Folate binding by the brush border membrane proteins of small intestinal epithelial cells

Biochemistry ◽  
1972 ◽  
Vol 11 (9) ◽  
pp. 1696-1703 ◽  
Author(s):  
Garth I. Leslie ◽  
Peter B. Rowe
Keyword(s):  
Membrane Proteins ◽  
Epithelial Cells ◽  
Brush Border ◽  
Brush Border Membrane ◽  
Intestinal Epithelial Cells ◽  
Intestinal Epithelial ◽  
Small Intestinal

scholarly journals Peroxynitrite Uniquely Regulates Brush Border Membrane Anion/HCO3- Exchange in Rat Small Intestinal Epithelial Cells

2011 ◽  
Vol 140 (5) ◽  
pp. S-661-S-662
Author(s):  
Andrew K. Roorda ◽  
Palanikumar Manoharan ◽  
Ramesh Kekuda ◽  
Steven D. Coon ◽  
Uma Sundaram
Keyword(s):  
Epithelial Cells ◽  
Brush Border ◽  
Brush Border Membrane ◽  
Intestinal Epithelial Cells ◽  
Intestinal Epithelial ◽  
Small Intestinal

scholarly journals Unique Regulation of Enterocyte Brush Border Membrane Na-Glutamine and Na-Alanine Co-Transport by Peroxynitrite during Chronic Intestinal Inflammation

2019 ◽  
Vol 20 (6) ◽  
pp. 1504 ◽  
Author(s):  
Subha Arthur ◽  
Palanikumar Manoharan ◽  
Shanmuga Sundaram ◽  
M Rahman ◽  
Balasubramanian Palaniappan ◽  
...  
Keyword(s):  
Epithelial Cells ◽  
Brush Border ◽  
Brush Border Membrane ◽  
Intestinal Inflammation ◽  
Intestinal Epithelial Cells ◽  
Rabbit Model ◽  
Intestinal Epithelial ◽  
Mechanism Of Inhibition ◽  
Chronic Intestinal Inflammation

Na-amino acid co-transporters (NaAAcT) are uniquely affected in rabbit intestinal villus cell brush border membrane (BBM) during chronic intestinal inflammation. Specifically, Na-alanine co-transport (ASCT1) is inhibited secondary to a reduction in the affinity of the co-transporter for alanine, whereas Na-glutamine co-transport (B0AT1) is inhibited secondary to a reduction in BBM co-transporter numbers. During chronic intestinal inflammation, there is abundant production of the potent oxidant peroxynitrite (OONO). However, whether OONO mediates the unique alteration in NaAAcT in intestinal epithelial cells during chronic intestinal inflammation is unknown. In this study, ASCT1 and B0AT1 were inhibited by OONO in vitro. The mechanism of inhibition of ASCT1 by OONO was secondary to a reduction in the affinity of the co-transporter for alanine, and secondary to a reduction in the number of co-transporters for B0AT1, which were further confirmed by Western blot analyses. In conclusion, peroxynitrite inhibited both BBM ASCT1 and B0AT1 in intestinal epithelial cells but by different mechanisms. These alterations in the villus cells are similar to those seen in the rabbit model of chronic enteritis. Therefore, this study indicates that peroxynitrite may mediate the inhibition of ASCT1 and B0AT1 during inflammation, when OONO levels are known to be elevated in the mucosa.

scholarly journals Inducible Nitric Oxide Regulates Brush Border Membrane Na-Glucose Co-transport, but Not Na:H Exchange via p38 MAP Kinase in Intestinal Epithelial Cells

Cells ◽  
2018 ◽  
Vol 7 (8) ◽  
pp. 111 ◽  
Author(s):  
Palanikumar Manoharan ◽  
Shanmuga Sundaram ◽  
Soudamani Singh ◽  
Uma Sundaram
Keyword(s):  
Nitric Oxide ◽  
Epithelial Cells ◽  
Brush Border ◽  
Brush Border Membrane ◽  
Intestinal Inflammation ◽  
Intestinal Epithelial Cells ◽  
Intestinal Epithelial ◽  
Mechanism Of Inhibition ◽  
Chronic Intestinal Inflammation ◽  
Inducible Nitric Oxide

During chronic intestinal inflammation in rabbit intestinal villus cells brush border membrane (BBM) Na-glucose co-transport (SGLT1), but not Na/H exchange (NHE3) is inhibited. The mechanism of inhibition is secondary to a decrease in the number of BBM co-transporters. In the chronic enteritis mucosa, inducible nitric oxide (iNO) and superoxide production are known to be increased and together they produce abundant peroxynitrite (OONO), a potent oxidant. However, whether OONO mediates the SGLT1 and NHE3 changes in intestinal epithelial cells during chronic intestinal inflammation is unknown. Thus, we determined the effect of OONO on SGLT1 and NHE3 in small intestinal epithelial cell (IEC-18) monolayers grown on trans well plates. In cells treated with 100 μM SIN-1 (OONO donor) for 24 h, SGLT1 was inhibited while NHE3 activity was unaltered. SIN-1 treated cells produced 40 times more OONO fluorescence compared to control cells. Uric acid (1mM) a natural scavenger of OONO prevented the OONO mediated SGLT1 inhibition. Na+/K+-ATPase which maintains the favorable trans-cellular Na gradient for Na-dependent absorptive processes was decreased by OONO. Kinetics studies demonstrated that the mechanism of inhibition of SGLT1 by OONO was secondary to reduction in the number of co-transporters (Vmax) without an alteration in the affinity. Western blot analysis showed a significant decrease in SGLT1 protein expression. Further, p38 mitogen-activated protein (MAP) kinase pathway appeared to mediate the OONO inhibition of SGLT1. Finally, at the level of the co-transporter, 3-Nitrotyrosine formation appears to be the mechanism of inhibition of SGLT1. In conclusion, peroxynitrite inhibited BBM SGLT1, but not NHE3 in intestinal epithelial cells. These changes and the mechanism of SGLT1 inhibition by OONO in IEC-18 cells is identical to that seen in villus cells during chronic enteritis. Thus, these data indicate that peroxynitrite, known to be elevated in the mucosa, may mediate the inhibition of villus cell BBM SGLT1 in vivo in the chronically inflamed intestine.

T1870 Brush Border Membrane Na:H Exchange Regulates Na-Glucose Co-Transport in Intestinal Epithelial Cells

2008 ◽  
Vol 134 (4) ◽  
pp. A-580
Author(s):  
Ramesh Kekuda ◽  
Steven Coon ◽  
Prosenjit Saha ◽  
Jamilur R. Talukder ◽  
Uma Sundaram
Keyword(s):  
Epithelial Cells ◽  
Brush Border ◽  
Brush Border Membrane ◽  
Intestinal Epithelial Cells ◽  
Intestinal Epithelial
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