scholarly journals Role and mechanisms of exosomal miRNAs in IBD pathophysiology

2020 ◽  
Vol 319 (6) ◽  
pp. G646-G654
Author(s):  
Sameena Wani ◽  
Ivy Ka Man Law ◽  
Charalabos Pothoulakis
Keyword(s):  
Information Exchange ◽  
Mammalian Cells ◽  
Target Genes ◽  
Cell Function ◽  
Recipient Cell ◽  
Intestinal Flora ◽  
Cell Communication ◽  
Gut Health ◽  
Specific Loading ◽  
Exosomal Mirnas

Exosomes represent secretory membranous vesicles used for the information exchange between cells and organ-to-organ communication. Exosome crosstalk mechanisms are involved in the regulation of several inflammatory bowel disease (IBD)-associated pathophysiological intestinal processes such as barrier function, immune responses, and intestinal flora. Functional biomolecules, mainly noncoding RNAs (ncRNAs), are believed to be transmitted between the mammalian cells via exosomes that likely play important roles in cell-to-cell communication, both locally and systemically. MicroRNAs (miRNAs) encapsulated in exosomes have generated substantial interest because of their critical roles in multiple pathophysiological processes. In addition, exosomal miRNAs are implicated in the gut health. MiRNAs are selectively and actively loaded into the exosomes and then transferred to the target recipient cell where they manipulate cell function through posttranscriptional silencing of target genes. Intriguingly, miRNA profile of exosomes differs from their cellular counterparts suggesting an active sorting and packaging mechanism of exosomal miRNAs. Even more exciting is the involvement of posttranscriptional modifications in the specific loading of miRNAs into exosomes, but the underlying mechanisms of how these modifications direct ncRNA sorting have not been established. This review gives a brief overview of the status of exosomes and exosomal miRNAs in IBD and also discusses potential mechanisms of exosomal miRNA sorting and delivering.

scholarly journals The roles of exosomal miRNAs and lncRNAs in lung diseases

2019 ◽  
Vol 4 (1) ◽  
Author(s):  
Yang Li ◽  
Zhengrong Yin ◽  
Jinshuo Fan ◽  
Siyu Zhang ◽  
Weibing Yang
Keyword(s):  
Lung Cancer ◽  
Information Exchange ◽  
Lung Diseases ◽  
Cell Communication ◽  
Diagnostic Methods ◽  
Chronic Obstructive ◽  
Obstructive Pulmonary Disease ◽  
Diagnostic Biomarkers ◽  
Exosomal Mirnas ◽  
New Ideas

Abstract An increasing number of studies have reported that exosomes released from various cells can serve as mediators of information exchange between different cells. With further exploration of exosome content, a more accurate molecular mechanism involved in the process of cell-to-cell communication has been revealed; specifically, microRNAs (miRNAs) and long noncoding RNAs (lncRNAs) are shuttled by exosomes. In addition, exosomal miRNAs and lncRNAs may play vital roles in the pathogenesis of several respiratory diseases, such as chronic obstructive pulmonary disease (COPD), lung cancer, and asthma. Consequently, exosomal miRNAs and lncRNAs show promise as diagnostic biomarkers and therapeutic targets in several lung diseases. This review will summarize recent knowledge about the roles of exosomal miRNAs and lncRNAs in lung diseases, which has shed light on the discovery of novel diagnostic methods and treatments for these disorders. Because there is almost no published literature about exosomal lncRNAs in COPD, asthma, interstitial lung disease, or tuberculosis, we summarize the roles of exosomal lncRNAs only in lung cancer in the second section. This may inspire some new ideas for researchers who are interested in whether lncRNAs shuttled by exosomes may play roles in other lung diseases.

scholarly journals Extracellular Vesicles: A Novel Messenger of Unicellular Microalgae Communication?

2020 ◽  
Author(s):  
Liqing Zhao ◽  
Rongfang Zhu ◽  
Yerong Liu ◽  
Chenchen Liu ◽  
Panpan Jiang ◽  
...  
Keyword(s):  
Cell Growth ◽  
Extracellular Vesicles ◽  
Information Exchange ◽  
Mammalian Cells ◽  
Cell Communication ◽  
Aquatic Environments ◽  
Growth Stages ◽  
Message Delivery ◽  
Membrane Structures ◽  
Bg11 Medium

Abstract Background Extracellular vesicles (EVs) are nanoparticles with membrane structures secreted by cells that play a role in the transfer of proteins, lipids, small RNAs, lncRNAs and DNA. Thus, EVs mediate mammalian cell-to-cell communication and have potential applications in the diagnosis and treatment of diseases. However, these studies have been primarily focused on the microenvironmental fluids between mammalian cells. Microalgae are single-celled organisms living in natural and dynamic aquatic environments. Whether microalgae can secrete EVs and adapt to changing environments via EV-mediated communication between cells is still unclear. ResultsWe demonstrated that EVs are widely present in microalgae and have surprisingly rich contents of miRNAs and proteins. The differential expression of miRNAs and proteins was correlated with different cell growth stages and abiotic stressors. Our preliminary data suggested that Chlamydomonas EVs significantly affected the growth of the cyanobacterium Synechocystis in full BG11 medium. However, incubating EVs isolated from Chlamydomonas with Synechocystis cells showed that EVs themselves did not promote cell growth in nitrogen depleted BG11 medium. In this case, EVs appear to function primarily via information sensing and message delivery between cells under nutrient stress conditions. More detailed studies need to be conducted to revise our current perspective on the distribution of nutrients in aquatic environments and how EVs may affect microbial communications and interactions.Conculsions These findings suggest that EVs may play a critically important role in information exchange between microalgal cells and, in turn, adaptation to changing aquatic environments.

scholarly journals Blockage of Notch Signaling Inhibits the Migration and Proliferation of Retinal Pigment Epithelial Cells

2013 ◽  
Vol 2013 ◽  
pp. 1-6 ◽  
Author(s):  
Weiwei Liu ◽  
Guorong Jin ◽  
Chongde Long ◽  
Xin Zhou ◽  
Yan Tang ◽  
...  
Keyword(s):  
Notch Signaling ◽  
Mammalian Cells ◽  
Retinal Pigment Epithelial ◽  
Target Genes ◽  
Retinal Pigment ◽  
Critical Role ◽  
Cell Communication ◽  
Retinal Pigment Epithelial Cells ◽  
Rpe Cells ◽  
Pigment Epithelial

The Notch signaling is an evolutionarily conserved cell-cell communication pathway that plays critical roles in the proliferation, survival, apoptosis, and fate determination of mammalian cells. Retinal pigment epithelial (RPE) cells are responsible for supporting the function of the neural retina and maintaining vision. This study investigated the function of Notch signaling in RPE cells. We found that the members of the Notch signaling pathway components were differentially expressed in RPE cells. Furthermore, blockage of Notch signaling inhibited the migration and proliferation of RPE cells and reduced the expression levels of certain Notch signaling target genes, including HES1, MYC, HEY2, and SOX9. Our data reveal a critical role of Notch signaling in RPE cells, suggesting that targeting Notch signaling may provide a novel approach for the treatment of ophthalmic diseases related to RPE cells.

scholarly journals Glycosylation of Cancer Extracellular Vesicles: Capture Strategies, Functional Roles and Potential Clinical Applications

Cells ◽  
2021 ◽  
Vol 10 (1) ◽  
pp. 109
Author(s):  
Álvaro M. Martins ◽  
Cátia C. Ramos ◽  
Daniela Freitas ◽  
Celso A. Reis
Keyword(s):  
Extracellular Vesicles ◽  
Biomarker Discovery ◽  
De Novo ◽  
Recipient Cell ◽  
Cell Communication ◽  
Cancer Biomarkers ◽  
Functional Roles ◽  
Molecular Information ◽  
Glycosylation Pathway ◽  
Organ Tropism

Glycans are major constituents of extracellular vesicles (EVs). Alterations in the glycosylation pathway are a common feature of cancer cells, which gives rise to de novo or increased synthesis of particular glycans. Therefore, glycans and glycoproteins have been widely used in the clinic as both stratification and prognosis cancer biomarkers. Interestingly, several of the known tumor-associated glycans have already been identified in cancer EVs, highlighting EV glycosylation as a potential source of circulating cancer biomarkers. These particles are crucial vehicles of cell–cell communication, being able to transfer molecular information and to modulate the recipient cell behavior. The presence of particular glycoconjugates has been described to be important for EV protein sorting, uptake and organ-tropism. Furthermore, specific EV glycans or glycoproteins have been described to be able to distinguish tumor EVs from benign EVs. In this review, the application of EV glycosylation in the development of novel EV detection and capture methodologies is discussed. In addition, we highlight the potential of EV glycosylation in the clinical setting for both cancer biomarker discovery and EV therapeutic delivery strategies.

LOSS OF GLUTATHIONE PEROXIDASE 1 ATTENUATES COLITIS AND IS CRITICAL IN ACTIVATING EPITHELIAL REGENERATIVE RESPONSES

2021 ◽  
Vol 27 (Supplement_1) ◽  
pp. S27-S27
Author(s):  
Jared Hendren ◽  
Koral Kasnyik ◽  
Christopher Williams ◽  
Sarah Short
Keyword(s):  
Stem Cell ◽  
Glutathione Peroxidase ◽  
Target Genes ◽  
Cell Function ◽  
Intestinal Inflammation ◽  
Cellular Metabolism ◽  
Intestinal Injury ◽  
Gene Set Enrichment Analysis ◽  
Intestinal Cell ◽  
Glutathione Peroxidase 1

Abstract Many selenium-containing “selenoproteins” function as antioxidants, and work by our lab and others has demonstrated that selenoproteins often protect against intestinal inflammatory diseases, including colitis. Glutathione peroxidase 1 (GPx1) is a ubiquitous, mitochondrial and cytosolic selenoprotein which catalyzes the reduction of hydrogen peroxide by glutathione. Previously, we determined that despite its antioxidant role, loss of GPx1 greatly reduced disease severity in the dextran sodium sulfate (DSS) colitis model. Furthermore, GPx1 loss increased baseline intestinal cell proliferation, enhanced enteroid plating efficiency, and induced expression of stem cell-associated genes, such as Lgr5. Next, we aimed to determine the mechanism by which GPx1 modifies response to DSS. We observed that GPx1 is increased in colonic tissues from DSS-treated mice as compared to nontreated controls, suggesting that GPx1 may functionally contribute to intestinal injury responses. While GPx1 is expressed in both intestinal epithelial and immune cells, in situ hybridization to visualize Gpx1 identified epithelial cells as the most highly expressing cell type, with the greatest Gpx1 upregulation observed in wound-adjacent and regenerative crypts. Next, we investigated whether GPx1 loss affects stem cell function after injury. Here, we determined that both proliferation (p<0.01) and Lgr5 expression (p<0.05) were increased in the crypts of Gpx1-/- DSS-treated mice in comparison to WT controls. Similarly, organoids established from ulcerative colitis tissue displayed increased growth rates (p<0.01), expression of stem cell and Wnt target genes such as AXIN2 (p<0.0001) and LGR5 (p<0.01), and proliferation (p<0.05) following GPX1 knockdown. Together, these results indicate that GPx1 has an epithelial-cell autonomous role, and that its loss activates stem cell and proliferative responses which may both protect from intestinal injury and promote healing. Interestingly, recent research has highlighted the role of cellular metabolism in maintaining intestinal stem cell function, and GPx1 has previously been implicated in these processes. RNA-sequencing from DSS-treated mice and gene set enrichment analysis identified a positive association with oxidative phosphorylation-associated genes in Gpx1-/- mice (NES: 1.78; FDR q-val: 0.01), suggesting altered metabolism which may favor stem cell function. Further analysis of cellular metabolism using GPX1 knockdown colorectal cancer cells observed higher basal respiration (p<0.0001) and ATP generation (p<0.0001). Together, these results suggest that unlike other intestinal selenoproteins studied to date, loss of GPx1 augments stem cell injury responses to protect against intestinal inflammation, likely via augmenting epithelial regenerative responses.

scholarly journals Set1 Targets Genes with Essential Identity and Tumor-Suppressing Functions in Planarian Stem Cells

Genes ◽  
2021 ◽  
Vol 12 (8) ◽  
pp. 1182
Author(s):  
Prince Verma ◽  
Court K. M. Waterbury ◽  
Elizabeth M. Duncan
Keyword(s):  
Stem Cells ◽  
Stem Cell ◽  
Mammalian Cells ◽  
Cell Function ◽  
Genotoxic Stress ◽  
Specific Gene ◽  
Cell Identity ◽  
Chromatin Signature ◽  
Lysine Methyltransferase

Tumor suppressor genes (TSGs) are essential for normal cellular function in multicellular organisms, but many TSGs and tumor-suppressing mechanisms remain unknown. Planarian flatworms exhibit particularly robust tumor suppression, yet the specific mechanisms underlying this trait remain unclear. Here, we analyze histone H3 lysine 4 trimethylation (H3K4me3) signal across the planarian genome to determine if the broad H3K4me3 chromatin signature that marks essential cell identity genes and TSGs in mammalian cells is conserved in this valuable model of in vivo stem cell function. We find that this signature is indeed conserved on the planarian genome and that the lysine methyltransferase Set1 is largely responsible for creating it at both cell identity and putative TSG loci. In addition, we show that depletion of set1 in planarians induces stem cell phenotypes that suggest loss of TSG function, including hyperproliferation and an abnormal DNA damage response (DDR). Importantly, this work establishes that Set1 targets specific gene loci in planarian stem cells and marks them with a conserved chromatin signature. Moreover, our data strongly suggest that Set1 activity at these genes has important functional consequences both during normal homeostasis and in response to genotoxic stress.

scholarly journals Peripheral Circulating Exosomal miRNAs Potentially Contribute to the Regulation of Molecular Signaling Networks in Aging

2020 ◽  
Vol 21 (6) ◽  
pp. 1908 ◽  
Author(s):  
Hongxia Zhang ◽  
Kunlin Jin
Keyword(s):  
Target Genes ◽  
Differentially Expressed ◽  
Molecular Signaling ◽  
Slow Development ◽  
Exosomal Mirnas ◽  
Pathways Analysis ◽  
Old Rats ◽  
Underlying Mechanisms ◽  
Signaling Components ◽  
Serum Exosomes

People are living longer than ever. Consequently, they have a greater chance for developing a functional impairment or aging-related disease, such as a neurodegenerative disease, later in life. Thus, it is important to identify and understand mechanisms underlying aging as well as the potential for rejuvenation. Therefore, we used next-generation sequencing to identify differentially expressed microRNAs (miRNAs) in serum exosomes isolated from young (three-month-old) and old (22-month-old) rats and then used bioinformatics to explore candidate genes and aging-related pathways. We identified 2844 mRNAs and 68 miRNAs that were differentially expressed with age. TargetScan revealed that 19 of these miRNAs are predicated to target the 766 mRNAs. Pathways analysis revealed signaling components targeted by these miRNAs: mTOR, AMPK, eNOS, IGF, PTEN, p53, integrins, and growth hormone. In addition, the most frequently predicted target genes regulated by these miRNAs were EIF4EBP1, insulin receptor, PDK1, PTEN, paxillin, and IGF-1 receptor. These signaling pathways and target genes may play critical roles in regulating aging and lifespan, thereby validating our analysis. Understanding the causes of aging and the underlying mechanisms may lead to interventions that could reverse certain aging processes and slow development of aging-related diseases.

Probiotics and Prebiotics on Intestinal Flora and Gut Health

2020 ◽  
pp. 85-103
Author(s):  
Mengfei Peng ◽  
Nana Frekua Kennedy ◽  
Andy Truong ◽  
Blair Arriola ◽  
Ahlam Akmel
Keyword(s):  
Intestinal Flora ◽  
Gut Health

scholarly journals Hydrogen, Bicarbonate, and Their Associated Exchangers in Cell Volume Regulation

2021 ◽  
Vol 9 ◽  
Author(s):  
Yizeng Li ◽  
Xiaohan Zhou ◽  
Sean X. Sun
Keyword(s):  
Ion Channels ◽  
Cell Volume ◽  
Volume Regulation ◽  
Mammalian Cells ◽  
Molecular Mechanisms ◽  
Cell Function ◽  
Water Flux ◽  
Cell Volume Regulation ◽  
Sodium Potassium ◽  
Before And After

Cells lacking a stiff cell wall, e.g., mammalian cells, must actively regulate their volume to maintain proper cell function. On the time scale that protein production is negligible, water flow in and out of the cell determines the cell volume variation. Water flux follows hydraulic and osmotic gradients; the latter is generated by various ion channels, transporters, and pumps in the cell membrane. Compared to the widely studied roles of sodium, potassium, and chloride in cell volume regulation, the effects of proton and bicarbonate are less understood. In this work, we use mathematical models to analyze how proton and bicarbonate, combined with sodium, potassium, chloride, and buffer species, regulate cell volume upon inhibition of ion channels, transporters, and pumps. The model includes several common, widely expressed ion transporters and focuses on obtaining generic outcomes. Results show that the intracellular osmolarity remains almost constant before and after cell volume change. The steady-state cell volume does not depend on water permeability. In addition, to ensure the stability of cell volume and ion concentrations, cells need to develop redundant mechanisms to maintain homeostasis, i.e., multiple ion channels or transporters are involved in the flux of the same ion species. These results provide insights for molecular mechanisms of cell volume regulation with additional implications for water-driven cell migration.

scholarly journals Different endurance exercises modulate NK cell cytotoxic and inhibiting receptors

2021 ◽  
Author(s):  
A. Pal ◽  
J. Schneider ◽  
K. Schlüter ◽  
K. Steindorf ◽  
J. Wiskemann ◽  
...  
Keyword(s):  
Target Genes ◽  
Acute Exercise ◽  
Cell Function ◽  
Nk Cell ◽  
Analysis Of Covariance ◽  
Autologous Serum ◽  
Post Intervention ◽  
Significant Group ◽  
Significant Difference ◽  
Over Time

Abstract Purpose Induction of IDO depends on the activation of AhR forming the AhR/IDO axis. Activated AhR can transcribe various target genes including cytotoxic and inhibiting receptors of NK cells. We investigated whether AhR and IDO levels as well as activating (NKG2D) and inhibiting (KIR2DL1) NK cell receptors are influenced by acute exercise and different chronic endurance exercise programs. Methods 21 adult breast and prostate cancer patients of the TOP study (NCT02883699) were randomized to intervention programs of 12 weeks of (1) endurance standard training or (2) endurance polarized training after a cardiopulmonary exercise test (CPET). Serum was collected pre-CPET, immediately post-CPET, 1 h post-CPET and after 12 weeks post-intervention. Flow cytometry analysis was performed on autologous serum incubated NK-92 cells for: AhR, IDO, KIR2DL1 and NKG2D. Differences were investigated using analysis-of-variance for acute and analysis-of-covariance for chronic effects. Results Acute exercise: IDO levels changed over time with a significant increase from post-CPET to 1 h post-CPET (p = 0.03). KIR2DL1 levels significantly decreased over time (p < 0.01). NKG2D levels remained constant (p = 0.31). Chronic exercise: for both IDO and NKG2D a significant group × time interaction, a significant time effect and a significant difference after 12 weeks of intervention were observed (IDO: all p < 0.01, NKG2D: all p > 0.05). Conclusion Both acute and chronic endurance training may regulate NK cell function via the AhR/IDO axis. This is clinically relevant, as exercise emerges to be a key player in immune regulation.

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