In
obesity and diabetes, adipocytes show significant endoplasmic reticulum (ER) stress.
Hyperglycemia-induced ER stress has not been studied in adipocyte differentiation and
adipokine expression.
Taurine has been known to protect the cells against ER stress. This study examined the effect of
taurine on ER stress-induced adipocyte differentiation and
adipokine expression to explain the
therapeutic effect of
taurine on diabetes and
obesity. To do this, human preadipocytes were differentiated into adipocytes, in the presence or absence of
taurine, under ER stress conditions. Changes in
adipokine expression in adipocytes stimulated with IL-1β were investigated in the presence or absence of
taurine. Human preadipocytes were treated with
thapsigargin (10 nM) or high
glucose concentrations (100 mM) as ER stress inducers during differentiation into adipocytes.
Thapsigargin inhibited the differentiation of adipocytes in a dose-dependent manner, but the high
glucose concentration treatment did not.
Taurine 100 mM treatment did not block the inhibition of differentiation of preadipcytes into adipocytes. Furthermore, the high
glucose concentration treatment inhibited the expression of
adiponectin and increased the expression of
leptin in human adipocytes. However,
taurine treatment did not affect the expression of two
adipokines. In conclusion, the therapeutic mechanism of
taurine in diabetes and
obesity does not appear to occur by alleviating
hyperglycemia-mediated ER stress. To clarify the molecular mechanism by which
taurine improves diabetic symptoms and
obesity in animal models, the protective effect of
taurine against
hyperglycemia- or
overnutrition-mediated ER stress should be further evaluated under various conditions or types of ER stress.