RFC-1 gene expression regulates folate absorption in mouse small intestine

Area of Science:

• Gastroenterology
• Molecular Biology
• Cell Biology

Background:

• Folate absorption in the small intestine is essential for cellular function and is mediated by specific transport mechanisms.
• Understanding the regulation of folate transport is critical for addressing nutritional deficiencies and related health issues.

Purpose of the Study:

• To delineate the pH-dependent and non-pH-dependent components of folate transport in mouse small intestine epithelial cells.
• To investigate the role of RFC-1 gene expression in regulating pH-dependent folate absorption.

Main Methods:

• Isolated luminal epithelial cells from mouse small intestine were used to study folate transport.
• Differential sensitivity to 4,4'-diisothiocyanatostilbene-2,2'-disulfonic acid was employed to distinguish transport components.
• RFC-1 gene expression and protein levels were analyzed during cell maturation.

Main Results:

• Folate transport was characterized by distinct pH-dependent and non-pH-dependent components.
• The pH-dependent component showed higher capacity at acidic pH and was developmentally regulated, increasing in mature cells.
• Increased pH-dependent transport correlated with elevated RFC-1 gene expression and protein levels.

Conclusions:

• pH-dependent folate absorption in the small intestine is primarily regulated by RFC-1 gene expression.
• RFC-1 plays a significant role in the maturation-dependent increase of folate uptake.
• These findings provide insights into the molecular mechanisms of folate homeostasis.