206 research outputs found
Oligopeptide Transporter-1 is Associated with Fluorescence Intensity of 5-Aminolevulinic Acid-Based Photodynamic Diagnosis in Pancreatic Cancer Cells
[Background] The 5-aminolevulinic acid (ALA)-based photodynamic diagnosis is based on the accumulation of photosensitizing protoporphyrin IX in the tumor after ALA administration. However, the mechanisms connecting exogenous ALA and tumor fluorescence in pancreatic cancer remain unclear. We aimed to elucidate the mechanism underlying the ALA-induced fluorescent. [Methods] Human pancreatic duct epithelial cells (hPDECs) and pancreatic cancer cell lines were used. The expressions of ALA-associated enzymes and membrane transporters in these cell lines were investigated. ALA-induced fluorescence was also investigated. [Results] The expression of oligopeptide transporter-1 (PEPT-1), through which ALA is absorbed, was significantly higher in AsPC-1 cells and lower in MIA PaCa-2 cells than in hPDECs. AsPC-1 cells showed rapid and intense fluorescence after ALA administration, and that was attenuated by PEPT-1 inhibition. ALA-induced fluorescence was not sufficiently strong in MIA PaCa-2 cells to distinguish the cells from hPDECs. [Conclusion] We revealed the association of PEPT-1 with ALA-induced fluorescence. Cancers expressing PEPT-1 could be easily distinguished by this technique from normal cells. These findings help develop novel diagnostic modalities for pancreatic cancer
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Chitinase 3-Like 1 Promotes Macrophage Recruitment and Angiogenesis in Colorectal Cancer
Chitinase 3-like 1 (CHI3L1), one of mammalian members of the chitinase family, is expressed in several types of human cancer, and elevated serum level of CHI3L1 is suggested to be a biomarker of poor prognosis in advanced cancer patients. However, the overall biological function of CHI3L1 in human cancers still remains unknown. Studies were performed to characterize the role of CHI3L1 in cancer pathophysiology utilizing human colorectal cancer samples and human cell lines. Plasma protein and tissue mRNA expression levels of CHI3L1 in colorectal cancer were strongly upregulated. Immunohistochemical analysis showed that CHI3L1 was expressed in cancer cells and CHI3L1 expression had a significant association with the number of infiltrated macrophages and microvessel density. By utilizing trans-well migration and tube formation assays, overexpression of CHI3L1 in SW480 cells (human colon cancer cells) enhanced the migration of THP-1 cells (human macrophage cells) and HUVECs (human endothelial cells), and the tube formation of HUVECs. The knockdown of CHI3L1 by RNA interference or the neutralization of CHI3L1 by anti-CHI3L1 antibody displayed strong suppression of CHI3L1-induced migration and tube formation. Cell proliferation assay showed that CHI3L1 overexpression significantly enhanced the proliferation of SW480 cells. ELISA analysis showed that CHI3L1 increased the secretion of inflammatory chemokines, IL-8 and MCP-1, from SW480 cells through mitogen-activated protein kinase (MAPK) signaling pathway. Both neutralization of IL-8 or MCP-1 and inhibition or knockdown of MAPK in SW480 cells significantly inhibited CHI3L1-induced migration and tube formation. In a xenograft mouse model, overexpression of CHI3L1 in HCT116 cells (human colon cancer cells) enhanced the tumor growth as well as macrophage infiltration and microvessel density. In conclusion, CHI3L1 expressed in colon cancer cells promotes cancer cell proliferation, macrophage recruitment and angiogenesis. Thus, the inhibition of CHI3L1 activity may be a novel therapeutic strategy for human colorectal cancer
Tissue factor expression in human pterygium
Purpose: A pterygium shows tumor-like characteristics, such as proliferation, invasion, and epithelial–mesenchymal transition (EMT). Previous reports suggest that tissue factor (TF) expression is closely related to the EMT of tumor cells, and subsequent tumor development. In this study, we analyzed the expression and immunolocalization of TF in pterygial and normal conjunctival tissues of humans. Methods: Eight pterygia and three normal bulbar conjunctivas, surgically removed, were used in this study. Formalinfixed, paraffin-embedded tissues were submitted for immunohistochemical analysis with anti-TF antibody. Double staining immunohistochemistry was performed to assess TF and alpha-smooth muscle actin (α-SMA) or epidermal growth factor receptor (EGFR) expression in the pterygia. Results: Immunoreactivity for TF was detected in all pterygial tissues examined. TF immunoreactivity was localized in the cytoplasm of basal, suprabasal, and superficial epithelial cells. The number of TF-immunopositive cells in pterygial epithelial cells was significantly higher than in normal conjunctival epithelial cells (p<0.001). TF immunoreactivity was detected in α-SMA-positive or -negative pterygial epithelial cells. EGFR immunoreactivity was detected in pterygial epithelium, which was colocalized with TF. Conclusions: These results suggest that TF plays a potential role in the pathogenesis and development of a pterygium, and that TF expression might be involved through EMT-dependent and -independent pathways
Wavelet analysis of transonic buffet on a two-dimensional airfoil with vortex generators
We visualized the shock buffets on a two-dimensional transonic airfoil with and without vortex generators (VGs) by using a fast-framing focusing schlieren imaging. The focusing schlieren visualization showed that the flow three-dimensionality around the airfoil became remarkable with installing the VGs. This implies that narrow depth of focus of imaging systems was a key to accurately capture the characteristics of the shock oscillation due to the buffet for the cases with VGs. The time-resolved imaging also revealed that non-periodic components were included in the shock oscillation due to the buffet for the cases with VGs. This prevented Fourier analysis from being applied. We used wavelet analysis to extract the characteristic of the shock oscillation for the cases with VGs. The wavelet spectrograms revealed that the low-frequency oscillation having the buffet frequency was still included intermittently in the shock oscillation even when VG controlled the buffet. The rate of appearing the low-frequency oscillation increased with increasing both the interval between VGs and the angle of attack
Ipragliflozin Ameliorates Endoplasmic Reticulum Stress and Apoptosis through Preventing Ectopic Lipid Deposition in Renal Tubules
Background: Chronic kidney disease (CKD) and non-alcoholic steatohepatitis (NASH) are major health burdens closely related to metabolic syndrome. A link between CKD and NASH has been assumed; however, the underlying mechanism is still unknown. Ectopic lipid deposition (ELD) in the hepatocyte results in endoplasmic reticulum (ER) stress, which plays an important role in the development of steatohepatitis. ELD is also assumed to play a role in the development of kidney injury. We aimed to investigate the role of ELD and ER stress in the development of CKD, and evaluate the efficacy of a sodium glucose cotransporter-2 inhibitor, ipragliflozin. Methods: Male FLS-ob/ob mice that closely imitate the pathophysiology of NASH were treated with vehicle or ipragliflozin. Metabolic characteristics, histology of the kidney, ER stress, and apoptotic signals were evaluated. Results: The serum triglyceride was significantly lower in mice treated with ipragliflozin. Ipragliflozin reduced ELD in renal tubules. Ipragliflozin also reduced the expression levels of GRP78 and CHOP, apoptotic cells, and interstitial fibrosis. Conclusions: ELD induced kidney injury through ER stress. Ipragliflozin improved the pathogenesis of CKD by reducing ELD and ER stress in NASH-model mice. Our results suggest ipragliflozin has therapeutic effect on CKD in NASH
A novel method for assessing the renal biopsy specimens using an activatable fluorescent probe
Gamma-glutamyl hydroxymethyl rhodamine green (gGlu-HMRG) is an activatable fluorescent probe that can be activated by γ-glutamyltranspeptidase (GGT). The expression of GGT in the kidney, which is one of the major organs exhibiting enhanced GGT expression, is exclusively localised to the cortex. Here, we aimed to investigate the feasibility of gGlu-HMRG as a probe for the on-site assessment of renal biopsy specimens. gGlu-HMRG fluorescent probe was applied to the renal proximal tubular epithelial cells and cortical collecting duct cells in vitro, mouse kidneys ex vivo, and human biopsy specimens. In addition, the fluorescence intensities in the cortex and the medulla were comparatively evaluated in the biopsy specimens. The fluorescence signal was rapidly detected in the renal proximal tubular epithelial cells, whereas that in the cortical collecting duct cells was not detected. The fluorescence signal was detected in the mouse kidneys ex vivo without markedly affecting the tissue morphology. In the human biopsy specimens, the fluorescence signal in the cortex was significantly distinct from that in the medulla (p?<?0.05). Thus, this fluorescent probe can be used to distinctly identify the renal cortex in the biopsy specimens
Systematic characterization of upper critical fields for MgB thin films using the two-band superconducting theory
We present experimental results of the upper critical fields of
various MgB thin films prepared by the molecular beam epitaxy,
multiple-targets sputtering, and co-evaporation deposition apparatus.
Experimental data of the are successfully analyzed by applying
the Gurevich theory of dirty two-band superconductivity in the case of
, where and are the intraband
electron diffusivities for and bands, respectively. We find that
the parameters obtained from the analysis are strongly correlated to the
superconducting transition temperature of the films. We also
discuss the anormalous narrowing of the transition width at intermediate
temperatures confirmed by the magnetoresistance measurements.Comment: 7 pages, 7 figures, submitted to Phys. Rev.
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