Suppression of NF-κB Activation by Entamoeba histolytica in Intestinal Epithelial Cells Is Mediated by Heat Shock Protein 27

Abstract

The intestinal protozoan parasite Entamoeba histolytica affects 50 million people worldwide, causing 100,000 deaths per year (1). Intestinal amebiasis is characterized by colitis and severe dysentery. Despite our knowledge of the role of several pathogen and host factors in causing colonic inflammation, the cell-specific response to amebic infection is poorly understood. Moreover, the majority of research done to unravel the mechanism of amebic colitis has been focused on proinflammatory responses (2, 3) by epithelial cells and a role of NF-B (4) and chemokines such as IL-8 3 (5) as triggering events for inflammation. However, it is noteworthy that only 10% of E. histolytica-infected individuals show symptoms of intestinal inflammation (6), and none of the studies addressed the question of why only a minority of infected individuals develops amebic colitis.

Effects of Tritrichomonas muris on the Mouse Intestine: A Proteomic Analysis

“…Moreover, the expression of heat shock proteins in the epithelium is regulated by cytokines and immune cells such as lymphocytes [16]. Our result is consistent with the result that prolonged stimulation with soluble amoebic proteins reduced the level of HSP27 in a human colonic epithelial cell line [14]. Although it is not clear how the down-regulation of HSP27 is involved in T. muris infection, it is implicit that T. muris injures and induces inflammation at least in the epithelium of the host intestine.…”

Celastrol, a novel triterpene, potentiates TNF-induced apoptosis and suppresses invasion of tumor cells by inhibiting NF-κB–regulated gene products and TAK1-mediated NF-κB activation

“…19 Several heat shock proteins, including hsp 27, hsp 70, and hsp 90, have been found to inhibit NF-B activation. [61][62][63] Besides, many compounds that activate the heat shock response also inhibit NF-B. 64 Thus, it is possible that heat shock protein is involved in suppression of TNF-induced NF-B activation by celastrol.…”

Amoebiasis in the Tropics: Epidemiology and Pathogenesis

“…The disease in the colon is the most common with acute diarrhoea and dysentery accounting for 90% of the clinical amoebiasis cases (Espinosa-Cantellano and Martínez-Palomo, 2000) and only 1% involve the liver (Figure 4). (Kammanadiminti and Chadee, 2006). Furthermore, products secreted by non-pathogenic E. histolytica strains normally disrupt and suppress NFκB signaling and as a result diminish pro-inflammatory responses normally detrimental to the parasite (Artis, 2008).…”