The cutaneous wound healing reaction occurs in overlapping but inter-related
phases which finally involves fibrosis. The pathophysiological mechanisms involved in
fibrotic diseases, including those organ-related or even systemic, like systemic sclerosis,
could represent the successive systemic upregulation of extraembryonic-like
phenotypes, i.e.: amniotic and vitelline. These two extraembryonic-like phenotypes
would focus on the injured tissue to induce a process similar to that occurs in the early
phases of embryo development, which is gastrulation. The amniotic-like phenotype
would play a leading role in the development of a neurogenic response with noteworthy
hydroelectrolytic alterations that essentially would represent the creation of an open
microcirculation in the injured tissue. In turn, through the overlapped expression of a
vitelline-like phenotype, a bone-marrow-related response is produced. The interstitial
infiltration by molecular and cellular mediators contributed by the amniotic- and
vitelline-like functions provides the functional and metabolic autonomy which is needed
for inducing the formation of a new tissue by using mechanisms similar to those
expressed in gastrulation during the early phases of the embryo development. Thus, a
new tissue is formed but unfortunately it quickly evolves by premature senescence to
fibrosis. The hypothesized use of mechanisms is related to extraembryonic-like
functions in the three following physiological and pathological processes: the
embryonic development; the wound healing reaction during adult life and, finally in
senescence, where the existence of a basic self-organizing fractal-like functional pattern
as an essential characteristic of our way of life is suggested.
Keywords: Wound healing, embryo development, vitelline, clot, coagulation,
hemostasis, re-epithelization, amniotic fluid, extraembryonic functions,
intraembryonic mesenchyma, leukocytes, microcirculation, senescence, interstitium.