Levels Of CD59 Research Articles

CD63 as a potential biomarker for patients with ovarian cancer.

Exosomes play an important role in regulating physiological processes and mediating the systemic dissemination of various types of cancer. We investigated the association of exosomal tetraspanins CD9, CD63, and CD81 in patients with ovarian cancer (OC). We measured the plasma tetraspanins CD9, CD63, and CD81 by enzyme-linked immunosorbent assay in 91 patients who underwent treatment for OC between April 2018 and March 2024. Additionally, we analyzed clinical pathologic factors, chemotherapy response, and prognosis. In terms of stages, CD63 expression was significantly higher in patients with stage IV compared to those with stage I OC (p=0.003). In terms of histological type, CD63 expression was significantly higher in high-grade serous carcinoma (HGSC) than in clear cell carcinoma (CCC) with OC (p=0.009). Furthermore, CD63 levels were significantly higher in advanced-stage, HGSC than in patients with early-stage, non-HGSC and early-stage, HGSC OC (p=0.045 and p=0.002, respectively). In the Neoadjuvant chemotherapy (NAC) of 12 patients with OC assessed as having either a partial response (PR) or complete response (CR), CD63 was significantly decreased (p=0.043), whereas perforin was significantly increased (p=0.001). In the NAC of 16 patients with OC, CD63 of the response rate to chemotherapy tended to differ between the progressive disease (PD) and PR/CR groups (p=0.056). A moderate inverse correlation was observed between CD63 and perforin levels (R=0.638, R2=0.428, p=0.008). CD63 could be a potential biomarker for all types of OC patients.

Impact of UPF2 on the levels of CD81 on extracellular vesicles.

Extracellular vesicles (EVs) are involved in cell-to-cell communication. Following uptake, EV cargo molecules, including DNA, RNA, lipids, and proteins, influence gene expression and molecular signaling in recipient cells. Although various studies have identified disease-specific EV molecules, further research into their biogenesis and secretion mechanisms is needed for clinical application. Here, we investigated the role of UPF2 in regulating the biogenesis and components of EVs. Notably, UPF2 promoted the expression of CD81, a membrane protein marker of EVs, as UPF2 silencing decreased CD81 levels in EVs, both inside the cell and secreted. In contrast, the expression levels of CD63 increased, without altering the size or numbers of EVs. In addition, reducing UPF2 levels did not affect the total number of EVs but lowered production of CD81-positive EVs and reduced the efficiency of uptake by recipient cells. Collectively, our findings uncover a novel function for UPF2 in regulating the production of CD81 and changing EV properties.

Shedding of membrane complement inhibitors CD59 and CD46 into the circulation is associated with poor prognosis in acute coronary syndrome patients: a cohort study

IntroductionThe role of the complement inhibitory proteins CD46 and CD59 in the immune response to an acute coronary syndrome (ACS) is unknown. We investigated the relationships between the shedding of CD46 and CD59 into the circulation, reflected by plasma levels of soluble CD46 and CD59, and the risk for post-ACS complications.MethodsWe measured plasma sCD46 and sCD59 in a cohort of 546 ACS patients within 24 h after hospital admission, and after 6-weeks in a subgroup of 114 patients. Study outcomes were incident heart failure (HF), major adverse cardiovascular events (MACE) and mortality during a median follow-up period of up to 3.3 years. Echocardiography at 1-year was performed in the follow-up subgroup.ResultsElevated sCD46 and sCD59 were correlated with increased levels of inflammatory mediators and metalloproteinases in plasma, and were associated with increased risk for MACE in Cox proportional hazard models adjusted for cardiovascular risk factors and revascularization [HR 95% CI 1.24 (1.02–1.52), p = 0.034 for sCD46 and 1.18 (1.00–1.38), p = 0.049 for sCD59]. Elevated sCD59 was also associated with higher incidence of HF [HR 95% CI 1.41 (1.15–1.74), p = 0.001], and with lower left ventricular ejection fraction at 1-year post-ACS (Spearman r = − 0.234, p = 0.020). We found no associations between plasma levels of the proteins at 6 weeks and outcomes.ConclusionsShedding of the complement regulators CD46 and CD59 in plasma in the acute phase of ACS is associated with a negative prognosis. Plasma sCD46 and sCD59 could reflect the degree of local immune activation and serve as prognostic biomarkers in ACS patients.

Diagnostic Implications of CD63 and CD64 Expression Levels and FcγRIIIA 158 V/F Gene Polymorphism in Primary Immune Thrombocytopenia Adult Patients.

Immune thrombocytopenic purpura (ITP) is an acquired autoimmune disease characterized by reduced platelet counts due to immune system dysregulation caused by many factors, including genetics, autoimmune diseases, infections, and inflammations. Therefore, the current study aimed to evaluate immunological markers such as the expression level of lysosomal associated membrane protein 3 (LAMP-3), also known as CD63, and the expression level of Fc-gamma receptor I (FcγRI), also known as CD64 and also investigate the association of Fc-gamma receptor IIIA (FcγRIIIA) 158 V/F polymorphism to the risk of ITP. A total of 180 subjects; 60 ITP patients, 60 patients with thrombocytopenia of other causes and 60 controls were enrolled into our study. The expression level of CD63 was done using reverse transcription quantitative PCR (RTqPCR), while CD64 expression level was done by flow cytometry. The polymorphism of FcγRIIIA 158 V/F gene was analyzed by polymerase chain reaction followed by restriction fragment length polymorphism (PCR-RFLP) analysis. Finally, CD63 and CD64 protein-protein interactions were done by using the STRING online database. The expression of CD63 was significantly elevated in ITP patients than thrombocytopenia patients and healthy control. Also there was high expression level of CD64 on granulocytes and monocytes from ITP patients than other groups. Receiver operating characteristic curve (ROC curve) analysis of CD63 showed an area under the curve (AUC) revealed of 1.00, sensitivity of 100% and specificity of 100%; while for CD64 on granulocytes, AUC of 0.998 as well as a sensitivity of 96.66% and specificity of 93.33%. Regarding FcγRIIIa 158 V/F polymorphism, all patients and healthy volunteers included in this study showed the wild FF genotype. The expression of both CD63 and CD64 were significantly increased in ITP patients and could be good biomarkers to diagnose ITP. Additionally, there is no association between FcγRIIIa 158 V/F polymorphism and the risk of ITP disease.

BMSCs-derived exosomes carrying miR-668-3p promote progression of osteoblasts in osteonecrosis of the femoral head: Expression of proteins CD63 and CD9

Recently, exosomes that are derived from bone marrow mesenchymal stem cells (BMSCs) have garnered considerable interest due to their significant roles in the processes of bone regeneration and repair. Among the various molecular components present within these exosomes, miR-668-3p has emerged as a pivotal microRNA that may be instrumental in modulating the function and proliferation of osteoblasts, the cells responsible for bone formation. The primary objective of this research was to examine the enhancing effects of BMSC-derived exosomes that are enriched with miR-668-3p on the advancement of osteoblasts in the context of osteonecrosis of the femoral head. Furthermore, the study aimed to analyze how the expression of specific exosomal proteins, namely CD63 and CD9, influences this biological process. To conduct the investigation, BMSCs were isolated from healthy rat models, followed by the extraction of their secreted exosomes. The subsequent phase of the study involved assessing the proliferation and differentiation of osteoblasts by introducing the exosomes enriched with miR-668-3p into an experimental setup representing osteonecrosis of the femoral head. The findings revealed that exosomes derived from BMSCs, which contained miR-668-3p, significantly enhanced the proliferation of osteoblasts as well as the expression of key osteogenic marker genes. Notably, the levels of CD63 and CD9 proteins were markedly increased in the treated groups, indicating that the mechanisms underlying this promotion might involve cell adhesion and the endocytic uptake of exosomes.

Isolation and analysis of the exosomal membrane proteins in bullous pemphigoid

ABSTRACT Background Bullous pemphigoid (BP) is a severe autoimmune sub-epidermal bullous disease. Exosomes are small extracellular vesicles secreted by most cell types. The exosomal membrane proteins are implicated in various biological and pathological pathways. This study aims to explore the potential roles of exosomes in BP pathomechanism. Research design We collected plasma samples from 30 BP patients and 31 healthy controls. Nanoparticle tracking analysis (NTA) was used to analyze the size and concentration of exosomes. The immunogold labelling experiment and extracellular vesicle (EV) array were performed to detect the content and distribution of exosomes. Results The exosomes from both the BP and control groups’ plasma were successfully extracted. EV Array showed that CD63 and CD9 levels were significantly higher in the BP group than in the control group (p < 0.05). Expression levels of the BP180 NC16A and intracellular domain (ICD) were higher in the anti-BP180 positive group versus the controls (p < 0.05). The active BP group exhibits higher CD63 and BP180 ICD protein concentrations than the control or inactive BP groups (p < 0.05). Conclusion BP180 autoantigen fragments were expressed on the exosomal membrane in BP patients. The BP180 ICD and CD63 on exosomes could potentially be novel biomarkers for monitoring disease activity.

Urinary Extracellular Vesicles for Non-Invasive Quantification of Principal Cell Damage in Kidney Transplant Recipients.

The objective of the present study was to compare principal cell-specific aquaporin-2 (AQP2) abundances in urinary extracellular vesicles (uEVs) on the first postoperative day in deceased-donor kidney transplant recipients without and with acute kidney injury. We measured uEV markers (CD9 and CD63) and the abundances of proximal tubular sodium-glucose transporter 2, distal tubular sodium/chloride cotransporter, and principal cell-specific aquaporin-2 using Western blotting of urine. uEV-AQP2 levels were normalized to living donor controls. The validation cohort consisted of 82 deceased-donor kidney transplant recipients who had a median age of 50 years (IQR 43 to 57 years). A total of 32% of recipients had acute kidney injury. The median uEV-AQP2 was significantly higher in recipients with acute kidney injury compared to immediate allograft function (2.05; IQR 0.87 to 2.83; vs. 0.81; IQR 0.44 to 1.78; p < 0.01). The Youden index indicated a uEV-AQP2 threshold of 2.00. Stratifying uEV-AQP2 into quartiles showed that recipients with higher uEV-AQP2 levels had higher rates of acute kidney injury (Cochran-Armitage, p = 0.001). The discovery cohort showed elevated CD9, CD63, and uEV-AQP2 levels in urine from recipients with acute kidney injury compared to immediate allograft function. We were able to quantify the damage of principal cells after kidney transplant to predict acute kidney injury using uEV-AQP2.

Erythropoietin Effect on Complement Activation in Chronic Kidney Disease.

The complement system is an important part of innate immunity. Despite its known protective role, the complement system may contribute to increased inflammation and tissue injury in cases where its balanced activation is disrupted. The kidneys have been shown to be largely affected by complement dysregulation. The aim of the present study was to investigate the effect of erythropoietin administration, on the complement system, in chronic kidney disease patients. The study involved 20 patients with CKD who received erythropoietin and measurements of levels of complement factors C3a and C5a and complement regulatory proteins (CregPs) CD55, CD46, and CD59. An increase in serum C3a and C5a levels was observed in response to EPO therapy. The increase in C3a was statistically significant (p < 0.05) and concurrent with a statistically significant decrease in CD55 in CD4+ T cells (p < 0.05) and B cells (p < 0.05) and CD59 levels in CD4+ and CD8+ T cells (p < 0.05) at completion of EPO therapy compared with healthy controls. The above observations demonstrate that EPO induces complement activation in patients undergoing EPO therapy with a simultaneous restriction of CRegPs expression, thus possibly allowing the uncontrolled complement activation, which may contribute to tissue injury and disease progression.

Salivary levels of azurocidin and soluble azurophilic granules in periodontal disease.

Periodontitis is an infection-driven inflammatory condition of the periodontium. Neutrophils are one of the most important first-line immune cells that protect against pathogen microorganisms in the saliva, but they may also mediate tissue death in inflammatory disorders. The aim of our study was to estimate salivary levels of azurocidin and extracellular azurophilic granules cluster of differentiation (CD63) as biomarkers of neutrophil activation in patients with periodontal diseases and to study the correlation between the levels of these two biomarkers and clinical periodontal parameters. The study included 60 patients with periodontal disease (30 patients with periodontitis and 30 with gingivitis) and 25 healthy controls. The assessed parameters were bleeding on probing, the plaque index, clinical attachment loss, and probing pocket depth. Saliva samples were taken from each study participant, and azurocidin and CD63 levels were measured using ELISA. Azurocidin and CD63 levels were significantly higher in patients with periodontitis and patients with gingivitis than in controls (P < 0.05), and significantly higher in patients with periodontitis than in patients with gingivitis (P < 0.05). Moreover, we found a significant positive correlation between the two biomarkers with clinical attachment loss in the periodontitis group. This study has shown that increased salivary azurocidin and extracellular CD63 levels are associated with enhanced innate response in periodontal disease and can be considered biomarkers of neutrophil activation.

Low-dose atorvastatin calcium combined with evolocumab: effect on regulatory proteins, lipid profiles, and cardiac function in coronary heart disease patients.

To assess the effects of combining low-dose atorvastatin calcium with evolocumab on complement regulatory protein levels, lipid profiles, and cardiac function in patients with coronary heart disease (CHD). A prospective randomized controlled study was conducted, with 180 CHD patients enrolled from Guang'anmen Hospital, China Academy of Chinese Medical Sciences, and the Second Hospital of Shanxi Medical University between February 2022 and April 2023. These patients were randomly assigned to either the control group (n = 90), receiving low-dose atorvastatin calcium, or the research group (n = 90), receiving a combination of low-dose atorvastatin calcium and evolocumab. The changes in cardiac function indices, levels of blood lipids and complement proteins, incidence of side effects, and cardiovascular events were compared between the two groups. After treatment, both groups exhibited reductions in blood lipid levels. However, the research group demonstrated significantly lower levels of total cholesterol (TC), triglycerides (TG), and low-density lipoprotein cholesterol (LDL-C) compared to the control group (all P < 0.001). Additionally, improvements in cardiac function indices were observed in both groups, with the research group displaying greater enhancements in cardiac output (CO), stroke volume (SV), and left ventricular ejection fraction (LVEF). Furthermore, the levels of complement regulatory proteins, including CD45, CD46, CD55, and CD59, increased in both groups after treatment, with the research group exhibiting significantly higher levels (all P < 0.001). Notably, the research group also exhibited a lower incidence of cardiovascular events. The combined use of low-dose atorvastatin calcium and evolocumab effectively modulates complement regulatory protein levels, optimizes blood lipid profiles, and enhances cardiac function in patients with CHD. This combination therapy represents a promising approach for management of CHD.

Resveratrol modulates miRNA machinery proteins in different types of colon cancer cells

Abstract Objectives Resveratrol (RSV) is a stilbenoid compound that shows anticancer activity in many cancer cells. Exosomes might affect carcinogenesis and the development of colorectal cancer by affecting communication between tumor cells in the tumor microenvironment via their cargo content miRNA. The aim of this study is to determine the effect of RSV on the expression of Dicer, Ago2, eIf2α, CD-9, CD-63, and exosomal miRNA levels in COLO320 and COLO741 colon cancer cell lines. Methods The MTT method was used for cell growth and cytotoxicity in both COLO320 and COLO741 cell lines. Dicer, Ago2, eIF2α, CD-9, and CD-63 antibodies were used for the immunocytochemical evaluation. Total miRNA analysis was performed using a miRCURY Exosome Isolation Kit. Results As a result of immunocytochemical staining, increased CD-63 immunoreactivity was observed in RSV-treated COLO320 cells vs. RSV-treated COLO-741 cells. Dicer immunoreactivity increased after the RSV treatment in COLO320 cells. Higher eIF2α immunoreactivity was observed in RSV-treated COLO741 cells compared to both COLO741 control cells and RSV-treated COLO320 cells. Non-significant decreases were observed in miRNA concentration in RSV-treated COLO320 and COLO741 cells compared to control group cells. Conclusions RSV could increase miRNA biogenesis in COLO320 cancer cells and decrease it in COLO741 cancer cells.

A comprehensive proteomic profiling of urinary exosomes and the identification of early non-invasive biomarker in patients with coronary artery disease

Urinary small extracellular vesicles or exosomes (uEVs) source could be an emerging trove of biomarkers in coronary artery disease (CAD). It is a chronic inflammatory disease having a long asymptomatic phase of fatty-fibrous development in arteries leading to angina, myocardial infarction, and death. Our study was aimed at identifying differential protein expression profiling of uEVs in CAD. We collected urine samples of CAD patients (n = 41) age 18–65 years and gender matched healthy controls (n = 41). We isolated uEVs using differential ultracentrifugation. Further, uEV samples were characterized by western blotting exosome markers (Flotillin, TSG, CD63, and CD9), nano tracking analysis, and transmission and scanning electron microscopy. A total of 508 proteins were identified by iTRAQ-based mass spectrometry. We observed protein expression levels of AZGP1, SEMG1/2, ORM1, IGL, SERPINA5, HSPG2, prosaposin, gelsolin, and CD59 were upregulated, and UMOD, KNG1, AMBP, prothrombin, and TF were downregulated. Protein-protein interactions, gene ontology and pathway analysis were performed to functionally annotate identified uEVs proteins. A novel uEVs differential protein signature is shown. On validating UMOD protein by ELISA in two clinically different CAD, stable-CAD patients had lower levels than healthy controls whereas recent myocardial infarction patients had lowest. Our findings suggest UMOD importance as early diagnostic biomarker. SignificanceCoronary artery disease is a chronic inflammatory disease caused by gradual deposition of cholesterol and fat along with other proteins to develop plaque inside arteries. This further leads to blockage of artery, heart attack and death. There are no identifiable early biomarkers to diagnose this. For the first time, we have identified the differentially expressed proteins isolated from non-invasive uEV of CAD patients compared to healthy controls by using MS Orbitrap and iTRAQ labelling of peptides. We have identified decreased levels of UMOD protein in CAD. These findings have been confirmed by ELISA. Furthermore, the levels of UMOD were observed as more highly decreased in recent myocardial infarction CAD patients, indicating the importance of this protein as an early diagnostic biomarker. Conclusively, our study represents a non-invasive urinary EVs trove of differentially expressed proteins in CAD. This will form a groundwork for understanding the pathophysiology of CAD and will help in future translational research utilizing uEVs.

Metabolic signatures of tear extracellular vesicles caused by herpes simplex keratitis

PurposeHerpes simplex keratitis (HSK), caused by type 1 herpes simplex virus (HSV) reactivation, is a severe infectious disease that leads to vision loss. HSV can trigger metabolic reprogramming in the host cell and change the extracellular vesicles (EV) cargos; however, little is known about the EV metabolic signatures during ocular HSV infection. Here, we aimed to depict the EV-associated metabolic landscape in HSK patients’ tears. MethodsWe collected 82 samples from 41 participants with unilateral HSK (contralateral unaffected tears were set as negative control), including subtype cohorts of 13 epithelial, 20 stromal, and 8 endothelial HSK. We isolated tear EVs via our previously established platform and conducted metabolic analysis using LC-MS/MS. The metabolic signatures for recognizing HSK and subtypes were assessed through differential analysis and machine learning algorithms. ResultsHypopsia and increased extracellular CD63 levels were observed in affected eyes. We identified 339 metabolites based on sEVs isolated from tears. Differential analysis revealed alterations in energy and amino acid metabolism, as well as the infectious microenvironment. Furthermore, we observed dysregulated metabolite such as methyldopa, which is associated with inappropriate neovascularization and corneal sensation loss, contributing to the HSK severity particularly in the stromal subtype. Moreover, machine learning classification also suggested a set of EV metabolic signatures that have potential for pan-keratitis detection. ConclusionsOur findings demonstrate that tear EV metabolites can serve as valuable indicators for comprehending the underlying pathological mechanisms. This knowledge is expected to facilitate the development of liquid biopsy means and therapeutic target discovery.

Integrin α2 promotes immune escape in non-small-cell lung cancer by enhancing PD-L1 expression in exosomes to inhibit CD8 + T-cell activity.

This study intended to delineate the mechanism and functional role of integrin α2 (ITGA2) in non-small-cell lung cancer (NSCLC) cell immune escape. Bioinformatics analysis was utilized to analyze ITGA2 expression in NSCLC tissues, and correlations between ITGA2 expression and patient survival time, ITGA2 expression and programmed cell death ligand 1 (PD-L1; CD274) expression, and ITGA2 expression and CD8+ T-cell infiltration. Quantitative real-time polymerase chain reaction detected ITGA2 expression. Transmission electron microscopy was applied to examine the morphology of exosomes, and western blot measured CD9, CD63, and PD-L1 levels. CCK-8 measured cell viability. Cell toxicity experiment measured the killing effect of CD8+ T cells on cancer cells. Enzyme-linked immunosorbent assay assessed secretion levels of interleukin-2, interferon-gamma, tumor necrosis factor-alpha, and PD-L1 expression in exosomes. Immunohistochemistry detected ITGA2, CD8, and PD-L1 expression in patient tissue samples. ITGA2 was highly expressed in NSCLC, and Pearson correlation analysis showed a negative correlation of ITGA2 with CD8+ T-cell infiltration and a positive correlation of ITGA2 with PD-L1 expression. Cell experiments showed that silencing ITGA2 hindered NSCLC cell progression and increased levels of CD8+ T-cell secretory factors. Further mechanism studies found that ITGA2 reduced CD8+ T-cell-mediated antitumor immunity via the increase in PD-L1 expression. Clinical sample testing unveiled that ITGA2 was upregulated in NSCLC tissues. PD-L1 upregulation was seen in exosomes separated from patient blood, and correlation analysis showed a positive correlation of exosomal PD-L1 expression in blood with ITGA2 expression in tissues. This study displays a novel mechanism and role of ITGA2 in NSCLC immune escape, providing directions for the clinical therapy of NSCLC patients.

The role and mechanism of HIF-1α-mediated glypican-3 secretion in hypoxia-induced tumor progression in hepatocellular carcinoma

ObjectiveTo explore the expression and secretion mechanism of glypican-3 (GPC3) in hepatocellular carcinoma (HCC) cells under hypoxic conditions, and its role in tumor progression. MethodsHuh7 cells with and without the knockdown of hypoxia-inducible factor 1-alpha (HIF-1α) were cultured under 1% O2 for varying durations to induce hypoxia. The expression levels of GPC3, HSP70, CD63, STX11 and SYT7 in the cytoplasm and exosomes of Huh7 cells were evaluated by western blotting and immunofluorescence. GPC3 protein expression was further measured in cells treated with GW4869 under hypoxic conditions. Huh7 cells and human umbilical vein endothelial cells (HUVECs) were cultured with the exosomes extracted from the control and GPC3-knockdown cells, the cell proliferation, migration, epithelial-mesenchymal transition (EMT), invasion, and in vitro angiogenesis were analyzed. Tumor xenografts were established to assess the role of GPC3-deficient exosomes in tumor growth. ResultsHypoxic culture conditions downregulated GPC3, STX11 and SYT7 protein levels in the Huh7 cells and upregulated GPC3 mRNA, and also increased GPC3 protein expression in the exosomes. HIF-1α knockdown, as well as treatment with GW4869, upregulated GPC3 protein in the Huh7 cells grown under 1% O2, but downregulated exosomal GPC3. Furthermore, exosomes derived from the GPC3-knockdown cells inhibited the proliferation and migration of Huh7 cells, decreased the expression of N-cadherin, vimentin, β-catenin, c-Myc and cyclin D1, and increased that of E-cadherin. Likewise, the GPC3-deficient exosomes also suppressed the invasion and tube formation ability of the HUVECs compared to that of control cells. Consistent with the in vitro results, the GPC3-deficient exosomes also repressed tumor growth in vivo. ConclusionHypoxia promoted secretion of exosomal GPC3 through the activation of HIF-1α. GPC3-deficient exosomes inhibited the proliferation, migration and EMT of HCC cells via the Wnt/β-catenin signaling pathway, and suppressed the angiogenic potential of HUVECs. This provided a novel understanding of the role of exosomal GPC3 in HCC progression.

Exosome-delivered circRNA circSYT15 contributes to cisplatin resistance in cervical cancer cells through the miR-503-5p/RSF1 axis

ABSTRACT The development of chemotherapy resistance is a major obstacle for cervical cancer (CC) patients. Exosome-mediated transfer of circular RNAs (circRNAs) was found to have relevance to the CC. This study is designed to explore the role and mechanism of exosomal circRNA synaptotagmin 15 (circSYT15) on cisplatin (DDP) resistance in CC. Cell proliferation ability and apoptosis rate were detected by Cell Counting Kit-8 (CCK-8), 5-ethynyl-2’-deoxyuridine (EdU), colony formation, and flow cytometry assays. CircSYT15, microRNA-503-5p (miR-503-5p), Remodeling spacing factor 1 (RSF1) levels were detected by real-time quantitative polymerase chain reaction (RT-qPCR). Exosomes were analyzed by a transmission electron microscope and nanoparticle tracking analysis. CD63, CD81, TSC101, Bcl-2, Bax, C-caspase 3, and RSF1 protein levels were examined by western blot assay. The binding between miR-503-5p and circSYT15 or RSF1 was predicted by circBank or Starbase and then verified by a dual-luciferase reporter and RNA Immunoprecipitation (RIP). The biological role of exosomal circSYT15 in DDP resistance of CC in vivo. CircSYT15 was upregulated in the DDP-resistant CC cells and exosomes isolated from DDP-resistant CC cells. CircSYT15 knockdown repressed the proliferation and drug resistance of CC and induced apoptosis in CC cells. Exosomes shuttled circSYT15 act as a sponge to affect RSF1 expression, thereby promoting proliferation and drug resistance and repressing apoptosis of sensitive CC cells. Exosomal circSYT15 boost DDP resistance of cervical cancer in vivo. Exosome-mediated transfer of circSYT15 enhanced DDP resistance in CC partly by targeting the miR-503-5p/RSF1 axis, providing a foundation for future clinical applications of CC drug resistance.

New iron export pathways acting via holo-ferritin secretion

Ferritin is a spherical nanocage protein for iron storage, composed of 24 light- or heavy-polypeptide chain subunits. A single ferritin molecule can carry up to 4500 iron atoms in its core, which plays an important role in suppressing intracellular iron toxicity. Serum ferritin levels are used as a marker for the total amount of iron stored in the body. Most serum ferritin is iron-free (apo-ferritin) and it is unclear how ferritin is released from cells. Ferritin is secreted into serum via extracellular vesicles (EVs) or the secretory autophagy pathway but not via the classical endoplasmic reticulum (ER)-to-Golgi secretion pathway. We recently discovered that the level of tetraspanin CD63, a common EV marker, is post-transcriptionally regulated by the intracellular iron level and both CD63 and ferritin expression is induced by iron loading. Ferritin is incorporated into CD63(+)-EVs through the ferritin-specific autophagy adapter molecule, NCOA4, and then secreted from cells. EV production differs drastically depending on cell type and physiological conditions. Extracellular matrix detached cells express pentaspanin prominin 2 and prominin 2(+)-EVs secrete ferritin independently of NCOA4 trafficking. Ferritin is tightly bound to iron in EVs and functions as an iron-carrier protein in the extracellular environment. Cells can suppress ferroptosis by secreting holo-ferritin, which reduces intracellular iron concentration. However, this exposes the neighboring cells receiving the secreted holo-ferritin to a large excess of iron. This results in cellular toxicity through increased generation of reactive oxygen species (ROS). Here we review the machinery by which ferritin is incorporated into EVs and its role as an intercellular communication molecule.

Identifying Treatment Resistance Related Pathways by Analyzing Serum Extracellular Vesicles of Patients With Resistant Versus Regressed Retinoblastoma.

To identify the genes and pathways responsible for treatment resistance (TR) in retinoblastoma (RB) by analyzing serum small extracellular vesicles (sEVs) of patients with TR active RB (TR-RB) and completely regressed RB (CR-RB). Serum-derived sEVs were characterized by transmission electron microscopy and nanoparticle tracking analysis. sEV transcriptome profiles of two TR-RB and one CR-RB with good response (>20 years tumor free) were compared to their age-matched controls (n = 3). Gene expression data were analyzed by the R Bioconductor package. The CD9 protein and mRNA expression of CD9, CD63, and CD81 were studied in five RB tumors and two control retinae by immunohistochemistry and quantitative reverse transcription-polymerase chain reaction. The isolated serum sEVs were round shaped and within the expected size (30-150 nm), and they had zeta potentials ranging from -10.8 to 15.9 mV. The mean ± SD concentrations of sEVs for two adults and four children were 1.1 × 1012 ± 0.1 and 5.8 × 1011 ± 1.7 particles/mL. Based on log2 fold change of ±2 and P < 0.05 criteria, there were 492 dysregulated genes in TR-RB and 184 in CR-RB. KAT2B, VWA1, CX3CL1, MLYCD, NR2F2, USP46-AS1, miR6724-4, and LINC01257 genes were specifically dysregulated in TR-RB. Negative regulation of apoptotic signaling, cell growth, and proton transport genes were greater than fivefold expressed only in TR-RB. CD9, CD63, and CD81 mRNA levels were high in RB tumors versus control retina, with increased and variable CD9 immunoreactivity in the invasive areas of the tumor. Serum sEVs could serve as a potential liquid biopsy source for understanding TR mechanisms in RB.

Higher House Dust Mite-Specific IgE Levels among Chronic Spontaneous Urticaria Patients May Implicate Higher Basophil Reactivity

Introduction: Allergen-specific IgE (sIgE) sensitization exists in a considerable fraction of chronic spontaneous urticaria (CSU) patients. Basophils have been implicated in the pathogenesis of CSU. This paper aimed to explore the relationship between allergic sensitization and basophil reactivity in CSU and the possible underlying mechanism. Methods: Basophil-enriched leukocytes were isolated from the peripheral blood of 76 CSU patients and 9 healthy controls. Basophil CD63 and FcεRIα (the alpha subunit of the high-affinity IgE receptor) expression in the blood samples with various house dust mite (HDM)-sIgE levels were determined by flow cytometry. Basophil reactivity and SHIP-1 (a molecule related to the IgE/FcεRI signaling pathway) expression were analyzed after stimulation with an HDM allergen or other stimuli. Results: HDM-sIgEstrong positive (≥3.5 kU/L) CSU patients had a significantly higher mean percentage of basophil CD63 and higher baseline levels of FcεRIα expressed by basophils than HDM-sIgEnormal (<0.35 kU/L) CSU patients and healthy controls; the same went for total serum IgE. After stimulation with Dermatophagoides pteronyssinus peptidase 1 (Derp1) alone or together with Derp1-sIgE, the stimulation index of CD63 and levels of FcεRIα expressed by basophils in HDM-sIgEstrong positive CSU patients were significantly higher than those in HDM-sIgEnormal CSU patients and healthy controls. Significantly more SHIP-1 mRNA expression in HDM-sIgEstrong positive CSU patients was induced after the combined stimulation in comparison to other subjects. Conclusion: CSU patients with higher HDM-sIgE levels (≥3.5 kU/L) may have higher CD63 and FcεRIα expression on peripheral blood basophils. Peripheral blood basophils in these CSU patients are more responsive to HDM allergen stimulation. Higher HDM-sIgE levels among CSU patients may implicate higher basophil reactivity.

Tetraspanin CD63 reduces the progression and metastasis of head and neck squamous cell carcinoma via KRT1-mediated cell cycle arrest

Despite the fact that metastasis is the leading cause of death in patients with head and neck squamous cell carcinoma, fundamental questions about the mechanisms that enable or inhibit metastasis remain unanswered. Tetraspanin CD63 has been linked to tumor progression and metastasis. However, few studies have examined the role of CD63 in HNSCC. In this study, we discovered that CD63 levels were abnormally altered in HNSCC tissue compared to adjacent tissue (n = 69 pairs), and that this was linked to prognosis. Through functional in vitro and in vivo experiments, the roles of CD63 in HNSCC were confirmed. Overexpression of CD63 inhibited the progression and metastasis of HNSCC cells. Using mass spectrometry and co-immunoprecipitation assays, we discovered that KRT1 could be a direct interacting partner of CD63. Furthermore, both CD63 and KRT1 expression was significantly decreased in metastatic tissue compared with primary tumor tissue (n = 13 pairs), suggesting that CD63 and KRT1 play a role in reducing the metastasis of HNSCC. In summary, we reveal a previously unrecognized role of CD63 in regulating KRT1-mediated cell cycle arrest in HNSCC cells, and our findings contribute to defining an important mechanism of HNSCC progression and metastasis.