Study Demonstrates Mitochondrial Potential for Bone Disease Prevention and Treatment

South Korea: Seoul National University researchers have discovered that mitochondria, the energy-producing organelles in cells, can improve bone formation.

Led by Prof Yunsil Lee of Seoul National University Graduate School of Dentistry, the study conducted animal experiments to observe changes in mitochondria in osteoblasts, cells responsible for bone formation. The team hypothesized that mitochondria could be actively secreted outside of cells during bone formation.

Donut-like Formation

By creating genetically modified mice that expressed fluorescent proteins only in the mitochondria of osteoblasts, the team was able to observe dynamic changes in mitochondria during bone formation. They found that activating osteoblast cells caused mitochondria to change shape into a donut-like form before dividing and secreting outside of cells.

Prof Yun-Sil Lee said, “By confirming through animal experiments that bone regeneration is promoted when mitochondria secreted from osteoblasts are transplanted into bone defects, we suggest the possibility that osteoblast-derived mitochondria can be developed as an osteogenesis promoter.

“Most of the osteopenia drugs use the mechanism of inhibiting bone resorption, and these types of drugs require drug treatment for a certain period of time to reduce side effects, followed by a drug break. It can be used as an alternative to osteoblasts, and it is expected that osteoblast-derived mitochondria can be used as a therapeutic agent for that purpose.”

Prof Yunsil Lee, Seoul National University Graduate School of Dentistry

Doctoral student Joon-ho Seo (co-first author) said, “Generally, mitochondria are known as an organ that produces energy necessary for cells, but in this study, in addition to these functions, mitochondria create their own endoplasmic reticulum and secrete it out of the cell to differentiate the surrounding cells.

“By identifying a new biological mechanism that promotes cell growth, we have expanded our understanding of mitochondrial function.”

These secreted mitochondria then promote differentiation of osteoblast cells in the surrounding bone precursor cells.

Mitochondria May Help Reduce Risk of Bone-related Illnesses

The research, which was published in the February issue of the journal Cell Metabolism and selected as a cover article (pictured), suggests that mitochondria can be used to prevent and treat bone diseases as well as develop agents that promote bone formation.

Further research could explore the possibilities of developing drugs that enhance mitochondrial division to increase bone formation and reduce the risk of bone-related illnesses.

Read the full article: Mitochondrial fragmentation and donut formation enhance mitochondrial secretion to promote osteogenesis.