Figure 1. β-arrestin-2 is upregulated in NEC in humans, mice and IECs. (A) Immunohistochemical staining demonstrated that β-arrestin-2 expression was greater in both humans and mice with NEC than in healthy controls. (B) β-arrestin-2 protein was detected in the neonatal intestine, and was upregulated in NEC samples from both humans (n=6) and mice (n=6). (C) LPS stimulation increased β-arrestin-2 expression in IEC-6 cells. (D) β-arrestin-2 expression was greater in premature than in full-term human infants (n=6). (E) In mice, β-arrestin-2 levels in the distal ileum trended down from embryonic day 15 (E15) to postnatal day 7 (P7) (n=6).