Stem cells could help halt osteoporosis, promote bone growth

Investigators from the Research Institute of the McGill University Health Centre in Montreal reported that tweaking mesenchymal stem cells with interferon (IFN) gamma may promote bone growth, according to a new study published in the journal Stem Cells.

“We have identified a new pathway, centered on IFN gamma, that controls the bone remodeling process both in vivo and in vitro,” Richard Kremer, MD, the study’s lead author and co-director of the Musculoskeletal Axis of the McGill University Health Centre, said in a press release. “[Additional] studies are required to describe it more precisely, but we are hopeful that it could lead to a better understanding of the underlying causes of osteoporosis, as well as to innovative treatments.”

From cell culture to animal model

Kremer, a professor with McGill's Faculty of Medicine, said in the press release, “First, we stimulated cultured mesenchymal stem cells to turn into bone cells (ie, osteoblasts) in vitro. We realized that this differentiation process involved IFN gamma-related genes, but also that these bone cells precursors could both be stimulated by IFN gamma and produced IFN gamma."

The next step was to move to an animal model, where IFN gamma effect is blocked by inactivating its receptor, a model called IFN gamma receptor knock-out, Kremer said in the press release.

The researchers conducted bone density tests, comparable to those used to diagnose people with osteoporosis. The results revealed that these animals have significantly lower bone mass than their healthy counterparts. Likewise, the mesenchymal stem cells have a decreased ability to make bone, according to the press release.

“These findings confirm that IFN gamma is an integral factor for mesenchymal stem cells’ differentiation into osteoblasts, also in vivo,” Kremer said in the press release.

New biological pathway

Both in vitro and in vivo results proved that IFN gamma is key to the differentiation of mesenchymal cells into bone cells, and to growth process of the bone. Meanwhile, the exact pathway by which IFN acts on bone cells’ formation will require more research, but the strict correlation highlighted in this study underscores its importance, he said in the press release.

Until now, IFN gamma has been mostly used as an agent to prevent infections and to reinforce the immune system from illnesses such as cancer. “These findings provide hope that IFN gamma itself, or another molecule involved in its pathway, could soon also become an efficient drug-target for an antidote for osteoporosis,” he said in the press release.

Reference:
Kremer R, Duque G, Huang DC, et al. Autocrine regulation of interferon-y in mesenchymal stem cells plays a role in early osteoblastogenesis. Stem Cells. 27;2:886.