Alzheimer's Disease: A Giving Smarter Guide

Alzheimer's disease (Alzheimer's, AD) is the sixth leading cause of death in the United States (U.S.), claiming the lives of more than 500,000 individuals each year. Today, approximately 5.3 million Americans are living with this disease. AD burdens the U.S. with a project economic cost of $226 billion in 2015, and is on pace to cost$1.1 trillion in 2050. Although AD is widely recognized as an epidemic by individual nations as well as by the World Health Organization, progress in AD clinical research and integrated care has been modest at best. Key challenges to combating this disease include: Poor understanding of disease onset and progressionGaps in funding to support high-risk research effortsInsufficient research tools and companion resourcesLack of disease-modifying treatmentsLimited public awareness of its societal impact In order to avoid the economic and social catastrophes caused by AD, we must address these deficiencies. Strategic focus on funding high-impact research and critical infrastructure to support both AD research and patients are essential to achieving this goal. The Milken Institute Philanthropy Advisory Service has developed this Giving Smarter Guide for Alzheimer's disease to help patients, supporters, and other stakeholders understand the state of the science and how they can help accelerate research progress. Although philanthropy accounts for only 3 percent of medical research funding, it can have an outsized impact if it is strategically focused. This guide will help to answer the following questions: What are key facts about the disease?Why is it important to invest in AD research?What is the current state of care?What is the current state of research?What are major barriers to progress?How can philanthropy advance a cure for AD

Purification and Reconstitution into Planar Bilayers of the Human Dopamine Transporter

The human dopamine transporter (hDAT) provides the primary mechanism for dopamine clearance in synapses and thus facilitates the regulation of dopaminergic functions in cognition and reward. It is the molecular target of many centrally-active agents including amphetamines and cocaine. Therefore, an understanding of hDAT function and its modulation by these therapeutic drugs and drugs of abuse can provide insight into the mechanisms of abuse and addiction. In the presented studies, hDAT is tagged with a hexahistidine construct and heterologously expressed in Xenopus laevis oocytes. The plasma membranes are isolated, solubilized, and applied to a Nickel affinity column to obtain purified hDAT with preserved functionality. Purified hDAT reconstituted in planar lipid bilayers exhibited channel behaviors at physiological membrane potentials. We observed that the current mediated by single hDAT molecules is (1) induced by dopamine, (2) dependent on the sodium electrochemical gradient, and (3) blocked by cocaine. Our data support hDAT channel activity that is associated with dopamine uptake and presents a novel electrophysiological approach to studying monoamine transporter function and modulation by drugs

Single-molecule studies reveal the dynamics of DNA repair and transcription-associated proteins

Intrinsically disordered regions (IDR) are protein segments that lack a defined tertiary structure. IDRs are enriched in eukaryotic chromatin-binding proteins, where they modulate protein-DNA and protein-protein interactions. In this thesis, I probe the function(s) of IDRs via two case studies: the yeast mismatch repair (MMR) protein Mlh1- Pms1 and transcription factors (TFs) derived from C. albicans, a pathogenic yeast. Using single-molecule DNA curtain assays, I demonstrate novel roles for IDRs in promoting facilitated diffusion of Mlh1-Pms1 on DNA. IDRs improve Mlh1-Pms1’s ability to bypass a single nucleosome and to navigate dense nucleosome arrays that resemble chromatin. Moreover, these IDRs are critical for the Mlh1-Pms1 ATPase activity and also for nicking of the DNA substrate. I propose that conformational changes in the Mlh1-Pms1 IDRs alter DNA interactions and the nucleolytic activity of neighboring structured domains. I also examine the dynamics of PCNA, another essential MMR factor, in the context of trinucleotide repeat (TNR) instability. I show that Replication Factor C preferentially loads PCNA onto (CAG)₁₃ structures. The (CAG)₁₃ repeat captures the loaded PCNA and prevents PCNA from diffusing. Lastly, I reveal a novel role for IDRs in DNA condensation by studying Efg1, a TF that regulates a cell-type switching network in C. albicans. Efg1 encodes a specific IDR of low complexity, referred to as the prion-like domain (PrLD). I show that the PrLD is critical for the DNA condensation and recruiting other PrLD-containing TFs, wherein nucleosomes regulate the TF-DNA dynamics. I propose a model where transcription factors become concentrated via phase separation and bring gene regulatory elements together to promote gene activation. Overall, this study provides mechanistic insights into the functions of IDRs in the dynamic behavior of DNA-binding proteinsBiochemistr

In-rich InGaN/GaN quantum wells grown by metal-organic chemical vapor deposition

Growth mechanism of In-rich InGaN/GaN quantum wells (QWs) was investigated. First, we examined the initial stage of InN growth on GaN template considering strain-relieving mechanisms such as defect generation, islanding, and alloy formation at 730 degrees C. It was found that, instead of formation of InN layer, defective In-rich InGaN layer with thickness fluctuations was formed to relieve large lattice mismatch over 10% between InN and GaN. By introducing growth interruption (GI) before GaN capping at the same temperature, however, atomically flat InGaN/GaN interfaces were observed, and the quality of In-rich InGaN layer was greatly improved. We found that decomposition and mass transport processes during GI in InGaN layer are responsible for this phenomenon. There exists severe decomposition in InGaN layer during GI, and a 1-nm-thick InGaN layer remained after GI due to stronger bond strength near the InGaN/GaN interface. It was observed that the mass transport processes actively occurred during GI in InGaN layer above 730 degrees C so that defect annihilation in InGaN layer was greatly enhanced. Finally, based on these experimental results, we propose the growth mechanism of In-rich InGaN/GaN QWs using GI.open9

Hippocampal glucose uptake as a surrogate of metabolic change of microglia in Alzheimers disease

Abstract Background Dynamically altered microglia play an important role in the progression of Alzheimers disease (AD). Here, we found a close association of the metabolic reconfiguration of microglia with increased hippocampal glucose uptake on [18F]fluorodeoxyglucose (FDG) PET. Methods We used an AD animal model, 5xFAD, to analyze hippocampal glucose metabolism using both animal FDG PET and ex vivo FDG uptake test. Cells of the hippocampus were isolated to perform single-cell RNA-sequencing (scRNA-seq). The molecular features of cells associated with glucose metabolism were analyzed at a single-cell level. In order to apply our findings to human brain imaging study, brain FDG PET data obtained from the Alzheimers Disease Neuroimaging Initiative were analyzed. FDG uptake in the hippocampus was compared according to the diagnosis, AD, mild cognitive impairment, and controls. The correlation analysis between hippocampal FDG uptake and soluble TREM2 in cerebrospinal fluid was performed. Results In the animal study, 8- and 12-month-old 5xFAD mice showed higher FDG uptake in the hippocampus than wild-type mice. Cellular FDG uptake tests showed that FDG activity in hippocampal microglia was increased in the AD model, while FDG activity in non-microglial cells of the hippocampus was not different between the AD model and wild-type. scRNA-seq data showed that changes in glucose metabolism signatures including glucose transporters, glycolysis and oxidative phosphorylation, mainly occurred in microglia. A subset of microglia with higher glucose transporters with defective glycolysis and oxidative phosphorylation was increased according to disease progression. In the human imaging study, we found a positive association between soluble TREM2 and hippocampal FDG uptake. FDG uptake in the hippocampus at the baseline scan predicted mild cognitive impairment conversion to AD. Conclusions We identified the reconfiguration of microglial glucose metabolism in the hippocampus of AD, which could be evaluated by FDG PET as a feasible surrogate imaging biomarker for microglia-mediated inflammation

Regulation of loop extrusion on the interphase genome

In the human cell nucleus, dynamically organized chromatin is the substrate for gene regulation, DNA replication, and repair. A central mechanism of DNA loop formation is an ATPase motor cohesin-mediated loop extrusion. The cohesin complexes load and unload onto the chromosome under the control of other regulators that physically interact and affect motor activity. Regulation of the dynamic loading cycle of cohesin influences not only the chromatin structure but also genome-associated human disorders and aging. This review focuses on the recently spotlighted genome organizing factors and the mechanism by which their dynamic interactions shape the genome architecture in interphase. © 2023 Informa UK Limited, trading as Taylor & Francis Group.FALS

The effects of Cu(II) ion as an additive on NH3 loss and CO2 absorption in ammonia-based CO2 capture processes

Chemical CO2 absorption is one of the most cost- and energy-intensive processes in carbon capture and storage (CCS) technology. Among various absorption processes, ammonia-based processes attract much attention, due to many benefits: high CO2 absorption rate and low energy consumption for ammonia regeneration. Ammonia-based processes, however, have a problem to be solved for practical implementation due to the high vapor pressure of ammonia, which incurs ammonia loss during regeneration. In this study, the effect of Cu(II) ion as an additive on NH3 loss and CO2 absorption was investigated to examine the potential of Cu(II) ion to enhance the economic performance of ammonia-based processes. Continuous operations were conducted with and without the addition of Cu(II) ion. The results showed that the addition of Cu(II) ion noticeably decreased NH3 loss in the regeneration process due to the complexation of copper and ammonium ions, i.e., [Cu(NH3)(4)](2+). The Cu(II) addition also increased the CO2 absorption capacity in the absorption process because ammonia concentration remained higher. In conclusion, Cu(II) ion can be used to reduce ammonia make-up cost and to enhance CO2 absorption performance in ammonia-based CO2 capture processes. (C) 2012 Elsevier B.V. All rights reserved.11sciescopu

Fluid-driven DNA stretching for single-molecule studies on chromatin-associated proteins

There have been many attempts to understand the central principle of life mediated by DNA-protein interactions surrounding complex environments. Still, the mechanistic insight of individual protein functions has been lacking in traditional ensemble assays. Thus, techniques visualizing a single molecule have emerged to uncover the discrete roles of DNA-protein interactions and their biophysical properties. This paper will review the advances in single-molecule tools imaging long genomic DNA and their applications in studying dynamic protein interactions. We focus on the three representative techniques, including molecular combing, nanochannel confinement, and DNA curtain assays, which use fluid-driven force to elongate the individual DNA. We provide an integrated perspective and a direction for future use to those who want to observe single DNA molecules along with their cellular factor of interest and employ them for dissecting protein function. © 2022 Elsevier Inc.FALS