ESSM Newsletter # 33

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10 ESSMToday
Have you read ? Best of the Best: Basic Research
the study used only rats that exhibited impaired
erectile responses to subcutaneous injection of
apomorphine at this time. Then, they compared
the efficacy of intracavernosal injection of ADSC
cultured under normoxic standard conditions
(20% O2) to ADSC cultured in gas controlled
chamber under 1% O2 conditions for 24h, as a
way to induce hypoxia precondition, in improving
erectile responses and cavernosal histology in
diabetic rats. Outcome was evaluated 4 weeks
after injection.
The ADSC obtained from rats of the same strain
were characterized by detecting the expression
of stem cell markers in its surface and by the
ability to undergo adipogenic and osteogenic
differentiation. The improvement of erectile re-
sponses in diabetic rats receiving intracavernosal
injection of ADSC with hypoxic preconditioning
was superior to that obtained with injection of
normoxic ADSC. This could be related to the in-
crease in expression of angiogenic (HIF-1α, VEGF,
angiopoietin-1, FGF-2), neurotrophic (BNDF,
GDNF) and regenerative (SDF-1, CXCR4) factors
induced by hypoxia in cultures of ADSC, which
could explain the elevated survival of ADSC in
cavernosal tissue 4 weeks after injection when
these cells were cultured in hypoxic conditions.
The greater improvement of erectile function
achieved with ADSC injection after hypoxic pre-
condition was also associated with less fibrosis
and immune cell infiltration in cavernosal tissue
as well as with increased expression of endothe-
lium and smooth muscle markers.
The study by Wang and collaborators suggests
that a relatively easy manipulation of the stem
cells culture consisting of hypoxic precondi-
tioning before their intracavernosal injec-
tion may enhance the therapeutic efficacy
in reversing ED in diabetic rats. In fact, other
manipulations of stem cells have been proposed
to enhance its efficacy in improving erectile re-
sponses in ED models, from gene delivery of
neurotrophic or vasoactive factors, and clonal
selection to the addition of adequate matrix.
However, several issues should be outweighed
considering the use of cell therapy in each
specific type of ED. Although cavernous nerve
injury (after prostatectomy for instance) involves
a punctual insult that, if solved, it will not be
persistent, diabetic ED represents a very dif-
ferent situation. Most of studies evaluating cell
therapy do not contemplate the termination of
the therapeutic effect of stem cell injection in
ED models where the pathogenic mechanism
of ED is persistent such as in diabetes. One
would think that, if diabetic condition is still
present, further injections of ADSC would
be required. This is an interesting startpoint
to analyze in future research the time-course
of the effects of cell therapy in these types
of ED models.
The ESSM School of
Sexual Medicine 2015
16–25 October 2015
Budapest, Hungary
ESSM
European Society for
Sexual Medicine