Downregulation of nuclear receptor-binding SET domain protein 1 induces proinflammatory cytokine expression via mitogen-activated protein kinase pathways in U87MG cells.

Haploinsufficiency of the nuclear receptor binding SET domain-containing protein 1 gene (NSD1) leads to a neurodevelopmental disorder known as Sotos syndrome (SOTOS). This study investigated the effects of NSD1 knockdown in glial cells. U87MG glioma cells were transfected with siRNA targeting NSD1, which resulted in morphological changes characteristic of activated astrocytes. These activated phenotypes were accompanied by specific activation of mitogen-activated protein kinase (MAPK) signaling pathways, particularly those mediated by p38 MAPK and c-Jun N-terminal kinase (JNK). Transcriptome analysis showed increased expression of proinflammatory cytokine genes, particularly interleukin (IL)-1α, IL-1ß, and IL-6, following NSD1 knockdown. Treatment with MAPK inhibitors significantly reduced the cytokine induction caused by NSD1 knockdown, with the p38 MAPK inhibitor being more effective than the JNK inhibitor. These findings provide new insights into the role of NSD1 loss in neurological dysfunctions associated with SOTOS.

NSD Overexpression in the Fat Body Increases Antimicrobial Peptide Production by the Immune Deficiency Pathway in Drosophila.

Nuclear receptor-binding SET domain-containing protein 1 (NSD1) inactivation in tumor cells contributes to an immune-cold phenotype, indicating its potential association with immune disturbances. Drosophila NSD is a homolog of the human NSD1. Thus, in this study, we investigated the effect of NSD overexpression in the fat body, the central organ involved in Drosophila immune responses. Upon ectopic expression of NSD in the fat body, the mRNA levels of antimicrobial peptides increased. Using reporter constructs containing deletions of various NF-κB sites in the Attacin-A (AttA) promoter, we found that transcriptional activation by NSD is mainly mediated via the IMD pathway by activating Relish. Since the IMD pathway is required to resist Gram-negative bacterial infections, we further examined the effect of fat body-specific NSD overexpression on Drosophila immune defenses. Upon oral ingestion of Gram-negative Pseudomonas entomophila, the survival rate of the NSD-overexpressing larvae was higher than that of the wild type, suggesting a positive role of NSD in immune responses. Taken together, these results suggest the association of NSD with the IMD pathway and is thus expected to contribute to the elucidation of the molecular mechanisms of immune malfunction in various NSD1-associated human diseases.

Submerged leaves of live indoor foliage plants adsorb H1N1 influenza virus from suspension.

Control of hazardous indoor particles using plants has attracted interest due to the increasing worldwide air pollution and spread of pandemic-causing viruses. However, the interaction between human pathogenic viruses (HPVs) and live plants has not been examined largely due to issues in detecting tiny amounts of infectious viruses in a carrier (such as an aerosol) and the lack of suitable examination methods. In this study, as a novel evaluation method, the effect of submerged leaves of live plants on HPVs in water was examined, using the H1N1 influenza virus as a model. Selected plant foliage of a live plant was immersed in a small bag containing HPV water suspension. In an initial screening test, the activities of 20 different plant species on the virus suspension were evaluated using a rapid virus detection kit. Ten plant species had the capability to decrease virus concentrations in the water suspension within 72 h. Among the experimental plant species, Epipremnum aureum showed the highest virus decreasing characteristics when examined using both the kit and quantitative real time polymerase chain reaction. The capacity of immersed leaf of live E. aureum to decrease viral content was enhanced when the plant-containing pot was electrically grounded to the earth (approximately 70% decrease in virus concentration). The foliage sample analysis showed that virus adsorption to the plant foliage surface could be the major reason for the decrease in the suspension. These results suggest that the proposed method can be applied to select plants to further investigate plant-HPV interactions.

Association of Elevated Expression Levels of COL4A1 in Stromal Cells with an Immunosuppressive Tumor Microenvironment in Low-Grade Glioma, Pancreatic Adenocarcinoma, Skin Cutaneous Melanoma, and Stomach Adenocarcinoma.

Aberrant expression of collagen type IV alpha chain 1 (COL4A1) can influence tumor cell behavior. To examine the association of COL4A1 expression in the tumor microenvironment (TME) with tumor progression, we performed bioinformatics analyses of The Cancer Genome Atlas RNA sequencing and RNA microarray datasets available in public databases and identified upregulated COL4A1 expression in most examined tumor types compared to their normal counterparts. The elevated expression of COL4A1 was correlated with low survival rates of patients with low-grade glioma, pancreatic adenocarcinoma, skin cutaneous melanoma, and stomach adenocarcinoma, thus suggesting its potential use as a biomarker for the poor prognosis of these tumors. However, COL4A1 was mostly expressed in adjacent stromal cells, such as cancer-associated fibroblasts (CAFs) and endothelial cells. Additionally, COL4A1 expression was highly correlated with the signatures of CAFs and endothelial cells in all four tumor types. The expression of marker genes for the infiltration of pro-tumoral immune cells, such as Treg, M2, and TAM, and those of immunosuppressive cytokines exhibited very strong positive correlations with COL4A1 expression. Collectively, our data suggest that COL4A1 overexpression in stromal cells may be a potential regulator of tumor-supporting TME composition associated with poor prognosis.

The function of Scox in glial cells is essential for locomotive ability in Drosophila.

Synthesis of cytochrome c oxidase (Scox) is a Drosophila homolog of human SCO2 encoding a metallochaperone that transports copper to cytochrome c, and is an essential protein for the assembly of cytochrome c oxidase in the mitochondrial respiratory chain complex. SCO2 is highly conserved in a wide variety of species across prokaryotes and eukaryotes, and mutations in SCO2 are known to cause mitochondrial diseases such as fatal infantile cardioencephalomyopathy, Leigh syndrome, and Charcot-Marie-Tooth disease, a neurodegenerative disorder. These diseases have a common symptom of locomotive dysfunction. However, the mechanisms of their pathogenesis remain unknown, and no fundamental medications or therapies have been established for these diseases. In this study, we demonstrated that the glial cell-specific knockdown of Scox perturbs the mitochondrial morphology and function, and locomotive behavior in Drosophila. In addition, the morphology and function of synapses were impaired in the glial cell-specific Scox knockdown. Furthermore, Scox knockdown in ensheathing glia, one type of glial cell in Drosophila, resulted in larval and adult locomotive dysfunction. This study suggests that the impairment of Scox in glial cells in the Drosophila CNS mimics the pathological phenotypes observed by mutations in the SCO2 gene in humans.

Drosophila NSD deletion induces developmental anomalies similar to those seen in Sotos syndrome 1 patients.

BACKGROUND: Haploinsufficiency of the human nuclear receptor binding suppressor of variegation 3-9, enhancer of zeste, and trithorax (SET) domain 1 (NSD1) gene causes a developmental disorder called Sotos syndrome 1 (SOTOS1), which is associated with overgrowth and macrocephaly. NSD family proteins encoding histone H3 lysine 36 (H3K36) methyltransferases are conserved in many species, and Drosophila has a single NSD homolog gene, NSD. OBJECTIVE: To gain insight into the biological functions of NSD1 deficiency in the developmental anomalies seen in SOTOS1 patients using an NSD-deleted Drosophila mutant. METHODS: We deleted Drosophila NSD using CRISPR/Cas9-mediated targeted gene knock-out, and analyzed pleiotropic phenotypes of the homozygous mutant of NSD (NSD-/-) at various developmental stages to understand the roles of NSD in Drosophila. RESULTS: The site-specific NSD deletion was confirmed in the mutant. The H3K36 di-methylation levels were dramatically decreased in the NSD-/- fly. Compared with the control, the NSD-/- fly displayed an increase in the body size of larvae, similar to the childhood overgrowth phenotype of SOTOS1 patients. Although the NSD mutant flies survived to adulthood, their fecundity was dramatically decreased. Furthermore, the NSD-/- fly showed neurological dysfunctions, such as lower memory performance and motor defects, and a diminished extracellular signal-regulated kinase (ERK) activity. CONCLUSIONS: The NSD-deleted Drosophila phenotype resembles many of the phenotypes of SOTOS1 patients, such as learning disability, deregulated ERK signaling, and overgrowth; thus, this mutant fly is a relevant model organism to study various SOTOS1 phenotypes.

Drosophila models to study causative genes for human rare intractable neurological diseases.

Drosophila is emerging as a convenient model for investigating human diseases. Functional homologues of almost 75% of human disease-related genes are found in Drosophila. Amyotrophic lateral sclerosis (ALS) is a severe neurodegenerative disease that causes defects in motoneurons. Charcot-Marie-Tooth disease (CMT) is one of the most commonly found inherited neuropathies affecting both motor and sensory neurons. No effective therapy has been established for either of these diseases. In this review, after overviewing ALS, Drosophila models targeting several ALS-causing genes, including TDP-43, FUS and Ubiquilin2, are described with their genetic interactants. Then, after overviewing CMT, examples of Drosophila models targeting several CMT-causing genes, including mitochondria-related genes and FIG 4, are also described with their genetic interactants. In addition, we introduce Sotos syndrome caused by mutations in the epigenetic regulator gene NSD1. Lastly, several genes and pathways that commonly interact with ALS- and/or CMT-causing genes are described. In the case of ALS and CMT that have many causative genes, it may be not practical to perform gene therapy for each of the many disease-causing genes. The possible uses of the common genes and pathways as novel diagnosis markers and effective therapeutic targets are discussed.

Linalool Alleviates Aß42-Induced Neurodegeneration via Suppressing ROS Production and Inflammation in Fly and Rat Models of Alzheimer's Disease.

Terpenes are vital metabolites found in various plants and animals and known to be beneficial in the treatment of various diseases. Previously, our group identified terpenes that increased the survival of Alzheimer's disease (AD) model flies expressing human amyloid ß (Aß) and identified linalool as a neuroprotective terpene against Aß toxicity. Linalool is a monoterpene that is commonly present as a constituent in essential oils from aromatic plants and is known to have anti-inflammatory, anticancer, antihyperlipidemia, antibacterial, and neuroprotective properties. Although several studies have shown the beneficial effect of linalool in AD animal models, the mechanisms underlying the beneficial effect of linalool on AD are yet to be elucidated. In the present study, we showed that linalool intake increased the survival of the AD model flies during development in a dose-dependent manner, while the survival of wild-type flies was not affected even at high linalool concentrations. Linalool also decreases Aß-induced apoptosis in eye discs as well as the larval brain. Moreover, linalool intake was found to reduce neurodegeneration in the brain of adult AD model flies. However, linalool did not affect the total amount of Aß42 protein or Aß42 aggregation. Rather, linalool decreased Aß-induced ROS levels, oxidative stress, and inflammatory response in the brains of AD model flies. Furthermore, linalool attenuated the induction of oxidative stress and gliosis by Aß 1-42 treatment in the rat hippocampus. Taken together, our data suggest that linalool exerts its beneficial effects on AD by reducing Aß42-induced oxidative stress and inflammatory reactions.

Drosophila Glia: Models for Human Neurodevelopmental and Neurodegenerative Disorders.

Glial cells are key players in the proper formation and maintenance of the nervous system, thus contributing to neuronal health and disease in humans. However, little is known about the molecular pathways that govern glia-neuron communications in the diseased brain. Drosophila provides a useful in vivo model to explore the conserved molecular details of glial cell biology and their contributions to brain function and disease susceptibility. Herein, we review recent studies that explore glial functions in normal neuronal development, along with Drosophila models that seek to identify the pathological implications of glial defects in the context of various central nervous system disorders.