scholarly journals Antioxidants in Down Syndrome: From Preclinical Studies to Clinical Trials

Antioxidants ◽  
2020 ◽  
Vol 9 (8) ◽  
pp. 692 ◽  
Author(s):  
Noemí Rueda Revilla ◽  
Carmen Martínez-Cué
Keyword(s):  
Oxidative Stress ◽  
Clinical Trials ◽  
Down Syndrome ◽  
Cognitive Dysfunction ◽  
Cognitive Deficits ◽  
Later Life ◽  
Chromosome 21 ◽  
Therapeutic Interventions ◽  
Early Event ◽  
Preclinical Studies

There is currently no effective pharmacological therapy to improve the cognitive dysfunction of individuals with Down syndrome (DS). Due to the overexpression of several chromosome 21 genes, cellular and systemic oxidative stress (OS) is one of the most important neuropathological processes that contributes to the cognitive deficits and multiple neuronal alterations in DS. In this condition, OS is an early event that negatively affects brain development, which is also aggravated in later life stages, contributing to neurodegeneration, accelerated aging, and the development of Alzheimer’s disease neuropathology. Thus, therapeutic interventions that reduce OS have been proposed as a promising strategy to avoid neurodegeneration and to improve cognition in DS patients. Several antioxidant molecules have been proven to be effective in preclinical studies; however, clinical trials have failed to show evidence of the efficacy of different antioxidants to improve cognitive deficits in individuals with DS. In this review we summarize preclinical studies of cell cultures and mouse models, as well as clinical studies in which the effect of therapies which reduce oxidative stress and mitochondrial alterations on the cognitive dysfunction associated with DS have been assessed.

Preclinical studies conducted on nanozyme antioxidants: shortcomings and challenges based on US FDA regulations

Nanomedicine ◽  
2021 ◽  
Author(s):  
Milad Ghorbani ◽  
Zhila Izadi ◽  
Samira Jafari ◽  
Eudald Casals ◽  
Foroogh Rezaei ◽  
...  
Keyword(s):  
Oxidative Stress ◽  
Clinical Trials ◽  
Clinical Studies ◽  
In Vivo Studies ◽  
Preclinical Studies ◽  
Future Studies ◽  
Clinical Stages ◽  
Us Fda ◽  
Considerable Body

The wide prevalence of oxidative stress-induced diseases has led to a growing demand for antioxidant therapeutics worldwide. Nanozyme antioxidants are drawing enormous attention as practical alternatives for conventional antioxidants. The considerable body of research over the last decade and the promising results achieved signify the potential of nanozyme antioxidants to secure a place in the expanding market of antioxidant therapeutics. Nonetheless, there is no report on clinical trials for their further evaluation. Through analyzing in-depth selected papers which have conducted in vivo studies on nanozyme antioxidants, this review aims to pinpoint and discuss possible reasons impeding development of research toward clinical studies and to offer some practical solutions for future studies to bridge the gap between preclinical and clinical stages.

scholarly journals Down Syndrome: Genes, Model Systems, and Progress towards Pharmacotherapies and Clinical Trials for Cognitive Deficits

2013 ◽  
Vol 141 (4) ◽  
pp. 260-271 ◽  
Author(s):  
J. Busciglio ◽  
G. Capone ◽  
J.P. O'Byran ◽  
K.J. Gardiner
Keyword(s):  
Clinical Trials ◽  
Down Syndrome ◽  
Cognitive Deficits ◽  
Model Systems

scholarly journals Altered Hippocampal-Prefrontal Neural Dynamics in Mouse Models of Down Syndrome

2019 ◽  
Author(s):  
Pishan Chang ◽  
Daniel Bush ◽  
Stephanie Schorge ◽  
Mark Good ◽  
Tara Canonica ◽  
...  
Keyword(s):  
Down Syndrome ◽  
Mouse Models ◽  
Cognitive Deficits ◽  
Memory Task ◽  
Chromosome 21 ◽  
Neural Dynamics ◽  
Human Chromosome 21 ◽  
Chromosomal Disorder ◽  
Reduced Frequency ◽  
High Gamma

SummaryAltered neural dynamics in medial prefrontal cortex (mPFC) and hippocampus may contribute to cognitive impairments in the complex chromosomal disorder, Down Syndrome (DS). Here, we demonstrate non-overlapping behavioural differences associated with distinct abnormalities in hippocampal and mPFC electrophysiology during a canonical spatial memory task in three partially trisomic mouse models of DS (Dp1Tyb, Dp10Yey, Dp17Yey) that together cover all regions of homology with human chromosome 21 (Hsa21). Dp1Tyb mice showed slower decision-making (unrelated to the gene dose of DYRK1A, which has been implicated in DS cognitive dysfunction) and altered theta dynamics (reduced frequency, increased hippocampal-mPFC coherence, increased modulation of hippocampal high gamma); Dp10Yey mice showed impaired alternation performance and reduced theta modulation of hippocampal low gamma; while Dp17Yey mice were no different from wildtype mice. These results link specific hippocampal and mPFC circuit dysfunctions to cognitive deficits in DS models and, importantly, map them to discrete regions of Hsa21.

scholarly journals Comprehensive phenotypic analysis of the Dp1Tyb mouse strain reveals a broad range of down syndrome-related phenotypes

2021 ◽  
Author(s):  
Eva Lana-Elola ◽  
Heather Cater ◽  
Sheona Watson-Scales ◽  
Simon Greenaway ◽  
Jennifer Müller-Winkler ◽  
...  
Keyword(s):  
Down Syndrome ◽  
Cognitive Deficits ◽  
Trisomy 21 ◽  
Heart Defects ◽  
Chromosome 21 ◽  
Phenotypic Analysis ◽  
Extra Copy ◽  
Human Chromosome 21 ◽  
Complex Phenotypes ◽  
Physiological Systems

Down syndrome (DS), trisomy 21, results in many complex phenotypes including cognitive deficits, heart defects and craniofacial alterations. Phenotypes arise from an extra copy of human chromosome 21 (Hsa21) genes. However, these dosage-sensitive causative genes remain unknown. Animal models enable identification of genes and pathological mechanisms. The Dp1Tyb mouse model of DS has an extra copy of 63% of Hsa21-orthologous mouse genes. In order to establish if this model recapitulates DS phenotypes, we comprehensively phenotyped Dp1Tyb mice using 28 tests of different physiological systems and found that 468 out of 1800 parameters were significantly altered. We show that Dp1Tyb mice have wide-ranging DS-like phenotypes including aberrant erythropoiesis and megakaryopoiesis, reduced bone density, craniofacial changes, altered cardiac function, a pre-diabetic state and deficits in memory, locomotion, hearing and sleep. Thus, Dp1Tyb mice are an excellent model for investigating complex DS phenotype-genotype relationships for this common disorder.

scholarly journals Novel DYRK1A Inhibitor Rescues Learning and Memory Deficits in a Mouse Model of Down Syndrome

2021 ◽  
Vol 14 (11) ◽  
pp. 1170
Author(s):  
Wenche Stensen ◽  
Ulli Rothweiler ◽  
Richard Alan Engh ◽  
Melissa R. Stasko ◽  
Ilya Bederman ◽  
...  
Keyword(s):  
Down Syndrome ◽  
Cognitive Deficits ◽  
Genetic Disorder ◽  
Treatment Options ◽  
Chromosome 21 ◽  
The Novel ◽  
Behavioral Challenges ◽  
Early Onset Alzheimer’S Disease ◽  
Encoding Gene ◽  
Complex Genetic Disorder

Down syndrome (DS) is a complex genetic disorder associated with substantial physical, cognitive, and behavioral challenges. Due to better treatment options for the physical co-morbidities of DS, the life expectancy of individuals with DS is beginning to approach that of the general population. However, the cognitive deficits seen in individuals with DS still cannot be addressed pharmacologically. In young individuals with DS, the level of intellectual disability varies from mild to severe, but cognitive ability generally decreases with increasing age, and all individuals with DS have early onset Alzheimer’s disease (AD) pathology by the age of 40. The present study introduces a novel inhibitor for the protein kinase DYRK1A, a key controlling kinase whose encoding gene is located on chromosome 21. The novel inhibitor is well characterized for use in mouse models and thus represents a valuable tool compound for further DYRK1A research.

scholarly journals Antioxidant enzymes and fatty acid status in erythrocytes of Down syndrome patients

1998 ◽  
Vol 44 (5) ◽  
pp. 924-929 ◽  
Author(s):  
M-Cruz Pastor ◽  
Cristina Sierra ◽  
María Doladé ◽  
Elisabet Navarro ◽  
Nuria Brandi ◽  
...  
Keyword(s):  
Oxidative Stress ◽  
Fatty Acids ◽  
Down Syndrome ◽  
Catalytic Activity ◽  
Antioxidant Enzymes ◽  
Chromosome 21 ◽  
Control Group ◽  
Acid Status ◽  
Antioxidant Mechanisms ◽  
Long Chain

Abstract The excess of genetic information in patients with Down syndrome (DS) produces an increase in the catalytic activity of superoxide dismutase (SOD1), an antioxidant enzyme coded on chromosome 21. It has been suggested that an increase in oxidative stress in DS patients may cause adverse effects in the cell membranes through the oxidation of polyunsaturated fatty acids (PUFAs). The aim of this study was to evaluate the cellular antioxidant system by determining the catalytic activity of the SOD1, glutathione peroxidase (GPx), catalase (CAT), and glutathione reductase (GR) enzymes and the concentrations of α-tocopherol in red blood cells (RBCs) in a group of 72 DS patients. The profile of fatty acids in the phospholipids of RBC membranes was also evaluated. The activity of the erythrocyte antioxidant enzymes is significantly higher in the DS group than in the control group (SOD1, 635 ± 70 U/g Hb vs 476 ± 67 U/g Hb; CAT, 1843 ± 250 U/g Hb vs 1482 ± 250 U/g Hb; GPx, 23.2 ± 5.3 U/g Hb vs 21.5 ± 3.6 U/g Hb; and GR, 9.32 ± 1.4 U/g Hb vs 6.9 ± 1.3 U/g Hb, respectively). No differences were observed in RBC α-tocopherol concentrations between the two groups studied. Long-chain n6 PUFA (C20:3n6, C20:4n6) concentrations were increased in DS patients, suggesting enhanced Δ-6-desaturase activity. The long-chain n3 PUFA (docosahexenoic acid) does not appear to be affected by increased oxidative stress, probably because of the existence of compensatory antioxidant mechanisms.

scholarly journals Mouse Models of Down Syndrome as a Tool to Unravel the Causes of Mental Disabilities

2012 ◽  
Vol 2012 ◽  
pp. 1-26 ◽  
Author(s):  
Noemí Rueda ◽  
Jesús Flórez ◽  
Carmen Martínez-Cué
Keyword(s):  
Clinical Trials ◽  
Down Syndrome ◽  
Mouse Models ◽  
Later Life ◽  
Neural Mechanisms ◽  
Mental Disability ◽  
Life Stages ◽  
Mental Disabilities ◽  
Ts65dn Mouse ◽  
Neurobiological Substrates

Down syndrome (DS) is the most common genetic cause of mental disability. Based on the homology of Hsa21 and the murine chromosomes Mmu16, Mmu17 and Mmu10, several mouse models of DS have been developed. The most commonly used model, the Ts65Dn mouse, has been widely used to investigate the neural mechanisms underlying the mental disabilities seen in DS individuals. A wide array of neuromorphological alterations appears to compromise cognitive performance in trisomic mice. Enhanced inhibition due to alterations in GABAA-mediated transmission and disturbances in the glutamatergic, noradrenergic and cholinergic systems, among others, has also been demonstrated. DS cognitive dysfunction caused by neurodevelopmental alterations is worsened in later life stages by neurodegenerative processes. A number of pharmacological therapies have been shown to partially restore morphological anomalies concomitantly with cognition in these mice. In conclusion, the use of mouse models is enormously effective in the study of the neurobiological substrates of mental disabilities in DS and in the testing of therapies that rescue these alterations. These studies provide the basis for developing clinical trials in DS individuals and sustain the hope that some of these drugs will be useful in rescuing mental disabilities in DS individuals.

scholarly journals Comprehensive phenotypic analysis of the Dp1Tyb mouse strain reveals a broad range of Down Syndrome-related phenotypes

2021 ◽  
Author(s):  
Eva Lana-Elola ◽  
Heather Cater ◽  
Sheona Watson-Scales ◽  
Simon Greenaway ◽  
Jennifer Müller-Winkler ◽  
...  
Keyword(s):  
Down Syndrome ◽  
Bone Density ◽  
Cognitive Deficits ◽  
Trisomy 21 ◽  
Heart Defects ◽  
Chromosome 21 ◽  
Phenotypic Analysis ◽  
Extra Copy ◽  
Human Chromosome 21 ◽  
Complex Phenotypes

AbstractDown syndrome (DS), trisomy 21, results in many complex phenotypes including cognitive deficits, heart defects and craniofacial alterations. Phenotypes arise from an extra copy of human chromosome 21 (Hsa21) genes. However, causative genes remain mostly unknown. Animal models enable identification of these genes and pathological mechanisms. The Dp1Tyb mouse model of DS has an extra copy of 63% of Hsa21-orthologous mouse genes. Here, we comprehensively phenotype Dp1Tyb mice and find wide-ranging DS-like phenotypes including aberrant megakaryopoiesis, reduced bone density, and deficits in memory, locomotion, hearing and sleep. Thus, Dp1Tyb mice are an excellent model for studies of many complex DS phenotypes.

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