Nursing during the first two days of life is essential for the expression of proteins important for growth and remodeling of the neonatal porcine cervix.
The neonatal porcine cervix is sensitive to hormones, including relaxin (RLX), from birth. Whether nursing is required to establish the cervical developmental program or to determine cervical developmental trajectory is unknown. The objective of study 1 was to determine effects of age and nursing on expression of molecular markers and mediators of porcine cervical growth and remodeling from birth to postnatal day (PND) 2 and to document effects of RLX treatment during this period on expression of targeted gene products in nursed vs. replacer-fed gilts. Study 2 was conducted to determine effects of age at first nursing and duration of nursing from birth on expression of targeted transcripts or proteins at PND 14. Nursing supported cervical estrogen receptor-α, vascular endothelial growth factor, matrix metalloproteinase (MMP)9, and antiapoptotic B-cell lymphoma-2 protein expression on PND 2. These proteins were undetectable in replacer-fed gilts. Returning replacer-fed gilts to nursing after PND 2 did not restore cervical expression of these proteins by PND 14. RLX increased (P < 0.05) cervical estrogen receptor-α, vascular endothelial growth factor, and B-cell lymphoma-2 protein in nursed gilts, MMP2 protein in nursed and replacer-fed gilts, and decreased (P < 0.05) pro-MMP9 protein in nursed gilts, and RXFP1 mRNA levels in nursed and replacer-fed gilts at PND 2. Replacer feeding for 2 wk from birth increased (P < 0.05) RXFP1 mRNA levels on PND 14. Results support the lactocrine hypothesis for maternal programming of neonatal tissues. Nursing from birth is required to establish the neonatal cervical developmental program and to maintain cervical developmental trajectory to PND 14.
Department of Animal Sciences, Endocrinology and Animal Biosciences Program, Rutgers, The State University of New Jersey, 84 Lipman Drive, New Brunswick, New Jersey 08901, USA.
Amy-Lynn
AL
Frankshun
Joseph
J
Chen
Lauren A
LA
Barron
Teh-Yuan
TY
Ho
Dori J
DJ
Miller
Kathleen M
KM
Rahman
Frank F
FF
Bartol
Carol A
CA
Bagnell
D000818:Animals; D000831:Animals, Newborn; D002584:Cervix Uteri / Q000187:drug effects* / Q000254:growth & development* / Q000378:metabolism; D047628:Estrogen Receptor alpha / Q000378:metabolism; D005260:Female; D018507:Gene Expression Regulation, Developmental; D015151:Immunoblotting; D020778:Matrix Metalloproteinase 2 / Q000378:metabolism; D020780:Matrix Metalloproteinase 9 / Q000378:metabolism; D016133:Polymerase Chain Reaction; D012065:Relaxin / Q000494:pharmacology; D013552:Swine; D042461:Vascular Endothelial Growth Factor A / Q000378:metabolism
D047628:Estrogen Receptor alpha; D042461:Vascular Endothelial Growth Factor A; D012065:Relaxin; D020778:Matrix Metalloproteinase 2; D020780:Matrix Metalloproteinase 9