2. Academic Validation
  3. Empagliflozin Attenuates Non-Alcoholic Fatty Liver Disease (NAFLD) in High Fat Diet Fed ApoE(-/-) Mice by Activating Autophagy and Reducing ER Stress and Apoptosis

Empagliflozin Attenuates Non-Alcoholic Fatty Liver Disease (NAFLD) in High Fat Diet Fed ApoE(-/-) Mice by Activating Autophagy and Reducing ER Stress and Apoptosis

  • Int J Mol Sci. 2021 Jan 15;22(2):818. doi: 10.3390/ijms22020818.
Narjes Nasiri-Ansari 1,  Chrysa Nikolopoulou 1,  Katerina Papoutsi 1,  Ioannis Kyrou 2 3 4,  Christos S Mantzoros 5 6,  Georgios Kyriakopoulos 1 7,  Antonios Chatzigeorgiou 8,  Vassiliki Kalotychou 9,  Manpal S Randeva 10,  Kamaljit Chatha 11,  Konstantinos Kontzoglou 12,  Gregory Kaltsas 13,  Athanasios G Papavassiliou 1,  Harpal S Randeva 2 10 14,  Eva Kassi 1 13
Affiliations

Affiliations

  • 1 Department of Biological Chemistry, Medical School, National and Kapodistrian University of Athens, 11527 Athens, Greece.
  • 2 Warwickshire Institute for the Study of Diabetes, Endocrinology and Metabolism (WISDEM), University Hospitals Coventry and Warwickshire NHS Trust, Coventry CV2 2DX, UK.
  • 3 Aston Medical Research Institute, Aston Medical School, Aston University, Birmingham B4 7ET, UK.
  • 4 Division of Biomedical Sciences, Warwick Medical School, University of Warwick, Coventry CV4 7AL, UK.
  • 5 Division of Endocrinology, Diabetes and Metabolism, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, MA 02215, USA.
  • 6 Section of Endocrinology, Boston VA Healthcare System, Harvard Medical School, Boston, MA 02215, USA.
  • 7 Department of Pathology, Evangelismos Hospital, 10676 Athens, Greece.
  • 8 Department of Physiology, Medical School, National and Kapodistrian University of Athens, 11527 Athens, Greece.
  • 9 1st Department of Internal Medicine, Laiko Hospital, Medical School, National and Kapodistrian University of Athens, 11527 Athens, Greece.
  • 10 Human Metabolism Research Unit, WISDEM Centre, NHS Trust, Coventry CV2 2DX, UK.
  • 11 Department of Biochemistry & Immunology, University Hospitals Coventry and Warwickshire NHS Trust, Coventry CV2 2DX, UK.
  • 12 Laboratory of Experimental Surgery and Surgical Research N.S. Christeas, Athens University Medical School, National and Kapodistrian University of Athens, 11527 Athens, Greece.
  • 13 Endocrine Oncology Unit, 1st Department of Propaupedic Internal Medicine, Laiko Hospital, National and Kapodistrian University of Athens, 11527 Athens, Greece.
  • 14 Division of Translational and Experimental Medicine-Metabolic and Vascular Health, Warwick Medical School, University of Warwick, Coventry CV4 7AL, UK.
PMID: 33467546 DOI: 10.3390/ijms22020818
Abstract

Aims/hypothesis: SGLT-2 inhibitors (SGLT-2i) have been studied as potential treatments against NAFLD, showing varying beneficial effects. The molecular mechanisms mediating these effects have not been fully clarified. Herein, we investigated the impact of empagliflozin on NAFLD, focusing particularly on ER stress, Autophagy and Apoptosis.

Methods: Five-week old ApoE(-/-) mice were switched from normal to a high-fat diet (HFD). After five weeks, mice were randomly allocated into a control group (HFD + vehicle) and Empa group (HFD + empagliflozin 10 mg/kg/day) for five weeks. At the end of treatment, histomorphometric analysis was performed in liver, mRNA levels of Fasn, Screbp-1, Scd-1, Ppar-γ, Pck-1, Mcp-1, Tnf-α, IL-6, F4/80, Atf4, Elf2α, Chop, Grp78, Grp94, Χbp1, Ire1α, ATF6, mTOR, Lc3b, Beclin-1, P62, Bcl-2 and Bax were measured by qRT-PCR, and protein levels of p-EIF2α, EIF2a, CHOP, LC3II, P62, BECLIN-1 and cleaved Caspase-8 were assessed by immunoblotting.

Results: Empagliflozin-treated mice exhibited reduced fasting glucose, total Cholesterol and triglyceride serum levels, as well as decreased NAFLD activity score, decreased expression of lipogenic enzymes (Fasn, Screbp-1c and Pck-1) and inflammatory molecules (Mcp-1 and F4/80), compared to the Control group. Empagliflozin significantly decreased the expression of ER stress molecules Grp78, Ire1α, Xbp1, Elf2α, Atf4, ATF6, Chop, P62(Sqstm1) and Grp94; whilst activating Autophagy via increased AMPK phosphorylation, decreased mTOR and increased LC3B expression. Finally, empagliflozin increased the Bcl2/Bax ratio and inhibited Caspase-8 cleavage, reducing liver cell Apoptosis. Immunoblotting analysis confirmed the qPCR results.

Conclusion: These novel findings indicate that empagliflozin treatment for five weeks attenuates NAFLD progression in ApoE(-/-) mice by promoting Autophagy, reducing ER stress and inhibiting hepatic Apoptosis.

Keywords

ER stress; NAFLD; SGLT-2 inhibitors; apoptosis; autophagy; inflammation.

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