Neuroinflammation, a hallmark of neurodegenerative diseases, is associated with neuronal cell loss and cognitive dysfunction. Monoacylglycerol lipase (MAGL) is involved in neuroinflammation in the brain via the degradation of endocannabinoid 2-arachidonoylglycerol to arachidonic acid, a precursor of some eicosanoids; therefore, MAGL inhibitors are expected to have anti-inflammatory effects. We recently developed a reversible, selective, central nervous system penetrant, and orally available MAGL inhibitor, compound 4f.
View Article and Find Full Text PDFBackground And Aims: Anti-angiogenic therapies prolong patient survival in some malignancies but not glioblastoma. We focused on the relationship between the differentiation of glioma stem like cells (GSCs) into tumor derived endothelial cells (TDECs) and, anti-angiogenic therapy resistance. Especially we aimed to elucidate the mechanisms of drug resistance of TDECs to anti-angiogenic inhibitors and identify novel anti-angiogenic drugs with clinical applications.
View Article and Find Full Text PDFThe beta-glucocerebrosidase (GBA1) gene encodes the lysosomal beta-glucocerebrosidase (GCase) that metabolizes the lipids glucosylceramide (GlcCer) and glucosylsphingosine (GlcSph). Biallelic loss-of-function mutations in GBA1 such as L444P cause Gaucher disease (GD), which is the most prevalent lysosomal storage disease and is histopathologically characterized by abnormal accumulation of the GCase substrates GlcCer and GlcSph. GD with neurological symptoms is associated with severe mutations in the GBA1 gene, most of which cause impairment in the process of GCase trafficking to lysosomes.
View Article and Find Full Text PDFα-Synuclein accumulates in Lewy bodies, and this accumulation is a pathological hallmark of Parkinson's disease (PD). Previous studies have indicated a causal role of α-synuclein in the pathogenesis of PD. However, the molecular and cellular mechanisms of α-synuclein toxicity remain elusive.
View Article and Find Full Text PDFMale sexual activity reduces the level of depression through oxytocin (OT) release within the brain. In this study, we showed that male mating behavior reduces depression-like behavior through OT-induced cAMP response element binding protein (CREB) signaling in the hippocampus. Moreover, we showed that mating behavior in wild-type (WT) male mice increased CREB phosphorylation in hippocampus, whereas that OT receptor knockout (OTR KO) male mice had no effect on CREB phosphorylation.
View Article and Find Full Text PDFThe hyperpolarization-activated cyclic nucleotide-gated 4 (HCN4) channel underlies the pacemaker currents, called "If," in sinoatrial nodes (SANs), which regulate heart rhythm. Some HCN4 blockers such as ivabradine have been extensively studied for treating various heart diseases. Studies have shown that these blockers have diverse state dependencies and binding sites, suggesting the existence of potential chemical and functional diversity among HCN4 blockers.
View Article and Find Full Text PDFBoron neutron capture therapy (BNCT) is a tumor selective therapy, the effectiveness of which depends on sufficient B delivery to and accumulation in tumors. In this study, we used self-assembling A6K peptide nanotubes as boron carriers and prepared new boron agents by simple mixing of A6K and BSH. BSH has been used to treat malignant glioma patients in clinical trials and its drug safety and availability have been confirmed; however, its contribution to BNCT efficacy is low.
View Article and Find Full Text PDFPhosphodiesterase type 2A (PDE2A) has received considerable interest as a molecular target for treating central nervous system diseases that affect memory, learning, and cognition. In this paper, the authors present the discovery of small molecules that have a novel modality of PDE2A inhibition. PDE2A possesses GAF-A and GAF-B domains and is a dual-substrate enzyme capable of hydrolyzing both cGMP and cAMP, and activation occurs through cGMP binding to the GAF-B domain.
View Article and Find Full Text PDFClinical reports show that oxytocin (OT) is related to stress-related disorders such as depression, anxiety disorder, and post-traumatic stress disorder. Two key structures in the brain should be paid special attention with regard to stress regulation, namely, the hypothalamus and the hippocampus. The former is the region for central command for most, if not all, of the major endocrine systems, and the latter takes a key position in the regulation of mood and anxiety.
View Article and Find Full Text PDFLipid nanoparticles (LNPs) are one of the leading technologies for the in vivo delivery of short interfering RNA (siRNA). Cationic lipids are an important component for efficient endosomal escape via membrane fusion followed by release of siRNAs in cytosol where the site of action is located. A high cationic lipid/siRNA charge ratio is usually necessary for maximizing the gene silencing activity of the siRNA-loaded LNPs.
View Article and Find Full Text PDFStress is an adaptive and coordinated response to endogenous or exogenous stressors that pose an unpleasant and aversive threat to an individual's homeostasis and wellbeing. Glucocorticoids, corticosterone (CORT) in rodents and cortisol in humans, are adrenal steroids which are released in response to stressful stimuli. Although they help individuals to cope with stress, their overexposure in animals has been implicated in hippocampal dysfunction and neuronal loss.
View Article and Find Full Text PDFLipid nanoparticles (LNPs) are the leading technology for delivering short interfering RNA (siRNA) in vivo. While numerous attempts to improve the efficiency of siRNA delivery have been reported, only a few studies of the mechanism of LNP-mediated toxicity and attempts to develop safe LNPs in vivo have been reported, in spite of the significance of such systems, in the light of treatment and clinical applications. We herein report on the elucidation of the mechanism of hepatotoxicity following the intravenous injection of a high dose of hepatotropic LNPs.
View Article and Find Full Text PDFPoly(2-hydroxyethyl methacrylate) (PHEMA) was synthesized using ultrasonic irradiation without any chemical initiator. The effect of the ultrasonic power intensity on the time course of the conversion to polymer, the number average molecular weight, and the polydispersity were investigated in order to synthesize a polymer with a low molecular weight distribution (i.e.
View Article and Find Full Text PDFGlioblastoma multiforme (GBM) is the most common malignant brain tumor with a median survival time about one year. Invasion of GBM cells into normal brain is the major cause of poor prognosis and requires dynamic reorganization of the actin cytoskeleton, which includes lamellipodial protrusions, focal adhesions, and stress fibers at the leading edge of GBM. Therefore, we hypothesized that inhibitors of actin polymerization can suppress GBM migration and invasion.
View Article and Find Full Text PDFMacrophages are key contributors to various inflammatory diseases. Therefore, the development of an efficient in vivo short interference RNA (siRNA) system that can be delivered to macrophages represents a novel treatment strategy for addressing these disorders. It was recently revealed that peritoneal macrophages (PEMs) are involved in several diseases including ovarian cancer, and are now recognized as a promising drug target.
View Article and Find Full Text PDFHedgehog (Hh) signaling critical for development, differentiation, and cell growth is involved in several cancers, including medulloblastoma and basal cell carcinoma. Although antagonism of the smoothened receptor (SMO), which mediates Hh signaling, is an attractive therapeutic target, a drug-resistant mutation in SMO (SMO-D473H) was identified in a clinical trial of the approved drug vismodegib. TAK-441 potently inhibits SMO-D473H, unlike vismodegib and another SMO antagonist, cyclopamine, whereas the differences in binding modes between these antagonists remain unknown.
View Article and Find Full Text PDFBackground Information: Cortactin contributes to growth cone morphogenesis by forming with dynamin, ring-shaped complexes that mechanically bundle and stabilise F-actin. However, the regulatory mechanism of cortactin action is poorly understood.
Results: Immunofluorescence microscopy revealed that protein kinase C (PKC) α colocalises with cortactin at growth cone filopodia in SH-SY5Y neuroblastoma cells.
Glioblastoma, a malignant brain tumor with poor disease outcomes, is managed in modern medicine by multimodality therapy. Boron neutron capture therapy (BNCT) is an encouraging treatment under clinical investigation. In malignant cells, BNCT consists of two major factors: neutron radiation and boron uptake.
View Article and Find Full Text PDFA 61-year-old man was diagnosed with lung squamous cell carcinoma in the lower lobe of the right lung. He had received first-line chemotherapy consisting of cisplatin and docetaxel (DTX); however, an allergic/hypersensitivity reaction occurred shortly after administration of the second course of DTX. Thirty-nine months later, he received nanoparticle albumin-bound paclitaxel (nab-PTX) as sixth-line chemotherapy, which did not produce a hypersensitivity reaction.
View Article and Find Full Text PDFTransfer RNAs (tRNAs) contain a wide variety of posttranscriptional modifications that are important for accurate decoding. Mammalian mitochondrial tRNAs (mt-tRNAs) are modified by nuclear-encoded tRNA-modifying enzymes; however, the physiological roles of these modifications remain largely unknown. In this study, we report that Cdk5 regulatory subunit-associated protein 1 (Cdk5rap1) is responsible for 2-methylthio (ms(2)) modifications of mammalian mt-tRNAs for Ser(UCN), Phe, Tyr, and Trp codons.
View Article and Find Full Text PDFIn the course of our study on selective nonsteroidal mineralocorticoid receptor (MR) antagonists, a series of novel benzoxazine derivatives possessing an azole ring as the core scaffold was designed for the purpose of attenuating the partial agonistic activity of the previously reported dihydropyrrol-2-one derivatives. Screening of alternative azole rings identified 1,3-dimethyl pyrazole 6a as a lead compound with reduced partial agonistic activity. Subsequent replacement of the 1-methyl group of the pyrazole ring with larger lipophilic side chains or polar side chains targeting Arg817 and Gln776 increased MR binding activity while maintaining the agonistic response at the lower level.
View Article and Find Full Text PDFObjective: Developmental disorders including cognitive deficit, hyperkinetic disorder, and autistic behaviors are frequently comorbid in epileptic patients with SCN1A mutations. However, the mechanisms underlying these developmental disorders are poorly understood and treatments are currently unavailable. Using a rodent model with an Scn1a mutation, we aimed to elucidate the pathophysiologic basis and potential therapeutic treatments for developmental disorders stemming from Scn1a mutations.
View Article and Find Full Text PDFTopical therapy is the most favored form of treatment for whitening against hyper-pigmentation and sunburn because it lends itself to self-administration, patient compliance and an absence of systemic adverse effects. However, high-molecular-weight, hydrophilic chemicals are difficult to use as transdermal delivery drugs and the use of topical drugs has been highly limited. There are now many potent tyrosinase inhibitors, for example, sulfite or kojic acid, but the efficacy of their skin transduction remains a big problem.
View Article and Find Full Text PDFNew anti-cancer therapy with boron neutron capture therapy (BNCT) is based on the nuclear reaction of boron-10 with neutron irradiation. The median survival of BNCT patients with glioblastoma was almost twice as long as those receiving standard therapy in a Japanese BNCT clinical trial. In this clinical trial, two boron compounds, BPA (boronophenylalanine) and BSH (sodium borocaptate), were used for BNCT.
View Article and Find Full Text PDFA series of piperazine ureas were designed, synthesized, and evaluated for their potential as novel orally efficacious fatty acid amide hydrolase (FAAH) inhibitors for the treatment of neuropathic and inflammatory pain. We carried out an optimization study of compound 5 to improve its in vitro FAAH inhibitory activity, and identified the 2-pyrimidinylpiperazine derivative 21d with potent inhibitory activity, favorable DMPK profile and brain permeability. Compound 21d showed robust and dose-dependent analgesic efficacy in animal models of both neuropathic and inflammatory pain.
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