Lipopolysaccharides Indirectly Stimulate Apoptosis and Global Induction of Apoptotic Genes in Fibroblasts

Mani Alikhani, Zoubin Alikhani, Hongbing He, Rongkun Liu, Barbara I. Popek, Dana T. Graves

Research output: Contribution to journalArticle

Abstract

Following Gram-negative bacterial infection there is a reduction in matrix-producing cells. The goal of the present study was to examine the apoptotic effects of lipopolysaccharide (LPS) on fibroblastic cells and to investigate the role that the host response plays in this reaction. This was accomplished in vivo by subcutaneous inoculation of LPS in wild type and TNFRI-/-R2-/- mice. The direct effects of LPS on fibroblast apoptosis was studied in vitro with normal diploid human fibroblasts. The results indicate that LPS in vivo induces apoptosis of fibroblasts. By RNA profiling we demonstrated that LPS stimulates global expression of apoptotic genes and down-regulates anti-apoptotic genes. Fluorometric studies demonstrated that LPS in vivo significantly increased caspase-8 and caspase-3 activity and by use of specific inhibitors, the activation of caspase-3 was shown to be initiated by caspase-8 with no contribution from caspase-9. In vitro studies demonstrated that LPS did not induce apoptosis of fibroblasts, whereas tumor necrosis factor (TNF) did. In addition, the pattern of apoptotic gene expression induced by TNF in vitro was nearly identical to that induced by LPS in vivo, as measured by RNase protection assay. Moreover, pre-treatment of cells with TNF greatly enhanced apoptosis induced by a second stimulation with TNF 24 h later, suggesting that the global induction of proapoptotic genes was functionally significant. Thus, LPS acts to modulate the expression of a large number of genes that favor apoptosis of fibroblastic cells that is dependent upon activation of caspase-8 and is largely mediated by TNF.

Original languageEnglish (US)
Pages (from-to)52901-52908
Number of pages8
JournalJournal of Biological Chemistry
Volume278
Issue number52
DOIs
StatePublished - Dec 26 2003

Fingerprint

Fibroblasts
Lipopolysaccharides
Genes
Apoptosis
Tumor Necrosis Factor-alpha
Caspase 8
Caspase 3
Gram-Negative Bacterial Infections
Chemical activation
Gene Expression
Caspase 9
Ribonucleases
Diploidy
Gene expression
Assays
Down-Regulation
Cells
RNA

ASJC Scopus subject areas

  • Biochemistry

Cite this

Lipopolysaccharides Indirectly Stimulate Apoptosis and Global Induction of Apoptotic Genes in Fibroblasts. / Alikhani, Mani; Alikhani, Zoubin; He, Hongbing; Liu, Rongkun; Popek, Barbara I.; Graves, Dana T.

In: Journal of Biological Chemistry, Vol. 278, No. 52, 26.12.2003, p. 52901-52908.

Research output: Contribution to journalArticle

Alikhani, Mani ; Alikhani, Zoubin ; He, Hongbing ; Liu, Rongkun ; Popek, Barbara I. ; Graves, Dana T. / Lipopolysaccharides Indirectly Stimulate Apoptosis and Global Induction of Apoptotic Genes in Fibroblasts. In: Journal of Biological Chemistry. 2003 ; Vol. 278, No. 52. pp. 52901-52908.
@article{3d54117a13574674b4d7ffaf94205f48,
title = "Lipopolysaccharides Indirectly Stimulate Apoptosis and Global Induction of Apoptotic Genes in Fibroblasts",
abstract = "Following Gram-negative bacterial infection there is a reduction in matrix-producing cells. The goal of the present study was to examine the apoptotic effects of lipopolysaccharide (LPS) on fibroblastic cells and to investigate the role that the host response plays in this reaction. This was accomplished in vivo by subcutaneous inoculation of LPS in wild type and TNFRI-/-R2-/- mice. The direct effects of LPS on fibroblast apoptosis was studied in vitro with normal diploid human fibroblasts. The results indicate that LPS in vivo induces apoptosis of fibroblasts. By RNA profiling we demonstrated that LPS stimulates global expression of apoptotic genes and down-regulates anti-apoptotic genes. Fluorometric studies demonstrated that LPS in vivo significantly increased caspase-8 and caspase-3 activity and by use of specific inhibitors, the activation of caspase-3 was shown to be initiated by caspase-8 with no contribution from caspase-9. In vitro studies demonstrated that LPS did not induce apoptosis of fibroblasts, whereas tumor necrosis factor (TNF) did. In addition, the pattern of apoptotic gene expression induced by TNF in vitro was nearly identical to that induced by LPS in vivo, as measured by RNase protection assay. Moreover, pre-treatment of cells with TNF greatly enhanced apoptosis induced by a second stimulation with TNF 24 h later, suggesting that the global induction of proapoptotic genes was functionally significant. Thus, LPS acts to modulate the expression of a large number of genes that favor apoptosis of fibroblastic cells that is dependent upon activation of caspase-8 and is largely mediated by TNF.",
author = "Mani Alikhani and Zoubin Alikhani and Hongbing He and Rongkun Liu and Popek, {Barbara I.} and Graves, {Dana T.}",
year = "2003",
month = "12",
day = "26",
doi = "10.1074/jbc.M307638200",
language = "English (US)",
volume = "278",
pages = "52901--52908",
journal = "Journal of Biological Chemistry",
issn = "0021-9258",
publisher = "American Society for Biochemistry and Molecular Biology Inc.",
number = "52",

}

TY - JOUR

T1 - Lipopolysaccharides Indirectly Stimulate Apoptosis and Global Induction of Apoptotic Genes in Fibroblasts

AU - Alikhani, Mani

AU - Alikhani, Zoubin

AU - He, Hongbing

AU - Liu, Rongkun

AU - Popek, Barbara I.

AU - Graves, Dana T.

PY - 2003/12/26

Y1 - 2003/12/26

N2 - Following Gram-negative bacterial infection there is a reduction in matrix-producing cells. The goal of the present study was to examine the apoptotic effects of lipopolysaccharide (LPS) on fibroblastic cells and to investigate the role that the host response plays in this reaction. This was accomplished in vivo by subcutaneous inoculation of LPS in wild type and TNFRI-/-R2-/- mice. The direct effects of LPS on fibroblast apoptosis was studied in vitro with normal diploid human fibroblasts. The results indicate that LPS in vivo induces apoptosis of fibroblasts. By RNA profiling we demonstrated that LPS stimulates global expression of apoptotic genes and down-regulates anti-apoptotic genes. Fluorometric studies demonstrated that LPS in vivo significantly increased caspase-8 and caspase-3 activity and by use of specific inhibitors, the activation of caspase-3 was shown to be initiated by caspase-8 with no contribution from caspase-9. In vitro studies demonstrated that LPS did not induce apoptosis of fibroblasts, whereas tumor necrosis factor (TNF) did. In addition, the pattern of apoptotic gene expression induced by TNF in vitro was nearly identical to that induced by LPS in vivo, as measured by RNase protection assay. Moreover, pre-treatment of cells with TNF greatly enhanced apoptosis induced by a second stimulation with TNF 24 h later, suggesting that the global induction of proapoptotic genes was functionally significant. Thus, LPS acts to modulate the expression of a large number of genes that favor apoptosis of fibroblastic cells that is dependent upon activation of caspase-8 and is largely mediated by TNF.

AB - Following Gram-negative bacterial infection there is a reduction in matrix-producing cells. The goal of the present study was to examine the apoptotic effects of lipopolysaccharide (LPS) on fibroblastic cells and to investigate the role that the host response plays in this reaction. This was accomplished in vivo by subcutaneous inoculation of LPS in wild type and TNFRI-/-R2-/- mice. The direct effects of LPS on fibroblast apoptosis was studied in vitro with normal diploid human fibroblasts. The results indicate that LPS in vivo induces apoptosis of fibroblasts. By RNA profiling we demonstrated that LPS stimulates global expression of apoptotic genes and down-regulates anti-apoptotic genes. Fluorometric studies demonstrated that LPS in vivo significantly increased caspase-8 and caspase-3 activity and by use of specific inhibitors, the activation of caspase-3 was shown to be initiated by caspase-8 with no contribution from caspase-9. In vitro studies demonstrated that LPS did not induce apoptosis of fibroblasts, whereas tumor necrosis factor (TNF) did. In addition, the pattern of apoptotic gene expression induced by TNF in vitro was nearly identical to that induced by LPS in vivo, as measured by RNase protection assay. Moreover, pre-treatment of cells with TNF greatly enhanced apoptosis induced by a second stimulation with TNF 24 h later, suggesting that the global induction of proapoptotic genes was functionally significant. Thus, LPS acts to modulate the expression of a large number of genes that favor apoptosis of fibroblastic cells that is dependent upon activation of caspase-8 and is largely mediated by TNF.

UR - http://www.scopus.com/inward/record.url?scp=0346732274&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=0346732274&partnerID=8YFLogxK

U2 - 10.1074/jbc.M307638200

DO - 10.1074/jbc.M307638200

M3 - Article

VL - 278

SP - 52901

EP - 52908

JO - Journal of Biological Chemistry

JF - Journal of Biological Chemistry

SN - 0021-9258

IS - 52

ER -