目的探讨ABI家族成员3结合蛋白(ABI family member 3-binding protein,ABI3BP)在血管紧张素Ⅱ(angiotensinⅡ,AngⅡ)诱导内皮祖细胞功能障碍中的作用及机制。方法为探讨ABI3BP在AngⅡ诱导内皮祖细胞功能障碍中的作用,将细胞分为4组,sh-N...目的探讨ABI家族成员3结合蛋白(ABI family member 3-binding protein,ABI3BP)在血管紧张素Ⅱ(angiotensinⅡ,AngⅡ)诱导内皮祖细胞功能障碍中的作用及机制。方法为探讨ABI3BP在AngⅡ诱导内皮祖细胞功能障碍中的作用,将细胞分为4组,sh-NC组[转染阴性对照短发夹RNA(LV-scramble-shRNA)+磷酸盐缓冲液(phosphate buffered saline,PBS)]、sh-ABI3BP组[转染ABI3BP shRNA(LV-ABI3BP-shRNA)+PBS]、sh-NC+AngⅡ组(LV-scramble-shRNA+AngⅡ)和sh-ABI3BP+AngⅡ组(LV-ABI3BP-shRNA+AngⅡ)。采用Transwell实验检测细胞迁移能力,黏附实验检测细胞黏附能力,Matrigel检测细胞成管能力,原位末端标记法检测细胞凋亡。Western blot检测整合素β1-黏着斑激酶(focal adhesion kinase,FAK)-P53信号通路变化情况。结果与sh-NC组比较,sh-NC+AngⅡ组迁移细胞数量、黏附细胞数量、小管形成数量显著降低,细胞凋亡率、整合素β1、磷酸化FAK(p-FAK)/FAK及P53蛋白表达显著增高,差异有统计学意义(P<0.05)。与sh-NC+AngⅡ组比较,sh-ABI3BP+AngⅡ组迁移细胞数量[(88.67±8.33)个vs(62.33±7.37)个]、黏附细胞数量[(104.33±6.03)个vs(68.33±10.05)个]、小管形成数量[(36.33±3.21)个vs(19.33±3.06)个]显著增高,细胞凋亡率、整合素β1、p-FAK/FAK及P53蛋白表达水平显著降低,差异有统计学意义(P<0.05)。结论AngⅡ可上调ABI3BP表达,敲低ABI3BP基因表达可改善AngⅡ诱导的内皮祖细胞功能障碍,其机制可能与抑制整合素β1-FAK-P53信号通路有关。展开更多
Balsam fir is an important Christmas tree species, especially in eastern Canada. The natural Christmas tree industry faces a challenge in postharvest needle abscission. Though there have been many studies describing t...Balsam fir is an important Christmas tree species, especially in eastern Canada. The natural Christmas tree industry faces a challenge in postharvest needle abscission. Though there have been many studies describing the physiological triggers and consequences in postharvest balsam fir, there have been no studies describing morphological or ultrastructural changes. Therefore, the objective of this study was to examine changes in stomata and chloroplast of postharvest needles. Branches were collected from low and high needle abscission resistance balsam fir genotypes, placed in water, and displayed in typical household conditions for 11 weeks. Needle abscission, chlorophyll fluorescence, and water uptake were monitored throughout. Needles stomata and chloroplasts were examined under a scanning and transmission electron microscope, respectively, each week. All branches had increased abscission, decreased chlorophyll fluorescence, and decreased water uptake over time. Needle surfaces accumulated fungal hyphae, especially in stomata. Chloroplasts demonstrated some dysfunction within two weeks, with notable decreases in chloroplast starch and increases in plastoglobulins. Within several weeks thylakoid membranes had been dismantled as chloroplasts transformed into gerontoplasts. All biophysical and structural changes were more pronounced in low needle abscission resistant genotypes. This research identifies a potential role for needle fungi in postharvest needle abscission and confirms the postharvest senescence of chloroplasts. Though it was previously speculated that chloroplasts must senesce postharvest, this study identifies how quickly this process occurs and that it occurs at different rates in contrasting genotypes.展开更多
文摘Balsam fir is an important Christmas tree species, especially in eastern Canada. The natural Christmas tree industry faces a challenge in postharvest needle abscission. Though there have been many studies describing the physiological triggers and consequences in postharvest balsam fir, there have been no studies describing morphological or ultrastructural changes. Therefore, the objective of this study was to examine changes in stomata and chloroplast of postharvest needles. Branches were collected from low and high needle abscission resistance balsam fir genotypes, placed in water, and displayed in typical household conditions for 11 weeks. Needle abscission, chlorophyll fluorescence, and water uptake were monitored throughout. Needles stomata and chloroplasts were examined under a scanning and transmission electron microscope, respectively, each week. All branches had increased abscission, decreased chlorophyll fluorescence, and decreased water uptake over time. Needle surfaces accumulated fungal hyphae, especially in stomata. Chloroplasts demonstrated some dysfunction within two weeks, with notable decreases in chloroplast starch and increases in plastoglobulins. Within several weeks thylakoid membranes had been dismantled as chloroplasts transformed into gerontoplasts. All biophysical and structural changes were more pronounced in low needle abscission resistant genotypes. This research identifies a potential role for needle fungi in postharvest needle abscission and confirms the postharvest senescence of chloroplasts. Though it was previously speculated that chloroplasts must senesce postharvest, this study identifies how quickly this process occurs and that it occurs at different rates in contrasting genotypes.
