Proteome analysis for the identification of in vivo estrogen-regulated proteins in bone.
Estrogen deficiency results in a reduced bone mass, which can be prevented by treatment with estrogens. This study used a proteomic approach for the first time to obtain a global perspective of estrogens' effects on whole-bone proteins. Bone proteome profiles were examined in three groups of mice: (1) sham-operated with normal ovarian functions, (2) ovariectomised and (3) ovariectomised with estrogen replacement therapy. Bone proteins extracted from the humerus were separated by 2-DE and visualised by CBB colloidal staining. Spot detection and quantification was done by image analysis. Differentially expressed proteins were identified by MS and database search, using peptide mass fingerprint and peptide sequence analysis. Differential expression analysis in the three experimental groups showed significant changes for 14 proteins. These included proteins related to bone metabolism, cytoskeleton components and energy metabolic pathways. Our data suggest that some proteins related to cytoskeleton and to energy pathways, such as tropomyosins, aconitase 2 and enolase beta, might be new molecular targets responsive to the effects of estrogen. Differentially expressed proteins identified in this model may offer a useful starting point for elucidating novel aspects of the pleiotropic effects of estrogens on bone.
Pastorelli
Roberta
R
Department of Environmental Health Sciences, Istituto di Ricerche Farmacologiche Mario Negri, Via Eritrea 62, 20157 Milan, Italy. rpastorelli@marionegri.it
Carpi
Donatella
D
Airoldi
Luisa
L
Chiabrando
Chiara
C
Bagnati
Renzo
R
Fanelli
Roberto
R
Moverare
Sofia
S
Ohlsson
Claes
C
D000818:Animals; D001842:Bone and Bones / Q000187:drug effects* / Q000378:metabolism*; D002853:Chromatography, Liquid; D015180:Electrophoresis, Gel, Two-Dimensional / Q000379:methods; D004967:Estrogens / Q000494:pharmacology*; D005260:Female; D006811:Humerus / Q000187:drug effects / Q000378:metabolism; D013058:Mass Spectrometry; D051379:Mice; D010052:Ovariectomy; D011506:Proteins / Q000378:metabolism*; D020543:Proteome / Q000032:analysis*; D015203:Reproducibility of Results; D019032:Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization
D004967:Estrogens; D011506:Proteins; D020543:Proteome