Kyu-Sup Lee

Preparation and properties of UV‐curable polyurethane acrylates

UV-curable polyurethane (PU) acrylates have been synthesized from polypropylene glycol (PPG), isophoron diisocyanate (IPDI), and three types of reactive diluents, i.e., 2-hydroxyethylacrylate (HEA), tripropyleneglycol diacrylate (TPGDA), and trimethylolpropane triacrylate (TMPTA). The effects of soft segment length, type, and concentration of reactive diluent on the mechanical and dynamic mechanical properties have been determined. When the soft segment length was short (750) tensile strength (σb) decreased, and elongation at break (ϵb) generally increased with increasing HEA concentration, due respectively to the inferior strength of HEA homopolymer, and increased molecular weight between crosslinks (Mc). Initial modulus (E) and σb increase and elongation at break (ϵb) decreased with the increase of TPGDA concentration, and the effect was more pronounced as the soft segment length decreased. The hardness and σb increase with diluent concentration in PPG 2000-based materials was more pronounced with higher functionality diluent, due to the increased crosslinking density. The lower temperature glass transition peak of PU was not influenced by the TPGDA incorporation, whereas the higher temperature one moved toward still higher temperature. This was interpreted in terms of possible compatibility of hard segments and acrylates due to their similar polarity and hydrogen bonding.

Curcumin Attenuates TNF‐α‐induced Expression of Intercellular Adhesion Molecule‐1, Vascular Cell Adhesion Molecule‐1 and Proinflammatory Cytokines in Human Endometriotic Stromal Cells

Curcumin, a naturally occurring polyphenolic compound from Curcuma longa, has long been used in folk medicine as an antiinflammatory remedy in Asian countries. Endometriosis is a chronic gynecological inflammatory disorder in which immune system deregulation may play a role in its initiation and progression. A number of mediators, including cell adhesion molecules such as intercellular adhesion molecule‐1 (ICAM‐1) and vascular cell adhesion molecule‐1 (VCAM‐1); proinflammatory cytokines such as tumour necrosis factor‐α (TNF‐α), interleukin‐1 (IL‐1), IL‐6 and IL‐8; and chemokines such as monocyte chemotactic protein‐1 (MCP‐1), play key roles in the pathogenesis of endometriosis. The aim of our study was to explore the effect of curcumin on the expression of these critical molecules in human ectopic endometriotic stromal cells isolated from women with endometriosis. Endometriotic stromal cells treated with curcumin showed marked suppression of TNF‐α‐induced mRNA expression of ICAM‐1 and VCAM‐1. Curcumin treatment also significantly decreased the TNF‐α‐induced cell surface and total protein expression of ICAM‐1 and VCAM‐1 in a dose‐dependent manner. In addition, treatment of endometriotic stromal cells with curcumin markedly inhibited TNF‐α‐induced secretion of IL‐6, IL‐8 and MCP‐1. Furthermore, curcumin inhibited the activation of transcription factor NF‐κB, a key regulator of inflammation, in human endometriotic stromal cells. These findings suggest that curcumin may have potential therapeutic uses in the prevention and treatment of endometriosis. Copyright

Role of leptin in improvement of oocyte quality by regulation of ovarian angiogenesis.

Ovarian angiogenesis plays an important role in folliculogenesis. An active blood supply via ovarian angiogenesis seems to be essential for the induction of oocytes with good quality. Leptin is an angiogenic factor which regulates VEGF expression. This study was aimed to investigate whether leptin administration during superovulation influences ovarian response, oocyte quality and VEGF expression in the ovary using different aged mice model. C57BL inbred female mice of two age groups (18-21, and 29-31 weeks) were superovulated by intraperitoneal co-injection with 5IU of pregnant mares serum gonadotropin (PMSG) supplemented with recombinant mouse leptin at various doses (0.01, 0.1, 1 microg), followed by injection with 5IU of human chorionic gonadotropin (hCG) approximately 48 h later. Then, the mice were immediately paired with an individual male. The control group was superovulated with PMSG and hCG without leptin. After 18 h, one-cell embryos were flushed and cultured for 4 days. Proteins were extracted from ovaries removed just after the retrieval of one-cell embryos and VEGF expression was examined by Western blot. Treatment of 0.1 microg and 1 microg leptin significantly increased the number and embryo development rate of one-cell embryos retrieved compared to the control group. This positive effect of leptin was more significant with advancing female age. Ovarian VEGF expression was also significantly increased in 0.1 and 1 microg leptin-treated groups compared to the control group in both age groups (P<0.05). Our present study showed that leptin administration with gonadotropins during superovulation in aged mice increased the ovarian response, developmental competence of oocytes and ovarian VEGF expression. This research may have potential clinical implications in the treatment of age-related decline of fertility.

Decreased expressions of vascular endothelial growth factor and visfatin in the placental bed of pregnancies complicated by preeclampsia

Aim:  The aim of the present study was to examine the expression of vascular endothelial growth factor (VEGF) and visfatin in the third trimester placental bed of pregnancies with and without preeclampsia (PE).

Administration of visfatin during superovulation improves developmental competency of oocytes and fertility potential in aged female mice

OBJECTIVE To examine whether visfatin administration during superovulation improves ovarian response, developmental competence of oocytes, and fertility in aged female mice. DESIGN Controlled experimental study. SETTING University hospital. ANIMAL(S) Two groups of differently aged C57BL female mice (6-11 and 26-31 weeks). INTERVENTION(S) Female mice were coinjected intraperitoneally with 5 IU pregnant mares serum gonadotropin (PMSG) and visfatin of various doses (0-500 ng/mL), followed by 5 IU human chorionic gonadotropin (hCG) injection 48 hours later. Then the mice were immediately mated with an individual male. After 18 hours zygotes were cultured, and expression of ovarian visfatin and vascular endothelial growth factor (VEGF) was examined. Potential pregnancies of visfatin-administered aged female mice were monitored for delivery of offspring. MAIN OUTCOME MEASURE(S) Number of zygotes retrieved, embryo developmental competency, fertility potential, ovarian visfatin and VEGF expression. RESULT(S) Ovarian visfatin expression was significantly decreased in the aged mice group compared with the young. Visfatin administration significantly increased embryo developmental rate and ovarian visfatin and VEGF expressions in the aged mice. Visfatin-administered aged mice delivered significantly higher numbers of offspring than controls. CONCLUSION(S) This study suggests that visfatin administration during superovulation plays an important role in regulating oocyte quality and can improve oocyte quality and fertility of aged female mice.

Hexane extract of aged black garlic reduces cell proliferation and attenuates the expression of ICAM-1 and VCAM‑1 in TNF-α-activated human endometrial stromal cells.

Increasing evidence indicates the potentially crucial roles of intercellular adhesion molecule-1 (ICAM-1) and vascular cell adhesion molecule-1 (VCAM-1) in the pathological process underlying endometriosis. The present study aimed to investigate the effects of a hexane extract of aged black garlic (HEABG) on the proliferation and expression of ICAM-1 and VCAM-1 in tumor necrosis factor-α (TNF-α)-activated human endometrial stromal cells (HESCs) isolated from patients with endometriosis. HESCs were isolated from endometriotic tissues obtained from women with advanced endometriosis who underwent laparoscopic surgery for ovarian endometrioma (n=18). Cell proliferation and cell cycle analysis were assessed by WST-1 assay and flow cytometry, respectively. The expression of ICAM-1 and VCAM-1 was measured by flow cytometry, immunofluorescence staining, immunoblotting and quantitative reverse transcriptase-PCR. The secretion of interleukin-6 (IL-6) was determined by enzyme-linked immunosorbent assay (ELISA). The activation of nuclear factor-κB (NF-κB) and activator protein-1 (AP-1) was detected by electrophoretic mobility shift assay (EMSA) and the activation of c-Jun N-terminal kinase (JNK), extracellular signal-regulated kinase (ERK) and p38 MAPK was analyzed by immunoblotting. Cell proliferation and cell cycle progression were significantly suppressed by HEABG in the TNF-α-induced HESCs through the inhibition of the ERK and JNK signaling pathways. Remarkably, the treatment of the HESCs with HEABG potently suppressed the TNF-α-induced ICAM-1 and VCAM-1 transcript and protein expression by inhibiting the activation of NF-κB and AP-1 transcription factors. Our results suggest that HEABG may be effective in the prevention and treatment of endometriosis in humans.

ORIGINAL ARTICLE: Effects of Peritoneal Fluid from Endometriosis Patients on Interferon‐γ‐Induced Protein‐10 (CXCL10) and Interleukin‐8 (CXCL8) Released by Neutrophils and CD4+ T Cells

Problem  Intraperitoneal immuno‐inflammatory changes may be associated with the pathogenesis of endometriosis. We evaluated the effects of peritoneal fluid obtained from patients with endometriosis (ePF) on the release of interferon‐γ‐induced protein‐10 (IP‐10/CXCL10) and interleukin‐8 (IL‐8/CXCL8) by neutrophils, CD4+ T cells, and monocytes.

Effects of 17β‐estradiol on the release of monocyte chemotactic protein‐1 and MAPK activity in monocytes stimulated with peritoneal fluid from endometriosis patients

Aim:  Hormones and inflammation have been implicated in the pathological process of endometriosis; therefore, we investigated the combined effects of 17β‐estradiol (E2) and peritoneal fluid obtained from patients with endometriosis (ePF) or a control peritoneal fluid (cPF) obtained from patients without endometriosis on the release of monocyte chemotactic protein‐1 (MCP‐1) by monocytes and the role of signaling pathways.

Estrogen administration during superovulation increases oocyte quality and expressions of vascular endothelial growth factor and nitric oxide synthase in the ovary

Aims:  This study investigated whether estrogen administration during superovulation enhances oocyte quality using a mice model. We also investigated whether this estrogen treatment regulates the expressions of angiogenic factors, such as vascular endothelial growth factor (VEGF) and endothelial nitric oxide synthase (eNOS), in the ovary.

Effects of letrozole on proliferation and apoptosis in cultured leiomyoma cells treated with prostaglandin E2

OBJECTIVE The objective was to determine the direct effect of letrozole on the proliferation and apoptosis of cultured leiomyoma cells co-treated with prostaglandin E(2) (PGE(2)). STUDY DESIGN Leiomyoma cells were obtained from three groups of patients who had undergone hysterectomy due to leiomyoma. Percentages of antiproliferative cells were evaluated by the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay and apoptosis was assessed with sub-G1 cell counts by flow cytometry and Western blot analysis. RESULTS Combined treatment with 100 microM letrozole and 10 microM PGE(2) for 48 h resulted in a significantly lower viability rate (25.9+/-4.5%) and an increased cell death rate (31.6+/-4.4%) than groups treated with letrozole or PGE(2) alone. However, after adding 10nM estradiol to the combined treatment group, the cell viability rate was restored (75.1+/-7.7%) and the cell death rate was decreased (10.5+/-3.1%). Increased caspase-3 expression was found in the letrozole and PGE(2) combined treatment group, but not in the group in which estradiol was added. CONCLUSION The present results demonstrate that letrozole inhibits growth and induces apoptosis of leiomyoma cells by blocking the aromatase up-regulated by PGE(2) treatment. These findings support the need for further investigation of aromatase inhibitors as a medical treatment option in leiomyoma.