Low bone accrual is associated with osteocyte apoptosis in alcohol-induced osteopenia

IntroductionAlcohol is known to decrease bone mineral density (BMD) and to induce trabecular microarchitecture deterioration. However, little is known about the effects of chronic alcohol consumption on osteocytes in situ. The aim of this study was to assess the effects of a high alcohol dose on osteocytes in an alcohol-induced osteopenia model.Materials and methods24 male Wistar rats, 2-months old were separated in 2 groups: Control (C) or Alcohol (A35). The rats in the A35 group drank a beverage composed of 35% ethanol v/v mixed to water for 17 weeks. BMD was assessed by DXA, while the microarchitecture was analyzed using μCT. Bone remodeling was studied measuring serum concentration of osteocalcin, NTx and TRAP. Bone marrow adiposity, osteoblastic lineage differentiation, osteocyte morphology and apoptosis were assessed using bright field, epifluorescence, transmission electron and confocal microscopy.ResultsBMD, trabecular thickness, TRAP and NTx concentration were significantly decreased in A35, while cortical thickness was thinner. There were 10 fold more cells stained with cleaved caspase-3, and 35% more empty lacunae in A35, these data indicating a large increase in osteocyte apoptosis in the A35 group. The number of lipid droplets in the marrow was increased in A35 (7 fold). Both the osteocyte apoptosis and the fat bone marrow content strongly correlated with femur BMD (p = 0.0017, r = − 0.72 and p = 0.002, r = − 0.70) and whole body BMD.ConclusionThese data suggest that low BMD is associated with osteocyte apoptosis and bone marrow fat content in alcohol-induced osteopenia.

► Chronic alcohol consumption decreases bone density through bone remodeling imbalance. ► Little is known about the effect of alcohol on osteocyte. ► We assessed the effects of alcohol on bone density, osteocyte apoptosis, morphology and on marrow fat content. ► We found increased osteocyte apoptosis and marrow fat content, which were inversely correlated to the low BMD. ► Alcohol-induced osteopenia is linked to osteocyte apoptosis and increased marrow fat content.