47 results on '"Danielyan L"'
Search Results
2. The Role of the Adrenergic System in Neurodegeneration and Oxidative Stress-Induced Damage to the Brain
- Author
-
Manukyan, A. L., Hunanyan, L. S., Sukiasyan, L. M., Frey II, W. H., Yenkoyan, K. B., Danielyan, L. G., and Melkonyan, M. M.
- Published
- 2023
- Full Text
- View/download PDF
3. Impaired Synthesis of Erythropoietin, Glutamine Synthetase and Metallothionein in the Skin of NOD/SCID/γcnull and Foxn1 nu/nu Mice with Misbalanced Production of MHC Class II Complex
- Author
-
Danielyan, L., Verleysdonk, S., Buadze, M., Gleiter, C. H., and Buniatian, G. H.
- Published
- 2010
- Full Text
- View/download PDF
4. Expression of glial fibrillary acidic protein in the rat endocard, cardiac interstitial Cajal-like cells, and perivascular structures of the spleen
- Author
-
Danielyan, L. G., Gebhardt, R., and Buniatian, G. H.
- Published
- 2008
- Full Text
- View/download PDF
5. “SMART EDUCATION” AS AN EFFECTIVE TOOL FOR INTERACTION BETWEEN THE STATE AND THE PRIVATE SECTOR
- Author
-
Suvaryan, A., primary, Avetyan, A., additional, and Danielyan, L., additional
- Published
- 2021
- Full Text
- View/download PDF
6. Dry carbon dioxide baths in complex spa treatment of children and adolescents with diseases of the cardiovascular system
- Author
-
Kaisinova, A. S., primary, Kulakovskaya, T. V., additional, Danielyan, L. G., additional, Cheparina, G. P., additional, and Chalaya, E. N., additional
- Published
- 2020
- Full Text
- View/download PDF
7. Development of liquid flow in a plane channel with moving permeable walls
- Author
-
Babadzhanyan, G. A., Danielyan, L. E., and Mnatsakanyan, R. Zh.
- Published
- 1997
- Full Text
- View/download PDF
8. THE ASSIMILATION OF VARIOUS PLANT GUMS BY THE LACTOBACILLUS CASEI LH26 STRAIN ISOLATED FROM BREAST MILK.
- Author
-
Danielyan, L. V.
- Subjects
- *
GUMS & resins , *BREAST milk , *LACTOBACILLUS casei , *PROBIOTICS , *PLANT assimilation , *APRICOT - Abstract
Breast milk contains beneficial microorganisms (probiotics) and a large amount of complex oligosaccharides, mainly galactooligosaccharides (GOS), which act as prebiotics and promote the growth and maintenance of probiotic bacteria in the infant's gut. The results of the studies refer to assimilation of inulin and gums of plant origin by lactobacilli isolated from breast milk are presented. It is shown that inulin is not inferior to glucose in terms of the efficiency of use and biomass accumulation, while the gums of the Acacia Senegal and apricot tree are only partially digested by lactobacilli and form much less biomass. On the other hand, plant gums have been found to protect lactobacilli from harmful environmental factors and thus contribute to the long-term preservation of their viability. Further research on gums as substitutes for breast milk oligosaccharides to increase and maintain the viability of lactobacillus may be the basis for creating a new formula for children. [ABSTRACT FROM AUTHOR]
- Published
- 2021
9. Effect of temperature and slope of a gas main in nonisothermal unsteady gas movement
- Author
-
Danielyan, L. E.
- Published
- 1976
- Full Text
- View/download PDF
10. QUALITY OF LIFE OF CHILDREN WITH RICKETS IN YOUNG AGE IN ARMENIA.
- Author
-
Dunamalyan, R., Mardiyan, M., Danielyan, L., Mkrtchyan, S., and Chopikyan, A.
- Published
- 2017
11. Impaired Synthesis of Erythropoietin, Glutamine Synthetase and Metallothionein in the Skin of NOD/SCID/γ c null and Foxn1 nu/nu Mice with Misbalanced Production of MHC Class II Complex
- Author
-
Danielyan, L., primary, Verleysdonk, S., additional, Buadze, M., additional, Gleiter, C. H., additional, and Buniatian, G. H., additional
- Published
- 2009
- Full Text
- View/download PDF
12. Survival, neuron-like differentiation and functionality of mesenchymal stem cells in neurotoxic environment: the critical role of erythropoietin
- Author
-
Danielyan, L, primary, Schäfer, R, additional, Schulz, A, additional, Ladewig, T, additional, Lourhmati, A, additional, Buadze, M, additional, Schmitt, A L, additional, Verleysdonk, S, additional, Kabisch, D, additional, Koeppen, K, additional, Siegel, G, additional, Proksch, B, additional, Kluba, T, additional, Eckert, A, additional, Köhle, C, additional, Schöneberg, T, additional, Northoff, H, additional, Schwab, M, additional, and Gleiter, C H, additional
- Published
- 2009
- Full Text
- View/download PDF
13. The main issues of enhancement of the effectiveness of medical services provided to the children's population in Republic Armenia.
- Author
-
MARDIYAN, M. A., CHOPIKYAN, A. S., BARSEGHYAN, A. A., DANIELYAN, L. M., and DUNAMALYAN, R. A.
- Abstract
Recently the indicators characterizing health state development of population in Armenia have undergone various negative and structural changes. To soften the negative influence of indicators in 2011 "Child's Health State Certificate" program was implemented. Consequently sharp rise of the number of served cases was detected. To abolish the existing defects funding of completed cases and appropriate payment provision should be done in outpatient service. Mandatory conditions for completed cases are diagnosis, appropriate laboratory, instrumental investigations, treatment prescription, approprate supervision, treatment outcome: cure, amelioration, medical treatment referral absence during the sequential 5 days with the same diagnosis. Usage of the mentioned mechanism will make direct and visible connection between the amounts of services provided by doctors and received salary, which will boost doctors' work efficiency and make conditions to reduce groundless referrals to medical institutions. [ABSTRACT FROM AUTHOR]
- Published
- 2014
- Full Text
- View/download PDF
14. Hepatic Amyloid Beta-42-Metabolizing Proteins in Liver Steatosis and Metabolic Dysfunction-Associated Steatohepatitis.
- Author
-
Gross S, Danielyan L, Buechler C, Kubitza M, Klein K, Schwab M, Melter M, and Weiss TS
- Subjects
- Animals, Humans, Mice, Male, Amyloid beta-Protein Precursor metabolism, Amyloid beta-Protein Precursor genetics, Peptide Fragments metabolism, Mice, Inbred C57BL, Hepatocytes metabolism, Hepatocytes pathology, Female, Disease Models, Animal, Neprilysin metabolism, Neprilysin genetics, Amyloid beta-Peptides metabolism, Fatty Liver metabolism, Fatty Liver pathology, Liver metabolism, Liver pathology
- Abstract
Amyloid beta (Aβ) plays a major role in the pathogenesis of Alzheimer's disease and, more recently, has been shown to protect against liver fibrosis. Therefore, we studied Aβ-42 levels and the expression of genes involved in the generation, degradation, and transport of Aβ proteins in liver samples from patients at different stages of metabolic dysfunction-associated liver disease (MASLD) and under steatotic conditions in vitro/in vivo. Amyloid precursor protein (APP), key Aβ-metabolizing proteins, and Aβ-42 were analyzed using RT-PCR, Western blotting, Luminex analysis in steatotic in vitro and fatty liver mouse models, and TaqMan qRT-PCR analysis in hepatic samples from patients with MASLD. Hepatocytes loaded with palmitic acid induced APP, presenilin, and neprilysin (NEP) expression, which was reversed by oleic acid. Increased APP and NEP, decreased BACE1, and unchanged Aβ-42 protein levels were found in the steatotic mouse liver compared to the normal liver. Aβ-42 concentrations were low in MASLD samples of patients with moderate to severe fibrosis compared to the livers of patients with mild or no MASLD. Consistent with the reduced Aβ-42 levels, the mRNA expression of proteins involved in APP degradation (ADAM9/10/17, BACE2) and Aβ-42 cleavage (MMP2/7/9, ACE) was increased. In the steatotic liver, the expression of APP- and Aβ-metabolizing proteins is increased, most likely related to oxidative stress, but does not affect hepatic Aβ-42 levels. Consistent with our previous findings, low Aβ-42 levels in patients with liver fibrosis appear to be caused by the reduced production and enhanced non-amyloidogenic processing of APP.
- Published
- 2024
- Full Text
- View/download PDF
15. Consequences of Amyloid-β Deficiency for the Liver.
- Author
-
Buniatian GH, Schwinghammer U, Tremmel R, Cynis H, Weiss TS, Weiskirchen R, Lauschke VM, Youhanna S, Ramos I, Valcarcel M, Seferyan T, Rahfeld JU, Rieckmann V, Klein K, Buadze M, Weber V, Kolak V, Gebhardt R, Friedman SL, Müller UC, Schwab M, and Danielyan L
- Subjects
- Animals, Humans, Mice, Disease Models, Animal, Mice, Inbred C57BL, Mice, Knockout, Alzheimer Disease metabolism, Alzheimer Disease genetics, Alzheimer Disease pathology, Amyloid beta-Peptides metabolism, Amyloid beta-Peptides genetics, Liver metabolism, Liver pathology, Mice, Transgenic
- Abstract
The hepatic content of amyloid beta (Aβ) decreases drastically in human and rodent cirrhosis highlighting the importance of understanding the consequences of Aβ deficiency in the liver. This is especially relevant in view of recent advances in anti-Aβ therapies for Alzheimer's disease (AD). Here, it is shown that partial hepatic loss of Aβ in transgenic AD mice immunized with Aβ antibody 3D6 and its absence in amyloid precursor protein (APP) knockout mice (APP-KO), as well as in human liver spheroids with APP knockdown upregulates classical hallmarks of fibrosis, smooth muscle alpha-actin, and collagen type I. Aβ absence in APP-KO and deficiency in immunized mice lead to strong activation of transforming growth factor-β (TGFβ), alpha secretases, NOTCH pathway, inflammation, decreased permeability of liver sinusoids, and epithelial-mesenchymal transition. Inversely, increased systemic and intrahepatic levels of Aβ42 in transgenic AD mice and neprilysin inhibitor LBQ657-treated wild-type mice protect the liver against carbon tetrachloride (CCl
4 )-induced injury. Transcriptomic analysis of CCl4 -treated transgenic AD mouse livers uncovers the regulatory effects of Aβ42 on mitochondrial function, lipid metabolism, and its onco-suppressive effects accompanied by reduced synthesis of extracellular matrix proteins. Combined, these data reveal Aβ as an indispensable regulator of cell-cell interactions in healthy liver and a powerful protector against liver fibrosis., (© 2024 The Authors. Advanced Science published by Wiley‐VCH GmbH.)- Published
- 2024
- Full Text
- View/download PDF
16. Intravenous MSC-Treatment Improves Impaired Brain Functions in the R6/2 Mouse Model of Huntington's Disease via Recovered Hepatic Pathological Changes.
- Author
-
Yu-Taeger L, El-Ayoubi A, Qi P, Danielyan L, and Nguyen HHP
- Subjects
- Mice, Humans, Animals, Mice, Transgenic, Disease Models, Animal, Brain metabolism, Liver metabolism, Huntington Disease metabolism
- Abstract
Huntington's disease (HD), a congenital neurodegenerative disorder, extends its pathological damages beyond the nervous system. The systematic manifestation of HD has been extensively described in numerous studies, including dysfunction in peripheral organs and peripheral inflammation. Gut dysbiosis and the gut-liver-brain axis have garnered greater emphasis in neurodegenerative research, and increased plasma levels of pro-inflammatory cytokines have been identified in HD patients and various in vivo models, correlating with disease progression. In the present study, we investigated hepatic pathological markers in the liver of R6/2 mice which convey exon 1 of the human mutant huntingtin gene. Furthermore, we evaluated the impact of intravenously administered Mesenchymal Stromal Cells (MSCs) on the liver enzymes, changes in hepatic inflammatory markers, as well as brain pathology and behavioral deficits in R6/2 mice. Our results revealed altered enzyme expression and increased levels of inflammatory mediators in the liver of R6/2 mice, which were significantly attenuated in the MSC-treated R6/2 mice. Remarkably, neuronal pathology and altered motor activities in the MSC-treated R6/2 mice were significantly ameliorated, despite the absence of MSCs in the postmortem brain. Our data highlight the importance of hepatic pathological changes in HD, providing a potential therapeutic approach. Moreover, the data open new perspectives for the search in blood biomarkers correlating with liver pathology in HD.
- Published
- 2024
- Full Text
- View/download PDF
17. Development of an optimized, non-stem cell line for intranasal delivery of therapeutic cargo to the central nervous system.
- Author
-
El-Ayoubi A, Arakelyan A, Klawitter M, Merk L, Hakobyan S, Gonzalez-Menendez I, Quintanilla Fend L, Holm PS, Mikulits W, Schwab M, Danielyan L, and Naumann U
- Subjects
- Mice, Humans, Animals, Administration, Intranasal, Cell Line, Central Nervous System metabolism, Thymidine Kinase genetics, Thymidine Kinase metabolism, Thymidine Kinase therapeutic use, Antiviral Agents, Genetic Therapy
- Abstract
Neural stem cells (NSCs) are considered to be valuable candidates for delivering a variety of anti-cancer agents, including oncolytic viruses, to brain tumors. However, owing to the previously reported tumorigenic potential of NSC cell lines after intranasal administration (INA), here we identified the human hepatic stellate cell line LX-2 as a cell type capable of longer resistance to replication of oncolytic adenoviruses (OAVs) as a therapeutic cargo, and that is non-tumorigenic after INA. Our data show that LX-2 cells can longer withstand the OAV XVir-N-31 replication and oncolysis than NSCs. By selecting the highly migratory cell population out of LX-2, an offspring cell line with a higher and more stable capability to migrate was generated. Additionally, as a safety backup, we applied genomic herpes simplex virus thymidine kinase (HSV-TK) integration into LX-2, leading to high vulnerability to ganciclovir (GCV). Histopathological analyses confirmed the absence of neoplasia in the respiratory tracts and brains of immuno-compromised mice 3 months after INA of LX-2 cells. Our data suggest that LX-2 is a novel, robust, and safe cell line for delivering anti-cancer and other therapeutic agents to the brain., (© 2023 The Authors. Molecular Oncology published by John Wiley & Sons Ltd on behalf of Federation of European Biochemical Societies.)
- Published
- 2024
- Full Text
- View/download PDF
18. Intranasal Delivery of Oncolytic Adenovirus XVir-N-31 via Optimized Shuttle Cells Significantly Extends Survival of Glioblastoma-Bearing Mice.
- Author
-
El-Ayoubi A, Klawitter M, Rüttinger J, Wellhäusser G, Holm PS, Danielyan L, and Naumann U
- Abstract
A glioblastoma (GBM) is an aggressive and lethal primary brain tumor with restricted treatment options and a dismal prognosis. Oncolytic virotherapy (OVT) has developed as a promising approach for GBM treatment. However, reaching invasive GBM cells may be hindered by tumor-surrounding, non-neoplastic cells when the oncolytic virus (OV) is applied intratumorally. Using two xenograft GBM mouse models and immunofluorescence analyses, we investigated the intranasal delivery of the oncolytic adenovirus (OAV) XVir-N-31 via virus-loaded, optimized shuttle cells. Intranasal administration (INA) was selected due to its non-invasive nature and the potential to bypass the blood-brain barrier (BBB). Our findings demonstrate that the INA of XVir-N-31-loaded shuttle cells successfully delivered OAVs to the core tumor and invasive GBM cells, significantly prolonged the survival of the GBM-bearing mice, induced immunogenic cell death and finally reduced the tumor burden, all this highlighting the therapeutic potential of this innovative approach. Overall, this study provides compelling evidence for the effectiveness of the INA of XVir-N-31 via shuttle cells as a promising therapeutic strategy for GBM. The non-invasive nature of the INA of OV-loaded shuttle cells holds great promise for future clinical translation. However, further research is required to assess the efficacy of this approach to ultimately progress in human clinical trials.
- Published
- 2023
- Full Text
- View/download PDF
19. NEW APPROACHES TO THE EVALUATION OF HERBAL DRUG EFFICACY IN CHRONIC RHINOSINUSITIS TREATMENT SCHEME BASED ON CHANGES OF QUALITY-OF-LIFE CRITERIA.
- Author
-
Mkrtchyan S, Shukuryan A, Dunamalyan R, Sakanyan G, Varuzhanyan H, Danielyan L, Galstyan H, and Mardiyan M
- Subjects
- Humans, Quality of Life, Reproducibility of Results, Chronic Disease, Rhinitis drug therapy, Sinusitis drug therapy
- Abstract
Assessment of quality of life (QOL) is one of the key criteria for evaluating the effectiveness of treatment in clinical trials. It is very important to pay attention to the methods of evaluation and analysis. Health-related quality of life is very important in evaluating drug efficacy. The assessment of this indicator in clinical trials is considered as an additional indicator of drug efficacy, a new tool for choosing an effective drug for clinical practice, etc. To assess the quality of life of patients with chronic rhinosinusitis and select an effective drug such as "Gutanos" (anti-inflammatory, antimicrobial nasal drops of plant origin), we followed the recommended steps for cultural adaptation of SNOT-22 into Armenian, creating a tool for assessing patients with clinically significant sinonasal disorders. (rhinosinusitis), as well as for scientific research (Cronbach index = 0.81), the reliability of the test-retest was determined (ICC = 0.85). We found that SNOT-22 is reliable, easy to use, and can be used to facilitate daily clinical practice to highlight the impact of chronic rhinosinusitis on patients' quality of life.
- Published
- 2023
20. Serum Amyloid Beta42 Is Not Eliminated by the Cirrhotic Liver: A Pilot Study.
- Author
-
Wiest R, Weiss TS, Danielyan L, and Buechler C
- Abstract
Amyloid-beta (Aβ) deposition in the brain is the main pathological hallmark of Alzheimer disease. Peripheral clearance of Aβ may possibly also lower brain levels. Recent evidence suggested that hepatic clearance of Aβ42 is impaired in liver cirrhosis. To further test this hypothesis, serum Aβ42 was measured by ELISA in portal venous serum (PVS), systemic venous serum (SVS), and hepatic venous serum (HVS) of 20 patients with liver cirrhosis. Mean Aβ42 level was 24.7 ± 20.4 pg/mL in PVS, 21.2 ± 16.7 pg/mL in HVS, and 19.2 ± 11.7 pg/mL in SVS. Similar levels in the three blood compartments suggested that the cirrhotic liver does not clear Aβ42. Aβ42 was neither associated with the model of end-stage liver disease score nor the Child-Pugh score. Patients with abnormal creatinine or bilirubin levels or prolonged prothrombin time did not display higher Aβ42 levels. Patients with massive ascites and patients with large varices had serum Aβ42 levels similar to patients without these complications. Serum Aβ42 was negatively associated with connective tissue growth factor levels (r = -0.580, p = 0.007) and a protective role of Aβ42 in fibrogenesis was already described. Diabetic patients with liver cirrhosis had higher Aβ42 levels ( p = 0.069 for PVS, p = 0.047 for HVS and p = 0.181 for SVS), which is in accordance with previous reports. Present analysis showed that the cirrhotic liver does not eliminate Aβ42. Further studies are needed to explore the association of liver cirrhosis, Aβ42 levels, and cognitive dysfunction.
- Published
- 2021
- Full Text
- View/download PDF
21. Alpha2-Adrenoblockers Regulate Development of Oxidative Stress and Cognitive Behaviour of Rats under Chronic Acoustic Stress Conditions.
- Author
-
Melkonyan M, Manukyan A, Hunanyan L, Grigoryan A, Harutyunyan H, Sukiasyan L, Danielyan L, and Yenkoyan K
- Abstract
Noise is a wide-spread stress factor in modern life produced by urbanization, traffic, and an industrialized environment. Noise stress causes dysfunction and neurotransmission impairment in the central nervous system, as well as changes in hormone levels. In this study, we have examined the level of α-Tocopherol (α-T) and malondialdehyde (MDA) in plasma and the erythrocytes' membrane (EM), as well as the behavioral characteristics of a noise-induced stress model in rats. In addition, the modulating effect of α
2 -adrenoblockers, beditin, and mesedin on the aforementioned parameters has been investigated. For these purposes, albino male rats were divided into four groups: (1) untreated; (2) noise-exposed, (3) noise-exposed and beditin-treated (2 mg/kg, i.p.), and (4) noise-exposed and mesedin-treated (10 mg/kg, i.p.) animals. Noise-exposed groups were treated with 91dBA noise on 60 days with a daily duration of 8 h. Increased MDA and decreased α-T levels in plasma and EM were observed upon chronic high-level noise exposure. Locomotor and behavioral activity assessed with a Y-maze revealed disorientation and increased anxiety under chronic noise exposure. Prominently, α2 -adrenoblockers alleviated both behavioral deficits and oxidative stress, providing evidence for the involvement of α2 -adrenoceptor in the pathophysiology of noise-induced stress.- Published
- 2021
- Full Text
- View/download PDF
22. The Novel Alpha-2 Adrenoceptor Inhibitor Beditin Reduces Cytotoxicity and Huntingtin Aggregates in Cell Models of Huntington's Disease.
- Author
-
Singer E, Hunanyan L, Melkonyan MM, Weber JJ, Danielyan L, and Nguyen HP
- Abstract
Huntington's disease (HD) is a monogenetic neurodegenerative disorder characterized by the accumulation of polyglutamine-expanded huntingtin (mHTT). There is currently no cure, and therefore disease-slowing remedies are sought to alleviate symptoms of the multifaceted disorder. Encouraging findings in Alzheimer's and Parkinson's disease on alpha-2 adrenoceptor (α2-AR) inhibition have shown neuroprotective and aggregation-reducing effects in cell and animal models. Here, we analyzed the effect of beditin, a novel α2- adrenoceptor (AR) antagonist, on cell viability and mHTT protein levels in cell models of HD using Western blot, time-resolved Foerster resonance energy transfer (TR-FRET), lactate dehydrogenase (LDH) and terminal deoxynucleotidyl transferase dUTP nick end labeling (TUNEL) cytotoxicity assays. Beditin decreases cytotoxicity, as measured by TUNEL staining and LDH release, in a neuronal progenitor cell model (ST Hdh cells) of HD and decreases the aggregation propensity of HTT exon 1 fragments in an overexpression model using human embryonic kidney (HEK) 293T cells. α2-AR is a promising therapeutic target for further characterization in HD models. Our data allow us to suggest beditin as a valuable candidate for the pharmaceutical manipulation of α2-AR, as it is capable of modulating neuronal cell survival and the level of mHTT.
- Published
- 2021
- Full Text
- View/download PDF
23. Losartan Improves Memory, Neurogenesis and Cell Motility in Transgenic Alzheimer's Mice.
- Author
-
Drews HJ, Klein R, Lourhmati A, Buadze M, Schaeffeler E, Lang T, Seferyan T, Hanson LR, Frey Ii WH, de Vries TCGM, Thijssen-van Loosdregt IAEW, Gleiter CH, Schwab M, and Danielyan L
- Abstract
Angiotensin receptor blockers (ARBs) have demonstrated multiple neuroprotective benefits in Alzheimer's disease (AD) models. However, their beneficial effects on memory deficits, cholinergic activity, neurogenesis and Amyloid beta (Aβ) clearance reveal significant interstudy variability. The delivery route can impact not only delivery but also targeting and therapeutic efficacy of ARBs. Our previous findings on the beneficial effects of intranasally delivered losartan in the APP/PS1 model of AD prompted us to explore the influence of the delivery route by employing here the systemic administration of losartan. Consistent with our previous results with intranasal losartan, repeated intraperitoneal administration (10 mg/kg) resulted in a remarkable decrease in Aβ plaques and soluble Aβ42, as well as inflammatory cytokines (IL-2, IL-6 and TNFα). The Aβ reduction can be ascribed to its facilitated degradation by neprilysin and diminished generation by BACE1. Losartan increased neurogenesis in vivo and in vitro and improved migratory properties of astrocytes isolated from adult transgenic AD mice. In summary, this data together with our previous results suggest therapeutic features of losartan which are independent of delivery route. The improvement of cell motility of Aβ-affected astrocytes by losartan deserves further in vivo investigation, which may lead to new strategies for AD treatment.
- Published
- 2021
- Full Text
- View/download PDF
24. Cell motility and migration as determinants of stem cell efficacy.
- Author
-
Danielyan L, Schwab M, Siegel G, Brawek B, Garaschuk O, Asavapanumas N, Buadze M, Lourhmati A, Wendel HP, Avci-Adali M, Krueger MA, Calaminus C, Naumann U, Winter S, Schaeffeler E, Spogis A, Beer-Hammer S, Neher JJ, Spohn G, Kretschmer A, Krämer-Albers EM, Barth K, Lee HJ, Kim SU, Frey WH 2nd, Claussen CD, Hermann DM, Doeppner TR, Seifried E, Gleiter CH, Northoff H, and Schäfer R
- Subjects
- Alzheimer Disease therapy, Animals, Biomarkers, Cell Survival, Cell Tracking methods, Cells, Cultured, Disease Models, Animal, Gene Expression, Gene Expression Profiling, Humans, Male, Membrane Glycoproteins genetics, Membrane Glycoproteins metabolism, Mesenchymal Stem Cells cytology, Mesenchymal Stem Cells physiology, Mice, Mice, Transgenic, Neural Stem Cells cytology, Neural Stem Cells physiology, Oncolytic Virotherapy, Stem Cell Transplantation, Stem Cells cytology, Treatment Outcome, Cell Movement, Stem Cells physiology
- Abstract
Background: Stem cells` (SC) functional heterogeneity and its poorly understood aetiology impedes clinical development of cell-based therapies in regenerative medicine and oncology. Recent studies suggest a strong correlation between the SC migration potential and their therapeutic efficacy in humans. Designating SC migration as a denominator of functional SC heterogeneity, we sought to identify highly migrating subpopulations within different SC classes and evaluate their therapeutic properties in comparison to the parental non-selected cells., Methods: We selected highly migrating subpopulations from mesenchymal and neural SC (sMSC and sNSC), characterized their features including but not limited to migratory potential, trophic factor release and transcriptomic signature. To assess lesion-targeted migration and therapeutic properties of isolated subpopulations in vivo, surgical transplantation and intranasal administration of MSCs in mouse models of glioblastoma and Alzheimer's disease respectively were performed., Findings: Comparison of parental non-selected cells with isolated subpopulations revealed superior motility and migratory potential of sMSC and sNSC in vitro. We identified podoplanin as a major regulator of migratory features of sMSC/sNSC. Podoplanin engineering improved oncovirolytic activity of virus-loaded NSC on distantly located glioblastoma cells. Finally, sMSC displayed more targeted migration to the tumour site in a mouse glioblastoma model and remarkably higher potency to reduce pathological hallmarks and memory deficits in transgenic Alzheimer's disease mice., Interpretation: Functional heterogeneity of SC is associated with their motility and migration potential which can serve as predictors of SC therapeutic efficacy., Funding: This work was supported in part by the Robert Bosch Stiftung (Stuttgart, Germany) and by the IZEPHA grant., Competing Interests: Declaration of Competing Interest Dr. Danielyan reports grants from IZEPHA, during the conduct of the study. Prof.. Schwab, Dr. Schaeffeler and Dr. Winter report grants from Robert Bosch Stiftung (Stuttgart, Germany), during the conduct of the study. Dr. Danielyan, Dr. Schäfer, Prof. Gleiter and Prof. Schwab have a patent US14/634,501, US14/634,484, PCT/EP2016/054055, DE102012107879, EP2888348 pending. All other authors have no competing interests., (Copyright © 2020 The Authors. Published by Elsevier B.V. All rights reserved.)
- Published
- 2020
- Full Text
- View/download PDF
25. Modulating endothelial adhesion and migration impacts stem cell therapies efficacy.
- Author
-
Schäfer R, Schwab M, Siegel G, von Ameln-Mayerhofer A, Buadze M, Lourhmati A, Wendel HP, Kluba T, Krueger MA, Calaminus C, Scheer E, Dominici M, Grisendi G, Doeppner TR, Schlechter J, Finzel AK, Gross D, Klaffschenkel R, Gehring FK, Spohn G, Kretschmer A, Bieback K, Krämer-Albers EM, Barth K, Eckert A, Elser S, Schmehl J, Claussen CD, Seifried E, Hermann DM, Northoff H, and Danielyan L
- Subjects
- Animals, Biomarkers, Cell Differentiation, Cell Line, Cell- and Tissue-Based Therapy, Cells, Cultured, Cellular Microenvironment, Disease Models, Animal, Glioma diagnosis, Glioma pathology, Glioma therapy, Humans, Immunophenotyping, Mesenchymal Stem Cell Transplantation, Mesenchymal Stem Cells metabolism, Mice, Rats, Stem Cell Transplantation, Xenograft Model Antitumor Assays, Cell Adhesion, Cell Movement, Endothelium metabolism, Stem Cells metabolism
- Abstract
Background: Limited knowledge of stem cell therapies` mechanisms of action hampers their sustainable implementation into the clinic. Specifically, the interactions of transplanted stem cells with the host vasculature and its implications for their therapeutic efficacy are not elucidated. We tested whether adhesion receptors and chemokine receptors on stem cells can be functionally modulated, and consequently if such modulation may substantially affect therapeutically relevant stem cell interactions with the host endothelium., Methods: We investigated the effects of cationic molecule polyethylenimine (PEI) treatment with or without nanoparticles on the functions of adhesion receptors and chemokine receptors of human bone marrow-derived Mesenchymal Stem Cells (MSC). Analyses included MSC functions in vitro, as well as homing and therapeutic efficacy in rodent models of central nervous system´s pathologies in vivo., Findings: PEI treatment did not affect viability, immunomodulation or differentiation potential of MSC, but increased the CCR4 expression and functionally blocked their adhesion receptors, thus decreasing their adhesion capacity in vitro. Intravenously applied in a rat model of brain injury, the homing rate of PEI-MSC in the brain was highly increased with decreased numbers of adherent PEI-MSC in the lung vasculature. Moreover, in comparison to untreated MSC, PEI-MSC featured increased tumour directed migration in a mouse glioblastoma model, and superior therapeutic efficacy in a murine model of stroke., Interpretation: Balanced stem cell adhesion and migration in different parts of the vasculature and tissues together with the local microenvironment impacts their therapeutic efficacy., Funding: Robert Bosch Stiftung, IZEPHA grant, EU grant 7 FP Health., Competing Interests: Declaration of Competing Interest Dr. Danielyan reports grants from IZEPHA, during the conduct of the study. Dr. Schwab reports grants from Robert Bosch Stiftung (Stuttgart, Germany) during the conduct of the study. Dr. Schäfer reports a grant from the Commission of the European Communities during the conduct of the study. Dres Schäfer, Danielyan, von Ameln-Mayerhofer, Wendel, Kluba, Dominici, Claussen, Northoff and Siegel have a patent DE102012111891.4.; EP13801557.3. Dr. Gehring is a shareholder of 3T analytic. All other authors have no competing interests., (Copyright © 2020 The Authors. Published by Elsevier B.V. All rights reserved.)
- Published
- 2020
- Full Text
- View/download PDF
26. α2-Adrenergic Receptor in Liver Fibrosis: Implications for the Adrenoblocker Mesedin.
- Author
-
Schwinghammer UA, Melkonyan MM, Hunanyan L, Tremmel R, Weiskirchen R, Borkham-Kamphorst E, Schaeffeler E, Seferyan T, Mikulits W, Yenkoyan K, Schwab M, and Danielyan L
- Subjects
- Adrenergic alpha-2 Receptor Antagonists pharmacology, Animals, Dioxanes pharmacology, Disease Models, Animal, Female, Humans, Liver Cirrhosis physiopathology, Mice, Thiazoles pharmacology, Adrenergic alpha-2 Receptor Antagonists therapeutic use, Dioxanes therapeutic use, Liver Cirrhosis drug therapy, Receptors, Adrenergic, alpha-2 genetics, Thiazoles therapeutic use
- Abstract
The noradrenergic system is proposed to play a prominent role in the pathogenesis of liver fibrosis. While α1- and β-adrenergic receptors (ARs) are suggested to be involved in a multitude of profibrogenic actions, little is known about α2-AR-mediated effects and their expression pattern during liver fibrosis and cirrhosis. We explored the expression of α2-AR in two models of experimental liver fibrosis. We further evaluated the capacity of the α2-AR blocker mesedin to deactivate hepatic stellate cells (HSCs) and to increase the permeability of human liver sinusoidal endothelial cells (hLSECs). The mRNA of α2a-, α2b-, and α2c-AR subtypes was uniformly upregulated in carbon tetrachloride-treated mice vs the controls, while in bile duct-ligated mice, only α2b-AR increased in response to liver injury. In murine HSCs, mesedin led to a decrease in α-smooth muscle actin, transforming growth factor-β and α2a-AR expression, which was indicated by RT-qPCR, immunocytochemistry, and Western blot analyses. In a hLSEC line, an increased expression of endothelial nitric oxide synthase was detected along with downregulated transforming growth factor-β. In conclusion, we suggest that the α2-AR blockade alleviates the activation of HSCs and may increase the permeability of liver sinusoids during liver injury.
- Published
- 2020
- Full Text
- View/download PDF
27. Antifibrotic Effects of Amyloid-Beta and Its Loss in Cirrhotic Liver.
- Author
-
Buniatian GH, Weiskirchen R, Weiss TS, Schwinghammer U, Fritz M, Seferyan T, Proksch B, Glaser M, Lourhmati A, Buadze M, Borkham-Kamphorst E, Gaunitz F, Gleiter CH, Lang T, Schaeffeler E, Tremmel R, Cynis H, Frey WH 2nd, Gebhardt R, Friedman SL, Mikulits W, Schwab M, and Danielyan L
- Subjects
- Amyloid beta-Peptides pharmacology, Animals, Disease Models, Animal, Humans, Liver Cirrhosis physiopathology, Male, Mice, Mice, Transgenic, Middle Aged, Peptide Fragments pharmacology, Rats, Rats, Sprague-Dawley, Amyloid beta-Peptides therapeutic use, Fibrosis drug therapy, Gene Expression genetics, Liver Cirrhosis therapy, Peptide Fragments therapeutic use
- Abstract
The function and regulation of amyloid-beta (Aβ) in healthy and diseased liver remains unexplored. Because Aβ reduces the integrity of the blood-brain barrier we have examined its potential role in regulating the sinusoidal permeability of normal and cirrhotic liver. Aβ and key proteins that generate (beta-secretase 1 and presenilin-1) and degrade it (neprilysin and myelin basic protein) were decreased in human cirrhotic liver. In culture, activated hepatic stellate cells (HSC) internalized Aβ more efficiently than astrocytes and HSC degraded Aβ leading to suppressed expression of α-smooth muscle actin (α-SMA), collagen 1 and transforming growth factor β (TGFβ). Aβ also upregulated sinusoidal permeability marker endothelial NO synthase (eNOS) and decreased TGFβ in cultured human liver sinusoidal endothelial cells (hLSEC). Liver Aβ levels also correlate with the expression of eNOS in transgenic Alzheimer's disease mice and in human and rodent cirrhosis/fibrosis. These findings suggest a previously unexplored role of Aβ in the maintenance of liver sinusoidal permeability and in protection against cirrhosis/fibrosis via attenuation of HSC activation., Competing Interests: The authors declare no conflict of interest.
- Published
- 2020
- Full Text
- View/download PDF
28. Intranasal Losartan Decreases Perivascular Beta Amyloid, Inflammation, and the Decline of Neurogenesis in Hypertensive Rats.
- Author
-
Drews HJ, Yenkoyan K, Lourhmati A, Buadze M, Kabisch D, Verleysdonk S, Petschak S, Beer-Hammer S, Davtyan T, Frey WH 2nd, Gleiter CH, Schwab M, and Danielyan L
- Subjects
- Administration, Intranasal, Animals, Dose-Response Relationship, Drug, Losartan administration & dosage, Male, Rats, Rats, Inbred SHR, Rats, Sprague-Dawley, Stroke etiology, Amyloid beta-Peptides metabolism, Angiotensin II Type 1 Receptor Blockers therapeutic use, Glymphatic System chemistry, Hypertension complications, Inflammation drug therapy, Losartan therapeutic use, Neurogenesis drug effects, Stroke prevention & control
- Abstract
The contribution of the local angiotensin receptor system to neuroinflammation, impaired neurogenesis, and amyloid beta (Aβ) accumulation in Alzheimer's disease (AD) and in hypertension is consistent with the remarkable neuroprotection provided by angiotensin receptor blockers (ARBs) independent of their blood pressure-lowering effect. Considering the causal relationship between hypertension and AD and that targeting cerebrovascular pathology with ARBs does not necessarily require their systemic effects, we tested intranasal losartan in the rat model of chronic hypertension (spontaneously hypertensive stroke-prone rats, SHRSP). Intranasal losartan at a subdepressor dose decreased mortality, neuroinflammation, and perivascular content of Aβ by enhancing key players in its metabolism and clearance, including insulin-degrading enzyme, neprilysin, and transthyretin. Furthermore, this treatment improved neurologic deficits and increased brain IL-10 concentration, hippocampal cell survival, neurogenesis, and choroid plexus cell proliferation in SHRSP. Losartan (1 μM) also reduced LDH release from cultured astroglial cells in response to toxic glutamate concentrations. This effect was completely blunted by IL-10 antibodies. These findings suggest that intranasal ARB treatment is a neuroprotective, neurogenesis-inducing, and Aβ-decreasing strategy for the treatment of hypertensive stroke and cerebral amyloid angiopathy acting at least partly through the IL-10 pathway.
- Published
- 2019
- Full Text
- View/download PDF
29. Intranasal Administration of Mesenchymal Stem Cells Ameliorates the Abnormal Dopamine Transmission System and Inflammatory Reaction in the R6/2 Mouse Model of Huntington Disease.
- Author
-
Yu-Taeger L, Stricker-Shaver J, Arnold K, Bambynek-Dziuk P, Novati A, Singer E, Lourhmati A, Fabian C, Magg J, Riess O, Schwab M, Stolzing A, Danielyan L, and Nguyen HHP
- Subjects
- Administration, Intranasal, Animals, Brain pathology, Brain physiopathology, Cell Tracking, Circadian Rhythm, Disease Models, Animal, Dopamine and cAMP-Regulated Phosphoprotein 32 metabolism, Gene Expression Regulation, Humans, Huntington Disease genetics, Inflammation genetics, Male, Mice, Inbred C57BL, Mice, Transgenic, Microglia metabolism, Microglia pathology, Motor Activity, Nerve Growth Factors metabolism, Sleep, Survival Analysis, Tyrosine 3-Monooxygenase metabolism, Dopamine metabolism, Huntington Disease physiopathology, Huntington Disease therapy, Inflammation pathology, Mesenchymal Stem Cell Transplantation, Mesenchymal Stem Cells cytology, Synaptic Transmission
- Abstract
Intrastriatal administration of mesenchymal stem cells (MSCs) has shown beneficial effects in rodent models of Huntington disease (HD). However, the invasive nature of surgical procedure and its potential to trigger the host immune response may limit its clinical use. Hence, we sought to evaluate the non-invasive intranasal administration (INA) of MSC delivery as an effective alternative route in HD. GFP-expressing MSCs derived from bone marrow were intranasally administered to 4-week-old R6/2 HD transgenic mice. MSCs were detected in the olfactory bulb, midbrain and striatum five days post-delivery. Compared to phosphate-buffered saline (PBS)-treated littermates, MSC-treated R6/2 mice showed an increased survival rate and attenuated circadian activity disruption assessed by locomotor activity. MSCs increased the protein expression of DARPP-32 and tyrosine hydroxylase (TH) and downregulated gene expression of inflammatory modulators in the brain 7.5 weeks after INA. While vehicle treated R6/2 mice displayed decreased Iba1 expression and altered microglial morphology in comparison to the wild type littermates, MSCs restored both, Iba1 level and the thickness of microglial processes in the striatum of R6/2 mice. Our results demonstrate significantly ameliorated phenotypes of R6/2 mice after MSCs administration via INA, suggesting this method as an effective delivering route of cells to the brain for HD therapy.
- Published
- 2019
- Full Text
- View/download PDF
30. Neuroprotective, Neurogenic, and Amyloid Beta Reducing Effect of a Novel Alpha 2-Adrenoblocker, Mesedin, on Astroglia and Neuronal Progenitors upon Hypoxia and Glutamate Exposure.
- Author
-
Melkonyan MM, Hunanyan L, Lourhmati A, Layer N, Beer-Hammer S, Yenkoyan K, Schwab M, and Danielyan L
- Subjects
- Adrenergic alpha-2 Receptor Antagonists chemistry, Adrenergic alpha-2 Receptor Antagonists therapeutic use, Alzheimer Disease drug therapy, Animals, Astrocytes cytology, Biomarkers, Pharmacological analysis, Cell Survival drug effects, Dioxanes chemistry, Glutamic Acid metabolism, Hypoxia metabolism, Mice, Mice, Inbred C57BL, Mice, Transgenic, Neurons cytology, Neuroprotective Agents chemistry, Neuroprotective Agents therapeutic use, Primary Cell Culture, Thiazoles chemistry, Adrenergic alpha-2 Receptor Antagonists pharmacology, Amyloid beta-Peptides antagonists & inhibitors, Astrocytes drug effects, Dioxanes pharmacology, Dioxanes therapeutic use, Neurogenesis drug effects, Neurons drug effects, Neuroprotective Agents pharmacology, Thiazoles pharmacology, Thiazoles therapeutic use
- Abstract
Locus coeruleus-noradrenergic system dysfunction is known to contribute to the progression of Alzheimer's disease (AD). Besides a variety of reports showing the involvement of norepinephrine and its receptor systems in cognition, amyloid β (Aβ) metabolism, neuroinflammation, and neurogenesis, little is known about the contribution of the specific receptors to these actions. Here, we investigated the neurogenic and neuroprotective properties of a new α2 adrenoblocker, mesedin, in astroglial primary cultures (APC) from C57BL/6 and 3×Tg-AD mice. Our results demonstrate that mesedin rescues neuronal precursors and young neurons, and reduces the lactate dehydrogenase (LDH) release from astroglia under hypoxic and normoxic conditions. Mesedin also increased choline acetyltransferase, postsynaptic density marker 95 (PSD95), and Aβ-degrading enzyme neprilysin in the wild type APC, while in the 3×Tg-AD APC exposed to glutamate, it decreased the intracellular content of Aβ and enhanced the survival of synaptophysin-positive astroglia and neurons. These effects in APC can at least partially be attributed to the mesedin's ability of increasing the expression of Interleukine(IL)-10, which is a potent anti-inflammatory, neuroprotective neurogenic, and Aβ metabolism enhancing factor. In summary, our data identify the neurogenic, neuroprotective, and anti-amyloidogenic action of mesedin in APC. Further in vivo studies are needed to estimate the therapeutic value of mesedin for AD., Competing Interests: The authors declare no conflict of interest.
- Published
- 2017
- Full Text
- View/download PDF
31. Peculiarities of situational and personal anxiety degree in the schoolchildren with ENT chronic diseases.
- Author
-
Mardiyan M, Mkrtchyan S, Shukuryan A, Chopikyan A, Dunamalyan R, and Danielyan L
- Subjects
- Adolescent, Case-Control Studies, Child, Chronic Disease psychology, Cross-Sectional Studies, Female, Humans, Male, Parents psychology, Sex Factors, Surveys and Questionnaires, Anxiety psychology, Otorhinolaryngologic Diseases psychology, Quality of Life, Social Adjustment, Stress, Psychological psychology
- Abstract
Background: A number of the QL researches in case of different pathologies are being increased during the last decade. The existing traditional research methods provide mostly arbitrary data on the disease and its treatment, which are not sufficient for the schoolchildren overall psychological and social adaptation and wellness evaluation., Methods: The research object became schoolchildren of 3 randomly selected schools in Yerevan. 443 monitoring units formed the selection population. The degree of situational and personal anxiety was evaluated with the help of Spielberger's and Gerbachevski's tests., Results: According to our research data the anxiety degree was 29,2 ± 2,3 points among the girls and 12,5 ± 1,6 points among the boys, respectively. The individual anxiety level was especially high: it made up 44,5 ± 0,8 points, and that of the situational anxiety made up 37,2 ± 0,5 points (p < 0,05). According to Gerbachovski's test in the group of schoolchildren with ENT pathology those with a high level of demands made up 53,5 ± 3,2%, with a medium level of demands - 32,4 ± 3,0% and with a low level of demands -14,1 ± 2,2%. A number of the practically healthy schoolchildren with a low level of demands made up 50,3%, and with a high level - 30,7%., Conclusion: According to the investigation data those children who suffer from the ENT chronic diseases usually avoided communication, were sluggish and shy. According to the results of the research, the socio-psychological and adaptation abilities of children with the ENT chronic diseases were lower than those of the practically healthy (without ENT pathologies) coevals. This fact urges to improve the prophylactic measures provision in the mentioned pathologies aspect.
- Published
- 2017
- Full Text
- View/download PDF
32. Interplay between endothelin and erythropoietin in astroglia: the role in protection against hypoxia.
- Author
-
Schäfer R, Mueller L, Buecheler R, Proksch B, Schwab M, Gleiter CH, and Danielyan L
- Subjects
- Animals, Astrocytes cytology, Astrocytes drug effects, Astrocytes metabolism, Cells, Cultured, Erythropoietin genetics, Humans, Peptides, Cyclic pharmacology, RNA, Messenger metabolism, Rats, Rats, Wistar, Receptor, Endothelin A agonists, Receptor, Endothelin A metabolism, Receptors, Erythropoietin metabolism, Up-Regulation drug effects, Cell Hypoxia, Endothelin-1 metabolism, Erythropoietin metabolism
- Abstract
We show that, under in vitro conditions, the vulnerability of astroglia to hypoxia is reflected by alterations in endothelin (ET)-1 release and capacity of erythropoietin (EPO) to regulate ET-1 levels. Exposure of cells to 24 h hypoxia did not induce changes in ET-1 release, while 48-72 h hypoxia resulted in increase of ET-1 release from astrocytes that could be abolished by EPO. The endothelin receptor type A (ETA) antagonist BQ123 increased extracellular levels of ET-1 in human fetal astroglial cell line (SV-FHAS). The survival and proliferation of rat primary astrocytes, neural precursors, and neurons upon hypoxic conditions were increased upon administration of BQ123. Hypoxic injury and aging affected the interaction between the EPO and ET systems. Under hypoxia EPO decreased ET-1 release from astrocytes, while ETA receptor blockade enhanced the expression of EPO mRNA and EPO receptor in culture-aged rat astroglia. The blockade of ETA receptor can increase the availability of ET-1 to the ETB receptor and can potentiate the neuroprotective effects of EPO. Thus, the new therapeutic use of combined administration of EPO and ETA receptor antagonists during hypoxia-associated neurodegenerative disorders of the central nervous system (CNS) can be suggested.
- Published
- 2014
- Full Text
- View/download PDF
33. Intranasal delivery of bone marrow-derived mesenchymal stem cells, macrophages, and microglia to the brain in mouse models of Alzheimer's and Parkinson's disease.
- Author
-
Danielyan L, Beer-Hammer S, Stolzing A, Schäfer R, Siegel G, Fabian C, Kahle P, Biedermann T, Lourhmati A, Buadze M, Novakovic A, Proksch B, Gleiter CH, Frey WH, and Schwab M
- Subjects
- Administration, Intranasal, Animals, Biomarkers metabolism, Bone Marrow Cells cytology, Cell Differentiation, Cell Lineage, Disease Models, Animal, Female, Flow Cytometry, Green Fluorescent Proteins metabolism, Male, Mice, Mice, Inbred C57BL, Mice, Transgenic, Alzheimer Disease therapy, Brain pathology, Macrophages transplantation, Mesenchymal Stem Cell Transplantation, Mesenchymal Stem Cells cytology, Microglia transplantation, Parkinson Disease therapy
- Abstract
In view of the rapid preclinical development of cell-based therapies for neurodegenerative disorders, traumatic brain injury, and tumors, the safe and efficient delivery and targeting of therapeutic cells to the central nervous system is critical for maintaining therapeutic efficacy and safety in the respective disease models. Our previous data demonstrated therapeutically efficacious and targeted delivery of mesenchymal stem cells (MSCs) to the brain in the rat 6-hydroxydopamine model of Parkinson's disease (PD). The present study examined delivery of bone marrow-derived MSCs, macrophages, and microglia to the brain in a transgenic model of PD [(Thy1)-h[A30P] αS] and an APP/PS1 model of Alzheimer's disease (AD) via intranasal application (INA). INA of microglia in naive BL/6 mice led to targeted and effective delivery of cells to the brain. Quantitative PCR analysis of eGFP DNA showed that the brain contained the highest amount of eGFP-microglia (up to 2.1 × 10(4)) after INA of 1 × 10(6) cells, while the total amount of cells detected in peripheral organs did not exceed 3.4 × 10(3). Seven days after INA, MSCs expressing eGFP were detected in the olfactory bulb (OB), cortex, amygdala, striatum, hippocampus, cerebellum, and brainstem of (Thy1)-h[A30P] αS transgenic mice, showing predominant distribution within the OB and brainstem. INA of eGFP-expressing macrophages in 13-month-old APP/PS1 mice led to delivery of cells to the OB, hippocampus, cortex, and cerebellum. Both MSCs and macrophages contained Iba-1-positive population of small microglia-like cells and Iba-1-negative large rounded cells showing either intracellular amyloid β (macrophages in APP/PS1 model) or α-synuclein [MSCs in (Thy1)-h[A30P] αS model] immunoreactivity. Here, we show, for the first time, intranasal delivery of cells to the brain of transgenic PD and AD mouse models. Additional work is needed to determine the optimal dosage (single treatment regimen or repeated administrations) to achieve functional improvement in these mouse models with intranasal microglia/macrophages and MSCs. This manuscript is published as part of the International Association of Neurorestoratology (IANR) special issue of Cell Transplantation.
- Published
- 2014
- Full Text
- View/download PDF
34. Age-dependent astroglial vulnerability to hypoxia and glutamate: the role for erythropoietin.
- Author
-
Lourhmati A, Buniatian GH, Paul C, Verleysdonk S, Buecheler R, Buadze M, Proksch B, Schwab M, Gleiter CH, and Danielyan L
- Subjects
- Amino Acid Transport System X-AG genetics, Amino Acid Transport System X-AG metabolism, Animals, Astrocytes drug effects, Brain metabolism, Cell Hypoxia, Cell Proliferation drug effects, Cell Survival drug effects, Cell Survival genetics, Cellular Senescence, Enzyme Activation drug effects, Erythropoietin genetics, Erythropoietin pharmacology, Extracellular Space metabolism, Gene Expression Regulation drug effects, Glutamate-Ammonia Ligase genetics, Glutamate-Ammonia Ligase metabolism, Glutamic Acid drug effects, Male, Rats, Receptors, Erythropoietin genetics, Receptors, Erythropoietin metabolism, Astrocytes metabolism, Erythropoietin metabolism, Glutamic Acid metabolism
- Abstract
Extracellular accumulation of toxic concentrations of glutamate (Glu) is a hallmark of many neurodegenerative diseases, often accompanied by hypoxia and impaired metabolism of this neuromediator. To address the question whether the multifunctional neuroprotective action of erythropoietin (EPO) extends to the regulation of extracellular Glu-level and is age-related, young and culture-aged rat astroglial primary cells (APC) were simultaneously treated with 1mM Glu and/or human recombinant EPO under normoxic and hypoxic conditions (NC and HC). EPO increased the Glu uptake by astrocytes under both NC and especially upon HC in culture-aged APC (by 60%). Moreover, treatment with EPO up-regulated the activity of glutamine synthetase (GS), the expression of glutamate-aspartate transporter (GLAST) and the level of EPO mRNA. EPO alleviated the Glu- and hypoxia-induced LDH release from astrocytes. These protective EPO effects were concentration-dependent and they were strongly intensified with age in culture. More than a 4-fold increase in apoptosis and a 2-fold decrease in GS enzyme activity was observed in APC transfected with EPO receptor (EPOR)-siRNA. Our in vivo data show decreased expression of EPO and a strong increase of EPOR in brain homogenates of APP/PS1 mice and their wild type controls during aging. Comparison of APP/PS1 and age-matched WT control mice revealed a stronger expression of EPOR but a weaker one of EPO in the Alzheimer's disease (AD) model mice. Here we show for the first time the direct correlation between the extent of differentiation (age) of astrocytes and the efficacy of EPO in balancing extracellular glutamate clearance and metabolism in an in-vitro model of hypoxia and Glu-induced astroglial injury. The clinical relevance of EPO and EPOR as markers of brain cells vulnerability during aging and neurodegeneration is evidenced by remarkable changes in their expression levels in a transgenic model of AD and their WT controls.
- Published
- 2013
- Full Text
- View/download PDF
35. Intranasal treatment of central nervous system dysfunction in humans.
- Author
-
Chapman CD, Frey WH 2nd, Craft S, Danielyan L, Hallschmid M, Schiöth HB, and Benedict C
- Subjects
- Administration, Intranasal, Animals, Central Nervous System Diseases metabolism, Drug Delivery Systems adverse effects, Humans, Central Nervous System Diseases drug therapy, Drug Delivery Systems methods, Pharmaceutical Preparations administration & dosage
- Abstract
One of the most challenging problems facing modern medicine is how to deliver a given drug to a specific target at the exclusion of other regions. For example, a variety of compounds have beneficial effects within the central nervous system (CNS), but unwanted side effects in the periphery. For such compounds, traditional oral or intravenous drug delivery fails to provide benefit without cost. However, intranasal delivery is emerging as a noninvasive option for delivering drugs to the CNS with minimal peripheral exposure. Additionally, this method facilitates the delivery of large and/or charged therapeutics, which fail to effectively cross the blood-brain barrier (BBB). Thus, for a variety of growth factors, hormones, neuropeptides and therapeutics including insulin, oxytocin, orexin, and even stem cells, intranasal delivery is emerging as an efficient method of administration, and represents a promising therapeutic strategy for the treatment of diseases with CNS involvement, such as obesity, Alzheimer's disease, Parkinson's disease, Huntington's disease, depression, anxiety, autism spectrum disorders, seizures, drug addiction, eating disorders, and stroke.
- Published
- 2013
- Full Text
- View/download PDF
36. Nursing practice in a post-Soviet country from the perspectives of Armenian nurses: a qualitative exploratory study.
- Author
-
Poghosyan L, Poghosyan H, Berlin K, Truzyan N, Danielyan L, and Khourshudyan K
- Subjects
- Adult, Armenia, Female, Focus Groups, Health Care Reform, Humans, Male, Middle Aged, Qualitative Research, Nurses psychology, Nursing
- Abstract
Aims and Objectives: The purpose of this qualitative descriptive study was to explore the views of head and staff nurses about nursing practice in the hospitals of Armenia., Background: Armenia inherited its nursing frameworks from the Soviet Union. After the Soviet collapse, many changes took place to reform nursing. However, to date little has been systematically documented about nursing practice in Armenia., Design: Qualitative descriptive design was implemented., Methods: Three major hospitals in Yerevan, the capital city of Armenia, participated in the study. Purposeful sampling was used. Forty-three nurses participated, 29 staff and fourteen head nurses. Data were collected through five focus groups comprised of seven to ten participants. A focus group guide was developed. The researcher facilitated the discussions in Armenian, which were audio taped. The research assistant took notes. Data were transcribed and translated into English, imported into atlas.ti 6.1 qualitative software, and analysed by three authors., Results: Five themes were extracted. Lack of role clarity theme was identified from the head nurse data. The practice environment theme was identified from the staff nurse data. Nursing education, value, respect and appreciation of nursing, and becoming a nurse were common themes identified from both head and staff nurse data. Head nurses lack autonomy, do not have clear roles and are burdened with documentation. Staff nurses practice in challenging work environments with inadequate staffing and demanding workloads. All nurses reported the need to improve nursing education., Conclusions: This is the first study conducted in Armenia exploring nursing practice in the hospitals from the nurses' perspectives. Nurses face challenges that may impact their wellbeing and patient care., Relevance to Clinical Practice: Understanding challenges nursing practice faces in the hospitals in Armenia will help administrators and care providers to take actions to improve nursing practice and subsequently patient care., (© 2012 Blackwell Publishing Ltd.)
- Published
- 2012
- Full Text
- View/download PDF
37. Expression of blood group genes by mesenchymal stem cells.
- Author
-
Schäfer R, Schnaidt M, Klaffschenkel RA, Siegel G, Schüle M, Rädlein MA, Hermanutz-Klein U, Ayturan M, Buadze M, Gassner C, Danielyan L, Kluba T, Northoff H, and Flegel WA
- Subjects
- ABO Blood-Group System metabolism, Blood Group Antigens genetics, Cell Differentiation genetics, Cells, Cultured, Duffy Blood-Group System biosynthesis, Duffy Blood-Group System genetics, Erythrocytes metabolism, Gangliosides metabolism, Humans, Immunophenotyping, Membrane Transport Proteins biosynthesis, Membrane Transport Proteins genetics, Mesenchymal Stem Cells cytology, RNA, Messenger genetics, Receptors, Cell Surface biosynthesis, Receptors, Cell Surface genetics, Transcription, Genetic, Urea Transporters, Blood Group Antigens metabolism, Mesenchymal Stem Cells metabolism
- Abstract
Incompatible blood group antigens are highly immunogenic and can cause graft rejections. Focusing on distinct carbohydrate- and protein-based membrane structures, defined by blood group antigens, we investigated human bone marrow-derived mesenchymal stem cells (MSCs) cultured in human serum. The presence of H (CD173), ABO, RhD, RhCE, RhAG, Kell, urea transporter type B (SLC14A1, previously known as JK), and Duffy antigen receptor of chemokines (DARC) was evaluated at the levels of genome, transcriptome and antigen. Fucosyltransferase-1 (FUT1), RHCE, KEL, SLC14A1 (JK) and DARC mRNA were transcribed in MSCs. FUT1 mRNA transcription was lost during differentiation. The mRNA transcription of SLC14A1 (JK) decreased during chondrogenic differentiation, while that of DARC increased during adipogenic differentiation. All MSCs synthesized SLC14A1 (JK) but no DARC protein. However, none of the protein antigens tested occurred on the surface, indicating a lack of associated protein function in the membrane. As A and B antigens are neither expressed nor adsorbed, concerns of ABO compatibility with human serum supplements during culture are alleviated. The H antigen expression by GD2dim+ MSCs identified two distinct MSC subpopulations and enabled their isolation. We hypothesize that GD2(dim+) H(+) MSCs retain a better 'stemness'. Because immunogenic blood group antigens are lacking, they cannot affect MSC engraftment in vivo, which is promising for clinical applications., (Published 2011. This article is a US Government work and is in the public domain in the USA.)
- Published
- 2011
- Full Text
- View/download PDF
38. Therapeutic efficacy of intranasally delivered mesenchymal stem cells in a rat model of Parkinson disease.
- Author
-
Danielyan L, Schäfer R, von Ameln-Mayerhofer A, Bernhard F, Verleysdonk S, Buadze M, Lourhmati A, Klopfer T, Schaumann F, Schmid B, Koehle C, Proksch B, Weissert R, Reichardt HM, van den Brandt J, Buniatian GH, Schwab M, Gleiter CH, and Frey WH 2nd
- Subjects
- Administration, Intranasal, Animals, Blotting, Western, Cell Proliferation, Disease Models, Animal, HEK293 Cells, HeLa Cells, Humans, Interleukins metabolism, Male, Neostriatum enzymology, Neostriatum pathology, Oxidopamine, Rats, Rats, Sprague-Dawley, Substantia Nigra enzymology, Substantia Nigra pathology, Tyrosine 3-Monooxygenase metabolism, Mesenchymal Stem Cell Transplantation, Mesenchymal Stem Cells cytology, Parkinson Disease therapy
- Abstract
Safe and effective cell delivery remains one of the main challenges in cell-based therapy of neurodegenerative disorders. Graft survival, sufficient enrichment of therapeutic cells in the brain, and avoidance of their distribution throughout the peripheral organs are greatly influenced by the method of delivery. Here we demonstrate for the first time noninvasive intranasal (IN) delivery of mesenchymal stem cells (MSCs) to the brains of unilaterally 6-hydroxydopamine (6-OHDA)-lesioned rats. IN application (INA) of MSCs resulted in the appearance of cells in the olfactory bulb, cortex, hippocampus, striatum, cerebellum, brainstem, and spinal cord. Out of 1 × 10⁶ MSCs applied intranasally, 24% survived for at least 4.5 months in the brains of 6-OHDA rats as assessed by quantification of enhanced green fluorescent protein (EGFP) DNA. Quantification of proliferating cell nuclear antigen-positive EGFP-MSCs showed that 3% of applied MSCs were proliferative 4.5 months after application. INA of MSCs increased the tyrosine hydroxylase level in the lesioned ipsilateral striatum and substantia nigra, and completely eliminated the 6-OHDA-induced increase in terminal deoxynucleotidyl transferase (TdT)-mediated 2'-deoxyuridine, 5'-triphosphate (dUTP)-biotin nick end labeling (TUNEL) staining of these areas. INA of EGFP-labeled MSCs prevented any decrease in the dopamine level in the lesioned hemisphere, whereas the lesioned side of the control animals revealed significantly lower levels of dopamine 4.5 months after 6-OHDA treatment. Behavioral analyses revealed significant and substantial improvement of motor function of the Parkinsonian forepaw to up to 68% of the normal value 40-110 days after INA of 1 × 10⁶ cells. MSC-INA decreased the concentrations of inflammatory cytokines-interleukin-1β (IL-1β), IL-2, -6, -12, tumor necrosis factor (TNF), interferon-γ (IFN-γ, and granulocyte-macrophage colony-stimulating factor (GM-CSF)-in the lesioned side to their levels in the intact hemisphere. IN administration provides a highly promising noninvasive alternative to the traumatic surgical procedure of transplantation and allows targeted delivery of cells to the brain with the option of chronic application.
- Published
- 2011
- Full Text
- View/download PDF
39. Protective effects of intranasal losartan in the APP/PS1 transgenic mouse model of Alzheimer disease.
- Author
-
Danielyan L, Klein R, Hanson LR, Buadze M, Schwab M, Gleiter CH, and Frey WH
- Subjects
- Administration, Intranasal, Alzheimer Disease genetics, Alzheimer Disease pathology, Alzheimer Disease physiopathology, Amyloid beta-Protein Precursor genetics, Angiotensin II Type 1 Receptor Blockers administration & dosage, Angiotensin II Type 1 Receptor Blockers pharmacology, Animals, Blood Pressure drug effects, Drug Evaluation, Preclinical, Female, Losartan pharmacology, Mice, Neurons pathology, Neurons physiology, Plaque, Amyloid drug effects, Plaque, Amyloid metabolism, Plaque, Amyloid pathology, Presenilin-1 genetics, Alzheimer Disease drug therapy, Cytoprotection drug effects, Disease Models, Animal, Losartan administration & dosage, Mice, Transgenic, Neurons drug effects
- Abstract
The local renin-angiotensin system (RAS) in the brain is a multitasking system controlling a plethora of essential functions such as neurogenic hypertension, baroreflexes, and sympathetic activity. Aside from its vasoactive actions, brain angiotensin II (AT-II) has also been implicated in the pathogenesis of cognitive decline, and beneficial effects of angiotensin receptor blockers (ARBs) in Alzheimer (AD) and Parkinson diseases (PD) are suggested. However, the use of ARBs at antihypertensive dosages would lead to unwanted hypotensive reactions in AD patients. Here we treated the APP/PS1 transgenic mouse model of AD with the ARB losartan (10 mg/kg body weight) to determine whether blockade of the AT-II receptor subtype 1 (AT1-R) with intranasal losartan, using at a dosage far below its systemic antihypertensive dose, could maintain its neuroprotective effects independent of its systemic vasoactive action. Intranasal losartan treatment (10 mg/kg every other day for 2 months) of APP/PS1 mice decreased amyloid beta (Abeta) plaques 3.7-fold. Blood serum levels of interleukin-12 (IL-12)p40/p70, IL-1beta, and granulocyte-macrophage colony-stimulating factor (GM-CSF) were increased in the vehicle-treated APP/PS1 mice. Intranasal losartan not only decreased IL-12p40/p70, IL-1beta, and GM-CSF, but also increased IL-10, which suppresses inflammation. Furthermore, losartan markedly increased tyrosine hydroxylase expression in the striatum and locus coeruleus. In conclusion, losartan exerts direct neuroprotective effects via its Abeta-reducing and antiinflammatory effects in the central nervous system (CNS). Therefore, intranasal losartan and potentially other ARBs, at concentrations below their threshold for altering systemic blood pressure, offer a new approach for the treatment of AD.
- Published
- 2010
- Full Text
- View/download PDF
40. Intranasal delivery of cells to the brain.
- Author
-
Danielyan L, Schäfer R, von Ameln-Mayerhofer A, Buadze M, Geisler J, Klopfer T, Burkhardt U, Proksch B, Verleysdonk S, Ayturan M, Buniatian GH, Gleiter CH, and Frey WH 2nd
- Subjects
- Animals, Cell Line, Female, Humans, Immunohistochemistry, In Vitro Techniques, Mesenchymal Stem Cells cytology, Mice, Mice, Inbred C57BL, Olfactory Pathways, Rats, Rats, Wistar, Administration, Intranasal, Brain cytology, Brain metabolism, Stem Cell Transplantation methods
- Abstract
The safety and efficacy of cell-based therapies for neurodegenerative diseases depends on the mode of cell administration. We hypothesized that intranasally administered cells could bypass the blood-brain barrier by migrating from the nasal mucosa through the cribriform plate along the olfactory neural pathway into the brain and cerebrospinal fluid (CSF). This would minimize or eliminate the distribution of cellular grafts to peripheral organs and will help to dispense with neurosurgical cell implantation. Here we demonstrate transnasal delivery of cells to the brain following intranasal application of fluorescently labeled rat mesenchymal stem cells (MSC) or human glioma cells to naive mice and rats. After cells crossed the cribriform plate, two migration routes were identified: (1) migration into the olfactory bulb and to other parts of the brain; (2) entry into the CSF with movement along the surface of the cortex followed by entrance into the brain parenchyma. The delivery of cells was enhanced by hyaluronidase treatment applied intranasally 30 min prior to the application of cells. Intranasal delivery provides a new non-invasive method for cell delivery to the CNS.
- Published
- 2009
- Full Text
- View/download PDF
41. Keratinocytes as depository of ammonium-inducible glutamine synthetase: age- and anatomy-dependent distribution in human and rat skin.
- Author
-
Danielyan L, Zellmer S, Sickinger S, Tolstonog GV, Salvetter J, Lourhmati A, Reissig DD, Gleiter CH, Gebhardt R, and Buniatian GH
- Subjects
- Actins metabolism, Animals, Animals, Newborn, Cell Count, Cells, Cultured, Child, Dexamethasone pharmacology, Enzyme Induction drug effects, Glial Fibrillary Acidic Protein metabolism, Humans, Keratinocytes cytology, Keratinocytes drug effects, Lithium Chloride pharmacology, Male, Metallothionein metabolism, Protein Transport drug effects, Rats, Scalp cytology, Scalp drug effects, Scalp metabolism, Skin cytology, Skin drug effects, beta Catenin metabolism, Aging physiology, Glutamate-Ammonia Ligase biosynthesis, Keratinocytes enzymology, Quaternary Ammonium Compounds pharmacology, Skin anatomy & histology, Skin enzymology
- Abstract
In inner organs, glutamine contributes to proliferation, detoxification and establishment of a mechanical barrier, i.e., functions essential for skin, as well. However, the age-dependent and regional peculiarities of distribution of glutamine synthetase (GS), an enzyme responsible for generation of glutamine, and factors regulating its enzymatic activity in mammalian skin remain undisclosed. To explore this, GS localization was investigated using immunohistochemistry and double-labeling of young and adult human and rat skin sections as well as skin cells in culture. In human and rat skin GS was almost completely co-localized with astrocyte-specific proteins (e.g. GFAP). While GS staining was pronounced in all layers of the epidermis of young human skin, staining was reduced and more differentiated among different layers with age. In stratum basale and in stratum spinosum GS was co-localized with the adherens junction component beta-catenin. Inhibition of, glycogen synthase kinase 3beta in cultured keratinocytes and HaCaT cells, however, did not support a direct role of beta-catenin in regulation of GS. Enzymatic and reverse transcriptase polymerase chain reaction studies revealed an unusual mode of regulation of this enzyme in keratinocytes, i.e., GS activity, but not expression, was enhanced about 8-10 fold when the cells were exposed to ammonium ions. Prominent posttranscriptional up-regulation of GS activity in keratinocytes by ammonium ions in conjunction with widespread distribution of GS immunoreactivity throughout the epidermis allows considering the skin as a large reservoir of latent GS. Such a depository of glutamine-generating enzyme seems essential for continuous renewal of epidermal permeability barrier and during pathological processes accompanied by hyperammonemia.
- Published
- 2009
- Full Text
- View/download PDF
42. Angiotensin receptor type 1 blockade in astroglia decreases hypoxia-induced cell damage and TNF alpha release.
- Author
-
Danielyan L, Lourhmati A, Verleysdonk S, Kabisch D, Proksch B, Thiess U, Umbreen S, Schmidt B, and Gleiter CH
- Subjects
- Animals, Cells, Cultured, Imidazoles pharmacology, Rats, Rats, Wistar, Receptor, Angiotensin, Type 1 biosynthesis, Receptor, Angiotensin, Type 2 biosynthesis, Tetrazoles pharmacology, Astrocytes drug effects, Astrocytes metabolism, Cell Hypoxia physiology, Losartan pharmacology, Receptor, Angiotensin, Type 1 drug effects, Tumor Necrosis Factor-alpha metabolism
- Abstract
The present study investigated the role of angiotensin receptors (AT-R) in the survival and inflammatory response of astroglia upon hypoxic injury. Exposure of rat astroglial primary cultures (APC) to hypoxic conditions (HC) led to decreased viability of the cells and to a 3.5-fold increase in TNF-alpha release. AT-R type1 (AT1-R) antagonist losartan and its metabolite EXP3174 decrease the LDH release (by 36 +/- 9%; 45 +/- 6%) from APC under HC. Losartan diminished TNF-alpha release (by 40 +/- 15%) and the number of TUNEL-cells by 204 +/- 38% under HC, alone and together with angiotensin II (ATII), while EXP3174 was dependent on ATII for its effect on TNF-alpha. The AT2-R antagonist, PD123.319, did not influence the release of LDH and TNF-alpha under normoxic (NC) and HC. These data suggest that AT1-R may decrease the susceptibility of astrocytes to hypoxic injury and their propensity to release TNF-alpha. AT1-R antagonists may therefore be of therapeutic value during hypoxia-associated neurodegeneration.
- Published
- 2007
- Full Text
- View/download PDF
43. Colocalization of glial fibrillary acidic protein, metallothionein, and MHC II in human, rat, NOD/SCID, and nude mouse skin keratinocytes and fibroblasts.
- Author
-
Danielyan L, Tolstonog G, Traub P, Salvetter J, Gleiter CH, Reisig D, Gebhardt R, and Buniatian GH
- Subjects
- Animals, Epidermis metabolism, Fibroblasts metabolism, Humans, Keratinocytes metabolism, Lung metabolism, Mice, Mice, Inbred BALB C, Mice, Inbred C57BL, Mice, Inbred NOD, Mice, Nude, Mice, SCID, Rats, Fibroblasts cytology, Glial Fibrillary Acidic Protein biosynthesis, Histocompatibility Antigens Class II biosynthesis, Keratinocytes cytology, Metallothionein biosynthesis
- Abstract
The expression of glial fibrillary acidic protein (GFAP) by perivascular cells of many mammalian organs suggests an as yet unknown function of this intermediate filament protein in the maintenance of homeostasis and vascular permeability at the blood-tissue interface. Although a similar situation may exist at the air-tissue interface, the cellular distribution of GFAP in skin tissue has never been demonstrated. To approach this issue, we have employed immunofluorescence and Western blotting techniques to detect GFAP in skin sections of young and adult humans, normal rodents, and two types of mutant mice, as well as in rat lung sections, and in cultured human keratinocytes and fibroblasts. Colocalization with antigens known to be associated with GFAP in other tissues was also tested. Epidermal and hair follicle keratinocytes and dermal fibroblasts showed distinct staining for GFAP as well as colocalization with alpha-actin, metallothionein, and antigens of the class-II major histocompatibility complex (MHC II). GFAP was also identified in rat alveolar fibroblasts which, in common with keratinocytes, form part of the air-tissue interface. GFAP was upregulated together with MHC II in nude mice but was barely detectable in the skin of non-obese diabetic severe combined immunodeficiency mice, suggesting a possible involvement in antigen-presenting functions. The intriguing distribution of a common set of antigens both in certain cells of the integumentary system and at the blood-tissue interfaces of internal organs suggests the involvement of these proteins in universal mechanisms controlling tissue homeostasis and protection.
- Published
- 2007
- Full Text
- View/download PDF
44. Common neuroprotective effects of endothelin receptor a blockade and erythropoietin during hypoxia-associated cell injury. Perspectives of combined treatment.
- Author
-
Danielyan L, Buniatian GH, and Gleiter CH
- Subjects
- Humans, Neovascularization, Physiologic, Endothelin A Receptor Antagonists, Erythropoietin physiology, Hypoxia drug therapy, Neuroprotective Agents therapeutic use, Wounds and Injuries drug therapy
- Published
- 2006
- Full Text
- View/download PDF
45. Similar protective effects of BQ-123 and erythropoietin on survival of neural cells and generation of neurons upon hypoxic injury.
- Author
-
Danielyan L, Mueller L, Proksch B, Kabisch D, Weller M, Wiesinger H, Buniatian GH, and Gleiter CH
- Subjects
- Animals, Animals, Newborn, Brain cytology, Cell Adhesion, Cell Culture Techniques, Cell Line, Cell Survival drug effects, Cells, Cultured, Humans, Immunohistochemistry, Rats, Rats, Wistar, Astrocytes metabolism, Cell Hypoxia drug effects, Erythropoietin pharmacology, Neuroprotective Agents pharmacology, Peptides, Cyclic pharmacology
- Abstract
Our recent study [Danielyan et al., 2005. Eur. J. Cell Biol. 84, 567-579] showed an additive protective effect of endothelin (ET) receptor A (ETA-R) blockade and erythropoietin (EPO) on the survival and rejuvenation of rat astroglial cells exposed to hypoxia. Whether the effects observed with rodent astroglial cells can be reproduced in human astrocytes and whether these effects of ETA-R blockade and EPO on astrocytes are associated with neuronal survival remained open. Therefore, in the present study, the effects of the ETA-R antagonist BQ-123 and EPO on the maintenance of the neuronal population and survival of the human fetal astroglial cell line (SV-FHAS) under normoxic and hypoxic conditions (NC and HC, respectively) were investigated. Rat brain primary cultures exposed to BQ-123 and/or EPO revealed an increase in the number of beta-III tubulin-positive neurons under NC. The hypoxia-caused loss of neurons was abolished by administration of BQ-123 or EPO. Simultaneous application of EPO and BQ-123 led to an additive protective effect on the generation of neurons under NC only. By contrast, BQ-788, the selective ETB-R antagonist, diminished the neuronal population both in NC and HC. Both under NC and HC the number of non-differentiated nestin+/GFAP- neural cells increased upon application of EPO or BQ-123. SV-FHAS responded to BQ-123 or EPO by a decrease in LDH activity in the culture medium under NC (35%) and HC (26% LDH decrease). Concomitant effects of EPO and BQ-123 were illustrated in an additional increase in the survival of human astrocytes (33% under NC and 17% under HC). These data hint at a neuroprotective therapeutic potency of ETA-R blockade, which either alone or in combination with EPO may improve the survival of astroglial and neuronal cells upon hypoxic injury.
- Published
- 2005
- Full Text
- View/download PDF
46. The blockade of endothelin A receptor protects astrocytes against hypoxic injury: common effects of BQ-123 anderythropoietin on the rejuvenation of the astrocyte population.
- Author
-
Danielyan L, Gembizki O, Proksch B, Weinmann M, Morgalla M, Wiesinger H, Buniatian GH, and Gleiter CH
- Subjects
- Animals, Cell Hypoxia drug effects, Cell Survival drug effects, Cells, Cultured, Rats, Rats, Wistar, Receptor, Endothelin A metabolism, Antihypertensive Agents pharmacology, Astrocytes metabolism, Endothelin A Receptor Antagonists, Erythropoietin pharmacology, Peptides, Cyclic pharmacology
- Abstract
In the present study the role of endothelin (ET) and its receptors (ETA-R and ETB-R) in cellular mechanisms underlying the resistance of astroglial cells to low oxygen level and development of hypoxia has been investigated. To define the influences of ET and its receptors on survival and on antigenic as well as morphologic differentiation of rat astroglial cells in normoxic (NC) and hypoxic culture (HC) the selective antagonists of ETA-R (BQ-123) and ETB-R (BQ-788) were used. Treatment of HC with BQ-123 caused an increase in cell number and inhibited the hypoxia-induced apoptosis by 37%. BQ-123 decreased the hypoxia-induced cytotoxicity in HC. These effects of BQ-123 were abolished in cultures simultaneously treated with BQ-123 and BQ-788. Administration of BQ-788 alone decreased the number of living cells in NC, but not in HC. The activity of caspase-3/-7 was not changed by exposure of NC and HC to BQ-788. The protection provided by BQ-123 to astroglial cells against cytotoxicity in NC and HC was similar to that of erythropoietin (EPO), a cytokine with established neuroprotective effects. The functional improvement of astroglial cells and slowing down of their differentiation under exposure to BQ-123, or EPO, or BQ-123 + EPO has been evidenced by an increased number of nestin+/glial fibrillary acidic protein-positive (GFAP+) astrocytes accompanied by decrease of nestin-/GFAP+ cells. The simultaneous treatment with BQ-123 and EPO additionally decreased the activities of caspase-3/-7 (64%) and release of LDH into the medium (94%). The benefits in the functional states of astrocytes obtained by combined treatment of HC with BQ-123 and EPO suggest a new therapeutic strategy in treatment of hypoxic brain injury.
- Published
- 2005
- Full Text
- View/download PDF
47. Characterization of the cAMP binding site of purified S-adenosyl-homocysteine hydrolase from bovine kidney.
- Author
-
Kloor D, Danielyan L, and Osswald H
- Subjects
- Adenosylhomocysteinase, Animals, Binding Sites, Cattle, Hydrolases drug effects, Hypoxanthine metabolism, Theophylline pharmacology, Tritium, Xanthines pharmacology, Cyclic AMP metabolism, Hydrolases metabolism, Kidney enzymology
- Abstract
The enzyme S-adenosyl-homocysteine hydrolase (AdoHcyase) which catalyzes the reversible hydrolysis of AdoHcy to adenosine and homocysteine is an adenosine binding protein. In the present study we examined the characteristics of [(3)H]cAMP binding to purified AdoHcyase from bovine kidney in comparison with the high affinity adenosine binding site of AdoHcyase. AdoHcyase exhibits one [(3)H]cAMP binding site with an affinity of K(d)=23.1+/-1.1nM and a B(max) of 116.6+/-3.8pmol/mg protein. Binding of [(3)H]cAMP obeyed a monophasic reaction with a k(+1) value of 0.035min/M. The dissociation of AdoHcyase-[(3)H]cAMP complex exhibited a time- and temperature-dependent character. After a 240min incubation at 0 degrees only 5-10%, however, at 20 degrees 90% were displaceable. Adenosine and cAMP displace each other with similar affinities of EC(50) 57nM vs. EC(50) 65nM. 2'-Deoxyadenosine, N(6)-methyladenosine, and NECA displace 25nM [(3)H]cAMP and 10nM [(3)H]adenosine with EC(50) values of 94, 90 and 80nM, respectively. All other nucleosides studied, adenine, inosine, adenosine-2',3'-dialdehyde, 2-chloroadenosine, aristeromycin, and adenine nucleotides were only week competitors for [(3)H]cAMP and [(3)H]adenosine. These compounds displace [(3)H]cAMP and [(3)H]adenosine with equal potencies. Our data indicate that the binding site for nanomolar concentrations of cAMP and adenosine at the AdoHcyase appears to be identical. The physiological implications of a cAMP binding site at the AdoHcyase remain to be established.
- Published
- 2002
- Full Text
- View/download PDF
Catalog
Discovery Service for Jio Institute Digital Library
For full access to our library's resources, please sign in.