Capillary Electrophoresis Immunoassay Research Articles

Comparison between capillary electrophoresis and fluorescence anisotropy competitive immunoassay for glucagon.

Glucagon plays a crucial role in regulating glucose homeostasis; unfortunately, the mechanisms controlling its release are still unclear. Capillary electrophoresis (CE)- and fluorescence anisotropy (FA)-immunoassays (IA) have been used for online measurements of hormone secretion on microfluidic platforms, although their use in glucagon assays is less common. We set out to compare a glucagon-competitive IA using these two techniques. Theoretical calibration curves were generated for both CE- and FA-IA and results indicated that CE-IA provided higher sensitivity than FA-IA. These results were confirmed in an experiment where both assays showed limits of detection (LOD) of 30nM, but the CE-IA had ∼300-fold larger sensitivity from 0 to 200nM glucagon. However, in online experiments where reagents were mixed within the device, the sensitivity of the CE-IA was reduced ∼3-fold resulting in a higher LOD of 70nM, whereas the FA-IA remained essentially unchanged. This lowered sensitivity in the online CE-IA was likely due to poor sampling by electroosmotic flow from the high salt solution necessary in online experiments, whereas pressure-based sampling used in FA-IA was not affected. We conclude that FA-IA, despite lowered sensitivity, is more suitable for online mixing scenarios due to the ability to use pressure-driven flow and other practical advantages such as the use of larger channels.

Circulating Extracellular Vesicles Are Elevated with Prediabetes and Adversely Affect Cerebral Endothelial Nitric Oxide and Endothelin-1 Production

Experimental and clinical studies indicate that a proatherogenic endothelial phenotype develops in the prediabetic, hyperglycemic state providing the platform for accelerated vascular disease with prediabetes and, in turn, type 2 diabetes. Prediabetes (fasting plasma glucose concentrations: 100-125 mg/dL) is associated with an increased risk of stroke. Circulating endothelial cell-derived microvesicles (EMVs) are now recognized as both a biomarker and mediator of vascular health and disease. In fact, EMVs have been shown to be involved in the pathogenesis of cerebrovascular dysfunction leading to increased stroke risk. Circulating EMVs are elevated in adults with prediabetes; whether EMVs associated with the prediabetic state promote endothelial abnormalities known to increase stroke risk is unknown. The experimental aim of this study was to determine the effect of EMVs isolated from adults with prediabetes on brain endothelial cell nitric oxide (NO) and endothelin (ET)-1 production. Circulating EMVs (CD144-PE) were isolated (flow cytometry) from 20 mid-life adults (age:44-69 yr): 10 normoglycemic (NG; 8M/2F; age: 55±2 yr; BMI: 25.7±0.8 kg/m2; fasting plasma glucose: 87±2 mg/dL) and 10 prediabetic (PreD: 8M/2F; 55±2 yr; 27.1±1.5 kg/m2; 107±2 mg/dL). Human cerebral microvascular endothelial cells (hCMECs) were cultured and separately treated with EMVs from each subject. Expression of intracellular proteins of interest was determined by capillary electrophoresis immunoassay. Circulating EMV concentrations were significantly higher (~65%) in PreD vs NG (180±25 vs 110±13 EMV/μL) and significantly associated with plasma glucose concentrations (r=0.48; P=0.03). Phosphorylation is the primary posttranslational modification regulating eNOS enzyme activity. Phosphorylation of Ser1177 confers the greatest activation of eNOS; whereas, phosphorylation at Thr495 reduces eNOS activation. Expression of p-eNOS (Ser1177) was lower (47.6±2.6 vs 58.6±3.5 AU; P=0.02) and p-eNOS (Thr495) higher (82.6±4.4 vs 31.1±2.5 AU; p<0.001) in cells treated with EMVs from PreD vs NG. Concordantly, NO production was ~20% lower (6.0±0.2 vs 7.2±0.4 μmol/L; p<0.05) in cells treated with EMVs from PreD adults. PreD-associated EMVs also significantly increased (~25-70%) the expression of Big ET-1 (804.4±47.7 vs 656.7±30.7 AU) and endothelin converting enzyme (290.0±24.6 vs 169.6±19.0 AU) as well as ET-1 production (30.2±4.3 vs 24.2±2.0 pg/mL) in hCMECs. In summary, EMVs harvested from adults with PreD reduced endothelial nitric oxide synthase (eNOS) activation and NO production and increased ET-1 synthesis and release in brain endothelial cells in vitro. Increased risk and incidence of stroke associated with prediabetes may be mediated by circulating EMVs. This is the full abstract presented at the American Physiology Summit 2024 meeting and is only available in HTML format. There are no additional versions or additional content available for this abstract. Physiology was not involved in the peer review process.

Elevated Glucose Levels Increase Oxidative Stress in Human Cerebral Microvascular Endothelial Cells

Although glucose is the primary fuel source for cerebral metabolism and function, chronic exposure to high glucose levels impairs cerebral endothelial cell function and increases the risk of cerebrovascular accidents (CVA). Indeed, hyperglycemia is linked to an increased risk and prevalence of ischemic stroke, primarily attributed to the detrimental impact of glucose on cerebral endothelial cell function. The direct and indirect effects of glucose on brain endothelial cells are complex and not well understood. It is known that hyperglycemia can induce a profound pro-oxidative state with deleterious effects on peripheral vascular function resulting in pathologic outcome. The experimental aim of this study was to determine, in vitro, the effect of elevated glucose concentrations on cerebral endothelial cell oxidative stress. Human cerebral microvascular endothelial cells (hCMECs) were cultured (3rd passage) and incubated with culture media containing 5 mM D-glucose (normal glucose condition [NG]), 6.5 mM glucose (concentration representative of impaired fasting glucose [IFG]), and 8 mM (concentration representative of type 2 diabetes [T2D]) for 3 hours. Cells were harvested and intracellular reactive oxygen species (ROS) production was determined using CellROX Deep Red Reagent and expression of key anti-oxidant defense proteins, superoxide dismutase 1 (SOD-1) and catalase, were determined by capillary electrophoresis immunoassay. In separate experiments, the effect of each glucose condition was determined in the presence of the ROS scavenger, vitamin C (200 μmol). Cells treated with glucose concentration representing IFG (137+8 %) and T2D (162+12%) significantly increased intracellular ROS compared with NG (98+3 %). Concordantly, expression of SOD-1 and catalase were significantly higher in hCMECs treated with glucose concentration representing IFG (190.2+17.8 AU; 134.7+15.4 AU, respectively) and T2D (186.7+19.6 AU; 137.2+17.5 AU, respectively) compared with NG (24.4+1.8 AU; 65.6+4.3 AU, respectively). Pretreatment of cells with vitamin C prevented the increase in ROS in both the IFG and T2D conditions. Of note, there were no significant differences in ROS or the expression of SOD-1 and catalase in hCMECs between the IFG and T2D glucose conditions. In conclusion, glucose concentrations associated with IFG and T2D markedly increased ROS in hCMECs. In addition, there was a compensatory increase in SOD-1 and catalase to counteract the increase in cellular oxidative burden. Similar effects between the IFG and T2D glucose conditions on the oxidative milieu of hCMECs is consistent with the similar clinical cerebrovascular risk burden between these pathologic conditions. Glucose-induced increased oxidative stress in cerebral endothelial cells may contribute to the increased risk of CVA, such as ischemic stroke, associated with IFG and T2D. This is the full abstract presented at the American Physiology Summit 2024 meeting and is only available in HTML format. There are no additional versions or additional content available for this abstract. Physiology was not involved in the peer review process.

Effect of Circulating Extracellular Vesicles from Adults with Spinal Cord Injury on Pulmonary Artery Endothelial Cell Function

Spinal cord injury (SCI) is associated with an increased risk and prevalence of cardiopulmonary and cerebrovascular disease-related morbidity and mortality. Despite an improved understanding of the neurological and physical consequences associated with SCI, factors that initiate, promote and accelerate cardiopulmonary disease are poorly understood. It has become apparent that the increased incidence of pulmonary disorders in adults with chronic SCI is not solely due to worsening of traditional risk factors, but also involves ill-defined factors. Several studies have implicated circulating endothelial cell-derived microvesicles (EMVs) in the etiology of cardiopulmonary diseases. We have previously reported that circulating EMVs are elevated in adults with chronic SCI and the expression of their microRNA cargo promotes disease. Reduction in pulmonary nitric oxide (NO) bioavailability and increased endothelin (ET)-1 production underly many cardiopulmonary disorders associated with SCI. The experimental aim of this study was to determine the effect of EMVs isolated from adults with chronic tetraplegic SCI on pulmonary endothelial cell NO and ET-1 production. As part of an ongoing study, circulating EMVs (CD144-PE) were isolated (flow cytometry) from 7 non-injured adults (all male; age: 38±4 yr) and 7 motor complete SCI adults with tetraplegic SCI (male; 44±5 yr). All subjects were free of overt cardiometabolic disease. Human pulmonary artery endothelial cells (HPAECs) were cultured and separately treated with EMVs from each subject for 24 hr. Expression of intracellular NO and ET-1 proteins of interest was determined by capillary electrophoresis immunoassay. Circulating EMV concentrations were significantly higher (~200%) in SCI vs non-injured (154±36 vs 54±7 EMV/μL). Expression of p-eNOS (Ser1177), the primary activation site for eNOS, was ~30% lower (96.0±2.3 vs 140.7±8.9 AU; p<0.01) and p-eNOS (Thr495), primary inhibitory site, ~40% higher (40.7±1.7 vs 28.8±3.1 AU; p<0.01) in cells treated with EMVs from SCI vs non-injured. As a result, NO production was ~20% lower (6.5±0.3 vs 8.3±0.7 μmol/L; P=0.03) in HPAECs treated with EMVs from adults with SCI. SCI-associated EMVs also significantly increased (~70%) the expression of Big ET-1 (60.6±3.6 vs 36.1±2.7 AU) resulting in enhanced endothelial ET-1 production (884.0±22.9 vs 778.7±18.0 pg/mL). In conclusion, EMVs harvested from adults with SCI markedly reduced eNOS activation and NO production and increased ET-1 synthesis and release in pulmonary endothelial cells in vitro. Circulating EMVs represent a potential mechanistic factor underlying pulmonary disorders and increased disease risk with SCI. This is the full abstract presented at the American Physiology Summit 2024 meeting and is only available in HTML format. There are no additional versions or additional content available for this abstract. Physiology was not involved in the peer review process.

Twenty years of islet-on-a-chip: microfluidic tools for dissecting islet metabolism and function.

Pancreatic islets are metabolically active micron-sized tissues responsible for controlling blood glucose through the secretion of insulin and glucagon. A loss of functional islet mass results in type 1 and 2 diabetes. Islet-on-a-chip devices are powerful microfluidic tools used to trap and study living ex vivo human and murine pancreatic islets and potentially stem cell-derived islet organoids. Devices developed over the past twenty years offer the ability to treat islets with controlled and dynamic microenvironments to mimic in vivo conditions and facilitate diabetes research. In this review, we explore the various islet-on-a-chip devices used to immobilize islets, regulate the microenvironment, and dynamically detect islet metabolism and insulin secretion. We first describe and assess the various methods used to immobilize islets including chambers, dam-walls, and hydrodynamic traps. We subsequently describe the surrounding methods used to create glucose gradients, enhance the reaggregation of dispersed islets, and control the microenvironment of stem cell-derived islet organoids. We focus on the various methods used to measure insulin secretion including capillary electrophoresis, droplet microfluidics, off-chip ELISAs, and on-chip fluorescence anisotropy immunoassays. Additionally, we delve into the various multiparametric readouts (NAD(P)H, Ca2+-activity, and O2-consumption rate) achieved primarily by adopting a microscopy-compatible optical window into the devices. By critical assessment of these advancements, we aim to inspire the development of new devices by the microfluidics community and accelerate the adoption of islet-on-a-chip devices by the wider diabetes research and clinical communities.

Recent Progress of Metal-Organic Framework-Assisted Sensing System for Point-of-Care Antibiotics Detection in Food Industry; a Mini Review

Antibiotics (ANBs) are essential for animal health and are used for treatment, prevention, and growth promotion. However, ANB use in animals can lead to antibiotic residue in food products, which can cause various side effects. These include the transfer of ANB-resistant bacteria to humans, immunopathological effects, allergies, and even carcinogenicity. The most significant adverse effect is the transfer of ANB-resistant bacteria to humans due to the mobile properties of resistance. Therefore, timely detection is the best approach to prevent the spread of downsides of these compounds. Various methods exist for measuring ANB concentrations, such as LC-MS, high-performance liquid chromatography, capillary electrophoresis, thin-layer chromatography, and enzyme-linked immunoassay. However, complicated sample preparation processes and expensive equipment are often considered obstacles to their prevalent usage. Emerging technologies like Metal-Organic Frameworks (MOFs) offer a simpler, quicker, and more cost-effective solution for detecting veterinary drugs in animal-derived food samples. This investigation first reviews some conventional methods for ANB recognition, including microbiological, immunological, and laboratory-based procedures. Then, Sensor-based analytical methods and their advantages and disadvantages were discussed. Finally, the recent progress in ANB detection approaches using MOF-based sensors in food products was investigated. MOFs have become a topic of great interest due to their remarkable properties. These include high surface areas that can be easily modified, defined porosity, lightweight, adjustable pore sizes, ordered structures, and impressive mechanical strength. The performance of MOFs is superior to traditional chemosensory materials due to their ability to adjust properties. Various sensing systems based on MOFs have been reported, including photoelectrochemical, electrochemiluminescence, electrochemical, and quartz crystal microbalance. As discussed in this review, sensors based on MOFs have emerged as reliable alternatives for fast and routine detection in clinical and environmental analysis and food safety control. Various MOF-based materials have been used for detecting antibiotics, and their advantages and limitations have been critically evaluated for future applications in diagnosing antibiotics in food products.

MCP-1/CCR2 axis is involved in the regulation of γδT cells in lupus nephritis.

γδT cells are important innate immune cells that are involved in the occurrence and development of autoimmune diseases such as systemic lupus erythematosus (SLE). Lupus nephritis (LN) is a serious complication of SLE, characterized by the accumulation of immune cells (including γδT cells) in the target organs to participate in the disease process. Therefore, clarifying how γδT cells chemotactically migrate to target organs may be a key to developing therapeutic methods against LN. Enzyme-linked immunosorbent assay (ELISA) was used to detect serum levels of chemokines in LN patients and healthy controls. Real-time polymerase chain reaction (RT-PCR) and flow cytometry were used to measure the expression of chemokine receptors on the surface of γδT cells. The chemotactic migration ability of γδT cells was detected by Transwell assay. Signalling pathway activation of γδT cells was detected by Automated Capillary Electrophoresis Immunoassay and flow cytometry. The serum levels of chemokines, including monocyte chemoattractant protein-1 (MCP-1) in LN patients, were significantly increased. CCR2, the receptor of MCP-1, was also highly expressed on the surface of peripheral γδT cells in LN patients. In addition, the exogenous addition of MCP-1 can enhance chemotactic migration of γδT cells in LN patients. MCP-1 could activate STAT3 signalling in LN patients' peripheral γδT cells. γδT cells might participate in the pathogenesis of LN through MCP-1/CCR2 axis. This finding provides new opportunities for developing treatment methods against LN by targeting MCP-1/CCR2 axis.

Age-related elevation of HGF is driven by the reduction of fibroblast size in a YAP/TAZ/CCN2 axis-dependent manner

BackgroundAged human skin is primarily attributable to the loss of collagen. Hepatocyte growth factor (HGF) acts as an anti-fibrotic factor by suppression of collagen production. In aged human skin, HGF is elevated in dermal fibroblasts and thus contributes to dermal aging (thin dermis) by suppression of collagen production. ObjectiveWe aimed to investigate the underlying mechanisms of age-related elevation of HGF expression. MethodsCollagen fibrils in the aged skin dermis are fragmented and disorganized, which impairs collagen-fibroblast interaction, resulting in reduced fibroblast spreading and size. To explore the connection between reduced dermal fibroblast size and age-related elevation of HGF expression, we manipulate dermal fibroblast size, and cell-size dependent regulation of HGF was investigated by laser capture microdissection, immunostaining, capillary electrophoresis immunoassay, and quantitative RT-PCR. ResultsWe found that reduced fibroblast size is responsible for age-related elevation of HGF expression. Further investigation indicated that cell size-dependent upregulation of HGF expression was mediated by impeded YAP/TAZ nuclear translocation and their target gene, CCN2. Conversely, restoration of dermal fibroblast size rapidly reversed cell-size-dependent upregulation of HGF in a YAP/TAZ-dependent manner. Finally, we confirmed that elevated HGF expression is accompanied by the reduced expression of YAP/TAZ and CCN2 in the aged human skin in vivo. ConclusionAge-related elevation of HGF is driven by the reduction of fibroblast size in a YAP/TAZ/CCN2 axis-dependent manner. These data reveal a novel mechanism by which reduction of fibroblast size upregulates HGF expression, which in turn contributes to loss of collagen, a prominent feature of aged human skin.

Indirect capillary electrophoresis immunoassay of membrane protein in extracellular vesicles.

Extracellular vesicles (EVs) exist in biological fluids such as blood, urine, and cerebrospinal fluid, and these have shown promise for use as biomarkers of cancers. Conventional methods for determination of EVs include direct detection via enzyme-linked immunosorbent assay and detection of their membrane proteins via western blotting. These techniques, however, have individual shortcomings in terms of the need for large sample consumption, processes that are time-consuming, and a lack of the capacity for quantification. In this study, we developed a method to determine the EV membrane protein, CD63, by coupling capillary electrophoresis immunoassay with laser-induced fluorescence (CEIA-LIF). In this process, the EVs were isolated from a culture medium and were subsequently reacted with a fluorescently labeled anti-CD63 antibody to form a CD63 complex localized on the surface of EVs. After removing the EVs containing the CD63 immune complex by centrifugation, the supernatant containing the free fluorescent antibody was injected into a capillary to serve as a sample. A decrease in the peak area of the free fluorescent antibody became apparent when the amount of EVs was increased while that of the fluorescent antibody remained constant. The peak areas were decreased proportionally against the increased amounts of EVs. The concentration of the CD63 could then be estimated based on the slope of the linear relationship. This study is the first to quantify CD63 immobilized on EVs via CEIA-LIF, which is a novel method with the potential to determine membrane proteins localized on the surface of EVs.

Effect of Zhenxin Xingshui Yizhi Fang on Aβ25-35 induced expression of related transporters in HBMEC cell model

Ethnopharmacological relevanceAβ (β-amyloid) deposition and abnormal transport were suggested to be risk factors for Alzheimer's disease (AD). Zhenxin Xingshui Yizhi Fang (XSF), an ancient prescription in traditional Chinese medicine, was first recorded in Qianjin Yifang for treating palpitation, hypnosia, amnesia. It is reported that XSF could improve mice learning memory ability, reduce the deposition of senile plaques in hippocampus of rat brain. In this study, the neuroprotective effect of XSF against Aβ25-35-induced apoptosis in cultured human brain microvascular endothelial cells (HBMEC) and its potential mechanism were investigated. Materials and methodsHBMEC cells were treated with Aβ25-35 to established neurotoxic cell model. After that, the cells were treated with 125, 250, 500 μg/mL XSF to observe the protective effect. The viability of HBMEC cells were evaluated by MTT assay, the Aβ25-35-induced apoptosis was characterized by Hoechst-33258 and the activity of cysteinyl aspartate specific proteinase-3. The expression level of Aβ1-42 in cells induced by Aβ25-35 was measured by human Aβ1-42 kit. Protein and mRNA expression levels of advanced glycation end products (RAGE), low density lipoprotein receptor-related protein 1 (LRP1), glucose transporter 1 and 3 (GLUT1 and GLUT3) were assayed by capillary electrophoresis immunoassay and quantitative real-time polymerase chain reaction analyses. ResultsIn Aβ25-35 induced neurotoxic cells, the percentage of apoptotic cells, the concentration of Aβ1-42 and CASPASE-3 activity, protein and mRNA expression levels of RAGE increased significantly, but that of LRP1, GLUT1 and GLUT3 significantly decreased. XSF could inhibit the apoptotic of cells, reduced the concentration of Aβ1-42 and CASPASE-3 expression, downregulate RAGE and upregulate LRP1, GLUT1 and GLUT3 expression. ConclusionThe results suggest that XSF can reduce the cytotoxicity of HBMEC induced by Aβ25-35, inhibit apoptosis, and regulate the transport of Aβ on BBB and energy metabolism disorder in HBMEC.

Use of Capillary Electrophoresis Immunoassay to Search for Potential Biomarkers of Amyotrophic Lateral Sclerosis in Human Platelets.

Capillary electrophoresis immunoassay (CEI), also known as capillary western technology, is becoming a method of choice for screening disease relevant proteins and drugs in clinical trials. Reproducibility, sensitivity, small sample volume requirement, multiplexing antibodies for multiple protein labeling in the same sample, automated high-throughput ability to analyze up to 24 individual samples, and short time requirement make CEI advantageous over the classical western blot immunoassay. There are some limitations of this method, such as the inability to utilize a gradient gel (4%-20%) matrix, high background with unrefined biological samples, and commercial unavailability of individual reagents. This paper describes an efficient method for running CEI in a multiple assay setting, optimizing protein concentration and primary antibody titration in one assay plate, and providing user-friendly templates for sample preparation. Also described are methods for measuring pan TDP-43 and phosphorylated TDP-43 derivative in platelet lysate cytosol as part of the initiative in blood-based biomarker development for neurodegenerative diseases.

Use of Capillary Electrophoresis Immunoassay to Search for Potential Biomarkers of Amyotrophic Lateral Sclerosis in Human Platelets

Use of Capillary Electrophoresis Immunoassay to Search for Potential Biomarkers of Amyotrophic Lateral Sclerosis in Human Platelets

1938P - Characterization of the mechanism of action and efficacy of MEN1611 (PA799), a novel PI3K inhibitor, in breast cancer preclinical models

BackgroundThe phosphatidylinositol 3-kinase (PI3K) pathway plays a central role in cell proliferation and survival in human cancer. Mutations in PIK3CA, the gene coding the p110α catalytic subunit of PI3K, are frequent in cancer and result in PI3K pathway activation. About 25% of HER2-positive breast cancers also carry PIK3CA mutations, known to confer resistance to anti-HER2 therapy. Here we report the preclinical characterization of MEN1611, a potent and selective orally available PI3K inhibitor, showing high activity against p110α mutant isoforms and sparing the δ isoform. MethodsIn vivo efficacy studies were evaluated through Tumour Volume Inhibition % (TVI%) and mRECIST criteria using cancer cell lines and patient-derived xenograft (PDX) models. Pathway activation and protein degradation analyses were performed by western blot and capillary electrophoresis immunoassay. Immune modulation was evaluated using murine macrophages differentiated in vitro. ResultsConsistent with its mechanism of action, MEN1611 down-modulates the PI3K/AKT signaling as well as selected downstream targets, both in vitro and in vivo. MEN1611 acts synergistically when combined with trastuzumab in several HER2-positive PIK3CA-mutated breast cancer cell lines and patient-derived xenograft models. The in vivo efficacy in trastuzumab-resistant models is supported by a long-lasting antitumor activity, paralleled by mechanistic down-regulation of pharmacodynamic biomarkers. Moreover, MEN1611 showed the ability to induce a dose-dependent alpha-isoform depletion, and to modulate the macrophage polarization towards a pro-inflammatory phenotype, consistent with its capability to co-inhibit P110γ. ConclusionsOverall, these preclinical data support the progression in the development of MEN1611 in breast cancer and pave the way to the B-Precise-01 clinical study, a multicentre phase Ib study. Clinical trial identificationNCT03767335. Legal entity responsible for the studyMenarini Ricerche S.p.A. FundingMenarini Ricerche S.p.A. DisclosureA. Fiascarelli: Full / Part-time employment: Menarini RIcerche S.p.A. G. Merlino: Full / Part-time employment: Menarini Ricerche S.p.A. S. Capano: Full / Part-time employment: Menarini Ricerche S.p.A. A. Paoli: Full / Part-time employment: Menarini Ricerche S.p.A.. A. Bressan: Full / Part-time employment: Menarini Ricerche. M. Bigioni: Full / Part-time employment: Menarini Ricerche S.p.A.. M. Scaltriti: Advisory / Consultancy: Memorial Sloan-Kettering Cancer Center. J. Arribas: Advisory / Consultancy: Vall d’Hebron Institute of Oncology. C. Bernadó Morales: Advisory / Consultancy: Vall d’Hebron Institute of Oncology. A. Pellacani: Leadership role, Full / Part-time employment: Menarini Ricerche S.p.A.. M. Salerno: Leadership role, Full / Part-time employment: Menarini Ricerche. M. Binaschi: Leadership role, Full / Part-time employment: Menarini Ricerche S.p.A.

Determination of AR-V7 in plasma in patients with metastatic prostate cancer using capillary Nano-immunoassay.

e16574 Background: Liquid biopsy has the potential to provide information about cancers without invasive biopsy, using circulating biomarkers. The aim of present study was determinate the presence of androgen receptor splice variant 7 (AR-V7) in plasma using capillary nano-immunoassay in metastasis PCa and correlation with clinical and analytical data. Methods: Whole blood (10 ml) was collected and processed in EDTA tubes. Previously to determinate the presence of ARV-7 in plasma Capillary Electrophoresis Immunoassay or SimpleWestern analyses were performed using the WES™ machine. With this technique, proteins are separated by size, immobilised and probed with specific antibodies. The primary antibody used was Anti-Androgen Receptor antibody. Results: The study included 31 patients with diagnostic of PCa metatasic . Clinical characteristics of the patients were described in the table. AR-V7 signal was detected in 11 cases (36%). Twenty samples (64%) were considered as negative. The most of patients with expression positive for AR-V7, showed a Gleason score ≥ 8 (64% of cases). In AR-V7+, hemoglobine and dehydrogenase lactate levels were statistically significant (p < 0,05) respect to ARV7-. So, in AR-V7+ patients showed increased of FA and Albumin. Conclusions: Assessing the presence of AR-V7 in plasma from PC patients is feasible by a novel capillary nano-immunoassay. AR-V7 was observed in 36% of the PCA metastasic. These findings lay the foundations for liquid biopsy as a means of obtaining biological data in a more convenient way for the patient.[Table: see text]

8O - 89Zr-labeled anti-PD-L1 CX-072 PET imaging in human xenograft and syngeneic tumors

Background: Immune checkpoint inhibiting antibodies have antitumor activity across several tumor types, but can also elicit immune-mediated adverse events (imAEs). CX-072 is an investigational antibody prodrug (Probody™ therapeutic), reactive to the murine and human programmed death-ligand 1 (PD-L1) immune checkpoint. CX-072 can be activated to a fully avid antibody by tumor-associated proteases that remove the masking peptides blocking the antigen-binding domain, which may limit peripheral PD-L1 binding and therefore imAEs. CX-072 was radiolabeled with zirconium-89 (89Zr) to study its biodistribution and tumor- versus lymphoid tissue-targeting properties using positron emission tomography (PET). Methods: CX-072, non-specific Probody™ therapeutic control (PbCtrl) and CX-072 parental antibody (CX-075) were radiolabeled with 89Zr. Human PD-L1-expressing MDA-MB-231 tumor-bearing BALB/c nude mice received 10 μg 89Zr-CX-072, 89Zr-PbCtrl or 89Zr-CX-075 (∼5 MBq) supplemented with 0, 40 or 240 µg of respective unlabeled antibody. Biodistribution was also evaluated in C57BL6/J mice bearing PD-L1-expressing MC38 syngeneic colon adenoma tumors. Mice underwent PET scans 1, 3 and 6 days post intravenous injection (pi), followed by ex vivo analysis. Results: In MDA-MB-231 tumors, 89Zr-CX-072 and 89Zr-CX-075 showed comparable uptake of 8.7 ± 1.0%ID/g and 8.8 ± 2.9%ID/g respectively for the 10 µg total protein dose, which is 2.3-fold higher compared to 89Zr-PbCtrl. Autoradiography showed 89Zr-CX-072 localization in PD-L1-positive tumor tissue areas on immunohistochemistry. Activated CX-072 was detected by capillary electrophoresis immunoassay mainly in MDA-MB-231 tumor, with limited amounts found in spleen. Flow cytometry confirmed PD-L1 expression in lymphoid tissues of C57BL6/J mice, while 89Zr-CX-072 uptake in these tissues was similar to 89Zr-PbCtrl and significantly lower compared to 89Zr-CX-075. Conclusions:89Zr-CX-072 accumulates in PD-L1-expressing tumors with minor uptake in murine peripheral lymphoid tissues, confirming that the CX-072 structure limits uptake in non-tumor, PD-L1-expressing tissues. We developed clinical grade 89Zr-CX-072 to study its whole-body distribution in patients. Legal entity responsible for the study: Dept. of Medical Oncology, University Medical Center Groningen (UMCG), The Netherlands. Funding: CytomX Therapeutics Inc. Disclosure: I. Popova, B. Howng, O. Vasiljeva: Employee: CytomX Therapeutics Inc. E.G.E. de Vries: Research funding: CytomX was made available to her institution (UMCG); Advisory boards: Pfizer, Daiichi Sankyo; Other funding: Amgen, Bayer, Chugai, G1 Therapeutics, Genentech/Roche, Nordic Nanovector, Regeneron, Synthon, all payments to UMCG. All other authors have declared no conflicts of interest.

False measurement of glycated hemoglobin in patients without hemoglobin A.

Background: Hemoglobin (Hb) A1c, a biochemical marker widely used in monitoring diabetes mellitus, can be quantitatively measured by various examining systems. However, significant errors still exist. In the present study, we evaluated the HbA1c level in five patients with compound heterozygotes by five different examining systems and our goal is to identify the existence of erroneous HbA1c measurement.Methods: Blood samples collected from normal (no hemoglobin variants) and abnormal (compound heterozygotes) patients were analyzed by capillary electrophoresis technique and sequence analysis. The samples without HbA expression via above methods were further analyzed for HbA1c by ion exchange HPLC Variant II/ Variant II Turbo 2.0 (VII and VII-T 2.0), boronate affinity HPLC, capillary electrophoresis, and Tinaquant immunoassay.Results: HbA1c expression were unexpectedly detected in the compound heterozygous samples by using additional examining systems: The HPLC VII and VII-T 2.0 detected HbA1c expression in two of five samples and failed to detect the abnormal HbA2 expression; the CE system detected HbA1c expression in one of five samples with abnormal HbA2 expression; the Ultra2 and PPI system detected the HbA1c expression of all samples without abnormal HbA2.Conclusions: Five human samples without HbA expression were additionally detected with HbA1c expression with or without abnormal HbA2 expression by five analysis systems and the different examining assay potentially affected the test results. These results demonstrated that the limitations of current examining systems for monitoring patients with hemoglobin disorders highlighting the further improvement in the method of clinical HbA examination.

Wenyang Huoxue Jiedu formula inhibits thin-cap fibroatheroma plaque formation via the VEGF/VEGFR signaling pathway

Ethnopharmacological relevanceFor many years, Guangzhou University of Chinese Medicine has been successfully using the empirical Wenyang Huoxue Jiedu formula (WHJF) to treat coronary heart disease. Modern theories of acute coronary syndrome mainly focus on rupture of thin-cap fibroatheromas (TCFAs), which is closely related to the release of vascular endothelial growth factor and its receptor (VEGF/VEGFR). Aim of studyWe investigated the effects of WHJF on the formation of TCFA plaques and the potential mechanism (VEGF/VEGFR signaling pathway). Materials and methodsFor the in vivo experiments, WHJF was administered to ApoE-/- mice, as a model of TCFA plaque formation. Aortic sections of the mice were obtained, and the vulnerability index and new vessel density of plaques were calculated by the Movat staining assay and immunohistochemistry kit, respectively. Protein and mRNA expression levels of VEGF/VEGFR in aortas were assayed by capillary electrophoresis immunoassay and quantitative real-time polymerase chain reaction analyses. In vitro, WHJF serum was produced in rats on the fourth day 2 h after the first administration of different concentrations of WHJF. Proliferation, migration, and lumen formation ability of human umbilical vein endothelial cells (HUVECs) treated with sera from these rats were assayed by the CKK-8 kit, Transwell plates, and Matrigel assay, respectively. Protein and mRNA expression levels of signaling molecules in the VEGF/VEGFR pathways were also examined. ResultsIn vivo, the vulnerability index and new vessel density of plaques in the WHJF group were lower than those values in the blank control group (P < 0.05). No differences were found between the groups in the expression levels of VEGF/VEGFR (P > 0.05). In vitro, the proliferation, migration, and tube formation of HUVECs in the high-dose WHJF group were reduced compared to the control group (P < 0.05). This finding was in agreement with the downregulation of VEGFR-2 and pERK (P < 0.05). The mRNA expression of signaling molecules showed no difference between the groups (P > 0.05). ConclusionsWHJF inhibits TCFA formation by influencing the VEGF/VEGFR signaling pathway.

Age-related reduction of dermal fibroblast size upregulates multiple matrix metalloproteinases as observed in aged human skin in vivo.

Fragmentation of collagen fibrils, the major structure protein in skin, is a hallmark of dermal ageing. Matrix metalloproteinases (MMPs) are largely responsible for the fragmentation of collagen fibrils. To quantify gene expression of all 23 known mammalian MMPs in sun-protected young and aged human skin in vivo and to investigate the potential mechanism underlying age-related alteration of multiple MMPs. MMP mRNA expression levels and MMP activity in sun-protected young and aged human skin in vivo were determined by real-time reverse transcription polymerase chain reaction (RT-PCR) and in situ zymography, respectively. The relative contributions to elevated MMPs in epidermis and dermis were quantified by laser capture microdissection coupled real-time RT-PCR. Dermal fibroblast morphology and collagen fibril fragmentation in human skin in vivo were assessed by second-harmonic generation microscopy and atomic force microscopy, respectively. In vitro cell morphology was assessed by CellTracker® fluorescent dye (Molecular Probes, Eugene, OR, U.S.A.) and phalloidin staining. Protein levels were determined by ProteinSimple capillary electrophoresis immunoassay (ProteinSimple, Santa Clare, CA, U.S.A.). Multiple MMPs are elevated in aged human skin dermis. Increased MMP activity and collagen fibril fragmentation were observed in aged skin dermis. As dermal fibroblasts are the major MMP-producing cells in the dermis, reduction of dermal fibroblast size, which is observed in aged human skin, contributes to the elevation of age-related multiple MMPs. Reduction of fibroblast size upregulates c-Jun/c-Fos and activates AP-1. Combined actions of the wide variety of MMPs that are constitutively elevated in aged dermis may be involved in the progressive degradation of dermal collagen fibrils. Age-related elevations of multiple MMPs are likely to be a result of the reduction of fibroblast size via activation of AP-1.

A highly sensitive capillary electrophoresis immunoassay strategy based on dual-labeled gold nanoparticles enhancing chemiluminescence for the detection of prostate-specific antigen.

An enzyme and antibody dual labeled gold nanoparticles enhancing chemiluminescence strategy was developed for highly sensitive CE immunoassay (IA) of prostate-specific antigen (PSA). In this work, gold nanoparticles were labeled with horseradish peroxidase and antiprostate specific antigen-antibody, and used as the marker (Ab* ). After PSA (antigen, Ag) was added into the system, a noncompetitive immune reaction was happen between Ab* and Ag to form an immune complex (Ag-Ab* ). Subsequently, the obtained Ag-Ab* and unreacted Ab* were separated by CE, and the chemiluminescence intensity of Ag-Ab* was used to estimate PSA concentration. The calibration curve showed a good linearity in the range of 0.25-10ng/mL. Based on a S/N of 3, the detection limit for PAS was estimated to be 0.092ng/mL. Proposed CE method was applied for PSA quantification in human serum samples from healthy volunteers and patients with prostate cancer. The obtained results demonstrated that the proposed CE method may serve as an alternative tool for clinical analysis of PSA.

DEPTOR maintains plasma cell differentiation and favorably affects prognosis in multiple myeloma

BackgroundThe B cell maturation process involves multiple steps, which are controlled by relevant pathways and transcription factors. The understanding of the final stages of plasma cell (PC) differentiation could provide new insights for therapeutic strategies in multiple myeloma (MM). Here, we explore the role of DEPTOR, an mTOR inhibitor, in the terminal differentiation of myeloma cells, and its potential impact on patient survival.MethodsThe expression level of DEPTOR in MM cell lines and B cell populations was measured by real-time RT-PCR, and/or Western blot analysis. DEPTOR protein level in MM patients was quantified by capillary electrophoresis immunoassay. RNA interference was used to downregulate DEPTOR in MM cell lines.ResultsDEPTOR knockdown in H929 and MM1S cell lines induced dedifferentiation of myeloma cells, as demonstrated by the upregulation of PAX5 and BCL6, the downregulation of IRF4, and a clear reduction in cell size and endoplasmic reticulum mass. This effect seemed to be independent of mTOR signaling, since mTOR substrates were not affected by DEPTOR knockdown. Additionally, the potential for DEPTOR to be deregulated in MM by particular miRNAs was investigated. The ectopic expression of miR-135b and miR-642a in myeloma cell lines substantially diminished DEPTOR protein levels, and caused dedifferentiation of myeloma cells. Interestingly, the level of expression of DEPTOR protein in myeloma patients was highly variable, the highest levels being associated with longer progression-free survival.ConclusionsOur results demonstrate for the first time that DEPTOR expression is required to maintain myeloma cell differentiation and that high level of its expression are associated with better outcome.Primary samples used in this study correspond to patients entered into GEM2010 trial (registered at www.clinicaltrials.gov as #NCT01237249, 4 November 2010).