ag-490 and Stroke

The present study aims to investigate the protective effects of the SOCS1-JAK2-STAT3 signaling pathway on neurons in a rat model of ischemic stroke.. Our study was conducted using an ischemic stroke rat model. After the microglia were extracted, 40 neonatal Sprague-Dawley (SD) rats were assigned into the blank, AG490, model and negative control (NC) groups. The neurological function of all the rats was evaluated. Histopathological changes were observed. qRT-PCR and western blotting were applied to measure the expression of genes and proteins in the SOCS1-JAK2-STAT3 signaling pathway and related to apoptosis. The TUNEL assay was conducted to calculate the cellular morphology and apoptosis of neuronal cells. Cell viability was detected using the MTT assay. In addition, immunoassays were used to measure the content of superoxide dismutase (SOD), glutathione (GSH) and malondialdehyde (MDA) as well as the levels of oxidative stress.. Compared with the blank group, the model and NC groups showed higher neurological function scores-the cytoplasm of the neurons were cavitated, the organelles were reduced with unclear margins, some of the neurons were necrotic, and apoptosis was increased. In addition, the NC and model groups exhibited decreased cell viability, lower mRNA and protein expression of SOCS1 SOCS3 and bcl-2 and reduced SOD and GSH levels but higher mRNA and protein expression levels of AK2, STAT3,Bax and caspase-3 as well as increased protein expression of P-JAK2, P-STAT3 and activated caspase-3 (c-caspase-3). Moreover, the MDA levels were up-regulated in the NC and model groups. In contrast, opposing trends were found in the AG490 group compared with the NC and model groups.. These data demonstrate that inhibiting the SOCS1-JAK2-STAT3 signaling pathway can reduce the loss of nerve function and apoptosis of neuronal cells, which provides a new target for the clinical treatment of ischemic stroke.

Topics: Animals; Apoptosis; bcl-2-Associated X Protein; Caspase 3; Disease Models, Animal; Glutathione; Janus Kinase 2; Male; Malondialdehyde; Neurons; Oxidative Stress; Proto-Oncogene Proteins c-bcl-2; Rats; Rats, Sprague-Dawley; Signal Transduction; STAT3 Transcription Factor; Stroke; Superoxide Dismutase; Suppressor of Cytokine Signaling 1 Protein; Tyrphostins

Epidemiological studies have linked the consumption of phenolic acids with reduced risk of cardiovascular diseases. In the present study, we sought to investigate whether caffeic acid, a phenolic acid which is abundant in normal diet, can antagonize angiotensin II (Ang II)-induced vascular smooth muscle cell (VSMC) proliferation in stroke-prone spontaneously hypertensive rats (SHRSP) and Wistar-Kyoto (WKY) rats, and if so, to elucidate the underlying cell signaling mechanisms. We exposed VSMCs to Ang II and caffeic acid and found that caffeic acid significantly inhibited intracellular superoxide anion generation (decreased from 127 +/- 6.3% to 100.3 +/- 6.6% of the control cells) and the cell proliferation induced by Ang II. Furthermore, caffeic acid significantly abolished the tyrosine phosphorylation of JAK2 (decreased from 7.4 +/- 0.6-fold to 2.4 +/- 0.6-fold at 2 min) and STAT1 (decreased from 1.8 +/- 0.2-fold to 0.5 +/- 0.1-fold at 2 min) and the phosphorylation of ERK1/2 (decreased from 99.2 +/- 10.2-fold to 49.8 +/- 10.9-fold at 2 min) that were induced by Ang II. These effects of caffeic acid were consistent with the inhibition of the proliferation of VSMCs by DPI, an NADPH oxidase inhibitor, and by AG-490, a JAK2 inhibitor. In conclusion, our findings suggest that caffeic acid attenuates the proliferative reaction of VSMCs to Ang II stimulation in both SHRSP and WKY rats by inhibiting the generation of reactive oxygen species and then partially blocking the JAK/STAT signaling cascade and the Ras/Raf-1/ERK1/2 cascade.

Topics: Angiotensin II; Animals; Antioxidants; Caffeic Acids; Cell Division; DNA-Binding Proteins; Drug Interactions; Enzyme Inhibitors; HSP90 Heat-Shock Proteins; Hypertension; Janus Kinase 2; Male; Mitogen-Activated Protein Kinase 1; Mitogen-Activated Protein Kinase 3; Muscle, Smooth, Vascular; Phosphorylation; Protein-Tyrosine Kinases; Proto-Oncogene Proteins; Rats; Rats, Inbred SHR; Rats, Inbred WKY; Signal Transduction; STAT1 Transcription Factor; Stroke; Superoxides; Trans-Activators; Tyrosine; Tyrphostins; Vasoconstrictor Agents