Establishment of a human cell line stably overexpressing mouse Nip45 and characterization of Nip45 subcellular localization

The nuclear factor of activated T cells, cytoplasmic, calcineurin dependent 2 interacting protein, Nfatc2ip (Nip45), has been implicated as a crucial coordinator of the immune response and of cellular differentiation in humans and mice, and contains SUMO-like domains in its C-terminal region. However, the significance of its N-terminal region and its correlation to the SUMO modification pathway remain largely uncharacterized. In this study, a human cultured cell line was established, in which FLAG-tagged mouse Nip45 (FLAG-mNip45) was stably overexpressed. Under standard, non-stressful conditions, we detected FLAG-mNip45 diffusely distributed in the nucleus. Intriguingly, proteasome inhibition by MG132 caused FLAG-mNip45, together with SUMOylated proteins, to localize in nuclear domains associated with promyelocytic leukemia protein. Finally, using an in vitro binding assay, we showed interaction of the N-terminal region of mNip45 with both free SUMO-3 and SUMO-3 chains, indicating that Nip45 may, in part, exert its function via interaction with SUMO/SUMOylated proteins. Taken together, our study provides novel information on a poorly characterized mammalian protein and suggests that our newly established cell line will be useful for elucidating the physiological role of Nip45.     

Clinical Features and Mortality of COVID-19-Associated Mucormycosis: A Systematic Review and Meta-Analysis

The recent increase of COVID-19-associated mucormycosis (CAM) has been commanding global attention. However, basic epidemiologic characteristics have not firmly been established. In this systematic review and meta-analysis, we sought to determine the clinical manifestations, potential risk factors, and outcomes of CAM. Observational studies reporting CAM were searched with PubMed and EMBASE databases in January 2022. We collected data on comorbidities and treatment for COVID-19, and performed a one-group meta-analysis on the frequency of orbital exenteration procedure and mortality of CAM using a random-effect model. Fifty-one observational studies, including a total of 2,312 patients with proven CAM, were identified. Among the 51 studies, 37 were conducted in India, 8 in Egypt, and 6 in other countries. The most common comorbidity was diabetes mellitus (82%). While 57% required oxygenation, 77% received systemic corticosteroids. Among CAM, 97% were rhino-orbital-cerebral (ROCM), and 2.7% were pulmonary mucormycosis. Usual presentations were headache (54%), periorbital swelling/pain (53%), facial swelling/pain (43%), ophthalmoplegia (42%), proptosis (41%), and nasal discharge/congestion (36%). Regarding the outcomes, orbital exenteration was performed in 17% (95% CI: 12–21%, I²?=?83%) of the COVID-19-associated ROCM patients. The mortality of CAM was 29% (95% CI; 22–36%, I²?=?92%). In conclusion, this systematic review and meta-analysis indicated that the most prevalent type of CAM was ROCM, and most CAM patients had diabetes mellitus and received systemic glucocorticoids. Clinicians in the endemic areas should have a high index of suspicion for this invasive fungal complication of COVID-19 when a diabetic patient who received high-dose systemic glucocorticoids developed rhino-orbital symptoms.

     

Hepatocyte Nuclear Factor 4 Alpha Is a Key Factor Related to Depression and Physiological Homeostasis in the Mouse Brain

Major depressive disorder (MDD) is a common psychiatric disorder that involves marked disabilities in global functioning, anorexia, and severe medical comorbidities. MDD is associated with not only psychological and sociocultural problems, but also pervasive physical dysfunctions such as metabolic, neurobiological and immunological abnormalities. Nevertheless, the mechanisms underlying the interactions between these factors have yet to be determined in detail. The aim of the present study was to identify the molecular mechanisms responsible for the interactions between MDD and dysregulation of physiological homeostasis, including immunological function as well as lipid metabolism, coagulation, and hormonal activity in the brain. We generated depression-like behavior in mice using chronic mild stress (CMS) as a model of depression. We compared the gene expression profiles in the prefrontal cortex (PFC) of CMS and control mice using microarrays. We subsequently categorized genes using two web-based bioinformatics applications: Ingenuity Pathway Analysis and The Database for Annotation, Visualization, and Integrated Discovery. We then confirmed significant group-differences by analyzing mRNA and protein expression levels not only in the PFC, but also in the thalamus and hippocampus. These web tools revealed that hepatocyte nuclear factor 4 alpha (Hnf4a) may exert direct effects on various genes specifically associated with amine synthesis, such as genes involved in serotonin metabolism and related immunological functions. Moreover, these genes may influence lipid metabolism, coagulation, and hormonal activity. We also confirmed the significant effects of Hnf4a on both mRNA and protein expression levels in the brain. These results suggest that Hnf4a may have a critical influence on physiological homeostasis under depressive states, and may be associated with the mechanisms responsible for the interactions between MDD and the dysregulation of physiological homeostasis in humans.     

Horizontal gradient in fish assemblage structures in and around a seagrass habitat: some implications for seagrass habitat conservation

Horizontal gradients in fish assemblage structures in and around a seagrass habitat were evaluated by visual observations. The assemblage structures clearly differed between open microhabitats lacking seagrass, i.e., nearby sand and the area adjoining the outer margin of the seagrass bed (referred to as “outer gap”), and microhabitats with seagrass within the overall seagrass bed, although not differing among the latter microhabitats, including both edge and core portions. Such open microhabitats were found to be not always inferior, but nearly equal to or even sometimes greatly superior in fish species’ diversity and/or abundance to the microhabitats with seagrass. In particular, the outer gap was always ranked first in total species’ number and had outstanding abundance in spring. Similar open microhabitats adjoining seagrass walls facing the sand patch within the seagrass bed (referred to as “inner gap”) in spring were also characterized by higher fish species and individual numbers. The 11 most abundant fishes showed four discrete distribution patterns (three recognized herein and one implied by precedent studies), such contributing to a horizontal gradient in the fish assemblage structure. While no fishes showed a preference for the edge or core of the seagrass bed, group-forming juveniles of several species favored gap microhabitats, suggesting that, in addition to the traditionally recognized edge and core microhabitats, the concept of gap microhabitats should be included in seagrass conservation ecology.     

Identification of the mouse paternally expressed imprinted gene Zdbf2 on chromosome 1 and its imprinted human homolog ZDBF2 on chromosome 2

In mammals, both the maternal and paternal genomes are necessary for normal embryogenesis due to parent-specific epigenetic modification of the genome during gametogenesis, which leads to non-equivalent expression of imprinted genes from the maternal and paternal alleles. In this study, we identified a paternally expressed imprinted gene, Zdbf2, by microarray-based screening using parthenogenetic and normal embryos. Expression analyses showed that Zdbf2 was paternally expressed in various embryonic and adult tissues, except for the placenta and adult testis, which showed biallelic expression of the gene. We also identified a differentially methylated region (DMR) at 10 kb upstream of exon 1 of the Zdbf2 gene and this differential methylation was derived from the germline. Furthermore, we also identified that the human homolog (ZDBF2) of the mouse Zdbf2 gene showed paternal allele-specific expression in human lymphocytes but not in the human placenta. Thus, our findings defined mouse chromosome 1 and human chromosome 2 as the loci for imprinted genes.