Identification of regulatory mechanisms of intestinal folate transport in condition of folate deficiency

The proton-coupled folate transporter (PCFT-SLC46A1) and the syndrome of systemic and cerebral folate deficiency of infancy: Hereditary folate malabsorption

“…Caco2 cells can be grown as a tight monolayer of differentiated cells, with high electrical resistance, on a membrane that separates two aqueous compartments. In this way PCFT-mediated bidirectional fluxes and net transport of folates from the apical to basal compartments, as occurs in the intestine, can be measured under a variety of conditions (Thakur et al, 2015; Urquhart et al, 2010). These types of studies can also be performed with the MDCK canine kidney cell monolayers (Urquhart et al, 2010).…”

“…A 13.5-fold decrease in the blood folate level over this interval was accompanied by a comparable increase in PCFT mRNA expression in the proximal small intestine; however, function was not assessed in intestinal tissue (Liu et al, 2005; Qiu et al, 2007). More recently (Thakur et al, 2015), a folate deficient diet for 3–5 months in Wistar rats, in the absence of a sulfonamide, produced a lesser decrease in serum folate but a 5-fold increase in PCFT mRNA expression accompanied by a ~50% increase in the folic acid uptake V max into intestinal brush-border membrane vesicles. While folate deficiency in Caco2 cells in vitro produced an 11-fold increase in PCFT mRNA, this was accompanied by a much smaller (~65%) increase in the apical to basal flux across a Caco2 monolayer (Thakur et al, 2015).…”

“…More recently (Thakur et al, 2015), a folate deficient diet for 3–5 months in Wistar rats, in the absence of a sulfonamide, produced a lesser decrease in serum folate but a 5-fold increase in PCFT mRNA expression accompanied by a ~50% increase in the folic acid uptake V max into intestinal brush-border membrane vesicles. While folate deficiency in Caco2 cells in vitro produced an 11-fold increase in PCFT mRNA, this was accompanied by a much smaller (~65%) increase in the apical to basal flux across a Caco2 monolayer (Thakur et al, 2015). At the molecular level, changes in PCFT expression were not associated with alterations in the methylation of the promoter region as might be expected to occur with a methyl donor deficiency as a consequence of folate deficiency (Thakur et al, 2015).…”

“…While folate deficiency in Caco2 cells in vitro produced an 11-fold increase in PCFT mRNA, this was accompanied by a much smaller (~65%) increase in the apical to basal flux across a Caco2 monolayer (Thakur et al, 2015). At the molecular level, changes in PCFT expression were not associated with alterations in the methylation of the promoter region as might be expected to occur with a methyl donor deficiency as a consequence of folate deficiency (Thakur et al, 2015). In an earlier study, much higher PCFT mRNA expression in villus versus crypt intestinal cells was reported but there was only a modest increase in PCFT protein and folic acid transport at low pH which accompanied confluency and differentiation of Caco2 cells (Subramanian et al, 2008b).…”

Epigenetic modifications at DMRs of placental genes are subjected to variations in normal gestation, pathological conditions and folate supplementation

“…The folate levels within placental villi samples were estimated using Lactobacillus casei assay, as previously explained72. Briefly, 10% homogenate of villous tissue was prepared in folate extraction buffer containing 50 mM ascorbic acid.…”