Evidence supporting a role for SMAD2/3 in bovine early embryonic development: potential implications for embryotropic actions of follistatin.
The TGF-beta-SMAD signaling pathway is involved in regulation of various aspects of female reproduction. However, the intrinsic functional role of SMADs in early embryogenesis remains poorly understood. Previously, we demonstrated that treatment with follistatin, an activin (TGF-beta superfamily ligand)-binding protein, is beneficial for bovine early embryogenesis and specific embryotropic actions of follistatin are dependent on SMAD4. Because SMAD4 is a common SMAD that can bind both SMAD2/3 and SMAD1/5, the objective of this study was to further determine the intrinsic role of SMAD2/3 in the control of early embryogenesis and delineate if embryotropic actions of follistatin in early embryos are SMAD2/3 dependent. By using a combination of pharmacological and small interfering RNA-mediated inhibition of SMAD2/3 signaling in the presence or absence of follistatin treatment, our results indicate that SMAD2 and SMAD3 are both required for bovine early embryonic development and stimulatory actions of follistatin on 8- to 16-cell and that blastocyst rates, but not early cleavage, are muted when SMAD2/3 signaling is inhibited. SMAD2 deficiency also results in reduced expression of the bovine trophectoderm cell-specific gene CTGF. In conclusion, the present work provides evidence supporting a functional role of SMAD2/3 in bovine early embryogenesis and that specific stimulatory actions of follistatin are not observed in the absence of SMAD2/3 signaling.
Laboratory of Mammalian Reproductive Biology and Genomics, Michigan State University, East Lansing, Michigan Department of Animal Science, Michigan State University, East Lansing, Michigan.
Kun
K
Zhang
Laboratory of Mammalian Reproductive Biology and Genomics, Michigan State University, East Lansing, Michigan Department of Animal Science, Michigan State University, East Lansing, Michigan.
Sandeep K
SK
Rajput
Laboratory of Mammalian Reproductive Biology and Genomics, Michigan State University, East Lansing, Michigan Department of Animal Science, Michigan State University, East Lansing, Michigan Department of Biology Education, College of Education, Chonnam National University, Gwangju, Korea.
Kyung-Bon
KB
Lee
Laboratory of Mammalian Reproductive Biology and Genomics, Michigan State University, East Lansing, Michigan Department of Animal Science, Michigan State University, East Lansing, Michigan Shuozhou Vocational and Technical College, Shuozhou, Shanxi, China.
Dongliang
D
Wang
Laboratory of Mammalian Reproductive Biology and Genomics, Michigan State University, East Lansing, Michigan Department of Animal Science, Michigan State University, East Lansing, Michigan.
Juncheng
J
Huang
Laboratory of Mammalian Reproductive Biology and Genomics, Michigan State University, East Lansing, Michigan Department of Animal Science, Michigan State University, East Lansing, Michigan.
Joseph K
JK
Folger
Department of Animal Science, Michigan State University, East Lansing, Michigan Developmental Epigenetics Laboratory, Michigan State University, East Lansing, Michigan.
Jason G
JG
Knott
Shuozhou Vocational and Technical College, Shuozhou, Shanxi, China.
Jiuzhen
J
Zhang
Laboratory of Mammalian Reproductive Biology and Genomics, Michigan State University, East Lansing, Michigan Department of Animal Science, Michigan State University, East Lansing, Michigan Department of Physiology, Michigan State University, East Lansing, Michigan smithge7@msu.edu.
George W
GW
Smith
D000818:Animals; D002417:Cattle; D055513:Connective Tissue Growth Factor / Q000235:genetics; D046149:Embryo Culture Techniques; D047108:Embryonic Development / Q000187:drug effects* / Q000235:genetics*; D005260:Female; D005307:Fertilization in Vitro; D038681:Follistatin / Q000494:pharmacology*; D011247:Pregnancy; D034741:RNA, Small Interfering / Q000235:genetics; D015398:Signal Transduction / Q000187:drug effects; D051899:Smad2 Protein / Q000235:genetics*; D051900:Smad3 Protein / Q000235:genetics*; D016212:Transforming Growth Factor beta / Q000378:metabolism
D038681:Follistatin; D034741:RNA, Small Interfering; D051899:Smad2 Protein; D051900:Smad3 Protein; D016212:Transforming Growth Factor beta; D055513:Connective Tissue Growth Factor
SMAD2/3; TGF-beta; cattle; embryo; follistatin; oocyte