Metallothioneins are neuroprotective agents in lysosomal storage disorders.

OBJECTIVE: Lysosomal storage disorders (LSDs) are a broad class of inherited metabolic diseases caused by the defective activity of lysosomal enzymes. Central nervous system (CNS) manifestations are present in roughly 50% of LSD patients and represent an unmet medical need for them. We explored the therapeutic potential of metallothioneins (MTs), a newly identified family of proteins with reported neuroprotective roles, in the murine models of two LSDs with CNS involvement. METHODS: MT-1 overexpressing transgenic mice (MTtg) were crossed with the murine models of Batten and Krabbe diseases. Changes in the survival and manifestations of the disease in the MTtg setting were assessed. In addition, we analyzed the therapeutic effects of MT-1 CNS gene delivery in one of these LSD models. RESULTS: Constitutive expression of MT-1 exerted favorable phenotypic effects in both LSD models. MT-LSD mice showed a 5% to 10% increase in survival and slower disease progression as compared to not-transgenic LSD mice. Rescue of Purkinje cells from degeneration and apoptosis was also observed in the MT-LSD models. This phenotypic amelioration was accompanied by a modulation of the disease-associated activated inflammatory microglia phenotype, and by a reduction of oxidative stress. Importantly, for the clinical translation of our findings, the very same effects were obtained when MTs were delivered to brains by systemic AAV gene transfer. INTERPRETATION: MTs can be considered novel therapeutic agents (and targets) in LSDs and potentiate the effects of approaches aiming at correction of the disease-causing enzyme deficiency in the CNS. Ann Neurol 2018;83:418-432 Ann Neurol 2018;83:418-432.

Nanoscale structure-activity relationships, mode of action, and biocompatibility of gold nanoparticle antibiotics.

The emergence of resistance to multiple antimicrobial agents by pathogenic bacteria has become a significant global public health threat. Multi-drug-resistant (MDR) Gram-negative bacteria have become particularly problematic, as no new classes of small-molecule antibiotics for Gram-negative bacteria have emerged in over two decades. We have developed a combinatorial screening process for identifying mixed ligand monolayer/gold nanoparticle conjugates (2.4 nm diameter) with antibiotic activity. The method previously led to the discovery of several conjugates with potent activity against the Gram-negative bacterium Escherichia coli. Here we show that these conjugates are also active against MDR E. coli and MDR Klebsiella pneumoniae. Moreover, we have shown that resistance to these nanoparticles develops significantly more slowly than to a commercial small-molecule drug. These results, combined with their relatively low toxicity to mammalian cells and biocompatibility in vivo, suggest that gold nanoparticles may be viable new candidates for the treatment of MDR Gram-negative bacterial infections.

Systemic Delivery of AAVB1-GAA Clears Glycogen and Prolongs Survival in a Mouse Model of Pompe Disease.

Pompe disease is an autosomal recessive glycogen storage disorder caused by deficiency of the lysosomal enzyme acid alpha-glucosidase (GAA). GAA deficiency results in systemic lysosomal glycogen accumulation and cellular disruption in muscle and the central nervous system (CNS). Adeno-associated virus (AAV) gene therapy is ideal for Pompe disease, since a single systemic injection may correct both muscle and CNS pathologies. Using the Pompe mouse (B6;129-GaaTm1Rabn/J), this study sought to explore if AAVB1, a newly engineered vector with a high affinity for muscle and CNS, reduces systemic weakness and improves survival in adult mice. Three-month-old Gaa-/- animals were injected with either AAVB1 or AAV9 vectors expressing GAA and tissues were harvested 6 months later. Both AAV vectors prolonged survival. AAVB1-treated animals had a robust weight gain compared to the AAV9-treated group. Vector genome levels, GAA enzyme activity, and histological analysis indicated that both vectors transduced the heart efficiently, leading to glycogen clearance, and transduced the diaphragm and CNS at comparable levels. AAVB1-treated mice had higher GAA activity and greater glycogen clearance in the tongue. Finally, AAVB1-treated animals showed improved respiratory function comparable to wild-type animals. In conclusion, AAVB1-GAA offers a promising therapeutic option for the treatment of muscle and CNS in Pompe disease.

Thiol-modified gold nanoparticles for the inhibition of Mycobacterium smegmatis.

Antimicrobial drug discovery has slowed considerably over the last few decades. One major cause for concern is the lack of innovative approaches to treat infections caused by mycobacteria such as TB. Herein we demonstrate that our Small Molecule Variable Ligand Display (SMLVD) method for nanoparticle antibiotic discovery can be expanded around a ligand feed ratio parameter space to identify gold nanoparticle conjugates that are potent inhibitors of mycobacteria growth, with our most potent inhibitor able to reduce growth by five orders of magnitude at 8 µM.