By taking their microscopes to the skeletal structures of the human body, scientists in Australia have unearthed an entirely new type of bone cell, one they believe may play an important role in the development of various bone diseases. The new cell switches on a number of unique genes, shedding new light on the way bones degenerate and reform and opening up new possibilities for the treatment of conditions like osteoporosis.
As part of our natural bone development, special cells on the surface break down old bone tissue and then build it back up again. When changes occur to this cycle and throw things off balance, conditions like bone fragility and osteoporosis can take hold, but the different cells involved in this process could offer novel ways to intervene.
Among those is a cell type called osteoclasts, which are specialized cells involved in breaking down bone tissue and served as the starting point for the researchers at the University of New South Wales (UNSW). They used what’s known as intravital imaging technology to take a look deep inside living bone tissue, where they found that the osteoclasts actually divided up into even smaller cells, before reforming into osteoclasts again.
“This process was completely new to us,” says Dr Michelle McDonald, first author of the paper describing the research. “The consensus until now has been that osteoclasts undergo cell death after they’ve done their job, but we saw they were recycling by splitting up and joining back together again, a process which we hypothesize may increase their lifespan. We also found these cells in the blood and bone marrow, suggesting they can travel to other parts of the skeleton, as a likely ‘reserve’ of cells that are ready to fuse and deploy when osteoclasts are needed again.”
To further understand these newly discovered cells, the team used RNA sequencing to establish their genetic profile, which only piqued the scientists’ interest further.