The apelin­apelin receptor signaling pathway in fibroblasts is involved in tumor growth via p53 expression of cancer cells.

Cancer­associated fibroblasts (CAFs) are pivotal in tumor progression. TP53­deficiency in cancer cells is associated with robust stromal activation. The apelin­apelin receptor (APJ) system has been implicated in suppressing fibroblast­to­myofibroblast transition in non­neoplastic organ fibrosis. The present study aimed to elucidate the oncogenic role of the apelin­APJ system in tumor fibroblasts. APJ expression and the effect of APJ suppression in fibroblasts were investigated for p53 status in cancer cells using human cell lines (TP53­wild colon cancer, HCT116, and Caco­2; TP53­mutant colon cancer, SW480, and DLD­1; and colon fibroblasts, CCD­18Co), resected human tissue samples of colorectal cancers, and immune­deficient nude mouse xenograft models. The role of exosomes collected by ultracentrifugation were also analyzed as mediators of p53 expression in cancer cells and APJ expression in fibroblasts. APJ expression in fibroblasts co­cultured with p53­suppressed colon cancer cells (HCT116sh p53 cells) was significantly lower than in control colon cancer cells (HCT116sh control cells). APJ­suppressed fibroblasts treated with an antagonist or small interfering RNA showed myofibroblast­like properties, including increased proliferation and migratory abilities, via accelerated phosphorylation of Sma­ and Mad­related protein 2/3 (Smad2/3). In addition, xenografts of HCT116 cells with APJ­suppressed fibroblasts showed accelerated tumor growth. By contrast, apelin suppressed the upregulation of phosphorylated Smad2/3 in fibroblasts. MicroRNA 5703 enriched in exosomes derived from HCT116sh p53 cells inhibited APJ expression, and inhibition of miR­5703 diminished APJ suppression in fibroblasts caused by cancer cells. APJ suppression from a specific microRNA in cancer cell­derived exosomes induced CAF­like properties in fibroblasts. Thus, the APJ system in fibroblasts in the tumor microenvironment may be a promising therapeutic target.

Afterimage duration depends on how deeply invisible stimuli were suppressed.

Quantifying visual responses to stimuli that are outside of awareness is a critical task for the study of visual consciousness. The current study psychophysically investigated whether afterimages reflect visual responses to stimuli that are not consciously visible throughout adaptation due to interocular suppression. A Gabor adaptor was presented to one eye of the observer, and a counterphase-flickering Gabor suppressor was presented to the other eye, thereby rendering the adaptor invisible during adaptation. To manipulate the depth of the suppression of the invisible adaptor, we varied the orientation difference between the adaptor and suppressor. We found that, even though the adaptor was not visible during adaptation, the afterimage duration varied depending on the orientation selectivity of interocular suppression. The duration was the shortest when the orientations of the adaptor and suppressor were identical and lengthened when the orientation differences increased. This finding could not be explained by confounding factors such as potential changes in contrast sensitivity that were caused by the suppressor. Our findings suggest that the magnitude of visual responses to stimuli suppressed below the threshold of awareness can be measured using the afterimage duration. Afterimages could be an effective tool for quantifying visual responses, irrespective of observers' conscious awareness of a presented stimulus.

Two distinct types of color spreading induced by different luminance and color conditions in static flank transparency displays.

Flank transparency refers to illusory, phenomenally transparent color spreading induced when narrow colored flanks are added to line segments located within a virtual region. We investigated whether the luminance conditions that induced flank transparency were consistent with predictions based on luminance-contrast-based boundary interactions and the episcotister model for perceptual transparency. Examination of the requirements for the boundary interaction and perceptual transparency revealed that similar luminance conditions are necessary for both; that is, the flank luminance needs to be intermediate between the line and background luminances. We used green and achromatic flanks and systematically varied the luminance of the flanks, line segments, and background. We then asked the observers to rate the subjective certainty of color spreading using a five-point scale. The results showed that the perception of color spreading depended on color as well as luminance conditions. Generally, color spreading was convincing and phenomenally transparent when luminance conditions were consistent with the requirements for boundary interaction and perceptual transparency. In addition, color conditions worked in a facilitatory and inhibitory manner. Moreover, the results revealed that another convincing color spreading could be observed when the flank luminance was lower than the line or background luminance, that is, when the luminance condition for perceptual transparency was not satisfied. The observers' verbal reports indicated that phenomenal transparency was not evident in this color spreading. Overall, the present findings demonstrate that typical transparent color spreading is not the only one observed in the flank transparency display. Different color and luminance conditions can modulate the phenomenal appearance of color spreading, resulting in distinct types of color spreading.

Molecular mechanism of the wake-promoting agent TAK-925.

The OX2 orexin receptor (OX2R) is a highly expressed G protein-coupled receptor (GPCR) in the brain that regulates wakefulness and circadian rhythms in humans. Antagonism of OX2R is a proven therapeutic strategy for insomnia drugs, and agonism of OX2R is a potentially powerful approach for narcolepsy type 1, which is characterized by the death of orexinergic neurons. Until recently, agonism of OX2R had been considered 'undruggable.' We harness cryo-electron microscopy of OX2R-G protein complexes to determine how the first clinically tested OX2R agonist TAK-925 can activate OX2R in a highly selective manner. Two structures of TAK-925-bound OX2R with either a Gq mimetic or Gi reveal that TAK-925 binds at the same site occupied by antagonists, yet interacts with the transmembrane helices to trigger activating microswitches. Our structural and mutagenesis data show that TAK-925's selectivity is mediated by subtle differences between OX1 and OX2 receptor subtypes at the orthosteric pocket. Finally, differences in the polarity of interactions at the G protein binding interfaces help to rationalize OX2R's coupling selectivity for Gq signaling. The mechanisms of TAK-925's binding, activation, and selectivity presented herein will aid in understanding the efficacy of small molecule OX2R agonists for narcolepsy and other circadian disorders.

Early development of the pulmonary vascular system: An anatomical and histochemical reinvestigation of the pulmonary venous return development in mice.

Pulmonary venous return development establishes the fetal circulation and is critical for the formation of pulmonary circulation independent of systemic circulation at birth. Anomalous returns lead to inappropriate drainage of blood flow, sometimes resulting in neonatal cyanosis and cardiac failure. While many classical studies have discussed the anatomical features of the pulmonary venous system development, the cellular dynamics of the endothelia based on the molecular marker expression remain unknown. In the present study, we examined the expression of several endothelial markers during early pulmonary vascular system development of murine embryos. We show that Endomucin and CD31 are expressed early in endothelial cells of the splanchnic plexus, which is the precursor of the pulmonary vascular system. Three-dimensional analyses of the expression patterns revealed the spatiotemporal modification of the venous returns to systemic venous systems or sinoatrial canal during the formation of the pulmonary plexus. We herein report the results of spatiotemporal analyses of the early pulmonary venous system development with histochemistry as well as a delineation of the anatomical features of the tentative drainage pathways.

Eye swapping temporally modulates potency of continuous flash suppression.

Continuous flash suppression (CFS) refers to a technique to render a monocular stimulus invisible by presenting a dynamic series of high-contrast patterns (such as Mondrian patterns) to the other eye. Despite its popularity as a tool to suppress stimulus from awareness, the suppression mechanisms underlying CFS remain not well understood. To further elucidate the suppression mechanisms, this study investigated the effects of eye swapping on CFS suppression by manipulating the eye of presentation of the suppressor and the target. Results showed that eye swapping of the suppressor and the target significantly reduced the strength of CFS suppression when swapping frequency was higher (3.5 Hz). However, strong suppression persisted at lower swapping frequency (1.2 Hz). Investigation of the time course of suppression revealed that suppression was weaker just after eye swapping but that it quickly regained strength over the monocular presentation period of the suppressor. However, this buildup seemed to not be fast enough to closely follow eye swapping at higher frequency. These findings can be better understood by the contribution of monocular processes to CFS suppression. They imply that interocular suppression caused by competition between monocular processes can mediate phenomenal suppression over multiple eye swaps when swapping frequency is low. The significance of the findings is discussed in relation to binocular rivalry and binocular switch suppression.

Task-driven and flexible mean judgment for heterogeneous luminance ensembles.

Spatial averaging of luminances over a variegated region has been assumed in visual processes such as light adaptation, texture segmentation, and lightness scaling. Despite the importance of these processes, how mean brightness can be computed remains largely unknown. We investigated how accurately and precisely mean brightness can be compared for two briefly presented heterogeneous luminance arrays composed of different numbers of disks. The results demonstrated that mean brightness judgments can be made in a task-dependent and flexible fashion. Mean brightness judgments measured via the point of subjective equality (PSE) exhibited a consistent bias, suggesting that observers relied strongly on a subset of the disks (e.g., the highest- or lowest-luminance disks) in making their judgments. Moreover, the direction of the bias flexibly changed with the task requirements, even when the stimuli were completely the same. When asked to choose the brighter array, observers relied more on the highest-luminance disks. However, when asked to choose the darker array, observers relied more on the lowest-luminance disks. In contrast, when the task was the same, observers' judgments were almost immune to substantial changes in apparent contrast caused by changing the background luminance. Despite the bias in PSE, the mean brightness judgments were precise. The just-noticeable differences measured for multiple disks were similar to or even smaller than those for single disks, which suggested a benefit of averaging. These findings implicated flexible weighted averaging; that is, mean brightness can be judged efficiently by flexibly relying more on a few items that are relevant to the task.

Pyogenic granuloma originating in the pulmonary artery.

We herein report an unreported case of pyogenic granuloma that originated in the pulmonary artery. A 38-year-old man was urgently hospitalized with dyspnea and back pain. He had been on hemodialysis for 2 years due to chronic renal failure. We performed contrast-enhanced computed tomography and detected a mass occluding the left main pulmonary artery. The maximum standardized uptake value (SUVmax) of 18F-fluorodeoxy glucose (FDG) in the mass was 4.1. We made a tentative diagnosis of pulmonary artery tumor, and planned an operation. We performed median sternotomy and left anterolateral thoracotomy. As the tumor had not reached the bottom of the left pulmonary artery, we first performed left upper lobectomy. We then performed resection of the pulmonary artery tumor under cardiopulmonary bypass and reconstructed the pulmonary artery with self-pericardium. The pathological diagnosis was pyogenic granuloma. To our knowledge, pyogenic granuloma originating in the pulmonary artery has never been reported before.

Long-Term Zinc Supplementation Improves Liver Function and Decreases the Risk of Developing Hepatocellular Carcinoma.

Zinc plays a pivotal role in various zinc enzymes, which are crucial in the maintenance of liver function. Patients with chronic liver diseases (CLDs) usually have lower concentrations of zinc, which decrease further as liver fibrosis progresses. Whether long-term zinc supplementation improves liver function and reduces the risk of hepatocellular carcinoma (HCC) development remains unknown. Two hundred and sixty-seven patients with CLDs who received a zinc preparation (Zn-group; 196 patients), or who did not receive zinc (no Zn-treatment group; 71 patients), were retrospectively analyzed in this study. The Zn-group was divided into 4 groups according to their serum Zn concentrations at 6 months after the start of Zn treatment. Liver function significantly deteriorated in the no Zn-treatment group, while no notable change was observed in the Zn-group. The cumulative incidence rates of events and HCC at 3 years were observed to be lower in the Zn-group (9.5%, 7.6%) than in the no Zn-treatment group (24.9%, 19.2%) (p < 0.001). According to serum Zn concentrations, the cumulative incidence rates of events and HCC were significantly decreased in patients with Zn concentrations ≥ 70 µg/dL (p < 0.001). Zinc supplementation appears to be effective at maintaining liver function and suppressing events and HCC development, especially among patients whose Zn concentration is greater than 70 µg/dL.

[Right Atrial Approach for the Surgical Repair of Delayed Ventricular Septal Rupture].

Ventricular septal rupture(VSR) after acute myocardial infarction(AMI) is a rare and serious complication that is associated with extremely high mortality. Delayed VSR is particularly uncommon and is difficult to diagnose and treat. A 68-year-old man presented with dyspnea on effort. Coronary angiography revealed subtotal occlusion of the right coronary artery(RCA) with collateral circulation to the chronically and totally occluded left anterior descending artery (LAD). Elective stenting of the RCA was successfully performed for a recent MI of the RCA, while percutaneous coronary intervention(PCI) in the LAD ended in failure. At 21 days after the 1st PCI, the patient developed acute heart failure with new pansystolic murmur. Cardiac catheterization showed a left to right ventricular shunting without new coronary artery lesions. Fortunately, the hemodynamic status was stable, and we could perform elective surgical repair by right atrial approach. Simultaneously, a left internal thoracic artery bypass to the LAD was performed. The postoperative course was uneventful. The patient is currently doing well at 5 years after the operation.

Averaging colors of multicolor mosaics.

The present study investigated how color information was summarized in multicolor mosaics. The mosaics were composed of small elements of 17 colors that roughly belonged to a single color category. We manipulated the degree of color variation around the mean by varying the proportion of different color elements. Observers matched the mean color of the multicolor mosaic by adjusting the color of a spatially uniform matching stimulus. Results showed that when the color variation was large, the matched color deviated from the colorimetric mean toward the most-saturated color, although the hue of the matched color was almost the same as that of the colorimetric mean. These findings together suggested differential processing of hue and saturation. The deviation of the matched color decreased, but did not disappear, when the color variation was reduced. The analysis of color metric underlying color averaging revealed differential color scaling in nearly orthogonal blue-orange and green-purple directions, implying that the visual system does not solely rely on linear cone-opponent codes when summarizing color signals. The deviation itself was consistently found regardless of different color metrics tested. The robustness of the deviation indicated an inherent bias of mean color judgments favoring highly saturated colors.

Live imaging of primary ocular vasculature formation in zebrafish.

Ocular vasculature consists of the central retinal and ciliary vascular systems, which are essential to maintaining visual function. Many researchers have attempted to determine their origins and development; however, the detailed, stepwise process of ocular vasculature formation has not been established. In zebrafish, two angioblast clusters, the rostral and midbrain organizing centers, form almost all of the cranial vasculature, including the ocular vasculature, and these are from where the cerebral arterial and venous angioblast clusters, respectively, differentiate. In this study, we first determined the anatomical architecture of the primary ocular vasculature and then followed its path from the two cerebral angioblast clusters using a time-lapse analysis of living Tg(flk1:EGFP)k7 zebrafish embryos, in which the endothelial cells specifically expressed enhanced green fluorescent protein. We succeeded in capturing images of the primary ocular vasculature formation and were able to determine the origin of each ocular vessel. In zebrafish, the hyaloid and ciliary arterial systems first organized independently, and then anastomosed via the inner optic circle on the surface of the lens by the lateral transfer of the optic vein. Finally, the choroidal vascular plexus formed around the eyeball to complete the primary ocular vasculature formation. To our knowledge, this study is the first to report successful capture of circular integration of the optic artery and vein, lateral transfer of the optic vein to integrate the hyaloidal and superficial ocular vasculatures, and formation of the choroidal vascular plexus. Furthermore, this new morphological information enables us to assess the entire process of the primary ocular vasculature formation, which will be useful for its precise understanding.

Rapid proportion comparison with spatial arrays of frequently used meaningful visual symbols.

It has been shown that when two arrays of Arabic numerals were briefly presented, observers could accurately indicate which array contained the larger number of a target numeral. This study investigated whether this rapid proportion comparison can be extended to other meaningful symbols that share some of notable properties of Arabic numerals. We tested mainly several Japanese Kanji letters, each of which represents a meaning and can work as a word. Using physically identical stimulus sets that could be interpreted as different types of letters, Experiment 1 first confirmed the rapid proportion comparison with Arabic numerals for Japanese participants. Experiment 2 showed that the rapid proportion comparison can be extended to Kanji numerals. Experiment 3 successfully demonstrated that rapid proportion judgments can be found with non-quantitative Kanji letters that are used frequently. Experiment 4 further demonstrated the rapid proportion comparison with frequently used meaningful non-letter symbols (gender icons). The rapid processing cannot be attributed to fluent processing of familiar items, because it was not found with familiar phonograms (Japanese Kana letters). These findings suggest that the rapid proportion comparison can be commonly found with frequently used meaningful symbols, even though their meaning is not relevant to the task.

Integration of vascular systems between the brain and spinal cord in zebrafish.

Cerebral and spinal vascular systems are organized individually, and they then conjugate at their border, through the integration of basilar artery and vertebral arteries. Zebrafish (Danio rerio) is an ideal organism for studying early vascular development, and the precise procedure of cranial and truncal vascular formation has been previously demonstrated using this model. However, the stepwise process of the integration between the brain and spinal cord has not been clearly elucidated. In this study, we describe the integration of the independent vascular systems for the brain and spinal cord, using transgenic zebrafish expressing enhanced green fluorescent protein in endothelial cells. Initially, basilar artery and primordial hindbrain channels, into which internal carotid arteries supplied blood, were connected with dorsal longitudinal anastomose vessels, via the first intersegmental artery. This initial connection was not influenced by flow dynamics, suggesting that vascular integration in this region is controlled by genetic cues. Vertebral arteries were formed individually as longitudinal vessels beneath the spinal cord, and became integrated with the basilar artery during subsequent remodeling. Furthermore, we confirmed the basal vasculature was well conserved in adult zebrafish. Observations of vascular integration presented herein will contribute to an understanding of regulatory mechanisms behind this process.

Stain on texture: perception of a dark spot having a blurred edge on textured backgrounds.

When distinguishing illumination from reflectance edges, both edge blurriness and textural continuity across an edge are generally used as cues to promote the illumination-edge interpretation. However, when these cues were combined, i.e., when a dark spot having a blurred edge was placed on textured backgrounds, we unexpectedly found that the spot appears stained or painted rather than differently illuminated ("stain on texture" phenomenon). This phenomenon suggests a disruptive interaction between the visual processing of blurred edges and background texture. Our experiments showed that middle spatial-frequency components of background texture play a critical role in producing this interaction. Specifically, when a textured background had relatively stronger energy in middle spatial-frequency bands, the dark spot having a blurred edge on the textured background was perceived as differing in reflectance. The findings are discussed in view of multiple levels of visual processes: one mainly concerns low-level features such as spatial-frequency components and another is a higher-level process that takes into account the likelihood of spatial configurations in natural scenes, such as "spot shadow" in which the shadow is isolated and the shadow caster is out of sight.

Contribution of a luminance-dependent S-cone mechanism to non-assimilative color spreading in the watercolor configuration.

In the watercolor configuration composed of wavy double contours, both assimilative and non-assimilative color spreading have been demonstrated depending on the luminance conditions of the inner and outer contours (IC and OC, respectively). This study investigated how the induced color in the watercolor configuration was modulated by combinations of the IC and the OC color, particularly addressing non-assimilative color spreading. In two experiments, the IC color was fixed to a certain color and combined with various colors selected from a hue circle centered at the background white color. Color spreading was quantified with a chromatic cancelation technique. Results showed that both the magnitude and the apparent hue of the color spreading were largely changed with the luminance condition. When the IC contrast (Weber contrast of the IC to the background luminance) was smaller in size than the OC contrast (higher IC luminance condition), the color spreading was assimilative. When the luminance condition was reversed and the IC contrast was greater than the OC contrast (lower IC luminance condition), the color spreading was non-assimilative and yellowish. When the color spreading was analyzed in terms of cone-opponent excitations, the results were consistent with the interpretation that the color spreading is explainable by a combination of chromatic diffusion from the IC and chromatically opponent induction from the OC. The color spreading in the higher IC luminance condition mainly reflected the chromatic diffusion by both (L-M) and S cone-opponent mechanisms. The non-assimilative color spreading in the lower IC luminance condition mostly reflected S-cone mediated opponent induction and the contribution of -S inducing mechanisms was differentially large. These findings provided several constraints on possible visual mechanisms underlying the watercolor effect.

Assimilative and non-assimilative color spreading in the watercolor configuration.

A colored line flanking a darker contour will appear to spread its color onto an area enclosed by the line (watercolor effect). The watercolor effect has been characterized as an assimilative effect, but non-assimilative color spreading has also been demonstrated in the same spatial configuration; e.g., when a black inner contour (IC) is paired with a blue outer contour (OC), yellow color spreading can be observed. To elucidate visual mechanisms underlying these different color spreading effects, this study investigated the effects of luminance ratio between the double contours on the induced color by systematically manipulating the IC and the OC luminance (Experiment 1) as well as the background luminance (Experiment 2). The results showed that the luminance conditions suitable for assimilative and non-assimilative color spreading were nearly opposite. When the Weber contrast of the IC to the background luminance (IC contrast) was smaller in size than that of the OC (OC contrast), the induced color became similar to the IC color (assimilative spreading). In contrast, when the OC contrast was smaller than or equal to the IC contrast, the induced color became yellow (non-assimilative spreading). Extending these findings, Experiment 3 showed that bilateral color spreading, i.e., assimilative spreading on one side and non-assimilative spreading on the other side, can also be observed in the watercolor configuration. These results suggest that the assimilative and the non-assimilative spreading were mediated by different visual mechanisms. The properties of the assimilative spreading are consistent with the model proposed to account for neon color spreading (Grossberg and Mingolla, 1985) and extended for the watercolor effect (Pinna and Grossberg, 2005). However, the present results suggest that additional mechanisms are needed to account for the non-assimilative color spreading.

Design, synthesis, and biological activities of 1-aryl-1,4-diazepan-2-one derivatives as novel triple reuptake inhibitors.

A novel series of triple reuptake inhibitors were explored by ligand-based drug design. A cyclic structure was designed from cyclopropane derivative 5 using the core structure of reported monoamine reuptake inhibitors, leading to the formation of the 1-aryl-1,4-diazepan-2-one derivative 23j-S. Compound 23j-S was shown to act as a potent TRI with an excellent ADME-Tox profile. Oral administration of 23j-S significantly enhanced norepinephrine, dopamine, and serotonin levels in the mouse prefrontal cortex and showed significant antidepressant-like activity in tail suspension tests in mouse.

Attenuation of the pupillary response to luminance and color changes during interocular suppression.

The present study investigated the effects of interocular suppression on the pupillary constriction to luminance and color changes. Stable interocular suppression was produced by presenting a flickering high-contrast grating to one eye and a spatially homogeneous field to the other eye. The results showed that the pupillary responses to luminance as well as color changes were clearly attenuated during interocular suppression; the pupillary constriction to stimulus changes was delayed and reduced in amplitude when those changes occurred in the suppressed eye. The attenuation of the pupillary response was observed over a wide range of test contrast extending to well above the threshold level. Moreover, the properties of the suppressive effect were very similar to those assessed psychophysically using both detection thresholds for weak stimuli and reaction times for suprathreshold stimuli. Overall, the present study provided converging evidence that the pupillary response can be a useful objective probe of interocular suppression in humans. The results are discussed in view of possible differential involvements of subcortical and cortical visual processing in driving the pupillary response as well as in interocular suppression.