Although the mTOR-4E-BP1 signaling pathway is implicated in aging and aging-related disorders,the role of 4E-BP1 in regulating human stem cell homeostasis remains largely unknown.Here,we report that the expression of ...Although the mTOR-4E-BP1 signaling pathway is implicated in aging and aging-related disorders,the role of 4E-BP1 in regulating human stem cell homeostasis remains largely unknown.Here,we report that the expression of 4E-BP1 decreases along with the senescence of human mesenchymal stem celis(hMSCs).Genetic inactivation of 4E-BP1 in hMSCs compromises mitochondrial respiration,increases mitochondrial reactive oxygen species(Ros)production,and accelerates cellular senescence.Mechanistically,the absence of 4E-BP1 destabilizes proteins in mitochondrial respiration complexes,especially several key subunits of complex III including UQCRC2.Ectopic expression of 4E-BP1 attenuates mitochondrial abnormalities and alleviates cellular senescence in 4E-BP1-deficient hMSCs as well as in physiologically aged hMSCs.These findings together demonstrate that 4E-BP1 functions as a geroprotector to mitigate human stem cell senescence and maintain mitochondrial homeostasis,particularly for the mitochondrial respiration complex Il,thus providing a new potential target to counteract human stem cell senescence.展开更多
Objective:To investigate the mechanism of MiR-34a-mediated mTOR/4E-BP1 signaling pathway on apoptosis of esophageal cancer cells.Methods:Esophageal cancer cell lines were purchased from the ATCC cell bank and randomly...Objective:To investigate the mechanism of MiR-34a-mediated mTOR/4E-BP1 signaling pathway on apoptosis of esophageal cancer cells.Methods:Esophageal cancer cell lines were purchased from the ATCC cell bank and randomly divided into three groups. The first group, miR-34a group (miR-34a group): transfected miR-34a mimics into esophageal cancer cells by transfection;The second group, esophageal cancer group (EC group): simple esophageal cancer cell line without other treatment, normal culture;third group, idling group (ID group): transfected miR-34a negative control into esophageal cancer cell line . To explore MiR by qRT-PCR, TUNEL, cck-8 and Westernblot in the detection of miR-34a mRNA expression, apoptosis, proliferation, and protein content of mTOR/4E-BP1 in esophageal cancer cells. -34a mediates the mechanism of mTOR/4E-BP1 signaling pathway on apoptosis of esophageal cancer cells.Results:The results of qRT-PCR showed that the expression of miR-34a mRNA was the lowest in esophageal cancer cells in EC group, and the highest in miR-34a group in miR-34a group, miR-34a group and ID group, EC Compared with the group, the miR-34a mRNA content increased significantly, indicating successful transfection (allP<0.05). The results of TUNEL showed that the number of apoptosis of esophageal cancer cells in EC group was the least, and the apoptosis of esophageal carcinoma cells in miR-34a group was significantly increased. The apoptosis rate of miR-34a group was significantly higher than that of EC group and ID group (P<0.05). There was no significant difference in apoptosis between EC group and ID group. The OD value of cell proliferation in ID group and EC group was higher than that in miR-34a group, and there was significant difference between groups (P<0.05). The proliferation of esophageal cancer cells in EC group was the highest, and the number of esophageal cancer cells in miR-34a group was the least. There was no significant difference in the proliferation of esophageal cancer cells in the ID group compared with the EC group (P>0.05). The mTOR/4E-BP1 protein in esophageal cancer cells of EC group, ID group and miR-34a group was immunoblotted by Western blot. The gray scale showed that the mTOR/4E-BP1 protein content of EC group was the highest, EC group and Compared with the ID group, the protein content was similar, no significant (P>0.05), and the miR-34a group had the lowest protein content. Compared with the EC group and the ID group, the miR-34a group had lower protein content in esophageal cancer cells (allP< 0.05).Conclusions:MiR-34a may promote the apoptosis of esophageal cancer cells by inhibiting the expression of mTOR/4E-BP1 signaling pathway.展开更多
Introduction: The consensus report issued jointly by the American Diabetes Association and the American Cancer Society stated that “type 2 diabetes and cancer share many risk factors, but potential biologic links bet...Introduction: The consensus report issued jointly by the American Diabetes Association and the American Cancer Society stated that “type 2 diabetes and cancer share many risk factors, but potential biologic links between the two diseases are incompletely understood”. Interestingly, however, a recent report suggested that the expression of p27(Kip1), a cell cycle repressor protein, in the rodent liver was inversely associated with potential carcinogenic risk in the genetic rodent models of diabetic obesity. p27 is a cyclin-dependent kinase inhibitor that, when down-regulated, allows the progression of the cell cycle from G1 to S phase, thereby increasing the risk of developing cancer. Objective: The objective of the study described below was to extend the results of the recent report on the expression of p27 in the livers of obese, diabetic rodents to the humans and investigate whether the expression of p27 in the human peripheral blood mononuclear cells (PBMCs) might also be inversely associated with potential carcinogenic risk in obese type 2 diabetic individuals relative to the lean normal controls. Methods: Western immunoblot analysis was performed to evaluate the expression of p27 and the two most relevant upstream molecular signaling pathways of the expression of p27, namely 4E-BP1 and MNK1, in human PBMCs obtained from obese type 2 diabetic individuals relative to the lean normal controls. Results: First, expression of p27 in human PBMCs was significantly down-regulated in obese type 2 diabetic individuals relative to the lean normal controls. Secondly, expression of p27 in human PBMCs was also significantly down-regulated in obese type 2 diabetic African Americans relative even to the obese type 2 diabetic Caucasian Americans. Conclusions: Expression of p27 in human PBMCs was inversely associated with potential carcinogenic risk in obese type 2 diabetes relative to the lean normal controls.展开更多
基金supported by the National Key Research and Development Program of China(2018YFC2000100)the Strategic Priority Research Program of the Chinese Academy of Sciences(XDA16000000)+9 种基金the National Natural Science Foundation of China(8190143281921006,82125011,92149301,92168201,91949209,92049304,92049116,32121001,82192863,82122024,82071588,81861168034,81922027,81870228,32100937,31900524,82201727)the National Key Research and Development Program of China(2020YFA0804000,2020YFA0113400,2020YFA0112200,2018YFA0107203,the STI2030-Major Projects-2021ZD0202400,2021YFF1201005,2022YFA1103700,2022YFA1103800)CAS Project for Young Scientists in Basic Research(YSBR-076,YSBR-012)the Program of the Beijing Natural Science Foundation(Z190019,JQ20031)K.C.Wong Education Foundation(GJTD-2019-06,GJTD-2019-08)Young Elite Scientists Sponsorship Program by CAST(YESS20200012)Youth Innovation Promotion Association of CAS(EiCAZW0401)the Pilot Project for Public Welfare Development and Reform of Beijing-affliated Medical Research Institutes(11000022T000000461062)the Informatization Plan of Chinese Academy of Sciences(CAS-WX2021SF-0301,CASWX2022SDC-XK14)CAS Special Research Assistant(SRA)Program,and the Tencent Foundation(2021-1045).
文摘Although the mTOR-4E-BP1 signaling pathway is implicated in aging and aging-related disorders,the role of 4E-BP1 in regulating human stem cell homeostasis remains largely unknown.Here,we report that the expression of 4E-BP1 decreases along with the senescence of human mesenchymal stem celis(hMSCs).Genetic inactivation of 4E-BP1 in hMSCs compromises mitochondrial respiration,increases mitochondrial reactive oxygen species(Ros)production,and accelerates cellular senescence.Mechanistically,the absence of 4E-BP1 destabilizes proteins in mitochondrial respiration complexes,especially several key subunits of complex III including UQCRC2.Ectopic expression of 4E-BP1 attenuates mitochondrial abnormalities and alleviates cellular senescence in 4E-BP1-deficient hMSCs as well as in physiologically aged hMSCs.These findings together demonstrate that 4E-BP1 functions as a geroprotector to mitigate human stem cell senescence and maintain mitochondrial homeostasis,particularly for the mitochondrial respiration complex Il,thus providing a new potential target to counteract human stem cell senescence.
基金National Youth Science Fund Project(No.8180140119).
文摘Objective:To investigate the mechanism of MiR-34a-mediated mTOR/4E-BP1 signaling pathway on apoptosis of esophageal cancer cells.Methods:Esophageal cancer cell lines were purchased from the ATCC cell bank and randomly divided into three groups. The first group, miR-34a group (miR-34a group): transfected miR-34a mimics into esophageal cancer cells by transfection;The second group, esophageal cancer group (EC group): simple esophageal cancer cell line without other treatment, normal culture;third group, idling group (ID group): transfected miR-34a negative control into esophageal cancer cell line . To explore MiR by qRT-PCR, TUNEL, cck-8 and Westernblot in the detection of miR-34a mRNA expression, apoptosis, proliferation, and protein content of mTOR/4E-BP1 in esophageal cancer cells. -34a mediates the mechanism of mTOR/4E-BP1 signaling pathway on apoptosis of esophageal cancer cells.Results:The results of qRT-PCR showed that the expression of miR-34a mRNA was the lowest in esophageal cancer cells in EC group, and the highest in miR-34a group in miR-34a group, miR-34a group and ID group, EC Compared with the group, the miR-34a mRNA content increased significantly, indicating successful transfection (allP<0.05). The results of TUNEL showed that the number of apoptosis of esophageal cancer cells in EC group was the least, and the apoptosis of esophageal carcinoma cells in miR-34a group was significantly increased. The apoptosis rate of miR-34a group was significantly higher than that of EC group and ID group (P<0.05). There was no significant difference in apoptosis between EC group and ID group. The OD value of cell proliferation in ID group and EC group was higher than that in miR-34a group, and there was significant difference between groups (P<0.05). The proliferation of esophageal cancer cells in EC group was the highest, and the number of esophageal cancer cells in miR-34a group was the least. There was no significant difference in the proliferation of esophageal cancer cells in the ID group compared with the EC group (P>0.05). The mTOR/4E-BP1 protein in esophageal cancer cells of EC group, ID group and miR-34a group was immunoblotted by Western blot. The gray scale showed that the mTOR/4E-BP1 protein content of EC group was the highest, EC group and Compared with the ID group, the protein content was similar, no significant (P>0.05), and the miR-34a group had the lowest protein content. Compared with the EC group and the ID group, the miR-34a group had lower protein content in esophageal cancer cells (allP< 0.05).Conclusions:MiR-34a may promote the apoptosis of esophageal cancer cells by inhibiting the expression of mTOR/4E-BP1 signaling pathway.
文摘Introduction: The consensus report issued jointly by the American Diabetes Association and the American Cancer Society stated that “type 2 diabetes and cancer share many risk factors, but potential biologic links between the two diseases are incompletely understood”. Interestingly, however, a recent report suggested that the expression of p27(Kip1), a cell cycle repressor protein, in the rodent liver was inversely associated with potential carcinogenic risk in the genetic rodent models of diabetic obesity. p27 is a cyclin-dependent kinase inhibitor that, when down-regulated, allows the progression of the cell cycle from G1 to S phase, thereby increasing the risk of developing cancer. Objective: The objective of the study described below was to extend the results of the recent report on the expression of p27 in the livers of obese, diabetic rodents to the humans and investigate whether the expression of p27 in the human peripheral blood mononuclear cells (PBMCs) might also be inversely associated with potential carcinogenic risk in obese type 2 diabetic individuals relative to the lean normal controls. Methods: Western immunoblot analysis was performed to evaluate the expression of p27 and the two most relevant upstream molecular signaling pathways of the expression of p27, namely 4E-BP1 and MNK1, in human PBMCs obtained from obese type 2 diabetic individuals relative to the lean normal controls. Results: First, expression of p27 in human PBMCs was significantly down-regulated in obese type 2 diabetic individuals relative to the lean normal controls. Secondly, expression of p27 in human PBMCs was also significantly down-regulated in obese type 2 diabetic African Americans relative even to the obese type 2 diabetic Caucasian Americans. Conclusions: Expression of p27 in human PBMCs was inversely associated with potential carcinogenic risk in obese type 2 diabetes relative to the lean normal controls.
