Curcumin inhibits preadipocyte differentiation by reducing CREB transcriptional activity / 中国药理学通报

Aim To investigate the effect of curcumin on differentiation of 3T3-L1 preadipocytes and its mechanism.Methods 3T3-L1 preadipocytes were treated with curcumin at different concentrations (10,20,40 μmol · L-1) and cell differentiation was synergistically induced.The proliferation of 3T3-L1 preadipocytes was detected by MTT assay.The lipid accumulation was detected by oil red O staining method,and the levels of CREB,C/EBPβ,C/EBPα,PPARγmRNA and protein in 3T3-L1 preadipocytes were detected by qRT-PCR and Western blot.Results MTT results showed that curcumin had a significant inhibitory effect on proliferation of 3T3-L1 preadipocytes in a dose-and time-dependent manner.Oil red O staining showed that curcumin inhibited the differentiation of 3T3-L1 preadipocytes in a dose-dependent manner.When 0,20,40 μmol · L-1 curcumin treatment of 3T3-L1 preadipocytes were performed,the levels of p-CREB,C/EBPβ,C/EBPα,PPARγ mRNA and protein significantly decreased with the increasing dose of curcumin (P ＜ 0.05).Conclusions Curcumin can effectively inhibit the proliferation and differentiation of 3T3-L1 preadipocytes.The mechanism may be that curcumin inhibits CREB transcriptional activity and inhibits the expression of C/EBPβ,C/EBPα and PPARγ.

Bone marrow stromal cells transfected with ciliary neurotrophic factor gene ameliorates the symptoms and inflammation in C57BL/6 mice with experimental allergic encephalomyelitis / 南方医科大学学报

<p><b>OBJECTIVE</b>To investigate the anti-inflammatory effect of bone marrow stromal cells (MSCs) transfected with recombinant adenovirus-mediated ciliary neurotrophic factor (CNTF) gene in C57BL/6 mice with experimental allergic encephalomyelitis (EAE).</p><p><b>METHODS</b>An adenovirus vector containing CNTF gene Ad-CNTF-IRES-GFP was constructed and transfected in the MSCs (MSC-CNTF). After examination of CNTF expression, the transfected cells were transplanted in C57BL/6 mice with MOG 35-55-induced EAE, which were monitored for the changes in the symptoms scores. The levels of tumor necrosis factor-alpha (TNF-alpha), inteferon-gamma (IFN-gamma), interleukin-12P35 (IL-12P35), and IL-10 in the peripheral blood of the mice were detected, and the number of MSC-CNTF cells in the spleen and spinal cord was counted. CD3+ T cell infiltration and TNF-alpha and IFN-gamma expressions in the lesions were also observed after the cell transplantation.</p><p><b>RESULTS</b>CNTF gene transfection resulted in significantly increased CNTF expression in the MSCs. The mice receiving MSC-CNTF transplantation exhibited significantly improved symptoms with shortened disease course and lessened disease severity. The cell transplantation also resulted in significantly decreased peripheral blood TNF-alpha levels, ameliorated CD3+T cell infiltrations and lowered TNF-alpha expression in the lesions, while the levels of IFN-gamma underwent no significant changes.</p><p><b>CONCLUSION</b>Transplantation of CNTF gene-transfected MSCs results in decreased peripheral blood TNF-alpha and IFN-gamma levels and reduced inflammatory cells, CD3-positive cells and TNF-alpha expression in the lesion of EAE, therefore providing better effect than MSCs in relieving the symptoms of EAE in mice.</p>

Reversing effect of brassinolide on multidrug resistance of-CCRF-VCR1000 cells and a preliminary investigation on its mechanisms / 药学学报

<p><b>AIM</b>To investigate the effect of brassinolide, a plant growth modulator, on multidrug resistance (MDR) of human T lymphoblastoid cell line CCRF-VCR 1000 which was obtained by progressively addition of vincristine (VCR) to sensitive CCRF-CEM cells, and to explore preliminarily the mechanism of reversing action.</p><p><b>METHODS</b>MTT method was used to detect the resistant factor of resistant cell line and the reversing fold after addition of brassinolide. The intracellular accumulation of rhodamine 123, a fluorescent dye transported by P-glycoprotein was detected by flow cytometry, the catalytic activity of topoisomerase II was assessed by Sulliven method to find the effect of brassinolide on resistance. The protein expression of p53 was measured using Western blotting in the sensitive cells and resistant cells to explore the effect of brassinolide.</p><p><b>RESULTS</b>The resistant factors of CCRF-VCR cells on adriamycin, VP-16 and VCR are respectively as 153.1, 55.9 and 8123.1 folds comparing to the sensitive cell line CCRF-CEM. After treatment of brassinolide under the concentration of 0.001 - 10.0 microg x mL(-1), the resistance of CCRF-VCR was reversed partly with the reversing folds respectively as 4.4 - 11.6. The intracellular accumulation of rhodamine 123 was significantly reduced in the resistant cells. After treatment of brassinolide, the accumulation increased, the level of fluorescent dye was situated between resistant cells and sensitive cells. No alteration of the catalytic activity of topoisomerase II was found among three groups. The level of protein expression of p53 in resistant cells was higher than that of sensitive cells. After brassinolide treatment, the expression of p53 in CCRF-VCR cells restored to the level of sensitive cells.</p><p><b>CONCLUSION</b>Brassinolide could effectively reverse the resistance of CCRF-VCR cells by inhibiting the effusion of drug transported by P-glucoprotein. To down regulate the abnormal expression of p53 maybe one of the mechanisms of reversing MDR for brassinolide.</p>

Inhibitive effects of recombinant adenovirus-mediated human endostatin on the growth of human hepatocellular carcinoma xenograft in nude mice / 中华肝脏病杂志

<p><b>OBJECTIVE</b>To investigate the inhibitive effect on the growth of hepatocellular carcinoma (HCC) xenografted in nude mice by adenovirus-mediated human endostatin gene.</p><p><b>METHODS</b>The expression efficiency of endostatin was examined after ECV-304 cells infected with Ad/hEndo by western blot. The hepatoma BEL-7402 cells were injected into Balb/c nude mice to detect the inhibition of Ad/hEndo on the growth of HCC xenografted in nude mice. The expression of endostatin mRNA in tumor tissue was analyzed with RT-PCR, and its distribution in vivo was also analyzed.</p><p><b>RESULTS</b>High level expression of endostatin achieved in infected ECV-304 cells by western blot. Ad/hEndo significantly inhibited the growth of xenografted BEL-7402 tumors (F=4.061, P<0.05). The intratumoral microvessel density (MVD) decreased significantly in the treated mice (6.88+/-1.08 vs 13.60+/-1.71, t=9.216, P<0.01). The expression of endostatin mRNA in tumor tissue was detected by RT-PCR in 3 days after administration intratumorally with Ad/hEndo and almost disappeared in 7 days. Endostatin mRNA was mainly located in tumor tissue with a higher concentration than that in heart, lung, spleen and liver after Ad/hEndo administration.</p><p><b>CONCLUSION</b>Adenovirus-mediated human endostatin gene can be expressed efficiently in vitro and in vivo, and significantly inhibit the growth of BEL-7402 xenografted tumors in nude mice.</p>