Taurine increases glucose sensitivity of UCP2-overexpressing β-cells by ameliorating mitochondrial metabolism

Jin Han, Jae Hoon Bae, So Yeon Kim, Hyun Young Lee, Byeong Churl Jang, In Kyu Lee, Chi Heum Cho, Jeong Geun Lim, Seong Il Suh, Taeg Kyu Kwon, Jong Wook Park, Shin Young Ryu, Won Kyung Ho, Yung E. Earm, Dae Kyu Song

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37 Scopus citations

Abstract

A low-taurine diet during fetal or early postnatal life causes abnormal pancreatic β-cell development. Tissue and plasma taurine concentrations can also be low in diabetic patients. We examined the effect of taurine on impaired glucose responses in diabetic rat β-cells adenovirally overexpressing uncoupling protein (UCP)2, which is upregulated in obesity-related type 2 diabetes. We found that taurine pretreatment restored the ATP-to-ADP (ATP/ADP) ratio and glucose-stimulated insulin secretion in UCP2-infected islets. ATP-sensitive K+ channel sensitivity to dihydroxyacetone, another insulin secretagogue, was similar in both UCP2-infected and control β-cells. In freshly isolated mitochondria from UCP2-overexpressing insulin-secreting (INS)-1 β-cells, methyl pyruvate-mediated mitochondrial Ca2+ increase was significantly ameliorated by taurine. A mitochondrial Ca2+ uniporter blocker, ruthenium red, inhibited the action of taurine. This study suggests that taurine enhances the glucose sensitivity of UCP2-overexpressing β-cells, probably by increasing mitochondrial Ca2+ influx through the Ca2+ uniporter, thereby enhancing mitochondrial metabolic function and increasing the ATP/ADP ratio.

Original languageEnglish
JournalAmerican Journal of Physiology - Endocrinology and Metabolism
Volume287
Issue number5 50-5
DOIs
StatePublished - 1 Nov 2004

Keywords

  • ATP-sensitive K channel
  • ATP-to-ADP ratio
  • Insulin
  • Mitochondrial Ca
  • Pancreatic islets
  • Uncoupling protein 2

Cite this

Han, J., Bae, J. H., Kim, S. Y., Lee, H. Y., Jang, B. C., Lee, I. K., Cho, C. H., Lim, J. G., Suh, S. I., Kwon, T. K., Park, J. W., Ryu, S. Y., Ho, W. K., Earm, Y. E., & Song, D. K. (2004). Taurine increases glucose sensitivity of UCP2-overexpressing β-cells by ameliorating mitochondrial metabolism. American Journal of Physiology - Endocrinology and Metabolism, 287(5 50-5). https://doi.org/10.1152/ajpendo.00008.2004