Inhibition of the mitochondria-shaping protein Opa1 restores sensitivity to Gefitinib in a lung adenocarcinomaresistant cell line

Drug resistance limits the efficacy of chemotherapy and targeted cancer treatments, calling for the identification of druggable targets to overcome it. Here we show that the mitochondria-shaping protein Opa1 participates in resistance against the tyrosine kinase inhibitor gefitinib in a lung adenocarcinoma cell line. Respiratory profiling revealed that oxidative metabolism was increased in this gefitinib-resistant lung cancer cell line. Accordingly, resistant cells depended on mitochondrial ATP generation, and their mitochondria were elongated with narrower cristae. In the resistant cells, levels of Opa1 were increased and its genetic or pharmacological inhibition reverted the mitochondrial morphology changes and sensitized them to gefitinib-induced cytochrome c release and apoptosis. In vivo, the size of gefitinib-resistant lung orthotopic tumors was reduced when gefitinib was combined with the specific Opa1 inhibitor MYLS22. The combo gefitinib-MYLS22 treatment increased tumor apoptosis and reduced its proliferation. Thus, the mitochondrial protein Opa1 participates in gefitinib resistance and can be targeted to overcome it.

Inhibition of the mitochondrial protein Opa1 curtails breast cancer growth

BACKGROUND

Mitochondrial fusion and fission proteins have been nominated as druggable targets in cancer. Whether their inhibition is efficacious in triple negative breast cancer (TNBC) that almost invariably develops chemoresistance is unknown.

METHODS

We used a combination of bioinformatics analyses of cancer genomic databases, genetic and pharmacological Optic Atrophy 1 (OPA1) inhibition, mitochondrial function and morphology measurements, micro-RNA (miRNA) profiling and formal epistatic analyses to address the role of OPA1 in TNBC proliferation, migration, and invasion in vitro and in vivo.

RESULTS

We identified a signature of OPA1 upregulation in breast cancer that correlates with worse prognosis. Accordingly, OPA1 inhibition could reduce breast cancer cells proliferation, migration, and invasion in vitro and in vivo. Mechanistically, while OPA1 silencing did not reduce mitochondrial respiration, it increased levels of miRNAs of the 148/152 family known to inhibit tumor growth and invasiveness. Indeed, these miRNAs were epistatic to OPA1 in the regulation of TNBC cells growth and invasiveness.

CONCLUSIONS

Our data show that targeted inhibition of the mitochondrial fusion protein OPA1 curtails TNBC growth and nominate OPA1 as a druggable target in TNBC.

Direct visualization of the three-dimensional shape of skyrmion strings in a noncentrosymmetric magnet

Magnetic skyrmions are topologically stable swirling spin textures that appear as particle-like objects in two-dimensional (2D) systems. Here, utilizing scalar magnetic X-ray tomography under applied magnetic fields, we report the direct visualization of the three-dimensional (3D) shape of individual skyrmion strings in the room-temperature skyrmion-hosting non-centrosymmetric compound Mn_1.4Pt_0.9Pd_0.1Sn. Through the tomographic reconstruction of the 3D distribution of the [001] magnetization component on the basis of transmission images taken at various angles, we identify a skyrmion string running through the entire thickness of the sample, as well as various defect structures, such as the interrupted and Y-shaped strings. The observed point defect may represent the Bloch point serving as an emergent magnetic monopole, as proposed theoretically. Our tomographic approach with a tunable magnetic field paves the way for direct visualization of the structural dynamics of individual skyrmion strings in 3D space, which will contribute to a better understanding of the creation, annihilation and transfer of these topological objects.

Khorana score at an initial chemotherapy is effective on predicting death in patients with gastrointestinal cancer

Background

The Khorana risk score (KRS) has been recommended for predicting an incidence of cancer-associated thrombosis (CAT). On the other hand, KRS is that the specific gravity of score for the primary tumor is too high and the prevalence of severe obesity is low, so there are some reports that the KRS is not effective in predicting CAT but is effective in predicting death.

Purpose

The purpose of this retrospective cohort study was to evaluate the efficacy of KRS on predicting CAT and all-cause death at an initial chemotherapy in patients with gastrointestinal cancer.

Methods

260 consecutive patients with no history of thrombosis who started an initial chemotherapy for gastrointestinal cancer during a 2-year period from January 2017 to December 2018 in our hospital were divided into 3 groups according to KRS and observed until December 2019 (122 patients (46.9%) in the low-risk group (0 points), 114 patients (43.8%) in the intermediate-risk group (1–2 points), and 24 patients (9.2%) in the high-risk group (3–6 points)). The incidence of CAT and all-cause death was compared among 3 groups.

Results

The median age of the patients was 67 (60–75) years, and 63.5% of them were male. CAT was observed in 61 patients (23.5%), and 84 patients (32.3%) died during the observation period. There was no difference in the incidence rate of CAT among 3 groups (Log-rank P=0.6), but all-cause death was a significant difference among 3 groups (high risk group: 54.2%, intermediate risk group: 36.0%, low risk group: 24.6%, p value=0.0023). After adjustment for multivariate analysis, the KRS high risk group was still significantly associated with death (HR: 2.83, 95% CI: 1.37–5.83, p value =0.0049), but not with CAT.

Conclusion

The Khorana score at an initial of chemotherapy in patients with gastrointestinal cancer is useful in predicting prognosis, but not CAT.

Funding Acknowledgement

Type of funding sources: None.

Unidirectional cooperative binding of fimbrin actin-binding domain 2 to actin filament

Fimbrin forms bundles of parallel actin filaments in filopodia, but it remains unclear how fimbrin forms well-ordered bundles. To address this issue, we focused on the cooperative interaction between the actin-binding domain of fimbrin and actin filaments. First, we loosely immobilized actin filaments on a glass surface via a positively charged lipid layer and observed the binding of GFP-fused actin-binding domain 2 of fimbrin using fluorescence microscopy. The actin-binding domain formed low-density clusters with unidirectional growth along actin filaments. When the actin filaments were tightly immobilized to the surface by increasing the charge density of the lipid layer, cluster formation was suppressed. This result suggests that the propagation of cooperative structural changes of actin filaments evoked by binding of the actin-binding domain was suppressed by a strong physical interaction with the glass surface. Interestingly, binding of the fimbrin actin-binding domain shortened the length of loosely immobilized actin filaments. Based on these results, we propose that fimbrin-actin interactions accompanied by unidirectional long-range allostery help the formation of well-ordered parallel actin filament bundles.

Clinical implication of symptom for long-term outcomes after elective percutaneous coronary intervention

Background

The appropriate treatment for silent myocardial ischemia (SMI) is controversial. The prognosis of asymptomatic patients after percutaneous coronary intervention (PCI) is unknown. Asymptomatic patients might be sicker and have delay of diagnosis when they have coronary events in clinical course. We, thus, hypothesized SMI are associate with the poor outcomes after PCI for stable coronary artery disease (CAD).

Purpose

The present study compared the long-term outcomes of patients with SMI vs. stable angina pectoris (SAP) after elective PCI.

Methods

Our prospective registry database included 923 consecutive patients with CAD who underwent PCI from October 2015 to August 2018. Patients with emergent PCI, acute coronary syndrome at admission, or chronic total occlusion patients were not included. A total 613 patients (71.4±11.2 years, 75.7% male) who underwent elective PCI were studied. The end points included all-cause mortality, non-fatal myocardial infarction, and repeat revascularization.

Results

They were divided into 2 groups according to symptom status: SMI (n=392) and SAP (n=221). SMI patients were predominantly men, and more frequently had diabetes mellitus (197 [50.4%] vs. 91 [41.2%], p=0.028), previous myocardial infarction (44 [11.3%] vs. 8 [3.6%], p=0.001) and heart failure hospitalization.Echocardiography showed SMI groups had reduced ejection fraction (56.9±12.6 vs 63.3±9.1, P<0.001), extended left ventricular internal dimension in diastole (48.5±6.2 vs 47.4±5.8, p=0.048) and left ventricular diameter at end systole (32.8±7.6 vs 30.5±7.5, p=0.001). Mean duration of follow-up was 20.9±10.6 months. The incidence of non-fatal myocardial infarction and repeat revascularization was similar between the 2 groups (10 [2.6%] vs. 5 [2.3%], p=0.82, and 50 [12.8%] vs. 30 [13.6%], p=0.77, respectively). The incidence of all-cause and cardiovascular mortality was more frequent in SMI patients (26 [6.6%] vs. 6 [2.7%], p=0.036, and 9 [3.1%] vs 1 [0.5%], p=0.035, respectively). Kaplan-Meier survival curves indicated that SMI patients had significantly higher all cause-mortality than SAP patients (log-rank, p=0.0184, Hazard ratio 1.24 (1.05–1.47), p=0.013). In multivariable analysis, SMI was an independent predictor of all cause-mortality (Hazard-ratio 5.17, 95% CI 1.35–34.29, p=0.014).

Conclusion

In patients with stable CAD undergoing elective PCI, SMI was associated with an increase in mortality. Optimal care for SMI patients after PCI should be clarified in future studies.

Funding Acknowledgement

Type of funding source: None

Safety and efficacy of a hyperaemic agent, intracoronary nicorandil 4mg, for invasive physiological assessments during fractional flow reserve measurement

Background

Fractional flow reserve (FFR) is one of most reliable index for the determining the functional severity coronary artery stenosis. Adenosine is the most commonly used agent for maximal hyperaemia. However, adenosine can cause chest discomfort, bronchial hyper-reactivity, and atrioventricular block. The aim of this study is to evaluate the safety and efficacy of intracoronary nicorandil as an alternative hyperaemic agent for FFR.

Methods and results

We enrolled consecutive 82 patients (87 lesions) who underwent FFR measurement in our center from Nov. 2018. We compared three groups; intravenous infusion of adenosine (150 μg/kg/min); and adenosine added intracoronary nicorandil 2mg; and intracoronary nicorandil 4mg. Mean FFR value was 0.83±0.09, 0.82±0.09, 0.82±0.08, There was a strong correlation among three groups (R2>0.9). Mean cyclic change in FFR was 0.026±0.023, 0.019±0.010, 0.016±0.014, respectively, cyclic change was smallest in intracoronary nicorandil 4mg group (vs ATP; p<0.001, vs ATP + nicorandil 2mg; p<0.001). By Wilcoxon test, mean FFR value of nicorandil 4mg was significant lower than ATP (p=0.0021), and equal to ATP + nicorandil 2mg (p=0.98).

Conclusions

Intracoronary nicorandil 4mg is a simple, safe, and effective way to induce steady-state hyperaemia for FFR.

Figure 1

Funding Acknowledgement

Type of funding source: None

Changes in nutritional status by recovery phase interventions would be a powerful determinant of cardiovascular prognosis in heart failure patients

Background

Adequate nutrition has been proposed for better cardiovascular prognosis as well as fitness, although the impact of the “changes” in nutrition and fitness at recovery phase on the future prognosis has been unclear.

Purpose

We aimed to examine whether the change in nutritional level as a result of dietary intervention combined with exercise would determine patients' cardiovascular prognosis.

Methods

This study involved 398 consecutive patients who participated in phase II comprehensive cardiac rehabilitation (CCR) for at least three months. All patients underwent cardiopulmonary exercise test (CPX) at the initial and completion periods of CCR. Individual dietary guidance was periodically performed with exercise. Peak oxygen uptake (PVO2) was measured through CPX to evaluate the fitness level, whereas nutritional status was evaluated using the geriatric nutritional risk index (GNRI). Patients were divided in two groups according to the baseline GNRI and the change in GNRI (ΔGNRI) by the median, respectively, to compare their prognosis between groups. Then they were classified into four categories according to the median values of the changes in GNRI (ΔGNRI) and PVO2 (ΔPVO2) during CCR: “Both improved”, “Only GNRI improved”, “Only PVO2 improved” and “Both NOT improved”, to compare MACCE-free rate between categories.

Results

The rate of MACCE showed significant difference between categories (14%, 18%, 19% and 36%, p<0.001), which was approximately 2 times higher in “Both NOT improved” than the others. Kaplan-Meier analysis showed that according to the level of ΔGNRI, “higher ΔGNRI group” showed significantly higher in MACCE-free survival rate than “lower ΔGNRI group” (log rank p=0.010), whereas there was no significant difference according to the baseline GNRI (see figure). According to the categories divided by ΔGNRI and ΔPVO2, MACCE-free rate was significantly lower in “Both NOT improved” (log rank p<0.001) compared to the other categories. Cox proportional hazard regression analysis revealed that “both NOT improved” was an independent predictor of MACCE (hazard ratio, 2.1, 95% confident interval, 1.344–3.175, p<0.001).

Conclusion

Changes in nutritional level would determine patients' cardiovascular prognosis rather than the baseline nutritional level. Non-responders who showed no improvement in nutritional or fitness by interventions may result in a poor cardiovascular outcome.

Funding Acknowledgement

Type of funding source: None

Motion tracking of 80-nm-size skyrmions upon directional current injections

Nanometer-scale skyrmions are prospective candidates for information bits in low-power consumption devices owing to their topological nature and controllability with low current density. Studies on skyrmion dynamics in different classes of materials have exploited the topological Hall effect and current-driven fast motion of skyrmionic bubbles. However, the small current track motion of a single skyrmion and few-skyrmion aggregates remains elusive. Here, we report the tracking of creation and extinction and motion of 80-nm-size skyrmions upon directional one-current pulse excitations at low current density of the order of 109 A m-2 in designed devices with the notched hole. The Hall motion of a single skyrmion and the torque motions of few-skyrmion aggregates have been directly revealed. The results exemplify low-current density controls of skyrmions, which will pave the way for the application of skyrmions.

An fMRI Study of the Brain Network Involved in Teeth Tapping in Elderly Adults

Cortical activity during jaw movement has been analyzed using various non-invasive brain imaging methods, but the contribution of orofacial sensory input to voluntary jaw movements remains unclear. In this study, we used functional magnetic resonance imaging (fMRI) to observe brain activities during a simple teeth tapping task in adult dentulous (AD), older dentulous (OD), and older edentulous subjects who wore dentures (OEd) or did not wear dentures (OE) to analyze their functional network connections. (1) To assess the effect of age on natural activation patterns during teeth tapping, a comparison of groups with natural dentition—AD and OD—was undertaken. A general linear model analysis indicated that the major activated site in the AD group was the primary sensory cortex (SI) and motor cortex (MI) (p < 0.05, family wise error corrected). In the OD group, teeth tapping induced brain activity at various foci (p < 0.05, family wise error corrected), including the SI, MI, insula cortex, supplementary motor cortex (SMC)/premotor cortex (PMA), cerebellum, thalamus, and basal ganglia in each group. (2) Group comparisons between the OD and OEd subjects showed decreased activity in the SI, MI, Brodmann’s area 6 (BA6), thalamus (ventral posteromedial nucleus, VPM), basal ganglia, and insular cortex (p ¡ 0.005, uncorrected). This suggested that the decreased S1/M1 activity in the OEd group was related to missing teeth, which led to reduced periodontal afferents. (3) A conjunction analysis in the OD and OEd/OE groups revealed that commonly activated areas were the MI, SI, cerebellum, BA6, thalamus (VPM), and basal ganglia (putamen; p < 0.05, FWE corrected). These areas have been associated with voluntary movements. (4) Psychophysiological interaction analysis (OEd vs OE) showed that subcortical and cortical structures, such as the MI, SI, DLPFC, SMC/PMA, insula cortex, basal ganglia, and cerebellum, likely function as hubs and form an integrated network that participates in the control of teeth tapping. These results suggest that oral sensory inputs are involved in the control of teeth tapping through feedforward control of intended movements, as well as feedback control of ongoing movements.

Conformational diversity of dynactin sidearm and domain organization of its subunit p150

Dynactin is a principal regulator of the minus-end directed microtubule motor dynein. The sidearm of dynactin is essential for binding to microtubules and regulation of dynein activity. Although our understanding of the structure of the dynactin backbone (Arp1 rod) has greatly improved recently, structural details of the sidearm subcomplex remain elusive. Here, we report the flexible nature and diverse conformations of dynactin sidearm observed by electron microscopy. Using nanogold labeling and deletion mutant analysis, we determined the domain organization of the largest subunit p150 and discovered that its coiled-coil (CC1), dynein-binding domain, adopted either a folded or an extended form. Furthermore, the entire sidearm exhibited several characteristic forms, and the equilibrium among them depended on salt concentrations. These conformational diversities of the dynactin complex provide clues to understanding how it binds to microtubules and regulates dynein.

Final overall survival results of WJTOG3405, a randomized phase III trial comparing gefitinib versus cisplatin with docetaxel as the first-line treatment for patients with stage IIIB/IV or postoperative recurrent EGFR mutation-positive non-small-cell lung cancer

BACKGROUND

Primary analysis of the phase III study WJTOG 3405 demonstrated superiority of progression-free survival (PFS) for gefitinib (G) in patients treated with the epidermal growth factor receptor (EGFR)-tyrosine kinase inhibitor (TKI) gefitinib compared with cisplatin plus docetaxel (CD) as the first-line treatment of stage IIIB/IV or postoperative recurrent EGFR mutation-positive non-small-cell lung cancer. This report presents final overall survival (OS) data.

PATIENTS AND METHODS

Patients were randomized between G (250 mg/day orally) and cisplatin (80 mg/m2 intravenously) plus docetaxel (60 mg/m2 i.v.), administered every 21 days for three to six cycles. After the exclusion of 5 patients, 172 patients (86 in each group, modified intention-to-treat population) were included in the survival analysis. OS was re-evaluated using updated data (data cutoff, 30 September 2013; median follow-up time 59.1 months). The Kaplan-Meier method and the log-rank test were used for analysis, and hazard ratios (HRs) for death were calculated using the Cox proportional hazards model.

RESULTS

OS events in the G group and CD group were 68 (79.1%) out of 86 and 59 (68.6%) out of 86, respectively. Median survival time for G and CD were 34.9 and 37.3 months, respectively, with an HR of 1.252 [95% confidence interval (CI): 0.883-1.775, P = 0.2070]. Multivariate analysis identified postoperative recurrence and stage IIIB/IV disease as independent prognostic factors, with an HR of 0.459 (95% CI: 0.312-0.673, P < 0.001). Median survival time (postoperative recurrence versus stage IIIB/IV disease) were 44.5 and 27.5 months in the G group and 45.5 and 32.8 months in the CD group, respectively.

CONCLUSION

G did not show OS benefits over CD as the first-line treatment. OS of patients with postoperative recurrence was better than that of stage IIIB/IV disease, even though both groups had metastatic disease.This study was registered with UMIN (University Hospital Medical Information Network in Japan), number 000000539.

P2528Responsiveness to nutritional intervention would impact on future cardiovascular prognosis in poor fitness patients

Purpose

Nutritional improvement has been proposed for long-term cardiovascular prognosis as well as fitness recovery. We aimed to examine whether “responsiveness” to nutritional and exercise interventions would impact patients' cardiovascular prognosis even patients in low baseline fitness level.

Methods

We included 254 consecutive patients who participated in the phase II comprehensive cardiovascular rehabilitation (CCR) for at least three months. All patients underwent cardiopulmonary exercise test (CPX) at the initial and completion phases of CCR. Nutritional guidance was periodically performed individually during CCR. Peak oxygen uptake (PVO2) was measured through CPX to evaluate the fitness level, whereas nutritional status was evaluated using the geriatric nutritional risk index (GNRI). Patients were divided into “low fitness” and “normal fitness” groups based on the median of baseline PVO2. Each group was further classified into four categories according to the changes in VO2 and GNRI during CCR: “Both NOT improved”, “Only GNRI improved”, “Only PVO2 improved”, and “Both improved”.

Results

Cox proportional regression analysis showed that the category of “both NOT improved” was an independent predictor for cardiovascular risk among the baseline low fitness group (Hazard ratio: 4.5, p=0.007); whereas no significant difference among the normal fitness group. Kaplan-Meier analysis revealed that the event-free survival rate was significantly lower in the “both NOT improved” category (log rank p=0.002) among the baseline low fitness group (figure); whereas no significant difference among the normal fitness group.

GNRI/PVO2 improvement vs. prognosis

Conclusion

Responsiveness to nutritional and exercise intervention could be a predictive factor of cardiovascular prognosis even in low fitness patients.

Actin-binding domains mediate the distinct distribution of two Dictyostelium Talins through different affinities to specific subsets of actin filaments during directed cell migration

Although the distinct distribution of certain molecules along the anterior or posterior edge is essential for directed cell migration, the mechanisms to maintain asymmetric protein localization have not yet been fully elucidated. Here, we studied a mechanism for the distinct localizations of two Dictyostelium talin homologues, talin A and talin B, both of which play important roles in cell migration and adhesion. Using GFP fusion, we found that talin B, as well as its C-terminal actin-binding region, which consists of an I/LWEQ domain and a villin headpiece domain, was restricted to the leading edge of migrating cells. This is in sharp contrast to talin A and its C-terminal actin-binding domain, which co-localized with myosin II along the cell posterior cortex, as reported previously. Intriguingly, even in myosin II-null cells, talin A and its actin-binding domain displayed a specific distribution, co-localizing with stretched actin filaments. In contrast, talin B was excluded from regions rich in stretched actin filaments, although a certain amount of its actin-binding region alone was present in those areas. When cells were sucked by a micro-pipette, talin B was not detected in the retracting aspirated lobe where acto-myosin, talin A, and the actin-binding regions of talin A and talin B accumulated. Based on these results, we suggest that talin A predominantly interacts with actin filaments stretched by myosin II through its C-terminal actin-binding region, while the actin-binding region of talin B does not make such distinctions. Furthermore, talin B appears to have an additional, unidentified mechanism that excludes it from the region rich in stretched actin filaments. We propose that these actin-binding properties play important roles in the anterior and posterior enrichment of talin B and talin A, respectively, during directed cell migration.

K336I mutant actin alters the structure of neighbouring protomers in filaments and reduces affinity for actin-binding proteins

Mutation of the Lys-336 residue of actin to Ile (K336I) or Asp (K336E) causes congenital myopathy. To understand the effect of this mutation on the function of actin filaments and gain insight into the mechanism of disease onset, we prepared and biochemically characterised K336I mutant actin from Dictyostelium discoideum. Subtilisin cleavage assays revealed that the structure of the DNase-I binding loop (D-loop) of monomeric K336I actin, which would face the adjacent actin-protomer in filaments, differed from that of wild type (WT) actin. Although K336I actin underwent normal salt-dependent reversible polymerisation and formed apparently normal filaments, interactions of K336I filaments with alpha-actinin, myosin II, and cofilin were disrupted. Furthermore, co-filaments of K336I and WT actins also exhibited abnormal interactions with cofilin, implying that K336I actin altered the structure of the neighbouring WT actin protomers such that interaction between cofilin and the WT actin protomers was prevented. We speculate that disruption of the interactions between co-filaments and actin-binding proteins is the primary reason why the K336I mutation induces muscle disease in a dominant fashion.

Comparison of posterior alveolar canal location measured on computer tomography scan with cadaveric measurement of posterior superior alveolar foramen in Japanese samples

The aim of this study was to analyse anatomical characteristics of the most posterior alveolar canal (PAC) on computed tomography (CT) images and the posterior superior alveolar foramen (PSAF) physically identified in cadaveric samples, to avoid injuring the posterior superior alveolar artery (PSAA) during surgery in the maxillary tuberosity region. The study included 125 hemi-heads of 64 Japanese cadavers. Simple CT data of the maxillary bone region of the samples were obtained and analysed using measurement software. The alveolar crest (AC) and the PAC were identified to calculate the shortest distance between the AC and the PAC (AC-PAC). Then the samples were dissected to measure physically the shortest distance between the AC and the PSAF (AC-PSAF). The data were analysed statistically. The mean value and standard deviation were 20.7±4.2mm for AC-PAC and 20.7±4.3mm for AC-PSAF. The intraclass correlation coefficient between AC-PAC and AC-PSAF was 0.98. The CT-measured PAC locations were found to be almost identical to the PSAF positions identified physically in the samples. Preoperative CT localization of the PAC aids in avoiding injury to PSAA, while preoperative CT evaluation is important for each case due to significant individual variability in the anatomical PAC and PSAF locations.

Thermal behavior, structure, dynamic properties of aqueous glycine solutions confined in mesoporous silica MCM-41 investigated by x-ray diffraction and quasi-elastic neutron scattering

Differential scanning calorimetry, X-ray diffraction, and quasi-elastic neutron scattering (QENS) measurements of aqueous glycine solutions confined in mesoporous silica (MCM-41) were performed at different glycine concentrations, pH, and loading ratio (=mass of glycine solution/mass of dry MCM-41) in the temperature range from 305 to 180 K to discuss the confinement effect on the thermal behavior, the structure, and the dynamic properties of the solutions. The freezing points of the confined glycine solutions decreased, compared with those of the bulk solutions. The corresponding exothermic peak due to ice formation became broader with an increase in the glycine concentration. By subtracting X-ray diffraction patterns of dry MCM-41 from those of glycine solution-loaded MCM-41, information about the structure of the confined glycine solutions was obtained. The radial distribution functions of the confined glycine solutions showed that the peaks assigned to the interaction between glycine molecules and the surface silanol (Si-OH) groups of MCM-41 at pH = 5 were observed, in contrast to the case at pH = 2. The QENS data on H/D substituted aqueous glycine solutions gave the translational diffusion coefficients and the residence time of glycine and water molecules confined in MCM-41 individually. The activation energy of the diffusion coefficient of a glycine molecule at pH = 5 was larger than that at pH = 2. These results imply that glycine molecules locate near the pore surface of MCM-41 due to the formation of hydrogen bonding between glycine molecules and the silanol group of the MCM-41 wall at pH = 5.

Circular orientation fluorescence emitter imaging (COFEI) of rotational motion of motor proteins

Single-molecule fluorescence polarization technique has been utilized to detect structural changes in biomolecules and intermolecular interactions. Here we developed a single-molecule fluorescence polarization measurement system, named circular orientation fluorescence emitter imaging (COFEI), in which a ring pattern of an acquired fluorescent image (COFEI image) represents an orientation of a polarization and a polarization factor. Rotation and pattern change of the COFEI image allow us to find changes in the polarization by eye and further values of the parameters of a polarization are determined by simple image analysis with high accuracy. We validated its potential applications of COFEI by three assays: 1) Detection of stepwise rotation of F₁-ATPase via single quantum nanorod attached to the rotary shaft γ; 2) Visualization of binding of fluorescent ATP analog to the catalytic subunit in F₁-ATPase; and 3) Association and dissociation of one head of dimeric kinesin-1 on the microtubule during its processive movement through single bifunctional fluorescent probes attached to the head. These results indicate that the COFEI provides us the advantages of the user-friendly measurement system and persuasive data presentations.

Activation of NLRP3 inflammasome in macrophages by mycoplasmal lipoproteins and lipopeptides

The NLRP3 inflammasome, an intracellular sensor consisting of the nucleotide-binding oligomerization domain-like receptor family, pyrin domain containing 3 (NLRP3), the adaptor protein apoptosis-associated speck-like protein containing a caspase-recruitment domain (ASC), and procaspase-1, plays critical roles in host defense against microbial pathogens by inducing production of interleukin-1β (IL-1β) and IL-18. Mycoplasma salivarium and Mycoplasma pneumoniae cells activated murine bone marrow-derived macrophages (BMMs) to induce production of IL-1α, IL-1β, and IL-18. The IL-1β production-inducing activities of these mycoplasmas toward BMMs from Toll-like receptor 2 (TLR2)-deficient mice were significantly attenuated compared with those from C57BL/6 mice (B6BMMs). This result suggests the possibility that their lipoproteins as TLR2 agonists are involved in the activity. Lipoproteins of M. salivarium and M. pneumoniae (MsLP and MpLP), and the M. salivarium-derived lipopeptide FSL-1 induced IL-1β production by B6BMMs, but not by BMMs from caspase-1-, NLRP3- or ASC-deficient mice. The activities of MsLP and MpLP were not downregulated by the proteinase K treatment, suggesting that the active sites are their N-terminal lipopeptide moieties. B6BMMs internalized the mycoplasmal N-terminal lipopeptide FSL-1 at least 30 min after incubation, FSL-1-containing endosomes started to fuse with the lysosomes around 2 hours, and then FSL-1 translocated into the cytosol from LAMP-1⁺ endosomes. The artificial delivery of FSL-1 into the cytosol of B6BMMs drastically enhanced the IL-1β production-inducing activity. FSL-1 as well as the representative NLRP3 inflammasome activator nigericin induced the NLRP3/ASC speck, but FSL-1 located in a compartment different from the NLRP3/ASC speck.

Liquid-like thermal conduction in intercalated layered crystalline solids

As a generic property, all substances transfer heat through microscopic collisions of constituent particles ¹ . A solid conducts heat through both transverse and longitudinal acoustic phonons, but a liquid employs only longitudinal vibrations^2,3. As a result, a solid is usually thermally more conductive than a liquid. In canonical viewpoints, such a difference also serves as the dynamic signature distinguishing a solid from a liquid. Here, we report liquid-like thermal conduction observed in the crystalline AgCrSe₂. The transverse acoustic phonons are completely suppressed by the ultrafast dynamic disorder while the longitudinal acoustic phonons are strongly scattered but survive, and are thus responsible for the intrinsically ultralow thermal conductivity. This scenario is applicable to a wide variety of layered compounds with heavy intercalants in the van der Waals gaps, manifesting a broad implication on suppressing thermal conduction. These microscopic insights might reshape the fundamental understanding on thermal transport properties of matter and open up a general opportunity to optimize performances of thermoelectrics.

Low-Field Bi-Skyrmion Formation in a Noncentrosymmetric Chimney Ladder Ferromagnet

The real-space spin texture and the relevant magnetic parameters were investigated for an easy-axis noncentrosymmetric ferromagnet Cr_{11}Ge_{19} with Nowotny chimney ladder structure. Using Lorentz transmission electron microscopy, we report the formation of bi-Skyrmions, i.e., pairs of spin vortices with opposite magnetic helicities. The quantitative evaluation of the magnetocrystalline anisotropy and Dzyaloshinskii-Moriya interaction (DMI) proves that the magnetic dipolar interaction plays a more important role than the DMI on the observed bi-Skyrmion formation. Notably, the critical magnetic field value required for the formation of bi-Skyrmions turned out to be extremely small in this system, which is ascribed to strong easy-axis anisotropy associated with the characteristic helix crystal structure. The family of Nowotny chimney ladder compounds may offer a unique material platform where two distinctive Skyrmion formation mechanisms favoring different topological spin textures can become simultaneously active.

Effects of ionic liquids on the nanoscopic dynamics and phase behaviour of a phosphatidylcholine membrane

Ionic liquids (ILs) are potential candidates for new antimicrobials due to their tunable antibacterial and antifungal properties that are required to keep pace with the growing challenge of bacterial resistance. To a great extent their antimicrobial actions are related to the interactions of ILs with cell membranes. Here, we report the effects of ILs on the nanoscopic dynamics and phase behaviour of a dimyristoylphosphatidylcholine (DMPC) membrane, a model cell membrane, as studied using neutron scattering techniques. Two prototypical imidazolium-based ILs 1-butyl-3-methylimidazolium tetrafluoroborate (BMIM[BF4]) and 1-decyl-3-methylimidazolium tetrafluoroborate (DMIM[BF4]), which differ only in terms of the alkyl chain length of cations, have been used for the present study. Fixed Elastic Window Scan (FEWS) shows that the incorporation of ILs affects the phase behaviour of the phospholipid membrane significantly and the transition from a solid gel to a fluid phase shifts to lower temperature. This is found to be consistent with our differential scanning calorimetry measurements. DMIM[BF4], which has a longer alkyl chain cation, affects the phase behaviour more strongly in comparison to BMIM[BF4]. The pressure-area isotherms of the DMPC monolayer measured at the air-water interface show that in the presence of ILs, isotherms shift towards higher area-per lipid molecule. DMIM[BF4] is found to shift the isotherm to a greater extent compared to BMIM[BF4]. Quasielastic neutron scattering (QENS) data show that both ILs act as a plasticizer, which enhances the fluidity of the membrane. DMIM[BF4] is found to be a stronger plasticizing agent in comparison to BMIM[BF4] that has a cation with a shorter alkyl chain. The incorporation of DMIM[BF4] enhances not only the long range lateral motion but also the localised internal motion of the lipids. On the other hand, BMIM[BF4] acts weakly in comparison to DMIM[BF4] and mainly alters the localised internal motion of the lipids. Any subtle change in the dynamical properties of the membrane can profoundly affect the stability of the cell. Hence, the dominant effect of the IL with the longer chain length on the dynamics of the phospholipid membrane might be correlated with its cytotoxic activity. QENS data analysis has provided a quantitative description of the effects of the two imidazolium-based ILs on the dynamical and phase behaviour of the model cell membrane, which is essential for a detailed understanding of their action mechanism.

Accuracy of self-reported height, weight and waist circumference in a Japanese sample

Objective

Inconsistent results have been found in prior studies investigating the accuracy of self‐reported waist circumference, and no study has investigated the validity of self‐reported waist circumference among Japanese individuals. This study used the diagnostic standard of metabolic syndrome to assess the accuracy of individual's self‐reported height, weight and waist circumference in a Japanese sample.

Methods

Study participants included 7,443 Japanese men and women aged 35–79 years. They participated in a cohort study's baseline survey between 2007 and 2011. Participants' height, weight and waist circumference were measured, and their body mass index was calculated. Self‐reported values were collected through a questionnaire before the examination.

Results

Strong correlations between measured and self‐reported values for height, weight and body mass index were detected. The correlation was lowest for waist circumference (men, 0.87; women, 0.73). Men significantly overestimated their waist circumference (mean difference, 0.8 cm), whereas women significantly underestimated theirs (mean difference, 5.1 cm). The sensitivity of self‐reported waist circumference using the cut‐off value of metabolic syndrome was 0.83 for men and 0.57 for women.

Conclusions

Due to systematic and random errors, the accuracy of self‐reported waist circumference was low. Therefore, waist circumference should be measured without relying on self‐reported values, particularly in the case of women.

Electrical magnetochiral effect induced by chiral spin fluctuations

Chirality of matter can produce unique responses in optics, electricity and magnetism. In particular, magnetic crystals transmit their handedness to the magnetism via antisymmetric exchange interaction of relativistic origin, producing helical spin orders as well as their fluctuations. Here we report for a chiral magnet MnSi that chiral spin fluctuations manifest themselves in the electrical magnetochiral effect, i.e. the nonreciprocal and nonlinear response characterized by the electrical resistance depending on inner product of current and magnetic field. Prominent electrical magnetochiral signals emerge at specific temperature-magnetic field-pressure regions: in the paramagnetic phase just above the helical ordering temperature and in the partially-ordered topological spin state at low temperatures and high pressures, where thermal and quantum spin fluctuations are conspicuous in proximity of classical and quantum phase transitions, respectively. The finding of the asymmetric electron scattering by chiral spin fluctuations may explore new electromagnetic functionality in chiral magnets.

The magnetism-induced chirality in electron transportation is of fundamental importantance in condensed matter physics but the origin is still unclear. Here the authors demonstrate that the asymmetric electron scattering by chiral spin fluctuations can be the key to the electrical magnetochiral effect in MnSi.

Temperature and Magnetic Field Dependence of the Internal and Lattice Structures of Skyrmions by Off-Axis Electron Holography

The internal and lattice structures of magnetic Skyrmions in B20-type FeGe are investigated using off-axis electron holography. The temperature, magnetic field, and angular dependence of the magnetic moments of individual Skyrmions are analyzed. The internal Skyrmion shape is found to vary with applied magnetic field. In contrast, the inter-Skyrmion distance remains almost unchanged in the lattice phase over the studied range of applied field. The amplitude of the local magnetic moment is found to vary with temperature, while the Skyrmion shape does not change significantly. Deviations from a circular to a hexagonal Skyrmion structure are observed in the lattice phase, in agreement with the results of micromagnetic simulations.

Actin binding domain of filamin distinguishes posterior from anterior actin filaments in migrating Dictyostelium cells

Actin filaments in different parts of a cell interact with specific actin binding proteins (ABPs) and perform different functions in a spatially regulated manner. However, the mechanisms of those spatially-defined interactions have not been fully elucidated. If the structures of actin filaments differ in different parts of a cell, as suggested by previous in vitro structural studies, ABPs may distinguish these structural differences and interact with specific actin filaments in the cell. To test this hypothesis, we followed the translocation of the actin binding domain of filamin (ABD_FLN) fused with photoswitchable fluorescent protein (mKikGR) in polarized Dictyostelium cells. When ABD_FLN-mKikGR was photoswitched in the middle of a polarized cell, photoswitched ABD_FLN-mKikGR rapidly translocated to the rear of the cell, even though actin filaments were abundant in the front. The speed of translocation (>3 μm/s) was much faster than that of the retrograde flow of cortical actin filaments. Rapid translocation of ABD_FLN-mKikGR to the rear occurred normally in cells lacking GAPA, the only protein, other than actin, known to bind ABD_FLN. We suggest that ABD_FLN recognizes a certain feature of actin filaments in the rear of the cell and selectively binds to them, contributing to the posterior localization of filamin.

Functional status of the articularis genus muscle in individuals with knee osteoarthritis

OBJECTIVES

To clarify the functional status of the articularis genus muscle (AGM) in individuals with knee osteoarthritis (OA) and to analyze the muscle's relationship with knee OA.

METHODS

Fifty-two individuals with knee OA (mean age, 73.4 years), 50 elderly individuals without knee OA changes (mean age, 71.2 years) and 75 young individuals (mean age, 20.2 years) were observed the AGM using ultrasonography. The thickness of the AGM, the anteroposterior distance of the suprapatellar bursa, and moving distance of the muscle insertion were measured both at rest and during isometric contraction, and values during contraction were expressed as percentages of the values at rest (%Muscle-Increase, %Bursa-Increase).

RESULTS

Muscle thickness at rest, %Muscle-Increase, %Bursa-Increase, and moving distance of the muscle insertion were significantly lower and anteroposterior distance of the suprapatellar bursa was significantly higher in the OA group than in the controls (p<0.001, all). In the OA group, these values for the AGM were significantly correlated with knee range of motion, knee pain, and Kellgren and Lawrence grade.

CONCLUSIONS

Individuals with knee OA exhibited atrophic changes and dysfunctions of the AGM, and these were associated with symptoms. Atrophic changes and dysfunctions of the AGM may be specific changes associated with knee OA.

Toll-like Receptors, NOD1, and NOD2 in Oral Epithelial Cells

Oral epithelium might be the first barrier against oral bacteria in periodontal tissue. We hypothesized that oral epithelium is endowed with innate immune receptors for bacterial components, which play roles in host defense against bacterial infection without being accompanied by excessive inflammatory responses. We found clear expression of Toll-like receptor (TLR)4 as well as TLR2, and strong expression of NOD1 and NOD2 in normal oral epithelial tissues by immunohistochemical analysis. We also showed that primary oral epithelial cells in culture expressed these molecules using PCR, flow cytometry, and immunostaining. In inflamed oral epithelium, cell-surface localizations of TLR2 and TLR4 were more clearly observed than in healthy tissue. Upon stimulation with synthetic ligands for these receptors, the expression of β-defensin 2 was markedly up-regulated. These findings indicate that these molecules in oral epithelial cells are functional receptors that induce antibacterial responses.

Oscillation in tissue oxygen index during recovery from exercise

It was hypothesized that an oscillation of tissue oxygen index (TOI) determined by near-infrared spectroscopy during recovery from exercise occurs due to feedback control of adenosine triphosphate and that frequency of the oscillation is affected by blood pH. In order to examine these hypotheses, we aimed 1) to determine whether there is an oscillation of TOI during recovery from exercise and 2) to determine the effect of blood pH on frequency of the oscillation of TOI. Three exercises were performed with exercise intensities of 30 % and 70 % peak oxygen uptake (V(.)o(2)peak) for 12 min and with exercise intensity of 70 % V(.)o(2)peak for 30 s. TOI during recovery from the exercise was analyzed by fast Fourier transform in order to obtain power spectra density (PSD). There was a significant difference in the frequency at which maximal PSD of TOI appeared (Fmax) between the exercises with 70 % V(.)o(2)peak for 12 min (0.0039+/-0 Hz) and for 30 s (0.0061+/-0.0028 Hz). However, there was no significant difference in Fmax between the exercises with 30 % (0.0043+/-0.0013 Hz) and with 70 % V(.)o(2)peak for 12 min despite differences in blood pH and blood lactate from the warmed fingertips. It is concluded that there was an oscillation in TOI during recovery from the three exercises. It was not clearly shown that there was an effect of blood pH on Fmax.

Influence of ABCB1 and ABCG2 polymorphisms on the antiemetic efficacy in patients with cancer receiving cisplatin-based chemotherapy: a TRIPLE pharmacogenomics study

Resistance to antiemetic treatment with 5-hydroxytryptamine-3 receptor antagonist is an issue. This study evaluated the potential roles of ABCB1 and ABCG2 polymorphisms in antiemetic treatment resistance in patients with cancer previously enrolled in a randomized controlled trial. A total of 156 patients were evaluated for their responses to antiemetic therapy and then subdivided into granisetron or palonosetron groups. The genotypes were evaluated for their association with antiemetic efficacy in each treatment groups. Additional risk factors associated with complete response (CR) were examined using a multivariate regression analysis. No significant associations were identified for genetic polymorphisms in the palonosetron group. In the granisetron group, patients with ABCB1 2677TT and 3435TT genotypes had higher proportion of CR. In addition to ABCB1 polymorphisms, gender and cisplatin dose were associated with granisetron response by univariate analysis. Multivariate logistic regression analysis revealed that the ABCB1 3435C>T polymorphism and cisplatin dose were significant predictors of CR.

Abstract P3-01-18: Validation of a novel diagnostic kit using the semi-dry dot-blot method for detecting metastatic lymph nodes in breast cancer

Background: The semi-dry dot-blot (SDB) method is a diagnostic procedure for detecting lymph node (LN) metastases. The metastases are visualized by the presence of cytokeratin (CK) with lavage fluid of sectioned LNs by anti-pancytokeratin antibody, based on the theory that epithelial components such as CK are not found in normal LNs. We previously reported 93.3% sensitivity, 96.9% specificity, and 96.6% accuracy for this method in detecting metastasis in sentinel LNs, compared with permanent pathological diagnosis in breast cancer. In this study, we evaluated a novel kit that applies the SDB method using the newly developed anti-CK19 antibody for diagnosing LN metastases in breast cancer.

Methods: We obtained 141 LNs dissected from 81 breast cancer patients from July 2013 to April 2015 at Nagasaki University Hospital and the Japanese Red Cross Nagasaki Genbaku Hospital, including 33 dissected axillary LNs and 108 sentinel LNs, which were sliced at 2-mm intervals and washed with phosphate-buffered saline. The suspended cells in the lavage fluid of sliced LNs were centrifuged to collect the cell pellet and lysed with lysis buffer to extract protein. This extracted protein was used with the kit to diagnose LN metastasis. The washed LNs were blindly diagnosed by pathologists using hematoxylin and eosin (H&E) stain. Diagnoses based on the kit were compared with their H&E counterparts.

Results: Of the 141 LNs, 57 were assessed as positive and 84 as negative by permanent pathological examination with H&E. Use of the kit resulted in correct diagnoses in 46 of the 57 pathologically positive cases and all of pathologically negative cases. Sensitivity, specificity and accuracy of the kit in detecting LN metastases were 80.7% (95% confidence interval [95% CI]: 75.6–80.7%), 100% (95% CI: 96.5–100%), and 92.2% (95% CI: 88.1–92.2%), respectively. In 11 false-negative cases, there were 9 micrometastases; therefore, sensitivity was 95.5% (95% CI: 90.1–95.5%) in cases of macrometastases. Diagnosis was achieved in approximately 20 min using the kit, reducing the diagnostic time by half compared with the original SDB method. The cost of this kit was within 8 USD, and we are currently developing an improved kit for the detection of smaller metastases.

Conclusions: The kit in our study is accurate, quick, and cost-effective in diagnosing LN metastases without the loss of LN tissue. Its sensitivity in detecting macrometastases is excellent, which is important in clinical practice.

Citation Format: Otsubo R, Hirakawa H, Oikawa M, Shibata K, Tanaka A, Matsumoto M, Yano H, Nagayasu T. Validation of a novel diagnostic kit using the semi-dry dot-blot method for detecting metastatic lymph nodes in breast cancer. [abstract]. In: Proceedings of the Thirty-Eighth Annual CTRC-AACR San Antonio Breast Cancer Symposium: 2015 Dec 8-12; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2016;76(4 Suppl):Abstract nr P3-01-18.

Oscillation of tissue oxygen index in non-exercising muscle during exercise

The purpose of the present study was to examine how oscillation of tissue oxygen index (TOI) in non-exercising exercise is affected during high-intensity and low-intensity exercises. Three exercises were performed with exercise intensities of 30% and 70% peak oxygen uptake (Vo(2)peak) for 12 min and with exercise intensity of 70% Vo(2)peak for 30 s. TOI in non-exercising muscle (biceps brachii) during the exercises for 12 min was determined by nearinfrared spectroscopy. TOI in the non-exercising muscle during the exercises was analyzed by fast Fourier transform (FFT) to obtain power spectra density (PSD). The frequency at which maximal PSD appeared (Fmax) during the exercise with 70% Vo(2)peak for 12 min (0.00477 ± 0.00172 Hz) was significantly lower than that during the exercise with 30% Vo2peak for 12 min (0.00781 ± 0.00338 Hz). There were significant differences in blood pH and blood lactate between the exercise with 70% Vo(2)peak and the exercise with 30% Vo(2)peak. It is concluded that TOI in nonexercising muscle oscillates during low-intensity exercise as well as during high-intensity exercise and that the difference in Fmax between the two exercises is associated with the difference in increase in blood lactate derived from the exercise.

Activation of inflammasomes in dendritic cells and macrophages by Mycoplasma salivarium

Interleukin-1β (IL-1β) plays crucial roles in the pathogenesis of periodontal disease. It is produced after the processing of pro-IL-1β by caspase-1, which is activated by the inflammasome-a multiprotein complex comprising nucleotide-binding domain leucine-rich repeat-containing receptor (NLR), the adaptor protein apoptosis-associated speck-like protein containing a caspase-recruitment domain (ASC), and procaspase-1. Mycoplasma salivarium preferentially inhabits the gingival sulcus and the incidence and number of organisms in the oral cavity increase significantly with the progression of periodontal disease. To initially clarify the association of this organism with periodontal diseases, this study determined whether it induces IL-1β production by innate immune cells such as dendritic cells or macrophages by using Mycoplasma pneumoniae as a positive control. Both live and heat-killed M. salivarium and M. pneumoniae cells induced IL-1β production by XS106 murine dendritic cells as well as pyroptosis. The activities were significantly downregulated by silencing of caspase-1. Bone-marrow-derived macrophage (BMMs) from wild-type and NLR-containing protein 3 (NLRP3)-, ASC-, and caspase-1-deficient mice were examined for IL-1β production in response to these mycoplasmas. Live M. salivarium and M. pneumoniae cells almost completely lost the ability to induce IL-1β production by BMMs from ASC- and caspase-1-deficient mice. Their activities toward BMMs from NLRP3-deficient mice were significantly but not completely attenuated. These results suggest that live M. salivarium and M. pneumoniae cells can activate several types of inflammasomes including the NLRP3 inflammasome. Both M. salivarium and M. pneumoniae cells can activate THP-1 human monocytic cells to induce IL-1β production. Hence, the present finding that M. salivarium induces IL-1β production by dendritic cells and macrophages may suggest the association of this organism with periodontal diseases.