Tauroursodeoxycholate, a Chemical Chaperone, Prevents Palmitate-induced Apoptosis in Pancreatic β-cells by Reducing ER Stress

Q. Zhu; J. J. Zhong; J. F. Jin; X. M. Yin; H. Miao

doi:10.1055/s-0032-1321787

Experimental and Clinical Endocrinology & Diabetes, Table of Contents

Exp Clin Endocrinol Diabetes 2013; 121(01): 43-47
DOI: 10.1055/s-0032-1321787

Article

Tauroursodeoxycholate, a Chemical Chaperone, Prevents Palmitate-induced Apoptosis in Pancreatic β-cells by Reducing ER Stress

Q. Zhu^*

¹Department of Endocrinology, The Second Affiliated Hospital of Nanjing Medical University, Nanjing, China

,

J. J. Zhong

²Department of Endocrinology, Zhejiang Province Hospital of Traditional Chinese Medicine, The First Affiliated Hospital, Zhejiang University of Chinese Medicine, Hangzhou, China

,

J. F. Jin

³Laboratory of Liver Injury and Repair Molecular Medicine, Guilin Medical University, Guilin, China

,

X. M. Yin

¹Department of Endocrinology, The Second Affiliated Hospital of Nanjing Medical University, Nanjing, China

,

H. Miao

¹Department of Endocrinology, The Second Affiliated Hospital of Nanjing Medical University, Nanjing, China

› Author Affiliations

Abstract

Background:

Free fatty acids (FFA) can have deleterious effects on β-cells and promote type 2 diabetes, a process known as lipotoxicity. Recently, the induction of endoplasmic reticulum (ER) stress is one mechanism proposed to contribute to the detrimental effects of FFA on β-cells. Tauroursodeoxycholic acid (TUDCA) has been reported to show cytoprotective effects by alleviating ER stress induced by some cytotoxic stimuli. The aim of this study was to investigate the effects of TUDCA on FFA (palmitate)-induced apoptosis and ER stress in rat islet β-cells.

Methods:

The rat pancreatic β-cell line INS-1 was cultured with palmitate (0.5 mM), or cultured togther with TUDCA (100 μM), Annexin V-fluorescein-isothiocyanate/propidium iodide flow cytometry was used to assess apoptosis in INS-1 cells. Cell viability was evaluated with MTT reduction conversion assay. The expressions of ER stress marker GRP78, ER stress-associated pro-apoptotic effectors CHOP and ATF4 were detected by Western blotting.

Results:

TUDCA significantly reduced palmitate-induced cell apoptosis and growth inhibition in INS-1 cells. TUDCA also attenuated palmitate-induced expressions of GRP78, CHOP and ATF4 in INS-1 cells.

Conclusions:

Our results thus suggested that TUDCA could protect INS-1 cells from palmitate-induced injury, which might be due to the amelioration of ER stress and blocking the ATF4/CHOP signaling pathway.

Key words

β-cells - ER stress - apoptosis - palmitate - tauroursodeoxycholic acid

Full Text

References

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