concanavalin-a and Ischemia

Concanavalin A (Con A) exhibited multiple roles in cancer cells. However, the role of Con A in endothelial cells was not reported.. Our present study investigated the potential angiogenic role of Con A in endothelial cells and ischaemic hind-limb mice.. Human umbilical vein endothelial cells and Ea.hy926 cells were employed to determine the effect of Con A (0.3, 1, and 3 μg/mL) or vehicle on angiogenesis and cell proliferation with tube formation, ELISA, flow cytometry, EdU, and western blot. Hind-limb ischaemic mice were conducted to determine the pro-angiogenic effect of Con A (10 mg/kg) for 7 days.. Con A promoted tube formation to about three-fold higher than the control group and increased the secretion of VEGFa, PDGFaa, and bFGF in the medium. The cell viability was promoted to 1.3-fold by Con A 3 μg/mL, and cell cycle progression of G0G1 phase was decreased from 77% in the vehicle group to 70% in Con A 3 μg/mL, G2M was promoted from 15 to 19%, and S-phase was from 7 to 10%. Con A significantly stimulated phosphorylation of Akt and ERK1/2 and expression of cyclin D1 and decreased the expression of p27. These effects of Con A were antagonised by the PI3K inhibitor LY294002 (10 μM) and MEK pathway antagonist PD98059 (10 μM). Moreover, Con A (10 mg/kg) exhibited a repair effect in ischaemic hind-limb mice.. This study will provide a new option for treating ischaemic disease by local injection with Con A.

Topics: Angiogenesis Inducing Agents; Animals; Cell Proliferation; Cell Survival; Chromones; Concanavalin A; Cyclin D1; Dose-Response Relationship, Drug; Flavonoids; Hindlimb; Human Umbilical Vein Endothelial Cells; Humans; Ischemia; Male; MAP Kinase Signaling System; Mice; Mice, Inbred C57BL; Morpholines; Neovascularization, Physiologic; Proto-Oncogene Proteins c-akt

We studied the ex vivo secretion of tumor necrosis factor (TNF) and interleukin 2 (IL-2) by splenocytes after circulatory shock induced by intestinal ischemia and reperfusion in rats. Shock was induced by total occlusion of the superior mesenteric artery followed by reperfusion. In a second group, vascular occlusion was maintained throughout the experimental protocol. A third group of sham rats and a fourth group of control rats with a negligible surgical procedure were also studied. "Spontaneous" (untriggered) secretion of TNF by splenocytes was higher in the ischemia-reperfusion group than in all other groups (p < 0.01), but did not increase significantly after stimulation with LPS. Splenocytes from control rats exhibited a marked increase in TNF secretion after stimulation with LPS to values similar to those in the ischemia-reperfusion group. A diminished, though statistically significant increase in LPS-stimulated secretion of TNF was detected in the sham and ischemia only groups of rats (p < 0.05) from untriggered values in each. Untriggered secretion of IL-2 was similar in all groups. However, when compared to control rats, splenocytes from the three surgically manipulated groups exhibited suppressed secretion of IL-2 in response to stimulation with Con A (p < 0.05). These results support the role played by TNF in mediation of shock and point to spleen macrophages as a source of TNF after intestinal ischemia and reperfusion. Our results also demonstrated postinjury alteration in immune function manifested by depressed ability of splenocytes to increase the production of IL-2 after stimulation with Con A.

Topics: Animals; Cells, Cultured; Concanavalin A; Interleukin-2; Intestines; Ischemia; Lipopolysaccharides; Macrophages; Male; Rats; Rats, Sprague-Dawley; Reperfusion; Shock; Spleen; Tumor Necrosis Factor-alpha