Anti-Semaphorin 4D Rescues Motor, Cognitive, and Respiratory Phenotypes in a Rett Syndrome Mouse Model

Rett syndrome is a neurodevelopmental disorder caused by mutations of the methyl-CpG binding protein 2 gene. Abnormal physiological functions of glial cells contribute to pathogenesis of Rett syndrome. Semaphorin 4D (SEMA4D) regulates processes central to neuroinflammation and neurodegeneration including cytoskeletal structures required for process extension, communication, and migration of glial cells. Blocking SEMA4D-induced gliosis may preserve normal glial and neuronal function and rescue neurological dysfunction in Rett syndrome. We evaluated the pre-clinical therapeutic efficacy of an anti-SEMA4D monoclonal antibody in the Rett syndrome Mecp2T158A transgenic mouse model and investigated the contribution of glial cells as a proposed mechanism of action in treated mice and in primary glial cultures isolated from Mecp2T158A/y mutant mice. SEMA4D is upregulated in neurons while glial fibrillary acidic protein and ionized calcium binding adaptor molecule 1-positive cells are upregulated in Mecp2T158A/y mice. Anti-SEMA4D treatment ameliorates Rett syndrome-specific symptoms and improves behavioural functions in both pre-symptomatic and symptomatic cohorts of hemizygous Mecp2T158A/y male mice. Anti-SEMA4D also reduces astrocyte and microglia activation in vivo. In vitro experiments demonstrate an abnormal cytoskeletal structure in mutant astrocytes in the presence of SEMA4D, while anti-SEMA4D antibody treatment blocks SEMA4D–Plexin B1 signaling and mitigates these abnormalities. These results suggest that anti-SEMA4D immunotherapy may be an effective treatment option to alleviate symptoms and improve cognitive and motor function in Rett syndrome.

An ocular glymphatic clearance system removes β-amyloid from the rodent eye

Despite high metabolic activity, the retina and optic nerve head lack traditional lymphatic drainage. We here identified an ocular glymphatic clearance route for fluid and wastes via the proximal optic nerve in rodents. β-amyloid (Aβ) was cleared from the retina and vitreous via a pathway dependent on glial water channel aquaporin-4 (AQP4) and driven by the ocular-cranial pressure difference. After traversing the lamina barrier, intra-axonal Aβ was cleared via the perivenous space and subsequently drained to lymphatic vessels. Light-induced pupil constriction enhanced efflux, whereas atropine or raising intracranial pressure blocked efflux. In two distinct murine models of glaucoma, Aβ leaked from the eye via defects in the lamina barrier instead of directional axonal efflux. The results suggest that, in rodents, the removal of fluid and metabolites from the intraocular space occurs through a glymphatic pathway that might be impaired in glaucoma.

Abstract B22: Antitumor effects of selective PRMT1 inhibitors on neuroblastoma in vitro and in vivo

The MYC family of transcription factors is one of the most frequently overexpressed oncogenes in human malignancies, including tumors that are derived from the nervous system. MYCN plays a causative role in neuroblastoma, a common and fatal childhood cancer of the developing sympathetic nervous system. Thus, the MYC family has been considered as a promising cancer target; however, so far, no small molecules can directly target MYC or MYCN in vivo. We have recently reported that PRMT1 functions as a key regulator of the stability and oncogenicity of MYCN. In this study, we have performed the structure-activity relationship analysis of diamidine-related PRMT1-seletive inhibitors. In correlation with their inhibition against PRMT1 in biochemical assays, these compounds showed remarkable anticancer properties both in neuroblastoma cell lines in vitro and in a preclinical mouse model of neuroblastoma in vivo. Mechanistically, these potent PRMT1 inhibitors destabilized MYCN, caused cell cycle arrest, and restored normal developmental signals of the developing sympathetic neuroblast precursors. Together, our results demonstrate that PRMT1-seletive inhibitors are promising anti-neuroblastoma agents and may represent a general strategy to target certain MYC/MYCN-driven cancers.

Citation Format: Jeanne N. Hansen, Louis T. Lotta, Allison Eberhardt, Yujun George Zheng, Sen Ji, Shengyong Yang, Nina F. Schor, Xingguo Li. Antitumor effects of selective PRMT1 inhibitors on neuroblastoma in vitro and in vivo [abstract]. In: Proceedings of the AACR Special Conference: Pediatric Cancer Research: From Basic Science to the Clinic; 2017 Dec 3-6; Atlanta, Georgia. Philadelphia (PA): AACR; Cancer Res 2018;78(19 Suppl):Abstract nr B22.

Beneficial effects of low alcohol exposure, but adverse effects of high alcohol intake on glymphatic function

Prolonged intake of excessive amounts of ethanol is known to have adverse effects on the central nervous system (CNS). Here we investigated the effects of acute and chronic ethanol exposure and withdrawal from chronic ethanol exposure on glymphatic function, which is a brain-wide metabolite clearance system connected to the peripheral lymphatic system. Acute and chronic exposure to 1.5 g/kg (binge level) ethanol dramatically suppressed glymphatic function in awake mice. Chronic exposure to 1.5 g/kg ethanol increased GFAP expression and induced mislocation of the astrocyte-specific water channel aquaporin 4 (AQP4), but decreased the levels of several cytokines. Surprisingly, glymphatic function increased in mice treated with 0.5 g/kg (low dose) ethanol following acute exposure, as well as after one month of chronic exposure. Low doses of chronic ethanol intake were associated with a significant decrease in GFAP expression, with little change in the cytokine profile compared with the saline group. These observations suggest that ethanol has a J-shaped effect on the glymphatic system whereby low doses of ethanol increase glymphatic function. Conversely, chronic 1.5 g/kg ethanol intake induced reactive gliosis and perturbed glymphatic function, which possibly may contribute to the higher risk of dementia observed in heavy drinkers.

Methylation of the phosphatase-transcription activator EYA1 by protein arginine methyltransferase 1: mechanistic, functional, and structural studies

The eyes absent (EYA) family proteins are conserved transcriptional coactivators with intrinsic protein phosphatase activity. They play an essential role in the development of various organs in metazoans. These functions are associated with a unique combination of phosphatase and transactivation activities. However, it remains poorly understood how these activities and the consequent biologic functions of EYA are regulated. Here, we demonstrate that 2 conserved arginine residues, R304 and R306, of EYA1 are essential for its in vitro phosphatase activity and in vivo function during Drosophila eye development. EYA1 physically interacts with protein arginine methyltransferase 1, which methylates EYA1 at these residues both in vitro and in cultured mammalian and insect cells. Moreover, we show that wild-type, but not methylation-defective, EYA1 associates with γ-H2A.X in response to ionizing radiation. Taken together, our results identify the conserved arginine residues of EYA1 that play an important role for its activity, thus implicating arginine methylation as a novel regulatory mechanism of EYA function.-Li, X., Eberhardt, A., Hansen, J. N., Bohmann, D., Li, H., Schor, N. F. Methylation of the phosphatase-transcription activator EYA1 by protein arginine methyltransferase 1: mechanistic, functional, and structural studies.

EYA1 expression and subcellular localization in neuroblastoma and its association with prognostic markers

Neuroblastoma, the most frequently occurring extracranial solid tumor of childhood, arises from neural crest-derived cells that are arrested at an early stage of differentiation in the developing sympathetic nervous system. There is an urgent need to identify clinically relevant biomarkers for better prognosis and treatment of this aggressive malignancy. Eyes Absent 1 (EYA1) is an essential transcriptional coactivator for neuronal developmental programs during organogenesis. Whether or not EYA1 is implicated in neuroblastoma and subcellular localization of EYA1 is relevant to clinical behaviour of neuroblastoma is not known. We studied EYA1 expression and subcellular localization by immunohistochemistry in tissue microarrays containing tumor specimens from 98 patients, 66 of which were characterized by known clinical prognostic markers of neuroblastoma. Immunostaining results were evaluated and statistically correlated with the degree of histologic differentiation and with neuroblastoma risk stratification group characteristics, including stage of disease, patient age, tumor histology and mitosis-karyorrhexis index (MKI), respectively. We found that EYA1 levels were significantly higher in neuroblastomas than in ganglioneuromas and ganglioneuroblastomas. EYA1 was more highly expressed in stage 1,2,3 or 4S tumors as compared to stage 4 tumors (P<0.01). Tumors with high levels of nuclear EYA1 were more frequently associated with high nuclear MYCN levels. These results suggest that modulation of expression and intracellular localization of EYA1 in neural crest cells may provide a novel direction for therapeutic strategies.

Ne in some Stone Meteorites

Ne20, Ne21 and Ne22 has been measured in several stone meteorites. Good agreement with other cosmic ray produced rare gas isotopes was obtained. No indication of primeval neon was found in the chondrites, but one urelite showed excess Ne20.

Apparatus to characterize gas sensor response under real-world conditions in the lab

The use of semiconducting metal-oxide (MOX) based gas sensors in demanding applications such as climate and environmental research as well as industrial applications is currently hindered by their poor reproducibility, selectivity, and sensitivity. This is mainly due to the sensing mechanism which relies on the change of conductivity of the metal-oxide layer. To be of use for advanced applications metal-oxide (MOX) gas sensors need to be carefully prepared and characterized in laboratory environments prior to deployment. This paper describes the working principle, design, and use of a new apparatus that can emulate real-world conditions in the laboratory and characterize the MOX gas sensor signal in tailor-made atmospheres. In particular, this includes the control of trace gas concentrations and the control of oxygen and humidity levels which are important for the surface chemistry of metal-oxide based sensors. Furthermore, the sensor temperature can be precisely controlled, which is a key parameter of semiconducting, sensitive layers, and their response to particular gas compositions. The setup also allows to determine the power consumption of each device individually which may be used for performance benchmarking or monitoring changes of the temperature of the gas composition. Both, the working principle and the capabilities of the gas measurement chamber are presented in this paper employing tin dioxide (SnO2) based micro sensors as exemplary devices.

Human postmortem device retrieval and analysis--orthopaedic, cardiovascular, and dental systems

On the basis of decades of analyzing implant devices, tissues, and clinical records from revision surgical explants (called device failure), studies now include postmortem donors and in situ conditions (called success). A key issue has been information exchange from an interdisciplinary team where basic physical and biological studies complement details of the clinical conditions for each device. Overall, the summary information has shown that most revisions were based on factors associated with the patient health, disease, and compliance, with few outcomes directly correlated with technology and device-specific factors. However, because of the large numbers of devices implanted annually (millions), any sampling that reveals adverse circumstances could result in a high level of importance and the need for additional studies of this type. Experience from prior retrieval and analysis demonstrates significant value where peer reviewed results from investigations have altered the discipline and have improved the quality and longevity of health care associated with implanted devices. This report summarizes completed and ongoing studies of cardiovascular, dental, and orthopaedic systems. Endovascular stents from autopsies showed damage including fretting and corrosion from overlapping and intersecting conditions, plus some corrosion and element transfers to tissues from individual stents. Studies are proposed to increase numbers to evaluate clinical significance. Dental implants from postmortem donors that functioned more than 10 years provided evaluations of cobalt alloy devices and calcium phosphate bone graft substitutes originally investigated in the 1970s. Tissue integration and stability correlated with data from prior laboratory in vitro and in vivo investigations. Studies of articulation and fixation from orthopaedic total joint arthroplasties showed some limitations related to surface changes of YTZ zirconia, specific damage due to implantation procedures, which led to modified instrumentation and techniques, and several examples of conditions leading to longer-term device-to-bone fixation. These types of multidisciplinary studies are continuing.

Improvement of pseudoelasticity and ductility of Beta III titanium alloy--application to orthodontic wires

The pseudoelasticity of metastable Beta III titanium alloy (TMAtrade mark) used for orthodontic applications is obtained by cold wiredrawing. This wire has higher rigidity than cold-drawn NiTi (Nitinoltrade mark, superelastic NiTi SE) and lower recoverable deformation. The low ductility value of Beta III is due to the deformation imposed by wiredrawing. The aim of this research was to improve the behaviour of this alloy by modifying the microstructural parameters to decrease the rigidity and increase the recoverable deformation and ductility of the alloy. The effects of second phase precipitate, grain size, and deformation on the wire mechanical properties were also examined. The isothermal precipitation of alpha (alpha) or omega (omega(isoth)) phases precludes the expression of the pseudoelastic effect. The presence of an omega(isoth) phase considerably increases fracture strength, whereas the alpha phase strongly decreases the ductility and adversely affects the strain recovery (epsilon(r)). To control the grain size, the growth of the recrystallized grains was studied by considering several parameters, which are known to have an influence on grain size, including the cold rolled strain, the temperature, the time of annealing, and the initial grain size. A structure with coarse grains, quenched from a temperature higher than the beta transus (T(beta)), associated with a plastic pre-deformation, contributed to an improved pseudoelastic behaviour, due to the presence of a reversible martensite phase (alpha'') induced by the pre-deformation.

Orthorhombic lattice deformation of CuAlBe shape-memory single crystals under cyclic strain

X-ray diffraction experiments were carried out to prove that X-ray methods can be used to assess strain-induced fatigue in CuAlBe shape-memory alloys. The pseudoelastic fatigue behaviour of CuAlBe single crystals presents a strong decrease of the critical stress of the martensitic transformation. During the fatigue test, the austenitic lattice exhibits a lattice distortion. This lattice distortion evolves during the fatigue test: the austenitic cubic lattice (β1) tends to transform gradually towards an orthorhombic one. Various hypotheses concerning this lattice distortion are proposed.

Modulation of mechanical properties in multiple-component tissue adhesives

In vitro, ex vivo, and in vivo studies were performed to investigate the effect of mixing upon the mechanical properties of a two-component tissue adhesive. The hypothesis investigated was that a more complete mixing of the two components would yield an increase in the mechanical performance of the adhesive. This in turn would be demonstrated by improved outcomes in models of clinical sealant application. In vitro stereological analysis of tissue adhesive mixed and delivered by several different applicators demonstrated variation in the amount of mixing provided by each type of delivery system. Ex vivo tensile adhesive strength showed that there was a correlation between the amount of mixing and bonding strength; that is, more thorough mixing demonstrated higher adhesive strength. No significant difference was seen, however, between the different applicator types and impact on in vivo dermal incisional closure strength. There was a correlation, though, in amount of mixing and in vivo hemostasis. In a rabbit spleen incision model, a more thoroughly mixed sealant corresponded with a decrease in time to obtain complete hemostasis, as well as less sealant used. The effects of mixing on tissue-adhesive mechanical performance were influenced somewhat by the amount of mixing provided by the applicator. This effect, however, was dependent upon the sealant formulation and the type of in vivo application.

Determination of 3D positions of pacemaker leads from biplane angiographic sequences

In vitro and in vivo analyses of stress on pacemaker leads and their components during the heart cycle have become especially important because of incidences of failure of some of these mechanical components. For stress analyses, the three-dimensional (3D) position, shape, and motion of the pacemaker leads must be known accurately at each time point during the cardiac cycle. We have developed a method for determination of the in vivo 3D positions of pacemaker leads during the entire heart cycle. Sequences of biplane images of patients with pacemakers were obtained at 30 frames/s for each projection. The sequences usually included at least two heart cycles. After patient imaging, biplane images of a calibration object were obtained from which the biplane imaging geometry was determined. The centerlines of the leads and unique, identifiable points on the attached electrodes were indicated manually for all acquired images. Temporal interpolation of the lead and electrode data was performed so that the temporal nonsynchronicity of the image acquisition was overcome. Epipolar lines, generated from the calculated geometry, were employed to identify corresponding points along the leads in the pairs of biplane images for each time point. The 3D positions of the lead and electrodes were calculated from the known geometry and from the identified corresponding points in the images. Using multiple image sets obtained with the calibration object at various orientations, the precision of the calculated rotation matrix and of the translation vector defining the imaging geometry was found to be approximately 0.7 degree and 1%, respectively. The 3D positions were reproducible to within 2 mm, with the error lying primarily along the axis between the focal spot and the imaging plane. Using data obtained by temporally downsampling to 15 frames/s, the interpolated data were found to lie within approximately 2 mm of the true position for most of the heart cycle. These results indicate that, with this technique, one can reliably determine pacemaker lead positions throughout the heart cycle, and thereby it will provide the basis for stress analysis on pacemaker leads.

Self-Assembly of n-Alkyl Thiols as Disulfides on Au(111)

A grazing incidence x-ray diffraction study of CH(3)(CH(2))(9)SH self-assembled on the (111) surface of gold revealed a disulfide head group structure, which provides a context in which to understand the structure and self-assembly process of this widely studied system. The structure consists of a nearly hexagonal two-dimensional arrangement of the hydrocarbon chains with a dimerization of the sulfur head groups (accommodated through a gauche bond), resulting in a S-S spacing of 2.2 angstroms. These results demonstrate the importance of internal molecular degrees of freedom in the templating of "soft" organic materials on inorganic substrates.

[Plasma kinetics and elimination of folic acid]

The plasma kinetics and elimination of folic acid were studied in 11 healthy subjects after saturation with a multivitamin preparation. A radioassay was utilized for the determination of folic acid. After the i.m. injection of 1.1 mg folic acid sodium, a maximum plasma level of 63.7 +/- 14.3 nmol/l was reached after 0.69 +/- 0.26 h. The elimination half-life time amounted to 1.53 +/- 0.46 h. Based on the injected amount of folic acid, the cumulative increase in elimination within 24 h amounted to 9.4% +/- 3.1%. Within the first 6 h 81.4% +/- 6.1% of the administered folic acid appeared in the urine and in the following 4 h 17.3% +/- 5.4%.

Effect of transcutaneous electrostimulation on the cell composition of skin exudate

Changes were analysed in the cell composition of skin exudate induced with electrostimulation. The experiments were carried out in a group of healthy young males. In all subjects scarification of forearm skin was carried out three times at intervals of 3 days. During 12 hours after scarification the composition of cells in the exudate was studied by means of the Rebuck test. After the second and third scarification the skin was stimulated with alternating current. It was found that electrostimulation with current of individually selected parameters increased the relative number of neutrophil granulocytes in skin exudate.

Mechanical behaviour of cerclage material consisting of silicon rubber

Silicon rubber specimens of circular or rectangular cross-section (cross-section area between ca. 2 and 7 mm2) are used as cerclage bands. A series of commercial cerclage elements was investigated for mechanical characteristics, such as stress-strain behaviour and modulus of elasticity, using a tensile-testing machine. Large differences in these properties exist among the various specimens. Moreover, time-dependent effects, such as stress-relaxation, retardation, and creep, were analysed by the present investigations. One has to take into consideration that the initial length and stress of the cerclage band vary significantly with time after the operation.

Isotopic Effects in Single Filament Thermal Ion Sources

Isotopic effects occuring during the evaporation of microgram quantities of chemically pure rubidium, potassium and lithium compounds are studied. The measured isotopic ratios show a time dependent variation corresponding to a RAYLEIGH distillation. The fractionation factor is equal to the square root of the ratio of the masses. The highest observed enrichments are 45% for lithium, 10% for potassium and 5% for rubidium. The measured isotopic ratio depends also on the filament material and on the chemical composition of the sample. The discriminations are of the order of the square root of the ratio of the masses.