The aim of the present study was to explore the underlying mechanisms of the roles of mechanical factors in the pathogenesis of pelvic organ prolapse (POP). The experiments were performed on fibroblasts derived from uterosacral ligaments and cardinal ligaments of patients who received total hysterectomy due to benign disease excluding POP. Fibroblasts were cultured after collagenase digestion and identified by morphological observation and immunocytochemical methods. A four‑point bending device was used to subject fibroblasts at passage 4‑6 to strains of 0, 1,333 µ (1 mm), 2,666 µ (2 mm) or 5,333 µ (4 mm) at a frequency of 0.1 Hz for 4 h. Intracellular reactive oxygen species (ROS) were quantified using the fluorescent probe 2',7'‑dichlorodihydrofluorescein diacetate. Changes in the mitochondrial membrane potential were verified using the fluorescent dye JC‑1, and apoptosis was detected using Annexin V/propidium iodide staining and flow cytometric analysis. Mechanical strain changed the morphology and adherence ability of parametrial ligament fibroblasts. Furthermore, the production of ROS was significantly increased and the mitochondrial membrane potential obviously declined with the enhancement of mechanical stress loading. In addition, the apoptotic rate of fibroblasts subjected to high mechanical strain was significantly increased compared with that in fibroblast under low‑intensity strain. In conclusion, the present study showed that mechanical strain enhanced intracellular ROS levels, decreased the mitochondrial membrane potential and increased the apoptotic rate in human parametrial ligament fibroblasts, which may contribute to POP.

Pelvic organ prolapse (POP) is a global health problem, for which the pathophysiological mechanism remains to be fully elucidated. The loss of extracellular matrix protein has been considered to be the most important molecular basis facilitating the development of POP. Oxidative stress (OS) is a well-recognized mechanism involved in fiber metabolic disorders. The present study aimed to clarify whether OS exists in the uterosacral ligament (USL) with POP, and to investigate the precise role of OS in collagen metabolism in human USL fibroblasts (hUSLFs). In the present study, 8-hydroxyguanosine (8-OHdG) and 4 hydroxynonenal (4-HNE), as oxidative biomarkers, were examined by immunohistochemistry to evaluate oxidative injury in USL sections in POP (n=20) and non-POP (n=20) groups. The primary cultured hUSLFs were treated with exogenous H2O2 to establish an original OS cell model, in which the expression levels of collagen, type 1, α1 (COL1A1), matrix metalloproteinase (MMP)-2, tissue inhibitor of metalloproteinase (TIMP)-2 and transforming growth factor (TGF)-β1 were evaluated by western blot and reverse transcription-quantitative polymerase chain reaction analyses. The results showed that the expression levels of 8-OHdG and 4-HNE in the POP group were significantly higher, compared with those in the control group. Collagen metabolism was regulated by H2O2 exposure in a concentration-dependent manner, in which lower concentrations of H2O2 (0.1–0.2 mM) stimulated the anabolism of COL1A1, whereas a higher concentration (0.4 mM) promoted catabolism. The expression levels of MMP-2, TIMP-2 and TGF-β1 exhibited corresponding changes with the OS levels. These results suggested that OS may be involved in the pathophysiology of POP by contributing to collagen metabolic disorder in a severity-dependent manner in hUSLFs, possibly through the regulation of MMPs, TIMPs and TGF-β1 indirectly.

Shaoyao-gancao-tang, a Chinese medicinal formula consisting of peony and licorice has been used for the treatment of dysmenorrhea for thousands of years. The purpose of the present study was to demonstrate the analgesic and uterine relaxant effects of isoliquiritigenin (ISL), a flavonoid isolated from the roots of Glycyrrhiza glabra (a type of licorice). In vitro, isoliquiritigenin caused concentration-dependent inhibition of spontaneous contraction of isolated rat uterus and the contraction induced by various types of stimulants, such as acetylcholine (Ach, 10 mM), KCl (40 mM) and oxytocin (1 mU/mL). The uterine contractile response to cumulative concentrations of CaCl₂ was blocked by 0.1 and 1 mM of isoliquiritigenin. The isoliquiritigenin-induced relaxation was partly inhibited by the nitric oxide synthase (NOS) inhibitor Nv-nitro-L-arginine methylester (L-NAME, 100 mM) and the COX-1/COX-2 inhibitor indomethacin (10mM). In vivo, isoliquiritigenin could cause a significant reduction in the acetic acid-induced writhing response and hot-plate test at the high dose. These results indicate that isoliquiritigenin, a flavonoid isolated from the roots of Glycyrrhiza glabra, not only has a spasmolytic effect on uterine contraction, which is in relation to Ca²⁺ channels, NOS and COX, but also an effective activity in reducing pain.

Mechanical loading on pelvic supports contributes to pelvic organ prolapse (POP). However, the underlying mechanisms remain to be elucidated. Our previous study identified that mechanical strain induced oxidative stress (OS) and promoted apoptosis and senescence in pelvic support fibroblasts. The aim of the present study is to investigate the molecular signaling pathway linking mechanical force with POP. Using a four-point bending device, human uterosacral ligament fibroblasts (hUSLF) were exposed to mechanical tensile strain at a frequency of 0.3 Hz and intensity of 5333 µε, in the presence or absence of LY294002. The applied mechanical strain on hUSLF resulted in apoptosis and senescence, and decreased expression of procollagen type I α1. Mechanical strain activated phosphatidylinositol-4,5-bisphosphate 3-kinase (PI3K)/Akt signaling and resulted in downregulated expression of glutathione peroxidase 1 and Mn-superoxide dismutase, and accumulation of intracellular reactive oxygen species. These effects were blocked by administration of LY294002. Furthermore, it was demonstrated that PI3K/Akt was activated in the uterosacral ligaments of POP patients, and that OS was increased and collagen type I production reduced. The results from the present study suggest that mechanical strain promotes apoptosis and senescence, and reduces collagen type I production via activation of PI3K/Akt-mediated OS signaling pathway in hUSLF. This process may be involved in the pathogenesis of POP as it results in relaxation and dysfunction of pelvic supports.

Pelvic organ prolapse (POP) is a common and distressing health problem in adult women, but the pathophysiological mechanism is yet to be fully elucidated. Previous studies have indicated that oxidative stress may be associated with POP. Thus, the aim of the present study was to investigate the oxidative status of pelvic supportive tissue in POP and further demonstrate that oxidative stress is associated with the pathogenesis of POP. A total of 60 samples were collected from females undergoing hysterectomy for POP or cervical intraepithelial neoplasia (CIN). This included 16 females with POP II, 24 females with POP III–IV (according to the POP-Q system) and 20 females with CIN II–III as the control group. Immunohistochemistry was utilized to measure the expression of oxidative biomarkers, 8-hydroxydeoxyguanosine (8-OHdG) and 4-hydroxynonenal (4-HNE). Major antioxidative enzymes, mitochondrial superoxide dismutase (MnSOD) and glutathione peroxidase 1 (GPx1) were measured through reverse transcription-quantitative polymerase chain reaction, western blotting and enzyme activity assays. The results demonstrated that in the cardinal ligament, the expression of 8-OHdG and 4-HNE was higher in the POP III–IV group compared with the POP II group and control group. The MnSOD and GPx1 protein level and enzyme activity were lower in the POP III–IV group compared with the POP II or the control group, while the mRNA expression level of MnSOD and GPx1 was increased. In conclusion, oxidative damage is increased in the pelvic supportive ligament of female patients with POP and the antioxidative defense capacity is decreased. These results support previous findings that oxidative stress is involved in the pathogenesis of POP.

Gestation and delivery can increase intra-abdominal pressure, which are well-known risk factors for Pelvic Organ Prolapse (POP). But the pathogenesis mechanism of POP remains unclear. Our previous research showed that the expression of glutathione peroxidase type 1 (GPX1) decreased in pelvic floor ligaments from POP patients, implying that oxidative stress (OS) may be related to POP. The aim of this study was to figure out the role of GPx1 regulation in the pathogenesis of POP. Women (>45 years) who received hysterectomy surgery were enrolled in this research, identified by screening. We applied mechanical strain of 0μ, 5333 μ to GPX1-overexpressing human uterosacral ligament fibroblasts (hUSLFs) isolated from menopausal women without POP respectively for 4 hours, in order to investigate the changes of cell apoptosis, oxidative status and ECM metabolism when cytomechanics model loaded on GPX1-overexpressing hUSLFs. Comparing with the non-transfection and mock-vehicle groups, we found that GPX1 not only protects hUSLFs from cell apoptosis, oxidative damage, but also improves the remodeling of ECM induced by mechanical stimulation. These results suggested that mechanical strain caused abnormalities of ECM metabolism via OS pathway in hUSLFs, which was involved in the pathogenesis of POP, and that GPx1 played a significant role in regulating mechanical strain induced POP.

Tumor suppressor in lung cancer 1 (TSLC1) is a tumor suppressor gene that encodes a member of the immunoglobulin superfamily, which is involved in the progression of some types of cancer. Several studies have shown that loss of TSLC1 expression is strongly correlated to methylation of the gene promoter, thus leading to poor prognosis in these cancers. However, the role of TSLC1 in cutaneous melanoma (CM) has not been examined. The purpose of this study was to understand the molecular mechanisms and clinical significance of TSLC1 inactivation in CM. The expression and promoter methylation of TSLC1 were analyzed in 120 CMs. TSLC1 expression was examined by immunohistochemistry, whereas its methylation status was determined by methylation-specific PCR. TSLC1 expression was lost in 84 of 120 (70%) CMs; 36 (30%) CMs were scored as positive for TSLC1 protein expression. The TSLC1 promoter was methylated in 58 (48.33%) of 120 CMs. The incidence of the loss of expression and methylation of TSLC1 significantly increased as the tumor stage advanced (P=0.032 and 0.0021, respectively). Furthermore, in CM, disease-related survival was significantly shorter in patients with tumors losing TSLC1 or harboring methylated TSLC1 (P=0.0003 and 0.0329, respectively). The epigenetic silencing of TSLC1 through methylation is an important event in the pathogenesis of CM, and TSLC1 provides an indicator for poor prognosis.

"Add-back" therapy, based on the GnRH-a dose, does not reduce the efficacy of using GNRH-a for the management of endometriosis. "Add-back" therapy reduced the occurrence of side effects that can occur with GnRH-a therapy alone, such as osteoporosis and menopausal syndrome. There were no statistically significant differences when comparing the effectiveness of a variety of "add-back" regimens to each other.