O 2 and MDA concentrations in myocardium. What is more, the study suggested that Cd and Mo united exposure synergistically elevated Fe 2+ content in myocardium and activated AMPK/mTOR axis, then induced ferroptosis by obviously upregulating ACSL4, PTGS2, and TFRC expression levels and downregulating SLC7A11, GPX4, FPN1, FTL1, and FTH1 expression levels. Additionally, Cd and Mo coexposure further caused excessive ferritinophagy by observably increasing autophagosomes, the colocalization of endogenous FTH1 and LC3, ATG5, ATG7, LC3II/LC3I, NCOA4, and FTH1 expression levels. In brief, this study for the first time substantiated that Cd and Mo united exposure synergistically induced ferroptosis and excess ferritinophagy by AMPK/mTOR axis, finally augmenting myocardium injure in ducks, which will offer an additional view on united toxicity between two heavy metals on poultry., (© 2024 Wiley Periodicals LLC.)

Cadmium (Cd) and excess molybdenum (Mo) pose serious threats to animal health. Our previous study has determined that Cd and/or Mo exposure can cause ovarian damage of ducks, while the specific mechanism is still obscure. To further investigate the toxic mechanism of Cd and Mo co-exposure in the ovary, forty 8-day-old female ducks were randomly allocated into four groups for 16 weeks, and the doses of Cd and Mo in basic diet per kg were as follows: control group, Mo group (100 mg Mo), Cd group (4 mg Cd), and Mo + Cd group (100 mg Mo + 4 mg Cd). Cadmium sulfate 8/3-hydrate (CdSO 4 ·8/3H 2 O) and hexaammonium molybdate ((NH 4 ) 6 Mo 7 O 24 ·4H 2 O) were the origins of Cd and Mo, respectively. At the 16th week of the experiment, all ovary tissues were collected for the detection of related indexes. The data indicated that Mo and/or Cd induced trace element disorders and Th1/Th2 balance to divert toward Th1 in the ovary, which activated endoplasmic reticulum (ER) stress and then provoked necroptosis through triggering RIPK1/RIPK3/MLKL signaling pathway, and eventually caused ovarian pathological injuries and necroptosis characteristics. The alterations of above indicators were most apparent in the joint group. Above all, this research illustrates that Mo and/or Cd exposure can initiate necroptosis through Th1/Th2 imbalance-modulated ER stress in duck ovaries, and Mo and Cd combined exposure aggravates ovarian injuries. This research explores the molecular mechanism of necroptosis caused by Mo and/or Cd, which reveals that ER stress attenuation may be a therapeutic target to alleviate necroptosis., Competing Interests: Declaration of Competing Interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this article., (Copyright © 2023. Published by Elsevier B.V.)

Cadmium (Cd) and high molybdenum (Mo) are injurious to the body. Previous research has substantiated that Cd and Mo exposure caused testicular injury of ducks, but concrete mechanism is not fully clarified. To further survey the toxicity of co-exposure to Cd and Mo in testis, 40 healthy 8-day-old Shaoxing ducks (Anas platyrhyncha) were stochasticly distributed to 4 groups and raised with basic diet embracing Cd (4 mg/kg Cd) or Mo (100 mg/kg Mo) or both. At the 16th wk, testis tissues were gathered. The characteristic ultrastructural changes related to apoptosis and ferroptosis were observed in Mo or Cd or both groups. Besides, Mo or Cd or both repressed nuclear factor erythroid 2-related factor 2 (Nrf2) pathway via decreasing Nrf2, Heme oxygenase-1 (HO-1), NAD(P)H quinone oxidoreductase 1 (NQO1), Glutamate-cysteine ligase catalytic subunit (GCLC) and Glutamate-cysteine ligase modifier subunit (GCLM) mRNA expression of and Nrf2 protein expression, then stimulated apoptosis by elevating Bcl-2 antagonist/killer-1 (Bak-1), Bcl-2-associated X-protein (Bax), Cytochrome complex (Cyt-C), caspase-3 mRNA expression, cleaved-caspase-3 protein expression and apoptosis rate, as well as reducing B-cell lymphoma-2 (Bcl-2) mRNA expression and ratio of Bcl-2 to Bax, and triggered ferroptosis by upregulating Acyl-CoA Synthetase Long Chain Family Member 4 (ACSL4), transferrin receptor (TFR1) and Prostaglandin-Endoperoxide Synthase 2 (PTGS2) expression levels, and downregulating ferritin heavy chain 1 (FTH1), ferritin light chain 1 (FTL1), ferroportin 1 (FPN1), solute carrier family 7 member 11 (SCL7A11) and glutathione peroxidase 4 (GPX4) expression levels. The most obvious changes of these indexes were observed in co-treated group. Altogether, the results announced that Mo or Cd or both evoked apoptosis and ferroptosis by inhibiting Nrf2 pathway in the testis of ducks, and co-exposure to Mo and Cd exacerbated these variations., (Copyright © 2024 The Authors. Published by Elsevier Inc. All rights reserved.)

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., (© 2024. The Author(s), under exclusive licence to Springer-Verlag GmbH Germany, part of Springer Nature.)

Excess molybdenum (Mo) is harmful to animals, but its nephrotoxicity has not been comprehensively explained. To appraise the influences of excess Mo on Ca homeostasis and apoptosis via PLC/IP 3 /IP 3 R axis, primary duck renal tubular epithelial cells were exposed to 480 μM and 960 μM Mo, and joint of 960 μM Mo and 10 μM 2-APB or 0.125 μM U-73122 for 12 h (U-73122 pretreated for 1 h), respectively. The data revealed that the increment of [Ca 2+ ] c induced by Mo mainly originated from intracellular Ca storage. Mo exposure reduced [Ca 2+ ] ER , elevated [Ca 2+ ] mit , [Ca 2+ ] c , and the expression of Ca homeostasis-related factors (Calpain, CaN, CRT, GRP94, GRP78 and CaMKII). 2-APB could effectively reverse subcellular Ca 2+ redistribution by inhibiting IP 3 R, which confirmed that [Ca 2+ ] c overload induced by Mo originated from ER. Additionally, PLC inhibitor U-73122 remarkably mitigated the change, and dramatically reduced the number of apoptotic cells, the expression of Bak-1, Bax, cleaved-Caspase-3/Caspase-3, and notably increased the expression of Bcl-xL, Bcl-2, and Bcl-2/Bax ratio. Overall, the results confirmed that the Ca 2+ liberation of ER via PLC/IP 3 /IP 3 R axis was the main cause of [Ca 2+ ] c overload, and then stimulated apoptosis in duck renal tubular epithelial cells., (© 2023 Wiley Periodicals LLC.)

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 H 2 O 2 . 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.

Superfluous molybdenum (Mo) and cadmium (Cd) in the environment are detrimental to organisms through their accumulation. The NF-κB/TNF-α axis plays a vital part in regulating necroptosis and apoptosis. However, the impacts of Mo and/or Cd on myocardium injury in ducks and the function of NF-κB/TNF-α axis are not clear in the process. In this research, ducks exposed to different dosages of Mo and/or Cd were applied as the study object. The findings substantiated that the accumulation of Mo and/or Cd caused elements imbalance and necroptosis in myocardial tissue. As p-NF-κB/TNF-α expression up-regulated, RIPK1/RIPK3/p-MLKL expression significantly increased in all treatment groups, while the expression of c-caspase-8/3 markedly decreased. Moreover, apoptosis rate obviously decreased in Cd treated groups and clearly elevated in Mo group. Mitochondria-mediated apoptosis was activated by excessive Mo and inhibited by Mo + Cd, but Cd exposure alone had little effect on it. Collectively, our research confirmed that Mo and/or Cd evoked necroptosis via NF-κB/TNF-α axis, and decreased death receptor-mediated apoptosis in duck myocardium, the impacts of Mo and/or Cd on mitochondrial-mediated apoptosis were different. These results are significant for studying toxicology of Mo and/or Cd and preserving the ecosystem., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2023 Elsevier B.V. All rights reserved.)

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 (CuSO 4 ) (0, 100, and 200 μM), and mitophagy inhibitor (Cyclosporine A, 0.5 μM) and/or 200 μM CuSO 4 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., (© 2022 Wiley Periodicals LLC.)

Excessive amounts of molybdenum (Mo) and cadmium (Cd) are toxicant, but their combined immunotoxicity are not clearly understood. To estimate united impacts of Mo and Cd on pyroptosis and autophagy by PI3K/AKT axis in duck spleens, Mo or/and Cd subchronic toxicity models of ducks were established by feeding diets with different dosages of Mo or/and Cd. Data show that Mo or/and Cd cause oxidative stress by increasing MDA concentration, and decreasing T-AOC, CAT, GSH-Px and T-SOD activities, restrain PI3K/AKT axis by decreasing PI3K, AKT, p-AKT expression levels, which evokes pyroptosis and autophagy by elevating IL-1β, IL-18 concentrations and NLRP3, Caspase-1, ASC, GSDME, GSDMA, NEK7, IL-1β, IL-18 expression levels, promoting autophagosomes, LC3 puncta, Atg5, LC3A, LC3B, LC3II/LC3I and Beclin-1 expression levels, and reducing expression levels of P62 and Dynein. Furthermore, the variations of abovementioned indexes are most pronounced in co-treated group. Overall, results reveal that Mo or/and Cd may evoke pyroptosis and autophagy by PI3K/AKT axis in duck spleens. The association of Mo and Cd exacerbates the changes., (© 2022 Wiley Periodicals LLC.)

Cadmium (Cd) and excess molybdenum (Mo) have multiple organ toxicity, and testis is one of their important target organs, but the reproductive toxicity of Mo and Cd combined treatment is still unclear. To explore the effects of Mo and Cd co-exposure on DNA damage and autophagy from the insight of ATM/AMPK/mTOR axis in duck testes, we randomly assigned 40 healthy 8-day-old ducks to control, Mo (100 mg/kg Mo), Cd (4 mg/kg Cd), and Mo + Cd groups for 16 weeks. Results found that Mo and/or Cd exposure caused trace elements imbalance, oxidative stress with a decrease in the activities of GSH-Px, CAT, T-SOD and GSH content, an increase in the concentrations of H 2 O 2 and MDA and pathological damage. Additionally, Mo and/or Cd markedly raised DNA damage-related factors expression levels and 8-OHdG content, caused G1/S arrest followed by decreasing CDK2 and Cyclin E protein levels and increasing CDK1 and Cyclin B protein levels, and activated ATM/AMPK/mTOR axis by enhancing p-ATM/ATM, p-AMPK/AMPK and reducing p-mTOR/mTOR protein levels, eventually triggered autophagy by elevating LC3A, LC3B, Atg5, Beclin-1 mRNA levels and LC3II/LC3I, Beclin-1 protein levels and reducing P62, Dynein, mTOR mRNA levels and P62 protein level. Moreover, these changes were most apparent in the combined group. Altogether, the results reveal that autophagy caused by Mo and/or Cd may be associated with activating the DNA damage-mediated ATM/AMPK/mTOR axis in duck testes, and Mo and Cd co-exposure exacerbates these changes., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2022 Elsevier Ltd. All rights reserved.)

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-IP 3 -IP 3 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 [Ca 2+ ] c overload mainly came from intracellular Ca store. Cd caused [Ca 2+ ] mit and [Ca 2+ ] c overload with [Ca 2+ ] ER decrease, elevated Ca homeostasis related factors (GRP78, GRP94, CRT, CaN, CaMKII, and CaMKKβ) expression, PLC and IP 3 activities and IP 3 R expression, but subcellular Ca 2+ 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 [Ca 2+ ] c overload mainly originated from ER Ca 2+ release mediated by PLC-IP 3 -IP 3 R pathway, then triggered autophagy in duck renal tubular epithelial cells., (© 2022 Wiley Periodicals LLC.)

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., (Copyright © 2022 Elsevier Ltd. All rights reserved.)

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 Ca 2+ /CAM-dependent kinase IIɑ (CaMKIIɑ), calcineurin (CaN), inositol-1,4,5-trisphosphate receptor (IP 3 R), 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 Ca 2+ 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 Ca 2+ homeostasis and triggering UPR., (© 2022. The Author(s), under exclusive licence to Springer-Verlag GmbH Germany, part of Springer Nature.)

Cadmium (Cd) and excessive molybdenum (Mo) have adverse impacts on animals. However, the hepatotoxicity co-induced by Cd and Mo in ducks has not been fully elucidated. In order to explore the impacts of Cd and Mo co-exposure on pyroptosis and apoptosis by the PTEN/PI3K/AKT pathway in the livers of ducks, 40 healthy 7-day-old Shaoxing ducks ( Anas platyrhynchos ) were randomly assigned into 4 groups, and Cd or/and Mo were added to the basic diet per kilogram (kg): control group (0 mg Mo and 0 mg Cd), Mo group (100 mg Mo), Cd group (4 mg Cd), and Mo + Cd group (100 mg Mo and 4 mg Cd), with 16 weeks feed management. Results signified that Cd or/and Mo caused trace element imbalance, liver function and histomorphological abnormalities in the duck liver, and activated the PTEN/PI3K/AKT pathway through increasing PTEN mRNA and protein levels, reducing PI3K, AKT mRNA and p-AKT/AKT protein levels, which triggered pyroptosis and apoptosis via increasing Caspase-1, NLRP3, NEK7, ASC, GSDME, GSDMA, IL-1β and IL-18 mRNA levels, Caspase-1 p20, NLRP3, ASC and GSDMD protein levels, and IL-1β and IL-18 contents, and increasing Bak-1, Bax, Cyt C and Caspase-3 mRNA levels and cleaved Caspase-3/Caspase-3 protein level, and downregulating Bcl-2 mRNA level and the ratio of Bcl-2 to Bax, respectively. Overall, the results illustrate that pyroptosis and apoptosis induced by Cd or/and Mo may be associated with activating the PTEN/PI3K/AKT pathway in the livers of ducks. There may be a synergy between these two elements.

Copper (Cu) is a vital micronutrient required for numerous fundamental biological processes, but excessive Cu poses potential detrimental effects on public and ecosystem health. However, the molecular details linking endoplasmic reticulum (ER) stress and apoptosis in duck renal tubular epithelial cells have not been fully elucidated. In this study, duck renal tubular epithelial cells exposed to Cu sulfate (CuSO 4 ) (0, 100 and 200 μM) and a PERK inhibitor (GSK2606414, GSK, 1 μM) for 12 h were used to investigate the crosstalk between ER stress and apoptosis under Cu exposure. Cell and ER morphological and functional characteristics, intracellular calcium (Ca 2+ ) levels, apoptotic rates, ER stress and apoptosis-related mRNA and protein levels were examined. The results showed that excessive Cu could cause ER expansion and swelling, increase the expression levels of ER stress-associated genes (PERK, eIF2α, ATF4 and CHOP) and proteins (p-PERK and CHOP), induce intracellular Ca 2+ overload, upregulate the expression levels of apoptosis-associated genes (Bax, Bak1, Caspase9 and Caspase3) and the cleaved-Caspase3 protein, downregulate Bcl-xl and Bcl2 mRNA levels and trigger apoptosis. PERK inhibitor treatment could ameliorate the above changed factors caused by Cu. In conclusion, these findings indicate that excessive Cu could trigger ER stress via activation of the PERK/ATF4/CHOP signaling pathway and that ER stress might aggravate Cu-induced apoptosis in duck renal tubular epithelial cells., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2020 Elsevier Ltd. All rights reserved.)

The aim of this study was to investigate the crosstalk between oxidative stress and autophagy through the ROS/HO-1/NQO1 pathway caused by copper (Cu). Duck renal tubular epithelial cells were treated in Cu sulfate (CuSO 4 ) (0, 100 and 200 μM) for 12 h, and in the combination of CuSO 4 (200 μM) and reactive oxygen species (ROS) scavenger (butyl hydroxyanisole, BHA, 100 μM), or HO-1 inhibitor (zinc protoporphyrin, ZnPP, 10 μM) for 12 h. Results revealed that Cu could significantly elevate the levels of intracellular ROS, superoxide dismutase, hydrogen peroxide, malondialdehyde, glutathione, simultaneously reduce catalase and glutathione peroxidase levels, and upregulate HO-1, SOD-1, CAT, NQO1, GCLM mRNA levels and HO-1, SOD-1 protein levels. Additionally, Cu could observably increase the number of autophagosomes, acidic vesicle organelles (AVOs) and LC3 puncta; upregulate mRNA levels of mTOR, Beclin-1, ATG7, ATG5, ATG3, LC3II and protein levels of Beclin-1, LC3II/LC3I, downregulate LC3I mRNA level. Both treatments with BHA and ZnPP could significantly alleviate the changes of antioxidant indexes levels and ROS accumulation, reduce the increase of the number of autophagosomes, AVOs and LC3 puncta, and mitigate the above changed oxidative stress and autophagy related mRNA and protein levels induced by Cu. In summary, our findings indicated that excessive Cu could induce oxidative stress and autophagy by activating the ROS/HO-1/NQO1 pathway, and inhibition of HO-1 might attenuate Cu-induced oxidative stress and autophagy in duck renal tubular epithelial cells., Competing Interests: Declaration of competing interest The authors declare that there is no conflict of interest., (Copyright © 2020 Elsevier B.V. All rights reserved.)

Increasing evidence indicates autophagy and apoptosis are involved in the toxicity mechanism of heavy metals. Our previous studies showed that cadmium (Cd) could induce autophagy and apoptosis in duck kidneys in vivo, nevertheless, the interaction between them has yet to be elucidated. Herein, the cells were either treated with 3CdSO 4 ·8H 2 O (0, 1.25, 2.5, 5.0 μM Cd) or/and 3-methyladenine (3-MA) (2.5 μM) for 12 h and the indictors related autophagy and apoptosis were detected to assess the correlation between autophagy and apoptosis induced by Cd in duck renal tubular epithelial cells. The results demonstrated that Cd exposure notably elevated intracellular and extracellular Cd contents, the number of autophagosomes and LC3 puncta, up-regulated LC3A, LC3B, Beclin-1, Atg5 mRNA levels, and Beclin-1 and LC3II/LC3I protein levels, down-regulated mTOR, p62 and Dynein mRNA levels and p62 protein level. Additionally, autophagy inhibitor 3-MA decreased Beclin-1, LC3II/LC3I protein levels and increased p62 protein level. Moreover, co-treatment with Cd and 3-MA could notably elevate Caspase-3, Cyt C, Bax, and Bak-1 mRNA levels, Caspase-3 and cleaved Caspase-3 protein levels, and cell apoptotic rate as well as cell damage, decreased mitochondrial membrane potential (MMP), Bcl-2 mRNA level and the ratio of Bcl-2 to Bax compared to treatment with Cd alone. Overall, these results indicate Cd exposure can induce autophagy in duck renal tubular epithelial cells, and inhibition of autophagy might aggravate Cd-induced apoptosis through mitochondria-mediated pathway., (Copyright © 2020 Elsevier Inc. All rights reserved.)

To investigate Molybdenum (Mo) and Cadmium (Cd) co-induced the levels of autophagy-related genes via AMPK/mTOR signaling pathway in Shaoxing Duck (Anas platyrhyncha) kidney, 60 healthy 11-day-old ducks were randomly divided into 6 groups, which were treated with Mo or/and Cd at different doses on the basal diet for 120 d. Kidney samples were collected on day 120 to determine the mRNA expression levels of adenosine 5'-monophosphate (AMP)-activated protein kinase α1 (AMPKα1), mammalian target of rapamycin (mTOR), Beclin-1, autophagy-related gene-5 (Atg5), microtubule-associated protein light chain A (LC3A), microtubule-associated protein light chain B (LC3B), sequestosome-1, and Dynein by real-time quantitative polymerase chain reaction. Meanwhile, ultrastructural changes of the kidney were observed. The results indicated that the mTOR and P62 mRNA expression levels were significantly downregulated, but the Atg5 and Beclin-1 mRNA levels were remarkably upregulated in all treated groups compared to control group, and their changes were greater in joint groups. Additionally, compared to control group, the Dynein mRNA expression level was apparently downregulated in co-treated groups, the LC3B, LC3A, and AMPKα1 expression levels were dramatically upregulated in single treated groups and they were not obviously different in co-treated groups. Ultrastructural changes showed that Mo and Cd could markedly increase the number of autophagosomes. Taken together, it suggested that dietary Mo and Cd might induce autophagy via AMPK/mTOR signaling pathway in duck kidney, and it showed a possible synergistic relationship between the 2 elements., (© 2019 Poultry Science Association Inc.)

Cadmium (Cd) and high dietary intake of molybdenum (Mo) can lead to adverse reactions on animals, but the combined impacts of Mo and Cd on testicle are not clear. To investigate the co-induced toxic effects of Mo and Cd in duck testicles on the mRNA levels of heat shock proteins (HSPs), inflammatory cytokines, and apoptosis. A total of sixty 11-day-old male Shaoxing ducks (Anas platyrhyncha) were randomly divided into 6 groups and testicles were collected on day 120. The mRNA levels of HSPs (HSP60, HSP70, HSP90), inflammatory cytokines (TNF-α, NF-κB, COX-2), and apoptosis genes (Bcl-2, Bak-1, Caspase-3) were determined by real-time quantitative polymerase chain reaction (RT-qPCR), meanwhile the changes of ultrastructural were evaluated. The results showed HSPs mRNA levels were increased in high Mo and Cd groups, however, they were decreased in high dose Mo and Cd co-treated group. In all treatment groups, the mRNA levels of Bak-1 and Caspase-3 were upregulated, and Bcl-2 mRNA level was downregulated, especially in combination groups. The TNF-α, NF-κB, and COX-2 expression in co-exposure groups were higher than those in single groups. Furthermore, the ultrastructural changes showed nuclear deformation, mitochondria hyperplasia and cristaes rupture, and vacuolation in combination groups. Changes of all above factors indicated a possible synergistic relationship between the two elements, and the high expression of HSPs and inflammatory cytokines may play a role in the resistance of testicles toxicity induced by Mo or Cd or both., (© 2019 Poultry Science Association Inc.)

To investigate the toxic effects of Molybdenum (Mo) and Cadmium (Cd) on trace elements in digestive organs of Shaoxing duck (Anas platyrhyncha), 120 Shaoxing ducks were randomly divided into control group and 5 treatment groups which were treated with a commercial diet containing different dosages of Mo and Cd. On the 60th and 120th days, the beak, esophagus, glandular stomach, muscular stomach, small intestine, large intestine and feces were collected to determine contents of Mo, Cd, copper (Cu), iron (Fe), zinc (Zn) and selenium (Se), then correlation analysis was performed. The results showed that Cd content in digestive organs significantly increased in co-treated groups compared to single treated groups and Mo concentration increased in Mo-treated groups compared to control group, whereas Cu, Fe, Zn and Se concentrations in digestive organs decreased in co-treated groups. Furthermore, Cd and Mo were mainly accumulated in the small intestine and esophagus, respectively. There was a strongly positive correlation between Cd and Mo while they had negative correlation with Cu, Fe, Zn and Se, respectively. In feces, Mo and Fe contents in high dose of Mo group and high Mo combined with Cd group were significantly higher than those in control group, and Cu content in all treated groups significantly increased and Cd, Zn and Se concentrations had no difference. The results indicated that dietary Mo or/and Cd might disturb homeostasis of trace elements in digestive organs of Shaoxing duck. Moreover, the two elements presented a synergistic relationship., (Copyright © 2018. Published by Elsevier Inc.)

Cadmium (Cd) and high Molybdenum (Mo) can lead to adverse reactions on animals, but the co-induced toxicity of Mo and Cd to liver in ducks was not well understood. To investigate the co-induced toxic effects of Mo combined with Cd on mitochondrial oxidative stress and apoptosis in duck livers. 240 healthy 11-day-old ducks were randomly divided into 6 groups (control, LMo group, HMo group, Cd group, LMoCd group and HMoCd group). After being treated for 30, 60, 90 and 120 days, liver mitochondrial antioxidant indexes, ceruloplasmin (CP), metallothionein (MT), Bak-1 and Caspase-3 genes mRNA expression levels, and ultrastructural changes were evaluated. The results showed that total antioxidative capacity (T-AOC), catalase (CAT), superoxide dismutase (SOD) and xanthine oxidase (XOD) activities in experimental groups were decreased, whereas malondialdehyde (MDA) content and nitric oxide synthase (NOS) activity were increased compared with control group, and these changes of co-treated groups were more obvious in the later period of the experiment. The mRNA expression levels of CP, Bak-1 and Caspase-3 were up-regulated in experimental groups compared with control group and showed significant difference between co-treated groups and single treated groups. The mRNA expression level of MT in Cd group was higher than that in co-treated groups. Additionally, ultrastructural changes showed karyopyknosis, mitochondrial swelling, vacuolation and disruption of mitochondrial cristae in co-treated groups. Taken together, it was suggested that dietary Mo and Cd might lead to mitochondrial oxidative stress and apoptosis in duck livers, and it showed a possible synergistic relationship between the two elements., (Copyright © 2017 Elsevier Ltd. All rights reserved.)

Molybdenum (Mo) is an essential element for human beings and animals; however, high dietary intake of Mo can lead to adverse reactions. Cadmium (Cd) is one of the major transitional metals which has toxic effects in animals. To investigate the co-induced toxic effects of Mo and Cd on oxidative damage and kidney apoptosis in duck, 120 ducks were randomly divided into control group and 5 treatment groups which were treated with a commercial diet containing different dosages of Mo and Cd. Kidney samples were collected on the 60th and 120th days to determine the mRNA expression levels of ceruloplasmin (CP), metallothionein (MT), Bak-1, and Caspase-3 by quantitative RT-PCR. Additionally, we also determined the antioxidant activity indexes and contents of Mo, Cd, copper (Cu), iron (Fe), zinc (Zn), and selenium (Se) in serum. Meanwhile, ultrastructural changes of the kidney were observed. The results showed that glutathione reductase (GR) activity and CP level in serum were decreased in combination groups. In addition, the antioxidant indexes were decreased in co-treated groups compared with single treated groups. The mRNA expression levels of Bak-1 and Caspase-3 increased in co-treated groups. The mRNA expression level of CP in high-dose combination group was downregulated, while the mRNA expression of MT was upregulated except for low-dose Mo group. Additionally, in the later period the content of Cu in serum decreased in joint groups while the contents of Mo and Cd increased. In addition, ultrastructural changes showed mitochondrial crest fracture, swelling, deformed nuclei, and karyopyknosis in co-treated groups. Taken together, it was suggested that dietary Mo and Cd might lead to oxidative stress, kidney apoptosis and disturb homeostasis of trace elements in duck, and it showed a possible synergistic relationship between the two elements., (Copyright © 2017 Elsevier Inc. All rights reserved.)

The aims of this study were determining the co-induced effects of dietary Cadmium (Cd) and high intake of Molybdenum (Mo) on renal toxicity in ducks. 240 healthy 11-day-old ducks were randomly divided into 6 groups, which were treated with Mo or/and Cd at different doses added to the basal diet for 120 days. Ducks of control group were fed with basal diet, LMo and HMo groups were fed with 15mg/kg Mo and 100mg/kg Mo respectively; ducks of Cd group were provided with 4mg/kg Cd which was added into basal diet. Two combination groups were treated with 15mg/kg Mo+4mg/kg Cd and 100mg/kg Mo+4mg/kg Cd respectively. On days 30, 60, 90 and 120, the mRNA expression levels of inflammatory cytokines and contents of trace elements were detected. In addition, transmission electron microscopic examination was used for ultrastructural studies. The results indicated that the mRNA expression levels of tumor necrosis factor-α (TNF-α), nuclear factor-kappa B (NF-κB), and cyclooxygenase-2 (COX-2) showed an upward tendency in treatment groups in comparison with control group, and in the later period of the experiment it showed a significant rise in joint groups compared with the Mo and Cd group (P<0.01); the contents of copper (Cu) and iron (Fe) decreased in joint groups in the later period (P<0.05) while the contents of Mo and Cd significantly increased (P<0.01); zinc (Zn) and selenium (Se) concentration had a slight downtrend in treated groups, but showed no significant difference (P>0.05). The ultrastructural analysis showed that kidney tissues were severely injured in joint groups on day 120. These results suggested that the combination of Mo and Cd could aggravate damages to the kidney. In addition, dietary of Mo or/and Cd caused the decrease of Cu, Fe, Zn, and Se contents, inflammatory response and pathological lesions whose mechanism is somehow linked with Mo and Cd deposition in kidney., (Copyright © 2016 Elsevier Inc. All rights reserved.)

To investigate the effects of molybdenum (Mo) combined with cadmium (Cd) on the antioxidant function and the mRNA expression levels of apoptosis-related genes in duck ovaries, 60 healthy 11-old-day female ducks were treated with hexaammonium molybdate ([(NH4)6Mo7O24·4H2O]) or/and cadmium sulfate (3CdSO4·8H2O) at different doses on a daily basis for 120 days. On the 120th day, ten female birds in each group were euthanized, and the ovaries and blood were collected to determine the antioxidant indexes and the mRNA expression levels of Bak-1, Bcl-2, and caspase-3 in ovaries. In addition, ovary tissues were subjected to histopathological analysis with optical microscope. The total antioxidant capacity (T-AOC) and superoxide dismutase (SOD) activity decreased significantly (P < 0.01) in treated groups comparing with control while the nitric oxide synthase (NOS) activity increased (P < 0.01) both in ovary tissue and serum. The Bak-1 and caspase-3 expressions were upregulated while the Bcl-2 was downgraded by Mo or/and Cd. Biomolecules were affected in all metal-treated groups, whereas combined-treated animals showed greater effects. What is more, pathological damage in Mo and Cd combination treated groups was more severe. The results from the present study indicated that Mo or/and Cd caused oxidative stress and apoptosis in duck ovaries. Combination of Mo and Cd showed additive or synergistic effect leading to apoptosis and oxidative stress, and the pathway might be the mitochondrial pathway.

To investigate the chronic toxicity of molybdenum (Mo) and cadmium (Cd) on the trace elements and the mRNA expression levels of ceruloplasmin (CP) and metallothionein (MT) in duck testicles, 120 healthy 11-day-old male ducks were randomly divided into six groups with 20 ducks in each group. Ducks were treated with the diet containing different dosages of Mo or Cd. The source of Mo and Cd was hexaammonium molybdate ([(NH4)6Mo7O24·4H2O]) and cadmium sulfate (3CdSO4·8H2O), respectively, in this study. After being treated for 60 and 120 days, ten male birds in each group were randomly selected and euthanized and then testicles were aseptically collected for determining the mRNA expression levels of MT and CP, antioxidant indexes, and contents of trace elements in the testicle. In addition, testicle tissues at 120 days were subjected to histopathological analysis with the optical microscope. The results showed that co-exposure to Mo and Cd resulted in an increase in malondialdehyde (MDA) level while decrease in xanthine oxidase (XOD) and catalase (CAT) activities. The mRNA expression level of MT gene was upregulated while CP was decreased in combination groups. Contents of Mo, copper (Cu), iron (Fe), and zinc (Zn) decreased in combined groups while Cd increased in Cd and combined groups at 120 days. Furthermore, severe congestion, low sperm count, and malformation were observed in low dietary of Mo combined with Cd group and high dietary of Mo combined with Cd group. Our results suggested that Mo and Cd might aggravate testicular degeneration synergistically through altering the mRNA expression levels of MT and CP, increasing lipid peroxidation through inhibiting related enzyme activities and disturbing homeostasis of trace elements in testicles. Interaction of Mo and Cd may have a synergistic effect on the testicular toxicity.

Molybdenum (Mo) is an essential element for human beings and animals; however, high dietary intake of Mo can lead to adverse reactions. Cadmium (Cd) is harmful to health. To investigate the toxicity of Mo combined with Cd in duck kidneys, 240 ducks were randomly divided into six groups and treated with a commercial diet containing Mo, Cd or Mo combined with Cd. Kidneys were collected on days 30, 60, 90 and 120 for determining the expression of heat shock proteins (HSPs), including HSP60, HSP70 and HSP90 in the kidney through quantitative RT-PCR. We also determined the antioxidant activity indexes in the kidney mitochondria. Moreover, kidney tissues at 120 days were subjected to histopathological analysis with the optical microscope. The results indicated that the expression of HSPs was highly significantly (P < 0.01) upregulated in the kidneys of the combination groups and the Cd group. Exposure to Cd and a high dose of Mo decreased the total antioxidative capacity and the activity of xanthine oxidase, while malondialdehyde levels and the activity of nitric oxide synthase increased compared with those of the control groups in the kidney mitochondria. This was particularly evident at 90 and 120 days. Histopathological lesions included congestion and bleeding in the renal interstitium, swelling of the distal convoluted tubule epithelial cells, granular degeneration and blister degeneration in the renal tubular epithelial cells. These results suggest that a combination of Mo and Cd leads to greater tissue damage and has a synergistic effect on kidney damage. Oxidative damage of kidney mitochondria may be a potential nephrotoxicity mechanism of molybdenum and cadmium, and the high expression of HSPs may play a role in the resistance of kidney toxicity induced by Mo and Cd.

Excess molybdenum (Mo) is harmful to animals, but its nephrotoxicity has not been comprehensively explained. To appraise the influences of excess Mo on Ca homeostasis and apoptosis via PLC/IP3/IP3R axis, primary duck renal tubular epithelial cells were exposed to 480 μM and 960 μM Mo, and joint of 960 μM Mo and 10 μM 2‐APB or 0.125 μM U‐73122 for 12 h (U‐73122 pretreated for 1 h), respectively. The data revealed that the increment of [Ca2+]c induced by Mo mainly originated from intracellular Ca storage. Mo exposure reduced [Ca2+]ER, elevated [Ca2+]mit, [Ca2+]c, and the expression of Ca homeostasis‐related factors (Calpain, CaN, CRT, GRP94, GRP78 and CaMKII). 2‐APB could effectively reverse subcellular Ca2+ redistribution by inhibiting IP3R, which confirmed that [Ca2+]c overload induced by Mo originated from ER. Additionally, PLC inhibitor U‐73122 remarkably mitigated the change, and dramatically reduced the number of apoptotic cells, the expression of Bak‐1, Bax, cleaved‐Caspase‐3/Caspase‐3, and notably increased the expression of Bcl‐xL, Bcl‐2, and Bcl‐2/Bax ratio. Overall, the results confirmed that the Ca2+ liberation of ER via PLC/IP3/IP3R axis was the main cause of [Ca2+]c overload, and then stimulated apoptosis in duck renal tubular epithelial cells. [ABSTRACT FROM AUTHOR]

High molybdenum (Mo) and cadmium (Cd) are harmful to the body, but pulmonary toxicity induced by Mo and Cd co‐exposure is unknown. To assess the combined impacts of Mo and Cd on fibrosis through M1 polarization in the lung of ducks, 80 healthy 8‐day‐old Shaoxing ducks (Anas platyrhyncha) were randomly assigned to 4 groups and fed with containing unequal doses of Mo or/and Cd diet. Lung tissues were collected on the 16th week. Results indicated that Mo or/and Cd significantly increased their contents in the lungs, and led to trace elements disorder and histological abnormality, and oxidative stress accompanied by promoting contents of H2O2 and MDA and decreasing activities of T‐SOD, GSH‐Px, and CAT, then activated the TLR4/NF‐κB/NLRP3 pathway accompanied by upregulating Caspase‐1, ASC, IL‐18, IL‐1β, TLR4, NF‐κB, and NLRP3 expression levels, and disrupted M1/M2 balance to divert toward M1, which evoked the TGF‐β/Smad2/3‐mediated fibrosis by elevating TGF‐β1, Smad2, Smad3, COL1A1, α‐SMA, and MMP2 expression levels, and decreasing Smad7 and TIMP2 expression levels. The changes of the combined group were most obvious. To sum up, the research demonstrated that Mo or/and Cd may cause macrophages to polarize toward M1 by oxidative stress‐mediated the TLR4/NF‐κB/NLRP3 pathway, then result in fibrosis through the TGF‐β1/Smad2/3 pathway in duck lungs. Mo and Cd may worsen lung damage. [ABSTRACT FROM AUTHOR]

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‐IP3R 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 CaMKKβ) expression, PLC and IP3 activities and IP3R 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‐IP3R pathway, then triggered autophagy in duck renal tubular epithelial cells. [ABSTRACT FROM AUTHOR]

Excess molybdenum (Mo) and cadmium (Cd) are widespread environmental and industrial metal pollutants. To evaluate the combined effects of Mo and Cd on calcium homeostasis and autophagy in duck kidneys. 160 healthy 7-day-old ducks (Anas platyrhyncha) were randomized into 4 groups and given to a basic diet, adding various doses of Mo or/and Cd for 16 weeks. On the 4th, 8th, 12th and 16th weeks, kidney tissues were collected. The study exhibited that Mo or/and Cd caused histological abnormality, reduced the activities of Ca2+ ATPase, Mg2+ ATPase, Na+-K+ ATPase and Ca2+-Mg2+ ATPase, K and Mg contents, and increased Na and Ca contents, upregulated CaMKKβ, CaMKIIɑ, CaN, IP 3 R, GRP78, GRP94, CRT mRNA levels and CaMKIIɑ, CaN, IP 3 R protein levels. Moreover, exposure to Mo or/and Cd notably promoted the amount of autophagosomes and LC3II immunofluorescence, upregulated AMPKα1, ATG5, Beclin-1, LC3A, LC3B mRNA levels and Beclin-1, LC3II/LC3I protein levels, downregulated mTOR, Dynein, P62 mRNA levels and P62 protein level. The changes of above indicators in combined group were more obvious. Overall, the results suggest that Mo and Cd co-exposure may can synergistically induce nephrotoxicity via causing calcium homeostasis disorder and autophagy in ducks. [Display omitted] • The co-toxicity of Mo and Cd was assessed in duck kidneys. • Mo and Cd could synergistically induce Ca2+ homeostasis imbalance. • Mo and Cd could synergistically induce Ca2+ homeostasis imbalance and autophagy. [ABSTRACT FROM AUTHOR]

Growing evidences reveal that Nrf2-mediated antioxidant defense response and mitophagy are involved in the toxic mechanism of heavy metals, but the effects of molybdenum (Mo) and cadmium (Cd) co-exposure on Nrf2-mediated antioxidant defense response and mitophagy in duck hypothalamus have yet to be elucidated. Herein, 40 healthy 7-day-old ducks were randomly assigned to 4 groups and fed diets containing different doses of Mo or/and Cd for 16 weeks, respectively. The data demonstrated that Mo or/and Cd notably elevated their contents in hypothalamus, decreased Cu, Fe, Zn and Se contents, caused pathological damage and oxidative stress accompanied by elevating MDA content and reducing CAT, T-AOC, T-SOD, GSH-Px activities. Moreover, Mo or/and Cd not only restrained Nrf2 pathway by decreasing Nrf2, HO-1, NQO1, GST, CAT, SOD1, GCLM mRNA expression levels and Nrf2 protein expression level, but also disturbed mitochondrial dynamics and triggered PINK1/Parkin-mediated mitophagy by enhancing MFF, PINK1, Parkin, Bnip3, LC3A, LC3B mRNA expression levels and PINK1, Parkin, LC3B-II/LC3B-I protein expression levels, inhibiting Mfn1, Mfn2, OPA1, P62 mRNA expression levels and P62 protein expression level, and facilitating the colocalization between LC3 and HSP60. The changes of above factors were most remarkable under Mo and Cd co-treatment. Overall, the results elucidate that Mo and Cd can synergistically inhibit Nrf2-mediated antioxidant defense response and activate PINK1/Parkin pathway-dependent mitophagy in duck hypothalamus, whose mechanism is somehow related to Mo and Cd accumulation. [Display omitted] • The joint toxicity of Mo and Cd was evaluated in duck hypothalamus. • Mo or/and Cd caused the imbalance of trace elements and oxidative stress. • Mo or/and Cd inhibited Nrf2-mediated antioxidant defense response. • Mo or/and Cd restrained Nrf2 signaling pathway and induced mitophagy. • Mo and Cd may have a synergistic effect. [ABSTRACT FROM AUTHOR]

Excessive molybdenum (Mo) and cadmium (Cd) cause toxic effects on animals, but their joint effects on pyroptosis in kidney of ducks remain unclear. 160 healthy 7-day-old ducks were randomly divided into four groups which were fed with basal diet containing different dosages of Mo or/and Cd for 16 weeks. On the 4th, 8th, 12th and 16th weeks, kidney tissue and serum were collected. The results showed that Mo or/and Cd could significantly elevate their contents in kidney, disturb the homeostasis of trace elements, cause renal function impairment and histological abnormality, and oxidative stress as accompanied by increasing hydrogen peroxide (H 2 O 2) and malondialdehyde (MDA) concentrations and decreasing glutathione peroxidase (GSH-Px), catalase (CAT) and total-superoxide dismutase (T-SOD) activities. Simultaneously, Mo or/and Cd could markedly increase interleukin-1β (IL-1β), interleukin-18 (IL-18) contents and the expression levels of pyroptosis-related genes (NOD-like receptor protein-3 (NLRP3), Caspase-1, apoptosis-associated speck-like protein (ASC), NIMA-related kinase 7 (NEK7), Gasdermin A (GSDMA), Gasdermin E (GSDME), IL-1β and IL-18) and proteins (NLRP3, Caspase-1 p20, ASC and Gasdermin D (GSDMD)). Moreover, the changes of above these indicators were more obvious in combined group. Taken together, the results illustrate that Mo and Cd might synergistically lead to oxidative stress and induce pyroptosis via NLRP3/Caspase-1 pathway, whose mechanism is somehow related to Mo and Cd accumulation in duck kidneys. Excess molybdenum (Mo) or/and cadmium (Cd) exposure can cause trace elements imbalance and oxidative stress in duck kidneys, which ultimately lead to histological abnormality, and pyroptosis by NOD-like receptor protein-3 (NLRP3)/Caspase-1 pathway. Moreover, the two metals may have a synergistic effect. [Display omitted] • The joint effects of molybdenum (Mo) and cadmium (Cd) on pyroptosis were assessed in duck kidney. • Mo and Cd disturbed the homeostasis of trace elements. • Mo and Cd caused oxidative stress and damage to kidney. • Mo and Cd caused pyroptosis by NOD-like receptor protein-3 (NLRP3)/Caspase-1 axis. • Mo and Cd exhibited synergic interactions. [ABSTRACT FROM AUTHOR]

Pyroptosis and autophagy are two different biological processes that determine cell fates. Our previous studies revealed that pyroptosis and autophagy were involved in cytotoxicity co-induced by molybdenum (Mo) and cadmium (Cd) in duck renal tubular epithelial cells, but crosstalk between them is unclear. Hence, the cells were treated with 500.0 μM Mo, 4.0 μM Cd, 10.0 μM Z-YVAD-fluoromethylketone (YVAD), 2.5 μM 3-methyladenine (3-MA) and 10.0 μM chloroquine (CQ) alone or in combination for 12 h (CQ for the last 4 h). Under Mo and Cd co-stress, data evidenced that YVAD addition decreased the number of autophagosomes, LC3 puncta, and AMPKα-1, Atg5, Beclin-1, LC3A, LC3B mRNA levels and LC3-II/LC3-I, Beclin-1 protein levels, and increased p62 expression levels. Besides, both 3-MA and CQ addition increased NLRP3, Caspase-1, NEK7, ASC, GSDMA, GSDME, IL-1β, IL-18 mRNA levels, NLRP3, Caspase-1 p20, ASC, GSDMD protein and ROS levels, and NO, LDH, IL-1β, IL-18 releases. Collectively, our results revealed that pyroptosis and autophagy co-induced by Mo and Cd were interrelated in duck renal tubular epithelial cells, and inhibiting pyroptosis might attenuate Mo and Cd co-induced autophagy, but inhibiting autophagy might promote Mo and Cd co-induced pyroptosis. [Display omitted] • The co-toxicity of Mo and Cd was assessed in duck renal tubular epithelial cells. • Crosstalk between pyroptosis and autophagy co-induced by Mo and Cd was explored. • Autophagy inhibitor both 3-MA and CQ might promote pyroptosis co-induced by Mo and Cd. • Pyroptosis inhibitor YVAD might attenuate autophagy co-induced by Mo and Cd. [ABSTRACT FROM AUTHOR]

Cadmium (Cd) is an occupational and environmental pollutant, which mainly causes nephrotoxicity by damaging renal proximal tubular cells. To evaluate the effects of Cd on pyroptosis and the relationship between pyroptosis and apoptosis in duck renal tubular epithelial cells, the cells were cultured with 3CdSO 4 ·8H 2 O (0, 2.5, 5.0, or 10.0 μM Cd), N-acetyl-L-cysteine (NAC) (100.0 μM), Z-YVAD-FMK (10.0 μM) or the combination of Cd and NAC or Z-YVAD-FMK for 12 h, and then cytotoxicity was assessed. The results evidenced that Cd significantly increased the releases of interleukin-18 (IL-18) and interleukin-1β (IL-1β), lactate dehydrogenase (LDH) and nitric oxide (NO), relative conductivity and cellular reactive oxygen species (ROS) level. Simultaneously, Cd also markedly upregulated NLRP3, Caspase-1, ASC, NEK7, IL-1β and IL-18 mRNA levels and NLRP3, Caspase-1 p20, GSDMD and ASC protein levels. Additionally, NAC notably improved the changes of above indicators induced by Cd. Combined treatment with Cd and Z-YVAD-FMK remarkably elevated Bcl-2 mRNA and protein levels, inhibited p53, Bax, Bak-1, Cyt C, Caspase-9 and Caspase-3 mRNA levels and p53, Bax, Bak-1, Caspase-9/cleaved Caspase-9 and Caspase-3/cleaved Caspase-3 protein levels, increased mitochondrial membrane potential (MMP), decreased apoptosis ratio and cell damage compared to treatment with Cd alone. Taken together, Cd exposure induces duck renal tubular epithelial cell pyroptosis through ROS/NLRP3/Caspase-1 signaling pathway, and inhibiting Caspase-1 dependent pyroptosis attenuates Cd-induced apoptosis. Image 1 • Cadmium (Cd) toxicity was evaluated in duck renal tubular epithelial cells. • Cd could induce pyroptosis via ROS/NLRP3/Caspase-1 pathway. • N-acetyl-L-cysteine (NAC) could inhibit pyroptosis induced by Cd. • Inhibiting Caspase-1-dependent pyroptosis might weaken Cd induced-apoptosis. [ABSTRACT FROM AUTHOR]

Cadmium (Cd) and excess molybdenum (Mo) are harmful to animals, but the combined nephrotoxic mechanism of Cd and Mo in duck remains poorly elucidated. To assess joint effects of Cd and Mo on pyroptosis via ROS/PTEN/PI3K/AKT axis in duck renal tubular epithelial cells, cells were cultured with 3CdSO 4 ·8H 2 O (4.0 μM), (NH 4) 6 Mo 7 O 24 ·4H 2 O (500.0 μM), MCC950 (10.0 μM), BHA (100.0 μM) and combination of Cd and Mo or Cd, Mo and MCC950 or Cd, Mo and BHA for 12 h, and the joint cytotoxicity was explored. The results manifested that toxicity of non-equitoxic binary mixtures of Mo and Cd exhibited synergic interaction. Mo or/and Cd elevated ROS level, PTEN mRNA and protein levels, and decreased PI3K, AKT and p-AKT expression levels. Simultaneously, Mo or/and Cd upregulated ASC, NLRP3, NEK7, Caspase-1, GSDMA, GSDME, IL-18 and IL-1β mRNA levels and Caspase-1 p20, NLRP3, ASC, GSDMD protein levels, increased the percentage of pyroptotic cells, LDH, NO, IL-18 and IL-1β releases as well as relative conductivity. Moreover, NLRP3 inhibitor MCC950 and ROS scavenger BHA could ameliorate the above changed factors induced by Mo and Cd co-exposure. Collectively, our results reveal that combination of Mo and Cd synergistically cause oxidative stress and trigger pyroptosis via ROS/PTEN/PI3K/AKT axis in duck tubular epithelial cells. Image 1 • The joint toxicity of Mo and Cd was assessed in duck renal tubular epithelial cells. • There was a synergistic effect between non-equitoxic binary mixture of Mo and Cd. • Mo or/and Cd induced pyroptosis via ROS/PTEN/PI3K/AKT axis. • BHA inhibited pyroptosis co-induced by Mo and Cd via ROS/PTEN/PI3K/AKT axis. [ABSTRACT FROM AUTHOR]

Excess molybdenum (Mo) is harmful to the body, and the kidney is the vital target organ for Mo exposure. This study focused on the impacts of excess Mo on pyroptosis and the relationship between pyroptosis and apoptosis in kidney. The duck renal tubular epithelial cells were treated with (NH 4) 6 Mo 7 O 24 ·4H 2 O (0, 480, 720 and 960 μM Mo), N-acetyl- L -cysteine (NAC) (100 μM), Z-YVAD-fluoromethylketone (YVAD) (10 μM) and the combination of Mo and NAC or YVAD for 12 h. The LDH release and IL-1β, IL-18 contents of cell supernatant were detected by LDH and ELISA kits. The MMP and ROS level were measured using MMP and ROS kits by flow cytometry. The apoptotic rate of cell was detected by AO/EB counterstaining. Pyroptosis and apoptosis-related factors mRNA and protein levels were assayed by real-time qPCR and western blot, respectively. Excessive Mo markedly increased LDH, IL-18, IL-1β releases and induced overproduction of ROS, pyroptosis-related factors mRNA and protein levels. NAC and YVAD dramatically decreased pyroptosis induced by Mo. Simultaneously, YVAD significantly changed apoptosis-related factors mRNA and protein levels, and reduced cell apoptotic rate. Excessive Mo exposure can induce pyroptosis by the ROS/NLRP3/Caspase-1 pathway in duck renal tubular epithelial cells, and restraining pyroptosis of Caspase-1 dependence might weaken excess Mo-induced apoptosis. The study provides theoretical basis for excess Mo exposure nephrotoxic researches on waterfowl and the interplay between pyroptosis and apoptosis highlights a new sight into the mechanism of Mo-induced nephrotoxicity. ga1 • Toxicity of excess molybdenum (Mo) was assessed in duck renal tubular epithelial cells. • Excess Mo could induce pyroptosis via ROS/NLRP3/Caspase-1 pathway. • N-acetyl- L -cysteine (NAC) could inhibit pyroptosis induced by excess Mo. • Inhibiting Caspase-1-dependent pyroptosis might weaken excess Mo induced-apoptosis. [ABSTRACT FROM AUTHOR]

Excessive molybdenum (Mo) and cadmium (Cd) have toxic effects on animals. However, hepatotoxicity co-induced by Mo and Cd in ducks is still unclear. To evaluate the effects of Cd and Mo co-exposure on autophagy by nuclear factor erythroid 2-related factor 2 (Nrf2)-mediated antioxidant defense and endoplasmic reticulum stress (ERS) in duck livers, 40 healthy 7-day-old ducks were randomly assigned to 4 groups and fed diets containing different doses of Mo and/or Cd for 16 weeks, respectively. The results verified that Mo and/or Cd induced oxidative stress via decreasing glutathione peroxidase (GSH-Px), catalase (CAT), and total-superoxide dismutase (T-SOD) activities and increasing hydrogen peroxide (H 2 O 2) and malondialdehyde (MDA) concentrations; inhibited Nrf2 axis by downregulating the pathway-related genes and proteins expression levels, and activated ERS through upregulating the protein kinase RNA-like endoplasmic reticulum kinase (PERK)/eukaryotic initiation factor 2a (eIF2a), inositol-requiring enzyme 1 (IRE1) and activating transcription factor 6 (ATF6) pathway-related genes and proteins expression levels, which triggered autophagy via increasing autophagosomes, light chain 3 (LC3) puncta, LC3A, LC3B, autophagy-related gene 5 (Atg5), Bcl-2-interacting protein (Beclin-1) mRNA levels and Beclin-1, microtubule-associated protein light chain 3 II/I (LC3II/LC3I) protein levels, decreasing Dynein, p62, mammalian target of rapamycin (mTOR) mRNA levels and p62 protein level. Additionally, the changes in Mo and Cd group were the most obvious. Briefly, our study reveals that autophagy induced by Mo and/or Cd may be associated with the activation of crosstalk between Nrf2-mediated antioxidant defense response and ERS in duck livers. Mo and Cd may aggravate toxic damage to the liver. Excess molybdenum (Mo) and/or cadmium (Cd) exposure can induce oxidative stress, inhibit nuclear factor erythroid 2-related factor 2 (Nrf2)-mediated antioxidant defense response and activate endoplasmic reticulum stress (ERS), which triggers autophagy in duck livers. Moreover, Mo and Cd may aggravate toxic damage to the liver. [Display omitted] • Nrf2 is the abbreviation of nuclear factor erythroid 2-related factor 2. • ERS is the abbreviation of endoplasmic reticulum stress. • Molybdenum (Mo) and cadmium (Cd) exposure inhibited Nrf2 axis and activated ERS. • Mo and Cd caused autophagy was related to the crosstalk between Nrf2 axis and ERS. • Mo and Cd may aggravate toxic damage to the liver of ducks. [ABSTRACT FROM AUTHOR]

• The joint toxic effects of Mo and Cd were evaluated in duck renal tubular epithelial cells. • Mo or/and Cd induced oxidative stress by generating excessive ROS in duck renal tubular epithelial cells. • Apoptosis occurred in duck renal tubular epithelial cells treated with Mo or/and Cd. • Mo or/and Cd induced apoptosis through the mitochondrial-mediated pathway in duck renal tubular epithelial cells. • There is a synergistic effect between Mo and Cd induced cytotoxicity in duck renal tubular epithelial cells. High doses of molybdenum (Mo) and cadmium (Cd) cause adverse reactions on animals, but the joint toxic effects of Mo and Cd on duck renal tubular epithelial cells are not fully illustrated. To investigate the combined effects of Mo and Cd on oxidative stress and mitochondrial apoptosis in primary duck renal tubular epithelial cells, the cells were either treated with (NH 4) 6 Mo 7 O 24 ·4H 2 O (480, 960 μM Mo), 3CdSO 4 ·8H 2 O (2.5, 5.0 μM Cd) or combination of Mo and Cd for 12 h, and then the joint cytotoxicity was evaluated. The results demonstrated that Mo or/and Cd exposure could induce release of intracellular lactate dehydrogenase, reactive oxygen species generation, acidification, increase levels of malondialdehyde and [Ca2+i, decrease levels of glutathione, glutathione peroxidase, catalase, superoxide dismutase, total antioxidant capacity, Na+/K+-ATPase, Ca2+-ATPase, and mitochondrial membrane potential; upregulate mRNA levels of Caspase-3, Bak-1, Bax, and cytochrome C, inhibit Bcl-2 mRNA level, and induce cell apoptosis in a dose-dependent manner. Furthermore, the changes of these indicators in co-treated groups were more remarkable. The results indicated that exposure to Mo or/and Cd could induce oxidative stress and apoptosis via the mitochondrial pathway in duck renal tubular epithelial cells and the two metals may have a synergistic effect. [ABSTRACT FROM AUTHOR]