iNOS expression and osteocyte apoptosis in idiopathic, non-traumatic osteonecrosis.

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Wang J, Kalhor A, Lu S, Crawford R, Ni JD, Xiao Y

iNOS expression and osteocyte apoptosis in idiopathic, non-traumatic osteonecrosis.

Acta Orthop. 2015 Feb;86(1):134-41. doi: 10.3109/17453674.2014.960997. Epub 2014 Sep 5.

PubMed ID

25191931 [ View in PubMed

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Abstract

BACKGROUND AND PURPOSE: Non-traumatic osteonecrosis is a progressive disease with multiple etiologies. It affects younger individuals more and more, often leading to total hip arthroplasty. We investigated whether there is a correlation between inducible nitric oxide synthase (iNOS) expression and osteocyte apoptosis in non-traumatic osteonecrosis. PATIENTS AND METHODS: We collected and studied 20 human idiopathic, non-traumatic osteonecrosis femoral heads. Subchondral bone samples in the non-sclerotic region (n = 30), collected from osteoarthritis patients, were used as controls. Spontaneously hypertensive rats were used as a model for osteonecrosis in the study. We used scanning electron microscopy, TUNEL assay, and immunohistochemical staining to study osteocyte changes and apoptosis. RESULTS: The morphology of osteocytes in the areas close to the necrotic region changed and the number of apoptotic osteocytes increased in comparison with the same region in control groups. The expression of iNOS and cytochrome C in osteocytes increased while Bax expression was not detectable in osteonecrosis samples. Using spontaneously hypertensive rats, we found a positive correlation between iNOS expression and osteocyte apoptosis in the osteonecrotic region. iNOS inhibitor (aminoguanidine) added to the drinking water for 5 weeks reduced the production of iNOS and osteonecrosis compared to a control group without aminoguanidine. INTERPRETATION: Our findings show that increased iNOS expression can lead to osteocyte apopotosis in idiopathic, non-traumatic osteonecrosis and that an iNOS inhibitor may prevent the progression of the disease.

DrugBank Data that Cites this Article

Drug Targets

Drug	Target	Kind	Organism	Pharmacological Action	Actions
Pimagedine	Nitric oxide synthase, inducible	Protein	Humans	Yes	Inhibitor Downregulator	Details