Rationale: Physical exercise provides benefits for various organ systems, and some of systemic effects of exercise are mediated through modulation of muscle-derived secreted factors, also known as myokines. Myonectin/C1q (complement component 1q)/TNF (tumor necrosis factor)-related protein 15/erythroferrone is a myokine that is upregulated in skeletal muscle and blood by exercise. Objective: We investigated the role of myonectin in myocardial ischemic injury. Methods and Results: Ischemia-reperfusion in myonectin-knockout mice led to enhancement of myocardial infarct size, cardiac dysfunction, apoptosis, and proinflammatory gene expression compared with wild-type mice. Conversely, transgenic overexpression of myonectin in skeletal muscle reduced myocardial damage after ischemia-reperfusion. Treadmill exercise increased circulating myonectin levels in wild-type mice, and it reduced infarct size after ischemia-reperfusion in wild-type mice, but not in myonectin-knockout mice. Treatment of cultured cardiomyocytes with myonectin protein attenuated hypoxia/reoxygenation-induced apoptosis via S1P (sphingosine-1-phosphate)-dependent activation of cAMP/Akt cascades. Similarly, myonectin suppressed inflammatory response to lipopolysaccharide in cultured macrophages through the S1P/cAMP/Akt-dependent signaling pathway. Moreover, blockade of S1P-dependent pathway reversed myonectin-mediated reduction of myocardial infarct size in mice after ischemia-reperfusion. Conclusions: These data indicate that myonectin functions as an endurance exercise-induced myokine which ameliorates acute myocardial ischemic injury by suppressing apoptosis and inflammation in the heart, suggesting that myonectin mediates some of the beneficial actions of exercise on cardiovascular health.

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Obesity is closely associated with the progression of vascular disorders, including atherosclerosis and postangioplasty restenosis. C1q/TNF-related protein (CTRP) 9 is an adipocytokine that is down-regulated in obese mice. Here we investigated whether CTRP9 modulates neointimal hyperplasia and vascular smooth muscle cell (VSMC) proliferation in vivo and in vitro. Left femoral arteries of wild-type (WT) mice were injured by a steel wire. An adenoviral vector expressing CTRP9 (Ad-CTRP9) or β-galactosidase as a control was intravenously injected into WT mice 3 d before vascular injury. Delivery of Ad-CTRP9 significantly attenuated the neointimal thickening and the number of bromodeoxyuridine-positive proliferating cells in the injured arteries compared with that of control. Treatment of VSMCs with CTRP9 protein attenuated the proliferative and chemotactic activities induced by growth factors including platelet-derived growth factor (PDGF)-BB, and suppressed PDGF-BB-stimulated phosphorylation of ERK. CTRP9 treatment dose-dependently increased cAMP levels in VSMCs. Blockade of cAMP-PKA pathway reversed the inhibitory effect of CTRP9 on DNA synthesis and ERK phosphorylation in response to PDGF-BB. The present data indicate that CTRP9 functions to attenuate neointimal formation following vascular injury through its ability to inhibit VSMC growth via cAMP-dependent mechanism, suggesting that the therapeutic approaches to enhance CTRP9 production could be valuable for prevention of vascular restenosis after angioplasty.

Our findings indicate that muscle-derived Fstl1 attenuates neointimal formation in response to arterial injury by suppressing SMC proliferation through an AMPK-dependent mechanism. Thus, the release of protein factors from muscle, such as Fstl1, may partly explain why the maintenance of muscle function can have a therapeutic effect on the cardiovascular system.

Heart disease contributes to the progression of CKD. Heart tissue produces a number of secreted proteins, also known as cardiokines, which participate in intercellular and intertissue communication. We recently reported that follistatin-like 1 (Fstl1) functions as a cardiokine with cardioprotective properties. Here, we investigated the role of cardiac Fstl1 in renal injury after subtotal nephrectomy. Cardiac-specific Fstl1-deficient (cFstl1-KO) mice and wild-type mice were subjected to subtotal (5/6) nephrectomy. cFstl1-KO mice showed exacerbation of urinary albumin excretion, glomerular hypertrophy, and tubulointerstitial fibrosis after subtotal renal ablation compared with wild-type mice. cFstl1-KO mice also exhibited increased mRNA levels of proinflammatory cytokines, including TNF-a and IL-6, NADPH oxidase components, and fibrotic mediators, in the remnant kidney. Conversely, systemic administration of adenoviral vectors expressing Fstl1 (Ad-Fstl1) to wild-type mice with subtotal nephrectomy led to amelioration of albuminuria, glomerular hypertrophy, and tubulointerstitial fibrosis, accompanied by reduced expression of proinflammatory mediators, NADPH oxidase components, and fibrotic markers in the remnant kidney. In cultured human mesangial cells, treatment with recombinant FSTL1 attenuated TNF-a-stimulated expression of proinflammatory cytokines. Treatment of mesangial cells with FSTL1 augmented the phosphorylation of AMP-activated protein kinase (AMPK), and inhibition of AMPK activation abrogated the anti-inflammatory effects of FSTL1. These data suggest that Fstl1 functions in cardiorenal communication and that the lack of Fstl1 production by myocytes promotes glomerular and tubulointerstitial damage in the kidney.

Background: Tissue ischemia stimulates production of secreted factors that regulate angiogenesis. Results: Neuron-derived neurotrophic factor (NDNF) is up-regulated in endothelial cells in ischemic limbs of mice. NDNF stimulates endothelial cell function and promotes ischemia-induced revascularization through NOS-dependent mechanisms. Conclusion: NDNF functions as a novel modulator that stimulates revascularization processes. Significance: NDNF represents a novel therapeutic target for ischemic vascular diseases.

Obesity is highly linked with the development of vascular diseases. Omentin is a circulating adipokine that is downregulated in patients with cardiovascular diseases. In this study, we investigated the role of omentin in regulation of vascular remodeling in response to injury. Wild-type (WT) mice were treated intravenously with adenoviral vectors encoding human omentin (Ad-OMT) or control b-gal and subjected to arterial wire injury. Ad-OMT treatment reduced the neointimal thickening and the frequencies of bromodeoxyuridine-positive proliferating cells in injured arteries. Treatment of vascular smooth muscle cells (VSMCs) with human omentin protein at a physiologic concentration led to suppression of growth and ERK phosphorylation after stimulation with various growth factors. Omentin stimulated AMPK signaling in VSMCs, and blockade of AMPK reversed omentinmediated inhibition of VSMC growth and ERK phosphorylation. Furthermore, fat-specific human omentin transgenic (OMT-TG) mice exhibited reduced neointimal thickening and vascular cell growth following vascular injury. AMPK activation was enhanced in injured arteries in OMT-TG mice, and administration of AMPK inhibitor reversed the reduction of neointimal hyperplasia in OMT-TG mice. These data indicate that omentin attenuates neointimal formation after arterial injury and suppresses VSMC growth through AMPKdependent mechanisms. Thus, omentin can represent a novel target molecule for the prevention of vascular

Objective Red blood cell distribution width (RDW) is a numerical measure of erythrocyte size variation. It has been recently reported to be an independent prognostic marker of heart failure (HF). Previous studies on RDW were mostly designed for middle-aged and elderly patients (60-79 years old), therefore, there is no established limit for super-elderly patients (! 80 years old). The purpose of this study was to evaluate RDW as an effective tool to detect fatal HF in super-elderly patients. Methods The medical records and death certificates of 160 consecutive patients admitted to the Department of Cardiology in Juntendo Tokyo Koto Geriatric Medical Center and who died from June 2002 to October 2010 were reviewed. The causes of death were reviewed, and the factors, including RDW, that might have been related to the fatal HF were evaluated using multivariate logistic regression analysis. Results HF was the major cause of death [52 patients (32.5%), 29 females, age 84.0±7.5 years], followed by pneumonia (18.8%, 30/160), and acute myocardial infarction (16.3%, 26/160). The most common cause of HF was atrial fibrillation (36.6%, 19/52), followed by hypertensive heart disease (19.2%, 10/52) and valvular disorders (17.3%, 9/52). The multivariate logistic regression analysis found that a high RDW (! 16.5%) was an independent factor related to fatal HF (OR 2.36, 95% CI 1.10, 5.04, p=0.03). Conclusion HF was the major cause of death, and RDW ! 16.5 was significantly associated with fatal HF in super-elderly patients.