CFTR deficiency delays inflammation resolution in vivo both by reducing neutrophil apoptosis and reverse migration of neutrophils. (A,B)Control and cftr MO larvae were amputated and stained with TUNEL/TSA to label apoptotic cells. (A) Representative confocal pictures of injured tails at 8 hpi (scale bars, 60 μm) revealing the proportion of apoptotic neutrophils at the wound (white arrow). (B) Quantification of neutrophil apoptosis rate at site of injury at 4 and 8 hpi. (n = 18–22, Fisher t-test). (C–F) Neutrophil reverse migration in control and cftr MO larvae. (C) Tail transection was performed on 3 dpf Tg(mpx:gal4)sh267;Tg(UASkaede)i222 larvae. The site of injury was photoconverted at 4 hpi, then the number of photoconverted neutrophils (red) moving away (white dotted box) from the wound (blue dotted box) were time-lapse imaged and quantified over 4 h post-photoconversion by confocal microscopy. (D) Representative confocal imaging of amputated tails showing the kinetics of photoconverted neutrophils that migrate away from photoconverted region over inflammation resolution. (E) Plot showing the number of photoconverted neutrophils leaving the area of injury over 4 h post photoconversion in control and cftr MO. Line of best fit shown is calculated by linear regression. P-value shown is for the difference between the 2 slopes (n = 12, performed as 3 independent experiments). (F) Representative confocal imaging of amputated tails showing the kinetics of new neutrophils (green) recruited towards site of injury after photoconversion. See also Supplementary Figure 3.
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