Hepatocellular carcinoma (HCC) is the most common type of primary liver cancer and the fourth most frequent cause of cancer-related death worldwide. Sorafenib is the first line recommended therapy for patients with locally advanced/metastatic HCC. The low response rate is attributed to intrinsic resistance of HCC cells to Sorafenib. The potential resistance to Sorafenib-induced cell death is multifactorial and involves all hallmarks of cancer. However, the presence of sub-therapeutic dose can negatively influence the antitumoral properties of the drug. In this sense, the present study showed that the sub-optimal Sorafenib concentration (10 nM) was associated with activation of caspase-9, AMP-activated protein kinase (AMPK), sustained autophagy, peroxisome proliferator-activated receptor-coactivator 1α (PGC-1α) and mitochondrial function in HepG2 cells. The increased mitochondrial respiration by Sorafenib (10 nM) was also observed in permeabilized HepG2 cells, but not in isolated rat mitochondria, which suggests the involvement of an upstream component in this regulatory mechanism. The basal glycolysis was dose dependently increased at early time point studied (6 h). Interestingly, Sorafenib increased nitric oxide (NO) generation that played an inhibitory role in mitochondrial respiration in sub-therapeutic dose of Sorafenib. The administration of sustained therapeutic dose of Sorafenib (10 µM, 24 h) induced mitochondrial dysfunction and dropped basal glycolysis derived acidification, as well as increased oxidative stress and apoptosis in HepG2. In conclusion, the accurate control of the administered dose of Sorafenib is relevant for the potential prosurvival or proapoptotic properties induced by the drug in liver cancer cells.

• MeSH
• antitumorózní látky farmakologie   MeSH
• autofagie účinky léků   MeSH
• buněčná smrt účinky léků   MeSH
• buňky Hep G2 MeSH
• chemorezistence účinky léků   MeSH
• hepatocelulární karcinom metabolismus   patologie   MeSH
• jaterní mitochondrie účinky léků   metabolismus   MeSH
• kaspasa 9 metabolismus   MeSH
• lidé MeSH
• nádory jater metabolismus   patologie   MeSH
• oxid dusnatý metabolismus   MeSH
• potkani Wistar MeSH
• PPARGC1A metabolismus   MeSH
• proteinkinasy aktivované AMP metabolismus   MeSH
• signální transdukce účinky léků   MeSH
• sorafenib farmakologie   MeSH
• vztah mezi dávkou a účinkem léčiva MeSH
• zvířata MeSH
• Check Tag
• lidé MeSH
• mužské pohlaví MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH

By determining the calcium retention capacity (CRC) of rat liver mitochondria, we confirmed and extended previous observations describing the activation of mitochondrial swelling by phosphate and tert-butyl hydroperoxide (t-BHP). Using CRC measurements, we showed that both phosphate and t-BHP decrease the extent of calcium accumulation required for the full mitochondrial permeability transition pore (MPTP) opening to 35 % of control values and to only 15 % when both phosphate and t-BHP are present in the medium. When changes in fluorescence were evaluated at higher resolution, we observed that in the presence of cyclosporine A fluorescence values return after each Ca(2+) addition to basal values obtained before the Ca(2+) addition. This indicates that the MPTP remains closed. However, in the absence of cyclosporine A, the basal fluorescence after each Ca(2+) addition continuously increased. This increase was potentiated both by phosphate and t-BHP until the moment when the concentration of intramitochondrial calcium required for the full opening of the MPTP was reached. We conclude that in the absence of cyclosporine A, the MPTP is slowly opened after each Ca(2+) addition and that this rate of opening can be modified by various factors such as the composition of the media and the experimental protocol used.

• MeSH
• fosfáty farmakologie   MeSH
• jaterní mitochondrie účinky léků   metabolismus   MeSH
• krysa rodu rattus MeSH
• potkani Wistar MeSH
• terc-butylhydroperoxid farmakologie   MeSH
• transportní proteiny mitochondriální membrány metabolismus   MeSH
• vápník metabolismus   MeSH
• vztah mezi dávkou a účinkem léčiva MeSH
• zvířata MeSH
• Check Tag
• krysa rodu rattus MeSH
• mužské pohlaví MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH

Red palm oil (RPO) is a rich natural source of antioxidant vitamins, namely carotenes, tocopherols and tocotrienols. However, it contains approximately 50 % saturated fatty acids the regular consumption of which could negatively modify lipid profile. The aim of our study was to test whether 7 weeks of RPO supplementation (1 g/kg body weight/day) would affect blood glucose and lipid metabolism in adult male Wistar rats with altered thyroid status. We induced hypothyroidism and hyperthyroidism in rats by oral administration of either methimazole or mixture of thyroid hormones. Different thyroid status (EU - euthyroid, HY - hypothyroid and HT - hyperthyroid) was characterized by different serum thyroid hormones levels (total and free thyroxine and triiodothyronine), changes in the activity of a marker enzyme of thyroid status - liver mitochondrial glycerol-3-phosphate dehydrogenase, and altered absolute and relative heart weights. Fasting blood glucose levels were higher in HT rats in comparison with EU and HY rats, but the changes caused by RPO supplementation were not significant. The achievement of the HY status significantly increased serum levels of total cholesterol, as well as with high-density lipoprotein-cholesterol and low-density lipoprotein-cholesterol: 2.43+/-0.15, 1.48+/-0.09, 0.89+/-0.08 mmol/l, compared to EU: 1.14+/-0.06, 0.77+/-0.06, 0.34+/-0.05 mmol/l and HT: 1.01+/-0.06, 0.69+/-0.04, 0.20+/-0.03 mmol/l, respectively. RPO supplementation did not increase significantly levels of blood lipids but tended to increase glutathione levels in the liver. In conclusion, RPO supplementation did not induce the presumed deterioration of glucose and lipid metabolism in rats with three well-characterized alterations in thyroid status.

• MeSH
• glutathion metabolismus   MeSH
• hormony štítné žlázy krev   MeSH
• hypertyreóza metabolismus   MeSH
• hypotyreóza metabolismus   MeSH
• jaterní mitochondrie účinky léků   metabolismus   MeSH
• játra účinky léků   metabolismus   MeSH
• krevní glukóza metabolismus   MeSH
• krysa rodu rattus MeSH
• ledviny účinky léků   metabolismus   MeSH
• lipidy krev   MeSH
• palmový olej farmakologie   MeSH
• potkani Wistar MeSH
• potravní doplňky * MeSH
• štítná žláza metabolismus   MeSH
• tělesná hmotnost účinky léků   MeSH
• velikost orgánu účinky léků   MeSH
• zvířata MeSH
• Check Tag
• krysa rodu rattus MeSH
• mužské pohlaví MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH

CONTEXT: Acetaminophen (APAP) hepatotoxicity is often studied in primary cultures of hepatocytes of various species, but there are only few works comparing interspecies differences in susceptibility of hepatocytes to APAP in vitro. OBJECTIVES: The aim of our work was to compare hepatotoxicity of APAP in rat and mouse hepatocytes in primary cultures. MATERIALS AND METHODS: Hepatocytes isolated from male Wistar rats and C57Bl/6J mice were exposed to APAP for up to 24 h. We determined lactate dehydrogenase (LDH) activity in culture medium, activity of cellular dehydrogenases (WST-1) and activity of caspases 3 in cell lysate as markers of cell damage/death. We assessed content of intracellular reduced glutathione, production of reactive oxygen species (ROS) and malondialdehyde (MDA). Respiration of digitonin-permeabilized hepatocytes was measured by high resolution respirometry and mitochondrial membrane potential (MMP) was visualized (JC-1). RESULTS: APAP from concentrations of 2.5 and 0.75 mmol/L induced a decrease in viability of rat (p < 0.001) and mouse (p < 0.001) hepatocytes (WST-1), respectively. In contrast to rat hepatocytes, there was no activation of caspase-3 in mouse hepatocytes after APAP treatment. Earlier damage to plasma membrane and faster depletion of reduced glutathione were detected in mouse hepatocytes. Mouse hepatocytes showed increased glutamate + malate-driven respiration in state 4 and higher susceptibility of the outer mitochondrial membrane (OMM) to APAP-induced injury. CONCLUSION: APAP displayed dose-dependent toxicity in hepatocytes of both species. Mouse hepatocytes in primary culture however had approximately three-fold higher susceptibility to the toxic effect of APAP when compared to rat hepatocytes.

• MeSH
• biologické markery metabolismus   MeSH
• buněčná membrána účinky léků   metabolismus   MeSH
• druhová specificita MeSH
• glutathion metabolismus   MeSH
• hepatocyty cytologie   účinky léků   metabolismus   MeSH
• jaterní mitochondrie účinky léků   enzymologie   metabolismus   MeSH
• kultivované buňky MeSH
• membránový potenciál mitochondrií účinky léků   MeSH
• mitochondriální membrány účinky léků   metabolismus   MeSH
• myši inbrední C57BL MeSH
• neopioidní analgetika škodlivé účinky   MeSH
• oxidace-redukce MeSH
• oxidační stres účinky léků   MeSH
• paracetamol škodlivé účinky   MeSH
• peroxidace lipidů účinky léků   MeSH
• potkani Wistar MeSH
• reaktivní formy kyslíku agonisté   metabolismus   MeSH
• viabilita buněk účinky léků   MeSH
• zvířata MeSH
• Check Tag
• mužské pohlaví MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• srovnávací studie MeSH

Epigallocatechin gallate (EGCG) is a green tea antioxidant with adverse effects on rat liver mitochondria and hepatocytes at high doses. Here, we assessed whether low doses of EGCG would protect these systems from damage induced by tert-butyl hydroperoxide (tBHP). Rat liver mitochondria or permeabilized rat hepatocytes were pretreated with EGCG and then exposed to tBHP. Oxygen consumption, mitochondrial membrane potential (MMP), and mitochondrial retention capacity for calcium were measured. First, 50 μM EGCG or 0.25 mM tBHP alone increased State 4 Complex I-driven respiration, thus demonstrating uncoupling effects; tBHP also inhibited State 3 ADP-stimulated respiration. Then, the coexposure to 0.25 mM tBHP and 50 μM EGCG induced a trend of further decline in the respiratory control ratio beyond that observed upon tBHP exposure alone. EGCG had no effect on MMP and no effect, in concentrations up to 50 μM, on mitochondrial calcium retention capacity. tBHP led to a decline in both MMP and mitochondrial retention capacity for calcium; these effects were not changed by pretreatment with EGCG. In addition, EGCG dose-dependently enhanced hydrogen peroxide formation in a cell- and mitochondria-free medium. Conclusion. Moderate nontoxic doses of EGCG were not able to protect rat liver mitochondria and hepatocytes from tBHP-induced mitochondrial dysfunction.

• MeSH
• hepatocyty cytologie   účinky léků   metabolismus   MeSH
• jaterní mitochondrie účinky léků   metabolismus   MeSH
• katechin analogy a deriváty   farmakologie   MeSH
• krysa rodu rattus MeSH
• kultivované buňky MeSH
• membránový potenciál mitochondrií účinky léků   MeSH
• peroxid vodíku metabolismus   MeSH
• potkani Wistar MeSH
• spotřeba kyslíku účinky léků   MeSH
• terc-butylhydroperoxid toxicita   MeSH
• vápník metabolismus   MeSH
• zvířata MeSH
• Check Tag
• krysa rodu rattus MeSH
• mužské pohlaví MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH

Using a novel method for evaluating mitochondrial swelling (Drahota et al. 2012a) we studied the effect of calcium (Ca(2+)), phosphate (P(i)), and triiodothyronine (T(3)) on the opening of mitochondrial membrane permeability transition pore and how they interact in the activation of swelling process. We found that 0.1 mM P(i), 50 microM Ca(2+) and 25 microM T(3) when added separately increase the swelling rate to about 10 % of maximal values when all three factors are applied simultaneously. Our findings document that under experimental conditions in which Ca(2+) and P(i) are used as activating factors, the addition of T(3) doubled the rate of swelling. T(3) has also an activating effect on mitochondrial membrane potential. The T(3) activating effect was also found after in vivo application of T(3). Our data thus demonstrate that T(3) has an important role in opening the mitochondrial membrane permeability pore and activates the function of the two key physiological swelling inducers, calcium and phosphate ions.

• MeSH
• jaterní mitochondrie účinky léků   metabolismus   MeSH
• krysa rodu rattus MeSH
• potkani Wistar MeSH
• transportní proteiny mitochondriální membrány metabolismus   MeSH
• trijodthyronin metabolismus   farmakologie   MeSH
• vápník metabolismus   farmakologie   MeSH
• vztah mezi dávkou a účinkem léčiva MeSH
• zvířata MeSH
• Check Tag
• krysa rodu rattus MeSH
• mužské pohlaví MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH

A compound with promising anticancer properties, 3-bromopyruvate (3-BP) is a synthetic derivative of a pyruvate molecule; however, its toxicity in non-malignant cells has not yet been fully elucidated. Therefore, we elected to study the effects of 3-BP on primary hepatocytes in monolayer cultures, permeabilized hepatocytes and isolated mitochondria. After a 1-h treatment with 100 μM 3-BP cell viability of rat hepatocytes was decreased by 30 % as measured by the WST-1 test (p < 0.001); after 3-h exposure to ≥200 μM 3-BP lactate dehydrogenase leakage was increased (p < 0.001). Reactive oxygen species production was increased in the cell cultures after a 1-h treatment at concentrations ≥100 μmol/l (p < 0.01), and caspase 3 activity was increased after a 20-h incubation with 150 μM and 200 μM 3-BP (p < 0.001). This toxic effect of 3-BP was also proved using primary mouse hepatocytes. In isolated mitochondria, 3-BP induced a dose- and time-dependent decrease of mitochondrial membrane potential during a 10-min incubation both with Complex I substrates glutamate + malate or Complex II substrate succinate, although this decrease was more pronounced with the latter. We also measured the effect of 3-BP on respiration of isolated mitochondria. ADP-activated respiration was inhibited by 20 μM 3-BP within 10 min. Similar effects were also found in permeabilized hepatocytes of both species.

• MeSH
• časové faktory MeSH
• hepatocyty cytologie   účinky léků   ultrastruktura   MeSH
• jaterní mitochondrie účinky léků   MeSH
• krysa rodu rattus MeSH
• kultivované buňky MeSH
• membránový potenciál mitochondrií účinky léků   MeSH
• mitochondriální nemoci chemicky indukované   patofyziologie   MeSH
• myši MeSH
• pyruváty farmakologie   toxicita   MeSH
• reaktivní formy kyslíku metabolismus   MeSH
• viabilita buněk účinky léků   MeSH
• vztah mezi dávkou a účinkem léčiva MeSH
• zvířata MeSH
• Check Tag
• krysa rodu rattus MeSH
• myši MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH

In vitro models serve as a tool for studies of steatosis. Palmitic and oleic acids can induce steatosis in cultured hepatocytes. The aim of our study was to verify steatogenic and cytotoxic effects of palmitic acid (PA), oleic acid (OA) and their combinations as well as their impact on functional capacity of rat primary hepatocytes. Hepatocytes were exposed to OA or PA (0.125-2 mmol/l) or their combination at ratios of 3:1, 2:1 or 1:1 at the final concentrations of 0.5-1 mmol/l. Both OA and PA caused a dose-dependent increase in triacylglycerol content in hepatocytes. PA was more steatogenic at 0.25 and 0.5 mmol/l while OA at 0.75 and 1 mmol/l. PA exhibited a dose-dependent cytotoxic effect associated with ROS production, present markers of apoptosis and necrosis and a decrease in albumin production. OA induced a damage of the cytoplasmic membrane from 1 mM concentration. Mixture of OA and PA induced lower cytotoxicity with less weakened functional capacity than did PA alone. Extent of steatosis was comparable to that after exposure to OA alone. In conclusion, OA or combination of OA with PA is more suitable for simulation of simple steatosis than PA alone.

• MeSH
• albuminy metabolismus   MeSH
• apoptóza účinky léků   MeSH
• hepatocyty účinky léků   metabolismus   patologie   MeSH
• jaterní mitochondrie účinky léků   metabolismus   patologie   MeSH
• kultivované buňky MeSH
• kyselina olejová toxicita   MeSH
• kyselina palmitová toxicita   MeSH
• membránový potenciál mitochondrií účinky léků   MeSH
• nealkoholová steatóza jater chemicky indukované   metabolismus   patologie   MeSH
• nekróza MeSH
• potkani Wistar MeSH
• primární buněčná kultura MeSH
• reaktivní formy kyslíku metabolismus   MeSH
• triglyceridy metabolismus   MeSH
• viabilita buněk účinky léků   MeSH
• vztah mezi dávkou a účinkem léčiva MeSH
• zvířata MeSH
• Check Tag
• mužské pohlaví MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• srovnávací studie MeSH

The aim of our work was to compare the effect of D-galactosamine (GalN) on primary cultures of lean and steatotic rat hepatocytes isolated from intact and fatty liver, respectively. GalN caused more severe injury to steatotic hepatocytes than to lean cells as documented by lactate dehydrogenase leakage. Necrotic mode of cell death strongly prevails over apoptosis since we did not observe any significant increase in activities of caspase 3, 8 and 9 in any group of hepatocytes treated with GalN. Reactive oxygen species (ROS) formation and lipid peroxidation were elevated in a dose-dependent manner by GalN and were significantly more pronounced in fatty hepatocytes. A decrease in the percentage of hepatocytes with energized mitochondria was observed from 30 mM and 10 mM GalN in lean and steatotic hepatocytes, respectively. Our results undoubtedly indicate that steatotic hepatocytes exert higher sensitivity to the toxic effect of GalN. This sensitivity may be caused by more intensive GalN-induced ROS production and lipid peroxidation and by higher susceptibility of mitochondria to loss of mitochondrial membrane potential in steatotic hepatocytes. In our experimental arrangement, apoptosis does not seem to participate considerably on hepatotoxic action of GalN in either group of hepatocytes.

• MeSH
• apoptóza účinky léků   MeSH
• biologické markery metabolismus   MeSH
• galaktosamin farmakologie   MeSH
• hepatocyty účinky léků   metabolismus   patologie   MeSH
• jaterní mitochondrie účinky léků   metabolismus   patologie   MeSH
• kultivované buňky MeSH
• L-laktátdehydrogenasa metabolismus   MeSH
• membránový potenciál mitochondrií účinky léků   MeSH
• modely nemocí na zvířatech MeSH
• nealkoholová steatóza jater metabolismus   patologie   MeSH
• nekróza MeSH
• peroxidace lipidů účinky léků   MeSH
• potkani Wistar MeSH
• primární buněčná kultura MeSH
• reaktivní formy kyslíku metabolismus   MeSH
• vztah mezi dávkou a účinkem léčiva MeSH
• zvířata MeSH
• Check Tag
• mužské pohlaví MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• srovnávací studie MeSH

We compared the effect of alpha-tocopheryl succinate (TOS) on succinate-dependent respiration in rat liver mitochondria, homogenate and permeabilized hepatocytes in both a coupled and uncoupled state. In isolated mitochondria, a significant inhibitory effect was observed at a concentration of 5 microM, in liver homogenate at 25 microM and in permeabilized hepatocytes at 50 microM. The inhibitory effect of TOS on succinate respiration in an uncoupled state was less pronounced than in a coupled state in all the experimental models tested. When the concentration dependence of the TOS inhibitory effect was tested, the most sensitive in both states were isolated mitochondria; the most resistant were permeabilized hepatocytes.

• MeSH
• alfa-tokoferol metabolismus   farmakologie   MeSH
• buněčná membrána metabolismus   MeSH
• buněčné dýchání účinky léků   MeSH
• časové faktory MeSH
• energetický metabolismus účinky léků   MeSH
• hepatocyty účinky léků   metabolismus   MeSH
• jaterní mitochondrie účinky léků   metabolismus   MeSH
• karbonylkyanid-p-trifluormethoxyfenylhydrazon farmakologie   MeSH
• oxidativní fosforylace účinky léků   MeSH
• permeabilita buněčné membrány MeSH
• potkani Wistar MeSH
• respirační komplex II metabolismus   MeSH
• rozpřahující látky farmakologie   MeSH
• vztah mezi dávkou a účinkem léčiva MeSH
• zvířata MeSH
• Check Tag
• mužské pohlaví MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• srovnávací studie MeSH