Expression of DA11, a neuronal-injury-induced fatty acid binding protein, coincides with axon growth and neuronal differentiation during central nervous system development

Abstract

DA11 is the first fatty acid binding protein (FABP) for which gene expression has been shown to be upregulated following neuronal injury in the adult peripheral nervous system. To understand better the potential regulatory role(s) of this unique FABP in axonal growth and neuronal differentiation, we undertook a temporal and spatial study of DA11 gene expression in the developing rat central nervous system (CNS). Transient upregulation of DA11 mRNA and protein levels in CNS tissues were quantified by Northern blot hybridization and Western immunoblot analyses at different developmental ages. Homogenates of embryonic and neonatal cerebral cortex, cerebellum, brain stem, and hippocampal tissues contained 100-fold more DA11 mRNA and protein than corresponding adult tissues. Significant increase in DA11 mRNA was observed as early as embryonic day (E) 14 in cerebral cortex and cerebellum and E19 in brain stem and hippocampus. Postnatal levels of DA11 remained elevated through postnatal day (P) 10 in cerebral cortex, P14 in brain stem and hippocampus, and P20 in cerebellum. Localization of DA11-like immunoreactivity to specific CNS tissues, cell types, and intracellular compartments at P9 revealed a spatial pattern of neuronal expression different than that reported for other FABPs. DA11 protein was detected in the nucleus, cytoplasm, axons, and dendrites of differentiating neurons in cerebral cortex, hippocampus, cerebellum, brain stem, spinal cord, and olfactory bulb. The strong association of DA11 gene expression with development throughout the CNS suggests that this unique FABP plays an important role in axonal growth and neuronal differentiation in many different neuronal populations.

New insights into the structure and function of fatty acid-binding proteins

“…In mouse brain, H-FABP levels are detectable after fetal day 19 and increase until post-natal day 14, but become lower in the adult brain [221]. In contrast to H-FABP, the expression of B-FABP and E-FABP is dominant in the pre-natal and peri-natal mouse and rat brain [219,220]. E-FABP mRNA and protein are expressed at high levels during neurogenesis, neuronal migration and terminal differentiation of neurons [219,222].…”

“…The brain contains three different types of FABP: H-FABP [47], B-FABP [217,218] and E-FABP [20,219]. The genes for these brain FABP types show a spatiotemporally differential expression in developing and mature brain [219,220]. The expression of H-FABP becomes evident in rat brain after birth, with a gradual increase, and is confined to the grey matter, suggesting that its mRNA is neuron specific [220].…”

“…In contrast to H-FABP, the expression of B-FABP and E-FABP is dominant in the pre-natal and peri-natal mouse and rat brain [219,220]. E-FABP mRNA and protein are expressed at high levels during neurogenesis, neuronal migration and terminal differentiation of neurons [219,222]. Hormones and physiological changes have a particular effect on the expression of L-FABP [9,213,223].…”

Modulation of Cutaneous Fatty Acid-binding Protein mRNA Expression in Rat Adipose Tissues by Hereditary Obesity and Dietary Fats

“…However, its mRNA was later found to be expressed in various tissues including adipose tissue 5,8,9,[12][13][14][15][16][17][18][19][20][21][22][23] . Krieg et al 5) examined levels of C-FABP mRNA in mouse tissues, and found that the mRNA was most abundant in stratified epithelia of the epidermis and tongue.…”

Neuroprotective and Ameliorative Actions of Polyunsaturated Fatty Acids Against Neuronal Diseases: Implication of Fatty Acid–Binding Proteins (FABP) and G Protein–Coupled Receptor 40 (GPR40) in Adult Neurogenesis

“…1). Together with the uptake and delivery of fatty acids within the neurogenic niches, FABP are assigned to play crucial roles in the cell growth and differentiation (110,116,117) by regulating certain transcription factors. Targeted transcription factors are the members of the peroxisome proliferatoractivated receptor (PPAR) family, comprising of three isotypes -PPARα, PPARγ, and PPARδ/β (118,119), with PPARδ/β abundantly expressed in the CNS (120).…”