Intestinal alkaline phosphatase: novel functions and protective effects

Abstract

Important protective roles of intestinal alkaline phosphatase (IAP)--including regulation of intestinal surface pH, absorption of lipids, detoxification of free nucleotides and bacterial lipopolysaccharide, attenuation of intestinal inflammation, and possible modulation of the gut microbiota--have been reviewed recently. IAP is modulated by numerous nutritional factors. The present review highlights new findings on the properties of IAP and extends the list of its protective functions. Critical assessment of data suggests that some IAP properties are a direct result of dephosphorylation of proinflammatory moieties, while others (e.g., gut barrier protection and microbiota shaping) may be secondary to IAP-mediated downregulation of inflammation. IAP and tissue-nonspecific alkaline phosphatase isoforms characterize the small intestine and the colon, respectively. Gastrointestinal administration of exogenous IAP ameliorates gut inflammation and favors gut tissue regeneration, whereas enteral and systemic IAP administration attenuates systemic inflammation only. Finally, the IAP gene family has a strong evolutionary link to food-driven changes in gastrointestinal tract anatomy and microbiota composition. Therefore, stimulation of IAP activity by dietary intervention is a goal for preserving gut homeostasis and health by minimizing low-grade inflammation.

Intestinal alkaline phosphatase promotes gut bacterial growth by reducing the concentration of luminal nucleotide triphosphates

“…In the present study we provide evidence that the brush-border enzyme IAP promotes the growth of commensal bacteria. IAP exerts a number of beneficial effects on the gut, including the maintenance of local gut immunity (8), enhancing barrier function, reducing excessive inflammation, and inhibiting metabolic endotoxemia (4,12,14,21,26). The present study delineates another key beneficial impact of the IAP enzyme, promoting the growth of the commensal flora.…”

Gut epithelial inducible heat-shock proteins and their modulation by diet and the microbiota

“…6,7 Briefly, the functions of intestinal alkaline phosphatase include detoxification of LPS, control of gut microbiota composition, and anti-inflammation. One main conclusion of these reviews is that various nutrients and food components can stimulate the expression and activity of intestinal alkaline phosphatase, thus partially explaining their anti-inflammatory properties.…”

The chemical redox modulated switch-on fluorescence of carbon dots for probing alkaline phosphatase and its application in an immunoassay

“…[7][8][9][10] The abnormal level of serum ALP is related to various diseases including dynamic bone disease, diabetes, breast and prostate cancer, and liver dysfunction. [11][12][13] In addition, ALP is a widely used labeling enzyme for use in immunoassays, 14 DNA hybridization analysis and protein detection.…”