Àá½Ã¸¸ ±â´Ù·Á ÁÖ¼¼¿ä. ·ÎµùÁßÀÔ´Ï´Ù.
KMID : 1141520240390020353
Endocrinology and Metabolism
2024 Volume.39 No. 2 p.353 ~ p.363
Docosahexanoic Acid Attenuates Palmitate-Induced Apoptosis by Autophagy Upregulation via GPR120/mTOR Axis in Insulin-Secreting Cells
Hong Seok-Woo

Lee Jin-Mi
Moon Sun-Joon
Kwon Hye-Mi
Park Se-Eun
Rhee Eun-Jung
Lee Won-Young
Abstract
Background Polyunsaturated fatty acids (PUFAs) reportedly have protective effects on pancreatic ¥â-cells; however, the underlying mechanisms are unknown.

Methods To investigate the cellular mechanism of PUFA-induced cell protection, mouse insulinoma 6 (MIN6) cells were cultured with palmitic acid (PA) and/or docosahexaenoic acid (DHA), and alterations in cellular signaling and apoptosis were examined.

Results DHA treatment remarkably repressed caspase-3 cleavage and terminal deoxynucleotidyl transferase-mediated UTP nick end labeling (TUNEL)-positive red dot signals in PA-treated MIN6 cells, with upregulation of autophagy, an increase in microtubule-associated protein 1-light chain 3 (LC3)-II, autophagy-related 5 (Atg5), and decreased p62. Upstream factors involved in autophagy regulation (Beclin-1, unc51 like autophagy activating kinase 1 [ULK1], phosphorylated mammalian target of rapamycin [mTOR], and protein kinase B) were also altered by DHA treatment. DHA specifically induced phosphorylation on S2448 in mTOR; however, phosphorylation on S2481 decreased. The role of G protein-coupled receptor 120 (GPR120) in the effect of DHA was demonstrated using a GPR120 agonist and antagonist. Additional treatment with AH7614, a GPR120 antagonist, significantly attenuated DHA-induced autophagy and protection. Taken together, DHA-induced autophagy activation with protection against PA-induced apoptosis mediated by the GPR120/mTOR axis.

Conclusion These findings indicate that DHA has therapeutic effects on PA-induced pancreatic ¥â-cells, and that the cellular mechanism of ¥â-cell protection by DHA may be a new research target with potential pharmacotherapeutic implications in ¥â-cell protection.
KEYWORD
Docosahexaenoic acids, Autophagy, Insulin-secreting cells, G-protein-coupled receptor
FullTexts / Linksout information
Listed journal information