Glycogen synthase kinase-3ß inhibition alleviates activation of the NLRP3 inflammasome in myocardial infarction.

Inflammasome-promoted sterile inflammation following cardiac damage is critically implicated in heart dysfunction after myocardial infarction (MI). Glycogen synthase kinase-3 (GSK-3ß) is a prominent mediator of the inflammatory response, and high GSK-3 activity is associated with various heart diseases. We investigated the regulatory mechanisms of GSK-3ß in activation of the nod-like receptor family pyrin domain containing 3 (NLRP3) inflammasome in a rat model with successful induction of MI on days 2-28. An in vitro investigation was performed using newborn rat/human cardiomyocytes and fibroblast cultures under typical inflammasome stimulation and hypoxia treatment. GSK-3ß inhibition markedly improved myocardial dysfunction and prevented remodeling, with parallel reduction in the parameters of NLRP3 inflammasome activation after MI. GSK-3ß inhibition reduced NLRP3 inflammasome activation in cardiac fibroblasts, but not in cardiomyocytes. GSK-3ß's interaction with activating signal cointegrator (ASC) as well as GSK-3ß inhibition reduced ASC phosphorylation and oligomerization at the tissues and cellular levels. Taken together, these data show that GSK-3ß directly mediates NLRP3 inflammasome activation, causing cardiac dysfunction in MI.

Inulin with a low degree of polymerization protects human umbilical vein endothelial cells from hypoxia/reoxygenation-induced injury.

Here, we identified inulin-type oligosaccharides with 3-13 degrees of polymerization from Morinda officinalis. Radical-scavenging assays showed that Inulins 4-7 had modest anti-oxidative effects. Inulins 4 and 5 dose-dependently increased human umbilical vein endothelial cell survival during hypoxia/re-oxygenation (H/R)-induced injury, and Inulin 5 promoted angiogenesis. Triplicate assays with the Affymetrix Human Transcriptome Array 2.0 showed that Inulin 5 exposure up-regulated genes associated with cell cycle progression, apoptosis, DNA replication and repair, ubiquitin-mediated proteolysis, the mitogen-activated protein kinase pathway, and the phosphatidylinositol-4,5-bisphosphate 3-kinase (PI3K)-signaling pathway. Flow cytometry, reverse transcription-quantitative polymerase chain reaction, and western blot experiments verified the microarray results and demonstrated that Inulin 5 influenced cell cycle progression and the PI3K-protein kinase B (PKB)-endothelial nitric oxide synthase (eNOS) pathway. Thus, inulin-type oligosaccharides from M. officinalis roots may protect against H/R-induced injury, primarily through an anti-oxidative effect, and promote angiogenesis by activating the PI3K-PKB-eNOS-signaling pathway.

Synthesis and biological activity of n-butylphthalide derivatives.

A series of n-butylphthalide derivatives were designed and synthesized. The in vitro activities of these compounds were evaluated by a resting tension of isolated rat thoracic aorta ring assay. Compounds 4g and 4i were found to be more active than n-butylphthalide.