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Background: Male sex has been identified as a risk factor for worse COVID-19 outcomes. This sex difference has been mostly attributed to the complex role of sex hormones. Cell surface entry of SARS-CoV-2 is mediated by the transmembrane protease serine 2 (TMPRSS2) which is under transcriptional regulation by androgens. P450 aromatase enzyme converts androgens to estrogens. This study measured concentrations of aromatase enzyme, testosterone, estradiol, and TMPRSS-2 in plasma of hospitalized COVID-19 patients to elucidate the dynamics of sex-linked disparity in COVID-19 and correlate them with disease severity and mortality., Methods: In this prospective cohort study, a total of 265 patients (41% women), age 18 years and older, who had a positive COVID-19 PCR test and were hospitalized for COVID-19 at Memorial Hermann Hospital in Houston, (between May 2020 and May 2021) were enrolled in the study if met inclusion criteria. Plasma concentrations of Testosterone, aromatase, TMPRSS-2, and estradiol were measured by ELISA. COVID-19 patients were dichotomized based on disease severity into moderate-severe (n = 146) or critical (n = 119). Mann Whitney U and logistic regression were used to correlate the analytes with disease severity and mortality., Results: TMPRSS2 (2.5 ± 0.31 vs. 1.73 ± 0.21 ng/mL, p < 0.01) and testosterone (1.2 ± 0.1 vs. 0.44 ± 0.12 ng/mL, p < 0.01) were significantly higher in men as compared to women with COVID-19 after adjusting for age in a multivariate model. There was no sex difference seen in the level of estradiol and aromatase in COVID-19 patients. TMPRSS2 and aromatase were higher, while testosterone was lower in patients with increased COVID-19 severity. They were independently associated with COVID-19 severity, after adjusting for several baseline risk factors in a multivariate logistic regression model. In terms of mortality, TMPRRS2 and aromatase levels were significantly higher in non-survivors., Conclusions: Our study demonstrates that testosterone, aromatase, and TMPRSS2 are markers of COVID-19 severity. Estradiol levels do not change with disease severity in COVID-19. In terms of mortality prediction, higher aromatase and TMPRSS-2 levels can be used to predict mortality from COVID-19 in hospitalized patients. COVID-19 has caused over a million deaths in the U.S., with men often getting sicker than women. Testosterone, a male hormone, helps control a protein called TMPRSS-2, which allows the COVID-19 virus to spread more easily in the body. A protein called aromatase converts the male hormone testosterone into the female hormone estrogen. It is thought that female hormone estrogen helps protect women from getting seriously ill from COVID-19. To understand the role of these hormones in COVID-19 and sex differences, we measured levels of testosterone, estrogen, aromatase (which turns testosterone into estrogen), and TMPRSS-2 in hospitalized COVID-19 patients. We also checked how this level might reflect the severity of the disease. We found that critically ill COVID-19 patients (the ones in ICU) had higher levels of TMPRSS-2 and aromatase, and lower testosterone levels. When we used these hormone levels to predict death in hospitalized COVID-19 patients, higher levels of TMPRSS-2 and aromatase were linked to a lower chance of survival., (© 2024. This is a U.S. Government work and not under copyright protection in the US; foreign copyright protection may apply.)

Background: Corin plays important roles in the regulation of blood volume and pressure and cardiac function by activating natriuretic peptide pathway, exerting multiple cardioprotective effects. But the impacts of soluble corin on clinical outcomes after ischemic stroke are unclear. We aimed to investigate the associations between serum soluble corin and long-term clinical outcomes after acute ischemic stroke., Methods and Results: We measured the concentrations of serum soluble corin in 3162 participants (2010 men and 1152 women) from the China Antihypertensive Trial in Acute Ischemic Stroke. The clinical outcomes were recurrent stroke, cardiovascular events, all-cause mortality, and unfavorable functional outcome within 24 months after stroke. Risk reclassification for study clinical outcomes of models with soluble corin were evaluated. Serum soluble corin was inversely associated with recurrent stroke, cardiovascular events, and unfavorable functional outcome after ischemic stroke. After adjusting for multiple covariates, each additional SD of log-corin was associated with a 21% (95% CI, 11-30), 16% (95% CI, 6-26), and 12% (95% CI, 3-21) decreased risk for recurrent stroke, cardiovascular events, and unfavorable functional outcome, respectively. Furthermore, the addition of soluble corin to the basic model with conventional risk factors significantly improved risk discrimination for recurrent stroke, cardiovascular events, and the composite outcome of all-cause mortality and cardiovascular events, as shown by C-statistics (all P <0.05)., Conclusions: Serum soluble corin was associated with decreased risks of long-term clinical outcomes, and may be a promising prognostic biomarker for risk stratification in patients with acute ischemic stroke.

Background: Serum corin has been associated with stroke in observational studies, but the underlying causality is uncertain. This study examined the causal association between corin and stroke through Mendelian randomization study., Methods and Results: In the Gusu cohort, serum corin was assayed at baseline, and stroke incidents were prospectively obtained during 10 years of follow-up. Single-nucleotide polymorphisms (SNPs) in CORIN were genotyped by MassArray for 2310 participants (mean age, 53 years; 39% men). Seventeen SNPs passed the Hardy-Weinberg test and were considered the potential instruments. Only 1 SNP (rs2271037) determined variability of serum corin was significantly associated with stroke even after adjusting for conventional risk factors (hazard ratio [HR], 1.36 [95% CI, 1.00-1.85]). The weighted genetic risk score generated from the SNP-corin associations was significantly associated with stroke (HR, 2.01 [95% CI, 1.15-3.51]). Using this genetic risk score as the instrument, 1-sample Mendelian randomization analysis found a significant HR of stroke per-SD higher log 2 -transformed corin (HR, 1.37 [95% CI, 1.07-1.76]). The inverse variance-weighted analysis based on the SNP-corin and SNP-stroke associations found that the HR of stroke pre-SD higher log 2 -transformed corin was 5.92 (95% CI, 2.23-15.72). The effect estimates stayed consistent regardless of an individual SNP being removed from the instruments. An almost identical effect estimate was also confirmed by multiple other 2-sample Mendelian randomization methods., Conclusions: Genetically determined variations of serum corin concentration were significantly associated with the risk of stroke in Chinese adults. Elevated serum corin may be a risk factor for stroke.

Background: Major depressive disorder (MDD) is notably underdiagnosed and undertreated due to its complex nature and subjective diagnostic methods. Biomarker identification would help provide a clearer understanding of MDD aetiology. Although machine learning (ML) has been implemented in previous studies to study the alteration of microRNA (miRNA) levels in MDD cases, clinical translation has not been feasible due to the lack of interpretability (i.e. too many miRNAs for consideration) and stability., Methods: This study applied logistic regression (LR) model to the blood miRNA expression profile to differentiate patients with MDD (n = 60) from healthy controls (HCs, n = 60). Embedded (L1-regularised logistic regression) feature selector was utilised to extract clinically relevant miRNAs, and optimized for clinical application., Results: Patients with MDD could be differentiated from HCs with the area under the receiver operating characteristic curve (AUC) of 0.81 on testing data when all available miRNAs were considered (which served as a benchmark). Our LR model selected miRNAs up to 5 (known as LR-5 model) emerged as the best model because it achieved a moderate classification ability (AUC = 0.75), relatively high interpretability (feature number = 5) and stability (ϕ̂Z=0.55) compared to the benchmark. The top-ranking miRNAs identified by our model have demonstrated associations with MDD pathways involving cytokine signalling in the immune system, the reelin signalling pathway, programmed cell death and cellular responses to stress., Conclusion: The LR-5 model, which is optimised based on ML design factors, may lead to a robust and clinically usable MDD diagnostic tool., Competing Interests: Declaration of competing interest There are no conflict of interests., (Copyright © 2024 Elsevier B.V. All rights reserved.)

Objective: Giant cell arteritis (GCA) is characterized by granulomatous inflammation of the medium- and large-sized arteries accompanied by remodeling of the vessel wall. Fibroblast activation protein alpha (FAP) is a serine protease that promotes both inflammation and fibrosis. Here, we investigated the plasma levels and vascular expression of FAP in GCA., Methods: Plasma FAP levels were measured with enzyme-linked immunosorbent assay in treatment-naive patients with GCA (n = 60) and polymyalgia rheumatica (PMR) (n = 63) compared with age- and sex-matched healthy controls (HCs) (n = 42) and during follow-up, including treatment-free remission (TFR). Inflamed temporal artery biopsies (TABs) of patients with GCA (n = 9), noninflamed TABs (n = 14), and aorta samples from GCA-related (n = 9) and atherosclerosis-related aneurysm (n = 11) were stained for FAP using immunohistochemistry. Immunofluorescence staining was performed for fibroblasts (CD90), macrophages (CD68/CD206/folate receptor beta), vascular smooth muscle cells (desmin), myofibroblasts (α-smooth muscle actin), interleukin-6 (IL-6), and matrix metalloproteinase-9 (MMP-9)., Results: Baseline plasma FAP levels were significantly lower in patients with GCA compared with patients with PMR and HCs and inversely correlated with systemic markers of inflammation and angiogenesis. FAP levels decreased even further at 3 months on remission in patients with GCA and gradually increased to the level of HCs in TFR. FAP expression was increased in inflamed TABs and aorta of patients with GCA compared with control tissues. FAP was abundantly expressed in fibroblasts and macrophages. Some of the FAP + fibroblasts expressed IL-6 and MMP-9., Conclusion: FAP expression in GCA is clearly modulated both in plasma and in vessels. FAP may be involved in the inflammatory and remodeling processes in GCA and have utility as a target for imaging and therapeutic intervention., (© 2024 The Authors. Arthritis Care & Research published by Wiley Periodicals LLC on behalf of American College of Rheumatology.)

Elevated serum corin concentrations in patients with cardiac diseases have been associated with adverse cardiovascular events and progressive renal dysfunction. This study aimed to determine the role of serum corin levels in predicting the incidence of acute kidney injury (AKI) and mortality in critically ill patients admitted to intensive care units (ICUs). We screened 323 patients admitted to the ICU in our institution from May 2018 through December 2019. After excluding patients receiving renal replacement therapy, 288 subjects were enrolled. Cases were divided equally into high (n = 144) and low (n = 144) corin groups according to median serum corin levels, using 910 pg/mL as the cut-off point. Patient characteristics and comorbidities were collected from medical records. The primary outcome was AKI within 48 h after ICU admission, while the secondary outcome was all-cause of mortality within 1 year. Compared with the low corin group, patients in the high corin group had higher prevalence rates of diabetes, cirrhosis, and nephrotoxic agent exposure; higher Sequential Organ Failure Assessment scores, white blood cell counts, proteinuria, and serum N-terminal pro-brain natriuretic peptide levels; but had lower initial estimated glomerular filtration rates. Furthermore, elevated serum corin was associated with higher risks of AKI within 48h of ICU admission (43.1% vs. 18.1%, p < 0.001) and all-cause mortality within one year (63.9% vs. 50.0%, p = 0.024). High corin level showed strongly positive results as an independent predictor of AKI (OR 2.15, 95% CI 1.11-4.19, p = 0.024) but not for the all-cause mortality after adjusting for confounding factors in multivariate analyses. Elevated circulating corin predicted AKI in critically ill patients, but did not predict all-cause mortality within 1 year. As a key enzyme in renin-angiotensin-aldosterone system, corin expression may be regulated through a feedback loop following natriuretic peptide resistance and desensitization of natriuretic peptide receptors in different critically ill status., (© 2024. The Author(s).)

Introduction: Polycystic ovary syndrome (PCOS) is a prevalent endocrine disorder. Atrial natriuretic peptide (ANP) is a risk factor for PCOS. Corin protein has an essential role in ANP synthesis. This study aimed to evaluate corin as a sensitive biomarker for PCOS., Materials and Methods: A case-control study was conducted with 70 PCOS patients and 70 healthy females. Plasma Corin levels were quantified using enzyme-linked immunosorbent assay., Results: The median plasma corin levels in PCOS patients and controls were 1785 and 822.5 pg/mL, respectively. Plasma corin levels were significantly elevated in PCOS patients than in the controls (p < 0.001). The optimal cut-off value was set at 1186 pg/mL. The sensitivity and specificity of Corin were 100% and 97.1%, respectively. Plasma corin levels were surrogate predictors for infertility in women with PCOS. It had an odds ratio of 5.9 (95% confidence interval: 1.1-32.7) (p = 0.04). Plasma corin levels were more highly detected in patients with PCOS than in the controls., Conclusion: Plasma corin level has reasonable diagnostic interpretation for PCOS. Corin appears as a worthy distinct predictor of infertility in PCOS women. Therefore, Corin may be a substantial biomarker for PCOS., (© 2024. The Author(s).)

Introduction: Tissue Fibroblast Activation Protein alpha (FAP) is overexpressed in various types of acute and chronic cardiovascular disease. A soluble form of FAP has been detected in human plasma, and low circulating FAP concentrations are associated with increased risk of death in patients with acute coronary syndrome. However, little is known about the regulation and release of FAP from fibroblasts, and whether circulating FAP concentration is associated with tissue FAP expression. This study characterizes the release of FAP in human cardiac fibroblasts (CF) and analyzes the association of circulating FAP concentrations with in vivo tissue FAP expression in patients with acute (ST-segment elevation myocardial infarction, STEMI) and chronic (severe aortic stenosis, AS) myocardial FAP expression., Methods and Results: FAP was released from CF in a time- and concentration-dependent manner. FAP concentration was higher in supernatant of TGFβ-stimulated CF, and correlated with cellular FAP concentration. Inhibition of metallo- and serine-proteases diminished FAP release in vitro. Median FAP concentrations of patients with acute (77 ng/mL) and chronic (75 ng/mL, p = 0.50 vs. STEMI) myocardial FAP expression did not correlate with myocardial nor extra-myocardial nor total FAP volume (P ≥ 0.61 in all cases) measured by whole-body FAP-targeted positron emission tomography., Conclusion: We describe a time- and concentration dependent, protease-mediated release of FAP from cardiac fibroblasts. Circulating FAP concentrations were not associated with increased in vivo tissue FAP expression determined by molecular imaging in patients with both chronic and acute myocardial FAP expression. These data suggest that circulating FAP and tissue FAP expression provide complementary, non-interchangeable information., Competing Interests: Declaration of competing interest The authors declare no conflict of interest., (Copyright © 2024 The Authors. Published by Elsevier B.V. All rights reserved.)

Two siblings presented with cardiomyopathy, hypertension, arrhythmia, and fibrosis of the left atrium. Each had a homozygous null variant in CORIN , the gene encoding atrial natriuretic peptide (ANP)-converting enzyme. A plasma sample obtained from one of the siblings had no detectable levels of corin or N-terminal pro-ANP but had elevated levels of B-type natriuretic peptide (BNP) and one of the two protein markers of fibrosis that we tested. These and other findings support the hypothesis that BNP cannot fully compensate for a lack of activation of the ANP pathway and that corin is critical to normal ANP activity, left atrial function, and cardiovascular homeostasis., (Copyright © 2023 Massachusetts Medical Society.)

Transmembrane serine protease 2 (TMPRSS2) has been intensively investigated during the current Sars‑CoV‑2 pandemic as a virus activating protease. Furthermore, TMPRSS2 is an oncogenic gene associated with several cancer entities. Co‑expression of TMPRSS2 and serpin family A member 1 ( SERPINA1 ) (encoding alpha‑1‑antitrypsin; AAT) has been reported in the human lung. Recently, AAT was identified as a novel TMPRSS2 inhibitor. We previously reported that lower SERPINA1 expression in tumor tissues and higher levels of plasma AAT are associated with worse survival of patients with non‑small cell lung cancer (NSCLC). In the present study, we sought to examine TMPRSS2 and SERPINA1/AAT expression in tumor and adjacent lung tissues from 347 NSCLC patients. Based on clinical data and gene expression analysis, we performed Cox regression for the survival analysis, and correlated TMPRSS2 and AAT protein levels in tissue samples by immunohistochemical and western blot analyses. We found that lower TMPRSS2 expression in tumor compared to adjacent non‑tumor tissues is linked to a poor overall survival in patients with adenocarcinoma (ADC) and those who are current smokers. IHC staining of TMPRSS2 validated our findings in regard to overall survival while we did not observe a correlation with AAT staining. Based on western blot analyses, we found only a slight negative correlation between full‑length TMPRSS2 and AAT in non‑tumor tissues, which seems to be related to smoking status. Taken together, we demonstrated that TMPRSS2 is a prognostic factor in patients with lung ADC; however, a link between AAT and TMPRSS2 proteins warrants further investigation.

Background: Angiotensin-converting enzyme 2 (ACE2) and transmembrane protease serine subtype 2 (TMPRSS2) are key proteins mediating viral entry of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). Although gene expressions of ACE2 and TMPRSS2 have been analyzed in various organs and diseases, their soluble forms have been less studied, particularly in asthma. Therefore, we aimed to measure circulating ACE2 and TMPRSS2 in the serum of asthmatics and examine their relationship with clinical characteristics., Methods: Clinical data and serum samples of 400 participants were obtained from an asthma cohort. The soluble ACE2 (sACE2) and soluble TMPRSS2 (sTMPRSS2) level was measured by enzyme-linked immunosorbent assay, and the values underwent a natural log transformation. Associations between sACE2 and TMPRSS2 levels and various clinical variables were analyzed., Results: The patients younger than 70 years old, those with eosinophilic asthma (eosinophils ≥ 200 cells/µL), and inhaled corticosteroids (ICS) non-users were associated with higher levels of sACE2. Blood eosinophils and fractionated exhaled nitric oxide levels were positively correlated with serum ACE2. In contrast, lower levels of sTMPRSS2 were noted in patients below 70 years and those with eosinophilic asthma, while no association was noted between ICS use and sTMPRSS2. The level of sTMPRSS2 also differed according to sex, smoking history, coexisting hypertension, and forced expiratory volume in 1 second/forced vital capacity (FEV1/FVC) ratio. The proportion of sputum neutrophils was positively correlated with sTMPRSS2, while the FEV1/FVC ratio reported a negative correlation with sTMPRSS2., Conclusion: The levels of ACE2 and TMPRSS2 were differently expressed according to age, ICS use, and several inflammatory markers. These findings suggest variable susceptibility and prognosis of SARS-CoV-2 infection among asthmatic patients., Competing Interests: The authors have no potential conflicts of interest to disclose., (© 2022 The Korean Academy of Medical Sciences.)

Cholangiocarcinoma (CCA) is a malignancy arising from cholangiocytes. Currently, the treatment and prognosis for CCA are mostly poor. Recently, we have reported that coiled-coil domain containing 25 (CCDC25) protein level in the sera may be a diagnostic marker for CCA. Subsequently, we identified three binding proteins of CCDC25 and found that kallikrein-11 (KLK11) expression was highest among those binding proteins. In this study, we investigated CCDC25 and KLK11 expression in CCA and adjacent normal tissues ( n = 18) using immunohistochemistry. The results demonstrated that the expressions of CCDC25 and KLK11 in CCA tissues were both significantly higher than the adjacent tissues ( p < 0.001 and p = 0.001, respectively). Then, using GEPIA bioinformatics analysis, KLK11 mRNA was significantly overexpressed in CCA tumor tissues compared with normal tissues ( p < 0.05). Moreover, CCDC25 expression was positively correlated with KLK11 expression in CCA with lymph node metastasis ( p = 0.028, r = 0.593). An analysis for the interaction of KLK11 with CCDC25 and other proteins, using STRING version 11.0, revealed that CCDC25 and KLK11 correlated with metastasis-related proteins. In addition, Kaplan-Meier survival curve analysis revealed that a high expression of KLK11 was associated with the poor prognosis of CCA. In conclusion, KLK11 is, as a binding protein for CCDC25, possibly involved in the metastatic process of CCA. KLK11 may be used as a prognostic marker for CCA.

Background: The recent emergence of COVID-19 poses a global health emergency. One of the most frequently reported data is sex-related severity and mortality: according to the last available analysis on 239,709 patients in Italy, lethality is 17.7% in men and 10.8% in women, with 59% of total deaths being men. Interestingly, the infection rate is lower in males than in females, with 45.8% and 54.2% of positive cases, respectively, suggesting that gender-related factor may worsen disease evolution. A tentative hypothesis to explain these findings is the role of angiotensin-converting enzyme 2 (ACE2) and serine protease TMPRSS2 involved in viral infection., Purpose: In this review, we summarize the available evidence pointing to gender-related differences in ACE2 and TMPRSS2 expression, from both genetic and endocrine points of view., Results: Altogether, available evidence points toward two not-mutually exclusive mechanisms in gender susceptibility to COVID-19 by sex hormonal regulation of ACE2 and TMPRSS2. On one hand, ACE2 expression could be increased in women, either by estrogens or constitutively by X chromosome inactivation escape or by reduced methylation, providing a larger reservoir of ACE2 to maintain the fundamental equilibrium of RAS regulatory axis. On the other, low levels of androgens in women may keep at low levels TMPRSS2 expression, representing a further protective factor for the development of COVID-19 infection, despite the increased expression of ACE2, which represents the Trojan horse for SARS-CoV-2 entry., Conclusions: Both mechanisms consistently point to the role of sex hormones and sex chromosomes in the differential severity and lethality of COVID-19 in men and women.

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has been responsible for one of the worst pandemics in modern history. Several prevention and treatment strategies have been designed and evaluated in recent months either through the repurposing of existing treatments or the development of new drugs and vaccines. In this study, we show that L-carnitine tartrate supplementation in humans and rodents led to significant decreases of key host dependency factors, notably angiotensin-converting enzyme 2 (ACE2), transmembrane protease serine 2 (TMPRSS2), and Furin, which are responsible for viral attachment, viral spike S-protein cleavage, and priming for viral fusion and entry. Interestingly, pre-treatment of Calu-3, human lung epithelial cells, with L-carnitine tartrate led to a significant and dose-dependent inhibition of the infection by SARS-CoV-2. Infection inhibition coincided with a significant decrease in ACE2 mRNA expression levels. These data suggest that L-carnitine tartrate should be tested with appropriate trials in humans for the possibility to limit SARS-CoV-2 infection.

Hypodermins A (HA), B (HB), and C (HC) of warble flies are modulatory antigens involved in host inflammation and immune responses during migration of the warble fly larvae through host connective tissues. In the current study, molecular characteristics of the genes encoding HA, HB, and HC were revealed from cDNA constructs of third-instar larvae of Hypoderma bovis. The open reading frame (ORF) of each hypodermin gene was amplified with modified gene-specific primers, and the resulting PCR products were cloned into pGEM-T Easy Vector to produce recombinant plasmids (rHA, rHB, and rHC). The ORF sequences of rHA, rHB, and rHC genes are 705 bp, 771 bp, and 783 bp long and encode proteins of 234, 256, and 263 amino acids with predicted sizes of 25.74 kDa, 27.79 kDa, and 28.51 kDa, respectively. The rHC gene was subcloned into the pET 100/D-TOPO Expression Vector, and the recombinant HC was purified using affinity chromatography. Western blotting indicated that rHC was recognized by the sera of cattle naturally infested with H. bovis. The rHC and a synthetic peptide (sHC) containing its linear B cell-specific epitope were evaluated as serological markers in indirect ELISA (iELISA) for the diagnosis of bovine hypodermosis. Both sHC and rHC iELISAs had sensitivity values equal to or higher than 90 % and specificity values of 100 %. A total of 200 serum samples from cattle in the Central Anatolia Region of Turkey were also analyzed by rHC and sHC-iELISAs to reveal the seroprevalence of bovine hypodermosis. The results of both iELISAs were consistent with one another and revealed a hypodermosis prevalence of 62 %. Our study provides the first data on molecular characterization of hypodermin genes of H. bovis and indicates the efficacy of recombinant antigen and peptide-based iELISA for serodiagnosis of bovine hypodermosis., (Copyright © 2021 Elsevier B.V. All rights reserved.)

Purpose: Reelin is an extracellular matrix protein originally found to be associated with neuropsychiatric disorders. Recent findings indicate, that reelin may also play an important role in the process of liver fibrosis as well as in the development of hepatocellular carcinoma (HCC). Against this background, the aim of our study was to explore alterations in blood reelin levels in different stages of chronic liver diseases., Patients and Methods: We analyzed blood samples of patients with chronic liver disease without liver fibrosis (n ​= ​25), with liver fibrosis (n ​= ​36), with liver cirrhosis (n ​= ​74), with HCC (n ​= ​26) as well as of healthy controls (n ​= ​15). Blood reelin concentrations were determined utilizing an enzyme-linked immunosorbent assay., Results: Blood reelin levels were significantly elevated in patients who had liver fibrosis or cirrhosis compared to patients without liver fibrosis and healthy controls (13.9 (10.2-21.1) ng/ml vs. 11.2 (8.8-16.8) ng/ml, p ​= ​0.032). Importantly, patients with HCC displayed significantly higher reelin concentrations compared to patients with liver cirrhosis alone (27.0 (17.3-35.9) ng/ml vs. 16.6 (11.0-22.7) ng/ml, p ​< ​0.001). Blood reelin was not relevantly linked to liver function, inflammation and etiology of liver disease., Conclusions: Our results demonstrate, that blood reelin levels are altered in different stages of chronic liver disease, which makes reelin a potential biomarker in this setting. This may be especially relevant with regard to its use as an additional tumor marker of HCC., Competing Interests: Declaration of competing interest The authors declare no conflict of interests., (Copyright © 2021 Medical University of Bialystok. Published by Elsevier B.V. All rights reserved.)

Introduction: Atrial natriuretic peptide (ANP) regulates water-salt balance and blood pressure by promoting renal sodium and water excretion., Objective: Our study was to investigate plasma N-terminal pro-atrial natriuretic peptide (NT-proANP) and corin in hypertensive disorders of pregnancy (HDP) patients. Furthermore, the relationship between corin/NT-proANP and neonatal adverse prognosis were evaluated., Methods: Seventy-seven HDP patients and forty-eight normotensive women as control group were recruited. Clinical characteristic and plasma were collected. Plasma NT-proANP and corin were determined by ELISA. Gestational age, neonatal weight and APGAR scores were recorded. Statistical analysis was conducted., Results: NT-proANP and corin were significantly increased in HDP group compared with that of control (P < 0.05). NT-proANP and corin were significantly elevated in HDP patients who suffered from premature delivery (P < 0.05). Both NT-proANP and corin were negatively associated with delivery time, neonatal weight and APGAR scores in HDP group. Multiple regressions demonstrated that NT-proANP and corin were independent risk factor of delivery time, neonatal weight and APGAR scores., Conclusions: Plasma NT-proANP and corin were significantly increased in HDP. NT-proANP and corin were associated with neonatal adverse events in HDP patients. Thus, NT-proANP and corin may become new biomarkers for evaluating severity of pregnancy and neonatal adverse events in HDP patients., (Copyright © 2020 The Author(s). Published by Elsevier B.V. All rights reserved.)

Genetic variants associated with iron homeostasis have been identified, but their association with iron-related indices and variables among different ethnic populations remains controversial. We aimed to explore the genotype frequency and allelic distribution of three iron-metabolism related variants in homeostatic iron regulator gene (HFE; rs1800562 G/A), transmembrane protease, Serine-6 gene (TMPRSS6; rs855791 A/G), and BTB domain-containing protein-9 gene (BTBD9; rs9357271 C/T) among a sample of the Middle Eastern blood donors and to detect the association of these variants on blood indices, and serum hepcidin/ferritin levels. Real-Time TaqMan genotyping assay for the specified variants was applied for 197 unrelated blood donors. Complete blood picture and serum hepcidin/ferritin levels were assessed. All participants were carriers of rs1800562*G/G genotype for HFE. The frequency of A/A and A/G genotypes of TMPRSS6 rs855791 variant was 55% and 45%, and for C/C, C/T, and T/T of BTBD9 rs9357271, were 15%, 43%, and 42%, respectively. Minor allele frequencies of rs855791*G and rs9357271*C were 0.23 and 0.37. The GGC genotype combination (for HFE/TMPRSS6/BTBD9, respectively) was more frequent in male participants. Higher serum hepcidin and hepcidin/ferritin ratio were observed in TMPRSS6 (A/G) carriers. While subjects with BTBD9 C/T and TT genotypes had lower serum ferritin values and higher levels of hepcidin and hepcidin/ferritin ratio compared with C/C genotype. No significant associations were found with any other blood parameters. In conclusion, TMPRSS6 rs855791 (A/G) and BTBD9 rs9357271 (C/T) variants were prevalent in the present blood donor population and may influence the serum hepcidin and/or ferritin levels., (© 2021 The Author(s).)

There is an urgent need to understand the underlying mechanisms contributing to thrombotic and inflammatory complications during COVID-19. Data from independent groups have identified that platelets are hyperreactive during COVID-19. Platelet hyperreactivity is accompanied by changes in platelet gene expression, and enhanced interactions between platelets and leukocytes. In some patients, SARS-CoV-2 mRNA has been detected in platelets. Together, this suggests that SARS-CoV-2 may interact with platelets. However, controversy remains on which receptors mediate SARS-CoV-2 platelet interactions. Most, but not all, transcriptomic and proteomic analyses fail to observe the putative SARS-CoV-2 receptor, angiotensin converting enzyme-2, or the cellular serine protease necessary for viral entry, TMPRSS2, on platelets and megakaryocytes. Interestingly, platelets express other known SARS-CoV-2 receptors, which induce similar patterns of activation to those observed when platelets are incubated with SARS-CoV-2. This article explores these findings and discusses ongoing areas of controversy and uncertainty with regard to SARS-CoV-2 platelet interactions., (© 2020 International Society on Thrombosis and Haemostasis.)

Background: The prevalence of heart failure (HF) is rising with ageing population and constitutes a major health problem globally. A common complication of HF is pulmonary hypertension (PH) which negatively impacts survival. A pathophysiological association between HF and PH with tumorigenic processes has been suggested. We aimed to identify the plasma levels of, and the association between tumour-related proteins and hemodynamic improvements in patients with HF and PH due to left heart disease (LHD) before and 1-year after heart transplantation (HT)., Methods: Forty-eight tumour-related proteins were measured with proximity extension assay in plasma from 20 controls and 26 HF patients before and 1-year after HT. Patients' hemodynamics were measured with right heart catheterization., Results: Out of 48 proteins, specifically, plasma levels of endocan and brother of CDO (BOC) were elevated in end-stage HF patients compared to controls (p < 0.001), but decreased after HT (p < 0.01), towards controls' levels. The decrease of endocan levels after HT correlated with improved mean pulmonary arterial pressure (r s  = 0.80, p < 0.0001), pulmonary arterial wedge pressure (r s  = 0.63, p = 0.0012), and pulmonary vascular resistance (r s  = 0.70, p < 0.001). The decrease and normalization of BOC after HT correlated with decreased mean right atrial pressure (r s  = 0.61 p = 0.0015) and NT-proBNP (r s  = 0.57, p = 0.0022), as well as increased cardiac index (r s  = - 0.51, p = 0.0086) and left-ventricular stroke work index (r s  = - 0.57, p = 0.0039)., Conclusion: Our results suggest that (i) plasma endocan in HF may reflect the state of pulmonary vascular congestion and PH-LHD, whereas (ii) plasma BOC may reflect the cardiac function and the hemodynamic overload in HF. The exact role of these proteins and their clinical applicability as biomarkers in HF and PH-LHD ought to be investigated in larger cohorts.

Objective: Reelin, a secreted glycoprotein, was originally identified in the central nervous system, where it plays an important role in brain development and maintenance. In the cardiovascular system, reelin plays a role in atherosclerosis by enhancing vascular inflammation and in arterial thrombosis by promoting platelet adhesion, activation, and thrombus formation via APP (amyloid precursor protein) and GP (glycoprotein) Ib. However, the role of reelin in hemostasis and arterial thrombosis is not fully understood to date. Approach and Results: In the present study, we analyzed the importance of reelin for cytoskeletal reorganization of platelets and thrombus formation in more detail. Platelets release reelin to amplify alphaIIb beta3 integrin outside-in signaling by promoting platelet adhesion, cytoskeletal reorganization, and clot retraction via activation of Rho GTPases RAC1 (Ras-related C3 botulinum toxin substrate) and RhoA (Ras homolog family member A). Reelin interacts with the collagen receptor GP (glycoprotein) VI with subnanomolar affinity, induces tyrosine phosphorylation in a GPVI-dependent manner, and supports platelet binding to collagen and GPVI-dependent RAC1 activation, PLC gamma 2 (1-phosphatidylinositol-4,5-bisphosphate phosphodiesterase gamma-2) phosphorylation, platelet activation, and aggregation. When GPVI was deleted from the platelet surface by antibody treatment in reelin-deficient mice, thrombus formation was completely abolished after injury of the carotid artery while being only reduced in either GPVI-depleted or reelin-deficient mice., Conclusions: Our study identified a novel signaling pathway that involves reelin-induced GPVI activation and alphaIIb beta3 integrin outside-in signaling in platelets. Loss of both, GPVI and reelin, completely prevents stable arterial thrombus formation in vivo suggesting that inhibiting reelin-platelet-interaction might represent a novel strategy to avoid arterial thrombosis in cardiovascular disease.

Introduction: In cancer treatment an attempt has been made to pharmacologically regulate the proteasome functions, thus the aim was to test whether 20S proteasome chymotrypsin-like (ChT-L) activity has a role in glial brain tumors. Furthermore, we analyzed the correlation between proteasome activity and IL-8, CCL2, NF-κB1 and NF-κB2 concentrations, which impact on brain tumors has already been indicated., Methods: Plasma 20S proteasome ChT-L activity was assayed using the fluorogenic peptide substrate Suc-Leu-Leu-Val-Tyr-AMC in the presence of SDS. IL-8, CCL2, NF-κB1 and NF-κB2 concentration was analyzed with the use of ELISA method. Immunohistochemistry for IDH1-R132H was done on 5-microns-thick formalin-fixed, paraffin-embedded tumor sections with the use of antibody specific for the mutant IDH1-R132H protein. Labelled streptavidin biotin kit was used as a detection system., Results: Brain tumor patients had statistically higher 20S proteasome ChT-L activity (0.649 U/mg) compared to non-tumoral individuals (0.430 U/mg). IDH1 wild-type patients had statistically higher 20S proteasome ChT-L activity (1.025 U/mg) compared to IDH1 mutants (0.549 U/mg). 20S proteasome ChT-L activity in brain tumor patients who died as the consequence of a tumor (0.649) in the following 2 years was statistically higher compared to brain tumor patients who lived (0.430 U/mg). In brain tumor patients the 20S proteasome ChT-L activity positively correlated with IL-8 concentration., Conclusions: Elevated 20S proteasome ChT-L activity was related to the increased risk of death in glial brain tumor patients. A positive correlation between 20S proteasome ChT-L activity and IL-8 concentration may indicate the molecular mechanisms regulating glial tumor biology. Thus research on proteasomes may be important and should be carried out to verify if this protein complexes may represent a potential therapeutic target to limit brain tumor invasion., Competing Interests: The authors have declared that no competing interests exist.

Objectives: We aimed to identify serum level variations in protein-derived peptides between patients diagnosed with gastric adenocarcinoma (GAC) and non-cancer persons (control) to detect the activity changes of proteases and explore the auxiliary diagnostic value in the context of GAC physiopathology., Methods: The label-free quantitative peptidome approach was applied to identify variants in serum levels of peptides that can differentiate GAC patients from the control group. Peptide sequences were submitted against Proteasix tool predicting proteases potentially involved in their generation. The activity change of proteases was subsequently estimated based on the peptides with significantly altered relative abundance. In turn, activity change prediction of proteases was correlated with relevant protease expression data from the literature., Results: A total of 191 peptide sequences generated by the cleavage of 36 precursor proteins were identified. Using the label-free quantification approach, 33 peptides were differentially quantified (adjusted fold change ≥ 1.5 and p-value < 0.05) in which 19 were up-regulated and 14 were down-regulated in GAC samples. Of these peptides, fibrinopeptide A was significantly decreased and its phosphorylated form ADpSGEGDFLAEGGGVR was upregulated in GAC samples. Activity change prediction yielded 10 proteases including 6 Matrix Metalloproteinases (MMPs), Thrombin, Plasmin, and kallikreins 4 and 14. Among predicted proteases in our analysis, MMP-7 was presented as a more promising biomarker associated with useful assays of clinical practice for GAC diagnosis., Conclusion: Our experimental results demonstrate that the serum levels of peptides were significantly differentiated in GAC physiopathology. The hypotheses built on protease regulation could be used for further investigations to measure proteases and their activity levels that have been poorly studied for GAC diagnosis., Competing Interests: Declaration of Competing Interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2020 The Canadian Society of Clinical Chemists. Published by Elsevier Inc. All rights reserved.)

The proline-specific enzymes dipeptidyl peptidase 4 (DPP4), prolylcarboxypeptidase (PRCP), fibroblast activation protein α (FAP) and prolyl oligopeptidase (PREP) are known for their involvement in the immune system and blood pressure regulation. Only very limited information is currently available on their enzymatic activity and possible involvement in patients with sepsis and septic-shock. The activity of the enzymes was measured in EDTA-plasma of patients admitted to the intensive care unit (ICU): 40 septic shock patients (sepsis-2) and 22 ICU control patients after major intracranial surgery. These data were used to generate receiver operating characteristic (ROC) curves. A survival analysis (at 90 days) and an association study with other parameters was performed. PRCP (day 1) and PREP (all days) enzymatic activities were higher in septic shock patients compared to controls. In contrast, FAP and DPP4 were lower in these patients on all studied time points. Since large differences were found, ROC curves were generated and these yielded area under the curve (AUC) values for PREP, FAP and DPP4 of 0.88 (CI: 0.80-0.96), 0.94 (CI: 0.89-0.99) and 0.86 (CI: 0.77-0.95), respectively. PRCP had a lower predicting value with an AUC of 0.71 (CI: 0.58-0.83). A nominally significant association was observed between survival and the DPP4 enzymatic activity at day 1 (p<0.05), with a higher DPP4 activity being associated with an increase in survival. All four enzymes were dysregulated in septic shock patients. DPP4, FAP and PREP are good in discriminating between septic shock patients and ICU controls and should be further explored to see whether they are already dysregulated in earlier stages, opening perspectives for their further investigation as biomarkers in sepsis. DPP4 also shows potential as a prognostic biomarker. Additionally, the associations found warrant further research., Competing Interests: The authors have declared that no competing interests exist.

Fibroblast growth factor 21 (FGF21) is an important regulator of energy metabolism. FGF21 is inactivated by fibroblast activation protein (FAP). We investigated whether FGF21 and/or FAP are secreted from human white adipose tissue of individuals with obesity by measuring total FGF21, active FGF21, and FAP concentrations in arterialized blood and venous blood draining the subcutaneous abdominal adipose tissue (scAT). Measurements were performed under fasting conditions and after a high fat meal before and after diet-induced weight loss in 16 adults with BMI 27-35 kg/m 2 . FGF21 was not released from scAT, neither before nor after weight loss in agreement with an undetectable gene expression of FGF21 in this tissue. Although scAT showed significant gene expression of FAP, no release of FAP from the tissue could be detected. The high fat meal increased postprandial circulating FGF21 but not FAP. Circulating levels of FAP but not FGF21 were significantly reduced after weight loss. On the other hand, FAP expression in scAT was increased. In conclusion, release from scAT does not appear to contribute to circulating concentrations of FGF21 and FAP and their responses to ingestion of a high fat meal or weight loss, respectively, in individuals with obesity.

Objective: Development of biomarkers for Charcot-Marie-Tooth (CMT) disease is critical for implementing effective clinical trials. The most common form of CMT, type 1A, is caused by a genomic duplication surrounding the PMP22 gene. A recent report (Neurology 2018;90:e518-3524) showed elevation of neurofilament light (NfL) in plasma of CMT1A disease patients, which correlated with disease severity. However, no plasma/serum biomarker has been identified that is specific to Schwann cells, the most directly affected cells in CMT1A., Methods: We used the Olink immuno PCR platform to profile CMT1A patient (n = 47, 2 cohorts) and normal control plasma (n = 41, two cohorts) on five different Olink panels to screen 398 unique proteins., Results: The TMPRSS5 protein (Transmembrane protease serine 5) was elevated 2.07-fold (P = <0.0001) in two independent cohorts of CMT1A samples relative to controls. TMPRSS5 is most highly expressed in Schwann cells of peripheral nerve. Consistent with early myelination deficits in CMT1A, TMPRSS5 was not significantly correlated with disease score (CMTES-R, CMTNS-R), nerve conduction velocities (Ulnar CMAP, Ulnar MNCV), or with age. TMPRSS5 was not significantly elevated in smaller sample sets from patients with CMT2A, CMT2E, CMT1B, or CMT1X. The Olink immuno PCR assays confirmed elevated levels of NfL (average 1.58-fold, P < 0.0001), which correlated with CMT1A patient disease score., Interpretation: These data identify the first Schwann cell-specific protein that is elevated in plasma of CMT1A patients, and may provide a disease marker and a potentially treatment-responsive biomarker with good disease specificity for clinical trials., (© 2019 The Authors. Annals of Clinical and Translational Neurology published by Wiley Periodicals, Inc on behalf of American Neurological Association.)

Background: Corin is an important convertase involved in the natriuretic peptide system and may indirectly regulate blood pressure. Genetic factors relate to corin remain unclear. The purpose of the current study was to comprehensively examine the associations among CORIN SNPs, methylations, serum corin levels and hypertension., Results: We genotyped 9 tag-SNPs in the CORIN gene and measured serum corin levels in 731 new-onset hypertensive cases and 731 age- and sex-matched controls. DNA methylations were tested in 43 individuals. Mendelian randomization was used to investigate the causal associations. Under additive models, we observed associations of rs2289433 (p.Cys13Tyr), rs6823184, rs10517195, rs2271037 and rs12509275 with serum corin levels after adjustment for covariates (P = 0.0399, 0.0238, 0.0016, 0.0148 and 0.0038, respectively). The tag-SNP rs6823184 and SNPs that are in strong linkage disequilibrium with it, i.e., rs10049713, rs6823698 and rs1866689, were associated with CORIN gene expression (P = 2.38 × 10 - 24 , 5.94 × 10 - 27 , 6.31 × 10 - 27 and 6.30 × 10 - 27 , respectively). Neither SNPs nor corin levels was found to be associated with hypertension. SNP rs6823184, which is located in a DNase hypersensitivity cluster, a CpG island and transcription factor binding sites, was significantly associated with cg02955940 methylation levels (P = 1.54 × 10 - 7 ). A putative causal association between cg02955940 methylation and corin levels was detected (P = 0.0011)., Conclusion: This study identified potentially functional CORIN SNPs that were associated with serum corin level in the Chinese Han population. The effect of CORIN SNPs on corin level may be mediated by DNA methylation.

Introduction: Proprotein convertase subtilisin/kexin-6 (PCSK6) is a secretory protein that activates corin in the heart. Higher circulating levels of corin are associated with improved cardiovascular outcomes in patients with acute myocardial infarction. This study aimed to determine the role of serum PCSK6 and corin levels in predicting cardiovascular outcomes in patients with suspected coronary artery disease (CAD)., Materials and Methods: In total, 565 patients who had undergone coronary angiography were enrolled. Serum PCSK6 and corin levels were determined before the administration of contrast media. In this study, coronary revascularization, acute myocardial infarction, acute stroke, and death were defined as cardiovascular outcomes. All patients were followed up for at least one year after coronary angiography or until the occurrence of death., Results: During a median follow-up of 691 days, 67 patients (15.7%) developed composite cardiovascular outcomes after coronary angiography, including 51 incidents of coronary revascularization, 7 instances of acute myocardial infarction, 2 acute strokes, and 15 deaths. After adjustment for demographic characteristics and all significant variables in the univariate analysis, serum levels of neither PCSK6 nor corin were associated with increased risk for cardiovascular outcomes. This correlation remained insignificant in patients with underlying hypertension, diabetes mellitus, CAD, heart failure, or chronic kidney disease (CKD). However, in patients without CKD, higher serum PCSK6 levels were associated with increased risk for cardiovascular outcomes (hazard ratio 1.380; 95% confidence interval 1.023-1.862)., Conclusions: We found no association between cardiovascular outcomes and pre-procedural serum levels of PCSK6 or corin in patients undergoing coronary angiography. However, an increased risk was seen in non-CKD patients with higher PCSK6 levels. Further studies are needed to verify these results., Competing Interests: The authors have declared that no competing interests exist.

The zymogen form of circulating Factor VII activating protease (FSAP) is activated by histones that are released as a consequence of tissue damage or excessive inflammation. This is likely to have consequences in a number of disease conditions such as stroke, atherosclerosis, liver fibrosis, thrombosis and cancer. To investigate the existence, as well as the concentration of active FSAP (FSAPa) in complex biological systems an active site probe is needed. We used Hybrid Combinatorial Substrate Library (HyCoSuL) to screen for natural and unnatural amino acids that specifically bind to P4-P2 pockets of FSAPa. This information was used to designing a fluorogenic substrate (Ac-Pro-DTyr-Lys-Arg-ACC) as well as an irreversible, fluorogenic activity-based probe Cy5-6-Ahx-Pro-DTyr-Lys-Arg P (OPh) 2 . In normal human plasma the probe showed very low non-specific reactivity with some plasma proteins but upon activation of pro-FSAP with histones, strong labelling of FSAPa was observed. This labelling could be inhibited by aprotinin and was not found in the plasma of a subject that was homozygous for a polymorphism, which leads to loss of activity, or in plasma that was depleted of FSAP by antibodies. This 2nd generation substrate exhibited 6-fold higher catalytic efficiency than the 1st generation substrate and a much higher selectivity for FSAPa over other plasma proteases. This substrate and probe can be useful to detect and localize FSAPa in normal and pathological tissue and plasma to gain more insight into its functions., (Copyright © 2019 Elsevier Ltd. All rights reserved.)

Purpose: Fibroblast growth factor (FGF) 21 is a circulating hormone with an important role in metabolic regulation. FGF21 production in humans responds positively to glucose consumption and we hypothesize that serum FGF21 concentration is associated to glycemic control., Methods: We enrolled 31 patients with type 1 diabetes (T1D) based on their HbA1c (well-regulated (HbA1c <53 mmol/mol), (n = 18) or poorly-regulated (HbA1c >69 mmol/mol), (n = 13). Twelve patients (39%) were diagnosed with retinopathy. Twenty healthy individuals comparable for age and gender distribution were included as a reference group. Serum FGF21, intact FGF21, fibroblast activation protein (FAP), adiponectin, and C-Reactive Protein (CRP) were measured by immunoassays., Results: No correlation between FGF21 concentration and HbA1c was found. Patients with T1D had lower levels of circulating FGF21 as compared with the reference group, but the difference was nonsignificant (p = 0.12). Dividing the patients according to retinopathy, we found that T1D patients with retinopathy had significantly lower FGF21 concentrations (10.0 ng/L) as compared with the healthy reference group (37.1 ng/L), (p = 0.02). We found significantly higher levels of the FGF21 cleaving enzyme, FAP, in patients with T1D (97.2 μg/L) as compared with the healthy control group (78.5 μg/L), (p = 0.006). Interestingly, serum FAP levels correlated significantly with circulating FGF21 levels in T1D patients, but this correlation was not found in the healthy controls., Conclusions: We found no association between circulating FGF21 levels and HbA1c. T1D patients with retinopathy had significantly lower FGF21 levels as compared with healthy individuals, but it remains unclear if the lower levels of FGF21 are pathogenically related to the development of microvascular complications. Of note, serum FAP levels were significantly higher in all T1D patients as compared with the healthy individuals.

Background: Fibroblast activiation protein alpha (FAP) is considered a diagnostic and prognostic biomarker for various types of cancer. FAP shares substrate specificity with prolyl oligopeptidase (PREP), studied in (neuro)inflammation and neurodegeneration as well as cancer. Current assays inadequately discriminate between FAP and PREP and there is need for an assay that reliably quantitates the FAP/PREP activity ratio in plasma., Methods: FAP and PREP activities were measured in human EDTA-plasma in presence of well characterized PREP and FAP inhibitors., Results: A combined kinetic assay was developed in conditions to optimally measure FAP as well as PREP activity with Z-Gly-Pro-AMC as substrate. Limit of detection was 0.009 U/L and limit of quantitation was 0.027 U/L for the combined FAP-PREP assay. Within-run coefficient of variation was 3% and 4% and between-run precision was 7% and 12% for PREP and FAP, respectively. Accuracy was demonstrated by comparison with established end-point assays. Hemolysis interferes with the assay with 1.5 g/L hemoglobin as cut-off value. PREP (but not FAP) activity can increase upon lysis of platelets and red blood cells during sample preparation., Conclusion: With this new assay, on average 67% of the Z-Gly-Pro-AMC converting activity in plasma can be attributed to FAP., (Copyright © 2019 Elsevier B.V. All rights reserved.)

Soluble corin has been associated with cardiovascular disease and its risk factors, but whether it is associated with metabolic syndrome (MetS), a cluster of cardiometabolic disorders, remains unclear. We aimed to examine the association between soluble corin and MetS in Chinese men and women. We examined serum soluble corin using immunoassays in 962 men (mean age, 53 years) and 1536 women (mean age, 54 years) free of cardiovascular disease. Logistic regression was applied to examine the association between soluble corin and MetS in men and women. The results showed that participants in the 3rd and 4th quartiles of serum soluble corin had 1.99 (95% CI: 1.32-3.00) and 3.84 (95% CI: 2.54-5.83) times the risk of having MetS for men and 1.48 (95% CI: 1.06-2.06) and 1.53 (95% CI: 1.10-2.12) times the risk of having MetS for women compared to those in the lowest quartile. The magnitude of the association between serum soluble corin and MetS was significantly stronger for men than for women (P < 0.001). These results indicated that soluble corin was significantly associated with MetS, and this association was stronger for men than for women. Corin may contribute to cardiometabolic risks differently between men and women and thereby accounting, at least partly, for the sex difference in cardiovascular risk.

Objective: Fibroblast growth factor (FGF)21 is promptly induced by short fasting in animal models to regulate glucose and fat metabolism. Data on FGF21 in humans are inconsistent and FGF21 has not yet been investigated in old patients with cachexia, a complex syndrome characterized by inflammation and weight loss. The aim of this study was to explore the association of FGF21 with cachexia in old patients compared with their healthy counterparts., Methods: Serum FGF21 and its inactivating enzyme fibroblast activation protein (FAP)-α were measured with enzyme-linked immunoassays. Cachexia was defined as ≥5% weight loss in the previous 3 mo and concurrent anorexia (Council on Nutrition appetite questionnaire)., Results: We included 103 patients with and without cachexia (76.9 ± 5.2 y of age) and 56 healthy controls (72.9 ± 5.9 y of age). Cachexia was present in 16.5% of patients. These patients had significantly higher total FGF21 levels than controls (952.1 ± 821.3 versus 525.2 ± 560.3 pg/mL; P = 0.012) and the lowest FGF21 levels (293.3 ± 150.9 pg/mL) were found in the control group (global P < 0.001). Although FAP-α did not differ between the three groups (global P = 0.082), bioactive FGF21 was significantly higher in patients with cachexia (global P = 0.002). Risk factor-adjusted regression analyses revealed a significant association between cachexia and total (β = 649.745 pg/mL; P < 0.001) and bioactive FGF21 (β = 393.200 pg/mL; P <0.001), independent of sex, age, and body mass index., Conclusions: Patients with cachexia exhibited the highest FGF21 levels. Clarification is needed to determine whether this is an adaptive response to nutrient deprivation in disease-related cachexia or whether the increased FGF21 values contribute to the catabolic state., (Copyright © 2018 Elsevier Inc. All rights reserved.)

Background: Corin is a serine protease known to convert B-type natriuretic peptide (BNP) prohormone into BNP and its amino-terminal fragment (NT-proBNP). In mice lacking corin, high blood pressure and proteinuria were found at late gestational stages, with associated delayed trophoblast invasion and impaired spiral artery remodeling in the uterus. We hypothesize that both NT-proBNP and soluble corin elevation predict the presence of preeclampsia in pregnant patients with hypertension., Methods: We prospectively enrolled 149 pregnant women with a history of chronic hypertension or gestational hypertension presenting at a tertiary-care hospital. We compared plasma NT-proBNP and soluble corin concentrations based on their preeclamptic status., Results: In our study cohort, 62 patients with preeclampsia had lower gestational age than 87 patients without preeclampsia (33.3 ± 3 versus 36.6 ± 3 weeks; P < .001), otherwise the baseline characteristics were similar. We observed higher NT-proBNP concentrations in patients with preeclampsia compared to those without preeclampsia (304.3 [96.34, 570.4] vs. 60.8 [35.61, 136.8] ng/L, P < .001), with no differences between chronic and gestational hypertension. However, the concentration of corin was not statistically different between the two groups (1756 [1214, 2133] vs. 1571 [1171, 1961] ng/L, P = .1087). ROC curve analysis demonstrated stronger predictive value of NT-proBNP compared to soluble corin in predicting the presence of preeclampsia in our study population (AUC 0.7406 vs. 0.5789, P < .0001)., Conclusion: While corin may contribute to mechanistic underpinnings of the development of preeclampsia in animal models, soluble corin likely has no diagnostic role in human pregnancies for preeclampsia beyond natriuretic peptide levels., (Copyright © 2019 The Canadian Society of Clinical Chemists. Published by Elsevier Inc. All rights reserved.)

Background: Dengue virus (DENV), a common and widely spread arbovirus, causes life-threatening diseases, such as dengue hemorrhagic fever or dengue shock syndrome. There is currently no effective therapeutic or preventive treatment for DENV infection., Methods: Next-generation sequencing analysis revealed that prostasin expression was decreased upon DENV infection. Prostasin expression levels were confirmed by real-time quantitative polymerase chain reaction in patients with dengue fever and a DENV-infected mice model. Short hairpin RNA against EGFR and LY294002 were used to investigate the molecular mechanism., Results: Based on clinical studies, we first found relatively low expression of prostasin, a glycosylphosphatidyl inositol-anchored membrane protease, in blood samples from patients with dengue fever compared with healthy individuals and a high correlation of prostasin expression and DENV-2 RNA copy number. DENV infection significantly decreased prostasin RNA levels of in vivo and in vitro models. By contrast, exogenous expression of prostasin could protect ICR suckling mice from life-threatening DENV-2 infection. Mechanistic studies showed that inhibition of DENV propagation by prostasin was due to reducing expression of epithelial growth factor receptor, leading to suppression of the Akt/NF-κB-mediated cyclooxygenase-2 signaling pathway., Conclusion: Our results demonstrate that prostasin expression is a noteworthy clinical feature and a potential therapeutic target against DENV infection., (© The Author(s) 2018. Published by Oxford University Press for the Infectious Diseases Society of America. All rights reserved. For permissions, e-mail: journals.permissions@oup.com.)

Purpose: There are currently no biomarkers that are associated with cognitive impairment (CI) in patients with obstructive sleep apnea syndrome (OSAS). This pilot study performed an exploratory plasma proteomic analysis to discover potential biomarkers and explore proteomic pathways that differentiate OSAS subjects with and without CI., Methods: Participants were selected from a cohort of women within 5 years of menopause not on hormone replacement therapy between the ages of 45-60 years. The Berlin questionnaire was used to select OSAS participants who then completed the MCFSI (Mail-In Cognitive Function Screening Instrument) to measure cognition. Six subjects with the highest MCFSI scores (≥ 5 denoting CI) were compared to six with normal scores. Proteomic analysis was done by Myriad RBM using a targeted ELISA for 254 serum proteins. Pathway analysis of differentially expressed proteins was performed using STRING (Search Tool for the Retrieval of Interacting Genes/Proteins) software., Results: Distinct proteomic signatures were seen in OSAS subjects with CI as compared to those without CI. Proteins including insulin, prostasin, angiopoietin-1, plasminogen activator inhibitor 1, and interleukin-1 beta were overexpressed in OSAS subjects with CI. Proteins underexpressed in CI participants included cathepsin B, ceruloplasmin, and adiponectin. Pathway analysis revealed prominence of insulin-regulated vascular disease biomarkers., Conclusions: Proteomic biomarkers in participants with cognitive impairment suggest roles for insulin, and vascular signaling pathways, some of which are similar to findings in Alzheimer's disease. A better understanding of the pathogenic mechanisms of CI in OSAS will help focus clinical trials needed in this patient population.

Background: Stress precipitates mood disorders, characterized by a range of symptoms present in different combinations, suggesting the existence of disease subtypes. Using an animal model, we previously described that repetitive stress via restraint or immobilization induced depressive-like behaviors in rats that were differentially reverted by a serotonin- or noradrenaline-based antidepressant drug, indicating that different neurobiological mechanisms may be involved. The forebrain astrocyte protein aldolase C, contained in small extracellular vesicles, was identified as a potential biomarker in the cerebrospinal fluid; however, its specific origin remains unknown. Here, we propose to investigate whether serum small extracellular vesicles contain a stress-specific protein cargo and whether serum aldolase C has a brain origin., Methods: We isolated and characterized serum small extracellular vesicles from rats exposed to restraint, immobilization, or no stress, and their proteomes were identified by mass spectrometry. Data available via ProteomeXchange with identifier PXD009085 were validated, in part, by western blot. In utero electroporation was performed to study the direct transfer of recombinant aldolase C-GFP from brain cells to blood small extracellular vesicles., Results: A differential proteome was identified among the experimental groups, including aldolase C, astrocytic glial fibrillary acidic protein, synaptophysin, and reelin. Additionally, we observed that, when expressed in the brain, aldolase C tagged with green fluorescent protein could be recovered in serum small extracellular vesicles., Conclusion: The protein cargo of serum small extracellular vesicles constitutes a valuable source of biomarkers of stress-induced diseases, including those characterized by depressive-like behaviors. Brain-to-periphery signaling mediated by a differential molecular cargo of small extracellular vesicles is a novel and challenging mechanism by which the brain might communicate health and disease states to the rest of the body., (© The Author(s) 2018. Published by Oxford University Press on behalf of CINP.)

Corin (an atrial natriuretic peptide-converting enzyme) represents a potential biomarker for gestational hypertensive disorders; yet, its role in blood pressure (BP) regulation throughout pregnancy remains unclear. We investigated the time course of change in blood corin content in relation to BP and sympathetic nerve activity throughout pregnancy. Forty-four women (29±0.9 years) participated. Following-term, 23 had low-risk (no personal history of gestational hypertensive disorders) normal pregnancies, 13 had high-risk (personal history of gestational hypertensive disorders) normal pregnancies, and 8 developed gestational hypertension. BP, heart rate, muscle sympathetic nerve activity, and serum corin were measured before pregnancy, during early (4-8 weeks) and late pregnancy (32-36 weeks), and postpartum (6-10 weeks). Overall, compared with prepregnancy, corin remained unchanged during early pregnancy, increased markedly during late pregnancy ( P<0.001), and returned to prepregnancy levels postpartum. In women who developed gestational hypertension, the change in corin from early to late pregnancy was greater than those with low-risk normal pregnancies (Δ971±134 versus Δ486±79 pg/mL; P<0.05). Throughout pregnancy, BP and muscle sympathetic nerve activity were augmented in women with gestational hypertension (all P<0.05). Finally, changes in corin from early to late pregnancy were related to all indices of BP ( R=0.454-0.551; all P<0.01) in late pregnancy, whereas burst frequency, burst incidence, and total muscle sympathetic nerve activity ( R=0.576-0.614; all P<0.001) in early pregnancy were related to changes in corin from early to late pregnancy. Corin plays a unique role in BP regulation throughout normotensive and, especially, hypertensive pregnancy and may represent a promising biomarker for determining women at high risk of adverse pregnancy outcome.

Renal ischemia/reperfusion (IR) injury is one of the most important risk factors for the occurrence of delayed graft function (DGF) after kidney transplantation; however, its mechanism remains not fully understood. In the present study, we screened differentially expressed genes in a murine model of renal IR injury by using high-throughput assays. We identified Corin as one of the most significantly downregulated genes among 2218 differentially expressed genes (≥2-fold, P < 0.05). By using a real-time qPCR assay, we observed that the expression of renal Corin in IR-injured mice was reduced to 11.5% of the sham-operated mice and that the protein level of renal Corin in IR-injured mice was also downregulated. Interestingly, renal IR injury in mice induced the downregulation of Corin in heart tissues, suggesting that the overall synthesis of Corin may be suppressed. We recruited 11 recipients complicated with DGF and 16 without DGF, and plasma Corin concentrations were determined by ELISA. We observed that the plasma Corin levels were indeed reduced in recipients complicated with DGF (0.98 vs. 1.95 ng/ml, P < 0.05). These findings demonstrate that Corin may be a potential biomarker of DGF after kidney transplantation and may participate in the regulation of renal IR injury.

Objective: The aim of this study was to investigate the potential utility of serum HtrA1 and HtrA3, serine proteases that are highly expressed in the developing placenta, at 15 and 20 weeks of gestation for predicting later development of adverse pregnancy outcomes of preeclampsia (PE), gestational hypertension (GHT), preterm birth (PTB), and small for gestational age (SGA) birth., Methods: This is a nested case control study of 665 samples (330 controls, 335 cases) from the Adelaide SCOPE cohort. The cases included were 92 PE, 71 GHT, 56 PTB, and 116 SGA. Samples were assessed by ELISA and data adjusted for maternal age, BMI, socioeconomic index, hCG, and smoking status. Multivariate logistic regression was performed with other biochemical and biophysical parameters available for these samples., Results: HtrA1 did not differ between the controls and cases. In contrast, HtrA3 was significantly lower at 15 weeks in pregnancies that later developed late-onset PE (LPE) or resulted in SGA birth, with an area under the ROC curve (AUC) of 0.716 and 0.790, respectively. The combination of HtrA3 with PAPP-A, uterine, and umbilical Doppler improved the AUC to 0.755 for LPE and 0.844 for SGA., Conclusion: HtrA3 at 15 weeks is associated with, and may be useful for, the early detection of LPE development and SGA birth., (© 2019 S. Karger AG, Basel.)

Preeclampsia is a serious disorder of human pregnancy occurring after 20 weeks of gestation. It can be divided into subtypes of early onset (<34 weeks of gestation) and late onset (>34 weeks). Presymptomatic detection to identify those at high risk is important for managing this disease. HtrA3, a serine protease with high expression in the developing placenta, exists in long (HtrA3-L) and short (HtrA3-S) isoforms. They are identical, except HtrA3-S lacks the C-terminal PDZ domain. We have previously shown by Western blot analysis that serum HtrA3 levels at the end of the first trimester are significantly higher in women who later develop preeclampsia than in controls. In this study, using highly specific HtrA3 monoclonal antibodies, we established and fully validated two enzyme-linked immunosorbent assays to detect both HtrA3 isoforms together (HtrA3-T) and HtrA3-L alone in the human serum. We then determined serum HtrA3 at 11 to 13 weeks of gestation in a cohort of singleton pregnancies that proceeded without complications or developed preeclampsia in the third trimester. Compared with controls, those who developed late-onset preeclampsia had significantly higher levels of HtrA3-L, whereas those who developed early-onset preeclampsia had significantly lower ratios of HtrA3-L/HtrA3-T. These data support a potential utility of these HtrA3 ELISAs for early detection of preeclampsia.

Background: Pre-eclampsia (PE) affects 2% to 5% of all pregnancies and is a major cause of maternal and perinatal morbidity and mortality worldwide. Since PE has complex pathogenesis and treatment is still not found, effective methods for prediction and prevention of PE are still actively searched., Aim: The aim of this study was to find the mean maternal serum concentration of four proteins in Bulgarian pregnant women and to investigate the correlation with uterine artery pulsatility index in the first and second trimester of pregnancy., Materials and Methods: In this prospective case-control study, maternal serum concentrations of corin, sEndoglin, PP13, and sFlt-1 were measured, pulsatility index of uterine artery (PI-UA) was assessed in 40 women with Doppler, twice during pregnancy - at the 11th - 13th weeks of gestation and the 20th gestational week. They were randomized in two groups: an experimental group: with increased PIUA at gestational week 13 and a control group: with normal PI-UA. All pregnancies were followed up until the day of delivery and outcomes were recorded., Results: There was no significant difference in the APGAR score and birth weight of the newborns between groups. We found no significant difference in the mean concentration of sEnd, sFlt-1 and PP13 between 11-13 weeks of gestation and 20 week of gestation in the control and experimental groups. Statistically significant difference was found only in the mean concentrations of corin between weeks 11-13 and week 20 in both control (t=3.27; p=0.004) and experimental group (t=3.22; p=0.005). Corin levels and the mean PI of uterine arteries tended to decrease with progression of pregnancy in both groups., Conclusions: Further prospective studies of larger populations are required to develop a panel of multiple predictors for PE.

Background: Idiopathic pulmonary fibrosis (IPF) is a fatal lung disease with 3 to 5 years' survival. Although FVC is used to assess disease progression and treatment response, identifying predictive circulating blood biomarkers could help identify specific biologic pathways for treatment. An international, prospective, noninterventional, case-controlled, 52-week study was therefore conducted to identify a clinical and biomarker baseline profile predictive of longitudinal disease behavior., Methods: Patients with IPF and control subjects had lung function tests and blood sampling for biomarker quantification (control subjects at baseline only). The primary end point was disease progression rate (composite end point: decrease ≥ 10% from baseline in FVC % predicted, decrease ≥ 15% from baseline in diffusing capacity of the lung for carbon monoxide % predicted, lung transplantation, death) at week 52 and its relationship to selected biomarkers at baseline., Results: Altogether, 211 subjects (154 patients with IPF and 57 control subjects) were enrolled; one-third of patients (n = 47) with IPF had progressed by week 52. Biomarkers CC-chemokine ligand 18 (CCL18), intercellular adhesion molecule 1, Krebs von den Lungen-6, surfactant protein (SP)-A, SP-D, matrix metallopeptidase 7, urokinase-type plasminogen activator receptor, and two novel biomarkers, human epididymis protein-4 (HE4) and prostasin, discriminated patients with IPF vs control subjects. There was no difference in baseline CCL18 concentration between progressors and nonprogressors at week 52 (area under the receiver operating characteristic curve, 0.62; corrected P = .161). No biomarkers were predictive for disease progression., Conclusions: Several biomarkers, including CCL18, were associated with IPF, but none predicted disease progression. Two novel biomarkers, HE4 and prostasin, were identified and warrant further investigation., (Copyright © 2018. Published by Elsevier Inc.)

Aim: To quantify circulating fibroblast activation protein (cFAP) and dipeptidyl peptidase 4 (cDPP4) protease activities in patients with rheumatoid arthritis (RA), systemic sclerosis (SSc), and a control group with mechanical back pain and to correlate plasma levels with disease characteristics., Methods: Plasma was collected from patients with RA (n = 73), SSc (n = 37) and control subjects (n = 26). DPP4 and FAP were quantified using specific enzyme activity assays., Results: Median cDPP4 was significantly lower in the RA group (P = 0.02), and SSc group (P = 0.002) compared with controls. There were no significant differences in median cFAP between the three groups. DPP4 and FAP demonstrated a negative correlation with inflammatory markers and duration of disease. There were no associations with disease subtypes in RA, including seropositive and erosive disease. Decreased cDPP4 was found in SSc patients with myositis. Plasma FAP was lower in RA patients receiving prednisone (P = 0.001) or leflunomide (P = 0.04), but higher with biologic agents (P = 0.01). RA patients receiving leflunomide also had decreased cDPP4 (P = 0.014). SSc patients receiving prednisone (P = 0.02) had lower cDPP4 but there was no association with cFAP., Conclusions: No association was found between cFAP and RA or SSc. Plasma DPP4 was decreased in RA and SSc when compared with controls. cDPP4 and cFAP correlated negatively with inflammatory markers and there were no significant correlations with disease characteristics in this RA cohort., (© 2016 Asia Pacific League of Associations for Rheumatology and John Wiley & Sons Australia, Ltd.)

Essentials Knowledge of genetic regulators of plasma factor VII activating protease (FSAP) levels is limited. We performed a genome-wide analysis of variants influencing FSAP activity in Scandinavian cohorts. We replicated an association for Marburg-1 and identified an association for a HABP2 stop variant. We identified a novel locus near ADCY2 as a potential additional regulator of FSAP activity., Summary: Background Factor VII-activating protease (FSAP) has roles in both coagulation and fibrinolysis. Recent data indicate its involvement in several other processes, such as vascular remodeling and inflammation. Plasma FSAP activity is highly variable among healthy individuals and, apart from the low-frequency missense variant Marburg-I (rs7080536) in the FSAP-encoding gene HABP2, determinants of this variation are unclear. Objectives To identify novel genetic variants within and outside of the HABP2 locus that influence circulating FSAP activity. Patients/Methods We performed an exploratory genome-wide association study (GWAS) on plasma FSAP activity amongst 3230 Swedish subjects. Directly genotyped rare variants were also analyzed with gene-based tests. Using GWAS, we confirmed the strong association between the Marburg-I variant and FSAP activity. HABP2 was also significant in the gene-based analysis, and remained significant after exclusion of Marburg-I carriers. This was attributable to a rare HABP2 stop variant (rs41292628). Carriers of this stop variant showed a similar reduction in FSAP activity as Marburg-I carriers, and this finding was replicated. A secondary genome-wide significant locus was identified at a 5p15 locus (rs35510613), and this finding requires future replication. This common variant is located upstream of ADCY2, which encodes a protein catalyzing the formation of cAMP. Results and Conclusions This study verified the Marburg-I variant to be a strong regulator of FSAP activity, and identified an HABP2 stop variant with a similar impact on FSAP activity. A novel locus near ADCY2 was identified as a potential additional regulator of FSAP activity., (© 2018 The Authors. Journal of Thrombosis and Haemostasis published by Wiley Periodicals, Inc. on behalf of International Society on Thrombosis and Haemostasis.)

Corin is a type II transmembrane serine protease that is highly expressed in the heart and plays a physiological role in the activation of natriuretic peptides. Corin is expressed primarily in myocytes, and it can enter the circulation. Circulating soluble corin has been found to be associated with various cardiovascular diseases, such as hypertension, heart failure, myocardial infarction, preeclampsia, and stroke. All these findings indicate that circulating soluble corin has the potential to be a sensitive and specific biomarker for risk prediction and prognostic assessment of cardiovascular diseases. However, there are certain challenges hindering the incorporation of circulating soluble corin into clinical practice. To provide new ideas based on the use of corin for risk prediction, prognostic assessment, and clinical treatment of cardiovascular diseases and to promote the implementation of corin as a routine laboratory index, we summarize the latest studies of the association between corin and cardiovascular diseases in recent years and offer some prospective proposals for future research on corin in this review., (Copyright © 2018 Elsevier B.V. All rights reserved.)

Proteasome inhibitors (PIs) such as bortezomib constitute an important part of the modern standard therapy for multiple myeloma (MM). In this study, we set out to assess whether proteasome concentration and chymotrypsin-like (ChT-L) activity could serve as potential biomarkers defining the likelihood of response to treatment with bortezomib, in order to identify patients who are more likely to respond to treatment with PI. We analysed proteasome concentration and ChT-L activity in the plasma of 78 patients with newly diagnosed MM during treatment with or without proteasome inhibitors. Values of all the studied parameters in the group of responders decreased sharply from the initial levels already after the third cycle of chemotherapy and remained significantly lower until the end of treatment. On the other hand, in the group of non-responders, there was an increase in the measured proteasome parameters already after the third cycle, and they remained high during the next cycles of therapy. We also showed that high baseline proteasome ChT-L activity values might prognosticate longer progression-free survival (PFS) in patients treated with PI. Our findings demonstrate that measuring plasma proteasome ChT-L activity can be used as a powerful biomarker for predicting clinical response to treatment and PFS in patients with newly diagnosed MM.

Traditional photoluminescence resonance energy transfer (PRET)-based sensors are widely applied, but still suffer from the severe background interference from in situ excitation. The afterglow nature of the persistent luminescence nanoparticles (PLNPs) allows optosensing after the stoppage of in situ illumination, and thus subtly overcomes that interference. We proposed a simple strategy for functionalizing PLNPs for bioanalytical applications and the new afterglow resonance energy transfer (ARET)-based assay for quantitative determination and imaging of fibroblast activation protein-alpha (FAPα) in live cells using Au-decorated Cr 3+ 0.004 :ZnGa 2 O 4 as donor and Cy5.5-KGPNQC-SH as acceptor. The ARET between the donor and acceptor quenches the afterglow of the donor, and the cleavage of peptide KGPNQC by FAPα inhibits the ARET and restores the afterglow of the donor. The ARET-based assay of FAPα, with the linear range of 0.1-2.0 mg·L -1 (1.2-22.9 nM), LOD of 11 μg·L -1 (115 pM), and RSD of 3.9% (for 0.5 mg·L -1 FAPα, n = 5), displays higher sensitivity, lower limit of detection (LOD), and better anti-interference capability than the corresponding PRET-based assay. Besides, the ARET-based sensors are lighted up by the FAPα-positive U87MG and MDA-MB-435 cells, but kept in the dark when incubated in the FAPα-negative AD293 cells. The proposed ARET-based sensor can detect FAPα of U87MG and MDA-MB-435 living cells in human serum with the spiked recoveries of 95.6-103%. Our data demonstrated a simple and effective strategy for bridging PLNPs to bioanalytical applications, and an attractive ARET assay of FAPα.