Impact of antibiotic treatment for chronic endometritis on unexplained recurrent pregnancy loss

Unveiling the protective effects of BMSCs/anti-miR-124-3p exosomes on LPS-induced endometrial injury

Researchers have reported that miR-124-3p is highly expressed in patients with chronic endometritis. However, the underlying mechanism of miR-124-3p in the development of endometritis remains unclear. This study constructed an in vitro endometrial cell injury model by treating HEECs with 2 μg/mL LPS for 48 h. Then, 1 mg/kg LPS was injected into both sides of the mouse uterus to construct an in vivo endometrial injury model. The expression of miR-124-3p in human endometrial epithelial cells (HEECs) was assessed using RT‒qPCR. Exosomes were separated from bone marrow-derived mesenchymal stem cells (BMSCs) and cocultured with HEECs. A dual-luciferase reporter assay was performed to confirm the relationship between miR-124-3p and DUSP6. The results indicated that LPS inhibited HEEC viability in a time- and dose-dependent manner. The miR-124-3p inhibitor reversed the LPS-induced apoptosis and inhibition of HEEC viability. In addition, miR-124-3p could be transferred from BMSCs to HEECs by exosomes. Exosomes were derived from BMSCs treated with an NC inhibitor (BMSCs/NC Exo) or miR-124-3p inhibitor (BMSCs/anti-miR-124-3p Exo). In addition, BMSCs/anti-miR-124-3p Exo abolished the LPS-induced inhibition of HEEC viability and proliferation by inducing HEEC apoptosis. Moreover, BMSCs/anti-miR-124-3p Exo alleviated the LPS-induced inflammation of HEECs by upregulating DUSP6 and downregulating p-p65 and p-ERK. Furthermore, in an LPS-induced in vivo endometrial injury model, BMSCs/anti-miR-124-3p Exo increased the expression level of DUSP6 and decreased the expression levels of p-p65 and p-ERK. BMSCs/anti-miR-124-3p Exo protected against LPS-induced endometrial damage in vitro and in vivo by upregulating DUSP6 and downregulating p-p65 and p-ERK1/2. This study showed that BMSCs/anti-miR-124-3p Exo might be a potential alternative for the treatment of endometritis.

Antibiotic cured chronic endometritis remains a risk factor for early pregnancy loss in the subsequent frozen euploid embryo transfer

RESEARCH QUESTION

Do patients with antibiotic-cured chronic endometritis (CCE) have a comparable pregnancy outcome to those with non-chronic endometritis (NCE) in the subsequent frozen embryo transfer (FET) cycle?

DESIGN

A retrospective cohort analysis included 833 patients in their first FET cycles with single euploid embryo transfer. Chronic endometritis (≥5 CD138+ plasma cells per high-power field [CD138+/HPF]) was treated with standard antibiotic therapy. Patients were classified into two groups: the NCE group (n = 611, <5 CD138+/HPF) and the CCE group (n = 222, ≥5 CD138+/HPF and cured after antibiotic treatment). Pregnancy outcomes were compared. NCE group was divided into subgroup 1 (CD138+/HPF = 0) and subgroup 2 (CD138+/HPF = 1-4) for further analysis.

RESULTS

The rate of early pregnancy loss (EPL), incorporating all losses before 10 weeks' gestation, was significantly higher in the CCE group than the NCE group (21.2% versus 14.2%, P = 0.016), and the difference was statistically significant (adjusted odds ratio [AOR] 1.68, 95% confidence interval [CI] 1.11-2.55). No significant differences were observed between the two groups with regard to other pregnancy outcomes. In the subgroup analysis, the EPL rate and biochemical pregnancy rate were significantly higher in subgroup 2 than subgroup 1 (17.2% versus 9.4%, AOR 2.21, 95% CI 1.30-3.74; 12.2% versus 6.9%, AOR 2.01, 95% CI 1.09-3.68).

CONCLUSIONS

Chronic endometritis cured by standard antibiotic therapy remains a risk factor for EPL in FET cycles, although no differences were found in live birth rates between patients with CCE or with NCE.

Ribosome-targeting antibiotic control NLRP3-mediated inflammation by inhibiting mitochondrial DNA synthesis

While antibiotics are designed to target bacteria specifically, most are known to affect host cell physiology. Certain classes of antibiotics have been reported to have immunosuppressive effects, but the underlying mechanisms remain elusive. Here, we show that doxycycline, a ribosomal-targeting antibiotic, effectively inhibited both mitochondrial translation and nucleotide-binding domain and leucine-rich repeat-containing protein 3 (NLRP3) inflammasome-mediated caspase-1 activation and interleukin-1β (IL-1β) production in bone-marrow-derived macrophages (BMDMs). In addition, knockdown of mitochondrial methionyl-tRNA formyltransferase (Mtfmt), which is rate limiting for mitochondrial translation, also resulted in the inhibition of NLRP3 inflammasome-mediated caspase-1 activation and IL-1β secretion. Furthermore, both doxycycline treatment and Mtfmt knockdown blocked the synthesis of mitochondrial DNA (mtDNA) and the generation of oxidized mtDNA (Ox-mtDNA), which serves as a ligand for NLRP3 inflammasome activation. In addition, in vivo results indicated that doxycycline mitigated NLRP3 inflammasome-dependent inflammation, including lipopolysaccharide-induced systemic inflammation and endometritis. Taken together, the results unveil the antibiotics targeting the mitoribosome have the ability to mitigate NLRP3 inflammasome activation by inhibiting mitochondrial translation and mtDNA synthesis thus opening up new possibilities for the treatment of NLRP3-related diseases.

The effect of chronic endometritis and treatment on patients with unexplained infertility

PURPOSE

This paper was mainly conducted to investigate the effect of chronic endometritis (CE) on the clinical outcome of patients with unexplained infertility.

MATERIALS AND METHODS

145 patients with unexplained infertility from the Reproductive Center of our hospital from January 2018 to December 2021 were selected as the unexplained infertility group. 42 patients with definite infertility causes were selected as the control group during the same period. Both groups of patients underwent hysteroscopy and immunohistochemical tests for CD38 and CD138. According to the results of hysteroscopy and immunohistochemistry, the incidence of CE between the two groups was analyzed. Patients with CE as CE group accepted oral antibiotic therapy for 14 days. Another 58 patients with unexplained infertility who did not undergo hysteroscopy and immunohistochemical tests for CD38 and CD138 were selected as the unexamined group. Both groups of patients were expected natural pregnancy. Follow-up lasted for 1 year, and the pregnant patients were followed up until delivery.The clinical pregnancy rate, spontaneous abortion rate and baby-carrying home rate of the two groups were compared.

RESULTS

There were 75 patients with CE in the unexplained infertility group, and the prevalence rate was 51.7% (75/145). Compared with the control group (28.6%), the incidence of CE was significantly higher (P < 0.05). After treated with antibiotic treatment, the patients' clinical pregnancy rate was 61.3% (46/75) and baby-carrying home rate was 60% (45/75) in the CE group, which were higher than those in the unexamined group(43.1% & 36.2%) (P < 0.05), while the spontaneous abortion rate was 2.2% (1/46),which was lower than that in the unexamined group (16.0%) (P < 0.05).

CONCLUSIONS

For patients with unexplained infertility, hysteroscopy combined with endometrial immunohistochemical detection of CD38 and CD138 should be performed in time to exclude CE. The clinical pregnancy outcome of CE patients can be significantly improved by antibiotic treatment.

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.

Follicular helper T lymphocytes in the endometria of patients with reproductive failure: Association with pregnancy outcomes and inflammatory status of the endometria

PROBLEM

The phenotypes and functions of B and CD4⁺ T-helper cell subsets during chronic inflammation of the endometria remain largely unexplored. This study aimed to investigate the characteristics and functions of follicular helper T (Tfh) cells to understand the pathological mechanisms of chronic endometritis (CE).

METHOD OF STUDY

Eighty patients who underwent hysteroscopic and histopathological examinations for CE were divided into three groups-those with positive results for hysteroscopy and CD138 staining (DP), negative results for hysteroscopy but positive CD138 staining (SP), and negative results for hysteroscopy and CD138 staining (DN). The phenotypes of B cells and CD4⁺ T-cell subsets were analyzed using flow cytometry.

RESULTS

CD38⁺ and CD138⁺ cells were mainly expressed in the non-leukocyte population of the endometria, and the endometrial CD19⁺ CD138⁺ B cells were fewer than the CD3⁺ CD138⁺ T cells. The percentage of Tfh cells increased with chronic inflammation in the endometria. Additionally, the elevated percentage of Tfh cells correlated with the number of miscarriages.

CONCLUSIONS

CD4⁺ T cells, particularly Tfh cells, may be critical in chronic endometrial inflammation and affect its microenvironment, thereby regulating endometrial receptivity, compared to B cells.

The association between chronic deciduitis and recurrent pregnancy loss

Chronic deciduitis (CD) is defined as the presence of lymphocytes or plasma cells in decidual tissue. CD suggests the presence of chronic endometritis (CE) which is associated with recurrent pregnancy loss (RPL). In this study, we examined the role CD plays in RPL patients with aneuploid and euploid miscarriage. The frequency of CD in 49 RPL patients (22 euploid and 27 aneuploid miscarriages) and 17 control women was assessed and the subsequent live birth rate (LBR) in the presence and absence of CD were compared. When only one CD138-positive endometrial stromal plasma cell (ESPC) was found per high-power field (HPF), we diagnosed small-positive CD (Grade 1). When a cluster of two or more CD138-positive ESPCs was found per HPF, we diagnosed it as CD Grade 2. The prevalence of Grade 1 was 18.2% (4/22) in patients with euploid miscarriage, 37.0% (10/27) in patients with aneuploid miscarriage and 23.5% (4/17) in control women. The prevalence of Grade 2 was 45.5% (10/22) in patients with euploid miscarriage, 55.6% (15/27) in patients with aneuploid miscarriage and 23.5% (4/17) in control women. There was a significant difference in the prevalence of CD (p = 0.015). The LBR of patients with CD was similar to that of patients without CD. CD was associated with RPL, especially in patients with aneuploid miscarriage. However, since there was no difference in the LBR of patients with or without CD in the next pregnancy, it was unclear whether CD was a contributing cause of RPL.

Commonalities and Disparities between Endometriosis and Chronic Endometritis: Therapeutic Potential of Novel Antibiotic Treatment Strategy against Ectopic Endometrium

Chronic endometritis (CE) is a local mucosal inflammatory disorder of the uterine lining, which is histopathologically recognized as the unusual infiltration of CD138(+) plasmacytes into the endometrial stromal compartment. Accumulating body of research documented that CE is associated with female infertility and several obstetric/neonatal complications. The major cause of CE is thought to be intrauterine infection represented by common bacteria (Escherichia coli, Enterococcus faecalis, Streptococcus, and Staphylococcus), Mycoplasma/Ureaplasma, and Mycobacterium. Additionally, local dysbiosis in the female reproductive tract may be involved in the onset and development of CE. Antibiotic treatments against these microorganisms are effective in the elimination of endometrial stromal plasmacytes in the affected patients. Meanwhile, endometriosis is a common female reproductive tract disease characterized by endometriotic tissues (ectopic endometrium) growing outside the uterus and potentially causes chronic pelvic symptoms (dysmenorrhea, dyspareunia, dyschezia, and dysuria), infertility, and ovarian cancers. Endometriosis involves endocrinological, genetic, and epigenetic factors in its etiology and pathogenesis. Recent studies focus on immunological, inflammatory, and infectious aspects of endometriosis and demonstrate several common characteristics between endometriosis and CE. This review aimed to better understand the immunological and microbial backgrounds underlying endometriosis and CE and look into the therapeutic potential of the novel antibiotic treatment strategy against endometriosis in light of endometrial infectious disease.

Vaginom- und „Endometriom“-Diagnostik bei Kinderwunsch

Die molekulare Diagnostik der Vaginal- und Endometriumflora ermöglicht neue Einblicke in die physiologische Besiedlung des weiblichen Genitaltrakts. Wesentlich ist hierbei eine Dominanz von bestimmten Laktobazillenarten bei gleichzeitig geringer Artenvielfalt. Die Bildung von D‑Laktat ist eine entscheidende Voraussetzung für die Abwehr von sexuell übertragbaren Erkrankungen, den Erfolg einer In-vitro-Fertilisation sowie einen ungestörten Schwangerschaftsverlauf. Eine Störung der Flora durch pathogene Bakterienarten mit der Folge des Auftretens einer bakteriellen Vaginose oder einer chronischen Endometritis kann zu Implantationsversagen, Aborten und Frühgeburtsbestrebungen führen. Bei wiederholtem Implantationsversagen ermöglicht eine Mikrobiomdiagnostik – im Gegensatz zur klassischen Kultur, den Amsel-Kriterien oder dem Nugent-Score – einen sehr viel detaillierteren Einblick in die Pathophysiologie, da sich entscheidende Bakterienarten nur schwer oder gar nicht anzüchten lassen. Dies erlaubt eine sehr viel bessere Planung der Therapie zur Wiederherstellung physiologischer Verhältnisse.