Genome-wide screen of promoter methylation analysis of ES cells and ES derived epidermal-like cells.

Embryonic stem cells (ESCs) are a population of pluripotent cells which can differentiate into different cell types. However, there are few reports with regard to differentiate ESCs into epidermal cells in vitro. In this study, we aimed to investigate differentially methylated promoters involved in process of differentiation from ESCs into epidermal-like cells (ELCs) induced by human amnion. We successfully induced ESCs into ELCs, which expressed the surface markers of CK19, CK15 and ß1-integrin. With MeDIP-chip arrays, we identified 3435 gene promoters to be differentially methylated, involving 894 HCP (high CpG-containing promoter), 974 ICP (intermediate CpG-containing promoter) and 1567 LCP (low CpG-containing promoter) among all the 17,500 DNA methylation regions of gene promoters in both ESCs and ELCs. Gene oncology and pathway analysis demonstrated that these genes were involved in all the three categories of GO enrichment analysis, including biological process, molecular function and cellular component. All these data suggested that embryonic stem cells can differentiate into epidermal-like cells and promoter methylation is of great importance in this process.

shRNA constructs targeting IGFBP-3 alleviate age related erectile dysfunction in the rat.

PURPOSE: We investigated whether injecting shRNA constructs targeting IGFBP-3 in the penis of old rats would improve erectile function. MATERIALS AND METHODS: The most validated IGFBP-3 shRNA plasmid vector (pGPU6/GFP/Neo-shIGFBP-3) was prepared and injected in penile corpus cavernosum tissue. A total of 30 old (age 24 months) male Sprague Dawley® rats were randomly divided into 3 groups, including 10 each that received phosphate buffered saline only (100 µl), pGPU6/GFP/Neo-shNC (100 µg) and the most validated plasmid constructs pGPU6/GFP/Neo-shIGFBP-3 (100 µg). At 4 weeks the erectile response was measured as intracavernous pressure. The percent of smooth muscle in corpus cavernosum tissue was evaluated. Nitric oxide synthase activity and the cGMP concentration in penile tissue were also analyzed. IGFBP-3 was estimated in penile tissue by Western blot, real-time reverse transcriptase-polymerase chain reaction and immunohistochemistry. RESULTS: pGPU6/GFP/Neo-shIGFBP-3 corrected the impaired erectile response in aged rats compared with the response in those injected with phosphate buffered saline and pGPU6/GFP/Neo-shNC (each p <0.01). The percent of cavernous smooth muscle was increased in the pGPU6/GFP/Neo-shIGFBP-3 group. Nitric oxide synthase activity and the cGMP concentration were also significantly increased in rats treated with pGPU6/GFP/Neo-shIGFBP-3. IGFBP-3 shRNA effectively reduced IGFBP-3 mRNA and protein expression in penile corpus cavernosum tissue. CONCLUSIONS: Decreasing IGFBP-3 expression by plasmid expressed shRNA improved erectile function in aged rats. The therapy may modulate smooth muscle integrity and increase the cGMP concentration. This may be a new direction for treating erectile dysfunction in clinical practice.

Derivation of human embryonic stem cell lines without any exogenous growth factors.

Human embryonic stem cell (hESC) lines are traditionally derived through immunosurgery. Their maintenance in culture requires the presence of mouse embryonic fibroblasts (MEFs) as feeder cells and media supplemented with basic fibroblast growth factor (bFGF) or other growth factors-both of which might introduce animal-derived culture components. The drawbacks associated with immunosurgery, MEF co-culture, and the cost of growth factors necessitate the exploration of a xeno-free method to maintain the self-renewal capacity of hESCs. Here, we describe an isolation method for the human inner cell mass (ICM), which was then cultured in the absence of exogenous growth factors and in the presence of human foreskin fibroblasts (HFFs) as feeder cells. Three hESC lines were obtained from poor-quality embryos by this near-xeno-free protocol. After culturing for more than 10 months, the hESCs retained normal morphology, expressed all expected cell surface markers, could differentiate to embryoid bodies upon culture in vitro, and formed teratomas in vivo. Furthermore, secretion of bFGF by HFFs was observed. In conclusion, this is the first study to describe an inexpensive, xeno-free culture system for the isolation and maintenance of hESCs that does not require bFGF supplementation.

[Insulin-like growth factor-1 gene therapy improves the levels of mRNA and protein of endothelial nitric oxide synthase in aging related erectile dysfunction in rats].

OBJECTIVE: To explore the effects of gene transfer of insulin like growth factor-1 (IGF-1) on the penis of senile rats and the altered levels of mRNA and protein of endothelial nitric oxide synthase (eNOS). METHODS: Ten young (4 months) and 20 senile (24 months) Sprague-Dawley male rats were selected. The senile rats were divided into 2 groups: phosphate buffer solution (PBS)-only (n = 10) and 100 µg IGF-1 plasmid treatment group (n = 10). After a 4-week injection of IGF-1, the responses of intracavernous pressure (ICP) with electrical stimulation to the cavernous nerve and systemic mean arterial pressure (MAP) were evaluated. In the control and transfected senile rats, the levels of eNOS mRNA and protein were examined by reverse transcription-polymerase chain reaction (RT-PCR) and Western blot respectively. RESULTS: The ICP/MAP and total ICP were significantly higher in the young control group versus the PBS-only group at Week 4 (P < 0.05). The ICP/MAP and total ICP were significantly higher in the young control group and the 100 µg IGF-1 treatment group versus the PBS-only group at Week 4 (P < 0.05). The levels of mRNA and protein of eNOS were higher in the 100 µg IGF-1 treatment group versus the PBS-only group at Week 4 (0.62 ± 0.16 vs 0.25 ± 0.08, 0.71 ± 0.19 vs 0.27 ± 0.09, both P < 0.05, respectively). CONCLUSION: The gene therapy of IGF-1 can ameliorate erectile functions and improve the levels of mRNA and protein of eNOS in senile rats.

[Relation between insulin resistance and insulin receptor gene methylation in the endometrium of patients with polycystic ovary syndrome].

OBJECTIVE: To study the relationship between insulin resistance and methylation of insulin receptor (INSR) gene in the endometrium of women with polycystic ovary syndrome (PCOS). METHODS: Based on the HOMA index, 35 patients with PCOS were divided into insulin resistant group (IR group, n=18) and non-resistant group (NIR group, n=18). The patients age, serum estriol, testosterone, FSH and LH, fasting insulin and fasting blood glucose were compared between the two groups. The endometrial samples were obtained from the patients to examine DNA methylation status of INSR gene in the endometrial cells using methylation-specific PCR. RESULTS: The BMI, WHR, fasting glucose, fasting insulin, and HOMA index differed significantly between the two groups (P<0.05). PCR analysis showed partial methylation in the promoter region of INSR gene in 13 samples in IR group and 11 samples in NIR group, without detection of full methylation of the INSR gene in either group. The methylation status showed no significant difference between the two groups (P=0.328). CONCLUSION: Partial methylation of the INSR gene occurs in the endometria of PCOS patients, but this study does not provide a strong evidence supporting the relationship between insulin resistance and INSR gene methylation in women with PCOS.

[Timing of pregnancy after surgery for tubal pregnancy].

OBJECTIVE: To investigate the outcome of pregnancy in women after surgical treatment of tubal pregnancy and measures to improve the rate of successful postoperative pregnancy. METHODS: A retrospective study was conducted among 424 women who underwent surgical treatment for tubal pregnancy between Jan 1999 and Jan 2004. All patients desiring a second pregnancy were followed up for 18-72 months for the outcome. Cumulative fertility and recurrence curve were compared and calculated by life-table. RESULTS: Of the 424 women with tubal pregnancy, 177 (41.7%) had intrauterine pregnancy after the operation, while 102 (24.1%) had recurrent ectopic pregnancy. Among the 177 women with intrauterine pregnancy, 85 (48.02%) became pregnant within 6 months after the operation, 133 (75.14%) within one year, and the cumulative intrauterine pregnancy rate approached 94.92% within 2 years. But among the 102 women with recurrent ectopic pregnancy, only 10 (9.8%) were pregnant within 6 months after the operation, and 49 (48.04%) within 18 months, with a cumulative ectopic pregnancy rate of 67.65%. CONCLUSION: For women receiving surgery for ectopic pregnancy, the chance for intrauterine pregnancy can be the greatest within 6 months after operation and reduced markedly after 2 years, when recurrent ectopic pregnancy can be likely. Early plans for pregnancy and hydrotubation following the surgery may prove beneficial for raising the chances for postoperative intrauterine pregnancy.

[Endometrial carcinoma in patients below 45 years of age: clinical analysis of 53 cases].

OBJECTIVE: To investigate the clinical characteristics of endometrial carcinoma in patients below 45 years of age. METHODS: The clinical data were collected from 53 patients with endometrial carcinoma below 45 years of age, who were divided into less than 40 year group (group A, 28 cases) and 40 to 45 year group (group B, 25 cases) and their clinical data were compared. RESULTS: A rate of 57.1% (16/28) of the patients in group A were infertile, and 78.5% (22/28) reported irregular menstruation. In group B, the infertility rate was 28.0% (7/25), and 48% (12/25) of the patients were obese, 56% (14/25) had abnormal vaginal bleeding, and 32% (8/25) had diabetes and hypertension. The two groups differed significantly in the infertility rate, number of pregnancies and deliveries and the incidences of obesity, hypertension and diabetes. The pathological classification, grade of differentiation, pathological staging, depth of myometrial invasion, and cervical infiltration status were comparable between the two groups (P>0.05). All the 53 patients received surgical interventions and follow. up for two years, during which 1 patients in group B had relapse. CONCLUSION: Patients with endometrial carcinoma at 40 years of age or below often have infertility, and those over 40 years are exposed to such high-risk factors as obesity, diabetes, and hypertension. Its major clinical symptom of endometrial carcinoma is menstrual disorders. The differentiation, pathological staging, pathological classification of the malignancy are not associated with age in patients below 45 years of age. Early diagnosis often warrants more favorable prognosis.