TMEM106B coding variant is protective and deletion detrimental in a mouse model of tauopathy

TMEM106B is a risk modifier of multiple neurological conditions, where a single coding variant and multiple non-coding SNPs influence the balance between susceptibility and resilience. Two key questions that emerge from past work are whether the lone T185S coding variant contributes to protection, and if the presence of TMEM106B is helpful or harmful in the context of disease. Here, we address both questions while expanding the scope of TMEM106B study from TDP-43 to models of tauopathy. We generated knockout mice with constitutive deletion of TMEM106B, alongside knock-in mice encoding the T186S knock-in mutation (equivalent to the human T185S variant), and crossed both with a P301S transgenic tau model to study how these manipulations impacted disease phenotypes. We found that TMEM106B deletion accelerated cognitive decline, hind limb paralysis, tau pathology, and neurodegeneration. TMEM106B deletion also increased transcriptional correlation with human AD and the functional pathways enriched in KO:tau mice aligned with those of AD. In contrast, the coding variant protected against tau-associated cognitive decline, synaptic impairment, neurodegeneration, and paralysis without affecting tau pathology. Our findings reveal that TMEM106B is a critical safeguard against tau aggregation, and that loss of this protein has a profound effect on sequelae of tauopathy. Our study further demonstrates that the coding variant is functionally relevant and contributes to neuroprotection downstream of tau pathology to preserve cognitive function.

Generation of a Dcx-CreERT2 knock-in mouse for genetic manipulation of newborn neurons

A wide variety of CreERT2 driver lines are available for genetic manipulation of adult-born neurons in the mouse brain. These tools have been instrumental in studying fate potential, migration, circuit integration, and morphology of the stem cells supporting lifelong neurogenesis. Despite a wealth of tools, genetic manipulation of adult-born neurons for circuit and behavioral studies has been limited by poor specificity of many driver lines targeting early progenitor cells and by the inaccessibility of lines selective for later stages of neuronal maturation. We sought to address these limitations by creating a new CreERT2 driver line targeted to the endogenous mouse doublecortin locus as a marker of fate-specified neuroblasts and immature neurons. Our new model places a T2A-CreERT2 cassette immediately downstream of the Dcx coding sequence on the X chromosome, allowing expression of both Dcx and CreERT2 proteins in the endogenous spatiotemporal pattern for this gene. We demonstrate that the new mouse line drives expression of a Cre-dependent reporter throughout the brain in neonatal mice and in known neurogenic niches of adult animals. The line has been deposited with the Jackson Laboratory and should provide an accessible tool for studies targeting fate-restricted neuronal precursors.

TMEM106B coding variant is protective and deletion detrimental in a mouse model of tauopathy

TMEM106B is a risk modifier for a growing list of age-associated dementias including Alzheimer’s and frontotemporal dementia, yet its function remains elusive. Two key questions that emerge from past work are whether the conservative T185S coding variant found in the minor haplotype contributes to protection, and whether the presence of TMEM106B is helpful or harmful in the context of disease. Here we address both issues while extending the testbed for study of TMEM106B from models of TDP to tauopathy. We show that TMEM106B deletion accelerates cognitive decline, hindlimb paralysis, neuropathology, and neurodegeneration. TMEM106B deletion also increases transcriptional overlap with human AD, making it a better model of disease than tau alone. In contrast, the coding variant protects against tau-associated cognitive decline, neurodegeneration, and paralysis without affecting tau pathology. Our findings show that the coding variant contributes to neuroprotection and suggest that TMEM106B is a critical safeguard against tau aggregation.

Extensive accumulation of misfolded protein aggregates during natural aging and senescence

Accumulation of misfolded protein aggregates is a hallmark event in many age-related protein misfolding disorders, including some of the most prevalent and insidious neurodegenerative diseases. Misfolded protein aggregates produce progressive cell damage, organ dysfunction, and clinical changes, which are common also in natural aging. Thus, we hypothesized that aging is associated to the widespread and progressive misfolding and aggregation of many proteins in various tissues. In this study, we analyzed whether proteins misfold, aggregate, and accumulate during normal aging in three different biological systems, namely senescent cells, Caenorhabditis elegans, and mouse tissues collected at different times from youth to old age. Our results show a significant accumulation of misfolded protein aggregates in aged samples as compared to young materials. Indeed, aged samples have between 1.3 and 2.5-fold (depending on the biological system) higher amount of insoluble proteins than young samples. These insoluble proteins exhibit the typical characteristics of disease-associated aggregates, including insolubility in detergents, protease resistance, and staining with amyloid-binding dye as well as accumulation in aggresomes. We identified the main proteins accumulating in the aging brain using proteomic studies. These results show that the aged brain contain large amounts of misfolded and likely non-functional species of many proteins, whose soluble versions participate in cellular pathways that play fundamental roles in preserving basic functions, such as protein quality control, synapsis, and metabolism. Our findings reveal a putative role for protein misfolding and aggregation in aging.

Prasugrel-based de-escalation vs. conventional therapy after percutaneous coronary intervention in ACS patients according to the renal function

Funding Acknowledgements

Type of funding sources: Private company. Main funding source(s): A consortium of six companies in Korea (Daiichi Sankyo, Boston Scientific, Terumo, Biotronik, Qualitech Korea, and Dio).

Background

Patients with coronary artery disease and impaired renal function are at higher risk for both bleeding and ischemic adverse events after percutaneous coronary intervention (PCI).

Purpose

We assessed the efficacy and safety of a prasugrel based de-escalation strategy in patients with impaired renal function.

Methods

We conducted a post-hoc analysis of the HOST-REDUCE-POLYTECH-ACS study. Patients with available estimated glomerular filtration rate (eGFR) (n=2,311) were categorized into three groups. (high eGFR: ≥90 mL/min; intermediate eGFR: ≥60 and <90 mL/min; low eGFR: <60 mL/min). The endpoints were bleeding outcomes (Bleeding Academic Research Consortium type 2, or higher), ischemic outcomes (cardiovascular death, myocardial infarction, stent thrombosis, repeat revascularization, and ischemic stroke), and net adverse clinical events (all cause death, BARC 2 or greater bleeding, MI, stent thrombosis, repeat revascularization, and ischemic stroke) at 1 year follow-up. The hazard ratio (HR) and 95% Confidence interval (CI) were calculated from the multivariate Cox proportional hazard regression analysis. Covariates that were considered clinically meaningful were included. The probability risk ratio was obtained by dividing ischemic hazard function from the bleeding hazard function.

Results

With respect to net adverse clinical events, prasugrel de-escalation was beneficial regardless of baseline renal function (p for interaction = 0.508). The relative reduction in bleeding risk from prasugrel de-escalation was higher in the low eGFR group compared with that from both the intermediate and high eGFR groups (relative reduction: 64% [HR 0.36, 95% CI 0.15–0.83] vs. 50% [HR 0.50, 95% CI 0.28-0.90] and 52% [HR 0.48, 95% CI 0.21-1.13] for low, intermediate, and high eGFR groups, p for interaction=0.646). Ischemic risk from prasgurel de-escalation was not significant in all eGFR groups ([HR 1.18, 95% CI 0.47-2.98], [HR 0.95, 95% CI 0.53-1.69], and [HR 0.61, 95% CI 0.26-1.39)], respectively, p for interaction=0.119). The probability risk ratio was highest in low eGFR group (1.06 vs. 1.26 vs. 1.36, for high, intermediate, and low eGFR groups, respectively, p for trend<0.001), suggesting higher relative bleeding risk above ischemic risk. Within those randomized to the de-escalation strategy, the mean probability risk ratio was not significantly different according to renal function (0.89, vs. 0.84 vs. 0.80 respectively, p for trend = 0.053), which was in contrast to those randomized to the conventional strategy where the mean probability risk ratio increased significantly as renal function decreased (1.24 vs. 1.67 vs. 1.94 respectively, p for trend<0.001).

Conclusion

The beneficial effect of prasugrel-based de-escalation strategy was consistent regardless of the baseline renal function, which was mostly driven by a reduction in bleeding risk which was greatest in those with low eGFR.

Activity disruption causes degeneration of entorhinal neurons in a mouse model of Alzheimer's circuit dysfunction

Neurodegenerative diseases are characterized by selective vulnerability of distinct cell populations; however, the cause for this specificity remains elusive. Here, we show that entorhinal cortex layer 2 (EC2) neurons are unusually vulnerable to prolonged neuronal inactivity compared with neighboring regions of the temporal lobe, and that reelin + stellate cells connecting EC with the hippocampus are preferentially susceptible within the EC2 population. We demonstrate that neuronal death after silencing can be elicited through multiple independent means of activity inhibition, and that preventing synaptic release, either alone or in combination with electrical shunting, is sufficient to elicit silencing-induced degeneration. Finally, we discovered that degeneration following synaptic silencing is governed by competition between active and inactive cells, which is a circuit refinement process traditionally thought to end early in postnatal life. Our data suggests that the developmental window for wholesale circuit plasticity may extend into adulthood for specific brain regions. We speculate that this sustained potential for remodeling by entorhinal neurons may support lifelong memory but renders them vulnerable to prolonged activity changes in disease.

Temporal and spatially controlled APP transgene expression using Cre-dependent alleles

Although a large number of mouse models have been made to study Alzheimer's disease, only a handful allow experimental control over the location or timing of the protein being used to drive pathology. Other fields have used the Cre and the tamoxifen-inducible CreER driver lines to achieve precise spatial and temporal control over gene deletion and transgene expression, yet these tools have not been widely used in studies of neurodegeneration. Here, we describe two strategies for harnessing the wide range of Cre and CreER driver lines to control expression of disease-associated amyloid precursor protein (APP) in modeling Alzheimer's amyloid pathology. We show that CreER-based spatial and temporal control over APP expression can be achieved with existing lines by combining a Cre driver with a tetracycline-transactivator (tTA)-dependent APP responder using a Cre-to-tTA converter line. We then describe a new mouse line that places APP expression under direct control of Cre recombinase using an intervening lox-stop-lox cassette. Mating this allele with a CreER driver allows both spatial and temporal control over APP expression, and with it, amyloid onset. This article has an associated First Person interview with the first author of the paper.

Aspirin vs. Clopidogrel as a Chronic maintenance monotherapy after PCI in patients with high ischemic risk and high bleeding risk: Subgroup analysis of the HOST-EXAM trial

Funding Acknowledgements

Type of funding sources: None.

OnBehalf

on behalf of the HOST-EXAM investigators

Background

The HOST-EXAM randomized clinical trial recently performed a comparison of clopidogrel monotherapy vs. aspirin monotherapy in patients requiring indefinite antiplatelet monotherapy after percutaneous coronary intervention (PCI). This study randomized 5,438 patients who maintained dual antiplatelet therapy without clinical events for 6–18 months after PCI with drug-eluting stents (DES) to receive a monotherapy agent of clopidogrel 75 mg once daily or aspirin 100 mg once daily for 24 months. During the 24-month follow-up, the primary outcome (a composite of all-cause death, non-fatal myocardial infarction, stroke, readmission due to acute coronary syndrome, and Bleeding Academic Research Consortium (BARC) bleeding type 3 or greater) rate was significantly lower in the clopidogrel group (hazard ratio [HR] 0.73 [95% CI 0.59–0.90]; p = 0.0035). However, it is uncertain whether the beneficial effect of clopidogrel will be consistent in patients with high ischemic risk or those with high bleeding risk.

Methods

This is a post-hoc analysis of the HOST-EXAM trial. A high ischemic risk was defined as those who had at least 1 of the following procedural features: 3 vessels treated, ≥3 stents implanted, ≥3 lesions treated, bifurcation PCI, total stent length >60 mm, or left main PCI. Patients with high bleeding risk were defined according to the Academic Research Consortium for High Bleeding Risk (ARC-HBR) criteria. The co-primary outcome were thrombotic endpoints (a composite of cardiac death, non-fatal myocardial infarction, ischemic stroke, readmission due to acute coronary syndrome, and definite or probable stent thrombosis) and bleeding endpoints (BARC type ≥2 bleeding events) at 24-month follow-up.

Results

 Among the total population, 22.1% had high ischemic risk and 21.4% had high bleeding risk. Complex PCI was not associated with a higher risk of thrombotic endpoints, nor bleeding endpoints. For patients with a high bleeding risk, these patients had a higher risk of both thrombotic endpoints (HR 1.545, 95% CI 0.141-2.092, p = 0.005) and bleeding endpoints (HR 3.418, 95% CI 2.413-4.840, p < 0.001). The primary results focusing on the interaction between high ischemic risk, high bleeding and the antiplatelet regimen will be presented.

Conclusion

The current post-hoc analysis of the HOST-EXAM trial will evaluate the efficacy of clopidogrel monotherapy vs. aspirin monotherapy during the chronic maintenance period after PCI, in patients with high ischemic risk or those with high bleeding risk.

Computed tomographic features of the temporomandibular joint in 10 Jeju horses

Background

Objectives

Methods

Results

Conclusions

Dual antithrombotic therapy on early clinical outcomes in patients with atrial fibrillation after percutaneous coronary intervention: a nationwide study in the era of NOAC

Background/Introduction

Recent evidence has confirmed low bleeding risk with double antithrombotic therapy, combining oral anticoagulant (OAC) and single platelet inhibitor, in patients with atrial fibrillation (AF) undergoing percutaneous coronary intervention (PCI). Among the Asian AF population, most of the patients received dual antiplatelet therapy (DAPT) without OACs, even after the introduction of non-vitamin K oral anticoagulants (NOACs).

Purpose

The current nationwide study assessed 3-month ischemic and bleeding risks of DAPT in comparison to triple antithrombotic therapy among the Korean AF population undergoing PCI.

Methods

We analyzed the claims records of 11,039 patients (mean age 70 years, 66.3% male, and mean CHA2DS2-VASc score 3.2) between 2013 to 2018. Patients were categorized into triple therapy group with vitamin K antagonists (VKAs-TT), or NOACs (NOACs-TT), and DAPT group according to the antithrombotic therapy after PCI. 3-month risks of ischemic stroke, non-fatal myocardial infarction, any in-hospital death, and major bleeding were compared between groups after baseline adjustment using inverse probability weighting.

Results

A total of 1,786, 1,997, and 7,256 patients were allocated to the VKAs-TT, NOACs-TT, and DAPT groups. The DAPT group had a higher prevalence of prior MI and coronary revascularization, but had lower thromboembolic and bleeding risks than the triple antithrombotic therapy groups (mean CHA2DS2-VASc score 3.8, 4.1, and 3.5; and mean HAS-BLED score 3.3, 3.4, and 3.1 for VKAs-TT, NOACs-TT, and DAPT groups, respectively). The NOACs-TT group was associated with a lower risk of ischemic stroke (hazard ratio [HR] 0.38, 95% confidence interval [CI] 0.20–0.70) and any in-hospital death (HR 0.70, 95% CI 0.49–0.98) compared with the VKAs-TT group. The DAPT group showed a lower risk of ischemic stroke (HR 0.41, 95% CI 0.27–0.63) and major bleeding (HR 0.55, 95% CI 0.37–0.84) than the VKAs-TT group, especially in patients without prior OAC treatment. The DAPT group showed a comparable ischemic risk against the NOACs-TT group, although the risk of major bleeding was lower in the DAPT group, especially among old age (HR 0.47, 95% CI 0.29–0.78) or OACs-naive patients (HR 0.50, 95% CI 0.29–0.86).

Conclusion

Among the Asian AF population, using short-term DAPT for 3-month after PCI was associated with a lower risk of bleeding without increasing ischemic risk compared to triple antithrombotic therapy with OAC. This may be a therapeutic option in very high bleeding risk patients who have had complex PCI necessitating focus on DAPT in the initial 3 month period.

Funding Acknowledgement

Type of funding sources: Public Institution(s). Main funding source(s): This study was supported by grant no 3020200200 from the Seoul National University Hospital Research Fund, by the Korea Medical Device Development Fund grant funded by the Korea government (the Ministry of Science and ICT, the Ministry of Trade, Industry and Energy, the Ministry of Health & Welfare, Republic of Korea, the Ministry of Food and Drug Safety) (Project Number: 202013B14), and by the Korea National Research Foundation funded by the Ministry of Education, Science and Technology (grant 2020R1F1A106740). Figure 1Figure 2

A novel index reflecting both anatomical and physiologic parameters in coronary artery disease, the FFR adjusted SYNTAX score (FaSs)

Background

Various physiology-based indices have been proposed to predict adverse clinical events in patients with coronary artery disease (CAD), such as the sum of three vessel-fractional flow reserve (3v-FFR), and the functional SYNTAX score (fSS). However, these values could not fully reflect the anatomical factors, which remains as a barrier for clinical application of these indices.

Purpose

To propose a novel index which can reflect both anatomical and physiologic features in CAD patients, and evaluate the additional predictive value for cardiovascular adverse events compared to previous indices.

Methods

For an index which can reflect both anatomical and physiologic features, we proposed the FFR adjusted SYNTAX score (FaSs). The FaSs is calculated by adding the product of the SYNTAX score and `1-FFR', for all three major coronary arteries. Among the 1136 patients who enrolled at 3V FFR-FRIENDS study, we investigated 866 patients, after excluding those who had missing variables. The 3v-FFR, fSS and FaSs were calculated, derived from the baseline FFR and SYNTAX score. Patients were divided into two groups according to the median value of each index. The primary endpoint was major adverse cardiac events (MACE, a composite of cardiac death, myocardial infarction and ischemia-driven revascularization) at 2 years follow-up.

Results

Among the total population, MACE occurred in 35 (4.04%) patients. Using the median value in a multivariable COX regression model, only FaSs was associated with an increased risk of MACE, (Hazard Ratio [HR] 5.256, 95% confidence interval [CI] 2.014–13.720), while 3v-FFR (HR 1.383, 95% CI 0.685–2.790) and fSS (HR 1.640, 95% CI 0.830–3.243) were not significantly associated with a higher risk of MACE. This was also observed in the Kaplan Meier survival curve analysis (log-rank p value: p<0.001 for FaSs, 0.153 for 3v-FFR, and 0.061 for fSS; Figure 1) The sensitivity and specificity of the FaSs was 85.7% and 51.6%, which was higher compared to the 3v-FFR (62.9% and 49.3%, respectively) and fSS (57.1% and 58.5%, respectively). When these indices were combined with clinical risk factors (age, sex, hypertension, diabetes, hyperlipidemia, chronic renal failure, LVEF<40%), FaSs was superior compared with 3v-FFR and fSS assessed in regards of the predictive accuracy for MACE (Figure 2).

Conclusion

The FaSs, which is a novel index calculated by a formula using the SYNTAX score and FFR, showed a superior predictive value for MACE compared to previous indices. Our results confirm the importance of considering both anatomical and physiologic parameters in evaluating the patient's risk for cardiovascular adverse outcomes.

Funding Acknowledgement

Type of funding sources: None.

Multi-Component Intervention Program on Habitual Physical Activity Parameters and Cognitive Function in Patients with Mild Cognitive Impairment: A Randomized Controlled Trial

Age-related dementia refers to a state in which someone experiences multiple cognitive function impairment due to degenerative brain disease, and which causes difficulties in their daily life or social life. Dementia is the most common and serious obstacle in later life. Early intervention in the case of patients who are in the mild cognitive impairment (MCI) stage among the high-risk group can maintain and improve their cognitive function. The purpose of the current trial is aimed at investigating the association between a multi-component (exercise with cognitive) intervention program and habitual physical activity parameters on cognitive functions in MCI patients. Neuropsychological cognitive and depression assessments were performed by neuropsychologists according to normalized methods, including the Korean mini-mental State examination (K-MMSE) and modified Alzheimer's disease assessment scale-cognitive subscale (ADAS-Cog) and cognitive assessment tool (attention, processing speed), and the Korean version of the geriatric depression scale (SGDS-K), both at baseline and at a 12 weeks follow-up. The 12-week multi-component intervention improved cognitive function and habitual physical activity parameters in patients with MCI relative to controls. A multi-component intervention program for patients with MCI is considered to be an effective method of dementia prevention by improving global (ADAS-Cog) and frontal (trail-making test, digit symbol substitution test) cognition and habitual physical activity parameters such as moderate to vigorous physical activity and step count. In addition, it is important to encourage habitual physical activities to ensure that exercise intervention strategies are carried out at the duration and intensity required for improving physical and cognitive wellbeing and obtaining health benefits.

Gene therapy using Aβ variants for amyloid reduction

Numerous aggregation inhibitors have been developed with the goal of blocking or reversing toxic amyloid formation in vivo. Previous studies have used short peptide inhibitors targeting different amyloid β (Aβ) amyloidogenic regions to prevent aggregation. Despite the specificity that can be achieved by peptide inhibitors, translation of these strategies has been thwarted by two key obstacles: rapid proteolytic degradation in the bloodstream and poor transfer across the blood-brain barrier. To circumvent these problems, we have created a minigene to express full-length Aβ variants in the mouse brain. We identify two variants, F20P and F19D/L34P, that display four key properties required for therapeutic use: neither peptide aggregates on its own, both inhibit aggregation of wild-type Aβ in vitro, promote disassembly of pre-formed fibrils, and diminish toxicity of Aβ oligomers. We used intraventricular injection of adeno-associated virus (AAV) to express each variant in APP/PS1 transgenic mice. Lifelong expression of F20P, but not F19D/L34P, diminished Aβ levels, plaque burden, and plaque-associated neuroinflammation. Our findings suggest that AAV delivery of Aβ variants may offer a novel therapeutic strategy for Alzheimer's disease. More broadly our work offers a framework for identifying and delivering peptide inhibitors tailored to other protein-misfolding diseases.

Enhanced electrochemical performance of MoS2/graphene nanosheet nanocomposites

Molybdenum disulfide (MoS₂) is attractive as an anode material for next-generation batteries, because of its layered structure being favorable for the insertion/deinsertion of Li⁺ ions, and its fairly high theoretical capacity. However, since the MoS₂ anode material has exhibited disadvantages, such as low electrical conductivity and poor cycling stability, to improve the electrochemical performance of MoS₂ in this study, a nanocomposite structure consisting of MoS₂ and GNS (MoS₂/GNS) as an anode for LIBs was prepared, by controlling the weight ratios of MoS₂/GNS. The X-ray diffraction patterns and electron microscopic analysis showed that the nanocomposite electrode structure consisted of well-formed MoS₂ nanoparticles and GNS. Compared to MoS₂-only, the MoS₂/GNS composites exhibited high retention and improved capacity at high current densities. In particular, among these nanocomposite samples, MoS₂/GNS(8 : 2) with an appropriate portion of GNS exhibited the best LIB performance, due to the lowest interfacial resistance and highest Li-ion diffusivity.

MoS₂/GNS 8 : 2 with an appropriate portion of GNS exhibited the best LIB performance, due to the lowest interfacial resistance and highest Li-ion diffusivity.

Emission characteristics of particulate matter, odors, and volatile organic compounds from the grilling of pork

Meat-grilling restaurants are considered to be residential emission sources of air pollutants. To investigate the emission characteristics of particulate matter (PM), odors, and volatile organic compounds (VOCs) from the grilling of meat, a grilling apparatus equipped with butane gas burners was used to grill pork belly and marinated pork ribs in a laboratory setting. When grilling the pork belly, the emission factor for PM with a diameter of 2.5 μm or below (PM_2.5) was 754 mg-PM·kg-meat^-1, accounting for 99% of total suspended particles (TSPs), while that of the marinated pork ribs was 137 mg-PM·kg-meat^-1 (96% of TSPs). Ammonia and acetaldehyde were the most common odors emitted during grilling at 43-88 mg·kg-meat^-1 and 22-30 mg·kg-meat^-1, respectively. Aldehydes were the most significant contributor to total odor intensity (36%-67%). Benzene, vinyl acetate, and hexene were the most abundant VOCs for the pork belly, while butane, vinyl acetate, and n-dodecane were the most abundant for the marinated ribs. Among the VOCs emitted from the pork grilling process, hexene, butane, and toluene were the dominant ozone precursors. The information obtained in this study is useful for furthering the understanding of the characteristics of air pollutants emitted from actual meat-grilling restaurants. Additionally, knowledge of the PM, odor, and VOC emission characteristics and their emission factors is useful for establishing management strategies for air pollutants from meat-grilling restaurants.

Radiomics Study of Thyroid Ultrasound for Predicting BRAF Mutation in Papillary Thyroid Carcinoma: Preliminary Results

BACKGROUND AND PURPOSE

It is not known how radiomics using ultrasound images contribute to the detection of BRAF mutation. This study aimed to evaluate whether a radiomics study of gray-scale ultrasound can predict the presence or absence of B-Raf proto-oncogene, serine/threonine kinase (BRAF) mutation in papillary thyroid cancer.

MATERIALS AND METHODS

The study retrospectively included 96 thyroid nodules that were surgically confirmed papillary thyroid cancers between January 2012 and June 2013. BRAF mutation was positive in 48 nodules and negative in 48 nodules. For analysis, ROIs from the nodules were demarcated manually on both longitudinal and transverse sonographic images. We extracted a total of 86 radiomics features derived from histogram parameters, gray-level co-occurrence matrix, intensity size zone matrix, and shape features. These features were used to build 3 different classifier models, including logistic regression, support vector machine, and random forest using 5-fold cross-validation. The performance including accuracy, sensitivity, specificity, positive predictive value, negative predictive value, and area under the receiver operating characteristic curve, of the different models was evaluated.

RESULTS

The incidence of high-suspicion nodules diagnosed on ultrasound was higher in the BRAF mutation-positive group than in the mutation-negative group (P  =  .004). The radiomics approach demonstrated that all classification models showed moderate performance for predicting the presence of BRAF mutation in papillary thyroid cancers with an area under the curve value of 0.651, accuracy of 64.3%, sensitivity of 66.8%, and specificity of 61.8%, on average, for the 3 models.

CONCLUSIONS

Radiomics study using thyroid sonography is limited in predicting the BRAF mutation status of papillary thyroid carcinoma. Further studies will be needed to validate our results using various diagnostic methods.

Cross-species genetic screens to identify kinase targets for APP reduction in Alzheimer's disease

An early hallmark of Alzheimer's disease is the accumulation of amyloid-β (Aβ), inspiring numerous therapeutic strategies targeting this peptide. An alternative approach is to destabilize the amyloid beta precursor protein (APP) from which Aβ is derived. We interrogated innate pathways governing APP stability using a siRNA screen for modifiers whose own reduction diminished APP in human cell lines and transgenic Drosophila. As proof of principle, we validated PKCβ-a known modifier identified by the screen-in an APP transgenic mouse model. PKCβ was genetically targeted using a novel adeno-associated virus shuttle vector to deliver microRNA-adapted shRNA via intracranial injection. In vivo reduction of PKCβ initially diminished APP and delayed plaque formation. Despite persistent PKCβ suppression, the effect on APP and amyloid diminished over time. Our study advances this approach for mining druggable modifiers of disease-associated proteins, while cautioning that prolonged in vivo validation may be needed to reveal emergent limitations on efficacy.

Porous SnO2 nanostructure with a high specific surface area for improved electrochemical performance

Tin oxide (SnO₂) has been attractive as an alternative to carbon-based anode materials because of its fairly high theoretical capacity during cycling. However, SnO₂ has critical drawbacks, such as poor cycle stability caused by a large volumetric variation during the alloying/de-alloying reaction and low capacity at a high current density due to its low electrical conductivity. In this study, we synthesized a porous SnO₂ nanostructure (n-SnO₂) that has a high specific surface area as an anode active material using the Adams fusion method. From the Brunauer–Emmett–Teller analysis and transmission electron microscopy, the as-prepared SnO₂ sample was found to have a mesoporous structure with a fairly high surface area of 122 m² g⁻¹ consisting of highly-crystalline nanoparticles with an average particle size of 5.5 nm. Compared to a commercial SnO₂, n-SnO₂ showed significantly improved electrochemical performance because of its increased specific surface area and short Li⁺ ion pathway. Furthermore, during 50 cycles at a high current density of 800 mA g⁻¹, n-SnO₂ exhibited a high initial capacity of 1024 mA h g⁻¹ and enhanced retention of 53.6% compared to c-SnO₂ (496 mA h g⁻¹ and 23.5%).

A porous SnO₂ nanostructure as an anode active material showed significantly improved electrochemical performance.

Cycling system for decomposition of gaseous benzene by hydrogen peroxide with naturally Fe-containing activated carbon

For the removal of volatile organic compounds (VOCs) from environmental systems, gaseous benzene, a model VOC, was adsorbed on naturally Fe-containing activated carbon and subsequently, decomposed in the presence of de-ionized water, and low (0.03%, pH 6.5) and high (30%, pH 2.5) concentration H₂O₂ solutions. The intermediates produced during benzene decomposition were analyzed and compared using gas chromatography-mass spectrometry. After the decomposition process, the activated carbon sample was air dried. Three cycles were carried out with de-ionized water and low and high concentration H₂O₂ solutions as oxidants. The adsorption capacity of the activated carbon sample treated with DI water gradually decreased as the number of cycles increased. On the other hand, the benzene adsorption capacity of the activated carbon samples treated with the H₂O₂ solutions was improved due to the relatively higher specific surface areas of these samples. After treatment with the low-concentration H₂O₂ solution, intermediates such as glyoxylic acid, oxalic acid, phenol, malonic acid, and pyrocatechol were observed. After treatment with high-concentration H₂O₂ solution, intermediates such as glyoxylic acid, formic acid, and acetic acid were formed. With increasing H₂O₂ concentration, the number and the molecular weight of the intermediate formed by the oxidative degradation of benzene, simultaneously decreased. The Fenton reaction induced by naturally Fe-containing activated carbon and H₂O₂ could lead to more efficient decomposition of benzene.

For the removal of volatile organic compounds from environmental systems, gaseous benzene, a model VOC, was adsorbed on naturally Fe-containing activated carbon and subsequently, decomposed in the presence of H₂O₂ solution.

Facile one-pot synthesis of Ge/TiO2 nanocomposite structures with improved electrochemical performance

Germanium (Ge) as an alternative to graphite exhibits a fairly high theoretical energy density and improved Li⁺ ion diffusivity. However, the seriously deteriorated electrochemical performance of Ge during cycling and the difficulty in the preparation of Ge-based nanostructures can hinder the utilization of Ge as an anode. Thus, in this study, a nanocomposite structure with Ge and TiO₂ (Ge/TiO₂) was synthesized using a facile one-pot method with different ratios of a Ge source with a dominant GeO₂ phase and titanium isopropoxide. From X-ray diffraction, electron microscopy, and X-ray photoelectron spectroscopy, the Ge/TiO₂ nanocomposites were found to be spherical structures homogeneously consisting of the reduced Ge as an active material and amorphous TiO₂ as a matrix. In particular, the Ge/TiO₂ nanocomposite with an appropriate amount of TiO₂ exhibited improved electrochemical properties, i.e., a coulombic efficiency of 97% and a retention of 61% for 100 cycles, compared to commercial Ge (a coulombic efficiency of 82% and a retention of 16%). This demonstrates that the amorphous TiO₂ matrix could relieve a volumetric expansion of the Ge active material in the nanocomposite electrode generated during the cycling process.

P6534Prognostic implication of serum cystatin C and creatinine-based glomerular filtration rate ratio in coronary disease patients receiving PCI: a surrogate of low muscle mass and a predictor of mortality

Background

Low muscle mass results in impaired exercise capacity and is related with poor prognosis in chronic diseases. Although the ratio of serum creatinine (Scr) to cystatin C (Scys) is known as a surrogate marker of body muscle mass, the value of this marker is unclear in the patients with coronary artery disease (CAD).

Purpose

We assessed the clinical significance of two markers representing body muscle mass, the ratio of Scr to Scys (Scr/Scys), and ratio of estimated glomerular filtration rate by Scys to Scr (eGFRcys/eGFRcr).

Methods

We analyzed patients enrolled in a single tertiary center prospective percutaneous coronary intervention (PCI) registry that had Scr and Scys levels simultaneously measured before PCI. Optimal cut-off values of Scr/Scys and eGFRcys/eGFRcr, and their prognostic impact on 3-year mortality after PCI were analyzed. Subgroup analysis according to various demographics and risk factors was performed.

Results

A total of 1,928 patients who underwent PCI for significant CAD were analyzed (age 65.2±9.9 years, 70.8% men). Both Scr/Scys and eGFRcys/eGFRcr showed strong correlation with estimated proportion of muscle mass. Cut-off values of Scr/Scys discriminating 3-year death were 1.0 for men and 0.8 for women, while those of eGFRcys/eGFRcr were 1.1 for men and 1.0 for women. Both Scr/Scys- and eGFRcys/eGFRcr-based low muscle mass groups showed significantly higher risk of death, after adjusting for 7 selected covariates including age. The additional discriminative power of low muscle mass group on the predictive model was greater in the group determined by eGFRcys/eGFRcr than Scr/Scys. Low eGFRcys/eGFRcr values showed additional prognostic impact especially in patients older than 65 years, non-obese, men, chronic kidney disease, and current smokers.

Conclusions

Low muscle mass was an independent prognostic indicator in the patients who underwent coronary stenting. eGFRcys/eGFRcr was identified as a useful surrogate of muscle mass, which may be used to detect vulnerable patients with low muscle mass at high risk for future events.

Acknowledgement/Funding

None

TiO2-coated LiCoO2 electrodes fabricated by a sputtering deposition method for lithium-ion batteries with enhanced electrochemical performance

We fabricated lithium cobalt oxide (LiCoO₂, LCO) electrodes in the absence and presence of TiO₂ layers as cathodes for lithium-ion batteries (LIBs) using a sputtering deposition method under an Ar atmosphere.

Role of polyvinylpyrrolidone in the electrochemical performance of Li2MnO3 cathode for lithium-ion batteries

While Li₂MnO₃ as an over-lithiated layered oxide (OLO) shows a significantly high reversible capacity of 250 mA h g⁻¹ in lithium-ion batteries (LIBs), it has critical issues of poor cycling performance and deteriorated high rate performance. In this study, modified OLO cathode materials for improved LIB performance were obtained by heating the as-prepared OLO at different temperatures (400, 500, and 600 °C) in the presence of polyvinylpyrrolidone (PVP) under an N₂ atmosphere. Compared to the as-prepared OLO, the OLO sample heated at 500 °C with PVP exhibited a high initial discharge capacity of 206 mA h g⁻¹ and high rate capability of 111 mA h g⁻¹ at 100 mA g⁻¹. The superior performance of the OLO sample heated at 500 °C with PVP is attributed to an improved electronic conductivity and Li⁺ ionic motion, resulting from the formation of the graphitic carbon structure and increased Mn³⁺ ratio during the decomposition of PVP.

The modified OLO cathode materials for improved LIB performance were obtained by heating the as-prepared OLO in the presence of polyvinylpyrrolidone (PVP) under an N₂ atmosphere.

Evaluation of Toluene Adsorption Performance of Mortar Adhesives Using Porous Carbon Material as Adsorbent

Porous carbon materials are advantageous in adsorbing pollutants due to their wide range of specific surface areas, pore diameter, and pore volume. Among the porous carbon materials in the current study, expanded graphite, xGnP, xGnP C-300, xGnP C-500, and xGnP C-750 were prepared as adsorbent materials. Brunauer–Emmett–Teller (BET) analysis was conducted to select the adsorbent material through the analysis of the specific surface area, pore size, and pore volume of the prepared porous carbon materials. Morphological analysis using SEM was also performed. The xGnP C-500 as adsorbent material was applied to a mortar adhesive that is widely used in the installation of interior building materials. The toluene adsorption performances of the specimens were evaluated using 20 L small chamber. Furthermore, the performance of the mortar adhesive, as indicated by the shear bond strength, length change rate, and water retention rate, was analyzed according to the required test method specified in the Korean standards. It was confirmed that for the mortar adhesives prepared using the xGnP C-500 as adsorbent material, the toluene adsorption performance was excellent and satisfied the required physical properties.

Sulfur-Doped Porphyrinic Carbon Nanostructures Synthesized with Amorphous MoS2 for the Oxygen Reduction Reaction in an Acidic Medium

To develop doped carbon nanostructures as non-precious metal cathode catalysts, nanocomposites were synthesized by using SBA-15 and 5,10,15,20-tetrakis(4-methoxyphenyl)porphyrin-iron(III) chloride with different ratios of amorphous MoS₂ precursor. From various analyses, it was found that, during pyrolysis at 900 °C under an N₂ atmosphere, the amorphous MoS₂ precursor decomposed into Mo and S, facilitating the formation of graphene sheet-like carbon with MoC and doping of sulfur in the carbon. In the nanocomposite formed from 10 wt % MoS₂ precursor (denoted as Mo/S/PC-10), most of the MoS₂ was decomposed, thus forming S-doped carbon, which was grown on the MoC phase without crystalline MoS₂ . Furthermore, Mo/S/PC-10 exhibited better performance in the oxygen reduction reaction (specific activity of 1.23 mA cm^-2 at 0.9 V and half-wave potential of 0.864 V) than a commercial Pt catalyst, owing to a heteroatom-doped carbon nanostructure with a fairly high specific surface area. In the polarization curve of the unit-cell performance measured at 80 °C under ambient pressure, Mo/S/PC-10 as a cathode catalyst exhibited an optimal power density of 314 mW cm^-2 and a current density of 280 mA cm^-2 at 0.6 V.

The Endoplasmic Reticulum Chaperone GRP78/BiP Modulates Prion Propagation in vitro and in vivo

Prion diseases are fatal neurodegenerative disorders affecting several mammalian species, characterized by the accumulation of the misfolded form of the prion protein, which is followed by the induction of endoplasmic reticulum (ER) stress and the activation of the unfolded protein response (UPR). GRP78, also called BiP, is a master regulator of the UPR, reducing ER stress levels and apoptosis due to an enhancement of the cellular folding capacity. Here, we studied the role of GRP78 in prion diseases using several in vivo and in vitro approaches. Our results show that a reduction in the expression of this molecular chaperone accelerates prion pathogenesis in vivo. In addition, we observed that prion replication in cell culture was inversely related to the levels of expression of GRP78 and that both proteins interact in the cellular context. Finally, incubation of PrP^Sc with recombinant GRP78 led to the dose-dependent reduction of protease-resistant PrP^Scin vitro. Our results uncover a novel role of GRP78 in reducing prion pathogenesis, suggesting that modulating its levels/activity may offer a novel opportunity for designing therapeutic approaches for these diseases. These findings may also have implications for other diseases involving the accumulation of misfolded proteins.

High-Performance Chemically Regenerative Redox Fuel Cells Using a NO3- /NO Regeneration Reaction

In this study, we proposed high-performance chemically regenerative redox fuel cells (CRRFCs) using NO₃^- /NO with a nitrogen-doped carbon-felt electrode and a chemical regeneration reaction of NO to NO₃^- via O₂ . The electrochemical cell using the nitrate reduction to NO at the cathode on the carbon felt and oxidation of H₂ as a fuel at the anode showed a maximal power density of 730 mW cm^-2 at 80 °C and twofold higher power density of 512 mW cm^-2 at 0.8 V, than the target power density of 250 mW cm^-2 at 0.8 V in the H₂ /O₂ proton exchange membrane fuel cells (PEMFCs). During the operation of the CRRFCs with the chemical regeneration reactor for 30 days, the CRRFCs maintained 60 % of the initial performance with a regeneration efficiency of about 92.9 % and immediately returned to the initial value when supplied with fresh HNO₃ .

Inhibition of microRNA-449a prevents IL-1β-induced cartilage destruction via SIRT1

OBJECTIVE

SIRT1 has anti-inflammatory as well as protective effects in chondrocytes. The object of this study was to investigate whether microRNA-449a regulates expression of SIRT1, which inhibits expression of catabolic genes in IL-1β-induced cartilage destruction.

MATERIALS AND METHODS

MicroRNA-449a expression was determined in OA chondrocytes and IL-1β-induced chondrocytes by real-time PCR. MicroRNA-449a binding sites on the 3'-UTR of SIRT1 mRNA and binding site conservation were examined using microRNA target prediction tools. SIRT1-overexpressing or knockdown chondrocytes were transfected with microRNA-449a or anti-microRNA-449a mimic and stimulated by IL-1β. Expression of catabolic and anabolic genes was examined by real-time PCR and western blotting. Finally, positive effects of anti-microRNA-449a on expression of these genes were confirmed by western analysis of OA chondrocytes.

RESULTS

Expression of microRNA-449a was increased in OA chondrocytes and IL-1β-induced chondrocytes. MMP-13 expression was enhanced, whereas type II collagen and SIRT1 expression were decreased in IL-1β-induced chondrocytes. SIRT1 overexpression resulted in decreased expression of catabolic genes such as MMPs and ADAMTSs in response to IL-1β, but these effects were moderated by microRNA-449a. Suppression of microRNA-449a by anti-microRNA-449a inhibited expression of catabolic genes despite IL-1β stimulation, but these effects were abolished in SIRT1 knockdown chondrocytes. Furthermore, expression of catabolic genes was decreased and expression of type II collagen as well as SIRT1 was restored by anti-microRNA-449a in OA chondrocytes as well as in IL-1β-induced chondrocytes.

CONCLUSION

Silencing of microRNA-449a had a protective effect, inhibiting catabolic gene expression and restoring anabolic gene expression, by targeting SIRT1 in IL-1β-induced cartilage destruction.

Delaying aging in Caenorhabditis elegans with protein aggregation inhibitors

Recent evidence suggests that during aging there is widespread accumulation of aggregated insoluble proteins, even in the absence of pathological conditions. Pharmacological manipulation of protein aggregation might be helpful to unveil the involvement of protein aggregates during aging, as well as to develop novel strategies to delay aging. Here we investigated the effect of known protein aggregation inhibitors on the lifespan and health-span of Caenorhabditis elegans. For this purpose, we selected various structurally diverse anti-aggregation compounds and screened them in liquid and solid medium for their ability to alter the rate of aging in vivo. Our results show that treatment of C. elegans with diverse aggregation inhibitors significantly increases the animal lifespan and health-span. These findings indicate that protein misfolding and aggregation may play an important role in cellular dysfunction during aging, opening a novel approach to increase longevity and enhance the quality of life during aging.