This gene was found through a mouse ovarian follicle microarray.
NCBI Summary:
This gene encodes a member of the Notch family. Members of this Type 1 transmembrane protein family share structural characteristics including an extracellular domain consisting of multiple epidermal growth factor-like (EGF) repeats, and an intracellular domain consisting of multiple, different domain types. Notch family members play a role in a variety of developmental processes by controlling cell fate decisions. The Notch signaling network is an evolutionarily conserved intercellular signaling pathway which regulates interactions between physically adjacent cells. In Drosophilia, notch interaction with its cell-bound ligands (delta, serrate) establishes an intercellular signaling pathway that plays a key role in development. Homologues of the notch-ligands have also been identified in human, but precise interactions between these ligands and the human notch homologues remain to be determined. This protein is cleaved in the trans-Golgi network, and presented on the cell surface as a heterodimer. This protein functions as a receptor for membrane bound ligands, and may play a role in vascular, renal and hepatic development. This gene may be associated with susceptibility to schizophrenia in a small portion of cases. An alternative splice variant has been described but its biological nature has not been determined.
Intraovarian regulation of gonadotropin-dependent folliculogenesis depends on notch receptor signaling pathways not involving Delta-like ligand 4 (Dll4). Jovanovic VP et al. BACKGROUND: In-situ hybridisation studies demonstrate that Notch receptors and ligands are expressed in granulosa cells (GCs) and in the theca layer vasculature of growing follicles. Notch signaling involves cell-to-cell interaction mediated by transmembrane receptors and ligands. This signaling pathway may represent a novel intraovarian regulator of gonadotropin-dependent follicular development to the preovulatory stage. We hypothesized that blocking Notch pathways would disrupt follicular maturation in the mouse ovary. METHODS: Hypophysectomized CD21 female mice were administered pregnant mare serum gonadotropin (PMSG) for 3 days to stimulate follicular development. In one experiment, a pan-notch inhibitor, compound E, was initiated 2 days prior to and throughout stimulation (n = 10), while in a second experiment, a humanized phage Dll4 blocking antibody, YW152F, was used (n = 5). After sacrifice, ovarian histology, serum estradiol levels and uterine weights were compared to controls. The ovarian morphology was evaluated with hematoxylin/eosin staining and immunohistochemistry was performed for Notch1, Notch2, Notch3, Notch4, Jagged1, Dll4, platelet endothelial cell adhesion molecule (PECAM) and alpha-smooth muscle actin (alpha-SMA) detection. RESULTS: We localized specific Notch ligands and receptors in the following structures: Dll4 is specific to theca layer endothelial cells (ECs); Notch1/Notch4 and Jagged1 are expressed in theca layer ECs and vascular smooth muscle cells (VSMCs), whereas Notch3 is restricted to VSMCs; Notch2 is expressed mostly on GCs of small follicles. Administration of a pan-Notch inhibitor, compound E, inhibits follicular development to the preovulatory stage (8.5 preovulatory follicles in treatment vs. 3.4 preovulatory follicles in control, p < 0.01; average number per ovary) with significant secondary effects on ovarian and uterine weight and estradiol secretion in a setting of uninhibited vascular proliferation, but disorganized appearance of ECs and VSMCs. Inhibition of endothelial Notch1 function through the inactivation of its ligand Dll4 with the blocking antibody YW152F induces mild disorganisation of follicular vasculature, but has no significant effect on gonadotropin-dependent folliculogenesis. CONCLUSIONS: Our experiments suggest that the complete blockage of the Notch signaling pathway with compound E impairs folliculogenesis and induces disruption of gonadotropin stimulated angiogenesis. It seems the mechanism involves Notch1 and Notch3, specifically, causing the improper assembly of ECs and VSMCs in the theca layer, although the potential role of non-angiogenic Notch signaling, such as Jagged2 to Notch2 in GCs, remains to be elucidated.
/////Role of the DLL4-NOTCH System in PGF2alpha-Induced Luteolysis in the Pregnant Rat. Hernandez F et al. We investigated the expression and cell localization of NOTCH1, NOTCH4 and the ligand DlLL4 in corpus luteum (CL) from pregnant rats during PGF2alpha-induced luteolysis. We also examined serum progesterone (P(4)) and CL proteins related to apoptosis after local administration of the notch inhibitor DAPT. Specific staining for NOTCH1 and 4 receptors was detected predominantly in large and small luteal cells. Furthermore, the staining was evident in the nuclei of luteal cells in coincidence with the fact that the notch intracellular domain is translocated to the nucleus, where it regulates gene expression. Additionally, we detected diffuse cytoplasmic immunostaining for DLL4 in small and large luteal cells, in accordance with the information that DLL4 undergoes proteolytic degradation after receptor binding. The mRNA expression of Notch1, Notch4 and Dll4 in CL isolated on Day 19 of pregnancy decreased significantly after the administration of PGF2alpha. Consistent with the mRNA results, administration of PGF2alpha to pregnant rats on Day 19 of pregnancy decreased the protein fragment corresponding to the cleaved forms of NOTCH1/4 CL receptors. In contrast, no significant changes were detected in protein levels for the ligand DLL4. The local intrabursal administration of DAPT decreased serum P(4) levels, increased luteal levels of active CASP3 and the BAX/BCL2 ratio 24 h after the treatment. These results support a luteotropic role for notch signaling to promote luteal cell viability and steroidogenesis, and suggest that the luteolytic hormone PGF2alpha may act in part by reducing the expression of some notch system members.
Johnson J, et al. (Mech Dev. 2001) studied the expression pattern of notch family. In situ hybridization data showed that Notch1 and Notch4 were expressed in the ovary, but were restricted to the vasculature.
Follicle stages
Corpus luteum
Comment
Unique patterns of Notch1, Notch4 and Jagged1 expression in ovarian vessels during folliculogenesis and corpus luteum formation Vorontchikhina MA, et al .
Notch signaling functions to regulate cell-fate decisions by modulating differentiation, proliferation, and survival of cells. Notch receptors and ligands are expressed in embryonic vasculature and are required for the remodeling of the primary embryonic vasculature of mice. Here, we characterize the expression patterns of Notch1, Notch4, and Jagged1 proteins during the process of folliculogenesis and corpus luteum formation in the mouse ovary, an organ with dynamic physiological angiogenic growth. These Notch proteins and ligand are expressed in a subset of ovarian vessels, including both mature ovarian vasculature as well as angiogenic neovessels. Their expression in the ovary was found in both endothelial and vascular associated mural cells. Our data suggest a complex regulatory role for the Notch signaling pathway during mouse oogenesis and ovarian neovascularization.