Related Experiment Video

Updated: Jun 12, 2026

Skeletal Phenotype Analysis of a Conditional Stat3 Deletion Mouse Model
08:42

Skeletal Phenotype Analysis of a Conditional Stat3 Deletion Mouse Model

Published on: July 3, 2020

Serotonergic 5-HT(2B) receptor controls tissue-nonspecific alkaline phosphatase activity in osteoblasts via

Anne Baudry1, Juliette Bitard, Sophie Mouillet-Richard

  • 1Cellules Souches, Signalisation et Prions, INSERM U747, Université Paris Descartes, Paris, France.

The Journal of Biological Chemistry
|June 25, 2010
PubMed

Insights

The serotonin-2B receptor (5-HT2BR) regulates bone health by controlling tissue-nonspecific alkaline phosphatase (TNAP) activity. This receptor influences TNAP post-translationally through prostaglandins and leukotrienes during osteoblast differentiation.

Area of Science:

  • Bone biology
  • Cell signaling
  • Receptor pharmacology

Background:

  • The serotonin-2B receptor (5-HT2BR) plays a role in maintaining bone homeostasis.
  • Previous studies indicated defects in bone homeostasis in mice lacking 5-HT2BR.
  • The downstream molecular mechanisms of 5-HT2BR's anabolic function in osteoblasts require elucidation.

Purpose of the Study:

  • To identify downstream targets of the serotonin-2B receptor (5-HT2BR) involved in its anabolic function in osteoblasts.
  • To establish a functional link between 5-HT2BR and tissue-nonspecific alkaline phosphatase (TNAP) activity during osteogenic differentiation.
  • To investigate the role of eicosanoids in mediating 5-HT2BR's regulation of TNAP.

Main Methods:

  • Utilized the C1 osteoprogenitor cell line for in vitro studies.
  • Employed pharmacological inhibition and shRNA-mediated knockdown to assess 5-HT2BR function.
  • Measured mRNA translation, protein activity, and eicosanoid synthesis (prostaglandins, leukotrienes).
  • Investigated downstream signaling pathways including phospholipase A2 and phosphatidylinositol-specific phospholipase C.

Main Results:

  • 5-HT2BR and TNAP mRNA translation are delayed relative to extracellular matrix deposition during C1 osteogenic differentiation.
  • 5-HT2BR constitutively controls TNAP activity post-translationally, independent of its mRNA translation.
  • Pharmacological inhibition or knockdown of 5-HT2BR prevents TNAP activation.
  • Agonist stimulation of 5-HT2BR enhances TNAP activity during early mineralization.
  • 5-HT2BR regulates leukotriene synthesis via phospholipase A2 at later differentiation stages.
  • Prostaglandins and leukotrienes mediate post-translational TNAP activation via phosphatidylinositol-specific phospholipase C.
  • Primary calvarial osteoblasts from 5-HT2BR-null mice show impaired TNAP activity.

Conclusions:

  • The serotonin-2B receptor (5-HT2BR) is a key regulator of tissue-nonspecific alkaline phosphatase (TNAP) activity in osteoblasts.
  • 5-HT2BR exerts post-translational control over TNAP activity through distinct prostaglandin and leukotriene signaling pathways during osteogenesis.
  • These findings reveal novel molecular mechanisms by which 5-HT2BR influences bone anabolic function.

More Related Videos

Peptides from Phage Display Library Modulate Gene Expression in Mesenchymal Cells and Potentiate Osteogenesis in Unicortical Bone Defects07:53

Peptides from Phage Display Library Modulate Gene Expression in Mesenchymal Cells and Potentiate Osteogenesis in Unicortical Bone Defects

Published on: December 10, 2010

Related Concept Videos

Transducer Mechanism: Enzyme-Linked Receptors01:27

Transducer Mechanism: Enzyme-Linked Receptors

Enzyme-linked receptors are cell-surface receptors acting as an enzyme or associating with an enzyme intracellularly. They make excellent drug targets. Drugs can bind to the extracellular ligand-binding domain or directly affect their enzymatic domain and alter their activity.
Major types that are helpful drug targets include:
Hormones and Bone Tissue01:17

Hormones and Bone Tissue

The endocrine system produces and secretes hormones, which interact with the skeletal system. These hormones control bone growth, maintain bone once it is formed, and remodel it.
Hormones That Influence Osteoblasts and/or Maintain the Matrix
Several hormones are necessary for controlling bone growth and maintaining the bone matrix. The pituitary gland secretes growth hormone (GH), which, as its name implies, controls bone growth. This happens in several ways: first, it triggers chondrocyte...
Osteoclasts in Bone Remodeling01:31

Osteoclasts in Bone Remodeling

Osteoclasts are cells responsible for bone resorption and remodeling. They originate from hematopoietic progenitor cells present in the bone marrow. Numerous progenitor cells fuse to form multinucleated cells, each with 10-20 nuclei. A single osteoclast has a diameter of 150 to 200 µM. These cells have ruffled borders that break down the underlying bone tissue and release minerals such as calcium into the blood in bone resorption. Osteoclasts cling to bones with their ruffled edges during bone...
Protein Kinases and Phosphatases02:54

Protein Kinases and Phosphatases

Proteins undergo chemical modifications that trigger changes in the charge, structure, and conformation of the proteins. Phosphorylation, acetylation, glycosylation, nitrosylation, ubiquitination, lipidation, methylation, and proteolysis are various protein modifications that regulate protein activity. Such modifications are usually enzyme-driven.
Protein kinases
Many proteins in the cell are regulated by phosphorylation, the addition of a phosphate group. A family of enzymes called kinases...
TGF - β Signaling Pathway01:16

TGF - β Signaling Pathway

The TGF-β signaling pathway regulates cell growth, differentiation, adhesion, motility, and development. TGF-β ligands that induce TGF-β signaling are synthesized in their latent form. Several proteases or cell surface receptors such as integrins act upon the latent form, releasing the active ligand. There are three types of mammalian TGF-βs: (TGF-β1, TGF-β2, and TGF-β3) that bind as homodimers or heterodimers to TGF-β receptors. The TGF-β receptors are of three kinds RI, RII, and RIII. The RI...
Amplifying Signals via Second Messengers01:15

Amplifying Signals via Second Messengers

Many receptor binding ligands are hydrophilic; they do not cross the cell membrane but bind to cell-surface receptors. Thus, their message must be relayed by second messengers present in the cell cytoplasm. There are several second messenger pathways, each with its own way of relaying information. For example, the G protein-coupled receptors can activate both phosphoinositol and cyclic AMP (cAMP) second messenger pathways. The phosphoinositol pathway is active when the receptor induces...