Related Experiment Video
Updated: Nov 16, 2025
07:03
A Simple Pit Assay Protocol to Visualize and Quantify Osteoclastic Resorption In Vitro
Published on: June 16, 2022
6.8K
Osteoclasts recycle via osteomorphs during RANKL-stimulated bone resorption.
Michelle M McDonald1, Weng Hua Khoo1, Pei Ying Ng2
1Healthy Ageing Theme, Garvan Institute of Medical Research, Sydney, NSW, Australia; St. Vincent's Clinical School, Faculty of Medicine, UNSW Sydney, NSW, Australia.
Cell
|February 26, 2021
Summary
Osteoclasts, the bone-resorbing cells, can recycle into new cells called osteomorphs. This discovery offers potential new targets for treating bone diseases.
Area of Science:
- Cell Biology
- Skeletal Biology
- Osteoclast Biology
Background:
- Osteoclasts are multinucleated cells responsible for bone resorption.
- They are derived from monocyte/macrophage precursors.
- Osteoclasts were previously thought to undergo apoptosis after bone resorption.
Purpose of the Study:
- To investigate the fate of osteoclasts after bone resorption.
- To identify alternative cell fates beyond apoptosis.
- To explore the potential therapeutic targets for skeletal diseases.
Main Methods:
- Intravital imaging to observe osteoclast behavior in vivo.
- RANKL stimulation and inhibition experiments.
- Single-cell RNA sequencing to analyze gene expression in daughter cells.
- Genetic analysis of human orthologs.
Main Results:
- Osteoclasts undergo fission into daughter cells named osteomorphs.
- RANKL inhibition prevents osteoclast recycling and causes osteomorph accumulation.
- Osteomorphs are transcriptionally distinct from osteoclasts and macrophages.
- Osteomorph genes are linked to skeletal disorders and bone mineral density.
Conclusions:
- Osteoclasts have an alternative recycling pathway via osteomorphs.
- Osteomorphs play a role in regulating bone resorption.
- Osteomorphs represent a potential therapeutic target for skeletal diseases.
Related Concept Videos
01:31Osteoclasts in Bone Remodeling
3.5K
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...
3.5K
01:40Bone Remodeling
39.4K
Bone remodeling is a continuous and balanced process of bone resorption by osteoclasts and bone formation by osteoblasts. In adults, it helps maintain bone mass and calcium homeostasis. While mechanical stress can stimulate turnover as part of the normal maintenance and reparative process, several hormones also regulate bone remodeling.
39.4K
01:30Bone Cells and Tissue
7.2K
Bones contain a relatively small number of cells entrenched in a matrix of organic and inorganic components. Although bone cells compose only a small amount of the bone volume, they are crucial to its function. Four types of cells are found within the bone tissue— osteoblasts, osteocytes, osteogenic cells, and osteoclasts.
Osteoblasts and Osteocytes
The osteoblast is the bone cell responsible for forming new bone tissue. It is found in the growing portions of bone, including the...
Osteoblasts and Osteocytes
The osteoblast is the bone cell responsible for forming new bone tissue. It is found in the growing portions of bone, including the...
7.2K
01:17Hormones and Bone Tissue
3.3K
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...
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...
3.3K
01:21Skeleton and Calcium Homeostasis
5.3K
Calcium is not only the most abundant mineral in bone but also the most abundant mineral in the human body. Calcium ions are needed for bone mineralization, tooth health, heart rate regulation and strength of contraction, blood coagulation, the contraction of smooth and skeletal muscle cells, and the regulation of nerve impulse conduction. The average calcium level in the blood is about 10 mg/dL. When the body cannot maintain this level, a person will experience hypo or hypercalcemia.
5.3K
01:18The Bone Matrix
5.1K
Bone contains a relatively small number of cells entrenched in a matrix of collagen fibers that provide an adherent surface for inorganic salt crystals. Both components of the matrix, organic and inorganic, contribute to the unusual properties of bone. Without collagen, bones would be brittle and shatter easily. Without mineral crystals, bones would flex and provide little support. This can be observed by an experiment: when the minerals of a bone are dissolved by soaking the bone in...
5.1K