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Expression and Purification of Recombinant Human S100A8 and S100A9 for Characterization of Their Roles as Danger Signals

Trang, Rebecca LU (2015) KBK820 20151
Pure and Applied Biochemistry
Abstract
The direct involvement of S100 calcium-binding proteins A8 (S100A8) and A9 (S100A9) in numerous human diseases have been discovered more than 20 years ago, and they have ever since emerged as a very potent biomarker. Increased levels of S100A8 and S100A9 have been found in inflammation and various cancers. As complexes, they become crucial danger signals and act as endogenous activators of TLR4 (Toll-like receptor 4) and RAGE (Receptor for Advanced Glycation Endoproducts) on sentinel cells. As danger signals, they activate TLR4- and RAGE-dependent signaling cascades, especially the NF-κB (Nuclear Factor kappa-light-chain-enhancer of activated B cells) signalling pathway.

S100A8 and S100A9 have become the focus of many current researches... (More)
The direct involvement of S100 calcium-binding proteins A8 (S100A8) and A9 (S100A9) in numerous human diseases have been discovered more than 20 years ago, and they have ever since emerged as a very potent biomarker. Increased levels of S100A8 and S100A9 have been found in inflammation and various cancers. As complexes, they become crucial danger signals and act as endogenous activators of TLR4 (Toll-like receptor 4) and RAGE (Receptor for Advanced Glycation Endoproducts) on sentinel cells. As danger signals, they activate TLR4- and RAGE-dependent signaling cascades, especially the NF-κB (Nuclear Factor kappa-light-chain-enhancer of activated B cells) signalling pathway.

S100A8 and S100A9 have become the focus of many current researches since they seem to play a central role as danger signals, however the initial events during binding of the proteins to their receptors remain questionable. The aim of this project was to produce recombinant human S100A8 (rhS100A8) and recombinant human S100A8/S100A9 (rhS100A8/S100A9) to characterize their role as ligands of TLR4-MD2 and RAGE in vitro with surface plasmon resonance (SPR) and as activators of the NF-κB cell-signalling pathway in cell-based in vitro system with NF-κB Luciferase reporter assay.

Within the scope of producing rhS00A8, the protein was expressed in its wild- type (wt) form and compared to S100A8 fused to a His6-tag (His6-rhS100A8). The study observed a much lower stability of wt-rhS100A8, with degradation when subject to potential oxidation. Characterization of His6-S100A8 and wt- rhS100A8/S100A9 confirmed: i) in vitro binding activities of His6-S100A8 to TLR4-MD2 and RAGE with SPR studies; ii) cell-based in vitro binding activities of wt-rhS100A8/S100A9 to TLR4 with NF-κB Luciferase reporter assay and iii) lower binding activities of heterocomplex compared to homocomplex in both previously mentioned systems. (Less)
Popular Abstract
S100A8 and S100A9 are two proteins that have become the focus of many current researches since they seem to play a central role as danger signals in many human diseases, activating various cell signalling pathways via receptors. The initial events during binding of the proteins to their receptors, however, have yet to be clarified. It is therefore of interest to produce S100A8 and S100A9 in order to characterize their interactions with especially TLR4 (Toll-Like Receptor 4) and RAGE (Receptor for Advanced Glycation Endoproducts). This study proposed a second approach to produce human S100A8 and confirmed binding activities of the proteins using in vitro characterization with Surface Plasmon Resonance and with NF-κB Luciferase Reporter... (More)
S100A8 and S100A9 are two proteins that have become the focus of many current researches since they seem to play a central role as danger signals in many human diseases, activating various cell signalling pathways via receptors. The initial events during binding of the proteins to their receptors, however, have yet to be clarified. It is therefore of interest to produce S100A8 and S100A9 in order to characterize their interactions with especially TLR4 (Toll-Like Receptor 4) and RAGE (Receptor for Advanced Glycation Endoproducts). This study proposed a second approach to produce human S100A8 and confirmed binding activities of the proteins using in vitro characterization with Surface Plasmon Resonance and with NF-κB Luciferase Reporter Assay. (Less)
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author
Trang, Rebecca LU
supervisor
organization
course
KBK820 20151
year
type
H2 - Master's Degree (Two Years)
subject
keywords
S100A9, DAMP, RAGE, TLR4, applied biochemistry, tillämpad biokemi, S100A8
language
English
id
7511487
date added to LUP
2015-09-07 09:43:20
date last changed
2015-09-07 09:43:20
@misc{7511487,
  abstract     = {The direct involvement of S100 calcium-binding proteins A8 (S100A8) and A9 (S100A9) in numerous human diseases have been discovered more than 20 years ago, and they have ever since emerged as a very potent biomarker. Increased levels of S100A8 and S100A9 have been found in inflammation and various cancers. As complexes, they become crucial danger signals and act as endogenous activators of TLR4 (Toll-like receptor 4) and RAGE (Receptor for Advanced Glycation Endoproducts) on sentinel cells. As danger signals, they activate TLR4- and RAGE-dependent signaling cascades, especially the NF-κB (Nuclear Factor kappa-light-chain-enhancer of activated B cells) signalling pathway.

S100A8 and S100A9 have become the focus of many current researches since they seem to play a central role as danger signals, however the initial events during binding of the proteins to their receptors remain questionable. The aim of this project was to produce recombinant human S100A8 (rhS100A8) and recombinant human S100A8/S100A9 (rhS100A8/S100A9) to characterize their role as ligands of TLR4-MD2 and RAGE in vitro with surface plasmon resonance (SPR) and as activators of the NF-κB cell-signalling pathway in cell-based in vitro system with NF-κB Luciferase reporter assay.

Within the scope of producing rhS00A8, the protein was expressed in its wild- type (wt) form and compared to S100A8 fused to a His6-tag (His6-rhS100A8). The study observed a much lower stability of wt-rhS100A8, with degradation when subject to potential oxidation. Characterization of His6-S100A8 and wt- rhS100A8/S100A9 confirmed: i) in vitro binding activities of His6-S100A8 to TLR4-MD2 and RAGE with SPR studies; ii) cell-based in vitro binding activities of wt-rhS100A8/S100A9 to TLR4 with NF-κB Luciferase reporter assay and iii) lower binding activities of heterocomplex compared to homocomplex in both previously mentioned systems.},
  author       = {Trang, Rebecca},
  keyword      = {S100A9,DAMP,RAGE,TLR4,applied biochemistry,tillämpad biokemi,S100A8},
  language     = {eng},
  note         = {Student Paper},
  title        = {Expression and Purification of Recombinant Human S100A8 and S100A9 for Characterization of Their Roles as Danger Signals},
  year         = {2015},
}