Proliferative and apoptotic changes in the healthy canine endometrium and in cystic endometrial hyperplasia

Identification and analysis of oxidative stress-related genes in endometriosis

Background

Early diagnosis and treatment of endometriosis (EM) remain challenging because of the lack of knowledge about EM development. While oxidative stress (OS) has been associated with EM, the link is unclear. We explored OS-related genes (OSRGs) and their role in EM pathogenesis.

Material and methods

We combined two ectopic endometrium (EC) and eutopic endometrium (EU) datasets (GSE11691 and GSE25628) into a dataset for analysis. Bioinformatic analyses were used to identify differentially expressed genes (DEGs), OS-related genes (OSRGs), enriched pathways, competitive endogenous RNA network, and immune cell infiltration. Finally, real time-quantitative polymerase chain reaction (RT-qPCR) and Western blot (WB) were used to validate the expression of key OSRGs in clinical patient samples.

Results

Bioinformatic analysis identified 459 DEGs between EC and EU samples, including 67 OSRGs. A ceRNA network was established, encompassing 28 DE-OSRGs, 32 miRNAs, and 53 lncRNAs. Four key OSRGs (CYP17A1, NR3C1, ENO2, and NGF) were selected from protein-protein interaction network analysis. The RT-qPCR and WB analysis showed that these genes' abnormal changes in RNA and protein levels were consistent with data in public databases. Weighted gene co-expression network analysis identified three immune-related OSRGs (CYP17A1, NR3C1, and NGF) and 20 lncRNAs that may regulate NR3C1 through 10 miRNAs.

Conclusion

The key OSRGs may function via multilayered networks in EM. We provide insights into EM and underscore the potential significance of OSRGs and the immune environment for diagnostic and prognosis evaluation.

Predisposing Factors for Pseudoplacentational Endometrial Hyperplasia or Cystic Endometrial Hyperplasia in Dogs and Their Association with Pyometra

Pseudoplacentational endometrial hyperplasia (PEH) and cystic endometrial hyperplasia (CEH) are both hyperplastic conditions that may occur in the canine uterus during diestrus. CEH can impair fertility, and, although the consequences of PEH are poorly known, this condition is significantly associated with pyometra. The aim of this study was to investigate frequencies of both PEH and CEH in female dogs according to age, size, breed, and breed group. Uteri from 300 female dogs were sampled and processed for histopathologic analyses. Lesions were identified, and frequencies were statistically compared. PEH was significantly more frequent in dogs between 4 and 12 years of age and significantly less frequent in Yorkshires than Shih-tzus, as well as in the breed group that includes Brazilian Terriers and Yorkshires. CEH was significantly more frequent in dogs older than 12 years, but no breed predisposition was observed. The frequency of PEH was significantly higher than that of CEH. The frequency of pyometra in PEH cases was significantly higher than endometritis or uterus without inflammation. This study identified age, breed group, and size as predisposing factors for PEH and further demonstrated the association between this condition and pyometra in dogs.

Proliferation and apoptosis studies of interplacental areas after aglepristone treatment for planned cesarean section in pregnant bitches

Background and Aim

Progesterone (P4) is the main hormone for pregnancy maintenance, occurring approximately 62-64 days after ovulation in bitches. Progesterone acts by binding to specific receptors. Aglepristone is a progesterone receptor (PR) antagonist with a higher affinity for PR binding. There are no published studies on cell proliferation and apoptosis in the canine uterus at the time of parturition. Therefore, this study aimed to determine the local effects of aglepristone on cell proliferation and apoptosis of interplacental uterine tissue during planned cesarean section (C-section) in bitches.

Materials and Methods

In this study, 13 client-owned French bulldogs were examined. Bitches were divided into treatment (n = 8) and control (n = 5) groups. Ovulation timing was predicted based on the serum P4 level on 62-64 days post-ovulation for parturition. Serum P4 levels were measured before (on 60-day post-ovulation) and on C-section day (on 61-day post-ovulation). Aglepristone (Alizine®), 15 mg/kg subcutaneously (SC), was administered on 60 days post-ovulation in the treatment group. A C-section was planned 20-24 h later, and interplacental uterine areas were collected from both groups during the C-section. Immunohistochemistry based on Ki-67 and TUNEL assay was used to evaluate cell proliferation and apoptosis in four different interplacental uterine tissue layers (epithelium, stroma, glandular epithelium, and myometrium). Data are reported as mean ± standard deviation. Kruskal-Wallis test was used for comparisons of more than two independent groups. P value of 0.05 was considered statistically significant.

Results

One bitch in the treatment group was excluded due to emergency C-section 8 h after aglepristone administration. Serum P4 levels (ng/mL) at 20-24 h before and at C-section were 6.09 ± 2.72 and 4.32 ± 2.2 in the treatment group (n = 7) and 5.45 ± 1.28 and 3.67 ± 1.89 in the control group (n = 5), respectively. Proliferation (PI) and apoptotic (AI) indices were <5% and >45%, respectively, in both the treatment (n = 5) and control (n = 3) groups. PI and AI were detected at interplacental areas.

Conclusion

There were no significant differences in serum P4 levels or PI and AI indices between the groups. The PI <5% and AI was higher than 45% in both groups. Aglepristone did not have a direct effect on the serum P4 levels in both groups. These results correlated with the natural physiology of parturition preparation. Aglepristone 15 mg/kg SC injected 20-24 h before parturition had no effect on the P4 level, nor were any harmful effects observed for a planned C-section in pregnant bitches.

Pyometra in Small Animals 3.0

Pyometra is a common disease in intact bitches and queens and occurs, although less frequently, in most other female pets. In bitches and queens, the illness is generally diagnosed within 4 months after estrus, in middle-aged to older individuals. Complications such as peritonitis, endotoxemia, and systemic inflammatory response syndrome are not uncommon and associated with more severe illness. Ovary-sparing surgical options such as hysterectomy could be considered in individuals with high-risk for detrimental side effects of spaying or without infection of the uterus but has not yet been evaluated for safety in pyometra.

Endometrial hyperplasia and pyometra in captive lions (Panthera leo) and tigers (Panthera tigris)

Endometrial hyperplasia (EH) is a pathologic condition of the uterus with increased endometrial gland to stroma ratio compared to normal cyclic uterine proliferation. In domestic animals, EH often involves cystic distension of proliferating endometrial glands and may be concurrent with pyometra. In large captive nondomestic felids, an association between EH and pyometra is common; however, detailed species differences between the histological uterine findings in lions (Panthera leo) and tigers (Panthera tigris) and clinical manifestations have yet to be described. Uterine sections from 14 lions and 24 tigers with EH and/or pyometra were scored for several histological parameters and clinical histories were recorded. The percentage of endometrium affected by hyperplasia, endometrial gland to stroma ratio, and adenomyosis were significantly (P = .0385, P = .0008, and P = .0463, respectively) more severe in lions compared to tigers as univariate analytes. Although tubular complexity was not statistically significant (P = .3254), when combined as a proposed EH grading scheme, these 4 features confirmed lions had significantly (P = .0068) more severe EH compared to tigers. Endometrial hyperplasia severity significantly correlated with inflammation/pyometra severity when controlling for species (P = .0203). A significant correlation exists between pyometra-associated clinical sign severity and the presence of pyometra in tigers, (P = .0026) but not in lions (P = .1144). There was no statistical difference in the severity of clinical signs associated with pyometra between these species (P = .1986). This proposed grading scheme may have clinical utility in providing a more consistent and objective evaluation of EH in large captive felids.

Lipid droplet dynamics in healthy and pyometra-affected canine endometrium

BACKGROUND

Accumulation of lipid droplets (LDs) was recently observed in pyometra-affected uteri. As data about their nature and function are missing we intended to compare the localization, quality and quantity of LDs in canine healthy and pyometra-affected tissues and in an in vitro model.

METHODS AND RESULTS

We characterized LDs in healthy and pyometra uterine tissue samples as well as in canine endometrial epithelial cells (CEECs) in vitro by means of histochemistry, immunohistochemistry, transmission electron microscopy, western blot, and RT-qPCR. Oil Red O (ORO) staining and quantification as well as p-phenylenediamine staining showed a higher number of LDs in epithelial cells of pyometra samples. Immunohistochemistry revealed that the amount of LDs coated by perilipin2 (PLIN2) protein was also higher in pyometra samples. Transmission electron microscopy showed an increase of LD size in surface and glandular epithelial cells of pyometra samples. In cell culture experiments with CEECs, supplementation with oleic acid alone or in combination with cholesterol lead to an increased LD accumulation. The expression of PLIN2 at protein and mRNA level was also higher upon oleic acid supplementation. Most LDs were double positive for ORO and PLIN2. However, ORO positive LDs lacking PLIN2 coating or LDs positive for PLIN2 but containing a lipid class not detectable by ORO staining were identified.

CONCLUSIONS

We found differences in the healthy and pyometra-affected endometrium with respect to LDs size. Moreover, several kinds of LDs seem to be present in the canine endometrium. In vitro studies with CEECs could show their responsiveness to external lipids. Since epithelial cells reacted only to oleic acid stimulation, we assume that the cyclic lipid accumulation in the canine endometrium is based mainly on triglycerides and might serve as energy provision for the developing early embryo. Further studies are necessary to verify the complex role of lipids in the healthy and pyometra-affected canine endometrium.

The potential function of endometrial-secreted factors for endometrium remodeling during the estrous cycle

Uterine has a pivotal role in implantation and conceptus development. To prepare a conducive uterine condition for possibly new gestation during the estrous cycle, uterine endometrium undergoes dramatic remodeling. In addition, angiogenesis is an indispensable biological process of endometrium remodeling. Furthermore, essential protein expressions related to important biological processes of endometrium remodeling, which are vascular endothelial growth factor (VEGF), myoglobin (MYG), collagen type IV (COL4), fucosyltransferase IV (FUT4), and cysteine-rich protein 2 (CRP2), were detected in the endometrial tissue reported in many previous studies and recently discovered in histotroph substrates during the estrous cycle. Those proteins, which are liable for provoking new vessel development, cell proliferation, cell adhesion, and cell migration, were expressed higher in the histotroph during the luteal phase than follicular phase. Histotroph proteins considerably contribute to endometrium remodeling during the estrous cycle. To that end, the following review will discuss and highlight the relevant information and evidence of the uterine fluid proteins as endometrial-secreted factors that adequately indicate the potential role of the uterine secretions to be involved in the endometrial remodeling process.

Hypothyroidism induces uterine hyperplasia and inflammation related to sex hormone receptors expression in virgin rabbits

AIMS

In women, uterine alterations have been associated with sex steroid hormones. Sex hormones regulate the expression of thyroid hormone receptors (TRs) in the uterus, but an inverse link is unknown. We analyzed the impact of hypothyroidism on histological characteristics, vascular endothelial growth factor (VEGF-A), progesterone receptors (PR), estrogen receptors (ER), thyroid hormone receptors (TRs), perilipin (PLIN-A), and lipid content in the uterus of virgin rabbits.

MAIN METHODS

Twelve Chinchilla-breed adult female rabbits were grouped into control (n = 6) and hypothyroid (n = 6; 0.02% of methimazole for 30 days). The thickness of endometrium and myometrium, number of uterine glands, and infiltration of immune cells were analyzed. The expression of VEGF-A, PR, ERα, and PLIN-A was determined by RT-PCR and western blot. The uterine content of triglycerides (TAG), total cholesterol (TC), and malondialdehyde (MDA) was quantified.

KEY FINDINGS

Hypothyroidism promoted uterine hyperplasia and a high infiltration of immune cells into the endometrium, including macrophages CD163+. It also increased the expression of VEGF-A, TRA, and ERα-66 but reduced that of PR and ERα-46. The uterine content of PLIN-A, TAG, and TC was reduced, but that of MDA was augmented in hypothyroid rabbits.

SIGNIFICANCE

Our results suggest that uterine hyperplasia and inflammation promoted by hypothyroidism should be related to changes in the VEGF-A, PR, ER, and TRs expression, as well as to modifications in the PLIN-A expression, lipid content, and oxidative status. These results suggest that hypothyroidism should affect the fertility of females.

Chrysanthemum extract attenuates hepatotoxicity via inhibiting oxidative stress in vivo and in vitro

Background

‘Bianliang ziyu’, a famous chrysanthemum variety commonly planted in Kaifeng, China, is often consumed by local residents. However, the hepatoprotective effects of Bianliang ziyu and their underlying mechanisms are not clear.

Objective

In this study, we investigated the hepatoprotective and antioxidative effects of Bianliang ziyu extract (BZE) on liver injury and explored its molecular mechanisms.

Design

Sprague-Dawley rats were administered BZE by intragastric administration for 8–9 days, and then alcohol or carbon tetrachloride (CCl₄) was administered by gavage to induce acute liver injury. The activities of serum alanine aminotransferase, aspartate aminotransferase, superoxide dismutase, and malondialdehyde in the rats were measured, and the liver of each rat was examined for histopathological changes. In vitro, HL-7702 cells were pretreated with BZE for 24 h and then exposed to 30 mmol•L⁻¹ acetaminophen (APAP) for 12 h. The survival rate of the cells and the alanine aminotransferase and aspartate aminotransferase activities were determined. Then, we investigated the effects of BZE on oxidative stress, apoptosis, and the activation of nuclear factor erythroid-2-related factor 2 (Nrf2) signaling in HL-7702 cells induced by APAP.

Results

The results showed that BZE prevented alcohol-, CCl₄-, and APAP-induced liver injury and suppressed hepatic oxidative stress in vitro and in vivo. BZE was also observed to significantly inhibit the reduction of mitochondrial membrane potential and regulate the expression of Bcl-2, Bax and Caspase-3 in APAP-induced HL-7702 cells. In addition, BZE significantly promoted nuclear translocation and the expression of Nrf2 as well as its downstream gene hemeoxygenase-1 (HO-1) in vitro. Furthermore, the findings showed that Nrf2 siRNA reversed the effects of BZE on cell survival and apoptosis-related protein expression in APAP-induced HL-7702 cells.

Conclusions

BZE plays an important role in preventing hepatotoxicity by inhibiting oxidative stress and apoptosis through activation of Nrf2 signaling. BZE could be developed as an effective functional food for protecting the liver.