Amount of mRNA and localization of vascular endothelial growth factor and its receptors in the ovarian follicle during estrous cycle of water buffalo (Bubalus bubalis).

The objective of the present study was to characterize the temporal patterns of gene expression for vascular endothelial growth factors (VEGF) and VEGF receptors during ovarian follicular growth, development and maturation in buffalo (Bubalus bubalis). Follicles were classified into four groups according to size and the concentration of estradiol-17β (E2) in follicular fluid (FF): Group I (small), 4-6mm diameter, E2>0.5ng/ml of FF; Group II (medium), 7-9mm, E2=0.5-5ng/ml; Group III (large), 10-13mm, E2=5-40ng/ml; Group IV(pre-ovulatory), >13mm, E2>180ng/ml). The mRNAs for FSH receptor (FSHR), LH receptor (LHR) and aromatase (CYP19A1) in theca interna and granulosa layers were also determined, further defining the maturational state of each group. The relative expression of VEGF isoforms (120, 164, and 188 amino acid forms), as determined by quantitative real-time PCR (qRT-PCR), increased during follicular development in both the granulosa (P<0.05) and theca layers. Relative amounts of VEGF receptors (VEGFR-1 and VEGFR-2) were least in granulosa cell (GC) and theca interna cell (TI) layers of Gp-I follicles. The amount of VEGFR-2 transcripts increased in the granulosa layer throughout development, reaching a maximum in Gp-IV follicles (P<0.05). The relative amount of VEGF isoforms and receptors in follicle lysates, as determined by western blotting, increased throughout follicular maturation to maximum amounts in pre-ovulatory follicles. Immunohistochemistry revealed a clear localization of VEGF isoforms and receptors in both steroidogenic cell types (GC and TI) and of VEGF receptors in the vascular endothelial cells of the thecal blood vessels. The most intense immunofluorescence was evident in pre-ovulatory follicles compared to other smaller follicles. These data provide evidence that the VEGF may contribute to the extensive capillary proliferation associated with the increase in size, selection, and maturation of the pre-ovulatory follicle. This may facilitate follicle maturation by enhancing the supply of nutrients, hormones, and other essential blood-borne signals to the follicle. VEGF may also promote maturation of follicles through recently recognized, non-angiogenic mechanisms.

Babitha V ，Panda RP ，Yadav VP ，Chouhan VS ，Dangi SS ，Khan FA ，Singh G ，Bag S ，Taru Sharma G ，Silvia WJ ，Sarkar M ... -  《-》

[Expression of mRNAs for GHR, IGF-IR, FSHR and LHR in granulosa and theca layers of ovarian follicles of Shaoxing ducks].

Zhou YC ，Fu QG ，Zhao RQ ，Ni YD ，Chen J ... -  《-》

The expression of angiogenic growth factors and their receptors in ovarian follicles throughout the estrous cycle in the ewe.

Healthy follicles are highly vascularized whereas those undergoing atresia have poor vascularity, suggesting a relationship between follicular vascularization and follicular function. Vascularization is regulated by angiogenic factors, and among them vascular endothelial growth factor (VEGF) and angiopoietin-Tie (Ang-Tie) systems are of central importance. The objectives of this study were to determine if VEGF, VEGF receptor-2 (VEGFR-2), and components of the Ang-Tie system are expressed in ovarian follicles at both the protein and mRNA levels and to explore if their expression is related to the stage of the estrous cycle in the ewe. Ovaries from cyclic ewes were collected during the luteal phase (n=5) or before (n=5), during (n=4), and after (n=4) the preovulatory luteinizing hormone (LH) surge. After fixation, ovaries were wax-embedded, serially sectioned, and analyzed for both protein and mRNA expression of VEGF, VEGFR-2, angiopoietin-1 (Ang-1), angiopoietin-2 (Ang-2), Tie-1 (mRNA only), and Tie-2. mRNA was studied by in situ hybridization using digoxigenin-11-UTP-labeled ovine riboprobes. A similar pattern of expression was observed for mRNA and protein for all of the factors. Both mRNA and protein expression of VEGF, VEGFR-2, Ang-1, Ang-2, Tie-1 (mRNA only), and Tie-2 in the granulosa and theca cells of follicles >or=2mm in diameter was significantly different among the stages of the estrous cycle, with the highest expression detected at the post-LH surge stage. Theca cells expressed significantly greater levels of the six angiogenic factors compared with granulosa cells at all stages of the estrous cycle. Expression levels in granulosa and theca cells were comparable between small (2.0 to 2.5mm) and medium (2.5 to 4.0mm) follicles, but large follicles (>4.0mm) expressed higher mRNA and protein levels (all P<0.05) for all factors at all stages of the estrous cycle. These data show (i) that VEGF, VEGFR-2, and the Ang-Tie system are present in both granulosa and theca cells of the ovarian follicle, (ii) that thecal cells consistently express greater levels of all of these factors compared with granulosa cells, and (iii) that their levels of expression are related to the stage of the estrous cycle and to follicle size.

Chowdhury MW ，Scaramuzzi RJ ，Wheeler-Jones CP ，Khalid M ... -  《-》

Expression and localization of fibroblast growth factor (FGF) family in buffalo ovarian follicle during different stages of development and modulatory role of FGF2 on steroidogenesis and survival of cultured buffalo granulosa cells.

The present study investigated the expression and localization of FGF and its functional receptors in the follicle of buffalo and the treatment of FGF2 on mRNA expression of CYP19A1 (aromatase), PCNA, and BAX (BCL-2 associated X protein) in cultured buffalo granulosa cells (GCs). Follicles were classified into four groups based on size and E2 level in follicular fluid (FF): F1, 4-6mm diameter, E2<0.5ng/ml of FF; F2, 7-9mm, E2=0.5-5ng/ml; F3, 10-13mm, E2=5-40ng/ml; F4, >14mm, E2>180ng/ml. The qPCR studies revealed that the mRNA expression of FGF1, FGF2 and FGF7 were maximum (P<0.05) in theca interna (TI) whereas the transcripts of FGFR1, FGFR2, FGFR2IIIB and FGFR2IIIC were up-regulated (P<0.05) in GCs of F4 follicles. Protein expression of most members were maximum (P<0.05) in F4 follicles except FGFR3 and FGFR4. All members were localized in GC and TI with a stage specific immunoreactivity. Primary culture of GCs with treatment of FGF2 at different dose-time combinations revealed that the mRNA expression and immunoreactivity of CYP19A1 and PCNA were maximum (P<0.05) whereas BAX was minimum (P<0.05) with 200ng/ml at 72h of incubation. The findings indicate that FGF family members are expressed in a regulated manner in buffalo ovarian follicles during different stages of development where FGF2 may promote steroidogenesis and GC survival through autocrine and paracrine manner.

Mishra SR ，Thakur N ，Somal A ，Parmar MS ，Reshma R ，Rajesh G ，Yadav VP ，Bharti MK ，Bharati J ，Paul A ，Chouhan VS ，Sharma GT ，Singh G ，Sarkar M ... -  《-》

Expression of messenger ribonucleic acids of luteinizing hormone and follicle-stimulating hormone receptors in granulosa and theca layers of chicken preovulatory follicles.

Zhang C ，Shimada K ，Saito N ，Kansaku N ... -  《GENERAL AND COMPARATIVE ENDOCRINOLOGY》