scholarly journals Exosomes Derived From Senescent Cells Promote Cellular Senescence

2020 ◽  
Vol 4 (Supplement_1) ◽  
pp. 132-133
Author(s):  
Genxiang Mao ◽  
Xiaogang Xu

Abstract Exosomes are one type of small-cell extracellular vesicles (sEVs), which together with the senescence-associated secretory phenotype (SASP) mainly constitute the senescent microenvironment and perform remotely intercellular communication. However, the effects of senescence on exosomes biosynthesis and secretion and its role in the cell senescence are still obscure. Here, we used human fetal lung diploid fibroblasts (2BS) passaged to PD50 to construct the senescent cells model in vitro, which were confirmed by senescence-related β-galactosidase staining, cell cycle distribution, and intracellular ROS levels. PD30 2BS was used as young control. We evaluated the exosomes derived from senescence and young control group respectively and investigated their regulation of senescence. We found that exosomes released from 2BS had typical sizes and cup-shapes morphology and their surface presented typical exosome-associated proteins. The number of exosomes secreted by senescent cells was significantly higher than that of young cells. Moreover, exosomal markers Alix, TSG101, and CD63 were all more expressed than young cells. Furthermore, we treat young cells with exosomes secreted by senescent cells, which can induce senescence-like changes in young cells, including increased SA-β-Gal activity, up-regulated p16 protein expression, and activation of the Notch signaling pathway. The above results imply that exosomes derived from senescent cells can promote cell senescence. The findings expand the current knowledge on exosomes-mediated aging and provide a novel understanding of the relationship between SASP and senescence. This study is supported by National Natural Science Foundation of China (No. 81771520 and 31702144).

2020 ◽  
Author(s):  
Yanlian Xiong ◽  
Yueming Wang ◽  
Jiashen Zhang ◽  
Nannan Zhao ◽  
Hengchao Zhang ◽  
...  

Abstract Background: Mesenchymal stem cells (MSCs) was considered as regenerative therapeutic approach in both acute and chronic diseases. However, whether MSCs regulate the antioxidant metabolism of CD4+ T cells and weaken immunosenescence remains unclear. Here, we reported the protective effects of hPMSCs in aging-related CD4+ T cell senescence and identified the underlying mechanisms using a D-gal induced mouse aging model.Methods: In vivo study, 40 male C57BL/6 mice (8 weeks) were randomly divided into four groups: control group, D-gal group, hPMSC group and PBS group. In in vitro experiment, human naive CD4+ T (CD4CD45RA) cells were prepared using a naive CD4+ T cell isolation kit II and pretreated with the Akt inhibitor LY294002 and Nrf2 inhibitor ML385. Then, isolated naive CD4+ T cell were cocultured with hPMSCs for 72 h in the absence or presence of anti-CD3/CD28 Dynabeads and IL-2 as a mitogenic stimulus. Intracellular ROS changes were detected by flow cytometry. The activities of the antioxidant enzymes superoxide dismutase, glutathione peroxidase and catalase were measured by colorimetric analysis. The senescent T cells were detected SA-β-gal stain. The expression of aging related proteins were detected by Western blotting, RT-PCR and confocal microscopy.Results: We found that hPMSC treatment markedly decreased the ROS level, SA-β-gal positive cells number, senescence-associated secretory phenotype (IL-6 and OPN) expression and aging-related protein (P16 and P21) expression in senescent CD4+ T cells. Furthermore, hPMSC treatment effectively upregulated Nrf2 nuclear translocation and the expression of downstream target genes (HO-1, CAT, GCLC and NQO1) in senescent CD4+ T cells. Moreover, in vitro studies revealed that hPMSCs attenuated CD4+ T cell senescence by upregulating the Akt/GSK-3β/Fyn pathway to activate Nrf2 functions. Conversely, the antioxidant effects of hPMSCs were blocked by the Akt inhibitor LY294002 and Nrf2 inhibitor ML385 in senescent CD4+ T cells.Conclusions: Our results indicate that hPMSCs attenuate D-gal induced CD4+ T cell senescence by activating Nrf2-mediated antioxidant defenses and that upregulation of Nrf2 by hPMSCs is regulated via the Akt/GSK-3β/Fyn pathway.


2014 ◽  
Vol 26 (6) ◽  
pp. 797 ◽  
Author(s):  
Nathália A. S. Rocha-Frigoni ◽  
Beatriz C. S. Leão ◽  
Ériklis Nogueira ◽  
Mônica F. Accorsi ◽  
Gisele Z. Mingoti

The effects of intracellular (cysteine and β-mercaptoethanol) and extracellular (catalase) antioxidant supplementation at different times during in vitro production (IVM and/or in vitro culture (IVC)) on bovine embryo development, intracellular reactive oxygen species (ROS) levels, apoptosis and re-expansion rates after a vitrification–thawing process were examined. Blastocyst frequencies were not affected by either antioxidant supplementation (40.5%–56.4%) or the timing of supplementation (41.7%–55.4%) compared with control (48.7%; P > 0.05). Similarly, antioxidants and the moment of supplementation did not affect (P > 0.05) the total number of blastomeres (86.2–90.5 and 84.4–90.5, respectively) compared with control (85.7). However, the percentage of apoptotic cells was reduced (P < 0.05) in groups supplemented during IVM (1.7%), IVC (2.0%) or both (1.8%) compared with control (4.3%). Intracellular ROS levels measured in Day 7 blastocysts were reduced (P < 0.05) in all groups (0.60–0.78), with the exception of the group supplemented with β-mercaptoethanol during IVC (0.88), which did not differ (P > 0.05) from that in the control group (1.00). Re-expansion rates were not affected (P > 0.05) by the treatments (50.0%–93.0%). In conclusion, antioxidant supplementation during IVM and/or IVC reduces intracellular ROS and the rate of apoptosis; however, supplementation does not increase embryonic development and survival after vitrification.


2020 ◽  
Author(s):  
Yanlian Xiong ◽  
Yueming Wang ◽  
Jiashen Zhang ◽  
Nannan Zhao ◽  
Aiping Zhang ◽  
...  

Abstract Background: Mesenchymal stem cells (MSCs) was considered as regenerative therapeutic approach in both acute and chronic diseases. However, whether MSCs regulate the antioxidant metabolism of CD4+ T cells and weaken immunosenescence remains unclear. Here, we reported the protective effects of hPMSCs in aging-related CD4+ T cell senescence and identified the underlying mechanisms using a D-gal induced mouse aging model.Methods: In vivo study, 40 male C57BL/6 mice (8 weeks) were randomly divided into four groups: control group, D-gal group, hPMSC group and PBS group. In in vitro experiment, human naive CD4+ T (CD4CD45RA) cells were prepared using a naive CD4+ T cell isolation kit II and pretreated with the Akt inhibitor LY294002 and Nrf2 inhibitor ML385. Then, isolated naive CD4+ T cell were cocultured with hPMSCs for 72 h in the absence or presence of anti-CD3/CD28 Dynabeads and IL-2 as a mitogenic stimulus. Intracellular ROS changes were detected by flow cytometry. The activities of the antioxidant enzymes superoxide dismutase, glutathione peroxidase and catalase were measured by colorimetric analysis. The senescent T cells were detected SA-β-gal stain. The expression of aging related proteins were detected by Western blotting, RT-PCR and confocal microscopy.Results: We found that hPMSC treatment markedly decreased the ROS level, SA-β-gal positive cells number, senescence-associated secretory phenotype (IL-6 and OPN) expression and aging-related protein (P16 and P21) expression in senescent CD4+ T cells. Furthermore, hPMSC treatment effectively upregulated Nrf2 nuclear translocation and the expression of downstream target genes (HO-1, CAT, GCLC and NQO1) in senescent CD4+ T cells. Moreover, in vitro studies revealed that hPMSCs attenuated CD4+ T cell senescence by upregulating the Akt/GSK-3β/Fyn pathway to activate Nrf2 functions. Conversely, the antioxidant effects of hPMSCs were blocked by the Akt inhibitor LY294002 and Nrf2 inhibitor ML385 in senescent CD4+ T cells.Conclusions: Our results indicate that hPMSCs attenuate D-gal induced CD4+ T cell senescence by activating Nrf2-mediated antioxidant defenses and that upregulation of Nrf2 by hPMSCs is regulated via the Akt/GSK-3β/Fyn pathway.


1995 ◽  
Vol 268 (5) ◽  
pp. L818-L825 ◽  
Author(s):  
M. J. Acarregui ◽  
J. J. Brown ◽  
R. K. Mallampalli

We studied the effect of 20-95% O2 on mRNA levels for the surfactant-associated proteins (SP)-A, SP-B, and SP-C and [3H]choline incorporation into total phosphatidylcholine and type II cell-specific disaturated phosphatidylcholine (DPPC) in human fetal lung in culture. SP-A mRNA levels were increased by 25 and 39% in lung explants incubated in 70 and 95% O2, respectively, compared with levels in tissues incubated in 20% O2. SP-B mRNA levels were unaffected by O2, whereas SP-C mRNA levels were increased by 85, 102, and 115% in atmospheres of 35, 50, and 70% O2, respectively. [3H]choline incorporation into total phosphatidylcholine and DPPC were both increased in human fetal lung explants incubated in increased O2 concentrations compared with tissues incubated in 20% O2. Tissue levels of adenosine 3',5'-cyclic monophosphate (cAMP)-dependent protein kinase (PKA) activity were not affected by O2 concentration, implying that the changes observed in SP mRNA levels and [3H]choline incorporation may not be mediated through alterations in PKA enzyme activity. These findings demonstrate that O2 regulates SP mRNA expression and phospholipid production in human fetal lung in vitro. We speculate that surfactant composition and possibly function may be regulated by O2 in human lung.


2019 ◽  
Vol 01 (04) ◽  
pp. 161-168
Author(s):  
Lan N. Vuong ◽  
Toan D. Pham ◽  
Bao G. Huynh ◽  
Quynh N. Nguyen ◽  
Tuong M. Ho ◽  
...  

Background: Embryo quality is an important predictor of successful outcome in in vitro fertilization (IVF). However, current knowledge on the live birth rate after transfer of poor quality embryos is limited. This study investigated the live birth rate after transfer of only poor quality day-3 embryos in women undergoing IVF. Methods: This retrospective study included 153 couples who underwent IVF at IVFMD, My Duc Hospital, Ho Chi Minh City, Vietnam between June 2014 and January 2017 and had only poor quality day-3 embryos available for fresh (n [Formula: see text] 102) or frozen (n [Formula: see text] 51) transfer. The control group included patients who had transfer of one good embryo (n [Formula: see text] 64). Embryos were rated using the Istanbul criteria. Results: In the poor quality embryo group, the mean number of oocytes retrieved and number of embryos were 7.5 ± 4.4 and 1.8 ± 0.9, respectively. Mean number of embryos transferred was 1.6 ± 0.5 in the fresh transfer group and 2.0 ± 0.2 in the freeze-only group. Live births did occur after transfer of poor quality embryos, but the implantation, clinical pregnancy and live birth rates were significantly lower than after fresh or frozen transfer of a single good quality embryo (9.5 vs. 26.6%, p < 0.001; 13.7 vs. 26.6%, p < 0.001; and 7.2 vs. 18.8%, p [Formula: see text] 0.02, respectively). Conclusions: Live birth was achieved after transfer of only poor quality embryos in women undergoing IVF. This suggests that transfer of poor quality embryos could be an option when higher grade embryos are not available, after the chances of live birth have been discussed with the patient.


2015 ◽  
Vol 2015 ◽  
pp. 1-6 ◽  
Author(s):  
Wenjing Wang ◽  
Maomin Lv ◽  
Chaoji Huangfu ◽  
Fang Wang ◽  
Jingang Zhang

Purpose. Radiotherapy is an effective treatment modality in the clinical treatment of breast cancer. The present work investigated the effect of 3,3′-diindolylmethane (DIM) onγ-irradiation sensitizing human breast carcinoma.Methods. Cell survival, intracellular ROS levels, cell cycle distribution, cell apoptosis, and expression of proteins related to apoptosis were measured with MTT assays, flow cytometry, and Western blot analysis, respectively.Results.In vitroDIM plusγ-irradiation arrested the activity of G2/M phase cell cycle, increased intracellular ROS level, significantly suppressed PARP (poly ADP-ribose polymerase), and enhancedγ-irradiation-induced apoptosis, thereby inhibiting the proliferation of MCF-7 cells.Conclusion. These data provide a rationale for the use of DIM as a promising sensitizer ofγ-irradiation.


2021 ◽  
Vol 2021 ◽  
pp. 1-11
Author(s):  
Jinhua Zhang ◽  
Bo Yang ◽  
Lilin Luo ◽  
Linhui Li ◽  
Xuantao Yang ◽  
...  

Human bone marrow mesenchymal stem cells (h-BMSCs) have the potential to differentiate into dopaminergic neuron-like cells to treat Parkinson’s disease. The Notch signaling pathway has been implicated in the regulation of cell fate decisions such as differentiation of BMSCs. This study investigated changes in the expression of Notch-related genes in the differentiation of BMSCs in vitro into dopaminergic (DA) neuron-like cells. BMSCs transfected with empty lentiviral vectors served as the control group and those transfected with NTN and Lmx1α recombinant lentiviral vectors served as the experimental group. After induction and culture of NTN and Lmx1α-transfected h-BMSCs for 21 days, the cells exhibited features of dopaminergic neuron-like cells, which were observed by transmission and scanning electron microscopy and verified by immunofluorescence of tyrosine hydroxylase (TH) and dopamine transporter (DAT). These induced cells could secrete dopamine and had basic action potentials. Expression of the neural stem cell (NSC) markers, including octamer-binding protein (Oct4), paired box gene 6 (Pax6), and sex determining region Y-box 1 (SOX1), increased on day 14 of induction and decreased on day 21 of induction during differentiation. The human Notch signaling pathway PCR array showed a differential expression of Notch-related genes during the differentiation of h-BMSCs into DA neuron-like cells in vitro relative to that in the control group. In conclusion, h-BMSCs overexpressing NTN and Lmx1α can successfully be induced to differentiate into dopaminergic neuron-like cells with a neuronal phenotype exhibiting fundamental biological functions in vitro, and NTN and Lmx1α may affect the expression of Notch-related genes during differentiation.


Dermatology ◽  
2019 ◽  
Vol 236 (5) ◽  
pp. 454-466
Author(s):  
Zhenghui Yang ◽  
Hao Xiong ◽  
Shanshan Wei ◽  
Qingxiu Liu ◽  
Yan Gao ◽  
...  

Objective: Investigate the role of Yes-associated protein (YAP1) in the development of condyloma acuminatum (CA). Methods: We enrolled 30 male patients with CA and 20 healthy individuals as a control group, to compare the YAP1 expression in their tissue samples. Following this, we overexpressed and downregulated YAP1 expression in HaCaT cells to examine the migratory, proliferative, and apoptotic potential of HaCaT cells expressing different levels of YAP1. Results: In the CA patient tissue samples, an increase in YAP1 expression can be observed. In vitro,the overexpression of YAP1 was shown to promote the growth and migration of HaCaT cells and to activate epidermal growth factor receptor (EGFR) pathway-associated proteins, while the downregulation of YAP1 inhibited cell growth and migration of these cells. Conclusions: YAP1 promotes the growth of keratinocytes in CA through the activation of the EGFR pathway, and it may mediate the development of human papilloma virus-associated diseases.


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