Human Chorionic Gonadotrophin (hCG) induces changes in IFN-pathway and Interferon-Stimulated Genes (ISGs) on the bovine endometrium at Day 18 of pregnancy

We hypothesized that the hCG modulates the expression of IFNT-pathway and ISGs in bovine endometrium during early pregnancy. The aim of the current study is to evaluate the effect of hCG on IFNT-pathway signals and ISGs expression in endometrial cells. For this, 29 non-lactating cross-bread cows were used in the study and submitted to a 9-day fixed-time artificial insemination (FTAI) protocol. The day of the AI was considered Day 0 (D0), and five days (D5) after the FTAI, the cows were allocated into two groups: Control and hCG group, when a hCG group received a single dose of 2.500UI of hCG. On day 18 after FTAI (D18) cows were slaughtered and endometrial tissue samples were collected. There was no difference between the embryo recovery rate of the cows in C compared to the hCG. The hCG group increased the accessory corpus luteum formation rate. The hCG resulted in greater serum progesterone concentration in the hCG group compared to the C on Day 14. Only the expression of IFNAR2 and STAT1 were upregulated on pregnant cows of the hCG group compared to the C group. The pathway genes (JAK1, STAT2, and IRF9) were not regulated. The mRNA abundance of ISG15, MX1, MX2, and OAS1 was upregulated in pregnant cows for hCG group, compared to C group. The results show that the administration of hCG, 5 days after AI, in addition to increasing the serum progesterone, modulates the expression of IFNT-pathway and ISGs on bovine endometrium on Day 18 of pregnancy.

Bone strength is reduced in a neonatal androgenized rat model

Background

Whether polycystic ovary syndrome (PCOS) affects bone health during a woman's lifespan remains controversial. An androgenized rodent model replicated many metabolic and reproductive features of women with PCOS, and we aimed to use it to investigate the impact of androgens on microarchitecture (by micro-CT), bone mechanical strength, bone formation and resorption markers in rats with intact ovaries (SHAM) who underwent oophorectomy.

Methods

Wistar rats (Rattus norvegicus albinus) were employed for the experiments in this study. The protocol of androgenization consisted of the application of 1.25 mg s.c. testosterone propionate beteween days 2-5 of life, while the controls received the same amount of corn oil s.c. as previously established. Androgenized SHAM rats exhibited chronic anovulation identified by vaginal cytology and a reduction in the proportion of corpus luteum in the ovary in comparison to control SHAM rats. The realization of the ovariectomy or SHAM procedure occurred on Day 100 of life. All groups (n = 8) were followed-up for 180 days to address the study endpoints.

Results

Micro-CT from androgenized female rats (SHAM) showed a divergence between the trabecular and cortical bone profiles. Compared to SHAM controls, these rats had an increase in trabecular bone mass with a diminution in bone resorption C-terminal telopeptide of type 1 collagen (CTX) (p < 0.05), a concomitant decrease in cortical area and thickness in the femur, and a reduction in the strength of the femur on the mechanical test (p < 0.01).

Conclusions

Our results suggest that a reduction in the cortical thickness and cortical area observed in PCOS model rats was associated with a reduced strength of the femur, despite increased trabecular formation. Ovariectomy in the androgenized OVX group limited the progression rate of cortical bone loss, resulting in bone resistance and cortical thickness comparable to those observed in the control OVX group.

Dietary Supplementation with R-(+)-Limonene Improves Growth, Metabolism, Stress, and Antioxidant Responses of Silver Catfish Uninfected and Infected with Aeromonas hydrophila

R-(+)-limonene is a monoterpene from plants of the genus Citrus with diverse biological properties. This research evaluated the effects of dietary supplementation with R-(+)-limonene on growth, metabolic parameters in plasma and liver, and the antioxidant and stress responses in silver catfish, Rhamdia quelen, challenged or not with Aeromonas hydrophila. Fish were fed for 67 days with different doses of R-(+)-limonene in the diet (control 0.0, L0.5, L1.0, and L2.0 mL/kg of diet). On the 60th day, a challenge with A. hydrophila was performed. R-(+)-limonene in the diet potentiated the productive performance of the fish. The metabolic and antioxidant responses indicate that R-(+)-limonene did not harm the health of the animals and made them more resistant to the bacterial challenge. Histological findings showed the hepatoprotective effect of dietary R-(+)-limonene against A. hydrophila. Igf1 mRNA levels were upregulated in the liver of fish fed with an L2.0 diet but downregulated with bacterial challenge. The expression levels of crh mRNA were higher in the brains of fish fed with the L2.0 diet. However, the L2.0 diet downregulated crh and hspa12a mRNA expression in the brains of infected fish. In conclusion, the results indicated that R-(+)-limonene can be considered a good dietary supplement for silver catfish.

Energy balance and hippo effector activity in endometrium and corpus luteum of early pregnant ewes

CONTEXT

The establishment of pregnancy in cows requires uterine activity regulation of the main Hippo signalling effector yes-associated protein 1 (YAP). It remains unknown (1) how YAP activity at the corpus luteum (CL) correlates with early pregnancy-related events in ruminants; and (2) if YAP activity in the uterus and CL can be affected by metabolic disorders that may lead to pregnancy failure in ruminants.

AIMS AND METHODS

To determine the effect of early pregnancy on total and phospho-YAP expression and its transcriptional activity in the CL, we compared non-pregnant vs pregnant ewes. To understand the YAP activity dysregulation with disorders that may result in pregnancy loss, we induced negative energy balance in pregnant ewes.

KEY RESULTS AND CONCLUSIONS

Our main results indicate that early pregnancy alters the expression and activity patterns of YAP in the ovine CL but not in the endometrium. In addition, while our NEB-induced model fails to alter YAP activity at the endometrium level, we found that fasting during the first but not second week of pregnancy affects YAP activity in the CL of pregnant ewes.

IMPLICATIONS

The data presented herein provide considerable insight into the activity of a signalling pathway that may be a key player in pregnancy recognition and establishment in ewes.

YAP signaling in preovulatory granulosa cells is critical for the functioning of the EGF network during ovulation

Failure to ovulate is a major cause of infertility. The critical pathway that induces ovulation involves the EGF and MAPK phosphorylation, but studies in rodents have suggested that the Hippo activator, YAP, is also involved. It is unknown whether YAP-dependent transcriptional activity is important for the LH- or EGF-induced ovulatory cascade in monovulatory species such as the cow. Using a well-defined preovulatory GC culture system, we employed pharmacological inhibitors to demonstrate that YAP signaling is critical for expression of EGFR and downstream target genes EREG, EGR1 and TNFAIP6. Most importantly, by using an ultrasound guided follicle injection system, we also showed that the classic Hippo signaling inhibitor Verteporfin inhibits GnRH-induced ovulation in vivo in cattle. In conclusion, YAP transcriptional activity is critical for EGF-like cascade induced by LH to promote ovulation in a monovulatory species.

Possible impact of neutrophils on immune responses during early pregnancy in ruminants

The interaction between early embryo and maternal immune system for the establishment of pregnancy is the focus of several studies; however, it remains unclear. The maternal immune response needs to keep a balance between avoiding any damage to the conceptus and maintaining its function in combating microbes as well. When conceptus-maternal crosstalk cannot achieve this balance, pregnancy losses might occur. Intercommunication between mother and conceptus is fundamental during early pregnancy to dictate the outcome of pregnancy. In ruminants, the embryo reacts with the maternal system mainly via interferon tau (IFNT) release. IFNT can act locally on the embryo and endometrial cells and systemically in several tissues and cells to regulate their response via the expression of interferon-stimulated genes (ISGs). Also, IFNT can induce the expression of inflammatory-related genes in immune cells. Day 7 embryo induces a shift in the maternal immune response towards anti-inflammatory (Th2) immune responses. During maternal recognition of pregnancy, peripheral mononuclear cells (PBMCs) and polymorphonuclear cells (PMNs) express markers that configure an anti-inflammatory response. However, PMNs response is more sensitive to the effects of IFNT. PMNs are more likely to express interferon-stimulated genes (ISGs), transforming growth factor-beta (TGFB), interleukin 10 (IL10), and arginase-1 (ARG1), configuring one of the most rapid immune responses to early pregnancy. This review focus on the local and peripheral immune responses during early pregnancy in ruminants, mainly the PMNs function in the immune system.

Heat stress modulates polymorphonuclear cell response in early pregnancy cows: I. interferon pathway and oxidative stress

One of the major causes of early pregnancy loss is heat stress. In ruminants, interferon tau (IFNT) is the embryo signal to the mother. Once the interferon signaling pathway is activated, it drives gene expression for interferon-stimulated genes (ISGs) and alters neutrophils responses. The aim of the present study was to evaluate interferon (IFN) pathway, ISGs and gene expression in polymorphonuclear leukocytes (PMN) and oxidative stress in dairy cows under heat stress. Pregnant cows had their estrous cycle synchronized and randomly assigned to a comfort or heat stress group. Blood samples were collected at artificial insemination (AI) and on Days 10, 14 and 18 following AI. Pregnant cows were pregnancy checked by ultrasound on Day 30 and confirmed on Day 60 post-AI. Results are presented as mean ± SEM. The corpus luteum (CL) diameter was not different between groups of pregnant cows; concentration of progesterone of pregnant cows on Day 18 following AI was greater in comfort group compared to heat stressed group. Comfort pregnant cows had higher expression of all analyzed genes from interferon pathway, except for IFNAR1, on both Days 14 and 18. Conversely, heat stressed cows did not show altered expression of IFNT pathway genes and ISGs between Days 10, 14, and 18 after AI. The oxidative stress, determined as malondialdehyde (MDA) levels, was greater in heat stress group on Days 10, 14 and 18, independent of pregnancy status. Heat stress negatively influences expression of ISGs, IFN pathway gene expression in neutrophils, and oxidative stress. Our data suggest that lower conception rates in cows under heat stress are multifactorial, with the association of interferon pathway activation and the unbalanced oxidative stress being main contributing factors.

Ovariectomy Improves Metabolic and Oxidative Stress Marker Disruption in Androgenized Rats: Possible Approach to Postmenopausal Polycystic Ovary Syndrome

Background: This study aims to evaluate metabolic and oxidative stress markers in a postmenopausal rat model of polycystic ovary syndrome (PCOS). Methods: Wistar rats were divided in four groups: control ovariectomized (OVX; n = 9), control SHAM (n = 9), androgenized OVX (n = 10), and androgenized SHAM (n = 10). Female rats were androgenized during the neonatal period and compared with controls. Surgery (ovariectomy or SHAM procedure) was performed at day 100 and euthanasia at day 180 of life. Bodyweight, lipids, glucose, triglyceride glucose (TyG) index, and oxidative stress markers (total oxidant status [TOS], total antioxidant capacity, nitric oxide, ferric-reducing ability of plasma [FRAP], and advanced oxidation protein product) were addressed. Results: Androgenized SHAM rats exhibited a higher total, low-density lipoprotein cholesterol, triglycerides, TyG index (an insulin resistance marker), and increased TOS, FRAP, and albumin in comparison with control SHAM rats. These abnormalities disappeared after ovariectomy despite the fact that ovariectomized androgenized rats became heavier than the other three groups. Conclusion: Ovariectomy improved metabolic and oxidative stress markers in a rat model of PCOS.

Trabecular Bone is Increased in a Rat Model of Polycystic Ovary Syndrome

Polycystic ovary syndrome (PCOS) in an intricate disorder characterized by reproductive and metabolic abnormalities that may affect bone quality and strength along with the lifespan. The present study analysed the impact of postnatal androgenization (of a single dose of testosterone propionate 1.25 mg subcutaneously at day 5 of life) on bone development and markers of bone metabolism in adult female Wistar rats. Compared with healthy controls, the results of measurements of micro-computed tomography (microCT) of the distal femur of androgenized rats indicated an increased cortical bone volume voxel bone volume to total volume (VOX BV/TV) and higher trabecular number (Tb.n) with reduced trabecular separation (Tb.sp). A large magnitude effect size was observed in the levels of circulating bone formation Procollagen I N-terminal propeptide (P1NP) at day 60 of life; reabsorption cross-linked C-telopeptide of type I collagen (CTX) markers were similar between the androgenized and control rats at days 60 and 110 of life. The analysis of gene expression in bone indicated elements for an increased bone mass such as the reduction of the Dickkopf-1 factor (Dkk1) a negative regulator of osteoblast differentiation (bone formation) and the reduction of Interleukin 1-b (Il1b), an activator of osteoclast differentiation (bone reabsorption). Results from this study highlight the possible role of the developmental programming on bone microarchitecture with reference to young women with PCOS.

Transforming growth factor-beta family members are regulated during induced luteolysis in cattle

The transforming growth factors beta (TGFβ) are local factors produced by ovarian cells which, after binding to their receptors, regulate follicular deviation and ovulation. However, their regulation and function during corpus luteum (CL) regression has been poorly investigated. The present study evaluated the mRNA regulation of some TGFβ family ligands and their receptors in the bovine CL during induced luteolysis in vivo. On day 10 of the estrous cycle, cows received an injection of prostaglandin F2α (PGF) and luteal samples were obtained from separate groups of cows (n= 4-5 cows per time-point) at 0, 2, 12, 24 or 48 h after treatment. Since TGF beta family comprises more than 30 ligands, we focused in some candidates genes such as activin receptors (ACVR-1A, -1B, -2A, -2B) AMH, AMHR2, BMPs (BMP-1, -2, -3, -4, -6 and -7), BMP receptors (BMPR-1A, -1B and -2), inhibin subunits (INH-A, -BA, -BB) and betaglycan (TGFBR3). The mRNA levels of BMP4, BMP6 and INHBA were higher at 2 h after PGF administration (P<0.05) in comparison to 0 h. The relative mRNA abundance of BMP1, BMP2, BMP3, BMP4, BMP6, ACVR1B, INHBA and INHBB was upregulated up to 12 h post PGF (P<0.05). On the other hand, TGFBR3 mRNA that codes for a reservoir of ligands that bind to TGF-beta receptors, was lower at 48 h. In conclusion, findings from this study demonstrated that genes encoding several TGFβ family members are expressed in a time-specific manner after PGF administration.

Viability of Equine Chondrocytes After Exposure to Mepivacaine and Ropivacaine In Vitro

Chondrocyte health is altered when exposed to local anesthetics, raising concerns as to the long-term effects of local anesthetics intra-articularly for diagnosis and analgesia. To investigate the drug with the lowest toxic potential, the effect of ropivacaine and mepivacaine on chondrocytes was evaluated. Articular cartilage from normal metacarpophalangeal joints of five equine cadaver specimens was used to establish chondrocyte cultures. Following seven days, chondrocytes were exposed to standard culture medium (DMEM), ropivacaine 7.5 mg/ml (ROP7.5), ropivacaine 10 mg/ml (ROP10), mepivacaine 20 mg/ml (MEP20), mepivacaine 30 mg/ml (MEP 30), and 0.9% saline solution (SAL). Chondrocyte viability was evaluated by trypan blue exclusion, MTT, and flow cytometry via cellular staining with propidium iodide. No differences were observed between treatments following trypan blue exclusion assay. A difference was observed between DMEM and all other treatment groups (P < .0001) with a significant viability drop using the MTT assay. Mepivacaine 20 mg/ml and MEP30 exposure between showed greatest decrease in cellular viability compared to SAL, ROP7.5, and ROP10 (P < .0001). Cellular viability decreased as measured by flow cytometry in all groups compared to DMEM and ROP7.5 (P < .02). Interestingly, the trypan blue, MTT, and flow cytometry assays yielded different results. Although there was no difference using trypan blue, MTT demonstrated that ropivacaine-treated cells had lower viability than DMEM, and cytometry found that ROP7.5 did not differ from DMEM. Results in vitro suggest that short-term exposure to ropivacaine may result in less chondrotoxicity than mepivacaine. In vivo studies are warranted investigating long-term effects of local anesthetics on equine articular cartilage.

Oxidative stress and biochemical markers in prenatally androgenized sheep after neonatal treatment with GnRH agonist

Background

Disruption of the balance between the production of ROS and their removal through enzymatic and non-enzymatic (antioxidant) processes has been proposed as a new mechanism in the pathology of polycystic ovary syndrome (PCOS). Evidence from animal models of PCOS (prenatally androgenized sheep) has suggested that treatment with insulin sensitizers, but not antiandrogens, can reduce increases in ROS.

Materials and methods

In the present study, we investigated the effects of neonatal treatment with a gonadotropin-releasing hormone (GnRH) agonist (leuprolide acetate) on prenatally androgenized sheep with testosterone propionate to determine its impact on oxidative stress molecules (ferric reducing antioxidant power [FRAP], advanced oxidation protein product [AOPP], nitric oxide [NOx], albumin) at 8, 12, and 18 months of age.

Results

Androgenized ewes (but not leuprolide-treated ewes) showed reduced total cholesterol levels associated with a decrease in the ratio of visceral to subcutaneous adiposity (adjusted to abdominal area) as determined by computed tomography. In androgenized ewes at 12 months of age, an increase in subcutaneous fat and relative decrease in the visceral fat compartment did not affect the expression of REDOX markers. At 18 months of age, however, the levels of NOx metabolites decreased in androgenized animals, but remained close to normal in ewes subjected to neonatal treatment with leuprolide acetate. Other oxidative stress parameters (FRAP, AOPP, albumin) did not vary among groups.

Conclusion

Our results demonstrate that the GnRH agonist leuprolide (as a single dose after birth) had weak effects on markers of the oxidative stress balance.

Prenatal Androgenization of Ewes as a Model of Hirsutism in Polycystic Ovary Syndrome

The main clinical feature associated with hyperandrogenism in polycystic ovary syndrome (PCOS) in humans is hirsutism, where hair increases its length, pigmentation, and particularly its diameter. Currently, it is not known whether PCOS animal models also exhibit changes in the hair. Therefore, the aim of this study was to explore the wool characteristics in sheep prenatally androgenized (PA) with testosterone propionate. After 4 and 13 months of life, wool was collected from the top of the shoulder of both females and males (both androgenized and controls). The offspring sheep were followed for up to 19 months of life to evaluate testosterone and androstenedione serum levels by ultra-high-performance liquid chromatography-tandem mass spectrometry, determine insulin and glucose response to intravenous glucose tolerance test, and address estrus cyclicity during the second breeding season. PA male animals showed a reduction in wool fiber diameter at 4 months of age compared with controls (P = 0.02) but not at 13 months, whereas PA females showed increased hair diameter at 13 months (P = 0.002), with no difference at 4 months. No substantial changes in other hair parameters (length, color, and medullation) were identified. In addition, increased levels of serum testosterone were observed in PA female sheep compared with controls at 12 months (P = 0.03). Our results indicate for the first time, to our knowledge, that changes in wool fiber diameter observed in PA ewes replicate, at the translational level, the increase in hair diameter in hirsute women with PCOS.

Oxidative stress and metabolic markers in pre- and postnatal polycystic ovary syndrome rat protocols

Background

Several studies have described an enhanced inflammatory status and oxidative stress balance disruption in women with polycystic ovary syndrome (PCOS). However, there is scarce information about redox markers in the blood of androgenized animal models. Here, we evaluated the serum/plasma oxidative stress marker and metabolic parameter characteristics of prenatal (PreN) and postnatal (PostN) androgenized rat models of PCOS.

Materials and methods

For PreN androgenization (n=8), 2.5 mg of testosterone propionate was subcutaneously administered to dams at embryonic days 16, 17, and 18, whereas PostN androgenization (n=7) was accomplished by subcutaneously injecting 1.25 mg of testosterone propionate to animals at PostN day 5. A unique control group (n=8) was constituted for comparison.

Results

Our results indicate that PostN group rats exhibited particular modifications in the oxidative stress marker, an increased plasma ferric-reducing ability of plasma, and an increased antioxidant capacity reflected by higher albumin serum levels. PostN animals also presented increased total cholesterol and triglyceride-glucose levels, suggesting severe metabolic disarrangement.

Conclusion

Study findings indicate that changes in oxidative stress could be promoted by testosterone propionate exposure after birth, which is likely associated with anovulation and/or lipid disarrangement.

The impact of postnatal leuprolide acetate treatment on reproductive characteristics in a rodent model of polycystic ovary syndrome

In this study, a GnRH agonist, leuprolide acetate (LA), was given as a single depot injection before 48 h of life to Wistar female rats allotted to prenatal (E16-18) and postnatal androgenization (day 5 of life) by the use of testosterone propionate, looking for reproductive endpoints. Remarkably, a single injection of LA increased the estrus cycles in the postnatal group (PostN) from 0% to 25% of the estrus cycles in the postnatal LA treated group (PostN L). LA also reduced the serum testosterone levels and cysts and atretic follicles in PostN L in contrast with rats (>100 days) from the PostN group (p = 0.04). Prenatally androgenized rats (PreN) exhibited significant modifications in the hypothalamic genes, such as Gnrh. To the best of our knowledge, this is the first study to show that blockage of the GnRH axis with leuprolide acetate depot prevented the development of typical features (anovulation, cysts, atretic follicles) in a postnatal testosterone propionate rat model of PCOS.

Lack of FSH support enhances LIF-STAT3 signaling in granulosa cells of atretic follicles in cattle

Subordinate follicles (SFs) of bovine follicular waves undergo atresia due to declining FSH concentrations; however, the signalling mechanisms have not been fully deciphered. We used an FSH-induced co-dominance model to determine the effect of FSH on signalling pathways in granulosa cells of the second-largest follicles (SF in control cows and co-dominant follicle (co-DF2) in FSH-treated cows). The SF was smaller than DF in control cows while diameters of co-DF1 and co-DF2 in FSH-treated cows were similar. The presence of cleaved CASP3 protein confirmed that granulosa cells of SFs, but not of DFs and co-DFs, were apoptotic. To determine the effect of FSH on molecular characteristics of the second-largest follicles, we generated relative variables for the second largest follicle in each cow. For this, variables of SF or co-DF2 were divided by the variables of the largest follicle DF or co-DF1 in each cow. There was higher transcript abundance of MAPK1/3 and AKT1/2/3 but lower abundance of phosphorylated MAPK3/1 in SF than co-DF2 granulosa cells. Abundance of mRNA and phosphorylated protein of STAT3 was higher in granulosa cells of control SF than FSH-treated co-DF2. SF granulosa cells had higher levels of LIFR and IL6ST transcripts, the two receptors involved in STAT3 activation. Further, lower transcript abundance of interleukin 6 receptor (IL6R), another receptor involved in STAT3 activation, indicated that STAT3 activation in SF granulosa cells could be mainly due to leukemia inhibitory factor (LIF) signalling. These results indicate that atresia due to lack of FSH is associated with activated LIF-STAT3 signalling in SF granulosa cells, as FSH treatment reversed such activation.

Responsivity to PGE2 labor induction involves concomitant differential prostaglandin E receptor gene expression in cervix and myometrium

Prostaglandin E2 (dinoprostone) is largely used for labor induction. However, one-third of patients do not respond to treatment. One cause of this poor response may be associated with changes in regulation of prostaglandin E receptors (EP1-4). In this study, we investigated EP mRNA expression in the uterine cervix and lower uterine segment myometrium for term births. Biopsies were obtained from women with successful (responders) and failed (non-responders) dinoprostone labor induction, while women that underwent spontaneous labor were included as controls. EP1 mRNA was upregulated in the cervical tissue of women who did not respond to dinoprostone induction. In addition, in the myometrium, significantly higher levels of EP3 mRNA were observed in women treated with dinoprostone, independent of their responsiveness. Dinoprostone-responders presented 3.6-fold higher levels of EP3 mRNA expression than the spontaneous labor group. Significantly higher levels of EP3 mRNA in the myometrium of the dinoprostone-treated group indicated that dinoprostone may regulate the EP3 gene on the transcriptional level. These results highlight the relationship between EP gene expression and delivery and indicate that understanding the regulation of prostaglandin E receptors may lead to improved labor induction.