Leukocyte-endothelial interaction is augmented by high glucose concentrations and hyperglycemia in a NF-kB-dependent fashion

Low-level laser irradiation modifies the effect of hyperglycemia on adhesion molecule levels

Endothelium plays a key role in maintaining vascular homeostasis by secreting active factors involved in many biological processes such as hemostasis, angiogenesis, and inflammation. Hyperglycemia in diabetic patients causes dysfunction of endothelial cells. Soluble fractions of adhesion molecules like sE-selectin and vascular cell adhesion molecule (sVCAM) are considered as markers of endothelial damage. The low-level laser therapy (LLLT) effectively supports the conventional treatment of vascular complications in diabetes, for example hard-to-heal wounds in patients with diabetic foot syndrome. The aim of our study was to evaluate the effect of low-energy laser at the wavelength of 635 nm (visible light) and 830 nm (infrared) on the concentration of adhesion molecules: sE-selectin and sVCAM in the supernatant of endothelial cell culture of HUVEC line. Cells were cultured under high-glucose conditions of 30 mM/L. We have found an increase in sE-selectin and sVCAM levels in the supernatant of cells cultured under hyperglycemic conditions. This fact confirms detrimental influence of hyperglycemia on vascular endothelial cell cultures. LLLT can modulate the inflammation process. It leads to a decrease in sE-selectin and sVCAM concentration in the supernatant and an increase in the number of endothelial cells cultured under hyperglycemic conditions. The influence of LLLT is greater at the wavelength of 830 nm.

Endothelium as a Potential Target for Treatment of Abdominal Aortic Aneurysm

Abdominal aortic aneurysm (AAA) was previously ascribed to weaken defective medial arterial/adventitial layers, for example, smooth muscle/fibroblast cells. Therefore, besides surgical repair, medications targeting the medial layer to strengthen the aortic wall are the most feasible treatment strategy for AAA. However, so far, it is unclear whether such drugs have any beneficial effect on AAA prognosis, rate of aneurysm growth, rupture, or survival. Notably, clinical studies have shown that AAA is highly associated with endothelial dysfunction in the aged population. Additionally, animal models of endothelial dysfunction and endothelial nitric oxide synthase (eNOS) uncoupling had a very high rate of AAA formation, indicating there is crucial involvement of the endothelium and a possible pharmacological solution targeting the endothelium in AAA treatment. Endothelial cells have been found to trigger vascular wall remodeling by releasing proteases, or recruiting macrophages along with other neutrophils, into the medial layer. Moreover, inflammation and oxidative stress of the arterial wall were induced by endothelial dysfunction. Interestingly, there is a paradoxical differential correlation between diabetes and aneurysm formation in retinal capillaries and the aorta. Deciphering the significance of such a difference may explain current unsuccessful AAA medications and offer a solution to this treatment challenge. It is now believed that AAA and atherosclerosis are two separate but related diseases, based on their different clinical patterns which have further complicated the puzzle. Therefore, a thorough investigation of the interaction between endothelium and medial/adventitial layer may provide us a better understanding and new perspective on AAA formation, especially after taking into account the importance of endothelium in the development of AAA. Moreover, a novel medication strategy replacing the currently used, but suboptimal treatments for AAA, could be informed with this analysis.

Signaling between pancreatic β cells and macrophages via S100 calcium-binding protein A8 exacerbates β-cell apoptosis and islet inflammation

Chronic low-grade inflammation in the pancreatic islets is observed in individuals with type 2 diabetes, and macrophage levels are elevated in the islets of these individuals. However, the molecular mechanisms underlying the interactions between the pancreatic β cells and macrophages and their involvement in inflammation are not fully understood. Here, we investigated the role of S100 calcium-binding protein A8 (S100A8), a member of the damage-associated molecular pattern molecules (DAMPs), in β-cell inflammation. Co-cultivation of pancreatic islets with unstimulated peritoneal macrophages in the presence of palmitate (to induce lipotoxicity) and high glucose (to induce glucotoxicity) synergistically increased the expression and release of islet-produced S100A8 in a Toll-like receptor 4 (TLR4)-independent manner. Consistently, a significant increase in the expression of the S100a8 gene was observed in the islets of diabetic db/db mice. Furthermore, the islet-derived S100A8 induced TLR4-mediated inflammatory cytokine production by migrating macrophages. When human islet cells were co-cultured with U937 human monocyte cells, the palmitate treatment up-regulated S100A8 expression. This S100A8-mediated interaction between islets and macrophages evoked β-cell apoptosis, which was ameliorated by TLR4 inhibition in the macrophages or S100A8 neutralization in the pancreatic islets. Of note, both glucotoxicity and lipotoxicity triggered S100A8 secretion from the pancreatic islets, which in turn promoted macrophage infiltration of the islets. Taken together, a positive feedback loop between islet-derived S100A8 and macrophages drives β-cell apoptosis and pancreatic islet inflammation. We conclude that developing therapeutic approaches to inhibit S100A8 may serve to prevent β-cell loss in patients with diabetes.

Synergistic and non-synergistic effects of salmon calcitonin and omega - 3 fatty acids on antioxidant, anti-inflammatory, and haematological indices in diabetic rats

The optimum therapy for the management of diabetes mellitus (DM) has been a controversial issue. Therefore, the study investigated the effects of salmon calcitonin (Sct) and/or omega-3 fatty acids {eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA); EPA/DHA ratio?=?3/2} relative to metformin in diabetic male Wistar rats. Forty rats were used for this study. They were randomly divided into 8 groups of five (5) rats each, which were treated with single or combined administration of salmon calcitonin, N-3 and metformin. DM was induced by the administration of streptozotocin (65?mg/kg b.w., i.p.), 15?min after the administration of nicotinamide (110?mg/kg b.w., i.p.). Nine days afterwards, treatments started, and they lasted for 28 days. Sct was administered at 2.5 and 5.0 IU/kg b.w./day (i.m.), while, N-3 and metformin were administered at 200 and 180?mg/kg b.w./day (p.o.) respectively. The results showed that the induced DM significantly increased pro-inflammatory markers, and significantly altered antioxidant and haematological indices. The combined administration of Sct and N-3 had synergistic effects on total bilirubin and total antioxidant capacity, but, non-synergistic actions on malondialdehyde, uric acid, interleukin-6, lactate dehydrogenase, superoxide dismutase, catalase, glutathione peroxidase, and the haematological parameters. These effects were comparable to that of metformin which showed a more or less therapeutic action than N-3. The study concluded that the antioxidant, anti-inflammatory, and haematological effects of the combined administration of Sct and N-3 is comparable to that of metformin. Nevertheless, the latter showed more or less therapeutic effects relative to N-3.

Association of Hemorheology With High-Sensitivity Cardiac Troponin T Levels in Patients With Type 2 Diabetes Mellitus Assessed by Microchannel Array Flow Analyzer

Background

Recent studies on high-sensitivity cardiac troponin T (hs-cTnT) and whole blood passage time (WBPT), estimated by hemorheology assessed with the microchannel array flow analyzer (MC-FAN), have revealed the significance of cardiovascular risk factors. However, there are no known reports on the relationship between these two clinical parameters. This cross-sectional study aimed to clarify the associations between WBPT and hs-cTnT levels in patients with type 2 diabetes mellitus from the perspective of subclinical myocardial injury or the primary prevention of cardiovascular events.

Methods

A total of 301 outpatients (men, 116; women, 185; mean age, 65 ± 11 years), with no history of cardiovascular diseases, undergoing treatment for diabetes mellitus were enrolled. Hs-cTnT levels and WBPT were measured using a commercial device, and the relationship between hs-cTnT levels and various clinical parameters, including WBPT, was examined.

Results

Hs-cTnT levels were detected in 261 (86.7%) patients. WBPT was significantly higher in patients with detectable hs-cTnT levels than in those with undetectable hs-cTnT levels (64 ± 18 s vs. 51 ± 13 s, P < 0.001). In patients with detectable hs-cTnT levels, there was a significantly positive correlation between WBPT and hs-cTnT levels (r = 0.40; P < 0.001). Furthermore, multiple regression analysis revealed that WBPT (β = 0.24; P < 0.001) was an independent variable when hs-cTnT was a subordinate factor. Conversely, patients with high (≥ 70 s; odds ratio, 5.3 (95% CI, 1.6 - 16.1); P < 0.01) and median (50.2 - 69.8 s; odds ratio, 3.8 (95% CI, 1.2 - 12.4); P < 0.05) WBPT had a significantly higher risk for high hs-cTnT levels (≥ 0.014 ng/mL) than those with low WBPT (≤ 50.0 s).

Conclusions

The results of this study indicated independent associations of hemorheology with hs-cTnT in patients with type 2 diabetes mellitus assessed by MC-FAN. We suggest that an increase in hs-cTnT levels can be prevented by maintaining WBPT at ≤ 50.0 s.

Outcomes in patients with diabetes 10 years after liver transplantation

BACKGROUND

There are discrepancies between studies regarding the effect of diabetes mellitus on morbidity and mortality in patients undergoing liver transplantation. The aim of the present study was to compare mortality, risk of liver graft rejection, and cardiovascular events in patients with and without diabetes undergoing liver transplantation over a 10-year follow-up period.

METHODS

A retrospective study was performed on 183 patients who underwent liver transplantation in 2005 and 2006. Mortality and morbidity data were collected until 2016, including information on mortality and survival time, graft rejection and graft survival time, coronary heart disease, stroke, and peripheral arterial ischemia.

RESULTS

During the follow-up, 41.3% and 27.8% of patients in the groups with and without diabetes, respectively, died. A trend for lower survival time was observed in patients with diabetes, although this effect was not confirmed by the Cox regression model. There was an increased risk of graft rejection in the group with diabetes compared with the group without diabetes ( P  < 0.001). In the survival analysis, diabetes was associated with reduced graft survival time ( P  = 0.001). Cardiovascular events were also more likely in the group with diabetes ( P  = 0.005).

CONCLUSIONS

In the present study diabetes was associated with a higher risk of liver graft rejection and cardiovascular events. There was also a trend for higher mortality, although the effect was not statistically significant. These findings suggest that patients with diabetes require a more rigorous pretransplant evaluation and closer monitoring after transplantation in order to try to reduce associated complications.

Relationship Between Hemorheology Assessed Using Microchannel Array Flow Analyzer and Kidney Function in Hypertensive Patients

Background

Kidney function is known to be closely associated with the pathogenesis of hypertension. In contrast, hemorheology assessed using microchannel array flow analyzer (MC-FAN) has demonstrated the significance of cardiovascular risk factors in recent clinical studies. The present cross-sectional study aimed to clarify the relationship between hemorheology assessed by MC-FAN and kidney function in hypertensive patients from the perspective of primary prevention of cardiovascular events.

Methods

In total, 453 outpatients undergoing treatment for hypertension (176 men and 277 women; mean age ± standard deviation: 65 ± 13 years) with no history of cardiovascular disease were enrolled. Whole blood passage time (WBPT) was measured using MC-FAN as a marker of hemorheology, and the relationships with various clinical parameters including kidney function were examined.

Results

A significant correlation was observed between WBPT and the parameters of kidney function such as estimated glomerular filtration rate (r = -0.14, P < 0.01), urinary albumin excretion (r = 0.40, P < 0.001), and renal resistive index (r = 0.44, P < 0.001). Furthermore, multivariate analysis demonstrated urinary albumin excretion, renal resistive index, skin autofluorescence, derivatives of reactive oxygen metabolites, and hematocrit as independent variables for WBPT as a subordinate factor.

Conclusions

The results of the present study indicate that hemorheology assessed by the MC-FAN is significantly associated with markers of kidney function, such as albuminuria and increased renovascular resistance, in hypertensive patients.

Disease drivers of aging

It has long been known that aging, at both the cellular and organismal levels, contributes to the development and progression of the pathology of many chronic diseases. However, much less research has examined the inverse relationship-the contribution of chronic diseases and their treatments to the progression of aging-related phenotypes. Here, we discuss the impact of three chronic diseases (cancer, HIV/AIDS, and diabetes) and their treatments on aging, putative mechanisms by which these effects are mediated, and the open questions and future research directions required to understand the relationships between these diseases and aging.

Comparative study of cardio-protective effects of zinc oxide nanoparticles and zinc sulfate in streptozotocin-induced diabetic rats

The cardio-protective effects of zinc oxide nanoparticles (Zn NPs) against diabetes-induced cardiopathy were evaluated and compared with zinc sulfate (ZnSO₄). A total of 120 Wistar rats were randomly categorized as healthy and diabetic groups. Then, the 2 groups were classified in 5 subgroups. The animals received oral supplementations containing different Zn NP (ie, doses of 1, 3, and 10mg/kg) and ZnSO₄ (30mg/kg) concentrations over 8 weeks. Blood and cardiac tissue samples were collected in the different time intervals and subjected to biochemical and histopathological analysis. Zn NPs showed dual effects, as its middle dose played protective role and recovered cardiac damages evidenced by significant reduction of serum cholesterol, HDL-cholesterol, lipoprotein (a), atherogenic index, TNF-α, cardiac MDA, B-type natriuretic peptide and caspase-3 activity. Apoptosis indices and histopathological features also were improved. However, the highest dose was found to be toxic and resulted in aggravation of the injuries. Another interesting finding is the ability of the higher doses of Zn-NPs (3 and 10mg/kg) to elevate cardiac zinc levels above the normal range in healthy animal. ZnSO₄ also helped to recuperation of the damages, but the middle dose of Zn NPs was more efficient as compared to ZnSO₄. Conclusively, Zn NPs have the potential for Zn delivery in diabetic patients.

Impact of Hemorheology Assessed by the Microchannel Method on Pulsatility Index of the Common Carotid Artery in Patients With Type 2 Diabetes Mellitus

Background

Type 2 diabetes mellitus is known to be closely associated with the risk of ischemic stroke. Recent clinical studies have reported that a high pulsatility index (PI) of the cerebral or carotid artery, which is estimated by ultrasonography, also reflects a risk of ischemic stroke. This cross-sectional study aimed to clarify the impact of hemorheology assessed by the microchannel method on the PI of the common carotid artery (CCA) in patients with type 2 diabetes mellitus in terms of the primary prevention of ischemic stroke.

Methods

In total, 349 outpatients on treatment for type 2 diabetes mellitus (131 men and 218 women; mean age ± standard deviation: 65 ± 11 years) with no history of cardiovascular events, including ischemic stroke, were enrolled. The whole blood passage time (WBPT) as a marker of hemorheology and the PI of CCA were measured using commercial devices, and their relationships to various clinical parameters were examined.

Results

A significant positive correlation was observed between WBPT and the PI of CCA (r = 0.49, P < 0.001). Furthermore, multivariate analysis revealed that patients with high WBPT (≥70 s) had significantly higher risk (odds ratio: 5.2; 95% confidence interval: 2.4 - 9.2; P < 0.001) of being detected with a high PI of CCA (≥ 2) than those with low WBPT (≤ 52.0 s).

Conclusion

The results of this study indicated that WBPT was an important determination factor for the PI of CCA, suggesting that an increase in WBPT can potentially predict the incidence of ischemic stroke in patients with type 2 diabetes mellitus.

Relationship between cardiovascular risk factors and hemorheology assessed by microchannel method in patients with type 2 diabetes mellitus

Aim

In addition to atherosclerosis, impairment of blood rheology is an important factor in cardiovascular events. The present study attempted to clarify the relationship between hemorheology and cardiovascular risk factors in patients with type 2 diabetes mellitus assessed by a microchannel method.

Methods

We enrolled 294 patients with type 2 diabetes mellitus (109 males and 185 females; mean age, 69 ± 11 years) with no history of cardiovascular events. Hemorheology was evaluated with a microchannel array flow analyzer, and the relationship between whole-blood passage time (WBPT) and various clinical parameters was examined.

Results

WBPT was significantly correlated with advanced glycation end-product (AGE) levels at the skin (r = 0.49, p < 0.001), serum reactive oxygen metabolite concentrations (oxidative stress markers) (r = 0.25, p < 0.001), the cardio-ankle vascular index (CAVI, arterial function marker) (r = 0.32, p < 0.001), and a number of classical cardiovascular risk factors in an individual (r = 0.45, p < 0.001). Multiple regression analysis revealed that these factors were selected as independent variables for WBPT as a subordinate factor.

Conclusion

Hemorheology is significantly associated with novel cardiovascular risk factors, such as AGEs, in vivo oxidative stress, and CAVI, and clustering of classical cardiovascular risk factors in patients with type 2 diabetes mellitus.

Advanced Glycation End Products Inhibit the Proliferation of Human Umbilical Vein Endothelial Cells by Inhibiting Cathepsin D

We aimed to investigate the effect of advanced glycation end products (AGEs) on the proliferation and migration ability of human umbilical vein endothelial cells (HUVECs). Cell proliferation was detected by methyl thiazolyl tetrazolium (MTT) assay, real-time cell analyzer and 5-Ethynyl-2′-deoxyuridine (EdU) staining. Cell migration was detected by wound-healing and transwell assay. AGEs significantly inhibited the proliferation and migration of HUVECs in a time-and dose-dependent way. Western blotting revealed that AGEs dramatically increased the expression of microtubule-associated protein 1 light chain 3 (LC3) II/I and p62. Immunofluorescence of p62 and acridine orange staining revealed that AGEs significantly increased the expression of p62 and the accumulation of autophagic vacuoles, respectively. Chloroquine (CQ) could further promote the expression of LC3 II/I and p62, increase the accumulation of autophagic vacuoles and promote cell injury induced by AGEs. In addition, AGEs reduced cathepsin D (CTSD) expression in a time-dependent way. Overexpression of wild-type CTSD significantly decreased the ratio of LC 3 II/I as well as p62 accumulation induced by AGEs, but overexpression of catalytically inactive mutant CTSD had no such effects. Only overexpression of wild-type CTSD could restore the proliferation of HUVECs inhibited by AGEs. However, overexpression of both wild-type CTSD and catalytically inactive mutant CTSD could promote the migration of HUVECs inhibited by AGEs. Collectively, our study found that AGEs inhibited the proliferation and migration in HUVECs and promoted autophagic flux, which in turn played a protective role against AGEs-induced cell injury. CTSD, in need of its catalytic activity, may promote proliferation in AGEs-treated HUVECs independent of the autophagy-lysosome pathway. Meanwhile, CTSD could improve the migration of AGEs-treated HUVECs regardless of its enzymatic activity.

Effect of pregabalin administration upon reperfusion in a rat model of hyperglycemic stroke: Mechanistic insights associated with high-mobility group box 1

Hyperglycemia, which reduces the efficacy of treatments and worsens clinical outcomes, is common in stroke. Ability of pregabalin to reduce neuroexcitotoxicity may provide protection against stroke, even under hyperglycemia. We investigated its protective effect against hyperglycemic stroke and its possible molecular mechanisms. Male Wistar rats administered dextrose to cause hyperglycemia, underwent middle cerebral artery occlusion for 1 h and subsequent reperfusion. Rats were treated with an intraperitoneal injection of 30 mg/kg pregabalin or an equal amount of normal saline at the onset of reperfusion (n = 16 per group). At 24 h after reperfusion, neurological deficit, infarct volume, and apoptotic cell count were assessed. Western blot analysis was performed to determine protein expression of high-mobility group box 1 (HMGB1), toll-like receptor-4 (TLR-4), phosphorylated nuclear factor-kappa B (p-NF-κB), interleukin-1beta (IL-1β), tumor necrosis factor-alpha (TNF-α), phosphorylated inducible and endothelial nitric oxide synthase (p-iNOS, p-eNOS), Bcl-2, Bax, Cytochrome C, and caspase-3 in the brain. Pregabalin-treated rats showed significantly improved neurological function (31% decrease in score), reduced infarct size (by 33%), fewer apoptotic cells (by 63%), and lower expression levels of HMGB1, TLR4, p-NF-κB, IL-1β, and TNF- α, compared with control rats. Decreased p-iNOS and increased p-eNOS expressions were also observed. Expression of Bax, Cytochrome C, and cleaved caspase-3/caspase3 was significantly downregulated, while Bcl-2 expression was increased by pregabalin treatment. Pregabalin administration upon reperfusion decreased neuronal death and improved neurological function in hyperglycemic stroke rats. Cogent mechanisms would include attenuation of HMGB1/TLR-4-mediated inflammation and favorable modulation of the NOS.

Small Ubiquitin-Like Modifier 4 (SUMO4) Gene M55V Polymorphism and Type 2 Diabetes Mellitus: A Meta-analysis Including 6,823 Subjects

BACKGROUND

Many studies suggest that the small ubiquitin-like modifier 4 (SUMO4) M55V gene polymorphism (rs237025) may be associated with an increased risk of type 2 diabetes mellitus (T2DM). However, due to other conflicting results, a clear consensus is lacking in the matter.

OBJECTIVE AND METHODS

A meta-analysis consisting of 6,823 subjects from 10 studies was conducted to elucidate relationship between the SUMO4 M55V gene polymorphism and T2DM. Depending on the heterogeneity of the data, either a fixed or random-effects model would be used to assess the combined odds ratio (ORs) and their corresponding 95% confidence interval (CI).

RESULTS

SUMO4 gene M55V polymorphism was significantly associated with T2DM in the whole population under allelic (OR: 1.18, 95% CI: 1.10-1.28, P = 1.63 × 10^-5), recessive (OR: 1.59, 95% CI: 1.14-2.23, P = 0.006), dominant (OR: 0.815, 95% CI: 0.737-0.901, P = 6.89 × 10^-5), homozygous (OR: 1.415, 95% CI: 1.170-1.710, P = 0.0003), heterozygous (OR: 1.191, 95% CI: 1.072-1.323, P = 0.001), and additive genetic models (OR: 1.184, 95% CI: 1.097-1.279, P = 1.63 × 10^-5). In our subgroup analysis, a significant association was found again in the Chinese population, but not in Japanese or Iranian population.

CONCLUSION

SUMO4 gene M55V polymorphism may correlate with increased T2DM risk. Chinese carriers of the V allele of the SUMO4 gene M55V polymorphism may be predisposed to developing T2DM.

miR-15a/16 reduces retinal leukostasis through decreased pro-inflammatory signaling

Background

Hyperglycemia is a significant risk factor for diabetic retinopathy and induces increased inflammatory responses and retinal leukostasis, as well as vascular damage. Although there is an increasing amount of evidence that miRNA may be involved in the regulation in the pathology of diabetic retinopathy, the mechanisms by which miRNA mediate cellular responses to control onset and progression of diabetic retinopathy are still unclear. The purpose of our study was to investigate the hypothesis that miR-15a/16 inhibit pro-inflammatory signaling to reduce retinal leukostasis.

Methods

We generated conditional knockout mice in which miR-15a/16 are eliminated in vascular endothelial cells. For the in vitro work, human retinal endothelial cells (REC) were cultured in normal (5 mM) glucose or transferred to high glucose medium (25 mM) for 3 days. Transfection was performed on REC in high glucose with miRNA mimic (hsa-miR-15a-5p, hsa-miR-16-5p). Statistical analyses were done using unpaired Student t test with two-tailed p value. p < 0.05 was considered significant. Data are presented as mean ± SEM.

Results

We demonstrated that high glucose conditions decreased expression of miR-15a/16 in cultured REC. Overexpression of miR-15a/16 with the mimic significantly decreased pro-inflammatory signaling of IL-1β, TNFα, and NF-κB in REC. In vivo data demonstrated that the loss of miR-15a/16 in vascular cells led to increased retinal leukostasis and CD45 levels, together with upregulated levels of IL-1β, TNFα, and NF-κB.

Conclusions

The data indicate that miR-15a/16 play significant roles in reducing retinal leukostasis, potentially through inhibition of inflammatory cellular signaling. Therefore, we suggest that miR-15a/16 offer a novel potential target for the inhibition of inflammatory mediators in diabetic retinopathy.

Electronic supplementary material

The online version of this article (doi:10.1186/s12974-016-0771-8) contains supplementary material, which is available to authorized users.

Pharmacodynamics, pharmacokinetics and clinical efficacy of phosphodiesterase-5 inhibitors

INTRODUCTION

Phosphodiesterase type 5 inhibitors (PDE5Is) are the first-line drugs in the management of erectile dysfunction (ED). However, over the past two decades tremendous efforts have been made to identify new clinical uses of PDE5Is beyond their roles in ED. Areas covered: Basic science articles, clinical trials, reviews, and meta-analysis published between 1996 and 2015 were searched using MEDLINE (PubMed interface) to collect the most relevant and impactful studies from our perspectives as practicing urologists. This review mainly focuses on the level one evidence-based clinical efficacy and drug-related toxicity of oral PDE5Is. In addition, drug discovery, pharmacokinetics and pharmacodynamics, potential use in other diseases, and future directions are discussed. Expert opinion: On-demand PED5Is for the treatment of ED has shifted toward chronic administration in a broad spectrum of conditions that are thought to be associated with endovascular health. Several studies have shown that PDE5Is may play a cardioprotective or neuroprotective role. Further studies are under way to verify beneficial effects of PDE5I in non-urological conditions.

Sustained elevation of NF-κB activity sensitizes offspring of maternal inflammation to hypertension via impairing PGC-1α recovery

Growing evidence has demonstrated that maternal detrimental factors, including inflammation, contribute to the development of hypertension in the offspring. The current study found that offspring subjected to prenatal exposure of inflammation by lipopolysaccharide (LPS) challenge during the second semester showed significantly increased systolic blood pressure. In addition, these offspring also displayed augmented vascular damage and reactive oxygen species (ROS) levels in thoracic aortas when challenged with deoxycorticosterone acetate and high-salt diet (DOCA-salt). Interestingly, the antioxidant N-acetyl-L-cysteine markedly reversed these changes. Mechanistically, prenatal LPS exposure led to pre-existing elevated peroxisome proliferators-activated receptor-γ co-activator (PGC)-1α, a critical master of ROS metabolism, which up-regulated the ROS defense capacity and maintained the balance of ROS generation and elimination under resting state. However, continued elevation of NF-κB activity significantly suppressed the rapid recovery of PGC-1α expression response to DOCA-salt challenge in offspring that underwent prenatal inflammatory stimulation. This was further confirmed by using a NF-κB inhibitor (N-p-Tosyl-L-phenylalanine chloromethyl ketone) that restored PGC-1α recovery and prevented blood pressure elevation induced by DOCA-salt. Our results suggest that maternal inflammation programmed proneness to NF-κB over-activation which impaired PGC-1α-mediated anti-oxidant capacity resulting in the increased sensitivity of offspring to hypertensive damage.

The Levels of Soluble Adhesion Molecules in Diabetic and Nondiabetic Patients with Combined Hyperlipoproteinemia and the Effect of Ciprofibrate Therapy

Cell adhesion molecules are thought to play a role in atherosclerosis. Several clinical trials have shown that fibrate treatment leads to a reduction in coronary events, although the mechanisms are not fully understood. Soluble vascular cell adhesion molecule-1 (sVCAM-1), soluble intercellular adhesion molecule-1 (sICAM-1) and soluble E-selectin plasma concentrations were measured in 10 obese dyslipidemic men (group A), in 10 obese dyslipidemic type 2 diabetic men without coronary artery disease (CAD) (group B), and in 10 dyslipidemic type 2 diabetic men with angiographically documented CAD (group C) before and after 12 weeks of treatment with ciprofibrate. Compared with nondiabetic dyslipidemic men, diabetic patients with CAD or without documented CAD had significantly increased levels of sVCAM-1 (512 ±39 versus 750 ±139 ng/mL; p<0.0001 and 566 ±78 ng/mL; p<0.01, respectively) and sE-selectin (54.8 ±6.9 versus 65.9 ±8.8 ng/mL; p<0.001 and 62.6 ±9.4 ng/mL; p=0.056, respectively). The levels of sICAM-1 were similar in all 3 groups. Multivariate analyses showed that the higher sCAM levels in patients occurred independently of lipoprotein levels. Waist circumference as a marker of abdominal adiposity was the only independent predictor of elevated concentrations of all 3 cell adhesion molecules in multivariate analyses. sE-selectin was associated with HbA1C levels (p<0.01) in diabetic men at baseline. After 12 weeks of ciprofibrate therapy, sVCAM-1 levels were reduced by 13.5 ±2.1%, sICAM-1 levels by 11.8 ±2.2%, and sE-selectin levels by 17.1 ±3.5% (p<0.01 for all) with the greatest sE-selectin reduction in the diabetic subgroups (p<0.001). There was no correlation between the lowering of soluble adhesion molecules and the magnitude of lipid-lowering effect. An increased level of circulating adhesion molecules may be a mechanism by which dyslipidemia and/or diabetes mellitus promotes atherogenesis, and treatment with ciprofibrate may alter vascular cell activation.

Association of diabetes and diabetes treatment with the host response in critically ill sepsis patients

Background

Diabetes is associated with chronic inflammation and activation of the vascular endothelium and the coagulation system, which in a more acute manner are also observed in sepsis. Insulin and metformin exert immune modulatory effects. In this study, we aimed to determine the association of diabetes and preadmission insulin and metformin use with sepsis outcome and host response.

Methods

We evaluated 1104 patients with sepsis, admitted to the intensive care unit and stratified according to the presence or absence of diabetes mellitus. The host response was examined by a targeted approach (by measuring 15 plasma biomarkers reflective of pathways implicated in sepsis pathogenesis) and an unbiased approach (by analyzing whole genome expression profiles in blood leukocytes).

Results

Diabetes mellitus was not associated with differences in sepsis presentation or mortality up to 90 days after admission. Plasma biomarker measurements revealed signs of systemic inflammation, and strong endothelial and coagulation activation in patients with sepsis, none of which were altered in those with diabetes. Patients with and without diabetes mellitus, who had sepsis demonstrated similar transcriptional alterations, comprising 74 % of the expressed gene content and involving over-expression of genes associated with pro-inflammatory, anti-inflammatory, Toll-like receptor and metabolic signaling pathways and under-expression of genes associated with T cell signaling pathways. Amongst patients with diabetes mellitus and sepsis, preadmission treatment with insulin or metformin was not associated with an altered sepsis outcome or host response.

Conclusions

Neither diabetes mellitus nor preadmission insulin or metformin use are associated with altered disease presentation, outcome or host response in patients with sepsis requiring intensive care.

Electronic supplementary material

The online version of this article (doi:10.1186/s13054-016-1429-8) contains supplementary material, which is available to authorized users.

The protective effect of daidzein on high glucose-induced oxidative stress in human umbilical vein endothelial cells

Endothelial cell dysfunction is considered a major cause of vascular complications in diabetes. In the present study, we investigated the protective effect of daidzein, a natural isoflavonoid, against high-glucose-induced oxidative damage in human umbilical vein endothelial cells (HUVECs). Treatment with a high concentration of glucose (30 mM) induced oxidative stress in the endothelial cells, against which daidzein protected the cells as demonstrated by significantly increased cell viability. In addition, lipid peroxidation, intracellular reactive oxygen species (ROS) generation, and indirect nitric oxide levels induced by the high glucose treatment were significantly reduced in the presence of daidzein (0.02-0.1 mM) in a dose-dependent manner. High glucose levels induced the overexpression of inducible nitric oxide synthase (iNOS), cyclooxygenase-2 (COX-2), and NF-κB proteins in HUVECs, which was suppressed by treatment with 0.04 mM daidzein. These findings indicate the potential of daidzein to reduce high glucose-induced oxidative stress.

Baicalin, baicalein and wogonin inhibits high glucose-induced vascular inflammation in vitro and in vivo

Vascular inflammatory process has been suggested to play a key role in initiation and progression of atherosclerosis, a major complication of diabetes mellitus. Thus, in this study, we attempted to determine whether three structurally related polyphenols found in the Chinese herb Huang Qui, namely baicalin, baicalein, and wogonin, can suppress vascular inflammatory processes induced by high glucose (HG) in human umbilical vein endothelial cells (HUVECs) and mice. Data showed that HG induced markedly increased vascular permeability, monocyte adhesion, expressions of cell adhesion molecules (CAMs), formation of reactive oxygen species (ROS) and activation of nuclear factor (NF)-κB. Remarkably, all of the above mentioned vascular inflammatory effects of HG were attenuated by pretreatment with baicalin, baicalein, and wogonin. Vascular inflammatory responses induced by HG are critical events underlying development of various diabetic complications, therefore, our results suggest that baicalin, baicalein, and wogonin may have significant therapeutic benefits against diabetic complications and atherosclerosis.

Myeloid thrombomodulin lectin-like domain inhibits osteoclastogenesis and inflammatory bone loss

Osteoclastogenesis is an essential process during bone metabolism which can also be promoted by inflammatory signals. Thrombomodulin (TM), a transmembrane glycoprotein, exerts anti-inflammatory activities such as neutralization of proinflammatory high-mobility group box 1 (HMGB1) through TM lectin-like domain. This study aimed to identify the role of myeloid TM (i.e., endogenous TM expression on the myeloid lineage) in osteoclastogenesis and inflammatory bone loss. Using human peripheral blood mononuclear cells and mouse bone marrow-derived macrophages, we observed that the protein levels of TM were dramatically reduced as these cells differentiated into osteoclasts. In addition, osteoclastogenesis and extracellular HMGB1 accumulation were enhanced in primary cultured monocytes from myeloid-specific TM-deficient mice (LysMcre/TM^flox/flox) and from TM lectin-like domain deleted mice (TM^LeD/LeD) compared with their respective controls. Micro-computerized tomography scans showed that ovariectomy-induced bone loss was more pronounced in TM^LeD/LeD mice compared with controls. Finally, the inhibiting effects of recombinant TM lectin-like domain (rTMD1) on bone resorption in vitro, and bone loss in both the ovariectomized model and collagen antibody-induced arthritis model has been detected. These findings suggested that the myeloid TM lectin-like domain may inhibit osteoclastogenesis by reducing HMGB1 signaling, and rTMD1 may hold therapeutic potential for inflammatory bone loss.

Alu RNA accumulation in hyperglycemia augments oxidative stress and impairs eNOS and SOD2 expression in endothelial cells

Endothelial dysfunction resulting from oxidative stress and inflammation plays a dominant role in hyperglycemia-induced vasculopathy. While double-stranded RNA (dsRNA) accumulates in redox and inflammatory conditions, its precise role in hyperglycemia-associated endothelial dysfunction remains unclear. This study aimed to investigate whether and how endogenous dsRNA contributes to endothelial dysfunction via oxidative stress. We used a dsRNA-specific antibody J2 to detect and immunoprecipitate cellular dsRNA. Acquired dsRNA was recognized by cDNA library construction and DNA sequencing. Quantitative PCR, ELISA and immunoassays were performed to identify changes induced by acquired dsRNA in primary human umbilical vein endothelial cells (HUVEC). Our data showed that endogenous dsRNA homologous to Alu Sc subfamily accumulated in hyperglycemic HUVEC. Comparing Alu-transfected HUVEC with high-glucose treated HUVEC, we found that Alu RNA elicited the production of reactive oxygen species (ROS) and up-regulated interleukin-1β (IL-1β) expression and secretion in a similar manner as high-glucose treatment. Moreover, Alu RNA impeded the expression of endothelial nitric oxide synthase (eNOS) and superoxide dismutase 2 (SOD2), increased ROS production and activated nuclear factor NFκB by chemically scavenging ROS and inactivation of NFκB. The repressed expression of eNOS and SOD2 resulted from Alu RNA-mediated negative regulatory mechanisms. Our study uncovered endogenous Alu RNA accumulation in hyperglycemic endothelial cells that provoked endothelial oxidative stress and dysfunction by suppressing SOD2 and eNOS expression at both transcription and translation levels via NFκB signaling pathway. These findings suggest a novel regulatory mechanism that involves endogenous dsRNA in endothelial oxidative stress and dysfunction.

Low-molecular-weight fractions of Alcalase hydrolyzed egg ovomucin extract exert anti-inflammatory activity in human dermal fibroblasts through the inhibition of tumor necrosis factor-mediated nuclear factor κB pathway

Ovomucin is a mucin-like protein from egg white with a variety of biological functions. We hypothesized that ovomucin-derived peptides might exert anti-inflammatory activity. The specific objectives were to test the anti-inflammatory activities of different ovomucin hydrolysates and its various fractions in human dermal fibroblasts, and to understand the possible molecular mechanisms. Three ovomucin hydrolysates were prepared and desalted; only the desalted Alcalase hydrolysate showed anti-inflammatory activity. Desalting of ovomucin hydrolysate enriched the proportion of low-molecular-weight (MW) peptides. Indeed, ultrafiltration of this hydrolysate displayed comparable anti-inflammatory activity in dermal fibroblasts, indicating the responsible role of low-MW bioactive peptides in exerting the beneficial biological function. The anti-inflammatory activity of low-MW peptides was regulated through the inhibition of tumor necrosis factor-mediated nuclear factor κ-light-chain-enhancer of activated B cells activity. Our study demonstrated that both peptide composition and MW distribution play important roles in anti-inflammatory activity. The low-MW fractions prepared from ovomucin Alcalase hydrolysate may have potential applications for maintenance of dermal health and treatment of skin diseases.

Vicenin-2 and scolymoside inhibit high-glucose-induced vascular inflammation in vitro and in vivo

The vascular inflammatory process has been suggested to play a key role in the initiation and progression of atherosclerosis, a major complication of diabetes mellitus. Thus, in this study, we attempted to determine whether 2 structurally related flavonoids found in Cyclopia subternata, vicenin-2 and scolymoside, can suppress high-glucose (HG)-induced vascular inflammatory processes in human umbilical vein endothelial cells (HUVECs) and mice. The effects of vicenin-2 and scolymoside on HG-induced vascular inflammation were determined by measuring vascular permeability, leukocyte adhesion and migration, cell adhesion molecule (CAM) expression levels, and reactive oxygen species (ROS) formation. In addition, the anti-inflammation mechanism was investigated using immunofluorescence staining and Western blotting. The data showed that HG markedly increased vascular permeability, monocyte adhesion, expression of CAMs, formation of reactive oxygen species (ROS), and activation of nuclear factor (NF)-κB. Remarkably, pretreatment with vicenin-2 and scolymoside attenuated all of the above-mentioned vascular inflammatory effects of HG. HG-induced vascular inflammatory responses are critical events underlying the development of various diabetic complications; therefore, our results suggest that vicenin-2 and scolymoside have significant therapeutic benefits against diabetic complications and atherosclerosis.

Glycemic Control in Coronary Revascularization

OPINION STATEMENT

Hyperglycemia in the setting of coronary revascularization is associated with increased adverse cardiovascular events in patients with or without diabetes mellitus. Data suggest that acute peri-procedural hyperglycemia causes an increase in inflammation, platelet activity, and endothelial dysfunction and is associated with plaque instability and infarct size. While peri-procedural blood glucose level is an independent predictor of adverse outcomes in patients undergoing coronary revascularization, treatment strategies remain uncertain. Randomized clinical trials of glucose-insulin-potassium infusions have consistently shown no benefit, while those comparing insulin therapy versus standard of care have demonstrated mixed results, likely due to the failure to reach euglycemia with these strategies. Although no glucose-lowering agent has been shown to be superior in peri-procedural glycemic control, the continuation of clinically prescribed long-acting glucose-lowering medications in patients with diabetes mellitus prior to coronary angiography and possible percutaneous coronary intervention may be the simplest and most effective approach to maintain euglycemia and decrease the associated increase in inflammation and platelet activity. However, alternative strategies such as therapies targeted at the underlying mechanism of harm (e.g., more potent anti-platelet therapy, anti-inflammatory therapy) should also be considered and warrant further investigation.

Vascular endothelial dysfunction and pharmacological treatment

The endothelium exerts multiple actions involving regulation of vascular permeability and tone, coagulation and fibrinolysis, inflammatory and immunological reactions and cell growth. Alterations of one or more such actions may cause vascular endothelial dysfunction. Different risk factors such as hypercholesterolemia, homocystinemia, hyperglycemia, hypertension, smoking, inflammation, and aging contribute to the development of endothelial dysfunction. Mechanisms underlying endothelial dysfunction are multiple, including impaired endothelium-derived vasodilators, enhanced endothelium-derived vasoconstrictors, over production of reactive oxygen species and reactive nitrogen species, activation of inflammatory and immune reactions, and imbalance of coagulation and fibrinolysis. Endothelial dysfunction occurs in many cardiovascular diseases, which involves different mechanisms, depending on specific risk factors affecting the disease. Among these mechanisms, a reduction in nitric oxide (NO) bioavailability plays a central role in the development of endothelial dysfunction because NO exerts diverse physiological actions, including vasodilation, anti-inflammation, antiplatelet, antiproliferation and antimigration. Experimental and clinical studies have demonstrated that a variety of currently used or investigational drugs, such as angiotensin-converting enzyme inhibitors, angiotensin AT1 receptors blockers, angiotensin-(1-7), antioxidants, beta-blockers, calcium channel blockers, endothelial NO synthase enhancers, phosphodiesterase 5 inhibitors, sphingosine-1-phosphate and statins, exert endothelial protective effects. Due to the difference in mechanisms of action, these drugs need to be used according to specific mechanisms underlying endothelial dysfunction of the disease.

Angiotensin 1-7 significantly reduces diabetes-induced leukocyte recruitment both in vivo and in vitro

OBJECTIVE

Recent studies have demonstrated that Ang1-7 has anti-inflammatory effects. Since the formation of Ang1-7 is significantly altered in the setting of diabetes, here we aimed to evaluate whether Ang1-7 infusion could ameliorate diabetes-induced leukocyte recruitment.

METHODS

Wild-type male Wistar rats were randomly allocated to the following groups: control + saline, control + Ang1-7, diabetes + saline, diabetes + Ang1-7. Diabetes was induced by streptozotocin. Saline and Ang1-7 (576 μg/kg/day) were injected intraperitoneally daily. After 4 weeks leukocyte trafficking was studied in vivo by intravital microscopy in the mesenteric bed, where the expression of pro-oxidative, proinflammatory, and profibrotic molecules was also assessed. In parallel in vitro studies, HUVEC were grown in 5 mM, 22 mM, 30 mM, 40 mM, 50 mM, and 75 mM glucose media for 48 h, 72 h and 6 days and were treated either with placebo, or with Ang1-7, or with Ang1-7 and its inhibitor A779 in order to evaluate the expression of ICAM-1 and VCAM-1. We further studied leukocytes recruitment in vitro by evaluating PMN-HUVEC adhesion.

RESULTS

Ang1-7 prevented in vivo diabetes-induced leukocyte adhesion and extravasation, and it significantly reduced vascular hypertrophy and the other molecular changes due to diabetes. Ang 1-7 prevented also in vitro the hyperglycemia-induced increase of ICAM-1 and VCAM-1 as well as the hyperglycemia-induced PMN adhesion. A779 inhibited Ang 1-7 effects.

CONCLUSIONS

Ang1-7 significantly reduced diabetes-induced leukocyte recruitment both in vivo and in vitro. These findings emphasize the potential utility of ACE2/Ang1-7/Mas repletion as a strategy to reduce diabetes-induced atherosclerosis.

Direct Endothelial Nitric Oxide Synthase Activation Provides Atheroprotection in Diabetes-Accelerated Atherosclerosis

Patients with diabetes have an increased risk of developing atherosclerosis. Endothelial dysfunction, characterized by the lowered bioavailability of endothelial NO synthase (eNOS)-derived NO, is a critical inducer of atherosclerosis. However, the protective aspect of eNOS in diabetes-associated atherosclerosis remains controversial, a likely consequence of its capacity to release both protective NO or deleterious oxygen radicals in normal and disease settings, respectively. Harnessing the atheroprotective activity of eNOS in diabetic settings remains elusive, in part due to the lack of endogenous eNOS-specific NO release activators. We have recently shown in vitro that eNOS-derived NO release can be increased by blocking its binding to Caveolin-1, the main coat protein of caveolae, using a highly specific peptide, CavNOxin. However, whether targeting eNOS using this peptide can attenuate diabetes-associated atherosclerosis is unknown. In this study, we show that CavNOxin can attenuate atherosclerotic burden by ∼84% in vivo. In contrast, mice lacking eNOS show resistance to CavNOxin treatment, indicating eNOS specificity. Mechanistically, CavNOxin lowered oxidative stress markers, inhibited the expression of proatherogenic mediators, and blocked leukocyte-endothelial interactions. These data are the first to show that endogenous eNOS activation can provide atheroprotection in diabetes and suggest that CavNOxin is a viable strategy for the development of antiatherosclerotic compounds.

Tang-Tong-Fang Confers Protection against Experimental Diabetic Peripheral Neuropathy by Reducing Inflammation

Tang-tong-fang (TTF) is a Chinese herbal formula that has been shown to be beneficial in diabetic peripheral neuropathy (DPN), a common complication secondary to diabetic microvascular injury. However, the underlying mechanism of protection in nerve ischemia provided by TTF is still unclear. We hypothesized that TTF alleviates DPN via inhibition of ICAM-1 expression. Therefore, we tested the effect of TTF in a previously established DPN model, in which nerve injury was induced by ischemia/reperfusion in streptozotocin-induced diabetic rats. We found that the conduction velocity and amplitude of action potentials of sciatic nerve conduction were reduced in the DPN model group but were rescued by TTF treatment. In addition, TTF treatment also attenuated the effect of DPN on other parameters including histology and ultrastructural changes, expression of ICAM-1, MPO, and TNF-α in rat sciatic nerves, and plasma sICAM-1 and MPO levels. Together, our data suggest that TTF treatment may alleviate DPN via ICAM-1 inhibition.

A review of therapies for diabetic macular oedema and rationale for combination therapy

Diabetic macular oedema (DMO) is responsible for significant visual impairment in diabetic patients. The primary cause of DMO is fluid leakage resulting from increased vascular permeability through contributory anatomical and biochemical changes. These include endothelial cell (EC) death or dysfunction, pericyte loss or dysfunction, thickened basement membrane, loss or dysfunction of glial cells, and loss/change of EC Glycocalyx. The molecular changes include increased reactive oxygen species, pro-inflammatory changes: advanced glycation end products, intracellular adhesion molecule-1, Complement 5-9 deposition and cytokines, which result in increased paracellular permeability, tight junction disruption, and increased transcellular permeability. Laser photocoagulation has been the mainstay of treatment until recently when pharmacological treatments were introduced. The current treatments for DMO target reducing vascular leak in the macula once it has occurred, they do not attempt to treat the underlying pathology. These pharmacological treatments are aimed at antagonising vascular endothelial growth factor (VEGF) or non-VEGF inflammatory pathways, and include intravitreal injections of anti-VEGFs (ranibizumab, aflibercept or bevacizumab) or steroids (fluocinolone, dexamethasone or triamcinolone) as single therapies. The available evidence suggests that each individual treatment modality in DMO does not result in a completely dry macula in most cases. The ideal treatment for DMO should improve vision and improve morphological changes in the macular (eg, reduce macular oedema) for a significant duration, reduced adverse events, reduced treatment burden and costs, and be well tolerated by patients. This review evaluates the individual treatments available as monotherapies, and discusses the rationale and potential for combination therapy in DMO. A comprehensive review of clinical trials related to DMO and their outcomes was completed. Where phase III randomised control trials were available, these were referenced, if not available, phase II trials have been included.

Current intravitreal pharmacologic therapies for diabetic macular edema

INTRODUCTION

Diabetic retinopathy is the leading cause of vision loss in working-age adults; it is a highly prevalent cause of vision loss overall and has a potent impact on the quality of life in those with diabetes mellitus and public health in general. Diabetic macular edema (DME) is the most common cause of vision loss from diabetic retinopathy. In patients with diabetes mellitus, chronic hyperglycemia leads to activation of the inflammatory cascade and retinal capillary damage that result in microaneurysm formation in the retina. In addition to the possibility of associated ischemia, microaneurysms are hyperpermeable; the resultant loss of the blood-retinal barrier leads to vision loss if consequent edema involves the center of the fovea. The standard of DME therapy for >25 years was focal laser photocoagulation applied to or near the microaneurysms. However, results from clinical trials of intravitreal vascular endothelial growth factor (VEGF) blockers and corticosteroids for the treatment of DME have led to a dramatic paradigm shift away from laser therapy to primary treatment with these pharmacologic agents.

METHODS

Medline literature search of approaches for treating DME.

RESULTS

Intravitreal pharmacologic treatments with anti-VEGF agents and corticosteroids have recently been shown to be superior to laser treatment of DME.

CONCLUSION

The existence of pharmacologic treatment of DME, shown to be superior to laser monotherapy, has created a seismic change in the approach of treatment of these patients. This review provides a summary of the therapies and the rationale regarding the current pharmacologic therapy of DME.

Liraglutide improves hypertension and metabolic perturbation in a rat model of polycystic ovarian syndrome

Polycystic ovarian syndrome (PCOS) is the most common endocrine disorder in women of reproductive age, with a prevalence of 5–8%. Type 2 diabetes and cardiovascular disease (CVD) are its long-term complications. Targeted therapies addressing both these complications together are lacking. Glucagon like peptide-1 (GLP-1) agonists that are used to treat type 2 diabetes mellitus have beneficial effects on the cardiovascular system. Hence we hypothesized that a GLP-1 agonist would improve both cardiovascular and metabolic outcomes in PCOS. To test this hypothesis, we used an established rat model of PCOS. Prepubertal female Sprague Dawley rats were sham-implanted or implanted s.c. with dihydrotestosterone (DHT) pellets (90 day release; 83μg/day). At 12 wks of age, sham implanted rats received saline injections and the DHT treated animals were administered either saline or liraglutide (0.2mg/kg s.c twice daily) for 4 weeks. Subgroups of rats were implanted with telemeters between 12-13 weeks of age to monitor blood pressure. DHT implanted rats had irregular estrus cycles and were significantly heavier than the control females at 12 weeks (mean± SEM 251.9±3.4 vs 216.8±3.4 respectively; p<0.05) and 4 weeks of treatment with liraglutide in DHT treated rats significantly decreased body weight (mean± SEM 294.75 ±3.2 in DHT+ saline vs 276.25±2.7 in DHT+ liraglutide group respectively; p<0.01). Liraglutide treatment in the DHT implanted rats significantly improved glucose excursion during oral glucose tolerance test (area under the curve: DHT+ saline 28674±310 vs 24990± 420 in DHT +liraglutide p <0.01). DHT rats were hypertensive and liraglutide treatment significantly improved mean arterial pressure. These results suggest that GLP-1 treatment could improve DHT–induced metabolic and blood pressure deficits associated with PCOS.

Cardiovascular effects of dipeptidyl peptidase-4 inhibitors in patients with type 2 diabetes

Cardiovascular (CV) disease is the leading cause of mortality and morbidity in patients with type 2 diabetes mellitus (T2DM). However, improving glycaemic control alone has not decreased CV events. Therapies that improve glycaemic control, CV disease risk factors and CV function are more likely to be successful. Dipeptidyl peptidase-4 (DPP-4) inhibitors prevent breakdown of incretin hormones glucagon-like peptide-1(GLP-1) and glucose-dependent insulinotropic peptide and improve glycaemic control in patients with T2DM. DPP-4 acts on other substrates, many associated with cardioprotection. Thus, inhibition of DPP-4 may lead to elevations in these potentially beneficial substrates. Data from animal studies and small observational studies in humans suggest that DPP-4 inhibitors may potentially reduce CV risk. However, recently completed CV outcome trials in patients with T2DM and CV disease or at high risk of adverse CV events have shown that the DPP-4 inhibitors saxagliptin and alogliptin neither increased nor decreased major adverse CV events.

Are reactive oxygen species still the basis for diabetic complications?

Despite the wealth of pre-clinical support for a role for reactive oxygen and nitrogen species (ROS/RNS) in the aetiology of diabetic complications, enthusiasm for antioxidant therapeutic approaches has been dampened by less favourable outcomes in large clinical trials. This has necessitated a re-evaluation of pre-clinical evidence and a more rational approach to antioxidant therapy. The present review considers current evidence, from both pre-clinical and clinical studies, to address the benefits of antioxidant therapy. The main focus of the present review is on the effects of direct targeting of ROS-producing enzymes, the bolstering of antioxidant defences and mechanisms to improve nitric oxide availability. Current evidence suggests that a more nuanced approach to antioxidant therapy is more likely to yield positive reductions in end-organ injury, with considerations required for the types of ROS/RNS involved, the timing and dosage of antioxidant therapy, and the selective targeting of cell populations. This is likely to influence future strategies to lessen the burden of diabetic complications such as diabetes-associated atherosclerosis, diabetic nephropathy and diabetic retinopathy.

Protective effects of genistein in homocysteine-induced endothelial cell inflammatory injury

Hyperhomocysteinemia is a risk factor for cardiovascular disease and the mechanism of homocysteine (HCY)-induced vascular endothelial cell injury has been intensively studied for many years. Recently, a large number of studies have shown inhibitory effects of genistein (GEN), a soy isoflavone, in the process of endothelial cell injury. In the present study, the protective effects of GEN in HCY-induced endothelial cell inflammatory injury were investigated. A model of HCY-induced endothelial cell (ECV-304) inflammatory injury was established in vitro, and the protective effect of GEN in this procession was explored. According to our results, GEN protected HCY-induced endothelial cell from viability decreases, meanwhile prevented the changes of cell morphology and the production of reactive oxygen species (ROS). The expression of NF-kB P-65, IL-6, and ICAM-1 was all down-regulated. During the HCY-induced endothelial cell injury, the endothelial cell apoptosis and proliferation disorder were alleviated. Therefore, we conclude that HCY-induced endothelial cell inflammatory injury could be blocked by GEN. The present findings suggest that GEN protects HCY-induced endothelial cell inflammatory injury may through reducing the release of ROS, inhibiting NF-kB activation, down-regulating the expression of cytokine IL-6 and adhesion molecules ICAM-1, avoiding inflammatory cells and platelet adhesion, accordingly, leading to a balance of endothelial cell proliferation and apoptosis.

Emodin-6-O-β-D--glucoside inhibits high-glucose-induced vascular inflammation

Emodin-6-O-β-D-glucoside (EG), a new active compound from Reynoutria japonica, has recently been shown to exert potent anti-inflammatory and barrier protective effects in human umbilical vein endothelial cells (HUVECs) and in mice. Vascular inflammatory process has been suggested to play a key role in initiation and progression of atherosclerosis, a major complication of diabetes mellitus. Thus, we attempted to determine whether EG can suppress the vascular inflammatory process induced by high glucose (HG) in HUVECs and mice. Data showed that HG induced markedly increased vascular permeability, monocyte adhesion, expressions of CAMs, formation of ROS, and activation of NF-κB. Remarkably, all of the above-mentioned vascular inflammatory effects of HG were attenuated by pretreatment with EG. Vascular inflammatory responses induced by HG are critical events underlying development of various diabetic complications; therefore, our results suggest that EG may have significant therapeutic benefits against diabetic complications and atherosclerosis.

PDE5 inhibitors as therapeutics for heart disease, diabetes and cancer

The phosphodiesterase 5 (PDE5) inhibitors, including sildenafil (Viagra™), vardenafil (Levitra™), and tadalafil (Cialis™) have been developed for treatment of erectile dysfunction. Moreover, sildenafil and tadalafil are used for the management of pulmonary arterial hypertension in patients. Since our first report showing the cardioprotective effect of sildenafil in 2002, there has been tremendous growth of preclinical and clinical studies on the use of PDE5 inhibitors for cardiovascular diseases and cancer. Numerous animal studies have demonstrated that PDE5 inhibitors have powerful protective effect against myocardial ischemia/reperfusion (I/R) injury, doxorubicin cardiotoxicity, ischemic and diabetic cardiomyopathy, cardiac hypertrophy, Duchenne muscular dystrophy and the improvement of stem cell efficacy for myocardial repair. Mechanistically, PDE5 inhibitors protect the heart against I/R injury through increased expression of nitric oxide synthases, activation of protein kinase G (PKG), PKG-dependent hydrogen sulfide generation, and phosphorylation of glycogen synthase kinase-3β - a master switch immediately proximal to mitochondrial permeability transition pore and the end effector of cardioprotection. In addition, PDE5 inhibitors enhance the sensitivity of certain types of cancer to standard chemotherapeutic drugs, including doxorubicin. Many clinical trials with PDE5 inhibitors have focused on the potential cardiovascular and anti-cancer benefits. Despite mixed results of these clinical trials, there is a continuing strong interest by basic scientists and clinical investigators in exploring their new clinical uses. It is our hope that future new mechanistic investigations and carefully designed clinical trials would help in reaping additional benefits of PDE5 inhibitors for cardiovascular disease and cancer in patients.

[Complications associated with hyperglycemia in liver transplant patients]

BACKGROUND

Hyperglycemia is a frequent phenomenon in hospitalized patients that is associated with negative outcomes. It is common in liver transplant patients as a result of stress and is related to immunosuppressant drugs. Although studies are few, a history of diabetes and the presentation of hyperglycemia during liver transplantation have been associated with a higher risk for rejection.

AIMS

To analyze whether hyperglycemia during the first 48hours after liver transplantation was associated with a higher risk for infection, rejection, or longer hospital stay.

METHODS

A retrospective cohort study was conducted on patients above the age of 15years that received a liver transplant. Hyperglycemia was defined as a value above 140mg/dl and it was measured in three different manners (as an isolated value, as a mean value, and as a weighted value over time). The relation of hyperglycemia to a risk for acute rejection, infection, or longer hospital stay was evaluated.

RESULTS

Some form of hyperglycemia was present in 94% of the patients during the first 48 post-transplantation hours, regardless of its definition. There was no increased risk for rejection (OR: 1.49; 95%CI: 0.55-4.05), infection (OR: 0.62; 95%CI: 0.16-2.25), or longer hospital stay between the patients that presented with hyperglycemia and those that did not.

CONCLUSIONS

Hyperglycemia during the first 48hours after transplantation appeared to be an expected phenomenon in the majority of patients and was not associated with a greater risk for rejection or infection and it had no impact on the duration of hospital stay.

6,6'-bieckol isolated from Ecklonia cava protects oxidative stress through inhibiting expression of ROS and proinflammatory enzymes in high-glucose-induced human umbilical vein endothelial cells

Hyperglycemia-induced oxidative stress accelerates endothelial cell dysfunctions, which cause various complications of diabetes. The protective effects of 6,6'-bieckol (BEK), one of phlorotannin compound purified from Ecklonia cava against high-glucose-induced oxidative stress was investigated using human umbilical vein endothelial cells (HUVECs), which is susceptible to oxidative stress. High glucose (30 mM) treatment induced HUVECs' cell death, but BEK, at concentration 10 or 50 μg/ml, significantly inhibited the high-glucose-induced cytotoxicity. Furthermore, treatment with BEK dose-dependently decreased thiobarbituric acid reactive substances (TBARS), intracellular reactive oxygen species (ROS) generation, and nitric oxide level increased by high glucose. In addition, high glucose levels induced the overexpressions of inducible nitric oxide synthase (iNOS), cyclooxygenase-2 (COX-2), and nuclear factor-kappa B (NF-κB) proteins in HUVECs, but BEK treatment reduced the overexpressions of these proteins. These findings indicate that BEK is a potential therapeutic agent that will prevent diabetic endothelial dysfunction and related complications.

Emerging drugs for diabetic macular edema

INTRODUCTION

Diabetic macular edema (DME) is the most common cause of visual impairment due to diabetic retinopathy. The treatment of DME has recently undergone a paradigm shift. Traditionally, photocoagulation was standard treatment, but pharmacologic therapies are becoming increasingly used for this purpose. All currently available drug therapies for DME are either anti-VEGF agents or corticosteroids.

AREAS COVERED

The pathogenesis of DME involves angiogenesis, inflammation and oxidative stress. The scientific rationale to treat DME through the pharmacologic blockade of VEGF and other pro-angiogenic factors is discussed. The fluocinolone insert is approved for the treatment of DME in several European countries, but not in the US at this time. Some medications that are already approved for other retinal diseases, most prominently aflibercept and the dexamethasone delivery system, have recently obtained approval for DME in the US. Other compounds are being studied in earlier-phase clinical trials.

EXPERT OPINION

Pharmacologic treatment of DME will likely become increasingly used, especially for patients with edema involving the fovea. At this time, the two main classes of medication for treatment of DME are anti-VEGF agents and corticosteroids. As we continue to collect clinical trials data, the precise role of individual agents, and the continuing role for photocoagulation, will become more clear.

Diabetes mellitus aggravates hemorrhagic transformation after ischemic stroke via mitochondrial defects leading to endothelial apoptosis

Diabetes is a crucial risk factor for stroke and is associated with increased frequency and poor prognosis. Although endothelial dysfunction is a known contributor of stroke, the underlying mechanisms have not been elucidated. The aim of this study was to elucidate the mechanism by which chronic hyperglycemia may contribute to the worsened prognosis following stroke, especially focusing on mitochondrial alterations. We examined the effect of hyperglycemia on hemorrhagic transformation at 24 hours after middle cerebral artery occlusion (MCAO) in streptozotocin (STZ) -induced diabetic mice. We also examined the effects of high-glucose exposure for 6 days on cell death, mitochondrial functions and morphology in human brain microvascular endothelial cells (HBMVECs) or human endothelial cells derived from induced pluripotent stem cells (iCell endothelial cells). Hyperglycemia aggravated hemorrhagic transformation, but not infarction following stroke. High-glucose exposure increased apoptosis, capase-3 activity, and release of apoptosis inducing factor (AIF) and cytochrome c in HBMVECs as well as affected mitochondrial functions (decreased cell proliferation, ATP contents, mitochondrial membrane potential, and increased matrix metalloproteinase (MMP)-9 activity, but not reactive oxygen species production). Furthermore, morphological aberration of mitochondria was observed in diabetic cells (a great deal of fragmentation, vacuolation, and cristae disruption). A similar phenomena were seen also in iCell endothelial cells. In conclusion, chronic hyperglycemia aggravated hemorrhagic transformation after stroke through mitochondrial dysfunction and morphological alteration, partially via MMP-9 activation, leading to caspase-dependent apoptosis of endothelial cells of diabetic mice. Mitochondria-targeting therapy may be a clinically innovative therapeutic strategy for diabetic complications in the future.

Oxidative stress: implications for the development of diabetic retinopathy and antioxidant therapeutic perspectives

In recent decades, localized tissue oxidative stress has been implicated as a key component in the development of diabetic retinopathy (DR). Increasing evidence shows that oxidative stress caused by diabetes-induced metabolic abnormalities is the most common mechanism associated with the pathogenesis of DR for both type 1 and type 2 diabetes. Increase in intracellular reactive oxygen species (ROS) concentrations results in the activation of several mechanisms involved in the pathogenesis of DR. In particular, damage or dysfunction caused by oxidative stress still persists even after glycemia has been normalized. Despite considerable evidence showing the beneficial effects of antioxidants in preventing the development of retinopathy, results from large-scale clinical trials on classic antioxidants are somewhat ambiguous. Scavenging reactive radicals may not be the most ideal antioxidant strategy in DR. Advances in understanding the function of ROS in the development of DR can lead to the development of new therapeutic strategies based on the mechanisms of ROS generation and scavenging. Increasing amounts of data have demonstrated the promising prospect of antioxidant therapy and its beneficial effects in vision protection. Therefore, new strategies that utilize antioxidants as additive therapy should be implemented in the treatment of DR.