Blood cell transcriptomic-based early biomarkers of adverse programming effects of gestational calorie restriction and their reversibility by leptin supplementation

The challenge of preventing major chronic diseases requires reliable, early biomarkers. Gestational mild undernutrition in rats is enough to program the offspring to develop later pathologies; the intake of leptin, a breastmilk component, during lactation may reverse these programming effects. We used these models to identify, in peripheral blood mononuclear cells (PBMCs), transcriptomic-based early biomarkers of programmed susceptibility to later disorders, and explored their response to neonatal leptin intake. Microarray analysis was performed in PBMCs from the offspring of control and 20% gestational calorie-restricted dams (CR), and CR-rats supplemented with physiological doses of leptin throughout lactation. Notably, leptin supplementation normalised 218 of the 224 mRNA-levels identified in PBMCs associated to undernutrition during pregnancy. These markers may be useful for early identification and subsequent monitoring of individuals who are at risk of later diseases and would specifically benefit from the intake of appropriate amounts of leptin during lactation.


Gls
Glutaminase GLS It catalyzes the hydrolysis of glutamine to glutamate and ammonia. This protein is primarily expressed in the brain and kidney and plays an essential role in generating energy for metabolism, synthesizing the brain neurotransmitter glutamate and maintaining acid-base balance in the kidney 5 .

Lrp11
Low density lipoprotein receptor-related protein 11

LRP11
Member of the LDL receptor family, a class of structurally closely related cell surface receptors fulfilling diverse functions in different tissues, which has been recently positioned as one of the key players in Alzheimer disease research 6 .

Paox
Polyamine oxidase (exo-N4-amino) PAO Flavoenzyme that catalyzes the oxidation of N(1)-acetylspermine to spermidine and hence is involved in the polyamine backconversion, thus playing an important role in the regulation of polyamine intracellular concentration. However, PAO activity results in production of ammonia, the corresponding amino aldehydes, and hydrogen peroxide. Malondialdehyde (MDA) and acrolein, potentially toxic agents, which induce oxidative stress in mammalian cells, are spontaneously formed from aminoaldehydes. Thus, resulting products of PAO activity have the potential to produce disease states. Increased PAO activity has been found in type 1 diabetic children, associated to increased blood HbA(1C) and MDA levels, demonstrating that increased plasma PAO activity may participate in these circumstances 7 . Activation of PAO has also been associated to macrophage apoptosis due to hydrogen peroxide release and mitochondrial membrane depolarization, contributing to deficiencies in host defence in diseases such as H. pylori infection 8 .

RNF10
The protein contains a ring finger motif, which is known to be involved in protein-protein interactions. The specific function of this protein has not yet been determined, but recent findings pinpoint its critical role in myelin formation and neuronal differentiation 9,10 . Selenbp1 Selenium binding protein 1 SELENBP1 Member of selenoproteins family. These proteins bind selenium covalently and mediate the intracellular transport of selenium 11 . A deficiency of dietary selenium is associated with an increased incidence of epithelial cancers including lung, liver, colorectal, and prostate cancer 12 . Selenium exerts its anticarcinogenic effects mainly through selenoproteins, and expression of SELENBP1 has been found to be reduced markedly in multiple epithelial cancers compared with their corresponding normal tissues. The exact function of SELENBP1 is not known, although, a possible link to malignancies associated with selenium deficiencies has been suggested 13,14 .

SLC7A5, LAT1
It is involved in the sodium-independent cellular transport of amino acids with large neutral amino acid side chains 15 . Increased expression levels of Slc7a5 gene were positively correlated with increased biological aggressiveness and higher mortality in a range of human cancers 16 . Expression levels of this gene may be nutritionally modulated, since decreased expression levels were described in brain tissues of pigs fed low dietary protein 17 .

Tß4
The major actin-sequestering protein in all eukaryotic cells and a potent regulator of actin polymerization in mammals 18 . Numerous studies have identified a range of functions and activities for Tß4 important for wound healing and repair and tissue regeneration 18 . Tß4 also appears to be involved in the regulation of the development and regeneration of the nervous system, as a novel neurotrophic signal 19 . It is highly expressed in most neural cell types of the developing brain, and has also been found to be abundant in the injured/regenerating axons, suggesting that the upregulation of Tß4 is related to the axonal sprouting and neuronal regeneration. On the other hand, up-regulation of Tmsb4x gene has been discovered in a wide variety of human carcinomas and has been proposed as a key event in the acquisition of growth advantages as well as invasive phenotypes in human colorectal carcinomas 20 . Ubash3b Ubiquitin associated and SH3 domain containing, B UBASH3B, STS-1 The protein exhibits tyrosine phosphatase activity toward several substrates. This protein contains an ubiquitin associated domain at the N-terminus. Proteins containing ubiquitin-binding domains (UBDs) interact with ubiquitinated targets and regulate diverse biological processes, including endocytosis, signal transduction, transcription and DNA repair 21 . Overexpression of this gene has been identified in aggressive cancers like triple-negative breast cancer, and promotes invasion and metastasis 22 .