title: Rapid label-free identification of estrogen-induced differential protein expression in vivo from mouse brain and uterine tissue.
abstract: Protein abundance profiling from tissue using liquid chromatography-tandem mass spectrometry-based "shotgun" proteomics and label-free relative quantitation was evaluated for the investigation of estrogen-regulated protein expression in the mouse brain and uterus. Sample preparation involved a 30-min protein extraction in 8 M aqueous urea solution, followed by disulfide reduction, thiol alkylation, and trypsin digestion of the extracted proteins, and was performed on 3-4 mg of tissue to evaluate the suitability of this methodology to expedite the survey of cellular pathways that are affected in vivo by an experimental therapeutic intervention in an animal model. The label-free proteomic approach (spectral counting) was suitable to identify even subtle changes in cortical protein levels and revealed significant estrogen-induced upregulation of ATP synthase (both alpha- and beta-isoforms), aspartate aminotransferase 2, and mitochondrial malate dehydrogenase without any prior subcellular fractionation of the tissue or the use of multidimensional chromatographic separation. The methodology was also suitable to observe various up- and downregulated proteins in the uterine tissue of ovariectomized mice upon treatment with 17beta-estradiol. In addition to confirming a very significant decrease in the abundance of glutathione S-transferase recognized as a marker of estrogen's impact, our studies have also revealed potential new protein markers such as desmin and lumican that are critical components of cytoskeletal arrangement and, hence, regulation of their abundance could contribute to major morphological changes in the uterus occurring upon estrogenic stimulation.
authors: Department of Molecular Biology and Immunology, University of North Texas Health Science Center, Fort Worth, 76107, USA. lprokai@hsc.unt.edu
authors: Laszlo
authors: L
authors: Prokai
authors: Stanley M
authors: SM
authors: Stevens
authors: Navin
authors: N
authors: Rauniyar
authors: Vien
authors: V
authors: Nguyen
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D001921:Brain / Q000187:drug effects / Q000378:metabolism*; D001923:Brain Chemistry; D002853:Chromatography, Liquid / Q000379:methods; D004958:Estradiol / Q000494:pharmacology; D004967:Estrogens / Q000378:metabolism*; D005260:Female; D051379:Mice; D008969:Molecular Sequence Data; D014176:Protein Biosynthesis; D020543:Proteome / Q000032:analysis / Q000096:biosynthesis*; D040901:Proteomics / Q000379:methods*; D015203:Reproducibility of Results; D053719:Tandem Mass Spectrometry / Q000379:methods; D014599:Uterus / Q000737:chemistry / Q000187:drug effects / Q000378:metabolism*
chemical_list: D004967:Estrogens; D020543:Proteome; D004958:Estradiol