FIG 4.

CXCL1 expression in activated valvular interstitial cells (VIC) and the induction of neutrophil migration. (A and B) The production of CXCL1 was examined in VIC stimulated with glucosyltransferase (GTF; n = 14) (A) and IL-17 (n = 12) (B). (C) Neutrophil (Neu) migration experiments were performed using resting or activated conditioned media (CM), with or without CXCL1 neutralizing antibody (n = 6). Statistically significant differences between columns, as determined by Student's t test, are indicated by asterisks (*, P < 0.05; ***, P < 0.001). (D and E) Immunostaining of α-SMA and CXCL1 (D) or of SMA and elastase (E) in an infected valve. VIC are indicated by α-SMA-positive cells (red); CXCL1- and elastase-expressing cells are indicated in green (original magnification, ×400; scale bar, 25 μm).