scholarly journals Engineering Organoids for in vitro Modeling of Phenylketonuria

2022 ◽  
Vol 14 ◽  
Author(s):  
Alice C. Borges ◽  
Kerensa Broersen ◽  
Paula Leandro ◽  
Tiago G. Fernandes

Phenylketonuria is a recessive genetic disorder of amino-acid metabolism, where impaired phenylalanine hydroxylase function leads to the accumulation of neurotoxic phenylalanine levels in the brain. Severe cognitive and neuronal impairment are observed in untreated/late-diagnosed patients, and even early treated ones are not safe from life-long sequelae. Despite the wealth of knowledge acquired from available disease models, the chronic effect of Phenylketonuria in the brain is still poorly understood and the consequences to the aging brain remain an open question. Thus, there is the need for better predictive models, able to recapitulate specific mechanisms of this disease. Human induced pluripotent stem cells (hiPSCs), with their ability to differentiate and self-organize in multiple tissues, might provide a new exciting in vitro platform to model specific PKU-derived neuronal impairment. In this review, we gather what is known about the impact of phenylalanine in the brain of patients and highlight where hiPSC-derived organoids could contribute to the understanding of this disease.

Pharmaceutics ◽  
2021 ◽  
Vol 13 (6) ◽  
pp. 892
Author(s):  
Elisa L. J. Moya ◽  
Elodie Vandenhaute ◽  
Eleonora Rizzi ◽  
Marie-Christine Boucau ◽  
Johan Hachani ◽  
...  

Central nervous system (CNS) diseases are one of the top causes of death worldwide. As there is a difficulty of drug penetration into the brain due to the blood–brain barrier (BBB), many CNS drugs treatments fail in clinical trials. Hence, there is a need to develop effective CNS drugs following strategies for delivery to the brain by better selecting them as early as possible during the drug discovery process. The use of in vitro BBB models has proved useful to evaluate the impact of drugs/compounds toxicity, BBB permeation rates and molecular transport mechanisms within the brain cells in academic research and early-stage drug discovery. However, these studies that require biological material (animal brain or human cells) are time-consuming and involve costly amounts of materials and plastic wastes due to the format of the models. Hence, to adapt to the high yields needed in early-stage drug discoveries for compound screenings, a patented well-established human in vitro BBB model was miniaturized and automated into a 96-well format. This replicate met all the BBB model reliability criteria to get predictive results, allowing a significant reduction in biological materials, waste and a higher screening capacity for being extensively used during early-stage drug discovery studies.


2021 ◽  
Author(s):  
Marine A Krzisch ◽  
Hao A Wu ◽  
Bingbing Yuan ◽  
Troy W. Whitfield ◽  
X. Shawn Liu ◽  
...  

Abnormal neuronal development in Fragile X syndrome (FXS) is poorly understood. Data on FXS patients remain scarce and FXS animal models have failed to yield successful therapies. In vitro models do not fully recapitulate the morphology and function of human neurons. Here, we co-injected neural precursor cells (NPCs) from FXS patient-derived and corrected isogenic control induced pluripotent stem cells into the brain of neonatal immune-deprived mice. The transplanted cells populated the brain and a proportion differentiated into neurons and glial cells. Single-cell RNA sequencing of transplanted cells revealed upregulated excitatory synaptic transmission and neuronal differentiation pathways in FXS neurons. Immunofluorescence analyses showed accelerated maturation of FXS neurons after an initial delay. Additionally, increased percentages of Arc- and Egr1-positive FXS neurons and wider dendritic protrusions of mature FXS striatal medium spiny neurons pointed to an increase in synaptic activity and synaptic strength as compared to control. This transplantation approach provides new insights into the alterations of neuronal development in FXS by facilitating physiological development of cells in a 3D context, and could be used to test new therapeutic compounds correcting neuronal development defects in FXS.


Author(s):  
Richard McCarty

Several exciting lines of research have emerged from the study of animal models of mental disorders. This chapter presents seven opportunities for enhancing the diagnosis and treatment of mental disorders. They include improvements to the system for diagnosis of mental disorders, use of induced pluripotent stem cells from patients to generate neuronal cultures for in vitro determination of effective drug therapies for those individuals, use of data-mining techniques for understanding patient variability, a commitment to a greater focus on the prevention of mental disorders, innovative uses of smartphones to track patients and individuals at high risk of developing a mental disorder, and developing next-generation therapies and delivery systems that target a specific area of the brain rather than the entire brain. A common theme in these seven thoughts for the future is a commitment to bringing precision medicine tools to the treatment of patients with mental disorders.


Toxics ◽  
2019 ◽  
Vol 7 (4) ◽  
pp. 56 ◽  
Author(s):  
Megan Culbreth ◽  
Michael Aschner

Methylmercury (MeHg) has conventionally been investigated for effects on nervous system development. As such, epigenetic modifications have become an attractive mechanistic target, and research on MeHg and epigenetics has rapidly expanded in the past decade. Although, these inquiries are a recent advance in the field, much has been learned in regards to MeHg-induced epigenetic modifications, particularly in the brain. In vitro and in vivo controlled exposure studies illustrate that MeHg effects microRNA (miRNA) expression, histone modifications, and DNA methylation both globally and at individual genes. Moreover, some effects are transgenerationally inherited, as organisms not directly exposed to MeHg exhibited biological and behavioral alterations. miRNA expression generally appears to be downregulated consequent to exposure. Further, global histone acetylation also seems to be reduced, persist at distinct gene promoters, and is contemporaneous with enhanced histone methylation. Moreover, global DNA methylation appears to decrease in brain-derived tissues, but not in the liver; however, selected individual genes in the brain are hypermethylated. Human epidemiological studies have also identified hypo- or hypermethylated individual genes, which correlated with MeHg exposure in distinct populations. Intriguingly, several observed epigenetic modifications can be correlated with known mechanisms of MeHg toxicity. Despite this knowledge, however, the functional consequences of these modifications are not entirely evident. Additional research will be necessary to fully comprehend MeHg-induced epigenetic modifications and the impact on the toxic response.


2019 ◽  
Vol 3 (Supplement_1) ◽  
Author(s):  
Eun-kyung Choi ◽  
Young-Ah Seo

Abstract Objectives Hemochromatosis is a frequent genetic disorder characterized by the accumulation of excess iron across tissues. Mutations in the FPN1 gene, encoding a cell-surface iron exporter ferroportin (Fpn), are responsible for hemochromatosis type 4, also known as ferroportin disease. Recently, Fpn has been implicated in the regulation of manganese (Mn), another essential nutrient required for numerous cellular enzymes. However, the roles of Fpn in Mn regulation remain ill defined, and the impact of disease mutations on cellular Mn levels is unknown. Thus, this study aimed to define the role of Fpn in Mn regulation and determine the functional consequences of ferroportin disease mutations in cellular Mn levels. Methods Thus far, over 50 mutations in Fpn have been identified in hemochromatosis type 4/ferroportin disease. To test whether these mutations alter cellular Mn metabolism, we constructed an expression vector encoding human Fpn with a C-terminal HA epitope tag and introduced nine clinically relevant mutations by site-directed mutagenesis. Based on previously reported in vitro functional results, we selected five ferroportin disease mutations from each of the two groups: five loss-of-function (LOF) mutations (G80S, R88G, D157G, D157Y, and V162Δ) and four gain-of-function (GOF) mutations (N144H, N144T, C326S, and and S338R). Results Here, we provide evidence that Fpn can export Mn from cells into extracellular space. Fpn appears to play protective roles in Mn-induced cellular toxicity and oxidative stress. Finally, disease mutations interfere with Fpn's role in controlling Mn levels as well as the stability of Fpn. Conclusions These results define the function of Fpn as an exporter of both iron and Mn and highlight the potential involvement of Mn dysregulation in ferroportin disease. Funding Sources National Institutes of Health (NIH) to Y.A.S. (K99/R00 ES024340).


2020 ◽  
Vol 22 (Supplement_2) ◽  
pp. ii64-ii64
Author(s):  
Hassan Azari ◽  
Nasser Nassiri Koopaei ◽  
Mohammad-Zaman Nouri ◽  
Jesse D Hall ◽  
Nancy D Denslow ◽  
...  

Abstract INTRODUCTION Extracellular vesicles (EVs) have been harvested from many plant sources, some of which have anti-cancer effects and some could be used as therapeutic nanodelivery vectors. Hemp plant is a natural source of cannabinoids, of which delta 9-tetrahydroxicannabinol (THC) and cannabidiol (CBD) have proven anti-cancer proprieties. HYPOTHESIS We hypothesized that hemp EVs are enriched in cannabinoids and their application will reduce glioblastoma (GBM) tumor progression. APPROACH EVs were isolated from the hemp plant using ultracentrifugation. Nanotracking analysis, electron microscopy and liquid chromatography tandem mass spectrometry (LC-MS/MS) were utilized to characterize EVs. GBM cell lines were cultured in the neuropshere assay to evaluate hemp EVs anti-glioma effects. Fluorescent-labelled EVs were used to evaluate their brain tissue distribution in orthotopic patient-derived GBM xenografts. RESULTS Hemp EVs have a median diameter of 112.6nm with a typical lipid-bilayer structure. LC-MS/MS have shown that while cannabidiolic, cannabigerolic, and tetrahydroxicannabinolic acids represent 69.1 ± 2.1%, 19.1 ± 1.6%, 6.5 ± 0.54% of the total cannabinoids in hemp EVs, CBD and THC only make 4.75 ± 0.26%, and 0.5 ± 0.3%. Hemp EVs are potent anti-glioma agents with a 7-day LD-50 of 1.04µM and 2.4µM [based on EVs total cannabinoid content] for KR-158 and L0 GBM lines, respectively. Compared to the vehicle, overnight incubation of L0 cells with 1µM hemp EVs significantly reduced GBM cell migration (630.3 ± 61.43 vs 143.7 ± 8.7). Intranasal administration of hemp EVs led to a widespread distribution in tumor bearing brain including GBM tumor core. CONCLUSION Based on these results, hemp EVs with enriched cannabinoid content exert antiglioma effect in-vitro and when delivered intranasally, are widely distributed throughout the brain and within the tumor of PDX animals. Further experiments are ongoing to address the impact of nasally-delivered hemp EVs on tumor progression and compare to the application of purified acidic cannabinoids.


2014 ◽  
Vol 25 (6) ◽  
Author(s):  
Lauren E. Salminen ◽  
Robert H. Paul

AbstractNormal aging involves a gradual breakdown of physiological processes that leads to a decline in cognitive functions and brain integrity, yet the onset and progression of decline are variable among older individuals. While many biological changes may contribute to this degree of variability, oxidative stress is a key mechanism of the aging process that can cause direct damage to cellular architecture within the brain. Oligodendrocytes are at a high risk for oxidative damage due to their role in myelin maintenance and production and limited repair mechanisms, suggesting that white matter may be particularly vulnerable to oxidative activity. Antioxidant defense enzymes within the brain, such as superoxide dismutase (SOD), catalase (CAT), glutathione peroxidase (GPx), and glutathione-S-transferase (GST), are crucial for breaking down the harmful end products of oxidative phosphorylation. Previous studies have revealed that allele variations of polymorphisms that encode these antioxidants are associated with abnormalities in SOD, CAT, GPx, and GST activity in the central nervous system. This review will focus on the role of oxidative stress in the aging brain and the impact of decreased antioxidant defense on brain integrity and cognitive function. Directions for future research investigations of antioxidant defense genes will also be discussed.


2021 ◽  
Vol 22 (19) ◽  
pp. 10254
Author(s):  
Johanna Heider ◽  
Sabrina Vogel ◽  
Hansjürgen Volkmer ◽  
Ricarda Breitmeyer

Neuropsychiatric disorders such as schizophrenia or autism spectrum disorder represent a leading and growing burden on worldwide mental health. Fundamental lack in understanding the underlying pathobiology compromises efficient drug development despite the immense medical need. So far, antipsychotic drugs reduce symptom severity and enhance quality of life, but there is no cure available. On the molecular level, schizophrenia and autism spectrum disorders correlate with compromised neuronal phenotypes. There is increasing evidence that aberrant neuroinflammatory responses of glial cells account for synaptic pathologies through deregulated communication and reciprocal modulation. Consequently, microglia and astrocytes emerge as central targets for anti-inflammatory treatment to preserve organization and homeostasis of the central nervous system. Studying the impact of neuroinflammation in the context of neuropsychiatric disorders is, however, limited by the lack of relevant human cellular test systems that are able to represent the dynamic cellular processes and molecular changes observed in human tissue. Today, patient-derived induced pluripotent stem cells offer the opportunity to study neuroinflammatory mechanisms in vitro that comprise the genetic background of affected patients. In this review, we summarize the major findings of iPSC-based microglia and astrocyte research in the context of neuropsychiatric diseases and highlight the benefit of 2D and 3D co-culture models for the generation of efficient in vitro models for target screening and drug development.


Author(s):  
Yumei Luo ◽  
Mimi Zhang ◽  
Yapei Chen ◽  
Yaoyong Chen ◽  
Detu Zhu

The outbreak of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) and its rapid international spread has caused the coronavirus disease 2019 (COVID-19) pandemics, which is a global public health crisis. Thus, there is an urgent need to establish biological models to study the pathology of SARS-CoV-2 infection, which not only involves respiratory failure, but also includes dysregulation of other organs and systems, including the brain, heart, liver, intestines, pancreas, kidneys, eyes, and so on. Cellular and organoid models derived from human induced pluripotent stem cells (iPSCs) are ideal tools for in vitro simulation of viral life cycles and drug screening to prevent the reemergence of coronavirus. These iPSC-derived models could recapitulate the functions and physiology of various human cell types and assemble the complex microenvironments similar with those in the human organs; therefore, they can improve the study efficiency of viral infection mechanisms, mimic the natural host-virus interaction, and be suited for long-term experiments. In this review, we focus on the application of in vitro iPSC-derived cellular and organoid models in COVID-19 studies.


Author(s):  
Mariya S. Pravdivtseva ◽  
Oleg B. Shevelev ◽  
Vadim V. Yanshole ◽  
Mikhail P. Moshkin ◽  
Igor V. Koptyug ◽  
...  

AbstractThe impact of alcohol on the body can be investigated with NMR spectroscopy in vitro, which can detect a wide range of metabolites but preparing samples includes tissue biopsy. Blood sampling is less invasive, but blood metabolic content might not reflect the changes occurring in other tissues. Thus, this study aimed to investigate the liver, brain, and serum metabolism and evaluate the link between tissues and serum metabolic content. Two experimental groups with ten outbred rats each were provided intragastrically with water (control group) and 50% ethanol solution (alcohol group) for 28 days. 1H NMR spectroscopy in vitro was performed on the brain cortex, liver, and serum samples. Student’s t test with Holm–Bonferroni correction was used to investigate significant differences between groups. Partial least-squares discriminant analysis (PLS-DA) and two-way ANOVA were performed to compare liver and serum, brain and serum. In all, 38, 37, and 21 metabolites were identified in the liver, brain, and serum samples, respectively. Significant differences for three metabolites were found in the liver (alanine, proline, and glutathione, p < 0.002) and four in serum (lactate, betaine, acetate, and formic acid, p < 0.002) were detected between the control and alcohol groups. The contents of glucose, betaine, and isoleucine were correlated (r > 0.65) between serum and liver samples. PLS-DA determined separation between all tissues (p < 0.001) and between control and alcohol groups only for liver and serum (p < 0.001). Alcohol had a more substantial effect on liver and serum metabolism than on the brain.


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