117 research outputs found
MFG-E8 Regulates Angiogenesis in Cutaneous Wound Healing
Our research group recently demonstrated that pericytes are major sources of the secreted glycoprotein and integrin ligand lactadherin (MFG-E8) in B16 melanoma tumors, and that MFG-E8 promotes angiogenesis via enhanced PDGF–PDGFRβ signaling mediated by integrin–growth factor receptor crosstalk. However, sources of MFG-E8 and its possible roles in skin physiology are not well characterized. The objective of this study was to characterize the involvement of MFG-E8 in skin wound healing. In the dermis of normal murine and human skin, accumulations of MFG-E8 were found around CD31+ blood vessels, and MFG-E8 colocalized with PDGFRβ+, αSMA+, and NG2+ pericytes. MFG-E8 protein and mRNA levels were elevated in the dermis during full-thickness wound healing in mice. MFG-E8 was diffusely present in granulation tissue and was localized around blood vessels. Wound healing was delayed in MFG-E8 knockout mice, compared with the wild type, and myofibroblast and vessel numbers in wound areas were significantly reduced in knockout mice. Inhibition of MFG-E8 production with siRNA attenuated the formation of capillary-like structures in vitro. Expression of MFG-E8 in fibrous human granulation tissue with scant blood vessels was less than that in granulation tissue with many blood vessels. These findings suggest that MFG-E8 promotes cutaneous wound healing by enhancing angiogenesis
Measuring the Broad-band X-Ray Spectrum from 400 eV to 40 keV in the Southwest Part of the Supernova Remnant RX J1713.7-3946
We report on results from Suzaku broadband X-ray observations of the
southwest part of the Galactic supernova remnant (SNR) RX J1713.7-3946 with an
energy coverage of 0.4-40 keV. The X-ray spectrum, presumably of synchrotron
origin, is known to be completely lineless, making this SNR ideally suited for
a detailed study of the X-ray spectral shape formed through efficient particle
acceleration at high speed shocks. With a sensitive hard X-ray measurement from
the HXD PIN on board Suzaku, we determine the hard X-ray spectrum in the 12--40
keV range to be described by a power law with photon index Gamma = 3.2+/- 0.2,
significantly steeper than the soft X-ray index of Gamma = 2.4+/- 0.05 measured
previously with ASCA and other missions. We find that a simple power law fails
to describe the full spectral range of 0.4-40 keV and instead a power-law with
an exponential cutoff with hard index Gamma = 1.50+/- 0.09 and high-energy
cutoff epsilon_c = 1.2+/- 0.3 keV formally provides an excellent fit over the
full bandpass. If we use the so-called SRCUT model, as an alternative model, it
gives the best-fit rolloff energy of epsilon_{roll} = 0.95+/- 0.04 keV.
Together with the TeV gamma-ray spectrum ranging from 0.3 to 100 TeV obtained
recently by HESS observations, our Suzaku observations of RX J1713.7-3946
provide stringent constraints on the highest energy particles accelerated in a
supernova shock.Comment: 11 pages, 11 figures, accepted for publication in Publications of the
Astronomical Society of Japan (PASJ
Anti-IL-6 Receptor Antibody Causes Less Promotion of Tuberculosis Infection than Anti-TNF-α Antibody in Mice
Objective. Our aim was to investigate the effects of IL-6 blockade on the progression of Mycobacterium tuberculosis (TB) and compare them with those of TNF-α blockade in mice. Methods. Mice were intravenously infected with TB and injected with antibodies. Survival was monitored and histological and immunological studies were carried out. Results. All anti-IL-6R Ab-treated mice and 8 of 10 control mice survived until sacrificed 224 days after TB challenge, whereas anti-TNF-α Ab-treated mice all died between 120 and 181 days. Anti-IL-6R Ab-treated mice exhibited no significant differences in TB CFU in organs, including the lungs, and no deterioration in histopathology compared to control mice at 4 weeks. In contrast, anti-TNF-α Ab-treated mice exhibited increased TB CFU and greater progression of histopathological findings in organs than control mice. Spleen cells from anti-TNF-α Ab-treated mice had decreased antigen-specific response in IFN-γ release and proliferation assays. The results in anti-IL-6R Ab-treated mice suggest that spleen cell responses were decreased to a lesser degree. Similar results were obtained in IL-6 knockout (KO) mice, compared with TNF receptor 1 (TNFR1) KO and TNFR1/IL-6 double KO (DKO) mice. Conclusion. IL-6R blockade promotes the progression of TB infection in mice far less than TNF-α blockade
Genetic Variation in Quercus acutissima Carruth., in Traditional Japanese Rural Forests and Agricultural Landscapes, Revealed by Chloroplast Microsatellite Markers
uercus acutissima Carruth. is an economically important species that has long been cultivated in Japan, so is a valuable subject for investigating the impact of human activities on genetic variation in trees. In total, 2152 samples from 18 naturally regenerated populations and 28 planted populations in Japan and 13 populations from the northeastern part of Eurasia, near Japan, were analyzed using six maternally inherited chloroplast (cpDNA) simple sequence repeat (SSR) markers. Although 23 haplotypes were detected in total, both the Japanese natural and artificial populations exhibited much lower genetic diversity than the continental populations. The level of genetic differentiation among natural populations in Japan was also much lower (G’ST = 0.261) than that on the continent (G’ST = 0.856). These results suggest that human activities, such as historical seed transfer, have reduced genetic diversity within and among populations and resulted in a homogeneous genetic structure in Japan. The genetic characteristics of natural and artificial populations of Quercus acutissima in Japan are almost the same and it is likely that most of the natural populations are thought to have originated from individuals that escaped from plantations
microRNA-345の過剰発現は、MUC1およびTJP2の発現を抑制することにより、膵管腺癌細胞株の浸潤能に影響を及ぼす
The majority of pancreatic carcinomas are pancreatic ductal adenocarcinomas (PDAC), and
the presence of non-invasive pancreatic intraepithelial neoplasia or intraductal papillary mucinous
neoplasm, as an associated lesion, is considered important. These microscopic hyperplastic or grossly
papillomatous lesions exhibit varying degrees of morphological atypia and may develop into invasive
carcinomas. In this study, we investigated whether mucin-1 (MUC1) is involved in the progression of
pancreatic carcinoma and examined the mechanisms by which microRNAs regulate MUC1 expression
in vitro. In PDAC cell lines, suppression of MUC1 expression reduced cell proliferation and invasion;
PDAC cell lines transfected with an miR-345 precursor suppressed the expression of MUC1, and
reduced cell proliferation and invasion. Tight junction protein 2 (TJP2), a putative target of miR-345,
is regulated by MUC1. The suppression of TJP2 expression reduced cell proliferation by inducing
apoptosis. These results suggest that MUC1 and TJP2, the putative target molecules of miR-345,
are critical in maintaining the invasive potential of pancreatic carcinoma cells, and regulating their
expression may prevent the progression of non-invasive pancreatic intraductal lesions to invasive
carcinomas. This study provides new insights for the development of novel molecular targeted
therapies for pancreatic carcinomas.博士(医学)・甲第866号・令和5年3月15
内視鏡超音波ガイド下穿刺吸引の液状検体の残余を用いたK-ras 遺伝子検査は正診率を高める
Background: Endoscopic ultrasound-guided fine needle aspiration (EUS-FNA) technology is widely used for the diagnosis of pancreatic masses. However, in some cases, inadequate tissue volume or difficulty of morphological diagnosis are constraining factors for adequate cytopathological evaluation. K-ras mutation is the most frequently acquired genetic abnormality, occurring in approximately 90% of all patients with pancreatic ductal adenocarcinoma (PDAC). In the present study, the clinical utility of residual liquid-based cytology (LBC) specimens obtained using EUS-FNA for K-ras mutation analysis was evaluated. Methods: In this study, 81 patients with pancreatic lesions were examined. The cell block (CB) specimens separated from EUS-FNA samples were morphologically evaluated by hematoxylin-eosin (HE) staining. Final diagnoses were confirmed by CB specimens, surgical resection specimens, diagnostic imaging, and clinical follow-up. Genomic DNA of residual LBC specimens stored at 4°C for several months were extracted and assessed for K-ras mutations using a fluorescence resonance energy transfer-based preferential homoduplex formation assay. Results: K-ras mutation analysis using residual LBC samples was successful in all cases. The sensitivity, specificity, and accuracy of CB examination alone were 77.4%, 100%, and 81.3%, respectively, and those of the combination of CB examination and K-ras mutation analysis were 90.3%, 92.3%, and 90.7%, respectively. Furthermore, K-ras mutations were detected in 8 (57.1%) of 14 PDAC samples for which the CB results were inconclusive. Conclusion: These findings suggest that K-ras mutation analysis using residual LBC specimens improves the diagnostic accuracy of EUS-FNA.博士(医学)・乙第1492号・令和2年12月24日Copyright: © 2018 Sekita-Hatakeyama et al. This is an open access article distributed under the terms of the Creative Commons Attribution License(https://creativecommons.org/licenses/by/4.0/), which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited
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