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Human embryonic stem cells (hESCs) are pluripotent and capable of undergoing multilineage differentiation into highly specialized cells including pancreatic islet cells. Thus, they represent a novel alternative source for targeted therapies and regenerative medicine for diabetes. Significant progress has been made in differentiating hESCs toward pancreatic lineages. One approach is based on the similarities of pancreatic β cell and neuroepithelial development. Nestin-positive cells are selected as pancreatic β cell precursors and further differentiated to secrete insulin. The other approach is based on our knowledge of developmental biology in which the differentiation protocol sequentially reproduces the individual steps that are known in normal β cell ontogenesis during fetal pancreatic development. In the present study, the hESC cell line PKU1.1 was induced to differentiate into insulin-producing cells (IPCs) using both protocols. The differentiation process was dynamically investigated and the similarities and differences between both strategies were explored. Our results show that IPCs can be successfully induced with both differentiation strategies. The resulting IPCs from both protocols shared many similar features with pancreatic islet cells, but not mature, functional β cells. However, these differently-derived IPC cell types displayed specific morphologies and different expression levels of pancreatic islet development-related markers. These data not only broaden our outlook on hESC differentiation into IPCs, but also extend the full potential of these processes for regenerative medicine in diabetes.

IntroductionThe aim was to compare the efficacy of long-acting and short-acting gonadotropin-releasing hormone (GnRH) agonists by long protocol on embryo quality, endometrial thickness and pregnancy rate in in vitro fertilization.Material and methodsIn this retrospective study, long-term pituitary downregulation, achieved with long- and short-acting GnRH agonists (GnRHa), was performed for patients undergoing in vitro fertilization (n = 175).ResultsThere were no significant differences between the long and short-acting GnRH group (63.16% vs. 66.26%, p > 0.05), and the secondary and primary infertility group (63.47% vs. 66.86%, p > 0.05) in embryo quality. Logistic regression analysis showed that type of infertility and endometrial thickness were significantly associated with pregnancy outcome. Patients in the long-acting GnRHa group had a thicker endometrium on the day of human chorionic gonadotrophin (hCG) administration (10.79 ±2.62 mm vs. 9.64 ±1.97 mm, p < 0.01), lower serum luteinizing hormone (LH) concentration (1.21 ±1.13 vs. 2.53 ±3.39) and a higher pregnancy rate (59.60% vs. 43.42%, p < 0.05) than those of patients in the short-acting GnRHa group.ConclusionsThis work suggests that types of agonist protocol and infertility may not affect embryo quality. Type of infertility and endometrial thickness may be positive predictors for clinical pregnancy, but the key finding is that the long-acting GnRHa protocol may be an effective method of improving endometrial thickness, endometrial receptivity and pregnancy rate in in vitro fertilization.

Background: To investigate the effectiveness of the GnRH-a ultra-long protocol, GnRH-a long protocol, and GnRH-a short protocol used in in vitro fertilization-embryo transfer (IVF-ET) in infertile women with endometriosis.

The purpose of this study was to investigate whether fertilization failure after in vitro fertilization could be explained by polymorphisms in MT-ATP6 and MT-CYB genes. We performed a prospective comparative study of 111 fresh IVF cycles in Han Chinese between July 2011 and February 2013. Human sperm mitochondrial DNA (mtDNA) variants in the MT-CYB and MT-ATP6 genes were screened by polymerase chain reaction (PCR) and direct sequencing. Forty-six couples had low fertilization rates (< or =30%) or total fertilization failure, and 65 controls with normal fertilization. One unreported point mutation (A15472G) was found in this study. There were 7 and 3 polymorphic sites in the MT-ATP6 and MT-CYB, respectively. Interestingly, the frequencies of points 8701 and 15301 homozygous variants in study group were significantly higher than those in control group. However, the frequencies of the points 8701, 9075 and 15,301 heterozygous variants in study group were significantly lower than those in control group (4.35% versus 16.92%, 15.22% versus 32.31% and 6.52% versus 33.84%, respectively, p < 0.05). In addition, the frequency in subjects harboring A8701G and G15301A variants in study group was significantly higher than that in control group (63.04% versus 33.85%, p < 0.05). This study suggests that, in part, polymorphisms in the MT-ATP6 and MT-CYB genes may contribute to the unexpected fertilization failure.

Leydig cells are essential for male reproductive development throughout life. Production of androgens as well as intermediate steroids is tightly regulated. Although microRNAs (miRNAs) are suggested to play important roles in spermatogenesis, little is currently known regarding the regulation of steroidogenesis by miRNAs in Leydig cells. Here, we found that miR-150 was predominantly expressed in Leydig cells within mouse testis. Therefore, we determined steroidogenesis of the Leydig cells in which miR-150 was knocked down or overexpressed using miR-150 antagomir and agomir, respectively. Compared with negative control group, a significant increase of STAR expression was observed in miR-150 antagomir-treated Leydig cells. Conversely, STAR expression was significantly reduced in miR-150 agomir-transfected Leydig cells. Production of sex-steroid precursors and testosterone of Leydig cells was also negatively controlled by miR-150. We further identified as a target of miR-150 using luciferase reporter assay. Finally, we confirmed that miR-150 was necessary for steroidogenesis and spermatogenesis via intratesticular injection of miR-150 antagomir or agomir. Taken together, our studies suggest that miR-150 negatively regulates the expression of STAR and steroidogenesis of Leydig cells in mice.

Several approaches have been used to encourage the differentiation of cardiomyocytes from human embryonic stem cells. However, the differentiation efficiency is low, and appropriate culture protocols are needed to produce adequate numbers of cardiomyocytes for therapeutic cell transplantation. This study investigated the effects of serum on cardiomyocyte differentiation in suspension culture medium during embryoid body (EB) formation by human embryonic stem cells. The addition of ascorbic acid, dimethylsulfoxide and 5-aza-2'-deoxycytidine during days 5-7 at the EB-forming stage resulted in an increase in the numbers of rhythmically contracting clusters of derived cardiomyocytes. Treatment with 0.1 mmol L(-1) ascorbic acid alone, or more notably in combination with 10 micromol L(-1) 5-aza-2'-deoxycytidine, induced the formation of beating cells within EBs. Most of the beating clusters had spontaneous contraction rates similar to those found in human adults, and their contractile activity lasted for up to 194 days.

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