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Background and Aims: Interleukin-1 receptor-associated kinase-1 (IRAK-1) is critical for mediating toll-like receptor and interleukin-1 receptor signaling. In this study, we have examined whether IRAK-1 expression is altered in high glucose (HG)-stimulated human aortic endothelial cells (HAECs), and whethermicroRNAs (miRs) target IRAK-1 to regulate HG-induced endothelial inflammation. Methods: HAECs were treated with HG for 24 and 48 h. Real-time PCR, Western blot, monocyte adhesion assay, bioinformatics analysis, TaqMan® arrays, microRNA mimic or inhibitor transfection, luciferase reporter assay and siRNA IRAK-1 transfection were performed. The aortic tissues from db/db type 2 diabetic mice were examined by immunohistochemistry staining. Results: HG time-dependently increased IRAK-1 mRNA and protein levels in HAECs, and was associated with increased VCAM-1/ICAM-1 gene expression and monocyte adhesion. Bioinformatic analysis, TaqMan® arrays, and real-time PCR were used to confirm that miR-146a-5p, miR-339-5p, and miR-874-3p were significantly downregulated in HG-stimulated HAECs, suggesting impaired feedback restraints on HG-induced endothelial inflammation via IRAK-1. However, only miR-146a-5p mimic transfection reduced the HG-induced upregulation of IRAK-1 expression, VCAM-1/ICAM-1 expression, and monocyte adhesion. Additionally, IRAK-1 depletion reduced HG-induced VCAM-1/ICAM-1 gene expression, and monocyte adhesion, indicating that HG-induced endothelial inflammation was mediated partially through IRAK-1. In vivo, intravenous injections of miR-146a-5p mimic prevented endothelial IRAK-1 and ICAM-1 expression in db/db mice. Conclusion: These results suggest that miR-146a-5p is involved in the regulation of HG-induced endothelial inflammation via modulation of IRAK-1; indicating that miR-146a-5p may be a novel target for the treatment of diabetic vascular complications. [ABSTRACT FROM AUTHOR]

A tropical species, the euryhaline milkfish (Chanos chanos), is a crucial economic species in Southeast Asia and is intolerant of water temperature below 12°C. Large numbers of milkfish die during cold periods in winter. Hypothermal environments usually increase oxidative stress in teleosts, and the liver is the major organ for anti-oxidative responses in the body. Peroxiredoxin-6 (Prdx6) in mammals is a multi-functional enzyme and acts as both glutathione peroxidase, phospholipase A2 and acyl-transferase for maintenance of redox status and prevention of cell membrane peroxidation. Prdx6 can protect cells from oxidant-induced membrane damage by translocating the Prdx6 protein from the cytosol to the membrane. Upon cold stress, Ccprdx6 transcript levels were up-regulated after 24 h and 96 h in livers of fresh water (FW)- and seawater (SW)-acclimated milkfish, respectively. In the hypothermal FW group, the Prdx6 protein was up-regulated in the cytosol of hepatocytes with a similar role as glutathione peroxidase to reduce oxidative stress upon hypothermal challenge. Conversely, in hypothermal SW milkfish, total Prdx6 protein was down-regulated. However, cytosolic Prdx6 protein was translocated to the membrane, using the ability of phospholipase A2 to stabilize the membrane redox state. Moreover, H2O2 content was increased in FW-acclimated milkfish livers upon hypothermal challenge. Ex vivo H2O2 treatment of milkfish livers also induced Ccprdx6 transcriptional expression, which provided more evidence of the antioxidant role of milkfish Prdx6. Taken together, upon hypothermal challenge, greater oxidative stress in livers of FW-acclimated milkfish rather than SW-acclimated individuals led to different profiles of hepatic CcPrdx6 expression between the FW and SW group. The results indicated that CcPrdx6 played the role of antioxidant with different mechanisms, i.e., binding to reactive oxygen species and stabilizing membrane fluidity, in livers of hypothermal FW and SW milkfish, respectively. [ABSTRACT FROM AUTHOR]

Diabetes is associated with hyperglycemia and increased thrombin production. However, it is unknown whether a combination of high glucose and thrombin can modulate the expression of NAPDH oxidase (Nox) subtypes in human aortic endothelial cells (HAECs).Moreover, we investigated the role of a diabetes-associated microRNA (miR-146a) in a diabetic atherothrombosismodel. We showed that high glucose (HG) exerted a synergistic effect with thrombin to induce a 10.69-fold increase in Nox4 mRNA level in HAECs. Increased Nox4 mRNA expression was associated with increased Nox4 protein expression and ROS production. Inflammatory cytokine kit identified that the treatment increased IL-8 and IL-6 levels. Moreover, HG/thrombin treatment caused an 11.43-fold increase of THP-1 adhesion to HAECs. In silico analysis identified the homology between miR-146a and the 3'- untranslated region of the Nox4 mRNA, and a luciferase reporter assay confirmed that the miR-146a mimic bound to this Nox4 regulatory region. Additionally, miR-146a expression was decreased to 58% of that in the control, indicating impaired feedback restraint of HG/thrombin-induced endothelial inflammation. In contrast, miR-146a mimic transfection attenuated HG/thrombininduced upregulation of Nox4 expression, ROS generation, and inflammatory phenotypes. In conclusion, miR-146a is involved in the regulation of endothelial inflammation via modulation of Nox4 expression in a diabetic atherothrombosis model. [ABSTRACT FROM AUTHOR]

AbstractAim:Ferulic acid (4-hydroxy-3-methoxycinnamic acid, FA) provides neuroprotection against apoptosis in a transient middle cerebral artery occlusion (MCAo) model. This study was to further investigate the anti-apoptotic effect of FA during reperfusion after cerebral ischemia.Methods:Rats were subjected to 90 min of cerebral ischemia followed by 3 or 24 h of reperfusion after which they were sacrificed.Results:Intravenous FA (100 mg/kg) administered immediately after middle cerebral artery occlusion (MCAo) or 2 h after reperfusion effectively abrogated the elevation of postsynaptic density-95 (PSD-95), neuronal nitric oxide synthase (nNOS), inducible nitric oxide synthase (iNOS), nitrotyrosine, and cleaved caspase-3 levels as well as apoptosis in the ischemic cortex at 24 h of reperfusion. FA further inhibited Bax translocation, cytochrome c release, and p38 mitogen-activated protein (MAP) kinase phosphorylation. Moreover, FA enhanced the expression of gamma-aminobutyric acid type B receptor subunit 1 (GABAB1) in the ischemic cortex at 3 and 24 h of reperfusion. In addition, nitrotyrosine-positive cells colocalized with cleaved caspase-3-positive cells, and phospho-p38 MAP kinase-positive cells colocalized with nitrotyrosine- and Bax-positive cells, indicating a positive relationship among the expression of nitrotyrosine, phospho-p38 MAP kinase, Bax, and cleaved caspase-3. The mutually exclusive expression of GABAB1 and nitrotyrosine revealed that there is a negative correlation between GABAB1 and nitrotyrosine expression profiles. Additionally, pretreatment with saclofen, a GABAB receptor antagonist, abolished the neuroprotection of FA against nitric oxide (NO)-induced apoptosis.Conclusion:FA significantly enhances GABAB1 receptor expression at early reperfusion and thereby provides neuroprotection against p38 MAP kinase-mediated NO-induced apoptosis at 24 h of reperfusion. [ABSTRACT FROM AUTHOR]

Our previous studies have shown that Uncaria rhynchophylla (UR) can reduce epileptic seizures. We hypothesized that UR and its major component rhynchophylline (RH), reduce epileptic seizures in rats treated with kainic acid (KA) by inhibiting nuclear factor-κB (NF-κB) and activator-protein-1 (AP-1) activity, and by eliminating superoxide anions. Therefore, the level of superoxide anions and the DNA binding activities of NF-κB and AP-1 were measured. Sprague-Dawley (SD) rats were pre-treated with UR (1.0 g/kg, i.p.), RH (0.25 mg/kg, i.p.), or valproic acid (VA, 250 mg/kg, i.p.) for 3 days and then KA was administered intra-peritoneal (i.p.). The results indicated that UR, RH, and VA can reduce epileptic seizures and the level of superoxide anions in the blood. Furthermore, KA was demonstrated to induce the DNA binding activities of NF-κB and AP-1. However, these inductions were inhibited by pre-treatment with UR, RH, or VA for 3 days. Moreover, UR and RH were shown to be involved in the suppression of c-Jun N-terminal kinase (JNK) phosphorylation. This study suggested that UR and RH have antiepileptic effects in KA-induced seizures and are associated with the regulation of the innate immune system via a reduction in the level of superoxide anions, JNK phosphorylation, and NF-κB activation. [ABSTRACT FROM AUTHOR]