Endoplasmic reticulum-resident chaperones modulate the inflammatory and angiogenic responses of endothelial cells.

Abstract

BACKGROUND:

Wound healing depends on a well-balanced regulation of inflammation and angiogenesis. In chronic wounds the healing process is disturbed and inflammation persists. Regulation of wound closure is controlled by transmembrane and extracellular proteins, the folding and maturation of which occur in the endoplasmic reticulum (ER) by ER-resident chaperone machinery.

OBJECTIVES:

To study the role of the ER-resident chaperones BiP/Grp78, its cochaperone Mdg1/ERdJ4, and Grp94 in chronic, nonhealing wounds.

METHODS:

Immunohistochemical staining of these chaperones in individual human biopsies and investigation of the possible role of BiP and Mdg1 in endothelial cells, focusing on their inflammatory response and angiogenic potential.

RESULTS:

In all chronic wounds investigated, the levels of these ER-resident chaperones were elevated in endothelial cells and leucocytes. The proangiogenic role of BiP has been shown in tumour growth studies before and was confirmed in this study. Proangiogenic activity of the cochaperone Mdg1 has been postulated before but could not be confirmed in this study. The chemokine tumour necrosis factor (TNF)-α was shown to trigger the presentation of proinflammatory adhesion molecules and the release of proinflammatory cytokines. Here we show that TNF-α does not affect endogenous chaperone levels, but that the ER-resident chaperones BiP and Mdg1 modulate the cellular TNF-α-induced proinflammatory response.

CONCLUSIONS:

According to the presented data we assume that in chronic wounds upregulated levels of ER-resident chaperones might contribute to persistent inflammation in chronic wounds. Therapies to downregulate chaperone levels might provide a tool that switches the imbalanced chronic wound microenvironment from inflammation to healing.

• Authors: R Tsaryk, N M Bartholomä, N Simiantonaki, L Anspach, K Peters, C Heilmann, C J Kirkpatrick, F Pröls
• Journal: The British journal of dermatology (Br J Dermatol) Vol. 173 Issue 2 Pg. 416-27 (Aug 2015) ISSN: 1365-2133 [Electronic] England
• PMID: 25832777 (Publication Type: Journal Article, Research Support, Non-U.S. Gov't)
• Copyright: © 2015 British Association of Dermatologists.

Chemical References

• DNAJB9 protein, human
• Endoplasmic Reticulum Chaperone BiP
• HSP40 Heat-Shock Proteins
• HSPA5 protein, human
• Heat-Shock Proteins
• Membrane Glycoproteins
• Membrane Proteins
• Molecular Chaperones
• Tumor Necrosis Factor-alpha
• endoplasmin

Topics

• Cells, Cultured
• Chronic Disease
• Down-Regulation (physiology)
• Endoplasmic Reticulum (physiology)
• Endoplasmic Reticulum Chaperone BiP
• Endothelial Cells (physiology)
• HSP40 Heat-Shock Proteins (metabolism, physiology)
• Heat-Shock Proteins (metabolism)
• Humans
• Inflammation (physiopathology)
• Membrane Glycoproteins (metabolism, physiology)
• Membrane Proteins (metabolism, physiology)
• Molecular Chaperones (metabolism, physiology)
• Neovascularization, Physiologic (physiology)
• Tumor Necrosis Factor-alpha (physiology)
• Wound Healing (physiology)