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Cahova M, Palenickova E, Dankova H, Sticova E, Burian M, Drahota Z, Cervinkova Z, Kucera O, Gladkova C, Stopka P, Krizova J, Papackova Z, Oliyarnyk O, Kazdova L. Metformin prevents ischemia reperfusion-induced oxidative stress in the fatty liver by attenuation of reactive oxygen species formation. Am J Physiol Gastrointest Liver Physiol 2015; 309:G100-11. [PMID: 26045616 DOI: 10.1152/ajpgi.00329.2014] [Citation(s) in RCA: 80] [Impact Index Per Article: 8.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/04/2014] [Accepted: 05/21/2015] [Indexed: 01/31/2023]
Abstract
Nonalcoholic fatty liver disease is associated with chronic oxidative stress. In our study, we explored the antioxidant effect of antidiabetic metformin on chronic [high-fat diet (HFD)-induced] and acute oxidative stress induced by short-term warm partial ischemia-reperfusion (I/R) or on a combination of both in the liver. Wistar rats were fed a standard diet (SD) or HFD for 10 wk, half of them being administered metformin (150 mg·kg body wt(-1)·day(-1)). Metformin treatment prevented acute stress-induced necroinflammatory reaction, reduced alanine aminotransferase and aspartate aminotransferase serum activity, and diminished lipoperoxidation. The effect was more pronounced in the HFD than in the SD group. The metformin-treated groups exhibited less severe mitochondrial damage (markers: cytochrome c release, citrate synthase activity, mtDNA copy number, mitochondrial respiration) and apoptosis (caspase 9 and caspase 3 activation). Metformin-treated HFD-fed rats subjected to I/R exhibited increased antioxidant enzyme activity as well as attenuated mitochondrial respiratory capacity and ATP resynthesis. The exposure to I/R significantly increased NADH- and succinate-related reactive oxygen species (ROS) mitochondrial production in vitro. The effect of I/R was significantly alleviated by previous metformin treatment. Metformin downregulated the I/R-induced expression of proinflammatory (TNF-α, TLR4, IL-1β, Ccr2) and infiltrating monocyte (Ly6c) and macrophage (CD11b) markers. Our data indicate that metformin reduces mitochondrial performance but concomitantly protects the liver from I/R-induced injury. We propose that the beneficial effect of metformin action is based on a combination of three contributory mechanisms: increased antioxidant enzyme activity, lower mitochondrial ROS production, and reduction of postischemic inflammation.
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Affiliation(s)
- Monika Cahova
- Center for Experimental Medicine, Department of Metabolism and Diabetes, Charles University, Prague, Czech Republic;
| | - Eliska Palenickova
- Center for Experimental Medicine, Department of Metabolism and Diabetes, Charles University, Prague, Czech Republic; Department of Cell Biology, Faculty of Science, Charles University, Prague, Czech Republic
| | - Helena Dankova
- Center for Experimental Medicine, Department of Metabolism and Diabetes, Charles University, Prague, Czech Republic
| | - Eva Sticova
- Clinical and Transplant Pathology Department, Charles University, Prague, Czech Republic
| | - Martin Burian
- Department of Diagnostic and Interventional Radiology, Institute for Clinical and Experimental Medicine, Prague, Czech Republic
| | - Zdenek Drahota
- Institute of Physiology, Czech Academy of Sciences, Prague, Czech Republic
| | - Zuzana Cervinkova
- Department of Physiology, Charles University in Prague, Faculty of Medicine in Hradec Kralove, Hradec Kralove, Czech Republic
| | - Otto Kucera
- Department of Physiology, Charles University in Prague, Faculty of Medicine in Hradec Kralove, Hradec Kralove, Czech Republic
| | - Christina Gladkova
- Department of Chemistry, University of Cambridge, Cambridge, United Kingdom; and
| | - Pavel Stopka
- Institute of Inorganic Chemistry Academy of Science CR, Husinec-Rez, Czech Republic
| | - Jana Krizova
- Institute of Inorganic Chemistry Academy of Science CR, Husinec-Rez, Czech Republic
| | - Zuzana Papackova
- Center for Experimental Medicine, Department of Metabolism and Diabetes, Charles University, Prague, Czech Republic
| | - Olena Oliyarnyk
- Center for Experimental Medicine, Department of Metabolism and Diabetes, Charles University, Prague, Czech Republic
| | - Ludmila Kazdova
- Center for Experimental Medicine, Department of Metabolism and Diabetes, Charles University, Prague, Czech Republic
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Cahova M, Chrastina P, Hansikova H, Drahota Z, Trnovska J, Skop V, Spacilova J, Malinska H, Oliyarnyk O, Papackova Z, Palenickova E, Kazdova L. Carnitine supplementation alleviates lipid metabolism derangements and protects against oxidative stress in non-obese hereditary hypertriglyceridemic rats. Appl Physiol Nutr Metab 2015; 40:280-91. [DOI: 10.1139/apnm-2014-0163] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/01/2023]
Abstract
The aim of this study was to estimate the effect of carnitine supplementation on lipid disorders and peripheral tissue insulin sensitivity in a non-obese animal model of insulin resistance, the hereditary hypertriglyceridemic (HHTg) rat. Male HHTg rats were fed a standard diet, and half of them received daily doses of carnitine (500 mg·kg−1body weight) for 8 weeks. Rats of the original Wistar strain were used for comparison. HHTg rats exhibited increased urinary excretion of free carnitine and reduced carnitine content in the liver and blood. Carnitine supplementation compensated for this shortage and promoted urinary excretion of acetylcarnitine without any signs of (acyl)carnitine accumulation in skeletal muscle. Compared with their untreated littermates, carnitine-treated HHTg rats exhibited lower weight gain, reduced liver steatosis, lower fasting triglyceridemia, and greater reduction of serum free fatty acid content after glucose load. Carnitine treatment was associated with increased mitochondrial biogenesis and oxidative capacity for fatty acids, amelioration of oxidative stress, and restored substrate switching in the liver. In skeletal muscle (diaphragm), carnitine supplementation was associated with significantly higher palmitate oxidation and a more favorable complete to incomplete oxidation products ratio. Carnitine supplementation further enhanced insulin sensitivity ex vivo. No effects on whole-body glucose tolerance were observed. Our data suggest that some metabolic syndrome-related disorders, particularly fatty acid oxidation, steatosis, and oxidative stress in the liver, could be attenuated by carnitine supplementation. The effect of carnitine could be explained, at least partly, by enhanced substrate oxidation and increased fatty acid transport from tissues in the form of short-chain acylcarnitines.
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Affiliation(s)
- Monika Cahova
- Center for Experimental Medicine, Institute for Clinical and Experimental Medicine, Videnska 1958/9, Prague 4, Czech Republic
| | - Petr Chrastina
- Institute of Inherited Metabolic Disorders, First Faculty of Medicine, Charles University in Prague and General University Hospital in Prague, Prague 2, Czech Republic
| | - Hana Hansikova
- Department of Pediatrics and Adolescent Medicine, First Faculty of Medicine, Charles University in Prague and General University Hospital in Prague, Prague 2, Czech Republic
| | - Zdenek Drahota
- Institute of Physiology, Czech Academy of Sciences, Prague 4, Czech Republic
| | - Jaroslava Trnovska
- Center for Experimental Medicine, Institute for Clinical and Experimental Medicine, Videnska 1958/9, Prague 4, Czech Republic
| | - Vojtech Skop
- Center for Experimental Medicine, Institute for Clinical and Experimental Medicine, Videnska 1958/9, Prague 4, Czech Republic
- Department of Biochemistry and Microbiology, Institute of Chemical Technology, Prague 6, Czech Republic
| | - Jana Spacilova
- Department of Pediatrics and Adolescent Medicine, First Faculty of Medicine, Charles University in Prague and General University Hospital in Prague, Prague 2, Czech Republic
| | - Hana Malinska
- Center for Experimental Medicine, Institute for Clinical and Experimental Medicine, Videnska 1958/9, Prague 4, Czech Republic
| | - Olena Oliyarnyk
- Center for Experimental Medicine, Institute for Clinical and Experimental Medicine, Videnska 1958/9, Prague 4, Czech Republic
| | - Zuzana Papackova
- Center for Experimental Medicine, Institute for Clinical and Experimental Medicine, Videnska 1958/9, Prague 4, Czech Republic
| | - Eliska Palenickova
- Center for Experimental Medicine, Institute for Clinical and Experimental Medicine, Videnska 1958/9, Prague 4, Czech Republic
- Department of Cell Biology, Faculty of Science, Charles University in Prague, Prague 2, Czech Republic
| | - Ludmila Kazdova
- Center for Experimental Medicine, Institute for Clinical and Experimental Medicine, Videnska 1958/9, Prague 4, Czech Republic
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Skop V, Cahova M, Dankova H, Papackova Z, Palenickova E, Svoboda P, Zidkova J, Kazdova L. Autophagy inhibition in early but not in later stages prevents 3T3-L1 differentiation: Effect on mitochondrial remodeling. Differentiation 2014; 87:220-9. [PMID: 25041706 DOI: 10.1016/j.diff.2014.06.002] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/29/2014] [Revised: 06/13/2014] [Accepted: 06/18/2014] [Indexed: 11/29/2022]
Abstract
Autophagy is essential for successful white adipocyte differentiation but the data regarding the timing and relevance of autophagy action during different phases of adipogenesis are limited. We subjected 3T3-L1 preadipocytes to a standard differentiation protocol and inhibited the autophagy within time-limited periods (days 0-2; 2-4; 4-6; 6-8) by asparagine or 3-methyladenine. In the normal course of events, both autophagy flux and the mRNA expression of autophagy related genes (Atg5, Atg12, Atg16, beclin 1) is most intensive at the beginning of differentiation (days 0-4) and then declines. The initiation of differentiation is associated with a 50% reduction of the mitochondrial copy number on day 2 followed by rapid mitochondrial biogenesis. Preadipocytes and differentiated adipocytes differ in the mRNA expression of genes involved in electron transport (Nufsd1, Sdhb, Uqcrc1); ATP synthesis (ATP5b); fatty acid metabolism (CPT1b, Acadl); mitochondrial transporters (Hspa9, Slc25A1) and the TCA cycle (Pcx, Mdh2) as well as citrate synthase activity. Autophagy inhibition during the first two days of differentiation blocked both phenotype changes (lipid accumulation) and the gene expression pattern, while having no or only a marginal effect over any other time period. Similarly, autophagy inhibition between days 0-2 inhibited mitotic clonal expansion as well as mitochondrial network remodeling. In conclusion, we found that autophagy is essential and most active during an initial stage of adipocyte differentiation but it is dispensable during its later stages. We propose that the degradation of preadipocyte cytoplasmic structures, predominantly mitochondria, is an important function of autophagy during this phase and its absence prevents remodeling of the mitochondrial gene expression pattern and mitochondrial network organization.
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Affiliation(s)
- Vojtech Skop
- Center of Experimental Medicine, Institute for Clinical and Experimental Medicine, Prague, Czech Republic; Department of Biochemistry and Microbiology, Institute of Chemical Technology Prague, Prague, Czech Republic
| | - Monika Cahova
- Center of Experimental Medicine, Institute for Clinical and Experimental Medicine, Prague, Czech Republic.
| | - Helena Dankova
- Center of Experimental Medicine, Institute for Clinical and Experimental Medicine, Prague, Czech Republic
| | - Zuzana Papackova
- Center of Experimental Medicine, Institute for Clinical and Experimental Medicine, Prague, Czech Republic
| | - Eliska Palenickova
- Department of Cell Biology, Faculty of Science, Charles University, Prague, Czech Republic
| | - Petr Svoboda
- Department of Biochemistry and Microbiology, Institute of Chemical Technology Prague, Prague, Czech Republic
| | - Jarmila Zidkova
- Department of Biochemistry and Microbiology, Institute of Chemical Technology Prague, Prague, Czech Republic
| | - Ludmila Kazdova
- Center of Experimental Medicine, Institute for Clinical and Experimental Medicine, Prague, Czech Republic
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Drahota Z, Palenickova E, Endlicher R, Milerova M, Brejchova J, Vosahlikova M, Svoboda P, Kazdova L, Kalous M, Cervinkova Z, Cahova M. Biguanides inhibit complex I, II and IV of rat liver mitochondria and modify their functional properties. Physiol Res 2013; 63:1-11. [PMID: 24182344 DOI: 10.33549/physiolres.932600] [Citation(s) in RCA: 35] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022] Open
Abstract
In this study, we focused on an analysis of biguanides effects on mitochondrial enzyme activities, mitochondrial membrane potential and membrane permeability transition pore function. We used phenformin, which is more efficient than metformin, and evaluated its effect on rat liver mitochondria and isolated hepatocytes. In contrast to previously published data, we found that phenformin, after a 5 min pre-incubation, dose-dependently inhibits not only mitochondrial complex I but also complex II and IV activity in isolated mitochondria. The enzymes complexes inhibition is paralleled by the decreased respiratory control index and mitochondrial membrane potential. Direct measurements of mitochondrial swelling revealed that phenformin increases the resistance of the permeability transition pore to Ca(2+) ions. Our data might be in agreement with the hypothesis of Schäfer (1976) that binding of biguanides to membrane phospholipids alters membrane properties in a non-specific manner and, subsequently, different enzyme activities are modified via lipid phase. However, our measurements of anisotropy of fluorescence of hydrophobic membrane probe diphenylhexatriene have not shown a measurable effect of membrane fluidity with the 1 mM concentration of phenformin that strongly inhibited complex I activity. Our data therefore suggest that biguanides could be considered as agents with high efficacy but low specifity.
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Affiliation(s)
- Z Drahota
- Centre of Experimental Medicine, Institute for Clinical and Experimental Medicine, Prague, Czech Republic.
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Papackova Z, Palenickova E, Dankova H, Zdychova J, Skop V, Kazdova L, Cahova M. Kupffer cells ameliorate hepatic insulin resistance induced by high-fat diet rich in monounsaturated fatty acids: the evidence for the involvement of alternatively activated macrophages. Nutr Metab (Lond) 2012; 9:22. [PMID: 22439764 PMCID: PMC3348013 DOI: 10.1186/1743-7075-9-22] [Citation(s) in RCA: 35] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/17/2011] [Accepted: 03/22/2012] [Indexed: 12/15/2022] Open
Abstract
BACKGROUND Resident macrophages (Kupffer cells, KCs) in the liver can undergo both pro- or anti-inflammatory activation pathway and exert either beneficiary or detrimental effects on liver metabolism. Until now, their role in the metabolically dysfunctional state of steatosis remains enigmatic. Aim of our study was to characterize the role of KCs in relation to the onset of hepatic insulin resistance induced by a high-fat (HF) diet rich in monounsaturated fatty acids. METHODS Male Wistar rats were fed either standard (SD) or high-fat (HF) diet for 4 weeks. Half of the animals were subjected to the acute GdCl3 treatment 24 and 72 hrs prior to the end of the experiment in order to induce the reduction of KCs population. We determined the effect of HF diet on activation status of liver macrophages and on the changes in hepatic insulin sensitivity and triacylglycerol metabolism imposed by acute KCs depletion by GdCl3. RESULTS We found that a HF diet rich in MUFA itself triggers an alternative but not the classical activation program in KCs. In a steatotic, but not in normal liver, a reduction of the KCs population was associated with a decrease of alternative activation and with a shift towards the expression of pro-inflammatory activation markers, with the increased autophagy, elevated lysosomal lipolysis, increased formation of DAG, PKCε activation and marked exacerbation of HF diet-induced hepatic insulin resistance. CONCLUSIONS We propose that in the presence of a high MUFA content the population of alternatively activated resident liver macrophages may mediate beneficial effects on liver insulin sensitivity and alleviate the metabolic disturbances imposed by HF diet feeding and steatosis. Our data indicate that macrophage polarization towards an alternative state might be a useful strategy for treating type 2 diabetes.
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Affiliation(s)
- Zuzana Papackova
- Department of Metabolism and Diabetes, Institute for Clinical and Experimental Medicine, Videnska 1958/9, Prague 14021, Czech Republic
| | - Eliska Palenickova
- Department of Metabolism and Diabetes, Institute for Clinical and Experimental Medicine, Videnska 1958/9, Prague 14021, Czech Republic
| | - Helena Dankova
- Department of Metabolism and Diabetes, Institute for Clinical and Experimental Medicine, Videnska 1958/9, Prague 14021, Czech Republic
| | - Jana Zdychova
- Department of Metabolism and Diabetes, Institute for Clinical and Experimental Medicine, Videnska 1958/9, Prague 14021, Czech Republic
| | - Vojtech Skop
- Institute for Chemical Technology, Prague, Czech Republic
| | - Ludmila Kazdova
- Department of Metabolism and Diabetes, Institute for Clinical and Experimental Medicine, Videnska 1958/9, Prague 14021, Czech Republic
| | - Monika Cahova
- Department of Metabolism and Diabetes, Institute for Clinical and Experimental Medicine, Videnska 1958/9, Prague 14021, Czech Republic
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Cahova M, Palenickova E, Papackova Z, Dankova H, Skop V, Kazdova L. Epinephrine-dependent control of glucose metabolism in white adipose tissue: the role of α- and β-adrenergic signalling. Exp Biol Med (Maywood) 2012; 237:211-8. [PMID: 22302710 DOI: 10.1258/ebm.2011.011189] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Epinephrine controls many important and sometimes opposite processes. This pleiotropic effect is achieved via coupling to different receptor/effector systems. In epididymal white adipose tissue (EWAT) of Wistar rats, we showed that epinephrine stimulated protein kinase B (PKB) phosphorylation on Ser(473). Epinephrine further increased the glucose incorporation into glyceride-glycerol without decreasing glucose availability for other metabolic pathways (i.e. lactate production). Wortmannin (phosphatidylinositol 3-kinase inhibitor) treatment significantly decreased glucose incorporation into glyceride-glycerol and elevated the epinephrine-induced release of free fatty acids (FFA) from the adipose tissue without any change in the intensity of lipolysis measured as glycerol release. Using specific cyclic adenosine monophosphate (cAMP) analogs we demonstrated that cAMP-protein kinase A (PKA) signalling resulted in a strong PKB dephosphorylation and significantly lowered the glucose availability in EWAT. Specific activation of the Epac (exchange protein activated by cAMP)-dependent pathway had only a moderately negative effect on PKB phosphorylation and glucose metabolism. In contrast, α(1) agonist methoxamine increased PKB phosphorylation and lactate production. This effect of methoxamine was additive to the effect of insulin and it was abolished by wortmannin treatment. In EWAT of spontaneously dyslipidemic hereditary hypertriglyceridemic (HHTg) rats, we demonstrated significantly lower epinephrine-induced glucose utilization but higher sensitivity to its lipolytic effect. We conclude that in EWAT, epinephrine controls two opposite processes (FFA release and FFA retention) via two different effector systems. The impairment of α(1)-dependent, epinephrine-stimulated, glycolysis-dependent FFA esterification may contribute to the establishment of dyslipidemia in insulin resistance.
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Affiliation(s)
- Monika Cahova
- Department of Metabolism and Diabetes, Institute for Clinical and Experimental Medicine, Videnska 1958/9, Prague 4, Czech Republic.
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Cahova M, Drahota Z, Dankova H, Oliyarnyk O, Palenickova E, Papackova Z, Markova I, Kazdova L. P271 ACTIVATION OF LYSOSOMES BY INTRACELLULAR TRIACYLGLYCEROL ACCUMULATION CONTRIBUTES TO THE DEVELOPMENT OF HEPATIC INSULIN RESISTANCE AND OXIDATIVE STRESS. ATHEROSCLEROSIS SUPP 2010. [DOI: 10.1016/s1567-5688(10)70338-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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