Persistent activation of Nrf2 in a p62-dependent non-canonical manner aggravates lead-induced kidney injury by promoting apoptosis and inhibiting autophagy

Lysosomal dysfunction-derived autophagy impairment of gingival epithelial cells in diabetes-associated periodontitis with altered protein acetylation

Diabetes-associated periodontitis (DP) presents severe inflammation and resistance to periodontal conventional treatment, presenting a significant challenge in clinical management. In this study, we investigated the underlying mechanism driving the hyperinflammatory response in gingival epithelial cells (GECs) of DP patients. Our findings indicate that lysosomal dysfunction under high glucose conditions leads to the blockage of autophagy flux, exacerbating inflammatory response in GECs. Single-cell RNA sequencing and immunohistochemistry analyses of clinical gingival epithelia revealed dysregulation in the lysosome pathway characterized by reduced levels of lysosome-associated membrane glycoprotein 2 (LAMP2) and V-type proton ATPase 16 kDa proteolipid subunit c (ATP6V0C) in subjects with DP. In vitro stimulation of human gingival epithelial cells (HGECs) with a hyperglycemic microenvironment showed elevated release of proinflammatory cytokines, compromised lysosomal acidity and blocked autophagy. Moreover, HGECs with deficiency in ATP6V0C demonstrated impaired autophagy and heightened inflammatory response, mirroring the effects of high glucose stimulation. Proteomic analysis of acetylation modifications identified altered acetylation levels in 28 autophagy-lysosome pathway-related proteins and 37 sites in HGECs subjected to high glucose stimulation or siATP6V0C. Overall, our finding highlights the pivotal role of lysosome impairment in autophagy obstruction in DP and suggests a potential impact of altered acetylation of relevant proteins on the interplay between lysosome dysfunction and autophagy blockage. These insights may pave the way for the development of effective therapeutic strategies against DP.

Molybdenum and cadmium co-induce apoptosis and ferroptosis through inhibiting Nrf2 signaling pathway in duck (Anas platyrhyncha) testes

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.

Melatonin alleviates glyphosate-induced testosterone synthesis inhibition via targeting mitochondrial function in roosters

Glyphosate (GLY) is a widely used herbicide that has been revealed to inhibit testosterone synthesis in humans and animals. Melatonin (MET) is an endogenous hormone that has been demonstrated to promote mammalian testosterone synthesis via protecting mitochondrial function. However, it remains unclear whether MET targets mitochondria to alleviate GLY-inhibited testosterone synthesis in avian. In this study, an avian model using 7-day-old rooster upon chronic exposure to GLY with the treatment of MET was designed to clarify this issue. Data first showed that GLY-induced testicular Leydig cell damage, structural damage of the seminiferous tubule, and sperm quality decrease were mitigated by MET. Transcriptomic analyses of the testicular tissues revealed the potentially critical role of mitophagy and steroid hormone biosynthesis in the process of MET counteracting GLY-induced testicular damage. Also, validation data demonstrated that the inhibition of testosterone synthesis due to GLY-induced mitochondrial dynamic imbalance and concomitant Parkin-dependent mitophagy activation is alleviated by MET. Moreover, GLY-induced oxidative stress in serum and testicular tissue were significantly reversed by MET. In summary, these findings demonstrate that MET effectively ameliorates GLY-inhibited testosterone synthesis by inhibiting mitophagy activation, which provides a promising remedy for the application of MET as a potential therapeutic agent to antagonize reproductive toxicity induced by GLY and similar contaminants.

Arsenic and chromium induced hepatotoxicity in zebrafish (Danio rerio) at environmentally relevant concentrations: Mixture effects and involvement of Nrf2-Keap1-ARE pathway

Arsenic (As) and chromium (Cr), two well-known cytotoxic and carcinogenic metals are reported to coexist in industrial effluents and groundwater. Their individual toxicities have been thoroughly studied but the combined effects, especially the mechanism of toxicity and cellular stress response remain unclear. Considering co-exposure as a more realistic scenario, current study compared the individual and mixture effects of As and Cr in the liver of zebrafish (Danio rerio). Fish were exposed to environmentally relevant concentrations of As and Cr for 15, 30 and 60 days. ROS generation, biochemical stress parameters like lipid peroxidation, reduced glutathione content, catalase activity and histological alterations were studied. Results showed increase in ROS production, MDA content and GSH level; and vicissitude in catalase activity as well as altered histoarchitecture, indicating oxidative stress conditions after individual and combined exposure of As and Cr which were additive in nature. This study also included the expression of Nrf2, the key regulator of antioxidant stress responses and its nuclear translocation. Related antioxidant and xenobiotic metabolizing enzyme genes like keap1, nqo1, ho1, mnsod and cyp1a were also studied. Overall results indicated increased nrf2, nqo1, ho1, mnsod expression at all time points and increased cyp1a expression after 60 days exposure. Emphasizing on the Nrf2-Keap1 pathway, this study exhibited additive or sometimes synergistic effects of As and Cr in zebrafish liver.

Resveratrol alleviates imidacloprid-induced mitochondrial apoptosis, necroptosis, and immune dysfunction in chicken lymphocyte lines by inhibiting the ROS/MAPK signaling pathway

Imidacloprid (IMI) is a neonicotinoid insecticide with the highest global market share, and IMI exposure in the environment can negatively affect many nontarget organisms (a general term for organisms affected by drugs other than target organisms). Resveratrol (RSV), a non-flavonoid polyphenolic organic compound derived from peanuts, grapes, and other plants, has anti-inflammatory and antioxidant effects. It is currently unclear how RSV protects against cell damage caused by IMI. Therefore, we established an experimental model of chicken lymphocyte lines exposed to 110 μg/mL IMI and/or 0.5 μM RSV for 24 h. According to the experimental results, IMI markedly raised intracellular reactive oxygen species levels and diminished the activity of the cellular antioxidant enzymes (CAT, SOD, and GPx), leading to MDA accumulation and decreased T-AOC. JNK, ERK, and P38, the essential components of the mitogen-activated protein kinase (MAPK) signaling pathway, were also expressed more when IMI was present. Additionally, IMI resulted in upregulation of mitochondrial apoptosis (Caspase 3, Caspase 9, Bax, and Cyt-c) and necroptosis (Caspase 8, RIPK1, RIPK3, and MLKL) related factors expression, downregulation of Bcl-2 expression, induction of upregulation of cytokine IL-6 and TNF-α expression, and downregulation of IFN-γ expression. The combined treatment of RSV and IMI significantly reduced cellular oxidative stress levels, inhibited the MAPK signaling pathway, and alleviated IMI-induced mitochondrial apoptosis, necroptosis, and immune dysfunction. To summarize, RSV antagonized IMI-induced mitochondrial apoptosis, necroptosis, and immune dysfunction in chicken lymphocyte lines by inhibiting the ROS/MAPK signaling pathway.

Melatonin-Derived Carbon Dots with Free Radical Scavenging Property for Effective Periodontitis Treatment via the Nrf2/HO-1 Pathway

Periodontitis is a chronic inflammatory disease closely associated with reactive oxygen species (ROS) involvement. Eliminating ROS to control the periodontal microenvironment and alleviate the inflammatory response could potentially serve as an efficacious therapy for periodontitis. Melatonin (MT), renowned for its potent antioxidant and anti-inflammatory characteristics, is frequently employed as an ROS scavenger in inflammatory diseases. However, the therapeutic efficacy of MT remains unsatisfactory due to the low water solubility and poor bioavailability. Carbon dots have emerged as a promising and innovative nanomaterial with facile synthesis, environmental friendliness, and low cost. In this study, melatonin-derived carbon dots (MT-CDs) were successfully synthesized via the hydrothermal method. The MT-CDs have good water solubility and biocompatibility and feature excellent ROS-scavenging capacity without additional modification. The in vitro experiments proved that MT-CDs efficiently regulated intracellular ROS, which maintained mitochondrial homeostasis and suppressed the production of inflammatory mediators. Furthermore, findings from the mouse model of periodontitis indicated that MT-CDs significantly inhibited the deterioration of alveolar bone and reduced osteoclast activation and inflammation, thereby contributing to the regeneration of damaged tissue. In terms of the mechanism, MT-CDs may scavenge ROS, thereby preventing cellular damage and the production of inflammatory factors by regulating the nuclear factor erythroid 2-related factor 2 (Nrf2)/heme oxygenase-1 (HO-1) pathway. The findings will offer a vital understanding of the advancement of secure and effective ROS-scavenging platforms for more biomedical applications.

Endoplasmic reticulum stress-induced NLRP3 inflammasome activation as a novel mechanism of polystyrene microplastics (PS-MPs)-induced pulmonary inflammation in chickens

Microplastics (MPs) have attracted growing attention worldwide as an increasingly prevalent environmental pollutant. In addition, chicken meat is currently the most widely consumed kind of poultry in the global market. Consumer demand for chicken is on the rise both at home and abroad. As a result, the safety of chicken raising has also received significant attention. The lungs play an essential role in the physiological activities of chickens, and they are also the most vulnerable organs. Lung injury is difficult to repair after the accumulation of contaminants, and the mortality rate is high, which brings huge economic losses to farmers. The research on the toxicity of MPs has mainly focused on the marine ecosystem, while the mechanisms of toxicity and lung damage in chickens have been poorly studied. Thus, this study explored the effects of exposure to polystyrene microplastics (PS-MPs) at various concentrations for 42 d on chicken lungs. PS-MPs could cause lung pathologies and ultrastructural abnormalities, such as endoplasmic reticulum (ER) swelling, inflammatory cell infiltration, chromatin agglutination, and plasma membrane rupture. Simultaneously, PS-MPs increased the expression of genes related to the heat shock protein family (Hsp60, Hsp70, and Hsp90), ER stress signaling (activating transcription factor 6 (ATF6), ATF4, protein kinase RNA-like ER kinase (PERK), and eukaryotic translation initiation factor 2 subunit α (eIF2α)), pyroptosis-related genes (NOD-‍, LRR- and pyrin domain-containing protein 3 (NLRP3), apoptosis-associated speck-like protein containing a caspase recruitment domain (ASC), interleukin-1β (IL-1β), cysteinyl aspartate-specific proteinase 1 (Caspase1), and gasdermin-D (GSDMD)), and the inflammatory signaling pathway (nuclear factor-‍κB (NF-‍κB), inducible nitric oxide synthase (iNOS), and cyclooxygenase-2 (COX-2)). The above results showed that PS-MP exposure could result in lung stress, ER stress, pyroptosis, and inflammation in broilers. Our findings provide new scientific clues for further research on the mechanisms of physical health and toxicology regarding MPs.

Cadmium neurotoxicity and therapeutic strategies

Cadmium (Cd) is a multitarget, carcinogenic, nonessential environmental pollutant. Due to its toxic effects at very low concentrations, lengthy biological half-life, and low excretion rate, exposure to Cd carries a concern. Prolonged exposure to Cd causes severe injury to the nervous system of both humans and animals. Nevertheless, the precise mechanisms responsible for the neurotoxic effects of Cd have yet to be fully elucidated. The accurate chemical mechanism potentially entails the destruction of metal-ion homeostasis, inducing oxidative stress, apoptosis, and autophagy. Here we review the evidence of the neurotoxic effects of Cd and corresponding strategies to protect against Cd-induced central nervous system injury.

Kaempferol improves Pb-induced cognitive impairments via inhibiting autophagy

Kaempferol (Kam) is a flavonoid antioxidant found in fruits and vegetables, which was discovered as neuroprotective antioxidants. Lead (Pb), an environmental pollution, could induce learning and memory deficits. Nevertheless, little is known about the mechanisms underlying Kam actions in Pb-induced learning and memory deficits. In this study, we investigated the effects of Kam on Pb-induced cognitive deficits. Pb-exposed rats were treated with 50 mg/kg Kam from postnatal day (PND) 30 to PND 60. Then, Y-maze and Morris water maze have been used to detect the spatial memory in all groups of rats. Hematoxylin and eosin (HE) staining and Nissl staining were used to analyze the neuronal structure damages. The results found Kam treatment improved the learning and memory ability and alleviated hippocampal neuronal pathological damages. Besides, Kam could significantly reverse the synaptic transmission related protein expression including PSD95 and NMDAR2B. Further research found that Kam downregulated autophagy markers, P62, ATG5, Beclin1, and LC3-II. Furthermore, 3-MA, autophagy inhibitor, increased the levels of NMDAR2B and PSD95 in Pb-induced PC12 cells, indicating Kam alleviated Pb-induced neurotoxicity through inhibiting autophagy activation. Our results showed that Kam could ameliorate Pb-induced cognitive impairments and neuronal damages by decreasing Pb-induced excess autophagy accumulation.

New Insights into Decabromodiphenyl Ether-Induced Splenic Injury in Chickens: Involvement of ROS-Mediated Endoplasmic Reticulum Stress Pathway Triggering Autophagy and Apoptosis

Decabromodiphenyl ether (BDE-209) is a widely used brominated flame retardant that can easily detach from materials and enter into feed and foodstuffs, posing a serious risk to human and animal health and food safety of animal origin. However, the immunotoxic effects of BDE-209 on the avian spleen and the exact mechanism of the toxicity remain unknown. Therefore, we established an experimental model of BDE-209-exposed chickens and a positive control model of cyclophosphamide-induced immunosuppression in vivo and treated MDCC-MSB-1 cells and chicken splenic primary lymphocytes with BDE-209 in vitro. The results showed that BDE-209 treatment caused morphological and structural abnormalities in the chicken spleens. Mechanistically, indicators related to oxidative stress, endoplasmic reticulum stress (ERS), autophagy, and apoptosis were significantly altered by BDE-209 exposure in both the spleen and lymphocytes, but the use of the N-acetylcysteine or the 4-phenylbutyric acid significantly reversed these changes. In addition, BDE-209 exposure decreased the spleen antimicrobial peptide and immunoglobulin gene expression. In conclusion, the present research revealed that BDE-209 exposure enhanced lymphocyte autophagy and apoptosis in chicken spleen via the ROS-mediated ERS pathway. This signaling cascade regulatory relationship not only opens up a new avenue for studying BDE-209 immunotoxicity but also provides important insights into preventing BDE-209 hazards to animal health.

Sulforaphane protects from kidney damage during the release of unilateral ureteral obstruction (RUUO) by activating nuclear factor erythroid 2-related factor 2 (Nrf2): Role of antioxidant, anti-inflammatory, and antiapoptotic mechanisms

Releasing unilateral ureteral obstruction (RUUO) is the gold standard for decreasing renal damage induced during unilateral ureteral obstruction (UUO); however, the complete recovery after RUUO depends on factors such as the time and severity of obstruction and kidney contralateral compensatory mechanisms. Interestingly, previous studies have shown that kidney damage markers such as oxidative stress, inflammation, and apoptosis are present and even increase after removal obstruction. To date, previous therapeutic strategies have been used to potentiate the recovery of renal function after RUUO; however, the mechanisms involving renal damage reduction are poorly described and sometimes focus on the recovery of renal functionality. Furthermore, using natural antioxidants has not been completely studied in the RUUO model. In this study, we selected sulforaphane (SFN) because it activates the nuclear factor erythroid 2-related factor 2 (Nrf2), a transcription factor that induces an antioxidant response, decreasing oxidative stress and inflammation, preventing apoptosis. Thus, we pre-administrated SFN on the second day after UUO until day five, where we released the obstruction on the three days after UUO. Then, we assessed oxidative stress, inflammation, and apoptosis markers. Interestingly, we found that SFN administration in the RUUO model activated Nrf2, inducing its translocation to the nucleus to activate its target proteins. Thus, the Nrf2 activation upregulated glutathione (GSH) content and the antioxidant enzymes catalase, glutathione peroxidase (GPx), and glutathione reductase (GR), which reduced the oxidative stress markers. Moreover, the improvement of antioxidant response by SFN restored S-glutathionylation in the mitochondrial fraction. Activated Nrf2 also reduced inflammation by lessening the nucleotide-binding domain-like receptor family pyrin domain containing 3 and interleukin 1β (IL-1β) production. Reducing oxidative stress and inflammation prevented apoptosis by avoiding caspase 3 cleavage and increasing B-cell lymphoma 2 (Bcl2) levels. Taken together, the obtained results in our study showed that the upregulation of Nrf2 by SFN decreases oxidative stress, preventing inflammation and apoptosis cell death during the release of UUO.

Zinc attenuates arsenic overdose-induced brain damage via PERK/ATF6 and TLR/MyD88/NF-κB pathways

Exposure to arsenic (As), a widespread non-metallic toxicant in nature, often results in neurotoxicity, although the exact mechanism is unknown. Zinc (Zn) is a powerful nutrient often thought to be beneficial for growth, development and immunity. Whether Zn can rescue brain damage caused by As contamination remains to be demonstrated. Therefore, in this study, a 30-day model of As poisoning (2.83 mg/L) in carp was established and treated with Zn (1 mg/L) to investigate the detoxification mechanism involved. Histological observations showed that As induced the loosening of the molecular layer structure of the cerebellum and the dissolution or even disappearance of nuclei, accompanied by the occurrence of microthrombi in the granular layer, and the addition of Zn attenuated such As-induced damage. Further mechanistic studies indicated that Zn ameliorated As exposure-induced abnormalities in antioxidant capacity (decreased CAT and Cu/Zn-SOD), activation of the Nrf2/keap1 pathway and endoplasmic reticulum stress (ERs), which is a key factor in As-induced brain damage. ERs (high expression of PERK, ATF6, CHOP, eiF2α and GRP78) and inflammation (overexpression of TLR2, TLR4, MyD88, IKK, NF-κB, IL-1β and IL-6 and low expression of IκBα and IL-10). We suggest that Zn can alleviate excessive As-induced brain damage by attenuating As-induced oxidative stress, PERK/ATF6 and TLR/MyD88/NF-κB pathways. The present study fills in the preventive mechanism of As injury in fish and provides the possibility of prevention and control of As pollution-induced brain tissue injury by Zn rescue.

Exogenous Melatonin Alleviates Atrazine-Induced Glucose Metabolism Disorders in Mice Liver via Suppressing Endoplasmic Reticulum Stress

Atrazine (ATZ) is a widely used herbicide that has toxic effects on animals. Melatonin (MLT) is a natural hormone with strong antioxidant properties. However, the effect of MLT on the glucose metabolism disorder caused by ATZ is still unclear. Mice were divided into four groups randomly and given 21 days of gavage: blank control group (Con), 5 mg/kg MLT group (MLT), 170 mg/kg ATZ group (ATZ), and 170 mg/kg ATZ and 5 mg/kg MLT group (ATZ + MLT). The results show that ATZ alters mRNA levels of metabolic enzymes related to glycogen synthesis and glycolysis and increased metabolites (glycogen, lactate, and pyruvate). ATZ causes abnormalities in glucose metabolism in mouse liver, interfering with glycemia regulation ability. MLT can regulate the endoplasmic reticulum to respond to disordered glucose metabolism in mice liver. This study suggested that MLT has the power to alleviate the ATZ-induced glycogen overdeposition and glycolytic deficit.

Modulating SIRT1, Nrf2, and NF-κB signaling pathways by bergenin ameliorates the cadmium-induced nephrotoxicity in rats

In light of the current industrial evolution, exposure to cadmium has become a significant public health concern. Cadmium accumulates in the renal tubular cells and causes nephrotoxicity largely through disruption of the redox homeostasis, induction of inflammation, and suppression of the histone deacetylase SIRT1 expression. The current work aimed at exploring the protective capability of bergenin, a naturally-occurring methyl gallic acid derivative, against the cadmium-evoked nephrotoxicity. Male Wistar rats were treated either with cadmium alone or with cadmium and bergenin for a 7-day experimental period followed by collection of kidney and blood specimens that were subjected to biochemical, molecular, and histological investigations. The results revealed the ability of bergenin to improve the renal functions in the cadmium-intoxicated rats as evidenced by increased glomerular filtration rate, and decreased serum creatinine and blood urea nitrogen. Equally important, bergenin reduced the renal tissue injury and enhanced its redox homeostasis as indicated by decreased protein expression of the kidney injury marker KIM-1, reduced lipid peroxidation, and improved antioxidant potential and histopathological picture of the renal tissues. Mechanistically, bergenin reduced the renal tissue cadmium content, markedly up-regulated protein expression of SIRT1 that regulates inflammation and the redox status of the renal tissues. Additionally, it improved the expression of the major antioxidant transcription factor Nrf2 and its responsive gene products heoxygenase-1 and NAD(P)H quinone dehydrogenase 1 in the cadmium-intoxicated rats. In the same context, bergenin down-regulated the acetylation and the nuclear translocation of the inflammatory transcription factor NF-κB and reduced levels of its responsive gene products TNF-α and IL-1β, as well as the activity of the inflammatory cell infiltration biomarker myeloperoxidase. Collectively, the current study underscores the ameliorating activity of bergenin against the cadmium-evoked nephrotoxicity and highlights modulation of SIRT1, Nrf2, and NF-κB signaling as potential underlining molecular mechanisms.

Co-exposure to molybdenum and cadmium evokes necroptosis and decreases apoptosis in duck myocardium

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.

Effect of atrazine on testicular toxicity involves accommodative disorder of xenobiotic metabolizing enzymes system and testosterone synthesis in European quail (Coturnix coturnix)

Due to the wide use of atrazine (ATR), the concern has increased regarding the negative impact of ATR on reproduction. Nevertheless, the reproductive effects caused by different exposure concentrations and the severity of toxic damage are poorly understood. In organisms, ATR is metabolized and degraded through phase II enzyme systems, and changes in cytochrome P450 (CYP) enzymes may have a regulatory role in the harm of ATR. However, less information is available on the induction of CYPs by ATR in avian organisms, and even less on its effects on the testis. Birds are exposed to ATR mainly through food residues and contaminated water, the purpose of this study was to examine reproductive toxicity by different exposure concentrations and elaborate metabolic disorders caused by ATR in European quail (Coturnix coturnix). In this study, the quail were given ATR at 50 mg/kg, 250 mg/kg and 500 mg/kg by oral gavage for 45 days, and the testicular weight coefficients, histopathology and ultrastructure of testes, primary biochemical functions, sex steroid hormones, critical protein levels in the testosterone synthesis pathway, the expression of genes involved CYPs, gonad axis and nuclear receptors expression were investigated. Altogether, testicular coefficient decreased significantly in the high-dose group (1.22%) compared with the control group (3.03%) after 45 days of ATR exposure, and ATR is a potent CYP disruptor that acts through the NXRs and steroid receptor subfamily (APND, CAR, ERND and ERα) without a dose-dependent manner. Notably, ATR interfered with the homeostasis of hormones by triggering the expression of hormones on the gonad axis (LH and E2). These results suggest that exposure to ATR can cause testicular toxicity involving accommodative disorder of phase II enzyme and testosterone synthesis in European quail.

Nrf2 modulates the benefits of evening exercise in type 2 diabetes

Exercise has well-characterized therapeutic benefits in the management of type 2 diabetes mellitus (T2DM). Most of the beneficial effects of exercise arise from the impact of nuclear factor erythroid 2 related factor-2 (Nrf2) activation of glucose metabolism. Nrf2 is an essential controller of cellular anti-oxidative capacity and circadian rhythms. The circadian rhythm of Nrf2 is influenced by circadian genes on its expression, where the timing of exercise effects the activation of Nrf2 and the rhythmicity of Nrf2 and signaling, such that the timing of exercise has differential physiological effects. Exercise in the evening has beneficial effects on diabetes management, such as lowering of blood glucose and weight. The mechanisms responsible for these effects have not yet been associated with the influence of exercise on the circadian rhythm of Nrf2 activity. A better understanding of exercise-induced Nrf2 activation on Nrf2 rhythm and signaling can improve our appreciation of the distinct effects of morning and evening exercise. This review hypothesizes that activation of Nrf2 by exercise in the morning, when Nrf2 level is already at high levels, leads to hyperactivation and decrease in Nrf2 signaling, while activation of Nrf2 in the evening, when Nrf2 levels are at nadir levels, improves Nrf2 signaling and lowers blood glucose levels and increases fatty acid oxidation. Exploring the effects of Nrf2 activators on rhythmic signaling could also provide valuable insights into the optimal timing of their application, while also holding promise for timed treatment of type 2 diabetes.

Zinc-Mediated Endoplasmic Reticulum Stress and Metallothionein Alleviate Arsenic-Induced Cardiotoxicity in Cyprinus Carpio

Arsenic (As) is a natural component of the Earth's crust, and its inorganic form is highly toxic. The problem of As pollution in water is extremely urgent, and its impact on aquatic organisms should be widely considered. Here, 120 common carp were selected as the test subjects and were exposed to environmentally relevant concentrations of As (2.83 mg L- 1) for 30 days. Histomorphological observations showed the adverse effects of As on the heart: irregular arrangement of myocardial fibers, rupture of muscle fiber bundles, inflammatory infiltration, and hemorrhages. Mechanistically, abnormal expression of factors related to As-induced inflammation (TLR4/MYD88/NF-κB pathway), endoplasmic reticulum stress (CHOP, GRP78, ATF6, PERK, IRE1) and oxidative stress (SOD, CAT, Nrf2, HO-1) was observed. Then, we tried to find a protective agent against As-induced myocardial injury. As one of the important metal elements for maintaining cell growth and immunity, zinc (Zn, 1 mg L- 1) significantly alleviated the pathological abnormalities induced by As, and the changes in physiological and biochemical indices in response to As exposure were significantly alleviated by Zn administration, which was accompanied by the restoration of metallothionein (ZIP8, Znt1, Znt5, Znt7) and heat shock protein (HSP60, HSP70, HSP90) expression. These results suggest for the possibilty of developing Zn as a candidate therapeutic agent for As induced aquatic toxicology.

The intricate role of annexin A2 in kidney: a comprehensive review

Annexin A2 (Anxa2) is a calcium (Ca2+)-regulated phospholipid binding protein composed of a variable N-terminus and a conserved core domain. This protein has been widely found in many tissues and fluids, including tubule cells, glomerular epithelial cells, renal vessels, and urine. In acute kidney injury, the expression level of this protein is markedly elevated in response to acute stress. Moreover, Anxa2 is a novel biomarker and potential therapeutic target with prognostic value in chronic kidney disease. In addition, Anxa2 is associated not only with clear-cell renal cell carcinoma differentiation but also the formation of calcium-related nephrolithiasis. In this review, we discuss the characteristics and functions of Anxa2 and focus on recent reports on the role of Anxa2 in the kidney, which may be useful for future research.

Baicalein inhibits apoptosis and autophagy induced by chlorpyrifos exposure to kidney of Cyprinus carpio through activation of PI3K/AKT pathway

Chlorpyrifos (CPF), a widely used organophosphate pesticide that has caused large-scale contamination globally, has become a major concern. Baicalein (BAI), as a flavonoid extract, shows anti-inflammatory as well as antioxidant activities. The kidneys of fish serve to excrete toxins and are major target organs for environmental contaminants. However, it is not obvious whether BAI can counteract the damage caused by CPF exposure to fish kidneys. Therefore, we conducted a 30-day simulation of CPF poisoning and/or BAI treatment by adding 23.2 μg/L CPF to water and/or 0.15 g/kg BAI to feed. In the transmission electron microscopy results, we observed obvious phenomenon of autophagy and apoptosis in the CPF group, and the TUNEL staining and immunofluorescence of LC3B and p62 double-staining results confirmed that CPF induced autophagy and apoptosis in the kidney of common carp. Furthermore, CPF induced the increase of ROS level and inhibition of PI3K and Nrf2 pathways, which in turn triggered oxidative stress, autophagy and apoptosis in carp kidney according to western blot, RT-qPCR and kit assays. However, addition of BAI significantly alleviated oxidative stress, autophagy and apoptosis due to binding to PI3K protein. Additionally, through phylogenetic tree and structural domain analyses, we also found that the binding sites of BAI and PI3K are conserved in a variety of representative species. These results suggest that BAI antagonizes CPF-caused renal impairments in carp involving the PI3K/AKT pathway and the Nrf2 pathway. Our findings provide new insights into the nephrotoxicity effects of CPF and the potential use of BAI as a detoxification agent for CPF intoxication.

Unraveling the protective role of Nrf2 in molluscs: Insights into mitochondrial and apoptosis pathways in the defense against Bap-induced oxidative stress

Benzopyrene (Bap) is a major constituent of petroleum pollutants commonly found in aquatic environments, and its mutagenic and carcinogenic properties have adverse effects on aquatic organisms' development, growth, and reproduction. The antioxidant defense system element, NF-E2-related factor 2 (Nrf2), has been linked to the oxidative stress response in marine invertebrates exposed to toxic substances. In a previous study, a novel Nrf2 homologue, McNrf2, was identified in mussel Mytilus coruscus, a significant model marine molluscs in ecotoxicology studies. McNrf2 showed the potential to trigger an antioxidant defense against oxidative stress induced by Bap. Here, we employed an Nrf2 overexpression and inhibition model using SFN and ML385 as Nrf2 inducer and inhibitor, respectively. Next, immunofluorescence technique was used to evaluate the nuclear activation of Nrf2 induced by Bap-mediated oxidative stress. Transmission electron microscopy revealed that overexpression of Nrf2 could maintain the quantity and structural integrity of mitochondria, while flow cytometry analysis showed that Nrf2 could alleviate Bap-induced cellular apoptosis. These findings suggest that Nrf2 can protect molluscs from Bap-induced oxidative stress through the mitochondria and apoptosis pathways, providing a novel perspective on Nrf2's antioxidant function.

Fluoride-induced osteoporosis via interfering with the RANKL/RANK/OPG pathway in ovariectomized rats: Oophorectomy shifted skeletal fluorosis from osteosclerosis to osteoporosis

Osteosclerosis and osteoporosis are the two main clinical manifestations of skeletal fluorosis. However, the reasons for the different clinical manifestations are unclear. In this study, we established the fluoride (F) -exposed ovariectomized (OVX) and non-OVX rat models to assess the potential role of ovarian function loss in osteosclerosis and osteoporosis. Micro-CT scanning showed that excessive F significantly induced a high bone mass in non-OVX rats. In contrast, a low bone mass manifestation was presented in OVX F-exposed rats. Also, a prominent feature of increasing trabecular connectivity, collagen area, growth plate thickness, and reduced trabecular space was found by histopathological morphology in non-OVX F-exposed rats; an opposite result was observed in OVX F-exposed. These alterations indicated ovariectomy was a vital factor leading to osteosclerosis or osteoporosis in skeletal fluorosis. Furthermore, levels of bone alkaline phosphatase (BALP) and tartrate-resistant acid phosphatase (TRAP) increased, combined with the increasing osteoclasts number, showing a sign of high bone turnover in both OVX and non-OVX F-exposed rats. Mechanistically, oophorectomy considerably activated the RANKL/RANK/OPG signaling pathway. Meanwhile, it was discovered that upregulated NF-κB positively facilitated the accumulation of nuclear factor of activated T-cells 1 (NFATC1), significantly promoting osteoclast differentiation. To sum up, this study greatly enriched the causes of clinical skeletal fluorosis and provided a new perspective for studying the pathogenesis of skeletal fluorosis.

Melatonin alleviates renal injury in diabetic rats by regulating autophagy

Melatonin (MLT) is a biologically active indoleamine involved in regulating various biological rhythms, which is deficient in individuals with Type 2 diabetes. The present study examined the effects of MLT on diabetic neuropathy (DN). Diabetic rats received MLT treatment for 12 weeks, after which changes in kidney histology, oxidative damage, mitochondrial morphology and autophagy were measured. The glucose tolerance‑ and isoflurane tolerance‑area under the curve (AUC) values and the relative renal weight index (RI) in the diabetes mellitus (DM) group of rats were significantly higher compared with those in the control group. A significant increase in malondialdehyde (MDA) content, and decreases in the activity of superoxide dismutase (SOD), catalase (CAT), glutathione peroxidase (GSH‑Px) and GSH were demonstrated in the kidneys of DM rats compared with those in the control rats. Histological staining of DM rat kidney tissue with hematoxylin and eosin, Masson's trichome and Periodic acid‑Schiff demonstrated glomerular and tubule lesions, and an increase in collagen compared with control rats. Protein expression levels of LC3II, P62, collagen IV (COL‑IV) and α‑SMA were increased in DM rats and HG‑induced NRK‑52E cells compared with those in the control groups. Phosphorylation of AMPK was reduced, whereas phosphorylation of PI3K, Akt and mTOR were increased in vivo and in vitro. Notably, MLT treatment significantly reduced glucose tolerance‑AUC and RI, decreased MDA content, and increased SOD, CAT, GSH‑Px and GSH activity. Glomerular and tubule lesions improved, collagen was decreased and mitochondrial damage was alleviated by MLT treatment. MLT treatment also decreased the protein expression levels of LC3II, P62 and COL‑IV, whereas the phosphorylation of AMPK was significantly increased, which inhibited the phosphorylation of PI3K, AKT and mTOR in vivo and in vitro. These results demonstrated that MLT protects against DN and NRK‑52E cell injury through inhibiting oxidative damage and regulating autophagy via the PI3K/AKT/mTOR signaling pathway.

Geniposide stimulates autophagy by activating the GLP-1R/AMPK/mTOR signaling in osteoarthritis chondrocytes

Osteoarthritis (OA) is a chronic joint disease characterized by cartilage degeneration. Autophagy is associated with chondrocyte homeostasis and exhibits a role in protecting against OA pathogenesis. Geniposide (GEN), an iridoid glycoside extracted from Eucommia ulmoides Oliv, acts as an activator of GLP-1R, which can stimulate autophagy. The AMPK/mTOR signaling pathway participates in the mediation of autophagy, and GLP-1R may act as an upstream factor of AMPK. However, whether GEN mediates the autophagic responses by activating the GLP-1R/AMPK/mTOR signaling pathway in OA chondrocytes is still unclear. In the current study, attenuated autophagy in MIA-induced rat OA models was observed, as shown by up-regulated expression of p62 and down-regulated expression of Beclin-1 and LC3-II/I. GEN stimulated autophagy and protected OA cartilage by up-regulating GLP-1R expression. In addition, GEN could enhance AMPK phosphorylation and down-regulate mTOR expression in IL-1β-treated C28/I2 cells. Inhibition of AMPK or activation of mTOR could reverse the stimulatory effects of GEN on autophagy. Furthermore, a GLP-1R inhibitor Exendin 9-39 could eliminate the chondroprotective effects of GEN by suppressing the AMPK/mTOR signaling pathway. Conclusively, Geniposide exhibits protective effects against osteoarthritis development by stimulating autophagy via activating the GLP-1R/AMPK/mTOR signaling pathway.

Antagonistic effect of selenium on programmed necrosis of testicular Leydig cells caused by cadmium through endoplasmic reticulum stress in chicken

Cadmium (Cd) is a widely distributed environmental contaminant that is highly toxic to animals and humans. However, detailed reports on Cd-induced programmed necrosis have not been seen in chicken testicular Leydig cells. Selenium (Se) is a trace element in the human body that has cytoprotective effects in a variety of pathological damages caused by heavy metals. This study investigated the potential mechanisms of Cd-induced programmed cell necrosis and the antagonistic effect of Se on Cd toxicity. Chicken testis Leydig cells were divided into six groups, namely, control, Se (5 µmol/L Na2SeO3), Cd (20 µmol/L CdCl2), Se + Cd (5 µmol/L Na2SeO3 and 20 µmol/L CdCl2), 4-phenylbutyric acid (4-PBA) + Cd (10 mmol/L 4-phenylbutyric acid and 20 µmol/L CdCl2), and Necrostatin-1 (Nec-1) + Cd (60 µmol/L Necrostatin-1 and 20 µmol/L CdCl2). The results showed that Cd exposure decreased the activity of CAT, GSH-Px, and SOD and the concentration of GSH, and increased the concentration of MDA and the content of ROS. Relative mRNA and protein expression of GRP78, PERK, ATF6, IRE1, CHOP, and JNK increased in the Cd group, and mRNA and protein expression of TNF-α, TNFR1, RIP1, RIP3, MLKL, and PARP1 significantly increased in the Cd group, while Caspase-8 mRNA and protein expression significantly decreased. The abnormal expression of endoplasmic reticulum stress-related proteins was significantly reduced by 4-PBA pretreatment; the increased expression of TNF-α, TNFR1, RIP1, RIP3, MLKL, and PARP1 caused by Cd toxicity was alleviated; and the expression of caspase-8 was upregulated. Conversely, the increased mRNA and protein expression of endoplasmic reticulum stress marker genes (GRP78, ATF6, PERK, IRE1, CHOP, JNK) caused by Cd was not affected after pretreatment with Nec-1. We also found that these Cd-induced changes were significantly attenuated in the Se + Cd group. We clarified that Cd can cause programmed necrosis of chicken testicular Leydig cells through endoplasmic reticulum stress, and Se can antagonize Cd-induced programmed necrosis of chicken testicular Leydig cells.

Selenium alleviates lead-induced CIK cells pyroptosis and inflammation through IRAK1/TAK1/IKK pathway

The toxic heavy metal lead is widely found in rivers and soils as an environmental pollutant, posing a threat to the health of aquatic organisms. Selenium is an essential trace element and a powerful antioxidant that has been shown to have anti-inflammatory and antioxidant properties as well as alleviating heavy metal poisoning. Many studies have shown that lead poisoning produces inflammatory responses and damage to the kidneys of a wide range of animals, but the effects on cellular pyroptosis and immune function and selenium antagonism in CIK cells are not clear. In this study, 500 μM Pb and 20 nM Se were applied to grass carp kidney cells, and the results showed that Pb exposure to CIK cells resulted in oxidative stress, activation of the IRAK1/TAK1/IKK pathway, up-regulation of the expression of cellular pyroptosis markers GSDMD and NLRP3, and cellular pyroptosis of CIK cells, as well as up-regulation of IL-1β and IL-18, and the generation of cellular inflammatory response. In contrast, Se treatment significantly reduced the ROS level, the expression of cellular pyroptosis markers GSDMD, NLRP3 and inflammatory element IL-1β and IL-18. Taken together, Se alleviated cellular pyroptosis and immune dysfunction caused by Pb exposure through oxidative stress and activation of the IRAK1/TAK1/IKK pathway. This study complements the harmful effects of the heavy metal Pb on fish and the real-life application of selenium in the healthy culture of fish as a reference will be provided.

Dose-effect of polystyrene microplastics on digestive toxicity in chickens (Gallus gallus): Multi-omics reveals critical role of gut-liver axis

INTRODUCTION

Microplastic pollution seriously threatens the health and safety of humans and wildlife. Avian is one of the main species endangered by microplastics. However, the damage mechanism of microplastics to the digestive system of avian is not clear.

OBJECTIVES

The gut-liver axis is a bidirectional channel that regulates the exchange of information between the gut and the liver and is also a key target for tissue damage caused by pollutants. This study aimed to elucidate the digestive toxicity of microplastics in avian and the key role of the gut-liver axis in it.

METHODS

We constructed an exposure model for microplastics in environmental concentrations and toxicological concentrations in chickens and reveal the digestive toxicity of polystyrene microplastics (PS-MPs) in avian by 16S rRNA, transcriptomics and metabolomics.

RESULTS

PS-MPs changed the death mode from apoptosis to necrosis and pyroptosis by upregulating Caspase 8, disrupting the intestinal vascular barrier, disturbing the intestinal flora and promoting the accumulation of lipopolysaccharide. Harmful flora and metabolites were translocated to the liver through the liver-gut axis, eliciting hepatic immune responses and promoting hepatic lipid metabolism disorders and apoptosis. Liver injury involves multiple molecular effects of mitochondrial dynamics disturbance, oxidative stress, endoplasmic reticulum stress, and cell cycle disturbance. Furthermore, metabolomics suggested that caffeine and melanin metabolites may be potential natural resistance substances for microplastics.

CONCLUSION

Taken together, our data demonstrate the digestive damage of PS-MPs in avian, revealing a critical role of the liver-gut axis in it. This will provide a reference for protecting the safety of avian populations.

New insights into Microalgal astaxanthin's effect on Lambda-cyhalothrin-induced lymphocytes immunotoxicity in Cyprinus carpio: Involving miRNA-194-5p-FoxO1-mediated-mitophagy and pyroptosis

Lambda-cyhalothrin (LC), a pyrethroid insecticide widely used in agriculture, causes immunotoxicity to aquatic organisms in the aquatic environment. Microalgal astaxanthin (MA) is a natural carotenoid that enhances viability of a variety of fish. To investigate the immunotoxicity of LC and the improvement effect of MA in lymphocytes (Cyprinus carpio), lymphocytes were treated with LC (80 M) and/or MA (50 M) for 24 h. Firstly, CCK8 combined with PI staining results showed that MA significantly attenuated the LC-induced lymphocyte death rate. Secondly, LC exposure resulted in excessively damaged mitochondrial and mtROS, diminished mitochondrial membrane potential and ATP content, which could be improved by MA. Thirdly, MA upregulated the levels of mitophagy-related regulatory factors (Beclin1, LC3, ATG5, Tom20 and Lamp2) induced by LC. Importantly, MA decreased the levels of pyroptosis-related genes treated with LC, including NLRP3, Cas-4, GSDMD and active Cas-1. Further study indicated that LC treatment caused excessive miRNA-194-5p and reduced levels of FoxO1, PINK1 and Parkin, which was inhibited by MA treatment. Overall, we concluded that MA could enhance damaged mitochondrial elimination by promoting the miRNA-194-5p-FoxO1-PINK1/Parkin-mitophagy in lymphocytes, which reduced mtROS accumulation and alleviated pyroptosis. It offers insights into the importance of MA application in aquaculture as well as the defense of farmed fish against agrobiological hazards in fish under LC.

Protective effects of sinapic acid against lead acetate-induced nephrotoxicity: a multi-biomarker approach

Lead acetate (PbAc) is one of the top five most dangerous toxic heavy metals, particularly leading to kidney damage and posing serious health risks in both humans and animals. Sinapic acid (SNP) is a naturally occurring flavonoid found in fruits and vegetables that stands out with its antioxidant, anti-inflammatory, and anticancer properties. This is the first study to investigate the effects of SNP on oxidative stress, inflammation, apoptosis, autophagy and endoplasmic reticulum (ER) stress in PbAc-induced nephrotoxicity in rats by biochemical, molecular and histological methods. 35 Spraque dawley rats were randomly divided into five groups of 7 rats each: control, PbAc, SNP (10mg/kg), PbAc + SNP 5, PbAC + SNP 10. PbAc at a dose of 30 mg/kg body weight was administered via oral gavage alone or in combination with SNP (5 and 10 mg/kg body weight) via oral gavage for seven days. While PbAc impaired renal function by increasing serum urea and creatinine levels, SNP decreased these levels and contributed to the improvement in renal function. The administration of SNP reduced oxidative stress by increasing PbAc-induced decreased antioxidant enzyme (SOD, CAT, and GPx) activities and GSH levels, decreasing MDA levels, a marker of increased lipid peroxidation. SNP administration reduced NF-κB, TNF-α, IL-1β, NLRP3, and RAGE mRNA transcription levels, NF-κB, and TNF-α protein levels that are among the PbAc-induced increased inflammation parameters. Decreases in antiapoptotic Bcl-2 and increases in apoptotic Bax, APAF-1, and Caspase-3 due to PbAc exposure, SNP reversed the situation. SNP reduced ER stress caused by PbAc by increasing PERK, IRE1, ATF-6, CHOP, and GRP-78 levels and made it tend to regress. SNP reduced autophagy damage by decreasing the Beclin-1 protein level increased by PbAc. The findings of the present study suggested that SNP attenuates PbAc-induced nephrotoxicity.

Swainsonine inhibits autophagic degradation and causes cytotoxicity by reducing CTSD O-GlcNAcylation

Swainsonine (SW) is the primary toxin in locoweed, a poisonous plant. SW can cause animal poisoning, affect the quality and safety of meat products and threaten human health, but the mechanism of its toxicity is little defined. Here, we identified 159 differentially expressed proteins, many of which are involved in autophagy and glycosylation modification processes, using proteomics sequencing analysis. O-linked-N-acetylglucosamylation (O-GlcNAcylation) is a glycosylation modification widely involved in various biological processes. Our results show that SW toxicity is related to O-GlcNAcylation. In addition, increased O-GlcNAcylation with the O-GlcNAcase (OGA) inhibitor TMG promoted autophagy, while decreased O-GlcNAcylation with the O-GlcNAc transferase (OGT) inhibitor OSMI inhibited autophagy. Further analysis by Immunoprecipitation (IP) showed that SW could change the O-GlcNAcylation of Cathepsin D (CTSD), reducing the expression of mature CTSD (m-CTSD). In summary, these findings suggest that SW inhibits the O-GlcNAcylation of CTSD, affecting its maturation and leading to the impairment of lysosome function. Consequently, it inhibits autophagy degradation, and causes cytotoxicity, providing a new theoretical basis for SW toxicological mechanism.

Melatonin alleviates cadmium-induced nonalcoholic fatty liver disease in ducks by alleviating autophagic flow arrest via PPAR-α and reducing oxidative stress

Cadmium (Cd) is an important environmental pollutant that causes liver damage and induces nonalcoholic fatty liver disease (NAFLD). NAFLD is a fat accumulation disease and has significant effects on the body. Melatonin (Mel) is an endogenous protective molecule with antioxidant, anti-inflammatory, antiobesity, and antiaging effects. However, whether Mel can alleviate Cd-induced NAFLD and its mechanism remains unclear. First, in vivo, we found that Mel maintained mitochondrial structure and function, inhibited oxidative stress, and reduced Cd-induced liver injury. In addition, Mel alleviated lipid accumulation in the liver induced by Cd. In this process, Mel inhibits fatty acid production and promotes fatty acid oxidation. Interestingly, Mel regulated PPAR-α expression and alleviated Cd-induced autophagy blockade. In vitro model, the oil Red O staining, and WB results showed that Mel alleviated Cd-induced lipid accumulation. In addition, RAPA was used to activate autophagy to alleviate Cd-induced lipid accumulation, and TG was used to block autophagy flux to aggravate Cd-induced autophagy accumulation. After knocking down PPAR-α, the autophagosome fusion with lysosomes, and autophagic flux was inhibited and increased Cd-induced lipid accumulation. Mel alleviates mitochondrial damage and oxidative stress, and attenuates Cd-induced NAFLD by restoring the expression of PPAR-α and restoring autophagy flux.

Metal mixture exposure and the risk for immunoglobulin A nephropathy: Evidence from weighted quantile sum regression

Immunoglobulin A nephropathy (IgAN) is the most common type of glomerulonephritis in adults worldwide. Environmental metal exposure has been reported to be involved in the pathogenic mechanisms of kidney diseases, yet no further epidemiological study has been conducted to assess the effects of metal mixture exposure on IgAN risk. In this study, we conducted a matched case‒control design with three controls for each patient to investigate the association between metal mixture exposure and IgAN risk. A total of 160 IgAN patients and 480 healthy controls were matched for age and sex. Plasma levels of arsenic, lead, chromium, manganese, cobalt, copper, zinc, and vanadium were measured using inductively coupled plasma mass spectrometry. We used a conditional logistic regression model to assess the association between individual metals and IgAN risk, and a weighted quantile sum (WQS) regression model to analyze the effects of metal mixtures on IgAN risk. Restricted cubic splines were used to evaluate overall associations between plasma metal concentrations and estimated glomerular filtration rate (eGFR) levels. We observed that except for Cu, all the metals analyzed were nonlinearly associated with decreased eGFR, and higher concentrations of arsenic and lead were associated with elevated IgAN risk in both single-metal [3.29 (1.94, 5.57), 6.10 (3.39, 11.0), respectively] and multiple-metal [3.04 (1.66, 5.57), 4.70 (2.47, 8.97), respectively] models. Elevated manganese [1.76 (1.09, 2.83)] levels were associated with increased IgAN risk in the single-metal model. Copper was inversely related to IgAN risk in both single-metal [0.392 (0.238, 0.645)] and multiple-metal [0.357 (0.200, 0.638)] models. The WQS indices in both positive [2.04 (1.68, 2.47)] and negative [0.717 (0.603, 0.852)] directions were associated with IgAN risk. Lead, arsenic, and vanadium contributed significant weights (0.594, 0.195, and 0.191, respectively) in the positive direction; copper, cobalt, and chromium carried significant weights (0.538, 0.253, and 0.209, respectively). In conclusion, metal exposure was related to IgAN risk. Lead, arsenic, and copper were all significantly weighted factors of IgAN development, which may require further investigation.

Micro-algal astaxanthin improves lambda-cyhalothrin-induced necroptosis and inflammatory responses via the ROS-mediated NF-κB signaling in lymphocytes of carp (Cyprinus carpio L.)

Lambda-cyhalothrin (LCY) is a widely used toxic pesticide that causes harmful effects on the immune organs of fish and aquatic species. Micro-algal astaxanthin (MAA), a heme pigment found in haematococcus pluvialis, has been shown to benefit antioxidants and immunity in aquaculture. To investigate how MAA protects carp lymphocytes from LCY-induced immunotoxicity, a model of fish lymphocytes treated with LCY and/or MAA was established. Lymphocytes from carp (Cyprinus carpio L.) were given LCY (80 μM) and/or MAA (50 μM) as a treatment for a period of 24 h. Firstly, LCY exposure resulted in excessive ROS and malondialdehyde production and reduces antioxidant enzymes (SOD and CAT), indicating a reduced capacity of the antioxidant system. Secondly, the results of flow cytometry and AO/EB labeling proved that lymphocytes treated with LCY have a larger ratio of necroptosis. In addition, LCY upregulated the levels of necroptosis-related regulatory factors (RIP1, RIP3 and MLKL) via the ROS-mediated NF-κB signaling pathway in lymphocytes. Thirdly, LCY treatment caused increased secretion of inflammatory genes (IL-6, INF-γ, IL-4, IL-1β and TNF-α), leading to immune dysfunction in lymphocytes. Surprisingly, LCY-induced immunotoxicity was inhibited by MAA treatment, indicating that it effectively attenuated the LCY-induced changes described above. Overall, we concluded that MAA treatment could ameliorate LCY-induced necroptosis and immune dysfunction by inhibiting the ROS-mediated NF-κB signaling in lymphocytes. It provides insights into the protection of farmed fish from agrobiological threats in fish under LCY and the value of MAA applications in aquaculture.

Autophagy protects against Cd-induced cell damage in primary chicken hepatocytes via mitigation of oxidative stress and endoplasmic reticulum stress

Cadmium (Cd) is widespread globally in the environment as a toxic metal. Although it is well known to induce hepatotoxicity in the cells, defense mechanisms against the detrimental effects of Cd are still unknown. We examined the role of autophagy (a cellular defense mechanism) on Cd-induced cytotoxicity in bird hepatocytes. Primary chicken hepatocytes were cultured with different concentrations (0, 1, 2.5, 5, and 10 μM) of cadmium chloride (CdCl₂) for 12 h. We assessed the effects of CdCl₂ on the cell viability, antioxidant status, reactive oxygen species (ROS) generation, autophagy response and endoplasmic reticulum (ER) stress. Further, it is also evaluated that insight into underling molecular mechanisms involved in the study. In this study, CdCl₂-induce hepatotoxicity was caused by drastically increased ROS generation as well as a reduction level of antioxidant enzymes. It was also demonstrated that marked activation of ER stress markers (GRP78, IRE1, PERK, ATF4, ATF6 and XBP-1 s) was observed. Simultaneously, increased activation of autophagy in low-dose CdCl₂ (1 μM) exposed group was observed, but high-dose CdCl₂ (10 μM) inhibited autophagy and significantly promoted apoptosis, as indicated by the expression of the autophagy related genes for P62, Beclin-1, ATG3, ATG5, ATG9, and the detection of autophagic vacuoles. Pretreatment with autophagy agonist Rapamycin (RAP) has successfully reduced ROS production, attenuated ER stress and enhanced hepatocytes viability, while the autophagy inhibitor 3-Methyladenine (3-MA) had the opposite effect. Hence, these findings stipulate that Cd could inhibit viability of hepatocytes in a dose-dependent manner. Autophagy relieves hepatotoxicity of Cd via reducing ROS generation and regulating ER stress. We identified autophagy as a novel protective mechanism involved in Cd-mediated chicken hepatotoxicity.

Polystyrene-microplastics and DEHP co-exposure induced DNA damage, cell cycle arrest and necroptosis of ovarian granulosa cells in mice by promoting ROS production

The joint pollution of microplastics (MPs) and di-(2-ethylhexyl) phthalic acid (DEHP) often occurs, and consequently poses a serious threat to human and animal health, which has attracted widespread attention. However, the damage to the female mammalian ovary caused by the single exposure and co-exposure of MPs and DEHP and its specific mechanisms are not clear. Here, we established mouse models of single and co-exposures to polystyrene-microplastics (PS-MPs) and DEHP. The results showed that exposed to 100 mg/L PS-MPs and 200 mg/kg DEHP for 35 days destroyed the ovarian granulosa cell layer of mice, leading to follicular fragmentation and atresia. We cultured ovary granulosa cells in vitro to perform further mechanism studies and found that PS-MPs and DEHP had synergistic effects. Both of them promoted the excessive production of ROS and induced oxidative stress by triggering the CNR1/CRBN/YY1/CYP2E1 signaling axis, which in turn caused DNA oxidative damage. Additionally, we provided compelling evidence that oxidative stress mediated-hippo signaling pathway played a critical role in PS-MPs and DEHP caused ovary damage, resulting in ovarian granulosa cell cycle arrest and necroptosis. Using oxidative stress inhibitor AM251 or DAS could reverse these changes markedly and alleviate the reproductive toxicity caused by PS-MPs and DEHP, effectively. Overall, these results demonstrated that co-exposure of PS-MPs and DEHP adversely affected the integrity of ovary granulosa cell layer, resulting in DNA oxidative damage, cell cycle arrest and increased necroptosis of mouse ovarian granulosa cells by inducing oxidative stress. Our study shed new light on the co-exposure toxicity of PS-MPs and DEHP, provided novel insights for the reproductive toxicity of PS-MPs combined exposure with DEHP in female animals from a new free radical generation pathway perspective.

Selenium alleviates cadmium-induced oxidative stress, endoplasmic reticulum stress and programmed necrosis in chicken testes

Cadmium (Cd) is a common heavy metal pollutant, and one of the important target organs of its toxicity is the testis. Selenium (Se) has the ability to antagonize the toxicity of Cd. However, the mechanism of the alleviating effects of Se on Cd in chicken testis injury through oxidative stress, endoplasmic reticulum stress (ERS), and programmed necrosis remained unclear. To explore this, 80 7-day-old chickens were divided into the Control group, the Se group (1.00 mg/kg Se), the Cd group (150.00 mg/kg Cd), and the CdSe group. On the 30th and 60th days, serum and chicken testis tissue samples were collected for testing. The results showed that Cd exposure resulted in swelling and deformation of seminiferous tubules, and thinning of the seminiferous epithelium. The ROS and MDA increased, and the SOD, CAT, GSH, GSH-Px decreased. The expression of GRP78, PERK, IRE1, ATF6, CHOP, and JNK in the Cd group increased. The expression of TNF-α, TNFR1, RIP1, RIP3, MLKL, and PARP1 increased, while the expression of Caspase-8 decreased. Histopathological changes, oxidative stress, ERS, and programmed necrosis were improved after CdSe treatment. In conclusion, Se antagonized the toxicity of Cd, and Se could alleviate Cd-induced oxidative stress, ERS, and programmed necrosis in chicken testis.

Roles of selenoprotein K in oxidative stress and endoplasmic reticulum stress under selenium deficiency in chicken liver

Selenoprotein K (SELENOK) is a major part of selenoprotein family. Selenoproteins have been proven playing vital roles in a variety of physiological processes. However, as a necessary supplement to the body of trace elements, how SELENOK regulates necroptosis in chicken liver has none clear claim. The purpose of this study was to cover the mechanism of SELENOK act in necroptosis of chicken liver. By feeding Se-deficiency diet for 1-day-old hyline chickens, we successfully built SELENOK-deficiency and discussed the regulation SELENOK have done. The test of liver function showed there has dysfunction appeared in the -Se groups. Results of TEM showed necroptosis occurred in the 35-Se group. After that western blot and qRT-PCR results prompted us SELENOK-deficiency caused large accumulation of ROS, enhanced endoplasmic reticulum stress, abnormally elevated HSPs family expression, and activated RIPK1-RIPK3 complex. In order to show the regulation of SELENOK in chicken liver, we artificially knocked off SELENOK gene in LMH cells. Through AO/EB staining we also found necroptosis in the siRNA-Se group. Furthermore, the results in LMH cells were coincided with those in chicken (Gallus gallus) liver. Our experiment clarified the molecular mechanism of SELENOK in the regulation and liver necroptosis, and provided reference for the healthy feeding mode of broilers.

Pathogenic mechanism of Eimeria tenella autophagy activation of chicken embryo cecal epithelial cells induced by Eimeria tenella

Eimeria tenella mainly invades and develops into cecal epithelial cells of chickens, resulting in cecal epithelial cell damage. Infectious intracellular pathogens possibly act by influencing the autophagy process after invading cells. The interaction between E. tenella and the autophagy of host cells was explored by infecting E. tenella with chick embryo cecal epithelial cells. Transmission electron microscopy, laser confocal microscopy, and Western blot analysis were used to demonstrate that E. tenella infection could induce autophagy in host cells. Results showed that infection with E. tenella induced the formation of autophagosomes in cells. The expression of ATG 5, Beclin-1, and LC3B-II proteins were significantly (P < 0.01) increased after E. tenella infected host cells. Expression of p62 protein levels were significantly (P < 0.01) decreased in host cells infected with E. tenella. Chloroquine (CQ) significantly (P < 0.01) increased the expression levels of LC3B-II and P62 in E. tenella-infected host cells. Rapamycin (RAPA) induced autophagy in host cells, thus reducing the intracellular infection of E. tenella. By contrast, the infection rate of E. tenella increased in cells treated with 3-Methyladenine (3-MA). Hence, E. tenella sporozoite infection could induce autophagy activation in chick embryo cecal epithelial cells, and enhanced autophagy could reduce the infection rate of E. tenella.

Polystyrene microplastics induce autophagy and apoptosis in birds lungs via PTEN/PI3K/AKT/mTOR

Microplastics (MPs) seriously pollute and potentially threaten human health. Birds are sentinels of environmental pollutants, which respond quickly to contamination events and reveal current environmental exposure. Therefore, birds are good bioindicators for monitoring environmental pollutants. However, the mechanism of lung injury in birds and the role of the PTEN/PI3K/AKT axis are unknown. In this study, broilers treated with different polystyrene microplastics (PS-MPs) (0, 1, 10, and 100 mg/L) were exposed to drinking water for 6 weeks to analyze the effect of PS-MPs on lung injury of broilers. The results showed that with the increase of PS-MPs concentration, malonaldehyde (MDA) content increased, and catalase (CAT) and glutathione (GSH) activity decreased, further leading to oxidative stress. PS-MPs caused the PI3K/Akt/mTOR pathway to be inhibited by phosphorylation, and autophagy accelerated formation (LC3) and degradation (p62), causing autophagy. In PS-MPs exposed lung tissues, the expression of Bax/Bcl-2 and Caspase family increased, and MAPK signaling pathways (p38, ERK, and JNK) showed an increase in phosphorylation level, thus leading to cell apoptosis. Our research showed that PS-MPs could activate the antioxidant system. The antioxidant system unbalance-regulated Caspase family, and PTEN/PI3K/AKT pathways initiated apoptosis and autophagy, which in turn led to lung tissue damage in chickens. These results are of great significance to the toxicological study of PS-MPs and the protection of the ecosystem.

HIF-1α-mediated autophagy and canonical Wnt/β-catenin signalling activation are involved in fluoride-induced osteosclerosis in rats

Fluoride (F) exposure can cause osteosclerosis, which is characterised by a high bone mass, but its mechanism is not fully illustrated. Here, we aimed to evaluate the effects of excessive F exposure on the bone lesion by treating female Sprague-Dawley rats with different concentrations of sodium fluoride (NaF) (0, 55, 110 and 221 mg/L) for 90 days and the corresponding concentrations of fluorine ion (0, 25, 50 and 100 mg/L, respectively). Histopathological results showed that excessive F exposure caused the enlargement of trabeculae and their integration into one large piece, growth plate thickening, articular cartilage impairment and bone collagen abnormality. Meanwhile, F promoted calcium deposition and bone mineralisation, and induced abnormal osteogenesis increased. The results of micro-computed tomography also confirmed that excessive F destroyed the bone microstructure and induced a high-bone-mass phenotype, consistent with the results of pathomorphology. Mechanistically, excessive amounts of F led to angiogenesis inhibition and HIF-1α signalling enhancement. Subsequently, F induced autophagy and canonical Wnt/β-catenin signalling pathway activation. Collectively, these results manifested that F enhanced the hypoxia inducible factor-1α signalling, which in turn triggered autophagy and canonical Wnt/β-catenin signalling activation, ultimately leading to osteosclerosis in the rats.

Polystyrene microplastics induce apoptosis in chicken testis via crosstalk between NF-κB and Nrf2 pathways

Microplastics (MPs) are a new type of pollutants that are widespread in nature, and their toxic effects on humans or animals are receiving attention. Birds are in a higher ecological niche in nature, and MPs may have potential bioaccumulation and biomagnification risks to birds. The mechanisms underlying the reproductive toxicity of MPs to birds are mainly unknown. To study the reproductive toxicity of MPs to birds, we randomly divided chickens into six groups and exposed polystyrene microplastics (PS-MPs) through drinking water (0, 1, and 100 mg/L) for 28 and 42 days. We found that PS-MPs caused testicular inflammatory infiltration and interstitial hemorrhage, resulting in testicular tissue damage; the expression of Claudin3 and Occludin in the blood-testis barrier (BTB) decreased and may damage the integrity of the BTB. PS-MPs exposure inhibited the expression of the Nrf2-Keap1 pathway, which in turn reduced HO-1 and NQO1, simultaneous GSH and T-AOC were also reduced, resulting in an imbalance of the redox system; in addition, the NF-κB signaling pathway was activated, increasing the expression of TNF-α, COX-2 and iNOS. Under redox system imbalance and inflammatory stress, exposure to PS-MPs led to decreased expression of Bcl-2 and increased Bax, cytc, caspase-8, and caspase-3, etc., activating apoptosis, and ultimately causing testicular damage. These results suggested that PS-MPs exposure led to an imbalance of the redox system and an inflammatory response, inducing both endogenous and exogenous apoptosis, resulting in testicular tissue damage. Our study provides a theoretical basis for reproductive injury mechanisms in chicken.

Secondary brain injury after polystyrene microplastic-induced intracerebral hemorrhage is associated with inflammation and pyroptosis

Unlike regular environmental pollutants, microplastics cannot dissolve in liquids. Physical contact of microplastic (MPs) with tissue can damage tissue structure, and it is unclear how this physical secondary injury affects brain tissue. Through CTD database analysis, it was determined that cerebral ischemia may be one of the main ways of brain tissue damage caused by MPs, and inflammatory response may play a key role in it. In the present study, PS-MPs (L-PS group:1 mg/L, M - PS group:10 mg/L, H-PS group: 100 mg/L in water) were assessed to brain tissue damage in chicken after six weeks of continuous exposure. Exposure to PS-MPs caused cerebral hemorrhage as well as generation of microthrombi and loss of Purkinje cells. Intracerebral hemorrhage caused a strong infiltration of inflammatory cells and activated the ASC-NLRP3-GSDMD signaling pathway to induce pyroptosis. Disruption of mitochondrial dynamics by PS-MPs exposure disrupts mitochondrial function and activates AMPK signaling. In conclusion, this study explored the mechanism regulation of subsequent brain injury from the perspective of physical injury (cerebral hemorrhage) of PS-MPs. To provide a reference for elucidating the neurotoxicity induced by microplastic exposure.

ROS-mediated PPAR/RXR inhibition contributes to acetochlor-induced apoptosis and autophagy in Ctenopharyngodon idella hepatic cells

Acetochlor is a high-volume herbicide whose widespread use threatens ecosystems and affects aquaculture. Apoptosis and autophagy are important causes of hepatotoxicity caused by toxicants, which can be mediated by oxidative stress and the inhibition of PPAR/RXR pathway. However, the mechanism of acetochlor on fish hepatocyte damage still needs to be further investigated. Therefore, we treated the Ctenopharyngodon idella hepatic cell line (L8824 cells) with different concentrations (10, 20, and 40 μM) of acetochlor and/or ROS scavenger NAC (1 mM) for 24 h. The results showed that acetochlor decreased the cell viability in a dose-dependent manner. AO/EB staining and flow cytometry verified the increased apoptotic rates. Quantitative analysis of gene expression levels or protein expression levels displayed that the expression levels of Beclin1, P62, LC3B, BAX, and cleaved Casp3 were increased, and the expression of BCL2 was reduced. Besides, we detected the increased ROS contents and decreased PPAR/RXR pathway expressions after acetochlor treatment. The clearance of ROS alleviated the inhibition of the PPAR/RXR pathway and lightened apoptosis and autophagy under acetochlor stress. Overall, these results revealed that acetochlor exposure triggered BCL2/BAX/Casp3-cascaded apoptosis and Beclin1-dependent autophagy through ROS-mediated PPAR/RXR inhibition. The results partially explain the toxicological mechanism of acetochlor and provide targets for the development of its antidote.

The decrease of selenoprotein K induced by selenium deficiency in diet improves apoptosis and cell progression block in chicken liver via the PTEN/PI3K/AKT pathway

Selenoprotein K (SELK) is imperative for normal development of chicken. It does regulate to chicken's physiological function. However, the injury of SELK-deficiency done on chicken liver and its underlying mechanism involved has not yet been covered. Therefore, we built SELK- deficiency model by feeding diet which contained low concentration of selenium (Se) to discuss SELK's regulation mechanism. Through using TUNEL, TEM, western blot and qRT-PCR we found apoptosis occurred in chicken liver in the SELK-deficiency groups. In the meanwhile, our study showed there were differentially expressed of the PTEN/PI3K/AKT pathway, calcium homeostasis, endoplasmic reticulum healthy and cell cycle progression in SELK-deficiency chicken liver tissues. In order to claim the regulation mechanism of SELK, we set SELK-knock down model in the LMH. The results in vitro were coincided with those in vivo. In the SELK-deficiency groups, the PTEN/PI3K/AKT pathway was activated and then induced ERS which eventually resulted in apoptosis in chicken liver. As the same time, the PTEN/PI3K/AKT pathway also regulated the combined effective of MDM2-p53, which leaned liver cells to G1/S blocking. Our findings support the potential of SELK in maintain the health of chicken liver, and indicate that adding proper amount of Se on the daily dietary may alleviate the deficiency of selenium.