Effect of Transient Maternal Hypotension on Apoptotic Cell Death in Foetal Rat Brain

Abstract

Background: Intrauterine perfusion insufficiency induced by transient maternal hypotension has been reported to be associated with foetal brain malformations. However, the effects of maternal hypotension on apoptotic processes in the foetal brain have not been investigated experimentally during the intrauterine period. Aims: The aim of this study was to investigate the effects of transient maternal hypotension on apoptotic cell death in the intrauterine foetal brain. Study Design: Animal experimentation. Methods: Three-month-old female Wistar albino rats were allocated into four groups (n=5 each). The impact of hypoxic/ischemic injury induced by transient maternal hypotension on the 15th day of pregnancy (late gestation) in rats was investigated at 48 (H17 group) or 96 hours (H19 group) after the insult. Control groups underwent the same procedure except for induction of hypotension (C17 and H17 groups). Brain sections of one randomly selected foetus from each pregnant rat were histopathologically evaluated for hypoxic/ischemic injury in the metencephalon, diencephalon, and telencephalon by terminal transferase-mediated dUTP nick end labelling and active cysteine-dependent aspartate-directed protease-3 (caspase-3) positivity for cell death. Results: The number of terminal transferase-mediated dUTP nick end labelling (+) cells in all the areas examined was comparable in both hypotension and control groups. The H17 group had active caspase-3 (+) cells in the metencephalon and telencephalon, sparing diencephalon, whereas the C19 and H19 groups had active caspase-3 (+) cells in all three regions. The number of active caspase-3 (+) cells in the telencephalon in the H19 group was higher compared with the metencephalon and diencephalon and compared with H17 group (p<0.05). Conclusion: Our results suggest that prenatal hypoxic/ischemic injury triggers apoptotic mechanisms. Therefore, blockade of apoptotic pathways, considering the time pattern of the insult, may constitute a potential neuroprotective approach for the detrimental effects of prenatal hypoperfusion. (Balkan Med J 2014;31:88-94).

Keywords

• Apoptosis, foetal rat brain, hypotension, hypoxic/ischemic injury, pregnancy

Effect of Transient Maternal Hypotension on Apoptotic Cell Death in Foetal Rat Brain

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References

1. Ornoy A, Benady S, Kohen-Raz R, Russell A. Association between maternal bleeding during gestation and congenital anomalies in the off- spring. Am J Obstet Gynecol 1976;124:474-8.
2. Sanner G. Pathogenetic and preventive aspects of non-progressive atax- ic syndromes. Dev Med Child Neurol 1979;21:663-71. [CrossRef]
3. Apak RA, Anlar B, Atilla P, Cakar N. Transient intrauterine hypoten- sion: effect on newborn rat brain. Pediatr Res 2001;49:45-9. [CrossRef]
4. Lipson AH, Gillerot Y, Tannenberg AE, Giurgea S. Two cases of mater- nal antenatal splenic rupture and hypotension associated with Moebius syndrome and cerebral palsy in offspring. Further evidence for a utero placental vascular aetiology for the Moebius syndrome and some cases of cerebral palsy. Eur J Pediatr 1996;155:800-4. [CrossRef]
5. Lipson AH, Webster WS, Brown-Woodman PD, Osborn RA. Moebius syndrome:animal model--human correlations and evidence for a brain- stem vascular etiology. Teratology 1989;40:339-50. [CrossRef]
6. Farrell K, McGillivray BC. Arthrogryposis following maternal hypoten- sion. Dev Med Child Neurol 1983;25:648-50. [CrossRef]
7. Weyerts LK, Jones MC, James HE. Paraplegia and congenital con- tractures as a consequence of intrauterine trauma. Am J Med Genet 1992;43:751-2. [CrossRef]
8. Vexler ZS, Ferriero DM. Molecular and biochemical mechanisms of perinatal brain injury. Semin Neonatol 2001;6:99-108. [CrossRef]

9. Nakajima W, Ishida A, Lange MS, Gabrielson KL, Wilson MA, Martin LJ, et al. Apoptosis has a prolonged role in the neurodegeneration after hypoxic ischemia in the newborn rat. J Neurosci 2000;20:7994-8004.
10. Tombakoglu M, Durakoglugil M, Kale G, Orer HS, Bulun A, Anlar B. Transient intrauterine hypotension causes apoptosis in fetal rat brain and affects learning. Pediatr Res 2003;53:977-82. [CrossRef]
11. Bayrak S, Pehlivanoglu B, Balkanci ZD, Ozyurek H, Aksoy Y, Atilla P, et al. The effects of transient systemic hypotension on renal oxidative status, morphology and plasma nitric oxide levels in pregnant rats. J Matern Fetal Neonatal Med 2009;22:528-36. [CrossRef]
12. Cai Z, Xiao F, Lee B, Paul IA, Rhodes PG. Prenatal hypoxia-ischemia alters expression and activity of nitric oxide synthase in the young rat brain and causes learning deficits. Brain Res Bull 1999;49:359-65. [CrossRef]
13. Gavrieli Y, Sherman Y, Ben-Sasson SA. Identification of programmed cell death in situ via specific labeling of nuclear DNA fragmentation. J Cell Biol 1992;119:493-501. [CrossRef]
14. Koizumi H, Ohkawa I, Tsukahara T, Momoi T, Nakada K, Uchikoshi T. Apoptosis in favourable neuroblastomas is not dependent on Fas (CD95/APO-1) expression but on activated caspase 3 (CPP32). J Pathol 1999;189:410-5. [CrossRef]
15. Li Y, Powers C, Jiang N, Chopp M. Intact, injured, necrotic and apoptotic cells after focal cerebral ischemia in the rat. J Neurol Sci 1998;156:119- 32. [CrossRef]
16. Stefanis L. Caspase-dependent and -independent neuronal death:two distinct pathways to neuronal injury. Neuroscientist 2005;11:50-62. [CrossRef]
17. Edinger AL, Thompson CB. Death by design: apoptosis, necrosis and autophagy. Curr Opin Cell Biol 2004;16:663-9. [CrossRef]
18. Edwards AD, Mehmet H. Apoptosis in perinatal hypoxic-ischemic cere- bral damage. Neuropathol Appl Neurobiol 1996;22:494-8. [CrossRef]
19. Taylor DL, Edwards AD, Mehmet H. Oxidative metabolism, apoptosis and perinatal brain injury. Brain Pathol 1999;9:93-117. [CrossRef]
20. Northington FJ, Ferriero DM, Graham EM, Traystman RJ, Martin LJ. Early neurodegeneration after hypoxia-ischemia in neonatal rat is necrosis while delayed neuronal death is apoptosis. Neurobiol Dis 2001;8:207-19. [CrossRef]
21. Vexler ZS, Yenari MA. Does inflammation after stroke affect the devel- oping brain differently than adult brain? Dev Neurosci 2009;31:378-93. [CrossRef]
22. Hossain MA. Hypoxic-ischemic injury in neonatal brain:involvement of a novel neuronal molecule in neuronal cell death and potential target for neuroprotection. Int J Dev Neurosci 2008;26:93-101. [CrossRef]
23. Hill IE, MacManus JP, Rasquinha I, Tuor UI. DNA fragmentation in- dicative of apoptosis following unilateral cerebral hypoxia-ischemia in the neonatal rat. Brain Res 1995;676:398-403. [CrossRef]
24. Beilharz EJ, Williams CE, Dragunow M, Sirimanne ES, Gluckman PD. Mechanisms of delayed cell death following hypoxic-ischemic injury in the immature rat:evidence for apoptosis during selective neuronal loss. Brain Res Mol Brain Res 1995;29:1-14. [CrossRef]
25. Edwards AD, Yue X, Cox P, Hope PL, Azzopardi DV, Squier MV, et al. Apoptosis in the brains of infants suffering intrauterine cerebral injury. Pediatr Res 1997;42:684-9. [CrossRef]
26. Johnston MV. Excitotoxicity in neonatal hypoxia. Ment Retard Dev Dis- abil Res Rev 2001;7:229-34. [CrossRef]
27. Sidhu RS, Tuor UI, Del Bigio MR. Nuclear condensation and fragmentation following cerebral hypoxia-ischemia occurs more frequently in immature than older rats. Neurosci Lett 1997;223:129-32. [CrossRef]
28. Yue X, Mehmet H, Penrice J, Cooper C, Cady E, Wyatt JS, et al. Apop- tosis and necrosis in the newborn piglet brain following transient ce- rebral hypoxia-ischaemia. Neuropathol Appl Neurobiol 1997;23:16-25. [CrossRef]
29. Mallard EC, Gunn AJ, Williams CE, Johnston BM, Gluckman PD. Tran- sient umbilical cord occlusion causes hippocampal damage in the fetal sheep. Am J Obstet Gynecol 1992;167:1423-30. [CrossRef]
30. Mallard EC, Williams CE, Johnston BM, Gunning MI, Davis S, Gluck- man PD. Repeated episodes of umbilical cord occlusion in fetal sheep lead to preferential damage to the striatum and sensitize the heart to further insults. Pediatr Res 1995;37:707-13. [CrossRef]
31. Robinson S. Systemic prenatal insults disrupt telencephalon development: implications for potential interventions. Epilepsy Behav 2005;7:345-63. [CrossRef]
32. Back SA, Luo NL, Borenstein NS, Levine JM, Volpe JJ, Kinney HC. Late oligodendrocyte progenitors coincide with the developmental win- dow of vulnerability for human perinatal white matter injury. J Neurosci 2001;21:1302-12.