losartan-potassium has been researched along with Friedreich-Ataxia* in 17 studies
2 review(s) available for losartan-potassium and Friedreich-Ataxia
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Erythropoietin in Friedreich ataxia.
In Friedreich ataxia (FRDA), several candidate substances including erythropoietin (EPO) focus on increase in the amount of frataxin and aim to counteract the consequences of frataxin deficiency. Evidence for recombinant human erythropoietin (rHuEPO) in FRDA is based on in vitro studies using mouse neuronal cell lines, human fibroblasts, cardiomyocytes, and primary lymphocytes from FRDA patients or control subjects which showed a dose-dependent increase of frataxin after incubation with different erythropoietins. The mechanism by which EPO induces frataxin increase remains to be elucidated, but may involve post-transcriptional and/or post-translational modifications of frataxin or alterations in frataxin half-life and metabolism. In vivo data on rHuEPO's ability to increase frataxin in FRDA patients is contradictory as studies on the effect of EPO derivatives in FRDA differ in treatment regimen, sample size, and duration. Open-label studies indicate for sustained frataxin increase, decrease of oxidative stress, and clinical improvement in FRDA patients after administration of rHuEPO. Two randomized controlled studies found acceptable safety and tolerability of EPO derivatives in FRDA. Secondary outcome measures, however, such as frataxin up-regulation and clinical efficacy were not met. This review will focus on (i) pre-clinical work on erythropoietins in FRDA and (ii) clinical studies in FRDA patients exposed to erythropoietins. Topics: Animals; Epoetin Alfa; Erythropoietin; Frataxin; Friedreich Ataxia; Humans; Iron-Binding Proteins; Recombinant Proteins | 2013 |
Pharmacotherapy for Friedreich ataxia.
Friedreich ataxia (FA) is a progressive genetic neurological disorder associated with degeneration of the dorsal columns, spinocerebellar tracts and other regions of the nervous system. The disorder results from mutations in the gene referred to as FXN. Almost all mutations are expansions of an intronic GAA repeat in this gene, which gives rise to decreased transcription of the gene product (called frataxin). Following these discoveries, drug discovery has moved at a rapid pace. Therapeutic trials in the next 5 years are expected to address amelioration of the effects of frataxin deficiency and methods for increasing frataxin expression. These therapies are directed at all levels of biochemical dysfunction in FA. Agents such as idebenone potentially improve mitochondrial function and decrease production of reactive oxygen species. Idebenone is presently in a phase III trial in the US and in Europe, with the primary outcome measure being neurological function. Deferiprone, an atypical iron chelator, may decrease build-up of toxic iron in the mitochondria in patients. It has entered a phase II trial in Europe, Australia and Canada directed toward improvement of neurological abilities. Finally, targeted histone deacetylase (HDAC) inhibitors and erythropoietin increase levels of frataxin when used in vitro, suggesting that they may provide methods for increasing frataxin levels in patients. Erythropoietin has been tested in a small phase II trial in Austria, while HDAC inhibitors are still at a preclinical stage. Symptomatic therapies are also in use for specific symptoms such as spasticity (baclofen). Thus, there is substantial optimism for development of new therapies for FA in the near future, and we suggest that one or several may be available over the next few years. However, continued development of new therapies will require creation of new, more sensitive measures for neurological dysfunction in FA, and clinically relevant measures of cardiac dysfunction. Topics: Animals; Antioxidants; Deferiprone; Enzyme Inhibitors; Erythropoietin; Friedreich Ataxia; Histone Deacetylase Inhibitors; Humans; Iron Chelating Agents; Organophosphorus Compounds; Pyridones; Recombinant Proteins; Ubiquinone | 2009 |
9 trial(s) available for losartan-potassium and Friedreich-Ataxia
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Safety and tolerability of carbamylated erythropoietin in Friedreich's ataxia.
Erythropoietin (EPO) derivatives have been found to increase frataxin levels in Friedreich's ataxia (FRDA) in vitro. This multicenter, double-blind, placebo-controlled, phase II clinical trial aimed to evaluate the safety and tolerability of Lu AA24493 (carbamylated EPO; CEPO).. Thirty-six ambulatory FRDA patients harboring >400 GAA repeats were 2:1 randomly assigned to either CEPO in a fixed dose (325 µg thrice-weekly) or placebo. Safety and tolerability were assessed up to 103 days after baseline. Secondary outcome measures of efficacy (exploration of biomarkers and ataxia ratings) were performed up to 43 days after baseline.. All patients received six doses of study medication. Adverse events were equally distributed between CEPO and placebo. There was no evidence for immunogenicity of CEPO after multiple dosing. Biomarkers, such as frataxin, or measures for oxidative stress and ataxia ratings did not differ between CEPO and placebo.. CEPO was safe and well tolerated in a 2-week treatment phase. Secondary outcome measures remained without apparent difference between CEPO and placebo. Topics: Adult; Biomarkers; Double-Blind Method; Erythropoietin; Female; Frataxin; Friedreich Ataxia; Humans; Iron-Binding Proteins; Male; Treatment Outcome | 2014 |
Triple therapy with darbepoetin alfa, idebenone, and riboflavin in Friedreich's ataxia: an open-label trial.
Minimal objective evidence exists regarding management of Friedreich's ataxia (FRDA). Antioxidant and recombinant human erythropoietin therapies have been considered potential treatments to slow progression of FRDA in a small number of studies. The primary objective of the current study was to test the efficacy, safety, and tolerability of triple therapy-darbepoetin alfa, idebenone, and riboflavin-in FRDA in a clinical pilot study. Patients included in this study were nine females, 16 to 45 years of age (average 28 ± 8), diagnosed with FRDA with confirmed GAA repeat expansion mutations in the FXN gene and a GAA repeat ≥400 on the shorter allele. Patients had a baseline score between 8 and 28.5 (average 20.7 ± 8.3) on the scale for the assessment and rating of ataxia and 94.3 ± 27.2 g/m(2) in left ventricular mass index (LVMI). Patients had been treated with triple therapy with 150 μg darbepoetin alfa every 2 or 3 weeks, 10-20 mg/kg/day idebenone, and 10-15 mg/kg/day riboflavin for 32 ± 19.4 months (range of 8-56 months). Triple therapy was tolerated. Although not statistically significant, improvement of ataxia was observed during the first six 4-month periods of the study. Furthermore, a small decrease in disease progression during the first 2 years of treatment was observed. Long-term statistically nonsignificant improvement of LVMI and stability of the echocardiographic parameters could be considered. Triple therapy may slow disease progression of FRDA. Topics: Adolescent; Adult; Antioxidants; Darbepoetin alfa; Drug Therapy, Combination; Erythropoietin; Female; Friedreich Ataxia; Hematinics; Humans; Male; Middle Aged; Pilot Projects; Riboflavin; Ubiquinone; Young Adult | 2013 |
Bioenergetics of the calf muscle in Friedreich ataxia patients measured by 31P-MRS before and after treatment with recombinant human erythropoietin.
Friedreich ataxia (FRDA) is caused by a GAA repeat expansion in the FXN gene leading to reduced expression of the mitochondrial protein frataxin. Recombinant human erythropoietin (rhuEPO) is suggested to increase frataxin levels, alter mitochondrial function and improve clinical scores in FRDA patients. Aim of the present pilot study was to investigate mitochondrial metabolism of skeletal muscle tissue in FRDA patients and examine effects of rhuEPO administration by phosphorus 31 magnetic resonance spectroscopy (31P MRS). Seven genetically confirmed FRDA patients underwent 31P MRS of the calf muscles using a rest-exercise-recovery protocol before and after receiving 3000 IU of rhuEPO for eight weeks. FRDA patients showed more rapid phosphocreatine (PCr) depletion and increased accumulation of inorganic phosphate (Pi) during incremental exercise as compared to controls. After maximal exhaustive exercise prolonged regeneration of PCR and slowed decline in Pi can be seen in FRDA. PCr regeneration as hallmark of mitochondrial ATP production revealed correlation to activity of complex II/III of the respiratory chain and to demographic values. PCr and Pi kinetics were not influenced by rhuEPO administration. Our results confirm mitochondrial dysfunction and exercise intolerance due to impaired oxidative phosphorylation in skeletal muscle tissue of FRDA patients. MRS did not show improved mitochondrial bioenergetics after eight weeks of rhuEPO exposition in skeletal muscle tissue of FRDA patients.. EU Clinical Trials Register2008-000040-13. Topics: Adult; Demography; Energy Metabolism; Erythropoietin; Exercise; Female; Friedreich Ataxia; Humans; Kinetics; Magnetic Resonance Spectroscopy; Male; Muscle, Skeletal; Phosphates; Phosphocreatine; Phosphorus Isotopes; Recombinant Proteins; Statistics as Topic; Time Factors | 2013 |
Erythropoietin in Friedreich ataxia: no effect on frataxin in a randomized controlled trial.
Friedreich ataxia is a rare disease caused by GAA-trinucleotide-repeat expansions in the frataxin gene, leading to marked reduction of qualitatively normal frataxin protein. Recently, human recombinant erythropoietin was reported to increase frataxin levels in patients with Friedreich ataxia.. We performed a 6-month, randomized placebo-controlled, double-blind, dose-response pilot trial to assess the safety and efficacy of erythropoietin in increasing frataxin levels. Sixteen adult patient with Friedreich ataxia were randomly assigned to erythropoietin (n = 11) or matching placebo (n = 5). All patients continued Idebenone treatment (5 mg/kg/day). Treatment consisted of a 6-month scaling-up phase, in which erythropoietin was administered intravenously at the following doses: 20,000 IU every 3 weeks, 40,000 IU every 3 weeks, and 40,000 IU every 2 weeks.. Erythropoietin treatment was safe and well tolerated, but did not result in any significant hematological, clinical, or biochemical effects in Friedreich ataxia patients. Topics: Adult; Antioxidants; Dose-Response Relationship, Drug; Double-Blind Method; Erythropoietin; Female; Frataxin; Friedreich Ataxia; Humans; Iron-Binding Proteins; Male; Recombinant Proteins; Statistics, Nonparametric; Time Factors; Treatment Outcome; Ubiquinone; Young Adult | 2012 |
Epoetin alfa increases frataxin production in Friedreich's ataxia without affecting hematocrit.
Objective of the study was to test the efficacy, safety, and tolerability of two single doses of Epoetin alfa in patients with Friedreich's ataxia. Ten patients were treated subcutaneously with 600 IU/kg for the first dose, and 3 months later with 1200 IU/kg. Epoetin alfa had no acute effect on frataxin, whereas a delayed and sustained increase in frataxin was evident at 3 months after the first dose (+35%; P < 0.05), and up to 6 months after the second dose (+54%; P < 0.001). The treatment was well tolerated and did not affect hematocrit, cardiac function, and neurological scale. Single high dose of Epoetin alfa can produce a considerably larger and sustained effect when compared with low doses and repeated administration schemes previously adopted. In addition, no hemoglobin increase was observed, and none of our patients required phlebotomy, indicating lack of erythropoietic effect of single high dose of erythropoietin. Topics: Adult; Analysis of Variance; Dose-Response Relationship, Drug; Epoetin Alfa; Erythropoietin; Female; Follow-Up Studies; Frataxin; Friedreich Ataxia; Hematinics; Hematocrit; Humans; Iron; Iron-Binding Proteins; Male; Recombinant Proteins; Time Factors | 2011 |
Effects of erythropoietin on frataxin levels and mitochondrial function in Friedreich ataxia--a dose-response trial.
Friedreich ataxia (FRDA) is an autosomal recessive inherited neurodegenerative disorder leading to reduced expression of the mitochondrial protein frataxin. Previous studies showed frataxin upregulation in FRDA following treatment with recombinant human erythropoietin (rhuEPO). Dose-response interactions between frataxin and rhuEPO have not been studied until to date. We administered escalating rhuEPO single doses (5,000, 10,000 and 30,000 IU) in monthly intervals to five adult FRDA patients. Measurements of frataxin, serum erythropoietin levels, iron metabolism and mitochondrial function were carried out. Clinical outcome was assessed using the "Scale for the assessment and rating of ataxia". We found maximal erythropoietin serum concentrations 24 h after rhuEPO application which is comparable to healthy subjects. Frataxin levels increased significantly over 3 months, while ataxia rating did not reveal clinical improvement. All FRDA patients had considerable ferritin decrease. NADH/NAD ratio, an indicator of mitochondrial function, increased following rhuEPO treatment. In addition to frataxin upregulation in response to continuous low-dose rhuEPO application shown in previous studies, our results indicate for a long-lasting frataxin increase after single high-dose rhuEPO administration. To detect frataxin-derived neuroprotective effects resulting in clinically relevant improvement, well-designed studies with extended time frame are required. Topics: Adult; Dose-Response Relationship, Drug; Drug Administration Schedule; Erythropoietin; Female; Frataxin; Friedreich Ataxia; Humans; Iron-Binding Proteins; Male; Middle Aged; Mitochondria; Pilot Projects; Recombinant Proteins | 2011 |
Correlation of frataxin content in blood and skeletal muscle endorses frataxin as a biomarker in Friedreich ataxia.
Friedreich ataxia is an autosomal recessive disorder caused by mutations in the frataxin gene, leading to reduced levels of the mitochondrial protein frataxin. Assays to quantitatively measure frataxin in peripheral blood have been established. To determine the validity of frataxin as a biomarker for clinical trials, we assessed frataxin in clinically affected tissue.. In 7 patients with Friedreich ataxia, frataxin content was measured in blood and skeletal muscle before and after treatment with recombinant human erythropoietin, applying the electrochemiluminescence immunoassay.. We found frataxin content to be correlated in peripheral blood mononuclear cells and skeletal muscle in drug-naive patients with Friedreich ataxia. The correlation of frataxin content in both compartments remained significant after 8 weeks of treatment. Skeletal-muscle frataxin values correlated with ataxia using the Scale for the Assessment and Rating of Ataxia score.. Our results endorse frataxin measurements in peripheral blood cells as a valid biomarker in Friedreich ataxia. Topics: Adult; Biomarkers; Biopsy; Disability Evaluation; Erythropoietin; Female; Frataxin; Friedreich Ataxia; Humans; Iron-Binding Proteins; Male; Middle Aged; Muscle, Skeletal; Statistics as Topic; Time Factors | 2011 |
Neurological effects of recombinant human erythropoietin in Friedreich's ataxia: a clinical pilot trial.
In a "proof-of-concept" study, we demonstrated that recombinant human erythropoietin (rhuEPO) increases frataxin levels in Friedreich's ataxia (FRDA) patients. We now report a 6-month open-label clinical pilot study of safety and efficacy of rhuEPO treatment in FRDA. Eight adult FRDA patients received 2.000 IU rhuEPO thrice a week subcutaneously. Clinical outcome measures included Ataxia Rating Scales. Frataxin levels and indicators for oxidative stress were assessed. Hematological parameters were monitored biweekly. Scores in Ataxia Rating Scales such as FARS (P = 0.0063) and SARA (P = 0.0045) improved significantly. Frataxin levels increased (P = 0.017) while indicators of oxidative stress such as urine 8-OHdG (P = 0.012) and peroxide levels decreased (P = 0.028). Increases in hematocrit requiring phlebotomies occurred in 4 of 8 patients. In this explorative open-label clinical pilot study, we found an evidence for clinical improvement together with a persistent increase of frataxin levels and a reduction of oxidative stress parameters in patients with FRDA receiving chronic treatment with rhuEPO. Safety monitoring with regular blood cell counts and parameters of iron metabolism is a potential limitation of this approach. Topics: 8-Hydroxy-2'-Deoxyguanosine; Adult; Deoxyguanosine; Enzyme-Linked Immunosorbent Assay; Erythropoietin; Female; Follow-Up Studies; Frataxin; Friedreich Ataxia; Humans; Iron-Binding Proteins; Lymphocytes; Male; Middle Aged; Pilot Projects; Recombinant Proteins; Severity of Illness Index; Treatment Outcome | 2008 |
Friedreich's ataxia: clinical pilot trial with recombinant human erythropoietin.
To determine the role of recombinant human erythropoietin as a possible treatment option in Friedreich's ataxia, we performed an open-label clinical pilot study. Primary outcome measure was the change of frataxin levels at week 8 versus baseline. Twelve Friedreich's ataxia patients received 5,000 units recombinant human erythropoietin three times weekly subcutaneously. Frataxin levels were measured in isolated lymphocytes by enzyme-linked immunosorbent assay. In addition, urinary 8-hydroxydeoxyguanosine and serum peroxides, were measured. Treatment with recombinant human erythropoietin showed a persistent and significant increase in frataxin levels after 8 weeks (p < 0.01). All patients showed a reduction of oxidative stress markers. Topics: Adolescent; Adult; Erythropoietin; Female; Frataxin; Friedreich Ataxia; Humans; Iron-Binding Proteins; Male; Middle Aged; Pilot Projects; Recombinant Proteins | 2007 |
6 other study(ies) available for losartan-potassium and Friedreich-Ataxia
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Skeletal muscle transcriptomics dissects the pathogenesis of Friedreich's ataxia.
In Friedreich's ataxia (FRDA), the most affected tissues are not accessible to sampling and available transcriptomic findings originate from blood-derived cells and animal models. Herein, we aimed at dissecting for the first time the pathophysiology of FRDA by means of RNA-sequencing in an affected tissue sampled in vivo.. Skeletal muscle biopsies were collected from seven FRDA patients before and after treatment with recombinant human Erythropoietin (rhuEPO) within a clinical trial. Total RNA extraction, 3'-mRNA library preparation and sequencing were performed according to standard procedures. We tested for differential gene expression with DESeq2 and performed gene set enrichment analysis with respect to control subjects.. FRDA transcriptomes showed 1873 genes differentially expressed from controls. Two main signatures emerged: (1) a global downregulation of the mitochondrial transcriptome as well as of ribosome/translational machinery and (2) an upregulation of genes related to transcription and chromatin regulation, especially of repressor terms. Downregulation of the mitochondrial transcriptome was more profound than previously shown in other cellular systems. Furthermore, we observed in FRDA patients a marked upregulation of leptin, the master regulator of energy homeostasis. RhuEPO treatment further enhanced leptin expression.. Our findings reflect a double hit in the pathophysiology of FRDA: a transcriptional/translational issue and a profound mitochondrial failure downstream. Leptin upregulation in the skeletal muscle in FRDA may represent a compensatory mechanism of mitochondrial dysfunction, which is amenable to pharmacological boosting. Skeletal muscle transcriptomics is a valuable biomarker to monitor therapeutic interventions in FRDA. Topics: Animals; Erythropoietin; Friedreich Ataxia; Humans; Iron-Binding Proteins; Leptin; Muscle, Skeletal; RNA; Transcriptome | 2023 |
Erythropoietin and small molecule agonists of the tissue-protective erythropoietin receptor increase FXN expression in neuronal cells in vitro and in Fxn-deficient KIKO mice in vivo.
Friedreich's ataxia (FA) is a progressive neurodegenerative disease caused by reduced levels of the mitochondrial protein frataxin (FXN). Recombinant human erythropoietin (rhEPO) increased FXN protein in vitro and in early clinical studies, while no published reports evaluate rhEPO in animal models of FA. STS-E412 and STS-E424 are novel small molecule agonists of the tissue-protective, but not the erythropoietic EPO receptor. We find that rhEPO, STS-E412 and STS-E424 increase FXN expression in vitro and in vivo. RhEPO, STS-E412 and STS-E424 increase FXN by up to 2-fold in primary human cortical cells and in retinoic-acid differentiated murine P19 cells. In primary human cortical cells, the increase in FXN protein was accompanied by an increase in FXN mRNA, detectable within 4 h. RhEPO and low nanomolar concentrations of STS-E412 and STS-E424 also increase FXN in normal and FA patient-derived PBMC by 20%-40% within 24 h, an effect that was comparable to that by HDAC inhibitor 4b. In vivo, STS-E412 increased Fxn mRNA and protein in wild-type C57BL6/j mice. RhEPO, STS-E412, and STS-E424 increase FXN expression in the heart of FXN-deficient KIKO mice. In contrast, FXN expression in the brains of KIKO mice increased following treatment with STS-E412 and STS-E424, but not following treatment with rhEPO. Unexpectedly, rhEPO-treated KIKO mice developed severe splenomegaly, while no splenomegaly was observed in STS-E412- or STS-E424-treated mice. RhEPO, STS-E412 and STS-E424 upregulate FXN expression in vitro at equal efficacy, however, the effects of the small molecules on FXN expression in the CNS are superior to rhEPO in vivo. Topics: Adult; Animals; Cells, Cultured; Cerebral Cortex; Erythropoietin; Female; Frataxin; Friedreich Ataxia; Histone Deacetylase Inhibitors; Humans; Iron-Binding Proteins; Leukocytes, Mononuclear; Male; Mice, Inbred C57BL; Mice, Transgenic; Middle Aged; Neurons; Neuroprotective Agents; Pyrimidines; Receptors, Erythropoietin; Recombinant Proteins; Triazoles; Young Adult | 2017 |
Skeletal muscle involvement in friedreich ataxia and potential effects of recombinant human erythropoietin administration on muscle regeneration and neovascularization.
Friedreich ataxia (FRDA) is caused by reduced expression of the mitochondrial protein frataxin. Cardiac muscle involvement has been attributed to mitochondrial dysfunction, but involvement of skeletal muscle has not been fully investigated. Improved motor skills in FRDA patients after administration of recombinant human erythropoietin (rhuEPO) have been reported. To elucidate the characteristics of skeletal muscle in FRDA and assess the potential effects of rhuEPO on skeletal muscle neovascularization and regeneration, 7 genetically confirmed FRDA patients underwent biopsy of the gastrocnemius muscle before and after administration of 3,000 international units of rhuEPO 3 times per week for 2 months. Muscle tissue was investigated using standard histologic methods, immunohistochemistry, and biochemical assays of mitochondrial enzymes. In pretreatment FRDA samples, there were neurogenic and myopathic changes and reduced capillary density versus that in healthy control biopsies (n = 4). Satellite cells were increased, but markers of satellite cell activation and differentiation did not differ from controls. Respiratory chain complex and citrate synthase activities were reduced in FRDA and remained unchanged after treatment. Administration of rhuEPO resulted in increases in muscle capillary densities and in endothelial progenitor cells in peripheral blood. These data indicate that there are morphological and biochemical abnormalities of skeletal muscle in FRDA. The rhuEPO-induced changes were subtle, but increased capillary density might result in improved oxygen supply and myofiber function. Topics: AC133 Antigen; Adult; Antigens, CD; Antigens, CD34; Electrocardiography; Endothelial Cells; Erythropoietin; Female; Flow Cytometry; Fluorescent Antibody Technique; Friedreich Ataxia; Glycoproteins; Humans; Immunoenzyme Techniques; Immunohistochemistry; Male; Middle Aged; Muscle, Skeletal; Neovascularization, Physiologic; Peptides; Recombinant Proteins; Regeneration; Regional Blood Flow; Trinucleotide Repeats | 2012 |
Carbamylated erythropoietin increases frataxin independent from the erythropoietin receptor.
Friedreich's ataxia (FRDA) is a neurodegenerative disorder caused by decreased expression of the mitochondrial protein frataxin. Recently we showed in a clinical pilot study in Friedreich's ataxia patients that recombinant human erythropoietin (rhuEPO) significantly increases frataxin-expression. In this in vitro study, we investigated the role of the erythropoietin receptor (EPO-R) in the frataxin increasing effect of rhuEPO and if nonerythropoietic carbamylated erythropoietin (CEPO), which cannot bind to the classical EPO-R increases frataxin expression.. In our experiments human erythroleukaemic K562 cells (+ EPO-R), human monocytic leukemia THP-1 cells (- EPO-R) and isolated primary lymphocytes from healthy control and FRDA patients were incubated with different concentrations of rhuEPO or CEPO. Frataxin-expression was detected by an electrochemical luminescence immunoassay (based on the principle of an ELISA).. We show that rhuEPO increases frataxin-expression in K562 cells (expressing EPO-R) as well as in THP-1 cells (without EPO-R expression). These results were confirmed by the finding that CEPO, which cannot bind to the classical EPO-R increased frataxin expression in the same concentration range as rhuEPO. In addition, we show that both EPO derivatives significantly increase frataxin-expression in vitro in control and Friedreich's ataxia patients primary lymphocytes.. Our results provide a scientific basis for further studies examining the effectiveness of nonerythropoietic derivatives of erythropoietin for the treatment of Friedreich's ataxia patients. Topics: Cell Line; Cells, Cultured; Enzyme-Linked Immunosorbent Assay; Erythropoietin; Frataxin; Friedreich Ataxia; Humans; Iron-Binding Proteins; K562 Cells; Lymphocytes; Macrophages; Recombinant Proteins | 2010 |
Recombinant human erythropoietin increases frataxin protein expression without increasing mRNA expression.
Friedreich's ataxia is an autosomal recessive neurodegenerative disease that is due to the loss of function of the frataxin protein. The molecular basis of this disease is still a matter of debate and treatments have so far focused on managing symptoms. Drugs that can increase the amount of frataxin protein offer a possible therapy for the disease. One such drug is recombinant human erythropoietin (rhu-EPO). Here, we report the effects of rhu-EPO on frataxin mRNA and protein in primary fibroblast cell cultures derived from Friedreich's ataxia patients. We observed a slight but significant increase in the amount of frataxin protein. Interestingly, we did not observe any increase in the messenger RNA expression at any of the times and doses tested, suggesting that the regulatory effects of rhu-EPO on the frataxin protein was at the post-translational level. These findings could help the evaluation of the treatment with erythropoietin as a potential therapeutic agent for Friedreich's ataxia. Topics: Adult; Erythropoietin; Female; Fibroblasts; Frataxin; Friedreich Ataxia; Gene Expression Regulation; Humans; Iron-Binding Proteins; Male; Middle Aged; Protein Processing, Post-Translational; Recombinant Proteins; RNA, Messenger; Young Adult | 2008 |
Recombinant human erythropoietin: effects on frataxin expression in vitro.
Friedreich's ataxia (FRDA) is a neurodegenerative disorder caused by decreased expression of the protein frataxin, recently described to be an iron chaperone for the assembly of iron-sulphur clusters in the mitochondria, causing iron accumulation in mitochondria, oxidative stress and cell damage. Searching for compounds that could possibly influence frataxin expression, we found that the cytokine recombinant human erythropoietin (rhuEPO) significantly increases frataxin expression by a still unknown mechanism.. Isolated lymphocytes from FRDA patients, isolated human cardiac cells (fibroblasts and myocytes) from patients undergoing heart transplantation and P19 mouse cells (neuronal typ), were incubated with different concentrations of rhuEPO, and immunoblot was carried out for the detection of frataxin.. We show for the first time that the cytokine recombinant human erythropoietin (rhuEPO) can, additionally to its reported neuro- and cardioprotective properties, increase frataxin expression in vitro. We show that rhuEPO significantly increases frataxin expression in primary lymphocytes from patients with Friedreich's ataxia. Further we show that rhuEPO can also increase frataxin expression in many other cell types; among them the most affected cell types in FRDA such as neurones and cardiac cells.. Our results provide a scientific basis for further studies examining the effectiveness of this agent for the treatment of FRDA patients. Topics: Cell Line; Cells, Cultured; Erythropoietin; Fibroblasts; Frataxin; Friedreich Ataxia; Humans; Iron-Binding Proteins; Lymphocytes; Myocytes, Cardiac; Neurons; Recombinant Proteins | 2005 |