Prokineticins (endocrine gland-derived vascular endothelial growth factor and BV8) in the bovine ovary: expression and role as mitogens and survival factors for corpus luteum-derived endothelial cells.
A highly vascular endocrine gland, the corpus luteum (CL) is an excellent model for the study of angiogenic factors. Prokineticins (PK-1 and -2), also termed endocrine-gland-derived vascular endothelial growth factor (VEGF) and BV8 are newly identified proteins described as selective angiogenic mitogens. We previously identified PK binding sites, two closely homologous G protein-coupled receptors (PK-R1 and PK-R2) in human and bovine ovarian cells, but their function remained unknown. In this study we examined the presence and effects of PK in CL-derived endothelial and steroidogenic cell types (LEC and LSC, respectively). PK-1 mRNA was identified in CL and follicles by real-time PCR, using primers specific for the bovine PK-1 sequence (retrieved from Bos taurus whole genome shotgun database). PK were potent angiogenic mitogens for LEC; they enhanced cell proliferation, elevated [3H]thymidine incorporation, MAPK activation, and c-jun/fos mRNA expression. The effects of PK proteins on cell survival were examined by nuclear morphology (4',6-diamidino-2-phenylindole dihydrochloride staining), measurement of DNA fragmentation (terminal dUTP nucleotide end labeling assay), and caspase-3 cleavage. Results obtained by these techniques demonstrated that PK protected LEC from serum starvation-induced apoptosis. Stress conditions such as serum withdrawal, TNF-alpha, and hypoxia markedly increased PK-R2 expression, whereas mRNA levels of PK-R1 remained unchanged. These suggest that the antiapoptotic effect of PK-1 on LEC may be mediated via PK-R2. PK-1 increased VEGF mRNA expression by LSC, implying that it could also indirectly, via VEGF, affect luteal angiogenesis. Together, these findings suggest an important role for PK-1 in luteal function by acting as a mitogen and survival factor in LEC.
Kisliouk
Tatiana
T
Department of Animal Sciences, Faculty of Agricultural, Food and Environmental Quality Sciences, The Hebrew University of Jerusalem, Rehovot 76100, Israel.
Podlovni
Helena
H
Spanel-Borowski
Katharina
K
Ovadia
Oded
O
Zhou
Qun-Yong
QY
Meidan
Rina
R
D000595:Amino Acid Sequence; D000818:Animals; D017209:Apoptosis / Q000187:drug effects / Q000502:physiology; D001483:Base Sequence; D002417:Cattle; D002455:Cell Division / Q000502:physiology; D002470:Cell Survival / Q000502:physiology; D002478:Cells, Cultured; D003338:Corpus Luteum / Q000166:cytology* / Q000502:physiology*; D016895:Culture Media, Serum-Free / Q000494:pharmacology; D005260:Female; D006107:Granulosa Cells / Q000166:cytology / Q000502:physiology; D020935:MAP Kinase Signaling System / Q000502:physiology; D008934:Mitogens / Q000235:genetics / Q000378:metabolism; D008969:Molecular Sequence Data; D010455:Peptides / Q000235:genetics* / Q000378:metabolism; D016760:Proto-Oncogene Proteins c-fos / Q000235:genetics; D016755:Proto-Oncogene Proteins c-jun / Q000235:genetics; D012333:RNA, Messenger / Q000378:metabolism; D020794:Receptor Protein-Tyrosine Kinases / Q000235:genetics; D013799:Theca Cells / Q000166:cytology / Q000502:physiology; D013936:Thymidine / Q000493:pharmacokinetics; D014316:Tritium; D042461:Vascular Endothelial Growth Factor A / Q000235:genetics; D042662:Vascular Endothelial Growth Factor, Endocrine-Gland-Derived / Q000235:genetics* / Q000378:metabolism
D016895:Culture Media, Serum-Free; D008934:Mitogens; D010455:Peptides; D016760:Proto-Oncogene Proteins c-fos; D016755:Proto-Oncogene Proteins c-jun; D012333:RNA, Messenger; D042461:Vascular Endothelial Growth Factor A; D042662:Vascular Endothelial Growth Factor, Endocrine-Gland-Derived; D014316:Tritium; D020794:Receptor Protein-Tyrosine Kinases; D013936:Thymidine