Effects of nicotine on the metabolism and gene expression profile of Sprague‑Dawley rat primary osteoblasts

Abstract

Smoking is a risk factor associated with bone and oral diseases, particularly periodontitis. Nicotine, the major toxic component of tobacco, is able to affect the quality and quantity of bone. Osteoblasts serve an important role in bone formation. Thus far, the effects of nicotine on metabolism-associated gene and protein expression in osteoblasts have been controversial and the mechanisms remain unclear. The present study assessed alterations in osteogenic activity by performing a Cell Counting kit-8 assay to investigate proliferation, Annexin V-fluorescein isothiocyanate/propidium iodide staining to investigate apoptosis, alizarin red staining to investigate the formation of mineralized nodules, reverse transcription-quantitative polymerase chain reaction and western blotting to investigate the mRNA and protein levels of collagen I, alkaline phosphatase, bone osteocalcin, bone sialoprotein and osteopontin; and mRNA microarray expression analysis, Kyoto Encyclopedia of Genes and Genomes and Gene Ontology analysis to investigate the whole genome expression profile of Sprague-Dawley (SD) rat primary osteoblasts following treatment with different concentrations of nicotine. The results demonstrated that nicotine inhibited proliferation, promoted early apoptosis and inhibited mineralized nodule formation in a dose-dependent manner by regulating alkaline phosphatase activity and the expression of osteoblast metabolism-associated genes and proteins. According to microarray analysis, several genes associated with bone metabolism and genes in the Hedgehog and Notch signaling pathways were downregulated significantly in nicotine-treated osteoblasts. The results of the present study indicated that nicotine may serve an inhibitory, dose-dependent role in SD rat primary osteoblasts that may be caused by the perturbation of genes and signaling pathways associated with bone formation. These results may provide a theoretical basis for future research regarding bone metabolism and targeted treatment of oral diseases associated with smoking.

Flaxseed oil ameliorated high-fat-diet-induced bone loss in rats by promoting osteoblastic function in rat primary osteoblasts

“…Primary OBs were isolated from the skulls of newly born (72 h) SD rats. The standardized extraction procedure of primary OBs was carried as previously described [21, 22]. The cells were collected and dissolved in DME/F-12 1:1 culture medium (HyClone) supplemented with 10% foetal bovine serum (Excel), penicillin-streptomycin mixed liquor (Solarbio) and incubated in a humidified atmosphere of 95% air and 5% CO2 at 37 °C.…”

Tobacco‐induced suppression of the vascular response to dental plaque

“…Although smoking has effects on multiple biological systems that may predispose to chronic periodontitis—including amplification of cholinergic anti‐inflammatory signaling, a reduced antibody response, suppressed immune cell function, promotion of osteoclast/osteoblast imbalance, a depleted antioxidant defense, and compromised tissue remodeling—this review will focus specifically on the vascular response itself.…”

The Role of Tocotrienol in Preventing Male Osteoporosis—A Review of Current Evidence

“…In vitro studies showed that one of the major components of cigarette smoke, nicotine, decreased the formation of osteoblasts from human bone marrow mesenchymal stem cells [88]. Another study demonstrated that proliferation and formation of mineralized nodules were reduced in rat primary osteoblasts [89]. Gene expression analysis on these cells revealed two pathways related to bone metabolism affected by nicotine, i.e., Hedgehog and Notch pathways [89].…”

“…Another study demonstrated that proliferation and formation of mineralized nodules were reduced in rat primary osteoblasts [89]. Gene expression analysis on these cells revealed two pathways related to bone metabolism affected by nicotine, i.e., Hedgehog and Notch pathways [89]. Other studies found that the effects of nicotine on osteogenesis might be bi-phasic in nature, whereby negative impacts were only observed with high doses [90].…”