MiR-214-3p regulates Piezo1, lysyl oxidases and mitochondrial function in human cardiac fibroblasts.

Cardiac fibroblasts are pivotal regulators of cardiac homeostasis and are essential in the repair of the heart after myocardial infarction (MI), but their function can also become dysregulated, leading to adverse cardiac remodelling involving both fibrosis and hypertrophy. MicroRNAs (miRNAs) are noncoding RNAs that target mRNAs to prevent their translation, with specific miRNAs showing differential expression and regulation in cardiovascular disease. Here, we show that miR-214-3p is enriched in the fibroblast fraction of the murine heart, and its levels are increased with cardiac remodelling associated with heart failure, or in the acute phase after experimental MI. Tandem mass tagging proteomics and in-silico network analyses were used to explore protein targets regulated by miR-214-3p in cultured human cardiac fibroblasts from multiple donors. Overexpression of miR-214-3p by miRNA mimics resulted in decreased expression and activity of the Piezo1 mechanosensitive cation channel, increased expression of the entire lysyl oxidase (LOX) family of collagen cross-linking enzymes, and decreased expression of an array of mitochondrial proteins, including mitofusin-2 (MFN2), resulting in mitochondrial dysfunction, as measured by citrate synthase and Seahorse mitochondrial respiration assays. Collectively, our data suggest that miR-214-3p is an important regulator of cardiac fibroblast phenotypes and functions key to cardiac remodelling, and that this miRNA represents a potential therapeutic target in cardiovascular disease.

Teachers' emotions in the time of COVID: Thematic analysis of interview data reveals drivers of professional agency.

Purpose: We explored two complex phenomena associated with effective education. First, teachers' professional agency, the volitional actions they take in response to perceived opportunities, was examined to consider individual differences in its enactment. Second, "strong" emotions have been proposed as important in teaching and learning, and we wished to clarify which basic emotions might be involved, besides curiosity, which is a known emotional factor in engagement in teaching. We also explored how agency and basic emotions might be related. Approach: Thirteen teachers working in Scottish secondary schools were interviewed at the start of the covid pandemic in 2020 to discuss relevant feelings, thoughts and actions arising from unprecedented changes in their lives and professional practices. Thematic analysis was used to identify aspects of agentic behavior and basic emotions expressed. Findings: Teacher agency was expressed through adaptability, collective agency, constrained agency, and non-action. Four basic emotion percepts were identified, which we label as "CARE", "CURIOSITY", "COOPERATION", and "CHALLENGE". Originality: We extend the definition of agency to include volitional non-action as a response to opportunity. In contrast to prior research emphasizing emotions as an outcome of volitional behavior, we explore emotions preceding agency. We develop four theoretical propositions related to teacher emotions. (1) Four emotion percepts substantially influence teachers' voluntary motivated behavior. (2) The amount and proportion of emotions experienced varies between individual teachers. (3) The four percepts are experienced concurrently or in rapid succession in engaged teaching contexts. (4) Professional experience and specific situational factors also influence teachers' behavioral choices. For future consideration, we suggest that awareness of emotion percepts may encourage both teachers' engagement and their professional agency for the benefit of their pedagogical practice and outcomes for their students.

Efficacy of interval exercise training to improve vascular health in sedentary postmenopausal females.

BACKGROUND: Menopause represents a turning point where vascular damage begins to outweigh reparative processes, leading to increased cardiovascular disease (CVD) risk. Exercise training reduces CVD risk in postmenopausal females via improvements in traditional risk factors and direct changes to the vasculature. We assessed the effect of moderate (MODERATE-IT) versus heavy (HEAVY-IT) intensity interval exercise training upon markers of cardiovascular health and vascular repair in postmenopausal females. METHODS: Twenty-seven healthy postmenopausal females (56 ± 4 yr) were assigned to 12 weeks of either MODERATE-IT or HEAVY-IT, twice per week. MODERATE-IT consisted of 10s work, and 10s active recovery repeated for 30 min. HEAVY-IT comprised 30s work, and 30s active recovery repeated for 21 ± 2 min. Endothelial function (flow-mediated dilation), arterial stiffness (pulse wave velocity), and V̇O2peak were assessed pre-training and post-training. Blood samples were obtained pre-training and post-training for enumeration of circulating angiogenic cells (CACs), culture of CACs, and lipoprotein profile. RESULTS: V̇O2peak increased 2.4 ± 2.8 ml/kg/min following HEAVY-IT only (p < 0.05). Brachial blood pressure and endothelial function were unchanged with exercise training (p > 0.05). Peripheral pulse wave velocity reduced 8% with exercise training, irrespective of intensity (p < 0.05). Exercise training had no effect on lipoprotein profile or endothelin-1 (p > 0.05). CAC adhesion to vascular smooth muscle cells (VSMC) increased 30 min post plating following MODERATE-IT only (p < 0.05). CONCLUSIONS: HEAVY-IT was more effective at increasing V̇O2peak in postmenopausal females. The ability of CACs to adhere to VSMC improved following MODERATE-IT but not HEAVY-IT. Interval training had the same effect on endothelial function (no change) and arterial stiffness (reduced), regardless of exercise intensity.

Preservation of Smooth Muscle Cell Integrity and Function: A Target for Limiting Abdominal Aortic Aneurysm Expansion?

(1) Abdominal aortic aneurysm (AAA) is a silent, progressive disease with significant mortality from rupture. Whilst screening programmes are now able to detect this pathology early in its development, no therapeutic intervention has yet been identified to halt or retard aortic expansion. The inability to obtain aortic tissue from humans at early stages has created a necessity for laboratory models, yet it is essential to create a timeline of events from EARLY to END stage AAA progression. (2) We used a previously validated ex vivo porcine bioreactor model pre-treated with protease enzyme to create "aneurysm" tissue. Mechanical properties, histological changes in the intact vessel wall, and phenotype/function of vascular smooth muscle cells (SMC) cultured from the same vessels were investigated. (3) The principal finding was significant hyperproliferation of SMC from EARLY stage vessels, but without obvious histological or SMC aberrancies. END stage tissue exhibited histological loss of α-smooth muscle actin and elastin; mechanical impairment; and, in SMC, multiple indications of senescence. (4) Aortic SMC may offer a therapeutic target for intervention, although detailed studies incorporating intervening time points between EARLY and END stage are required. Such investigations may reveal mechanisms of SMC dysfunction in AAA development and hence a therapeutic window during which SMC differentiation could be preserved or reinstated.

Novel Paracrine Action of Endothelium Enhances Glucose Uptake in Muscle and Fat.

[Figure: see text].

Kv1.3 voltage-gated potassium channels link cellular respiration to proliferation through a non-conducting mechanism.

Cellular energy metabolism is fundamental for all biological functions. Cellular proliferation requires extensive metabolic reprogramming and has a high energy demand. The Kv1.3 voltage-gated potassium channel drives cellular proliferation. Kv1.3 channels localise to mitochondria. Using high-resolution respirometry, we show Kv1.3 channels increase oxidative phosphorylation, independently of redox balance, mitochondrial membrane potential or calcium signalling. Kv1.3-induced respiration increased reactive oxygen species production. Reducing reactive oxygen concentrations inhibited Kv1.3-induced proliferation. Selective Kv1.3 mutation identified that channel-induced respiration required an intact voltage sensor and C-terminal ERK1/2 phosphorylation site, but is channel pore independent. We show Kv1.3 channels regulate respiration through a non-conducting mechanism to generate reactive oxygen species which drive proliferation. This study identifies a Kv1.3-mediated mechanism underlying the metabolic regulation of proliferation, which may provide a therapeutic target for diseases characterised by dysfunctional proliferation and cell growth.

Role of MicroRNA-145 in DNA Damage Signalling and Senescence in Vascular Smooth Muscle Cells of Type 2 Diabetic Patients.

Increased cardiovascular morbidity and mortality in individuals with type 2 diabetes (T2DM) is a significant clinical problem. Despite advancements in achieving good glycaemic control, this patient population remains susceptible to macrovascular complications. We previously discovered that vascular smooth muscle cells (SMC) cultured from T2DM patients exhibit persistent phenotypic aberrancies distinct from those of individuals without a diagnosis of T2DM. Notably, persistently elevated expression levels of microRNA-145 co-exist with characteristics consistent with aging, DNA damage and senescence. We hypothesised that increased expression of microRNA-145 plays a functional role in DNA damage signalling and subsequent cellular senescence specifically in SMC cultured from the vasculature of T2DM patients. In this study, markers of DNA damage and senescence were unambiguously and permanently elevated in native T2DM versus non-diabetic (ND)-SMC. Exposure of ND cells to the DNA-damaging agent etoposide inflicted a senescent phenotype, increased expression of apical kinases of the DNA damage pathway and elevated expression levels of microRNA-145. Overexpression of microRNA-145 in ND-SMC revealed evidence of functional links between them; notably increased secretion of senescence-associated cytokines and chronic activation of stress-activated intracellular signalling pathways, particularly the mitogen-activated protein kinase, p38α. Exposure to conditioned media from microRNA-145 overexpressing cells resulted in chronic p38α signalling in naïve cells, evidencing a paracrine induction and reinforcement of cell senescence. We conclude that targeting of microRNA-145 may provide a route to novel interventions to eliminate DNA-damaged and senescent cells in the vasculature and to this end further detailed studies are warranted.

Supporting people who have eating and drinking difficulties.

Eating and drinking are essential for maintenance of nutrition and hydration, but are also important for pleasure and social interactions. The ability to eat and drink hinges on a complex and coordinated system, resulting in significant potential for things to go wrong.The Royal College of Physicians (RCP) has published updated guidance on how to support people who have eating and drinking difficulties, particularly towards the end of life.Decisions about nutrition and hydration and when to start, continue or stop treatment are some of the most challenging to make in medical practice. The newly updated guidance aims to support healthcare professionals to work together with patients, their families and carers to make decisions around nutrition and hydration that are in the best interests of the patient. It covers the factors affecting our ability to eat and drink, strategies to support oral nutrition and hydration, techniques of clinically-assisted nutrition and hydration, and the legal and ethical framework to guide decisions about giving and withholding treatment, emphasising the two key concepts of capacity and best interests.This article aims to provide an executive summary of the guidance.

Vascular Kv7 channels control intracellular Ca2+ dynamics in smooth muscle.

Voltage-gated Kv7 (or KCNQ) channels control activity of excitable cells, including vascular smooth muscle cells (VSMCs), by setting their resting membrane potential and controlling other excitability parameters. Excitation-contraction coupling in muscle cells is mediated by Ca2+ but until now, the exact role of Kv7 channels in cytosolic Ca2+ dynamics in VSMCs has not been fully elucidated. We utilised microfluorimetry to investigate the impact of Kv7 channel activity on intracellular Ca2+ levels and electrical activity of rat A7r5 VSMCs and primary human internal mammary artery (IMA) SMCs. Both, direct (XE991) and G protein coupled receptor mediated (vasopressin, AVP) Kv7 channel inhibition induced robust Ca2+ oscillations, which were significantly reduced in the presence of Kv7 channel activator, retigabine, L-type Ca2+ channel inhibitor, nifedipine, or T-type Ca2+ channel inhibitor, NNC 55-0396, in A7r5 cells. Membrane potential measured using FluoVolt exhibited a slow depolarisation followed by a burst of sharp spikes in response to XE991; spikes were temporally correlated with Ca2+ oscillations. Phospholipase C inhibitor (edelfosine) reduced AVP-induced, but not XE991-induced Ca2+ oscillations. AVP and XE991 induced a large increase of [Ca2+]i in human IMA, which was also attenuated with retigabine, nifedipine and NNC 55-0396. RT-PCR, immunohistochemistry and electrophysiology suggested that Kv7.5 was the predominant Kv7 subunit in both rat and human arterial SMCs; CACNA1C (Cav1.2; L-type) and CACNA1 G (Cav3.1; T-type) were the most abundant voltage-gated Ca2+ channel gene transcripts in both types of VSMCs. This study establishes Kv7 channels as key regulators of Ca2+ signalling in VSMCs with Kv7.5 playing a dominant role.

Divergent effects of genetic and pharmacological inhibition of Nox2 NADPH oxidase on insulin resistance-related vascular damage.

Insulin resistance leads to excessive endothelial cell (EC) superoxide generation and accelerated atherosclerosis. The principal source of superoxide from the insulin-resistant endothelium is the Nox2 isoform of NADPH oxidase. Here we examine the therapeutic potential of Nox2 inhibition on superoxide generation in saphenous vein ECs (SVECs) from patients with advanced atherosclerosis and type 2 diabetes and on vascular function, vascular damage, and lipid deposition in apolipoprotein E-deficient (ApoE-/-) mice with EC-specific insulin resistance (ESMIRO). To examine the effect of genetic inhibition of Nox2, ESMIRO mice deficient in ApoE-/- and Nox2 (ESMIRO/ApoE-/-/Nox2-/y) were generated and compared with ESMIRO/ApoE-/-/Nox2+/y littermates. To examine the effect of pharmacological inhibition of Nox2, we administered gp91dstat or scrambled peptide to ESMIRO/ApoE-/- mice. SVECs from diabetic patients had increased expression of Nox2 protein with concomitant increase in superoxide generation, which could be reduced by the Nox2 inhibitor gp91dstat. After 12 wk Western diet, ESMIRO/ApoE-/-/Nox2-/y mice had reduced EC superoxide generation and greater aortic relaxation to acetylcholine. ESMIRO/ApoE-/-/Nox2-/y mice developed more lipid deposition in the thoraco-abdominal aorta with multiple foci of elastin fragmentation at the level of the aortic sinus and greater expression of intercellular adhesion molecule-1 (ICAM-1). Gp91dstat reduced EC superoxide and lipid deposition in the thoraco-abdominal aorta of ESMIRO/ApoE-/- mice without causing elastin fragmentation or increased ICAM-1 expression. These results demonstrate that insulin resistance is characterized by increased Nox2-derived vascular superoxide. Complete deletion of Nox2 in mice with EC insulin resistance exacerbates, whereas partial pharmacological Nox2 inhibition protects against, insulin resistance-induced vascular damage.

Styrene maleic acid recovers proteins from mammalian cells and tissues while avoiding significant cell death.

Detection of protein biomarkers is an important tool for medical diagnostics, typically exploiting concentration of particular biomarkers or biomarker release from tissues. We sought to establish whether proteins not normally released by living cells can be extracted without harming cells, with a view to extending this into biomarker harvest for medical diagnosis and other applications. Styrene maleic acid (SMA) is a polymer that extracts nanodiscs of biological membranes (containing membrane proteins) from cells. Hitherto it has been used to harvest SMA-lipid-membrane protein particles (SMALP) for biochemical study, by destroying the living cellular specimen. In this study, we applied SMA at low concentration to human primary cardiovascular cells and rat vascular tissue, to 'biopsy' cell proteins while avoiding significant reductions in cell viability. SMA at 6.25 parts per million harvested proteins from cells and tissues without causing significant release of cytosolic dye (calcein) or reduction in cell viability at 24 and 72 hours post-SMA (MTT assay). A wide range of proteins were recovered (20-200 kDa) and a number identified by mass spectrometry: this confirmed protein recovery from plasma membrane, intracellular membranes and cell cytosol without associated cell death. These data demonstrate the feasibility of non-lethally sampling proteins from cells, greatly extending our sampling capability, which could yield new physiological and/or pathological biomarkers.

Mechanically activated Piezo1 channels of cardiac fibroblasts stimulate p38 mitogen-activated protein kinase activity and interleukin-6 secretion.

Piezo1 is a mechanosensitive cation channel with widespread physiological importance; however, its role in the heart is poorly understood. Cardiac fibroblasts help preserve myocardial integrity and play a key role in regulating its repair and remodeling following stress or injury. Here we investigated Piezo1 expression and function in cultured human and mouse cardiac fibroblasts. RT-PCR experiments confirmed that Piezo1 mRNA in cardiac fibroblasts is expressed at levels similar to those in endothelial cells. The results of a Fura-2 intracellular Ca2+ assay validated Piezo1 as a functional ion channel that is activated by its agonist, Yoda1. Yoda1-induced Ca2+ entry was inhibited by Piezo1 blockers (gadolinium and ruthenium red) and was reduced proportionally by siRNA-mediated Piezo1 knockdown or in murine Piezo1+/- cells. Results from cell-attached patch clamp recordings on human cardiac fibroblasts established that they contain mechanically activated ion channels and that their pressure responses are reduced by Piezo1 knockdown. Investigation of Yoda1 effects on selected remodeling genes indicated that Piezo1 activation increases both mRNA levels and protein secretion of IL-6, a pro-hypertrophic and profibrotic cytokine, in a Piezo1-dependent manner. Moreover, Piezo1 knockdown reduced basal IL-6 expression from cells cultured on softer collagen-coated substrates. Multiplex kinase activity profiling combined with kinase inhibitor experiments and phosphospecific immunoblotting established that Piezo1 activation stimulates IL-6 secretion via the p38 mitogen-activated protein kinase downstream of Ca2+ entry. In summary, cardiac fibroblasts express mechanically activated Piezo1 channels coupled to secretion of the paracrine signaling molecule IL-6. Piezo1 may therefore be important in regulating cardiac remodeling.

In-exercise vascular shear rate during acute continuous and interval exercise: impact on endothelial function and miR-21.

Endothelial cell phenotype and endothelial function are regulated by hemodynamic forces, particularly wall shear stress (WSS). During a single bout of exercise, the specific exercise protocol can affect in-exercise WSS patterns and, consequently, endothelial function. MicroRNAs might provide a biomarker of in-exercise WSS pattern to indicate whether a specific exercise bout will have a positive effect on endothelial function. We evaluated the effect of acute interval (IT) and continuous (CON) in-exercise WSS patterns upon postexercise endothelial function and circulating microRNA (miR)-21 expression. Methods and results: 13 participants performed CON and 3 different IT exercise protocols matched for duration and intensity on separate days. Oxygen uptake, heart rate, and brachial artery blood flow were recorded throughout the exercise. Brachial artery flow-mediated dilation (FMD) was performed pre-exercise and 15 min postexercise. Plasma samples were acquired pre-exercise and 6 h postexercise to determine miR-21 expression. In-exercise shear rate (SR) patterns (a surrogate of WSS) differed according to the CON or IT work-rate profile. In-exercise anterograde SR was greater in CON than IT exercise (P < 0.05), but retrograde SR was equivalent between exercise protocols (P > 0.05). Oscillatory shear index was higher during IT versus CON exercise (P < 0.05). Postexercise FMD increased (pre: 7.08% ± 2.95%, post: 10.54% ± 4.24%, P < 0.05), whereas miR-21 expression was unchanged (pre: 12.0% ± 20.7% cel-miR-39, post: 11.1 ± 19.3% cel-miR-39, P > 0.05) with no effect of exercise protocol (P > 0.05). Conclusions: CON and IT exercise induced different SR patterns but equivalent improvements in acute endothelial function. The absence of change in miR-21 expression suggests that miR-21 is not a suitable biomarker of exercise-induced SR.NEW & NOTEWORTHY Interval exercise has the potential to negatively impact vascular adaptations because of repeated oscillations in vascular shear. To our knowledge, we are the first to continuously assess exercise-induced shear throughout different acute exercise protocols and examine its relationship with acute endothelial function and a circulating biomarker of shear (miR-21). These experiments provide clear data indicating enhancement of the acute vascular response from differing interval exercise protocols, with the study also providing detailed vascular and shear responses for future reference.

Fibroblast-specific deletion of interleukin-1 receptor-1 reduces adverse cardiac remodeling following myocardial infarction.

It has been hypothesized that interleukin-1alpha (IL-1α) is released from damaged cardiomyocytes following myocardial infarction (MI) and activates cardiac fibroblasts via its receptor (IL-1R1) to drive the early stages of cardiac remodeling. This study aimed to definitively test this hypothesis using cell type-specific IL-1α and IL-1R1 knockout (KO) mouse models. A floxed Il1α mouse was created and used to generate a cardiomyocyte-specific IL-1α KO mouse line (MIL1AKO). A tamoxifen-inducible fibroblast-specific IL-1R1 hemizygous KO mouse line (FIL1R1KO) was also generated. Mice underwent experimental MI (permanent left anterior descending coronary artery ligation) and cardiac function was determined 4 weeks later by conductance pressure-volume catheter analysis. Molecular markers of remodeling were evaluated at various time points by real-time RT-PCR and histology. MIL1AKO mice showed no difference in cardiac function or molecular markers of remodeling post-MI compared with littermate controls. In contrast, FIL1R1KO mice showed improved cardiac function and reduced remodeling markers post-MI compared with littermate controls. In conclusion, these data highlight a key role for the IL-1R1/cardiac fibroblast signaling axis in regulating post-MI remodeling and provide support for the continued development of anti-IL-1 therapies for improving cardiac function after MI. Cardiomyocyte-derived IL-1α was not an important contributor to post-MI remodeling in this model.

How much rehabilitation are our patients with stroke receiving?

BACKGROUND: Stroke rehabilitation often needs to continue following discharge from hospital. The New Zealand Stroke Network recommends community team review within seven calendar days of discharge and a minimum of three hours of therapy per specialty per week. International stroke guidelines make similar recommendations. The Wellington Community Older Adults, Rehabilitation and Allied Health team aimed to determine current local community stroke rehabilitation practice and compare this to guideline recommendations. METHOD: A prospective cohort of 50 patients with a new diagnosis of stroke, referred to a community rehabilitation team in Wellington, were included in this service audit. The amount of rehabilitation patients received in the first four weeks and first three months following hospital discharge was measured, as well as time to first appointment. In addition, a service satisfaction questionnaire was sent to the patients. RESULTS: The median (interquartile range, IQR) number of days from hospital discharge until first appointment with the community team was 10 (6.3-14.8) calendar days. In the first four weeks after hospital discharge, patients received from all health professionals an average (SD) of 1.1(0.4) rehabilitation sessions and 34.2 (43.6) minutes of rehabilitation per week. The average (SD) in the first three months or to point of discharge, whichever occurred first was 1.1 (1.1) sessions and 42.2 (49.3) minutes of rehabilitation per week. CONCLUSION: There were delays in providing an initial community rehabilitation appointment and insufficient therapy intensity when comparing audit results to New Zealand Guideline expectations. As a result of this audit, recommendations for service improvements have been made.

MicroRNA-21 drives the switch to a synthetic phenotype in human saphenous vein smooth muscle cells.

Cardiovascular disease is a leading cause of morbidity and mortality. Smooth muscle cells (SMC) comprising the vascular wall can switch phenotypes from contractile to synthetic, which can promote the development of aberrant remodelling and intimal hyperplasia (IH). MicroRNA-21 (miR-21) is a short, non-coding RNA that has been implicated in cardiovascular diseases including proliferative vascular disease and ischaemic heart disease. However, its involvement in the complex development of atherosclerosis has yet to be ascertained. Smooth muscle cells (SMC) were isolated from human saphenous veins (SV). miR-21 was over-expressed and the impact of this on morphology, proliferation, gene and protein expression related to synthetic SMC phenotypes monitored. Over-expression of miR-21 increased the spread cell area and proliferative capacity of SV-SMC and expression of MMP-1, whilst reducing RECK protein, indicating a switch to the synthetic phenotype. Furthermore, platelet-derived growth factor BB (PDGF-BB; a growth factor implicated in vasculoproliferative conditions) was able to induce miR-21 expression via the PI3K and ERK signalling pathways. This study has revealed a mechanism whereby PDGF-BB induces expression of miR-21 in SV-SMC, subsequently driving conversion to a synthetic SMC phenotype, propagating the development of IH. Thus, these signaling pathways may be attractive therapeutic targets to minimise progression of the disease. © 2018 IUBMB Life, 70(7):649-657, 2018.

Cardiac fibroblast-specific p38α MAP kinase promotes cardiac hypertrophy via a putative paracrine interleukin-6 signaling mechanism.

Recent studies suggest that cardiac fibroblast-specific p38α MAPK contributes to the development of cardiac hypertrophy, but the underlying mechanism is unknown. Our study used a novel fibroblast-specific, tamoxifen-inducible p38α knockout (KO) mouse line to characterize the role of fibroblast p38α in modulating cardiac hypertrophy, and we elucidated the mechanism. Myocardial injury was induced in tamoxifen-treated Cre-positive p38α KO mice or control littermates via chronic infusion of the ß-adrenergic receptor agonist isoproterenol. Cardiac function was assessed by pressure-volume conductance catheter analysis and was evaluated for cardiac hypertrophy at tissue, cellular, and molecular levels. Isoproterenol infusion in control mice promoted overt cardiac hypertrophy and dysfunction (reduced ejection fraction, increased end systolic volume, increased cardiac weight index, increased cardiomyocyte area, increased fibrosis, and up-regulation of myocyte fetal genes and hypertrophy-associated microRNAs). Fibroblast-specific p38α KO mice exhibited marked protection against myocardial injury, with isoproterenol-induced alterations in cardiac function, histology, and molecular markers all being attenuated. In vitro mechanistic studies determined that cardiac fibroblasts responded to damaged myocardium by secreting several paracrine factors known to induce cardiomyocyte hypertrophy, including IL-6, whose secretion was dependent upon p38α activity. In conclusion, cardiac fibroblast p38α contributes to cardiomyocyte hypertrophy and cardiac dysfunction, potentially via a mechanism involving paracrine fibroblast-to-myocyte IL-6 signaling.-Bageghni, S. A., Hemmings, K. E., Zava, N., Denton, C. P., Porter, K. E., Ainscough, J. F. X., Drinkhill, M. J., Turner, N. A. Cardiac fibroblast-specific p38α MAP kinase promotes cardiac hypertrophy via a putative paracrine interleukin-6 signaling mechanism.

Physicians' views on current legislation around euthanasia and assisted suicide: Results of surveys commissioned by the Royal College of Physicians.

Euthanasia and physician-assisted suicide have always been the subject of intense debate across society. In 2006 and in 2014, the Royal College of Physicians surveyed its members for their opinions on the subject. The results of these surveys are summarised here.

Insulinlike Growth Factor-Binding Protein-1 Improves Vascular Endothelial Repair in Male Mice in the Setting of Insulin Resistance.

Insulin resistance is associated with impaired endothelial regeneration in response to mechanical injury. We recently demonstrated that insulinlike growth factor-binding protein-1 (IGFBP1) ameliorated insulin resistance and increased nitric oxide generation in the endothelium. In this study, we hypothesized that IGFBP1 would improve endothelial regeneration and restore endothelial reparative functions in the setting of insulin resistance. In male mice heterozygous for deletion of insulin receptors, endothelial regeneration after femoral artery wire injury was enhanced by transgenic expression of human IGFBP1 (hIGFBP1). This was not explained by altered abundance of circulating myeloid angiogenic cells. Incubation of human endothelial cells with hIGFBP1 increased integrin expression and enhanced their ability to adhere to and repopulate denuded human saphenous vein ex vivo. In vitro, induction of insulin resistance by tumor necrosis factor α (TNFα) significantly inhibited endothelial cell migration and proliferation. Coincubation with hIGFBP1 restored endothelial migratory and proliferative capacity. At the molecular level, hIGFBP1 induced phosphorylation of focal adhesion kinase, activated RhoA and modulated TNFα-induced actin fiber anisotropy. Collectively, the effects of hIGFBP1 on endothelial cell responses and acceleration of endothelial regeneration in mice indicate that manipulating IGFBP1 could be exploited as a putative strategy to improve endothelial repair in the setting of insulin resistance.

Progressive Development of Aberrant Smooth Muscle Cell Phenotype in Abdominal Aortic Aneurysm Disease.

Abdominal aortic aneurysm (AAA) is a silent, progressive disease with a high mortality and an increasing prevalence with aging. Smooth muscle cell (SMC) dysfunction contributes to gradual dilatation and eventual rupture of the aorta. Here we studied phenotypic characteristics in SMC cultured from end-stage human AAA (≥5 cm) and cells cultured from a porcine carotid artery (PCA) model of early and end-stage aneurysm. Human AAA-SMC presented a secretory phenotype and expressed elevated levels of the differentiation marker miR-145 (2.2-fold, p < 0.001) and the senescence marker SIRT-1 (1.3-fold, p < 0.05), features not recapitulated in aneurysmal PCA-SMC. Human and end-stage porcine aneurysmal cells were frequently multi-nucleated (3.9-fold, p < 0.001, and 1.8-fold, p < 0.01, respectively, vs. control cells) and displayed an aberrant nuclear morphology. Human AAA-SMC exhibited higher levels of the DNA damage marker γH2AX (3.9-fold, p < 0.01, vs. control SMC). These features did not correlate with patients' chronological age and are therefore potential markers for pathological premature vascular aging. Early-stage PCA-SMC (control and aneurysmal) were indistinguishable from one another across all parameters. The principal limitation of human studies is tissue availability only at the end stage of the disease. Refinement of a porcine bioreactor model would facilitate the study of temporal modulation of SMC behaviour during aneurysm development and potentially identify therapeutic targets to limit AAA progression.