LifeSensors (United States)

IntroductionPatterns of treatment response can inform clinical decision-making. This study assessed the course and impact of achieving minimal clinically important improvement (MCII) in clinical measures and patient-reported outcomes (PROs) with guselkumab in patients with active psoriatic arthritis (PsA).MethodsPost hoc analyses evaluated 1120 patients with PsA receiving guselkumab every 4 or 8 weeks (Q4W/Q8W) or placebo from DISCOVER-1 (31% tumor necrosis factor inhibitor-experienced) and DISCOVER-2 (biologic-naïve). Achievement of MCII in clinical Disease Activity Index for PsA (cDAPSA), patient global assessment (PtGA) of arthritis, PtGA of psoriasis, patient-reported pain, Functional Assessment of Chronic Illness Therapy-Fatigue, Health Assessment Questionnaire-Disability Index, 36-item Short-Form Health Survey Physical Component Summary score, PtGA Arthritis + Psoriasis, and PsA Disease Activity Score (PASDAS) was compared between the guselkumab and placebo groups using Cox regression. Logistic regression adjusting for baseline factors evaluated associations between early (W4/W8) MCII achievement and stringent response (≥%50/%70 improvement in American College of Rheumatology response criteria, cDAPSA low disease activity [LDA], PASDAS LDA, and minimal disease activity) at W24/W52 among guselkumab-randomized patients.ResultsAmong patients with highly active PsA (baseline cDAPSA = 44.1–45.0, PASDAS = 6.4–6.5), times to MCII were significantly faster for guselkumab vs. placebo (hazard ratios 1.3–2.5; P < 0.05). Across measures, at first timepoint assessed, MCII rates were significantly higher with guselkumab (Q4W/Q8W 28–68%/29–65%) vs. placebo (19–47%; both P < 0.05). Early (W4/W8) MCII with guselkumab associated with higher odds of achieving stringent responses at W24/W52 (odds ratios 1.4–17.2/1.4–5.4).ConclusionsIn a mixed PsA population, significant proportions of patients treated with guselkumab achieved early (W4/W8) MCII across clinical and PRO measures, which associated with a higher likelihood of attaining clinically relevant improvements and low levels of disease activity at W24/W52.Trial registrationDISCOVER-1 (NCT03162796).DISCOVER-2 (NCT03158285).Supplementary InformationThe online version contains supplementary material available at 10.1007/s40744-024-00702-0.

Detecting cancer at an early stage of disease progression promises better treatment outcomes and longer lifespans for cancer survivors. Research has been directed towards the development of accessible and highly sensitive cancer diagnostic tools, many of which rely on protein biomarkers and biomarker panels which are overexpressed in body fluids and associated with different types of cancer. Protein biomarker detection for point-of-care (POC) use requires the development of sensitive, noninvasive liquid biopsy cancer diagnostics that overcome the limitations and low sensitivities associated with current dependence upon imaging and invasive biopsies. Among many endeavors to produce user-friendly, semi-automated, and sensitive protein biomarker sensors, 3D printing is rapidly becoming an important contemporary tool for achieving these goals. Supported by the widely available selection of affordable desktop 3D printers and diverse printing options, 3D printing is becoming a standard tool for developing low-cost immunosensors that can also be used to make final commercial products. In the last few years, 3D printing platforms have been used to produce complex sensor devices with high resolution, tailored towards researchers’ and clinicians’ needs and limited only by their imagination. Unlike traditional subtractive manufacturing, 3D printing, also known as additive manufacturing, has drastically reduced the time of sensor and sensor array development while offering excellent sensitivity at a fraction of the cost of conventional technologies such as photolithography. In this review, we offer a comprehensive description of 3D printing techniques commonly used to develop immunosensors, arrays, and microfluidic arrays. In addition, recent applications utilizing 3D printing in immunosensors integrated with different signal transduction strategies are described. These applications include electrochemical, chemiluminescent (CL), and electrochemiluminescent (ECL) 3D-printed immunosensors. Finally, we discuss current challenges and limitations associated with available 3D printing technology and future directions of this field.

The establishment of polyubiquitin conjugates with distinct linkages play important roles in the DNA damage response. Much remains unknown about the regulation of linkage-specific ubiquitin signaling at sites of DNA damage. Here we reveal that Cezanne (also known as Otud7B) deubiquitinating enzyme promotes the recruitment of Rap80/BRCA1-A complex by binding to Lys63-polyubiquitin and targeting Lys11-polyubiquitin. Using a ubiquitin binding domain protein array screen, we identify that the UBA domains of Cezanne and Cezanne2 (also known as Otud7A) selectively bind to Lys63-linked polyubiquitin. Increased Lys11-linkage ubiquitination due to lack of Cezanne DUB activity compromises the recruitment of Rap80/BRCA1-A. Cezanne2 interacts with Cezanne, facilitating Cezanne in the recruitment of Rap80/BRCA1-A, Rad18, and 53BP1, in cellular resistance to ionizing radiation and DNA repair. Our work presents a model that Cezanne serves as a "reader" of the Lys63-linkage polyubiquitin at DNA damage sites and an "eraser" of the Lys11-linkage ubiquitination, indicating a crosstalk between linkage-specific ubiquitination at DNA damage sites.

Abstract Cells regulate their internal functions by the ubiquitylation of many key proteins, especially onco-proteins and tumor suppressors. As a result, ubiquitin proteasome system (UPS) substrates and the relevant UPS enzymes have been identified as attractive anti-cancer targets. However, traditional methods for monitoring ubiquitylation patterns, including by immunoprecipitation coupled with immunoblot analysis (IP/IB) or by mass spectrometry methods, are either insensitive, low throughput, or highly intensive. Here, we describe three Tandem Ubiquitin Binding Entity (TUBE)-based assays, UbiTest, HT-UbiTest, and UbiQuant S, which provide a platform to efficiently detect ubiquitylation of anti-cancer targets. UbiTest is an immunoblot-based assay, which can be used to easily identify ubiquitlyated proteins. Compared to traditional ubiquitin IP/IB, this assay avoids epitope masking of antibodies caused by ubiquitin modification. HT-UbiTest extends this concept using a TUBE pulldown followed by two-antibody detection in a 96-well plate, and allows high-throughput absolute quantification of a target of interest. UbiQuant S is a high-throughput assay to quantify ubiquitylation status in cells or tissue. Ubiquitylated proteins are identified by energy transfer between AlphaLISA bead-labeled TUBE and antibody against the endogenous protein of interest in a homogenous plate-based assay. Furthermore, we have extended these technologies to identify K63- and K48-linked poly-ubiquitylated proteins using poly-ubiquitin linkage-selective TUBEs. Several prominent therapeutic targets in oncology and immuno-oncology have been used to verify these assays, including Cbl-b and its substrates, p53, and USP7. The efficiency and sensitivity of these assays have wide applications in drug discovery targeting ubiquitylation-dependent signaling pathways. Examples using DUB and ubiquitin ligase inhibitors illustrate the power of this system. These novel assays are versatile tools for understanding the role of ubiquitylation in cancer treatment, and provide platforms to monitor disease biomarkers in response to drug action. Citation Format: Peter K. Foote, Xiaolong Lu, Rajesh Singh. Establishing ubiquitylation patterns in cells: Efficient monitoring of oncogenic ubiquitylation activity [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2018; 2018 Apr 14-18; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2018;78(13 Suppl):Abstract nr 3539.

Abstract Plasmid-based functional proteomics is an important technology for rapidly obtaining large quantities of protein and determining protein function across an entire genome. It centers on production of full-length cDNA libraries as a source of plasmid-based clones to express the desired proteins in active form to determine their function. Because plasmid libraries are composed of several thousand unique genes, automation of the process is essential. High-throughput platforms that can rapidly clone and express heterologous gene open reading frames (ORFs) in bacteria and yeast and can screen large numbers of expressed proteins for optimized function are important for improving microbial strains for biofuel production. Combined with rapid gene assembly and mutagenesis strategies, gene ORFs can be synthesized, cloned, transformed into yeast strains, and screened to identify those that will give increased ethanol production, allow coproduction of biodiesel, enable use of biomass as a feedstock, and express valuable coproducts. The approach for the past 10 years has been to overexpress proteins that enable microbes to perform functions allowing improved production of biofuels. The next step will be to generate stable strains containing the genes that overexpress these proteins. This will need to be coupled with technologies such as Western blot analysis, high-throughput microscopy, mass spectrometry, gas chromatography, Raman spectroscopy, and microarray analysis to identify critical pathways and metabolites. These techniques adapted to an automated systems biology platform will allow tailoring of microbial strains to use renewable feedstocks for production of biofuels, bioderived chemicals, fertilizers, and other coproducts for profitable and sustainable biorefineries.KeywordsEthanol ProductionRobotic PlatformXylose IsomeraseFatty Acid Ethyl EsterGene ORFsThese keywords were added by machine and not by the authors. This process is experimental and the keywords may be updated as the learning algorithm improves.

We recently demonstrated that plasma membrane KCa3.1 is rapidly endocytosed and targeted for lysosomal degradation via a Rab7- and ESCRT-dependent pathway. Herein, we assess the role of ubiquitylation in this process. Using a biotin ligase acceptor peptide (BLAP)-tagged KCa3.1, in combination with tandem ubiquitin binding entities (TUBEs), we demonstrate that KCa3.1 is polyubiquitylated following endocytosis. Hypertonic sucrose inhibited KCa3.1 endocytosis and resulted in a significant decrease in channel ubiquitylation. Inhibition of the ubiquitin-activating enzyme (E1) with UBEI-41 resulted in reduced KCa3.1 ubiquitylation and internalization. The general deubiquitylase (DUB) inhibitor, PR-619 attenuated KCa3.1 degradation, indicative of deubiquitylation being required for lysosomal delivery. Using the DUB Chip, a protein microarray containing 35 DUBs, we demonstrate a time-dependent association between KCa3.1 and USP8 following endocytosis, which was confirmed by coimmunoprecipitation. Further, overexpression of wild-type USP8 accelerates channel deubiquitylation, while either a catalytically inactive mutant USP8 or siRNA-mediated knockdown of USP8 enhanced accumulation of ubiquitylated KCa3.1, thereby inhibiting channel degradation. In summary, by combining BLAP-tagged KCa3.1 with TUBEs and DUB Chip methodologies, we demonstrate that polyubiquitylation mediates the targeting of membrane KCa3.1 to the lysosomes and also that USP8 regulates the rate of KCa3.1 degradation by deubiquitylating KCa3.1 prior to lysosomal delivery.

SUMOylation, the covalent attachment of SUMO (small ubiquitin-like modifier), is a eukaryotic post-translational event that has been demonstrated to play a critical role in several biological processes. When used as an N-terminal tag or fusion partner, SUMO has been shown to enhance functional protein production significantly by improving folding, solubility, and stability. We have engineered several SUMOs and, through their fusion, developed a system for enhancing the expression and secretion of complex proteins. To demonstrate the fidelity of this fusion technology, secreted phospholipase A(2) proteins (sPLA(2)) were produced using HEK-293T and CHO-K1 cells. Five mouse sPLA(2) homologs were expressed and secreted in mammalian cell cultures using SUMO or SUMO-derived, N-terminal fusion partners. Mean and median increases of 43- and 18-fold, respectively, were obtained using novel SUMO mutants that are resistant to digestion by endogenous deSUMOylases.

SUMO (small ubiquitin-related modifier) modulates protein structure and function by covalently binding to the lysine side chains of the target proteins. Yeast cells contain two SUMO proteases, Ulp1 and Ulp2, that cleave sumoylated proteins in the cell. Ulp1 (SUMO protease 1) processes the SUMO precursor to its mature form and also de-conjugates SUMO from side chain lysines of target proteins. Here we demonstrate that attachment of SUMO to the N-terminus of under-expressed proteins dramatically enhances their expression in E. coli. SUMO protease 1 was able to cleave a variety of SUMO fusions robustly and with impeccable specificity. Purified recombinant SUMO-GFPs were efficiently cleaved when any amino acid, except proline, was in the+1 position of the cleavage site. The enzyme was active over a broad range of buffer and temperature conditions. Purification of certain recombinant proteins is accomplished by production of Ub-fusions from which Ub can be subsequently removed by de-ubiquitinating enzymes (DUBs). However, DUBs are unstable enzymes that are difficult to produce and inexpensive DUBs are not available commercially. Our findings demonstrate that SUMO protease 1/SUMO-fusion system may be preferable to DUB/Ub-fusion. Enhanced expression and solubility of proteins fused to SUMO combined with broad specificity and highly efficient cleavage properties of the SUMO protease 1 indicates that SUMO-fusion technology will become a useful tool in purification of proteins and peptides.