Morphologies of Comb-like Polyacrylic Acid/Polyacrylate Copolymers as Functions of the Degree of Derivatization with n-C22H45 Side Chains.

Polymers with crystallizable side chains have numerous applications, and their properties depend on their crystal morphologies and phase separation. Structural analysis on a wide spatial scale plays an important role in controlling the thermal properties and higher-order structures of these polymers. In this study, we elucidated the melting and crystallization processes of copolymers with varying crystallizable side-chain fractions over a wide spatial range. Differential scanning calorimetry revealed that the enthalpies of melting and crystallization increased linearly with increasing crystallizable side-chain fraction. The results of wide-angle X-ray scattering indicated that the crystal lattice was hexagonal. Conversely, spherulite-like higher-order architectures with linear structures and radial spreading were observed in the highly crystallizable components, but no micrometer-scale structures were observed in the less crystallizable components. In situ small-angle X-ray scattering was used to elucidate the phase separation and mixing processes. Lamellar crystallites were observed at crystallizable side-chain fractions of >55 wt.%, whereas small crystallites were observed at fractions of <45 wt.%. At temperatures above the order-disorder transition temperature, density fluctuations caused by correlation holes were observed. These properties have a strong effect on the crystallizable side-chain fraction.

Oxidative Synthesis of Acid Blue 7 Dye Catalyzed by CuO/Silicotungstic Acid in Water-Phase.

A catalytic oxidation reaction for Acid Blue 7 dye synthesis was evaluated in water. Without lead oxide or manganese oxide derivatives as oxidants, polyoxometalate catalysts were investigated to reduce the usage of harmful heavy metal. A catalyst was prepared by mixing silicotungstic acid with copper oxide, and aqueous hydrogen peroxide (30%) was used as an oxidizing agent. This reaction proceeded to produce Acid Blue 7 from the corresponding leuco acid after 45 min at 95 °C and was viable for a 10 g-scale synthesis.

Properties of primary cilia in melanin-concentrating hormone receptor 1-bearing hippocampal neurons in vivo and in vitro.

The primary cilium is a solitary organelle that organizes a sensitive signaling hub in a highly ordered microenvironment. Cilia are plastic structures, changing their length in response to bioactive substances, and ciliary length may be regulated to ensure efficient signaling capacity. Mammalian brain neurons possess primary cilia that are enriched in a set of G protein-coupled receptors (GPCRs), including the feeding-related melanin-concentrating hormone (MCH) receptor 1 (MCHR1). We previously demonstrated a novel biological phenomenon, ciliary MCHR1-mediated cilia length shortening through Gi/o and Akt signaling, using a simple cell culture model of human retinal pigmented epithelial RPE1 cells exogenously expressing MCHR1. In the present study, we characterized the properties of endogenous MCHR1-expressing primary cilia in hippocampal neurons in rodents. Using cultured dissociated rat hippocampal neurons in vitro, we showed that MCH triggered cilia length reduction involved in MCHR1-Gi/o and -Akt signaling. In rat hippocampal slice cultures with preservation of the cytoarchitecture and cell populations, ciliary MCHR1 was abundantly located in the CA1 and CA3 regions, but not in the dentate gyrus. Notably, treatment of slice cultures with MCH induced Gi/o- and Akt-dependent cilia shortening in the CA1 region without influencing cilia length in the CA3 region. Regarding the in vivo mouse brain, we observed higher levels of ciliary MCHR1 in the CA1 and CA3 regions as well as in slice cultures. In the starved state mice, a marked increase in MCH mRNA expression was detected in the lateral hypothalamus. Furthermore, MCHR1-positive cilia length in the hippocampal CA1 region was significantly shortened in fasted mice compared with fed mice. The present findings focused on the hippocampus provide a potential approach to investigate how MCHR1-driven cilia shortening regulates neuronal activity and physiological function toward feeding and memory tasks.

Characterization of Functional Primary Cilia in Human Induced Pluripotent Stem Cell-Derived Neurons.

Recent advances in human induced pluripotent stem cells (hiPSCs) offer new possibilities for biomedical research and clinical applications. Neurons differentiated from hiPSCs may be promising tools to develop novel treatment methods for various neurological diseases. However, the detailed process underlying functional maturation of hiPSC-derived neurons remains poorly understood. Here, we analyze the developmental architecture of hiPSC-derived cortical neurons, iCell GlutaNeurons, focusing on the primary cilium, a single sensory organelle that protrudes from the surface of most growth-arrested vertebrate cells. To characterize the neuronal cilia, cells were cultured for various periods and evaluated immunohistochemically by co-staining with antibodies against ciliary markers Arl13b and MAP2. Primary cilia were detected in neurons within days, and their prevalence and length increased with increasing days in culture. Treatment with the mood stabilizer lithium led to primary cilia length elongation, while treatment with the orexigenic neuropeptide melanin-concentrating hormone caused cilia length shortening in iCell GlutaNeurons. The present findings suggest that iCell GlutaNeurons develop neuronal primary cilia together with the signaling machinery for regulation of cilia length. Our approach to the primary cilium as a cellular antenna can be useful for both assessment of neuronal maturation and validation of pharmaceutical agents in hiPSC-derived neurons.

Depression-resistant Phenotype in Mice Overexpressing Regulator of G Protein Signaling 8 (RGS8).

Regulator of G protein signaling (RGS) proteins are negative regulators of heterotrimeric G proteins that act by accelerating Gα-mediated GTPase activity to terminate G protein-coupled receptor-associated signaling. RGS8 is expressed in several brain regions involved with movement and mood. To investigate the role of RGS8 in vivo, we generated transgenic mice overexpressing brain RGS8 (RGS8tg). RGS8 gene and protein expressions were examined by real-time PCR and immunohistochemistry, respectively, and a significant increase in RGS8 protein was detected in the hippocampal CA1 region compared with wild-type mice (WT). We characterized the phenotypic traits, and found that RGS8tg showed decreased depressive-like behavior in the forced swimming test (FST). Previously, RGS8 was identified as a potent negative regulator of melanin-concentrating hormone receptor 1 (MCHR1), whose activation is mainly involved in energy homeostasis and emotional processing. Interestingly, acute oral administration of MCHR1 antagonist SNAP94847 did not have antidepressant-like effects on RGS8tg in the FST, but did show antidepressant effects on WT. In contrast, selective noradrenaline reuptake inhibitor desipramine had a significant effect on RGS8tg in the FST. MCHR1 is enriched in a subset of primary cilia, as sensory organelles that mediate extracellular signaling. Immunohistochemical analyses revealed significant elongation of MCHR1-positive cilia in the CA1 region of RGS8tg compared with WT. Taken together, these findings suggest that RGS8 participates in modulation of depression-like behavior through ciliary MCHR1 expressed in the CA1 region. The present study may support the possible modulation of RGS8 function in mood disorders.