Category BI L05 Proinflammatory cytokine TNF-α regulates sphingolipid

signaling in Human

Abstract This experiment investigates the signaling pathways of endothelial cells,

which are substituted by HUVEC (Human Umbilical Vein Endothelial Cells)

in this project, which can cause arterial disease and inflammation. The

experiment will use the fact that S1P (sphingosine-1-phosphate) has been

shown to transactivate the TNF α (Tumor Necrosis Factor-Alpha)

receptor and activate VCAM (Vascular Cell Adhesion Molecule), to find the

role of S1P signaling in the induction of proinflammatory cytokine in

response to TNF α activation in HUVEC and possible applications in

arterial disease and cancer development cells. The experiment was

performed in two steps; first, to show TNFα induces S1P receptors

in the cell signaling process, and second, to prove the S1P2 receptor

activates VCAM in the cell signaling process. Step one was performed by

letting HUVEC treated with TNFα (no treatment, control) undertake

real time PCR. The result for the first part was that S1P2 added with TNF

α yielded over twice as many cells as the control. In step two, four

different scenarios were presented. They are: the control, TNF α,

JTE013 (the antagonist of S1P receptors), and the TNF α and JTE013

treatment. The real time PCR yielded interesting results. The VCAM

expression for the TNF α treatment increased over 150 fold more

than the control. The JTE013 treatment was almost the same as the

control. The TNF α and JTE013 treatment increased about five fold

over the control. The results showed that JTE013 could significantly inhibit

TNF-α mediation of VCAM expression, suggesting that an increase

of S1P2 contributes to the introduction of inflammatory cytokine VCAM in

response to TNF-α. Finally, the data strongly indicates that the S1P2

pathway is an important part of the TNF-α signaling pathway and it is

at least involved in the increase of the VCAM gene. The fact that TNF

α activation of S1P2 expression contribute to VCAM signaling could

be critical for the progression of arterial disease. Thus, this study provides

new compelling evidence on the mechanism by which TNF-α gives

rise to inflammation in Human arterial tissue, opening new perspectives for

its pharmacological treatment.

Bibliography 1) Estrada, Rosendo. "Up-regulating Sphingosine 1-Phosphate Receptor-2

Signaling Impairs Chemotactic, Wound-healing, and Morphogenetic

Responses in Senescent Endothelial Cells — JBC." The Journal of

Biological Chemistry. 21 Aug. 2008. Web. 07 Nov. 2010.

http://www.jbc.org/content/283/44/30363.abstract>. 2) Wiess, Tania L.

"Serial Subculture and Relative Transport of Human Endothelial Cells in

Serum-free, Defined Conditions."

Http://www.springerlink.com/content/5224v16n41201868/. 13 Mar. 1990.

Web. 10 Nov. 2010.

3) Lee, Menq-Jer. "Vascular Endothelial Cell Adherens Junction." Cell 99

(1999): 301-12. Print.
First Previous Next Last