Sensorimotor and Neurocognitive Dysfunctions Parallel Early Telencephalic Neuropathology in Fucosidosis Mice.

Fucosidosis is a lysosomal storage disorder (LSD) caused by lysosomal α-L-fucosidase deficiency. Insufficient α-L-fucosidase activity triggers accumulation of undegraded, fucosylated glycoproteins and glycolipids in various tissues. The human phenotype is heterogeneous, but progressive motor and cognitive impairments represent the most characteristic symptoms. Recently, Fuca1-deficient mice were generated by gene targeting techniques, constituting a novel animal model for human fucosidosis. These mice display widespread LSD pathology, accumulation of secondary storage material and neuroinflammation throughout the brain, as well as progressive loss of Purkinje cells. Fuca1-deficient mice and control littermates were subjected to a battery of tests detailing different aspects of motor, emotional and cognitive function. At an early stage of disease, we observed reduced exploratory activity, sensorimotor disintegration as well as impaired spatial learning and fear memory. These early markers of neurological deterioration were related to the respective stage of neuropathology using molecular genetic and immunochemical procedures. Increased expression of the lysosomal marker Lamp1 and neuroinflammation markers was observed throughout the brain, but appeared more prominent in cerebral areas in comparison to cerebellum of Fuca1-deficient mice. This is consistent with impaired behaviors putatively related to early disruptions of motor and cognitive circuits particularly involving cerebral cortex, basal ganglia, and hippocampus. Thus, Fuca1-deficient mice represent a practical and promising fucosidosis model, which can be utilized for pathogenetic and therapeutic studies.

A mouse model for fucosidosis recapitulates storage pathology and neurological features of the milder form of the human disease.

Fucosidosis is a rare lysosomal storage disorder caused by the inherited deficiency of the lysosomal hydrolase α-L-fucosidase, which leads to an impaired degradation of fucosylated glycoconjugates. Here, we report the generation of a fucosidosis mouse model, in which the gene for lysosomal α-L-fucosidase (Fuca1) was disrupted by gene targeting. Homozygous knockout mice completely lack α-L-fucosidase activity in all tested organs leading to highly elevated amounts of the core-fucosylated glycoasparagine Fuc(α1,6)-GlcNAc(ß1-N)-Asn and, to a lesser extent, other fucosylated glycoasparagines, which all were also partially excreted in urine. Lysosomal storage pathology was observed in many visceral organs, such as in the liver, kidney, spleen and bladder, as well as in the central nervous system (CNS). On the cellular level, storage was characterized by membrane-limited cytoplasmic vacuoles primarily containing water-soluble storage material. In the CNS, cellular alterations included enlargement of the lysosomal compartment in various cell types, accumulation of secondary storage material and neuroinflammation, as well as a progressive loss of Purkinje cells combined with astrogliosis leading to psychomotor and memory deficits. Our results demonstrate that this new fucosidosis mouse model resembles the human disease and thus will help to unravel underlying pathological processes. Moreover, this model could be utilized to establish diagnostic and therapeutic strategies for fucosidosis.

Kaede for detection of protein oligomerization.

Photoconvertible fluorescent proteins such as Kaede are routinely used for tracking proteins, organelles, and whole cells. Kaede was the first identified photoconvertible fluorescent protein and has since become the most commonly used photoconvertible fluorescent protein in vertebrates. Kaede can be irreversibly converted from a green to a red fluorescent form upon UV/blue light irradiation and fluorescence of each form can be isolated separately by appropriate filter sets. Spectral properties of the Kaede forms allow Förster resonance energy transfer (FRET) from the green form as donor to the red form as acceptor. As a sample containing oligomerized Kaede-containing proteins is exposed to UV or blue light, FRET first increases as green Kaede is converted to red and then decreases as the green donor becomes depleted. Thus, FRET information is potentially obtained from a number of independent measurements taken as photoconversion proceeds. We demonstrate here the application of this approach to detect homo-aggregation and conformational dynamics of plant protein constructs. Structural alterations of 2-cys peroxiredoxin­Kaede were successfully detected depending on the redox state in living plant cells. Photoconversion was performed gradually and donor emission, acceptor emission, and FRET-derived sensitized acceptor emission were measured at each step of conversion. Since photoconvertible proteins have not been routinely used in plants, two plasmids have been designed to facilitate plant applications. The plasmids allow either transient expression of Kaede-containing protein constructs in plant cells or Gateway cloning and stable transformation of plants.

A novel titin mutation in adult-onset familial dilated cardiomyopathy.

Familial dilated cardiomyopathy is a major cause of advanced heart failure and heart transplantation. In most families, the disease-causing mutation is unknown, and relatives should therefore undergo periodic screening to facilitate early diagnosis and therapy. In the present study, we describe a novel titin truncation mutation causing adult-onset familial dilated cardiomyopathy in an Israeli Arab family. The family members underwent physical examination, electrocardiography, and Doppler echocardiography. Linkage to candidate loci was performed, followed by gene sequencing. We identified 13 clinically affected family members (8 men and 5 women, mean age 47 ± 12 years). Compared with their healthy first-degree relatives, the affected relatives had a larger end-diastolic left ventricular dimension (60 ± 10 vs 49 ± 4 mm, p <0.001), lower ejection fraction (43 ± 11% vs 60 ± 6%, p <0.001), and markedly higher end-systolic volume indexes but no difference in wall thickness or diastolic function. The linkage studies or direct sequencing excluded LMNA, MYH7, TNNT2, TNNI3, SCN5A, DES, SGCD, ACTC, PLN, and MYH6 but established linkage to the TTN locus at chromosome 2q31, yielding a maximum (2-point) LOD score of 3.44. Sequence analysis identified an insertion (c.58880insA), causing protein truncation after 19,628 amino acids (p.S19628IfsX1). No founder effect was found among the Israeli Arabs. In conclusion, titin is a giant protein with a key role in sarcomere assembly, force transmission, and maintenance of resting tension. Although some mutations result in skeletal myopathy, others cause isolated, maturity-onset cardiomyopathy.

CoSMoS and TwinPaW: initial report on two new German twin studies.

After briefly recapitulating two earlier German twin studies (BiLSAT and GOSAT), we present two new German twin studies with a longitudinal perspective: CoSMoS and TwinPaW. The twin study on Cognitive ability, Self-reported Motivation and School performance (CoSMoS) aims to investigate predictors and influences of school performance in a genetically sensitive design, beginning with children in late elementary school. The Twin study on Personality And Wellbeing (TwinPaW) focuses on adult personality and its relation to physical health as well as health-related behavior in an adult sample of twins. Both studies are characterized by an effort to recruit new large twin samples through a novel recruitment procedure aimed at reducing self-selective sampling. In two German federal states, contact information on persons born on the same day and with the same name was retrieved from record sections. From the resulting pool of more than 36,000 addresses we contacted approximately 2000 parents of twins aged 9 and 10 for CoSMoS, as well as 2000 adult twin pairs for TwinPaW by telephone and mail. Personal contact by telephone proved to be more efficient with agreement rates of 63% in the children sample and 65% in the adult sample. In this article we briefly describe the rationale and the study aims of CoSMoS and TwinPaW as well as the characteristics of the sample we have recruited so far.

German Observational Study of Adult Twins (GOSAT): a multimodal investigation of personality, temperament and cognitive ability.

The German Observational Study of Adult Twins (GOSAT) is the largest population-based observational twin study in Germany to date. Embedded in the Bielefeld Longitudinal Study of Adult Twins (BiLSAT), it addresses the etiology of personality, temperament and cognitive ability in a sample of 300 monozygotic (MZ) and dizygotic (DZ) adult twin pairs between 18 and 70 years of age. A major aim of the GOSAT lies in the utilization of different modes of measurement, (i.e., peer reports and observational data), in addition to self-reports which have been used predominantly in past behavioral genetic research on personality and temperament in adults. Participants completed a full day assessment at the University of Bielefeld including videotaped social interactions and presentations, psychometric intelligence tests and computerized elementary cognitive tasks as well as objective measures and unobtrusive behavior counts. The research design of the GOSAT was devised to reduce the potential impact of systematic rater bias on estimates of genetic and environmental influences to a minimum. In combination with extensive self- and peer report data on key personality and personality related dimensions available from the BiLSAT, the GOSAT provides a rich dataset, which currently includes DNA samples from 80% of its participants.