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Jun L, Tao YX, Geetha T, Babu JR. Mitochondrial Adaptation in Skeletal Muscle: Impact of Obesity, Caloric Restriction, and Dietary Compounds. Curr Nutr Rep 2024:10.1007/s13668-024-00555-7. [PMID: 38976215 DOI: 10.1007/s13668-024-00555-7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 06/16/2024] [Indexed: 07/09/2024]
Abstract
PURPOSE OF REVIEW: The global obesity epidemic has become a major public health concern, necessitating comprehensive research into its adverse effects on various tissues within the human body. Among these tissues, skeletal muscle has gained attention due to its susceptibility to obesity-related alterations. Mitochondria are primary source of energy production in the skeletal muscle. Healthy skeletal muscle maintains constant mitochondrial content through continuous cycle of synthesis and degradation. However, obesity has been shown to disrupt this intricate balance. This review summarizes recent findings on the impact of obesity on skeletal muscle mitochondria structure and function. In addition, we summarize the molecular mechanism of mitochondrial quality control systems and how obesity impacts these systems. RECENT FINDINGS: Recent findings show various interventions aimed at mitigating mitochondrial dysfunction in obese model, encompassing strategies including caloric restriction and various dietary compounds. Obesity has deleterious effect on skeletal muscle mitochondria by disrupting mitochondrial biogenesis and dynamics. Caloric restriction, omega-3 fatty acids, resveratrol, and other dietary compounds enhance mitochondrial function and present promising therapeutic opportunities.
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Affiliation(s)
- Lauren Jun
- Department of Nutritional Sciences, Auburn University, Auburn, AL, 36849, USA
| | - Ya-Xiong Tao
- Department of Anatomy Physiology and Pharmacology, Auburn University, Auburn, AL, 36849, USA
- Boshell Metabolic Diseases and Diabetes Program, Auburn University, Auburn, AL, 36849, USA
| | - Thangiah Geetha
- Department of Nutritional Sciences, Auburn University, Auburn, AL, 36849, USA
- Boshell Metabolic Diseases and Diabetes Program, Auburn University, Auburn, AL, 36849, USA
| | - Jeganathan Ramesh Babu
- Department of Nutritional Sciences, Auburn University, Auburn, AL, 36849, USA.
- Boshell Metabolic Diseases and Diabetes Program, Auburn University, Auburn, AL, 36849, USA.
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Vilas-Boas EA, Kowaltowski AJ. Mitochondrial redox state, bioenergetics, and calcium transport in caloric restriction: A metabolic nexus. Free Radic Biol Med 2024; 219:195-214. [PMID: 38677486 DOI: 10.1016/j.freeradbiomed.2024.04.234] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/04/2024] [Revised: 04/22/2024] [Accepted: 04/24/2024] [Indexed: 04/29/2024]
Abstract
Mitochondria congregate central reactions in energy metabolism, many of which involve electron transfer. As such, they are expected to both respond to changes in nutrient supply and demand and also provide signals that integrate energy metabolism intracellularly. In this review, we discuss how mitochondrial bioenergetics and reactive oxygen species production is impacted by dietary interventions that change nutrient availability and impact on aging, such as calorie restriction. We also discuss how dietary interventions alter mitochondrial Ca2+ transport, regulating both mitochondrial and cytosolic processes modulated by this ion. Overall, a plethora of literature data support the idea that mitochondrial oxidants and calcium transport act as integrating signals coordinating the response to changes in nutritional supply and demand in cells, tissues, and animals.
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Affiliation(s)
- Eloisa A Vilas-Boas
- Departamento de Análises Clínicas e Toxicológicas, Faculdade de Ciências Farmacêuticas, Universidade de São Paulo, Brazil.
| | - Alicia J Kowaltowski
- Departamento de Bioquímica, Instituto de Química, Universidade de São Paulo, Brazil.
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Storoschuk KL, Lesiuk D, Nuttall J, LeBouedec M, Khansari A, Islam H, Gurd BJ. Impact of fasting on the AMPK and PGC-1α axis in rodent and human skeletal muscle: A systematic review. Metabolism 2024; 152:155768. [PMID: 38154612 DOI: 10.1016/j.metabol.2023.155768] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/07/2023] [Revised: 12/18/2023] [Accepted: 12/22/2023] [Indexed: 12/30/2023]
Abstract
Based primarily on evidence from rodent models fasting is currently believed to improve metabolic health via activation of the AMPK-PGC-1α axis in skeletal muscle. However, it is unclear whether the skeletal muscle AMPK-PGC-1α axis is activated by fasting in humans. The current systematic review examined the fasting response in skeletal muscle from 34 selected studies (7 human, 21 mouse, and 6 rat). From these studies, we gathered 38 unique data points related to AMPK and 47 related to PGC-1α. In human studies, fasting mediated activation of the AMPK-PGC-1α axis is largely absent. Although evidence does support fasting-induced activation of the AMPK-PGC-1α axis in rodent skeletal muscle, the evidence is less robust than anticipated. Our findings question the ability of fasting to activate the AMPK-PGC-1α axis in human skeletal muscle and suggest that the metabolic benefits of fasting in humans are associated with caloric restriction rather than the induction of mitochondrial biogenesis. Registration: https://doi.org/10.17605/OSF.IO/KWNQY.
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Affiliation(s)
- K L Storoschuk
- School of Kinesiology and Health Studies, Queen's University, Kingston, Ontario, Canada
| | - D Lesiuk
- School of Kinesiology and Health Studies, Queen's University, Kingston, Ontario, Canada
| | - J Nuttall
- School of Kinesiology and Health Studies, Queen's University, Kingston, Ontario, Canada
| | - M LeBouedec
- School of Kinesiology and Health Studies, Queen's University, Kingston, Ontario, Canada
| | - A Khansari
- School of Kinesiology and Health Studies, Queen's University, Kingston, Ontario, Canada
| | - H Islam
- School of Health and Exercise Sciences, University of British Columbia Okanagan, Kelowna, BC, Canada
| | - B J Gurd
- School of Kinesiology and Health Studies, Queen's University, Kingston, Ontario, Canada.
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4
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Dunaevskaya SS, Sergeeva EY, Titova NM, Fefelova YA, Deulina VV. [Role of superoxide dismutase in acute pancreatitis: from antioxidant protection to gene regulation]. Khirurgiia (Mosk) 2024:112-117. [PMID: 38634592 DOI: 10.17116/hirurgia2024041112] [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] [Indexed: 04/19/2024]
Abstract
We present modern data on the role of superoxide dismutase (SOD) in antioxidant protection and gene regulation in acute pancreatitis. Antioxidant enzymes are essential in pathogenesis of numerous diseases. SOD is one of the key enzymes of antioxidant system. In this review, we analyzed activity of this enzyme depending on various factors, mechanisms and role in physiological and pathological processes, in particular, acute pancreatitis. SOD is significantly less active in patients with severe acute pancreatitis accompanied by renal failure, severe circulatory disorders and high mortality. There are some SOD gene polymorphisms, in particular, acute destructive pancreatitis R213G, contributing to acute inflammation. Thus, SOD is not only one of the key antioxidant enzymes, but also potential transcription factor regulating activity of signaling pathways. These aspects can underlie new therapies for diseases.
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Affiliation(s)
- S S Dunaevskaya
- Voino-Yasenetsky Krasnoyarsk State Medical University, Krasnoyarsk, Russia
| | - E Yu Sergeeva
- Voino-Yasenetsky Krasnoyarsk State Medical University, Krasnoyarsk, Russia
| | - N M Titova
- Voino-Yasenetsky Krasnoyarsk State Medical University, Krasnoyarsk, Russia
| | - Yu A Fefelova
- Voino-Yasenetsky Krasnoyarsk State Medical University, Krasnoyarsk, Russia
| | - V V Deulina
- Voino-Yasenetsky Krasnoyarsk State Medical University, Krasnoyarsk, Russia
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Borer K. Effects of duration of uninterrupted fast in weekly intermittent fasting: Comparison of an 82-week 5:2 case report to an isocaloric modified 4:3 protocol. RESEARCH SQUARE 2023:rs.3.rs-3701752. [PMID: 38106091 PMCID: PMC10723551 DOI: 10.21203/rs.3.rs-3701752/v1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/19/2023]
Abstract
Intermittent fasting (IF) approach for weight loss obviates the inconvenience of calorie counting of daily caloric restriction (DCR). It tests IF ability to better counteract a metabolic defense mechanism (MDM) than DCR. MDM obstructs weight loss and facilitates weight regain possibly by increasing hunger and efficiency of exercise energy expenditure (EEf), and by reducing resting metabolic rate (RMR) and physical activity (PA). A knowledge gap exists about whether the duration of weekly uninterrupted fasts (UFs), where the IF protocols are isocaloric, mitigate the MDM. This study compares two IF protocols that have the same weekly number of hours of fast (108) and free access to food (60), but which differ in the duration of UF. An 82-week case report was conducted with twice-weekly near-absolute 36-hour fasts on non-consecutive days (5:2-NC) and compared to ten studies with a 20-hour UF on three non-consecutive days (4:3-NC) modified through provision of a 500-600 kcal meal on fasting days. The large meal raised insulin concentration for 4 hours and reduced the UF to 8 hours followed by 12 nocturnal hours of fasting. The hypotheses were that (1) because of their matched F/E ratio, the rates of weight and fat losses will be similar in both protocols, and (2) because of its longer UF period, hunger will be higher and RMR and voluntary physical activity lower, in 5:8-NC than in M4:3-NC protocol,. The main differences between the two protocols were, (1) slower rates of weight and fat losses, (2) lower sensation of hunger and substantial decline in fullness, no change in RMR and physical activity, and 2.5 times higher post-fast concentration of the ketone body beta-hydroxybutyrate (BHB) in 8:2-NC compared to M4:3-NC protocol. Absence of increased hunger and the variability of the rate of weight loss in 5:2-NC protocol, plus increased EEf in one M4:3-NC study suggest that IF does not curtail MDM, but shortened UF period in M4:3-NC reduces elicitation of BHB. Thus, the addition of a large meal on fasting days is unnecessary for prevention of hunger and is counterproductive for increases in BHB and its potential health benefits.
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Oehm S, Steinke K, Schmidt J, Arjune S, Todorova P, Heinrich Lindemann C, Wöstmann F, Meyer F, Siedek F, Weimbs T, Müller RU, Grundmann F. RESET-PKD: a pilot trial on short-term ketogenic interventions in autosomal dominant polycystic kidney disease. Nephrol Dial Transplant 2023; 38:1623-1635. [PMID: 36423335 PMCID: PMC10435930 DOI: 10.1093/ndt/gfac311] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/25/2022] [Indexed: 11/27/2022] Open
Abstract
BACKGROUND Ketogenic dietary interventions (KDI) have been shown to be effective in animal models of polycystic kidney disease (PKD), but data from clinical trials are lacking. METHODS Ten autosomal dominant PKD (ADPKD) patients with rapid disease progression were enrolled at visit V1 and initially maintained a carbohydrate-rich diet. At V2, patients entered one of the two KDI arms: a 3-day water fast (WF) or a 14-day ketogenic diet (KD). At V3, they resumed their normal diet for 3-6 weeks until V4. At each visit, magnetic resonance imaging kidney and liver volumetry was performed. Ketone bodies were evaluated to assess metabolic efficacy and questionnaires were used to determine feasibility. RESULTS All participants [KD n = 5, WF n = 5; age 39.8 ± 11.6 years; estimated glomerular filtration rate 82 ± 23.5 mL/min/1.73 m2; total kidney volume (TKV) 2224 ± 1156 mL] were classified as Mayo Class 1C-1E. Acetone levels in breath and beta-hydroxybutyrate (BHB) blood levels increased in both study arms (V1 to V2 average acetone: 2.7 ± 1.2 p.p.m., V2 to V3: 22.8 ± 11.9 p.p.m., P = .0006; V1 to V2 average BHB: 0.22 ± 0.08 mmol/L, V2 to V3: 1.88 ± 0.93 mmol/L, P = .0008). Nine of 10 patients reached a ketogenic state and 9/10 evaluated KDIs as feasible. TKV did not change during this trial. However, we found a significant impact on total liver volume (ΔTLV V2 to V3: -7.7%, P = .01), mediated by changes in its non-cystic fraction. CONCLUSIONS RESET-PKD demonstrates that short-term KDIs potently induce ketogenesis and are feasible for ADPKD patients in daily life. While TLV quickly changed upon the onset of ketogenesis, changes in TKV may require longer-term interventions.
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Affiliation(s)
- Simon Oehm
- University of Cologne, Faculty of Medicine and University Hospital, Department 2 of Internal Medicine and Center for Molecular Medicine, Cologne, Germany
| | - Konstantin Steinke
- University of Cologne, Faculty of Medicine and University Hospital, Department 2 of Internal Medicine and Center for Molecular Medicine, Cologne, Germany
| | - Johannes Schmidt
- University of Cologne, Faculty of Medicine and University Hospital, Department 2 of Internal Medicine and Center for Molecular Medicine, Cologne, Germany
| | - Sita Arjune
- University of Cologne, Faculty of Medicine and University Hospital, Department 2 of Internal Medicine and Center for Molecular Medicine, Cologne, Germany
| | - Polina Todorova
- University of Cologne, Faculty of Medicine and University Hospital, Department 2 of Internal Medicine and Center for Molecular Medicine, Cologne, Germany
| | - Christoph Heinrich Lindemann
- University of Cologne, Faculty of Medicine and University Hospital, Department 2 of Internal Medicine and Center for Molecular Medicine, Cologne, Germany
| | - Fabian Wöstmann
- University of Cologne, Faculty of Medicine and University Hospital, Department 2 of Internal Medicine and Center for Molecular Medicine, Cologne, Germany
| | - Franziska Meyer
- University of Cologne, Faculty of Medicine and University Hospital, Institute of Diagnostic and Interventional Radiology, Cologne, Germany
| | - Florian Siedek
- University of Cologne, Faculty of Medicine and University Hospital, Institute of Diagnostic and Interventional Radiology, Cologne, Germany
| | - Thomas Weimbs
- Department of Molecular, Cellular and Developmental Biology and Neuroscience Research Institute, University of California Santa Barbara, Santa Barbara, CA, USA
| | - Roman-Ulrich Müller
- University of Cologne, Faculty of Medicine and University Hospital, Department 2 of Internal Medicine and Center for Molecular Medicine, Cologne, Germany
- Cologne Excellence Cluster on Cellular Stress Responses in Aging-Associated Diseases (CECAD), University of Cologne, Faculty of Medicine and University Hospital Cologne, Cologne, Germany
| | - Franziska Grundmann
- University of Cologne, Faculty of Medicine and University Hospital, Department 2 of Internal Medicine and Center for Molecular Medicine, Cologne, Germany
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Tang D, Tang Q, Huang W, Zhang Y, Tian Y, Fu X. Fasting: From Physiology to Pathology. ADVANCED SCIENCE (WEINHEIM, BADEN-WURTTEMBERG, GERMANY) 2023; 10:e2204487. [PMID: 36737846 PMCID: PMC10037992 DOI: 10.1002/advs.202204487] [Citation(s) in RCA: 9] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 08/05/2022] [Revised: 01/06/2023] [Indexed: 06/18/2023]
Abstract
Overnutrition is a risk factor for various human diseases, including neurodegenerative diseases, metabolic disorders, and cancers. Therefore, targeting overnutrition represents a simple but attractive strategy for the treatment of these increasing public health threats. Fasting as a dietary intervention for combating overnutrition has been extensively studied. Fasting has been practiced for millennia, but only recently have its roles in the molecular clock, gut microbiome, and tissue homeostasis and function emerged. Fasting can slow aging in most species and protect against various human diseases, including neurodegenerative diseases, metabolic disorders, and cancers. These centuried and unfading adventures and explorations suggest that fasting has the potential to delay aging and help prevent and treat diseases while minimizing side effects caused by chronic dietary interventions. In this review, recent animal and human studies concerning the role and underlying mechanism of fasting in physiology and pathology are summarized, the therapeutic potential of fasting is highlighted, and the combination of pharmacological intervention and fasting is discussed as a new treatment regimen for human diseases.
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Affiliation(s)
- Dongmei Tang
- Division of Endocrinology and Metabolism, National Clinical Research Center for Geriatrics, State Key Laboratory of Biotherapy, West China HospitalSichuan University and Collaborative Innovation Center of BiotherapyChengduSichuan610041China
| | - Qiuyan Tang
- Neurology Department of Integrated Traditional Chinese and Western Medicine, School of Clinical MedicineChengdu University of Traditional Chinese MedicineChengduSichuan610075China
| | - Wei Huang
- West China Centre of Excellence for PancreatitisInstitute of Integrated Traditional Chinese and Western MedicineWest China‐Liverpool Biomedical Research CentreWest China HospitalSichuan UniversityChengduSichuan610041China
| | - Yuwei Zhang
- Division of Endocrinology and MetabolismWest China HospitalSichuan UniversityChengduSichuan610041China
| | - Yan Tian
- Division of Endocrinology and Metabolism, National Clinical Research Center for Geriatrics, State Key Laboratory of Biotherapy and Cancer Center, West China HospitalSichuan University and Collaborative Innovation Center of BiotherapyChengduSichuan610041China
| | - Xianghui Fu
- Division of Endocrinology and Metabolism, National Clinical Research Center for Geriatrics, State Key Laboratory of Biotherapy and Cancer Center, West China HospitalSichuan University and Collaborative Innovation Center of BiotherapyChengduSichuan610041China
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The utility of beta-hydroxybutyrate in detecting myocardial glucose uptake suppression in patients undergoing inflammatory [18F]-FDG PET studies. Eur J Nucl Med Mol Imaging 2023; 50:1103-1110. [PMID: 36474124 DOI: 10.1007/s00259-022-06062-7] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/10/2022] [Accepted: 11/25/2022] [Indexed: 12/13/2022]
Abstract
PURPOSE We evaluated whether serum beta-hydroxybutyrate (BHB) can identify adequate suppression of the left ventricle (LV) among patients undergoing [18F]-fluorodeoxyglucose positron emission tomography ([18F]-FDG PET) for cardiac inflammatory/infectious studies. METHODS Consecutive patients who underwent [18F]-FDG PET imaging were included. Serum BHB levels were measured in all patients on the day of imaging prior to injecting [18F]-FDG. Myocardial [18F]-FDG suppression was defined if [18F]-FDG uptake in the walls of myocardium, measured using standardized uptake values (SUV), was lower than the blood pool. The optimal threshold of BHB to identify myocardial suppression was based on receiver operating characteristics (ROC) in a random 30% sample of the study population (derivation cohort) and tested in the remaining 70% of sample (validation cohort). RESULTS A total of 256 images from 220 patients were included. Patients with sufficient LV suppression had significantly higher BHB levels compared to those with non-suppressed myocardium (median (IQR) BHB 0.6 (0.3-0.8) vs. 0.2 (0.2-0.3) mmol/l, p < 0.001, respectively). BHB level ≥ 0.335 mmol/l had a sensitivity of 84.90% and a specificity of 92.60% to identify adequate LV suppression in the validation cohort. All patients (100%) with BHB ≥ 0.41 mmol/l had adequate myocardial suppression compared to 29.63% of patients with BHB ≤ 0.20 mmol/l. CONCLUSION Serum BHB level can be used at the point of care to identify sufficient LV suppression in patients undergoing [18F]-FDG PET cardiac inflammatory/infectious studies. Central illustration (image to the right) shows representative cases of patient images and BHB and, in the image to the left, shows the sensitivity and specificity to identify left myocardial suppression using BHB in validation group.
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Li W, Trieu J, Blazev R, Parker BL, Murphy KT, Swiderski K, Lynch GS. Sulforaphane attenuates cancer cell-induced atrophy of C2C12 myotubes. Am J Physiol Cell Physiol 2023; 324:C205-C221. [PMID: 36534500 DOI: 10.1152/ajpcell.00025.2022] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
Abstract
Cancer cachexia is common in many cancers and the loss of skeletal muscle mass compromises the response to therapies and quality of life. A contributing mechanism is oxidative stress and compounds able to attenuate it may be protective. Sulforaphane (SFN), a natural antioxidant in cruciferous vegetables, activates nuclear factor erythroid 2-related factor 2 (Nrf2) signaling to decrease oxidative stress. Although SFN has potential as a cancer therapeutic, whether it can attenuate muscle wasting in the absence or presence of chemotherapy is unknown. In healthy C2C12 myotubes, SFN administration for 48 h induced hypertrophy through increased myoblast fusion via Nrf2 and ERK signaling. To determine whether SFN could attenuate wasting induced by cancer cells, myotubes were cocultured with or without Colon-26 (C-26) cancer cells for 48 h and treated with 5-fluorouracil (5-FU, 5 µM) or vehicle (DMSO). SFN (10 µM) or DMSO was added for the final 24 h. Coculture with cancer cells in the absence and presence of 5-FU reduced myotube width by ∼30% (P < 0.001) and ∼20% (P < 0.01), respectively, which was attenuated by SFN (P < 0.05). Exposure to C-26 conditioned media reduced myotube width by 15% (P < 0.001), which was attenuated by SFN. Western immunoblotting and qRT-PCR confirmed activation of Nrf2 signaling and antioxidant genes. Coadministration of Nrf2 inhibitors (ML-385) or MEK inhibitors (PD184352) revealed that SFN's attenuation of atrophy was blocked by ERK inhibition. These data support the chemoprotective and antioxidative function of SFN in myotubes, highlighting its therapeutic potential for cancer-related muscle wasting.
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Affiliation(s)
- Wenlan Li
- Centre for Muscle Research, Department of Anatomy and Physiology, The University of Melbourne, Melbourne, Victoria, Australia
| | - Jennifer Trieu
- Centre for Muscle Research, Department of Anatomy and Physiology, The University of Melbourne, Melbourne, Victoria, Australia
| | - Ronnie Blazev
- Centre for Muscle Research, Department of Anatomy and Physiology, The University of Melbourne, Melbourne, Victoria, Australia
| | - Benjamin L Parker
- Centre for Muscle Research, Department of Anatomy and Physiology, The University of Melbourne, Melbourne, Victoria, Australia
| | - Kate T Murphy
- Centre for Muscle Research, Department of Anatomy and Physiology, The University of Melbourne, Melbourne, Victoria, Australia
| | - Kristy Swiderski
- Centre for Muscle Research, Department of Anatomy and Physiology, The University of Melbourne, Melbourne, Victoria, Australia
| | - Gordon S Lynch
- Centre for Muscle Research, Department of Anatomy and Physiology, The University of Melbourne, Melbourne, Victoria, Australia
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Pérez-Rodríguez M, Huertas JR, Villalba JM, Casuso RA. Mitochondrial adaptations to calorie restriction and bariatric surgery in human skeletal muscle: a systematic review with meta-analysis. Metabolism 2023; 138:155336. [PMID: 36302454 DOI: 10.1016/j.metabol.2022.155336] [Citation(s) in RCA: 6] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/28/2022] [Revised: 10/11/2022] [Accepted: 10/17/2022] [Indexed: 11/18/2022]
Abstract
OBJECTIVE We performed a meta-analysis to determine the changes induced by calorie restriction (CR) and bariatric surgery on human skeletal muscle mitochondria. METHODS A systematic search of Medline and Web of Science was conducted. Controlled trials exploring CR (≥14 days) and mitochondrial function and/or content assessment were included. Moreover, studies analyzing weight loss following gastric surgery were included for comparison purposes. Human muscle data from 28 studies assessing CR (520 muscle samples) and from 10 studies assessing bariatric surgery (155 muscle samples) were analyzed in a random effect meta-analysis with three a priori chosen covariates. MAIN RESULTS We report a decrease (p < 0.05) (mean (95 % CI)) in maximal mitochondrial state 3 respiration in response to CR (-0.44 (-0.85, -0.03)) but not in response to surgery (-0.33 (-1.18, 0.52)). No changes in mitochondrial content were reported after CR (-0.05 (-0.12, 0.13)) or in response to surgery (0.23 (-0.05, 0.52)). Moreover, data from CR subjects showed a reduction in complex IV (CIV) activity (-0.29 (-0.56, -0.03)) but not in CIV content (-0.21 (-0.63, 0.22)). Similar results were obtained when the length of the protocol, the initial body mass index, and the estimated energy deficit were included in the model as covariates. CONCLUSION The observation of reduced maximal mitochondrial state 3, uncoupled respiration, and CIV activity without altering mitochondrial content suggests that, in human skeletal muscle, CR mainly modulates intrinsic mitochondrial function.
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Affiliation(s)
- Miguel Pérez-Rodríguez
- Department of Cell Biology, Physiology and Immunology, University of Córdoba, and ceiA3Campus of International Excellence in Agrifood, Spain
| | | | - José M Villalba
- Department of Cell Biology, Physiology and Immunology, University of Córdoba, and ceiA3Campus of International Excellence in Agrifood, Spain
| | - Rafael A Casuso
- Department of Physiology, University of Granada, Spain; Department of Health Sciences, Universidad Loyola Andalucía, Spain.
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He Z, Xu H, Li C, Yang H, Mao Y. Intermittent fasting and immunomodulatory effects: A systematic review. Front Nutr 2023; 10:1048230. [PMID: 36925956 PMCID: PMC10011094 DOI: 10.3389/fnut.2023.1048230] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/19/2022] [Accepted: 02/09/2023] [Indexed: 03/04/2023] Open
Abstract
Introduction strategy of periodic food restriction and fixed eating windows, could beneficially modify individuals by losing body weight, regulating glucose or lipid metabolism, reducing blood pressure, and modulating the immune system. Specific effects of IF and its mechanisms have not yet been assessed collectively. Thus, this systematic review aims to summarize and compare clinical trials that explored the immunomodulatory effects of IF. Methods After screening, 28 studies were included in this systematic review. Results In addition to weight loss, IF could benefit health subjects by strengthening their circadian rhythms, migrating immune cells, lower inflammatory factors, and enriching microbials. In addition of the anti-inflammatory effect by regulating macrophages, protection against oxidative stress with hormone secretion and oxidative-related gene expression plays a key beneficial role for the influence of IF on obese subjects. Discussion Physiological stress by surgery and pathophysiological disorders by endocrine diseases may be partly eased with IF. Moreover, IF might be used to treat anxiety and cognitive disorders with its cellular, metabolic and circadian mechanisms. Finally, the specific effects of IF and the mechanisms pertaining to immune system in these conditions require additional studies.
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Affiliation(s)
- Zhangyuting He
- Peking Union Medical College, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing, China
| | - Haifeng Xu
- Department of Liver Surgery, Peking Union Medical College (PUMC) Hospital, PUMC and Chinese Academy of Medical Sciences (CAMS), Beijing, China
| | - Changcan Li
- Department of Liver Surgery, Peking Union Medical College (PUMC) Hospital, PUMC and Chinese Academy of Medical Sciences (CAMS), Beijing, China
| | - Huayu Yang
- Department of Liver Surgery, Peking Union Medical College (PUMC) Hospital, PUMC and Chinese Academy of Medical Sciences (CAMS), Beijing, China
| | - Yilei Mao
- Department of Liver Surgery, Peking Union Medical College (PUMC) Hospital, PUMC and Chinese Academy of Medical Sciences (CAMS), Beijing, China
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12
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Ingersen A, Helset HR, Calov M, Chabanova E, Harreskov EG, Jensen C, Hansen CN, Prats C, Helge JW, Larsen S, Dela F. Metabolic effects of alternate-day fasting in males with obesity with or without type 2 diabetes. Front Physiol 2022; 13:1061063. [PMID: 36531168 PMCID: PMC9748572 DOI: 10.3389/fphys.2022.1061063] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/04/2022] [Accepted: 11/21/2022] [Indexed: 10/14/2023] Open
Abstract
Alternate-day fasting induces oscillations in energy stores. We hypothesized that repeated oscillations increases insulin secretion and sensitivity, and improve metabolic health in patients with obesity with or without type 2 diabetes (T2DM). Twenty-three male patients fasted every other day for 30 h for 6 weeks. Experiments included resting energy expenditure, continuous glucose monitoring, intravenous glucose tolerance test, euglycemic hyperinsulinemic clamp, body composition, hepatic triglyceride content, muscle biopsies which were performed at baseline, during 3 weeks without allowed weight loss, and after additional 3 weeks with weight loss. Bodyweight decreased ∼1% and further ∼3% during weeks one to three and four to six, respectively (p < 0.05). Only minor changes in fat mass occurred in weeks 1-3. With weight loss, visceral fat content decreased by 13 ± 3% and 12 ± 2% from baseline in patients with and without T2DM, respectively (p < 0.05). Hepatic triglyceride content decreased by 17 ± 9% and 36 ± 9% (with diabetes) and 27 ± 8% and 40 ± 8% (without diabetes) from baseline to week 3 and week 6, respectively (all p < 0.05). Muscle lipid and glycogen content oscillated with the intervention. Glucose homeostasis, insulin secretion and sensitivity was impaired in patients with T2DM and did not change without weight loss, but improved (p < 0.05) when alternate day fasting was combined with weight loss. In conclusion, alternate-day fasting is feasible in patients with obesity and T2DM, and decreases visceral fat and liver fat deposits. Energy store oscillations by alternate-day fasting do not improve insulin secretion or sensitivity per se. Clinical Trial registration: (ClinicalTrials.gov), (ID NCT02420054).
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Affiliation(s)
- Arthur Ingersen
- Xlab, Center for Healthy Aging, Department of Biomedical Sciences, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
- Department of Geriatrics, Bispebjerg-Frederiksberg University Hospital, Copenhagen, Denmark
| | - Hildegunn Rømma Helset
- Xlab, Center for Healthy Aging, Department of Biomedical Sciences, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
| | - Monika Calov
- Xlab, Center for Healthy Aging, Department of Biomedical Sciences, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
| | - Elizaveta Chabanova
- Department of Diagnostic Radiology, Copenhagen University Hospital, Copenhagen, Denmark
| | - Eva Gjerlevsen Harreskov
- Xlab, Center for Healthy Aging, Department of Biomedical Sciences, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
| | - Christina Jensen
- Xlab, Center for Healthy Aging, Department of Biomedical Sciences, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
| | - Christina Neigaard Hansen
- Xlab, Center for Healthy Aging, Department of Biomedical Sciences, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
| | - Clara Prats
- Xlab, Center for Healthy Aging, Department of Biomedical Sciences, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
| | - Jørn Wulff Helge
- Xlab, Center for Healthy Aging, Department of Biomedical Sciences, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
| | - Steen Larsen
- Xlab, Center for Healthy Aging, Department of Biomedical Sciences, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
- Clinical Research Centre, Medical University of Bialystok, Bialystok, Poland
| | - Flemming Dela
- Xlab, Center for Healthy Aging, Department of Biomedical Sciences, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
- Department of Geriatrics, Bispebjerg-Frederiksberg University Hospital, Copenhagen, Denmark
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13
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Yin L, Li N, Jia W, Wang N, Liang M, Shang J, Qiang G, Du G, Yang X. Urotensin receptor acts as a novel target for ameliorating fasting-induced skeletal muscle atrophy. Pharmacol Res 2022; 185:106468. [PMID: 36167277 DOI: 10.1016/j.phrs.2022.106468] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/09/2022] [Revised: 09/17/2022] [Accepted: 09/23/2022] [Indexed: 11/18/2022]
Abstract
Urotensin receptor (UT) is a G-protein-coupled receptor, whose endogenous ligand is urotensin-II (U-II). Skeletal muscle mass is regulated by various conditions, such as nutritional status, exercise, and diseases. Previous studies have pointed out that the urotensinergic system is involved in skeletal muscle metabolism and function, but its mechanism remains unclear, especially given the lack of research on the effect and mechanism of fasting. In this study, UT receptor knockout mice were generated to evaluate whether UT has effects on fasting induced skeletal muscle atrophy. Furthermore, the UT antagonist palosuran (3, 10, 30mg/kg) was intraperitoneally administered daily for 5 days to clarify the therapeutic effect of UT antagonism. Our results found the mice that fasted for 48hours exhibited skeletal muscle atrophy, accompanied by enhanced U-II levels in both skeletal muscles and blood. UT receptor knockout effectively prevented fasting-induced skeletal muscle atrophy. The UT antagonist ameliorated fasting-induced muscle atrophy in mice as determined by increased muscle strengths, weights, and muscle fiber areas (including fast, slow, and mixed types). In addition, the UT antagonist reduced skeletal muscle atrophic markers, including F-box only protein 32 (FBXO32) and tripartite motif containing 63 (TRIM63). Moreover, the UT antagonist was also observed to enhance PI3K/AKT/mTOR while inhibiting autophagy signaling. In summary, our study provides the first evidence that UT antagonism may represent a novel therapeutic approach for the treatment of fasting-induced skeletal muscle atrophy.
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Affiliation(s)
- Lin Yin
- Shanxi Bethune Hospital, Shanxi Academy of Medical Sciences,Tongji Shanxi Hospital, Third Hospital of Shanxi Medical University, Taiyuan 030032, China; Beijing Key Laboratory of Drug Target Identification and New Drug Screening, Institute of Materia Medica, Chinese Academy of Medical Sciences & Peking Union Medical College, Beijing 100050, China
| | - Na Li
- Beijing Key Laboratory of Drug Target Identification and New Drug Screening, Institute of Materia Medica, Chinese Academy of Medical Sciences & Peking Union Medical College, Beijing 100050, China
| | - Weihua Jia
- Beijing Key Laboratory of Drug Target Identification and New Drug Screening, Institute of Materia Medica, Chinese Academy of Medical Sciences & Peking Union Medical College, Beijing 100050, China
| | - Nuoqi Wang
- Beijing Key Laboratory of Drug Target Identification and New Drug Screening, Institute of Materia Medica, Chinese Academy of Medical Sciences & Peking Union Medical College, Beijing 100050, China
| | - Meidai Liang
- Beijing Key Laboratory of Drug Target Identification and New Drug Screening, Institute of Materia Medica, Chinese Academy of Medical Sciences & Peking Union Medical College, Beijing 100050, China
| | - Jiamin Shang
- Beijing Key Laboratory of Drug Target Identification and New Drug Screening, Institute of Materia Medica, Chinese Academy of Medical Sciences & Peking Union Medical College, Beijing 100050, China
| | - Guifen Qiang
- Beijing Key Laboratory of Drug Target Identification and New Drug Screening, Institute of Materia Medica, Chinese Academy of Medical Sciences & Peking Union Medical College, Beijing 100050, China; State Key Laboratory of Bioactive Substance and Function of Natural Medicines, Institute of Materia Medica, Chinese Academy of Medical Sciences and Peking Union Medical College and Beijing Key Laboratory of Drug Target and Screening Research, Beijing 100050, China
| | - Guanhua Du
- Beijing Key Laboratory of Drug Target Identification and New Drug Screening, Institute of Materia Medica, Chinese Academy of Medical Sciences & Peking Union Medical College, Beijing 100050, China; State Key Laboratory of Bioactive Substance and Function of Natural Medicines, Institute of Materia Medica, Chinese Academy of Medical Sciences and Peking Union Medical College and Beijing Key Laboratory of Drug Target and Screening Research, Beijing 100050, China.
| | - Xiuying Yang
- Beijing Key Laboratory of Drug Target Identification and New Drug Screening, Institute of Materia Medica, Chinese Academy of Medical Sciences & Peking Union Medical College, Beijing 100050, China.
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14
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Xiao Y, Liu Y, Zhao L, Zhou Y. Effect of 5:2 Fasting Diet on Liver Fat Content in Patients with Type 2 Diabetic with Nonalcoholic Fatty Liver Disease. Metab Syndr Relat Disord 2022; 20:459-465. [PMID: 35925752 DOI: 10.1089/met.2022.0014] [Citation(s) in RCA: 9] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022] Open
Abstract
Background: The prevalence of nonalcoholic fatty liver disease (NAFLD) is rapidly growing in China, especially in patients with type 2 diabetes mellitus (T2DM). Weight loss strategies have been shown to treat NAFLD effectively. We conducted a 24-week, prospective, randomized study in T2DM patients with NAFLD to evaluate the effects of a 5:2 fasting diet on liver fat content. Methods: Sixty-one T2DM patients with NAFLD were enrolled and randomly divided into a 5:2 fasting diet intervention group (5:2 diet group, n = 31) and 1.8 mg/day liraglutide intervention group (Lira group, n = 30). The study was performed for 24 weeks. Data of the body weight, waist circumference, plasma lipids and glucose profile, fasting plasma insulin, and liver function parameters were collected. Controlled attenuation parameter (CAP) was measured to assess the liver fat content. Superoxide dismutase (SOD) and malondialdehyde (MDA) were measured to evaluate oxidative stress status. Results: At 24 weeks after intervention, compared with those at baseline, CAP was significantly decreased in both the 5:2 diet group and Lira group, which was 7.4% and 5.5%, respectively. Body weight, plasma lipids and glucose profile, and liver function parameters improved significantly, while homeostasis model assessment-β (HOMA-β) was significantly increased in both groups (all P < 0.05). Stepwise linear regression showed that increased HOMA-β and SOD, as well as reduced body mass index (BMI), were the independent predictors of CAP decrease in the Lira group (P = 0.000, 0.000, 0.015). In contrast, reduced BMI and MDA were the independent influencing factors of CAP decrease in the 5:2 diet group (P = 0.011, 0.043). The common side effects in the 5:2 diet group were hunger (60%), weakness (10%), and constipation (0.3%). Conclusions: A 5:2 fasting diet achieved comparable effects with liraglutide on liver fat content in patients with T2DM with NAFLD by reducing BMI and oxidative stress. Both treatment strategies were safe and effective for glucose control.
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Affiliation(s)
- Yanxin Xiao
- Department of Endocrinology, The Third Hospital of Hebei Medical University, Shijiazhuang, China.,Department of Endocrinology, Baoding No.1 Central Hospital, Baoding, China
| | - Yan Liu
- Department of Endocrinology, The Third Hospital of Hebei Medical University, Shijiazhuang, China
| | - Liwei Zhao
- Department of Radiology, People's Hospital of Baoding City, Baoding, China
| | - Yaru Zhou
- Department of Endocrinology, The Third Hospital of Hebei Medical University, Shijiazhuang, China
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15
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Mthembu SXH, Mazibuko-Mbeje SE, Ziqubu K, Nyawo TA, Obonye N, Nyambuya TM, Nkambule BB, Silvestri S, Tiano L, Muller CJF, Dludla PV. Impact of physical exercise and caloric restriction in patients with type 2 diabetes: Skeletal muscle insulin resistance and mitochondrial dysfunction as ideal therapeutic targets. Life Sci 2022; 297:120467. [PMID: 35271881 DOI: 10.1016/j.lfs.2022.120467] [Citation(s) in RCA: 18] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/15/2022] [Revised: 03/04/2022] [Accepted: 03/04/2022] [Indexed: 01/01/2023]
Abstract
Skeletal muscle insulin resistance and mitochondrial dysfunction are some of the major pathological defects implicated in the development of type 2 diabetes (T2D). Therefore, it has become necessary to understand how common interventions such as physical exercise and caloric restriction affect metabolic function, including physiological processes that implicate skeletal muscle dysfunction within a state of T2D. This review critically discusses evidence on the impact of physical exercise and caloric restriction on markers of insulin resistance and mitochondrial dysfunction within the skeletal muscle of patients with T2D or related metabolic complications. Importantly, relevant information from clinical studies was acquired through a systematic approach targeting major electronic databases and search engines such as PubMed, Google Scholar, and Cochrane library. The reported evidence suggests that interventions like physical exercise and caloric restriction, within a duration of approximately 2 to 4 months, can improve insulin sensitivity, in part by targeting the phosphoinositide 3-kinases/protein kinase B pathway in patients with T2D. Furthermore, both physical exercise and caloric restriction can effectively modulate markers related to improved mitochondrial function and dynamics. This was consistent with an improved modulation of mitochondrial oxidative capacity and reduced production of reactive oxygen species in patients with T2D or related metabolic complications. However, such conclusions are based on limited evidence, additional clinical trials are required to better understand these interventions on pathological mechanisms of T2D and related abnormalities.
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Affiliation(s)
- Sinenhlanhla X H Mthembu
- Biomedical Research and Innovation Platform, South African Medical Research Council, Tygerberg 7505, South Africa; Department of Biochemistry, North-West University, Mafikeng Campus, Mmabatho 2735, South Africa
| | | | - Khanyisani Ziqubu
- Department of Biochemistry, North-West University, Mafikeng Campus, Mmabatho 2735, South Africa
| | - Thembeka A Nyawo
- Biomedical Research and Innovation Platform, South African Medical Research Council, Tygerberg 7505, South Africa; Centre for Cardiometabolic Research Africa (CARMA), Division of Medical Physiology, Faculty of Medicine and Health Sciences, Stellenbosch University, Tygerberg 7505, South Africa
| | - Nnini Obonye
- Biomedical Research and Innovation Platform, South African Medical Research Council, Tygerberg 7505, South Africa; Centre for Cardiometabolic Research Africa (CARMA), Division of Medical Physiology, Faculty of Medicine and Health Sciences, Stellenbosch University, Tygerberg 7505, South Africa
| | - Tawanda M Nyambuya
- Department of Health Sciences, Faculty of Health and Applied Sciences, Namibia University of Science and Technology, Windhoek 9000, Namibia
| | - Bongani B Nkambule
- School of Laboratory Medicine and Medical Sciences, College of Health Sciences, University of KwaZulu Natal, Durban 4000, South Africa
| | - Sonia Silvestri
- Department of Life and Environmental Sciences, Polytechnic University of Marche, Ancona 60131, Italy
| | - Luca Tiano
- Department of Life and Environmental Sciences, Polytechnic University of Marche, Ancona 60131, Italy
| | - Christo J F Muller
- Biomedical Research and Innovation Platform, South African Medical Research Council, Tygerberg 7505, South Africa; Centre for Cardiometabolic Research Africa (CARMA), Division of Medical Physiology, Faculty of Medicine and Health Sciences, Stellenbosch University, Tygerberg 7505, South Africa; Department of Biochemistry and Microbiology, University of Zululand, KwaDlangezwa 3880, South Africa
| | - Phiwayinkosi V Dludla
- Biomedical Research and Innovation Platform, South African Medical Research Council, Tygerberg 7505, South Africa.
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16
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Joaquim L, Faria A, Loureiro H, Matafome P. Benefits, mechanisms, and risks of intermittent fasting in metabolic syndrome and type 2 diabetes. J Physiol Biochem 2022; 78:295-305. [PMID: 34985730 DOI: 10.1007/s13105-021-00839-4] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/15/2021] [Accepted: 08/18/2021] [Indexed: 10/19/2022]
Abstract
One of the emergent nutritional strategies for improving multiple features of cardiometabolic diseases is the practice of intermittent fasting (IF), which consists of alternating periods of eating and fasting. IF can reduce circulating glucose and insulin levels, fat mass, and the risk of developing age-related pathologies. IF appears to upregulate evolution-conserved adaptive cellular responses, such as stress-response pathways, autophagy, and mitochondrial function. IF was also observed to modulate the circadian rhythms of hormones like insulin or leptin, among others, which levels change in conditions of food abundance and deficit. However, some contradictory results regarding the duration of the interventions and the anterior metabolic status of the participants suggest that more and longer studies are needed in order to draw conclusions. This review summarizes the current knowledge regarding the role of IF in the modulation of mechanisms involved in type 2 diabetes, as well as the risks.
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Affiliation(s)
- Lisandra Joaquim
- Instituto Politécnico de Coimbra, Coimbra Health School (ESTeSC), Coimbra, Portugal
| | - Ana Faria
- Instituto Politécnico de Coimbra, Coimbra Health School (ESTeSC), Coimbra, Portugal
| | - Helena Loureiro
- Instituto Politécnico de Coimbra, Coimbra Health School (ESTeSC), Coimbra, Portugal
| | - Paulo Matafome
- Instituto Politécnico de Coimbra, Coimbra Health School (ESTeSC), Coimbra, Portugal.
- Institute of Clinical and Biomedical Research (iCBR), Faculty of Medicine, University of Coimbra, Subunit 1, 1st floor, Azinhaga de Santa Comba, Celas, 3000-354, Coimbra, Portugal.
- Centre for Innovative Biomedicine and Biotechnology (CIBB), University of Coimbra, Coimbra, Portugal.
- Clinical Academic Center, Coimbra, Portugal.
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17
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Healy KL, Morris AR, Liu AC. Circadian Synchrony: Sleep, Nutrition, and Physical Activity. FRONTIERS IN NETWORK PHYSIOLOGY 2021; 1:732243. [PMID: 35156088 PMCID: PMC8830366 DOI: 10.3389/fnetp.2021.732243] [Citation(s) in RCA: 17] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/28/2021] [Accepted: 09/20/2021] [Indexed: 08/01/2023]
Abstract
The circadian clock in mammals regulates the sleep/wake cycle and many associated behavioral and physiological processes. The cellular clock mechanism involves a transcriptional negative feedback loop that gives rise to circadian rhythms in gene expression with an approximately 24-h periodicity. To maintain system robustness, clocks throughout the body must be synchronized and their functions coordinated. In mammals, the master clock is located in the suprachiasmatic nucleus (SCN) of the hypothalamus. The SCN is entrained to the light/dark cycle through photic signal transduction and subsequent induction of core clock gene expression. The SCN in turn relays the time-of-day information to clocks in peripheral tissues. While the SCN is highly responsive to photic cues, peripheral clocks are more sensitive to non-photic resetting cues such as nutrients, body temperature, and neuroendocrine hormones. For example, feeding/fasting and physical activity can entrain peripheral clocks through signaling pathways and subsequent regulation of core clock genes and proteins. As such, timing of food intake and physical activity matters. In an ideal world, the sleep/wake and feeding/fasting cycles are synchronized to the light/dark cycle. However, asynchronous environmental cues, such as those experienced by shift workers and frequent travelers, often lead to misalignment between the master and peripheral clocks. Emerging evidence suggests that the resulting circadian disruption is associated with various diseases and chronic conditions that cause further circadian desynchrony and accelerate disease progression. In this review, we discuss how sleep, nutrition, and physical activity synchronize circadian clocks and how chronomedicine may offer novel strategies for disease intervention.
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