In vitro Evaluation of the Calcification Inhibitory Properties of Policosanol, Genistein, and Vitamin D (Reduplaxin®) either Alone or in Combination.

INTRODUCTION: The process of vascular calcification has severe clinical consequences in a number of diseases, including diabetes, atherosclerosis, and end-stage renal disease. In the present study, we investigated the effect of policosanol (Poli), genistein (Gen), and vitamin D (VitD) separately and in association to evaluate the possible synergistic action on inorganic phosphate (Pi)-induced calcification of vascular smooth muscle cells (VSMCs). METHODS: Primary human VSMCs were cultured with either growth medium or growth medium supplemented with calcium and phosphorus (calcification medium) in combination with Poli, Gen, and VitD. Alizarin Red staining, mineralization, and the protein expression of RUNX2 and superoxide dismutase-2 (SOD2) were investigated. RESULTS: All three substances tested were effective at reducing osteogenic differentiation of VSMCs in a dose-dependent manner. Poli+Gen, Poli+VitD, Gen+VitD treatment induced a greater inhibition of calcification and RUNX2 expression compared to single compounds treatments. Moreover, the association of Poli+Gen+VitD (Reduplaxin®) was more effective at inhibiting VSMCs mineralization and preventing the increase in RUNX2 expression induced by calcification medium but not modified SOD2 expression. CONCLUSIONS: The association of Pol, Gen, and VitD (Reduplaxin®) has an additive inhibitory effect on the calcification process of VSMCs induced in vitro by a pro-calcifying medium.

Renal Expression and Localization of the Receptor for (Pro)renin and Its Ligands in Rodent Models of Diabetes, Metabolic Syndrome, and Age-Dependent Focal and Segmental Glomerulosclerosis.

The (pro)renin receptor ((P)RR), a versatile protein found in various organs, including the kidney, is implicated in cardiometabolic conditions like diabetes, hypertension, and dyslipidemia, potentially contributing to organ damage. Importantly, changes in (pro)renin/(P)RR system localization during renal injury, a critical information base, remain unexplored. This study investigates the expression and topographic localization of the full length (FL)-(P)RR, its ligands (renin and prorenin), and its target cyclooxygenase-2 and found that they are upregulated in three distinct animal models of renal injury. The protein expression of these targets, initially confined to specific tubular renal cell types in control animals, increases in renal injury models, extending to glomerular cells. (P)RR gene expression correlates with protein changes in a genetic model of focal and segmental glomerulosclerosis. However, in diabetic and high-fat-fed mice, (P)RR mRNA levels contradict FL-(P)RR immunoreactivity. Research on diabetic mice kidneys and human podocytes exposed to diabetic glucose levels suggests that this inconsistency may result from disrupted intracellular (P)RR processing, likely due to increased Munc18-1 interacting protein 3. It follows that changes in FL-(P)RR cellular content mechanisms are specific to renal disease etiology, emphasizing the need for consideration in future studies exploring this receptor's involvement in renal damage of different origins.

Sustained increase in physical fitness independently predicts improvements in cardiometabolic risk profile in type 2 diabetes.

AIMS: To investigate the relationship between changes in physical fitness and cardiovascular risk factors and scores in patients with type 2 diabetes receiving either a behavioural counselling intervention to increase moderate-to-vigorous-intensity physical activity (MVPA) and decrease sedentary-time (SED-time) or standard care. MATERIALS AND METHODS: This is a pre-specified ancillary analysis of the Italian Diabetes and Exercise Study_2, a 3-year randomized clinical trial in which 300 physically inactive and sedentary patients were randomized 1:1 to receive either a one-month theoretical and practical counselling each year or standard care. Mean changes from baseline throughout the 3-year period in MVPA, SED-time, cardiorespiratory fitness (VO2max ), muscle strength, flexibility, cardiovascular risk factors and scores were calculated for study completers (n = 267) and considered irrespective of study arm. RESULTS: Haemoglobin (Hb) A1c and coronary heart disease (CHD) risk scores decreased with quartiles of VO2max and lower body muscle strength changes. Multivariable linear regression analysis showed that increases in VO2max independently predicted decreases in HbA1c , blood glucose, diastolic blood pressure (BP), CHD and total stroke 10-year risk and increases in HDL cholesterol, whereas increases in lower body muscle strength independently predicted decreases in body mass index (BMI), waist circumference, triglycerides, systolic BP, CHD and fatal stroke 10-year risk. These associations remained after including changes in BMI, waist circumference, fat mass and fat-free mass, or MVPA and SED-time as covariates. CONCLUSIONS: Improvement in physical fitness predicts favourable changes in cardiometabolic risk profile, independent of changes not only in (central) adiposity or body composition but also in MVPA and SED-time. TRIAL REGISTRATION: ClinicalTrials.gov; NCT01600937; URL https://clinicaltrials.gov/ct2/show/NCT01600937.

The advanced glycation end-product Nϵ -carboxymethyllysine promotes progression of pancreatic cancer: implications for diabetes-associated risk and its prevention.

Diabetes is an established risk factor for pancreatic cancer (PaC), together with obesity, a Western diet, and tobacco smoking. The common mechanistic link might be the accumulation of advanced glycation end-products (AGEs), which characterizes all of the above disease conditions and unhealthy habits. Surprisingly, however, the role of AGEs in PaC has not been examined yet, despite the evidence of a tumour-promoting role of receptor for advanced glycation end-products (RAGE), the receptor for AGEs. Here, we tested the hypothesis that AGEs promote PaC through RAGE activation. To this end, we investigated the effects of the AGE Nϵ -carboxymethyllysine (CML) in human pancreatic ductal adenocarcinoma (PDA) cell lines and in a mouse model of Kras-driven PaC interbred with a bioluminescent model of proliferation. Tumour growth was monitored in vivo by bioluminescence imaging and confirmed by histology. CML promoted PDA cell growth and RAGE expression, in a concentration-dependent and time-dependent manner, and activated downstream tumourigenic signalling pathways. These effects were counteracted by RAGE antagonist peptide (RAP). Exogenous AGE administration to PaC-prone mice induced RAGE upregulation in pancreatic intraepithelial neoplasias (PanINs) and markedly accelerated progression to invasive PaC. At 11 weeks of age (6 weeks of CML treatment), PaC was observed in eight of 11 (72.7%) CML-treated versus one of 11 (9.1%) vehicle-treated [control (Ctr)] mice. RAP delayed PanIN development in Ctr mice but failed to prevent PaC promotion in CML-treated mice, probably because of competition with soluble RAGE for binding to AGEs and/or compensatory upregulation of the RAGE homologue CD166/ activated leukocyte cell adhesion molecule, which also favoured tumour spread. These findings indicate that AGEs modulate the development and progression of PaC through receptor-mediated mechanisms, and might be responsible for the additional risk conferred by diabetes and other conditions characterized by increased AGE accumulation. Finally, our data suggest that an AGE reduction strategy, instead of RAGE inhibition, might be suitable for the risk management and prevention of PaC. Copyright © 2018 Pathological Society of Great Britain and Ireland. Published by John Wiley & Sons, Ltd.

Dietary interventions to contrast the onset and progression of diabetic nephropathy: A critical survey of new data.

This article is a critical overview of recent contributions on the dietary corrections and the foods that have been claimed to delay or hinder the onset of diabetic nephropathy (DN) and its progression to end-stage renal disease. Innovative dietary and behavioral approaches to the prevention and therapy of DN appear to be the most captivating in consideration of the rather well-established protocols for glucose and blood pressure control in use. In addition to restricted caloric intake to contrast obesity and the metabolic syndrome, adjustments in the patient's macronutrients intake, and in particular some degree of reduction in protein, have been long considered in the prevention of DN progression. More recently, the focus has shifted to the source of proteins and the content of glycotoxins in the diet as well as to the role of specific micronutrients. Few clinical trials have specifically addressed the role of those micronutrients associated with diet proteins that show the most protective effect against DN. Research on clinical outcome and mechanisms of action of such micronutrients appears the most promising in order to develop both effective intervention on nutritional education of the patient and selection of functional foods capable of contrasting the onset and progression of DN.

Role of Galectin-3 in Bone Cell Differentiation, Bone Pathophysiology and Vascular Osteogenesis.

Galectin-3 is expressed in various tissues, including the bone, where it is considered a marker of chondrogenic and osteogenic cell lineages. Galectin-3 protein was found to be increased in the differentiated chondrocytes of the metaphyseal plate cartilage, where it favors chondrocyte survival and cartilage matrix mineralization. It was also shown to be highly expressed in differentiating osteoblasts and osteoclasts, in concomitance with expression of osteogenic markers and Runt-related transcription factor 2 and with the appearance of a mature phenotype. Galectin-3 is expressed also by osteocytes, though its function in these cells has not been fully elucidated. The effects of galectin-3 on bone cells were also investigated in galectin-3 null mice, further supporting its role in all stages of bone biology, from development to remodeling. Galectin-3 was also shown to act as a receptor for advanced glycation endproducts, which have been implicated in age-dependent and diabetes-associated bone fragility. Moreover, its regulatory role in inflammatory bone and joint disorders entitles galectin-3 as a possible therapeutic target. Finally, galectin-3 capacity to commit mesenchymal stem cells to the osteoblastic lineage and to favor transdifferentiation of vascular smooth muscle cells into an osteoblast-like phenotype open a new area of interest in bone and vascular pathologies.

Protection from diabetes-induced atherosclerosis and renal disease by D-carnosine-octylester: effects of early vs late inhibition of advanced glycation end-products in Apoe-null mice.

AIMS/HYPOTHESIS: AGEs are involved in diabetic complications and might be responsible for the phenomenon of 'hyperglycaemic memory'. D-Carnosine-octylester (DCO) has been shown to attenuate AGE formation and vascular and renal injury induced by high-fat diet in Apoe-null mice. This study aimed to verify the protective effect of DCO in atherosclerosis and renal disease induced by experimental diabetes and to discover whether reduction of AGE formation by early vs late DCO treatment provides better macro and microvascular protection. METHODS: Apoe-null mice were rendered diabetic by streptozotocin and were left untreated or were treated with DCO for 20 weeks (DCO-Extended), from week 1 to 11 (DCO-Early) or from week 9 to 19 (DCO-Late). Non-diabetic Apoe-null mice served as controls. Aortic and renal lesions were evaluated by morphometry and protein and gene expression of disease markers were assessed by immunohistochemistry and real-time PCR. RESULTS: DCO-Extended treatment produced a more stable plaque phenotype by markedly attenuating diabetes-induced increases in lesion size, necrotic core area and plaque content of Nε-carboxymethyllysine, levels of apoptotic cells and markers of inflammation and oxidative stress and also reductions in collagen and smooth muscle cells. DCO treatment for 11 weeks afforded partial protection and this was significantly better in DCO-Early mice than in DCO-Late mice. Renal disease was attenuated in DCO-Extended mice and to a lesser extent in those treated for 11 weeks, with no significant difference between DCO-Early mice and DCO-Late mice. CONCLUSIONS/INTERPRETATION: These data show that DCO protects mice from diabetes-induced vascular and renal disease and that protection against atherosclerosis is more effectively achieved by early treatment than by late treatment, thus suggesting that early inhibition of AGE formation attenuates progression of macroangiopathy and favours development of more stable lesions.

Galectin-3: an emerging all-out player in metabolic disorders and their complications.

Galectin-3 has been increasingly recognized as an important modulator of several biological functions, by interacting with several molecules inside and outside the cell, and an emerging player in numerous disease conditions. Galectin-3 exerts various and sometimes contrasting effects according to its location, type of injury or site of damage. Strong evidence indicates that galectin-3 participates in the pathogenesis of diabetic complications via its receptor function for advanced glycation end-products (AGEs) and advanced lipoxidation end-products (ALEs). AGEs/ALEs are produced to an increased extent in target organs of complications, such as kidney and vessels; here, lack of galectin-3 impairs their removal, leading to accelerated damage. In contrast, in the liver, AGE/ALE tissue content and injury are decreased, because lack of galectin-3 results in reduced uptake and tissue accumulation of these by-products. Some of these effects can be explained by changes in the expression of receptor for AGEs (RAGE), associated with galectin-3 deletion and consequent changes in AGE/ALE tissue levels. Furthermore, galectin-3 might exert AGE/ALE- and RAGE-independent effects, favoring resolution of inflammation and modulating fibrogenesis and ectopic osteogenesis. These effects are mediated by intracellular and extracellular galectin-3, the latter via interaction with N-glycans at the cell surface to form lattice structures. Recently, galectin-3 has been implicated in the development of metabolic disorders because it favors glucose homeostasis and prevents the deleterious activation of adaptive and innate immune response to obesogenic/diabetogenic stimuli. In conclusion, galectin-3 is an emerging all-out player in metabolic disorders and their complications that deserves further investigation as the potential target of therapeutic intervention.

The purinergic 2X7 receptor participates in renal inflammation and injury induced by high-fat diet: possible role of NLRP3 inflammasome activation.

Renal disease associated with type 2 diabetes and the metabolic syndrome is characterized by a distinct inflammatory phenotype. The purinergic 2X7 receptor (P2X7 R) and the nucleotide-binding and oligomerization domain-like receptor containing a pyrin domain 3 (NLRP3) inflammasome have been separately shown to play a role in two models of non-metabolic chronic kidney disease. Moreover, the NLRP3 inflammasome has been implicated in chronic low-grade sterile inflammation characterizing metabolic disorders, though the mechanism(s) involved in inflammasome activation under these conditions are still unknown. We investigated the role of P2X7 R (through activation of the NLRP3 inflammasome) in renal inflammation and injury induced by a high-fat diet, an established model of the metabolic syndrome. On a high-fat diet, mice lacking P2X7 R developed attenuated renal functional and structural alterations as well as reduced inflammation, fibrosis, and oxidative/carbonyl stress, as compared with wild-type animals, in the absence of significant differences in metabolic parameters. This was associated with blunted up-regulation of the NLRP3 inflammasome components NLRP3, apoptosis-associated speck-like protein containing a caspase recruitment domain (ASC), pro-caspase 1, pro-interleukin (IL)-1ß, and pro-IL-18, as well as reduced inflammasome activation, as evidenced by decreased formation of mature caspase 1, whereas mature IL-1ß and IL-18 were not detected. Up-regulated expression of NLRP3 and pro-caspase 1, post-translational processing of pro-caspase-1, and release of IL-18 in response to lipopolysaccharide + 2'(3')-O-(4-benzoylbenzoyl)ATP were attenuated by P2X7 R silencing in cultured mouse podocytes. Protein and mRNA expression of P2X7 R, NLRP3, and ASC were also increased in kidneys from subjects with type 2 diabetes and the metabolic syndrome, showing histologically documented renal disease. These data provide evidence of a major role for the purinergic system, at least in part through activation of the NLRP3 inflammasome, in the process driving 'metabolic' renal inflammation and injury and identify P2X7 R and NLRP3 as novel therapeutic targets.

Galectin-3 in diabetic patients.

Galectin-3 is a versatile molecule which exerts several and sometimes opposite functions in various pathophysiological processes. Recently, galectin-3 has gained attention as a powerful predictor of heart failure and mortality, thus becoming a useful prognostic marker in clinical practice. Moreover, though not specifically investigated in diabetic cohorts, plasma levels of galectin-3 correlated with the prevalence of diabetes and related metabolic conditions, thus suggesting that pharmacological blockade of this lectin might be successful for treating heart failure especially in subjects suffering from these disorders. Indeed, galectin-3 is considered not only as a marker of heart failure, but also as a mediator of the disease, due to its pro-fibrotic action, though evidence comes mainly from studies in galectin-3 deficient mice. However, these studies have provided contrasting results, with either attenuation or acceleration of organ fibrosis and inflammation, depending on the experimental setting and particularly on the levels of advanced glycation endproducts (AGEs)/advanced lipoxidation endproducts (ALEs), of which galectin-3 is a scavenging receptor. In fact, under conditions of increased AGE/ALE levels, galectin-3 ablation was associated with tissue-specific outcomes, reflecting the AGE/ALE-receptor function of this lectin. Conversely, in experimental models of acute inflammation and fibrosis, galectin-3 deficiency resulted in attenuation of tissue injury. There is a need for prospective studies in diabetic patients specifically investigating the relation of galectin-3 levels with complications and for further animal studies in order to establish the effective role of this lectin in organ damage before considering its pharmacological blockade in the clinical setting.

Impaired Remodeling of White Adipose Tissue in Obesity and Aging: From Defective Adipogenesis to Adipose Organ Dysfunction.

The adipose organ adapts and responds to internal and environmental stimuli by remodeling both its cellular and extracellular components. Under conditions of energy surplus, the subcutaneous white adipose tissue (WAT) is capable of expanding through the enlargement of existing adipocytes (hypertrophy), followed by de novo adipogenesis (hyperplasia), which is impaired in hypertrophic obesity. However, an impaired hyperplastic response may result from various defects in adipogenesis, leading to different WAT features and metabolic consequences, as discussed here by reviewing the results of the studies in animal models with either overexpression or knockdown of the main molecular regulators of the two steps of the adipogenesis process. Moreover, impaired WAT remodeling with aging has been associated with various age-related conditions and reduced lifespan expectancy. Here, we delve into the latest advancements in comprehending the molecular and cellular processes underlying age-related changes in WAT function, their involvement in common aging pathologies, and their potential as therapeutic targets to influence both the health of elderly people and longevity. Overall, this review aims to encourage research on the mechanisms of WAT maladaptation common to conditions of both excessive and insufficient fat tissue. The goal is to devise adipocyte-targeted therapies that are effective against both obesity- and age-related disorders.

Effect of sustained decreases in sedentary time and increases in physical activity on liver enzymes and indices in type 2 diabetes.

Background: Current guidelines for nonalcoholic fatty liver disease (NAFLD) recommend high volumes and/or intensities of physical activity (PA), the achievement of which generally requires participation in supervised exercise training programs that however are difficult to implement in routine clinical practice. Conversely, counselling interventions may be more suitable, but result in only modest increases in moderate-to-vigorous-intensity PA (MVPA). This study assessed whether a counseling intervention for increasing PA and decreasing sedentary time (SED-time) is effective in improving NAFLD markers in people with type 2 diabetes. Methods: Three-hundred physically inactive and sedentary patients were randomized 1:1 to receive one-month theoretical and practical counseling once-a-year (intervention group) or standard care (control group) for 3 years. Aspartate aminotransferase (AST), alanine aminotransferase (ALT), and γ-glutamyltranspeptidase (γGT) levels were measured and fatty liver index (FLI), hepatic steatosis index (HSI), and visceral adiposity index (VAI) were calculated. Total PA volume, light-intensity PA (LPA), moderate-to-vigorous-intensity PA (MVPA), and SED-time were objectively measured by an accelerometer. Results: Throughout the 3-year period, NAFLD markers did not change in the control group, whereas ALT, γGT, FLI, and HSI decreased in the intervention group, with significant between-group differences, despite modest MVPA increases, which however were associated with larger decrements in SED-time and reciprocal increments in LPA. Mean changes in NAFLD markers varied according to quartiles of (and correlated with) changes in MVPA (all markers) and SED-time, LPA, and PA volume (ALT, γGT, and HSI). Mean changes in MVPA or PA volume were independent predictors of changes in NAFLD markers. When included in the models, change in cardiorespiratory fitness and lower body muscle strength were independently associated with some NAFLD markers. Conclusion: A behavior change involving all domains of PA lifestyle, even if insufficient to achieve the recommended MVPA target, may provide beneficial effects on NAFLD markers in people with type 2 diabetes.

The "sweet" path to cancer: focus on cellular glucose metabolism.

The hypoxia-inducible factor-1α (HIF-1α), a key player in the adaptive regulation of energy metabolism, and the M2 isoform of the glycolytic enzyme pyruvate kinase (PKM2), a critical regulator of glucose consumption, are the main drivers of the metabolic rewiring in cancer cells. The use of glycolysis rather than oxidative phosphorylation, even in the presence of oxygen (i.e., Warburg effect or aerobic glycolysis), is a major metabolic hallmark of cancer. Aerobic glycolysis is also important for the immune system, which is involved in both metabolic disorders development and tumorigenesis. More recently, metabolic changes resembling the Warburg effect have been described in diabetes mellitus (DM). Scientists from different disciplines are looking for ways to interfere with these cellular metabolic rearrangements and reverse the pathological processes underlying their disease of interest. As cancer is overtaking cardiovascular disease as the leading cause of excess death in DM, and biological links between DM and cancer are incompletely understood, cellular glucose metabolism may be a promising field to explore in search of connections between cardiometabolic and cancer diseases. In this mini-review, we present the state-of-the-art on the role of the Warburg effect, HIF-1α, and PKM2 in cancer, inflammation, and DM to encourage multidisciplinary research to advance fundamental understanding in biology and pathways implicated in the link between DM and cancer.

Mutual Regulation between Redox and Hypoxia-Inducible Factors in Cardiovascular and Renal Complications of Diabetes.

Oxidative stress and hypoxia-inducible factors (HIFs) have been implicated in the pathogenesis of diabetic cardiovascular and renal diseases. Reactive oxygen species (ROS) mediate physiological and pathophysiological processes, being involved in the modulation of cell signaling, differentiation, and survival, but also in cyto- and genotoxic damage. As master regulators of glycolytic metabolism and oxygen homeostasis, HIFs have been largely studied for their role in cell survival in hypoxic conditions. However, in addition to hypoxia, other stimuli can regulate HIFs stability and transcriptional activity, even in normoxic conditions. Among these, a regulatory role of ROS and their byproducts on HIFs, particularly the HIF-1α isoform, has received growing attention in recent years. On the other hand, HIF-1α and HIF-2α exert mutually antagonistic effects on oxidative damage. In diabetes, redox-mediated HIF-1α deregulation contributes to the onset and progression of cardiovascular and renal complications, and recent findings suggest that deranged HIF signaling induced by hyperglycemia and other cellular stressors associated with metabolic disorders may cause mitochondrial dysfunction, oxidative stress, and inflammation. Understanding the mechanisms of mutual regulation between HIFs and redox factors and the specific contribution of the two main isoforms of HIF-α is fundamental to identify new therapeutic targets for vascular complications of diabetes.

Food-Related Carbonyl Stress in Cardiometabolic and Cancer Risk Linked to Unhealthy Modern Diet.

Carbonyl stress is a condition characterized by an increase in the steady-state levels of reactive carbonyl species (RCS) that leads to accumulation of their irreversible covalent adducts with biological molecules. RCS are generated by the oxidative cleavage and cellular metabolism of lipids and sugars. In addition to causing damage directly, the RCS adducts, advanced glycation end-products (AGEs) and advanced lipoxidation end-products (ALEs), cause additional harm by eliciting chronic inflammation through receptor-mediated mechanisms. Hyperglycemia- and dyslipidemia-induced carbonyl stress plays a role in diabetic cardiovascular complications and diabetes-related cancer risk. Moreover, the increased dietary exposure to AGEs/ALEs could mediate the impact of the modern, highly processed diet on cardiometabolic and cancer risk. Finally, the transient carbonyl stress resulting from supraphysiological postprandial spikes in blood glucose and lipid levels may play a role in acute proinflammatory and proatherogenic changes occurring after a calorie dense meal. These findings underline the potential importance of carbonyl stress as a mediator of the cardiometabolic and cancer risk linked to today's unhealthy diet. In this review, current knowledge in this field is discussed along with future research courses to offer new insights and open new avenues for therapeutic interventions to prevent diet-associated cardiometabolic disorders and cancer.

Relationships of Changes in Physical Activity and Sedentary Behavior With Changes in Physical Fitness and Cardiometabolic Risk Profile in Individuals With Type 2 Diabetes: The Italian Diabetes and Exercise Study 2 (IDES_2).

OBJECTIVE: In the Italian Diabetes and Exercise Study_2 (IDES_2), behavioral counseling promoted a sustained increase in physical activity (PA) volume (+3.3 MET h ⋅ week-1), moderate- to vigorous-intensity PA (MVPA) (+6.4 min ⋅ day-1), and light-intensity PA (LPA) (+0.8 h ⋅ day-1) and decrease in sedentary time (SED-time) (-0.8 h ⋅ day-1). Here, we investigated the relationships of changes in PA/SED-time with changes in physical fitness and cardiometabolic risk profile in individuals with type 2 diabetes. RESEARCH DESIGN AND METHODS: In this 3-year randomized clinical trial, 300 physically inactive and sedentary patients were randomized 1:1 to receive 1-month theoretical and practical counseling once a year or standard care. Changes in physical fitness and cardiovascular risk factors/scores according to quartiles of accelerometer-measured changes in PA/SED-time were assessed, together with univariate and multivariable associations between these parameters, in the whole cohort and by study arm. RESULTS: Physical fitness increased and HbA1c and coronary heart disease 10-year risk scores decreased with quartiles of MVPA and SED-time change. In quartile IV of MVPA increase and SED-time decrease, cardiorespiratory fitness increased by 5.23 and 4.49 mL ⋅ min-1 ⋅ kg-1 and HbA1c decreased by 0.73 and 0.85%, respectively. Univariate correlations confirmed these relationships, and mean changes in both MPVA and SED-time predicted changes in physical fitness and cardiovascular risk factors/scores independently of one another and of other confounders. Similar findings were observed with LPA and PA volume and in each group separately. CONCLUSIONS: Even modest increments in MVPA may have a clinically meaningful impact, and reallocating SED-time to LPA may also contribute to improved outcomes, possibly by increasing total energy expenditure.

Galectin-3 ablation protects mice from diet-induced NASH: a major scavenging role for galectin-3 in liver.

BACKGROUND & AIMS: Excess fatty acid oxidation and generation of reactive carbonyls with formation of advanced lipoxidation endproducts (ALEs) is involved in nonalcoholic steatohepatitis (NASH) by triggering inflammation, hepatocyte injury, and fibrosis. This study aimed at verifying the hypothesis that ablation of the ALE-receptor galectin-3 prevents experimental NASH by reducing receptor-mediated ALE clearance and downstream events. METHODS: Galectin-3-deficient (Lgals3(-/-)) and wild type (Lgals3(+/+)) mice received an atherogenic diet or standard chow for 8 months. Liver tissue was analyzed for morphology, inflammation, cell and matrix turnover, lipid metabolism, ALEs, and ALE-receptors. RESULTS: Steatosis was significantly less pronounced in Lgals3(-/-) than Lgals3(+/+) animals on atherogenic diet. NASH, invariably detected in Lgals3(+/+) mice, was observed, to a lower extent, only in 3/8 Lgals3(-/-) mice, showing less inflammatory, degenerative, and fibrotic phenomena than Lgals3(+/+) mice. This was associated with higher circulating ALE levels and lower tissue ALE accumulation and expression of other ALE-receptors. Up-regulation of hepatic fatty acid synthesis and oxidation, inflammatory cell infiltration, pro-inflammatory cytokines, endoplasmic reticulum stress, hepatocyte apoptosis, myofibroblast transdifferentiation, and impaired Akt phosphorylation were also significantly attenuated in Lgals3(-/-) animals. Galectin-3 silencing in liver endothelial cells resulted in reduced N(ε)-carboxymethyllysine-modified albumin uptake and ALE-receptor expression. CONCLUSIONS: Galectin-3 ablation protects from diet-induced NASH by decreasing hepatic ALE accumulation, with attenuation of inflammation, hepatocyte injury, and fibrosis. It also reduced up-regulation of lipid synthesis and oxidation causing less fat deposition, oxidative stress, and possibly insulin resistance. These data suggest that galectin-3 is a major receptor involved in ALE uptake by the liver.

Normalizing HIF-1α Signaling Improves Cellular Glucose Metabolism and Blocks the Pathological Pathways of Hyperglycemic Damage.

Intracellular metabolism of excess glucose induces mitochondrial dysfunction and diversion of glycolytic intermediates into branch pathways, leading to cell injury and inflammation. Hyperglycemia-driven overproduction of mitochondrial superoxide was thought to be the initiator of these biochemical changes, but accumulating evidence indicates that mitochondrial superoxide generation is dispensable for diabetic complications development. Here we tested the hypothesis that hypoxia inducible factor (HIF)-1α and related bioenergetic changes (Warburg effect) play an initiating role in glucotoxicity. By using human endothelial cells and macrophages, we demonstrate that high glucose (HG) induces HIF-1α activity and a switch from oxidative metabolism to glycolysis and its principal branches. HIF1-α silencing, the carbonyl-trapping and anti-glycating agent ʟ-carnosine, and the glyoxalase-1 inducer trans-resveratrol reversed HG-induced bioenergetics/biochemical changes and endothelial-monocyte cell inflammation, pointing to methylglyoxal (MGO) as the non-hypoxic stimulus for HIF1-α induction. Consistently, MGO mimicked the effects of HG on HIF-1α induction and was able to induce a switch from oxidative metabolism to glycolysis. Mechanistically, methylglyoxal causes HIF1-α stabilization by inhibiting prolyl 4-hydroxylase domain 2 enzyme activity through post-translational glycation. These findings introduce a paradigm shift in the pathogenesis and prevention of diabetic complications by identifying HIF-1α as essential mediator of glucotoxicity, targetable with carbonyl-trapping agents and glyoxalase-1 inducers.

Diabetic Complications and Oxidative Stress: A 20-Year Voyage Back in Time and Back to the Future.

Twenty years have passed since Brownlee and colleagues proposed a single unifying mechanism for diabetic complications, introducing a turning point in this field of research. For the first time, reactive oxygen species (ROS) were identified as the causal link between hyperglycemia and four seemingly independent pathways that are involved in the pathogenesis of diabetes-associated vascular disease. Before and after this milestone in diabetes research, hundreds of articles describe a role for ROS, but the failure of clinical trials to demonstrate antioxidant benefits and some recent experimental studies showing that ROS are dispensable for the pathogenesis of diabetic complications call for time to reflect. This twenty-year journey focuses on the most relevant literature regarding the main sources of ROS generation in diabetes and their role in the pathogenesis of cell dysfunction and diabetic complications. To identify future research directions, this review discusses the evidence in favor and against oxidative stress as an initial event in the cellular biochemical abnormalities induced by hyperglycemia. It also explores possible alternative mechanisms, including carbonyl stress and the Warburg effect, linking glucose and lipid excess, mitochondrial dysfunction, and the activation of alternative pathways of glucose metabolism leading to vascular cell injury and inflammation.

Diabetes and Pancreatic Cancer-A Dangerous Liaison Relying on Carbonyl Stress.

Both type 2 (T2DM) and type 1 (T1DM) diabetes mellitus confer an increased risk of pancreatic cancer in humans. The magnitude and temporal trajectory of the risk conferred by the two forms of diabetes are similar, suggesting a common mechanism. Carbonyl stress is a hallmark of hyperglycemia and dyslipidemia, which accompanies T2DM, prediabetes, and obesity. Accumulating evidence demonstrates that diabetes promotes pancreatic ductal adenocarcinoma (PDAC) in experimental models of T2DM, a finding recently confirmed in a T1DM model. The carbonyl stress markers advanced glycation end-products (AGEs), the levels of which are increased in diabetes, were shown to markedly accelerate tumor development in a mouse model of Kras-driven PDAC. Consistently, inhibition of AGE formation by trapping their carbonyl precursors (i.e., reactive carbonyl species, RCS) prevented the PDAC-promoting effect of diabetes. Considering the growing attention on carbonyl stress in the onset and progression of several cancers, including breast, lung and colorectal cancer, this review discusses the mechanisms by which glucose and lipid imbalances induce a status of carbonyl stress, the oncogenic pathways activated by AGEs and their precursors RCS, and the potential use of carbonyl-scavenging agents and AGE inhibitors in PDAC prevention and treatment, particularly in high-risk diabetic individuals.