Diabetes during pregnancy enhanced neuronal death in the hippocampus of rat offspring.
BACKGROUND
Diabetes in pregnancy has a detrimental effect on central nervous system (CNS) development and is associated with an increased risk of short- and long-term neurocognitive impairment in the offspring. This study aimed to investigate the effect of maternal diabetes and also insulin treatment on the numerical density of apoptotic cells in rat neonate's hippocampi during the first two postnatal weeks.


METHODS
Wistar female rats were maintained diabetic from a week before gestation through parturition and their male pup's brains were collected at postnatal days (P); P0, P7 and P14, equivalent to the third trimester in human. Numerical density of total neurons and percentage of apoptotic (TUNEL-positive) cells in different subfields of hippocampus (CA1, CA2, CA3, and DG) was calculated by stereological methods.


RESULTS
Immediately after birth, we found a significantly decline in the total neuronal density only in hippocampal CA3 area in neonates born to diabetic animals (p<0.0001). Moreover, the number of neurons was significantly decreased in all hippocampal sub-regions of diabetic group pups when compared to control and insulin treated diabetic pups at both P7 and P14 (p<0.0001 each). Nevertheless, in diabetic group, the percentage of apoptotic cells in different subfields of hippocampus were higher in all studied time-points compared to control or insulin treated diabetic groups (p<0.0001 each). There were no significant differences either in the total number or apoptotic cells in the different hippocampal sub-fields between the insulin-treated diabetic group and controls (p>0.05).


CONCLUSIONS
Our data indicate that diabetes in pregnancy induce the neuronal cell apoptosis in offspring hippocampus. Furthermore, the maternal glycaemia control by insulin treatment in the most cases normalized these effects.
Microanatomy Research Center, School of Medicine, Mashhad University of Medical Sciences, Mashhad, Iran; Department of Anatomical Sciences, School of Medicine, Birjand University of Medical Sciences, Birjand, Iran; Depatrment of Anatomy and Molecular Biology, School of Medicine, Mashhad University of Medical Sciences, Mashhad, Iran.
Nassim
N
Lotfi
Department of Anatomical Sciences, School of Medicine, Birjand University of Medical Sciences, Birjand, Iran; Cellular and Molecular Research Center, Birjand University of Medical Sciences, Birjand, Iran.
Javad
J
Hami
Department of Public Health, Deputy of Research and Technology, Research Centre of Experimental Medicine, Birjand University of Medical Sciences, Birjand, Iran.
Mehran
M
Hosseini
Microanatomy Research Center, School of Medicine, Mashhad University of Medical Sciences, Mashhad, Iran.
Delaram
D
Haghir
Depatrment of Anatomy and Molecular Biology, School of Medicine, Mashhad University of Medical Sciences, Mashhad, Iran; Medical Genetic Center (MGRC), School of Medicine, Mashhad University of Medical Sciences, Mashhad, Iranh. Electronic address: Haghirh@mums.ac.ir.
Hossein
H
Haghir
D000367:Age Factors; D000704:Analysis of Variance; D000818:Animals; D000831:Animals, Newborn; D001786:Blood Glucose; D016923:Cell Death / Q000187:drug effects; D003921:Diabetes Mellitus, Experimental / Q000188:drug therapy / Q000473:pathology*; D004195:Disease Models, Animal; D005215:Fasting; D005260:Female; D006624:Hippocampus / Q000187:drug effects / Q000196:embryology / Q000254:growth & development / Q000473:pathology*; D007004:Hypoglycemic Agents / Q000627:therapeutic use; D020287:In Situ Nick-End Labeling; D007328:Insulin / Q000627:therapeutic use; D008297:Male; D009474:Neurons / Q000187:drug effects / Q000473:pathology*; D011247:Pregnancy; D011297:Prenatal Exposure Delayed Effects; D051381:Rats; D017208:Rats, Wistar
D001786:Blood Glucose; D007004:Hypoglycemic Agents; D007328:Insulin
Apoptosis; Hippocampus; Maternal diabetes; Neuronal density; Rat neonate