Effects of truncations in the N- and C-terminal domains of filensin on filament formation with phakinin in cell-free conditions and cultured cells

Filensin and phakinin are lens fiber cell-specific proteins that constitute the beaded filaments (BFs) that are critical for maintaining lens transparency. In the Shumiya cataract rat, filensin 94 kDa undergoes N- and C-terminal proteolytic processing to give a transient 50 kDa fragment and a final 38 kDa fragment, just before opacification. To characterize the effects of this processing on filensin function, recombinant proteins representing the two filensin fragments, termed Fil(30-416) and Fil(30-369), respectively, were examined. Fil(30-416) lacks the N-terminal 29 amino acids and the C-terminal 248 amino acids. Fil(30-369) lacks the N-terminal 29 residues and the C-terminal 295 residues. In cell-free assembly characterized by electron microscopy, filensin and Fil(30-416) co-polymerized with phakinin and formed rugged, entangled filaments, whereas Fil(30-369) formed only aggregates. In cultured SW-13 and MCF-7 cells expressing fluorescent fusion proteins, filensin and Fil(30-416) co-polymerized with phakinin and formed cytoplasmic sinuous filaments with different widths, while Fil(30-369) gave aggregates. Therefore, while truncation of the N-terminal 29 amino acids did not affect filament formation, truncation of the C-terminal 295 but not the 248 residues resulted in failure of filament formation. These results indicate that the tail B region (residues 370-416) of rat filensin is essential for filament formation with phakinin. Truncation of the tail B region by proteolytic processing in the cataract rat lens might interfere with BF formation and thereby contribute to opacification.

Growth-related changes in the influence of obesity on signs suggesting sleep-disordered breathing and sleepiness in young individuals with Down syndrome

BACKGROUND

Sleep-disordered breathing (SDB) is highly prevalent in individuals with Down syndrome (DS), who cease growing earlier than individuals without DS. These characteristics may be associated with increased obesity and subsequent SDB signs, such as snoring and apnoea or excessive daytime sleepiness (EDS). Thus, we assessed the influence of growth on the association between obesity and SDB signs or EDS; we used questionnaires sent to young individuals with DS and their caregivers, in a cross-sectional study.

METHODS

We sent out 2000 questionnaires to individuals with DS and their caregivers. The surveys included questions about SDB signs (witnessed snoring or apnoea), subjective sleeping time including witnessed midnight arousal, the Epworth sleepiness scale and witnessed napping as well as sex, age, body weight and body height.

RESULTS

Of the 1222 questionnaires we received, 660 were from young individuals and were included in the analysis. SDB signs were highly prevalent (77.1%), and frequency of SDB signs increased with growth (P-trend: P = 0.02) in individuals with DS. Multivariate analyses showed that EDS (Epworth sleepiness scale > 10 points) was associated with body mass index Z-score (Z-BMI) in the 6-9 years age group (odds ratio [OR] 95% confidence interval [95% CI]: 1.69 [1.09-2.62], P = 0.02). Conversely, SDB signs were associated with Z-BMI in the 13-15 (OR [95% CI]: 1.99 [1.06-3.72], P = 0.03) and 16-18 years age groups (OR [95% CI]: 3.04 [1.22-7.59], P = 0.02). For the 19-21 years age group, SDB signs were associated with only male sex (OR [95% CI]: 7.28 [1.22-43.38], P = 0.03).

CONCLUSIONS

This study showed that the association between Z-BMI and SDB or EDS was age dependent. In early school-age children with DS, high Z-BMI could not accurately predict the presence of SDB, but it was associated with EDS. In the pubescent period (i.e. 13-18 years), high Z-BMI was associated with SDB signs but not with EDS. Overall, obesity affected SDB signs and EDS differently based on age in young individuals with DS.

Constraints on Heavy Decaying Dark Matter from 570 Days of LHAASO Observations

The kilometer square array (KM2A) of the large high altitude air shower observatory (LHAASO) aims at surveying the northern γ-ray sky at energies above 10 TeV with unprecedented sensitivity. γ-ray observations have long been one of the most powerful tools for dark matter searches, as, e.g., high-energy γ rays could be produced by the decays of heavy dark matter particles. In this Letter, we present the first dark matter analysis with LHAASO-KM2A, using the first 340 days of data from 1/2-KM2A and 230 days of data from 3/4-KM2A. Several regions of interest are used to search for a signal and account for the residual cosmic-ray background after γ/hadron separation. We find no excess of dark matter signals, and thus place some of the strongest γ-ray constraints on the lifetime of heavy dark matter particles with mass between 10^{5} and 10^{9}  GeV. Our results with LHAASO are robust, and have important implications for dark matter interpretations of the diffuse astrophysical high-energy neutrino emission.

Impact of grip strength and balance function on the exercise capacity in pulmonary hypertension

Funding Acknowledgements

Type of funding sources: None.

【Background】

Patients with pulmonary hypertension (PH) suffer from poor exercise capacity due to impaired oxygenation or reduced cardiac output. However, the relationship between exercise capacity and physical functions remains unclear.

【Purpose】

The purpose of this study is to investigate the relationship between exercise capacity and physical functions in pulmonary hypertension.

【Methods】

From February 2018 to June 2020, 94 patients (61.3 ± 14.7 years old, 69.1% females) with group 1/3/4/5 PH underwent cardiac catheterization, 6-minute walking distance (6MWD), and physical function measurements simultaneously. The physical functions was measured using muscle strength (grip strength, knee extension muscle strength), balance function (one leg standing time), and short physical performance battery (SPPB). Exercise capacity was measured by 6MWD. 

【Results】

The study cohort consists of 22/8/60/4 (23.4%/8.5%/63.8%/4.3%) patients with group 1/3/4/5 PH, respectively. The average age of each group was 50.7/64.7/63.1/66.0 years old, respectively. A total of 194 measurements of physical functions were evaluated from 94 patients and employed in multivariate logistic regression analysis using adaptive-LASSO methods with the 6MWD (476.2 ± 107.5m) as a dependent variable. WHO functional class (class II: standardized β=-0.35, 95% confidence interval (CI) [-0.54 - -0.16], p < 0.001), class III: β=-0.60, 95%CI [-0.90 - -0.30], p < 0.001), mixed venous oxygen saturation (SvO2: β=0.11, 95%CI [0.03 - 0.19], p = 0.008), pulmonary vascular resistance (PVR: β=-0.16, 95%CI [-0.25 - -0.07], p < 0.001), grip strength (β=0.20, 95%CI [0.09 - 0.31], p < 0.001), one leg standing time (β=0.10, 95%CI [0.00 - 0.20], p = 0.049) , and 4m gait speed test (β=-0.28, 95%CI [-0.36 - -0.19], p < 0.001) were associated with 6MWD.

【Conclusions】

Grip strength and balance function, as well as SvO2 and PVR, were associated with the exercise capacity in pulmonary hypertension.

De novo filament formation by human hair keratins K85 and K35 follows a filament development pattern distinct from cytokeratin filament networks

In human hair follicles, the hair‐forming cells express 16 hair keratin genes depending on the differentiation stages. K85 and K35 are the first hair keratins expressed in cortical cells at the early stage of the differentiation. Two types of mutations in the gene encoding K85 are associated with ectodermal dysplasia of hair and nail type. Here, we transfected cultured SW‐13 cells with human K85 and K35 genes and characterized filament formation. The K85–K35 pair formed short filaments in the cytoplasm, which gradually elongated and became thicker and entangled around the nucleus, indicating that K85–K35 promotes lateral association of short intermediate filaments (IFs) into bundles but cannot form IF networks in the cytoplasm. Of the K85 mutations related to ectodermal dysplasia of hair and nail type, a two‐nucleotide (C¹⁴⁴⁸T¹⁴⁴⁹) deletion (delCT) in the protein tail domain of K85 interfered with the K85–K35 filament formation and gave only aggregates, whereas a missense mutation (233A>G) that replaces Arg⁷⁸ with His (R78H) in the head domain of K85 did not interfere with the filament formation. Transfection of cultured MCF‐7 cells with all the hair keratin gene combinations, K85–K35, K85(R78H)–K35 and K85(delCT)–K35, as well as the individual hair keratin genes, formed well‐developed cytoplasmic IF networks, probably by incorporating into the endogenous cytokeratin IF networks. Thus, the unique de novo assembly properties of the K85–K35 pair might play a key role in the early stage of hair formation.

Characterization of an Intermediate Filament Protein from the Platyhelminth, Dugesia japonica

BACKGROUND

Intermediate Filaments (IFs) are major constituents of the cytoskeletal systems in animal cells.

OBJECTIVE

To gain insights into the structure-function relationship of invertebrate cytoplasmic IF proteins, we characterized an IF protein from the platyhelminth, Dugesia japonica, termed Dif-1.

METHODS

cDNA cloning, in situ hybridization, immunohistochemical analysis, and IF assembly experiments in vitro using recombinant Dif-1, were performed for protein characterization.

RESULTS

The structure deduced from the cDNA sequence showed that Djf-1 comprises 568 amino acids and has a tripartite domain structure (N-terminal head, central rod, and C-terminal tail) that is characteristic of IF proteins. Similar to nuclear IF lamins, Djf-1 contains an extra 42 residues in the coil 1b subdomain of the rod domain that is absent from vertebrate cytoplasmic IF proteins and a nuclear lamin-homology segment of approximately 105 residues in the tail domain; however, it contains no nuclear localization signal. In situ hybridization analysis showed that Djf-1 mRNA is specifically expressed in cells located within the marginal region encircling the worm body. Immunohistochemical analysis showed that Djf-1 protein forms cytoplasmic IFs located close to the microvilli of the cells. In vitro IF assembly experiments using recombinant proteins showed that Djf-1 alone polymerizes into IFs. Deletion of the extra 42 residues in the coil 1b subdomain resulted in the failure of IF formation.

CONCLUSION

Together with data from other histological studies, our results suggest that Djf- 1 is expressed specifically in anchor cells within the glandular adhesive organs of the worm and that Djf-1 IFs may play a role in protecting the cells from mechanical stress.

SAT0262 PROPOSAL FOR OPTIMIZATION OF DIAGNOSTIC IMAGING FOR GIANT CELL ARTERITIS USING THREE-DIMENSIONAL COMPUTED TOMOGRAPHY ANGIOGRAPHY IMAGE AND CONSTRUCTING VASCULAR MAPPING FROM VASCULAR ULTRASONOGRAPHY AS REFERENCES

Background:

The development of rapid and accurate methods of diagnosing giant cell arteritis (GCA) is critical to prevent blindness and stroke, which may develop rapidly in patients with GCA. In 2018, EULAR published recommendations that the first imaging modality for GCA should be vascular ultrasonography without biopsy. However, many institutions still consider biopsy to make an important contribution to the diagnosis of GCA.

Objectives:

Our purpose is to eliminate blindness and stroke among GCA patients by optimizing diagnostic imaging and method to diagnose GCA employed by vascular ultrasonography (V-US), CT Angiography (CTA), MRI/A, and PET/CT without biopsy.

Methods:

We evaluated the clinical and serological characteristics of 20 patients who were diagnosed with GCA at our hospital from 2012 to 2018, and compared the image and biopsy findings of these patients. We then evaluated the effect of optimizing diagnostic imaging and methods for patients with suspected GCA who visited our hospital during 2019. Vascular mapping was carried out using V-US for 3DCTA and other imaging methods as references.

Results:

Table 1 shows the clinical characteristics of the study population. The sensitivity of CTA for GCA was 85.7% (12 of 14 patients), which was the highest of the studied imaging methods. All biopsy-positive cases were diagnosed as GCA, and we compared these cases with cases with positive imaging findings. This revealed that CTA findings were correct (i.e., positive) in 66.7% (four of six patients), MRI/A findings were correct in in 33.3% (three of nine), V-US findings were correct in 50.0% (three of six). Therefore, CTA exhibited the highest sensitivity for positive findings. Comparison of biopsy-positive cases with cases in which imaging findings were negative revealed that CTA findings were correct (negative) in 33.3% (two of six patients), MRI/A findings were correct in 55.6% (five of nine), V-US was correct in 50.0% (three of six). Thus, CTA had the lowest sensitivity for negative findings. Comparison of CTA findings of positive cases with other imaging modalities which reported positive findings revealed MRI/A findings to be correct in 44.4% (four of nine patients), PET/CT findings to be correct in 50.0% (one of two), V-US to be correct in 63.3% (five of eight). Thus, V-US had the highest agreement with CTA. We carried out vascular mapping by V-US using 3DCTA and other imaging methods and produced references to improve the accuracy of diagnosis. Using these references, we diagnosed five cases of GCA among the 20 patients; the positive predictive value of V-US was 80% (four of five patients) and negative predictive value was 86.7% (13 of 15 patients).

Table 1.

Baseline characteristics of the study sample

    

The number of biopsies performed decreased from 50% (10 of 20 patients) from 2012 to 2018 to 15% (3 of 20 patients) in 2019. Two cases in the present study had positive findings in both biopsy and V-US; in one case, biopsy, CTA, and MRI/A were negative while V-US revealed positive findings. No patients with GCA developed blindness or stroke during 2019.

Conclusion:

We propose that V-US should be performed as the first examination for the diagnosis of GCA by the creation of vascular mappings when GCA is suspected in order to prevent blindness and stroke.

References:

[1]Christian Dejaco et al.EULAR recommendations for the use of imaging in large vasculitis in clinical practice.Annals of the Rheumatic Diseases,2018 May;77(5):636-643

[2]Kawamoto T et al.Diagnosis of giant cell arthritis by head-contrast three-dimensional computed tomography angiography.Journal of Medical Case Reports2019 Sep 11;13(1):285.

Figure 1.

Left side is before, right side is after thrapy. (A) 3DCTA finding, (B) determination of V-US arrangement with vascular location to evaluate wall thickening of V-US, compression sign, stenosis and stoppage of vessels.

Disclosure of Interests:

None declared

FRI0179 A STUDY ON THE ACHIEVEMENT OF LUPUS LOW DISEASE ACTIVITY STATE AND QUALITY OF LIFE IN PATIENTS WITH SYSTEMIC LUPUS ERYTHEMATOSUS: FROM THE JUNTENDO UNIVERSITY SLE PROSPECTIVE REGISTRY STUDY

Background:

Systemic lupus erythematosus (SLE) is a chronic autoimmune disease of unknown etiology that affects mostly young women. Multiorgan complications and prolonged treatment significantly cause physical and mental stress in patients. Improving patients’ quality of life (QOL) in SLE treatment is essential. We examined the treatment effects on disease activity and QOL of SLE patients.

Objectives:

In recent years, lupus low disease activity state (LLDAS) has been proposed as a treatment target for SLE. Patients who achieve LLDAS have a low recurrence rate for lupus and a low risk of serious complications (1). The aim of this study is to investigate whether achieving LLDAS reduces not only recurrence rate and complications of SLE but also improves patients’ QOL.

Methods:

A total of 104 SLE patients were enrolled in our prospective SLE registry study (Juntendo, Multi-center, Prospective cohort for investigation of clinical course and outcome in SLE: JUMP) conducted at our institution. SLE was diagnosed using the American College of Rheumatology (ACR) 1982 criteria (revised in 1997). QOL was evaluated using the standard version of the 36-item short form health survey version 2 (SF36v2). Participants were divided into the LLDAS achievement and non-achievement groups, and the characteristics of each group including results of SF36v2 were examined.

Results:

This study included 104 SLE patients, 94 female and 10 male, and the average age and disease duration were 46.4±13.8 and 14.5±11.3 years, respectively. The average corticosteroid dose was 8.0±17.4 mg/day in terms of prednisolone, and anti-dsDNA antibody titer was 16.8±38.5 IU/ml. Of the 104 patients, 57 achieved LLDAS. The subscale’s standard scoring using SF36v2 for role physical (RP) was 78.9±24.0 and 64.6±27.6 (P<0.01), general health (GH) was 50.0±17.0 and 42.0±19.3 (P<0.05), vitality (VT) was 55.8±15.8 and 38.0±24.1 (P<0.01), social functioning (SF) was 82.0±20.7 and 66.5±26.3 (P<0.01), role emotional (RE) was 89.0±16.1 and 73.4±28.1 (P<0.01), and mental health (MH) was 72.4±15.9 and 58.3±21.8 (P<0.01) in the LLDAS achievement and non-achievement groups, respectively. Furthermore, scoring based on the national standard value in the LLDAS achievement group showed that two categories were >50. However, in the LLDAS non-achievement group, all categories were <50. In particular, RP, GH, VT, SF, RE, and MH of the LLDAS achievement group had significantly higher scores than the LLDAS non-achievement group (RP and GH: p<0.05 and VT, SF, RE and MH: p<0.01).

Conclusion:

Results of examining the association between LLDAS and QOL using SF36v2 in SLE patients showed that patients who achieved LLDAS had significantly better standard statistical scores in many subscale categories. Thus, LLDAS achievement as a treatment target for SLE patients greatly contributes to improving patients’ QOL.

References:

[1]Franklyn K, et al. Definition and initial validation of a Lupus Low Disease Activity State (LLDAS).Ann Rheum Dis. 2016 Sep;75(9):1615-21.

Disclosure of Interests:

None declared

Detection of Cross-Correlation between Gravitational Lensing and γ Rays

In recent years, many γ-ray sources have been identified, yet the unresolved component hosts valuable information on the faintest emission. In order to extract it, a cross-correlation with gravitational tracers of matter in the Universe has been shown to be a promising tool. We report here the first identification of a cross-correlation signal between γ rays and the distribution of mass in the Universe probed by weak gravitational lensing. We use data from the Dark Energy Survey Y1 weak lensing data and the Fermi Large Area Telescope 9-yr γ-ray data, obtaining a signal-to-noise ratio of 5.3. The signal is mostly localized at small angular scales and high γ-ray energies, with a hint of correlation at extended separation. Blazar emission is likely the origin of the small-scale effect. We investigate implications of the large-scale component in terms of astrophysical sources and particle dark matter emission.

A nationwide, cross-sectional survey on unusual sleep postures and sleep-disordered breathing-related symptoms in people with Down syndrome

BACKGROUND

People with Down syndrome (DS) often have sleep-disordered breathing (SDB). Unusual sleep postures, such as leaning forward and sitting, are observed in people with DS. This study aimed to clarify the prevalence of unusual sleep postures and their relationships with SDB-related symptoms (SDB-RSs), such as snoring, witnessed apnoea, nocturnal awakening and excessive daytime sleepiness.

METHODS

A questionnaire, including demographic characteristics and the presence of unusual sleep postures, as well as SDB-RSs, was completed by 1149 parents of people with DS from Japan.

RESULTS

Unusual sleep postures were recorded in 483 (42.0%) people with DS. These participants were significantly younger and had a history of low muscle tone more frequently than people without unusual sleep postures. In all ages, the leaning forward posture was more frequent than sitting. People with DS with unusual sleep postures suffered from SDB-RSs. Those who slept in the sitting posture had more frequent SDB-RSs than did those who slept with the leaning forward posture. Snoring, witnessed apnoea and nocturnal awakening were observed in 73.6, 27.2 and 58.2% of participants, respectively. Snoring increased with aging. Witnessed apnoea was more common in males and in those with hypothyroidism than in females and in those without hypothyroidism.

CONCLUSIONS

Our study shows that there is a close relationship between unusual sleep postures and SDB-RSs. We recommend that all people with DS with unusual sleep postures should be checked for the presence of SDB.

Polymorphisms in PTCH1 Affect the Risk of Ameloblastoma

Ameloblastoma is the most common odontogenic tumor, but the genetic nature of the changes in the tumor cells has been unclear. Mutations of CTNNB1 or PTCH1 are observed in many human tumors. Both CTNNB1 and PTCH1 are important in tooth development and are expressed in ameloblastoma. The aim of this study was to investigate whether genetic alterations of CTNNB1 and PTCH1 are present in ameloblastoma. We investigated 14 cases of ameloblastoma. The polymorphisms found in the ameloblastoma patients were further examined in a subsequent case-control study. We found a CTNNB1 mutation in one case of plexiform-type ameloblastoma. CGG triplet repeat-number polymorphism (CGG7/CGG8) in the 5′-untranslated region of PTCH1 was observed. The proportion of CGG8 alleles was significantly higher in the ameloblastoma group. The results of this study indicate a possible relationship between the CGG8 allele in PTCH1 and the risk for ameloblastoma.

Trends in psychological distress and alcoholism after The Great East Japan Earthquake of 2011

AIMS

Many studies have shown that natural disasters affect mental health; however, longitudinal data on post-disaster mental health problems are scarce. The aims of our study were to investigate the trend in psychological distress and alcoholism after The Great East Japan Earthquake and tsunami in north eastern Japan, in March 2011.

METHODS

A longitudinal study was conducted using annual health check data for the general population, in the city of Higashi-Matsushima, which was affected by the high impact of tsunami. In 2012 and 2013, the Kessler Psychological Distress Scale and the CAGE questionnaire (for screening for alcoholism) were used to assess psychological distress and prevalence of alcoholism.

RESULTS

Of 11,855 total eligible residents, 2192 received the annual check in 2012 and 2013. The prevalence of mental illness and the mean score of alcoholism tendency increased during the follow-up period. The majority of respondents (43.8%) with baseline serious mental illness (SMI) continued to have SMI at follow-up; only 16.7% reported recovering. Older age, female sex, and severity of home damage predicted higher psychological distress, while male sex was a risk factor for alcoholism at follow-up.

CONCLUSIONS

Psychological distress deteriorated 2 years after the huge natural disaster, compared with 1 year after the disaster. Long-term mental health care is needed for those affected by natural disasters, particularly those who have suffered loss.

Laser frequency locking with 46 GHz offset using an electro-optic modulator for magneto-optical trapping of francium atoms

We demonstrate frequency offset locking between two laser sources using a waveguide-type electro-optic modulator (EOM) with 10th-order sidebands for magneto-optical trapping of Fr atoms. The frequency locking error signal was successfully obtained by performing delayed self-homodyne detection of the beat signal between the repumping frequency and the 10th-order sideband component of the trapping light. Sweeping the trapping-light and repumping-light frequencies with keeping its frequency difference of 46 GHz was confirmed over 1 GHz by monitoring the Doppler absorption profile of I₂. This technique enables us to search for a resonance frequency of magneto-optical trapping of Fr.

Transportation of a radioactive ion beam for precise laser-trapping experiments

Francium is the heaviest species among the alkali elements. Due to its properties, francium is said to be of advantage in measurements of tiny observations, such as atomic parity violation and electric dipole moment. Before executing experiments with francium, it must be produced artificially because it is one of the most unstable elements. We produced francium with the nuclear fusion reaction of an oxygen beam and gold target, ionized the produced francium through a thermal ionization process, and extracted the ion with electrostatic fields. However, the thermal ionization process is known to ionize not only an objective atom but also other atomic species. Therefore, a Wien filter was installed to analyze the composition of the ion beam and purify the beam. This allowed us to improve the beam purity from ∼10(-6) to ∼10(-3).

Further improvement of the upper limit on the direct 3α decay from the Hoyle state in 12C

The direct 3α decay branch from the 02+ state at Ex=7.65  MeV in 12C, which is known as the Hoyle state, is considered to affect the triple-α reaction rate strongly and to give crucial information on its structure. We have performed a high-precision measurement of the 3α decay from this state using the 12C(12C,3α)12C reaction at E12C=110  MeV. The branching ratio of the direct 3α decay was under the detection limit in the present experiment. By comparing with Monte Carlo simulations for three decay mechanisms as the sequential decay through the ground state of ^{8}Be, the direct decay with equal energies of three α particles, and the direct decay to the phase space uniformly, we have obtained the upper limit of 0.2% on the direct 3α decay.

Suppressive effects of neutrophil by Salp16-like salivary gland proteins from Ixodes persulcatus Schulze tick

Salp16, a 16-kDa tick salivary gland protein, is known to be the molecule involved in the transmission of Anaplasma phagocytophilum, an obligate intracellular pathogen causing zoonotic anaplasmosis, from its mammalian hosts to Ixodes scapularis. Recently, the presence of A. phagocytophilum was documented in Japan and Ixodes persulcatus was identified as one of its vectors. The purpose of this study was to identify Salp16 genes in I. persulcatus and characterize their function. Two cDNA clones encoding the Salp16-like sequences were obtained from the salivary glands of fed female I. persulcatus ticks and designated Salp16 Iper1 and Iper2. Gene expression analyses showed that the Salp16 Iper genes were expressed specifically in the salivary glands and were up-regulated by blood feeding. These proteins attenuated the oxidative burst of activated bovine neutrophils and inhibited their migration induced by the chemoattractant interleukin-8 (IL-8). These results demonstrate that Salp16 Iper proteins contribute to the establishment of blood feeding as an immunosuppressant of neutrophil, an essential factor in innate host immunity. Further examination of the role of Salp16 Iper in the transmission of pathogens, including A. phagocytophilum, will increase our understanding of the tick-host-pathogen interface.

High-frequency affine mechanics and nonaffine relaxation in a model cytoskeleton

The cytoskeleton is a network of crosslinked, semiflexible filaments, and it has been suggested that it has properties of a glassy state. Here we employ optical-trap-based microrheology to apply forces to a model cytoskeleton and measure the high-bandwidth response at an anterior point. Simulating the highly nonlinear and anisotropic stress-strain propagation assuming affinity, we found that theoretical predictions for the quasistatic response of semiflexible polymers are only realized at high frequencies inaccessible to conventional rheometers. We give a theoretical basis for determining the frequency when both affinity and quasistaticity are valid, and we discuss with experimental evidence that the relaxations at lower frequencies can be characterized by the experimentally obtained nonaffinity parameter.

Radioactive ion beam transportation for the fundamental symmetry study with laser-trapped atoms

The search for the violation of the fundamental symmetry in a radioactive atom is the promising candidate for precision tests of the standard model and its possible extensions. The subtle signal arising from the symmetry violation is enhanced in heavy atoms, such as a francium (Fr). To realize high precision measurements, a large amount of radioactive isotopes is required. The Fr is produced via a nuclear fusion reaction using a melted gold target with a (18)O primary beam at Cyclotron and Radioisotope Center, Tohoku University. The maximum extraction efficiency of the Fr ion was achieved at approximately 35%. The beam line consists of an electrostatic deflector, three electrostatic quadrupole triplets to the measurement area at 10 m away from the reaction point, and several beam diagnosis systems. We optimized parameters of the beam line.

In vitro assembly properties of human type I and II hair keratins

Multiple type I and II hair keratins are expressed in hair-forming cells but the role of each protein in hair fiber formation remains obscure. In this study, recombinant proteins of human type I hair keratins (K35, K36 and K38) and type II hair keratins (K81 and K85) were prepared using bacterial expression systems. The heterotypic subunit interactions between the type I and II hair keratins were characterized using two-dimensional gel electrophoresis and surface plasmon resonance (SPR). Gel electrophoresis showed that the heterotypic complex-forming urea concentrations differ depending on the combination of keratins. K35-K85 and K36-K81 formed relatively stable heterotypic complexes. SPR revealed that soluble K35 bound to immobilized K85 with a higher affinity than to immobilized K81. The in vitro intermediate filament (IF) assembly of the hair keratins was explored by negative-staining electron microscopy. While K35-K81, K36-K81 and K35-K36-K81 formed IFs, K35-K85 afforded tight bundles of short IFs and large paracrystalline assemblies, and K36-K85 formed IF tangles. K85 promotes lateral association rather than elongation of short IFs. The in vitro assembly properties of hair keratins depended on the combination of type I and II hair keratins. Our data suggest the functional significance of K35-K85 and K36-K81 with distinct assembly properties in the formation of macrofibrils.

Abstract P5-04-04: CCR5 antagonists block basal breast cancer and prostate cancer metastasis in vivo

The identification of new therapeutic targets and treatments to reduce tumor metastasis homing requires alternative interrogation approaches. The roles of the chemokine CCL5 and its receptor CCR5 in breast cancer progression are controversial. Cancer metastasis is regulated by chemokines in the microenvironment. Chemokines bind to cell surface receptors that belong to the G-protein-coupled receptor family (GPCRs), controlling diverse biological and pathological processes from immune surveillance, inflammation, and cancer. Previous studies of human breast cancer and breast cancer cell lines demonstrated that the chemokine receptors CXCR4 and CCR7 are expressed in breast cancer cells, malignant breast tumors, and metastasis. Their related ligands, CXCL12 (SDF1) and CCL21, are also expressed at the site of metastasis. Subsequent studies identified altered expression of CCL5 (RANTES) in breast cancer patients, correlating with disease progression. CCL5 can be expressed and secreted either by breast cancer cells or by non-malignant stromal cells at the primary or metastatic sites. However, the roles of CCL5 and its receptors in breast cancer are not fully understood. CCL5 facilitates disease progression by recruiting and modulating the activity of inflammatory cells, which subsequently remodel the tumor microenvironment. Accordingly, inhibition of CCR5 by a peptide antagonist reduced leukocyte infiltration and reduced tumor growth after subcutaneous injection of 410.4 mammary carcinoma cells into immunocompetent mice. Our recent microarray analysis of 2,254 human breast cancers demonstrated increased expression of CCL5 and its receptor CCR5, but not CCR3, in the basal and HER-2 genetic subtypes of breast cancer. Interrogation of pathways activated in patient normal breast vs. tumor identified up regulation of a CCR5 signaling module. At the same time, we also extended our research to prostate cancers. Using isogenic oncogene transformed breast and prostate cancer cell lines we show oncogene transformation induces CCR5 expression in breast and prostate epithelial cells. Further we show that the subpopulation of cells that express functional CCR5 display increased invasiveness. Studies in vivo demonstrated that CCR5 promoted metastasis homing. The FDA approved CCR5 antagonists Maraviroc or Vicriviroc, developed to block CCR5 HIV co-receptor function, reduced in vitro invasion of basal breast cancer and prostate cancer cell lines without affecting cell proliferation or viability. In a series of preclinical mouse models, used at equivalent doses to those used in treatment of humans for HIV, Maraviroc decreased breast pulmonary metastasis. The isogenic prostate cancer cell lines metastasized to bones in immune-competent mice representing an ideal model for testing anti-metastasis therapies. CCR5 was expressed in the metastasis in the bones. Maraviroc reduced prostate cancer metastasis to brain, bones and lungs. Our findings provide evidence for a key role of CCL5/CCR5 in the metastasis of basal breast cancer and prostate cancer cell lines and suggest that CCR5 antagonists may be used as an adjuvant therapy to reduce the risk of metastasis in patients with the basal breast cancer subtype and prostate cancer.

Citation Information: Cancer Res 2013;73(24 Suppl): Abstract nr P5-04-04.

Intracellular bacteria recognition contributes to maximal interleukin (IL)-12 production by IL-10-deficient macrophages

Interleukin (IL)-12 is a key factor that induces T helper cell type 1-mediated immunity and inflammatory diseases. In some colitis models, such as IL-10 knock-out (KO) mice, IL-12 triggers intestinal inflammation. An abundant amount of IL-12 is produced by intestinal macrophages in response to stimulation by commensal bacteria in IL-10 KO mice. Intact bacteria are more potent inducers of macrophage IL-12 production than cell surface components in this model. This suggested that cell surface receptor signalling and intracellular pathogen recognition mechanisms are important for the induction of IL-12. We addressed the importance of intracellular recognition mechanisms and demonstrated that signal transducers and activator of transcription 1 (STAT1) signalling activated bacterial phagocytosis and was involved in the induction of abnormal IL-12 production. In IL-10 KO mouse bone marrow-derived (BM) macrophages, Escherichia coli stimulation induced increased IL-12p70 production compared to lipopolysaccharide combined with interferon (IFN)-γ treatment. Significant repression of IL-12 production was achieved by inhibition of phagocytosis with cytochalasin D, and inhibition of de novo protein synthesis with cycloheximide. Induction of IFN regulatory factors-1 and -8, downstream molecules of STAT1 and the key transcription factors for IK-12 transcription, following E. coli stimulation, were mediated by phagocytosis. Interestingly, STAT1 was activated after stimulation with E. coli in IL-10 KO BM macrophages, although IFN-γ could not be detected. These data suggest that molecules other than IFN-γ are involved in hyper-production mechanisms of IL-12 induced by E. coli stimulation. In conclusion, enteric bacteria stimulate excessive IL-12p70 production in IL-10 KO BM macrophages via phagocytosis-dependent signalling.

Abstract P5-06-14: Ezrin Binding Protein Ebp50 Negatively Regulates HER2 and Alters Tamoxifen Sensitivity

Background: Targeted therapy with antiestrogens and aromatase inhibitors are the mainstay of treatment for estrogen receptor (ER) a-positive breast cancer; however, resistance to these therapies ultimately occurs and patients recur with resistant disease.

Materials and Methods: Stable overexpression of a shRNA to Ebp50 or full-length Ebp50 was performed in MCF-7 breast cancer cells. Cell responsiveness to tamoxifen (Tam) was evaluated using soft agar and MTT growth assays. The molecular signaling pathways affected by Ebp50 knockdown were explored using immunoblot analysis, and immunoprecipitation assays. Cellular localization was determined using confocal microscopy.

Results: Modulation of Ebp50 levels altered cellular response to Tam treatment. Overexpression enhanced Tam sensitivity, whereas knockdown decreased Tam sensitivity. Thus reduction in Ebp50 levels analygous to that discovered in resistant patients, conferred resistance to the growth inhibitory effects of Tam. Since it is known that Ebp50 can bind to a number of cell surface receptors, we performed binding assays, and found that Ebp50 was able to bind to HER-2 in MCF-7 cells. In addition, this interaction was enhanced with Tam treatment. Enhanced activation of phospho-HER2 and total-HER2 levels, as well as pAKT were seen in the Ebp50 knockdown cells. We expressed deletion mutants of Ebp50 we saw increased levels of cytoplasmic ERa when the ERM domain was deleted. The ERM domain, which is know to be important for the binding cytoplasmic proteins, may thus be a determinant of ERa localization. Ebp50 was also shown to affect ERa transcriptional activity. Discussion: Our data suggest that Ebp50 may be a negative regulator of HER2 signaling, and its loss confered homrone resistance. Ebp50 loss might function to stabilize HER2 levels.

Citation Information: Cancer Res 2010;70(24 Suppl):Abstract nr P5-06-14.