Use of pregnancy-associated plasma protein-A during oocyte in vitro maturation increases IGF-1 and affects the transcriptional profile of cumulus cells and embryos from Nelore cows.

Insulin-like growth factor 1 (IGF-1) activity is established by the regulation of IGF binding protein activity, which blocks IGF-1 functions, whereas pregnancy-associated plasma protein-A (PAPP-A) improves IGF-1 bioavailability and facilitates binding to IGF receptors. To further extend our understanding of the effect of exogenous PAPP-A on bovine embryo production, we added this protein during in vitro maturation of cumulus-oocyte complexes (COCs); moreover, we assessed its effects on IGF-1 quantity in the maturation medium, embryonic yield and postwarming survival, blastocyst quality, and transcript abundance. Bovine COCs were matured in a serum-free medium, either with PAPP-A supplementation (100 ng/ml) or without (control). The treatment group produced higher IGF-1 concentrations in the maturation medium; however, showed no difference on cleavage, blastocysts rates, and embryonic survival 3 and 24 hr postcryopreservation. Regarding gene expression, VNN1 was upregulated, whereas AGPAT9, FASN, EGFR, HAS2, and IMPDH1 were downregulated in PAPP-A treated. PAPP-A treated, CPT2, DNMT3A, and TFAM were upregulated, whereas ATF4 and IFITM3 were downregulated. We concluded that although the addition of PAPP-A did not affect embryo yield and blastocyst survival, higher IGF-1 levels may affect embryo competence through differential expression of genes involved in lipid metabolism, oocyte competence, and mitochondrial function.

Equine chorionic gonadotropin increases estradiol levels in the bovine oviduct and drives the transcription of genes related to fertilization in superstimulated cows.

In the bovine oviduct, estradiol (E2) stimulates secretion and cell proliferation, whereas progesterone (P4) suppresses them. In this study, we have evaluated the effect of two superstimulatory protocols (follicle-stimulating hormone [FSH] or FSH combined with equine chorionic gonadotropin [eCG]) on the oviductal levels of E2 and P4 and its outcome on oviductal cells. Compared with the control group (a single pre-ovulatory follicle), we have observed that the cows submitted to FSH/eCG treatment showed a higher concentration of E2 in the oviduct tissue, together with a higher abundance of messenger RNA encoding steroid receptors (ESR1 and progesterone receptor), and genes linked to gamete interactions and regulation of polyspermy (oviduct-specific glycoprotein 1, heat-shock protein family A member 5, α-l-fucosidase 1 [FUCA1], and FUCA2) in the infundibulum and ampulla segments of the oviduct. However, we did not observe any modulation of gene expression in the isthmus segment. Even though the FSH protocol upregulated some of the genes analyzed, we may infer that the steady effect of FSH combined with eCG on oviduct regulation might benefit fertilization and may potentially increase pregnancy rates.

Fibroblast growth factor 18 regulates steroidogenesis in fetal bovine ovarian tissue in vitro.

In cattle and other species, the fetal ovary is steroidogenically active before follicular development commences, and there is evidence that estradiol and progesterone inhibit follicle formation and activation. Estradiol levels decline sharply around the time of follicle formation. In the present study, we hypothesized that FGF10 and FGF18, which inhibit estradiol secretion from granulosa cells of antral follicles, also regulate fetal ovarian steroid production. Fetuses were collected at local abattoirs, and age determined by crown-rump length measurements. Real-time polymerase chain reaction assays with RNA extracted from whole ovaries revealed that the abundance of CYP19A1 messenger RNA (mRNA) decreased from 60 to 90 days of gestation, which is consistent with the decline in estradiol secretion previously observed. Immunohistochemistry revealed the presence of FGF18 in ovigerous cords in early gestation and in oocytes later in fetal age (≥150 days). The abundance of FGF18 mRNA increased after Day 90 gestation. Addition of recombinant FGF18 to fetal ovarian pieces inhibited estradiol and progesterone secretion in vitro, whereas FGF10 was without effect. Consistent with these results, FGF18 decreased levels of mRNA for CYP19A1 and CYP11A1 in ovarian pieces in vitro. These data suggest that FGF18 may be an intraovarian factor that regulates steroidogenesis in fetal ovaries.

Modulation of inflammatory and hormonal parameters in response to testosterone therapy: Effects on the ventral prostate of adult rats.

Testosterone is often recommended in the treatment of several aging-related conditions. However, there are still questions about the consequences of this therapy in terms of hormonal and inflammatory parameters that are crucial for prostate homeostasis. Thus, we investigate if the testosterone therapy (TT) modulates the hormone receptors and inflammatory cytokines in the ventral prostate of adult rats. Wistar rats aging 150 days were divided into two experimental groups (n = 10/group): T: received subcutaneous injections of testosterone cypionate (5 mg/kg body weight) diluted in corn oil every other day for 4 weeks; and C: received corn oil as vehicle. Animals were euthanized at 180 days old by decapitation. Blood was collected to obtain hormone and cytokines concentrations. The ventral prostate was dissected and processed for light microscope and molecular analyses. Relative ventral prostate weight and epithelial compartment were increased after TT. The number of intact and degranulated mast cells was reduced in the T group. Plasma testosterone, DHT and intraprostatic testosterone concentrations were higher in the T group. TT leads to an increase in cell proliferation and up-regulation of AR, ERß, PAR-4, and NRF2. Importantly, plasma concentration and tissue expression of IL-10 and TNF-α were higher after TT. In summary, these results indicate that TT can regulate inflammatory response, with impacts in cytokines and mast cell population, and modulates steroids receptors, important parameters for prostatic homeostasis.

Contraction of Rat Cauda Epididymis Smooth Muscle to α1-Adrenoceptor Activation Is Mediated by α1A-Adrenoceptors.

The cauda epididymis (CE), the site of sperm storage until the ejaculation, is densely innervated by the sympathetic nervous system. Contraction of CE smooth muscle via α1-adrenoceptors (α1-ARs) plays a key role during the seminal emission phase of ejaculation and α1-AR antagonism has been suggested as a nonhormonal and reversible male contraceptive target. Since the α1-AR subtype mediating contraction of rat CE is not known, this study investigates the expression and role of α1-AR subtypes on the proximal and distal rat CE duct contraction to norepinephrine in vitro. Alpha1a, α1b, and α1d transcripts were detected by real-time quantitative polymerase chain reaction in proximal and distal CE segments and α1a and α1d were shown to predominate over α1b The inhibition of [3H]prazosin specific binding to intact CE segments from proximal and distal CE by RS 100329 and 5-methylurapidil (α1A-selective) and BMY 7378 (α1D-selective) showed that α1A- and α1D-ARs are expressed at similar densities. Norepinephrine-induced contractions of CE were competitively antagonized with high affinity by RS 100329 (pKB ≈ 9.50) and 5-methylurapidil (pKB ≈ 9.0) and with low affinity by BMY 7378 (pKB ≈ 7.0) and the α1B-selective L-765,314 (pA2 < 7.0), suggesting contractions are mediated by α1A-ARs. The clinically used α1A/D-ARs antagonist tamsulosin potently (pA2 ≈ 10.0) inhibited the norepinephrine-induced CE contractions. Altogether, our results show that α1A- and α1D-ARs are expressed in the CE duct and α1A-AR is the main subtype mediating contraction to norepinephrine. Our results highlight the importance of α1A-AR in the peripheral control of ejaculation and strengthen the α1A-AR as a target for a nonhormonal approach to male contraception.

Treatment with cyclic adenosine monophosphate modulators prior to in vitro maturation alters the lipid composition and transcript profile of bovine cumulus-oocyte complexes and blastocysts.

Mammalian oocytes resume meiosis spontaneously after removal from the ovarian follicle. We tested the effects of a 2-h prematuration treatment (Pre-IVM) with forskolin (FSK) and 3-isobutyl-1-methylxanthine (IBMX) in bovine cumulus-oocyte complexes (COCs) on the lipid content of oocytes and blastocysts, on the membrane lipid composition of blastocysts and on the transcriptional profiling of cumulus cells and blastocysts in a high-throughput platform. Embryonic development rates to the morula (mean 56.1%) or blastocyst (mean 26.3%) stages were unaffected by treatment. Lipid content was not affected after Pre-IVM, but was increased after IVM in treated oocytes. Conversely, the lipid content was reduced in Pre-IVM blastocysts. Pre-IVM COCs generated blastocysts containing blastomeres with more unsaturated lipids in their membranes. Pre-IVM also altered the relative abundance of 31 gene transcripts after 2h and 16 transcripts after 24h in cumulus cells, while seven transcripts were altered in blastocysts. Our results suggest that the Pre-IVM treatment affected the lipid composition and transcriptional profiles of COCs and blastocysts. Therefore, Pre-IVM with FSK and IBMX could be used either to prevent spontaneous meiotic resumption during IVM or to modulate lipid composition in the membrane and cytoplasm of blastocysts, potentially improving bovine embryos.

Experimental evidence of heparanase, Hsp70 and NF-κB gene expression on the response of anti-inflammatory drugs in TNBS-induced colonic inflammation.

AIM: Etiopathogenesis of inflammatory bowel disease is unclear and results from a complex interplay of genetic, microbial, environmental and immune factors. Elucidating the mechanisms that drive IBD depends on the detailed characterization of human inflammatory mediators in animal models. Therefore, we studied how intestinal inflammation affects heparanase, NF-κB and Hsp70 gene expression in rats, and if current intestinal anti-inflammatory drugs (sulphasalazine, prednisolone and azathioprine) act on these expressions. Moreover, we investigated the relationships among these genes with colonic cytokines levels (IL-1ß, TNF-α, IL-6, INF-γ and IL-10) and oxidative stress that have fundamental role in IBD. MATERIAL AND METHODS: Macroscopic parameters (diarrhea, extension of lesion, colonic weight/length ratio and damage score), biochemical markers (myeloperoxidase and alkaline phosphatase activities, and glutathione, IL-1ß, TNF-α, IL-6, INF-γ and IL-10 levels), gene expressions (heparanase, NF-κB and Hsp70), and microscopic evaluations (optic, electronic scanning and transmission microscopic) were performed in rats. KEY FINDINGS: Expression of heparanase, Hsp70 and NF-κB and oxidative stress were increased by inflammatory process and differentially modulated by sulphasalazine, prednisolone and azathioprine treatments. Protective effects of drugs were also related to differential modulation of cytokine changes induced by inflammatory process, showing different mechanisms to control inflammation. SIGNIFICANCE: Heparanase, NF-κB and Hsp70 gene expression participate in the inflammatory response induced by TNBS and represent pharmacological targets of the intestinal anti-inflammatory drugs. In addition, current drugs used to treat IBD (sulphasalazine, prednisolone and azathioprine) differentially modulate heparanase, NF-κB and Hsp70 gene expression, cytokine production and oxidative stress.

Maternal protein restriction during pregnancy affects gene expression and immunolocalization of intestinal nutrient transporters in rats.

Intrauterine dietary restriction may cause changes in the functioning of offspring organs and systems later in life, an effect known as fetal programming. The present study evaluated mRNA abundance and immunolocalization of nutrient transporters as well as enterocytes proliferation in the proximal, median and distal segments of small intestine of rats born to protein-restricted dams. Pregnant rats were fed hypoproteic (6% protein) or control (17% protein) diets, and offspring rats were evaluated at 3 and 16 weeks of age. The presence of SGLT1 (sodium-glucose co-transporter 1), GLUT2 (glucose transporter 2), PEPT1 (peptide transporter 1) and the intestinal proliferation were evaluated by immunohistochemical techniques and the abundance of specific mRNA for SGLT1, GLUT2 and PEPT1 was assessed by the real-time PCR technique. Rats born to protein-restricted dams showed higher cell proliferation in all intestinal segments and higher gene expression of SGLT1 and PEPT1 in the duodenum. Moreover, in adult animals born to protein-restricted dams the immunoreactivity of SGLT1, GLUT2 and PEPT1 in the duodenum was more intense than in control rats. Taken together, the results indicate that changes in the small intestine observed in adulthood can be programmed during the gestation. In addition, they show that this response is caused by both up-regulation in transporter gene expression, a specific adaptation mechanism, and intestinal proliferation, an unspecific adaptation mechanism.

Effect of superstimulatory treatments on the expression of genes related to ovulatory capacity, oocyte competence and embryo development in cattle.

Multiple ovulation (superovulation) and embryo transfer has been used extensively in cattle. In the past decade, superstimulatory treatment protocols that synchronise follicle growth and ovulation, allowing for improved donor management and fixed-time AI (FTAI), have been developed for zebu (Bos indicus) and European (Bos taurus) breeds of cattle. There is evidence that additional stimulus with LH (through the administration of exogenous LH or equine chorionic gonadotrophin (eCG)) on the last day of the superstimulatory treatment protocol, called the 'P-36 protocol' for FTAI, can increase embryo yield compared with conventional protocols that are based on the detection of oestrus. However, inconsistent results with the use of hormones that stimulate LH receptors (LHR) have prompted further studies on the roles of LH and its receptors in ovulatory capacity (acquisition of LHR in granulosa cells), oocyte competence and embryo quality in superstimulated cattle. Recent experiments have shown that superstimulation with FSH increases mRNA expression of LHR and angiotensin AT(2) receptors in granulosa cells of follicles >8 mm in diameter. In addition, FSH decreases mRNA expression of growth differentiation factor 9 (GDF9) and bone morphogenetic protein 15 (BMP15) in oocytes, but increases the expression of both in cumulus cells, without diminishing the capacity of cumulus-oocyte complexes to generate blastocysts. Although these results indicate that superstimulation with FSH is not detrimental to oocyte competence, supplementary studies are warranted to investigate the effects of superstimulation on embryo quality and viability. In addition, experiments comparing the cellular and/or molecular effects of adding eCG to the P-36 treatment protocol are being conducted to elucidate the effects of superstimulatory protocols on the yield of viable embryos.

Ovulation rate and its relationship with follicle diameter and gene expression of the LH receptor (LHR) in Nelore cows.

The objective was to determine the relationship among the diameter of ovarian follicles, ovulation rate, and gene expression of the LH receptor (LHR) in Nelore cattle. In Experiment 1, ovulation was synchronized in 53 Nelore cows. Three days after ovulation, ovaries were assessed with ultrasonography, all cows were given 6.25 mg LH im, and they were allocated into three groups, according to diameter of their largest ovarian follicle: G1 (7.0-8.0 mm); G2 (8.1-9.0 mm); and G3 (9.1-10.0 mm). For these three groups, ovulation rates were 9, 36, and 90%, respectively, (P<0.03; each rate differed significantly from the other two). In Experiment 2, granulosa and theca cells were subjected to total RNA extraction, and gene expression of the LHR was determined by RT-PCR. Follicles were allocated in three groups based on their diameter (similar to the Experiment 1), which were denoted Groups A, B, and C. Expression of the LHR gene in granulosa cells was lower in Group A than Group C (P<0.05). However, there were no significant differences among groups in expression of the LHR gene in theca cells. We concluded that ovulatory capacity in Nelore cattle was related to increased follicular diameter and expression of the LHR gene in granulosa cells.