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Nicholatos JW, Robinette TM, Tata SVP, Yordy JD, Francisco AB, Platov M, Yeh TK, Ilkayeva OR, Huynh FK, Dokukin M, Volkov D, Weinstein MA, Boyko AR, Miller RA, Sokolov I, Hirschey MD, Libert S. Cellular energetics and mitochondrial uncoupling in canine aging. GeroScience 2019; 41:229-242. [PMID: 30937823 DOI: 10.1007/s11357-019-00062-6] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.8] [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: 11/02/2018] [Accepted: 03/18/2019] [Indexed: 01/02/2023] Open
Abstract
The first domesticated companion animal, the dog, is currently represented by over 190 unique breeds. Across these numerous breeds, dogs have exceptional variation in lifespan (inversely correlated with body size), presenting an opportunity to discover longevity-determining traits. We performed a genome-wide association study on 4169 canines representing 110 breeds and identified novel candidate regulators of longevity. Interestingly, known functions within the identified genes included control of coat phenotypes such as hair length, as well as mitochondrial properties, suggesting that thermoregulation and mitochondrial bioenergetics play a role in lifespan variation. Using primary dermal fibroblasts, we investigated mitochondrial properties of short-lived (large) and long-lived (small) dog breeds. We found that cells from long-lived breeds have more uncoupled mitochondria, less electron escape, greater respiration, and capacity for respiration. Moreover, our data suggest that long-lived breeds have higher rates of catabolism and β-oxidation, likely to meet elevated respiration and electron demand of their uncoupled mitochondria. Conversely, cells of short-lived (large) breeds may accumulate amino acids and fatty acid derivatives, which are likely used for biosynthesis and growth. We hypothesize that the uncoupled metabolic profile of long-lived breeds likely stems from their smaller size, reduced volume-to-surface area ratio, and therefore a greater need for thermogenesis. The uncoupled energetics of long-lived breeds lowers reactive oxygen species levels, promotes cellular stress tolerance, and may even prevent stiffening of the actin cytoskeleton. We propose that these cellular characteristics delay tissue dysfunction, disease, and death in long-lived dog breeds, contributing to canine aging diversity.
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Affiliation(s)
- Justin W Nicholatos
- Department of Biomedical Sciences, Cornell University, Ithaca, NY, 14850, USA.
| | - Timothy M Robinette
- Department of Biomedical Sciences, Cornell University, Ithaca, NY, 14850, USA
| | - Saurabh V P Tata
- Department of Biomedical Sciences, Cornell University, Ithaca, NY, 14850, USA
| | - Jennifer D Yordy
- Department of Biomedical Sciences, Cornell University, Ithaca, NY, 14850, USA
| | - Adam B Francisco
- Department of Biomedical Sciences, Cornell University, Ithaca, NY, 14850, USA
| | - Michael Platov
- Department of Biomedical Sciences, Cornell University, Ithaca, NY, 14850, USA
| | - Tiffany K Yeh
- Department of Biomedical Sciences, Cornell University, Ithaca, NY, 14850, USA
| | - Olga R Ilkayeva
- Duke Molecular Physiology Institute and Sarah W. Stedman Nutrition and Metabolism Center, Duke University Medical Center, Durham, NC, 27701, USA
| | - Frank K Huynh
- Duke Molecular Physiology Institute and Sarah W. Stedman Nutrition and Metabolism Center, Duke University Medical Center, Durham, NC, 27701, USA
| | - Maxim Dokukin
- Department of Mechanical Engineering, Tufts University, Medford, MA, 02155, USA
| | - Dmytro Volkov
- Department of Mechanical Engineering, Tufts University, Medford, MA, 02155, USA
| | - Michael A Weinstein
- Department of Biomedical Engineering, Tufts University, Medford, MA, 02155, USA
| | - Adam R Boyko
- Department of Biomedical Sciences, Cornell University, Ithaca, NY, 14850, USA
| | - Richard A Miller
- Department of Pathology, University of Michigan, Ann Arbor, MI, 48109, USA
| | - Igor Sokolov
- Department of Mechanical Engineering, Tufts University, Medford, MA, 02155, USA.,Department of Biomedical Engineering, Tufts University, Medford, MA, 02155, USA
| | - Matthew D Hirschey
- Duke Molecular Physiology Institute and Sarah W. Stedman Nutrition and Metabolism Center, Duke University Medical Center, Durham, NC, 27701, USA
| | - Sergiy Libert
- Department of Biomedical Sciences, Cornell University, Ithaca, NY, 14850, USA.
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Abstract
PURPOSE This study examined the pharmacokinetic interaction between 2',3'-dideoxyinosine (ddI) and pentamidine. BACKGROUND ddI and pentamidine are often coadministered to patients with acquired immunodeficiency syndrome, and are both associated with pancreatic toxicity. Information on potential interaction would be useful to assess the need for dose modification and the basis of the higher incidence of pancreatic toxicity associated with coadministration of the two drugs. METHODS ddI (200 mg/kg) and pentamidine (10 mg/kg) were administered by continuous infusion to rats over 3 hr, either alone or concomitantly. Drug analysis was by high pressure liquid chromatography with UV or fluorescence detection, or by radioimmunoassay. RESULTS Pentamidine coadministration significantly increased the apparent volume of distribution at steady state of ddI from 1.4 to 3.4 l/kg (p = 0.004), and increased the mean residence time from 36.3 to 50.0 min (p = 0.015). Pentamidine enhanced the distribution of ddI from plasma into pancreas (p = 0.001) and muscle (p = 0.026). ddI distribution into spleen and liver was also increased, with differences approaching statistical significance (p = 0.08 and 0.06, respectively). In contrast, ddI coadministration did not affect the total body clearance but increased the urinary excretion and the renal clearance of pentamidine by about 5-fold (p = 0.0003). CONCLUSIONS These data indicate that pentamidine increased the distribution of ddI into pancreas and muscle, whereas ddI increased the renal elimination of pentamidine.
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Affiliation(s)
- T K Yeh
- Division of Pharmaceutics and Pharmaceutical Chemistry, Ohio State University, Columbus 43210, USA
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Abstract
This report describes the analysis of pentamidine by isocratic reversed-phase high-performance liquid chromatography (HPLC) using a commercially available compound (melphalan) as the external standard. Previously described assays use ion-pairing HPLC, an internal standard (hexamidine) that is not readily available, and require a relatively large sample size. In the present assay, pentamidine was extracted from plasma using solid-phase extraction and was analyzed using a C18 column and a mobile phase containing 18% acetonitrile, 2% methanol, 0.2 M ammonium acetate and 0.5% triethylamine. The identity of the eluting peaks was verified using a diode array detector. The extraction yield of pentamidine was 82%. The limit of detection was 8.6 ng/ml with a sample size of 100 microliters. The inter-day and intra-day coefficients of variation ranged between 0.3% and 10% with an average of 5%. This method was applied to study the pharmacokinetics of pentamidine in rodents.
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Affiliation(s)
- T K Yeh
- Division of Pharmaceutics and Pharmaceutical Chemistry, College of Pharmacy, Ohio State University, Columbus 43210
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