Tumor necrosis factors have been known to be implicated in osteoporosis for several years, but the specific pathways by which TNF works in the disease are being elucidated only just now. A paper published in the latest Proceedings of the National Academy of Sciences establishes the role of TNF produced by T cells in osteoporosis.

Researchers at Washington University in St. Louis looked at the interaction of this TNF with one of its receptors in mice, tying estrogen deficiency to osteoporosis via this pathway. The data showed ovariectomized mice had increased T cell-derived TNF in the bone marrow, leading to rapid bone loss. In contrast, ovariectomized TNF-deficient mice were protected against bone resorption and bone loss.