Glucose intake induces an increase in activator protein 1 and early growth response 1 binding activities, in the expression of tissue factor and matrix metalloproteinase in mononuclear cells, and in plasma tissue factor and matrix metalloproteinase concentrations

Early divergent responses to virulent and attenuated vaccine isolates of Flavobacterium covae sp. nov. In channel catfish, Ictalurus punctatus

Columnaris disease continues to inflict substantial losses among freshwater cultured species since its first description one hundred years ago. The experimental and anecdotal evidence suggests an expanded range and rising virulence of columnaris worldwide due to the warming global climate. The channel catfish (Ictalurus punctatus) are particularly vulnerable to columnaris. A recently developed live attenuated vaccine (17-23) for Flavobacterium columnare (now Flavobacterium covae sp. nov.) demonstrated superior protection for vaccinated catfish against genetically diverse columnaris isolates. In this study, we aimed to elucidate the molecular mechanisms and patterns of immune evasion and host manipulation linked to virulence by comparing gene expression changes in the host after the challenge with a virulent (BGSF-27) or live attenuated F. covae sp. nov. vaccine (17-23). Thirty-day-old fry were accordingly challenged with either virulent or vaccine isolates. Gill tissues were collected at 0 h (control), 1 h, and 2 h post-infection, which are two critical time points in early host-pathogen interactions. Transcriptome profiling of the gill tissues revealed a larger number (518) of differentially expressed genes (DEGs) in vaccine-exposed fish than those exposed to the virulent pathogen (321). Pathway analyses suggested potent suppression of early host immune responses by the virulent isolate through a higher expression of nuclear receptor corepressors (NCoR) responsible for antagonizing macrophage and T-cell signaling. Conversely, in vaccinated fry, we observed induction of Ca2+/calmodulin-dependent protein kinase II (CAMKII), responsible for clearing NCoR, and commensurate up-regulation of transcription factor AP-1 subunits, c-Fos, and c-Jun. As in mammalian systems, AP-1 expression was connected with a broad immune activation in vaccinated fry, including induction of CC chemokines, proteinases, iNOS, and IL-12b. Relatedly, divergent expression patterns of Src tyrosine kinase Lck, CD44, and CD28 indicated a delay or suppression of T-cell adhesion and activation in fry exposed to the virulent isolate. Broader implications of these findings will be discussed. The transcriptomic differences between virulent and attenuated bacteria may offer insights into how the host responds to the vaccination or infection and provide valuable knowledge to understand the early immune mechanisms of columnaris disease in aquaculture.

A review of stress-induced hyperglycaemia in the context of acute ischaemic stroke: Definition, underlying mechanisms, and the status of insulin therapy

The transient elevation of blood glucose produced following acute ischaemic stroke (AIS) has been described as stress-induced hyperglycaemia (SIH). SIH is common even in patients with AIS who have no previous diagnosis of diabetes mellitus. Elevated blood glucose levels during admission and hospitalization are strongly associated with enlarged infarct size and adverse prognosis in AIS patients. However, insulin-intensive glucose control therapy defined by admission blood glucose for SIH has not achieved the desired results, and new treatment ideas are urgently required. First, we explore the various definitions of SIH in the context of AIS and their predictive value in adverse outcomes. Then, we briefly discuss the mechanisms by which SIH arises, describing the dual effects of elevated glucose levels on the central nervous system. Finally, although preclinical studies support lowering blood glucose levels using insulin, the clinical outcomes of intensive glucose control are not promising. We discuss the reasons for this phenomenon.

Advancing in the understanding of coagulopathy during hemorrhagic shock: From the triad to the deadly pentad

The deadly triad concept represented a dogma in the definition of poor outcomes and death associated with major bleeding in trauma. This model of end-stage disease was then rapidly transferred to other major bleeding scenarios. However, and notwithstanding the fact that it represented a severe scenario, the original triad fails to establish a sequence, which would be relevant when defining the objectives during the initial treatment of severe bleeding.  It has been recently suggested that hypoxia and hyperglycemia should be included as isolated, determining factors in this model. Likewise, the model admits only one scenario where all the conditions shall co-exist, knowing that each one of them contributes with a different risk burden. Based on a structured review, we submit a pentad model that includes a natural pattern of events occurring with hypoxemia as the main trigger for the development of hypocalcemia, hyperglycemia, acidosis and hypothermia, as hallmarks of multiple system impairment. This severity model of major bleeding ends with coagulopathy as a result of the failure to resolve the rest of the previous components.

Evolutionarily conserved transcription factors as regulators of longevity and targets for geroprotection

Aging is the single largest risk factor for many debilitating conditions, including heart diseases, stroke, cancer, diabetes, and neurodegenerative disorders. While far from understood in its full complexity, it is scientifically well-established that aging is influenced by genetic and environmental factors, and can be modulated by various interventions. One of aging's early hallmarks are aberrations in transcriptional networks, controlling for example metabolic homeostasis or the response to stress. Evidence in different model organisms abounds that a number of evolutionarily conserved transcription factors, which control such networks, can affect lifespan and healthspan across species. These transcription factors thus potentially represent conserved regulators of longevity and are emerging as important targets in the challenging quest to develop treatments to mitigate age-related diseases, and possibly even to slow aging itself. This review provides an overview of evolutionarily conserved transcription factors that impact longevity or age-related diseases in at least one multicellular model organism (nematodes, flies, or mice), and/or are tentatively linked to human aging. Discussed is the general evidence for transcriptional regulation of aging and disease, followed by a more detailed look at selected transcription factor families, the common metabolic pathways involved, and the targeting of transcription factors as a strategy for geroprotective interventions.

Diabetes and Ischemic Stroke: An Old and New Relationship an Overview of the Close Interaction between These Diseases

Diabetes mellitus is a comprehensive expression to identify a condition of chronic hyperglycemia whose causes derive from different metabolic disorders characterized by altered insulin secretion or faulty insulin effect on its targets or often both mechanisms. Diabetes and atherosclerosis are, from the point of view of cardio- and cerebrovascular risk, two complementary diseases. Beyond shared aspects such as inflammation and oxidative stress, there are multiple molecular mechanisms by which they feed off each other: chronic hyperglycemia and advanced glycosylation end-products (AGE) promote ‘accelerated atherosclerosis’ through the induction of endothelial damage and cellular dysfunction. These diseases impact the vascular system and, therefore, the risk of developing cardio- and cerebrovascular events is now evident, but the observation of this significant correlation has its roots in past decades. Cerebrovascular complications make diabetic patients 2–6 times more susceptible to a stroke event and this risk is magnified in younger individuals and in patients with hypertension and complications in other vascular beds. In addition, when patients with diabetes and hyperglycemia experience an acute ischemic stroke, they are more likely to die or be severely disabled and less likely to benefit from the one FDA-approved therapy, intravenous tissue plasminogen activator. Experimental stroke models have revealed that chronic hyperglycemia leads to deficits in cerebrovascular structure and function that may explain some of the clinical observations. Increased edema, neovascularization, and protease expression as well as altered vascular reactivity and tone may be involved and point to potential therapeutic targets. Further study is needed to fully understand this complex disease state and the breadth of its manifestation in the cerebrovasculature.

Time in blood glucose range 70 to 180 mg/dL and survival rate in critically ill patients: A retrospective cohort study

Background

While time in targeted blood glucose range (TIR) 70–140 mg/dL is a known factor associated with mortality in critically ill patients, it remains unclear whether TIR is associated with 28-day mortality under the glycemic control with a less tight target glucose range of 70–180 mg/dL. We aimed to examine whether TIR 70–180 mg/dL was associated with 28-day mortality.

Methods

This is a retrospective cohort study using data from a tertiary care center in Japan collected from January 2016 through October 2019. We included adult patients (aged ≥20 years) admitted to the ICU. We excluded patients 1) with diabetic ketoacidosis patients, 2) discharged within 48 hours, 3) with repeated ICU admissions. We calculated TIR 70–180 mg/dL using the measured blood glucose values (≥3 times per day). The primary outcome was 28-day mortality. We examined the association between TIR and 28-day mortality using a logistic regression and Cox proportional hazard models with a stratification by glycosylated hemoglobin (HbA1c) level of 6.5%. Additionally, we repeated the analyses using the TIR category to assess the optimal TIR. For the sensitivity analysis, we repeated the primary analysis using TIR during the first three days from ICU admission.

Results

Of 1,230 patients, the median age was 72 years, 65% were male, and 250 patients (20%) had HbA1c ≥6.5% on admission. In patients with HbA1c <6.5%, TIR <80% was associated with an increased risk of 28-day mortality, with an adjusted odds ratio (OR) of 1.88 (95%CI: 1.36–2.61). Likewise, when using 10% incremental TIR as a categorical variable, lower TIR was associated with a worse 28-day mortality compared with TIR ≥90% (e.g., adjusted OR of TIR <60%, 3.62 [95%CI 2.36–5.53]). Similar associations were found in the analyses using Cox proportional hazards model and using TIR during the first three days. By contrast, in patients with HbA1c ≥6.5%, there was no consistent association of TIR with 28-day mortality.

Conclusions

We found that lower TIR 70–180 mg/dL was associated with a higher 28-day mortality in critically ill patients with HbA1c <6.5%, whereas there was no consistent association in patients with HbA1c ≥6.5%.

Antioxidant and Anti-Inflammatory Potential of Polyphenols Contained in Mediterranean Diet in Obesity: Molecular Mechanisms

Nutrition transition can be defined as shifts in food habits, and it is characterized by high-fat (chiefly saturated animal fat), hypercaloric and salty food consumption at the expense of dietary fibers, minerals and vitamins. Western dietary patterns serve as a model for studying the impact of nutrition transition on civilization diseases, such as obesity, which is commonly associated with oxidative stress and inflammation. In fact, reactive oxygen species (ROS) overproduction can be associated with nuclear factor-κB (NF-κB)-mediated inflammation in obesity. NF-κB regulates gene expression of several oxidant-responsive adipokines including tumor necrosis factor-α (TNF-α). Moreover, AMP-activated protein kinase (AMPK), which plays a pivotal role in energy homeostasis and in modulation of metabolic inflammation, can be downregulated by IκB kinase (IKK)-dependent TNF-α activation. On the other hand, adherence to a Mediterranean-style diet is highly encouraged because of its healthy dietary pattern, which includes antioxidant nutraceuticals such as polyphenols. Indeed, hydroxycinnamic derivatives, quercetin, resveratrol, oleuropein and hydroxytyrosol, which are well known for their antioxidant and anti-inflammatory activities, exert anti-obesity proprieties. In this review, we highlight the impact of the most common polyphenols from Mediterranean foods on molecular mechanisms that mediate obesity-related oxidative stress and inflammation. Hence, we discuss the effects of these polyphenols on a number of signaling pathways. We note that Mediterranean diet (MedDiet) dietary polyphenols can de-regulate nicotinamide adenine dinucleotide phosphate (NADPH) oxidase (NOX) and NF-κB-mediated oxidative stress, and metabolic inflammation. MedDiet polyphenols are also effective in upregulating downstream effectors of several proteins, chiefly AMPK.

Stress-Induced Hyperglycaemia in Non-Diabetic Patients with Acute Coronary Syndrome: From Molecular Mechanisms to New Therapeutic Perspectives

Stress-induced hyperglycaemia (SIH) at hospital admission for acute coronary syndrome is associated with poor outcome, especially in patients without known diabetes. Nevertheless, insulin treatment in these subjects was not correlated with the reduction of mortality. This is likely due to the fact that SIH in the context of an acute coronary syndrome, compared to that in known diabetes, represents an epiphenomenon of other pathological conditions, such as adrenergic and renin-angiotensin system over-activity, hyperglucagonaemia, increase of circulating free fatty acids and pancreatic beta-cell dysfunction, which are not completely reversed by insulin therapy and so worsen the prognosis. Thus, SIH may be considered not only as a biomarker of organ damage, but also as an indicator of a more complex therapeutic strategy in these subjects. The aim of this review is to analyse the molecular mechanisms by which SIH may favour a worse prognosis in non-diabetic patients with acute coronary syndrome and identify new therapeutic strategies, in addition to insulin therapy, for a more appropriate treatment and improved outcomes.

Natural Flavones and Flavonols: Relationships among Antioxidant Activity, Glycation, and Metalloproteinase Inhibition

Reactive oxygen and nitrogen species as well as advanced glycation endproducts (AGEs) and metalloproteinases (MMPs) play a key role in the development and progression of degenerative processes of body tissues, including skin. Natural antioxidant flavonoids could be beneficial in inhibiting AGEs’ formation and MMPs’ expression. In this study, the antioxidant activity of flavones (luteolin, apigenin, and chrysin) and flavonols (mirycetin, quercetin, and kaempferol) was compared with their inhibitory effects on both metalloproteinases’ (MMP-1, MMP-2, MMP-9, MMP-13) and AGEs’ formation. Comparisons were performed taking into account the hydroxyl group arrangement and the physico-chemical parameters the binding dissociation enthalpy (BDE), ionization potential (IP), partition coefficient (log P), and topological polar surface area (TPSA). Increasing the number of hydroxyl groups led to a proportional enhancement of antioxidant activity while an inverse relationship was observed plotting the antioxidant activity vs. BDE and IP values. All flavonoids acted as AGEs, MMP-1, and MMP-13 inhibitors, but they were less effective against MMP-2 and MMP-9. The inhibition of MMP-1 seemed to be related to the TPSA values while high TPSA and low log P values seemed important conditions for inhibiting MMP-13. Overall, our data suggest that an estimation of flavonoid activity could be anticipated based on their physico-chemical parameters.

Macronutrient-Mediated Inflammation and Oxidative Stress: Relevance to Insulin Resistance, Obesity, and Atherogenesis

CONTEXT

The intake of macronutrients as components of a Western dietary pattern leads to oxidative stress and inflammation.

EVIDENCE ACQUISITION

Data were largely retrieved from our previous and most recent work. PubMed and Google Scholar were searched for recent articles on the effect of macronutrients/dietary intake on inflammation, insulin resistance, obesity, and atherogenesis. The most relevant, high-quality articles were included in our review.

EVIDENCE SYNTHESIS

Our previous work has demonstrated the molecular mechanisms of macronutrient-mediated oxidative stress and inflammation. With the induction of inflammation, proinflammatory molecules potentially interfere with insulin signal transduction, thus causing insulin resistance. In addition, other molecules promote atherogenic inflammation. More recently, our work has also shown that certain foods are noninflammatory or anti-inflammatory and thus, do not interfere with insulin signaling. Finally, as obesity is induced by chronic excessive caloric intake, it is characterized by an increase in the expression of proinflammatory molecules, which are induced acutely by a Western diet. Caloric restriction, including fasting, is associated with a reduction in oxidative and inflammatory stress.

CONCLUSIONS

This review summarizes and attempts to provide an up-to-date profile of the molecular mechanisms involved in macronutrient-mediated oxidative/inflammatory stress and its potential consequences. An understanding of these underlying mechanisms is crucial for making appropriate dietary choices.

Serum gamma-glutamyltransferase and the overall survival of metastatic pancreatic cancer

Background

Accumulating evidence suggests that Gamma-glutamyltransferase (GGT) may be involved in cancer occurrence and progression. However, the prognostic role of serum GGT in pancreatic cancer (PC) survival lacks adequate evaluation. In this study, we aimed to analyze the association between serum GGT measured at diagnosis and overall survival (OS) in patients with metastatic PC.

Methods

We identified 320 patients with histopathologically confirmed metastatic pancreatic ductal adenocarcinoma (PDAC) diagnosed during 2015 and 2016 at a specialized cancer hospital in southwestern China. Univariate and multivariate Cox proportional-hazards models were used to determine associations between serum GGT and OS in metastatic PDAC.

Results

Controlled for possible confounding factors, serum GGT was significantly associated with OS: serum GGT > 48 U/L yielded a hazard ratio of 1.53 (95% CI: 1.19–1.97) for mortality risk. A significant dose-response association between serum GGT and OS was also observed. Subgroup analysis showed a possible interaction between GGT and blood glucose level.

Conclusion

Serum GGT could be a potential indicator of survival in metastatic PDAC patients. Underlying mechanisms for this association should be investigated.

Metabolic Cytokines at Fasting and During Macronutrient Challenges: Influence of Obesity, Female Androgen Excess and Sex

Scope: Cytokines have pleiotropic functions within the organism and their levels may be influenced by obesity, visceral adiposity and sex hormones. Diet composition may also affect their systemic concentrations during fasting and in the postprandial period. Hence, we studied the influence of sex steroids and obesity on the circulating levels of a panel of metabolic cytokines in the fasting state and after single macronutrient challenges. Methods: On alternate days we submitted 17 women with polycystic ovary syndrome (PCOS) (9 non-obese, 8 obese), 17 non-hyperandrogenic control women (9 non-obese, 8 obese) and 19 control men (10 non-obese, 9 obese) to isocaloric oral glucose, lipid and protein loads. Serum levels of omentin-1, vaspin, lipocalin-2, adipsin, PAI-1, chemerin, FGF-21 and FGF-23 were determined by Luminex multiplex technology. Results: During fasting, obese patients presented higher levels of PAI-1, chemerin and adipsin but decreased FGF-23 and omentin-1 compared with non-obese subjects. Vaspin showed sexual dimorphism with lower levels in men than women with PCOS and female controls. Following macronutrient ingestion, most metabolic cytokines presented a similar physiological response consisting of a decrease in circulating concentrations, which was inversely associated with the fasting levels of these molecules. Protein intake caused the major postprandial decrease whereas glucose did not significantly reduce PAI-1, FGF-23 and vaspin, and even increased FGF-21. Regardless of the macronutrient administered, vaspin levels showed a larger reduction in non-obese individuals while the decrease in PAI-1 was particularly noticeable in the obese subgroup. The postprandial reductions of omentin-1 and FGF-23 after glucose and protein loads were influenced by obesity. No major differences were found between patients with PCOS and male and female controls. Conclusions: Obesity, but not PCOS or sex, markedly influences metabolic cytokine levels at fasting and after macronutrient ingestion. The observed postprandial decrease in their circulating concentrations might represent a physiological compensatory mechanism against food-induced inflammation and oxidative stress. This mechanism is altered by obesity and is differently modulated by macronutrients, suggesting a larger contribution of glucose to stressful postprandial responses.

The relationship between pancreatic cancer and type 2 diabetes: cause and consequence

Pancreatic cancer (PC) is a devastating and lethal malignant disease and it is well known that there is a complex bidirectional relationship between PC and type 2 diabetes mellitus (T2DM). In order to more deeply summarize the relationship between them, this article summarizes the epidemiological data on the relationship between PC and T2DM in the past 5 years, and further explains the mechanism of interaction between them. Meanwhile, it also summed up the effects of drug therapy for T2DM on PC and the impact of T2DM on surgical resection of PC. Epidemiological studies clearly indicate that the risk of PC is increased in patients with T2DM. But increasing epidemiological data points out that PC also acts as a cause of T2DM and new-onset T2DM is sign and consequence of PC. Insulin resistance, hyperinsulinemia, hyperglycemia, and chronic inflammation are the mechanisms of T2DM-Associated PC. Metformin decreases the risk of PC, while insulin therapy increases the risk of PC. Besides, studies have shown that T2DM decreases the survival in patients with PC resection.

Assessment of PON1 activity and circulating TF levels in relation to BMI, testosterone, HOMA-IR, HDL-C, LDL-C, CHO, SOD activity and TAC in women with PCOS: An observational study

BACKGROUND

Polycystic Ovary Syndrome (PCOS) is the most common female endocrinopathy among premenopausal women associated with hyperandrogenism, obesity, dyslipidemia, insulin resistance and inflammation. Oxidative stress is an important component of cardio-metabolic risk seen in PCOS.

MATERIAL AND METHODS

A total of 95 women with PCOS and 95 healthy controls were included in this observational study. Serum PON1 activity and stress markers were measured by spectrophotometric methods. Circulating TF level was measured by ELISA.

RESULTS

We found decreased PON1 activity and increased TF levels in women with PCOS compared to healthy controls. Fasting insulin, HOMA-IR, testosterone, LDL-C, MDA, PC and SOD activity were significantly increased whereas FGIR, QUICKI, HDLC, CAT and TAC were significantly decreased in PCOS women than controls. We observed a positive association of PON1 activity with FGIR, QUICKI, HDL-C and TAC, and its negative association was observed with LH, testosterone, fasting insulin and HOMA-IR in PCOS women. We further observed a positive association of TF with waist, waist to hip ratio, BMI, glucose 1hr, cholesterol, LDL-C, SGPT, uric acid and SOD activity in PCOS women.

CONCLUSIONS

Decreased PON1 activity and raised circulating TF levels are respective indicators of pro-inflammatory and procoagulant status in PCOS women. The imbalanced oxidant/antioxidant status further supports the evidences that PCOS is an oxidant state. Further, the association of PON1 activity and TF levels with the clinical, laboratory findings and stress marker levels suggest that these factors taken together are involved in aggravating the pro-inflammatory status in PCOS women.

A paradoxical relationship between hemoglobin A1C and in-hospital mortality in intracerebral hemorrhage patients

Objectives

The relationship between prior glycemic status and outcomes in intracerebral hemorrhage (ICH) is not established. We hypothesized that higher hemoglobin (Hb) A1c is associated with worse outcomes in ICH.

Patients and methods

Using the GWTG-Stroke registry, data on patients with ICH between April 1, 2003 and September 30, 2015 were harvested. Patients were divided into four ordinal groups based on HbA1c values of <5.7%, 5.7-6.4%, 6.5-8.0% and >8.0%. Outcomes (mortality, modified Rankin Scale (mRS), home discharge and independent ambulatory status) were analyzed for patients overall and separately for patients with or without history of diabetes using multivariable regression models.

Results

Among 75,455 patients with ICH (with available HbA1c data), patients with lower HbA1c (<5.7%) had higher rates of in-hospital mortality in the entire cohort (15.5%; 3947/25473); as well as those with history of diabetes (19.0%; 542/2852). Among those without history of diabetes, both lower HbA1c (15.1%; 3405/22621) and higher HbA1c (>8.0%), (15.0%; 205/1364) were associated with higher in-hospital mortality. Lower HbA1c was also associated with higher mRS, less chance of going home, and lower likelihood of having independent ambulatory status in patients with prior history of diabetes.

Conclusions

Among patients with no reported history of diabetes, both very low and very high HbA1c were directly associated with higher in-hospital mortality. Only very low HbA1c was associated with higher mortality in known diabetic patients. Further studies are needed to better define the relationship between HbA1c and outcomes, for it may have important implications for care of ICH patients.

Effect of Permissive Underfeeding with Intensive Insulin Therapy on MCP-1, sICAM-1, and TF in Critically Ill Patients

Purpose: This study examined the effect of permissive underfeeding compared to target feeding and intensive insulin therapy (IIT) compared to conventional insulin therapy (CIT) on the inflammatory mediators monocyte chemoattractant protein 1 (MCP-1), soluble intercellular adhesion molecule 1 (sICAM-1), and tissue factor (TF) in critically ill patients. Methodology: This was a substudy of a 2 × 2 factorial design randomized controlled trial in which intensive care unit (ICU) patients were randomized into permissive underfeeding compared to target feeding groups and into IIT compared to CIT groups (ISRCTN96294863). In this substudy, we included 91 patients with almost equal numbers across randomization groups. Blood samples were collected at baseline and at days 3, 5, and 7 of an ICU stay. Linear mixed models were used to assess the differences in MCP-1, sICAM-1, and TF across randomization groups over time. Results: Baseline characteristics were balanced across randomization groups. Daily caloric intake was significantly higher in the target feeding than in the permissive underfeeding groups (P-value < 0.01), and the daily insulin dose was significantly higher in the IIT than in the CIT groups (P-value < 0.01). MCP-1, sICAM-1, and TF did not show any significant difference between the randomization groups, while there was a time effect for MCP-1. Baseline sequential organ failure assessment (SOFA) score and platelets had a significant effect on sICAM-1 (P-value < 0.01). For TF, there was a significant association with age (P-value < 0.01). Conclusions: Although it has been previously demonstrated that insulin inhibits MCP-1, sICAM-1 in critically ill patients, and TF in non-critically ill patients, our study demonstrated that IIT in critically ill patients did not affect these inflammatory mediators. Similarly, caloric intake had a negligible effect on the inflammatory mediators studied.

Acute glucose fluctuation impacts microglial activity, leading to inflammatory activation or self-degradation

Diabetes mellitus is associated with an increased risk of Alzheimer’s dementia and cognitive decline. The cause of neurodegeneration in chronic diabetic patients remains unclear. Changes in brain microglial activity due to glycemic fluctuations may be an etiological factor. Here, we examined the impact of acute ambient glucose fluctuations on BV-2 microglial activity. Biochemical parameters were assayed and showed that the shift from normal glucose (NG; 5.5 mM) to high glucose (HG; 25 mM) promoted cell growth and induced oxidative/inflammatory stress and microglial activation, as evidenced by increased MTT reduction, elevated pro-inflammatory factor secretion (i.e., TNF-α and oxygen free radicals), and upregulated expression of stress/inflammatory proteins (i.e., HSP70, HO-1, iNOS, and COX-2). Also, LPS-induced inflammation was enlarged by an NG-to-HG shift. In contrast, the HG-to-NG shift trapped microglia in a state of metabolic stress, which led to apoptosis and autophagy, as evidenced by decreased Bcl-2 and increased cleaved caspase-3, TUNEL staining, and LC3B-II expression. These stress episodes were primarily mediated through MAPKs, PI3K/Akt, and NF-κB cascades. Our study demonstrates that acute glucose fluctuation forms the stress that alters microglial activity (e.g., inflammatory activation or self-degradation), representing a novel pathogenic mechanism for the continued deterioration of neurological function in diabetic patients.

Utilizing Dietary Nutrient Ratios in Nutritional Research: Expanding the Concept of Nutrient Ratios to Macronutrients

We recently showed that using micronutrient ratios in nutritional research might provide more insights into how diet affects metabolism and health outcomes, based on the notion that nutrients, unlike drugs, are not consumed one at a time and do not target a single metabolic pathway. In this paper, we present a concept of macronutrient ratios, including intra- and inter-macronutrient ratios. Macronutrient intakes from food only, from the What We Eat in America website (summarized National Health and Nutrition Examination Survey data) were transposed into Microsoft Excel to generate ratios. Overall, the dietary ratios of macronutrients may be more revealing and useful in epidemiology and in basic nutritional research than focusing on individual protein, fat, and carbohydrate intakes. While macronutrient ratios may be applied to all types of nutritional research, nutritional epidemiology, and, ultimately, dietary guidelines, the methodology required has not been established yet. In the meantime, intra- and inter-macronutrient ratios may serve as a measure of individual and total macronutrient quality.

Differential Expression of Human N-Alpha-Acetyltransferase 40 (hNAA40), Nicotinamide Phosphoribosyltransferase (NAMPT) and Sirtuin-1 (SIRT-1) Pathway in Obesity and T2DM: Modulation by Metformin and Macronutrient Intake

BACKGROUND

Interactions between environmental factors, such as diet and lifestyle, and metabolic pathways are pivotal in understanding aging mechanisms. hNAA40, Nicotinamide phosphoribosyltransferase (NAMPT), and NAD-dependent protein deacetylase sirtuin-1 (SIRT-1) have been shown to exert important biological processes, including stress response and aging.

METHODS

hNAA40, NAMPT, and SIRT-1 mRNA expression in peripheral blood mononuclear cells (PBMC) were quantitated in 30 lean adult volunteers of normal weight, 30 obese, 20 drug-naïve obese Type 2 diabetes mellitus (T2DM), and 30 obese T2DM on Metformin. Similarly, hNAA40, NAMPT, and SIRT-1 expression in PBMC were quantitated in 36 normal healthy adults randomly assigned to three different groups (Glucose or Whey proteins or lipids; 300 kcal). Blood samples were obtained at 1, 2, and 3 hrs after the macronutrient intake.

RESULTS

There was an increase in hNAA40 and a decrease in NAMPT and SIRT-1 expression in PBMC from T2DM. Metformin treatment reverted hNAA40, NAMPT, and SIRT-1 expression levels to normal levels. Glucose intake resulted in a significant increase in expression of hNAA40 at 1 hr and decreased significantly at 3 hrs post intake. Lipid intake resulted in an increase in expression of hNAA40 at 2 hr post intake and returned to normal levels at 3 hrs. Neither glucose nor lipid intake resulted in a significant change in NAMPT or SIRT-1 expression. Whey proteins resulted in significantly lower expression of NAMPT at 3 hrs and did not alter the expression levels of SIRT-1 significantly.

CONCLUSION

hNAA40, NAMPT, and SIRT-1 pathway could play a role in the determination of the healthy life-span. Metformin modulates this pathway.

Urea and chronic kidney disease: the comeback of the century? (in uraemia research)

Urea, a marker of uraemic retention in chronic kidney disease (CKD) and of adequacy of intradialytic solute removal, has traditionally been considered to be biologically inert. However, a number of recent experimental data suggest that urea is toxic at concentrations representative for CKD. First of all, at least five studies indicate that urea itself induces molecular changes related to insulin resistance, free radical production, apoptosis and disruption of the protective intestinal barrier. Second, urea is at the origin of the generation of cyanate, ammonia and carbamylated compounds, which as such all have been linked to biological changes. Especially carbamylation has been held responsible for post-translational protein modifications that are involved in atherogenesis and other functional changes. In observational clinical studies, these carbamylated compounds were associated with cardiovascular and overall morbidity and mortality. These findings shed new light on the validity of Kt/Vurea as a marker of dialysis adequacy. Yet, also the views that the kinetics of urea are not representative of the kinetics of several other uraemic retention solutes, and that urea cannot be held responsible for all complex metabolic and clinical changes responsible for the uraemic syndrome, still remain valid. Future efforts to improve the outcome of patients with CKD might be directed at further improving removal of solutes implied in the uraemic syndrome, including but not restricted to urea, also taking into account the impact of the intestine and (residual) renal function on solute concentration.

Association between Increased Matrix Metalloproteinase-9 (MMP-9) Levels with Hyperglycaemia Incidence in Acute Ischemic Stroke Patients

BACKGROUND:

Hyperglycemia is common in acute stroke patients. Hyperglycemia can induce the production of reactive oxygen species, causing increased activity of matrix metalloproteinase-9 (MMP-9).

AIM:

This study aimed to determine an association between the increased levels of MMP-9 and the incidence of hyperglycemia in acute ischemic stroke patients.

METHODS:

This is a case-control study. Acute ischemic stroke patients admitted to the Stroke Unit of a reference hospital in Yogyakarta, Indonesia was divided into the hyperglycemic and non-hyperglycemic group. Demographic and clinical characteristics of each subject were recorded, and blood levels of MMP-9 were measured. Seventy-one patients were recruited, 40 subjects in the hyperglycemic group and 31 subjects in the non-hyperglycemic group.

RESULTS:

The median levels of blood MMP-9 level in the hyperglycemic and non-hyperglycemic group were 974.37 and 748.48 ng/mL, respectively, and the difference was statistically not significant (95% CI, 191.24-2849.53; p = 0.07). When the calculated cut-off point of 600.99 ng/mL was used, the proportion of patients with higher MMP-9 levels was significantly more in the hyperglycemic group compared with the ones in the non-hyperglycemic group (82.5% and 54.8%, respectively; OR = 3.88; p = 0.011).

CONCLUSION:

We concluded that the proportion of patients with MMP-9 level >600.99 ng/mL was significantly higher in acute ischemic stroke patients with hyperglycemia.

Natural antioxidant polyphenols on inflammation management: Anti-glycation activity vs metalloproteinases inhibition

The diet polyphenols are a secondary metabolites of plants able to act on inflammation process. Their anti-inflammatory activity is articulated through several mechanisms that are related to their antioxidative and radical scavengers properties. Our work is focused on a novel approach to inflammatory disease management, based on anti-glycative and matrix metalloproteinases (MMPs) inhibition effects, as a connected phenomena. To better understand these correlation, polyphenols Structure-Activity Relationship (SAR) studies were also reported. The antioxidant polyphenols inhibit the AGEs at different levels of the glycation process in the following ways: (1) prevention of Amadori adduct oxidation; (2) trapping reactive dycarbonyl compounds; (3) attenuation of receptor for AGEs (RAGE) expression. Moreover, several flavonoids with radical scavenging property showed also MMPs inhibition interact directly with MMPs or indirectly via radical scavengers and AGEs reduction. The essential polyphenols features involved in these mechanisms are C2-C3 double bond and number and position of hydroxyl, glycosyl and O-methyl groups. These factors induce a change in molecular planarity interfering with the hydrogen bond formation, electron delocalization and metal ion chelation. In particular, C2-C3 double bond improve the antioxidant and MMPs inhibition, while the hydroxylation, glycosylation and methylation induce a positive and negative correlation, respectively.

Effects of insulin on wound healing: A review of animal and human evidences

AIMS

Several studies have indicated that insulin that is used in reducing blood glucose is also affective on wound healing by various mechanisms. To understand the outcomes of insulin therapy on wound healing, a meta-analysis and systematic review was performed.

MAIN METHODS

The Cochrane library, PubMed, and Science Direct were searched for the literature published from January the 1st 1990 to September the 30th 2016. Twelve animals and nine clinical studies were included. A quantitative and qualitative review was performed on the clinical trials and the animal studies were comprehensively overviewed. Statistical analysis for development of granulation tissue, microvessel density, and time of healing was conducted in this systematic review.

KEY FINDINGS

The animal studies revealed that treatment with topical insulin lead to faster wound contraction and re-epithelialization. Meta-analysis of wound studies revealed that insulin therapy is significantly favored for growth of granulation tissue. Based on these findings, insulin enhanced development of granulation tissue on day 7 after treatment. The meta-analysis studies indicated significant reduction in time of healing in the patients treated with insulin. These studies also disclosed that the new vessels were observable from five days after injection in the treated group, compared to the control animals that developed significantly at later stage.

SIGNIFICANCE

Insulin is a low cost growth factor and can be considered as a therapeutic agent in wound healing. However, further studies are necessary to gain a better understanding of the role of insulin in wound healing.

Comparative effects of acute hypoglycemia and hyperglycemia on pro-atherothrombotic biomarkers and endothelial function in non-diabetic humans

BACKGROUND

The comparative effects of acute moderate hyperglycemia and hypoglycemia on in vivo endothelial function together with pro-inflammatory and pro-atherothrombotic responses in healthy individuals have not been determined.

METHODS

To investigate this question, 45 healthy subjects were compared during glucose clamp studies consisting of euinsulinemic hyperglycemia and hyperinsulinemic hyperglycemia (plasma glucose 11.1mmol/L, both with pancreatic clamps) and hyperinsulinemic euglycemia and hyperinsulinemic hypoglycemia (plasma glucose 5.1 and 2.9mmol/L, respectively). Two-dimensional Doppler ultrasound was used to determine brachial artery endothelial function.

RESULTS

Insulin levels during euinsulinemia hyperglycemia were 194±23 and (850±49-988±114) pmol/L during all hyperinsulinemic protocols. Responses of VCAM-1, ICAM-1, E-selectin, P-selectin, PAI-1, and IL-6 were increased (p<0.05-0.0001) during euinsulinemic hyperglycemia or hypoglycemia as compared to hyperinsulinemic euglycemia or hyperinsulinemic hyperglycemia. PAI-1 was increased (p<0.04) during hypoglycemia as compared to euinsulinemic hyperglycemia, and TNF-α responses were also increased during hypoglycemia as compared to hyperinsulinemic euglycemia or hyperinsulinemic hyperglycemia (p<0.05). In vivo endothelial function was similarly blunted by acute moderate hyperglycemia or hypoglycemia.

CONCLUSION

In summary, acute moderate hypoglycemia and euinsulinemic hyperglycemia can result in similar endothelial dysfunction and pro-atherothrombotic responses. Fibrinolytic balance was reduced by a greater extent by hypoglycemia as compared to moderate hyperglycemia. Acutely, hyperinsulinemia can prevent the acute pro-atherothrombotic and pro-inflammatory effects of moderate hyperglycemia but not hypoglycemia.

Comprehensive interpretation of hyperglycemia and hyperosmolality on the clinical outcomes among ischemic stroke patients

BACKGROUND

Hyperglycemia and hyperosmolality are associated with poor outcomes among acute ischemic stroke (AIS) patients.

OBJECTIVES

We evaluated the association between hyperglycemia and hyperosmolality, as a combination measure, with poor outcome among AIS patients.

METHODS

We conducted a retrospective study of AIS patients admitted to the study hospital emergency department between January and December 2014. Hyperglycemia was defined as serum glucose >144 mg/dL, and hyperosmolality was defined as a serum osmolality >295 mOsm/kg. After excluding hypoglycemia and hypoosmolality, the enrolled patients were classified into the following 4 subgroups: normoglycemia-normoosmolality, hyperglycemia-normoosmolality (HGNO), normoglycemia-hyperosmolality (NGHO), and hyperglycemia-normoosmolality (HGHO). The primary outcome was poor neurological status at 6 months, which was defined as a modified Rankin scale score ≥2.

RESULTS

Six hundred seven patients were included. The primary outcome was 336 (55.4%), and it was highest in the HGNO group (69.6%, 103/148), followed by the HGHO group (67.9%, 53/78), the NGHO group (57.3%, 43/75) and the normoglycemia-normoosmolality group (44.7%, 137/306). The multivariable logistic regression analysis revealed that HGNO and HGHO remained significant factors, with primary outcomes (adjusted odds ratio, 2.08; 95% confidence interval, 1.16-3.71) and 2.93 (1.45-5.91), respectively), whereas NGHO was not a significant factor. Cases of extremely high sodium levels were few in the NGHO and HGHO groups, whereas considerable cases of extremely high glucose level were observed in the HGHO group.

CONCLUSION

Hyperglycemia was associated with poor outcome, even after excluding the effect of hyperosmolality. However, hyperosmolality without hyperglycemia was not associated with poor outcome. An additive effect, likely reflecting severe hyperglycemia, was observed.

The association between blood glucose levels and matrix-metalloproteinase-9 in early severe sepsis and septic shock

Background

Hyperglycemia is a frequent and important metabolic derangement that accompanies severe sepsis and septic shock. Matrix-Metalloproteinase 9 (MMP-9) has been shown to be elevated in acute stress hyperglycemia, chronic hyperglycemia, and in patient with sepsis. The objective of this study was to examine the clinical and pathogenic link between MMP-9 and blood glucose (BG) levels in patients with early severe sepsis and septic shock.

Methods

We prospectively examined 230 patients with severe sepsis and septic shock immediately upon hospital presentation and before any treatment including insulin administration. Clinical and laboratory data were obtained along with blood samples for the purpose of this study. Univariate tests for mean and median distribution using Spearman correlation and analysis of variance (ANOVA) were performed. A p value ≤ 0.05 was considered statistically significant.

Results

Patients were grouped based on their presenting BG level (mg/dL): BG <80 (n = 32), 80–120 (n = 53), 121–150 (n = 38), 151–200 (n = 23), and > 201 (n = 84). Rising MMP-9 levels were significantly associated with rising BG levels (p = 0.043). A corresponding increase in the prevalence of diabetes for each glucose grouping from 6.3 to 54.1 % (p = 0.0001) was also found. As MMP-9 levels increased a significantly (p < 0.001) decreases in IL-8 (pg/mL) and ICAM-1 (ng/mL) were noted.

Conclusion

This is the first study in humans demonstrating a significant and early association between MMP-9 and BG levels in in patients with severe sepsis and septic shock. Neutrophil affecting biomarkers such as IL-8 and ICAM-1 are noted to decrease as MMP-9 levels increase. Clinical risk stratification using MMP-9 levels could potentially help determine which patients would benefit from intensive versus conventional insulin therapy. In addition, antagonizing the up-regulation of MMP-9 could serve as a potential treatment option in severe sepsis or septic shock patients.

Effects of a healthy Nordic diet on gene expression changes in peripheral blood mononuclear cells in response to an oral glucose tolerance test in subjects with metabolic syndrome: a SYSDIET sub-study

Background

Diet has a great impact on the risk of developing features of metabolic syndrome (MetS), type 2 diabetes mellitus (T2DM), and cardiovascular diseases (CVD). We evaluated whether a long-term healthy Nordic diet (ND) can modify the expression of inflammation and lipid metabolism-related genes in peripheral blood mononuclear cells (PBMCs) during a 2-h oral glucose tolerance test (OGTT) in individuals with MetS.

Methods

A Nordic multicenter randomized dietary study included subjects (n = 213) with MetS, randomized to a ND group or a control diet (CD) group applying an isocaloric study protocol. In this sub-study, we included subjects (n = 89) from three Nordic centers: Kuopio (n = 26), Lund (n = 30), and Oulu (n = 33) with a maximum weight change of ±4 kg, high-sensitivity C-reactive protein concentration ≤10 mg L⁻¹, and baseline body mass index <39 kg m⁻². PBMCs were isolated, and the mRNA gene expression analysis was measured by quantitative real-time polymerase chain reaction (qPCR). We analyzed the mRNA expression changes of 44 genes before and after a 2hOGTT at the beginning and the end of the intervention.

Results

The healthy ND significantly down-regulated the expression of toll-like receptor 4 (TLR4), interleukin 18 (IL18), and thrombospondin receptor (CD36) mRNA transcripts and significantly up-regulated the expression of peroxisome proliferator-activated receptor delta (PPARD) mRNA transcript after the 2hOGTT compared to the CD.

Conclusions

A healthy ND is able to modify the gene expression in PBMCs after a 2hOGTT. However, more studies are needed to clarify the biological and clinical relevance of these findings.

Electronic supplementary material

The online version of this article (doi:10.1186/s12263-016-0521-4) contains supplementary material, which is available to authorized users.

Vescalagin from Pink Wax Apple [Syzygium samarangense (Blume) Merrill and Perry] Alleviates Hepatic Insulin Resistance and Ameliorates Glycemic Metabolism Abnormality in Rats Fed a High-Fructose Diet

This study investigates the ameliorative effect of vescalagin (VES) isolated from Pink wax apple fruit on hepatic insulin resistance and abnormal carbohydrate metabolism in high-fructose diet (HFD)-induced hyperglycemic rats. The results show that in HFD rats, VES significantly reduced the values of the area under the curve for glucose in an oral glucose tolerance test and the homeostasis model assessment of insulin resistance index. VES significantly enhanced the activity of hepatic antioxidant enzymes while reducing thiobarbituric acid-reactive substances in HFD rats. Western blot assay revealed that VES reduced hepatic protein expression involved in inflammation pathways while up-regulating expression of hepatic insulin signaling-related proteins. Moreover, VES up-regulated the expression of hepatic glycogen synthase and hepatic glycolysis-related proteins while down-regulating hepatic gluconeogenesis-related proteins in HFD rats. This study suggests some therapeutic potential of VES in preventing the progression of diabetes mellitus.

Targeting inflammation in metabolic syndrome

The metabolic syndrome (MetS) is comprised of a cluster of closely related risk factors, including visceral adiposity, insulin resistance, hypertension, high triglyceride, and low high-density lipoprotein cholesterol; all of which increase the risk for the development of type 2 diabetes and cardiovascular disease. A chronic state of inflammation appears to be a central mechanism underlying the pathophysiology of insulin resistance and MetS. In this review, we summarize recent research which has provided insight into the mechanisms by which inflammation underlies the pathophysiology of the individual components of MetS including visceral adiposity, hyperglycemia and insulin resistance, dyslipidemia, and hypertension. On the basis of these mechanisms, we summarize therapeutic modalities to target inflammation in the MetS and its individual components. Current therapeutic modalities can modulate the individual components of MetS and have a direct anti-inflammatory effect. Lifestyle modifications including exercise, weight loss, and diets high in fruits, vegetables, fiber, whole grains, and low-fat dairy and low in saturated fat and glucose are recommended as a first line therapy. The Mediterranean and dietary approaches to stop hypertension diets are especially beneficial and have been shown to prevent development of MetS. Moreover, the Mediterranean diet has been associated with reductions in total and cardiovascular mortality. Omega-3 fatty acids and peroxisome proliferator-activated receptor α agonists lower high levels of triglyceride; their role in targeting inflammation is reviewed. Angiotensin-converting enzyme inhibitors, angiotensin receptor blockers, and aldosterone blockers comprise pharmacologic therapies for hypertension but also target other aspects of MetS including inflammation. Statin drugs target many of the underlying inflammatory pathways involved in MetS.

Effect of local insulin injection on wound vascularization in patients with diabetic foot ulcer

The aim of the present study was to investigate the effect of local insulin injection on granulation tissue formation in the wounds of patients with diabetic foot ulcer. Thirty-two patients with diabetic foot ulcer were randomly divided into an insulin (n=18) and a control (n=14) group. In the diabetic foot ulcer wound, the insulin group were administered insulin and the control group were administered an equal volume of saline. Prior to injection and at 0.5, 1.0, 2.0 and 4.0 h after injection, the fingertip blood glucose levels were determined. The growth of granulation tissue was assessed continuously for 12 days. Wound tissue was harvested at 0, 5, 7 and 12 days for the detection of CD34 expression by immunohistochemistry. The microvessel density (MVD) was calculated. No significant difference in the fasting blood glucose level was found between the two groups at any time-point (P>0.05). Growth of granulation tissue in the insulin group was more marked from 7 days after local insulin injection (24.87±0.24) and was significantly different from that in the control group (18.66±0.45) (P<0.01). New vessels were observed in the insulin group 3 days after insulin injection; however, there was no significant difference in MVD compared with the control group (P>0.05). The MVD in the insulin group increased markedly from 5 days after treatment, and the difference between the two groups was significant (P<0.01). In conclusion, local injection of insulin into the base of a diabetic foot ulcer has a significant effect on systemic blood glucose and may promote wound healing by improving the growth of granulation tissue.

Postprandial adiponectin and gelatinase response to a high-fat versus an isoenergetic low-fat meal in lean, healthy men

OBJECTIVE

Evidence suggests that an acute systemic inflammatory response is invoked after consumption of a high-energy meal. Postprandial regulation of adiponectin, an adipose tissue-derived, anti-inflammatory hormone, and the gelatinases, matrix metalloproteinase (MMP)-2 and MMP-9, endopeptidases implicated in a diverse range of inflammatory processes, remain inconclusive. The aim of this study was to assess the postprandial effect of a high-energy (1212 kcal) meal on plasma adiponectin, MMP-2 and MMP-9 activity, glucose, insulin, triacylglycerols, total cholesterol, high-density lipoprotein cholesterol, and the differential effects on these parameters depending on whether the test meal was high fat (HF; 46 g fat, 1210 kcal) or isoenergetic and low fat (LF; 15 g fat, 1214 kcal energy).

METHODS

Test meals were consumed by 17 lean, healthy men on two separate occasions with blood samples collected by venipuncture at baseline (0 h) and 1 and 3 h after consumption of each test meal.

RESULTS

At baseline, no significant difference was seen in the parameters between the two groups, except for MMP-2, MMP-9, and total cholesterol. Over the 3-h postprandial period, no significant differential effect of the HF versus the LF test meal was observed on adiponectin, MMP-2, MMP-9, or on metabolic markers other than triacylglycerol, which increased significantly in response to the HF test meal (time × treatment, P = 0.002). When analyzed independent of time, MMP-2 (treatment, P = 0.006), MMP-9 (treatment, P = 0.022), and glucose (treatment, P = 0.026) were lower after consumption of the HF meal compared with the LF test meal. When analyzed independent of treatment, adiponectin increased over the 3-h postprandial period (time, P = 0.031), but there was no change in MMP-2 or MMP-9 (time, P = 0.503 and P = 0.525, respectively). Over the 3-h postprandial period, insulin (time, P < 0.001) and total cholesterol (time, P = 0.002) increased, whereas glucose (time, P < 0.001) and high-density lipoprotein cholesterol (time, P < 0.001) decreased.

CONCLUSION

No differential effects of a HF versus a LF isoenergetic meal were seen on postprandial adiponectin or the gelatinases. Adiponectin increased in response to a high-energy meal independent of treatment, and the gelatinases were lower in response to the HF versus the LF isoenergetic meal, independent of time point. Given the considerable amount of time that humans spend in the postprandial state, additional research is necessary to further understand inflammatory changes in this state.

Reduction of AMPK activity and altered MAPKs signalling in peripheral blood mononuclear cells in response to acute glucose ingestion following a short-term high fat diet in young healthy men

BACKGROUND

Peripheral blood mononuclear cells (PBMCs) are known to respond to systematic changes in nutrient availability. The impact of a short-term high fat diet (HFD), with and without acute glucose ingestion, on the energy-sensing enzyme 5' AMP-activated protein kinase (AMPK) as well as mitochondrial oxidative phosphorylation (OXPHOS) proteins in PBMCs is currently unknown.

METHODS

Nine healthy, lean young males participated in a 7 day HFD intervention, designed to induce transient glucose intolerance. The phosphorylation status and total protein content of AMPK and inflammatory mitogen-activated protein kinases (MAPKs), and total OXPHOS protein in PBMCs, along with circulating cytokines, were assessed in the fasted state and following an oral glucose tolerance test (OGTT) before and after the HFD.

RESULTS

One week of HFD resulted in relative glucose intolerance. The HFD resulted in a reduction of AMPK phosphorylation under fasting basal conditions and following the OGTT (both P<0.05), while there were no differences in OXPHOS protein expression. Although the short-term HFD had no effect on basal phosphorylation of p38, JNK or ERK1/2, the activation of MAPKs signalling in response to glucose ingestion was attenuated post-HFD as compared to pre-HFD (P<0.05 for all). Circulating cytokines were not significantly affected by the HFD.

CONCLUSIONS

We conclude that impaired glucose tolerance in response to 7 day HFD resulted in decreased AMPK activity and impaired glucose-stimulated MAPK activation following glucose ingestion in vivo in PBMCs from young, lean subjects. Further studies are warranted to explore how dietary manipulations impact interplay between AMPK and inflammatory signalling, along with immune function, in PBMCs.

Association between early glycemic control and improvements in markers of coagulation and fibrinolysis in patients with septic shock-induced stress hyperglycemia

PURPOSE

The purpose of this study is to evaluate the coagulation and inflammatory profiles in septic shock patients with baseline hyperglycemia under glycemic control.

METHODS

Prospective, observational study conducted in an intensive care unit of a university hospital, including 41 septic shock nondiabetic patients with hyperglycemia (n = 21) or normoglycemia (n = 20) profiles at baseline. Hyperglycemic patients received a glucose control protocol (target glycemia, <150 mg/dL). Metabolic, inflammatory, and coagulation markers were measured at baseline and after 24 hours.

RESULTS

Median glycemic values between groups were different at baseline but not after 24 hours. Baseline coagulation profile was similar in both groups with elevated levels of coagulation markers, reduced factor VII, protein C, and antithrombin activities and fibrinolysis impairment. Normoglycemic patients had unchanged coagulation markers after 24 hours. After treatment, previously hyperglycemic patients exhibited increased plasminogen concentrations (P = .03) and reduced levels of plasminogen activator inhibitor 1 (P = .01) and tissue plasminogen activator (P = .03) as compared with baseline. They also had higher factor VII (P = .03), protein C (P = .04), and antithrombin (P = .04) activities than normoglycemic patients. Inflammatory markers were elevated in both groups and improved after 24 hours, independently of the glycemic profile.

CONCLUSIONS

Glycemic control during septic shock is associated with improvements in coagulation and fibrinolysis parameters compared with baseline and normoglycemic patients.

Glycemic control after brain injury: boon and bane for the brain

Hyperglycemia is a common phenomenon in the early phase of brain injury (BI). The management of blood glucose levels after BI, however, is subject of a growing debate. The occurrence of elevated blood glucose concentrations is linked to increased mortality and worse neurologic outcomes indicating the necessity for therapeutic glucose-lowering. Intensive glucose-lowering therapy, on the other hand, inevitably results in an increased rate of hypoglycemic episodes with detrimental effects on the injured brain. In this review, we give an overview on the current knowledge about causes and pathophysiological consequences of dysglycemia in patients with BI and offer some suggestions for clinical glucose management.

Aldose reductase drives hyperacetylation of Egr-1 in hyperglycemia and consequent upregulation of proinflammatory and prothrombotic signals

Sustained increases in glucose flux via the aldose reductase (AR) pathway have been linked to diabetic vascular complications. Previous studies revealed that glucose flux via AR mediates endothelial dysfunction and leads to lesional hemorrhage in diabetic human AR (hAR) expressing mice in an apoE(-/-) background. Our studies revealed sustained activation of Egr-1 with subsequent induction of its downstream target genes tissue factor (TF) and vascular cell adhesion molecule-1 (VCAM-1) in diabetic apoE(-/-)hAR mice aortas and in high glucose-treated primary murine aortic endothelial cells expressing hAR. Furthermore, we observed that flux via AR impaired NAD(+) homeostasis and reduced activity of NAD(+)-dependent deacetylase Sirt-1 leading to acetylation and prolonged expression of Egr-1 in hyperglycemic conditions. In conclusion, our data demonstrate a novel mechanism by which glucose flux via AR triggers activation, acetylation, and prolonged expression of Egr-1 leading to proinflammatory and prothrombotic responses in diabetic atherosclerosis.

Nutritional countermeasures targeting reactive oxygen species in cancer: from mechanisms to biomarkers and clinical evidence

Reactive oxygen species (ROS) exert various biological effects and contribute to signaling events during physiological and pathological processes. Enhanced levels of ROS are highly associated with different tumors, a Western lifestyle, and a nutritional regime. The supplementation of food with traditional antioxidants was shown to be protective against cancer in a number of studies both in vitro and in vivo. However, recent large-scale human trials in well-nourished populations did not confirm the beneficial role of antioxidants in cancer, whereas there is a well-established connection between longevity of several human populations and increased amount of antioxidants in their diets. Although our knowledge about ROS generators, ROS scavengers, and ROS signaling has improved, the knowledge about the direct link between nutrition, ROS levels, and cancer is limited. These limitations are partly due to lack of standardized reliable ROS measurement methods, easily usable biomarkers, knowledge of ROS action in cellular compartments, and individual genetic predispositions. The current review summarizes ROS formation due to nutrition with respect to macronutrients and antioxidant micronutrients in the context of cancer and discusses signaling mechanisms, used biomarkers, and its limitations along with large-scale human trials.

Glucose ingestion stimulates atherothrombotic inflammation in polycystic ovary syndrome

Women with polycystic ovary syndrome (PCOS) have chronic low-grade inflammation that can increase the risk of atherothrombosis. We performed a cross-sectional study to examine the effect of glucose ingestion on markers of atherothrombotic inflammation in mononuclear cells (MNC) of 16 women with PCOS (8 lean, 8 obese) and 16 weight-matched controls. Activator protein-1 (AP-1) activation and the protein content of early growth response-1 (EGR-1), matrix matalloproteinases-2 (MMP2), and tissue factor (TF) were quantified from MNC obtained from blood drawn fasting and 2 h after glucose ingestion. Plasma MMP9 and C-reactive protein (CRP) were measured from fasting blood samples. Truncal fat was determined by DEXA. Lean women with PCOS exhibited greater AP-1 activation and MMP2 protein content after glucose ingestion and higher plasma MMP9 and CRP levels than lean controls. Obese women with PCOS exhibited greater EGR-1 and TF protein content after glucose ingestion, and plasma CRP levels were even higher compared with lean subjects regardless of PCOS status. Truncal fat correlated with MMP9 and CRP levels and glucose-stimulated increases in AP-1 activation and EGR-1 and TF protein content. Testosterone correlated with glucose-stimulated AP-1 activation, and androstenedione correlated with MMP9 and CRP levels and glucose-stimulated AP-1 activation. Thus, both PCOS and obesity contribute to an atherothrombotic state in which excess abdominal adiposity and hyperandrogenism may be specific risk factors for developing atherothrombosis.

Hyperglycemia as a Risk Factor of Ischemic Stroke

Diabetes is considered a major risk factor for stroke and is associated with worsened stroke outcomes. Here, we discuss and summarize the mechanisms that have been associated with the increased risk of stroke due to the hyperglycemia in diabetes mellitus. In diabetic stroke models, hyperglycemia exaggerates the following damaging processes: acidosis, accumulation of reactive oxygen species/reactive nitrogen, inflammation and mitochondrial dysfunction. Understanding the mechanism of diabetes acting as a stroke risk factor will definitely assist to reveal issues related to drug metabolism and toxicity in diabetic stroke. In addition, it is suggested that future studies may focus on the mechanisms mediating blood-brain barrier and astrocytes dysfunction under hyperglycemic stroke.

Human transcriptome analysis of acute responses to glucose ingestion reveals the role of leukocytes in hyperglycemia-induced inflammation

Glucose ingestion-induced hyperglycemia has been known to induce inflammation, which is related to the pathogenesis of diabetic complications. To examine acute gene expression responses to physiological oral glucose ingestion in human circulating leukocytes, we conducted a microarray study of human circulating leukocytes sampled before, 1 h after, and 2 h after glucose ingestion in community-based participants without previous histories of diabetes (n = 60). Ingestion of 75 g glucose successfully induced acute hyperglycemia (glucose concentration 91.6 ± 5.3 mg/dl for fasting and 180.7 ± 48.5 mg/dl for 1 h after glucose ingestion). Oral glucose ingestion significantly increased the expressions of 23 genes and decreased the expressions of 13 genes [false discovery rate (FDR) P value <0.05]. These genes are significantly involved in immunity by way of natural killer cell-mediated immunity, granulocyte-mediated immunity, and the cytokine-mediated signaling pathway (FDR P value <0.05). The present study demonstrated 36 genes that showed acute gene expression change in human leukocytes within 1 h after glucose ingestion, suggesting that leukocytes participate in the inflammatory process induced by acute hyperglycemia. We believe that these results will provide some basic insight into the role of leukocytes in hyperglycemia-induced inflammation and the pathogenesis of diabetic complications.

Adipocytokine changes caused by low-carbohydrate compared to conventional diets in obesity

Modest weight loss causing a decrease in insulin resistance has been linked to favorable changes in the adipocyte cytokines leptin, adiponectin, and tumor necrosis factor-alpha (TNF-alpha), three emerging risk factors of cardiovascular disease. We previously observed a significant reduction in insulin resistance with weight loss in obese subjects on a low-carbohydrate diet. Based on these previous findings, we hypothesize that a low-carbohydrate diet would be more beneficial in changing leptin, TNF-alpha, and adiponectin than a conventional diet. A total of 75 severely obese (body mass index >/=35 kg/m(2)) subjects were randomized to instruction of 6 months of a low-carbohydrate diet or a conventional calorie-restricted diet. Serum levels of leptin, TNF-alpha, TNF-alpha-soluble receptor 1 (TNF-alpha SR1), and adiponectin were measured at baseline and after 6 months of dietary intervention. Subjects on low-carbohydrate diets experienced a greater decrease in leptin when compared to conventional dieters (p < 0.001). TNF-alpha increased significantly in nondiabetic subjects on conventional vs. low-carbohydrate diets (p = 0.003). Adiponectin and TNF-alpha SR1 change were not significantly different between diets. This is the first study to report the effects of dietary macronutrient alterations on serum adipocytokines in a randomized controlled trial. The greater reduction in insulin resistance and weight on a low-carbohydrate diet, in the short term, translates into greater improvement in leptin but with no significant improvements in TNF-alpha or adiponectin in patients with moderate to severe obesity after 6 months of dietary intervention.

A novel view of metabolic syndrome

The metabolic syndrome, as described by Reaven, is a combination of obesity, insulin resistance, hypertension, hypertriglyceridemia, low HDL cholesterol, and hyperinsulinemia. The syndrome was recognized as a very high pro-atherogenic risk causing coronary heart disease. More recently, other features like an elevated plasma PAI -1 and CRP have been added to the syndrome. In view of the recent data demonstrating that insulin exerts an anti-inflammatory effect while macronutrients exert a pro-inflammatory effect, we are in a better position to explain not only why an insulin resistant state like the metabolic syndrome is pro-inflammatory but also to explain how it develops. This review discusses the relevance of these recent observations and puts into perspective the pathogenesis of various features of the metabolic syndrome and also predicts some features which may get incorporated into it in the future.

Cardiovascular benefits of exogenous insulin

CONTEXT

Recent studies on mediators of inflammation, experimental models of atherosclerosis, and acute ischemia have identified novel mechanisms through which insulin may exert cardiovascular protective effects. This review aims to summarize current knowledge regarding the cardiovascular, antiinflammatory, and antiatherogenic effects of insulin, and the effect of intensive glycemic control in acute cardiovascular disease.

EVIDENCE ACQUISITION

Publications of interest were identified using preselected MeSH terminology and keywords to search online databases such as PubMed and OVID for the period January 1988 to February 2012. Relevant publications were obtained and reviewed by two independent observers, then evaluated a priori against the following criteria: study quality, main clinical outcomes, and applicability to clinical practice.

EVIDENCE SYNTHESIS

Insulin has been shown to exert vasodilatory, antiinflammatory, and antiatherogenic effects in experimental models, independent of its glucose-lowering effects. Additionally, glucose is known to exert potent proinflammatory, prothrombotic, and proapoptotic effects during myocardial infarct, indicative that hyperglycemia is likely to be injurious to the heart. In this context, through its nonmetabolic and metabolic (glucose-lowering) effects, insulin is likely to be cardioprotective and to improve clinical outcomes in acute myocardial infarction.

CONCLUSIONS

Despite promising experimental data and evidence of benefit from single-center randomized clinical trials, clinical evidence supporting the cardioprotective effects of insulin from a multicenter randomized clinical trial is still lacking. Future prospective studies with insulin infused at adequate concentrations, individually titrated to achieve and maintain euglycemia (blood glucose < 140 mg/dl) and minimize hypoglycemia, are required to investigate the role of insulin in the management of patients with acute cardiovascular disease.

Diabetes and pancreatic cancer

Type 2 diabetes mellitus is likely the third modifiable risk factor for pancreatic cancer after cigarette smoking and obesity. Epidemiological investigations have found that long-term type 2 diabetes mellitus is associated with a 1.5-fold to 2.0-fold increase in the risk of pancreatic cancer. A causal relationship between diabetes and pancreatic cancer is also supported by findings from prediagnostic evaluations of glucose and insulin levels in prospective studies. Insulin resistance and associated hyperglycemia, hyperinsulinemia, and inflammation have been suggested to be the underlying mechanisms contributing to development of diabetes-associated pancreatic cancer. Signaling pathways that regulate the metabolic process also play important roles in cell proliferation and tumor growth. Use of the antidiabetic drug metformin has been associated with reduced risk of pancreatic cancer in diabetics and recognized as an antitumor agent with the potential to prevent and treat this cancer. On the other hand, new-onset diabetes may indicate subclinical pancreatic cancer, and patients with new-onset diabetes may constitute a population in whom pancreatic cancer can be detected early. Biomarkers that help define high-risk individuals for clinical screening for pancreatic cancer are urgently needed. Why pancreatic cancer causes diabetes and how diabetes affects the clinical outcome of pancreatic cancer have yet to be fully determined. Improved understanding of the pathological mechanisms shared by diabetes and pancreatic cancer would be the key to the development of novel preventive and therapeutic strategies for this cancer.