The role of peroxisome proliferator-activated receptor-γ/nuclear factor-ΚB transduction pathway on coagulation disorders induced by sepsis

Abstract

To determine the role of activated status of peroxisome proliferator-activated receptorγ/nuclear factor-ΚB (PPAR-γ/NF-ΚB ) in coagulation disorders induced by sepsis. Forty male Sprague-Dawley (SD) rats were randomly divided into four groups, n=10 in each group: control group, lipopolysaccharide (LPS) challenged group, rosiglitazone (ROSI, selective agonist of PPAR-γ) pretreatment group, and GW9662 (PPAR-γ antagonist) pretreatment group. The sepsis model was reproduced by injection of 6 mg/kg LPS via sublingual vein, and the rats in control group were injected with 2 mL/kg normal saline. The rats in ROSI pretreatment group were given 0.3 mg/kg ROSI by sublingual venous injection followed by injection of LPS 30 minutes later; and in GW9662 pretreatment group rats were given 0.3 mg/kg GW9662 by sublingual venous injection followed by 0.3 mg/kg ROSI 15 minutes later, followed by injection of LPS 30 minutes later. Blood was collected at 4 hours after LPS administration, and the expressions of PPAR-γ and NF-ΚBp65 in peripheral blood mononuclear cell (PBMC) were determined with immunocytocheminal technique and graph analysis. Plasma prothrombin time (PT), activated partial thromboplastin time (APTT), fibrinogen (FIB), and D-dimer were determined simultaneously. (1) PPAR-γ/NF-ΚB pathway: the expressions of PPAR-γ and NF-ΚBp65 were lowered in control group, and they were expressed in cytoplasm. In LPS challenged group the expression of PPAR-γ (gray value) was slightly increased but with no significant difference as compared with control group (111.01±4.06 vs. 98.46±5.99, P>0.05). In ROSI pretreatment group the expression of PPAR-γ (gray value) was significantly higher than that in LPS challenged group (214.38±5.79 vs. 111.01±4.06, P<0.01), with dislocation into nuclei. In GW9662 pretreatment group the expression of PPAR-γ (gray value) was lowered but without significant difference compared with that of control group (44.21±2.64 vs. 98.46±5.99, P>0.05). In LPS challenged group the expression of NF-ΚBp65 (gray value) was significantly higher than that in control group (249.48±6.86 vs. 105.81±10.19, P<0.01), and it was translocated into the nuclei. In ROSI pretreatment group the expression of NF-ΚBp65 (gray value) was significantly lower than that in LPS challenged group (102.47±8.05 vs. 249.48±6.86, P<0.01), and it lied in cytoplasm. In GW9662 pretreatment group the expression of NF-ΚBp65 (gray value) showed no significant difference as compared with that of LPS challenged group (214.84±7.91 vs. 249.48±6.86, P>0.05). (2) Coagulation: compared with control group, PT and APTT were significantly prolonged, FIB was significantly decreased, and D-dimer was significantly increased in LPS challenged group [PT (s): 18.32±2.03 vs. 12.22±1.38, APTT (s): 40.05±2.72 vs. 26.64±2.73, FIB (g/L): 1.65±0.51 vs. 3.60±0.37, D-dimer (mg/L): 2.58±0.73 vs. 0.37±0.06, all P<0.01]. Compared with LPS challenged group, APTT and PT were significantly shortened, FIB was significantly increased, and D-dimer was significantly lowered in ROSI pretreatment group [PT (s): 13.93±1.67 vs. 18.32±2.03, APTT (s): 30.29±0.86 vs. 40.05±2.72, FIB (g/L): 3.18±0.69 vs 1.65±0.51, D-dimer (mg/L): 0.40±0.12 vs. 2.58±0.73, all P<0.01]. All parameters in GW9662 pretreatment group showed no significant difference as compared with those of LPS challenged group. PPAR-γ agonist ROSI may ameliorate coagulation disorders in septic rats. PPAR-γ/NF-ΚB transduction pathway plays an important role in septic coagulopathy.