Glycolipid toxicity induces osteogenic dysfunction via the TLR4/S100B pathway

Int Immunopharmacol. 2021 Aug:97:107792. doi: 10.1016/j.intimp.2021.107792. Epub 2021 May 26.

Abstract

Diabetes can cause bone metabolism disorders and osteoporosis. The occurrence of both diabetes mellitus and osteoporosis increases the disability and mortality of elderly individuals due to pathological fracture. Abnormal metabolism of nutrientsis considered to be one of the important mechanisms of diabetes mellitus-induced osteoporosis. This study preliminarily explored the roles of TLR4 (Toll-like receptor 4) and S100B in osteogenic dysfunction induced by glycolipid toxicity. In this study, a diabetic rat model and TLR4-knockdown diabetic rat model were used in vivo. MC3T3-E1 cells in a high glucose and palmitic acid environment were used as glycolipid toxicity cell models in vitro. We investigated the effects of TLR4 and S100B on osteogenesis by overexpression or inhibition of TLR4 and S100B in vitro. We found that when TLR4 or S100B was inhibited, ALP and OCN were significantly up-regulated and p-ERK was significantly down regulated in the glycolipid model. These results suggest that TLR4/S100B may play a role in reducing glycolipid toxicity by regulating ERK phosphorylation.

Keywords: Glycolipid toxicity; Osteogenic dysfunction; TLR4/S100B.

MeSH terms

  • Animals
  • Bone Density
  • Cell Differentiation
  • Cell Line
  • Diabetes Mellitus, Experimental / chemically induced
  • Diabetes Mellitus, Experimental / complications
  • Diabetes Mellitus, Experimental / metabolism
  • Diabetes Mellitus, Type 2 / chemically induced
  • Diabetes Mellitus, Type 2 / complications*
  • Diabetes Mellitus, Type 2 / metabolism
  • Diet, High-Fat / adverse effects
  • Down-Regulation
  • Gene Knockdown Techniques
  • Glycolipids / metabolism*
  • Humans
  • Male
  • Mice
  • Osteoblasts / pathology
  • Osteogenesis
  • Osteoporosis / etiology
  • Osteoporosis / metabolism*
  • Osteoporosis / pathology
  • Phosphorylation
  • Rats
  • S100 Calcium Binding Protein beta Subunit / genetics
  • S100 Calcium Binding Protein beta Subunit / metabolism*
  • Signal Transduction
  • Streptozocin / administration & dosage
  • Streptozocin / toxicity
  • Toll-Like Receptor 4 / genetics
  • Toll-Like Receptor 4 / metabolism*

Substances

  • Glycolipids
  • S100 Calcium Binding Protein beta Subunit
  • S100b protein, mouse
  • S100b protein, rat
  • Tlr4 protein, mouse
  • Tlr4 protein, rat
  • Toll-Like Receptor 4
  • Streptozocin