Int. J. Devl Neuroscience 34 (2014) 24–32 Contents lists available at ScienceDirect International Journal of Developmental Neuroscience j ourna l ho me pa g e: www.elsevier.com/locate/ijdevneu Maternal micronutrient imbalance alters gene expression of BDNF, NGF, TrkB and CREB in the offspring brain at an adult age Pratiksha Sable, Anvita Kale, Asmita Joshi, Sadhana Joshi ∗ Department of Nutritional Medicine, Interactive Research School for Health Affairs, Bharati Vidyapeeth Deemed University, Pune Satara Road, Pune 411043, India a r t i c l e i n f o Article history: Received 6 December 2013 Received in revised form 7 January 2014 Accepted 13 January 2014 Keywords: BDNF NGF TrkB CREB Micronutrient imbalance Cognition a b s t r a c t Micronutrients like folate, vitamin B 12 , and fatty acids which are interlinked in the one carbon cycle play a vital role in mediating epigenetic processes leading to an increased risk for neurodevelopmental disorders in the offspring. Our earlier study demonstrates that a micronutrient imbalanced diet adversely affects docosahexaenoic acid (DHA) and protein levels of neurotrophins like brain-derived neurotrophic factor (BDNF) and nerve growth factor (NGF) in the brain and cognition in the offspring by 3 months of age. In this study we attempt to analyze if these effects are a consequence of a change in gene expression of these molecules. Further, we also examined the effect of either a postnatal control diet or a prenatal omega-3 fatty acid supplementation on gene expression in the cortex of the offspring. Pregnant rats were divided into control and five treatment groups at two levels of folic acid (normal and excess folate) in the presence and absence of vitamin B 12 . Omega-3 fatty acid (eicosapentaenoic acid – EPA + DHA) supplementation was given to vitamin B 12 deficient groups. Following delivery, 8 dams from each group were shifted to control diet and remaining continued on the same treatment diet. Our results demonstrate that the imbalanced diet caused a marked reduction in the mRNA levels of BDNF, NGF, TrkB, and cAMP response element-binding protein (CREB). Prenatal omega-3 fatty acid supplementation to the maternal imbalanced diet was able to normalize the mRNA levels of all the above genes. This study demonstrates that a maternal diet imbalanced in micronutrients (folic acid, vitamin B 12 ) influences gene expression of neurotrophins and their signalling molecules and thereby adversely affects the brain of the offspring. © 2014 ISDN. Published by Elsevier Ltd. All rights reserved. 1. Introduction The field of “developmental origins of health and disease” (DOHaD) has developed tremendously over the years and increas- ing knowledge suggests that maternal diet can have long-lasting effects on the offspring health (Vanhees et al., 2014). Micronutri- ents like folic acid and vitamin B 12 are part of the one carbon cycle and are vital for the generation of methyl groups which affect DNA and histone methylation thereby regulating gene expression in the offspring (Dominguez-Salas et al., 2012). Studies by us and others have shown that micronutrients like folate and vitamin B 12 are interlinked and influence levels of important long chain Abbreviations: BDNF, brain derived neurotrophic factor; CREB, cAMP response element-binding protein; DAG, diacylglycerol; DHA, docosahexaenoic acid; GAPDH, glyceraldehyde 3-phosphate dehydrogenase; IP3, inositol 1,4,5-trisphosphate; MAPK, mitogen activated protein kinases; NGF, nerve growth factor; PI3K, phos- phatidylinositol 3-kinase pathway; PLC, phospholipase. ∗ Corresponding author. Tel.: +91 020 24366929/020 24366931; fax: +91 020 24366929. E-mail address: srjoshi62@gmail.com (S. Joshi). polyunsaturated fatty acids (LCPUFAs) like docosahexaenoic acid (DHA) (Van Wijk et al., 2012; Kale et al., 2010). DHA, an important omega-3 LCPUFA in the central nervous system, is located in the synaptic end sites and is required for increasing the fluidity of cell membranes and maturation of synapses (Willatts and Forsyth, 2000). Reports also suggest that DHA supplementation improves behaviour and cognition in chil- dren (Milte et al., 2012; Richardson et al., 2012). Brain development and cognition are also known to be influenced by neurotrophins which play a role in development, growth, and differentiation of the nervous system (Stoleru et al., 2013). Studies indicate that neu- rotrophins can positively be influenced by fatty acids like DHA (Wu et al., 2008; Sharma et al., 2012). Various neurotrophins are involved in learning, memory and behaviour and their alterations have been linked to the onset of psychiatric disorders (Chao et al., 2006). These neurotrophins are present in abundance in the brain and mediate their function through their membrane tyrosine kinase receptors (Patapoutian and Reichardt, 2001). Further, binding of brain derived neu- rotrophic factor (BDNF) to its receptor leads to phosphorylation of tyrosine residues thereby activating the transcription factor cAMP response element-binding protein (CREB) (Cunha et al., 2010). A 0736-5748/$36.00 © 2014 ISDN. Published by Elsevier Ltd. All rights reserved. http://dx.doi.org/10.1016/j.ijdevneu.2014.01.003