TASK DEFINITION: Given a passage, construct a question on the basis of the information present in the passage. Construct the question in such a way that (i) it is unambiguous, (ii) it is answerable from the passage, (iii) its answer is unique (iv) it answer uses text phrases from the passage. Avoid creating questions that (i) can't be answered correctly without actually understanding the passage and (ii) uses the same words or phrases given in the passage.
PROBLEM: To investigate the effects of copper on permeability and P-glycoprotein (P-gp) of Caco-2 cell monolayers.', 'The differentiated Caco-2 cell model was used in this study. Permeability of cell monolayers was reflected by monitoring transepithelial electrical resistance (TEER); distribution of tight junctional protein ZO-1 was measured by immunofluorescent staining; F actin was measured by fluorescence staining; and Activity of P-gp was reflected by changes of transcellular transport and accumulation of Rho-123 in Caco-2 cells.', "Apical treatment with copper (30 - 100 micromol/L, Hanks' buffered salt solution, up to 3 hours) induced a time- and concentration-dependent increase in permeability reflected by progressive decrease of TEER of Caco-2 cell monolayers, accompanied by deorganization of F actin, but without significant effects on tight junctional protein ZO-1; at a dose without any adverse effects on viability and permeability of Caco-2 monolayers, copper treatment (300 micromol/L, complete medium, 24 hours) decreased Papp(BL-->AP) from 7.37 +/- 0.20 x 10(-6) cm/s (controls) to (6.43 +/- 0.27) x 10(-6) cm/s, the increased Papp(AP-->BL) from (1.23 +/- 0.05) x 10(-7) cm/s (controls) to (3.41 +/- 0.08) x 10(-7) cm/s, and enhanced the intracellular Rho-123 from (0.31 +/- 0.01) nmol/filter (controls) to (0.50 +/- 0.03) nmol/filter.

SOLUTION: Does [ Copper treatment alter the barrier functions of human intestinal Caco-2 cells ]?

PROBLEM: Atractylodes macrocephala Koidz (AMK), a valuable traditional Chinese herbal medicine, has been widely used in clinical practice for treating patients with disorders of the digestive system. AMK has shown noteworthy promoting effect on improving gastrointestinal function and immunity, which might represent a promising candidate for the treatment of intestinal mucosa injury. The aim of this study was to investigate the efficacy of AMK on intestinal mucosal restitution and the underlying mechanisms via intestinal epithelial (IEC-6) cell migration model.', 'A cell migration model of IEC-6 cells was induced by a single-edge razor blade along the diameter of the cell layers in six-well polystyrene plates. After wounding, the cells were grown in control cultures and in cultures containing spermidine (5μM, SPD, reference drug), alpha-difluoromethylornithine (2.5mM, DFMO, polyamine inhibitor), AMK (50, 100, and 200mg/L), DFMO plus SPD and DFMO plus AMK for 12h. The polyamines content was detected by high-performance liquid chromatography (HPLC) with pre-column derivatization. The Rho mRNAs expression levels were assessed by Q-RT-PCR. The Rho and non-muscle myosin II proteins expression levels were analyzed by Western blot. The formation and distribution of non-muscle myosin II stress fibers were monitored with immunostaining techniques using specific antibodies and observed by confocal microscopy. Cell migration assay was carried out using inverted microscope and the Image-Pro Plus software. All of these indexes were used to evaluate the effectiveness of AMK.', '(1) Treatment with AMK caused significant increases in cellular polyamines content and Rho mRNAs and proteins expression levels, as compared to control group. Furthermore, AMK exposure increased non-muscle myosin II protein expression levels and formation of non-muscle myosin II stress fibers, and resulted in an acceleration of cell migration in IEC-6 cells. (2) Depletion of cellular polyamines by DFMO resulted in a decrease of cellular polyamines levels, Rho mRNAs and proteins expression, non-muscle myosin II protein formation and distribution, thereby inhibiting IEC-6 cell migration. AMK not only reversed the inhibitory effects of DFMO on the polyamines content, Rho mRNAs and proteins expression, non-muscle myosin II protein formation and distribution, but also restored cell migration to control levels.

SOLUTION: Does atractylodes macrocephala Koidz stimulate intestinal epithelial cell migration through a polyamine dependent mechanism?

PROBLEM: Platelet-activating factor (PAF) is a potent stimulator of eosinophils. Recently, treatment with a protein kinase C (PKC) inhibitor which generally inhibits PKC isoforms has been shown to modulate several eosinophil functions in distinct manners, in that PKC inhibition enhanced CD11b expression and cellular adhesion, but inhibited superoxide generation and degranulation in PAF-stimulated human eosinophils. These results suggested that distinct PKC isoforms were likely to be involved in each eosinophil function induced by PAF. We have therefore investigated whether or not the PKC isoforms involved in PAF-induced CD11b expression and superoxide generation were different.', 'Human eosinophils prepared from healthy volunteers were treated with PKC inhibitors, bis-indolylmaleimide I (BisI; a general PKC inhibitor), myristoylated PKC inhibitor peptide (myr-psiPKC; a PKCalpha, beta and delta inhibitor) and rottlerin (a PKCdelta inhibitor), followed by stimulation with PAF. CD11b expression was determined using flow cytometry and superoxide generation was evaluated using a cytochrome c reduction assay.', 'BisI treatment led to enhancement of PAF-induced CD11b expression, while myr-psiPKC and rottlerin did not. In contrast, PAF-induced superoxide generation was inhibited by treatment with BisI, myr-psiPKC and rottlerin.

SOLUTION:
Are distinct isoforms of protein kinase C involved in human eosinophil functions induced by platelet-activating factor?