10.6084/m9.figshare.4785658.v1
Engels J.
Engels
J.
Elting N.
Elting
N.
Braun L.
Braun
L.
Bendix I.
Bendix
I.
Herz J.
Herz
J.
Felderhoff-Müser U.
Felderhoff-Müser
U.
Dzietko M.
Dzietko
M.
Supplementary Material for: Sildenafil Enhances Quantity of Immature Neurons and Promotes Functional Recovery in the Developing Ischemic Mouse Brain
Karger Publishers
2017
Phosphodiesterase 5
Cyclic guanosine monophosphate
Sildenafil
Hypoxia-ischemia
Developing brain
Neonatal mice
2017-03-24 11:35:43
Dataset
https://karger.figshare.com/articles/dataset/Supplementary_Material_for_Sildenafil_Enhances_Quantity_of_Immature_Neurons_and_Promotes_Functional_Recovery_in_the_Developing_Ischemic_Mouse_Brain/4785658
<p><b><i>Background:</i></b> Hypoxic-ischemic (HI) injury to the
developing brain occurs in 1 out of 1,000 live births and remains a
major cause of significant morbidity and mortality. A large number of
survivors suffer from long-term sequelae including seizures and
neurological deficits. However, the pathophysiological mechanisms of
recovery after HI insult are not clearly understood, and preventive
measures or clinical treatments are nonexistent or not sufficiently
effective in the clinical setting. Sildenafil as a specific
phosphodiesterase 5 inhibitor leads to increased levels of the second
messenger cyclic guanosine monophosphate (cGMP) and promotes functional
recovery and neurogenesis after ischemic injury to the adult brain. <b><i>Objective:</i></b>
Here, we investigated the effect of sildenafil treatment on activation
of intracellular signaling pathways, histological and neurogenic
response including functional recovery after an ischemic insult to the
developing brain. <b><i>Design/Methods:</i></b> Nine-day-old C57BL/6
mice were subjected either to sham operation or underwent ligation of
the right common carotid artery followed by hypoxia (8%) for 60 min.
Animals were either administered sildenafil (10 mg/kg, i.p.) or vehicle 2
h after hypoxia. A subgroup of animals received multiple injections of
10 mg/kg daily on 5 consecutive days. Pups were either perfusion fixed
at postnatal days 14 or 47 for immunohistochemical analysis, or brains
were dissected 2, 6, 12, and 24 h after the end of hypoxia and analyzed
for cGMP, pAkt, pGSK-3β, and β-catenin by means of ELISA or
immunoblotting. In addition, behavioral studies using the wire hang test
and elevated plus maze were conducted 21 and 38 days after HI injury. <b><i>Results:</i></b>
Based on cresyl violet staining, single or multiple sildenafil
injections did not reveal any differences in injury scoring compared to
sham animals. However, cerebral levels of cGMP were altered after
sildenafil therapy. Treatment significantly increased numbers of
immature neurons, as indicated by doublecortin immunoreactivity in the
ipsilateral subventricular zone and striatum. In addition, animals
treated with sildenafil after HI insult demonstrated improved functional
recovery. pAkt, pGSK-3β, and β-catenin levels vary after HI injury but
additional sildenafil treatment had no impact on protein expression
compared to the level of sham controls. <b><i>Conclusions:</i></b> Here,
we report that treatment with sildenafil after HI insult did not
improve histological brain injury scores. Nevertheless, our results
suggest involvement of the cGMP and PI3K/Akt/GSK-3β signaling pathway
with promotion of a neurogenic response and reduction of neurological
deficits. In summary, sildenafil may have a role in promoting recovery
from HI injury in the developing brain.</p>