Physiologically relevant increase in temperature causes an increase in intestinal epithelial tight junction...

Area of Science:

• Physiology
• Cell Biology
• Gastroenterology

Background:

• Intestinal epithelial tight junction (TJ) barrier integrity is crucial for preventing endotoxemia and bacterial translocation.
• The impact of physiologically relevant temperature increases on the intestinal TJ barrier and the role of heat-shock proteins (HSPs) remain uncharacterized.

Purpose of the Study:

• To investigate the effects of modest temperature increases (37-41°C) on intestinal epithelial TJ barrier function.
• To examine the protective role of HSPs in maintaining intestinal TJ barrier integrity during heat stress.

Main Methods:

• Utilized filter-grown Caco-2 intestinal epithelial cells as an in vitro model.
• Assessed TJ permeability and HSP expression following controlled heat exposure.
• Investigated the effects of HSP inhibition on TJ barrier function and occludin localization.

Main Results:

• Modest temperature increases (37-41°C) significantly increased Caco-2 TJ permeability in a time- and temperature-dependent manner.
• Heat exposure rapidly increased HSP expression; HSP inhibition exacerbated heat-induced TJ permeability.
• HSP inhibition prevented compensatory occludin upregulation and disrupted occludin localization during heat stress.

Conclusions:

• Physiologically relevant temperature increases disrupt intestinal epithelial TJ barrier function.
• HSPs play a critical protective role against heat-induced intestinal TJ barrier disruption.
• HSP-mediated occludin upregulation is a key mechanism for maintaining intestinal barrier integrity under heat stress.