Characterization of Urate Transport System in JAR and JEG-3 Cells, Human Trophoblast-derived Cell Lines

Urate (uric acid) is the major inert end product of purine metabolism in humans. Since it is water soluble, it requires a membranous protein called transporter for its permeation across the plasma membrane. Increased blood urate level is often seen in preeclampsia, but its precise mechanism remains unknown. Syncytiotrophoblasts function as a barrier between maternal blood and fetal one so called “blood-placental barrier”. So far, the expression of several urate transporters was identified in these cells, but it is still unclear about their contribution to urate handling in blood-placental barrier. In this study, we investigated the expression of urate transporters and the properties of ［14C］urate transport in both JAR and JEG-3, human choriocarcinoma cells as a model of human placenta. Conventional PCR analysis revealed that both JAR and JEG-3 cells express strongly breast cancer resistance protein (BCRP/ABCG2) mRNA. Uptake of ［14C］urate by these cells is time-dependent with Na＋- and Cl－-independent and voltage-insensitive manner and is not inhibited by benzbromarone, a representative renal urate transport inhibitor. Then, we focused on BCRP which shows strong mRNA expression and found that these cells have urate efflux property that is sensitive to fumitremorgin C (FMC), a BCRP inhibitor. These results suggest that BCRP is one of the important components for urate handling in human placenta in pathophysiological condition such as preeclampsia

Detection of viral RNA in diverse body fluids in an SFTS patient with encephalopathy, gastrointestinal bleeding and pneumonia: a case report and literature review

BACKGROUND: Severe fever with thrombocytopenia syndrome (SFTS) is an emerging infectious disease that commonly has a lethal course caused by the tick-borne Huaiyangshan banyang virus [former SFTS virus (SFTSV)]. The viral load in various body fluids in SFTS patients and the best infection control measure for SFTS patients have not been fully established. CASE PRESENTATION: A 79-year-old man was bitten by a tick while working in the bamboo grove in Nagasaki Prefecture in the southwest part of Japan. Due to the occurrence of impaired consciousness, he was referred to Nagasaki University Hospital for treatment. The serum sample tested positive for SFTSV-RNA in the genome amplification assay, and he was diagnosed with SFTS. Furthermore, SFTSV-RNA was detected from the tick that had bitten the patient. He was treated with multimodal therapy, including platelet transfusion, antimicrobials, antifungals, steroids, and continuous hemodiafiltration. His respiration was assisted with mechanical ventilation. On day 5, taking the day on which he was hospitalized as day 0, serum SFTSV-RNA levels reached a peak and then decreased. However, the cerebrospinal fluid collected on day 13 was positive for SFTSV-RNA. In addition, although serum SFTSV-RNA levels decreased below the detectable level on day 16, he was diagnosed with pneumonia with computed tomography. SFTSV-RNA was detected in the bronchoalveolar lavage fluid on day 21. By day 31, he recovered consciousness completely. The pneumonia improved by day 51, but SFTSV-RNA in the sputum remained positive for approximately 4 months after disease onset. Strict countermeasures against droplet/contact infection were continuously conducted. CONCLUSIONS: Even when SFTSV genome levels become undetectable in the serum of SFTS patients in the convalescent phase, the virus genome remains in body fluids and tissues. It may be possible that body fluids such as respiratory excretions become a source of infection to others; thus, careful infection control management is needed

Associations between Chest CT Abnormalities and Clinical Features in Patients with the Severe Fever with Thrombocytopenia Syndrome

Severe fever with thrombocytopenia syndrome (SFTS) is an emerging infectious disease caused by the SFTS virus. It involves multiple organ systems, including the lungs. However, the significance of the lung involvement in SFTS remains unclear. In the present study, we aimed to investigate the relationship between the clinical findings and abnormalities noted in the chest computed tomography (CT) of patients with SFTS. The medical records of 22 confirmed SFTS patients hospitalized in five hospitals in Nagasaki, Japan, between April 2013 and September 2019, were reviewed retrospectively. Interstitial septal thickening and ground-glass opacity (GGO) were the most common findings in 15 (68.1%) and 12 (54.5%) patients, respectively, and lung GGOs were associated with fatalities. The SFTS patients with a GGO pattern were elderly, had a disturbance of the conscious and tachycardia, and had higher c-reactive protein levels at admission (p = 0.009, 0.006, 0.002, and 0.038, respectively). These results suggested that the GGO pattern in patients with SFTS displayed disseminated inflammation in multiple organs and that cardiac stress was linked to higher mortality. Chest CT evaluations may be useful for hospitalized patients with SFTS to predict their severity and as early triage for the need of intensive care

Clinical Differentiation of Severe Fever with Thrombocytopenia Syndrome from Japanese Spotted Fever

Severe fever with thrombocytopenia syndrome (SFTS) and Japanese spotted fever (JSF; a spotted fever group rickettsiosis) are tick-borne zoonoses that are becoming a significant public health threat in Japan and East Asia. Strategies for treatment and infection control differ between the two; therefore, initial differential diagnosis is important. We aimed to compare the clinical characteristics of SFTS and JSF based on symptomology, physical examination, laboratory data, and radiography findings at admission. This retrospective study included patients with SFTS and JSF treated at five hospitals in Nagasaki Prefecture, western Japan, between 2013 and 2020. Data from 23 patients with SFTS and 38 patients with JSF were examined for differentiating factors and were divided by 7:3 into a training cohort and a validation cohort. Decision tree analysis revealed leukopenia (white blood cell [WBC] < 4000/µL) and altered mental status as the best differentiating factors (AUC 1.000) with 100% sensitivity and 100% specificity. Using only physical examination factors, absence of skin rash and altered mental status resulted in the best differentiating factors with AUC 0.871, 71.4% sensitivity, and 90.0% specificity. When treating patients with suspected tick-borne infection, WBC < 4000/µL, absence of skin rash, and altered mental status are very useful to differentiate SFTS from JSF

Identification of Carnitine Transporter CT1 Binding Protein Lin-7 in Nervous System

_L-Carnitine is an essential component of mitochondrial fatty acid b-oxidation in the muscle and may control the acetyl moiety levels in the brain for acetylcholine synthesis. Carnitine transporter 1(CT1)is the high affinity _L-carnitine transporter whose localization was observed in the kidney, testis, liver, skeletal muscle and brain. To clarify the molecular mechanism of carnitine transport, we sought to find the interacting protein that may be related to the transport function of CT1. Using the intracellular C-terminal region of rat CT1 containing PDZ(PSD95/DLG/ZO-1)motif as bait, we performed the yeast two-hybrid screening against rat brain cDNA library. Thirty two positive clones were obtained from the 2.7×10^7 clones screened. One of them was PDZ domain-containing protein Lin-7. We found that Lin-7 interacts specifically with C-termini of CT1:deletion and mutation of the CT1 C-terminal PDZ-motif abolished the interaction with Lin-7 in the yeast two-hybrid assay. In addition, a PDZ domain within Lin-7 associates with the CT1 C-terminal. The association of CT1 with Lin-7 enhanced _L-carnitine transport activities in HEK293 cells although there is no statistical significance. Coexpression of Lin-7 and CT1 is identified in motor neurons of the spinal cord ventral horn together with Lin-2, a binding partner of Lin-7 known to assemble proteins involved in synaptic vesicle exocytosis and synaptic junctions. Therefore, Lin-7 interacts with CT1 and may regulate their subcellular distribution or function in central nervous system

ヒト ジンゾウ ニョウサン トランス ポーター URAT 1 ト スイヨウ セイ ヨード ケイ ゾウエイザイ IODIPAMIDE ノ ソウゴ サヨウ

降圧薬などいくつかの薬剤は本来の薬理作用とは別に尿酸降下作用を持つものがあり,水溶性ヨード系造影剤もその一つでiodipamideやdiatrizoateでの尿酸排泄亢進が報告されていた.長らく不明のままであった腎尿酸輸送機構の分子実体は2002年の腎尿細管尿酸トランスポーターURAT1(Urate Transporter 1)の分子同定によりその理解が飛躍的に進んだ.本研究ではURAT1と水溶性造影剤のiodipamideおよびdiatrizoateの相互作用を検討することで,その尿酸排泄促進作用の分子機序の解明を目的とする.URAT1の尿酸輸送活性の測定にはURAT1安定発現HEK293細胞(HEK-URAT1)細胞を用いた.IodipamideはHEK-URAT1細胞でのRI標識尿酸取込みを著明に阻害した(IC_:1.19±0.08?μM)のに対し,diatrizoateは1?mMまでの範囲では50%以上の阻害作用を示さなかった.1?mMまでのiodipamideはHEK-URAT1細胞の生存率に影響を与えなかった.IodipamideによるURAT1媒介尿酸輸送への阻害作用のキネティクス解析の結果,その阻害は競合阻害であり,阻害定数Ki値は11.03?μMであった.以上より,iodipamideは尿酸トランスポーターURAT1と相互作用をすることを初めて確認できた.このことからiodipamideは細胞外からURAT1の尿酸結合部位に結合し,競合して阻害を行うことで,腎尿細管の経上皮性尿酸再吸収を抑制し,ひいては血清尿酸値を低下させるものと考えられた.Drug-induced hypouricemia has been found in several drugs such as probenecid, benzbromarone and angiotensin II receptor blocker(ARB)losartan. Xray contrast agents such as iodipamide and diatrizoate, used for the intravenous cholangiography and excretory urography, were reported to have uricosuric effct beside their original action. After the molecular identification of renal apical urate transporter URAT1 as an entrance of urate into the epithelial cells of proximal tubules, this protein is thought to be major determinant for renal reabsorption of urate that affect the blood urate levels in human. The purpose of this study is to examine whether iodipamide and diatrizoate act on URAT 1 . In URAT 1 -stably expressing HEK293(HEK-URAT1)cells, iodipamide inhibited [^C] urate uptake dose-dependently(IC_ , 1.19±0.08 μM), while diatrizoate did not. Up to the concentration of 1 mM, iodipamide incubation for 24 hr did not affect the viability of HEK293-URAT1 cells. Lineweaver-Burk plot of the kinetic analysis by URAT1-mediated urate uptake with or without iodipamide indicated that its interaction occurs in a competitive manner(Ki:11.03 μM). These results suggest that uricosuric effect of iodipamide can be explained by the interaction of iodipamide with urate-binding site of URAT1, and the inhibition of urate reabsorption from extracellular side by iodipamide causes uricosuria leading to induce hypouricemia

Three-Color Triple Resonance Spectroscopy of Highly Excited {ng} Rydberg States of NO

Author Institution: Department of Chemistry, Faculty of Science, Tohoku University; Department of Chemistry, Institute for Molecular ScienceLaser multiphoton ionization spectroscopy of highly excited {ng} Rydberg states (n=11-67, $\nu$=0 and 1) of NO was performed. Three-color triple resonance technique was used for rotationally state selective excitation of high {ng} Rydberg states. The observed term values were well reproduced by theoretical calculation based on the long range force model. The experimental evidence for fast autoionization decay in the {ng} Rydberg slates, which has been theoretically predicted, was found at first. Not only autoionization, but also predissociation decay was observed