Proteomic analysis of peritoneal fluid identified COMP and TGFBI as new candidate biomarkers for endometriosis

Endometriosis is a common non-malignant gynecological disease that significantly compromises fertility and quality of life of the majority of patients. The gold standard for diagnosis is visual inspection of the pelvic organs by surgical laparoscopy and there are no biomarkers that would allow non-invasive diagnosis. The pathogenesis of endometriosis is not completely understood, thus analysis of peritoneal fluid might contribute in this respect. Our prospective case–control study included 58 patients undergoing laparoscopy due to infertility, 32 patients with peritoneal endometriosis (cases) and 26 patients with unexplained primary infertility (controls). Discovery proteomics using antibody microarrays that covered 1360 proteins identified 16 proteins with different levels in cases versus the control patients. The validation using an ELISA approach confirmed significant differences in the levels of cartilage oligomeric matrix protein (COMP) and transforming growth factor-β-induced protein ig-h3 (TGFBI) and nonsignificant differences in angiotensinogen (AGT). A classification model based on a linear support vector machine revealed AUC of > 0.83, sensitivity of 0.81 and specificity of 1.00. Differentially expressed proteins represent candidates for diagnostic and prognostic biomarkers or drug targets. Our findings have brought new knowledge that will be helpful in the understanding of the pathophysiology of endometriosis and warrant further studies in blood samples.

Fluorescence Signal Enhancement in Antibody Microarrays Using Lightguiding Nanowires

Fluorescence-based detection assays play an essential role in the life sciences and medicine. To offer better detection sensitivity and lower limits of detection (LOD), there is a growing need for novel platforms with an improved readout capacity. In this context, substrates containing semiconductor nanowires may offer significant advantages, due to their proven light-emission enhancing, waveguiding properties, and increased surface area. To demonstrate and evaluate the potential of such nanowires in the context of diagnostic assays, we have in this work adopted a well-established single-chain fragment antibody-based assay, based on a protocol previously designed for biomarker detection using planar microarrays, to freestanding, SiO2-coated gallium phosphide nanowires. The assay was used for the detection of protein biomarkers in highly complex human serum at high dilution. The signal quality was quantified and compared with results obtained on conventional flat silicon and plastic substrates used in the established microarray applications. Our results show that using the nanowire-sensor platform in combination with conventional readout methods, improves the signal intensity, contrast, and signal-to-noise by more than one order of magnitude compared to flat surfaces. The results confirm the potential of lightguiding nanowires for signal enhancement and their capacity to improve the LOD of standard diagnostic assays.

A Protein Chip Study on the Heart Failure With Recovered Ejection Fraction

Background: Characteristics of heart failure with recovered ejection fraction (HFrecEF) have not yet been fully understood. The objective of this study is to identify potential biomarkers for the left ventricular ejection fraction(LVEF) recovery. Methods: Antibody microarrays were used to detect proteins in serum of healthy volunteers, patients with heart failure with reduced ejection fraction(HFrEF), and patients with HFrecEF, looking for specific proteins of HFrecEF patients.Results:1000 proteins were detected in the sera of healthy volunteers, HFrEF patients and HFrecEF patients using antibody microarrays (three in each group). There were dozens of different proteins between each group. Based on the signal strength, fold changes, clinical significance and Venn diagram analysis, 11 proteins were selected to be detected in the sera of 10 healthy volunteers ,47 HFrEF patients and 22 HFrecEF patients using antibody microarrays. Serum concentrations of cysteine dioxygenase type 1 (CDO1) and growth/differentiation factor 8 (GDF-8) were significantly downregulated in HFrecEF patients compared with HFrEF patients. ROC curve analysis showed that the area under the CDO1 curve was 0.662(95%CI 0.517-0.808,P=0.031).The sensitivity of CDO1 was 77%, the specificity was 54%, and diagnostic cut‑off points was 10198.5.The GDF-8 has no diagnostic value. Kaplan–Meier survival curves showed that the prognosis is better in HFrecEF patients than HFrEF patients about all cause death(P=0.011) and cardiovascular death(P=0.004).But we did not find that patients with low baseline CDO1 levels (<10198.5) had better outcomes than those with high CDO1 levels (≥10198.5).Conclusions: This pilot study indicates that CDO1 is a potential biomarker of LVEF recovery, which needs to be confirmed by further studies.

Results from the Population-Based Gutenberg Health Study Revealing Four Altered Autoantibodies in Retinal Vein Occlusion Patients

Purpose. Retinal vein occlusion (RVO) is the second most common retinal vascular disease and a major cause of visual impairment. In this study, we aimed to observe whether RVO cases have different antibody profiles as a new potential risk factor and whether a conversion of retinal vein occlusion (RVO) to neovascular glaucoma (NVG), one of the major complications, is occurring within a 5-year timeframe. Methods. We performed a nested case-control study (1 : 4) within the Gutenberg Health Study (GHS), a population-based, prospective cohort study in the Rhine-Main Region of Germany including 15,010 participants. RVO subjects (n = 59) were identified by grading of fundus photographs. Optic nerves of RVO subjects and age- and sex-matched controls (n = 229) at baseline and their follow-up examination after 5 years were analyzed for glaucomatous alterations. Of all RVO subjects and controls, serum autoantibody profiles were measured using in-house manufactured antigen-antibody microarrays. Results. Of the 59 RVO patients, 3 patients (5%) showed glaucomatous optic disc alterations at baseline, whereas no new glaucoma case was detected at 5-year follow-up. Four of the autoantibodies measured (against dermcidin, neurotrophin-3, superoxide dismutase 1, and signal recognition particle 14 kDa protein) were significantly increased in the serum of RVO patients p<0.001. Multivariable conditional logistic regression analysis showed that 3 of these 4 antibodies were independent of cardiovascular risk factors. Conclusions. We found several autoantibodies associated with RVO, targeting proteins and structures possibly involved in RVO pathogenesis.

Advantageous Antibody Microarray Fabrication Through DNA-Directed Immobilization: A Step Toward Use of Extracellular Vesicles in Diagnostics

An optimized general protocol for DNA-protein ligation is provided and the conjugates are used to convert DNA arrays into antibody microarrays. Arrays obtained through DDI were used to capture and characterize extracellular vesicles (EVs), an emerging class of biomarkers. The proposed platform was tested against commercially available antibody microarrays, showing good performance combined with ease of fabrication.

Advantageous Antibody Microarray Fabrication Through DNA-Directed Immobilization: A Step Toward Use of Extracellular Vesicles in Diagnostics

An optimized general protocol for DNA-protein ligation is provided and the conjugates are used to convert DNA arrays into antibody microarrays. Arrays obtained through DDI were used to capture and characterize extracellular vesicles (EVs), an emerging class of biomarkers. The proposed platform was tested against commercially available antibody microarrays, showing good performance combined with ease of fabrication.

Platelets release proinflammatory microparticles in anti-neutrophil cytoplasmic antibody-associated vasculitis

Objective The biological functions of the platelets contributing to ANCA-associated vasculitis (AAV) are largely unclear. The current study aimed to investigate the potential role of platelet-derived microparticles (PMPs) in AAV. Methods In the current study, microparticles in AAV patients were analysed by flow cytometry, and PMPs were probed for relative levels of 640 bioactive proteins secreted from patients’ platelets using antibody microarrays. These data were then correlated with clinical and pathological parameters. Results PMPs were significantly increased in 69 AAV patients, predominantly MPO-ANCA positive patients in active stage compared with in remission [4406.8/μl (2135.4, 5485.0) vs 549.7/μl (350, 708.5), P < 0.0001], and 43% of microparticles in active AAV were PMPs. Compared with 15 patients in remission, highly expressed proinflammatory molecules in the microparticles from platelets in 15 AAV patients in active stage revealed that potential functions of PMPs were promotion of the effect of chemotaxis, adhesion, growth and apoptosis (all the patients for array analysis were MPO-ANCA positive). The level of PMPs had a significant association with disease activity, inflammation, and renal damage. Conclusion PMPs may serve as inflammatory propagators through their wide production of proinflammatory cytokines in AAV, potentially providing a novel therapeutic target.