Effect of gonadotropin-releasing hormone agonists on monocyte chemotactic protein-1 production and macrophage infiltration in leiomyomatous uterus

Macrophages and Immune Responses in Uterine Fibroids

Uterine fibroids represent the most common benign tumors of the uterus. They are considered a typical fibrotic disorder. In fact, the extracellular matrix (ECM) proteins—above all, collagen 1A1, fibronectin and versican—are upregulated in this pathology. The uterine fibroids etiology has not yet been clarified, and this represents an important matter about their resolution. A model has been proposed according to which the formation of an altered ECM could be the result of an excessive wound healing, in turn driven by a dysregulated inflammation process. A lot of molecules act in the complex inflammatory response. Macrophages have a great flexibility since they can assume different phenotypes leading to the tissue repair process. The dysregulation of macrophage proliferation, accumulation and infiltration could lead to an uncontrolled tissue repair and to the consequent pathological fibrosis. In addition, molecules such as monocyte chemoattractant protein-1 (MCP-1), granulocyte macrophage-colony-stimulating factor (GM-CSF), transforming growth factor-beta (TGF-β), activin A and tumor necrosis factor-alfa (TNF-α) were demonstrated to play an important role in the macrophage action within the uncontrolled tissue repair that contributes to the pathological fibrosis that represents a typical feature of the uterine fibroids.

Pathophysiological roles of chemokines in human reproduction: an overview

Chemokines are a group of small cytokines that have an ability to induce leukocyte migration. Chemokines exert their functions by binding and activating specific G protein-coupled receptors. Studies have unveiled pleiotropic bioactivities of chemokines in various phenomena ranging from immunomodulation, embryogenesis, and homeostasis to pathogenesis. In the mammalian reproductive system, chemokines unexceptionally serve in multimodal events that are closely associated with establishment, maintenance, and deterioration of fecundity. The aim of this review is to update the knowledge on chemokines in male and female genital organs, with a focus on their potential pathophysiological roles in human reproduction.

Cellular biology of myomas: interaction of sex steroids with cytokines and growth factors

Many investigators who have been trying to delineate the pathophysiology of leiomyomata believe in the autocrine-paracrine model of tumor growth,where ovarian hormones act as regulators of gene expression in cells. These affected cells overproduce the stimulatory and fibrogenic cytokines and growth factors to which they respond, resulting in sustained, self-stimulated proliferation and fibrogenesis. A number of cytokines and growth factors have been investigated in leiomyomata to determine which cytokines or factors may be responsible for mediating the growth-promoting effects of ovarian hormones. A review of the literature reveals that TGF-3 is the only growth factor shown to be overexpressed in leiomyomata versus myometrium, hormonally regulated both in vivo and in vitro, and both mitogenic and fibrogenic in these tissues. The authors believe that, given the extent and depth of the current research on the cellular biology of leiomyoma, the cellular mechanisms responsible in the pathogenesis of leiomyoma will be identified clearly within the foreseeable future. This will enable researchers to develop therapy directed against the molecules and mechanisms at the cellular level, which undoubtedly will have a major impact on the number of hysterectomies being performed for a"fibroid uterus."

RU486 inhibits expression of lysophosphatidic acid induced glycodelin

OBJECTIVE

This study was undertaken to provide evidence for the mode of action of RU486 on glycodelin produced in K562 cells. To show that histiocytes may be a source of glycodelin in leiomyoma.

STUDY DESIGN

With the use of K562, a leukemia cell line, the effect of lysophosphatidic acid (LPA), RU486, antioxidants, and ZK112,993 on glycodelin protein and gene expression was studied. Immunocytochemistry for glycodelin and HAM-56 (macrophage) was performed on leiomyoma and myometrium.

RESULTS

Incubation of K562 cells with LPA, progesterone, ZK112,933 and RU486 significantly induced the expression of glycodelin protein and messenger RNA. The addition of RU486 to LPA activated cells markedly reduced expression of glycodelin. Addition of ZK112,993, an antiprogestin without antioxidant properties, to LPA activated cells did not reduce glycodelin. Histiocytes in leiomyoma and myometrium co-localize with glycodelin.

CONCLUSION

RU486, partly acting as an antioxidant, markedly reduces LPA stimulated glycodelin production. Histiocytes in leiomyoma and myometrium immunostain for glycodelin and suggests a source for glycodelin in leiomyoma.

Outcome in patients undergoing unilateral uterine artery embolization for symptomatic fibroids

AIMS

To evaluate patients undergoing uterine artery embolization for symptomatic fibroids who, for technical reasons, underwent unilateral rather than bilateral embolization.

PATIENTS

Prospective data were collected on 109 patients undergoing uterine artery embolization for symptomatic fibroids. Of these, six underwent unilateral embolization. They were followed with ultrasound or magnetic resonance imaging (MRI) at 3, 6 and 12 months. Patients' histories were reviewed and patients were asked to evaluate their symptoms at 3, 6 and 12 months on a scoring system, which scored their pre-embolization symptoms as 10.

RESULTS

In one case the patient's symptoms did not change in the first 3 months. This patient underwent a second embolization procedure to occlude the non-embolized uterine artery. In four cases the patients' symptoms had begun to resolve at 3 months and by 12 months the patients no longer required any further treatment. In one case the patient passed a 10 cm fibroid per vagina 2 months post uterine artery embolization. After this the patient had a normal uterus on MRI and no further symptoms.

CONCLUSION

Where planned bilateral uterine artery embolization is not possible for technical reasons and a unilateral embolization only is performed a conservative approach is indicated.

Interactions of cytokines, growth factors, and the extracellular matrix in the cellular biology of uterine leiomyomata

OBJECTIVE

To review the available information regarding the role of cytokines, growth factors, and the extracellular matrix in the pathophysiology of uterine leiomyomata and to integrate this information in a suggested model of disease at the cellular level.

DESIGN

A thorough literature and MEDLINE search was conducted to identify the relevant studies in the English literature published between January, 1966 and October, 2001. A model of disease at the cellular level was developed using the most likely cytokines to be involved in the pathogenesis of leiomyomata as determined by our assessment of the available literature.

RESULT(S)

A number of cytokines and growth factors, including transforming growth factor-beta (TGF-beta), epidermal growth factor, monocyte chemotactic protein-1, insulin-like growth factors 1 and 2, prolactin, parathyroid-hormone-related peptide, basic fibroblast growth factor, platelet-derived growth factor, interleukin-8, and endothelin, have been investigated in myometrium and leiomyoma. Among these cytokines, TGF-beta appears to be the only growth factor that has been shown to be overexpressed in leiomyoma vs. myometrium, be hormonally-regulated both in vivo and in vitro, and be both mitogenic and fibrogenic in these tissues. In addition to the cytokines, extracellular matrix components such as collagen, fibronectin, proteoglycans, matrix metalloproteinases, and tissue inhibitors of metalloproteinases seem to play pivotal roles in the pathogenesis of leiomyomata.

CONCLUSION(S)

We believe that, given the extent and depth of the current research on the cellular biology of leiomyomata, the cellular mechanisms responsible in the pathogenesis of leiomyomata will be identified clearly within the foreseeable future. This will enable researchers to develop therapy directed against the molecules and mechanisms at the cellular level.