Browsing by Subject "fasting"

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  • Mihaylova, Maria M.; Cheng, Chia-Wei; Cao, Amanda Q.; Tripathi, Surya; Mana, Miyeko D.; Bauer-Rowe, Khristian E.; Abu-Remaileh, Monther; Clavain, Laura; Erdemir, Aysegul; Lewis, Caroline A.; Freinkman, Elizaveta; Dickey, Audrey S.; La Spada, Albert R.; Huang, Yanmei; Bell, George W.; Deshpande, Vikram; Carmeliet, Peter; Katajisto, Pekka; Sabatini, David M.; Yilmaz, Ömer H. (2018)
    Diet has a profound effect on tissue regeneration in diverse organisms, and low caloric states such as intermittent fasting have beneficial effects on organismal health and age-associated loss of tissue function. The role of adult stem and progenitor cells in responding to short-term fasting and whether such responses improve regeneration are not well studied. Here we show that a 24 hr fast augments intestinal stem cell (ISC) function in young and aged mice by inducing a fatty acid oxidation (FAO) program and that pharmacological activation of this program mimics many effects of fasting. Acute genetic disruption of Cpt1a, the rate-limiting enzyme in FAO, abrogates ISC-enhancing effects of fasting, but long-term Cpt1a deletion decreases ISC numbers and function, implicating a role for FAO in ISC maintenance. These findings highlight a role for FAO in mediating pro-regenerative effects of fasting in intestinal biology, and they may represent a viable strategy for enhancing intestinal regeneration.
  • Järvinen, Janina (Helsingin yliopisto, 2021)
    Current treatments for major depressive disorder have notable limitations including the delay achieving the therapeutic effect. Ketamine has been shown to alleviate the symptoms of depression rapidly and promising findings have also been found when using nitrous oxide. However, the mechanisms behind rapid antidepressant effect are not fully discovered. It seems that rapid-acting treatments alter brain energy metabolism, enhance synaptic plasticity, and repair neuronal dysfunction connected to depression. Particularly, the activation of brain derived neurotrophic factor (BDNF) mediated tropomyosin receptor kinase B (TrkB) signaling has been connected to rapid antidepressant effect. Fasting is also known to induce BDNF production and it is thought to activate BDNF-TrkB signaling. In addition, both of these treatments alter the brain energy metabolism. The objective of this study was to find out how fasting and nitrous oxide alone and in combination affect the rapid antidepressant effect and synaptic plasticity related BDNF-TrkB signaling in mice. Another aim of the research was to determine whether the body temperature changes after these treatments as a marker of metabolic rate. The analyzed brain samples of the mice were collected 15 minutes after cessation of nitrous oxide administration. As a result, it was found that the fasting protocol used in this study did not activate the studied BDNF-TrkB signaling. However, after nitrous oxide administration, the studied signaling and markers related to synaptic plasticity were partly activated. The results from the combination of nitrous oxide and fasting were similar compared to nitrous oxide administration only. It is therefore conceivable, that the effects were caused exclusively by nitrous oxide. Furthermore, a fascinating finding related to energy metabolism was that nitrous oxide reduced the body temperature of the mice significantly 15 minutes after cessation of the gas administration. Overall, these results are promising and consistent with previous research indicating that nitrous oxide administration could be related to induced synaptic plasticity and therefore have antidepressant associated effects. Nitrous oxide could be used to understand the mechanisms behind rapid antidepressant effect and it could be a potential option to treat depression in the future. Based on these results, it seems that energy metabolism could be related to rapid antidepressant effect. It also supports the observations that all different rapid-acting treatments alter the brain energy metabolism.
  • International Group for Diabetes and Ramadan (IGRD) (2015)
    OBJECTIVE: To determine if individualized education before Ramadan results in a safer fast for people with type 2 diabetes. METHODS: Patients with type 2 diabetes who received care from participating clinics in Egypt, Iran, Jordan and Saudi Arabia and intended to fast during Ramadan 2014 were prospectively studied. Twelve clinics participated. Individualized education addressed meal planning, physical activity, blood glucose monitoring and acute metabolic complications and when deemed necessary, provided an individualized diabetes treatment plan. RESULTS: 774 people met study criteria, 515 received individualized education and 259 received usual care. Those who received individualized education were more likely to modify their diabetes treatment plan during Ramadan (97% vs 88%, p<0.0001), to perform self-monitoring of blood glucose at least twice daily during Ramadan (70% vs 51%, p<0.0001), and to have improved knowledge about hypoglycemic signs and symptoms (p=0.0007). Those who received individualized education also reduced their body mass index (-1.1±2.4 kg/m(2) vs -0.2±1.7 kg/m(2), p<0.0001) and glycated haemoglobin (-0.7±1.1% vs -0.1±1.3%, p<0.0001) during Ramadan compared those who received usual care. There were more mild (77% vs 67%, p=0.0031) and moderate (38% vs 19%, p<0.0001) hypoglycemic events reported by participants who received individualized education than those who received usual care, but fewer reported severe hypoglycemic events during Ramadan (23% vs 34%, p=0.0017). CONCLUSIONS: This individualized education and diabetes treatment program helped patients with type 2 diabetes lose weight, improve glycemic control and achieve a safer fast during Ramadan.
  • Tikkanen, Emmi; Minicocci, Ilenia; Hällfors, Jenni; Di Costanzo, Alessia; D'Erasmo, Laura; Poggiogalle, Eleonora; Donini, Lorenzo Maria; Wurtz, Peter; Jauhiainen, Matti; Olkkonen, Vesa M.; Arca, Marcello (2019)
    Objective- Loss-of-function (LOF) variants in the ANGPTL3 (angiopoietin-like protein 3) have been associated with low levels of plasma lipoproteins and decreased coronary artery disease risk. We aimed to determine detailed metabolic effects of genetically induced ANGPTL3 deficiency in fasting and postprandial state. Approach and Results- We studied individuals carrying S17X LOF mutation in ANGPTL3 (6 homozygous and 32 heterozygous carriers) and 38 noncarriers. Nuclear magnetic resonance metabolomics was used to quantify 225 circulating metabolic measures. We compared metabolic differences between LOF carriers and noncarriers in fasting state and after a high-fat meal. In fasting, ANGPTL3 deficiency was characterized by similar extent of reductions in LDL (low-density lipoprotein) cholesterol (0.74 SD units lower concentration per LOF allele [95% CI, 0.42-1.06]) as observed for many TRL (triglyceride-rich lipoprotein) measures, including VLDL (very-low-density lipoprotein) cholesterol (0.75 [95% CI, 0.45-1.05]). Within most lipoprotein subclasses, absolute levels of cholesterol were decreased more than triglycerides, resulting in the relative proportion of cholesterol being reduced within TRLs and their remnants. Further, beta-hydroxybutyrate was elevated (0.55 [95% CI, 0.21-0.89]). Homozygous ANGPTL3 LOF carriers showed essentially no postprandial increase in TRLs and fatty acids, without evidence for adverse compensatory metabolic effects. Conclusions- In addition to overall triglyceride- and LDL cholesterol-lowering effects, ANGPTL3 deficiency results in reduction of cholesterol proportion within TRLs and their remnants. Further, ANGPTL3 LOF carriers had elevated ketone body production, suggesting enhanced hepatic fatty acid beta-oxidation. The detailed metabolic profile in human knockouts of ANGPTL3 reinforces inactivation of ANGPTL3 as a promising therapeutic target for decreasing cardiovascular risk.
  • Nissinen, Tuuli A.; Hentila, Jaakko; Fachada, Vasco; Lautaoja, Juulia H.; Pasternack, Arja; Ritvos, Olli; Kivelä, Riikka; Hulmi, Juha J. (2021)
    Blocking of myostatin and activins effectively counteracts muscle atrophy. However, the potential interaction with physical inactivity and fasting in the regulation of muscle protein synthesis is poorly understood. We used blockade of myostatin and activins by recombinant adeno-associated virus (rAAV)-mediated follistatin (FS288) overexpression in mouse tibialis anterior muscle. To investigate the effects on muscle protein synthesis, muscles were collected 7 days after rAAV-injection in the nighttime or in the daytime representing high and low levels of activity and feeding, respectively, or after overnight fasting, refeeding, or ad libitum feeding. Muscle protein synthesis was increased by FS288 independent of the time of the day or the feeding status. However, the activation of mTORC1 signaling by FS288 was attenuated in the daytime and by overnight fasting. FS288 also increased the amount of mTOR colocalized with lysosomes, but did not alter their localization toward the sarcolemma. This study shows that FS288 gene delivery increases muscle protein synthesis largely independent of diurnal fluctuations in physical activity and food intake or feeding status, overriding the physiological signals. This is important for eg cachectic and sarcopenic patients with reduced physical activity and appetite. The FS288-induced increase in mTORC1 signaling and protein synthesis may be in part driven by increased amount of mTOR colocalized with lysosomes, but not by their localization toward sarcolemma.