Related Experiment Video
Updated: May 10, 2026
11:52
Differentiation of Functional Osteoclasts from Human Peripheral Blood CD14+ Monocytes
Published on: January 27, 2023
Osteoclasts in RA: diverse origins and functions
Benoit Le Goff1, Jean-Marie Berthelot, Yves Maugars
1Service de rhumatologie, Hôtel-Dieu, 1, place Alexis-Ricordeau, 44093 Nantes cedex 1, France; LUNAM université, 44000 Nantes, France; Inserm, UMR957, physiopathologie de la résorption osseuse et thérapie des tumeurs osseuses primitives, 44035 Nantes, France; Université de Nantes, Nantes atlantique universités, 44035 Nantes, France.
Joint Bone Spine
|June 5, 2013
Summary
Osteoclasts, key to rheumatoid arthritis bone loss, have diverse origins and functions beyond resorption. Emerging evidence suggests they may also drive autoimmune responses and antigen presentation.
Area of Science:
- Immunology
- Rheumatology
- Cell Biology
- Bone Biology
Background:
- Osteoclasts are recognized as primary mediators of bone loss in rheumatoid arthritis (RA).
- Recent findings reveal significant diversity in osteoclast origins and functions, challenging previous understandings.
- The role of osteoclasts extends beyond bone resorption to potentially influence inflammatory and autoimmune processes.
Purpose of the Study:
- To explore the evolving concepts of osteoclast biology in the context of rheumatoid arthritis.
- To investigate the diverse origins and functions of osteoclasts in RA pathogenesis.
- To examine the potential role of osteoclasts in immune responses, including antigen presentation.
Main Methods:
- Review of recent evidence on osteoclast biology and function.
- Analysis of osteoclast progenitor origins in rheumatoid synovium and subchondral bone.
- Investigation of osteoclast activation pathways in inflamed rheumatoid tissues.
- Examination of potential antigen-presenting capabilities of osteoclasts.
Main Results:
- Osteoclast progenitors in RA can originate from circulating cells or local tissues like the synovium and subchondral bone.
- Activated osteoclasts in inflamed synovium respond to cytokines, immune complexes, and toll-like receptor activators.
- Emerging data suggest osteoclasts may present antigens to T cells via MHC class I and II molecules.
Conclusions:
- Osteoclast biology is complex, with diverse roles in rheumatoid arthritis beyond bone resorption.
- Osteoclasts may actively participate in inflammatory and autoimmune responses, including antigen presentation.
- Understanding the intricate bone-immune system interactions may reveal novel therapeutic targets for RA-associated bone abnormalities.
Related Concept Videos
01:30Bone Cells and Tissue
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 periosteum and...
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 periosteum and...
01:31Osteoclasts 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...
01:40Bone Remodeling
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.
01:22The Functions of the Skeletal System
The most apparent functions of the skeletal system are support, protection, and movement. However, bone tissue also performs several other critical metabolic functions. For one, the bone matrix acts as a reservoir for a number of minerals important to the functioning of the body, especially calcium and phosphorus. These minerals, present in the bone tissue, can be released back into the bloodstream when required. Calcium ions, for example, are essential for muscle contractions and controlling...
01:23Bone as Supporting Connective Tissue
Bone tissue forms the internal skeleton of vertebrate animals, providing structure to the body.
Bone Matrix
Bone, or osseous tissue, is a connective tissue that has a large amount of two different types of matrix material. The organic matrix is similar to the matrix material found in other connective tissues, including some amount of collagen and elastic fibers. This gives strength and flexibility to the tissue. The inorganic matrix consists of mineral salts— mostly calcium salts— that give the...
Bone Matrix
Bone, or osseous tissue, is a connective tissue that has a large amount of two different types of matrix material. The organic matrix is similar to the matrix material found in other connective tissues, including some amount of collagen and elastic fibers. This gives strength and flexibility to the tissue. The inorganic matrix consists of mineral salts— mostly calcium salts— that give the...
01:27Compact Bone
Most bones contain compact and spongy osseous tissue, but their distribution and concentration vary based on the bone's overall function.
Compact bone, also called cortical bone, is the denser, stronger of the two types of bone tissue. It is found under the periosteum and in the diaphyses of long bones, where it provides support and protection. The microscopic structural unit of compact bone is called an osteon, or haversian system. Each osteon is composed of concentric rings of calcified...
Compact bone, also called cortical bone, is the denser, stronger of the two types of bone tissue. It is found under the periosteum and in the diaphyses of long bones, where it provides support and protection. The microscopic structural unit of compact bone is called an osteon, or haversian system. Each osteon is composed of concentric rings of calcified...