Genome editing technologies and their potential to treat neurologic disease

DNA aptamers that modulate biological activity of model neurons

There is an urgent need for agents that promote health and regeneration of cells and tissues, specifically to treat diseases of the aging nervous system. Age-associated nervous system degeneration and various diseases are driven by many different biochemical stresses, often making it difficult to target any one disease cause. Our laboratory has previously identified DNA aptamers with apparent regenerative properties in murine models of multiple sclerosis by selecting aptamers that bind oligodendrocyte membrane preparations. Here, we selected from vast libraries of molecules (∼1014 unique DNAs) those with the ability to bind cultured human SH-SY5Y neuroblastoma cells as a neuronal model, followed by screening for aptamers capable of eliciting biological responses, with validation of binding in differentiated SH-SY5Y, human induced pluripotent stem cell (iPSC)-derived sensory neurons, and human embryonic stem cell (hESC)-derived cortical neurons. This demonstrates a proof-of-concept workflow to identify biologically active aptamers by cycles of cell selection.

A journey through the history of Neurogenetics

Since the late 19th century, when several inherited neurological disorders were described, the close relationship between Neurology and heredity were well documented by several authors in a pre-genetic era. The term Neurogenetics came to integrate two large sciences and clinical practices: Neurology and Genetics. Neurogenetics is the emerging field that studies the correlation between genetic code and the development and function of the nervous system, including behavioral traits, personality and neurological diseases. In this historical note, a timeline shows the main events and contributors since the first reports of neurogenetic diseases until the current days. In the recent years, neurologists are experiencing much broader use of new genetic diagnosis techniques in clinical practice. Thus, new challenges are arising in diagnostic approach, ethical considerations, and therapeutic options. This article aims to summarize the main historical hallmarks of Neurogenetics, from the pre-DNA era to the present, and the future directions of the field.

Protein and mRNA Delivery Enabled by Cholesteryl-Based Biodegradable Lipidoid Nanoparticles

Developing safe and efficient delivery systems for therapeutic biomacromolecules is a long-standing challenge. Herein, we report a newly developed combinatorial library of cholesteryl-based disulfide bond-containing biodegradable cationic lipidoid nanoparticles. We have identified a subset of this library which is effective for protein and mRNA delivery in vitro and in vivo. These lipidoids showed comparable transfection efficacies but much lower cytotoxicities compared to the Lpf2k in vitro. In vivo studies in adult mice demonstrated the successful delivery of genome engineering protein and mRNA molecules in the skeletal muscle (via intramuscular injection), lung and spleen (via intravenous injection), and brain (via lateral ventricle infusion).

Amyotrophic Lateral Sclerosis: An Update for 2018

Amyotrophic lateral sclerosis (ALS) is a neurodegenerative disease affecting motor neurons and other neuronal cells, leading to severe disability and eventually death from ventilatory failure. It has a prevalence of 5 in 100,000, with an incidence of 1.7 per 100,000, reflecting short average survival. The pathogenesis is incompletely understood, but defects of RNA processing and protein clearance may be fundamental. Repeat expansions in the chromosome 9 open reading frame 72 gene (C9orf72) are the most common known genetic cause of ALS and are seen in approximately 40% of patients with a family history and approximately 10% of those without. No environmental risk factors are proved to be causative, but many have been proposed, including military service. The diagnosis of ALS rests on a history of painless progressive weakness coupled with examination findings of upper and lower motor dysfunction. No diagnostic test is yet available, but electromyography and genetic tests can support the diagnosis. Care for patients is best provided by a multidisciplinary team, and most interventions are directed at managing symptoms. Two medications with modest benefits have Food and Drug Administration approval for the treatment of ALS: riluzole, a glutamate receptor antagonist, and, new in 2017, edaravone, a free radical scavenger. Many other encouraging treatment strategies are being explored in clinical trials for ALS; herein we review stem cell and antisense oligonucleotide gene therapies.