Inimese tüvirakud ja rakuteraapia

Inimese tüvirakkude avastamine ja meetodikate väljatöötamine nende kasvatamiseks in vitro on loonud võimaluse autoloogilise rakuteraapia tekkeks. Koos tüvirakkude temaatikaga on viimasel kümnendil ühiskonna tähelepanu keskmesse kerkinud ka inimese ja loomade kloonimine. Teadusliku kontseptsioonina on nii tüvirakud kui ka kloonimine suhteliselt vanad valdkonnad. Efektiivse rakuteraapia areng eeldab täpseid teadmisi tüvi rakkude bioloogiast ja nendel teadmistel põhinevate meetodite loomist tüvirakkude suunatud kultiveerimiseks. Eesti Arst 2006; 85 (9): 565–56

CCL5/CCR1 axis regulates multipotency of human adipose tissue derived stromal cells

AbstractSeveral potential clinical applications of stem cells rely on their capacity to migrate into sites of inflammation where they contribute to tissue regeneration processes. Inflammatory signals are partially mediated by chemokines acting via their receptors expressed on the target cells. Data concerning the repertoire and biological activities of chemokine receptors in human adipose tissue derived stromal cells (ADSCs) are limited. Here we show that CCR1 is one of the few chemokine receptors expressed in ADSCs at a high level. CCR1 expression varies in ADSCs derived from different donors. It sharply decreases in the early phase of ADSCs in vitro propagation, but further demonstrates relative stability. Expression of CCR1 positively correlates with expression of SOX2, OCT4 and NANOG, transcription factors responsible for maintenance of the stemness properties of the cells. We demonstrate that signaling via CCL5/CCR1 axis triggers migration of ADSCs, activates ERK and AKT kinases, stimulates NFκB transcriptional activity and culminates in increased proliferation of CCR1+ cells accompanied with up-regulation of SOX2, OCT4 and NANOG expression. Our data suggest that chemokine signaling via CCR1 may be involved in regulation of stemness of ADSCs

Prostaglandin D2 Receptor DP1 Antibodies Predict Vaccine-induced and Spontaneous Narcolepsy Type 1 : Large-scale Study of Antibody Profiling

AbstractBackground Neuropathological findings support an autoimmune etiology as an underlying factor for loss of orexin-producing neurons in spontaneous narcolepsy type 1 (narcolepsy with cataplexy; sNT1) as well as in Pandemrix influenza vaccine-induced narcolepsy type 1 (Pdmx-NT1). The precise molecular target or antigens for the immune response have, however, remained elusive. Methods Here we have performed a comprehensive antigenic repertoire analysis of sera using the next-generation phage display method - mimotope variation analysis (MVA). Samples from 64 children and adolescents were analyzed: 10 with Pdmx-NT1, 6 with sNT1, 16 Pandemrix-vaccinated, 16 H1N1 infected, and 16 unvaccinated healthy individuals. The diagnosis of NT1 was defined by the American Academy of Sleep Medicine international criteria of sleep disorders v3. Findings Our data showed that although the immunoprofiles toward vaccination were generally similar in study groups, there were also striking differences in immunoprofiles between sNT1 and Pdmx-NT1 groups as compared with controls. Prominent immune response was observed to a peptide epitope derived from prostaglandin D2 receptor (DP1), as well as peptides homologous to B cell lymphoma 6 protein. Further validation confirmed that these can act as true antigenic targets in discriminating NT1 diseased along with a novel epitope of hemagglutinin of H1N1 to delineate exposure to H1N1. Interpretation We propose that DP1 is a novel molecular target of autoimmune response and presents a potential diagnostic biomarker for NT1. DP1 is involved in the regulation of non-rapid eye movement (NREM) sleep and thus alterations in its functions could contribute to the disturbed sleep regulation in NT1 that warrants further studies. Together our results also show that MVA is a helpful method for finding novel peptide antigens to classify human autoimmune diseases, possibly facilitating the design of better therapies.Peer reviewe

RNA-Seq Analysis Reveals Different Dynamics of Differentiation of Human Dermis- and Adipose-Derived Stromal Stem Cells

Tissue regeneration and recovery in the adult body depends on self-renewal and differentiation of stem and progenitor cells. Mesenchymal stem cells (MSCs) that have the ability to differentiate into various cell types, have been isolated from the stromal fraction of virtually all tissues. However, little is known about the true identity of MSCs. MSC populations exhibit great tissue-, location- and patient-specific variation in gene expression and are heterogeneous in cell composition.Our aim was to analyze the dynamics of differentiation of two closely related stromal cell types, adipose tissue-derived MSCs (AdMSCs) and dermal fibroblasts (FBs) along adipogenic, osteogenic and chondrogenic lineages using multiplex RNA-seq technology. We found that undifferentiated donor-matched AdMSCs and FBs are distinct populations that stay different upon differentiation into adipocytes, osteoblasts and chondrocytes. The changes in lineage-specific gene expression occur early in differentiation and persist over time in both AdMSCs and FBs. Further, AdMSCs and FBs exhibit similar dynamics of adipogenic and osteogenic differentiation but different dynamics of chondrogenic differentiation.Our findings suggest that stromal stem cells including AdMSCs and dermal FBs exploit different molecular mechanisms of differentiation to reach a common cell fate. The early mechanisms of differentiation are lineage-specific and are similar for adipogenic and osteogenic differentiation but are distinct for chondrogenic differentiation between AdMSCs and FBs

LXXLL Peptide Converts Transportan 10 to a Potent Inducer of Apoptosis in Breast Cancer Cells

Degenerate expression of transcription coregulator proteins is observed in most human cancers. Therefore, in targeted anti-cancer therapy development, intervention at the level of cancer-specific transcription is of high interest. The steroid receptor coactivator-1 (SRC-1) is highly expressed in breast, endometrial, and prostate cancer. It is present in various transcription complexes, including those containing nuclear hormone receptors. We examined the effects of a peptide that contains the LXXLL-motif of the human SRC-1 nuclear receptor box 1 linked to the cell-penetrating transportan 10 (TP10), hereafter referred to as TP10-SRC1LXXLL, on proliferation and estrogen-mediated transcription of breast cancer cells in vitro. Our data show that TP10-SRC1LXXLL induced dose-dependent cell death of breast cancer cells, and that this effect was not affected by estrogen receptor (ER) status. Surprisingly TP10-SRC1LXXLL severely reduced the viability and proliferation of hormone-unresponsive breast cancer MDA-MB-231 cells. In addition, the regulation of the endogenous ERα direct target gene pS2 was not affected by TP10-SRC1LXXLL in estrogen-stimulated MCF-7 cells. Dermal fibroblasts were similarly affected by treatment with higher concentrations of TP10-SRC1LXXLL and this effect was significantly delayed. These results suggest that the TP10-SRC1LXXLL peptide may be an effective drug candidate in the treatment of cancers with minimal therapeutic options, for example ER-negative tumors

Graphene-augmented nanofiber scaffolds demonstrate new features in cells behaviour

Three-dimensional (3D) customized scaffolds capable to mimic a native extracellular matrix open new frontiers in cells manipulation and advanced therapy. The major challenge is in a proper substrate for in vitro models on engineered scaffolds, capable to modulate cells differentiation. Here for the first time we demonstrate novel design and functionality of the 3D porous scaffolds of aligned, self-assembled ceramic nanofibers of ultra-high anisotropy ratio (∼10 7), augmented into graphene shells. This unique hybrid nano-network allows an exceptional combination of selective guidance stimuli of stem cells differentiation, immune reactions variations, and local immobilization of cancer cells, which was not available before. The scaffolds were shown to be able to direct human mesenchymal stem cells (important for stimulation of neuronal and muscle cells) preferential orientation, to suppress major inflammatory factors, and to localize cancer cells; all without additions of specific culture media. The selective downregulation of specific cytokines is anticipated as a new tool for understanding of human immune system and ways of treatment of associated diseases. The effects observed are self-regulated by cells only, without side effects, usually arising from use of external factors. New scaffolds may open new horizons for stem cells fate control such as towards axons and neurites regeneration (Alzheimer's disease) as well as cancer therapy development.Peer reviewe

Graphene-Augmented Nanofiber Scaffolds Trigger Gene Expressions Switching of Four Cancer Cell Types

Three-dimensional (3D) customized scaffolds are anticipated in providing new frontiers in cells manipulation and advanced therapy methods. Here we demonstrate the application of hybrid 3D porous scaffolds, representing networks of highly aligned self-assembled ceramic nano-fibers, for culturing four types of cancer cells. Ultra-high aspect ratio (~~107) of graphene augmented fibers of tailored nano-topology is shown as an alternative tool to substantially affect cancerous gene expression, eventually due to differences in local biomechanical features of the cell-matrix interactions. Here we report a clear selective up- and down-regulation of groups of markers for breast cancer (MDA-MB231), colorectal cancer (CaCO2), melanoma (WM239A) and neuroblastoma (Kelly) depending on only fibers orientation and morphology without application of any other stimulus. Changes in gene expression are also revealed for Mitomycin C treatment of MDA-MB231, making the scaffold a suitable platform for testing of anticancer agents. This allows an opportunity for selective »clean» guidance to deep understanding mechanisms of cancer cells progressive growth and tumor formation without possible side effects by manipulation with the specific markers.Peer reviewe

Distinctly expressed genes between undifferentiated AdMSCs and FBs (based on ANOVA with FDR of 1%).

<p>Distinctly expressed genes between undifferentiated AdMSCs and FBs (based on ANOVA with FDR of 1%).</p