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Guo S, Yang W, Chen D, Ren B, Guo L, Wang X, Xie W, Fan S, Artigas Ramirez MD, Han Y, Yuan Z, Zhang H, Weng Q. The effects of low ambient temperature on steroidogenesis and mitochondrial functions in the testes of wild ground squirrels (Spermophilus dauricus). Comp Biochem Physiol A Mol Integr Physiol 2024; 290:111585. [PMID: 38228267 DOI: 10.1016/j.cbpa.2024.111585] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/13/2023] [Revised: 01/11/2024] [Accepted: 01/12/2024] [Indexed: 01/18/2024]
Abstract
Seasonal reproduction is a widely used breeding strategy in wildlife, especially vertebrates inhabiting temperate regions. Generally, ambient temperature is considered a significant factor influencing the reproductive status of animals. In the present study, wild ground squirrels (Spermophilus dauricus), typical seasonal breeders, were used as an animal model to investigate the mechanism behind the impact of low ambient temperature on testicular function. To simulate the winter environment of wild ground squirrels, we lowered the temperature gradient in the rearing environment to 4 °C. At sampling, the body surface temperature of the squirrels reared under normal ambient temperature (22 °C, NAT group) and the low ambient temperature (4 °C, LAT group) were 31.5 °C and 22.8 °C, respectively. Subsequently, we conducted immunohistochemical assays, qPCR, and enzyme-linked immunosorbent assays (ELISA) to examine the variations in testicular functions, as well as the dynamics and functions of mitochondria, in the squirrels of NAT and LAT groups. As a result, the levels of positive immunostaining for PCNA, P21, and P27 were significantly lower in the testes of LAT group, while the levels of immunostaining for Cleaved Caspase-3 and TUNEL were significantly higher. In addition, the low-temperature treatment reduced the expression level of steroidogenesis-related genes, including LHR, FSHR, GATA-4, P450scc, and P450arom, and decreased the testosterone concentration. Moreover, markers of mitochondrial fission and fusion, DRP1 and MFN2, respectively, were increased in the testes of LAT group. Additionally, the mRNA level of SOD1 was notably higher in the testes of LAT group. In conclusion, the low ambient temperature inhibited spermatogenesis, steroidogenesis, as well as mitochondrial dynamics and functions in the testes of wild ground squirrels.
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Affiliation(s)
- Shiman Guo
- Laboratory of Animal Physiology, College of Biological Sciences and Technology, Beijing Forestry University, Beijing 100083, China
| | - Wenjin Yang
- Laboratory of Animal Physiology, College of Biological Sciences and Technology, Beijing Forestry University, Beijing 100083, China
| | - Di Chen
- Laboratory of Animal Physiology, College of Biological Sciences and Technology, Beijing Forestry University, Beijing 100083, China
| | - Baolong Ren
- Laboratory of Animal Physiology, College of Biological Sciences and Technology, Beijing Forestry University, Beijing 100083, China
| | - Li Guo
- Laboratory of Animal Physiology, College of Biological Sciences and Technology, Beijing Forestry University, Beijing 100083, China
| | - Xi Wang
- Laboratory of Animal Physiology, College of Biological Sciences and Technology, Beijing Forestry University, Beijing 100083, China
| | - Wenqian Xie
- Laboratory of Animal Physiology, College of Biological Sciences and Technology, Beijing Forestry University, Beijing 100083, China
| | - Sijie Fan
- Laboratory of Animal Physiology, College of Biological Sciences and Technology, Beijing Forestry University, Beijing 100083, China
| | - Maria Daniela Artigas Ramirez
- Laboratory of Animal Physiology, College of Biological Sciences and Technology, Beijing Forestry University, Beijing 100083, China
| | - Yingying Han
- Laboratory of Animal Physiology, College of Biological Sciences and Technology, Beijing Forestry University, Beijing 100083, China
| | - Zhengrong Yuan
- Laboratory of Animal Physiology, College of Biological Sciences and Technology, Beijing Forestry University, Beijing 100083, China
| | - Haolin Zhang
- Laboratory of Animal Physiology, College of Biological Sciences and Technology, Beijing Forestry University, Beijing 100083, China.
| | - Qiang Weng
- Laboratory of Animal Physiology, College of Biological Sciences and Technology, Beijing Forestry University, Beijing 100083, China.
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2
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Wang Z, Wang X, Chen Y, Wang C, Chen L, Jiang M, Liu X, Zhang X, Feng Y, Xu J. Loss and recovery of myocardial mitochondria in mice under different tail suspension time: Apoptosis and mitochondrial fission, fusion and autophagy. Exp Physiol 2023; 108:1189-1202. [PMID: 37565298 PMCID: PMC10988507 DOI: 10.1113/ep090518] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/18/2022] [Accepted: 07/25/2023] [Indexed: 08/12/2023]
Abstract
Long-term weightlessness in animals can cause changes in myocardial structure and function, in which mitochondria play an important role. Here, a tail suspension (TS) Kunming mouse (Mus musculus) model was used to simulate the effects of weightlessness on the heart. We investigated the effects of 2 and 4 weeks of TS (TS2 and TS4) on myocardial mitochondrial ultrastructure and oxidative respiratory function and on the molecular mechanisms of apoptosis and mitochondrial fission, autophagy and fusion-related signalling. Our study revealed significant changes in the ultrastructural features of cardiomyocytes in response to TS. The results showed: (1) mitochondrial swelling and disruption of cristae in TS2, but mitochondrial recovery and denser cristae in TS4; (2) an increase in the total number of mitochondria and number of sub-mitochondria in TS4; (3) no significant changes in the nuclear ultrastructure or DNA fragmentation among the two TS groups and the control group; (4) an increase in the bax/bcl-2 protein levels in the two TS groups, indicating increased activation of the bax-mediated apoptosis pathway; (5) no change in the phosphorylation ratio of dynamin-related protein 1 in the two TS groups; (6) an increase in the protein levels of optic atrophy 1 and mitofusin 2 in the two TS groups; and (7) in comparison to the TS2 group, an increase in the phosphorylation ratio of parkin and the ratio of LC3II to LC3I in TS4, suggesting an increase in autophagy. Taken together, these findings suggest that mitochondrial autophagy and fusion levels increased after 4 weeks of TS, leading to a restoration of the bax-mediated myocardial apoptosis pathway observed after 2 weeks of TS. NEW FINDINGS: What is the central question of this study? What are the effects of 2 and 4 weeks of tail suspension on myocardial mitochondrial ultrastructure and oxidative respiratory function and on the molecular mechanisms of apoptosis and mitochondrial fission, autophagy and fusion-related signalling? What is the main finding and its importance? Increased mitochondrial autophagy and fusion levels after 4 weeks of tail suspension help to reshape the morphology and increase the number of myocardial mitochondria.
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Affiliation(s)
- Zhe Wang
- College of Life SciencesQufu Normal UniversityQufuShandongChina
| | - Xing‐Chen Wang
- College of Life SciencesQufu Normal UniversityQufuShandongChina
| | - Ya‐Fei Chen
- College of Life SciencesQufu Normal UniversityQufuShandongChina
| | - Chuan‐Li Wang
- College of Life SciencesQufu Normal UniversityQufuShandongChina
| | - Le Chen
- College of Life SciencesQufu Normal UniversityQufuShandongChina
| | - Ming‐Yue Jiang
- College of Life SciencesQufu Normal UniversityQufuShandongChina
| | - Xi‐Wei Liu
- College of Life SciencesQufu Normal UniversityQufuShandongChina
| | - Xiao‐Xuan Zhang
- College of Life SciencesQufu Normal UniversityQufuShandongChina
| | - Yong‐Zhen Feng
- College of Life SciencesQufu Normal UniversityQufuShandongChina
| | - Jin‐Hui Xu
- College of Life SciencesQufu Normal UniversityQufuShandongChina
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de Wit L, Hamberg MR, Ross AM, Goris M, Lie FF, Ruf T, Giroud S, Henning RH, Hut RA. Temperature Effects on DNA Damage during Hibernation. Physiol Biochem Zool 2023; 96:144-152. [PMID: 36921268 DOI: 10.1086/722904] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
Abstract
AbstractDuring multiday torpor, deep-hibernating mammals maintain a hypometabolic state where heart rate and ventilation are reduced to 2%-4% of euthermic rates. It is hypothesized that this ischemia-like condition may cause DNA damage through reactive oxygen species production. The reason for intermittent rewarming (arousal) during hibernation might be to repair the accumulated DNA damage. Because increasing ambient temperatures (Ta's) shortens torpor bout duration, we hypothesize that hibernating at higher Ta's will result in a faster accumulation of genomic DNA damage. To test this, we kept 39 male and female garden dormice at a Ta of either 5°C or 10°C and obtained tissue at 1, 4, and 8 d in torpor to assess DNA damage and recruitment of DNA repair markers in splenocytes. DNA damage in splenocytes measured by comet assay was significantly higher in almost all torpor groups than in summer euthermic groups. Damage accumulates in the first days of torpor at Ta=5°C (between days 1 and 4) but not at Ta=10°C. At the higher Ta, DNA damage is high at 24 h in torpor, indicating either a faster buildup of DNA damage at higher Ta's or an incomplete repair during arousals in dormice. At 5°C, recruitment of the DNA repair protein 53BP1 paralleled the increase in DNA damage over time during torpor. In contrast, after 1 d in torpor at 10°C, DNA damage levels were high, but 53BP1 was not recruited to the nuclear DNA yet. The data suggest a potential mismatch in the DNA damage/repair dynamics during torpor at higher Ta's.
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Ali A, Wang Y, Wu L, Yang G. Gasotransmitter signaling in energy homeostasis and metabolic disorders. Free Radic Res 2020; 55:83-105. [PMID: 33297784 DOI: 10.1080/10715762.2020.1862827] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Abstract
Gasotransmitters are small molecules of gases, including nitric oxide (NO), hydrogen sulfide (H2S), and carbon monoxide (CO). These three gasotransmitters can be endogenously produced and regulate a wide range of pathophysiological processes by interacting with specific targets upon diffusion in the biological media. By redox and epigenetic regulation of various physiological functions, NO, H2S, and CO are critical for the maintenance of intracellular energy homeostasis. Accumulated evidence has shown that these three gasotransmitters control ATP generation, mitochondrial biogenesis, glucose metabolism, insulin sensitivity, lipid metabolism, and thermogenesis, etc. Abnormal generation and metabolism of NO, H2S, and/or CO are involved in various abnormal metabolic diseases, including obesity, diabetes, and dyslipidemia. In this review, we summarized the roles of NO, H2S, and CO in the regulation of energy homeostasis as well as their involvements in the metabolism of dysfunction-related diseases. Understanding the interaction among these gasotransmitters and their specific molecular targets are very important for therapeutic applications.
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Affiliation(s)
- Amr Ali
- Department of Chemistry and Biochemistry, Laurentian University, Sudbury, Canada.,Cardiovascular and Metabolic Research Unit, Laurentian University, Sudbury, Canada
| | - Yuehong Wang
- Department of Chemistry and Biochemistry, Laurentian University, Sudbury, Canada.,Cardiovascular and Metabolic Research Unit, Laurentian University, Sudbury, Canada
| | - Lingyun Wu
- Cardiovascular and Metabolic Research Unit, Laurentian University, Sudbury, Canada.,School of Human Kinetics, Laurentian University, Sudbury, Canada.,Health Science North Research Institute, Sudbury, Canada
| | - Guangdong Yang
- Department of Chemistry and Biochemistry, Laurentian University, Sudbury, Canada.,Cardiovascular and Metabolic Research Unit, Laurentian University, Sudbury, Canada
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Wang Z, Xu JH, Mou JJ, Kong XT, Zou JW, Xue HL, Wu M, Xu LX. Novel ultrastructural findings on cardiac mitochondria of huddling Brandt's voles in mild cold environment. Comp Biochem Physiol A Mol Integr Physiol 2020; 249:110766. [DOI: 10.1016/j.cbpa.2020.110766] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/19/2020] [Revised: 06/25/2020] [Accepted: 07/09/2020] [Indexed: 10/23/2022]
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6
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Hibernator-Derived Cells Show Superior Protection and Survival in Hypothermia Compared to Non-Hibernator Cells. Int J Mol Sci 2020; 21:ijms21051864. [PMID: 32182837 PMCID: PMC7084219 DOI: 10.3390/ijms21051864] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/30/2020] [Revised: 03/03/2020] [Accepted: 03/04/2020] [Indexed: 02/07/2023] Open
Abstract
Mitochondrial failure is recognized to play an important role in a variety of diseases. We previously showed hibernating species to have cell-autonomous protective mechanisms to resist cellular stress and sustain mitochondrial function. Here, we set out to detail these mitochondrial features of hibernators. We compared two hibernator-derived cell lines (HaK and DDT1MF2) with two non-hibernating cell lines (HEK293 and NRK) during hypothermia (4 °C) and rewarming (37 °C). Although all cell lines showed a strong decrease in oxygen consumption upon cooling, hibernator cells maintained functional mitochondria during hypothermia, without mitochondrial permeability transition pore (mPTP) opening, mitochondrial membrane potential decline or decreased adenosine triphosphate (ATP) levels, which were all observed in both non-hibernator cell lines. In addition, hibernator cells survived hypothermia in the absence of extracellular energy sources, suggesting their use of an endogenous substrate to maintain ATP levels. Moreover, hibernator-derived cells did not accumulate reactive oxygen species (ROS) damage and showed normal cell viability even after 48 h of cold-exposure. In contrast, non-hibernator cells accumulated ROS and showed extensive cell death through ferroptosis. Understanding the mechanisms that hibernators use to sustain mitochondrial activity and counteract damage in hypothermic circumstances may help to define novel preservation techniques with relevance to a variety of fields, such as organ transplantation and cardiac arrest.
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Vogelaar PC, Roorda M, de Vrij EL, Houwertjes MC, Goris M, Bouma H, van der Graaf AC, Krenning G, Henning RH. The 6-hydroxychromanol derivative SUL-109 ameliorates renal injury after deep hypothermia and rewarming in rats. Nephrol Dial Transplant 2019; 33:2128-2138. [PMID: 29660027 DOI: 10.1093/ndt/gfy080] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/19/2017] [Accepted: 03/03/2018] [Indexed: 12/13/2022] Open
Abstract
Background Mitochondrial dysfunction plays an important role in kidney damage in various pathologies, including acute and chronic kidney injury and diabetic nephropathy. In addition to the well-studied ischaemia/reperfusion (I/R) injury, hypothermia/rewarming (H/R) also inflicts acute kidney injury. Substituted 6-hydroxychromanols are a novel class of mitochondrial medicines that ameliorate mitochondrial oxidative stress and protect the mitochondrial network. To identify a novel 6-hydroxychromanol that protects mitochondrial structure and function in the kidney during H/R, we screened multiple compounds in vitro and subsequently assessed the efficacy of the 6-hydroxychromanol derivatives SUL-109 and SUL-121 in vivo to protect against kidney injury after H/R in rats. Methods Human proximal tubule cell viability was assessed following exposure to H/R for 48/4 h in the presence of various 6-hydroxychromanols. Selected compounds (SUL-109, SUL-121) or vehicle were administered to ketamine-anaesthetized male Wistar rats (IV 135 µg/kg/h) undergoing H/R at 15°C for 3 h followed by rewarming and normothermia for 1 h. Metabolic parameters and body temperature were measured throughout. In addition, renal function, renal injury, histopathology and mitochondrial fitness were assessed. Results H/R injury in vitro lowered cell viability by 94 ± 1%, which was counteracted dose-dependently by multiple 6-hydroxychomanols derivatives. In vivo, H/R in rats showed kidney injury molecule 1 expression in the kidney and tubular dilation, accompanied by double-strand DNA breaks and protein nitrosylation. SUL-109 and SUL-121 ameliorated tubular kidney damage, preserved mitochondrial mass and maintained cortical adenosine 5'-triphosphate (ATP) levels, although SUL-121 did not reduce protein nitrosylation. Conclusions The substituted 6-hydroxychromanols SUL-109 and SUL-121 ameliorate kidney injury during in vivo H/R by preserving mitochondrial mass, function and ATP levels. In addition, both 6-hydroxychromanols limit DNA damage, but only SUL-109 also prevented protein nitrosylation in tubular cells. Therefore SUL-109 offers a promising therapeutic strategy to preserve kidney mitochondrial function.
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Affiliation(s)
- Pieter C Vogelaar
- Department of Clinical Pharmacy and Pharmacology, University Medical Center Groningen, University of Groningen, Groningen, The Netherlands
- Sulfateq B.V., Groningen, The Netherlands
| | - Maurits Roorda
- Department of Clinical Pharmacy and Pharmacology, University Medical Center Groningen, University of Groningen, Groningen, The Netherlands
| | - Edwin L de Vrij
- Department of Clinical Pharmacy and Pharmacology, University Medical Center Groningen, University of Groningen, Groningen, The Netherlands
| | - Martin C Houwertjes
- Department of Anesthesiology, University Medical Center Groningen, University of Groningen, Groningen, The Netherlands
| | - Maaike Goris
- Department of Clinical Pharmacy and Pharmacology, University Medical Center Groningen, University of Groningen, Groningen, The Netherlands
| | - Hjalmar Bouma
- Department of Clinical Pharmacy and Pharmacology, University Medical Center Groningen, University of Groningen, Groningen, The Netherlands
- Department of Internal Medicine, University Medical Center Groningen, University of Groningen, Groningen, The Netherlands
| | | | - Guido Krenning
- Sulfateq B.V., Groningen, The Netherlands
- Cardiovascular Regenerative Medicine, Department of Pathology and Medical Biology, University Medical Center Groningen, University of Groningen, Groningen, The Netherlands
| | - Robert H Henning
- Department of Clinical Pharmacy and Pharmacology, University Medical Center Groningen, University of Groningen, Groningen, The Netherlands
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8
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Soo E, Welch A, Marsh C, McKay DB. Molecular strategies used by hibernators: Potential therapeutic directions for ischemia reperfusion injury and preservation of human donor organs. Transplant Rev (Orlando) 2019; 34:100512. [PMID: 31648853 DOI: 10.1016/j.trre.2019.100512] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/08/2019] [Revised: 10/02/2019] [Accepted: 10/03/2019] [Indexed: 12/12/2022]
Affiliation(s)
- E Soo
- Scripps Research, Department of Immunology and Molecular Biology, 10550 North Torrey Pines Rd, La Jolla, CA, United States of America; Scripps Clinic and Green Hospital, Department of Medicine and Surgery, 10660 North Torrey Pines Rd, La Jolla, CA, United States of America
| | - A Welch
- Scripps Research, Department of Immunology and Molecular Biology, 10550 North Torrey Pines Rd, La Jolla, CA, United States of America
| | - C Marsh
- Scripps Clinic and Green Hospital, Department of Medicine and Surgery, 10660 North Torrey Pines Rd, La Jolla, CA, United States of America
| | - D B McKay
- Scripps Research, Department of Immunology and Molecular Biology, 10550 North Torrey Pines Rd, La Jolla, CA, United States of America; Scripps Clinic and Green Hospital, Department of Medicine and Surgery, 10660 North Torrey Pines Rd, La Jolla, CA, United States of America.
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9
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Abstract
Machine perfusion is a hot topic in liver transplantation and several new perfusion concepts are currently developed. Prior to introduction into routine clinical practice, however, such perfusion approaches need to demonstrate their impact on liver function, post-transplant complications, utilization rates of high-risk organs, and cost benefits. Therefore, based on results of experimental and clinical studies, the community has to recognize the limitations of this technology. In this review, we summarize current perfusion concepts and differences between protective mechanisms of ex- and in-situ perfusion techniques. Next, we discuss which graft types may benefit most from perfusion techniques, and highlight the current understanding of liver viability testing. Finally, we present results from recent clinical trials involving machine liver perfusion, and analyze the value of different outcome parameters, currently used as endpoints for randomized controlled trials in the field.
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Affiliation(s)
- Andrea Schlegel
- Liver Unit, Queen Elizabeth Hospital, University Hospitals Birmingham NHS Foundation Trust, Birmingham, UK.,Centre for Liver and Gastrointestinal Research, Institute of Immunology and Immunotherapy, College of Medical and Dental Sciences, University of Birmingham, Birmingham, UK.,Department of Surgery and Transplantation, University Hospital Zurich, Zurich, Switzerland
| | - Xavier Muller
- Department of Surgery and Transplantation, University Hospital Zurich, Zurich, Switzerland
| | - Philipp Dutkowski
- Department of Surgery and Transplantation, University Hospital Zurich, Zurich, Switzerland
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Orlande HRB, Lutaif NA, Gontijo JAR. Estimation of the kidney metabolic heat generation rate. INTERNATIONAL JOURNAL FOR NUMERICAL METHODS IN BIOMEDICAL ENGINEERING 2019; 35:e3224. [PMID: 31166657 DOI: 10.1002/cnm.3224] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/17/2019] [Revised: 05/11/2019] [Accepted: 05/28/2019] [Indexed: 06/09/2023]
Abstract
Thermogenesis results from the cellular metabolism and has a fundamental role for body thermoregulation in endothermic species. The motivation for this work is the analysis of the kidneys' contribution for thermoregulation. An inverse problem is solved for the estimation of the heat generation rate that results from the metabolic activities in the kidney, by using transient temperature measurements of the urine. The Markov chain Monte Carlo (MCMC) method is applied for the solution of the inverse problem, which presents inherent difficulties associated with low sensitivity of the parameters of main interest that represent the transient heat source term and strong correlation of the remaining model parameters. Such difficulties are dealt with in this work by using a version of the Metropolis-Hastings algorithm that samples the parameters in blocks. Simulated temperature measurements are used for the inverse problem solution, and the convergence of the Markov chains is verified with two different techniques.
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Affiliation(s)
- Helcio R B Orlande
- Department of Mechanical Engineering, Politécnica/COPPE, Federal University of Rio de Janeiro, Rio de Janeiro, Brazil
| | - Nelson Afonso Lutaif
- Department of Medical Clinic, School of Medical Sciences, State University of Campinas-UNICAMP, Campinas, Brazil
| | - José Antonio Rocha Gontijo
- Department of Medical Clinic, School of Medical Sciences, State University of Campinas-UNICAMP, Campinas, Brazil
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Real-time kidney graft perfusion monitoring using infrared imaging during pediatric kidney transplantation. J Pediatr Urol 2019; 15:222.e1-222.e7. [PMID: 31029559 DOI: 10.1016/j.jpurol.2019.03.016] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/23/2018] [Revised: 11/16/2018] [Accepted: 03/20/2019] [Indexed: 10/27/2022]
Abstract
INTRODUCTION Ischemia times in kidney transplantation have shown to be predictive for future graft function. Preservation solutions and anticoagulation protocols have improved the management of pediatric kidney transplantation. Nonetheless, there is no current tool for intra-operative graft monitoring. The aim of this project is to present a novel technique for intra-operative real-time assessment of graft perfusion using a non-invasive infrared camera. METHODS Prospectively, the authors included 10 pediatric patients. Surgical procedure followed their institutional protocol. Infrared imaging was captured at graft preparation, vascular anastomosis, unclamping, and at 30 s, 1, 5, and 10 min after unclamping. Analyzed variables included type of transplant, ischemia and procedure times, type of anastomosis, and results of doppler/ultrasound. Postoperative variables included creatinine levels during first 72 h. Any complications were also recorded. Delta analysis was calculated to establish the variation of temperature after unclamping. RESULTS Average age at transplant was 9.9 years. Five cases were living donor transplants. Mean overall ischemia time was 395.6 (SD 64.4 min). Two patients had poor graft perfusion after unclamping. Of those, one had torsion of the arterial anastomosis and the other was a graft from a donor that required cardiopulmonary resuscitation for 45 min. Thermal imaging showed a correlation of 0.318 between graft temperature change and creatinine decrease. Cut-off delta for temperature for good reperfusion was above 0.2 at 1 min CONCLUSION: Real-time infrared imaging shows to be a promising option for non-invasive graft perfusion monitoring. Initial results show good correlation between intra-operative temperature changes, graft perfusion, and postoperative graft function.
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12
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Barriers and Advances in Kidney Preservation. BIOMED RESEARCH INTERNATIONAL 2018; 2018:9206257. [PMID: 30643824 PMCID: PMC6311271 DOI: 10.1155/2018/9206257] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 06/22/2018] [Revised: 10/15/2018] [Accepted: 11/14/2018] [Indexed: 12/16/2022]
Abstract
Despite the fact that a significant fraction of kidney graft dysfunctions observed after transplantation is due to ischemia-reperfusion injuries, there is still no clear consensus regarding optimal kidney preservation strategy. This stems directly from the fact that as of yet, the mechanisms underlying ischemia-reperfusion injury are poorly defined, and the role of each preservation parameter is not clearly outlined. In the meantime, as donor demography changes, organ quality is decreasing which directly increases the rate of poor outcome. This situation has an impact on clinical guidelines and impedes their possible harmonization in the transplant community, which has to move towards changing organ preservation paradigms: new concepts must emerge and the definition of a new range of adapted preservation method is of paramount importance. This review presents existing barriers in transplantation (e.g., temperature adjustment and adequate protocol, interest for oxygen addition during preservation, and clear procedure for organ perfusion during machine preservation), discusses the development of novel strategies to overcome them, and exposes the importance of identifying reliable biomarkers to monitor graft quality and predict short and long-term outcomes. Finally, perspectives in therapeutic strategies will also be presented, such as those based on stem cells and their derivatives and innovative models on which they would need to be properly tested.
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13
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Ballinger MA, Andrews MT. Nature's fat-burning machine: brown adipose tissue in a hibernating mammal. ACTA ACUST UNITED AC 2018. [PMID: 29514878 DOI: 10.1242/jeb.162586] [Citation(s) in RCA: 38] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023]
Abstract
Brown adipose tissue (BAT) is a unique thermogenic tissue in mammals that rapidly produces heat via nonshivering thermogenesis. Small mammalian hibernators have evolved the greatest capacity for BAT because they use it to rewarm from hypothermic torpor numerous times throughout the hibernation season. Although hibernator BAT physiology has been investigated for decades, recent efforts have been directed toward understanding the molecular underpinnings of BAT regulation and function using a variety of methods, from mitochondrial functional assays to 'omics' approaches. As a result, the inner-workings of hibernator BAT are now being illuminated. In this Review, we discuss recent research progress that has identified players and pathways involved in brown adipocyte differentiation and maturation, as well as those involved in metabolic regulation. The unique phenotype of hibernation, and its reliance on BAT to generate heat to arouse mammals from torpor, has uncovered new molecular mechanisms and potential strategies for biomedical applications.
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Affiliation(s)
- Mallory A Ballinger
- Department of Integrative Biology and Museum of Vertebrate Zoology, University of California, Berkeley, CA 94720, USA
| | - Matthew T Andrews
- Department of Biochemistry and Biophysics, Oregon State University, Corvallis, OR 97331, USA
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14
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Hydrogen sulfide as a regulatory factor in kidney health and disease. Biochem Pharmacol 2018; 149:29-41. [DOI: 10.1016/j.bcp.2017.12.005] [Citation(s) in RCA: 27] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/13/2017] [Accepted: 12/05/2017] [Indexed: 12/19/2022]
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15
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Novel treatment strategies for chronic kidney disease: insights from the animal kingdom. Nat Rev Nephrol 2018; 14:265-284. [PMID: 29332935 DOI: 10.1038/nrneph.2017.169] [Citation(s) in RCA: 71] [Impact Index Per Article: 11.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Abstract
Many of the >2 million animal species that inhabit Earth have developed survival mechanisms that aid in the prevention of obesity, kidney disease, starvation, dehydration and vascular ageing; however, some animals remain susceptible to these complications. Domestic and captive wild felids, for example, show susceptibility to chronic kidney disease (CKD), potentially linked to the high protein intake of these animals. By contrast, naked mole rats are a model of longevity and are protected from extreme environmental conditions through mechanisms that provide resistance to oxidative stress. Biomimetic studies suggest that the transcription factor nuclear factor erythroid 2-related factor 2 (NRF2) offers protection in extreme environmental conditions and promotes longevity in the animal kingdom. Similarly, during months of fasting, immobilization and anuria, hibernating bears are protected from muscle wasting, azotaemia, thrombotic complications, organ damage and osteoporosis - features that are often associated with CKD. Improved understanding of the susceptibility and protective mechanisms of these animals and others could provide insights into novel strategies to prevent and treat several human diseases, such as CKD and ageing-associated complications. An integrated collaboration between nephrologists and experts from other fields, such as veterinarians, zoologists, biologists, anthropologists and ecologists, could introduce a novel approach for improving human health and help nephrologists to find novel treatment strategies for CKD.
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Dugbartey GJ. The smell of renal protection against chronic kidney disease: Hydrogen sulfide offers a potential stinky remedy. Pharmacol Rep 2017; 70:196-205. [PMID: 29471067 DOI: 10.1016/j.pharep.2017.10.007] [Citation(s) in RCA: 25] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/11/2017] [Revised: 09/28/2017] [Accepted: 10/17/2017] [Indexed: 12/20/2022]
Abstract
Chronic kidney disease (CKD) is a common global health challenge characterized by irreversible pathological processes that reduce kidney function and culminates in development of end-stage renal disease. It is associated with increased morbidity and mortality in addition to increased caregiver burden and higher financial cost. A central player in CKD pathogenesis and progression is renal hypoxia. Renal hypoxia stimulates induction of oxidative and endoplasmic reticulum stress, inflammation and tubulointerstitial fibrosis, which in turn, promote cellular susceptibility and further aggravate hypoxia, thus forming a pathological vicious cycle in CKD progression. Although the importance of CKD is widely appreciated, including improvements in the quality of existing therapies such as dialysis and transplantation, new therapeutic options are limited, as there is still increased morbidity, mortality and poor quality of life among CKD patients. Growing evidence indicates that hydrogen sulfide (H2S), a small gaseous signaling molecule with an obnoxious smell, accumulates in the renal medulla under hypoxic conditions, and functions as an oxygen sensor that restores oxygen balance and increases medullary flow. Moreover, plasma H2S level has been recently reported to be markedly reduced in CKD patients and animal models. Also, H2S has been established to possess potent antioxidant, anti-inflammatory, and anti-fibrotic properties in several experimental models of kidney diseases, suggesting that its supplementation could protect against CKD and retard its progression. The purpose of this review is to discuss current clinical and experimental developments regarding CKD, its pathophysiology, and potential cellular and molecular mechanisms of protection by H2S in experimental models of CKD.
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Affiliation(s)
- George J Dugbartey
- Division of Cardiology, The Heart Institute, Cincinnati Children's Hospital Medical Center, Cincinnati, OH, USA.
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