Fig. 2.
Collagen and Periostin expression in adult mouse heart valve and skin. A: The entire left AV valve leaflet was micro-dissected from an adult mouse heart and stained for collagen using picrosirius red. Collagen expression is seen throughout the valve leaflet (VL), the chordae tendineae (CT) and annulus fibrosae (AF). The intense red staining indicates mature collagen fibers whereas the yellow stain shows less highly cross-linked fibers. B: The murine left AV valve leaflet was microdissected and stained in whole mount for periostin. Notice the extensive overlap in expression between periostin and collagen. C: Periostin expression in the adult mouse heart valve. Immunohistochemistry of a frontal section through an adult heart stained for periostin expression shows intense expression (green staining) within the chordae tendineae (CT). No expression is evident in the muscular left ventricle (LV) or in the papillary muscle (PM). MF20 staining was used to stain muscle (red staining). D: Immunostaining of periostin in adult mouse skin. Periostin (green staining) expression is seen throughout the various layers of the skin and is concentrated in areas surrounding the sebaceous glands (SeG) and the sweat glands (SG); HP-hypodermis.