Insulin resistance and oxidative stress influence colony-forming unit-endothelial cells capacity in obese patients

Endothelial Colony-Forming Cells (ECFCs) in cerebrovascular aging: Focus on the pathogenesis of Vascular Cognitive Impairment and Dementia (VCID), and treatment prospects

Endothelial colony-forming cells (ECFCs), a unique endothelial progenitor subset, are essential for vascular integrity and repair, providing significant regenerative potential. Recent studies highlight their role in cerebrovascular aging, particularly in the pathogenesis of vascular cognitive impairment and dementia (VCID). Aging disrupts ECFC functionality through mechanisms such as oxidative stress, chronic inflammation, and cellular senescence, leading to compromised vascular repair and reduced neurovascular resilience. ECFCs influence key cerebrovascular processes, including neurovascular coupling (NVC), blood-brain barrier (BBB) integrity, and vascular regeneration, which are critical for cognitive health. Age-related decline in ECFC quantity and functionality contributes to vascular rarefaction, diminished cerebral blood flow (CBF), and BBB permeability-processes that collectively exacerbate cognitive decline. This review delves into the multifaceted role of ECFCs in cerebrovascular aging and underscores their potential as therapeutic targets in addressing age-related vascular dysfunctions, presenting new directions for mitigating the effects of aging on brain health.

Preservation of vascular endothelial repair in mice with diet-induced obesity

INTRODUCTION

Preservation of structural integrity of the endothelial monolayer and maintenance of endothelial cell function are of critical importance in preventing arterial thrombosis, restenosis and atherosclerosis. Obesity has been intimately linked with endothelial dysfunction, and reports of reduced abundance and functional impairment of circulating progenitor cells in obesity have led to the suggestion that defective endothelial repair contributes to obesity-related cardiovascular disease.

METHODS

C57BL/6 mice were fed a high-fat diet for either 3 or 6 months to induce obesity; metabolic phenotyping was then carried out before femoral artery wire injury was performed. Endothelial regeneration was then quantified. Mononuclear cells and myeloid angiogenic cells were cultured and characterized for pro-angiogenic properties.

RESULTS

No impairment of endothelial regeneration following mechanical endothelial injury in diet-induced obese mice when compared with chow-fed controls was observed, despite the induction of an adverse metabolic phenotype characterized by glucose intolerance and insulin resistance. Dietary-obese mice had increased numbers of circulating myeloid angiogenic cells, which retained normal functional properties including intact paracrine angiogenic effects.

CONCLUSION

Preserved endothelial regeneration despite metabolic dysregulation in dietary obese mice suggests that compensatory mechanisms mitigate the deleterious influence of insulin resistance on endothelial repair in obesity.

Number of colony-forming unit-Hill colonies among children and teenagers with obesity, dyslipidemia and breastfeeding history

BACKGROUND AND AIMS

The number of colony-forming unit (CFU)-Hill colonies has been proposed as a biomarker of vascular function and cardiovascular risk in adults but information about its role in children is scarce. This study evaluates the associations between obesity, cardiovascular risk factors and breastfeeding history with the numbers of CFU-Hill colonies in a sample of young people.

METHODS AND RESULTS

We selected 49 children and teenagers between ages 10 and 17 (65.3% boys) from Mexican Health Care system. Physical activity and Anthropometric measures data were registered. CFU-Hill colonies were cultured from mononuclear cells obtained from venous blood. We detected inverse associations between the formation of CFU-Hill colonies and body mass index (BMI; β = -1.53; 95% confidence interval [CI], -1.92, -1.13), triglycerides (β = -0.26; 95%CI = -0.34, -0.18), total cholesterol (β = -0.13; 95%CI = -0.17, -0.08), Low Density Lipoprotein (LDL) (β = -0.20; 95%CI = -0.31, -0.09) and glucose (β = -0.37; 95%CI = -0.55, -0.18) using multivariate models. Breastfeeding duration showed a 1.46-colony increase for each month of breastfeeding (95%CI = 0.73, 2.18).

CONCLUSIONS

CFU-Hill colony-forming capacity in children and teenagers was inversely associated with obesity, dyslipidemia and high blood levels of glucose. In contrast a longer breastfeeding duration was directly associated with an increased number of CFU-Hill colonies. However these results must be confirmed with further studies. Our findings support the importance of promoting breastfeeding and monitoring nutritional and metabolic status at an early age to prevent chronic disease development.

The role of reactive oxygen species in obesity therapeutics

Obesity is a major risk factor for multiple severe health conditions, including cardiovascular diseases, diabetes and cancer. It is often related to an increased risk of morbidity and mortality and, as it can be accompanied by non-fatal health problems, quality of life is seriously reduced due to related conditions including hypertension, sleep apnea, osteoarthritis, respiratory problems and infertility. Evidence suggests that oxidative stress is related to obesity and its complications. In obese patients, there is an increase in levels of reactive oxygen species and nitrogen species and antioxidant defenses are undermined in comparison to normal-weight counterparts. In addition, these parameters inversely correlate with central adiposity. In this review, the authors discuss current concepts concerning the relationship between obesity and oxidative stress and mitochondrial impairment. Potential interventions to improve redox balance are also explored.

A biomarker of oxidative stress as a nontraditional risk factor in obese subjects

BACKGROUND

Oxidative stress has been postulated as an additive factor linking obesity to cardiovascular disease.

MATERIALS & METHODS

Derivatives of reactive oxygen species metabolites (d-ROMs) were measured in 136 obese (42 males, 94 females; mean age: 47 ± 12 years; BMI: 36 ± 5 kg/m(2)) and in 306 over- and normal-weight subjects (112 males, 194 females; age: 47 ± 12 years; BMI: 24 ± 3 kg/m(2)).

RESULTS

d-ROMs levels were higher in obese than in over- and normal-weight subjects (395 ± 104 vs 362 ± 102 and 351 ± 84 arbitrary units (AU); p < 0.001), in women than males (390 ± 104 vs 327 ± 68 AU; p < 0.001), in subjects with than those without hypertension (390 ± 103 vs 360 ± 95 AU; p < 0.01) and in smokers than former and nonsmokers (380 ± 97 vs 358 ± 97 AU; p < 0.05). A positive correlation was found between d-ROMs and BMI (r = 0.25; p < 0.001) and age (r = 0.13; p < 0.01). Levels of d-ROM (>75th percentile: 420 AU) remained as an independent obesity predictor (odds ratio: 2.5; p < 0.001) in women. Continuous variables are reported as mean ± standard deviation.

CONCLUSION

d-ROMs are a powerful obesity predictor, and could represent a reliable tool in obesity and cardiovascular risk evaluation, especially in women.

Importance of insulin resistance to vascular repair and regeneration

Metabolic insulin resistance is apparent across a spectrum of clinical disorders, including obesity and diabetes, and is characterized by an adverse clustering of cardiovascular risk factors related to abnormal cellular responses to insulin. These disorders are becoming increasingly prevalent and represent a major global public health concern because of their association with significant increases in atherosclerosis-related mortality. Endogenous repair mechanisms are thought to retard the development of vascular disease, and a growing evidence base supports the adverse impact of the insulin-resistant phenotype upon indices of vascular repair. Beyond the impact of systemic metabolic changes, emerging data from murine studies also provide support for abnormal insulin signaling at the level of vascular cells in retarding vascular repair. Interrelated pathophysiological factors, including reduced nitric oxide bioavailability, oxidative stress, altered growth factor activity, and abnormal intracellular signaling, are likely to act in conjunction to impede vascular repair while also driving vascular damage. Understanding of these processes is shaping novel therapeutic paradigms that aim to promote vascular repair and regeneration, either by recruiting endogenous mechanisms or by the administration of cell-based therapies.

Supplementation with L-arginine favorably influences plasminogen activator inhibitor type 1 concentration in obese patients. A randomized, double blind trial

BACKGROUND

Elevated plasminogen activator inhibitor type 1 (PAI 1) plays an important role in the pathogenesis of excess blood coagulability in obese patients. L-arginine supplementation has shown to be associated with enhanced cardiovascular and metabolic health. The aim of the study was to assess the effect of L-arginine supplementation on PAI 1 concentration and to evaluate the relation to changes in nitric oxide (NO) plasma level, insulin sensitivity (M value), and total antioxidant status (TAS) in obese patients.

MATERIAL/SUBJECTS AND METHODS

A randomized, double-blind, placebo-controlled study was conducted from March 2010 to June 2011. Eightyeight obese patients were randomly assigned to receive either 9 g of L-arginine or placebo daily for 6 months. At baseline and after 6 months, selected anthropometrical measurements and blood biochemical analyses were performed, and PAI 1, NO, TAS levels were assessed. Insulin sensitivity was evaluated using the hyperinsulinemic euglycemic clamp technique.

RESULTS

We found that 6-month L-arginine supplementation resulted in significant decrease of PAI 1. Significant increase of NO, TAS, and insulin sensitivity level were noticed. In a group of patients treated with L-arginine, negative correlation between a change of insulin sensitivity value and a change of PAI 1 concentration was found.

CONCLUSIONS

The present findings demonstrate favorable influence of L-arginine supplementation on PAI 1 concentration in obese patients. Beneficial influence is related to insulin sensitivity improvement. The potential therapeutic role of L-arginine administration in patients with obesity needs further investigation.

Decreased circulating endothelial progenitor cell levels and function in patients with nonalcoholic fatty liver disease

OBJECTIVES

Nonalcoholic fatty liver disease (NAFLD) is associated with advanced atherosclerosis and a higher risk of cardiovascular disease. Increasing evidence suggests that injured endothelial monolayer is regenerated by circulating bone marrow derived-endothelial progenitor cells (EPCs), and levels of circulating EPCs reflect vascular repair capacity. However, the relation between NAFLD and EPC remains unclear. Here, we tested the hypothesis that patients with nonalcoholic fatty liver disease (NAFLD) might have decreased endothelial progenitor cell (EPC) levels and attenuated EPC function.

METHODS AND RESULTS

A total of 312 consecutive patients undergoing elective coronary angiography because of suspected coronary artery disease were screened and received examinations of abdominal ultrasonography between July 2009 and November 2010. Finally, 34 patients with an ultrasonographic diagnosis of NAFLD, and 68 age- and sex-matched controls without NAFLD were enrolled. Flow cytometry with quantification of EPC markers (defined as CD34(+), CD34(+)KDR(+), and CD34(+)KDR(+)CD133(+)) in peripheral blood samples was used to assess circulating EPC numbers. The adhesive function, and migration, and tube formation capacities of EPCs were also determined in NAFLD patients and controls. Patients with NAFLD had a significantly higher incidence of metabolic syndrome, previous myocardial infarction, hyperuricemia, and higher waist circumference, body mass index, fasting glucose and triglyceride levels. In addition, patients with NAFLD had significantly decreased circulating EPC levels (all P<0.05), attenuated EPC functions, and enhanced systemic inflammation compared to controls. Multivariate logistic regression analysis showed that circulating EPC level (CD34(+)KDR(+) [cells/10(5) events]) was an independent reverse predictor of NAFLD (Odds ratio: 0.78; 95% confidence interval: 0.69-0.89, P<0.001).

CONCLUSIONS

NAFLD patients have decreased circulating EPC numbers and functions than those without NAFLD, which may be one of the mechanisms to explain atherosclerotic disease progression and enhanced cardiovascular risk in patients with NAFLD.