Leaf senescence is a complex but tightly regulated developmental process involving a coordinated sequence of multiple molecular events, which ultimately leads to death of the leaf. Efforts to ...understand the mechanistic principles underlying leaf senescence have been largely made by transcriptomic, proteomic, and metabolomic studies over the past decade. This review focuses on recent milestones in leaf senes- cence research obtained using multi-omics technologies, as well as future endeavors toward systems understanding of leaf senescence processes. In particular, we discuss recent advances in understanding molecular events during leaf senescence through genome-wide transcriptome analyses in Arabidopsis. We also describe comparative transcriptome analyses used to unveil the commonality and diversity of regulatory mechanisms governing leaf senescence in the plant kingdom. Finally, we provide current illustrations of epigenomic, proteomic, and metabolomic landscapes of leaf senescence. We envisage that integration of multi-omics leaf senescence data will enable us to address unresolved questions regarding leaf senescence, including determining the molecular principles that coordinate concurrent and ordered changes in biological events during leaf senescence.
Background
Although lung macrophages are directly exposed to external stimuli, their exact immunologic roles in asthma are still largely unknown. The aim of this study was to investigate the ...anti‐asthmatic effect of Acinetobacter lwoffii in terms of lung macrophage modulation.
Methods
Six‐week‐old female BALB/c mice were sensitized and challenged with ovalbumin (OVA) with or without intranasal administration of A. lwoffii during the sensitization period. Airway hyperresponsiveness and inflammation were evaluated. Using flow cytometry, macrophages were subclassified according to their activation status. In the in vitro study, a murine alveolar macrophage cell line (MH‐S) treated with or without A. lwoffii before IL‐13 stimulation were analysed by quantitative RT‐PCR.
Results
In a murine asthma model, the number of inflammatory cells, including macrophages and eosinophils, decreased in mice treated with A. lwoffii (A. lwoffii/OVA group) compared with untreated mice (OVA group). The enhanced expression of MHCII in macrophages in the OVA group was decreased by A. lwoffii treatment. M2 macrophage subtypes were significantly altered. A. lwoffii treatment decreased CD11b+M2a and CD11b+M2c macrophages, which showed strong positive correlations with Th2 cells, ILC2 and eosinophils. In contrast, CD11b+M2b macrophages were significantly increased by A. lwoffii treatment and showed strong positive correlations with ILC1 and ILC3. In vitro, A. lwoffii down‐regulated the expression of M2 markers related but up‐regulated those related to M2b macrophages.
Conclusions and Clinical Relevance
Intranasal A. lwoffii exposure suppresses asthma development by suppressing the type 2 response via modulating lung macrophage activation, shifting M2a and M2c macrophages to M2b macrophages.
Flow cytometry was performed on a murine asthma model to assess the phenotype of macrophages, innate lymphoid cells and T cells. Intranasal administration of Acinetobacter lwoffii alleviated Th2 inflammation through modulation of macrophage polarization: the lung macrophages tended to be M2b and less M2a, M2c. A. lwoffii also modulated innate lymphoid cells and T cells resulting in a lowered type 2 immune response.
How do organisms, organs, tissues and cells change their fate when they age towards senescence and death? Plant leaves provide a unique window to explore this question because they show reproducible ...life history and are readily accessible for experimental assays. Throughout their lifespan, leaves undergo a series of developmental, physiological and metabolic transitions that culminate in senescence and death. Leaf senescence is an 'altruistic death' that allows for the degradation of the nutrients that are produced during the growth phase of the leaf and their redistribution to developing seeds or other parts of the plant, and thus is a strategy that has evolved to maximize the fitness of the plant. During the past decade, there has been significant progress towards understanding the key molecular principles of leaf senescence using genetic and molecular studies, as well as 'omics' analyses. It is now apparent that leaf senescence is a highly complex genetic program that is tightly controlled by multiple layers of regulation, including at the level of chromatin and transcription, as well as by post-transcriptional, translational and post-translational regulation. This Commentary discusses the latest understandings and insights into the underlying molecular mechanisms, and presents the perspectives necessary to enable our system-level understanding of leaf senescence, together with their possible implications for aging in general.
Some western countries recently have shown a slowdown in the incidence of allergic diseases after worldwide increasing trends, but there are few data from Asian populations concerning changing trend ...of allergic diseases. We evaluated the recent trends in the prevalence of asthma and other allergic diseases in Korea.
From the database of Korean National Health Insurance, a nationwide diagnostic data from 2009 to 2014 were extracted and the national prevalence was analyzed.
The prevalence per 1000 people of atopic dermatitis, allergic rhinitis, and asthma in 2014 was 19.0, 133.1, and 36.3, respectively. The prevalence of three diseases was highest in the age group under 10 as, 95.0, 384.1, and 132.1 per 1000 people, while the prevalence in the over-10-year-group was only 11.6, 109.5, and 27.3, respectively. The prevalence of atopic dermatitis and allergic rhinitis gradually decreased with older age, but the prevalence of asthma showed a re-increasing pattern from the age group 30–39 and reached another peak for the age group 70–79. During the study period, the prevalence of asthma and atopic dermatitis showed decreasing tendency. In contrast, the prevalence of allergic rhinitis steadily increased until 2013, especially in the age group under 10.
The national prevalence of atopic dermatitis, and asthma did not show noticeable increase any more in Korea. However, the prevalence of allergic rhinitis still on the rise until recently, especially in the age group under 10. This is the first report in Asia suggesting a slowdown of the incidence of allergic diseases.
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Aging induces gradual yet massive cell death in higher organisms, including annual plants. Even so, the underlying regulatory mechanisms are barely known, despite the long-standing interest in this ...topic. Here, we demonstrate that ORE1, which is a NAC (NAM, ATAF, and CUC) transcription factor, positively regulates aging-induced cell death in Arabidopsis leaves. ORE1 expression is up-regulated concurrently with leaf aging by EIN2 but is negatively regulated by miR164. miR164 expression gradually decreases with aging through negative regulation by EIN2, which leads to the elaborate up-regulation of ORE1 expression. However, EIN2 still contributes to aging-induced cell death in the absence of ORE1. The trifurcate feed-forward pathway involving ORE1, miR164, and EIN2 provides a highly robust regulation to ensure that aging induces cell death in Arabidopsis leaves.
The harmonized actions of ovarian E2 and progesterone (P4) regulate the proliferation and differentiation of uterine cells in a spatiotemporal manner. Imbalances between these hormones often lead to ...infertility and gynecologic diseases. Whereas numerous factors that are involved in P4 signaling have been identified, few local factors that mediate E2 actions in the uterus have been revealed. Here, we demonstrate that estrogen induces the transcription factor, early growth response 1 (Egr1), to fine‐tune its actions in uterine epithelial cells (ECs) that are responsible for uterine receptivity for embryo implantation. In the presence of exogenous gonadotrophins, ovulation, fertilization, and embryonic development normally occur in Egr1−/− mice, but these animals experience the complete failure of embryo implantation with reduced artificial decidualization. Although serum levels of E2 and P4 were comparable between Egr1+/+ and Egr1−/− mice on d 4 of pregnancy, aberrantly reduced levels of progesterone receptor in Egr1−/− uterine ECs caused enhanced E2 activity and impaired P4 response. Ultra‐ structural analyses revealed that Egr1−/− ECs are not fully able to provide proper uterine receptivity. Uterine mRNA landscapes in Egr1−/− mice revealed that EGR1 controls the expression of a subset of E2‐regulated genes. In addition, P4 signaling was unable to modulate estrogen actions, including those that are involved in cell‐cycle progression, in ECs that were deficient in EGR1. Furthermore, primary coculture of Egr1−/− ECs with Egr1+/+ stromal cells, and vice versa, supported the notion that Egr1 is required to modulate E2 actions on ECs to prepare the uterine environment for embryo implantation. In contrast to its role in ECs, loss of Egr1 in stroma significantly reduced stromal cell proliferation. Collectively, our results demonstrate that E2 induces EGR1 to streamline its actions for the preparation of uterine receptivity for embryo implantation in mice.—Kim, H.‐R., Kim, Y. S., Yoon, J. A., Yang, S. C., Park, M., Seol, D.‐W., Lyu, S. W., Jun, J. H., Lim, H. J., Lee, D. R., Song, H. Estrogen induces EGR1 to fine‐tune its actions on uterine epithelium by controlling PR signaling for successful embryo implantation. FASEB J. 32,1184‐1195 (2018). www.fasebj.org
Massive air pollutants originating in China and their trans-boundary transports are an international concern in East Asia. Despite its importance, details in the trans-boundary transport of air ...pollutants over East Asia and its impact on regional air quality remain to be clarified. This study presents an evidence which strong support that aerosols emitting in China play a major role in the occurrence of multi-day (≥4 days) severe air pollution episodes in cold seasons (October through March) for 2001–2013 in Seoul, Korea, where the concentration of PM10 (particulates with diameters ≤ 10 μm) exceeds 100 μg m−3. Observations show that these multi-day severe air pollution episodes occur when a strong high-pressure system resides over the eastern China–Korea region. In such weather conditions, air pollutants emitted in eastern China/southwestern Manchuria are trapped within the atmospheric boundary layer, and gradually spread into neighboring countries by weak lower tropospheric westerlies. Understanding of trans-boundary transports of air pollutants will advance the predictability of local air quality, and will encourage the development of international measures to improve air quality.
•We examined a possible cause of the onset of multi-day high-PM10 episodes in Seoul.•The episodes mainly occur by a strong high-pressure and weak westerlies.•The atmospheric fields help trans-boundary pollutant transports from China to Seoul.
Objectives
Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) vaccine effectiveness in coronavirus disease (COVID-19) patients with breakthrough infections has not been established in South ...Korea. To address this, we assessed the impact of vaccination on symptom occurrence and viral load.
Methods
We performed a retrospective cohort study of 9,030 COVID-19 patients enrolled between February and November 2021. The impact of vaccination on the incidence of symptoms and viral load as indicated by cycle threshold (Ct) values of
RdRp
and
E
genes was evaluated using relative risks (RRs) and 95% confidence intervals (95% CIs).
Results
Compared with unvaccinated patients, fully vaccinated patients were associated with a reduced symptom onset of cough, sputum, and myalgia in COVID-19 patients (RR (95% CI) = 0.86 (0.75–0.99) for cough; RR (95% CI) = 0.74 (0.56–0.98) for sputum; RR (95% CI) = 0.65 (0.53–0.79) for myalgia, respectively). Additionally, lower risk of high viral load, Ct value of
RdRp
gene <15 or Ct value of
E
gene <15, was observed especially in fully vaccinated patients younger than 40 years ((RR (95% CI) = 0.69 (0.49–0.96) for
RdRp
gene; (RR (95% CI) = 0.71 (0.53–0.95) for
E
gene).
Conclusion
SARS-CoV-2 vaccination was associated with a reduced risk of COVID-19 symptoms as well as decreased viral load, especially in patients younger than 40 years.
Intimate two-way interactions between the implantation-competent blastocyst and receptive uterus are prerequisite for successful embryo implantation. In humans, recurrent/repeated implantation ...failure (RIF) may occur due to altered uterine receptivity with aberrant gene expression in the endometrium as well as genetic defects in embryos. Several studies have been performed to understand dynamic changes of uterine transcriptome during menstrual cycles in humans. However, uterine transcriptome of the patients with RIF has not been clearly investigated yet. Here we show that several signaling pathways as well as many genes and microRNAs are dysregulated in the endometrium of patients with RIF (RIFE). Whereas unsupervised hierarchical clustering showed that overall mRNA and microRNA profiles of RIFE were similar to those of endometria of healthy women, many genes were significantly dysregulated in RIFE (cut off at 1.5 fold change). The majority (~75%) of differentially expressed genes in RIFE including S100 calcium binding protein P (S100P), Chemokine (C-X-C motif) ligand 13 (CXCL13) and SIX homeobox 1 (SIX1) were down-regulated, suggesting that reduced uterine expression of these genes is associated with RIF. Gene Set Enrichment analyses (GSEA) for mRNA microarrays revealed that various signaling pathways including Leukemia inhibitory factor (LIF) signaling and a P4 response were dysregulated in RIFE although expression levels of Estrogen receptor α (ERα) and Progesterone receptor (PR) were not significantly altered in RIFE. Furthermore, expression and phosphorylation of Signal transducer and activator of transcription 3 (STAT3) are reduced and a gene set associated with Janus kinase (JAK)-STAT signaling pathway is systemically down-regulated in these patients. Pairwise analyses of microRNA arrays with prediction of dysregulated microRNAs based on mRNA expression datasets demonstrated that 6 microRNAs are aberrantly regulated in RIFE. Collectively, we here suggest that dysregulation of several major signaling pathways and genes critical for uterine biology and embryo implantation may lead to uterine abnormalities in patients with RIF.
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