C ytokines/chemokines and growth factors regulate pulmonary endothelial function and influence the development of pulmonary arterial hypertension (PAH).1 PAH is characterized by pulmonary vascular remodeling and perivascular inflammation, leading to right ventricular (RV) failure and premature death. [2][3][4][5] Endothelial dysfunction is a crucial pathogenic status that triggers a variety of vascular disorders, such as PAH. 6,7 Endothelial dysfunction is also considered a key underlying feature in most forms of clinical and experimental PAH, which is enhanced by inflammatory cytokines/ chemokines and growth factors.1,8 Indeed, we experience rapid progression and worsening of PAH, especially when complicated with infectious diseases, such as pneumonia and catheter-related infection.8 Pulmonary endothelial dysfunction in patients with PAH enhances pulmonary vascular remodeling through impaired release of vasodilators, such as nitric oxide (NO) and prostacyclin. [9][10][11] AMP-activated protein kinase (AMPK) is a heterotrimeric complex consisting of a catalytic subunit α and 2 regulatory subunits β and γ, and it is expressed in various tissues and Molecular Medicine© 2016 American Heart Association, Inc. ). In contrast, development of hypoxia-induced PH was accelerated in eAMPK -/-mice compared with controls. Furthermore, the exacerbation of PH in eAMPK -/-mice was accompanied by reduced endothelial function, upregulation of growth factors, and increased proliferation of pulmonary artery smooth muscle cells. Importantly, conditioned medium from endothelial cells promoted pulmonary artery smooth muscle cell proliferation, which was further enhanced by the treatment with AMPK inhibitor. Serum levels of inflammatory cytokines, including tumor necrosis factor-α and interferon-γ were significantly increased in patients with PAH compared with healthy controls. Consistently, endothelial AMPK and cell proliferation were significantly reduced by the treatment with serum from patients with PAH compared with controls. Importantly, long-term treatment with metformin, an AMPK activator, significantly attenuated hypoxiainduced PH in mice. Conclusions:

These results indicate that SeP promotes the development of PH, suggesting that it is a novel biomarker and therapeutic target of the disorder.

Rationale: Pulmonary arterial hypertension (PAH) is characterized by pulmonary vascular remodeling with aberrant pulmonary artery smooth muscle cells (PASMCs) proliferation, endothelial dysfunction, and extracellular matrix remodeling. Objective: Right ventricular (RV) failure is an important prognostic factor in PAH. Thus, we need to elucidate a novel therapeutic target in both PAH and RV failure. Methods and Results: We performed microarray analysis in PASMCs from patients with PAH (PAH-PASMCs) and controls. We found a ADAMTS8 (disintegrin and metalloproteinase with thrombospondin motifs 8), a secreted protein specifically expressed in the lung and the heart, was upregulated in PAH-PASMCs and the lung in hypoxia-induced pulmonary hypertension (PH) in mice. To elucidate the role of ADAMTS8 in PH, we used vascular smooth muscle cell-specific ADAMTS8-knockout mice (ADAMTS ΔSM22 ). Hypoxia-induced PH was attenuated in ADAMTS ΔSM22 mice compared with controls. ADAMTS8 overexpression increased PASMC proliferation with downregulation of AMPK (AMP-activated protein kinase). In contrast, deletion of ADAMTS8 reduced PASMC proliferation with AMPK upregulation. Moreover, deletion of ADAMTS8 reduced mitochondrial fragmentation under hypoxia in vivo and in vitro. Indeed, PASMCs harvested from ADAMTS ΔSM22 mice demonstrated that phosphorylated DRP-1 (dynamin-related protein 1) at Ser637 was significantly upregulated with higher expression of profusion genes (Mfn1 and Mfn2) and improved mitochondrial function. Moreover, recombinant ADAMTS8 induced endothelial dysfunction and matrix metalloproteinase activation in an autocrine/paracrine manner. Next, to elucidate the role of ADAMTS8 in RV function, we developed a cardiomyocyte-specific ADAMTS8 knockout mice (ADAMTS8 ΔαMHC ). ADAMTS8 ΔαMHC mice showed ameliorated RV failure in response to chronic hypoxia. In addition, ADAMTS8 ΔαMHC mice showed enhanced angiogenesis and reduced RV ischemia and fibrosis. Finally, high-throughput screening revealed that mebendazole, which is used for treatment of parasite infections, reduced ADAMTS8 expression and cell proliferation in PAH-PASMCs and ameliorated PH and RV failure in PH rodent models. Conclusions: These results indicate that ADAMTS8 is a novel therapeutic target in PAH.

Although postcapillary pulmonary hypertension (PH) is an important prognostic factor for patients with heart failure (HF), its pathogenesis remains to be fully elucidated. To elucidate the different roles of Rho-kinase isoforms, ROCK1 and ROCK2, in cardiomyocytes in response to chronic pressure overload, we performed transverse aortic constriction (TAC) in cardiac-specific ROCK1-deficient () and ROCK2-deficient () mice. Cardiomyocyte-specific ROCK1 deficiency promoted pressure-overload-induced cardiac dysfunction and postcapillary PH, whereas cardiomyocyte-specific ROCK2 deficiency showed opposite results. Histological analysis showed that pressure-overload-induced cardiac hypertrophy and fibrosis were enhanced in mice compared with controls, whereas cardiac hypertrophy was attenuated in mice after TAC. Consistently, the levels of oxidative stress were up-regulated in hearts and down-regulated in hearts compared with controls after TAC. Furthermore, cyclophilin A (CyPA) and basigin (Bsg), both of which augment oxidative stress, enhanced cardiac dysfunction and postcapillary PH in mice, whereas their expressions were significantly lower in mice. In clinical studies, plasma levels of CyPA were significantly increased in HF patients and were higher in patients with postcapillary PH compared with those without it. Finally, high-throughput screening demonstrated that celastrol, an antioxidant and antiinflammatory agent, reduced the expressions of CyPA and Bsg in the heart and the lung, ameliorating cardiac dysfunction and postcapillary PH induced by TAC. Thus, by differentially affecting CyPA and Bsg expressions, ROCK1 protects and ROCK2 jeopardizes the heart from pressure-overload HF with postcapillary PH, for which celastrol may be a promising agent.

-Thoracic aortic aneurysm (TAA) and dissection (TAD) are fatal diseases, which cause aortic rupture and sudden death. The small GTP-binding protein GDP dissociation stimulator (SmgGDS) is a crucial mediator of the pleiotropic effects of statins. Previous studies revealed that reduced force generation in AoSMCs causes TAA and TAD. -To examine the role of SmgGDS in TAA formation, we employed an angiotensin II (AngII, 1,000 ng/min/kg, 4 weeks)-induced TAA model. -33% mice died suddenly due to TAA rupture, whereas there was no TAA rupture in control mice. In contrast, there was no significant difference in the ratio of abdominal aortic aneurysm rupture between the two genotypes. We performed ultrasound imaging every week to follow the serial changes in aortic diameters. The diameter of the ascending aorta progressively increased in mice compared with mice, whereas that of the abdominal aorta remained comparable between the two genotypes. Histological analysis of mice showed dissections of major thoracic aorta in the early phase of AngII infusion (day 3~5) and more severe elastin degradation compared with mice. Mechanistically, mice showed significantly higher levels of oxidative stress, matrix metalloproteinases, and inflammatory cell migration in the ascending aorta compared with mice. For mechanistic analyses, we primary cultured aortic smooth muscle cells (AoSMCs) from the 2 genotypes. After AngII (100 nM) treatment for 24 hours, AoSMCs showed significantly increased MMP activity and oxidative stress levels compared with AoSMCs. In addition, SmgGDS deficiency increased cytokines/chemokines and growth factors in AoSMCs. Moreover, expressions of and, which are force generation genes, were significantly reduced in AoSMCs compared with AoSMCs. Similar tendency was noted in AoSMCs from TAA patients compared with those from controls. Finally, local delivery of the SmgGDS gene construct reversed the dilation of the ascending aorta in mice. -These results suggest that SmgGDS is a novel therapeutic target for the prevention and treatment of TAA.

Objective— Basigin (Bsg) is a transmembrane glycoprotein that activates matrix metalloproteinases and promotes inflammation. However, the role of Bsg in the pathogenesis of cardiac hypertrophy and failure remains to be elucidated. We examined the role of Bsg in cardiac hypertrophy and failure in mice and humans. Approach and Results— We performed transverse aortic constriction in Bsg +/– and in wild-type mice. Bsg +/– mice showed significantly less heart and lung weight and cardiac interstitial fibrosis compared with littermate controls after transverse aortic constriction. Both matrix metalloproteinase activities and oxidative stress in loaded left ventricle were significantly less in Bsg +/– mice compared with controls. Echocardiography showed that Bsg +/– mice showed less hypertrophy, less left ventricular dilatation, and preserved left ventricular fractional shortening compared with littermate controls after transverse aortic constriction. Consistently, Bsg +/– mice showed a significantly improved long-term survival after transverse aortic constriction compared with Bsg +/+ mice, regardless of the source of bone marrow ( Bsg +/+ or Bsg +/– ). Conversely, cardiac-specific Bsg-overexpressing mice showed significantly poor survival compared with littermate controls. Next, we isolated cardiac fibroblasts and examined their responses to angiotensin II or mechanical stretch. Both stimuli significantly increased Bsg expression, cytokines/chemokines secretion, and extracellular signal–regulated kinase/Akt/JNK activities in Bsg +/+ cardiac fibroblasts, all of which were significantly less in Bsg +/– cardiac fibroblasts. Consistently, extracellular and intracellular Bsg significantly promoted cardiac fibroblast proliferation. Finally, serum levels of Bsg were significantly elevated in patients with heart failure and predicted poor prognosis. Conclusions— These results indicate the crucial roles of intracellular and extracellular Bsg in the pathogenesis of cardiac hypertrophy, fibrosis, and failure in mice and humans.

The results indicate that plasma CyPA levels can be used to predict all-cause death, rehospitalization, and coronary revascularization in patients with coronary artery disease and that when combined with other biomarkers (hsCRP and brain natriuretic peptide levels), the CyPA levels have further enhanced prognostic impacts in those patients.

BackgroundCirculating proteins are exposed to vascular endothelial layer and influence their functions. Among them, adipsin is a member of the trypsin family of peptidases and is mainly secreted from adipocytes, monocytes, and macrophages, catalyzing the rate‐limiting step of the alternative complement pathway. However, its pathophysiological role in cardiovascular disease remains to be elucidated. Here, we examined whether serum adipsin levels have a prognostic impact in patients with coronary artery disease.Methods and ResultsIn 370 consecutive patients undergoing diagnostic coronary angiography, we performed a cytokine array analysis for screening serum levels of 50 cytokines/chemokines and growth factors. Among them, classification and regression analysis identified adipsin as the best biomarker for prediction of their long‐term prognosis (median 71 months; interquartile range, 55–81 months). Kaplan–Meier curve showed that higher adipsin levels (≥400 ng/mL) were significantly associated with all‐cause death (hazard ratio [HR], 4.2; 95% CI, 1.7–10.6 [P<0.001]) and rehospitalization (HR, 2.4; 95% CI, 1.7–3.5 [P<0.001]). Interestingly, higher high‐sensitivity C‐reactive protein levels (≥1 mg/L) were significantly correlated with all‐cause death (HR, 3.2; 95% CI, 1.7–5.9 [P<0.001]) and rehospitalization (HR, 1.5, 95% CI, 1.1–1.9 [P<0.01]). Importantly, the combination of adipsin (≥400 ng/mL) and high‐sensitivity C‐reactive protein (≥1 mg/L) was more significantly associated with all‐cause death (HR, 21.0; 95% CI, 2.9–154.1 [P<0.001]). Finally, the receiver operating characteristic curve demonstrated that serum adipsin levels predict the death caused by acute myocardial infarction in patients with coronary artery disease (C‐statistic, 0.847).ConclusionsThese results indicate that adipsin is a novel biomarker that predicts all‐cause death and rehospitalization in patients with coronary artery disease, demonstrating the novel aspects of the alternative complementary system in the pathogenesis of coronary artery disease.