Osteoblasts are specialized bone cells responsible for building and regenerating bone tissue. Researchers at Leipzig University have shown that a specific receptor plays a key role in the strength of bone cells—and how this receptor can be selectively activated. These findings could pave the way for the development of new medications with fewer side effects to help strengthen bones and muscles in aging patients. The research has been published in the journal Signal Transduction and Targeted Therapy.
There is a high demand for safe and long-lasting medications to treat bone loss, known medically as osteoporosis. In Germany, around six million people—mostly women—are affected by this widespread condition. Discovering new targets for drug development is therefore a key step toward better therapies with fewer side effects. The adhesion G protein-coupled receptor GPR133 belongs to a still relatively unexplored group of receptors. In a recent study, scientists at Leipzig University demonstrated that GPR133 plays a central role in building and maintaining healthy bone.
“If this receptor is impaired by genetic changes, mice show signs of loss of bone density at an early age—similar to osteoporosis in humans. Using the substance AP503, which was only recently identified via a computer-assisted screen as a stimulator of GPR133, we were able to significantly increase bone strength in both healthy and osteoporotic mice,” explains Professor Ines Liebscher, lead investigator of the study from the Rudolf Schönheimer Institute of Biochemistry at the Faculty of Medicine.
In bone tissue, GPR133 is activated through the interaction of neighboring bone cells and mechanical strain. This triggers a signal that stimulates bone-forming cells (osteoblasts) and inhibits bone-resorbing cells (osteoclasts). The result: stronger, more resilient bones. The new active substance AP503 can mimic this natural activation. In the future, it could be used both to further strengthen healthy bones and to rebuild weakened ones—for instance, in cases of osteoporosis in women going through menopause.
Great potential for an aging population
In an earlier study, researchers at Leipzig University had already found that activation with AP503 also strengthens skeletal muscle.
“The newly demonstrated parallel strengthening of bone once again highlights the great potential this receptor holds for medical applications in an aging population,” says Dr. Juliane Lehmann, lead author of the study and a researcher at the Rudolf Schönheimer Institute of Biochemistry.
The Leipzig research team is already working on several follow-up projects to explore the use of AP503 in various diseases and to further investigate the role of GPR133 in the body.
More information:
Juliane Lehmann et al, The mechanosensitive adhesion G protein-coupled receptor 133 (GPR133/ADGRD1) enhances bone formation, Signal Transduction and Targeted Therapy (2025). DOI: 10.1038/s41392-025-02291-y
Citation:
Key receptor for bone cell strength and regeneration identified (2025, July 28)
retrieved 28 July 2025
from https://medicalxpress.com/news/2025-07-key-receptor-bone-cell-strength.html
This document is subject to copyright. Apart from any fair dealing for the purpose of private study or research, no
part may be reproduced without the written permission. The content is provided for information purposes only.
Osteoblasts are specialized bone cells responsible for building and regenerating bone tissue. Researchers at Leipzig University have shown that a specific receptor plays a key role in the strength of bone cells—and how this receptor can be selectively activated. These findings could pave the way for the development of new medications with fewer side effects to help strengthen bones and muscles in aging patients. The research has been published in the journal Signal Transduction and Targeted Therapy.
There is a high demand for safe and long-lasting medications to treat bone loss, known medically as osteoporosis. In Germany, around six million people—mostly women—are affected by this widespread condition. Discovering new targets for drug development is therefore a key step toward better therapies with fewer side effects. The adhesion G protein-coupled receptor GPR133 belongs to a still relatively unexplored group of receptors. In a recent study, scientists at Leipzig University demonstrated that GPR133 plays a central role in building and maintaining healthy bone.
“If this receptor is impaired by genetic changes, mice show signs of loss of bone density at an early age—similar to osteoporosis in humans. Using the substance AP503, which was only recently identified via a computer-assisted screen as a stimulator of GPR133, we were able to significantly increase bone strength in both healthy and osteoporotic mice,” explains Professor Ines Liebscher, lead investigator of the study from the Rudolf Schönheimer Institute of Biochemistry at the Faculty of Medicine.
In bone tissue, GPR133 is activated through the interaction of neighboring bone cells and mechanical strain. This triggers a signal that stimulates bone-forming cells (osteoblasts) and inhibits bone-resorbing cells (osteoclasts). The result: stronger, more resilient bones. The new active substance AP503 can mimic this natural activation. In the future, it could be used both to further strengthen healthy bones and to rebuild weakened ones—for instance, in cases of osteoporosis in women going through menopause.
Great potential for an aging population
In an earlier study, researchers at Leipzig University had already found that activation with AP503 also strengthens skeletal muscle.
“The newly demonstrated parallel strengthening of bone once again highlights the great potential this receptor holds for medical applications in an aging population,” says Dr. Juliane Lehmann, lead author of the study and a researcher at the Rudolf Schönheimer Institute of Biochemistry.
The Leipzig research team is already working on several follow-up projects to explore the use of AP503 in various diseases and to further investigate the role of GPR133 in the body.
More information:
Juliane Lehmann et al, The mechanosensitive adhesion G protein-coupled receptor 133 (GPR133/ADGRD1) enhances bone formation, Signal Transduction and Targeted Therapy (2025). DOI: 10.1038/s41392-025-02291-y
Citation:
Key receptor for bone cell strength and regeneration identified (2025, July 28)
retrieved 28 July 2025
from https://medicalxpress.com/news/2025-07-key-receptor-bone-cell-strength.html
This document is subject to copyright. Apart from any fair dealing for the purpose of private study or research, no
part may be reproduced without the written permission. The content is provided for information purposes only.
