Pro- and anti-inflammatory cytokine expression in immune organs of the common carp exposed to atrazine and chlorpyrifos

Organophosphate pesticide exposure and risk of SARS-CoV-2 infection

Several studies have reported immune modulation by organophosphate (OP) pesticides, but the relationship between OP exposure and SARS-CoV-2 infection is yet to be studied. We used two different measures of OP pesticide exposure (urinary biomarkers (N = 154) and residential proximity to OP applications (N = 292)) to examine the association of early-childhood and lifetime exposure to OPs and risk of infection of SARS-CoV-2 using antibody data. Our study population consisted of young adults (ages 18-21 years) from the Center for the Health Assessment of Mothers and Children of Salinas (CHAMACOS) Study, a longitudinal cohort of families from a California agricultural region. Urinary biomarkers reflected exposure from in utero to age 5 years. Residential proximity reflected exposures between in utero and age 16 years. SARS-CoV-2 antibodies in blood samples collected between June 2022 and January 2023 were detected via two enzyme linked immunosorbent assays, each designed to bind to different SARS-CoV-2 antigens. We performed logistic regression for each measure of pesticide exposure, adjusting for covariates from demographic data and self-reported questionnaire data. We found increased odds of SARS-CoV-2 infection among participants with higher urinary biomarkers of OPs in utero (OR = 1.94, 95% CI: 0.71, 5,58) and from age 0-5 (OR = 1.90, 95% CI: 0.54, 6.95).

Chlorella vulgaris algae ameliorates chlorpyrifos toxicity in Nile tilapia with special reference to antioxidant enzymes and Streptococcus agalactiae infection

BACKGROUND

Chlorpyrifos (CPF) is a widely used pesticide in the production of plant crops. Despite rapid CPF biodegradation, fish were exposed to wastewater containing detectable residues. Recently, medicinal plants and algae were intensively used in aquaculture to replace antibiotics and ameliorate stress impacts.

METHODS AND RESULTS

An indoor experiment was conducted to evaluate the deleterious impacts of CPF pollution on Nile tilapia health and the potential mitigation role of Chlorella vulgaris algae. Firstly, the median lethal concentration LC50 - 72 h of CPF was determined to be 85.8 µg /L in Nile tilapia (35.6 ± 0.5 g body weight) at a water temperature of 27.5 °C. Secondly, fish were exposed to 10% of LC50 - 72 h for six weeks, and tissue samples were collected and examined every two weeks. Also, Nile tilapia were experimentally infected with Streptococcus agalactiae. Exposed fish were immunosuppressed expressed with a decrease in gene expressions of interleukin (IL) 1β, IL-10, and tumor necrosis factor (TNF)-α. Also, a decline was recorded in glutathione peroxidase (GPx), superoxide dismutase (SOD), and catalase (CAT) gene expression in the head kidney tissue. A high mortality rate (MR) of 100% was recorded in fish exposed to CPF for six weeks and challenged with S. agalactiae. Fish that received dietary C. vulgaris could restore gene expression cytokines and antioxidants compared to the control. After six weeks of CPF exposure, fish suffered from anemia as red blood cell count (RBCs), hemoglobin (Hb), and packed cell volume (PCV) significantly declined along with downregulation of serum total protein (TP), globulin (GLO), and albumin (ALB). Liver enzymes were significantly upregulated in fish exposed to CPF pollution, alanine aminotransferase (ALT) (42.5, 53.3, and 61.7 IU/L) and aspartate aminotransferase (AST) (30.1, 31.2, and 22.8) after 2, 4, and 6 weeks, respectively. On S. agalactiae challenge, high MR was recorded in Nile tilapia exposed to CPF (G3) 60%, 60%, and 100% in week 2, week 4, and week 6, and C. vulgaris provided a relative protection level (RPL) of 0, 14.29, and 20%, respectively.

CONCLUSIONS

It was concluded that CPF pollution induces immunosuppressed status, oxidative stress, and anemic signs in Nile tilapia. In contrast, C. vulgaris at a 50 g/kg fish feed dose could partially ameliorate such withdrawals, restoring normal physiological parameters.

Exposure to atrazine stimulates progesterone secretion and induces oxidative stress, inflammation, and apoptosis in the ovary of pseudopregnant rats

Atrazine (ATR) is one of the most commonly used herbicides worldwide. As an endocrine disruptor, it causes ovarian dysfunction, but the mechanism is unclear. We hypothesized that ATR could affect ovarian steroidogenesis, oxidative stress, inflammation, and apoptosis. In the current study, rats aged 28 days were treated with PMSG and HCG to obtain amounts of corpora lutea. Then, rats were injected with ATR (50 mg/kg/day) or saline (0.9%) for 7 days. Sera were collected to detect biochemical indices and progesterone (P4) level, ovaries were collected for antioxidant status, HE, qPCR, and WB analysis. Results showed that ATR exposure affected growth performance as well as serum TP, GLB, and ALB levels, increased serum P4 level and ovarian mRNA and protein levels of StAR, CYP11A1, and HSD3B. ATR treatment increased ovarian mRNA and protein levels of CREB but not PKA expression. ATR treatment increased ovarian mRNA abundances of Nrf-2 and Nqo1, MDA level, and decreased SOD, GST, and T-AOC levels. ATR exposure increased the mRNA abundances of pro-inflammatory cytokines including Tnf-α, Il-1β, Il-6, Il-18, and Inos. ATR exposure increased the mRNA and protein level of Caspase 3 and the ratio of BAX/BCL-2. In conclusion, NRF-2/NQO1 signaling pathway and CREB might be involved in the regulation of ATR in luteal steroidogenesis, oxidative stress, inflammation, and apoptosis in rat ovary.

Influence of triazines and lipopolysaccharide coexposure on inflammatory response and histopathological changes in the testis and liver of BalB/c mice

Background

Triazines are environmental active chemicals that have been reported to alter the inflammatory status of the gonads. We tested the anti-inflammatory effect of the triazines (atrazine; ATZ, simazine; SMZ and cyanazine; CYZ) on the testis and compared it with the more classical liver model that has substantial populations of resident macrophages comparable to the testis.

Methods

BalB/c mice were treated with 25 mg/kg ATZ, SMZ and CYZ for 30 days and injected with lipopolysaccharide (0.5 mg/kg i.p.) 6 h before sacrifice. Myeloperoxidase activity and nitric oxide level in the testis and liver homogenates were determined by spectrophotometry whereas tumor necrosis factor-alpha and interleukin-6 concentrations were evaluated by immunoassay. Haematoxylin and eosin stained sections of the tissues were observed using a light microscope.

Results

Myeloperoxidase activity, nitric oxide, tumor necrosis factor-alpha, and interleukin-6 levels were decreased in the liver and testis of the triazines co-treated animals. SMZ has the most potent inhibitory effect and ATZ the least effect on inflammatory mediators in both tissues. Microscopic evaluation showed loss of inflammatory cells in the inter-tubular areas of the testis and few patchy masses of infiltrating inflammatory cells around the central vein of the liver.

Conclusion

Triazines inhibit the levels of inflammatory mediators in the testis and liver of mice. The anti-inflammatory effect of triazines in a lipopolysaccharide-induced inflammation model was established in this study.

Enterococcus faecium inhibits NF-κB/NLRP3/IL-1β signaling pathway and antagonizes Salmonella-mediated inflammatory response

Aim: This study explored the protective effect of Enterococcus faecium as a probiotic against Salmonella typhimurium infection. Materials & methods: The protective role of E. faecium against tissue damage by S. typhimurium infection and the expression of inflammatory cytokines and tight junction proteins were detected by histological observation, real-time quantitative PCR and immunohistochemical methods. Results: E. faecium demonstrated a regulatory function that affected the expression of Claudin-1 and enhanced tight junctions, suppressed the NF-κB/NLRP3/IL-1β signaling pathway and reduced the release of IL-6, TNF-α, IFN-γ, TLR4 and MYD88 and inflammatory damage to tissues by S. typhimurium in the duodenum, cecum and colon of mice. Conclusion: E. faecium antagonized S. Typhimurium alleviating inflammatory injury in mice through the NF-κB/NLRP3/IL-1β signaling pathway.

Interactive transgenerational effects of parental co-exposure to prochloraz and chlorpyrifos: Disruption in multiple biological processes and induction of genotoxicity

The application of different types of pesticides can result in the coexistence of multiple pesticide residues in our food and the environment. This can have detrimental effects on the health of offspring across generations when parents are exposed to these pesticides. Therefore, it is imperative to understand the long-term effects that can be inherited by future generations when assessing the risks associated with pesticides. To study the genotoxic effects of commonly used pesticides, prochloraz (PRO) and chlorpyrifos (CHL), and assess whether their combined exposures have a different toxic effect, we modeled the transgenerational effects of parental (F0-generation) and/or offspring (F1-generation) exposures on zebrafish embryos in the F1-generation. Following the exposures, we proceeded to assess the impacts of these exposures on a range of biological processes in F1-generation zebrafish. Our results revealed that exposure to PRO and CHL altered multiple biological processes, such as inflammation, apoptosis, oxidative stress, and thyroid hormone synthesis, and detoxification system, providing molecular targets for subsequent studies on toxicity mechanisms. Notably, our study also found that the biological processes of F1-generation zebrafish embryos were altered even though they were not exposed to any pesticide when F0-generation zebrafish were exposed to PRO or CHL, suggesting potential genotoxicity. In conclusion, we provided in-vivo evidence that parental exposure to PRO and/or CHL can induce genotoxicity in the offspring. Moreover, we observed that the toxic effects resulting from the combined exposure were interactive, suggesting a potential synergistic impact on the offspring.

Black soldier fly pulp in the diet of golden pompano: Effect on growth performance, liver antioxidant and intestinal health

Black soldier fly (Hermetia illucens) has been widely researched as a protein source for fish meal replacement in aquaculture, but few studies have focused on its potential as a feed additive for growth and immune enhancement. We conducted a 56-day culture experiment to determine the impact of feed addition of black soldier fly pulp (BSFP, with 86.2% small peptides in dry basis) on growth performance, plasma biochemistry, liver antioxidant levels, intestinal immunity, digestion and microbiota of juvenile golden pompano (Trachinotus ovatus, 5.63 ± 0.02 g). BSFP was added to the basal diet at 0%, 1%, 3%, 5%, 7% and 9% (named Control, BSFP-1, BSFP-3, BSFP-5, BSFP-7, BSFP-9), respectively. BSFP increased the weight gain rate, specific growth rate, protein efficiency ratio and reduced the feed conversion rate of juvenile T. ovatus, the optimal growth performance was reached at BSFP-1, after which a negative feedback phenomenon was observed. Low levels of BSFP upregulated the expression of hepatic antioxidant, intestinal tight junctions, anti-inflammatory related genes and enhanced antioxidant, immune and intestinal digestive enzyme activities, which simultaneously reduced hepatic malondialdehyde and plasma aspartate transaminase and alanine aminotransferase concentrations. However, at BSFP-7, catalase activity was significantly reduced, while NF-κB p65 and pro-inflammatory cytokines transcription was significantly enhanced (P < 0.05). The results suggest that high doses of BSFP addition may damage fish health by inhibiting small peptide uptake, decreasing the activity of antioxidant enzyme and activating the canonical NF-κB pathway. Conversely, low doses of BSFP enhanced intestinal tight junction protein transcription, digestive enzyme activity and immune performance, inhibited pathogenic microbiota, while enhancing liver antioxidant capacity, which was associated with activated Nrf2-Keap1 pathway and suppressed NF-κB pathway, showing its potential as a feed additive to aquafeeds.

Impacts of dietary zinc oxide nanoparticles on the growth and immunity of Nile tilapia could be ameliorated using Nigella sativa oil

BACKGROUND

Zinc nanoparticles are documented to be harmful to fish because their accumulation in fish bring about many irreversible changes in their health. Nigella sativa and its oil have been endorsed in aquaculture to improve fish health.

METHODS

Two hundred seventy experimental fish (113 ± 5 g body weight) were divided into 6 groups G1-6; control fish fed a diet without any treatment (G1), 0.3% of NSO (G2), 0.5% of NSO (G3), ZnO NPs (40 mg/kg diet) (G4), 0.3% of NSO and ZnO NPs (40 mg/kg diet) (G5), 0.5% of NSO and ZnO NPs (40 mg/kg diet) (G6), the trial lasted for six weeks.

RESULTS

Growth performance was enhanced in fish received diets containing NSO, final weight (FW), weight gain (WG), daily weight gain (DWG), and relative growth rate (RGR) were significantly increased with lower food conversion ratios (FCR) compared to the control. The hepatic glutathione peroxidase (GPx), catalase (CAT), and metallothionein (MT) were increased in response to ZnO NPs stress and only 0.5% NSO supplementation could ameliorate such increment. The immune-related genes [interleukin1-beta (IL-1β), tumor necrosis factor-beta (TNF-β), transforming growth factor-beta 2 (TGF-β2) and C-type lysozyme] as well as growth-related gene [insulin-like growth factor 1 (IGF1)] in liver showed an upregulation in fish fed with NSO diets. Administration of ZnO NPs lowered the resistance of Oreochromis niloticus against bacterial infection with Aeromonas hydrophila and NSO could enhance the immunity in the highest tested concentration (0.5%) (G₆).

CONCLUSIONS

The obtained results implied that NSO could enhance the oxidative and immune status of O. niloticus which could compensate ZnO NPs stress as well as experimental infection of a virulent strain of A. hydrophila. Our results revealed that NSO might increase fish growth and immunity only at a high dose (0.5%).

IMMUNOTOXICITY OF RELEVANT MIXTURES OF PESTICIDES AND METABOLITES ON THP-1 CELLS

Pesticides are used to combat agricultural pests but also trigger side effects on non-target organisms. Particularly, immune system dysregulation is a major concern due to the organism's increased vulnerability to diseases, including cancer development. Macrophages play essential roles in innate and adaptive immunity and can undergo classical (M1) or alternative (M2) activation. The M1 pro-inflammatory phenotype has an antitumor role, while M2 favors tumor promotion. Although previous studies have linked pesticide exposure to immune compromise, macrophage polarization is still poorly studied. Here, we investigated the effects of 72 h-long exposure to the mixture of four pesticides widely used in Brazil (glyphosate, 2,4-D, mancozeb, and atrazine), and their main metabolites (aminomethylphosphonic acid, 2,4-diclorophenol, ethylenethiourea, and desethylatrazine) on human leukemia monocytic THP-1 cell line at concentrations based on the Acceptable Daily Intake (ADI) value established in the country. The data revealed immunotoxicity related to impaired cell metabolism in all exposed groups, decreased cell attachment (Pes: 10^-1; Met: 10^-1; Mix: all concentrations), and disturbance in nitric oxide (NO) levels (Met: 10^-1, 10¹; Mix: all concentrations). The polarization of macrophages towards a more pro-tumor M2-like phenotype was also supported by decreased secretion of the pro-inflammatory cytokine TNF-α (Pes 10⁰, 10¹) and increased IL-8 (Pes 10¹). These outcomes alert about the risk of pesticide exposure in the Brazilian population.

Triazine herbicides exposure, natural immunoglobulin M antibodies, and fasting plasma glucose changes: Association and mediation analyses in general Chinese urban adults

The effects of triazine herbicides on glucose metabolism remain unclear. In this study, we aimed to assess the associations between serum triazine herbicides and glycemia-related risk indicators in general adults, and to evaluate the mediating role of natural immunoglobulin M antibodies (IgM) in the above associations among uninfected participants. We measured the concentrations of atrazine, cyanazine, and IgM in serum, as well as fasting plasma glucose (FPG), and fasting plasma insulin in 4423 adult participants from the Wuhan-Zhuhai cohort baseline population, enrolled in 2011-2012. Generalized linear models were used to evaluate the associations of serum triazine herbicides with glycemia-related risk indicators, and mediation analyses were performed to evaluate the mediating role of serum IgM in the above associations. The median levels of serum atrazine and cyanazine were 0.0237 μg/L and 0.0786 μg/L, respectively. Our study found significant positive associations of serum atrazine, cyanazine, and Σtriazine with FPG levels, risk of impaired fasting glucose (IFG), abnormal glucose regulation (AGR), and type 2 diabetes (T2D). Additionally, serum cyanazine and Σtriazine were found to be significant positive associated with the homeostatic model assessment of insulin resistance (HOMA-IR) levels. Significant negative linear relationships were observed in associations of serum IgM with serum triazine herbicides, FPG, HOMA-IR levels, the prevalence of T2D, and AGR (P < 0.05). Furthermore, we observed a significant mediating role by IgM in the associations of serum triazine herbicides with FPG, HOMA-IR, and AGR, with the proportions ranging from 2.96% to 7.71%. To ensure the stability of our findings, we conducted sensitivity analyses in normoglycemic participants and found that the association of serum IgM with FPG and the mediating role by IgM remained stable. Our results suggest that triazine herbicides exposure is positively associated with abnormal glucose metabolism, and decreasing serum IgM may partly mediate these associations.

Molecular and Biochemical Evidence of the Toxic Effects of Terbuthylazine and Malathion in Zebrafish

Our research sought to determine the molecular and biochemical effects of environmentally relevant exposure to commonly used chloro-s-triazine herbicide terbuthylazine and organophosphate insecticide malathion on zebrafish. To this aim, mature zebrafish were exposed to 2 and 30 µg L−1 terbuthylazine and 5 and 50 µg L−1 malathion alone and in combination for 14 days. Aside from the accumulation of TBARS and protein carbonyls, a decrease in antioxidants and succinate dehydrogenase activity, an increase in oxidized glutathione, and enhanced apoptosis via Caspase-3 and BAX overexpression were observed. Furthermore, terbuthylazine and malathion induced mitochondrial swelling (up to 210% after single exposure and up to 470% after co-exposure) and lactate dehydrogenase leakage (up to 268% after single exposure and up to 570% after co-exposure) in a concentration-dependent manner. Significant upregulation of ubiquitin expression and increased cathepsin D activity were characteristics that appeared only upon terbuthylazine exposure, whereas the induction of IgM was identified as the specific characteristic of malathion toxicity. Meanwhile, no alterations in the zebrafish hypothalamic-pituitary-thyroid axis was observed. Co-exposure increased the adverse effects of individual pesticides on zebrafish. This study should improve the understanding of the mechanisms of pesticide toxicity that lead to fish impairment and biodiversity decline.

Healthy lifestyles and wellbeing reduce neuroinflammation and prevent neurodegenerative and psychiatric disorders

Since the mid-20th century, Western societies have considered productivity and economic outcomes are more important than focusing on people's health and wellbeing. This focus has created lifestyles with high stress levels, associated with overconsumption of unhealthy foods and little exercise, which negatively affect people's lives, and subsequently lead to the development of pathologies, including neurodegenerative and psychiatric disorders. Prioritizing a healthy lifestyle to maintain wellbeing may slow the onset or reduce the severity of pathologies. It is a win-win for everyone; for societies and for individuals. A balanced lifestyle is increasingly being adopted globally, with many doctors encouraging meditation and prescribing non-pharmaceutical interventions to treat depression. In psychiatric and neurodegenerative disorders, the inflammatory response system of the brain (neuroinflammation) is activated. Many risks factors are now known to be linked to neuroinflammation such as stress, pollution, and a high saturated and trans fat diet. On the other hand, many studies have linked healthy habits and anti-inflammatory products with lower levels of neuroinflammation and a reduced risk of neurodegenerative and psychiatric disorders. Sharing risk and protective factors is critical so that individuals can make informed choices that promote positive aging throughout their lifespan. Most strategies to manage neurodegenerative diseases are palliative because neurodegeneration has been progressing silently for decades before symptoms appear. Here, we focus on preventing neurodegenerative diseases by adopting an integrated "healthy" lifestyle approach. This review summarizes the role of neuroinflammation on risk and protective factors of neurodegenerative and psychiatric disorders.

Atrazine exposure induces necroptosis through the P450/ROS pathway and causes inflammation in the gill of common carp (Cyprinus carpioL.)

Atrazine (ATR) is used worldwide and has been confirmed be hazardous materials that harmful to the health of organisms. Since ATR was more persistent in the water, the specific damage caused by ATR to aquatic organisms should be concern. The role of P450/ROS has been proposed in many pathomechanisms. To explore whether P450/ROS mediated necroptosis and promote inflammatory response caused by ATR exposure, 120 common carp (Cyprinus carpio L.) were randomly divided into four groups which were exposed to 0 μg/L, 4 μg/L, 40 μg/L and 400 μg/L ATR respectively. The residual levels of ATR and its metabolites increased, signs of necrosis and inflammation were found in the gills of the ATR-treatment groups. The levels of ROS and cytochrome P450 content were increased, and P450 enzymes were activated. The expression levels of the core components of necroptosis (RIPK1, RIPK3 and MLKL) increased. Moreover, gene expression of inflammatory factors (TNF-α, NF-κB, iNOS, COX-2, IL-1β and PTGE) increased significantly in the ATR-spiked group. Our results suggested that ATR exposure triggered necroptosis through the P450/ROS pathway and causes inflammation of common carp gill. This study provides valuable clue about the mechanism by which ATR causes injury to common carp gill.

Tannic acid through ROS/TNF-α/TNFR 1 antagonizes atrazine induced apoptosis, programmed necrosis and immune dysfunction of grass carp hepatocytes

Atrazine (ATR) is a commonly used triazine herbicide, which will remain in the water source, soil and biological muscle tissue for a long time, threatening the survival of related organisms and future generations. Tannic acid (TAN), a glucosyl compound found in gallnuts, has previously been shown to antagonize heavy metal toxicity, antioxidant activity, and inflammation. However, it is unclear whether TAN can antagonize ATR-induced Grass carp hepatocytes (L8824 cells) cytotoxicity. Therefore, we treated L8824 cells with 3 μg mL^-1 ATR for 24 h to establish a toxic group model. The experimental data of flow cytometry and AO/EB staining together showed that the ratio of apoptosis and necrosis in L8824 cells after ATR exposure was significantly higher than that in the control group. Furthermore, RT-qPCR showed that inflammatory factors (TNF-α, IL-1β, IL-6, INF-γ) were up-regulated and antimicrobial peptides (hepcidin, β-defensin and LEAP2) were induced down-regulated in L8824 cells, leading to immune dysfunction. The measurement results of oxidative stress-related indicators showed that the levels of ROS and MDA increased after ATR exposure, the overall anti-oxidative system was down-regulated. Western blotting confirmed that TNF-α/TNFR 1-related genes were also up-regulated. This indicates that ATR stimulates oxidative stress in L8824 cells, which in turn promotes the binding of TNF-α to TNFR 1. In addition, TRADD, FADD, Caspase-3, P53, RIP1, RIP3 and MLKL were found to be significantly up-regulated by Western blotting and RT-qPCR. Conditioned after ATR exposure compared to controls. It indicates that ATR activates apoptosis and necrosis of TNF-α/TNFR 1 pathway by inducing oxidative stress in L8824 cells. Furthermore, the use of TAN (5 μM) significantly alleviated the toxic effects of ATR on L8824 cells mentioned above. In conclusion, TAN restrains ATR-induced apoptosis, programmed necrosis and immune dysfunction through the ROS/TNF-α/TNFR 1 pathway.

Non-target toxic effects of avermectin on carp spleen involve oxidative stress, inflammation, and apoptosis

Avermectin is one of the most widely used pesticides, but its toxicity to non-target organisms, especially aquatic organisms, has been ignored. Therefore, an acute spleen injury model of avermectin in carp was established to assess the non-target toxicity of avermectin to carp. In this study, 3.005 μg/L and 12.02 μg/L were set as the low and high dose groups of avermectin, respectively, and a four days acute exposure experiment was conducted. Pathological structure observation showed that avermectin damaged spleen tissue structure and produced inflammatory cell infiltration. Biochemical analysis showed that avermectin significantly reduced the activities of antioxidant enzymes CAT, SOD, and GSH-px, but increased the content of MDA, a marker of oxidative damage. Avermectin exposure also significantly increased the transcription levels of inflammatory cytokines such as IL-1β, IL-6, TNF-α, and INOS, and also significantly enhanced the activity of the inflammatory mediator iNOS, but suppressed the transcription levels of anti-inflammatory factors TGF-β1 and IL-10. In addition, TUNEL detected that the apoptosis rate increased significantly with the increase of avermectin dosage, and the transcription levels of apoptosis-related genes BAX, P53, and Caspase 3/9 also increased in a dose-dependent manner. This study is preliminary evidence that avermectin induces spleen injury in carp through oxidative stress, inflammation, and apoptosis, which has important implications for subsequent studies on the effects of avermectin on non-target organisms.

Curcumin improves the protective effects of quercetin against atrazine-induced testicular injury in adult Wistar rats

This study evaluated the beneficial protective effect of cotreatment of curcumin (CUR) and quercetin (QUE) on atrazine (ATZ)-induced testicular toxicity in rats. ATZ challenge diminished luteinizing hormone, follicular stimulating hormone, testosterone and myeloperoxidase enzyme activity, but these effects were attenuated on co-treatment with CUR and QUE. Also, co-treatment of CUR + QUE was better than separate administration of QUE at diminishing malondialdehyde and glutathione and improving tumour necrosis factor-α concentration, germ cell numbers (spermatogonia, spermatocytes and round spermatids) and epididymal sperm quality. Histologically, smaller sized tubules with degenerated epithelia and few germ cells were seen in the seminiferous tubules of the ATZ group whereas CUR + QUE pretreatment improved the histo-morphologic features of the tubules compared to the ATZ group and was also better than separate administration of QUE. We conclude that CUR can improve the protective effects of QUE against ATZ-induced testicular injury by enhancing the levels of reproductive hormones, recovering testicular biochemical parameters and improving the histological features of the testes.

Histopathological, Immunohistochemical, And Molecular Alterations In Brain Tissue And Submandibular Salivary Gland Of Atrazine-Induced Toxicity In Male Rats

Atrazine (ATZ) is herbicide that has been widely used for different crops. This extensive use has resulted in severe deleterious effects in different species. In this work, we investigated the potentially harmful effect of atrazine herbicide on the brain and submandibular salivary gland. Our investigation was carried out on 20 adult male albino rats that were equally divided into two groups. The first group received distilled water as control, while the second group received ATZ at 200 mg/kg body weight/ day via stomach gavage for 30 successive days of the experiment; the oral LD50 for ATZ is 3090 mg/kg. Our findings revealed the ability of ATZ to cause damage to the cerebrum, hippocampus, and submandibular salivary gland. This damage resulted from the induced oxidative stress, which was indicated by a significant elevation in malondialdehyde (MDA) concentration, DNA fragmentation, tumor necrotic factor-alpha (TNF-α) expression, with a significant decrease in reduced glutathione (GSH) level and reduction of B cell lymphoma 2 (BCL2), dopamine receptor D1 (Drd1), cAMP-responsive element-binding protein 1 (Creb1) genes expression after ATZ exposure. Moreover, degeneration of cells, cytoplasmic vacuolation, congestion of blood vessels, a strong immune reaction to caspase 3, and negligible immune expression of a glial fibrillary acidic protein (GFAP) were also noticed in the ATZ-treated group. We concluded that ATZ induces oxidative stress and has a toxic and apoptotic effects on the cerebrum, hippocampus, and salivary gland of adult male albino rats.

Immunotoxicological effects of insecticides in exposed fishes

Biologically active compounds used in agriculture that develop near aquatic environments easily spill into rivers or lakes. As a result, insecticides, herbicides and fungicides are observed worldwide in aquatic environments and accumulated in aquatic organism. Many insecticides, including organochlorine and organophosphate, have long been banned long ago because of their high persistence and non-target toxicity. However, previous studies have shown that persistent pesticides remain in aquatic organisms. The immune system is the first defense mechanism against exposure to persistent organic pollutants or pesticides that have been released into the aquatic environment. Many insecticides have been reported to cause immunotoxicity, which is represented by alteration of phagocytic and lysozyme activity. Recent studies show that immunotoxicity by insecticides exerts a more complex mechanism in fish. Insecticides induce immunotoxic effects, such as the release of inflammatory cytokines from head kidney macrophages and inhibition of immune cell proliferation in fish, which can lead to death in severe cases. Even currently used pesticides, such as pyrethroid, with low bioaccumulation have been shown to induce immunotoxicological effects in fish when exposed continuously. Therefore, this review describes the types and bioaccumulation of insecticides that cause immunotoxicity and detailed immunotoxicological mechanisms in fish tissues.

The protective effects of Ziziphora tenuior L. against chlorpyrifos induced toxicity: Involvement of inflammatory and cell death signaling pathway

ETHNOPHARMACOLOGICAL RELEVANCE

Ziziphora tenuior L. is used as a medicinal plant in treatment of various diseases such as gastric disorders, stomach ache, dysentery, uterus infection, gut inflammation and menstruation.

AIM OF THE STUDY

In the present study, the protective effects of Ziziphora tenuior extract against chlorpyrifos (CPF), the most commonly or popularly used insecticide in Asia and Africa were investigated in liver and lung tissues with emphasis in apoptotic and inflammatory pathways in rat model.

MATERIALS AND METHODS

The experiments were performed by gavage of male rats for 8 weeks. The extract of Z. tenuior was administrated at three different doses (40, 80, 160 mg/kg). 6.75 mg/kg CPF was administrated as the maximum tolerable dose based on our previous study.

RESULTS

Our data indicated that CPF can increase the expression of some inflammatory genes (IL-6, TLR-2, IL-1β, TNF-α, and NLPR3) and apoptosis genes (Caspase 3, Caspase 9, Caspase 8 and Bax). On the other hand, it can down regulate Bcl-2 gene expression. Post-treatment of Z. tenuior extract in CPF- treated rats showed significant decrease in apoptotic and inflammatory gene expression in the liver and lung due to its anti-apoptotic effects which confirmed by Bcl-2 gene overexpression.

CONCLUSION

The present study suggested that Z. tenuior extract, as a traditional treatment can be able to moderate CPF toxicity via significant effect on inflammatory and apoptotic cell death signaling pathway. Also, based on our preliminary data, it is suggested that Z. tenuior extract can prevent the adverse effects of CPF in liver and lung tissues.

Recovery of brain cholinesterases and effect on parameters of oxidative stres and apoptosis in quails (Coturnix japonica) after chlorpyrifos and vitamin B1 administration

Chlorpyrifos is a extensively used organophosphate pesticide (OP). In this study, we closely looked into neurotoxicity of CPF and effect of vitamin B1, by checking the levels of cholinesterases, determining the activity of parameters of oxidative stress, inflammation and also level of apoptotic regulator. The study was performed on a total of 80 male Japanese quails (Coturnix japonica), (two control and 6 experimental groups, n = 10). Three group of quails were given by gavage chlorpyrifos (CPF) for 7 consecutive days at doses of 1.50 mg/kg b.w., 3.00 mg/kg b.w., and 6.00 mg/kg b.w. Another three groups were treated with 10 mg/kg b.w. of vitamin B1 i.m. 30 min after CPF application (in above mentioned doses). Our study have proved that all doses of CPF significantly inhibited cholinesterases in brain, while vitamin B1 reactivated them. CPF has led to an increase in the concentration of malondialdehyde (MDA), and activity of catalase (CAT), superoxide dismutase (SOD), glutathione-S-transferase (GST), while tiamin changed the activity of antioxidant enzymes: CAT, SOD, GST. CPF stimulated apoptosis by decreasing B-cell lymphoma (Bcl-2) in brain, while application of vitamin B1 caused an increase of this parameter. CPF amplified inflammatory effect by elevating levels of inducible nitric oxide synthase (iNOS), and cyclooxygenase (COX-2). Thiamine proved its anti-inflammatory property by decreasing the expression of iNOS and interleukin-1(IL-1) and interleukin-6(IL-6). This study is highly pertinent because there is little defense currently available to humans and animals to prevent toxic effects of pesticides.

Antioxidative and immunoprotective potential of Chlorella vulgaris dietary supplementation against chlorpyrifos-induced toxicity in Nile tilapia

This study highlighted the effects of chronic chlorpyrifos (CPF) exposure on Nile tilapia (Oreochromis niloticus) and the benefits of using dietary Chlorella vulgaris (Ch) to ameliorate CPF-induced toxicity. Genes encoding antioxidant enzymes and stress-responsive proteins in the liver as well as cytokine expression in the spleen and head kidney were evaluated in O. niloticus fed with a basal diet or diets containing 1, 2, and 3% of supplementary Ch against 15 mg/L CPF at 4 and 8 weeks. CPF-exposed groups displayed a notable induction in the hepatic expression of heat shock protein 70/hsp70, glutathione peroxidase/GPx, and glutathione synthase/GSS, while glutathione reductase/GSR was markedly decreased. The mRNA levels of interleukin 1β/IL-1β, TNF-α, transforming growth factor β1/TGFβ1, and interleukin 8/ IL-8 in the spleen and head kidney increased significantly after CPF exposure. Interestingly, Ch supplementation, particularly at levels 2 and 3%, was able to modulate the stress and immune-related genes of Nile tilapia sub-chronically exposed to CPF. These outcomes provide valuable insights regarding the toxic impact of chronic exposure to CPF in fish at the molecular level and a better understanding of the Ch dietary vital roles. Besides, our findings encourage adequate monitoring of pesticide levels owing to its impacts on fish health and human as a final consumer.

Comprehensive fitness evaluation of common carp (Cyprinus carpio L.) after twelve weeks of atrazine exposure

Atrazine is frequently detected in surface waters and negatively affect physiological function in aquatic organisms. Even though numerous authors have intensively studied its toxicity, only limited information concerning the long-term fish exposure is available. The aim of this study was evaluation of chronic exposure in common carp. Fish were exposed to a range of atrazine concentrations (0.3 - environmentally relevant concentration; 300; 1000; and 3000 µg/l) for twelve weeks. The potential impact of atrazine exposure was studied using various markers (behaviour; biometrical characteristics; haematological, biochemical and oxidative stress indices and histopathological changes). Most alterations were recorded at the highest concentration (3000 µg/l) which is probably due to a combined effect of both the herbicide exposure and intensive parasite infection development during second week. This group was cancelled after three weeks due to adverse health status, which partly confirmed atrazine immunotoxicity. Chronic exposure resulted in long-term reduction in feed intake followed by a significant decrease in body weight and morphological changes in gill at 1000 µg/l. At the same concentration, significant alterations in haematological (e.g. increase in erythrocyte, leukocyte, lymphocytes and neutrophil counts as well as decrease in monocyte counts) and biochemical (e.g. changes in enzyme activities; increase in glucose; decrease in ammonia) indices were documented, especially during first three weeks. Similar trend, but not so intensive, was observed at 300 µg/l. Moreover, significant changes were observed in various indicators of oxidative stress. These alterations were highly variable with both increasing and decreasing trends depending on dose and analysed tissue. Significant changes, especially in white blood profile, enzyme activities and oxidative stress indices, were proven even at 0.3 µg/l. Obtained results indicate that chronic atrazine exposure of common carp can negatively influence many indicators of health status such as behaviour, immune response, haematological and biochemical profile, oxidative stress indices and organ histopathology.

Atrazine induces necroptosis by miR-181-5p targeting inflammation and glycometabolism in carp lymphocytes

Atrazine (ATR) causes environmental problems and damages the health of fish and aquatic animals. MicroRNAs (miRNAs) play important roles in immune regulation. However, the immunotoxicity mechanism of ATR in fish lymphocytes and the role of miRNA in this process remain unclear. To further study these mechanisms, spleen lymphocytes were exposed to 20, 40 and 60 μg/ml ATR for 18 h. Fluorescence staining and flow cytometry showed that the number of necrotic lymphocytes increased after ATR exposure. Compared with the control group, the mRNA expression of miR-181-5p was inhibited and the mRNA levels of TNF-α and HK2 were increased after ATR exposure. Additionally, the NF-κB inflammatory pathway and the levels of glycometabolism-related genes were upregulated. These results suggest that ATR induces inflammation and elevates glycometabolism in lymphocytes. We further found that the mRNA levels of receptor-interacting serine-threonine kinase 1 (RIP1), receptor-interacting serine-threonine kinase 3 (RIP3), mixed lineage kinase domain-like pseudokinase (MLKL), cylindromatosis (CYLD) and Fas-Associated protein with Death Domain (FADD) and the protein levels of RIP3 and MLKL in the treatment groups were significantly increased compared to those in control group, suggesting that ATR causes lymphocyte necroptosis. We conclude that miR-181-5p plays a key role in necroptosis in carp lymphocytes exposed to ATR by downregulating the expression of HK and TNF-α, which increases the level of glycometabolism and induces the inflammatory response, respectively.

Role of miR-731 and miR-2188-3p in mediating chlorpyrifos induced head kidney injury in common carp via targeting TLR and apoptosis pathways

Chlorpyrifos (CPF) is an environmental pollutant with increasing importance due to its high toxicity to fish and aquatic animals. In the present study, we divided 120 common carp (Cyprinus carpio L.) into two groups including control group and CPF group, CPF group was exposed to 14.5 μg/L CPF for 30 d. 17 miRNAs were differentially expressed in CPF group head kidney tissues according to the results of miRNAome analysis. In addition, histopathological examination and electron microscopy proved that CPF exposure could lead to damage of head kidney and obvious apoptosis characteristics. The possible target genes of miRNA were predicted using online target gene prediction websites, miRNAome sequencing, GO and KEGG enrichment. miRNAome results showed that expression of miR-731 and miR-2188-3p in CPF group was 0.48 time and 0.45 time as control group, respectively. qRT-PCR results proved the reality of miRNAome. During CPF exposure, mRNA expression of TLR pathway genes and its downstream genes involved in autophagy and apoptosis pathway including TLR1, TLR2, TLR7, TLR9, MyD88, IRAK1, IRAK4, IRF7, PI3K, AKT, mTOR, Caspase3, Caspase8 and Bax were differentially increased under CPF exposure, along with ATG13 and Bcl2 decreased at the same time. Western blot results indicated that apoptosis related protein Caspase3 and Caspase8 were differentially up-regulated in the CPF group. In summary, CPF exposure could induce apoptosis while inhibited autophagy in head kidney of common carp via the regulation of miR-2188-3p and miR-731 by targeting TLR pathway. These results provide new insights for unveiling the biological effects of CPF and miRNAs in common carp.

The immune responses of the Chinese rare minnow (Gobiocypris rarus) exposed to environmentally relevant concentrations of cypermethrin and subsequently infected by the bacteria Pseudomonas fluorescens

In the present study, to assess the immunotoxicity of cypermethrin (CYP) in fish, Chinese rare minnows (Gobiocypris rarus) were exposed to environmentally relevant concentrations (0.15, 0.5, and 1.5 μg/L) of CYP for 28 d and subjected to pathogen challenge trials for 2 d. After 28 d of CYP exposure, the levels of Immunoglobulin M (IgM), Alkaline phosphatase (ALP), and C-reactive protein (CRP) were significantly decreased (p < 0.05) after treatment with 1.5 μg/L CYP. Moreover, an induction of inflammatory cytokine transcripts (tnfa, il-6, il-8, and il-12) was observed (p < 0.05) after treatment with 1.5 μg/L CYP. After challenge with Pseudomonas fluorescens (P. fluorescens), plasma lysozyme (LYS) activity at 24 and 48 hours post-injection (hpi) was significantly decreased in the 0.5 and 1.5 μg/L CYP treatment groups (p < 0.05). Moreover, liver Complement component 3 (C3) and CRP contents at 24 hpi were significantly decreased in the 1.5 μg/L CYP treatment group (p < 0.05), whereas significant decreases in liver C3 and IgM contents were observed at 48 hpi (p < 0.05). Inhibition of expression of Toll-like receptor-nuclear factor kappa B (TLR-NF-kB) signaling pathway-related genes was observed in the CYP treatment groups and resulted in significant down-regulation of inflammatory cytokines (il-1β and il-12) in the 1.5 μg/L CYP treatment group at 48 hpi (p < 0.05). Interestingly, the mortality in the 0.5 and 1.5 μg/L CYP treatments was significantly increased at 48 hpi (p < 0.05). These results indicated that environmentally relevant concentrations of CYP suppressed the Chinese rare minnow immune system and reduced immune defense against bacterial infection, thereby causing subsequent mortality. Meanwhile, our results demonstrated that a subsequent host resistance challenge is an effective method for determining the immunotoxicity of chemicals (e.g., CYP).

Atrazine hinders PMA-induced neutrophil extracellular traps in carp via the promotion of apoptosis and inhibition of ROS burst, autophagy and glycolysis

Atrazine (ATR), a selective herbicide, is consistently used worldwide and has been confirmed to be harmful to the health of aquatic organisms. The release of neutrophil extracellular traps (NETs) is one of the newly discovered antimicrobial mechanisms. Although several immune functions have been analyzed under ATR exposure, the effect of ATR on NETs remains mainly unexplored. In the present study, we treated carp neutrophils using 5 μg/ml ATR and 5 μg/ml ATR combined with 100 nM rapamycin to elucidate the underlying mechanisms and to clarify the effect of ATR on phorbol myristate acetate (PMA)-induced NETs. The results of the morphological observation and quantitative analysis of extracellular DNA and myeloperoxidase (MPO) showed that NETs formation were significantly inhibited by ATR exposure. Moreover, we found that in the NETs process, ATR downregulated the expression of the anti-apoptosis gene B-cell lymphoma-2 (Bcl-2), increased the expression of the pro-apoptosis factors Bcl-2-Associated X (BAX), cysteinyl aspartate specific proteinases (Caspase3, 9), and anti-autophagy factor mammalian target of rapamycin (mTOR), decreased the expression of autophagy-related protein light chain 3B (LC3B) and glucose transport proteins (GLUT1, 4), disturbed the activities of phosphofructokinase (PFK), pyruvate kinase (PKM), and hexokinase (HK) and limited reactive oxygen species (ROS) levels, indicating that the reduced NETs release was a consequence of increased apoptosis and diminished ROS burst, autophagy and down-regulated glycolysis under ATR treatment. Meanwhile, rapamycin restored the inhibited autophagy and glycolysis and thus resisted the ATR-suppressed NETs. The present study perfects the mechanism theory of ATR immunotoxicity to fish and has a certain value for human health risk assessment.

Atrazine-xenobiotic nuclear receptor interactions induce cardiac inflammation and endoplasmic reticulum stress in quail (Coturnix coturnix coturnix)

Atrazine (ATR) is one of the most extensively used herbicide that eventually leaches into groundwater and surface water from agricultural areas. Exposure to ATR does harm to the health of human and animals, especially the heart. However, ATR exposure caused cardiotoxicity in bird remains unclear. To evaluate ATR-exerted potential cardiotoxicity in heart, quail were exposed with 0, 50, 250, and 500 mg/kg BW/day ATR by gavage treatment for 45 days. Cardiac histopathological alternation was observed in ATR-induced quail. ATR exposure increased the Cytochrome P450s and Cytochrome b5 contents, Cytochrome P450 (CYP) enzyme system (APND, ERND, AH, and NCR) activities and the expression of CYP isoforms (CYP1B1, CYP2C18, CYP2D6, CYP3A4, CYP3A7, and CYP4B1) in quail heart. The expression of nuclear xenobiotic receptors (NXRs) was also influenced in the heart by ATR exposure. ATR exposure significantly caused the up-regulation of pro-inflammatory cytokines (TNF-α, IL-6, NF-κB, and IL-8), down-regulation of anti-inflammatory cytokines (IL-10) expression levels and increased NO content and iNOS activity. The present research provides new insights into the mechanism that ATR-induced cardiotoxicity through up-regulating the expression levels of GRP78 and XBP-1s, triggering ER stress, activating the expression of IRE1α/TRAF2/NF-κB signaling pathway related factors (IRE1α, TRAF2, IKK, and NF-κB) and inducing an inflammatory response in quail hearts. In conclusion, ATR exposure could induce cardiac inflammatory injury via activating NXRs responses, disrupting CYP homeostasis and CYP isoforms transcription, altering NO metabolism and triggering ER stress and inflammatory response by activating IRE1α/TRAF2/NF-κB signaling pathway.

Under control: The innate immunity of fish from the inhibitors' perspective

The innate immune response involves a concerted network of induced gene products, preformed immune effectors, biochemical signalling cascades and specialised cells. However, the multifaceted activation of these defensive measures can derail or overshoot and, if left unchecked, overwhelm the host. A plenty of regulatory devices therefore mediate the fragile equilibrium between pathogen defence and pathophysiological manifestations. Over the past decade in particular, an almost complete set of teleostean sequences orthologous to mammalian immunoregulatory factors has been identified in various fish species, which prove the remarkable conservation of innate immune-control concepts among vertebrates. This review will present the current knowledge on more than 50 teleostean regulatory factors (plus additional fish-specific paralogs) that are of paramount importance for controlling the clotting cascade, the complement system, pattern-recognition pathways and cytokine-signalling networks. A special focus lies on those immunoregulatory features that have emerged as potential biomarker genes in transcriptome-wide research studies. Moreover, we report on the latest progress in elucidating control elements that act directly with immune-gene-encoding nucleic acids, such as transcription factors, hormone receptors and micro- and long noncoding RNAs. Investigations into the function of teleostean inhibitory factors are still mainly based on gene-expression profiling or overexpression studies. However, in support of structural and in-vitro analyses, evidence from in-vivo trials is also available and revealed many biochemical details on piscine immune regulation. The presence of multiple gene copies in fish adds a degree of complexity, as it is so far hardly understood if they might play distinct roles during inflammation. The present review addresses this and other open questions that should be tackled by fish immunologists in future.

New cytokines and TLR pathway signaling molecules in Chinese rare minnow (Gobiocypris rarus): Molecular characterization, basal expression, and their response to chlorpyrifos

In this study, the cDNA fragments of cytokines (il-8) and toll-like receptor (TLR) pathway signaling molecules (myd88, irak-1, irf5, and irf7) in the Chinese rare minnow were cloned and exhibited a high amino-acid sequence identity compared to other cyprinid fish orthologs. The mRNA expressions of these genes in the different tissues (liver, brain, spleen, kidney, and skin) were observed. The highest expression levels of myd88, irak-1, and irf5 were detected in the spleen, whereas il-8 and irf7 were detected in the kidney and liver respectively. The mRNA expression of irak-1, irf5, and irf7 in the liver from 0.1 μg/L and 0.5 μg/L CPF treatments were significantly increased on day 7 (p < 0.05), whereas the levels of only irak-1 and irf7 were markedly increased on day 28 (p < 0.05). Moreover, the mRNA expression of il-8 in the spleen following 0.5 μg/L CPF treatments was significantly decreased on day 7 (p < 0.05), whereas significantly decrease were observed in the levels of irf7 in the spleen at 2.5 μg/L CPF on days 7 and 28 (p < 0.05). The 0.1 μg/L and 0.5 μg/L of CPF significantly induced the levels of irak-1 and myd88 in the spleen after 28 d exposure (p < 0.05). Therefore, the high induction of cytokines and TLR pathway signaling molecules demonstrated that Chinese rare minnow was immune-compromised exposed to CPF. Moreover, our finding indicated that these immune-related genes could be feasible to screen for substances hazardous to the immune system of fish.

Acute exposure to chlorpyrifos induces reversible changes in health parameters of Nile tilapia (Oreochromis niloticus)

Chlorpyrifos (CPF) is one of the most common insecticides found in freshwater ecosystems, and has been detected in agricultural and fishery products worldwide. This study focused on comprehensive panel of hematological, immunotoxic and pathology changes in Nile tilapia (Oreochromis niloticus) during and after exposure to CPF at 15 μg/L (0.043 μM) (1/10 LC₅₀, group CPF1), or 75 μg/L (0.21 μM) (1/2 LC₅₀, group CPF2) for 14 days, followed by 2 weeks recovery. Different endpoints were used to determine effects of CPF on fish health: hematological parameters; antioxidant levels in liver and gills; innate immune parameters; expression levels of pro-inflammatory cytokine genes at mRNA level in anterior kidney and spleen; and histopathological assessment of gills, liver, and kidney tissues. RBCs were significantly decreased in CPF1 group compared to other groups only at day 3. Blood packed cell volume (PCV) and mean corpuscular volume (MCV) showed significant increase at day 3 and 14 of CPF exposure. TLC (Total Leukocytic Counts), neutrophil counts were significantly increased in CPF exposed groups at days 3, 7, 14 compared to the control. While, lymphocytes counts were significantly increased at CPF1 group compared to other groups at day 14. Antioxidant enzyme activity in liver and gills showed significant increase of Malondialdehyde (MDA) and glutathione (GSH), and significant decrease in (catalase/CAT/, glutathione S-transferase/GST/, and superoxide dismutase/SOD/); in CPF exposed groups. Serum bactericidal and lysozyme activity was nominally and significantly decreased, respectively, and whole blood respiratory burst was significantly increased in CPF2 group. The cytokine expression levels showed complex changes in expression patterns. In kidney, cytokine interleukin-8 (IL-8) was significantly upregulated at day 1 in both exposed group. Interleukin-1β (IL-1β) and Tumor necrosis factor-α (TNFα) were significantly upregulated at day 1 in CPF1 group, and then IL-8 and TNFα downregulated at day 3 in same group. At day 7, only TNFα was up and downregulated in CPF1 and CPF2, respectively compared to control. All gene expression levels in spleen were upregulated on day 7 of exposure in the high exposed group. Histopathology showed dose-dependent changes in CPF treated groups, indicating gill, liver, and posterior kidney changes associated with oxidative stress damages. Following recovery period, all measured parameters showed varying degrees in their reversibility to the control level. These findings provide important insights about the acute toxic effects of CPF on fish and show potential to be used as biomarkers in further toxicological evaluation studies.

Gene Silencing of Selenoprotein K Induces Inflammatory Response and Activates Heat Shock Proteins Expression in Chicken Myoblasts

In the present study, specific small interfering RNA (siRNA) for selenoprotein K (Selk) gene was designed and transfected into chicken myoblasts. Then, the expressions of inflammatory factors (including induced nitric oxide synthase [iNOS], nuclear factor-kappa B [NF-κB], heme-oxygenase-1 [HO-1], cyclooxygenase-2 [COX-2], and prostaglandin E synthase [PTGEs]), inflammation-related cytokines (including interleukin [IL]-1β, IL-6, IL-7, IL-8, IL-17, and interferon [IFN]-γ), and heat shock proteins (HSPs) (including HSP27, HSP40, HSP60, HSP70, and HSP90) were examined at 24 and 72 h after transfection. The results showed that messenger RNA (mRNA) expressions of iNOS, NF-κB, HO-1, COX-2, IL-6, IL-7, IL-8, HSP 27, HSP 40, HSP 60, HSP 70, and HSP 90 were significantly increased (p < 0.05) at 24 and 72 h after siRNA transfection, and the mRNA expressions of PTGEs, IL-1β, IL-17, and IFN-γ were significantly increased and decreased (p < 0.05) at 24 and 72 h after siRNA transfection. The results also showed that the protein expressions of iNOS, NF-κB, HO-1, COX-2, HSP60, HSP70, and HSP90 were significantly increased (p < 0.05) at 24 and 72 h after siRNA transfection. The correlation analysis and principal component analysis (PCA) showed that PTGEs, IL-1β, IL-17, IFN-γ, HSP40, and HSP90 might play special roles in response to Selk silencing in chicken myoblasts. These results indicated that Selk silencing induced inflammation response by affecting the expression levels of inflammatory factors and inflammation-related cytokines, and the heat shock proteins might play protective roles in this response in chicken myoblasts.

Efficacy of Spirulina platensis diet supplements on disease resistance and immune-related gene expression in Cyprinus carpio L. exposed to herbicide atrazine

The present study evaluated the immunotoxicological effects of the herbicide atrazine (ATZ) at sub-lethal concentrations and the potential ameliorative influence of Spirulina platensis (SP) over a sub-chronic exposure period on Cyprinus carpio L., also known as common carp. Common carp was sampled after a 40-days exposure to ATZ (428 μg/L) and SP (1%), individually or in combination to assess the non-specific immune response, changes in mRNA expression of immune-related genes [lysozyme (LYZ), immunoglobulin M (IgM), and complement component 3 (C3)] in the spleen, and inflammatory cytokines (interleukins IL-1ß and IL-10) in the head kidney using real-time PCR. Additionally, disease resistance to Aeromonas sobria was evaluated. The results revealed that ATZ exposure caused a significant decline in most of the hematological variables, lymphocyte viability, and lysozyme and bactericidal activity. Moreover, ATZ increased the susceptibility to disease, reflected by a significantly lower post-challenge survival rate of the carp. ATZ may induce dysregulated expression of immune-related genes leading to downregulation of mRNA levels of IgM and LYZ in the spleen. However, expression of C3 remained unaffected. Of the cytokine-related genes examined, IL-1B was up-regulated in the head kidney. In contrast, the expression of IL-10 gene was down-regulated in the ATZ-exposed group. The SP supplementation resulted in a significant improvement in most indices; however, these values did not match with that of the controls. These results may conclude that ATZ affects both innate and adaptive immune responses through the negative transcriptional effect on genes involved in immunity and also due to the inflammation of the immune organs. In addition, dietary supplements with SP could be useful for modulation of the immunity in response to ATZ exposure, thereby presenting a promising feed additive for carps in aquaculture.

Immunotoxic effects of atrazine and its main metabolites at environmental relevant concentrations on larval zebrafish (Danio rerio)

Atrazine (ATZ) and its main metabolites, i.e., diaminochlorotriazine (DACT), deisopropylatrazine (DIP), and deethylatrazine (DE), have been widely detected in surface water around the world. In the present study, to determine their immunotoxic effects, zebrafish during the early developmental stage were exposed to ATZ and its main metabolites at environmental concentrations (30, 100, 300 μg L^-1). It was observed that ATZ, DACT, DIP and DE selectively induced the transcription of immunotoxic related genes including Tnfα, Il-1β, Il-6, Il-8, Cxcl-clc and Cc-chem in larval zebrafish. Pretreatment with ATZ and its metabolites also changed the immune response of larval zebrafish to LPS and E. coli challenge, which was indicated by the alternation in the mRNA levels of some cytokines. In addition, 300 μg L^-1 ATZ and DACT exposure could also increase the release of tryptase into water, indicating that they increased the anaphylactoid reaction in the larval zebrafish. According to these results, both of ATZ and its metabolites exposure could cause the immunotoxicity in larval zebrafish. Thus, we thought that the ecological risks of the metabolites of ATZ on aquatic organisms could not be ignored.

Occupational and environmental exposure to pesticides and cytokine pathways in chronic diseases (Review)

Pesticides can exert numerous effects on human health as a consequence of both environmental and occupational exposures. The available knowledge base suggests that exposure to pesticides may result in detrimental reproductive changes, neurological dysfunction and several chronic disorders, which are defined by slow evolution and long-term duration. Moreover, an ever increasing amount of data have identified an association between exposure to pesticides and the harmful effects on the immune system. The real impact of alterations in humoral cytokine levels on human health, in particular in the case of chronic diseases, is still unclear. To date, studies have suggested that although exposure to pesticides can affect the immune system functionally, the development of immune disorders depends on the dose and duration of exposure to pesticides. However, many of the respective studies exhibit limitations, such as a lack of information on exposure levels, differences in the pesticide administration procedures, difficulty in characterizing a prognostic significance to the weak modifications often observed and the interpretation of obtained results. The main challenge is not just to understand the role of individual pesticides and their combinations, but also to determine the manner and the duration of exposure, as the toxic effects on the immune system cannot be separated from these considerations. There is a clear need for more well-designed and standardized epidemiological and experimental studies to recognize the exact association between exposure levels and toxic effects and to identify useful biomarkers of exposure. This review focuses on and critically discusses the immunotoxicity of pesticides and the impact of cytokine levels on health, focusing on the development of several chronic diseases.

Oxidative stress related to chlorpyrifos exposure in rainbow trout: Acute and medium term effects on genetic biomarkers

Organophosphates (OPs) are derivatives of phosphoric acid widely used in agriculture as pesticides. Chlorpyrifos (CPF) is an OP that is extremely toxic to aquatic organisms. Rainbow trout (Oncorhynchus mykiss) is considered as a sentinel model species for ecotoxicology assessment in freshwater ecosystems. An exposure study was carried out on rainbow trout to investigate genetic responses to CPF-induced oxidative stress by Real-Time PCR, and to determine the accumulation dynamics of CPF and toxic metabolite chlorpyrifos-oxon (CPF-ox) in edible parts, by HPLC-MS/MS. Among the genes considered to be related to oxidative stress, a significant increase in HSP70 mRNA levels was observed in liver samples up to 14 days after CPF exposure (0.05 mg/L). CPF concentrations in muscle samples reach mean values of 285.25 ng/g within 96 hours of exposure, while CPF-ox concentrations were always under the limit of quantification (LOQ) of the applied method. Our findings lead us to consider HSP70 as a suitable genetic marker in rainbow trout for acute and medium-term monitoring of CPF exposure, complementary to analytical determinations.

Arsenic Trioxide Attenuates NF-κB and Cytokine mRNA Levels in the Livers of Cocks

Arsenic (As) is a trace element widely found in nature. It exists in several forms, including organic arsenic, inorganic arsenic, and trivalent arsenic, the most toxic. Arsenic trioxide (As2O3) is widespread in nature. This form tends to accumulate in animals and humans and therefore has a potential harm for them. Cytokines play essential roles in the immune response and inflammation. Although the importance of cytokines in the responses to arsenic exposure has been demonstrated in many types of mammals, the function of these in poultry, especially in chickens, remains unclear. The purpose of the present study was to examine the effect of As2O3 exposure on cytokines in cock livers. In this study, 72 1-day-old male Hy-line cocks were randomly divided into four groups including the control group, low-As group, middle-As group, and high-As group. The livers were collected on days 30, 60, and 90 of the experiment. The levels of nuclear factor-kappa B (NF-κB), tumor necrosis factor-alpha (TNF-α), interleukin-4 (IL-4), interleukin-6 (IL-6), interleukin-8 (IL-8), interleukin-12 beta (IL-12β), and interleukin-1 beta (IL-1β) mRNA in the livers of the cocks were measured using real-time PCR. The results showed that the expression levels of IL-6, IL-8, TNF-α, and NF-κB which seemed to be a critical mediator in the inflammatory response tended to increase in the birds chronically treated with As2O3. However, the mRNA expression levels of IL-4, IL-12β, and IL-1β were decreased in the experiment. The information regarding the effects of As2O3 on cytokine mRNA expression generated in this study will be important information for arsenic toxicology evaluation.

De novo assembly and characterization of the spleen transcriptome of common carp (Cyprinus carpio) using Illumina paired-end sequencing

Common carp (Cyprinus carpio) is one of the most important aquacultured species of the family Cyprinidae, and breeding this species for disease resistance is becoming more and more important. However, at the genome or transcriptome levels, study of the immunogenetics of disease resistance in the common carp is lacking. In this study, 60,316,906 and 75,200,328 paired-end clean reads were obtained from two cDNA libraries of the common carp spleen by Illumina paired-end sequencing technology. Totally, 130,293 unique transcript fragments (unigenes) were assembled, with an average length of 1400.57 bp. Approximately 105,612 (81.06%) unigenes could be annotated according to their homology with matches in the Nr, Nt, Swiss-Prot, COG, GO, or KEGG databases, and they were found to represent 46,747 non-redundant genes. Comparative analysis showed that 59.82% of the unigenes have significant similarity to zebrafish Refseq proteins. Gene expression comparison revealed that 10,432 and 6889 annotated unigenes were, respectively, up- and down-regulated with at least twofold changes between two developmental stages of the common carp spleen. Gene ontology and KEGG analysis were performed to classify all unigenes into functional categories for understanding gene functions and regulation pathways. In addition, 46,847 simple sequence repeats (SSRs) were detected from 35,618 unigenes, and a large number of single nucleotide polymorphism (SNP) and insertion/deletion (INDEL) sites were identified in the spleen transcriptome of common carp. This study has characterized the spleen transcriptome of the common carp for the first time, providing a valuable resource for a better understanding of the common carp immune system and defense mechanisms. This knowledge will also facilitate future functional studies on common carp immunogenetics that may eventually be applied in breeding programs.

The toxicity of chlorpyrifos on the early life stage of zebrafish: a survey on the endpoints at development, locomotor behavior, oxidative stress and immunotoxicity

Chlorpyrifos (CPF) is one of the most toxic pesticides in aquatic ecosystem, but its toxicity mechanisms to fish are still not fully understood. This study examined the toxicity targets of CPF in early life stage of zebrafish on the endpoints at developmental toxicity, neurotoxicity, oxidative stress and immunotoxicity. Firstly, CPF exposure decreased the body length, inhibited the hatchability and heart rate, and resulted in a number of morphological abnormalities, primarily spinal deformities (SD) and pericardial edema (PE), in larval zebrafish. Secondly, the free swimming activities and the swimming behaviors of the larvae in response to the stimulation of light-to-dark photoperiod transition were significantly influenced by the exposure to 100 and 300 μg/L CPF. In addition, the activity of acetylcholinesterase (AChE) and the transcription of some genes related to neurotoxicity were also influenced by CPF exposure. Thirdly, CPF exposure induced oxidative stress in the larval zebrafish. The malondialdehyde (MDA) levels increased and the glutathione (GSH) contents decreased significantly in a concentration-dependent manner after the exposure to CPF for 96 hours post fertilization (hpf). CPF affected not only the activities of superoxide dismutase (SOD), catalase (CAT), glutathione peroxidase (GPX) and glutathione S-transferase (GST), but also the transcriptional levels of their respective genes. Finally, the mRNA levels of the main cytokines including tumor necrosis factor α (Tnfα), interferon (Ifn), interleukin-1 beta (Il-1β), interleukin 6 (Il6), complement factor 4 (C4) in the larvae increased significantly after the exposure to 100 or 300 μg/L CPF for 96 hpf, suggesting that the innate immune system disturbed by CPF in larvae. Taken together, our results suggested that CPF had the potential to cause developmental toxicity, behavior alterations, oxidative stress and immunotoxicity in the larval zebrafish.