Lopimune-induced mitochondrial toxicity is attenuated by increased uncoupling protein-2 level in treated mouse hepatocytes

2015 ◽  
Vol 468 (3) ◽  
pp. 401-407 ◽  
Author(s):  
Sara El Hoss ◽  
Georges M. Bahr ◽  
Karim S. Echtay

We have demonstrated that the antiretroviral protease inhibitor Lopimune increases oxidative stress in mouse hepatocytes and subsequently mitochondrial proton leakage. This effect is mediated by increased uncoupling protein-2 expression which in turn inhibits ROS production as a negative feedback regulatory mechanism.

2014 ◽  
Vol 175 (1) ◽  
pp. 206-210 ◽  
Author(s):  
Shuangtao Ma ◽  
Yan Zhang ◽  
Qiang Wang ◽  
Dachun Yang ◽  
De Li ◽  
...  

2002 ◽  
Vol 80 (6) ◽  
pp. 757-764 ◽  
Author(s):  
Carine Duval ◽  
Anne Nègre-Salvayre ◽  
Alain Doglio ◽  
Robert Salvayre ◽  
Luc Pénicaud ◽  
...  

Uncoupling protein 2 (UCP-2) belongs to the mitochondrial anion carrier family. It is ubiquitously expressed but is most abdundant in the reticuloendothelial system. In addition to uncoupling function, UCP-2 modulates the production of reactive oxygen species (ROS) by isolated mitochondria. Using an antisense oligonucleotide strategy, we investigated whether a defect in UCP-2 expression modulates ROS in intact endothelial cells. Murine endothelial cells (CRL 2181) pretreated by antisense oligonucleotides directed against UCP-2 mRNA exhibited a significant and specific increase in membrane potential and intracellular ROS level compared with control scrambled or anti-UCP-1 and -UCP-3 antisense oligonucleotides. These specific changes induced by UCP-2 antisense oligonucleotides were correlated with a rise in extracellular superoxide anion production and oxidative stress assessed by thiobarbituric acid reactive substance values. Taken together, these data suggest a role for UCP-2 in control of ROS production and subsequent oxidation of surrounding compounds mediating oxidative stress of endothelial cells. These data also support the notion that manipulations of UCP-2 at the genetic level could control ROS metabolism at the cellular level.Key words: UCP-2, reactive oxygen species, LDL oxidation, oxidative stress, mitochondria, endothelial cells.


2008 ◽  
Vol 20 (9) ◽  
pp. 15
Author(s):  
M. L. Jones ◽  
P. J. Mark ◽  
B. J. Waddell

Placental oxidative stress plays a key role in the pathophysiology of placenta-related disorders in humans, most notably in preeclampsia (PE) and intrauterine growth restriction (IUGR). Protection from oxidative stress is provided by antioxidant enzymes including superoxide dismutase-1 and 2 (SOD-1 and –2) and catalase (CAT), which convert reactive oxygen species (ROS) to inert products. It has also been proposed that uncoupling protein-2 (UCP2) may limit oxidative stress by reducing ROS production, but little is known of UCP2 expression in placenta. Here we measured placental UCP2, SOD-1, SOD-2 and CAT mRNA expression (by qRT–PCR) in normal gestation and after glucocorticoid-induced IUGR. The latter was included because glucocorticoids can increase oxidative stress in other tissues, and placental glucocorticoid exposure is elevated in both PE and IUGR. Placentas were collected on days 16 and 22 of normal pregnancy (term = day 23) and on day 22 after dexamethasone treatment (0.75 mg/mL in drinking water from day 13). The two morphologically-distinct regions of the placenta, the junctional (JZ) and labyrinth (LZ) zones, were analysed separately because effectively all growth occurs in the LZ over this period. Expression of UCP2 in LZ exceeded that in JZ (P < 0.001) and increased in both zones between days 16 and 22 (LZ: 2.0-fold; JZ: 3.2-fold). Dexamethasone treatment reduced UCP2 in LZ (44%; P < 0.05) but not in JZ. SOD1 and SOD2 increased with gestational age in LZ (P < 0.01) and JZ (P < 0.05), but neither were affected by dexamethasone. CAT expression was higher (2.4-fold, P < 0.001) in LZ compared with JZ but did not change with gestational age or dexamethasone. In summary, these data suggest that endogenous protection against oxidative stress increases in the rat placenta during late pregnancy. Moreover, this protection may be compromised by reduced placental UCP2 expression in a model of glucocorticoid-induced IUGR.


Hypertension ◽  
2015 ◽  
Vol 66 (suppl_1) ◽  
Author(s):  
Speranza Rubattu ◽  
Maria Cotugno ◽  
Franca Bianchi ◽  
Sara Di Castro ◽  
Rosita Stanzione ◽  
...  

Mitochondrial dysfunction causes severe cellular derangements potentially underlying tissue injury and consequent diseases. Evidence of a direct involvement of mitochondrial dysfunction in hypertensive target organ damage is still poor. The gene encoding Uncoupling Protein 2 (UCP2), a inner mitochondrial membrane protein, maps inside stroke QTL/STR1 in stroke prone spontaneously hypertensive rat (SHRSP). We explored the role of UCP2 in stroke pathogenesis of SHRSP. Male SHRSP, stroke resistant SHR (SHRSR) and reciprocal STR1/congenic rats were fed with stroke permissive Japanese style diet (JD). A group of SHRSP received JD plus fenofibrate (150 mg/kg/die). Rats were sacrificed at stroke occurrence. Additional SHRSR and SHRSP rats were sacrificed at 1, 3, 6, 12 months of age upon regular diet. SBP, BW, proteinuria, stroke signs were monitored. Brains were used for molecular analysis (UCP2 gene and protein expression, Nf-kB protein expression, oxidative stress quantification) and for histological analyses. As a result, brain UCP2 expression was reduced to 20% by JD only in SHRSP (showing 100% stroke occurrence by 7 weeks of JD). Fenofibrate protected SHRSP from stroke and upregulated brain UCP2 (+ 100%). Congenic rats carrying STR1/QTL showed increased (+100%) brain UCP2 expression, as compared to SHRSP, when resistant to stroke, and, viceversa, decreased (-50%) brain UCP2 levels, as compared to SHRSR, when susceptible to stroke. Brain UCP2 expression progressively decreased with aging only in SHRSP, down to 15% level at one year of age (when SHRSP showed spontaneous stroke). Both brain Nf-kB expression and oxidative stress levels increased when UCP2 expression was downregulated, and viceversa. Histological analysis showed both ischemic and haemorrhagic lesions at stroke occurrence. Our results highlight a role of UCP2 in stroke predisposition associated to hypertension in an animal model of complex human disease.


2008 ◽  
Vol 18 (1) ◽  
pp. 7-14 ◽  
Author(s):  
Jeffrey W. Stephens ◽  
Sukhbir S. Dhamrait ◽  
Ali R. Mani ◽  
Jayshree Acharya ◽  
Kevin Moore ◽  
...  

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