Platycodin D-induced apoptosis through nuclear factor-kappaB activation in immortalized keratinocytes.
Platycodi Radix is the root of Platycodon grandiflorum and it is widely used in the traditional Oriental medicine as an expectorant for pulmonary diseases and a remedy for respiratory disorders. Platycodin D is the major constituent of triterpene saponins in the root. This study investigates apoptosis by platycodin D in immortalized human keratinocytes (HaCaT). Platycodin D-induced apoptosis in HaCaT cells was confirmed by DNA fragmentation, caspase-3 activation, and caspase-8 activation. Platycodin D could activate inhibitor of nuclear factor-kappaB kinase (IKK)-beta in the nuclear factor-kappaB (NF-kappaB) activation of upstream level, but not IKK-alpha. Pretreated-N-tosyl-l-phenylalanine chloromethyl ketone (TPCK), a potent NF-kappaB inhibitor, could suppress the induction of apoptosis and activation of NF-kappaB of HaCaT cells by platycodin D. We also demonstrated that platycodin D-mediated apoptosis of HaCaT cells upregulates Fas receptor and Fas ligand (FasL) expression, but did not exhibit p53 activation. HaCaT cells were also transfected with pFLF1, which preserves the promoter region of Fas receptor gene containing NF-kappaB binding site. On incubation with platycodin D, the NF-kappaB activity related to Fas receptor increased in a dose-dependent manner. Among the major transcription elements on Fas receptor and FasL promoter, NF-kappaB activation was shown to have an essential role in the expression of the death receptor such as FasL. These results suggest that platycodin D has the ability to induce apoptosis in HaCaT cells through the upregulation of Fas receptor and FasL expression via to NF-kappaB activation in the transcriptional level. These results demonstrate that the NF-kappaB activation plays a crucial role in the induction of apoptosis in human HaCaT cells on treatment with platycodin D.
Ahn
Kwang Seok
KS
Natural Products Research Institute, College of Pharmacy, Seoul National University, 28 Yeonkun-Dong, Seoul 110-460, Korea.
Hahn
Bum-Soo
BS
Kwack
Kyubum
K
Lee
Eun Bang
EB
Kim
Yeong Shik
YS
D000818:Animals; D017209:Apoptosis / Q000187:drug effects*; D053148:Caspase 3; D053181:Caspase 8; D020169:Caspases / Q000378:metabolism; D002460:Cell Line; D045744:Cell Line, Tumor; D002470:Cell Survival / Q000187:drug effects; D053938:DNA Fragmentation; D053222:Fas Ligand Protein; D005786:Gene Expression Regulation / Q000187:drug effects; D006801:Humans; D051550:I-kappa B Kinase; D020287:In Situ Nick-End Labeling; D015603:Keratinocytes / Q000187:drug effects*; D008562:Membrane Glycoproteins / Q000235:genetics / Q000378:metabolism; D051379:Mice; D016328:NF-kappa B / Q000378:metabolism*; D012333:RNA, Messenger / Q000378:metabolism; D012503:Saponins / Q000494:pharmacology*; D014315:Triterpenes / Q000494:pharmacology*; D048069:Tumor Necrosis Factors / Q000235:genetics / Q000378:metabolism; D019014:fas Receptor / Q000235:genetics / Q000378:metabolism
C505661:FASLG protein, human; D053222:Fas Ligand Protein; C505658:Fasl protein, mouse; D008562:Membrane Glycoproteins; D016328:NF-kappa B; D012333:RNA, Messenger; D012503:Saponins; D014315:Triterpenes; D048069:Tumor Necrosis Factors; D019014:fas Receptor; C108953:platycodin D; D051550:I-kappa B Kinase; C496560:IKBKB protein, human; C505407:CASP3 protein, human; C505530:CASP8 protein, human; C505409:Casp3 protein, mouse; C505526:Casp8 protein, mouse; D053148:Caspase 3; D053181:Caspase 8; D020169:Caspases