A Platform for Studying Neurodegeneration Mechanisms Using Genetically Encoded Biosensors.

Patient-specific induced pluripotent stem cells (iPSCs) capable of differentiation into required cell type are a promising model for studying various pathological processes and development of new therapeutic approaches. However, no conventional strategies for using iPSCs in disease research have been established yet. Genetically encoded biosensors can be used for monitoring messenger molecules, metabolites, and enzyme activity in real time with the following conversion of the registered signals in quantitative data, thus allowing evaluation of the impact of certain molecules on pathology development. In this article, we describe the development of a universal cell-based platform for studying pathological processes associated with amyotrophic lateral sclerosis. For this purpose, we have created a series of plasmid constructs for monitoring endoplasmic reticulum stress, oxidative stress, apoptosis, and Ca2+-dependent hyperexcitability and generated transgenic iPSC line carrying mutation in the superoxide dismutase 1 gene (SOD1) and healthy control cell line. Both cell lines have specific transactivator sequence required for doxycycline-controlled transcriptional activation and can be used for a single-step biosensor insertion.

Generation of iPS cell line (ICGi040-A) from skin fibroblasts of a patient with ring small supernumerary marker chromosome 4.

Human induced pluripotent stem cell (iPSC) line, ICGi040-A, was obtained from skin fibroblasts derived from a male patient with mosaic ring small supernumerary marker chromosome 4 (sSMS(4)) and infertility. ICGi040-A cells have karyotype 47,XY,+r(4) in 97% of cells and express a set of pluripotent markers, as well as are able to differentiate in vitro into derivatives of all three embryonic germ layers.

Derivation of iPS cell line (ICGi032-A) from a patient affected with fragile X syndrome.

Trinucleotide repeat expansion diseases such as fragile X syndrome are of great interest to study since the mechanism of its development is still unknown. IPS cell lines are some of the most convenient models for studying. The ICGi032-A iPS cell line was obtained from the peripheral blood mononuclear cells of the patient affected with fragile X syndrome. ICGi032-A iPS cell line have a normal karyotype, expression of pluripotency markers and can differentiate in vitro into the cells of three germ layers.

Establishment of an induced pluripotent stem cell line (ICGi026-A) from peripheral blood mononuclear cells of a patient with fragile X syndrome.

Expansion over 200 CGG repeats in FMR1 gene causes inherited intellectual disability or autism spectrum disorder named as fragile X syndrome. Despite the known cause fragile X syndrome pathogenesis has not been specified yet. The ICGi026-A iPSCs line was obtained by the reprogramming of the peripheral blood mononuclear cells from a 9-year-old boy with fragile X syndrome. The ICGi026-A iPSCs expressed pluripotency markers, had a normal male karyotype (46, XY) and had the capacity to in vivo differentiate into the cells of three germ layers.

Establishment of an induced pluripotent stem cell line (ICGi025-A) from fibroblasts of a patient with 46,XY,r(8)/45,XY,-8 mosaicism.

Ring chromosomes are structural aberrations commonly associated with disease phenotype. We consider necessary to create the iPSCs with a ring chromosome 8, which can be used for disease modeling and related research. The ICGi025-A iPSCs line was obtained by the reprogramming of the skin fibroblasts from a 1-year-old boy with 46,XY,r(8)/45,XY,-8 mosaicism, developmental delay, microcephaly, dysmorphic features, diffuse muscle hypotonia, moderate proximal muscle weakness, feeding problems, and motor alalia. The iPSCs had expression of the pluripotency-associated markers. In vitro differentiated cells expressed the markers of the cells of three germ layers. That data allowed us to conclude that ICGi025-A cells were pluripotent.

Generation of two iPSC lines (ICGi008-A and ICGi008-B) from skin fibroblasts of a patient with early-onset Alzheimer's disease caused by London familial APP mutation (V717I).

The induced pluripotent stem cell (iPSC) lines ICGi008-A and ICGi008-B were generated from dermal fibroblasts using episomal vectors expressing pluripotency factors. Dermal fibroblasts were obtained from a 55 year old male Сaucasian familial Alzheimer's disease (AD) patient carrying heterozygous V717I mutation in the APP gene. The generated iPSC lines maintained the original APP genotype, expressed pluripotency markers, exhibited a normal karyotype and retained the ability to differentiate into cell types of the three germ layers. The iPSC lines will be useful for the study of the AD molecular and cellular mechanisms and drug screening.

Generation of induced pluripotent stem cell line, ICGi007-A, by reprogramming peripheral blood mononuclear cells from a patient with Huntington's disease.

Huntington's disease (HD) is an autosomal dominant neurodegenerative disease caused by mutation in the HTT gene encoding HTT protein. The mutant protein leads to the neuronal death through dysregulation of multiple cellular processes. HD human induced pluripotent stem cells (iPSCs) represent a useful and valid model for the disease study. iPSC line from HD patient with 47 CAG repeats in HTT was generated from blood mononuclear cells by non-integrating episomal vectors. The iPSC line retained the mutation, expressed pluripotency markers, had a normal karyotype and displayed in vitro differentiation to the three germ layers. Resource table.

Recombinogenic telomeres in diploid Sorex granarius (Soricidae, Eulipotyphla) fibroblast cells.

The telomere structure in the Iberian shrew Sorex granarius is characterized by unique, striking features, with short arms of acrocentric chromosomes carrying extremely long telomeres (up to 300 kb) with interspersed ribosomal DNA (rDNA) repeat blocks. In this work, we investigated the telomere physiology of S. granarius fibroblast cells and found that telomere repeats are transcribed on both strands and that there is no telomere-dependent senescence mechanism. Although telomerase activity is detectable throughout cell culture and appears to act on both short and long telomeres, we also discovered that signatures of a recombinogenic activity are omnipresent, including telomere-sister chromatid exchanges, formation of alternative lengthening of telomeres (ALT)-associated PML-like bodies, production of telomere circles, and a high frequency of telomeres carrying marks of a DNA damage response. Our results suggest that recombination participates in the maintenance of the very long telomeres in normal S. granarius fibroblasts. We discuss the possible interplay between the interspersed telomere and rDNA repeats in the stabilization of the very long telomeres in this organism.

Identification of all pachytene bivalents in the common shrew using DAPI-staining of synaptonemal complex spreads.

A major problem in studies of synaptonemal complexes (SC) is the difficulty in distinguishing individual chromosomes. This problem can be solved combining SC immunostaining with FISH of chromosome-specific sequences. However, this procedure is expensive, time-consuming and applicable only to a very limited number of species. In this paper we show how a combination of SC immunostaining and DAPI staining can allow identification of all chromosome arms in surface-spreads of the SC of the common shrew (Sorex araneus L.). Enhancement of brightness and contrast of the images with photo editing software allowed us to reveal clear DAPI-positive and negative bands with relative sizes and positions similar to DAPI landmarks on mitotic metaphase chromosomes. Using FISH with DNA probes prepared from chromosome arms m and n we demonstrated correct recognition of the chromosomes mp and hn on the basis of their DAPI pattern. We show that the approach we describe here may be applied to other species and can provide an important tool for identification of individual bivalents in pachytene surface-spreads.