Manufacturing DNA in yields higher-fidelity DNA than enzymatic synthesis.

Biotechnologies such as gene therapy have brought DNA vectors to the forefront of pharmaceuticals. The quality of starting material plays a pivotal role in determining final product quality. Here, we examined the fidelity of DNA replication using enzymatic methods () compared to plasmid DNA produced in .

A natural history study to track brain and spinal cord changes in individuals with Friedreich's ataxia: TRACK-FA study protocol.

Introduction: Drug development for neurodegenerative diseases such as Friedreich's ataxia (FRDA) is limited by a lack of validated, sensitive biomarkers of pharmacodynamic response in affected tissue and disease progression. Studies employing neuroimaging measures to track FRDA have thus far been limited by their small sample sizes and limited follow up. TRACK-FA, a longitudinal, multi-site, and multi-modal neuroimaging natural history study, aims to address these shortcomings by enabling better understanding of underlying pathology and identifying sensitive, clinical trial ready, neuroimaging biomarkers for FRDA.

The Vasopressin 1a Receptor Antagonist SRX246 Reduces Aggressive Behavior in Huntington's Disease.

SRX246, an orally available CNS penetrant vasopressin (VP) V1a receptor antagonist, was studied in Huntington's disease (HD) patients with irritability and aggressive behavior in the exploratory phase 2 trial, Safety, Tolerability, and Activity of SRX246 in Irritable HD patients (STAIR). This was a dose-escalation study; subjects received final doses of 120 mg BID, 160 mg BID, or placebo. The compound was safe and well tolerated.

Utility of the Huntington's Disease Prognostic Index Score for a Perimanifest Clinical Trial.

Background: Subtle neurodegenerative motor and cognitive impairments accumulate over a prodromal period several years before clinical diagnosis of Huntington's disease (HD). The inclusion of prodromal individuals in therapeutic trials would facilitate testing of therapies early in the disease course and the development of treatments intended to prevent or delay disability.

Objectives: We evaluate the normalized prognostic index (PIN) score as a tool to select participants for a perimanifest trial.

Impaired Cerebrovascular Reactivity in Huntington's Disease.

There is increasing evidence that impairments of cerebrovascular function and/or abnormalities of the cerebral vasculature might contribute to early neuronal cell loss in Huntington's disease (HD). Studies in both healthy individuals as well as in patients with other neurodegenerative disorders have used an exogenous carbon dioxide (CO) challenge in conjunction with functional magnetic resonance imaging (fMRI) to assess regional cerebrovascular reactivity (CVR). In this study, we explored potential impairments of CVR in HD.

Engineered Type Six Secretion Systems Deliver Active Exogenous Effectors and Cre Recombinase.

Genetic editing has revolutionized biotechnology, but delivery of endonuclease genes as DNA can lead to aberrant integration or overexpression, leading to off-target effects. Here, we develop a mechanism to deliver Cre recombinase as a protein by engineering the bacterial type six secretion system (T6SS). Using multiple T6SS fusion proteins, Aeromonas dhakensis or attenuated Vibrio cholerae donor strains, and a gain-of-function cassette for detecting Cre recombination, we demonstrate successful delivery of active Cre directly into recipient cells.

Sensing of intracellular Hcp levels controls T6SS expression in .

The type 6 secretion system (T6SS) is a bacterial weapon broadly distributed in gram-negative bacteria and used to kill competitors and predators. Featuring a long and double-tubular structure, this molecular machine is energetically costly to produce and thus is likely subject to diverse regulation strategies that are largely ill defined. In this study, we report a quantity-sensing control of the T6SS that down-regulates the expression of secreted components when they accumulate in the cytosol due to T6SS inactivation.

A stress-induced block in dicarboxylate uptake and utilization in .

Bacteria have evolved to sense and respond to their environment by altering gene expression and metabolism to promote growth and survival. In this work we demonstrate that displays an extensive (>30 hour) lag in growth when subcultured into media where dicarboxylates such as succinate are the sole carbon source. This growth lag is regulated in part by RpoS, the RssB anti-adaptor IraP, translation elongation factor P, and to a lesser degree the stringent response.

Safety and Tolerability of SRX246, a Vasopressin 1a Antagonist, in Irritable Huntington's Disease Patients-A Randomized Phase 2 Clinical Trial.

SRX246 is a vasopressin (AVP) 1a receptor antagonist that crosses the blood-brain barrier. It reduced impulsive aggression, fear, depression and anxiety in animal models, blocked the actions of intranasal AVP on aggression/fear circuits in an experimental medicine fMRI study and demonstrated excellent safety in Phase 1 multiple-ascending dose clinical trials. The present study was a 3-arm, multicenter, randomized, placebo-controlled, double-blind, 12-week, dose escalation study of SRX246 in early symptomatic Huntington's disease (HD) patients with irritability.

Association of Dilated Perivascular Spaces and Disease Severity in Patients With Huntington Disease.

Objective: To quantify the percent volume of dilated perivascular space (PVS) in the subcortical forebrain in patients with early Huntington disease (HD) and to explore the relationship between PVS and disease severity.

Methods: MRI scans were performed on 25 patients with HD and 23 healthy age-matched controls at Massachusetts General Hospital. The imaging data were analyzed with a novel algorithm to determine regional PVS volume.

Defending against the Type Six Secretion System: beyond Immunity Genes.

The bacterial type six secretion system (T6SS) delivers toxic effector proteins into neighboring cells, but bacteria must protect themselves against their own T6SS. Immunity genes are the best-characterized defenses, protecting against specific cognate effectors. However, the prevalence of the T6SS and the coexistence of species with heterologous T6SSs suggest evolutionary pressure selecting for additional defenses against it.

The LysR Family Regulator RipR Activates the SPI-13-Encoded Itaconate Degradation Cluster.

Itaconate is a dicarboxylic acid that inhibits the isocitrate lyase enzyme of the bacterial glyoxylate shunt. Activated macrophages have been shown to produce itaconate, suggesting that these immune cells may employ this metabolite as a weapon against invading bacteria. Here, we demonstrate that , itaconate can exhibit bactericidal effects under acidic conditions similar to the pH of a macrophage phagosome.

Clinical Outcomes and Selection Criteria for Prodromal Huntington's Disease Trials.

Background: Huntington's disease (HD) develops in individuals with extended cytosine-adenine-guanine (CAG) repeats within the huntingtin (HTT) gene, causing neurodegeneration and progressive motor and cognitive symptoms. The inclusion of mutant HTT carriers in whom overt symptoms are not yet fully manifest in therapeutic trials would enable the development of treatments that delay or halt the accumulation of significant disability.

Objectives: The present analyses assess whether screening prediagnosis (preHD) individuals based on a normalized prognostic index (PIN) score would enable the selection of prodromal preHD subjects in whom longitudinal changes in established outcome measures might provide robust signals.

Differential Cellular Response to Translocated Toxic Effectors and Physical Penetration by the Type VI Secretion System.

The type VI secretion system (T6SS) is a lethal microbial weapon that injects a large needle-like structure carrying toxic effectors into recipient cells through physical penetration. How recipients respond to physical force and effectors remains elusive. Here, we use a series of effector mutants of Vibrio cholerae to determine how T6SS elicits response in Pseudomonas aeruginosa and Escherichia coli.

Envelope stress responses defend against type six secretion system attacks independently of immunity proteins.

The arms race among microorganisms is a key driver in the evolution of not only the weapons but also defence mechanisms. Many Gram-negative bacteria use the type six secretion system (T6SS) to deliver toxic effectors directly into neighbouring cells. Defence against effectors requires cognate immunity proteins.

Double Tubular Contractile Structure of the Type VI Secretion System Displays Striking Flexibility and Elasticity.

Antimicrobial treatment can induce many bacterial pathogens to enter a cell wall-deficient state that contributes to persistent infections. The effect of this physiological state on the assembly of transenvelope-anchored organelles is not well understood. The type VI secretion system (T6SS) is a widespread molecular weapon for interspecies interactions and virulence, comprising a long double tubular structure and a transenvelope/baseplate complex.

The current state of biomarker research for Friedreich's ataxia: a report from the 2018 FARA biomarker meeting.

The 2018 FARA Biomarker Meeting highlighted the current state of development of biomarkers for Friedreich's ataxia. A mass spectroscopy assay to sensitively measure mature frataxin (reduction of which is the root cause of disease) is being developed. Biomarkers to monitor neurological disease progression include imaging, electrophysiological measures and measures of nerve function, which may be measured either in serum and/or through imaging-based technologies.

Electrocardiogram Abnormalities Suggest Aberrant Cardiac Conduction in Huntington's Disease.

Background: There is increasing evidence that the effects of Huntington's disease (HD) extend beyond the central nervous system. In particular, significant cardiac dysfunction has been described in transgenic mouse models and suggested in symptomatic patients, in whom cardiac involvement could provide an independent risk for sudden cardiac death.

Methods: Standard 12-lead electrocardiograms (ECGs) obtained at screening from 590 early symptomatic (Stage 1 and 2) HD patients participating in a multi-site Phase III study were analyzed.

The CREST-E study of creatine for Huntington disease: A randomized controlled trial.

Objective: To investigate whether creatine administration could slow progressive functional decline in adults with early symptoms of Huntington disease.

Methods: We conducted a multicenter, randomized, double-blind, placebo-controlled study of up to 40 g daily of creatine monohydrate in participants with stage I and II HD treated for up to 48 months. The primary outcome measure was the rate of change in total functional capacity (TFC) between baseline and end of follow-up.

KEAP1-modifying small molecule reveals muted NRF2 signaling responses in neural stem cells from Huntington's disease patients.

The activity of the transcription factor nuclear factor-erythroid 2 p45-derived factor 2 (NRF2) is orchestrated and amplified through enhanced transcription of antioxidant and antiinflammatory target genes. The present study has characterized a triazole-containing inducer of NRF2 and elucidated the mechanism by which this molecule activates NRF2 signaling. In a highly selective manner, the compound covalently modifies a critical stress-sensor cysteine (C151) of the E3 ligase substrate adaptor protein Kelch-like ECH-associated protein 1 (KEAP1), the primary negative regulator of NRF2.