The Effect Of Local Ischemia On Mtor Signaling Pathway

PARTI MOUSE MODEL OF SKIN ISCHEMIAObjective:To establish the model of acute skin ischemia in Kun Ming mice.Methods:Forty female kun Ming mice were divided into A and B two groups randomly,20in each group. Group A U-shaped peninsular incision, which is1.5cm in width and3.3cm in length, as deep as full thickness, was created on the back of A-group kun Ming mice. Group B U-shaped peninsular incision, which is1.5cm in width and2.5cm in length, as deep as skin fascia, was created on the back of the other female kun Ming mice. Before suturing flaps back in place, a2-mm-wild medical rubber sheet was inserted to separate the flap edges. Then the flaps were observed and the blood flow of flaps were measured by The full-field laser perfusion imager (FLPI; Moor Instruments Ltd).Results:50%of the longer flaps had approximately (37.20±4.83)%necrosis on the second postoperative day.All of the longer flaps developed a considerable amount of distal necrosis rate on the third postoperative day, which was increase with time. The smaller flaps displayed cyanosis and edema on the first postoperative day. The area of cyanosis and edema accounted for (77.46±4.51)%, and was followed by a progressive decrease over the course of5d. Cyanosis, edema completely dissipated until the seventh day.There was a significant decrease in the flap blood flow on the first day after operation (p<0.05). There was no distinctly significance until the seventh day.Conclusion:We have Successfully established a Kun Ming mouse model of skin ischemia, which has numerous advantages, including ease of handling, low cost, stability and effectivity. PART2THE EFFECT OF LOCAL ISCHEMIA ON MTOR SIGNALING PATHWAYObjective:To explore the impact of ischemia on protein translation signaling pathway By studying the impact of ischemia on the expression of P-4E-BP1, P-p70S6K, P-S6in tissue.Methods:30Kun ming mice were randomly divided into6groups(5in each group):normal control group (ischemia for0minute group) ischemia for15minutes group, ischemia for30minutes group, ischemia for1hour group, ischemia for4hours group and24hours group. Then a 2.5x1.5cm U-shaped flap was established on each kun ming mouse in the experimental groups. The expression of P-4E-BP1, P-p70S6K, P-S6at different time points after ischemia were detected with western blotting.Results:P-p70S6K and P-S6were significantly increased at30mins and1h after ischemia(P<0.05). P-4E-BP1was significantly increased at15mins,30mins and1h after ischemia (P<0.05).All of these proteins were significantly decreased at24h after ischemia.(P<0.05or P<0.01).Conclusion: Temporary ischemia (ischemia less than one hour) can increase phosphorylation of4E-BP1, p70S6K and S6, and promote protein translation; Long-time ischemia (ischemia for24hours) can inhibit phosphorylation of4E-BPl,p70S6K,S6and protein translation.