Interleukin-34 accelerates intrauterine adhesions progress related to CX3CR1+ monocytes/macrophages

MSCs promote the efferocytosis of large peritoneal macrophages to eliminate ferroptotic monocytes/macrophages in the injured endometria

BACKGROUND

Endometria are one of the important components of the uterus, which is located in the peritoneal cavity. Endometrial injury usually leads to intrauterine adhesions (IUA), accompanied by inflammation and cell death. We previously reported that both the endometrial ferroptosis was increased and monocytes/macrophages were involved in endometrial injury of IUA. Large peritoneal macrophages (LPMs) are recently reported to migrate into the injured tissues and phagocytose dead cells to repair the tissues. We previously demonstrated that mesenchymal stromal cells (MSCs) had made excellent progress in the repair of endometrial injury. However, it is unclear whether MSCs regulate the LPM efferocytosis against ferroptotic monocytes/macrophages in the injured endometria.

METHODS

Here, endometrial injury in IUA mouse model was conducted by uterine curettage and LPS injection surgery and the samples were collected at different times to detect the changes of LPMs and ferroptotic monocytes/macrophages. We conducted LPMs depletion assay in vivo and LPMs and Erastin-induced ferroptotic THP-1 cells coculture systems in vitro to detect the LPM efferocytosis against ferroptotic monocytes/macrophages. The IUA model was treated with MSCs, and their effects on LPMs and endometrial repair were analyzed. Flow cytometry, western blotting, quantitative real-time PCR, immunohistochemical analysis, ELISA, and RNA-sequencing were performed.

RESULTS

We found that LPMs migrated to the injured uteri in response to the damage in early phase (3 h), and sustained to a later stage (7 days). Astonishingly, we found that ferroptotic monocytes/macrophages were significantly increased in the injured uteri since 12 h after injury. Moreover, LPMs cocultured with Erastin-induced ferroptotic THP-1 cells in vitro, efferocytosis of LPMs against ferroptotic monocytes/macrophages was emerged. The mRNA expression profiles revealed that LPM efferocytosis against ferroptotic monocytes/macrophages was an induction of glycolysis program and depended on the PPARγ-HK2 pathway. Importantly, we validated that MSCs promoted the efferocytic capability and migration of LPMs to the injured uteri via secreting stanniocalcin-1 (STC-1).

CONCLUSION

The data collectively demonstrated first the roles of LPMs via removal of ferroptotic monocytes/macrophages and provided a novel mechanism of MSCs in repairing the endometrial injury.

TSG6-Exo@CS/GP Attenuates Endometrium Fibrosis by Inhibiting Macrophage Activation in a Murine IUA Model

Intrauterine adhesion (IUA) is characterized by the formation of fibrous scar tissue within the uterine cavity, which significantly impacts female reproductive health and even leads to infertility. Unfortunately, severe cases of IUA currently lack effective treatments. This study presents a novel approach that utilizes tumor necrosis factor-(TNF) stimulated gene 6 (TSG6)-modified exosomes (Exos) in conjunction with an injectable thermosensitive hydrogel (CS/GP) to mitigate the occurrence of IUA by reducing endometrium fibrosis in a mouse IUA model. This study demonstrate that TSG6-modified Exos effectively inhibits the activation of inflammatory M1-like macrophages during the initial stages of inflammation and maintains the balance of macrophage phenotypes (M1/M2) during the repair phase. Moreover, TSG6 inhibits the interaction between macrophages and endometrial stromal fibroblasts, thereby preventing the activation of stromal fibroblasts into myofibroblasts. Furthermore, this research indicates that CS/GP facilitates the sustained release of TSG6-modified Exos, leading to a significant reduction in both the manifestations of IUA and the extent of endometrium fibrosis. Collectively, through the successful construction of CS/GP loaded with TSG6-modified Exos, a reduction in the occurrence and progression of IUA is achieved by mitigating endometrium fibrosis. Consequently, this approach holds promise for the treatment of IUA.

IL-4-induced M2 macrophages inhibit fibrosis of endometrial stromal cells

BACKGROUND

Intrauterine adhesions (IUA) refers to endometrial fibrosis caused by irreversible damage of the endometrial basal layer. As the key regulators in tissue repair, regeneration, and fibrosis, macrophages play an essential role in endometrial regeneration and repair during the normal menstrual cycle. However, the mechanism of macrophages involved in IUA remains unclear.

METHODS

In the late stages of proliferation, the endometrium was collected to make paraffin sections. HE and Masson staining were used to observing endometrial morphology and endometrial fibrosis. Immunohistochemistry and Western blotting were used to detect the expression level of fibrosis indexes COL1A1 and α-SMA. The macrophage infiltration was evaluated by immunohistochemistry for the expression levels of CD 206 and CD163. Next, we cultured the primary human endometrial stromal cells (HESCs), and then an IUA cell model was established with 10 ng/ml TGF-β1 for 72 h. THP 1 cells were differentiated by 100 ng/ml PMA into macrophages for 48 h, then macrophages were polarized to M2 macrophages by 20 ng/ml IL-4 for 24 h. The culture supernatants (M(IL-4) -S) of M2 macrophages were applied to the IUA cell model. The expression of fibrosis markers was then assessed using immunofluorescence and Western blotting.

RESULTS

The results show that Patients with IUA have fewer endometrial glands and significantly increased fibrosis levels. Moreover, the infiltration of CD206-positive (M2) macrophages was significantly reduced in IUA patients, and negatively correlated with the expression of endometrial fibrosis indexes α-SMA and COL1A1. In addition, the primary HESCs treated with 10 ng/ml TGF-β1 for 72 h were found to have significantly increased levels of fibrosis indexes. Furthermore, supernatants from IL4-induced M2 macrophages inhibit the TGF-β1-induced fibrosis of HESCs.

CONCLUSIONS

M2 macrophages may negatively regulate the expression of COL1A1 and α-SMA, inhibiting the TGF-β1-induced fibrosis of HESCs. Our study suggests that targeting macrophage phenotypes and promoting the polarization of macrophages to M2 may become a novel strategy for the clinical treatment of IUA.

Endometrial DNA methylation signatures during the time of breeding in relation to the pregnancy outcome in postpartum dairy cows fed a control diet or supplemented with rumen-protected methionine

Post calving metabolic stress reduces the fertility of high producing dairy cows possibly by altering the expression of genes in the maternal environment via epigenetic modifications. Therefore, this study was conducted to identify endometrial DNA methylation marks that can be associated with pregnancy outcomes in postpartum cows at the time of breeding. For this, twelve days post-calving, cows were either offered a control diet or supplemented daily with rumen-protected methionine. Cows showing heat 50-64 days postpartum were artificially inseminated. Endometrial cytobrush samples were collected 4-8 h after artificial insemination and classified based on the pregnancy out comes as those derived from cows that resulted in pregnancy or resulted in no pregnancy. The DNAs isolated from endometrial samples were then subject to reduced representative bisulfite sequencing for DNA methylation analysis. Results showed that in the control diet group, 1,958 differentially methylated CpG sites (DMCGs) were identified between cows that resulted in pregnancy and those that resulted in no pregnancy of which 890 DMCGs were located on chr 27: 6217254-6225600 bp. A total of 537 DMCGs were overlapped with 313 annotated genes that were involved in various pathways including signal transduction, signalling by GPCR, aldosterone synthesis and secretion. Likewise, in methionine supplemented group, 3,430 CpG sites were differentially methylated between the two cow groups of which 18.7% were located on Chr27: 6217254-6225600 bp. A total of 1,781 DMCGS were overlapped with 890 genes which involved in developmental and signalling related pathways including WNT-signalling, focal adhesion and ECM receptor interaction. Interestingly, 149 genes involved in signal transduction, axon guidance and non-integrin membrane-ECM interactions were differentially methylated between the two cow groups irrespective of their feeding regime, while 453 genes involved in axon guidance, notch signalling and collagen formation were differentially methylated between cows that received rumen protected methionine and control diet irrespective of their fertility status. Overall, this study indicated that postpartum cows that could potentially become pregnant could be distinguishable based on their endometrial DNA methylation patterns at the time of breeding.

Oroxylin A relieves intrauterine adhesion in mice through inhibiting macrophage pyroptosis via SIRT3-SOD2-ROS pathway

Intrauterine adhesion (IUA) is manifested by endometrial fibrosis and inflammation, which seriously affects female reproductive health. Macrophages are mainly inflammatory cells and have been reported to participate in the fibrosis of IUA. Oroxylin A (OA), a kind of flavonoid compounds, was showed to possess the inhibitory effects on inflammation and fibrosis. However, the role of OA in IUA remains unclear. In the present study, we found that OA effectively alleviated the level of inflammation and uterine fibrosis in IUA mice. OA also decreased the macrophage pyroptosis which increased in uteri of IUA mice. Pyroptosis is a programmed cell death accompanied by an inflammatory response. Moreover, OA repressed the mediators of pyroptosis including the expression of NOD-like receptor family pyrin domain containing 3 (NLRP3), caspase-1 and Gasdermin D (GSDMD) and the release of IL-1β, IL-18 and cleaved-caspase-1 in J774A.1 cells induced by LPS/ATP in vitro. Mechanistically, the alleviation of OA on uterine fibrosis is achieved by inhibiting macrophage pyroptosis via SIRT3-SOD2-ROS pathway. Our data indicate that OA may serve as an effective agent for the treatment of the endometrial fibrosis with IUA.

Tumor necrosis factor-α-primed mesenchymal stem cell-derived exosomes promote M2 macrophage polarization via Galectin-1 and modify intrauterine adhesion on a novel murine model

Background

Intrauterine adhesion (IUA) is a condition caused due to damage or infection of the endometrium. It is characterized by continuous inflammation and following fibrosis and dysfunction. However, the current animal IUA models have several disadvantages, including complex operation, high mortality, and many extra distractions owing to opening of the abdominal cavity to expose the uterus. Mesenchymal stem cells (MSCs), which have been used in treatment of IUA, are heterogeneous and immunosuppressive. However, their therapeutic effect is not as good as expected.

Methods

Here, we successfully built a new murine IUA model, called electric tool-scratching IUA model, and applied it in our experiments to investigate the efficacy of tumor necrosis factor-α (TNF-α) primed MSCs (T-MSCs). In the new model, we used a self-made electric tool that can cause mechanical damage to the endometrium without opening the abdominal cavity. ELISA and histological staining analysis were performed to evaluate pathological features of IUA. qRT-PCR, flow cytometry and immunofluoresence staining were performed to detect the phenotypes of macrophages. TMT proteomics quantification and western blotting assay were performed to analyze the differentially expressed proteins of MSC exosomes.

Results

Based on the new IUA model, we found TNF-α pretreatment could enhance the ability of MSCs to relieve inflammation and reduce endometrium fibrosis. Mechanistically, T-MSC promoted macrophage polarization to M2 phenotype through exosomes. Subsequently, we found the expression of Galectin-1 was increased in T-MSC exosomes. Finally, we analyzed the gene expression pattern of Galectin-1 treated macrophages and found Galectin-1 promoted macrophage polarization to M2 phenotype mainly through the Jak-STAT signaling pathway.

Conclusions

Our studies proposed an innovative mouse model and a better MSC treatment strategy for IUA.

Potential Molecular Mechanism of Guishen Huoxue Decoction against Intrauterine Adhesion Based on Network Pharmacology

Objective

Intrauterine adhesion (IUA) represents an endometrial repair disorder that is associated with menstrual disorders, recurrent pregnancy loss, and infertility. This study aimed to explore the underlying biological mechanisms of Guishen Huoxue decoction for the treatment of IUA based on network pharmacology.

Methods

The selection of active compounds for Guishen Huoxue decoction and prediction of relevant targets were performed by the TCMSP and Swiss Target Prediction databases, respectively. The targets of IUA were obtained by three databases, including Online Mendelian Inheritance in Man (OMIM), DisGeNET, and GeneCards. The drug-disease regulatory network was constructed via Cytoscape software, following the acquisition of common genes of active compounds of drug Guishen Huoxue decoction and disease IUA, which was carried out through Venny software. Protein-protein interaction (PPI) network and function enrichment analyses were performed.

Results

According to the data obtained from TCMSP, a total of 200 potential active compounds of Guishen Huoxue decoction and their related targets (1068) were screened by the Swiss Target Prediction database. 1303 disease targets and 134 common targets were identified. The drug-disease regulatory network showed that 165 active compounds were found to be involved in the treatment of IUA. Among 134 common targets, AKT1, SRC, TP53, VEGFA, and IL-6 were predicted as core genes against IUA. PI3K-Akt, Rap1, Ras, and AGE-RAGE were the main signaling pathways that participated in the treatment of Guishen Huoxue decoction for IUA.

Conclusion

The active compounds of Guishen Huoxue decoction confer therapeutic effects against IUA by regulating fibrosis, inflammation, and oxidative stress through major signaling pathways such as PI3K-Akt and AGE-RAGE.

Guidelines for the use of flow cytometry and cell sorting in immunological studies (third edition)

The third edition of Flow Cytometry Guidelines provides the key aspects to consider when performing flow cytometry experiments and includes comprehensive sections describing phenotypes and functional assays of all major human and murine immune cell subsets. Notably, the Guidelines contain helpful tables highlighting phenotypes and key differences between human and murine cells. Another useful feature of this edition is the flow cytometry analysis of clinical samples with examples of flow cytometry applications in the context of autoimmune diseases, cancers as well as acute and chronic infectious diseases. Furthermore, there are sections detailing tips, tricks and pitfalls to avoid. All sections are written and peer-reviewed by leading flow cytometry experts and immunologists, making this edition an essential and state-of-the-art handbook for basic and clinical researchers.