Gp96 deficiency affects TLR4 functionality and impairs ERK and p38 phosphorylation
Por:
Cosin-Roger, J, Spalinger, M, Ruiz, P, Stanzel, C, Terhalle, A, Wolfram, L, Melhem, H, Atrott, K, Lang, S, Frey-Wagner, I, Fried, M, Scharl, M, Hausmann, M and Rogler, G
Publicada:
15 feb 2018
Resumen:
Gp96 is an endoplasmic reticulum chaperone for multiple protein substrates. Its lack in intestinal macrophages of Crohn's disease (CD) patients is correlated with loss of tolerance against the host gut flora. Gp96 has been stablished to be an essential chaperone for Toll-like receptors (TLRs). We studied the impact of gp96-knockdown on TLR-function in macrophages. TLR2 and TLR4 expression was only decreased but not abolished when gp96 was knocked-down in cell lines, whereas in a monocyte/macrophage specific knock-out mouse model (LysMCre) TLR4 was abolished, while TLR2 was still present. Lipopolysaccharide (LPS)-induced NF-kappa B activation was still observed in the absence of gp96, and gp96-deficient macrophages were able to up-regulate surface TLR4 upon LPS treatment, suggesting that there is another chaperone involved in the folding of TLR4 upon stress responses. Moreover, LPS-dependent pro-inflammatory cytokines were still expressed, although to a lesser extent in the absence of gp96, which reinforces the fact that gp96 is involved in regulating signaling cascades downstream of TLR4 are impaired upon loss of gp96. In addition, we have also found a reduced phosphorylation of ERK and p38 kinases and an impaired response upon CSF1R activation in gp96 deficient macrophages. Our findings indicate that the loss of gp96 not only impairs TLR4 signaling, but is also associated with a diminished phosphorylation of ERK and mitogen-activated stress kinases resulting in an impaired signalling through several receptors, including CSF1R.
Filiaciones:
:
Univ Zurich, Univ Hosp Zurich, Dept Gastroenterol & Hepatol, Zurich, Switzerland
Spalinger, M:
Univ Zurich, Univ Hosp Zurich, Dept Gastroenterol & Hepatol, Zurich, Switzerland
Ruiz, P:
Univ Zurich, Univ Hosp Zurich, Dept Gastroenterol & Hepatol, Zurich, Switzerland
Stanzel, C:
Univ Zurich, Univ Hosp Zurich, Dept Gastroenterol & Hepatol, Zurich, Switzerland
Terhalle, A:
Univ Zurich, Univ Hosp Zurich, Dept Gastroenterol & Hepatol, Zurich, Switzerland
Wolfram, L:
Univ Zurich, Univ Hosp Zurich, Dept Gastroenterol & Hepatol, Zurich, Switzerland
Melhem, H:
Univ Zurich, Univ Hosp Zurich, Dept Gastroenterol & Hepatol, Zurich, Switzerland
Atrott, K:
Univ Zurich, Univ Hosp Zurich, Dept Gastroenterol & Hepatol, Zurich, Switzerland
Lang, S:
Univ Zurich, Univ Hosp Zurich, Dept Gastroenterol & Hepatol, Zurich, Switzerland
Frey-Wagner, I:
Univ Zurich, Univ Hosp Zurich, Dept Gastroenterol & Hepatol, Zurich, Switzerland
Fried, M:
Univ Zurich, Univ Hosp Zurich, Dept Gastroenterol & Hepatol, Zurich, Switzerland
Scharl, M:
Univ Zurich, Univ Hosp Zurich, Dept Gastroenterol & Hepatol, Zurich, Switzerland
Hausmann, M:
Univ Zurich, Univ Hosp Zurich, Dept Gastroenterol & Hepatol, Zurich, Switzerland
Rogler, G:
Univ Zurich, Univ Hosp Zurich, Dept Gastroenterol & Hepatol, Zurich, Switzerland
Green Accepted, gold, Green Submitted, Green Published
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