Complex molecular mechanism of ammonia-induced apoptosis in chicken peripheral blood lymphocytes: miR-27b-3p, heat shock proteins, immunosuppression, death receptor pathway, and mitochondrial pathway

The modulation of immune cell death in connection to microRNAs and natural products

Immunogenic cell death (ICD) spatiotemporally regulates damage-associated molecular patterns (DAMPs) derived from dying cancer cells to signal the immune response. Intriguingly, these DAMPs and cytokines also induce cellular responses in non-immune cells, particularly cancer cells. Several ICD-modulating natural products and miRNAs have been reported to regulate the DAMP, cytokine, and cell death responses, but they lack systemic organization and connection. This review summarizes the impacts of natural products and miRNAs on the DAMP and cytokine responses and cancer cell death responses (apoptosis, autophagy, ferroptosis, necroptosis, and pyroptosis). We establish the rationale that ICD inducers of natural products have modulating effects on miRNAs, targeting DAMPs and cytokines for immune and cancer cell death responses. In conclusion, DAMP, cytokine, and cell death responses are intricately linked in cancer cells, and they are influenced by ICD-modulating natural products and miRNAs.

Golgi apparatus regulated pyroptosis through the miR-32-5p/Golga7/NLRP3 axis in chicken splenic lymphocytes exposure to ammonia

Ammonia, a common toxic gas, posed a hazard to both human and chickens. The Golgi apparatus, an essential organelle, helped maintain the internal environment of the organism and supported the protein foundation for the endoplasmic reticulum to be involved in pyroptosis. Thus, the Golgi apparatus has garnered significant attention. The purpose of our research was to explore the mechanisms of Golgin A7 (Golga7) involved in pyroptosis after chicken exposure to ammonia. To reach our goal, we first created an in vitro ammonia model to study the effect of ammonia on chicken splenic lymphocyte pyroptosis. Then, leveraging this model, we established Golga7 and miR-32-5p knockdown and overexpression models to investigate their roles in ammonia-induced pyroptosis. We found the ultrastructural changes in the nucleus, Golgi apparatus, and mitochondria of chicken splenic lymphocytes exposure to ammonia. The damage of mitochondria increased the level of Reactive Oxygen Species (ROS), which caused the down-regulation of miR-32-5p. The miR-32-5p inhibitor increased the expression of Golga7 and pyroptosis-related genes (NOD-like receptor protein 3 (NLRP3), Cysteine aspartase-1 (Caspase-1), Golgin A3 (Golga3), Nuclear Factor-kappa B (NF-κB), and Tumor Necrosis Factor-alpha (TNF-α)), which induced the pyroptosis, but when miR-32-5p mimic/si-Golga7 (Golga7 inhibitor) was utilized, these effects were reduced. Our research demonstrated that miR-32-5p/Golga7 regulated NLRP3 involving in the pyroptosis of chicken splenic cells exposed to ammonia. Our study provided a valuable foundation for the prevention and treatment chickens ammonia poisoning in the livestock production.

Identification and functional analysis of circular RNA expression profiles associated with ammonia exposure in chicken lungs

Ammonia acts as a detrimental atmospheric pollutant, posing a sever threat to respiratory tract health and causing lung injury in humans and animals. Circular RNAs (circRNAs) are a distinctive class of non-coding RNA generated by back-splicing of linear RNA, implicated in various biological processes. However, their role in the immune response of chicken lungs to ammonia exposure remains unclear. In this study, we examined the expression profiles of circRNAs in chicken lungs under ammonia stimulation. In total, 61 differentially expressed (DE) circRNAs were identified between the ammonia exposure and control groups, including 17 up-regulated and 44 down-regulated circRNAs. The source genes of these DE circRNAs were predominantly enriched in Influenza A, SNARE interactions in vesicular transport, and Notch signaling pathway. Notably, nine DE circRNAs (circNBAS, circMTIF2, circXPO1, circSNX24, circRAB11A, circARID3B, circUSP54, circPPARA, and circERG) were selected for validation the reliability and authenticity of RNA-seq data. Results showed the back-splicing circular structure, as well as the reliability and accuracy of RNA-seq data in quantifying circRNA expression, as the RT-qPCR results were in agreement with the RNA-seq data. Moreover, we constructed the circRNA-miRNA-mRNA regulatory networks and identified several regulatory networks in chicken lungs under ammonia stimulation, including circRAB11A-gga-miR-191b-3p-BRD2 and circARID3B-gga-miR-1696-CKS2. Taken together, our study delineates the circRNA expression profile and their potential roles in the immune response of chicken lungs to ammonia exposure. These findings offer insights into molecular mechanisms that may mitigate diseases associated with ammonia induced respiratory tract pollution in humans and animals.

Marine thermal fluctuation induced gluconeogenesis by the transcriptional regulation of CgCREBL2 in Pacific oysters

Marine thermal fluctuation profoundly influences energy metabolism, physiology, and survival of marine life. In the present study, short-term and long-term high-temperature stresses were found to affect gluconeogenesis by inhibiting PEPCK activity in the Pacific oyster (Crassostrea gigas), which is a globally distributed species that encounters significant marine thermal fluctuations in intertidal zones worldwide. CgCREBL2, a key molecule in the regulation of gluconeogenesis, plays a critical role in the transcriptional regulation of PEPCK in gluconeogenesis against high-temperature stress. CgCREBL2 was able to increase the transcription of CgPEPCK by either binding the promoter of CgPEPCK gene or activating CgPGC-1α and CgHNF-4α after short-term (6 h) high-temperature stress, while only by binding CgPEPCK after long-term (60 h) high-temperature stress. These findings will further our understanding of the effect of marine thermal fluctuation on energy metabolism on marine organisms.

Effects of immunosuppression-associated gga-miR-146a-5p on immune regulation in chicken macrophages by targeting the IRKA2 gene

Stress-induced immunosuppression (SIIS) is one of the common problems in intensive poultry production, which brings enormous economic losses to the poultry industry. Accumulating evidence has shown that microRNAs (miRNAs) were important regulators of gene expression in the immune system. However, the miRNA-mediated molecular mechanisms underlying SIIS in chickens are still poorly understood. This study aimed to investigate the biological functions and regulatory mechanism of miRNAs in chicken SIIS. A stress-induced immunosuppression model was successfully established via daily injection of dexamethasone and analyzed miRNA expression in spleen. Seventy-four differentially expressed miRNAs (DEMs) was identified, and 229 target genes of the DEMs were predicted. Functional enrichment analysis the target genes revealed pathways related to immunity, such as MAPK signaling pathway and FoxO signaling pathway. The candidate miRNA, gga-miR-146a-5p, was found to be significantly downregulated in the Dex-induced chicken spleen, and we found that Dex stimulation significantly inhibited the expression of gga-miR-146a-5p in Chicken macrophages (HD11). Flow cytometry, 5-ethynyl-2'-deoxyuridine (EdU), cell counting kit-8 (CCK-8) and other assays indicated that gga-miR-146a-5p can promote the proliferation and inhibit apoptosis of HD11 cells. A dual-luciferase reporter assay suggested that the Interleukin 1 receptor associated kinase 2 (IRAK2) gene, which encoded a transcriptional factor, was a direct target of gga-miR-146a-5p, gga-miR-146a-5p suppressed the post-transcriptional activity of IRAK2. These findings not only improve our understanding of the specific functions of miRNAs in avian stress but also provide potential targets for genetic improvement of stress resistance in poultry.

Unveiling the hidden effects of hypoxia: Pituitary damage and hormonal imbalance in fat greenling (Hexagrammos otakii)

BACKGROUND

In fisheries, hypoxia stress is one of the most common environmental stresses that often lead to the death of large numbers of fish and cause significant economic losses. The pituitary, an important endocrine gland, lies below the hypothalamus region of the brain. It plays a crucial part in controlling vital physiological functions in fish, such as growth, reproduction, and responses to stress. However, the detailed mechanisms of how hypoxia affects these physiological processes via the pituitary remain largely unknown.

METHODS

Fat greenlings (Hexagrammous otakii) were exposed to different dissolved oxygen (DO = 7. 6 mg/L and DO = 2 mg/L) for 24 h. miRNA-mRNA association analysis of H. otakii pituitary after hypoxia stress. Detecting apoptosis in H. otakii pituitary using Tunel and qPCR. Subsequent detection of hormones in H. otakii liver, gonads and serum by ELISA.

RESULTS

In this study, hypoxia causes immune system disorders and inflammatory responses through the combined analysis of miRNAs and mRNAs. Subsequent verification indicated a significant accumulation of reactive oxygen species (ROS) subsequent to hypoxia treatment. The overproduction of ROS cause oxidative stress and apoptosis in the pituitary, ultimately causing pituitary damage and reduced growth hormone and luteinising hormone release.

CONCLUSIONS

According to the association study of miRNA-mRNA, apoptosis problems caused by hypoxia stress result in H. otakii pituitary damage. In the meantime, this work clarifies the possible impact of hypoxia-stress on the pituitary cells, as well as on the gonadal development and growth of H. otakii.

Polystyrene microplastics mediate cell cycle arrest, apoptosis, and autophagy in the G2/M phase through ROS in grass carp kidney cells

Microplastics (MPs) have attracted widespread worldwide attention as a new pollutant. However, the role of reactive oxygen species (ROS) and cell cycle in nephrotoxicity induced by different concentrations of polystyrene microplastics (PS-MPs) is unknown. This study used grass carp kidney cells (CIK) treated with different concentrations of PS-MPs (0, 0.012, 0.0625, and 0.5 mg L-1 ) as subjects. With the increase of PS-MPs concentration, the levels of ROS and malonaldehyde increased, while the level of total antioxidant capacity, superoxide Dismutase (SOD), and glutathione (GSH) activity decreased. The expression of BUB1 mitotic checkpoint serine/threonine kinase (BUB1), cyclin-dependent kinase (CDK1), CDK2, CyclinB1, cell division cycle 20 homolog (CDC20), and B-cell lymphoma-2, sequestosome 1 decreased significantly. Nevertheless, the expression of Caspase 3, Cleave-Caspase 3, cytochrome c (Cytc), BCL2-associated X, apoptosis regulator, poly ADP-ribose polymerase (PARP), Cleave-PARP, Caspase 9, autophagy immunoblot kit (LC3), and Beclin1 increased. Our research shows that PS-MPs can trigger oxidative stress and induce cell cycle arrest, apoptosis, and autophagy in CIK cells by regulating ROS. This work provides a theoretical basis for cellular biology and toxicology mechanisms and new insights into the potential risks to animals from MPs exposure in the environment.

Using heat shock protein (HSP) inducers as an approach to increase the viability of sterlet (Pisces; Acipenseridae; Acipenser ruthenus) cells against environmental diazinon toxicity

Diazinon (DZN) is an organophosphate pesticide frequently used in agriculture and released into aquatic environments. In this study, sterlet sturgeon cells were exposed to DZN to investigate possible defense mechanisms via HSP induction (HSPi). Liver, kidney, and gill cells of Acipenser ruthenus were isolated and cultured and then treated with HSPi (Pro-Tex®, amygdalin, and a novel pirano-piranazole-based synthesized compound: SZ) in the presence and absence of DZN. MTT assays were used to evaluate the effects of different HSPis and their combinations with DZN. Western blotting analysis was conducted to evaluate HSP27, HSP70, and HSP90 expression patterns in each group. The highest rates of caspase-3 and caspase-8 activities were found in the DZN group, whereas HSPi treatment resulted in the lowest rates. The combination of HSPi+DZN resulted in increased HSP levels and antioxidant parameters but decreased cortisol, immune parameters, and metabolic enzymes. Many of the studied parameters (caspases, acetylcholinesterase, antioxidant, immune, and metabolic parameters) showed significant correlations with HSP expression, indicating that HSPs may be associated with markers of sterlet cell health. The results of this study demonstrate that using HSP inducers may be a powerful and reliable way to increase A. ruthenus resistance prior to exposure to DZN.

Inhalation of ammonia promotes apoptosis and induces autophagy in hepatocytes via Bax/BCl-2 and m-TOR/ATG5/LC-3bII axes

Ammonia (NH3) is an irritating gas and atmospheric pollutant that endangers the health of humans and animals by stimulating respiratory tract's mucosa and causing liver damage. However, physiological role of ammonia gas in hepatotoxicity remains unclear. To investigate the hepatotoxic effects of inhaled ammonia gas, experiments were conducted using mouse model exposed to 100 ppm of ammonia gas for 21 days. The exposed mice exhibited signs of depression, emaciation, and reduced growth. This study revealed that inhalation of ammonia led to significant decrease in water (P < 0.0001) and food intake (P < 0.05), resulting in slower growth. Histopathological analysis showed that ammonia stress alters the microstructure of the liver by enlarging the gap between hepatic lobule and fibrosis. Moreover, ammonia-induced stress significantly reduces the expression of the anti-apoptotic protein BCl-2 (P < 0.001), while elevates the mRNA expression of the pro-apoptotic gene Bax (P < 0.001). Furthermore, ammonia inhalation significantly increases the protein expression of LC-3bII (P < 0.05) and the mRNA expression of autophagy-related gene 5 (ATG5) (P < 0.05) and p62 (P < 0.05) while remarkably decreases the mRNA expression of mammalian target of rapamycin (m-TOR) (P < 0.05). In conclusion, this study demonstrates that inhalation of ammonia gas causes liver damage and suggests autophagy happening via m-TOR/p62/LC-3bII and pro-apoptosis effect mediated by Bax/BCl-2 in the liver damage caused by ammonia inhalation. Our study provides a new perspective on ammonia-induced hepatotoxicity.

Protein lysine acetylation played an important role in NH3-induced AEC2 damage and pulmonary fibrosis in piglets

Gaseous ammonia (NH3), as a main air pollutant in pig farms and surrounding areas, directly affects animal and human health. The lung, as an important organ for gas exchange in the respiratory system, is damaged after NH3 exposure, but the underlying mechanism needs to be further explored. In this study, seven weeks old piglets were exposed to 50 ppm NH3 for 30 days, and displayed pulmonary fibrosis. Then, the toxicological mechanism of NH3-induced pulmonary fibrosis was explored from the aspects of whole genome wide protein expression and post-translational modification. Totally, 404 differentially expressed proteins (DEPs) and 136 differentially lysine acetylated proteins (DAPs) were identified. The expression or lysine acetylation levels of proteins involved in mitochondrial energy metabolism including fatty acid oxidation (CPT1A, ACADVL, ACADS, HADHA, and HADHB), TCA cycle (IDH2 and MDH2), and oxidative phosphorylation (NDUFB7, NDUFV1, ATP5PB, ATP5F1A, COX5A, and COX5B) were significantly changed after NH3 exposure, which suggested that NH3 disrupted mitochondrial energy metabolism in the lung of piglets. Next, we found that type 2 alveolar epithelial cells (AEC2) damaged after NH3 exposure in vivo and in vitro. Integrin-linked kinase (ILK) was enriched in focal adhesion pathway, and showed significantly up-regulated acetylation levels at K191 (FC = 2.99) and K209 sites (FC = 1.52) after NH3 exposure. We illustrated that ILK-K191 hyper-acetylation inhibited AEC2 proliferation and induced AEC2 apoptosis by down-regulating pAKT-S473 in vitro. In conclusion, for the first time, our study revealed that protein acetylation played an important role in the process of NH3-induced pulmonary fibrosis in piglets. Our findings provided valuable insights into toxicological harm of NH3 to human health.

HSP27-HSP40-HSP70-HSP90 pathway participated in molecular mechanism of selenium alleviating lead-caused oxidative damage and proteotoxicity in chicken Bursa of Fabricius

Lead (Pb), a toxic environmental pollutant, is hazardous to the health of humans and birds. Bursa of Fabricius (BF) is a unique organ of birds. Toxic substances can attack BF and induce proteotoxicity. Increased heat shock proteins (HSPs) can induce oxidative damage. Selenium (Se) can alleviate harmful substance-caused oxidative damage. This study aimed to investigate whether Pb can cause oxidative damage and proteotoxicity, as well as Se reverse Pb-caused chicken BF toxicity. A model of chickens treated with Se and Pb alone and in combination was established. BFs were collected on days 30, 60, and 90. H&E and qRT-PCR were performed to observe the microstructure and to detect HSP27, HSP40, HSP60, HSP70, and HSP90 mRNA levels, respectively, in BFs. Multivariate correlation analysis and principal component analysis were conducted to explore the correlation among the five HSPs. In our results, Pb caused BF damage and up-regulated the five HSPs at three time points, causing oxidative damage and proteotoxicity via HSP27-HSP40-HSP70-HSP90 pathway. Furthermore, Pb caused time-dependent stress on HSP27, HSP40, HSP60, and HSP70. In addition, Se relieved Pb-caused damage and up-regulation of HSPs. Taken together, we concluded that Se alleviated Pb-caused oxidative injury and proteotoxicity in chicken BFs via the HSP27-HSP40-HSP70-HSP90 pathway.

Stress-induced immunosuppression inhibits immune response to infectious bursal disease virus vaccine partially by miR-27b-3p/SOCS3 regulatory gene network in chicken

Stress-induced immunosuppression (SIIS) is one of the common problems in intensive poultry production, which often reduces the prevention and control effects of various vaccines, including infectious bursal disease virus (IBDV) vaccine, and brings enormous economic losses to the poultry industry. However, the molecular mechanisms of SIIS inhibiting immune response to IBDV vaccine remain unclear. In this study, suppressor of cytokine signaling 3 (SOCS3) gene was selected and stress-induced immunosuppressed chickens were simulated using dexamethasone (Dex). Quantitative real-time PCR (qRT-PCR) was conducted to analyze its expression characteristics and game relationships between SOCS3 gene and miR-27b-3p (it could target SOCS3 gene) in the process of SIIS inhibiting immune response to IBDV vaccine in chicken, and the potential application value of circulating miR-27b-3p as a biomarker was also identified. The results showed that SOCS3 gene and miR-27b-3p were significantly differentially expressed in the candidate tissues during SIIS inhibiting the immune response to IBDV (P < 0.05), respectively, which were key factors involved in the process. Moreover, miR-27b-3p and SOCS3 gene showed game regulation relationships in several tissues during the process, so the miR-27b-3p/SOCS3 regulatory network was one of the key mechanisms of SOCS3 gene participating in the process. Circulating miR-27b-3p was differentially expressed in serum at 10 time points (1, 2, 3, 4, 5, 7, 14, 21, 28, and 35 days postimmunization (dpi)) in the process (P < 0.05), showing that circulating miR-27b-3p was a valid candidate target as a molecular marker for detecting SIIS inhibiting the IBDV immune response. This study can provide references for further studying molecular mechanisms of stress affecting immune response.

A novel composting system for mitigating ammonia emissions and producing nitrogen-rich organic fertilizer

Ammonia emissions not only lead to environmental pollution but also reduce the quality of compost products. Here, a novel composting system (condensation return composting system, CRCS) was designed for mitigating ammonia emissions. The results showed that the CRCS reduced ammonia emissions by 59.3% and increased the total nitrogen content by 19.4% compared with the control. By integrating the results of nitrogen fraction conversion, ammonia-assimilating enzyme activity, and structural equation modeling, it was found that the CRCS facilitated the conversion of ammonia to organic nitrogen by stimulating ammonia-assimilating enzyme activity and ultimately retained nitrogen in the compost product. Moreover, the pot experiment confirmed that nitrogen-rich organic fertilizer produced by the CRCS significantly increased the fresh weight (45.0%), root length (49.2%), and chlorophyll content (11.7%) of pakchoi. This study provides a promising strategy for mitigating ammonia emissions and producing nitrogen-rich organic fertilizer with high agronomic value.

Inhibiting autophagy by miR-19a-3p/PTEN regulation protected retinal pigment epithelial cells from hyperglycemic damage

OBJECTIVE

The catabolic process of autophagy is arousing the attention of researchers studying diabetic retinopathy (DR), but the role and molecular mechanism of autophagy in DR are still unclear.

METHODS

An in vivo diabetic rat model and in vitro hyperglycemic-exposed retinal pigment epithelium (RPE) cell cultures were established to mimic early DR. Transmission electron microscopy and mRFP-GFP-LC3 adenovirus transfection were applied for autophagic flux analysis. MicroRNA (miR)-19a-3p, members of the phosphate and tensin homolog (PTEN)/Akt/mammalian target of rapamycin (mTOR) pathway, and the autophagy-related proteins light chain (LC)3II/I and p62 were detected. Annexin V, transwell, Cell Counting Kit-8, fluorescein isothiocyanate-dextran monolayer permeability assay, and transepithelial electrical resistance were performed to evaluate the effects of regulating autophagy on RPE cells under the DR condition.

RESULTS

Autophagy was aberrantly activated in DR as evidenced by autophagosome accumulation. Further mechanistic experiments revealed that DR induced PTEN expression, thus inhibiting Akt/mTOR phosphorylation and stimulating aberrant autophagy and apoptosis. Notably, these events could be reversed by miR-19a-3p directly targeting PTEN. Downregulation of autophagy by miR-19a-3p overexpression, PTEN knockdown, or 3-methyladenine (3-MA) treatment inhibited autophagosome formation and thus effectively ameliorated hyperglycemia-induced RPE cell apoptosis, increased migration, inhibited viability, and enhanced monolayer permeability under the DR condition.

CONCLUSIONS

Our findings suggest that upregulation of miR-19a-3p inhibits aberrant autophagy by directly targeting PTEN, thus protecting RPE cells against DR damage. miR-19a-3p may represent a novel therapeutic target for inducing protective autophagy in early DR.

Transcriptome analysis of the uterovaginal junction containing sperm storage tubules in heat-stressed breeder hens

Sperm storage tubules (SSTs) in the uterovaginal junction (UVJ) of the oviduct are major sites of sperm storage after artificial insemination or mating. Female birds may regulate sperm motility in the UVJ. Heat stress can decrease the reproductive ability of broiler breeder hens. However, its effects on UVJ remain unclear. Changes in gene expression aid in understanding heat stress-affected molecular mechanisms. Herein, we wanted to conduct a comparative transcriptomic analysis to identify the differentially expressed genes (DEGs) in the UVJ of breeder hens under thermoneutral (23°C) and heat stress (36°C for 6 h) conditions. The results indicated that cloacal temperatures and respiratory rates were significantly increased in heat-stressed breeder hens (P < 0.05). Total RNA was extracted from the hen UVJ tissues containing SSTs after heat exposure. Transcriptome analysis identified 561 DEGs, including 181 upregulated DEGs containing heat shock protein (HSP) transcripts and 380 downregulated DEGs containing immune-related genes, such as interleukin 4-induced 1, radical S-adenosyl methionine domain containing 2, and 2'-5'-oligoadenylate synthetase like, in heat-stressed hens. Gene Ontology analysis revealed the significantly enriched terms involving HSPs. Kyoto Encyclopedia of Genes and Genomes analysis identified 9 significant pathways, including the protein processing in endoplasmic reticulum (11 genes including HSPs), neuroactive ligand-receptor interaction (13 genes including luteinizing hormone/choriogonadotropin receptor), biosynthesis of amino acids (4 genes including tyrosine aminotransferase), ferroptosis (3 genes including heme oxygenase 1), and nitrogen metabolism (carbonic anhydrase [CA]-12 and CA6) pathways. Protein-protein interaction network analysis of DEGs revealed 2 large networks, one containing upregulated HSPs and the other containing downregulated interferon-stimulating genes. Overall, heat stress inhibits innate immunity in the UVJ tissues of broiler chickens, and heat-stressed chickens protect their cells by increasing the expression levels of HSPs. The identified genes are potential candidates for further exploration of the UVJ in heat-stressed hens. The identified molecular pathways and networks increase our understanding of the sperm storage reservoirs (UVJ containing SSTs) within the reproductive tract and may be used to prevent heat stress-induced fertility loss in breeder hens.

Oxidative Stress and Apoptosis in Disk Abalone (Haliotis discus hannai) Caused by Water Temperature and pH Changes

Ocean warming and acidification can induce oxidative stress in marine species, resulting in cellular damage and apoptosis. However, the effects of pH and water temperature conditions on oxidative stress and apoptosis in disk abalone are poorly understood. This study investigated, for the first time, the effects of different water temperatures (15, 20, and 25 °C) and pH levels (7.5 and 8.1) on oxidative stress and apoptosis in disk abalone by estimating levels of H₂O₂, malondialdehyde (MDA), dismutase (SOD), catalase (CAT), and the apoptosis-related gene caspase-3. We also visually confirmed apoptotic effects of different water temperatures and pH levels via in situ hybridization and terminal deoxynucleotidyl transferase dUTP nick end labeling assays. The levels of H₂O₂, MDA, SOD, CAT, and caspase-3 increased under low/high water temperature and/or low pH conditions. Expression of the genes was high under high temperature and low pH conditions. Additionally, the apoptotic rate was high under high temperatures and low pH conditions. These results indicate that changes in water temperature and pH conditions individually and in combination trigger oxidative stress in abalone, which can induce cell death. Specifically, high temperatures induce apoptosis by increasing the expression of the apoptosis-related gene caspase-3.

Nano-selenium protects grass carp hepatocytes against 4-tert-butylphenol-induced mitochondrial apoptosis and necroptosis via suppressing ROS-PARP1 axis

4-tert-butylphenol (4-tBP) is a monomer widely used in the synthesis of industrial chemicals, and posed a high risk to aquatic animals. Our study focused on toxic phenotype and mechanism of detoxification in grass carp hepatocytes (L8824) after 4-tBP-treatment. In this experiment, L8824 displayed hallmark phenotypes of apoptosis and necroptosis after 4-tBP exposure, as evidenced by changes in cell morphology, increased rates of apoptosis and necrosis, the loss of MMP, the accumulation of ROS, and changes in associated factors (PARP1, JNK, Bid, Bcl-2, Bax, AIFM1, CytC, Caspase 9, APAF1, Caspase 3, TNF-α, TNFR1, RIPK1, RIPK3, and MLKL). Furthermore, we found that 4-tBP-induced apoptosis and necroptosis were reversed by pretreating with N-Acetylcysteine (a ROS scavenger) and 3-Aminobenzamide (a PARP1 inhibitor), indicating that 4-tBP induced the onset of mitochondrial apoptosis and necroptosis in L8824 via activating ROS-PARP1 axis. Nano-selenium (Nano-Se) is a novel form of Se with a noteworthy antioxidant capacity. Here, Nano-Se was found to have preventive, therapeutic, and resistance effects on 4-tBP-induced L8824 apoptosis and necroptosis. Nano-Se co-treatment with 4-tBP was an optimal way to alleviate 4-tBP-induced apoptosis and necroptosis. We demonstrated for the first time that Nano-Se protected L8824 against 4-tBP-induced mitochondrial apoptosis and necroptosis through ROS-PARP1 pathway. This study will provide a new theoretical basis for 4-tBP toxicology researches and aquatic animal protection.

Molybdenum fertilizer improved antioxidant capacity of Chinese Merino sheep under compound contamination

To investigate the response of different levels of molybdenum (Mo) fertilizer to Chinese Merino sheep (Junken Type) grazing on natural heavy metal-contaminated meadows, this study was carried out in the Bayanbulak Grassland lying in the northwest of Xinjiang Uygur Autonomous Region, China. A total of 24-hm2 polluted meadows were fenced and were randomly divided into four groups (3 replication/group and 2 hm2/replication) applied 0-kg Mo, 1-kg Mo, 2-kg Mo, and 3-kg Mo (ammonium molybdate tetrahydrate) per hectare for the CON group, group I, group II, and group III, respectively. Seventy-two healthy 1-year-old Chinese Merino sheep (45.56 ± 2.35 kg) were randomly assigned to the tested pastures for 90 days. Compared with the CON group, the Mo content from fertilized groups and the Se content from group II and group III in serums and livers were significantly increased (P < 0.05), and the Cu content from fertilized groups in serums and livers was significantly decreased (P < 0.05). The levels of blood Hb and RBC, and the activities of serum SOD, CAT, GSH-Px, and Cp in group III, were significantly higher (P < 0.05) than those in the CON group, group I, and group II. Serum MDA content in group III was significantly lower (P < 0.05) than that in the other three groups. In summary, Mo fertilization improved the antioxidant capacity of grazing sheep and also reduced the toxic damage to Chinese Merino sheep grazing on natural grasslands contaminated by heavy metals, but Mo poisoning caused by excessive fertilization should be prevented.

Selenium alleviates endoplasmic reticulum calcium depletion-induced endoplasmic reticulum stress and apoptosis in chicken myocardium after mercuric chloride exposure

Mercury is a highly toxic heavy metal with definite cardiotoxic properties and can affect the health of humans and animals through diet. Selenium (Se) is a heart-healthy trace element and dietary Se has the potential to attenuate heavy metal-induced myocardial damage in humans and animals. This study was designed to explore antagonistic effect of Se on the cardiotoxicity of mercuric chloride (HgCl₂) in chickens. Hyline brown hens received a normal diet, a diet containing 250 mg/L HgCl₂, or a diet containing 250 mg/L HgCl₂ and 10 mg/kg Na₂SeO₃ for 7 weeks, respectively. Histopathological observations demonstrated that Se attenuated HgCl₂-induced myocardial injury, which was further confirmed by the results of serum creatine kinase and lactate dehydrogenase levels assay and myocardial tissues oxidative stress indexes assessment. The results showed that Se prevented HgCl₂-induced cytoplasmic calcium ion (Ca²⁺) overload and endoplasmic reticulum (ER) Ca²⁺ depletion mediated by Ca²⁺-regulatory dysfunction of ER. Importantly, ER Ca²⁺ depletion led to unfolded protein response and endoplasmic reticulum stress (ERS), resulting in apoptosis of cardiomyocytes via PERK/ATF4/CHOP pathway. In addition, heat shock protein expression was activated by HgCl₂ through these stress responses, which was reversed by Se. Moreover, Se supplementation partially eliminated the effects of HgCl₂ on the expression of several ER-settled selenoproteins, including selenoprotein K (SELENOK), SELENOM, SELENON, and SELENOS. In conclusion, these results suggested that Se alleviated ER Ca²⁺ depletion and oxidative stress-induced ERS-dependent apoptosis in chicken myocardium after HgCl₂ exposure.

EGCG alleviated Mn exposure-caused carp kidney damage via trpm2-NLRP3-TNF-α-JNK pathway: Oxidative stress, inflammation, and tight junction dysfunction

Manganese (Mn), an essential trace metal element in organisms. However, with extensive use of Mn in industry and agriculture, Mn becomes a heavy metal pollutant in water. (-)-epigallocatechin gallate (EGCG), an tea polyphenols, can alleviate metal toxicity. Kidney is an important detoxifying organ, but toxic mechanism of Mn to kidneys is unclear, which needs further research. Carp is an Asian important economical species for fisheries and a biological model for studying environmental toxicology. Thus, we established excess Mn and EGCG-supplemented carp model to explore molecular mechanism of EGCG alleviating Mn-caused carp kidney damage. In this experiment, we set a control group (the Con group), a Mn treatment group (the Mn group, 90 mg/L Mn), a EGCG supplement group (the EG group, 75 mg/kg EGCG), and a combined group (the Mn + EG group, 90 mg/L Mn and 75 mg/kg EGCG). Transcriptome, qRT-PCR, kit, and morphology method results indicated that excess Mn caused oxidative stress, inflammatory damage, and tight junction dysfunction in carp kidneys. Excess Mn-triggered oxidative stress caused tight junction dysfunction via trpm2-NLRP3-TNF-α-JNK pathway and inflammation. EGCG reversed the harm of Mn to fish through the above mechanism. The findings of this study provided the evidence of EGCG-alleviated Mn poisoning and offered new ideas for reducing heavy metal environmental pollution risk.

Microcystin-LR-induced autophagy regulates oxidative stress, inflammation, and apoptosis in grass carp ovary cells in vitro

MC-LR is one of the cyanotoxins produced by fresh water cyanobacteria. Previous studies showed that autophagy played an important role in MC-LR-induced reproduction toxicity. However, information on the toxicological mechanism is limited. In this study, MC-LR could induce autophagy and apoptosis in GCO cells in vitro. In GCO cells that had been exposed to MC-LR, the inhibitor of 3-MA effectively decreased cell viability and damaged cell ultrastructure. Oxidative stress was significantly increased in the 3-MA + MC-LR group, accompanied by significantly increased MDA content and decreased CAT activity and GST, SOD1, GPx, and GR expression levels (P < 0.05). Inflammation was more serious in the 3-MA + MC-LR group than that of MC-LR group, which was evidenced by increasing expression levels of TNFα, IL11, MyD88, TNFR1, TRAF2, JNK, CCL4, and CCL20 (P < 0.05). Interestingly, the significant decrease of Caspase-9, Caspase-7, and Bax expression and significant increase of Bcl-2 and Bcl-2/Bax ratio in 3-MA + MC-LR group compared to MC-LR group, suggesting that extent of apoptosis were reduced. Taken together, these results indicated that MC-LR induced autophagy and apoptosis in GCO cells, however, the inhibition of autophagy decreased the extent of apoptosis, induced more serious oxidative stress and inflammation, which eventually induced cell death. Our findings provided some information for exploring the toxicity of MC-LR, however, the role of autophagy require further study in vivo.

Mitochondrion Participated in Effect Mechanism of Manganese Poisoning on Heat Shock Protein and Ultrastructure of Testes in Chickens

Manganese (Mn) poisoning can happen in the case of environmental pollution and occupational exposure. However, the underlying mechanisms of Mn-induced teste toxicity and whether mitochondrion and heat shock proteins (HSPs) are involved in toxic effect of Mn on chicken testes remain poorly understood. To investigate this, MnCl₂·4H₂O was administered in the diet (600, 900, and 1800 mg/kg Mn) of chickens for 30, 60, and 90 days. Electron microscopy and qPCR were performed. Results showed that Mn exposure suppressed dose- and time-dependently HSP40 and HSP60 mRNA levels, meanwhile increased does-dependently HSP27, HSP70, and HSP90 mRNA levels at all three time points under three Mn exposure concentrations. Furthermore, Mn treatment damaged myoid cells, spermatocytes, and Sertoli cells through electron microscopic observation, indicating that Mn treatment damaged chicken testes. In addition, abnormal shapes of mitochondria were found, and mitochondria displayed extensive vacuolation. The increase of HSP90 and HSP70 induced by Mn exposure inhibited HSP40 and stimulated HSP27, respectively, in chicken testes, which needs further to be explored. Taken together, our study suggested that there was toxic effect in excess Mn on chickens, and HSPs and mitochondria were involved in the mechanism of dose-dependent injury caused by Mn in chicken testes. This study provided new insights for Mn toxicity identification in animal husbandry production practice.

Effect of Fas and Bcl-2 DNA Damages Response Expression in Stem Cells on Apoptosis of Nucleus Pulposus of Intervertebral Disc

The nucleus pulposus is an elastic jelly composed of crisscross fibrous reticular structures, namely, chondrocytes and proteoglycan mucoid matrix. Embryo and adult SC can resist the accumulation of genetic damage and repair them through various DNA repair mechanisms, thus preventing them from spreading to daughter cells. Fresh medullary tissue was fixed with 10% formaldehyde solution, embedded in paraffin, and sectioned at 4 m. The nucleus pulposus was stained with HE, and its degeneration was observed under light microscope. The average apoptotic index (AI) of 20 denatured nuclei was 50.230, the percentage of Fas-positive cells was 74.255%, and the percentage of Bcl-2-positive cells was 55.370%. The average apoptotic index (AI) was 28.317. The percentage of Fas-positive cells, Fas protein-positive cells, and Bcl-2 protein-positive cells in six normal nuclei was 41.717%, 41.717%, and 27.167%, respectively. The average AI value, Fas protein expression, and Bcl-2 protein expression in the two groups were significantly different (P < 0.05).

Ginsenoside Rh2 inhibits CBP/p300-mediated FOXO3a acetylation and epilepsy-induced oxidative damage via the FOXO3a-KEAP1-NRF2 pathway

Epilepsy is a chronic disease that affects a wide range of people. Furthermore, a third of patients suffering from epileptic seizures do not respond to antiepileptic drugs. In recent years, increasing attention has focused on the role of oxidative stress in acquired epilepsy, and adjuvant antiepileptic drugs to reduce oxidative stress may be a new therapeutic strategy. In this study ginsenoside Rh2 was resistant to oxidative stress induced by epileptic activity in vivo and in vitro. Using online databases, we identified forkhead box O3a (FOXO3a) overexpression in epilepsy tissue and validated this in vitro, in vivo, and in clinical tissues of patients with epilepsy. An in vitro epilepsy model revealed that the overexpression of FOXO3a led to more severe oxidative stress, while the knockdown of FOXO3a had a protective effect on SH-SY5Y cells. Moreover, our results showed that the positive effect of FOXO3a on oxidative stress was caused by the transcriptional activation of Kelch-like ECH-associated protein 1 (KEAP1), a negative regulator of nuclear factor erythroid 2-related factor 2 (NRF2). We also found that ginsenoside Rh2 can directly inhibit the activation of FOXO3a by selectively blocking CREB-binding protein (CBP)/p300-mediated FOXO3a acetylation and play a role in regulating the KEAP1-NRF2 pathway to resist oxidative stress.

A Multiomic Analysis of Chicken Serum Revealed the Modulation of Host Factors Due to Campylobacter jejuni Colonization and In-Water Supplementation of Eugenol Nanoemulsion

Campylobacter jejuni is a foodborne pathogen that causes campylobacteriosis globally, affecting ~95 million people worldwide. Most C. jejuni infections involve consuming and/or handling improperly cooked poultry meat. To better understand chicken host factors modulated by Campylobacter colonization, we explored a novel LCMS-based multiomic technology using three experimental groups: (1) negative control, (2) positive control, and (3) eugenol nanoemulsion (EGNE) treatment (supplemented with 0.125% EGNE in the water) of broiler chickens (n = 10 birds/group). Birds in groups two and three were challenged with C. jejuni on day 7, and serum samples were collected from all groups on day 14. Using this multiomic analysis, we identified 1216 analytes (275 compounds, seven inorganics, 407 lipids, and 527 proteins). The colonization of C. jejuni significantly upregulated CREG1, creatinine, and 3-[2-(3-Hydroxyphenyl) ethyl]-5-methoxyphenol and downregulated sphingosine, SP d18:1, high mobility group protein B3, phosphatidylcholines (PC) P-20:0_16:0, PC 11:0_26:1, and PC 13:0_26:2. We found that 5-hydroxyindole-3-acetic acid significantly increased with the EGNE treatment when compared to the positive and negative controls. Additionally, the treatment increased several metabolites when compared to the negative controls. In conclusion, this study revealed several potential targets to control Campylobacter in broiler chickens.

Oxidative stress mediated immunosuppression caused by ammonia gas via antioxidant/oxidant imbalance in broilers

1. Ammonia is one of major air pollutants in intensive poultry houses, where it causes immunosuppression in broilers. Although previous studies have focused on a particular organ, data on multiple organs have not been reported.2. In the following work, broilers were exposed to environmental ammonia (0, 10, 20, and 40 mg/m³ from 1-21 d old; and 0, 15, 30, and 60 mg/m³ from 22-42 d old).3. Ammonia exposure reduced bird spleen index at 42 d and thymus index at 14, 28, 35 and 42 d, meaning that ammonia caused immunosuppression in birds. Moreover, high ammonia exposure down-regulated the expression of toll-like receptor 4 (TLR4) in lung tissue at 21 d, as well as TLR4 in lung and tracheal mucosa at 42 d when analysed using qRT-PCR. It increased SIgA in saliva at 42 d when analysed by ELISA. Ammonia increased interleukin-6 (IL-6), IL-1β, interferon-α (IFN-α), and IFN-γ in serum at 28 d from the ELISA assay, which indicated that all of these factors took part in ammonia-immunosuppression in birds.4. Three antioxidants (CAT, SOD, T-AOC) decreased, and one oxidant MDA increased after ammonia exposure in the liver and blood, which indicated that ammonia caused oxidative stress via the imbalance of antioxidants/oxidants in birds.5. Correlation analysis showed that TLR4 and TLR15 in the tracheal mucosa were significantly positively related to IFN-γ and negatively related to IL-6. TLR2 in the lung was significantly positively related to IL-1β, and TLR2 in bird tracheal mucosa was negatively related to IL-6 in serum.6. The results suggested that oxidative stress mediated immunosuppression caused by ammonia gas via antioxidant/oxidant imbalance in broilers.

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

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

The toxicity of 4-tert-butylphenol in early development of zebrafish: morphological abnormality, cardiotoxicity, and hypopigmentation

Endocrine disrupting effects of 4-tert-butylphenol (4-t-BP) are well described in literature. However, the evidence regarding developmental toxic effect of 4-t-BP is still vague. The present study used zebrafish as a model organism to investigate the toxic effect of 4-t-BP. The results showed that 4-t-BP exposure at 3, 6, and 12 μM induced developmental toxicity in zebrafish, such as reduced embryo hatchability and abnormality morphological. Flow cytometry analysis showed that 4-t-BP also induced intracellular ROS production. 4-t-BP induced changes in the expression of genes related to cardiac development and melanin synthesis, resulting in cardiotoxicity and hypopigmentation. 4-t-BP also caused oxidative stress, and initiated apoptosis through p53-bcl-2/bax-capase3 pathway. Integrative biomarker response analysis showed time- and dose-dependent effects of 4-t-BP on oxidative damage and developmental toxicity in zebrafish embryos. Overall, this study contributed to a comprehensive evaluation of the toxicity of 4-t-BP, and the findings provided new evidence for early warning of residues in aquatic environments.

Untargeted Metabolomics Revealed Potential Biomarkers of Small Yellow Follicles of Chickens during Sexual Maturation

Sexual maturation provides economically important traits in poultry production. Research on the initiation mechanism of sexual maturity is of great significance for breeding high-yield laying hens. However, the underlying mechanisms are not fully clear. Here, one hundred and fifty Chahua No. 2 laying hens (the CH2 group, which has precocious puberty) and one hundred and fifty Wu Liang Shan black-bone laying hens (the WLS group, a late-maturing chicken breed) with similar weights and ages were randomly selected. ELISA was used to determine the secretion levels of luteinizing hormone (LH), estradiol (E2), and progesterone (P4) in 150-day-old serum and small yellow follicle (SYF) tissues. A histology examination, immunohistochemistry, and quantitative real-time PCR (qPCR) were used to explore the molecular mechanism of how some genes related to oxidative stress affect sexual maturation. The results showed that the secretion levels of LH, E2, and P4 in the CH2 group serum and SYF were higher than those in the WLS group. The results of the real-time PCR of all genes showed that the expression levels of cytochrome P450 family 11 subfamily A member 1, steroidogenic acute regulatory protein, follicle-stimulating hormone receptor, and cytochrome P450 family 19 subfamily A member 1 in the CH2 group were significantly higher than those in the WLS groups (p < 0.001). Untargeted metabolomics combined with multivariate statistical analysis was used to identify biomarkers of SYF tissues in the CH2 and WLS groups. A trajectory analysis of the principal component analysis (PCA) results showed that the samples within the group were clustered and that the samples were dispersed between the CH2 and the WLS groups, indicating that the results of the measured data were reliable and could be used for further research. Further analysis showed that a total of 319 metabolites in small yellow follicles of the CH2 and WLS groups were identified, among which 54 downregulated differential metabolites were identified. These 54 metabolites were found as potential CH2 biomarkers compared with WLS at 150 days, and the different expressions of L-arginine, L-prolinamide, (R)-4-hydroxymandelate, glutathione, and homovanillic acid were more significant. Twenty metabolic pathways were found when significantly differential metabolites were queried in the KEGG database. According to the impact values of the metabolic pathways, eighteen differential metabolites belonged to the mTOR signaling pathway, glutathione metabolism, ABC transporters, the cell ferroptosis pathway, and D-arginine and D-ornithine metabolism. Interestingly, we identified that the cell ferroptosis pathway played an important role in chicken follicle selection for the first time. The histology and immunohistochemistry of SYF showed that the number of granulosa cells increased in the CH2 groups and the expression levels of glutathione peroxidase 4, tumor protein p53, ribosomal protein S6 kinase, and sterol regulatory element binding protein 1 in the granulosa cell layer were upregulated in the CH2 group at the time of sexual maturation. Furthermore, we also speculated that the antioxidant system may play an indispensable role in regulating sexual maturity in chickens. Overall, our findings suggest differentially expressed metabolites and metabolic pathways between CH2 and WLS chickens, providing new insights into the initiation mechanism of sexual maturation.

Honokiol reduces cadmium-induced oxidative injury and endosomal/lysosomal vacuolation via protecting mitochondrial function in quail (Coturnix japonica) liver tissues

Cadmium (Cd) pollution in environment is toxic to birds. This study aimed to assess antagonistic effect of honokiol (HNK) on Cd-induced quail (Coturnix japonica) liver tissue damage and Cd-induced vacuolation in hepatocytes. We found that HNK alleviated Cd-induced liver pathological damage marked by elevated serum liver biochemical indicators, disordered antioxidant levels and trace elements in quails. HNK reduced Cd-induced liver cell apoptosis as assessed by western blotting and TUNEL staining. The ultrastructure of hepatocytes under transmission electron microscope revealed that Cd induced mitochondrial damage in addition to abnormal enlargement and increased vacuolar structure of cells. Mitochondrial damage and vacuolization were reduced in the HNK + Cd group. Cd induced an increase in the levels of endosomal/lysosomal-related genes, while HNK treatment reversed this effect. Finally, we demonstrated that vacuolation in buffalo rat liver 3A (BRL 3A) cells occurred primarily due to Cd-induced oxidative stress damage that reduces mitochondrial ATP content and indirectly led to dysfunction of ATP-dependent lipid kinase PIKfyve complex. In summary, we are the first to report that Cd induces abnormal enlargement of endosome/lysosomes in quail liver cells and HNK alleviated this phenomenon by reducing mitochondrial damage and increasing intracellular ATP level. This study demonstrated the toxic effect of Cd pollution on birds and how HNK mitigated these effect at the cellular level. Overall, more research on Cd pollution and HNK use in animal husbandry is warranted.

Individual PM2.5 component exposure model, elevated blood pressure and hypertension in middle-aged and older adults: A nationwide cohort study from 125 cities in China

Recently, elevated blood pressure (BP) and hypertension (HTN) have caused a huge burden of health loss. Previous studies used ambient air pollutants as a proxy for individual exposure, limiting the assessment of its multiple exposure to health effects. For the first time, this study constructed individual PM_2.5 component (SO₄^2-, NO₃^-, NH₄⁺, OM, and BC) exposure model DAG (Directed Acyclic Graph), DAG-oriented generalized linear model and random forest model, and explored the effects of single and multiple exposures to PM_2.5 components on BP at different stages by the generalized linear model (GLM) and Quantile g-Computation (QgC) model based on a large cohort study in China. We defined BP in four stages according to the 2017 ACC/AHA guidelines. After excluding the lack of key information, the cohort analyses ultimately included 9031 participants. Our results showed that the individual PM_2.5 component exposure model had good efficacy. Single or multiple exposure to PM_2.5 components had significant positive effects on normal BP to elevated BP and elevated BP to stage 1 HTN. In addition, males, the elderly and urban residents were more sensitive to PM_2.5 components. This study provided implications for environmental exposure assessment and control of particulate pollution in the future.

Toxicity of tributyltin chloride on haarder (Liza haematocheila) after its acute exposure: Bioaccumulation, antioxidant defense, histological, and transcriptional analyses

Liza haematocheila is exposed to various chemical contaminants from anthropogenic sources, including tributyltin chloride (TBTC). Yet the toxicity mechanism of TBTC on haarder remains unclear. The haarder was exposed to different doses (0, 10%, 20%, and 50% of LC₅₀-96 h) of TBTC. In this study, the results revealed its high bioaccumulation in the livers and significant alteration for development. The activities of antioxidant enzymes superoxide dismutase, catalase, and glutathione peroxidase decreased after 96-h exposure to TBTC, this accompanied by an increased malondialdehyde level. TBTC exposure caused the intense production of reactive oxygen species, a reduction in total blood cell count in serum, and apoptosis-related alterations in livers, indicating that enhanced oxidative stress occurred in the process of TBTC exposure. Histological results revealed angiorrhexis and infiltration of inflammatory cells, vacuolar degeneration of hepatocytes in the livers, and swelling, fusion, and disintegration of gill organs. Interestingly, the obtained transcriptional profiles indicated that high doses of TBTC caused energy disorder, apoptosis, and adipogenesis restriction mediated by cytokines and adipokines in Jak-STAT and adipocytokine signaling pathways. In summary, acute exposure to high doses of TBTC could impair the antioxidant system and pathways related to energy, apoptosis and adipogenesis, eventually posing a serious challenge to the fitness of haarder individuals and its fish populations as marine resources.

Dietary rosemary extract modulated gut microbiota and influenced the growth, meat quality, serum biochemistry, antioxidant, and immune capacities of broilers

After the legislative ban on the utilization of antibiotics in animal feed, phytochemical substances gained increasing attention as alternatives to antibiotics because of their bioactivities and safety for animals. The present study aimed to investigate the influence of dietary rosemary extract (RE) on growth performance, meat quality, serum biochemistry, antioxidant and immune capacities, and gut microbiota composition of broilers. By exploring connections among RE, physiological characteristics of broilers, and key microbiota, we sought to provide evidence for the utilization of RE in poultry feed. A total of 280 1-d-old female AA broilers were randomly separated into five groups, and were fed a basal diet supplemented with 0, 250, 500, 750, and 1,000 mg/kg of RE, respectively. Results showed that with regard to growth performance, both 500 and 750 mg/kg RE reduced the broiler feed-to-gain ratio from 1 to 21 d (P = 0.018). Regarding meat quality, all compositions of dietary RE reduced cooking loss of breast muscle (P < 0.01), and 500 and 1,000 mg/kg RE reduced the cooking loss of thigh muscle (P = 0.045). Regarding serum biochemical indexes, 500 mg/kg RE reduced ALB, TCHO, HDL-C, and LDL-C, and 750 mg/kg RE reduced GLU, TP, ALB, UA, TG, TCHO, HDL-C, and LDL-C (P < 0.01). Regarding antioxidant and immune capacities, 250, 500, 750, and 1,000 mg/kg RE increased T-AOC, GSH-Px, SOD, CAT, IL-2, IgA, IgG, and IgM levels (P < 0.01), and decreased serum MDA level (P < 0.01). RE at 750 mg/kg showed similar effects on growth performance, meat quality, and antioxidative and immune capacities, but a better influence on serum biochemical indexes of broilers compared with 500 mg/kg. Further analysis was conducted to investigate the effect of 750 mg/kg dietary RE on the gut microbial composition of broilers, and the results showed that 750 mg/kg RE reduced the relative abundance of g_Lachnoclostridium, g_Escherichia_Shigella, and g_Marvinbryantia (P <0.05, LDA score >2), which were negatively correlated to antioxidative and immune-associated parameters (P < 0.05). In conclusion, 750 mg/kg dietary RE was shown to have certain beneficial effects on growth performance and meat quality, and hypolipidemic and hypoglycemic effects on broilers. Furthermore, dietary RE improved antioxidant and immune capacities, which was partially attributed to the reduced abundance of certain pathogenic bacteria in broilers.

Identification of a necroptosis-related prognostic gene signature associated with tumor immune microenvironment in cervical carcinoma and experimental verification

Cervical carcinoma (CC) has been associated with high morbidity, poor prognosis, and high intratumor heterogeneity. Necroptosis is the significant cellular signal pathway in tumors which may overcome tumor cells’ apoptosis resistance. To investigate the relationship between CC and necroptosis, we established a prognostic model based on necroptosis-related genes for predicting the overall survival (OS) of CC patients. The gene expression data and clinical information of cervical squamous cell carcinoma and endocervical adenocarcinoma (CESC) patients were obtained from The Cancer Genome Atlas (TCGA). We identified 43 differentially expressed necroptosis-related genes (NRGs) in CESC by examining differential gene expression between CESC tumors and normal tissues, and 159 NRGs from the Kyoto Encyclopedia of Genes and Genomes (KEGG) database. Gene ontology (GO) and KEGG enrichment analysis illustrated that the genes identified were mainly related to cell necrosis, extrinsic apoptosis, Influenza A, I − kappaB kinase/NF − kappaB, NOD − like receptor, and other signaling pathways. Subsequently, least absolute shrinkage and selection operator (LASSO) regression and univariate and multivariate Cox regression analyses were used to screen for NRGs that were correlated with patient prognosis. A prognostic signature that includes CAMK2A, CYBB, IL1A, IL1B, SLC25A5, and TICAM2 was established. Based on the prognostic model, patients were stratified into either the high-risk or low-risk subgroups with distinct survival. Receiver operating characteristic (ROC) curve analysis was used to identify the predictive accuracy of the model. In relation to different clinical variables, stratification analyses were performed to demonstrate the associations between the expression levels of the six identified NRGs and the clinical variables in CESC. Immunohistochemical (IHC) validation experiments explored abnormal expressions of these six NRGs in CESC. We also explored the relationship between risk score of this necroptosis signature and expression levels of some driver genes in TCGA CESC database and Gene Expression Omnibus (GEO) datasets. Significant relationships between the six prognostic NRGs and immune-cell infiltration, chemokines, tumor mutation burden (TMB), microsatellite instability (MSI), and immune checkpoints in CESC were discovered. In conclusion, we successfully constructed and validated a novel NRG signature for predicting the prognosis of CC patients and might also play a crucial role in the progression and immune microenvironment in CC.

4-tert-butylphenol triggers common carp hepatocytes ferroptosis via oxidative stress, iron overload, SLC7A11/GSH/GPX4 axis, and ATF4/HSPA5/GPX4 axis

4-tert-butylphenol (4-tBP) is a toxic environmental pollutant with moderate bioaccumulation, environmental persistence, and long-term toxicity. Its toxicity to aquatic organisms has become an issue of concern. However, the molecular mechanism of 4-tBP toxicity to aquatic organisms remained unclear. Liver is a target organ for environmental pollutants. Here, we established 4-tBP-exposed toxicity model in vivo and primary hepatocyte model in vitro in common carp (Cyprinus carpio L.). We found increased hepatic-somatic index (HSI) and abnormal serum biochemical indexes (ALT, AST, and LDH) after 4-tBP exposure, indicating liver damage. We further revealed that 4-tBP damaged the structural integrity of the livers with typical features of ferroptosis. Based on toxicogenomics analysis, we found ferroptosis is likely to be involved in the mechanism of 4-tBP-induced liver damage. Moreover, our in vivo and in vitro experiment provided evidences that 4-tBP-exposure led to excess oxidative stress, iron overload, decreased MMP, and abnormal expression of ferroptosis-related factors. Interestingly, ferrostatin-1 (Fer-1, a ferroptosis inhibitor) pretreatment alleviated above changes. In summary, we demonstrated that 4-tBP triggered hepatocytes ferroptosis via oxidative stress, iron overload, SLC7A11/GSH/GPX4 axis, and ATF4/HSPA5/GPX4 axis. For the first time, we discovered that Fer-1 can ameliorate the toxicity of 4-tBP, which needs more investigations. Our results provided a scientific basis of molecular mechanism of 4-tBP-induced fish poisoning.

Ethyl Acetate Fraction of Hedyotis diffusa Willd Induces Apoptosis via JNK/Nur77 Pathway in Hepatocellular Carcinoma Cells

Background

Hepatocellular carcinoma (HCC) is characterized by poor diagnosis and high mortality. Novel and efficient therapeutic agents are urgently needed for the treatment. Hedyotis diffusa Willd (HDW) is used to treat cancers, especially HCC in China.

Purpose

The study aimed to identify the main anti-HCC extract in HDW and to explore the mechanism of the active extract.

Materials and Methods

The high-performance liquid chromatography-quadrupole-time of flight mass spectrometry (HPLC-QTOF-MS) method was used for the simultaneous determination of main compounds in the ethyl acetate fraction of HDW (EHDW). The toxicity test of different HDW fractions was carried out on larvae at 2 day-post-fertilization (dpf) for 72 h. The in vivo anti-HCC effect of different HDW fractions was evaluated on a zebrafish tumor model by immersion administration. The antiproliferative effect of HDW fractions was determined with MTT assay, as well as hematoxylin and eosin (HE) staining assay. Hoechst 33258 staining was used to observe changes in nucleus morphology. Flow cytometry analysis was used to investigate apoptosis induction. Western blot analysis was used to examine apoptosis-related proteins, and key proteins in JNK/Nur77 signaling pathway. SP600125 was served to validate the apoptotic mechanism.

Results

EHDW showed the strongest tumor cell growth inhibitory effect on zebrafish tumor model. Further study revealed that EHDW induced apoptosis in zebrafish tumor model and in cultured Hep3B cells. Meanwhile, it has been shown that the levels of BCL2-associated X (Bax), cytochrome c (cyto c), cleaved-caspase 3, and poly-ADP-ribose polymerase (PARP) cells were upregulated. In contrast, the level of antiapoptotic B cell lymphoma-2 (Bcl-2) was downregulated in Hep3B cells. Additionally, EHDW activated JNK/Nur77 pathway by increasing the levels of p-JNK(Thr183/Tyr185) and p-Nur77(Ser351). Further study showed that blockage of JNK by SP600125 reversed EHDW-induced JNK/Nur77 pathway and the downstream apoptotic proteins.

Conclusion

In conclusion, EHDW exerted the anti-HCC effect, which may be attributed to the activation of JNK/Nur77 pathway. This study supported the rationale of HDW as an HCC therapeutic agent.

Immunosuppression participated in complement activation-mediated inflammatory injury caused by 4-octylphenol via TLR7/IκBα/NF-κB pathway in common carp (Cyprinus carpio) gills

4-octylphenol (4-OP), a toxic estrogenic environmental pollutant, can threaten aquatic animal and human health. However, toxic effect of 4-OP on fish has not been reported. To investigate molecular mechanism of gill poisoning caused by 4-OP exposure, a carp 4-OP poisoning model was established, and then blood and gills were collected on day 60. The results demonstrated that gill was a target organ attacked by 4-OP, and exposure to 4-OP caused carp gill inflammatory injury. There were 1605 differentially expressed genes (DEGs, including 898 up-regulated DEGs and 707 down-regulated DEGs). KEGG and GO were used to further analyze obtained 1605 DEGs, indicating that complement activation, immune response, and inflammatory response participated in the mechanism of 4-OP-caused carp gill inflammatory injury. Our data at transcription level further revealed that 4-OP caused complement activation through triggering complement component 3a/complement component 3a receptor (C3a/C3aR) axis and complement component 5a/complement component 5a receptor 1 (C5a/C5aR1) axis, induced immunosuppression through the imbalances of T helper (Th) 1/Th2 cells and regulatory T (Treg)/Th17 cells, as well as caused inflammatory injury via toll like receptor 7/inhibitor kappa B alpha/nuclear factor-kappa B (TLR7/IκBα/NF-κB) pathway. Taken together, immunosuppression participated in complement activation-mediated inflammatory damage in carp gills after 4-OP treatment. The findings of this study will provide pioneering information and theoretical support for the mechanism of 4-OP poisoning, and will provide reference for the assessment of estrogenic environmental pollution risk.

Florfenicol induced renal inflammatory response and apoptosis via cell adhesion molecules signaling pathway

Early use of florfenicol (FFC) can adversely affect the health of broilers. Our previous studies showed that FFC caused kidney injury in broilers. However, the mechanism by which FFC causes nephrotoxicity remains unclear. In order to further explore the regulatory effect of FFC on specific signal pathway in the injured kidneys and the interaction between genes and proteins in this signal pathway, the transcriptome and proteome sequencing were performed on the chick kidneys in the control group and the FFC treatment group. Then, the sequencing data were analyzed, and the screened genes and proteins were verified by real-time quantitative PCR (qPCR) and parallel reaction monitoring (PRM), respectively. The results of sequencing showed that FFC exposure altered significantly the expression levels of 657 genes and 477 proteins in chick kidneys. Among them, 9 significantly differentially expressed genes (including CD28, ICOS, BLB1, BLB2, DMB2, CLDN8, CLDN18, CLDN19, and NEGR1) and 3 significantly differentially expressed proteins (including CD28, ICOS, and CLDN8) were involved in the cell adhesion molecules signaling pathway. Further analysis found that, the changes of the above genes and proteins were related to inflammation and apoptosis of the tissues and histiocytes in chick kidneys. Therefore, the structure and morphology of renal tissues, the expression levels of inflammatory and apoptotic factors, and the apoptotic rate of renal histocytes were detected. It was found that compared with the control group, there was obvious inflammatory cell infiltration in renal tissues of the FFC treatment group. At the same time, the levels of pro-inflammatory factors and pro-apoptotic factors raised significantly, and the apoptotic rate of renal histocytes increased significantly. The above results confirmed that FFC induced inflammatory reaction and apoptosis in chick kidneys by activating the cell adhesion molecules signaling pathway.

The Effect of Dietary Saccharomyces cerevisiae on Growth Performance, Oxidative Status, and Immune Response of Sea Bream (Sparus aurata)

The objective of this study was to evaluate the beneficial effect of Saccharomyces cerevisiae (SC) on growth, intestinal morphometric characteristics, blood indices, redox balance, expression of immune-related genes, and their involvement in disease resistance in sea bream (Sparus aurata). Three hundred healthy sea bream fingerlings were allocated into equal four groups (15 fish per hapa). The first group was served as a control and received a basal diet, while the other three groups were fed diets containing 1, 2, and 4 g/kg diet SC, respectively. At the end of week 16, the daily weight gain, specific growth rate, and feed utilization were significantly higher in the SC2 and SC4 groups than the control (p < 0.05). SC dose-dependently improved intestinal morphology, and the 4 g/kg diet significantly increased dry matter, crude fat, and crude protein percentage of body composition when compared with the control group. The 4 g/kg SC boosted innate immune response and phagocytic activity, and all SC-supplemented diets improved total protein, glucose, triglycerides, and urea concentrations, as well as intestinal digestive enzymatic activities. All estimated oxidative markers were significantly enhanced in the group that received 4 g/kg SC when compared with the control and other SC groups (p < 0.05). Feeding the fish a diet supplemented with 4 g/kg SC markedly regulated the expression of HSP70, IGF1, and IL-1β genes. In addition, the 4 g/kg SC-supplemented diet was the most effective in protecting the fish against Vibrio parahaemolyticus challenge. In conclusion, SC-enriched diet improved growth performance, intestinal morphology, redox homeostasis, and immune response of S. aurata with the 4 g/kg concentration as the most effective.

Hydrogen sulfide-induced oxidative stress mediated apoptosis via mitochondria pathway in embryo-larval stages of zebrafish

Hydrogen sulfide (H₂S), a highly toxic gas, has become a polluting gas that cannot be ignored, while H₂S exposure results in acute or chronic poisoning or even death in humans or animals and plants, but the relevant mechanisms remain poorly understood. In this study, 9-day-old zebrafish larvae were exposed continuously to culture medium containing 30 μM survival rate was counted on H₂S, and our results indicated that H₂S exposure increased intracellular ROS, Ca²⁺, NO and MDA contents and decreased SOD activity, meaning that H₂S caused oxidative stress in embryo-larval stages of zebrafish. Furthermore, we found that transgenic zebrafish (cms Tg/+ AB) displayed a lower fluorescence intensity, and cytochrome c oxidase (COX) activity and JC-1 monomer fluorescence ratio increased under H₂S treatment conditions. These findings indicated that H₂S caused mitochondrial dysfunction. Moreover, in this experiment, after H₂S treatment, the increase of apoptotic cells, activity of caspase 3 and transcription of typical apoptosis-associated genes including BCL2 associated agonist of cell death (Bad), and BCL2 associated X apoptosis (Baxa) and so on were found, which suggested that H₂S caused apoptosis in zebrafish larvae. Therefore, our data meant that H₂S-traggered oxidative stress mediate mitochondrial dysfunction, thus triggering apoptosis. In conclusion, oxidative stress triggered H₂S-induced apoptosis via mitochondria pathway in embryo-larval stages of zebrafish.

Genome-wide identification of chicken bursae of Fabricius miRNAs in response to very virulent infectious bursal disease virus

Infectious bursal disease virus (IBDV) can cause a highly contagious immunosuppressive disease in young chickens. MicroRNAs (miRNAs) are crucial regulators of gene expression and are involved in the pathogenesis of IBDV infection. To investigate the roles of miRNA in chicken bursae of Fabricius in response to very virulent IBDV (vvIBDV) infection, RNA sequencing was performed to compare the small RNA libraries from uninfected and vvIBDV-infected group which was infected for 3 days. A total of 77 differentially expressed (DE) miRNAs were identified in BF, of which 42 DE miRNAs were upregulated and 35 DE miRNAs were downregulated. A gene ontology analysis showed that genes associated with cellular processes, cells, and binding were enriched. Moreover, pathway analyses suggested that apoptosis, T cell receptor signaling pathways, and chemokine signaling pathways may be activated following vvIBDV infection. In addition, we predicted the target genes of DE miRNAs and constructed an miRNA-mRNA regulatory network. In total, 189 pairs of miRNA-target genes were identified, comprising 67 DE miRNAs and 73 mRNAs. In this network, gga-miR-1684b-3p was identified with the highest fold change, as well as gga-miR-1788-3p and gga-miR-3530-5p showed a high degree of change. The above three miRNAs were considered to play vital roles in vvIBDV-host interactions. This study was the first to perform a comprehensive analysis of DE miRNAs in the bursa of Fabricius in response to vvIBDV infection, and it provided new insights into molecular mechanisms underlying vvIBDV infection and pathogenesis.

Salvia miltiorrhiza polysaccharides alleviates florfenicol-induced liver metabolic disorder in chicks by regulating drug and amino acid metabolic signaling pathways

Excessive and nonstandard use of florfenicol (FFC) can damage animal body, pollute ecological environment, and even harm human health. The toxic and side effects of FFC directly affect the production performance of poultry and the safe supply of chicken-related food. Salvia miltiorrhaza polysaccharides (SMPs) are natural macromolecular compounds, and were proved to have the effect of protecting animal liver. We used transcriptome and proteome sequencing technologies to study the effect of FFC on specific signal transduction pathways in chick livers and further explored the regulatory effect of SMPs on the above same signal pathways, and finally revealed the intervention effect and mechanism of SMPs on FFC-induced changes of liver function. The screened sequencing results were verified by qPCR and PRM methods. The results showed that FFC changed significantly 9 genes and 5 proteins in drug metabolism-cytochrome P450 signaling pathway, and the intervention of SMPs adjusted the expression levels of 5 genes and 4 proteins of the above factors. In glycine, serine and threonine metabolism signaling pathway, 8 genes and 8 proteins were significantly changed due to FFC exposure, and SMPs corrected the expression levels of 5 genes and 6 proteins to a certain extent. In conclusion, SMPs alleviated FFC-induced liver metabolic disorder in chicks by regulating the drug and amino acid metabolism pathway. This study is of great significance for promoting the healthy breeding of broilers and ensuring the safe supply of chicken-related products.

MicroRNAs: Potential mediators between particulate matter 2.5 and Th17/Treg immune disorder in primary membranous nephropathy

Primary membranous nephropathy (PMN), is an autoimmune glomerular disease and the main reason of nephrotic syndrome in adults. Studies have confirmed that the incidence of PMN increases yearly and is related to fine air pollutants particulate matter 2.5 (PM2.5) exposure. These imply that PM2.5 may be associated with exposure to PMN-specific autoantigens, such as the M-type receptor for secretory phospholipase A2 (PLA2R1). Emerging evidence indicates that Th17/Treg turns to imbalance under PM2.5 exposure, but the molecular mechanism of this process in PMN has not been elucidated. As an important indicator of immune activity in multiple diseases, Th17/Treg immune balance is sensitive to antigens and cellular microenvironment changes. These immune pathways play an essential role in the disease progression of PMN. Also, microRNAs (miRNAs) are susceptible to external environmental stimulation and play link role between the environment and immunity. The contribution of PM2.5 to PMN may induce Th17/Treg imbalance through miRNAs and then produce epigenetic affection. We summarize the pathways by which PM2.5 interferes with Th17/Treg immune balance and attempt to explore the intermediary roles of miRNAs, with a particular focus on the changes in PMN. Meanwhile, the mechanism of PM2.5 promoting PLA2R1 exposure is discussed. This review aims to clarify the potential mechanism of PM2.5 on the pathogenesis and progression of PMN and provide new insights for the prevention and treatment of the disease.