activin


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ac·tiv·in

(ak'ti-vin),
Placental hormone that reaches maximum levels in maternal serum during labor; helps to regulate production of gonadotropin-releasing hormones, human chorionic gonadotropin, and steroids by the placenta.
[active + -in]

activin

(ăk′tə-vĭn, ăk-tĭv′ĭn)
n.
A polypeptide growth factor that is synthesized in the pituitary gland and the gonads and stimulates the secretion of follicle-stimulating hormone.

Activin

Either of two dimeric proteins belonging to the TGF-beta superfamily (as do inhibin and bone morphogenic protein) which act primarily through SMADs, a class of signal transducers, which are involved in DNA-binding and signal transduction. Activins are involved in all stages of the cell cycle: proliferation, differentiation, metabolism, homeostasis, and death (apoptosis), as well as immune response and tissue repair—activins A and B are highly expressed during wound repair and healing, and have yin-yang relationship with inhibin. Activins are involved in differentiation of erythroid precursors and erythroleukemia cell lines, neuronal survival, stimulation of insulin and anterior pituitary hormone secretion, regulation of the menstrual cycle, increasing FSH production and granulosa cell differentiation by binding to follistatin, an FSH release inhibitor.

ac·tiv·in

(ak'ti-vin)
Placental hormone that reaches maximum levels in maternal serum during labor.
References in periodicals archive ?
"In nature, we knew that Activin A and follistatin work in opposite ways to regulate cells," says Doetzlhofer.
In this study administration of inhibin or immunization against inhibin either actively or passively has been shown to stimulate the secretion of pituitary FSH as well as ovarian activin and E2 (unpublished data).
has dosed the first patient in a Phase 1 study evaluating investigational agent TP-0184, an activin A receptor type 1 (ACVR1) inhibitor, in patients with advanced solid tumors, the company said.
By exposing the cells to a signaling molecule at two different timepoints, the team could trigger first Wnt, then Activin, and end up with specialized cells.
Abbreviations TGF-[beta]: Transforming growth factor beta T[beta]RII: TGF-[beta] receptor II ALK5: TGF-[beta] receptor I BMP: Bone morphogenic proteins ALK1: Activin receptor-like kinase-1 EMT: Epithelial to mesenchymal transduction TME: Tumor microenvironment CTLA-4: Cytotoxic T-lymphocyte-associated antigen 4 PD-1/PD-L1: Programmed death 1 receptor and PD-1 receptor ligand 1 APCs: Antigen-presenting cells DCs: Dendritic cells MDSCs: Myeloid-derived suppressor cells Tregs: Regulatory T cells CTLs: Cytotoxic T cells NK: Natural killer cells MCP-1: Monocyte chemoattractant protein-1 (also known as CCL-2) PFS: Progression-free survival CR: Complete response PR: Partial response CRC: Colorectal cancer UrC: Metastatic urothelial cancer.
These feeder cells also secrete TGF[beta] and activin A which are involved in maintaining the pluripotency of ICM [46, 47].
Activin A, a product of fetal Leydig cells, is a unique paracrine regulator of Sertoli cell proliferation and fetal testis cord expansion.
Net increase in stimulatory input resulting from a decrease in inhibin B and an increase in activin A may contribute in part to the rise in follicular phase follicle-stimulating hormone of aging cycling women.
Previous studies researched placental (pregnancy-associated plasma protein A, human placental lactogen, inhibin A, activin A, vascular endothelial growth factor) and non-placental markers (glycodelin and vasculer endotelial growing factor) for the diagnosis of ectopic pregnancy (10,11).
Papakonstantinou and coauthors showed that the introduction of FLAG tag in human activin A led to a decrease in biological activity, which was restored upon removal of the tag [55].
We developed a homology-based model for the TGFBR2 kinase domain based on the experimentally solved structure of Activin Receptor IIA (see Figure 1) using available structural information for other members of this family of serine/threonine kinases.

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