OP0027 ASSOCIATION BETWEEN BASELINE CARDIOVASCULAR RISK AND INCIDENCE RATES OF MAJOR ADVERSE CARDIOVASCULAR EVENTS AND MALIGNANCIES IN PATIENTS WITH PSORIATIC ARTHRITIS AND PSORIASIS RECEIVING TOFACITINIB

Background

Common comorbidities of psoriatic arthritis (PsA) and psoriasis (PsO) are cardiovascular (CV) disease and metabolic syndrome (MetS).1,2 Risk of CV disease may be associated with increased risk of future malignancies.3 Tofacitinib is a JAK inhibitor for treatment of PsA and has been investigated for treatment of PsO.

Objectives

To examine baseline (BL) CV risk and its association with incidence rates (IRs) of major adverse CV events (MACE) and malignancies in tofacitinib-treated patients (pts) with PsA and PsO.

Methods

Analysis included data from 3 (Phase [P]3/long-term extension [LTE]) trials of pts with PsA and 7 (P2/3/LTE) trials of pts with PsO receiving ≥1 dose of tofacitinib (5 or 10 mg twice daily). IRs (pts with events/100 pt-yrs) for MACE and malignancies (excluding non-melanoma skin cancer) were stratified by: history of coronary artery disease (HxCAD [≥1 of myocardial infarction, coronary heart disease, coronary artery procedure or stable angina pectoris]); BL 10-yr atherosclerotic CV disease (ASCVD) risk (ASCVD-pooled cohort equations calculator [only in pts without HxCAD]); and BL MetS (≥3 of hypertension, raised triglycerides, reduced high-density lipoprotein cholesterol, high waist circumference or high fasting glucose levels).

Results

Of 783 and 3663 pts with PsA and PsO, total tofacitinib exposure was 2038 and 8950 pt-yrs, and median duration of exposure was 3.0 and 2.4 yrs, respectively. In pts with PsA and PsO, 5.0% and 2.5% had HxCAD, respectively; in those without HxCAD, >20% had intermediate/high BL 10-yr ASCVD risk (Figure 1). At BL, 40.9% and 32.7% of pts with PsA and PsO had MetS, respectively. IRs of MACE were greatest in pts with PsA and PsO who had HxCAD/high BL 10-yr ASCVD risk (Table 1). In the PsA cohort, 5/6 pts with MACE had BL MetS. IRs of malignancies in pts with PsA were greatest in those with intermediate/high BL 10-yr ASCVD risk; 8/9 pts with malignancies in these risk categories had BL MetS (Table 1). In the PsO cohort, IR of malignancies was notably greater in those with high vs low/intermediate BL 10-yr ASCVD risk (Table 1).

Table 1.

IRs of MACE and malignancies in pts with PsA and PsO receiving tofacitinib, stratified by HxCAD, BL 10-yr ASCVD risk and BL MetS

MACEMalignanciesPsAPsOPsAPsOn/N[n1]IR (95% CI)n/N[n1]IR (95% CI)n/N[n1]IR (95% CI)n/N[n1]IR (95% CI)HxCADYes1/39[0]0.97 (0.02, 5.38)3/93[0]1.49 (0.31, 4.36)0/39[0]0.00 (0.00, 3.52)0/93[0]0.00 (0.00, 1.83)No5/744[5]0.25 (0.08, 0.59)20/3570[10]0.22 (0.13, 0.34)15/744[10]0.75 (0.42, 1.24)60/3570[26]0.66 (0.51, 0.85)BL 10-yr ASCVD risk categoryHigh risk (≥20%)1/35[1]1.26 (0.03, 7.01)7/179[4]1.67 (0.67, 3.43)1/35[1]1.26 (0.03, 7.03)15/179[10]3.57 (2.00, 5.89)Intermediate risk(≥7.5–<20%)2/121[2]0.62 (0.07, 2.23)9/716[6]0.50 (0.23, 0.95)8/121[7]2.46 (1.06, 4.86)23/716[9]1.28 (0.81, 1.92)Borderline risk(≥5–<7.5%)1/91[1]0.42 (0.01, 2.32)2/400[0]0.19 (0.02, 0.67)2/91[1]0.83 (0.10, 3.01)5/400[1]0.47 (0.15, 1.09)Low risk (<5%)1/487[1]0.08 (0.00, 0.42)2/2241[0]0.03 (0.00, 0.13)4/487[1]0.30 (0.08, 0.77)17/2241[6]0.30 (0.17, 0.47)BL MetSYes5/3200.60 (0.20, 1.40)10/11970.34 (0.16, 0.63)10/3201.20 (0.58, 2.21)26/11970.89 (0.58, 1.31)No1/4630.08 (0.00, 0.44)13/24660.20 (0.11, 0.35)5/4630.40 (0.13, 0.92)34/24660.54 (0.37, 0.75)

Follow-up time calculated up to the day of the first event and subject to risk period of 28 days beyond the last dose of study drug.

CI, confidence interval; N, total pts; n, pts with MACE/malignancies; n1, pts with MACE/malignancies and BL MetS.

Conclusion

In tofacitinib-treated pts with PsA and PsO, raised CV risk and MetS at BL were potentially associated with higher IRs of MACE and malignancies. Our findings support assessing CV risk in pts with PsA and PsO and enhanced monitoring for malignancies in those with raised CV risk.

References

[1]Karmacharya et al. Ther Adv Musculoskel Dis 2021; 13: 1-15.

[2]Garshick et al. J Am Coll Cardiol 2021; 77: 1670-1680.

[3]Lau et al. JACC CardioOncol 2021; 3: 48-58.

Acknowledgements

Study sponsored by Pfizer Inc. Medical writing support was provided by Emma Mitchell, CMC Connect, and funded by Pfizer Inc.

Disclosure of Interests

Lars Erik Kristensen Speakers bureau: AbbVie, Amgen, Biogen, Bristol-Myers Squibb, Eli Lilly, Janssen, MSD, Novartis, Pfizer Inc and UCB, Grant/research support from: Biogen, Janssen, Novartis and UCB, Bruce Strober Speakers bureau: AbbVie, Amgen, Eli Lilly, Janssen and Ortho Dermatologics, Consultant of: AbbVie, Almirall, Amgen, Arcutis, Arena, Aristea, Boehringer Ingelheim, Bristol-Myers Squibb, Cara, Celgene, Dermavant, Dermira, Eli Lilly, GlaxoSmithKline, Janssen, Leo, Meiji Seika Pharma, Novartis, Ortho Dermatologics, Pfizer Inc, Regeneron, Sanofi-Genzyme, Sun Pharma and UCB, Denis Poddubnyy Speakers bureau: AbbVie, Bristol-Myers Squibb, Eli Lilly, MSD, Novartis, Pfizer Inc and UCB, Consultant of: AbbVie, BIOCAD, Gilead Sciences, GlaxoSmithKline, Eli Lilly, MSD, Novartis, Pfizer Inc, Samsung Bioepis and UCB, Grant/research support from: AbbVie, MSD, Novartis and Pfizer, Ying Ying Leung Consultant of: AbbVie, Eli Lilly, Janssen and Novartis, Hyejin Jo Consultant of: Pfizer Inc, Employee of: Syneos Health, Kenneth Kwok Shareholder of: Pfizer Inc, Employee of: Pfizer Inc, Ivana Vranic Shareholder of: Pfizer Inc, Employee of: Pfizer Ltd, Dona Fleishaker Shareholder of: Pfizer Inc, Employee of: Pfizer Inc, Lara Fallon Shareholder of: Pfizer Inc, Employee of: Pfizer Inc, Arne Yndestad Shareholder of: Pfizer Inc, Employee of: Pfizer Inc, Dafna D Gladman Consultant of: AbbVie, Amgen, Celgene, Eli Lilly, Galapagos, Gilead Sciences, Janssen, Novartis, Pfizer Inc and UCB.

AB0248 INFLUENZA ADVERSE EVENTS IN PATIENTS WITH RHEUMATOID ARTHRITIS IN THE TOFACITINIB CLINICAL PROGRAMME

Background:

Patients (pts) with rheumatoid arthritis (RA) have an increased susceptibility to seasonal influenza and its complications.1 In light of the COVID-19 pandemic, there is a need to better understand acute respiratory viral RNA infections, such as influenza, in pts with RA.

Objectives:

To present a comprehensive summary of data on influenza adverse events (AEs) occurring in the tofacitinib RA clinical programme.

Methods:

Influenza AEs were evaluated in pts with RA from 21 Phase (P)1–3b/4 trials and two open-label, long-term extension (LTE) studies from 2005–2019. These were analysed as two cohorts: P2–3b/4 cohort (pts who received tofacitinib 5 or 10 mg twice daily [BID] as monotherapy or with conventional synthetic [cs]DMARDs, adalimumab, methotrexate or placebo, in P2–3b/4 controlled studies) and Overall cohort (pts who received ≥1 tofacitinib dose, as monotherapy or with csDMARDs, in P1–3b/4 and LTE studies; data were summarised by average tofacitinib dose [average tofacitinib 5 or 10 mg BID based on average total daily dose of <15 or ≥15 mg, respectively]). Incidence rates (IRs; unique pts with events/100 pt-years of exposure; censored at day of first event or up to last dose +28 days) were evaluated for influenza AEs, influenza complication AEs, influenza-like illness (all composites of several MedDRA preferred/verbatim terms) and overall influenza AEs (composite of all preferred/verbatim terms included under influenza AEs, influenza complication AEs and influenza-like illness). In the Overall cohort, the incidence of serious non-influenza AEs within 28 days of the start of an overall influenza AE and time taken to resolution of overall influenza AEs by action taken were summarised descriptively.

Results:

In total, 7964 pts were included; 517 (6.5%) pts reported overall influenza AEs, three of which occurred outside the risk period. In the P2–3b/4 cohort (N=6690), IRs for influenza AEs, influenza-like illness and overall influenza AEs generally appeared similar across treatment arms (Figure 1a). In the Overall cohort, IRs for influenza AEs and influenza-like illness were similar between tofacitinib doses (Figure 1b), and IRs for overall influenza AEs were similar between tofacitinib doses and pt age groups (Figure 1c). No influenza complication AEs (eg pneumonia/encephalitis influenzal) were reported in either cohort. Among pts with overall influenza AEs, nine (1.7%) had serious overall influenza AEs (average tofacitinib 5 mg BID, n=6; average tofacitinib 10 mg BID, n=3). Of these pts, eight (1.5%) were hospitalised (average tofacitinib 5 mg BID, n=6; average tofacitinib 10 mg BID, n=2) and two (0.4%) died (average tofacitinib 5 mg BID, n=1; average tofacitinib 10 mg BID, n=1). Both deaths occurred in pts with H1N1 Influenza A. Twelve (2.3%) pts had a serious non-influenza AE within 28 days of the start of the overall influenza AE (average tofacitinib 5 mg BID, n=6; average tofacitinib 10 mg BID, n=6). The most common serious non-influenza AEs (one event each in average tofacitinib 5 and 10 mg BID groups) were acute respiratory distress syndrome and pneumonia. In most pts with overall influenza AEs, no change to tofacitinib treatment was made (70.2%, n=363) or treatment was stopped temporarily (28.2%, n=146) for a mean duration of 11.0 days. The mean number of days to resolution of overall influenza AEs was numerically similar, ranging from 10.4–11.8 days across tofacitinib doses, irrespective of these actions.

Conclusion:

This post hoc analysis of influenza AEs across the tofacitinib RA clinical programme, over 14–15 influenza seasons, showed generally similar rates between treatment groups, and between tofacitinib doses and pt age groups. Limitations include varying exposure across treatment arms in the P2–3b/4 cohort. Most influenza AEs were non-serious (98.3%), and were not associated with changes to tofacitinib treatment.

References:

[1]Blumentals et al. BMC Musculoskelet Disord 2012; 13: 158.

Acknowledgements:

Study sponsored by Pfizer Inc. Medical writing support was provided by Kirsten Woollcott, CMC Connect, and funded by Pfizer Inc.

Disclosure of Interests:

Kevin Winthrop Grant/research support from: AbbVie, Bristol-Myers Squibb, Eli Lilly, Galapagos, Gilead Sciences, Pfizer Inc, Roche, UCB, Arne Yndestad Shareholder of: Pfizer Inc, Employee of: Pfizer Inc, Dan Henrohn Shareholder of: Pfizer Inc, Employee of: Pfizer Inc, Hyejin Jo Consultant of: Pfizer Inc, Employee of: Syneos Health, Sara Marsal Shareholder of: IMIDomics, Consultant of: AbbVie, Celgene, Galapagos, Gilead Sciences, Pfizer Inc, Sandoz, Sanofi, Grant/research support from: AbbVie, Bristol-Myers Squibb, Celgene, Jansen-Cilag, MSD, Novartis, Pfizer Inc, Roche, Sandoz, Sanofi, UCB, María Galindo-Izquierdo Grant/research support from: AbbVie, Eli Lilly, GSK, Janssen-Cilag, Annette Diehl Shareholder of: Pfizer Inc, Employee of: Pfizer Inc, Andrea Shapiro Shareholder of: Pfizer Inc, Employee of: Pfizer Inc, Stanley B. Cohen Consultant of: AbbVie, Eli Lilly, Genentech, Gilead Sciences, Pfizer Inc, Grant/research support from: AbbVie, Eli Lilly, Genentech, Gilead Sciences, Pfizer Inc

A Rapid Colorimetric Sensor for Soluble Interleukin-2 Receptor α, Based on Aptamer-Adsorbed AuNP

The soluble interleukin-2 receptor α (sIL-2Rα) is a broad indicator of clinical disease activity in various inflammatory diseases. Here we have developed, for the first time, a rapid, washing-free colorimetric aptasensor based on a sIL-2Rα aptamer (K_d =1.33 nm). The aptasensor was fabricated with Au nanoparticles (AuNPs) adsorbing sIL-2Rα aptamers. On addition of sIL-2Rα, the aptamers become desorbed from the AuNPs, and this in turn weakens the absorption corresponding to AuNP-catalyzed oxidation of ortho-phenylenediamine (oPD) with H₂ O₂ . The aptasensor was characterized by TEM imaging, ζ potential measurements, dynamic light scattering (DLS) analysis, and UV/Vis spectrometry, followed by further optimization. The fabricated sensor exhibited great analytical performance, with a linear range of 1 to 100 nm and a detection limit of 1 nm both in buffer and in spiked human serum within 25 min. Other proteins, such as bovine serum albumin (BSA), IL-17Rα, IL-5Rα, IL-13Rα₂ , and CD166, showed negligible effects on the aptasensor. Thanks to the great advantages of the aptamers and AuNPs, this aptasensor provides a rapid, simple, and inexpensive process that might offer insights into various diagnostic applications of sIL-2Rα.

Translational control of phloem development by RNA G-quadruplex-JULGI determines plant sink strength

The emergence of a plant vascular system was a prerequisite for the colonization of land; however, it is unclear how the photosynthate transporting system was established during plant evolution. Here, we identify a novel translational regulatory module for phloem development involving the zinc-finger protein JULGI (JUL) and its targets, the 5' untranslated regions (UTRs) of the SUPPRESSOR OF MAX2 1-LIKE4/5 (SMXL4/5) mRNAs, which is exclusively conserved in vascular plants. JUL directly binds and induces an RNA G-quadruplex in the 5' UTR of SMXL4/5, which are key promoters of phloem differentiation. We show that RNA G-quadruplex formation suppresses SMXL4/5 translation and restricts phloem differentiation. In turn, JUL deficiency promotes phloem formation and strikingly increases sink strength per seed. We propose that the translational regulation by the JUL/5' UTR G-quadruplex module is a major determinant of phloem establishment, thereby determining carbon allocation to sink tissues, and that this mechanism was a key invention during the emergence of vascular plants.

Development and MPI tracking of novel hypoxia-targeted theranostic exosomes

Treating the hypoxic region of the tumor remains a significant challenge. The goals of this study are to develop an exosome platform that can target regions of tumor hypoxia and that can be monitored in vivo using magnetic particle imaging (MPI). Four types of exosomes (generated under hypoxic or normoxic conditions, and with or without exposure to X-ray radiation) were isolated from MDA-MB-231 human breast cancer cells. Exosomes were labeled by DiO, a fluorescent lipophilic tracer, to quantify their uptake by hypoxic cancer cells. Subsequently, the exosomes were modified to carry SPIO (superparamagnetic iron oxide) nanoparticles and Olaparib (PARP inhibitor). FACS and fluorescence microscopy showed that hypoxic cells preferentially take up exosomes released by hypoxic cells, compared with other exosome formulations. In addition, the distribution of SPIO-labeled exosomes was successively imaged in vivo using MPI. Finally, the therapeutic efficacy of Olaparib-loaded exosomes was demonstrated by increased apoptosis and slower tumor growth in vivo. Our novel theranostic platform could be used as an effective strategy to monitor exosomes in vivo and deliver therapeutics to hypoxic tumors.

Highly sensitive amperometric detection of cardiac troponin I using sandwich aptamers and screen-printed carbon electrodes

In this study, we developed a sandwich aptamer-based screen-printed carbon electrode (SPCE) using chronoamperometry for the detection of cardiac troponin I (cTnI), one of the promising biomarkers for acute myocardial infarction (AMI). Disposable three-electrode SPCEs were manufactured using a screen printer, and various modifications such as electrodeposition of gold nanoparticles and electropolymerization of conductive polymers were performed. From the bare electrode to the aptamer-immobilized SPCE, all processes were monitored and analyzed via various techniques such as cyclic voltammetry, electrochemical impedance spectroscopy, and X-ray photoelectron spectroscopy. The quantification of cTnI was conducted based on amperometric signals from the catalytic reaction between hydrazine and H₂O₂. The fabricated aptasensor in a buffer, as well as in a serum-added solution, exhibited great analytical performance with a dynamic range of 1-100 pM (0.024-2.4ng/mL) and a detection limit of 1.0 pM (24pg/mL), which is lower than the existing cutoff values (40-700pg/mL). Furthermore, the developed sensor showed high sensitivity to cTnI over other proteins. It is anticipated that this potable SPCE aptasensor for cTnI will become an innovative diagnostic tool for AMI.

Extracellular ATP Induces Calcium Signaling in Odontoblasts

Odontoblasts form dentin at the outermost surface of tooth pulp. An increasing level of evidence in recent years, along with their locational advantage, implicates odontoblasts as a secondary role as sensory or immune cells. Extracellular adenosine triphosphate (ATP) is a well-characterized signaling molecule in the neuronal and immune systems, and its potential involvement in interodontoblast communications was recently demonstrated. In an effort to elaborate the ATP-mediated signaling pathway in odontoblasts, the current study performed single-cell reverse transcription polymerase chain reaction (RT-PCR) and immunofluorescent detection to investigate the expression of ATP receptors related to calcium signal in odontoblasts from incisal teeth of 8- to 10-wk-old rats, and demonstrated an in vitro response to ATP application via calcium imaging experiments. While whole tissue RT-PCR analysis detected P2Y₂, P2Y₄, and all 7 subtypes (P2X₁ to P2X₇) in tooth pulp, single-cell RT-PCR analysis of acutely isolated rat odontoblasts revealed P2Y₂, P2Y₄, P2X₂, P2X₄, P2X₆, and P2X₇ expression in only a subset (23% to 47%) of cells tested, with no evidence for P2X₁, P2X₃, and P2X₅ expression. An increase of intracellular Ca²⁺ concentration in response to 100μM ATP, which was repeated after pretreatment of thapsigargin or under the Ca²⁺-free condition, suggested function of both ionotropic and metabotropic ATP receptors in odontoblasts. The enhancement of ATP-induced calcium response by ivermectin and inhibition by 5-(3-bromophenyl)-1,3-dihydro-2H-benzofuro[3,2-e]-1,4-diazepin-2-one (5-BDBD) confirmed a functional P2X₄ subtype in odontoblasts. Positive calcium response to 2',3'-O-(benzoyl-4-benzoyl)-ATP (BzATP) and negative response to α,β-methylene ATP suggested P2X₂, P2X₄, and P2X₇ as functional subunits in rat odontoblasts. Single-cell RT-PCR analysis of the cells with confirmed calcium response and immunofluorescent detection further corroborated the expression of P2X₄ and P2X₇ in odontoblasts. Overall, this study demonstrated heterogeneous expression of calcium-related ATP receptor subtypes in subsets of individual odontoblasts, suggesting extracellular ATP as a potential signal mediator for odontoblastic functions.

Multi-threading the generation of Burrows-Wheeler Alignment

Along with recent progress in next-generation sequencing technology, it has become easier to process larger amounts of genome sequencing data at a lower cost. The most time-consuming step of next-generation sequencing data analysis involves the mapping of read data into a reference genome. Although the Burrows-Wheeler Alignment (BWA) tool is one of the most widely used open-source software tools for aligning read sequences, it still has a limitation in that it does not fully support a multi-thread mechanism during the alignment generation step. In this article, we propose a BWA-MT tool based on BWA that supports multi-thread mechanisms for processing alignment generation. To evaluate BWA-MT, we used an evaluation system equipped with 24 cores and 128 GB of memory. As workloads, we used the hg19 human genome reference sequence and sequences of various read sizes from the 1 to 40 M spots. In our evaluation, BWA-MT showed a maximum of 3.66-times better performance, and generated the same Sequence Alignment/Map result file as that of BWA. Although the ability to speed up the procedure might be dependent on computing resources, we confirmed that BWA-MT is a highly effective and fast alignment tool.

Aptamer-nanoparticle complexes as powerful diagnostic and therapeutic tools

Correct diagnosis and successful therapy are extremely important to enjoy a healthy life when suffering from a disease. To achieve these aims, various cutting-edge technologies have been designed and fabricated to diagnose and treat specific diseases. Among these technologies, aptamer-nanomaterial hybrids have received considerable attention from scientists and doctors because they have numerous advantages over other methods, such as good biocompatibility, low immunogenicity and controllable selectivity. In particular, aptamers, oligonucleic acids or peptides that bind to a specific target molecule, are regarded as outstanding biomolecules. In this review, several screening techniques for aptamers, also called systematic evolution of ligands by exponential enrichment (SELEX) methods, are introduced, and diagnostic and therapeutic aptamer applications are also presented. Furthermore, we describe diverse aptamer-nanomaterial conjugate designs and their applications for diagnosis and therapy.

Overexpression of angiotensin II type 1 receptor in breast cancer cells induces epithelial-mesenchymal transition and promotes tumor growth and angiogenesis

The angiotensin II type I receptor (AGTR1) has been implicated in diverse aspects of human disease, from the regulation of blood pressure and cardiovascular homeostasis to cancer progression. We sought to investigate the role of AGTR1 in cell proliferation, epithelial-mesenchymal transition (EMT), migration, invasion, angiogenesis and tumor growth in the breast cancer cell line MCF7. Stable overexpression of AGTR1 was associated with accelerated cell proliferation, concomitant with increased expression of survival factors including poly(ADP-ribose) polymerase (PARP) and X-linked inhibitor of apoptosis (XIAP), as well as extracellular signal-regulated kinase (ERK) activation. AGTR1-overexpressing MCF7 cells were more aggressive than their parent line, with significantly increased activity in migration and invasion assays. These observations were associated with changes in EMT markers, including reduced E-cadherin expression and increased p-Smad3, Smad4 and Snail levels. Treatment with the AGTR1 antagonist losartan attenuated these effects. AGTR1 overexpression also accelerated tumor growth and increased Ki-67 expression in a xenograft model. This was associated with increased tumor angiogenesis, as evidenced by a significant increase in microvessels in the intratumoral and peritumoral areas, and enhanced tumor invasion, with the latter response associated with increased EMT marker expression and matrix metallopeptidase 9 (MMP-9) upregulation. In vivo administration of losartan significantly reduced both tumor growth and angiogenesis. Our findings suggest that AGTR1 plays a significant role in tumor aggressiveness, and its inhibition may have therapeutic implications.

A highly sensitive and selective impedimetric aptasensor for interleukin-17 receptor A

Interleukin-17 receptor A (IL-17RA) has been recognized as a valuable biomarker for diverse diseases, including autoimmune diseases. In this work, an electrochemical biosensor with great sensitivity and selectivity toward IL-17RA was fabricated using an IL-17RA aptamer (Kd=14.00nM) for the first time. The aptasensor was manufactured using electrodeposition of gold nanoparticles, and then quantitative detection of IL-17RA was performed based on impedimetry. The developed sensor exhibited a superior analytical performance for IL-17RA with a wide dynamic range of 10-10,000pg/mL in buffer and a detection limit of 2.13pg/mL, which is lower than that of commercially available ELISA kits. In addition, we validated the high specificity of the designed aptasensor to only IL-17RA, which showed good sensitivity even in human serum solution. Furthermore, the detection of the differentiated HL-60 cells expressing IL-17RA was successfully performed. Clinical applicability of the sensor was also demonstrated utilizing neutrophils separated from asthma patients. It is expected that the fabricated aptasensor will become an excellent diagnostic platform for IL-17RA-mediated diseases.

Electrochemical aptasensor of cardiac troponin I for the early diagnosis of acute myocardial infarction

Cardiac troponin I (cTnI) is well-known as a promising biomarker for the early diagnosis of acute myocardial infarction (AMI). In this work, single-stranded DNA aptamers against cTnI were identified by the Systematic Evolution of Ligands by Exponential enrichment (SELEX) method. The aptamer candidates exhibited a high selectivity and sensitivity toward both cTnI and the cardiac Troponin complex. The binding affinities of each aptamer were evaluated based on their dissociation constants (Kd) by surface plasma resonance. The Tro4 aptamer that had the highest binding capacity to cTnI showed a very low Kd value (270 pM) compared with that of a cTnI antibody (20.8 nM). Furthermore, we designed a new electrochemical aptasensor based on square wave voltammetry using ferrocene-modified silica nanoparticles. The developed aptasensor demonstrated an excellent analytical performance for cTnI with a wide linear range of 1-10 000 pM in a buffer and a detection limit of 1.0 pM (24 pg/mL; S/N = 3), which was noticeably lower than the cutoff values (70-400 pg/mL). The specificity of the aptamers was also examined using nontarget proteins, demonstrating that the proposed sensor responded to only cTnI. In addition, cTnI was successfully detected in a human serum albumin solution. On the basis of the calibration curve that was constructed, the concentrations of cTnI in a solution supplemented with human serum were effectively measured. The calculated values correlated well with the actual concentrations of cTnI. It is anticipated that the highly sensitive and selective aptasensor for cTnI could be readily applicable for the accurate diagnosis of AMI.

Dual aptamer-functionalized silica nanoparticles for the highly sensitive detection of breast cancer

In this study, we synthesized dual aptamer-modified silica nanoparticles that simultaneously target two types of breast cancer cells: the mucin 1 (MUC1)(+) and human epidermal growth factor receptor 2 (HER2)(+) cell lines. Dual aptamer system enables a broad diagnosis for breast cancer in comparison with the single aptamer system. The dye-doped silica nanoparticles offer great stability with respect to photobleaching and enable the accurate quantification of breast cancer cells. The morphological and spectroscopic characteristics of the designed Dual-SiNPs were demonstrated via diverse methods such as DLS, zeta potential measurements, UV-vis spectroscopy, and fluorescence spectroscopy. Negatively charged Dual-SiNPs with a homogeneous size distribution showed robust and strong fluorescence. In addition, Dual-SiNPs did not affect cell viability, implying that this probe might be readily available for use in an in vivo system. Through ratio optimization of the MUC1 and HER2 aptamers, the binding capacities of the Dual-SiNPs to both cell lines were maximized. Based on Dual-SiNPs, a highly sensitive quantification of breast cancer cells was performed, resulting in a detection limit of 1 cell/100 μL, which is significantly lower compared with those reported in other studies. Moreover, the developed detection platform displayed high selectivity for only the MUC1(+) and HER2(+) cell lines. It is expected that this valuable diagnostic probe will be a noteworthy platform for the diagnosis and prognosis of breast cancer.

Structural insights into Escherichia coli polymyxin B resistance protein D with X-ray crystallography and small-angle X-ray scattering

BACKGROUND

Polymyxin B resistance protein D (PmrD) plays a key role in the polymyxin B-resistance pathway, as it is the signaling protein that can act as a specific connecter between PmrA/PmrB and PhoP/PhoQ. We conducted structural analysis to characterize Escherichia coli (E. coli) PmrD, which exhibits different features compared with PmrD in other bacteria.

RESULTS

The X-ray crystal structure of E. coli PmrD was determined at a 2.00 Å resolution, revealing novel information such as the unambiguous secondary structures of the protein and the presence of a disulfide bond. Furthermore, various assays such as native gel electrophoresis, surface plasmon resonance (SPR), size-exclusion chromatography, dynamic light scattering (DLS), and small-angle X-ray scattering (SAXS) measurements, were performed to elucidate the structural and functional role of the internal disulfide bond in E. coli PmrD.

CONCLUSIONS

The structural characteristics of E. coli PmrD were clearly identified via diverse techniques. The findings help explain the different protective mechanism of E. coli compared to other Gram-negative bacteria.

Ultra-effective photothermal therapy for prostate cancer cells using dual aptamer-modified gold nanostars

Although various studies related to nanoparticles-based photothermal therapy have been actively performed, an epoch-making photothermolysis therapy exhibiting both high selectivity and efficiency has yet not been discovered. For the first time, we have developed novel valuable therapeutic complexes, namely, dual aptamer-modified gold nanostars, for the targeting of prostate cancers, including PSMA(+) and PSMA(-) cells. The synthesized probes were characterized through several techniques, including UV-VIS spectral analysis, DLS analysis, zeta potential measurements, and TEM imaging, and were subsequently subjected to cytotoxicity tests, cell uptake confirmation, and in vitro photothermal therapy. The homogeneously well-fabricated nanostars presented high selectivity to prostate cancer cells and extremely high efficiency for therapy using an 808 nm laser under an irradiance of 0.3 W cm^-2, which is lower than the permitted value for skin exposure (0.329 W cm^-2). It is anticipated that this novel photothermal agent will become the general platform for targeted therapy.

Characterization of multi-functional properties and conformational analysis of MutS2 from Thermotoga maritima MSB8

The MutS2 homologues have received attention because of their unusual activities that differ from those of MutS. In this work, we report on the functional characteristics and conformational diversities of Thermotoga maritima MutS2 (TmMutS2). Various biochemical features of the protein were demonstrated via diverse techniques such as scanning probe microscopy (SPM), ATPase assays, analytical ultracentrifugation, DNA binding assays, size chromatography, and limited proteolytic analysis. Dimeric TmMutS2 showed the temperature-dependent ATPase activity. The non-specific nicking endonuclease activities of TmMutS2 were inactivated in the presence of nonhydrolytic ATP (ADPnP) and enhanced by the addition of TmMutL. In addition, TmMutS2 suppressed the TmRecA-mediated DNA strand exchange reaction in a TmMutL-dependent manner. We also demonstrated that small-angle X-ray scattering (SAXS) analysis of dimeric TmMutS2 exhibited nucleotide- and DNA-dependent conformational transitions. Particularly, TmMutS2-ADPnP showed the most compressed form rather than apo-TmMutS2 and the TmMutS2-ADP complex, in accordance with the results of biochemical assays. In the case of the DNA-binding complexes, the stretched conformation appeared in the TmMutS2-four-way junction (FWJ)-DNA complex. Convergences of biochemical- and SAXS analysis provided abundant information for TmMutS2 and clarified ambiguous experimental results.

A highly sensitive aptasensor towards Plasmodium lactate dehydrogenase for the diagnosis of malaria

Finding a highly sensitive diagnostic technique for malaria has challenged scientists for the last century. In the present study, we identified versatile single-strand DNA aptamers for Plasmodium lactate dehydrogenase (pLDH), a biomarker for malaria, via the Systematic Evolution of Ligands by EXponential enrichment (SELEX). The pLDH aptamers selectively bound to the target proteins with high sensitivity (K(d)=16.8-49.6 nM). The selected aptamers were characterized using an electrophoretic mobility shift assay, a quartz crystal microbalance, a fluorescence assay, and circular dichroism spectroscopy. We also designed a simple aptasensor using electrochemical impedance spectroscopy; both Plasmodium vivax LDH and Plasmodium falciparum LDH were selectively detected with a detection limit of 1 pM. Furthermore, the pLDH aptasensor clearly distinguished between malaria-positive blood samples of two major species (P. vivax and P. falciparum) and a negative control, indicating that it may be a useful tool for the diagnosis, monitoring, and surveillance of malaria.

A turn-on two-photon fluorescent probe for ATP and ADP

An acedan derivative containing Zn(II)-DPA has been developed as a two-photon probe for nucleoside phosphates, which shows enhanced fluorescence toward ATP and ADP at physiological pH 7.4 among other competing anions including AMP; the probe is permeable to cell membranes and thus can be directly used for two-photon imaging of ATP and ADP in live cells.

Gold nanoparticle-based colorimetric detection of kanamycin using a DNA aptamer

A selective kanamycin-binding single-strand DNA (ssDNA) aptamer (TGGGGGTTGAGGCTAAGCCGA) was discovered through in vitro selection using affinity chromatography with kanamycin-immobilized sepharose beads. The selected aptamer has a high affinity for kanamycin and also for kanamycin derivatives such as kanamycin B and tobramycin. The dissociation constants (K(d) [kanamycin]=78.8 nM, K(d) [kanamycin B]=84.5 nM, and K(d) [tobramycin]=103 nM) of the new aptamer were determined by fluorescence intensity analysis using 5'-fluorescein amidite (FAM) modification. Using this aptamer, kanamycin was detected down to 25 nM by the gold nanoparticle-based colorimetric method. Because the designed colorimetric method is simple, easy, and visible to the naked eye, it has advantages that make it useful for the detection of kanamycin. Furthermore, the selected new aptamer has many potential applications as a bioprobe for the detection of kanamycin, kanamycin B, and tobramycin in pharmaceutical preparations and food products.

Inorganic phosphate induces mammalian growth plate chondrocyte apoptosis in a mitochondrial pathway involving nitric oxide and JNK MAP kinase

Chondrocytes in the hypertrophic zone of the growth plate undergo apoptosis during endochondral bone development via mechanisms that involve inorganic phosphate (Pi) and nitric oxide (NO). Recent evidence suggests that Pi-dependent NO production plays a role in apoptosis of cells in the resting zone as well. This study examined the mechanism by which Pi induces NO production and the signaling pathways by which NO mediates its effects on apoptosis in these cells. Pi decreased the number of viable cells based on MTT activity; the number of TUNEL-positive cells and the level of DNA fragmentation were increased, indicating an increase in apoptosis. Blocking NO production using the NO synthase (NOS) inhibitor L: -NAME or cells from eNOS(-/-) mice blocked Pi-induced chondrocyte apoptosis, indicating that NO production is necessary. NO donors NOC-18 and SNOG both induced chondrocyte apoptosis. SNOG also upregulated p53 expression, the Bax/Bcl-2 expression ratio, and cytochrome c release from mitochondria, as well as caspase-3 activity, indicating that NO induces apoptosis via a mitochondrial pathway. Inhibition of JNK, but not of p38 or ERK1/2, MAP kinase was able to block NO-induced apoptosis, indicating that JNK is necessary in this pathway. Pi elevates NO production via eNOS in resting zone chondrocytes, which leads to a mitochondrial apoptosis pathway dependent on JNK.

Molecular characterization of the human ABO blood group orthologus system in pigs

The selection and use of animals with blood group 0 in the process of transplanting pig organs or tissues into humans can positively contribute to the control of acute immune rejection due to differences in blood groups. Exon-specific PCRs for the porcine blood group A transferase gene against genomic DNA from either blood group A or 0 animals resulted in the amplification failure of the A0 blood group gene exon 8 from blood group 0 animals. To characterize the genetic abnormality in the genome of blood group 0 animals, we screened bacterial artificial chromosome (BAC) clones from a Korean native pig BAC library which had the blood group 0 allele, and carried out shotgun sequencing. The analysis showed that the 0 allele has a large deletion between exon 7 of the A0 blood group gene and the neighbouring SURF6. We also showed that the ABO blood group antigens in humans and the A0 blood group antigens in pigs are coded by mutations within the orthologous glycosyltransferase gene. In addition, we developed a multiplex genotyping method for the porcine A0 blood group gene.

Assessment of referral patterns for CT KUB in a tertiary setting

The purpose of this study was to assess the referral patterns and the use of unenhanced renal tract CT (CT KUB) for investigating patients presenting with clinically suspected renal colic. We retrospectively reviewed 500 consecutive CT KUB studies requested for suspected renal colic carried out at a single institution between December 2006 and July 2007. Follow-up radiology reports and discharge summaries on the hospital clinical Intranet were also reviewed. Studies were analysed for characteristics including patient demographics, referring clinical team, time of referral, final diagnosis and requirement for further imaging. The majority of requests were from Emergency (ED) or Urology Departments (49%, 245 out of 500, and 37%, 186 out of 500, respectively). The positive rate for urolithiasis was 67% (337 out of 500), the negative rate was 25% (123 out of 500), and 8% (40 out of 500) of patients had alternative significant findings. Female patients were more likely to have a negative study than male patients (35 versus 20%, P < 0.0001) and more likely to have alternative significant pathology (12 versus 6%, P < 0.0001). Patients referred by specialities other than Urology and ED were more likely to be female and have a negative or alternative finding (P < 0.0001). CT KUB is a widely used first method of investigation for patients with suspected renal colic with a high positive predictive value allowing rapid diagnosis and intervention. However, given the high rate of negative or alternative findings on CT KUB in young women, especially those referred by specialities other than ED or Urology, ultrasound should be considered as an alternative imaging method to minimise unnecessary radiation exposure.

The in vitro effects of dehydroepiandrosterone on human osteoarthritic chondrocytes

OBJECTIVE

To investigate the in vitro effects of dehydroepiandrosterone (DHEA) on human osteoarthritic chondrocytes.

DESIGN

Chondrocytes isolated from human osteoarthritic knee cartilage were three-dimensionally cultured in alginate beads, except for cell proliferation experiment. Cells were treated with DHEA in the presence or absence of IL-1beta. The effects on chondrocytes were analyzed using a 3-(4,5-dimethylthiazol-2yl)-5-(3-carboxymethoxy-phenyl)-2-(4-sulfophenyl)-2H-tetrazolium inner salt (MTS) assay (for chondrocyte proliferation), a dimethylmethylene blue (DMB) assay (for glycosaminoglycan (GAG) synthesis), and an indole assay (for DNA amount). Gene expressions of type I and II collagen, metalloproteinase-1 and -3 (MMP-1 and -3), and tissue inhibitor of metalloproteinase-1 (TIMP-1) as well as the IL-1beta-induced gene expressions of MMP-1 and -3 were analyzed by reverse transcription-polymerase chain reaction (RT-PCR). The protein synthesis of MMP-1 and -3 and TIMP-1 was determined by Western blotting.

RESULTS

The treatment of chondrocytes with DHEA did not affect chondrocyte proliferation or GAG synthesis up to 100 micro M of concentration. The gene expression of type II collagen increased in a dose-dependent manner, while that of type I decreased. DHEA suppressed the expression of MMP-1 significantly at concentrations exceeding 50 micro M. The gene expression of MMP-3 was also suppressed, but this was without statistical significance. The expression of TIMP-1 was significantly increased by DHEA at concentrations exceeding 10 micro M. The effects of DHEA on the gene expressions of MMP-1 and -3 were more prominent in the presence of IL-1beta, in which DHEA suppressed not only MMP-1, but also MMP-3 at the lower concentrations, 10 and 50 micro M, respectively. Western blotting results were in agreement with RT-PCR, which indicates that DHEA acts at the gene transcription level.

CONCLUSIONS

Our study demonstrates that DHEA has no toxic effect on chondrocytes up to 100 micro M of concentration and has an ability to modulate the imbalance between MMPs and TIMP-1 during OA at the transcription level, which suggest that it has a protective role against articular cartilage loss.

Endothelial NOS-dependent activation of c-Jun NH(2)- terminal kinase by oxidized low-density lipoprotein

Oxidized low-density lipoprotein (oxLDL) is known to activate a number of signal transduction pathways in endothelial cells. Among these are the c-Jun NH(2)-terminal kinase (JNK), also known as stress-activated protein kinase, and extracellular signal-regulated kinase (ERK). These mitogen-activated protein kinases (MAP kinase) determine cell survival in response to environmental stress. Interestingly, JNK signaling involves redox-sensitive mechanisms and is activated by reactive oxygen and nitrogen species derived from both NADPH oxidases, nitric oxide synthases (NOS), peroxides, and oxidized low-density lipoprotein (oxLDL). The role of endothelial NOS (eNOS) in the activation of JNK in response to oxLDL has not been examined. Herein, we show that on exposure of endothelial cells to oxLDL, both ERK and JNK are activated through independent signal transduction pathways. A key role of eNOS activation through a phosphatidylinositol-3-kinase-dependent mechanism leading to phosphorylation of eNOS is demonstrated for oxLDL-dependent activation of JNK. Moreover, we show that activation of ERK by oxLDL is critical in protection against the cytotoxicity of oxLDL.