Antenatal Dexamethasone Treatment Induces Sex-dependent Upregulation of NTPDase1/CD39 and Ecto-5'-nucleotidase/CD73 in the Rat Fetal Brain.

Milica Manojlovic-Stojanoski,Jean Sévigny,Svetlana Trifunovic,Danijela Laketa,Natasa Nestorovic,Ivana Stevanovic,Natasa Ristic,Irena Lavrnja,Nadezda Nedeljkovic

doi:10.1007/s10571-021-01081-8

Abstract

Dexamethasone (DEX) is frequently used to treat women at risk of preterm delivery, but although indispensable for the completion of organ maturation in the fetus, antenatal DEX treatment may exert adverse sex-dimorphic neurodevelopmental effects. Literature findings implicated oxidative stress in adverse effects of DEX treatment. Purinergic signaling is involved in neurodevelopment and controlled by ectonucleotidases, among which in the brain the most abundant are ectonucleoside triphosphate diphosphohydrolase 1 (NTPDase1/CD39) and ecto-5'-nucleotidase (e5'NT/CD73), which jointly dephosphorylate ATP to adenosine. They are also involved in cell adhesion and migration, processes integral to brain development. Upregulation of CD39 and CD73 after DEX treatment was reported in adult rat hippocampus. We investigated the effects of maternal DEX treatment on CD39 and CD73 expression and enzymatic activity in the rat fetal brain of both sexes, in the context of oxidative status of the brain tissue. Fetuses were obtained at embryonic day (ED) 21, from Wistar rat dams treated with 0.5mg DEX/kg/day, at ED 16, 17, and 18, and brains were processed and used for further analysis. Sex-specific increase in CD39 and CD73 expression and in the corresponding enzyme activities was induced in the brain of antenatally DEX-treated fetuses, more prominently in males. The oxidative stress induction after antenatal DEX treatment was confirmed in both sexes, although showing a slight bias in males. Due to the involvement of purinergic system in crucial neurodevelopmental processes, future investigations are needed to determine the role of these observed changes in the adverse effects of antenatal DEX treatment.

Highlights

Glucocorticoids (GCs - cortisol in humans, corticosterone in rodents) play a crucial role in a proper and timely completion of organogenesis during fetal development in the maturation of lungs and the brain (Moisiadis and Matthews 2014a; Moisiadis and Matthews 2014b)
Since the obtained values for ATP- and ADP–hydrolysis indicated the presence of NTPDase1/CD39, while AMP-hydrolysing activity was indicative of e5ʹNT/CD73 expression, by use of real-time PCR (RT-PCR) and western blotting we analyzed relative abundance of mRNA and protein, for both ectonucleotidases in the rat fetal brain
Two protein bands at ~91 and 117 kDa were visible on immunoblots probed with anti-CD39 antibody (Fig. 3e), possibly indicating the presence of two glycoform, which combined abundance was determined by densitometric analysis

Summary

Introduction

Glucocorticoids (GCs - cortisol in humans, corticosterone in rodents) play a crucial role in a proper and timely completion of organogenesis during fetal development in the maturation of lungs and the brain (Moisiadis and Matthews 2014a; Moisiadis and Matthews 2014b). It is important to note that not just insufficient, and excessive prenatal exposure to GCs may have detrimental effects on brain development and functions (Davis et al 2013; Fukumoto et al 2009; Matthews 2000). It was shown that antenatal DEX treatment and excessive GC exposure have long-term neurodevelopmental consequences, which may be sex-specific both in human (Davis and Pfaff 2014; Wallensteen et al 2016) and in animal offspring (Caetano et al 2017; Matthews 2000). Prenatal GC treatment largely reduces risks of premature delivery, it increases the risk of neurodevelopmental complications and consequent adverse behavioral effects, such as hyperactivity (French et al 2004), and affective problems (Davis et al 2013) in children

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