Development of an animal model for endometrial ablation using trichloroacetic acid

A Novel Endogenous Damage Signal, CSF-2, Activates Multiple Beneficial Functions of Adipose Tissue-Derived Mesenchymal Stem Cells

The major challenges of current mesenchymal stem cell (MSC)-based therapeutics are their low differentiation potential into specialized cell types and their homing ability to sites of injury. Therefore, many researchers have directed their efforts toward finding a novel stimulatory factor that can significantly enhance the therapeutic effects of MSCs. Colony-stimulating factor 2 (CSF-2) is previously known as a hematopoietic growth factor involved in the differentiation of various myeloid cells from hematopoietic progenitor cells. In addition to this canonical hematopoietic function, we identified for the first time that CSF-2 is actively secreted by stem cells, in response to various types of injuries, as an endogenous damage signal that promotes the therapeutic effects of MSCs by enhancing their multi-lineage differentiation and migratory capacities, possibly through its receptor CD116. Our results also revealed that CSF-2 exerts its stimulatory effects on MSCs via PI3K/Akt- and/or FAK/ERK1/2-signaling pathways. More importantly, we also found that MSCs stimulated with CSF-2 show markedly enhanced differentiation and migratory capacities and subsequent in vivo therapeutic effects in an endometrial ablation animal model. Collectively, our findings provide compelling evidence for a novel non-hematopoietic function of CSF-2 in promoting multiple beneficial functions of MSCs via a non-canonical mechanism as an endogenous damage signal.

The effects of sclerotherapy with 5% trichloroacetic acid on the cyst diameter and ovarian tissue in the rat ovarian cyst model

The aim of this study was to compare the effects of only aspiration with aspiration and 5% trichloroacetic acid (TCA) application on ovarian cyst size and ovarian reserve. The ovarian cysts of 14 rats that were divided into two groups randomly were investigated after total salpingectomy procedure. G1 was the group of saline application after cyst aspiration, while in G2, after aspiration 5% TCA at half amount of aspiration volume was injected into the cyst and re-aspirated after five minutes. The abdomens of the rats were closed and re-explored after 1 month. The cyst diameters of the rats in each group were measured. Ovaries were removed for histopathological examination. There was no significant difference in cyst diameter in G1 before and after aspiration. In G2, there was a significant decrease in cyst size after TCA application. Ovarian follicle counts were not significantly different between the two groups. In conclusion, application of 5% TCA to the ovarian cysts for five minutes significantly reduces the cyst size. Impact Statement What is already known on this subject: Minimally invasive therapies come into prominence to avoid surgical complications and diminished fertility in the treatment of ovarian cysts. USG-guided aspiration and sclerosis has been reported as cost-efficient and effective treatment methods for localised benign cysts in other organs such as the thyroid, parathyroid, liver, kidney and spleen. It has been shown that sclerotherapy applied to infertile women with ovarian cysts reduces pelvic pain without affecting the number of follicles, term pregnancy and abortion rates, extracted oocytes, embryo quality or hormonal levels when compared to non-ovarian cystic infertile women. TCA is a chemical agent that is topically applied, not systemically absorptive, which causes denaturation of proteins and structural cell death, resulting in coagulation necrosis after chemical cauterisation. For this reason, we used 5% TCA to treat simple ovarian cysts on a rat model. What the results of this study add: In this experimental study, we showed that the application of 5% TCA into the cyst for five minutes - then aspirated - significantly reduced the size of the ovarian cysts. Five percent TCA application did not affect the ovarian reserve. What the implications are of these findings for clinical practice and/or further research: Our study is original because of the fact that to the best of our knowledge, this is the first study about the use of 5% TCA in treatment of ovarian cysts in the literature.

Adipose-Derived Stromal Vascular Fraction Cell Effects on a Rodent Model of Thin Endometrium

Endometrial dysfunction affects approximately 1% of infertile women, and there is currently no standard therapy for improving fertility treatment outcomes in these patients. In our study, we utilized a rodent model of thin endometrium to test whether intrauterine application of adipose-derived stromal vascular fraction cells (SVF) could improve morphological and physiological markers of endometrial receptivity. Using anhydrous ethanol, endometrial area and gland density were significantly reduced in our model of thin endometrium. Application of SVF was associated with a 29% reduction in endometrial vascular endothelial growth factor (VEGF) expression and significant increases in uterine artery systolic/diastolic velocity ratios and resistance index values, suggesting reduced diastolic microvascular tone. However, no significant improvements in endometrial area or gland density were observed following SVF treatment. 3D confocal imaging demonstrated poor engraftment of SVF cells into recipient tissue, which likely contributed to the negative results of this study. We suspect modified treatment protocols utilizing adjuvant estrogen and/or tail vein cell delivery may improve SVF retention and therapeutic response in subsequent studies. SVF is an easily-obtainable cell product with regenerative capability that may have a future role in the treatment of infertile women with endometrial dysfunction.

Preventive effect of oral mucosal epithelial cell sheets on intrauterine adhesions

STUDY QUESTION

Can regenerative-medicine techniques using oral mucosal epithelial cell sheets (OMECS) provide a new treatment method for intrauterine adhesions (IUA) which cause female infertility?

SUMMARY ANSWER

Transplantation of OMECS was confirmed to be effective in preventing IUA after endometrial damage in rats.

WHAT IS KNOWN ALREADY

Uterine disorders such as IUA, commonly known as Asherman's syndrome, are one factor that can result in infertility. Clinical therapy for this kind of disease is targeted at the prevention of re-adhesion by surgical synechiotomy, administration of hormones after the operation, and the use of intrauterine devices. Recently, a new approach called 'cell-sheet engineering', which harvests confluent culture cells as a contiguous cell sheet having intact cell-cell junctions and an extracellular matrix, without having to use enzymatic treatment, has been developed for tissue regeneration.

STUDY DESIGN, SIZE, DURATION

OMECS were prepared from rat oral mucosal tissues. An IUA model was made in rat uteri, and OMECS were transplanted into the model. Uteri transplanted with OMECS were compared with the non-transplanted control uteri by histological analysis at 1, 2 and 8 days after surgery (n = 3).

PARTICIPANTS/MATERIALS, SETTING, METHODS

Oral mucosal tissues were resected from neonatal rats, and oral mucosal epithelial cells were collected with enzymatic treatment. An isolated cell suspension was seeded on a temperature-responsive cell culture-insert and incubated. After being detached from the insert, a cell sheet was transplanted onto the endometrium defect. At 1, 2 and 8 days after surgery, uteri were resected and examined.

MAIN RESULTS AND THE ROLE OF CHANCE

Histological examination of the non-treated specimens at 1, 2 and 8 days after surgery did not show any uterine cavities typically caused by IUA. In contrast, the histology of uteri transplanted with OMECS immediately after endometrial damage showed the presence of uterine cavities, and furthermore, stratified squamous epithelial cells on the luminal surface (n = 3).

LIMITATIONS, REASONS FOR CAUTION

The results of this study are difficult to apply directly to humans, because the structure and function of rat uteri are different from those of human.

WIDER IMPLICATIONS OF THE FINDINGS

Transplantation of OMECS offers a reliable method not only to protect the woman's fertility from intrauterine re-adhesion after synechiotomy for IUA or uterine lumen adhesion but also to prevent adhesion after any intrauterine surgery in clinical cases.