miR-149-PARP-2 Signaling Regulates E-cadherin and N-cadherin Expression in the Murine Model of Endometrium Receptivity

Specific and shared biological functions of PARP2 - is PARP2 really a lil' brother of PARP1?

PARP2, that belongs to the family of ADP-ribosyl transferase enzymes (ART), is a discovery of the millennium, as it was identified in 1999. Although PARP2 was described initially as a DNA repair factor, it is now evident that PARP2 partakes in the regulation or execution of multiple biological processes as inflammation, carcinogenesis and cancer progression, metabolism or oxidative stress-related diseases. Hereby, we review the involvement of PARP2 in these processes with the aim of understanding which processes are specific for PARP2, but not for other members of the ART family. A better understanding of the specific functions of PARP2 in all of these biological processes is crucial for the development of new PARP-centred selective therapies.

The lncRNA LINC00339-encoded peptide promotes trophoblast adhesion to endometrial cells via MAPK and PI3K-Akt signaling pathways

BACKGROUND

Endometrial receptivity (ER), a pivotal event for successful embryo implantation, refers to the capacity of endometrium to allow the adhesion of the trophectoderm of the blastocyst to endometrial cells. In this paper, we set to elucidate whether the peptides encoded by lncRNAs could influence trophoblast cells' adhesion to endometrial cells.

METHODS

WGCNA construction and bioinformatics were used to find out the ER-related lncRNAs with coding potential. Protein analysis was done by immunoblotting and immunofluorescence (IF) microscopy. CCK-8 and Calcein-AM/PI double staining assays were employed to evaluate cell viability. The effect of the peptide on trophoblast spheroids' adhesion to endometrial cells was evaluated. The RNA sequencing (RNA-seq) analysis was applied to identify downstream molecular processes.

RESULTS

lncRNA LINC00339 was found to be related to ER development and it had been predicted to have protein-coding potential. LINC00339 had high occupancy of ribosomes and was confirmed to encode a 49-aa peptide (named LINC00339-205-49aa). LINC00339-205-49aa could promote the attachment of JAR trophoblast spheroids to Ishikawa endometrial cells in vitro. LINC00339-205-49aa also upregulated the expression of E-cadherin in Ishikawa cells. Mechanistically, MAPK and PI3K-Akt signaling pathways were involved in the modulation of LINC00339-205-49aa, which were activated by LINC00339-205-49aa in Ishikawa cells.

CONCLUSION

These data demonstrate that a previously uncharacterized peptide encoded by lncRNA LINC00339 has the ability to enhance JAR trophoblast spheroids' adhesion to Ishikawa endometrial cells, highlighting a new opportunity for the development of drugs to improve ER.

Ligustilide enhances pregnancy outcomes via improvement of endometrial receptivity and promotion of endometrial angiogenesis in rats

Ligustilide (LIG) is the main active ingredient of Angelica sinensis (Oliv.) Diels, which could promote focal angiogenesis to exert neuroprotection. However, there was no report that verified the exact effects of LIG on endometrial angiogenesis and the pregnancy outcomes. To explore the effects of LIG on low endometrial receptivity (LER) and angiogenesis, pregnancy rats were assigned into Control (saline treatment), LER (hydroxyurea-adrenaline treatment), LIG 20 mg/kg and LIG 40 mg/kg groups. Hematoxylin and eosin (H&E) staining was performed to evaluate endometrial morphology. Quantitative real-time PCR, immunofluorescence staining, western blot and immunohistochemistry staining were employed to assess the expression of endometrial receptivity factors and angiogenesis-related gene/protein, respectively. RNA sequencing was used to analyze the effects of LIG on LER caused by Kidney deficiency and blood stasis. We found that endometrial thickness and the implanted embryo number were substantially reduced in the hydroxyurea-adrenaline-treated pregnancy rats. At the same time, the gene and protein expressions of ERα, LIF, VEGFA and CD31 in the endometrium were markedly reduced, while the expressions of MUC1, E-cadherin were increased in the LER group. Administration of LIG raised the endometrial thickness and implanted embryos, as well as reversed the expressions of these factors. Collectively, our findings revealed that LIG could facilitate embryo implantation via recovery of the endometrium receptivity and promotion of endometrial angiogenesis.

M2 macrophages enhance endometrial cell invasiveness by promoting collective cell migration in uterine adenomyosis

RESEARCH QUESTION

Are M2 macrophages implicated in endometrial invasiveness in adenomyosis?

DESIGN

Seventeen formalin-fixed paraffin-embedded uterine samples and 16 fresh endometrial biopsies were collected from women with or without adenomyosis. Double immunofluorescence was performed to determine the predominant macrophage population in adenomyosis between M1 and M2 phenotypes. The invasion capacity of endometrial cells was assessed by invasion assays and quantitative polymerase chain reaction for genes involved in cell motility and epithelial-mesenchymal transition (EMT). Specific mechanisms of invasion were investigated by immunohistochemistry for E-cadherin, N-cadherin and matrix metalloproteinase 9 (MMP9).

RESULTS

Only M2 macrophages were found to accumulate in adenomyosis, in higher numbers in both eutopic endometrium (P = 0.0109) and lesions (P = 0.0267) than healthy tissue. Co-culture with M2 macrophages significantly boosted invasion capacity in endometrial epithelial (P = 0.0002; P = 0.002) and stromal cells (P = 0.0469; P = 0.0047) from both adenomyosis patients and healthy controls. No gene expression differences indicating EMT were noted, either between co-cultured and control cells, or between healthy and adenomyotic cells. E- and N-cadherin protein expression did not differ significantly between endometrium from adenomyosis subjects and healthy tissue but MMP9 expression was increased in eutopic stroma from adenomyosis patients (P = 0.0492). In adenomyosis, both E-cadherin (P = 0.0379) and N-cadherin (P = 0.0196) were more extensively expressed in basal glands than functional glands.

CONCLUSIONS

M2 macrophages accumulate in adenomyosis and enhance invasion capacity of adenomyotic and even healthy endometrial cells, implying that macrophage infiltration alone may be sufficient to promote the disease. This study failed to detect any changes pointing to EMT, suggesting an alternative mode of invasion. Strong E- and N-cadherin-positive intercellular junctions in basal (invasive) glands suggest the involvement of collective cell migration in the invasion process of endometrium.

The Role of Cadherin 12 (CDH12) in the Peritoneal Fluid among Patients with Endometriosis and Endometriosis-Related Infertility

Cadherin 12 (CDH 12) can play a role in the pathogenesis of endometriosis. The aim of this study was to compare the levels of cadherin 12 in the peritoneal fluid between women with and without endometriosis. This was a multicenter cross-sectional study. Eighty-two patients undergoing laparoscopic procedures were enrolled in the study. Cadherin 12 concentrations were determined using the enzyme-linked immunosorbent assay. The level of statistical significance was set at p < 0.05. No differences in cadherin 12 concentrations between patients with and without endometriosis were observed (p = 0.4). Subgroup analyses showed that CDH 12 concentrations were significantly higher in patients with infertility or primary infertility and endometriosis in comparison with patients without endometriosis and without infertility or primary infertility (p = 0.02) and also higher in patients with stage I or II endometriosis and infertility or primary infertility than in patients without endometriosis and infertility or primary infertility (p = 0.03, p = 0.048, respectively). In total, CDH 12 levels were significantly higher in patients diagnosed with infertility or primary infertility (p = 0.0092, p = 0.009, respectively) than in fertile women. Cadherin 12 can possibly play a role in the pathogenesis of infertility, both in women with and without endometriosis.