Inflammation plays a key role in pressure overload‐induced cardiac hypertrophy and heart failure, but the mechanisms have not been fully elucidated. High‐mobility group box 1 (HMGB1), which is increased in myocardium under pressure overload, may be involved in pressure overload‐induced cardiac injury. The objectives of this study are to determine the role of HMGB1 in cardiac hypertrophy and cardiac dysfunction under pressure overload. Pressure overload was imposed on the heart of male wild‐type mice by transverse aortic constriction (TAC), while recombinant HMGB1, HMGB1 box A (a competitive antagonist of HMGB1) or PBS was injected into the LV wall. Moreover, cardiac myocytes were cultured and given sustained mechanical stress. Transthoracic echocardiography was performed after the operation and sections for histological analyses were generated from paraffin‐embedded hearts. Relevant proteins and genes were detected. Cardiac HMGB1 expression was increased after TAC, which was accompanied by its translocation from nucleus to both cytoplasm and intercellular space. Exogenous HMGB1 aggravated TAC‐induced cardiac hypertrophy and cardiac dysfunction, as demonstrated by echocardiographic analyses, histological analyses and foetal cardiac genes detection. Nevertheless, the aforementioned pathological change induced by TAC could partially be reversed by HMGB1 inhibition. Consistent with the in vivo observations, mechanical stress evoked the release and synthesis of HMGB1 in cultured cardiac myocytes. This study indicates that the activated and up‐regulated HMGB1 in myocardium, which might partially be derived from cardiac myocytes under pressure overload, may be of crucial importance in pressure overload‐induced cardiac hypertrophy and cardiac dysfunction.

Characteristics of heart failure with preserved ejection fraction (HFPEF) have not yet been fully understood. The objectives of this pilot study are to detect protein expression profile in the sera of HFPEF patients, and to identify potential biomarkers for the disease. Five hundred and seven proteins were detected in the sera of healthy volunteers and patients with either HFPEF or hypertension using antibody microarrays (three in each group). The results showed that the serum concentrations of 17 proteins (e.g. angiogenin, activin A and artemin) differed considerably between HFPEF and non‐HFPEF patients (hypertensive patients and healthy controls), while a protein expression pattern distinct from that in non‐HFPEF patients was associated with HFPEF patients. The up‐regulation of angiogenin in both HFPEF patients with LVEF ≥50% (P = 0.004) and a subset of HFPEF patients with LVEF = 41–49% (P < 0.001) was further validated in 16 HFPEF patients and 16 healthy controls. Meanwhile, angiogenin distinguished HFPEF patients from controls with a mean area under the receiver operating characteristic curve of 0.88 (P < 0.001) and a diagnostic cut‐off point of 426 ng/ml. Moreover, the angiogenin levels in HFPEF patients were positively correlated with Lg(N‐terminal pro‐B‐type natriuretic peptide, NT‐proBNP) (P < 0.001). In addition, high angiogenin level (≥426 ng/ml) was a predictor of all‐cause death within a short‐term follow‐up duration, but not in the longer term of 36 months. This pilot study indicates that the aforementioned 17 potential biomarkers, such as angiogenin, may hold great promise for both diagnosis and prognosis assessment of HFPEF.

Atherosclerosis, as a chronic inflammatory disease, is the major underlying cause of death worldwide. However, the mechanisms that underlie the inflammatory process are not completely understood. Prolyl-isomerase-1 (Pin1), as a unique peptidyl-prolyl isomerase, plays an important role in inflammation and endothelial dysfunction. Herein, we investigate whether Pin1 regulates vascular inflammation and atherosclerosis, and clarify its mechanisms in these processes. ApoE^−/− mice were randomly given either juglone (0.3, 1 mg/kg, two times per week) or vehicle i.p. for 4 weeks. Compared with ApoE^−/− mice, treatment by juglone resulted not only in markedly attenuated macrophage infiltration and atherosclerotic lesion area in a lipid-independent manner, but also in decreased expression of Pin1, vascular cell adhesion molecule-1 (VCAM-1), monocyte chemoattractant protein-1 (MCP-1), and NF-κB activity in aorta. Then, EA.hy926 cells were pretreated with juglone (6 μmol/L), Pin1 siRNA, NF-κB inhibitor, or vehicle prior to exposure to ox-LDL (50 μg/mL). It was observed that treatment with juglone or Pin1 siRNA suppressed expression of VCAM-1 in oxLDL-incubated EA.hy926 cells and decreased THP-1 cell adhesion to oxLDL-stimulated endothelial cells through the NF-κB signal pathway. Our findings indicate that Pin1 plays a vital role on the development of vascular inflammation and atherosclerosis.