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Inhibition of the PI3K/Akt signaling pathway impedes the restoration of neurological function following hypoxic‐ischemic brain damage in a neonatal rabbit model
Author(s) -
Luo Zhihua,
Zhang Min,
Niu Xia,
Wu De,
Tang Jiulai
Publication year - 2019
Publication title -
journal of cellular biochemistry
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.028
H-Index - 165
eISSN - 1097-4644
pISSN - 0730-2312
DOI - 10.1002/jcb.28302
Subject(s) - pi3k/akt/mtor pathway , tunel assay , protein kinase b , brain damage , medicine , terminal deoxynucleotidyl transferase , apoptosis , anesthesia , endocrinology , pathology , andrology , biology , immunohistochemistry , biochemistry
Objective Hypoxic‐ischemic brain damage (HIBD), frequently occurring in infancy and childhood, is a major cause of mortality and severe neurologic impairment. This study was performed to examine the effect of the PI3K/Akt signaling pathway on HIBD in a neonatal rabbit model. Materials and Methods Uterine artery occlusion was used to establish HIBD models in neonatal rabbits, which were then subjected to sham operation, dimethyl sulfoxide (2 mL) or LY294002 (inhibitor of PI3K/Akt signaling pathway, 6.4 μg/kg). Behavioral neurological assessment was performed in neonatal rabbits delivered by cesarean section, after which serum neuron‐specific enolase (NSE) level and cerebral water content were determined. The level of cleaved caspase‐3 level and apoptosis of neurons were observed by immunohistochemistry and terminal deoxynucleotidyl transferase‐mediated dUTP nick‐end labeling (TUNEL) staining. Furthermore, the expression of PI3K/Akt signaling pathway‐ and apoptosis‐related factors was examined. Results In neonatal rabbits, HIBD increased the fetal death rate; reduced neurological scores of posture, righting reflex, and deglutition reflex; elevated serum NSE levels, cerebral water content, cleaved caspase‐3‐positive expression in hippocampal CA1 region and apoptotic neurons; inactivated PI3K/Akt signaling pathway as well as reduced Bcl‐2 expression and increased BAD and Bax expression. Notably, the treatment of LY294002 further aggravated neurological impairment in neonatal rabbits in response to HIBD. Conclusion Following the HIBD caused by intrauterine asphyxia, the LY294002 administered through auricular vein infusion into pregnant rabbits exacerbates neurological impairment of neonatal rabbits, suggesting that inhibition of PI3K/Akt signaling pathway may serve as a candidate therapeutic target for neurological recovery.