異なる動物種由来の AA アミロイド線維形態の比較とロスマリン酸による血清アミロイドA凝集の阻害に関する研究

アミロイドーシスは、βシートに富むアミロイド原線維の細胞外沈着を特徴とする疾患であり、現在、アミロイド原線維を形成する50種類以上の前駆体タンパク質またはペプチドが知られている。これらが凝集、蓄積しアミロイド原線維としてプラークに沈着することで、臓器機能障害が引き起こされる。アミロイドA（AA）アミロイドーシスは、世界中の人間や家畜に頻繁に見られるアミロイド性疾患であり、関節リウマチや結核など重度の慢性炎症患者に発症する。血清アミロイドA（SAA）は、脊椎動物で高度に進化的に保存された、AAアミロイドーシスにおいて最も重要な前駆体アミロイドタンパク質の1つである。本研究では、まず、AAアミロイドーシスを発症した5つの異なる動物種（マウス、牛、山羊、犬、ラクダ）からアミロイド線維を精製し、これらの線維の幅と交差距離を透過型電子顕微鏡観察により測定した。その結果、精製したアミロイド原線維はクロス構造を持ち、不規則な長さを有する線状の形態を示すことが分かった。また、これらのアミロイド原線維の形態的な特徴は、それぞれの動物間のSAA遺伝子の相同性と相関することが示唆された。本研究ではさらに、アミロイドβ（Aβ）の凝集阻害剤として知られるロスマリン酸（RA）が、in vitroでSAA凝集に対して阻害活性を示すことを、量子ドットナノプローブを用いた微量ハイスループットスクリーニング（MSHTS）システムにより明らかにした。そこで、2% RAを有効成分として含むレモンバーム（Melissa officinalis）抽出物（ME）を食餌によりマウスに投与し、その血液から調製した血清のアミロイド凝集抑制活性と臓器へのSAAの沈着を評価した。興味深いことに、MSHTSシステムで評価したSAAおよびAβ凝集に対するME給餌マウス血清の阻害活性は、対照群よりも高かった。 また、MEを投与したマウス臓器におけるSAA沈着量は、対照群よりも少なく、血清のSAA凝集阻害活性がSAA沈着と関連していることを示唆した。これらの結果は、RAを含むMEの食餌による摂取が血液のアミロイド凝集阻害活性を増強し、臓器におけるSAA沈着を抑制したことを示唆した。さらに、本研究は、MSHTSシステムがin vitroスクリーニングだけでなく、分解され血液に吸収された食品の包括的なアミロイド凝集阻害活性の評価に適用できることを証明した。これらの研究成果は、アミロイド疾患の理解、および治療や予防のための新しい戦略の提供に貢献することが期待される。Amyloidosis, which is characterized by the extracellular deposit of β-sheet rich amyloid fibrils, is currently classified into more than 50 different types of medical associations based on precursor proteins or peptides. The aggregates of these proteins accumulated and deposited as amyloid fibrils into plaques which resulting organ dysfunction. Amyloid A (AA) amyloidosis is an amyloid-based disease frequently found in humans and livestock worldwide. It develops in patients with severe chronic inflammatory such as rheumatoid arthritis, and tuberculosis, among others. Serum amyloid A (SAA) is a highly evolutionarily conserved protein in vertebrates that is encoded by a family of closely related genes. And it is one of the most important precursor amyloid proteins and plays a vital step in AA amyloidosis. In this study, I first purified amyloid fibrils from five different animal species (mouse, cow, goat, dog, and camel) with AA amyloidosis, and measured these fibrils width and crossover distance by transmission electron microscopy. These results showed that amyloid fibrils had a linear morphology with a cross structure and irregular length in vivo. These data also suggested that the fibrils from different animal species have similar genetic homology in SAA sequences and morphology. Furthermore, I showed that rosmarinic acid (RA), which is a well-known inhibitor of the aggregation of amyloid β (Aβ), displayed inhibitory activity against SAA aggregation in vitro using a microliter-scale high-throughput screening (MSHTS) system with quantum-dot nanoprobes. Therefore, I evaluated the amyloid aggregation inhibitory activity of serum prepared from blood and the deposition of SAA in organs by feeding mice with Melissa officinalis extract (ME) containing 2% RA as an active substance. Interestingly, the inhibitory activity of ME-fed mice sera for SAA and Aβ aggregation, measured with the MSHTS system, were higher than that of the control group. The amount of amyloid deposition in the organs of ME-fed mice was lower than that in the control group, suggesting that the SAA aggregation inhibitory activity of serum is associated with SAA deposition. These results suggested that dietary intake of RA containing ME enhanced amyloid aggregation inhibitory activity of blood and suppressed SAA deposition in organs. Besides, this study also demonstrated that the MSHTS system could be applied to in vitro screening and to monitor the comprehensive activity of metabolized foods adsorbed by blood. I hope these findings will aid in the understanding of amyloid diseases and are inspiring new strategies for therapeutic intervention.室蘭工業大学 (Muroran Institute of Technology)博士（工学）当アイテムは要旨のみの公開になっています（2021-6-23

Numerical Modeling of a Teeth-shaped Nano-plasmonic Waveguide Filter

In this paper, tooth-shaped and multiple-teeth-shaped plasmonic filters in the metal-insulator-metal (MIM) waveguides are demonstrated numerically. By introducing a three-port waveguide splitter, a modified model based on the multiple-beam-interference and the scattering matrix is given. The ransmittance spectrum as a function of teeth width, depth, period and period number are respectively addressed. The result shows the new structure not only performs the filtering function as well as MIM grating-like structures, but also is of submicrometer size for ultra-high integration and relatively easy fabrication.Comment: 21pages, 7 figure

Temperature and magnetism bi-responsive molecularly imprinted polymers: Preparation, adsorption mechanism and properties as drug delivery system for sustained release of 5-fluorouracil

This document is the Accepted Manuscript version of the following article: Longfei Li, Lin Chen, Huan Zhang, Yongshen Yang, Xuguang Liu, and Yongkang Chen, ‘Temperature and magnetism bi-responsive molecularly imprinted polymers: Preparation, adsorption mechanism and properties as drug delivery system for sustained release of 5-fluorouracil’, Materials Science and Engineering: C, Vol. 61: 158-168, April 2016, made available under the terms of the Creative Commons Attribution-NonCommercial-NoDerivatives License CC BY NC-ND 4.0 (http://creativecommons.org/licenses/by-nc-nd/4.0/).Temperature and magnetism bi-responsive molecularly imprinted polymers (TMMIPs) based on Fe3O4-encapsulating carbon nanospheres were prepared by free radical polymerization, and applied to selective adsorption and controlled release of 5-fluorouracil (5-FU) from an aqueous solution. Characterization results show that the as-synthesized TMMIPs have an average diameter of about 150 nm with a typical core–shell structure, and the thickness of the coating layer is approximately 50 nm. TMMIPs also displayed obvious magnetic properties and thermo-sensitivity. The adsorption results show that the prepared TMMIPs exhibit good adsorption capacity (up to 96.53 mg/g at 25 °C) and recognition towards 5-FU. The studies on 5-FU loading and release in vitro suggest that the release rate increases with increasing temperature. Meanwhile, adsorption mechanisms were explored by using a computational analysis to simulate the imprinted site towards 5-FU. The interaction energy between the imprinted site and 5-FU is − 112.24 kJ/mol, originating from a hydrogen bond, Van der Waals forces and a hydrophobic interaction between functional groups located on 5-FU and a NIPAM monomer. The electrostatic potential charges and population analysis results suggest that the imprinted site of 5-FU can be introduced on the surface of TMMIPs, confirming their selective adsorption behavior for 5-FU.Peer reviewe

Evaluation of amyloid β42 aggregation inhibitory activity of commercial dressings by a microliter-scale high-throughput screening system using quantum-dot nanoprobes

The aggregation and accumulation of amyloid β (Aβ) in the brain is a trigger of pathogenesis for Alzheimer’s disease. Previously, we developed a microliter-scale high-throughput screening (MSHTS) system for Aβ42 aggregation inhibitors using quantum-dot nanoprobes. The MSHTS system is seldom influenced by contaminants in samples and is able to directly evaluate Aβ42 aggregation inhibitory activity of samples containing various compounds. In this study, to elucidate whether the MSHTS system could be applied to the evaluation of processed foods, we examined Aβ42 aggregation inhibitory activity of salad dressings, including soy sauces. We estimated the 50% effective concentration (EC50) from serial diluted dressings. Interestingly, all 19 commercial dressings tested showed Aβ42 aggregation inhibitory activity. It was suggested that EC50 differed by as much as 100 times between the dressings with the most (0.065 ± 0.020 v/v%) and least (6.737 ± 5.054 v/v%) inhibitory activity. The highest activity sample is traditional Japanese dressing, soy sauce. It is known that soy sauce is roughly classified into a heat-treated variety and a non-heat-treated variety. We demonstrated that non-heat-treated raw soy sauce exhibited higher Aβ42 aggregation inhibitory activity than heat-treated soy sauce. Herein, we propose that MSHTS system can be applied to processed foods

Aggregation of Mouse Serum Amyloid A Protein Was Promoted by Amyloid-Enhancing Factors with the More Genetically Homologous Serum Amyloid A

Amyloid A (AA) amyloidosis is a condition in which amyloid fibrils characterized by a linear morphology and a cross-beta structure accumulate and are deposited extracellularly in organs, resulting in chronic inflammatory diseases and infections. The incidence of AA amyloidosis is high in humans and several animal species. Serum amyloid A (SAA) is one of the most important precursor amyloid proteins and plays a vital step in AA amyloidosis. Amyloid enhancing factor (AEF) serves as a seed for fibril formation and shortens the onset of AA amyloidosis sharply. In this study, we examined whether AEFs extracted and purified from five animal species (camel, cat, cattle, goat, and mouse) could promote mouse SAA (mSAA) protein aggregation in vitro using quantum-dot (QD) nanoprobes to visualize the aggregation. The results showed that AEFs shortened and promoted mSAA aggregation. In addition, mouse and cat AEFs showed higher mSAA aggregation-promoting activity than the camel, cattle, and goat AEFs. Interestingly, homology analysis of SAA in these five animal species revealed a more similar amino acid sequence homology between mouse and cat than between other animal species. Furthermore, a detailed comparison of amino acid sequences suggested that it was important to mSAA aggregation-promoting activity that the 48th amino acid was a basic residue (Lys) and the 125th amino acid was an acidic residue (Asp or Glu). These data imply that AA amyloidosis exhibits higher transmission activity among animals carrying genetically homologous SAA gene, and may provide a new understanding of the pathogenesis of amyloidosis

Real-Time 3D Imaging and Inhibition Analysis of Various Amyloid Aggregations Using Quantum Dots

Amyloidosis refers to aggregates of protein that accumulate and are deposited as amyloid fibrils into plaques. When these are detected in organs, they are the main hallmark of Alzheimer’s disease, Parkinson’s disease, and other related diseases. Recent medical advances have shown that many precursors and proteins can induce amyloidosis even though the mechanism of amyloid aggregation and the relationship of these proteins to amyloidosis remains mostly unclear. In this study, we report the real-time 3D-imaging and inhibition analysis of amyloid B (AB ), tau, and a-synuclein aggregation utilizing the a nity between quantum dots (QD) and amyloid aggregates. We successfully visualized these amyloid aggregations in real-time using fluorescence microscopy and confocal microscopy simply by adding commercially available QD. The observation by transmission electron microscopy (TEM) showed that QD particles bound to all amyloid fibrils. The 3D-imaging with QD revealed di erences between amyloid aggregates composed of di erent amyloid peptides that could not be detected by TEM.We were also able to quantify the inhibition activities of these proteins by rosmarinic acid, which has high activity for AB aggregation, from fluorescence micrographs as half-maximal e ective concentrations. These imaging techniques with QD serve as quick, easy, and powerful tools to understand amyloidosis and to discover drugs for therapies

Dry Eye Syndrome in Patients with Diabetes Mellitus: Prevalence, Etiology, and Clinical Characteristics

There has been substantial progress in our understanding of the ocular surface system/lacrimal function unit in the past 15 years. Keratoconjunctivitis sicca, more commonly referred to as dry eye syndrome (DES), is the most frequently encountered condition and diabetes mellitus (DM) has been identified as one of the leading causes of DES. Poor glycemic control affects both the anterior and the posterior segments of the eye and increasing prevalence of diabetes-associated DES (DMDES) has been reported in recent years. The pathogenesis and specific features of DMDES remain uncertain and interventions are limited to those used in DES. This review outlines the pathogenesis, clinical manifestations, and the current preventive and treatment strategies for diabetes-related DES