scholarly journals Mitochondrial Abnormalities in Induced Pluripotent Stem Cells-Derived Motor Neurons from Patients with Riboflavin Transporter Deficiency

Antioxidants ◽  
2020 ◽  
Vol 9 (12) ◽  
pp. 1252
Author(s):  
Fiorella Colasuonno ◽  
Enrico Bertini ◽  
Marco Tartaglia ◽  
Claudia Compagnucci ◽  
Sandra Moreno

Riboflavin transporter deficiency (RTD) is a childhood-onset neurodegenerative disorder characterized by sensorineural deafness and motor neuron degeneration. Since riboflavin plays key functions in biological oxidation-reduction reactions, energy metabolism pathways involving flavoproteins are affected in RTD. We recently generated induced pluripotent stem cell (iPSC) lines from affected individuals as an in vitro model of the disease and documented mitochondrial impairment in these cells, dramatically impacting cell redox status. This work extends our study to motor neurons (MNs), i.e., the cell type most affected in patients with RTD. Altered intracellular distribution of mitochondria was detected by confocal microscopic analysis (following immunofluorescence for superoxide dismutase 2 (SOD2), as a dual mitochondrial and antioxidant marker), and βIII-Tubulin, as a neuronal marker. We demonstrate significantly lower SOD2 levels in RTD MNs, as compared to their healthy counterparts. Mitochondrial ultrastructural abnormalities were also assessed by focused ion beam/scanning electron microscopy. Moreover, we investigated the effects of combination treatment using riboflavin and N-acetylcysteine, which is a widely employed antioxidant. Overall, our findings further support the potential of patient-specific RTD models and provide evidence of mitochondrial alterations in RTD-related iPSC-derived MNs—emphasizing oxidative stress involvement in this rare disease. We also provide new clues for possible therapeutic strategies aimed at correcting mitochondrial defects, based on the use of antioxidants.

Author(s):  
Fiorella Colasuonno ◽  
Enrico Bertini ◽  
Marco Tartaglia ◽  
Claudia Compagnucci ◽  
Sandra Moreno

Riboflavin transporter deficiency (RTD) is a childhood-onset neurodegenerative disorder characterized by sensorineural deafness and motor neuron degeneration. Since riboflavin plays key functions in biological oxidation-reduction reactions, energy metabolism pathways involving flavoproteins are affected in RTD. We recently generated iPSC lines from affected individuals as an in vitro model of the disease and documented mitochondrial impairment in these cells dramatically impacting cell redox status. In the present work, we extend our study to motor neurons (MNs), i.e., the cell type mostly affected in patients with RTD. Altered intracellular distribution of mitochondria was detected by confocal microscopic analysis, following immunofluorescence for superoxide dismutase 2 (SOD2), as a dual mitochondrial and antioxidant marker, and βIII Tubulin, as neuronal marker. We demonstrate significantly lower SOD2 levels in RTD MNs, as compared to their healthy counterparts. Mitochondrial ultrastructural abnormalities were also assessed by Focused Ion Beam/Scanning Electron Microscopy. Moreover, we investigated the effects of combination treatment using riboflavin and N-acetylcysteine, which is a widely employed antioxidant. Overall, our findings further support the potential of patient specific RTD models, and provide evidence of mitochondrial alterations in RTD-related iPSC-derived MNs, emphasizing oxidative stress involvement in this rare disease. We also provide new clues for possible therapeutic strategies, aimed at correcting mitochondrial defects, based on the use of antioxidants.


2016 ◽  
Vol 2016 ◽  
pp. 1-14 ◽  
Author(s):  
Ji-Yon Kim ◽  
So-Youn Woo ◽  
Young Bin Hong ◽  
Heesun Choi ◽  
Jisoo Kim ◽  
...  

The Charcot-Marie-Tooth disease 2F (CMT2F) and distal hereditary motor neuropathy 2B (dHMN2B) are caused by autosomal dominantly inherited mutations of the heat shock 27 kDa protein 1 (HSPB1) gene and there are no specific therapies available yet. Here, we assessed the potential therapeutic effect of HDAC6 inhibitors on peripheral neuropathy with HSPB1 mutation using in vitro model of motor neurons derived from induced pluripotent stem cells (iPSCs) of CMT2F and dHMN2B patients. The absolute velocity of mitochondrial movements and the percentage of moving mitochondria in axons were lower both in CMT2F-motor neurons and in dHMN2B-motor neurons than those in controls, and the severity of the defective mitochondrial movement was different between the two disease models. CMT2F-motor neurons and dHMN2B-motor neurons also showed reduced α-tubulin acetylation compared with controls. The newly developed HDAC6 inhibitors, CHEMICAL X4 and CHEMICAL X9, increased acetylation of α-tubulin and reversed axonal movement defects of mitochondria in CMT2F-motor neurons and dHMN2B-motor neurons. Our results suggest that the neurons derived from patient-specific iPSCs can be used in drug screening including HDAC6 inhibitors targeting peripheral neuropathy.


2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Mariana L. Casalia ◽  
Juan Cruz Casabona ◽  
Corina García ◽  
Verónica Cavaliere Candedo ◽  
Héctor Ramiro Quintá ◽  
...  

Abstract Background Self-limited Childhood Epilepsies are the most prevalent epileptic syndrome in children. Its pathogenesis is unknown. In this disease, symptoms resolve spontaneously in approximately 50% of patients when maturity is reached, prompting to a maturation problem. The purpose of this study was to understand the molecular bases of this disease by generating and analyzing induced pluripotent stem cell-derived neurons from a family with 7 siblings, among whom 4 suffer from this disease. Methods Two affected siblings and, as controls, a healthy sister and the unaffected mother of the family were studied. Using exome sequencing, a homozygous variant in the FYVE, RhoGEF and PH Domain Containing 6 gene was identified in the patients as a putative genetic factor that could contribute to the development of this familial disorder. After informed consent was signed, skin biopsies from the 4 individuals were collected, fibroblasts were derived and reprogrammed and neurons were generated and characterized by markers and electrophysiology. Morphological, electrophysiological and gene expression analyses were performed on these neurons. Results Bona fide induced pluripotent stem cells and derived neurons could be generated in all cases. Overall, there were no major shifts in neuronal marker expression among patient and control-derived neurons. Compared to two familial controls, neurons from patients showed shorter axonal length, a dramatic reduction in synapsin-1 levels and cytoskeleton disorganization. In addition, neurons from patients developed a lower action potential threshold with time of in vitro differentiation and the amount of current needed to elicit an action potential (rheobase) was smaller in cells recorded from NE derived from patients at 12 weeks of differentiation when compared with shorter times in culture. These results indicate an increased excitability in patient cells that emerges with the time in culture. Finally, functional genomic analysis showed a biased towards immaturity in patient-derived neurons. Conclusions We are reporting the first in vitro model of self-limited childhood epilepsy, providing the cellular bases for future in-depth studies to understand its pathogenesis. Our results show patient-specific neuronal features reflecting immaturity, in resonance with the course of the disease and previous imaging studies.


2021 ◽  
Vol 14 (2) ◽  
pp. dmm046391
Author(s):  
Alessia Niceforo ◽  
Chiara Marioli ◽  
Fiorella Colasuonno ◽  
Stefania Petrini ◽  
Keith Massey ◽  
...  

ABSTRACTThe cytoskeletal network plays a crucial role in the differentiation, morphogenesis, function and homeostasis of the nervous tissue, so that alterations in any of its components may lead to neurodegenerative diseases. Riboflavin transporter deficiency (RTD), a childhood-onset disorder characterized by degeneration of motor neurons (MNs), is caused by biallelic mutations in genes encoding the human riboflavin (RF) transporters. In a patient-specific induced pluripotent stem cells (iPSCs) model of RTD, we recently demonstrated altered cell-cell contacts, energy dysmetabolism and redox imbalance. The present study focuses on cytoskeletal composition and dynamics associated to RTD, utilizing patients' iPSCs and derived MNs. Abnormal expression and distribution of α- and β-tubulin (α- and β-TUB), as well as imbalanced tyrosination of α-TUB, accompanied by an impaired ability to re-polymerize after nocodazole treatment, were found in RTD patient-derived iPSCs. Following differentiation, MNs showed consistent changes in TUB content, which was associated with abnormal morphofunctional features, such as neurite length and Ca2+ homeostasis, suggesting impaired differentiation. Beneficial effects of RF supplementation, alone or in combination with the antioxidant molecule N-acetyl cystine (NAC), were assessed. RF administration resulted in partially improved cytoskeletal features in patients' iPSCs and MNs, suggesting that redundancy of transporters may rescue cell functionality in the presence of adequate concentrations of the vitamin. Moreover, supplementation with NAC was demonstrated to be effective in restoring all the considered parameters, when used in combination with RF, thus supporting the therapeutic use of both compounds.


2014 ◽  
Vol 42 (5) ◽  
pp. 1270-1274 ◽  
Author(s):  
Laura Ferraiuolo

Amyotrophic lateral sclerosis (ALS) is a fatal neurodegenerative disorder affecting the motor nerves. At present, there is no effective therapy for this devastating disease and only one Food and Drug Administration (FDA)-approved drug, riluzole, is known to moderately extend survival. In the last decade, the field of ALS has made a remarkable leap forward in understanding some of the genetic causes of this disease and the role that different cell types play in the degenerative mechanism affecting motor neurons. In particular, astrocytes have been implicated in disease progression, and multiple studies suggest that these cells are valuable therapeutic targets. Recent technological advancements have provided new tools to generate astrocytes from ALS patients either from post-mortem biopsies or from skin fibroblasts through genetic reprogramming. The advent of induced pluripotent stem cell (iPSC) technology and the newly developed induced neural progenitor cells (iNPCs) have created unprecedented exciting opportunities to unravel the mechanisms involved in neurodegeneration and initiate high-throughput drug screenings.


2020 ◽  
Vol 21 (19) ◽  
pp. 7402 ◽  
Author(s):  
Chiara Marioli ◽  
Valentina Magliocca ◽  
Stefania Petrini ◽  
Alessia Niceforo ◽  
Rossella Borghi ◽  
...  

Mitochondrial dysfunction is a key element in the pathogenesis of neurodegenerative disorders, such as riboflavin transporter deficiency (RTD). This is a rare, childhood-onset disease characterized by motoneuron degeneration and caused by mutations in SLC52A2 and SLC52A3, encoding riboflavin (RF) transporters (RFVT2 and RFVT3, respectively), resulting in muscle weakness, ponto-bulbar paralysis and sensorineural deafness. Based on previous findings, which document the contribution of oxidative stress in RTD pathogenesis, we tested possible beneficial effects of several antioxidants (Vitamin C, Idebenone, Coenzyme Q10 and EPI-743, either alone or in combination with RF) on the morphology and function of neurons derived from induced pluripotent stem cells (iPSCs) from two RTD patients. To identify possible improvement of the neuronal morphotype, neurite length was measured by confocal microscopy after β-III tubulin immunofluorescent staining. Neuronal function was evaluated by determining superoxide anion generation by MitoSOX assay and intracellular calcium (Ca2+) levels, using the Fluo-4 probe. Among the antioxidants tested, EPI-743 restored the redox status, improved neurite length and ameliorated intracellular calcium influx into RTD motoneurons. In conclusion, we suggest that antioxidant supplementation may have a role in RTD treatment.


2012 ◽  
Vol 2012 ◽  
pp. 1-10 ◽  
Author(s):  
Thekkeparambil Chandrabose Srijaya ◽  
Padmaja Jayaprasad Pradeep ◽  
Rosnah Binti Zain ◽  
Sabri Musa ◽  
Noor Hayaty Abu Kasim ◽  
...  

Induced pluripotent stem cell-based therapy for treating genetic disorders has become an interesting field of research in recent years. However, there is a paucity of information regarding the applicability of induced pluripotent stem cells in dental research. Recent advances in the use of induced pluripotent stem cells have the potential for developing disease-specific iPSC linesin vitrofrom patients. Indeed, this has provided a perfect cell source for disease modeling and a better understanding of genetic aberrations, pathogenicity, and drug screening. In this paper, we will summarize the recent progress of the disease-specific iPSC development for various human diseases and try to evaluate the possibility of application of iPS technology in dentistry, including its capacity for reprogramming some genetic orodental diseases. In addition to the easy availability and suitability of dental stem cells, the approach of generating patient-specific pluripotent stem cells will undoubtedly benefit patients suffering from orodental disorders.


Author(s):  
Elliot W. Swartz ◽  
Greg Shintani ◽  
Jijun Wan ◽  
Joseph S. Maffei ◽  
Sarah H. Wang ◽  
...  

SummaryThe failure of the neuromuscular junction (NMJ) is a key component of degenerative neuromuscular disease, yet how NMJs degenerate in disease is unclear. Human induced pluripotent stem cells (hiPSCs) offer the ability to model disease via differentiation toward affected cell types, however, the re-creation of an in vitro neuromuscular system has proven challenging. Here we present a scalable, all-hiPSC-derived co-culture system composed of independently derived spinal motor neurons (MNs) and skeletal myotubes (sKM). In a model of C9orf72-associated disease, co-cultures form functional NMJs that can be manipulated through optical stimulation, eliciting muscle contraction and measurable calcium flux in innervated sKM. Furthermore, co-cultures grown on multi-electrode arrays (MEAs) permit the pharmacological interrogation of neuromuscular physiology. Utilization of this co-culture model as a tunable, patient-derived system may offer significant insights into NMJ formation, maturation, repair, or pathogenic mechanisms that underlie NMJ dysfunction in disease.


Circulation ◽  
2018 ◽  
Vol 138 (Suppl_1) ◽  
Author(s):  
Michelle R Santoso ◽  
Yuko Tada ◽  
Gentaro Ikeda ◽  
Ji-Hye Jung ◽  
Evgeniya Vaskova ◽  
...  

Background: Induced pluripotent stem cells (iPSCs) and their differentiated cardiomyocytes (iCMs) have tremendous potential as patient-specific therapy for myocardial injury (MI). Our previous work showed that the iCMs restore the injured murine myocardium through secretion of paracrine factors, modulating apoptotic pathways to restore the murine peri-infarct region (PIR). Hypothesis: iCM-derived exosomes (iCM-Ex), a major constituent of the iCM secretome, may salvage the injured cardiomyocytes in the PIR. Methods: iCM-Ex were precipitated from iCM supernatant and characterized using various molecular analyses. Immunodeficient mice sustained MIs and received iCMs, iCM-Ex, or PBS control via direct intramyocardial injection into the PIR. Cardiac MRI assessed LV ejection fraction (LVEF) and viability at 2- and 4-week post-injection. iCMs, iCM-Ex, and PIR tissue were isolated for molecular and histological analyses. Results: iCM-Ex measured approximately 142 nm and expressed CD63 and CD9. iCM and iCM-Ex miRNA profiles had significant overlap, indicating that exosomal content was reflective of the parent cell. In vitro iCM apoptosis was increased significantly by hypoxia and exosome biogenesis inhibition while iCM-Ex or rapamycin reduced iCM apoptosis (p<0.05, vs. control). Mice treated with iCMs or iCM-Ex had significantly improved LVEF and LV viability compared to the control (p<0.05). Apoptosis and fibrosis were significantly reduced in iCM- and iCM-Ex treated mice. Autophagy and associated mTOR signaling pathway were significantly enhanced in iCM-Ex treatment group. Conclusions: iCM-Ex demonstrated similar efficacy as the iCMs in improving post-MI cardiac function by regulating autophagy and apoptosis of hypoxia injured cardiomyocytes. This finding represents the potential of cell-free, patient-specific biologic to treat ischemic cardiomyopathy by stimulation of an endogenous repair mechanism.


2019 ◽  
Vol 2019 ◽  
pp. 1-15 ◽  
Author(s):  
Laís Vicari de Figueiredo Pessôa ◽  
Pedro Ratto Lisboa Pires ◽  
Maite del Collado ◽  
Naira Caroline Godoy Pieri ◽  
Kaiana Recchia ◽  
...  

Introduction. Pluripotent stem cells are believed to have greater clinical potential than mesenchymal stem cells due to their ability to differentiate into almost any cell type of an organism, and since 2006, the generation of patient-specific induced pluripotent stem cells (iPSCs) has become possible in multiple species. Objectives. We hypothesize that different cell types respond differently to the reprogramming process; thus, the goals of this study were to isolate and characterize equine adult and fetal cells and induce these cells to pluripotency for future regenerative and translational purposes. Methods. Adult equine fibroblasts (eFibros) and mesenchymal cells derived from the bone marrow (eBMmsc), adipose tissue (eADmsc), and umbilical cord tissue (eUCmsc) were isolated, their multipotency was characterized, and the cells were induced in vitro into pluripotency (eiPSCs). eiPSCs were generated through a lentiviral system using the factors OCT4, SOX2, c-MYC, and KLF4. The morphology and in vitro pluripotency maintenance potential (alkaline phosphatase detection, embryoid body formation, in vitro spontaneous differentiation, and expression of pluripotency markers) of the eiPSCs were characterized. Additionally, a miRNA profile analysis of the mesenchymal and eiPSCs was performed. Results. Multipotent cells were successfully isolated, but the eBMmsc failed to generate eiPSCs. The eADmsc-, eUCmsc-, and eFibros-derived iPSCs were positive for alkaline phosphatase, OCT4 and NANOG, were exclusively dependent on bFGF, and formed embryoid bodies. The miRNA profile revealed a segregated pattern between the eiPSCs and multipotent controls: the levels of miR-302/367 and the miR-92 family were increased in the eiPSCs, while the levels of miR-23, miR-27, and miR-30, as well as the let-7 family were increased in the nonpluripotent cells. Conclusions. We were able to generate bFGF-dependent iPSCs from eADmsc, eUCmsc, and eFibros with human OSKM, and the miRNA profile revealed that clonal lines may respond differently to the reprogramming process.


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