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Long-lasting protection: Nerve agents are the most toxic and lethal warfare chemical compounds. The toxic effect is due to inhibition of the acetylcholinesterase enzymes. Current antidotes prevent death but are ineffective against complications including brain damage and behavioral impairments. To prevent these deleterious consequences, now, Betapudi et al. developed a prophylactic gene therapy delivering the gene coding for a variant of the nerve agent scavenger paraoxonase 1 (PON1). When injected systemically in mice, the treatment exerted long-lasting protection against different types of nerve agents without signs of toxicity. The results suggest that gene therapy might be a viable option as prophylactic treatment in subjects at risk of exposure to nerve agents such as military personnel in war zones. Chemical warfare nerve agents are organophosphorus chemical compounds that induce cholinergic crisis, leaving little or no time for medical intervention to prevent death. The current chemical treatment regimen may prevent death but does not prevent postexposure complications such as brain damage and permanent behavioral abnormalities. In the present study, we have demonstrated an adeno-associated virus 8 (AAV8)–mediated paraoxonase 1 variant IF-11 (PON1-IF11) gene therapy that offers asymptomatic prophylactic protection to mice against multiple lethal doses of G-type chemical warfare nerve agents, namely, tabun, sarin, cyclosarin, and soman, for up to 5 months in mice. A single injection of liver-specific adeno-associated viral particles loaded with PON1-IF11 gene resulted in expression and secretion of recombinant PON1-IF11 in milligram quantities, which has the catalytic power to break down G-type chemical warfare nerve agents into biologically inactive products in vitro and in vivo in rodents. Mice containing milligram concentrations of recombinant PON1-IF11 in their blood displayed no clinical signs of toxicity, as judged by their hematological parameters and serum chemistry profiles. Our study unfolds avenues to develop a one-time application of gene therapy to express a near-natural and circulating therapeutic PON1-IF11 protein that can potentially protect humans against G-type chemical warfare nerve agents for several weeks to months. [ABSTRACT FROM AUTHOR]

The human genetic code encrypted in thousands of genes holds the secret for synthesis of proteins that drive all biological processes necessary for normal life and death. Though the genetic ciphering remains unchanged through generations, some genes get disrupted, deleted and or mutated, manifesting diseases, and or disorders. Current treatment options—chemotherapy, protein therapy, radiotherapy, and surgery available for no more than 500 diseases—neither cure nor prevent genetic errors but often cause many side effects. However, gene therapy, colloquially called "living drug," provides a one-time treatment option by rewriting or fixing errors in the natural genetic ciphering. Since gene therapy is predominantly a viral vector-based medicine, it has met with a fair bit of skepticism from both the science fraternity and patients. Now, thanks to advancements in gene editing and recombinant viral vector development, the interest of clinicians and pharmaceutical industries has been rekindled. With the advent of more than 12 different gene therapy drugs for curing cancer, blindness, immune, and neuronal disorders, this emerging experimental medicine has yet again come in the limelight. The present review article delves into the popular viral vectors used in gene therapy, advances, challenges, and perspectives. [ABSTRACT FROM AUTHOR]

GABAA receptors form Cl- permeable channels that mediate the majority of fast synaptic inhibition in the brain. The K+/Cl- cotransporter KCC2 is the main mechanism by which neurons establish low intracellular Cl- levels, which is thought to enable GABAergic inhibitory control of neuronal activity. However, the widely used KCC2 inhibitor furosemide is nonselective with antiseizure efficacy in slices and in vivo, leading to a conflicting scheme of how KCC2 influences GABAergic control of neuronal synchronization. Here we used the selective KCC2 inhibitor VU0463271 [N-cyclopropyl-N-(4-methyl-2-thiazolyl)-2-[(6-phenyl-3-pyridazinyl)thio]acetamide] to investigate the influence of KCC2 function. Application of VU0463271 caused a reversible depolarizing shift in EGABA values and increased spiking of cultured hippocampal neurons. Application of VU0463271 to mouse hippocampal slices under low-Mg2+ conditions induced unremitting recurrent epileptiform discharges. Finally, microinfusion of VU0463271 alone directly into the mouse dorsal hippocampus rapidly caused epileptiform discharges. Our findings indicated that KCC2 function was a critical inhibitory factor ex vivo and in vivo. [ABSTRACT FROM AUTHOR]

The KCC2 cotransporter establishes the low neuronal Cl− levels required for GABAA and glycine (Gly) receptor-mediated inhibition, and KCC2 deficiency in model organisms results in network hyperexcitability. However, no mutations in KCC2 have been documented in human disease. Here, we report two non-synonymous functional variants in human KCC2, R952H and R1049C, exhibiting clear statistical association with idiopathic generalized epilepsy ( IGE). These variants reside in conserved residues in the KCC2 cytoplasmic C-terminus, exhibit significantly impaired Cl−-extrusion capacities resulting in less hyperpolarized Gly equilibrium potentials ( EGly), and impair KCC2 stimulatory phosphorylation at serine 940, a key regulatory site. These data describe a novel KCC2 variant significantly associated with a human disease and suggest genetically encoded impairment of KCC2 functional regulation may be a risk factor for the development of human IGE. [ABSTRACT FROM AUTHOR]

Benzodiazepines potentiate γ-aminobutyric acid type A receptor (GABAAR) activity and are widely prescribed to treat anxiety, insomnia, and seizure disorders. Unfortunately, clinical use of benzodiazepines (BZs) is severely limited by tolerance. The mechanisms leading to BZ tolerance are unknown. BZs bind at the interface between an a and γ subunit of GABAARs, preferentially enhancing synaptic receptors largely composed of α(1-3, 5), β3, and γ2 subunits. Using confocal imaging and patch-clamp approaches, we show that treatment with the BZ flurazepam decreases GABAAR surface levels and the efficacy of neuronal inhibition in hippocampal neurons. A dramatic decrease in surface and total levels of α2 subunit-containing GABAARs occurred within 24 h of flurazepam treatment, whereas GABAARs incorporating α1 subunits showed little alteration. The GABAAR surface depletion could be reversed by treatment with the BZ antagonist Ro 15-1788. Coincident with decreased GABAAR surface levels, flurazepam treatment reduced miniature inhibitory postsynaptic current amplitude, which returned to control levels with acute Ro 15-1788 treatment. GABAAR endocytosis and insertion rates were unchanged by flurazepam treatment. Treatment with leupeptin restored flurazepam lowered receptor surface levels, strongly suggesting that flurazepam increases lysosomal degradation of GABAARs. Together, these data suggest that flurazepam exposure enhances degradation of α2 subunit-containing GABAARs after their removal from the plasma membrane, leading to a reduction in inhibitory synapse size and number along with a decrease in the efficacy of synaptic inhibition. These reported subtype-specific changes in GABAAR trafficking provide significant mechanistic insight into the initial neuroadaptive responses occurring with BZ treatment. [ABSTRACT FROM AUTHOR]