RGS14 is a mitotic spindle protein essential from the first division of the mammalian zygote

Heterotrimeric G protein alpha subunits, RGS proteins, and GoLoco motif proteins have been recently implicated in the control of mitotic spindle dynamics in C. elegans and D. melanogaster. Here we show that "regulator of G protein signaling-14" (RGS14) is expressed by the mouse embryonic genome immediately prior to the first mitosis, where it colocalizes with the anastral mitotic apparatus of the mouse zygote. Loss of Rgs14 expression in the mouse zygote results in cytofragmentation and failure to progress to the 2-cell stage. RGS14 is found in all tissues and segregates to the nucleus in interphase and to the mitotic spindle and centrioles during mitosis. Alteration of RGS14 levels in exponentially proliferating cells leads to cell growth arrest. Our results indicate that RGS14 is one of the earliest essential product of the mammalian embryonic genome yet described and has a general role in mitosis.     

Paternal USP26 mutations raise Klinefelter syndrome risk in the offspring of mice and humans

Current understanding holds that Klinefelter syndrome (KS) is not inherited, but arises randomly during meiosis. Whether there is any genetic basis for the origin of KS is unknown. Here, guided by our identification of some USP26 variations apparently associated with KS, we found that knockout of Usp26 in male mice resulted in the production of 41, XXY offspring. USP26 protein is localized at the XY body, and the disruption of Usp26 causes incomplete sex chromosome pairing by destabilizing TEX11. The unpaired sex chromosomes then result in XY aneuploid spermatozoa. Consistent with our mouse results, a clinical study shows that some USP26 variations increase the proportion of XY aneuploid spermatozoa in fertile men, and we identified two families with KS offspring wherein the father of the KS patient harbored a USP26‐mutated haplotype, further supporting that paternal USP26 mutation can cause KS offspring production. Thus, some KS should originate from XY spermatozoa, and paternal USP26 mutations increase the risk of producing KS offspring.     

Multiple Surface Plasmon Resonances in Compound Structure with Metallic Nanoparticle and Nanohole Arrays

The optical properties of a compound structure with metallic nanoparticle and nanohole arrays are numerically investigated by the means of finite-difference time domain method. We report on the observation of multi-valleys in the reflection spectra due to the excitation of surface plasmon (SP) resonant modes of the compound structure. Simulation results show that multiple SP resonances consist of surface plasmon polaritons on the gold film, localized surface plasmons on the nanoparticles, and coupling mode between them. These findings are important for applications utilizing multiple surface plasmon resonances.     

Ru-486、安宫黄体酮、环孢菌素、维拉帕米对非P-g介导的卵巢癌耐顺铂细胞株COC 1/DDP耐药性的逆转

目的 在同一实验系统中比较Ru-486、MPA、VP、CsA对非P-g介导的卵巢癌耐顺铂细胞株COC1/DDP耐药性的逆转作用并对其作用机制进行探讨,为临床克服耐药提供参考依据.方法 采用MTT法从细胞代谢,DNA凝胶电泳从细胞凋亡方面系统观察比较DDP、Ru-486、MPA、VP、CsA 5种药物对卵巢癌多药耐药细胞系COC1/DDP的影响及相互关系,检测上述5种药物与COC1/DDP作用时细胞内GSH-ST和GSH-Px活性的变化,并采用westernblotting以Bcl-2抗体为分子探针对上述5种药物与COC1/DDP作用时细胞内Bcl-2基因的表达进行测定对其逆转机制进行探讨.结果 1)Ku-486、CsA、MPA对COC1/DDP有直接抑制作用,其抑制率随浓度增高进行性升高,、而VP对COC1/DD,P没有直接抑制作用.和DDP联用时,Ru-486、MPA、VP、CsA都能显著增强COC1/DDP对DDP的敏感性,达到一定浓度后,可以完全逆转COC1/DDP对DDP的耐药性.这种逆转是通过抑制细胞代谢、诱导细胞凋亡的结果.2)单纯2.5μg/ml的DDP能使GSH-Px及GST活力上升,除VP外,Ru-486等药物可降低GSH-Px和GST活力,与DDP联用时亦如此.提示,Ru-486、CsA、MPA可以通过抑制GSH转移酶系统阻止对细胞损伤的修复而达到对耐药性的逆转.3)单独的DDP、Ru-486等药物非但对Bcl-2的表达没有抑制作用,反而促进了其表达,以MPA最甚.与DDP联用时,却出现了一个有趣的现象,即可以抑制Bcl-2的表达,Ru-486与DDP联用时Bcl-2的表达几乎完全被阻截.结论 :VP、Ru-486、CsA和MPA对卵巢癌多药耐药细胞系COC1/DDP的耐药性有确切逆转作用.其逆转机制可能与降低GSH转移酶系统活性有关.当与DDP联用时可以通过降低Bcl-2蛋白表达来逆转耐药.     

Impairment of 8-iso-PGF2ALPHA isoprostane metabolism by dietary conjugated linoleic acid (CLA)

8-iso-PGF_2α isoprostane (IP) is one of the most-used markers of lipid peroxidation in experimental models and humans. After its formation, it is promptly metabolized to 2,3 dinor (DIN) in peroxisomes.Conjugated linoleic acid (CLA) is preferentially β-oxidized in peroxisomes which may compete with IP, and thereby may affect its metabolism.In order to verify whether CLA is able to influence IP formation and/or metabolism and to explain the mechanism, we challenged rats supplemented with CLA or with triolein (as a control fatty acid), with a single dose of carbon tetrachloride (CCl₄) or of bacterial lipopolysaccharide (LPS). The results showed that IP and its precursor arachidonic acid hydroperoxide, as well as malondialdheyde (MDA), increase significantly in the liver of rats challenged with CCl₄, irrespective of the diet, while in LPS-treated rats only nitrites in liver and isoprostane in plasma increase. On the other hand, the peroxisomal β-oxidation products of IP, the DIN, is significantly lower in the CLA group with respect to control and triolein groups.To further investigate whether this is due to competition between CLA and IP at the cellular level, we incubated human fibroblasts from healthy subjects or patients with adrenoleukodystrophy (ALD), with CLA and/or commercially available IP. The rationale of this approach is based on the deficient peroxisomal β-oxidation of fibroblasts from ALD patients, leading to a reduced formation of DIN. In both normal and ALD cells, the presence of CLA significantly inhibits the formation of DIN from IP.We may conclude that both in vitro and in vivo studies strongly suggest that CLA may impair IP catabolism in peroxisomes. Consequently an increase of IP, as a sole result of CLA intake, cannot be considered as a marker of lipid peroxidation.     

Age-related changes in the innervation of the prostate gland

The adult prostate gland grows and develops under hormonal control while its physiological functions are controlled by the autonomic nervous system. The prostate gland receives sympathetic input via the hypogastric nerve and parasympathetic input via the pelvic nerve. In addition, the hypogastric and pelvic nerves also provide sensory inputs to the gland. This review provides a summary of the innervation of the adult prostate gland and describes the changes which occur with age and disease. Growth and development of the prostate gland is age dependent as is the occurrence of both benign prostate disease and prostate cancer. In parallel, the activity and influence of both the sympathetic and parasympathetic nervous system changes with age. The influence of the sympathetic nervous system on benign prostatic hyperplasia is well documented and this review considers the possibility of a link between changes in autonomic innervation and prostate cancer progression.     

Faced with inequality: chicken do not have a general dosage compensation of sex-linked genes

Background  

The contrasting dose of sex chromosomes in males and females potentially introduces a large-scale imbalance in levels of gene expression between sexes, and between sex chromosomes and autosomes. In many organisms, dosage compensation has thus evolved to equalize sex-linked gene expression in males and females. In mammals this is achieved by X chromosome inactivation and in flies and worms by up- or down-regulation of X-linked expression, respectively. While otherwise widespread in systems with heteromorphic sex chromosomes, the case of dosage compensation in birds (males ZZ, females ZW) remains an unsolved enigma.