hymecromone and Endometriosis

To characterize the effects of 4-methylumbelliferone (4-MU) on expression of the hyaluronic acid (HA) system and on attachment, migration, and invasion of endometrial epithelial (EECs) and stroma cells (ESCs) to peritoneal mesothelial cells (PMCs), this in vitro study was performed in an Academic Center. De-identified endometrial tissue samples used were from reproductive-aged women. EECs and ESCs isolated from menstrual endometrial biopsies were treated with 4-MU or vehicle. Real-time polymerase chain reaction and western blot were used to assess expression of HA synthases (HAS), hyaluronidase, and standard CD44. Established in vitro assays were used to assess attachment, migration, and invasion with and without treatment with 4-MU. Chi square and Student's t-test were used to analyze the results as appropriate. The addition of 4-MU decreased mRNA and protein expression of HAS 2, HAS 3, and CD44 in EECs and ESCs compared to control. Treatment with 4-MU also decreased attachment, migration, and invasion of EECs and ESCs to PMCs compared to control. 4-MU decreases endometrial cell adhesion, migration, and invasion to PMCs. This effect appears to be mediated by a decrease in HAS 2, HAS 3, and CD44. 4-MU is a potential treatment for endometriosis. Future in vivo studies are needed to evaluate 4-MU as a therapeutic agent for endometriosis.

Topics: Cell Adhesion; Cell Line; Cell Movement; Endometriosis; Endometrium; Female; Humans; Hyaluronan Receptors; Hyaluronan Synthases; Hyaluronic Acid; Hyaluronoglucosaminidase; Hymecromone

The development and long-term survival of endometriotic lesions is crucially dependent on an adequate vascularization. Hyaluronic acid (HA) through its receptor CD44 has been described to be involved in the process of angiogenesis.. To study the effect of HA synthesis inhibition using non-toxic doses of 4-methylumbelliferone (4-MU) on endometriosis-related angiogenesis.. The cytotoxicity of different in vitro doses of 4-MU on endothelial cells was firstly tested by means of a lactate dehydrogenase assay. The anti-angiogenic action of non-cytotoxic doses of 4-MU was then assessed by a rat aortic ring assay. In addition, endometriotic lesions were induced in dorsal skinfold chambers of female BALB/c mice, which were daily treated with an intraperitoneal injection of 0.9% NaCl (vehicle group; n = 6), 20 mg/kg 4-MU (n = 8) or 80 mg/kg 4-MU (n = 7) throughout an observation period of 14 days. The effect of 4-MU on their vascularization, survival and growth were studied by intravital fluorescence microscopy, histology and immunohistochemistry.. Non-cytotoxic doses of 4-MU effectively inhibited vascular sprout formation in the rat aortic ring assay. Endometriotic lesions in dorsal skinfold chambers of 4-MU-treated mice dose-dependently exhibited a significantly smaller vascularized area and lower functional microvessel density when compared to vehicle-treated controls. Histological analyses revealed a downregulation of HA expression in 4-MU-treated lesions. This was associated with a reduced density of CD31-positive microvessels within the lesions. In contrast, numbers of PCNA-positive proliferating and cleaved caspase-3-positive apoptotic cells did not differ between 4-MU-treated and control lesions.. The present study demonstrates for the first time that targeting the synthesis of HA suppresses angiogenesis in developing endometriotic lesions. Further studies have to clarify now whether in the future this anti-angiogenic effect can be used beneficially for the treatment of endometriosis.

Topics: Angiogenesis Inhibitors; Animals; Aorta; Apoptosis; Caspase 3; Cell Proliferation; Down-Regulation; Endometriosis; Endometrium; Female; Hyaluronic Acid; Hymecromone; Male; Mice; Mice, Inbred BALB C; Microvessels; Neovascularization, Physiologic; Platelet Endothelial Cell Adhesion Molecule-1; Proliferating Cell Nuclear Antigen; Rats; Rats, Sprague-Dawley