Changes in Porcine Corpus Luteum Proteome Associated with Development, Maintenance, Regression, and Rescue during Estrous Cycle and Early Pregnancy

Abstract

Corpus luteum (CL), a transitory gland, undergoes rapid growth in a limited time to produce progesterone (P4) followed by its regression. A complex molecular signaling is involved in controlling luteal P4 production. In the present study, 2D gel electrophoresis-based proteomics and in silico functional analysis were used to identify changes in key proteins and pathways in CL along the different stages of the estrous cycle as its development progresses from early (Day 3) to mid-luteal phase (Day 9), effective functioning (Day 12) followed by regression (Day 15) or, in the case of pregnancy, rescue of function (Day 15). A total of 273 proteins were identified by MALDI-MS/MS analysis that showed significant changes in abundances at different stages of CL development or regression and rescue. Functional annotation of differentially abundant proteins suggested enrichment of several important pathways and functions during CL development and function maintenance including cell survival, endocytosis, oxidative stress response, estradiol metabolism, and angiogenesis. On the other hand, differentially abundant proteins during CL regression were associated with decreased steroid synthesis and metabolism and increased apoptosis, necrosis, and infiltration of immune cells. Establishment of pregnancy rescues CL from regression by maintaining the expression of proteins that support steroidogenesis as pathways such as the super-pathway of cholesterol biosynthesis, RhoA signaling, and functions such as fatty acid metabolism and sterol transport were enriched in CL of pregnancy. In this study, some novel proteins were identified along CL development that advances our understanding of CL survival and steroidogenesis.

Identification of postnatal development dependent genes and proteins in porcine epididymis

“…It is well-known that the apoptotic and immune response processes exert vital roles in gonadal development and function maintenance during sexual maturity [ 47 , 48 ]. Here, the key down-regulated proteins kininogen-1 (KNG1), complement component C3 (C3), transferrin (TF), and serpin family B member 1 (SERPINB1) are implicated in apoptotic and immune response processes.…”

The effects of rumen protected methionine supplementation on the performance of primiparous dairy cows using the Presynch‐Ovsynch protocol

“…Furthermore, there was a positive correlation between the number of corpora lutea of pregnancy and P4 production (Ku'znicka et al, 2016). By preserving the expression of proteins that support steroidogenesis as pathways were enriched in CL of pregnancy, the establishment of pregnancy in the RPM diet prevents CL from regressing (Likszo et al, 2021). We suggest that elevated P4 levels could be due to the essential role of RPM in the P4 synthesis.…”

A matter of new life and cell death: programmed cell death in the mammalian ovary

“…They proposed a new model of RIPK3-dependent apoptosis which contributes to PGF2α-dependent luteolysis, but these data also imply that RIPK3 may switch to its canonical induction of necroptosis in some currently unknown conditions. Comparative proteomic data for several stages of CL development and regression identified necro(pto)sis among the most affected processes in the late luteal phase CL [ 293 ]. It is evident that the investigation of necroptosis in luteolysis is currently in its initial phase.…”