Cell Surface Research Articles

Real-ambient PM2.5 induced corneal epithelial barrier disruption through Wnt/β-catenin signaling

Continued daily exposure to fine particulate matter (PM2.5) is linked to increasing risks of ocular surface diseases. However, further study is needed to understand how real-ambient PM2.5 disrupts the barrier function of the corneal epithelial layers and its underlying mechanism. In our study, we utilized a real-ambient PM2.5 exposure system to investigate its effects on the corneal epithelial barrier in C57BL/6Jmice over 4 and 8 weeks. The mean concentration of PM2.5 in the exposure chambers over 8 weeks was 140.18 μg/m3. Following 4 and 8 weeks of continuous PM2.5 exposure, we observed disorganized cellular arrangements in the corneal epithelium of mice. Moreover, PM2.5 exposure led to a significant loss of microvilli on the surface of corneal epithelial cells and noticeable disconnections among epithelial cell layers. Subsequent in vitro analysis revealed that 100 μg/mL PM2.5 activated the Wnt/β-catenin signaling pathway in corneal epithelium, resulting in decreased expression 1.81 fold and 2.25 fold of E-cadherin and ZO-1, respectively, ultimately impairing the corneal epithelial barrier function. Our findings provide the knowledge base for promoting eye health in the context of atmospheric pollution.

In-situ impedance diagnosis experiment and equivalent circuit modeling based on distribution of relaxation time method for unitized regenerative proton exchange membrane fuel cells

In-situ impedance diagnosis experiment and equivalent circuit modeling based on distribution of relaxation time method for unitized regenerative proton exchange membrane fuel cells

Structural Insights into Helix–Loop–Helix Peptides for “Ligand-Targeting” Intracellular Drug Delivery via VEGF Receptor-Mediated Endocytosis

As a new alternative to antibody-drug conjugates, we developed “ligand-targeting” peptide-drug conjugates (PDCs), in which conformationally constrained helix-loop-helix (HLH) peptide M49 targeting human vascular endothelial growth factor-A (VEGF) was used as a drug carrier. The biochemical study showed that HLH peptide M49 made a complex with VEGF in the extracellular environment, and then the M49/VEGF complex interacts with the receptor on the cell surface to induce cellular internalization via the endocytic pathway. Here, we present an X-ray crystal structure of the M49/VEGF complex at 1.5 Å resolution using a protein crystal grown in microgravity. The structure illustrated the “ligand-targeting” cellular uptake mechanism for intracellular drug delivery and the molecular basis on the peptide-VEGF binding mode with tight binding and high target specificity. In addition, mutational studies and thermodynamic analysis provided information on the driving forces of the complex formation. This work would contribute to the design of mid-size molecular-targeting peptides as well as HLH peptides, advancing the research in drug discovery and chemical biology.

Integrated single-cell transcriptomic analyses identify a novel lineage plasticity-related cancer cell type involved in prostate cancer progression

Cancer cell plasticity is the ability of neoplastic cells to alter their identity and acquire new biological properties under microenvironmental pressures. In prostate cancer (PCa), lineage plasticity often results in therapy resistance and trans-differentiation to neuroendocrine (NE) lineage. However, identifying the cancer cells harboring lineage plasticity-related status remains challenging. Based on 13 multi-center human PCa bulk transcriptomic cohorts (samples=3314) and 9 bulk transcriptomic datasets derived from PCa experimental models, we established an integrated lineage plasticity-related gene signature, termed LPSig. Leveraging this gene signature, AUCell enrichment analysis was applied to identify the cell population with high lineage plasticity from a comprehensive single-cell RNA-sequencing (scRNA-seq) meta-atlas assembled by us, which consisted of 10 public human PCa scRNA-seq datasets (samples=93, cells=222,529). Moreover, additional scRNA-seq dataset of human PCa, multiplex immunohistochemistry staining for human PCa tissues, invitro and invivo functional experiments, as well as qPCR and Western blot analyses were employed to validate our findings. We found that LPSig could finely capture the dynamics of tumor lineage plasticity throughout the progression of PCa, accurately estimating the status of lineage plasticity. Based on LPSig, we identified a previously undefined minority population of lineage plasticity-related PCa cells (LPCs) from the human PCa scRNA-seq meta-atlas assembled by this study. Furthermore, in-depth dissection revealed pivotal roles of LPCs in trans-differentiation, tumor recurrence, and poor patient survival during PCa progression. Furthermore, we identified HMMR as a representative cell surface marker for LPCs, which was validated using additional scRNA-seq datasets and multiplexed immunohistochemistry. Moreover, HMMR was transcriptionally inhibited by androgen receptor (AR), and was required for the aggressive adenocarcinoma features and NE phenotype. Our study uncovers a novel population of lineage plasticity-related cells with low AR activity, stemness-like traits, and elevated HMMR expression, that may facilitate poor prognosis in PCa. This work was supported by National Key R&D Program of China (2022YFA0807000), National Natural Science Foundation of China (82160584), Advanced Prostate Cancer Diagnosis and Treatment Technology Innovation Team of Kunming Medical University (CXTD202216), and Reserve Talents of Young and Middle-aged Academic Leaders in Yunnan Province (202105AC160013).

Silver cementation mechanism for leaching silicon solar cells in nitric acid

Silicon solar panels are often overlooked in e-waste recycling technology, even though they contain precious silver (Ag). In order to help meet future global Ag demands and prevent contamination of the environment, all the Ag from end-of-life modules must be recovered instead of landfilled. The most mature Ag recycling recipes use high concentration nitric acid (HNO3) solutions often in combination with heating and agitation. After the Ag is leached, chemical precipitation or electrochemistry is used to recover metallic Ag. However, the process of Ag leaching in the HNO3 system with competing elements from silicon solar cells is not well understood. In this paper, we investigate the thermodynamics governing Ag leaching in low-concentration HNO3 without agitation or heating to expand fundamental knowledge in support of Ag recovery efforts from end-of-life solar panels. ICP-OES is used to quantify the amount of Ag leached in the HNO3 solution over time. Scanning electron microscopy (SEM) and energy-dispersive spectroscopy (EDS) are used to study the changes on the silicon solar cell surface. Our results suggest when trace tin (Sn) is used in solar cell fingers, it causes Ag to cement in dendritic form.

Subcellular expression of CD30 in cutaneous mastocytosis-An important factor for targeted treatment.

The subcellular distribution of CD30 on mast cells and the presence of eosinophils in cutaneous mastocytosis require further investigation, especially as the cell surface expression of CD30 is critical for the therapeutic response of systemic mastocytosis to brentuximab vedotin. Investigation of 147 biopsy specimens from 143 patients with cutaneous mastocytosis for mast cell density and distribution, frequency of CD30 expression, CD30 staining patterns, and presence and distribution of eosinophils. Correlation with clinical patterns. Retrospective multicenter immunohistochemical study of CD30 expression, eosinophils and basic clinical data in cutaneous mastocytosis. CD30 expression was found in all samples (cut-off: ≥1%), whereby the staining was predominantly cytoplasmic in 99% of the samples. Additional membrane staining was detected in 62% of the samples. Surface expression of CD30 was more common in biopsy specimens with a high mast cell burden and in biopsy specimens with a higher CD30 expression rate. Eosinophils were admixed in 58% of the samples. Females and older patients showed a trend of a lower mast cell burden. Retrospective study on formalin-fixed and paraffin-embedded tissue without functional analysis. Most cases of cutaneous mastocytosis show cell surface expression of CD30 expression and is, therefore, in principle, accessible for therapy with antibodies against CD30, provided the overall situation of the patient warrants.

Commentary on: Li et al; Ca2+ transients on the T cell surface trigger rapid integrin activation in a timescale of seconds. Nature Communications (2024)

Commentary on: Li et al; Ca2+ transients on the T cell surface trigger rapid integrin activation in a timescale of seconds. Nature Communications (2024)

Generation and characterization of a monoclonal antibody fab fragment targeting PBP2a in methicillin-resistant Staphylococcus aureus

Methicillin-resistant Staphylococcus aureus (MRSA) is one of the main pathogens associated with nosocomial and community infections that are difficult to treat owing to its resistance to all β-lactams and other classes of antibiotics. Reports of MRSA demonstrate the pathogen relevance and urgency for developing innovative diagnostic and treatment strategies against this microorganism. In this context, monoclonal antibodies (mAbs) represent a powerful tool for such purposes. Beta-lactam resistance in MRSA is caused by penicillin-binding protein 2a (PBP2a). The characteristics of PBP2a make this protein a potential target for immunobiologicals to combat this pathogen. This study describes the development of a recombinant Fab fragment from a mAb directed against the PBP2a protein, designed to identify and treat MRSA infections. The Fd and light chain coding sequences for Fab expression were amplified and ligated into the mammalian cell expression vector. Recombinant DNA constructs were used to transfect Expi293F cells expressing anti-PBP2a Fab. A purification based on ion-exchange chromatography was used for Fab separation, followed by analysis of antigen target recognition and interaction, either with the isolated antigen or with the antigen on the MRSA cell surface. The experimental approach allowed us to obtain significant Fab expression levels in the Expi293F system when transfecting the cells with the genetic constructs developed in pCDNA3.4 vector. Antigen target interaction assays revealed the capacity of Fab to recognize and interact with the PBP2a protein. Biodistribution analysis indicated serum Fab presence, in the serum, kidneys, lungs, and spleen, and a plasma half-life averaging 6–8 h.

Structure changes and carotenoids release of tomato during in vitro dynamic digestion: Effect of heating and oil addition

There is still a gap between the food processing and carotenoids release and structure degradation during digestion. This study investigated the effect of heating and coconut oil addition on the digestion behavior of tomatoes during in vitro dynamic digestion. Coconut oil and heating increased gastric retention, and the value of heat-treated tomatoes with coconut oil maintained at a highest level throughout the gastric digestion. The contents of lycopene and β-carotene increased after heating and coconut oil addition. After stimulated intestinal digestion, coconut oil and heating increased the particle size of tomato slurry. Besides, heat-treated tomatoes released more particles under the light microscopy and SEM observation, while the oil-treated tomatoes showed rougher cell surfaces. Heating and coconut oil also significantly increased the bioaccessibility of lycopene to 70 % ± 5 % and 81 % ± 4 %, respectively. These findings would provide theoretical guidance to develop tomato-derived foods with high bioaccessibility.

Fully human monoclonal antibody targeting the cysteine-rich substrate-interacting region of ADAM17 on cancer cells

ADAM17 sheds EGFR/erbB ligands and triggers oncogenic pathways that lead to the progression of solid tumors. We targeted the ADAM17 disintegrin and cysteine rich domain region (D+C) to generate a panel of single-chain antibody fragments (scFvs) that selectively bind to the D or C domains of ADAM17, but not of ADAM10 or ADAM19. From the panel, we selected one scFv, referred to as C12, based on its high binding affinity towards the target, and re-formatted it to a full IgG for further studies. High-resolution cryo-electron microscopy studies documented that the mAb binds to the ADAM17 C-domain that in ADAM proteases, notably ADAM10 and ADAM17, is known to impart substrate-specificity. The C12 mAb significantly inhibited EGFR phosphorylation in cancer cell lines by hindering the cleavage of EGFR ligands tethered to the cell surface. This inhibition provides a mechanism for potential anti-tumor effects, and indeed C12 diminished the viability of a variety of EGFR-expressing cancer cell lines. Cell-based ELISA studies revealed that C12 preferentially bound to activated ADAM17 present on tumor cells, as compared to the autoinhibited ADAM17 that is the predominant form on HEK293 and other non-tumor cells. C12 also exhibited tumor growth inhibition in an ovarian cancer xenograft mouse model. Consistent with its selective tumor cell binding in vitro, radioimmuno PET (positron emission tomography) imaging with 89Zr-DFO-C12 in mouse xenograft models confirmed tumoral accumulation of the C12 mAb.

Engraftment of a Surrogate Antigen onto Tumor Cell Surface via pHLIP Peptide to Universally Target CAR-T Cell Therapy to Solid Tumors

CAR-T cells and monoclonal antibodies (mAbs) are immunotherapeutics that have shown efficacies against certain malignancies. However, their broad application is hindered by the scarcity of tumor-associated antigens on tumor cell surfaces. Previous investigations unveiled the unique capacity of pH-low insertion peptide (pHLIP) to anchor to plasma membranes under acidic conditions. Considering that an acidic tumor microenvironment is a hallmark of solid tumors, we engineered a novel peptide, Myc-pHLIP, by tethering a surrogate epitope tag, the c-Myc-tag, to pHLIP. We evaluated the efficiency of Myc-pHLIP in inserting the artificial c-Myc-tag onto the plasma membrane of malignant cells and determined if this engraftment could convert it into a therapeutic target for CAR-T cells or mAbs. Our in vitro experiments demonstrated that incubating Myc-pHLIP with tumor cells in acidic media triggered significant killing by either Myc-targeted CAR-T cells (Myc-CAR-T), or by an anti-Myc mAb in the presence of NK cells. In vivo studies demonstrated substantial antitumor effects with sequential administration of Myc-pHLIP followed by either Myc-CAR-T or Myc-mAb. These findings establish that Myc-pHLIP has the potential to act as a universal surrogate tumor antigen capable of directing CAR-T cells or mAbs to treat any solid tumors by concurrently targeting both malignant and stromal cells.

Lymphocyte Antigen 6 Family Member D (LY6D) Affects Stem Cell Phenotype and Progression of Pancreatic Adenocarcinoma.

The membrane-bound protein lymphocyte antigen 6 family member D (LY6D), a marker of early B cell lineage is reportedly expressed in several human malignancies and has been implicated in cancer stemness. However, its expression and role in cancer stemness remain largely unexplored in pancreatic ductal adenocarcinoma (PDAC). The aim of this study was to clarify the role of LY6D in PDAC. We conducted functional analysis of LY6D to evaluate its impact on the malignant features of PDAC cells in vitro. Using our in-house developed stem cell separation technique, which isolates cells with low proteasome activity and CD44 v9 cell surface marker for cancer stem cells, we performed sphere formation and chemosensitivity tests and tumor formation assay in mice, through knockdown of LY6D expression. Immuno-histopathological analysis was also conducted to reveal the clinical significance of LY6D in PDAC. In vitro functional assays demonstrated that LY6D was critically involved in promoting the cancer malignant phenotype, including increased invasive ability, drug resistance, migration capacity, and cancer stemness. Immunohistopathological analysis revealed that high LY6D expression levels were associated with high recurrence rates and poorer prognosis in PDAC. Our study showed that LY6D is a novel prognostic indicator and plays a key role in regulation of cancer stemness in PDAC.

MTOR maintains endothelial cell integrity to limit lung vascular injury

The functional and structural integrity of the endothelium is essential for vascular homeostasis. Loss of barrier function in quiescent and migratory capacity in proliferative endothelium causes exuberant vascular permeability, a cardinal feature of many inflammatory diseases including acute lung injury (ALI). However, the signals governing these fundamental endothelial cell (EC) functions are poorly understood. Here, we identify Mechanistic Target of Rapamycin (MTOR) as an important link in preserving the barrier integrity and migratory/angiogenic responses in EC and preventing lung vascular injury and mortality in mice. Knockdown of MTOR in EC altered cell morphology, impaired proliferation and migration, and increased endocytosis of cell surface VE-Cadherin leading to disrupted barrier function. MTOR-depleted EC also exhibited reduced VE-Cadherin and VEGFR2 levels mediated in part by autophagy. Similarly, lungs from mice with EC-specific MTOR deficiency displayed spontaneous vascular leakage marked by decreased VE-Cadherin and VEGFR2 levels, indicating that MTOR deficiency in EC is sufficient to disrupt lung vascular integrity and may be a key pathogenic mechanism of ALI. Indeed, MTOR as well as VEGFR2 and VE-Cadherin levels were markedly reduced in injured mouse lungs or EC. Importantly, EC-targeted gene transfer of MTOR cDNA, either prophylactically or therapeutically, mitigated inflammatory lung injury, and improved lung function and survival in mouse models of ALI. These findings reveal an essential role of MTOR in maintaining EC function, identify loss of endothelial MTOR as a key mechanism of lung vascular injury, and show the therapeutic potential of EC-targeted MTOR expression in combating ALI and mortality in mice.

Facilitating and restraining virus infection using cell-attachable soluble viral receptors

SARS-CoV-2 uses the receptor binding domain (RBD) of its spike protein to recognize and infect host cells by binding to the cell surface receptor angiotensin converting enzyme 2 (ACE2). The ACE2 receptor is composed of peptidase domain (PD), collectrin-like domain, transmembrane domain, and short cytoplasmic domain, and may exist as a dimer on cell surface. The RBD binding site is located atop of the ACE2 PD, but the involvement of other domains in virus infection is uncertain. We found that the ACE2 PD alone, whether anchored to cell membrane via a glycosylphosphatidylinositol anchor or attached to another surface protein, is fully functional as a receptor for spike-mediated cell fusion and virus infection. However, for ACE2 to function as the viral receptor, the RBD binding site must be positioned in close proximity to the cell membrane. Elevating the surface height of ACE2 using long and rigid protein spacers reduces or eliminates cell fusion and virus infection. Moreover, we found that the RBD-targeting neutralizing antibodies, nanobodies, and de novo designed miniprotein binders, when present on cell surface, also act as viral receptors, facilitating cell fusion and virus infection. Our data demonstrate that RBD binding and close membrane proximity are essential properties for a receptor to effectively mediate SARS-CoV-2 infection. Importantly, we show that soluble RBD-binders can be engineered to make cells either susceptible or resistant to virus infection, which has significant implications for antiviral therapy and various virus-mediated applications.

Roles of PDGF/PDGFR signaling in various organs.

Platelet-derived growth factors (PDGFs) ligands and their corresponding receptors, PDGF receptor (PDGFR)α and PDGFRβ, play a crucial role in controlling diverse biological functions, including cell growth, viability and migration. These growth factors bind to PDGFRs, which are receptor tyrosine kinases present on the surface of target cells. The interaction between PDGFs and PDGFRs induces receptor dimerization and subsequent activation through auto-phosphorylation, which in turn triggers a cascade of intracellular signaling pathways. PDGF/PDGFR signaling is essential for maintaining normal physiological functions, including tissue regeneration and growth. However, dysregulation of this signaling pathway leads to pathological conditions, including fibrosis, atherosclerosis, and cancer development in various organs. The pathological impact of PDGF/PDGFR signaling primarily stems from its capacity to promote excessive cell proliferation, enhanced migration, and increased extracellular matrix deposition, resulting in tissue overgrowth, scarring, and abnormal vessel formation. These processes are integral to the pathogenesis of fibrotic, neoplastic, and vascular disorders. Therefore, understanding these pathways is crucial for developing targeted treatments designed to inhibit PDGF/PDGFR signaling in these diseases. This review delves into the dual role of PDGF/PDGFR signaling in both physiological and pathophysiological contexts across different organs and provides insights into current pharmacological therapies designed to target the PDGF signaling pathway. INTRODUCTION Platelet-derived growth factors (PDGFs) are key signaling molecules that interact with specific cell to modulate various cellular responses. Upon binding to their receptors (PDGFRs), PDGFs initiate dimerization and tyrosine phosphorylation, which activates downstream signaling pathways. The PDGF signaling network comprises four ligands-PDGF-A, PDGF-B, PDGFC, and PDGF-D, that interact with two receptors, PDGFRα and PDGFRβ [1-6]. PDGFRα exhibits broader ligand specificity, binding to PDGF-A, PDGF-B, PDGF-C homodimers, and PDGFAB heterodimers, whereas PDGFRβ specifically binds to PDGFB and PDGF-D homodimers. Under both physiological and pathol.

The Role of the Swollen State in Cell Proliferation.

Cell swelling is known to be involved in various stages of the growth of plant cells and microorganisms but in mammalian cells how crucial a swollen state is for determining the fate of the cellular proliferation remains unclear. Recent evidence has increased our understanding of how the loss of the cell surface interactions with the extracellular matrix at early mitosis decreases the membrane tension triggering curvature changes in the plasma membrane and the activation of the sodium/hydrogen (Na +/H +) exchanger (NHE1) that drives osmotic swelling. Such a swollen state is temporary, but it is critical to alter essential membrane biophysical parameters that are required to activate Ca2 + channels and modulate the opening of K + channels involved in setting the membrane potential. A decreased membrane potential across the mitotic cell membrane enhances the clustering of Ras proteins involved in the Ca2 + and cytoskeleton-driven events that lead to cell rounding. Changes in the external mechanical and osmotic forces also have an impact on the lipid composition of the plasma membrane during mitosis.

Nano-Biomechanical Investigation of Phosphatidylserine-Mediated Ebola Viral Attachment via Human Gas6 and Axl

The Ebola virus is a deadly pathogen that has been threatening public health for decades. Recent studies have revealed alternative viral invasion routes where Ebola virus approaches cells via interactions among phosphatidylserine (PS), PS binding ligands such as Gas6, and TAM family receptors such as Axl. In this study, we investigate the interactions among phosphatidylserine on the Ebola viral-like particle (VLP) membrane, human Gas6, and human Axl using atomic force microscope-based single molecule force spectroscopy to compare their binding strength and affinity from a biomechanical perspective. The impact of calcium ions on their interactions is also studied and quantified to provide more details on the calcium-dependent phosphatidylserine-Gas6 binding mechanism. Our results indicate that, in the presence of calcium ions, the binding strengths of VLP-Gas6 and VLP-Gas6-Axl increase but are still weaker than that of Gas6-Axl, and the binding affinity of VLP-Gas6 and VLP-Gas6-Axl is largely improved. The binding strength and affinity of Gas6-Axl basically remain the same, indicating no impact in the presence of calcium ions. Together, our study suggests that, under physiological conditions with calcium present, the Ebola virus can utilize its membrane phosphatidylserine to dock on cell surface via Gas6-Axl bound complex.

Rosmarinic Acid Exhibits Antifungal and Antibiofilm Activities Against Candida albicans: Insights into Gene Expression and Morphological Changes

Candida species, opportunistic pathogens that cause various infections, pose a significant threat due to their ability to form biofilms that resist antifungal treatments and immune responses. The increasing resistance of Candida spp. and the limited availability of effective treatments have prompted the research of natural compounds as alternative therapies. This study assessed the antifungal properties of RA against Candida species, focusing on its impact on C. albicans biofilms and the underlying mechanisms. The antifungal efficacy of RA was evaluated using the CLSI M27-A3 microdilution method on both fluconazole-susceptible and -resistant strains. Biofilm formation by C. albicans was assessed through a crystal violet assay, while its antibiofilm activity was analyzed using an MTT assay and field emission scanning electron microscopy (FESEM). Gene expression related to biofilm formation was studied using quantitative real-time PCR (qRT-PCR), and statistical analysis was performed with an ANOVA. Among the 28 Candida strains tested, RA exhibited minimum inhibitory concentration (MIC) values ranging from 160 to 1280 μg/mL. At a 640 μg/mL concentration, it significantly reduced the expression of genes associated with adhesion (ALS3, HWP1, and ECE1), hyphal development (UME6 and HGC1), and hyphal cAMP-dependent protein kinase regulators (CYR1, RAS1, and EFG1) in RAS1-cAMP-EFG1 pathway (p < 0.05). FESEM analysis revealed a reduction in hyphal networks and disruptions on the cell surface. Our study is the first to demonstrate the effects of RA on C. albicans adhesion, hyphae development, and biofilm formation through gene expression analysis with findings supported by FESEM. This approach distinguishes our study from previous studies on the effect of RA on Candida. However, the high MIC values of RA limit its antifungal potential. Therefore, more extensive research using innovative methods is required to increase the antifungal effect of RA.

Heat shock protein HSPA8 impedes hemin-induced cellular-toxicity in liver

Accumulation of hemin in cells, tissues, and organs is one of the major pathological conditions linked to hemolytic diseases like malaria. Pro-oxidant hemin confers high toxicity following its accumulation. We tested the cellular toxicity of hemin on HepG2 cells by exploring modulation in various cellular characteristics. Hemin reduces the viability of HepG2 cells and brings about visible morphological changes. Hemin causes perforations on the surface of HepG2 cells observed through SEM. Hemin leads to the extracellular release of liver enzymes and reduces the wound-healing potential of HepG2 cells. Hemin leads to the fragmentation of HepG2 DNA, arrests the cell cycle progression in the S-phase and induces apoptosis in these cells. Western blot analysis revealed that hemin triggers both the extrinsic and intrinsic pathways of apoptosis in HepG2 cells. We have already shown that the cytoprotective protein HSPA8 can polymerize hemin and minimize its toxicity. Similar experiments with hemin in the presence and absence of HSPA8 showed that HSPA8 reverses all the tested toxic effects of hemin on HepG2 cells. The protection from hemin toxicity in HepG2 cells appeared to be due to the extracellular polymerization of hemin by HSPA8.

In Search of the Role of Three-Finger Starfish Proteins

Three-finger proteins (TFPs), or Ly6/uPAR proteins, are characterized by the beta-structural LU domain containing three protruding “fingers” and stabilized by four conserved disulfide bonds. TFPs were initially characterized as snake alpha-neurotoxins, but later many studies showed their regulatory roles in different organisms. Despite a known expression of TFPs in vertebrates, they are poorly studied in other taxa. The presence of TFPs in starfish was previously shown, but their targets and functional role still remain unknown. Here, we analyzed expression, target, and possible function of the Lystar5 protein from the Asterias rubens starfish using bioinformatics, qPCR, and immunoassay. First, the presence of Lystar5 homologues in all classes of echinoderms was demonstrated. qPCR revealed that mRNA of Lystar5 and LyAr2 are expressed mainly in coelomocytes and coelomic epithelium of Asterias, while mRNA of other TFPs, LyAr3, LyAr4, and LyAr5, were also found in a starfish body wall. Using anti-Lystar5 serum from mice immunized by a recombinant Lystar5, we confirmed that this protein is expressed on the surface of coelomocytes and coelomic epithelium cells. According to ELISA, a recombinant analogue of Lystar5 bound to the membrane fraction of coelomocytes and coelomic epithelium but not to the body wall or starfish arm tip. Analysis by LC-MALDI MS/MS suggested integrin α-8-like protein expressed in the coelomocytes and coelomic epithelium as a target of Lystar5. Thus, our insights propose the important role of TFPs in regulation of starfish physiology and show prospects for their further research.