Epithelial properties of human colonic carcinoma cell line Caco-2: effect of secretagogues

Abstract

Human colonic carcinoma Caco-2 cells grown in vitro form epithelial layers of highly polarized cells. Unlike colonic adsorptive cells they possess a mucosal membrane with very limited ionic conductance, even after exposure to aldosterone. When grown on filters, Caco-2 cells were sensitive to various secretagogues; these included 10(-5) M dibutyryl adenosine 3',5'-cyclic monophosphate (DBcAMP) and 10(-10) M vasoactive intestinal peptide, both of which, added serosally, enhanced the short-circuit current. The same applied to mucosal forskolin. Caco-2 cell sensitivity to serosal epinephrine was lower. Ion substitutions and 22Na-36Cl flux measurements indicated the possibility of secretagogue-dependent chloride secretion. Measurements on cells grown on Petri dishes and exposed to 1 mM DBcAMP for 1 h enabled detection of more profound modifications. Sustained 20-mV cell depolarization and a large reduction in the relative electrical resistance of the mucosal membrane were concomitant with a sizable decrease in 36Cl accumulation. These results suggest that Caco-2 cells, which to some extent resemble colonic crypt cells, possess the cAMP-dependent mucosal chloride conductance characteristic of secretory cells.

Parathyroid hormone (PTH) rapidly enhances CFTR-mediated HCO3−secretion in intestinal epithelium-like Caco-2 monolayer: a novel ion regulatory action of PTH

“…Impedance spectroscopy was performed by using 1255B frequency response analyzer and 1287A electrochemical interface (Solartron, Farnborough, UK). Sine-wave alternating current (35 A/cm 2 root mean square amplitude, 0.5 Hz-10 kHz) was applied across Caco-2 monolayer at different time points, i.e., before adding 10 nmol/l PTH 1-34 or 10 mol/l forskolin, and at 1,5,10,15,20,25,30,35 (Fig. 1A) was automatically analyzed by Zplot/Zview.…”

“…In this study, the colorectal adenocarcinoma-derived Caco-2 cell monolayer was used because it possessed the apical brush border, polarization, and anion transport functions resembling the native epithelium from the small intestine (25,34). Moreover, the monolayer was devoid of the underlying connective tissue and smooth muscle layers, both of which might hinder measurements of transepithelial ion current and plasma membrane impedance (61).…”

IFN-γ and TNF-α decrease serotonin transporter function and expression in Caco2 cells

“…For these studies we have used an immortalized human intestinal epithelial cell line (Caco2 cells), which natively express SERT (24). Originally derived from a human carcinoma of the colon, these cells form a polarized monolayer when grown in vitro (12,13,17). They possess a mucosal membrane that models intestinal transport and metabolic parameters of the human gut (see Refs.…”

Differential Cl-and HCO3-mediated anion secretion by different colonic cell types in response to tetromethylpyrazine

“…The observed difference between T84 and Caco-2 cells in their I SC responses to different concentrations of TMP suggested that colonic Cl -and HCO 3 -mediated secretions might be differentially elicited by the same agent depending on the concentrations used, probably due to differential expression of receptors, cotranspoters, exchangers and ion channels [10][11][12][13] leading to differential responses to TMP. This notion is supported by the observation that TMP at different concentrations could elicit different I SC responses from freshly isolated rat colon mucosa with distinct current characteristics.…”

“…T84 cell line is a well-characterized colonic epithelial model that maintains a secretory phenotype similar to crypt base cells, and has been widely used to examine the regulation of intestinal Cl -secretion since CFTR and Na + -K + -Cl -cotransporter (NKCC) are highly expressed in this cell line [1,10,11] . The properties of human colonic Caco-2 cells are mostly close to those of mature absorptive villus/surface cells but they possess a certain CFTR characteristic of secretory cells [1,12,13] . However, few studies have been conducted to compare the secretory properties of these cell lines.…”