Age-Related Modifications of Electroencephalogram Coherence in Mice Models of Alzheimer's Disease and Amyotrophic Lateral Sclerosis.

Evident similarities in pathological features in aging and Alzheimer's disease (AD) raise the question of a role for natural age-related adaptive mechanisms in the prevention/elimination of disturbances in interrelations between different brain areas. In our previous electroencephalogram (EEG) studies on 5xFAD- and FUS-transgenic mice, as models of AD and amyotrophic lateral sclerosis (ALS), this suggestion was indirectly confirmed. In the current study, age-related changes in direct EEG synchrony/coherence between the brain structures were evaluated. METHODS: In 5xFAD mice of 6-, 9-, 12-, and 18-month ages and their wild-type (WT5xFAD) littermates, we analyzed baseline EEG coherence between the cortex, hippocampus/putamen, ventral tegmental area, and substantia nigra. Additionally, EEG coherence between the cortex and putamen was analyzed in 2- and 5-month-old FUS mice. RESULTS: In the 5xFAD mice, suppressed levels of inter-structural coherence vs. those in WT5xFAD littermates were observed at ages of 6, 9, and 12 months. In 18-month-old 5xFAD mice, only the hippocampus ventral tegmental area coherence was significantly reduced. In 2-month-old FUS vs. WTFUS mice, the cortex-putamen coherence suppression, dominated in the right hemisphere, was observed. In 5-month-old mice, EEG coherence was maximal in both groups. CONCLUSION: Neurodegenerative pathologies are accompanied by the significant attenuation of intracerebral EEG coherence. Our data are supportive for the involvement of age-related adaptive mechanisms in intracerebral disturbances produced by neurodegeneration.

Kinetics of alpha-synuclein depletion in three brain regions following conditional pan-neuronal inactivation of the encoding gene (Snca) by tamoxifen-induced Cre-recombination in adult mice.

Conditional pan-neuronal inactivation of the Snca gene in 2-month old male and female mice causes dramatic decrease in the level of the encoded protein, alpha-synuclein, in three studied brain regions, namely cerebral cortex, midbrain and striatum, 12 weeks after the last injection of tamoxifen. Kinetics of alpha-synuclein depletion is different in these brain regions with a longer lag period in the cerebral cortex where this protein is normally most abundant. Our results suggest that efficient post-developmental pan-neuronal knockout of alpha-synuclein in adult, i.e. 5- to 6-month old, animals, could be achieved by tamoxifen treatment of 2-month old mice carrying loxP-flanked Snca gene and expressing inducible Cre-ERT2 recombinase under control of the promoter of neuron-specific enolase (NSE) gene.

A bioisostere of Dimebon/Latrepirdine delays the onset and slows the progression of pathology in FUS transgenic mice.

AIMS: To assess effects of DF402, a bioisostere of Dimebon/Latrepirdine, on the disease progression in the transgenic model of amyotrophic lateral sclerosis (ALS) caused by expression of pathogenic truncated form of human FUS protein. METHODS: Mice received DF402 from the age of 42 days and the onset of clinical signs, the disease duration and animal lifespan were monitored for experimental and control animals, and multiple parameters of their gait were assessed throughout the pre-symptomatic stage using CatWalk system followed by a bioinformatic analysis. RNA-seq was used to compare the spinal cord transcriptomes of wild-type, untreated, and DF402-treated FUS transgenic mice. RESULTS: DF402 delays the onset and slows the progression of pathology. We developed a CatWalk analysis protocol that allows detection of gait changes in FUS transgenic mice and the effect of DF402 on their gait already at early pre-symptomatic stage. At this stage, a limited number of genes significantly change expression in transgenic mice and for 60% of these genes, DF402 treatment causes the reversion of the expression pattern. CONCLUSION: DF402 slows down the disease progression in the mouse model of ALS, which is consistent with previously reported neuroprotective properties of Dimebon and its other bioisosteres. These results suggest that these structures can be considered as lead compounds for further optimization to obtain novel medicines that might be used as components of complex ALS therapy.

Molecular and behavioural abnormalities in the FUS-tg mice mimic frontotemporal lobar degeneration: Effects of old and new anti-inflammatory therapies.

Genetic mutations in FUS, a DNA/RNA-binding protein, are associated with inherited forms of frontotemporal lobar degeneration (FTLD) and amyotrophic lateral sclerosis (ALS). A novel transgenic FUS[1-359]-tg mouse line recapitulates core hallmarks of human ALS in the spinal cord, including neuroinflammation and neurodegeneration, ensuing muscle atrophy and paralysis, as well as brain pathomorphological signs of FTLD. However, a question whether FUS[1-359]-tg mouse displays behavioural and brain pro-inflammatory changes characteristic for the FTLD syndrome was not addressed. Here, we studied emotional, social and cognitive behaviours, brain markers of inflammation and plasticity of pre-symptomatic FUS[1-359]-tg male mice, a potential FTLD model. These animals displayed aberrant behaviours and altered brain expression of inflammatory markers and related pathways that are reminiscent to the FTLD-like syndrome. FTLD-related behavioural and molecular Journal of Cellular and Molecular Medicine features were studied in the pre-symptomatic FUS[1-359]-tg mice that received standard or new ALS treatments, which have been reported to counteract the ALS-like syndrome in the mutants. We used anti-ALS drug riluzole (8 mg/kg/d), or anti-inflammatory drug, a selective blocker of cyclooxygenase-2 (celecoxib, 30 mg/kg/d) for 3 weeks, or a single intracerebroventricular (i.c.v.) infusion of human stem cells (Neuro-Cells, 500 000-CD34+ ), which showed anti-inflammatory properties. Signs of elevated anxiety, depressive-like behaviour, cognitive deficits and abnormal social behaviour were less marked in FUS-tg-treated animals. Applied treatments have normalized protein expression of interleukin-1ß (IL-1ß) in the prefrontal cortex and the hippocampus, and of Iba-1 and GSK-3ß in the hippocampus. Thus, the pre-symptomatic FUS[1-359]-tg mice demonstrate FTLD-like abnormalities that are attenuated by standard and new ALS treatments, including Neuro-Cell preparation.

Low Level of Expression of C-Terminally Truncated Human FUS Causes Extensive Changes in the Spinal Cord Transcriptome of Asymptomatic Transgenic Mice.

A number of mutations in a gene encoding RNA-binding protein FUS have been linked to the development of a familial form of amyotrophic lateral sclerosis known as FUS-ALS. C-terminal truncations of FUS by either nonsense or frameshift mutations lead to the development of FUS-ALS with a particularly early onset and fast progression. However, even in patients bearing these highly pathogenic mutations the function of motor neurons is not noticeably compromised for at least a couple of decades, suggesting that until cytoplasmic levels of FUS lacking its C-terminal nuclear localisation signal reaches a critical threshold, motor neurons are able to tolerate its permanent production. In order to identify how the nervous system responds to low levels of pathogenic variants of FUS we produced and characterised a mouse line, L-FUS[1-359], with a low neuronal expression level of a highly aggregation-prone and pathogenic form of C-terminally truncated FUS. In contrast to mice that express substantially higher level of the same FUS variant and develop severe early onset motor neuron pathology, L-FUS[1-359] mice do not develop any clinical or histopathological signs of motor neuron deficiency even at old age. Nevertheless, we detected substantial changes in the spinal cord transcriptome of these mice compared to their wild type littermates. We suggest that at least some of these changes reflect activation of cellular mechanisms compensating for the potentially damaging effect of pathogenic FUS production. Further studies of these mechanism might reveal effective targets for therapy of FUS-ALS and possibly, other forms of ALS.

Behavioural impairments in mice of a novel FUS transgenic line recapitulate features of frontotemporal lobar degeneration.

Multiple clinical and experimental evidences suggest that amyotrophic lateral sclerosis (ALS) and frontotemporal lobar degeneration (FTLD) are members of a disease continuum. Pathological inclusions of fused in sarcoma (FUS) protein have been observed in subsets of patients with these diseases but their anatomical distribution is different for two diseases. These structures are present in motor neurons in ALS cases but in cortical neurons in FTLD cases. Expression of a C-terminally truncated form of human FUS causes an early onset and progressive motor neuron pathology in transgenic mice but only when these neurons express a certain level of this protein. Severe motor dysfunction and early lethality of mice with expression above this level prevent their use for studies of FTLD-related pathology caused by expression of this form of FUS. In the present study, we used another line of mice expressing the same protein but not developing any signs of motor system dysfunction due to substantially lower level of transgene expression in motor neurons. In a set of tests 5-month old mice displayed certain behavioural abnormalities, including increased impulsivity, decreased anxiety and compromised social interaction, which recapitulate behaviour characteristics typically seen in FTLD patients.

Stem cells in human breast milk.

Recent studies have demonstrated that breast milk contains a population of cells displaying many of the properties typical of stem cells. This review outlines progress made in this newly emerging field of stem cell biology and provides an analysis of the available data on purification, propagation and differentiation of certain types of progenitor cells from breast milk. The possible fates of breast milk cells, including microchimerism caused by their transmission to the distant organs of the infant, are also discussed. Unique properties of breast milk-derived stem cells, such as their unusually low tumorigenic potential and their negligible ability to form teratomas, are highlighted as obvious advantages for using these cells in regenerative therapy.

Generation of mouse lines with conditionally or constitutively inactivated Snca gene and Rosa26-stop-lacZ reporter located in cis on the mouse chromosome 6.

α-Synuclein is involved in many important molecular processes in neuronal cells and their synapses, and its malfunction has been linked to the development of Parkinson's and certain other neurodegenerative diseases. Animal models allowing tightly monitored conditional inactivation of the encoding gene, Snca, are indispensible for studies aimed at understanding normal function of α-synuclein in various neuronal populations and its role in pathogenesis of neurodegenerative diseases. We have recently reported the production of several novel mouse lines for manipulating expression of the endogenous Snca gene, including a line for Cre-recombinase-driven conditional inactivation of the gene (mice with floxed Snca) and a new line with a constitutive knockout of α-synuclein. Rosa26-stop-lacZ reporter cassette is commonly used for monitoring efficiency of Cre-recombination but in mouse genome Snca and Rosa26 loci are located on the same chromosome. Here we describe production of lines with a modified Snca locus, either floxed or constitutively inactivated and the Rosa26-stop-lacZ reporter cassette located in cis on the mouse chromosome 6. These new mouse lines are invaluable for fast identification of cells with inactivation of Snca by Cre-recombination and represent useful tools for in vivo studies of α-synuclein function and dysfunction.