淫羊藿苷通过miRNA-98-5p介导AMPK/mTOR/ULK1信号通路调节免疫失耐受影响免疫性血小板减少症的研究OA

Objective To explore the mechanism of action by which icariin regulates the loss of immune tolerance to immune thrombocytopenia(ITP)through the microRNA(miRNA)-98-5p-mediated adenosine monophosphate-activated protein kinase(AMPK)/mammalian target of rapamycin(mTOR)/Unc-51-like autophagy-activating kinase 1(ULK1)signaling pathway.Methods The ITP model was established by intraperitoneal injection of guinea pig anti-mouse platelet serum into mice.Another 12 normal mice were taken as the control group.The mice with successful modeling were divided into model group,the experimental-low group,the experimental-high group and the positive drug group.The experimental-low and experimental-high groups and the positive drug group were gavaged with 1.25,5.00 mg·kg-1 icariin and 9.1 mg·kg-1 prednisone acetate,respectively,after the mice were modeled.The levels of platelets(PLT)and hemoglobin(Hb)were detected by automatic blood analyzer;the levels of thrombopoietin(TPO)and inflammatory factors were detected by enzyme-linked immunosorbent assay;the pathological damage of spleen tissue was detected by hematoxylin-eosin staining;megakaryocytes were observed with sternum bone marrow smears;the relative expression level of miRNA-98-5p was detected by real-time fluorescence quantitative polymerase chain reaction;and the protein relative expression levels of the AMPK/mTOR/ULK1 signaling pathway was detected by Western blotting.Results The PLT levels in control group,model group,experimental-low group,experimental-high group and positive drug group were(1 504.56±166.99),(752.68±80.33),(862.95±98.33),(1 212.35±134.23)and(1 363.23±155.33)× 10·L-1,respectively;the Hb levels were(151.33±18.96),(124.11±13.56),(138.32±14.02),(145.33±16.88)and(149.22±16.02)g·L-1,respectively;the TPO levels were(12.05±1.33),(5.86±0.78),(6.62±0.96),(7.85±0.92)and(9.66±0.89)pg·mL-1,respectively;the levels of interleukin-6(IL-6)were(18.96±2.33),(44.33±5.39),(39.25±4.46),(32.32±4.33)and(22.98±3.78)ng·L-1,respectively;the levels of IL-10 were(42.15±6.48),(23.12±3.56),(26.89±3.99),(31.02±4.65)and(33.66±4.86)ng·L-1,respectively;the levels of tumor necrosis factor-ce(TNF-α)were(31.02±4.65),(77.36±8.98),(67.65±7.88),(60.52±7.34)and(40.56±5.99)ng·L-1,respectively;the levels of interferon-gamma(IFN-γ)were(4.33±0.68),(8.33±0.96),(7.35±0.89),(6.02±0.81)and(5.86±0.75)ng·L-1,respectively;the relative expression levels of miRNA-98-5p were 1.00±0.16,1.78±0.21,1.51±0.18,1.22±0.16 and 1.15±0.15,respectively;the relative expression levels of phosphorylated(p)-AMPK/AMPK were 1.00±0.14,1.81±0.28,1.60±0.19,1.31±0.16 and 1.25±0.21,respectively;the relative expression levels of p-mTOR/β-actin were 1.00±0.16,0.48±0.07,0.59±0.09,0.79±0.12 and 0.82±0.14,respectively;the relative expression levels of p-ULK1/β-actin were 1.00±0.15,0.42±0.06,0.53±0.09,0.89±0.14 and 0.93±0.16,respectively.There were statistically significant differences when comparing the above indicators of model group with those of control group,and also when comparing the above indicators of the experimental-low,experimental-high groups and positive drug group with those of model group(P＜0.05,P＜0.01,P＜0.001).Conclusion Icariin regulates the loss of immune tolerance in rats with ITP,inhibits autophagy,and thus elevates platelet levels by down-regulating the expression of miRNA-98-5p and modulating the AMPK/mTOR/ULK1 signaling pathway.