mTORC1 promotes mineralization via p53 pathway
- 28 January 2021
- journal article
- research article
- Published by Wiley in The FASEB Journal
- Vol. 35 (2), e21325
- https://doi.org/10.1096/fj.202002016r
Abstract
The objectives of our study were to investigate the roles of mTORC1 in odontoblast proliferation and mineralization and to determine the mechanism by which mTORC1 regulates odontoblast mineralization. In vitro, MDPC23 cells were treated with rapamycin (10 nmol/L) and transfected with a lentivirus for short hairpin (shRNA)-mediated silencing of the tuberous sclerosis complex (shTSC1) to inhibit and activate mTORC1, respectively. CCK8 assays, flow cytometry, Alizarin red S staining, ALP staining, qRT-PCR, and western blot analysis were performed. TSC1-conditional knockout (DMP1-Cre(+); TSC1(f/f), hereafter CKO) mice and littermate control (DMP1-Cre(-); TSC1(f/f), hereafter WT) mice were generated. H&E staining, immunofluorescence, and micro-CT analysis were performed. Transcriptome sequencing analysis was used to screen the mechanism of this process. mTORC1 inactivation decreased the cell proliferation. The qRT-PCR and western blot results showed that mineralization-related genes and proteins were downregulated in mTORC1-inactivated cells. Moreover, mTORC1 overactivation promoted cell proliferation and mineralization-related gene and protein expression. In vivo, the micro-CT results showed that DV/TV and dentin thickness were higher in CKO mice than in controls and H&E staining showed the same results. Mineralization-related proteins expression was upregulated. Transcriptome sequencing analysis revealed that p53 pathway-associated genes were differentially expressed in TSC1-deficient cells. By inhibiting p53 alone or both mTORC1 and p53 with rapamycin and a p53 inhibitor, we elucidated that p53 acts downstream of mTORC1 and that mTORC1 thereby promotes odontoblast mineralization. Taken together, our findings demonstrate that the role of mTORC1 in odontoblast proliferation and mineralization, and confirm that mTORC1 upregulates odontoblast mineralization via the p53 pathway.Keywords
Funding Information
- National Natural Science Foundation of China (81970930)
- Key Research and Development Project of Hainan Province (201904010068)
This publication has 42 references indexed in Scilit:
- Biological and chemical studies on aryl hydrocarbon receptor induction by the p53 inhibitor pifithrin-α and its condensation product pifithrin-βLife Sciences, 2011
- Steady-State Kinetic and Inhibition Studies of the Mammalian Target of Rapamycin (mTOR) Kinase Domain and mTOR ComplexesBiochemistry, 2010
- S6K1 is a multifaceted regulator of Mdm2 that connects nutrient status and DNA damage responseThe EMBO Journal, 2010
- Transcriptional Regulation by P53Cold Spring Harbor Perspectives in Biology, 2010
- Point mutations in TOR confer Rheb-independent growth in fission yeast and nutrient-independent mammalian TOR signaling in mammalian cellsProceedings of the National Academy of Sciences of the United States of America, 2007
- Making a tooth: growth factors, transcription factors, and stem cellsCell Research, 2005
- Upstream and downstream of mTORGenes & Development, 2004
- TSC2 is phosphorylated and inhibited by Akt and suppresses mTOR signallingNature, 2002
- Rapamycin (AY-22,989), a new antifungal antibiotic. I. Taxonomy of the producing streptomycete and isolation of the active principle.The Journal of Antibiotics, 1975