title: Uterine secretome and its modulation in rat (Rattus norvegicus).
abstract: The present study identifies uterine fluid (UF) proteins that display differential abundance during the embryo-permissive phase in nonconception and conception cycles in rats. UF samples were collected from nonpregnant rats in the proestrous (n=17) and metestrous (n=18) phases and also from pregnant (n=17) and pseudopregnant (n=17) rats on day 4 post coitus. UF protein profile in the metestrous phase was compared with that in the proestrous phase. Similarly, UF protein profile of the pregnant rats was compared with that of the pseudopregnant rats. Two-dimensional PAGE, followed by densitometric analysis of the paired protein spots, revealed differential abundance of 44 proteins in the metestrous phase, compared with that in the proestrous phase. Of these, 29 proteins were identified by matrix-assisted laser desorption/ionization time-of-flight or liquid chromatography-tandem mass spectrometry. Functional groups such as proteases, protease inhibitors, and oxidoreductases were enriched in differentially abundant proteins. Total protease activity in UF was found to be significantly (P<0.05; t-test) higher in the proestrous phase, compared with that in the metestrous phase. Furthermore, 41 UF proteins were found to be differentially abundant in pregnant rats, compared with pseudopregnant rats. Of these, 11 proteins could be identified. Immunoblotting analysis confirmed significantly higher (P<0.05; t-test) abundance of β-actin, Rho-specific guanine nucleotide dissociation inhibitor alpha (Rho-GDIα), and peroxiredoxin-2 and -6 in the metestrous phase, compared with that in the proestrous phase. Compared with pseudopregnant rats, pregnant rats had significantly higher (P<0.05; t-test) levels of UF β-actin and Rho-GDIα. Furthermore, these proteins could be detected in the culture supernatants of endometrial epithelial cell lines, thereby providing an evidence of their secretion from endometrial epithelial cells. Data obtained from the study expand our knowledge on the uterine milieu that favours embryo implantation.
authors: Primate Biology Division, National Institute for Research in Reproductive Health, Indian Council of Medical Research, JM Street, Parel, Mumbai 400012, India.
authors: Sumit
authors: S
authors: Bhutada
authors: R R
authors: RR
authors: Katkam
authors: Tarla
authors: T
authors: Nandedkar
authors: S M
authors: SM
authors: Metkari
authors: U K
authors: UK
authors: Chaudhari
authors: Sneha
authors: S
authors: Varghese
authors: S D
authors: SD
authors: Kholkute
authors: Geetanjali
authors: G
authors: Sachdeva
mesh_terms: D000199:Actins / Q000378:metabolism; D000818:Animals; D002460:Cell Line; D015180:Electrophoresis, Gel, Two-Dimensional; D010064:Embryo Implantation; D004717:Endometrium / Q000378:metabolism; D005260:Female; D006801:Humans; D008686:Metestrus / Q000502:physiology; D010447:Peptide Hydrolases / Q000378:metabolism; D054465:Peroxiredoxin VI / Q000378:metabolism; D011247:Pregnancy; D011270:Pregnancy, Animal / Q000502:physiology*; D011555:Pseudopregnancy / Q000378:metabolism; D051381:Rats; D014599:Uterus / Q000378:metabolism*; D062948:rho Guanine Nucleotide Dissociation Inhibitor alpha / Q000378:metabolism
chemical_list: D000199:Actins; D062948:rho Guanine Nucleotide Dissociation Inhibitor alpha; D054465:Peroxiredoxin VI; D010447:Peptide Hydrolases