The results of a new study show that mouse osteoblasts, bone generating cells, increase their consumption of glucose when deprived of oxygen. This uptick in glucose consumption results in high bone mass in addition to hypoglycemia and increased whole-body glucose tolerance. The study findings, published in The Journal of Clinical Investigation, could lead to improved therapies for osteoporosis and diabetes.
Current osteoporosis treatments aim to inhibit osteoclast activity, bone cells that breakdown bone, but most therapies also negatively impact osteoblasts, the cells responsible for building bone. This can lead to reduced bone quality and fractures that are difficult to heal in individuals with osteoporosis. The aim of the study was to investigate how to stimulate osteoblast activity in order to develop new drugs. It was known that a good blood supply is required for bone cells to work optimally but further understanding is still required. In order to investigate this, the researchers focused on the impact of oxygen from blood vessels that come in contact with bone.
In the experiment, mice were treated so their bones would behave as if they lacked oxygen. There were two key observations—the mice formed heavy bones and the bones absorbed large amounts of glucose. “That observation is in line with the usual response of cells to oxygen deprivation: they save on the consumption of oxygen by converting glucose to lactate instead of burning the glucose. No oxygen is needed for this conversion, but the downside is that it produces much less energy. In order to generate enough energy, the bone cells in our mice therefore take up much more glucose than normal, according to professor Christa Maes."
In addition, the mice remained thin even though they ate as much as the untreated mice and were even less physically active. Blood tests showed that their blood sugar levels were much lower than normal mice. The two observations are most likely related. The treated mice absorbed more glucose into their bones so there was less glucose in their bloodstream. An increased bone metabolism can have a positive impact on systemic blood glucose levels and can lead to a leaner physique. More research is needed to transform these findings into potential treatments for both osteoporosis and diabetes.