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AIM:To study the effects of adiponectin on H 2 O2-induced cell injury and tau hyperphosphorylation in human neuroblastoma SH-SY5Y cells.METHODS:Cell viability was determined by MTT assay .H2 O2-induced cell in-jury and morphological changes in the SH-SY5Y cells with or without adiponectin treatment were observed .The level of tau phosphorylation as well as the activities of protein phosphatase 2A (PP2A) and of glycogen synthase kinase-3β(GSK-3β) were examined by Western blotting . RESULTS: Adiponectin significantly attenuated H 2 O2-induced cell injury (P<0.01).Adiponectin upregulated the activity of PP2A and decreased phosphorylation levels of tau under the stimula-tion with H2O2(P<0.01).Okadaic acid, a specific inhibitor of PP2A, blocked the protective effects of adiponectin (P<0.01).Adiponectin increased the phosphorylation level of GSK-3βat Ser9 site under H2O2stimulation (P<0.01).CON-CLUSION:Adiponectin protects SH-SY5Y cells against H2O2-induced cell injury and decreases tau hyperphosphorylation by activating PP2A and inactivating GSK-3β.
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AIM: To investigate the role of ubiquitin-proteasome system ( UPS) in adipocyte differentiation. METHODS:Differentiation of 3T3-L1 preadipocytes into adipocytes was induced by treatment with insulin, 3-isobutyl-1-methylxanthine and dexamethasone.Western blot and immunoprecipitation were performed to detect the protein abundances and association, respectively.Oil red O staining was used to determine the intracellular lipid of 3T3-L1 adipocytes.The levels of mRNA were measured by reverse transcription polymerase chain reaction ( RT-PCR) .RESULTS:UPS inhibitor bortezomib (BZM) suppressed the differentiation of 3T3-L1 pre-adipocytes, evidenced by reduced intracellular content of triglyceride, and decreased mRNA expression of adipogenic marker proteins such as adiponectin and adipocyte protein 2.In contrast, administration of sildenafil (SDN), an activator of protein kinase G which was also found to activate UPS, promo-ted adipocyte differentiation.In addition, BZM treatment decreased the expression of heat shock protein 90 (HSP90) and peroxisome proliferator-activated receptor gamma ( PPARγ) in the soluble fraction and reduced association of HSP90 and PPARγ.Furthermore, HSP90-specific N-terminal inhibitor geldanamic mitigated SDN-induced increase in PPARγlevel and 3T3-L1 cell differentiation.CONCLUSION:UPS modulates HSP90-dependent PPARγstability, thus leading to pro-motion of adipocyte differentiation.
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AIM:To investigate the potential effect of all-trans retinoic acid (ATRA) on the proliferation of human breast cancer MCF-7 cells and its underlying mechanism.METHODS:Human breast cancer MCF-7 cells were in-cubated in DMEM supplemented with 10%fetal bovine serum and 1%penicillin/streptomycin.Western blot was performed to detect the protein expression and its phosphorylation.MTT assay and bromodeoxyuridine ( BrdU) incorporation, and TUNEL staining were carried out to determine the cell proliferation and apoptosis, respectively.Lentivirus carrying shRNA sequences targeting the gene of docking protein 1 ( DOK1 ) was used to silence DOK1 expression.The activity of peroxi-some proliferator-activated receptor gamma ( PPARγ) was measured using a PPARγtranscription factor assay kit.RE-SULTS:ATRA treatment suppressed the proliferation and promoted the apoptosis of MCF-7 cells.ATRA was also found to induce DOK1 expression in a time-dependent manner.Silence of DOK1 mitigated anti-cancer effect of ATRA evidenced by recovered the cell proliferation and reduced the cell apoptosis.In addition, DOK1 knockdown inhibited PPARγexpression and activity.Furthermore, inhibition of PPARγwith its specific inhibitor GW9662 attenuated impacts of ATRA on the cell proliferation and apoptosis.CONCLUSION: ATRA suppresses MCF-7 cell survival through inhibiting cell proliferation and promoting cell apoptosis, which is mediated by DOK1-activated PPARγ.
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College education plays a significant role in cultivating the innovative talents in the national education system.It is an important way to make a person innovative By carrying out the education reform of scientific research among undergraduates.Much to my honor,I,having participated in all the process of the project application and experimental research supported by the funds,the project application of undergraduate scientific research,WHU,2006.I,attempt to make an argument about significance and superiority of the medical undergraduates taking part in the scientific research.Moreover,I would like to put forward some principles for those who are about to participate in this similar kind of activity.
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Objective To study the effect of interventional treatment of iliac and femoral vein stenosis concomitant with deep venous thrombosis. Method Fifty-three patients were divided into 5 groups. In group A after placing into inferior vena cava a filter,11 patients adopted Amplatz Trombectomy Device for thrombolysis or ORSIS thrombolysis and persistent thrombolysis through popliteal vein. In group B thrombus was taken out through guiding catheter and then persistent thrombolysis through popliteal vein after placing into inferior vena cava filters in 9 cases. In group C 13 patients adopted persistent thrombolysis through femoral arteries. In group D 8 patients received persistent thrombolysis through popliteal vein. In group E persistent thrombolysis through foot veins was carried out in 12 patients. Seventeen patients received implanted stents and balloon-expansion in iliac and femoral veins. Results Symptoms disappeared in 26 patients(49.0%), significantly improved in 21 patients (39.6%), improved in 3 patients (5.7%), did not improve in 3 patients (5.7%), respectively. The repatency of iliac and femoral vein was achieved in more than 80% of the 17 patients. Complications developed in 3 cases in the course of thrombolysis. Conclusion The effect of mechanical removal of thrombus, persistent thrombolysis through catheter and transluminal angioplasty is safe and satisfactory.