FOXO3 Inhibits the Cisplatin Resistance and Progression of Melanoma Cells by Promoting CDKN1C Transcription.

BACKGROUND: Forkhead box O3 (FOXO3) and cyclin dependent kinase inhibitor 1 C Gene (CDKN1C) have been shown to be involved in the melanoma process, but their roles in the cisplatin (DDP) resistance of melanoma remain unclear. METHODS: The mRNA levels of CDKN1C and FOXO3 were measured using quantitative real-time PCR. The protein levels of CDKN1C, FOXO3 and mitochondrial oxidative phosphorylation (mtOXPHOS)-related markers were determinant by western blot analysis. The DDP resistance, proliferation, and apoptosis of melanoma cells were assessed by cell counting kit 8 assay, colony formation assay and flow cytometry. Glucose consumption, lactate production and ATP level were detected to assess glycolysis. The regulation of FOXO3 on CDKN1C was confirmed by ChIP assay and dual-luciferase reporter assay. In vivo experiments were performed to evaluate the effect of FOXO3 on DDP sensitivity in melanoma tumor tissues. RESULTS: CDKN1C and FOXO3 were downregulated in chemoresistant melanoma tissues, and their low expression levels were related to the poor prognosis of melanoma patients. Overexpression of CDKN1C and FOXO3 repressed DDP resistance, proliferation, and glycolysis, while promoted apoptosis and mtOXPHOS in DDP-resistant melanoma cells. Further analysis suggested that FOXO3 could bind to CDKN1C promoter region to enhance its transcription. Besides, CDKN1C knockdown reversed the regulation of FOXO3 on melanoma cell DDP resistance and progression. Moreover, FOXO3 overexpression enhanced the DDP sensitivity of melanoma tumor tissues in vivo. CONCLUSION: FOXO3 promoted the transcription of CDKN1C, thereby inhibiting the DDP resistance and progression of melanoma cells.

Pan-cancer and multi-omics analyses revealed the diagnostic and prognostic value of BAZ2A in liver cancer.

BAZ2A, an epigenetic regulatory factor that affects ribosomal RNA transcription, has been shown to be highly expressed in several cancers and promotes tumor cell migration. This study explored the expression and mechanism of BAZ2A in tumorigenesis at the pan-cancer level. The Cancer Genome Atlas, Gene Expression Omnibus databases and TIMER2.0, cBioPortal and other tools were used to analyze the level of expression of BAZ2A in various tumor tissues and to examine the relationship between BAZ2A and survival, prognosis, mutation and immune invasion. In vitro experiments were performed to assess the function of BAZ2A in cancer cells. Using combined transcriptome and proteome analysis, we examined the possible mechanism of BAZ2A in tumors. BAZ2A exhibited high expression levels in multiple tumor tissues and displayed a significant association with cancer patient prognosis. The main type of BAZ2A genetic variation in cancer is gene mutation. Downregulation of BAZ2A inhibited proliferation, migration, and invasion and promoted apoptosis in LM6 liver cancer cell. The mechanism of BAZ2A in cancer development may involve lipid metabolism. These results help expand our understanding of BAZ2A in tumorigenesis and development and suggest BAZ2A may serve as a prognostic and diagnostic factor in several cancers.

Structural and biochemical characterization of active sites mutant in human inorganic pyrophosphatase.

Inorganic pyrophosphatases (PPases) are enzymes that catalyze the conversion of inorganic pyrophosphate (PPi) into phosphate (Pi). Human inorganic pyrophosphatase 1 (Hu-PPase) exhibits high expression levels in a variety of tumors and plays roles in cell proliferation, apoptosis, invasion and metastasis, making it a promising prognostic biomarker and a target for cancer therapy. Despite its widespread presence, the catalytic mechanism of Hu-PPase in humans remains inadequately understood. The signature motif amino acid sequence (DXDPXD) within the active sites of PPases is preserved across different species. In this research, an enzymatic activity assay revealed that mutations led to a notable reduction in enzymatic function, although the impact of the four amino acids on the activity of the pocket varied. To investigate the influence of these residues on the substrate binding and enzymatic function of PPase, the crystal structure of the Hu-PPase-ED quadruple mutant (D116A/D118A/P119A/D121A) was determined at 1.69 Å resolution. The resulting structure maintained a barrel-like shape similar to that of the wild-type, albeit lacking Mg2+ ions. Molecular docking analysis demonstrated a decreased ability of Hu-PPase-ED to bind to PPi. Further, molecular dynamics simulation analysis indicated that the mutation rendered the loop of Mg2+ ion-binding residues less stable. Therefore, the effect on enzyme activity did not result from a change in the gross protein structure but rather from a mutation that abolished the Mg2+-coordinating groups, thereby eliminating Mg2+ binding and leading to the loss of enzyme activity.

Collective Cell Radial Ordered Migration in Spatial Confinement.

Collective cells, a typical active matter system, exhibit complex coordinated behaviors fundamental for various developmental and physiological processes. The present work discovers a collective radial ordered migration behavior of NIH3T3 fibroblasts that depends on persistent top-down regulation with 2D spatial confinement. Remarkably, individual cells move in a weak-oriented, diffusive-like rather than strong-oriented ballistic manner. Despite this, the collective movement is spatiotemporal heterogeneous and radial ordering at supracellular scale, manifesting as a radial ordered wavefront originated from the boundary and propagated toward the center of pattern. Combining bottom-up cell-to-extracellular matrix (ECM) interaction strategy, numerical simulations based on a developed mechanical model well reproduce and explain above observations. The model further predicts the independence of geometric features on this ordering behavior, which is validated by experiments. These results together indicate such radial ordered collective migration is ascribed to the couple of top-down regulation with spatial restriction and bottom-up cellular endogenous nature.

Effect of Infusion Set Replacement Intervals on Central Line-Associated Bloodstream Infection in the Intensive Care Unit: Study Protocol of the INSPIRATION Study.

INTRODUCTION: The replacement intervals for infusion sets may differ among healthcare institutions, which may have an impact on the occurrence of central line-associated bloodstream infections (CLABSI). Nevertheless, there exists a limited amount of high-quality evidence available to assist clinicians in determining the most suitable replacement intervals for infusion sets. Therefore, the objective of this trial is to compare the efficacy of 24-h and 96-h replacement intervals for infusion sets on CLABSI among critically ill adults who have central venous access devices. METHODS: This is a multicenter, parallel-group randomized controlled trial that will investigate the effect of infusion set replacement intervals on CLABSI in adult patients admitted to intensive care units (ICUs). The study will enroll 1240 participants who meet the inclusion criteria, which includes being 18 years or older, expected to stay in the ICU for longer than 96 h, and in need of central venous access. Participants will be randomly assigned to either a control group receiving a 96-h replacement interval or a treatment group receiving a 24-h replacement interval. PLANNED OUTCOME: The primary outcome of this trial is the rate of CLABSI within 28 days after randomization. CONCLUSION: This is the first randomized controlled trial to investigate the effects of infusion set replacement at 24-h and 96-h intervals on CLABSI in ICU patients. TRIAL REGISTRATION: ClinicalTrials.gov identifier, NCT05359601.

Microcystin-LR and polystyrene microplastics jointly lead to hepatic histopathological damage and antioxidant dysfunction in male zebrafish.

The co-occurrence of cyanobacterial blooms and nano-microplastic pollution in the water is becoming an emerging risk. To assess the combined hepatotoxicity of microcystin-LR (MC-LR) and polystyrene microplastics (PSMPs) on zebrafish (Danio rerio), male adult zebrafish were exposed to single MC-LR (0, 1, 5, 25 µg/L) and a mixture of MC-LR and PSMPs (100 µg/L). After 60 d exposure, the results indicated that PSMPs significantly increased the MC-LR bioaccumulation in the livers in contrast to the single 25 µg/L MC-LR treatment group. Moreover, the severity of hepatic pathological lesions was aggravated in the MC-LR + PSMPs treatment groups, which were mainly characterized by cellular vacuolar degeneration, swollen hepatocytes, and pyknotic nucleus. The ultrastructural changes also proved that PSMPs combined with MC-LR could enhance the swollen mitochondria and dilated endoplasmic reticulum. The biochemical results, including increased malondialdehyde (MDA) and decreased glutathione (GSH), indicated that PSMPs intensified the MC-LR-induced oxidative damage in the combined treatment groups. Concurrently, alterations of sod1 and keap1a mRNA levels also confirmed that PSMPs together with MC-LR jointly lead to enhanced oxidative injury. Our findings demonstrated that PSMPs enhanced the MC-LR bioavailability by acting as a vector and exacerbating the hepatic injuries and antioxidant dysfunction in zebrafish.

Saracatinib inhibits necroptosis and ameliorates psoriatic inflammation by targeting MLKL.

Necroptosis is a kind of programmed cell death that causes the release of damage-associated molecular patterns and inflammatory disease including skin inflammation. Activation of receptor-interacting serine/threonine kinase 1 (RIPK1), RIPK3, and mixed lineage kinase domain-like protein (MLKL) is the hallmark of tumour necrosis factor α (TNF)-induced necroptosis. Here, we screened a small-molecule compound library and found that saracatinib inhibited TNF-induced necroptosis. By targeting MLKL, Saracatinib interfered with the phosphorylation, translocation, and oligomerization of MLKL induced by TNF. Consistently, mutation of the saracatinib-binding site of MLKL reduced the inhibitory effect of saracatinib on TNF-induced necroptosis. In an imiquimod (IMQ)-induced psoriasis mouse model, saracatinib effectively blocked MLKL phosphorylation and inflammatory responses in vivo. Taken together, these findings indicate that saracatinib inhibits necroptosis by targeting MLKL, providing a potential therapeutic approach for skin inflammation-related diseases such as psoriasis.

Integrated virtual simulation and face-to-face simulation for clinical judgment training among undergraduate nursing students: a mixed-methods study.

BACKGROUND: Virtual simulation and face-to-face simulation are effective for clinical judgment training. Rare studies have tried to improve clinical judgment ability by applying virtual simulation and face-to-face simulation together. This study aimed to evaluate the effect of an integrated non-immersive virtual simulation and high-fidelity face-to-face simulation program on enhancing nursing students' clinical judgment ability and understanding of nursing students' experiences of the combined simulation. METHODS: A sequential exploratory mixed-methods study was conducted in a nursing simulation center of a university in Central China. Third-year nursing students (n = 122) taking clinical training in ICUs were subsequentially assigned to the integrated non-immersive virtual simulation and high-fidelity face-to-face simulation program arm (n = 61) or the face-to-face simulation-only arm (n = 61) according to the order in which they entered in ICU training. Clinical judgment ability was measured by the Lasater Clinical Judgment Rubric (LCJR). Focus group interviews were conducted to gather qualitative data. RESULTS: Students in both arms demonstrated significant improvement in clinical judgment ability scores after simulation, and students in the integrated arm reported more improvement than students in the face-to-face simulation-only arm. The qualitative quotes provided a context for the quantitative improvement measured by the LJCR in the integrated arm. Most of the quantitative findings were confirmed by qualitative findings, including the domains and items in the LJCR. The findings verified and favored the effect of the combination of non-immersive virtual simulation and high-fidelity face-to-face simulation integrated program on enhancing nursing students' clinical judgment ability. CONCLUSIONS: The integrated virtual simulation and face-to-face simulation program was feasible and enhanced nursing students' self-reported clinical judgment ability. This integrated non-immersive virtual simulation and high-fidelity face-to-face simulation program may benefit nursing students and newly graduated nurses in the ICU more than face-to-face simulation only.

Bereaved parents' perceptions of memory making: a qualitative meta-synthesis.

OBJECTIVE: This study aims to investigate the experiences of parents who have experienced bereavement in their efforts to preserve memories of their deceased child. METHODS: Employing a qualitative meta-synthesis approach, this study systematically sought relevant qualitative literature by conducting searches across various electronic databases, including PubMed, Embase, CINAHL, PsycINFO, Web of Science, Cochrane Library, and Wiley, up until July 2023. RESULTS: Nine studies are eligible for inclusion and included in the meta-synthesis. Three overarching categories are identified: (1) Affirming the Significance of Memory Making. (2) Best Practices in Memory Making. (3) Barriers to Effective Memory Making. CONCLUSION: Bereaved parents highly value the act of creating lasting memories, emphasizing its profound significance. While forming these memories, it is imperative to offer family-centered care and honor diverse preferences and needs. It is essential to offer effective support to parents, offering them a range of choices. Furthermore, a more comprehensive examination of memory-making practices is required to better understand their influence on parents' recollections of their deceased child.

Safety and efficacy of intense pulsed light in the treatment of severe chronic ocular graft-versus-host disease.

OBJECTIVE: To investigate the safety and efficacy of intense pulsed light (IPL) in the treatment of severe chronic ocular graft-versus-host disease (coGVHD). METHODS: A prospective cohort study. Seventeen patients with severe coGVHD were selected for inclusion in this study. All subjects were treated with IPL every fortnight together with conventional treatment, observation time points were pre-treatment (W0), 4 weeks post-treatment (W4), 8 weeks post-treatment (W8) and 12 weeks post-treatment (W12). Dry eye related examinations include Tear meniscus height (TMH), Non-invasive break-up time (NIBUT), Schirmer I test, Tear film lipid layer thickness (LLT), Ocular surface staining (OSS) and assessment of meibomian gland. Corneal epithelial cell morphology and inflammatory cell infiltration were analyzed by corneal confocal microscopy, while goblet cell density and squamous epithelial grade were assessed by conjunctival imprinted cytology. RESULTS: Patients did not experience any adverse reactions during the follow-up period. All subjects showed significant improvement in clinical symptoms and most signs after IPL treatment. The corneal confocal microscopy showed that the number of dendritic cells infiltrates in the corneal stroma was significantly reduced after IPL treatment (p < 0.001). Conjunctival blot cytology suggested an increase in the number of conjunctival goblet cells from 5.12 ± 2.71 cells/mm2 before treatment to 22.00 ± 4.58 cells/mm2 after treatment, with a statistically significant difference (p < 0.001). An improvement in conjunctival epithelial cell morphology and a decrease in squamous epithelial grade was also observed. CONCLUSIONS: IPL treatment can effectively increase tear film stability in patients with severe coGVHD without significant side effects.

Validation of the Simplified Chinese Palliative Care Nursing Self-Competence Scale: Two Cross-sectional Studies.

BACKGROUND: Due to the increasing burden of life-limiting illnesses, the need for palliative care has increased. Nurses' palliative care competence is a vital factor in improving its accessibility. A reliable instrument is needed to measure nurses' competence in providing palliative care. OBJECTIVE: Our aim was to translate and culturally adapt the Palliative Care Nursing Self-Competence Scale (PCNSC) into the Palliative Care Nursing Self-Competence Scale-Simplified Chinese (PCNSC-SC). METHODS: Two cross-sectional studies were conducted after content validity had been confirmed during the instrument's translation and adaption. The convergent validity, construct validity, internal consistency, and homogeneity were evaluated in both the first and second studies. Test-retest reliability was assessed only in the first study. Clinical nurses who had a registered nurse qualification certificate and at least 12 months of work experience from a tertiary hospital in Hubei, China participated in the 2 studies. RESULTS: The PCNSC-SC contains 8 dimensions and 34 items, based on goodness-of-fit indices and confirmatory factor analysis. The Cronbach's alpha of the PCNSC-SC was .984 and .990 in the 2 studies, respectively. The test-retest reliability of the PCNSC-SC after 2 weeks was .717. CONCLUSION: The PCNSC-SC can be used to evaluate perceived self-competence in palliative care of Chinese nurses with good reliability and validity.

Repurposing of Ibrutinib and Quizartinib as potent inhibitors of necroptosis.

Necroptosis is a form of regulated cell death that has been implicated in multiple diseases. TNF-induced necroptosis is regulated by necrosomes, complexes consisting of RIPK1, RIPK3 and MLKL. In this study, by screening of a small-compound library, we identified dozens of compounds that inhibited TNF-induced necroptosis. According to the mechanisms by which they inhibited necroptosis, these compounds were classified into different groups. We then identified Ibrutinib as an inhibitor of RIPK3 and found that Quizartinib protected against the TNF-induced systemic inflammatory response syndrome in mice by inhibiting the activation of RIPK1. Altogether, our work revealed dozens of necroptosis inhibitors, suggesting new potential approaches for treating necroptosis-related diseases.

0.01% Hypochlorous Acid Treats Aspergillus fumigatus Keratitis in Rats by Reducing Fungal Load and Inhibiting the Inflammatory Response.

Purpose: To investigate the antifungal and anti-inflammatory effects of 0.01% hypochlorous acid (HCLO) on rats with Aspergillus fumigatus keratitis. Methods: The time-kill assay and broth microdilution procedures were used in vitro to demonstrate that 0.01% HCLO was fungicidal and fungistatic. The severity of the disease was evaluated in vivo using a clinical score and slit-lamp photographs. Fungal load, polymorphonuclear neutrophil infiltration, and the production of related proteins were determined using colony plate counting, in vivo confocal microscopy, periodic acid-Schiff staining, fungal fluorescence staining, immunofluorescence staining, myeloperoxidase assay, and Western blotting. Result: In vitro, 0.01% HCLO can destroy A. fumigatus spores in 1 minute. The optical density of the 0.01% HCLO group was significantly lower than that of the phosphate-buffered saline control group (P < 0.01), and no visible mycelium was observed using a fluorescence microscope. 0.01% HCLO reduced the severity of A. fumigatus keratitis in rats by decreasing the clinical score, fungal loading (periodic acid-Schiff, plate count, and fungal fluorescence staining), and inhibiting neutrophil infiltration and activity (immunofluorescence staining and myeloperoxidase). Furthermore, the Western blot analysis revealed that 0.01% HCO decreased protein expression levels of tumor necrosis factor-α and IL-1ß. Conclusions: According to our findings, 0.01% HCLO can kill A. fumigatus spores in vitro. It has antifungal and anti-inflammatory effects on A. fumigatus keratitis in rats. It also inhibited A. fumigatus growth; decreased neutrophil infiltration, tumor necrosis factor-α, and IL-1ß expression; and provided a potential treatment for fungal keratitis. Translational Relevance: This study provides a potential treatment for fungal keratitis in the clinic.

Global epidemiology of animal influenza infections with explicit virus subtypes until 2016: A spatio-temporal descriptive analysis.

Influenza virus, with a global distribution, diverse animal host range and multiple virus subtypes, has caused several pandemics. To better prepare for the emergence of new subtypes and the possible threat of the next pandemic, the global status of animal influenza must be defined and documented. We created a global database of animal influenza events by searching scientific databases and the primary literature on animal influenza-related events up to and including 2016. The temporal, spatial and host distribution of animal influenza and the diversity of influenza subtypes in different regions were analyzed. A total of 70,472 records and 4712 events of animal influenza throughout the world were identified. Events involving subtypes H5N2, H7N7 and H7N9 were relatively constant, with a slow upward trend during the past decade. Asia was the region with the most clusters of events. Poultry was the main host reported in Asia and Africa, and wild birds in Europe and North America. We found that wild birds carried a very rich array of virus subtypes, a warning for the possible generation of reassortment viruses with pandemic potential. Influenza virus subtype diversity - a risk for virus reassortment - was greatest in Asia, North America and Europe. Our database provides a comprehensive overview of the historical and current status of animal influenza events throughout the world. Influenza surveillance needs to be strengthened in some countries and regions to prevent the emergence of new subtypes. Importantly, improvement of the global influenza surveillance system and structures to enable sharing of surveillance data is very much needed to prepare for the next pandemic.

Inhibition of TMUB1 blocks apoptosis and NF-κB pathway-mediated inflammation in recurrent spontaneous abortion.

INTRODUCTION: Approximately 50% of cases with recurrent spontaneous abortion (RSA) have unexplained etiology. Aberrant expression of transmembrane and ubiquitin-like domain containing 1 (TMUB1) is closely related to a series of diseases, including RSA. However, the function and underlying mechanism of TMUB1 in the occurrence of RSA has not been described. METHODS: TMUB1 expression was detected in the placental villous tissues of 30 women with normal miscarriages and 12 women with RSA. The pregnant mice were injected intraperitoneally with lipopolysaccharide (LPS) to induce abortion. Human chorionic trophoblast cells were treated with LPS. Pathological analysis of placental tissues was performed by hematoxylin and eosin staining. RESULTS: TMUB1 was highly expressed in the placental villous tissues of RSA patients compared to the patients who underwent induced abortions. After LPS administration, the mice exhibited high embryo absorption and pathological alterations, as well as presented an increase in inflammation and apoptosis (the etiology of RSA induction) in placental tissues. Moreover, the upregulated expression of TMUB1 was also found in placental tissues of LPS-induced mice, and further investigation showed that TMUB1 deficiency blocked embryo loss as well as inhibited apoptotic rate and inflammation after LPS activation. Furthermore, we found that the loss of TMUB1 suppressed the phosphorylation of IkappaB kinase (IKK) α/ß and attenuated cytoplasmic-nuclear translocation of nuclear factor-κB (NF-κB) p65 in LPS-induced cells. CONCLUSION: Our results indicate that TMUB1 may involve in the modulation of apoptosis and NF-κB pathway-mediated inflammation in RSA. Therefore, TMUB1 may develop as a potential biomarker for RSA treatment.

Mesenchymal Migration on Adhesive-Nonadhesive Alternate Surfaces in Macrophages.

Mesenchymal migration usually happens on adhesive substrates, while cells adopt amoeboid migration on low/nonadhesive surfaces. Protein-repelling reagents, e.g., poly(ethylene) glycol (PEG), are routinely employed to resist cell adhering and migrating. Contrary to these perceptions, this work discovers a unique locomotion of macrophages on adhesive-nonadhesive alternate substrates in vitro that they can overcome nonadhesive PEG gaps to reach adhesive regions in the mesenchymal mode. Adhering to extracellular matrix regions is a prerequisite for macrophages to perform further locomotion on the PEG regions. Podosomes are found highly enriched on the PEG region in macrophages and support their migration across the nonadhesive regions. Increasing podosome density through myosin IIA inhibition facilitates cell motility on adhesive-nonadhesive alternate substrates. Moreover, a developed cellular Potts model reproduces this mesenchymal migration. These findings together uncover a new migratory behavior on adhesive-nonadhesive alternate substrates in macrophages.

Lutein inhibits tumor progression through the ATR/Chk1/p53 signaling pathway in non-small cell lung cancer.

Lung cancer is the leading cause of cancer-related death. In particular, non-small cell lung cancer (NSCLC) accounts for approximately 85% of all lung cancer cases. Due to tumor resistance and the toxicity of chemotherapeutic agents, it is increasingly critical to discover novel, potent antitumorigenic drugs for treating NSCLC. Lutein, a carotenoid, has been reported to exert toxic effects on cells in several tumor types. However, the detailed functions and underlying mechanisms of lutein in NSCLC remain elusive. The present study showed that lutein significantly and dose-dependently inhibited cell proliferation, arrested the cell cycle at the G0/G1 phase, and induced apoptosis in NSCLC cells. RNA-sequencing analysis revealed that the p53 signaling pathway was the most significantly upregulated in lutein-treated A549 cells. Mechanistically, lutein exerted antitumorigenic effects by inducing DNA damage and subsequently activating the ATR/Chk1/p53 signaling pathway in A549 cells. In vivo, lutein impeded tumor growth in mice and prolonged their survival. In conclusion, our findings demonstrate the antitumorigenic potential of lutein and reveal its molecular mechanism of action, suggesting that lutein is a promising candidate for clinical NSCLC treatment.

Calcium-binding motif-mediated binding of redundant calcium offers a chimeolysin enhanced bactericidal activity and extended host range under physiological conditions.

OBJECTIVES: Calcium-binding motifs are shared by multiple bacteriophage lysins; however, the influence of calcium on the enzymatic activity and host range of these enzymes is still not understood. To address this, ClyF, a chimeric lysin with a putative calcium-binding motif, was used as a model for in vitro and in vivo investigations. METHODS: The concentration of calcium bound to ClyF was determined by atomic absorption spectrometry. The influence of calcium on the structure, activity and host range of ClyF was assessed by circular dichroism and time-kill assays. The bactericidal activity of ClyF was evaluated in various sera and a mouse model of Streptococcus agalactiae bacteraemia. RESULTS: ClyF has a highly negatively charged surface around the calcium-binding motif that can bind extra calcium, thereby increasing the avidity of ClyF for the negatively charged bacterial cell wall. In line with this, ClyF exhibited significantly enhanced staphylolytic and streptolytic activity in various sera containing physiological calcium, including human serum, heat-inactivated human serum, mouse serum and rabbit serum. In a mouse model of S. agalactiae bacteraemia, intraperitoneal administration of a single dose of 25 µg/mouse ClyF fully protected the mice from lethal infection. CONCLUSIONS: The present data collectively showed that physiological calcium improves the bactericidal activity and host range of ClyF, making it a promising candidate for the treatment of infections caused by multiple staphylococci and streptococci.

Sub-chronic ammonia exposure induces hepatopancreatic damage, oxidative stress, and immune dysfunction in red swamp crayfish (Procambarus clarkii).

Ammonia, as one of the primary water pollutants in aquaculture, has been shown to induce a wide range of ecotoxicological effects on aquatic animals. In order to investigate the antioxidant and innate immune responses in crustaceans disrupted by ammonia, red swamp crayfish (Procambarus clarkii) were exposed to 0, 15, 30, and 50 mg/L total ammonia nitrogen for 30 d, the alterations of antioxidant responses as well as innate immunity were studied. The results showed that the severity of hepatopancreatic injury were aggravated by the increasing ammonia levels, which were mainly characterized by tubule lumen dilatation and vacuolization. The swollen mitochondria and disappeared mitochondria ridges suggested that oxidative stress induced by ammonia targets the mitochondria. Concurrently, enhanced MDA levels, and decreased GSH levels as well as the decreased transcription and activity of antioxidant enzymes, including SOD, CAT, and GPx were noticed, which suggested that high concentrations of ammonia exposure induce oxidative stress in P. clarkii. Furthermore, a significant decrease of the hemolymph ACP, AKP, and PO along with the significant downregulation of immune-related genes (ppo, hsp70, hsp90, alf1, ctl) jointly indicated that ammonia stress inhibited the innate immune function. Our findings demonstrated that sub-chronic ammonia stress induced hepatopancreatic injury and exert suppressive effects on the antioxidant capacity as well as innate immunity of P. clarkii. Our results provide a fundamental basis for the deleterious effects of ammonia stress on aquatic crustaceans.