Given a passage with a context and an answer, 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.

[Q]: Context: The checkpoint kinase 1 (Chk1) functions not only in genotoxic stresses but also in normal cell cycle progression, particularly in the initiation, progression and fidelity of unperturbed mitosis. In this study, we investigated the role of Chk1 in regulating the metaphase-anaphase transition in mammalian cells.', 'The mitotic progression was monitored by flow cytometry analysis. The levels of cyclin B1, Cdc20 and Mad2 were measured by Western blotting. Metaphase chromosome alignment and the subcellular localization of Cdc20 and Mad2 were analyzed by immunofluorescence and confocal microscopy.', 'Cyclin B1 degradation and the metaphase-anaphase transition were severely blocked by Chk1 siRNA. Depletion of Chk1 induced chromosome alignment defect in metaphase cells. The kinetochore localization of Cdc20, Mad2 was disrupted in Chk1 depleted cells. Chk1 abrogation also dramatically reduced the protein expression levels of Cdc20 and Mad2.
Answer: These results strongly suggest that Chk1 is required for the metaphase-anaphase transition via regulating the subcellular localization and the expression of Cdc20 and Mad2.
[A]: Is chk1 required for the metaphase-anaphase transition via regulating the expression and localization of Cdc20 and Mad2?


[Q]: Context: Disruptions to intermyocyte coupling have been implicated in arrhythmogenesis and development of conduction disturbances. At present, understanding of the relationship between the microscopic organization of intercellular coupling and the macroscopic spread of impulse in the normal and diseased heart is largely confined to theoretical analyses.', 'The abundance and arrangement of gap junctions, as well as conduction properties, were assessed in terminal crest preparations isolated from the atria of neonate, weanling, and adult rabbits. We report that the connexin composition of terminal crest was uncomplicated, with Cx43 being the most prominent isoform detectable by Western blotting and immunostaining. Terminal crest myocytes showed little change in total Cx43-gap junction per cell during postnatal growth as assessed by stereology. However, marked non-uniformities emerged in the sarcolemmal distribution of Cx43-gap junctions. Cx43-gap junction area at myocyte termini increased 3.5-fold from birth to adulthood. Correlated with this change in Cx43, impulse propagation velocity parallel to the myofiber axis, as assessed by multi-site optical mapping using voltage-sensitive dye (di-4-ANEPPS), increased 2.4-fold. Conversely, the amount of Cx43-gap junctions on myocyte sides, and the conduction velocity transverse to the myofiber axis, remained relatively invariant during maturation. Hence, the increasing electrical anisotropy of maturing terminal crest was wholly accounted for by increases in conductance velocity along the bundle. This increase in longitudinal conduction velocity was correlated with changes in the sarcolemmal pattern, but not the overall density, of Cx43-gap junctions.
Answer: This study provides the first correlative structure/function analysis of the relationship between the macroscopic conduction of impulse and the microscopic cellular organization of gap junctions in a differentiating cardiac bundle. Confirmation is provided for theoretical predictions which emphasize the importance of the cell-to-cell geometry of coupling in determining the spread and pattern of myocardial activation.
[A]: Are the rate and anisotropy of impulse propagation in the postnatal terminal crest correlated with remodeling of Cx43 gap junction pattern?


[Q]: Context: Impaired resolution of acute inflammation results in development of chronic inflammatory disorders such as atherosclerosis, asthma and arthritis. Clearance of apoptotic neutrophils by M2 macrophages, the process termed efferocytosis, is critical for complete resolution of inflammation as it prevents secondary necrosis caused by disgorgement of toxic contents from apoptotic cells in the inflamed site. In the present study, we investigated the effect of docosahexaenoic acid (DHA) on efferocytosis.', 'To determine the effect of DHA on efferocytosis, murine macrophage-like RAW264.7 cells were co-incubated with apoptotic Jurkat T cells, and efferocytosis was assessed by flow cytometry. The expression and production of M1 and M2 markers were determined by RT-PCR, ELISA and flow cytometry. To demonstrate the involvement of peroxisome proliferator-activated receptor γ (PPARγ) in DHA-mediated effects, siRNA against PPARγ was utilized. The expression of PPARγ was examined by semiquantitative reverse-transcription polymerase chain reaction (RT-PCR), Western blot analysis and immunocytochemistry. The PPARγ activation was measured by the electrophilic gel shift assay.', 'DHA enhanced the efferocytic ability of RAW264.7 cells, and induced their M2 polarization. Notably, knockdown of PPARγ abolished the stimulatory effect of DHA on M2 polarization as well as efferocytosis. Furthermore, lipopolysaccharide-induced production of pro-inflammatory cytokines was significantly inhibited by DHA, suggesting that DHA alters the macrophage phenotype in favor of M2 while it suppresses M1 polarization.
Answer: These findings indicate that DHA can promote resolution of inflammation by facilitating efferocytosis through M2 macrophage polarization. Therefore, DHA may have a therapeutic potential in the management of inflammatory diseases which are related to impaired resolution of inflammation.
[A]:
Does docosahexaenoic acid induce M2 macrophage polarization through peroxisome proliferator-activated receptor γ activation?