RESUMEN
There is growing concern that some managed and wild insect pollinator populations are in decline, potentially threatening biodiversity and sustainable food production on a global scale. In recent years, there has been increasing evidence that sub-lethal exposure to neurotoxic, neonicotinoid pesticides can negatively affect pollinator immunocompetence and could amplify the effects of diseases, likely contributing to pollinator declines. However, a direct pathway connecting neonicotinoids and immune functions remains elusive. In this study we show that haemocytes and non-neural tissues of the honeybee Apis mellifera express the building blocks of the nicotinic acetylcholine receptors that are the target of neonicotinoids. In addition, we demonstrate that the haemocytes, which form the cellular arm of the innate immune system, actively express choline acetyltransferase, a key enzyme necessary to synthesize acetylcholine. In a last step, we show that the expression of this key enzyme is affected by field-realistic doses of clothianidin, a widely used neonicotinoid. These results support a potential mechanistic framework to explain the effects of sub-lethal doses of neonicotinoids on the immune function of pollinators.
Asunto(s)
Acetilcolina , Guanidinas , Hemocitos , Insecticidas , Neonicotinoides , Animales , Abejas/efectos de los fármacos , Abejas/inmunología , Insecticidas/toxicidad , Neonicotinoides/toxicidad , Acetilcolina/metabolismo , Hemocitos/efectos de los fármacos , Hemocitos/inmunología , Hemocitos/metabolismo , Guanidinas/toxicidad , Tiazoles , Receptores Nicotínicos/metabolismo , Receptores Nicotínicos/efectos de los fármacos , Colina O-Acetiltransferasa/metabolismoRESUMEN
The widespread application of neonicotinoid insecticides (NNIs) has attracted widespread attention to their potential ecotoxicological effects. In this study, we systematically evaluated the toxic effects of thiamethoxam (TMX) and its metabolite clothianidin (CLO) on earthworms (Eisenia fetida). Specifically, the antioxidant system responses and endogenous metabolite metabolism responses in earthworms were analyzed in the temporal dimension after 7, 14, 21 and 28 days of exposure to TMX and CLO. The results found that TMX and CLO could inhibit the growth phenotype of earthworms and cause significant changes in antioxidant system related indicators. More importantly, we found that TMX and CLO could cause significant changes in the metabolic profiles of earthworms through NMR-based metabolomics. From the changes in endogenous metabolites, the toxicity effects of TMX on earthworms gradually increases with prolonged exposure time. Differently, the toxicity effects of CLO on earthworms is significantly higher than that of TMX in the early stages of exposure. Meanwhile, these impacts will not weaken with prolonged exposure time. Furthermore, the results of KEGG enrichment pathway analysis indicated that TMX and CLO could significantly interfere with energy homeostasis, redox homeostasis, osmotic regulation, amino acid metabolism and protein synthesis in earthworms. These findings further deepen our understanding of the ecotoxicological effects of NNIs on soil organism.
Asunto(s)
Guanidinas , Insecticidas , Neonicotinoides , Oligoquetos , Tiametoxam , Tiazoles , Oligoquetos/efectos de los fármacos , Oligoquetos/metabolismo , Animales , Tiametoxam/toxicidad , Neonicotinoides/toxicidad , Tiazoles/toxicidad , Guanidinas/toxicidad , Insecticidas/toxicidad , Nitrocompuestos/toxicidad , Oxazinas/toxicidad , Antioxidantes/metabolismo , MetabolómicaRESUMEN
In samples of harmful algal blooms (HABs), seawater can contain a high abundance of microorganisms and elemental ions. Along with the hardness of the walls of key HAB dinoflagellates such as Prorocentrum triestinum, this makes RNA extraction very difficult. These components interfere with RNA isolation, causing its degradation, in addition to the complex seawater properties of HABs that could hinder RNA isolation for effective RNA sequencing and transcriptome profiling. In this study, an RNA isolation technique was established through the modification of the Trizol method by applying the Micropestle System on cell pellets of P. triestinum frozen at -20 °C, obtained from 400 mL of culture with a total of 107 cells/mL. The results of the modified Trizol protocol generated quality RNA samples for transcriptomics sequencing, as determined by their measurement in Analyzer Agilent 4150.
Asunto(s)
Dinoflagelados , Dinoflagelados/genética , ARN/aislamiento & purificación , ARN/genética , Guanidinas/química , Análisis de Secuencia de ARN/métodos , Floraciones de Algas Nocivas , Perfilación de la Expresión Génica/métodos , Transcriptoma , Nucleótidos/genética , Nucleótidos/aislamiento & purificación , Agua de Mar , FenolesRESUMEN
Neonicotinoid pesticides are a relatively new class of pesticides that have garnered significant attention owing to their potential ecological risks to nontarget organisms. A method combining solid phase extraction with liquid chromatography-tandem mass spectrometry (SPE-LC-MS/MS) was developed for the rapid and accurate detection of eight neonicotinoid pesticides (dinotefuran, E-nitenpyram, thiamethoxam, clothianidin, imidacloprid, imidaclothiz, acetamiprid, and thiacloprid) in wastewater. The chromatographic mobile phase and MS parameters were selected, and a single-factor method was used to determine the optimal column type, extraction volume, sample loading speed, and pH for SPE. The optimal parameters were as follows: column type, HLB column (500 mg/6 mL); sample extraction volume, 500 mL; sample loading speed, 10 mL/min; and sample pH, 6-8. The matrix effects of the wastewater samples were reduced by optimizing the chromatographic gradient-elution program, examining the dilution factor of the samples, and using the isotope internal standard calibration method. Prior to analysis, the wastewater samples were diluted 5-fold with ultrapure water for pretreatment. Subsequently, 2 mmol/L ammonium acetate aqueous solution containing 0.1% (v/v) formic acid and methanol was used as mobile phases for gradient elution on a ZORBAX Eclipse Plus C18 column (100 mm×2.1 mm, 1.8 µm). The samples were quantified using positive-ion multiple reaction monitoring (MRM) mode for 10 min. Imidacloprid-d4 was used as the isotope internal standard. The SPE process was further optimized by applying response surface methodology to select the type and mass of rinsing and elution solvents. The optimal pretreatment of the SPE column included rinsing with 10% methanol aqueous solution and elution with methanol-acetonitrile (1â¶1, v/v) mixture (7 mL). The eight neonicotinoid pesticides showed satisfactory linearity within the relevant range, with linear correlation coefficients (r) all greater than 0.9990. The method detection limits (MDLs) ranged from 0.2 to 1.2 ng/L, and the method quantification limits (MQLs) ranged from 0.8 to 4.8 ng/L. The average recoveries of the eight neonicotinoid pesticides were in the range of 82.6%-94.2% at three spiked levels, with relative standard deviations (RSDs) ranging from 3.9% to 9.4%. Finally, the optimized method was successfully applied to analyze wastewater samples collected from four sewage treatment plants. The results indicated that the eight neonicotinoid pesticides could be generally detected at concentrations ranging from not detected (ND) to 256 ng/L. The developed method has a low MDL and high accuracy, rendering it a suitable choice for the trace detection of the eight neonicotinoid pesticides in wastewater when compared with other similar methods. The proposed method can be utilized to monitor the environmental impact and assess the potential risks of neonicotinoid pesticides in wastewater, thus promoting the protection of nontarget organisms and the sustainable use of these pesticides in agriculture.
Asunto(s)
Neonicotinoides , Nitrocompuestos , Extracción en Fase Sólida , Espectrometría de Masas en Tándem , Aguas Residuales , Contaminantes Químicos del Agua , Espectrometría de Masas en Tándem/métodos , Extracción en Fase Sólida/métodos , Aguas Residuales/química , Aguas Residuales/análisis , Neonicotinoides/análisis , Contaminantes Químicos del Agua/análisis , Cromatografía Liquida/métodos , Nitrocompuestos/análisis , Tiametoxam/análisis , Guanidinas/análisis , Tiazoles/análisis , Plaguicidas/análisis , Tiazinas/análisis , Oxazinas/análisisRESUMEN
The number of individuals with underlying medical conditions has been increasing steadily. These individuals are relatively vulnerable to harmful external factors. But it has not been proven that the effects of hazardous chemicals may differ depending on their physicochemical properties. This study determines the toxic effects of two chemicals with high indoor exposure risk and different physicochemical properties on an underlying disease model. A pulmonary arterial hypertension (PAH) model was constructed by a single subcutaneous injection of monocrotaline (MCT; 60â¯mg/kg) into Sprague-Dawley rats. After three weeks, formaldehyde (FA; 2.5â¯mg/kg) and polyhexamethylene guanidine (PHMG; 0.05â¯mg/kg) were administered once via intratracheal instillation, and rats were necropsied one week later. Exposure to FA and PHMG affected organ weight and the Fulton and toxicity indices in rats induced with PAH. FA promoted bronchial injury and aggravated PAH, while PHMG only induced alveolar injury. Additionally, the differentially expressed genes were altered following exposure to FA and PHMG, as were the associated diseases (cardiovascular disease and pulmonary fibrosis, respectively). In conclusion, inhaled chemicals with different physicochemical properties can cause damage to organs, such as the lungs and heart, and can aggravate underlying diseases. This study elucidates indoor inhaled exposure-induced toxicities and alerts patients with pre-existing diseases to the harmful chemicals.
Asunto(s)
Modelos Animales de Enfermedad , Formaldehído , Lesión Pulmonar , Ratas Sprague-Dawley , Animales , Ratas , Masculino , Lesión Pulmonar/inducido químicamente , Lesión Pulmonar/patología , Formaldehído/toxicidad , Guanidinas/toxicidad , Monocrotalina/toxicidad , Exposición por Inhalación , Pulmón/efectos de los fármacos , Pulmón/patología , Hipertensión Arterial Pulmonar/inducido químicamente , Sustancias Peligrosas/toxicidadRESUMEN
Diaphorina citri is a serious citrus pest. Dinotefuran is highly insecticidal against D. citri. To analyze the sublethal effects of dinotefuran on D. citri adults, an indoor toxicity test was performed, which revealed that the lethal concentration 50 (LC50) values were 4.23 and 0.50 µg/mL for 24 and 48 h treatments, respectively. RNA-Seq led to the identification of 71 and 231 differentially expressed genes (DEGs) after dinotefuran treatments with LC20 and LC50 doses, respectively. Many of the DEGs are significantly enriched in the apoptosis pathway. Dinotefuran-induced apoptosis in the gut cells was confirmed through independent assays of 4',6-diamidino-2-phenylindole (DAPI) and TdT-mediated dUTP nick end labeling (TUNEL) staining. Increased levels of reactive oxygen species (ROS) and a loss of mitochondrial membrane potential were observed. Four caspase genes were identified, and dinotefuran treatments resulted in increased mRNA levels of DcCasp1 and DcCasp3a. These findings shed light on the sublethal effects of dinotefuran on D. citri.
Asunto(s)
Apoptosis , Guanidinas , Proteínas de Insectos , Insecticidas , Mitocondrias , Neonicotinoides , Nitrocompuestos , Apoptosis/efectos de los fármacos , Animales , Neonicotinoides/toxicidad , Nitrocompuestos/toxicidad , Nitrocompuestos/farmacología , Insecticidas/toxicidad , Insecticidas/farmacología , Mitocondrias/efectos de los fármacos , Mitocondrias/metabolismo , Mitocondrias/genética , Proteínas de Insectos/genética , Proteínas de Insectos/metabolismo , Guanidinas/toxicidad , Guanidinas/farmacología , Hemípteros/efectos de los fármacos , Hemípteros/genética , Especies Reactivas de Oxígeno/metabolismo , Tracto Gastrointestinal/efectos de los fármacos , Tracto Gastrointestinal/metabolismo , Potencial de la Membrana Mitocondrial/efectos de los fármacosRESUMEN
AIMS: Advanced glycation end-products (AGEs) are implicated in the age-related decline of renal function, exacerbated by conditions, such as hyperglycemia and oxidative stress. The accumulation of AGEs in the kidneys contributes to the progressive decline in renal function observed with aging. However, the precise role and mechanisms of AGEs in the age-related decline of renal function remain unclear. In this study, we investigated the impact and potential mechanisms of AGEs on aging kidneys in naturally aging mice. MATERIALS AND METHODS: Male C57BL/6 mice were divided into three groups: 6-, 57-, and 107-week-old. First, the 6- and 107-week-old mice were euthanized. The remaining mice were divided into young (6 weeks) and old (57 weeks) groups. The 57-week-old mice were orally administered aminoguanidine (100 mg/kg/day), an AGEs inhibitor, or vehicle for 13 weeks, resulting in a final age of 70 weeks. The serum and kidney tissues were collected for biochemical measurement, histological examination, immunohistochemistry staining, and immunoblotting analysis. KEY FINDINGS: Our findings revealed a notable accumulation of AGEs in both serum and kidney tissue specimens and renal dysfunction in naturally aging mice. Aminoguanidine not only reversed AGEs accumulation but also ameliorated renal dysfunction. Additionally, aminoguanidine attenuated the upregulation of fibrosis markers (phosphorylated p38/α-SMA and C/EBP homologous protein, CHOP), senescence markers (p53 and p21), and oxidative stress marker (4-HNE) in the aging kidneys. SIGNIFICANCE: These findings underscore the critical role of AGEs in age-related renal dysfunction and highlight the therapeutic potential of aminoguanidine in mitigating fibrosis and senescence, offering prospective avenues for combating age-associated renal ailments.
Asunto(s)
Envejecimiento , Productos Finales de Glicación Avanzada , Guanidinas , Riñón , Ratones Endogámicos C57BL , Estrés Oxidativo , Animales , Productos Finales de Glicación Avanzada/metabolismo , Masculino , Envejecimiento/metabolismo , Ratones , Riñón/metabolismo , Riñón/patología , Estrés Oxidativo/efectos de los fármacos , Guanidinas/farmacología , Enfermedades Renales/metabolismo , Enfermedades Renales/patología , Fibrosis/metabolismoRESUMEN
OBJECTIVES: To synthesize new bakuchiol aminoguanidine derivatives and test their effect on viability and apoptosis of human triple-negative breast cancer (TNBC) cells. METHODS: Two bakuchiol derivatives 1 and 2 were obtained by formylation and Shiff base reaction of bakuchol. The structures of derivatives 1 and 2 were identified by 1H-NMR, 13C-NMR, and high-resolution electrospray ionization mass spectrometry (HR-ESI-MS) analysis. Human TNBC MDA-MB-231 cells were treated with bakuchiol and its derivatives and cell viability was measured by MTT assay. Apoptosis was detected by fluorescence microscopy and flow cytometry with Annexin V-FITC/PI staining. The expressions of apoptosis-related proteins were analyzed with Western blotting. The JC-1 and reactive oxygen species (ROS) assay kits were used to determine the effect of new bakuchiol derivatives on mitochondrial function. RESULTS: Based on spectroscopic analysis, a new bakuchiol schiff base derivative was elucidated as 2-{(E)-5-[(S, E)-3, 7-dimethyl-3-vinylocta-1, 6-dien-1-yl]-2-hydroxylbenzylidene} hydrazine-1-carboximidamide (derivative 2). Bakuchiol and its derivatives 1 and 2 all showed cytotoxic activity against the MDA-MB-231 cells. Derivative 2 exhibited the most potent cytotoxic activity to MDA-MB-231 cell with IC50 of (13.11±1.09), (6.91±1.78), and (2.23±1.32) µmol/L after 24, 48, and 72 h. It had low toxicity to normal mouse liver (AML-12) cells with IC50 of (31.23±1.58) µmol/L at 72 h. Fluorescence microscopy and flow cytometry demonstrated apoptosis in breast cancer cells after treating with derivative 2 in a concentration dependent manner. Western blotting showed that after derivative 2 treatment, the expression of apoptosis-related proteins cytochrome C, cleaving caspase-3 and Bax/Bcl-2 radio in MDA-MB-231 cells increased; in addition, apoptosis was associated with the decreased mitochondrial membrane potential and increased reactive oxygen species accumulation. CONCLUSIONS: The novel bakuchiol aminoguanidine derivative (derivative 2) is capable of inducing apoptosis in MDA-MB-231 cells, but has low toxicity to normal liver cells, suggesting that it may be used as a lead compound for an anti-TNBC agent.
Asunto(s)
Apoptosis , Guanidinas , Fenoles , Especies Reactivas de Oxígeno , Neoplasias de la Mama Triple Negativas , Humanos , Apoptosis/efectos de los fármacos , Neoplasias de la Mama Triple Negativas/patología , Neoplasias de la Mama Triple Negativas/tratamiento farmacológico , Línea Celular Tumoral , Femenino , Fenoles/farmacología , Guanidinas/farmacología , Especies Reactivas de Oxígeno/metabolismo , Supervivencia Celular/efectos de los fármacosRESUMEN
Polyhexamethylene guanidine (PHMG) is a positively charged polymer used as a disinfectant that kills microbes but can cause pulmonary fibrosis if inhaled. After the long-term risks were confirmed in South Korea, it became crucial to measure toxicity through diverse surrogate biomarkers, not only proteins, especially after these hazardous chemicals had cleared from the body. These biomarkers, identified by their biological functions rather than simple numerical calculations, effectively explained the imbalance of pulmonary surfactant caused by fibrosis from PHMG exposure. These long-term studies on children exposed to PHMG has shown that blood protein indicators, primarily related to apolipoproteins and extracellular matrix, can distinguish the degree of exposure to humidifier disinfectants (HDs). We defined the extreme gradient boosting models and computed reflection scores based on just ten selected proteins, which were also verified in adult women exposed to HD. The reflection scores successfully discriminated between the HD-exposed and unexposed groups in both children and adult females (AUROC: 0.957 and 0.974, respectively) and had a strong negative correlation with lung function indicators. Even after an average of more than 10 years, blood is still considered a meaningful specimen for assessing the impact of environmental exposure to toxic substances, with proteins providing in identifying the pathological severity of such conditions.
Asunto(s)
Aerosoles , Proteínas Sanguíneas , Guanidinas , Humanos , Guanidinas/toxicidad , Guanidinas/química , Femenino , Adulto , Proteínas Sanguíneas/análisis , Lesión Pulmonar/inducido químicamente , Biomarcadores/sangre , Desinfectantes/toxicidad , Niño , Humidificadores , Exposición por Inhalación/efectos adversosRESUMEN
The neurotoxic effects of neonicotinoids (NEOs) have been widely reported in relation to the poisoning of wild birds, yet the underlying molecular mechanism has remained elusive. This study employed Japanese quails (Coturnix japonica) and primary quail embryonic neurons as in vivo and ex vivo models, respectively, to investigate the neurotoxic effects and mechanism of thiamethoxam (TMX), a representative neonicotinoid insecticide, at environmentally relevant concentrations. Following a 28-day exposure to TMX, metabolomic analysis of quail brain revealed TMX-induced changes in glutamatergic, GABA-ergic, and dopaminergic function. Subsequent ex vivo and in silico experimentation revealed that the activation of nicotinic acetylcholine receptors and calcium signaling, induced by clothianidin (CLO), the primary metabolite of TMX, served as upstream events for the alterations in neurotransmitter synthesis, metabolism, release, and uptake. Our findings propose that the disruption of the central nervous system, caused by environmentally significant concentrations of NEOs, may account for the avian poisoning events induced by NEOs.
Asunto(s)
Coturnix , Insecticidas , Tiametoxam , Animales , Tiametoxam/toxicidad , Coturnix/metabolismo , Insecticidas/toxicidad , Sistema Nervioso Central/efectos de los fármacos , Sistema Nervioso Central/metabolismo , Neonicotinoides/toxicidad , Tiazoles/toxicidad , Encéfalo/metabolismo , Encéfalo/efectos de los fármacos , Simulación por Computador , Neuronas/efectos de los fármacos , Neuronas/metabolismo , Guanidinas/toxicidad , Oxazinas/toxicidad , Receptores Nicotínicos/metabolismoRESUMEN
Defense against intracellular acidification of breast cancer tissue depends on net acid extrusion via Na+,HCO3--cotransporter NBCn1/Slc4a7 and Na+/H+-exchanger NHE1/Slc9a1. NBCn1 is increasingly recognized as breast cancer susceptibility protein and promising therapeutic target, whereas evidence for targeting NHE1 is discordant. Currently, selective small molecule inhibitors exist against NHE1 but not NBCn1. Cellular assays-with some discrepancies-link NHE1 activity to proliferation, migration, and invasion; and disrupted NHE1 expression can reduce triple-negative breast cancer growth. Studies on human breast cancer tissue associate high NHE1 expression with reduced metastasis and-in some molecular subtypes-improved patient survival. Here, we evaluate Na+/H+-exchange and therapeutic potential of the NHE1 inhibitor cariporide/HOE-642 in murine ErbB2-driven breast cancer. Ex vivo, cariporide inhibits net acid extrusion in breast cancer tissue (IC50 = 0.18 µM) and causes small decreases in steady-state intracellular pH (pHi). In vivo, we deliver cariporide orally, by osmotic minipumps, and by intra- and peritumoral injections to address the low oral bioavailability and fast metabolism. Prolonged cariporide administration in vivo upregulates NBCn1 expression, shifts pHi regulation towards CO2/HCO3--dependent mechanisms, and shows no net effect on the growth rate of ErbB2-driven primary breast carcinomas. Cariporide also does not influence proliferation markers in breast cancer tissue. Oral, but not parenteral, cariporide elevates serum glucose by â¼1.5 mM. In conclusion, acute administration of cariporide ex vivo powerfully inhibits net acid extrusion from breast cancer tissue but lowers steady-state pHi minimally. Prolonged cariporide administration in vivo is compensated via NBCn1 and we observe no discernible effect on growth of ErbB2-driven breast carcinomas.
Asunto(s)
Neoplasias de la Mama , Proliferación Celular , Guanidinas , Receptor ErbB-2 , Intercambiador 1 de Sodio-Hidrógeno , Sulfonas , Guanidinas/farmacología , Femenino , Animales , Receptor ErbB-2/metabolismo , Receptor ErbB-2/genética , Receptor ErbB-2/antagonistas & inhibidores , Intercambiador 1 de Sodio-Hidrógeno/metabolismo , Intercambiador 1 de Sodio-Hidrógeno/antagonistas & inhibidores , Intercambiador 1 de Sodio-Hidrógeno/genética , Ratones , Humanos , Sulfonas/farmacología , Proliferación Celular/efectos de los fármacos , Neoplasias de la Mama/tratamiento farmacológico , Neoplasias de la Mama/patología , Neoplasias de la Mama/metabolismo , Neoplasias de la Mama/genética , Simportadores de Sodio-Bicarbonato/metabolismo , Simportadores de Sodio-Bicarbonato/genética , Simportadores de Sodio-Bicarbonato/antagonistas & inhibidores , Línea Celular Tumoral , Concentración de Iones de HidrógenoRESUMEN
Novel insecticides were recently introduced to counter pyrethroid resistance threats in African malaria vectors. To prolong their effectiveness, potential cross-resistance from promiscuous pyrethroid metabolic resistance mechanisms must be elucidated. Here, we demonstrate that the duplicated P450s CYP6P9a/-b, proficient pyrethroid metabolizers, reduce neonicotinoid efficacy in Anopheles funestus while enhancing the potency of chlorfenapyr. Transgenic expression of CYP6P9a/-b in Drosophila confirmed that flies expressing both genes were significantly more resistant to neonicotinoids than controls, whereas the contrasting pattern was observed for chlorfenapyr. This result was also confirmed by RNAi knockdown experiments. In vitro expression of recombinant CYP6P9a and metabolism assays established that it significantly depletes both clothianidin and chlorfenapyr, with metabolism of chlorfenapyr producing the insecticidally active intermediate metabolite tralopyril. This study highlights the risk of cross-resistance between pyrethroid and neonicotinoid and reveals that chlorfenapyr-based control interventions such as Interceptor G2 could remain efficient against some P450-based resistant mosquitoes.
Asunto(s)
Anopheles , Sistema Enzimático del Citocromo P-450 , Guanidinas , Resistencia a los Insecticidas , Insecticidas , Malaria , Neonicotinoides , Piretrinas , Tiazoles , Animales , Tiazoles/farmacología , Guanidinas/farmacología , Resistencia a los Insecticidas/genética , Anopheles/efectos de los fármacos , Anopheles/genética , Piretrinas/farmacología , Piretrinas/metabolismo , Neonicotinoides/farmacología , Insecticidas/farmacología , Sistema Enzimático del Citocromo P-450/metabolismo , Sistema Enzimático del Citocromo P-450/genética , Especificidad por Sustrato , Mosquitos Vectores/efectos de los fármacos , Mosquitos Vectores/genética , Proteínas de Insectos/metabolismo , Proteínas de Insectos/genéticaRESUMEN
D2 is a structural and cooperative domain of Thermotoga maritima Arginine Binding Protein, that possesses a remarkable conformational stability, with a denaturation temperature of 102.6°C, at pH 7.4. The addition of potassium thiocyanate causes a significant decrease in the D2 denaturation temperature. The interactions of thiocyanate ions with D2 have been studied by means of isothermal titration calorimetry measurements and molecular dynamics simulations. It emerged that: (a) 20-30 thiocyanate ions interact with the D2 surface and are present in its first solvation shell; (b) each of them makes several contacts with protein groups, both polar and nonpolar ones. The addition of guanidinium thiocyanate causes a marked destabilization of the D2 native state, because both the ions are denaturing agents. However, on adding to the solution containing D2 and guanidinium thiocyanate a stabilizing agent, such as TMAO, sucrose or sodium sulfate, a significant increase in denaturation temperature occurs. The present results confirm that counteraction is a general phenomenon for globular proteins.
Asunto(s)
Simulación de Dinámica Molecular , Estabilidad Proteica , Thermotoga maritima , Tiocianatos , Tiocianatos/química , Thermotoga maritima/química , Proteínas Bacterianas/química , Proteínas Bacterianas/metabolismo , Desnaturalización Proteica/efectos de los fármacos , Sulfatos/química , Metilaminas/química , Dominios Proteicos , Guanidinas/químicaRESUMEN
Osteonecrosis of the jaw (ONJ) is a relatively rare side effect after prolonged use of bisphosphonates, which are drugs used to treat bone resorption in osteoporosis and certain cancers. This study introduces a novel ONJ model in rats by combining exposure to bisphosphonates, oral surgery, and bacterial inoculation. Potential ONJ preventive effects of polyguanidine (GuaDex) or antibiotics were evaluated. The study consisted of twenty-four male Wistar rats were divided into four groups. Groups 1 to 3 were given weekly doses of i.v. Zoledronic acid (ZA), four weeks before and two weeks after an osteotomy procedure on their left mandibular first molar. Group 4 was a negative control. Streptococcus gordonii bacteria were introduced into the osteotomy pulp chamber and via the food for seven days. On day eight, the rats were given different treatments. Group 1 was given a GuaDex injection into the osteotomy socket, Group 2 was given an intramuscular (i.m.) injection of clindamycin, Group 3 (positive control) was given an i.m. injection of saline, and Group 4 was given an i.m. injection of saline. Blood samples were taken two weeks after the osteotomy procedure, after which the rats were euthanized. Bone healing, bone mineral density, histology, and blood status were analyzed. The results showed that Group 1 (GuaDex) had no ONJ, extensive ongoing bone regeneration, active healing activity, vascularization, and no presence of bacteria. Group 2 (clindamycin) showed early stages of ONJ, avascular areas, and bacteria. Group 3 showed stages of ONJ, inflammatory infiltrates, defective healing, and bacterial presence, and Group 4 had normal healing activity and no bacterial presence. Conclusion: ZA treatment and bacterial inoculation after tooth extraction inhibited bone remodeling/healing and induced ONJ characteristic lesions in the rats. Only GuaDex apparently prevented ONJ development, stimulated bone remodeling, and provided an antimicrobial effect.
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Osteonecrosis de los Maxilares Asociada a Difosfonatos , Ratas Wistar , Animales , Masculino , Osteonecrosis de los Maxilares Asociada a Difosfonatos/prevención & control , Osteonecrosis de los Maxilares Asociada a Difosfonatos/patología , Ratas , Difosfonatos/farmacología , Difosfonatos/efectos adversos , Guanidinas/farmacología , Guanidinas/uso terapéuticoRESUMEN
Inhaling polyhexamethylene guanidine (PHMG) aerosol, a broad-spectrum disinfectant, can lead to severe pulmonary fibrosis. Ferroptosis, a form of programmed cell death triggered by iron-dependent lipid peroxidation, is believed to play a role in the chemical-induced pulmonary injury. This study aimed to investigate the mechanism of ferroptosis in the progression of PHMG-induced pulmonary fibrosis. C57BL/6â¯J mice and the alveolar type II cell line MLE-12 were used to evaluate the toxicity of PHMG in vivo and in vitro, respectively. The findings indicated that iron deposition was observed in PHMG induced pulmonary fibrosis mouse model and ferroptosis related genes have changed after 8 weeks PHMG exposure. Additionally, there were disturbances in the antioxidant system and mitochondrial damage in MLE-12 cells following a 12-hour treatment with PHMG. Furthermore, the study observed an increase in lipid peroxidation and a decrease in GPX4 activity in MLE-12 cells after exposure to PHMG. Moreover, pretreatment with the ferroptosis inhibitors Ferrostatin-1 (Fer-1) and Liproxstatin-1 (Lip-1) not only restored the antioxidant system and GPX4 activity but also mitigated lipid peroxidation. Current data exhibit the role of ferroptosis pathway in PHMG-induced pulmonary fibrosis and provide a potential target for future treatment.
Asunto(s)
Ferroptosis , Guanidinas , Peroxidación de Lípido , Ratones Endogámicos C57BL , Fosfolípido Hidroperóxido Glutatión Peroxidasa , Fibrosis Pulmonar , Animales , Ferroptosis/efectos de los fármacos , Fibrosis Pulmonar/inducido químicamente , Fibrosis Pulmonar/patología , Ratones , Peroxidación de Lípido/efectos de los fármacos , Línea Celular , Guanidinas/toxicidad , Guanidinas/farmacología , Masculino , Células Epiteliales Alveolares/efectos de los fármacos , Células Epiteliales Alveolares/patología , Ciclohexilaminas/farmacología , Fenilendiaminas , Quinoxalinas , Compuestos de EspiroRESUMEN
Data from prior research indicate the prepupal stage of the monarch butterfly life cycle is more sensitive to clothianidin exposure than the larval stage. A set of experiments was conducted to determine if the dietary clothianidin exposures that cause prepupal mortality are environmentally relevant. Monarch larvae were raised from egg to pupae on clothianidin-contaminated swamp milkweed plants (Asclepias incarnata). Larval growth as well as larval and prepupal survival were monitored throughout the experiments, in which the exposures ranged from 1.4 to 2793.1 ng/g leaf. Exposures of 5.4 to 46.9 ng/g leaf resulted primarily in prepupal mortality, whereas higher exposures of 1042.4 to 2793.1 ng/g leaf resulted exclusively in larval mortality, indicating the prepupal stage is more sensitive to clothianidin exposure than the larval stage. A median lethal concentration and a 10% lethal concentration of 37 and 6 ng/g leaf, respectively, were estimated for prepupal mortality. Both effect concentrations are within the range of clothianidin concentrations reported in leaves collected from wild milkweed plants, indicating prepupal mortality is an environmentally relevant effect. Environ Toxicol Chem 2024;43:2039-2044. © 2024 The Authors. Environmental Toxicology and Chemistry published by Wiley Periodicals LLC on behalf of SETAC.
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Mariposas Diurnas , Guanidinas , Insecticidas , Larva , Neonicotinoides , Tiazoles , Animales , Mariposas Diurnas/efectos de los fármacos , Mariposas Diurnas/crecimiento & desarrollo , Tiazoles/toxicidad , Neonicotinoides/toxicidad , Guanidinas/toxicidad , Larva/efectos de los fármacos , Larva/crecimiento & desarrollo , Insecticidas/toxicidad , Asclepias , Hojas de la Planta/química , Pupa/efectos de los fármacos , Pupa/crecimiento & desarrollo , Exposición DietéticaRESUMEN
Clothianidin, classified as a second-generation neonicotinoid, has achieved extensive application due to its high efficacy against insect pests. This broad-spectrum usage has resulted in its frequent detection in environmental surveys. CYP2C19 and CYP3A4 are crucial for converting clothianidin to desmethyl-clothianidin (dm-clothianidin). The expression of these CYP450s can be significantly influenced by genetic polymorphisms. The objective of our research was to examine the catalytic effects of 27 CYP3A4 variants and 31 CYP2C19 variants on the metabolism of clothianidin within recombinant insect microsomes. These variants were assessed through a well-established incubation procedure. In addition, the concentration of its metabolite dm-clothianidin was quantified by employing an ultra performance liquid chromatography tandem mass spectrometry (UPLC-MS/MS). Lastly, the kinetic parameters of these CYP3A4 and CYP2C19 variants were calculated by applying Michaelis-Menten kinetic analysis to fit the data. The observed changes in enzyme activity were related to the metabolic transformation of clothianidin to dm-clothianidin. In the CYP2C19 metabolic pathway, one variant (CYP2C19.23) showed no notable change in intrinsic clearance (CLint), four variants (CYP2C19.29, .30, .31 and L16F) demonstrated a marked increase in CLint (110.86-183.46 %), and the remaining 25 variants exhibited a considerable decrease in CLint (26.38-89.79 %), with a maximum decrease of 73.62 % (CYP2C19.6). In the CYP3A4 metabolic pathway, 26 variants demonstrated significantly reduced CLint (10.54-52.52 %), with a maximum decrease of 89.46 % (CYP3A4.20). Our results suggested that most variants of CYP3A4 and CYP2C19 significantly altered the enzymatic activities associated with clothianidin metabolism to various degrees. This study provides new insights into assessing the metabolic behavior of pesticides and delivers crucial data that can guide clinical detoxification strategies.
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Citocromo P-450 CYP2C19 , Citocromo P-450 CYP3A , Guanidinas , Neonicotinoides , Polimorfismo Genético , Tiazoles , Citocromo P-450 CYP2C19/genética , Citocromo P-450 CYP2C19/metabolismo , Citocromo P-450 CYP3A/genética , Citocromo P-450 CYP3A/metabolismo , Tiazoles/metabolismo , Guanidinas/metabolismo , Neonicotinoides/metabolismo , Humanos , Animales , Cinética , Espectrometría de Masas en Tándem , Insecticidas/metabolismo , Microsomas/metabolismoRESUMEN
Mycobacterium tuberculosis is an infectious pathogen that requires biosafety level-3 laboratory for handling. The risk of transmission is high to laboratory staff, and to manage the organism safely, it is necessary to construct high containment laboratory facilities at great expense. This limits the application of tuberculosis diagnostics to areas where there is insufficient capital to invest in laboratory infrastructure. In this method, we describe a process of inactivating sputum samples by either heat or guanidine thiocyanate (GTC) that renders them safe without affecting the quantification of viable bacteria. This method eliminates the need for level 3 containment laboratory for the tuberculosis molecular bacterial load assay (TB-MBLA) and is applicable in low- and middle-income countries.
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Contención de Riesgos Biológicos , Mycobacterium tuberculosis , Esputo , Tiocianatos , Mycobacterium tuberculosis/aislamiento & purificación , Humanos , Contención de Riesgos Biológicos/métodos , Esputo/microbiología , Carga Bacteriana/métodos , Tuberculosis/diagnóstico , Tuberculosis/microbiología , Tuberculosis/prevención & control , Guanidinas , Calor , Viabilidad MicrobianaRESUMEN
With the spread of resistance to long-established insecticides targeting Anopheles malaria vectors, understanding the actions of compounds newly identified for vector control is essential. With new commercial vector-control products containing neonicotinoids under development, we investigate the actions of 6 neonicotinoids (imidacloprid, thiacloprid, clothianidin, dinotefuran, nitenpyram and acetamiprid) on 13 Anopheles gambiae nicotinic acetylcholine receptor (nAChR) subtypes produced by expression of combinations of the Agα1, Agα2, Agα3, Agα8 and Agß1 subunits in Xenopus laevis oocytes, the Drosophila melanogaster orthologues of which we have previously shown to be important in neonicotinoid actions. The presence of the Agα2 subunit reduces neonicotinoid affinity for the mosquito nAChRs, whereas the Agα3 subunit increases it. Crystal structures of the acetylcholine binding protein (AChBP), an established surrogate for the ligand-binding domain, with dinotefuran bound, shows a unique target site interaction through hydrogen bond formation and CH-N interaction at the tetrahydrofuran ring. This is of interest as dinotefuran is also under trial as the toxic element in baited traps. Multiple regression analyses show a correlation between the efficacy of neonicotinoids for the Agα1/Agα2/Agα8/Agß1 nAChR, their hydrophobicity and their rate of knockdown of adult female An. gambiae, providing new insights into neonicotinoid features important for malaria vector control.
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Anopheles , Guanidinas , Insecticidas , Mosquitos Vectores , Neonicotinoides , Nitrocompuestos , Receptores Nicotínicos , Animales , Anopheles/metabolismo , Anopheles/genética , Anopheles/efectos de los fármacos , Neonicotinoides/farmacología , Receptores Nicotínicos/metabolismo , Receptores Nicotínicos/genética , Receptores Nicotínicos/química , Insecticidas/farmacología , Insecticidas/química , Nitrocompuestos/farmacología , Nitrocompuestos/química , Guanidinas/farmacología , Mosquitos Vectores/efectos de los fármacos , Mosquitos Vectores/genética , Xenopus laevis , Ligandos , Piridinas/farmacología , Malaria/transmisión , Malaria/parasitología , Tiazoles/farmacología , Tiazoles/química , Tiazoles/metabolismo , Tiazinas/farmacología , Tiazinas/química , Oocitos/metabolismo , Oocitos/efectos de los fármacos , Femenino , Proteínas de Insectos/metabolismo , Proteínas de Insectos/genética , Proteínas de Insectos/química , Imidazoles/farmacología , Imidazoles/químicaRESUMEN
BACKGROUND: Camostat mesylate, an oral serine protease inhibitor, is a powerful TMPRSS2 inhibitor and has been reported as a possible antiviral treatment against COVID-19. Therefore, we aim to assess the safety and efficacy of camostat mesylate for COVID-19 treatment. METHODS: A systematic review and meta-analysis synthesizing randomized controlled trials from PubMed, Scopus, Embase, Cochrane, Web of Science, clinical trials.gov, and medrxiv until June 2023. The outcomes were pooled using Mean difference (MD) for continuous outcomes and risk ratio (RR) for dichotomous outcomes. The protocol is registered in PROSPERO with ID CRD42023439633. RESULTS: Nine RCTs, including 1,623 patients, were included in this analysis. There was no difference between camostat mesylate and placebo in producing negative PCR test results at 1-7 days (RR: 0.76, 95% CI: [0.54, 1.06] P = 0.1), 8-14 days (RR: 1.02, 95% CI: [0.84, 1.23] P = 0.87), or 15-21 days (RR: 0.99, 95% CI: [0.82, 1.19] P = 0.90); clinical resolution of symptoms at 1-7 days (RR: 0.94 (95% CI: 0.58, 1.53) P = 0.81), 8-14 days (RR: 0.91, 95% CI: [0.74, 1.11] P = 0.33, ), or 15-21 days (RR: 0.77, 95% CI: [0.40, 1.51] P = 0.45); and time to symptom improvement (MD:-0.38 weeks (95% CI: [-1.42, 0.66] P = 0.47, I2 = 85%). CONCLUSION: Camostat mesylate did not improve clinical outcomes in patients with COVID-19, compared to placebo.