scholarly journals Correction to Supporting Information for Chibaya et al., Mdm2 phosphorylation by Akt regulates the p53 response to oxidative stress to promote cell proliferation and tumorigenesis

2021 ◽  
Vol 118 (9) ◽  
pp. e2101572118
Keyword(s):  
Oxidative Stress ◽  
Cell Proliferation ◽  
Promote Cell Proliferation ◽  
P53 Response

scholarly journals Mdm2 phosphorylation by Akt regulates the p53 response to oxidative stress to promote cell proliferation and tumorigenesis

2021 ◽  
Vol 118 (4) ◽  
pp. e2003193118
Author(s):  
Loretah Chibaya ◽  
Baktiar Karim ◽  
Hong Zhang ◽  
Stephen N. Jones
Keyword(s):  
Oxidative Stress ◽  
Dna Damage ◽  
Ionizing Radiation ◽  
Bone Marrow Failure ◽  
Lung Cancers ◽  
Promote Cell Proliferation ◽  
Akt Phosphorylation ◽  
Mediated Effects ◽  
P53 Signaling ◽  
P53 Response

We have shown previously that phosphorylation of Mdm2 by ATM and c-Abl regulates Mdm2-p53 signaling and alters the effects of DNA damage in mice, including bone marrow failure and tumorigenesis induced by ionizing radiation. Here, we examine the physiological effects of Mdm2 phosphorylation by Akt, another DNA damage effector kinase. Surprisingly, Akt phosphorylation of Mdm2 does not alter the p53-mediated effects of ionizing radiation in cells or mice but regulates the p53 response to oxidative stress. Akt phosphorylation of Mdm2 serine residue 183 increases nuclear Mdm2 stability, decreases p53 levels, and prevents senescence in primary cells exposed to reactive oxidative species (ROS). Using multiple mouse models of ROS-induced cancer, we show that Mdm2 phosphorylation by Akt reduces senescence to promote KrasG12D-driven lung cancers and carcinogen-induced papilloma and hepatocellular carcinomas. Collectively, we document a unique physiologic role for Akt-Mdm2-p53 signaling in regulating cell growth and tumorigenesis in response to oxidative stress.

Effect of Substance P on Differentiation of Bone Marrow Stromal Stem Cells Under Oxidative Stress

2021 ◽  
Vol 11 (4) ◽  
pp. 772-777
Author(s):  
Wei Song ◽  
Jun Wang ◽  
Yumin Zhang ◽  
Tao Ma ◽  
Kunzheng Wang
Keyword(s):  
Oxidative Stress ◽  
Stem Cells ◽  
Bone Marrow ◽  
Cell Proliferation ◽  
Substance P ◽  
Control Group ◽  
Sod Activity ◽  
Promote Cell Proliferation ◽  
Alp Activity ◽  
Stromal Stem Cells

Bone marrow stromal stem cells (BMSCs) can be used to treat bone defects but BMSCs are damaged under oxidative stress. The neuropeptide substance P (SP) involves various cellular activities. However, SP’s role in BMSCs differentiation under oxidative stress is unknown. Rat BMSCs were isolated and assigned into control group; oxidative stress group treated with 200 μM H2O2; and SP group, in which 10 mM SP was added under oxidative stress followed by analysis of SP secretion by ELISA, cell proliferation by MTT method, Caspase3 activity, Bax and Bcl-2 level by Real time PCR, ALP activity ROS and SOD content as well as NF-κB level by Western blot. Under oxidative stress, SP secretion was significantly decreased, BMSCs proliferation was inhibited, Caspase3 activity and Bax expression increased, Bcl-2 and ALP activity was decreased along with increased ROS activity and NF-κB level and reduced SOD activity (P <0.05), adding SP to BMSCs under oxidative stress can significantly promote SP secretion and cell proliferation, reduce Caspase3 activity and Bax expression, increase Bcl-2 expression and ALP activity, decreased ROS activity and NF-κB level, and elevated SOD activity (P <0.05). SP secretion from BMSCs cells was reduced under oxidative stress. Up-regulation of SP in BMSCs cells under oxidative stress can inhibit BMSCs apoptosis and promote cell proliferation and osteogenesis by regulating NF-κB.

scholarly journals NRF2-mediated signaling is a master regulator of transcription factors in bovine granulosa cells under oxidative stress condition

2021 ◽  
Author(s):  
Mohamed Omar Taqi ◽  
Mohammed Saeed-Zidane ◽  
Samuel Gebremedhn ◽  
Dessie Salilew-Wondim ◽  
Ernst Tholen ◽  
...  
Keyword(s):  
Oxidative Stress ◽  
Cell Proliferation ◽  
Endoplasmic Reticulum ◽  
Transcription Factors ◽  
Endoplasmic Reticulum Stress ◽  
Granulosa Cells ◽  
Mitochondrial Activity ◽  
Small Interference Rna ◽  
Nrf2 Signaling Pathway

AbstractTranscription factors (TFs) are known to be involved in regulating the expression of several classes of genes during folliculogenesis. However, the regulatory role of TFs during oxidative stress (OS) is not fully understood. The current study was aimed to investigate the regulation of the TFs in bovine granulosa cells (bGCs) during exposure to OS induced by H2O2 in vitro. For this, bGCs derived from ovarian follicles were cultured in vitro till their confluency and then treated with H2O2 for 40 min. Twenty-four hours later, cells were subjected to various phenotypic and gene expression analyses for genes related to TFs, endoplasmic reticulum stress, apoptosis, cell proliferation, and differentiation markers. The bGCs exhibited higher reactive oxygen species accumulation, DNA fragmentation, and endoplasmic reticulum stress accompanied by reduction of mitochondrial activity after exposure to OS. In addition, higher lipid accumulation and lower cell proliferation were noticed in H2O2-challenged cells. The mRNA level of TFs including NRF2, E2F1, KLF6, KLF9, FOS, SREBF1, SREBF2, and NOTCH1 was increased in H2O2-treated cells compared with non-treated controls. However, the expression level of KLF4 and its downstream gene, CCNB1, were downregulated in the H2O2-challenged group. Moreover, targeted inhibition of NRF2 using small interference RNA resulted in reduced expression of KLF9, FOS, SREBF2, and NOTCH1 genes, while the expression of KLF4 was upregulated. Taken together, bovine granulosa cells exposed to OS exhibited differential expression of various transcription factors, which are mediated by the NRF2 signaling pathway.

scholarly journals THU0495 NOVEL UNDERSTANDING OF THE PATHOGENESIS OF JUVENILE IDIOPATHIC ARTHRITIS: FOCUS ON MESENCHYMAL STEM CELLS IMPAIRMENT, SENESCENCE AND IMMUNOREGULATORY FUNCTION

2020 ◽  
Vol 79 (Suppl 1) ◽  
pp. 483.2-484
Author(s):  
L. Zaripova ◽  
A. Midgley ◽  
S. Christmas ◽  
E. Baildam ◽  
R. Oldershaw
Keyword(s):  
Oxidative Stress ◽  
Cell Cycle ◽  
Stem Cells ◽  
Cell Proliferation ◽  
Mesenchymal Stem Cells ◽  
Juvenile Idiopathic Arthritis ◽  
Metabolic Activity ◽  
Healthy Controls ◽  
High Level ◽  
Pro Inflammatory Cytokines

Background:Juvenile idiopathic arthritis (JIA) is a well-known chronic rheumatic disease of childhood characterised by progressive joint destruction and severe systemic complications.Immune cells are known to trigger the pathophysiological cascade in JIA, but there is little information regarding the contribution made by Mesenchymal stem cells (MSCs). These cells are able to modulate the immune response and decrease the level of pro-inflammatory cytokines. With addition of regenerative property it makes MSCs potential candidates for clinical application as immunosuppressants in treatment of autoimmune diseases.Objectives:To investigate MSCs proliferation, viability and immunomodulatory function in JIA and healthy children.Methods:MSCs were separated from peripheral blood (PB) and synovial fluid (SF) of JIA patients and healthy controls. Cell proliferation rate was counted by Population doublings per day (PDD) during 9 days, in the last of which alamarBlue™ assays were performed to assess cell viability. Due to measure senescence MSCs were stained with SA-β-galactosidase. Immunofluorescence was used to examine the expression of p16, p21, p53. Oxidative stress was measured with DCFH-DA. Cell cycle analysis was evaluated with Propidium Iodide and analysed by Accuri® C6 Flow Cytometer.Commercially-available bone marrow mesenchymal stem cells (BM-MSCs) were treated with graded concentrations of pro-inflammatory cytokines (0.1-100 ng/ml) with following examination of cell viability. Mixed lymphocyte reactions (MLR) were performed to measure MSC immunomodulatory abilityin vitro.Results:The growth kinetics of JIA-MSCs were different from healthy controls. JIA-MSCs divided slowly and appeared disorganised with large cytoplasm and loads of outgrowth. They demonstrated a decrease in cell proliferation (negative PDD) and metabolic activity. Difference in growth kinetics and metabolic activity were found inside the JIA PB group with some evidence of response following biological treatment. Thus, PB-MSCs from patients treated with TNFi and anti-IL6 medications had notably higher cell proliferation and metabolic activity against JIA patients received other therapy. Considering this difference, it was hypothesised that cytokines obtained in a high amount in PB and SF of JIA patients may influence MSCs viability. To prove this BM-MSCs were treated with cytokines and demonstrated a dose-dependent decrease in metabolic activity significantly after TNFα and IL1, no significantly after treatment with IL6. Both BM-MSCs treated with cytokines and JIA-MSCs displayed high level of reactive oxygen species.Cell cycle analysis revealed that JIA-MSCs were arrested in G0/G1 phase with low number of mitotic cells. In addition, the number of senescence-associated SA-β-gal-positive cells was notably higher in JIA-MSCs. Furthermore, JIA-MSCs expressed high level of immunofluorescence for p16, p21 and p53 which played an important role in regulating the senescence progress of MSCs.Results of MLR showed the ability of BM-MSCs to decrease the percentage of activated T-helpers, T-suppressors, B-cells and natural killers proliferation, while JIA-MSCs lost this property.Conclusion:Taken together current research has demonstrated that under the influence of proinflammatory cytokines JIA-MSCs suffered from oxidative stress and disruption of metabolic activity acquire senescent morphology, shorten of telomere length, arrest in G0 phase of cell cycle and finally loss of immune regulation. We are continuing our research to determine the mechanisms that are responsible for the impaired phenotype with the aim of identifying new therapeutic strategies for the treatment of JIA.Disclosure of Interests: :None declared

scholarly journals HPV-18 E6 Oncoprotein and Its Spliced Isoform E6*I Regulate the Wnt/β-Catenin Cell Signaling Pathway through the TCF-4 Transcriptional Factor

2018 ◽  
Vol 19 (10) ◽  
pp. 3153 ◽  
Author(s):  
J. Muñoz-Bello ◽  
Leslie Olmedo-Nieva ◽  
Leonardo Castro-Muñoz ◽  
Joaquín Manzo-Merino ◽  
Adriana Contreras-Paredes ◽  
...  
Keyword(s):  
Cervical Cancer ◽  
Cell Proliferation ◽  
Signaling Pathway ◽  
Transcriptional Activation ◽  
Target Genes ◽  
Promote Cell Proliferation ◽  
E6 And E7 ◽  
Hpv 18

The Wnt/β-catenin signaling pathway regulates cell proliferation and differentiation and its aberrant activation in cervical cancer has been described. Persistent infection with high risk human papillomavirus (HR-HPV) is the most important factor for the development of this neoplasia, since E6 and E7 viral oncoproteins alter cellular processes, promoting cervical cancer development. A role of HPV-16 E6 in Wnt/β-catenin signaling has been proposed, although the participation of HPV-18 E6 has not been previously studied. The aim of this work was to investigate the participation of HPV-18 E6 and E6*I, in the regulation of the Wnt/β-catenin signaling pathway. Here, we show that E6 proteins up-regulate TCF-4 transcriptional activity and promote overexpression of Wnt target genes. In addition, it was demonstrated that E6 and E6*I bind to the TCF-4 (T cell factor 4) and β-catenin, impacting TCF-4 stabilization. We found that both E6 and E6*I proteins interact with the promoter of Sp5, in vitro and in vivo. Moreover, although differences in TCF-4 transcriptional activation were found among E6 intratype variants, no changes were observed in the levels of regulated genes. Furthermore, our data support that E6 proteins cooperate with β-catenin to promote cell proliferation.

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