Distinct effects of heat shock temperatures on mitotic progression by influencing the spindle assembly checkpoint.

Heat shock is a physiological and environmental stress that leads to the denaturation and inactivation of cellular proteins and is used in hyperthermia cancer therapy. Previously, we revealed that mild heat shock (42 °C) delays the mitotic progression by activating the spindle assembly checkpoint (SAC). However, it is unclear whether SAC activation is maintained at higher temperatures than 42 °C. Here, we demonstrated that a high temperature of 44 °C just before mitotic entry led to a prolonged mitotic delay in the early phase, which was shortened by the SAC inhibitor, AZ3146, indicating SAC activation. Interestingly, mitotic slippage was observed at 44 °C after a prolonged delay but not at 42 °C heat shock. Furthermore, the multinuclear cells were generated by mitotic slippage in 44 °C-treated cells. Immunofluorescence analysis revealed that heat shock at 44 °C reduces the kinetochore localization of MAD2, which is essential for mitotic checkpoint activation, in nocodazole-arrested mitotic cells. These results indicate that 44 °C heat shock causes SAC inactivation even after full activation of SAC and suggest that decreased localization of MAD2 at the kinetochore is involved in heat shock-induced mitotic slippage, resulting in multinucleation. Since mitotic slippage causes drug resistance and chromosomal instability, we propose that there may be a risk of cancer malignancy when the cells are exposed to high temperatures.

Shape variety of food can boost its visual appeal.

We investigated whether food shape and its variety within a group affect visual appeal using a four-shaped fast-food chicken product known as Chicken McNuggets®. In Experiment 1, participants rated the visual appeal of each nugget shape both individually and when presented in groups of variously shaped nuggets. The results revealed that the rounder nugget was less visually appealing than those of other shapes. Additionally, assortments featuring various shapes were rated as more appealing than those of a single shape. In Experiment 2, the visual appeal of individual nuggets presented in groups and alone was assessed using a visual analog scale. The visual appeal of one specific nugget (target nugget) was higher when presented in a group than alone. Furthermore, a target nugget presented in a group with various shapes was more visually appealing than when presented in a group with the same shape, regardless of the shape of the target nugget. These results suggest that a food product with low visual appeal can be perceived as more appealing when it is presented alongside various food shapes. Indeed, the variety of food shapes presented in a group affected the perceived appeal both of the group and of the individual food item. These findings offer novel insights into the impact of food's visual variation on its appeal.

Plantainoside B in Bacopa monniera Binds to Aß Aggregates Attenuating Neuronal Damage and Memory Deficits Induced by Aß.

Alzheimer's disease (AD) is a progressive neurodegenerative disease characterized by dementia. The most characteristic pathological changes in AD brain include extracellular amyloid-ß (Aß) accumulation and neuronal loss. Particularly, cholinergic neurons in the nucleus basalis of Meynert are some of the first neuronal groups to degenerate; accumulating evidence suggests that Aß oligomers are the primary form of neurotoxicity. Bacopa monniera is a traditional Indian memory enhancer whose extract has shown neuroprotective and Aß-reducing effects. In this study, we explored the low molecular weight compounds from B. monniera extracts with an affinity to Aß aggregates, including its oligomers, using Aß oligomer-conjugated beads and identified plantainoside B. Plantainoside B exhibited evident neuroprotective effects by preventing Aß attachment on the cell surface of human induced pluripotent stem cell (hiPSC)-derived cholinergic neurons. Moreover, it attenuated memory impairment in mice that received intrahippocampal Aß injections. Furthermore, radioisotope experiments revealed that plantainoside B has affinity to Aß aggregates including its oligomers and brain tissue from a mouse model of Aß pathology. In addition, plantainoside B could delay the Aß aggregation rate. Accordingly, plantainoside B may exert neuroprotective effects by binding to Aß oligomers, thus interrupting the binding of Aß oligomers to the cell surface. This suggests its potential application as a theranostics in AD, simultaneously diagnostic and therapeutic drugs.

Innovative experimental animal models for real-time comparison of antithrombogenicity between two oxygenators using dual extracorporeal circulation circuits and indocyanine green fluorescence imaging.

BACKGROUND: Antithrombogenicity of extracorporeal membrane oxygenation (ECMO) devices, particularly oxygenators, is a current problem, with numerous studies and developments underway. However, there has been limited progress in developing methods to accurately compare the antithrombogenicity of oxygenators. Animal experiments are commonly conducted to evaluate the antithrombogenicity of devices; however, it is challenging to maintain a steady experimental environment. We propose an innovative experimental animal model to evaluate different devices in a constant experimental environment in real-time. METHODS: This model uses two venous-arterial ECMO circuits attached to one animal (one by jugular vein and carotid artery, one by femoral vein and artery) and real-time assessment of thrombus formation in the oxygenator by indocyanine green (ICG) fluorescence imaging. Comparison studies were conducted using three pigs: one to compare different oxygenators (MERA vs. CAPIOX) (Case 1), and two to compare antithrombotic properties of the oxygenator (QUADROX) when used under different hydrodynamic conditions (continuous flow vs. pulsatile flow) (Cases 2 and 3). RESULTS: Thrombi, visualized using ICG imaging, appeared as black dots on a white background in each oxygenator. In Case 1, differences in the site of thrombus formation and rate of thrombus growth were observed in real-time in two oxygenators. In Case 2 and 3, the thrombus region was smaller in pulsatile than in continuous conditions. CONCLUSIONS: We devised an innovative experimental animal model for comparison of antithrombogenicity in ECMO circuits. This model enabled simultaneous evaluation of two different ECMO circuits under the same biological conditions and reduced the number of sacrificed experimental animals.

IMPACT OF GAS/AIR TAMPONADE ON REFRACTIVE OUTCOMES AFTER FLANGED INTRASCLERAL INTRAOCULAR LENS FIXATION.

PURPOSE: This study aims to investigate the postoperative refractive outcomes in eyes that underwent the flanged intrascleral intraocular lens (IOL) fixation combined with vitrectomy with or without gas/air tamponade. METHODS: The eyes were divided into two groups (Group A; eyes that underwent flanged intrascleral IOL fixation with gas/air tamponade, and Group B; eyes that underwent flanged intrascleral IOL fixation without gas/air tamponade). The predicted spherical equivalent (SE) refraction values were calculated using the Sander-Retzlaff-Kraff Theoretical formula. Then, the prediction error was calculated by subtracting the predicted SE refraction from the postoperative objective SE refraction and the absolute prediction error was calculated as the absolute value of the prediction error for each eye. RESULTS: A total of 68 eyes were included in the current study. There was a significant correlation between the predicted and postoperative SE refraction in both groups (Group A, r = 0.968, P < 0.0001, Group B, r = 0.943, P < 0.0001, linear regression analysis). The prediction error demonstrated a mild myopic shift after the flanged intrascleral IOL fixation in both groups (Group A, -0.40 ± 0.96 diopter, Group B, -0.59 ± 0.95 diopter). There was no significant difference in prediction error and absolute prediction error between the two groups ( P = 0.44, P = 0.70, Wilcoxon rank sum test). CONCLUSION: The postoperative SE refraction after flanged intrascleral IOL fixation was not influenced by gas/air tamponade.

Mutations in PIH proteins MOT48, TWI1 and PF13 define common and unique steps for preassembly of each, different ciliary dynein.

Ciliary dyneins are preassembled in the cytoplasm before being transported into cilia, and a family of proteins containing the PIH1 domain, PIH proteins, are involved in the assembly process. However, the functional differences and relationships between members of this family of proteins remain largely unknown. Using Chlamydomonas reinhardtii as a model, we isolated and characterized two novel Chlamydomonas PIH preassembly mutants, mot48-2 and twi1-1. A new allele of mot48 (ida10), mot48-2, shows large defects in ciliary dynein assembly in the axoneme and altered motility. A second mutant, twi1-1, shows comparatively smaller defects in motility and dynein assembly. A double mutant mot48-2; twi1-1 displays greater reduction in motility and in dynein assembly compared to each single mutant. Similarly, a double mutant twi1-1; pf13 also shows a significantly greater defect in motility and dynein assembly than either parent mutant. Thus, MOT48 (IDA10), TWI1 and PF13 may define different steps, and have partially overlapping functions, in a pathway required for ciliary dynein preassembly. Together, our data suggest the three PIH proteins function in preassembly steps that are both common and unique for different ciliary dyneins.

Signaling between pancreatic ß cells and macrophages via S100 calcium-binding protein A8 exacerbates ß-cell apoptosis and islet inflammation.

Chronic low-grade inflammation in the pancreatic islets is observed in individuals with type 2 diabetes, and macrophage levels are elevated in the islets of these individuals. However, the molecular mechanisms underlying the interactions between the pancreatic ß cells and macrophages and their involvement in inflammation are not fully understood. Here, we investigated the role of S100 calcium-binding protein A8 (S100A8), a member of the damage-associated molecular pattern molecules (DAMPs), in ß-cell inflammation. Co-cultivation of pancreatic islets with unstimulated peritoneal macrophages in the presence of palmitate (to induce lipotoxicity) and high glucose (to induce glucotoxicity) synergistically increased the expression and release of islet-produced S100A8 in a Toll-like receptor 4 (TLR4)-independent manner. Consistently, a significant increase in the expression of the S100a8 gene was observed in the islets of diabetic db/db mice. Furthermore, the islet-derived S100A8 induced TLR4-mediated inflammatory cytokine production by migrating macrophages. When human islet cells were co-cultured with U937 human monocyte cells, the palmitate treatment up-regulated S100A8 expression. This S100A8-mediated interaction between islets and macrophages evoked ß-cell apoptosis, which was ameliorated by TLR4 inhibition in the macrophages or S100A8 neutralization in the pancreatic islets. Of note, both glucotoxicity and lipotoxicity triggered S100A8 secretion from the pancreatic islets, which in turn promoted macrophage infiltration of the islets. Taken together, a positive feedback loop between islet-derived S100A8 and macrophages drives ß-cell apoptosis and pancreatic islet inflammation. We conclude that developing therapeutic approaches to inhibit S100A8 may serve to prevent ß-cell loss in patients with diabetes.

The Oxidative Pathway to Dopamine-Protein Conjugates and Their Pro-Oxidant Activities: Implications for the Neurodegeneration of Parkinson's Disease.

Neuromelanin (NM) is a dark brown pigment found in dopaminergic neurons of the substantia nigra (SN) and in norepinephrinergic neurons of the locus coeruleus (LC). Although NM is thought to be involved in the etiology of Parkinson's disease (PD) because its content decreases in neurodegenerative diseases such as PD, details are still unknown. In this study, we characterized the biosynthetic pathway of the oxidation of dopamine (DA) by tyrosinase in the presence of thiol peptides and proteins using spectroscopic and high-performance liquid chromatography (HPLC) methods and we assessed the binding of DA via cysteine residues in proteins by oxidation catalyzed by redox-active metal ions. To examine whether the protein-bound DA conjugates exhibit pro-oxidant activities, we measured the depletion of glutathione (GSH) with the concomitant production of hydrogen peroxide. The results suggest that the fate of protein-bound DA conjugates depends on the structural features of the proteins and that DA-protein conjugates produced in the brain possess pro-oxidant activities, which may cause neurodegeneration due to the generation of reactive oxygen species (ROS) and the depletion of antioxidants.

Homogeneous perdehydrogenation and perhydrogenation of fused bicyclic N-heterocycles catalyzed by iridium complexes bearing a functional bipyridonate ligand.

Homogeneous perdehydrogenation of saturated bicyclic 2,6-dimethyldecahydro-1,5-naphthyridine and perhydrogenation of aromatic 2,6-dimethyl-1,5-naphthyridine with release and uptake of five molecules of H2 are efficiently achieved by iridium complexes bearing a functional bipyridonate ligand. Successive perhydrogenation and perdehydrogenation of 2,6-dimethyl-1,5-naphthryridine using a single iridium complex also proceed with the reversible interconversion of the catalytic species, depending on the presence or absence of H2.

Retinal haemorrhages on ultra-widefield red channel images and perfusion status in central retinal vein occlusion.

PURPOSE: To evaluate the relationship between retinal haemorrhages detected on Ultra-widefield (UWF) red channel images and perfusion status in eyes with acute central retinal vein occlusion (CRVO). METHODS: UWF fundus images were split into green and red channels using ImageJ software. The retinal haemorrhages were calculated quantitatively with both the green and red channel images, resulting in green channel haemorrhages (GCH) and red channel haemorrhages (RCH). The nonperfusion area (NPA) was also calculated from fluorescein angiography in each eye. The relationships between both the GCH and RCH with the NPA were investigated. RESULTS: Thirty-two eyes of 32 patients with acute CRVO (18 men, 14 women) were included. The mean GCH and RCH values were 10.4% ± 8.2% and 1.7% ± 1.7%, respectively. The mean NPA was 39.2% ± 28.8%. Significant correlations were seen between the GCH and NPA (r = 0.38; P = 0.022) and RCH and NPA (r = 0.44; P = 0.010, linear regression analysis). Multivariate analysis suggested that only the RCHs were correlated significantly with the NPA. CONCLUSIONS: Retinal haemorrhages detected by UWF red channel imaging were less compared to green channel imaging and associated closely with retinal NPAs in eyes with acute CRVO. UWF red channel imaging allowed us to identify ischaemia-related haemorrhage.

Identification and characterization of a serine racemase in the silkworm Bombyx mori.

The pupae of lepidopterans contain high concentrations of endogenous d-serine. In the silkworm Bombyx mori, d-serine is negligible during the larval stage but increases markedly during the pupal stage, reaching 50% of the total free serine. However, the physiological function of d-serine and the enzyme responsible for its production is unknown. Herein, we identified a new type of pyridoxal 5'-phosphate (PLP)-dependent serine racemase (SR) that catalyses the racemization of l-serine to d-serine in B. mori. This silkworm SR (BmSR) has an N-terminal PLP-binding domain that is homologous to mammalian SR and a C-terminal putative ligand-binding regulatory-like domain (ACT-like domain) that is absent in mammalian SR. Similar to mammalian SRs, BmSR catalyses the racemization and dehydration of both serine isomers. However, BmSR is different from mammalian SRs as evidenced by its insensitivity to Mg2+/Ca2+ and Mg-ATP-which are required for activation of mammalian SRs-and high d-serine dehydration activity. At the pupal stage, the SR activity was predominantly detected in the fat body, which was consistent with the timing and localization of BmSR expression. The results are an important first step in elucidating the physiological significance of d-serine in lepidopterans.

Foveal microstructure and visual function in patients with lamellar macular hole, epiretinal membrane foveoschisis or macular pseudohole.

PURPOSE: To compare the foveal microstructures, such as the prevalence of epiretinal proliferation (EP) and residual ellipsoid zone (EZ), in eyes with lamellar macular hole (LMH), epiretinal retinal membrane (ERM) foveoschisis and macular pseudohole (MPH), and to investigate the association of the foveal microstructure with visual functions. METHOD: In addition to the prevalence of EP, we calculated the residual EZ index within 1mm and 3 mm (rEZ1 and rEZ3) in all examined eyes. Comparisons were conducted to baseline characteristics (logMAR visual acuity [logMAR VA], metamorphopsia score [Mave], central retinal thickness [CRT], the prevalence of EP, rEZ1 and rEZ3) between MPH, ERM foveoschisis and LMH subgroups. The relationships (1) between logMAR VA and each of age, type (MPH, ERM foveoschisis and LMH), the prevalence of EP, rEZ1, rEZ3, spherical equivalent (SE) and CRT and (2) between Mave and each of variables were investigated. RESULTS: Fifty-one eyes of 48 patients were enroled. The mean age was 65.2 ± 11.1 years. Ten eyes were diagnosed as LMH, 22 eyes as ERM foveoschisis and 19 eyes as MPH, respectively. There was a significant difference in CRT only between LMH and ERM foveoschisis (p = 0.023). There was a tendency toward significance in rEZ1 between LMH and ERM foveoschisis (p = 0.057), but not in rEZ3. The optimal model for logMAR VA included age, rEZ1, SE and CRT. On the other hand, the optimal model for Mave included the prevalence of EP, rEZ1 and SE. CONCLUSION: Microstructural observations are useful to predict visual functions in LMH, ERM foveoshisis and MPH.

Endophthalmitis outbreak caused by Fusarium oxysporum after cataract surgery.

PURPOSE: To evaluate an outbreak of endophthalmitis caused by Fusarium oxysporum after cataract surgery. METHODS: In the present study, we conducted a retrospective review of the medical records of cases of endophthalmitis that developed after cataract surgery. All eyes underwent phacoemulsification and intraocular lens implantation (PEA + IOL) at a single eye clinic on the same date. Symptoms of endophthalmitis occurred 21.5 ± 3.4 days after the cataract surgery. RESULTS: Nine eyes of 9 patients with fungal endophthalmitis (5 males and 4 females) were enrolled in the current study. The mean age of the patients was 63.4 ± 8.5 years. Soon after the diagnosis of endophthalmitis, pars plana vitrectomy (PPV) had been performed in all the eyes. However, because there was no response to the first PPV plus antibacterial drug therapy, we performed repeat PPV for all the eyes, combined with IOL removal and antifungal therapy (natamycin eye drops plus oral voriconazole or fosfluconazole). After the antifungal drug therapy, no recurrence of endophthalmitis was observed in any of the operated eyes, and good visual outcomes were obtained. Fusarium oxysporum was identified by culture and sequencing analysis. CONCLUSION: Early diagnosis and appropriate, adequate treatment are needed for successful management of fungal endophthalmitis.

Using ultra-widefield red channel images to improve the detection of ischemic central retinal vein occlusion.

PURPOSE: To examine the usefulness of red channel fundus imaging to detect the ischemic status in eyes with central retinal vein occlusion (CRVO). METHODS: Ultra-widefield (UWF) fundus images were obtained from 42 eyes with CRVO. Twenty-one eyes were ischemic, and 21 eyes were non-ischemic. Rubeosis was found in 11 ischemic eyes. UWF images were split into red and green channels using ImageJ software. Both the color and red channel images were used to predict the presence or absence of ischemia when examined by masked graders. The sensitivity and specificity of UWF imagings for the detection of ischemia were calculated in Group A (total 42 eyes), Group B (32 eyes excluding non-rubeotic ischemic CRVO) and Group C (31 eyes excluding rubeotic ischemic CRVO), respectively. Moreover, a linear mixed model was conducted to investigate the relationship between the type of images and the accuracy of prediction in each group. RESULTS: No significant difference in the sensitivity of color fundus imaging was seen between Group A and Group B. By contrast, a significant difference in the sensitivity of red channel imaging was seen between Group A and Group B (p = 0.031). The accuracies of the predictions were not associated with the type of image in Group A and Group B, but were significantly associated in Group C (p = 0.026). CONCLUSIONS: UWF red channel imaging enabled more accurate detection of the ischemic status, compared with color fundus images, especially in non-rubeotic CRVO eyes.

A dynein-associated photoreceptor protein prevents ciliary acclimation to blue light.

Light-responsive regulation of ciliary motility is known to be conducted through modulation of dyneins, but the mechanism is not fully understood. Here, we report a novel subunit of the two-headed f/I1 inner arm dynein, named DYBLUP, in animal spermatozoa and a unicellular green alga. This subunit contains a BLUF (sensors of blue light using FAD) domain that appears to directly modulate dynein activity in response to light. DYBLUP (dynein-associated BLUF protein) mediates the connection between the f/I1 motor domain and the tether complex that links the motor to the doublet microtubule. Chlamydomonas lacking the DYBLUP ortholog shows both positive and negative phototaxis but becomes acclimated and attracted to high-intensity blue light. These results suggest a mechanism to avoid toxic strong light via direct photoregulation of dyneins.

In vitro apatite formation and drug loading/release of porous TiO2 microspheres prepared by sol-gel processing with different SiO2 nanoparticle contents.

Bioactive titania (TiO2) microparticles can be used as drug-releasing cement fillers for the chemotherapeutic treatment of metastatic bone tumors. Porous anatase-type TiO2 microspheres around 15 µm in diameter were obtained through a sol-gel process involving a water-in-oil emulsion with 30:70 SiO2/H2O weight ratio and subsequent NaOH solution treatment. The water phase consisted of methanol, titanium tetraisopropoxide, diethanolamine, SiO2 nanoparticles, and H2O, while the oil phase consisted of kerosene, Span 80, and Span 60. The resulting microspheres had a high specific surface area of 111.7 m(2)·g(-1). Apatite with a network-like surface structure formed on the surface of the microspheres within 8 days in simulated body fluid. The good apatite-forming ability of the microspheres is attributed to their porous structure and the negative zeta potential of TiO2. The release of rhodamine B, a model for a hydrophilic drug, was rapid for the first 6 h of soaking, but diffusion-controlled thereafter. The burst release in the first 6h is problematic for clinical applications; nonetheless, the present results highlight the potential of porous TiO2 microspheres as drug-releasing cement fillers able to form apatite.