Equine silicate associated osteoporosis bone marrow and tracheobronchial lymph node transcriptome

Horses with pulmonary silicosis resulting from exposure to soil-derived silicate dioxide dust (e.g., cristobalite) are prone to develop osteoporosis. The comorbid condition has been termed silicate associated osteoporosis (SAO) because post-mortem examination of horses with osteoporosis consistently reveals chronic granulomatous pneumonia and/or tracheobronchial lymphadenitis with intralesional silicate crystals. Osteoporosis manifests with skeletal deformities and fatal pathologic bone fractures. Osteoporosis commonly affects the axial and proximal appendicular skeletal sites rich in hematopoietic bone marrow (BM). We predicted that SAO affected horses will have altered transcriptome patterns in the BM and tracheobronchial lymph nodes when compared with unaffected horses. The SAO transcriptome pattern should provide clues to the mechanism of SAO.