Shi-Wen Jiang

Morphological changes of placental syncytium and their implications for the pathogenesis of preeclampsia

Preeclampsia is a hypertensive disease that complicates many pregnancies, typically presenting with new-onset or worsening hypertension and proteinuria. It is well recognized that the placental syncytium plays a key role in the pathogenesis of preeclampsia. This review summarizes the findings pertaining to the structural alterations in the syncytium of preeclamptic placentas and analyzes their pathological implications for the development of preeclampsia. Changes in the trophoblastic lineage, including those in the proliferation of cytotrophoblasts, the formation of syncytiotrophoblast through cell fusion, cell apoptosis and syncytial deportation, are discussed in the context of preeclampsia. Extensive correlations are made between functional deficiencies and the alterations on the levels of gross anatomy, tissue histology, cellular events, ultrastructure, molecular pathways, and gene expression. Attention is given to the significance of dynamic changes in the syncytial turnover in preeclamptic placentas. Specifically, experimental evidences for the complex and obligatory role of syncytin-1 in cell fusion, cell-cycle regulation at the G1/S transition, and apoptosis through AIF-mediated pathway, are discussed in detail in the context of syncytium homeostasis. Finally, the recent observations on the aberrant fibrin deposition in the trophoblastic layer and the trophoblast immature phenotype in preeclamptic placentas and their potential pathogenic impact are also reviewed.

SET/PP2A system regulates androgen production in ovarian follicles in vitro

SET has multiple cell functions including nucleosome assembly, histone binding, transcription control, and cell apoptosis. In ovaries SET is predominantly expressed in theca cells and oocytes. In our study, SET overexpression in theca cells stimulated testosterone production whereas SET knockdown decreased testosterone production. Moreover, SET negatively regulated PP2A activity. Treatment with PP2A inhibitor okadaic acid (OA) led to increased testosterone synthesis, while treatment with PP2A activators resulted in the decreased testosterone synthesis. Furthermore, PP2A knockdown confirmed the key role of PP2A in the testosterone synthesis, and OA was able to block the AdH1-SiRNA/SET-mediated inhibition of testosterone production. The central role of PP2A in SET-mediated regulation of testosterone production was confirmed by the finding that SET promoted the lyase activity of P450c17 and that PP2A inhibited its lyase activity. Taken together, these results reveal a specific, SET-initiated, PP2A-mediated, pathway that leads to the increased lyase activity of P450c17 and testosterone biosynthesis.

Polymorphism of CAG and GGN repeats of androgen receptor gene in women with polycystic ovary syndrome

One characteristic of polycystic ovary syndrome (PCOS) is hyperandrogenism, which may be related to the activity of androgen receptor (AR). This study was designed to investigate the polymorphism of CAG and GGN repeats in the AR gene in women with PCOS. The frequency distributions of CAG and GGN repeat alleles, as well as their X-inactivation patterns, were compared between 76 age-matched normal women (control group) and 80 women with PCOS (PCOS group). The expression of AR mRNA in the ovarian tissues of seven patients with PCOS and five normal women was also tested using real-time quantitative PCR. It was found that PCOS patients had significantly higher frequency of longer GGN biallelic mean (29.8%) and X-weighted biallelic mean (33.3%) than controls (6.1% and 3.2%, respectively, P = 0.002, P = 0.003). The odds ratio of the long GGN repeat length (n > 16) before and after X-chromosome inactivation (XCI) in the PCOS group was significantly higher than in controls (P = 0.0001, P = 0.005). AR-GGN repeat mRNA expression was higher in the ovarian tissue of controls compared with PCOS patients (P = 0.022). In conclusion, the data suggest that the GGN repeat polymorphism in the AR gene is associated with PCOS.

Pathologic significance of SET/I2PP2A-mediated PP2A and non-PP2A pathways in polycystic ovary syndrome (PCOS).

SET (SE translocation, SET), a constitutive inhibitor of protein phosphatase 2A (PP2A), is a multifunctional oncoprotein involved in DNA replication, histone modification, nucleosome assembly, gene transcription and cell proliferation. It is widely expressed in human tissues including the gonadal system and brain. Intensive studies have shown that overexpressed SET plays an important role in the development of Alzheimers disease (AD), and may also contribute to the malignant transformation of breast and ovarian cancers. Recent studies indicated that through interaction with PP2A, SET may upregulate androgen biosynthesis and contribute to hyperandrogenism in polycystic ovary syndrome (PCOS) patients. This review article summarizes data concerning the SET expression in ovaries from PCOS and normal women, and analyzes the role/regulatory mechanism of SET for androgen biosynthesis in PCOS, as well as the significance of this action in the development of PCOS. The potential value of SET-triggered pathway as a therapeutic target and the application of anti-SET reagents for treating hyperandrogenism in PCOS patients are also discussed.

Zinc Finger and X-Linked Factor (ZFX) Binds to Human SET Transcript 2 Promoter and Transactivates SET Expression

SET (SE Translocation) protein carries out multiple functions including those for protein phosphatase 2A (PP2A) inhibition, histone modification, DNA repair, and gene regulation. SET overexpression has been detected in brain neurons of patients suffering Alzheimer’s disease, follicle theca cells of Polycystic Ovary Syndrome (PCOS) patients, and ovarian cancer cells, indicating that SET may play a pathological role for these disorders. SET transcript 2, produced by a specific promoter, represents a major transcript variant in different cell types. In this study, we characterized the transcriptional activation of human SET transcript 2 promoter in HeLa cells. Promoter deletion experiments and co-transfection assays indicated that ZFX, the Zinc finger and X-linked transcription factor, was able to transactivate the SET promoter. A proximal promoter region containing four ZFX-binding sites was found to be critical for the ZFX-mediated transactivation. Mutagenesis study indicated that the ZFX-binding site located the closest to the transcription start site accounted for most of the ZFX-mediated transactivity. Manipulation of ZFX levels by overexpression or siRNA knockdown confirmed the significance and specificity of the ZFX-mediated SET promoter activation. Chromatin immunoprecipitation results verified the binding of ZFX to its cognate sites in the SET promoter. These findings have led to identification of ZFX as an upstream factor regulating SET gene expression. More studies are required to define the in vivo significance of this mechanism, and specifically, its implication for several benign and malignant diseases related to SET dysregulation.

Physiopathological factors affecting the diagnostic value of serum HE4-test for gynecologic malignancies

ABSTRACT Introduction: Serum epididymis protein 4 (HE4) represents a useful biomarker for the management of ovarian cancer and endometrial cancer patients. However, HE4 levels are affected by many physiopathological conditions or disorders that should be taken into consideration for an efficient application of this biomarker. Areas covered: The review provides an up-to-date reference on the multiple physiopathological factors that cause fluctuation of HE4 serum levels, and evaluates their impact on HE4-test in clinical settings. Potential mechanisms underlying the regulation of HE4 expression are also discussed. The review is based on data from literature search of PubMed and the author’s opinions. Expert commentary: Studies have shown that physiopathological factors such as age, infection/inflammation, renal function, menopause and hormonal levels impose significant impacts on HE4 serum levels. HE4 amount shed into the circulation is related to HE4 expression and secretion by tumor as well as normal tissues, which is affected by cancer heterogeneity, vascular permeability, renal clearance and HE4 degradation. Investigation on interfering factors builds a basis for the construction of a quantitative logarithm for individualized application of HE4-test in clinical settings.

Effect of Hsp27 on early embryonic development in the mouse

Previous studies by this study group have showed that heat shock protein 27 (Hsp27), expressed in the oocyte of growing follicles, is down-regulated in polycystic ovary syndrome ovaries and that down-regulation of Hsp27 improves the maturation of mouse oocytes and increases early apoptosis of oocytes. In this study, the effect of Hsp27 on early embryo development in the mouse was observed. Following microinjection of AdCMV-Hsp27 or AdsiRNA-Hsp27 into the cytoplasm of mouse zygotes, blastocyst morphology was observed and cell apoptosis of blastocysts was detected by TUNEL. After culture in vitro for 96h, blastocysts were analysed for Hsp27 expression by real-time PCR and immunofluorescence. The blastocyst formation rate and embryo quality were evaluated. The expression of Hsp27 was significantly increased in embryos with Hsp27 overexpression (AdCMV-Hsp27), while it was significantly suppressed by 75% in embryos with the gene silenced (AdsiRNA-Hsp27; both P<0.05). Cell apoptosis in blastocysts, blastocyst formation rate and embryo quality were unaffected by Hsp27 overexpression or gene silencing. In conclusion, overexpression or down-regulation of Hsp27 in zygotes, as a single factor, does not significantly affect the subsequent embryonic development.

Oncogenic Role of SET/I2PP2A for Gynecologic Cancers

SET (SE translocation, SET) is an evolutionarily conserved gene broadly expressed in various human tissues, especially in the gonadal and neural system. As a multitasking protein, SET is involved in essential cell processes such as histone modification, chromatin remodeling, DNA repair, gene transcription, and androgen synthesis. Recent studies showed that SET is overexpressed in breast cancers, ovary cancers and a variety of other malignancies. The strong correlation between SET expression levels and survival of ovarian cancer patients, and SET-mediated activation of androgen synthesis, strongly indicated that this factor may play a significant role in gynecologic cancers. Here, we summarized data pertaining to the pathological implications of SET in tumorigenesis and cancer progression. We analyzed how SET, through the PP2A-dependent and PP2A-independent pathways, may regulate different cell functions. Potential interactions among these pathways and future studies on SETs oncogenic activities are also discussed.

Establishment of human-embryonic-stem-cell line from mosaic trisomy 9 embryo

OBJECTIVEnHuman-embryonic-stem-cell (hESC) lines derived from chromosomally or genetically abnormal embryos obtained following preimplantation genetic diagnosis are valuable in investigating genetic disorders.nnnMATERIALS AND METHODSnIn this study, a new hESC line, Center of Clinical Reproductive Medicine 8 (CCRM8) was established by isolation, culture, and passaging of the inner cell mass of mosaic trisomy 9 embryos.nnnRESULTSnA karyotype analysis showed that the hESC line possessed a euploid (46 chromosomes). The undifferentiated hESCs exhibited long-term proliferation capacity and expressed typical markers of OCT4, TRA-1-60, and TRA-1-81. In vitro embryoid-body (EB) formation, differentiation, and in vivo teratoma production confirmed the pluripotency of the hESC line. The data represented here are the first detailed report on the characterization and differentiation of one Chinese hESC line generated from mosaic trisomy 9 embryos.nnnCONCLUSIONnOur study showed that chromosomally aberrant embryos could generate a normal hESC line, which would be useful in investigating gene function and embryo development.

Knockdown of prohibitin expression promotes glucose metabolism in eutopic endometrial stromal cells from women with endometriosis

In this in-vitro study, the effect of prohibitin (PHB) on glucose metabolism in eutopic endometrial stromal cells from women with endometriosis was investigated. Endometrial stromal cells were isolated from endometrium in women with endometriosis, in women without endometriosis, or from endometrioma tissues. Glucose metabolic phenotype of stromal cells were examined in vitro. Quantitative polymerase chain reaction was used to measure the mRNA expression of glycolysis-related genes. Glucose consumption and lactate production were examined after knockdown of PHB expression in women with endometriosis with siRNA. In endometrioma tissue, significantly increased glucose consumption, lactate production and aberrant expression of glycolysis-related enzymes were found in women with endometriosis compared with women who do not have endometriosis (Pu2009<u20090.05 versus Pu2009<u20090.001). In women with endometriosis, PHB mRNA and protein were under-expressed in endometrioma tissue; in women without endometriosis, PHB mRNA and protein were over-expressed. Knockdown of PHB expression in women with endometriosis increased glucose consumption, although it had no effect on lactate production. This study suggests that aberrant expression of glycolysis-related enzymes in endometrioma tissue is associated with enhanced glycolytic metabolism. The malignant-like feature may be partially caused by low-expression of PHB gene in endometriotic stromal cells.