Survivin is essential for fertile egg production and female fertility in mice

Survivin is the smallest member of the inhibitor of apoptosis protein (IAP) family and acts as a bifunctional protein involved in mitosis regulation and apoptosis inhibition. To identify the physiological role of Survivin in female reproduction, we selectively disrupted Survivin expression in oocytes and granulosa cells (GCs), two major cell types in the ovary, by two different Cre-Loxp conditional knockout systems, and found that both led to defective female fertility. Survivin deletion in oocytes did not affect oocyte growth, viability and ovulation, but caused tetraploid egg production and thus female infertility. Further exploration revealed that Survivin was essential for regulating proper meiotic spindle organization, spindle assembly checkpoint activity, timely metaphase-to-anaphase transition and cytokinesis. Mutant mice with Survivin depleted in GCs showed reduced ovulation and subfertility, caused by defective follicular growth, increased follicular atresia and impaired luteinization. These findings suggest that Survivin has an important role in regulating folliculogenesis and oogenesis in the adult mouse ovary.

Evaluation of the expression and role of IGF pathway biomarkers in human sarcomas

Recent studies have shown that insulin-like growth factor (IGF) signaling components have been involved in the pathogenesis and progression of different types of sarcomas. There has been some evidence to indicate the differential expression of IGF2 and insulin-like growth factor 1 receptor (IGF1R) in human sarcomas. The present study utilized immunohistochemistry (IHC) and in situ hybridization (ISH) to determine the expression of IGF2 and IGF1R in eighty-two cases of human sarcoma specimens and eight cases of non-tumor tissue (NTT). IGF2/IGF1R signaling was blocked by recombinant adenovirus-mediated IGF1R small hairpin RNA (shIGF1R), which was used to transfect into human osteosarcoma (OS) MG-63 cells. The expression of IGF2, IGF1R, matrix metallopeptidase-2 (MMP-2) and MMP-9 was detected by Real-time PCR. Cell migration was evaluated by wound healing assay. As a consequence, the expression of IGF1R and IGF2 was found in human OS with higher strong reactivity rate compared with the NTT (85.0 percent vs 50.0 percent, P=0.022; 95.0 percent vs 100.0 percent, P=0.042), elevating with the ascending order of tumor malignancy. Also, IGF1R had differential expression in different types of sarcomas (P=0.002), while IGF2 had no significant difference (P=0.105). Targeted blockade of IGF2/IGF1R signaling decreased the expression of IGF2, IGF1R, and MMP-2/-9, and diminished the migration capabilities of MG-63 cells. In conclusion, IGF1R is differentially-expressed in different types of human sarcomas, and targeted blockade of IGF1R pathway may inhibit human OS migration through down-regulation of MMP-2/-9 expression. IGF1R pathway may represent a significant therapeutic modality for the treatment of sarcomas.

Incidence and risk of hemorrhagic events with vascular endothelial growth factor receptor tyrosine-kinase inhibitors: an up-to-date meta-analysis of 27 randomized controlled trials

BACKGROUND

We aimed at determining the overall incidence and risk of hemorrhagic events associated with vascular endothelial growth factor receptor-tyrosine-kinase inhibitors (VEGFR-TKIs).

METHODS

We searched PubMed, EMBASE and Cochrane library databases for relevant prospective, randomized controlled trials (RCTs). Statistical analyses were conducted to calculate the summary incidence, relative risks (RRs) and 95% confidence intervals (CIs) by using either random-effects or fixed-effects models according to the heterogeneity of included studies.

RESULTS

The overall incidence of all-grade and high-grade hemorrhagic events was 9.1% (95% CI: 6.8-12.1%) and 1.3% (95% CI 0.8% to 2.1%), respectively. And the use of VEGFR-TKIs was associated with an increased risk of hemorrhagic events, with a relative risk (RR) of 1.67 (95% CI 1.19-2.33, P = 0.003), but not for high-grade hemorrhagic events (RR 1.23, 95% CI 0.86-1.77, P = 0.25). The risk of developing all-grade hemorrhagic events varied significantly with tumor types (P < 0.001) and different VEGFR-TKIs (P < 0.001). Additionally, the most common causes of all-grade hemorrhagic events were hemoptysis (48.6%) and epistaxis (20.7%), while hemoptysis (41.8%) and CNS hemorrhage (13.4%) was the most common cause of high-grade hemorrhagic events.

CONCLUSIONS

While the use of VEGFR-TKIs is associated with a significantly increased risk of developing hemorrhagic events in cancer patients, this is primarily for lower grade events.

Germline-specific and sexually dimorphic expression of a dead end gene homologue in turbot (Scophthalmus maximus)

Germ cells are indispensable for gonadal development and fertility. However, the physiological mechanisms regulating germ cell development in marine fish are poorly understood due to a lack of germ cell markers. The dead end (dnd) gene is a vertebrate-specific component of germplasm crucial for primordial germ cells (PGCs) migration and development in teleosts. In this study, we identified a dnd homologue (Smdnd) in turbot (Scophthalmus maximus) and investigated its expression pattern during embryogenesis and gonadal development. The deduced amino acid sequence of Smdnd shared several conserved motifs of Dnd homologues as well as high identity to other Dnd proteins. Phylogenetic analysis revealed that the SmDnd was closely related to its teleost counterparts. Reverse transcription polymerase chain reaction (RT-PCR) and in situ hybridization revealed that Smdnd transcripts could be exclusively detected in germ cells, including presumptive PGC and adult male and female germ cells. In addition, an interesting sexually dimorphic expression of Smdnd during gonadal development was observed by real-time PCR. Female turbot showed greater (P < 0.05) Smdnd expression than male before sex maturation. This difference reduced gradually due to the upregulation of Smdnd in the male during the period corresponding to spermatogonia proliferation and meiosis. These results indicate that Smdnd can be used as a germ cell marker in turbot. In addition, the temporal and sex differences in Smdnd expression indicate that this gene may play different roles in gonadal development in both sexes.

Panax notoginseng saponins improve the erectile dysfunction in diabetic rats by protecting the endothelial function of the penile corpus cavernosum

Diabetes mellitus (DM)-associated ED is predominantly due to neurovascular dysfunction mediated by nitric oxide (NO) suppression. Panax notoginseng saponins (PNS) are widely used for treating cardiovascular disease in China. The aim of this study was to evaluate the effects of PNS on penile erection and corpus cavernosum tissues in rats with diabetes-associated ED. Four weeks after PNS treatment, erectile function was assessed by intracavernous pressure (ICP) and mean arterial pressure (MAP) measurements. The level of NO, cyclic guanosine monophosphate (cGMP) and advanced glycation end products (AGEs) in cavernous tissue were assessed. Immunohistochemical staining and TUNEL (terminal deoxynucleotidyl transferase dUTP nick end labeling) were performed for detecting endothelial NO synthase (eNOS) and apoptosis, respectively. The results show that ICP/MAP ratio was significantly increased in high-dose (150 mg kg(-1) per day) PNS-treated group compared with the diabetic ED untreated group (DM group). Compared with the untreated group, the expression of eNOS and the levels of NO and cGMP were increased in the PNS-treated groups. Moreover, apoptosis was markedly decreased in the group that received 150 mg kg(-1) per day of PNS. These results suggest that PNS may be used for improving the ED in diabetic rats via the NO/cGMP pathway and restores the function of endothelium in corpus cavernosum.

Sox2 targets cyclinE, p27 and survivin to regulate androgen-independent human prostate cancer cell proliferation and apoptosis

OBJECTIVES

Sox2 is a major transcription factor and the transforming growth factor-α (TGF-α)/EGFR autocrine loop is a hallmark of prostate cancer progression. In this study, we have evaluated the effects and potential mechanisms of Sox2 on cell proliferation and apoptosis, and investigated effects of TGF-α on expression of Sox2 on androgen-independent human prostate cancer cells.

MATERIALS AND METHODS

Expression of Sox2 has been determined by RT-PCR, western blot analysis and immunocytochemistry, using RNAi and over-expression strategy to study functions of Sox2 in DU145 and PC-3 cells. Changes in level of proliferation, cell cycle and apoptosis profiles were measured by MTT, colony-forming, bromodeoxyuridine incorporation assays, cell cycle and annexin V analysis.

RESULTS

Sox2 was expressed in six human prostate cancer cell lines, and its inhibition reduced cell proliferation and induced apoptosis in DU145 cells. We have shown that knock-down of Sox2 inhibited G(1) to S phase transition concomitantly with down-regulation of cyclin E and up-regulation of p27 proteins. Conversely, over-expression of Sox2 led to the opposite effect in PC-3 cells but its inhibition induced apoptosis by down-regulation of survivin in DU145 cells. We also found that TGF-α up-regulated Sox2 and survivin protein expression via the EGFR/PI3K/AKT pathway.

CONCLUSIONS

Sox2 expression is necessary for cell proliferation and evasion of apoptosis in prostate cancer cells and TGF-α could regulate Sox2 and survivin expression by activating the EGFR/PI3K/AKT pathway.

[Temporal bone surgery. Surgical sequelae and complications]

The saying "no surgery, no surgical complications" is certainly true for all specialties. Three categories of undesired events may occur following surgery: surgical sequelae, failure to cure and complications. A critical self-analysis of surgical complications often reveals that these arise in vexing fashion according to Murphy's law, i.e. "what can go wrong, will go wrong". Incomplete preoperative evaluation, insufficient exposure of the surgical field, failure to identify surgical landmarks and misjudgment of the patient's preoperative complaints may culminate in an undesired surgical outcome. Modern preoperative radiology, the possibilities of actual or even virtual temporal bone drilling in the laboratory and the surgeon's level of experience all ensure the relative rarity of relevant surgical complications in otology.

Association among serum uric acid, cardiovascular risk, and arterial stiffness: a cross-sectional study in She ethnic minority group of Fujian Province in China

OBJECTIVES

To investigate the association between serum uric acid levels, cardiovascular risk, and arterial stiffness in She ethnic minority in South China's Fujian Province.

METHODS

5109 participants aged 20-79 yr were enrolled in analysis. Tpeak-Tend interval (Tp-e), QT interval, and height of the R wave in lead aVL (aVLR) were measured on 12-lead electrocardiogram (ECG), and Minnesota code-indicated major abnormal ECG MA-ECG was used as a risk indicator of cardiovascular disease. Arterial stiffness was assessed by brachial-ankle pulse wave velocity (baPWV).

RESULTS

Longer Tp-e interval, greater Tp-e/QT ratio, and higher aVLR were observed in the highest quartile of uric acid level. The incidence of MA-ECG was gradually increased from lowest to highest quartile of serum uric acid in males (p for trend <0.01). After adjusting traditional cardiovascular risk factors, multivariate analysis revealed that the fourth quartile of serum uric acid level was independently associated with MA-ECG in males [odds ratios (OR) (95% confidence interval): 2.129 (1.376-3.295)] but not in females. Serum uric acid was also associated with abnormal baPWV, when adjusted for atherogenic confounders. Compared with the lowest serum uric acid quartile, the OR (95% confidence interval) of the second, third, and fourth quartile were 1.920 (1.246-2.957), 1.650 (1.064-2.558), and 2.501 (1.600-3.908) in males.

CONCLUSION

Among China's She ethnic minority, uric acid level was independently related to arterial stiffness assessed by baPWV in both genders. The evaluation of uric acid level was related to higher cardiovascular risk in males but not in females.

Germ cells and fertilization differences among Japanese flounder Paralichthys olivaceus, summer flounder Paralichthys dentatus and their first and second generations

The morphology of gametes and the fertilization biology of Japanese flounder Paralichthys olivaceus (Po), summer flounder Paralichthys dentatus (Pd) and their hybrids were examined. Multiple generations (two hybrids: Po♀× Pd♂ (F1) and Pd♀× Po♂; two backcrosses: F1♀× Po♂ and F1♀× Pd♂) were obtained by artificial insemination. Comparison of egg ultrastructure among Po, Pd and F1 showed the morphology of micropyle region and the distribution density of pores were species specific. There were c. 100-200 accessory openings around the micropyle in Po, but not in Pd and F1. The zona radiata thickness and number of parallel bands were similar between F1 and Po, which were different from Pd. Comparison of spermatozoa ultrastructure revealed a close relationship between Po and Pd. Cytologically, the six crosses obeyed normal fertilization and cleavage processes, and only one male pronucleus was observed in a fertilized egg, indicating a monospermic fertilization pattern. Analysis of the time distribution from fertilization to first cleavage revealed an obvious delay at pronucleus fusion in the Pd × Po cross. The delay might indicate some cytoplasmic-nuclear incompatibility during the process of fertilization.

Protective effect of Puerarin on β-amyloid-induced neurotoxicity in rat hippocampal neurons

Puerarin (CAS Number 3681-99-0), a major isoflavone glycoside purified from Pueraria lobata, was reported to possess antioxidative and estrogen-like biological activities. Recent studies showed that puerarin protects different cell types from damage caused by a variety of toxic stimuli. In the present study, we investigated the neuroprotective effect of puerarin against Aβ25-35-induced neurotoxicity in cultured hippocampal neurons, as well as the underlying mechanism(s). Following exposure of cells to Aβ25-35, cell survival and glutathione peroxidase (GSH-Px) and catalase (CAT) activities were reduced while production of reactive oxygen species (ROS) was increased. Preincubation of the cells with puerarin prior to Aβ25-35 exposure increased cell survival and GSH-Px and CAT activities and decreased ROS production. It was previously shown that overactivation of glycogen synthase kinase-3β (GSK-3β) is implicated in Aβ-induced cell death. In this study, Aβ25-35 treatment is found to increase GSK-3β activity and pretreatment with puerarin preventesAβ-induced activation of GSK-3β based on Western blot analysis. In addition, puerarin is shown to activate protein kinase B (PKB)/Akt, an important upstream kinase of GSK-3β, possibly promoting subsequent GSK-3β inhibition. Our data suggest that puerarin attenuates cell death induced by Aβ25-35 via various mechanisms, which might be beneficial for the treatment of Alzheimer's disease.