Diabetes mellitus, inflammation, obesity: proposed treatment pathways for current and future therapies

Assessment of the Phenolic Profiles, Hypoglycemic Activity, and Molecular Mechanism of Different Highland Barley (Hordeum vulgare L.) Varieties

The phenolic profiles, hypoglycemic activity, and molecular mechanism of the effect on type 2 diabetes mellitus (T2DM) of four highland barley varieties were investigated in the present study. The fundamental phenolics in highland barley were ferulic acid, naringin, and catechin, which mainly existed in bound form. These varieties showed favorable hypoglycemic activity via inhibition of α-glucosidase and α-amylase activities, enhancement of glucose consumption, glycogen accumulation and glycogen synthase 2 (GYS2) activity, and down-regulation of glucose-6-phosphatase (G6Pase) and phosphoenolpyruvate carboxykinase (PEPCK) activities. Specifically, ZQ320 variety exhibited the strongest hypoglycemic activity compared to the other varieties. Highland barley phenolics could inhibit gluconeogenesis and motivate glycogen synthesis via down-regulating the gene expression of G6Pase, PEPCK, and glycogen synthase kinase 3β (GSK3β), while activating the expression of insulin receptor substrate-1 (IRS-1), phosphatidylinositol 3 kinase (PI3K), serine/threonine kinase (Akt), GYS2, and glucose transporter type 4 (GLUT4). Therefore, phenolics from highland barley could be served as suitable candidates for therapeutic agent in T2DM to improve human health.

Chronic Osteomyelitis Increases the Incidence of Type 2 Diabetes in Humans and Mice

Background: To compare the risk of type 2 diabetes (T2DM) between patients with and without chronic osteomyelitis (COM), both in humans and in mice, and to explore risk factors in COM patients who developed T2DM.

Methods: One hundred seven patients with COM and 114 patients without COM were consecutively enrolled and retrospectively analysed. Clinical data concerning the time to develop diabetes, glucose metabolism, lipid metabolism, inflammatory factors, mental health and frequency of specialist visits were collected. A mouse model of osteomyelitis was used to verify the presence of impaired glucose metabolism and depression. All data were processed by SPSS.

Results: The incidence of T2DM was 2.37-fold higher in patients with COM than in those without. In COM patients, subjects with T2DM (DDM) had higher BMI, less exercise and more frequent visits to specialists than those without (Con). Glucose and lipid metabolism were worse in patients with DDM. Patients with DDM had higher levels of white blood cells (12.9±2.1×109/L vs. 11.7±2.2×109/L, p=0.027), CRP (28.4±4.5 mg/L vs. 22.0±4.8 mg/L, p<0.001), TNF-α (13.5±5.0 pg/mL vs. 9.4±2.6 pg/mL, p= 0.003) and IL-6 (12.9±3.2 pg/mL vs. 9.2±2.7 pg/mL, p<0.001). Significantly increased fasting blood glucose concentrations and impairment of oral glucose tolerance tests were also observed in mice modelling osteomyelitis, which were accompanied by elevated TNF-α and IL-6 levels. Furthermore, the proportion of depression (63.2% vs. 35.2%, p=0.003) and severe anxiety (31.6% vs. 9.1%, p=0.002) were significantly higher in the DDM group. Osteomyelitis mice showed obvious depressive-like behaviours. The levels of TNF-α, IL-6, CRP, BMI, and LDL; lack of exercise; SAS; HAQ; and SF36 assessment were risk factors for the development of T2DM in COM patients.

Conclusions: Chronic osteomyelitis increased the incidence of T2DM in both humans and mice. Inflammation, mental illness and lack of exercise were risk factors for the occurrence of T2DM in osteomyelitis. Comprehensive consideration of patient history, including metabolism and mental health, is needed in planning future treatment.

Attenuation of inflammatory response by a novel chalcone protects kidney and heart from hyperglycemia-induced injuries in type 1 diabetic mice

High glucose-induced inflammatory response in diabetic complications plays an important role in disease occurrence and development. With inflammatory cytokines and signaling pathways as important mediators, targeting inflammation may be a new avenue for treating diabetic complications. Chalcones are a class of natural products with various pharmacological activities. Previously, we identified L2H17 as a chalcone with good anti-inflammatory activity, inhibiting LPS-induced inflammatory response in macrophages. In this study, we examined L2H17's effect on hyperglycemia-induced inflammation both in mouse peritoneal macrophages and a streptozotocin-induced T1D mouse model. Our results indicate that L2H17 exhibits a strong inhibitory effect on the expression of pro-inflammatory cytokines, cell adhesion molecules, chemokines and macrophage adhesion via modulation of the MAPK/NF-κB pathway. Furthermore, in vivo oral administration of L2H17 resulted in a significant decrease in the expression of pro-inflammatory cytokines and cell adhesion molecules, contributing to a reduction of key markers for renal and cardiac dysfunction and improvements in fibrosis and pathological changes in both renal and cardiac tissues of diabetic mice. These findings provide the evidence supporting targeting MAPK/NF-κB pathway may be effective therapeutic strategy for diabetic complications, and suggest that L2H17 may be a promising anti-inflammatory agent with potential as a therapeutic agent in the treatment of renal and cardiac diabetic complications.

Resveratrol and its metabolites bind to PPARs

Resveratrol, a modulator of several signaling proteins, can exert off-target effects involving the peroxisome proliferator-activated receptor (PPAR) transcription factors. However, evidence for the direct interaction between this polyphenol and PPARs is lacking. Here, we addressed the hypothesis that resveratrol and its metabolites control aspects of PPAR transcriptional activity through direct interaction with PPARs. Bioaffinity chromatographic studies with the immobilized ligand-binding domains (LBDs) of PPARγ and PPARα and isothermal titration calorimetry allowed the binding affinities of resveratrol, resveratrol 3-O-glucuronide, resveratrol 4-O-glucuronide, and resveratrol 3-O-sulfate to both PPAR-LBDs to be determined. Interaction of resveratrol, resveratrol 3-O-glucuronide, and resveratrol 4-O-glucuronide with PPARγ-LBD occurred with binding affinities of 1.4, 1.1, and 0.8 μM, respectively, although only resveratrol bound to the PPARα-LBD with a binding affinity of 2.7 μM. Subsequently, X-ray crystallographic studies were carried out to characterize resveratrol binding to the PPARγ-LBD at the molecular level. The electron density map from the crystal structure of the complex between PPARγ-LBD and resveratrol revealed the presence of one molecule of resveratrol bound to the LBD of PPARγ, with the ligand occupying a position close to that of other known PPARγ ligands. Transactivation assays were also performed in HepG2 cells, with the results showing that resveratrol was not a PPAR agonist but instead was able to displace rosiglitazone from PPARγ and Wy-14643 from PPARα with IC50 values of (27.4±1.8) μM and (31.7±2.5) μM, respectively. We propose that resveratrol acts as a PPAR antagonist through its direct interaction with PPARγ and PPARα.

mTOR: more targets of resveratrol?

Resveratrol (RSV) is a natural polyphenol produced by plants and is proposed to have multiple beneficial effects on health. In recent years, the interest in this molecule has increased nearly exponentially following the major findings that RSV (I) is chemo-preventive in some cancer models, (II) is cardio-protective and (III) has positive effects on metabolism in mammals and increases lifespan in lower organisms. Mechanistic target of rapamycin (mTOR) is a central controller of cell growth, proliferation, metabolism and angiogenesis. As a part of the mTORC1 and mTORC2 complexes, the mTOR kinase plays a key role in several pathways involved in cancer and metabolic diseases. Recent studies suggest that modulation of the mTOR signalling pathway could play an important role in mediating the beneficial effects of RSV. Therefore, this review summarises the current findings regarding RSV and its inhibition/activation of the proteins in the mTOR pathway, and thereby propose the proteins of the mTOR cascade to be primary targets for RSV. RSV affects many different targets related to mTOR, and it is not clear which is most relevant. However, most frequently, RSV is found to inhibit the activity of the mTOR pathway proteins, and to activate AMPK and LKB1, which can suppress mTOR signalling. Thus, it appears that RSV plays a role in modulation of proteins of the mTOR pathway although more research is still needed to fully understand the interaction.

Association of serum ceruloplasmin level with obesity: some components of metabolic syndrome and high-sensitive C-reactive protein in Iran

BACKGROUND

One of the mechanisms that has been suggested for obesity related metabolic disturbances is obesity-induced inflammation. Pro-inflammatory cytokines generated in adipose tissue can increase hepatic synthesis of inflammation-sensitive plasma proteins (ISPs) including ceruloplasmin (Cp). In this study we aimed to investigate the relation between serum Cp level and obesity.

METHODS

61 persons with body mass index (BMI) ≥ 25 kg/m² (case group) and 61 persons with BMI < 25 kg/m² (control group) were included in this study with a case-control design. Serum Cp levels, triglyceride level, fating blood glucose, total cholesterol, LDL-cholesterol, HDL-cholesterol and hsCRP were measured in both groups.

RESULTS

We did not observe any significant association between serum Cp level and BMI in all subjects [OR: 1.02 (CI, 0.967 to 1.07)] and in case (β = 0.012, P = 0.86) and control groups (β = 0.49, P = 0.07) separately. However, in control group, this positive association was marginally significant. We found a positive correlation between serum Cp level and serum triglyceride level.

CONCLUSION

Serum Cp level was not related to obesity in this group of subjects. None of the baseline variables could predict obesity in this group of subjects, including serum Cp level, FBS, total cholesterol, LDL and HDL- cholesterols and hsCRP.

A road map to Translational Medicine in Qatar and a model for the world

Translational Medicine (TM) in Qatar is part of a concerted effort of the Qatari medical and scientific leadership supported by a strong political will by Qatari authorities to deliver world-class health care to Qatari residents while participating in the worldwide quest to bridge the gap between bench-to-bedside-to-community. TM programs should embrace the Qatar National vision for research to become an international hub of excellence in research and development, based on intellectual merit, contributing to global knowledge and adhering to international standards, to innovate by translating new and original ideas into useful applications, to be inclusive at the national and international level, to build and maintain a competitive and diversified economy and ultimately improve the health and well-being of the Qatar’s population. Although this writing focuses on Qatar, we hope that the thoughts expressed here may be of broader use for the development of any TM program particularly in regions where an established academic community surrounded by a rich research infrastructure and/or a vibrant biotechnology enterprise is not already present.

Decreased plasma levels of ceruloplasmin after diet-induced weight loss in obese women

BACKGROUND

Plasma ceruloplasmin (Cp) has been shown to be a risk factor for cardiovascular disease and also to be associated with obesity. However, it is not known whether weight loss could decrease the plasma Cp levels.

AIM

To investigate the effect of diet-induced weight loss on plasma Cp in obese women.

SUBJECTS AND METHODS

Sixty-seven healthy obese women [age =33.4±8.7 yr, body mass index (BMI) =36.0±4.8 kg/m2] were entered into a medically supervised program aimed at reducing body weight by 10% or more. Weight loss was achieved through a diet providing a daily energy deficit of 500-1000 kcal/day. In addition, all patients were prescribed to use 50 g of a fiber supplement per day. For all subjects, assessment of dietary intake, anthropometric indices, and plasma levels of C-reactive protein and Cp was performed at the first visit and repeated at 12th week of follow-up.

RESULTS

By completing the program, weight (Δ=-9.5%, p<0.0001), BMI (Δ=-9.7%, p<0.0001), waist-circumference (Δ=-6.1%, p<0.0001), and triceps skinfold thickness (Δ=-14.9%, p<0.0001) significantly decreased. Plasma Cp significantly decreased after 12 weeks of dietary intervention (33.6±5.6 mg/dl vs 25.2±5.8 mg/dl, p<0.0001). Percent change in Cp was correlated with percent change in waist-circumference (r=446, p=0.015).

CONCLUSION

Our study suggests that an improved body composition induced by restriction of energy intake is associated with decreased serum concentrations of Cp in obese women which in turn might have reduced the subjects' risk of developing cardiovascular disease.

The risk of cancer in people with diabetes and chronic kidney disease

BACKGROUND

Diabetes and chronic kidney disease (CKD) are both associated with an increased risk of cancer but it is unclear whether diabetes complicated by CKD further augments an individual's cancer risk. The aim of our study was to determine the association of CKD [defined as an estimated glomerular filtration rate (eGFR) < 60 mL/min] with the overall and site-specific risks of incident cancers among individuals with Type 2 diabetes.

METHODS

Cox proportional hazard regression models and competing risk analyses were used to examine the univariate and multivariate adjusted associations between reduced kidney function and the overall and site-specific risks of cancer in participants enrolled in the Action in Diabetes and Vascular disease: Preterax and Diamicron MR controlled evaluation (ADVANCE) trial.

RESULTS

Over a median follow-up of 5.0 years, 700 malignant neoplasms occurred in the 11 140 (6.4%) participants. There was no increase in overall cancer risk [adjusted hazard ratio: 1.07 (95% confidence interval: 0.89-1.29, P = 0.50)] or site-specific cancer risk for individuals with CKD (defined as eGFR < 60 mL/min) compared to those without CKD at baseline. These results were robust to multiple methods and thresholds used to estimate CKD.

CONCLUSIONS

Mild to moderate CKD does not increase the risk of cancer in people with Type 2 diabetes. ADVANCE is registered with ClincalTrial.gov (number NCT00145925).

Comprehensive evidence-based assessment and prioritization of potential antidiabetic medicinal plants: a case study from canadian eastern james bay cree traditional medicine

Canadian Aboriginals, like others globally, suffer from disproportionately high rates of diabetes. A comprehensive evidence-based approach was therefore developed to study potential antidiabetic medicinal plants stemming from Canadian Aboriginal Traditional Medicine to provide culturally adapted complementary and alternative treatment options. Key elements of pathophysiology of diabetes and of related contemporary drug therapy are presented to highlight relevant cellular and molecular targets for medicinal plants. Potential antidiabetic plants were identified using a novel ethnobotanical method based on a set of diabetes symptoms. The most promising species were screened for primary (glucose-lowering) and secondary (toxicity, drug interactions, complications) antidiabetic activity by using a comprehensive platform of in vitro cell-based and cell-free bioassays. The most active species were studied further for their mechanism of action and their active principles identified though bioassay-guided fractionation. Biological activity of key species was confirmed in animal models of diabetes. These in vitro and in vivo findings are the basis for evidence-based prioritization of antidiabetic plants. In parallel, plants were also prioritized by Cree Elders and healers according to their Traditional Medicine paradigm. This case study highlights the convergence of modern science and Traditional Medicine while providing a model that can be adapted to other Aboriginal realities worldwide.

Resveratrol, MicroRNAs, Inflammation, and Cancer

MicroRNAs are short noncoding RNAs that regulate the expression of many target genes posttranscriptionally and are thus implicated in a wide array of cellular and developmental processes. The expression of miR-155 or miR-21 is upregulated during the course of the inflammatory response, but these microRNAs are also considered oncogenes due to their upregulation of expression in several types of tumors. Furthermore, it is now well established that inflammation is associated with the induction or the aggravation of nearly 25% of cancers. Therefore, the above microRNAs are thought to link inflammation and cancer. Recently, resveratrol (trans-3,4′,5-trihydroxystilbene), a natural polyphenol with antioxidant, anti-inflammatory, and anticancer properties, currently at the stage of preclinical studies for human cancer prevention, has been shown to induce the expression of miR-663, a tumor-suppressor and anti-inflammatory microRNA, while downregulating miR-155 and miR-21. In this paper we will discuss how the use of resveratrol in therapeutics may benefit from the preanalyses on the status of expression of miR-155 or miR-21 as well as of TGFβ1. In addition, we will discuss how resveratrol activity might possibly be enhanced by simultaneously manipulating the levels of its key target microRNAs, such as miR-663.

Plasma ceruloplasmin as a biomarker for obesity: a proteomic approach

OBJECTIVES

This study aimed to investigate new biomarkers of obesity particularly in relation with inflammation-associated proteins using protein differential display techniques.

DESIGN AND METHODS

Comparison of protein expression in plasma between non-obese (n=109, body mass index, BMI<25kg/m(2)) and obese (n=32, BMI≥25kg/m(2)) groups was carried out using two-dimensional gel electrophoresis (2-DE) analysis. ELISA was also performed for validation.

RESULTS

Among six differentially expressed protein spots, ceruloplasmin (Cp) and fibrinogen were over-expressed in obese group. Plasma Cp levels were significantly higher in obese group than non-obese group (34.0 ± 8.6 vs. 41.3 ± 12.7mg/dL, p<0.001) and positively correlated with age (r=0.253, p<0.005), BMI (r=0.265, p<0.001) and hsCRP (r=0.385, p<0.001). In stepwise multiple linear regression analysis, plasma Cp along with hsCRP were found predictors for obesity (adjusted β-coefficient=0.266, p<0.01).

CONCLUSION

Elevated plasma Cp levels were significantly associated with obesity, which may be suggested to be a marker of obesity.