Figure 3.
Morphologic analysis of vessels in skin and skeletal muscle of the proband as compared to control and CADASIL patient
- A–C Histopathological examination of skin (A) and skeletal muscle biopsies (B, C) of control (left), proband (middle) and CADASIL patient (right). (A) Collagen IV staining (in green) in skin vessels: Collagen wall appears compact in the control, while it is disorganized in the skin vessels of the proband and of the CADASIL patient. Derangement of the collagen wall in single collagen fibers is more evident in the proband than in the CADASIL patient, where collagen wall is quite compact. Vessel's endothelium is delineated by ULEX staining (in red). Collagen IV staining in skeletal muscle vessels (B) recapitulates the skin picture. Smooth muscle actin immunostaining of skeletal muscle biopsies (C) shows attenuated SMCs in the tunica media of both the proband and the CADASIL patient, with foci characterized by a complete SMCs loss (particularly in the CADASIL patient) and thinning of the vessel wall (arrows).
- D, E Ultrastructural analysis of skin biopsies. (D) Skin biopsy of the proband: (left panel) At low magnification, the tunica media of a vessel shows irregular SMCs surrounded by a markedly thickened basal membrane with a multilayered aspect (arrows); SMCs are identified by the presence of “focal adhesions” (square boxes); (middle panel) collagen fibrils appear organized in a parallel pathway along SMC (arrow), note the “focal adhesions” (square box); (right panel) collagen fibrils (“CF”) are more represented in dense bundles than elastic ones (“E”). No GOM is detected, in contrast to CADASIL patient (E), showing deposits of granular osmiophilic material (arrows) located between SMC plasmalemma and basal lamina.
- F KCNA5 immunostaining of skeletal muscle biopsies of control (left), proband (middle) and CADASIL patient (right). A global decrease in reactivity is evident in the vessels of both the proband and the CADASIL patient. Note multiple areas in which KCNA5 is barely detectable (arrows).