Prostaglandin F2α-induced luteolysis involves activation of Signal transducer and activator of transcription 3 and inhibition of AKT signaling in cattle.
Prostaglandin F2α (PGF) induces the precipitous loss of steroidogenic capabilities and cellular death in the corpus luteum of many species, yet the molecular mechanisms underlying this event are not completely understood. Signal transducer and activator of transcription 3 (STAT3) was activated in granulosa cells during follicle atresia, whereas AKT is immediately down-regulated in the corpus luteum after PGF treatment in cattle; however, their involvement in both functional and morphological luteolysis in monovular species still need to be determined. Blood samples and corpus lutea were collected from cows before (0) and 2, 12, 24, and 48 hr after PGF treatment on Day 10 of the estrous cycle (4-5 cows per time point). Serum progesterone concentrations decreased by threefold (p < 0.05) within 2 hr, confirming functional luteolysis. The mRNA abundance of the pro-apoptotic gene BAX increased 12-48 hr post-PGF treatment (p < 0.05), while morphological luteolysis was observed 24 and 48 hr after PGF treatment, based on the loss of plasma membrane integrity, reduction of cytoplasmic volume, and pyknotic nuclei. Phosphorylated STAT3 increased, peaking at 12 hr, and remained elevated until 48 hr after PGF treatment. SOCS3 transcript abundance also increased (p < 0.05) starting at 2 hr post-PGF treatment. In contrast, AKT phosphorylation decreased by 12 hr after treatment. Thus, activation of STAT3 and inactivation of AKT signaling are involved in structural regression of the corpus luteum.
Laboratory of Biotechnology and Animal Reproduction-BioRep, Federal University of Santa Maria, Maria Santa, Rio Grande do Sul, Brazil.|Department of Animal Science, McGill University, Sainte Anne de Bellevue, Quebec, Canada.
Monique T
MT
Rovani
Laboratory of Biotechnology and Animal Reproduction-BioRep, Federal University of Santa Maria, Maria Santa, Rio Grande do Sul, Brazil.|Department of Animal Science, McGill University, Sainte Anne de Bellevue, Quebec, Canada.
Gustavo F
GF
Ilha
Department of Animal Pathology, Federal University of Pelotas, Capão do Leão, Brazil.
Bernardo G
http://orcid.org/0000-0002-3715-2345
BG
Gasperin
Laboratory of Biotechnology and Animal Reproduction-BioRep, Federal University of Santa Maria, Maria Santa, Rio Grande do Sul, Brazil.
Jandui E
JE
Nóbrega
Department of Animal Science, McGill University, Sainte Anne de Bellevue, Quebec, Canada.
Dayananda
D
Siddappa
Laboratory of Biotechnology and Animal Reproduction-BioRep, Federal University of Santa Maria, Maria Santa, Rio Grande do Sul, Brazil.
Werner G
http://orcid.org/0000-0001-6467-8687
WG
Glanzner
Laboratory of Biotechnology and Animal Reproduction-BioRep, Federal University of Santa Maria, Maria Santa, Rio Grande do Sul, Brazil.
Alfredo Q
AQ
Antoniazzi
Department of Animal Science, McGill University, Sainte Anne de Bellevue, Quebec, Canada.
Vilceu
V
Bordignon
Department of Animal Science, McGill University, Sainte Anne de Bellevue, Quebec, Canada.
Raj
R
Duggavathi
Laboratory of Biotechnology and Animal Reproduction-BioRep, Federal University of Santa Maria, Maria Santa, Rio Grande do Sul, Brazil.
Paulo B D
PBD
Gonçalves
D000818:Animals; D002417:Cattle; D003338:Corpus Luteum / Q000378:metabolism*; D015237:Dinoprost / Q000494:pharmacology*; D005260:Female; D003341:Luteolysis / Q000378:metabolism*; D051057:Proto-Oncogene Proteins c-akt / Q000378:metabolism*; D050796:STAT3 Transcription Factor / Q000378:metabolism*; D015398:Signal Transduction / Q000187:drug effects*
D050796:STAT3 Transcription Factor; D015237:Dinoprost; D051057:Proto-Oncogene Proteins c-akt
apoptosis; corpus luteum; cow; pregnancy; progesterone