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Toxicol Res (Camb) ; 10(4): 911-927, 2021 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-34484683


Cholestasis is a severe clinical complication that severely damages the liver. Kidneys are also the most affected extrahepatic organs in cholestasis. The pivotal role of oxidative stress has been mentioned in the pathogenesis of cholestasis-induced organ injury. The activation of the nuclear factor-E2-related factor 2 (Nrf2) pathway is involved in response to oxidative stress. The current study was designed to evaluate the potential role of Nrf2 signaling activation in preventing bile acids-induced toxicity in the liver and kidney. Dimethyl fumarate was used as a robust activator of Nrf2 signaling. Rats underwent bile duct ligation surgery and were treated with dimethyl fumarate (10 and 40 mg/kg). Severe oxidative stress was evident in the liver and kidney of cholestatic animals (P < 0.05). On the other hand, the expression and activity of Nrf2 and downstream genes were time-dependently decreased (P < 0.05). Moreover, significant mitochondrial depolarization, decreased ATP levels, and mitochondrial permeabilization were detected in bile duct-ligated rats (P < 0.05). Histopathological alterations included liver necrosis, fibrosis, inflammation and kidney interstitial inflammation, and cast formation. It was found that dimethyl fumarate significantly decreased hepatic and renal injury in cholestatic animals (P < 0.05). Based on these data, the activation of the cellular antioxidant response could serve as an efficient therapeutic option for managing cholestasis-induced organ injury.

Naunyn Schmiedebergs Arch Pharmacol ; 394(6): 1191-1203, 2021 06.
Artigo em Inglês | MEDLINE | ID: mdl-33527194


Cholestasis is a clinical complication with different etiologies. The liver is the primary organ influenced in cholestasis. Renal injury is also a severe clinical complication in cholestatic/cirrhotic patients. Several studies mentioned the importance of oxidative stress and mitochondrial impairment as two mechanistically interrelated events in cholestasis-induced organ injury. Apoptosis-inducing factor (AIF) is a flavoprotein located in the inner mitochondrial membrane. This molecule is involved in a distinct pathway of cell death. The current study aimed to evaluate the role of AIF in the pathophysiology of cholestasis-associated hepatic and renal injury. Bile duct ligation (BDL) was used as an animal model of cholestasis. Serum, urine, and tissue samples were collected at scheduled time intervals (3, 7, 14, and 28 days after BDL surgery). Tissues' AIF mRNA levels, as well as serum, urine, and tissue activity of AIF, were measured. Moreover, markers of DNA fragmentation and apoptosis were assessed in the liver and kidney of cholestatic animals. A significant increase in liver and kidney AIF mRNA levels, in addition to increased AIF activity in the liver, kidney, serum, and urine, was detected in BDL rats. DNA fragmentation and apoptosis were raised in the liver and kidney of cholestatic animals, especially at the early stage of the disease. The apoptotic mode of cell death in the liver and kidney was connected to a higher AIF level. These data mention the importance of AIF in the pathogenesis of cholestasis-induced organ injury, especially at the early stage of this disease. Mitochondrial release of apoptosis-inducing factor (AIF) seems to play a pathogenic role in cholestasis-associated hepatic and renal injury. AIF release is directly connected to oxidative stress and mitochondrial impairment in cholestatic animals.

Sensors (Basel) ; 20(24)2020 Dec 15.
Artigo em Inglês | MEDLINE | ID: mdl-33333831


When a centrifugation-enriched sample of 100 µL containing the surface-enhanced Raman scattering (SERS) tag-bound bacteria (Salmonella in this study) is siphoned onto a glass slide next to an embedded thermoelectric heating chip, such a sessile droplet is quickly evaporated. As the size of the sample droplet is significantly reduced during the heating process, ionic wind streams from a corona discharge needle, stationed above the sample, sweep across the liquid surface to produce centrifugal vortex flow. Tag-bound Salmonella in the sample are then dragged and trapped at the center of droplet bottom. Finally, when the sample is dried, unlike the "coffee ring" effect, the SERS tag-bound Salmonella is concentrated in one small spot to allow sensitive detection of a Raman signal. Compared with our previous electrohydrodynamic concentration device containing only a corona discharge needle, this thermoelectric evaporation-assisted device is more time-effective, with the time of concentrating and drying about 100 µL sample reduced from 2 h to 30 min. Hence, sample throughput can be accelerated with this device for practical use. It is also more sensitive, with SERS detection of a few cells of Salmonella in neat samples achievable. We also evaluated the feasibility of using this device to detect Salmonella in food samples without performing the culturing procedures. Having spiked a few Salmonella cells into ice cubes and lettuce leaves, we use filtration and ultracentrifugation steps to obtain enriched tag-bound Salmonella samples of 200 µL. After loading an aliquot of 100 µL of sample onto this concentration device, the SERS tag signals from samples of 100 g ice cubes containing two Salmonella cells and 20 g lettuce leaf containing 5 Salmonella cells can be successfully detected.

Análise de Alimentos/instrumentação , Calefação , Salmonella , Centrifugação , Filtração , Análise de Alimentos/métodos , Microbiologia de Alimentos , Análise Espectral Raman
Ecotoxicol Environ Saf ; 204: 110973, 2020 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-32781346


Arsenic (As) exerts a wide range of adverse effects on biological systems, including the reproductive organs in males and females. However, the mechanisms of As-induced reproductive toxicity are mostly obscure. Recently, we showed that autophagy is an essential route for As2O3-induced reprotoxicity through the hypothalamic-pituitary-gonadal-sperm (HPG-S) axis in pubertal and matured F1-male mice. However, the role of autophagy in As2O3- induced ovarian toxicity is mostly unknown. Hence, this study aimed to elucidate the role of oxidative stress, mitochondrial impairment, and autophagic processes in the ovary of As-exposed female mice. For this purpose, mature female mice were challenged with 0, low (0.2), medium (2), and high (20 ppm) As2O3 from 35-days before mating till weaning their pups, and the F1- females from weaning until maturity. Then, all the mice were sacrificed, and oxidative stress parameters, mitochondrial indices, electron microscopic evaluation of the ovaries, expression of autophagic-related genes and proteins, and autophagosome formation were assessed. It was shown that medium and high As2O3 doses were a potent inducer of oxidative stress, mitochondrial dysfunction, and autophagy in the ovary of F1-generation. A dose-dependent increment in the gene expression of PDK1, PI3K, TSC2, AMPK, ULK1, ATG13, Beclin1, ATG12, ATG5, LC3, P62, ATG3, ATG7, and p62, as well as protein expression of Beclin1, and LC3- I, II, was evident in the ovaries of the As-treated animals. Moreover, a dose-dependent decrease in the expression of mTOR and Bcl-2 genes, and mTOR protein was detected with increasing doses of As, suggesting that As treatment-induced autophagy. Along with a dose-dependent increase in the number of MDC-labeled autophagic vacuoles, transmission electron microscopy also confirmed more autophagosomes and injured mitochondria in medium and high As2O3 doses groups. As2O3 also negatively affected the mean body weight, litter size, organ coefficient, and stereological indices in female mice. Finally, in physiological conditions, arsenic trioxide (As2O3) leads to an increased level of autophagy in the oocyte when many oocytes were being lost. These findings indicated that an imbalance in the oxidant-antioxidant system, mitochondrial impairment, and the autophagic process, through inhibition of mTOR, dependent and independent pathways, and Bcl-2, as well as activation of AMPK/PI3K/Beclin1/LC3 routes, could play a pivotal role in As-induced reproductive toxicity through ovarian dysfunction in females.

Arsênio/toxicidade , Autofagia/efeitos dos fármacos , Folículo Ovariano/efeitos dos fármacos , Ovário/efeitos dos fármacos , Animais , Feminino , Camundongos , Camundongos Endogâmicos BALB C , Microscopia Eletrônica de Transmissão , Folículo Ovariano/crescimento & desenvolvimento , Ovário/ultraestrutura , Distribuição Aleatória
Sensors (Basel) ; 18(9)2018 Sep 04.
Artigo em Inglês | MEDLINE | ID: mdl-30181484


This paper reports the work of developing one coplanar microfluidic sorter while using the electro-wetting on dielectrics (EWOD) technique. When connected with delivery capillary to receive sample solution containing micro-particles, this device can select about 10 micro-particles in high volume throughput of milliliter amount within 20 min, to potentially match the requirement of efficiently determining the low amounts of bacteria in concentrated food and environmental samples, of which the typical bacteria density is 10 colony forming unit or less, much smaller than that of clinical pathogen samples. This coplanar T-shape EWOD device contains two fluidic channels, one inlet channel and the other collection channel stemmed from the middle of inlet channel. When the solution droplet falls from the delivery capillary to the entrance end of inlet channel, the droplet is driven to the intersection of two channels. The droplet containing fluorescent particle will be diverted to the lower channel to collect. Otherwise, the non-fluorescent droplet keeps moving toward the other end of inlet channel to waste zone. The particle fluorescence is collected through microscope lens to detect with one photomultiplier tube. The detected signals trigger the personal computer control board to active each EWOD electrode to direct the droplet moving directions. When the solution of 1 mL containing about 10 fluorescent micro-particles is delivered into this sorting device, nearly all the particles were correctly directed into collection zone in 20 min.