Related Experiment Video
Updated: Dec 9, 2025
Estrogen-Like Effect of Bazi Bushen Capsule in Ovariectomized Rats
Published on: April 7, 2023
Infraphysiological 17β-estradiol (E2) concentration compromises osteoblast differentiation through Src stimulation of
Sarah Maria Barneze Costa1, Georgia da Silva Feltran2, Vickeline Namba1
1Experimental Research Unit, School of Medicine of Botucatu (FMB), Sao Paulo State University (UNESP), Botucatu, 18618-970, Sao Paulo State, Brazil.
Abstract:
It has been shown that 17β-estradiol (E2) helps to prevent bone loss. This study was undertaken to verify whether E2 action in human osteoblasts involves changes in the transcriptional profile of the TNF-α, IFN-γ, NF-κB, TRAIL, TGF-β, MMP2, MMP9, RECK, TIMP1, TIMP2, CDK2, CDK4, SRC, RUNX2, and SHH genes. Infraphysiological doses of E2 elevated mRNAs in all genes except for INF-γ, TRAIL, and TGF-β. Importantly, a significant increase in the CDKs -2 and -4 genes was found, which strongly suggests cell cycle progression, with a potential dependency of Src involvement, as well as a suppression of the osteoblast differentiation machinery, with ECM remodeling being involved. These data suggest that E2 plays an important role in bone formation and remodeling, and Src seems to play a pivotal role in driving cell proliferation and ECM remodeling. Taken together, these findings contribute to an understanding of the effects of infraphysiological E2 on modulating bone homeostasis, favoring bone resorption, and leading to osteoporosis.
Insights
Low-dose 17β-estradiol (E2) impacts human osteoblasts, increasing cell cycle genes and suppressing bone formation markers. This suggests E2 may favor bone resorption, potentially contributing to osteoporosis.
Area of Science:
- Endocrinology
- Molecular Biology
- Bone Biology
Background:
- 17β-estradiol (E2) is known to prevent bone loss.
- The precise molecular mechanisms of E2 action in osteoblasts require further elucidation.
Purpose of the Study:
- To investigate the effects of infraphysiological E2 doses on the transcriptional profile of key genes in human osteoblasts.
- To understand E2's role in bone formation, remodeling, and osteoporosis development.
Main Methods:
- Human osteoblasts were treated with infraphysiological doses of E2.
- Quantitative real-time PCR was used to measure mRNA levels of selected genes, including those involved in inflammation, cell cycle, differentiation, and extracellular matrix (ECM) remodeling.
Main Results:
- E2 treatment elevated mRNA levels for most tested genes, excluding IFN-γ, TRAIL, and TGF-β.
- Significant increases in Cyclin-Dependent Kinase (CDK) 2 and CDK4 gene expression were observed, indicating cell cycle progression.
- Suppression of osteoblast differentiation markers and modulation of ECM remodeling genes (MMP2, MMP9, RECK, TIMP1, TIMP2) were noted, with a potential role for Src.
Conclusions:
- Infraphysiological E2 influences osteoblast gene expression, promoting cell proliferation and ECM remodeling.
- E2 appears to suppress osteoblast differentiation, potentially favoring bone resorption and contributing to osteoporosis.
- Src kinase may play a critical role in mediating E2's effects on proliferation and ECM remodeling in bone cells.
More Related Videos
08:48An In Vitro Dormancy Model of Estrogen-sensitive Breast Cancer in the Bone Marrow: A Tool for Molecular Mechanism Studies and Hypothesis Generation
Published on: June 30, 2015
06:47Isolation of Mesenchymal Stem Cells from Human Alveolar Periosteum and Effects of Vitamin D on Osteogenic Activity of Periosteum-derived Cells
Published on: May 4, 2018
Related Concept Videos
01:31Osteoclasts in Bone Remodeling
01:40Bone Remodeling
01:27Feedback Regulation of Calcium Concentration
Various transmembrane receptors, such as G protein-coupled receptors (GPCRs), elicit a response to extracellular signals by increasing cytosolic calcium. Activated GPCRs...