Lipocalin Research Articles

Tumor-secreted LCN2 impairs gastric cancer progression via autocrine inhibition of the 24p3R/JNK/c-Jun/SPARC axis

Gastric cancer (GC) is one of the most lethal malignancies worldwide. Despite extensive efforts to develop novel therapeutic targets, effective drugs for GC remain limited. Recent studies have indicated that Lipocalin (LCN)2 abnormalities significantly impact GC progression; however, its regulatory network remains unclear. Our study investigates the functional role and regulatory mechanism of action of LCN2 in GC progression. We observed a positive correlation between LCN2 expression, lower GC grade, and better prognosis in patients with GC. LCN2 overexpression suppressed GC proliferation and metastasis both in vitro and in vivo. Transcriptome sequencing identified secreted protein acidic and rich in cysteine (SPARC) as a pivotal downstream target of LCN2. Mechanistically, c-Jun acted as a transcription factor inducing SPARC expression, and LCN2 downregulated SPARC by inhibiting the JNK/c-Jun pathway. Moreover, LCN2 bound to its receptor, 24p3R, via autocrine signaling, which directly inhibited JNK phosphorylation and then inhibited the JNK/c-Jun pathway. Finally, analysis of clinical data demonstrated that SPARC expression correlated negatively with lower GC grade and better prognosis, and that LCN2 expression correlated negatively with p-JNK, c-Jun, and SPARC expression in GC. These findings suggest that the LCN2/24p3R/JNK/c-Jun/SPARC axis is crucial in the malignant progression of GC, offering novel prognostic markers and therapeutic targets.

Specific expression and blood kinetics for relaxin 2, lipocalin 2, and tissue factor pathway inhibitor 2 at the canine placenta and pregnant bloods.

In general, humoral factors released from the placenta influence pregnancy progression, but the involvement of the canine placenta is often unidentified. We investigated specific genes in canine placentas and analyzed the blood dynamics of the translated proteins. Furthermore, RNAs are known to be released from placentas embedding in exosomes, a type of extracellular vesicles. Here, the presence of cell-free RNAs in pregnant serums was also confirmed. RNA specimens were purified from the normal healthy dog placentas and applied to RNA-Seq analysis. Expressions of frequent genes were confirmed by RT-PCR using placentas from other individuals and breeds. Relaxin (RLN) 2, lipocalin (LCN) 2, and tissue factor pathway inhibitor (TFPI) 2 were selected as high-expressed and placenta-specific genes. By western blot, the three factors were clearly detected in the pregnant serums. Quantitative analysis revealed that the amount of RLN2 increased significantly from non-pregnancy to day 41 of pregnancy. Regarding LCN2 and TFPI2, the protein serum levels elevated during pregnancy, but the statistical differences were not detected. Exosomes were found in all pregnant serums; however, the percentage was less than 6% in total extracellular vesicles. The cell-free RNA related to RLN2 was detected, but no elevation was confirmed during pregnancy. We found specific genes in the canine placenta and the transition of their translated protein into the blood. These factors may become useful tools for research on canine pregnancy and monitoring of reproductive management. Exosomes and cell-free RNA could not be found to be valid in canine reproduction.

Multi-biomarker combination detection system for diagnosis and classification of dry eye disease by imaging of a multi-channel metasurface

Dry eye disease (DED) is one of the most common ocular surface diseases, characterized by unstable tear film and ocular inflammation, affecting hundreds of millions of people worldwide. Currently, the clinical diagnosis of DED mainly relies on physical methods such as optical microscopy and ocular surface interferometric imaging, but classifying DED is still difficult. Here, we propose a compact and portable immune detection system based on the direct imaging of a nanophotonic metasurface with gradient geometry, for fast and ultra-sensitive detection of multiple biomarkers (i.e. Matrix metalloproteinase-9 (MMP-9), Lipocalin-1 (LCN-1), Lactoferrin (LTF)) in tears for the diagnosis and classification of DED. This centimeter-scale concentric nanophotonic metasurface, which consists of millions of unique metallic nanostructures, was fabricated through a cost-effective nanoimprint lithography (NIL) process. The immune detection system based on the antibody-modified metasurface shows favorable detection selectivity, an ultra-high sensitivity (3350 pixels/Refractive Index Unit (RIU)) and low limit of detection (LOD) (0.3 ng/mL for MMP-9, 1 ng/mL for LTF, and 0.5 ng/mL for LCN-1). Further clinical sampling and detection results demonstrated that this multi-biomarker detection system enabled accurate determination and symptom classification of DED, manifesting high correlation and consistency with clinical diagnosis results. The advantages such as low sample consumption, one-step detection, simple operation, and simultaneous detection of multiple biomarkers make the platform promising for screening and detecting a broader range of biomarker combinations in clinical practice.

Systematic review and meta-analysis of mass spectrometry proteomics applied to ocular fluids to assess potential biomarkers of age-related macular degeneration

BackgroundAge-related macular degeneration (AMD) is a significant cause of severe vision loss. The main purpose of this study was to identify mass spectrometry proteomics-based potential biomarkers of AMD that contribute to understanding the mechanisms of disease and aiding in early diagnosis.MethodsThis study retrieved studies that aim to detect differences relate to proteomics in AMD patients and healthy control groups by mass spectrometry (MS) proteomics approaches. The search process was accord with PRISMA guidelines (PROSPERO database: CRD42023388093). Gene Ontology (GO) analysis and Kyoto Encyclopedia of Genes and Genomes Pathway Analysis (KEGG) were performed on differentially expressed proteins (DEPs) in the included articles using the DAVID database. DEPs were included in a meta-analysis when their effect size could be computed in at least two research studies. The effect size of measured proteins was transformed to the log2-fold change. Protein‒protein interaction (PPI) analysis was conducted on proteins that were statistically significant in the meta-analysis using the String online database.ResultsEleven studies fulfilled the inclusion criteria, and 161 DEPs were identified. The GO analysis showed that AMD is significantly related to proteolysis, extracellular exosome and protein binding. In KEGG, the most significant pathway was the complement and coagulation cascades. Meta-analysis results suggested that eight proteins were statistically significant, and according to PPI results, the most significant four proteins were serotransferrin (TF), apolipoprotein A1 (APOA1), complement C3 (C3) and lipocalin-1 (LCN1).ConclusionsFour possible biomarkers, TF, APOA1, C3 and LCN1, were found to be significant in the pathogenesis of AMD and need to be further validated. Further studies should be performed to evaluate diagnostic and therapeutic value of these proteins.

Variation of wine preference amongst consumers is influenced by the composition of salivary proteins

The preferences of consumers for different flavours and aromas in wine are varied and may be explained by inherent factors such as cultural background, wine education and personal taste of the wine consumer. Wine flavour, as perceived in the mouth, includes aroma compounds released through the retronasal pathway, which are shaped by interactions with saliva. Saliva and wine interactions could provide an explanation as to why wine tasters express different preferences for wine. To test this hypothesis, 13 Western and 13 Chinese experienced wine tasters were recruited. Sensory evaluation was performed in formal surroundings to acquire free description-based and perceived sensory intensity data using the Pivot® Profile and continuous scale assessment, respectively. Participants’ saliva samples were collected before the sensory evaluation and spiked into a wine sample to investigate the impact on the wine’s volatile release using comprehensive two-dimensional gas chromatography–mass spectrometry (GC × GC–MS). Saliva samples were subjected to enzyme activity assays and protein composition profiling by Tandem Mass Tag (TMT) quantitative proteomics. The wine tasters showed differences in wine flavour perception, which was supported by the difference in wine volatile release resulting from the addition of saliva. The two groups of participants did not have significant differences in total salivary protein concentrations or the amounts of esterase and α-amylase. However, statistically significant variations in the concentrations of specific proteins (proline-rich proteins (PRPs) and lipocalin-1 (LCN-1); p < 0.01) were found between the two groups. Significant correlations between perceived intensities of wine attributes and concentrations of PRPs and LCN-1 were observed. These results indicate that the composition of proteins in saliva is a factor that influences wine perception and preference. Our results provide a biochemical basis for understanding preference for food based on interactions between aroma compounds and salivary proteins and could be used to suggest foods or beverages to particular cultural groups.

Photonic crystal enhanced immunofluorescence biosensor integrated with a lateral flow microchip: Toward rapid tear-based diabetic retinopathy screening.

Diabetic retinopathy (DR) has accounted for major loss of vision in chronic diabetes. Although clinical statistics have shown that early screening can procrastinate or improve the deterioration of the disease, the screening rate remains low worldwide because of the great inconvenience of conventional ophthalmoscopic examination. Instead, tear fluid that contains rich proteins caused by direct contact with eyeballs is an ideal substitute to monitor vision health. Herein, an immunofluorescence biosensor enhanced by a photonic crystal (PhC) is presented to handle the trace proteins suspended in the tear fluid. The PhC was constructed by self-assembled nanoparticles with a thin layer of gold coated on top of it. Then, the PC substrate was conjugated with antibodies and placed in a microchannel. When the capillary-driven tear sample flew over the PC substrate, the immunoassay enabled the formation of a sandwich antibody-antigen-antibody configuration for PhC-enhanced immunofluorescence. The use of PhC resulted in a concentration enhancement of more than tenfold compared to non-PhC, while achieving an equivalent signal intensity. The limit of detection for the target biomarker, lipocalin-1 (LCN-1), reached nearly 3 μg/ml, and the turnaround time of each detection was 15 min. Finally, a preclinical evaluation was conducted using ten tear samples. A clear trend was observed, showing that the concentrations of LCN-1 were at least twofold higher in individuals with chronic diabetes or DR than in healthy individuals. This trend was consistent with their medical conditions. The results provided a direct proof-of-concept for the proposed PhC biosensor in rapid tear-based DR screening.

Variable dysregulation of circulating lipocalin-2 in different obese phenotypes: Association with vasodilator dysfunction.

Obesity is linked with heightened cardiovascular risk, especially when accompanied by metabolic abnormalities. Lipocalin (LCN) 2 and retinol-binding protein (RBP) 4, two members of the lipocalin family, may be upregulated in insulin resistance and atherosclerosis. We analyzed whether changes in circulating LCN2 and RBP4 in obese individuals relate with impaired vasodilator reactivity, an early stage in atherosclerosis. Obese individuals (n = 165), without (n = 48) or with (n = 117) metabolic abnormalities, and lean subjects (n = 42) participated in this study. LCN2 and RBP4 were measured by Luminex assay. Endothelium-dependent and -independent vasodilation to acetylcholine and sodium nitroprusside, respectively, was assessed by strain-gauge plethysmography. Circulating LCN2 was higher in obese than in lean subjects (p < 0.001), whereas RBP4 was not different between the two groups (p = 0.12). The vasodilator responses to both acetylcholine and nitroprusside were impaired in obese individuals (p < 0.001 vs lean subjects), with no difference between those with metabolically healthy or unhealthy obesity (p > 0.05). In the whole population, vasodilator responses to acetylcholine (R = 0.23, p = 0.01) and nitroprusside (R = 0.38, p < 0.001) had an inverse, linear relationship with circulating LCN2; no correlation, by contrast, was observed between circulating RBP4 and vasodilator reactivity (both p > 0.05). In a subgroup of obese patients with diabetes (n = 20), treatment with metformin (n = 10) or pioglitazone (n = 10) did not modify circulating LCN2 and RBP4 or vascular reactivity (all p > 0.05). Circulating LCN2, but not RBP4, is higher in obese than in lean individuals. Interestingly, changes in LCN2 inversely relate to those in vasodilator function, thereby making this protein a potential biomarker for risk stratification in obesity.

Impact of enteropathogens on faltering growth in a resource-limited setting.

Environmental enteropathy is an important contributor to childhood malnutrition in the developing world. Chronic exposure to fecal pathogens leads to alteration in intestinal structure and function, resulting in impaired gut immune function, malabsorption, and growth faltering leading to environmental enteropathy. A community-based intervention study was carried out on children till 24 months of age in Matiari district, Pakistan. Blood and fecal specimens were collected from the enrolled children aged 3-6 and 9 months. A real-time PCR-based TaqMan array card (TAC) was used to detect enteropathogens. Giardia, Campylobacter spp., enteroaggregative Escherichia coli (EAEC), Enteropathogenic Escherichia coli (EPEC), Enterotoxigenic Escherichia coli (ETEC), and Cryptosporidium spp. were the most prevailing enteropathogens in terms of overall positivity at both time points. Detection of protozoa at enrollment and 9 months was negatively correlated with rate of change in height-for-age Z (ΔHAZ) scores during the first and second years of life. A positive association was found between Giardia, fecal lipocalin (LCN), and alpha 1-Acid Glycoprotein (AGP), while Campylobacter spp. showed positive associations with neopterin (NEO) and myeloperoxidase (MPO). Protozoal colonization is associated with a decline in linear growth velocity during the first 2 years of life in children living in Environmental enteric dysfunction (EED) endemic settings. Mechanistic studies exploring the role of cumulative microbial colonization, their adaptations to undernutrition, and their influence on gut homeostasis are required to understand symptomatic enteropathogen-induced growth faltering.

An aptamer triple helix molecular switch for sensitive electrochemical assay of lipocalin 1 biomarker via dual signal amplifications.

Sensitively monitoring the concentration change of lipocalin 1 (LCN1) can provide data support for accurately diagnosing diabetic retinopathy and efficacy of treatment. Using a new aptamer triplex switch (ATS) probe and catalytic hairpin assembly (CHA) and hybridization chain reaction (HCR) dual signal amplifications, a highly sensitive electrochemical and enzyme-free biosensor for detecting LCN1 is reported. The ATS probes recognize and bind LCN1 to change its structure and release ssDNA sequences, which trigger the capture of methylene blue (MB)-tagged DNA on the sensor electrode via the CHA and HCR reactions. These MB tags are then subjected to electrochemical measurements to obtain highly amplified current outputs to sensitively detect LCN1 from 5 pM to 1 nM with a detection limit of 0.85 pM. This sensor also exhibits high interfering protein discrimination capability and can be employed to monitor low levels of LCN1 in diluted tear samples. Our established sensor significantly outperforms current major LCN1 detection methods based on immunoassays and thus holds promising potential for evaluating the severity of diabetic retinopathy and monitoring treatment response.

Targeted proteomics using parallel reaction monitoring confirms salivary proteins indicative of metastatic triple-negative breast cancer

Triple-negative breast cancer (TNBC) is the most aggressive subtype due to the absence of hormonal receptors. Our study aimed to identify and determine the effectiveness of salivary proteins as candidate markers for metastatic TNBC subtype using parallel reaction monitoring mass spectrometry (PRM-MS). Three salivary proteins (lipocalin-1, SMR3B, and plastin-2) that showed significant differential expression in label-free quantitation (LFQ) between TNBC (N = 6) and health subjects (HS; N = 6) were selected for further validation. The developed PRM assay was used to quantify peptides GLST and NNLE (lipocalin-1), VYAL and MINL (Plastin-2) and GPYP, and IPPP (SMR3B) on a different cohort of TNBC patients (N = 20) and HS (N = 20) for evaluating their discriminating performances. Quantitative validation using PRM correlated well with the LFQ results, and 5 peptides from three proteins showed a similar up-or down-regulation. Subsequently, these proteins were validated by Western blot analysis. Compared to one protein's performance as an individual marker, the five-signature panel with salivary GLST, VYAL, MINL, GPYP, and IPPP achieved better performance in differentiating aggressive TNBC and HS with sensitivity (80%) and specificity (95%). Targeted proteomic analysis of the prioritized proteins highlights a peptide-based signature in saliva as the potential predictor to distinguish between TNBC and HS. Significance of the studyThis study was designed to identify and quantify potential markers in saliva from the triple-negative breast cancer (TNBC) patients using parallel reaction monitoring assay. Three salivary proteins, Lipocalin-1 (LCN-1), Submaxillary androgen-regulated protein 3B (SMR3B), and Plastin-2 (LCP-1) selected in the discovery-phase were further quantified by targeted proteomics and Western blots. The salivary proteins successfully differentiated TNBC patients from healthy subjects with a sensitivity (80%) and specificity (95%).

Longitudinal Tear Protein Changes Correlate with Ocular Chronic GVHD Development in Allogeneic Hematopoietic Stem Cell Transplant Patients

Ocular graft-versus-host disease (oGVHD) is a manifestation of chronic GVHD, frequently occurring in patients after allogeneic hematopoietic stem cell transplant (HSCT). We analyzed tear protein changes before and after allogeneic HSCT, and correlated their levels with the oGVHD development. This retrospective study included 102 patients, and data were recorded before the conditioning treatment, and after 3 to 6 months postoperatively. Tear protein analysis was performed with the Agilent-2100 Bioanalyzer on individual tears sampled by aspiration. Total protein (TP), Lysozyme-C (LYS-C), Lactoferrin (LACTO), Lipocalin-1 (LIPOC-1), Transferrin (TRANSF), Albumin (ALB), and Zinc-alpha-2-glycoprotein (ZAG-2) levels were retrieved and statistically analyzed. Following HSCT forty-three patients developed oGVHD. TP, LACTO, LYS-C, and ZAG-2 levels significantly decreased post-HSCT as compared to pre HSCT levels. In univariate analysis, TP, LACTO, and ZAG-2 decrease was associated with an increased development of oGVHD (OR = 4.49; 95% CI, 1.9 to 10.5; p &lt; 0.001; OR = 3.08; 95% CI 1.3 to 7.6; p = 0.01; OR = 11.1; 95% CI 2.7 to 46.6; p &lt; 0.001, respectively). TRANSF post-HSCT levels significantly increased (OR 15.7; 95% CI, 4.1 to 52.2; p = 0.0001). No pre-post-HSCT changes were shown in ALB and LIPOC-1 levels. Data suggest that TP content, LACTO, TRANSF, and ZAG-2 pre-post changes might be significant predictors of oGVHD development.

Colorimetric Diagnostic Capillary Enabled by Size Sieving in a Porous Hydrogel.

Handy and disposable point-of-care diagnostics facilitate the early screening of severe diseases in resource-limited areas. To address urgent needs in inconvenient sites, a simple colorimetric diagnostic device equipped with a capillary tube with porous hydrogel and immunocomplex particles was developed for the rapid detection of biomarkers (16 min). In this device, probe particles attach to capture particles (dp = 40 µm) and form sandwiched immunocomplexes in the presence of target biomarkers, and a red color progressively emerges when the sandwiched immunocomplex particles are blocked by the porous hydrogel embedded inside the glass capillary. Colorimetric aggregation was recorded using a smartphone and analyzed with imaging software. The limit of detection reached 1 ng/mL and showed a maximum of 79% accuracy compared with that obtained through a conventional spectrophotometric technique. The level of a diabetic retinopathy (DR) biomarker, lipocalin-1 (LCN-1), was measured in 1 µL of a human tear sample and used in testing the practicability of the proposed device. All healthy subjects showed lower intensity levels than the other diabetic counterparts (proliferative DR or nonproliferative DR patients), implying the potential of this device in clinical applications. Overall, the diagnostic device facilitates point-of-care-testing and provides a low-cost (~1 USD), compact, and reliable tool for early diagnosis in resource-limited areas.

Neutrophil gelatinase-associated lipocalin is a predictor of complications in the early phase of ST-elevation myocardial infarction.

Aim To evaluate a correlation of serum level of neutrophil gelatinase-associated lipocalin (NGAL) to the risk of the occurrence of complications in patients with the early phase of ST-segment elevation myocardical infarction (STEMI) treated with fibrinolytic therapy prior to percutaneous coronary intervention (PCI). Methods A total of 54 patients with the diagnosis of STEMI treated with fibrinolytic therapy (alteplase) prior to PCI were included. Patients were admitted to the Intensive Care Unit (ICU) of Clinic for Heart, Blood Vessel and Rheumatic Diseases in the period January to March 2018. All patients underwent coronary angiography and PCI within the maximum of 48 hours delay after fibrinolysis, according to the hemodynamic and electrical stability and PCI availability. Blood samples were taken immediately after admission prior to fibrinolytic administration. Patients were divided into two groups according to NGAL values (less or more than 134.05 ng/mL). Results Higher values of NGAL have effect on a higher mean systolic and diastolic pressure (p=0.001 and p=0.003, respectively). Patients with higher NGAL values also have higher values of brain natriuretic peptide (p=0.0001) and highly sensitive troponin I (p=0.002). In that group relative risk (RR) for lethal outcome was 6.4 times significantly higher (p=0.002), for the development of heart failure 2.88 times (p=0.0002), for post-myocardial infarction angina pectoris 2.24 times (p=0.0158), and for ventricular rhythm disturbances (ventricular tachycardia, ventricular fibrillation) 1.96 times higher (p=0.0108). Conclusion Increased NGAL value is related to an unfavourable outcome of patients in the early phase of STEMI treated with fibrinolytic therapy prior to PCI.

The Effect of Intravenous Contrast Agents on Renal Functions in Children and Adolescents in the King Abdulaziz University Hospital, Jeddah

Computerized tomography scanning is a diagnostic imaging tool that can be enhanced through the use of contrast agents. However, this process has been found to promote adverse effects, particularly those on the renal function. This study assessed the effects of intravenous iodine-based contrast agents on the kidney function in children and adolescents in the King Abdulaziz University Hospital in Jeddah, Saudi Arabia. It included 112 participants with hospital records, aged 15 years old and younger, who underwent chest or abdomen tomography scans between January 2018 and January 2019. The participants were made up of 46.4% females and 53.6% males, with a median age of 5.5 years. Majority (87.5%) of them possessed various comorbidities. This study found out that the glomerular filtration rate before and after the administration of intravenous contrast was not affected by a specific disease category, or even with no known comorbidities. However, future studies in this area should be conducted to cover more centers and regions of Saudi Arabia, but with the use of the recently identified biomarkers of AKI, such as the acute kidney injury, such as the neutrophil gelatinase-associated lipocalin and the kidney injury molecule-1, in order to match specific independent factors, such as age groups, gender, and variable comorbidities.

Associations between circulating bone-derived hormones osteocalcin, lipocalin 2, and glucose metabolism in patients with acromegaly

Objective The aim of this study was to examine the change of serum bone-derived hormones osteocalcin and lipocalin 2 (LCN2) level in patients with active acromegaly, and to further investigate the potential role of osteocalcin and LCN2 in glucose metabolism. Methods Fifty consecutive patients diagnosed as acromegaly in Nanjing Drum Tower Hospital from December 2016 to August 2018 were recruited. Of those, 41 patients after operations with complete follow-up data were also included. 30 sex, age, and body mass index matched healthy persons as normal controls. Serum osteocalcin and LCN2 levels were compared between controls and patients with acromegaly, as well as at pre- and post- operation periods. Univariate and multivariate linear regression analyses were used to investigate the correlation between bone-derived hormones and glucose metabolism indexes and to determine the independent associations between variables. Results Compared with normal controls, serum osteocalcin increased [(55.45±34.02 vs 19.46±6.69)ng/ml, P 0.05). After operation, with the decrease of serum growth hormone (GH) and insulin-like growth factor 1 (IGF-1), serum osteocalcin level decreased [24.79(18.39, 32.59) vs 43.51(26.73, 65.66)ng/ml, P<0.01] and LCN2 level increased [(45.15±15.33 vs 37.03±9.73)ng/ml, P<0.05] significantly compare to pre-operation levels. In a multivariate linear stepwise regression analysis, lean mass was shown to be the only positive predictor for LCN2 (β=0.44, P=0.015) and elevated serum IGF-1 was a positive predictor for osteocalcin (β=0.512, P<0.01). In the multivariate models, low LCN2 (β=-0.398, P=0.017) and elevated serum osteocalcin (β=0.553, P=0.001) were predictors for AUCINS, osteocalcin was a positive predictor of HOMA- β (β=0.519, P=0.004). GH (β=0.294, P=0.029) and IGF-1(β = 0.428, P=0.002) were all identified as positive predictors of HOMA-IR during multivariate testing in acromegaly patients. Conclusions Acromegaly patients had increased osteocalcin and decreased LCN2 serum levels, and corresponding alteration was detected with the correction of biochemical abnormalities. Serum osteocalcin and LCN2 were predictors of β-cell function in acromegaly patients. This study adds new evidence for the role of bone in regulating glucose metabolism in acromegaly. Key words: Acromegaly; Osteocalcin; Lipocalin 2; Glucose metabolism

Value of joint detection of NGAL, NAG, KIM-1 on early diagnosis of acute kidney injury in elderly patients

Objective To assess the value of joint detection of urinary neutrophil gelatinase-associated lipocalin(uNGAL), urinary N-Acetyl-β-D-glucosaminidase (uNAG), urinary kidney injury molecule 1(uKIM-1) for early diagnosis of acute kidney injury(AKI) in elderly patients. Methods A total of 184 elderly patients who stayed Taishan sanitarium between June 2016 and June 2018 were enrolled.According to acute kidney injury net(AKIN) work, the patients were divided into non-AKI group(68 cases)and AKI group(116 cases including 55 cases for stage 1, 39 cases for stage 2 and 24 cases for stage 3). The concentrations of urine NGAL, NAG, KIM-1 were measured.The diagnosis value of three biomarkers for AKl were analyzed with the receiver operating characteristic(ROC)curve and the area under curve(AUC). Results ①The levels of uNGAL, uNAG, uKIM-1 were higher in patients with AKI than the patients with no AKI(P<0.05). State 3 were higher than state 2 and state 1, state 2 were higher than state 1(P<0.05). ②The area under curves of uNGAL, uNAG, uKIM-1 were 0.734, 0.804 and 0.705 respectively.③The sensitivity and specificity of joint tests of three biomarkers were 84.9% and 90.7% respectively, higher than single test. Conclusions The urine NGAL, NAG and KIM-1 are sensitive indexes for the early diagnosis of elderly AKI.Joint detection has high value for early diagnosis of AKI. Key words: Acute Kidney Injury; Aged; Neutrophil gelatinase-associated lipocalin; Membrane Glycoproteins; Kidney injury molecule 1

Integrative transcriptomics and proteomic analysis of extraocular muscles from patients with thyroid-associated ophthalmopathy

Our study aimed to reveal the underlying pathologic mechanisms of thyroid-associated ophthalmopathy (TAO) by integrative transcriptomics and proteomic analysis of extraocular muscles (EOM). The study involved 11 TAO patients (clinical activity score ≤ 2) and 11 control donors. Total RNA was extracted from EOM samples of 5 TAO patients and 5 control individuals for gene microarray analysis to reveal differentially expressed genes. Concurrently, EOM samples from 3 TAO patients and 3 control individuals were lysed for quantitative proteomic analysis. Differentially expressed genes and proteins were identified, followed by functional and pathway enrichment analysis and protein-protein interaction network construction. Concordance between proteins and transcripts was examined, and functional annotations were conducted. Expressions of versican (VCAN) and lipocalin 1 (LCN1) in EOM samples from another 3 TAO patients and 3 control individuals were measured by western blotting. In total, 952 genes and 137 proteins were identified as differentially expressed, as well as 96 differentially expressed proteins without significantly changed mRNA abundance. Proteins mainly related to the composition (such as MYH1, MYH2, and MYH13) and contraction force (MYH3, MYH8, ACTN3, and TNNT1) of the muscle fibers were significantly up-regulated in EOM samples of TAO, as well as those (such as VCAN, MPZ, and PTPRC) associated with cell adhesion. In addition, differentially expressed proteins related to the components and metabolism of extracellular matrix (ECM) (such as COL1A1, COL1A2, COL2A1, VCAN, OGN, and DCN) were identified. Similarly, expressions of genes involved in cell adhesion and ECM metabolism were significantly different between EOM samples of TAO patients and controls. Western blotting verified that VCAN involved in ECM proteoglycans and diseases associated with glycosaminoglycan metabolism was markedly higher in EOM samples of TAO, whereas LCN1 was obviously decreased. In conclusion, this study demonstrated the significantly altered cellular components of EOM, muscle contraction, cell adhesion and ECM metabolism, which might be involved in the pathologic mechanisms and/or consequences of TAO.

Advances of biomarkers in acute kidney injury after non-cardiac surgery

Acute kidney injury (AKI) is a common complication after non-cardiac surgery with a variety of risk factors during perioperative period, resulting in adverse short and long-term outcomes of patients. Nowadays, early detection of injury in kidney is the first priori, development of novel biomarker making this possible. However, research in this field are mainly focused on cardiac surgery and ICU patients. In this article, it was reviewed the available literature on characteristics of promising AKI biomarkers that are currently the focus of preclinical and clinical investigations in non-cardiac surgery patients. These biomarkers include neutrophil gelatinase-associated lipocalin (NGAL), liver-type fatty acid-binding protein (L-FABP), insulin-like growth factor-binding protein 7 (IGFBP-7) and tissue inhibitor of metalloproteinase 2 (TIMP-2). It was then described the clinical performance of these biomarkers for diagnosis and prognostication of AKI. Finally, the study on biomarker guided interventional therapy for patients at high risk of postoperative AKI was reviewed. Novel biomarker will play a more important role in the diagnosis and treatment for AKI in patients after non-cardiac surgery. Key words: Non-cardiac surgery; Acute kidney injury; Biomarker; Early diagnosis; Prognosis

Sensitive tear screening of diabetic retinopathy with dual biomarkers enabled using a rapid electrokinetic patterning platform.

Bead-based immunosensors have intrigued the scientific community over the past decades due to their rapid and multiplexed capabilities in the detection of various biological targets. Nevertheless, their use in the detection of low-abundance analytes remains a continuing challenge because of their limited number of active enrichment approaches. To this end, our research presents a delicate microbead enrichment technique using an optoelectrokinetic platform, followed by the detection of dual biomarkers for the sensitive screening of an eye disease termed diabetic retinopathy (DR). In this study, microbeads turned fluorescent as their surfaces formed sandwiched immunocomplexes in the presence of target antigens. The tiny fluorescent dots were then concentrated using the optoelectrokinetic platform for the enhancement of their signals. The signal rapidly escalated in 10 s, and the optimal limit of detection was nearly 100 pg mL-1. For practical DR screening, two biomarkers, lipocalin 1 (LCN1) and vascular endothelial growth factor (VEGF), were used. Approximately 20 μL of analytes were collected from the tear samples of the tested patients. The concentrations of both biomarkers showed escalating trends with the severity of DR. Two concentration thresholds of LCN1 and VEGF that indicate proliferative DR were determined out of 24 clinical samples based on the receiver operating characteristic curves. For verification, a single-blind test was conducted with additional clinical tear samples from five random subjects. The final outcome of this evaluation showed an accuracy of >80%. This non-invasive screening provides a potential means for the early diagnosis of DR and may increase the screening rate among the high-risk diabetic population in the future.

Lipocalin-1 Expression as a Prognosticator Marker of Survival in Breast Cancer Patients

Purpose: LCN1 (lipocalin-1), a gene that encodes tear lipocalin (or von Ebner’s gland protein), is mainly expressed in secretory glands and tissues, such as the lachrymal and lingual gland, and nasal, mammary, and tracheobronchial mucosae. Analysis of the Cancer Genome Atlas (TCGA) Breast Carcinoma (BRCA) level 3 data revealed a relationship between LCN1 expression and survival in breast cancer patients. Methods: The χ² test and Fisher exact test were applied to analyze the clinical data and RNA sequencing expression data, and the association between LCN1 expression and clinicopathologic features was determined. The receiver-operating characteristic (ROC) curve of LCN1 was drawn to assess its ability as a diagnostic marker, and the optimal cutoff value was obtained from the ROC curve to distinguish groups with high and low LCN1 expression. Cox regression was used to compare both groups, and a log-rank test was applied to calculate p values and compare the ­Kaplan-Meier curves. Furthermore, GEO datasets were employed for external data validation. Results: Analysis of 1,104 breast cancer patients with a primary tumor revealed that LCN1 was overexpressed in breast cancer. High LCN1 expression was associated with clinicopathologic features and poor survival. Analyzing the area under the ROC curve (AUC) of LCN1, it was found that its diagnostic ability was limited. Multivariate analysis indicated that LCN1 expression is an independent predictor of survival in breast cancer patients. Through validation in GEO datasets, LCN1 expression was higher in tumor than normal tissue of the breast. High LCN1 expression was associated with poor survival in breast cancer patients. Conclusions: High LCN1 expression is an independent prognosticator of a poor prognosis in breast cancer.