BLTP2 bridges the ER and MVB for exosome biogenesis at SCAMP3-dependent ER contacts
Ontology highlight
ABSTRACT:
ORGANISM(S): Homo Sapiens Mus Musculus
SUBMITTER: 
Weike Ji
PROVIDER: PXD081583 | iProX | Thu Jul 23 00:00:00 GMT+01:00 2026
REPOSITORIES: iProX
Similar Datasets
Project description:Toll-like receptor 4 (TLR4), a pattern-recognition receptor located on the plasma membrane, senses extracellular danger signals to initiate inflammatory immune responses. It is initially synthesized in the endoplasmic reticulum (ER), undergoes N-linked glycosylation, and is subsequently transported to the Golgi before ultimately reaching the plasma membrane. However, the mechanisms underlying the processing and maturation of TLR4 in the ER remain elusive. Through whole genome-wide CRISPR screening, CCDC134 was identified as a critical and essential factor for TLR4-dependent inflammatory response. Localization of CCDC134 in the ER lumen rather than its exosome-mediated secretion is required for its role in TLR4 signaling. Loss of CCDC134 results in the retention of TLR4 in the ER for subsequent ER-associated degradation, and thus blockade of TLR4 maturation and plasma membrane trafficking. Defects in TLR4 processing and maturation in the ER in CCDC134-depleted cells are caused by aberrant hyperglycosylation and destabilization of glycoprotein 96 (gp96), a key chaperone of TLR4. These results suggest that CCDC134 controls gp96 glycosylation to facilitate TLR4 maturation in the ER.
2025-08-01 | GSE297380 | GEO
Project description:Exosomes, extracellular vesicles (EV) of endosomal origin, emerge as master regulators of cell-to-cell signaling in physiology and various systemic diseases. Exosomes are highly enriched in tetraspanins (TSPN) and syndecans (SDC), the latter occurring mainly in proteolytically-cleaved form, as membrane-spanning C-terminal fragments of the proteins. While both protein families are membrane scaffolds appreciated for their role in exosome formation, composition and activity, we currently ignore whether these work together to control exosome biology. Here we show that TSPN6, a poorly characterized tetraspanin, acts as a negative regulator of exosome release by supporting the lysosomal degradation of SDC4 and syntenin. In addition, we demonstrate that TSPN6 tightly associates with SDC4. Interestingly, TSPN6-dependent lysosomal degradation of syntenin strictly requires SDC4. TSPN6 also inhibits the shedding of the SDC4-ectodomain, mimicking the effects of matrix metalloproteinase inhibitors. Taken together our data identify TSPN6 as a regulator of the trafficking and processing of SDC4 and highlight an important physical and functional interconnection between these membrane scaffolds for the production of exosomes. These findings clarify our understanding of the molecular determinants governing EV formation and have potentially broad impact for EV-related biomedicine.
2020-02-12 | PXD014559 | Pride
Project description:Introduction:Repetitive RNA sequences like CAG repeats that trigger aberrant RNA-protein interactions cause several neurodegenerative diseases including Huntington's disease (HD). Importantly, these aberrant RNA-protein complexes also seed the formation of cytoplasmic liquid-like granules, such as the stress granules. Emerging evidence demonstrates that granules formed via liquid-liquid phase separation can mature into gel-like inclusions that persist within the cell and may act as precursor to aggregates that occur in patients’ tissue. Thus, deregulation of RNA granule biology is an important component of neurodegeneration. Interestingly, the formation of intracellular membrane-less organelles like stress granules increases along with the secretion of exosomes. Exosomes are small membrane-bound vesicles that are secreted generally by all cell types. They may participate in the spreading of misfolded proteins and aberrant RNA-protein complexes across the central nervous system in neurodegenerative diseases like HD. Moreover, due to their capability to cross the blood-brain barrier, exosomes hold great potential as sources of biomarkers available from the periphery, e.g., from blood. In this study, we performed a comparative transcriptomic analysis of exosomes and RNA granules in an HD model.Methods: Exosomes and RNA granules were isolated from an HD cell model, stably expressing HTT exon 1 with 83 CAG repeats under an inducible promoter. Both exosomes and RNA granules were isolated from induced (HD) and non-induced (control) cells and analysed by RNA sequencing.Results: Comparative analysis between the transcriptomics data of HD RNA granules and exosomes showed that: (I) intracellular RNA granules and extracellular RNA vesicles share content, (II) several non-coding RNAs translocate to RNA granules, (III) the composition of RNA granules and exosomes is affected by expression of mutant HTT.Discussion: Our data show that intracellular RNA granules and exosomes share content, suggesting that formation of RNA granules and exosome loading may be related. Moreover, our data suggest that both intracellular RNA granules and extracellular RNA vesicles may serve as a source for diagnostic strategies. For example, disease-specific RNA-signatures of exosomes can serve as biomarker of central nervous system diseases. However, the cell-type specific signature of EV-secreted RNAs may make it difficult to detect these biomarkers in blood.
2025-03-19 | GSE261143 | GEO
Project description:Background: Docosahexaenoic acid (DHA) is a natural compound with anticancer and anti-angiogenesis activity that is currently under investigation as both a preventative agent and an adjuvant to breast cancer therapy. However, the precise mechanisms of DHA’s anticancer activities are unclear. It is understood that the intercommunication between cancer cells and their microenvironment is essential to tumor angiogenesis. Exosomes are extracellular vesicles that are important mediators of intercellular communication and play a role in promoting angiogenesis. However, very little is known about the contribution of breast cancer exosomes to tumor angiogenesis or whether exosomes can mediate DHA’s anticancer action. Results: Exosomes were collected from MCF7 and MDA-MB-231 breast cancer cells after treatment with DHA. We observed an increase in exosome secretion and exosome microRNA contents from the DHA-treated cells. The expression of 83 microRNAs in the MCF7 exosomes was altered by DHA (>2-fold). The most abundant exosome microRNAs (let-7a, miR-23b, miR-27a/b, miR-21, let-7, and miR-320b) are known to have anti-cancer and/or anti-angiogenic activity. These microRNAs were also increased by DHA treatment in the exosomes from other breast cancer lines (MDA-MB-231, ZR751 and BT20), but not in exosomes from normal breast cells (MCF10A). When DHA-treated MCF7 cells were co-cultured with or their exosomes were directly applied to endothelial cell cultures, we observed an increase in the expression of these microRNAs in the endothelial cells. Furthermore, overexpression of miR-23b and miR-320b in endothelial cells decreased the expression of their pro-angiogenic target genes (PLAU, AMOTL1, NRP1 and ETS2) and significantly inhibited tube formation by endothelial cells, suggesting that the microRNAs transferred by exosomes mediate DHA’s anti-angiogenic action. These effects could be reversed by knockdown of the Rab GTPase, Rab27A, which controls exosome release. Conclusions: We conclude that DHA alters breast cancer exosome secretion and microRNA contents, which leads to the inhibition of angiogenesis. Our data demonstrate that breast cancer exosome signaling can be targeted to inhibit tumor angiogenesis and provide new insight into DHA’s anticancer action, further supporting its use in cancer therapy. Examination of small RNA populations in MCF7 cells and exosomes after DHA treatment.
2015-07-01 | E-GEOD-70432 | biostudies-arrayexpress
Project description:Stephen Paget first proposed, in 1889, that organ distribution of metastases is a non-random event, yet metastatic organotropism remains one of the greatest mysteries in cancer biology. Here, we demonstrate that exosomes released by lung-, liver- and brain-tropic tumor cells fuse preferentially with resident cells at their predicted destination, such as fibroblasts and epithelial cells in the lung, Kupffer cells in the liver, and endothelial cells in the brain. We found that exosome homing to organ-specific cell types prepares the pre-metastatic niche and that treatment with exosomes derived from lung tropic models can redirect metastasis to the lung. Proteomic profiling of exosomes revealed distinct integrin expression patterns associated with each organ-specific metastasis. Whereas exosomal integrins α6β4 and α6β1 were associated with lung metastasis, exosomal integrins αvβ5 and αvβ3 were linked with liver and brain metastases, respectively. Targeting α6β4 and αvβ5 integrins decreased exosome uptake and metastasis in the lung and liver, respectively. Importantly, we demonstrate that exosome uptake activates a cell-specific subset of S100 family genes, known to support cell migration and niche formation. Finally, our clinical data indicate that integrin-expression profiles in circulating plasma exosomes from cancer patients could be used to predict organ-specific metastasis. Education of human von Kupffer cells in vitro with human pancreatic cancer exosomes
2015-06-17 | E-GEOD-68919 | biostudies-arrayexpress
Project description:Cells release intraluminal vesicles (ILVs) in multivesicular bodies as exosomes to communicate with other cells. Although recent studies suggest an intimate link between exosome biogenesis and autophagy, the detailed mechanism is not fully understood. Here we employed comprehensive RNAi screening for autophagy-related factors and discovered that Rubicon, a negative regulator of autophagy, is essential for exosome release. Rubicon recruits WIPI2d to endosomes to promote exosome biogenesis. Interactome analysis of WIPI2d identified the ESCRT components that are required for ILV formation. Notably, we found that Rubicon is required for an age-dependent increase of exosome release in mice. In addition, small RNA sequencing of serum exosomes revealed that Rubicon determines the fate of exosomal microRNAs associated with aging and longevity pathways. Taken together, our current results suggest that the Rubicon-WIPI axis functions as a key regulator of exosome biogenesis and is responsible for the age-dependent changes in exosome quantity and quality.
2024-06-25 | GSE262794 | GEO
Project description:Recently, the existence of extracellular miRNAs enclosed in exosomes has raised the possibility that they play an important role in cell-cell communication. To gain more insight into cell-cell communication via exosomal miRNAs, we investigated whether or not tumor cells exposed to hypoxia secrete exosomes which may affect angiogeneic activity. We used RPMI8226 cells, as donor cells, and HUVECs as recipient cells. Exosomes derived from RPMI8226 cells cultured in normoxia (20%) or hypoxia (1%) for 24 h were used for validation of angiogeneic activity, such as tube formation assay. The exosome secreted from RPMI8226 cells in hypoxic condition significantly enhanced tube formation by HUVECs when compared with exosome obtained from RPMI8226 cell in normoxic condition. To identify cellular and exosomal miRNAs universally responding to hypoxic condition, we assess the expression profiles of intercellular and extracellular miRNAs in RPMI8226 cells cultured in normoxia (20%) or hypoxia (1%) for 24 h using Taqman MicroRNA Array v2.0 (Applied Biosystems, Bedford, MA). RPMI8226 cells were cultured for 24 hours under hypoxic conditions (1% O2) or normoxic conditions (20% O2). The exosome fraction was obtained from culture medium using Exoquick Exosome Precipitation Solution (System Biosciences, Mountain View, CA, USA). Isolation of cellular and exosomal miRNAs was performed using the miRNsasy kit (Qiagen). The expression profile of miRNAs was determined using the Human Taqman miRNA Arrays A (Applied Biosystems). RNU6B and a spike control (ath-miR159) were used as an invariant control for the cell and exosome, respectively. QRT-PCR was carried out on an Applied Biosystems 7900HT thermal cycler using the manufacturerM-bM-^@M-^Ys recommended program. Finally, all the raw data from each array was run on Data Assist Software ver.3.1 (Applied Biosystems).
2013-12-03 | E-GEOD-45388 | biostudies-arrayexpress
Project description:Recently, the existence of extracellular miRNAs enclosed in exosomes has raised the possibility that they play an important role in cell-cell communication. To gain more insight into cell-cell communication via exosomal miRNAs, we investigated whether or not tumor cells exposed to hypoxia secrete exosomes which may affect angiogeneic activity. We used SUDHL4 cells, as donor cells, and HUVECs as recipient cells. Exosomes derived from SUDHL4 cells cultured in normoxia (20%) or hypoxia (1%) for 24 h were used for validation of angiogeneic activity, such as tube formation assay. The exosome secreted from SUDHL4 cells in hypoxic condition significantly enhanced tube formation by HUVECs when compared with exosome obtained from SUDHL4 cell in normoxic condition. To identify cellular and exosomal miRNAs universally responding to hypoxic condition, we assess the expression profiles of intercellular and extracellular miRNAs in SUDHL4 cells cultured in normoxia (20%) or hypoxia (1%) for 24 h using Taqman MicroRNA Array v2.0 (Applied Biosystems, Bedford, MA). SUDHL4 cells were cultured for 24 hours under hypoxic conditions (1% O2) or normoxic conditions (20% O2). The exosome fraction was obtained from culture medium using Exoquick Exosome Precipitation Solution (System Biosciences, Mountain View, CA, USA). Isolation of cellular and exosomal miRNAs was performed using the miRNsasy kit (Qiagen). The expression profile of miRNAs was determined using the Human Taqman miRNA Arrays A (Applied Biosystems). RNU6B and a spike control (ath-miR159) were used as an invariant control for the cell and exosome, respectively. QRT-PCR was carried out on an Applied Biosystems 7900HT thermal cycler using the manufacturerM-bM-^@M-^Ys recommended program. Finally, all the raw data from each array was run on Data Assist Software ver.3.1 (Applied Biosystems).
2013-12-03 | E-GEOD-45387 | biostudies-arrayexpress
Project description:Recently, the existence of extracellular miRNAs enclosed in exosomes has raised the possibility that they play an important role in cell-cell communication. To gain more insight into cell-cell communication via exosomal miRNAs, we investigated whether or not tumor cells exposed to hypoxia secrete exosomes which may affect angiogeneic activity. We used K562 cells, as donor cells, and HUVECs as recipient cells. Exosomes derived from K562 cells cultured in normoxia (20%) or hypoxia (1%) for 24 h were used for validation of angiogeneic activity, such as tube formation assay. The exosome secreted from K562 cells in hypoxic condition significantly enhanced tube formation by HUVECs when compared with exosome obtained from K562 cell in normoxic condition. To identify cellular and exosomal miRNAs universally responding to hypoxic condition, we assess the expression profiles of intercellular and extracellular miRNAs in K562 cells cultured in normoxia (20%) or hypoxia (1%) for 24 h using Taqman MicroRNA Array v2.0 (Applied Biosystems, Bedford, MA). K562 cells were cultured for 24 hours under hypoxic conditions (1% O2) or normoxic conditions (20% O2). The exosome fraction was obtained from culture medium using Exoquick Exosome Precipitation Solution (System Biosciences, Mountain View, CA, USA). Isolation of cellular and exosomal miRNAs was performed using the miRNsasy kit (Qiagen). The expression profile of miRNAs was determined using the Human Taqman miRNA Arrays A (Applied Biosystems). RNU6B and a spike control (ath-miR159) were used as an invariant control for the cell and exosome, respectively. QRT-PCR was carried out on an Applied Biosystems 7900HT thermal cycler using the manufacturerM-bM-^@M-^Ys recommended program. Finally, all the raw data from each array was run on Data Assist Software ver.3.1 (Applied Biosystems).
2013-12-03 | E-GEOD-45289 | biostudies-arrayexpress
Project description:Signalling between endothelial cells, endothelial progenitor cells and stromal cells is crucial for the establishment and maintenance of vascular integrity and involves exosomes, among other signalling pathways. Exosomes are important mediators of intercellular communication in immune signalling, tumour survival, stress responses and angiogenesis. The ability of exosomes to incorporate and transfer mRNAs encoding for ‘acquired’ proteins or miRNAs repressing ‘resident’ mRNA translation suggests that they can influence the physiological behaviour of recipient cells. We here demonstrate that miR-214, a miRNA that controls endothelial cell function and angiogenesis, plays a dominant role in exosome-mediated signalling between endothelial cells. Endothelial cell-derived exosomes stimulated migration and angiogenesis in recipient cells, whereas exosomes from miR-214 depleted endothelial cells failed to stimulate these processes. Exosomes containing miR-214 repressed the expression of Ataxia Telangiectasia Mutated in recipient cells, thereby preventing senescence and allowing blood vessel formation. Concordantly, specific reduction of miR-214 content in exosome-producing endothelial cells abolishes the angiogenesis the angiogenesis stimulatory function of the resulting exosomes. Collectively our data indicate that endothelial cells release miR-214 containing exosomes to stimulate angiogenesis through silencing of Ataxia Telangiectasia Mutated in neighbouring target cells. Gene expression analysis of HMEC endothelial cells exposed to supernatant containing either HMEC derived exosomes (miR-214 high), HMEC derived exosomes depleted of miR-214 (miR-214 low) or containing no exosomes (no exosomes). Each sample was analysed in duplo.
2013-03-22 | E-GEOD-45375 | biostudies-arrayexpress