ABSTRACT
BACKGROUND@#All-trans retinoic acid (ATRA) promotes the osteogenic differentiation induced by bone morphogenetic protein 9 (BMP9), but the intrinsic relationship between BMP9 and ATRA keeps unknown. Herein, we investigated the effect of Cyp26b1, a critical enzyme of ATRA degradation, on the BMP9-induced osteogenic differentiation in mesenchymal stem cells (MSCs), and unveiled possible mechanism through which BMP9 regulates the expression of Cyp26b1. @*METHODS@#ATRA content was detected with ELISA and HPLC–MS/MS. PCR, Western blot, and histochemical staining were used to assay the osteogenic markers. Fetal limbs culture, cranial defect repair model, and micro–computed tomographic were used to evaluate the quality of bone formation. IP and ChIP assay were used to explore possible mechanism. @*RESULTS@#We found that the protein level of Cyp26b1 was increased with age, whereas the ATRA content decreased. The osteogenic markers induced by BMP9 were increased by inhibiting or silencing Cyp26b1 but reduced by exogenous Cyp26b1. The BMP9-induced bone formation was enhanced by inhibiting Cyp26b1. The cranial defect repair was promoted by BMP9, which was strengthened by silencing Cyp26b1 and reduced by exogenous Cyp26b1. Mechanically, Cyp26b1 was reduced by BMP9, which was enhanced by activating Wnt/b-catenin, and reduced by inhibiting this pathway. b-catenin interacts with Smad1/5/9, and both were recruited at the promoter of Cyp26b1. @*CONCLUSIONS@#Our findings suggested the BMP9-induced osteoblastic differentiation was mediated by activating retinoic acid signalling, viadown-regulating Cyp26b1. Meanwhile, Cyp26b1 may be a novel potential therapeutic target for the treatment of bone-related diseases or accelerating bone-tissue engineering.
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Aim To investigate the anti-proliferation effect of honokial on human colon cancer cells HCT116 and the possible mechanism. Methods Crystal stai-ning and flow cytometry assay were introduced to test the proliferation inhibitory and cell cycle arrested effect of honokial on HCT116 cells. Western blot was used to analyse the expression of PCNA and induction effect of apoptosis. Western blot and PCR assay were conducted to assess the change of BMP7. Via exogenous adenovi-ruses of BMP7 and its antibody combined with honoki-al,crystal violet staining and Western blot were used to analyse the effect on HCT116 cells. Results Honoki-al inhibited the growth of HCT116 in a time-and con- centration-dependent way,induced apoptosis and arres-ted at G2 phase; Western blot assay showed honokial up-regulated the level of PCNA and BMP7,and down-regulated the expression of Bcl-2; Western blot result also showed that exogenous adenoviruses of BMP7 en-hanced the effect of honokial on proliferation inhibition and apoptosis, while BMP7 antibody reversed such effects of honokial. Conclusion Honokial can inhibit the proliferation and induce apoptosis on HCT116 cells,which may be mediated by the up-regulation of BMP7.
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Aim To study the relationship between the anti-proliferative effect of resveratrol (Res) and BMP7 on human colon cancer cells and its possible molecular mechanism. Methods The proliferation of HCT116 cells was analyzed with cell proliferation inhibition assay, flow cytometry, Western blot and Annexin V-EGFP staining. CCK-8, PCR and Western blot assay were used to determine the effect of Res on BMP7 in HCT116 cells and the possible molecular mechanism underlying this process. Results Res inhibited the proliferation,arrested cell cycle at S phase and promo-ted apoptosis in HCT116 cells. Res increased the ex-pression of BMP7 mRNA and protein in HCT116 cells. Overexpression of BMP7 enhanced the anti-proliferative effect of Res on HCT116 cells and promoted the Res-induced apoptosis, whereas BMP7-specific antibody significantly attenuated these effects. Res exerted no apparent effect on the phosphorylation of Smad1/5/8, but decreased the phosphorylation of Akt1/2/3 sub-stantially in HCT116 cells. Overexpression of BMP7 enhanced the inhibitory effect of Res on phosphoryla-tion of Akt1/2/3, while BMP7 specific antibody re-duced this effect notably. Res markedly decreased the phosphorylation of PTEN, which could be boosted by BMP7,but attenuated by the BMP7 specific antibody. Conclusions Res can inhibit the proliferation and promote apoptosis of HCT116 cells,and the anti-canc-er activity of Res may be mediated by inactivating PI3K/Akt signaling through up-regulating BMP7 to de-crease the phosphorylation of PTEN partly.
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To investigate the protective effects of the total base from rhizoma coptis chinensis [CTB] and berberine [Ber] on neurodegeneration induced by aluminum overload in rats. The study took place in the Department of Pharmacology, Chongqing Medical University, Chongqing, China, between February 2005 and May 2007. Wistar rats were divided into control group, model group, Ber-treated group, CTB [55 mg/kg and 110 mg/kg]-treated group, and nimodipine-treated group [n=20]. A rat brain damage model was established via intragastric administration of 400 mg/kg element aluminum once a day, 5 days a week for 12 weeks. The CTB, Ber, and nimodipine were intragastrically administered 4 hours after each aluminum administration for 12 weeks. The morphological changes of the neurons of the rat hippocampus and the changes of rat learning and memory functions were observed. The superoxide dismutase [SOD], choline acetyltransferase [ChAT], acetylcholinesterase [AchE], and monoamine oxidase-B [MAO-B] activities and malondialdehyde [MDA] content, as well as the MAO-B expression in the rat brain were examined. The CTB, Ber, and nimodipine significantly improved the learning and memory ability impairment and hippocampal neuronal death. The CTB, Ber, and nimodipine also significantly blunted the decrease of SOD and ChAT activities, and the increase of MDA content, AchE activities, and MAO-B expressions and activity in the aluminum-overload rats. The CTB and Ber have protective effects on neurodegeneration induced by aluminum overload. The CTB [110 mg/kg] has more powerful neuroprotection than Ber
Subject(s)
Male , Animals, Laboratory , Berberine/pharmacology , Rhizome , Brain Injuries , Brain/drug effects , Aluminum , Neurodegenerative Diseases/veterinary , Rats, Wistar , Disease Models, Animal , Protective AgentsABSTRACT
<p><b>OBJECTIVE</b>To study the effects of total alkaloids(TA) from rhizoma Coptis chinensis on alcohol-induced gastric lesion in rats and the possible mechanisms.</p><p><b>METHOD</b>The experimental gastric damges were established by intragastric(ig) absolute ethanol, and possible protective effects of TA given orally previously were evaluated by following parameters: gastric damage indexes, gastric juice volume, acidity, and mucus quantity. The contents of NO, MDA, *OH, and SOD activity were also measured in gastric mucosa.</p><p><b>RESULT</b>TA showed significantly inhibitive effects on gastric damages induced by ig ethanol in a dose dependent manner. The effects of TA (120 mg x kg(-1)) were stronger than that of both cimitidine(70 mg x kg(-1)) and berberine(100 mg x kg(-1)), the quantity of later was equal to TA as calculated with berberine. TA significantly suppressed secretion of gastric acid caused by ethanol without clear influences on gastric juice volume and mucus secretion. TA obviously blunted ethanol-induced elevation of MDA and *OH, as well as decrease of NO level and SOD activity from gastric mucosa.</p><p><b>CONCLUSION</b>It is suggested that the TA is a potent protective agent against ethanol-induced gastric damages. The mechanism of actions may be related with inhibiting the secretion of gastric acid and blunting the increase of MDA and *OH, as well as the decrease of NO level and SOD activity from gastric mucus.</p>