Acetaldehyde differentially affects the growth of uterine leiomyomata and myometrial cells in tissue cultures

Eutopic/ectopic endometrial apoptosis initiated by bilateral uterine artery occlusion: A new therapeutic mechanism for uterus-sparing surgery in adenomyosis

The objective of the present study was to investigate differences in the expression of apoptosis-related factors in the eutopic and ectopic endometrium (EuE/EE) in women with adenomyosis before and after laparoscopic bilateral uterine artery occlusion (LUAO). Ten patients with uterine adenomyosis who received LUAO were selected as the research subjects, from whom EuE and EE tissues were obtained before and after LUAO and detected for the expression of apoptosis-related molecules in EuE and EE by PT-PCR and Western blot, and changes in the mitochondrial structure by electron microscopy. Normal endometrial stromal cells (NESC), and EuE/EE stromal cells in women with adenomyosis were cultured in a 1% O2, 5% CO2 incubator to establish a physical anoxia state in an in vitro stromal cell model. The expression of apoptosis-related molecules was observed at 0, 6, 12, 24 and 48h of hypoxic. The results showed that the expression of apoptosis-related factors in EuE and EE were increased significantly after LUAO and under hypoxic conditions in vitro, suggesting that transient ischemia and hypoxia were involved in the apoptosis of adenomysis lesions, and that uterine artery occlusion could remove adenomyosis lesions on tissue/cell level by cytoreduction, thus reaching the goal of treating adenomyosis effectively.

Uterine leiomyoma research

Uterine leiomyoma is the most common type of benign tumor in women of reproductive age. This disease is rare before menarche, and its incidence decreases after menopause. Uterine leiomyoma is known to be related to hormonal changes, but the precise underlying mechanism has yet to be determined. Although it is a benign disease, the most common form of management involves surgical intervention. Uterine leiomyoma is also related to infertility and obstetric complications. Here, we present a review of the literature regarding uterine leiomyoma and discuss management of this disease.

Estrogen-mediated activation of fibroblasts and its effects on the fibroid cell proliferation

In this study, we explored the role of estrogen-mediated activation of stromal fibroblasts in the pathogenesis of uterine fibroid in patients. We isolated uterine fibroids and surrounding smooth muscle from patients and separated fibroblasts using immunomagnetic beads. We also measured the expression levels of estrogen receptors in fibroblasts and examined cell proliferation, expressions of fibroblast activation protein (FAP), extracellular matrix (ECM) (fibronectin, laminin, collagen I), growth factors (transforming growth factor-β, insulin-like growth factor-1), and cell proliferation pathway stimulated by estrogen. We also silenced the expression of FAP by RNA interference and analyzed the expression levels of these markers before and after E2 stimulation. Finally, we also investigated the effect of activated fibroblast supernatant on cell proliferation of fibroblasts, smooth muscle cells, and fibroid cells. We found that fibroblasts in uterine fibroid were activated, and the expression levels of estrogen receptors from fibroid cells were higher than those from smooth muscle cells. After estrogen stimulation, the proliferation activity of fibroblast was enhanced, and the expression of FAP, ECM, and growth factors was increased; the signaling pathway involved in cell proliferation was also activated. Interestingly, the activated fibroblast supernatant stimulation can promote cell proliferation. Silencing of FAP expression could inhibit the E2-mediated biological effects. In conclusion, estrogen promotes proliferation of uterine fibroids through the activation of fibroblasts, thus, activated fibroblasts may play an important role in the pathogenesis of uterine fibroids, which could be targeted in future for the treatment of uterine fibroid.

Discrepancy of uterine leiomyoma and myometrium to hypoxia-induced endoplasmic reticulum stress after uterine occlusion therapy accounts for therapeutic effect

PURPOSE

Uterine artery occlusion (UAO) is a promising method for the treatment of leiomyoma. This study is intended to demonstrate the discrepancy of ER stress-induced apoptosis in leiomyoma and myometrium as a result of UAO therapy.

METHODS

Primary cultured leiomyoma and myometrial cells were incubated in low oxygen supply (1 % O2). Then, real time RT-PCR and Western blotting were performed to analyze the mRNA and protein levels of ER stress-related molecules including GRP78, CHOP, JNK, Bax, Bcl-2 and Caspase4. Furthermore, the activity of Caspase4 was detected. Tissues of leiomyoma and myometria were also collected before and 30 min after UAO during surgery and evaluated.

RESULTS

The leiomyoma cells and tissues expressed higher ER stress-related molecules compared to myometrial cells or tissues, while the levels of Bcl-2, an anti-apoptotic protein, declined. In myometrial cells, an elevated level of Caspase4 activation as well as its expression was not significant during the first 12 h, suggesting that hypoxia might not intensely affect the myometrium compared with leiomyoma.

CONCLUSION

ER stress-related apoptosis partly accounts for the effects of UAO therapy on uterine leiomyoma, which leads to the death of leiomyoma while maintaining the survival of the uterus itself.

Endogenous acetaldehyde toxicity during antral follicular development in the mouse ovary

The biosynthesis of androgens requires multiple steps and during the conversion of pregnenolone to 17α-hydroxypregnenolone and dehydroepiandrosterone (DHEA) by CYP17a1. Acetaldehyde is potentially formed as a by-product in theca cells during antral follicular development. In this study, acetaldehyde level was significantly increased after eCG stimulation and reached a maximum level at 36-h post-eCG. By 48 h, the level of acetaldehyde decreased in association with the induction of aldehyde dehydrogenase (ALDH) type 1 family members. When immature mice were co-injected with the ALDH inhibitor, cyanamide, and eCG, the expression of genes involved in the differentiations of granulosa cells was suppressed and the number of ovulated oocytes was reduced. The in vitro studies showed that ALDH inhibitors prevented FSH-induced granulosa cell differentiation. These results indicate that acetaldehyde is generated as a by-product during steroidogenesis and can exert toxic effects to impair the differentiation of granulosa cells, reduce ovulation and decrease oocyte quality.

All-trans-retinoic acid mediates changes in PI3K and retinoic acid signaling proteins of leiomyomas

OBJECTIVE

To detect changes induced by all-trans-retinoic acid (ATRA) on the expression and activation of target proteins of the retinoic acid (RA) and PI3K/Akt pathways involved in leiomyoma growth.

DESIGN

A study on human tissue cultures.

SETTING

Hadassah University Hospital.

PATIENT(S)

Premenopausal women with uterine leiomyomas.

INTERVENTION(S)

Paired cultures of normal myometrium and leiomyomas, from women undergoing hysterectomy, were obtained.

MAIN OUTCOME MEASURE(S)

The effect of ATRA was examined on the expression and phosphorylation of relevant RA, PI3K/Akt, and Bcl2 proteins (immunochemical analysis), cell proliferation, cell cycle distribution, and apoptosis.

RESULT(S)

Applying our cell culture model, we demonstrated that ATRA induced changes in the expression and activation of the RA and PI3K/Akt pathway proteins in leiomyoma cells, with significant increases of alcohol dehydrogenase 1 and cyclin D2 protein levels. In part of the leiomyoma cells, ATRA induced a relative increase of Bax (proapoptotic) as well as a relative decrease of phosphorylated glycogen synthase kinase 3β (proapoptotic).

CONCLUSION(S)

Our results highlight the involvement of ATRA in the RA and PI3K/Akt pathways, whose specific signaling products may influence the outcome of leiomyoma growth by regulating cell proliferation, apoptosis, and survival. These results might be useful for the on-going research into alternative methods for treating and preventing this disorder.