Biomarkers of frailty.

Several biomarkers have been proposed to identify frailty, a multisystemic age-related syndrome. However, the complex pathophysiology and the absence of a consensus on a comprehensive and universal definition make it challenging to pinpoint a singular biomarker or set of biomarkers that conclusively characterize frailty. This review delves into the main laboratory biomarkers, placing special emphasis on those associated with various pathways closely tied to the frailty condition, such as inflammation, oxidative stress, mitochondrial dysfunction, metabolic and endocrine alterations and microRNA. Additionally, we provide a summary of different clinical biomarkers encompassing different tools that have been proposed to assess frailty. We further address various imaging biomarkers such as Dual Energy X-ray Absorptiometry, Bioelectrical Impedance analysis, Computed Tomography and Magnetic Resonance Imaging, Ultrasound and D3 Creatine dilution. Intervention to treat frailty, including non-pharmacological ones, especially those involving physical exercise and nutrition, and pharmacological interventions, that include those targeting specific mechanisms such as myostatin inhibitors, insulin sensitizer metformin and with special relevance for hormonal treatments are mentioned. We further address the levels of different biomarkers in monitoring the potential positive effects of some of these interventions. Despite the availability of numerous biomarkers, their performance and usefulness in the clinical arena are far from being satisfactory. Considering the multicausality of frailty, there is an increasing need to assess the role of sets of biomarkers and the combination between laboratory, clinical and image biomarkers, in terms of sensitivity, specificity and predictive values for the diagnosis and prognosis of the different outcomes of frailty to improve detection and monitoring of older people with frailty or at risk of developing it, being this a need in the everyday clinical practice.

PKC Inhibition Improves Human Penile Vascular Function and the NO/cGMP Pathway in Diabetic Erectile Dysfunction: The Role of NADPH Oxidase.

Erectile dysfunction (ED) is a frequent and difficult-to-treat condition in diabetic men. Protein kinase C (PKC) is involved in diabetes-related vascular and cavernosal alterations. We aimed to evaluate the role of PKC in endothelial dysfunction and NO/cGMP impairment associated with diabetic ED in the human corpus cavernosum (CC) and penile resistance arteries (PRAs) and the potential mechanisms involved. Functional responses were determined in the CC and PRAs in patients with non-diabetic ED and diabetic ED undergoing penile prosthesis insertion. PKC activator 12,13-phorbol-dibutyrate (PDBu) impaired endothelial relaxations and cGMP generation in response to acetylcholine in the CC from non-diabetic ED. PDBu also impaired responses to a PDE5 inhibitor, sildenafil, in non-diabetic ED patients. Conversely, a PKC inhibitor, GF109203X, improved endothelial, neurogenic, and PDE5-inhibitor-induced relaxations and cGMP generation only in the CC in diabetic ED patients. Endothelial and PDE5-inhibitor-induced vasodilations of PRAs were potentiated only in diabetes. Improvements in endothelial function in diabetes were also achieved with a specific inhibitor of the PKCß2 isoform or an NADPH-oxidase inhibitor, apocynin, which prevented PDBu-induced impairment in non-diabetic patients. PKC inhibition counteracted NO/cGMP impairment and endothelial dysfunction in diabetes-related ED, potentially improving response to PDE5 inhibition.

Fat Mass Accounts for Insulin Resistance Impact on Functional Decline and Mortality in Nondiabetic Older Adults.

OBJECTIVE: To assess the potential role of body composition in the association of insulin resistance (IR) with functional decline and mortality in nondiabetic older persons. DESIGN: Longitudinal population-based cohort of community-dwelling people from Toledo, Spain, aged 65 years or older. SETTING AND PARTICIPANTS: A total of 1114 nondiabetic persons from the Toledo Study of Healthy Aging cohort (mean age: 74.5, 56.10% female) with complete data at baseline were included. Only 914 participants had fully assessment of functional evaluation during the follow-up period. METHODS: IR was determined by the homeostasis model assessment index (HOMA-IR) at baseline while frailty was assessed by the Frailty Trait Scale-5 (FTS-5) at baseline and after 2.99 years' median follow-up period. A total of 319 participants experienced functional decline (2.5-point reduction in the FTS-5 score). A total of 143 deaths were recorded (6.31 years median follow-up) from the Spanish National Death Index. Body compositions were determined using dual-energy x-ray absorptiometry. Multivariate regression models analyzed the effect of HOMA-IR on outcomes, with age, sex, Charlson index, and number of medications included in the basic adjustment model. RESULTS: A 1-logaritmic unit increment in HOMA-IR increased the risk of functional decline after basic adjustment [odds ratio (95% confidence interval): 1.41 (1.09-1.83), P = .009]. This significant association was lost when further adjusted for total fat mass [1.14 (0.86-1.50)] and trunk fat mass [1.03 (0.77-1.37)], which accounted for 62.92% and 91.49% of the association. HOMA-IR was inversely associated with mortality risk [hazard ratio 0.66 (0.49-0.87), P = .0037], an association lost after adjustment for total fat mass [0.74 (0.55-1.01)] and trunk fat mass [0.80 (0.58-1.09)], accounting for 29.05% and 45.78% of the association. Adjustment by lean mass did not modify any of the associations. CONCLUSIONS AND IMPLICATIONS: Body fat mass, especially in the trunk region, mediates the association of IR with functional decline and to a lesser extent with reduced risk of mortality in nondiabetic older subjects.

Upregulation of Orai Channels Contributes to Aging-Related Vascular Alterations in Rat Coronary Arteries.

Vascular territories display heterogeneous sensitivity to the impacts of aging. The relevance of the STIM/Orai system to vascular function depends on the vascular bed. We aimed to evaluate the contribution of the STIM/Orai system to aging-related vascular dysfunction in rat coronary circulation. Vascular function was evaluated according to myography in coronary arteries from young (three-month-old) and older (twenty-month-old) rats. The effects of aging and STIM/Orai inhibition on the contraction and relaxation of the coronary arteries and on the protein expression of STIM-1, Orai1, and Orai3 in these vessels were determined. Aging-related hypercontractility to serotonin and endothelin-1 in arteries from male rats was reversed by STIM/Orai inhibition with YM-58483 or by specifically blocking the Orai1 channel with Synta66. The inhibitory effects of Synta66 on coronary vasoconstriction were also observed in older female rats. YM-58483 relaxed serotonin- but not KCl-contracted arteries from males. STIM/Orai inhibition improved defective endothelial vasodilations in aged arteries, even in the presence of NO synthase and cyclooxygenase inhibitors, but not in KCl-contracted segments. YM-58483 significantly enhanced relaxations to calcium-activated potassium channel stimulation in aged vessels. Increased protein expression of Orai1 and Orai3 was detected in arterial homogenates and sections from older rats. Upregulation of the Orai channel contributes to aging-related coronary dysfunction, revealing a potential target in reducing CVD risk.

Functional Role of STIM-1 and Orai1 in Human Microvascular Aging.

The impact of aging on vascular function is heterogeneous depending on the vascular territories. Calcium regulation plays a key role in vascular function and has been implicated in aging-related hypercontractility of corpus cavernosum. We aimed to evaluate stromal interaction molecule (STIM)/Orai system involvement in aging-related vascular alterations in the human macro and microvasculature. Aortae specimens and mesenteric arteries (MA), obtained from 45 organ donors, were functionally evaluated in organ chambers and wire myographs. Subjects were divided into groups either younger or older than 65-years old. The expressions of STIM-1, Orai1, and Orai3 were determined by immunofluorescence in the aorta and MA, and by Western blot in the aorta homogenates. The inhibition of STIM/Orai with YM-58483 (20 µM) reversed adrenergic hypercontractility in MA from older subjects but did not modify aging-related hypercontractility in the aortic strips. Aging was related to an increased expression of Orai1 in human aorta, while Orai1 and STIM-1 were upregulated in MA. STIM-1 and Orai1 protein expressions were inversely correlated to endothelial function in MA. Circulating levels of Orai1 were correlated with the inflammatory factor TNF-α and with the endothelial dysfunction marker asymmetric dimethylarginine. Aging is associated with an increased expression of the STIM/Orai system in human vessels with functional relevance only in the microvascular territory, suggesting its role in aging-related microvascular dysfunction.

STIM/Orai Inhibition as a Strategy for Alleviating Diabetic Erectile Dysfunction Through Modulation of Rat and Human Penile Tissue Contractility and in vivo Potentiation of Erectile Responses.

BACKGROUND: Stromal interaction molecule (STIM)/Orai calcium entry system appears to have a role in erectile dysfunction (ED) pathophysiology but its specific contribution to diabetic ED was not elucidated. AIM: To evaluate STIM/Orai inhibition on functional alterations associated with diabetic ED in rat and human penile tissues and on in vivo erectile responses in diabetic rats. METHODS: Rat corpus cavernosum (RCC) strips from nondiabetic (No DM) and streptozotocin-induced diabetic (DM) rats and human penile resistance arteries (HPRA) and corpus cavernosum (HCC) from ED patients undergoing penile prosthesis insertion were functionally evaluated in organ chambers and wire myographs. Erectile function in vivo in rats was assessed by intracavernosal pressure (ICP) responses to cavernous nerve electrical stimulation (CNES). Expression of STIM/Orai elements in HCC was determined by immunofluorescence and immunoblot. MAIN OUTCOME MEASURES: Functional responses in RCC, HCC and HPRA and STIM/Orai protein expression in HCC. In vivo erectile responses to CNES. RESULTS: Inhibition of Orai channels with YM-58483 (20 µM) significantly reduced adrenergic contractions in RCC but more effectively in DM. Thromboxane-induced and neurogenic contractions were reduced by STIM/Orai inhibition while defective endothelial, neurogenic and PDE5 inhibitor-induced relaxations were enhanced by YM-58483 (10 µM) in RCC from DM rats. In vivo, YM-58483 caused erections and attenuated diabetes-related impairment of erectile responses. YM-58483 potentiated the effects of PDE5 inhibition. In human tissues, STIM/Orai inhibition depressed adrenergic and thromboxane-induced contractions in ED patients more effectively in those with type 2 diabetes. Diabetes was associated with increased expression of Orai1 and Orai3 in ED patients. CLINICAL TRANSLATION: Targeting STIM/Orai to alleviate diabetes-related functional alterations of penile vascular tissue could improve erectile function and potentiate therapeutic effects of PDE5 inhibitors in diabetic ED. STRENGTHS AND LIMITATIONS: Improving effects of STIM/Orai inhibition on diabetes-related functional impairment was evidenced in vitro and in vivo in an animal model and validated in human tissues from ED patients. Functional findings were complemented with expression results. Main limitation was low numbers of human experiments due to limited human tissue availability. CONCLUSIONS: STIM/Orai inhibition alleviated alterations of functional responses in vitro and improved erectile responses in vivo in diabetic rats, potentiating the effects of PDE5 inhibition. STIM/Orai inhibition was validated as a target to modulate functional alterations of human penile vascular tissue in diabetic ED where Orai1 and Orai3 channels were upregulated. STIM/Orai inhibition could be a potential therapeutic strategy to overcome poor response to conventional ED therapy in diabetic patients. Sevilleja-Ortiz A, El Assar M, García-Gómez B, et al. STIM/Orai Inhibition as a Strategy for Alleviating Diabetic Erectile Dysfunction Through Modulation of Rat and Human Penile Tissue Contractility and in vivo Potentiation of Erectile Responses. J Sex Med 2022;19:1733-1749.

Effect of Physical Activity/Exercise on Oxidative Stress and Inflammation in Muscle and Vascular Aging.

Functional status is considered the main determinant of healthy aging. Impairment in skeletal muscle and the cardiovascular system, two interrelated systems, results in compromised functional status in aging. Increased oxidative stress and inflammation in older subjects constitute the background for skeletal muscle and cardiovascular system alterations. Aged skeletal muscle mass and strength impairment is related to anabolic resistance, mitochondrial dysfunction, increased oxidative stress and inflammation as well as a reduced antioxidant response and myokine profile. Arterial stiffness and endothelial function stand out as the main cardiovascular alterations related to aging, where increased systemic and vascular oxidative stress and inflammation play a key role. Physical activity and exercise training arise as modifiable determinants of functional outcomes in older persons. Exercise enhances antioxidant response, decreases age-related oxidative stress and pro-inflammatory signals, and promotes the activation of anabolic and mitochondrial biogenesis pathways in skeletal muscle. Additionally, exercise improves endothelial function and arterial stiffness by reducing inflammatory and oxidative damage signaling in vascular tissue together with an increase in antioxidant enzymes and nitric oxide availability, globally promoting functional performance and healthy aging. This review focuses on the role of oxidative stress and inflammation in aged musculoskeletal and vascular systems and how physical activity/exercise influences functional status in the elderly.

Dual effects of insulin resistance on mortality and function in non-diabetic older adults: findings from the Toledo Study of Healthy Aging.

Insulin signalling declines with increasing age and impacts skeletal muscle function and longevity in animal models. Our aim was to assess the relationships between insulin resistance (IR) and frailty and mortality in a unique community-dwelling cohort of older people. 991 non-diabetic subjects from the Toledo Study of Healthy Ageing (TSHA) cohort were included. IR was estimated by the homeostasis model assessment index (HOMA-IR) at baseline while frailty was determined by frailty phenotype (FP) and Frailty Trait Scale (FTS) at baseline and after 5-year follow-up. Deaths were also determined. Multivariate regression models were used to analyze the effects of HOMA-IR on outcomes. Age, gender, BMI, education level, cardio- and cerebro-vascular disease, glomerular filtration rate, and disability were included as potential confounding variables in progressive adjustment models. IR determined as increasing log HOMA-IR was inversely associated with risk of mortality. The association remained significant for all adjustment models (HR: 0.64-0.69). When we analyzed survival curves, the higher the HOMA-IR tertile, the lower the mortality rate (highest vs lowest tertile, p = 0.0082). In contrast, IR increased the risk of incident frailty determined by FP (OR 1.81 [1.14-2.87]) as well as deterioration of frailty status determined by worsening in FTS score (OR 1.28 [1.01-1.63]) at 5-year follow-up. In non-diabetic older subjects, IR significantly increases the risk for frailty and functional decline but decreased the risk of death at 5-year follow-up. This finding raises the need of assessing the effect of biomarkers on different outcomes before establishing their role as biomarkers of aging.

Ageing-induced hypercontractility is related to functional enhancement of STIM/Orai and upregulation of Orai 3 in rat and human penile tissue.

The role of STIM/Orai calcium entry system on vascular ageing has not been elucidated. We aimed to evaluate the influence of ageing on STIM/Orai signalling and its role on ageing-induced alterations of contractile function in rat corpus cavernosum (RCC) and human penile resistance arteries (HPRA) and corpus cavernosum (HCC). RCC was obtained from 3 months-old and 20 months-old animals. HPRA and HCC were obtained from organ donors of varied ages without history of erectile dysfunction. Aging was associated with enhanced norepinephrine (NE)- and thromboxane analogue (U46619)-induced contractions in RCC which were significantly inhibited by the STIM/Orai inhibitor, YM-58483 (20 µM). Other STIM/Orai inhibitor, 2-aminoethyldiphenylborate also reduced NE-induced contractions in RCC from aged rats. YM-58483 significantly reduced neurogenic contractions and potentiated neurogenic relaxations in RCC from aged rats. In HCC and HPRA, NE-induced contractions were significantly enhanced in older subjects (>65 years-old) but YM-58483 completely reversed ageing-related hypercontractility. Ageing did not modify STIM-1 and Orai1 protein expressions but Orai3 was significantly overexpressed in cavernosal tissue from old rats and older subjects. Contribution of STIM/Orai to cavernosal contraction increases with ageing together with increased expression of Orai3. Orai inhibition could be a potential therapeutic strategy to reduce ageing-related impact on vascular/erectile function.

Hyperphosphatemia-Induced Oxidant/Antioxidant Imbalance Impairs Vascular Relaxation and Induces Inflammation and Fibrosis in Old Mice.

Aging impairs vascular function, but the mechanisms involved are unknown. The aim of this study was to analyze whether aging-related hyperphosphatemia is implied in this effect by elucidating the role of oxidative stress. C57BL6 mice that were aged 5 months (young) and 24 months (old), receiving a standard (0.6%) or low-phosphate (0.2%) diet, were used. Isolated mesenteric arteries from old mice showed diminished endothelium-dependent vascular relaxation by the down-regulation of NOS3 expression, increased inflammation and increased fibrosis in isolated aortas, compared to those isolated from young mice. In parallel, increased Nox4 expression and reduced Nrf2, Sod2-Mn and Gpx1 were found in the aortas from old mice, resulting in oxidant/antioxidant imbalance. The low-phosphate diet improved vascular function and oxidant/antioxidant balance in old mice. Mechanisms were analyzed in endothelial (EC) and vascular smooth muscle cells (SMCs) treated with the phosphate donor ß-glycerophosphate (BGP). In EC, BGP increased Nox4 expression and ROS production, which reduced NOS3 expression via NFκB. BGP also increased inflammation in EC. In SMC, BGP increased Collagen I and fibronectin expression by priming ROS production and NFκB activity. In conclusion, hyperphosphatemia reduced endothelium-dependent vascular relaxation and increased inflammation and vascular fibrosis through an impairment of oxidant/antioxidant balance in old mice. A low-phosphate diet achieved improvements in the vascular function in old mice.

Association between telomere length, frailty and death in older adults.

Frailty is considered a clinical marker of functional ageing. Telomere length (TL) has been proposed as a biomarker of biological age but its role in human ageing is controversial. The main aim of the study was to evaluate the longitudinal association of TL with incident frailty and mortality in two cohorts of Spanish community-dwelling older adults. TL was determined at baseline in blood samples from older adults included in Toledo Study for Healthy Aging and ENRICA cohorts while frailty was determined by frailty phenotype (FP) at baseline and at follow-up (3.5 years). Deaths occurring during follow-up were also recorded. Associations of TL with frailty and mortality were analysed by logistic regression with progressive adjustment. Data were separately analysed in the two cohorts and in all subjects by performing a meta-analysis. TL was not different between frail and non-frail subjects. Longer telomeres were not associated with lower risk of prevalent frailty. Similarly, TL at baseline failed to predict incident frailty (OR: 1.04 [0.88-1.23]) or even the development of a new FP criterion (OR: 0.97 [0.90-1.05]) at follow-up. Lack of association was also observed when analysing the development of specific FP criteria. Finally, while frailty at baseline was significantly associated with higher risk of death at follow-up (OR: 4.08 [1.97-8.43], p < 0.001), TL did not significantly change the mortality risk (OR: 1.05 [0.94-1.16]). Results show that TL does not predict incident frailty or mortality in older adults. This suggests that TL is not a reliable biomarker of functional age.

Erectile dysfunction is associated with defective L-cysteine/hydrogen sulfide pathway in human corpus cavernosum and penile arteries.

H2S signaling was proposed to participate in erectile physiology. L-cysteine (CYS)/H2S pathway stimulation causes cGMP-dependent relaxation of human corpus cavernosum (HCC) and penile arteries (HPRA). The aim was to evaluate the impact of ED on CYS/H2S pathway at functional and molecular level in human penile vascular tissues. NaHS- and CYS-induced responses were evaluated in HCC and HPRA from organ donors without ED (NoED, n = 29) and from ED patients undergoing penile prosthesis insertion (n = 45). cGMP accumulation and cystathionine ß-synthase and cystathionine γ-lyase expression were also determined. NaHS-induced relaxations were slightly but significantly impaired in HCC but not in HPRA from ED patients. In contrast, CYS-induced relaxations were markedly impaired in HCC (Emax 67.6 ± 4.9% vs 46.2 ± 4.6%, P < 0.01) and HPRA (Emax 80.8 ± 4.0% vs 48.1 ± 8.6%, P < 0.05) from men with ED. Impairment of CYS-induced responses was observed even after separating diabetic ED patients. In HPRA from ED patients, CYS- but not NaHS-induced vasodilation was significantly associated to endothelial function measured as vasodilatory capacity of acetylcholine (ACh) in these preparations (r2 = 0.481, P < 0.01). Impairment of CYS-induced relaxations was related to significant reduction in CYS-induced accumulation of cGMP in cavernosal tissue. Furthermore, the expression of H2S synthesizing enzymes was significantly reduced in HCC from ED patients with respect to NoED. This was confirmed by immunofluorescence in HCC and HPRA sections. ED involves impairment of CYS/H2S pathway in penile vascular tissues associated with decreased expression of H2S generating enzymes, CBS and CSE. These evidences support a therapeutic potential for modulation of CYS/H2S signaling in the management of ED.

Physical activity and exercise: Strategies to manage frailty.

Frailty, a consequence of the interaction of the aging process and certain chronic diseases, compromises functional outcomes in the elderly and substantially increases their risk for developing disabilities and other adverse outcomes. Frailty follows from the combination of several impaired physiological mechanisms affecting multiple organs and systems. And, though frailty and sarcopenia are related, they are two different conditions. Thus, strategies to preserve or improve functional status should consider systemic function in addition to muscle conditioning. Physical activity/exercise is considered one of the main strategies to counteract frailty-related physical impairment in the elderly. Exercise reduces age-related oxidative damage and chronic inflammation, increases autophagy, and improves mitochondrial function, myokine profile, insulin-like growth factor-1 (IGF-1) signaling pathway, and insulin sensitivity. Exercise interventions target resistance (strength and power), aerobic, balance, and flexibility work. Each type improves different aspects of physical functioning, though they could be combined according to need and prescribed as a multicomponent intervention. Therefore, exercise intervention programs should be prescribed based on an individual's physical functioning and adapted to the ensuing response.

Enhanced Contribution of Orai Channels to Contractility of Human Penile Smooth Muscle in Erectile Dysfunction.

BACKGROUND: Store-operated calcium entry and its key players, stromal interaction molecule (STIM) and Orai calcium channels, have been proposed as emergent therapeutic targets in cardiovascular pathophysiology. We hypothesize alteration of STIM/Orai signaling in erectile dysfunction (ED). AIM: To evaluate the contribution of STIM/Orai to human penile tissue contraction and to analyze the influence of ED on STIM/Orai signaling at functional and expression levels in human penile vascular tissues. METHODS: Human penile resistance arteries (HPRA) and human corpus cavernosum (HCC) were dissected from cavernosal specimens from 30 organ donors without history of ED (No ED) and from 48 patients with ED undergoing penile prosthesis insertion and functionally evaluated in wire myographs and organ chambers, respectively. Expression of STIM-1, Orai1, and Orai3 in HCC was localized and quantified by immunofluorescence. MAIN OUTCOME MEASURES: The main outcome measures are functional responses in HCC and HPRA and STIM/Orai channel protein expression in human cavernosal tissue. RESULTS: Inhibition of Orai channels with YM-58483 (20 µM) significantly reduced norepinephrine-induced contractions in both HCC and HPRA from either No ED or ED subjects, but the effects were more marked in ED (-20.1 ± 5.9% vs -45.5 ± 13.2% and -15.9 ± 4.0% vs -31.4 ± 6.9% reduction in Emax to norepinephrine in HCC and HPRA, respectively). Thromboxane-induced contractions were reduced and neurogenic contractile and relaxant responses modulated by Orai inhibition in penile tissues from patients with ED. In fact, addition of YM-58483 concentration dependently relaxed precontracted HPRA and HCC. These relaxations were significantly more pronounced in tissues from patients with ED (EC50 7.5 vs 1.3 µM and 10.5 vs 1.3 µM, for HCC and HPRA, respectively). All HCC specimens displayed expression of STIM-1, Orai1, and Orai3. Significantly increased expression of Orai1 and Orai3 but not STIM-1 was observed in patients with ED. CLINICAL TRANSLATION: Inhibition of enhanced Orai activity in human penile vascular tissue could facilitate erectile responses, alleviating ED. STRENGTHS AND LIMITATIONS: Enhanced STIM/Orai activity contribution to penile smooth muscle tone in ED is demonstrated at functional and structural levels in human tissues from a representative sample of patients with ED and in comparison with healthy tissue. We cannot differentiate the specific contribution of risk factors associated with ED to hyperactivity of the Orai system. CONCLUSIONS: Orai channels significantly contribute to human penile smooth muscle contraction. Orai contribution to penile smooth muscle tone is functionally enhanced in ED accompanied by increased expression of Orai channels in cavernosal tissue. Orai inhibition could be a potential therapeutic strategy to reduce penile smooth muscle contraction in ED. Sevilleja-Ortiz A, El Assar M, García-Rojo E, et al. Enhanced Contribution of Orai Channels to Contractility of Human Penile Smooth Muscle in Erectile Dysfunction. J Sex Med 2020;17:881-891.

Frailty as a phenotypic manifestation of underlying oxidative stress.

Oxidative stress plays a key role in the aging process. Lifestyle behaviours including low physical activity and inadequate nutritional habits in addition to genetic susceptibility and some chronic diseases compromise physiological response to free radicals and promote oxidative damage. Reduced resilience (referred to the ability to respond to stressors or adverse conditions) or functional reserve in isolated organs or systems determines clinical manifestations as the age-related chronic diseases while multisystemic dysfunction results in the frailty phenotype. In older adults, frailty, but not age, is associated with elevation of oxidative stress markers and reduction of antioxidant parameters. Mitochondrial dysfunction related to oxidative stress plays a prominent role in this process affecting not only skeletal muscle but also other potential tissues and organs. Increasing endogenous antioxidant capacity in different systems by exercise outstand among therapeutic interventions with potential ability to prevent or delay frailty phenotype and to promote healthy aging.

Short-term pharmacological activation of Nrf2 ameliorates vascular dysfunction in aged rats and in pathological human vasculature. A potential target for therapeutic intervention.

Oxidative stress contributes to endothelial dysfunction, a key step in cardiovascular disease development. Ageing-related vascular dysfunction involves defective antioxidant response. Nuclear factor erythroid 2-like-2 (Nrf2), orchestrates cellular response to oxidative stress. We evaluated the impact of Nrf2-activation on endothelium-dependent and H2O2-mediated vasodilations in: aorta (RA), mesenteric artery (RMA), coronary artery (RCA) and corpus cavernosum (RCC) from ageing rats and in human penile arteries (HPRA) and corpus cavernosum (HCC) from erectile dysfunction (ED) patients. Relaxant responses were evaluated in organ chambers and wire myographs. Nrf2 content and heme oxygenase-1 (HO-1) were determined by ELISA. Superoxide and Nrf2 were detected by immunofluorescence. Pharmacological activation of Nrf2 with sulforaphane (SFN) improved NO- and endothelium-derived hyperpolarizing factor-mediated endothelium-dependent vasodilation and H2O2-induced relaxation in vascular beds from aging rats. SFN-induced effects were associated with increased Nrf2 (RMA, RCA) and reduced superoxide detection in RCA. Improvement of vascular function was confirmed in HPRA and HCC from ED patients and mimicked by another Nrf2 activator, oltipraz. Nrf2 increase and superoxide reduction together with HO-1 increase by Nrf2 activation was evidenced in HCC from ED patients. PDE5 inhibitor-induced relaxations of HPRA and HCC from ED patients were enhanced by SFN. Nrf2 short-term pharmacological activation attenuates age-related impairment of endothelium-dependent and reactive oxygen species (ROS)-induced vasodilation in different rat and human vascular territories by upregulation of Nrf2-related signaling and decreased oxidative stress. In ED patients target tissues, Nrf2 potentiates the functional effect of ED conventional pharmacological therapy suggesting potential therapeutic implication.

Better Nutritional Status Is Positively Associated with mRNA Expression of SIRT1 in Community-Dwelling Older Adults in the Toledo Study for Healthy Aging.

Background: The expression of certain genes involved in response to oxidative stress is likely related to aging-related outcomes, such as frailty in old age. Given nutrition's substantial impact in aging and age-related diseases, one of its mechanisms might be through influencing gene expression. Objective: This study aimed to investigate the association between nutrition and the expression of 15 genes related to cellular response to stress in older community-dwelling individuals. Methods: A nested case-control study of 350 participants (mean ± SEM age: 76.5 ± 6.9 y, 42.9% men, 22% frail according to Fried's criteria) was selected from the Toledo Study for Healthy Aging. Blood-derived RNA was retro-transcribed into complementary DNA. TaqMan Arrays were used for determining gene expression. The Mini Nutritional Assessment (MNA) and the PREDIMED (PREvención con DIeta MEDiterranea) questionnaire measured nutritional status and adherence to the Mediterranean diet (MD), respectively. Data were reweighed so that inference from linear and logistic regression models applied to the original sampling population. Results: Higher MNA scores were associated with higher expressions of the gene coding for sirtuin-1 (SIRT1), regardless of age, sex, and Charlson comorbidity score (P = 0.04) and even after adjusting for frailty status (P = 0.016) and level of adherence to the MD (P = 0.04). Malnutrition risk and SIRT1 gene expression were inversely associated (P = 0.0045) independently of frailty status (P = 0.0045) and level of adherence to the MD (P = 0.0075). Conclusions: In older individuals, improvement in nutritional status is positively associated with SIRT1 gene expression independently of frailty status or adherence to the MD. These findings may provide potential biomarkers and targets for health interventions among the elderly.

Multivessel analysis of progressive vascular aging in the rat: Asynchronous vulnerability among vascular territories.

Aging induces vascular dysfunction, representing the major risk factor for cardiovascular disease. Our aim was to ascertain specific vulnerability of vascular territories to aging by evaluating the progressive impact of aging on vascular function in four different vascular beds: aorta, mesenteric artery (MA), coronary artery (CA), and penile corpus cavernosum (CC) from 3, 6, 9, 12, 20 or 24 months-old male rats. Contractile/relaxant responses were evaluated in organ chambers (A/CC) and wire myographs (MA/CA). Relationships of systemic biomarkers with endothelial function impairment were also determined. Although all vessels manifested aging-related impairment in endothelial vasodilation, CA was the most impacted by aging considering the onset (at 6 months) and magnitude of endothelial dysfunction (reduction by 1.5 log units in the concentration required for 50% of maximal relaxation for acetylcholine). H2O2-induced vasodilations were progressively reduced by aging in aorta, CC and CA while NO-donor-induced vasodilation was impaired by aging only in CA. Serum asymmetric dimethylarginine significantly correlated to endothelial decline in aorta, MA, and CC, while HOMA-IR was significantly associated with endothelial dysfunction in CA and MA. CA are especially vulnerable to aging-related vascular dysfunction. Correlations of vascular dysfunction with systemic biomarkers differ among vessels, further suggesting heterogeneity in aging-induced vascular impact.

Haemostatic agent etamsylate in vitro and in vivo antagonizes anti-coagulant activity of heparin.

Etamsylate is indicated for several anti-hemorrhagic indications in human and veterinary medicine. However, etamsylate has been shown to be effective only in specific hemorrhagic situations. Furthermore, mechanism of action of etamsylate is not known but recent research has shown its ability to inhibit heparin binding to several growth factors. We have evaluated the ability of etamsylate to interfere with the activities of heparin. Effects of etamsylate on vasodilatory activity of heparin were evaluated in rat aortic segments. Influence of etamsylate on anticoagulant activity of heparin was evaluated in vitro by determining prothrombin (PT) time and activated partial thromboplastin time (aPTT) in dog blood and in vivo by determining the interference of systemic and topical etamsylate on heparin-induced extension in bleeding time (BT) in rats. Despite failing to inhibit heparin-induced vasodilation of rat aorta, etamsylate significantly reduced the increase in aPTT caused by heparin (+30.4 ±â€¯6.7% vs. +15.0 ±â€¯2.8% for etamsylate at 100 µM, P < 0.05). Etamsylate also antagonized the anticoagulant effects driven by heparin in vivo since prevented the heparin-induced increase in BT when systemically (i.p.) administered (+94.6 ±â€¯7.5% vs. +57.9 ±â€¯9.2% at 10 mg/kg, P < 0.05, vs. +22.2 ±â€¯16.8% at 30 mg/kg, P < 0.01). Additionally, topically applied etamsylate (125 mg/ml) significantly reduced heparin-induced BT increase (+102.5 ±â€¯3.2% vs. +54.0 ±â€¯5.8%, P < 0.01). These evidences show a pharmacological interference by etamsylate on heparin activities antagonizing pro-hemorrhagic effects of heparin in vitro and in vivo without inhibiting its vasodilatory properties. This ability could help to explain pharmacological effects of etamsylate and proposes its role for reversing pro-hemorrhagic states.

Frailty Is Associated With Lower Expression of Genes Involved in Cellular Response to Stress: Results From the Toledo Study for Healthy Aging.

BACKGROUND: Specific mechanisms underlying frailty syndrome are not well known. Frailty can be viewed as a loss of functional reserve resulting in increased vulnerability to stressors. We hypothesize that pathways regulating cellular response to stress are potential players in the development of frailty. The aim of this study was to evaluate the association of the expression of certain genes related to cellular response to stress with the presence of frailty in older patients. METHODS: A sample of 350 individuals aged 65 years or older (22% frail) was selected from the Toledo Study of Healthy Aging. RNA was extracted from blood and retro-transcribed into complementary DNA. TaqMan Low density Arrays were used for the measurement of expression of genes implicated in cellular response to oxidative stress, genes implicated in inflammation, genes implicated in vascular physiology, and genes related to hypoxia. For data analysis, a logistic regression model was used to assess the relationship of gene expression and frailty. RESULTS: Among the analyzed genes, lower expression of genes related to cellular response to hypoxia (hypoxia inducible factor-1α) or to cellular response to oxidative stress (nuclear factor erythroid 2-related factor 2 and its target genes heme oxygenase-2, thioredoxin reductase-1, and superoxide dismutase-2), but not to those related to inflammation or vascular physiology, were significantly associated with the presence of frailty after adjustment for age and sex. These associations remained significant after adjustment by type 2 diabetes and Charlson index of comorbidities. Lower expressions of genes involved in cellular response to stress were also associated with increased risk of functional impairment. CONCLUSIONS: Reduced expression of several genes implicated in cellular response to oxidative stress or hypoxia is significantly associated with the presence of frailty. These results help to fill the gap of knowledge of this evolving field and provide targets for intervention to promote health and independence in the elderly.