Apoptosis-induced Proliferation in UV-Irradiated Human Conjunctival Epithelial Cells

A pterygium is a benign growth that develops on the conjunctiva and, in some cases, extends to the cornea and interferes with vision. Excessive exposure to ultraviolet (UV) light is one of the causes of pterygium development. We previously reported that UV-induced apoptosis is led by production of reactive oxygen species (ROS) that activate p38 mitogen-activated protein kinase (MAPK) in human conjunctival epithelial (HCE) cells. Also, ROS-dependent induction of interleukin-11 (IL-11) has been reported to upregulate MAPK pathways, which results in compensatory proliferation. In this study, we examined the effect of UV exposure on HCE cells, in terms of change in apoptosis, ROS generation, phosphorylation of c-Jun N-terminal kinase (JNK), levels of IL-11 (a key cytokine in tissue repair and compensatory proliferation), production of activator protein 1 (AP-1), and expression of c-myc, c-fos and c-jun (which provides evidence of healthy cell proliferation). Apoptosis in HCE cells was induced by UV light irradiation (312nm, 4.94mW/cm2). Apoptosis was measured using the Muse Annexin V and Dead Cell Assay Kit. ROS generation was measured by using 5-(and 6-) chloromethyl-2\u277\u27-dichlorodihydrofluorescein diacetate, acetyl ester. JNK phosphorylation, IL-11 levels and AP-1 production were measured by enzyme-linked immunosorbent assays (ELISAs). Imnunocytochemical staining was used to measure c-myc, c-fos and c-jun expression. UV irradiation increased ROS generation, phosphorylation of JNK, and apoptotic cell count. IL-11 levels and AP-1 production were significantly increased by UV irradiation. The irradiated cells had increased expression of c-myc, c-fos and c-jun, and treatment of the cells with IL-11 significantly increased expression of c-myc, c-fos and c-jun. These results suggest that the release of IL-11 from UV-induced apoptotic HCE cells and surrounding healthy cells could promote proliferation to maintain homeostasis

Relationship of Grade of Malignant Brain Tumor to Cancer Stem Cells and Survivin Expression

Glioblastoma (GBM) is difficult to completely cure by surgical treatment alone, and it is generally treated with a combination of surgery, radiotherapy, and chemotherapy. However, GBM is resistant to radiotherapy and chemotherapy, and complete cure cannot be achieved. Cancer stem cells (CSC) and survivin, which inhibit apoptosis, are considered as factors underlying tumor recurrence and the radiation- and drug-resistance of these tumors. We analyzed CSC and survivin expression in surgically excised specimens of malignant brain tumors to establish the relationships between the grades and CSC and survivin expression and between MIB-1 (Ki-67) expression and resistance. No relationship was noted between the grades and CSC or survivin expression, or between MIB-1 and CSC expression or between Grade 3 and 4 MIB-1 and survivin expression, although a correlation was noted between MIB-1 and survivin expression in Grade II tumors. These findings suggested that CSC are consistently contained in tumor tissue at a specific rate regardless of the histological grade, and the apoptosis of cells with low-level proliferative and cell cycling activities does not occur because these cells do not respond to chemotherapy or radiation, being resistant to treatment

Eribulin Treatment Induces High Expression of miR-195 and Inactivates the Wnt/β - catenin Signaling Pathway in Triple-negative Breast Cancer

Triple-negative breast cancer （TNBC） accounts for 10-15％ of all breast cancer cases and shows a poor prognosis with 30％ distant metastasis. With few specific target molecules and ineffective hormonal and anti-HER2 treatment, an alternative therapeutic method for TNBC is urgently required. Recently, a non-taxane inhibitor of microtubule dynamics called eribulin was developed for breast cancer therapy. Eribulin induces irreversible mitotic mass formation in cancer cells during the G2-M phase, initiating apoptosis; however, the mechanism underlying this eribulin activity remains unclear. We reported previously that exposing non-basal-like （NBL） TNBC cells to eribulin increases miR-195 expression, which in turn decreases the expression of targeted Wnt3a. The present study sought to further clarify the mechanism of this antitumor effect by exploring how eribulin affects Wnt/β - catenin signaling based on miRNA expression changes in TNBC. In an NBL type of human breast cancer cell line （MDA-MB-231 cells）, we compared the expression levels of Wnt/β catenin signaling pathway proteins in cells exposed to an miR-195 mimic （cells transfected with miR-195 and in which Wnt3a expression was suppressed） and in cells exposed to eribulin. Expression levels of Wnt3a, β -catenin, and GSK-3β were measured by ELISA and observed by fluorescence immunostaining. Wnt3a and β -catenin expression was significantly lower and GSK-3β expression was significantly higher in the cells exposed to eribulin and transfected with miR-195 mimic than in the untreated controls, suggesting that eribulin inactivates the Wnt/β -catenin signaling pathway. Therefore, a novel antitumor mechanism of eribulin was determined, whereby eribulin induces high expression of miR-195 to inactivate the Wnt/β -catenin signaling pathway in NBL-type TNBC

Aldehyde dehydrogenase 3A1 protects airway epithelial cells from cigarette smoke-induced DNA damage and cytotoxicity

Aldehyde dehydrogenase 3A1 (ALDH3A1), an ALDH superfamily member, catalyzes the oxidation of reactive aldehydes, highly toxic components of cigarette smoke (CS). Even so, the role of ALDH3A1 in CS-induced cytotoxicity and DNA damage has not been examined. Among all of the ALDH superfamily members, ALDH3A1 mRNA levels showed the greatest induction in response to CS extract (CSE) exposure of primary human bronchial epithelial cells (HBECs). ALDH3A1 protein accumulation was accompanied by increased ALDH enzymatic activity in CSE-exposed immortalized HBECs. The effects of overexpression or suppression of ALDH3A1 on CSE-induced cytotoxicity and DNA damage (γH2AX) were evaluated in cultured immortalized HBECs. Enforced expression of ALDH3A1 attenuated cytotoxicity and downregulated γH2AX. siRNA-mediated suppression of ALDH3A1 blocked ALDH enzymatic activity and augmented cytotoxicity in CSE-exposed cells. Our results suggest that the availability of ALDH3A1 is important for cell survival against CSE in HBECs

Predictive factors of mortality of patients with fragility hip fractures at 1 year after discharge : A multicenter, retrospective study in the northern Kyushu district of Japan

Purpose: Fragility hip fractures (FHFs) are associated with a high risk of mortality, but the relative contribution of various factors remains controversial. This study aimed to evaluate predictive factors of mortality at 1 year after discharge in Japan. Methods: A total of 497 patients aged 60 years or older who sustained FHFs during follow-up were included in this study. Expected variables were finally assessed using multivariable Cox proportional hazards models. Results: The 1-year mortality rate was 9.1% (95% confidence interval: 6.8–12.0%, n = 45). Log-rank test revealed that previous fractures (p = 0.003), Barthel index (BI) at discharge (p = 0.011), and place-to-discharge (p = 0.004) were significantly associated with mortality for male patients. Meanwhile, body mass index (BMI; p = 0.023), total Charlson comorbidity index (TCCI; p = 0.005), smoking (p = 0.007), length of hospital stay (LOS; p = 0.009), and BI (p = 0.004) were the counterparts for females. By multivariate analyses, previous vertebral fractures (hazard ratio (HR) 3.33; p = 0.044), and BI <30 (HR 5.42, p = 0.013) were the predictive variables of mortality for male patients. BMI <18.5 kg/m2 (HR 2.70, p = 0.023), TCCI ≥5 (HR 2.61, p = 0.032), smoking history (HR 3.59, p = 0.018), LOS <14 days (HR 13.9; p = 0.007), and BI <30 (HR 2.76; p = 0.049) were the counterparts for females. Conclusions: Previous vertebral fractures and BI <30 were the predictive variables of mortality for male patients, and BMI <18.5 kg/m2, TCCI ≥5, smoking history, LOS <14 days, and BI <30 were those for females. Decreased BI is one of the independent and preventable risk factors. A comprehensive therapeutic approach should be considered to prevent deterioration of activities of daily living and a higher risk of mortality

DOCK2 is involved in the host genetics and biology of severe COVID-19

「コロナ制圧タスクフォース」COVID-19疾患感受性遺伝子DOCK2の重症化機序を解明 --アジア最大のバイオレポジトリーでCOVID-19の治療標的を発見--. 京都大学プレスリリース. 2022-08-10.Identifying the host genetic factors underlying severe COVID-19 is an emerging challenge. Here we conducted a genome-wide association study (GWAS) involving 2, 393 cases of COVID-19 in a cohort of Japanese individuals collected during the initial waves of the pandemic, with 3, 289 unaffected controls. We identified a variant on chromosome 5 at 5q35 (rs60200309-A), close to the dedicator of cytokinesis 2 gene (DOCK2), which was associated with severe COVID-19 in patients less than 65 years of age. This risk allele was prevalent in East Asian individuals but rare in Europeans, highlighting the value of genome-wide association studies in non-European populations. RNA-sequencing analysis of 473 bulk peripheral blood samples identified decreased expression of DOCK2 associated with the risk allele in these younger patients. DOCK2 expression was suppressed in patients with severe cases of COVID-19. Single-cell RNA-sequencing analysis (n = 61 individuals) identified cell-type-specific downregulation of DOCK2 and a COVID-19-specific decreasing effect of the risk allele on DOCK2 expression in non-classical monocytes. Immunohistochemistry of lung specimens from patients with severe COVID-19 pneumonia showed suppressed DOCK2 expression. Moreover, inhibition of DOCK2 function with CPYPP increased the severity of pneumonia in a Syrian hamster model of SARS-CoV-2 infection, characterized by weight loss, lung oedema, enhanced viral loads, impaired macrophage recruitment and dysregulated type I interferon responses. We conclude that DOCK2 has an important role in the host immune response to SARS-CoV-2 infection and the development of severe COVID-19, and could be further explored as a potential biomarker and/or therapeutic target

The whole blood transcriptional regulation landscape in 465 COVID-19 infected samples from Japan COVID-19 Task Force

「コロナ制圧タスクフォース」COVID-19患者由来の血液細胞における遺伝子発現の網羅的解析 --重症度に応じた遺伝子発現の変化には、ヒトゲノム配列の個人差が影響する--. 京都大学プレスリリース. 2022-08-23.Coronavirus disease 2019 (COVID-19) is a recently-emerged infectious disease that has caused millions of deaths, where comprehensive understanding of disease mechanisms is still unestablished. In particular, studies of gene expression dynamics and regulation landscape in COVID-19 infected individuals are limited. Here, we report on a thorough analysis of whole blood RNA-seq data from 465 genotyped samples from the Japan COVID-19 Task Force, including 359 severe and 106 non-severe COVID-19 cases. We discover 1169 putative causal expression quantitative trait loci (eQTLs) including 34 possible colocalizations with biobank fine-mapping results of hematopoietic traits in a Japanese population, 1549 putative causal splice QTLs (sQTLs; e.g. two independent sQTLs at TOR1AIP1), as well as biologically interpretable trans-eQTL examples (e.g., REST and STING1), all fine-mapped at single variant resolution. We perform differential gene expression analysis to elucidate 198 genes with increased expression in severe COVID-19 cases and enriched for innate immune-related functions. Finally, we evaluate the limited but non-zero effect of COVID-19 phenotype on eQTL discovery, and highlight the presence of COVID-19 severity-interaction eQTLs (ieQTLs; e.g., CLEC4C and MYBL2). Our study provides a comprehensive catalog of whole blood regulatory variants in Japanese, as well as a reference for transcriptional landscapes in response to COVID-19 infection

Seismic exploration at Fuji volcano with active sources : The outline of the experiment and the arrival time data

Fuji volcano (altitude 3,776m) is the largest basaltic stratovolcano in Japan. In late August and early September 2003, seismic exploration was conducted around Fuji volcano by the detonation of 500 kg charges of dynamite to investigate the seismic structure of that area. Seismographs with an eigenfrequency of 2 Hz were used for observation, positioned along a WSW-ENE line passing through the summit of the mountain. A total of 469 seismic stations were installed at intervals of 250-500 m. The data were stored in memory on-site using data loggers. The sampling interval was 4 ms. Charges were detonated at 5 points, one at each end of the observation line and 3 along its length. The first arrival times and the later-phase arrival times at each station for each detonation were recorded as data. P-wave velocities in the surface layer were estimated from the travel time curves near the explosion points, with results of 2.5 km/s obtained for the vicinity of Fuji volcano and 4.0 km5/s elsewhere

Suppressive Effects of Catechins in UV-Induced Cytotoxicity of Human Corneal Epithelial Cells

Photokeratitis is a disease in which the ocular surface is directly affected by oxidative stress caused by exposure to ultraviolet （UV） light and oxygen. It is speculated that the production of free radicals and reactive oxygen species （ROS） is caused by UV-induced cytotoxicity. Recent studies have reported that catechins have antioxidant, antiallergic, antitumor, and antibacterial effects. The aim of our study was to investigate the mechanism of UV-induced cytotoxicity in cultured human corneal epithelial （HCE-T） cells and evaluate the protective effects of the catechins, （?）-epigallocatechin gallate （EGCG） and （?）-epigallocatechin 3-O-（3-O-methyl） gallate （EGCG3”Me）, on apoptosis. HCE-T cells were UV irradiated at 312nm （4.94mW/cm2, 296mJ/cm2）. EGCG and EGCG3”Me were dissolved in methanol and adjusted to 5, 10, or 20?M. Absorption was measured from 250 to 400nm. EGCG and EGCG3”Me were pre-incubated for 1 hr. After UV irradiation, membrane lipid peroxide, tumor necrosis factor （TNF）-α production, ROS generation, caspase-3 and -8 activities, mitochondrial membrane potential, and cytochrome c levels were measured. Both EGCG and EGCG3”Me had UV absorption, and increased with concentration dependently. The increases in the levels of membrane lipid hyperoxidation, activation of caspase-3 and -8, production of TNF-α and ROS were found, by UV irradiation, to be significant. But these levels were significantly decreased by pretreatment with EGCG and EGCG3”Me. There were no changes in mitochondrial membrane potential and cytoplasmic cytochrome c levels after UV irradiation. Oxidative stress occurs early near the cell membrane in response to UV irradiation. As a result, TNF-α is induced, leading to apoptosis mainly through caspase-8 activation. Conversely, EGCG and EGCG3”Me absorb UV light directly and inhibit lipid peroxidation in the cell membrane. Catechins inhibit the apoptosis cascade by inactivating caspase-3 and caspase-8

Protective Role of Fas-FasL Signaling in Lethal Infection with Herpes Simplex Virus Type 2 in Mice▿

Herpes simplex virus type 2 (HSV-2) induces acute local infection followed by latent infection in the nervous system and often leads to the development of lethal encephalitis in immunocompromised hosts. The mechanisms of immune protection against lethal HSV-2 infection, however, have not been clarified. In this study, we examined the roles of Fas-Fas ligand (FasL) signaling in lethal infection with HSV-2 by using mice with mutated Fas (lpr) or FasL (gld) in C57BL/6 background. Both lpr and gld mice exhibited higher mortality than wild-type (WT) C57BL/6 mice after infection with virulent HSV-2 strain 186 and showed significantly increased viral titers in the spinal cord compared with WT mice 9 days after infection, just before the mice started to die. There were no differences in the numbers of CD4+ and CD8+ T cells infiltrated in the spinal cord or in the levels of HSV-2-specific gamma interferon produced by those cells in a comparison of lpr and WT mice 9 days after infection. Adoptive transfer studies demonstrated that CD4+ T cells from WT mice protected gld mice from lethal infection by HSV-2. Furthermore, CD4+ T cells infiltrated in the spinal cord of HSV-2-infected WT mice expressed functional FasL that induced apoptosis of Fas-expressing target cells in vitro. These results suggest that FasL-mediated cytotoxic activity of CD4+ T cells plays an important role in host defense against lethal infection with HSV-2