Mitochondrial miR-12294-5p-Regulated Copper Exposure-Caused Mitochondrial-Dependent Ferroptosis by Targeted Inhibition of CISD1 in Chicken Hepatocytes

Copper (Cu) is a common trace element additive in animal and human foods, and excessive intake of Cu has been shown to cause hepatotoxicity, but the underlying mechanism remains unclear. Our previous research found that Cu exposure dramatically upregulated mitochondrial miR-12294-5p expression and confirmed its targeted inhibition of CISD1 expression in chicken hepatocytes. Thus, we aimed to explore the potential role of mitomiR-12294-5p/CISD1 axis in Cu exposure-resulted hepatotoxicity. Here, we observed that Cu exposure resulted in Cu accumulation and pathological injury in chicken livers. Moreover, we found that Cu exposure caused mitochondrial-dependent ferroptosis in chicken hepatocytes, which were prominent on the increased mitochondrial Fe2+ and mitochondrial lipid peroxidation, inhibited levels of CISD1, GPX4, DHODH, and IDH2, and also enhanced level of PTGS2. Notably, we identified that inhibition of mitomiR-2954 level effectively mitigated Cu-exposure-resulted mitochondrial Fe2+ accumulation and mitochondrial lipid peroxidation and prevented the development of mitochondrial-dependent ferroptosis. However, increasing the mitomiR-12294-5p expression considerably aggravated the influence of Cu on these indicators. Meanwhile, the overexpression of CISD1 effectively alleviated Cu-caused mitochondrial-dependent ferroptosis, while silent CISD1 eliminated the therapeutic role of mitomiR-12294-5p inhibitor. Overall, our findings indicated that mitomiR-12294-5p/CISD1 axis played a critical function in Cu-caused hepatotoxicity in chickens by regulating mitochondrial-dependent ferroptosis.

Novel circular RNA Sestrin1 promotes chicken myoblast proliferation and differentiation via circSesn1/miR-16-5p/SESN1 pathway

1. The development of chicken skeletal muscle is directly relevant to poultry husbandry production. Numerous studies have suggested that circular RNA play pivotal roles in muscle development. However, the functions and mechanisms of most circRNA in chicken myogenesis remain largely unknown.2. This study identified a novel circSESN1 based on existing sequencing data and examined its authenticity and subcellular localisation by enzyme digestion and RNA fluorescence in situ hybridisation. Additionally, there was a positive correlation between the expression levels of circSESN1 and the developmental stage of chicken muscle.3. Mechanistically, knockdown or overexpression of circSESN1 was performed in primary myoblasts to validate its function. The interactions between circSESN1, miR-16-5p, and the target gene sestrin 1 (SESN1) were investigated using bioinformatics analysis and a dual fluorescein reporter system. Real-time qPCR, a cell proliferation assay, and immunofluorescence staining techniques were used to investigate the promotion effect of circSESN1 on myoblast proliferation and differentiation by miR-16-5p/SESN1 pathway.4. The results demonstrated that the newly identified chicken circSESN1 directly sponges gga-miR-16-5p to regulate SESN1 gene expression, promoting myoblast proliferation and differentiation.

Comprehensive analysis of changes in expression of lncRNA, microRNA and mRNA in liver tissues of chickens with high or low abdominal fat deposition

1. The liver of chickens is a dominant lipid biosynthetic tissue and plays a vital role in fat deposition, particularly in the abdomen. To determine the molecular mechanisms involved in its lipid metabolism, the livers of chickens with high (H) or low (L) abdominal fat content were sampled and sequencing on long non-coding RNA (lncRNA), messenger RNA (mRNA) and small RNA (microRNA) was performed.2. In total, 351 expressed protein-coding genes for long non-coding RNA (DEL; 201 upregulated and 150 downregulated), 400 differentially expressed genes (DEG; 223 upregulated and 177 downregulated) and 10 differentially expressed miRNA (DEM; four upregulated and six downregulated) were identified between the two groups. Multiple potential signalling pathways related to lipogenesis and lipid metabolism were identified via pathway enrichment analysis. In addition, 173 lncRNA - miRNA - mRNA interaction regulatory networks were identified, including 30 lncRNA, 27 mRNA and seven miRNA.3. These networks may help regulate lipid metabolism and fat deposition. Five promising candidate genes and two lncRNA may play important roles in the regulation of adipogenesis and lipid metabolism in chickens.

SWI/SNF family mutations in advanced NSCLC: genetic characteristics and immune checkpoint inhibitors' therapeutic implication

BACKGROUND

SWItch/Sucrose NonFermentable (SWI/SNF) mutations have garnered increasing attention because of their association with unfavorable prognosis. However, the genetic landscape of SWI/SNF family mutations in Chinese non-small-cell lung cancer (NSCLC) is poorly understood. In addition, the optimal treatment strategy has not yet been determined.

PATIENTS AND METHODS

We collected sequencing data on 2027 lung tumor samples from multiple centers in China to comprehensively analyze the genomic characteristics of the SWI/SNF family within the Chinese NSCLC population. Meanwhile, 519 patients with NSCLC from Sun Yat-sen University Cancer Center were enrolled to investigate the potential implications of immunotherapy on patients with SWI/SNF mutations and to identify beneficial subpopulations. We also validated our findings in multiple publicly available cohorts.

RESULTS

Approximately 15% of Chinese patients with lung cancer harbored mutations in the SWI/SNF chromatin remodeling complex, which were mutually exclusive to the EGFR mutations. Patients with SWI/SNFmut NSCLC who received first-line chemoimmunotherapy had better survival outcomes than those who received chemotherapy alone (median progression-free survival: 8.70 versus 6.93 months; P = 0.028). This finding was also confirmed by external validation using the POPLAR/OAK cohort. SWI/SNFmut NSCLC is frequently characterized by high tumor mutational burden and concurrent TP53 or STK11/KEAP mutations. Further analysis indicated that TP53 and STK11/KEAP1 mutations could be stratifying factors in facilitating personalized immunotherapy and guiding patient selection.

CONCLUSIONS

This study provides a step forward in understanding the genetic and immunological characterization of SWI/SNF genetic alterations. Moreover, our study reveals substantial benefits of immunotherapy over chemotherapy for SWI/SNF-mutant patients, especially the SWI/SNFmut and TP53mut subgroups.

Polystyrene nanoplastics and cadmium co-exposure aggravated cardiomyocyte damage in mice by regulating PANoptosis pathway

Micro/nanoplastics (M/NPs) are the novel contaminants ubiquitous in the environment. Cadmium (Cd), a kind of heavy metal pollutant widely distributed, could potentially co-exist with PS-NPs in the environment. However, their combined effects on cardiomyocyte and its molecular mechanism in mammals remained ambiguous. Here, we examined whether PANoptosis, an emerging and complicated kind of programmed cell death, was involved in PS-NPs and Cd co-exposure-elicited cardiac injury. In this study, 60 male mice were orally subjected to environmentally relevant concentrations of PS-NPs (1 mg/kg) and/or CdCl2 (1.5 mg/kg) for 35 days. As we speculated, PS-NPs and Cd co-exposure affected the expression of pyroptosis(Caspase-1, Cleaved-Caspase-1, GSDMD, N-GSDMD, AIM2, Pyrin, NLRP3, IL-18, IL-1β)-, apoptosis(Caspase-3, Cleaved-Caspase-3, Caspase-8, Cleaved-Caspase-8, Caspase-7, BAX)- and necroptosis (t-RIPK3, p-RIPK3, t-RIPK1, p-RIPK1, t-MLKL, p-MLKL, ZBP1)-related genes and protein, resulting in growth restriction and damaged myocardial microstructure in mice. Notably, the combined effects on Cd and PS-NPs even predominantly aggravated the toxic damage. Intriguingly, we fortuitously discovered PS-NPs and/or Cd exposure facilitated linear ubiquitination of certain proteins in mice myocardium. In summation, this study shed light toward the effects of Cd and PS-NPs on cardiotoxicity, advanced the understanding of myocardial PANoptosis and provided a scientific foundation for further exploration of the combined toxicological effects of PS-NPs and heavy metals.

Mitochondrial derived vesicle-carrying protein MIGA2 promotes copper-induced autophagosomes-lysosomes fusion by regulating ATG14

As an environmental pollution metal, copper (Cu) exposure-induced toxicity is closely related to mitochondrial damage. Mitochondrial-derived vesicles (MDVs) plays an essential role in mitochondrial quality control and cellular metabolism. However, the mechanism by which MDVs are involved in cellular metabolism under Cu exposure remains unclear. Here, the MDV-carrying protein MIGA2 was identified as a crucial molecule involved in the Cu-induced autophagosomes-lysosomes fusion. Furthermore, Cu exposure significantly promoted MDVs secretion, accompanied by a markedly increased MIGA2 expression in MDVs, as well as accelerated the autophagosomes-lysosomes fusion. However, small RNA interference of SNX9 (the MDVs secretion inductor) and MIGA2 blocked autophagic flux induced by Cu, leading to failure of autophagosomes degradation. Co-immunoprecipitation assay further demonstrated that ATG14 was a regulation target protein of MIGA2. Overexpression and knockdown of ATG14 significantly affected the autophagosomes-lysosomes fusion induced by Cu. Meanwhile, knockdown of ATG14 dramatically reversed the effect of MIGA2-overexpression in promoting autophagosomes-lysosomes fusion, while overexpression of ATG14 shows the opposite effect. These results demonstrated that MDVs-carrying MIGA2 protein promoted autophagosomes-lysosomes fusion induced by Cu. This study demonstrated that MDVs is involved in regulating organelles-to-organelles communication, providing a new insight into the toxicity mechanism of Cu exposure on hepatocytes.

Long-term Cu exposure alters CYP450s activity and induces jejunum injury and apoptosis in broilers

Copper (Cu) is an essential trace element that plays a crucial role in numerous physiopathological processes related to human and animal health. In the poultry industry, Cu is used to promote growth as a feed supplement, but excessive use can lead to toxicity on animals. Cytochrome P450 enzymes (CYP450s) are a superfamily of proteins that require heme as a cofactor and are essential for the metabolism of xenobiotic compounds. The purpose of this study was to explore the influence of exposure to Cu on CYP450s activity and apoptosis in the jejunum of broilers. Hence, we first simulated the Cu exposure model by feeding chickens diets containing different amounts of Cu. In the present study, histopathological observations have revealed morphological damage to the jejunum. The expression levels of genes and proteins of intestinal barrier markers were prominently downregulated. While the mRNA expression level of the gene associated with CYP450s was significantly increased. Additionally, apoptosis-related genes and proteins (Bak1, Bax, Caspase-9, Caspase-3, and CytC) were also significantly augmented by excessive Cu, while simultaneously decreasing the expression of Bcl-2. It can be concluded that long-term Cu exposure affects CYP450s activity, disrupts intestinal barrier function, and causes apoptosis in broilers that ultimately leads to jejunum damage.

Copper Exposure Induced Chicken Hepatotoxicity: Involvement of Ferroptosis Mediated by Lipid Peroxidation, Ferritinophagy, and Inhibition of FSP1-CoQ10 and Nrf2/SLC7A11/GPX4 Axis

Copper (Cu) is one of the most significant trace elements in the body, but it is also a widespread environmental toxicant health. Ferroptosis is a newly identified programmed cell death, which involves various heavy metal-induced organ toxicity. Nevertheless, the role of ferroptosis in Cu-induced hepatotoxicity remains poorly understood. In this study, we found that 330 mg/kg Cu could disrupt the liver structure and cause characteristic morphological changes in mitochondria associated with ferroptosis. Additionally, Cu treatment increased MDA (malondialdehyde) and LPO (lipid peroxide) production while reducing GSH (reduced glutathione) content and GCL (glutamate cysteine ligase) activity. However, it is noticeable that there were no appreciable differences in liver iron content and key indicators of iron metabolism. Meanwhile, our further investigation found that 330 mg/kg Cu-exposure changed multiple ferroptosis-related indicators in chicken livers, including inhibition of the expression of SLC7A11, GPX4, FSP1, and COQ10B, whereas enhances the levels of ACLS4, LPCAT3, and LOXHD1. Furthermore, the changes in the expression of NCOA4, TXNIP, and Nrf2/Keap1 signaling pathway-related genes and proteins also further confirmed 330 mg/kg Cu exposure-induced ferroptosis. In conclusion, our results indicated that ferroptosis may play essential roles in Cu overload-induced liver damage, which offered new insights into the pathogenesis of Cu-induced hepatotoxicity.

Correlation of caecal microbiome endotoxins genes and intestinal immune cells in Eimeria tenella infection based on bioinformatics

Introduction

The infection with Eimeria tenella (ET) can elicit expression of various intestinal immune cells, incite inflammation, disrupt intestinal homeostasis, and facilitate co-infection with diverse bacteria. However, the reciprocal interaction between intestinal immune cells and intestinal flora in the progression of ET-infection remains unclear.

Objective

The aim of this study was to investigate the correlation between cecal microbial endotoxin (CME)-related genes and intestinal immunity in ET-infection, with subsequent identification of hub potential biomarker and immunotherapy target.

Methods

Differential expression genes (DEGs) within ET-infection and hub genes related to CME were identified through GSE39602 dataset based on bioinformatic methods and Protein-protein interaction (PPI) network analysis. Moreover, immune infiltration was analyzed by CIBERSORT method. Subsequently, comprehensive functional enrichment analyses employing Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway analysis along with Gene Ontology (GO), gene set enrichment analysis (GSEA), and gene set variation analysis (GSVA) were performed.

Results

A total of 1089 DEGs and 25 hub genes were identified and CXCR4 was ultimately identified as a essential CME related potential biomarker and immunotherapy target in the ET-infection. Furthermore, activated natural killer cells, M0 macrophages, M2 macrophages, and T regulatory cells were identified as expressed intestinal immune cells. The functional enrichment analysis revealed that both DEGs and hub genes were significantly enriched in immune-related signaling pathways.

Conclusion

CXCR4 was identified as a pivotal CME-related potential biomarker and immunotherapy target for expression of intestinal immune cells during ET-infection. These findings have significant implications in elucidating the intricate interplay among ET-infection, CME, and intestinal immunity.

Gut microbiota disorders aggravate terbuthylazine-induced mitochondrial quality control disturbance and PANoptosis in chicken hepatocyte through gut-liver axis

Terbuthylazine (TBA) is a widely prevalent pesticide pollutant, which is a global concern due to its environmental residual. However, the toxic mechanism of TBA have not been fully solved. Here, we explored that TBA exposure disrupts the intestinal flora and aggravated disturbance of mitochondrial quality control and PANapoptosis in hepatocytes via gut-liver axis. Our findings demonstrated that TBA exposure induced significant damage to the jejunum barrier, evidenced by a marked decrease in the expression of Occludin and ZO-1. Moreover. TBA led to intestinal microflora disorder, manifested as the decreased abundance of Firmicutes, and increased abundance of the Nitrospirota, Chloroflexi, Desulfobacterota, Crenarchaeota, Myxococcota, and Planctomycetota. Meanwhile, intestinal microflora disorder affected the biological processes of lipid metabolism and cell growth and death of hepatocytes by RNA-Seq analysis. Furthermore, TBA could induced mitochondrial quality control imbalance, including mitochondrial redox disorders, lower activity of mitochondrial fusion and biogenesis decrease, and increasing level of mitophagy. Subsequently, TBA significantly increased expression levels of pyroptosis, apoptosis and necroptosis-related proteins. In general, these results demonstrated the underlying mechanisms of TBA-induced hepatotoxicity induced via the gut-liver axis, which provides a theoretical basis for further research of ecotoxicology of TBA.

Multi-omics reveals the protective effects of curcumin against AFB1-induced oxidative stress and inflammatory damage in duckling intestines

Aflatoxin B1 (AFB1) is the most prevalent and toxic class of aflatoxins, which is considered a significant risk factor for food safety. Curcumin, a phytoconstituent with anti-inflammatory and antioxidant properties, has potential therapeutic value for intestinal inflammatory diseases. In this study, the duckling model susceptible to AFB1 was selected for toxicity testing, aiming to explore the effect of curcumin on AFB1 enterotoxicity and its possible mechanism of action. The results showed that curcumin promoted the growth and development of ducklings and mitigated the changes in morphology and permeability serological index (DAO and D-LA) after AFB1 exposure. Curcumin also mitigated AFB1-induced oxidative stress by activating the Nrf2 pathway, and ameliorated intestinal inflammation by inhibiting the NF-κB/IκB signaling pathway and boosting intestinal autophagy. In terms of gut flora and their metabolites, we found that curcumin supplementation significantly increased the intestinal flora's abundance index and diversity index compared to the AFB1 group, mitigating the decline in the abundance of Actinobacteria and the rise in that of harmful bacteria Clostridia. Furthermore, untargeted metabolomic analysis revealed that the protective effect of curcumin on the intestine was mainly through the regulation of AFB1-induced disorders of lipid metabolism, involving linoleic acid metabolism, α-linolenic acid metabolism, and glycerolipid metabolism. Overall, the enteroprotective effects of curcumin may be of significant value in the future for treating chronic AFB1 poisoning and also provide new therapeutic ideas for other mycotoxicosis.

MitomiR-1736-3p regulates copper-induced mitochondrial pathway apoptosis by inhibiting AATF in chicken hepatocytes

Copper (Cu) is a toxic heavy metal pollutant. The hepatic toxicity of Cu has attracted widespread attention from researchers. However, its underlying mechanism remains elusive. Mitochondrial microRNAs (mitomiRs) are considered important factors in regulating mitochondrial and cellular functions, and their roles have been implicated in the mechanisms of metal toxicity. Therefore, this research revealed the changes in the mitomiRs expression profile of chicken liver after Cu exposure. It was ultimately determined that mitomiR-1736-3p can be involved in Cu-induced chicken liver damage by targeting AATF. In particular, our investigations have uncovered that exposure to Cu can trigger heightened levels of apoptosis in the hepatic tissue of chickens and primary chicken embryo hepatocytes (CEHs). It is noteworthy that we found upregulation of miR-1736-3p expression can exacerbate Cu-induced cell apoptosis, while inhibition of miR-1736-3p can effectively reduce apoptosis occurrence. Subsequently, we found that Cu-induced cell apoptosis could be restored by overexpressing AATF, while silencing AATF exacerbated the level of apoptosis. Fascinatingly, this change in apoptotic level is directly influenced by AATF on Bax and Bak1, rather than on p53 and Bcl-2. Overall, these findings suggest that the mitomiR-1736-3p/AATF axis mediates the mitochondrial pathway of cell apoptosis potentially involved in Cu-induced chicken liver toxicity.

Mitochondrial DNA release mediated by TFAM deficiency promotes copper-induced mitochondrial innate immune response via cGAS-STING signalling in chicken hepatocytes

Copper (Cu) is pollution metal that is a global concern due to its toxic effects. A recent study found that the release of mitochondrial DNA (mtDNA) into the cytoplasm can activate the innate immune response, but the exact mechanisms underlying the effect of Cu exposure remains unknown. In this study, we identified that the reduction in transcription Factor A (TFAM) led to mtDNA leakage into the cytoplasm under Cu exposure in hepatocytes, accompanied by the activation of the cyclic GMP-AMP synthase-stimulator of interferon genes (cGAS-STING) pathway-mediated innate immunity (increased expression of cGAS, STING, TANK-binding kinase-1 (TBK1), and interferon regulatory factor-3 (IRF3)) genes and proteins, and enhanced phosphorylation levels of TBK1 and IRF3). Subsequently, silencing TFAM (siTFAM) significantly aggravated mtDNA release and the innate immune response under Cu treatment. Mitochondrial DNA depletion alleviated Cu-induced innate immunity in hepatocytes, while mtDNA transfection further enhanced the innate immune response. Notably, the inhibition of STING effectively alleviated the phosphorylation levels of the TBK1 and IRF3 proteins induced by Cu, while the upregulation of STING aggravated the Cu-induced innate immunity. Furthermore, EtBr and H-151(a STING inhibitor) treatment dramatically reversed the effect of TFAM depletion on the sharpened innate immune response induced by Cu via the cGAS-STING pathway. In general, these findings demonstrated the TFAM deficiency promotes innate immunity by activating the mtDNA-cGAS-STING signalling pathway under Cu exposure in hepatocytes, providing new insight into Cu toxicology.

Effect of Copper Exposure on the Cholesterol Metabolism in Broiler Liver

Copper (Cu) is a kind of widely used dietary supplement in poultry production, and a common environmental pollutant at the same time. Excess Cu exposure has been reported to accumulate in the liver and induce cytotoxicity, but the effect of Cu toxicity on hepatic cholesterol metabolism is still uncertain. Herein, we aimed to reveal the effect of excess Cu on the liver and primary hepatocytes of broilers at various concentrations. We found that 110 mg/kg Cu supplement remarkably increased blood cholesterol levels by detecting serum TC, LDL-C, and HDL-C in the broilers, while there was no significant difference in 220 and 330 mg/kg Cu supplements. In addition, high Cu exposure resulted in severe hepatic steatosis and hepatic cord derangement in the broilers. Oil red O staining of primary hepatocytes showed that Cu treatment caused intracellular neutral lipid accumulation. However, the hepatic TC content indicated a downward trend in both liver tissues and hepatocytes after Cu exposure. Furthermore, the expression of cholesterol metabolism-related indicators (SREBP2, HMGCR, LDLR, and CYP7A1) was notably decreased in the Cu-treated groups. While the expression of the key enzyme of cholesterol esterification (ACAT2) did not change significantly. Taken together, our findings preliminarily revealed excess Cu-induced hepatic cholesterol metabolism dysfunction, providing a deeper understanding of the molecular mechanisms of Cu-induced hepatotoxicity.

N-acetylcysteine combined with insulin attenuates myocardial injury in canines with type 1 diabetes mellitus by modulating TNF-α-mediated apoptotic pathways and affecting linear ubiquitination

The exact pathogenesis of type 1 diabetes mellitus (DM) is still unclear. Numerous organs, including the heart, will suffer damage and malfunction as a result of long-term hyperglycemia. Currently, insulin therapy alone is still not the best treatment for type 1 DM. In order to properly treat and manage patients with type 1 DM, it is vital to seek a combination that includes both insulin and additional medications. This study aims to explore the therapeutic effect and mechanism of N-acetylcysteine (NAC) combined with insulin on type 1 DM. By giving beagle canines injections of streptozotocin (STZ) and alloxan (ALX) (20 mg/kg each), a model of type 1 DM was created. The results showed that this combination could effectively control blood sugar level, improve heart function, avoid the damage of mitochondria and myocardial cells, and prevent the excessive apoptosis of myocardial cells. Importantly, the combination can activate nuclear factor kappa-B (NF-κB) by promoting linear ubiquitination of receptor-interacting protein kinase 1 (RIPK1) and NF-κB-essential modulator (NEMO) and inhibitor of NF-κB (IκB) phosphorylation. The combination can increase the transcription and linear ubiquitination of Cellular FLICE (FADD-like IL-1β-converting enzyme) -inhibitory protein (c-FLIP), diminish the production of cleaved-caspase-8 p18 and cleaved-caspase-3 to reduce apoptosis. This study confirmed that NAC combined with insulin can promote the linear ubiquitination of RIPK1, NEMO and c-FLIP and regulate the apoptosis pathway mediated by TNF-α to attenuate the myocardial injury caused by type 1 DM. Meanwhile, the research served as a resource when choosing a clinical strategy for DM cardiac complications.

Terbuthylazine exposure induces innate immune response and inflammation through activating cGAS-STING/NF-κB pathway in myocardium of broiler chicken (Gallus gallus)

Terbuthylazine (TBA), a triazine herbicide, is extensively employed in agriculture for its wide range of effectiveness. However, prolonged utilization of TBA can pose a potential hazard to animals and human health. Here, a total of 180 broiler chickens (Gallus gallus) were stochastically assigned to three groups (control group, 0.4 mg/kg TBA group, and 4 mg/kg TBA group) for investigating the impact of TBA on cardiotoxicity. The results revealed that TBA exposure resulted in pathological alterations in the myocardium. Moreover, TBA exposure activated cGAS-STING pathway and markedly elevated the mRNA and protein expression levels of innate immune response (cGAS, STING, TBK1, and IRF3) in myocardium. Additionally, NF-κB signal was also activated under TBA exposure, which was characterized by the increasing mRNA expression levels of NF-κB, IKKα and the protein expression levels of p-NF-κB/NF-κB, IKKα, p-IκBα/IκBα in the TBA treatment groups. Meanwhile, the expression of pro-inflammatory cytokines (TNF-α and IL-1β) were also significantly increased. In summary, our findings suggested that cGAS-STING/NF-κB pathway functionated in the innate immune response and inflammation in myocardium brought on by TBA exposure, which provided new insights into the TBA toxicology.

miR-181b-1-3p affects the proliferation and differentiation of chondrocytes in TD broilers through the WIF1/Wnt/β-catenin pathway

Thiram is a plant fungicide, its excessive use has exceeded the required environmental standards. It causes tibial dyschondroplasia (TD) in broilers which is a common metabolic disease that affects the growth plate of tibia bone. It has been studied that many microRNAs (miRNAs) are involved in the differentiation of chondrocytes however, their specific roles and mechanisms have not been fully investigated. The selected features of tibial chondrocytes of broilers were studied in this experiment which included the expression of miR-181b-1-3p and the genes related to WIF1/Wnt/β-catenin pathway in chondrocytes through qRT-PCR, western blot and immunofluorescence. The correlation between miR-181b-1-3p and WIF1 was determined by dual luciferase reporter gene assay whereas, the role of miR-181b-1-3p and WIF1/Wnt/β-catenin in chondrocyte differentiation was determined by mimics and inhibitor transfection experiments. Results revealed that thiram exposure resulted in decreased expression of miR-181b-1-3p and increased expression of WIF1 in chondrocytes. A negative correlation was also observed between miR-181b-1-3p and WIF1. After overexpression of miR-181b-1-3p, the expression of ACAN, β-catenin and Col2a1 increased but the expression of GSK-3β decreased. It was observed that inhibition of WIF1 increased the expression of ALP, β-catenin, Col2a1 and ACAN but decreased the expression of GSK-3β. It is concluded that miR-181b-1-3p can reverse the inhibitory effect of thiram on cartilage proliferation and differentiation by inhibiting WIF1 expression and activating Wnt/β-catenin signaling pathway. This study provides a new molecular target for the early diagnosis and possible treatment of TD in broilers.

Effects of terbuthylazine on myocardial oxidative stress and ferroptosis via Nrf2/HO-1 signaling pathway in broilers

Terbuthylazine (TBA) is one of the most commonly used and effective herbicides. However, due to its affinity for soil organic matter and water solubility, TBA can lead to biological health concerns. This study exposed broilers to TBA (0 mg/kg bw, 0.4 mg/kg bw, 4 mg/kg bw) for 28 days. The results showed significant pathological damage in broiler myocardial tissue, such as widening of the interstitial space, rupture of muscle fibers, and deposition of myocardial collagen fibers. In addition, Under the 0.4 mg/kg bw TBA exposure, myocardial oxidative stress was observed in broilers, which was accompanied by the activation of Nrf2/HO-1 pathway and the increased protein and mRNA levels of NQO1, NOX2 and SOD2 antioxidant enzymes. However, Nrf2/HO-1 protein and mRNA levels were reversed at 4 mg/kg bw TBA exposure. Meanwhile, the Nrf2/HO-1 mediated antioxidant defense was impaired. In contrast with the low dose, the protein and gene expression levels of NQO1, NOX2, and SOD2 were reduced in 4 mg/kg bw TBA group. The expression of GPX4 and SLC7A11 was significantly downregulated at both protein and mRNA levels. Beyond that, ACSL4 expression was significantly up-regulated, and the protein result was consistent with the mRNA expression, demonstrating the occurrence of ferroptosis. In general, TBA exposure activated the Nrf2/HO-1 pathway, resulting in ferroptosis. This study links ferroptosis to the Nrf2/HO-1 pathway, providing new insights into the potential role of TBA in myocardial toxicity.

Exposure to copper induces endoplasmic reticulum (ER) stress-mediated apoptosis in chicken (Gallus gallus) myocardium

Copper (Cu), an omnipresent environmental pollutant, can cause potential harm to the public and ecosystems. In order to study the cardiotoxicity caused by Cu, molecular biology techniques were used to analyze the effect of Cu on ER stress-mediated cardiac apoptosis. In vivo investigation, 240 1-day-old chickens were fed with Cu (11, 110, 220, and 330 mg/kg) diet for 7 weeks. The consequence showed that high-Cu can induce ER stress and apoptosis in heart tissue. The vitro experiments, the Cu treatment for 24 h could provoke ultrastructural damage and upregulate the apoptosis rate. Meanwhile, GRP78, GRP94, eIF2α, ATF6, XBP1, CHOP, Bax, Bak1, Bcl2, Caspase-12 and Caspase-3 genes levels, and GRP78, GRP94 and Caspase-3 proteins levels were increased, which indicated that ER stress and apoptosis in cardiomyocytes. But the mRNA level of Bcl2 were decreased after Cu exposure. Conversely, Cu-induced ER stress-mediated apoptosis can be alleviated by treatment with 4-PBA. These findings generally showed that Cu exposure can contribute to ER stress-mediated apoptosis in chicken myocardium, which clarifies the important mechanism link between ER stress and apoptosis, and provides a new perspective for Cu toxicology.

Long-term oral tribasic copper chloride exposure impedes cognitive function and disrupts mitochondrial metabolism by inhibiting mitophagy in rats

Copper (Cu) is an essential micronutrient element that commonly acted as a feed additive and antimicrobial in agricultural production. Tribasic copper chloride (TBCC) is a relatively new dietary Cu source, and its exposure directly or indirectly affects the safety of animals and ecological environment, thus posing a potential risk to human health. Cu overexposure would produce toxic reactive oxygen species (ROS) that may have toxic effects on the host, but the mechanism of neurotoxicity remains unclear. Herein, to explore the effects of long-term TBCC-induced neurotoxicity, 150 male Sprague-Dawley rats were randomly allocated and treated with different doses of TBCC, and the cortical and hippocampus tissues were harvested at 0, 6, and 12 weeks after treatment. Morris Water Maze (MWM) test showed that excessive intake of TBCC could induce cognitive dysfunction in rats. Moreover, after treatment with 160 mg/kg Cu (276 mg/kg TBCC) for 12 weeks, pathological changes were observed in the cortex and hippocampus, and the number of Nissl bodies decreased significantly in the hippocampus. Additionally, mitochondrial structure was significantly altered and neuronal mitochondrial fusion/fission equilibrium was disrupted in 80 mg/kg and 160 mg/kg Cu groups at 12 weeks. With an increase in TBCC dose and treatment time, the number of mitophagosomes and the expression of mitophagy-related genes were significantly decreased after initially increasing. Furthermore, metformin (Met) and 3-methyladenine (3-MA) were used to regulate the level of mitophagy to further explore the mechanism of Cu-induced nerve cell injury in vitro., and it found that mitophagy activator (Met) would increase mitochondrial fission, while mitophagy inhibitors (3-MA) would aggravate mitochondrial metabolic disorders by promoting mitochondrial fusion and inhibiting mitochondrial division. These results indicate that long-term oral TBCC could impede cognitive function and disrupts mitochondrial metabolism by inhibiting mitophagy, providing an insightful perspective on the neurotoxicity of dietary TBCC.

Co-exposure to environmentally relevant concentrations of cadmium and polystyrene nanoplastics induced oxidative stress, ferroptosis and excessive mitophagy in mice kidney

Nanoplastics (NPs) are defined as a group of emerging pollutants. However, the adverse effect of NPs and/or heavy metals on mammals is still largely unclear. Therefore, we performed a 35-day chronic toxicity experiment with mice to observe the impacts of exposure to Cadmium (Cd) and/or polystyrene nanoplastics (PSNPs). This study revealed that combined exposure to Cd and PSNPs added to the mice's growth toxicity and kidney damage. Moreover, Cd and PSNPs co-exposure obviously increased the MDA level and expressions of 4-HNE and 8-OHDG while decreasing the activity of antioxidase in kidneys via inhibiting the Nrf2 pathway and its downstream genes and proteins expression. More importantly, the results suggested for the first time that Cd and PSNPs co-exposure synergistically increased iron concentration in kidneys, and induced ferroptosis through regulating expression levels of SLC7A11, GPX4, PTGS2, HMGB1, FTH1 and FTL. Simultaneously, Cd and PSNPs co-exposure further increased the expression levels of Pink, Parkin, ATG5, Beclin1, and LC3 while significantly reducing the P62 expression level. In brief, this study found that combined exposure to Cd and PSNPs synergistically caused oxidative stress, ferroptosis and excessive mitophagy ultimately aggravating kidney damage in mice, which provided new insight into the combined toxic effect between heavy metals and PSNPs on mammals.

Mitochondrial miR-12294-5p regulated copper-induced mitochondrial oxidative stress and mitochondrial quality control imbalance by targeted inhibition of CISD1 in chicken livers

Copper (Cu) is hazardous metal contaminant, which induced hepatotoxicity is closely related to mitochondrial disorder, but exact regulatory mechanism has not yet been revealed. Mitochondrial microRNAs (mitomiRs) are a novel and critical regulator of mitochondrial function and mitochondrial homeostasis. Hence, this study revealed the impact of Cu-exposure on mitomiR expression profiles in chicken livers, and further identified mitomiR-12294-5p and its target gene CISD1 as core regulators involved in Cu-induced hepatotoxicity. Additionally, our results showed that Cu-exposure induced mitochondrial oxidative damage, and mitochondrial quality control imbalance mediated by mitochondrial dynamics disturbances, mitochondrial biogenesis inhibition and abnormal mitophagy flux in chicken livers and primary chicken embryo hepatocytes (CEHs). Meaningfully, we discovered that inhibition of the expression of mitomiR-12294-5p effectively alleviated Cu-induced mitochondrial oxidative stress and mitochondrial quality control imbalance, while the up-regulation of mitomiR-12294-5p expression exacerbated Cu-induced mitochondrial damage. Simultaneously, the above Cu-induced mitochondrial damage can be effectively rescued by the overexpression of CISD1, while knockdown of CISD1 dramatically reverses the mitigating effect that inhibition of mitomiR-12294-5p expression on Cu-induced mitochondrial oxidative stress and mitochondrial quality control imbalance. Overall, these results suggested that mitomiR-12294-5p/CISD1 axis mediated mitochondrial damage is a novel molecular mechanism involved in regulating Cu-induced hepatotoxicity in chickens.

N-acetylcysteine alleviates oxidative stress and apoptosis and prevents skeletal muscle atrophy in type 1 diabetes mellitus through the NRF2/HO-1 pathway

AIMS

Type 1 diabetes mellitus (T1DM) has been linked to the occurrence of skeletal muscle atrophy. Insulin monotherapy may lead to excessive blood glucose fluctuations. N-acetylcysteine (NAC), a clinically employed antioxidant, possesses cytoprotective, anti-inflammatory, and antioxidant properties. The objective of our study was to evaluate the viability of NAC as a supplementary treatment for T1DM, specifically regarding its therapeutic and preventative impacts on skeletal muscle.

MAIN METHODS

Here, we used beagles as T1DM model for 120d to explore the mechanism of NRF2/HO-1-mediated skeletal muscle oxidative stress and apoptosis and the therapeutic effects of NAC. Oxidative stress and apoptosis related factors were analyzed by immunohistochemistry, immunofluorescence, western blotting, and RT-qPCR assay.

KEY FINDINGS

The findings indicated that the co-administration of NAC and insulin led to a reduction in creatine kinase levels, preventing weight loss and skeletal muscle atrophy. Improvement in the reduction of muscle fiber cross-sectional area. The expression of Atrogin-1, MuRF-1 and MyoD1 was downregulated, while Myh2 and MyoG were upregulated. In addition, CAT and GSH-Px levels were increased, MDA levels were decreased, and redox was maintained at a steady state. The decreased of key factors in the NRF2/HO-1 pathway, including NRF2, HO-1, NQO1, and SOD1, while KEAP1 increased. In addition, the apoptosis key factors Caspase-3, Bax, and Bak1 were found to be downregulated, while Bcl-2, Bcl-2/Bax, and CytC were upregulated.

SIGNIFICANCE

Our findings demonstrated that NAC and insulin mitigate oxidative stress and apoptosis in T1DM skeletal muscle and prevent skeletal muscle atrophy by activating the NRF2/HO-1 pathway.

Mitophagy contributes to zinc-induced ferroptosis in porcine testis cells

Zinc (Zn) is a critical microelement for physiological process, but excess exposure can cause testicular dysfunction. However, the underlying mechanism of Zn-induced ferroptosis via regulating mitophagy is unknown. In this study, a total of 60 male weaned pigs were randomly divided into three groups and the content of Zn were 75 mg/kg (control), 750 mg/kg (Zn-I), 1500 mg/kg (Zn-II). Meanwhile, testicular cells were treated with ZnSO4 (0, 50 and 100 μM), and in combination of ZnSO4 (100 μM) and ferrostation-1, ML-210, or 3-methyladenine for 24 h. Our results verified that Zn could cause ferroptosis and lipid peroxidation, which were characterized by down-regulating level of SLC7A11, GPX4, and ferritin, and up-regulating levels of MDA, CD71, TF, and HMGB1 by Western blot, immunohistochemistry, immunofluorescence, peroxidase assay, et.ac. The opposite effect was shown after treatment with ferrostation-1 or ML-210. Meanwhile, the mitophagy-related proteins (PINK, Parkin, ATG5, LC3-II/LC3-I) were significantly upregulated in vivo and in vitro. Most importantly, 3-methyladenine observably relieved ferroptosis under Zn treatment through inhibiting mitophagy. Collectively, we demonstrated that mitophagy contributes to Zn-induced ferroptosis in porcine testis cells, providing a new insight into Zn toxicology.

Mitochondria-mediated apoptosis and endoplasmic reticulum stress are involved in the toxicity induced by copper in the porcine spleen

Copper (Cu) is one of the common heavy metal pollutants in the environment, and its toxic mechanisms have been extensively studied. However, the immunotoxicity induced by Cu remains rarely reported, and the effects of Cu on endoplasmic reticulum stress and mitochondria-mediated apoptosis have been little studied in the spleen. In this study, pigs were fed with different contents of Cu (10, 125, and 250 mg/kg Cu) for 80 days to establish a toxicity model. The results showed the Cu exposure triggered endoplasmic reticulum stress in the spleen, as evidenced by increased mRNA and protein levels of GRP94, GRP78, CHOP, XBP1, ATF6, and JNK; the positive rate of GRP78 increased by immunofluorescence analysis. Additionally, mitochondrial fission and fusion homeostasis were disrupted, the expression levels of mitochondrial dynamics-related genes Mfn1, Mfn2, and OPA1 decreased, DRP1 increased, and the positive rate of Mfn1 decreased by immunofluorescence analysis. Furthermore, Cu exposure could induce apoptosis, as demonstrated by the increased expression level of related proteins and genes Bak, Bax, Caspase-3, P53, and Cytc. In conclusion, these results suggest chronic Cu exposure can lead to endoplasmic reticulum stress and imbalance in mitochondrial dynamics and induced apoptosis of pig spleen, and these results provided new insights into the underlying mechanism of Cu exposure caused splenic toxicity, which has public health implications where humans and animals are exposed to copper contamination.