Aim The present study developed a CYP3A4-expressed Caco-2 monolayer model at which effects of the efflux-metabolism alliance on the transport and uptake of clausenamide（CLA） enantiomers as CYP3A4 substrates were inv...Aim The present study developed a CYP3A4-expressed Caco-2 monolayer model at which effects of the efflux-metabolism alliance on the transport and uptake of clausenamide（CLA） enantiomers as CYP3A4 substrates were investigated. The apparent permeability coefficients （Papp） of （ - ） and （ ＋ ）CLA were higher in the ab- sorptive direction than those in the secretory direction with efflux ratios（ER） of 0. 709 ± 0.411 and 0. 867± 0. 250 （ Х10^-6 -1 cm · s ）, respectively. Their bidirectional transports were significantly reduced by （75.6 ± 87.5）% af- ter treatment with verapamil （ a P-glycoprotein inhibitor） that increased the rate of metabolism by CYP3 A4, whereas the CYP3A4 inhibitor ketoconazole treatment markedly enhanced the basolateral to apical flux of （ - ） and （ ＋ ） CLA with ERs being 2. 934 ± 1. 432 and 1. 877 ± 0. 148 （ Х 10^-6 cm/s） respectively. These changes could be blocked by the duel CYP3A4/P-glycoprotein inhibitor cyclosporine A, consequently, Papp values for CLA enanti- omers in both directions were significantly greater than those obtained by using verapamil or ketoconazole, and their ERs were similar to those following （ - ） or （ ＋ ）-isomer treatment alone. Furthermore, the uptake of （ - ）CLA was more than that of （ ＋ ）CLA in the transfected cells. Incubation with ketoeonazole decreased the intracellular concentrations of the two enantiomers. This effect disappeared in the presence of a CYP3A4 inducer dexametha- sone. These results indicated that CYP3A4 could influence P-gp efflux, transport and uptake of CLA enantiomers as CYP3A4 substrates and that a duel inhibition to CYP3A4/ P-glycoprotein could enhance their absorption and bioavailability, which provides new insight into the efflux-metabolism alliance and will benefit the clinical pharma- cology of （？） CLA as a candidate drug for treatment of Alzheimer＇ s disease.展开更多
AIM： To investigate the possible involvement of 25-hydroxyvitamin D3-1cx-hydroxylase [1α-25（OH）2D3] in butyrate-induced differentiation in human intestinal cell line Caco-2 cells. METHODS： Caco-2 cells were incub...AIM： To investigate the possible involvement of 25-hydroxyvitamin D3-1cx-hydroxylase [1α-25（OH）2D3] in butyrate-induced differentiation in human intestinal cell line Caco-2 cells. METHODS： Caco-2 cells were incubated either with 3 mmol/L butyrate and 1 umol/L 25（OH）2D3 or with 1 umol/L 1α-25（OH）2D3 for various time intervals ranging from 0 to 72 h. Additionally, cells were co-incubated with butyrate and either 25（OH）2D3 or 1α-25（OH）2D3. 1α-25（OH）2D3 mRNA was determined semi-quantitatively using the fluorescent dye PicoGreen. Immunoblotting was used for the detection of 1α-25（OH）2D3 protein. Finally, enzymatic activity was measured by ELISA. RESULTS： Both butyrate and 1α-25（OH）2D3 stimulated differentiation of Caco-2 cells after a 48 h incubation period, while 25（OH）2D3 had no impact on cell differentiation. Synergistic effects on differentiation were observed when cells were co-incubated with butyrate and vitamin D metabolite. Butyrate transiently upregulated 1α-25（OH）2D3 mRNA followed by a timely delayed protein upregulation. Coincidently, enzymatic activity was enhanced significantly. The induction of the enzyme allowed for comparable differentiating effects of both vitamin D metabolites. CONCLUSION： Our experimental data provide a further mechanism for the involvement of the vitamin D signaling pathway in colonic epithelial cell differentiation by butyrate. The enhancement of 1α-25（OH）2D3 followed by antiproliferative effects of the vitamin D prohormone in the Caco-2 cell line suggest that 25（OH）2D3 in combination with butyrate may offer a new therapeutic approach forthe treatment of colon cancer.展开更多
3D （Three-dimensional） Caco-2 spheroids closely recapitulating in vivo physiological organization of intestinal epithelial cells, provide an excellent in vitro model system to study their pathophysiology and their r...3D （Three-dimensional） Caco-2 spheroids closely recapitulating in vivo physiological organization of intestinal epithelial cells, provide an excellent in vitro model system to study their pathophysiology and their response to stressful stimuli. The objective of this technical note is to provide optimized in vitro experimental protocols for culturing 3D Caco-2 spheroids and for analyzing their cell growth features. An optimized 3D Caco-2 spheroid culturing technique based on a new configuration of the culture medium is provided A methodological approach to determine the distribution of the cell cycle phases in disaggregated Caco-2 spheroids by using cytofluorimetric analysis is also described. The optimized culturing protocol favors 3D Caco-2 spheroid differentiation process, as evaluated by the number of well-differentiated spheroids with a single hollow lumen. The cytofluorimetric analysis allows rapid collection of cell cycle phase data from high numbers of spheroid samples, thus, permitting to estimate their growth dynamics in a relatively short time. The optimized technical approaches described here can be applied in systematic manner to a variety of research activities utilizing 3D Caco-2 spheroids. Ease of use, time and economic saving advantages deriving from these protocols further highlight their potential.展开更多
文摘Aim The present study developed a CYP3A4-expressed Caco-2 monolayer model at which effects of the efflux-metabolism alliance on the transport and uptake of clausenamide（CLA） enantiomers as CYP3A4 substrates were investigated. The apparent permeability coefficients （Papp） of （ - ） and （ ＋ ）CLA were higher in the ab- sorptive direction than those in the secretory direction with efflux ratios（ER） of 0. 709 ± 0.411 and 0. 867± 0. 250 （ Х10^-6 -1 cm · s ）, respectively. Their bidirectional transports were significantly reduced by （75.6 ± 87.5）% af- ter treatment with verapamil （ a P-glycoprotein inhibitor） that increased the rate of metabolism by CYP3 A4, whereas the CYP3A4 inhibitor ketoconazole treatment markedly enhanced the basolateral to apical flux of （ - ） and （ ＋ ） CLA with ERs being 2. 934 ± 1. 432 and 1. 877 ± 0. 148 （ Х 10^-6 cm/s） respectively. These changes could be blocked by the duel CYP3A4/P-glycoprotein inhibitor cyclosporine A, consequently, Papp values for CLA enanti- omers in both directions were significantly greater than those obtained by using verapamil or ketoconazole, and their ERs were similar to those following （ - ） or （ ＋ ）-isomer treatment alone. Furthermore, the uptake of （ - ）CLA was more than that of （ ＋ ）CLA in the transfected cells. Incubation with ketoeonazole decreased the intracellular concentrations of the two enantiomers. This effect disappeared in the presence of a CYP3A4 inducer dexametha- sone. These results indicated that CYP3A4 could influence P-gp efflux, transport and uptake of CLA enantiomers as CYP3A4 substrates and that a duel inhibition to CYP3A4/ P-glycoprotein could enhance their absorption and bioavailability, which provides new insight into the efflux-metabolism alliance and will benefit the clinical pharma- cology of （？） CLA as a candidate drug for treatment of Alzheimer＇ s disease.
基金Supported by the Else Kroner-Fresenius Foundation, Bad Homburg, Germany
文摘AIM： To investigate the possible involvement of 25-hydroxyvitamin D3-1cx-hydroxylase [1α-25（OH）2D3] in butyrate-induced differentiation in human intestinal cell line Caco-2 cells. METHODS： Caco-2 cells were incubated either with 3 mmol/L butyrate and 1 umol/L 25（OH）2D3 or with 1 umol/L 1α-25（OH）2D3 for various time intervals ranging from 0 to 72 h. Additionally, cells were co-incubated with butyrate and either 25（OH）2D3 or 1α-25（OH）2D3. 1α-25（OH）2D3 mRNA was determined semi-quantitatively using the fluorescent dye PicoGreen. Immunoblotting was used for the detection of 1α-25（OH）2D3 protein. Finally, enzymatic activity was measured by ELISA. RESULTS： Both butyrate and 1α-25（OH）2D3 stimulated differentiation of Caco-2 cells after a 48 h incubation period, while 25（OH）2D3 had no impact on cell differentiation. Synergistic effects on differentiation were observed when cells were co-incubated with butyrate and vitamin D metabolite. Butyrate transiently upregulated 1α-25（OH）2D3 mRNA followed by a timely delayed protein upregulation. Coincidently, enzymatic activity was enhanced significantly. The induction of the enzyme allowed for comparable differentiating effects of both vitamin D metabolites. CONCLUSION： Our experimental data provide a further mechanism for the involvement of the vitamin D signaling pathway in colonic epithelial cell differentiation by butyrate. The enhancement of 1α-25（OH）2D3 followed by antiproliferative effects of the vitamin D prohormone in the Caco-2 cell line suggest that 25（OH）2D3 in combination with butyrate may offer a new therapeutic approach forthe treatment of colon cancer.
文摘3D （Three-dimensional） Caco-2 spheroids closely recapitulating in vivo physiological organization of intestinal epithelial cells, provide an excellent in vitro model system to study their pathophysiology and their response to stressful stimuli. The objective of this technical note is to provide optimized in vitro experimental protocols for culturing 3D Caco-2 spheroids and for analyzing their cell growth features. An optimized 3D Caco-2 spheroid culturing technique based on a new configuration of the culture medium is provided A methodological approach to determine the distribution of the cell cycle phases in disaggregated Caco-2 spheroids by using cytofluorimetric analysis is also described. The optimized culturing protocol favors 3D Caco-2 spheroid differentiation process, as evaluated by the number of well-differentiated spheroids with a single hollow lumen. The cytofluorimetric analysis allows rapid collection of cell cycle phase data from high numbers of spheroid samples, thus, permitting to estimate their growth dynamics in a relatively short time. The optimized technical approaches described here can be applied in systematic manner to a variety of research activities utilizing 3D Caco-2 spheroids. Ease of use, time and economic saving advantages deriving from these protocols further highlight their potential.
