Lam, P.Y., Yoo, S.K., Green, J.M., and Huttenlocher, A. (2012) The SH2-domain-containing inositol 5-phosphatase (SHIP) limits neutrophil motility and wound recruitment in zebrafish. Journal of Cell Science. 125(21):4973-4978.
Neutrophil recruitment to sites of injury or infection is essential for host defense, but it needs to be tightly regulated
to prevent tissue damage. Phosphoinositide 3-kinase (PI3K), that generates the phosphoinositide PI(3,4,5)P3, is necessary for neutrophil motility in vivo, however, the role of SH2-domain–containing 5-inositol phosphatase (SHIP) enzymes,
that hydrolyzes PI(3,4,5)P3 to PI(3,4)P2, is not well understood. Here we show that SHIP phosphatases limit neutrophil motility in live zebrafish. Using real-time
imaging of bioprobes specific for PI(3,4,5)P3 and PI(3,4)P2 in neutrophils, we found that PI(3,4,5)P3 and PI(3,4)P2 accumulate at the leading edge while PI(3,4)P2 also localizes to the trailing edge of migrating neutrophils in vivo. Depletion of SHIP phosphatases using morpholinos led
to increased neutrophil 3D motility and neutrophil infiltration into wounds. The increase in neutrophil wound recruitment
in SHIP morphants was rescued by treatment with low dose PI3Kγ inhibitor, suggesting that SHIP limits neutrophil motility by modulating
PI3K signaling. Moreover, overexpression of the SHIP phosphatase domain in neutrophils impaired neutrophil 3D migration. Taken
together, our findings suggest that SHIP phosphatases control neutrophil inflammation by limiting neutrophil motility in vivo.