Age intrinsic loss of telomere protection via TRF1 reduction in endothelial cells

α-Terpineol Induces Shelterin Components TRF1 and TRF2 to Mitigate Senescence and Telomere Integrity Loss via A Telomerase-Independent Pathway

Cellular senescence is a hallmark of aging characterized by irreversible growth arrest and functional decline. Progressive telomeric DNA shortening in dividing somatic cells, programmed during development, leads to critically short telomeres that trigger replicative senescence and thereby contribute to aging. Therefore, protecting telomeres from DNA damage is essential in order to avoid entry into senescence and organismal aging. In several organisms, including mammals, telomeres are protected by a protein complex named shelterin that prevents DNA damage at the chromosome ends through the specific function of its subunits. Here, we reveal that the nuclear protein levels of shelterin components TRF1 and TRF2 decline in fibroblasts reaching senescence. Notably, we identify α-terpineol as an activator that effectively enhances TRF1 and TRF2 levels in a telomerase-independent manner, counteracting the senescence-associated decline in these crucial proteins. Moreover, α-terpineol ameliorates the cells' response to oxidative DNA damage, particularly at the telomeric regions, thus preserving telomere length and delaying senescence. More importantly, our findings reveal the significance of the PI3K/AKT pathway in the regulation of shelterin components responsible for preserving telomere integrity. In conclusion, this study deepens our understanding of the molecular pathways involved in senescence-associated telomere dysfunction and highlights the potential of shelterin components to serve as targets of therapeutic interventions, aimed at promoting healthy aging and combating age-related diseases.

The Implications of Aging on Vascular Health

Vascular aging encompasses structural and functional changes in the vasculature, significantly contributing to cardiovascular diseases, which are the leading cause of death globally. The incidence and prevalence of these diseases increase with age, with most morbidity and mortality attributed to myocardial infarction and stroke. Diagnosing and intervening in vascular aging while understanding the mechanisms behind age-induced vascular phenotypic and pathophysiological alterations offers the potential for delaying and preventing cardiovascular mortality in an aging population. This review delves into various aspects of vascular aging by examining age-related changes in arterial health at the cellular level, including endothelial dysfunction, cellular senescence, and vascular smooth muscle cell transdifferentiation, as well as at the structural level, including arterial stiffness and changes in wall thickness and diameter. We also explore aging-related changes in perivascular adipose tissue deposition, arterial collateralization, and calcification, providing insights into the physiological and pathological implications. Overall, aging induces phenotypic changes that augment the vascular system's susceptibility to disease, even in the absence of traditional risk factors, such as hypertension, diabetes, obesity, and smoking. Overall, age-related modifications in cellular phenotype and molecular homeostasis increase the vulnerability of the arterial vasculature to structural and functional alterations, thereby accelerating cardiovascular risk. Increasing our understanding of these modifications is crucial for success in delaying or preventing cardiovascular diseases. Non-invasive techniques, such as measuring carotid intima-media thickness, pulse wave velocity, and flow-mediated dilation, as well as detecting vascular calcifications, can be used for the early detection of vascular aging. Targeting specific pathological mechanisms, such as cellular senescence and enhancing angiogenesis, holds promise for innovative therapeutic approaches.

Roles of chromatin and genome instability in cellular senescence and their relevance to ageing and related diseases

Ageing is a complex biological process in which a gradual decline in physiological fitness increases susceptibility to diseases such as neurodegenerative disorders and cancer. Cellular senescence, a state of irreversible cell-growth arrest accompanied by functional deterioration, has emerged as a pivotal driver of ageing. In this Review, we discuss how heterochromatin loss, telomere attrition and DNA damage contribute to cellular senescence, ageing and age-related diseases by eliciting genome instability, innate immunity and inflammation. We also discuss how emerging therapeutic strategies could restore heterochromatin stability, maintain telomere integrity and boost the DNA repair capacity, and thus counteract cellular senescence and ageing-associated pathologies. Finally, we outline current research challenges and future directions aimed at better comprehending and delaying ageing.

Inflammaging: Expansion of Molecular Phenotype and Role in Age-Associated Female Infertility

Cellular aging is considered as one of the main factors implicated in female infertility. We evaluated the expression of senescence-associated secretory phenotype (SASP) markers and additional molecular factors in an in vitro model of cellular aging. We induced genotoxic stress (UVB/UVA ray irradiation) in primary human endometrial cells obtained from female subjects of young reproductive age (<35 years of age). We assessed the expression levels of IL-6, IL-8, IL-1α, MMP3, SIRT-1, SIRT-6, TERF-1, and CALR at the mRNA level by RT-qPCR and at the protein level by immunofluorescence and confocal microscopy in primary human endometrial cells upon induction of genotoxic stress and compared them to untreated cells. Statistically significant differences were found for the expression of SIRT-1, SIRT-6, and TERF, which were found to be decreased upon induction of cell senescence through genotoxic stress, while IL-6, IL-8, IL-1α, MMP3, and p16 were found to be increased in senescent cells. We propose that these molecules, in addition to SAS-linked factors, could represent novel markers, and eventually potential therapeutic targets, for the aging-associated dysfunction of the female reproductive system.

Mitochondrial Quality Control in Ovarian Function: From Mechanisms to Therapeutic Strategies

Mitochondrial quality control plays a critical role in cytogenetic development by regulating various cell-death pathways and modulating the release of reactive oxygen species (ROS). Dysregulated mitochondrial quality control can lead to a broad spectrum of diseases, including reproductive disorders, particularly female infertility. Ovarian insufficiency is a significant contributor to female infertility, given its high prevalence, complex pathogenesis, and profound impact on women's health. Understanding the pathogenesis of ovarian insufficiency and devising treatment strategies based on this understanding are crucial. Oocytes and granulosa cells (GCs) are the primary ovarian cell types, with GCs regulated by oocytes, fulfilling their specific energy requirements prior to ovulation. Dysregulation of mitochondrial quality control through gene knockout or external stimuli can precipitate apoptosis, inflammatory responses, or ferroptosis in both oocytes and GCs, exacerbating ovarian insufficiency. This review aimed to delineate the regulatory mechanisms of mitochondrial quality control in GCs and oocytes during ovarian development. This study highlights the adverse consequences of dysregulated mitochondrial quality control on GCs and oocyte development and proposes therapeutic interventions for ovarian insufficiency based on mitochondrial quality control. These insights provide a foundation for future clinical approaches for treating ovarian insufficiency.

Molecular mechanisms of aging and anti-aging strategies

Aging is a complex and multifaceted process involving a variety of interrelated molecular mechanisms and cellular systems. Phenotypically, the biological aging process is accompanied by a gradual loss of cellular function and the systemic deterioration of multiple tissues, resulting in susceptibility to aging-related diseases. Emerging evidence suggests that aging is closely associated with telomere attrition, DNA damage, mitochondrial dysfunction, loss of nicotinamide adenine dinucleotide levels, impaired macro-autophagy, stem cell exhaustion, inflammation, loss of protein balance, deregulated nutrient sensing, altered intercellular communication, and dysbiosis. These age-related changes may be alleviated by intervention strategies, such as calorie restriction, improved sleep quality, enhanced physical activity, and targeted longevity genes. In this review, we summarise the key historical progress in the exploration of important causes of aging and anti-aging strategies in recent decades, which provides a basis for further understanding of the reversibility of aging phenotypes, the application prospect of synthetic biotechnology in anti-aging therapy is also prospected.

Associations of measured and genetically predicted leukocyte telomere length with vascular phenotypes: a population-based study

Shorter leukocyte telomere length (LTL) is associated with cardiovascular dysfunction. Whether this association differs between measured and genetically predicted LTL is still unclear. Moreover, the molecular processes underlying the association remain largely unknown. We used baseline data of the Rhineland Study, an ongoing population-based cohort study in Bonn, Germany [56.2% women, age: 55.5 ± 14.0 years (range 30 - 95 years)]. We calculated genetically predicted LTL in 4180 participants and measured LTL in a subset of 1828 participants with qPCR. Using multivariable regression, we examined the association of measured and genetically predicted LTL, and the difference between measured and genetically predicted LTL (ΔLTL), with four vascular functional domains and the overall vascular health. Moreover, we performed epigenome-wide association studies of three LTL measures. Longer measured LTL was associated with better microvascular and cardiac function. Longer predicted LTL was associated with better cardiac function. Larger ΔLTL was associated with better microvascular and cardiac function and overall vascular health, independent of genetically predicted LTL. Several CpGs were associated (p < 1e-05) with measured LTL (n = 5), genetically predicted LTL (n = 8), and ΔLTL (n = 27). Genes whose methylation status was associated with ΔLTL were enriched in vascular endothelial signaling pathways and have been linked to environmental exposures, cardiovascular diseases, and mortality. Our findings suggest that non-genetic causes of LTL contribute to microvascular and cardiac function and overall vascular health, through an effect on the vascular endothelial signaling pathway. Interventions that counteract LTL may thus improve vascular function.

Cardiovascular aging: spotlight on mitochondria

Mitochondria are cellular organelles critical for ATP production and are particularly relevant to cardiovascular diseases including heart failure, atherosclerosis, ischemia-reperfusion injury, and cardiomyopathies. With advancing age, even in the absence of clinical disease, mitochondrial homeostasis becomes disrupted (e.g., redox balance, mitochondrial DNA damage, oxidative metabolism, and mitochondrial quality control). Mitochondrial dysregulation leads to the accumulation of damaged and dysfunctional mitochondria, producing excessive reactive oxygen species and perpetuating mitochondrial dysfunction. In addition, mitochondrial DNA, cardiolipin, and N-formyl peptides are potent activators of cell-intrinsic and -extrinsic inflammatory pathways. These age-related mitochondrial changes contribute to the development of cardiovascular diseases. This review covers the impact of aging on mitochondria and links these mechanisms to therapeutic implications for age-associated cardiovascular diseases.

Lactoferrin improves symptoms of dextran sulfate sodium-induced colitis in mice through modulation of cellular senescence

The multifaceted effects of lactoferrin (LF) on the digestive and immune systems make it an attractive therapeutic option in inflammatory bowel diseases. In this study, we aimed to explore the anti-inflammatory effects of LF in colitis, particularly in relation to cellular senescence. We hypothesize that LF has the potential to modulate the senescence process. The effects of LF on senescence were tested in vitro using HCT116 and SW480 cell lines, and in vivo, the dextran sulfate sodium-induced mouse model of colitis. LF (500 mg/kg) alleviated symptoms of colitis in mice with a significant decrease in colon damage (P < .0001 vs. control) and microscopic (P < .05 vs. control) scores. Cellular senescence markers p16 and p21 were significantly upregulated in the mouse colon during inflammation (both P < .01 vs. control), and LF at 500 mg/kg decreased these markers (both P < .05 vs. dextran sulfate sodium-treated mice). In vitro, LF significantly affected the expression of p16 and p21 (P < .05-P < .0001 vs. control), senescence associated secretory phenotype (P < .01-P < .0001 vs. control), and telomere-specific proteins: telomeric repeat binding factor 1 and 2 (P < .05-P < .0001 vs. control) in a concentration-dependent manner. LF modulates the expression of cellular senescence markers and shows hallmarks of senolytic and pro-senescent activity, depending on dose. Further studies are needed to fully understand the anti-inflammatory effect of LF in the context of senescence and safe utilization in patients with inflammatory bowel diseases.

Effects of nanomaterial exposure on telomere dysfunction, hallmarks of mammalian and zebrafish cell senescence, and zebrafish mortality

Environmental and occupational exposure to hazardous substances accelerates biological aging. However, the toxic effects of nanomaterials on telomere and cellular senescence (major hallmarks of the biological aging) remained controversial. This study was to synthesize all published evidence to explore the effects of nanomaterial exposure on the telomere change, cellular senescence and mortality of model animals. Thirty-five studies were included by searching electronic databases (PubMed, Embase and Web of Science). The pooled analysis by Stata 15.0 software showed that compared with the control, nanomaterial exposure could significantly shorten the telomere length [measured as kbp: standardized mean difference (SMD) = -1.88; 95% confidence interval (CI) = -3.13 - - 0.64; % of control: SMD = -1.26; 95%CI = -2.11- - 0.42; < 3 kbp %: SMD = 5.76; 95%CI = 2.92 - 8.60), increase the telomerase activity (SMD = -1.00; 95%CI = -1.74 to -0.26), senescence-associated β-galactosidase levels in cells (SMD = 8.20; 95%CI = 6.05 - 10.34) and zebrafish embryos (SMD = 7.32; 95%CI = 4.70 - 9.94) as well as the mortality of zebrafish (SMD = 3.83; 95%CI = 2.94 - 4.72)]. The expression levels of telomerase TERT, shelterin components (TRF1, TRF2 and POT1) and senescence biomarkers (p21, p16) were respectively identified to be decreased or increased in subgroup analyses. In conclusion, this meta-analysis demonstrates that nanomaterial exposure is associated with telomere attrition, cell senescence and organismal death.

New Dawn for Atherosclerosis: Vascular Endothelial Cell Senescence and Death

Endothelial cells (ECs) form the inner linings of blood vessels, and are directly exposed to endogenous hazard signals and metabolites in the circulatory system. The senescence and death of ECs are not only adverse outcomes, but also causal contributors to endothelial dysfunction, an early risk marker of atherosclerosis. The pathophysiological process of EC senescence involves both structural and functional changes and has been linked to various factors, including oxidative stress, dysregulated cell cycle, hyperuricemia, vascular inflammation, and aberrant metabolite sensing and signaling. Multiple forms of EC death have been documented in atherosclerosis, including autophagic cell death, apoptosis, pyroptosis, NETosis, necroptosis, and ferroptosis. Despite this, the molecular mechanisms underlying EC senescence or death in atherogenesis are not fully understood. To provide a comprehensive update on the subject, this review examines the historic and latest findings on the molecular mechanisms and functional alterations associated with EC senescence and death in different stages of atherosclerosis.

Premature senescence and cardiovascular disease following cancer treatments: mechanistic insights

Cardiovascular disease (CVD) is a leading cause of morbidity and mortality, especially among the aging population. The "response-to-injury" model proposed by Dr. Russell Ross in 1999 emphasizes inflammation as a critical factor in atherosclerosis development, with atherosclerotic plaques forming due to endothelial cell (EC) injury, followed by myeloid cell adhesion and invasion into the blood vessel walls. Recent evidence indicates that cancer and its treatments can lead to long-term complications, including CVD. Cellular senescence, a hallmark of aging, is implicated in CVD pathogenesis, particularly in cancer survivors. However, the precise mechanisms linking premature senescence to CVD in cancer survivors remain poorly understood. This article aims to provide mechanistic insights into this association and propose future directions to better comprehend this complex interplay.

MicroRNA miR-214-5p induces senescence of microvascular endothelial cells by targeting the JAG1/Notch signaling pathway

During cellular senescence, irreversible cell cycle arrest is accompanied by morphological and genetic alterations. MicroRNAs (miRNAs) play a critical role in regulating senescence by modulating the abundance of crucial senescence regulatory proteins. Therefore, to identify novel senescence-associated miRNAs, we analyzed differentially expressed miRNAs in microvascular endothelial cells (MVEC). Among the 80 differentially expressed miRNAs in replicative senescent MVECs, 16 miRNAs of unknown gene ontology were used in the senescence-associated β-galactosidase assay. Thus, we identified miR-214-5p as having high senescence-inducing activity, inhibiting the proliferation and angiogenesis activity of MVECs. To reveal the senescence-regulating mechanism of miR-214-5p, we searched for target genes through sequence- and literature-based analysis. Molecular manipulation of miR-214-5p demonstrated that miR-214-5p regulated the expression and function of Jagged 1 (JAG1) in senescent MVECs. Silencing JAG1 or downstream genes of JAG1-Notch signaling, accelerated the senescence of MVECs. Additionally, ectopic overexpression of JAG1 reversed the senescence-inducing activity of miR-214-5p. In conclusion, we identified miR-214-5p as a senescence-associated miRNA. Targeting miR-214-5p may be a potential strategy to delay vascular aging and overcome the detrimental effects of senescence and age-related diseases.

Possible molecular mechanisms underlying the development of atherosclerosis in cancer survivors

Cancer survivors undergone treatment face an increased risk of developing atherosclerotic cardiovascular disease (CVD), yet the underlying mechanisms remain elusive. Recent studies have revealed that chemotherapy can drive senescent cancer cells to acquire a proliferative phenotype known as senescence-associated stemness (SAS). These SAS cells exhibit enhanced growth and resistance to cancer treatment, thereby contributing to disease progression. Endothelial cell (EC) senescence has been implicated in atherosclerosis and cancer, including among cancer survivors. Treatment modalities for cancer can induce EC senescence, leading to the development of SAS phenotype and subsequent atherosclerosis in cancer survivors. Consequently, targeting senescent ECs displaying the SAS phenotype hold promise as a therapeutic approach for managing atherosclerotic CVD in this population. This review aims to provide a mechanistic understanding of SAS induction in ECs and its contribution to atherosclerosis among cancer survivors. We delve into the mechanisms underlying EC senescence in response to disturbed flow and ionizing radiation, which play pivotal role in atherosclerosis and cancer. Key pathways, including p90RSK/TERF2IP, TGFβR1/SMAD, and BH4 signaling are explored as potential targets for cancer treatment. By comprehending the similarities and distinctions between different types of senescence and the associated pathways, we can pave the way for targeted interventions aim at enhancing the cardiovascular health of this vulnerable population. The insights gained from this review may facilitate the development of novel therapeutic strategies for managing atherosclerotic CVD in cancer survivors.

Therapeutic opportunities for senolysis in cardiovascular disease

Cellular senescence within the cardiovascular system has, until recently, been understudied and unappreciated as a factor in the development of age-related cardiovascular diseases such as heart failure, myocardial infarction and atherosclerosis. This is in part due to challenges with defining senescence within post-mitotic cells such as cardiomyocytes. However, recent evidence has demonstrated senescent-like changes, including a senescence-associated secretory phenotype (SASP), in cardiomyocytes in response to ageing and cell stress. Other replicating cells, including fibroblasts and vascular smooth muscle cells, within the cardiovascular system have also been shown to undergo senescence and contribute to disease pathogenesis. These findings coupled with the emergence of senolytic therapies, to target and eliminate senescent cells, have provided fascinating new avenues for management of several age-related cardiovascular diseases with high prevalence. In this review, we discuss the role of senescent cells within the cardiovascular system and highlight the contribution of senescence cells to common cardiovascular diseases. We discuss the emerging role for senolytics in cardiovascular disease management while highlighting important aspects of senescence biology which must be clarified before the potential of senolytics can be fully realized.

Extracellular Vesicles and Cardiac Aging

Global population aging is a major challenge to health and socioeconomic policies. The prevalence of diseases progressively increases with aging, with cardiovascular disease being the major cause of mortality among elderly people. The allostatic overload imposed by the accumulation of cardiac senescent cells has been suggested to play a pivotal role in the aging-related deterioration of cardiovascular function. Senescent cells exhibit intrinsic disorders and release a senescence-associated secretory phenotype (SASP). Most of these SASP compounds and damaged molecules are released from senescent cells by extracellular vesicles (EVs). Once secreted, these EVs can be readily incorporated by recipient neighboring cells and elicit cellular damage or otherwise can promote extracellular matrix remodeling. This has been associated with the development of cardiac dysfunction, fibrosis, and vascular calcification, among others. The molecular signature of these EVs is highly variable and might provide important information for the development of aging-related biomarkers. Conversely, EVs released by the stem and progenitor cells can exert a rejuvenating effect, raising the possibility of future anti-aging therapies.

The Aftermath of Long-Term Cigarette Smoking on Telomere Length and Mitochondrial DNA Copy Number in Human Cumulus Cells Prior to In Vitro Fertilization-A Pilot Study

Cigarette smoking among women of reproductive age is known to take a toll on systemic health and fertility potential by severely impacting ovarian tissues and cells, such as granulosa and cumulus cells (CCs). The purpose of this study was to determine the potential damage caused by tobacco smoke at a molecular level in the CCs of females who had undergone in vitro fertilization. The level of intracellular damage was determined by estimating the average telomere length (TL) and mitochondrial DNA copy number (mtDNA-CN), as well as the expression profile of telomere maintenance genes TERF1, TERF2, POT1 and microRNAs miR-155, miR-23a and miR-185. Western blotting analysis was performed to detect consequent protein levels of TERF1, TERF2 and POT1. Our results evidenced significantly lower relative TL and mtDNA-CN and a down-regulation pattern for all three described genes and corresponding proteins in the CCs of smokers compared with controls (p < 0.05). No significant differences were found in the miRNAs’ modulation. Combined, our data add another piece to the puzzle of the complex regulatory molecular networks controlling the general effects of tobacco smoke in CCs. This pilot study extends the until now modest number of studies simultaneously investigating the mtDNA-CN and TL pathways in the human CCs of smoking women.

The role of p53 in the alternation of vascular functions

Ageing is a risk factor for many degenerative diseases. Cardiovascular diseases (CVDs) are usually big burdens for elderly, caregivers and the health system. During the aging process, normal functions of vascular cells and tissue progressively lost and eventually develop vascular diseases. Endothelial dysfunction, reduced bioavailability of endothelium-derived nitric oxide are usual phenomena observed in patients with cardiovascular diseases. Myriad of studies have been done to investigate to delay the vascular dysfunction or improve the vascular function to prolong the aging process. Tumor suppressor gene p53, also a transcription factor, act as a gatekeeper to regulate a number of genes to maintain normal cell function including but not limited to cell proliferation, cell apoptosis. p53 also crosstalk with other key transcription factors like hypoxia-inducible factor 1 alpha that contribute to the progression of cardiovascular diseases. Therefore, in recent three decades, p53 has drawn scientists’ attention on its effects in vascular function. Though the role of tumor suppressor gene p53 is still not clear in vascular function, it is found to play regulatory roles and may involve in vascular remodeling, atherosclerosis or pulmonary hypertension. p53 may have a divergent role in endothelial and vascular muscle cells in those conditions. In this review, we describe the different effects of p53 in cardiovascular physiology. Further studies on the effects of endothelial cell-specific p53 deficiency on atherosclerotic plaque formation in common animal models are required before the therapeutic potential can be realized.

Nutritional components as mitigators of cellular senescence in organismal aging: a comprehensive review

The process of cellular senescence is rapidly emerging as a modulator of organismal aging and disease. Targeting the development and removal of senescent cells is considered a viable approach to achieving improved organismal healthspan and lifespan. Nutrition and health are intimately linked and an appropriate dietary regimen can greatly impact organismal response to stress and diseases including during aging. With a renewed focus on cellular senescence, emerging studies demonstrate that both primary and secondary nutritional elements such as carbohydrates, proteins, fatty acids, vitamins, minerals, polyphenols, and probiotics can influence multiple aspects of cellular senescence. The present review describes the recent molecular aspects of cellular senescence-mediated understanding of aging and then studies available evidence of the cellular senescence modulatory attributes of major and minor dietary elements. Underlying pathways and future research directions are deliberated to promote a nutrition-centric approach for targeting cellular senescence and thus improving human health and longevity.

Pharmacologic modulation of intracellular Na + concentration with ranolazine impacts inflammatory response in humans and mice

Inflammation is a key process accompanying cardiovascular disease. Reducing inflammation is therefore an important therapeutic option. We provide evidence, that Na⁺ and Ca²⁺ modulation regulate the inflammatory response. Reducing intracellular Na⁺ pharmacologically using the drug ranolazine reduced the influx of Ca²⁺ during inflammation and thereby reduced the cellular production of inflammatory mediators. Similarly, reduction of extracellular Na⁺ and knockdown of a Na⁺–Ca²⁺ exchanger led to reduced inflammation. Our in vitro finding translated to in vivo experiments as ranolazine treatment led to reduced atherosclerotic plaque growth, increased plaque stability, and diminished inflammation in a mouse model. Finally, we were able to observe the antiinflammatory effect of Na⁺ modulation in human patients, demonstrating that inflammation was reduced after treatment with ranolazine.

Changes in Ca2⁺ influx during proinflammatory stimulation modulates cellular responses, including the subsequent activation of inflammation. Whereas the involvement of Ca²⁺ has been widely acknowledged, little is known about the role of Na⁺. Ranolazine, a piperazine derivative and established antianginal drug, is known to reduce intracellular Na⁺ as well as Ca2⁺ levels. In stable coronary artery disease patients (n = 51) we observed reduced levels of high-sensitive C-reactive protein (CRP) 3 mo after the start of ranolazine treatment (n = 25) as compared to the control group. Furthermore, we found that in 3,808 acute coronary syndrome patients of the MERLIN‐TIMI 36 trial, individuals treated with ranolazine (1,934 patients) showed reduced CRP values compared to placebo-treated patients. The antiinflammatory effects of sodium modulation were further confirmed in an atherosclerotic mouse model. LDL^−/− mice on a high-fat diet were treated with ranolazine, resulting in a reduced atherosclerotic plaque burden, increased plaque stability, and reduced activation of the immune system. Pharmacological Na⁺ inhibition by ranolazine led to reduced express of adhesion molecules and proinflammatory cytokines and reduced adhesion of leukocytes to activated endothelium both in vitro and in vivo. We demonstrate that functional Na⁺ shuttling is required for a full cellular response to inflammation and that inhibition of Na⁺ influx results in an attenuated inflammatory reaction. In conclusion, we demonstrate that inhibition of Na⁺–Ca²⁺ exchange during inflammation reduces the inflammatory response in human endothelial cells in vitro, in a mouse atherosclerotic disease model, and in human patients.

Extracellular Matrix in Aging Aorta

The aging population is booming all over the world and arterial aging causes various age-associated pathologies such as cardiovascular diseases (CVDs). The aorta is the largest elastic artery, and transforms pulsatile flow generated by the left ventricle into steady flow to maintain circulation in distal tissues and organs. Age-associated structural and functional changes in the aortic wall such as dilation, tortuousness, stiffening and losing elasticity hamper stable peripheral circulation, lead to tissue and organ dysfunctions in aged people. The extracellular matrix (ECM) is a three-dimensional network of macromolecules produced by resident cells. The composition and organization of key ECM components determine the structure-function relationships of the aorta and therefore maintaining their homeostasis is critical for a healthy performance. Age-associated remodeling of the ECM structural components, including fragmentation of elastic fibers and excessive deposition and crosslinking of collagens, is a hallmark of aging and leads to functional stiffening of the aorta. In this mini review, we discuss age-associated alterations of the ECM in the aortic wall and shed light on how understanding the mechanisms of aortic aging can lead to the development of efficient strategy for aortic pathologies and CVDs.

Endothelial Senescence and the Chronic Vascular Diseases: Challenges and Therapeutic Opportunities in Atherosclerosis

Atherosclerosis is probably one of the paradigms of disease linked to aging. Underlying the physiopathology of atherosclerosis are cellular senescence, oxidative stress, and inflammation. These factors are increased in the elderly and from chronic disease patients. Elevated levels of oxidative stress affect cellular function and metabolism, inducing senescence. This senescence modifies the cell phenotype into a senescent secretory phenotype. This phenotype activates immune cells, leading to chronic systemic inflammation. Moreover, due to their secretory phenotype, senescence cells present an increased release of highlighted extracellular vesicles that will change nearby/neighborhood cells and paracrine signaling. For this reason, searching for specific senescent cell biomarkers and therapies against the development/killing of senescent cells has become relevant. Recently, senomorphic and senolityc drugs have become relevant in slowing down or eliminating senescence cells. However, even though they have shown promising results in experimental studies, their clinical use is still yet to be determined.

MiRNA Let-7a and Let-7d Are Induced by Globotriaosylceramide via NF-kB Activation in Fabry Disease

BACKGROUND

Fabry disease is a hereditary genetic defect resulting in reduced activity of the enzyme α-galactosidase-A and the accumulation of globotriaosylceramide (Gb3) in body fluids and cells. Gb3 accumulation was especially reported for the vascular endothelium in several organs.

METHODS

Three Fabry disease patients were screened using a micro-RNA screen. An in vitro approach in human endothelial cells was used to determine miRNA regulation by Gb3.

RESULTS

In a micro-RNA screen of three Fabry patients undergoing enzyme replacement therapy, we found that miRNAs let-7a and let-7d were significantly increased after therapy. We demonstrate in vitro in endothelial cells that Gb3 induced activation of NF-κB and activated downstream targets. In addition, NF-κB activity directly reduced let-7a and let-7d miRNA expression as inhibiting NF-kB nuclear entry abolished the Gb3 effects.

CONCLUSION

We suggest that let-7a and let-7d are potential markers for enzyme activity and inflammation in Fabry disease patients.

Pharmacological inhibition of fatty acid oxidation reduces atherosclerosis progression by suppression of macrophage NLRP3 inflammasome activation

BACKGROUND

Inflammation is a key process during atherosclerotic lesion development and propagation. Recent evidence showed clearly that especially the inhibition of interleukin (IL)-1β reduced atherosclerotic adverse events in human patients. Fatty acid oxidation (FAO) was previously demonstrated to interact with the NOD-, LRR- and pyrin domain-containing protein 3 (NLRP3) pathway which is required for mature IL-1β secretion. To understand possible anti-inflammatory properties of FAO inhibition, we tested the effect of pharmacological FAO inhibition using the inhibitor for long-chain 3-ketoacyl coenzyme A thiolase trimetazidine on atherosclerotic plaque development and inflammation.

EXPERIMENTAL APPROACH

The effect of FAO inhibition was determined in LDL-R^-/- male mice on a C57/BL6 background. In vitro effects of trimetazidine treatment were analyzed in human umbilical vein endothelial cells and human monocyte derived macrophages.

KEY RESULTS

We were able to demonstrate that inhibition of FAO reduced atherosclerotic plaque growth. We did not find direct anti-inflammatory properties of trimetazidine in endothelial cells or macrophages in vitro. However, we found that the activation of the NLRP3 system and the secretion of IL-1β were significantly reduced in macrophages after FAO inhibition. These results were confirmed in atherosclerotic lesions of mice treated with trimetazidine as they showed a significant reduction of IL-1β and cleaved caspase-1 in the atherosclerotic lesion as well as of IL-1β and IL-18 in the circulation.

CONCLUSION

Overall, we therefore suggest that the main mechanism of reducing inflammation of trimetazidine and FAO inhibition is the reduction of the NLRP-3 activation leading to reduced levels of the proinflammatory cytokine IL-1β.

Improving Age-Related Cognitive Decline through Dietary Interventions Targeting Mitochondrial Dysfunction

Aging is inevitable and it is one of the major contributors to cognitive decline. However, the mechanisms underlying age-related cognitive decline are still the object of extensive research. At the biological level, it is unknown how the aging brain is subjected to progressive oxidative stress and neuroinflammation which determine, among others, mitochondrial dysfunction. The link between mitochondrial dysfunction and cognitive impairment is becoming ever more clear by the presence of significant neurological disturbances in human mitochondrial diseases. Possibly, the most important lifestyle factor determining mitochondrial functioning is nutrition. Therefore, with the present work, we review the latest findings disclosing a link between nutrition, mitochondrial functioning and cognition, and pave new ways to counteract cognitive decline in late adulthood through diet.

Naked mole rat TRF1 safeguards glycolytic capacity and telomere replication under low oxygen

The naked mole rat (NMR), a long-lived and cancer-resistant rodent, is highly resistant to hypoxia. Here, using robust cellular models wherein the mouse telomeric protein TRF1 is substituted by NMR TRF1 or its mutant forms, we show that TRF1 supports maximal glycolytic capacity under low oxygen, shows increased nuclear localization and association with telomeres, and protects telomeres from replicative stress. We pinpoint this evolutionary gain of metabolic function to specific amino acid changes in the homodimerization domain of this protein. We further find that NMR TRF1 accelerates telomere shortening. These findings reveal an evolutionary strategy to adapt telomere biology for metabolic control under an extreme environment.

Selective Elimination of Osteosarcoma Cell Lines with Short Telomeres by Ataxia Telangiectasia and Rad3-Related Inhibitors

To avoid replicative senescence or telomere-induced apoptosis, cancers employ telomere maintenance mechanisms (TMMs) involving either the upregulation of telomerase or the acquisition of recombination-based alternative telomere lengthening (ALT). The choice of TMM may differentially influence cancer evolution and be exploitable in targeted therapies. Here, we examine TMMs in a panel of 17 osteosarcoma-derived cell lines, defining three separate groups according to TMM and the length of telomeres maintained. Eight were ALT-positive, including the previously uncharacterized lines, KPD and LM7. While ALT-positive lines all showed excessive telomere length, ALT-negative cell lines fell into two groups according to their telomere length: HOS-MNNG, OHSN, SJSA-1, HAL, 143b, and HOS displayed subnormally short telomere length, while MG-63, MHM, and HuO-3N1 displayed long telomeres. Hence, we further subcategorized ALT-negative TMM into long-telomere (LT) and short-telomere (ST) maintenance groups. Importantly, subnormally short telomeres were significantly associated with hypersensitivity to three different therapeutics targeting the protein kinase ataxia telangiectasia and Rad3-related (ATR) (AZD-6738/Ceralasertib, VE-822/Berzoserib, and BAY-1895344) compared to long telomeres maintained via ALT or telomerase. Within 24 h of ATR inhibition, cells with short but not long telomeres displayed chromosome bridges and underwent cell death, indicating a selective dependency on ATR for chromosome stability. Collectively, our work provides a resource to identify links between the mode of telomere maintenance and drug sensitivity in osteosarcoma and indicates that telomere length predicts ATR inhibitor sensitivity in cancer.

Shelterin Complex at Telomeres: Implications in Ageing

Different factors influence the development‎ and control of ageing. It is well known that progressive telomere shorting is one of the molecular mechanisms underlying ageing. The shelterin complex consists of six telomere-specific proteins which are involved in the protection of chromosome ends. More particularly, this vital complex protects the telomeres from degradation, prevents from activation of unwanted repair systems, regulates the activity of telomerase, and has a crucial role in cellular senescent and ageing-related pathologies. This review explores the organization and function of telomeric DNA along with the mechanism of telomeres during ageing, followed by a discussion of the critical role of shelterin components and their changes during ageing.

Folic acid delays age-related cognitive decline in senescence-accelerated mouse prone 8: alleviating telomere attrition as a potential mechanism

The occurrence of telomere attrition in brain may cause senescence and death of neurons, leading to cognitive decline. Folic acid (FA) has been reported to improve cognitive performance in mild cognitive impairment; however, its association with telomere remains unclear. The study aimed to investigate if alleviation of telomere attrition by FA supplementation could act as a potential mechanism to delay age-related cognitive decline in senescence-accelerated mouse prone 8 (SAMP8). Aged SAMP8 mice were assigned to four treatment groups: FAdeficient diet (FA-D) group, FA-normal diet (FA-N) group, low FA-supplemented diet (FA-L) group and high FAsupplemented diet (FA-H) group. There was also an age-matched senescence-accelerated mouse resistant 1 (SAMR1) control group (Con-R), and a young SAMP8 control group (Con-Y). The results demonstrated that FA supplementation delayed age-related cognitive decline and neurodegeneration in SAMP8 mice. Importantly, this effect could be attributed to the alleviated telomere attrition, which might be interpreted by the decreased levels of reactive oxygen species. Additionally, improved telomere integrity stimulated mitochondrial function via telomere-p53-mithondria pathway, consequently delayed neuronal degeneration. In conclusion, we demonstrate that FA supplementation delays age-related neurodegeneration and cognitive decline in SAMP8 mice, in which alleviated telomere attrition could serve as one influential factor in the process.

Reduction of Premature Aging Markers After Gastric Bypass Surgery in Morbidly Obese Patients

Background

Obesity is considered to be a major comorbidity. Obese patients suffer from an increased proinflammatory state associated with a premature aging phenotype including increased secretion of senescence-associated secretory proteins (SASP) and reduced telomere length. Micro-ribonucleic acids (miRNAs) are non-coding RNA molecules that could modify the post-transcriptional process. Several studies have reported associations between miRNAs and metabolic unhealthy conditions.

Aim

To determine if bariatric surgery and the resulting weight loss could reverse the premature aging phenotype.

Methods

We enrolled 58 morbidly obese patients undergoing bariatric surgery. Markers of premature aging including the SASP IL-6, CRP and PAI-1, 7 miRNAs, as well as telomere length and telomere oxidation in mononuclear cells were evaluated.

Results

Patients showed a significant drop of body mass index (BMI; 43.98 ± 3.5 versus 28.02 ± 4.1, p < 0.001). We observed a significant reduction in SASP including a reduction of 55% of plasma IL-6 levels (p = 0 < 0.001), 83% of CRP levels (p = 0.001) and 15% of plasma PAI-1 levels (p < 0.001). Telomere length doubled in the patient cohort (p < 0.001) and was accompanied by a reduction in the telomere oxidation index by 70% (p < 0.001). Telomere length was inversely correlated with telomere oxidation. The aging-associated miRNA miR10a_5p was upregulated significantly (p = 0.039), while the other tested miRNAs showed no difference.

Conclusion

Our data indicate a significant reduction of the proinflammatory SASP after bariatric surgery. We observed an increase in telomere length and reduced oxidative stress at telomeres. miR10a_5p which is downregulated during aging was upregulated after surgery. Overall, bariatric surgery ameliorated the premature aging phenotype.

Age-Related Impairment of Structure and Function of Iliac Artery Endothelium in Rats Is Improved by Elevated Fluid Shear Stress

Background

Aging plays an important role in endothelial dysfunction. Fluid shear stress (FSS) can activate endothelial cells (ECs). Herein, we tested the hypothesis that this endothelial impairment could be improved by elevated FSS (EFSS) in aged rats.

Material/Methods

EFSS was created through ligation of the unilateral common iliac artery in 20-−month-old rats, evaluated by measuring blood flow velocity with Doppler spectrum. The effect of FSS on aged ECs was examined by senescence-associated β-galactosidase (SA-β-Gal) staining, ultrastructural observation, and immunostaining and qPCR analysis of eNOS and SIRT1 expression on both the mRNA and protein levels.

Results

(1) FSS was significantly increased in the right common iliac artery (RCIA) in rats with the ligation of the left common iliac artery (LCIA). (2) SA-β-Gal staining was significantly attenuated by EFSS in the RCIA of aged rats. (3) Ultrastructural observation showed that ECs in the RCIA of normal aged rats became irregular and enlarged, with increasingly polypoid nuclei and fewer mitochondria, whereas ECs in the RCIA of aged rats with LCIA ligation became more prominent and contained more mitochondria. (4) eNOS and SIRT1 expression in the RCIA of aged rats with LCIA ligation was significantly upregulated compared with that in control group rats.

Conclusions

The present study for the first time shows that EFSS has the ability to improve age-related impairment of endothelial structure and functions.

Paracrine Interaction of Cancer Stem Cell Populations Is Regulated by the Senescence-Associated Secretory Phenotype (SASP)

Dyskeratosis congenita is a telomere DNA damage syndrome characterized by defective telomere maintenance, bone marrow failure, and increased head and neck cancer risk. The Pot1b^-/-;Terc^+/- mouse exhibits some features of dyskeratosis congenita, but head and neck cancer was not reported in this model. To model the head and neck cancer phenotype, we created unique Pot1b- and p53-null-mutant models which allow genetic lineage tracing of two distinct stem cell populations. Loss of Pot1b expression depleted stem cells via ATR/Chk1/p53 signaling. Tumorigenesis was inhibited in Pot1b^-/-;p53^+/+ mice due to cellular senescence. Pot1b^-/-;p53^-/- tumors also exhibited senescence, but proliferated and metastasized with expansion of Lgr6⁺ stem cells indicative of senescence-associated secretory phenotype. Selective depletion of the small K15⁺ stem cell fraction resulted in reduction of Lgr6⁺ cells and inhibition of tumorigenesis via senescence. Gene expression studies revealed that K15⁺ cancer stem cells regulate Lgr6⁺ cancer stem cell expansion via chemokine signaling. Genetic ablation of the chemokine receptor Cxcr2 inhibited cancer stem cell expansion and tumorigenesis via senescence. The effects of chemokines were primarily mediated by PI3K signaling, which is a therapeutic target in head and neck cancer. IMPLICATIONS: Paracrine interactions of cancer stem cell populations impact therapeutic options and patient outcomes.

Are Routine Postoperative Laboratory Tests Really Necessary After Lumbar Spinal Surgery?

BACKGROUND

For patients undergoing lumbar spinal surgery, many surgeons routinely perform laboratory tests within 3 days after surgery. However, few studies have reported the necessity for routine laboratory tests for patients with uncomplicated cases within 3 days after surgery.

METHODS

We performed a retrospective study of patients with lumbar degenerative disease who had undergone lumbar spinal surgery from May 2014 to May 2017. The perioperative patient information was recorded. The abnormal postoperative laboratory tests were recorded. Finally, the incidence and risk factors for patients requiring postoperative clinical treatment were analyzed.

RESULTS

A total of 1915 patients were included in the present study. Postoperative laboratory tests had been ordered for 870 patients (45.43%). Of these patients, only a small proportion had required postoperative clinical intervention to treat abnormal serum hemoglobin (2.53%), albumin (1.95%), serum potassium (0.92%), or serum calcium (6.55%) levels. Multivariate logistic regression analysis showed that female gender and operative time were risk factors for the need for blood transfusion after lumbar spinal surgery. Age and operative time were risk factors for patients requiring albumin supplementation after lumbar spinal surgery. Finally, intraoperative blood loss and operative time were independent risk factors for patients requiring calcium supplementation after surgery.

CONCLUSIONS

Owing to the small number of postoperative clinical interventions for abnormal laboratory test results, we believe that the use of routine laboratory tests within 3 days after lumbar spinal surgery for patients with uncomplicated cases are unnecessary. Our results showed that operative time is a potential risk factor for the necessity for clinical treatment after lumbar spinal surgery.

Mouse models in modeling aging and cancer

Mouse models have been widely used in the research of human diseases. Aging, just as cancer, is influenced by the interaction of various genetic and environmental factors. Currently, aging could be induced by many mechanism, including telomere dysfunction, oxidase stress, DNA damage and epigenetic changes. Many of these genetic pathways are also shared by aging and cancer. The mouse models generated to study these pathways might manifest either aging or cancer phenotypes, sometimes both, which in deed has worked as a good model system in understanding the correlation between aging and cancer. Here, we reviewed these mouse models that were generated to model aging or cancer. These mouse models might help us put those related pathways in context and discover essential interactions in cancer and aging regulation.

Telomere-dependent and telomere-independent roles of RAP1 in regulating human stem cell homeostasis

RAP1 is a well-known telomere-binding protein, but its functions in human stem cells have remained unclear. Here we generated RAP1-deficient human embryonic stem cells (hESCs) by using CRISPR/Cas9 technique and obtained RAP1-deficient human mesenchymal stem cells (hMSCs) and neural stem cells (hNSCs) via directed differentiation. In both hMSCs and hNSCs, RAP1 not only negatively regulated telomere length but also acted as a transcriptional regulator of RELN by tuning the methylation status of its gene promoter. RAP1 deficiency enhanced self-renewal and delayed senescence in hMSCs, but not in hNSCs, suggesting complicated lineage-specific effects of RAP1 in adult stem cells. Altogether, these results demonstrate for the first time that RAP1 plays both telomeric and nontelomeric roles in regulating human stem cell homeostasis.

The role of senescence, telomere dysfunction and shelterin in vascular aging

In the United States and other westernized nations, CVDs are the leading cause of death in adults over 65 years of age. Large artery stiffness and endothelial dysfunction are increased with age and age-associated arterial dysfunction is an important antecedent of CVDs. One age-associated change that may contribute to vascular dysfunction and CVD risk is an increase in the number of resident senescent cells in the vasculature. Senescent cells display a pro-oxidant, pro-inflammatory phenotype known as the SASP. However, the mechanisms that drive the SASP and the vascular aging phenotype remain elusive. A putative mechanism is the involvement of oxidative stress and inflammation in telomere function. Telomeres are the end caps of chromosomes which are maintained by a six-protein complex known as shelterin. Disruption of shelterin can uncap telomeres and induce cellular senescence. Accordingly, in this review, we propose that oxidative stress and inflammation disrupt shelterin in vascular cells, driving telomere dysfunction and that this mechanism may be responsible for the induction of SASP. The proposed mechanisms may represent some of the initial changes that lead to vascular dysfunction in advanced age.

Endothelial cell senescence in aging-related vascular dysfunction

Increased cardiovascular disease in aging is partly a consequence of the vascular endothelial cell (EC) senescence and associated vascular dysfunction. In this contest, EC senescence is a pathophysiological process of structural and functional changes including dysregulation of vascular tone, increased endothelium permeability, arterial stiffness, impairment of angiogenesis and vascular repair, and a reduction of EC mitochondrial biogenesis. Dysregulation of cell cycle, oxidative stress, altered calcium signaling, hyperuricemia, and vascular inflammation have been implicated in the development and progression of EC senescence and vascular disease in aging. A number of abnormal molecular pathways are associated with these underlying pathophysiological changes including Sirtuin 1, Klotho, fibroblast growth factor 21, and activation of the renin angiotensin-aldosterone system. However, the molecular mechanisms of EC senescence and associated vascular impairment in aging are not completely understood. This review provides a contemporary update on molecular mechanisms, pathophysiological events, as well functional changes in EC senescence and age-associated cardiovascular disease. This article is part of a Special Issue entitled: Genetic and epigenetic regulation of aging and longevity edited by Jun Ren & Megan Yingmei Zhang.

Statin treatment reduces matrix degradation capacity of proinflammatory polarized macrophages

BACKGROUND AND AIMS

Macrophages are versatile immune cells involved in tissue degradation and remodeling. Proinflammatory macrophages have the highest capacity of matrix degradation and proteolysis. Within atherosclerotic lesions, proinflammatory macrophages are associated with unstable plaques. Statins have been demonstrated to increase plaque stability. Possible changes of polarized macrophage tissue degradation behavior under statin treatment are currently unknown.

METHODS

Polarized macrophages were tested in vitro for matrix degradation capacity with or without statin treatment.

RESULTS

Proinflammatory macrophages show high matrix degradation capacity, which is lost after statin treatment. Statin concentrations were within a physiological range and did not influence overall macrophage polarization. Proinflammatory macrophages showed however a loss of filopodia where activators of MMPs are located. Loss of matrix degradation in proinflammatory macrophages was associated with changes of MMP14 activation and loss of uPAR localization at filopodia. Supplementation of mevalonate restored localization of uPAR to cellular protrusions and matrix degradation capacity.

CONCLUSION

Statins reduce the matrix degradation potential of proinflammatory macrophages by reducing uPAR localization to cellular filopodia and reducing intracellular MMP14 activation.

Shelterin differentially respond to oxidative stress induced by TiO2-NPs and regulate telomere length in human hepatocytes and hepatocarcinoma cells in vitro

Titanium dioxide nanoparticles (TiO₂-NPs) have raised serious attention for their widely use and potential adverse effects on human mainly due to producing ROS. However, the influence of TiO₂-NPs on telomere maintaining has not been studied clearly. Shelterin plays core roles in telomere length (TL) regulation. Abnormal TL are associated with chromosome instability (CIN) and high risk of diseases. This study investigated whether TiO₂-NPs affect TL to induce CIN through ROS generation and the possible mechanisms. Human hepatocyte L-02 and hepatocarcinoma cells QGY were exposed to TiO₂-NPs (0, 40, 80 μg/mL) for 72 h. The intracellular hydrogen dioxide (H₂O₂) concentration were measured. The TL, Nrf-2, and three core shelterin components (TRF1, TRF2, and POT1) transcription level were determined by quantitative real-time PCR. CIN was measured by cytokinesis-block micronucleus assay. TiO₂-NPs exposure increased intracellular H₂O₂ in both L-02 and QGY cells, and induced Nrf-2, TRF1, TRF2, POT1 downregulated transcription compared with control (P < 0.001) in L-02 but all upregulated (P < 0.05) in QGY. Significant TL shortening (P < 0.001) and CIN increase (P < 0.01) in L-02 cells were observed but not in QGY cells. The differentially responses of the tested components of shelterin and Nrf-2 to oxidative stress induced by TiO₂-NPs led to the weakened telomere protection in normal cells and effective telomere maintenance in cancer cells, respectively. The upregulation of Nrf-2 and shelterin could protect TL and chromosome stability against TiO₂-NPs exposure.

Urokinase plasminogen activator protects cardiac myocytes from oxidative damage and apoptosis via hOGG1 induction

The role of uPA in tissue remodeling and cell migration is already well established. In addition, uPA was reported to stabilize p53, a key cell cycle control, DNA repair and apoptosis initiation protein. We aimed to determine the role of uPA-uPAR signaling towards cell survival or apoptosis in human adult cardiac myocytes (HACM). HACM were stimulated with uPA and DNA damage was inflicted by incubating cells with 200 µM H₂O₂. To analyze for apoptotic cells we applied TUNEL staining. Oxidative damage foci were analyzed by staining for 8-oxoguanine base pairs. In vivo qPCR analysis from RNA extracted from failing human hearts demonstrated a close relation of uPA with apoptosis and the p53 pathway. Furthermore, we observed a close correlation of uPA and p53 protein in homogenized tissue lysates. In vitro studies revealed that uPA preincubation protected HACM from oxidative damage induced cell death and reduced oxidative damage foci. uPA protection is independent of its catalytic activity, as the amino terminal fragment of uPA showed similar protection. A key enzyme for repairing oxidative DNA damage is the p53 target hOGG1. We found a significant increase of hOGG1 after pretreatment of HACM with uPA. Knockdown of hOGG1 completely abrogated the protective effect of uPA. We conclude that uPA might have a tissue protective role in human hearts besides its role in tissue remodeling. Tissue protection is mediated by the DNA repair protein hOGG1. This might be beneficial during tissue remodeling and thus could be a target for therapeutic approaches in the diseased heart.

Gene therapy with the TRF1 telomere gene rescues decreased TRF1 levels with aging and prolongs mouse health span

The shelterin complex protects telomeres by preventing them from being degraded and recognized as double‐strand DNA breaks. TRF1 is an essential component of shelterin, with important roles in telomere protection and telomere replication. We previously showed that TRF1 deficiency in the context of different mouse tissues leads to loss of tissue homeostasis owing to impaired stem cell function. Here, we show that TRF1 levels decrease during organismal aging both in mice and in humans. We further show that increasing TRF1 expression in both adult (1‐year‐old) and old (2‐year‐old) mice using gene therapy can delay age‐associated pathologies. To this end, we used the nonintegrative adeno‐associated serotype 9 vector (AAV9), which transduces the majority of mouse tissues allowing for moderate and transient TRF1 overexpression. AAV9‐TRF1 gene therapy significantly prevented age‐related decline in neuromuscular function, glucose tolerance, cognitive function, maintenance of subcutaneous fat, and chronic anemia. Interestingly, although AAV9‐TRF1 treatment did not significantly affect median telomere length, we found a lower abundance of short telomeres and of telomere‐associated DNA damage in some tissues. Together, these findings suggest that rescuing naturally decreased TRF1 levels during mouse aging using AAV9‐TRF1 gene therapy results in an improved mouse health span.

Impact of biological aging on arterial aging in American Indians: findings from the Strong Heart Family Study

Telomere length, a marker of biological aging, has been associated with cardiovascular disease (CVD). Increased arterial stiffness, an indicator of arterial aging, predicts adverse CVD outcomes. However, the relationship between telomere length and arterial stiffness is less well studied. Here we examined the cross-sectional association between leukocyte telomere length (LTL) and arterial stiffness in 2,165 American Indians in the Strong Heart Family Study (SHFS). LTL was measured by qPCR. Arterial stiffness was assessed by stiffness index β. The association between LTL and arterial stiffness was assessed by generalized estimating equation model, adjusting for sociodemographics (age, sex, education level), study site, metabolic factors (fasting glucose, lipids, systolic blood pressure, and kidney function), lifestyle (BMI, smoking, drinking, and physical activity), and prevalent CVD. Results showed that longer LTL was significantly associated with a decreased arterial stiffness (β=-0.070, P=0.007). This association did not attenuate after further adjustment for hsCRP (β=-0.071, P=0.005) or excluding participants with overt CVD (β=-0.068, P=0.012), diabetes (β=-0.070, P=0.005), or chronic kidney disease (β=-0.090, P=0.001). In summary, shorter LTL was significantly associated with an increased arterial stiffness, independent of known risk factors. This finding may shed light on the potential role of biological aging in arterial aging in American Indians.

Age-related Impairment of Vascular Structure and Functions

Among age-related diseases, cardiovascular and cerebrovascular diseases are major causes of death. Vascular dysfunction is a key characteristic of these diseases wherein age is an independent and essential risk factor. The present work will review morphological alterations of aging vessels in-depth, which includes the discussion of age-related microvessel loss and changes to vasculature involving the capillary basement membrane, intima, media, and adventitia as well as the accompanying vascular dysfunctions arising from these alterations.

Selected life-extending interventions reduce arterial CXCL10 and macrophage colony-stimulating factor in aged mouse arteries

Cardiovascular disease (CVD) is the leading cause of death in the industrialized world. Aging is the most predictive risk factor for CVD and is associated with arterial inflammation which contributes to increased CVD risk. Although age-related arterial inflammation has been described in both humans and animals, only a limited number of inflammatory mediators, cytokines and chemokines have been identified. In this investigation we sought to determine whether lifespan extending interventions, including crowded litter early life nutrient deprivation (CL), traditional lifelong caloric restriction (CR) and lifelong Rapamycin treatment (Rap) would attenuate age-related arterial inflammation using multi analyte profiling. Aortas from Young (4-6months), Old (22months), Old CL, Old CR and Old Rap mice were homogenized and cytokine concentrations were assessed using Luminex Multi Analyte Profiling. Chemokines involved in immune cell recruitment, such as CCL2, CXCL9, CXCL10, GMCSF and MCSF, were increased in Old vs. Young (p<0.05). The age-related increase of CXCL10 was prevented by CR (p<0.05 vs. Old). MSCF concentrations were lower in aortas of Rap treated mice (p<0.05 vs. Old). Interleukins (IL), IL-1α, IL-1β and IL-10, were also greater in Old vs. Young mice (p<0.05). These data demonstrate selected lifespan extending interventions can prevent or limit age-related increases in selected aortic chemokines.

DNA damage-dependent mechanisms of ageing and disease in the macro- and microvasculature

A decline in the function of the macro- and micro-vasculature occurs with ageing. DNA damage also accumulates with ageing, and thus DNA damage and repair have important roles in physiological ageing. Considerable evidence also supports a crucial role for DNA damage in the development and progression of macrovascular disease such as atherosclerosis. These findings support the concept that prolonged exposure to risk factors is a major stimulus for DNA damage within the vasculature, in part via the generation of reactive oxygen species. Genomic instability can directly affect vascular cellular function, leading to cell cycle arrest, apoptosis and premature vascular cell senescence. In contrast, the study of age-related impaired function and DNA damage mechanisms in the microvasculature is limited, although ageing is associated with microvessel endothelial dysfunction. This review examines current knowledge on the role of DNA damage and DNA repair systems in macrovascular disease such as atherosclerosis and microvascular disease. We also discuss the cellular responses to DNA damage to identify possible strategies for prevention and treatment.

Reduced Ang2 expression in aging endothelial cells

Aging endothelial cells are characterized by increased cell size, reduced telomere length and increased expression of proinflammatory cytokines. In addition, we describe here that aging reduces the migratory distance of endothelial cells. Furthermore, we observe an increase of the quiescence protein Ang1 and a decrease of the endothelial activation protein Ang2 upon aging. Supplementing Ang2 to aged endothelial cells restored their migratory capacity. We conclude that aging shifts the balance of the Ang1/Ang2 network favouring a quiescent state. Activation of endothelial cells in aging might be necessary to enhance wound healing capacities.

Proton Pump Inhibitors Accelerate Endothelial Senescence

RATIONALE

Proton pump inhibitors (PPIs) are popular drugs for gastroesophageal reflux, which are now available for long-term use without medical supervision. Recent reports suggest that PPI use is associated with cardiovascular, renal, and neurological morbidity.

OBJECTIVE

To study the long-term effect of PPIs on endothelial dysfunction and senescence and investigate the mechanism involved in PPI-induced vascular dysfunction.

METHODS AND RESULTS

Chronic exposure to PPIs impaired endothelial function and accelerated human endothelial senescence by reducing telomere length.

CONCLUSIONS

Our data may provide a unifying mechanism for the association of PPI use with increased risk of cardiovascular, renal, and neurological morbidity and mortality.