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Cellular & Molecular Biology Letters

Open Access

Thy28 partially prevents apoptosis induction following engagement of membrane immunoglobulin in WEHI-231 B lymphoma cells

  • Hiroko Toyota1,
  • Xiao-Zhou Jiang1,
  • Hideki Asakura1 and
  • Junichiro Mizuguchi1Email author
Cellular & Molecular Biology LettersAn International Journal201117:34

Received: 21 April 2011

Accepted: 26 November 2011

Published: 2 December 2011


Thy28 protein is conserved among plants, bacteria, and mammalian cells. Nuclear Thy28 protein is substantially expressed in testis, liver, and immune cells such as lymphocytes. Lymphocyte apoptosis plays a crucial role in homeostasis and formation of a diverse lymphocyte repertoire. In this study, we examined whether Thy28 affects induction of apoptosis in WEHI-231 B lymphoma cells following engagement of membrane immunoglobulin (mIg). Once they were established, the Thy28-overexpressing WEHI-231 cells showed similar expression levels of IgM and class I major histocompatibility complex (MHC) molecule compared with controls. The Thy28-overexpressing cells were considerably resistant to loss of mitochondrial membrane potential (ΔΨm), caspase-3 activation, and increase in annexin-positive cells upon mIg engagement. These changes were concomitant with an increase in G1 phase associated with upregulation of p27Kip1. The anti-IgM-induced sustained activation of c-Jun N-terminal kinase (JNK), which was associated with late-phase hydrogen peroxide (H2O2) production, was partially reduced in the Thy28-expressing cells relative to controls. Taken together, the data suggest that in WEHI-231 B lymphoma cells, Thy28 regulates mIg-mediated apoptotic events through the JNK-H2O2 activation pathway, concomitant with an accumulation of cells in G1 phase associated with upregulation of p27Kip1 in WEHI-231 B lymphoma cells.

Key words

Thy28B Lymphoma CellsApoptosisMembrane Immunoglobulin