Oxidized but not acetylated low-density lipoprotein reduces preproinsulin mRNA expression and secretion of insulin from HIT-T15 cells

Fumitaka Okajima, Mikiko Kurihara, Chihaya Ono, Yasushi Nakajima, Kyoko Tanimura, Hitoshi Sugihara, Atsushi Tatsuguchi, Kiyotaka Nakagawa, Teruo Miyazawa, Shinichi Oikawa

Research output: Contribution to journalArticlepeer-review

15 Citations (Scopus)

Abstract

We examined the effect of oxidized low-density lipoprotein (oxLDL) on the insulin secretion in the culture of HIT-T15 cell line, an islet β-cell line derived from a hamster pancreatic tumor. In order to check the uptake of modified LDL by HIT-T15 cells, we prepared DiI-labeled native LDL (nLDL), acetylated LDL (AcLDL), and oxLDL. After the addition of each LDL into the cultures of HIT-T15 cells, fluorescence microscopic study was done. It was suggested that AcLDL and oxLDL were taken up by HIT-T15 cells, as well as nLDL. mRNA expression of the LDL receptor, CD36, and SR-B1 was detected in HIT-T15 by RT-PCR. The medium insulin level was measured in the culture of HIT-T15 cells with each LDL. oxLDL significantly reduced the insulin secretion stimulated by various concentrations of glucose, the intracellular content of insulin, and the expression of preproinsulin mRNA compared to the control cultures without LDL addition. In contrast, nLDL and AcLDL had no effect on the insulin secretion, the intracellular insulin level, or the expression of preproinsulin mRNA. MTT assay findings (reflecting cell numbers) were not different between cultures with and without LDLs. These results indicated that oxLDL disturbed the insulin metabolism of HIT-T15 cells.

Original languageEnglish
Pages (from-to)173-180
Number of pages8
JournalBiochimica et Biophysica Acta - Molecular and Cell Biology of Lipids
Volume1687
Issue number1-3
DOIs
Publication statusPublished - 2005 Feb 21

Keywords

  • HIT-T15 cell
  • Lipid peroxidation
  • Oxidative stress
  • Oxidized LDL
  • Pancreatic beta cell
  • Scavenger receptor

ASJC Scopus subject areas

  • Molecular Biology
  • Cell Biology

Fingerprint Dive into the research topics of 'Oxidized but not acetylated low-density lipoprotein reduces preproinsulin mRNA expression and secretion of insulin from HIT-T15 cells'. Together they form a unique fingerprint.

Cite this