Downregulation of microRNA-126 in endothelial progenitor cells from diabetes patients, impairs their functional properties, via target gene Spred-1

Diabetes mellitus (DM) adversely affects the number and function of circulating endothelial progenitor cells (EPCs). Consequently, there is also a reduction in the repair mechanism of these cells, which is a critical and initiating factor in the development of diabetic vascular disease. The aim of the present study was to analyze miR expression profiles in EPCs from patients with DM and choose the most significantly regulated miR to study its possible role on EPC dysfunction and elucidate its mechanism of action. EPCs were collected from subjects with Type II DM and non-diabetic control subjects. Total RNA was harvested from EPCs, and a total of 5 candidate miRNAs were identified by microarray screening and were quantified by TaqMan real-time PCR. Lentiviral vectors expressing miR-126 and miR-126 inhibitor (anti-miR-126) were transfected into EPCs, and the EPC colony-forming capacity, proliferation activity, migratory activity, differentiation capacity, and apoptotic susceptibility were determined and Western Blotting and mRNA real-time PCR analyses were performed. To study the mechanisms, lentiviral vectors expressing Spred-1 and a short interfering RNA (siRNA) targeting Spred-1 were prepared. Five miRs were aberrantly downregulated in EPCs from DM patients. These miRs included miR-126, miR-21, miR-27a, miR-27b and miR-130a. Anti-miR-126 inhibited EPC proliferation, migration, and enhanced apoptosis. Restored miR-126 expression in EPCs from DM promoted EPC proliferation, migration, and inhibited EPC apoptosis ability. Despite this, miR-126 had no effect on EPC differentiation. miR-126 overexpression significantly downregulated Spred-1 in EPCs. The knockdown of Spred-1 expression in EPCs from DM promoted proliferation, migration, and inhibited apoptosis of the cells. The signal pathway of miR-126 effecting on EPCs is partially mediated through Ras/ERK/VEGF and PI3K/Akt/eNOS regulation. This study provides the first evidence that miR-126 is downregulated in EPCs from diabetic patients, and impairs EPCs-mediated function via its target, Spred-1, and through Ras/ERK/VEGF and PI3K/Akt/eNOS signal pathway.

Relationship between Serum Aminotransferase Levels and Metabolic Disorders in Northern China

BACKGROUND

Increasing evidence suggests an association between elevated serum aminotransferase levels and metabolic disorders (metabolic syndrome, hyperlipemia and diabetes mellitus). However, the significance of relatively low levels of aminotransferases in relation to metabolic disorders has not been fully investigated in the general population. We investigated the association between serum amiontransferase levels and metabolic disorders using data from a survey in Jilin province, China.

METHODS

In 2007, a survey was conducted throughout Jilin, China, covering both urban and rural areas. A total of 3835 people, 18 to 79 years old including 1761 men and 2074 women, underwent real-time ultrasonography, blood tests including aspartate aminotransferase and alanine aminotransferase, and had interviews with a structured questionnaire.

RESULTS

Serum aminotransferase levels within the normal range were associated with metabolic syndrome independent of age, occupation, cultural and educational level, income, body mass index, waist circumference, smoking, and alcohol intake. Compared with the lowest level (<20 IU/L), the adjusted odds ratios for ALT levels of 20-29, 30-39, 40-49 and >50 IU/L were 1.92, 2.50, 2.97, and 3.52 in men, and 1.38, 1.54, 3.06, and 2.62 in women, respectively. Near-normal serum aminotransferase levels associated with hyperlipemia, NAFLD, DM were also found in the study.

CONCLUSIONS

Normal to near-normal serum aminotransferase levels are associated with metabolic disorders. Serum ALT levels of 21-25 IU/L for men, and 17-22 IU/L for women are suggested as cutoff levels that detect metabolic disorders affecting the liver.

Noninvasive Evaluation of Cerebral Glioma Grade by Using Diffusion-Weighted Imaging-Guided Single-Voxel Proton Magnetic Resonance Spectroscopy

OBJECTIVE: To investigate the usefulness of diffusion-weighted imaging (DWI)-guided, single-voxel proton magnetic resonance spectroscopy (SVS) for preoperative evaluation of cerebral glioma grade. METHODS: For SVS, placement of volume-of-interest was guided by the minimal apparent diffusion coefficient value obtained from DWI. Spectral data for N-acetylaspartate (NAA), choline (Cho), and phosphocreatine (Cr) were analysed in 33 patients with primary gliomas. RESULTS: Cho/Cr and Cho/NAA ratios were significantly higher in high-grade than in low-grade gliomas; NAA/Cr ratios were significantly lower in high-grade than in low-grade gliomas. Receiver operating characteristic curve analysis demonstrated a threshold value of 2.01 for Cho/Cr for sensitivity, specificity, positive predictive and negative predictive values of 86.36%, 90.00%, 95.00% and 75.00%, respectively. Threshold values of 2.49 and 0.97 were obtained for Cho/NAA and NAA/Cr, respectively. Despite no significant difference in diagnostic accuracy between the metabolite ratios, diagnostic accuracy using the Cho/Cr ratio was slightly better than that of Cho/NAA or NAA/Cr. CONCLUSION: DWI-guided SVS has potential value for the preoperative prediction of glioma grade.

35 DYNAMICS OF PERICENTRIC REPETITIVE SEQUENCES IN PREIMPLANTATION RABBIT EMBRYOS UNDERLINES INADEQUATE SPATIO-TEMPORAL REORGANIZATION AFTER NUCLEAR TRANSFER

Nowadays, a critical question in the epigenetic field is how chromatin is organised within the cell nucleus and how it affects gene expression. In this study we hypothesise that nuclear structure could be involved in the control of gene expression during early rabbit embryonic development. We focused on pericentric/centric heterochromatin, a peculiar region within nuclei known to form higher-order chromatin structures. We therefore performed immunostaining of associated proteins (HP1 and CENP) as well as FISH (fluorescent in situ hybridization) with probes corresponding to these genomic regions. Fertilized embryos were collected from New Zealand white rabbit female, cultured in vitro and fixed at different developmental stages up to 16-cell. Nuclear transfer of rabbit fetal skin fibroblasts was performed by electrofusion and electroactivation (Chesne et al., 2002). Immunostaining experiments were performed as previously described (Martin et al., 2006) and FISH experiments were performed using DNA probes specific to Rsat I and Rsat II sequences (Ekes et al., 2004) according to our published protocol (Maalouf et al., 2010). Three-dimensional images were acquired by confocal laser microscopy (each group included 20 to 40 embryos) and then analysed through automated 3D image processes (according to Ballester et al., 2008; Pichugin et al., 2010). Briefly, after segmentation of the nuclei, immunostaining signals were analysed using an automatic threshold segmentation procedure and FISH spots distributions were analysed with the eroded volume fraction (EVF) method. In in vivo fertilized rabbit embryos, we observed that during the 1- and 2-cell cycles pericentric heterochromatin was dispersed throughout the embryonic nuclei. Large foci of pericentric heterochromatin then progressively appeared at the 4-cell stage and increased in frequency and size by the 8/16-cell stage [∼75% of the embryos, n = 40; i.e. the stage of major transcriptional activation also called MET (maternal to embryonic-transition)]. This suggested that dramatic aggregation of pericentric heterochromatin is associated to the onset of transcription. Interestingly, after nuclear transfer, the donor nuclear organisation was quickly reverted into an early embryonic dispersed form in most 1-cell embryos (80%, n = 35). Subsequently, a somatic-like nuclear reorganization with large heterochromatin foci was re-established in 86% of the 4-cell stage cloned embryos (n = 35). This pattern was similar to the one observed in fertilized embryos at MET; it also appeared one stage earlier (4-cell vs 8-cell). Coincidently, most cloned embryos stopped developing at that stage (85% of cleavage until the 4-cell but only 38% at morula, n = 173). Together, the results suggested that inadequate spatio-temporal reorganization of the donor nucleus could be deleterious during early development in rabbit clones. The present work was supported by INRA « Jeune Equipe » funding, the European CLONET (MRTN-CT-2006-035468) grant and the Ambassade de France en Chine.

Economic assessment of climate adaptation options for urban drainage design in Odense, Denmark

Climate change is likely to influence the water cycle by changing the precipitation patterns, in some cases leading to increased occurrences of precipitation extremes. Urban landscapes are vulnerable to such changes due to the concentrated population and socio-economic values in cities. Feasible adaptation requires better flood risk quantification and assessment of appropriate adaptation actions in term of costs and benefits. This paper presents an economic assessment of three prevailing climate adaptation options for urban drainage design in a Danish case study, Odense. A risk-based evaluation framework is used to give detailed insights of the physical and economic feasibilities of each option. Estimation of marginal benefits of adaptation options are carried out through a step-by-step cost-benefit analysis. The results are aimed at providing important information for decision making on how best to adapt to urban pluvial flooding due to climate impacts in cities.

P5-13-13: The Role of Topoisomerase IIa in Predicting Sensitivity to Anthracyclines in Breast Cancer Patients: A Meta-Analysis of Published Literatures

Topoisomerase IIα is not only a proliferation marker of tumor cells but also a target for anthracycline-based chemotherapy. Both in vitro and in vivo studies have shown that there was a relationship between topo IIα and chemosensitivity to anthracyclines, but the predictive role of topo IIα is still controversial in breast cancer patients. A meta-analysis based on published studies was performed with the aim of obtaining an accurate evaluation of the association between topo IIα and sensitivity to anthracycline-based chemotherapy. A total of 13 eligible studies including 2,633 cases and 2,118 controls were identified. Topo IIα was associated with sensitivity to anthracyclines in locally advanced breast cancer patients who received neoadjuvant chemotherapy (RR = 1.93, 95%CI: 1.27−2.94, P=0.002; RR =1.98, 95%CI: 1.37−2.86, P&lt;0.001). In early breast cancer patients who received anthracycline-based adjuvant chemotherapy compared with non-taxane-based polychemotherapy, amplification(HR = 0.64, 95%CI: 0.49−0.83, P=0.001; HR = 0.59, 95% CI: 0.35−1.01, P=0.056) or deletion (HR = 0.82, 95%CI: 0.67−1.00, P=0.051; HR =0.58, 95%CI: 0.35−0.97, P=0.036) of topo IIα was significantly associated with better RFS and OS. The subgroup analysis in the early breast cancer patients indicated that taxane could be an interference for evaluation of the predictive role of topo IIα. In summary, the present meta-analysis suggests that topo IIα is a predictive factor for breast cancer patients who received anthracycline-based chemotherapy. Larger and well-designed prospective studies are required to further evaluate the predictive role of topo IIα in clinical practice.

Citation Information: Cancer Res 2011;71(24 Suppl):Abstract nr P5-13-13.

P3-16-10: The Efficacy of Zoledronic Acid in Breast Cancer Adjuvant Therapy: A Meta-Analysis of Randomized Controlled Trials

Background: The effect of zoledronic acid in breast cancer adjuvant therapy concerning improvement of patient survival has yet to be confirmed. We performed a meta-analysis of published and unpublished randomized controlled trials with the aim of accurate evaluation between clinical outcome and the association of the addition of zoledronic acid to adjuvant therapy.

Methods: We searched Pubmed (from 1966 to present) and online abstracts from the proceeding Annual Meetings of the American Society of Clinical Oncology (ASCO) (years 1992–2010) and online abstracts from San Antonio Breast Cancer Symposium (years 2004–2010). A total of five eligible studies including 3676 subjects and 3678 controls met our search criteria and were evaluated. Random and fixed-effects meta-analytical models were used where indicated, and between-study heterogeneity was assessed. The primary study endpoints were the DFS. Secondary endpoints were OS, distant or loco-regional recurrence free survival and bone metastasis free survival.

Results: Compared with the control arm, adjuvant breast cancer treatment with zoledronic acid did not significantly improve overall survival (OS), disease free survival (DFS), bone metastasis free survival, distant and locoregional recurrence free survival. However, in the postmenopausal subgroup, the addition of zoledronic acid to standard therapy could significantly improve DFS (RR=0.763, 95%CI 0.658−0.884, p&lt;0.001) and reduce the risk of distant (RR=0.744, 95% CI 0.611−0.906, p=0.003) and locoregional recurrence (RR=0.508, 95% CI 0.340−0.760, p=0.001).

Discussion: Adjuvant zoledronic acid may potentially improve the prognosis of postmenopausal patients. Additional studies are needed to evaluate the value of adjuvant treatment of zoledronic acid in premenopausal couterparts, differing disease stages, and various pathological types of breast cancer.

Citation Information: Cancer Res 2011;71(24 Suppl):Abstract nr P3-16-10.

Brain-derived neurotrophic factor-activated astrocytes produce mechanical allodynia in neuropathic pain

Neuropathic pain management is challenging for physicians and a vexing problem for basic researchers. Recent studies reveal that activated spinal astrocytes may play a vital role in nerve injury-induced neuropathic pain, although the mechanisms are not fully understood. We have found increased glial fibrillary acidic protein (GFAP) expression, a hallmark of reactive gliosis, and elevated brain-derived neurotrophic factor (BDNF) expression in the dorsal horn in a rat model of allodynia induced by spinal nerve ligation (SNL). The high GFAP expression and mechanical allodynia that SNL induces were prevented by the intrathecal injection of the BDNF-sequestering fusion protein TrkB/Fc. Additionally, mechanical allodynia and GFAP overexpression was induced by the spinal administration of exogenous BDNF to naive rats, and exogenous BDNF given together with fluorocitrate, an astrocytic metabolism inhibitor, inhibited allodynia and GFAP upregulation. Exogenous BDNF also activated the astrocytes directly when tested in vitro. Furthermore, intrathecal administration of BDNF-stimulated astrocytes also induced mechanical allodynia in naive rats. All of these results indicate that astrocytes activated by BDNF might contribute to mechanical allodynia development in neuropathic pain in rats.

Photonic generation of triangular waveform signals by using a dual-parallel Mach-Zehnder modulator

A photonic approach to generate triangular waveform signals is proposed and analyzed. With active bias control, two sub-MZMs (MZ-a and MZ-b) of a dual-parallel Mach-Zehnder modulator (DP-MZM) operate at minimum transmission point, leaving the main MZM (MZ-c) at quadrature transmission point. Triangular waveform can be observed by a parameter setting of modulation index. The proposal is first analyzed and then validated by simulation. The key significance of the scheme is that it is capable of generating triangular waveform signals via a sinusoid local oscillator.

Two novel DAX1 gene mutations in Chinese patients with X-linked adrenal hypoplasia congenita: clinical, hormonal and genetic analysis

Mutations in the DAX1 gene result in X-linked congenital adrenal hypoplasia (AHC). Affected boys usually present with primary adrenal failure in early infancy or childhood and hypogonadotropic hypogonadism (HH) at puberty. This paper describes the clinical, hormonal, radiological, and genetic characteristics of 2 Chinese patients with X-linked AHC. Primary adrenal insufficiency occurred in the 2 patients during their childhood and HH was recognized at puberty. Genomic DNA was extracted from their peripheral blood leukocytes and coding sequence abnormalities of the DAX1 gene were assessed by PCR and direct sequencing analysis. Genetic analysis of the DAX1 gene revealed 2 novel mutations c.572-575 dupGGGC, p.Thr193Gly,fs,205X and c.773- 774 dupCC, p.Ser259Pro,fs,264X in exon 1, causing frameshifts and yeilding premature stop codons at 205 and 264, respectively. This study identifies 2 novel mutations in the DAX1 gene which can further expand the mutation database and benefit patients in the diagnosis and treatment of AHC.

A Clinical Study on the Resection of Breast Fibroadenoma Using Two Types of Incision

Background and Aims:

Breast fibroadenoma (FA) is traditionally managed by FA excision through an overlying incision (FETOI). FA excision through a periareolar incision (FETPI) has been developed, paying special attention to incision location to preserve cosmesis. The purpose of this article is to discuss the FETPI technique.

Methods:

The clinical data of 76 patients who underwent FETPI (98 FAs, group A) and 82 patients who underwent FETOI (122 FAs, group B) were retrospectively analyzed in this non-randomized study. Early postoperative complications, nipple sensation loss, and cosmetic results were compared between the two groups. The techniques, indications, and special considerations of the FETPI technique were described and identified.

Results:

The FETPI technique was associated with more early postoperative complications (7/76 vs. 2/82, p = 0.067) and more nipple sensation losses (15/76 vs. 7/82, p = 0.042) than those of the FETOI technique. Cosmetic assessment at 6 months demonstrated statistically more excellent/good results in group A than in group B (62/76 vs. 50/82, p = 0.004).

Conclusion:

The FETPI technique yields superior cosmetic results with minor postoperative complications.