25 research outputs found
Construction and Superfunction of Metal-oxide Nanostructures and Interfaces(Interfaces by various techniques)
Metal oxides show such versatile properties as high T_C superconductivity, ferroelectricity, colossal magnetoresistance and non-linear optical properties. By developing laser molecular beam epitaxy, we have been working on atomic scale control for the heteroepitaxy of these materials in order to explore a novel field of "oxide electronics", in which monolithically integrated devices composed of epitaxially grown oxide nanostructures show outstanding performances that Si-based semiconducting devices would not be able to give. Among many topics we have, we concentrate on Josephson tunnel junction made out of high T_C superconductors and ultra-violet laser emission from ZnO nanocrystal films
STAP-2 interacts with Pyk2 and enhances Pyk2 activity in T-cells
STAP-2 is an adaptor molecule regulating several signaling pathways, including TLRs and cytokine/chemokine receptors in immune cells. We previously reported that STAP-2 enhances SDF-1 a-induced Vavl/Racl-mediated T-cell chemotaxis. However, the detailed mechanisms of STAP-2 involvement in enhancing T-cell chemotaxis remain unknown. In the present study, we demonstrate that STAP-2 directly interacts with Pyk2, which is a key molecule in the regulation of SDF-la/CXCR4-mediated T-cell chemotaxis, and increases phosphorylation of Pyk2. Pyk2 itself can induce STAP-2 Y250 phosphorylation, and this phosphorylation is critical for maximal interactions between STAP-2 and Pyk2. Finally, SDF-1 a induced T-cell chemotaxis is inhibited by treatment with Pyk2 siRNA or AG17, an inhibitor of Pyk2, in Jurkat cells overexpressing STAP-2. Taken together, the Pyk2/STAP-2 interaction is a novel mechanism to regulate SDF-1 alpha-dependent T-cell chemotaxis
The Notch inhibitor cowanin accelerates nicastrin degradation
Abstract Aberrant activation of Notch signaling contributes to the pathogenesis of several different types of cancer, and Notch pathway inhibitors may have significant therapeutic potential. Using a unique cell-based assay system, we isolated twelve compounds, including one new natural product from Garcinia speciosa, that inhibit the Notch signaling pathway. HES1 and HES5 are target genes of the Notch cascade, and compound 2, referred to as cowanin, decreased the protein levels of HES1 and HES5 in assay cells. Furthermore, cowanin (2) showed potent cytotoxicity against human leukemic HPB-ALL cells. The Notch signaling inhibitory activity of cowanin (2) is linked to the increased degradation of nicastrin, which is one of the components of the γ-secretase complex. To the best of our knowledge, this is the first example of a compound with Notch pathway inhibitory activity mediated by nicastrin degradation
Secondary bladder amyloidosis with familial Mediterranean fever in a living donor kidney transplant recipient: a case report
Background Secondary bladder amyloidosis is an extremely rare disease, resulting from a chronic systematic inflammatory disorder associated with amyloid deposits. Although uncommon in Japan, familial Mediterranean fever (FMF) is a hereditary autoinflammatory disease characterized by recurrent episodes of fever of short duration and serositis and is frequently associated with systemic amyloidosis. Here, we present a case of a Japanese patient complaining of fever and macroscopic hematuria after a living donor renal transplantation. Consequently, he was diagnosed with secondary bladder amyloidosis with FMF. Case presentation A 64-year-old Japanese male received a living ABO-incompatible kidney transplant from his wife. The postoperative clinical course was normal, and the patient was discharged 21 days after the transplantation with a serum creatinine level of 0.78 mg/dl. The patient frequently complained of general fatigue and fever of unknown origin. Six months later, the patient presented with continuous general fatigue, macroscopic hematuria, and fever. Cystoscopic examination of the bladder showed an edematous region with bleeding, and a transurethral biopsy revealed amyloid deposits. His wife stated that the patient had a recurrent high fever since the age of 40 years and that his younger brother was suspected to have a familial autoinflammatory syndrome; thus, the patient was also suspected to have a familial autoinflammatory syndrome. Based on his brother’s medical history and the genetic tests, which showed a homozygous mutation (M694V/M694V) for the Mediterranean fever protein, he was diagnosed with FMF. Although colchicine treatment for FMF was planned, the patient had an untimely death due to heart failure. We re-evaluated the pathological findings of the various tissue biopsies obtained during the treatment after the renal transplantation. Immunohistochemistry revealed amyloid deposits in the bladder region, renal allograft, and myocardium and the condition was diagnosed as AA amyloidosis associated with FMF. Conclusion We presented a case of systemic amyloidosis with FMF, involving the bladder region, myocardium, and renal allograft, diagnosed after renal transplantation. Bladder amyloidosis should be considered in patients with macroscopic hematuria, particularly in the kidney transplant recipients with idiopathic chronic renal disease. Diagnosis of secondary bladder amyloidosis may result in the early detection of underlying diseases, which may contribute to patient prognosis