Spinal muscular atrophy (SMA) is a genetic disorder caused by reduced levels of the survival motor neuron (SMN) protein. The primary pathology involves the loss of motor neurons, however extra-neuronal tissues, including the heart, are also affected. The mechanisms underlying cardiac dysfunction in SMA are poorly understood, with some evidence suggesting impaired sympathetic innervation in vivo. To investigate the origins of cardiac dysfunction, we assessed the cardiac adrenergic response using an SMNΔ7 mouse model of SMA and cardiomyocytes derived from SMA patient induced pluripotent stem cells. The β adrenergic agonist, isoproterenol, failed to increase the amplitude of the Ca2+ transient or the heart rate. Adrenergic insensitivity was associated with a chronic activation of the cAMP-PKA signaling pathway downstream of the β adrenergic receptor. Basal cAMP levels and PKA activity were significantly elevated and PDE activity was reduced in SMN-deficient cardiac tissues. Collectively, these findings suggest a novel molecular mechanism for cardiac dysfunction in SMA that renders the heart insensitive to adrenergic stimulation and identifies the PDE pathway as a potential therapeutic target to ameliorate cardiac deficits in SMA.

Spinal muscular atrophy (SMA) is an inherited neurodegenerative disease that leads to loss of motor neurons in the anterior horn of the spinal cord with consequent muscle atrophy. SMA results from the functional deletions of the SMN1 gene, resulting in insufficient production of the survival motor neuron (SMN) protein. It is not known why lower motor neurons are particularly sensitive to the loss of SMN function, but it is increasingly apparent that extraneuronal tissues, such as cardiac and skeletal muscle, are also affected by SMN deficiency. We have previously shown that SMN deficiency in a mouse model of spinal muscular atrophy (SMNΔ7) impairs cardiomyocyte contraction and Ca2+ handling. In this study, we performed a comparative total mRNA sequencing analysis of whole hearts isolated at an early (P5) or late (P10) stage of the disease process to investigate the mechanisms contributing to cardiac pathology in SMA. The results demonstrate transcriptional signatures consistent with heart failure, dysregulation of Ca2+ signaling, and hypoxia induced changes occurring as early as P5 and persisting through P10. Similar transcriptomic changes in skeletal muscle tissue indicate that there are likely common, cell autonomous molecular mechanisms resulting in both cardiac and skeletal muscle due to SMN deficiency. The identification of these common themes suggests a link underlying the mechanism of neuronal and non-neuronal deficits in SMA.

Supplementary Figure 4 - PDF file 314K, Changes in mean heart rate during cycles 1 when patients taking betablockers were excluded

Supplementary Figure 5 - PDF file 60K, Changes in heart rate observed for patients in the NIH cohort during cycle 2 days 1, 8 and 15

Supplementary Figure Legends - PDF file 25K, Legends describing supplementary figures

Supplementary Figure 6 - PDF file 60K, Changes in heart rate observed for each patient in the NIH cohort during cycle 2 days 1, 8 and 15, excluding the patients taking beta-blockers

Supplementary Figure 7 - PDF file 317K, Changes in mean heart rate occurring during cycle 1 days 1, 8 and 15 grouped by baseline heart rate

The coordination of cellular biological processes is regulated in part via metabolic enzymes acting to match cellular metabolism to current conditions. The acetate activating enzyme, acyl-coenzyme A synthetase short-chain family member 2 (Acss2), has long been considered to have a predominantly lipogenic function. More recent evidence suggests that this enzyme has regulatory functions in addition to its role in providing acetyl-CoA for lipid synthesis. We used Acss2 knockout mice (Acss2−/−) to further investigate the roles this enzyme plays in three physiologically distinct organ systems that make extensive use of lipid synthesis and storage, including the liver, brain, and adipose tissue. We examined the resulting transcriptomic changes resulting from Acss2 deletion and assessed these changes in relation to fatty acid constitution. We find that loss of Acss2 leads to dysregulation of numerous canonical signaling pathways, upstream transcriptional regulatory molecules, cellular processes, and biological functions, which were distinct in the liver, brain, and mesenteric adipose tissues. The detected organ-specific transcriptional regulatory patterns reflect the complementary functional roles of these organ systems within the context of systemic physiology. While alterations in transcriptional states were evident, the loss of Acss2 resulted in few changes in fatty acid constitution in all three organ systems. Overall, we demonstrate that Acss2 loss institutes organ-specific transcriptional regulatory patterns reflecting the complementary functional roles of these organ systems. Collectively, these findings provide further confirmation that Acss2 regulates key transcription factors and pathways under well-fed, non-stressed conditions and acts as a transcriptional regulatory enzyme.

Supplementary Figure 1 - PDF file 69K, Changes in heart rate observed for patients in the NIH cohort during cycle 1 days 1, 8 and 15

Supplementary Figure 3 - PDF file 62K, Changes in mean heart rate during cycles 1 when patients taking betablockers were excluded

Supplementary Figure 8 - PDF file 299K, Changes in mean heart rate during cycles 2 when patients taking betablockers were excluded

Optimal nutrition is imperative for psychological health. Oxidative stress and inflammation are underlying etiologies for alterations in psychological health. Warfighters are at risk of health concerns such as depression due to increased stress in austere environments and family separation while deployed. Over the last decade, research has demonstrated the health benefits of flavonoids found in fruits and berries. Berry flavonoids have potent antioxidant and anti-inflammatory properties by inhibiting oxidative stress and inflammation. In this review, the promising effects of various berries rich in bioactive flavonoids are examined. By inhibiting oxidative stress, berry flavonoids have the potential to modulate brain, cardiovascular, and intestinal health. There is a critical need for targeted interventions to address psychological health concerns within the warfighter population, and a berry flavonoid-rich diet and/or berry flavonoid dietary supplement intervention may prove beneficial as an adjunctive therapy. Structured searches of the literature were performed in the PubMed, CINAHL, and EMBASE databases using predetermined keywords. This review focuses on berry flavonoids' critical and fundamental bioactive properties and their potential effects on psychological health in investigations utilizing cell, animal, and human model systems.

Supplementary Figure 2 - PDF file 260K, Changes in mean heart rate occurring during cycle 1 days 1, 8 and 15 grouped by baseline heart rate

Supplemental Tables - PDF file 76K, Table S1. Diplotype arrangements of the ABCB1 SNPs calculated using Haploview. (Reproduced with authors' permission, Sissung et al, 2011(13); Table S2. Analysis of reported cardiovascular events for all 131 patients in NCI 1312; Table S3. Statistical Analyzes of Albumin, Potassium & Magnesium Data; Table S4. Analysis of variance to examine the relationship between albumin, potassium and magnesium levels in patients treated on NCI 1312; table legends

Oxidative stress is a key underlying factor in cognitive decline and atherosclerosis. Oxidative stress occurs at the cellular level with an imbalance between reactive oxygen species and reactive nitrogen species and a deficiency in antioxidants. Mounting evidence suggests that berry flavonoids may promote cellular health by exerting antioxidant properties. Black currant and various berry extracts were tested in microglia (BV-2) and cardiomyocyte (HL-1) cell lines to study their biological effects. The principal ingredients in black currant and cranberry extract–delphinidin 3-rutinoside (D3R) and cyanidin 3-glucoside (C3G), were also assessed. A menadione-induced oxidative stressor was used, and its output was quantified to detect oxidative stress (CellROXTM). Black currant extract had similar antioxidant effects as N-acetylcysteine (NAC) in HL-1 cells with regard to cellular protection, whereas cranberry extract was ineffective. In contrast, cranberry extract was comparable in effectiveness to black currant extract in BV-2 cells. D3R and C3G also reduced oxidative stress similarly to whole berry extracts, which indicates that these ingredients may confer the antioxidant effects of berries. Black currant and cranberry extracts inhibit oxidative stress in microglial and cardiomyocyte cell lines. Black currant extract was more effective in reducing oxidative stress in the HL-1 cells, whereas cranberry extract was comparable in reducing oxidative stress in the BV-2 cells. The results suggest that berry flavonoids exert neuro- and cardioprotective effects.

Background: Cardiovascular disease (CVD) affects a large sector of the U.S. population; accounting for millions of adult men and women impacted by its high annual incidence of mortality and morbidity. An underlying cellular link to the pathophysiological process of CVD is oxidative stress. Oxidative stress occurs when there is an imbalance of reactive oxygen species, reactive nitrogen species, and a deficiency in antioxidants. In particular, flavonoids found in fruits and berries have antioxidant properties that may quell oxidative stress activities at the cellular level. Mounting evidence suggests that flavonoids in the form of berry extracts may offer health benefits. Methods: Blackcurrant and various berry extracts (aronia berry, tart cherry, elderberry, cranberry, and a berry blend) were investigated in cultured cardiomyocyte (HL-1) cell line-to determine their effects on oxidative stress. Cells were maintained in Claycomb medium at 37°C in humidified 5% humidified CO 2. A menadione-induced oxidative stressor was applied to generate oxidative stress in the HL-1 cells. A CellROX TM green reagent assay was used as a detection method of oxidative stress. The effects of berry extracts on cell viability within the HL-1 cells were also investigated. Results: Blackcurrant extract was found to be superior compared to all of the other berry extracts in suppressing oxidative stress in the HL-1 cells. N-acetyl-cysteine (NAC) used as a control, also had similar antioxidant effects as blackcurrant extract in the HL-1 cells under menadione-induced oxidative stress conditions. Additionally, NAC demonstrated significance for increased cell viability and cardio protection, while blackcurrant extract showed modest cellular protection. These results indicate that blackcurrant extract has potent antioxidant and modest cardioprotective properties comparable to NAC in HL-1 cells. Conclusion: Blackcurrant extract rich in flavonoids showed promising effects as an antioxidant with cardioprotective benefits. This may have significant implications for improving CV health in the human model. Further studies are warranted to determine the role of the bioactive components of blackcurrant and application to CV health.

Background Methadone is associated with a disproportionate risk of sudden death and ventricular tachyarrhythmia despite only modest inhibition of delayed rectifier K+ current (I Kr), the principal mechanism of drug‐associated arrhythmia. Congenital defects of inward rectifier K+ current (I K1) have been linked to increased U‐wave amplitude on ECG and fatal arrhythmia. We hypothesized that methadone may also be a potent inhibitor of I K1, contributing to delayed repolarization and manifesting on surface ECGs as augmented U‐wave integrals. Methods and Results Using a whole‐cell voltage clamp, methadone inhibited both recombinant and native I K1 with a half‐maximal inhibitory concentration IC50) of 1.5 μmol/L, similar to that observed for I Kr block (half‐maximal inhibitory concentration of 2.9 μmol/L). Methadone modestly increased the action potential duration at 90% repolarization and slowed terminal repolarization at low concentrations. At higher concentrations, action potential duration at 90% repolarization lengthening was abolished, but its effect on terminal repolarization rose steadily and correlated with increased fluctuations of diastolic membrane potential. In parallel, patient ECGs were analyzed before and after methadone initiation, with 68% of patients having a markedly increased U‐wave integral compared with premethadone (lead V3; mean +38%±15%, P=0.016), along with increased QT and TPeak to TEnd intervals, likely reflective of I Kr block. Conclusions Methadone is a potent I K1 inhibitor that causes augmentation of U waves on surface ECG. We propose that increased membrane instability resulting from I K1 block may better explain methadone’s arrhythmia risk beyond I Kr inhibition alone. Drug‐induced augmentation of U waves may represent evidence of blockade of multiple repolarizing ion channels, and evaluation of the effect of that agent on I K1 may be warranted.

Neither I nor my family members have a financial interest in any commercial product, service, or organization providing financial support for this research.

We recently discovered that the histone deacetylase inhibitor, trichostatin A (TSA), increases expression of the sulfonylurea receptor 2 (SUR2; Abcc9) subunit of the ATP-sensitive K+ (KATP) channel in HL-1 cardiomyocytes. Interestingly, the increase in SUR2 was abolished with exogenous cholesterol, suggesting that cholesterol may regulate channel expression. In the present study, we tested the hypothesis that TSA increases SUR2 by depleting cholesterol and activating the sterol response element binding protein (SREBP) family of transcription factors. Treatment of HL-1 cardiomyocytes with TSA (30 ng/ml) caused a time-dependent increase in SUR2 mRNA expression that correlates with the time course of cholesterol depletion assessed by filipin staining. Consistent with the cholesterol-dependent regulation of SREBP increasing SUR2 mRNA expression, we observe a significant increase in SREBP cleavage and translocation to the nucleus following TSA treatment that is inhibited by exogenous cholesterol. Further supporting the role of SREBP in mediating the effect of TSA on KATP subunit expression, SREBP1 significantly increased luciferase reporter gene expression driven by the upstream SUR2 promoter. Lastly, HL-1 cardiomyocytes treated with the SREBP inhibitor PF429242 significantly suppresses the effect of TSA on SUR2 gene expression. These results demonstrate that SREBP is an important regulator of KATP channel expression and suggest a novel method by which hypercholesterolemia may exert negative effects on the cardiovascular system, namely, by suppressing expression of the KATP channel.