Ablation of collagen 1α2 producing cells by NFP impair caudal fin regeneration and vascular development. In the control animals, at 3dpa and 7dpa, classical tissue regeneration pattern and blood vessel morphology are documented (a, c). Multiple active cells producing collagen 1α2 (in red) are present adjacent to the amputation line (a’, a’’, c’). Those cells are not detectible in NFP inhibited animals (b, b’, d, d’). Regenerative area and vascular plexus appear shorter and underdeveloped in the NFP-treated group at both, 3dpa and 7dpa. Arrows indicated sprouts. Green - ECs, red dotted line - amputation plane, images acquired by fluorescent reflected light microscope. a’’ part of a’ at higher magnification. Quantification of the regeneration and vascularization after the elimination of the collagen 1α2 producing cells has been performed by three variables: Total regenerated area (TRA = regenerated fin in mm2; (e), vascular projection area (VPA = vessels growth within regenerated fin in mm2; (f) and vessel area density (VAD = vessels density within the regenerated fin in %; g) during the period of 30 days in control group (blue) versus NFP-treated group (red). n = 5.
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