Angiogenin, an exceedingly potent mediator of new blood vessel formation, was isolated from growth medium conditioned by human colon cancer cells and sequenced by Strydom et al. (1985). NCBI Summary:
The protein encoded by this gene is an exceedingly potent mediator of new blood vessel formation. It hydrolyzes cellular tRNAs resulting in decreased protein synthesis and is similar to pancreatic ribonuclease. In addition, the mature peptide has antimicrobial activity against some bacteria and fungi, including S. pneumoniae and C. albicans. Alternative splicing results in two transcript variants encoding the same protein. This gene and the gene that encodes ribonuclease, RNase A family, 4 share promoters and 5' exons. Each gene splices to a unique downstream exon that contains its complete coding region. [provided by RefSeq, Aug 2014]
General function
Ligand, Hormone
Comment
Cellular localization
Secreted
Comment
Ovarian function
Steroid metabolism, Luteinization
Comment
Effects of angiogenin on granulosa and theca cell function in cattle. Dentis JL et al. (2016) Angiogenin is a member of the ribonuclease A superfamily of proteins that has been implicated in stimulating angiogenesis but whether angiogenin can directly affect ovarian granulosa or theca cell function is unknown. Therefore, the objective of these studies was to determine the effect of angiogenin on proliferation and steroidogenesis of bovine granulosa and theca cells. In experiments 1 and 2, granulosa cells from small (1 to 5 mm diameter) follicles and theca cells from large (8 to 22 mm diameter) follicles were cultured to evaluate the dose-response effect of recombinant human angiogenin on steroidogenesis. At 30 and 100 ng/ml, angiogenin inhibited (P0.10) granulosa cell estradiol production or theca cell progesterone production, and did not affect numbers of granulosa or theca cells. In experiments 3 and 4, granulosa and theca cells from both small and large follicles were cultured with 300 ng/ml of angiogenin to determine if size of follicle influenced responses to angiogenin. At 300 ng/ml, angiogenin increased large follicle granulosa cell proliferation but decreased small follicle granulosa cell progesterone and estradiol production and large follicle theca cell progesterone production. In experiments 5 and 6, angiogenin stimulated (P<0.05) proliferation and DNA synthesis in large follicle granulosa cells. In experiment 7, 300 ng/ml of angiogenin increased (P<0.05) CYP19A1 messenger RNA (mRNA) abundance in granulosa cells but did not affect CYP11A1 mRNA abundance in granulosa or theca cells and did not affect CYP17A1 mRNA abundance in theca cells. We conclude that angiogenin appears to target both granulosa and theca cells in cattle, but additional research is needed to further understand the mechanism of action of angiogenin in granulosa and theca cells, as well as its precise role in folliculogenesis.//////////////////
Expression regulated by
LH
Comment
Koga K, et al 2000 reported the presence of angiogenin in human follicular
fluid and the up-regulation of its production by human
chorionic gonadotropin and hypoxia.
They investigated the
presence of angiogenin, a potent inducer of angiogenesis, and the regulatory
mechanisms of its production in the human ovary. Follicular fluid (FF) and
granulosa cells (GCs) were collected from women undergoing in vitro
fertilization and embryo transfer. The presence of angiogenin in FF and GCs
was demonstrated by Western blot analysis. The production of angiogenin by
cultured GCs was stimulated with the addition of human CG or cAMP or under the
hypoxic milieu.
Ovarian localization
Granulosa, Luteal cells
Comment
Follicle stages
Primordial, Primary, Secondary, Antral, Preovulatory, Corpus luteum, Follicular fluid
Comment
The localization and mRNA expression of angiogenin in the ovarian follicle
and in the corpus luteum were different in their developmental stages. The intensities of
immunoreactivities and angiogenin transcripts in the follicle increased from the primordial to the tertiary (or Graafian) follicle. The early corpus luteum contained strong immunoreactivities and mRNA expression of angiogenin but these intensities weakened during regression Lee et al. (1999).