scholarly journals Regulation of intercellular adhesion molecule-1 gene expression involves multiple mRNA stabilization mechanisms: effects of interferon- gamma and phorbol myristate acetate

Blood ◽  
1994 ◽  
Vol 84 (8) ◽  
pp. 2632-2639 ◽  
Author(s):  
M Ohh ◽  
CA Smith ◽  
C Carpenito ◽  
F Takei

Abstract Although the intercellular adhesion molecule-1 (ICAM-1) is constitutively expressed at a low level on a subpopulation of hematopoietic cells, on vascular endothelium, on fibroblasts, and on certain epithelial cells, it is dramatically increased at sites of inflammation. Interferon-gamma (IFN-gamma) and phorbol myristate acetate (PMA) are known to increase the expression of ICAM-1 on many cell types. Because both human and murine ICAM-1 mRNAs contain putative destabilizing AUUUA sequences in their 3′ untranslated regions (UTRs), we examined the role of mRNA stability in the regulation of ICAM-1 gene expression. The treatment of the murine monocytic cell line P388D1, which constitutively expresses ICAM-1 mRNA at a low level, with IFN- gamma or PMA rapidly enhanced the level of ICAM-1 mRNA and dramatically prolonged its half-life. To determine whether the putative destabilizing sequences are responsible for this effect of IFN-gamma and PMA, fibroblast L cells were transfected with either the full- length ICAM-1 cDNA or a truncated form (ICAM-1 delta 3) lacking the putative destabilizing AUUUA sequences. Although ICAM-1 delta 3 mRNA was more stable than the full-length ICAM-1 mRNA, IFN-gamma treatment induced the accumulation of both mRNA species and prolongation of their half-lives. The transplantation of the ICAM-1 delta 3′ UTR into a stable ICAM-2 mRNA rendered it unstable, and it was unresponsive to IFN- gamma. Therefore, the treatment with IFN-gamma stabilizes the otherwise labile ICAM-1 mRNA, but the IFN-gamma-responsive sequence may at least in part reside within the protein coding region. PMA also upregulated ICAM-1 gene expression by mRNA stabilization. However, unlike IFN- gamma, PMA treatment only increased the level of the full-length, but not of the truncated, ICAM-1 mRNA. This shows that the PMA-responsive element is located within the 3′UTR. Furthermore, the effect of PMA on ICAM-1 delta 3 mRNA was recovered by ligating multiple AUUUA sequences derived from a heterologous gene fragment. The stability of this chimeric mRNA and the full-length ICAM-1 mRNA was markedly increased by PMA treatment, indicating that the AUUUA multimers in the 3′UTR are important in the PMA-induced upregulation of ICAM-1 mRNA.

Blood ◽  
1994 ◽  
Vol 84 (8) ◽  
pp. 2632-2639 ◽  
Author(s):  
M Ohh ◽  
CA Smith ◽  
C Carpenito ◽  
F Takei

Although the intercellular adhesion molecule-1 (ICAM-1) is constitutively expressed at a low level on a subpopulation of hematopoietic cells, on vascular endothelium, on fibroblasts, and on certain epithelial cells, it is dramatically increased at sites of inflammation. Interferon-gamma (IFN-gamma) and phorbol myristate acetate (PMA) are known to increase the expression of ICAM-1 on many cell types. Because both human and murine ICAM-1 mRNAs contain putative destabilizing AUUUA sequences in their 3′ untranslated regions (UTRs), we examined the role of mRNA stability in the regulation of ICAM-1 gene expression. The treatment of the murine monocytic cell line P388D1, which constitutively expresses ICAM-1 mRNA at a low level, with IFN- gamma or PMA rapidly enhanced the level of ICAM-1 mRNA and dramatically prolonged its half-life. To determine whether the putative destabilizing sequences are responsible for this effect of IFN-gamma and PMA, fibroblast L cells were transfected with either the full- length ICAM-1 cDNA or a truncated form (ICAM-1 delta 3) lacking the putative destabilizing AUUUA sequences. Although ICAM-1 delta 3 mRNA was more stable than the full-length ICAM-1 mRNA, IFN-gamma treatment induced the accumulation of both mRNA species and prolongation of their half-lives. The transplantation of the ICAM-1 delta 3′ UTR into a stable ICAM-2 mRNA rendered it unstable, and it was unresponsive to IFN- gamma. Therefore, the treatment with IFN-gamma stabilizes the otherwise labile ICAM-1 mRNA, but the IFN-gamma-responsive sequence may at least in part reside within the protein coding region. PMA also upregulated ICAM-1 gene expression by mRNA stabilization. However, unlike IFN- gamma, PMA treatment only increased the level of the full-length, but not of the truncated, ICAM-1 mRNA. This shows that the PMA-responsive element is located within the 3′UTR. Furthermore, the effect of PMA on ICAM-1 delta 3 mRNA was recovered by ligating multiple AUUUA sequences derived from a heterologous gene fragment. The stability of this chimeric mRNA and the full-length ICAM-1 mRNA was markedly increased by PMA treatment, indicating that the AUUUA multimers in the 3′UTR are important in the PMA-induced upregulation of ICAM-1 mRNA.


1992 ◽  
Vol 263 (1) ◽  
pp. L79-L87 ◽  
Author(s):  
D. C. Look ◽  
S. R. Rapp ◽  
B. T. Keller ◽  
M. J. Holtzman

To evaluate the factors controlling migration of leukocytes into pulmonary airway epithelium, we determined the biochemical mechanisms responsible for the regulation of intercellular adhesion molecule-1 (ICAM-1) expression on cultured monolayers of human tracheal epithelial cells (HTECs) or SV40 virus-transformed human bronchial epithelial cells (BEAS-2B). Validation experiments with human umbilical vein endothelial cells (HUVECs) demonstrated little detectable ICAM-1 expression on unstimulated cells or on cells incubated with interferon-gamma (IFN-gamma), but HUVEC monolayers responded to interleukin-1 beta (IL-1 beta) or tumor necrosis factor-alpha (TNF-alpha) with significant increases in ICAM-1 and ICAM-1-dependent adherence of polymorphonuclear leukocytes (PMNs). HTEC monolayers also exhibited no significant basal ICAM-1 expression but, in contrast to HUVEC monolayers, had marked increases in ICAM-1 expression and ICAM-1-dependent PMN adherence only after incubation with IFN-gamma (and not after IL-1 beta or TNF-alpha) treatment. BEAS-2B cells also exhibited relatively selective IFN-gamma stimulation of ICAM-1 expression and ICAM-1-dependent PMN adherence but (like late passage HTEC) showed significant basal ICAM-1 expression. Differences in IFN-gamma effect on ICAM-1 levels between HUVEC and HTEC monolayers were not due to differences in number or responsiveness of IFN-gamma receptors, because both cell types exhibited a similar number of receptors and other IFN-gamma-dependent responses of HUVECs remained active. In all analyses, ICAM-1 mRNA levels correlated closely with detection of ICAM-1 on the cell surface.(ABSTRACT TRUNCATED AT 250 WORDS)


2013 ◽  
Vol 5 (3) ◽  
pp. 193
Author(s):  
Made Ryan Kharmayani ◽  
Haris Lutfi ◽  
Danu Soesilowati

Latar Belakang : Statin, inhibitor 3-hidroxy-3-methylglutaryl coenzyme A (HMG-CoA) reductase merupakan agen yang paling efektif dalam menurunkan lipid dan mempunyai efek pleiotrofik yaitu anti inflamatori dan immunomodulatori. Statin juga memodifikasi interaksi interseluler dan kemotaksis seluler pada sistem imun serta berpotensi mempengaruhi limfosit T dengan cara menghambat iinteraksi antara adhesi molekul seluler leukocyte function-associated antigen-1 (LFA-1) dan intercellular adhesion molecule-1 (ICAM-1), juga menurunkan interferon gamma (IFN -ɣ) yang berperan dalam ekspresi class II major histocompatibilty complex (MHC II) pada antigen precenting cells (APC) dan merupakan proses penting dalam aktivasi sel T. Penurunan ekspresi MHC II berakibat pada inhibisi aktivasi CD 4 limfosit, sehingga mengakibatkan penurunan diferensiasi T helper-1 (Th1) dan pelepasan sitokin proinflamasi juga menurun.Tujuan : Membuktikan efek simvastatin dosis bertingkat peroral pada mencit yang diberi LPS intraperitoneal terhadap penurunan kadar proliferasi limfosit.Metode : Penelitian eksperimental laboratorik dengan desain randomized post test only controlled group pada 20 ekor mencit Balb/c yang disuntik lipopolisakarida 10 mg/KgBB intraperitoneal dan simvastatin dosis 0,03 mg, 0,06 mg dan 0,12 mg peroral. Mencit dibagi menjadi 4 kelompok secara random, yaitu K1 sebagai control,  K2 yang mendapat simvastatin 0,03 mg, K3 yang mendapat simvastatin 0,06 mg dan K4 yang mendapat simvastatin 0,12 mg. Pemeriksaan limfosit diambil dari kultur limpa setelah 72 jam pemberian simvastatin. Uji statistik yang digunakan adalah parametrik ANOVA dan dilanjutkan PosterioriHasil : Kadar rerata limfosit kelompok K1 (1,546 ± 0,106), K2 (0,541 ± 0,046), K3 (0,471 ± 0,013) dan K4 (0,553 ± 0,02). Terdapat penurunan kadar limfosit secara signifikan pada kelompok K2, K3 dan K4 dibanding K1 dengan p <0,05. Tidak terdapat perbedaan bermakna antara kadar limfosit kelompok K2 dengan kelompok K3 dan K4 ( p>0,05) tetapi didapatkan perbedaan bermakna antara kelompok K3 dibandingkan kelompok K4 ( p<0,05).Simpulan : Simvastatin secara signifikan menurunkan kadar proliferasi limfosit pada mencit yang diberi LPS intraperitoneal. Dosis 0,06 mg memiliki efek menekan kadar proliferasi limfosit paling besar.


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