Mitochondrial proton leak rates in the slow, oxidative myotomal muscle and liver of the endothermic shortfin mako shark (Isurus oxyrinchus)and the ectothermic blue shark (Prionace glauca) and leopard shark(Triakis semifasciata)

Duong, Cindy A.; Sepúlveda, Chugey A.; Graham, John L.; Dickson, Kathryn A.

doi:10.1242/jeb.02317

Cited by 21 publications

(6 citation statements)

References 45 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Rates of proton leak in A. limnaeus adult liver and in actively developing embryos (Fig. 5) are comparable to those reported for liver mitochondria from the killiWsh F. heteroclitus (Fangue et al 2009), common carp (Jastroch et al 2007), and shark (Duong et al 2006). In addition, the contribution of proton leak to overall rates of oxygen consumption in mitochondria isolated from adult liver are consistent with previously published data and varied from 10 to 15% with glutamate/malate provided as substrate.…”

Section: Mitochondrial Proton Leak and Metabolic Dormancysupporting

confidence: 91%

Mitochondrial physiology of diapausing and developing embryos of the annual killifish Austrofundulus limnaeus: implications for extreme anoxia tolerance

Duerr

Podrabsky

2010

J Comp Physiol B

View full text Add to dashboard Cite

Diapausing embryos of the annual killifish Austrofundulus limnaeus have the highest reported anoxia tolerance of any vertebrate and previous studies indicate modified mitochondrial physiology likely supports anoxic metabolism. Functional mitochondria isolated from diapausing and developing embryos of the annual killifish exhibited VO(2), respiratory control ratios (RCR), and P:O ratios consistent with those obtained from other ectothermic vertebrate species. Reduced oxygen consumption associated with dormancy in whole animal respiration rates are correlated with maximal respiration rates of mitochondria isolated from diapausing versus developing embryos. P:O ratios for developing embryos were similar to those obtained from adult liver, but were diminished in mitochondria from diapausing embryos suggesting decreased oxidative efficiency. Proton leak in adult liver corresponded with that of developing embryos but was elevated in mitochondria isolated from diapausing embryos. In metabolically suppressed diapause II embryos, over 95% of the mitochondrial oxygen consumption is accounted for by proton leak across the inner mitochondrial membrane. Decreased activity of mitochondrial respiratory chain complexes correlates with diminished oxidative capacity of isolated mitochondria, especially during diapause. Respiratory complexes exhibited suppressed activity in mitochondria with the ATP synthase exhibiting the greatest inhibition during diapause II. Mitochondria isolated from diapause II embryos are not poised to produce ATP, but rather to shuttle carbon and electrons through the Kreb's cycle while minimizing the generation of a proton motive force. This particular mitochondrial physiology is likely a mechanism to avoid production of reactive oxygen species during large-scale changes in flux through oxidative phosphorylation pathways associated with metabolic transitions into and out of dormancy and anoxia.

show abstract

Section: Mitochondrial Proton Leak and Metabolic Dormancysupporting

confidence: 91%

Mitochondrial physiology of diapausing and developing embryos of the annual killifish Austrofundulus limnaeus: implications for extreme anoxia tolerance

Duerr

Podrabsky

2010

J Comp Physiol B

View full text Add to dashboard Cite

show abstract

“…Efforts have been recently made to assess the clinical relevance of noninvasive tests including the evaluation of mtDNA or mitochondrial functions in peripheral blood mononuclear cells for the diagnosis of antiretroviral-associated toxicity (reviewed by Duong et al, 2005) [62]. In addition, COX subunit I labeling has been suggested to be a valuable tool for the diagnosis of mitochondrial liver disease in HIV patients [63]. Efavirenz (EFV) is the most widely used NNRTIs applied in HAART.…”

Section: Role Of Mitochondria In Hiv-associated Fatty Liver Diseasementioning

confidence: 99%

Role of Mitochondria in HIV Infection and Associated Metabolic Disorders: Focus on Nonalcoholic Fatty Liver Disease and Lipodystrophy Syndrome

Pérez-Matute

Pérez‐Martínez

Blanco

et al. 2013

Oxidative Medicine and Cellular Longevity

View full text Add to dashboard Cite

Highly active antiretroviral therapy (HAART) has considerably improved the prognosis of HIV-infected patients. However, prolonged use of HAART has been related to long-term adverse events that can compromise patient health such as HIV-associated lipodystrophy syndrome (HALS) and nonalcoholic fatty liver disease (NAFLD). There is consistent evidence for a central role of mitochondrial dysfunction in these pathologies. Nucleotide reverse transcriptase inhibitors (NRTIs) have been described to be mainly responsible for mitochondrial dysfunction in adipose tissue and liver although nonnucleoside transcriptase inhibitors (NNRTIs) or protease inhibitors (PIs) have also showed mitochondrial toxicity, which is a major concern for the selection and the long-term adherence to a particular therapy. Several mechanisms explain these deleterious effects of HAART on mitochondria, and evidence points to other mechanisms beyond the “Pol-γ hypothesis.” HIV infection has also direct effects on mitochondria. In addition to the negative effects described for HIV itself and/or HAART on mitochondria, HIV-infected patients are more prone to develop a premature aging and, therefore, to present an increased oxidative state that could lead to the development of these metabolic disturbances observed in HIV-infected patients.

show abstract

“…However, it is unlikely that UCPs of most water breathing ectotherms have a role in thermoregulation; because of the high thermal capacity of water, any metabolic heat is instantly lost over the gills. Only in tuna and shark red muscle, some heat is conserved inside the body causing regional endothermy that has been related to proton leak (Stevens et al, 2000;Duong et al, 2006). In their habitats, ectothermal fish can experience wide fluctuations of ambient water temperature, and as the rate of their metabolic reactions follows temperature passively, they have to adjust metabolic energy supply according to energy demand (Hochachka and Somero, 2002;Pörtner et al, 2005).…”

Section: Introductionmentioning

confidence: 99%

Thermal sensitivity of uncoupling protein expression in polar and temperate fish

Mark

Lucassen

Pörtner

2006

Comparative Biochemistry and Physiology Part D: Genomics and Pr

View full text Add to dashboard Cite

Uncoupling proteins (UCP), capable of increasing proton leakage across the inner mitochondrial membrane, may play a role in the temperature-dependent setting of energy turnover in animals (and their mitochondria). Therefore, the genes and expression of fish UCP were investigated in the Antarctic eelpout Pachycara brachycephalum and a temperate confamilial species, the common eelpout Zoarces viviparus. UCP full-length cDNA was amplified from liver and muscle using RT-PCR and rapid amplification of cDNA ends (RACE). The fish UCP mRNA consists of 1906 bp in P. brachycephalum and of 1876 bp in Z. viviparus. Both zoarcid sequences contain open reading frames of 939 bp, encoding 313 amino acids, with 98% and 99% identity, respectively. Protein sequences of zoarcid UCP are closest related to fish and mammalian UCP2. For analysis of temperature-dependent expression common eelpouts were cold-acclimated from 10°C to 2°C and Antarctic eelpouts were warm-acclimated from 0°C to 5°C. Identical cDNA probes for both species were developed to investigate fish UCP mRNA expression, and protein expression levels were detected by Western Blot in the enriched membrane fraction. During cold-acclimation in Z. viviparus, mRNA levels increased by a factor up to 2.0, protein levels increased up to 1.5, in line with mitochondrial proliferation during cold-acclimation. Despite decreased mitochondrial protein content, in Antarctic eelpout UCP levels rose upon warm acclimation by a factor up to 2.0 (mRNA) and 1.6 (protein), respectively. Besides the ongoing discussion of UCP function in vertebrates, the data are indicative of a significant role of fish UCP in thermal adaptation of fish mitochondria.

show abstract

Mitochondrial proton leak rates in the slow, oxidative myotomal muscle and liver of the endothermic shortfin mako shark (Isurus oxyrinchus)and the ectothermic blue shark (Prionace glauca) and leopard shark(Triakis semifasciata)

Abstract: Mitochondrial proton leak rates in the slow, oxidative myotomal muscle and liver of the endothermic shortfin mako shark (Isurus oxyrinchus) and the ectothermic blue shark (Prionace glauca) and leopard shark (Triakis semifasciata)

Cited by 21 publications

References 45 publications

Mitochondrial physiology of diapausing and developing embryos of the annual killifish Austrofundulus limnaeus: implications for extreme anoxia tolerance

Mitochondrial physiology of diapausing and developing embryos of the annual killifish Austrofundulus limnaeus: implications for extreme anoxia tolerance

Role of Mitochondria in HIV Infection and Associated Metabolic Disorders: Focus on Nonalcoholic Fatty Liver Disease and Lipodystrophy Syndrome

Thermal sensitivity of uncoupling protein expression in polar and temperate fish

Contact Info

Product

Resources

About