Ovine forestomach matrix biomaterial is a broad spectrum inhibitor of matrix metalloproteinases and neutrophil elastase.

Proteases play a critical role in the ordered remodelling of extracellular matrix (ECM) components during wound healing and tissue regeneration. However, the usually ordered proteolysis is compromised in chronic wounds due to over-expression and high concentrations of matrix metalloproteinase's (MMPs) and neutrophil elastase (NE). Ovine forestomach matrix (OFM) is a decellularised extracellular matrix-based biomaterial developed for tissue regeneration applications, including the treatment of chronic wounds, and is a heterogeneous mixture of ECM proteins and proteoglycans that retains the native structural and functional characteristics of tissue ECM.

Effects of immunizing ewes against bone morphogenetic protein 15 on their responses to exogenous gonadotrophins to induce multiple ovulations.

Sheep with a heterozygous inactivating mutation in the bone morphogenetic protein 15 (BMP15) gene experience an increased ovulation rate during either a natural oestrous cycle or a cycle in which exogenous FSH and eCG (gonadotrophins) are given to induce multiple ovulations. The primary aim of these studies was to determine whether ewes immunised against BMP15 would also show an improved superovulation rate following exogenous gonadotrophin treatment. A secondary aim was to determine the effects of BMP15 immunisation on ovarian follicular characteristics.

Quantification of in vitro and in vivo angiogenesis stimulated by ovine forestomach matrix biomaterial.

Ovine forestomach matrix (OFM) biomaterial acts as a biomimetic of native extracellular matrix (ECM) by providing structural and functional cues to orchestrate cell activity during tissue regeneration. The ordered collagen matrix of the biomaterial is supplemented with secondary ECM-associated macromolecules that function in cell adhesion, migration and communication. As angiogenesis and vasculogenesis are critical processes during tissue regeneration we sought to quantify the angiogenic properties of the OFM biomaterial.

Signalling pathways involved in the cooperative effects of ovine and murine GDF9+BMP15-stimulated thymidine uptake by rat granulosa cells.

Growth differentiation factor 9 (GDF9) and bone morphogenetic protein 15 (BMP15) are oocyte-secreted factors known to be involved in regulating the proliferation and differentiation of granulosa cells during follicular growth. The aims of this study were to determine the signalling pathways used by recombinant forms of murine and ovine GDF9 and BMP15 in combination (GDF9+BMP15) and the molecular complexes formed by combinations of these factors. Differences in the molecular forms of combinations of murine and ovine GDF9+BMP15 were observed by western blot analysis.

Biophysical characterization of ovine forestomach extracellular matrix biomaterials.

Ovine forestomach matrix (OFM) is a native and functional decellularized extracellular matrix biomaterial that supports cell adhesion and proliferation and is remodeled during the course of tissue regeneration. Small angle X-ray scattering demonstrated that OFM retains a native collagen architecture (d spacing = 63.5 ± 0.

The conflict between hierarchical ovarian follicular development and superovulation treatment.

In mammals with a low ovulation rate phenotype, ovarian follicular development is thought to be hierarchical with few, if any, antral follicles at similar stages of development. The hypothesis being tested herein was that if most follicles are in a functionally different state, then the application of exogenous hormones to increase ovulation rate will not overcome the hierarchical nature of follicular development. Using sheep as the experimental model, the functional states of all non-atretic antral follicles > or =2 mm diameter were assessed in individual ewes (N=10/group) during anoestrus with or without pregnant mare's serum gonadotrophin (PMSG) treatment, or after a standard superovulation regimen, or during the follicular phase of the oestrous cycle.

A functional extracellular matrix biomaterial derived from ovine forestomach.

Extracellular matrix (ECM) based biomaterials have an established place as medical devices for wound healing and tissue regeneration. In the search for biomaterials we have identified ovine forestomach matrix (OFM), a thick, large format ECM which is biochemically diverse and biologically functional. OFM was purified using an osmotic process that was shown to reduce the cellularity of the ECM and aid tissue delamination.

Gonadotrophin-responsiveness of granulosa cells from bone morphogenetic protein 15 heterozygous mutant sheep.

The aim of this study was to test the hypothesis that the higher ovulation-rate in ewes heterozygous for a mutation in bone morphogenetic protein 15 (BMP15; FecX(I); otherwise known as Inverdale or I+ ewes) is due to granulosa cells developing an earlier responsiveness to LH, but not FSH. To address this hypothesis, granulosa cells were recovered from every individual nonatretic antral follicle (>2.5 mm diameter) from I+ and wild-type (++) ewes during anoestrus and the luteal and follicular phases and tested for their responsiveness to FSH and human chorionic gonadotrophin (hCG; a surrogate for LH).

The proregion of mouse BMP15 regulates the cooperative interactions of BMP15 and GDF9.

Bone morphogenetic protein 15 (BMP15) and growth and differentiation factor 9 (GDF9) are secreted by the mammalian oocyte and are essential for ovarian follicular development, ovulation, and fertility. However, the secreted forms of the BMP15 and GDF9 proteins and the nature of cooperative molecular interactions between BMP15 and GDF9 previously reported have not been fully characterized. In this study, we found that recombinant mouse BMP15 and GDF9 are secreted as cleaved mature and proregion proteins, with BMP15 also secreted as uncleaved promature protein.

Characterization of recombinant human growth differentiation factor-9 signaling in ovarian granulosa cells.

Growth differentiation factor-9 (GDF9) is an oocyte secreted paracrine factor essential for mammalian ovarian folliculogenesis. Like other members of the transforming growth factor-beta (TGFbeta) superfamily, GDF9 is synthesized as a prepropeptide which needs processing by furin-like proteases to result in an active mature protein. We have previously characterized a preparation of unpurified recombinant mouse GDF9 which is bioactive as produced by human embryonic kidney 293T (HEK-293T) cells.

The cooperative effect of growth and differentiation factor-9 and bone morphogenetic protein (BMP)-15 on granulosa cell function is modulated primarily through BMP receptor II.

Growth and differentiation factor 9 (GDF9) and bone morphogenetic protein 15 (BMP15, GDF9B) are oocyte-derived proteins essential for the growth and function of ovarian follicles. Moreover, ovine (o) GDF9 and oBMP15 cooperate to increase both (3)H-thymidine incorporation and alpha-inhibin production and to inhibit progesterone production by rat or ovine granulosa cells. Although the receptors through which these proteins act individually have been determined, the receptor(s) involved in mediating the cooperative effects of GDF9 and BMP15 is (are) unknown.

The effects of immunizing sheep with different BMP15 or GDF9 peptide sequences on ovarian follicular activity and ovulation rate.

The aims of these studies were to determine the abilities of antisera against different regions of ovine bone morphogenetic protein 15 (BMP15) and growth differentiation factor 9 (GDF9) to inhibit ovarian follicular activity, estrus (mating), and ovulation in sheep. The 9-15-mer peptides were conjugated to keyhole limpet hemocyanin (KLH) and used to generate antibodies against the flexible N-terminal regions of the mature protein as well as against regions in which dimerization of the protein or interaction with a type 1 BMP or a type 2 TGFB or BMP receptor was predicted to occur. Ewes (n = 10 per treatment group) were vaccinated with KLH or the KLH-BMP15 (n = 9 different peptides) or KLH-GDF9 (n = 10) peptides in Freund adjuvant at five consecutive monthly intervals.

The role of bone morphogenetic proteins 2, 4, 6 and 7 during ovarian follicular development in sheep: contrast to rat.

The intraovarian roles of BMP family members such as BMP2, 4, 6 and 7 are not well understood, particularly in species with low ovulation rates such as sheep. Therefore, the objectives of these experiments were to determine the expression patterns of mRNAs encoding BMP2, 4, 6 and 7 during ovarian follicular development in sheep, and to determine the effects of these growth factors on ovine granulosa cell functions in vitro. For comparative purposes, the effects of these BMPs were also determined in rat granulosa cells since these factors have been most widely studied in this poly-ovulatory species.

Bone morphogenetic protein 15 and growth differentiation factor 9 co-operate to regulate granulosa cell function in ruminants.

The oocyte-secreted polypeptide growth factors, growth differentiation factor 9 (GDF9) and bone morphogenetic protein 15 (BMP15, also known as GDF9B) have both been shown to be essential for ovarian follicular development and ovulation rate. In addition, it is known from both in vivo and in vitro studies that these factors co-operate in some manner. To date, most studies examining the in vitro effects of these growth factors have used the rodent model.

Bone morphogenetic protein 15 and growth differentiation factor 9 co-operate to regulate granulosa cell function.

The oocyte-secreted polypeptide growth factors, growth differentiation factor 9 (GDF9) and bone morphogenetic protein 15 (BMP15, also known as GDF9B) have both been shown to be essential for ovarian follicular growth and function. The effects of murine (m) and ovine (o) GDF9 as well as oBMP15, alone or together, on 3H-thymidine uptake and progesterone and inhibin production by granulosa cells from rats were determined. Murine GDF9 stimulated thymidine incorporation by granulosa cells whereas oGDF9 and oBMP15 alone had no effect.

The role of transforming growth factor-beta (TGF-beta) during ovarian follicular development in sheep.

Background: Recently, several members of the transforming growth factor-beta (TGF-beta) superfamily have been shown to be essential for regulating the growth and differentiation of ovarian follicles and thus fertility.

Methods: Ovaries of neonatal and adult sheep were examined for expression of the TGF-betas 1-3 and their receptors (RI and RII) by in situ hybridization using ovine cDNAs. The effects of TGF-beta 1 and 2 on proliferation and differentiation of ovine granulosa cells in vitro were also studied.

The corpus luteum and interstitial tissue in a marsupial, the brushtail possum (Trichosurus vulpecula).

The Australian brushtail possum (Trichosurus vulpecula) is a nocturnal, arboreal marsupial. It has become a pest of significant ecological and economic importance in New Zealand, and thus a renewed interest in understanding the reproductive biology of this species has been generated. The corpus luteum (CL) in possums is a largely autonomous gland in that it does not rely on pituitary hormones to function and is not responsive to luteolytic agents for its demise.

Origins of follicular cells and ontogeny of steroidogenesis in ovine fetal ovaries.

Using fetal sheep as the experimental model, we have elucidated some of the key events that culminate in the formation of primordial follicles. A special effort was made to determine the source of the somatic cells that ultimately become granulosa cells of primordial follicles. Between gestational days 38-100: (1) light and electron microscopy was used to characterize changes in ovarian histoarchitecture; (2) incorporation of BrdU was used to identify populations of proliferating cells within fetal ovaries before, during and after, follicular formation; and (3) in situ hybridisation was used to determine the cell-specific and temporal patterns of expression of mRNAs encoding for selected steroidogenic enzymes.

Ovarian expression of messenger RNA encoding the receptors for luteinizing hormone and follicle-stimulating hormone in a marsupial, the brushtail possum (Trichosurus vulpecula).

Both LH and FSH play a central role in controlling ovarian function in mammals. However, little is known about the type of ovarian cells that are responsive to LH and FSH in marsupials. We determined, using in situ hybridization, the localization of mRNA encoding the receptors (R) for LH and FSH in ovaries of brushtail possums.