Brolucizumab and Platelet Activation and Reactivity.

Purpose: This study explores the potential interaction of brolucizumab with platelets and its effects on platelet activation and reactivity, crucial in retinal vasculitis and retinal vascular occlusion. Safety concerns remain of interest, although brolucizumab showed superior retinal efficacy and reduced injection frequency compared to other licensed anti-VEGF agents.

Methods: Resting and activated platelets of healthy volunteers were pretreated with brolucizumab at the following concentrations 0.

Ecto-NOX Disulfide-Thiol Exchanger 2 (ENOX2/tNOX) Is a Potential Prognostic Marker in Primary Malignant Melanoma and May Serve as a Therapeutic Target.

With an increasing incidence of malignant melanoma, new prognostic biomarkers for clinical decision making have become more important. In this study, we evaluated the role of ecto-NOX disulfide-thiol exchanger 2 (ENOX2/tNOX), a cancer- and growth-associated protein, in the prognosis and therapy of primary malignant melanoma. We conducted a tissue microarray analysis of immunohistochemical ENOX2 protein expression and The Cancer Genome Atlas (TCGA) RNA expression analysis, as well as viability assays and Western blots of melanoma cell lines treated with the ENOX2 inhibitor phenoxodiol (PXD) and BRAF inhibitor (BRAFi) vemurafenib.

The Proteolytic Activity of Neutrophil-Derived Serine Proteases Bound to the Cell Surface Arming Lung Epithelial Cells for Viral Defense.

The collaboration between cellular proteases and host cells is pivotal in mounting an effective innate immune defense. Of particular interest is the synergistic interaction between cathepsin G (CatG) and neutrophil elastase (NE), which are proteases secreted by activated neutrophils, and the human alveolar basal epithelial cell line (A549) and the human lung epithelial-like cell line (H1299), because of the potential implications for viral infection. Our study aimed to investigate the binding capacity of CatG and NE on the surface of A549 and H1299 cells through preincubation with purified CatG and NE; thereby, the proteolytic activity could be detected using activity-based probes.

Evidence for direct interaction between the oncogenic proteins E6 and E7 of high-risk human papillomavirus (HPV).

Human papillomaviruses (HPVs) are DNA tumor viruses that infect mucosal and cutaneous epithelial cells of more than 20 vertebrates. High-risk HPV causes about 5% of human cancers worldwide, and the viral proteins E6 and E7 promote carcinogenesis by interacting with tumor suppressors and interfering with many cellular pathways. As a consequence, they immortalize cells more efficiently in concert than individually.

From an Hsp90 - binding protein to a peptide drug.

The Lpl proteins represent a class of lipoproteins that was first described in the opportunistic bacterial pathogen , where they contribute to pathogenicity by enhancing F-actin levels of host epithelial cells and thereby increasing internalization. The model Lpl protein, Lpl1 was shown to interact with the human heat shock proteins Hsp90α and Hsp90ß, suggesting that this interaction may trigger all observed activities. Here we synthesized Lpl1-derived peptides of different lengths and identified two overlapping peptides, namely, L13 and L15, which interacted with Hsp90α.

Variation of Proteolytic Cleavage Sites towards the N-Terminal End of the S2 Subunit of the Novel SARS-CoV-2 Omicron Sublineage BA.2.12.1.

The prevalence of novel SARS-CoV-2 variants is also accompanied by an increased turnover rate and additional cleavage sites at the positions necessary for priming the Spike (S) protein. Of these priming sites, the proteolytically sensitive polybasic sequence of the activation loop at the S1/S2 interface and the S2' location within the S2 subunit of the S protein are cleaved by furin and TMPRSS2, which are important for the infection of the target cell. Neutrophils, migrating to the site of infection, secrete serine proteases to fight against pathogens.

Pulmonary Surfactant Proteins Are Inhibited by Immunoglobulin A Autoantibodies in Severe COVID-19.

Coronavirus disease 2019 (COVID-19) can lead to acute respiratory distress syndrome with fatal outcomes. Evidence suggests that dysregulated immune responses, including autoimmunity, are key pathogenic factors. To assess whether IgA autoantibodies target lung-specific proteins and contribute to disease severity.

A network of cytosolic (co)chaperones promotes the biogenesis of mitochondrial signal-anchored outer membrane proteins.

Signal-anchored (SA) proteins are anchored into the mitochondrial outer membrane (OM) via a single transmembrane segment at their N-terminus while the bulk of the proteins is facing the cytosol. These proteins are encoded by nuclear DNA, translated on cytosolic ribosomes, and are then targeted to the organelle and inserted into its OM by import factors. Recently, research on the insertion mechanisms of these proteins into the mitochondrial OM have gained a lot of attention.

Proteolytic Activity against the Distal Polybasic Tract of the Gamma Subunit of the Epithelial Sodium Channel ENaC in Nephrotic Urine.

Background: Experimental nephrotic syndrome in mice leads to proteolytic activation of the epithelial sodium channel ENaC, possibly involving the distal polybasic tract of its γ-subunit (183RKRK).

Objective: We sought to determine if urine samples from both nephrotic mice and a cohort of patients with acute nephrotic syndrome contain a specific proteolytic activity against this region of γ-ENaC.

Methods: A peptide substrate consisting of amino acids 180-194 of murine γ-ENaC was N-terminally coupled to a fluorophore, yielding AMCA-FTGRKRKISGKIIHK.

Immunogenic Cell Death, DAMPs and Prothymosin α as a Putative Anticancer Immune Response Biomarker.

The new and increasingly studied concept of immunogenic cell death (ICD) revealed a previously unknown perspective of the various regulated cell death (RCD) modalities, elucidating their immunogenic properties and rendering obsolete the notion that immune stimulation is solely the outcome of necrosis. A distinct characteristic of ICD is the release of danger-associated molecular patterns (DAMPs) by dying and/or dead cells. Thus, several members of the DAMP family, such as the well-characterized heat shock proteins (HSPs) HSP70 and HSP90, the high-mobility group box 1 protein and calreticulin, and the thymic polypeptide prothymosin α (proTα) and its immunoreactive fragment proTα(100-109), are being studied as potential diagnostic tools and/or possible therapeutic agents.

Occurrence of a novel cleavage site for cathepsin G adjacent to the polybasic sequence within the proteolytically sensitive activation loop of the SARS-CoV-2 Omicron variant: The amino acid substitution N679K and P681H of the spike protein.

The serine proteases neutrophil elastase (NE), proteinase 3 (PR3), cathepsin G (CatG), and neutrophil serine protease 4 (NSP4) are secreted by activated neutrophils as a part of the innate immune response against invading pathogens. However, these serine proteases might be adopted by viruses to mediate viral surface protein priming resulting in host cell entrance and productive infection. Indeed, NE and PR3 hydrolyze the scissile peptide bond within the proteolytically sensitive polybasic sequence of the activation loop of SARS-CoV-2 located at the S1/S2 interface of the Spike (S) protein; an amino acid motif which differs from SARS-CoV-1.

Sodium retention in nephrotic syndrome is independent of the activation of the membrane-anchored serine protease prostasin (CAP1/PRSS8) and its enzymatic activity.

Experimental nephrotic syndrome leads to activation of the epithelial sodium channel (ENaC) by proteolysis and promotes renal sodium retention. The membrane-anchored serine protease prostasin (CAP1/PRSS8) is expressed in the distal nephron and participates in proteolytic ENaC regulation by serving as a scaffold for other serine proteases. However, it is unknown whether prostasin is also involved in ENaC-mediated sodium retention of experimental nephrotic syndrome.

TAT-RHIM: a more complex issue than expected.

Murine cytomegalovirus protein M45 contains a RIP homotypic interaction motif (RHIM) that is sufficient to confer protection of infected cells against necroptotic cell death. Mechanistically, the N-terminal region of M45 drives rapid self-assembly into homo-oligomeric amyloid fibrils, and interacts with the endogenous RHIM domains of receptor-interacting serine/threonine protein kinases (RIPK) 1, RIPK3, Z-DNA-binding protein 1, and Toll/interleukin-1 receptor domain-containing adaptor-inducing interferon-β. Remarkably, all four aforementioned mammalian proteins harbouring such a RHIM domain are key components of inflammatory signalling and regulated cell death (RCD) processes.

Human Platelets Take up Anti-VEGF Agents.

Purpose: Growing evidence suggests different systemic exposure of anti-vascular endothelial growth factor (anti-VEGF) agents with repeated intravitreal application. Since the penetration of anti-VEGF agents through vascular barrier was reported, the interaction of anti-VEGF with nonresident platelets has become a topic of interest. The purpose of this study was to evaluate, with the help of visualization techniques, whether platelets take up the anti-VEGF agents ranibizumab, aflibercept, and bevacizumab.

Neutrophil Elastase and Proteinase 3 Cleavage Sites Are Adjacent to the Polybasic Sequence within the Proteolytic Sensitive Activation Loop of the SARS-CoV-2 Spike Protein.

Serine proteases neutrophil elastase (NE), protease 3 (PR3), cathepsin G (CatG), and neutrophil serine protease 4 (NSP4) are released by activated neutrophils swarming around the place of pathogen invasion to provoke an immune response. However, uncontrolled proteolytic activity of proteases results in various human diseases, including cardiovascular diseases, thrombosis, and autoimmunity. In addition, proteases can be hijacked by several viruses to prime virus-derived surface proteins and evade immune detection by entering into the host cell.

Detection and Characterization of Phosphorylation, Glycosylation, and Fatty Acid Bound to Fetuin A in Human Blood.

The hepatokine fetuin A (Fet A) has been associated with diverse pathological states such as insulin resistance, type 2 diabetes, macrovascular disease, and systemic ectopic and vascular calcification. Fet A may also play a role in tumor growth and metastasis. The biological activity of Fet A may be affected by various modifications, including phosphorylation, O- and N-glycosylation and fatty acid binding.

Proteasuria in nephrotic syndrome-quantification and proteomic profiling.

Nephrotic syndrome is characterized by urinary excretion of plasma proteases or proteasuria. There is a lack of data on the quantity, activity status and identity of these aberrantly filtered proteases. We established a fluorescence-based substrate assay to quantify protease activity in urine samples from healthy and nephrotic humans and mice.

Neutrophil extracellular trap-associated RNA and LL37 enable self-amplifying inflammation in psoriasis.

Psoriasis is an inflammatory skin disease with strong neutrophil (PMN) infiltration and high levels of the antimicrobial peptide, LL37. LL37 in complex with DNA and RNA is thought to initiate disease exacerbation via plasmacytoid dendritic cells. However, the source of nucleic acids supposed to start this initial inflammatory event remains unknown.

Development of a specific IgY-based ELISA for prothymosin alpha, a bioactive polypeptide with diagnostic and therapeutic potential.

Prothymosin alpha (ProTα) is a highly conserved polypeptide (109 amino acids in humans) with diagnostic and therapeutic potential; ProTα exerts intra- and extra-cellular biological functions associated with cell proliferation, apoptosis and immune regulation, while it has been suggested to act as a damage-associated molecular pattern (DAMP) or alarmin. In this work, chicken polyclonal anti-ProTα antibodies that had been developed several years ago were immunochemically evaluated and proven to retain immunoreactivity for ProTα, with remarkable thermal and pH stability. Moreover, the antibodies showed practically no cross-reactivity with a series of ProTα-fragments, eventually intracellularly produced -such as ProTα[1-28] (also known as Tα1) and ProTα[100-109], which exert biological activity and might be present in biological samples along with the intact molecule, being therefore highly specific for whole-length ProTα.

Antitumor Reactive T-Cell Responses Are Enhanced In Vivo by DAMP Prothymosin Alpha and Its C-Terminal Decapeptide.

Prothymosin α (proTα) and its C-terminal decapeptide proTα(100-109) were shown to pleiotropically enhance innate and adaptive immune responses. Their activities have been broadly studied in vitro, focusing primarily on the restoration of the deficient immunoreactivity of cancer patients' leukocytes. Previously, we showed that proTα and proTα(100-109) act as danger-associated molecular patterns (DAMPs), ligate Toll-like receptor-4, signal through TRIF- and MyD88-dependent pathways, promote the maturation of dendritic cells and elicit T-helper type 1 (Th1) immune responses in vitro, leading to the optimal priming of tumor antigen-reactive T-cell functions.

Different Forms of TFF3 in the Human Saliva: Heterodimerization with IgG Fc Binding Protein (FCGBP).

The peptide TFF3 is a member of a family of secretory lectins, and is typically synthesized by mucous epithelia together with mucins. It is mainly released from intestinal goblet cells as a high-molecular mass heterodimer with IgG Fc binding protein (FCGBP). Herein, we investigated human saliva by fast protein liquid chromatography (FPLC) and proteomics and identified high- and low-molecular-mass forms of TFF3.

Synthesis of a Novel Curcumin Derivative as a Potential Imaging Probe in Alzheimer's Disease Imaging.

Background: Curcumin has been of interest in the field of Alzheimer's disease. Early studies on transgenic mice showed promising results in the reduction of amyloid plaques.However, curcumin is very poorly soluble in aqueous solutions and not easily accessible to coupling as it contains only phenolic groups as potential coupling sites.