An engineered ultrahigh affinity bi-paratopic uPAR targeting agent confers enhanced tumor targeting.

Urokinase-type plasminogen activator receptor (uPAR) is overexpressed on tumor cells in multiple types of cancer and contributes to disease progression and metastasis. In this work, we engineered a novel bi-paratopic uPAR targeting agent by fusing the binding domains of two native uPAR ligands: uPA and vitronectin, with a flexible peptide linker. The linker length was optimized to facilitate simultaneous engagement of both domains to their adjacent epitopes on uPAR, resulting in a high affinity and avid binding interaction. Furthermore, the individual domains were affinity-matured using yeast surface display and directed evolution, resulting in a bi-paratopic protein with affinity in the picomolar to femtomolar range. This engineered uPAR targeting agent demonstrated significantly enhanced tumor localization in mouse tumor models compared to the native uPAR ligand and warrants further investigation as a diagnostic and therapeutic agent for cancer.

Soluble urokinase type plasminogen activator receptor (suPAR) and mortality in acute pulmonary embolism.

INTRODUCTION: The soluble urokinase-type plasminogen activator receptor (suPAR) potentially plays a role in immune-thrombosis, possibly by modulating plasmin activity or contributing to chemotaxis in a complex, poorly understood context. The role of suPAR levels in the short-term prognostic of patients with pulmonary embolism (PE) has not been evaluated. MATERIAL AND METHODS: This observational, prospective, single-center study enrolled consecutive patients aged 18 and above with confirmed acute symptomatic PE and no prior anticoagulant therapy. The primary objective was to assess the prognostic capacity of suPAR levels measured at the time of diagnosis in terms of mortality. RESULTS: Fifty-two patients, with a mean age of 73.8 years (±17), were included, with gender distribution evenly split at 50%. Seven (13.5%) patients died. The ROC curve for mortality yielded an AUC of 0.72 (95% CI 0.48-0.96), with an optimal suPAR cut-off of 5.5ng/mL. Bivariate analysis for suPAR>5.5ng/mL was associated with a crude odds ratio of 10 (95% CI 1.63-61.27; p=0.01) for 30-day mortality. Survival analysis showed a 30-day mortality hazard ratio of 8.33 (95% CI 1.69-40.99; p<0.01). CONCLUSION: suPAR emerges as a potential biomarker for short-term mortality prediction and holds the potential for enhanced stratification in patients with acute symptomatic PE.

PLAU promotes cell proliferation and migration of head and neck cancer via STAT3 signaling pathway.

It was reported that within the head and neck cancer (HNC) cell line CAL21 the epithelial-mesenchymal transition (EMT) and cell proliferation were promoted by Urokinase-Type Plasminogen Activator (PLAU) proteinase through TNFRSF12A. Additionally, in this paper HNC cell lines refer to Fadu and Tu686. A novel PLAU-STAT3 axis was found to be involved in HNC cell line proliferation and metastasis. PLAU expression in HNC samples was upregulated, besides, the elevated expression of PLAU was linked to the lower overall survival (OS) and disease-free survival (DFS). Ectopic PLAU expression promoted cell proliferation and migration, while PLAU knockdown exhibited opposite results. RNA-seq data identified the JAK-STAT signaling pathway, confirmed by western blotting. A recovery assay using S3I-201, a selective inhibitor of signal transducer and activator of transcription 3 (STAT3), indicated that PLAU promoted HNC cell line progression via STAT3 signaling in vitro. The oncogenic role of PLAU in HNC tumor growth in vivo was confirmed using xenograft models. In summary, we identified the tumorigenic PLAU function in the HNC progress. PLAU may represent a potential prognostic biomarker of HNC and the PLAU-STAT3 pathway might be considered a therapeutic target of HNC.

Positron emission computed tomography targeting urokinase plasminogen activator receptor (uPAR) in cancer: a systematic review.

INTRODUCTION: To provide an overview of the available literature data on clinical applications of positron emission tomography (PET) targeting the urokinase-type plasminogen activator receptor in oncology. METHODS: A literature search was conducted in PubMed, Web of Science and Scopus databases up to June 2023. The results were presented according to the PRISMA guidelines. The quality of the studies was assessed using the Critical Appraisal Skill Program checklist. RESULTS: Seven papers were selected for final analysis, involving 266 patients with solid tumors who underwent PET with uPAR-ligands. Thematic areas identified include feasibility studies (n = 2) on the safety, pharmacokinetics, and dosimetry of uPAR-targeting radiopharmaceuticals; uPAR-directed imaging in head and neck cancer (n = 2); uPAR PET in prostate cancer (n = 2); and the investigation of uPAR in neuroendocrine neoplasms (n = 1). Six of the seven studies used the radiopharmaceutical [68Ga]Ga-NOTA-AE105 while one study used [64Cu]Cu-DOTA-AE105. The studies showed protocol homogeneity, with static PET imaging at 20 minutes. The quality assessment revealed limitations such as small cohorts and the fact that all studies were performed by a single research group. CONCLUSIONS: uPAR-PET appears to be a promising imaging tool in well-selected oncological settings, but it needs to be validated by multicentre collaboration.

Corrigendum: Urokinase-type plasminogen activator and plasminogen activator inhibitor-1 complex as a serum biomarker for COVID-19.

[This corrects the article DOI: 10.3389/fimmu.2023.1299792.].

The Diagnostic Accuracy of Procalcitonin, Soluble Urokinase-Type Plasminogen Activator Receptors, and C-Reactive Protein in Diagnosing Urinary Tract Infections in the Emergency Department-A Diagnostic Accuracy Study.

Background: Urinary tract infections (UTIs) are a leading bacterial infection in the emergency department (ED). Diagnosing UTIs in the ED can be challenging due to the heterogeneous presentation; therefore, fast and precise tests are needed. We aimed to evaluate the diagnostic precision of procalcitonin (PCT), soluble urokinase plasminogen activator receptors (suPARs), and C-reactive protein (CRP) in diagnosing UTIs, grading the severity of UTIs, and ruling out bacteremia. Methods: We recruited adults admitted to three Danish EDs with suspected UTIs. PCT, suPAR, and CRP were used in index tests, while blood cultures, expert panel diagnosis, and severity grading were used in the reference tests. Logistic regression and area under the receiver operator characteristic curves (AUROCs) were utilized to evaluate the models and determine the optimal cut-offs. Results: We enrolled 229 patients. PCT diagnosed UTI with an AUROC of 0.612, detected severe disease with an AUROC of 0.712, and ruled out bacteremia with an AUROC of 0.777. SuPAR had AUROCs of 0.480, 0.638, and 0.605, while CRP had AUROCs of 0.599, 0.778, and 0.646. Conclusions: The diagnostic performance of PCT, suPAR, or CRP for UTIs or to rule out severe disease was poor. However, PCT can safely rule out bacteremia in clinically relevant numbers in ED patients suspected of UTI.

Gender-Specific Renoprotective Pathways in αMUPA Transgenic Mice Subjected to Acute Kidney Injury.

Acute kidney injury (AKI) is a serious health concern with high morbidity and high mortality worldwide. Recently, sexual dimorphism has become increasingly recognized as a factor influencing the severity of the disease. This study explores the gender-specific renoprotective pathways in αMUPA transgenic mice subjected to AKI. αMUPA transgenic male and female mice were subjected to ischemia-reperfusion (I/R)-AKI in the presence or absence of orchiectomy, oophorectomy, and L-NAME administration. Blood samples and kidneys were harvested 48 h following AKI for the biomarkers of kidney function, renal injury, inflammatory response and intracellular pathway sensing of or responding to AKI. Our findings show differing responses to AKI, where female αMUPA mice were remarkably protected against AKI as compared with males, as was evident by the lower SCr and BUN, normal renal histologically and attenuated expression of NGAL and KIM-1. Moreover, αMUPA females did not show a significant change in the renal inflammatory and fibrotic markers following AKI as compared with wild-type (WT) mice and αMUPA males. Interestingly, oophorectomized females eliminated the observed resistance to renal injury, highlighting the central protective role of estrogen. Correspondingly, orchiectomy in αMUPA males mitigated their sensitivity to renal damage, thereby emphasizing the devastating effects of testosterone. Additionally, treatment with L-NAME proved to have significant deleterious impacts on the renal protective mediators, thereby underscoring the involvement of eNOS. In conclusion, gender-specific differences in the response to AKI in αMUPA mice include multifaceted and keen interactions between the sex hormones and key biochemical mediators (such as estrogen, testosterone and eNOS). These novel findings shed light on the renoprotective pathways and mechanisms, which may pave the way for development of therapeutic interventions.

Clinical value of soluble urokinase-type plasminogen activator receptor in predicting sepsis-associated acute kidney injury.

BACKGROUND: Sepsis-associated acute kidney injury (S-AKI) is a critical illness and is often associated with high morbidity and mortality rates. The soluble urokinase-type plasminogen activator receptor (suPAR) is an important immune mediator and is involved in kidney injury. However, its diagnostic value in S-AKI patients remains unclear. Therefore, we assessed the early predictive value of suPAR for S-AKI patients. METHODS: We prospectively enrolled adult patients, immediately after fulfilling the sepsis-3 criteria. Plasma suPAR levels at 0-, 12-, 24-, and 48-h post-sepsis diagnosis were measured. S-AKI development was the primary outcome. S-AKI risk factors were analyzed using logistic regression, and the value of plasma suPAR for early S-AKI diagnosis was assessed using receiver operating characteristic (ROC) curves. RESULTS: Of 179 sepsis patients, 63 (35.2%) developed AKI during hospitalization. At 12-, 24-, and 48-h post-sepsis diagnosis, plasma suPAR levels were significantly higher in patients with S-AKI than in patients without S-AKI (p < 0.05). The plasma suPAR had the highest area under the ROC curve of 0.700 (95% confidence interval (CI), 0.621-0.779) at 24-h post-sepsis diagnosis, at which the best discrimination ability for S-AKI was achieved with suPAR of ≥6.31 ng/mL (sensitivity 61.9% and specificity 71.6%). Logistic regression analysis showed that suPAR at 24-h post-sepsis diagnosis remained an independent S-AKI risk factor after adjusting for mechanical ventilation, blood urea nitrogen, and pH. CONCLUSIONS: The findings suggest that plasma suPAR may be a potential biomarker for early S-AKI diagnosis.

Circulating miR-10b, soluble urokinase-type plasminogen activator receptor, and plasminogen activator inhibitor-1 as predictors of non-small cell lung cancer progression and treatment response.

BACKGROUND: Despite advances in lung cancer treatment, most lung cancers are diagnosed at an advanced stage. Expression of microRNA10b (miR-10b) and fibrinolytic activity, as reflected by soluble urokinase-type plasminogen activator receptor (suPAR) and plasminogen activator inhibitor 1 (PAI-1), are promising biomarker candidates. OBJECTIVE: To assess the expression of miR-10b, and serum levels of suPAR and PAI-1 in advanced stage non-small cell lung cancer (NSCLC) patients, and their correlation with progression, treatment response and prognosis. METHODS: The present prospective cohort and survival study was conducted at Dharmais National Cancer Hospital and included advanced stage NSCLC patients diagnosed between March 2015 and September 2016. Expression of miR-10b was quantified using qRT-PCR. Levels of suPAR and PAI-1 were assayed using ELISA. Treatment response was evaluated using the RECIST 1.1 criteria. Patients were followed up until death or at least 1 year after treatment. RESULTS: Among the 40 patients enrolled, 25 completed at least four cycles of chemotherapy and 15 patients died during treatment. Absolute miR-10b expression ⩾ 592,145 copies/µL or miR-10b fold change ⩾ 0.066 were protective for progressive disease and poor treatment response, whereas suPAR levels ⩾ 4,237 pg/mL was a risk factor for progressive disease and poor response. PAI-1 levels > 4.6 ng/mL was a protective factor for poor response. Multivariate analysis revealed suPAR as an independent risk factor for progression (ORa⁢d⁢j, 13.265; 95% confidence intervals (CI), 2.26577.701; P= 0.006) and poor response (ORa⁢d⁢j, 15.609; 95% CI, 2.221-109.704; P= 0.006), whereas PAI-1 was an independent protective factor of poor response (ORa⁢d⁢j, 0.127; 95% CI, 0.019-0.843; P= 0.033). CONCLUSIONS: Since miR-10b cannot be used as an independent risk factor for NSCLC progression and treatment response, we developed a model to predict progression using suPAR levels and treatment response using suPAR and PAI-1 levels. Further studies are needed to validate this model.

Diagnostic Value of Preoperative uPAR-PET/CT in Regional Lymph Node Staging of Oral and Oropharyngeal Squamous Cell Carcinoma: A Prospective Phase II Trial.

The detection of lymph node metastases is a major challenge in oral and oropharyngeal squamous cell carcinoma (OSCC and OPSCC). 68Ga-NOTA-AE105 is a novel positron emission tomography (PET) radioligand with high affinity to urokinase-type plasminogen activator receptor (uPAR), a receptor expressed on the surfaces of tumor cells. The aim of this study was to investigate the diagnostic value of uPAR-PET/CT (computerized tomography) in detecting regional metastatic disease in patients with OSCC and OPSCC compared to the current imaging work-up. In this phase II trial, patients with OSCC and OPSCC referred for surgical treatment were prospectively enrolled. Before surgery, 68Ga-NOTA-AE105 uPAR-PET/CT was conducted, and SUVmax values were obtained from the primary tumor and the suspected lymph nodes. Histology results from lymph nodes were used as the standard of truth of metastatic disease. The diagnostic values of 68Ga-uPAR-PET/CT were compared to conventional routine preoperative imaging results (CT and/or MRI). The uPAR expression in resected primary tumors and metastases was determined by immunohistochemistry and quantified digitally (H-score). A total of 61 patients underwent uPAR-PET/CT. Of the 25 patients with histologically verified lymph node metastases, uPAR-PET/CT correctly identified regional metastatic disease in 14 patients, with a median lymph node metastasis size of 14 mm (range 3-27 mm). A significant correlation was found between SUVmax and the product of the H-score and tumor depth (r = 0.67; p = 0.003). The sensitivity and specificity of uPAR-PET/CT in detecting regional metastatic disease were 56% and 100%, respectively. When added to CT/MRI, uPAR-PET was able to upstage 2/11 (18%) of patients with occult metastases and increase the sensitivity to 64%. The sensitivity and specificity of 68Ga-NOTA-AE105 uPAR-PET/CT were equivalent to those of CT/MRI. The significant correlation between SUVmax and uPAR expression verified the target specificity of 68Ga-NOTA-AE105. Despite the target specificity, the sensitivity of imaging is too low for nodal staging and it cannot replace neck dissection.

Urokinase-type plasminogen activator (uPA) regulates invasion and matrix remodelling in colorectal cancer.

Background: Cancer cells remodel their local physical environment through processes of matrix reorganisation, deposition, stiffening and degradation. Urokinase-type plasminogen activator (uPA), which is encoded by the PLAU gene, is an extracellular proteolytic enzyme known to be involved in cancer progression and tumour microenvironment (TME) remodelling. Perturbing uPA therefore has a strong potential as a mechano-based cancer therapy. This work is a bioengineering investigation to validate whether 1) uPA is involved in matrix degradation and 2) preventing matrix degradation by targeting uPA can reduce cancer cell invasion and metastasis. Methods: To this aim, we used an engineered 3D in vitro model, termed the tumouroid, that appropriately mimics the tumour's native biophysical environment (3 kPa). A CRISPR-Cas9 mediated uPA knockout was performed to introduce a loss of function mutation in the gene coding sequence. Subsequently, to validate the translational potential of blocking uPA action, we tested a pharmacological inhibitor, UK-371,801. The changes in matrix stiffness were measured by atomic force microscopy (AFM). Invasion was quantified using images of the tumouroid, obtained after 21 days of culture. Results: We showed that uPA is highly expressed in invasive breast and colorectal cancers, and these invasive cancer cells locally degrade their TME. PLAU (uPA) gene knock-out (KO) completely stopped matrix remodelling and significantly reduced cancer invasion. Many invasive cancer gene markers were also downregulated in the PLAU KO tumouroids. Pharmacological inhibition of uPA showed similarly promising results, where matrix degradation was reduced and so was the cancer invasion. Conclusion: This work supports the role of uPA in matrix degradation. It demonstrates that the invasion of cancer cells was significantly reduced when enzymatic breakdown of the TME matrix was prevented. Collectively, this provides strong evidence of the effectiveness of targeting uPA as a mechano-based cancer therapy.

A novel genetically-encoded bicyclic peptide inhibitor of human urokinase-type plasminogen activator with better cross-reactivity toward the murine orthologue.

The inhibition of human urokinase-type plasminogen activator (huPA), a serine protease that plays an important role in pericellular proteolysis, is a promising strategy to decrease the invasive and metastatic activity of tumour cells. However, the generation of selective small molecule huPA inhibitors has proven to be challenging due to the high structural similarity of huPA to other paralogue serine proteases. Efforts to generate more specific therapies have led to the development of cyclic peptide-based inhibitors with much higher selectivity against huPA. While this latter property is desired, the sparing of the orthologue murine poses difficulties for the testing of the inhibitor in preclinical mouse model. In this work, we have applied a Darwinian evolution-based approach to identify phage-encoded bicyclic peptide inhibitors of huPA with better cross-reactivity towards murine uPA (muPA). The best selected bicyclic peptide (UK132) inhibited huPA and muPA with Ki values of 0.33 and 12.58 µM, respectively. The inhibition appears to be specific for uPA, as UK132 only weakly inhibits a panel of structurally similar serine proteases. Removal or substitution of the second loop with one not evolved in vitro led to monocyclic and bicyclic peptide analogues with lower potency than UK132. Moreover, swapping of 1,3,5-tris-(bromomethyl)-benzene with different small molecules not used in the phage selection, resulted in an 80-fold reduction of potency, revealing the important structural role of the branched cyclization linker. Further substitution of an arginine in UK132 to a lysine resulted in a bicyclic peptide UK140 with enhanced inhibitory potency against both huPA (Ki = 0.20 µM) and murine orthologue (Ki = 2.79 µM). By combining good specificity, nanomolar affinity and a low molecular mass, the bicyclic peptide inhibitor developed in this work may provide a novel human and murine cross-reactive lead for the development of a potent and selective anti-metastatic therapy.

pH/Temperature Dual-Responsive Protein-Polymer Conjugates for Potential Therapeutic Hypothermia in Ischemic Stroke.

Thrombolytic therapy for ischemic stroke still has several limitations, such as a narrow therapeutic time window and adverse effects. Therapeutic hypothermia is a neuroprotective strategy for stroke. In this study, we developed pH/temperature dual-responsive protein-polymer conjugates (PEG-uPA-PEG-PPG-PEG) by modifying a urokinase-type plasminogen activator (uPA) with polyethylene glycol (PEG) and poly(ethylene glycol)-block-poly(propylene glycol)-block-poly(ethylene glycol) (PEG-PPG-PEG, a thermosensitive polymer) via pH-sensitive imine bonds and disulfide bonds, respectively. At 37 °C and pH 7.4 (normothermia and physiological pH), PEG-uPA-PEG-PPG-PEG exhibits antiprotease hydrolysis and masked bioactivity of uPA due to the protective effect of the polymer segments wrapped around the protein surface. However, at 33 °C and pH 6.0 (hypothermia and pH at the thrombotic site), uPA loses the protective effect and recovers its bioactivity due to PEG dissociation and PEG-PPG-PEG stretching. The masked bioactivity of uPA at normothermia and physiological pH could reduce the risk of acute hemorrhage complication, and the recovery of protein activity at acidic pH and 33 °C is of great significance for thrombolytic therapy at mild hypothermia. Thus, PEG-uPA-PEG-PPG-PEG provides promising potential for therapeutic hypothermia in ischemic stroke.

Urokinase-Type Plasminogen Activator Receptor (uPAR) Expression and [64Cu]Cu-DOTA-AE105 uPAR-PET/CT in Patient-Derived Xenograft Models of Oral Squamous Cell Carcinoma.

PURPOSE: [64Cu]Cu-DOTA-AE105 urokinase-type plasminogen activator receptor (uPAR)-PET/CT is a novel and promising imaging modality for cancer visualization, although it has not been tested in head and neck cancer patients nor in preclinical models that closely resemble these heterogenous tumors, i.e., patient-derived xenograft (PDX) models. The aim of the present study was to establish and validate oral squamous cell carcinoma (OSCC) PDX models and to evaluate [64Cu]Cu-uPAR-PET/CT for tumor imaging in these models. PROCEDURES: PDX flank tumor models were established by engrafting tumor tissue from three patients with locally advanced OSCC into immunodeficient mice. [64Cu]Cu-DOTA-AE105 was injected in passage 2 (P2) mice, and [64Cu]Cu-uPAR-PET/CT was performed 1 h and 24 h after injection. After the last PET scan, all animals were euthanized, and tumors dissected for autoradiography and immunohistochemical (IHC) staining. RESULTS: Three PDX models were established, and all of them showed histological stability and unchanged heterogenicity, uPAR expression, and Ki67 expression through passages. A significant correlation between uPAR expression and tumor growth was found. All tumors of all models (n=29) showed tumor uptake of [64Cu]Cu-DOTA-AE105. There was a clear visual concordance between the distribution of uPAR expression (IHC) and [64Cu]Cu-DOTA-AE105 uptake pattern in tumor tissue (autoradiography). No significant correlation was found between IHC (H-score) and PET-signal (SUVmax) (r=0.34; p=0.07). CONCLUSIONS: OSCC PDX models in early passages histologically mimic donor tumors and could serve as a valuable platform for the development of uPAR-targeted imaging and therapeutic modalities. Furthermore, [64Cu]Cu-uPAR-PET/CT showed target- and tumor-specific uptake in OSCC PDX models demonstrating the diagnostic potential of this modality for OSCC patients.

Perturbations in podocyte transcriptome and biological pathways induced by FSGS associated circulating factors.

Background: Focal segmental glomerulosclerosis (FSGS) is frequently associated with heavy proteinuria and progressive renal failure requiring dialysis or kidney transplantation. However, primary FSGS also has a ~40% risk of recurrence of disease in the transplanted kidney (rFSGS). Multiple circulating factors have been identified to contribute to the pathogenesis of primary and rFSGS including soluble urokinase-type plasminogen activator receptor (suPAR) and patient-derived CD40 autoantibody (CD40autoAb). However, the downstream effector pathways specific to individual factors require further study. The tumor necrosis factor, TNF pathway activation by one or more circulating factors present in the sera of patients with FSGS has been supported by multiple studies. Methods: A human in vitro model was used to study podocyte injury measured as the loss of actin stress fibers. Anti-CD40 autoantibody was isolated from FSGS patients (recurrent and non-recurrent) and control patients with ESRD due to non-FSGS related causes. Two novel human antibodies-anti-uPAR (2G10) and anti-CD40 antibody (Bristol Meyer Squibb, 986090) were tested for their ability to rescue podocyte injury. Podocytes treated with patient derived antibody were transcriptionally profiled using whole human genome microarray. Results: Here we show that podocyte injury caused by sera from FSGS patients is mediated by CD40 and suPAR and can be blocked by human anti-uPAR and anti-CD40 antibodies. Transcriptomic studies to compare the molecules and pathways activated in response to CD40 autoantibody from rFSGS patients (rFSGS/CD40autoAb) and suPAR, identified unique inflammatory pathways associated with FSGS injury. Conclusions: We identified several novel and previously described genes associated with FSGS progression. Targeted blockade of suPAR and CD40 pathways with novel human antibodies showed inhibition of podocyte injury in FSGS.

Urokinase-type plasminogen activator promotes corneal epithelial migration and nerve regeneration.

Urokinase-type plasminogen activator (uPA) is a serine protease that plays a central role in the pericellular fibrinolytic system, mediates the degradation of extracellular matrix proteins and activation of growth factors, and contributes to the regulation of various cellular processes including cell migration and adhesion, chemotaxis, and angiogenesis. The corneal epithelium responds rapidly to injury by initiating a wound healing process that involves cell migration, cell proliferation, and tissue remodeling. It is innervated by sensory nerve endings that play an important role in the maintenance of corneal epithelial homeostasis and in the wound healing response. We here investigated the role of uPA in corneal nerve regeneration and epithelial resurfacing after corneal injury with the use of uPA-deficient mice. Both the structure of the corneal epithelium and the pattern of corneal innervation in uPA-/- mice appeared indistinguishable from those in uPA+/+ mice. Whereas the cornea was completely resurfaced by 36-48 h after epithelial scraping in uPA+/+ mice, however, such resurfacing required at least 72 h in uPA-/- mice. Restoration of epithelial stratification was also impaired in the mutant mice. Fibrin zymography revealed that the expression of uPA increased after corneal epithelial scraping and returned to basal levels in association with completion of re-epithelialization in wild-type animals. Staining of corneal whole-mount preparations for ßIII-tubulin also revealed that the regeneration of corneal nerves after injury was markedly delayed in uPA-/- mice compared with uPA+/+ mice. Our results thus demonstrate an important role for uPA in both corneal nerve regeneration and epithelial migration after epithelial debridement, and they may provide a basis for the development of new treatments for neurotrophic keratopathy.

The accuracy of soluble urokinase-type plasminogen activator receptor for the diagnosis of neonatal sepsis: a meta-analysis.

Background: Neonatal sepsis is one of the major causes of morbidity and mortality in newborns. However, atypical clinical manifestations and symptoms make the early diagnosis of neonatal sepsis a challenge. Relatively high-serum soluble urokinase-type plasminogen activator receptor (suPAR) has been implicated as a diagnostic biomarker for adult sepsis. Therefore, the meta-analysis is intended to explore the diagnostic value of suPAR for neonatal sepsis. Methods: The PubMed, Cochrane Library, Embase, Web of Science, China National Knowledge Infrastructure, China Biological Medicine Disk, and Wanfang databases were retrieved from inception to 31 December 2022 to collect diagnostic accuracy studies about suPAR for neonatal sepsis. Two reviewers independently screened the literature, extracted data, and assessed the risk of bias in the included studies using the quality assessment of diagnostic accuracy studies-2 (QUADAS-2) tool. Then, a meta-analysis was performed using Stata 15.0 software. Results: A total of six articles involving eight studies were included. The results of the meta-analysis showed that the pooled sensitivity, specificity, positive likelihood ratio, negative likelihood ratio, and diagnostic odds ratio were 0.89 [95%CI (0.83-0.93)], 0.94 [95%CI (0.77-0.98)], 14 [95%CI (3.5-55.2)], 0.12 [95%CI (0.08-0.18)], and 117 [95%CI (24-567)], respectively. The area under the curve (AUC) of summary receiver operator characteristic (SROC) curves was 0.92 [95%CI (0.90-0.94)]. Sensitivity analysis confirmed the stability of the results, and publication bias was not observed. Fagan's nomogram results demonstrated the clinical availability of the findings. Conclusion: Current evidence suggests that suPAR has potential diagnostic value for neonatal sepsis. Owing to the limited quality of the included studies, more high-quality studies are needed to verify the above conclusion.

Soluble Urokinase-Type Plasminogen Activator Receptor (suPAR) Is a Biomarker Associated with Left Ventricular Hypertrophy in the Elderly, Specifically in Women.

Left ventricular hypertrophy (LVH) may result in the development of heart failure, which is widespread among people of advanced age. The pathophysiology of LVH is complex and its biochemical pathways are not fully understood in this group. Elevated soluble urokinase-type plasminogen activator receptor (suPAR), a biomarker of immune activation, including fibrosis, reflects subclinical organ damage in systematic diseases. The present study assesses the clinical role of suPAR measurement in determination of LVH-associated cardiac disorders in the elderly. The studied population consisted of 238 individuals aged 76-91 years; of these, 139 (58%) were diagnosed with LVH. Serum biomarkers measurement (suPAR, troponin T, NT-proBNP and CRP) and echocardiography were performed in all subjects. The suPAR level was significantly higher in the LVH group (4.01 vs. 3.82 ng/mL, p = 0.033) and correlated with the parameters of cardiac diastolic function. Stepwise logistic regression found suPAR level (OR = 1.55, p = 0.016), BMI (OR = 1.17, p = 0.0003) and hypertension (OR = 2.42, p = 0.046) to be independently associated with LVH in women. In men, the strongest predictors of LVH were hypertension (OR = 7.52, p = 0.014) and BMI (OR = 1.42, p = 0.032). The observations indicate suPAR as a promising marker reflecting LVH, especially in women at advanced age, independent of age-associated cardiac remodeling.

Relationship between systemic inflammation and lung injury induced by chromate exposure: A cross-sectional study in workers.

Hexavalent chromium [Cr(VI)] compounds, known as "Group I Human Carcinogen" and "Category I Respiratory Sensitizer", posed great challenges to the respiratory system. A cross-sectional study was undertaken among chromate workers. Serum club cell protein 16 (CC16) and soluble urokinase-type plasminogen activator receptor (suPAR) were measured using ELISA. Thirteen macrophage-related mediators were tested using cytometric bead array. After controlling for sex, age, smoking status, drinking status and BMI, each increase of one-unit of Ln-transformed blood Cr was related to the increase of IL-1beta [Beta (95% CI), 7.22(1.14, 13.29)%, P = 0.021], IL-23 [8.5(1.15, 15.85)%, P = 0.021], IFN-gamma [3.14(0.15, 6.13)%, P = 0.040], and suPAR [9.31(2.5, 16.12) %, P = 0.008], as well as the increase of CC16 by 3.88(0.42, 7.34) % (P = 0.029). Moreover, these inflammatory mediators played an mediation role in the rise of CC16 caused by Cr(VI). The exposure-response curve analysis revealed a substantial nonlinear association of IFN-gamma and suPAR with CC16, thus the mediation effect of INF-gamma and suPAR required cautious interpretation. The positive connection between macrophage-related mediators was stronger in the high exposure group than in the low exposure group, suggesting that high concentration of chromate might promote a complex interplay within the immune system.

High-throughput optofluidic screening of single B cells identifies novel cross-reactive antibodies as inhibitors of uPAR with antibody-dependent effector functions.

The urokinase-type plasminogen activator receptor (uPAR) is an essential regulator for cell signaling in tumor cell proliferation, adhesion, and metastasis. The ubiquitous nature of uPAR in many aggressive cancer types makes uPAR an attractive target for immunotherapy. Here, we present a rapid and successful workflow for developing cross-reactive anti-uPAR recombinant antibodies (rAbs) using high-throughput optofluidic screening of single B-cells from human uPAR-immunized mice. A total of 80 human and cynomolgus uPAR cross-reactive plasma cells were identified, and selected mouse VH/VL domains were linked to the trastuzumab (Herceptin®) constant domains for the expression of mouse-human chimeric antibodies. The resulting rAbs were characterized by their tumor-cell recognition, binding activity, and cell adhesion inhibition on triple-negative breast cancer cells. In addition, the rAbs were shown to enact antibody-dependent cellular cytotoxicity (ADCC) in the presence of either human natural killer cells or peripheral blood mononuclear cells, and were evaluated for the potential use of uPAR-targeting antibody-drug conjugates (ADCs). Three lead antibodies (11857, 8163, and 3159) were evaluated for their therapeutic efficacy in vivo and were shown to suppress tumor growth. Finally, the binding epitopes of the lead antibodies were characterized, providing information on their unique binding modes to uPAR. Altogether, the strategy identified unique cross-reactive antibodies with ADCC, ADC, and functional inhibitory effects by targeting cell-surface uPAR, that can be tested in safety studies and serve as potential immunotherapeutics.