Gold Nanoparticles Supported on Ceria Nanoparticles Modulate Leukocyte-Endothelium Cell Interactions and Inflammation in Type 2 Diabetes.

Gold-ceria nanoparticles (Au/CeO2) are known to have antioxidant properties. However, whether these nanoparticles can provide benefits in type 2 diabetes mellitus (T2D) remains unknown. This work aimed to study the effects of Au/CeO2 nanoparticles at different rates of gold purity (10, 4.4, 1.79 and 0.82) on leukocyte-endothelium interactions and inflammation in T2D patients. Anthropometric and metabolic parameters, leukocyte-endothelium interactions, ROS production and NF-κB expression were assessed in 57 T2D patients and 51 healthy subjects. T2D patients displayed higher Body Mass Index (BMI) and characteristic alterations in carbohydrate and lipid metabolism. ROS production was increased in leukocytes of T2D patients and decreased by Au/CeO2 at 0.82% gold. Interestingly, Au/CeO2 0.82% modulated leukocyte-endothelium interactions (the first step in the atherosclerotic process) by increasing leukocyte rolling velocity and decreasing rolling flux and adhesion in T2D. A static adhesion assay also revealed diminished leukocyte-endothelium interactions by Au/CeO2 0.82% treatment. NF-κB (p65) levels increased in T2D patients and were reduced by Au/CeO2 treatment. Cell proliferation, viability, and apoptosis assays demonstrated no toxicity produced by Au/CeO2 nanoparticles. These results demonstrate that Au/CeO2 nanoparticles at 0.82% exert antioxidant and anti-inflammatory actions in the leukocyte-endothelium interaction of T2D patients, suggesting a protective role against the appearance of atherosclerosis and cardiovascular diseases when this condition exists.

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.

Does Empagliflozin Modulate Leukocyte-Endothelium Interactions, Oxidative Stress, and Inflammation in Type 2 Diabetes?

Sodium-glucose co-transporter 2 inhibitors (iSGLT2) have been linked to cardiovascular risk reduction in patients with type 2 diabetes (T2D). However, their underlying molecular mechanisms remain unclear. This study aimed to evaluate the effects of empagliflozin, a novel potent and selective iSGLT-2, on anthropometric and endocrine parameters, leukocyte-endothelium interactions, adhesion molecules, ROS production, and NFkB-p65 transcription factor expression. According to standard clinical protocols, sixteen T2D patients receiving 10 mg/day of empagliflozin were followed-up for 24 weeks. Anthropometric and analytical measurements were performed at baseline, 12 weeks, and 24 weeks. Interactions between polymorphonuclear leukocytes and human umbilical vein endothelial cells (HUVECs), serum levels of adhesion molecules (P-Selectin, VCAM-1 and ICAM-1) and pro-inflammatory cytokines (TNF-α, IL-1ß and IL-6), mitochondrial ROS levels, antioxidant enzymes (SOD1 and GPX1), and NFkB-p65 were measured. We observed a decrease in body weight, BMI, and HbA1C levels from 12 weeks of treatment, which became more pronounced at 24 weeks and was accompanied by a significant reduction in waist circumference and glucose. Leukocyte-endothelium interactions were reduced due to an enhancement in the leukocyte rolling velocity from 12 weeks onwards, together with a significant decrease in leukocyte rolling flux and adhesion at 24 weeks. Accordingly, a significant decrease in ICAM-1 levels, mitochondrial ROS levels, and IL-6 and NFkB-p65 expression was observed, as well as an increase in SOD1. This pilot study provides evidence of the anti-inflammatory and antioxidant properties of empagliflozin treatment in humans, properties which may underlie its beneficial cardiovascular effects.

MicroRNAs and Oxidative Stress: An Intriguing Crosstalk to Be Exploited in the Management of Type 2 Diabetes.

Type 2 diabetes is a chronic disease widespread throughout the world, with significant human, social, and economic costs. Its multifactorial etiology leads to persistent hyperglycemia, impaired carbohydrate and fat metabolism, chronic inflammation, and defects in insulin secretion or insulin action, or both. Emerging evidence reveals that oxidative stress has a critical role in the development of type 2 diabetes. Overproduction of reactive oxygen species can promote an imbalance between the production and neutralization of antioxidant defence systems, thus favoring lipid accumulation, cellular stress, and the activation of cytosolic signaling pathways, and inducing ß-cell dysfunction, insulin resistance, and tissue inflammation. Over the last few years, microRNAs (miRNAs) have attracted growing attention as important mediators of diverse aspects of oxidative stress. These small endogenous non-coding RNAs of 19-24 nucleotides act as negative regulators of gene expression, including the modulation of redox signaling pathways. The present review aims to provide an overview of the current knowledge concerning the molecular crosstalk that takes place between oxidative stress and microRNAs in the physiopathology of type 2 diabetes, with a special emphasis on its potential as a therapeutic target.

Association between Proinflammatory Markers, Leukocyte-Endothelium Interactions, and Carotid Intima-Media Thickness in Type 2 Diabetes: Role of Glycemic Control.

Glycated hemoglobin monitorization could be a tool for maintaining type 2 diabetes (T2D) under control and delaying the appearance of cardiovascular events. This cross-sectional study was designed to assess the role of glycemic control in modulating early-stage markers of cardiovascular complications. One hundred and eight healthy controls and 161 type 2 diabetic patients were recruited and distributed according to their glycemic control, setting the threshold at 6.5% (good control). Biochemical and anthropometrical parameters were registered during the initial visit, and peripheral blood was extracted to obtain polymorphonuclear cells and analyze inflammatory markers, adhesion molecules, leukocyte-endothelium interactions, and carotid intima-media thickness. Correlations between these parameters were explored. We found that inflammatory markers and adhesion molecules were augmented in type 2 diabetic subjects with poor glycemic control. Polymorphonuclear leukocytes interacted more with the endothelium in the diabetic population, and even more significantly in the poorly controlled subjects. In parallel, carotid intima-media thickness was also increased in the diabetic population, and the difference was greater among poorly controlled subjects. Finally, correlation measurement revealed that carotid intima-media thickness was related to glycemic control and lipid metabolism in diabetic patients. Our results suggest that glycemic control delays the onset of cardiovascular comorbidities in diabetic subjects.

Mitochondrial Alterations and Enhanced Human Leukocyte/Endothelial Cell Interactions in Type 1 Diabetes.

Type 1 diabetes has been associated with oxidative stress. This study evaluates the rates of oxidative stress, mitochondrial function, leukocyte-endothelium interactions and adhesion molecules in type 1 diabetic patients. The study population consisted of 52 diabetic patients and 46 body-composition and age-matched controls. We assessed anthropometric and metabolic parameters, oxidative stress and mitochondrial function by evaluating reactive oxygen species (ROS) production, mitochondrial ROS production, mitochondrial membrane potential and superoxide dismutase (SOD) and catalase (CAT) expression in polymorphonuclear leukocytes from type 1 diabetic patients. In addition, we evaluated interactions between leukocytes and human umbilical vein endothelial cells (HUVEC), and serum expression of adhesion molecules (P-selectin, VCAM-1 and ICAM-1), proinflammatory cytokines (IL-6 and TNFα) and myeloperoxidase (MPO). HbA1C and glucose levels were higher in diabetic patients than in control subjects, as expected. Mitochondrial function was altered and leukocyte-endothelium interactions were enhanced in diabetic patients, which was evident in the increase in total and mitochondrial ROS production, higher mitochondrial membrane potential, enhanced leukocyte rolling and adhesion, and decreased rolling velocity. Furthermore, we observed an increase in levels of adhesion molecules P-selectin, VCAM-1, and ICAM-1 in these subjects. In addition, type 1 diabetic patients exhibited an increase in proinflammatory mediators TNFα and MPO, and a decreased expression of SOD. The enhancement of leukocyte-endothelium interactions and proinflammatory markers correlated with glucose and HbA1Clevels. Mitochondrial alteration, oxidative stress, and enhanced leukocyte-endothelium interactions are features of type 1 diabetes and may be related to cardiovascular implications.

Relationship between PMN-endothelium interactions, ROS production and Beclin-1 in type 2 diabetes.

Type 2 diabetes is closely related to oxidative stress and cardiovascular diseases. In this study, we hypothesized that polymorphonuclear leukocytes (PMN)-endothelium interactions and autophagy are associated. We evaluated PMN-endothelial interactions, ROS production and autophagy parameters in 47 type 2 diabetic patients and 57 control subjects. PMNs from type 2 diabetic patients exhibited slower rolling velocity (p < 0.001), higher rolling flux (p < 0.001) and adhesion (p < 0.001) in parallel to higher levels of total (p < 0.05) and mitochondrial ROS (p < 0.05). When the protein expression of autophagy markers was analysed, an increase of Beclin-1 (p < 0.05), LC3I (p < 0.05), LC3II (p < 0.01) and LC3II/LC3I ratio (p < 0.05) was observed. Several correlations between ROS and leukocyte-endothelium parameters were found. Interestingly, in control subjects, an increase of Beclin-1 levels was accompanied by a decrease in the number of rolling (r = 0.561) and adhering PMNs (r = 0.560) and a rise in the velocity of the rolling PMNs (r = 0.593). In contrast, in the type 2 diabetic population, a rise in Beclin-1 levels was related to an increase in the number of rolling (r = 0.437), and adhering PMNs (r = 0.467). These results support the hypothesis that PMN-endothelium interactions, ROS levels and formation of autophagosomes, especially Beclin-1 levels, are enhanced in type 2 diabetes.