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The effect of PPARγ agonist on SGLT2 and glucagon expressions in alpha cells under hyperglycemia

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Abstract

Background

Although sodium glucose cotransporter 2 (SGLT2) inhibitors have many beneficial effects for type 2 diabetes, including decreased cardiovascular death, recent reports that they increased glucagon through SGLT2 inhibition raised some concern. Troglitazone, Peroxisome proliferator-activated receptor γ (PPAR-γ) agonist, was reported to increase SGLT2 in renal proximal tubule cells, but its role on pancreatic alpha cells have not been reported. We investigated the effect of troglitazone on SGLT2 expression in alpha cells and subsequent glucagon regulation in hyperglycemia.

Methods

An Alpha TC1-6 cell line was cultured in control (5 mM) or hyperglycemia (HG, 15 mM) for 72 h. We applied troglitazone with or without PPARγ antagonist (GW9662 10 μM). To investigate the involvement of PI3K/Akt pathway, we applied troglitazone with or without Wortmanin. We measured sodium glucose transporter 2 (SGLT2) and glucagon (GCG) mRNA and protein expression. PPAR gamma, PI3K and Akt protein were also measured.

Results

Exposure of alpha TC cells to HG for 72 h increased glucagon mRNA and protein expression. HG decreased SGLT2 mRNA and protein expression. Troglitazone significantly reversed HG-induced reduction of SGLT2 expression and increase of glucagon secretion. PPARγ antagonist (GW9662 10 μM) decreased the expression of SGLT2 and increased glucagon as HG did. Hyperglycemia increased PI3K and pAkt expression in alpha cells. Wortmanin (PI3K inhibitor, 1 μM) reversed HG-induced SGLT2 decrease and glucagon increase. Troglitazone treatment decreased PI3K and pAkt expression in HG.

Conclusion

In conclusion, PPARγ agonist, troglitazone improved glucose transport SGLT2 dysfunction and subsequent glucagon dysregulation in alpha cell under hyperglycemia. Those effects were through the involvement of PI3K/pAkt signaling pathway. This study may add one more reason for the ideal combination of PPARγ agonist and SGLT2 inhibitor in clinical practice.

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References

  1. Unger RH, Cherrington AD (2012) Glucagonocentric restructuring of diabetes: a pathophysiologic and therapeutic makeover. J Clin Investig 122:4–12

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  2. Ferrannini E, Muscelli E, Frascerra S, Baldi S, Mari A et al (2014) Metabolic response to sodium-glucose cotransporter 2 inhibition in type 2 diabetic patients. J Clin Investig 124:499–508

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  3. Merovci A, Solis-Herrera C, Daniele G, Eldor R, Fiorentino TV et al (2014) Dapagliflozin improves muscle insulin sensitivity but enhances endogenous glucose production. J Clin Investig 124:509–514

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  4. Zinman B, Wanner C, Lachin JM, Fitchett D, Bluhmki E et al (2015) Empagliflozin, cardiovascular outcomes, and mortality in type 2 diabetes. N Engl J Med 373:2117–2128

    Article  CAS  PubMed  Google Scholar 

  5. Seino S, Shibasaki T, Minami K (2011) Dynamics of insulin secretion and the clinical implications for obesity and diabetes. J Clin Investig 121:2118–2125

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  6. Gromada J, Franklin I, Wollheim CB (2007) Alpha-cells of the endocrine pancreas: 35 years of research but the enigma remains. Endocr Rev 28:84–116

    Article  CAS  PubMed  Google Scholar 

  7. Ishihara H, Maechler P, Gjinovci A, Herrera PL, Wollheim CB (2003) Islet beta-cell secretion determines glucagon release from neighbouring alpha-cells. Nat Cell Biol 5:330–335

    Article  CAS  PubMed  Google Scholar 

  8. Rorsman P, Berggren PO, Bokvist K, Ericson H, Mohler H et al (1989) Glucose-inhibition of glucagon secretion involves activation of GABAA-receptor chloride channels. Nature 341:233–236

    Article  CAS  PubMed  Google Scholar 

  9. Cheng-Xue R, Gomez-Ruiz A, Antoine N, Noel LA, Chae HY et al (2013) Tolbutamide controls glucagon release from mouse islets differently than glucose: involvement of K(ATP) channels from both alpha-cells and delta-cells. Diabetes 62:1612–1622

    Article  PubMed  PubMed Central  Google Scholar 

  10. de Heer J, Rasmussen C, Coy DH, Holst JJ (2008) Glucagon-like peptide-1, but not glucose-dependent insulinotropic peptide, inhibits glucagon secretion via somatostatin (receptor subtype 2) in the perfused rat pancreas. Diabetologia 51:2263–2270

    Article  CAS  PubMed  Google Scholar 

  11. Sherck SM, Shiota M, Saccomando J, Cardin S, Allen EJ et al (2001) Pancreatic response to mild non-insulin-induced hypoglycemia does not involve extrinsic neural input. Diabetes 50:2487–2496

    Article  CAS  PubMed  Google Scholar 

  12. Shen XX, Li HL, Pan L, Hong J, Xiao J et al (2012) Glucotoxicity and alpha cell dysfunction: involvement of the PI3K/Akt pathway in glucose-induced insulin resistance in rat islets and clonal alphaTC1-6 cells. Endocr Res 37:12–24

    Article  CAS  PubMed  Google Scholar 

  13. Bonner C, Kerr-Conte J, Gmyr V, Queniat G, Moerman E et al (2015) Inhibition of the glucose transporter SGLT2 with dapagliflozin in pancreatic alpha cells triggers glucagon secretion. Nat Med 21:512–517

    Article  CAS  PubMed  Google Scholar 

  14. Ahmadian M, Suh JM, Hah N, Liddle C, Atkins AR et al (2013) PPARgamma signaling and metabolism: the good, the bad and the future. Nat Med 19:557–566

    Article  CAS  PubMed  Google Scholar 

  15. Kim HI, Kim JW, Kim SH, Cha JY, Kim KS et al (2000) Identification and functional characterization of the peroxisomal proliferator response element in rat GLUT2 promoter. Diabetes 49:1517–1524

    Article  CAS  PubMed  Google Scholar 

  16. Lee YJ, Han HJ (2010) Troglitazone ameliorates high glucose-induced EMT and dysfunction of SGLTs through PI3K/Akt, GSK-3beta, Snail1, and beta-catenin in renal proximal tubule cells. Am J Physiol Renal Physiol 298: F1263–1275.

  17. Miki T, Liss B, Minami K, Shiuchi T, Saraya A et al (2001) ATP-sensitive K + channels in the hypothalamus are essential for the maintenance of glucose homeostasis. Nat Neurosci 4:507–512

    CAS  PubMed  Google Scholar 

  18. Ostenson CG (1979) Regulation of glucagon release: effects of insulin on the pancreatic A2-cell of the guinea pig. Diabetologia 17:325–330

    Article  CAS  PubMed  Google Scholar 

  19. Starke A, Imamura T, Unger RH (1987) Relationship of glucagon suppression by insulin and somatostatin to the ambient glucose concentration. J Clin Invest 79:20–24

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  20. Han HJ, Choi HJ, Park SH (2000) High glucose inhibits glucose uptake in renal proximal tubule cells by oxidative stress and protein kinase C. Kidney Int 57:918–926

    Article  CAS  PubMed  Google Scholar 

  21. Rosenstock J, Ferrannini E (2015) Euglycemic diabetic ketoacidosis: a predictable, detectable, and preventable safety concern with SGLT2 inhibitors. Diabetes Care 38:1638–1642

    Article  CAS  PubMed  Google Scholar 

  22. Dormandy JA, Charbonnel B, Eckland DJ, Erdmann E, Massi-Benedetti M et al (2005) Secondary prevention of macrovascular events in patients with type 2 diabetes in the PROactive Study (PROspective pioglitAzone Clinical Trial In macroVascular Events): a randomised controlled trial. Lancet 366:1279–1289

    Article  CAS  PubMed  Google Scholar 

  23. DeFronzo RA, Chilton R, Norton L, Clarke G, Ryder RE et al. (2016) Revitalization of pioglitazone: the optimal agent to be combined with an SGLT2 inhibitor. Diabetes Obes Metab 18:454–462

    Article  Google Scholar 

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Correspondence to M. Kim.

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Kim, M., Lee, E.J., Shin, H.M. et al. The effect of PPARγ agonist on SGLT2 and glucagon expressions in alpha cells under hyperglycemia. J Endocrinol Invest 40, 1069–1076 (2017). https://doi.org/10.1007/s40618-017-0659-1

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  • DOI: https://doi.org/10.1007/s40618-017-0659-1

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