The Changing Roles of Bone Remodeling Biomarkers

Introduction

Bones are traditionally known for their support, protection and movement properties, as well as their role in the processes of mineral balance and blood cell production. Research supports that bones do more than they were originally recognized for. Previous research investigating osteocalcin not only helped to change the scientific community’s understanding of bones, but also increased the use of bone remodeling biomarkers in other fields of study.

Overview of Bone Remodeling

Bone remodeling (also known as bone metabolism) refers to the process of old bone being destroyed and then replaced with new bone. It is a continuous cycle of growth and resorption that is carefully orchestrated by bone cells, hormones, and cell signaling molecules. Multiple regulatory systems are used to keep bone remodeling balanced including the RANKL/RANK/OPG system^1,2. Imbalances in bone metabolism can lead to bone diseases.

Bone Remodeling Biomarkers

The functions of bones now cover a multitude of areas. As such, traditional bone remodeling biomarkers are aiding in discoveries across various research areas.

Osteocalcin (OC)

OC is a hormone synthesized in the bones by osteoblasts, as well as a marker of bone formation.  Recent research on OC has linked the hormone to both fertility and energy homeostasis functions^3-5. Previous research investigating OC not only helped to increase the use of bone remodeling biomarkers in other fields of study.

OPG and sRANKL

Recent research has shown both OPG and sRANKL to be more than just regulators of bone metabolism. Evidence suggests OPG and sRANKL are involved in type 2 diabetes and multiple forms of cancer^6-8.

Sclerostin

Sclerostin is produced and secreted by osteocytes within the Wnt signaling pathway, thus regulating bone formation. Research on sclerostin and diabetes has contributed toward supporting evidence of bones having endocrine functions^9,10.

Dickkopf-1 (DKK-1)

DKK-1 is a known bone remodeling biomarker acting as an inhibitor of the Wnt signaling pathway and regulating bone metabolism. Recent research illustrates the involvement of DKK-1 in tumourgenetic activity among multiple cancers^11,12.

Osteopontin (OPN)

OPN is a protein produced in bone and plays a vital role in the differentiation of osteoclasts, regulation of calcium deposits, and enhancement of osteoclast activity. OPN has gained interest in many other research areas including cardiovascular and cancer research^13,14.

Periostin (Postn)

Postn is a protein expressed by osteoblasts required for sclerostin inhibition, making it a necessity to the overall regulation of bone metabolism¹⁵. Research has shown postn to also be involved in various diseases such as asthma¹⁶.

Conclusion

Previous research investigating osteocalcin not only helped to change the scientific community’s understanding of bones, but also increased the use of bone biomarkers in other fields of study. Now bone remodeling biomarkers have the potential to be used in the study of other disease areas and could even aid in the development of new disease therapies.

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References

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