Abstract Ligands such as enzyme inhibitors stabilize the native conformation of a protein upon binding to the native state, but some compounds destabilize the native conformation upon binding to the non‐native state. The former ligands are termed “stabilizer chaperones” and the latter ones “destabilizer chaperones.” Because the stabilization effects are essential for the medical chaperone (MC) hypothesis, here we have formulated a thermodynamic system consisting of a ligand and a protein in its native‐ and non‐native state. Using the differential scanning fluorimetry and the circular dichroism varying the urea concentration and temperature, we found that when the coenzyme NADP + was absent, inhibitors such as isolithocholic acid stabilized the aldo–keto reductase AKR1A1 upon binding, which showed actually the three‐state folding, but destabilized AKR1B10. In contrast, in the presence of NADP + , they destabilized AKR1A1 and stabilized AKR1B10. To explain these phenomena, we decomposed the free energy of stabilization (ΔΔ G ) into its enthalpy (ΔΔ H ) and entropy (ΔΔ S ) components. Then we found that in a relatively unstable protein showing the three‐state folding, native conformation was stabilized by the negative ΔΔ H in association with the negative ΔΔ S , suggesting that the stabilizer chaperon decreases the conformational fluctuation of the target protein or increase its hydration. However, in other cases, ΔΔ G was essentially determined by the delicate balance between ΔΔ H and ΔΔ S . The proposed thermodynamic formalism is applicable to the system including multiple ligands with allosteric interactions. These findings would promote the development of screening strategies for MCs to regulate the target conformations.
Abstract Background: ESCC(Esophageal Squamous Cell Carcinoma) is highly aggressive due to its tendency to metastasize to the lymph nodes and organs. Our laboratory previously reported that the exosome amount in the peripheral blood could predict the prognosis of ESCC patients. CD63 is a tetraspanin family protein and is often used as a marker of exosome.CD63 highly express in early stage melanoma and thought to be a suppressive factor against EMT (epithelial-to-mesenchymal transition) in melanoma. On the other hand, some report confirmed CD63 as a prometastatic factor via regulating E cadherin expression. The function of CD63 are still controversial. We herein assessed CD63 expression and clinicopathological findings in ESCCpatient, and assessed molecular roles of CD63 in ESCC cell lines. Materials and methods: The relationship between the CD63 expression in the resected ESCC specimen (from 1997 to 2006, n=86) and clinicathological features were assessed using immunohistochemical staining. Human ESCC cell lines (TE2,TE15) were used as high CD63 expression cell lines for in vitro analysis. CD63 was knockdown using siRNA, and CD63 down regulate was confirmed by western blot and PCR. The influence on the cell behavior and gene expressions were assessed by cell proliferation assay, mRNA microarray, and GSEA(Gene Set Enrichment Analysis). Results: There were no statistically significant correlation between the CD63 expression and age, sex, tumor depth (T), lymph node metastasis (N), distant organ metastasis (M), differentiation of tumor, lymphatic vessel invasion (ly), venous invasion (v), the type of progression. As for the prognosis, the high CD63 expression patients have significantly poorer prognosis than the low expression of CD63 patients. (P=0.047, log rank test). In vitro study, cell proliferation assay showed down expression of CD63 reduce cell proliferation. Knock down of CD63 downregulates HER2 expression and influence on other ERBB signaling pathways. Conclusions: High CD63 expression predicts poor prognosis in human ESCC. The molecular function of CD63 could have relationship to ERBB signaling pathways in human ESCC cells. Citation Format: Yasunori Matsumoto, Masayuki Kano, Kentaro Murakami, Satoshi Endo, Takeshi Toyozumi, Tadashi Shiraishi, Toshiki Kamata, Takahiro Ryuzaki, Kazuya Kinoshita, Soichiro Hirasawa, Hisahiro Matsubara. Clinical significance of tetraspanin CD63 in human ESCC [abstract]. In: Proceedings of the Annual Meeting of the American Association for Cancer Research 2020; 2020 Apr 27-28 and Jun 22-24. Philadelphia (PA): AACR; Cancer Res 2020;80(16 Suppl):Abstract nr 5444.
Infection is one of the serious complications seen in the management of RA patients. The acute inflammatory marker C-reactive protein (CRP) is elevated both during infection and during high disease activity of RA, and this often poses a problem when distinguishing the two. The soluble CD14 subtype, presepsin has been reported to be a novel effective marker for the diagnosis of sepsis but has not been evaluated in RA patients.
Objectives
To evaluate the use of presepsin in RA patients during an infectious event.
Methods
25 RA patients with infections, 21 RA patients with high disease activity, 23 healthy controls (HC) were enrolled in this study. RA patients in whom the pathogens were identified (22 bacterias, 2 viruses, and 1 M. tuberculosis) were designated as the infection RA group (iRA), high disease activity RA patients without infection were designated as the flare RA group (fRA). Presepsin was measured using a chemiluminescent enzyme immunoassay. CRP and procalcitonin (PCT) were also measured. RA disease activity was evaluated using DAS28-CRP. Levels of respective measurements at both pre- and post-treatment were analyzed using the Wilcoxon signed-rank test, and comparisons of levels within each group were analyzed using the Mann-Whitney's U-test. Additionally, Spearman's rank correlation coefficient was used to analyze the correlation of levels of presepsin, CRP, and PCT in iRA and correlation of presepsin, DAS28-CRP, and CRP in fRA. Further, AUC was obtained from the ROC analysis. Treatment for iRA included antibiotics, antivirals, and treatment for fRA included corticosteroids, DMARDs, and biologics.
Results
In fRA, average level of CRP was 2.4±2.1mg/dl, DAS28-CRP was 4.2±1.31. At pre-treatment, levels of presepsin in iRA (2088.4±4243.7pg/ml) was significantly higher compared to in fRA (319.3±321.8pg/ml, p<0.01). Both levels were significantly higher compared to those in HC (136±57.0pg/ml). In iRA, presepsin level correlated with CRP (r=0.65, p<0.01) and PCT (r=0.48, p<0.05). In fRA, presepsin level did not correlate with CRP or DAS28-CRP. After treatment, levels of prepsin (p<0.001), CRP (p<0.001), and PCT (p<0.001) were significant decreased in iRA. On the other hand, in fRA, CRP (p<0.001) and DAS28-CRP (p<0.001) were significantly decreased after treatment, however presepsin level showed no significant change (p=0.37). Furthermore, presepsin levels in fRA with low disase activity after treatment were significantly higher compared to those in HC (p<0.01). ROC analysis of iRA showed that AUC levels for presepsin was 0.817, indicating the efficacy of presepsin for diagnosis of infection in RA.
Conclusions
Presepsin is an effective diagnostic marker for infection in RA patients.
References
Y. Yaegashi, et al., J Infect Chemother 2005;11:234-238 T. Shozushima, et al., J Infect Chemother 2011;17:764-769
Chemoresistance is a serious issue in the therapy of many cancers, but the molecular mechanism is little understood. The mRNA level of occludin (OCLN), a tight junctional protein, was increased in the cisplatin (CDDP), doxorubicin (DXR), 7-ethyl-10-hydroxy-camptothecin, or gemcitabine-resistant human lung adenocarcinoma A549 cells. Here, we investigated the regulatory mechanism and pathophysiological role of OCLN. OCLN was mainly localized at tight junctions in A549 and CDDP-resistant A549 (A549/CDDP) cells. The level of p-Akt in A549/CDDP cells was higher than that in A549 cells, and the mRNA and protein levels of OCLN were suppressed by a phosphoinositide 3-kinase (PI3K)/Akt pathway inhibitor, LY-294002, suggesting that a PI3K/Akt pathway is involved in the elevation of OCLN expression. The overexpression of OCLN in A549 cells decreased paracellular permeability to DXR. Cytotoxicity to CDDP was unaffected by OCLN-overexpression in 2D culture model. In 3D culture model, the spheroid size, hypoxic level, and cell viability were significantly elevated by CDDP resistance, but not by OCLN-overexpression. The accumulation inside the spheroids and toxicity of DXR were correlated with OCLN expression. Our data suggest that OCLN is not directly involved in the chemoresistance, but it enhances chemoresistance mediated by suppression of accumulation of anticancer drugs inside the spheroids.
Fifteen cases of traumatic thoracic aortic rupture (TAR) were treated at St. Marianna University Hospital from December 1980 to July 1995. Causes of TAR were due to vehicle accidents in 14 patients and fall in one patient. On diagnosis, contrast-enhanced CT scan was routinely performed in the patients with blunt chest trauma associated with superior mediastinal widening, loss of the aortic knob or right shift of the trachea on the initial roentgenogram. When CT scan demonstrated specific signs for TAR, pseudoaneurysm formation and/or extravasation of the contrast dye, aortography was eliminated before operation. As a role, operation was performed on an emergency basis as soon as the diagnosis was confirmed. Four cases died due to intrapleural rupture before or immediately after thoracotomy. Nine (82%) of the 11 patients in whom operation was completed survived and are doing well. In one of the 4 patients who underwent operation with simple aortic cross-clamping; paraplegia developed after 30 minutes of spinal ischemia. Left heart bypass with the Bio-Pump without heparin or with an antithrombin agent, argatroban, was used in recent 6 patients. Use of left heart bypass with the Bio-Pump without anticoagulant or with argatroban appears to be promising as a safe adjunct in the repair of TAR, preventing fatal bleeding of other injured organs.
Identifying accurate biomarkers for predicting response to chemoradiotherapy (CRT) in patients with esophageal squamous cell carcinoma (ESCC) is a critical challenge. The protein SIRT1, recognized for its implications in longevity, has been associated with tumor promotion in ESCC. However, data regarding its correlation with CRT sensitivity remain unreported. Therefore, in this study, we aimed to investigate the relationship between SIRT1 expression and CRT sensitivity and concurrently assess the effect of SIRT1 knockdown on CRT sensitivity in ESCC.
Abstract The antiproton is a basic constituent of antimatter and required for stringent matter-antimatter comparisons to test the fundamental charge-parity-time (CPT) reversal invariance in the Standard Model of particle physics (1). Using low energy antiprotons, only available at the antimatter factory (AMF) located at CERN (2), such tests have been realized for example in the high-precision spectroscopy of antiprotonic atoms (3), and antihydrogen (4). In our cryogenic Penning-trap experiments (5), we measure the fundamental properties of protons and antiprotons and conduct CPT tests comparing their magnetic moments with a precision of 1.5 parts per billion (6, 7), as well as the most precise test of CPT invariance in the baryon sector by comparing their charge-to-mass ratios to a relative uncertainty of 16 parts-per-trillion(8). Although innovative shielding systems have been implemented (9), our experiments are limited by magnetic field fluctuations imposed by the accelerators in the AMF. To push the limits of our measurements, we are advancing the relocation of antiprotons to dedicated precision laboratories. This work presents a critical milestone in this endeavor: the successful transport of a trapped proton cloud from the AMF using BASE-STEP (10) — a transportable, superconducting, persistent, autonomous, and open Penning-trap system. We transferred the trapped protons from our experimental area at the AMF onto a truck and transported them across CERN’s Meyrin site. We demonstrated loss-free proton relocation, sustaining autonomous operation without external power for four hours, thereby confirming the feasibility of transferring particles to low-noise laboratory environments. The transport range of this system can be extended using mobile power generators (11) to reach laboratories throughout Europe. Our achievement represents a breakthrough and a potential start of a new era in precision antimatter research by conducting antiproton spectroscopy in low-noise laboratories. It also enables transportation and offline studies of other exotic ions, such as highly-charged ions produced in accelerators (12) or high-end EBITs (13), and the charged antimatter ions H¯ + (14) and H¯2 (15)
