Zoledronic Acid Enhances Lipopolysaccharide-Stimulated Proinflammatory Reactions through Controlled Expression of SOCS1 in Macrophages

Bisphosphonate-related osteonecrosis of the jaw (BRONJ) is a serious side effect of nitrogen-containing bisphosphonate (NBP) use. Many studies have shown that BRONJ is limited to the jawbone and does not occur in the other bones. We hypothesized that BRONJ is related to local bacterial iections and involves the innate immune system. To examine the relationship between BRONJ and innate immunity, we examined the effects of NBPs on macrophages, one of the important cell types in innate immunity. The expression of toll-like receptor-4 (TLR4) in cells after pretreatment with zoledronic acid (ZOL) did not considerably differ from that in untreated control cells. However, cytokine levels and nitric oxide (NO) production increased after pretreatment with ZOL. Furthermore, ZOL induced NF-κB activation by enhancing IκB-α degradation. Lipopolysaccharide (LPS)-induced apoptosis also increased after pretreatment with ZOL. This effect was mediated by a reduction of suppressor of cytokine signaling-1 (SOCS1), which is a negative regulator of myeloid differentiation primary response gene 88 (MyD 88)-dependent signaling. These results suggest that ZOL induced excessive innate immune response and proinflammatory cytokine production and that these processes may be involved in the bone destruction observed in BRONJ

Ablation of Fbxw7 Eliminates Leukemia-Initiating Cells by Preventing Quiescence

SummaryImatinib eradicates dividing progenitor cells of chronic myeloid leukemia (CML) but does not effectively target nondividing leukemia-initiating cells (LICs); thus, the disease often relapse after its discontinuation. We now show that Fbxw7 plays a pivotal role in maintenance of quiescence in LICs of CML by reducing the level of c-Myc. Abrogation of quiescence in LICs by Fbxw7 ablation increased their sensitivity to imatinib, and the combination of Fbxw7 ablation with imatinib treatment resulted in a greater depletion of LICs than of normal hematopoietic stem cells in mice. Purging of LICs by targeting Fbxw7 to interrupt their quiescence and subsequent treatment with imatinib may thus provide the basis for a promising therapeutic approach to CML

A Lipid Bilayer Formed on a Hydrogel Bead for Single Ion Channel Recordings

Ion channel proteins play important roles in various cell functions, making them attractive drug targets. Artificial lipid bilayer recording is a technique used to measure the ion transport activities of channel proteins with high sensitivity and accuracy. However, the measurement efficiency is low. In order to improve the efficiency, we developed a method that allows us to form bilayers on a hydrogel bead and record channel currents promptly. We tested our system by measuring the activities of various types of channels, including gramicidin, alamethicin, alpha-hemolysin, a voltage-dependent anion channel 1 (VDAC1), a voltage- and calcium-activated large conductance potassium channel (BK channel), and a potassium channel from Streptomyces lividans (KcsA channel). We confirmed the ability for enhanced measurement efficiency and measurement system miniaturizion

Mechanistic dissection of premature translation termination induced by acidic residues-enriched nascent peptide

Ribosomes polymerize nascent peptides through repeated inter-subunit rearrangements between the classic and hybrid states. The peptidyl-tRNA, the intermediate species during translation elongation, stabi-lizes the translating ribosome to ensure robust continuity of elongation. However, the translation of acidic residue-rich sequences destabilizes the ribosome, leading to a stochastic premature translation cessation termed intrinsic ribosome destabilization (IRD), which is still ill-defined. Here, we dissect the molecular mechanisms underlying IRD in Escherichia coli. Reconstitution of the IRD event reveals that (1) the prolonged ribosome stalling enhances IRD-mediated translation discontinuation, (2) IRD depends on temperature, (3) the destabilized 70S ribosome complex is not necessarily split, and (4) the destabilized ribosome is subjected to peptidyl-tRNA hydrolase-mediated hydrolysis of the peptidyl-tRNA without subunit splitting or recycling factors-mediated subunit splitting. Collectively, our data indicate that the translation of acidic-rich sequences alters the conformation of the 70S ribosome to an aberrant state that allows the noncanonical pre-mature termination

Conditional inactivation of Fbxw7 impairs cell-cycle exit during T cell differentiation and results in lymphomatogenesis

Cell proliferation is strictly controlled during differentiation. In T cell development, the cell cycle is normally arrested at the CD4+CD8+ stage, but the mechanism underlying such differentiation-specific exit from the cell cycle has been unclear. Fbxw7 (also known as Fbw7, Sel-10, hCdc4, or hAgo), an F-box protein subunit of an SCF-type ubiquitin ligase complex, induces the degradation of positive regulators of the cell cycle, such as c-Myc, c-Jun, cyclin E, and Notch. FBXW7 is often mutated in a subset of human cancers. We have now achieved conditional inactivation of Fbxw7 in the T cell lineage of mice and found that the cell cycle is not arrested at the CD4+CD8+ stage in the homozygous mutant animals. The mutant mice manifested thymic hyperplasia as a result of c-Myc accumulation and eventually developed thymic lymphoma. In contrast, mature T cells of the mutant mice failed to proliferate in response to mitogenic stimulation and underwent apoptosis in association with accumulation of c-Myc and p53. These latter abnormalities were corrected by deletion of p53. Our results suggest that Fbxw7 regulates the cell cycle in a differentiation-dependent manner, with its loss resulting in c-Myc accumulation that leads to hyperproliferation in immature T cells but to p53-dependent cell-cycle arrest and apoptosis in mature T cells

The relationship between the PD-L1 expression of surgically resected and fine-needle aspiration specimens for patients with pancreatic cancer

BACKGROUND: Recently, therapeutic antibodies against programmed death-1/programmed death-ligand 1 (PD-1/PD-L1) have shown promising clinical results for several solid tumors, including pancreatic cancer. In this study, we evaluated the relationship between the PD-L1 expression of surgical resected and fine-needle aspiration (FNA) specimens for patients with pancreatic cancer. METHODS: Of 121 patients who underwent endoscopic ultrasound-guided (EUS)-FNA before surgery for pancreatic cancer in an academic center, the 94 (78%) with adequate FNA specimens for a histological evaluation were retrospectively analyzed. All the patients had undergone upfront surgery without any chemotherapy or radiotherapy. We performed immunohistochemistry (IHC) staining to investigate the PD-L1 expression in both resected and FNA specimens. The positive-stained cells were counted, and their percentage was used for the investigation. RESULTS: Of the 94 patients, 16 (17%) and 11 (10%) were defined as positive on resected cancer specimens using cutoff points of 5% and 10% positively stained cancer cell counts, respectively. The concordance rates for the positive frequency of PD-L1 expression between resected and FNA specimens were 44% (7/16) and 55% (6/11) when the positivity was set to ≥ 5% and ≥ 10%, respectively. The concordance rates for the negative frequency of PD-L1 expression between two specimens were 97% (76/78) and 99% (82/83) when the positivity was set to ≥ 5% and ≥ 10%, respectively. CONCLUSIONS: Approximately, half of the patients with PD-L1 expression positive and almost all the patients with PD-L1 expression negative could be diagnosed on FNA specimens

The Hearing Outcomes of Cochlear Implantation in Waardenburg Syndrome

Objectives. This study aimed to determine the feasibility of cochlear implantation for sensorineural hearing loss in patients with Waardenburg syndrome. Method. A retrospective chart review was performed on patients who underwent cochlear implantation at the University of Tokyo Hospital. Clinical classification, genetic mutation, clinical course, preoperative hearing threshold, highresolution computed tomography of the temporal bone, and postoperative hearing outcome were assessed. Result. Five children with Waardenburg syndrome underwent cochlear implantation. The average age at implantation was 2 years 11 months (ranging from 1 year 9 months to 6 years 3 months). Four patients had congenital profound hearing loss and one patient had progressive hearing loss. Two patients had an inner ear malformation of cochlear incomplete partition type 2. No surgical complication or difficulty was seen in any patient. All patients showed good hearing outcome postoperatively. Conclusion. Cochlear implantation could be a good treatment option for Waardenburg syndrome

Successful Treatment for Hepatic Encephalopathy Aggravated by Portal Vein Thrombosis with Balloon-Occluded Retrograde Transvenous Obliteration

This report presents the case of a 78-year-old female with hepatic encephalopathy due to an inferior mesenteric venous-inferior vena cava shunt. She developed hepatocellular carcinoma affected by hepatitis C virus-related cirrhosis and underwent posterior sectionectomy. Portal vein thrombosis developed and the portal trunk was narrowed after hepatectomy. Portal vein thrombosis resulted in high portal pressure and increased blood flow in an inferior mesenteric venous-inferior vena cava shunt, and hepatic encephalopathy with hyperammonemia was aggravated. The hepatic encephalopathy aggravated by portal vein thrombosis was successfully treated by balloon-occluded retrograde transvenous obliteration via a right transjugular venous approach without the development of other collateral vessels