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Objective: To explore the expression and roles of nucleolin in cardiac injury in septic mice. Methods: C57BL/6 mice (WT mice) and myocardium-specific expression of nucleolin transgenic mice (TG mice) were randomly divided into sham group ( n= 10, sham-operated) and sepsis group ( n= 15, animal model). Cecal ligation and puncture (CLP) was adopted to produce animal models of sepsis. The expression of nucleolin was detected by Western blotting analysis at 0, 12, 24, 48 hours after the operation. The 7-day survival rate, haemodynamic measurement, levels of isoenzyme of creatinekinase-MB (CK-MB) and cardiac troponin I (cTnI) in serum and levels of reactive oxygen species (ROS) and malondlaldehyde (MDA) in myocardium were evaluated 24 hours after the operation. The data were compared between groups with t test. Results: The expression of nucleolin in myocardium up-regulated significantly in WT+CLP group when compared with that in the WT+Sham group(2.57±0.34 vs 1.00±0.15, t= 7.468, P< 0.01). Compared with those in the WT+Sham group, the survival rate decreased (33.3% vs 100%, χ(2)=13.375, P< 0.01), maximal rate of pressure development (+dp/dtmax) declined ( t= 4.993, P< 0.01), but the serum levels of CK-MB and cTnI and the levels of ROS and MDA in myocardium increased in the WT+CLP group( t= 5.031, 4.335, 3.365, 2.375, all P< 0.05). Compared with that in WT+CLP group, the 7-day survival rate of mice increased in TG+CLP group (60.0% vs 33.3%, χ(2)=8.227, P= 0.004), and the cardiac function improved ( t= 2.337, P= 0.019), but the serum levels of CK-MB and cTnI and the levels of ROS and MDA in myocardium in TG+CLP group reduced significantly ( t= 2.127, 3.347, 2.115, 2.224, P< 0.05). Conclusion: The expression of nucleolin is up-regulated in the myocardium of septic mice, and the overexpression of nucleolin can inhibit oxidative stress injury, attenuate the cardiac injury and dysfunction, and reduce mortality in septic mice.

Objective: To explore the change of transcription activity and expression of PPARbeta in the apoptotic HaCaT keratinocytes induced by TNF-alpha., Methods: HaCaT keratinocytes were exposed to different concentration TNF-alpha for 24 hours. Apoptotic morphological changes and percentage of apoptotic nuclei were assayed with Hoechst 33258 staining. Activities of Caspase-3 were analyzed with Caspase Colorimetric Assay Kit after HaCaT keratinocytes were exposed to TNF-alpha (10 and 20 ng/ml) for indicated durations. The expression of PPARbeta in HaCaT keratinocytes treated with TNF-alpha was observed by Western-blot and RT-PCR. Electrophoretic mobility shift assays demonstrated a impermanency increase in PPARbeta binding activity with DNA. Furthermore, luciferase assay system were employed to analyze PPARbeta transcription activity., Results: The apoptosis of HaCaT keratinocytes treated with different concentration TNF-alpha for 24 hours was increased by Hoechst 33258 stained, and fluorescent microscopy showed apoptotic cells with condensed chromatin. The nuclear apoptotic percentage were (12 +/- 3)%, (32 +/- 4)%, (57 +/- 5)%, respectively, in HaCaT keratinocytes exposed to TNF-alpha (5, 10, 20 ng/ml) for 24 hours. The activation of Caspase-3 were enhanced in HaCaT keratinocytes treated with TNF-alpha (10 or 20 ng/ml) for indicated durations (P < 0.01). The expression of PPARbeta protein significantly increased in HaCaT keratinocytes treated with TNF-alpha (10 ng/ml) for 12 and 24 hours. After exposure to different concentration of TNF-alpha for 24 hours, Western-blot analysis demonstrated to augment the expression of PPARbeta in HaCaT keratinocytes. RT-PCR testified the expression of PPARbeta mRNA is markedly increased in HaCaT keratinocytes treated with TNF-alpha (10,20 ng/ml) for 3 hours and 6 hours. PPARbeta-DNA binding was assessed by EMSA using a PPARbeta response element (PPRE) and nuclear extracts prepared from HaCaT keratinocytes treated for 30 minutes and 60 minutes with 10 ng/ml of TNF-alpha demerstrated TNF-alpha enhanced PPARbeta DNA binding activity. Furthermore, luciferase assay system obtained TNF-alpha increased PDK1 activity through an PPARbeta-dependent pathway., Conclusion: TNF-alpha could increase the expression and transcription activity of PPARbeta in HaCaT keratinocytes.