OsBAK1 is involved in rice resistance to Xanthomonas oryzae pv. oryzae PXO99

Hualan Liao,Xiaorong Xiao,Xiuqiong Li,Yan Chen,Xiumei Fu,Daozhe Lin,Xiaolei Niu,Yinhua Chen,Chaozu He 한국식물생명공학회 2016 Plant biotechnology reports Vol.10 No.2

OsBAK1 gene belongs to a receptor like kinase gene family in rice and shares a highly conserved gene structure and sequence homology with Arabidopsis thaliana BAK1 gene. To investigate the role of OsBAK1 in rice immunity, the full-length cDNA of OsBAK1 was isolated by RT-PCR and the transgenic rice lines (over expression and RNA-interference lines) were generated using Agrobacterium-mediated transformation. The expression level of OsBAK1 was determined by q-PCR in overexpression and RNAi transgenic rice lines. Based on quantitative polymerase chain reaction (q-PCR) results, two overexpression lines and two RNAi lines were evaluated in bioassays for resistance to Xanthomonas oryzae pv. oryzae PXO99, the causal agent of rice bacterial blight disease. Pathogenicity bioassays showed overexpression OsBAK1 lines exhibited resistance to blight disease whereas OsBAK1 RNAi lines promoted susceptibility. Besides, OsBAK1 can complement the function of AtBAK1 in Arabidopsis bak1 protoplast, activating FRK1 expression, a marker gene in PTI signaling pathway, after treatment by flg22. Furthermore, the transcriptional level of OsBAK1 was induced significantly in rice by defense signaling molecules such as salicylic acid, jasmonic acid, and PXO99 inoculation. Our results illustrated OsBAK1 positively regulates plant defense against rice bacterium pathogen Xanthomonas oryzae pv. oryzae PXO99.

20(S)-protopanaxadiol promotes the migration, proliferation, and differentiation of neural stem cells by targeting GSK-3b in the Wnt/ GSK-3b/b-catenin pathway

Kaili Lin,Bin Liu,Sze-Lam Lim,Xiuqiong Fu,Stephen C.-W. Sze,Ken K.-L. Yung,Shiqing Zhang 고려인삼학회 2020 Journal of Ginseng Research Vol.44 No.3

Background: Active natural ingredients, especially small molecules, have recently received wide attention as modifiers used to treat neurodegenerative disease by promoting neurogenic regeneration of neural stem cell (NSC) in situ. 20(S)-protopanaxadiol (PPD), one of the bioactive ingredients in ginseng, possesses neuroprotective properties. However, the effect of PPD on NSC proliferation and differentiation and its mechanism of action are incompletely understood. Methods: In this study, we investigated the impact of PPD on NSC proliferation and neuronal lineage differentiation through activation of the Wnt/glycogen synthase kinase (GSK)-3b/b-catenin pathway. NSC migration and proliferation were investigated by neurosphere assay, Cell Counting Kit-8 assay, and EdU assay. NSC differentiation was analyzed by Western blot and immunofluorescence staining. Involvement of the Wnt/GSK3b/b-catenin pathway was examined by molecular simulation and Western blot and verified using gene transfection. Results: PPD significantly promoted neural migration and induced a significant increase in NSC proliferation in a time- and dose-dependent manner. Furthermore, a remarkable increase in antimicrotubule- associated protein 2 expression and decrease in nestin protein expression were induced by PPD. During the differentiation process, PPD targeted and stimulated the phosphorylation of GSK-3b at Ser9 and the active forms of b-catenin, resulting in activation of the Wnt/GSK-3b/b-catenin pathway. Transfection of NSCs with a constitutively active GSK-3b mutant at S9A significantly hampered the proliferation and neural differentiation mediated by PPD. Conclusion: PPD promotes NSC proliferation and neural differentiation in vitro via activation of the Wnt/ GSK-3b/b-catenin pathway by targeting GSK-3b, potentially having great significance for the treatment of neurodegenerative diseases.

20(S)-protopanaxadiol promotes the migration, proliferation, and differentiation of neural stem cells by targeting GSK-3β in the Wnt/GSK-3β/β-catenin pathway

Lin, Kaili,Liu, Bin,Lim, Sze-Lam,Fu, Xiuqiong,Sze, Stephen C.W.,Yung, Ken K.L.,Zhang, Shiqing The Korean Society of Ginseng 2020 Journal of Ginseng Research Vol.44 No.3

Background: Active natural ingredients, especially small molecules, have recently received wide attention as modifiers used to treat neurodegenerative disease by promoting neurogenic regeneration of neural stem cell (NSC) in situ. 20(S)-protopanaxadiol (PPD), one of the bioactive ingredients in ginseng, possesses neuroprotective properties. However, the effect of PPD on NSC proliferation and differentiation and its mechanism of action are incompletely understood. Methods: In this study, we investigated the impact of PPD on NSC proliferation and neuronal lineage differentiation through activation of the Wnt/glycogen synthase kinase (GSK)-3β/β-catenin pathway. NSC migration and proliferation were investigated by neurosphere assay, Cell Counting Kit-8 assay, and EdU assay. NSC differentiation was analyzed by Western blot and immunofluorescence staining. Involvement of the Wnt/GSK3β/β-catenin pathway was examined by molecular simulation and Western blot and verified using gene transfection. Results: PPD significantly promoted neural migration and induced a significant increase in NSC proliferation in a time- and dose-dependent manner. Furthermore, a remarkable increase in anti-microtubule-associated protein 2 expression and decrease in nestin protein expression were induced by PPD. During the differentiation process, PPD targeted and stimulated the phosphorylation of GSK-3β at Ser9 and the active forms of β-catenin, resulting in activation of the Wnt/GSK-3β/β-catenin pathway. Transfection of NSCs with a constitutively active GSK-3β mutant at S9A significantly hampered the proliferation and neural differentiation mediated by PPD. Conclusion: PPD promotes NSC proliferation and neural differentiation in vitro via activation of the Wnt/GSK-3β/β-catenin pathway by targeting GSK-3β, potentially having great significance for the treatment of neurodegenerative diseases.

Ginsenoside Rg3 in combination with artesunate overcomes sorafenib resistance in hepatoma cell and mouse models

Ying-Jie Chen,Jia-Ying Wu,Yu-Yi Deng,Ying Wu,Xiao-Qi Wang,Amy Sze-man Li,Lut Yi Wong,Xiuqiong Fu,Zhi-Ling Yu,Chun Liang 고려인삼학회 2022 Journal of Ginseng Research Vol.46 No.3

Sorafenib is effective in treating hepatoma, but most patients develop resistance to it. STAT3signaling has been implicated in sorafenib resistance. Artesunate (ART) and 20(R)-ginsenoside Rg3 (Rg3)have anti-hepatoma effects and can inhibit STAT3 signaling in cancer cells. This study aimed to evaluatethe effects of Rg3 in combination with ART (Rg3-plus-ART) in overcoming sorafenib resistance, and toexamine the involvement of STAT3 signaling in these effects. Methods: Sorafenib-resistant HepG2 cells (HepG2-SR) were used to evaluate the in vitro anti-hepatomaeffects of Rg3-plus-ART. A HepG2-SR hepatoma-bearing BALB/c-nu/nu mouse model was used to assessthe in vivo anti-hepatoma effects of Rg3-plus-ART. CCK-8 assays and Annexin V-FITC/PI double stainingwere used to examine cell proliferation and apoptosis, respectively. Immunoblotting was employed toexamine protein levels. ROS generation was examined by measuring DCF-DA fluorescence. Results: Rg3-plus-ART synergistically reduced viability of, and evoked apoptosis in HepG2-SR cells, andsuppressed HepG2-SR tumor growth in mice. Mechanistic studies revealed that Rg3-plus-ART inhibitedactivation/phosphorylation of Src and STAT3 in HepG2-SR cultures and tumors. The combination alsodecreased the STAT3 nuclear level and induced ROS production in HepG2-SR cultures. Furthermore, overactivation of STAT3 or removal of ROS diminished the anti-proliferative effects of Rg3-plus-ART, andremoval of ROS diminished Rg3-plus-ART's inhibitory effects on STAT3 activation in HepG2-SR cells. Conclusions: Rg3-plus-ART overcomes sorafenib resistance in experimental models, and inhibition of Src/STAT3 signaling and modulation of ROS/STAT3 signaling contribute to the underlying mechanisms. Thisstudy provides a pharmacological basis for developing Rg3-plus-ART into a novel modality for treatingsorafenib-resistant hepatoma.