p53＇s apoptotic program consists of transcription-dependent and transcription-independent pathways. In the latter, physical interactions between mitochondrial p53 and anti- and pro-apoptotic members of the Bcl2 famil...p53＇s apoptotic program consists of transcription-dependent and transcription-independent pathways. In the latter, physical interactions between mitochondrial p53 and anti- and pro-apoptotic members of the Bcl2 family of mitochondrial permeability regulators are central. Using isogenic cell systems with defined deficiencies, we characterize in detail how mitochondrial p53 contributes to mitochondrial permeabilization, to what extent its action depends on other key Bcl2 family members and define its release activity. We show that mitochondrial p53 is highly efficient in inducing the release of soluble and insoluble apoptogenic factors by severely disrupting outer and inner mitochondrial membrane integrity. This action is associated with wild-type p53-induced oligomerization of Bax, Bak and VDAC and the formation of a stress-induced endogenous complex between p53 and cyclophilin D, normally located at the inner membrane. Tumor-derived p53 mutants are deficient in activating the Bax/Bak lipid pore. These actions are independent of Puma and Bax. Importantly, the latter distinguishes the mitochondrial from the cytosolic p53 death pathway.展开更多
AIM: To investigate the regulation of Eaf2 protein in mouse lens cells apoptosis induced by ultraviolet (UV) radiation. METHODS: An eye of Eaf2 gene knockout mice or normal control mice was exposed to UV radiation, an...AIM: To investigate the regulation of Eaf2 protein in mouse lens cells apoptosis induced by ultraviolet (UV) radiation. METHODS: An eye of Eaf2 gene knockout mice or normal control mice was exposed to UV radiation, and the other one was non-exposed. All of lenses were analyzed by TUNEL and caspase 3 activity assays to determine the difference of the apoptosis induced by UV radiation. In addition, exposed and non-exposed lenses were analyzed by quantified p53 expression and real-time reverse transcription-polymerase chain reaction (RT-PCR) of Bax, Bid, Apaf-1, Puma and Noxa, to compare Eaf2 gene knockout mice and normal control mice. RESULTS: UV radiation caused apoptosis of lens cells in normal control mice and Eaf2 knockout mice. Activity of caspase 3 was significantly higher in normal control mice than Eaf2 knockout mice. Expression of p53 protein was significantly higher in lenses exposed to UV radiation than nonexposed lenses, but was similar between Eaf2 gene knockout mice and normal control mice in the same UV condition. After exposing to UV radiation, the analysis of real-time RT-PCR demonstrated that mRNA levels of Puma and Noxa were significantly higher in lenses of normal control mice than Eaf2 gene knockout mice, and that mRNA levels of Bax, Bid and Apaf-1 were not significantly different between gene knockout mice and normal control mice. CONCLUSION: Eaf2 increases lens cells apoptosis induced by ultraviolet radiation. And Eaf2 up-regulates expression of the Puma and the Noxa to act on lens cells apoptosis after UV radiation.展开更多
P53正向细胞凋亡调控因子(P53 upregulated modulator of apoptosis,PUMA)是Bcl-2家族唯BH3结构域亚家族成员,位于线粒体内,可被多种损伤因素诱导激活。PUMA通过BH3结构域与Bcl-2样抗凋亡蛋白结合后发挥其促凋亡作用。PUMA抑制剂模拟蛋...P53正向细胞凋亡调控因子(P53 upregulated modulator of apoptosis,PUMA)是Bcl-2家族唯BH3结构域亚家族成员,位于线粒体内,可被多种损伤因素诱导激活。PUMA通过BH3结构域与Bcl-2样抗凋亡蛋白结合后发挥其促凋亡作用。PUMA抑制剂模拟蛋白间的结合作用,阻碍PUMA与Bcl-2样蛋白结合,凋亡被抑制。在体内,依小鼠肝脏缺血、再灌注时间不同,损伤情况各异。损伤较轻时,PUMA表达升高,PUMA抑制剂能够保护肝脏抵抗损伤;当损伤较严重时,PUMA表达升高不明显,PUMA抑制剂的保护作用也不明显。综合上述,在一定程度损伤的条件下,PUMA抑制剂可以有效地保护肝脏,减轻损伤。展开更多
Background Methanesulfonic acid sodium salt （Dipyrone）, an antipyretic and analgesic drug, has been demonstrated to improve cerebral ischemia through the inhibition of mitochondrial cell death cascades. The aim of t...Background Methanesulfonic acid sodium salt （Dipyrone）, an antipyretic and analgesic drug, has been demonstrated to improve cerebral ischemia through the inhibition of mitochondrial cell death cascades. The aim of this study was to evaluate the potential photoprotective activity of methanesulfonic acid sodium salt in a model of light-induced retinopathy. Methods One hundred mice were assigned randomly into vehicle （V）, methanesulfonic acid sodium salt （D）, light damage model plus vehicle （MV） and light damage model plus methanesulfonic acid sodium salt （MD） groups （n=25 each）. In the MD group, methanesulfonic acid sodium salt （100 mg/kg） was administered by intraperitoneal injection 30 minutes before light exposure. Twenty-four hours after light exposure, hematoxylin and eosin staining and transmission electron microscopy （TEM） were used for histological evaluation. The thickness of the outer plus inner-segment and outer nuclear layer was measured on sections parallel to the vertical meridian of the eye at a distance of 1000 I^m from the optic nerve. Electroretinography （ERG） test was performed to assess the functional change. The morphology of mitochondria was also revealed by TEM. Finally, the expression of cytochrome c （CytC） and the relative apoptotic proteins were detected by Western blotting, and the interaction between mitochondrial proteins was investigated by co-immunoprecipitation. Results The photoreceptor inner and outer segments of the MV group were significantly disorganized than the MD group. The thicknesses of the outer plus inner-segment layers and the outer nuclear layer, and the amplitudes of the a and b waves of the scotopic ERG response markedly decreased in the MV group compared to those in the MD group （P 〈0.05）. TEM examination revealed that the mitochondria of the MV group were distinctly swollen and contained disrupted cristae. In contrast, the morphology of mitochondria in the MD group was unaffected. Western blotting analysis showed that CytC, apoptosis proteinase activating factor-1 （Apaf-1）, caspase 3, p53, p53-upregulated modulator of apoptosis （PUMA）, Bax, and Bad were increased, whereas the anti-apoptotic proteins Bcl-2 and Bcl-XL were significantly decreased in the MV group than the MD group. Co-immunoprecipitation detection revealed that PUMA immunoreactivity precipitated by Bcl-XL decreased, whereas Bax immunoreactivity precipitated by Bcl-XL increased in the MD group compared to those in the MV group. Conclusion Methanesulfonic acid sodium salt is an effective photoprotective agent against light-induced retinopathy through the inhibition of CytC-mediated mitochondrial impairment.展开更多
文摘p53＇s apoptotic program consists of transcription-dependent and transcription-independent pathways. In the latter, physical interactions between mitochondrial p53 and anti- and pro-apoptotic members of the Bcl2 family of mitochondrial permeability regulators are central. Using isogenic cell systems with defined deficiencies, we characterize in detail how mitochondrial p53 contributes to mitochondrial permeabilization, to what extent its action depends on other key Bcl2 family members and define its release activity. We show that mitochondrial p53 is highly efficient in inducing the release of soluble and insoluble apoptogenic factors by severely disrupting outer and inner mitochondrial membrane integrity. This action is associated with wild-type p53-induced oligomerization of Bax, Bak and VDAC and the formation of a stress-induced endogenous complex between p53 and cyclophilin D, normally located at the inner membrane. Tumor-derived p53 mutants are deficient in activating the Bax/Bak lipid pore. These actions are independent of Puma and Bax. Importantly, the latter distinguishes the mitochondrial from the cytosolic p53 death pathway.
文摘AIM: To investigate the regulation of Eaf2 protein in mouse lens cells apoptosis induced by ultraviolet (UV) radiation. METHODS: An eye of Eaf2 gene knockout mice or normal control mice was exposed to UV radiation, and the other one was non-exposed. All of lenses were analyzed by TUNEL and caspase 3 activity assays to determine the difference of the apoptosis induced by UV radiation. In addition, exposed and non-exposed lenses were analyzed by quantified p53 expression and real-time reverse transcription-polymerase chain reaction (RT-PCR) of Bax, Bid, Apaf-1, Puma and Noxa, to compare Eaf2 gene knockout mice and normal control mice. RESULTS: UV radiation caused apoptosis of lens cells in normal control mice and Eaf2 knockout mice. Activity of caspase 3 was significantly higher in normal control mice than Eaf2 knockout mice. Expression of p53 protein was significantly higher in lenses exposed to UV radiation than nonexposed lenses, but was similar between Eaf2 gene knockout mice and normal control mice in the same UV condition. After exposing to UV radiation, the analysis of real-time RT-PCR demonstrated that mRNA levels of Puma and Noxa were significantly higher in lenses of normal control mice than Eaf2 gene knockout mice, and that mRNA levels of Bax, Bid and Apaf-1 were not significantly different between gene knockout mice and normal control mice. CONCLUSION: Eaf2 increases lens cells apoptosis induced by ultraviolet radiation. And Eaf2 up-regulates expression of the Puma and the Noxa to act on lens cells apoptosis after UV radiation.
文摘P53正向细胞凋亡调控因子(P53 upregulated modulator of apoptosis,PUMA)是Bcl-2家族唯BH3结构域亚家族成员,位于线粒体内,可被多种损伤因素诱导激活。PUMA通过BH3结构域与Bcl-2样抗凋亡蛋白结合后发挥其促凋亡作用。PUMA抑制剂模拟蛋白间的结合作用,阻碍PUMA与Bcl-2样蛋白结合,凋亡被抑制。在体内,依小鼠肝脏缺血、再灌注时间不同,损伤情况各异。损伤较轻时,PUMA表达升高,PUMA抑制剂能够保护肝脏抵抗损伤;当损伤较严重时,PUMA表达升高不明显,PUMA抑制剂的保护作用也不明显。综合上述,在一定程度损伤的条件下,PUMA抑制剂可以有效地保护肝脏,减轻损伤。
文摘Background Methanesulfonic acid sodium salt （Dipyrone）, an antipyretic and analgesic drug, has been demonstrated to improve cerebral ischemia through the inhibition of mitochondrial cell death cascades. The aim of this study was to evaluate the potential photoprotective activity of methanesulfonic acid sodium salt in a model of light-induced retinopathy. Methods One hundred mice were assigned randomly into vehicle （V）, methanesulfonic acid sodium salt （D）, light damage model plus vehicle （MV） and light damage model plus methanesulfonic acid sodium salt （MD） groups （n=25 each）. In the MD group, methanesulfonic acid sodium salt （100 mg/kg） was administered by intraperitoneal injection 30 minutes before light exposure. Twenty-four hours after light exposure, hematoxylin and eosin staining and transmission electron microscopy （TEM） were used for histological evaluation. The thickness of the outer plus inner-segment and outer nuclear layer was measured on sections parallel to the vertical meridian of the eye at a distance of 1000 I^m from the optic nerve. Electroretinography （ERG） test was performed to assess the functional change. The morphology of mitochondria was also revealed by TEM. Finally, the expression of cytochrome c （CytC） and the relative apoptotic proteins were detected by Western blotting, and the interaction between mitochondrial proteins was investigated by co-immunoprecipitation. Results The photoreceptor inner and outer segments of the MV group were significantly disorganized than the MD group. The thicknesses of the outer plus inner-segment layers and the outer nuclear layer, and the amplitudes of the a and b waves of the scotopic ERG response markedly decreased in the MV group compared to those in the MD group （P 〈0.05）. TEM examination revealed that the mitochondria of the MV group were distinctly swollen and contained disrupted cristae. In contrast, the morphology of mitochondria in the MD group was unaffected. Western blotting analysis showed that CytC, apoptosis proteinase activating factor-1 （Apaf-1）, caspase 3, p53, p53-upregulated modulator of apoptosis （PUMA）, Bax, and Bad were increased, whereas the anti-apoptotic proteins Bcl-2 and Bcl-XL were significantly decreased in the MV group than the MD group. Co-immunoprecipitation detection revealed that PUMA immunoreactivity precipitated by Bcl-XL decreased, whereas Bax immunoreactivity precipitated by Bcl-XL increased in the MD group compared to those in the MV group. Conclusion Methanesulfonic acid sodium salt is an effective photoprotective agent against light-induced retinopathy through the inhibition of CytC-mediated mitochondrial impairment.
