Broad gene expression throughout the mouse and marmoset brain after intravenous delivery of engineered AAV capsids

Genetic intervention is increasingly explored as a therapeutic option for debilitating disorders of the central nervous system. The safety and efficacy of gene therapies relies upon expressing a transgene in affected cells while minimizing off-target expression. To achieve organ/cell-type specific targeting after intravenous delivery of viral vectors, we employed a Cre-transgenic-based screening platform for fast and efficient capsid selection, paired with sequential engineering of multiple surface-exposed loops. We identified capsid variants that are enriched in the brain and detargeted from the liver in mice. The improved enrichment in the brain extends to non-human primates, enabling robust, non-invasive gene delivery to the marmoset brain following IV administration. Importantly, the capsids identified display non-overlapping cell-type tropisms within the brain, with one exhibiting high specificity to neurons. The ability to cross the blood–brain barrier with cell-type specificity in rodents and non-human primates enables new avenues for basic research and potential therapeutic interventions unattainable with naturally occurring serotypes

Broad gene expression throughout the mouse and marmoset brain after intravenous delivery of engineered AAV capsids

Genetic intervention is increasingly explored as a therapeutic option for debilitating disorders of the central nervous system. The safety and efficacy of gene therapies relies upon expressing a transgene in affected cells while minimizing off-target expression. To achieve organ/cell-type specific targeting after intravenous delivery of viral vectors, we employed a Cre-transgenic-based screening platform for fast and efficient capsid selection, paired with sequential engineering of multiple surface-exposed loops. We identified capsid variants that are enriched in the brain and detargeted from the liver in mice. The improved enrichment in the brain extends to non-human primates, enabling robust, non-invasive gene delivery to the marmoset brain following IV administration. Importantly, the capsids identified display non-overlapping cell-type tropisms within the brain, with one exhibiting high specificity to neurons. The ability to cross the blood–brain barrier with cell-type specificity in rodents and non-human primates enables new avenues for basic research and potential therapeutic interventions unattainable with naturally occurring serotypes

Gut-seeded α-synuclein fibrils promote gut dysfunction and brain pathology specifically in aged mice

Parkinson’s disease is a synucleinopathy that is characterized by motor dysfunction, death of midbrain dopaminergic neurons and accumulation of α-synuclein (α-Syn) aggregates. Evidence suggests that α-Syn aggregation can originate in peripheral tissues and progress to the brain via autonomic fibers. We tested this by inoculating the duodenal wall of mice with α-Syn preformed fibrils. Following inoculation, we observed gastrointestinal deficits and physiological changes to the enteric nervous system. Using the AAV-PHP.S capsid to target the lysosomal enzyme glucocerebrosidase for peripheral gene transfer, we found that α-Syn pathology is reduced due to the increased expression of this protein. Lastly, inoculation of α-Syn fibrils in aged mice, but not younger mice, resulted in progression of α-Syn histopathology to the midbrain and subsequent motor defects. Our results characterize peripheral synucleinopathy in prodromal Parkinson’s disease and explore cellular mechanisms for the gut-to-brain progression of α-Syn pathology

Simultaneous time and frequency resolved fluorescence microscopy of single molecules.

Single molecule fluorophores were studied for the first time with a new confocal fluorescence microscope that allows the wavelength and emission time to be simultaneously measured with single molecule sensitivity. In this apparatus, the photons collected from the sample are imaged through a dispersive optical system onto a time and position sensitive detector. This detector records the wavelength and emission time of each detected photon relative to an excitation laser pulse. A histogram of many events for any selected spatial region or time interval can generate a full fluorescence spectrum and correlated decay plot for the given selection. At the single molecule level, this approach makes entirely new types of temporal and spectral correlation spectroscopy of possible. This report presents the results of simultaneous time- and frequency-resolved fluorescence measurements of single rhodamine 6G (R6G), tetramethylrhodamine (TMR), and Cy3 embedded in thin films of polymethylmethacrylate (PMMA)

Correlation between erythropoietin serum levels and erythrocyte susceptibility to lipid peroxidation in elderly with type 2 diabetes

Erythropoietin (EPO), a key hormone involved in red blood cell formation has been recently acknowledged for its pleiotropic actions and protective role in ageing and various pathological conditions concurrent with oxidative stress, vascular diseases and metabolic abnormalities such as diabetes mellitus. The aim of the study was to evaluate the relationship between circulating erythropoietin levels and oxidative stress biomarkers, in elderly with type 2 diabetes (T2DM). The study was carried out in 67 subjects with T2DM (69 ± 5 years; n = 37) without anemia, and aged-matched controls (70 ± 6 years; n = 30). EPO serum levels, erythrocyte susceptibility to lipid peroxidation (ESP) and total antioxidant capacity (TAC) were evaluated. Lower EPO levels (p < 0.01) and higher ESP values (p < 0.001) were found in T2DM group, compared to healthy subjects. EPO levels showed significant negative associations with ESP, both in T2DM subjects (r = −0.565; p < 0.001) and in all study population (r = –0,600; p < 0,001; n = 67). In conclusion, we provide new data regarding the cytoprotective effect of EPO exerted at systemic level on erythrocyte membrane, in the particular state of impaired glucose metabolism associated with oxidative stress, in the elderly

Intersection local times of independent fractional Brownian motions as generalized white noise functionals

In this work we present expansions of intersection local times of fractional Brownian motions in $\R^d$, for any dimension $d\geq 1$, with arbitrary Hurst coefficients in $(0,1)^d$. The expansions are in terms of Wick powers of white noises (corresponding to multiple Wiener integrals), being well-defined in the sense of generalized white noise functionals. As an application of our approach, a sufficient condition on $d$ for the existence of intersection local times in $L^2$ is derived, extending the results of D. Nualart and S. Ortiz-Latorre in "Intersection Local Time for Two Independent Fractional Brownian Motions" (J. Theoret. Probab.,20(4)(2007), 759-767) to different and more general Hurst coefficients.Comment: 28 page