title: Milk-borne lactocrine-acting factors affect gene expression patterns in the developing neonatal porcine uterus.
abstract: Lactocrine communication of milk-borne bioactive factors (MbFs) from mother to offspring through nursing can affect neonatal development with lasting consequences. Relaxin (RLX), a lactocrine-active peptide found in porcine colostrum, stimulates estrogen receptor-α (ESR1) expression required for uterine development shortly after birth (postnatal day=PND 0). Whether other MbFs or cooperative lactocrine mechanisms affect the neonatal uterine developmental program is unknown. To determine the effects of age, nursing, and exogenous RLX on gene expression associated with uterine development, gilts (n=4-5/group) were assigned to nurse ad libitum or to receive milk replacer, with or without exogenous RLX (20 μg/kg BW i.m./6 h for 48 h), from birth to PND 2 when uteri were collected. Body weight and uterine weight increased (P<0.05) similarly from birth to PND 2 in all gilts. However, colostrum consumption was required for normal uterine ESR1, vascular endothelial growth factor (VEGFA), matrix metalloproteinase 9 (MMP9), and RLX receptor (RXFP1) protein and/or transcript expression on PND 2. Uterine ESR1, VEGFA, and MMP9 protein levels were below (P<0.01) the assay sensitivity in replacer-fed gilts. Supplemental RLX increased (P<0.05) uterine ESR1 protein and mRNA in nursed gilts, as well as VEGFA protein in nursed and VEGFA mRNA in both nursed and replacer-fed gilts. RLX treatment did not affect uterine MMP9 mRNA levels. When compared with replacer-fed gilts on PND 2, uterine RXFP1 mRNA was reduced (P<0.05) in nursed gilts and in RLX-supplemented replacer-fed gilts. These results constitute the first evidence that establishment of the neonatal porcine uterine developmental program requires maternal lactocrine support.
authors.affiliation: Department of Animal Sciences, Rutgers University, 84 Lipman Drive, New Brunswick, New Jersey 08901, USA.
authors.forename: Joseph C
authors.initials: JC
authors.lastname: Chen
authors.forename: Amy-Lynn
authors.initials: AL
authors.lastname: Frankshun
authors.forename: Anne A
authors.initials: AA
authors.lastname: Wiley
authors.forename: Dori J
authors.initials: DJ
authors.lastname: Miller
authors.forename: Kristene A
authors.initials: KA
authors.lastname: Welch
authors.forename: Teh-Yuan
authors.initials: TY
authors.lastname: Ho
authors.forename: Frank F
authors.initials: FF
authors.lastname: Bartol
authors.forename: Carol A
authors.initials: CA
authors.lastname: Bagnell
mesh_terms: D000367:Age Factors; D000704:Analysis of Variance; D000818:Animals; D000831:Animals, Newborn; D015153:Blotting, Western; D001835:Body Weight; D047628:Estrogen Receptor alpha / Q000235:genetics / Q000378:metabolism; D005260:Female; D018507:Gene Expression Regulation, Developmental; D007774:Lactation; D016014:Linear Models; D020778:Matrix Metalloproteinase 2 / Q000235:genetics / Q000378:metabolism; D020780:Matrix Metalloproteinase 9 / Q000235:genetics / Q000378:metabolism; D008894:Milk Proteins / Q000378:metabolism*; D041941:Milk Substitutes; D009929:Organ Size; D016133:Polymerase Chain Reaction; D012333:RNA, Messenger / Q000378:metabolism; D043562:Receptors, G-Protein-Coupled / Q000235:genetics / Q000378:metabolism; D012065:Relaxin / Q000008:administration & dosage / Q000378:metabolism*; D015398:Signal Transduction; D013552:Swine; D014599:Uterus / Q000254:growth & development / Q000378:metabolism*; D042461:Vascular Endothelial Growth Factor A / Q000235:genetics / Q000378:metabolism
chemical_list: D047628:Estrogen Receptor alpha; D008894:Milk Proteins; D012333:RNA, Messenger; D043562:Receptors, G-Protein-Coupled; D042461:Vascular Endothelial Growth Factor A; D012065:Relaxin; D020778:Matrix Metalloproteinase 2; D020780:Matrix Metalloproteinase 9