Scaffold-Hopped Compound Identification by Ligand-Based Approaches with a Prospective Affinity Test.

Scaffold-hopped (SH) compounds are bioactive compounds structurally different from known active compounds. Identifying SH compounds in the ligand-based approaches has been a central issue in medicinal chemistry, and various molecular representations of scaffold hopping have been proposed. However, appropriate representations for SH compound identification remain unclear. Herein, the ability of SH compound identification among several representations was fairly evaluated based on retrospective validation and prospective demonstration. In the retrospective validation, the combinations of two screening algorithms and four two- and three-dimensional molecular representations were compared using controlled data sets for the early identification of SH compounds. We found that the combination of the support vector machine and extended connectivity fingerprint with bond diameter 4 (SVM-ECFP4) and SVM and the rapid overlay of chemical structures (SVM-ROCS) showed a relatively high performance. The compounds that were highly ranked by SVM-ROCS did not share substructures with the active training compounds, while those ranked by SVM-ECFP4 were mostly recombinant. In the prospective demonstration, 93 SH compounds were prepared by screening the Namiki database using SVM-ROCS, targeting ABL1 inhibitors. The primary screening using surface plasmon resonance suggested five active compounds; however, in the competitive binding assays with adenosine triphosphate, no hits were found.

Comparison of safety and effectiveness between etanercept biosimilar LBEC0101 and reference in patients with rheumatoid arthritis in real-world data using the KURAMA cohort.

OBJECTIVES: Biosimilars are anticipated to be widely used in the treatment of rheumatoid arthritis (RA), owing to their cost efficiency; LBEC0101 was the first etanercept (ETN) biosimilar approved in Japan. However, there are limited real-world data comparing its safety and effectiveness with those of a reference product. METHODS: This study used data from the Kyoto University Rheumatoid Arthritis Management Alliance cohort, including patients with RA who received ETN therapy-ETN reference product (ETN-RP) or LBEC0101-between 2015 and 2021. Serum ETN levels were measured using liquid chromatography-tandem mass spectrometry. RESULTS: The 1-year continuation rates of ETN-RP and LBEC0101 were 58.7% and 74.4%, respectively. Effectiveness of treatment was evaluated in 18 patients; both products significantly reduced the 28-joint RA disease activity score and erythrocyte sedimentation rate (DAS28-ESR). Moreover, to determine equivalence, we analysed 11 patients who switched from ETN-RP to LBEC0101; the DAS28-ESR and serum ETN levels before and after switching were not significantly different. CONCLUSIONS: This real-world cohort study confirmed that the biosimilar of ETN, LBEC0101, was comparable to the reference product in terms of continuation rate, effectiveness at initiation of introduction, and effect persistence before and after switching in clinical practice.

Clinical utilization of artificial intelligence-based COVID-19 pneumonia quantification using chest computed tomography - a multicenter retrospective cohort study in Japan.

BACKGROUND: Computed tomography (CT) imaging and artificial intelligence (AI)-based analyses have aided in the diagnosis and prediction of the severity of COVID-19. However, the potential of AI-based CT quantification of pneumonia in assessing patients with COVID-19 has not yet been fully explored. This study aimed to investigate the potential of AI-based CT quantification of COVID-19 pneumonia to predict the critical outcomes and clinical characteristics of patients with residual lung lesions. METHODS: This retrospective cohort study included 1,200 hospitalized patients with COVID-19 from four hospitals. The incidence of critical outcomes (requiring the support of high-flow oxygen or invasive mechanical ventilation or death) and complications during hospitalization (bacterial infection, renal failure, heart failure, thromboembolism, and liver dysfunction) was compared between the groups of pneumonia with high/low-percentage lung lesions, based on AI-based CT quantification. Additionally, 198 patients underwent CT scans 3 months after admission to analyze prognostic factors for residual lung lesions. RESULTS: The pneumonia group with a high percentage of lung lesions (N = 400) had a higher incidence of critical outcomes and complications during hospitalization than the low percentage group (N = 800). Multivariable analysis demonstrated that AI-based CT quantification of pneumonia was independently associated with critical outcomes (adjusted odds ratio [aOR] 10.5, 95% confidence interval [CI] 5.59-19.7), as well as with oxygen requirement (aOR 6.35, 95% CI 4.60-8.76), IMV requirement (aOR 7.73, 95% CI 2.52-23.7), and mortality rate (aOR 6.46, 95% CI 1.87-22.3). Among patients with follow-up CT scans (N = 198), the multivariable analysis revealed that the pneumonia group with a high percentage of lung lesions on admission (aOR 4.74, 95% CI 2.36-9.52), older age (aOR 2.53, 95% CI 1.16-5.51), female sex (aOR 2.41, 95% CI 1.13-5.11), and medical history of hypertension (aOR 2.22, 95% CI 1.09-4.50) independently predicted persistent residual lung lesions. CONCLUSIONS: AI-based CT quantification of pneumonia provides valuable information beyond qualitative evaluation by physicians, enabling the prediction of critical outcomes and residual lung lesions in patients with COVID-19.

Serum Concentrations of Infliximab and IL-6 for Predicting One-Year Discontinuation of Infliximab Treatment Owing to Secondary Non-response in Patients with Rheumatoid Arthritis.

Secondary non-response to infliximab (IFX) occurs in some patients with rheumatoid arthritis (RA). Although therapeutic drug monitoring (TDM) is a useful tool to optimize IFX therapy, it is unclear whether it can help to identify the risk of secondary non-response. This study aimed to explore the utility of serum levels of IFX or other biomarkers to predict IFX discontinuation owing to secondary non-response. A single-center, retrospective study was conducted using the Kyoto University Rheumatoid Arthritis Management Alliance cohort database between 2011 and 2020. Serum IFX levels were measured using liquid chromatography-tandem mass spectrometry. An electrochemiluminescence assay was used to quantify serum levels of tumor necrosis factor-α and interleukin-6 and detect anti-drug antibodies. Eighty-four out of 310 patients were eligible for this study. The cutoff levels of biomarkers were determined by receiver operating characteristic analysis. IFX persistence was similar between groups stratified using IFX levels, tumor necrosis factor-α levels, interleukin-6 levels, and anti-drug antibodies positivity. The group with lower IFX and higher interleukin-6 levels had the worst therapy persistence (p = 0.017) and the most frequent disease worsening (90.0%, p < 0.001). Evaluating both interleukin-6 and IFX levels, not just IFX alone, enabled us to identify patients at risk of discontinuing IFX treatment. These findings support the utility of measuring IFX and interleukin-6 levels for successful maintenance therapy for RA.

Invasion and interaction determine population composition in an open evolving ecological system.

It is well-known that interactions between species determine the population composition in an ecosystem. Conventional studies have focused on fixed population structures to reveal how interactions shape population compositions. However, interaction structures are not fixed but change over time due to invasions. Thus, invasion and interaction play an important role in shaping communities. Despite its importance, however, the interplay between invasion and interaction has not been well explored. Here, we investigate how invasion affects the population composition with interactions in open evolving ecological systems considering generalized Lotka-Volterra-type dynamics. Our results show that the system has two distinct regimes. One is characterized by low diversity with abrupt changes of dominant species in time, appearing when the interaction between species is strong and invasion slowly occurs. On the other hand, frequent invasions can induce higher diversity with slow changes in abundances despite strong interactions. It is because invasion happens before the system reaches its equilibrium, which drags the system from its equilibrium all the time. All species have similar abundances in this regime, which implies that fast invasion induces regime shift. Therefore, whether invasion or interaction dominates determines the population composition.

Spontaneous Improvement of Aortitis Associated with Severe COVID-19 Infection-A Case Report.

Aortitis is a rare complication of the coronavirus disease 2019 (COVID-19) and is often treated empirically with steroids. We present a case of spontaneous resolution of aortitis without treatment. A 65-year-old man was admitted to our intensive care unit for severe COVID-19 pneumonia and underwent rehabilitation in the general ward. On day 12, he developed fever, and on day 13, he developed right cervical pain and increased inflammatory markers. On day 16, a cervical echocardiogram showed vasculitis in the right common carotid artery, and on day 17, computed tomography (CT) of the neck showed thickening of the arterial wall of the right common to the internal carotid arteries. A retrospective assessment of the CT scan on day 12 showed wall thickening from the thoracic aorta to the abdominal aorta, and a diagnosis of aortitis was made. Autoantibody analysis, culture, and magnetic resonance imaging (MRI) of the head and neck showed no abnormalities. During the investigation of the cause of aortitis, the fever and inflammatory reaction spontaneously resolved and the right cervical pain gradually improved. Therefore, the patient was diagnosed with transient COVID-19-related aortitis. To our knowledge, this is the first report describing the spontaneous resolution of COVID-19-related aortitis.

Lysophosphatidylcholine mediates fast decline in kidney function in diabetic kidney disease.

Some patients with diabetic kidney disease (DKD) show a fast progression of kidney dysfunction and are known as a "fast decliner" (FD). Therefore, it is critical to understand pathomechanisms specific for fast decline. Here, we performed a comprehensive metabolomic analysis of patients with stage G3 DKD and identified increased urinary lysophosphatidylcholine (LPC) in fast decline. This was confirmed by quantification of urinary LPC using mass spectrometry and identified urinary LPC containing saturated fatty acids palmitic (16:0) and stearic (18:0) acids was increased in FDs. The upsurge in urinary LPC levels was correlated with a decline in estimated glomerular filtration rate after 2.5 years. To clarify a pathogenic role of LPC in FD, we studied an accelerated rat model of DKD and observed an increase in LPC (16:0) and (18:0) levels in the urine and kidney tubulointerstitium as the disease progressed. These findings suggested that local dysregulation of lipid metabolism resulted in excessive accumulation of this LPC species in the kidney. Our in vitro studies also confirmed LPC-mediated lipotoxicity in cultured proximal tubular cells. LPC induced accumulation of lipid droplets via activation of peroxisome proliferator-activated receptor-δ followed by upregulation of the lipid droplet membrane protein perilipin 2 and decreased autophagic flux, thereby inducing organelle stress and subsequent apoptosis. Thus, LPC (16:0) and (18:0) may mediate a fast progression of DKD and may serve as a target for novel therapeutic approaches.

N-terminus of Etanercept is Proteolytically Processed by Dipeptidyl Peptidase-4.

PURPOSE: Biologics are structurally heterogeneous and can undergo biotransformation in the body. Etanercept (ETN) is a fusion protein composed of a soluble tumor necrosis factor (TNF) receptor and the Fc portion of human immunoglobulin G1. The N-terminus of ETN has a putative sequence cleaved by dipeptidyl peptidase-4 (DPP-4). The purpose of this study was to investigate the biotransformation of ETN in humans and mice and evaluate its effects on functional properties. METHODS: An analytical method using liquid chromatography-mass spectrometry (LC-MS/MS) was established. The N-terminal heterogeneity of ETN was assessed in the serum of patients with rheumatoid arthritis or mice receiving ETN. The in vitro N-terminal truncation was explored using recombinant DPP-4. The binding affinity to TNF-α or TNF-ß was investigated using an in-house enzyme-linked immunosorbent assay. RESULTS: In the formulations, about 90% of ETN had an intact N-terminus, while the N-terminal truncated form was most abundant in the serum of the patients with rheumatoid arthritis and mice. Recombinant human DPP-4 cleaved two amino acids from the N-terminus of ETN in vitro. Sitagliptin, a DPP-4 inhibitor, inhibited N-terminal truncation both in vivo and in vitro. However, N-terminal truncation did not affect the binding ability to TNF-α or TNF-ß and the pharmacokinetics of ETN. ETN biosimilars exhibited similar characteristics to the reference product in vivo and in vitro. CONCLUSIONS: ETN undergoes N-terminal truncation in the body, and DPP-4 cleaves exogenous ETN via N-terminal proteolysis. The application of an MS-based assay will detect novel biotransformation of therapeutic proteins.

A rapid and universal liquid chromatograph-mass spectrometry-based platform, refmAb-Q nSMOL, for monitoring monoclonal antibody therapeutics.

Accurate quantitation of antibodies is critical for development of monoclonal antibody therapeutics (mAbs). Therapeutic drug monitoring has been applied to measure levels of mAbs in clinics for dose adjustment for autoimmune disease. Trough levels of mAbs can be a biomarker for cancer immunotherapy. Thus, the deployment of a rapid and universal platform for mAb monitoring may benefit processes ranging from drug development to clinical practice for a wide spectrum of diseases. However, mAb monitoring often requires development and conduct of an individual ligand binding assay such as ELISA, which is impractical to scale. We streamlined quantitation of antibody therapeutics by a nano-surface and molecular-orientation limited (nSMOL) proteolysis assay using LC-MS with a universal reference antibody (refmAb-Q), for accurate multiplexed quantitation of unique signature peptides derived from mAbs. This innovative refmAb-Q nSMOL platform may provide a practical solution for quantitating an ever-increasing number of mAbs from developmental to clinical use settings.

Mite allergen avoidance decreases allergic symptoms in children in Ishinomaki city of Japan after natural disasters.

OBJECTIVE: We investigated the prevalence of asthma, rhinitis, and atopic dermatitis in children, evaluated the mite allergen levels in their bedding after the Great East Japan Earthquake, and assessed changes in allergic symptoms in children and their families after allergen avoidance practices. METHODS: We performed a survey for the International Study of Asthma and Allergies in Childhood (ISAAC) comprising 1109 children, aged 7-8 years, living in Ishinomaki, Japan. We collected responses from 464 children, and in 2016, measured the level of Dermatophagoides group 1 (Der 1) in the bedding of 202 of these children. The intervention group of children attended at least one allergen avoidance seminar. The levels of Der 1 in their bedding were measured, along with changes in allergic symptoms, in 17 children in 2017 and 14 children in 2018. The nonintervention group comprised children who did not attend an allergen avoidance seminar at any time. RESULTS: Of the 464 children who participated in the ISAAC, 50 (10.8%) reported having asthma, 179 (38.8%) allergic rhinitis, and 126 (27.3%) atopic dermatitis. The average level of Der 1 measured in the bedding of the 202 children in 2016 was 295.8 ng/m2. The levels of Der 1 in the intervention group-but not in the nonintervention group-significantly decreased in 2017 and 2018. The symptoms of asthma, allergic rhinitis, and atopic dermatitis in the children of intervention group and their families decreased after allergen avoidance practices. CONCLUSIONS: Allergen avoidance practices relieved allergic symptoms in school children after the Great East Japan Earthquake.

Androgen receptor signaling-targeted therapy and taxane chemotherapy induce visceral metastasis in castration-resistant prostate cancer.

BACKGROUND: Visceral metastasis (VM), an important poor prognostic factor of prostate cancer (PC), is not commonly observed in castration sensitive status but is often observed after castration-resistant progression. However, the site, timing of emergence, and incidence of VM in castration-resistant patients have not yet been fully elucidated. METHODS: Demographic, surgical, pathological, and follow-up data of PC patients treated at Kanazawa University Hospital between January 2000 and December 2016 were retrospectively analyzed using their medical charts. From this data, risk factors of VM and survival of patients with VM were elucidated. RESULTS: Of 1364 patients, 21 (1.5%) had VM at diagnosis. Of 179 (13.1%) castration-resistant patients, 55 experienced emergence of new VM during treatment course. Incidence of new VM, especially nonlung, such as liver and adrenal metastases, increased significantly in proportion with the number of prescribed treatments. Multivariate analysis revealed that T stage, M stage, age, and treatment history with androgen receptor (AR) signaling-targeted agents and/or taxanes significantly increased the risk of VM. Compared with the group with VM at diagnosis, survival after diagnosis of VM following treatment was significantly shorter. CONCLUSION: Although sequential use of new AR signaling-targeted agents and taxanes for castration-resistant PC (CRPC) is a standard treatment strategy, it often results in development of VM. Elucidating the mechanisms of VM are essential to improve survival in patients with CRPC.

A new flavonoid derivative exerts antitumor effects against androgen-sensitive to cabazitaxel-resistant prostate cancer cells.

BACKGROUND: Our previous report has shown that the flavonoid 2'-hydroxyflavanone (2'-HF) showed inhibition of androgen receptor (AR) activity against androgen-sensitive prostate cancer (PCa) cells, LNCaP, and exhibited antitumor effects against androgen-insensitive PCa cells, PC-3, and DU145. In the present study, we prepared a derivative of 2'-HF, 16MS7F1924, and confirmed the effects of this derivative on PCa cells. METHODS: The antiproliferation effects of 16MS7F1924 were investigated in PCa cells using LNCaP, PC-3, DU145 and docetaxel-resistant and cabazitaxel-resistant cell lines of PC-3-TxR/CxR and DU145-TxR/CxR. Prostate-specific antigen (PSA) and AR expression level in whole cells and the nucleus were confirmed in LNCaP by reverse transcriptase polymerase chain reaction and Western blot analysis. AR activity in LNCaP cells was confirmed by luciferase assay using PSA promoter-driven reporter. To analyze the antiproliferative effects, cell-based assays using flow cytometry, immunocytochemistry, and TUNEL assay as well as Western blot analysis were employed. Furthermore, PC-3, DU145 and each chemoresistant strain of human PCa cells were subcutaneously xenografted. The antitumor effects of 16MS7F1924 were evaluated in vivo. RESULTS: 16MS7F1924 showed antitumor effect on all PCa cells in a dose-dependent manner. 16MS7F1924 reduced the expression of PSA messenger RNA (mRNA) and protein and inhibited AR activity in a dose-dependent manner, while expression of AR protein and mRNA was reduced by 16MS7F1924. 16MS7F1924 induced mitotic catastrophe and apoptosis. Apoptotic cells were increased in a dose-dependent manner, and the apoptosis was mediated through the Akt pathway. Tumor growth was safely and significantly inhibited by both intraperitoneal and oral administration of 16MS7F1924 in vivo. CONCLUSION: 16MS7F1924 had sufficient antitumor activity against androgen-sensitive and cabazitaxel-resistant PCa cells and may be useful as a novel therapeutic agent overcoming hormone- and chemoresistant PCas.

4-Pyridone-3-carboxylic acid as a benzoic acid bioisostere: Design, synthesis, and evaluation of EP300/CBP histone acetyltransferase inhibitors.

Histone acetyltransferases (HATs) play a crucial role in post-translational modification. Among them, overexpression, mutation, or hyperfunction of EP300/CBP has been associated with various cancers. In this study, we identified the novel compound 2-chloro-5-[5-[(E)-[1-(3-chlorophenyl)-3-methyl-5-oxo-pyrazol-4-ylidene]methyl]-2-furyl]benzoic acid (1) as an EP300 HAT inhibitor via virtual screening. Further research has been focused on the design, synthesis, and in vitro biological evaluation of virtual hit derivatives. The studies revealed that 4-pyridone-3-carboxylic acid derivatives exhibited bioisosterism of benzoic acid. Replacement proved effective, providing compounds with similar EP300 HAT-inhibitory activity and improved cell growth-inhibitory activity compared to the benzoic acid analogs. Through these studies, we identified a potent and selective EP300/CBP HAT inhibitor.

Positron emission tomography imaging of renal mitochondria is a powerful tool in the study of acute and progressive kidney disease models.

Mitochondrial dysfunction plays a critical role in the pathogenesis of kidney diseases via ATP depletion and reactive oxygen species overproduction. Nonetheless, few studies have reported the renal mitochondrial status clinical settings, partly due to a paucity of methodologies. Recently, a positron emission tomography probe, 18F-BCPP-BF, was developed to non-invasively visualize and quantitate the renal mitochondrial status in vivo. Here, 18F-BCPP-BF positron emission tomography was applied to three mechanistic kidney disease models in rats: kidney ischemia-reperfusion, 5/6 nephrectomy and anti-glomerular basement membrane glomerulonephritis. In rats with ischemia-reperfusion, a slight decrease in the kidney uptake of 18F-BCPP-BF was accompanied by morphological abnormality of the mitochondria in the proximal tubular cells after three hours of reperfusion, when the kidney function was slightly declined. In 5/6 nephrectomy and rats with anti-glomerular basement membrane glomerulonephritis, the kidney uptake of 18F-BCPP-BF cumulatively decreased with impairment of the kidney function, which was accompanied by a reduction of mitochondrial protein and a pathological tubulointerstitial exacerbation rather than glomerular injury. The 18F-BCPP-BF uptake in the injured kidney was suggested to represent the volume of healthy tubular epithelial cells with normally functioning mitochondria. Thus, this positron emission tomography probe can be a powerful tool for studying the pathophysiological meanings of the mitochondrial status in kidney disease.

Revisiting biomolecular NMR spectroscopy for promoting small-molecule drug discovery.

Recently, there has been increasing interest in new modalities such as therapeutic antibodies and gene therapy at a number of pharmaceutical companies. Moreover, in small-molecule drug discovery at such companies, efforts have focused on hard-to-drug targets such as inhibiting protein-protein interactions. Biomolecular NMR spectroscopy has been used in drug discovery in a variety of ways, such as for the reliable detection of binding and providing three-dimensional structural information for structure-based drug design. The advantages of using NMR spectroscopy have been known for decades (Jahnke in J Biomol NMR 39:87-90, (2007); Gossert and Jahnke in Prog Nucl Magn Reson Spectrosc 97:82-125, (2016)). For tackling hard-to-drug targets and increasing the success in discovering drug molecules, in-depth analysis of drug-target protein interactions performed by biophysical methods will be more and more essential. Here, we review the advantages of NMR spectroscopy as a key technology of biophysical methods and also discuss issues such as using cutting-edge NMR spectrometers and increasing the demand of utilizing conformational dynamics information for promoting small-molecule drug discovery.

Excess sterols disrupt plant cellular activity by inducing stress-responsive gene expression.

Sterols are important lipid constituents of cellular membranes in plants and other organisms. Sterol homeostasis is under strict regulation in plants because excess sterols negatively impact plant growth. HIGH STEROL ESTER 1 (HISE1) functions as a negative regulator of sterol accumulation. If sterol production exceeds a certain threshold, excess sterols are detoxified via conversion to sterol esters by PHOSPHOLIPID STEROL ACYL TRANSFERASE 1 (PSAT1). We previously reported that the Arabidopsis thaliana double mutant hise1-3 psat1-2 shows 1.5-fold higher sterol content than the wild type and consequently a severe growth defect. However, the specific defects caused by excess sterol accumulation in plants remain unknown. In this study, we investigated the effects of excess sterols on plants by analyzing the phenotypes and transcriptomes of the hise1-3 psat1-2 double mutant. Transcriptomic analysis revealed that 435 genes were up-regulated in hise1-3 psat1-2 leaves compared with wild-type leaves. Gene ontology (GO) enrichment analysis revealed that abiotic and biotic stress-responsive genes including RESPONSIVE TO DESICCATION 29B/LOW-TEMPERATURE-INDUCED 65 (RD29B/LTI65) and COLD-REGULATED 15A (COR15A) were up-regulated in hise1-3 psat1-2 leaves compared with wild-type leaves. Expression levels of senescence-related genes were also much higher in hise1-3 psat1-2 leaves than in wild-type leaves. hise1-3 psat1-2 leaves showed early senescence, suggesting that excess sterols induce senescence of leaves. In the absence of sucrose, hise1-3 psat1-2 exhibited defects in seedling growth and root elongation. Together, our data suggest that excess sterol accumulation disrupts cellular activities of vegetative organs including leaves and roots, resulting in multiple damages to plants.

IgG4-related pleural disease in a patient with pulmonary adenocarcinoma under durvalumab treatment: a case report.

BACKGROUND: Immune checkpoint inhibitors (ICIs) are the standard treatment for non-small cell lung cancer. The unique adverse events that can arise after treatment with ICIs are known as immune-related adverse events (irAE). As the number of cases under treatment with ICIs increases, new types of characteristics of irAE have emerged. This case report suggests that IgG4-related pleural disease could occur as an irAE. CASE PRESENTATION: A 64-year-old man was diagnosed with pulmonary adenocarcinoma stage IIIB. Following concurrent chemoradiotherapy, durvalumab was administered every two weeks. The patient complained of dyspnea on effort 4 months after the initiation of durvalumab therapy. Chest CT scans showed mild bilateral pleural effusion 4 months after the initiation of durvalumab therapy, and the amount of pleural effusion increased further at 7 months. Durvalumab was thought to be a potential cause of pleural effusion and was withdrawn after 13 courses of administration over 7 months. The level of serum IgG4 was 2750 mg/dL. The levels of IgG4 of the pleural fluids were 2790 mg/dL on the right side and 2890 mg/dL on the left side at 7 months. Microscopic examination of the pleural biopsy revealed lymphoplasmacytic infiltration with storiform fibrosis. Immunohistochemical examinations showed that the number of IgG4-positive cells was > 20/high power field and the percentage of IgG4-positive to IgG-positive plasma cells was > 50%. Oral prednisolone at a dose of 30 mg/day was initiated, and remarkable clinical improvements were achieved. After 4 months of prednisolone therapy, the level of serum IgG4 decreased to 370 mg/dL and chest CT revealed the disappearance of bilateral pleural effusion. CONCLUSION: This was a case of IgG4-related pleural disease in a patient with pulmonary adenocarcinoma under durvalumab treatment. To our knowledge, this is the first case report of IgG4-related pleural disease as an irAE. It is important to consider the possibility of IgG4-related pleural disease in cases of pleural effusion during the treatment with ICIs.

Glycosyltransferase MDR1 assembles a dividing ring for mitochondrial proliferation comprising polyglucan nanofilaments.

Mitochondria, which evolved from a free-living bacterial ancestor, contain their own genomes and genetic systems and are produced from preexisting mitochondria by binary division. The mitochondrion-dividing (MD) ring is the main skeletal structure of the mitochondrial division machinery. However, the assembly mechanism and molecular identity of the MD ring are unknown. Multi-omics analysis of isolated mitochondrial division machinery from the unicellular alga Cyanidioschyzon merolae revealed an uncharacterized glycosyltransferase, MITOCHONDRION-DIVIDING RING1 (MDR1), which is specifically expressed during mitochondrial division and forms a single ring at the mitochondrial division site. Nanoscale imaging using immunoelectron microscopy and componential analysis demonstrated that MDR1 is involved in MD ring formation and that the MD ring filaments are composed of glycosylated MDR1 and polymeric glucose nanofilaments. Down-regulation of MDR1 strongly interrupted mitochondrial division and obstructed MD ring assembly. Taken together, our results suggest that MDR1 mediates the synthesis of polyglucan nanofilaments that assemble to form the MD ring. Given that a homolog of MDR1 performs similar functions in chloroplast division, the establishment of MDR1 family proteins appears to have been a singular, crucial event for the emergence of endosymbiotic organelles.

[A Patient with Small Cell Lung Cancer Presenting with Paralysis and Intramedullary Metastasis Successfully Treated with Chemotherapy].

A 77-year-old man was diagnosed with small cell lung cancer (SCLC: cT3N3M1b, Stage ⅣA)with bone metastases 1 year and 9 months ago. Although partial response was obtained after 6 courses of chemotherapy with carboplatin(CBDCA)and etoposide(VP-16), multiple brain metastases were observed 5 months after the completion of chemotherapy. The multiple brain metastases completely disappeared after whole brain irradiation. However, the patient experienced lower extremity weakness, predominantly in the left side, 5 months after irradiation. Contrast-enhanced magnetic resonance imaging(MRI) revealed an abnormal nodular lesion at the Th10 level, indicative of intramedullary spinal cord metastasis originating from the SCLC. After the patient was admitted to our hospital, his neurological symptoms progressed rapidly and he began to experience difficulty in standing, along with bowel and bladder dysfunction. Chemotherapy with CBDCA plus VP-16 improved the neurological symptoms, and MRI after 1 course of chemotherapy revealed a decrease in the size of the metastatic lesion in the spinal cord. Although neurological symptoms are common in patients with lung cancer, intramedullary metastases often promote irreversible neurological dysfunction. Herein, we report a patient with SCLC who developed intramedullary spinal cord metastasis and whose neurological symptoms dramatically improved after systemic chemotherapy.

Enrichment of Phosphatidylinositol 4,5-Bisphosphate in the Extra-Invasive Hyphal Membrane Promotes Colletotrichum Infection of Arabidopsis thaliana.

Pathogenic fungi from the genus Colletotrichum form invasive hyphae; the hyphae are surrounded by an extra-invasive hyphal membrane (EIHM), which is continuous with the plant plasma membrane. Although the EIHM plays a crucial role as the interface between plant and fungal cells, its precise function during Colletotrichum infection remains elusive. Here, we show that enrichment of phosphoinositides (PIs) has a crucial role in Colletotrichum infection. We observed the localization of PIs in Arabidopsis thaliana cells infected by A. thaliana-adapted Colletotrichum higginsianum (Ch), and found that phosphatidylinositol 4,5-bisphosphate [PI(4,5)P2] was extremely enriched in the EIHM during Ch infection. We also found that phosphatidylinositol 4-phosphate-5 kinase (PIP5K), which catalyzes production of PI(4,5)P2, also accumulated at the EIHM. The overexpression of PIP5K3 in A. thaliana increased hyphal invasion by Ch. An exocytic factor, EXO84b, was targeted to the EIHM during Ch infection, although endocytic factors such as CLATHRIN LIGHT CHAIN 2 and FLOTILLIN 1 did not. Intriguingly, the interfacial membranes between A. thaliana and powdery mildew- or downy mildew-causing pathogens did not accumulate PI(4,5)P2. These results suggest that Ch could modify the PI(4,5)P2 levels in the EIHM to increase the exocytic membrane/protein supply of the EIHM for successful infection. Our results also suggest that PI(4,5)P2 biosynthesis is a promising target for improved defense against Colletotrichum infection.