Teruo Hayashi

Bio: Teruo Hayashi is an academic researcher from National Institute on Drug Abuse. The author has contributed to research in topics: Endoplasmic reticulum & Sigma-1 receptor. The author has an hindex of 28, co-authored 38 publications receiving 5320 citations. Previous affiliations of Teruo Hayashi include United States Department of Health and Human Services & National Institutes of Health.

Regulating ankyrin dynamics: Roles of sigma-1 receptors

Abstract: Ankyrin is a cytoskeletal adaptor protein that controls important cellular functions, including Ca(2+) efflux at inositol 1,4,5-trisphosphate receptors (IP(3)R) on the endoplasmic reticulum. The present study found that sigma-1 receptors (Sig-1R), unique endoplasmic reticulum proteins that bind certain steroids, neuroleptics, and psychotropic drugs, form a trimeric complex with ankyrin B and IP(3)R type 3 (IP(3)R-3) in NG-108 cells. The trimeric complex could be coimmunoprecipitated by antibodies against any of the three proteins. Sig-1R agonists such as pregnenolone sulfate and cocaine caused the dissociation of an ankyrin B isoform (ANK 220) from IP(3)R-3. This effect caused by Sig-1R agonists was blocked by a Sig-1R antagonist. The degree of dissociation of ANK 220 from IP(3)R-3 caused by Sig-1R ligands correlates excellently with the ligands' efficacies in potentiating the bradykinin-induced increase in cytosolic free Ca(2+) concentration. Immunocytohistochemistry showed that Sig-1R, ankyrin B, and IP(3)R-3 are colocalized in NG-108 cells in perinuclear areas and in regions of cell-to-cell communication. These results suggest that Sig-1R and associated ligands may play important roles in cells by controlling the function of cytoskeletal proteins and that the Sig-1R/ANK220/IP(3)R-3 complex regulating Ca(2+) signaling may represent a site of action for neurosteroids and cocaine.

Ca(2+) signaling via sigma(1)-receptors: novel regulatory mechanism affecting intracellular Ca(2+) concentration.

Abstract: The sigma(1)-receptor is a one-transmembrane endoplasmic reticulum protein that binds neurosteroids and dextrorotatory benzomorphans. The roles of sigma(1)-receptors in regulating intracellular Ca(2+) in NG108 cells were examined in this study. sigma(1)-Ligands pregnenolone sulfate, (+)-pentazocine, and 2-(4-morpholino)ethyl-1-phenylcyclohexane-1-carboxylate hydrochloride modulate Ca(2+) signaling in NG108 cells via two modes of action. First, nanomolar concentrations of the ligands, without effect by themselves, potentiated the bradykinin-induced increase of the cytosolic free Ca(2+) concentration in a bell-shaped manner. This effect of sigma(1)-ligands was unaffected by depletion of Ca(2+) from perfusion buffer and was blocked by a 21-mer antisense oligodeoxynucleotide against the cloned sigma(1)-receptors. Second, after the cells were depleted of the endoplasmic reticulum Ca(2+) stores, the depolarization (75 mM KCl)-induced increase in cytosolic free Ca(2+) was potentiated by 2-(4-morpholino)ethyl-1-phenylcyclohexane-1-carboxylate hydrochloride, whereas it was inhibited by pregnenolone sulfate and (+)-pentazocine. These effects, albeit opposite in direction, were blocked by both the 21-mer antisense oligodeoxynucleotide and pertussis toxin. Western blotting indicates that sigma(1)-receptors are increased on the plasma membrane and the nuclear membrane in the presence of sigma(1)-ligand. These results suggest that Ca(2+) signaling via sigma(1)-receptors may represent a novel mechanism that affects intracellular Ca(2+) concentrations.

A role for mitochondria in NLRP3 inflammasome activation

Abstract: An inflammatory response initiated by the NLRP3 inflammasome is triggered by a variety of situations of host 'danger', including infection and metabolic dysregulation. Previous studies suggested that NLRP3 inflammasome activity is negatively regulated by autophagy and positively regulated by reactive oxygen species (ROS) derived from an uncharacterized organelle. Here we show that mitophagy/autophagy blockade leads to the accumulation of damaged, ROS-generating mitochondria, and this in turn activates the NLRP3 inflammasome. Resting NLRP3 localizes to endoplasmic reticulum structures, whereas on inflammasome activation both NLRP3 and its adaptor ASC redistribute to the perinuclear space where they co-localize with endoplasmic reticulum and mitochondria organelle clusters. Notably, both ROS generation and inflammasome activation are suppressed when mitochondrial activity is dysregulated by inhibition of the voltage-dependent anion channel. This indicates that NLRP3 inflammasome senses mitochondrial dysfunction and may explain the frequent association of mitochondrial damage with inflammatory diseases.

A SARS-CoV-2 protein interaction map reveals targets for drug repurposing.

Abstract: A newly described coronavirus named severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), which is the causative agent of coronavirus disease 2019 (COVID-19), has infected over 2.3 million people, led to the death of more than 160,000 individuals and caused worldwide social and economic disruption1,2. There are no antiviral drugs with proven clinical efficacy for the treatment of COVID-19, nor are there any vaccines that prevent infection with SARS-CoV-2, and efforts to develop drugs and vaccines are hampered by the limited knowledge of the molecular details of how SARS-CoV-2 infects cells. Here we cloned, tagged and expressed 26 of the 29 SARS-CoV-2 proteins in human cells and identified the human proteins that physically associated with each of the SARS-CoV-2 proteins using affinity-purification mass spectrometry, identifying 332 high-confidence protein–protein interactions between SARS-CoV-2 and human proteins. Among these, we identify 66 druggable human proteins or host factors targeted by 69 compounds (of which, 29 drugs are approved by the US Food and Drug Administration, 12 are in clinical trials and 28 are preclinical compounds). We screened a subset of these in multiple viral assays and found two sets of pharmacological agents that displayed antiviral activity: inhibitors of mRNA translation and predicted regulators of the sigma-1 and sigma-2 receptors. Further studies of these host-factor-targeting agents, including their combination with drugs that directly target viral enzymes, could lead to a therapeutic regimen to treat COVID-19. A human–SARS-CoV-2 protein interaction map highlights cellular processes that are hijacked by the virus and that can be targeted by existing drugs, including inhibitors of mRNA translation and predicted regulators of the sigma receptors.

Physiology of Microglia

Abstract: Microglial cells are the resident macrophages in the central nervous system. These cells of mesodermal/mesenchymal origin migrate into all regions of the central nervous system, disseminate through the brain parenchyma, and acquire a specific ramified morphological phenotype termed "resting microglia." Recent studies indicate that even in the normal brain, microglia have highly motile processes by which they scan their territorial domains. By a large number of signaling pathways they can communicate with macroglial cells and neurons and with cells of the immune system. Likewise, microglial cells express receptors classically described for brain-specific communication such as neurotransmitter receptors and those first discovered as immune cell-specific such as for cytokines. Microglial cells are considered the most susceptible sensors of brain pathology. Upon any detection of signs for brain lesions or nervous system dysfunction, microglial cells undergo a complex, multistage activation process that converts them into the "activated microglial cell." This cell form has the capacity to release a large number of substances that can act detrimental or beneficial for the surrounding cells. Activated microglial cells can migrate to the site of injury, proliferate, and phagocytose cells and cellular compartments.

STING regulates intracellular DNA-mediated, type I interferon-dependent innate immunity

Abstract: The innate immune system is critical for the early detection of invading pathogens and for initiating cellular host defence countermeasures, which include the production of type I interferon (IFN). However, little is known about how the innate immune system is galvanized to respond to DNA-based microbes. Here we show that STING (stimulator of interferon genes) is critical for the induction of IFN by non-CpG intracellular DNA species produced by various DNA pathogens after infection. Murine embryonic fibroblasts, as well as antigen presenting cells such as macrophages and dendritic cells (exposed to intracellular B-form DNA, the DNA virus herpes simplex virus 1 (HSV-1) or bacteria Listeria monocytogenes), were found to require STING to initiate effective IFN production. Accordingly, Sting-knockout mice were susceptible to lethal infection after exposure to HSV-1. The importance of STING in facilitating DNA-mediated innate immune responses was further evident because cytotoxic T-cell responses induced by plasmid DNA vaccination were reduced in Sting-deficient animals. In the presence of intracellular DNA, STING relocalized with TANK-binding kinase 1 (TBK1) from the endoplasmic reticulum to perinuclear vesicles containing the exocyst component Sec5 (also known as EXOC2). Collectively, our studies indicate that STING is essential for host defence against DNA pathogens such as HSV-1 and facilitates the adjuvant activity of DNA-based vaccines.