The Mitochondria-Targeted Antioxidant MitoQ Modulates Mitochondrial Function and Endoplasmic Reticulum Stress in Pancreatic ß Cells Exposed to Hyperglycaemia.

BACKGROUND/AIMS: Mitochondria-targeted antioxidants such as mitoquinone (MitoQ) have demonstrated protective effects against oxidative damage in several diseases. The increase in reactive oxygen species (ROS) production during glucose metabolism in ß cells can be exacerbated under hyperglycaemic conditions such as type 2 diabetes (T2D), thus contributing to ß cell function impairment. In the present work, we aimed to evaluate the effect of MitoQ on insulin secretion, oxidative stress, endoplasmic reticulum (ER) stress and nuclear factor kappa B (NFκB) signalling in a pancreatic ß cell line under normoglycaemic (NG, 11.1 mM glucose), hyperglycaemic (HG, 25 mM glucose) and lipidic (palmitic acid (PA), 0.5mM) conditions. METHODS: We incubated the pancreatic ß cell line INS-1E with or without MitoQ (0.5µM) under NG, HG and PA conditions. We then assessed the following parameters: glucose-induced insulin secretion, O2 consumption (with a Clark-type electrode); mitochondrial function, oxidative stress parameters and calcium levels (by fluorescence microscopy); ER stress markers and NFκB-p65 protein levels (by western blotting). RESULTS: MitoQ increased insulin secretion and prevented the enhancement of ROS production and O2 consumption and decrease in GSH levels that are characteristic under HG conditions. MitoQ also reduced protein levels of ER stress markers (GRP78 and P-eIF2α) and the proinflammatory nuclear transcription factor NFκB-p65, both of which increased under HG. MitoQ did not significantly alter ER stress markers under lipidic conditions. CONCLUSION: Our findings suggest that treatment with MitoQ modulates mitochondrial function, which in turn ameliorates endoplasmic reticulum stress and NFκB activation, thereby representing potential benefits for pancreatic ß cell function.

Dietary weight loss intervention improves subclinical atherosclerosis and oxidative stress markers in leukocytes of obese humans.

BACKGROUND: The relationship between caloric restriction-mediated weight loss and the generation of ROS and its effects on atherosclerotic markers in obesity is not fully understood. Therefore, we set out to investigate whether dietary weight loss intervention improves markers of oxidative stress in leukocytes and subclinical parameters of atherosclerosis. SUBJECTS AND METHODS: This was an interventional study of 59 obese subjects (BMI > 35 kg/m2) who underwent 6 months of dietary therapy, including a 6-week very-low-calorie diet (VLCD) followed by an 18-week low-calorie diet (LCD). We determined clinical parameters, inflammatory markers-hsCRP, TNFα and NFκB -, oxidative stress parameters-total superoxide, glutathione, catalase activity and protein carbonyl groups-, soluble cellular adhesion molecules-sICAM, sP-selectin, sPSGL-1 -, myeloperoxidase (MPO), leukocyte-endothelium cell interactions-rolling flux, velocity and adhesion-and LDL subfractions, before and after the dietary intervention. RESULTS: After losing weight, an improvement was observed in the patients' anthropometric, blood pressure and metabolic parameters, and was associated with reduced inflammatory response (hsCRP, TNFα and NFκB). Oxidative stress parameters improved, since superoxide production and protein carbonyl content were reduced and antioxidant systems were enhanced. In addition, a significant reduction of subclinical markers of atherosclerosis-small and dense LDL particles, MPO, sP-selectin and leukocyte adhesion-and an increase in soluble PSGL-1 were reported. CONCLUSIONS: Our findings reveal that the improvement of subclinical atherosclerotic markers after dietary weight loss intervention is associated with a reduction of oxidative stress in leukocytes and inflammatory pathways, suggesting that these are the underlying mechanisms responsible for the reduced risk of cardiovascular disease in obese subjects after losing weight.

Malnutrition impairs mitochondrial function and leukocyte activation.

BACKGROUND: The aim of this study was to evaluate markers of inflammation, oxidative stress and endothelial function in a disease-related malnutrition (DRM) outpatient population. METHODS: For this cross-sectional study, a total of 83 subjects were included and clustered in 3 groups: 34 with normonutrition (NN), 21 with DRM without inflammation (DRM-I) and 28 with DRM and inflammation (DRM + I). Nutritional diagnosis was conducted for all subjects according to ASPEN. Biochemical parameters, proinflammatory cytokines, reactive oxygen species production, glutathione, mitochondrial membrane potential, oxygen consumption, adhesion molecules and leukocyte-endothelium interactions were evaluated. RESULTS: DRM + I patients showed lower albumin, prealbumin, transferrin, and retinol-binding protein levels with respect to the NN group (p < 0.05), differences that were less noticeable in the DRM-I group. DRM + I was associated with a significant increase in hsCRP and IL6 vs the NN and DRM-I groups, and TNFα was increased in both DRM vs NN. DRM was characterised by increased oxidative stress, which was marked by a significant increase in ROS levels and a decrease in mitochondrial membrane potential in the DRM + I group. An evident reduction in mitochondrial oxygen consumption and glutathione concentration was observed in both DRM groups, and was accompanied by increased leukocyte adhesion and adhesion molecules and decreased rolling velocity in the DRM + I group. Furthermore, percentage of weight loss was negatively correlated with albumin, prealbumin, transferrin, O2 consumption, glutathione and leukocyte rolling velocity, and positively correlated with hsCRP, IL6, TNFα, ROS, leukocyte adhesion, and VCAM-1. CONCLUSIONS: Our results show that DRM is associated with oxidative stress and an inflammatory state, with a deterioration of endothelial dysfunction in the DRM + I population.

Obesity impairs leukocyte-endothelium cell interactions and oxidative stress in humans.

BACKGROUND: To evaluate the relationship between leukocyte-endothelial cell interactions and oxidative stress parameters in non-diabetic patients with different grades of obesity. MATERIAL AND METHODS: For this cross-sectional study, 225 subjects were recruited from January 1, 2014 to December 31, 2016 and divided into groups according to BMI (<30 kg/m2 , 30-40 kg/m2 and >40 kg/m²). We determined clinical parameters, systemic inflammatory markers, soluble cellular adhesion molecules, leukocyte-endothelium cell interactions-rolling flux, velocity and adhesion-, oxidative stress parameters-total ROS, total superoxide, glutathione-and mitochondrial membrane potential in leukocytes. RESULTS: We verified that HOMA-IR and hsCRP increased progressively as obesity developed, whereas A1c, IL6 and TNFα were augmented in the BMI > 40 kg/m² group. The cellular adhesion molecule sP-selectin was increased in patients with obesity, while sICAM, total ROS, total superoxide and mitochondrial membrane potential were selectively higher in the BMI > 40 kg/m² group. Obesity induced a progressive decrease in rolling velocity and an enhancement of rolling flux and leukocyte adhesion. CONCLUSION: Our findings reveal that endothelial dysfunction markers are altered in human obesity and are associated with proinflammatory cytokines and increased oxidative stress parameters.

Chronic periodontitis impairs polymorphonuclear leucocyte-endothelium cell interactions and oxidative stress in humans.

AIM: To evaluate the relationship between oxidative stress parameters in polymorphonuclear leucocytes (PMNs) and PMN-endothelial cell interactions in patients with chronic periodontitis (CP) according to different degrees of severity of the disease. MATERIALS AND METHODS: For this cross-sectional study, 182 subjects were divided into four groups according to degree of CP: without CP (n = 37), mild CP (n = 59), moderate CP (n = 51), and severe CP (n = 35). We determined anthropometric and biochemical variables, periodontal parameters, inflammatory markers, oxidative stress parameters (superoxide and mitochondrial membrane potential), and PMN-endothelium cell interactions (rolling flux, velocity, and adhesion). RESULTS: Systemic inflammatory markers-C-reactive protein, leucocyte count, TNFα, and retinol-binding protein 4-were altered in the group with CP. Total superoxide was augmented in patients with moderate and severe periodontitis, whereas mitochondrial membrane potential did not change. Furthermore, PMNs adhesion and rolling flux were increased in subjects with CP. CONCLUSION: In a systemic proinflammatory environment, PMNs from patients with CP exhibit hyperactivity and produce higher amounts of superoxide. In parallel with this, an increase in PMNs rolling flux and cell adhesion to the endothelium suggests the presence of alterations of PMN-endothelium interactions in patients with CP that can lead to atherosclerosis and cardiovascular complications.

Dietary therapy and non-surgical periodontal treatment in obese patients with chronic periodontitis.

AIM: The effect of dietary weight loss intervention on periodontal therapy is unknown. Therefore, we aimed to evaluate whether weight loss improves the response of obese subjects to non-surgical periodontal treatment. MATERIALS AND METHODS: This interventional study in obese patients was conducted at the University Hospital Dr. Peset (Valencia, Spain). Patients were divided into two groups with and without dietary therapy. All participants received non-surgical periodontal treatment. Periodontal, anthropometric and biochemical parameters were assessed at baseline and 12 weeks. RESULTS: A total of 78 patients were re-evaluated after intervention. All periodontal parameters improved in both groups after periodontal treatment, but the reductions in mean probing depth (PD) (0.23 mm vs. 0.12 mm) and in percentage of sites with PD 4-5 mm (10.4% vs. 5.89%) were significantly higher in the dietary group. Additionally, complement component 3 (C3) and tumour necrosis factor alpha (TNFα) decreased in the dietary group after intervention. Percentage of change in mean PD correlated with change in C3 (r = 0.233, p = 0.043), and percentage of change in sites with PD 4-5 mm correlated with change in TNFα (r = 0.414, p = 0.012). CONCLUSIONS: This study suggests that dietary weight loss intervention causes a greater reduction in systemic inflammation, which may enhance the response to periodontal treatment.

Levels of serum retinol-binding protein 4 before and after non-surgical periodontal treatment in lean and obese subjects: An interventional study.

AIM: We aimed to evaluate serum RBP4 levels before and after periodontal therapy in lean and obese subjects with chronic periodontitis (CP) in order to determine its possible association with periodontitis. MATERIALS AND METHODS: This is an interventional study for which a total of 112 lean and 119 obese subjects were recruited. Patients with CP were evaluated before and after three months of non-surgical periodontal treatment. Periodontal, anthropometric, biochemical parameters and serum levels of TNF-α, IL-6, hs-CRP and RBP4 were assessed. RESULTS: Serum RBP4 levels were associated with an increased probability of periodontitis (OR = 1.60; 95% CI: 1.02-2.50), showing patients with CP to have higher RBP4 levels than those without CP in both lean and obese populations (3.35 vs 3.06 and 3.74 vs 3.21, respectively). Following periodontal treatment, RBP4 and TNF-α decreased, and all periodontal parameters improved to the same extent in both groups, except for number of teeth with probing depth (PD) ≥4 mm, which improved to a less extent in obese than in lean subjects. In the multivariable regression model, the number of teeth with PD ≥4 mm was independently associated with RBP4 (ß = 0.192). CONCLUSION: RBP4 was associated with chronic periodontitis before and after non-surgical periodontal treatment.

Involvement of insulin resistance in normoglycaemic obese patients with periodontitis: A cross-sectional study.

AIM: We explored the association between obesity and periodontitis with the aim of determining the possible role of insulin resistance (IR) in this relationship. MATERIALS AND METHODS: A total of 212 subjects-110 obese and 102 lean individuals-were evaluated for periodontal disease and divided according to IR: a lean group without IR (LWIR), an obese group without IR (OWIR), and an obese group with IR (OIR). Anthropometric, metabolic, inflammatory and periodontal parameters were evaluated. RESULTS: Periodontitis was more prevalent in obese (80.9%) than in lean subjects (41.2%), with the former group showing a risk of periodontitis sixfold that of the latter. Obese subjects as a whole displayed higher diastolic blood pressure, TNFα and hsCRP and lower HDL cholesterol than lean subjects. OIR had higher systolic blood pressure, glucose, insulin, HOMA-IR, A1c, triglycerides and number of teeth with PD ≥ 4 mm than OWIR, while other periodontal variables remained unaltered. The multivariable regression model showed that probing depth, bleeding on probing and HOMA-IR were independent predictors of number of teeth with PD ≥ 4 mm. CONCLUSION: Our data support an association between obesity and periodontitis, and point to a central role of IR. Periodontitis tends to be more extensive in obese patients with IR.

Involvement of leucocyte/endothelial cell interactions in anorexia nervosa.

BACKGROUND: Anorexia nervosa is a common psychiatric disorder in adolescence and is related to cardiovascular complications. Our aim was to study the effect of anorexia nervosa on metabolic parameters, leucocyte-endothelium interactions, adhesion molecules and proinflammatory cytokines. MATERIALS AND METHODS: This multicentre, cross-sectional, case-control study employed a population of 24 anorexic female patients and 36 controls. We evaluated anthropometric and metabolic parameters, interactions between leucocytes polymorphonuclear neutrophils (PMN) and human umbilical vein endothelial cells (HUVEC), proinflammatory cytokines such as tumour necrosis factor alpha (TNF-α) and interleukin-6 (IL-6) and soluble cellular adhesion molecules (CAMs) including E-selectin, vascular cell adhesion molecule-1 (VCAM-1) and intercellular adhesion molecule-1 (ICAM-1). RESULTS: Anorexia nervosa was related to a decrease in weight, body mass index, waist circumference, systolic blood pressure, glucose, insulin and HOMA-IR, and an increase in HDL cholesterol. These effects disappeared after adjusting for BMI. Anorexia nervosa induced a decrease in PMN rolling velocity and an increase in PMN rolling flux and PMN adhesion. Increases in IL-6 and TNF-α and adhesion molecule VCAM-1 were also observed. CONCLUSIONS: This study supports the hypothesis of an association between anorexia nervosa, inflammation and the induction of leucocyte-endothelium interactions. These findings may explain, in part at least, the increased risk of vascular disease among patients with anorexia nervosa.

Plasma lipidomics discloses metabolic syndrome with a specific HDL phenotype.

Lipidomics reveals a remarkable diversity of lipids in human plasma. In this study, we have performed an in-depth lipidomic analysis of human plasma from healthy individuals and subjects with metabolic syndrome (MetS) in order to determine the lipidomic profile that allows prognosis of a pathological subpopulation with altered high-density lipoprotein (HDL) metabolism. The MetS population was categorized as having pathological or nonpathological HDL. Anthropometric parameters, cardiovascular risk markers, and lipoprotein subclasses of HDL and low-density lipoproteins were also evaluated. Lipidomic analysis revealed 357 differential molecules that were clustered (k means) in the two groups. The molecules identified in the whole lipidome showed that MetS subjects presented lower levels of glycerolipids and higher levels of glycerophospholipids with respect to control subjects. In contrast, when only statistically differential lipids were taken into account, differences were found between the two groups in almost cases. Furthermore, levels of saturated fatty acids were higher in patients with pathological HDL levels than in controls, whereas levels of unsaturated fatty acids were lower. These results highlight the potential of lipidomics as a clinical tool for risk assessment and monitoring of disease.

Perspectives and potential applications of mitochondria-targeted antioxidants in cardiometabolic diseases and type 2 diabetes.

There is abundant evidence to suggest that mitochondrial dysfunction is a main cause of insulin resistance and related cardiometabolic comorbidities. On the other hand, insulin resistance is one of the main characteristics of type 2 diabetes, obesity, and metabolic syndrome. Lipid and glucose metabolism require mitochondria to generate energy, and when O2 consumption is low due to inefficient nutrient oxidation, there is an increase in reactive oxygen species, which can impair different types of molecules, including DNA, lipids, proteins, and carbohydrates, thereby inducing proinflammatory processes. Factors which contribute to mitochondrial dysfunction, such as mitochondrial biogenesis and genetics, can also lead to insulin resistance in different insulin-target tissues, and its association with mitochondrial dysfunction can culminate in the development of cardiovascular diseases. In this context, therapies that improve mitochondrial function may also improve insulin resistance. This review explains mechanisms of mitochondrial function related to the pathological effects of insulin resistance in different tissues. The pathogenesis of cardiometabolic diseases will be explained from a mitochondrial perspective and the potential beneficial effects of mitochondria-targeted antioxidants as a therapy for modulating mitochondrial function in cardiometabolic diseases, especially diabetes, will also be considered.

Mitochondrial impairment and oxidative stress in leukocytes after testosterone administration to female-to-male transsexuals.

INTRODUCTION: Testosterone undecanoate (T) treatment is common in female-to-male transsexuals (FtMs) but can induce impairment of mitochondrial function and oxidative stress. AIM: The effect of T treatment on the mitochondrial function and redox state of leukocytes of FtMs subjects was evaluated. METHODS: This was an observational study conducted in a university hospital. Fifty-seven FtMs were treated with T (1,000 mg) for 12 weeks, after which anthropometric and metabolic parameters and mitochondrial function were evaluated. MAIN OUTCOME MEASURES: Anthropometric and metabolic parameters were evaluated. Mitochondrial function was studied by assessing mitochondrial oxygen (O2) consumption, membrane potential, reactive oxygen species (ROS) production, glutathione levels (GSH), and the reduced glutathione/oxidized glutathione (GSH)/(GSSG) ratio in polymorphonuclear cells. RESULTS: T treatment led to mitochondrial impairment in FtMs as a result of a decrease in mitochondria O2 consumption, the membrane potential, GSH levels, and the (GSH)/(GSSG) ratio and an increase in ROS production. Mitochondrial O2 consumption and membrane potential negatively correlated with T levels, which was further confirmed that the T treatment had induced mitochondrial dysfunction. T also produced a significant increase in total testosterone, free androgenic index, and atherogenic index of plasma, and a decrease in sex hormone-binding globulin and high-density lipoprotein cholesterol. CONCLUSIONS: Treatment of FtMs with T can induce impairment of mitochondrial function and a state of oxidative stress. This effect should be taken into account in order to modulate possible comorbidities in these patients.

Evidence for a relationship between mitochondrial Complex I activity and mitochondrial aldehyde dehydrogenase during nitroglycerin tolerance: effects of mitochondrial antioxidants.

The medical use of nitroglycerin (GTN) is limited by patient tolerance. The present study evaluated the role of mitochondrial Complex I in GTN biotransformation and the therapeutic effect of mitochondrial antioxidants. The development of GTN tolerance (in rat and human vessels) produced a decrease in mitochondrial O(2) consumption. Co-incubation with the mitochondria-targeted antioxidant mitoquinone (MQ, 10(-6)mol/L) or with glutathione ester (GEE, 10(-4)mol/L) blocked GTN tolerance and the effects of GTN on mitochondrial respiration and aldehyde dehydrogenase 2 (ALDH-2) activity. Biotransformation of GTN depended on the mitochondria being functionally active, particularly mitochondrial Complex I. Tolerance induced mitochondrial ROS production and oxidative stress, though these effects were not detected in HUVECρ(0) cells or Complex I mutant cells. Experiments performed to evaluate Complex I-dependent respiration demonstrated that its inhibition by GTN was prevented by the antioxidants in control samples. These results point to a key role for mitochondrial Complex I in the adequate functioning of ALDH-2. In addition, we have identified mitochondrial Complex I as one of the targets at which the initial oxidative stress responsible for GTN tolerance takes place. Our data also suggest a role for mitochondrial-antioxidants as therapeutic tools in the control of the tolerance that accompanies chronic nitrate use.

Influence of obesity on atherogenic dyslipidemia in women with polycystic ovary syndrome.

BACKGROUND: Obesity is known to underlie, at least partially, dyslipidemia in polycystic ovary syndrome (PCOS), but it is unclear whether PCOS status per se increases the risk of alterations of lipoprotein subfractions, which differ in size and atherogenic potential. Our objective was to evaluate whether PCOS influences lipoprotein profile and LDL and HDL subfractions and to study the impact of obesity on these parameters. MATERIALS AND METHODS: This was a case-control study conducted in an academic medical centre. The study population consisted of 54 women of fertile age with PCOS and 60 controls adjusted for age and BMI. Biochemical lipid profile and LDL and HDL lipoprotein subfractions (measured using Lipoprint System). RESULTS: Lean PCOS women exhibited lower HDL cholesterol and apolipoprotein AI levels than controls, although these differences were not associated with alterations of lipoprotein subfractions. All obese subjects, whether PCOS or controls, displayed lipid parameters typical of atherogenic dyslipidemia, although the former group had lower levels of large HDL, higher levels of small HDL subfractions and a higher percentage of VLDL than the latter. These differences were associated with a greater prevalence of non-A LDL pattern (25.0%) in obese PCOS subjects than in obese controls (4.3%). CONCLUSIONS: PCOS does not constitute an additional risk factor for cardiovascular disease in lean women, but leads to a lipid profile characteristic of atherogenic dyslipidemia and an altered pattern of lipoprotein subfraction when associated with obesity.

Mitochondrial Dysfunction and Mitophagy in Type 2 Diabetes: Pathophysiology and Therapeutic Targets.

Significance: Type 2 diabetes mellitus, which is related to oxidative stress and mitochondrial dysfunction, is one of the most prevalent diseases in the world. In the past decade, alterations in autophagy have been shown to play a fundamental role in the development and control of type 2 diabetes. Further, mitophagy has been recognized as a key player in eliminating dysfunctional mitochondria in this disease. Recent Advances: Recently, much progress has been made in understanding the molecular events associated with oxidative stress, mitochondrial dysfunction, and alterations in autophagy and mitophagy in type 2 diabetes. Critical Issues: Despite increasing evidence of a relationship between mitochondrial dysfunction, oxidative stress, and alterations of autophagy and mitophagy and their role in the pathophysiolology of type 2 diabetes, effective therapeutic strategies to combat the disease through targeting mitochondria, autophagy, and mitophagy are yet to be implemented. Future Directions: This review provides a wide perspective of the existing literature concerning the complicated interplay between autophagy, mitophagy, and mitochondrial dysfunction in type 2 diabetes. Further, potential therapeutic targets based on these molecular mechanisms are explored. Antioxid. Redox Signal. 39, 278-320.

Effects of GLP-1 receptor agonists on mitochondrial function, inflammatory markers and leukocyte-endothelium interactions in type 2 diabetes.

OBJECTIVE: Type 2 diabetes (T2D) is linked to metabolic, mitochondrial and inflammatory alterations, atherosclerosis development and cardiovascular diseases (CVDs). The aim was to investigate the potential therapeutic benefits of GLP-1 receptor agonists (GLP-1 RA) on oxidative stress, mitochondrial respiration, leukocyte-endothelial interactions, inflammation and carotid intima-media thickness (CIMT) in T2D patients. RESEARCH DESIGN AND METHODS: Type 2 diabetic patients (255) and control subjects (175) were recruited, paired by age and sex, and separated into two groups: without GLP-1 RA treatment (196) and treated with GLP-1 RA (59). Peripheral blood polymorphonuclear leukocytes (PMNs) were isolated to measure reactive oxygen species (ROS) production by flow cytometry and oxygen consumption with a Clark electrode. PMNs were also used to assess leukocyte-endothelial interactions. Circulating levels of adhesion molecules and inflammatory markers were quantified by Luminex's technology, and CIMT was measured as surrogate marker of atherosclerosis. RESULTS: Treatment with GLP-1 RA reduced ROS production and recovered mitochondrial membrane potential, oxygen consumption and MPO levels. The velocity of leukocytes rolling over endothelial cells increased in PMNs from GLP-1 RA-treated patients, whereas rolling and adhesion were diminished. ICAM-1, VCAM-1, IL-6, TNFα and IL-12 protein levels also decreased in the GLP-1 RA-treated group, while IL-10 increased. CIMT was lower in GLP-1 RA-treated T2D patients than in T2D patients without GLP-1 RA treatment. CONCLUSIONS: GLP-1 RA treatment improves the redox state and mitochondrial respiration, and reduces leukocyte-endothelial interactions, inflammation and CIMT in T2D patients, thereby potentially diminishing the risk of atherosclerosis and CVDs.

Effect of weight loss on C3 and C4 components of complement in obese patients.

BACKGROUND: Circulating C3 levels are elevated in obese patients, but how this factor is affected after weight loss through diet is a question that is yet unanswered. Therefore, the aim of this study was to evaluate the effects of weight loss on lipid and hydrocarbonated metabolism parameters and on the levels of C3 and C4 components of complement in obese patients. DESIGN: This is a longitudinal intervention study based on a 6-week very low-calorie diet (VLCD), a liquid formula of 603 kcal/day. A total of 131 middle-aged patients were distributed among grades II, III and IV of obesity. Anthropometric parameters, total cholesterol, triglycerides, high-density lipoprotein cholesterol, LDLc, apolipoproteins A-I and B-100, glucose, insulin, HOMA-IR and C3 and C4 levels were evaluated at baseline and after 6 weeks of intervention. RESULTS: After VLCD, the moderate weight loss was accompanied by a significant reduction in C3 levels in grade III and grade IV patients (10.2% and 15.4%, respectively; P < 0.001). C4 levels were not altered. Adherence to the diet improved anthropometric parameters and was accompanied by a significant decrease in all lipid profile parameters (P < 0.001). In addition, weight loss was associated with an improvement in hydrocarbonated metabolism as shown by the decrease in glucose levels and HOMA-IR (P < 0.01). CONCLUSIONS: Our findings show that in severely obese patients following a VLCD for 6 weeks produces reductions in factor C3, a biomarker of cardiovascular disease, and a significant improvement in some features of metabolic syndrome. In this way, the abovementioned diet may represent an effective strategy for treating obesity and related cardiovascular risk factors.

Metformin modulates mitochondrial function and mitophagy in peripheral blood mononuclear cells from type 2 diabetic patients.

Type 2 diabetes is a chronic metabolic disease that affects mitochondrial function. In this context, the rescue mechanisms of mitochondrial health, such as mitophagy and mitochondrial biogenesis, are of crucial importance. The gold standard for the treatment of type 2 diabetes is metformin, which has a beneficial impact on the mitochondrial metabolism. In this study, we set out to describe the effect of metformin treatment on mitochondrial function and mitophagy in peripheral blood mononuclear cells (PBMCs) from type 2 diabetic patients. We performed a preliminary cross-sectional observational study complying with CONSORT requirements, for which we recruited 242 subjects, divided into 101 healthy volunteers, 93 metformin-treated type 2 diabetic patients and 48 non-metformin-treated type 2 diabetic patients. Mitochondria from the type 2 diabetic patients not treated with metformin displayed more reactive oxygen species (ROS) than those from healthy or metformin-treated subjects. Protein expression of the electron transport chain (ETC) complexes was lower in PBMCs from type 2 diabetic patients without metformin treatment than in those from the other two groups. Mitophagy was altered in type 2 diabetic patients, evident in a decrease in the protein levels of PINK1 and Parkin in parallel to that of the mitochondrial biogenesis protein PGC1α, both of which effects were reversed by metformin. Analysis of AMPK phosphorylation revealed that its activation was decreased in the PBMCs of type 2 diabetic patients, an effect which was reversed, once again, by metformin. In addition, there was an increase in the serum levels of TNFα and IL-6 in type 2 diabetic patients and this was reversed with metformin treatment. These results demonstrate that metformin improves mitochondrial function, restores the levels of ETC complexes, and enhances AMPK activation and mitophagy, suggesting beneficial clinical implications in the treatment of type 2 diabetes.

Roux-en-Y Gastric Bypass Modulates AMPK, Autophagy and Inflammatory Response in Leukocytes of Obese Patients.

Obesity is characterized by low-grade chronic inflammation, metabolic overload, and impaired endothelial and cardiovascular function. Roux-en-Y gastric bypass (RYGB) results in amelioration of the pro-oxidant status of leukocytes and the metabolic profile. Nevertheless, little is known about the precise mechanism that drives systemic and metabolic improvements following bariatric surgery. In this cohort study, we investigated the effect of RYGB on molecular pathways involving energy homeostasis in leukocytes in 43 obese subjects one year after surgery. In addition to clinical and biochemical parameters, we determined protein expression of systemic proinflammatory cytokines by Luminex®, different markers of inflammation, endoplasmic reticulum (ER) stress, autophagy/mitophagy by western blot, and mitochondrial membrane potential by fluorescence imaging. Bariatric surgery induced an improvement in metabolic outcomes that was accompanied by a systemic drop in hsCRP, IL6, and IL1ß levels, and a slowing down of intracellular inflammatory pathways in leukocytes (NF-κB and MCP-1), an increase in AMPK content, a reduction of ER stress (ATF6 and CHOP), augmented autophagy/mitophagy markers (Beclin 1, ATG5, LC3-I, LC3-II, NBR1, and PINK1), and a decrease of mitochondrial membrane potential. These findings shed light on the specific molecular mechanisms by which RYGB facilitates metabolic improvements, highlighting the relevance of pathways involving energy homeostasis as key mediators of these outcomes. In addition, since leukocytes are particularly exposed to physiological changes, they could be used in routine clinical practice as a good sensor of the whole body's responses.

The Role of Mitochondrial Dynamic Dysfunction in Age-Associated Type 2 Diabetes.

Mitochondrial dynamics, such as fusion and fission, play a critical role in maintaining cellular metabolic homeostasis. The molecular mechanisms underlying these processes include fusion proteins (Mitofusin 1 [MFN1], Mitofusin 2 [MFN2], and optic atrophy 1 [OPA1]) and fission mediators (mitochondrial fission 1 [FIS1] and dynamin-related protein 1 [DRP1]), which interact with each other to ensure mitochondrial quality control. Interestingly, defects in these proteins can lead to the loss of mitochondrial DNA (mtDNA) integrity, impairment of mitochondrial function, a severe alteration of mitochondrial morphology, and eventually cell death. Emerging evidence has revealed a causal relationship between dysregulation of mitochondria dynamics and age-associated type 2 diabetes, a metabolic disease whose rates have reached an alarming epidemic-like level with the majority of cases (59%) recorded in men aged 65 and over. In this sense, fragmentation of mitochondrial networks is often associated with defects in cellular energy production and increased apoptosis, leading, in turn, to excessive reactive oxygen species release, mitochondrial dysfunction, and metabolic alterations, which can ultimately contribute to ß-cell dysfunction and insulin resistance. The present review discusses the processes of mitochondrial fusion and fission and their dysfunction in type 2 diabetes, with special attention given to the therapeutic potential of targeting mitochondrial dynamics in this complex metabolic disorder.