抑制CD36与Nogo-B表达抑制三阴性乳腺癌细胞增殖与迁移

分化聚类36（cluster of differentiation 36,CD36）是一种位于细胞表面的膜蛋白受体,可以结合并转运脂肪酸。内质网膜蛋白4B （Nogo-B）在肝脏中调控脂肪酸代谢而影响肝癌的发展。目前并不清楚CD36和Nogo-B的相互作用是否能够影响乳腺癌细胞的增殖和迁移。本研究在三阴性乳腺癌（triple-negative breast cancer,TNBC）细胞中同时干预CD36与Nogo-B的表达来探索它们对细胞增殖与迁移的影响。结果表明在三阴性乳腺癌细胞中,单独抑制CD36或Nogo-B的表达都能够抑制细胞的增殖与迁移;同时抑制CD36与Nogo-B的表达时,这种抑制效果更加明显,且Vimentin、B细胞淋巴瘤-2（B-cell lympoma-2,BCL2）和增殖细胞核抗原（proliferating cell nuclear antigen,PCNA）的表达受到抑制。在小鼠移植瘤模型中,E0771细胞转染CD36或Nogo-B的siRNA后成瘤能力降低;同时敲减CD36和Nogo-B时,肿瘤生长速度显著减慢。机制研究发现,抑制CD36和Nogo-B表达能够抑制脂肪酸结合蛋白4（fatty acid binding protein 4,FABP4）和脂肪酸转运蛋白4（fatty acid transport protein 4,FATP4） mRNA的含量,同时CD36和Nogo-B过表达刺激的细胞增殖被FABP4的siRNA降低,预示着抑制乳腺癌细胞中CD36与Nogo-B的表达可能通过抑制脂肪酸的吸收和转运而抑制细胞的生长和迁移。此外,抑制CD36与Nogo-B的表达可激活P53-P21-Rb信号通路,参与抑制CD36与Nogo-B表达而抑制的细胞增殖与迁移。本研究证明同时抑制CD36和Nogo-B的表达能够协同抑制三阴性乳腺癌细胞的增殖和迁移,为临床抗三阴性乳腺癌药物的开发提供了新的靶点。     

表达条件对金属激活酶NAOase离子依赖的活性分析

N-乙酰鸟氨酸脱酰基酶为一种新型手性拆分酶制剂,酶活性依赖于Mg2＋、Mn2＋、Zn2＋及Co2＋ 中的某种金属离子。以高表达NAOase的重组菌DH10B/argE-pHsh为研究对象,考察不同培养条件下Mg2＋、Mn2＋、Zn2＋及Co2＋ 4种离子对重组菌的生长、酶的表达活性及表达量的影响。结果发现：同种离子在不同条件下对重组菌的生长影响不大,但对酶活性影响显著。4种离子在合适浓度时皆能提高酶活性,促进强度从高到低依次为Mn2＋、Mg2＋、Co2＋和Zn2＋。在TB培养基中,Mn2＋为15 mmol/L时：NAOase比酶活达到1 272.7 U/mL,是未添加时的4.67倍,激活作用显著高于其他离子。SDS-PAGE电泳实验表明4种离子的蛋白表达量基本相同。     

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     

Methylene blue blocks cGMP production and disrupts directed migration of microglia to nerve lesions in the leech CNS

Migration and accumulation of microglial cells at sites of injury are important for nerve repair. Recent studies on the leech central nervous system (CNS), in which synapse regeneration is successful, have shown that nitric oxide (NO) generated immediately after injury by endothelial nitric oxide synthase (eNOS) stops migrating microglia at the lesion. The present study obtained results indicating that NO may act earlier, on microglia migration, and aimed to determine mechanisms underlying NO's effects. Injury induced cGMP immunoreactivity at the lesion in a pattern similar to that of eNOS activity, immunoreactivity, and microglial cell accumulation, which were all focused there. The soluble guanylate cyclase (sGC) inhibitor methylene blue (MB) at 60 microM abolished cGMP immunoreactivity at lesions and blocked microglial cell migration and accumulation without interfering with axon conduction. Time-lapse video microscopy of microglia in living nerve cords showed MB did not reduce cell movement but reduced directed movement, with significantly more cells moving away from the lesion or reversing direction and fewer cells moving toward the lesion. The results indicate a new role for NO, directing the microglial cell migration as well as stopping it, and show that NO's action may be mediated by cGMP.     

Combining Serum Cystatin C with Total Bilirubin Improves Short-Term Mortality Prediction in Patients with HBV-Related Acute-On-Chronic Liver Failure

Background & Aims

HBV-related acute-on-chronic liver failure (HBV-ACLF) is a severe liver disease which results in a high mortality in China. To early predict the prognosis of the patients may prevent the complications and improve the survival. This study was aimed to develop a new prognostic index to estimate the survival related to HBV-ACLF.

Methods

Consecutive patients with HBV-ACLF were included in a prospective observational study. Serum Cystatin C concentrations were measured by using the particle-enhanced immunonephelometry assay. All of the patients were followed for at least 3 months. Cox regression analysis was carried out to identify which factors were predictive of mortality. The area under the receiver operating characteristic curve (AUC) was used to evaluate the efficacy of the variates for early predicting mortality.

Results

Seventy-two patients with HBV-ACLF were recruited between January 2012 and January 2013. Thirty patients died (41.7%) during 3-months followed up. Cox multivariate regression analysis identified serum cystatin C (CysC) and total bilirubin (TBil) were independent factors significantly (P < 0.01) associated with survival. Our results further showed that new prognostic index (PI) combining serum CysC with TBil was a good indicator for predicting the mortality of patients with HBV-ACLF. Specifically, the PI had a higher accuracy than the CTP, MELD, or MELD-Na scoring for early prediction short-term survival of HBV-ACLF patients with normal levels of serum creatinine (Cr). The survival rate in low risk group (PI < 3.91) was 94.3%, which was markedly higher than those in the high-risk group (PI ≥ 3.91) (17.4%, P < 0.001).

Conclusion

We developed a new prognostic index combining serum CysC with TBil which early predicted the short-term mortality of HBV-ACLF patients.     

A Neural Network Model for K(λ) Retrieval and Application to Global K par Monitoring

Accurate estimation of diffuse attenuation coefficients in the visible wavelengths K _d(λ) from remotely sensed data is particularly challenging in global oceanic and coastal waters. The objectives of the present study are to evaluate the applicability of a semi-analytical K _d(λ) retrieval model (SAKM) and Jamet’s neural network model (JNNM), and then develop a new neural network K _d(λ) retrieval model (NNKM). Based on the comparison of K _d(λ) predicted by these models with in situ measurements taken from the global oceanic and coastal waters, all of the NNKM, SAKM, and JNNM models work well in K _d(λ) retrievals, but the NNKM model works more stable and accurate than both SAKM and JNNM models. The near-infrared band-based and shortwave infrared band-based combined model is used to remove the atmospheric effects on MODIS data. The K _d(λ) data was determined from the atmospheric corrected MODIS data using the NNKM, JNNM, and SAKM models. The results show that the NNKM model produces <30% uncertainty in deriving K _d(λ) from global oceanic and coastal waters, which is 4.88-17.18% more accurate than SAKM and JNNM models. Furthermore, we employ an empirical approach to calculate K _par from the NNKM model-derived diffuse attenuation coefficient at visible bands (443, 488, 555, and 667 nm). The results show that our model presents a satisfactory performance in deriving K _par from the global oceanic and coastal waters with 20.2% uncertainty. The K _par are quantified from MODIS data atmospheric correction using our model. Comparing with field measurements, our model produces ~31.0% uncertainty in deriving K _par from Bohai Sea. Finally, the applicability of our model for general oceanographic studies is briefly illuminated by applying it to climatological monthly mean remote sensing reflectance for time ranging from July, 2002- July 2014 at the global scale. The results indicate that the high K _d(λ) and K _par values are usually found around the coastal zones in the high latitude regions, while low K _d(λ) and K _par values are usually found in the open oceans around the low-latitude regions. These results could improve our knowledge about the light field under waters at either the global or basin scales, and be potentially used into general circulation models to estimate the heat flux between atmosphere and ocean.