Two distinct modes of action of molecular glues in the plant hormone co-receptor COI1-JAZ system.

The plant hormone (3R, 7S)-jasmonoyl-L-isoleucine ((3R, 7S)-JA-Ile) is perceived by the COI1-JAZ co-receptor in Arabidopsis thaliana, leading to the activation of gene expression for plant defense responses, growth, development, and other processes. Therefore, understanding the interaction between the COI1-JAZ co-receptor and its ligands is essential for the development of COI1-JAZ agonists and antagonists as potent chemical tools for regulating (3R, 7S)-JA-Ile signaling. This study demonstrated that COI1-JAZ has two independent modes of ligand perception using a differential scanning fluorimetry (DSF) assay. (3R, 7S)-JA-Ile is perceived through a one-step model in which (3R, 7S)-JA-Ile causes protein-protein interaction between COI1 and JAZ. In contrast, coronatine (COR), a mimic of (3R, 7S)-JA-Ile, is perceived through a two-step model in which COR is first perceived by COI1 and then recruits JAZ to form the COI1-COR-JAZ complex. Our results demonstrate two distinct modes of action of molecular glues causing protein-protein interactions.

Difference in the ligand affinity among redundant plant hormone receptors of rice OsCOI1a/1b/2-OsJAZs.

(3R, 7S)-jasmonoyl-L-isoleucine (JA-Ile) is a lipid-derived plant hormone that regulates plant responses, including biotic/abiotic stress adaptation. In the plant cells, JA-Ile is perceived by COI1-JAZ co-receptor by causing protein-protein interaction between COI1 and JAZ proteins to trigger gene expressions. In this study, we focused on Oryza sativa, a model monocot and an important crop, with 45 possible OsCOI-OsJAZ co-receptor pairs composed of three OsCOI homologs (OsCOI1a, OsCOI1b, and OsCOI2) and 15 OsJAZ homologs. We performed fluorescein anisotropy and pull-down assays to examine the affinity between JA-Ile and OsCOI1a/1b/2-OsJAZ1-15 co-receptor pairs. The results revealed a remarkable difference in the modes of ligand perception by OsCOI1a/1b and OsCOI2. Recently, the unique function of OsCOI2 in some of the JA-responses were revealed. Our current results will lead to the possible development of OsCOI2-selective synthetic ligand.

Antidepressants induce toxicity in human placental BeWo cells.

Selective serotonin reuptake inhibitors (SSRIs), serotonin and noradrenaline reuptake inhibitors (SNRIs), and noradrenergic and specific serotonergic antidepressants (NaSSAs) are broadly used for the treatment of depression. Depression is one of the most common psychiatric disorders in pregnant women and SSRIs are commonly prescribed for depression during pregnancy. The placenta regulates the transport of nutrients and oxygen between the maternal and fetal circulation, and is essential for the survival and growth of the fetus. The present study investigated the effects of antidepressants on human placental BeWo cells. BeWo cell viability was significantly decreased following exposure to sertraline (SSRI), paroxetine (SSRI), fluvoxamine (SSRI), and duloxetine (SNRI), whereas escitalopram (SSRI), venlafaxine (SNRI), and mirtazapine (NaSSA) showed little or no effects. Extracellular lactate dehydrogenase activity was increased by sertraline, paroxetine, fluvoxamine, and duloxetine, indicating toxicity to the cells. Sertraline increased the production of cellular reactive oxygen species (ROS) and decreased the mitochondrial membrane potential. Sertraline decreased the cellular ATP content in a time and concentration-dependent manner. Caspase-3/7 activity and apoptotic cells, detected using the phosphatidylserine-specific fluorescent probe Apotracker Green, were increased by sertraline. Our findings suggest that antidepressants, such as sertraline, paroxetine, fluvoxamine, and duloxetine, induce toxicity in human placental BeWo cells. Sertraline may induce ROS-dependent apoptosis in human placental cells. These results are useful for further studies to determine the optimal dosage of antidepressants for pregnant women.

Characterization of a TNFR2-Selective Agonistic TNF-α Mutant and Its Derivatives as an Optimal Regulatory T Cell Expander.

Regulatory T cells (Tregs) are a subpopulation of lymphocytes that play a role in suppressing and regulating immune responses. Recently, it was suggested that controlling the functions and activities of Tregs might be applicable to the treatment of human diseases such as autoimmune diseases, organ transplant rejection, and graft-versus-host disease. TNF receptor type 2 (TNFR2) is a target molecule that modulates Treg functions. In this study, we investigated the role of TNFR2 signaling in the differentiation and activation of mouse Tregs. We previously reported the generation of a TNFR2-selective agonist TNF mutant, termed R2agoTNF, by using our unique cytokine modification method based on phage display. R2agoTNF activates cell signaling via mouse TNFR2. In this study, we evaluated the efficacy of R2agoTNF for the proliferation and activation of Tregs in mice. R2agoTNF expanded and activated mouse CD4+CD25+ Tregs ex vivo. The structural optimization of R2agoTNF by internal cross-linking or IgG-Fc fusion selectively and effectively enhanced Treg expansion in vivo. Furthermore, the IgG-Fc fusion protein suppressed skin-contact hypersensitivity reactions in mice. TNFR2 agonists are expected to be new Treg expanders.

[The development, reliability, and validity of a Japanese version of the MBI-ES].

In this study, we developed a Japanese version of the Maslach Burnout Inventory - Educators Survey (MBI-ES). We also examined the reliability and validity of the scale, based on data from Japanese schoolteachers. Because some items related to depersonalization showed a floor effect, the reliability of the MBI-ES was evaluated using item response theory (IRT), which can evaluate the difficulty of the items. The IRT analysis showed that scores of emotional exhaustion and personal accomplishment had high reliabilities among the wide range of distribution of the latent scores around the means. However, the reliability of the depersonalization items was estimated to be moderate when it was implemented among highly depersonalized teachers, whereas the reliability was lower for relatively healthy teachers. Correlations with the General Health Questionnaire, frequency of emotional labor, and job satisfaction were mostly consistent with previous research and the current theory of burnout, supporting the high validity of the Japanese version of the MBI-ES.