Abstract
Total parenteral nutrition (TPN), a commonly used treatment for patients who cannot receive enteral nutrition, is associated with significant septic complications due in part to a loss of epithelial barrier function (EBF). While the underlying mechanisms of TPN-related epithelial changes are poorly understood, a mouse model of TPN-dependence has helped identify several contributing factors. Enteral deprivation leads to a shift in intestinal microbiota to predominantly Gram-negative Proteobacteria. This is associated with an increase in expression of proinflammatory cytokines within the mucosa, including interferon-γ and tumor necrosis factor-α. A concomitant loss of epithelial growth factors leads to a decrease in epithelial cell proliferation and increased apoptosis. The resulting loss of epithelial tight junction proteins contributes to EBF dysfunction. These mechanisms identify potential strategies of protecting against TPN-related complications, such as modification of luminal bacteria, blockade of proinflammatory cytokines, or growth factor replacement.
Highlights
PHYSIOLOGIC AND IMMUNOLOGIC CHANGES WITH Total parenteral nutrition (TPN) IN A MOUSE MODEL While the etiology of the increased rate of infectious complications with TPN is not fully established, it is known that many of the organisms responsible for these infections predominantly originate from enteric microbiota, suggesting a TPN-associated loss of intestinal epithelial barrier function (EBF) (Feng et al, 2012)
Exogenous interleukin 10 (IL-10) administration ameliorated TPN-induced loss of zonula occludens 1 (ZO-1), ZO-2, claudin-2, and occludin (Sun et al, 2008). Production of these proteins is related to p-Akt signaling, as our work has shown that down-regulation of E-Cadherin expression in TPNdependent mice is tightly related to a decrease in p-Akt activity (Feng et al, 2009)
DIRECTIONS While TPN serves a life-sustaining purpose in patients who must remain deprived of enteral nutrition for a prolonged period, it is not without risk
Summary
Due to mechanical, functional, or postoperative deficits, some patients are unable to use their intestinal tract for nutritious gain For these patients who are enterally deprived, total parenteral nutrition (TPN) is an alternative method of nutrition which provides nutrients and calories intravenously (Abunnaja et al, 2013). Casaer et al expanded upon these findings, demonstrating a lack of benefit with early administration of TPN in critically-ill patients, but poorer outcomes compared to later and more judicious initiation of TPN (Casaer et al, 2011) Such complications have led to cautious administration of TPN and utilization of enteral feeding whenever possible (Braunschweig et al, 2001)
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
