251 research outputs found
A Synthetic Agonist to Vasoactive Intestinal Peptide Receptor-2 Induces Regulatory T Cell Neuroprotective Activities in Models of Parkinson\u27s Disease
A paradigm shift has emerged in Parkinson\u27s disease (PD) highlighting the prominent role of CD4+ Tregs in pathogenesis and treatment. Bench to bedside research, conducted by others and our own laboratories, advanced a neuroprotective role for Tregs making pharmacologic transformation of immediate need. Herein, a vasoactive intestinal peptide receptor-2 (VIPR2) peptide agonist, LBT-3627, was developed as a neuroprotectant for PD-associated dopaminergic neurodegeneration. Employing both 6-hydroxydopamine (6-OHDA) and Ξ±-synuclein (Ξ±-Syn) overexpression models in rats, the sequential administration of LBT-3627 increased Treg activity without altering cell numbers both in naΓ―ve animals and during progressive nigrostriatal degeneration. LBT-3627 administration was linked to reductions of inflammatory microglia, increased survival of dopaminergic neurons, and improved striatal densities. While Ξ±-Syn overexpression resulted in reduced Treg activity, LBT-3627 rescued these functional deficits. This occurred in a dose-dependent manner closely mimicking neuroprotection. Taken together, these data provide the basis for the use of VIPR2 agonists as potent therapeutic immune modulating agents to restore Treg activity, attenuate neuroinflammation, and interdict dopaminergic neurodegeneration in PD. The data underscore an important role of immunity in PD pathogenesis
Stretchable electronic platform for soft and smart contact lens applications
A stretchable platform with spherical-shaped electronics based on thermo-
plastic polyurethane (TPU) is introduced for soft smart contact lenses. The
low glass transition temperature of TPU, its relatively low hardness, and its
proven biocompatibility (i.e., protection of exterior body wounds) fulfill the
essential requirements for eye wearable devices. These requirements include
optical transparency, conformal fitting, and flexibility comparable with soft
contact lenses (e.g., hydrogel-based). Moreover, the viscoelastic nature of
TPU allows planar structures to be thermoformed into spherical caps with a
well-defined curvature (i.e., eyeβs curvature at the cornea: 9 mm). Numerical
modeling and experimental validation enable fine-tuning of the thermo -
forming parameters and the optimization of strain-release patterns. Such
tight control is proven necessary to achieve oxygen permeable, thin, nonde-
velopable, and wrinkle-free contact lenses with integrated electronics (silicon
die, radio-frequency antenna, and stretchable thin-film interconnections). This
work paves the way toward fully autonomous smart contact lenses potentially
for vision correction or sensing applications, among others
Europium-doped cerium oxide nanoparticles for microglial AΞ² clearance and homeostasis
Alzheimerβs disease (AD) is the most common neurodegenerative disorder. Pathologically, it is characterized by the deposition of amyloid beta (AΞ²) plaques and presence of neurofibrillary tangles. These drive microglia neuroinflammation and consequent neurodegeneration. While the means to affect AΞ² plaque accumulation was achieved how it affects disease outcomes remains uncertain. Cerium oxide (CeO2) reduces AΞ² plaques, oxidative stress, inflammation, and Alzheimerβs disease (AD) signs and symptoms. Specifically, CeO2 nanoparticles (CeO2NPs) induces free radical scavenging and cell protective intracellular signaling. This can ameliorate the pathobiology of an AD-affected brain. In order to investigate, CeO2NPs affects for microglia neurotoxic responses a novel formulation of europium doped CeO2NPs (EuCeO2NPs) was synthesized. We then tested EuCeO2NPs for itsβ abilities to generate cellular immune homeostasis in AD models. EuCeO2NPs attenuated microglia BV2 inflammatory activities after AΞ²1β42 exposure by increasing the cellsβ phagocytic and AΞ² degradation activities. These were associated with increases in the expression of the CD36 scavenger receptor. EuCeO2NPs facilitated AΞ² endolysosomal trafficking and abrogated microglial inflammatory responses. We posit that EuCeO2NPs may be developed as an AD immunomodulator
Automatic Compilation from High-Level Biologically-Oriented Programming Language to Genetic Regulatory Networks
Background
The field of synthetic biology promises to revolutionize our ability to engineer biological systems, providing important benefits for a variety of applications. Recent advances in DNA synthesis and automated DNA assembly technologies suggest that it is now possible to construct synthetic systems of significant complexity. However, while a variety of novel genetic devices and small engineered gene networks have been successfully demonstrated, the regulatory complexity of synthetic systems that have been reported recently has somewhat plateaued due to a variety of factors, including the complexity of biology itself and the lag in our ability to design and optimize sophisticated biological circuitry.
Methodology/Principal Findings
To address the gap between DNA synthesis and circuit design capabilities, we present a platform that enables synthetic biologists to express desired behavior using a convenient high-level biologically-oriented programming language, Proto. The high level specification is compiled, using a regulatory motif based mechanism, to a gene network, optimized, and then converted to a computational simulation for numerical verification. Through several example programs we illustrate the automated process of biological system design with our platform, and show that our compiler optimizations can yield significant reductions in the number of genes () and latency of the optimized engineered gene networks.
Conclusions/Significance
Our platform provides a convenient and accessible tool for the automated design of sophisticated synthetic biological systems, bridging an important gap between DNA synthesis and circuit design capabilities. Our platform is user-friendly and features biologically relevant compiler optimizations, providing an important foundation for the development of sophisticated biological systems.National Institutes of Health (U.S.) (Grant # 7R01GM74712-5)United States. Defense Advanced Research Projects Agency (contract HR0011-10-C-0168)National Science Foundation (U.S.) (NSF CAREER award 0968682)BBN Technologie
Mode-division multiplexed transmission with inline few-mode fiber amplifier
We demonstrate mode-division multiplexed WDM transmission over 50-km of few-mode fiber using the fiber\u27s LP01 and two degenerate LP11 modes. A few-mode EDFA is used to boost the power of the output signal before a few-mode coherent receiver. A 6x6 time-domain MIMO equalizer is used to recover the transmitted data. We also experimentally characterize the 50-km few-mode fiber and the few-mode EDFA
CD4+ Effector T cells Accelerate Alzheimer\u27s Disease in Mice
BACKGROUND: Alzheimer\u27s disease (AD) is a progressive neurodegenerative disorder characterized by pathological deposition of misfolded self-protein amyloid beta (AΞ²) which in kind facilitates tau aggregation and neurodegeneration. Neuroinflammation is accepted as a key disease driver caused by innate microglia activation. Recently, adaptive immune alterations have been uncovered that begin early and persist throughout the disease. How these occur and whether they can be harnessed to halt disease progress is unclear. We propose that self-antigens would induct autoreactive effector T cells (Teffs) that drive pro-inflammatory and neurodestructive immunity leading to cognitive impairments. Here, we investigated the role of effector immunity and how it could affect cellular-level disease pathobiology in an AD animal model.
METHODS: In this report, we developed and characterized cloned lines of amyloid beta (AΞ²) reactive type 1 T helper (Th1) and type 17 Th (Th17) cells to study their role in AD pathogenesis. The cellular phenotype and antigen-specificity of AΞ²-specific Th1 and Th17 clones were confirmed using flow cytometry, immunoblot staining and AΞ² T cell epitope loaded haplotype-matched major histocompatibility complex II IA
RESULTS: The propagated AΞ²-Th1 and AΞ²-Th17 clones were confirmed stable and long-lived. Treatment of APP/PS1 mice with AΞ² reactive Teffs accelerated memory impairment and systemic inflammation, increased amyloid burden, elevated microglia activation, and exacerbated neuroinflammation. Both Th1 and Th17 AΞ²-reactive Teffs progressed AD pathology by downregulating anti-inflammatory and immunosuppressive regulatory T cells (Tregs) as recorded in the periphery and within the central nervous system.
CONCLUSIONS: These results underscore an important pathological role for CD4+ Teffs in AD progression. We posit that aberrant disease-associated effector T cell immune responses can be controlled. One solution is by AΞ² reactive Tregs
Defending the genome from the enemy within:mechanisms of retrotransposon suppression in the mouse germline
The viability of any species requires that the genome is kept stable as it is transmitted from generation to generation by the germ cells. One of the challenges to transgenerational genome stability is the potential mutagenic activity of transposable genetic elements, particularly retrotransposons. There are many different types of retrotransposon in mammalian genomes, and these target different points in germline development to amplify and integrate into new genomic locations. Germ cells, and their pluripotent developmental precursors, have evolved a variety of genome defence mechanisms that suppress retrotransposon activity and maintain genome stability across the generations. Here, we review recent advances in understanding how retrotransposon activity is suppressed in the mammalian germline, how genes involved in germline genome defence mechanisms are regulated, and the consequences of mutating these genome defence genes for the developing germline
Morphine Induces Expression of Platelet-Derived Growth Factor in Human Brain Microvascular Endothelial Cells: Implication for Vascular Permeability
Despite the advent of antiretroviral therapy, complications of HIV-1 infection with concurrent drug abuse are an emerging problem. Morphine, often abused by HIV-infected patients, is known to accelerate neuroinflammation associated with HIV-1 infection. Detailed molecular mechanisms of morphine action however, remain poorly understood. Platelet-derived growth factor (PDGF) has been implicated in a number of pathological conditions, primarily due to its potent mitogenic and permeability effects. Whether morphine exposure results in enhanced vascular permeability in brain endothelial cells, likely via induction of PDGF, remains to be established. In the present study, we demonstrated morphine-mediated induction of PDGF-BB in human brain microvascular endothelial cells, an effect that was abrogated by the opioid receptor antagonist-naltrexone. Pharmacological blockade (cell signaling) and loss-of-function (Egr-1) approaches demonstrated the role of mitogen-activated protein kinases (MAPKs), PI3K/Akt and the downstream transcription factor Egr-1 respectively, in morphine-mediated induction of PDGF-BB. Functional significance of increased PDGF-BB manifested as increased breach of the endothelial barrier as evidenced by decreased expression of the tight junction protein ZO-1 in an in vitro model system. Understanding the regulation of PDGF expression may provide insights into the development of potential therapeutic targets for intervention of morphine-mediated neuroinflammation
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