Neuroserpin As an Adjuvant Therapy for Hypothermia on Brain Injury in Neonatal Hypoxic-Ischemic Rats

Hasan Kilicdag; Kubra Akillioglu; Emine Kilic Bagır; Seda Kose; Seyda Erdogan

doi:10.1055/a-2159-0488

Neuroserpin As an Adjuvant Therapy for Hypothermia on Brain Injury in Neonatal Hypoxic-Ischemic Rats

Am J Perinatol. 2023 Sep 25. doi: 10.1055/a-2159-0488. Online ahead of print.

Authors

Hasan Kilicdag¹, Kubra Akillioglu², Emine Kilic Bagır³, Seda Kose², Seyda Erdogan³

Affiliations

¹ Division of Neonatology, Department of Pediatrics, Baskent University Faculty of Medicine, Ankara, Turkey.
² Division of Neurophysiology, Department of Physiology, Medical Faculty, University of Cukurova, Turkey.
³ Department of Pathology, Cukurova University, Medical Faculty, Adana, Turkey.

PMID: 37611639
DOI: 10.1055/a-2159-0488

Abstract

Objective: We aimed to assess the effects of neuroserpin and its combination with hypothermia on hypoxic-ischemic (HI) brain injury in neonatal rats. Neuroserpin is an axon-secreted serine protease inhibitor and is important for brain development, neuronal survival, and synaptic plasticity.

Study design: Male Wistar-Albino rats on postnatal day 7 (P7) were randomly divided into five groups: sham group (n = 10), (HI; n = 10), hypoxic-ischemic hypothermia (HIH; n = 10), hypoxic-ischemic neuroserpin (HIN; n = 10), and hypoxic-ischemic neuroserpin-hypothermia (HINH; n = 10). The P7 rat brain's maturation is similar to a late preterm human brain at 34 to 36 weeks of gestation. HI was induced in rats on P7 as previously described. A single dose of 0.2 µM neuroserpin (HINH and HIN) or an equivalent volume of phosphate-buffered saline (sham, HIH, and HI) was administered intraventricularly by a Hamilton syringe immediately after hypoxia. In the follow-up, pups were subjected to systemic hypothermia or normothermia for 2 hours. Euthanasia was performed for histopathological evaluation on P10. Apoptosis was detected by caspase-3 activity and terminal deoxynucleotidyl transferase-mediated dUTP nick end-labeling (TUNEL) staining and was counted in the hippocampus.

Results: In comparison to the HI group, the TUNEL-positive and caspase-3-positive neurons in the sham, HIN, HIH, and HINH groups were considerably lower (13.4 ± 1.0 vs. 1.9 ± 0.9, 6.0 ± 0.9, 5.3 ± 1.6, and 4.0 ± 1.1; p < 0.001) and (13.5 ± 1.7 vs. 1.2 ± 0.7, 9.1 ± 2.7, 4.8 ± 1.0, and 3.9 ± 1.6; p < 0.001). HIN, HIH, and HINH, compared to the sham group, showed more TUNEL-positive and caspase-3-positive neurons (6.0 ± 0.9, 5.3 ± 1.6, 4.0 ± 1.1 vs. 1.9 ± 0.9 and 9.1 ± 2.7, 4.8 ± 1.0, 3.9 ± 1.6 vs. 1.2 ± 0.7; p < 0.001). The HINH group (synergistic effect) had significantly fewer TUNEL-positive neurons and caspase-3-positive neurons than the HIN group (4.0 ± 1.1vs. 6.0 ± 0.9 and 3.9 ± 1.6 vs. 9.1 ± 2.7; p < 0.001).

Conclusion: Our study showed that both neuroserpin alone and as an adjuvant treatment for hypothermia may have a neuroprotective effect on brain injury.

Key points: · Neuroserpin decreased brain injury.. · Neuroserpin showed a synergistic effect when used as an adjuvant treatment for hypothermia.. · The neuroprotective effect of neuroserpine was related to its antiapoptotic properties..