Prevention of Mucosal Atrophy

Role of Glutamine and Caspases in Apoptosis in Intestinal Epithelial Cells

Harry T. Papaconstantinou, Dai H. Chung, Weiping Zhang, Naseem Ansari, Mark Hellmich, Courtney Townsend, Tien C. Ko

Research output: Contribution to journalArticle

52 Citations (Scopus)

Abstract

Glutamine starvation induces apoptosis in enterocytes; therefore glutamine is important in the maintenance of gut mucosal homeostasis. However, the molecular mechanisms are unknown. The caspase family of proteases constitutes the molecular machinery that drives apoptosis. Caspases are selectively activated in a stimulus-specific and tissue-specific fashion. The aims of this study were to (1) identify specific caspases activated by glutamine starvation and (2) determine whether a general caspase inhibitor blocks glutamine starvation-induced apoptosis in intestinal epithelial cells. Rat intestinal epithelial (RIE-1) cells were deprived of glutamine. Specific caspase activation was measured using fluorogenic substrate assay. Apoptosis was quantified by DNA fragmentation and Hoechst nuclear staining. Glutamine starvation of RIE-1 cells resulted in the time-dependent activation of caspases 3 (10 hours) and 2 (18 hours), and the induction of DNA fragmentation (12 hours). Caspases 1 and 8 remained inactive. ZVAD-fluoromethyl ketone, a general caspase inhibitor, completely blocked glutamine starvation-induced caspase activation, DNA fragmentation, and nuclear condensation. These results indicate that glutamine starvation selectively activates specific caspases, which leads to the induction of apoptosis in RIE-1 cells. Furthermore, inhibition of caspase activity blocked the induction of apoptosis, suggesting that caspases are potential molecular targets to attenuate apoptotic responses in the gut.

Original languageEnglish (US)
Pages (from-to)416-423
Number of pages8
JournalJournal of Gastrointestinal Surgery
Volume4
Issue number4
StatePublished - Jul 2000

Fingerprint

Caspases
Glutamine
Atrophy
Starvation
Epithelial Cells
Apoptosis
DNA Fragmentation
Caspase Inhibitors
Caspase 10
Caspase 1
Caspase 8
Enterocytes
Ketones
Fluorescent Dyes
Caspase 3
Homeostasis
Peptide Hydrolases
Maintenance
Staining and Labeling

Keywords

  • Apoptosis
  • Caspases
  • Glutamine
  • Intestinal mucosa

ASJC Scopus subject areas

  • Surgery

Cite this

Prevention of Mucosal Atrophy : Role of Glutamine and Caspases in Apoptosis in Intestinal Epithelial Cells. / Papaconstantinou, Harry T.; Chung, Dai H.; Zhang, Weiping; Ansari, Naseem; Hellmich, Mark; Townsend, Courtney; Ko, Tien C.

In: Journal of Gastrointestinal Surgery, Vol. 4, No. 4, 07.2000, p. 416-423.

Research output: Contribution to journalArticle

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