Preclinical Study of the Neuroprotective Effects of Pharmacological Agent-Modulators of HSP70 After Intrauterine Hypoxia

Abstract

Background: Chronic intrauterine hypoxia (IUH) is a cause not only of early postnatal mortality but also of delayed central nervous system (CNS) impairments in offspring, including increased risks of acute cerebrovascular disorders, epilepsy, and neurodegenerative diseases. The above necessitates the urgent development of targeted neuroprotective strategies for newborns following IUH. The aim of the present study was to evaluate the neuroprotective effects of the 70 kDa heat shock protein (HSP70) modulators (angiolin, thiotriazolin, cerebrocurin, tamoxifen, glutaredoxin, and heat shock factor 1 (HSF-1)), as well as reference drugs, based on their impact on molecular markers of endothelial dysfunction (vascular endothelial growth factor A (VEGF-A), endothelial nitric oxide synthase (eNOS), inducible nitric oxide synthase (iNOS), nitrotyrosine), brain-derived neurotrophic factor (BDNF), nerve growth factor (NGF), and caspase-8 in the brains of offspring after IUH at 1 and 2 months of age. Methods: Chronic hemic IUH was modeled in pregnant rats by daily administration of sodium nitrite (50 mg/kg, intraperitoneally) on days 16–21 of pregnancy. The male offspring were treated with the study drugs for 30 days starting on P1. Brain homogenates of offspring at P30 and P60 were analyzed using enzyme-linked immunosorbent assay (ELISA) for VEGF-A, eNOS, iNOS, nitrotyrosine, BDNF, NGF, and caspase-8. Results: IUH caused persistent endothelial dysfunction, characterized by decreased VEGF and eNOS levels, and nitrosative stress, associated with increased iNOS and nitrotyrosine levels. These changes were accompanied by decreased neurotrophin levels, including BDNF and NGF, and increased caspase-8 levels. Course administration of angiolin, cerebrocurin, HSF-1, thiotriazolin, and glutaredoxin improved the eNOS/iNOS balance, increased VEGF levels, and decreased nitrotyrosine levels, with the effect persisting until P60. Cerebrocurin and angiolin demonstrated the strongest recovery of neurotrophic factors (normalization or exceeding normal BDNF/NGF levels by P60) and effectively suppressed caspase-8 to near-normal levels. A positive correlation was established between BDNF, NGF, and HSP70 levels. Conclusions: Pharmacological modulators of HSP70 provide effective multimodal neuroprotection due to endothelioprotective and neurotrophic effects. Angiolin and Cerebrocurin demonstrate significant therapeutic potential, offering a promising strategy for mitigating the long-term neurological sequelae of IUH.