High glucose-induced inhibition of osteoblast like MC3T3-E1 differentiation promotes mitochondrial perturbations.
Claudia MedeirosJoseph M WallacePublished in: PloS one (2022)
Diabetes mellitus is a metabolic disorder that causes health concerns worldwide. Patients with diabetes exhibit multisystemic symptoms, including loss of bone quality over time. The progressive deterioration of bone promotes failure to withstand damage and increases the risk of fractures. Much of the molecular and metabolic mechanism(s) in diabetic bone remains unclear. In vitro studies suggest that hyperglycemia inhibits mineralization, affecting bone formation and function. In this study, inhibition of osteoblast differentiation was induced using hyperglycemia to assess whether high glucose promotes mitochondrial impairment along with altered bone matrix formation. It was hypothesized that bone energy metabolism would be altered in these cells as calcium deposition, a key phase for bone function, is suppressed. Early passages of osteoblast like MC3T3-E1 cells were differentiated under normal and high glucose conditions. To investigate osteoblast differentiation, we quantified calcium accumulation by alizarin red staining and analyzed immunoblots of key proteins. To assess mitochondrial function, we quantified mitochondrial DNA (mtDNA), detected expression and function of key proteins from the Tricarboxylic (TCA) cycle, measured mitochondrial respiration, and fuel oxidation of alternative nutrients. Results confirmed previous work showing that mineralization was inhibited and AKT expression was reduced in high glucose-treated bone cells. Unexpectedly, high glucose-treated osteoblast cells utilize both mitochondrial respiration and glycolysis to maintain energy demands with partial help of fatty acid for reliance of baseline bioenergetics. These metabolic shifts suggest that hyperglycemia maintain bone metabolic needs in an early differentiated state concurrent to the inhibition in bone matrix formation.
Keyphrases
- high glucose
- endothelial cells
- bone regeneration
- bone mineral density
- induced apoptosis
- oxidative stress
- soft tissue
- cell cycle arrest
- bone loss
- healthcare
- postmenopausal women
- poor prognosis
- diabetic rats
- squamous cell carcinoma
- fatty acid
- copy number
- nitric oxide
- public health
- endoplasmic reticulum stress
- adipose tissue
- rectal cancer
- metabolic syndrome
- depressive symptoms
- long non coding rna
- risk assessment
- quality improvement
- dna methylation
- insulin resistance
- health information