Research progress in rodent models of endometriosis

Endometriosis is a common and frequent disease in gynecology; its etiology and pathogenesis are partially understood and still not clear. The construction of suitable animal models is beneficial for basic research related to the disease. Currently, rodents have the advantages of low cost, fast reproduction, easy rearing, and a similar endometrial structure to humans. Depending on the purpose of the experiment, different molding methods have their advantages. In this paper, we describe the traditional methods of constructing endometriosis rodent models, compare their advantages and disadvantages, and introduce newly developed rodent models, such as cell line injection models, pain models, genetically engineered mouse models, fluorescent tracer models, iron overload models, chemical induction models, and methods of constructing rodent models of different subtypes of endometriosis. Fertility and treatment of endometriosis rodent models are also described. This study provides a reference for researchers in the selection of animal models for pathogenesis and drug treatment studies.

Impact of oil-based contrast agents in hysterosalpingography on fertility outcomes in endometriosis: a retrospective cohort study

BACKGROUND

Previous studies have suggested that oil-based contrast agents used during hysterosalpingography (HSG) in infertile patients can enhance fertility. However, limited research has investigated the effect of oil-based contrast medium specifically in individuals with endometriosis-related infertility.

OBJECTIVE

This study aims to explore the impact of oil-based contrast medium on fertility outcomes in women with endometriosis-related infertility.

METHODS

Conducted at the First Affiliated Hospital of Guangxi Medical University (January 2020 to June 2022), the study included 512 patients undergoing HSG. Patients were categorized into oil-based and non-oil-based groups, and after propensity score matching, demographic characteristics were compared. Main outcomes included clinical pregnancy rates, live birth rates, early miscarriage rates, and ectopic pregnancy rates.

RESULTS

In our analysis, the Oil-based group showed significantly better outcomes compared to the Non-oil-based group. Specifically, the Oil-based group had higher clinical pregnancy rates (51.39% vs. 27.36%) and increased live birth rates (31.48% vs. 19.93%). This trend held true for expectant treatment, IUI, and IVF/ICSI, except for surgical treatment where no significant difference was observed. After adjusting for various factors using propensity score matching, the Non-oil-based group consistently exhibited lower clinical pregnancy rates compared to the Oil-based group. The Odds Ratio (OR) was 0.38 (95%CI: 0.27-0.55) without adjustment, 0.34 (0.22-0.51) in multivariable analysis, 0.39 (0.27-0.57) using inverse probability of treatment weighting (IPTW), and 0.22 (0.14-0.35) in propensity score matching.

CONCLUSION

Oil-based contrast medium used in HSG for women with endometriosis-related infertility is associated with higher clinical pregnancy rates and live birth rates compared to Non-oil-based contrast medium.

Association between vitamin D and endometriosis among American women: National Health and Nutrition Examination Survey

Endometriosis is a multifactorial disease associated with inflammation. Vitamin D has anti-inflammatory, antiproliferative, anti-oxidative, and immunomodulatory effects. Whether vitamin D levels are correlated with endometriosis is a subject of ongoing debate. This study aimed to examine the association between endometriosis and serum vitamin D levels. From the National Health and Nutrition Examination Survey, this study examined the cross-sectional data of American women aged 20-54 years from 2001 to 2006. After adjusting for covariates, multivariable logistic regression analysis was used to assess correlations. A total of 3,232 women were included in this study. The multiple linear regression model demonstrated a negative correlation between the serum 25-hydroxyvitamin D3 (cholecalciferol) concentration and the risk of endometriosis after controlling for all confounding variables. The odds ratio was 0.73 with a 95% confidence interval of 0.54-0.97 in the adequate vitamin D level group compared with the insufficient vitamin D level group. Our results showed that endometriosis was inversely correlated with serum 25-hydroxyvitamin D3 levels. Further research is needed to establish a causal relationship and determine the potential benefits of maintaining sufficient vitamin D levels for endometriosis prevention.

Assessing the impact of transplant site on ovarian tissue transplantation: a single-arm meta-analysis

BACKGROUND

Survival rates of young women undergoing cancer treatment have substantially improved, with a focus on post-treatment quality of life. Ovarian tissue transplantation (OTT) is a viable option to preserve fertility; however, there is no consensus on the optimal transplantation site. Most studies on OTT are nonrandomized controlled trials with limited sample sizes and uncontrolled statistical analyses, leaving the question of which transplant site yields the highest chance of achieving a live birth unanswered.

OBJECTIVE

This meta-analysis aimed to assess the effect of different ovarian transplant sites on postoperative reproductive outcomes.

METHODS

We adhered to the PRISMA Reporting Items for Systematic Reviews and Meta-Analyses recommendations. Systematic searches were conducted in PubMed, Embase, Web of Science, and the Cochrane Library from inception to September 17, 2023. The inclusion criteria were as follows: (1) women who underwent OTT with a desire for future childbirth, and (2) reports of specific transplant sites and corresponding pregnancy outcomes. The exclusion criteria included the inability to isolate or extract relevant outcome data, case reports, non-original or duplicate data, and articles not written in English.

RESULTS

Twelve studies (201 women) were included in the meta-analysis of cumulative live birth rates (CLBR) after OTT. The CLBR, which encompasses both spontaneous pregnancies and those achieved through assisted reproductive technology (ART) following OTT to the ovarian site, was 21% (95% CI: 6-40, I2: 52.81%, random effect). For transplantation to the pelvic site, the live birth rate was 30% (95% CI: 20-40, I2: 0.00%, fixed effect). Combining transplantation to both the pelvic and ovarian sites resulted in a live birth rate of 23% (95% CI: 11-36, I2: 0.00%, fixed effect). Notably, heterotopic OTT yielded a live birth rate of 3% (95% CI: 0-17, I2: 0.00%, fixed effect).

CONCLUSION

Pregnancy outcomes were not significantly different after orthotopic ovarian transplantation, and pregnancy and live birth rates after orthotopic OTT were significantly higher than those after ectopic transplantation.

REGISTRATION NUMBER

INPLASY202390008.

Aquaporin 9 causes recurrent spontaneous abortion by inhibiting trophoblast cell epithelial-mesenchymal transformation and invasion through the PI3K/AKT pathway†

BACKGROUND

Invasion of the endometrium by trophoblast cells is a key event during pregnancy, although the underlying mechanism remains unclear. Aquaporin 9 (AQP 9) is expressed in many eukaryotes and is associated with cell invasion. The objective of this study was to evaluate the significance of AQP9 in recurrent spontaneous abortion.

METHODS

We screened the GSE22490 dataset and further differentiated aquaporin 9 expression in villi. AQP9 was evaluated as one of the key factors in abortion by injecting AQP9 overexpressed plasmid into the uterus of CD1 mice. Trophoblast cells were transfected with AQP9-overexpressing plasmid or siAQP9 to measure cell proliferation, migration, invasion, and apoptosis. Western blot was used to measure changes in the expression of invasion, epithelial-mesenchymal transformation process, and PI3K/AKT pathway. Finally, the role of AQP9 in PI3K/AKT signaling pathway was determined using the PI3K/AKT inhibitor, LY294002, and activator, 740Y-P.

RESULTS

AQP9 is highly expressed in recurrent spontaneous abortion villus. Intrauterine injections of AQP9-overexpressing plasmid into CD1 mice resulted in atrophy and blackness of the gestational sac and increased the absorption rate, it is the causative factor of abortion. AQP9 upregulation inhibited the proliferation, invasion, migration, and epithelial-mesenchymal transformation process in vitro of trophoblast cells and increased cell apoptosis. The opposite result was observed after silencing AQP9. AQP9 overexpression also inhibited the PI3K/AKT pathway. LY294002 and 740Y-P partially recovered AQP9-induced trophoblast invasion and migration via the PI3K/AKT pathway.

CONCLUSIONS

AQP9 reduces the invasive ability of trophoblast cells by regulating PI3K/AKT signaling pathway, participating in recurrent spontaneous abortion.

Combined oral antibiotics and intrauterine perfusion can improve in vitro fertilization and embryo transfer pregnancy outcomes in patients with chronic endometritis and repeated embryo implantation failure

BACKGROUND

The aim of this retrospective study was to investigate whether oral antibiotics (doxycycline and metronidazole) combined with intrauterine perfusion (gentamicin and dexamethasone) are beneficial for patients with repeated implantation failure (RIF) and chronic endometritis (CE) to improve clinical pregnancy outcomes.

METHODS

Patients with RIF and CE were diagnosed using hysteroscopy and histology together. A total of 42 patients were enrolled in the study. All patients received oral antibiotics (doxycycline combined with metronidazole) and 22 patients underwent intrauterine perfusion (gentamicin combined with dexamethasone) immediately after the end of oral antibiotic therapy. Pregnancy outcomes were evaluated during the first in vitro fertilization (IVF) and embryo transfer (ET) cycle.

RESULTS

For the first D3 ET after treatment with oral antibiotics (doxycycline and metronidazole) combined with intrauterine perfusion (gentamicin and dexamethasone), higher embryo implantation rate (30.95% vs. 26.67%, P = 0.0308), clinical pregnancy rate (30% vs. 50%, P < 0.001), live birth rate (33.33% vs. 45.45%, P < 0.0001). No fetal malformations or ectopic pregnancies were observed.

CONCLUSION

We report oral antibiotics (doxycycline and metronidazole) combined with intrauterine perfusion (gentamicin and dexamethasone) as a novel treatment for CE to improve the outcomes of successful pregnancy compared with those of oral antibiotics alone.

Impaired hypocretin/orexin system alters responses to salient stimuli in obese male mice

The brain has evolved in an environment where food sources are scarce, and foraging for food is one of the major challenges for survival of the individual and species. Basic and clinical studies show that obesity or overnutrition leads to overwhelming changes in the brain in animals and humans. However, the exact mechanisms underlying the consequences of excessive energy intake are not well understood. Neurons expressing the neuropeptide hypocretin/orexin (Hcrt) in the lateral/perifonical hypothalamus (LH) are critical for homeostatic regulation, reward seeking, stress response, and cognitive functions. In this study, we examined adaptations in Hcrt cells regulating behavioral responses to salient stimuli in diet-induced obese mice. Our results demonstrated changes in primary cilia, synaptic transmission and plasticity, cellular responses to neurotransmitters necessary for reward seeking, and stress responses in Hcrt neurons from obese mice. Activities of neuronal networks in the LH and hippocampus were impaired as a result of decreased hypocretinergic function. The weakened Hcrt system decreased reward seeking while altering responses to acute stress (stress-coping strategy), which were reversed by selectively activating Hcrt cells with chemogenetics. Taken together, our data suggest that a deficiency in Hcrt signaling may be a common cause of behavioral changes (such as lowered arousal, weakened reward seeking, and altered stress response) in obese animals.

Women with recurrent spontaneous abortion have decreased 25(OH) vitamin D and VDR at the fetal-maternal interface

Immunological mechanisms have been proposed to underlie the pathogenesis of recurrent spontaneous abortion (RSA). Vitamin D has a potent immunomodulatory effect, which may affect pregnancy outcome. The objective of this study was to investigate 25-hydroxyvitamin D [25(OH) D] concentration and vitamin D receptor (VDR) expression in the decidual tissues of RSA patients. Thirty women with RSA (RSA group) and thirty women undergoing elective abortion (control group) were recruited during 2016 from gynecology outpatient clinics. We measured 25(OH) D, interleukin (IL)-17, IL-23, transforming growth factor β (TGF-β), VDR and 1-α-hydroxylase (CYP27B1) in decidual tissues collected during the abortion procedure. In the RSA group, 25(OH) D and TGF-β were significantly decreased while IL-17 and IL-23 were significantly increased compared with the control group. VDR expression was significantly decreased in the RSA group compared with the control group. Logistic regression analysis showed a significant negative correlation between 25(OH) D in decidual tissues and RSA. These results indicated that vitamin D concentrations in the decidua are associated with inflammatory cytokine production, suggesting that vitamin D and VDR may play a role in the etiology of RSA.

Screening of adjunct cultures and their application in ester formation in Camembert-type cheese

The ethanol content and esterase and alcohol acyltransferase activities are the limiting factors in the synthesis of ethyl esters in Camembert-type cheeses. This study aimed to investigate the effects of alcohol, esterase and alcohol acyltransferase activities on ethyl ester formation in Camembert-type cheeses. Five experimental cheeses were prepared with three adjunct cultures with different enzyme activities and two levels of ethanol content (400 or 800 μg/g). The cheeses were aged for 4 weeks and analysed weekly for basic physicochemical, textural, volatile and sensory properties. The results showed that both the enzyme activity and ethanol content were limiting factors in the synthesis of ethyl esters in the Camembert-type cheeses. Variation in the esterase synthesis activity was observed among lactic acid bacteria, and the starter culture Lactococcus lactis MA 14 LYO distinguished itself through its high acidifying and esterase hydrolysis abilities. The addition of CCFM 12, a lactic acid bacteria strain with high esterase and alcohol acyltransferase activity, along with 400 or 800 μg/g of ethanol, notably enhanced the generation of ethyl esters and the corresponding fruity flavour, without causing dramatic changes in the basic physicochemical indices and microbial profile. In addition, cohesiveness was influenced by the addition of 400 and 800 μg/g of ethanol, and more resilience with 800 μg/g of ethanol had been found. The results showed that the addition of CCFM12 with 400 and 800 μg/g of ethanol may be applied in the production of Camembert cheese to enhance its fruity flavour.

[Results of requesting a second consecutive sperm ejaculate on the day of oocyte pick-up in assisted reproductive technology]

OBJECTIVE

To evaluate the results of requesting a second consecutive sperm ejaculate in order to reduce ICSI cycles by PESA or TESE on the day of oocyte pick-up in assisted reproductive technology (ART).

METHODS

We collected 68 semen samples as a second consecutive ejaculate from 34 men, compared the semen volume and sperm concentration, motility and total count between the first and the second ejaculation, and analyzed the laboratory results and clinical outcomes of fertilization with the mixed sperm.

RESULTS

The 34 males ejaculated twice within 4 hours by masturbation, with an interval of 26-183 (94.9 +/- 39.8) minutes between the first and second ejaculation. The volume of the first ejaculate was (2.0 +/- 1.4) ml, significantly higher than that of the second ([1.5 +/- 0.9] ml) (P = 0.007), although the numbers of motile sperm and grade a + b sperm of the first ([40.8 +/- 25.3]% and [30.9 +/- 22.4]%) were significantly lower than those of the second ([52.2 +/- 21.1]% and [39.9 +/- 17.5]%) (P < 0.05). There were no statistically significant differences in the sperm concentration or total sperm count between the two ejaculates (P > 0.05). The ICSI, IVF + ICSI, and IVF cycles were 3, 3 and 28 respectively among the 34 couples undergoing ART. The number of retrieved oocytes, normal fertilization rate, high quality embryo rate and frozen cycles/fresh transfer cycles ratio were 15.5 +/- 8.7, 57.0% (247/433), 58.7% (145/247) and 20/24 for the IVF cycle, 21.7 +/- 8.3, 61.5% (40/65), 67.5% (27/40) and 3/2 for the ICSI cycle, and 10.0 +/- 2.6, 72.4% (21/29), 66.7% (14/21) and 3/3 for the IVF + ICSI cycle. Fourteen live births were achieved out of the 18 pregnancies, including 6 healthy boys and 9 healthy girls.

CONCLUSION

A clinical pregnancy rate of >30% can be achieved by requesting a second consecutive sperm ejaculate on the day of oocyte pick-up in order to collect more sperm and/or increase the total number of motile sperm for ART. And this method can avoid other invasive sperm processing techniques and the need of unnecessary micromanipulative fertilization.