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At least 19 recordsLinked to original sources

PubMed2026

Functional and Proteomic Profiles of CD3(+) Plasma-Derived Small Extracellular Vesicles Differentiate Cancer Patients From Healthy Donors.

Small extracellular vesicles (sEV) released by T cells play a key role in immune regulation. Immune capture with anti-CD3 antibodies was used to isolate and study T cell-derived CD3(+)sEV from the plasma of patients with melanoma (MPs) or healthy donors (HDs). Functional responses induced in recipient target cells by CD3(+)sEV of MPs differed from responses induced by CD3(+)sEV of HDs. Approximating functions mediated by melanoma cell-derived sEV (MTEX), CD3(+)sEV of MPs reduced metabolic activity and proliferation of T cells while promoting activity in Mel526 cell targets. Proteomics profiling confirmed functional differences between CD3(+)sEV of MPs and HDs. Of 294 sEV-specific proteins identified in CD3(+)sEV, 226 were detected in the parent T cell proteome, confirming that the CD3(+)sEV proteome mimics that of the parent T lymphocytes. Among them were 66 differentially expressed proteins (DEPs) that differentiated vesicles from MPs and HDs. These DEPs were associated with processes linked to cancer-related functions. DEPs upregulated in CD3(+)sEV of MPs were associated with RHO-GTPase, cytokine, and MAPK signaling pathways. Thus, T cells of MPs were reprogrammed by MTEX to produce CD3(+)sEV that functionally resembled MTEX, partly recapitulated features of the tumor proteome, and differed from CD3(+)sEV of HDs. In cancer, the TEX-rewired T cells produce CD3(+)sEV that potentially could serve as a liquid biopsy of patients' T cells.

Humans↗

PubMed2024

Proteomic profiles of peritoneal fluid-derived small extracellular vesicles correlate with patient outcome in ovarian cancer.

Cancer-derived small extracellular vesicles (sEVs) are capable of modifying the tumor microenvironment and promoting tumor progression. Ovarian cancer (OvCa) is a lethal malignancy that preferentially spreads through the abdominal cavity. Thus, the secretion of such vesicles into the peritoneal fluid could be a determinant factor in the dissemination and behavior of this disease. We designed a prospective observational study to assess the impact of peritoneal fluid-derived sEVs (PFD-sEVs) in OvCa clinical outcome. For this purpose, 2 patient cohorts were enrolled: patients with OvCa who underwent a diagnostic or cytoreductive surgery and nononcological patients, who underwent abdominal surgery for benign gynecological conditions and acted as the control group. Systematic extraction of PFD-sEVs from surgical samples enabled us to observe significant quantitative and qualitative differences associated with cancer diagnosis, disease stage, and platinum chemosensitivity. Proteomic profiling of PFD-sEVs led to the identification of molecular pathways and proteins of interest and to the biological validation of S100A4 and STX5. In addition, unsupervised analysis of PFD-sEV proteomic profiles in high-grade serous ovarian carcinomas (HGSOCs) revealed 2 clusters with different outcomes in terms of overall survival. In conclusion, comprehensive characterization of PFD-sEV content provided a prognostic value with potential implications in HGSOC clinical management.

Humans↗

PubMed2025

MicroRNAs signatures in small extracellular vesicles for psychological resilience in young adults using machine learning.

AIMS: Psychological resilience refers to an individual's capacity to adapt to adverse events. MicroRNAs (miRNAs) play a crucial role in regulating post-transcriptional processes, while small extracellular vesicles (sEVs) act as transport vehicles. This study aimed to employ genome-wide profiling to identify and validate differences in the expression of resilience-associated sEV-miRNAs between low resilience (LR) and high resilience (HR) in young adults. METHODS: Eighty participants were divided into LR or HR based on the Connor - Davidson Resilience Scale (CD-RISC). The expression levels of the target sEV-miRNAs in LR and HR were compared and analyzed. RESULTS: Expression analyses demonstrated significant differences in let-7b, miR-151b, miR-335, and miR-193a between LR and HR (p < 0.01), with let-7b showing the highest discriminative ability. The AUC values for each sEV-miRNA ranged from 0.74 to 0.94, based on logistic regression and three machine learning models: random forest, support vector machine, and eXtreme gradient boosting. Based on leave-one-out cross-validation in different models, the combined four sEV-miRNAs demonstrated strong performance for detecting LR (AUC = 0.87-0.90). Sex-specific differences were also observed, with female participants showing more pronounced resilience signatures in targeted sEV-miRNAs. CONCLUSIONS: These findings suggest that sEV-miRNAs hold potential as biomarkers for psychological resilience in young adults.

Humans↗

PubMed2026

Small extracellular vesicles reflect senescence progression in human bone marrow-derived mesenchymal stem cells during hollow fiber bioreactor culture.

Prolonged three-dimensional culture exposes stem cells to sustain microenvironmental and mechanical stresses that can promote aging- and senescence-associated phenotypic alterations. This study examined how long-term expansion of human bone marrow-derived mesenchymal stem cells (BMSCs) in a hollow fiber bioreactor (HFB) influences cellular senescence and the molecular composition of secreted small extracellular vesicles (sEVs). During extended HFB culture, BMSCs exhibited progressive morphological flattening and cytoskeletal disorganization, accompanied by increased senescence-associated β-galactosidase activity and immunophenotypic remodeling characterized by reduced fluorescence intensity and spatial redistribution of canonical MSC markers, consistent with a stress-adapted, early senescence-associated cellular state. In parallel, sEVs were collected longitudinally over 40 days and characterized by nanoparticle tracking analysis, immunoblotting, and quantitative proteomics. While vesicle size, marker expression, and yield remained stable throughout culture, proteomic profiling revealed pronounced, phase-dependent remodeling of sEV cargo, including coordinated alterations in oxidative stress-related processes, lysosomal and extracellular matrix-associated pathways, and relative depletion of cytoskeletal and translational components. Notably, these vesicular signatures closely mirrored senescence-associated changes observed at the cellular level. The strong correspondence between cellular phenotypes and sEV proteomic profiles establishes vesicle analysis as a convergent and noninvasive readout of BMSC aging, enabling sensitive monitoring of senescence progression while reducing reliance on parallel, labor-intensive cellular assays. Collectively, these findings indicate that prolonged HFB culture promotes a controlled, stress-associated senescence program in BMSCs and position sEV proteomic profiling as a robust approach for assessing stem cell aging dynamics during long-term three-dimensional bioreactor culture.

Mesenchymal Stem Cells↗

PubMed2026

Novel serum small extracellular vesicle miRNAs with multi-target RCA-CRISPR sensor for liver cancer detection.

BACKGROUND: Detecting liver cancer (LC) remains a significant challenge in clinical practice. Small extracellular vesicle (sEV) miRNAs show promise as non-invasive biomarkers for LC detection, yet their diagnostic potential remains largely unexplored. This study aimed to identify specific sEV miRNA signatures for LC detection and develop a novel synchronized multi-miRNA detection platform to enhance diagnostic efficiency and sensitivity. METHODS: High-throughput sequencing was conducted across four distinct cohorts: normal controls (NC), hepatitis B virus (HBV) patients, liver cirrhosis patients, and LC patients. This sequencing process identified miRNAs with differential expression, followed by RT-qPCR validation in serum sEV miRNAs from LC patients and NC. An innovative detection method, RCA-CRISPR, was introduced, combining rolling circle amplification (RCA) with CRISPR/Cas12a (RCA-CRISPR) for quick and sensitive miRNAs detection. RESULTS: Sequencing results showed a consistent elevation of hsa-miR-203b-5p, hsa-miR-4661-5p, and hsa-miR-219a-2-3p across all cohorts. RT-qPCR validations confirmed significant upregulation of these miRNAs in serum sEVs from LC patients, and the combined three-miRNA panel exhibited high diagnostic accuracy (p = 0.0003; AUC = 0.81). The RCA-CRISPR method demonstrated a detection limit of 3.12 pM for simultaneous multi-target miRNA detection, highlighting its exceptional sensitivity. CONCLUSIONS: Our study identifies hsa-miR-203b-5p, hsa-miR-4661-5p, and hsa-miR-219a-2-3p as promising sEV miRNA biomarkers for LC detection. The developed RCA-CRISPR sensor provides a robust tool for multi-miRNA analysis, potentially advancing non-invasive LC diagnostics. Future validation in larger, prospectively collected cohorts is essential to establish the clinical utility and performance of this biomarker panel and RCA-CRISPR sensor.

MicroRNAs↗

PubMed2026

Urinary Small Extracellular Vesicle DNA as a Biomarker for the Non-Invasive Diagnosis of Bladder Cancer.

Existing diagnostic technologies for bladder cancer (BC) suffer from low sensitivity, low specificity, or a lack of validation. Therefore, validated, non-invasive diagnostic biomarkers with high sensitivity and specificity for early detection of BC are needed to complement and improve upon the limitations of existing diagnostic methods. We used low-pass whole genome sequencing (LP-WGS) technology to detect copy number variations (CNVs) in small extracellular vesicle (sEV) DNA isolated from urine samples of patients. Based on these results, we constructed and validated a diagnostic model to differentiate between benign and malignant bladder lesions. We conducted a receiver operating characteristic analysis and calculated the area under the curve (AUC) to evaluate the performance of the diagnostic model. The urine sEV-DNA LP-WGS data revealed CNV differences between benign and malignant samples. The diagnostic model achieved an AUC of 0.953, a sensitivity of 86.7%, and a specificity of 100% in the training cohort and an AUC of 0.985, a sensitivity of 90%, and a specificity of 100% in the validation cohort. Even at the lowest coverage depth of 0.01X, the performance of the diagnostic model remained relatively robust. Notably, the performance of this diagnostic model surpassed that of the biomarker neuron-specific enolase (sensitivity: 85.7% vs. 64.3%; specificity: 100% vs. 87.5%) and urinary cytology (sensitivity: 100% vs. 66.7%; specificity: 100% vs. 94.1%). Our study demonstrates that urine sEV-DNA exhibits high discriminatory power in distinguishing between benign and malignant bladder lesions, making it a promising tool for auxiliary diagnosis of BC.

Humans↗

PubMed2026

Small extracellular vesicles are the key players in ochratoxin A-induced kidney toxicity.

BACKGROUND: Despite growing evidence of ochratoxin A (OTA)-induced kidney toxicity, the underlying mechanisms remain elusive. Emerging evidence suggests that small extracellular vesicles (sEVs) act as mediators of intercellular communication to recipient cells during various physiological and pathological conditions. Given the distinctive properties of sEVs, it is hypothesized that OTA-induced sEVs might mediate the OTA-induced kidney pathogenesis. METHODS: To explore the involvement of sEVs in OTA-induced kidney toxicity, sEVs were isolated and characterized from OTA-exposed rat kidney epithelial cells (NRK52E). Later, these sEVs were used to treat NRK52E cells and Wistar rats to assess the impact of OTA-induced sEVs on kidney toxicity. Label-free proteomics was also performed on OTA-induced sEVs, and key proteins were identified and validated. The biodistribution of sEVs in rats was also assessed using live imaging. The role of validated protein/s in kidney toxicity was further confirmed via a gene silencing and overexpression study. RESULTS: OTA exposure increased sEV secretion into conditioned media of NRK52E cells and into the urine of Wistar rats. Interestingly, we found that OTA-induced sEVs cause similar kidney toxicity in vitro and in vivo systems as OTA exposure, and blocking of sEV secretion markedly alleviated OTA-mediated kidney toxicity. Proteomics analysis identified annexin A2 and fibrinogen-ɣ as common proteins detected in sEVs derived from OTA-exposed NRK52E cells or rat urine. However, immunoblotting validated that annexin A2 was the only sEV-associated protein, expressed significantly in both NRK52E and rat urine following OTA exposure. Notably, silencing of annexin A2 attenuated the ability of OTA-induced sEVs to cause kidney toxicity, whereas overexpression exacerbates it. CONCLUSIONS: Our findings identify the annexin A2-enriched sEVs as key mediators of OTA-induced kidney toxicity. Annexin A2, along with other kidney injury markers, offers a promising non-invasive translational biomarker for early detection and monitoring of OTA-induced kidney toxicity.

Ochratoxins↗

PubMed2026

Protocol for the isolation and characterization of extracellular vesicles and particles from human and murine cell lines.

Cells produce a heterogeneous population of extracellular vesicles and particles (EVPs). Small extracellular vesicles (sEVs or exosomes) are lipid membrane-enclosed vesicles with sizes ranging from 30 to 150 nm. Here, we present a protocol to isolate and characterize EVPs from the conditioned medium of cell lines. We describe steps for cell culture, conditioned media collection, differential ultracentrifugation, and EVP characterization. We then detail procedures for proteomic and biodistribution analyses. For complete details on the use and execution of this protocol, please refer to Yeung et al.1.

Animals↗

PubMed2025

Identification of molecular markers and exploration of the oncogenic role of exomeres in hepatocellular carcinoma.

Extracellular vesicles and particles (EVPs) serve as functional mediators delivering their cargoes to specific destinations. Exomeres (EMs) represent a newly discovered subset of nanoparticles, with limited understanding of their biophysical characteristics and functionalities. Here, we isolated and studied EMs from different normal and cancer cell lines. Proteomic analysis reveals distinctive features of EMs compared to small extracellular vesicles (sEVs) and identifies galactosamine (N-acetyl)-6-sulfatase (GALNS) and mannosidase alpha class 2B member 1 (MAN2B1) to be expressed in EMs, indicating their potential as specific EM molecular markers. Subsequent investigations into tumor-derived EMs demonstrate their oncogenic properties to support cancer growth and metastasis. Furthermore, analysis of murine hepatocellular carcinoma-derived EM reveals their ability to induce cell cycle progression and metabolic alterations. Collectively, our data highlight the distinct nature of EMs as a nanoparticle subpopulation different from sEVs, with cancer-derived EMs significantly contributing to tumor growth and dissemination.

Carcinoma, Hepatocellular↗

PubMed2025

A comprehensive analysis of supermere, exomere, and extracellular vesicle isolation and cargo in colorectal cancer.

Biofluids contain a heterogeneous mixture of extracellular vesicles and non-vesicular nanoparticles (including exomeres and supermeres) that transport a diverse array of proteins, RNA, and lipids. Our previous efforts to characterize the contents of these carriers in colorectal cancer relied on 2D culture systems requiring large-scale setups and time-consuming ultracentrifugation-based isolation. To streamline this process, we have combined 3D hollow-fiber bioreactor production and fast-protein liquid chromatography-based size-exclusion chromatography. Here, we compare the impact of culture methods and purification strategies on small extracellular vesicle, exomere, and supermere cargo. Proteomic analyses show consistently distinct profiles for extracellular vesicles, exomeres, and supermeres regardless of culture conditions or isolation method. In contrast, these two variables influence small RNAs, their base modifications, and lipidomic profiles. We present an online tool to query these and future secretome datasets (https://superomics.shinyapps.io/browse).

Humans↗

PubMed1983

Matrix vesicles in atherosclerotic calcification.

Matrix vesicles, small extracellular membranous structures, are known to be the initial loci of calcification of cartilage, bone, and dentin. Calcification is an important complication of atherosclerosis. Using histologic, ultrastructural, and cytochemical techniques, the present study has demonstrated that matrix vesicle-like structures are involved in the calcification of atherosclerotic lesions, as well as in arterial medial calcification. In aortas from autopsied humans and from rabbits and chickens on atherogenic diets, the matrix vesicles appear to be derived from intimal and medial cellular components, mainly smooth muscle cells.

Animals↗

PubMed2025

Effect of extracellular vesicles in remodeling the tumor microenvironment by DNMT1 downregulation for enhanced cancer immunotherapy.

BACKGROUND: The efficacy of immunotherapy is often hindered by the suppression of immune responses via the tumor microenvironment (TME). The presence of cancer cells forces other proximal non-cancerous cells to support tumor growth and persistence. A clear example of this cancerous-to-non-cancerous communication is represented by the accumulation of myeloid-derived suppressor cells (MDSCs) within the TME. Several studies have convergently shown that the overexpression of DNA-methyl-transferase-1 (DNMT1) in these cells results in protection from necroptosis and enhanced accumulation in vivo. Conversely, targeting DNMT1 through hypo-methylating agents has shown promising therapeutic potential by not only reducing the levels of MDSCs but also enhancing cancer immunogenicity and the efficacy of immune checkpoint inhibitors (ICI). METHODS: Murine 4T1 (triple-negative breast cancer (TNBC)) and CT26 (colon carcinoma) cell lines were cultured under standard conditions and used to generate tumor models in BALB/c mice. An oncolytic adenovirus expressing a DNMT1-targeting short hairpin RNA (OAd.shDNMT1) was engineered and validated for DNMT1 knockdown and genome-wide methylation reduction. Small extracellular vesicles (sEVs) were isolated from virus-infected cancer cells and characterized for RNA content and uptake by MDSCs. MDSC differentiation and suppressive function were assessed in vitro using flow cytometry and co-culture assays with murine splenocytes. In vivo, tumor-bearing mice received intratumoral OAd.shDNMT1, systemic decitabine, or immune checkpoint inhibitors (anti-Programmed cell Death protein-1), and tumor growth, immune infiltration, and systemic MDSC levels were evaluated. RESULTS: In this study, we report that, by using virally infected TNBC murine cells as a source for shDNMT1-loaded sEVs, OAd.shDNMT1 successfully reduced MDSC levels in vitro and in vivo. Furthermore, the co-administration with ICI resulted in a significant tumor growth reduction in mice bearing poorly immunogenic TNBC 4T1 cells. Also, our treatment promoted antitumor immunity, prolonged survival, and complete tumor eradication in modestly immunogenic colon CT26 cancer cells. CONCLUSION: This multifaceted strategy, based on OV-mediated immune stimulation and reduction of MDSC levels via sEVs, may improve clinical outcomes and the success of immuno-based regimens for patients facing MDSC-rich and highly aggressive cancer subtypes.

Animals↗

PubMed1991

Pilocarpine elicits the interdental cell secretory activity of the inner ear.

Subcutaneous injection of pilocarpine in guinea pigs resulted in the following ultrastructural changes: 1) the apical cavities of the interdental cells were filled with a substance indistinguishable from the overlying amorphous layer of the TM; 2) a great number of spherical structures appeared over the limbal portion of the tectorial membrane. In TEM photomicrographs these structures displayed the same appearance as the amorphous layer of the TM and were usually continuous to it; 3) the number of holes that decorate the upper surface of the limbal portion of the TM was dramatically increased and it was found that they connect the endolymphatic space to the apical cavities of the interdental cells; 4) there was an increase in the number of the small extracellular vesicles found in the clear spaces of the tectorial membrane. These facts suggest that pilocarpine stimulates the secretion of the interdental cells, confirming the existence of the secretory processes previously described (Prieto et al., 1990). These findings can be related to the turnover of the TM in the adult animal and, perhaps, to the secretion of some organic compound to the endolymph. We postulate that the actions of pilocarpine on the interdental cells are most probably mediated by the activation of muscarinic acetylcholine receptors in these cells.

Animals↗

PubMed2025

High-Frequency Irreversible Electroporation Alters Proteomic Profiles and Tropism of Small Tumor-Derived Extracellular Vesicles to Promote Immune Cell Infiltration.

High-frequency irreversible electroporation (H-FIRE) is a nonthermal tumor ablation technique that disrupts the blood-brain barrier (BBB) in a focal and reversible manner. However, the mechanisms underlying this disruption remain poorly understood, particularly the role of small tumor-derived extracellular vesicles (sTDEVs) released from ablated tumor cells. In this study, we investigate the proteomic and functional alterations of sTDEVs released from F98 glioma and LL/2 Lewis lung carcinoma cells following H-FIRE ablation. Mass spectrometry analysis revealed 108 unique proteins in sTDEVs derived from ablative doses of H-FIRE, which are capable of disrupting the BBB in an in vitro model. Proteomic analysis of TDEVs highlights key changes in pathways related to integrin signaling, Platelet-derived growth factor receptor (PDGFR) signaling, and ubiquitination, which may underline their interactions with brain endothelial cells. These "disruptive" sTDEVs exhibit enhanced tropism for cerebral endothelial cells both in vitro and in vivo, where they persist in the brain longer than sTDEVs released after non-ablative H-FIRE doses. Notably, when introduced into a healthy Fischer rat model, disruptive sTDEVs are associated with increased recruitment of Iba1+ immune cells, suggesting a potential role in modulating post-ablation immune responses. However, despite their altered protein composition, these vesicles do not directly increase BBB permeability in vivo. This study is the first to demonstrate that electroporation-based tumor ablation significantly alters the composition and functionality of tumor-derived extracellular vesicles, potentially influencing the tumor microenvironment post-ablation. These findings have important implications for developing multimodal treatment strategies that combine H-FIRE with systemic therapies to enhance efficacy while managing the peritumoral microenvironment.

Animals↗

PubMed1986

Calcification in atherosclerosis. II. Animal studies.

For comparison with our previous study on early calcification in human atherosclerosis, the aortas of rabbits and chickens with experimentally induced atherosclerosis were studied by gross examination, light microscopy and electron microscopy, including various cytochemical techniques. Nine male New Zealand white rabbits and nine male white leghorn chickens were fed an atherogenic diet of chow with 8% peanut oil and 2% cholesterol for one, two or three months. Six rabbits and six chickens, fed normal chow for one, two or three months, served as controls. The normal diet chickens were found to have lipid-negative spontaneous fibrous plaques in the abdominal aorta, which following atherogenic diet developed lipid deposition and increasing calcium deposition. The normal diet rabbits had no aortic lesions, but following an atherogenic diet developed highly lipid-positive foam cell intimal lesions which subsequently developed increasing amounts of smooth muscle cells and calcium. Ultrastructurally, the aortic plaques in normal diet chickens were composed of smooth muscle cells, collagen, elastic fibers, ground substance and a few small extracellular matrix vesicles bounded by a trilaminar membrane. In the atherogenic diet chickens, these vesicles increased in number as did their staining for calcium by the pyroantimonate technique. The membranes of vesicles were cytochemically positive for alkaline phosphatase and adenosine triphosphatase. Similar matrix vesicles were present in the interstitium of the media. In both intima and media, the vesicles appeared to be largely derived from degenerating smooth muscle cells. The aortas of atherogenic diet rabbits were similar to the chickens except for many more lipid-laden foam cells.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗

PubMed2005

Exocytosis and endocytosis of small vesicles in PC12 cells studied with TEPIQ (two-photon extracellular polar-tracer imaging-based quantification) analysis.

We investigated exocytosis of PC12 cells using two-photon excitation imaging and extracellular polar tracers (TEP imaging) in the lateral membranes not facing the glass-cover slip. Upon photolysis of a caged Ca2+ compound, TEP imaging with FM1-43 (a polar membrane tracer) detected massive exocytosis of vesicles with a time constant of about 1 s. TEPIQ (two-photon extracellular polar-tracer imaging-based quantification) analysis revealed that the diameter of vesicles was small (55 nm). Extensive exocytosis of small vesicles (SVs) was shown to be mediated by the transient opening of a fusion pore with a diameter less than about 1.6 nm, and to be followed by direct ('kiss-and-run') endocytosis and translocation of the endocytic vesicles (EVs) deep into the cytoplasm. These processes were unaffected by GTP-gamma-S. In contrast, constitutive endocytic vesicles exhibited a diameter of 90 nm, took up molecules with a diameter of > 12 nm, and their formation was blocked by GTP-gamma-S. Electron-microscopic investigation with photoconversion of diaminobenzidine using FM1-43 confirmed an abundance of EVs with a diameter of 54 nm in stimulated cells. They rapidly translocated into the cytosol, and fused with endosomal organelles. The number of SV exocytosis events vastly exceeded the number of SVs morphologically docked at the plasma membrane. Simultaneous capacitance and FM1-43 measurements indicated that TEP imaging detected most SV exocytosis, and the fusion pore was closed within 2 s. Thus, we have, for the first time, directly visualized massive exocytosis of small vesicles in a non-synaptic preparation, and have revealed their fusion-pore mediated exocytosis and endocytosis.

Anatomy, Cross-Sectional↗

PubMed2003

Epstein-Barr virus latent membrane protein-1 (LMP-1) and lytic LMP-1 localization in plasma membrane-derived extracellular vesicles and intracellular virions.

Epstein-Barr virus (EBV) is a human herpesvirus associated with a number of malignancies. EBV establishes a latent infection in human B cells in vitro, and infected lymphoblastoid cells proliferate indefinitely as a result of virus activation of cellular signalling pathways. Latently infected cells express a viral oncoprotein called the latent membrane protein-1 (LMP-1). LMP-1 signals both proliferative and survival signals to the infected B cell. The switch from latency to lytic replication is associated with upregulation of an N-terminally truncated LMP-1, called lytic LMP-1 (lyLMP-1). To understand better the relationship between LMP-1 protein function and the virus life cycle, LMP-1 and lyLMP-1 were precisely localized in infected B cells. Immunoelectron microscopy of latently infected cells revealed LMP-1 localized in discrete patches in the plasma membrane. Unexpectedly, immunogold-labelled LMP-1 was found in vesicles budding from the plasma membrane into the extracellular space and in small membrane vesicles accumulating in conditioned medium from infected cells. LyLMP-1 immunolabelling was observed only in B95-8 cells harbouring detectable intracellular virus particles and was abundant in the nuclear membrane early, and in the plasma membrane late, following lytic cycle induction. LyLMP-1 immunoreactivity was also observed at sites of virus budding and associated with intracellular virions, suggesting that lyLMP-1 might be incorporated into cytoplasmic virions when budding through the nuclear membrane.

B-Lymphocytes↗

PubMed2003

Basic calcium phosphate crystals stimulate the endocytotic activity of cells--inhibition by anti-calcification agents.

Pathological calcifications are associated with many medical conditions including diabetes, breast cancer, and crystals-associated osteoarthritis. The deposition of calcium-containing crystals on cells induces detrimental cellular effects and speeds up the progression of associated diseases. We carried out the present study to test the hypotheses that calcium-containing crystals may stimulate the influx of other molecules existing in the extracellular fluid disturbing normal molecular signaling and that anti-calcification agent will inhibit such endocytotic process. We found that basic calcium phosphate (BCP) crystals greatly stimulated the endocytotic activity of cells by rendering the cells more permeable and that the anti-calcification agent phosphocitrate and several others inhibited the crystals-mediated endocytosis. This is the first study reporting that the endocytotic activity of cells is affected by BCP crystals and that such endocytotic activity can be inhibited by anti-calcification agents. Since calcium-containing crystals are associated with many human diseases and in many circumstances are associated with apoptotic bodies, extracellular and matrix vesicles where DNA fragments, small peptides, and minerals are released into extracellular space, the findings reported here are important for our understanding of the complex biological effects and the potential pathological role of calcium-containing crystals in crystals-associated diseases, and for the development of disease modifying agents as well.

Breast Neoplasms↗