Involvement of mitochondrial pathway in environmental metal pollutant lead-induced apoptosis of chicken liver: perspectives from oxidative stress and energy metabolism

Rat Hepatocytes Protect against Lead-Cadmium-Triggered Apoptosis Based on Autophagy Activation

Lead and cadmium are foodborne contaminants that threaten human and animal health. It is well known that lead and cadmium produce hepatotoxicity; however, defense mechanisms against the co-toxic effects of lead and cadmium remain unknown. We investigated the mechanism of autophagy (defense mechanism) against the co-induced toxicity of lead and cadmium in rat hepatocytes (BRL-3A cells). Cultured rat liver BRL-3A cell lines were co-cultured with 10, 20, 40 μM lead and 2.5, 5, 10 μM cadmium alone and in co-culture for 12 h and exposed to 5 mM 3-Methyladenine (3-MA), 10 μM rapamycin (Rapa), and 50 nM Beclin1 siRNA to induce cellular autophagy. Our results show that treatment of BRL-3A cells with lead and cadmium significantly decreased the cell viability, increased intracellular reactive oxygen species levels, decreased mitochondrial membrane potential levels, and induced apoptosis, which are factors leading to liver injury, and cell damage was exacerbated by co-exposure to lead-cadmium. In addition, the results showed that lead and cadmium co-treatment induced autophagy. We further observed that the suppression of autophagy with 3-MA or Beclin1 siRNA promoted lead-cadmium-induced apoptosis, whereas enhancement of autophagy with Rapa suppressed lead-cadmium-induced apoptosis. These results demonstrated that co-treatment with lead and cadmium induces apoptosis in BRL-3A cells. Interestingly, the activation of autophagy provides cells with a self-protective mechanism against induced apoptosis. This study provides insights into the role of autophagy in lead-cadmium-induced apoptosis, which may be beneficial for the treatment of lead-cadmium-induced liver injury.

Lead induces mouse skin fibroblast apoptosis by disrupting intracellular homeostasis

Lead (Pb) is a critical industrial and environmental contaminant that can cause pathophysiological changes in several cellular and organ systems and their processes, including cell proliferation, differentiation, apoptosis, and survival. The skin is readily exposed to and damaged by Pb, but the mechanisms through which Pb damages cells are not fully understood. We examined the apoptotic properties of Pb in mouse skin fibroblast (MSF) in vitro. Treatment of fibroblasts with 40, 80, and 160 μM Pb for 24 h revealed morphological alterations, DNA damage, enhanced caspase-3, -8, and -9 activities, and apoptotic cell population. Furthermore, apoptosis was dosage (0-160 μM) and time (12-48 h) dependent. Concentrations of intracellular calcium (Ca²⁺) and reactive oxygen species were increased, and the mitochondrial membrane potential was decreased in exposed cells. Cell cycle arrest was evident at the G0/G1 phase. The Bax, Fas, caspase-3 and -8, and p53 transcript levels were increased, whereas Bcl-2 gene expression was decreased. Based on our analysis, Pb triggers MSF apoptosis bydisrupting intracellular homeostasis. Our findings enrich the knowledge about the mechanistic function of Pb-induced cytotoxicity on human skin fibroblasts and could potentially guide future Pb health risk assessments.

Protective effects of sinomenine hydrochloride on lead-induced oxidative stress, inflammation, and apoptosis in mouse liver

Lead, one of the most common heavy metal toxins, seriously affects the health of humans and animals. Sinomenine hydrochloride (SH) shows antioxidative, anti-inflammatory, antiviral, and anticancer properties. Hence, this study investigated the protective effects of SH against Pb-induced liver injury and explored the underlying mechanisms. First, a mouse model of lead acetate (0.5 g/L lead acetate in water, 8 weeks) was established, and SH (100 mg/kg bw in water, 8 weeks) intervention was administered by gavage. Then, the protective effect of SH against lead-induced liver injury was evaluated through serum biochemical analysis, histopathological analysis, and determination of malondialdehyde (MDA) and total antioxidant capacity (T-AOC) levels. The messenger RNA (mRNA) expression levels of the cytokines IL-1β and TNF-α and the apoptosis factors Bax, Bcl-2, and Caspase3 in the liver were detected by quantitative real-time PCR. Then, the expression levels of IL-1β and TNF-α in the liver were detected by ELISA. Immunohistochemical determination of the expression of the apoptosis factors Bax, Bcl-2, and Caspase3 was performed. SH treatment reduced the levels of liver alanine aminotransferase, aspartate aminotransferase (AST), lactate dehydrogenase (LDH), and MDA in Pb-treated mice, indicating that SH protected the liver from injury and oxidative stress in Pb-treated mice. SH also increased the liver T-AOC of Pb-treated mice. Quantitative real-time PCR, ELISA, and immunohistochemical analysis showed that SH inhibited apoptosis, as indicated by the regulation of the mRNA expression of Bax and Bcl-2 and the reduced expression of Caspase3 and pro-inflammatory factors (IL-1β and TNF-α) in the livers of Pb-treated mice. These results suggest that SH protects the mouse liver from Pb-induced injury. The underlying mechanism involves antioxidative, anti-inflammatory, and anti-apoptotic processes.

Effects of lead and cadmium co-exposure on liver function in residents near a mining and smelting area in northwestern China

Chronic exposure to environmental cadmium (Cd) and lead (Pb) may have adverse effects on the human health. In this study, we aimed to determine the primary and interactive effects of Cd and Pb exposure on liver function in residents near a mining and smelting area in northwestern China. A total of 451 subjects were recruited, from which blood samples were collected to determine the levels of Cd, Pb, and liver function indices. Additionally, the association between the levels of exposure markers and liver function indices was analysed. Cd and Pb levels were significantly higher in subjects living in the polluted area than in those living in the non-polluted reference area. The liver function levels of subjects in the polluted area were poor compared with those in the reference area. In addition, Cd and Pb levels in the blood were positively associated with gamma glutamyl transpeptidase (GGT) levels and negatively associated with direct bilirubin (DBil) levels. Cd and Pb may be risk factors for abnormal liver function. The risk of abnormal liver function was higher in subjects with moderate Cd and Pb levels, high Cd levels, high Pb levels, and high Cd and Pb levels than in those with low Cd and Pb levels. Our data show that exposure to Cd and/or Pb can cause abnormal liver function. Cd and Pb may have an antagonistic effect on liver function, and high Cd exposure alone has a more profound effect on abnormal liver function compared with co-exposure to Pb and Cd.

Toxicological assessment of low-dose bisphenol A, lead and endosulfan combination: chronic toxicity study in male rats

In the present study, toxic effects, both alone and combined, of bisphenol A (BPA), lead (Pb) and endosulfan (ES) in the low doses were investigated in rat liver and kidney functions. In the study, bisphenol A (BPA), lead (Pb) and endosulfan (ES) were chosen because although they are the chemicals people are most frequently exposed to, no combined toxic effect studies were conducted with these chemicals. Sixty-four male Wistar albino rats were used in the study, and they were randomly divided into eight groups (n = 8 per group); control, BPA (5 mg/kg), Pb (100 ppm), ES (0.61 mg/kg), BPA+Pb, BPA+ES, Pb+ES and BPA+P+ES. The rats were sacrificed after 65 days of treatment. Severe histopathological changes in the liver and kidney tissues were observed in the rats exposed to BPA+Pb+ES combination. Elevated malondialdehyde (MDA) in the liver and decreased superoxide dismutase activity (SOD) in the kidney tissue were detected in the BPA+Pb+ES group compared to those of the control group. It was found that serum alanine aminotransferase (ALT) and blood urea nitrogen (BUN) and creatinine (CREA) levels were higher in the BPA+Pb+ES combination group than the control group. Also, combined exposure of BPA, Pb and ES caused apoptotic cell numbers and inducible nitric oxide (iNOS) to increase in the liver and kidney tissues. The results of the present study suggested that the BPA, Pb and ES caused more dramatic changes to both histological architecture and cell apoptosis in the liver and kidney tissues when there was a combined exposure.

Mitochondrial Dysfunction in Arsenic-Induced Hepatotoxicity: Pathogenic and Therapeutic Implications

Mitochondria are vital cellular organelles associated with energy production as well as cell signaling pathways. These organelles, responsible for metabolism, are highly abundant in hepatocytes that make them key players in hepatotoxicity. The literature suggests that mitochondria are targeted by various environmental pollutants. Arsenic, a toxic metalloid known as an environmental pollutant, readily contaminates drinking water and exerts toxic effects. It is toxic to various cellular organs; among them, the liver seems to be most affected. A growing body of evidence suggests that within cells, arsenic is highly toxic to mitochondria and reported to cause oxidative stress and alter an array of signaling pathways and functions. Hence, it is imperative to highlight the mechanisms associated with altered mitochondrial functions and integrity in arsenic-induced liver toxicity. This review provides the details of mechanistic aspects of mitochondrial dysfunction in arsenic-induced hepatotoxicity as well as various ameliorative measures undertaken concerning mitochondrial functions.

Quercetin and Allicin Can Alleviate the Hepatotoxicity of Lead (Pb) through the PI3K Signaling Pathway

Lead (Pb) is a common toxic heavy metal pollutant in the environment that seriously endangers the health of animals. The liver is a key target organ affected by Pb toxicity. Plant extracts allicin and quercetin have a strong antioxidant capacity that can promote the excretion of heavy metals by improving the body's antioxidant defense and chelating heavy metal ions. To explore the preventive and therapeutic effects of allicin and quercetin on Pb poisoning in chickens, 96 chickens were randomly divided into eight groups: control, Pb, allicin, quercetin, allicin + quercetin, Pb + allicin, Pb + quercetin, and Pb + allicin + quercetin groups. The chickens were given feed containing the above treatments for 90 days. The results indicated that Pb can affect the growth and development of the liver, damage the circulatory system, destroy the structure of mitochondria and nuclei in liver cells, cause an imbalance in the oxidation system, inhibit PI3K protein, and activate the mitochondrial apoptotic pathway. Allicin and quercetin, alone or in combination, can improve the antioxidant capacity of the liver and alleviate liver tissue damage caused by Pb. In summary, allicin and quercetin could alleviate oxidative damage and apoptosis in the Pb-poisoned chicken liver through the PI3K signaling pathway, with stronger effects achieved by their combination.

Lead acetate induces apoptosis in Leydig cells by activating PPARγ/caspase-3/PARP pathway

This study was designed to investigate the cytotoxicity of lead acetate (Pb(AC)₂, a representative air pollutant) by focusing on PPARγ/caspase-3/PARP apoptotic signaling pathway and to explore the inhibitory effect of PPARγ antagonist on apoptosis of TM3 Leydig cells. MTT assay was utilized to examine cell viability. Cell apoptosis was analyzed using a flow cytometry by staining with Annexin V-PE/7AAD staining and a fluorescence microscope by staining with Hoechst 33,258. The levels of apoptosis-related proteins were examined using western blot. From the results, Pb reduced significantly TM3 cell proliferation in concentration- and time-dependent manner. It increased significantly apoptosis; increased the PPARγ, Bax, procaspase-3, cleaved caspase-3, proPARP, cleaved PARP levels; and decreased Bcl-2 level in Pb-treated TM3 cells as compared to control cells. Furthermore, pretreatment with PPARγ antagonist significantly attenuated the apoptosis and cleavage of caspase-3 and PARP induced by Pb. Our results suggested that Pb induced cytotoxicity on TM3 Leydig cells, at least in part, by increasing PPARγ expression, stimulating cleavage of caspase-3 and PARP, and then induced cell apoptosis.

Mitochondrion: a sensitive target for Pb exposure

Pb exposure is a worldwide environmental contamination issue which has been of concern to more and more people. Exposure to environmental Pb and its compounds through food and respiratory routes causes toxic damage to the digestive, respiratory, cardiovascular and nervous systems, etc. Children and pregnant women are particularly vulnerable to Pb. Pb exposure significantly destroys children's learning ability, intelligence and perception ability. Mitochondria are involved in various life processes of eukaryotes and are one of the most sensitive organelles to various injuries. There is no doubt that Pb-induced mitochondrial damage can widely affect various physiological processes and cause great harm. In this review, we summarized the toxic effects of Pb on mitochondria which led to various pathological processes. Pb induces mitochondrial dysfunction leading to the increased level of oxidative stress. In addition, Pb leads to cell apoptosis via mitochondrial permeability transition pore (MPTP) opening. Also, Pb can stimulate the development of mitochondria-mediated inflammatory responses. Furthermore, Pb triggers the germination of autophagy via the mitochondrial pathway and induces mitochondrial dysfunction, disturbing intracellular calcium homeostasis. In a word, we discussed the effects of Pb exposure on mitochondria, hoping to provide some references for further research and better therapeutic options for Pb exposure.

The Antagonistic Effects of Selenium Yeast (SeY) on Cadmium-Induced Inflammatory Factors and the Heat Shock Protein Expression Levels in Chicken Livers

Cadmium (Cd) is a ubiquitous toxic heavy metal in the natural environment that can cause multiple organ damage to the bodies of animals and humans. Selenium yeast (SeY) is a kind of organic selenium (Se) that has a very strong function against Cd-induced injury to tissues or organs. The aim of the current study was to investigate the roles of inflammatory factors and heat shock proteins (HSPs) in inflammatory injury triggered by Cd and to analyze the protective effects of SeY on Cd-induced damnification in the livers of chickens. Two hundred 120-day-old layers were randomly divided into four groups and raised on a conventional diet, or with Se (0.5 mg/kg SeY), Cd (150 mg/kg CdCl₂), or Se + Cd (0.5 mg/kg SeY and 150 mg/kg CdCl₂) in their basic diets for 120 days. Then, the liver histopathology, production of nitric oxide (NO), activity of inducible NO synthase (iNOS), and mRNA and protein expression levels of inflammatory factors (iNOS, NF-κB, TNF-α, and PTGE) and heat shock proteins (HSPs 27, 40, 60, 70, and 90) were examined. The results showed that exposure to Cd obviously increased Cd accumulation, NO production, iNOS activity, inflammatory factor, and HSP mRNA and protein expression levels and further caused an inflammatory response. Supplementation with SeY had an antagonistic effect on Cd-induced inflammatory injury in chicken livers. Thus, the present study suggests that SeY can be taken as a potential therapeutic for Cd-induced liver inflammatory injury in chickens.

Effects of Excess Manganese on the Oxidative Status, and the Expression of Inflammatory Factors and Heat Shock Proteins in Cock Kidneys

Manganese (Mn) can have adverse effects on organisms as a result of heavy or chronic exposure, including neurological damage. This study examined the effects of chronic exposure to manganese chloride (MnCl₂) on various biochemical indices of inflammatory cytokines, antioxidant enzymes, and heat shock proteins (HSPs) in the kidneys of Hy-line cocks. The exposures were carried out using 600, 900, or 1800 mg/kg doses of MnCl₂ administered for periods of 30, 60, and 90 days. The exposure experiments indicated that Mn concentration in the kidneys increased over time and that Mn exposure potentially caused ultrastructural changes to the cells. Treatment with Mn was seen to increase the levels of various biomarkers, including protein carbonyl group content; DNA-protein cross-links (DPCs) and the mRNA expression of inflammatory factors such as tumor necrosis factor-α (TNF-α), nuclear factor-κB p50 (NF-κB p50), cyclooxygenase-2 (COX-2), and prostaglandin E synthase (PGES). The levels of other biomarkers were found to decrease as a result of Mn exposure, including the mRNA expression of oxidation indexes such as copper-zinc superoxide dismutase (CuZn-SOD), manganese superoxide dismutase (Mn-SOD), glutathione peroxidase (GSH-Px), and catalase (CAT). Accompanying the above changes, Mn exposure was seen to result in the relative mRNA and protein expression of HSPs 90, 70, 60, 40, and 27 increasing significantly. Thus, in cock kidneys, HSPs attenuated the biological changes caused by toxic exposure to Mn. This mechanism needs further exploration.

Anti-inflammatory effect of selenium on lead-induced testicular inflammation by inhibiting NLRP3 inflammasome activation in chickens

Lead (Pb) is a deleterious environmental pollutant that is toxic to testes. Selenium (Se) possesses antioxidant and anti-inflammatory properties. Nucleotide-binding domain, leucine-rich-containing family, pyrin-domain containing-3 (NLRP3) inflammasome is involved in inflammatory response. However, the function of NLRP3 inflammasome in antagonistic effect of Se on inflammation caused by Pb remains unknown. The purpose of this research is to identify anti-inflammatory role of Se on testicular toxicity induced by Pb with an emphasis on oxidative stress, inflammation and NLRP3 signaling pathway in chicken. In present study, sixty seven-day-old Hyline male chickens were assigned into four groups. The feeding program consisted of a commercial diet (0.49 mg/kg Se), a Se-supplemented diet (1 mg/kg Se), a Pb-supplemented diet (0.49 mg/kg Se and 350 mg/kg Pb) and a Se-supplemented and Pb-supplemented diet (1 mg/kg Se and 350 mg/kg Pb), respectively. On the 12th week, blood was collected to measure serum testosterone level and testicular tissues were removed to determine Se and Pb concentrations, testicular function, histological structure, oxidative stress indicators and inflammation-related factors (Nuclear factor-kappaB, tumor necrosis factor-α, cyclooxygenase-2, NLRP3, apoptosis-associated speck-like protein containing a caspase recruitment domain, caspase-1, interluekin (IL)-1β, IL-6, IL-18 and interferon-γ). The experimental results showed that after Pb administration, testicular injury was confirmed via histological assessment; testicular dysfunction were further indicated by decreased testosterone level and mRNA expression of steroidogenic acute regulatory protein, cytochrome P450 side-chain cleavage, 3β-hydroxysteroid dehydrogenase and 17β-hydroxysteroid dehydrogenase. Moreover, NLRP3 signaling pathway activated by Pb-caused oxidative stress was up-regulated accompanied by promotion in reactive oxygen species, nitric oxide, inducible nitric oxide synthase and malondialdehyde and reduction in antioxidants including glutathione peroxidase and glutathione s-transferase. Se administration ameliorated testicular tissue injury, testicular function, oxidative stress and inflammation. In conclusion, Se exhibited antagonistic role in Pb-induced testicular injury via enhancing antioxidant system and inhibiting inflammation in chickens.

The imbalance of Th1/Th2 triggers an inflammatory response in chicken spleens after ammonia exposure

Ammonia is a hazardous environmental pollutant that can be harmful to animal health. In this study, we aimed to evaluate the effect of ammonia exposure on broiler chicken spleens. We randomly divided one hundred twenty 1-day-old broiler chickens into 3 groups and raised them with exposure to different ammonia concentrations (low, middle, and high); at 42 D of age, the chicken spleens were extracted. We observed histopathologic changes in spleen tissues by microscopy and measured the expression of Th1/Th2 secreted cytokines (interleukin [IL]-1β, IL-2, IL-4, IL-6, IL-10, interferon-γ [IFN-γ], tumor necrosis factor-α) by RT-PCR. We also measured the expression of nuclear receptor-κB (NF-κB) pathway–related genes (cyclooxygenase-2 [COX-2], nitric oxide synthase [iNOS], and prostaglandin synthetase [PGE]) in spleens by RT-PCR and Western blot analysis. Histopathologic observations indicated that the spleen tissues were seriously injured in the high ammonia concentration group. There was abnormal cytokine expression, including increased IL-4, IL-6, and IFN-γ and decreased IL-2, which indicated an imbalance in the Th1/Th2 response. The proinflammatory factors such as NF-κB, COX-2, iNOS, and PGE were upregulated in the high ammonia group. In conclusion, this study illustrated that ammonia exposure led to a Th1/Th2 immune imbalance and triggered the NF-κB pathway, causing inflammatory damage to the spleen.

Selenium deficiency induced necroptosis, Th1/Th2 imbalance, and inflammatory responses in swine ileum

Selenium (Se) deficiency has a significant impact on the swine breeding industry by inducing digestive system damage and diarrhea. However, the molecular mechanism remains unclear. Our objectives were to investigate if different amounts of necroptosis, inflammatory responses, and T helper cell 1/T helper cell 2 (Th1/Th2) imbalances were induced by Se deficiency in intestinal porcine jejunal epithelial cells (IPEC-J2) and swine ileum tissue. Therefore, Se-deficient models were successfully established both in vitro and in vivo. In the current study, the cell morphological observation results showed that Se deficiency seriously affected the growth and differentiation of IPEC-J2 cells. Moreover, the necroptosis staining and histomorphology observation results showed that the number of necroptotic cells increased significantly, and the ileal tissue exhibited abnormal structures, including necroptotic features and inflammatory cell infiltration, in the Se-deficient group. Furthermore, Se deficiency resulted in accelerated cell necroptosis by increasing (p < .05) the expression of genes related to the tumor necrosis factor-α pathway at both the protein and messenger RNA (mRNA) levels compared to the control group. Moreover, the relative mRNA and protein expression of the inflammatory genes and their responses to dietary Se deficiency were consistent with the resultant Th1/Th2 imbalances in vitro and in vivo. Taken together, the results suggested that Se deficiency caused necroptosis, inflammatory responses, and abnormal expression of cytokines in swine ileum tissue. These findings might help us to explain the damage induced by Se deficiency to the digestive system of swine.

The role of necroptosis and apoptosis through the oxidative stress pathway in the liver of selenium-deficient swine

Necroptosis is regarded as a new paradigm of cell death that plays a key role in the liver damage observed with selenium (Se) deficiency.

Proper cold stimulation starting at an earlier age can enhance immunity and improve adaptability to cold stress in broilers

The effects of long-term cold stimulation on the immune function of ileum and adaptability to cold stress in broilers were examined. A total of 360 Arbor Acres broilers was divided into 3 groups and four replicates per group. C (control) was reared in normal thermal environment. C-3 and C-12 (treatments) were kept in cold condition of 3 or 12°C lower than the temperature of C from days 8 to 42. At day 42, all the groups were exposed to an acute cold stress challenge, designated as S, S-3, and S-12. The mRNA levels of immune molecules and heat shock proteins as well as oxidative stress-related indicators in ileum tissues, and immunoglobulins contents in serum were examined at 14, 42, and 43 d of age. The C-3 regimen had no adverse effect on production performance, whereas the C-12 regimen reduced the production performance relative to C (P < 0.05). At day 42, C-3 had higher levels of immune indexes (P < 0.05), whereas C-12 had lower levels than C (P < 0.05). No differences in levels of oxidative stress-related indicators were found between C and C-3 at day 42 (P > 0.05). S-3 had higher levels of immune indexes and lower levels of oxidative stress-related indicators (P < 0.05), as compared to S and S-12. The results suggest that 34 d of cold stimulation at 3°C lower than the normal temperature had no adverse impacts on production performance but enhanced the immunity of ileum and adaptability to acute cold challenge in broilers.

Epigenetic modifications associated with pathophysiological effects of lead exposure

Lead (Pb) exposure during different stages of development has demonstrated dose, duration, sex, and tissue-specific pathophysiological outcomes due to altered epigenetic regulation via (a) DNA methylation, (b) histone modifications, (c) miRNAs, and (d) chromatin accessibility. Pb-induced alteration of epigenetic regulation causes neurotoxic and extra-neurotoxic pathophysiological outcomes. Neurotoxic effects of Pb include dysfunction of memory and learning, behavioral disorder, attention deficit hyperactivity disorder, autism spectrum disorder, aging, Alzheimer's disease, tauopathy, and neurodegeneration. Extra-neurotoxic effects of Pb include altered body weight, metabolic disorder, cardiovascular disorders, hematopoietic disorder, and reproductive impairment. Pb exposure either early in life or at any stage of development results in undesirable pathophysiological outcomes that tends to sustain and maintain for a lifetime.

Hydrogen Sulfide Gas Exposure Induces Necroptosis and Promotes Inflammation through the MAPK/NF-κB Pathway in Broiler Spleen

Hydrogen sulfide (H2S) is one of the main pollutants in the atmosphere, which is a serious threat to human health. The decomposition of sulfur-containing organics in chicken houses could produce a large amount of H2S, thereby damaging poultry health. In this study, one-day-old broilers were selected and exposed to 4 or 20 ppm of H2S gas (0-3 weeks: 4 ± 0.5 ppm, 4-6 weeks: 20 ± 0.5 ppm). The spleen samples were collected immediately after the chickens were euthanized at 2, 4, and 6 weeks. The histopathological and ultrastructural observations showed obvious necrosis characteristics of H2S-exposed spleens. H2S exposure suppressed GSH, CAT, T-AOC, and SOD activities; increased NO, H2O2, and MDA content and iNOS activity; and induced oxidative stress. ATPase activities and the expressions of energy metabolism-related genes were significantly decreased. Also, the expressions of related necroptosis (RIPK1, RIPK3, MLKL, TAK1, TAB2, and TAB3) were significantly increased, and the MAPK pathway was activated. Besides, H2S exposure activated the NF-κB classical pathway and induced TNF-α and IL-1β release. Taken together, we conclude that H2S exposure induces oxidative stress and energy metabolism dysfunction; evokes necroptosis; activates the MAPK pathway, eventually triggering the NF-κB pathway; and promotes inflammatory response in chicken spleens.

Ammonia exposure induced abnormal expression of cytokines and heat shock proteins via glucose metabolism disorders in chicken neutrophils

Ammonia (NH₃) is a highly irritant, alkaline gas. Atmospheric emission of NH₃ was recognized as an environmental challenge. As a global issue, the NH₃ emission survey with spatially detailed information demonstrated that the sources of atmospheric NH₃ include agriculture (livestock wastes, fertilizers) and some industrial activities. As an environmental pollution, excessive NH₃ exposure can induce many bird dysfunction. Neutrophils respond to multiple invading pathogens through different mechanisms. In order to investigate the effect of NH₃ exposure on broilers' neutrophil, 1-day-old broilers were treated with/without NH₃ for 28 days. We extracted neutrophils from peripheral blood of chicken with/without NH₃ exposure and subsequently stimulated with PMA. Changes of cytokines and inflammatory bodies, heat shock proteins (HSPs), and glucose metabolism of neutrophil were examined in both cases. We not only explored that the index associated with inflammation changed due to NH₃ exposure but also observed the status of neutrophils which was treated with PMA stimulation. After NH₃ exposure, IL-1β and IL-6 were significantly increased on broilers neutrophil. Inflammatory-related factors (NLRP3, ASC, and caspase-1) were significantly elevated. The mRNA expression of HSP70 and HSP90 was increased significantly. All glucose metabolism indicators were reduced. In summary, we concluded that NH₃ enhanced inflammation and disrupted glucose metabolism, and increased the expression of HSPs and inflammatory factors. In addition, the sensitivity of neutrophils to exogenous stimuli was diminished. This information can not only be used to evaluate the damage of NH₃-spiked neutrophils to chickens, but also provide clues for human health pathophysiology caused by excess NH₃, providing valuable information for NH₃ risk management.

Immunosuppression, oxidative stress, and glycometabolism disorder caused by cadmium in common carp (Cyprinus carpio L.): Application of transcriptome analysis in risk assessment of environmental contaminant cadmium

Cadmium (Cd), a hazardous environmental contaminant with irreversible toxicity to fish, has been detected in aquatic environment of many countries. The common carp is one of the most widely distributed fish in the world, so we used common carp to assess environmental contaminant risk. In present study, we investigated effects of Cd on immune function, oxidative defense, and glycometabolism in the spleens of common carp by transcriptome analysis. Obtained 3794 differentially expressed genes (including 1848 up-regulated and 1946 down-regulated genes) were enriched using databases of Kyoto Encyclopedia of Genes and Genomes, and Gene Ontology in David bioinformatics software (version 6.8). The pathways and gene functions of immune, oxidative defense, and glycometabolism were obtained and identified. Some relative genes were validated using qRT-PCR and gene expression of IL-1β, INF-γ, IL-6, Cxcl18b, HO-1a, CAT, GPx1, GCK, and FBA decreased; and gene expression of B4GALT1, GPAT3, and CYP26B1 increased. Our results indicated that Cd exposure led to immunosuppression, oxidative stress, and glycometabolism disorder in the common carp spleens. The present study gives a novel insight and method on environmental risk assessment.

Alterations of antioxidant indexes and inflammatory cytokine expression aggravated hepatocellular apoptosis through mitochondrial and death receptor-dependent pathways in Gallus gallus exposed to arsenic and copper

In this study, we sought to investigate the effects of sub-chronic exposure of arsenic (As) and copper (Cu) on oxidative stress, inflammatory response, and mitochondria and death receptor apoptosis pathways in chicken liver. Seventy-two 1-day-old male Hy-line chickens were treated with basal diet, 30 mg/kg arsenic trioxide (As₂O₃), or/and 300 mg/kg copper sulfate (CuSO₄) for 4, 8, and 12 weeks. Study revealed that exposure to As or/and Cu undermined the antioxidant function and increased lipid peroxidation. Worse yet, liver cell swollen, vacuolar degeneration, and inflammatory cell infiltration were accompanied by an increase of the nuclear factor-κB (NF-κB) and its downstream inflammation-related genes after exposure to As or/and Cu. Furthermore, mitochondria swollen and chromatin condensation were found in As and Cu groups, and hepatocyte nuclear membrane rupture and markedly increased (P < 0.01) apoptosis index were observed in As combined with Cu group. Meanwhile, the transcription and protein expression levels of Bcl-2-associated X protein (Bax), p53, cytochrome c (Cyt c), and caspase-3, 8, 9 were upregulated and B cell lymphoma-2 (Bcl-2) was downregulated in As, Cu, and As + Cu groups in the liver tissues (P < 0.05, P < 0.01). Our results indicated that exposure to As or/and Cu could lead to oxidative stress, inflammatory response, and tissue damage and aggravate hepatocellular apoptosis through mitochondrial and death receptor-dependent pathways in chicken liver. And As and Cu showed a possible synergistic relationship in liver damage.

The critical role of epigallocatechin gallate in regulating mitochondrial metabolism

Epigallocatechin gallate (EGCG), one of polyphenols isolated from green tea, exhibits biology-benefiting effects with minimum severe adverse. EGCG is known to be a mitochondrion-targeting medicinal agent, regulating mitochondrial metabolism, including mitochondrial biogenesis, mitochondrial bioenergetics, and mitochondria-mediated cell cycle and apoptosis. EGCG might exhibit either antioxidative activity to prevent against oxidative stress or pro-oxidative activity to counteract cancer cells, which depends on the cellular stress situations, cell types and the concentration of EGCG. Recent research has gained positive and promising data. This review will discuss the interaction between EGCG and mitochondrion.

The critical role of epigallocatechin gallate in regulating mitochondrial metabolism

Epigallocatechin gallate (EGCG), one of polyphenols isolated from green tea, exhibits biology-benefiting effects with minimum severe adverse. EGCG is known to be a mitochondrion-targeting medicinal agent, regulating mitochondrial metabolism, including mitochondrial biogenesis, mitochondrial bioenergetics, and mitochondria-mediated cell cycle and apoptosis. EGCG might exhibit either antioxidative activity to prevent against oxidative stress or pro-oxidative activity to counteract cancer cells, which depends on the cellular stress situations, cell types and the concentration of EGCG. Recent research has gained positive and promising data. This review will discuss the interaction between EGCG and mitochondrion.