Normothermic ex vivo kidney perfusion preserves mitochondrial and graft function after warm ischemia and is further enhanced by AP39.

We previously reported that normothermic ex vivo kidney  perfusion (NEVKP) is superior in terms of organ protection compared to static cold storage (SCS), which is still the standard method of organ preservation, but the mechanisms are incompletely understood. We used a large animal kidney autotransplant model to evaluate mitochondrial function during organ preservation and after kidney transplantation, utilizing live cells extracted from fresh kidney tissue. Male porcine kidneys stored under normothermic perfusion showed preserved mitochondrial function and higher ATP levels compared to kidneys stored at 4 °C (SCS). Mitochondrial respiration and ATP levels were further enhanced when AP39, a mitochondria-targeted hydrogen sulfide donor, was administered during warm perfusion. Correspondingly, the combination of NEVKP and AP39 was associated with decreased oxidative stress and inflammation, and with improved graft function after transplantation. In conclusion, our findings suggest that the organ-protective effects of normothermic perfusion are mediated by maintenance of mitochondrial function and enhanced by AP39 administration. Activation of mitochondrial function through the combination of AP39 and normothermic perfusion could represent a new therapeutic strategy for long-term renal preservation.

Correlation of Pseudocholinesterase Level with Clinical, Biochemical Parameters Including Cardiac Profile and the Outcome in Organophosphorus Poisoning.

BACKGROUND: Poisoning is a significant health hazard and a leading cause of morbidity and mortality worldwide. India, being a predominantly agrarian country, routinely employs organophosphate (OP) pesticides in farming, and they are readily available "over the counter." OPs exert their toxicity by interfering with the normal function of acetylcholine, an essential neurotransmitter throughout the autonomic and central nervous systems. Due to the limited availability of facilities and resources in health-care systems, and economically restraining patients, it is necessary to rely more on clinical features to assess the severity of poisoning and manage the condition properly. METHODOLOGY: It was a hospital-based prospective observational study that included patients aged >13 years in a tertiary care hospital. All patients were clinically evaluated based on their history and examination. The diagnosis was made based on characteristic clinical manifestations or evidence of exposure to organophosphorus compounds (corroborative evidence such as empty containers and the odor of gastric aspirates). Clinical severity was assessed and categorized according to the Peradeniya Organophosphorus Poisoning Scale (POP scale). A score of 0-3 is considered mild poisoning, 4-7 as moderate poisoning, and 8-11 as severe poisoning. RESULTS: Out of the 50 patients enrolled in the study, 17 (34.00%) were aged <20 years, 19 (38%) were in the 20-30 years age group, and 14 (28%) were aged >30 years. Ingestion is the only mode of exposure to poisoning. None of the patients had history of contact or inhalational exposure. Of the 50 cases, 12 (24.0%) were in the mild category, 26 (52.0%) in the moderate category, and 12 (24%) in the severe category on the POP grading. A comparison of the mean serum pseudocholinesterase, troponin-T, and pro-BNP levels with severity was performed. In mild OP poisoning, the mean serum PChE level was 2766.58 ± 1120.44; in moderate, it was 1969.35 ± 1330.07, and in severe, it was 701.83 ± 961.17. Pseudocholinesterase levels decreased progressively with increasing clinical severity from mild-to-severe cases, and this association was statistically significant (P < 0.001). Two-dimensional echocardiography screening done in all patients did not show any significant abnormalities. CONCLUSION: This study shows that serum PCE is reduced in OP poisoning and correlates with the clinical severity grading done by the POP scale and is also associated with an increase in the duration of intensive care unit stay. No significant evidence of direct cardiac injury was observed in this study. A low Glasgow Coma Scale score and an increased respiratory rate at presentation are associated with poor outcomes.

Résumé Contexte:L'empoisonnement est un risque important pour la santé et une cause principale de morbidité et de mortalité dans le monde. L'Inde, étant principalement pays agraire, utilise régulièrement des pesticides organophosphotés (OP) dans l'agriculture, et ils sont facilement disponibles «en vente libre¼. OPS exerce leur toxicité en interférant avec la fonction normale de l'acétylcholine, un neurotransmetteur essentiel à travers l'autonomie et le centre systèmes nerveux. En raison de la disponibilité limitée des installations et des ressources dans les systèmes de soins de santé, et de la contention économique des patients, il est nécessaire pour s'appuyer davantage sur les caractéristiques cliniques pour évaluer la gravité de l'empoisonnement et gérer correctement la condition.Méthodologie:c'était un Étude d'observation prospective basée à l'hôpital qui comprenait des patients âgés de> 13 ans dans un hôpital de soins tertiaires. Tous les patients étaient cliniquement évalué en fonction de leur histoire et de leur examen. Le diagnostic a été posé sur la base de manifestations cliniques caractéristiques ou de preuves de Exposition aux composés organophosphores (preuves corroborantes telles que les conteneurs vides et l'odeur des aspirations gastriques). Gravité clinique a été évalué et classé selon l'échelle d'empoisonnement de Peradeniya organophosphorus (échelle pop). Un score de 0 à 3 est considéré comme doux Empoisonnement, 4­7 comme empoisonnement modéré et 8-11 comme empoisonnement sévère.Résultats:Sur les 50 patients inscrits à l'étude, 17 (34,00%) étaient âgés de <20 ans, 19 ans (38%) dans le groupe d'âge de 20 à 30 ans et 14 (28%) étaient âgés de> 30 ans. L'ingestion est le seul mode d'exposition à empoisonnement. Aucun des patients n'avait des antécédents de contact ou d'inhalation. Sur les 50 cas, 12 (24,0%) étaient dans la catégorie légère, 26 (52,0%) Dans la catégorie modérée, et 12 (24%) dans la catégorie sévère sur le classement POP. Une comparaison de la pseudocholinestérase sérique moyenne, Les niveaux de troponine - T et pro-BNP avec gravité ont été réalisés. Dans l'empoisonnement à l'op léger, le taux de PCHE sérique moyen était de 2766,58 ± 1120,44; dans Modéré, c'était 1969.35 ± 1330,07, et en sévère, il était de 701,83 ± 961,17. Les niveaux de pseudocholinestérase ont diminué progressivement avec l'augmentation Gravité clinique des cas légers à sévère, et cette association était statistiquement significative (P <0,001). Échocardiographie bidimensionnelle Le dépistage effectué chez tous les patients n'a montré aucune anomalie significative.Conclusion:cette étude montre que le PCE sérique est réduit en op empoisonnement et corréler avec le classement de gravité clinique effectué par l'échelle POP et est également associé à une augmentation de la durée de séjour de l'unité de soins intensifs. Aucune preuve significative de lésion cardiaque directe n'a été observée dans cette étude. Un score d'échelle de coma à faible Glasgow et un Une fréquence respiratoire accrue à la présentation est associée à de mauvais résultats.

Characterization of the N5-dimethylallyl-FMN Intermediate in the Biosynthesis of Prenylated-FMN Catalyzed by UbiX.

Prenylated-FMN (prFMN) is the cofactor used by the UbiD-like family of decarboxylases that catalyzes the decarboxylation of various aromatic and unsaturated carboxylic acids. prFMN is synthesized from reduced FMN and dimethylallyl phosphate (DMAP) by a specialized prenyl transferase, UbiX. UbiX catalyzes the sequential formation of two bonds, the first between N5 of the flavin and C1 of DMAP, and the second between C6 of the flavin and C3 of DMAP. We have examined the reaction of UbiX with both FMN and riboflavin. Although UbiX converts FMN to prFMN, we show that significant amounts of the N5-dimethylallyl-FMN intermediate are released from the enzyme during catalysis. With riboflavin as the substrate, UbiX catalyzes only a partial reaction, resulting in only N5-dimethylallyl-riboflavin being formed. Purification of the N5-dimethylallyl-FMN adduct allowed its structure to be verified by 1H NMR spectroscopy and its reactivity to be investigated. Surprisingly, whereas reduced prFMN oxidizes in seconds to form the stable prFMN semiquinone radical when exposed to air, N5-dimethylallyl-FMN oxidizes much more slowly over several hours; in this case, oxidation is accompanied by spontaneous hydrolysis to regenerate FMN. These studies highlight the important contribution that cyclization of the prenyl-derived ring of prFMN makes to the cofactor's biological activity.

2-ethylhexyl diphenyl phosphate exposure induces duodenal inflammatory injury through oxidative stress in chickens.

2-ethylhexyl diphenyl phosphate (EHDPHP) is a widely used organophosphorus flame retardant and plasticizer, which is commonly found in the environment. EHDPHP not only potentially harms the environment but also causes different degrees of damage to the organism. In this study, the duodenum of chicks was selected as the potential toxic target organ to explore the mechanism of duodenal injury induced by EHDPHP exposure. Ninety one-day-old healthy male chicks were selected and randomly divided into C1(control group), C2(solvent control group), L(800 mg/kg), M(1600 mg/kg), H(3200 mg/kg) according to different doses of EHDPHP after one week of environmental adaptation. The chicks were given continuous gavage for 14 d, 28 d, and 42 d. It was found that constant exposure to EHDPHP caused an increase in duodenal MDA content, a decrease in P-gp, SOD, GSH-Px activities, and a decrease in duodenal mucosal immune factor (sIgA, GSH-Px). The expression of sIgM and mucosal link proteins (CLDN, OCLN, ZO-1, JAM) decreased, and the expression of the inflammatory protein (NF-κB, COX2) in duodenal tissues was up-regulated. The results showed that continuous exposure to EHDPHP could cause duodenal oxidative stress, inflammation, and mucosal barrier damage in chicks, which provided a basis for studying the mechanism of toxic damage caused by EHDPHP in poultry.

Mechanistic insights into cadmium exacerbating 2-Ethylhexyl diphenyl phosphate-induced human keratinocyte toxicity: Oxidative damage, cell apoptosis, and tight junction disruption.

Organophosphate flame retardants 2-ethylhexyldiphenyl phosphate (EHDPP) and cadmium (Cd) are ubiquitous in environmental matrices, and dermal absorption is a major human exposure pathway. However, their detrimental effects on the human epidermis remain largely unknown. In this study, human keratinocytes (HaCaT cells) were employed to examine the toxicity and underlying mechanisms of co-exposure to EHDPP and Cd. Their influence on cell morphology and viability, oxidative damage, apoptosis, and tight junction were determined. The results showed that co-exposure decreased cell viability by >40 %, induced a higher level of oxidative damage by increasing the generation of reactive oxygen species (1.3 folds) and inhibited CAT (79 %) and GPX (90 %) activities. Moreover, Cd exacerbated EHDPP-induced mitochondrial disorder and cellular apoptosis, which was evidenced by a reduction in mitochondrial membrane potential and an elevation of cyt-c and Caspase-3 mRNA expression. In addition, greater loss of ZO-1 immunoreactivity at cellular boundaries was observed after co-exposure, indicating skin epithelial barrier function disruption, which may increase the human bioavailability of contaminants via the dermal absorption pathway. Taken together, oxidative damage, cell apoptosis, and tight junction disruption played a crucial role in EHDPP + Cd triggered cytotoxicity in HaCaT cells. The detrimental effects of EHDPP + Cd co-exposure were greater than individual exposure, suggesting the current health risk assessment or adverse effects evaluation of individual exposure may underestimate their perniciousness. Our data imply the importance of considering the combined exposure to accurately assess their health implication.

Tris(1-chloro-2-propyl) phosphate enhances the adverse effects of biodegradable polylactic acid microplastics on the mussel Mytilus coruscus.

Microplastics (MPs) and organophosphate flame retardants (OPFRs) have recently become ubiquitous and cumulative pollutants in the oceans. Since OPFRs are added to or adsorbed onto MPs as additives, it is necessary to study the composite contamination of OPFRs and MPs, with less focus on bio-based PLA. Therefore, this study focused on the ecotoxicity of the biodegradable MP polylactic acid (PLA) (5 µm, irregular fragments, 102 and 106 particles/L), and a representative OPFRs tris(1-chloro-2-propyl) phosphate (TCPP, 0.5 and 50 µg/L) at environmental and high concentrations. The mussel Mytilus coruscus was used as a standardised bioindicator for exposure experiments. The focus was on examining oxidative stress (catalase, CAT, superoxide dismutase, SOD, malondialdehyde, MDA), immune responses acid (phosphatase, ACP, alkaline phosphatase, AKP, lysozyme, LZM), neurotoxicity (acetylcholinesterase, AChE), energy metabolism (lactate dehydrogenase, LDH, succinate dehydrogenase, SDH, hexokinase, HK), and physiological indices (absorption efficiency, AE, excretion rate, ER, respiration rate, RR, condition index, CI) after 14 days exposure. The results of significantly increased oxidative stress and immune responses, and significantly disturbed energy metabolism and physiological activities, together with an integrated biomarker response (IBR) analysis, indicate that bio-based PLA MPs and TCPP could cause adverse effects on mussels. Meanwhile, TCPP interacted significantly with PLA, especially at environmental concentrations, resulting in more severe negative impacts on oxidative and immune stress, and neurotoxicity. The more severe adverse effects at environmental concentrations indicate higher ecological risks of PLA, TCPP and their combination in the real marine environment. Our study presents reliable data on the complex effects of bio-based MP PLA, TCPP and their combination on marine organisms and the environment.

Oncogenic and telomeric G-quadruplexes: Targets for porphyrin-triphenylphosphonium conjugates.

DNA chains with sequential guanine (G) repeats can lead to the formation of G-quadruplexes (G4), which are found in functional DNA and RNA regions like telomeres and oncogene promoters. The development of molecules with adequate structural features to selectively stabilize G4 structures can counteract cell immortality, highly described for cancer cells, and also downregulate transcription events underlying cell apoptosis and/or senescence processes. We describe here, the efficiency of four highly charged porphyrins-phosphonium conjugates to act as G4 stabilizing agents. The spectrophotometric results allowed to select the conjugates P2-PPh3 and P3-PPh3 as the most promising ones to stabilize selectively G4 structures. Molecular dynamics simulation experiments were performed and support the preferential binding of P2-PPh3 namely to MYC and of P3-PPh3 to KRAS. The ability of both ligands to block the activity of Taq polymerase was confirmed and also their higher cytotoxicity against the two melanoma cell lines A375 and SK-MEL-28 than to immortalized skin keratinocytes. Both ligands present efficient cellular uptake, nuclear co-localization and high ability to generate 1O2 namely when interacting with G4 structure. The obtained data points the synthesized porphyrins as promising ligands to be used in a dual approach that can combine G4 stabilization and Photodynamic therapy (PDT).

Reduced graphene oxide decorated NiCo2(OH)6 nanoflowers for vortexed assisted dispersive µ-solid-phase extraction of organophosphorus pesticides in baby food cereal, rice and wheat flour.

Food safety is an important issue to protect humane health and improve the life quality. Hence, analysis of the possible contaminants in food samples is essential. A rapid and efficient vortexed-assisted dispersive µ-solid-phase extraction coupled with gas chromatography-mass spectrometry was proposed for simultaneous separation/preconcentration and determination of five commonly used organophosphorus pesticides. Reduced graphene oxide decorated NiCo2(OH)6 nanoflowers as a novel nanostructure was synthetized and introduced for separation of the target pesticides from the wheat flour, rice flour, and baby food cereal samples. The characterization of the nanoflowers was accomplished by SEM-EDX, XRD, and FT-IR techniques. The main factors including pH, the amount of nanoflower, the volume of sample solution, salt concentration (ionic strength), desorption conditions (i.e. desorption solvent type and volume, and desorption time) on the pesticides extraction efficiencies were inquired using matrixed match method. Applying the optimum conditions, the linearity of 0.100-500.000 µg kg-1, LODs and LOQs in the range of 0.03-0.04 µg kg-1 and 0.1 µg kg-1 for the studied food samples were obtained. The repeatability (intra-day precision (n = 5)) of ≤ 2.0 % and reproducibility (inter-day precision, days = 5, n = 3) of ≤3.1 % and were appraise at three concentration levels (10, 50 and 100 µg kg-1 of each analyte). High relative recoveries of 90.0-99.3 % ascertained high potential of the presented method for complex matrix analysis.

Simultaneous determination of quaternary phosphonium compounds and phosphine oxides in environmental water and solid samples by ultrahigh performance liquid chromatography-tandem mass spectrometry.

Quaternary phosphonium compounds (QPCs) and phosphine oxides (POs) are emerging contaminants that are attracting increasing attention. In the present study, a method for the quantification of QPCs and POs in multiple environmental media was developed using ultrahigh performance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS). Analytes were extracted from water samples using solid phase extraction, and for the solid samples, ultrasonic extraction was employed. Compared with analytical methods established by previous studies, the approach developed in this study is more suitable for the quantitative analysis of compounds along with high sensitivity. The method quantification limit reached 0.12-2.55 ng⋅L-1 in water samples and 0.004-0.10 ng⋅g-1 in solid samples. The recoveries of target analytes spiked at low, medium and high concentrations in water and solid samples were in the range of 56.4-120 %, with relative standard deviations below 20 % (n = 6). Furthermore, the validated method succeeded in applying to analyse of eight QPCs and four POs in real environmental samples. At least five QPCs and two POs were detected in each environmental medium. This quantitative method would assist in further investigations on the occurrence, migration and the source of QPCs and POs.

Physiological and transcriptomic changes of zebrafish (Danio rerio) in response to Isopropylate Triphenyl Phosphate (IPPP) exposure.

Isopropylate Triphenyl Phosphate (IPPP), a novel organophosphorus flame retardant, has become a widespread environmental pollutant. However, the toxic effects and mechanisms of IPPP remain unclear. In this study, we evaluated the neurodevelopmental toxicity effects of IPPP on zebrafish embryonic development, neurobehavior, and physiological and transcriptomic changes. The results showed that IPPP induced adverse developments such as low survival rates and hatching rates, decreased body length and eye distance, and also led to increased heart rates and embryonic malformation rates. The developmental defects mainly included typical pericardial edema, eye deformities, and a reduction in the number of newborn neurons. Mitochondrial energy metabolism disorders and apoptosis of cardiomyocytes may be responsible for heart malformation. Behavioral results showed that IPPP caused abnormal changes in swimming speed, total swimming distance and trajectory, and showed a low-dose effect. In addition, the decreased activity of neurotransmitters such as acetylcholinesterase (AchE) and dopamine (DA), and the changes in genes related to the central nervous system (CNS) and metabolism pathway may be the causes of neurodevelopmental toxicity of IPPP. Meanwhile, IPPP induced oxidative stress and apoptosis, and changed the ATPase activity of zebrafish larvae by altering nuclear factor erythroid2-related factor 2 (Nrf2) and mitochondrial signaling pathways, respectively. Transcriptome sequencing results indicated that Cytochrome P450 and drug metabolism, Energy metabolism-related pathways, Glutathione metabolism, Retinoid acid (RA) and REDOX signaling pathways were significantly enriched, and most of the genes in these pathways were up-regulated after IPPP treatment, which may be new targets for IPPP-induced neurodevelopment. In summary, the results of this study provide an important reference for a comprehensive assessment of the toxic effects and health risks of the new pollutant IPPP.

Can a Carbonated Lemon Drink Reduce Extracardiac Activity in Myocardial Perfusion Imaging?

Myocardial perfusion imaging (MPI) provides physiologic and functional information about the heart muscle and its blood flow. Extracardiac radioactivity can interfere with visualization of the inferior wall of the myocardium, leading to poor-quality images, difficulties in interpretation, and delays in routine practice. This study aimed to identify the efficiency of having the patient consume a carbonated lemon drink to minimize the extracardiac radioactivity of 99mTc-sestamibi in comparison to 99mTc-tetrofosmin during MPI. Methods: This was a retrospective study that recruited 158 patients with known or suspected coronary artery disease referred to undergo 99mTc-sestamibi or 99mTc-tetrofosmin rest/stress single-day MPI. The patients were divided into 2 groups of mixed sexes and different ages. The first group comprised 78 patients injected with 99mTc-sestamibi, and the second group comprised 80 patients injected with 99mTc-tetrofosmin. For both groups, the patients drank 30 mL of fresh lemon juice diluted with 150 mL of soda water, and then we gave the patients about 100 mL of straight soda water, before imaging for both the rest and the stress phases. Results: Generally, in both groups, the 99mTc-tetrofosmin produced a good-quality image in comparison with the 99mTc-sestamibi. The mean rank of the total score for 99mTc-tetrofosmin (62.75) was less than that for 99mTc-sestamibi (96.68), and this difference was highly statistically significant (P = 0.000). There were statistically significant differences in the ratios and mean ranks for both groups in favor of 99mTc-tetrofosmin in patients having coronary artery disease. Conclusion: The use of a carbonated lemon drink minimizes extracardiac activity from both 99mTc-labeled MPI radiopharmaceuticals. This finding was more statistically significant for 99mTc-tetrofosmin MPI, providing better image quality and earlier imaging in both the rest and the stress phases because of faster hepatobiliary clearance.

Photocatalytic degradation of organophosphorus flame retardants in aqueous solutions: a review and future prospects.

The widespread use of organophosphorus flame retardants (OPFRs) in industrial and household products increases the risk of their environmental exposure, posing a serious threat to ecosystems and human health. Photocatalytic technology has been widely used in wastewater treatment due to its high efficiency, mild reaction conditions, and robustness. This review summarizes the current status of research on photocatalytic degradation of OPFRs, focusing on the effect of different types of catalysts on the degradation efficiency, the effects of pH, and co-existing inorganic and organic ions. And pH and co-existing inorganic mainly affect the active oxygen and the active surface sites of the catalyst. In addition, toxicological calculations of the intermediates of the degradation pathway using T.E.S.T. and ECOSAR showed that photocatalysis could effectively reduce the toxicity of OPFRs. Development of new photocatalytic materials, in-depth study of the degradation mechanism of different catalysts and flame retardants, and attention to practical applications and toxicity issues can be the development direction of future research.

The ameliorative effect of Naringenin on fenamiphos induced hepatotoxicity and nephrotoxicity in a rat model: Oxidative stress, inflammatory markers, biochemical, histopathological, immunohistochemical and electron microscopy study.

Fenamiphos (FNP) is an organophospate pesticide that causes many potential toxicities in non-target organisms. Naringenin (NAR) has protective properties against oxidative stress. In this study, FNP (0.76 mg/kg bw) toxicity and the effect of NAR (50 mg/kg bw) on the liver and kidney of rats were investigated via biochemical, oxidative stress, immunohistochemical, cytopathological and histopathologically. As a result of biochemical studies, FNP caused oxidative stress in tissues with a change in total antioxidant/oxidant status. After treatment with FNP, hepatic and renal levels of AChE were significantly reduced while 8-OHdG and IL-17 levels, caspase-3 and TNF-α immunoreactivity increased compared to the control group. It also changed in serum biochemical markers such as ALT, AST, BUN, creatinine. Exposure to FNP significantly induced cytopathological, histopathological and immunohistochemical changes through tissue damage. NAR treatment restored biochemical parameters, renal/hepatic AChE, ultrastructural, histopathological and immunohistochemical changes modulated and blocked the increasing effect of FNP on tissues caspase-3 and TNF-α expressions, 8-OHdG and IL-17 levels. In electron microscopy studies, swelling was observed in the mitochondria of the cells in both tissues of the FNP-treated rats, while less ultrastructural changes in the FNP plus NAR-treated rats.

Cytotoxicity evaluation of organophosphorus flame retardants using electrochemical biosensors and elucidation of associated toxic mechanisms.

In recent years, organophosphorus flame retardants (OPFRs) have been widely used as substitutes for brominated flame retardants with excellent properties, and their initial toxicological effects on the water ecosystem and human health have gradually emerged. However, to date, research on the cytotoxicity and health risks of OPFRs is still limited. Therefore, this study aims to systematically explore the cytotoxic effects and toxic mechanisms of OPFRs on cells. Human liver cancer (HepG2) cells were adopted as an ideal model for toxicity evaluation due to their rapid growth and metabolism. This study proposes a sensitive electrochemical cell-based sensor constructed on a graphitized multi-walled carbon nanotube/ionic liquid/gold nanoparticle-modified electrode. The sensor was used to detect the cytotoxicity of tri(2-butylxyethyl) phosphate (TBEP), tributyl phosphate (TnBP), triphenyl phosphate (TPhP), tri(1,3-dichloro-2-propyl) phosphate (TDCIPP), tri(2-chloropropyl) phosphate (TCPP) and tri(2-chloroethyl) phosphate (TCEP) in the liquid medium, providing insight into their toxicity in water environments. The half-maximal inhibitory concentration (IC50) of TBEP, TnBP, TPhP, TDCIPP, TCPP and TCEP on HepG2 cells were 179.4, 194.9, 219.8, 339.4, 511.8 and 859.0 µM, respectively. Additionally, the cytotoxic mechanism of six OPFRs was discussed from the perspective of oxidative stress and apoptosis, and four indexes were correlated with toxicity. Furthermore, transcriptome sequencing was conducted, followed by a thorough analysis of the obtained sequencing results. This analysis demonstrated a significant enrichment of the p53 and PPAR pathways, both of which are closely associated with oxidative stress and apoptosis. This study presents a simplified and efficient technique for conducting in vitro toxicity studies on organophosphorus flame retardants in a water environment. Moreover, it establishes a scientific foundation for further investigation into the mechanisms of cytotoxicity associated with these compounds.

Optimizing Archaeal Lipid Biosynthesis in Escherichia coli.

Membrane lipid chemistry is remarkably different in archaea compared with bacteria and eukaryotes. In the evolutionary context, this is also termed the lipid divide and is reflected by distinct biosynthetic pathways. Contemporary organisms have almost without exception only one type of membrane lipid. During early membrane evolution, mixed membrane stages likely occurred, and it was hypothesized that the instability of such mixtures was the driving force for the lipid divide. To examine the compatibility between archaeal and bacterial lipids, the bacterium Escherichia coli has been engineered to contain both types of lipids with varying success. Only limited production of archaeal lipid archaetidylethanolamine was achieved. Here, we substantially increased its production in E. coli by overexpression of an archaeal phosphatidylserine synthase needed for ethanolamine headgroup attachment. Furthermore, we introduced a synthetic isoprenoid utilization pathway to increase the supply of isopentenyl-diphosphate and dimethylallyl diphosphate. This improved archaeal lipid production substantially. The archaeal phospholipids also served as a substrate for the E. coli cardiolipin synthase, resulting in archaeal and novel hybrid archaeal/bacterial cardiolipin species not seen in living organisms before. Growth of the E. coli strain with the mixed membrane shows an enhanced sensitivity to the inhibitor of fatty acid biosynthesis, cerulenin, indicating a critical dependence of the engineered E. coli strain on its native phospholipids.

MitoQ relieves mitochondrial dysfunction in UVA and cigarette smoke-induced Fuchs endothelial corneal dystrophy.

Fuchs endothelial corneal dystrophy (FECD), a degenerative corneal condition, is characterized by the droplet-like accumulation of the extracellular matrix, known as guttae and progressive loss of corneal endothelial cells ultimately leading to visual distortion and glare. FECD can be influenced by environmental stressors and genetic conditions. However, the role of mitochondrial dysfunction for advancing FECD pathogenesis is not yet fully studied. Therefore, in the present study we sought to determine whether a combination of environmental stressors (ultraviolet-A (UVA) light and cigarette smoke condensate (CSC)) can induce mitochondrial dysfunction leading to FECD. We also investigated if MitoQ, a water-soluble antioxidant, can target mitochondrial dysfunction induced by UVA and CSC in human corneal endothelial cells mitigating FECD pathogenesis. We modeled the FECD by increasing exogenous oxidative stress with CSC (0.2%), UVA (25J/cm2) and a combination of UVA + CSC and performed a temporal analysis of their cellular and mitochondrial effects on HCEnC-21T immortalized cells in vitro before and after MitoQ (0.05 µM) treatment. Interestingly, we observed that a combination of UVA + CSC exposure increased mitochondrial ROS and fragmentation leading to a lower mitochondrial membrane potential and increased levels of cytochrome c release leading to apoptosis and cell death. MitoQ intervention successfully mitigated these effects and restored cell viability. The UVA + CSC model could be used to study stress induced mitochondrial dysfunction. Additionally, MitoQ can serve as a viable antioxidant in attenuating mitochondrial dysfunction, underscoring its potential as a molecular-focused treatment approach to combat FECD pathogenesis.

Mitochondria-targeting nanozyme for catalytical therapy and radiotherapy with activation of cGAS-STING.

BACKGROUND: Overcoming radio-resistance and enhance radio-sensitivity to obtain desired therapeutic outcome plays an important role in treating cancer. METHODS: Here we constructed a versatile enzyme-like nano-radiosensitizer MDP. MDP is composed of MnCO decorated and Ru-based nanozyme with triphenylphosphine (TPP) group coordinated on the surface. RESULTS: Due to the mitochondria-targeting ability of TPP and enhanced permeability and retention effect (EPR) effect of MDP, MDP accumulated in the mitochondria of tumor cells. Therefore, quantities of reactive oxygen species were produced via multiple enzyme-like properties including peroxidase (POD) and catalase (CAT) in a tumor microenvironment mimicking status. In additional, more energy of radiation ionizing was deposed in tumor site via Compton effect and secondary electron scattering by Ru element. Impressively, it was disclosed that the nanozyme can act as a cGAS-STING agonist to provoke immune response of the system, which hereby further elevated this combined therapy. CONCLUSIONS: Collectively, we fabricated a novel nanozyme with POD and CAT mimicking properties for the combination therapy of catalytical therapy, radiotherapy as well as immune therapy to eliminate cancer.

Developmental toxicity of an emerging organophosphate ester Bis-(2-ethylhexyl)-phenyl phosphate on embryonic zebrafish: Comparison to 2-ethylhexyl diphenyl phosphate.

Bis-(2-ethylhexyl)-phenyl phosphate (BEHPP) and its structural analog, 2-ethylhexyl diphenyl phosphate (EHDPP), are widely present in the environment. However, their toxic effects, particularly developmental toxicity, remain poorly understood. In this study, we evaluated the impacts of BEHPP and EHDPP on multiple developmental endpoints in zebrafish. BEHPP did not lead to mortality and malformations of embryos within the test concentration range (0.5-4.0 µM). In contrast, EHDPP had significant lethal effects, with an LC50 of 2.44 µM, and induced malformations, notably pericardial edema (PE), with an EC50 of 1.77 µM. In addition, BEHPP induced cardiac dysfunctions in embryos to a similar degree as EHDPP. Both stroke volume and cardiac output were significantly increased at BEHPP concentrations of 1.8 nM and above and at EHDPP concentrations of 4.3 nM and above. Transcriptomic analysis further corroborated the similar disturbance at the molecular level for both substances and revealed the Key Events (KEs) in the cardiac toxic regulation, including the focal adhesions, ECM-receptor interaction, cardiac muscle contraction, and the adrenergic signaling in cardiomyocytes. Taken together, the present study provided novel insights into the adverse effects of these emerging organophosphate esters and highlighted their potential risks to embryonic development in both ecosystems and humans.

Metadynamics Study of Lipid-Mediated Antibacterial Toxin Binding to the EmrE Multiefflux Protein.

EmrE is a bacterial efflux protein in the small multidrug-resistant (SMR) family present in Escherichia coli. Due to its small size, 110 residues in each dimer subunit, it is an ideal model system to study ligand-protein-membrane interactions. Here in our work, we have calculated the free energy landscape of benzyltrimetylammonium (BTMA) and tetraphenyl phosphonium (TPP) binding to EmrE using the enhanced sampling method-multiple walker metadynamics. We estimate that the free energy of BTMA binding to EmrE is -21.2 ± 3.3 kJ/mol and for TPP is -43.6 ± 3.8 kJ/mol. BTMA passes through two metastable states to reach the binding pocket, while TPP has a more complex binding landscape with four metastable states and one main binding site. Our simulations show that the ligands interact with the membrane lipids at a distance 1 nm away from the binding site which forms a broad local minimum, consistent for both BTMA and TPP. This site can be an alternate entry point for ligands to partition from the membrane into the protein, especially for bulky and/or branched ligands. We also observed the membrane lipid and C-terminal 110HisA form salt-bridge interactions with the helix-1 residue 22LysB. Our free energy estimates and clusters are in close agreement with experimental data and give us an atomistic view of the ligand-protein-lipid interactions. Understanding the binding pathway of these ligands can guide us in future design of ligands that can alter or halt the function of EmrE.

Effect of Mitoquinone on sperm quality of cryopreserved stallion semen.

This study aimed to investigate the effect of mitochondria-targeted antioxidants (Mitoquinone, MitoQ) on the quality of frozen-thawed stallion semen. Semen samples collected from three fertile stallions aged 10 - 13 years, were filtered, centrifuged in a skimmed milk-based extender, and diluted to a final concentration of 50 × 106 sperm/mL in freezing medium. Diluted semen was divided into five experimental groups supplemented with MitoQ at concentrations of 0 (control), 25, 50, 100, and 200 nM and then subjected to freezing after cooling and equilibration. After thawing, semen was evaluated for motility and kinetics at different time points. Sperm viability, plasma membrane, acrosome, DNA integrity, mitochondrial membrane potential, apoptosis, and intracellular reactive oxygen species (ROS) concentrations were evaluated. The results revealed that MitoQ at concentrations of 25, 50, and 100 nM improved (P< 0.01) the total sperm motility after 30 minutes of incubation. In addition, 25 nM MitoQ improved the sperm amplitude of lateral head displacement values (P< 0.01) after 30 minutes of incubation. Conversely, negative effects on sperm motility, kinetics, and viability were observed with the highest tested concentration of MitoQ (200 nM). The various concentrations of MitoQ did not affect the plasma membrane, acrosome, and DNA integrity, or the mitochondrial membrane potential and intracellular ROS concentrations. In conclusion, supplementation of MitoQ during cryopreservation, had a mild positive effect on sperm motility and kinetics especially at a concentration of 25 nM, while the highest concentration (200nM) has a detrimental effect on motility and viability parameters of frozen-thawed stallion sperm.