Cellular and molecular mechanisms of endothelial dysfunction in diabetes

Integrative analysis of gene expression, protein abundance, and metabolomic profiling elucidates complex relationships in chronic hyperglycemia-induced changes in human aortic smooth muscle cells

Type 2 diabetes mellitus (T2DM) is a major public health concern with significant cardiovascular complications (CVD). Despite extensive epidemiological data, the molecular mechanisms relating hyperglycemia to CVD remain incompletely understood. We here investigated the impact of chronic hyperglycemia on human aortic smooth muscle cells (HASMCs) cultured under varying glucose conditions in vitro, mimicking normal (5 mmol/L), pre-diabetic (10 mmol/L), and diabetic (20 mmol/L) conditions, respectively. Normal HASMC cultures served as baseline controls, and patient-derived T2DM-SMCs served as disease controls. Results showed significant increases in cellular proliferation, area, perimeter, and F-actin expression with increasing glucose concentration (p < 0.01), albeit not exceeding the levels in T2DM cells. Atomic force microscopy analysis revealed significant decreases in Young's moduli, membrane tether forces, membrane tension, and surface adhesion in SMCs at higher glucose levels (p < 0.001), with T2DM-SMCs being the lowest among all the cases (p < 0.001). T2DM-SMCs exhibited elevated levels of selected pro-inflammatory markers (e.g., ILs-6, 8, 23; MCP-1; M-CSF; MMPs-1, 2, 3) compared to glucose-treated SMCs (p < 0.01). Conversely, growth factors (e.g., VEGF-A, PDGF-AA, TGF-β1) were higher in SMCs exposed to high glucose levels but lower in T2DM-SMCs (p < 0.01). Pathway enrichment analysis showed significant increases in the expression of inflammatory cytokine-associated pathways, especially involving IL-10, IL-4 and IL-13 signaling in genes that are up-regulated by elevated glucose levels. Differentially regulated gene analysis showed that compared to SMCs receiving normal glucose, 513 genes were upregulated and 590 genes were downregulated in T2DM-SMCs; fewer genes were differentially expressed in SMCs receiving higher glucose levels. Finally, the altered levels in genes involved in ECM organization, elastic fiber synthesis and formation, laminin interactions, and ECM proteoglycans were identified. Growing literature suggests that phenotypic switching in SMCs lead to arterial wall remodeling (e.g., change in stiffness, calcific deposits formation), with direct implications in the onset of CVD complications. Our results suggest that chronic hyperglycemia is one such factor that leads to morphological, biomechanical, and functional alterations in vascular SMCs, potentially contributing to the pathogenesis of T2DM-associated arterial remodeling. The observed differences in gene expression patterns between in vitro hyperglycemic models and patient-derived T2DM-SMCs highlight the complexity of T2DM pathophysiology and underline the need for further studies.

Obesity differs from diabetes mellitus in antibody and T-cell responses post-COVID-19 recovery

OBJECTIVE

Obesity and type 2 diabetes (DM) are risk factors for severe coronavirus disease 2019 (COVID-19) outcomes, which disproportionately affect South Asian populations. This study aims to investigate the humoral and cellular immune responses to SARS-CoV-2 in adult COVID-19 survivors with overweight/obesity (Ov/Ob, BMI ≥ 23 kg/m2) and DM in Bangladesh.

METHODS

In this cross-sectional study, SARS-CoV-2-specific antibody and T-cell responses were investigated in 63 healthy and 75 PCR-confirmed COVID-19 recovered individuals in Bangladesh, during the pre-vaccination first wave of the COVID-19 pandemic in 2020.

RESULTS

In COVID-19 survivors, SARS-CoV-2 infection induced robust antibody and T-cell responses, which correlated with disease severity. After adjusting for age, sex, DM status, disease severity, and time since onset of symptoms, Ov/Ob was associated with decreased neutralizing antibody titers, and increased SARS-CoV-2 spike-specific IFN-γ response along with increased proliferation and IL-2 production by CD8 + T cells. In contrast, DM was not associated with SARS-CoV-2-specific antibody and T-cell responses after adjustment for obesity and other confounders.

CONCLUSION

Ov/Ob is associated with lower neutralizing antibody levels and higher T-cell responses to SARS-CoV-2 post-COVID-19 recovery, while antibody or T-cell responses remain unaltered in DM.

Reversal of high-glucose-induced transcriptional and epigenetic memories through NRF2 pathway activation

Diabetes complications such as nephropathy, retinopathy, or cardiovascular disease arise from vascular dysfunction. In this context, it has been observed that past hyperglycemic events can induce long-lasting alterations, a phenomenon termed "metabolic memory." In this study, we evaluated the genome-wide gene expression and chromatin accessibility alterations caused by transient high-glucose exposure in human endothelial cells (ECs) in vitro. We found that cells exposed to high glucose exhibited substantial gene expression changes in pathways known to be impaired in diabetes, many of which persist after glucose normalization. Chromatin accessibility analysis also revealed that transient hyperglycemia induces persistent alterations, mainly in non-promoter regions identified as enhancers with neighboring genes showing lasting alterations. Notably, activation of the NRF2 pathway through NRF2 overexpression or supplementation with the plant-derived compound sulforaphane, effectively reverses the glucose-induced transcriptional and chromatin accessibility memories in ECs. These findings underscore the enduring impact of transient hyperglycemia on ECs' transcriptomic and chromatin accessibility profiles, emphasizing the potential utility of pharmacological NRF2 pathway activation in mitigating and reversing the high-glucose-induced transcriptional and epigenetic alterations.

Extracellular matrix-inspired biomaterials for wound healing

Diabetic foot ulcers (DFU) are a debilitating and life-threatening complication of Diabetes Mellitus. Ulceration develops from a combination of associated diabetic complications, including neuropathy, circulatory dysfunction, and repetitive trauma, and they affect approximately 19-34% of patients as a result. The severity and chronic nature of diabetic foot ulcers stems from the disruption to normal wound healing, as a result of the molecular mechanisms which underly diabetic pathophysiology. The current standard-of-care is clinically insufficient to promote healing for many DFU patients, resulting in a high frequency of recurrence and limb amputations. Biomaterial dressings, and in particular those derived from the extracellular matrix (ECM), have emerged as a promising approach for the treatment of DFU. By providing a template for cell infiltration and skin regeneration, ECM-derived biomaterials offer great hope as a treatment for DFU. A range of approaches exist for the development of ECM-derived biomaterials, including the use of purified ECM components, decellularisation and processing of donor/ animal tissues, or the use of in vitro-deposited ECM. This review discusses the development and assessment of ECM-derived biomaterials for the treatment of chronic wounds, as well as the mechanisms of action through which ECM-derived biomaterials stimulate wound healing.

Single-nucleus RNA transcriptome profiling reveals murine adipose tissue endothelial cell proliferation gene networks involved in obesity development

Endothelial cells play an important role in the metabolism of adipose tissue (AT). This study aimed to analyze the changes that adipose tissue in AT endothelial cells undergo during the development of obesity, using single-nucleus RNA sequence (snRNA-seq). Mouse paraepididymal AT cells were subjected to snRNA-seq with the 10X Genomics platform. The cell types were then clustered using t-distributed stochastic neighbor embedding and unbiased computational informatics analyses. Protein-protein interactions network was established using the STRING database and visualized using Cytoscape. The dataset was subjected to differential gene enrichment analysis. In total, 21,333 cells acquired from 24 mouse paraepididymal AT samples were analyzed using snRNA-seq. This study identified 18 distinct clusters and annotated macrophages, fibroblasts, epithelial cells, T cells, endothelial cells, stem cells, neutrophil cells, and neutrophil cell types based on representative markers. Cluster 12 was defined as endothelial cells. The proportion of endothelial cells decreased with the development of obesity. Inflammatory factors, such as Vegfa and Prdm16 were upregulated in the medium obesity group but downregulated in the obesity group. Genes, such as Prox1, Erg, Flt4, Kdr, Flt1, and Pecam1 promoted the proliferation of AT endothelial cells and maintained the internal environment of AT. This study established a reference model and general framework for studying the mechanisms, biomarkers, and therapeutic targets of endothelial cell dysfunction-related diseases at the single-cell level.

The Complex Immunological Alterations in Patients with Type 2 Diabetes Mellitus on Hemodialysis

It is widely known that diabetes mellitus negatively impacts both the innate immunity (the inflammatory response) and the acquired immunity (the humoral and cellular immune responses). Many patients with diabetes go on to develop chronic kidney disease, which will necessitate hemodialysis. In turn, long-term chronic hemodialysis generates an additional chronic inflammatory response and impairs acquired immunity. The purpose of this paper is to outline and compare the mechanisms that are the basis of the constant aggression towards self-components that affects patients with diabetes on hemodialysis, in order to find possible new therapeutic ways to improve the functionality of the immune system. Our study will take a detailed look at the mechanisms of endothelial alteration in diabetes and hemodialysis, at the mechanisms of inflammatory generation and signaling at different levels and also at the mechanisms of inflammation-induced insulin resistance. It will also discuss the alterations in leukocyte chemotaxis, antigen recognition and the dysfunctionalities in neutrophils and macrophages. Regarding acquired immunity, we will outline the behavioral alterations of T and B lymphocytes induced by diabetes mellitus and chronic hemodialysis.

Immunotherapy targeting the obese white adipose tissue microenvironment: Focus on non-communicable diseases

Obesity triggers inflammatory responses in the microenvironment of white adipose tissue, resulting in chronic systemic inflammation and the subsequent development of non-communicable diseases, including type 2 diabetes, coronary heart disease, and breast cancer. Current therapy approaches for obesity-induced non-communicable diseases persist in prioritizing symptom remission while frequently overlooking the criticality of targeting and alleviating inflammation at its source. Accordingly, this review highlights the importance of the microenvironment of obese white adipose tissue and the promising potential of employing immunotherapy to target it as an effective therapeutic approach for non-communicable diseases induced by obesity. Additionally, this review discusses the challenges and offers perspective about the immunotherapy targeting the microenvironment of obese white adipose tissue.

Neuraminidase inhibition improves endothelial function in diabetic mice

Neuraminidases cleave sialic acids from glycocalyx structures and plasma neuraminidase activity is elevated in type 2 diabetes (T2D). Therefore, we hypothesize circulating neuraminidase degrades the endothelial glycocalyx and diminishes flow-mediated dilation (FMD), whereas its inhibition restores shear mechanosensation and endothelial function in T2D settings. We found that compared with controls, subjects with T2D have higher plasma neuraminidase activity, reduced plasma nitrite concentrations, and diminished FMD. Ex vivo and in vivo neuraminidase exposure diminished FMD and reduced endothelial glycocalyx presence in mouse arteries. In cultured endothelial cells, neuraminidase reduced glycocalyx coverage. Inhalation of the neuraminidase inhibitor, zanamivir, reduced plasma neuraminidase activity, enhanced endothelial glycocalyx length, and improved FMD in diabetic mice. In humans, a single-arm trial (NCT04867707) of zanamivir inhalation did not reduce plasma neuraminidase activity, improved glycocalyx length, or enhanced FMD. Although zanamivir plasma concentrations in mice reached 225.8 ± 22.0 ng/mL, in humans were only 40.0 ± 7.2 ng/mL. These results highlight the potential of neuraminidase inhibition for ameliorating endothelial dysfunction in T2D and suggest the current Food and Drug Administration-approved inhaled dosage of zanamivir is insufficient to achieve desired outcomes in humans.NEW & NOTEWORTHY This work identifies neuraminidase as a key mediator of endothelial dysfunction in type 2 diabetes that may serve as a biomarker for impaired endothelial function and predictive of development and progression of cardiovascular pathologies associated with type 2 diabetes (T2D). Data show that intervention with the neuraminidase inhibitor zanamivir at effective plasma concentrations may represent a novel pharmacological strategy for restoring the glycocalyx and ameliorating endothelial dysfunction.

Roles of mitochondrial dynamics and mitophagy in diabetic myocardial microvascular injury

Myocardial microvessels are composed of a monolayer of endothelial cells, which play a crucial role in maintaining vascular barrier function, luminal latency, vascular tone, and myocardial perfusion. Endothelial dysfunction is a key factor in the development of cardiac microvascular injury and diabetic cardiomyopathy. In addition to their role in glucose oxidation and energy metabolism, mitochondria also participate in non-metabolic processes such as apoptosis, intracellular ion handling, and redox balancing. Mitochondrial dynamics and mitophagy are responsible for regulating the quality and quantity of mitochondria in response to hyperglycemia. However, these endogenous homeostatic mechanisms can both preserve and/or disrupt non-metabolic mitochondrial functions during diabetic endothelial damage and cardiac microvascular injury. This review provides an overview of the molecular features and regulatory mechanisms of mitochondrial dynamics and mitophagy. Furthermore, we summarize findings from various investigations that suggest abnormal mitochondrial dynamics and defective mitophagy contribute to the development of diabetic endothelial dysfunction and myocardial microvascular injury. Finally, we discuss different therapeutic strategies aimed at improving endothelial homeostasis and cardiac microvascular function through the enhancement of mitochondrial dynamics and mitophagy.

Diabetic Endothelial Cell Glycogen Synthase Kinase 3β Activation Induces VCAM1 Ectodomain Shedding

Soluble cell adhesion molecules (sCAMs) are secreted ectodomain fragments of surface adhesion molecules, ICAM1 and VCAM1. sCAMs have diverse immune functions beyond their primary function, impacting immune cell recruitment and activation. Elevated sVCAM1 levels have been found to be associated with poor cardiovascular disease (CVD) outcomes, supporting VCAM1's role as a potential diagnostic marker and therapeutic target. Inhibiting sVCAM1's release or its interaction with immune cells could offer cardioprotection in conditions such as diabetes. Membrane-bound surface adhesion molecules are widely expressed in a wide variety of cell types with higher expression in endothelial cells (ECs). Still, the source of sCAMs in the circulation is not clear. Hypothesizing that endothelial cells (ECs) could be a potential source of sCAMs, this study investigated whether dysfunctional EC signaling mechanisms during diabetes cause VCAM1 ectodomain shedding. Our results from samples from an inducible diabetic mouse model revealed increased sVCAM1 plasma levels in diabetes. Protein analysis indicated upregulated VCAM1 expression and metalloproteases ADAM10 and ADAM17 in diabetic ECs. ADAMs are known for proteolytic cleavage of adhesion molecules, contributing to inflammation. GSK3β, implicated in EC VCAM1 expression, was found to be activated in diabetic ECs. GSK3β activation in control ECs increased ADAM10/17 and VCAM1. A GSK3β inhibitor reduced active GSK3β and VCAM1 ectodomain shedding. These findings suggest diabetic ECs with elevated GSK3β activity led to VCAM1 upregulation and ADAM10/17-mediated sVCAM1 shedding. This mechanism underscores the potential therapeutic role of GSK3β inhibition in reducing the levels of circulating sVCAM1. The complex roles of sCAMs extend well beyond CVD. Thus, unraveling the intricate involvement of sCAMs in the initiation and progression of vascular disease, particularly in diabetes, holds significant therapeutic potential.

miR-34a/SIRT1/HIF-1α axis is involved in cardiac angiogenesis of type 2 diabetic rats: The protective effect of sodium butyrate combined with treadmill exercise

Type 2 diabetes mellitus (T2DM) is one of the most common metabolic disorders worldwide. Recent research has indicated that sodium butyrate (NaB) affects glucose metabolism and exercise has an anti-hyperglycemic effect in diabetes. This study aimed to evaluate the effects of NaB and treadmill exercise on heart angiogenesis through the miR-34a/SIRT1/FOXO1-HIF-1α pathway. Diabetic animals received NaB (400 mg/kg daily, orally) and treadmill exercise for 6 weeks. The effect of NaB and treadmill exercise, alone or combined, on miR-34a expression, SIRT1, FOXO1, HIF-1α levels, and angiogenesis in diabetic heart tissue was measured. Diabetes caused increased miR-34a (p < 0.01) and FOXO1 (p < 0.001) expression levels. Also, SIRT1 (p < 0.001) and HIF-1α (not significant) expression levels were reduced in diabetic rats. NaB and treadmill exercise decreased miR-34a (respectively p < 0.05 and not significant) and FOXO1 (both p < 0.001) expression levels and improved SIRT1 (both not significant) and HIF-1α (respectively p < 0.01 and p < 0.001) levels. Also, NaB combined with treadmill exercise decreased miR-34a (p < 0.001) and FOXO1 (p < 0.001) expression levels, and elevated SIRT1 (p < 0.05) and HIF-1α (p < 0.001) levels in comparison with the diabetic group. NaB and treadmill exercises modulate the expression of miR-34a and the levels of SIRT1, FOXO1, and HIF-1α proteins, thus increasing angiogenesis in the heart tissue of diabetic rats. It can be concluded that NaB and treadmill exercise, alone or combined, may be useful in the treatment of diabetes through the miR-34a/SIRT1/FOXO1-HIF-1α pathway.

Association of Klotho with Coronary Artery Disease in Subjects with Type 2 Diabetes Mellitus and Preserved Kidney Function: A Case-Control Study

Circulating Klotho levels are significantly reduced in subjects with type 2 diabetes mellitus (T2DM) and in kidney disease patients. In this work, the relationship between Klotho levels and the coronary artery disease (CAD) burden in subjects with T2DM and preserved kidney function was analyzed. For this, we performed a cross-sectional case-control study involving 133 subjects with T2DM and 200 age-, sex- and CAD-incidence-matched, non-diabetic patients undergoing non-emergency diagnostic coronary angiography. All of them were non-albuminuric and with normal glomerular filtration rates. The concentrations of serum Klotho, fibroblast growth factor 23, and inflammatory markers were also measured. As expected, the serum Klotho concentration was lower in the T2DM group (12.3% lower, p = 0.04). However, within the group of patients with T2DM, those subjects with CAD presented significantly higher Klotho levels than those without significant coronary stenosis (314.5 (6.15-562.81) vs. 458.97 (275.2-667.2) pg/mL; p = 0.02). Multiple regression analysis revealed that serum Klotho was positively related with stenosis values exclusively in subjects with T2DM (adjusted R2 = 0.153, p < 0.01). Moreover, logistic regression analysis showed that Klotho was positively associated with the presence of significant CAD in the group of T2DM patients (OR: 1.001; p = 0.041). Our data suggest that higher levels of circulating Klotho in subjects with T2DM and preserved kidney function are associated with the presence of significant CAD.

Sexual Dimorphism in Cardiometabolic Diseases: The Role of AMPK

Cardiovascular diseases (CVDs) are the leading cause of mortality and disability among both males and females. The risk of cardiovascular diseases is heightened by the presence of a risk factor cluster of metabolic syndrome, covering obesity and obesity-related cardiometabolic risk factors such as hypertension, glucose, and lipid metabolism dysregulation primarily. Sex hormones contribute to metabolic regulation and make women and men susceptible to obesity development in a different manner, which necessitates sex-specific management. Identifying crucial factors that protect the cardiovascular system is essential to enhance primary and secondary prevention of cardiovascular diseases and should be explicitly studied from the perspective of sex differences. It seems that AMP-dependent protein kinase (AMPK) may be such a factor since it has the protective role of AMPK in the cardiovascular system, has anti-diabetic properties, and is regulated by sex hormones. Those findings highlight the potential cardiometabolic benefits of AMPK, making it an essential factor to consider. Here, we review information about the cross-talk between AMPK and sex hormones as a critical point in cardiometabolic disease development and progression and a target for therapeutic intervention in human disease.

The protective roles of citrus flavonoids, naringenin, and naringin on endothelial cell dysfunction in diseases

The endothelial cells (ECs) make up the inner lining of blood vessels, acting as a barrier separating the blood and the tissues in several organs. ECs maintain endothelium integrity by controlling the constriction and relaxation of the vasculature, blood fluidity, adhesion, and migration. These actions of ECs are efficiently coordinated via an intricate signaling network connecting receptors, and a wide range of cellular macromolecules. ECs are naturally quiescent i.e.; they are not stimulated and do not proliferate. Upon infection or disease, ECs become activated, and this alteration is pivotal in the pathogenesis of a spectrum of human neurological, cardiovascular, diabetic, cancerous, and viral diseases. Considering the central position that ECs play in disease pathogenesis, therapeutic options have been targeted at improving ECs integrity, assembly, functioning, and health. The dietary intake of flavonoids present in citrus fruits has been associated with a reduced risk of endothelium dysfunction. Naringenin (NGN) and Naringin (NAR), major flavonoids in grapefruit, tomatoes, and oranges possess anti-inflammatory, antioxidant properties, and cell survival potentials, which improve the health of the vascular endothelium. In this review, we provide a comprehensive summary and present the advances in understanding of the mechanisms through which NGN and NAR modulate the biomarkers of vascular dysfunction and protect the endothelium against unresolved inflammation, oxidative stress, atherosclerosis, and angiogenesis. We also provide perspectives and suggest further studies that will help assess the efficacy of citrus flavonoids in the therapeutics of human vascular diseases.

Mechanisms of Nrf2 and NF-κB pathways in diabetic wound and potential treatment strategies

The issue of delayed wound healing or nonhealing in diabetic patients presents a challenge for modern medicine. A number of attempts have been made to understand the mechanisms behind diabetic wound. In a hyperglycemic environment, increased intracellular reactive oxygen species (ROS) disturb the balance between oxidation and antioxidant, causing the wound environment to deteriorate. It has been established that the nuclear factor E2-related factor 2 (Nrf2) and nuclear factor-kappa B (NF-κB) pathways play an important role in regulating inflammation and oxidative stress. Several potential treatment strategies involving Nrf2 and/or NF-κB pathways have been explored in previous studies. Hence, we analyzed mechanisms and changes in Nrf2 and NF-κB pathways in response to oxidative stress and inflammation in diabetic environment. Additionally, we reviewed potential treatment strategies from the past five years for diabetic wound by Nrf2 and/or NF-κB pathways, including receptor agonists, vitamins, hormones, exosomes, drugs, plants, and biomaterials. It may be useful to develop drugs to promote diabetic wound healing.

Ambient temperature and ambulatory blood pressure: An hourly-level, longitudinal panel study

BACKGROUND

Variations of blood pressure (BP) related to air temperature have been reported previously; however, no evidence is available regarding the association of hourly ambient temperature with ambulatory blood pressure.

METHODS

We conducted a longitudinal panel study among 1895 patients from an outpatient department who received repeated ambulatory blood pressure monitoring in Urumqi, China between July 2020 and December 2021. We obtained hourly ambient temperature from the nearest monitoring station to the residential address, and measured 4 ambulatory blood pressure indicators. Linear mixed-effect model combined with distributed lag models were applied to investigate the cumulative associations of hourly temperature with BP.

RESULTS

A total of 97,466 valid blood pressure measurements were evaluated. We observed almost linear and monotonically decreasing relationships between temperature and blood pressure. The effects occurred in the same hour, attenuated thereafter and became insignificant approximately 36 h. A 10 °C decrease in temperature was significantly associated with increments of 0.84 mmHg in systolic blood pressure, 0.56 mmHg in diastolic blood pressure, 1.38 mmHg in mean arterial pressure, and 0.66 mmHg in pulse pressure over lag 0 to 36 h. Stronger associations were found among patients of female sex, age between 18 and 65 years, overweight or obesity, minority, less education or in the cold season, as well as those without hypertension or with coronary heart disease, or did not take anti-hypertension medication.

CONCLUSION

Our study provides robust evidence that hourly ambient temperature is inversely associated with ambulatory blood pressure. It also highlights a linear relationship between decreased ambient temperature and elevated BP, which may have implications for the prevention and management of hypertension in susceptible populations.

N6-methylation of RNA-bound adenosine regulator HNRNPC promotes vascular endothelial dysfunction in type 2 diabetes mellitus by activating the PSEN1-mediated Notch pathway

AIM

The regulatory mechanism of m6A regulators in vascular endothelial function of type 2 diabetes mellitus (T2DM) remains largely unknown. We addressed this issue based on the data retrieved Gene Expression Omnibus (GEO) database and experimental validations.

METHODS

Expression of m6A methylation regulators was evaluated in T2DM samples of GSE76894 dataset and GSE156341 dataset. Further analysis of candidate m6A methylation regulators was conducted in the thoracic aorta of db/db mice and high glucose (HG)-induced human umbilical vein endothelial cells (HUVECs). Ectopic expression and depletion experiments were conducted to detect effects of m6A methylation regulators on vascular endothelial function in T2DM.

RESULTS

It emerged that three m6A methylation regulators (HNRNPC, RBM15B, and ZC3H13) were highly expressed in T2DM, which were related to vascular EC function, showing diagnostic values for T2DM. HNRNPC expression in the thoracic aorta of db/db mice was higher than that in heterozygous db mice, and HNRNPC expression in HG-induced HUVECs was upregulated when compared with normal glucose-exposed HUVECs. Furthermore, HNRNPC activated PSEN1-dependent Notch pathway to induce eNOS inactivation and NO production decrease, thereby causing vascular endothelial dysfunction in T2DM.

CONCLUSIONS

HNRNPC impaired vascular endothelial function to enhance the development of vascular complications in T2DM through PSEN1-mediated Notch signaling pathway.

Associations of eicosapentaenoic acid and docosahexaenoic acid intakes with cardiovascular and all-cause mortality in patients with diabetes: Result from National Health and Nutrition Examination Survey 1999-2008

Introduction

The evidence on eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) intake status and long-term mortality among people with diabetes is scarce. This study aimed to investigate the relationship between EPA and DHA intakes with all-cause and cause-specific mortality in adults with diabetes.

Methods

This study included 2,991 adults with diabetes from the National Health and Nutrition Examination Survey (NHANES) 1999-2008. Death outcomes were ascertained by linkage to the database records through 31 December 2015. Cox proportional hazards regression models were used to estimate hazard ratios (HRs) and 95% confidence intervals (CIs) for mortality from all causes, cardiovascular disease (CVD), and coronary heart disease (CHD) in patients with diabetes.

Results

Among 2,991 patients with diabetes, the mean age was 61.9 years (55.2% males). During the mean follow-up duration of 9.4 years, a total of 1,091 deaths were documented, of which 273 were due to CVD, including 227 CHD deaths. EPA and DHA intakes were associated with lower mortality risks, especially that of CVD. After adjusting for demographic, major lifestyle factors, overall dietary intake patterns, and history of hypertension and dyslipidemia, the multivariable HRs (95% CIs) of mortality risk comparing Q4 to Q1 of EPA intake were 0.55 (0.33-0.92; P-trend = 0.019) for CHD, 0.55 (0.36-0.83; P-trend = 0.005) for CVD, and 0.91 (0.70-1.18; P-trend = 0.264) for all-cause. The respective HRs (95% CIs) comparing Q4 to Q1 of DHA were 0.60 (0.37-0.98; P-trend = 0.051) for CHD, 0.58 (0.38-0.89; P-trend = 0.014) for CVD, and 0.92 (0.72-1.18; P-trend = 0.481) for all-cause. In subgroup analysis, we found that the association trends of EPA and DHA intakes with death risk remained robust among patients with diabetes, especially among those who are old, female, those with higher BMI, and dyslipidemia patients with CVD and CHD.

Discussion

In the USA, higher EPA and DHA intakes were associated with a lower risk of CHD and CVD mortality in patients with diabetes. Our study supports the benefits of adequate EPA and DHA intakes in promoting the health of patients with diabetes.

Effect of Carotid Body Denervation on Systemic Endothelial Function in a Diabetic Animal Model

Endothelial dysfunction is an essential intermediary for development of cardiovascular diseases associated with diabetes and hypertension (HT). The carotid body (CB) dysfunction contributes to dysmetabolic states, and the resection of carotid sinus nerve (CSN) prevents and reverts dysmetabolism and HT. Herein, we investigated if CSN denervation ameliorates systemic endothelial dysfunction in an animal model of type 2 diabetes mellitus (T2DM).We used Wistar male rats submitted to HFHSu diet during 25 weeks and the correspondent age-matched controls fed with a standard diet. CSN resection was performed in half of the groups after 14 weeks of diet. In vivo insulin sensitivity, glucose tolerance and blood pressure, ex vivo aortic artery contraction and relaxation and nitric oxide (NO) levels in plasma and aorta, aorta nitric oxide synthase (NOS) isoforms, and PGF2αR levels were evaluated.We demonstrated that, alongside to dysmetabolism and HT reversion, CSN resection restores endothelial function in the aorta and decreases the NO levels in plasma and aorta at the same time that restores normal levels of iNOS in aorta without changing eNOS or PGF2αR levels.These results suggest that the modulation of CB activity can be important for the treatment of HT and endothelial dysfunction related with T2DM.

Effects of single and multiple sessions of lower body diastole-synchronized compressions using a pulsating pneumatic suit on endothelium function and metabolic parameters in patients with type 2 diabetes: two controlled cross-over studies

BACKGROUND

Endothelium function is often impaired in patients with type 2 diabetes. We hypothesized that by improving endothelial function using diastole-synchronized compressions/decompressions (DSCD) to the lower body may improve the metabolic profile. The objective of this research was to evaluate the effects of single and multiple DSCD sessions on microcirculation, endothelium function and metabolic parameters of patients with type 2 diabetes.

METHODS

Two monocentric, controlled, randomized cross-over studies (Study 1 and Study 2) were performed. In Study 1, 16 patients received one 20 min DSCD and one simulated (control) session at 2 week intervals; continuous glucose monitoring and cutaneous blood flow were recorded continuously before, during and after DSCD or Control session; other vascular assessments were performed before and after DSCD and control sessions. In Study 2, 38 patients received 60 min DSCD sessions three times/week for three months followed by a 4-6 week washout and 3 month control period (without simulated sessions); vascular, metabolic, body composition, physical activity and quality of life assessments were performed before and after 3 months.

RESULTS

Both studies showed significant, multiplex effects of DSCD sessions. In Study 1, cutaneous blood flow and endothelium function increased, and plasma and interstitial glucose levels after a standard breakfast decreased after DSCD sessions. In Study 2, cutaneous endothelium function improved, LDL-cholesterol and non-HDL cholesterol decreased, extra-cell water decreased and SF-36 Vitality score increased after 3 months of DSCD sessions.

CONCLUSIONS

Our findings support the beneficial effect of DSCD on the endothelium and show concomitant beneficial metabolic and vitality effects. Future clinical trials need to test whether DSCD use translates into a preventive measure against microvascular diabetic complications and its progression. Trial registration ClinicalTrials.gov identifiers: NCT02293135 and NCT02359461.

The effects of inhibition and siRNA knockdown of collagen-binding integrins on human umbilical vein endothelial cell migration and tube formation

Blood vessels in the body are lined with endothelial cells which have vital roles in numerous physiological and pathological processes. Collagens are major constituents of the extracellular matrix, and many adherent cells express several collagen-binding adhesion receptors. Here, we study the endothelium-collagen interactions mediated by the collagen-binding integrins, α1β1, α2β1, α10β1 and α11β1 expressed in human umbilical vein endothelial cells (HUVECs). Using qPCR, we found expression of the α10 transcript of the chondrocyte integrin, α10β1, along with the more abundant α2, and low-level expression of α1. The α11 transcript was not detected. Inhibition or siRNA knockdown of the α2-subunit resulted in impaired HUVEC adhesion, spreading and migration on collagen-coated surfaces, whereas inhibition or siRNA knockdown of α1 had no effect on these processes. In tube formation assays, inhibition of either α1 or α2 subunits impaired the network complexity, whereas siRNA knockdown of these integrins had no such effect. Knockdown of α10 had no effect on cell spreading, migration or tube formation in these conditions. Overall, our results indicate that the collagen-binding integrins, α1β1 and α2β1 play a central role in endothelial cell motility and self-organisation.

Exploring oxidative stress and endothelial dysfunction as a mechanism linking bisphenol S exposure to vascular disease in human umbilical vein endothelial cells and a mouse model of postnatal exposure

BACKGROUND

Structural analogues used to replace bisphenol A (BPA) since the introduction of new regulatory restrictions are considered emerging environmental toxicants and remain understudied with respect to their biological actions and health effects. Studies reveal a link between BPA exposure and vascular disease in human populations, whereas the vascular effects of BPA substitutes remain largely unknown.

OBJECTIVES

To determine the effect of BPS, a commonly used BPA substitute, on redox balance, nitric oxide (NO) availability and microvascular NO-dependent dilation.

METHODS

In human umbilical vein endothelial cells (HUVEC), production of reactive oxygen species (ROS) and NO after exposure to BPS was measured using fluorescent probes for DCFDA and DAF-FM diacetate, respectively. The contribution of endothelial NO synthase (eNOS) uncoupling to ROS generation was determined by measuring ROS in the presence or absence of an eNOS inhibitor (L-NAME) or eNOS co-factor, BH4, while the contribution of mitochondria-derived ROS was determined by treating cells with mitochondria-specific antioxidants prior to BPS exposure. Bioenergetic profiles were assessed using Seahorse extracellular flux analysis and mitochondria membrane polarization was measured with TMRE and JC-1 assays. In a mouse model of low dose BPS exposure, NO-mediated endothelial function was assessed in pressurized microvessels by inducing endothelium-dependent dilation in the presence or absence of L-NAME.

RESULTS

BPS exposure (≥25 nM) reduced NO and increased ROS production in HUVEC, the latter corrected by treating cells with L-NAME or BH4. BPS exposure led to a loss of mitochondria membrane potential but had no impact on bioenergetic parameters except for a decrease in the spare respiratory capacity. Treatment of HUVEC with mitochondria-specific antioxidants abolished the effect of BPS on NO and ROS. NO-mediated vasodilation was impaired in male mice exposed to BPS.

DISCUSSION

Exposure to BPS may promote cardiovascular disease by perturbing NO-mediated vascular homeostasis through the induction of oxidative stress.

Hypomagnesemia and Cardiovascular Risk in Type 2 Diabetes

Hypomagnesemia is tenfold more common in individuals with type 2 diabetes (T2D), compared to the healthy population. Factors that are involved in this high prevalence are low Mg2+ intake, gut microbiome composition, medication use and presumably genetics. Hypomagnesemia is associated with insulin resistance, which subsequently increases the risk to develop T2D or deteriorates glycaemic control in existing diabetes. Mg2+ supplementation decreases T2D associated features like dyslipidaemia and inflammation; which are important risk factors for cardiovascular disease (CVD). Epidemiological studies have shown an inverse association between serum Mg2+ and the risk to develop heart failure (HF), atrial fibrillation (AF) and microvascular disease in T2D. The potential protective effect of Mg2+ on HF and AF may be explained by reduced oxidative stress, fibrosis and electrical remodeling in the heart. In microvascular disease, Mg2+ reduces the detrimental effects of hyperglycemia and improves endothelial dysfunction. Though, clinical studies assessing the effect of long-term Mg2+ supplementation on CVD incidents are lacking and gaps remain on how Mg2+ may reduce CVD risk in T2D. Despite the high prevalence of hypomagnesemia in people with T2D, routine screening of Mg2+ deficiency to provide Mg2+ supplementation when needed is not implemented in clinical care as sufficient clinical evidence is lacking. In conclusion, hypomagnesemia is common in people with T2D and is both involved as cause, probably through molecular mechanisms leading to insulin resistance, and consequence and is prospectively associated with development of HF, AF and microvascular complications. Whether long-term supplementation of Mg2+ is beneficial, however, remains to be determined.

A Comprehensive Profiling of Cellular Sphingolipids in Mammalian Endothelial and Microglial Cells Cultured in Normal and High-Glucose Conditions

Sphingolipids (SPLs) play a diverse role in maintaining cellular homeostasis. Dysregulated SPL metabolism is associated with pathological changes in stressed and diseased cells. This study investigates differences in SPL metabolism between cultured human primary retinal endothelial (HREC) and murine microglial cells (BV2) in normal conditions (normal glucose, NG, 5 mM) and under high-glucose (HG, 25 mM)-induced stress by sphingolipidomics, immunohistochemistry, biochemical, and molecular assays. Measurable differences were observed in SPL profiles between HREC and BV2 cells. High-glucose treatment caused a >2.5-fold increase in the levels of Lactosyl-ceramide (LacCer) in HREC, but in BV2 cells, it induced Hexosyl-Ceramides (HexCer) by threefold and a significant increase in Sphingosine-1-phosphate (S1P) compared to NG. Altered SPL profiles coincided with changes in transcript levels of inflammatory and vascular permeability mediators in HREC and inflammatory mediators in BV2 cells. Differences in SPL profiles and differential responses to HG stress between endothelial and microglial cells suggest that SPL metabolism and signaling differ in mammalian cell types and, therefore, their pathological association with those cell types.

Vaccarin alleviates endothelial inflammatory injury in diabetes by mediating miR-570-3p/HDAC1 pathway

Vaccarin is a flavonoid glycoside, which has a variety of pharmacological properties and plays a protective role in diabetes and its complications, but its mechanism is unclear. In this study, we aim to investigate whether histone deacetylase 1(HDAC1), a gene that plays a pivotal role in regulating eukaryotic gene expression, is the target of miR-570-3p in diabetic vascular endothelium, and the potential molecular mechanism of vaccarin regulating endothelial inflammatory injury through miR-570-3p/HDAC1 pathway. The HFD and streptozotocin (STZ) induced diabetes mice model, a classical type 2 diabetic model, was established. The aorta of diabetic mice displayed a decrease of miR-570-3p, the elevation of HDAC1, and inflammatory injury, which were alleviated by vaccarin. Next, we employed the role of vaccarin in regulating endothelial cells miR-570-3p and HDAC1 under hyperglycemia conditions in vitro. We discovered that overexpression of HDAC1 counteracted the inhibitory effect of vaccarin on inflammatory injury in human umbilical vein endothelial cells (HUVECs). Manipulation of miRNA levels in HUVECs was achieved by transfecting cells with miR-570-3p mimic and inhibitor. Overexpression of miR-570-3p could decrease the expression of downstream components of HDAC1 including TNF-α, IL-1β, and malondialdehyde, while increasing GSH-Px activity in HUVECs under hyperglycemic conditions. Nevertheless, such phenomenon was completely reversed by miR-570-3p inhibitor, and administration of miR-570-3p inhibitor could block the inhibition of vaccarin on HDAC1 and inflammatory injury. Luciferase reporter assay confirmed the 3′- UTR of the HDAC1 gene was a direct target of miR-570-3p. In summary, our findings suggest that vaccarin alleviates endothelial inflammatory injury in diabetes by mediating miR-570-3p/HDAC1 pathway. Our study provides a new pathogenic link between deregulation of miRNA expression in the vascular endothelium of diabetes and inflammatory injury and provides new ideas, insights, and choices for the scope of application and medicinal value of vaccarin and some potential biomarkers or targets in diabetic endothelial dysfunction and vascular complications.

Recent advances in molecular biology of metabolic syndrome pathophysiology: endothelial dysfunction as a potential therapeutic target

Current advances in molecular pathobiology of endotheliocytes dysfunctions are promising in finding the pathogenetic links to the emergence of insulin resistance syndrome. Physiologically, human organism homeostasis is strictly controlled to maintain metabolic processes at the acquainted level. Many factors are involved in maintaining these physiological processes in the organism and any deviation is undoubtedly accompanied by specific pathologies related to the affected process. Fortunately, the body’s defense system can solve and compensate for the impaired function through its multi-level defense mechanisms. The endothelium is essential in maintaining this homeostasis through its ability to modulate the metabolic processes of the organism. Pathological activity or impairment of physiological endothelium function seems directly correlated to the emergence of metabolic syndrome. The most accepted hypothesis is that endothelium distribution is due to endoplasmic reticulum stress and unfolded protein response development, which includes inhibition of long non-coding RNAs expression, cytokines disbalance, Apelin dysregulation, glycocalyx degradation, and specific microparticles. Clinically, the enhancement or restoration of normal endothelial cells can be a target for novel therapeutic strategies since the distribution of its physiological activity impairs homeostasis and results in the progression of metabolic syndrome, and induction of its physiological activity can ameliorate insulin resistance syndrome. Novel insights on the molecular mechanisms of endothelial cell dysfunction are concisely represented in this paper to enhance the present therapeutic tactics and advance the research forward to find new therapeutic targets.

Autoimmune thyroiditis and celiac disease do not worsen endothelial function in subjects with type 1 diabetes: an observational study

BACKGROUND

Type 1 diabetes (T1D) is frequently associated with autoimmune thyroiditis (AT) and coeliac disease (CD). Whether the coexistence of multiple autoimmune diseases increases cardiovascular risk is uncertain. We evaluated the effects of AT and CD on arterial wall thickening and endothelial function in patients with T1D.

METHODS

This observational study analyzed data from T1D patients regularly followed by the Diabetes Care Centre. Clinical and biochemical characteristics and micro and macrovascular complications were collected from the electronic medical records. All subjects performed Echo-Doppler to evaluate Intima-Media Thickness (IMT) of the common carotid artery (CCA) and endothelial function by the flow-mediated dilation (FMD) technique. The statistical analyses were performed by SPSS for Macintosh. Comparison between means was performed using the t-test for unpaired data and the Mann-Whitney U test. The ANalysis Of VAriance and the Tukey posthoc test were applied to compare patients with and without other autoimmune diseases, and control subjects. The p-value for statistical significance was set at p < 0.05.

RESULTS

A total of 110 patients were enrolled. Among these, 69 had T1D and 41 T1D and AT and or CD, of whom 33 AT, 7 CD, and 1 both AT and CD. The mean age was 35 years, mean HbA1c was 7.6%, and mean diabetes duration 18 years. The IMT of the CCA was not significantly different between T1D patients with and without concomitant autoimmune diseases (with AT and CD: right CCA 603 ± 186 µ, left 635 ± 175 µ; without AT and CD: right CCA 611 ± 176 µ, left CCA 631 ± 200 µ). FMD was also comparable between T1D groups, with AT and CD 7.9 ± 4.2%; without AT and CD 8.8 ± 4.4%.

CONCLUSION

Patients with T1D and concomitant AT and or CD show no worse morphological or functional vascular damage, evaluated by CCA IMT and brachial artery flow-mediated dilation, than patients with T1D alone.

Quantifying the Impact of Algae Supplement on Blood Pressure: Systematic Review and Meta-analysis of Randomized Controlled Trials

The impact of Algae supplements and its extract on blood pressure has not concluded yet. The aim of this systematic review meta-analysis is to evaluate the antihypertensive activity of this group marine organism on human. Alga was used in some studies as capsules (from 500 mg to 8 g) and the follow-up duration changed from 17 days to 9 months. The difference in standardized mean and its corresponding 95% confidence interval (CI) was applied as the effect size of algae supplementation on systolic and diastolic blood pressure. Based on the results, a meta-analysis of 10 studies with baseline effect control demonstrated that there was no difference in the mean systolic blood pressure in the two groups SMD (95%CI): -1.05 (-2.85,0.76), but a significant difference in the mean diastolic blood pressure was observed and showed that the mean diastolic blood pressure in the treatment group was lower than the control group SMD(95%CI): -2.23 (-4.35,-0.11). A meta-analysis of 4 studies with no baseline control effect did not show significant results on both blood pressure. The evidence to support this systematic review meta-analysis requires more investigation and future large scale RCT clinical trial to confirm the results.

Exploring Endothelial Colony-Forming Cells to Better Understand the Pathophysiology of Disease: An Updated Review

Endothelial cell (EC) dysfunction has been implicated in a variety of pathological conditions. The collection of ECs from patients is typically conducted postmortem or through invasive procedures, such as surgery and interventional procedures, hampering efforts to clarify the role of ECs in disease onset and progression. In contrast, endothelial colony-forming cells (ECFCs), also termed late endothelial progenitor cells, late outgrowth endothelial cells, blood outgrowth endothelial cells, or endothelial outgrowth cells, are obtained in a minimally invasive manner, namely, by the culture of human peripheral blood mononuclear cells in endothelial growth medium. ECFCs resemble mature ECs phenotypically, genetically, and functionally, making them excellent surrogates for ECs. Numerous studies have been performed that examined ECFC function in conditions such as coronary artery disease, diabetes mellitus, hereditary hemorrhagic telangiectasia, congenital bicuspid aortic valve disease, pulmonary arterial hypertension, venous thromboembolic disease, and von Willebrand disease. Here, we provide an updated review of studies using ECFCs that were performed to better understand the pathophysiology of disease. We also discuss the potential of ECFCs as disease biomarkers and the standardized methods to culture, quantify, and evaluate ECFCs and suggest the future direction of research in this field.

A systematic review with meta-analysis on the antihypertensive efficacy of Nigerian medicinal plants

ETHNOPHARMACOLOGICAL RELEVANCE

Despite the promising effects of herbal preparations in lowering blood pressure (BP), hypertension remains a major clinical challenge in Nigeria. The BP-lowering effects of medicinal plants are due to the presence of bioactive compounds.

AIM OF THE STUDY

This meta-analysis presents a precise estimate of the therapeutic benefits of medicinal plants utilized in Nigeria for the management of hypertension in animals and humans.

METHODS

A systematic literature search was performed through Cochrane, PubMed, Science Direct and Scopus databases from inception until February 28, 2021 using search terms related to randomized controlled trials of Nigerian medicinal plants for hypertension. Additional studies were identified through manual search. BP was the main outcome that was measured after the intervention. Meta-analysis was performed using the Review Manager and Meta-Essential.

RESULTS

Nineteen trials comprising of 16 preclinical and 3 clinical studies were enrolled for the meta-analysis. A total number of 16 plants was identified of which H. sabdariffa was the highest reported plant. The plant extracts significantly lowered the systolic blood pressure (SBP) and diastolic blood pressure (DBP) of the hypertensive subjects compared to control. Weighted mean difference (WMD) for SBP (-43.60 mmHg, 95% CI: -63.18, -24.01; p<0.0001) and DBP (-29.50 mmHg, 95 CI: -43.66, -15.34; p<0.0001) was observed for the preclinical studies. For clinical trials, the WMD was -13.98 mmHg, 95 CI: -19.08, -8.88; p<0.00001 for SBP and -10.00 mmHg, 95 CI: -12.22, -7.78; p<0.00001 for DBP. High heterogeneity was observed for the outcome measures of preclinical studies, but not for the clinical studies. The observed substantial heterogeneity in preclinical studies may be linked to methodological shortcomings as evidenced by the results of the risk of bias assessment. There was no evidence of publication bias in animal trials for BP using the funnel plot and Egger's regression test (SBP, p=0.239 and DBP, p=0.112).

CONCLUSIONS

This study provides evidence of medicinal preparations for the treatment of hypertension. A well-conducted trial with methodological rigour and a longer duration of follow-up is required for their effective clinical utilization.

LncRNA SNHG15 relieves hyperglycemia-induced endothelial dysfunction via increased ubiquitination of thioredoxin-interacting protein

Numerous studies have revealed that hyperglycemia is a pivotal driver of diabetic vascular complications. However, the mechanisms of hyperglycemia-induced endothelial dysfunction in diabetes remain incompletely understood. This study aims to expound on the underlying mechanism of the endothelial dysfunction induced by hyperglycemia from the perspective of long non-coding RNAs (lncRNA). In this study, a downregulation of SNHG15 was observed in the ischemic hind limb of diabetic mice and high glucose (HG)-treated HUVECs. Functionally, the overexpression of SNHG15 promoted cell proliferation, migration, and tube formation, and suppressed cell apoptosis in HG-treated HUVECs. Mechanistically, SNHG15 reduced thioredoxin-interacting protein (TXNIP) expression by enhancing ITCH-mediated ubiquitination of TXNIP. TXNIP overexpression abrogated the protective effect of lncRNA SNHG15 overexpression on HG-induced endothelial dysfunction. The following experiment further confirmed that SNHG15 overexpression promoted angiogenesis of the ischemic hind limb in diabetic mice. In conclusion, SNHG15 is a novel protector for hyperglycemia-induced endothelial dysfunction via decreasing TXNIP expression.

Insulin Signal Transduction Perturbations in Insulin Resistance

Type 2 diabetes mellitus is a widespread medical condition, characterized by high blood glucose and inadequate insulin action, which leads to insulin resistance. Insulin resistance in insulin-responsive tissues precedes the onset of pancreatic β-cell dysfunction. Multiple molecular and pathophysiological mechanisms are involved in insulin resistance. Insulin resistance is a consequence of a complex combination of metabolic disorders, lipotoxicity, glucotoxicity, and inflammation. There is ample evidence linking different mechanistic approaches as the cause of insulin resistance, but no central mechanism is yet described as an underlying reason behind this condition. This review combines and interlinks the defects in the insulin signal transduction pathway of the insulin resistance state with special emphasis on the AGE-RAGE-NF-κB axis. Here, we describe important factors that play a crucial role in the pathogenesis of insulin resistance to provide directionality for the events. The interplay of inflammation and oxidative stress that leads to β-cell decline through the IAPP-RAGE induced β-cell toxicity is also addressed. Overall, by generating a comprehensive overview of the plethora of mechanisms involved in insulin resistance, we focus on the establishment of unifying mechanisms to provide new insights for the future interventions of type 2 diabetes mellitus.

Anti-fibrotic effects of curcumin and some of its analogues in the heart

Cardiac fibrosis stems from the changes in the expression of fibrotic genes in cardiac fibroblasts (CFs) in response to the tissue damage induced by various cardiovascular diseases (CVDs) leading to their transformation into active myofibroblasts, which produce high amounts of extracellular matrix (ECM) proteins leading, in turn, to excessive deposition of ECM in cardiac tissue. The excessive accumulation of ECM elements causes heart stiffness, tissue scarring, electrical conduction disruption and finally cardiac dysfunction and heart failure. Curcumin (Cur; also known as diferuloylmethane) is a polyphenol compound extracted from rhizomes of Curcuma longa with an influence on an extensive spectrum of biological phenomena including cell proliferation, differentiation, inflammation, pathogenesis, chemoprevention, apoptosis, angiogenesis and cardiac pathological changes. Cumulative evidence has suggested a beneficial role for Cur in improving disrupted cardiac function developed by cardiac fibrosis by establishing a balance between degradation and synthesis of ECM components. There are various molecular mechanisms contributing to the development of cardiac fibrosis. We presented a review of Cur effects on cardiac fibrosis and the discovered underlying mechanisms by them Cur interact to establish its cardio-protective effects.

Antioxidant Therapy and Antioxidant-Related Bionanomaterials in Diabetic Wound Healing

Ulcers are a lower-extremity complication of diabetes with high recurrence rates. Oxidative stress has been identified as a key factor in impaired diabetic wound healing. Hyperglycemia induces an accumulation of intracellular reactive oxygen species (ROS) and advanced glycation end products, activation of intracellular metabolic pathways, such as the polyol pathway, and PKC signaling leading to suppression of antioxidant enzymes and compounds. Excessive and uncontrolled oxidative stress impairs the function of cells involved in the wound healing process, resulting in chronic non-healing wounds. Given the central role of oxidative stress in the pathology of diabetic ulcers, we performed a comprehensive review on the mechanism of oxidative stress in diabetic wound healing, focusing on the progress of antioxidant therapeutics. We summarize the antioxidant therapies proposed in the past 5 years for use in diabetic wound healing, including Nrf2- and NFκB-pathway-related antioxidant therapy, vitamins, enzymes, hormones, medicinal plants, and biological materials.

Association of dietary intake, medication and anthropometric indices with serum levels of advanced glycation end products, caspase-3, and matrix metalloproteinase-9 in diabetic patients

Background and objective

Increased serum levels of advanced glycation end products (AGEs), caspase-3 (Cas-3) and matrix metalloproteinase-9 (MMP-9) have been reported in diabetic patients. This study aimed to evaluate association of anthropometric, dietary, and therapeutic factors with serum levels of methylglyoxal (MGO), carboxymethyl lysine (CML), pentosidine (Pen), Cas-3, and MMP-9 in diabetic patients.

Methods

The current study included 36 diabetic subjects. Dietary intake of the participants was assessed using three-day 24-h recall survey and anthropometric indices were measured. Demographic factors and medication intake of every subject were obtained. Serum levels of CML, MGO, Pen, MMP-9, and Cas-3 were measured using ELISA method.

Results

Gliclazide consumption was positively correlated with MMP-9 and Cas-3, but not AGEs levels. Females had higher MGO level compared with males. Further, CML levels were negatively correlated with BMI and WHR. Dietary protein intake was positively correlated with MMP-9, Cas-3, and MGO levels. As well as dietary energy and fat intake had significant positive relationship with serum Cas-3 concentration.

Conclusion

It is concluded that anthropometric characteristics, dietary intake, and therapeutic medications are possible factors that may determine the circulating levels of AGEs, MMP-9, and Cas-3 in patients with diabetes.

Therapeutic application of Sertoli cells for treatment of various diseases

Sertoli cells (SCs) are immune privileged cells found in the testis that function to immunologically protect maturing germ cells from immune destruction. This immune protection is due to the blood-testis-barrier, which prevents infiltration of cytotoxic immune cells and antibodies, and SC production of immunomodulatory factors, that favor a tolerogenic environment. The ability of SCs to create an immune privileged environment has led to the exploration of their potential use in the treatment of various diseases. SCs have been utilized to create a tolerogenic ectopic microenvironment, to protect co-grafted cells, and to deliver therapeutic proteins through gene therapy. To date, numerous studies have reported the potential use of SCs for the treatment of diabetes, neurodegenerative disorders, and restoration of spermatogenesis. Additionally, SCs have been investigated as a delivery vehicle for therapeutic products to treat other diseases like Laron syndrome, muscular dystrophy, and infections. This review will provide an overview of these therapeutic applications.

C-Peptide as a Therapy for Type 1 Diabetes Mellitus

Diabetes mellitus (DM) is a complex metabolic disease affecting one-third of the United States population. It is characterized by hyperglycemia, where the hormone insulin is either not produced sufficiently or where there is a resistance to insulin. Patients with Type 1 DM (T1DM), in which the insulin-producing beta cells are destroyed by autoimmune mechanisms, have a significantly increased risk of developing life-threatening cardiovascular complications, even when exogenous insulin is administered. In fact, due to various factors such as limited blood glucose measurements and timing of insulin administration, only 37% of T1DM adults achieve normoglycemia. Furthermore, T1DM patients do not produce C-peptide, a cleavage product from insulin processing. C-peptide has potential therapeutic effects in vitro and in vivo on many complications of T1DM, such as peripheral neuropathy, atherosclerosis, and inflammation. Thus, delivery of C-peptide in conjunction with insulin through a pump, pancreatic islet transplantation, or genetically engineered Sertoli cells (an immune privileged cell type) may ameliorate many of the cardiovascular and vascular complications afflicting T1DM patients.

Silk fibroin/polyurethane patch implantation in hyperglycemic rat model

PURPOSE

To understand the complication and histopathological characteristics between the Silk Fibroin/Polyurethanes (SF/PU) and the host response, and to unveil the compatibility of the patch in diabetes individuals.

METHODS

Rats were divided into DM and control (CT) groups, and the DM group was induced with streptozotocin. All groups underwent the SF/PU patch implantation in the abdominal aorta, and the implanted patches were evaluated at one, two, three, and four weeks after implantation.

RESULTS

DM group had more fibrosis formation and a delayed endothelialization compared to the CT group. There was no evidence of chronic inflammation in both DM and CT groups.

CONCLUSIONS

Fibrosis in hyperglycemic individuals could promote the formation of new vascular structures in the implanted patch such as endothelial and vascular smooth muscle cells. In summary, the SF/PU patch was no serious complications when implanted under hyperglycemia, and the patch was suitable to implant in diabetes mellitus.

Advanced Glycation End Product Formation in Human Cerebral Cortex Increases With Alzheimer-Type Neuropathologic Changes but Is Not Independently Associated With Dementia in a Population-Derived Aging Brain Cohort

Diabetes mellitus is a risk factor for dementia, and nonenzymatic glycosylation of macromolecules results in formation of advanced glycation end-products (AGEs). We determined the variation in AGE formation in brains from the Cognitive Function and Ageing Study population-representative neuropathology cohort. AGEs were measured on temporal neocortex by enzyme-linked immunosorbent assay (ELISA) and cell-type specific expression on neurons, astrocytes and endothelium was detected by immunohistochemistry and assessed semiquantitatively. Fifteen percent of the cohort had self-reported diabetes, which was not significantly associated with dementia status at death or neuropathology measures. AGEs were expressed on neurons, astrocytes and endothelium and overall expression showed a positively skewed distribution in the population. AGE measures were not significantly associated with dementia. AGE measured by ELISA increased with Consortium to Establish a Registry for Alzheimer's Disease (CERAD) neurofibrillary tangle score (p = 0.03) and Thal Aβ phase (p = 0.04), while AGE expression on neurons (and astrocytes), detected immunohistochemically, increased with increasing Braak tangle stage (p < 0.001), CERAD tangle score (p = 0.002), and neuritic plaques (p = 0.01). Measures of AGE did not show significant associations with cerebral amyloid angiopathy, microinfarcts or neuroinflammation. In conclusion, AGE expression increases with Alzheimer's neuropathology, particular later stages but is not independently associated with dementia. AGE formation is likely to be important for impaired brain cell function in aging and Alzheimer's.

LncRNA SNHG15 relieves hyperglycemia-induced endothelial dysfunction via increasing ubiquitination of thioredoxin-interacting protein

OBJECTIVE

Numerous evidence indicates that hyperglycemia is a pivotal driver of the vascular complications of diabetes. However, the mechanisms of hyperglycemia-induced endothelial dysfunction in diabetes remain incompletely understood. This study aims to expound on the underlying mechanism of the endothelial dysfunction induced by hyperglycemia from the perspective of long non-coding RNAs (lncRNA).

MATERIALS AND METHODS

Cell proliferation, migration, apoptosis, and tube formation were measured by cell counting kit-8 assay, transwell assay, flow cytometry, and tube formation assay, respectively. RNA pull-down and RNA-binding protein immunoprecipitation were used to detect the interaction between lncRNA SNHG15 and thioredoxin-interacting protein (TXNIP). Co-immunoprecipitation was used to detect the ubiquitination level of TXNIP and the interaction between TXNIP and E3 ubiquitin ligase ITCH.

RESULTS

A downregulation of SNHG15 was observed in the ischemic hind limb of diabetic mice and high glucose (HG)-treated HUVECs. Functionally, the overexpression of SNHG15 promoted cell proliferation, migration, and tube formation, and suppressed cell apoptosis in HG-treated HUVECs. Mechanically, SNHG15 reduced TXNIP expression by enhancing ITCH-mediated ubiquitination of TXNIP. TXNIP overexpression abrogated the protective effect of LncRNA SNHG15 overexpression on HG-induced endothelial dysfunction. The following experiment further confirmed that SNHG15 overexpression promoted angiogenesis of the ischemic hind limb in diabetic mice.

CONCLUSION

SNHG15 is a novel protector for hyperglycemia-induced endothelial dysfunction via decreasing TXNIP expression.

Resveratrol-Elicited PKC Inhibition Counteracts NOX-Mediated Endothelial to Mesenchymal Transition in Human Retinal Endothelial Cells Exposed to High Glucose

Diabetes-associated long-term hyperglycaemia leads to oxidative stress-mediated fibrosis in different tissues and organs. Endothelial-to-mesenchymal-transition (EndMT) appears to play a role in diabetes-associated fibrotic conditions. Here, we investigate whether EndMT is implicated in the diabetic retinopathy fibrotic process and evaluate the possibility that resveratrol could counteract EndMT by inhibiting high glucose (HG)-induced increases in ROS. Primary Human Retinal Endothelial Cells (HRECs) were either pre-treated for 24 h with 1 µM resveratrol or left untreated, then glucose (30 mM) was applied at 3-day intervals for 10 days. qRT-PCR and ELISA were used to detect mRNA or protein expression of endothelial markers (CD31, CDH5, vWF) or mesenchymal markers (VIM, αSMA and collagen I), respectively. Intracellular ROS levels were measured with carboxy-DCFDA, while NOX-associated ROS levels were evaluated using the NADPH-specific redox biosensor p47-roGFP. Treatment of HRECs with HG increased intracellular ROS levels and promoted phenotype shifting towards EndMT, evidenced by decreased expression of endothelial markers concomitant with increased expression of mesenchymal ones. HG-induced EndMT appears to be mediated by NADPH-associated ROS generation as pre-treatment of HRECs with resveratrol or the NADPH inhibitor, diphenyleneiodonium chloride (DPI), attenuated ROS production and EndMT transition, suggesting that the effect of resveratrol on HG-induced ROS occurs via down-regulation of NADPH oxidase. It is worth noting that resveratrol or Chelerythrine, a Protein kinase C (PKC) inhibitor, reduce ROS and EndMT in HG-exposed cells, suggesting that NADPH activation occurs via a PKC-dependent mechanism. Taken together, our results provide the basis for a resveratrol-based potential protective therapy to prevent diabetic-associated complications.

Type 2 diabetes mellitus-associated transcriptome alterations in cortical neurones and associated neurovascular unit cells in the ageing brain

Type 2 diabetes mellitus (T2D), characterised by peripheral insulin resistance, is a risk factor for dementia. In addition to its contribution to small and large vessel disease, T2D may directly damage cells of the brain neurovascular unit. In this study, we investigated the transcriptomic changes in cortical neurones, and associated astrocytes and endothelial cells of the neurovascular unit, in the ageing brain. Neurone, astrocyte, and endothelial cell-enriched mRNA, obtained by immuno-laser capture microdissection of temporal cortex (Brodmann area 21/22) from 6 cases with self-reported T2D in the Cognitive Function and Ageing Study neuropathology cohort, and an equal number of age and sex-matched controls, was assessed by microarray analysis. Integrated Molecular Pathway Level Analysis was performed using the Kyoto Encyclopaedia of Genes and Genomes database on significantly differentially expressed genes, defined as P < 0.05 and fold-change ± 1.2. Hub genes identified from Weighted Gene Co-expression Network Analysis were validated in neurones using the NanoString nCounter platform. The expression and cellular localisation of proteins encoded by selected candidate genes were confirmed by immunohistochemistry. 912, 2202, and 1227 genes were significantly differentially expressed between cases with self-reported T2D and controls in neurones, astrocytes, and endothelial cells respectively. Changes in cortical neurones included alterations in insulin and other signalling pathways, cell cycle, cellular senescence, inflammatory mediators, and components of the mitochondrial respiratory electron transport chain. Impaired insulin signalling was shared by neurovascular unit cells with, additionally, apoptotic pathway changes in astrocytes and dysregulation of advanced glycation end-product signalling in endothelial cells. Transcriptomic analysis identified changes in key cellular pathways associated with T2D that may contribute to neuronal damage and dysfunction. These effects on brain cells potentially contribute to a diabetic dementia, and may provide novel approaches for therapeutic intervention.

Transcriptomic Changes of Murine Visceral Fat Exposed to Intermittent Hypoxia at Single Cell Resolution

Intermittent hypoxia (IH) is a hallmark of obstructive sleep apnea (OSA) and induces metabolic dysfunction manifesting as inflammation, increased lipolysis and insulin resistance in visceral white adipose tissues (vWAT). However, the cell types and their corresponding transcriptional pathways underlying these functional perturbations are unknown. Here, we applied single nucleus RNA sequencing (snRNA-seq) coupled with aggregate RNA-seq methods to evaluate the cellular heterogeneity in vWAT following IH exposures mimicking OSA. C57BL/6 male mice were exposed to IH and room air (RA) for 6 weeks, and nuclei from vWAT were isolated and processed for snRNA-seq followed by differential expressed gene (DEGs) analyses by cell type, along with gene ontology and canonical pathways enrichment tests of significance. IH induced significant transcriptional changes compared to RA across 14 different cell types identified in vWAT. We identified cell-specific signature markers, transcriptional networks, metabolic signaling pathways, and cellular subpopulation enrichment in vWAT. Globally, we also identify 298 common regulated genes across multiple cellular types that are associated with metabolic pathways. Deconvolution of cell types in vWAT using global RNA-seq revealed that distinct adipocytes appear to be differentially implicated in key aspects of metabolic dysfunction. Thus, the heterogeneity of vWAT and its response to IH at the cellular level provides important insights into the metabolic morbidity of OSA and may possibly translate into therapeutic targets.

Oxidative Stress in Ischemic Heart Disease

One of the novel interesting topics in the study of cardiovascular disease is the role of the oxidation system, since inflammation and oxidative stress are known to lead to cardiovascular diseases, their progression and complications. During decades of research, many complex interactions between agents of oxidative stress, oxidation, and antioxidant systems have been elucidated, and numerous important pathophysiological links to na number of disorders and diseases have been established. This review article will present the most relevant knowledge linking oxidative stress to vascular dysfunction and disease. The review will focus on the role of oxidative stress in endotheleial dysfunction, atherosclerosis, and other pathogenetic processes and mechanisms that contribute to the development of ischemic heart disease.

Endothelial Dysfunction in Diabetes Is Aggravated by Glycated Lipoproteins; Novel Molecular Therapies

Diabetes and its vascular complications affect an increasing number of people. This disease of epidemic proportion nowadays involves abnormalities of large and small blood vessels, all commencing with alterations of the endothelial cell (EC) functions. Cardiovascular diseases are a major cause of death and disability among diabetic patients. In diabetes, EC dysfunction (ECD) is induced by the pathological increase of glucose and by the appearance of advanced glycation end products (AGE) attached to the plasma proteins, including lipoproteins. AGE proteins interact with their specific receptors on EC plasma membrane promoting activation of signaling pathways, resulting in decreased nitric oxide bioavailability, increased intracellular oxidative and inflammatory stress, causing dysfunction and finally apoptosis of EC. Irreversibly glycated lipoproteins (AGE-Lp) were proven to have an important role in accelerating atherosclerosis in diabetes. The aim of the present review is to present up-to-date information connecting hyperglycemia, ECD and two classes of glycated Lp, glycated low-density lipoproteins and glycated high-density lipoproteins, which contribute to the aggravation of diabetes complications. We will highlight the role of dyslipidemia, oxidative and inflammatory stress and epigenetic risk factors, along with the specific mechanisms connecting them, as well as the new promising therapies to alleviate ECD in diabetes.

Natural Sweeteners: The Relevance of Food Naturalness for Consumers, Food Security Aspects, Sustainability and Health Impacts

At a moment when the population is increasingly aware and involved in what it eats, both consumers and the food sector are showing more interest in natural foods. This review work discusses, addresses and provides details of the most important aspects of consumer's perceptions of and attitudes to natural foods and in-depth research into natural sweeteners. It also includes issues about their use and development as regards health impacts, food security and sustainability. In line with our main research outcome, we can assume that consumers are very keen on choosing foods with clean labelling, natural ingredients, preferably with other functional properties, without the loss of taste. In response to such a phenomenon, the food industry offers consumers alternative natural sweeteners with the advantage of added health benefits. It is noteworthy that Nature is a superb source of desirable substances, and many have a sweet taste, and many still need to be studied. Finally, we must stress that being natural does not necessarily guarantee market success.

Does Lipocalin-2 Affect Metabolic Syndrome in Hepatic Infections?

Background and objective

Lipocalin-2 (LCN-2) is an adipokine that plays a protective role in various inflammatory disorders and regulates innate immune response to acute and chronic infections. However, scant information is available regarding the relationship between serum LCN-2 levels and type 2 diabetes mellitus (T2DM) occurring concurrently with chronic hepatic infections. The present study sought to investigate the association of LCN-2 with T2DM patients with hepatic infections.

Methods

The association of LCN-2 with T2DM, hepatic steatosis, and inflammation was tested in 37 non-T2DM noninfectious individuals (group A, control group) and 55 age-matched patients with T2DM and chronic infection (group B). Anthropometric data were measured and the body-fat percentage was calculated using bioelectrical impedance analysis (BIA). Hemoglobin (Hb), fasting plasma glucose (FPG), hemoglobin A1c (HbA1c), liver function enzymes (LFEs), lipid profile, and total leukocyte count (TLC) were measured. Serum LCN-2 levels were measured using a commercially available sandwich enzyme-linked immunosorbent assay method.

Results

Levels of LCN-2 were significantly elevated in group B (1896.90 ± 73.13 ng/ml) versus control group A (263.58 ± 15.66 ng/mL; p<0.001). LCN-2 correlated moderately with alanine aminotransferase (ALT) (r=0.369), alkaline phosphatase ALP (r=0.419), and HbA1c (r=0.341) (p<0.01). All correlations were lost when adjusted for the presence of hepatitis, indicating that liver infection exacerbates insulin resistance.

Conclusion

Based on our findings, circulating LCN-2 is elevated in T2DM subjects with hepatitis B co-infection and may contribute towards deranged inflammatory response.

The role of diabetes in the onset and development of endothelial dysfunction

The vascular endothelium performs many functions. It is a key regulator of vascular homeostasis, maintains a balance between vasodilation and vasoconstriction, inhibition and stimulation of smooth muscle cell migration and proliferation, fibrinolysis and thrombosis, and is involved to regulation of platelet adhesion and aggregation. Endothelial dysfunction (ED) plays the critical role in pathogenesis of diabetes mellitus (DM) vascular complications. The purpose of this review was to consider the mechanisms leading to the occurrence of ED in DM. The paper discusses current literature data concerning the role of hyperglycemia, oxidative stress, advanced glycation end products in endothelial alteration. A separate section is devoted to the particularities of the functioning of the antioxidant system and their significance in the development of ED in DM. The analysis of the literature allows to conclude that pathological activation of glucose utilization pathways causes damage of endothelial cells, which is accompanied by disorders of all their basic functions. Metabolic disorders in DM cause a pronounced imbalance of free radical processes and antioxidant defense, accompanied by oxidative stress of endotheliocytes, which contributes to the progression of ED and the development of vascular complications. Many aspects of multicomponent regulatory reactions in the pathogenesis of the development of ED in DM have not been sufficiently studied.