Exercise training attenuates cardiac inflammation and fibrosis in hypertensive ovariectomized rats

Changes in cardiovascular arachidonic acid metabolism in experimental models of menopause and implications on postmenopausal cardiac hypertrophy

Menopause is a normal stage in the human female aging process characterized by the cessation of menstruation and the ovarian production of estrogen and progesterone hormones. Menopause is associated with an increased risk of several different diseases. Cardiovascular diseases are generally less common in females than in age-matched males. However, this female advantage is lost after menopause. Cardiac hypertrophy is a disease characterized by increased cardiac size that develops as a response to chronic overload or stress. Similar to other cardiovascular diseases, the risk of cardiac hypertrophy significantly increases after menopause. However, the exact underlying mechanisms are not yet fully elucidated. Several studies have shown that surgical or chemical induction of menopause in experimental animals is associated with cardiac hypertrophy, or aggravates cardiac hypertrophy induced by other stressors. Arachidonic acid (AA) released from the myocardial phospholipids is metabolized by cardiac cytochrome P450 (CYP), cyclooxygenase (COX), and lipoxygenase (LOX) enzymes to produce several eicosanoids. AA-metabolizing enzymes and their respective metabolites play an important role in the pathogenesis of cardiac hypertrophy. Menopause is associated with changes in the cardiovascular levels of CYP, COX, and LOX enzymes and the levels of their metabolites. It is possible that these changes might play a role in the increased risk of cardiac hypertrophy after menopause.

Alterations in cardiac contractile and regulatory proteins contribute to age-related cardiac dysfunction in male rats

Aging is associated with cardiac contractile abnormalities, but the etiology of these contractile deficits is unclear. We hypothesized that cardiac contractile and regulatory protein expression is altered during aging. To investigate this possibility, left ventricular (LV) lysates were prepared from young (6 months) and old (24 months) Fischer344 rats. There are no age-related changes in SERCA2 expression or phospholamban phosphorylation. Additionally, neither titin isoform expression nor phosphorylation differed. However, there is a significant increase in β-isoform of the myosin heavy chain (MyHC) expression and phosphorylation of TnI and MyBP-C during aging. In permeabilized strips of papillary muscle, force and Ca2+ sensitivity are reduced during aging, consistent with the increase in β-MyHC expression and TnI phosphorylation. However, the increase in MyBP-C phosphorylation during aging may represent a mechanism to compensate for age-related contractile deficits. In isolated cardiomyocytes loaded with Fura-2, the peak of the Ca2+ transient is reduced, but the kinetics of the Ca2+ transient are not altered. Furthermore, the extent of shortening and the rates of both sarcomere shortening and re-lengthening are reduced. These results demonstrate that aging is associated with changes in contractile and regulatory protein expression and phosphorylation, which affect the mechanical properties of cardiac muscle.

Aging related decreases in NM myosin expression and contractility in a resistance vessel

Introduction: Vasodilatation in response to NO is a fundamental response of the vasculature, and during aging, the vasculature is characterized by an increase in stiffness and decrease in sensitivity to NO mediated vasodilatation. Vascular tone is regulated by the activation of smooth muscle and nonmuscle (NM) myosin, which are regulated by the activities of myosin light chain kinase (MLCK) and MLC phosphatase. MLC phosphatase is a trimeric enzyme with a catalytic subunit, myosin targeting subunit (MYPT1) and 20 kDa subunit of unknown function. Alternative mRNA splicing produces LZ+/LZ- MYPT1 isoforms and the relative expression of LZ+/LZ- MYPT1 determines the sensitivity to NO mediated vasodilatation. This study tested the hypothesis that aging is associated with changes in LZ+ MYPT1 and NM myosin expression, which alter vascular reactivity. Methods: We determined MYPT1 and NM myosin expression, force and the sensitivity of both endothelial dependent and endothelial independent relaxation in tertiary mesenteric arteries of young (6mo) and elderly (24mo) Fischer344 rats. Results: The data demonstrate that aging is associated with a decrease in both the expression of NM myosin and force, but LZ+ MYPT expression and the sensitivity to both endothelial dependent and independent vasodilatation did not change. Further, smooth muscle cell hypertrophy increases the thickness of the medial layer of smooth muscle with aging. Discussion: The reduction of NM myosin may represent an aging associated compensatory mechanism to normalize the stiffness of resistance vessels in response to the increase in media thickness observed during aging.

Combined cardiovascular effects of ovariectomy and high-intensity interval training in female spontaneously hypertensive rats

Hypertensive postmenopausal women are more likely to develop adverse cardiac remodeling and respond less effectively to drug treatment than men. High-intensity interval exercise (HIIE) is a nonpharmacological strategy for the treatment of hypertension; however, the effectiveness in women remains uncertain. This study was designed to evaluate 1) the effects of HIIE training upon morphological and functional markers of cardiovascular health in female SHR and 2) to determine whether the hormonal shift induced by ovariectomy could influence cardiovascular responses to HIIE. Thirty-six SHR were randomly assigned to four groups: ovariectomized sedentary, ovariectomized trained, sham-operated sedentary, and sham-operated trained. The trained rats performed HIIE 5 days/wk for 8 wk. Blood pressure and echocardiographic measurements were performed before and after training in animals. Cardiac response to β-adrenergic stimulation and the expression of calcium regulatory proteins and estrogen receptors in heart samples were assessed. Endothelium-dependent vasorelaxation in response to acetylcholine was evaluated in aortic rings as well as the expression of nitric oxide synthase isoforms (eNOS and P-eNOS) by Western blotting. In both groups of trained SHR, HIIE induced eccentric cardiac remodeling with greater inotropic and chronotropic effects, as well as an increase in SERCA and β1AR expression. However, although the trained rats showed improved endothelial function and expression of eNOS and P-eNOS in the aorta, there was no demonstrated effect on blood pressure. In addition, the responses to HIIE training were not affected by ovariectomy. This work highlights the importance of assessing the cardiovascular efficacy and safety of different exercise modalities in women.NEW & NOTEWORTHY This study reports the effects of high-intensity interval exercise (HIIE) training on cardiac and endothelial function in female hypertensive rats. Despite a lack of effect on blood pressure (BP), HIIE training induces eccentric cardiac remodeling with greater functionals effects. Furthermore, training has beneficial effects on endothelial function. However, ovarian hormones do not seem to modulate cardiac and aortic adaptations to this training modality. All this underlines the need to consider training modalities on the cardiovascular system in women.

Intrinsic and Extrinsic Contributors to the Cardiac Benefits of Exercise

Among its many cardiovascular benefits, exercise training improves heart function and protects the heart against age-related decline, pathological stress, and injury. Here, we focus on cardiac benefits with an emphasis on more recent updates to our understanding. While the cardiomyocyte continues to play a central role as both a target and effector of exercise's benefits, there is a growing recognition of the important roles of other, noncardiomyocyte lineages and pathways, including some that lie outside the heart itself. We review what is known about mediators of exercise's benefits-both those intrinsic to the heart (at the level of cardiomyocytes, fibroblasts, or vascular cells) and those that are systemic (including metabolism, inflammation, the microbiome, and aging)-highlighting what is known about the molecular mechanisms responsible.

Exercise improves cardiac function and attenuates myocardial inflammation and apoptosis by regulating APJ/STAT3 in mice with stroke

Stroke can induce cardiac dysfunction without a primary cardiac disease. Exercise can promote the overall rehabilitation of stroke patients and be beneficial for all kinds of heart diseases. However, the mechanisms underlying the protective effects of exercise in stroke-induced cardiac dysfunction are poorly understood. Hence, we aimed to distinguish the different effects of acute and long-term exercise and further study the mechanism of protection against cardiomyopathy caused by stroke. Mice underwent a single acute session or long-term exercise for 30 days, followed by middle cerebral artery occlusion surgery. The expression of apoptosis-related proteins and proinflammatory factors in the heart was evaluated. Then, overexpression of apelin peptide jejunum (APJ) transfected adeno-associated virus type 9 (AAV9) and inhibition of signal transducer and activator of transcription 3 (STAT3) by Stattic were used in stroke mice or hypoxic cardiomyocytes. ML221 were used to inhibit APJ activity in exercise mouse. Thereafter, changes in apoptotic and proinflammatory factors were evaluated. The results demonstrated that chronic exercise prevented myocardial inflammation, apoptosis and cardiac dysfunction after stroke. However, acute exercise did not have similar effects. Exercise maintained the levels of APJ expression and decreased phosphorylated-STAT3 (p-STAT3) activation to protect cardiomyocytes. Moreover, APJ overexpression promoted cardiomyocyte survival and reduced p-STAT3 levels. STAT3 inhibition also reduced apoptosis and proinflammatory factors in mice hearts. Conversely, the protective effect of exercise was eliminated by APJ inhibition. This study showed that exercise can maintain APJ expression and inhibit p-STAT3, thus, conferring protection against myocardial inflammation and apoptosis induced by stroke.

Tracking Biomarker Responses to Exercise in Hypertension

PURPOSE OF REVIEW

Strong evidence is evolving that physical exercise prevents hypertension and reduces blood pressure in patients with pre- and manifest HTN. Yet, identifying and confirming the effectiveness of exercise are challenging. Herein, we discuss conventional and novel biomarkers such as extracellular vesicles (EVs) which may track responses to HTN before and after exercise.

RECENT FINDINGS

Evolving data shows that improved aerobic fitness and vascular function as well as lowered oxidative stress, inflammation, and gluco-lipid toxicity are leading biomarkers considered to promote HTN, but they explain only about a half of the pathophysiology. Novel biomarkers such as EVs or microRNA are providing additional input to understand the complex mechanisms involved in exercise therapy for HTN patients. Conventional and novel biomarkers are needed to fully understand the integrative "cross-talk" between tissues to regulate vasculature physiology for blood pressure control. These biomarker studies will lead to more specific disease markers and the development of even more personalized therapy in this field. However, more systematic approaches and randomized controlled trials in larger cohorts are needed to assess exercise effectiveness across the day and with different exercise types.

Exercise Training Attenuates Acute β-Adrenergic Receptor Activation-Induced Cardiac Inflammation via the Activation of AMP-Activated Protein Kinase

Exercise has proven cardiac benefits, but the underlying mechanisms of exercise that protect the heart from acute sympathetic stress injuries remain unknown. In this study, adult C57BL/6J mice and their AMP-activated protein kinase α2 knockout (AMPKα2^-/-) littermates were either subjected to 6 weeks of exercise training or housed under sedentary conditions and then treated with or without a single subcutaneous injection of the β-adrenergic receptor (β-AR) agonist isoprenaline (ISO). We investigated the differences in the protective effects of exercise training on ISO-induced cardiac inflammation in wild-type (WT) and AMPKα2^-/- mice using histology, enzyme-linked immunosorbent assay (ELISA) and Western blotting analyses. The results indicated that exercise training alleviated ISO-induced cardiac macrophage infiltration, chemokines and the expression of proinflammatory cytokines in wild-type mice. A mechanism study showed that exercise training attenuated the ISO-induced production of reactive oxygen species (ROS) and the activation of NLR Family, pyrin domain-containing 3 (NLRP3) inflammasomes. In cardiomyocytes, the ISO-induced effects on these processes were inhibited by AMP-activated protein kinase (AMPK) activator (metformin) pretreatment and reversed by the AMPK inhibitor (compound C). AMPKα2^-/- mice showed more extensive cardiac inflammation following ISO exposure than their wild-type littermates. These results indicated that exercise training could attenuate ISO-induced cardiac inflammation by inhibiting the ROS-NLRP3 inflammasome pathway in an AMPK-dependent manner. Our findings suggested the identification of a novel mechanism for the cardioprotective effects of exercise.

Beyond cardiomyocytes: Cellular diversity in the heart's response to exercise

Cardiomyocytes comprise ∼70% to 85% of the total volume of the adult mammalian heart but only about 25% to 35% of its total number of cells. Advances in single cell and single nuclei RNA sequencing have greatly facilitated investigation into and increased appreciation of the potential functions of non-cardiomyocytes in the heart. While much of this work has focused on the relationship between non-cardiomyocytes, disease, and the heart's response to pathological stress, it will also be important to understand the roles that these cells play in the healthy heart, cardiac homeostasis, and the response to physiological stress such as exercise. The present review summarizes recent research highlighting dynamic changes in non-cardiomyocytes in response to the physiological stress of exercise. Of particular interest are changes in fibrotic pathways, the cardiac vasculature, and immune or inflammatory cells. In many instances, limited data are available about how specific lineages change in response to exercise or whether the changes observed are functionally important, underscoring the need for further research.

Heart Failure in Menopause: Treatment and New Approaches

Aging is an important risk factor for the development of heart failure (HF) and half of patients with HF have preserved ejection fraction (HFpEF) which is more common in elderly women. In general, sex differences that lead to discrepancies in risk factors and to the development of cardiovascular disease (CVD) have been attributed to the reduced level of circulating estrogen during menopause. Estrogen receptors adaptively modulate fibrotic, apoptotic, inflammatory processes and calcium homeostasis, factors that are directly involved in the HFpEF. Therefore, during menopause, estrogen depletion reduces the cardioprotection. Preclinical menopause models demonstrated that several signaling pathways and organ systems are closely involved in the development of HFpEF, including dysregulation of the renin-angiotensin system (RAS), chronic inflammatory process and alteration in the sympathetic nervous system. Thus, this review explores thealterations observed in the condition of HFpEF induced by menopause and the therapeutic targets with potential to interfere with the disease progress.

Dipeptide IF and Exercise Training Attenuate Hypertension in SHR Rats by Inhibiting Fibrosis and Hypertrophy and Activating AMPKα1, SIRT1, and PGC1α

Bioactive peptides are physiologically active peptides produced from proteins by gastrointestinal digestion, fermentation, or hydrolysis by proteolytic enzymes. Bioactive peptides are resorbed in their whole form and have a preventive effect against various disease conditions, including hypertension, dyslipidemia, inflammation, and oxidative stress. In recent years, there has been a growing body of evidence showing that physiologically active peptides may have a function in sports nutrition. The present study aimed to evaluate the synergistic effect of dipeptide (IF) from alcalase potato protein hydrolysates and exercise training in hypertensive (SHR) rats. Animals were divided into five groups. Bioactive peptide IF and swimming exercise training normalized the blood pressure and decreased the heart weight. Cardiac, hepatic, and renal functional markers also normalized in SHR rats. The combined administration of IF peptide and exercise offer better protection in SHR rats by downregulating proteins associated with myocardial fibrosis, hypertrophy, and inflammation. Remarkably, peptide treatment alongside exercise activates the PI3K/AKT cell survival pathway in the myocardial tissue of SHR animals. Further, the mitochondrial biogenesis pathway (AMPKα1, SIRT1, and PGC1α) was synergistically activated by the combinatorial treatment of IF and exercise. Exercise training along with IF administration could be a possible approach to alleviating hypertension.

Animal Models of Exercise From Rodents to Pythons

Acute and chronic animal models of exercise are commonly used in research. Acute exercise testing is used, often in combination with genetic, pharmacological, or other manipulations, to study the impact of these manipulations on the cardiovascular response to exercise and to detect impairments or improvements in cardiovascular function that may not be evident at rest. Chronic exercise conditioning models are used to study the cardiac phenotypic response to regular exercise training and as a platform for discovery of novel pathways mediating cardiovascular benefits conferred by exercise conditioning that could be exploited therapeutically. The cardiovascular benefits of exercise are well established, and, frequently, molecular manipulations that mimic the pathway changes induced by exercise recapitulate at least some of its benefits. This review discusses approaches for assessing cardiovascular function during an acute exercise challenge in rodents, as well as practical and conceptual considerations in the use of common rodent exercise conditioning models. The case for studying feeding in the Burmese python as a model for exercise-like physiological adaptation is also explored.

Anti-apoptotic effects of diosgenin on ovariectomized hearts

BACKGROUND

The anti-apoptotic effects of diosgenin, a steroid saponin, on hearts in female with estrogen deficiency have been less studied. This study aimed to evaluate the anti-apoptotic effects of diosgenin on cardiac widely dispersed apoptosis in a bilateral ovariectomized animal model.

METHODS

A total of 60 female Wistar rats, aged 6-7 months, were divided into the sham-operated group (Sham), bilateral ovariectomized rats for 2 months, and ovariectomized rats administered with 0, 10, 50, or 100 mg/kg diosgenin daily (OVX, OVX 10, OVX 50, and OVX 100, respectively) in the second month. The excised hearts were analyzed by H&E staining, TUNEL(+) assays and Western Blot.

RESULT

Cardiac TUNEL(+) apoptotic cells, the levels of Fas ligand, Fas death receptors, Fas-associated death domain, active caspase-8, and active caspase-3 (FasL/Fas-mediated pathways) as well as the levels of Bax, Bad, Bax/Bcl2, Bad/p-Bad, cytosolic Cytochrome c, active caspase-9, and active caspase-3 (mitochondria-initiated pathway) were increased in OVX compared with Sham group but those were decreased in OVX 50 compared with OVX.

CONCLUSION

Diosgenin appeared to prevent or suppress ovariectomy-induced cardiac FasL/Fas-mediated and mitochondria-initiated apoptosis. These findings might provide one of the possible therapeutic approaches of diosgenin for potentially preventing cardiac apoptosis in women after bilateral ovariectomy or women with estrogen deficiency.

Antihypertensive effects of exercise involve reshaping of gut microbiota and improvement of gut-brain axis in spontaneously hypertensive rat

Exercise (Ex) has long been recognized to produce beneficial effects on hypertension (HTN). This coupled with evidence of gut dysbiosis and an impaired gut-brain axis led us to hypothesize that reshaping of gut microbiota and improvement in impaired gut-brain axis would, in part, be associated with beneficial influence of exercise. Male spontaneously hypertensive rats (SHR) and Wistar Kyoto (WKY) rats were randomized into sedentary, trained, and detrained groups. Trained rats underwent moderate-intensity exercise for 12 weeks, whereas, detrained groups underwent 8 weeks of moderate-intensity exercise followed by 4 weeks of detraining. Fecal microbiota, gut pathology, intestinal inflammation, and permeability, brain microglia and neuroinflammation were analyzed. We observed that exercise training resulted in a persistent decrease in systolic blood pressure in the SHR. This was associated with increase in microbial α diversity, altered β diversity, and enrichment of beneficial bacterial genera. Furthermore, decrease in the number of activated microglia, neuroinflammation in the hypothalamic paraventricular nucleus, improved gut pathology, inflammation, and permeability were also observed in the SHR following exercise. Interestingly, short-term detraining did not abolish these exercise-mediated improvements. Finally, fecal microbiota transplantation from exercised SHR into sedentary SHR resulted in attenuated SBP and an improved gut-brain axis. These observations support our concept that an impaired gut-brain axis is linked to HTN and exercise ameliorates this impairment to induce antihypertensive effects.

Exercise as a multi-modal disease-modifying medicine in systemic sclerosis: An introduction by The Global Fellowship on Rehabilitation and Exercise in Systemic Sclerosis (G-FoRSS)

Systemic sclerosis (SSc) is a heterogeneous multisystem autoimmune disease whereby its main pathological drivers of disability and damage are vascular injury, inflammatory cell infiltration, and fibrosis. These mechanisms result in diffuse and diverse impairments arising from ischemic circulatory dysfunction leading to painful skin ulceration and calcinosis, neurovascular aberrations hindering gastrointestinal (GI) motility, progressive painful, incapacitating or immobilizing effects of inflammatory and fibrotic effects on the lungs, skin, articular and periarticular structures, and muscle. SSc-related impairments impede routine activities of daily living (ADLs) and disrupt three critical life areas: work, family, social/leisure, and also impact on psychological well-being. Physical activity and exercise are globally recommended; however, for connective tissue diseases, this guidance carries greater impact on inflammatory disease manifestations, recovery, and cardiovascular health. Exercise, through myogenic and vascular phenomena, naturally targets key pathogenic drivers by downregulating multiple inflammatory and fibrotic pathways in serum and tissue, while increasing circulation and vascular repair. G-FoRSS, The Global Fellowship on Rehabilitation and Exercise in Systemic Sclerosis recognizes the scientific basis of and advocates for education and research of exercise as a systemic and targeted SSc disease-modifying treatment. An overview of biophysiological mechanisms of physical activity and exercise are herein imparted for patients, clinicians, and researchers, and applied to SSc disease mechanisms, manifestations, and impairment. A preliminary guidance on exercise in SSc, a research agenda, and the current state of research and outcome measures are set forth.

Unveiling the role of exercise training in targeting the inflammatory paradigm of heart failure with preserved ejection fraction: a narrative review

Heart failure with preserved ejection fraction (HFpEF) is currently lacking an effective pharmacological treatment with impact on major outcomes such as hospitalization and mortality. Exercise training (EXT) is recognized as an important nonpharmacological tool, capable of improving exercise capacity and quality of life, and has even been associated with a reduction in hospitalization and cardiovascular mortality risk. However, this positive impact largely lacks a physiological explanation. The aim of this narrative review was to provide an overview of the available data supporting the hypothesis that the beneficial role of EXT in HFpEF might be due to its effects on targeting the inflammatory paradigm described for this disease. A comprehensive literature search was conducted using the PubMed-NCBI database. We reviewed the effects of EXT throughout each step of the pathophysiological pathway leading to HFpEF and found clinical and/or preclinical evidence supporting the reduction of systemic inflammation, endothelial dysfunction, microvascular rarefaction, and myocardial stiffness. We also highlighted some gaps in the knowledge or topics that deserve further clarification in future studies. In conclusion, despite the scarcity of clinical studies in this population, there is compelling evidence suggesting that EXT modulates crucial aspects of the inflammatory pathway described for HFpEF and future investigation on cellular and molecular mechanisms are encouraged.

Health-Related Quality of Life (HRQoL) in Sarcoidosis: Diagnosis, Management, and Health Outcomes

Health-related quality of life (HRQoL), though rarely considered as a primary endpoint in clinical trials, may be the single outcome reflective of patient priorities when living with a health condition. HRQoL is a multi-dimensional concept that reflects the degree to which a health condition interferes with participation in and fulfillment of important life areas. HRQoL is intended to capture the composite degree of physical, physiologic, psychological, and social impairment resulting from symptom burden, patient-perceived disease severity, and treatment side effects. Diminished HRQoL expectedly correlates to worsening disability and death; but interventions addressing HRQoL are linked to increased survival. Sarcoidosis, being a multi-organ system disease, is associated with a diffuse array of manifestations resulting in multiple symptoms, complications, and medication-related side effects that are linked to reduced HRQoL. Diminished HRQoL in sarcoidosis is related to decreased physical function, pain, significant loss of income, absence from work, and strain on personal relationships. Symptom distress can result clearly from a sarcoidosis manifestation (e.g., ocular pain, breathlessness, cough) but may also be non-specific, such as pain or fatigue. More complex, a single non-specific symptom, e.g., fatigue may be directly sarcoidosis-derived (e.g., inflammatory state, neurologic, hormonal, cardiopulmonary), medication-related (e.g., anemia, sleeplessness, weight gain, sub-clinical infection), or an indirect complication (e.g., sleep apnea, physical deconditioning, depression). Identifying and distinguishing underlying causes of impaired HRQoL provides opportunity for treatment strategies that can greatly impact a patient's function, well-being, and disease outcomes. Herein, we present a reference manual that describes the current state of knowledge in sarcoidosis-related HRQoL and distinguish between diverse causes of symptom distress and other influences on sarcoidosis-related HRQoL. We provide tools to assess, investigate, and diagnose compromised HRQoL and its influencers. Strategies to address modifiable HRQoL factors through palliation of symptoms and methods to improve the sarcoidosis health profile are outlined; as well as a proposed research agenda in sarcoidosis-related HRQoL.

Cardiovascular disease risk factors induce mesenchymal features and senescence in mouse cardiac endothelial cells

Aging, obesity, hypertension, and physical inactivity are major risk factors for endothelial dysfunction and cardiovascular disease (CVD). We applied fluorescence-activated cell sorting (FACS), RNA sequencing, and bioinformatic methods to investigate the common effects of CVD risk factors in mouse cardiac endothelial cells (ECs). Aging, obesity, and pressure overload all upregulated pathways related to TGF-β signaling and mesenchymal gene expression, inflammation, vascular permeability, oxidative stress, collagen synthesis, and cellular senescence, whereas exercise training attenuated most of the same pathways. We identified collagen chaperone Serpinh1 (also called as Hsp47) to be significantly increased by aging and obesity and repressed by exercise training. Mechanistic studies demonstrated that increased SERPINH1 in human ECs induced mesenchymal properties, while its silencing inhibited collagen deposition. Our data demonstrate that CVD risk factors significantly remodel the transcriptomic landscape of cardiac ECs inducing inflammatory, senescence, and mesenchymal features. SERPINH1 was identified as a potential therapeutic target in ECs.

Cardiovascular diseases are the number one cause of death in the western world. Endothelial cells that line the blood vessels of the heart play a central role in the development of these diseases. In addition to helping transport blood, these cells support the normal running of the heart, and help it to grow and regenerate. Over time as the body ages and experiences stress, endothelial cells start to deteriorate. This can cause the cells to undergo senescence and stop dividing, and lay down scar-like tissue via a process called fibrosis. As a result, the blood vessels start to stiffen and become less susceptible to repair.

Ageing, obesity, high blood pressure, and inactivity all increase the risk of developing cardiovascular diseases, whereas regular exercise has a protective effect. But it was unclear how these different factors affect endothelial cells. To investigate this, Hemanthakumar et al. compared the gene activity of different sets of mice: old vs young, obese vs lean, heart problems vs healthy, and fit vs sedentary.

All these risk factors – age, weight, inactivity and heart defects – caused the mice’s endothelial cells to activate mechanisms that lead to stress, senescence and fibrosis. Whereas exercise training had the opposite effect, and turned off the same genes and pathways. All of the at-risk groups also had high levels of a gene called SerpinH1, which helps produce tissue fiber and collagen. Experiments increasing the levels of SerpinH1 in human endothelial cells grown in the laboratory recreated the effects seen in mice, and switched on markers of stress, senescence and fibrosis.

According to the World Health Organization, cardiovascular disease now accounts for 10% of the disease burden worldwide. Revealing the affects it has on gene activity could help identify new targets for drug development, such as SerpinH1. Understanding the molecular effects of exercise on blood vessels could also aid in the design of treatments that mimic exercise. This could help people who are unable to follow training programs to reduce their risk of cardiovascular disease.