Project description:Transformed human esophageal keratinocyte cell line EPC2-T (EPC2-hTERT-EGFR-cyclin D1-p53R175H) cells were stimulated with or without 2.5 ng/ml recombinant human TGF-beta1 for 10 days. The above cells were subjected to treatment for 10 days with or without 0.5 µg/ml doxycycline (DOX) to activate tetracycline-inducible (tet-on) ICN1, an active form of Notch1.
Project description:Senescence, a persistent form of cell cycle arrest, is often associated with a diverse secretome, which provides complex downstream functionality for senescent cells within the tissue microenvironment. We show that oncogene-induced senescence (OIS) is accompanied by a dynamic fluctuation of NOTCH1 activity, which drives a TGF-β-rich secretome, whilst suppressing the senescence-associated pro-inflammatory secretome through inhibition of C/EBPβ. NOTCH1 and NOTCH1-driven TGF-β contribute to ‘lateral induction of senescence’ through a juxtacrine NOTCH-JAG1 pathway. In addition, NOTCH1 inhibition during senescence facilitates upregulation of pro-inflammatory cytokines, promoting lymphocyte recruitment and senescence surveillance in vivo. Because enforced activation of NOTCH1 signalling confers a near mutually exclusive secretory profile compared to typical senescence, our data collectively indicate that the dynamic alteration of NOTCH1 activity during senescence dictates a functional balance between these two distinct secretomes: one representing TGF-β and the other pro-inflammatory cytokines, highlighting that NOTCH1 is a temporospatial controller of secretome composition.
Project description:For chondrogenic studies of optogenetically activated TGF-β signaling, optogenetic human iPSC-derived MSCs were encapsulated in hydrogels (20 million cells/mL of 2% agarose hydrogel). Groups received either no soluble TGF-β or optogenetic stimulation, or soluble TGF-β3 alone, or optogenetic stimulation alone. After 21 days of differentiation, we performed global quantitative proteomics on samples from two independent experiments, with n=3 replicates per group.
Project description:TGF-beta plays multiple functions in a board range of cellular responses such as proliferation, differentiation, motility and survival by activating several cellular signaling pathways, including Smads and MAP kinases (Erk, JNK and p38). In particular, TGF-beta can activate pro- or anti-apoptotic signals depending on the target cells. We found that blockage of JNK activation sensitized mouse B lymphoma derived A20 cells to TGF-beta-induced apoptosis. These results suggest that TGF-beta activate JNK to inhibit the activation of death signal that is simultaneously activated by TGF-beta. We used microarrays to gain insight into the effects of JNK inhibition on gene expression in TGF-b-stimulated A20 cells and identified JNK-dependent TGF-beta inducible genes. Experiment Overall Design: The following six samples were prepared: untreated A20 cells (non-stimulated, DMSO): A20 cells cultured with SP600125 for 24 h (non-stimulated, SP600125): A20 cells stimulated with TGF-beta for 12 h (TGF-beta 12 h, DMSO) and 24 h (TGF-beta 24 h, DMSO): and A20 cells stimulated with TGF-beta in the presence of SP600125 for 12 h (TGF-beta 12 h, SP600125) and 24 h (TGF-beta 24 h, SP600125), respectively. Total RNA was prepared and hybridized to the Affymetrix Mouse Genome 430 2.0 array. Genes whose expression was increased by more than 2-fold at either 12 or 24 h after TGF-beta stimulation were identified as TGF-beta inducible genes. Amongst them, we identified genes whose induction levels were reduced by more than 75% by co-treatment with the JNK inhibitor SP600125.
Project description:This model is from the article:
Quantitative analysis of transient and sustained transforming growth factor-β signaling dynamics.
Zhike Zi, Zipei Feng, Douglas A Chapnick, Markus Dahl, Difan Deng, Edda Klipp, Aristidis Moustakas & Xuedong Liu Molecular Systems Biology
2011 May 24;7:492. 21613981
,
Abstract:
Mammalian cells can decode the concentration of extracellular transforming growth factor-β (TGF-β) and transduce this cue into appropriate cell fate decisions. How variable TGF-β ligand doses quantitatively control intracellular signaling dynamics and how continuous ligand doses are translated into discontinuous cellular fate decisions remain poorly understood. Using a combined experimental and mathematical modeling approach, we discovered that cells respond differently to continuous and pulsating TGF-β stimulation. The TGF-β pathway elicits a transient signaling response to a single pulse of TGF-β stimulation, whereas it is capable of integrating repeated pulses of ligand stimulation at short time interval, resulting in sustained phospho-Smad2 and transcriptional responses. Additionally, the TGF-β pathway displays different sensitivities to ligand doses at different time scales. While ligand-induced short-term Smad2 phosphorylation is graded, long-term Smad2 phosphorylation is switch-like to a small change in TGF-β levels. Correspondingly, the short-term Smad7 gene expression is graded, while long-term PAI-1 gene expression is switch-like, as is the long-term growth inhibitory response. Our results suggest that long-term switch-like signaling responses in the TGF-β pathway might be critical for cell fate determination.
Note:
Developer of the model: Zhike Zi
Reference: Zi Z. et al., Quantitative Analysis of Transient and Sustained Transforming Growth Factor-beta Signaling Dynamics, Molecular Systems Biology, 2011
1. The global parameter that set the type of stimulation
(a) for sustained TGF-beta stimulation: set stimulation_type = 1.
(b) for single pulse of TGF-beta stimulation: set stimulation_type = 2.
parameter "single_pulse_duration" is for the duration of stimulation, for example,
single_pulse_duration = 0.5, for 0.5 min (30 seconds) of TGF-beta stimulation.
*Note: make sure that the time course cover the time point when the event is triggered.
(c) for single pulse of TGF-beta stimulation in COPASI
change the trigger of event "single_pulse_TGF_beta_washout"
from
"and(eq(stimulation_type, 2), eq(time, single_pulse_duration))" (for SBML-SAT)
to
"and(eq(stimulation_type, 2), gt(time, single_pulse_duration))" (for COPASI)
2. Notes for TGF-beta dose in terms of molecules per cell
(a) The following equation applies for conversion of TGF-beta dose in molecules per cell
TGF_beta_dose_mol_per_cell = initial TGF_beta_ex*1e-9*Vmed*6e23
(b) for standard experimental setup 1e6 cells in 2 mL medium
0.001 nM initial TGF_beta_ex is approximately equal to the dose of 1200 TGF-beta molecules/cell
0.050 nM initial TGF_beta_ex is approximately equal to the dose of 60000 TGF-beta molecules/cell
(c) For 1e6 cells in 10 mL medium, please change the initial compartment size of Vmed and the corresponding assignment rule for Vmed.
initial Vmed = 1e-8 (1e6 cells in 10 mL medium)
Vmed = 0.010/(1e6*exp(log(1.45)*time/1440)) (1e6 cells in 10 mL medium)
3. Please note that this model contains events and the medium compartment size is varied.
4. For the model simulation in SBML-SAT, please remove initialAssignments and save it as SBML Level 2 Verion 1 file.
Project description:To identify differentially expressed long noncoding RNAs (lncRNAs) upon TGF-β stimulation in human cultured tubular epithelial cells HK2 and HKC8, we have employed long noncoding RNA microarray expression profiling as a discovery platform to find differentially expressed lncRNAs with TGF-β stimulation in these cells. Cultured human tubular epithelial cells HK2 and HKC8 were stimulated with PBS or TGF-β1. After incubation with TGF-β1 (10ng/ml) for 24 hours, 86 overlapping lncRNAs were upregulated and 47 overlapping lncRNAs were downregulated more than 2 fold vesus cells treated with PBS in these two epithelial cell lines. Expression of ENST00000429588 from this result was quantified in the same RNA samples by real-time PCR, confirming the upregulation upon TGF-β stimulation is repeatable.