Convergence of TGFβ and BMP signaling in regulating human bone marrow stromal cell differentiation

Sci Rep. 2019 Mar 21;9(1):4977. doi: 10.1038/s41598-019-41543-0.

Abstract

Targeting regulatory signaling pathways that control human bone marrow stromal (skeletal or mesenchymal) stem cell (hBMSC) differentiation and lineage fate determination is gaining momentum in the regenerative medicine field. Therefore, to identify the central regulatory mechanism of osteoblast differentiation of hBMSCs, the molecular phenotypes of two clonal hBMSC lines exhibiting opposite in vivo phenotypes, namely, bone forming (hBMSC+bone) and non-bone forming (hBMSC-Bone) cells, were studied. Global transcriptome analysis revealed significant downregulation of several TGFβ responsive genes, namely, TAGLN, TMP1, ACTA2, TGFβ2, SMAD6, SMAD9, BMP2, and BMP4 in hBMSC-Bone cells and upregulation on SERPINB2 and NOG. Transcriptomic data was associated with marked reduction in SMAD2 protein phosphorylation, which thereby implies the inactivation of TGFβ and BMP signaling in those cells. Concordantly, activation of TGFβ signaling in hBMSC-Bone cells using either recombinant TGFβ1 protein or knockdown of SERPINB2 TGFβ-responsive gene partially restored their osteoblastic differentiation potential. Similarly, the activation of BMP signaling using exogenous BMP4 or via siRNA-mediated knockdown of NOG partially restored the differentiation phenotype of hBMSC-Bone cells. Concordantly, recombinant NOG impaired ex vivo osteoblastic differentiation of hBMSC+Bone cells, which was associated with SERBINB2 upregulation. Our data suggests the existence of reciprocal relationship between TGFB and BMP signaling that regulates hBMSC lineage commitment and differentiation, whilst provide a plausible strategy for generating osteoblastic committed cells from hBMSCs for clinical applications.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adipocytes / cytology
  • Adipocytes / drug effects
  • Adipocytes / metabolism
  • Adipogenesis / drug effects
  • Bone Morphogenetic Protein 4 / metabolism*
  • Cell Differentiation* / drug effects
  • Cell Line
  • Clone Cells
  • Down-Regulation / drug effects
  • Gene Silencing / drug effects
  • Humans
  • Mesenchymal Stem Cells / cytology*
  • Mesenchymal Stem Cells / drug effects
  • Mesenchymal Stem Cells / metabolism*
  • Osteoblasts / cytology
  • Osteoblasts / drug effects
  • Osteoblasts / metabolism
  • Osteogenesis / drug effects
  • Serpins / metabolism
  • Signal Transduction* / drug effects
  • Transforming Growth Factor beta / metabolism*
  • Transforming Growth Factor beta1 / pharmacology

Substances

  • Bone Morphogenetic Protein 4
  • Serpins
  • Transforming Growth Factor beta
  • Transforming Growth Factor beta1