Primary and Secondary Prevention Strategy for Cardiovascular Disease in Diabetes Mellitus

Recombinant fusion protein by lysozyme and antibacterial peptide enhances ischemic wound healing via angiogenesis and reduction of inflammation in diabetic db/db mice

Background & aims

Lysozyme and antibacterial peptides have been reported to broad-spectrum antibacterial activity and can further improve wound healing. The aim of this study was to assess the effectiveness of a recombinant fusion protein created by combining lysozyme and an antibacterial peptide in forming new vessels and wound healing in an ischemic hind limb.

Methods

An ischemic hind limb model was established by isolation and ligation of the femoral artery in diabetic db/db mice. Cutaneous wounds were created with or without ischemia. Adductor muscles and wounds were treated with or without the fusion protein.

Results

The fusion protein accelerated ischemic diabetic wound healing and attenuated impairment of ischemic adductor muscle . Further, the fusion protein elevated expression of platelet derived growth factor (PDGF) and vascular endothelial growth factor (VEGF) protein and mRNA in ischemic adductor muscle, reduced levels of tumor necrosis factor-alpha (TNF-α) and interleukin-6 (IL-6) in serum and expression of phosphorylated nuclear factor κB (p-NF-κB) and p-IKB α in ischemic adductor. The fusion protein also enhanced levels of phosphorylated VEGF and PDGF receptors in the ischemic adductor muscles from diabetic db/db mice.

Conclusion

The data showed that the beneficial effects of the fusion protein on ischemic wound healing may be associated with angiogenesis and reduction of inflammatory response in the ischemic adductor muscles of diabetic db/db mice.

The role of microRNAs in the healing of diabetic ulcers

MicroRNAs (miRNAs) are small protected molecules with a length of 18 to 25 nucleotides. Many studies have recently been conducted on miRNAs, illustrating their role in regulating many biological, physiological, and pathological activities, such as maintaining cellular signalling and regulating cellular pathways. The main role of miRNAs is to regulate the expression of genes after translation, which can lead to the destruction or suppression of translation by binding to mRNAs. As any change in the regulation of miRNAs is associated with several physiological abnormalities, such as type 2 diabetes and its complications, these molecules can be used for therapeutic purposes or as biomarkers for the diagnosis of diseases such as diabetes and its complications. In this review article, we will discuss important findings about the miRNAs and the role of these molecules in different phases of the wound-healing process of chronic wounds, especially diabetic ulcer.

The clinical evaluation of combined detection of microcirculation, lipid metabolism, and inflammatory-related factors in the treatment of diabetic nephropathy with atorvastatin

This study was designed to analyze the effects of atorvastatin on microcirculation, blood lipids, inflammatory factors, and characteristic markers in patients with diabetic nephropathy. A total of 170 patients with diabetic nephropathy randomly divided into control and study groups with 85 patients in each group. The control group was treated with diet and lifestyle intervention, and hypoglycemic drugs. The study group was additionally treated with atorvastatin. Nitric oxide (NO), endothelin-1 (ET-1), thromboxane-2 (TXB2), 6-ketone-prostaglandin F-1α (6-Keto-PGF-1α), superoxide dismutase (SOD), total cholesterol (TC), triacylglycerols (TGs), low-density lipoprotein (LDL), high-density lipoprotein (HDL), C-reactive protein (CRP), tumor necrosis factor alpha (TNF-α), interleukin-6 (IL-6), homocysteine (Hcy), cystatin C (CysC), and vascular endothelial growth factor (VEGF) levels were observed for 8 weeks. Post-treatment of atorvastatin, the levels of NO, 6-Keto-PGF-1α, and SOD were significantly higher than pre-treatment in both groups, while the levels of ET-1 and TXB2 were lower than pre-treatment ( P < 0.05). The levels of NO, 6-Keto-PGF-1α, and SOD in the study group post-treatment were significantly higher ( P < 0.05) than the control group, and the levels of ET-1 and TXB2 in the study group were lower than the control group. After 8 weeks, the levels of TC, TG, and LDL were significantly lower, while the level of HDL was significantly higher in the study group. The level of TC was lower in the control group of post-treatment, while the HDL level was higher than pre-treatment ( P < 0.05). The levels of CRP, TNF-α, and IL-6 in the study group of post-treatment were significantly lower than pre-treatment comparing to the control group ( P < 0.05). There was no statistical significance ( P > 0.05) for above-mentioned indicators in control groups of pre- and post-treatment. The levels of VEGF, CysC, and Hcy in the two groups were lower than pre-treatment. Atorvastatin could effectively improve all the study parameters.

Back to basics with active lifestyles: exercise is more effective than metformin to reduce cardiovascular risk in older adults with type 2 diabetes

To establish the effect of three types of treatment - multicomponent exercise (MEX); the oral hypoglycaemic drug metformin (MET); combined therapy comprising exercise plus metformin (MEXMET) - on cardiovascular risk in older adults with type 2 diabetes (T2D) and with comorbidities in an early stage of the disease (HbA1c < 7.5%). A sample of 284 participants was evaluated for multifactorial cardiovascular risk at baseline and at 24-month intervention according to anthropometric and hemodynamic components, lipid profile, glycaemia and cardiorespiratory fitness (CRF). Participants underwent one of three conditions: MEX (n = 59), training in three sessions per week; MET (n = 30), using metformin 850 mg twice daily; MEXMET (n = 195), combining exercise and metformin. After the 24-month intervention MEX and MEXMET showed more positive results than MET therapy. MEX decreased body mass (BM; 4%), waist circumference (WC; 4%), body mass index (BMI; 3%), systolic blood pressure (SBP; 11%), diastolic blood pressure (DBP; 11%), triglycerides (21%), and glycaemia (12%), and increased cardiorespiratory fitness (CRF; 18%). Conversely, the MET group showed increased WC (2%), waist-to-hip ratio (WHR) (3%), and SBP (5%). Differences between MEX and MET groups presented large effect sizes for BM, WC, WHR, SBP, DBP and CRF, and moderate effect sizes for BMI and glycaemia. MEX was the most effective therapy in decreasing cardiovascular risk in the early stage of T2D in older adults with multimorbidity and attenuated the adverse effects of pharmacological therapy in MEXMET treatment.

Almonds ameliorate glycemic control in Chinese patients with better controlled type 2 diabetes: a randomized, crossover, controlled feeding trial

BACKGROUND

Almonds can decrease glycemic index of co-consumed foods and are a rich source for oleic acid and α-tocopherol. The aim of the randomized, crossover, controlled feeding trial was to examine whether as compared to NCEP step II diet as control (CON), ~60 g/d almonds (ALM) added to CON would improve glucoregulation and cardiovascular disease (CVD) risk factors in 33 Chinese T2DM patients.

METHODS

Forty T2DM patients were enrolled and randomly assigned to receive CON or ALM for 12 wks after a 2-wk. run-in period. Blood and urine samples were collected in the beginning and at the end of each dietary intervention phase for the assessment of biomarkers of glucoregulation, lipid profile, inflammation, and oxidative stress.

RESULTS

While ALM had a better overall nutritional quality than CON, neither ALM nor CON improved the glycemic status as the primary study outcome and other CVD risk factors, except the circulating nitric oxide being decreased by ALM compared to CON. Among 27 of 33 patients with the baseline HbA1c ≤8, ALM decreased post-interventional fasting serum glucose and HbA1c by 5.9% and 3.0% as compared to that of CON, respectively (P = 0.01 and 0.04). Mean total and LDL-cholesterol concentrations were not changed by both diets.

CONCLUSIONS

These results suggest almonds incorporated into healthful diets can improve glycemic status in diabetic patients with a better glycemic control.

TRIAL REGISTRATION

NCT01656850, registered 13 January 2012.

Treatment of Diabetes Mellitus Using iPS Cells and Spice Polyphenols

Diabetes mellitus is a chronic disease that threatens human health. The disease is caused by a metabolic disorder of the endocrine system, and long-term illness can lead to tissue and organ damage to the cardiovascular, endocrine, nervous, and urinary systems. Currently, the disease prevalence is 11.4%, the treatment rate is 48.2%, and the mortality rate is 2.7% worldwide. Comprehensive and effective control of diabetes, as well as the use of insulin, requires further study to develop additional treatment options. Here, we reviewed the current reprogramming of somatic cells using specific factors to induced pluripotent stem (iPS) cells capable of repairing islet β cell damage in diabetes patients to treat patients with type 1 diabetes mellitus. We also discuss the shortcomings associated with clinical use of iPS cells. Additionally, certain polyphenols found in spices might improve glucose homeostasis and insulin resistance in diabetes patients, thereby constituting promising options for the treatment of type 2 diabetes.

Silencing of activin receptor-like kinase 7 alleviates aortic stiffness in type 2 diabetic rats

AIM

Arterial stiffness is an important feature of diabetic macrovascular complications. Activin receptor-like kinase 7 (ALK7), a member of type I transforming growth factor-β (TGF-β) receptors, is correlated with pathogenic risks of type 2 diabetes mellitus and cardiovascular diseases and may be involved in cardiovascular remodeling. We aimed to investigate whether ALK7 is implicated in diabetes-induced aortic stiffness.

METHODS

Type 2 diabetes was induced by high-fat diet and low-dose streptozotocin (STZ; 27.5 mg/kg). Forty rats were separated into four groups: control, diabetes, diabetes with empty virus and diabetes treated with ALK7-shRNA. The metabolic index, ALK 7 expression and aortic stiffness were evaluated. We used gene silencing method to investigate the role of ALK7 in the pathological development.

RESULTS

Diabetic rats showed increased blood glucose, cholesterol, triglyceride levels, severe insulin resistance and ALK7 overexpression. Diabetes enhanced aortic stiffness, as demonstrated by the loss and disruption of elastic fibers as well as by an increase in collagen fibers in the aortic media. ALK7 gene silencing ameliorated metabolic hyperlipidemia and insulin resistance. With ALK7 gene silencing, collagen content, elastin to collagen ratio, as well as collagen I-to-collagen III content ratio in diabetic rats were significantly decreased. Moreover, the phosphorylation level of Smad2/3 was markedly decreased after ALK7 gene silencing.

CONCLUSIONS

ALK7 gene silencing has a protective effect on diabetes-induced aortic stiffness, insulin resistance and hyperlipidemia, thus implicating a new potential therapeutic approach to diabetic macrovascular stiffness.

n-3 Fatty acids attenuate the risk of diabetes associated with elevated serum nonesterified fatty acids: the multi-ethnic study of atherosclerosis

OBJECTIVE

Chronically high nonesterified fatty acids (NEFAs) are a marker of metabolic dysfunction and likely increase risk of type 2 diabetes. By comparison, n-3 fatty acids (FAs) have been shown to have various health benefits and may protect against disease development. In 5,697 participants of the Multi-Ethnic Study of Atherosclerosis (MESA), we examined whether serum levels of NEFAs relate to risk of incident type 2 diabetes and further tested whether plasma n-3 FA levels may interact with this relation.

RESEARCH DESIGN AND METHODS

NEFAs were measured in fasting serum using an enzymatic colorimetric assay and phospholipid n-3 FAs eicosapentaenoic and docosahexaenoic acids were determined in plasma through gas chromatography-flame ionization detection in 5,697 MESA participants. Cox proportional hazards regression evaluated the association between NEFA levels and incident type 2 diabetes and whether plasma n-3 FAs modified this association adjusting for age, sex, race, education, field center, smoking, and alcohol use.

RESULTS

Over a mean 11.4 years of the study period, higher diabetes incidence was found across successive NEFA quartiles (Q) (hazard ratio [95% CI]): Q1, 1.0; Q2, 1.35 (1.07, 1.71); Q3, 1.58 (1.24, 2.00); and Q4, 1.86 (1.45, 2.38) (P(trend) < 0.001). A significant interaction of n-3 FAs on the relation between NEFAs and type 2 diabetes was also observed (P(interaction) = 0.03). For individuals with lower n-3 levels (<75th percentile), a higher risk of type 2 diabetes was observed across quartiles of NEFAs: Q1, 1.0; Q2, 1.41 (1.07, 1.84); Q3, 1.77 (1.35, 2.31); and Q4, 2.18 (1.65, 2.88) (P(trend) < 0.001). No significant associations were observed in those with n-3 FAs ≥ 75th percentile (P(trend) = 0.54).

CONCLUSIONS

NEFAs are a marker of type 2 diabetes and may have clinical utility for detecting risk of its development. The modifying influence of n-3 FAs suggests a protective effect against disease and/or metabolic dysfunction related to NEFAs and requires further study.

The Role of MicroRNAs in Diabetic Complications-Special Emphasis on Wound Healing

Overweight and obesity are major problems in today’s society, driving the prevalence of diabetes and its related complications. It is important to understand the molecular mechanisms underlying the chronic complications in diabetes in order to develop better therapeutic approaches for these conditions. Some of the most important complications include macrovascular abnormalities, e.g., heart disease and atherosclerosis, and microvascular abnormalities, e.g., retinopathy, nephropathy and neuropathy, in particular diabetic foot ulceration. The highly conserved endogenous small non-coding RNA molecules, the micro RNAs (miRNAs) have in recent years been found to be involved in a number of biological processes, including the pathogenesis of disease. Their main function is to regulate post-transcriptional gene expression by binding to their target messenger RNAs (mRNAs), leading to mRNA degradation, suppression of translation or even gene activation. These molecules are promising therapeutic targets and demonstrate great potential as diagnostic biomarkers for disease. This review aims to describe the most recent findings regarding the important roles of miRNAs in diabetes and its complications, with special attention given to the different phases of diabetic wound healing.

Recent advances on the development of wound dressings for diabetic foot ulcer treatment--a review

Diabetic foot ulcers (DFUs) are a chronic, non-healing complication of diabetes that lead to high hospital costs and, in extreme cases, to amputation. Diabetic neuropathy, peripheral vascular disease, abnormal cellular and cytokine/chemokine activity are among the main factors that hinder diabetic wound repair. DFUs represent a current and important challenge in the development of novel and efficient wound dressings. In general, an ideal wound dressing should provide a moist wound environment, offer protection from secondary infections, remove wound exudate and promote tissue regeneration. However, no existing dressing fulfills all the requirements associated with DFU treatment and the choice of the correct dressing depends on the wound type and stage, injury extension, patient condition and the tissues involved. Currently, there are different types of commercially available wound dressings that can be used for DFU treatment which differ on their application modes, materials, shape and on the methods employed for production. Dressing materials can include natural, modified and synthetic polymers, as well as their mixtures or combinations, processed in the form of films, foams, hydrocolloids and hydrogels. Moreover, wound dressings may be employed as medicated systems, through the delivery of healing enhancers and therapeutic substances (drugs, growth factors, peptides, stem cells and/or other bioactive substances). This work reviews the state of the art and the most recent advances in the development of wound dressings for DFU treatment. Special emphasis is given to systems employing new polymeric biomaterials, and to the latest and innovative therapeutic strategies and delivery approaches.

Resistin and cardiovascular disease

Resistin has been implicated in coronary atherosclerotic disease and congestive heart failure. Recent studies have extended its involvement in peripheral artery disease. Despite some controversial data, the mainstream clinical literature supports that resistin is associated with both coronary and peripheral artery diseases including ischemic stroke. In this review, the multiple roles of resistin as screening, diagnostic, and prognostic marker for cardiovascular disease are discussed. The independence of resistin in disease prediction and diagnosis appears complicated by its confounders, such as C-reactive protein. A clear-cut biomarker function of resistin in cardiovascular disease needs be clarified by additional large-scale, well-designed prospective studies.

Time-dependent alterations in rat macrovessels with type 1 diabetes

Vascular complications are associated with the progressive severity of diabetes, resulting in significant morbidity and mortality. This study quantifies functional vascular parameters and macrovascular structure in a rat model of type 1 diabetes. While there was no difference in the systemic arterial elastance (Ea) with 50 days of diabetes, changes were noted in the aorta and femoral artery including increased tunica media extracellular matrix content, decreased width of both the media and individual smooth muscle cell layers, and increased incidence of damaged mitochondria. Extracellular matrix proteins and elastin levels were significantly greater in the aorta of diabetic animals. These differences correlated with diminished matrix metalloprotease activity in the aorta of the diabetic animals. In conclusion, diabetes significantly altered the structure and ultrastructure of the aorta and femoral artery before systemic changes in arterial elastance could be detected.