Intranasal Administration of Mesenchymal Stem Cell-Derived Exosome Alleviates Hypoxic-Ischemic Brain Injury.

Hypoxic-ischemic brain injury arises from inadequate oxygen delivery to the brain, commonly occurring following cardiac arrest, which lacks effective treatments. Recent studies have demonstrated the therapeutic potential of exosomes released from mesenchymal stem cells. Given the challenge of systemic dilution associated with intravenous administration, intranasal delivery has emerged as a promising approach. In this study, we investigate the effects of intranasally administered exosomes in an animal model. Exosomes were isolated from the cell supernatants using the ultracentrifugation method. Brain injury was induced in Sprague-Dawley rats through a transient four-vessel occlusion model. Intranasal administration was conducted with 3 × 108 exosome particles in 20 µL of PBS or PBS alone, administered daily for 7 days post-injury. Long-term cognitive behavioral assessments, biodistribution of exosomes, and histological evaluations of apoptosis and neuroinflammation were conducted. Exosomes were primarily detected in the olfactory bulb one hour after intranasal administration, subsequently distributing to the striatum and midbrain. Rats treated with exosomes exhibited substantial improvement in cognitive function up to 28 days after the insult, and demonstrated significantly fewer apoptotic cells along with higher neuronal cell survival in the hippocampus. Exosomes were found to be taken up by microglia, leading to a decrease in the expression of cytotoxic inflammatory markers.

Phenotypes for general behavior, activity, and body temperature in 3q29 deletion model mice.

Whole genome analysis has identified rare copy number variations (CNV) that are strongly involved in the pathogenesis of psychiatric disorders, and 3q29 deletion has been found to have the largest effect size. The 3q29 deletion mice model (3q29-del mice) has been established as a good pathological model for schizophrenia based on phenotypic analysis; however, circadian rhythm and sleep, which are also closely related to neuropsychiatric disorders, have not been investigated. In this study, our aims were to reevaluate the pathogenesis of 3q29-del by recreating model mice and analyzing their behavior and to identify novel new insights into the temporal activity and temperature fluctuations of the mouse model using a recently developed small implantable accelerometer chip, Nano-tag. We generated 3q29-del mice using genome editing technology and reevaluated common behavioral phenotypes. We next implanted Nano-tag in the abdominal cavity of mice for continuous measurements of long-time activity and body temperature. Our model mice exhibited weight loss similar to that of other mice reported previously. A general behavioral battery test in the model mice revealed phenotypes similar to those observed in mouse models of schizophrenia, including increased rearing frequency. Intraperitoneal implantation of Nano-tag, a miniature acceleration sensor, resulted in hypersensitive and rapid increases in the activity and body temperature of 3q29-del mice upon switching to lights-off condition. Similar to the 3q29-del mice reported previously, these mice are a promising model animals for schizophrenia. Successive quantitative analysis may provide results that could help in treating sleep disorders closely associated with neuropsychiatric disorders.

Intravenous Administration of Mesenchymal Stem Cell-Derived Exosome Alleviates Spinal Cord Injury by Regulating Neutrophil Extracellular Trap Formation through Exosomal miR-125a-3p.

Spinal cord injury (SCI) leads to devastating sequelae, demanding effective treatments. Recent advancements have unveiled the role of neutrophil extracellular traps (NETs) produced by infiltrated neutrophils in exacerbating secondary inflammation after SCI, making it a potential target for treatment intervention. Previous research has established that intravenous administration of stem cell-derived exosomes can mitigate injuries. While stem cell-derived exosomes have demonstrated the ability to modulate microglial reactions and enhance blood-brain barrier integrity, their impact on neutrophil deactivation, especially in the context of NETs, remains poorly understood. This study aims to investigate the effects of intravenous administration of MSC-derived exosomes, with a specific focus on NET formation, and to elucidate the associated molecular mechanisms. Exosomes were isolated from the cell supernatants of amnion-derived mesenchymal stem cells using the ultracentrifugation method. Spinal cord injuries were induced in Sprague-Dawley rats (9 weeks old) using a clip injury model, and 100 µg of exosomes in 1 mL of PBS or PBS alone were intravenously administered 24 h post-injury. Motor function was assessed serially for up to 28 days following the injury. On Day 3 and Day 28, spinal cord specimens were analyzed to evaluate the extent of injury and the formation of NETs. Flow cytometry was employed to examine the formation of circulating neutrophil NETs. Exogenous miRNA was electroporated into neutrophil to evaluate the effect of inflammatory NET formation. Finally, the biodistribution of exosomes was assessed using 64Cu-labeled exosomes in animal positron emission tomography (PET). Rats treated with exosomes exhibited a substantial improvement in motor function recovery and a reduction in injury size. Notably, there was a significant decrease in neutrophil infiltration and NET formation within the spinal cord, as well as a reduction in neutrophils forming NETs in the circulation. In vitro investigations indicated that exosomes accumulated in the vicinity of the nuclei of activated neutrophils, and neutrophils electroporated with the miR-125a-3p mimic exhibited a significantly diminished NET formation, while miR-125a-3p inhibitor reversed the effect. PET studies revealed that, although the majority of the transplanted exosomes were sequestered in the liver and spleen, a notably high quantity of exosomes was detected in the damaged spinal cord when compared to normal rats. MSC-derived exosomes play a pivotal role in alleviating spinal cord injury, in part through the deactivation of NET formation via miR-125a-3p.

Nickel Carbide Nanoparticle Catalyst for Selective Hydrogenation of Nitriles to Primary Amines.

Despite its unique physicochemical properties, the catalytic application of nickel carbide (Ni3 C) in organic synthesis is rare. In this study, we report well-defined nanocrystalline Ni3 C (nano-Ni3 C) as a highly active catalyst for the selective hydrogenation of nitriles to primary amines. The activity of the aluminum-oxide-supported nano-Ni3 C (nano-Ni3 C/Al2 O3 ) catalyst surpasses that of Ni nanoparticles. Various aromatic and aliphatic nitriles and dinitriles were successfully converted to the corresponding primary amines under mild conditions (1 bar H2 pressure). Furthermore, the nano-Ni3 C/Al2 O3 catalyst was reusable and applicable to gram-scale experiments. Density functional theory calculations suggest the formation of polar hydrogen species on the nano-Ni3 C surface, which were attributed to the high activity of nano-Ni3 C towards nitrile hydrogenation. This study demonstrates the utility of metal carbides as a new class of catalysts for liquid-phase organic reactions.

Circadian control of sleep-related neuronal activity in lizards.

Although diurnal animals displaying monophasic sleep patterns exhibit periodic cycles of alternating slow-wave sleep (SWS) and rapid eye movement sleep (REMS), the regulatory mechanisms underlying these regular sleep cycles remain unclear. Here, we report that in the Australian dragon Pogona vitticeps exposed to constant darkness (DD), sleep behavior and sleep-related neuronal activity emerged over a 24-h cycle. However, the regularity of the REMS/SWS alternation was disrupted under these conditions. Notably, when the lizards were then exposed to 12 h of light after DD, the regularity of the sleep stages was restored. These results suggest that sleep-related neuronal activity in lizards is regulated by circadian rhythms and that the regularity of REMS and SWS cycling is influenced by daytime light exposure.

Iron phosphide nanocrystals as an air-stable heterogeneous catalyst for liquid-phase nitrile hydrogenation.

Iron-based heterogeneous catalysts are ideal metal catalysts owing to their abundance and low-toxicity. However, conventional iron nanoparticle catalysts exhibit extremely low activity in liquid-phase reactions and lack air stability. Previous attempts to encapsulate iron nanoparticles in shell materials toward air stability improvement were offset by the low activity of the iron nanoparticles. To overcome the trade-off between activity and stability in conventional iron nanoparticle catalysts, we developed air-stable iron phosphide nanocrystal catalysts. The iron phosphide nanocrystal exhibits high activity for liquid-phase nitrile hydrogenation, whereas the conventional iron nanoparticles demonstrate no activity. Furthermore, the air stability of the iron phosphide nanocrystal allows facile immobilization on appropriate supports, wherein TiO2 enhances the activity. The resulting TiO2-supported iron phosphide nanocrystal successfully converts various nitriles to primary amines and demonstrates high reusability. The development of air-stable and active iron phosphide nanocrystal catalysts significantly expands the application scope of iron catalysts.

Immunomodulatory amnion-derived mesenchymal stromal cells preserve muscle function in a mouse model of Duchenne muscular dystrophy.

BACKGROUND: Duchenne muscular dystrophy (DMD) is an incurable genetic disease characterized by degeneration and necrosis of myofibers, chronic inflammation, and progressive muscle weakness resulting in premature mortality. Immunosuppressive multipotent mesenchymal stromal cell (MSC) therapy could be an option for DMD patients. We focused on amnion-derived mesenchymal stromal cells (AMSCs), a clinically viable cell source owing to their unique characteristics, such as non-invasive isolation, mitotic stability, ethical acceptability, and minimal risk of immune reaction and cancer. We aimed to identify novel immunomodulatory effects of AMSCs on macrophage polarization and their transplantation strategies for the functional recovery of skeletal and cardiac muscles. METHODS: We used flow cytometry to analyze the expression of anti-inflammatory M2 macrophage markers on peripheral blood mononuclear cells (PBMCs) co-cultured with human AMSCs (hAMSCs). hAMSCs were intravenously injected into DMD model mice (mdx mice) to assess the safety and efficacy of therapeutic interventions. hAMSC-treated and untreated mdx mice were monitored using blood tests, histological examinations, spontaneous wheel-running activities, grip strength, and echocardiography. RESULTS: hAMSCs induced M2 macrophage polarization in PBMCs via prostaglandin E2 production. After repeated systemic hAMSC injections, mdx mice exhibited a transient downregulation of serum creatin kinase. Limited mononuclear cell infiltration and a decreased number of centrally nucleated fibers were indicative of regenerated myofibers following degeneration, suggesting an improved histological appearance of the skeletal muscle of hAMSC-treated mdx mice. Upregulated M2 macrophages and altered cytokine/chemokine expressions were observed in the muscles of hAMSC-treated mdx mice. During long-term experiments, a significant decrease in the grip strength in control mdx mice significantly improved in the hAMSC-treated mdx mice. hAMSC-treated mdx mice maintained running activity and enhanced daily running distance. Notably, the treated mice could run longer distances per minute, indicating high running endurance. Left ventricular function in DMD mice improved in hAMSC-treated mdx mice. CONCLUSIONS: Early systemic hAMSC administration in mdx mice ameliorated progressive phenotypes, including pathological inflammation and motor dysfunction, resulting in the long-term improvement of skeletal and cardiac muscle function. The therapeutic effects might be associated with the immunosuppressive properties of hAMSCs via M2 macrophage polarization. This treatment strategy could provide therapeutic benefits to DMD patients.

Ablation of microglia does not alter circadian rhythm of locomotor activity.

Microglia, as macrophages in the brain, are responsible for immune responses and synaptic remodeling. Although the function of microglia is regulated by circadian rhythms, it is still unclear whether microglia are involved in the generation and light entrainment of circadian rhythms of behavior. Here, we report that microglial depletion does not alter behavioral circadian rhythms. We depleted ~ 95% of microglia in the mouse brain by PLX3397, a CSF1R inhibitor, and analyzed the effect on the spontaneous behaviors of mice. We found that neither the free-running period under constant darkness nor light entrainment under jet-lag circumstances were influenced by the ablation of microglia. Our results demonstrate that the circadian rhythms of locomotor activity, an important output of the circadian clock in the brain, are likely a phenomenon not produced by microglia.

A copper nitride nanocube catalyst for highly efficient hydroboration of alkynes.

The hydroboration of alkynes with bis(pinacolato)diboron is a useful method for the synthesis of vinyl boronate esters, which are essential intermediates in organic syntheses. Copper catalysts have been used extensively in these reactions. However, previously reported Cu-catalyst systems inevitably require additives and elevated temperatures. Herein, we report, for the first time, a simple and efficient hydroboration of alkynes under additive-free and mild reaction conditions (i.e., at a temperature of 30 °C) using a copper nitride nanocube (Cu3N NC) catalyst. A wide range of alkynes can be transformed into their corresponding boronate esters. Cu3N NCs are also applicable in the hydroboration of alkynes with tetrahydroxydiboron to synthesize vinyl boronic acids. Moreover, the Cu3N NCs were easily separated by simple filtration and could be reused several times without any loss of their original activity. Hence, these highly active and reusable Cu3N NC catalysts offer an environmentally friendly route for the efficient production of vinyl boronates.

The regulation of circadian rhythm by insulin signaling in Drosophila.

Circadian rhythm is well conserved across species and relates to numerous biological functions. Circadian misalignment impairs metabolic function. Insulin signaling is a key modulator of metabolism in the fruit fly as well as mammals and its defects cause metabolic disease. Daily diet timing affects both circadian rhythmicities of behavior and metabolism. However, the relationship between the circadian clock and insulin signaling is still elusive. Here, we report that insulin signaling regulates circadian rhythm in Drosophila melanogaster. We found the insulin receptor substrate mutant, chico1, showed a shorter free-running circadian period. The knockdown of insulin receptor (InR), or another signaling molecule downstream of InR, dp110, or the expression of a dominant-negative form of InR resulted in the shortening of the circadian period and diminished its amplitude. The impairment of insulin signaling both in all neurons and restricted circadian clock neurons altered circadian period length, indicating that the insulin signaling plays a role in the regulation of circadian rhythm in clock cells. Among 3 insulin-like ligands expressed in the brain, dilp5 showed the largest effect on circadian phenotype when deleted. These results suggested that insulin signaling contributes to the robustness of the circadian oscillation and coordinates metabolism and behavior.

Intravenous transplantation of amnion-derived mesenchymal stem cells promotes functional recovery and alleviates intestinal dysfunction after spinal cord injury.

Spinal cord injury (SCI) is often accompanied by gastrointestinal dysfunction due to the disconnection of the spinal autonomic nervous system. Gastrointestinal dysfunction reportedly upregulates intestinal permeability, leading to bacterial translocation of the gut microbiome to the systemic circulation, which further activates systemic inflammation, exacerbating neuronal damage. Mesenchymal stem cells (MSC) reportedly ameliorate SCI. Here, we aimed to investigate their effect on the associated gastrointestinal dysfunction. Human amnion-derived MSC (AMSCs) were intravenously transplanted one day after a rat model of midthoracic SCI. Biodistribution of transplanted cells, behavioral assessment, and histological evaluations of the spinal cord and intestine were conducted to elucidate the therapeutic effect of AMSCs. Bacterial translocation of the gut microbiome was examined by in situ hybridization and bacterial culture of the liver. Systemic inflammations were examined by blood cytokines, infiltrating immune cells in the spinal cord, and the size of the peripheral immune tissue. AMSCs released various neurotrophic factors and were mainly distributed in the liver and lung after transplantation. AMSC-transplanted animals showed smaller spinal damage and better neurological recovery with preserved neuronal tract. AMSCs transplantation ameliorated intestinal dysfunction both morphologically and functionally, which prevented translocation of the gut microbiome to the systemic circulation. Systemic inflammations were decreased in animals receiving AMSCs in the chronic phase. Intravenous AMSC administration during the acute phase of SCI rescues both spinal damage and intestinal dysfunction. Reducing bacterial translocation may contribute to decreasing systemic inflammation.

Selective Hydrodeoxygenation of Esters to Unsymmetrical Ethers over a Zirconium Oxide-Supported Pt-Mo Catalyst.

The catalytic hydrodeoxygenation (HDO) of carbonyl oxygen in esters using H2 is an attractive method for synthesizing unsymmetrical ethers because water is theoretically the sole coproduct. Herein, we report a heterogeneous catalytic system for the selective HDO of esters to unsymmetrical ethers over a zirconium oxide-supported platinum-molybdenum catalyst (Pt-Mo/ZrO2). A wide range of esters were transformed into the corresponding unsymmetrical ethers under mild reaction conditions (0.5 MPa H2 at 100 °C). The Pt-Mo/ZrO2 catalyst was also successfully applied to the conversion of a biomass-derived triglyceride into the corresponding triether. Physicochemical characterization and control experiments revealed that cooperative catalysis between Pt nanoparticles and neighboring molybdenum oxide species on the ZrO2 surface plays a key role in the highly selective HDO of esters. This Pt-Mo/ZrO2 catalyst system offers a highly efficient strategy for synthesizing unsymmetrical ethers and broadens the scope of sustainable reaction processes.

Phosphorus-Alloying as a Powerful Method for Designing Highly Active and Durable Metal Nanoparticle Catalysts for the Deoxygenation of Sulfoxides: Ligand and Ensemble Effects of Phosphorus.

The modification of metal nanoparticles (NPs) by incorporating additional metals is a key technique for developing novel catalysts. However, the effects of incorporating nonmetals into metal NPs have not been widely explored, particularly in the field of organic synthesis. In this study, we demonstrate that phosphorus (P)-alloying significantly increases the activity of precious metal NPs for the deoxygenation of sulfoxides into sulfides. In particular, ruthenium phosphide NPs exhibit an excellent catalytic activity and high durability against sulfur-poisoning, outperforming conventional catalysts. Various sulfoxides, including drug intermediates, were deoxygenated to sulfides with excellent yields. Detailed investigations into the structure-activity relationship revealed that P-alloying plays a dual role: it establishes a ligand effect on the electron transfer from Ru to P, facilitating the production of active hydrogen species, and has an ensemble effect on the formation of the Ru-P bond, preventing strong coordination with sulfide products. These effects combine to increase the catalytic performance of ruthenium phosphide NPs. These results demonstrate that P-alloying is an efficient method to improve the metal NP catalysis for diverse organic synthesis.

Insulin signaling in clock neurons regulates sleep in Drosophila.

Sleep relates to numerous biological functions, including metabolism. Both dietary conditions and genes related to metabolism are known to affect sleep behavior. Insulin signaling is well conserved across species including the fruit fly and relates to both metabolism and sleep. However, the neural mechanism of sleep regulation by insulin signaling is poorly understood. Here, we report that insulin signaling in specific neurons regulates sleep in Drosophila melanogaster. We analyzed the sleep behavior of flies with the mutation in insulin-like ligands expressed in the brain and found that three insulin-like ligands participate in sleep regulation with some redundancy. We next used 21 Gal4 drivers to express a dominant-negative form of the insulin receptor (InR DN) in various neurons including circadian clock neurons, which express the clock gene, and the pars intercerebralis (PI). Inhibition of insulin signaling in the anterior dorsal neuron group 1 (DN1a) decreased sleep. Additionally, the same manipulation in PI also decreased sleep. Pan-neuronal induced expression of InR DN also decreased sleep. These results suggested that insulin signaling in DN1a and PI regulates sleep.

Single-Crystal Cobalt Phosphide Nanorods as a High-Performance Catalyst for Reductive Amination of Carbonyl Compounds.

The development of metal phosphide catalysts for organic synthesis is still in its early stages. Herein, we report the successful synthesis of single-crystal cobalt phosphide nanorods (Co2P NRs) containing coordinatively unsaturated Co-Co active sites, which serve as a new class of air-stable, highly active, and reusable heterogeneous catalysts for the reductive amination of carbonyl compounds. The Co2P NR catalyst showed high activity for the transformation of a broad range of carbonyl compounds to their corresponding primary amines using an aqueous ammonia solution or ammonium acetate as a green amination reagent at 1 bar of H2 pressure; these conditions are far milder than previously reported. The air stability and high activity of the Co2P NRs is noteworthy, as conventional Co catalysts are air-sensitive (pyrophorous) and show no activity for this transformation under mild conditions. P-alloying is therefore of considerable importance for nanoengineering air-stable and highly active non-noble-metal catalysts for organic synthesis.

A nickel phosphide nanoalloy catalyst for the C-3 alkylation of oxindoles with alcohols.

Although transition metal phosphides are well studied as electrocatalysts and hydrotreating catalysts, the application of metal phosphides in organic synthesis is rare, and cooperative catalysis between metal phosphides and supports remains unexplored. Herein, we report that a cerium dioxide-supported nickel phosphide nanoalloy (nano-Ni2P/CeO2) efficiently promoted the C-3 alkylation of oxindoles with alcohols without any additives through the borrowing hydrogen methodology. Oxindoles were alkylated with various alcohols to provide the corresponding C-3 alkylated oxindoles in high yields. This is the first catalytic system for the C-3 alkylation of oxindoles with alcohols using a non-precious metal-based heterogeneous catalyst. The catalytic activity of nano-Ni2P/CeO2 was comparable to that reported for precious metal-based catalysts. Moreover, nano-Ni2P/CeO2 was easily recoverable and reusable without any significant loss of activity. Control experiments revealed that the Ni2P nanoalloy and the CeO2 support functioned cooperatively, leading to a high catalytic performance.

A copper nitride catalyst for the efficient hydroxylation of aryl halides under ligand-free conditions.

Copper nitride (Cu3N) was used as a heterogeneous catalyst for the hydroxylation of aryl halides under ligand-free conditions. The cubic Cu3N nanoparticles showed high catalytic activity, comparable to those of conventional Cu catalysts with nitrogen ligands, demonstrating that the nitrogen atoms in Cu3N act as functional ligands that promote hydroxylation.

Hydrogen Production from Methanol-Water Mixture over Immobilized Iridium Complex Catalysts in Vapor-Phase Flow Reaction.

Invited for this month's cover is the group of Shinji Inagaki from Toyota Central R&D Laboratories Inc. and Ken-ichi Fujita from Kyoto University. The image shows iridium complexes immobilized on the channel walls of periodic mesoporous organosilica, which catalyze the dehydrogenation of a methanol-water mixture to produce hydrogen and carbon dioxide. The Full Paper itself is available at 10.1002/cssc.202002557.

Human amnion-derived mesenchymal stem cells attenuate xenogeneic graft-versus-host disease by preventing T cell activation and proliferation.

Acute graft-versus-host disease (GVHD) is characterized by severe tissue damage that is a life-threatening complication of allogeneic hematopoietic stem cell transplantation. Due to their immunosuppressive properties, mesenchymal stem cells (MSC) have been increasingly examined for the treatment of immune-related diseases. We aimed to assess the immunosuppressive effects of human amnion-derived MSC (AMSC) in a xenogeneic GVHD NOD/Shi-scid IL2rγnull mouse model using human peripheral blood mononuclear cells (PBMC). Additionally, we used human bone marrow-derived MSC (BMSC) as comparative controls to determine differences in immunomodulatory functions depending on the MSC origin. Administration of AMSC significantly prolonged survival, and reduced human tumor necrosis factor-α (TNF-α) concentration and percentage of programmed cell death protein-1 receptor (PD-1)+CD8+ T cell populations compared with in GVHD control mice. Furthermore, colonic inflammation score and percentage of human CD8+ T cell populations in AMSC-treated mice were significantly lower than in GVHD control and BMSC-treated mice. Interestingly, gene expression and protein secretion of the PD-1 ligands were higher in AMSC than in BMSC. These findings are the first to demonstrate that AMSC exhibit marked immunosuppression and delay acute GVHD progression by preventing T cell activation and proliferation via the PD-1 pathway.

Hydrogen Production from Methanol-Water Mixture over Immobilized Iridium Complex Catalysts in Vapor-Phase Flow Reaction.

CO-free hydrogen production from methanol and water by using transition metal complex catalysts has attracted increasing attention. However, liquid-phase batch reactions using homogeneous catalysts are impractical for large-scale operations, owing to the consumption of bases and the use of organic solvents or additives. This study concerns a novel method for continuous hydrogen production from a simple methanol-water solution under vapor-phase flow. The reaction is catalyzed by an anionic iridium bipyridonate (Ir-bpyd) complex immobilized on a periodic mesoporous organosilica. The liquid-phase batch reaction using homogeneous anionic Ir-bpyd complex is immediately deactivated, owing to CO2 generation, whereas no catalyst deactivation is observed in the vapor-phase flow reaction because CO2 is smoothly removed from the catalyst bed, enabling continuous hydrogen production without the addition of a base. Thus, the critical problems pertaining to homogeneous catalysts are overcome.