1,3-Dinitrobenzene induces apoptosis in TM4 mouse Sertoli cells: Involvement of the c-Jun N-terminal kinase (JNK) MAPK pathway.
Several studies have shown that 1,3-dinitrobenzene (1,3-DNB) causes injury to Sertoli cells and induces apoptosis in the surrounding germinal cells in male laboratory rats; however, the mechanism by which 1,3-DNB functions is not well understood. In this study, we investigated whether 1,3-DNB induces apoptosis and which pathways are undertaken in TM4 cells. When cells were treated with 1,3-DNB, a dose-dependent reduction in cell viability was observed by tetrazolium dye assay and LDH assay. The reduced cell viability by 1,3-DNB treatment appeared to involve necrosis as well as apoptosis, based on staining with annexin V-FITC and propidium iodide (PI) staining and Western blotting for PARP protein. 1,3-DNB treatment decreased total transcript and protein levels of the apoptosis inhibitory protein Bcl-2, and increased expression levels of the pro-apoptotic protein Bax. In addition, using FACS analysis we detected G2/M phase cell cycle arrest by 1,3-DNB, concurrent with a remarkable increase in p21 expression and decrease in cdc2 expression. Interestingly, we found that the phosphorylation of c-Jun N-terminal kinase (JNK), and extracellular signal-regulated kinase (ERK) was promoted by 1,3-DNB, furthermore, 1,3-DNB-induced cell death was significantly inhibited by the JNK inhibitor, but not by ERK inhibitor or the p38 inhibitor. Together, our results suggest that 1,3-DNB induces apoptotic cell death and G2/M phase cell cycle arrest, at least in part, via JNK signaling in TM4 mouse Sertoli cells.
Lee
Young Sook
YS
Toxicogenomics Team, Korea Institute of Toxicology, Daejeon 305-343, Republic of Korea.
Yoon
Hea-Jin
HJ
Oh
Jung-Hwa
JH
Park
Han-Jin
HJ
Lee
Eun-Hee
EH
Song
Chang-Woo
CW
Yoon
Seokjoo
S
D000818:Animals; D017209:Apoptosis; D002453:Cell Cycle / Q000187:drug effects; D002460:Cell Line; D004136:Dinitrobenzenes / Q000633:toxicity*; D004785:Environmental Pollutants / Q000633:toxicity; D048670:MAP Kinase Kinase 4 / Q000378:metabolism*; D008297:Male; D051379:Mice; D012708:Sertoli Cells / Q000166:cytology* / Q000187:drug effects*
D004136:Dinitrobenzenes; D004785:Environmental Pollutants; C017906:3-dinitrobenzene; D048670:MAP Kinase Kinase 4