Fig. 2.

Effect of human amnion connective tissue on the secretion of apoB and apoA1 and cellular MTP activity. Panels A and B: Secretion of apoB and apoA1 by Caco-2 cells cultured on HACT. Caco-2 cells were cultured for 14 days on uncoated Transwell^® filters, or on HACT (Amnion CT). Eighteen hours prior to collection, the basal medium was exchanged with fresh DMEM+1% FBS, and the apical medium was replaced with DMEM+10% FBS. Basolateral media were used to measure apoB (A, *p<0.0001) or apoAI (B) using ELISA. Panels C and D: Time course of apoB and apoA1 secretion by Caco-2 cells cultured on HACT. The basal medium was exchanged with fresh DMEM containing 1% FBS 18 h prior to each collection time. At the times indicated, basal medium was collected and immediately assayed by ELISA for apoB (C, *p<0.0001, **p<0.0002, ***p<0.004, ****p<0.006) or apoA1 (D). Average±s.d. values are plotted against time (n=4). Panels E and F: Secretion of different apoB-lipoproteins by Caco-2 cells cultured on HACT. Eighteen hours prior to collection, the basal medium was exchanged with fresh DMEM+1% FBS, and the apical medium was replaced with DMEM+10% FBS+0.5 mM taurocholate (panel E) or DMEM+10% FBS supplemented with 1.6 mM oleic acid:0.5 mM taurocholate (panel F). Basal medium was collected and immediately fractionated by density gradient centrifugation and the fractions were assayed by ELISA for apoB. The data are from one experiment and are representative of three independent experiments. Panel G: Activity of microsomal triglyceride transfer protein (MTP) in Caco-2 cells cultured on HACT. Cells were washed and used to measure triglyceride transfer activity of MTP. Data are representative of three independent experiments performed in triplicate.