Expression of Endoplasmic Reticulum-Mediated Stress Proteins in FK506-Treated T-Lymphocytes.
BACKGROUND
FK506-induced apoptotic endoplasmic reticulum (ER)-mediated stress protein expression was investigated in Jurkat human T-lymphocytes.


METHODS
The effect of FK506 on apoptosis and cell viability were examined. FK506-induced apoptosis was confirmed by nuclear fragmentation after DAPI staining. Expression of apoptotic ER-mediated stress proteins was examined by means of Western blotting of Grp78/BiP, Grp94, double-stranded RNA-dependent protein kinase (PKR)-like ER kinase (PERK), phosphor-PERK, CHOP/GADD153, and Bak. A flow cytometry analysis was performed after DAF-DA or DCF-DA staining. FK506-induced apoptosis was dose-dependent (10 nmol/L) and time-dependent (72 hours).


RESULTS
Grp78/BiP and Grp94 expressions were increased 36 hours after FK506 treatment. Increased phospho-PERK expression was observed 6 hours after FK506 treatment and peak activation of phospho-PERK was observed at 36 hours. CHOP/GADD153 expression was increased 48 hours after FK506 treatment. Expression of iNOS after FK506 treatment began to increase at 12 hours, peaked at 24 hours, and decreased after 36 hours.


CONCLUSIONS
From these results, we confirmed that FK506 induces apoptosis and acts dose- and time-dependently to decrease the viability of Jurkat cells through activation of apoptosis signaling and expression of apoptotic ER-mediated stress proteins.
Department of Surgery, Chonnam National University Medical School, Gwangju, Korea.
H K
HK
Lee
Department of Medicine, Chonnam National University Medical School, Gwangju, Korea.
M W
MW
Chung
Department of Surgery, Chonnam National University Medical School, Gwangju, Korea.
Y W
YW
Chung
Department of Medicine, Chonnam National University Medical School, Gwangju, Korea.
S K
SK
Choi
Department of Surgery, Chonnam National University Medical School, Gwangju, Korea.
S J N
SJ
Choi
Department of Surgery, Chonnam National University Medical School, Gwangju, Korea. Electronic address: sycpvts@chonnam.ac.kr.
S Y
SY
Chung
D017209:Apoptosis / Q000187:drug effects; D002352:Carrier Proteins / Q000378:metabolism; D002470:Cell Survival / Q000187:drug effects; D004721:Endoplasmic Reticulum / Q000378:metabolism; D000091342:Endoplasmic Reticulum Chaperone BiP; D059865:Endoplasmic Reticulum Stress / Q000187:drug effects*; D018840:HSP70 Heat-Shock Proteins / Q000378:metabolism; D006360:Heat-Shock Proteins / Q000378:metabolism; D006801:Humans; D007166:Immunosuppressive Agents / Q000494:pharmacology*; D019169:Jurkat Cells / Q000502:physiology; D008565:Membrane Proteins / Q000378:metabolism; D015398:Signal Transduction / Q000187:drug effects; D016559:Tacrolimus / Q000494:pharmacology*; D051742:Transcription Factor CHOP / Q000378:metabolism; D019892:eIF-2 Kinase / Q000378:metabolism
D002352:Carrier Proteins; D000091342:Endoplasmic Reticulum Chaperone BiP; D018840:HSP70 Heat-Shock Proteins; D006360:Heat-Shock Proteins; D007166:Immunosuppressive Agents; D008565:Membrane Proteins; D016559:Tacrolimus; D051742:Transcription Factor CHOP; D019892:eIF-2 Kinase; C497249:DDIT3 protein, human; C000717247:HSPA5 protein, human; C429767:TP53INP1 protein, human; C018551:glucose-regulated proteins