Mitigation of acute lung injury by human bronchial epithelial cell-derived extracellular vesicles via ANXA1-mediated FPR signaling

Acute lung injury (ALI) is characterized by respiratory failure resulting from the disruption of the epithelial and endothelial barriers as well as immune system. In this study, we evaluated the therapeutic potential of airway epithelial cell-derived extracellular vesicles (EVs) in maintaining lung homeostasis. We isolated human bronchial epithelial cell-derived EVs (HBEC-EVs), which endogenously express various immune-related surface markers and investigated their immunomodulatory potential in ALI. In ALI cellular models, HBEC-EVs demonstrated immunosuppressive effects by reducing the secretion of proinflammatory cytokines in both THP-1 macrophages and HBECs. Mechanistically, these effects were partially ascribed to nine of the top 10 miRNAs enriched in HBEC-EVs, governing toll-like receptor-NF-κB signaling pathways. Proteomic analysis revealed the presence of proteins in HBEC-EVs involved in WNT and NF-κB signaling pathways, pivotal in inflammation regulation. ANXA1, a constituent of HBEC-EVs, interacts with formyl peptide receptor (FPR)2, eliciting anti-inflammatory responses by suppressing NF-κB signaling in inflamed epithelium, including type II alveolar epithelial cells. In a mouse model of ALI, intratracheal administration of HBEC-EVs reduced lung injury, inflammatory cell infiltration, and cytokine levels. Collectively, these findings suggest the therapeutic potential of HBEC-EVs, through their miRNAs and ANXA1 cargo, in mitigating lung injury and inflammation in ALI patients.

Metabolic Deficiencies Underlie Plasmacytoid Dendritic Cell Exhaustion After Viral Infection

Type I Interferons (IFN-I) are central to host protection against viral infections 1 . While any cell can produce IFN-I, Plasmacytoid Dendritic Cells (pDCs) make greater quantities and more varieties of these cytokines than any other cell type 2 . However, following an initial burst of IFN- I, pDCs lose their exceptional IFN-I production capacity and become "exhausted", a phenotype that associates with enhanced susceptibility to secondary infections 3-5 . Despite this apparent cost for the host, pDC exhaustion is conserved across multiple species and viral infections, but the underlying mechanisms and the potential evolutionary advantages are not well understood. Here we characterize pDC exhaustion and demonstrate that it is associated with a reduced capacity of pDCs to engage both oxidative and glycolytic metabolism. Mechanistically, we identify lactate dehydrogenase B (LDHB) as a novel positive regulator of pDC IFN-I production in mice and humans, show that LDHB deficiency is associated with suppressed IFN-I production, pDC metabolic capacity, and viral control following a viral infection, and demonstrate that preservation of LDHB expression is sufficient to partially restore exhausted pDC function in vitro and in vivo . Furthermore, restoring LDHB in vivo in exhausted pDCs increased IFNAR dependent infection- associated pathology. Therefore, our work identifies a novel and conserved mechanism for balancing immunity and pathology during viral infections, while also providing insight into the highly preserved but previously unexplained phenomenon of pDC exhaustion.

Effects of empagliflozin on progression of chronic kidney disease: a prespecified secondary analysis from the empa-kidney trial

BACKGROUND

Sodium-glucose co-transporter-2 (SGLT2) inhibitors reduce progression of chronic kidney disease and the risk of cardiovascular morbidity and mortality in a wide range of patients. However, their effects on kidney disease progression in some patients with chronic kidney disease are unclear because few clinical kidney outcomes occurred among such patients in the completed trials. In particular, some guidelines stratify their level of recommendation about who should be treated with SGLT2 inhibitors based on diabetes status and albuminuria. We aimed to assess the effects of empagliflozin on progression of chronic kidney disease both overall and among specific types of participants in the EMPA-KIDNEY trial.

METHODS

EMPA-KIDNEY, a randomised, controlled, phase 3 trial, was conducted at 241 centres in eight countries (Canada, China, Germany, Italy, Japan, Malaysia, the UK, and the USA), and included individuals aged 18 years or older with an estimated glomerular filtration rate (eGFR) of 20 to less than 45 mL/min per 1·73 m2, or with an eGFR of 45 to less than 90 mL/min per 1·73 m2 with a urinary albumin-to-creatinine ratio (uACR) of 200 mg/g or higher. We explored the effects of 10 mg oral empagliflozin once daily versus placebo on the annualised rate of change in estimated glomerular filtration rate (eGFR slope), a tertiary outcome. We studied the acute slope (from randomisation to 2 months) and chronic slope (from 2 months onwards) separately, using shared parameter models to estimate the latter. Analyses were done in all randomly assigned participants by intention to treat. EMPA-KIDNEY is registered at ClinicalTrials.gov, NCT03594110.

FINDINGS

Between May 15, 2019, and April 16, 2021, 6609 participants were randomly assigned and then followed up for a median of 2·0 years (IQR 1·5-2·4). Prespecified subgroups of eGFR included 2282 (34·5%) participants with an eGFR of less than 30 mL/min per 1·73 m2, 2928 (44·3%) with an eGFR of 30 to less than 45 mL/min per 1·73 m2, and 1399 (21·2%) with an eGFR 45 mL/min per 1·73 m2 or higher. Prespecified subgroups of uACR included 1328 (20·1%) with a uACR of less than 30 mg/g, 1864 (28·2%) with a uACR of 30 to 300 mg/g, and 3417 (51·7%) with a uACR of more than 300 mg/g. Overall, allocation to empagliflozin caused an acute 2·12 mL/min per 1·73 m2 (95% CI 1·83-2·41) reduction in eGFR, equivalent to a 6% (5-6) dip in the first 2 months. After this, it halved the chronic slope from -2·75 to -1·37 mL/min per 1·73 m2 per year (relative difference 50%, 95% CI 42-58). The absolute and relative benefits of empagliflozin on the magnitude of the chronic slope varied significantly depending on diabetes status and baseline levels of eGFR and uACR. In particular, the absolute difference in chronic slopes was lower in patients with lower baseline uACR, but because this group progressed more slowly than those with higher uACR, this translated to a larger relative difference in chronic slopes in this group (86% [36-136] reduction in the chronic slope among those with baseline uACR <30 mg/g compared with a 29% [19-38] reduction for those with baseline uACR ≥2000 mg/g; ptrend<0·0001).

INTERPRETATION

Empagliflozin slowed the rate of progression of chronic kidney disease among all types of participant in the EMPA-KIDNEY trial, including those with little albuminuria. Albuminuria alone should not be used to determine whether to treat with an SGLT2 inhibitor.

FUNDING

Boehringer Ingelheim and Eli Lilly.

Impact of primary kidney disease on the effects of empagliflozin in patients with chronic kidney disease: secondary analyses of the EMPA-KIDNEY trial

BACKGROUND

The EMPA-KIDNEY trial showed that empagliflozin reduced the risk of the primary composite outcome of kidney disease progression or cardiovascular death in patients with chronic kidney disease mainly through slowing progression. We aimed to assess how effects of empagliflozin might differ by primary kidney disease across its broad population.

METHODS

EMPA-KIDNEY, a randomised, controlled, phase 3 trial, was conducted at 241 centres in eight countries (Canada, China, Germany, Italy, Japan, Malaysia, the UK, and the USA). Patients were eligible if their estimated glomerular filtration rate (eGFR) was 20 to less than 45 mL/min per 1·73 m2, or 45 to less than 90 mL/min per 1·73 m2 with a urinary albumin-to-creatinine ratio (uACR) of 200 mg/g or higher at screening. They were randomly assigned (1:1) to 10 mg oral empagliflozin once daily or matching placebo. Effects on kidney disease progression (defined as a sustained ≥40% eGFR decline from randomisation, end-stage kidney disease, a sustained eGFR below 10 mL/min per 1·73 m2, or death from kidney failure) were assessed using prespecified Cox models, and eGFR slope analyses used shared parameter models. Subgroup comparisons were performed by including relevant interaction terms in models. EMPA-KIDNEY is registered with ClinicalTrials.gov, NCT03594110.

FINDINGS

Between May 15, 2019, and April 16, 2021, 6609 participants were randomly assigned and followed up for a median of 2·0 years (IQR 1·5-2·4). Prespecified subgroupings by primary kidney disease included 2057 (31·1%) participants with diabetic kidney disease, 1669 (25·3%) with glomerular disease, 1445 (21·9%) with hypertensive or renovascular disease, and 1438 (21·8%) with other or unknown causes. Kidney disease progression occurred in 384 (11·6%) of 3304 patients in the empagliflozin group and 504 (15·2%) of 3305 patients in the placebo group (hazard ratio 0·71 [95% CI 0·62-0·81]), with no evidence that the relative effect size varied significantly by primary kidney disease (pheterogeneity=0·62). The between-group difference in chronic eGFR slopes (ie, from 2 months to final follow-up) was 1·37 mL/min per 1·73 m2 per year (95% CI 1·16-1·59), representing a 50% (42-58) reduction in the rate of chronic eGFR decline. This relative effect of empagliflozin on chronic eGFR slope was similar in analyses by different primary kidney diseases, including in explorations by type of glomerular disease and diabetes (p values for heterogeneity all >0·1).

INTERPRETATION

In a broad range of patients with chronic kidney disease at risk of progression, including a wide range of non-diabetic causes of chronic kidney disease, empagliflozin reduced risk of kidney disease progression. Relative effect sizes were broadly similar irrespective of the cause of primary kidney disease, suggesting that SGLT2 inhibitors should be part of a standard of care to minimise risk of kidney failure in chronic kidney disease.

FUNDING

Boehringer Ingelheim, Eli Lilly, and UK Medical Research Council.

Previous fracture and subsequent fracture risk: a meta-analysis to update FRAX

A large international meta-analysis using primary data from 64 cohorts has quantified the increased risk of fracture associated with a previous history of fracture for future use in FRAX.

INTRODUCTION

The aim of this study was to quantify the fracture risk associated with a prior fracture on an international basis and to explore the relationship of this risk with age, sex, time since baseline and bone mineral density (BMD).

METHODS

We studied 665,971 men and 1,438,535 women from 64 cohorts in 32 countries followed for a total of 19.5 million person-years. The effect of a prior history of fracture on the risk of any clinical fracture, any osteoporotic fracture, major osteoporotic fracture, and hip fracture alone was examined using an extended Poisson model in each cohort. Covariates examined were age, sex, BMD, and duration of follow-up. The results of the different studies were merged by using the weighted β-coefficients.

RESULTS

A previous fracture history, compared with individuals without a prior fracture, was associated with a significantly increased risk of any clinical fracture (hazard ratio, HR = 1.88; 95% CI = 1.72-2.07). The risk ratio was similar for the outcome of osteoporotic fracture (HR = 1.87; 95% CI = 1.69-2.07), major osteoporotic fracture (HR = 1.83; 95% CI = 1.63-2.06), or for hip fracture (HR = 1.82; 95% CI = 1.62-2.06). There was no significant difference in risk ratio between men and women. Subsequent fracture risk was marginally downward adjusted when account was taken of BMD. Low BMD explained a minority of the risk for any clinical fracture (14%), osteoporotic fracture (17%), and for hip fracture (33%). The risk ratio for all fracture outcomes related to prior fracture decreased significantly with adjustment for age and time since baseline examination.

CONCLUSION

A previous history of fracture confers an increased risk of fracture of substantial importance beyond that explained by BMD. The effect is similar in men and women. Its quantitation on an international basis permits the more accurate use of this risk factor in case finding strategies.

A Risk Prediction Model for Severe Radiation Induced Lymphopenia in Patients with Pancreatic Cancer Treated with Concurrent Chemoradiotherapy

PURPOSE/OBJECTIVE(S)

In pancreatic cancer, radiation induced lymphopenia (RIL) is associated with a poor prognosis. However, normal tissue complication probability (NTCP) models predicting RIL in pancreatic cancer treated with concurrent chemoradiotherapy (CCRT) have yet to be developed. This study aims to develop a least absolute shrinkage and selection operator (LASSO)-based multivariate NTCP model to predict severe RIL in patients with pancreatic cancer during CCRT and to validate the model internally.

MATERIALS/METHODS

We retrospectively reviewed patients with localized pancreatic cancer who underwent CCRT using three-dimensional conformal radiation therapy from 2013 to 2021. The exclusion criteria were patients with distant metastasis; patients who did not complete RT due to tumor progression; patients who did not have absolute lymphocyte count (ALC) data available before or during RT. An ALC of < 0.5 K/μL during CCRT was defined as severe RIL. A NTCP model of severe RIL was developed by LASSO-based multivariate analysis. We used age, sex, Karnofsky performance status, maximum tumor size, carbohydrate antigen 19-9 level before RT, ALC before RT, volume of planning target volume (PTV), and dosimetric parameters for surrounding organs (including spleen, vertebrae, liver, bilateral kidneys, gastrointestinal tracts) as variables for LASSO. In addition, internal validation was performed by the bootstrap method. The predictive performance of the model was evaluated by the area under the curve (AUC) of the receiver operating characteristic curve and scaled Brier score.

RESULTS

Of the 131 patients included in the study, the median age was 68 years (range, 42-84), and 55% were male. The median ALC before RT was 1.37 K/µL (0.52-3.50). The median PTV volume was 315.4 ml (86.3-1079.3). The median dose of radiotherapy was 50.4 Gy (16.2-50.4), with 1.8 Gy per fraction. Combination chemotherapy was S-1 in 99 cases (75.6%) and gemcitabine in 32 cases (24.4%). Induction chemotherapy before CCRT was performed in 39 patients (29.8%). Severe RIL was observed in 84 (63.6%) patients. The LASSO showed that low baseline ALC (p = 0.0002), large PTV volume (p < 0.0001), and a large kidney V5 defined as the percentage of bilateral kidneys receiving 5 Gy or more (p = 0.0338) were selected as parameters of the prediction model for severe RIL (AUC = 0.917) and scaled Brier score was 0.511. As a result of internal validation by the bootstrap method, the average AUC was 0.918 (95% confidence interval, 0.849-0.954).

CONCLUSION

Severe RIL occurred frequently during CCRT for pancreatic cancer, and a NTCP model for severe RIL developed and validated internally in this study showed good predictive performance. External validation is needed before this NTCP model can be used as a benchmark for treatment planning to reduce the risk of severe RIL and for considering future treatment approaches.

Exploratory analysis to predict pneumonitis during durvalumab consolidation therapy for patients with locally advanced non-small cell lung cancer from proteomic profiling of circulating extracellular vesicles

BACKGROUND

Risk factors for predicting pneumonitis during durvalumab consolidation after chemoradiotherapy (CRT) in locally advanced non-small cell lung cancer (LA-NSCLC) are still lacking. Extracellular vesicles (EVs) play a crucial role in intercellular communication and are potential diagnostic tools for various diseases.

METHODS

We retrospectively collected predurvalumab treatment serum samples from patients treated with durvalumab for LA-NSCLC, isolated EVs using anti-CD9 and anti-CD63 antibodies, and performed proteomic analyses. We examined EV proteins that could predict the development of symptomatic pneumonitis (SP) during durvalumab treatment. Potential EV-protein biomarkers were validated in an independent cohort.

RESULTS

In the discovery cohort, 73 patients were included, 49 with asymptomatic pneumonitis (AP) and 24 with SP. Of the 5797 proteins detected in circulating EVs, 33 were significantly elevated (fold change [FC] > 1.5, p < 0.05) in the SP group, indicating enrichment of the nuclear factor kappa B (NF-κB) pathway. Patients with high levels of EV-RELA, an NF-κB subunit, had a higher incidence of SP than those with low levels of EV-RELA (53.8% vs. 13.4%, p = 0.0017). In the receiver operating characteristic analysis, EV-RELA demonstrated a higher area under the curve (AUC) than lung V20 (0.76 vs. 0.62) and was identified as an independent risk factor in the multivariate logistic regression analysis (p = 0.008, odds ratio 7.72). Moreover, high EV-RELA was also a predictor of SP in the validation cohort comprising 43 patients (AUC of 0.80).

CONCLUSIONS

Circulating EV-RELA may be a predictive marker for symptomatic pneumonitis in patients with LA-NSCLC treated with durvalumab.

Divergent roles of the Hippo pathway in the pathogenesis of idiopathic pulmonary fibrosis: tissue homeostasis and fibrosis

Idiopathic pulmonary fibrosis (IPF) is a progressive aging-related lung disease with a poor prognosis. Despite extensive research, the cause of IPF remains largely unknown and treatment strategies are limited. Proposed mechanisms of the pathogenesis of IPF are a combination of excessive accumulation of the extracellular matrix and dysfunctional lung tissue regeneration. Epithelial cell dysfunction, in addition to fibroblast activation, is considered a key process in the progression of IPF. Epithelial cells normally maintain homeostasis of the lung tissue through regulated proliferation, differentiation, cell death, and cellular senescence. However, various stresses can cause repetitive damage to lung epithelial cells, leading to dysfunctional regeneration and acquisition of profibrotic functions. The Hippo pathway is a central signaling pathway that maintains tissue homeostasis and plays an essential role in fundamental biological processes. Dysregulation of the Hippo pathway has been implicated in various diseases, including IPF. However, the role of the Hippo pathway in the pathogenesis of IPF remains unclear, particularly given the pathway's opposing effects on the 2 key pathogenic mechanisms of IPF: epithelial cell dysfunction and fibroblast activation. A deeper understanding of the relationship between the Hippo pathway and the pathogenesis of IPF will pave the way for novel Hippo-targeted therapies.

Fibroblast-derived Extracellular Vesicles Induce Lung Cancer Progression in the Idiopathic Pulmonary Fibrosis Microenvironment

Idiopathic pulmonary fibrosis (IPF) is a progressive aging-related lung disease associated with increased lung cancer risk. Although previous studies have shown that IPF worsens the survival of patients with lung cancer, whether IPF independently affects cancer malignancy and prognosis remains inconclusive. Extracellular vesicles (EVs) have recently emerged as active carriers of molecular biomarkers and mediators of intercellular communication in lung homeostasis and pathogenesis. EV cargo-mediated fibroblast-tumor cell communication might participate in the development and progression of lung cancer by modulating various signaling pathways. In this study, we examined the impact of lung fibroblast (LF)-derived EVs on non-small cell lung cancer (NSCLC) malignancy in the IPF microenvironment. Here, we showed that LFs derived from patients with IPF have phenotypes of myofibroblast differentiation and cellular senescence. Furthermore, we found that IPF LF-derived EVs have markedly altered microRNA compositions and exert proproliferative functions on NSCLC cells. Mechanistically, the phenotype was attributed mainly to the enrichment of miR-19a in IPF LF-derived EVs. As a downstream signaling pathway, mir-19a in IPF LF-derived EVs regulates ZMYND11-mediated c-Myc activation in NSCLC, potentially contributing to the poor prognosis of patients with NSCLC with IPF. Our discoveries provide novel mechanistic insights for understanding lung cancer progression in the IPF microenvironment. Accordingly, blocking the secretion of IPF LF-derived EV miR-19a and their signaling pathways is a potential therapeutic strategy for managing IPF and lung cancer progression.

A Rare Case of Paratesticular Cystadenoma with Ovarian Stroma Found by Scrotal Ultrasound on a Cirrhotic Patient with Elevated Alpha-fetoprotein

Introduction/Objective

Paratesticular cystadenoma with ovarian stroma is a rare benign cyst-forming neoplasm with less than 10 cases reported in the literature. Typically, it presents in men aged 11 to 68 years (average 30) and is asymptomatic. The tumor is hypothesized to represent the efferent ductulus undergoing metaplastic change, the vestigial remnants of Mullerian duct, or mesothelium of the tunica vaginalis. Most tumors are considered benign, but a few cases of malignant transformation have been reported.

Methods/Case Report

We present a case of a 54-year-old male with a history of cirrhosis and elevated alpha-fetoprotein (17.85 ng/ML) who was found to have a paratesticular mass by scrotal ultrasound. Clinical history was obtained from review of electronic medical record. CD10 (Novocastra Clone 56C6) and progesterone receptor (PR) (Leica Clone 16) Immunoperoxidase stains were performed following the vendor recommendations. Surgical excision revealed a 0.6-cm polypoid nodule on tunica albuginea that was entirely submitted. Microscopically, the tumor was comprised of cystic spaces lined by cuboidal epithelium identical to that of the Fallopian tubes. There was a sparse spindle-shaped stroma underlying the epithelium similar to ovarian stroma. No nuclear atypia or mitosis was found. Immunoperoxidase stains showed the epithelium was positive for PR, and the stroma was positive for CD10. No evidence of germ cell tumor was identified.

Results (if a Case Study enter NA)

NA.

Conclusion

Characteristic histologic and immunophenotypic findings can aid in the diagnosis of paratesticular cystadenoma with ovarian stroma. Surgical resection for histological confirmation and long-term monitoring for the potential recurrence and metastatic spread are required.

Update of the fracture risk prediction tool FRAX: a systematic review of potential cohorts and analysis plan

We describe the collection of cohorts together with the analysis plan for an update of the fracture risk prediction tool FRAX with respect to current and novel risk factors. The resource comprises 2,138,428 participants with a follow-up of approximately 20 million person-years and 116,117 documented incident major osteoporotic fractures.

INTRODUCTION

The availability of the fracture risk assessment tool FRAX® has substantially enhanced the targeting of treatment to those at high risk of fracture with FRAX now incorporated into more than 100 clinical osteoporosis guidelines worldwide. The aim of this study is to determine whether the current algorithms can be further optimised with respect to current and novel risk factors.

METHODS

A computerised literature search was performed in PubMed from inception until May 17, 2019, to identify eligible cohorts for updating the FRAX coefficients. Additionally, we searched the abstracts of conference proceedings of the American Society for Bone and Mineral Research, European Calcified Tissue Society and World Congress of Osteoporosis. Prospective cohort studies with data on baseline clinical risk factors and incident fractures were eligible.

RESULTS

Of the 836 records retrieved, 53 were selected for full-text assessment after screening on title and abstract. Twelve cohorts were deemed eligible and of these, 4 novel cohorts were identified. These cohorts, together with 60 previously identified cohorts, will provide the resource for constructing an updated version of FRAX comprising 2,138,428 participants with a follow-up of approximately 20 million person-years and 116,117 documented incident major osteoporotic fractures. For each known and candidate risk factor, multivariate hazard functions for hip fracture, major osteoporotic fracture and death will be tested using extended Poisson regression. Sex- and/or ethnicity-specific differences in the weights of the risk factors will be investigated. After meta-analyses of the cohort-specific beta coefficients for each risk factor, models comprising 10-year probability of hip and major osteoporotic fracture, with or without femoral neck bone mineral density, will be computed.

CONCLUSIONS

These assembled cohorts and described models will provide the framework for an updated FRAX tool enabling enhanced assessment of fracture risk (PROSPERO (CRD42021227266)).

Extracellular vesicles in idiopathic pulmonary fibrosis: pathogenesis and therapeutics

Idiopathic pulmonary fibrosis (IPF) is a progressive lung disease that occurs due to increased fibrosis of lung tissue in response to chronic injury of the epithelium. Therapeutic options for IPF remain limited as current therapies only function to decrease disease progression. Recently, extracellular vesicles (EVs), including exosomes and microvesicles, have been recognized as paracrine communicators through the component cargo. The population of cell-specific microRNAs and proteins present in EVs can regulate gene expressions of recipient cells, resulting in modulation of biological activities. EV cargoes reflect cell types and their physiological and pathological status of donor cells. Many current researches have highlighted the functions of EVs on the epithelial phenotype and fibroproliferative response in the pathogenesis of IPF. Furthermore, some native EVs could be used as a cell-free therapeutic approach for IPF as vehicles for drug delivery, given their intrinsic biocompatibility and specific target activity. EV-based therapies have been proposed as a new potential alternative to cell-based approaches. The advantage is that EVs, depending on their source, may be less immunogenic than their parental cells, likely due to a lower abundance of transmembrane proteins such as major histocompatibility complex (MHC) proteins on the surface. In the last decade, mesenchymal stem cell (MSC)-derived EVs have been rapidly developed as therapeutic products ready for clinical trials against various diseases. Considering EV functional complexity and heterogeneity, there is an urgent need to establish refined systemic standards for manufacturing processes and regulatory requirements of these medicines. This review highlights the EV-mediated cellular crosstalk involved in IPF pathogenesis and discusses the potential for EV-based therapeutics as a novel treatment modality for IPF.

Multiple encephalopathy syndrome: a case of a novel radiological subtype of acute encephalopathy in childhood

INTRODUCTION

This report presents the case of a novel subtype of acute encephalopathy syndrome in childhood found in a patient with influenza type A infection; the patient exhibited evident magnetic resonance imaging (MRI) findings.

CASE REPORT

A 4-year-old boy was transferred to our hospital for prolonged (lasting 60 min) status epilepticus with influenza encephalopathy. Mild brain hypothermia therapy was applied for 72 h, followed by targeted temperature management for 96 h with mechanical ventilation in the intensive care unit. Moreover, methylprednisolone pulse therapy and immunoglobulin therapy were administered. One month after the treatment, his physical status recovered such that he was able to run, take food orally, communicate verbally, and successfully return to kindergarten. Interestingly, serial MRI studies revealed findings that were compatible with 1) acute necrotizing encephalopathy (ANE), 2) mild encephalitis/encephalopathy with a reversible splenial lesion (MERS type II), 3) acute cerebellitis, and 4) acute encephalopathy with biphasic seizures and late reduced diffusion (AESD) on days 2, 4, 7, and 16, respectively.

CONCLUSIONS

To the best of our knowledge, these significant MRI findings associated with acute encephalopathy have never been reported. Thus, herein, we propose the new term radiological "multiple encephalopathy syndrome (MES)" based on our case of acute encephalopathy in childhood.

Involvement of Parkin-mediated mitophagy in the pathogenesis of chronic obstructive pulmonary disease-related sarcopenia

BACKGROUND

Sarcopenia is characterized by the loss of skeletal muscle mass and strength and is associated with poor prognosis in patients with chronic obstructive pulmonary disease (COPD). Cigarette smoke (CS) exposure, a major cause for COPD, induces mitochondrial damage, which has been implicated in sarcopenia pathogenesis. The current study sought to examine the involvement of insufficient Parkin-mediated mitophagy, a mitochondrion-selective autophagy, in the mechanisms by which dysfunctional mitochondria accumulate with excessive reactive oxygen species (ROS) production in the development of COPD-related sarcopenia.

METHODS

The involvement of Parkin-mediated mitophagy was examined using in vitro models of myotube formation, in vivo CS-exposure model using Parkin^-/- mice, and human muscle samples from patients with COPD-related sarcopenia.

RESULTS

Cigarette smoke extract (CSE) induced myotube atrophy with concomitant 30% reduction in Parkin expression levels (P < 0.05). Parkin-mediated mitophagy regulated myotube atrophy by modulating mitochondrial damage and mitochondrial ROS production. Increased mitochondrial ROS was responsible for myotube atrophy by activating Muscle Ring Finger 1 (MuRF-1)-mediated myosin heavy chain (MHC) degradation. Parkin^-/- mice with prolonged CS exposure showed enhanced limb muscle atrophy with a 31.7% reduction in limb muscle weights (P < 0.01) and 2.3 times greater MuRF-1 expression (P < 0.01) compared with wild-type mice with concomitant accumulation of damaged mitochondria and oxidative modifications in 4HNE expression. Patients with COPD-related sarcopenia exhibited significantly reduced Parkin but increased MuRF-1 protein levels (35% lower and 2.5 times greater protein levels compared with control patients, P < 0.01 and P < 0.05, respectively) and damaged mitochondria accumulation demonstrated in muscles. Electric pulse stimulation-induced muscle contraction prevented CSE-induced MHC reduction by maintaining Parkin levels in myotubes.

CONCLUSIONS

Taken together, COPD-related sarcopenia can be attributed to insufficient Parkin-mediated mitophagy and increased mitochondrial ROS causing enhanced muscle atrophy through MuRF-1 activation, which may be at least partly preventable through optimal physical exercise.

Extracellular vesicle-mediated cellular crosstalk in lung repair, remodelling and regeneration

The unperturbed lung is highly quiescent, with a remarkably low level of cell turnover. However, once damaged, the lung shows an extensive regenerative capacity, with resident progenitor cell populations re-entering the cell cycle and differentiating to promote repair. This quick and dramatic repair response requires interactions among more than 40 different cell lineages in the lung, and defects in any of these processes can lead to various lung pathologies. Understanding the mechanisms of interaction in lung injury, repair and regeneration thus has considerable practical and therapeutic implications. Moreover, therapeutic strategies for replacing lung progenitor cells and their progeny through cell therapy have gained increasing attention. In the last decade, extracellular vesicles (EVs), including exosomes, have been recognised as paracrine mediators through the transfer of biological cargo. Recent work has revealed that EVs are involved in lung homeostasis and diseases. In addition, EVs derived from specific cells or tissues have proven to be a promising cell-free modality for the treatment of lung diseases. This review highlights the EV-mediated cellular crosstalk that regulates lung homeostasis and discusses the potential of EV therapeutics for lung regenerative medicine.

Diagnostic value of simultaneous 99mTc-sestamibi/123I-BMIPP imaging parameters for predicting the improvement of left ventricular wall motion after acute myocardial infarction using CZT SPECT system

Background

Although the presence of 99mTc-sestamibi/123I-BMIPP-mismatch, the reverse redistribution (RR) of 99mTc-sestamibi and RR of 123I-BMIPP in patients with acute myocardial infarction (AMI) are known to significant markers for predicting the improvement of LV wall motion in the infarcted territory in chronic phase, few studies were performed to analyze them by simultaneous dual-isotope imaging using cadmium-zinc-telluride (CZT) SPECT system.

Purpose

The purpose of this study was to evaluate whether the presence of 99mTc-sestamibi/123I-BMIPP-mismatch or RR of 99mTc-sestamibi, RR of 123I-BMIPP make better prediction of the improvement of LV wall motion in the infarcted territory.

Methods

We evaluated 42 consecutive patients with AMI who had undergone both dual-isotope SPECT in acute phase and stress myocardial SPECT using 99mTc-tracers in chronic phase by Discovery NM530c. The presence of 99mTc-sestamibi/123I-BMIPP-mismatch, RR of 99mTc-sestamibi and RR of 123I-BMIPP were determined using traditional definition. The improvement of LV wall motion in the infarcted territory from acute phase to chronic phase was assessed using QGS.

Results

Of 42 patients, the improvement of LV wall motion in the infarcted territory from acute phase to chronic phase was found in 29 patients. The presence of 99mTc-sestamibi/123I-BMIPP-mismatch and RR of 99mTc-sestamibi and RR of 123I-BMIPP were significantly linked to predict the improvement of LV wall motion (p=0.0001, p=0.0001 and p=0.002, respectively). To predict the improvement of LV wall motion in the infarcted territory in chronic phase, the presence of 99mTc-sestamibi/123I-BMIPP-mismatch showed sensitivity of 93%, specificity of 85% and accuracy of 91%, while RR of 99mTc-sestamibi and RR of 123I-BMIPP had sensitivities of 72%, 48%, specificities of 85%, 100% and accuracies of 76%, 64%, respectively. The multivariate discriminant analysis revealed that the combination of 99mTc-sestamibi/123I-BMIPP-mismatch, RR of 99mTc-sestamibi and RR of 123I-BMIPP best predicted the improvement of LV wall motion in the infarcted territory in chronic phase with sensitivity of 93%, specificity of 85% and accuracy of 91% (chi-square=40.6), compared with RR of 99mTc-sestamibi and RR of 123I-BMIPP only (sensitivity 79%, specificity 85% and accuracy of 81%, chi-square=16.9).

Conclusions

The addition of 99mTc-sestamibi/123I-BMIPP-mismatch on RR of 99mTc-sestamibi and RR of 123I-BMIPP in patients with AMI, help better predict the improvement of LV wall motion in the infarcted territory in chronic phase.

Funding Acknowledgement

Type of funding sources: None.

Intracellular localization of AMP deaminase and its novel role in BCAA and lipid metabolism in diabetic cardiomyopathy

Background

A metabolomic study in the human heart suggested a pivotal role of amino acid (AA) metabolism in fatty acid oxidation, which is dysregulated in type 2 diabetes mellitus (T2DM) and heart failure. We previously reported that aberrant up-regulation of AMP deaminase 3 (AMPD3) impairs cardiac energetics in T2DM hearts, and AMPD3 was recently shown to be activated by fasting and to promote AA metabolism and fatty acid oxidation in skeletal muscle. A sodium glucose cotransporter 2 inhibitor (SGLT2i) has been shown to augment systemic AA metabolism, but its effect on cardiac AA metabolism remains unknown.

Purpose

We hypothesized that AMPD3 has a role in AA and lipid metabolism in cardiomyocytes and that the protective effect of an SGLT2i in diabetic hearts is mediated by modification of AA and lipid metabolism.

Methods and results

Proteomic analyses of AMPD3 immunoprecipitates in rat hearts revealed that AMPD3 interacted with the E1α and E2 components of the BCKDH complex, a rate-limiting enzyme of branched-chain AA (BCAA) catabolism. Immunoblotting using subcellular fractions revealed that BCKDH localized not only in the mitochondria matrix but also in the cytosol and endoplasmic reticulum (ER) and that AMPD3 interacted with BCKDH in the cytosol and ER. Despite comparable expression of BCKDH components and phosphorylation of E1α at Ser293, significant accumulation of BCAA was observed in T2DM rats (OLETF; 317±30 nmol/g) compared to that in control rats (LETO; 213±16 nmol/g), and the accumulation of BCAA was accompanied by up-regulation of AMPD3 in the cytosol and ER by 98% and 231%, respectively. In cardiomyocytes, disruption of BCAA catabolism by knockdown of BCKDH-E1α resulted in a 5.8-fold increase in AMPD3 at the transcriptional level and blunted lipid droplet biogenesis in response to a long-chain fatty acid challenge. Next, myocardial infarction (MI) was induced in LETO and OLETF pretreated with empagliflozin (10 mg/kg/day, 14 days) or a vehicle. Pathway analysis of cardiac metabolites revealed arginine biosynthesis and BCAA metabolism as the most significantly changed pathways with empagliflozin, with BCAA (791±187 nmol/g), glutamate, glutamine and urea being significantly increased. Empagliflozin restored myocardial ATP and survival after MI in OLETF to levels comparable to those in LETO. Electron microscopy showed a significantly higher prevalence of myocardium lipid droplets in OLETF, which was further increased by empagliflozin.

Conclusions

The results support the hypotheses that imbalance of extra-mitochondrial AMPD3-BCKDH interaction underlies dysregulated BCAA metabolism in T2DM hearts and that activation of cardiac AA metabolism by an SGLT2i normalizes fatty acid overload through sequestration into intracellular lipid droplets.

Funding Acknowledgement

Type of funding sources: Foundation. Main funding source(s): Boehringer Ingelheim

Role of chaperone-mediated autophagy in the pathophysiology including pulmonary disorders

Autophagy is a highly conserved mechanism of delivering cytoplasmic components for lysosomal degradation. Among the three major autophagic pathways, chaperone-mediated autophagy (CMA) is primarily characterized by its selective nature of protein degradation, which is mediated by heat shock cognate 71 kDa protein (HSC70: also known as HSPA8) recognition of the KFERQ peptide motif in target proteins. Lysosome-associated membrane protein type 2A (LAMP2A) is responsible for substrate binding and internalization to lysosomes, and thus, the lysosomal expression level of LAMP2A is a rate-limiting factor for CMA. Recent advances have uncovered not only physiological but also pathological role of CMA in multiple organs, including neurodegenerative disorders, kidney diseases, liver diseases, heart diseases, and cancers through the accumulation of unwanted proteins or increased degradation of target proteins with concomitant metabolic alterations resulting from CMA malfunction. With respect to pulmonary disorders, the involvement of CMA has been demonstrated in lung cancer and chronic obstructive pulmonary disease (COPD) pathogenesis through regulating apoptosis. Further understanding of CMA machinery may shed light on the molecular mechanisms of refractory disorders and lead to novel treatment modalities through CMA modulation.

The ubiquitin ligase RNF5 determines acute myeloid leukemia growth and susceptibility to histone deacetylase inhibitors

Acute myeloid leukemia (AML) remains incurable, largely due to its resistance to conventional treatments. Here, we find that increased abundance of the ubiquitin ligase RNF5 contributes to AML development and survival. High RNF5 expression in AML patient specimens correlates with poor prognosis. RNF5 inhibition decreases AML cell growth in culture, in patient-derived xenograft (PDX) samples and in vivo, and delays development of MLL-AF9-driven leukemogenesis in mice, prolonging their survival. RNF5 inhibition causes transcriptional changes that overlap with those seen upon histone deacetylase (HDAC)1 inhibition. RNF5 induces the formation of K29 ubiquitin chains on the histone-binding protein RBBP4, promoting its recruitment to and subsequent epigenetic regulation of genes involved in AML maintenance. Correspondingly, RNF5 or RBBP4 knockdown enhances AML cell sensitivity to HDAC inhibitors. Notably, low expression of both RNF5 and HDAC coincides with a favorable prognosis. Our studies identify an ERAD-independent role for RNF5, demonstrating that its control of RBBP4 constitutes an epigenetic pathway that drives AML, and highlight RNF5/RBBP4 as markers useful to stratify patients for treatment with HDAC inhibitors.

OS05.8.A A Phase 0/1 ‘Trigger’ Trial of Ribociclib Plus Everolimus in Recurrent High-Grade Glioma

BACKGROUND

The RB-CDK4/6 and mTOR signaling pathways are deregulated in high-grade glioma (HGG) and mTOR activation is a potential mechanism of resistance to CDK4/6 inhibition. This study evaluates the tumor pharmacokinetics (PK) and tumor pharmacodynamics (PD) of combined CDK4/6 and mTOR inhibition in recurrent HGG patients.

MATERIAL AND METHODS

Eligible patients had recurrent HGG with (1) intact RB expression, (2) CDKN2A/B deletion or CDK4/6 amplification, and (3) PTEN loss or PIK3CA mutations. Six patients received five days of presurgical ribociclib (400mg QD) plus everolimus (2.5mg QD) and then underwent tumor resection at 2, 8 or 24 hours following the last dose. Five subsequent dose-escalation cohorts each enrolled three additional patients, reaching a maximum dose-level of ribociclib (600mg QD) plus everolimus (60mg QW). Tumor tissue (gadolinium [Gd]-enhancing and nonenhancing regions), CSF, and plasma were collected. Total and unbound drug concentrations were determined using validated LC-MS/MS methods. Tumor PD effects, including RB and S6 phosphorylation, were compared to matched archival tissue. A PK ‘trigger’ (i.e., unbound concentration &gt; 5-fold biochemical IC50) and a PD ‘trigger’ (&gt;30% decrease in both pRB and pS6) were set for each drug. Gd-nonenhancing tissue exhibiting both PK and PD effects in excess of these thresholds qualified patients for postoperative combination therapy.

RESULTS

21 patients with WHO Grade III (n=2) and WHO Grade IV (n=19) gliomas were enrolled. No dose-limiting toxicities were observed. Following presurgical drug, all patients demonstrated marked decrease in Gd-enhancement on preoperative MRI. In Gd-nonenhancing tumor regions, the median unbound concentration of ribociclib was 719 nM (i.e., &gt; 5-fold biochemical IC50 for CDK4/6 inhibition), whereas the unbound everolimus tumor concentrations in all patients were below the lower limit of quantitation (i.e., &lt; 0.2 nM). The median total concentrations of everolimus in tumors at dose-levels 0 to 5 were 2.9, 8.8, 10.3, 5.0, 15.7, and 13.7 nM, respectively. Across all dose-levels, 62% (13/21) and 22% (5/21) of tumors demonstrated decreased tumor RB and S6 phosphorylation, respectively. Tumor proliferation (MIB-1) was decreased in 67% (14/21) of all patients.

CONCLUSION

In adult HGG, ribociclib achieves pharmacologically-relevant concentrations in Gd-nonenhancing tumor, consistent with the observed tumor PD effects. Everolimus exhibits very limited penetration into human glioma tissue. Our study supports further development of ribociclib, but not everolimus, for the treatment of glioma patients.

Mechanisms of instantaneous inactivation of SARS-CoV-2 by silicon nitride bioceramic

The hydrolytic processes occurring at the surface of silicon nitride (Si3N4) bioceramic have been indicated as a powerful pathway to instantaneous inactivation of SARS-CoV-2 virus. However, the virus inactivation mechanisms promoted by Si3N4 remain yet to be elucidated. In this study, we provide evidence of the instantaneous damage incurred on the SARS-CoV-2 virus upon contact with Si3N4. We also emphasize the safety characteristics of Si3N4 for mammalian cells. Contact between the virions and micrometric Si3N4 particles immediately targeted a variety of viral molecules by inducing post-translational oxidative modifications of S-containing amino acids, nitration of the tyrosine residue in the spike receptor binding domain, and oxidation of RNA purines to form formamidopyrimidine. This structural damage in turn led to a reshuffling of the protein secondary structure. These clear fingerprints of viral structure modifications were linked to inhibition of viral functionality and infectivity. This study validates the notion that Si3N4 bioceramic is a safe and effective antiviral compound; and a primary antiviral candidate to replace the toxic and allergenic compounds presently used in contact with the human body and in long-term environmental sanitation.

Cribriform carcinoma in the lymph nodes is associated with distant metastasis, recurrence, and survival among patients with node-positive colorectal cancer

Cribriform lymph node pattern is an independent risk factor for metachronous or synchronous distant metastasis in patients with stage III and IV node-positive colorectal cancer. Multivariable analysis in patients with stage III disease indicated that the cribriform pattern of carcinoma in the lymph nodes was an independent risk factor for recurrence and survival. Kaplan–Meier analysis demonstrated that the group with stage III cribriform-type lymph node carcinoma had shorter recurrence-free and overall survival times than the stage III group with the tubular type (P &lt; 0.001).

Human bronchial epithelial cell-derived extracellular vesicle therapy for pulmonary fibrosis via inhibition of TGF-β-WNT crosstalk

Idiopathic pulmonary fibrosis (IPF) is characterized by devastating and progressive lung parenchymal fibrosis, resulting in poor patient prognosis. An aberrant recapitulation of developmental lung gene expression, including genes for transforming growth factor (TGF)-β and WNT, has been widely implicated in the pathogenic IPF wound healing process that results from repetitive alveolar epithelial injury. Extracellular vesicles (EVs) have been shown to carry bioactive molecules and to be involved in various physiological and pathological processes. Here, we demonstrate that, by attenuating WNT signalling, human bronchial epithelial cell-derived EVs (HBEC EVs) inhibit TGF-β mediated induction of both myofibroblast differentiation and lung epithelial cellular senescence. This effect of HBEC EVs is more pronounced than that observed with mesenchymal stem cell-derived EVs. Mechanistically, the HBEC EV microRNA (miRNA) cargo is primarily responsible for attenuating both myofibroblast differentiation and cellular senescence. This attenuation occurs via inhibition of canonical and non-canonical WNT signalling pathways. Among enriched miRNA species present in HBEC EVs, miR-16, miR-26a, miR-26b, miR-141, miR-148a, and miR-200a are mechanistically involved in reducing WNT5A and WNT10B expression in LFs, and in reducing WNT3A, WNT5A, and WNT10B expression in HBECs. Mouse models utilizing intratracheal administration of EVs demonstrate efficient attenuation of bleomycin-induced lung fibrosis development accompanied by reduced expression of both β-catenin and markers of cellular senescence. These findings indicate that EVs derived from normal resident lung HBECs may possess anti-fibrotic properties. They further suggest that, via miRNA-mediated inhibition of TGF-β-WNT crosstalk, HBEC EVs administration can be a promising anti-fibrotic modality of treatment for IPF.

An infantile late-onset case Group of B Streptococcus meningitis diagnosed with a rapid latex kit

Globally, vaccination has reduced the prevalence of meningitis caused by Streptococcus pneumoniae Neisseria meningitidis, and Haemophilus influenzae. However, neonatal Group B Streptococcus (GBS) meningitis continues to remain a problematic infection of the central nervous system. Here, we report a case of bacterial meningitis in a 34-day old male baby who presented with fever. A cerebrospinal fluid (CSF) test on the day of admission showed an increase in cell count with decreased glucose level. A rapid latex test of the CSF using a commercial kit diagnosed the causative pathogen as GBS. We administered the antibiotics ampicillin, cefotaxime, gentamicin and panipenem/betamipron to the patient for over 14 days. Partial seizures were frequently observed during the course and were well-controlled with midazolam and phenobarbital. Brain magnetic resonance imaging on day 17 showed subdural hygroma in the frontal region, and 99mTc ethyl-cysteinate dimer-single photon emission computed tomography confirmed a decreased cerebral blood flow predominantly in the left frontal region. After three years of follow-up, the condition of the patient improved without any neurological sequelae. Our report highlights that rapid identification of the causative organism is essential in infantile late-onset meningitis. In addition, we consider that the latex kit-based rapid testing of CSF is beneficial for identifying the causative agent of bacterial meningitis.

Impaired TRIM16-Mediated Lysophagy in Chronic Obstructive Pulmonary Disease Pathogenesis

Insufficient autophagic degradation has been implicated in accelerated cellular senescence during chronic obstructive pulmonary disease (COPD) pathogenesis. Aging-linked and cigarette smoke (CS)-induced functional deterioration of lysosomes may be associated with impaired autophagy. Lysosomal membrane permeabilization (LMP) is indicative of damaged lysosomes. Galectin-3 and tripartite motif protein (TRIM) 16 play a cooperative role in recognizing LMP and inducing lysophagy, a lysosome-selective autophagy, to maintain lysosome function. In this study, we sought to examine the role of TRIM16-mediated lysophagy in regulating CS-induced LMP and cellular senescence during COPD pathogenesis by using human bronchial epithelial cells and lung tissues. CS extract (CSE) induced lysosomal damage via LMP, as detected by galectin-3 accumulation. Autophagy was responsible for modulating LMP and lysosome function during CSE exposure. TRIM16 was involved in CSE-induced lysophagy, with impaired lysophagy associated with lysosomal dysfunction and accelerated cellular senescence. Airway epithelial cells in COPD lungs showed an increase in lipofuscin, aggresome and galectin-3 puncta, reflecting accumulation of lysosomal damage with concomitantly reduced TRIM16 expression levels. Human bronchial epithelial cells isolated from COPD patients showed reduced TRIM16 but increased galectin-3, and a negative correlation between TRIM16 and galectin-3 protein levels was demonstrated. Damaged lysosomes with LMP are accumulated in epithelial cells in COPD lungs, which can be at least partly attributed to impaired TRIM16-mediated lysophagy. Increased LMP in lung epithelial cells may be responsible for COPD pathogenesis through the enhancement of cellular senescence.

Effectiveness of Switching Biologics for Severe Asthma Patients in Japan: A Single-Center Retrospective Study

BACKGROUND

In Japan, biologic therapy was initiated for patients with severe asthma in 2009. In recent years, four biologics with different mechanisms of action have become available in the clinical setting. However, the efficacy of switching between biologics remains uncertain.

METHODS

To elucidate the efficacy of switching between biologics, 97 patients were enrolled who had received any biologic therapy for severe asthma at Jikei University Hospital, Tokyo, Japan, from July 2009 to December 2020. We retrospectively examined the patient characteristics, biomarkers, pulmonary function test results, selected biologics, and efficacy.

RESULTS

Thirty-one males and 66 females received any biologics. The mean age was 53.3 years at the initiation of biologic therapy. Initially, 33, 41, 15 and eight patients received omalizumab, mepolizumab, benralizumab, and dupilumab, respectively. Among three representative indicators for biologics administration, the peripheral blood eosinophil count, serum IgE levels and fractional exhaled nitric oxide, 64% of the patients had two indicators, and 28% had three indicators. Thirty-four patients (35%) switched from the initial biologic to another, and the reasons for switching included persistent asthmatic symptoms (n=22), schedule of hospital visits (n=5), and other reasons. Thus, the treatment was effective in 11 patients after switching. In addition, two patients received combination therapy with different biologics. Eighteen patients (19%) interrupted treatment for various reasons. Regardless of whether the biologic was the initial therapy, the overall efficacy of the four biologics was 60% based on the global evaluation of treatment effectiveness.

CONCLUSION

Switching between biologics can be a promising option for severe asthma patients in whom treatment with an initial biologic is ineffective.

Early prediction of COVID-19 severity using extracellular vesicle COPB2

The clinical manifestations of COVID-19 vary broadly, ranging from asymptomatic infection to acute respiratory failure and death. But the predictive biomarkers for characterizing the variability are still lacking. Since emerging evidence indicates that extracellular vesicles (EVs) and extracellular RNAs (exRNAs) are functionally involved in a number of pathological processes, we hypothesize that these extracellular components may be key determinants and/or predictors of COVID-19 severity. To test our hypothesis, we collected serum samples from 31 patients with mild COVID-19 symptoms at the time of their admission for discovery cohort. After symptomatic treatment without corticosteroids, 9 of the 31 patients developed severe/critical COVID-19 symptoms. We analyzed EV protein and exRNA profiles to look for correlations between these profiles and COVID-19 severity. Strikingly, we identified three distinct groups of markers (antiviral response-related EV proteins, coagulation-related markers, and liver damage-related exRNAs) with the potential to serve as early predictive biomarkers for COVID-19 severity. As the best predictive marker, EV COPB2 protein, a subunit of the Golgi coatomer complex, exhibited significantly higher abundance in patients remained mild than developed severe/critical COVID-19 and healthy controls in discovery cohort (AUC 1.00 (95% CI: 1.00-1.00)). The validation set included 40 COVID-19 patients and 39 healthy controls, and showed exactly the same trend between the three groups with excellent predictive value (AUC 0.85 (95% CI: 0.73-0.97)). These findings highlight the potential of EV COPB2 expression for patient stratification and for making early clinical decisions about strategies for COVID-19 therapy.

Dietary cis-9, trans-11-conjugated linoleic acid reduces amyloid β-protein accumulation and upregulates anti-inflammatory cytokines in an Alzheimer's disease mouse model

Conjugated linoleic acid (CLA) is an isomer of linoleic acid (LA). The predominant dietary CLA is cis-9, trans-11-CLA (c-9, t-11-CLA), which constitutes up to ~ 90% of total CLA and is thought to be responsible for the positive health benefits associated with CLA. However, the effects of c-9, t-11-CLA on Alzheimer's disease (AD) remain to be elucidated. In this study, we investigated the effect of dietary intake of c-9, t-11-CLA on the pathogenesis of an AD mouse model. We found that c-9, t-11-CLA diet-fed AD model mice significantly exhibited (1) a decrease in amyloid-β protein (Aβ) levels in the hippocampus, (2) an increase in the number of microglia, and (3) an increase in the number of astrocytes expressing the anti-inflammatory cytokines, interleukin-10 and 19 (IL-10, IL-19), with no change in the total number of astrocytes. In addition, liquid chromatography-tandem mass spectrometry (LC-MS/MS) and gas chromatographic analysis revealed that the levels of lysophosphatidylcholine (LPC) containing c-9, t-11-CLA (CLA-LPC) and free c-9, t-11-CLA were significantly increased in the brain of c-9, t-11-CLA diet-fed mice. Thus, dietary c-9, t-11-CLA entered the brain and appeared to exhibit beneficial effects on AD, including a decrease in Aβ levels and suppression of inflammation.

Prebiotic-Induced Anti-tumor Immunity Attenuates Tumor Growth

Growing evidence supports the importance of gut microbiota in the control of tumor growth and response to therapy. Here, we select prebiotics that can enrich bacterial taxa that promote anti-tumor immunity. Addition of the prebiotics inulin or mucin to the diet of C57BL/6 mice induces anti-tumor immune responses and inhibition of BRAF mutant melanoma growth in a subcutaneously implanted syngeneic mouse model. Mucin fails to inhibit tumor growth in germ-free mice, indicating that the gut microbiota is required for the activation of the anti-tumor immune response. Inulin and mucin drive distinct changes in the microbiota, as inulin, but not mucin, limits tumor growth in syngeneic mouse models of colon cancer and NRAS mutant melanoma and enhances the efficacy of a MEK inhibitor against melanoma while delaying the emergence of drug resistance. We highlight the importance of gut microbiota in anti-tumor immunity and the potential therapeutic role for prebiotics in this process.

Intercellular Communication by Vascular Endothelial Cell-Derived Extracellular Vesicles and Their MicroRNAs in Respiratory Diseases

Respiratory diseases and their comorbidities, such as cardiovascular disease and muscle atrophy, have been increasing in the world. Extracellular vesicles (EVs), which include exosomes and microvesicles, are released from almost all cell types and play crucial roles in intercellular communication, both in the regulation of homeostasis and the pathogenesis of various diseases. Exosomes are of endosomal origin and range in size from 50 to 150 nm in diameter, while microvesicles are generated by the direct outward budding of the plasma membrane in size ranges of 100-2,000 nm in diameter. EVs can contain various proteins, metabolites, and nucleic acids, such as mRNA, non-coding RNA species, and DNA fragments. In addition, these nucleic acids in EVs can be functional in recipient cells through EV cargo. The endothelium is a distributed organ of considerable biological importance, and disrupted endothelial function is involved in the pathogenesis of respiratory diseases such as chronic obstructive pulmonary disease, pulmonary hypertension, and acute respiratory distress syndrome. Endothelial cell-derived EVs (EC-EVs) play crucial roles in both physiological and pathological conditions by traveling to distant sites through systemic circulation. This review summarizes the pathological roles of vascular microRNAs contained in EC-EVs in respiratory diseases, mainly focusing on chronic obstructive pulmonary disease, pulmonary hypertension, and acute respiratory distress syndrome. Furthermore, this review discusses the potential clinical usefulness of EC-EVs as therapeutic agents in respiratory diseases.

Extracellular Vesicles from Fibroblasts Induce Epithelial-Cell Senescence in Pulmonary Fibrosis

Aberrant epithelial-mesenchymal interactions have critical roles in regulating fibrosis development. The involvement of extracellular vesicles (EVs), including exosomes, remains to be elucidated in the pathogenesis of idiopathic pulmonary fibrosis (IPF). Here, we found that lung fibroblasts (LFs) from patients with IPF induce cellular senescence via EV-mediated transfer of pathogenic cargo to lung epithelial cells. Mechanistically, IPF LF-derived EVs increased mitochondrial reactive oxygen species and associated mitochondrial damage in lung epithelial cells, leading to activation of the DNA damage response and subsequent epithelial-cell senescence. We showed that IPF LF-derived EVs contain elevated levels of microRNA-23b-3p (miR-23b-3p) and miR-494-3p, which suppress SIRT3, resulting in the epithelial EV-induced phenotypic changes. Furthermore, the levels of miR-23b-3p and miR-494-3p found in IPF LF-derived EVs correlated positively with IPF disease severity. These findings reveal that the accelerated epithelial-cell mitochondrial damage and senescence observed during IPF pathogenesis are caused by a novel paracrine effect of IPF fibroblasts via microRNA-containing EVs.

Insulinoma induces a hyperinsulinemia-mediated decrease of GLUT2 and GLP1 receptor in normal pancreatic β-cells

There have been several clinical reports of transient postoperative hyperglycemia in patients with insulinoma, but the effect of insulinoma on normal β-cells has not been investigated. We examined the glucose transporter 2 (GLUT2) and glucagon-like peptide 1 receptor (GLP1R) expression in normal pancreatic β-cells of five patients with insulinoma and five patients with normal glucose tolerance (NGT) as controls. The positive rate of GLUT2-or GLP1R-positive islets in the nontumor area was calculated by the ratio with the analyzed islets. For functional in vitro analyses, q-PCR and Western blotting were performed after insulin loading on MIN6 cells. The expression rates of both GLUT2 and GLP1R were significantly lower in nontumor area islets of insulinoma patients than in patients with NGT (GLUT2: 31.6 ± 15.3% vs 95.9 ± 6.7%, p < 0.01, GLP1R: 66.8 ± 15.0% vs 96.7 ± 5.0%, p < 0.01). Exposure of MIN6 cells to high concentrations of insulin resulted in a significant decrease in GLUT2 protein for 12 h and GLP1R protein for 24 h (GLUT2; 1.00 ± 0.079 vs 0.81 ± 0.04. p = 0.02, GLP1R; 1.00 ± 0.10 vs 0.50 ± 0.24, p = 0.03) but not in those mRNAs. Our findings show that insulinoma is associated with the downregulation of GLUT2 and GLP1R expression in nontumor area islets. These phenomena may be caused by high levels of insulin.

Prediction of the improvement of left ventricular wall motion after acute myocardial infarction by simultaneous dual-isotope imaging with 99mTc-sestamibi/123I-BMIPP using cadmium-zinc-telluride SPECT

Background/Introduction

Although both the presence of 99mTc-sestamibi/123I-BMIPP mismatch and the reverse redistribution of 99mTc-sestamibi in patients with acute myocardial infarction (AMI) are known to significant markers for predicting the improvement of left ventricular (LV) wall motion in the infarcted territory in chronic phase, few studies evaluated them by simultaneous dual-isotope (99mTc-sestamibi/123I-BMIPP) imaging using cadmium-zinc-telluride (CZT) SPECT system.

Purpose

The purpose of this study was to evaluate whether the presence of 99mTc-sestamibi/123I-BMIPP mismatch or the reverse redistribution of 99mTc-sestamibi make better prediction of the improvement of LV wall motion in the infarcted territory.

Methods

We evaluated 30 consecutive patients with AMI who had undergone both dual-isotope (99mTc-sestamibi/123I-BMIPP) SPECT in acute phase and stress myocardial SPECT using 99mTc-tracers in chronic phase by Discovery NM530c. Both 99mTc-sestamibi/123I-BMIPP mismatch and reverse redistribution of 99mTc-sestamibi were determined using traditional definition. The improvement of LV wall motion in the infarcted territory from acute phase to chronic phase was assessed using QGS.

Results

Of 30 patients, the improvement of LV wall motion in the infarcted territory from acute phase to chronic phase was found in 20 patients. Both the presence of 99mTc-sestamibi/123I-BMIPP mismatch and reverse redistribution of 99mTc-sestamibi were significantly linked to predict the improvement of LV wall motion (p=0.0001, p=0.011, respectively). The respective sensitivities, specificities and accuracies in the prediction of the improvement of LV wall motion in the infarcted territory were 90%, 90% and 90% with 99mTc-sestamibi/123I-BMIPP mismatch, and 60%, 90%, 70% with reverse redistribution of 99mTc-sestamibi.

Conclusions

In the simultaneous 99mTc-sestamibi/123I-BMIPP dual-isotope imaging using CZT SPECT system, both the presence of 99mTc-sestamibi/123I-BMIPP mismatch and the reverse redistribution of 99mTc-sestamibi in acute phase are useful for predicting the improvement of LV wall motion in chronic phase, but the presence of 99mTc-sestamibi/123I-BMIPP mismatch is superior to the reverse redistribution of 99mTc-sestamibi for it.

Funding Acknowledgement

Type of funding source: None