Molecular Events in Response to Triclosan-Induced Oxidative Stress in CRISPR/Cas9-Mediated p53-Targeted Mutants in Daphnia magna.

Triclosan (TCS), a widely used antimicrobial agent, has been implicated in the oxidative stress induction and disruption of cellular processes in aquatic organisms. As TCS is ubiquitous in the aquatic environment, many previous studies have documented the effects of exposure to TCS on aquatic organisms. Nevertheless, most of the research has concentrated on the molecular and physiological responses of TCS, but there are still limited studies on the function of specific genes and the consequences of their absence. In this study, we focused on p53, a gene that is crucial for molecular responses such as autophagy and apoptosis as a result of TCS exposure. In order to ascertain the role and impact of the p53 gene in TCS-induced molecular responses, we examined the molecular responses to TCS-induced oxidative stress in wild-type (WT) and CRISPR/Cas9-mediated p53 mutant (MT) water fleas. The result has been accomplished by examining changes in molecular mechanisms, including in vivo end points, enzyme activities, adenosine triphosphate release rate, and apoptosis, to determine the role and impact of the p53 gene on TCS-induced molecular responses. The results indicated that the sensitivity of MT water fleas to TCS was greater than that of WT water fleas; however, the difference in sensitivity was significant at short exposures within 48 h and decreased toward 48 h. Accordingly, when we confirmed the oxidative stress after 24 h of exposure, the oxidative stress to TCS exposure was stronger in the MT group, with an imbalance of redox. To identify the mechanisms of tolerance to TCS in WT and MT Daphnia magna, we checked mitochondrial and ER-stress-related biomarkers and found an increase in apoptosis and greater sensitivity to TCS exposure in the MT group than in the WT. Our results suggest that the absence of p53 caused alterations in molecular processes in response to TCS exposure, resulting in increased sensitivity to TCS, and that p53 plays a critical role in response to TCS exposure.

Genome-wide identification of 769 G protein-coupled receptor (GPCR) genes from the marine medaka Oryzias melastigma.

The marine medaka Oryzias melastigma is a useful fish model for marine and estuarine ecotoxicology studies and can be applied to field-based population genomics because of its distribution in Asian estuaries and other coastal areas. We identified 769 full-length G protein-coupled receptor genes in the O. melastigma genome and classified them into five distinct classes. A phylogenetic comparison of GPCR genes in O. melastigma to humans and two other small fish species revealed a high-level orthological relationship. Purinergic and chemokine receptors were highly differentiated in humans whereas significant differentiation of chemosensory receptors was evident in fish species. Our results suggest that the GPCR gene families among the species used in this study exhibit evidence of sporadic evolutionary processes. These results may help improve our understanding of the advanced repertoires of GPCR and expand our knowledge of physiological mechanisms of fish in response to various environmental stimuli.

Oxidative stress-mediated deleterious effects of hypoxia in the brackish water flea Diaphanosoma celebensis.

In this study, we investigated the acute toxicity, in vivo effects, oxidative stress, and gene expression changes caused by hypoxia on the brackish water flea Diaphanosoma celebensis. The no-observed-effect concentration (NOEC) of 48 h of hypoxia exposure was found to be 2 mg/L O2. Chronic exposure to NOEC caused a significant decline in lifespan but had no effect on total fecundity. The induction of reactive oxygen species increased in a time-dependent manner over 48 h, whereas the content of antioxidant enzymes (superoxide dismutase and catalase) decreased. The transcription and translation levels were modulated by hypoxia exposure. In particular, a significant increase in hemoglobin level was followed by up-regulation of hypoxia-inducible factor 1α gene expression and activation of the mitogen-activated protein kinase pathway. In conclusion, our findings provide a better understanding of the molecular mechanism of the adverse effects of hypoxia in brackish water zooplankton.

Toxicity and speciation of inorganic arsenics and their adverse effects on in vivo endpoints and oxidative stress in the marine medaka Oryzias melastigma.

Here, we investigate the effects of acute and chronic exposure to arsenate (AsV) and arsenite (AsIII) in the marine medaka Oryzias melastigma. In vivo effects, biotransformation, and oxidative stress were studied in marine medaka exposed to the two inorganic arsenics for 4 or 28 days. An investigation of embryonic development revealed no effect on in vivo parameters, but the hatching rate increased in the group exposed to AsIII. Exposure to AsIII also caused the greatest accumulation of arsenic in medaka. For acute exposure, the ratio of AsV to AsIII was higher than that of chronic exposure, indicating that bioaccumulation of inorganic arsenic can induce oxidative stress. The largest increase in oxidative stress was observed following acute exposure to AsIII, but no significant degree of oxidative stress was induced by chronic exposure. During acute exposure to AsV, the increase in the enzymatic activity of glutathione-S-transferase (GST) was twice as high compared with exposure to AsIII, suggesting that GST plays an important role in the initial detoxification process. In addition, an RNA-seq-based ingenuity pathway analysis revealed that acute exposure to AsIII may be related to cell-cycle progression. A network analysis using differentially expressed genes also revealed a potential link between the generation of inflammatory cytokines and oxidative stress due to arsenic exposure.

Combined exposure to hypoxia and nanoplastics leads to negative synergistic oxidative stress-mediated effects in the water flea Daphnia magna.

In this study, we investigated the combined effects of hypoxia and NPs on the water flea Daphnia magna, a keystone species in freshwater environments. To measure and understand the oxidative stress responses, we used acute toxicity tests, fluorescence microscopy, enzymatic assays, Western blot analyses, and Ingenuity Pathway Analysis. Our findings demonstrate that hypoxia and NPs exhibit a negative synergy that increases oxidative stress, as indicated by heightened levels of reactive oxygen species and antioxidant enzyme activity. These effects lead to more severe reproductive and growth impairments in D. magna compared to a single-stressor exposure. In this work, molecular investigations revealed complex pathway activations involving HIF-1α, NF-κB, and mitogen-activated protein kinase, illustrating the intricate molecular dynamics that can occur in combined stress conditions. The results underscore the amplified physiological impacts of combined environmental stressors and highlight the need for integrated strategies in the management of aquatic ecosystems.

Toxic effects of triclosan in aquatic organisms: A review focusing on single and combined exposure of environmental conditions and pollutants.

Triclosan (TCS) is an antibacterial agent commonly used in personal care products. Due to its widespread use and improper disposal, it is also a pervasive contaminant, particularly in aquatic environments. When released into water bodies, TCS can induce deleterious effects on developmental and physiological aspects of aquatic organisms and also interact with environmental stressors such as weather, metals, pharmaceuticals, and microplastics. Multiple studies have described the adverse effects of TCS on aquatic organisms, but few have reported on the interactions between TCS and other environmental conditions and pollutants. Because aquatic environments include a mix of contaminants and natural factors can correlate with contaminants, it is important to understand the toxicological outcomes of combinations of substances. Due to its lipophilic characteristics, TCS can interact with a wide range of substances and environmental stressors in aquatic environments. Here, we identify a need for caution when using TCS by describing not only the effects of exposure to TCS alone on aquatic organisms but also how toxicity changes when it acts in combination with multiple environmental stressors.

Single and combined effects of increased temperature and methylmercury on different stages of the marine rotifer Brachionus plicatilis.

Rapid, anthropogenic activity-induced global warming is a severe problem that not only raises water temperatures but also shifts aquatic environments by increasing the bioavailability of heavy metals (HMs), with potentially complicated effects on aquatic organisms, including small aquatic invertebrates. For this paper, we investigated the combined effects of temperature (23 and 28 °C) and methylmercury (MeHg) by measuring physiological changes, bioaccumulation, oxidative stress, antioxidants, and the mitogen-activated protein kinase signaling pathway in the marine rotifer Brachionus plicatilis. High temperature and MeHg adversely affected the survival rate, lifespan, and population of rotifers, and bioaccumulation, oxidative stress, and biochemical reactions depended on the developmental stage, with neonates showing higher susceptibility than adults. These findings demonstrate that increased temperature enhances potentially toxic effects from MeHg, and susceptibility differs with the developmental stage. This study provides a comprehensive understanding of the combined effects of elevated temperature and MeHg on rotifers. ENVIRONMENTAL IMPLICATION: Methylmercury (MeHg) is a widespread and harmful heavy metal that can induce lethal effects on aquatic organisms in even trace amounts. The toxicity of metals can vary depending on various environmental conditions. In particular, rising temperatures are considered a major factor affecting bioavailability and toxicity by changing the sensitivity of organisms. However, there are few studies on the combinational effects of high temperatures and MeHg on aquatic animals, especially invertebrates. Our research would contribute to understanding the actual responses of aquatic organisms to complex aquatic environments.

Dendropanoxide Attenuates High Glucose-induced Oxidative Damage in NRK-52E Cells via AKT/mTOR Signaling Pathway.

Hyperglycemia is a potent risk factor for the development and progression of diabetes-induced nephropathy. Dendropanoxide (DPx) is a natural compound isolated from Dendropanax morbifera (Araliaceae) that exerts various biological effects. However, the role of DPx in hyperglycemia-induced renal tubular cell injury remains unclear. The present study explored the protective mechanism of DPx on high glucose (HG)-induced cytotoxicity in kidney tubular epithelial NRK-52E cells. The cells were cultured with normal glucose (5.6 mM), HG (30 mM), HG + metformin (10 µM), or HG + DPx (10 µM) for 48 h, and cell cycle and apoptosis were analyzed. Malondialdehyde (MDA), advanced glycation end products (AGEs), and reactive oxygen species (ROS) were measured. Protein-based nephrotoxicity biomarkers were measured in both the culture media and cell lysates. MDA and AGEs were significantly increased in NRK-52E cells cultured with HG, and these levels were markedly reduced by pretreatment with DPx or metformin. DPx significantly reduced the levels of kidney injury molecule-1 (KIM-1), pyruvate kinase M2 (PKM2), selenium-binding protein 1 (SBP1), or neutrophil gelatinase-associated lipocalin (NGAL) in NRK-52E cells cultured under HG conditions. Furthermore, treatment with DPx significantly increased antioxidant enzyme activity. DPx protects against HG-induced renal tubular cell damage, which may be mediated by its ability to inhibit oxidative stress through the protein kinase B/mammalian target of the rapamycin (AKT/mTOR) signaling pathway. These findings suggest that DPx can be used as a new drug for the treatment of high glucose-induced diabetic nephropathy.

Combined effects of nanoplastics and elevated temperature in the freshwater water flea Daphnia magna.

Global warming and nanoplastics (NPs) are critical global issues. Among NPs, one of the most hazardous types of plastics, polystyrene (PS), poses ecotoxicological threats to several freshwater organisms. The degree of toxicity of PS-NPs is strongly influenced by various environmental factors. This study illustrates the combined effects of temperature and PS-NPs on the water flea Daphnia magna. The sensitivity of D. magna to PS-NPs was tested under control (23 °C) and elevated temperatures (28 °C). As a result, increased temperatures influenced the uptake and accumulation of PS-NPs. Co-exposure to both higher temperatures and PS-NPs resulted in a drastic decrease in reproductive performance. The level of oxidative stress was found to have increased in a temperature-dependent manner. Oxidative stress was stimulated by both stressors, leading to increased levels of reactive oxygen species and antioxidant enzyme activity supported by upregulation of antioxidant enzyme-related genes under combined PS-NPs exposure and elevated temperature. In the imbalanced status of intracellular redox, activation of the p38 mitogen-activated protein kinase signaling pathway was induced by exposure to PS-NPs at high temperatures, which supported the decline of the reproductive capacity of D. magna. Therefore, our results suggest that PS-NPs exposure along with an increase in temperature significantly affects physiological processes triggered by damage from oxidative stress, leading to severely inhibited reproduction of D. magna.

Fine conductive line printing of high viscosity CuO ink using near field electrospinning (NFES).

Modern printed electronics applications require patterning of fine conductive lines of sufficient thickness. However, the two requirements for pattern width and thickness are a trade-off. To print fine pattern at a micrometer size, the nozzle diameter must be approximately the size of the pattern width, so only low-viscosity inks are used. As a result, the pattern is likely to be very thin and multiple overlapping printing is required for sufficient conductance. In order to use high viscosity ink for fine patterning, near field electrospinning (NFES) is attracting attention because it can print very thin and thick patterns using large nozzles (high-viscosity ink). Until now, silver paste ink has been used for microconductive patterning using electrospinning. However, Ag nanoparticle (NP) inks are expensive. In this study, we report the use of a relatively inexpensive CuO NP ink for electrospinning-based printing. For implementation, the material preparation, printing and post-processing process are discussed. For post-processing, a continuous wave (CW) green laser with a 532 nm wavelength was used to reduce the CuO to Cu and sinter the nanoparticles. After sintering, the 50 µm width and 1.48 µm thick Cu conductive line exhibited a resistivity of 5.46 µΩ·cm, which is 3.25 times of the bulk resistivity of Cu.

Physiological effects and molecular response in the marine rotifer Brachionus plicatilis after combined exposure to nanoplastics and copper.

Because nanoplastics (NPs) can transport pollutants, the absorption of surrounding pollutants into NPs and their effects are important environmental issues. This study shows a combined effect of high concentrations of NPs and copper (Cu) in the marine rotifer Brachionus plicatilis. Co-exposure decreased the growth rate, reproduction, and lifespan. The highest level of NP ingestion was detected in the co-treated group, but the Cu concentration was higher in the Cu single-exposure group. ERK activation played a key role in the downstream cell signaling pathway activated by the interaction of NPs and Cu. The increased sensitivity of B. plicatilis to Cu could be due to the impairment of MXR function caused by a high concentration of NPs, which supports our in vivo experiment results. Our results show that exposure to NPs could induce the dysfunction of several critical molecular responses, weakening resistance to Cu and thereby increasing its physiological toxicity in B. plicatilis.

Synergistic toxic mechanisms of microplastics and triclosan via multixenobiotic resistance (MXR) inhibition-mediated autophagy in the freshwater water flea Daphnia magna.

Since a mixed state of environmental contaminants, including microplastics (MPs), heavy metals, pharmaceuticals, and personal care products (PPCPs), exists in aquatic ecosystems, it is necessary to evaluate not only the adverse effects of exposure to a single stressor but to combined stressors. In this study, we exposed the freshwater water flea Daphnia magna to 2 µm MPs and triclosan (TCS), one of PPCPs, for 48 h to investigate the synergistic toxic consequences of simultaneous exposure to both pollutants. We measured in vivo endpoints, antioxidant responses, multixenobiotic resistance (MXR) activity, and autophagy-related protein expression via the PI3K/Akt/mTOR and MAPK signaling pathways. While MPs single exposure did not show toxic effects in water fleas, simultaneous exposure to TCS and MPs was associated with significantly greater deleterious effects in the form of increased mortality and alterations in antioxidant enzymatic activities compared with water fleas exposed to TCS alone. In addition, MXR inhibition was confirmed by measurement of the expression of P-glycoproteins and multidrug-resistance proteins in MPs-exposed groups, which led to the accumulation of TCS. Overall, these results suggest that simultaneous exposure to MPs and TCS resulted in higher TCS accumulation via MXR inhibition, leading to synergistic toxic effects such as autophagy in D. magna.

Case report: a breathtaking complication after ablation-using multi-modal imaging for timely diagnosis of acquired pulmonary vein stenosis and its implication for effective management.

Background: Acquired pulmonary vein stenosis (PVS) is a rare, but serious, complication that can develop after treatment with ablations for atrial fibrillation. Prompt diagnosis is difficult because it can often present similarly to other pulmonary disease processes. Case summary: We describe a 62-year-old female with history of persistent symptomatic atrial fibrillation that resolved status post two radio-frequency ablations who presents with ongoing dyspnoea, productive cough, pleuritic chest pain, and haemoptysis over multiple admissions. She was misdiagnosed with recurrent pneumonias and pulmonary embolism that failed to improve her symptoms. She was referred to our centre for further evaluation finding severe stenosis in the left superior pulmonary vein with complete obliteration of the left inferior pulmonary vein on computed tomography scan. Multi-modal imaging including an echocardiogram and pulmonary angiogram was used to confirm the diagnosis. Percutaneous intervention with transvenous pulmonary vein venoplasty with pulmonary vein stenting of the left upper pulmonary vein was offered which resolved the patient's aforementioned symptoms. Conclusion: Prompt diagnosis of acquired pulmonary vein stenosis is critical to plan for effective management. Our case highlights the need to consider PVS with a high index of clinical suspicion when a patient's medical history is significant for a prior history of ablation. We also review the use of multi-modal imaging to diagnose and plan for effective management with percutaneous intervention.

Dexamethasone Effect on Sudden Hearing Loss is Validated in Stress-induced Animal Models: Hypothetical Study.

BACKGROUND: Stress could be a contributing cause of sudden hearing loss. This study intended to develop an animal model of stress-induced sudden hearing loss and to evaluate the effects of dexamethasone. METHODS: Two stress models (I and II) for rats were designed using various stressors and modified by adjusting the stress protocol to increase the threshold significantly. For the stress model with a significant increase in threshold after stress exposure, changes in cortisol levels according to stress exposure were measured. The threshold shift and the change in the cellular structure associated with stress exposure and dexamethasone administration were analyzed. RESULTS: While hearing thresholds increased only at 16 kHz in rats of stress model I (n=10), the thresholds increased at 16 and 32 kHz in rats of stress model II (n=16). Cortisol level increased after stress exposure (P = .015) in stress model II. Among stress model II rats (stress only and stress+dexamethasone groups), the threshold shift at 16 kHz significantly decreased 1 day after dexamethasone injection in the stress+dexamethasone group (n=8). Histologically, the cochlear cellularity of the stress+dexamethasone group was more compact than that of the stressonly group (n=8). CONCLUSION: Our preliminary study presented the development of an animal model of stress-induced sudden hearing loss and the positive results of steroids in terms of hearing recovery.

Acute toxicity, oxidative stress, and apoptosis due to short-term triclosan exposure and multi- and transgenerational effects on in vivo endpoints, antioxidant defense, and DNA damage response in the freshwater water flea Daphnia magna.

In this study, we measured the acute toxicity of triclosan (TCS) in neonate and adult Daphnia magna water fleas. The median lethal concentrations were 184.689 and 349.511 µg/L, respectively. Oxidative stress induced by TCS was analyzed based on changes in reactive oxygen species (ROS) content and antioxidant enzymatic activities in D. magna. Based on these endpoints, TCS concentrations of 50 and 100 µg/L induced oxidative stress. However, several apoptosis-mediated proteins showed TCS-induced oxidative-stress damage in response to 25 µg/L, indicating that apoptotic proteins were the most sensitive mediators. We also evaluated the multi- and transgenerational effects of TCS on D. magna over three generations in terms of various in vivo endpoints, DNA damage responses, and biochemical reactions. The transgenerational group exposed to TCS exhibited greater negative impacts on antioxidant responses, DNA fragmentation status, and biological endpoints compared with the multigenerational exposure group, leading to decreased reproductive rates and higher ROS content. The transcriptional expression levels of glutathione S-transferase genes in the transgenerational exposure group were upregulated compared to those in the multigenerational group but were fully recovered in F2 offspring. Our findings provide an in-depth understanding of the adaptive effects of multigenerational exposure to TCS.

Anesthetic management using remimazolam in a patient with atrial flutter: a case report.

Remimazolam is a new intravenously administered ultra-short-acting benzodiazepine used in anesthesia or sedation. Remimazolam offers several advantages over other short-acting sedatives, including an organ-independent metabolism and rapid and predictable onset and recovery. Furthermore, remimazolam shows less cardiovascular-inhibitory effects than other anesthetics. Atrial flutter is a form of cardiac arrhythmia that is associated with serious health-related outcomes and a substantial economic burden. Acute onset of atrial flutter can cause cardiac dysfunction, hypotension, and myocardial ischemia. Moreover, patients with atrial flutter are likely to have an increased risk of both atrial fibrillation and stroke. In this case report, a patient with a 1-year history of atrial flutter underwent general anesthesia for robot-assisted laparoscopic prostatectomy. Using continuous remimazolam infusion, anesthesia and surgery were successfully completed without sudden changes in the patient's blood pressure, heart rate, or electrocardiogram. This case report describes the first reported use of remimazolam to induce general anesthesia in a patient with atrial flutter. The findings suggest that remimazolam can reduce the hemodynamic risk during anesthesia in patients with arrhythmias such as atrial flutter, and is a suitable option for anesthesia in patients with arrhythmias.

The unique diagnostic and management challenge of a patient with concomitant anti-interferon-gamma autoantibody associated immunodeficiency syndrome, IgG4-related disease, and treatment refractory, disseminated mycobacterium avium complex infection.

BACKGROUND: Anti-interferon-gamma autoantibody-associated immunodeficiency syndrome is a rare and underrecognized adult onset immunodeficiency syndrome associated with severe opportunistic infections such as disseminated nontuberculous mycobacterium. Few cases have documented a relationship with IgG4-related disease. Concomitant diagnoses of these diseases present a diagnostic and management challenge. CASE PRESENTATION: A 61 year old man of Southeast Asian descent with pulmonary mycobacterium avium complex infection presented to our hospital system with a new skin rash and worsening lymphadenopathy. He was eventually diagnosed with IgG4-related disease through excisional nodal biopsy. He was managed with immunosuppressive treatment with prednisone, rituximab and cyclophosphamide. He later re-presented with disseminated mycobacterium avium complex infiltration of his joints, bones and prostate. Original titers of anti-interferon-gamma autoantibodies were falsely negative due to being on immunosuppressive therapy for his IgG4-related disease. However, anti-interferon-gamma autoantibody titers were re-sent after immunosuppression was held and returned strongly positive. CONCLUSIONS: This case reviews diagnostic criteria and discusses management strategies with existing challenges in treating a patient with concomitant adult onset immunodeficiency syndrome, IgG4-related disease and a disseminated mycobacterial avium complex infection.

Combination Treatment Using Pyruvate Kinase M2 Inhibitors for the Sensitization of High Density Triple-negative Breast Cancer Cells.

BACKGROUND/AIM: Few studies have examined the correlation between pyruvate kinase M2 (PKM2) overexpression and triple-negative breast cancer (TNBC). TNBC is considered incurable with the currently available treatments, highlighting the need for alternative therapeutic targets. MATERIALS AND METHODS: PKM2 expression was examined immunohistochemically in human breast tumor samples. Furthermore, we studied the effect of three PKM2 inhibitors (gliotoxin, shikonin, and compound 3K) in the MDA-MB-231 TNBC cell line. RESULTS: PKM2 overexpression correlates with TNBC. Interestingly, most TNBC tissues showed increased levels of PKM2 compared to those of receptor-positive breast cancer tissues. This suggests that PKM2 overexpression is an important factor in the development of TNBC. MDA-MB-231 TNBC cells are resistant to anticancer drugs, such as vincristine (VIC) compared to other cancer cells. We found that the recently developed PKM2 inhibitor gliotoxin sensitized MDA-MB-231 cells at a relatively low dose to the same extent as the known PKM2 inhibitor shikonin, suggesting that PKM2 inhibitors could be an effective treatment for TNBC. Detailed sensitization mechanisms were also analyzed. Both gliotoxin and shikonin highly increased late apoptosis in MDA-MB-231 cells, as revealed by annexin V staining. However, MDA-MB-231 cells with high cellular density inhibited the sensitizing effect of PKM2 inhibitors; therefore, we investigated ways to overcome this inhibitory effect. We found that gliotoxin+shikonin co-treatment highly increased toxicity in MDA-MB-231 cells with high density, whereas either VIC+gliotoxin or VIC+shikonin were not effective. Thus, combination therapy with various PKM2 inhibitors may be more effective than combination therapy with anticancer drugs. Gliotoxin+shikonin co-treatment did not increase S or G2 arrest in cells, suggesting that the co-treatment showed a high increase in apoptosis without S or G2 arrest. We confirmed that another recently developed PKM2 inhibitor compound 3K had similar mechanisms of sensitizing MDA-MB-231 cells, suggesting that PKM2 inhibitors have similar sensitization mechanisms in TNBC. CONCLUSION: PKM2 is a regulator of the oncogenic function of TNBC, and combination therapy with various PKM2 inhibitors may be effective for high-density TNBC. Targeting PKM2 in TNBC lays the foundation for the development of PKM2 inhibitors as promising anti-TNBC agents.