Pentagalloylglucose induces autophagy and caspase-independent programmed deaths in human PC-3 and mouse TRAMP-C2 prostate cancer cells.

Hu, Hongbo,Chai, Yubo,Wang, Lei,Zhang, Jinhui,Lee, Hyo Jeong,Kim, Sung-Hoon,Lü,, Junxuan American Association for Cancer Research, Inc 2009 Molecular Cancer Therapeutics Vol.8 No.10

<P>Penta-1,2,3,4,6-O-galloyl-beta-d-glucose (PGG) suppresses the in vivo growth of human DU145 and PC-3 prostate cancer xenografts in nude mice, suggesting potential utility as a prostate cancer chemotherapeutic or chemopreventive agent. Our earlier work implicates caspase-mediated apoptosis in DU145 and LNCaP prostate cancer cells as one mechanism for the anticancer activity. We show here that, in the more aggressive PC-3 prostate cancer cell line, PGG induced programmed cell deaths lacking the typical caspase-mediated apoptotic morphology and biochemical changes. In contrast, PGG induced patent features of autophagy, including formation of autophagosomes and lipid modification of light chain 3 after 48 hours of PGG exposure. The 'autophagic' responses were also observed in the murine TRAMP-C2 cells. Caspase inhibition exacerbated PGG-induced overall death. As for molecular changes, we observed a rapid inhibition of the phosphorylation of mammalian target of rapamycin-downstream targets S6K and 4EBP1 by PGG in PC-3 and TRAMP-C2 cells but not that of mammalian target of rapamycin itself, along with increased AKT phosphorylation. Whereas the inhibition of phosphatidylinositol 3-kinase increased PGG-induced apoptosis and autophagy, experiments with pharmacologic inducer or inhibitor of autophagy or by knocking down autophagy mediator Beclin-1 showed that autophagy provided survival signaling that suppressed caspase-mediated apoptosis. Knocking down of death receptor-interacting protein 1 kinase increased overall death without changing light chain 3-II or caspase activation, thus not supporting death receptor-interacting protein 1-necroptosis for PGG-induction of autophagy or other programmed cell death. Furthermore, PGG-treated PC-3 cells lost clonogenic ability. The induction by PGG of caspase-independent programmed cell death in aggressive prostate cancer cell lines supports testing its merit as a potential drug candidate for therapy of caspase-resistant recurrent prostate cancer.</P>

Endogenous leptin promotes autophagy in EBSS-induced PFCs

Deling Jiao,Zhen Yang,Lulu Wang,Binyue Hu,Jing Wang,Anyong Xu,Wenmin Cheng,Baoyu Jia,Yubo Qing,Hong-Ye Zhao,Hong-Jiang Wei 한국통합생물학회 2019 Animal cells and systems Vol.23 No.5

Leptin is an important adipokine and plays a vital role in animals. However, the role of leptin in the autophagic response of pig fibroblast cells (PFCs) has not been fully elucidated. In this study, we investigated the relationship between leptin and autophagy as well as underlying molecular basis. We found that PFCs treated with EBSS could secrete leptin, and the leptin concentration in the supernatant of leptin transgenic PFCs was higher than that of WT PFCs. We found an increase in LC3-II protein level and a decrease in p62 protein level in treated leptin transgenic PFCs compared with treated WT PFCs. Meanwhile, we observed an increase of autophagosomes by transmission electron microscopy and an enhancement of the accumulation of LC3 puncta in the cytoplasm of treated leptin transgenic PFCs, and these effects were further augmented by Baf A1 treatment. Furthermore, we detected the expression levels of 7 autophagy signaling pathway genes and 17 autophagy-related (ATG) genes by q-PCR. We found that between the two types of EBSS-treated cells 3 genes expression pattern were significantly different among the 7 autophagy signaling pathway genes and 8 genes expression pattern were significantly differernt among the ATG genes. These results indicated that leptin may promote autophagy and involving the downregulation of FOXO1 and LMNA genes via an unknown pathway which causes the upregulation of the 4 genes and the downregulation of 4 genes.

Interleaved High Step-Up Boost Converter

Ma, Penghui,Liang, Wenjuan,Chen, Hao,Zhang, Yubo,Hu, Xuefeng The Korean Institute of Power Electronics 2019 JOURNAL OF POWER ELECTRONICS Vol.19 No.3

Renewable energy based on photovoltaic systems is beginning to play an important role to supply power to remote areas all over the world. Owing to the lower output voltage of photovoltaic arrays, high gain DC-DC converters with a high efficiency are required in practice. This paper presents a novel interleaved DC-DC boost converter with a high voltage gain, where the input terminal is interlaced in parallel and the output terminal is staggered in series (IPOSB). The IPOSB configuration can reduce input current ripples because two inductors are interlaced in parallel. The double output capacitors are charged in staggered parallel and discharged in series for the load. Therefore, IPOSB can attain a high step-up conversion and a lower output voltage ripple. In addtion, the output voltage can be automatically divided by two capacitors, without the need for extra sharing control methods. At the same time, the voltage stress of the power devices is lowered. The inrush current problem of capacitors is restrained by the inductor when compared with high gain converters with a switching-capacitor structure. The working principle and steady-state characteristics of the converter are analyzed in detail. The correctness of the theoretical analysis is verified by experimental results.

Interleaved High Step-Up Boost Converter

Penghui Ma,Wenjuan Liang,Hao Chen,Yubo Zhang,Xuefeng Hu 전력전자학회 2019 JOURNAL OF POWER ELECTRONICS Vol.19 No.3

Renewable energy based on photovoltaic systems is beginning to play an important role to supply power to remote areas all over the world. Owing to the lower output voltage of photovoltaic arrays, high gain DC-DC converters with a high efficiency are required in practice. This paper presents a novel interleaved DC-DC boost converter with a high voltage gain, where the input terminal is interlaced in parallel and the output terminal is staggered in series (IPOSB). The IPOSB configuration can reduce input current ripples because two inductors are interlaced in parallel. The double output capacitors are charged in staggered parallel and discharged in series for the load. Therefore, IPOSB can attain a high step-up conversion and a lower output voltage ripple. In addtion, the output voltage can be automatically divided by two capacitors, without the need for extra sharing control methods. At the same time, the voltage stress of the power devices is lowered. The inrush current problem of capacitors is restrained by the inductor when compared with high gain converters with a switching-capacitor structure. The working principle and steady-state characteristics of the converter are analyzed in detail. The correctness of the theoretical analysis is verified by experimental results.

Strength Prediction of a Single Tooth Bound to Composite Pre-tightened Tooth Connection (PTTC) Joints based on Different Failure Criteria

Yifeng Gao,Fei Li,Qilin Zhao,Jiangang Gao,Yubo Hu 대한토목학회 2019 KSCE Journal of Civil Engineering Vol.23 No.8

A method capable to predict the strength of single tooth bound to composite pre-tightened tooth connection (PTTC) joints is presented. The proposed method uses four representative failure criteria: max-stress, Tsai-Hill, Tsai-Wu and Hashin. The characteristic length method is also used to obtain prediction strengths. Three types of experiments of single PTTC joints were conducted using the following variations: 1) tooth depth, 2) tooth length, and 3) pre-tightened force. The experimental results were compared with the two-dimensional failure envelope diagram calculated using the four representative failure criteria. The physical nature and the strength predictive ability of each criterion were investigated. The obtained results show that the shear failure mode of single PTTC joint was accurately predicted by all four failure criteria. However, the Tsai-Wu criterion when compared to Maximum Stress, Tsai-Hill and Hashin criteria, exhibits better accuracy regarding the prediction strength of single PTTC joints, this is due to the fact that the Tsai-Wu criterion reflects more accurately the increase in the interlaminar shear strength caused by the transverse compressive stress.