Proteomics applied to pediatric medicine: opportunities and challenges.

INTRODUCTION: Care in pediatrics often refers to treatments directed to adults. However, childhood is a specific life period, with molecular pathways connected to development and thereby it requires distinctive considerations and special treatments under disease. Proteomics can help to elucidate the molecular mechanisms underlying the human development and disease onset in pediatric age and this review is devoted to underline the results recently obtained in the field. AREAS COVERED: The contribution of proteomics to the characterization of physiological modifications occurring during human development is presented. The proteomic studies carried out to elucidate the molecular mechanisms underlying different pediatric pathologies and to discover new markers for early diagnosis and prognosis of disease, comprising genetic and systemic pathologies, sepsis and pediatric oncology are thereafter reported. The investigations concerning milk composition in human and farm mammals are also presented. Finally, the chances offered by the integration of different -omic platforms are discussed. Expert commentary: The growing utilization of holistic technologies such as proteomics, metabolomics and microbiomics will allow, in the near future, to define at the molecular level the complexity of human development and related diseases, with great benefit for future generations.

Photoperiod Regulates vgf-Derived Peptide Processing in Siberian Hamsters.

VGF mRNA is induced in specific hypothalamic areas of the Siberian hamster upon exposure to short photoperiods, which is associated with a seasonal decrease in appetite and weight loss. Processing of VGF generates multiple bioactive peptides, so the objective of this study was to determine the profile of the VGF-derived peptides in the brain, pituitary and plasma from Siberian hamsters, and to establish whether differential processing might occur in the short day lean state versus long day fat. Antisera against short sequences at the C- or N- termini of proVGF, as well as against NERP-1, TPGH and TLQP peptides, were used for analyses of tissues, and both immunohistochemistry and enzyme linked immunosorbent assay (ELISA) coupled with high-performance liquid (HPLC) or gel chromatography were carried out. VGF peptide immunoreactivity was found within cortex cholinergic perikarya, in multiple hypothalamic nuclei, including those containing vasopressin, and in pituitary gonadotrophs. ELISA revealed that exposure to short day photoperiod led to a down-regulation of VGF immunoreactivity in the cortex, and a less pronounced decrease in the hypothalamus and pituitary, while the plasma VGF levels were not affected by the photoperiod. HPLC and gel chromatography both confirmed the presence of multiple VGF-derived peptides in these tissues, while gel chromatography showed the presence of the VGF precursor in all tissues tested except for the cortex. These observations are consistent with the view that VGF-derived peptides have pleiotropic actions related to changing photoperiod, possibly by regulating cholinergic systems in the cortex, vasopressin hypothalamic pathways, and the reproductive axis.