Mechanism of Synergetic Growth of Flexibility and Strength of Biomimetic Nanocomposite Fibre

Xiangyu Duan,Pan Li,Jingyu Ouyang,Zichen Gao,Jiaxin Liu,Jie Wang,Zhigang Xia,Weilin Xu 한국섬유공학회 2022 Fibers and polymers Vol.23 No.3

Nanocomposites with carbon nanotubes (CNTs) can combine the stiffness and multi-functionality of carbonnanotubes with the advantages of high toughness and processability of polymers giving rise to properties different from thatof general composites. However, when the content of CNTs increases gradually, the flexibility of the composite fibre canreduce. In this paper, we propose a simple method of softening the composite fibre via dimensional helical deformation offibre inner macromolecule bundles to avoid the deterioration of fibre flexibility. The theoretical simulations were conductedto predict proper helical deformations of the single fibre to increase fibre softness, followed by practical softening of thepolyvinylidene difluoride (PVDF)/CNTs composite by tensional twisting of the single fibres. The fibres with and withouttensional twisting were tested by Fourier-transformed infrared spectroscopy, scanning electron microscopy, X-ray diffractionand mechanical drawing. Results showed the reinforcement of the PVDF/multi-walled CNTs composite fibres (tensilestrength enhanced from 4.71 to 5.19 cN/dtex) with an evident softness reduction (initial modulus increased from 16.8 to20.52 cN/dtex) as the CNTs content increased from 0 to 1.5 wt%. After the tensional twisting, the initial modulus of thecomposite fibre was reduced by 62.5 % while the fibre strength remained reinforced because biomimetic helix formationimproved the internal structure deformation ability of the fibre.

3',4',5',5,7-Pentamethoxyflavone Sensitizes Cisplatin-Resistant A549 Cells to Cisplatin by Inhibition of Nrf2 Pathway

Xiangyu Hou,Xupeng Bai,Xiaoli Gou,Hang Zeng,Chen Xia,Wei Zhuang,Xinmeng Chen,Zhongxiang Zhao,Min Huang,Jing Jin 한국분자세포생물학회 2015 Molecules and cells Vol.38 No.5

Nuclear factor erythroid 2-related factor 2 (Nrf2) is an important redox-sensitive transcription factor that regulates the expression of several cytoprotective genes. More recently, genetic analyses of human tumors have indicated that Nrf2 may cause resistance to chemotherapy. In this study, we found that the expression levels of Nrf2 and its target genes GCLC, HO-1, NQO1 were significantly higher in cisplatinresistant A549 (A549/CDDP) cells than those in A549 cells, and this resistance was partially reversed by Nrf2 siRNA. 3',4',5',5,7-Pentamethoxyflavone (PMF), a natural flavonoid extracted from Rutaceae plants, sensitized A549/CDDP to CDDP and substantially induced apoptosis compared with that of CDDP alone treated group, and this reversal effect decreased when Nrf2 was downregulated by siRNA. Mechanistically, PMF reduced Nrf2 expression leading to a reduction of Nrf2 downstream genes, and in contrast, this effect was decreased by blocking Nrf2 with siRNA. Taken together, these results demonstrated that PMF could be used as an effective adjuvant sensitizer to increase the efficacy of chemotherapeutic drugs by downregulating Nrf2 signaling pathway.

3',4',5',5,7-Pentamethoxyflavone Sensitizes Cisplatin-Resistant A549 Cells to Cisplatin by Inhibition of Nrf2 Pathway

Hou, Xiangyu,Bai, Xupeng,Gou, Xiaoli,Zeng, Hang,Xia, Chen,Zhuang, Wei,Chen, Xinmeng,Zhao, Zhongxiang,Huang, Min,Jin, Jing Korean Society for Molecular and Cellular Biology 2015 Molecules and cells Vol.38 No.5

Nuclear factor erythroid 2-related factor 2 (Nrf2) is an important redox-sensitive transcription factor that regulates the expression of several cytoprotective genes. More recently, genetic analyses of human tumors have indicated that Nrf2 may cause resistance to chemotherapy. In this study, we found that the expression levels of Nrf2 and its target genes GCLC, HO-1, NQO1 were significantly higher in cisplatin-resistant A549 (A549/CDDP) cells than those in A549 cells, and this resistance was partially reversed by Nrf2 siRNA. 3,4,5,5,7-Pentamethoxyflavone (PMF), a natural flavon extracted from Rutaceae plants, sensitized A549/CDDP to CDDP and substantially induced apoptosis compared with that of CDDP alone treated group, and this reversal effect decreased when Nrf2 was downregulated by siRNA. Mechanistically, PMF reduced Nrf2 expression leading to a reduction of Nrf2 downstream genes, and in contrast, this effect was decreased by blocking Nrf2 with siRNA. Taken together, these results demonstrated that PMF could be used as an effective adjuvant sensitizer to increase the efficacy of chemotherapeutic drugs by downregulating Nrf2 signaling pathway.

Meta-analysis of the effect of melatonin application on abiotic stress tolerance in plants

Yang Xiaoxiao,Ren Jianhong,Li Juanjuan,Lin Xinyue,Xia Xiangyu,Yan Wenjie,Zhang Yuxin,Deng Xiping,Ke Qingbo 한국식물생명공학회 2023 Plant biotechnology reports Vol.17 No.1

Melatonin is a hormone-like substance that promotes plant growth and development and alleviates stress levels. Although the physiological roles of melatonin and the underlying mechanisms have been qualitatively reviewed in plants, we do not fully understand when and how to apply melatonin to maximize its benefits. Here, we performed a meta-analysis to quantitatively evaluate the effect of melatonin on abiotic stress tolerance in plants and to determine the number of parameters modulated by melatonin. Melatonin significantly alleviated the growth inhibition induced by drought stress compared with other abiotic stresses, including salt, cold, heat, nitrogen deficit, and heavy metal toxicity, mainly owing to higher photosynthesis efficiency and antioxidant enzyme activity. Furthermore, melatonin modulated plant growth in a concentration-dependent manner and was more effective when applied to plants under moderate drought stress at an early stage via root irrigation. In addition, the impact of melatonin was greater in monocots than in dicots. Moreover, endogenous melatonin levels could be significantly increased via transgenic strategies. Among melatonin biosynthesis-related gene members, ASMT has tended to have the most influence on melatonin content in plants. In light of the rapidly developing genome editing technology, quantitatively increasing endogenous melatonin level in plant would be quite useful for moderating climatic conditions and combating desertification. Taken together, our results provide guidelines for melatonin application in crops plants for improving productivity under ongoing climate change.

Changes in plant anthocyanin levels in response to abiotic stresses: a meta-analysis

Yan Wenjie,Li Juanjuan,Lin Xinyue,Wang Lina,Yang Xiaoxiao,Xia Xiangyu,Zhang Yuxin,Yang Shaoyu,Li Hongbing,Deng Xiping,Ke Qingbo 한국식물생명공학회 2022 Plant biotechnology reports Vol.16 No.5

Anthocyanins are small molecule antioxidants that play important roles in plant response and resistance to abiotic stresses. Their levels increase when plants are exposed to abiotic stress. However, the general response patterns and magnitude of anthocyanin increase, and how they confer resistance to abiotic stresses, are difficult to evaluate because of the influence of experimental variables. In this study, changes in plant anthocyanin content under different abiotic stresses and the effect of anthocyanin overproduction on various physiological indicators were investigated through meta-analysis derived from 1039 datasets of 102 studies. Results showed that among the different stress types, heavy metals, especially copper (Cu) and mercury (Hg), induced the most significant synthesis of anthocyanins. Among the different types of drought treatments, mannitol caused anthocyanin content in plants to increase by 2.4-fold, which was more significant than that of polyethylene glycol and natural drought. Furthermore, UV stress led plant anthocyanins to increase 1.3-fold in C4 plants, which was higher than that in C3 plants. In addition, anthocyanins increased the most when the applied stresses were low and moderate, and of short duration. Moreover, plants overexpressing genes encoding MYB transcription factors increased anthocyanin content by 5.8-fold and significantly improved plant stress tolerance. Among the 21 physiological indicators, glutathione and proline levels increased the most in transgenic plants overproducing anthocyanins when exposed to abiotic stress. Taken together, this meta-analysis indicates that anthocyanins enhance stress tolerance by improving the antioxidant, metal-chelating, and osmoregulatory abilities of the plant. The results presented here can help guide future applications of anthocyanins as plant growth regulators in dryland agriculture and breeding for plant stress tolerance.