Platelet microparticles-containing miR-4306 inhibits human monocyte-derived macrophages migration through VEGFA/ERK1/2/NF-κB signaling pathways.

Platelets are major sources of microparticles (MPs) in peripheral bloodstream, and platelet-secreted MPs (P-MPs) transfer biological information to neighboring cells. In the present study, we found that the platelet- and P-MPs-derived microRNA-4306 (miR-4306) expression were downregulated in coronary artery disease (CAD) and platelet-derived miR-4306 was an independent poor prognostic factor in CAD. Plasma miRNA-4306 mainly cofractionated with MPs instead of Argonaute2 complexes or HDL. P-MPs could effectively deliver miR-4306 into human monocyte-derived macrophages (HMDMs). MiR-4306 noticeably inhibited the HMDMs migration in vitro and reduced the number of macrophage cells in cardiac tissue in myocardial infarction mice. This functional impact of miR-4306 was mediated directly through VEGFA to inhibit ERK/NF-κB signaling. In conclusion, our study suggested that intercellular transfer of miR-4306 by platelet microparticles inhibited the HMDMs migration through VEGFA/ERK1/2/NF-κB signaling pathways.

Association Between C1q/TNF-Related Protein-1 Levels in Human Plasma and Epicardial Adipose Tissues and Congestive Heart Failure.

BACKGROUND/AIMS: C1q and tumour necrosis factor-related protein 1 (CTRP1) possesses anti-atherogenic and anti-inflammatory effects. This study investigated whether the CTRP1 levels in the plasma and epicardial adipose tissue (EAT) were associated with congestive heart failure (CHF) and to disclose possible molecular mechanisms. METHODS: Plasma and tissue samples were obtained from subjects with or without CHF. Plasma levels of CTRP1 were measured by ELISA. The mRNA levels of CTRP1 and inflammatory cytokines were detected by RT-PCR. The protein levels of CTRP1, aldosterone synthase (CYP11B2) and mitogen-activated protein kinase were examined by Western blotting. RESULTS: The levels of CTRP1 in the plasma and EAT were higher in the CHF patients than those in the controls. There were no differences in the CTRP1 levels in cardiomyocytes between the CHF group and the non-CHF group. An exploratory survival analysis showed that higher CTRP1 values at admission were associated with a worse prognosis after discharge. CTRP1 increased the IL-6 mRNA level in H295R cells. CTRP1 recruited ERK1/2 and Jak-2 for aldosterone release by modulating the CYP11B2 protein level, and brain natriuretic peptide repressed the CTRP1-induced aldosterone release through the JAK2-STAT3 signalling pathways. CONCLUSION: The CTRP1 levels in the plasma and EAT were increased in the CHF patients. CTRP1 is involved in the pathogenesis of CHF by modulating IL-6 levels and aldosterone release.

Pregestational diabetes induces fetal coronary artery malformation via reactive oxygen species signaling.

Hypoplastic coronary artery disease is a congenital coronary artery malformation associated with a high risk of sudden cardiac death. However, the etiology and pathogenesis of hypoplastic coronary artery disease remain undefined. Pregestational diabetes increases reactive oxygen species (ROS) levels and the risk of congenital heart defects. We show that pregestational diabetes in mice induced by streptozotocin significantly increased 4-hydroxynonenal production and decreased coronary artery volume in fetal hearts. Pregestational diabetes also impaired epicardial epithelial-to-mesenchymal transition (EMT) as shown by analyses of the epicardium, epicardial-derived cells, and fate mapping. Additionally, the expression of hypoxia-inducible factor 1α (Hif-1α), Snail1, Slug, basic fibroblast growth factor (bFgf), and retinaldehyde dehydrogenase (Aldh1a2) was decreased and E-cadherin expression was increased in the hearts of fetuses of diabetic mothers. Of note, these abnormalities were all rescued by treatment with N-acetylcysteine (NAC) in diabetic females during gestation. Ex vivo analysis showed that high glucose levels inhibited epicardial EMT, which was reversed by NAC treatment. We conclude that pregestational diabetes in mice can cause coronary artery malformation through ROS signaling. This study may provide a rationale for further clinical studies to investigate whether pregestational diabetes could cause hypoplastic coronary artery disease in humans.

Rac1 signaling is critical to cardiomyocyte polarity and embryonic heart development.

BACKGROUND: Defects in cardiac septation are the most common form of congenital heart disease, but the mechanisms underlying these defects are still poorly understood. The small GTPase Rac1 is implicated in planar cell polarity of epithelial cells in Drosophila; however, its role in mammalian cardiomyocyte polarity is not clear. We tested the hypothesis that Rac1 signaling in the second heart field regulates cardiomyocyte polarity, chamber septation, and right ventricle development during embryonic heart development. METHODS AND RESULTS: Mice with second heart field-specific deficiency of Rac1 (Rac1(SHF)) exhibited ventricular and atrial septal defects, a thinner right ventricle myocardium, and a bifid cardiac apex. Fate-mapping analysis showed that second heart field contribution to the interventricular septum and right ventricle was deficient in Rac1(SHF) hearts. Notably, cardiomyocytes had a spherical shape with disrupted F-actin filaments in Rac1(SHF) compared with elongated and well-aligned cardiomyocytes in littermate controls. Expression of Scrib, a core protein in planar cell polarity, was lost in Rac1(SHF) hearts with decreased expression of WAVE and Arp2/3, leading to decreased migratory ability. In addition, Rac1-deficient neonatal cardiomyocytes displayed defects in cell projections, lamellipodia formation, and cell elongation. Furthermore, apoptosis was increased and the expression of Gata4, Tbx5, Nkx2.5, and Hand2 transcription factors was decreased in the Rac1(SHF) right ventricle myocardium. CONCLUSIONS: Deficiency of Rac1 in the second heart field impairs elongation and cytoskeleton organization of cardiomyocytes and results in congenital septal defects, thin right ventricle myocardium, and a bifid cardiac apex. Our study suggests that Rac1 signaling is critical to cardiomyocyte polarity and embryonic heart development.

Discussion about several potential drawbacks of PEGylated therapeutic proteins.

PEGylation changes the physical and chemical properties of the biomedical molecule, such as its conformation, electrostatic binding, and hydrophobicity, and results in an improvement in the pharmacokinetic behavior of the drug, while it also causes some disadvantages of which cannot be neglected. The available data manifests that polyethylene glycol (PEG) itself shows potential risk, such as immunogenicity of the PEG and PEG-containing vacuoles in cells observed with PEGylated biologicals. Decreased activity and heterogeneity are also the negative aspects of PEGylation. The unfavorable impacts which are brought by the PEGylation are described here with examples of modified therapeutic proteins on the market and used in the clinical trials.

[Effect of madecassoside on depression behavior of mice and activities of MAO in different brain regions of rats].

OBJECTIVE: To evaluate the effects of madecassoside (MC) on the depression behavior of mice and the activities of monoamine oxidase (MAO) in different rat brain regions. METHODS: Imipramine as the positive contrast medicine, effects of MC on the depression behavior of mice were observed by forced swimming test and reserpine antagonist test. Moclobemide and pargyline as the positive controlled medicines, the activities of monoamine oxidase-A (MAO-A) and monoamine oxidase-B (MAO-B) in different rat brain regions were determined after intragastric administration of MC in 3 different dosages for 3 days or 21 days. RESULTS: (1) The low, middle and high dosages of MC (i.g.) significantly reduced the immobility time of mice in forced swimming test (P<0.05). (2) MC in dosages of 10 mg/kg and 20 mg/kg prevented the lowering of temperature induced by reserpine (P<0.05), while 40 mg/kg had no significant effects on it (P>0.05). (3) With acute administration (3 days), the low, middle and high dosagey of MC (i.g.) significantly inhibited the activity of MAO-A in hippocampus (P<0.01), and the high dosage significantly inhibited the activity of MAO-A in hypothalamus (P<0.01), while the 3 dosages had no significant effects on the activity of MAO-A in cortex (P>0.05). With chronic administration (21 days), MC in 3 dosages had no significant effects on the activities of MAO-A in cortex and hypothalamus (P>0.05), and the high dosage (40 mg/kg) significantly enhanced the activity of MAO-A in hippocampus (P<0.01). (4) With acute administration, MC in dosages of 10 mg/kg and 20 mg/kg significantly inhibited the activity of MAO-B in cortex (P>0.05), and MC in dosage of 10 mg/kg significantly inhibited the activity of MAO-B in hypothalamus (P<0.05), and MC in dosage of 20 mg/kg significantly enhanced the activity of MAO-B in hippocampus (P<0.01). With chronic administration, MC of 3 dosages produced no significant effects on the activities of MAO-B in 3 different rat brain regions (P>0.05). CONCLUSION: These results support the idea that MC produces antidepressant effects through MAO inhibition in rat brain, which seems stronger with acute administration than chronic administration, while its mechanism remains to be further studied.