scholarly journals Homocysteine stimulates phosphorylation of NADPH oxidase p47phox and p67phox subunits in monocytes via protein kinase Cβ activation

2006 ◽  
Vol 398 (1) ◽  
pp. 73-82 ◽  
Author(s):  
Yaw L. Siow ◽  
Kathy K. W. Au-Yeung ◽  
Connie W. H. Woo ◽  
Karmin O
Keyword(s):  
Protein Kinase ◽  
Nadph Oxidase ◽  
Superoxide Anion ◽  
Monocytic Cell ◽  
Superoxide Anion Production ◽  
Monocytic Cell Line ◽  
Protein Kinase C Inhibitors ◽  
Human Monocytic Cell Line ◽  
Anion Production ◽  
Human Monocytic Cell

Hyperhomocysteinaemia is an independent risk factor for cardiovascular diseases due to atherosclerosis. The development of atherosclerosis involves reactive oxygen species-induced oxidative stress in vascular cells. Our previous study [Wang and O (2001) Biochem. J. 357, 233–240] demonstrated that Hcy (homocysteine) treatment caused a significant elevation of intracellular superoxide anion, leading to increased expression of chemokine receptor in monocytes. NADPH oxidase is primarily responsible for superoxide anion production in monocytes. In the present study, we investigated the molecular mechanism of Hcy-induced superoxide anion production in monocytes. Hcy treatment (20–100 μM) caused an activation of NADPH oxidase and an increase in the superoxide anion level in monocytes (THP-1, a human monocytic cell line). Transfection of cells with p47phox siRNA (small interfering RNA) abolished Hcy-induced superoxide anion production, indicating the involvement of NADPH oxidase. Hcy treatment resulted in phosphorylation and subsequently membrane translocation of p47phox and p67phox subunits leading to NADPH oxidase activation. Pretreatment of cells with PKC (protein kinase C) inhibitors Ro-32-0432 (bisindolylmaleimide XI hydrochloride) (selective for PKCα, PKCβ and PKCγ) abolished Hcy-induced phosphorylation of p47phox and p67phox subunits in monocytes. Transfection of cells with antisense PKCβ oligonucleotide, but not antisense PKCα oligonucleotide, completely blocked Hcy-induced phosphorylation of p47phox and p67phox subunits as well as superoxide anion production. Pretreatment of cells with LY333531, a PKCβ inhibitor, abolished Hcy-induced superoxide anion production. Taken together, these results indicate that Hcy-stimulated superoxide anion production in monocytes is regulated through PKC-dependent phosphorylation of p47phox and p67phox subunits of NADPH oxidase. Increased superoxide anion production via NADPH oxidase may play an important role in Hcy-induced inflammatory response during atherogenesis.

scholarly journals Screening of compounds toxicity against human Monocytic cell line-THP-1 by flow cytometry

10.1251/bpo92 ◽  
2004 ◽  
Vol 6 (1) ◽  
pp. 220-225 ◽  
Author(s):  
Neora Pick ◽  
Scott Cameron ◽  
Dorit Arad ◽  
Yossef Av-Gay
Keyword(s):  
Flow Cytometry ◽  
Cell Line ◽  
Monocytic Cell ◽  
Monocytic Cell Line ◽  
Human Monocytic Cell Line ◽  
Human Monocytic Cell

scholarly journals Modified Vaccinia Virus Ankara Triggers Chemotaxis of Monocytes and Early Respiratory Immigration of Leukocytes by Induction of CCL2 Expression

2009 ◽  
Vol 83 (6) ◽  
pp. 2540-2552 ◽  
Author(s):  
Michael H. Lehmann ◽  
Wolfgang Kastenmuller ◽  
Judith D. Kandemir ◽  
Florian Brandt ◽  
Yasemin Suezer ◽  
...  
Keyword(s):  
Vaccinia Virus ◽  
Viral Vector ◽  
Monocytic Cell ◽  
Monocytic Cell Line ◽  
Human Monocytic Cell Line ◽  
Modified Vaccinia Virus Ankara ◽  
Ccl2 Expression ◽  
Human Monocytic Cell

ABSTRACT Orthopoxviruses commonly enter into humans and animals via the respiratory tract. Herein, we show that immigration of leukocytes into the lung is triggered via intranasal infection of mice with modified vaccinia virus Ankara (MVA) and not with the vaccinia virus (VACV) Elstree, Wyeth, or Western Reserve (WR) strain. Immigrating cells were identified as monocytes, neutrophils, and CD4+ lymphocytes by flow cytometry and could be detected 24 h and 48 h postinfection. Using an in vitro chemotaxis assay, we confirmed that infection with MVA induces the expression of a soluble chemotactic factor for monocytes, identified as CCL2 (monocyte chemotactic protein-1 [MCP-1]). In contrast to infection with several other VACV strains, MVA induced the expression of CCL2, CCL3, CCL4, and CXCL10 in the human monocytic cell line THP-1 as well as in primary human monocytes. Thus, MVA, and not the VACV Elstree, Wyeth, or WR strain, consistently triggered the expression of a panel of chemokines, including CCL2, in the murine lung, correlating considerably with the immigration of leukocytes. Using CCL2-deficient mice, we demonstrate that CCL2 plays a key role in MVA-triggered respiratory immigration of leukocytes. Moreover, UV irradiation of MVA prevented CCL2 expression in vitro and in vivo as well as respiratory immigration of leukocytes, demonstrating the requirement for an activated molecular viral life cycle. We propose that MVA-triggered chemokine expression causes early immigration of leukocytes to the site of infection, a feature that is important for rapid immunization and its safety and efficiency as a viral vector.

scholarly journals Alkaline Comet Assay using the monocytic cell line THP-1

2019 ◽  
Author(s):  
Ana Neves-Costa ◽  
Dora Pedroso ◽  
Luis F Moita
Keyword(s):  
Comet Assay ◽  
Cell Line ◽  
Adherent Cell ◽  
Monocytic Cell ◽  
Monocytic Cell Line ◽  
Strand Breaks ◽  
Human Monocytic Cell Line ◽  
Human Monocytic Cell ◽  
Dna Strand

Abstract This protocol details the experimental procedure for performing the comet assay, a very sensitive DNA break assay based on single cell gel electrophoresis.The analysis of DNA strand breaks, both single- and double-strand breaks (SSBs and DSBs, respectively), was performed in immune responsive cells. The cell line used was the human monocytic cell line THP-1, an adherent cell type with many known applications in in vitro studies of innate immunity. The comet assay is a robust procedure that allows the accurate and reproducible quantification of DNA damage. Here we describe not only the comet assay step-by-step protocol, but also some important aspects related to troubleshooting.

Sign in / Sign up

Export Citation Format

Share Document