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Liraglutide increases islet Ca2+ oscillation frequency and insulin secretion by activating hyperpolarization-activated cyclic nucleotide-gated channels.
Zaborska, Karolina E; Jordan, Kelli L; Thorson, Ariel S; Dadi, Prasanna K; Schaub, Charles M; Nakhe, Arya Y; Dickerson, Matthew T; Lynch, Joshua C; Weiss, Adam J; Dobson, Jordyn R; Jacobson, David A.
Afiliación
  • Zaborska KE; Department of Molecular Physiology and Biophysics, Vanderbilt University, Nashville, Tennessee.
  • Jordan KL; Department of Molecular Physiology and Biophysics, Vanderbilt University, Nashville, Tennessee.
  • Thorson AS; Department of Molecular Physiology and Biophysics, Vanderbilt University, Nashville, Tennessee.
  • Dadi PK; Department of Molecular Physiology and Biophysics, Vanderbilt University, Nashville, Tennessee.
  • Schaub CM; Department of Molecular Physiology and Biophysics, Vanderbilt University, Nashville, Tennessee.
  • Nakhe AY; Department of Molecular Physiology and Biophysics, Vanderbilt University, Nashville, Tennessee.
  • Dickerson MT; Department of Molecular Physiology and Biophysics, Vanderbilt University, Nashville, Tennessee.
  • Lynch JC; Department of Molecular Physiology and Biophysics, Vanderbilt University, Nashville, Tennessee.
  • Weiss AJ; Department of Molecular Physiology and Biophysics, Vanderbilt University, Nashville, Tennessee.
  • Dobson JR; Department of Molecular Physiology and Biophysics, Vanderbilt University, Nashville, Tennessee.
  • Jacobson DA; Department of Molecular Physiology and Biophysics, Vanderbilt University, Nashville, Tennessee.
Diabetes Obes Metab ; 24(9): 1741-1752, 2022 09.
Article en En | MEDLINE | ID: mdl-35546791
ABSTRACT

AIM:

To determine whether hyperpolarization-activated cyclic nucleotide-gated (HCN) channels impact glucagon-like peptide-1 (GLP-1) receptor (GLP-1R) modulation of islet Ca2+ handling and insulin secretion.

METHODS:

The impact of liraglutide (GLP-1 analogue) on islet Ca2+ handling, HCN currents and insulin secretion was monitored with fluorescence microscopy, electrophysiology and enzyme immunoassays, respectively. Furthermore, liraglutide-mediated ß-to-δ-cell cross-communication was assessed following selective ablation of either mouse islet δ or ß cells.

RESULTS:

Liraglutide increased ß-cell Ca2+ oscillation frequency in mouse and human islets under stimulatory glucose conditions. This was dependent in part on liraglutide activation of HCN channels, which also enhanced insulin secretion. Similarly, liraglutide activation of HCN channels also increased ß-cell Ca2+ oscillation frequency in islets from rodents exposed to a diabetogenic diet. Interestingly, liraglutide accelerated Ca2+ oscillations in a majority of islet δ cells, which showed synchronized Ca2+ oscillations equivalent to ß cells; therefore, we assessed if either cell type was driving this liraglutide-mediated islet Ca2+ response. Although δ-cell loss did not impact liraglutide-mediated increase in ß-cell Ca2+ oscillation frequency, ß-cell ablation attenuated liraglutide-facilitated acceleration of δ-cell Ca2+ oscillations.

CONCLUSION:

The data presented here show that liraglutide-induced stimulation of islet HCN channels augments Ca2+ oscillation frequency. As insulin secretion oscillates with ß-cell Ca2+ , these findings have important implications for pulsatile insulin secretion that is probably enhanced by liraglutide activation of HCN channels and therapeutics that target GLP-1Rs for treating diabetes. Furthermore, these studies suggest that liraglutide as well as GLP-1-based therapies enhance δ-cell Ca2+ oscillation frequency and somatostatin secretion kinetics in a ß-cell-dependent manner.
Asunto(s)

Texto completo: 1 Colección: 01-internacional Banco de datos: MEDLINE Asunto principal: Islotes Pancreáticos / Liraglutida Límite: Animals / Humans Idioma: En Revista: Diabetes Obes Metab Asunto de la revista: ENDOCRINOLOGIA / METABOLISMO Año: 2022 Tipo del documento: Article

Texto completo: 1 Colección: 01-internacional Banco de datos: MEDLINE Asunto principal: Islotes Pancreáticos / Liraglutida Límite: Animals / Humans Idioma: En Revista: Diabetes Obes Metab Asunto de la revista: ENDOCRINOLOGIA / METABOLISMO Año: 2022 Tipo del documento: Article