E3MPH16: An efficient endosomolytic peptide for intracellular protein delivery

To facilitate the introduction of proteins, such as antibodies, into cells, a variety of delivery peptides have been engineered. These peptides are typically highly cationic and somewhat hydrophobic, enabling cytosolic protein delivery at the cost of causing cell damage by rupturing membranes. This balance between delivery effectiveness and cytotoxicity presents obstacles for their real-world use. To tackle this problem, we designed a new endosome-disruptive cytosolic delivery peptide, E3MPH16, inspired by mastoparan X (MP). E3MPH16 was engineered to incorporate three Glu (E3) and 16 His (H16) residues at the N- and C-termini of MP, respectively. The negative charges of E3 substantially mitigate the cell-surface damage induced by MP. The H16 segment is known to enhance cell-surface adsorption and endocytic uptake of the associated molecules. With these modifications, E3MPH16 was successfully trapped within endosomes. The acidification of endosomes is expected to protonate the side chains of E3 and H16, enabling E3MPH16 to rupture endosomal membranes. As a result, nearly 100% of cells achieved cytosolic delivery of a model biomacromolecule, Alexa Fluor 488-labeled dextran (10 kDa), via endosomal escape by co-incubation with E3MPH16. The delivery process also suggested the involvement of macropinocytosis and caveolae-mediated endocytosis. With the assistance of E3MPH16, Cre recombinase and anti-Ras-IgG delivered into HEK293 cells and HT1080 cells enabled gene recombination and inhibited cell proliferation, respectively. The potential for in vivo application of this intracellular delivery method was further validated by topically injecting the green fluorescent protein fused with a nuclear localization signal (NLS-GFP) along with E3MPH16 into Colon-26 tumor xenografts in mice.

Many Models, Little Adoption-What Accounts for Low Uptake of Machine Learning Models for Atrial Fibrillation Prediction and Detection?

(1) Background: Atrial fibrillation (AF) is a major risk factor for stroke and is often underdiagnosed, despite being present in 13-26% of ischemic stroke patients. Recently, a significant number of machine learning (ML)-based models have been proposed for AF prediction and detection for primary and secondary stroke prevention. However, clinical translation of these technological innovations to close the AF care gap has been scant. Herein, we sought to systematically examine studies, employing ML models to predict incident AF in a population without prior AF or to detect paroxysmal AF in stroke cohorts to identify key reasons for the lack of translation into the clinical workflow. We conclude with a set of recommendations to improve the clinical translatability of ML-based models for AF. (2) Methods: MEDLINE, Embase, Web of Science, Clinicaltrials.gov, and ICTRP databases were searched for relevant articles from the inception of the databases up to September 2022 to identify peer-reviewed articles in English that used ML methods to predict incident AF or detect AF after stroke and reported adequate performance metrics. The search yielded 2815 articles, of which 16 studies using ML models to predict incident AF and three studies focusing on ML models to detect AF post-stroke were included. (3) Conclusions: This study highlights that (1) many models utilized only a limited subset of variables available from patients' health records; (2) only 37% of models were externally validated, and stratified analysis was often lacking; (3) 0% of models and 53% of datasets were explicitly made available, limiting reproducibility and transparency; and (4) data pre-processing did not include bias mitigation and sufficient details, leading to potential selection bias. Low generalizability, high false alarm rate, and lack of interpretability were identified as additional factors to be addressed before ML models can be widely deployed in the clinical care setting. Given these limitations, our recommendations to improve the uptake of ML models for better AF outcomes include improving generalizability, reducing potential systemic biases, and investing in external validation studies whilst developing a transparent modeling pipeline to ensure reproducibility.

Percutaneous shunt vessel embolisation with Amplatzer vascular plugs II and IV in the treatment of dogs with splenophrenic shunts: four cases (2019-2022)

OBJECTIVES

To describe the treatment of four dogs with splenophrenic shunts using percutaneous shunting vessel embolisation with Amplatzer vascular plugs II and IV and provide information on their clinical outcomes.

MATERIALS AND METHODS

Dogs with splenophrenic shunts treated at a veterinary hospital from January 2019 to December 2022 were identified through a medical record search.

RESULTS

Six dogs with splenophrenic shunts were identified. Two dogs were excluded because they were treated with laparoscopic surgery. Four underwent percutaneous shunting vessel embolization with Amplatzer vascular plugs and were included in the case series. A sheath was placed in the left external jugular vein and a balloon catheter was advanced to the shunting vessel under fluoroscopy. Portal vein pressure was confirmed to be within an acceptable range during temporary balloon occlusion. Based on preoperative CT angiography and intraoperative contrast examination, Amplatzer vascular plugs II were selected for two dogs and IV were selected for two dogs. Under fluoroscopy, the plug was deployed into the shunting vessel, and angiography confirmed occlusion. In all cases, the increase in portal pressure after temporary occlusion was within the acceptable range, and complete occlusion of blood flow was possible with a single plug. There were no major procedure-related complications. No dogs developed post-ligation seizures or signs of portal hypertension. In addition, improvements in ammonia values were observed in all cases.

CLINICAL SIGNIFICANCE

Percutaneous splenophrenic shunt embolisation using Amplatzer vascular plugs II and IV is technically feasible in dogs, and assessed by intra-procedure angiography, a single plug completely obstructed blood flow in all dogs. Based on the literature search, this is the first report describing Amplatzer vascular plugs for the treatment of splenophrenic shunts.

Effects of Age, Sex, and Extracellular Matrix Integrity on Aortic Dilatation and Rupture in a Mouse Model of Marfan Syndrome

BACKGROUND

Transmural failure of the aorta is responsible for substantial morbidity and mortality; it occurs when mechanical stress exceeds strength. The aortic root and ascending aorta are susceptible to dissection and rupture in Marfan syndrome, a connective tissue disorder characterized by a progressive reduction in elastic fiber integrity. Whereas competent elastic fibers endow the aorta with compliance and resilience, cross-linked collagen fibers confer stiffness and strength. We hypothesized that postnatal reductions in matrix cross-linking increase aortopathy when turnover rates are high.

METHODS

We combined ex vivo biaxial mechanical testing with multimodality histological examinations to quantify expected age- and sex-dependent structural vulnerability of the ascending aorta in Fbn1C1041G/+ Marfan versus wild-type mice without and with 4-week exposures to β-aminopropionitrile, an inhibitor of lysyl oxidase-mediated cross-linking of newly synthesized elastic and collagen fibers.

RESULTS

We found a strong β-aminopropionitrile-associated sexual dimorphism in aortic dilatation in Marfan mice and aortic rupture in wild-type mice, with dilatation correlating with compromised elastic fiber integrity and rupture correlating with compromised collagen fibril organization. A lower incidence of rupture of β-aminopropionitrile-exposed Marfan aortas associated with increased lysyl oxidase, suggesting a compensatory remodeling of collagen that slows disease progression in the otherwise compromised Fbn1C1041G/+ aorta.

CONCLUSIONS

Collagen fiber structure and function in the Marfan aorta are augmented, in part, by increased lysyl oxidase in female and especially male mice, which improves structural integrity, particularly via fibrils in the adventitia. Preserving or promoting collagen cross-linking may represent a therapeutic target for an otherwise vulnerable aorta.

Biomechanical and transcriptional evidence that smooth muscle cell death drives an osteochondrogenic phenotype and severe proximal vascular disease in progeria

Hutchinson-Gilford Progeria Syndrome results in rapid aging and severe cardiovascular sequelae that accelerate near end-of-life. We found a progressive disease process in proximal elastic arteries that was less evident in distal muscular arteries. Changes in aortic structure and function were then associated with changes in transcriptomics assessed via both bulk and single cell RNA sequencing, which suggested a novel sequence of progressive aortic disease: adverse extracellular matrix remodeling followed by mechanical stress-induced smooth muscle cell death, leading a subset of remnant smooth muscle cells to an osteochondrogenic phenotype that results in an accumulation of proteoglycans that thickens the aortic wall and increases pulse wave velocity, with late calcification exacerbating these effects. Increased central artery pulse wave velocity is known to drive left ventricular diastolic dysfunction, the primary diagnosis in progeria children. It appears that mechanical stresses above ~ 80 kPa initiate this progressive aortic disease process, explaining why elastic lamellar structures that are organized early in development under low wall stresses appear to be nearly normal whereas other medial constituents worsen progressively in adulthood. Mitigating early mechanical stress-driven smooth muscle cell loss/phenotypic modulation promises to have important cardiovascular implications in progeria patients.

General public's understanding of rare diseases and their opinions on medical resource allocation in Japan: a cross-sectional study

BACKGROUND

Rare diseases (RDs) may impose a considerable financial burden on patients and their families. Public acceptance is essential to ensure sustainable public systems supporting RDs, especially in countries with universal healthcare coverage, such as Japan. This study aimed to explore the public's understanding of RDs and identify crucial factors associated with the public acceptance of prioritizing financial support for RDs in Japan.

METHODS

An online questionnaire was sent to 131,220 Japanese residents aged 20-69 years. The items included in the questionnaire were general interest in medical science and medical care, general knowledge regarding RDs and health care systems, opinions on the cost of medical care, opinions on the research and development of RDs and common diseases, and individual characteristics.

RESULTS

The responses of 11,019 respondents were analyzed. Several respondents agreed to partially cover the medication cost of adult and pediatric RDs (59.5% and 66.8%, respectively) with public funding. The major reasons for agreeing were the huge financial burden imposed on patients and their families, limited available treatment options, effects of RDs on the life planning of patients, and difficulties caused by RDs in the patient's social life. Furthermore, the respondents ranked RDs (56.0%) higher than common diseases (44.0%) for government funding for research and development. The reasons for supporting government-funded research and development for RDs included the lack of treatment options for numerous RDs (34.9%) and difficulty of studying RDs owing to the small number of researchers (25.9%). The chief reasons for supporting government-funded research and development for common diseases were the large number of affected patients (59.7%) and the possibility of more treatment options becoming available through the promotion of research and development (22.1%).

CONCLUSIONS

The general public considers burdens associated with daily living or finance more than the epidemiological characteristics of RD while making funding decisions, demonstrating that rarity was less prioritized. A gap appears to exist between the general public and RD experts regarding the understanding of the epidemiological characteristics of RD and its thresholds. This gap should be bridged to ensure that prioritization of financial support for RDs is accepted by the society.

Lonafarnib improves cardiovascular function and survival in a mouse model of Hutchinson-Gilford progeria syndrome

Clinical trials have demonstrated that lonafarnib, a farnesyltransferase inhibitor, extends the lifespan in patients afflicted by Hutchinson-Gilford progeria syndrome, a devastating condition that accelerates many characteristics of aging and results in premature death due to cardiovascular sequelae. The US Food and Drug Administration approved Zokinvy (lonafarnib) in November 2020 for treating these patients, yet a detailed examination of drug-associated effects on cardiovascular structure, properties, and function has remained wanting. In this paper, we report encouraging outcomes of daily post-weaning treatment with lonafarnib on the composition and biomechanical phenotype of elastic and muscular arteries as well as associated cardiac function in a well-accepted mouse model of progeria that exhibits severe perimorbid cardiovascular disease. Lonafarnib resulted in 100% survival of the treated progeria mice to the study end-point (time of 50% survival of untreated mice), with associated improvements in arterial structure and function working together to significantly reduce pulse wave velocity and improve left ventricular diastolic function. By contrast, neither treatment with the mTOR inhibitor rapamycin alone nor dual treatment with lonafarnib plus rapamycin improved outcomes over that achieved with lonafarnib monotherapy.

Smooth muscle αv integrins regulate vascular fibrosis via CD109 downregulation of TGF-β signalling

Aims

α_v integrins are implicated in fibrosis in a number of organs through their ability to activate TGF-β. However their role in vascular fibrosis and collagen accumulation is only partially understood. Here we have used α_v conditional knockout mice and cell lines to determine how α_v contributes to vascular smooth muscle cell (VSMC) function in vascular fibrosis and the role of TGF-β in that process.

Methods and results

Angiotensin II (Ang II) treatment causes upregulation of α_v and β₃ expression in the vessel wall, associated with increased collagen deposition. We found that deletion of α_v integrin subunit from VSMCs (α_v ^SMKO) protected mice against angiotensin II-induced collagen production and assembly. Transcriptomic analysis of the vessel wall in α_v ^SMKO mice and controls identified a significant reduction in expression of fibrosis and related genes in α_v ^SMKO mice. In contrast, α_v ^SMKO mice showed prolonged expression of CD109, which is known to affect TGF-β signalling. Using cultured mouse and human VSMCs, we showed that overexpression of CD109 phenocopied knockdown of α_v integrin, attenuating collagen expression, TGF-β activation, and Smad2/3 signalling in response to angiotensin II or TGF-β stimulation. CD109 and TGF-β receptor were internalized in early endosomes.

Conclusion

We identify a role for VSMC α_v integrin in vascular fibrosis and show that α_v acts in concert with CD109 to regulate TGF-β signalling.

Smooth Muscle Cell Death Drives an Osteochondrogenic Phenotype and Severe Proximal Vascular Disease in Progeria

Hutchinson-Gilford Progeria Syndrome results in rapid aging and severe cardiovascular sequelae that accelerate near end of life. We associate progressive deterioration of arterial structure and function with single cell transcriptional changes, which reveals a rapid disease process in proximal elastic arteries that largely spares distal muscular arteries. These data suggest a novel sequence of progressive vascular disease in progeria: initial extracellular matrix remodeling followed by mechanical stress-induced smooth muscle cell death in proximal arteries, leading a subset of remnant smooth muscle cells to an osteochondrogenic phenotypic modulation that results in an accumulation of proteoglycans that thickens the wall and increases pulse wave velocity, with late calcification exacerbating these effects. Increased pulse wave velocity drives left ventricular diastolic dysfunction, the primary diagnosis in progeria children. Mitigating smooth muscle cell loss / phenotypic modulation promises to have important cardiovascular implications in progeria patients.

High-power laser experiment forming a supercritical collisionless shock in a magnetized uniform plasma at rest

We present an experimental method to generate quasiperpendicular supercritical magnetized collisionless shocks. In our experiment, ambient nitrogen (N) plasma is at rest and well magnetized, and it has uniform mass density. The plasma is pushed by laser-driven ablation aluminum (Al) plasma. Streaked optical pyrometry and spatially resolved laser collective Thomson scattering clarify structures of plasma density and temperatures, which are compared with one-dimensional particle-in-cell simulations. It is indicated that just after the laser irradiation, the Al plasma is magnetized by a self-generated Biermann battery field, and the plasma slaps the incident N plasma. The compressed external field in the N plasma reflects N ions, leading to counterstreaming magnetized N flows. Namely, we identify the edge of the reflected N ions. Such interacting plasmas form a magnetized collisionless shock.

Microscopic Temperature Control Reveals Cooperative Regulation of Actin-Myosin Interaction by Drebrin E

Drebrin E is a regulatory protein of intracellular force produced by actomyosin complexes, that is, myosin molecular motors interacting with actin filaments. The expression level of drebrin E in nerve cells decreases as the animal grows, suggesting its pivotal but unclarified role in neuronal development. Here, by applying the microscopic heat pulse method to actomyosin motility assay, the regulatory mechanism is examined from the room temperature up to 37 °C without a thermal denaturing of proteins. We show that the inhibition of actomyosin motility by drebrin E is eliminated immediately and reversibly during heating and depends on drebrin E concentration. The direct observation of quantum dot-labeled drebrin E implies its stable binding to actin filaments during the heat-induced sliding. Our results suggest that drebrin E allosterically modifies the actin filament structure to regulate cooperatively the actomyosin activity at the maintained in vivo body temperature.

Reductive deiodination of 2,4,6-triiodophenol by Vallitalea sp. strain TIP-1 isolated from the marine sponge

An anaerobic microbial consortium capable of reductively dehalogenating 2,4,6-triiodophenol (2,4,6-TIP) was enriched from the marine sponge Hymeniacidon sinapium. The enrichment reductively deiodinated 100 μM of 2,4,6-TIP to 4-iodophenol (4-IP) and 2-iodophenol (2-IP) in the presence of sterile sponge tissue as the sole carbon source and electron donor. PCR-denaturing gradient gel electrophoresis and 16S rRNA gene sequence analysis revealed that bacteria closely related with Vallitalea guaymasensis and Oceanirhabdus sediminicola, both of which are members of the order Clostridiales, were predominant in the enrichment. When glucose was added to the enrichment as alternative carbon source, one of these bacteria grew predominantly, which was subsequently isolated as a pure culture. The strain, designated as TIP-1, showed 99.7% 16S rRNA gene sequence similarity with V. guaymasensis. In the presence of glucose, strain TIP-1 reductively deiodinated 2,4,6-TIP to 2-IP and 4-IP at a molar ratio of 3:1, during which 2,4-diiodophenol (2,4-DIP) and 2,6-diiodophenol (2,6-DIP) were observed as deiodinated intermediates. Glucose was required for 2,4,6-TIP deiodination, but 2,4,6-TIP was not essential for growth of strain TIP-1. The strain also deiodinated 2,4-DIP to 2-IP and 4-IP at a molar ratio of 1:1, and 2,6-DIP to 2-IP, but further deiodination of the monoiodophenols was not observed. These results suggest that strain TIP-1 removed both ortho- and para-substituted iodines equally. Such deiodinating bacteria could be applied to the mineralization or dehalogenation of triiodobenzene derivatives, which are widely used as X-ray contrast media.

Developmental origins of mechanical homeostasis in the aorta

BACKGROUND

Mechanical homeostasis promotes proper aortic structure and function. Pathological conditions may arise, in part, from compromised or lost homeostasis. There is thus a need to quantify the homeostatic state and when it emerges. Here we quantify changes in mechanical loading, geometry, structure, and function of the murine aorta from the late prenatal period into maturity.

RESULTS

Our data suggest that a homeostatic set-point is established by postnatal day P2 for the flow-induced shear stress experienced by endothelial cells; this value deviates from its set-point from P10 to P21 due to asynchronous changes in mechanical loading (flow, pressure) and geometry (radius, wall thickness), but is restored thereafter consistent with homeostasis. Smooth muscle contractility also decreases during this period of heightened matrix deposition but is also restored in maturity. The pressure-induced mechanical stress experienced by intramural cells initially remains low despite increasing blood pressure, and then increases while extracellular matrix accumulates.

CONCLUSIONS

These findings suggest that cell-level mechanical homeostasis emerges soon after birth to allow mechanosensitive cells to guide aortic development, with deposition of matrix after P2 increasingly stress shielding intramural cells. The associated tissue-level set-points that emerge for intramural stress can be used to assess and model the aorta that matures biomechanically by P56.

Mechanism of Elastic Properties of Biodegradable Poly[(R)-3-Hydroxybutyrate-co-4-hydroxybutyrate] Films Revealed by Synchrotron Radiation

Reversible elastic films of biobased and biodegradable poly[(R)-3-hydroxybutyrate-co-4-hydroxybutyrate] [P(3HB-co-4HB)] were prepared by uniaxial drawing procedures. Mechanical properties and highly ordered film structures were investigated by tensile testing and both static-state and in situ wide-angle X-ray diffraction and small-angle X-ray scattering with synchrotron radiation during stretching and relaxing. Despite the crystalline nature of the polymers, the elongation at break of these films was greater than 1500%. Reversible elasticity was achieved after the first 10 times of uniaxial stretching. X-ray measurement results indicated that on stretching, β-form molecular chains with a planar zigzag conformation were introduced from molecular chains with random coils in the amorphous regions between α-form lamellar crystals. Notably, the orientation of the α-form lamellar crystals increased after relaxation of the molecular chains with a planar zigzag conformation (β-form) between the lamellar crystals (α-form). Reversible elastic properties were regenerated by a planar zigzag conformation between the lamellar crystals, the extension of molecular chains in lamellar crystals by the rotation of molecular conformation, and changes in the degree of orientation of the lamellar crystals.

Differential biomechanical responses of elastic and muscular arteries to angiotensin II-induced hypertension

Elastic and muscular arteries are distinguished by their distinct microstructures, biomechanical properties, and smooth muscle cell contractile functions. They also exhibit differential remodeling in aging and hypertension. Although regional differences in biomechanical properties have been compared, few studies have quantified biaxial differences in response to hypertension. Here, we contrast passive and active changes in large elastic and medium- and small-sized muscular arteries in adult mice in response to chronic infusion of angiotensin over 14 days. We found a significant increase in wall thickness, both medial and adventitial, in the descending thoracic aorta that associated with trends of an increased collagen:elastin ratio. There was adventitial thickening in the small-sized mesenteric artery, but also significant changes in elastic lamellar structure and contractility. An increased contractile response to phenylephrine coupled with a reduced vasodilatory response to acetylcholine in the mesenteric artery suggested an increased contractile state in response to hypertension. Overall reductions in the calculated gradients in pulse wave velocity and elastin energy storage capability from elastic-to-muscular arteries suggested a possible transfer of excessive pulsatile energy into the small-sized muscular arteries resulting in significant functional consequences in response to hypertension.

Adventitial remodeling protects against aortic rupture following late smooth muscle-specific disruption of TGFβ signaling

Altered signaling through transforming growth factor-beta (TGFβ) increases the risk of aortic dissection in patients, which has been confirmed in mouse models. It is well known that altered TGFβ signaling affects matrix turnover, but there has not been a careful examination of associated changes in structure-function relations. In this paper, we present new findings on the rupture potential of the aortic wall following late postnatal smooth muscle cell (SMC)-specific disruption of type I and II TGFβ receptors in a mouse model with demonstrated dissection susceptibility. Using a combination of custom computer-controlled biaxial tests and quantitative histology and immunohistochemistry, we found that loss of TGFβ signaling in SMCs compromises medial properties but induces compensatory changes in the adventitia that preserve wall strength above that which is needed to resist in vivo values of wall stress. These findings emphasize the different structural defects that lead to aortic dissection and rupture - compromised medial integrity and insufficient adventitial strength, respectively. Relative differences in these two defects, in an individual subject at a particular time, likely reflects the considerable phenotypic diversity that is common in clinical presentations of thoracic aortic dissection and rupture. There is, therefore, a need to move beyond examinations of bulk biological assays and wall properties to cell- and layer-specific studies that delineate pathologic and compensatory changes in wall biology and composition, and thus the structural integrity of the aortic wall that can dictate differences between life and death.

Characterizing genetic variants for DAG and IP3 signalling pathways in severe cases of coronary spastic angina

Background

We previously reported that the activity of phospholipase C (PLC), a key molecule for intracellular calcium signaling, was enhanced in patients with coronary spastic angina (CSA). Furthermore, we found PLC-δ1 864 G to A mutation in about 10% of the male CSA patients. However, comprehensive understanding of genetic role in the pathogenesis of CSA remains to be elucidated.

Purpose

We tested the hypothesis that variants in the genes responsible for contraction signaling, especially a Ca2+-dependent mechanism, plays an important role in the pathogenesis of CSA.

Methods and results

Exome sequencing was performed to genotype comprehensively CSA cohort, enabling investigation of 258 gene network for diacylglycerol (DAG) and inositol trisphosphate (IP3) signallings, which are responsible for contraction signaling in the vascular smooth muscle cell (VSMC) by a Ca2+-dependent mechanism.

The study population included 30 Japanese patients with severe cases of CSA (18 men and 12 women with a mean age of 62.2±10.1 years). In 23 patients, ST segment elevation was recorded on the electrocardiogram during a spontaneous attack. In other 3 patients, ventricular fibrillation occurred following CSA attacks. The rests were diagnosed by ECG changes and elevated cardiac enzymes following CSA attacks. Genetic information from these CSA patients were compared with those from 914 healthy controls.

Frequencies of 17 common, functional polymorphisms of DAG and IP3 signallings were statistically similar to those of healthy controls. By high-quality (Call Quality ≥20, Read Depth ≥10), and predicted-deleterious (CADD score ≥20) filterings, the number of the candidate genes were narrowed from 234,445 to 17,738, and by selecting genes for DAG and IP3 signallings, further narrowed to 208 genes. Compared with 914 healthy controls, DAG and IP3 signalling genes revealed 26 variants in 15 genes in CSA cases, and by further filtering for rare (914 healthy control frequency <1%), 21 variants in 12 genes were found. They shared variants in G protein subunit alpha q (GNAQ), phospholipase C beta 3 (PLCB3), inositol 1,4,5-trisphosphate receptor type 3 (ITPR3), glutamate ionotropic receptor NMDA type subunit 2D (GRIN2D) in ≥5 cases. By filtering for high-quality, predicted-deleterious, and rare, genetic variants related with DAG and IP3 signalling were more found in severe CSA patients compared with healthy controls (CSA 4.33/person vs healthy controls 2.60 /person).

Conclusions

These findings indicate genetic heterogeneity in CSA susceptibility and a likely polygenic basis, giving a cumulative effect on DAG and IP3 signalling pathways in a subset of individual CSA patients. Study of larger cohorts is warranted to define genetic risk factors for CSA.

Funding Acknowledgement

Type of funding source: None

Estimation of the effects of inset heights and slit configurations in an acetabular cup on the pull-out behavior of an artificial hip joint with a structure for preventing dislocation using finite element analysis

Joint dislocation is a critical problem of total hip replacement. We have newly proposed an artificial hip joint with a structure that prevents dislocation. The proposed joint has a simple form with a femoral head partially covered with an acetabular cup. In the present study, the effects of inset heights and slit configurations of the cup on the pull-out forces of the joint were evaluated using finite element analysis. Joint models with different inset heights and those with or without a slit in the cup were used for the analyses to estimate the pull-out forces of the joint. In the case without the slit, the maximum pull-out force of the joint with 1.0 and 1.5 mm of the inset height was approximately 12 and 40 N, respectively. In the case of 1.0-mm inset height, the maximum force of the joint with and without the slit was approximately 9 and 12 N, respectively. These results reveal that the maximum force is markedly changed by the inset height and is moderately affected by the slit. Thus, we can gain insights into a strategy to optimally design an artificial joint in which dislocation does not occur easily. Graphical abstract.

Single-cell temperature mapping with fluorescent thermometer nanosheets

Recent studies using intracellular thermometers have shown that the temperature inside cultured single cells varies heterogeneously on the order of 1°C. However, the reliability of intracellular thermometry has been challenged both experimentally and theoretically because it is, in principle, exceedingly difficult to exclude the effects of nonthermal factors on the thermometers. To accurately measure cellular temperatures from outside of cells, we developed novel thermometry with fluorescent thermometer nanosheets, allowing for noninvasive global temperature mapping of cultured single cells. Various types of cells, i.e., HeLa/HEK293 cells, brown adipocytes, cardiomyocytes, and neurons, were cultured on nanosheets containing the temperature-sensitive fluorescent dye europium (III) thenoyltrifluoroacetonate trihydrate. First, we found that the difference in temperature on the nanosheet between nonexcitable HeLa/HEK293 cells and the culture medium was less than 0.2°C. The expression of mutated type 1 ryanodine receptors (R164C or Y523S) in HEK293 cells that cause Ca²⁺ leak from the endoplasmic reticulum did not change the cellular temperature greater than 0.1°C. Yet intracellular thermometry detected an increase in temperature of greater than ∼2°C at the endoplasmic reticulum in HeLa cells upon ionomycin-induced intracellular Ca²⁺ burst; global cellular temperature remained nearly constant within ±0.2°C. When rat neonatal cardiomyocytes or brown adipocytes were stimulated by a mitochondrial uncoupling reagent, the temperature was nearly unchanged within ±0.1°C. In cardiomyocytes, the temperature was stable within ±0.01°C during contractions when electrically stimulated at 2 Hz. Similarly, when rat hippocampal neurons were electrically stimulated at 0.25 Hz, the temperature was stable within ±0.03°C. The present findings with nonexcitable and excitable cells demonstrate that heat produced upon activation in single cells does not uniformly increase cellular temperature on a global basis, but merely forms a local temperature gradient on the order of ∼1°C just proximal to a heat source, such as the endoplasmic/sarcoplasmic reticulum ATPase.

Paradoxical aortic stiffening and subsequent cardiac dysfunction in Hutchinson-Gilford progeria syndrome

Hutchinson-Gilford progeria syndrome (HGPS) is an ultra-rare disorder with devastating sequelae resulting in early death, presently thought to stem primarily from cardiovascular events. We analyse novel longitudinal cardiovascular data from a mouse model of HGPS (Lmna^G609G/G609G) using allometric scaling, biomechanical phenotyping, and advanced computational modelling and show that late-stage diastolic dysfunction, with preserved systolic function, emerges with an increase in the pulse wave velocity and an associated loss of aortic function, independent of sex. Specifically, there is a dramatic late-stage loss of smooth muscle function and cells and an excessive accumulation of proteoglycans along the aorta, which result in a loss of biomechanical function (contractility and elastic energy storage) and a marked structural stiffening despite a distinctly low intrinsic material stiffness that is consistent with the lack of functional lamin A. Importantly, the vascular function appears to arise normally from the low-stress environment of development, only to succumb progressively to pressure-related effects of the lamin A mutation and become extreme in the peri-morbid period. Because the dramatic life-threatening aortic phenotype manifests during the last third of life there may be a therapeutic window in maturity that could alleviate concerns with therapies administered during early periods of arterial development.

Mechanical feedback cooling assisted by optical cavity cooling of the thermal vibration of a microcantilever

This study describes a new two-step process to cool the thermal vibration of microcantilevers. The process combines active mechanical feedback cooling and optical cavity cooling. A micro-Fabry–Perot interferometer, built in-house, is set atop a microcantilever to measure the vibration amplitude, the high optical power density of which induces cavity cooling in the optical cavity. Using a two-step cooling procedure, the equivalent temperature of the thermal vibration of a microcantilever is lowered from room temperature to the theoretical cooling limit of 0.063 K, a much lower temperature than that achieved via simple cavity cooling (18 K), and then by mechanical feedback cooling (0.135 K) obtained for the same type of microcantilevers in previous studies. This experimental demonstration showcases a new type of cooling process of the amplitude of thermal vibration for micro-mechanical resonators to a lower temperature and does not need additional cooling using a conventional cryogenic refrigerator.

P838Is multi-biomarker combination approach comparable to the GRACE risk score for short-term mortality prediction in acute myocardial infarction cases?

Introduction

The Global Registry of Acute Coronary Events (GRACE) score is said to be a superior predictor of mortality in acute myocardial infarction (AMI) patients, and same applies to biochemical parameters as N-terminal pro-B-type natriuretic peptide (N-BNP), Troponin-T (TnT) and high-sensitivity C- reactive protein (hs-CRP) levels.

Purpose

We validated that whether each or combination of biochemical parameters are comparable to GRACE score or not for mortality prediction in AMI patients.

Method

We investigated about clinical background including The GRACE score, above parameters and in-hospital mortality in 754 AMI patients (mean age 66±13y/o, 609 ST-elevated AMI cases) received emergency percutaneous coronary intervention (PCI) successfully during 8 years in a single center retrospectively. Combination of biochemical parameters are derived from N-BNP, TnT and hs-CRP by logistic regression analyses. We compared The GRACE score with each or combination of biochemical parameters between survival (SG) and non-survival group (nSG) on receiver operating characteristic (ROC) analysis.

Result

In-hospital mortality was 6.8%. The GRACE score (106±33 versus 161±32; p<0.005) and N-BNP level (2458±7058 versus 8880±11331pg/ml; p<0.005) were significantly lower in SG than nSG. Area under the ROC curve about in-hospital mortality of The GRACE score were higher (0.868) than N-BNP (0.787; p=0.007), TnT (0.613; p<0.005), hs-CRP levels (0.614; p<0.005) and multi-biomarker combination (0.742; p=0.016) as Figure 1.

Area under the curve of the composite with the GRACE score and multi-biomarker is not increased compared with the GRACE score alone (0.868 versus 0.865; p=n.s.).

Figure 1

Conclusion

The GRACE score is a superior predictor about in-hospital mortality than each or combination of biochemical parameters in AMI patients. Multi-biomarker combination dose not refine the accuracy of the GRACE score.

P1624Blockade of protease activated receptor-1 signaling attenuates cardiac hypertrophy and fibrosis in renin-overexpressing hypertensive mice

Introduction

Recent evidences have demonstrated that coagulation pathway is involved in cardiovascular remodeling induced by renin-angiotensin system (RAS), which finally leads to heart failure. Protease activated receptor-1 (PAR-1) is widely expressed in the vasculature and the heart, and plays important roles in pro-inflammatory process in the cardiovascular system. Recently, we demonstrated that the activity of factor Xa (FXa), which functions not only as a coagulation factor but as an agonist for PAR-1, was enhanced in renin-overexpressing hypertensive mice (Ren-Tg).

Purpose

The purpose of this study was to investigate whether inhibition of PAR-1 signaling has protective effects on the progression of heart failure induced by chronic RAS activation in Ren-Tg.

Methods and results

We treated 12–16 weeks-old male wild type mice (WT) and Ren-Tg with continuous subcutaneous infusion of PAR-1 antagonist SCH79797 (25mg/kg/day) or vehicle for 4 weeks. After treatment period, left ventricular (LV) wall thickness calculated as interventricular septum plus posterior wall thickness measured by echocardiography was greater in Ren-Tg than in WT (0.25±0.003 versus 0.18±0.002 mm), and SCH79797 attenuated the increase to 0.22±0.01 mm in Ren-Tg (both p<0.05, respectively). The ratio of heart weight to body weight was greater in Ren-Tg than in WT (6.1±0.4 versus 4.6±0.7 mg/g), and SCH79797 attenuated the increase to 5.2±0.1 mg/g (both p<0.05). The area of cardiac fibrosis evaluated by Masson-trichrome staining was greater in Ren-Tg than in WT (2.6±0.2 versus 1.4±0.3%), and SCH79797 attenuated it to 1.6±0.3% in Ren-Tg (both p<0.05). Cardiac mRNA expressions of tumor necrosis factor-α, transforming growth factor-β1, and β-myosin heavy chain were all greater in Ren-Tg than in WT, and SCH79797 attenuated the increases in Ren-Tg (all p<0.05).

Conclusions

Inhibition of PAR-1 signaling attenuates cardiac hypertrophy and fibrosis in Ren-Tg via inhibition of inflammatory cytokines production. These results support the involvement of PAR signaling in the development of heart failure induced by RAS, and may provide novel therapeutic insights for the treatment of hypertensive heart failure.

Denaturation of Lysozyme with Visible-light-responsive Photocatalysts of Ground Rhodium-doped and Ground Rhodium-antimony-co-doped Strontium Titanate

Protein denaturants play an important role in medical and biological research, and development of new denaturants is widely explored to study aging and various diseases. In this research, we treated lysozyme, a model protein, with photocatalysts of ground Rh-doped SrTiO₃ (g-STO:Rh) and ground Rh-Sb-co-doped SrTiO₃ (g-STO:Rh/Sb) under visible light irradiation to explore the potential of those photocatalysts as denaturants. SDS-PAGE showed that photocatalysis with g-STO:Rh induced the fragmentation of lysozyme into unidentifiable decomposition products. BCA and Bradford protein assays indicated that the peptide bonds and basic, aromatic and N-terminal amino acid residues in lysozyme were denaturated by g-STO:Rh photocatalysis. The denaturation of those amino acids, as quantified by the decreased solubility of lysozyme, was estimated to be more severe by Bradford protein assay than by BCA protein assay. Circular dichroism (CD) spectra of lysozyme revealed that the secondary structure was denatured by g-STO:Rh photocatalysis, indicating that g-STO:Rh photocatalysis is especially effective against the amino acid residues that form the secondary structure via hydrogen bonds. Furthermore, the lytic activity of lysozyme was reduced by g-STO:Rh photocatalysis, owing to denaturation of the enzyme. The visible-light-responsive photocatalyst of g-STO:Rh/Sb accelerates the oxidation reaction and has stronger oxidizing power than g-STO:Rh. Lysozyme was denatured more quickly by g-STO:Rh/Sb photocatalysis than by g-STO:Rh according to analysis by SDS-PAGE, CD spectroscopy, BCA and Bradford protein assays, and lytic activity. These results suggest that higher photocatalytic activity induces more significant denaturation of lysozyme, implying that the main factor of photocatalytic denaturation of lysozyme is oxidation. It should be noted that, as far as we know, this is the first report for denaturation of protein using visible-light-responsive photocatalyst.

The Role of Oral Kinesthesia in the Determination of the Swallowing Threshold

The interdental dimension discrimination (IDD) ability and the swallowing threshold were evaluated at the sitting and supine positions. The difference in the magnitude of mis-estimation of IDD and that in the swallowing threshold between the two positions was significantly correlated. These results indicate some influence of the IDD in the determination of the swallowing threshold.

Temporomandibular Joint Movement

Ten temporomandibular joints (TMJs) of 5 healthy volunteers and 19 TMJs of internal derangements in 16 patients with splint therapy were examined with MR imaging. T1-weighted images were obtained only in the closed mouth position, and gradient recalled acquisition in steady state (GRASS) images were obtained in active opening and closing phases, allowing a pseudodynamic display of TMJ movement. All patients received protrusive splint treatment. The usefulness of MR imaging to assess the efficacy of splint therapy was evaluated. Corrected disk position with the splint in place was clearly demonstrated in 9 TMJs, corresponding with elimination of reciprocal clicking. Ten other TMJs of anterior disk displacement without reduction showed uncorrected disk position by the splint. This information could confirm the therapeutic efficacy, or suggest other treatment alternatives. GRASS MR imaging can provide accurate and physiologic information about disk function in initial and follow-up assessment of protrusive splint therapy.

High expression of Fatty Acid-Binding Protein 5 promotes cell growth and metastatic potential of colorectal cancer cells

Fatty acid‐binding proteins (FABPs) are responsible for binding and storing hydrophobic ligands such as long‐chain fatty acids, and for transporting these ligands to the appropriate compartments within the cell. The present study demonstrates that the FABP5 gene is upregulated in colorectal cancer cells compared to normal colon cells in a manner that correlates with disease stage and that FABP5 significantly promotes colorectal cancer cell growth and metastatic potential. Thus, FABP5 might be a promising prognostic or therapeutic biomarker candidate in human colorectal cancer.

Triggering of high-speed neurite outgrowth using an optical microheater

Optical microheating is a powerful non-invasive method for manipulating biological functions such as gene expression, muscle contraction, and cell excitation. Here, we demonstrate its potential usage for regulating neurite outgrowth. We found that optical microheating with a water-absorbable 1,455-nm laser beam triggers directional and explosive neurite outgrowth and branching in rat hippocampal neurons. The focused laser beam under a microscope rapidly increases the local temperature from 36 °C to 41 °C (stabilized within 2 s), resulting in the elongation of neurites by more than 10 μm within 1 min. This high-speed, persistent elongation of neurites was suppressed by inhibitors of both microtubule and actin polymerization, indicating that the thermosensitive dynamics of these cytoskeletons play crucial roles in this heat-induced neurite outgrowth. Furthermore, we showed that microheating induced the regrowth of injured neurites and the interconnection of neurites. These results demonstrate the efficacy of optical microheating methods for the construction of arbitrary neural networks.

Glial fibrillar acidic protein in the cerebrospinal fluid of Alzheimer's disease, dementia with Lewy bodies, and frontotemporal lobar degeneration

Biomarkers in the cerebrospinal fluid (CSF) are currently regarded as indispensable indicators for accurate differential diagnosis of neurodegenerative disorders. Although high levels of astrocyte-secreted glial fibrillar acidic protein (GFAP) in the CSF of patients with Alzheimer's disease (AD) have been reported, the levels of GFAP in the CSF have not been fully investigated in other neurological disorders that cause dementia, such as dementia with Lewy bodies (DLB) and frontotemporal lobar degeneration (FTLD). In this study, we determined the levels of GFAP in the CSF of healthy control subjects and AD, DLB, and FTLD patients to address two questions: (i) Do the levels of GFAP differ among these disorders? and (ii) Can GFAP be used as a biomarker for the differential diagnosis of these neurodegenerative disorders? The levels of GFAP in AD, DLB, and FTLD patients were significantly higher than those in the healthy control subjects. Although the levels of GFAP were not significantly different between AD and DLB patients, a higher level of GFAP was observed in FTLD patients than in AD and DLB patients. It is concluded that representative neurological disorders causing dementia were associated with higher levels of GFAP in the CSF. We propose the following mechanism concerning the amount of glial fibrillar acidic protein (GFAP) in the cerebrospinal fluid (CSF) in Alzheimer's disease (AD), dementia with Lewy bodies (DLB), and frontotemporal lobar degeneration (FTLD). The increase in the release of GFAP into CSF is considered to reflect the sum of degeneration of astrocytes and astrocytosis. The sum of degeneration and astrocytosis or the GFAP release could be in the order of FTLD > DLB > AD > normal condition.