For patients with ischaemic heart disease, remote ischaemic conditioning may offer an innovative, non‐invasive and virtually cost‐free therapy for protecting the myocardium against the detrimental effects of acute ischaemia‐reperfusion injury, preserving cardiac function and improving clinical outcomes. The intriguing phenomenon of remote ischaemic conditioning was first discovered over 20 years ago, when it was shown that the heart could be rendered resistant to acute ischaemia‐reperfusion injury by applying one or more cycles of brief ischaemia and reperfusion to an organ or tissue away from the heart – initially termed ‘cardioprotection at a distance’. Subsequent pre‐clinical and then clinical studies made the important discovery that remote ischaemic conditioning could be elicited non‐invasively, by inducing brief ischaemia and reperfusion to the upper or lower limb using a cuff. The actual mechanism underlying remote ischaemic conditioning cardioprotection remains unclear, although a neuro‐hormonal pathway has been implicated. Since its initial discovery in 1993, the first proof‐of‐concept clinical studies of remote ischaemic conditioning followed in 2006, and now multicentre clinical outcome studies are underway. In this review article, we explore the potential mechanisms underlying this academic curiosity, and assess the success of its application in the clinical setting. Cardiovascular disease remains the leading cause of death and disability worldwide, accounting for 17 million deaths in 2008, of which ischaemic heart disease (IHD) is a major contributor In this review article, we discuss the non‐invasive, virtually cost‐free strategy of remote ischaemic conditioning (RIC), which has made the leap from being an academic curiosity to a potential clinical therapy.We undertook a PubMed search using the keywords myocardial infarction, reperfusion, ischaemia, remote, preconditioning, postconditioning, perconditioning, cardiac and vascular surgery, CABG, coronary intervention, and cardiopulmonary bypass and reviewed papers retrieved using these search terms. In addition, references to papers were examined, and papers of relevance were also reviewed. Certain landmark papers have been referred to, independent of the PubMed search criteria.The endogenous cardioprotective phenomena of ischaemic preconditioning, first discovered in 1986 The first experimental study to describe this cardioprotective phenomenon was published by Przyklenk et al. in 1993 preconditioning), with subsequent experimental studies reporting efficacy with the conditioning stimulus applied at varying time points. These include 12–24 h before the index myocardial ischaemic episode (delayed remote ischaemic preconditioning); after the onset of myocardial ischaemia, but before reperfusion (remote ischaemic perconditioning); at the onset of myocardial reperfusion (remote ischaemic postconditioning); and most recently, even after 15 min of myocardial reperfusion has elapsed (delayed remote ischaemic postconditioning).One other major advantage of RIC is its ability to confer cardioprotection when applied at a number of different time points in relation to the index myocardial ischaemia‐reperfusion episode, a feature that has also facilitated its clinical application. The early experimental studies focused on applying the conditioning stimulus immediately before the index myocardial ischaemic episode  generation of the cardioprotective signal in the conditioned remote organ or tissue; (ii) the pathway that conveys the cardioprotective signal from the conditioned remote organ or tissue to the heart; and (iii) the activation of intracellular signalling pathways within the heart that mediate the cardioprotective effect Fig. . The curA number of experimental studies have implicated a blood‐borne factor(s) generated in the RIC‐treated animal as potential mediators of cardioprotection. The evidence for this is derived from the following studies. Gho et al. noted that RIC would only protect the heart if the conditioned intestine was reperfused, suggesting that reperfusion was required to wash the cardioprotective factor out of the conditioned tissue Current evidence suggests the factor is between 3.5 and 30 kDa, thermolabile and hydrophobic. Using dialysis membranes to fractionate the proteins within coronary effluent or serum according to their molecular weight, several studies demonstrated the factor to be smaller than 30 kDa Several experimental studies have suggested that the cardioprotective effect elicited by a RIC stimulus delivered in vivo was still present, even when the heart was isolated and subjected to acute MI either on a Langendorff apparatus (isolated perfused hearts) Although the identity of the blood‐borne cardioprotective mediator of RIC remains unknown, a number of candidate molecules have been suggested including opioid A number of experimental studies have suggested the involvement of a neural pathway in RIC cardioprotection. The evidence for this is summarised below. Gho et al. first noted that the ganglion blocker, hexamethonium, blocked RIC‐induced cardioprotection elicited by intestinal conditioning, thereby implicating a role for the autonomic ganglia of the sympathetic and parasympathetic nervous systems in inter‐organ protection Given the involvement of the autonomic nervous system in RIC, it is logical to hypothesise that the RIC cardioprotection is dependent on an intact sensory afferent neuronal pathway at the remote organ or tissue. Indeed, transection of the femoral nerve before application of the RIC stimulus abolishes cardioprotection The question arose, therefore, of how the brief ischaemic burden to the tissue or organ is translated to sensory afferent activation. Experimental studies have demonstrated that the application of brief ischaemia–reperfusion to a remote organ or tissue generates factors such as adenosine The final element concerns the efferent limb of the neural pathway to the heart. Initial studies demonstrated that vagal nerve stimulation Initial experimental studies had implicated a blood‐borne cardioprotective pathway, and an intact neural pathway to the conditioned organ or tissue. Recent studies have investigated the interaction between these two signalling components.It has been reported that RIC by limb ischaemia or intra‐arterial adenosine releases a dialysable blood‐borne cardioprotective factor(s), the release of which required intact sensory innervation of the limb and was blocked by pre‐treatment with the nitric oxide (NO) donor, S‐nitroso‐N‐acetylpenicillamine An important experimental study by Redington et al. demonstrated that either direct femoral nerve stimulation or topical application of capsaicin generated a dialysate that was able to reduce MI size in a naïve isolated rabbit heart, providing the first evidence that the neural pathway to the conditioned limb was required to generate the blood‐borne cardioprotective factor In an interesting clinical study, Jensen et al. found that plasma dialysate obtained from RIC‐treated diabetic patients with sensory neuropathy failed to limit MI size in an isolated naïve rabbit heart, although plasma dialysate harvested from RIC‐treated non‐diabetic and diabetic patients without sensory neuropathy was cardioprotective The concept of remote preconditioning of trauma originally arose from the observation that patients who had undergone abdominal aortic aneurysm (AAA) surgery had a greater risk for MI, a greater infarct size and increased mortality compared with those who had not undergone surgery. Indeed, Ren et al. observed that infarct size in mice increased with prior remote vascular surgery There is some evidence, although inconsistent, that a systemic inflammatory response is obtained in the setting of reperfusion injury. Reperfusion injury per se is associated with a neutrophilic infiltration within the target organ The first major step to the clinical translation of RIC was the discovery that the RIC stimulus could be delivered non‐invasively, by simply applying cycles of inflation–deflation using a standard blood pressure cuff placed on the upper arm CABG surgery, in which the heart is subjected to global ischaemic injury as the heart goes onto cardiopulmonary bypass (CPB), followed by global reperfusion injury as the heart comes off CPB. The global acute IRI that results can be detected as peri‐operative myocardial injury by measuring a rise in serum cardiac enzymes such as creatinine kinase (CK‐MB) and troponin T and I. It can also be detected as areas of late gadolinium enhancement  on cardiac magnetic resonance imaging;Major non‐cardiac vascular surgery, in which peri‐operative myocardial injury measured by a rise in serum cardiac enzymes such as CK‐MB and troponin T and I occurs in 20–30% of patients;Elective PCI. One component of the peri‐procedural myocardial injury that occurs during PCI is due to regional ischaemic injury and coronary microembolisation, the extent of which can be measured by the rise in serum cardiac enzymes;ST‐segment elevation MI (STEMI) treated by primary PCI. Patients presenting with an acute STEMI will usually have a major thrombotic occlusion in one of the major epicardial coronary arteries, resulting in acute myocardial ischaemia, the treatment for which is timely reperfusion using primary PCI. The price for restoring blood flow in the infarct‐related artery, however, is further myocardial injury and cardiomyocyte death – termed myocardial reperfusion injury Remote ischaemic conditioning has been investigated in a number of different clinical settings of acute myocardial IRI: A protocol of four cycles of 5 min ischaemia‐reperfusion of the forearm was applied to children before congenital heart surgery The biggest limitations of the clinical trials in the cardiac surgical setting lie in their study design. The vast majority of them have been single‐centre trials examining small groups of patients admitted for elective CABG surgery. This represents fewer than 50% of patients undergoing major cardiac surgery in England and Wales Two large multicentre, double‐blinded randomised controlled trials aim to address these limitations. The ERICCA  trial, run by our group, is currently recruiting at 30 centres in the UK, and aims to recruit 1610 high‐risk patients undergoing CABG, with or without valve surgery. The primary endpoints in this trial are cardiovascular death, non‐fatal MI, coronary revascularisation and stroke at one year, with various secondary endpoints, including quality of life and exercise tolerance One of the first major trials to give a negative result was conducted by Bonser's group www.clinicaltrials.gov, NCT01864252).First, the translation of RIC into the clinical setting is not straightforward. Remote ischaemic conditioning in the pre‐clinical setting was investigated in young animals that underwent myocardial IRI by direct ligature applied to the coronary artery. There was no pre‐existing disease state, and almost none of the models included any form of cardiopulmonary bypass. Direct translation into the clinical setting of this model is not feasible, as many of our patients have co‐existing morbidity. For instance, unstable angina, which is characterised by intermittent ischaemia, is a form of preconditioning, and patients with unstable angina who then have a MI often do better than patients whose first presentation is an MI Ali et al. were the first to publish on the phenomenon of RIC in the setting of major vascular surgery An early study by Iliodromitis et al. did not show any evidence of benefit from an RIC protocol administered in patients undergoing elective PCI. However, this study may have been underpowered It is important to note that an RIC intervention in the setting of an acute MI would not be a preconditioning stimulus, but a perconditioning or a postconditioning stimulus, as the onset of ischaemia is unpredictable. Primary PCI is the gold standard, and the first study to examine RIC in this setting included 33 patients in each group, but was negative −1.h−1, along the lines of the Bristol model of total intravenous anaesthesia −1.min−1 (7.2 mg.kg−1.h−1) in cardiac surgery resulted in a lower troponin levels at 24 h compared with isoflurane alone or low‐dose propofol (60 μg.kg−1.min−1) While the role of anaesthetic agents has been reviewed elsewhere in this journal −1Given this controversy, it is unclear whether anaesthetic agents enhance or block the effects of RIC. In a clinical trial involving children with congenital heart defects, anaesthesia was induced with sevoflurane and maintained with isoflurane, air and oxygen throughout the procedures. Although the exact dosages were not reported in this study, RIC proved to be cardioprotective Remote ischaemic perconditioning (RIPerC) is a strategy where multiple cycles of ischaemia‐reperfusion are applied during the lethal ischaemia phase, but before reperfusion Remote ischaemic postconditioning (RIPostC) involves the application of the remote ischaemic stimulus at the point of reperfusion. The mechanisms of RIPostC have not been fully elucidated, but there is evidence that it involves the survival activating factor enhancement (SAFE) pathway, rather than the conventional RISK pathway activated in RIPreC. Translation into the clinical arena came in the form of the trial by Hong and co‐workers. They randomly assigned 70 patients having off‐pump CABG to a combination of RIPreC and RIPostC in one group, and controls in the other. This resulted in a 48.7% reduction in peri‐operative injury, as determined by the 72‐h troponin area under the curve At this point, it is worth briefly mentioning the concept of delayed RIPostC. The basis of the concept lies in the supposition that reperfusion injury does not only occur at the point of reperfusion, but can continue for a while after reperfusion. Delayed RIPostC aims to influence protective pathways later in the reperfusion period. At the time of writing, there have been no clinical trials in humans, but pre‐clinical evidence exists that RIPostC may reduce injury in the brain and the heart Remote ischaemic conditioning is a novel strategy that has been shown to reduce myocardial reperfusion injury. While there have been both promising and disappointing results from trials, results from large multicentre randomised controlled trials such as ERICCA and RIPHeart are awaited. Anaesthetists are in the unique position of providing peri‐operative care to their patients, especially in cardiac and neurosurgery. If RIC proves to be beneficial, then anaesthetists may be at the forefront of providing peri‐operative organ protection to their patients. Even if RIC is not realised as a protective intervention, an understanding of mechanisms may lead to development of pharmacological agents that may be administered peri‐operatively by anaesthetists, in the hope of protecting vulnerable patients from myocardial injury following reperfusion. Over the years, research and development has reduced the risks of cardiac interventions and surgery dramatically. Remote ischaemic conditioning may help us reduce this even further.No external funding or competing interests declared.


IIA functions in the early stages delivering membrane for the initial formation of the autophagosome, whereas myosin IC and myosin VI are involved in the final stages providing specific membranes for autophagosome maturation and its fusion with the lysosome.Myosin motor proteins working together with the actin cytoskeleton drive a wide range of cellular processes. In this review, we focus on their roles in autophagy – the pathway the cell uses to ensure homeostasis by targeting pathogens, misfolded proteins and damaged organelles for degradation. The actin cytoskeleton regulated by a host of nucleating, anchoring and stabilizing proteins provides the filament network for the delivery of essential membrane vesicles from different cellular compartments to the autophagosome. Actin networks have also been implicated in structurally supporting the expanding phagophore, moving autophagosomes and enabling efficient fusion with the lysosome. Only a few myosins have so far been shown to play a role in autophagy. Non‐muscle myosin  Macroautophagy, hereafter referred to as autophagy, is a tightly regulated pathway that sequesters cytoplasmic material, damaged organelles, misfolded protein aggregates or invading pathogens into characteristic double‐membrane structures called autophagosomes, which fuse with lysosomes to allow content degradation In this review, we will present a brief overview of the current knowledge of the autophagy pathway and highlight key role(s) of the actin cytoskeleton, myosin motors and associated cargo adaptor proteins in different stages of this vital cellular process.de novo actin filament formation, such as the ARP2/3 complex, formins and nucleation promoting factors In eukaryotic cells, actin is one of the most abundant and highly conserved proteins. The 42‐kDa globular actin (G‐actin) monomer can polymerize into filamentous actin (F‐actin) The general importance of the actin cytoskeleton in autophagy was demonstrated using F‐actin depolymerizing drugs, such as cytochalasin D and Latrunculin B, which inhibit autophagosome formation In the human genome, 39 myosins belonging to 12 distinct classes are expressed This dynamic pathway from autophagosome biogenesis to lysosomal degradation can be divided into several morphological and functional stages: (i) initiation and phagophore expansion, (ii) autophagosome closure and maturation, and (iii) autolysosome formation and degradation Figure . AutophaUnder conditions of low nutrients or other stress signals, autophagosome biogenesis is triggered by the UNC51‐like kinase  complex , which is regulated by the cellular energy sensor, AMP‐activated protein kinase (AMPK), and the nutrient sensor, mTOR complex 1 (mTORC1) trans‐Golgi network (TGN) to the phagophore where they are thought to deliver membranes for expansion In addition to the ER, other membrane sources also contribute to the propagation and elongation of the phagophore membrane, including the plasma membrane Two ubiquitin‐like conjugation systems involving numerous autophagy (ATG) proteins ultimately lead to the covalent modification of LC3 (microtubule‐associated protein 1 light chain 3) with phosphatidylethanolamine (PE) Amphisomes or autophagosomes fuse with lysosomes giving rise to the autolysosome Although autophagy has long been considered a non‐selective degradative pathway for cytoplasmic material during nutrient deprivation, more recently cargo‐specific autophagy receptors have been identified that lead to the selective degradation of specific cargoes, such as damaged mitochondria, protein aggregates and invading pathogens Salmonella bacterium invade cells and become resident in a Salmonella‐containing vacuole (SCV), where they proliferate. The first danger signal marking the escape of bacteria from the vacuole into the cytosol is the rupture of these vacuolar membranes Pathogens including the Mycobacterium tuberculosisTo maintain mitochondrial homeostasis, damaged mitochondria are targeted to autophagosomes for degradation using the PINK1/Parkin‐dependent pathway Genetic knock out of five autophagy receptors  using the CRISPR/Cas9 system leads to a block in mitophagy CAPZB), an actin capping protein that binds to the barbed end of actin filaments Actin filaments have been shown to colocalize with early omegasomes before their association with LC3 suggesting a role for actin in the initial stages of autophagosome formation linked to the PI3P generation step  are expressed in mammalian cells. NMM2A is encoded by myosin heavy 9 (MYH9), 2B by MYH10 and 2C by MYH14 in vitro non‐phosphorylated NMM2 exists in a compact inactive state (10S state) in which the folded tail interacts with the motor domains. This inhibits its ATPase activity by reducing its rate‐limiting Pi release rate ∼1000 fold and prevents filament assembly The activity of the NMM2s is regulated by RLC phosphorylation by more than 12 different kinases Drosophila and in mammalian cells, the ULK1/ATG1 kinase phosphorylates and activates a novel myosin light chain kinase , which in turn phosphorylates the myosin RLCs during starvation and leads to activation of NMM2A During autophagosome biogenesis, NMM2A is activated downstream of the serine/threonine kinase ATG1  that is essential for induction of autophagosome formation under starvation conditions , which is a downstream effector of Rho GTPases, causes accumulation of enlarged autophagosomes Actin comet tails, which are branched actin filaments produced by the ARP2/3 complex on the surface of particles, have been implicated in generating the force that drives the movement of bacterial pathogens, endosomes and lysosomes Myosin VI (MYO6) is the only myosin that moves towards the minus end (pointed end) of actin filaments, in the opposite direction to all the other myosins MYO6 has unique structural and functional properties. It consists of a conserved N‐terminal motor domain, a short lever arm domain binding to one calmodulin, a tail domain with a three‐helix bundle, a single alpha helical domain (SAH) and a C‐terminal cargo‐binding domain that interacts with a host of specific adaptor proteins. There is a unique 53‐amino‐acid insert – the reverse gear – in between the motor domain and the lever arm that is stabilized by binding a calmodulin and is responsible for the reverse directionality of MYO6 movement along actin filaments by repositioning of the lever arm in vivo still requires further investigation.MYO6 displays a number of unusual features, not only the reverse directionality, but also a large step size of about 36 nm despite a short conventional lever arm. To account for this large step size, the proximal three‐helix bundle in the tail may unfold to form a lever arm extension Since MYO6 is the only pointed‐end directed myosin motor, it is involved in a unique spectrum of cellular functions ranging from anchoring the actin cytoskeleton to the plasma membrane in the highly specialized stereocilia of the inner ear, to clathrin‐mediated endocytosis in polarized epithelium, to exocytosis/secretion at the Golgi and plasma membrane, to the trafficking and sorting of cargo at early endosomes A number of MYO6 adaptor proteins – NDP52, OPTN, TAX1BP1 and TOM1 – have important roles in both the early and late phases of autophagy  is a monomeric myosin of class I, which associates with cholesterol‐enriched lipid rafts and regulates cellular cholesterol homeostasis MYO1C is widely expressed in most eukaryotic cells. It is enriched in dynamic regions of the plasma membrane, but is also present in the nucleus and on intracellular tubules and vesicles An insight into the molecular role of MYO1C in these diverse pathways was provided by the discovery of a spatial association between MYO1C and lipid rafts. This motor is recruited through its PH‐domain to cholesterol‐enriched micro‐domains at the plasma membrane and also to membrane tubules in the endocytic recycling pathway The loss of MYO1C not only changes the cellular distribution of lipid rafts, but also leads to a significant increase in total cellular cholesterol and enlargement of late endosomes and lysosomes. This swelling of the late endocytic compartment in MYO1C‐depleted cells is, however, not caused by storing the increased cholesterol in lysosomes as described for lysosomal storage diseases, such as Niemann‐Pick Type C In this review, we have summarized how actin networks regulated by an array of associated nucleating, polymerizing and stabilizing proteins generate membrane curvature and act as a structural scaffold for the expanding phagophore (stage 1, Figure Dysfunction of this pathway occurs in a growing number of human diseases that either affect multiple systems, e.g., cancer, defects in the immune response, metabolic dysfunction and vascular disease or target specific organs, such as the central nervous system, the heart, skeletal muscle or bones Editorial ProcessClick here for additional data file.


HCV) treatment landscape, with rates of sustained viral response in excess of 90%. As these new agents are expensive, an important question is whether to focus on minimizing the consequences of severe liver disease, or reducing transmission via ‘treatment as prevention’. A back‐calculation model was used to estimate the impact of treatment of mild, moderate and compensated cirrhosis on incident cases of HCV‐related end‐stage liver disease/hepatocellular carcinoma (ESLD/HCC). In addition, a dynamic model was used to determine the impact on incidence and prevalence of chronic infection in people who inject drugs (PWID), the main risk group in England. Treating 3500 cirrhotics per year was predicted to reduce ESLD/HCC incidence from 1100 (95% CrI 970–1240) cases per year in 2015 to 630 (95% CrI 530–770) in 2020, around half that currently expected, although treating moderate‐stage disease will also be needed to sustain this reduction. Treating mild‐stage PWID was required to make a substantial impact on transmission: with 2500 treated per year, chronic prevalence/annual incidence in PWID was reduced from 34%/4.8% in 2015 to 11%/1.4% in 2030. There was little overlap between the two goals: treating mild stage had virtually no impact on ESLD/HCC within 15 years, but the long timescale of liver disease means relatively few PWID reach cirrhosis before cessation of injecting. Strategies focussing on treating advanced disease have the potential for dramatic reductions in severe morbidity, but virtually no preventative impact.New direct‐acting antivirals have the potential to transform the hepatitis C ( CrIcredibility intervalDAAdirect‐acting antiviralELSDend‐stage liver diseaseHCChepatocellular carcinomaHEShospital episode statisticsIFNinterferonONSOffice of National StatisticsPWIDpeople who inject drugsRIBribavirinLiver disease is a growing public health problem in the UK, with a fivefold rise in liver‐related mortality in the under 65s since 1970 The key risk group for HCV are people who inject drugs (PWID) with approximately 85% of prevalent infections due to injecting drug use in England Historically, the number of people treated for HCV has been low. Of approximately 160 000 adults chronically infected in England NHS England has recently announced a budget of £190 million for new treatments in 2015, primarily for treating those with cirrhosis We utilized two separate models for this analysis, based on previously published methods. The first was a back‐calculation model of HCV disease progression used to predict incident cases of ESLD/HCC in England, but does not include HCV transmission Age‐specific data from Hospital episode statistics (HES) on ESLD and HCC, and Office of National Statistics (ONS) data on HCC mortality were used as disease endpoints. Information on the probabilities of progressing between disease states was taken from published literature and combined with the above data to derive estimates of the underlying HCV incidence and number of individuals in each disease state over time We used a dynamic, deterministic, compartmental model of HCV transmission (Appendix 2) and disease progression Fig.  among PWWe assumed the risk of transmission or acquisition of HCV is independent of disease stage or duration of injecting. We also assumed that the HCV epidemic among PWID is at a stable steady‐state in 2015, based on the stable prevalence exhibited among PWID in contact with drugs services from 2003 to 2013 The model was calibrated to estimates of the proportion of PWID with chronic HCV in England at an estimated 34% (95% CI 31–37%), based on 45% (95% CI 41–49) anti‐HCV prevalence in this group Estimates of the impact of treatment were derived by assuming that a fixed number of individuals in different disease states receive treatment each year. We do not consider proportions currently diagnosed or increases in diagnosis that may be required to fulfil certain treatment scenarios, but place a 70% cap on the maximum proportion of infected individuals within a particular disease state that may be treated within any year.Current standard treatment was assumed to be pegylated interferon (IFN) and ribavirin (RIB), which is assumed to continue to be used for patients that do not receive new DAAs. For the HCV disease burden model, age‐specific SVR rates for mild, moderate and cirrhosis stages were used from the Trent HCV cohort study DAA treatments were assumed to become available from 2015, with SVR rates of 90% for mild/moderate stages, and 80% for those with cirrhosis. These are somewhat lower than SVR rates observed in trials We then explored the impact of treating mild‐/moderate‐stage patients with new DAAs, assuming that roll‐out in these patients would start from 2016. The different scenarios are summarized in Box Box 1In the transmission model base‐case, half of the total number treated were allocated as active PWID. This assumption is intended to test the potential reductions in incidence that could be achieved. Similarly to the cap of 70% treated annually in cirrhotics, the maximum proportion of PWID treated per year in any stage was also set at 70%, as there are fewer moderate‐stage PWID. Awareness of infection in PWID is around 50% A key assumption is that treatment with pegylated interferon and ribavirin continues for groups that do not receive DAAs. However, there may be reluctance among clinicians and patients to continue the use of IFN‐based therapy in the DAA era. We therefore examined the impact of the scenarios with scale‐up in new DAAs but no further use of IFN‐based regimens.We explored areas of uncertainty by varying key parameters in sensitivity analyses. There is currently little evidence on real‐world SVR rates for new DAAs by disease stage, so we compared scenarios with higher rates of 97.5% and 90% for all groups and lower rates of 90%, 80% and 70% in mild, moderate and cirrhosis groups, respectively. Post‐SVR progression rates are also uncertain; we tested the impact of assuming no post‐SVR progression in those with cirrhosis, and a scenario in which post‐SVR progression of cirrhotics was half that of non‐SVR (compared to 10 times lower from cirrhosis to ESLD and 4 times lower from cirrhosis to HCC at base‐case DAAs for cirrhosis only) from 2015 was predicted to reduce annual incidence of ESLD/HCC to 640 cases per year (95% CrI 530–770) in 2020 compared with 1240 under current levels of IFN‐based treatment (95% CrI 1080–1440)  more incident cases of ESLD/HCC in 2020 (3.3% higher) and 59 (95% CrI 44–76) more in 2025 (7.8% higher). Further details are given in supplementary materials.DAAs for cirrhosis and moderate), largely averts the predicted rebound in incident cases of ESLD/HCC, with incident cases not exceeding 600 per year and slowly beginning to decline from a maximum of 600 (95% CrI 480–770) in 2025  had limited additional impact: virtually no difference was observed by 2020 compared to DAAs for cirrhosis and moderate, and even at 2025 the reduction in annual incident cases was only 16 cases (95% CrI 12–20). This reflects the long lead‐time before severe disease develops in those at mild stage.Treating 5000 moderates per year with new DAAs from 2016, in addition to cirrhotics  with an annual incidence rate of 4.8% (95% CrI 3.6–8.1%). In this equilibrium state, the model predicts 79%, 16%, 5% in the mild, moderate, cirrhosis or later stages, respectively.DAAs for cirrhosis only) had negligible impact on predicted incidence and prevalence of chronic infection among PWID due to the rarity of advanced disease in this population. Only 7474 PWID (95% CrI 3834–11 782) were treated over the 15 years, and prevalence was reduced to 32% (95% CrI 27–35%) and incidence to 4.4% (95% CrI 3.6–7.9%) by 2030. With standard IFN/RBV treatment in mild and moderate stages (1000 per year in each) alongside treatment of cirrhotics with DAAs, prevalence was reduced to 25% (95% CrI 21–29%) and incidence to 3.5% (95% CrI 2.6–6.6%) by 2030. Treating 2500 moderate‐stage patients per year with DAAs (DAAs for cirrhosis and moderate) had some impact, with chronic prevalence estimated at 24% (95% CrI 20–28%) and incidence at 2.8%(95% CrI 2.1–5.7%) in 2030. However, by 2021, there are fewer PWID in the moderate stage than available treatments; in other words, as there are only 16% of PWID in the moderate stage, the pool of people to treat at this stage runs out. The additional scale‐up of DAAs to mild stage, however, with 2500 treated per year  reduced chronic prevalence to 11% (95% CrI 6–15%) and incidence to 1.4% (95% CrI 0.7–3.5%) by 2030. In this scenario, nearly two‐thirds of the mild stage were treated, with a total of 68 179 PWID (95% CrI 61 236–75 210) treated over 15 years. It should be noted that the incidence rate of chronic infection is approximately 25% lower than the incidence rate of HCV exposure, due to spontaneous clearance Estimated prevalence and incidence of chronic infection among PWID are shown in Fig. vs base‐case in 2020) under 90% SVR rates for all disease stages and by 120–140 cases under 97.5% SVR rates (90% for mild/moderate and 80% for cirrhosis in the base‐case). With 90% SVR, marginal differences (<2%) are found for HCV prevalence among PWID in all scenarios. However, a 97.5% SVR results in 22% lower HCV prevalence among PWID in 2030 for the DAA for all scenarios compared to base‐case.With better SVR rates, incident cases of ESLD/HCC are reduced by approximately the same degree in all scenarios, by around 60–80 cases per year (13% reduction vs base‐case in 2020) for the DAAs for cirrhosis only scenario, with negligible difference (<1%) in HCV chronic prevalence among PWID in 2030 compared to base‐case. Cases of ESLD/HCC are around 130 higher for scenarios that treat pre‐cirrhotic stages, as the additional benefits of treating moderate stage are less. HCV chronic prevalence among PWID in 2030 is 5–10% higher compared to base‐case for pre‐cirrhotic scale‐up scenarios.With worse SVR rates for moderate and cirrhosis stage , incident ESLD/HCC was predicted to be around 80 cases higher  if progression is only halved post‐SVR compared to the baseline rates, and up to 160 fewer cases if progression is halted entirely (25% lower than base‐case), although the difference increased over time. For scenarios that treat precirrhotic stages, changes in post‐SVR progression rates have less impact, as fewer patients progress to cirrhosis. No difference was seen in impact on HCV prevalence among PWID with variations in post‐SVR progression rates due to the very small number of PWID in later disease stages. Plots of predicted ESLD/HCC and prevalence/incidence of chronic HCV infection among PWID under the different sensitivity analyses are available in supplementary materials.Changes to post‐SVR progression rates had a greater impact on incident cases of ESLD/HCC, although the variation in assumed values was fairly extreme. For DAA for cirrhosis and moderates scenario, and 74% higher in the DAA for all stages scenario . If 60%, 40%, 20% of mild, moderate and cirrhotic treatments, respectively, are allocated to PWID (50% at base‐case), then more impact is achieved in the DAA for all stages scenario, with HCV chronic prevalence 25% lower in 2025 ; marginal differences (<2%) are seen for other scenarios.With fewer treatments allocated to PWID (25% compared to 50% at base‐case) there was less impact on HCV chronic prevalence among PWID, at 2030 a relative 13% higher in the These analyses suggest that targeting new DAAs to people with cirrhosis will result in a rapid reduction in incident cases of ESLD/HCC within 2–3 years, to around half of that currently predicted in 2020, but with little impact on HCV incidence among PWID. Due to lower SVR rates in those with cirrhosis, continued post‐SVR progression  and rising numbers developing cirrhosis, treating those at moderate disease stage is also required to prevent a rebound in incident cases of ESLD/HCC. The total number of individuals either living with cirrhosis or having achieved SVR while cirrhotic was predicted to steadily increase, rising from 9330 (95% CrI 7090–12 020) in 2015 to 16 760 (95% CrI 13 730–21 000) in 2025, with an increasing number of moderate stage developing cirrhosis each year. Therefore, a rebound in ESLD/HCC (following ‘saturation’ of cirrhotic treatment) is to be expected unless individuals can be prevented from reaching cirrhosis in the first place. Re‐treatment may mitigate the increased risk of treatment failure in patients with cirrhosis to some extent, but there is still the risk of continued liver disease. The extent to which the risk of severe liver disease persists post‐SVR is not yet fully understood, although some studies suggest that fibrosis can be reversed New DAAs also offer the potential to reduce incidence and chronic prevalence in the PWID population by two‐thirds within 15 years. However, this requires treatment of those at mild stage, as the majority of PWID do not progress beyond mild stage during their injecting career. Treating PWID at moderate stage showed a 10% reduction in chronic prevalence, from 34% to 24%, but as a relatively small proportion of active PWID progress beyond mild stage, there are not enough moderate‐stage PWID to treat to make a substantial impact on transmission. This is in contrast to predicted incident cases of ESLD/HCC, which was only affected by treating moderate and cirrhotic stage disease within the time frame examined here.By testing the impact of the same treatment scenarios within both a burden projection model and a dynamic transmission model, the impact on different aspects of harm reduction can be compared directly. This study provides the first population‐level assessment of the potential impact of new DAAs in England and the forthcoming NHS England treatment programme, quantified with total numbers treated in the infected population and in PWID. The proportion of treatments that are assumed to be ‘allocated’ to PWID is high, with the aim of assessing the potential impact rather than what might be feasible. The proportion of PWID treated will not affect the conclusion that the two reduction targets of transmission and severe disease have little overlap, but clearly if a lower proportion of those treated are active PWID, there will be a smaller reduction in transmission.The disease burden model combines observed data on ESLD/HCC and HCC mortality from HES and the ONS, progression rates from the literature and estimates of overall population prevalence. The model should therefore provide an accurate picture of the current and future disease burden that England faces, and the potential impact of treatment. The main limitations are that there are no recent estimates of population prevalence; observed HES data may underreport HCV‐related ESLD/HCC to some extent; and the assumed model structure necessarily makes assumptions regarding relative risks of age‐specific progression and the distribution of age at infection.The transmission model also has areas of uncertainty, primarily surrounding estimation of size of PWID population, natural history of injecting We assume the risk of transmission or acquisition of HCV is independent of disease stage or duration of injecting. Several studies have noted that HCV prevalence rises quickly the first few years of injecting and then stabilizes Key uncertainties include the actual SVR rates of new treatments in practice, which are likely to be worse than those observed in clinical trials, and the lack of long‐term outcome data in those that achieve SVR where cirrhosis has already developed. Crucially, it is also uncertain to what extent SVR rates are reduced in patients with cirrhosis compared to pre‐cirrhotic disease stages. Finally, it is not known to what extent treating DAA‐failures with other regimens will be viable, with issues such as cross‐class drug resistance still being investigated. Our base‐case assumption was for no re‐treatment, but we sought to consider alternatives by testing assumptions of higher overall SVR rates, and other uncertainties listed above, in sensitivity analyses.These analyses show that the major concerns relating to HCV, rising severe liver disease and ongoing transmission, can be addressed with the advent of new DAAs. Treating those with cirrhosis fulfils the short‐term goal of reducing ELSD/HCC, although treatment of moderate stage is needed to prevent a subsequent rebound. Treatment of mild‐stage, active PWID is required to substantially reduce HCV transmission, which must be addressed if the long‐term goal of elimination of HCV as a significant public health concern is to be achieved.Progress towards reducing ESLD/HCC should be immediately observable via HES data and liver‐related mortality, although reductions in transmission will be harder to detect. Changes in incidence cannot easily be observed directly, and falling chronic prevalence will occur slowly and also be difficult to monitor accurately, with current monitoring via anonymous surveys testing for antibodies With a budget of £190 million for new DAAs announced in June 2015 and current focus on treating those with cirrhosis The key issue for any managed, targeted treatment strategy is whether individuals in the appropriate groups can be identified and treated in a timely way. One potential strategy would be to monitor patients using fibrosis scans and only initiate treatment when a defined high‐risk fibrosis stage is reached The scenarios here also require a certain quota of people to be treated each year. While it is likely that the majority of those with cirrhosis will be diagnosed, treating 70% of the remaining pool each year may be difficult to achieve in practice. Late diagnosis of cirrhosis will result in continued high levels of severe liver disease. Treating 5000 mild and 5000 moderate per year would be a relatively small proportion of the current infected population, but as the pool of diagnosed individuals diminishes, sustaining high numbers in treatment may be difficult unless testing, diagnosis and patient engagement improve. Diagnosing and treating sufficient numbers of PWID may be difficult, although recent advancements in case‐finding through dried blood spot testing and voluntary opt‐out in prison are likely to increase diagnosis rates in this population With the arrival of new DAA treatments, the outlook is extremely good for HCV‐infected patients, with the risk of severe HCV‐related liver disease being markedly reduced. However, SVR rates in cirrhotic patients may be lower than pre‐cirrhotic patients, treatment of cirrhosis may not prevent further disease progression in all individuals, and treatment of cirrhotic patients will have little benefit on preventing new HCV infections. Therefore, focussing solely on cirrhotics is not a tenable long‐term strategy if continued reductions in incident cases of ESLD/HCC and reductions in transmission are to be achieved. NHS England is currently rolling out new DAAs to those with cirrhosis, but treatment of other groups will need to follow quickly. Providing equitable access to expensive treatments will require a difficult balance between increasing the budget for treatment and negotiating lower prices.Data S1. Materials.Click here for additional data file.


P < 0.0001). The association between RV‐WI and third year wheezing was unchanged after adjustment for potential confounders such as eosinophilia and atopic eczema. RV‐WI is a robust and independent risk factor for third year wheezing in low risk children without parental asthma. Future research will identify and protect those children at increased risk for RV‐WI.Rhinoviruses may be pathogens contributing to the development of childhood wheezing. However, their role in low risk infants without an asthmatic predisposition is unknown. Knowing which healthy, low risk children are at increased risk for childhood wheezing after rhinovirus wheezing illness (RV‐WI) in infancy, might help in developing prevention and treatment strategies for childhood wheezing. The aim of this study was to determine the association of medically attended wheezing at the age of three with RV‐WI in the first year of life in low risk children without parental asthma. In a low risk, prospective birth cohort study, we followed 181 healthy born children from birth through the third year of life. We considered children ‘low risk’ if neither parent had a doctor's diagnosis of asthma. We determined infant RV‐WI by parent‐reported wheezing (based on daily logs) and simultaneous molecular rhinovirus detection in the first year of life. Respiratory function and blood eosinophil count were both measured in the first month of life. The primary outcome, third year wheezing, was defined as the use of prescribed inhaled asthma medications together with a doctor's visit for respiratory symptoms in the third year of life. We calculated the association of RV‐WI with medically attended third year wheezing and other known possible risk factors for wheezing at the age of three. Among low risk children, third year wheezing was observed in 7 out of 18 (39%) children with versus 10 out of 163 (6%) children without infant RV‐WI (OR 9.7, 95% CI 3.1–33.5,  Rhinoviruses are increasingly recognised as the most common pathogens causing lower respiratory tract infections a priori increased risk of asthma. If healthy infants are at increased risk of developing wheezing after RV‐WI in infancy, we could identify, follow‐up and possibly treat those at high risk for RV‐WI. Therefore the aim of this study was to answer the following questions: (1) what is the association of wheezing at the age of three after infant RV‐WI in children without parental asthma? (2) Is this association influenced by known risk factors for wheezing such as obstructive respiratory function at one month of age, atopic characteristics or known environmental risk factors for wheezing? To answer these questions, we followed healthy children without parental asthma from birth until the age of three in a prospective, community‐based birth cohort study.Previous research has shown that RV‐WI is a strong predictor of subsequent wheezing and asthma, especially in high risk children with an atopic background In a prospective, community‐based birth cohort study, children born in the University Medical Center Utrecht and the Diakonessen Hospital Utrecht were included. Study design and recruitment criteria have been published previously Demographic, obstetric, atopic and environmental characteristics were assessed using data from the hospital delivery files  and from standardized questionnaires completed by parents at one month, one year and three years of age as described in more detail previously At one month of age , respiratory function was tested and blood was drawn to measure the absolute eosinophil count. The single occlusion technique was used to measure compliance and resistance Nasopharyngeal swab samples were sent in 2 mL of viral transport medium and frozen at −80°C until polymerase chain reaction (PCR) assays were performed. Trained analysts performed real time PCR assays to detect viral pathogens such as rhinoviruses and respiratory syncytial virus (RSV) as described in more detail previously Parental asthma was defined as asthma ever diagnosed by a physician in one or both parents. RV‐WI in the first year of life was defined as the simultaneous presence of parent‐reported wheezing for ≥ 2 days (based on daily logs) and molecular rhinovirus detection in viral samples collected during respiratory episodes in the first year of life 2‐sympathomimetics) together with a doctor's visit for respiratory symptoms in the third year of life. Respiratory symptoms were defined as any kind of respiratory symptoms for which parents felt the urgency to visit the general practitioner. The secondary outcome, physician‐diagnosed wheezing, was composed of a doctor's diagnosis of wheezing or the use of prescribed inhaled asthma medications (corticosteroids and/or β2‐sympathomimetics) in the third year of life. A doctor's diagnosis of wheezing was defined according to the International Classification of Primary Care (ICPC) of either wheezing (R03) or asthma (R96).The primary outcome of the study, medically attended third year wheezing, was defined as the use of prescribed inhaled asthma medications  for this odds ratio and to adjust for confounders. We included the two variables showing the strongest association with RV‐WI in regression models as potential confounders. Results are presented as odds ratio with the associated 95% confidence interval (CI) and Since missing values usually do not occur randomly, exclusion of participants with missing values  may result in biased estimates. Therefore we used single imputation techniques  to address missing values, including missing outcome values. Respiratory function was measured successfully in 81 of 181 children (45%) and respiratory function measurements were therefore not imputed. The major reasons for failure of respiratory function measurement were technical issues  (42%) and no sleep or a too short period of sleep (52%). Other missing values did not exceed 5%, except for day care attendance (9%), atopic eczema (19%) and blood eosinophil count (20%).We found that RV‐WI during the first year of life was highly associated with third year wheezing, also after adjustment for known risk factors for wheezing. The main characteristics of the children with and without RV‐WI in the first year of life are summarized in Table We followed 387 neonates throughout the first year of life, including 290 children without parental asthma. Of those 290 children, 181 (62%) completed three‐year follow‐up  vs. 0.45 * 109/L (SD 0.55 * 109/L), P = 0.02), measured at one month of age and a higher prevalence of atopic eczema during the first year of life than the group without RV‐WI  (Table The 181 children who completed three‐year follow‐up reported 271 episodes of respiratory tract infections in the first year of life. Eighteen out of 181 children (10%) developed RV‐WI in the first year of life and 65 out of 181 children (36%) developed RV‐RI. No significant differences were observed between infants who did and who did not develop RV‐WI in the first year of life regarding known possible confounders: male sex, gestational age, respiratory function, number of siblings, RSV LRTI, day care attendance, maternal smoking, high level of education of one or both parents and breastfeeding. The RV‐WI group however had a higher mean eosinophil count (0.80 * 10P < 0.0001). Children with and without third year wheezing did not differ in gestational age, sex, number of siblings, daycare, breastfeeding, parental atopic characteristics, atopic eczema in the third year of life, blood eosinophil count at one month of age and respiratory function at one month of age (data not shown). The children with wheezing during the third year of life did have a higher percentage of atopic eczema during infancy (11 (65%) vs. 55 (27%), P = 0.001)  developed wheezing during the third year of life, compared to 10 out of 163 (6%) children who did not have RV‐WI in the first year of life  vs. 55 7%, P = 0P = 0.38). One out of 17 children with third year wheezing (6%) had RSV LRTI during infancy, compared to 17 out of 163 children without third year wheezing .Third year wheezing was not associated with RV‐RI .When we adjusted the third‐year wheezing risk after RV‐WI for eczema in infancy and for blood eosinophil count at one month of age, the risk was not influenced .A sensitivity analysis using the alternative outcome physician‐diagnosed wheezing showed similar results. Third‐year physician‐diagnosed wheezing was diagnosed in 7 out of 18 (39%) of children with RV‐WI in the first year of life and in 22 out of 163 (13%) children without RV‐WI in the first year of life  during infancy is strongly and independently associated with wheezing at the age of three. The increased risk seems to be independent from known risk factors for wheezing, such as early infant eosinophilia, obstructive respiratory function, or atopic eczema in the first year of life.et al. showed similar results; RV‐WI was associated with persistent wheezing and asthma  et al. showed that recurrent wheezing after hospitalization for bronchiolitis was associated with RV and not with other viral etiology Our findings in low risk children are consistent with results of previous studies, showing the role of rhinoviruses as contributors in wheezing and asthma later in life in high‐risk children or in children hospitalized for wheezing. The Childhood Origins of ASThma cohort (COAST), a high‐risk cohort of 285 children with at least one parent with respiratory allergies, demonstrated that RV‐WI during infancy was the strongest predictor of wheezing at 3 years of age (OR 6.6). Furthermore, RV‐WI during infancy increased the asthma risk at 6 years of age independently from aeroallergen sensitization The RV‐WI group had a higher eosinophil count at one month of age, and a higher prevalence of atopic eczema during the first year of life than the group without RV‐WI. Eosinophilia was independently associated with and temporarily followed by RV‐WI, since RV‐WI did not occur before the age of one month. This suggests that eosinophilia (and probably infant eczema) and RV‐WI have a synergistic effect on wheezing later in childhood. However, since correcting for eosinophila and infant eczema did not decrease the effect of RV‐WI on wheezing in the third year of life, eosinophilia and infant eczema alone cannot fully explain the risk of wheezing in the third year of life. A population‐based cohort study empowered to study the interaction between atopy, RV‐WI and wheezing later in childhood could answer the question if this synergistic effect exists.et al. showed similar results: children with a decreased respiratory function early in life were at increased risk of developing both RV‐WI as well as childhood wheezing Respiratory function measured at one month of age did not significantly differ between infants with and without RV‐WI in infancy. However, a trend towards lower compliance of the respiratory system in infants with RV‐WI in infancy was found. The insignificance might be due to small sample size. A recent unselected birth cohort study of Van der Gugten The strengths of this study are et al. showed that RV presence itself was not associated with wheezing at age 4, while RV‐WI was The limitations of this study should be discussed. First, we only performed PCR assays during respiratory episodes. Hereby we can only speculate about the causal relationship between the presence of RV and wheezing illness. However, this relation appeared to be specific, and was absent for rhinovirus respiratory tract infection without wheezing (RV‐RI). Accordingly, in a recent unselected birth cohort study, Van der Gugten Second, only 181 of 290 children (61%) completed the follow‐up. However, baseline characteristics of participants and of children that were lost‐to‐follow‐up were similar, thereby reducing the risk of selection bias (see Supplementary table 1).apriori increased asthma risk, we followed a low risk birth cohort, which we defined as non‐parental asthma. Although several studies show increased risks of atopy and asthma due to genetic factors Third, to create a population of children without an et al. showed that parental viral swab collection results in higher sampling yields when compared to swab collection by a trained nurse, without any difference in severity of symptoms or loss of viral recovery rate Fourth, viral swabs were in this study performed by parents. This might be considered a limitation of this study. However, in a randomized study Van der Zalm After prolonged follow‐up of these low risk children, establishment of rhinovirus as an independent risk factor of childhood wheeze and / or asthma would generate several ways to predict and prevent early childhood respiratory infections and wheeze / asthma. Careful follow‐up of the individuals at risk and, possibly, preventive treatment will hopefully be available in the near future.We conclude that RV‐WI in infancy is a robust risk factor for wheezing at the age of three in children without parental asthma, independent from other known risk factors for wheezing. Further follow‐up will show whether these children will have an increased asthma risk at school age. Ultimately, preventive treatment, developed to modify immune responses to viral infection or to prevent rhinovirus infection itself may help.LB received research funds or consultancy fees from AbbVie, MedImmune, Gilead, Ablynx JanssenPharmaceuticals .Additional supporting information may be found in the online version of this article at the publisher's web‐site.Table S1. Characteristics of the Study Population.Click here for additional data file.


CVD) constitutes a major public health threat worldwide, accounting for 17.3 million deaths annually. Heart disease and stroke account for the majority of healthcare costs in the developed world. While much has been accomplished in understanding the pathophysiology, molecular biology and genetics underlying the diagnosis and treatment of CVD, we know less about the role of epigenetics and their molecular determinants. The impact of environmental changes and epigenetics in CVD is now emerging as critically important in understanding the origin of disease and the development of new therapeutic approaches to prevention and treatment. This review focuses on the emerging role of epigenetics mediated by insulin like‐growth factors‐I and ‐II in major CVDs such as heart failure, cardiac hypertrophy and diabetes.Cardiovascular disease ( Epigenetics is an emerging frontier of science that involves the study of gene regulation when the DNA‐primary structure remains intact. While epigenetics refers to single genes or sets of genes, epigenomics denotes the global analyses of epigenetic changes across an entire genome transient or permanent and it is difficult to detect or associate them with a certain phenotype. Epigenetic changes can be elicited by metabolic alterations, environmental stress, toxicants, viruses and immunity de novo formation of epigenetic marks in each generation. Most of the DNA methylation marks (expressed as hypo‐ or hypermethylation clusters) are cleared during fertilization and only certain characters are someway preserved via cytosine‐phospo‐guanine (CpG) methylation, when the germline was challenged by mating with a non‐transgenic phenotype Factors that induce epigenetic modifications can be i) Are the epigenetic changes preserved at key loci via germ lines? If yes, how would IGF‐fluctuations affect them? (ii) Is their maintenance based on the magnitude and/or the timing of the IGF‐stimuli? (iii) Are the epigenetic marks erased and/or reset in the presence or absence of IGFs? and (iv) What are the mechanisms responsible for the formation of epigenetic marks and what role do IGFs have in this process?Epigenetics represents crucial regulatory mechanisms in evolution, development, ageing, adaptation and disease. Therefore, making correlations between environmental exposure, epigenetic marks and disease should be of high priority in the near future. It is important to elucidate how biological systems adapt or not to environmental changes. The dynamics of epigenetic characters show that organisms respond either reversibly or irreversibly to environmental signals and that modifies tissue‐ and cell‐type‐specific gene programmes. During ontogenesis, epigenetic marks are associated with high biochemical plasticity. Growth factors, cytokines and adhesion molecules govern multiple cellular processes in response to microenvironmental changes during development. To date, little is known about the extracellular signalling and the mechanisms that allow adaptation in response to the changes in microenvironment. Among all, growth factors can be critical determinants of both the onset and progress of the epigenetic modifications. For example, insulin like‐growth factor (IGF I) can act in both systemic‐ and tissue‐specific manners altering both metabolic and non‐metabolic signalling pathways that can induce epigenetic changes for the entire life span of an organism The IGF system is comprised of five related receptors, three ligands  and six IGF‐binding proteins (IGFBPs) i) One target of this signalling cascade can be the mTOR molecule . Insulin like‐growth factors‐I, ‐II and insulin bind to their receptors by activating the PI3K/AKT/mTOR pathway and the Ras/Raf‐1/MEK/ERK signalling cascade Nutrient‐sensitive PI3K–AKT–mTOR pathways have a crucial role in regulating the balance between quiescence and proliferation of progenitor cells in many tissues including the heart muscle There are a few signalling mechanisms triggered by ligand‐binding to IGF‐IR and IR that have the potential to mediate skeletal and cardiac muscle epigenetics. These pathways are driven by the activation of PI3K  and AKT (protein kinase B). (ii) Another mechanism led by the IGF‐I and AKT activation is related to the functions of miR‐1, a muscle regulator, lately found to be responsible for transgenerational cardiac hypertrophy in mice (iii) The IGF‐I/AKT pathway is also involved with sugar and fat metabolism. It is known that IGF‐I, insulin and the glycolytic network regulates the development of skeletal and cardiac muscle, including progenitor cells iv) Both GH and IGF‐I are widely used as performance enhancing drugs in adult or paediatric medicine and little is known about their epigenetic implications in short or long term. Because of the hypertrophic effects observed in both skeletal and heart muscle under intensive IGF‐I treatments, it is mandatory that its epigenetic action should be thoroughly analysed. We suggest that future studies should actually include the entire ‘GH/IGF axis’, which can potentially be responsible for the regulation of histones H3 and H4 acetylation and the activation of chromatin repressors such as EZH2. All these effects would still be under the action of the IGF‐I/AKT signalling loop regardless of the initial trigger  and stromal growth factor signal through RTKs. One event that can emphasize the interference between two important RTKs in heart physiology is ischemia/reperfusion (I‐R) Cross‐talking between RTKs is probably caused because different ligands are steering the activation of key molecules such as AKT. In this context, AKT can act on glycogen synthase kinase 3 (GSK3), which is a Ser/Thr kinase with important role in the regulation of an important developmental loop led by Wnt signalling and glycogen synthesis Development is controlled through a temporal and spatial sequence of events including both activation and silencing of specific genes. Taken together, these events contribute to genetic reprogramming and they can be altered by environmental conditions that induce chromatin remodeling and/or ‘transcriptional memory’. A classic example in this sense is the ‘fertilized egg cell’, which represents a checkpoint in evolution because at this stage, most of the epigenetic modifications acquired by the parental lines are cleared, whereas a small proportion of the traits are transferred across the generations Nonetheless, the power of the current genomic technologies cannot yet analyse in‐depth the causes of the epidemiologic determinants that govern the hereditary pathologies of non‐Mendelian origin (such as many CVD cases). The ‘non‐Mendelian’ types of heredity result in transmission of epigenetic features and toning of gene expression. The first observations in mammals have been made by Dr Minoo Rassouzadegan who showed for first time that non‐Mendelian inheritance of an epigenetic colour variation can be reproduced in mice The answer is very complex. Normal and pathologic epigenetic mechanisms are based on signalling and chromatin memory. The diseased state is generated by abnormal signals, most induced by the cellular microenvironment. These signals are translated into phosphoregulatory events that precede alteration of chromatin stability, ultimately shifting gene expression. Chromatin assembly is still largely unexplored in developing tissues where phenotypic plasticity is high and signals sent by growth factors such as IGFs are critical. In addition to development, during ageing, phenotypic plasticity can be also regulated by growth factors, cytokines and extracellular matrix fluctuations leading to new epigenetic profiles. The questions that we suggest for future studies refer to the role and mechanisms of IGF‐mediated epigenetic remodelling in both development and ageing. In general, gene repression is mediated by a specific sequence of events including recruitment of polycomb group proteins (PcG), histone modifications and DNA methylation.350 has been linked to an increase in EZH2 activity while activation of Thre492 and Ser21 has been linked to a decrease in its activity. AKT phosphorylates EZH2 at Ser21 and overturns its methyltransferase activity by obstructing its binding to histone H3 27 tri‐methylation in H3 and de‐repression of silenced genes. In this way, AKT regulates the DNA methylation by acting on EZH2 and this may further contribute to development Once bound to its receptor, IGF‐IR, IGF‐I ligand triggers phosphorylation events that activate AKT/PKB signalling loop and this targets the function of PcGs igf1 gene (H3Me3K36). Even in this case, IGF‐I‐dependent changes in histone H3 modifications are associated with AKT signalling and the expression of cell survival genes Insulin like‐growth factors are implicated in many post‐translational modifications mediated by histones or in those that directly affect histone activity. For example, butyrate‐induced IGF‐II activation is correlated with distinct chromatin signatures because of histone modification. Chromatin immunoprecipitation assay indicated that association of acetyl‐histone H3 and acetyl‐histone H4 with the IGF‐IIR promoter was increased in the presence of ANGII. This study demonstrated that histone acetylation plays a critical role in IGF‐IIR upregulation during cardiac diseases and it might provide in the future a real option for targeted gene therapy in heart failure In addition to the IGF‐ligands, IGFBPs too are related to histone biology. For example, the expression of IGFBP‐3 is frequently suppressed in liver cancers and it can be reactivated by histone deacetylase (HDAC) inhibition DNA methylation is a covalent modification that occurs in mammals predominantly at cytosines followed by guanines (CpG dinucleotides) to form 5‐methylcytosines. Cytosine‐phospo‐guanine methylation is commonly associated with gene silencing. DNA methylation status has fluctuations during lifetime and has been shown to regulate biological processes underlying CVD features such as atherosclerosis, inflammation, hypertension and diabetes. Indirectly through its actions, IGFs may contribute to changes in DNA methylation.Cardiovascular disease remains the leading cause of death worldwide despite the efforts made to reduce its incidence obesity leads to a specific phenotype, namely ‘Large for Gestational Age (LGA)’ Syndrome which is a major risk factor for obesity, diabetes and even cancer in the offspring malnutrition can promote similar effects during foetal development. A classic example in this sense is the population born from mothers exposed to the Dutch Hunger Winter at the end of World War II (1944–1945). In this group, another syndrome has been identified, namely ‘Small for Gestational Age (SGA)’ transgenerational manner. Another aspect of the IGF‐induced epigenetics based on nutritional insult is the bio‐activity within the foetal microenvironment. This may drive transgenerational effects founded on specific genomic and/or epigenomic settings that can be rearranged according to the intensity and duration of the IGF fluctuations The epigenetic modifications in the foetus can have maternal origin  or they can be originated in the foetus itself. Development depends mainly on the maternal health with nutrition as a major determinant In addition to global nutrition, single micronutrient deficiency has a transgenerational impact on the offspring that can also result in dramatic effects methionineRed meat such as lamb, beef and pork may induce CVD through yet unidentified mechanisms associated with high levels of homocysteine that are associated with insulin resistance syndrome and this might involve IGFs actions Another example based on protein metabolism is given by the high levels of the plasma i) Several target genes of PPARγ transcription factors have been identified, including GATA2 or Krüppel‐like factor family et al. in their 2003 report et al. in vitro and in vivo  The PPAR genetic profiling uncovers igf‐1 gene as a PPAR‐α target with an important role in cardio‐protection. PPARα activation in the wild‐type mouse heart resulted in up‐regulation of the igf‐1 gene transcription and provided protection against cardiomyocyte apoptosis post ischemia or biomechanical stress. This confirms that igf‐1 gene is an in vivo target of PPARα and the involvement of a PPARα/IGF‐I signalling loop in cardiomyocytes protection under ischemic and hemodynamic loading conditions is a must PPARα as the main molecular player in epigenetic transgenerational inheritance Various examples emphasizing the IGFs action in modulating the CVD epigenetic origins can be given by different lipid metabolism situations It should be noted that IGFs do not act alone within the PPAR circuit but in strict relationship with IGF‐binding proteins. For example, between IGF‐I and insulin there is a feedback mechanism ensured by IGFBP‐1 To further evaluate the global and single nutrient deficiencies and their epigenetic basis as related to IGFs and CVD, we identified certain animal models that can be very useful to this matter. These prototypes are:This model resulted in an epigenetic phenotype with increased body weight, insulin resistance, hyperlipidaemia, hyperleptinaemia, and hypoadiponectinaemia ‘Western Style’‐based diet induces maternal obesity and diabetes which allowed a phenotype with metabolic dysfunction and altered DNA methylation patterns in the mouse offspring In this case, an epipolymorphism was identified in placental leptin and adiponectin genes linking glucose metabolism to the maintenance of these genes. As mentioned earlier in this review, the cohort of patients born during the Dutch Hunger Winter, exposed to famine during gestation, show timing‐ and gender‐specific variations of methylation in a number of genes involved in metabolic control The model shows a significant increase in hepatic expression of miR‐29b, miR‐103 and miR‐107 and a decrease in IR, phopsho‐AKT and phospho‐FoxO1 levels in the first generation of its offspring Molecular analyses demonstrated that diet‐induced paternal obesity in mice is associated with alteration of 414 mRNAs in the testis and 11 microRNAs in the sperm and all were associated with 25% DNA‐methylation/total DNA isolated from germ cells Maternal obesity and paternal high‐fat‐diets induce metabolic dysfunctions and β‐cell impairment in the first generation (F1) of female rats. This last model shows a phenotype characterized by obesity and glucose‐intolerance which might be involved with IGF‐biology Epigenetics induced by IGFs fluctuations are likely linked to cardiovascular medicine. To date, there are no significant reports on epigenetics as related to clinical practise or therapeutics designed for transgenerational CVD forms associated or not to endocrine factors such as IGFs. In contrast, in oncology, epigenetic inhibitors have already shown curative potential The authors have no conflict of interest to declare at this time.


Silene vulgaris and show that there is fine‐scale heterogeneity in the local distribution of the sexes within these populations. We demonstrate that the largest variance in sex ratio is among nearest neighbors. This variance is greatly reduced as the spatial scale of social interactions increases. These patterns suggest the sex of neighbors has the potential to generate fine‐scale differences in selection differentials among individuals. One of the most important determinants of social interactions in plants is the behavior of pollinators. These results suggest that the potential for selection arising from sex ratio will be greatest when pollen is shared among nearest neighbors. Future studies incorporating the movement of pollinators may reveal whether and how this fine‐scale variance in sex ratio affects the fitness of individuals in these populations.Social context refers to the composition of an individual's social interactants, including potential mates. In spatially structured populations, social context can vary among individuals within populations, generating the opportunity for social selection to drive differences in fitness functions among individuals at a fine spatial scale. In sexually polymorphic plants, the local sex ratio varies at a fine scale and thus has the potential to generate this opportunity. We measured the spatial distribution of two wild populations of the gynodioecious plant  The fitness consequences of interacting phenotypes – traits involved in social or sexual interactions – depend on the context in which these interactions occur , the traits of social partners  How do patterns of phenotypic covariance of sex vary among spatial scales; and (2) What do these patterns suggest about the opportunity for social selection in these populations? We demonstrate that the greatest variance in sex ratio among individuals occurs at the smallest spatial scales and that the greatest covariance between the sex of focal individuals and the local sex ratio also occurs at the smallest spatial scales. These patterns suggest that the scale of mating will determine the degree to which selection differentials differ among individuals within the population. Selection differentials will be most strongly impacted by social interactions when pollen is shared among nearest neighbors, and dissipate if mating occurs over larger spatial scales. We discuss these results in terms of their implications for social selection arising from sex ratio and highlight the generality and utility of the social selection framework for the study of plant mating systems and pollination biology.Silene vulgaris (Caryophyllaceae) is a gynodioecious perennial plant that grows predominantly along roadsides in its introduced range in North America  versus aborted anthers . We mapped the spatial positions for all individuals in the two populations through trilateration: Three tripods were spaced evenly around the perimeter of the population, and the GPS coordinates of these tripods were recorded using the Trimble TSC1 survey platform . The measurement of the GPS coordinates for each of these reference points was estimated as accurate to below a distance of one meter. The distance from each plant to each of these three tripods was recorded using the Sonin Multi‐Measure Combo Pro sonic range finder . We used a custom Python trilateration script to convert each of these ordered triplets of distances into GPS coordinates for each individual plant (script available at Dryad http://dx.doi.org/10.5061/dryad.c06n3). All of the following analyses were performed using R version 3.1.1  between all plants for each subpopulation. We then quantified local hermaphrodite frequencies for each individual by tallying the number and sex of neighboring individuals at neighborhood sizes ranging from 0.5 to 6.0 m radii (in 0.5 m steps) from the focal plant. Throughout the following analyses, the hermaphrodite frequency does not include the focal individual, which is the convention in social selection analysis  and the phenotypic variance of local hermaphrodite frequencies (Pjj) across spatial scales using the functions cov and var. We tested whether the Cij′ terms were significantly different from zero using the function cor.test. Finally, we calculated the correlation of the local hermaphrodite frequencies experienced across the different spatial scales and tested the significance of these correlations with the function corr.test in the package psych  and 390 plants in the second population (“Burk2”). The population‐level hermaphrodite frequency of Burk1 was 0.658, and the population‐level hermaphrodite frequency of Burk2 was 0.590. However, there was significant heterogeneity in the distribution of the sexes within each population . Specifically, there was a dramatic contraction of variance in hermaphrodite frequency with increasing spatial scales  also decreased markedly with increasing spatial scale (Fig. The variance in hermaphrodite frequency greatly differed among spatial scales (Brown–Forsythe test, les Fig. . The pheale Fig. .Finally, the correlations between the local hermaphrodite frequencies an individual experienced decreased as the size of the spatial scales diverged Table . The strSilene vulgaris creates the potential for dramatic differences in the social context experienced among individuals, depending on the scale of social interactions. We found that the patterns of phenotypic covariance of sex were greatest at the smallest spatial scales and disappeared at larger scales. These phenotypic covariances will have the greatest potential fitness effects on females, because a positive phenotypic covariance should exacerbate pollen limitation in female plants but not in hermaphrodite plants. This finding is particularly interesting in the context of vector‐pollinated plant populations, because the scale of pollinator movement is often among nearest neighbors (Waser Social selection is generally studied as a population‐level phenomenon. The questions most often asked with regard to social selection are questions of how population‐level characteristics affect the fitness consequences of individual phenotypes. However, when a population exhibits fine‐scale phenotypic structure, there is potential for heterogeneity in local interactions across the population, which can result in different fitness consequences among individuals. Our results demonstrate that the distribution of the sexes in wild populations of rs Waser . This heCij′, a moderate‐to‐high strength of social selection will ameliorate these fitness differences between the sexes. Indeed, the social selection differential would completely counteract the natural selection differential against hermaphrodites when βS ≥ 1.66, such that there would be no difference in fitness between the sexes, despite the strong direct female advantage. Conversely, if pollen moves among plants at scales greater than 3.0 m, the strength of social selection would need to be 10× greater to overcome female advantage, a magnitude that is unlikely to occur.If we make some assumptions about differences in fitness between hermaphrodites and females in these populations, we can use the model of social selection to determine how the patterns of phenotypic covariance we found might impact sex ratio evolution. Although we did not measure fitness in these populations, we can make reasonable estimates based on past work. Previous work suggests females experience a twofold fitness advantage over hermaphrodites in fruit set or seed set (Olson et al. S. vulgaris suggest that the fitness effects of local sex ratios can be substantial. Olson et al. (S. vulgaris and found a negative correlation between fruit set and local female frequency; the relative fitness of females was 19% lower than hermaphrodites due to the fine‐scale spatial structure of the sexes within populations. Our results suggest that this type of social selection has the opportunity to occur simultaneously at several spatial scales within populations. We found that hermaphrodites and females will experience sex ratios biased toward their own sex, provided mating occurs over the scale of a few meters within populations. Thus, the population‐level fitness effects that have previously been demonstrated also are likely to occur among individuals within the population.Previous studies of n et al.  demonstrn et al.  surveyedS. vulgaris, pollination is driven both by diurnal and nocturnal insects (Marsden‐Jones and Turril S. vulgaris hermaphrodites were visited more often and for longer periods of time by diurnal insects, while nocturnal insects showed a less pronounced preference for hermaphrodites. Taken together, these results have several important implications. Moths have been shown to travel greater distances than bees or flies during pollination (Barthelmess et al. In Aralia nudicaulis up to a distance of 40 meters, which they interpreted to reflect extremely long distance pollen dispersal. Aizen (Alstroemeria aurea neither density nor sex ratio explained large amount of variation in pollen receipt among individuals. However, there was a strong effect of sex ratio on seed output, suggesting that pollination effectiveness is impacted by social context. Conversely, there are many examples of species in which there is a direct relationship between fruit and/or seed set and the density of compatible mates in both wind (Stehlik et al. Lobelia cardinalis. Plants experienced negative fitness effects based on the phenotypes of neighbors within 10 centimeters, which the authors interpret as competition for resources, while plants experienced positive fitness effects due to the phenotypes of neighbors at scales greater than 10 centimeters, which they interpret as evidence for facilitation of pollinator visits. These examples highlight how the fitness consequences of social phenotypes can depend on the scale over which interactions occur.Past experiments investigating the scale dependence of the fitness effects of social and ecological context in other plant species have revealed mixed results. Barrett and Thomson  found nol. Aizen  found thS. vulgaris (Dykstra et al. Geranium maculatum (Van Etten and Chang S. vulgaris – the sex ratios of more inbred plants became increasingly female‐biased in a greenhouse crossing study (Glaettli and Goudet The environmental and genetic factors that drive the observed patterns of spatial structure may alter predictions of any short‐ or long‐term responses to social selection. The environment – specifically light and moisture conditions – has been shown to affect sex expression and sex ratio in The interactions that give rise to context‐dependent processes are complex and likely vary among individuals within populations. The scale over which social interactions occur is critical to understanding how social context can affect phenotypic evolution. Whether and how social interactions demonstrate scale dependence is an open question in plants and will vary with aspects of the mating system and ecology of the species. Social selection analysis presents a general empirical framework to investigate such questions and provides standardized metrics that are directly comparable. Although studies of social selection have mostly been conducted in animal species, the approach is equally valid and useful when applied to plant species, especially with respect to competition for resources or sunlight, herbivory, and pollination.http://dx.doi.org/10.5061/dryad.c06n3.Python and R scripts, GPS, and phenotypic data are deposited in Dryad: None declared.Appendix S1. Supplemental methods.Click here for additional data file.