Proposed Tandem Effect of Physical Activity and Sirtuin 1 and 3 Activation in Regulating Glucose Homeostasis

Sirtuin dysregulation in Parkinson's disease: Implications of acetylation and deacetylation processes

Parkinson's disease (PD) is a progressive neurodegenerative condition that primarily affects motor function and is caused by a gradual decline of dopaminergic neurons in the brain's substantia pars compacta (Snpc) region. Multiple molecular pathways are involved in the pathogenesis, which results in impaired cellular functions and neuronal degeneration. However, the role of sirtuins, a type of NAD+-dependent deacetylase, in the pathogenesis of Parkinson's disease has recently been investigated. Sirtuins are essential for preserving cellular homeostasis because they control a number of biological processes, such as metabolism, apoptosis, and DNA repair. This review shed lights on the dysregulation of sirtuin activity in PD, highlighting the role that acetylation and deacetylation processes play in the development of the disease. Key regulators of protein acetylation, sirtuins have been found to be involved in the aberrant acetylation of vital substrates linked to PD pathology when their balance is out of balance. The hallmark characteristics of PD such as neuroinflammation, oxidative stress, and mitochondrial dysfunction have all been linked to the dysregulation of sirtuin expression and activity. Furthermore, we have also explored how the modulators of sirtuins can be a promising therapeutic intervention in the treatment of PD.

Effects of aquatic high intensity interval training on parameters of functional autonomy, mental health, and oxidative dysfunction in elderly subjects with type 2 diabetes

The present study investigated the effects of aquatic exercise on parameters of functional autonomy, mental health, and oxidative dysfunction in elderly patients with DM2. A total of 130 elderly were included in the longitudinal clinical study and were attributed to the non-diabetic group (n = 27) and diabetes the group (n = 22). Both groups participated in 24 sessions of Hydro-HIIT, 48 h before and after Hydro-HIIT, the GDLAM index, depression, and anxiety scores and markers of oxidative dysfunction were quantified. After intervention, GI decreased in both groups (non-diabetes group = -24%; diabetes group = -22%) (p < 0.05), markers of depression (-46%), anxiety (-60%), DCFH-DA (-55%), SOD (+59%), TNF-α (-37%) and IL-1 (-48%) in diabetes group (p < 0.05). The intervention with Hydro-HIIT improves aspects related to functional autonomy, mental health, and exerts consequently, a modulating effect on oxidative stress and inflammatory response in elderly people diagnosed with DM2.

Involvement of Sirtuin 1 in the Growth Hormone/Insulin-like Growth Factor 1 Signal Transduction and Its Impact on Growth Processes in Children

The regulation of growth processes in children depends on the synthesis of growth hormone (GH) and insulin-like growth factor 1 (IGF-1). Insulin-like growth factor 1, which is mainly secreted in the liver in response to GH, is the main peripheral mediator of GH action. Newly discovered factors regulating GH secretion and its effects are being studied recently. One of them is sirtuin 1 (SIRT1). This NAD+-dependent deacetylase, by modulating the JAK2/STAT pathway, is involved in the transduction of the GH signal in hepatocytes, leading to the synthesis of IGF-1. In addition, it participates in the regulation of the synthesis of GHRH in the hypothalamus and GH in the somatotropic cells. SIRT1 is suggested to be involved in growth plate chondrogenesis and longitudinal bone growth as it has a positive effect on the epiphyseal growth plate. SIRT1 is also implicated in various cellular processes, including metabolism, cell cycle regulation, apoptosis, oxidative stress response, and DNA repair. Thus, its expression varies depending on the different metabolic states. During malnutrition, SIRT1 blocks GH signal transduction in hepatocytes to reduce the IGF-1 secretion and prevent hypoglycemia (i.e., it causes transient GH resistance). In this review, we focused on the influence of SIRT1 on GH signal transduction and the implications that may arise for growth processes in children.

Effect of resistance training and high-intensity interval training on metabolic parameters and serum level of Sirtuin1 in postmenopausal women with metabolic syndrome: a randomized controlled trial

BACKGROUND

The present study analyzes the influence of resistance training (RT) and high-intensity interval training (HIIT) on metabolic indices and serum levels of Sirtuin1 (SIRT1) in postmenopausal women who suffer from the metabolic syndrome (MetS).

METHODS

45 postmenopausal women aged 45-65 years with MetS were divided into two intervention groups (RT and HIIT) and one control group, each consisting of 15 people. The RT group performed resistance training for both the upper and lower body, while the HIIT group completed 3 min(min) of high-intensity training at 80-90% of their maximum heart rate (HRmax), followed by moderate walking for 3 min at 55-65% of HRmax. These sessions were conducted for a duration of eight weeks and three times a week, with the samples being collected at the baseline and at the end of the treatment, i.e., week 8.

RESULTS

The results showed that weight, waist circumference, body mass index, fat mass, low-density lipoprotein, triglyceride, cholesterol, fasting blood sugar (FBS), hemoglobin A1c (HbA1C), systolic and diastolic blood pressure decreased, and SIRT1 increased significantly in both training groups. Systolic blood pressure, cholesterol, HbA1C, and FBS decreased more in the HIIT group. Skeletal muscle mass and 1-repetition maximum (1-RM) increased more in the RT group.

CONCLUSIONS

RT and HIIT serve as one of the most effective strategies for therapeutically treating patients with metabolic syndrome.

TRIAL REGISTRATION

IRCT, IRCT20221120056548N1. Registered 23 November 2022 - Retrospectively registered.

Metabolic landscape in cardiac aging: insights into molecular biology and therapeutic implications

Cardiac aging is evident by a reduction in function which subsequently contributes to heart failure. The metabolic microenvironment has been identified as a hallmark of malignancy, but recent studies have shed light on its role in cardiovascular diseases (CVDs). Various metabolic pathways in cardiomyocytes and noncardiomyocytes determine cellular senescence in the aging heart. Metabolic alteration is a common process throughout cardiac degeneration. Importantly, the involvement of cellular senescence in cardiac injuries, including heart failure and myocardial ischemia and infarction, has been reported. However, metabolic complexity among human aging hearts hinders the development of strategies that targets metabolic susceptibility. Advances over the past decade have linked cellular senescence and function with their metabolic reprogramming pathway in cardiac aging, including autophagy, oxidative stress, epigenetic modifications, chronic inflammation, and myocyte systolic phenotype regulation. In addition, metabolic status is involved in crucial aspects of myocardial biology, from fibrosis to hypertrophy and chronic inflammation. However, further elucidation of the metabolism involvement in cardiac degeneration is still needed. Thus, deciphering the mechanisms underlying how metabolic reprogramming impacts cardiac aging is thought to contribute to the novel interventions to protect or even restore cardiac function in aging hearts. Here, we summarize emerging concepts about metabolic landscapes of cardiac aging, with specific focuses on why metabolic profile alters during cardiac degeneration and how we could utilize the current knowledge to improve the management of cardiac aging.

Cancer-associated fibroblast-secreted miR-421 promotes pancreatic cancer by regulating the SIRT3/H3K9Ac/HIF-1α axis

This study was designed to explore the effects of exosomal miR-421 secreted by cancer-associated fibroblasts (CAFs) on pancreatic cancer (PC) progression and the mechanisms involved. CAFs and exosomes (exos) were isolated and identified. PC cells were treated with CAF-derived exos (CAF-exos). Western blotting and quantitative polymerase chain reaction (qPCR) were used to measure miR-421, sirtuin-3 (SIRT3), and hypoxia duciblefactors-1 alpha (HIF-1α) levels. Cell counting kit-8 (CCK-8), wound-healing, and transwell migration assays were used to measure proliferation, migration, and invasion abilities of the cells. Dual-luciferase assay and RNA immunoprecipitation (RIP) experiment analyzed the relationship between miR-421 and SIRT3. Chromatin immunoprecipitation (f)-verified H3K9Ac enrichment in the HIF-1α promoter region. In vivo tumorigenesis experiments were performed to further explore the effects of exosomal miR-421 from CAFs on PC. CAFs and exos were successfully isolated. CAF-exo-treated PC cells highly expressed miR-421 and had increased cell proliferation, migration, and invasion abilities. Knocking down miR-421 increased the expression of SIRT3. SIRT3 is a target of miR-421, and inhibiting the expression of SIRT3 reversed the negative effects of miR-421 knockdown on PC cell. Knocking down miR-421 in CAF-exo inhibited the expression of HIF-1α in PC cells. Moreover, SIRT3-mediated HIF-1α expression by regulating H3K9Ac. HIF-1α overexpression reversed the inhibiting effects of SIRT3 overexpression on PC progression and counteracted the inhibiting effects of miR-421 knockdown on glycolysis. Moreover, in vivo tumorigenesis experiments showed that knocking down miR-421 attenuated CAF-exo induced tumor growth. Exosomal miR-421 from CAFs promoted PC progression by regulating the SIRT3/H3K9Ac/HIF-1α axis. This study provided insights into the molecular mechanism of PC.

Effect of training and crocin supplementation on mitochondrial biogenesis and redox-sensitive transcription factors in liver tissue of type 2 diabetic rats

Present study investigated the effect of continued training (CT) and interval training (IT) with crocin (C) supplementation on mitochondrial biogenesis and redox-sensitive transcription factors in liver tissue of type 2 diabetes (T2D) rats. Forty-eight high fat diet and streptozotocin- induced diabetic rats (mean age: 20 weeks, mean weight: 360.12 ± 12.11 g) were randomly divided into six groups including: (1) sham (Sh), (2) CT, (3) IT, (4) C (25 mg/kg/day), (5) CT + C, and (6) IT + C. IT and CT were performed 8 weeks for five sessions per week on treadmill with 80-85% and 50-55% of maximum speed running respectively. IT, CT and C decreased AP1 and increased LCAD (p ≤ .05); C increased SIRT1 (p ≤ .05); IT + C and CT + C decreased AP1 as well as increased NF-κB and LCAD (p ≤ .05); IT + C increased SIRT1, SIRST3 and PGC1-α (p ≤ .05). It appears that IT along with C compared to CT and C have favourable effect on mitochondrial biogenesis factors.

Association of genetic variants in the Sirt1 and Nrf2 genes with the risk of metabolic syndrome in a Chinese Han population

BACKGROUND

Metabolic syndrome (MetS) is a complex of interrelated risk factors, including central adiposity, increased blood pressure, hyperglycemia, elevated triglyceride levels and low high-density lipoprotein. Few studies have reported the genetic variants in the Sirt1 and Nrf2 genes (Sirt1 rs7895833 A > G, Sirt1 rs2273773 C > T and Nrf2 rs6721961 C > A) that increase the risk of type 2 diabetes mellitus and are correlated with some glycemic and metabolic traits in the Chinese Han population.

METHODS

Our study recruited 141 individuals with MetS and 549 individuals without MetS to investigate the associations between three single nucleotide polymorphisms (SNPs) of Sirt1 and Nrf2 and the risk of MetS in a Chinese Han population using the PCR-CTPP method.

RESULTS

This research showed that the risk of MetS was 2.41 times higher for the AA genotype (P = 0.038) and 1.94 times higher for the AG genotype (P = 0.016) compared with carriers of the GG genotype. The serum levels of low-density lipoprotein cholesterol and HOMA-IR were significantly higher (P < 0.05) in carriers of the AA genotype of Sirt1 rs7895833 than in carriers of the AG and GG genotypes in the general population. The serum level of total cholesterol in the AA genotype was lower (P = 0.033) than that in the other two genotypes. However, the genotype frequencies of Sirt1 rs2273773 and Nrf2 rs6721961 in the MetS group were not significantly different from those in the control subjects, and those two genetic variants were not correlated with metabolic traits.

CONCLUSIONS

These results underscore the contributions of SNPs of Sirt1 rs7895833 to MetS susceptibility as well as glycemic and metabolic traits in a Chinese population.

Correlations between serum sirtuin levels and cardiovascular risk factors in women with polycystic ovary syndrome

PURPOSE

Polycystic ovary syndrome (PCOS) is associated with an increased risk of cardiovascular disease (CVD) and metabolic complications often related to obesity, such as insulin resistance and type 2 diabetes mellitus (T2DM). Sirtuins (SIRTs) are nicotinamide adenine dinucleotide NAD⁺-dependent histone deacetylases, which modulate protein post-translational modifications (PTMs), gene transcription, increase repairing activities of DNA, and regulate metabolic processes. The aim of our study was to measure the serum levels of SIRTs 1, 2, 3, 6 and 7, and evaluate correlations between SIRTs levels and cardiovascular risk factors in women with PCOS.

PATIENTS AND METHODS

The study included 54 women with PCOS and 33 healthy volunteers. Concentrations of SIRTs were measured by ELISA technique.

RESULTS

Mean serum levels of SIRTs did not differ significantly between PCOS and controls. SIRTs 1, 2, and 6 positively correlated with HDL, while SIRTs 2 and 6 negatively correlated with LDL cholesterol. Negative correlation between SIRT 3 and HOMA-IR and negative correlations of SIRT 1 and 2 with insulin 120' in oral glucose tolerance test (OGTT) were demonstrated. A positive correlation between BMI and SIRT 7 concentration, and a positive correlation between body weight and SIRT 7 concentration were verified in the study group. The observed correlations between concentrations of SIRTs and metabolic parameters may indicate the involvement of these factors in the development of cardiometabolic complications.

CONCLUSIONS

The results may indicate the involvement of SIRTs in the development of cardiometabolic complications. However, additional studies are required to validate this observation.

Exercise as Treatment for Neuropathy in the Setting of Diabetes and Prediabetic Metabolic Syndrome: A Review of Animal Models and Human Trials

BACKGROUND

Peripheral neuropathy is among the most common complications of diabetes, but a phenotypically identical distal sensory predominant, painful axonopathy afflicts patients with prediabetic metabolic syndrome, exemplifying a spectrum of risk and continuity of pathogenesis. No pharmacological treatment convincingly improves neuropathy in the setting of metabolic syndrome, but evolving data suggest that exercise may be a promising alternative.

OBJECTIVE

The aim of the study was to review in depth the current literature regarding exercise treatment of metabolic syndrome neuropathy in humans and animal models, highlight the diverse mechanisms by which exercise exerts beneficial effects, and examine adherence limitations, safety aspects, modes and dose of exercise.

RESULTS

Rodent models that recapitulate the organismal milieu of prediabetic metabolic syndrome and the phenotype of its neuropathy provide a strong platform to dissect exercise effects on neuropathy pathogenesis. In these models, exercise reverses hyperglycemia and consequent oxidative and nitrosative stress, improves microvascular vasoreactivity, enhances axonal transport, ameliorates the lipotoxicity and inflammatory effects of hyperlipidemia and obesity, supports neuronal survival and regeneration following injury, and enhances mitochondrial bioenergetics at the distal axon. Prospective human studies are limited in scale but suggest exercise to improve cutaneous nerve regenerative capacity, neuropathic pain, and task-specific functional performance measures of gait and balance. Like other heath behavioral interventions, the benefits of exercise are limited by patient adherence.

CONCLUSION

Exercise is an integrative therapy that potently reduces cellular inflammatory state and improves distal axonal oxidative metabolism to ameliorate features of neuropathy in metabolic syndrome. The intensity of exercise need not improve cardinal features of metabolic syndrome, including weight, glucose control, to exert beneficial effects.

Therapeutic Effects of Sirtuin 1 Activator on Glaucoma Mice and the Regulation Mechanism of Mitogen-Activated Protein Kinase Pathway

The study focused on the therapeutic effects of resveratrol, sirtuin 1 (Sirt1) activator, on glaucoma, and its influence on mitogen-activated protein kinase (MAPK) pathway. Specifically, C57BL/6 mice were used and the glaucoma mouse model was established by intraperitoneal injection of N-methyl-D-aspartate (NMDA). According to different treatment methods, they were randomly rolled into 3 groups: control group (no treatment), model group (glaucoma mouse model), and resveratrol (Res) group (intraperitoneal injection of 20 mg/kg resveratrol solution on the basis of model group). The intraocular pressure was measured, and Sirt1 mRNA and protein expression was detected using reverse transcription-polymerase chain reaction (RT-PCR) and Western blot. Subsequently, hematoxylin-eosin staining was used to observe histopathological morphology, the immunofluorescence labeling was used to identify retinal survival ganglia, and Terminal deoxynucleotidyl transferase-mediated dUTP-biotin nick end labeling assay (TUNEL) and Western blot were for apoptotic cells determination and the expression of c-Jun N-terminal kinase (JNK), extracellular regulated protein kinase (ERK), and p38 protein in mitogen-activated protein kinase (MAPK) pathway, respectively. The model group showed lower intraocular pressure, Sirt1 mRNA and protein expression, number of survival retinal ganglion cells (RGCs), and thinner retina versus the control group (P < 0.05), but number of apoptotic RGCs and the phosphorylation levels of the three kinds of protein were higher (P < 0.05), and it exhibited no notable difference from the Res group (P > 0.05). Also, compared with the control group, the number of survival RGCs in the Res group was reduced (P < 0.05), but no notable difference was noted in the retinal thickness, the number of apoptotic RGCs, and the phosphorylation levels of the three kinds of protein (P > 0.05). In conclusion, resveratrol, the Sirt1 activator, can inhibit RGCs apoptosis through the MAPK signaling pathway and improve the pathological manifestations of glaucoma animal models, thus playing a protective role of the retina.

Impact of Dietary Modifications on Plasma Sirtuins 1, 3 and 5 in Older Overweight Individuals Undergoing 12-Weeks of Circuit Training

Sirtuins are nicotinamide adenine dinucleotide (NAD+)-dependent deacetylases that regulate numerous pathways such as mitochondrial energy metabolism in the human body. Lower levels of these enzymes were linked to diseases such as diabetes mellitus and were also described as a result of aging. Sirtuins were previously shown to be under the control of exercise and diet, which are modifiable lifestyle factors. In this study, we analyzed SIRT1, SIRT3 and SIRT5 in blood from a subset of healthy elderly participants who took part in a 12-week randomized, controlled trial during which they performed, twice-weekly, resistance and aerobic training only (EX), the exercise routine combined with dietary counseling in accordance with the guidelines of the German Nutrition Society (EXDC), the exercise routine combined with intake of 2 g/day oil from Calanus finmarchicus (EXCO), or received no treatment and served as the control group (CON). In all study groups performing exercise, a significant increase in activities of SIRT1 (EX: +0.15 U/mg (+0.56/−[−0.16]), EXDC: +0.25 U/mg (+0.52/−0.06), EXCO: +0.40 U/mg (+0.88/−[−0.12])) and SIRT3 (EX: +0.80 U/mg (+3.18/−0.05), EXDC: 0.95 U/mg (+3.88/−0.55), EXCO: 1.60 U/mg (+2.85/−0.70)) was detected. Group comparisons revealed that differences in SIRT1 activity in EXCO and EXDC differed significantly from CON (CON vs. EXCO, p = 0.003; CON vs. EXDC, p = 0.010). For SIRT3, increases in all three intervention groups were significantly different from CON (CON vs. EX, p = 0.007; CON vs. EXDC, p < 0.001, CON vs. EXCO, p = 0.004). In contrast, differences in SIRT5-activities were less pronounced. Altogether, the analyses showed that the activity of SIRT1 and SIRT3 increased in response to the exercise intervention and that this increase may potentially be enhanced by additional dietary modifications.

Sirtuin 1 in Endothelial Dysfunction and Cardiovascular Aging

Sirtuin 1 (SIRT1) is a histone deacetylase belonging to the family of Sirtuins, a class of nicotinamide adenine dinucleotide (NAD+)-dependent enzymes with multiple metabolic functions. SIRT1 localizes in the nucleus and cytoplasm, and is implicated in the regulation of cell survival in response to several stimuli, including metabolic ones. The expression of SIRT1 is associated with lifespan and is reduced with aging both in animal models and in humans, where the lack of SIRT1 is regarded as a potential mediator of age-related cardiovascular diseases. In this review, we will summarize the extensive evidence linking SIRT1 functional and quantitative defects to cellular senescence and aging, with particular regard to their role in determining endothelial dysfunction and consequent cardiovascular diseases. Ultimately, we outline the translational perspectives for this topic, in order to highlight the missing evidence and the future research steps.

Role of SIRT1 in Neuropathic Pain from the Viewpoint of Neuroimmunity

The current clinical first-line treatment of neuropathic pain still considers only the nervous system as the target, and its therapeutic effect is limited. An increasing number of studies support the opinion that neuropathic pain is a result of the combined action of the sensory nervous system and the related immune system. Under physiological conditions, both the nervous system and the immune system can maintain homeostasis by adjusting the mitochondrial function when sensing noxious stimulation. However, in the case of neuropathic pain, mitochondrial regulatory dysfunction occurs, which may result from the decreased expression of SIRT1. In this study, we review the role of SIRT1 in neuropathic pain from the viewpoint of neuroimmunity.

The Emerging Role of HDACs: Pathology and Therapeutic Targets in Diabetes Mellitus

Diabetes mellitus (DM) is one of the principal manifestations of metabolic syndrome and its prevalence with modern lifestyle is increasing incessantly. Chronic hyperglycemia can induce several vascular complications that were referred to be the major cause of morbidity and mortality in DM. Although several therapeutic targets have been identified and accessed clinically, the imminent risk of DM and its prevalence are still ascending. Substantial pieces of evidence revealed that histone deacetylase (HDAC) isoforms can regulate various molecular activities in DM via epigenetic and post-translational regulation of several transcription factors. To date, 18 HDAC isoforms have been identified in mammals that were categorized into four different classes. Classes I, II, and IV are regarded as classical HDACs, which operate through a Zn-based mechanism. In contrast, class III HDACs or Sirtuins depend on nicotinamide adenine dinucleotide (NAD+) for their molecular activity. Functionally, most of the HDAC isoforms can regulate β cell fate, insulin release, insulin expression and signaling, and glucose metabolism. Moreover, the roles of HDAC members have been implicated in the regulation of oxidative stress, inflammation, apoptosis, fibrosis, and other pathological events, which substantially contribute to diabetes-related vascular dysfunctions. Therefore, HDACs could serve as the potential therapeutic target in DM towards developing novel intervention strategies. This review sheds light on the emerging role of HDACs/isoforms in diabetic pathophysiology and emphasized the scope of their targeting in DM for constituting novel interventional strategies for metabolic disorders/complications.

Dietary and Protective Factors to Halt or Mitigate Progression of Autoimmunity, COVID-19 and Its Associated Metabolic Diseases

COVID-19 is without any doubt the worst pandemic we have faced since the H1N1 virus outbreak. Even if vaccination against SARS-CoV-2 infection is becoming increasingly available, a more feasible approach for COVID-19 prevention and therapy is still needed. Evidence of a pathological link between metabolic diseases and severe forms of COVID-19 has stimulated critical reflection and new considerations. In particular, an abnormal immune response observed in certain patients with SARS-CoV-2 infection suggested possible common predisposing risk factors with autoimmune diseases such as Type 1 Diabetes (T1D). Correct supplementation with dietary factors may be key to preventing and counteracting both the underlying metabolic impairment and the complications of COVID-19. A set of agents may inhibit the cytokine storm and hypercoagulability that characterize severe COVID-19 infection: vitamin D3, omega-3 polyunsaturated fatty acids, polyphenols like pterostilbene, polydatin and honokiol, which can activate anti-inflammatory and antioxidant sirtuins pathways, quercetin, vitamin C, zinc, melatonin, lactoferrin and glutathione. These agents could be highly beneficial for subjects who have altered immune responses. In this review, we discuss the antiviral and metabolic effects of these dietary factors and propose their combination for potential applications in the prevention and treatment of COVID-19. Rigorous studies will be fundamental for validating preventive and therapeutic protocols that could be of assistance to mitigate disease progression following SARS-CoV-2 infection.

Decreased insulin resistance in diabetic patients by influencing Sirtuin1 and Fetuin-A following supplementation with ellagic acid: a randomized controlled trial

BACKGROUND

The beneficial effects of polyphenols have been reported. This study aimed to investigate the effect of oral Ellagic acid (EA) supplement on insulin resistance (IR) and Fetuin-A and serum sirtuin1 (SIRT1) in type 2 diabetics.

METHODS

In this double-blind, randomized clinical trial, 44 diabetic patients were selected. Patients were assigned to the intervention group (22 subjects) and placebo (22 subjects) and received a capsule containing 180 mg of EA per day or placebo for eight weeks, respectively. At the beginning and end of the study, anthropometric indices, fasting plasma glucose (FPG), plasma insulin level, IR, Fetuin-A, and SIRT1 were measured. Statistical analysis was performed using SPSS software.

RESULTS

At the beginning and end of the study, there was no significant difference between the two groups regarding anthropometric indices (P > 0.05). At the end of the survey, EA supplementation significantly reduced FPG, insulin, IR, and Fetuin-A and increased SIRT1 levels compared with the placebo group (P < 0.05). However, these changes were not significant in the placebo group (P > 0.05).

CONCLUSION

EA with antioxidant properties plays an essential role in reducing the macrovascular and microvascular complications of diabetes by reducing inflammation and insulin resistance. Trial registration The protocol of this clinical trial is registered with the Iranian Registry of Clinical Trials ( http://www.IRCT.IR , identifier: IRCT20141025019669N13).

The Effect of Repeated Whole-Body Cryotherapy on Sirt1 and Sirt3 Concentrations and Oxidative Status in Older and Young Men Performing Different Levels of Physical Activity

Background: The activity of antioxidant enzymes and sirtuins (Sirt) decreases along with age, which is counteracted by aerobic training. Sirtuins increase antioxidant defence. Whole-body cryotherapy (WBC) increases total antioxidant capacity (TAC) in young men. The aim of our study was to assess the impact of 24 WBC treatments on the blood concentration of selected sirtuins and the level of antioxidant defence as well as oxidative stress index of training and non-training men depending on age. Methods: The study involved 40 males. In each group, there were 10 non-training older and young men (60 NTR and 20 NTR), and 10 older and young long-distance runners (60 TR, 20 TR). During an 8-week period, participants underwent 24 WBC treatments (3 min −130 °C), which were performed three times a week (Monday, Wednesday, Friday). The concentrations of Sirt1, Sirt3, TAC, total oxidative status and the activity of superoxide dismutase (SOD), catalase and glutathione peroxidase (GPx) in the blood were determined before 1 WBC and after 1 WBC, 12 WBC and 24 WBC. Results: After 1 WBC, the activity of GPx and the concentration of Sirt1 and TAC in 60 TR and TAC in 60 NTR increased. After 12 WBC, the level of Sirt1 in 20 NTR and SOD in 20 TR increased. After 24 WBC, the level of Sirt1 increased in 60 TR and in 20 NTR, Sirt3 in 60 TR and SOD in 20 TR. Conclusions: Cryogenic temperatures increase blood levels of Sirt1 and Sirt3 and systemic antioxidant defence in men, but the effect is dependent on age, level of performed physical activity and the number of applied treatments.

Tyrosol May Prevent Obesity by Inhibiting Adipogenesis in 3T3-L1 Preadipocytes

Tyrosol (TR), a major polyphenol found in extra virgin olive oil (EVOO), exerts several antioxidant effects. However, only scarce evidences are present regarding its activity on adipocytes and obesity. This study evaluated the role of TR in adipogenesis. Murine 3T3-L1 preadipocytes were incubated with TR (300 and 500 μM), and TR administration inhibited adipogenesis by downregulation of several adipogenic factors (leptin and aP2) and transcription factors (C/EBPα, PPARγ, SREBP1c, and Glut4) and by modulation of the histone deacetylase sirtuin 1. After complete differentiation, adipocytes treated with 300 and 500 μM TR showed a reduction of 20% and 30% in lipid droplets, respectively. Intracellular triglycerides were significantly reduced after TR treatment (p < 0.05). Mature adipocytes treated with TR at 300 and 500 μM showed a marked decrease in the inflammatory state and oxidative stress as shown by the modulation of specific biomarkers (TNF, IL6, ROS, and SOD2). TR treatment also acted on the early stage of differentiation by reducing cell proliferation (~40%) and inducing cell cycle arrest during Mitotic Expansion Clonal (first 48 h of differentiation), as shown by the increase in both S1 phase and p21 protein expression. We also showed that TR induced lipolysis by activating the AMPK-ATGL-HSL pathway. In conclusion, we provided evidence that TR reduces 3T3-L1 differentiation through downregulation of adipogenic proteins, inflammation, and oxidative stress. Moreover, TR may trigger adipose tissue browning throughout the induction of the AMPK-ATGL-UCP1 pathway and, subsequently, may have promise as a potential therapeutic agent for the treatment and prevention of obesity.

Alternatives to Insulin for the Regulation of Blood Sugar Levels in Type 2 Diabetes

This short overview focuses on the causation and treatment of type 2 diabetes (T2D). Emphasis is given to the historical basis of understanding this disease and the background leading to emergence of the central role of insulin. The strengths of insulin administration in the treatment of diabetes are profound, but these need to be balanced against several serious shortcomings of its extended use. Some alternative approaches to T2D management are considered. Insulin is no longer considered as the first choice for type 2 diabetes, and an expanding range of new therapeutic possibilities is emerging. While these may lack the potency of insulin, at a minimum, they allow a major reduction in the intensity of insulin use. In view of the rising worldwide incidence of this disease, it is imperative to develop safe and inexpensive means of limiting its potential for impairment of normal functioning.

Mechanism of Action of Ketogenic Diet Treatment: Impact of Decanoic Acid and Beta-Hydroxybutyrate on Sirtuins and Energy Metabolism in Hippocampal Murine Neurons

The ketogenic diet (KD), a high-lipid and low-carbohydrate diet, has been used in the treatment of epilepsy, neurodegenerative disorders, inborn errors of metabolism and cancer; however, the exact mechanism/s of its therapeutic effect is not completely known. We hypothesized that sirtuins (SIRT)—a group of seven NAD-dependent enzymes and important regulators of energy metabolism may be altered under KD treatment. HT22 hippocampal murine neurons were incubated with two important KD metabolites–beta-hydroxybutyrate (BHB) (the predominant ketone body) and decanoic acid (C10), both accumulating under KD. Enzyme activity, protein, and gene expressions of SIRT 1-4, enzyme capacities of the mitochondrial respiratory chain complexes (MRC), citrate synthase (CS) and gene expression of monocarboxylate transporters were measured in control (untreated) and KD-treated cells. Incubation with both–BHB and C10 resulted in significant elevation of SIRT1 enzyme activity and an overall upregulation of the MRC. C10 incubation showed prominent increases in maximal activities of complexes I + III and complex IV of the MRC and ratios of their activities to that of CS, pointing towards a more efficient functioning of the mitochondria in C10-treated cells.