CPEB3 deficiency in mice affect ovarian follicle development and causes premature ovarian insufficiency

Premature ovarian insufficiency (POI) is a heterogeneous and multifactorial disorder. In recent years, there has been an increasing interest in research on the pathogenesis and treatment of POI, owing to the implementation of the second-child policy in China. Cytoplasmic polyadenylation element-binding protein 3 (CPEB3) is an RNA-binding protein that can bind to specific RNA sequences. CPEB3 can bind to and affect the expression, cellular location, and stability of target RNAs. Cpeb3 is highly expressed in the ovary; however, its functions remain unknown. In this study, Cpeb3-mutant mice were used to characterize the physiological functions of CPEB3. Cpeb3-mutant female mice manifested signs of gradual loss of ovarian follicles, ovarian follicle development arrest, increased follicle atresia, and subfertility with a phenotype analogous to POI in women. Further analysis showed that granulosa cell proliferation was inhibited and apoptosis was markedly increased in Cpeb3-mutant ovaries. In addition, the expression of Gdf9, a potential target of CPEB3, was decreased in Cpeb3-mutant ovaries and oocytes. Altogether, these results reveal that CPEB3 is essential for ovarian follicle development and female fertility as it regulates the expression of Gdf9 in oocytes, disruption of which leads to impaired ovarian follicle development and POI.Subject terms: RNA-binding proteins, Infertility     

北京市主城区不透水面时空演变及其热环境效应研究

城市不透水面是表征城市化进程的重要指标,开展城市不透水面研究对生态环境监测及城市建设规划具有重要意义.以北京市主城区为研究区,基于Landsat影像采用支持向量机(SVM)和线性光谱混合分解模型(LSMM)相结合的方法提取研究区2002年、2009年和2017年三期不透水面;同时采用辐射传输方程法反演研究区地表温度,分...     

Elevated GAPDH expression is associated with the proliferation and invasion of lung and esophageal squamous cell carcinomas

Glyceraldehyde‐3‐phosphate dehydrogenase, is one of the most investigated housekeeping genes and widely used as an internal control in analysis of gene expression levels. The present study was designed to assess whether GAPDH is associated with cancer cell growth and progression and, therefore may not be a good internal control in cancer research. Our results from clinical tissue studies showed that the levels of GAPDH protein were significantly up‐regulated in lung squamous cell carcinoma tissues, compared with the adjacent normal lung tissues, and this was confirmed by western blotting and immunohistochemistry. GAPDH knockdown by siRNA resulted in significant reductions in proliferation, migration, and invasion of lung squamous carcinoma cells in vitro. In a nude mouse cancer xenograft model, GAPDH knockdown significantly inhibited the cell proliferation and migration/invasion in vivo. In summary, GAPDH may not be an appropriate internal control for gene expression studies, especially in cancer research. The role of GAPDH in cancer development and progression should be further examined in pre‐clinical and clinical studies.     

Studying the Effects of Reproductive Hormones and Bacterial Vaginosis on the Glycome of Lavage Samples from the Cervicovaginal Cavity

The cervicovaginal fluid (CVF) coating the vaginal epithelium is an important immunological mediator, providing a barrier to infection. Glycosylation of CVF proteins, such as mucins, IgG and S-IgA, plays a critical role in their immunological functions. Although multiple factors, such as hormones and microflora, may influence glycosylation of the CVF, few studies have examined their impact on this important immunological fluid. Herein we analyzed the glycosylation of cervicovaginal lavage (CVL) samples collected from 165 women under different hormonal conditions including: (1) no contraceptive, post-menopausal, (2) no contraceptive, days 1-14 of the menstrual cycle, (3) no contraceptive, days 15-28 of the menstrual cycle, (4) combined-oral contraceptive pills for at least 6 months, (5) depo-medroxyprogesterone acetate (Depo-Provera) injections for at least 6 months, (6) levonorgestrel IUD for at least 1 month. Glycomic profiling was obtained using our lectin microarray system, a rapid method to analyze carbohydrate composition. Although some small effects were observed due to hormone levels, the major influence on the glycome was the presence of an altered bacterial cohort due to bacterial vaginosis (BV). Compared to normal women, samples from women with BV contained lower levels of sialic acid and high-mannose glycans in their CVL. The change in high mannose levels was unexpected and may be related to the increased risk of HIV-infection observed in women with BV, as high mannose receptors are a viral entry pathway. Changes in the glycome were also observed with hormonal contraceptive use, in a contraceptive-dependent manner. Overall, microflora had a greater impact on the glycome than hormonal levels, and both of these effects should be more closely examined in future studies given the importance of glycans in the innate immune system.     

Nutritional Energy Stimulates NAD+ Production to Promote Tankyrase-Mediated PARsylation in Insulinoma Cells

The poly-ADP-ribosylation (PARsylation) activity of tankyrase (TNKS) regulates diverse physiological processes including energy metabolism and wnt/β-catenin signaling. This TNKS activity uses NAD⁺ as a co-substrate to post-translationally modify various acceptor proteins including TNKS itself. PARsylation by TNKS often tags the acceptors for ubiquitination and proteasomal degradation. Whether this TNKS activity is regulated by physiological changes in NAD⁺ levels or, more broadly, in cellular energy charge has not been investigated. Because the NAD⁺ biosynthetic enzyme nicotinamide phosphoribosyltransferase (NAMPT) in vitro is robustly potentiated by ATP, we hypothesized that nutritional energy might stimulate cellular NAMPT to produce NAD⁺ and thereby augment TNKS catalysis. Using insulin-secreting cells as a model, we showed that glucose indeed stimulates the autoPARsylation of TNKS and consequently its turnover by the ubiquitin-proteasomal system. This glucose effect on TNKS is mediated primarily by NAD⁺ since it is mirrored by the NAD⁺ precursor nicotinamide mononucleotide (NMN), and is blunted by the NAMPT inhibitor FK866. The TNKS-destabilizing effect of glucose is shared by other metabolic fuels including pyruvate and amino acids. NAD⁺ flux analysis showed that glucose and nutrients, by increasing ATP, stimulate NAMPT-mediated NAD⁺ production to expand NAD⁺ stores. Collectively our data uncover a metabolic pathway whereby nutritional energy augments NAD⁺ production to drive the PARsylating activity of TNKS, leading to autoPARsylation-dependent degradation of the TNKS protein. The modulation of TNKS catalytic activity and protein abundance by cellular energy charge could potentially impose a nutritional control on the many processes that TNKS regulates through PARsylation. More broadly, the stimulation of NAD⁺ production by ATP suggests that nutritional energy may enhance the functions of other NAD⁺-driven enzymes including sirtuins.     

急性髓系白血病相关基因的DNA甲基化

急性髓系白血病(acute myeloid leukemia,AML)是异质性造血干细胞恶性克隆性疾病,主要表现为外周血、骨髓以及其他组织中的原始细胞克隆性扩增。近年来,AML发病率呈逐年增加的趋势,对人类健康产生巨大的威胁。在不同种族及不同性别中,AML发病率及死亡率存在显著差异。AML是一种复杂疾病,与遗传突变及异常表观遗传修饰密切相关。DNA甲基化是重要的表观遗传修饰,AML相关基因的异常DNA甲基化修饰对疾病的发生发展极其重要。该文对AML相关基因的异常甲基化修饰进行了系统的作用机制分析,并对重要基因进行了功能分类。该文总结的具有异常DNA甲基化修饰的基因,有望辅助预测AML的治疗及预后效果,并为设计个体化AML治疗方案提供全新的思路。     

Lonafarnib Is a Potential Inhibitor for Neovascularization

Atherosclerosis is a common cardiovascular disease that involves the build-up of plaque on the inner walls of the arteries. Intraplaque neovacularization has been shown to be essential in the pathogenesis of atherosclerosis. Previous studies showed that small-molecule compounds targeting farnesyl transferase have the ability to prevent atherosclerosis in apolipoprotein E-deficient mice, but the underlying mechanism remains to be elucidated. In this study, we found that lonafarnib, a specific inhibitor of farnesyl transferase, elicits inhibitory effect on vascular endothelial capillary assembly in vitro in a dose-dependent manner. In addition, we showed that lonafarnib treatment led to a dose-dependent decrease in scratch wound closure in vitro, whereas it had little effect on endothelial cell proliferation. These data indicate that lonafarnib inhibits neovascularization via directly targeting endothelial cells and disturbing their motility. Moreover, we demonstrated that pharmacological inhibition of farnesyl transferase by lonafarnib significantly impaired centrosome reorientation toward the leading edge of endothelial cells. Mechanistically, we found that the catalytic β subunit of farnesyl transferase associated with a cytoskeletal protein important for the establishment and maintenance of cell polarity. Additionally, we showed that lonafarnib remarkably inhibited the expression of the cytoskeletal protein and interrupted its interaction with farnesyl transferase. Our findings thus offer novel mechanistic insight into the protective effect of farnesyl transferase inhibitors on atherosclerosis and provide encouraging evidence for the potential use of this group of agents in inhibiting plaque neovascularization.     

Combined Salvianolic Acid B and Ginsenoside Rg1 Exerts Cardioprotection against Ischemia/Reperfusion Injury in Rats

Lack of pharmacological strategies in clinics restricts the patient prognosis with myocardial ischemia/reperfusion (I/R) injury. The aim of this study was to evaluate the cardioprotection of combined salvianolic acid B (SalB) and ginsenoside Rg1 (Rg1) against myocardial I/R injury and further investigate the underlying mechanism. I/R injury was induced by coronary artery ligation for Wistar male rats and hypoxia/reoxygenation injury was induced on H9c2 cells. Firstly, the best ratio between SalB and Rg1was set as 2:5 based on their effects on heart function detected by hemodynamic measurement. Then SalB-Rg1 (2:5) was found to maintain mitochondrial membrane potential and resist apoptosis and necrosis in H9c2 cell with hypoxia/reoxygenation injury. Companying with same dose of SalB or Rg1 only, SalB-Rg1 showed more significant effects on down-regulation of myocardial infarct size, maintenance of myocardium structure, improvement on cardiac function, decrease of cytokine secretion including TNF-α, IL-1β, RANTES and sVCAM-1. Finally, the SalB-Rg1 improved the viability of cardiac myocytes other than cardiac fibroblasts in rats with I/R injury using flow cytometry. Our results revealed that SalB-Rg1 was a promising strategy to prevent myocardial I/R injury.     

Generation and analysis of ESTs from the grass carp, Ctenopharyngodon idellus

Grass carp, Ctenopharyngodon idellus (Valenciennes, 1844), is an economically important species widely cultured in the world, but its genome research resources are largely lacking. The objectives of this study were to construct normalized cDNA libraries for efficient EST analysis, to generate ESTs from these libraries, and to identify EST-related molecular markers such as microsatellites and single nucleotide polymorphisms (SNPs) for genetic analysis of this species. A total of 6,269 ESTs were generated representing 4,815 unique sequences, from which 105 putative microsatellites and 5,228 SNPs were identified. These genome resources provide the material basis for future genetic and functional analyses in this species.