BACKGROUND Monopolar spindle-binding protein 3B(MOB3B)functions as a signal transducer and altered MOB3B expression is associated with the development of human cancers.AIM To investigate the role of MOB3B in colorecta...BACKGROUND Monopolar spindle-binding protein 3B(MOB3B)functions as a signal transducer and altered MOB3B expression is associated with the development of human cancers.AIM To investigate the role of MOB3B in colorectal cancer(CRC).METHODS This study collected 102 CRC tissue samples for immunohistochemical detection of MOB3B expression for association with CRC prognosis.After overexpression and knockdown of MOB3B expression were induced in CRC cell lines,changes in cell viability,migration,invasion,and gene expression were assayed.Tumor cell autophagy was detected using transmission electron microscopy,while nude mouse xenograft experiments were performed to confirm the in-vitro results.RESULTS MOB3B expression was reduced in CRC vs normal tissues and loss of MOB3B expression was associated with poor CRC prognosis.Overexpression of MOB3B protein in vitro attenuated the cell viability as well as the migration and invasion capacities of CRC cells,whereas knockdown of MOB3B expression had the opposite effects in CRC cells.At the molecular level,microtubule-associated protein light chain 3 II/I expression was elevated,whereas the expression of matrix metalloproteinase(MMP)2,MMP9,sequestosome 1,and phosphorylated mechanistic target of rapamycin kinase(mTOR)was downregulated in MOB3B-overexpressing RKO cells.In contrast,the opposite results were observed in tumor cells with MOB3B knockdown.The nude mouse data confirmed these in-vitro findings,i.e.,MOB3B expression suppressed CRC cell xenograft growth,whereas knockdown of MOB3B expression promoted the growth of CRC cell xenografts.CONCLUSION Loss of MOB3B expression promotes CRC development and malignant behaviors,suggesting a potential tumor suppressive role of MOB3B in CRC by inhibition of mTOR/autophagy signaling.展开更多
The mammalian target of rapamycin （mTOR） pathway plays an important role in neuronal growth, proliferation and differentiation. To better understand the role of mTOR pathway involved in the induction of spinal cord ...The mammalian target of rapamycin （mTOR） pathway plays an important role in neuronal growth, proliferation and differentiation. To better understand the role of mTOR pathway involved in the induction of spinal cord injury, rat models of spinal cord injury were established by modified Allen＇s stall method and interfered for 7 days by intraperitoneal administration of mTOR activator adenosine triphosphate and mTOR kinase inhibitor rapamycin. At 1-4 weeks after spinal cord injury induction, the Basso, Beattie and Bresnahan locomotor rating scale was used to evaluate rat locomotor function, and immunohistochemical staining and western blot analysis were used to detect the expression of nestin （neural stem cell marker）, neuronal nuclei （neuronal marker）, neuron specific enolase, neurofilament protein 200 （axonal marker）, glial fibrillary acidic protein （astrocyte marker）, Akt, mTOR and signal transduction and activator of transcription 3 （STAT3）. Results showed that adenosine triphosphate-mediated Akt/mTOR/STAT3 pathway increased endogenous neural stem cells, induced neurogenesis and axonal growth, inhibited excessive astrogliosis and improved the locomotor function of rats with spinal cord injury.展开更多
As major fuels for the small intestinal mucosa,dietary amino acids(AA)are catabolized in the mitochondria and serve as sources of energy production.The present study was conducted to investigate AA metabolism that sup...As major fuels for the small intestinal mucosa,dietary amino acids(AA)are catabolized in the mitochondria and serve as sources of energy production.The present study was conducted to investigate AA metabolism that supply cell energy and the underlying signaling pathways in porcine enterocytes.Intestinal porcine epithelial cells(IPEC-J2)were treated with different concentrations of AA,inhibitor,or agonist of mammalian target of rapamycin complex 1(mTORCl)and adenosine monophosphate activated protein kinase(AMPK),and mitochondrial respiration was monitored.The results showed that AA treatments resulted in enhanced mitochondrial respiration,increased intracellular content of pyruvic acid and lactic acid,and increased hormone-sensitive lipase mRNA expression.Meanwhile,decreased citrate synthase,isocitrate dehydrogenase alpha,and carnitine palmitoyltransferase 1 mRNA expression were also observed.We found that AA treatments increased the protein levels of phosphorylated mammalian target of rapamycin(p-mTOR),phosphorylated-p70 ribosomal protein S6 kinase,and phosphorylated-4 E-binding protein 1.What is more,the protein levels of phosphorylated AMPKα(pAMPKa)and nicotinamide adenine dinucleotide(NAD)-dependent protein deacetylase sirtuin-1(SIRT1)were decreased by AA treatments in a time depending manner.Mitochondrial bioenergetics and the production of tricarboxylic acid cycle intermediates were decreased upon inhibition of mTORCl or AMPK.Moreover,AMPK activation could up-regulate the mRNA expressions of inhibitor of nuclear factor kappa-B kinase subunit beta(Ikbk(3),integrin-linked protein kinase(ILK),unconventional myosin-Ic(Myolc),ribosomal protein S6 kinase beta-2(RPS6 Kβ2),and vascular endothelial growth factor(VEGF)-β,which are downstream effectors of mammalian target of rapamycin(mTOR).The mRNA expressions of phosphatidylinositol 4,5-bisphosphate 3-kinase catalytic subunit delta isoform(PIK3 CD)and5’-AMP-activated protein kinase subunit gamma-1(PRKAG1),which are upstream regulators of mTOR,were also up-regulated by AMPK activation.On the other hand,AMPK activation also down-regulated FK506-binding protein 1 A(FKBP1 A),serine/threonine-protein phosphatase 2 A 55 kDa regulatory subunit B beta isoform,phosphatase and tensin homolog(PTEN),and unc-51 like autophagy activating kinase 1(Ulkl),which are up-stream regulators of mTORCl.Taken together,these data indicated that AA regulated cellular energy metabolism through mTOR and AMPK pathway in porcine enterocytes.These results demonstrated interactions of AMPK and mTORCl pathways in AA catabolism and energy metabolism in intestinal mucosa cells of piglets,and also provided reference for using AA to remedy human intestinal diseases.展开更多
目的：探讨慢性间歇性低氧对幼鼠脑区腺苷酸活化蛋白激酶（AMP-activated protein kinase,AMPK）通路的影响。方法：第一部分：将3～4周龄的SD幼鼠随机分为4组（n=8）：2周空气模拟对照（2AC）组、2周慢性间歇低氧（2IH）组、4周空气模...目的：探讨慢性间歇性低氧对幼鼠脑区腺苷酸活化蛋白激酶（AMP-activated protein kinase,AMPK）通路的影响。方法：第一部分：将3～4周龄的SD幼鼠随机分为4组（n=8）：2周空气模拟对照（2AC）组、2周慢性间歇低氧（2IH）组、4周空气模拟对照（4AC）组和4周慢性间歇低氧（4IH）组。第二部分：将3～4周龄的SD幼鼠随机分为2组（n=8）：4周慢性间歇性低氧组（4IH）和4周慢性间歇性低氧用药组（4IHI）。造模结束后行八臂迷宫测试,TUNEL法检测细胞凋亡,RT-qPCR法了解腺苷A2a受体的mRNA表达,Western blot法测定AMPK及哺乳动物雷帕霉素靶蛋白（mammalian target of rapamycin,mTOR）的磷酸化水平。结果：与对照组相比,2IH组和4IH组的参考记忆错误（RME）、工作记忆错误（WME）和总错误（TE）次数明显增加,差异有统计学显著性（P〈0.01）;4IH与2IH组比较,各项错误次数亦明显增加（P〈0.01）。4IHI组比4IH组RME、WME和TE次数减少,差异有统计学显著性（P〈0.01）。与对照组相比,2IH组和4IH组海马和前额皮层区的神经元凋亡增多,以4IH组凋亡明显（P〈0.05）;4IHI组凋亡较4IH组减少（P〈0.05）。2IH组和4IH组海马和前额皮层区腺苷受体A2a的mRNA和AMPK磷酸化蛋白的水平升高,mTOR磷酸化蛋白的水平下降,4IH组较2IH组改变明显（P〈0.05）。4IHI组较4IH组海马和前额皮层区的AMPK磷酸化蛋白水平下降,mTOR磷酸化蛋白水平升高（P〈0.05）。结论：慢性间歇性低氧诱导神经元凋亡,从而引起幼鼠学习记忆障碍,呈时间依赖性。慢性间歇性低氧上调腺苷A2a受体,激活海马和前额皮层区AMPK,抑制mTOR的活性,诱导神经元凋亡,进而影响幼鼠学习记忆能力。展开更多
基金Supported by National Natural Science Foundation of China,No.81760516Natural Science Foundation of Guangxi,China,No.2019GXNSFAA185030+1 种基金Self-Financed Scientific Research Projects of Guangxi Zhuang Autonomous Region Health and Family Planning Commission,China,No.Z20181003Guangxi Medical University Youth Science Fund Project,China,No.GXMUYSF202221.
文摘BACKGROUND Monopolar spindle-binding protein 3B(MOB3B)functions as a signal transducer and altered MOB3B expression is associated with the development of human cancers.AIM To investigate the role of MOB3B in colorectal cancer(CRC).METHODS This study collected 102 CRC tissue samples for immunohistochemical detection of MOB3B expression for association with CRC prognosis.After overexpression and knockdown of MOB3B expression were induced in CRC cell lines,changes in cell viability,migration,invasion,and gene expression were assayed.Tumor cell autophagy was detected using transmission electron microscopy,while nude mouse xenograft experiments were performed to confirm the in-vitro results.RESULTS MOB3B expression was reduced in CRC vs normal tissues and loss of MOB3B expression was associated with poor CRC prognosis.Overexpression of MOB3B protein in vitro attenuated the cell viability as well as the migration and invasion capacities of CRC cells,whereas knockdown of MOB3B expression had the opposite effects in CRC cells.At the molecular level,microtubule-associated protein light chain 3 II/I expression was elevated,whereas the expression of matrix metalloproteinase(MMP)2,MMP9,sequestosome 1,and phosphorylated mechanistic target of rapamycin kinase(mTOR)was downregulated in MOB3B-overexpressing RKO cells.In contrast,the opposite results were observed in tumor cells with MOB3B knockdown.The nude mouse data confirmed these in-vitro findings,i.e.,MOB3B expression suppressed CRC cell xenograft growth,whereas knockdown of MOB3B expression promoted the growth of CRC cell xenografts.CONCLUSION Loss of MOB3B expression promotes CRC development and malignant behaviors,suggesting a potential tumor suppressive role of MOB3B in CRC by inhibition of mTOR/autophagy signaling.
文摘The mammalian target of rapamycin （mTOR） pathway plays an important role in neuronal growth, proliferation and differentiation. To better understand the role of mTOR pathway involved in the induction of spinal cord injury, rat models of spinal cord injury were established by modified Allen＇s stall method and interfered for 7 days by intraperitoneal administration of mTOR activator adenosine triphosphate and mTOR kinase inhibitor rapamycin. At 1-4 weeks after spinal cord injury induction, the Basso, Beattie and Bresnahan locomotor rating scale was used to evaluate rat locomotor function, and immunohistochemical staining and western blot analysis were used to detect the expression of nestin （neural stem cell marker）, neuronal nuclei （neuronal marker）, neuron specific enolase, neurofilament protein 200 （axonal marker）, glial fibrillary acidic protein （astrocyte marker）, Akt, mTOR and signal transduction and activator of transcription 3 （STAT3）. Results showed that adenosine triphosphate-mediated Akt/mTOR/STAT3 pathway increased endogenous neural stem cells, induced neurogenesis and axonal growth, inhibited excessive astrogliosis and improved the locomotor function of rats with spinal cord injury.
基金funded by the National Natural Science Foundation of China(31672433,31560640),ChinaSpecial fund for scientific innovation strategy-construction of high level Academy of Agriculture Science-the Outstanding Talents Training Program of Guangdong Academy of Agricultural Sciences(R2018PY-JC001),ChinaSpecial fund for scientific innovation strategy-construction of high level Academy Of Agriculture Science-The Talents Training Program Of Guangdong Academy Of Agricultural Sciences-Young Associate Researcher(R2018PY-QF001),China.
文摘As major fuels for the small intestinal mucosa,dietary amino acids(AA)are catabolized in the mitochondria and serve as sources of energy production.The present study was conducted to investigate AA metabolism that supply cell energy and the underlying signaling pathways in porcine enterocytes.Intestinal porcine epithelial cells(IPEC-J2)were treated with different concentrations of AA,inhibitor,or agonist of mammalian target of rapamycin complex 1(mTORCl)and adenosine monophosphate activated protein kinase(AMPK),and mitochondrial respiration was monitored.The results showed that AA treatments resulted in enhanced mitochondrial respiration,increased intracellular content of pyruvic acid and lactic acid,and increased hormone-sensitive lipase mRNA expression.Meanwhile,decreased citrate synthase,isocitrate dehydrogenase alpha,and carnitine palmitoyltransferase 1 mRNA expression were also observed.We found that AA treatments increased the protein levels of phosphorylated mammalian target of rapamycin(p-mTOR),phosphorylated-p70 ribosomal protein S6 kinase,and phosphorylated-4 E-binding protein 1.What is more,the protein levels of phosphorylated AMPKα(pAMPKa)and nicotinamide adenine dinucleotide(NAD)-dependent protein deacetylase sirtuin-1(SIRT1)were decreased by AA treatments in a time depending manner.Mitochondrial bioenergetics and the production of tricarboxylic acid cycle intermediates were decreased upon inhibition of mTORCl or AMPK.Moreover,AMPK activation could up-regulate the mRNA expressions of inhibitor of nuclear factor kappa-B kinase subunit beta(Ikbk(3),integrin-linked protein kinase(ILK),unconventional myosin-Ic(Myolc),ribosomal protein S6 kinase beta-2(RPS6 Kβ2),and vascular endothelial growth factor(VEGF)-β,which are downstream effectors of mammalian target of rapamycin(mTOR).The mRNA expressions of phosphatidylinositol 4,5-bisphosphate 3-kinase catalytic subunit delta isoform(PIK3 CD)and5’-AMP-activated protein kinase subunit gamma-1(PRKAG1),which are upstream regulators of mTOR,were also up-regulated by AMPK activation.On the other hand,AMPK activation also down-regulated FK506-binding protein 1 A(FKBP1 A),serine/threonine-protein phosphatase 2 A 55 kDa regulatory subunit B beta isoform,phosphatase and tensin homolog(PTEN),and unc-51 like autophagy activating kinase 1(Ulkl),which are up-stream regulators of mTORCl.Taken together,these data indicated that AA regulated cellular energy metabolism through mTOR and AMPK pathway in porcine enterocytes.These results demonstrated interactions of AMPK and mTORCl pathways in AA catabolism and energy metabolism in intestinal mucosa cells of piglets,and also provided reference for using AA to remedy human intestinal diseases.
文摘目的：探讨慢性间歇性低氧对幼鼠脑区腺苷酸活化蛋白激酶（AMP-activated protein kinase,AMPK）通路的影响。方法：第一部分：将3～4周龄的SD幼鼠随机分为4组（n=8）：2周空气模拟对照（2AC）组、2周慢性间歇低氧（2IH）组、4周空气模拟对照（4AC）组和4周慢性间歇低氧（4IH）组。第二部分：将3～4周龄的SD幼鼠随机分为2组（n=8）：4周慢性间歇性低氧组（4IH）和4周慢性间歇性低氧用药组（4IHI）。造模结束后行八臂迷宫测试,TUNEL法检测细胞凋亡,RT-qPCR法了解腺苷A2a受体的mRNA表达,Western blot法测定AMPK及哺乳动物雷帕霉素靶蛋白（mammalian target of rapamycin,mTOR）的磷酸化水平。结果：与对照组相比,2IH组和4IH组的参考记忆错误（RME）、工作记忆错误（WME）和总错误（TE）次数明显增加,差异有统计学显著性（P〈0.01）;4IH与2IH组比较,各项错误次数亦明显增加（P〈0.01）。4IHI组比4IH组RME、WME和TE次数减少,差异有统计学显著性（P〈0.01）。与对照组相比,2IH组和4IH组海马和前额皮层区的神经元凋亡增多,以4IH组凋亡明显（P〈0.05）;4IHI组凋亡较4IH组减少（P〈0.05）。2IH组和4IH组海马和前额皮层区腺苷受体A2a的mRNA和AMPK磷酸化蛋白的水平升高,mTOR磷酸化蛋白的水平下降,4IH组较2IH组改变明显（P〈0.05）。4IHI组较4IH组海马和前额皮层区的AMPK磷酸化蛋白水平下降,mTOR磷酸化蛋白水平升高（P〈0.05）。结论：慢性间歇性低氧诱导神经元凋亡,从而引起幼鼠学习记忆障碍,呈时间依赖性。慢性间歇性低氧上调腺苷A2a受体,激活海马和前额皮层区AMPK,抑制mTOR的活性,诱导神经元凋亡,进而影响幼鼠学习记忆能力。
