Infantile Batten Disease: Effective Therapy and Novel Model

Infantile neuronal ceroid lipofuscinosis (INCL, Infantile Batten) is typically an early onset, neurodegenerative lysosomal storage disorder. INCL is caused by mutations to the gene CLN1 which codes for the lysosomal enzyme palmitoyl-protein thioesterase-1 (PPT1). PPT1 is a soluble lysosomal enzyme that functions to cleave fatty acyl chains from proteins destined for degradation. Deficiency in PPT1 leads to the accumulation of autofluorescent storage material, a hallmark of the NCLs. The storage material has been implicated in progressive histopathological changes in the brain such as neuronal loss, astrocytosis, microgliosis, and immune cell infiltration. These histopathological changes result in a progression of clinical signs including vision loss, decline in motor function, cognitive deficits, seizures, and premature death. Currently, there are no cures or treatments for INCL. However, a murine model of INCL has been used in pre-clinical therapy studies. The PPT1-/- mouse has been shown to be a reliable model for the human INCL disease. Detailed temporal and spatial histopathological examinations of murine INCL in the brain have led to intracranial gene therapy studies. These pre-clinical studies have resulted in significant improvements in biochemical, histopathological, and functional deficits seen in the untreated PPT1-/- mouse. However, there have only been modest improvements in lifespan. Given the identification and development of improved gene therapy vectors, this was a surprising finding. Therefore, the first section of the dissertation, we pursued a more thorough characterization of the central nervous system to identify potential regions of disease not targeted by intracranial gene therapy. We identified the spinal cord as a significant site of disease that was not previously characterized or corrected. This allowed us to target both the brain and spinal cord with AAV-based gene therapy. We demonstrated that targeting the entirety of the central nervous system was necessary to treat INCL more effectively. From these and historical studies, we identified a multitude of cell types that are involved with INCL pathogenesis. In the central nervous system, INCL has been shown to progress sequentially from astrocytosis, to neuronal loss, to microgliosis and immune cell infiltration. PPT1 is ubiquitously expressed; therefore, its deficiency in INCL could lead to pathology in every cell type. Currently, we are unable to model cellular and metabolic changes in specific cell types in INCL due to ‘cross-correction’. While ‘cross-correction’ is beneficial for the development of therapeutics, it interferes with our ability to understand the role of PPT1 in specific cell types. Therefore, in the second section of the dissertation, we sought to determine the cell-autonomous nature of PPT1. Because PPT1 is a soluble lysosomal hydrolase that can undergo ‘cross-correction’, we developed a chimeric enzyme whereby PPT1 is tethered to the lysosomal membrane. We demonstrated that tethered PPT1 retains its enzymatic function and does not ‘cross-correct’ in vitro and in vivo. We further demonstrated that near-ubiquitous expression of tethered PPT1 could prevent INCL. This lays the groundwork for future studies designed to determine the role of specific cell types in the pathogenesis of INCL

Dynamic modeling, property investigation, and adaptive controller design of serial robotic manipulators modeled with structural compliance

Research results on general serial robotic manipulators modeled with structural compliances are presented. Two compliant manipulator modeling approaches, distributed and lumped parameter models, are used in this study. System dynamic equations for both compliant models are derived by using the first and second order influence coefficients. Also, the properties of compliant manipulator system dynamics are investigated. One of the properties, which is defined as inaccessibility of vibratory modes, is shown to display a distinct character associated with compliant manipulators. This property indicates the impact of robot geometry on the control of structural oscillations. Example studies are provided to illustrate the physical interpretation of inaccessibility of vibratory modes. Two types of controllers are designed for compliant manipulators modeled by either lumped or distributed parameter techniques. In order to maintain the generality of the results, neither linearization is introduced. Example simulations are given to demonstrate the controller performance. The second type controller is also built for general serial robot arms and is adaptive in nature which can estimate uncertain payload parameters on-line and simultaneously maintain trajectory tracking properties. The relation between manipulator motion tracking capability and convergence of parameter estimation properties is discussed through example case studies. The effect of control input update delays on adaptive controller performance is also studied

Monoacylated Cellular Prion Proteins Reduce Amyloid-beta-Induced Activation of Cytoplasmic Phospholipase A2 and Synapse Damage

Alzheimer’s disease (AD) is a progressive neurodegenerative disease characterized by the accumulation of amyloid-β (Aβ) and the loss of synapses. Aggregation of the cellular prion protein (PrPC) by Aβ oligomers induced synapse damage in cultured neurons. PrPC is attached to membranes via a glycosylphosphatidylinositol (GPI) anchor, the composition of which affects protein targeting and cell signaling. Monoacylated PrPC incorporated into neurons bound “natural Aβ”, sequestering Aβ outside lipid rafts and preventing its accumulation at synapses. The presence of monoacylated PrPC reduced the Aβ-induced activation of cytoplasmic phospholipase A2 (cPLA2) and Aβ-induced synapse damage. This protective effect was stimulus specific, as treated neurons remained sensitive to α-synuclein, a protein associated with synapse damage in Parkinson’s disease. In synaptosomes, the aggregation of PrPC by Aβ oligomers triggered the formation of a signaling complex containing the cPLA2.a process, disrupted by monoacylated PrPC. We propose that monoacylated PrPC acts as a molecular sponge, binding Aβ oligomers at the neuronal perikarya without activating cPLA2 or triggering synapse damage

Aluminum alters NMDA receptor 1A and 2A/B expression on neonatal hippocampal neurons in rats

<p>Abstract</p> <p>Background</p> <p>High aluminum (Al) content in certain infant formula raises the concern of possible Al toxicity on brain development of neonates during their vulnerable period of growing. Results of in vivo study showed that Al content of brain tissues reached to 74 μM when oral intake up to 1110 μM, 10 times of that in the hi-Al infant formula.</p> <p>Methods</p> <p>Utilizing a cultured neuron cells in vitro model, we have assessed Al influence on neuronal specific gene expression alteration by immunoblot and immunohistochemistry and neural proliferation rate changes by MTT assay.</p> <p>Results</p> <p>Microscopic images showed that the neurite outgrowth of hippocampal neurons increased along with the Al dosages (37, 74 μM Al (AlCl₃)). MTT results also indicated that Al increased neural cell viability. On the other hand, the immunocytochemistry staining suggested that the protein expressions of NMDAR 1A and NMDAR 2A/B decreased with the Al dosages (p < 0.05).</p> <p>Conclusion</p> <p>Treated hippocampal neurons with 37 and 74 μM of Al for 14 days increased neural cell viability, but hampered NMDAR 1A and NMDAR 2A/B expressions. It was suggested that Al exposure might alter the development of hippocampal neurons in neonatal rats.</p

An industrialized housing system

Thesis. 1975. M.Arch.A.S.--Massachusetts Institute of Technology. Dept. of Architecture.Bibliography: leaf 62.by Shyng Miin Chen.M.Arch.A.S

Effects of Mechanical Harvest and Site Preparation on Stormflow Water Yields and Sediment Yields from Forest Watersheds in Ouachita Mountains of Oklahoma

Forest Resource