Related Experiment Video

Updated: Jan 9, 2026

Author Spotlight: Developing a Rat Model for Weight-Bearing Intervention to Investigate Osteonecrosis of the Femoral Head
05:55

Author Spotlight: Developing a Rat Model for Weight-Bearing Intervention to Investigate Osteonecrosis of the Femoral Head

Published on: September 27, 2024

892

Glucocorticoid impairs angiogenesis-dependent osteogenesis by downregulating EphB4 in endothelial cells

Qinghua Ren1, Xing Rong1, Ting Liu1

  • 1Department of Bone Metabolism, School and Hospital of Stomatology, Cheeloo College of Medicine, Shandong University & Shandong Key Laboratory of Oral Tissue Regeneration & Shandong Engineering Research Center of Dental Materials and Oral Tissue Regeneration & Shandong Provincial Clinical Research Center for Oral Diseases, Jinan, China; Center of Osteoporosis and Bone Mineral Research, Shandong University, Jinan, China.

Biochemical Pharmacology
|December 4, 2025
PubMed

Insights

Glucocorticoid-induced osteoporosis (GIOP) involves impaired blood vessel function. This study reveals that dexamethasone downregulates Ephrin type-B receptor 4 (EphB4), disrupting blood vessel formation and bone health.

Area of Science:

  • Endocrinology
  • Vascular Biology
  • Bone Biology

Background:

  • Glucocorticoids (GCs) cause osteoporosis by impairing bone microarchitecture and blood vessel function.
  • The specific mechanisms linking impaired type H blood vessel function to glucocorticoid-induced osteoporosis (GIOP) are not fully understood.

Purpose of the Study:

  • To investigate the role of Ephrin type-B receptor 4 (EphB4) in dexamethasone (DEX)-induced osteoporosis.
  • To elucidate the mechanisms by which DEX affects angiogenesis-osteogenesis coupling.

Main Methods:

  • Utilized a dexamethasone (DEX)-induced GIOP mouse model.
  • Performed co-culture experiments with bone marrow mesenchymal stem cells (BMSCs) and endothelial cells (ECs) overexpressing EphB4.
  • Investigated the Wnt/β-catenin pathway's role in DEX-mediated EphB4 downregulation.

Main Results:

  • DEX treatment reduced type H blood vessels and EphB4 expression in the GIOP mouse model.
  • Endothelial EphB4 is crucial for angiogenesis-dependent osteogenesis, and DEX downregulates it.
  • DEX-induced EphB4 downregulation promoted endothelial cell senescence and impaired BMSC osteogenic differentiation.
  • Reduced EphB4-EphrinB2 crosstalk and Wnt/β-catenin pathway activation were implicated in DEX's effects.

Conclusions:

  • EphB4 plays a critical role in regulating angiogenesis-osteogenesis coupling, and its downregulation by DEX contributes to GIOP.
  • DEX-induced endothelial cell senescence and impaired BMSC differentiation are key mechanisms in GIOP pathogenesis.
  • Targeting the EphB4 pathway offers a potential therapeutic strategy for GIOP.
Keywords:
BMSCEndothelial cellEphB4Glucocorticoid-induced osteoporosisSenescenceType H blood vessels

More Related Videos

Computed Tomography and Optical Imaging of Osteogenesis-angiogenesis Coupling to Assess Integration of Cranial Bone Autografts and Allografts13:16

Computed Tomography and Optical Imaging of Osteogenesis-angiogenesis Coupling to Assess Integration of Cranial Bone Autografts and Allografts

Published on: December 22, 2015

11.9K
Visualizing Angiogenesis by Multiphoton Microscopy In Vivo in Genetically Modified 3D-PLGA/nHAp Scaffold for Calvarial Critical Bone Defect Repair09:34

Visualizing Angiogenesis by Multiphoton Microscopy In Vivo in Genetically Modified 3D-PLGA/nHAp Scaffold for Calvarial Critical Bone Defect Repair

Published on: September 7, 2017

9.8K

Related Concept Videos

Regulation of Angiogenesis and Blood Supply01:24

Regulation of Angiogenesis and Blood Supply

Rapidly dividing tumors, embryos, and wounded tissues require more oxygen than usual, lowering the oxygen concentration in the blood. At low oxygen or hypoxic conditions, an oxygen-sensitive transcription factor called the hypoxia-inducible factor 1 or HIF1 is activated. HIF1 is a dimeric protein of alpha (ɑ) and beta (β) subunits.  Under optimal oxygen conditions, HIF1β is present in the nucleus while HIF1ɑ remains in the cytosol. HIF1ɑ is hydroxylated by prolyl...
3.3K
Mechanism of Angiogenesis01:10

Mechanism of Angiogenesis

Blood vessel formation starts early during embryonic development, around day 7. In the extraembryonic yolk sac, mesodermal precursor cells called hemangioblast proliferate and differentiate into angioblast. Angioblasts express vascular endothelial growth factor receptor 2 or VEGFR2, which binds VEGF-A, a proangiogenic factor, guiding blood vessel formation. VEGF signaling promotes angioblasts to form a blood island in the developing embryo. Angioblasts further differentiate, giving rise to...
6.6K
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...
10.4K
Cell Specific Gene Expression01:58

Cell Specific Gene Expression

Multicellular organisms contain a variety of structurally and functionally distinct cell types, but the DNA in all the cells originated from the same parent cells. The differences in the cells can be attributed to the differential gene expression. Liver cells, whose functions include detoxification of blood, production of bile to metabolize fats, and synthesis of proteins essential for metabolism, must express a specific set of genes to perform their functions. Gene expression also varies with...
16.2K
Receptor Downregulation in MVBs01:15

Receptor Downregulation in MVBs

Multivesicular bodies (MVBs) are mature endosomes that sort ubiquitinated proteins and then fuse with lysosomes to degrade the sorted proteins. Epidermal growth factor (EGF) and its receptor (EGFR) form a complex that can be internalized through endocytosis, sorted into an MVB, and later degraded.
The EGFR can initiate signaling pathways that  lead to cell proliferation, migration, and differentiation. Overexpression of EGFR  stimulates cells to proliferate. Excessive  EGFR...
2.7K