Tgfβ signaling stimulates glycolysis to promote the genesis of synovial joint interzone in developing mouse embryonic limbs

Sci Adv. 2025 Jan 10;11(2):eadq4991. doi: 10.1126/sciadv.adq4991. Epub 2025 Jan 8.

Abstract

The initial interzone cells for synovial joints originate from chondrocytes, but such critical transition is minimally understood. With single-cell RNA sequencing (scRNA-seq) of murine embryonic knee joint primordia, we discovered that heightened expression of glycolysis genes characterized developing interzone cells when compared to flanking chondrocytes. Conditional deletion of the glucose transporters Glut1 and/or Glut3, in either the incipient pre-skeletal mesenchyme with Prx1Cre or in chondrocytes with Col2Cre, disrupted interzone formation dose-dependently. In contrast, deletion of Glut1/3 in established interzone cells with Gdf5Cre did not have similar severe disruption of joint development. scRNA-seq revealed that Glut1/3 deletion by Prx1Cre impeded Tgfβ signaling in the developing interzone cells. Direct elimination of Tgfβ signaling with Prx1Cre partially phenocopied the deletion of Glut1/3 in impairing interzone formation. Tgfβ stimulated glycolysis in chondrocytes via activation of mTOR and Hif1α in vitro. The data support that the essential conversion of chondrocytes to interzone cells requires a transient elevation of glycolysis partly dependent on Tgfβ signaling.

MeSH terms

  • Animals
  • Chondrocytes* / cytology
  • Chondrocytes* / metabolism
  • Embryo, Mammalian / metabolism
  • Glucose Transporter Type 1* / genetics
  • Glucose Transporter Type 1* / metabolism
  • Glucose Transporter Type 3* / genetics
  • Glucose Transporter Type 3* / metabolism
  • Glycolysis*
  • Homeodomain Proteins
  • Hypoxia-Inducible Factor 1, alpha Subunit / genetics
  • Hypoxia-Inducible Factor 1, alpha Subunit / metabolism
  • Mice
  • Signal Transduction*
  • TOR Serine-Threonine Kinases / metabolism
  • Transforming Growth Factor beta* / metabolism

Substances

  • Transforming Growth Factor beta
  • Glucose Transporter Type 3
  • Glucose Transporter Type 1
  • Slc2a1 protein, mouse
  • Slc2a3 protein, mouse
  • Hypoxia-Inducible Factor 1, alpha Subunit
  • TOR Serine-Threonine Kinases
  • Hif1a protein, mouse
  • Prrx1 protein, mouse
  • mTOR protein, mouse
  • Homeodomain Proteins