scholarly journals Vascular Aging in Rodent Models: Contrasting Mechanisms Driving the Female and Male Vascular Senescence

2021 ◽  
Vol 2 ◽  
Author(s):  
Paula R. Barros ◽  
Tiago J. Costa ◽  
Eliana H. Akamine ◽  
Rita C. Tostes

Increasing scientific interest has been directed to sex as a biological and decisive factor on several diseases. Several different mechanisms orchestrate vascular function, as well as vascular dysfunction in cardiovascular and metabolic diseases in males and females. Certain vascular sex differences are present throughout life, while others are more evident before the menopause, suggesting two important and correlated drivers: genetic and hormonal factors. With the increasing life expectancy and aging population, studies on aging-related diseases and aging-related physiological changes have steeply grown and, with them, the use of aging animal models. Mouse and rat models of aging, the most studied laboratory animals in aging research, exhibit sex differences in many systems and physiological functions, as well as sex differences in the aging process and aging-associated cardiovascular changes. In the present review, we introduce the most common aging and senescence-accelerated animal models and emphasize that sex is a biological variable that should be considered in aging studies. Sex differences in the cardiovascular system, with a focus on sex differences in aging-associated vascular alterations (endothelial dysfunction, remodeling and oxidative and inflammatory processes) in these animal models are reviewed and discussed.

2008 ◽  
Vol 101 (5) ◽  
pp. 633-658 ◽  
Author(s):  
Amy R. Lomax ◽  
Philip C. Calder

β2-1 Fructans are carbohydrate molecules with prebiotic properties. Through resistance to digestion in the upper gastrointestinal tract, they reach the colon intact, where they selectively stimulate the growth and/or activity of beneficial members of the gut microbiota. Through this modification of the intestinal microbiota, and by additional mechanisms, β2-1 fructans may have beneficial effects upon immune function, ability to combat infection, and inflammatory processes and conditions. In this paper, we have collated, summarised and evaluated studies investigating these areas. Twenty-one studies in laboratory animals suggest that some aspects of innate and adaptive immunity of the gut and the systemic immune systems are modified by β2-1 fructans. In man, two studies in children and nine studies in adults indicate that the adaptive immune system may be modified by β2-1 fructans. Thirteen studies in animal models of intestinal infections conclude a beneficial effect of β2-1 fructans. Ten trials involving infants and children have mostly reported benefits on infectious outcomes; in fifteen adult trials, little effect was generally seen, although in specific situations, certain β2-1 fructans may be beneficial. Ten studies in animal models show benefit of β2-1 fructans with regard to intestinal inflammation. Human studies report some benefits regarding inflammatory bowel disease (four positive studies) and atopic dermatitis (one positive study), but findings in irritable bowel syndrome are inconsistent. Therefore, overall the results indicate that β2-1 fructans are able to modulate some aspects of immune function, to improve the host's ability to respond successfully to certain intestinal infections, and to modify some inflammatory conditions.


2021 ◽  
Vol 2 ◽  
Author(s):  
Andrew V. Kuczmarski ◽  
Laura M. Welti ◽  
Kerrie L. Moreau ◽  
Megan M. Wenner

Aging is a primary risk factor for cardiovascular disease (CVD), which is the leading cause of death in developed countries. Globally, the population of adults over the age of 60 is expected to double by the year 2050. CVD prevalence and mortality rates differ between men and women as they age in part due to sex-specific mechanisms impacting the biological processes of aging. Measures of vascular function offer key insights into cardiovascular health. Changes in vascular function precede changes in CVD prevalence rates in men and women and with aging. A key mechanism underlying these changes in vascular function is the endothelin (ET) system. Studies have demonstrated sex and sex hormone effects on endothelin-1 (ET-1), and its receptors ETA and ETB. However, with aging there is a dysregulation of this system resulting in an imbalance between vasodilation and vasoconstriction. Thus, ET-1 may play a role in the sex differences observed with vascular aging. While most research has been conducted in pre-clinical animal models, we describe more recent translational data in humans showing that the ET system is an important regulator of vascular dysfunction with aging and acts through sex-specific ET receptor mechanisms. In this review, we present translational evidence (cell, tissue, animal, and human) that the ET system is a key mechanism regulating sex-specific changes in vascular function with aging, along with therapeutic interventions to reduce ET-mediated vascular dysfunction associated with aging. More knowledge on the factors responsible for the sex differences with vascular aging allow for optimized therapeutic strategies to attenuate CVD risk in the expanding aging population.


2008 ◽  
Vol 197 (3) ◽  
pp. 447-462 ◽  
Author(s):  
Inmaculada C Villar ◽  
Adrian J Hobbs ◽  
Amrita Ahluwalia

The vascular endothelium plays a crucial role in the regulation of vascular homeostasis by controlling vascular tone, coagulation, and inflammatory responses. These actions are exerted by endothelial factors including nitric oxide, prostacyclin, and endothelium-derived hyperpolarizing factor (EDHF). The greater incidence of cardiovascular disease (CVD) in men and postmenopausal women compared with premenopausal women implies a vasoprotective phenotype of females, which may be influenced by sex hormones. These hormones, particularly estrogen, have modulatory effects on the endothelium and circulating cells that have been implicated in vascular inflammation and in the development of CVD. EDHF seems to be the predominant endothelial factor in the resistance vasculature of females and this mediator could afford the beneficial cardiovascular risk profile observed in premenopausal woman. In this review, we discuss sex differences in EDHF biology and how sex hormones can modulate EDHF responses. We also review the implication of sex hormone-dependent regulation of EDHF in inflammatory processes, platelet function, and repair after vascular damage, each of which have a critical role in several aspects of the pathogenesis of CVD.


Hypertension ◽  
2016 ◽  
Vol 68 (suppl_1) ◽  
Author(s):  
Augusto C Montezano ◽  
Ross Hepburn ◽  
Delyth Graham ◽  
Rhian M Touyz

Osteoprotegerin (OPG) levels are increased in metabolic diseases, and are a biomarker of vascular dysfunction and cardiovascular risk. Mechanisms related to OPG-induced vascular dysfunction and its role in hypertension are not fully understood, but we previously demonstrated that OPG induces vascular dysfunction through ROS-dependent mechanisms. Here we assessed the molecular mechanisms whereby OPG regulates ROS and vascular function, with a focus on syndecan-1. VSMCs from normotensive (WKY) and hypertensive (SHRSP) rats were stimulated with OPG (50 ng/mL). ROS production was measured by lucigenin, amplex red and ELISA. In VSMCs from WKY rats, OPG increased ROS generation (158±15% vs veh, p<0.05). This effect was blocked by the syndecan-1 inhibitor (synstatin) and by removal of syndecan-1 sulfate proteoglycans side chains, chondroitinase and heparinase. OPG also increased H 2 O 2 (2 fold) and ONOO - (1.5 fold) levels in VSMCs (p<0.05). H 2 O 2 further stimulates ROS levels and redox signalling through activation of TRPM2, a redox-sensitive Ca 2+ channel. TRPM2 inhibitors, 8-bromo-ADPR (8Br) and N-(p-amylcinnamoyl)anthranilic acid (ACA), did not block OPG-induced ROS generation in VSMCs from WKY rats. Syndecan-1 activation leads to FAK and c-Src activation, which are redox-sensitive signalling proteins. FAK, but not c-Src, activation (117±2%, p<0.05) was observed after OPG stimulation of WKY VSMCs. In VSMCS from SHRSP rats, OPG effects on ROS generation were exacerbated (230±40%, p<0.05) and inhibited by synstatin, 8Br and ACA. OPG also increased FAK (118±2) and c-Src (113±1) activation (p<0.05) in VSMCs from SHRSP rats. In conclusion, OPG regulation of oxidative stress is increased in hypertension and involves not only syndecan-1, but also TRPM2 channels, which may lead to activation of redox-sensitive proteins and vascular damage.


2020 ◽  
Vol 26 (30) ◽  
pp. 3768-3777 ◽  
Author(s):  
Jamaira A. Victorio ◽  
Rafael M. da Costa ◽  
Rita C. Tostes ◽  
Ana P. Davel

In addition to the endothelium, the perivascular adipose tissue (PVAT) has been described to be involved in the local modulation of vascular function by synthetizing and releasing vasoactive factors. Under physiological conditions, PVAT has anticontractile and anti-inflammatory effects. However, in the context of hypertension, obesity and type 2 diabetes, the PVAT pattern of anticontractile adipokines is altered, favoring oxidative stress, inflammation and, consequently, vascular dysfunction. Therefore, dysfunctional PVAT has become a target for therapeutic intervention in cardiometabolic diseases. An increasing number of studies have revealed sex differences in PVAT morphology and in the modulatory effects of PVAT on endothelial function and vascular tone. Moreover, distinct mechanisms underlying PVAT dysfunction may account for vascular abnormalities in males and females. Therefore, targeting sex-specific mechanisms of PVAT dysfunction in cardiovascular diseases is an evolving strategy for cardiovascular protection.


Molecules ◽  
2021 ◽  
Vol 26 (11) ◽  
pp. 3406
Author(s):  
Benjamin Zimmerman ◽  
Payel Kundu ◽  
William D. Rooney ◽  
Jacob Raber

In both humans and animal models, consumption of a high-saturated-fat diet has been linked to vascular dysfunction and cognitive impairments. Laboratory animals provide excellent models for more invasive high-fat-diet-related research. However, the physiological differences between humans and common animal models in terms of how they react metabolically to high-fat diets need to be considered. Here, we review the factors that may affect the translatability of mechanistic research in animal models, paying special attention to the effects of a high-fat diet on vascular outcomes. We draw attention to the dissociation between metabolic syndrome and dyslipidemia in rodents, unlike the state in humans, where the two commonly occur. We also discuss the differential vulnerability between species to the metabolic and vascular effects of macronutrients in the diet. Findings from animal studies are better interpreted as modeling specific aspects of dysfunction. We conclude that the differences between species provide an opportunity to explore why some species are protected from the detrimental aspects of high-fat-diet-induced dysfunction, and to translate these findings into benefits for human health.


2020 ◽  
Vol 319 (1) ◽  
pp. F33-F40
Author(s):  
Nicholas T. Kruse ◽  
Zhiying You ◽  
Kerrie Moreau ◽  
Jessica Kendrick ◽  
Diana Jalal

Vascular dysfunction plays an important role in the etiology of chronic kidney disease (CKD) and is associated with cardiovascular diseases. Sex differences in vascular function are common in clinical and nonclinical populations. However, no data exist in individuals with CKD. The present study tested the hypothesis that sex and/or aging differences exist in vascular function in patients with CKD. Endothelium-dependent dilation (EDD; measured via brachial artery flow-mediated dilation) and endothelium-independent dilation (EID; measured via nitroglycerin-mediated dilation) were assessed. Analyses were adjusted for several variables that could influence vascular function (diabetes, cardiovascular disease, and blood pressure). Women, in general, had higher EDD values than men (6.5 ± 4.9% vs. 4.4 ± 3.4%); however, EID did not differ among these groups. In younger men and women (<55 yr old), EDD and EID were higher ( P < 0.05) than their older (≥55 yr old) counterparts (EDD: 7.0 ± 4.1% vs. 4.4 ± 3.8% and EID: 24.0 ± 9.6% vs. 18.3 ± 9.2%). Additionally, younger women exhibited higher ( P < 0.05) EDD and EID compared with younger men (EDD: 9.5 ± 6.4% vs. 5.1 ± 3.8%, P = 0.01, and EID: 24.0 ± 9.6% vs. 18.3 ± 9.2%). No differences in EDD and EID were present between older men and women with CKD. Diabetes independently predicted lower EID but not EDD in men and women. Blood pressure and cardiovascular disease did not predict EDD or EID. This is the first study to show significant sex differences in vascular function. Moreover, these differences are evident between younger men and women with CKD but are abolished with age. Additional studies are needed to better understand the mechanisms that may underlie sex differences in vascular dysfunction with CKD.


Author(s):  
Elizabeth Hampson

Organizational and activational effects of sex steroids were first discovered in laboratory animals, but these concepts extend to hormonal actions in the human central nervous system. This chapter begins with a brief overview of how sex steroids act in the brain and how the organizational-activational hypothesis originated in the field of endocrinology. It then reviews common methods used to study these effects in humans. Interestingly, certain cognitive functions appear to be subject to modification by sex steroids, and these endocrine influences may help explain the sex differences often seen in these functions. The chapter considers spatial cognition as a representative example because the spatial family of functions has received the most study by researchers interested in the biological roots of sex differences in cognition. The chapter reviews evidence that supports an influence of both androgens and estrogens on spatial functions, and concludes with a glimpse of where the field is headed.


2021 ◽  
Vol 7 (16) ◽  
pp. eabf2856
Author(s):  
Thibaux Van der Stede ◽  
Laura Blancquaert ◽  
Flore Stassen ◽  
Inge Everaert ◽  
Ruud Van Thienen ◽  
...  

Exercise training is a powerful strategy to prevent and combat cardiovascular and metabolic diseases, although the integrative nature of the training-induced adaptations is not completely understood. We show that chronic blockade of histamine H1/H2 receptors led to marked impairments of microvascular and mitochondrial adaptations to interval training in humans. Consequently, functional adaptations in exercise capacity, whole-body glycemic control, and vascular function were blunted. Furthermore, the sustained elevation of muscle perfusion after acute interval exercise was severely reduced when H1/H2 receptors were pharmaceutically blocked. Our work suggests that histamine H1/H2 receptors are important transducers of the integrative exercise training response in humans, potentially related to regulation of optimal post-exercise muscle perfusion. These findings add to our understanding of how skeletal muscle and the cardiovascular system adapt to exercise training, knowledge that will help us further unravel and develop the exercise-is-medicine concept.


Author(s):  
Pablo Garrido-Gil ◽  
Ana I Rodriguez-Perez ◽  
Lucia Lage ◽  
Jose L Labandeira-Garcia

Abstract The physiopathological mechanisms that regulate menopausal and sex differences in colonic transit, inflammatory processes, and efficacy of treatments have not been clarified. The dopaminergic system and renin–angiotensin system coexist in the gut and regulate different processes such as motility, absorption/secretion, and inflammation. We investigated the changes in expression of major angiotensin and dopamine receptors in the colon of male, female, and ovariectomized female mice. Possible interaction between both systems was investigated using male and female mice deficient (ko) for major angiotensin and dopamine receptors. In wild-type mice, colonic tissue from females showed lower angiotensin type 1/angiotensin type 2 ratio (an index of pro-inflammatory/anti-inflammatory renin–angiotensin system balance), lower dopamine D1 and D2 receptor expression, and lower levels of pro-inflammatory and pro-oxidative markers relative to males. Interestingly, ovariectomy increased the expression of pro-inflammatory angiotensin type 1 receptor expression and decreased anti-inflammatory angiotensin type 2 receptor expression, increased D1 and D2 receptor expression, and increased the levels of pro-inflammatory and pro-oxidative markers. Ovariectomy-induced changes were blocked by estrogen replacement. The present results suggest a mutual regulation between colonic angiotensin and dopamine receptors and sex differences in this mutual regulation. Estrogen regulates changes in both angiotensin and dopamine receptor expression, which may be involved in sex- and surgical menopause-related effects on gut motility, permeability, and vulnerability to inflammatory processes.


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