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Frontiers: Down syndrome (DS), also known as trisomy 21, is a genetic disorder caused by triplication of Chromosome 21

Gene triplication may compromise different body functions but invariably impairs intellectual abilities starting from infancy. Moreover, after the fourth decade of life people with DS are likely to develop Alzheimer’s disease. Neurogenesis impairment during fetal life stages and dendritic pathology emerging in early infancy are thought to be key determinants of alterations in brain functioning in DS. Although the progressive improvement in medical care has led to a notable increase in life expectancy for people with DS, there are currently no treatments for intellectual disability. Increasing evidence in mouse models of DS reveals that pharmacological interventions in the embryonic and neonatal periods may greatly benefit brain development and cognitive performance. The most striking results have been obtained with pharmacotherapies during embryonic life stages, indicating that it is possible to pharmacologically rescue the severe neurodevelopmental defects linked to the trisomic condition. These findings provide hope that similar benefits may be possible for people with DS. This review summarizes current knowledge regarding (i) the scope and timeline of neurogenesis (and dendritic) alterations in DS, in order to delineate suitable windows for treatment; (ii) the role of triplicated genes that are most likely to be the key determinants of these alterations, in order to highlight possible therapeutic targets; and (iii) prenatal and neonatal treatments that have proved to be effective in mouse models, in order to rationalize the choice of treatment for human application. Based on this body of evidence we will discuss prospects and challenges for fetal therapy in individuals with DS as a potential means of drastically counteracting the deleterious effects of gene triplication.

Down syndrome (DS) is a relatively high-incidence pathology (∼1 in every 800–1,000 live births; see Antonarakis et al., 2020; Hughes-McCormack et al., 2020) caused by triplication of Hsa21. Increased expression of Hsa21 genes (and genes on other chromosomes) impairs development and functions of various organs, including the brain (Bull, 2020). While some disorders may not be present in all individuals with DS, intellectual disability (ID) is the invariable hallmark of DS (Zigman, 2013; Ballard et al., 2016; Lott and Head, 2019). ID scores range from moderately (IQ of 50–70) to severely (IQ of 20–35; Bull, 2020) affected; even in its milder form, intellectual performance may compromise the ability to live independently. ID is already detectable in children with DS, especially regarding language, memory, and adaptive behavior, and is exacerbated with age (Godfrey and Lee, 2020).

Plasticity as a therapeutic target for improving cognition and behavior in Down syndrome

Early intervention and environmental optimization have been central to management of Down syndrome (DS) and much of current treatment is still focused in strategies that involve early education plans. This approach has provided significant improvements for Down syndrome but it is not providing a full success. The discovery of an increasing number of genes and molecular pathways linked to intellectual disability and involving a range of synaptic and plasticity-related mechanisms has open new treatment opportunities that focus on targeted treatments boosting neural plasticity. We here discuss some of these approaches, focusing on the effects of environmental enrichment and on the discovery of pharmacological therapies showing beneficial effects even in some clinical trials in adult individuals with Down syndrome. Targeting plasticity impairments in DS is thus a promising strategy to promote cellular mechanisms involved in learning and memory within key cognitive brain region and could lead to improved connectivity.

Keywords: EGCG; Environ-mimetic drugs; Environmental enrichments; Epigenetics; Neuronal plasticity.

© 2020 Elsevier B.V. All rights reserved.

A common food compound may hold the key to shutting down leaky gut damage

When the intestinal lining breaks down, harmful gut bacterial antigens can slip into the bloodstream alongside nutrients. This breach in the gut’s protective barrier, known as “leaky gut,” is more than a digestive issue—it’s a sign of inflammatory bowel disease (IBD) and has been increasingly linked to a number of chronic conditions.

A team of researchers working in the lab of UNLV cellular biologist Prasun Guha has uncovered a key mechanism underlying leaky gut and identified a promising and natural way to repair it. And a potential solution is already in many of the foods we eat every day.

In a study published in the journal Nature Communications, the team shares how phytic acid (or InsP6), a natural compound found in whole grains, beans, lentils, nuts, and seeds, plays an important role in maintaining the integrity of the intestinal barrier.

Engineered stem cells reverse new-onset type 1 diabetes in mice

A group of researchers at the Medical University of South Carolina (MUSC) has recently developed a new stem cell therapy with a remarkable ability to reverse new-onset type 1 diabetes (T1D) in a mouse model of the disease. The work is published in the journal Molecular Therapy.

Hongjun Wang, Ph.D., associate director of the South Carolina Clinical & Translational Research (SCTR) Institute Pilot Program and co-scientific director for the Center for Cellular Therapy, led the team. Co-first authors Hua Wei, Ph.D.; Judong Kim, Ph.D.; and Wenyu Gou, Ph.D., together with other collaborators, conducted most of the work to establish these findings.

This research study marks a pivotal move away from the current standard of managing blood sugar through multiple daily insulin injections and toward a lasting way to reprogram the immune system itself. For the millions of people currently living with T1D, this could be a game-changer.

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