Integrin Regulation in Immunological and Cancerous Cells and Exosomes

Integrins represent the biologically and medically significant family of cell adhesion molecules that govern a wide range of normal physiology. The activities of integrins in cells are dynamically controlled via activation-dependent conformational changes regulated by the balance of intracellular activators, such as talin and kindlin, and inactivators, such as Shank-associated RH domain interactor (SHARPIN) and integrin cytoplasmic domain-associated protein 1 (ICAP-1). The activities of integrins are alternatively controlled by homotypic lateral association with themselves to induce integrin clustering and/or by heterotypic lateral engagement with tetraspanin and syndecan in the same cells to modulate integrin adhesiveness. It has recently emerged that integrins are expressed not only in cells but also in exosomes, important entities of extracellular vesicles secreted from cells. Exosomal integrins have received considerable attention in recent years, and they are clearly involved in determining the tissue distribution of exosomes, forming premetastatic niches, supporting internalization of exosomes by target cells and mediating exosome-mediated transfer of the membrane proteins and associated kinases to target cells. A growing body of evidence shows that tumor and immune cell exosomes have the ability to alter endothelial characteristics (proliferation, migration) and gene expression, some of these effects being facilitated by vesicle-bound integrins. As endothelial metabolism is now thought to play a key role in tumor angiogenesis, we also discuss how tumor cells and their exosomes pleiotropically modulate endothelial functions in the tumor microenvironment.

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Elucidating the Innate Immunological Effects of Mild Magnetic Hyperthermia on U87 Human Glioblastoma Cells: An in vitro Study

10.20944/preprints202108.0494.v1 ◽

2021 ◽

Author(s):

Stefano Persano ◽

Francesco Vicini ◽

Alessandro Poggi ◽

Jordi Leonardo Castrillo Fernandez ◽

Giusy Maria Rita Rizzo ◽

...

Keyword(s):

Immune Cells ◽

Immune Cell ◽

Nk Cell ◽

Magnetic Hyperthermia ◽

Innate Immune ◽

Target Cells ◽

Innate Immune Cells ◽

Glioblastoma Cells ◽

Mild Hyperthermia ◽

Wide Range

Cancer immunotherapies are gaining a large popularity and many of them have been approved as standard second-line or in some cases even as first-line treatment for a wide range of cancers. However, immunotherapy has not shown a clinically relevant success in glioblastoma (GBM), principally due to the brain’s “immune-privileged” status and the peculiar tumor microenvironment (TME) of GBM featured by lack of presence of tumor-infiltrating lymphocytes and the establishment of immunosuppressive mechanisms. Emerging evidence has highlighted the key role played by innate immune cells in immunosurveillance and in initiating and driving immune responses against GBM. Immunogenic cell death (ICD) is a promising approach to elicit direct activation of the innate immune system by inducing in target cancer cells the expression of molecular signatures recognized through a repertoire of innate immune cell pattern recognition receptors (PRRs) by effector innate immune cells. Herein, we explored local mild thermal treatment, generated by using ultrasmall (size ~ 17 nm) cubic-shaped iron oxide nanoparticles exposed to an external alternating magnetic field (AMF), to induce ICD in U87 glioblastoma cells. In accordance with what has been previously observed with other types of tumors, we found that mild hyperthermia modulates the immunological profile of U87 glioblastoma cells by inducing stress-associated signals leading to enhanced phagocytosis and killing of U87 cells by macrophages. Finally, we demonstrated that mild magnetic hyperthermia has a modulatory effect on the expression of inhibitory and activating NK cell ligands on target cells. Interestingly, alteration in the expression of NK ligands, caused by mild hyperthermia treatment, in U87 glioblastoma cells, increased their susceptibility to NK cell killing and NK cell functionality. The overall findings demonstrate that mild magnetic hyperthermia stimulates ICD and sensitizes GBM cells to NK-mediated killing by inducing the upregulation of specific stress ligands, providing a novel immunotherapeutic approach for GBM treatment, with potential to synergize with existing NK cell-based therapies thus improving their therapeutic outcomes.

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MAP6-F Is a Temperature Sensor That Directly Binds to and Protects Microtubules from Cold-induced Depolymerization

Journal of Biological Chemistry ◽

10.1074/jbc.m112.398339 ◽

2012 ◽

Vol 287 (42) ◽

pp. 35127-35138 ◽

Cited By ~ 27

Author(s):

Christian Delphin ◽

Denis Bouvier ◽

Maxime Seggio ◽

Emilie Couriol ◽

Yasmina Saoudi ◽

...

Keyword(s):

Conformational Changes ◽

Temperature Sensor ◽

Cold Sensitivity ◽

Dependent Manner ◽

Temperature Dependent ◽

Microtubule Network ◽

Wide Range ◽

In Cells

Microtubules are dynamic structures that present the peculiar characteristic to be ice-cold labile in vitro. In vivo, microtubules are protected from ice-cold induced depolymerization by the widely expressed MAP6/STOP family of proteins. However, the mechanism by which MAP6 stabilizes microtubules at 4 °C has not been identified. Moreover, the microtubule cold sensitivity and therefore the needs for microtubule stabilization in the wide range of temperatures between 4 and 37 °C are unknown. This is of importance as body temperatures of animals can drop during hibernation or torpor covering a large range of temperatures. Here, we show that in the absence of MAP6, microtubules in cells below 20 °C rapidly depolymerize in a temperature-dependent manner whereas they are stabilized in the presence of MAP6. We further show that in cells, MAP6-F binding to and stabilization of microtubules is temperature- dependent and very dynamic, suggesting a direct effect of the temperature on the formation of microtubule/MAP6 complex. We also demonstrate using purified proteins that MAP6-F binds directly to microtubules through its Mc domain. This binding is temperature-dependent and coincides with progressive conformational changes of the Mc domain as revealed by circular dichroism. Thus, MAP6 might serve as a temperature sensor adapting its conformation according to the temperature to maintain the cellular microtubule network in organisms exposed to temperature decrease.

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Constant pH Molecular Dynamics Reveals How Proton Release Drives the Conformational Transition of a Transmembrane Efflux Pump

10.26434/chemrxiv.5496907 ◽

2017 ◽

Author(s):

Jana Shen ◽

Zhi Yue ◽

Helen Zgurskaya ◽

Wei Chen

Keyword(s):

Molecular Dynamics ◽

Conformational Changes ◽

Transmembrane Domain ◽

Conformational Transition ◽

Conformational Dynamics ◽

Proton Release ◽

Intrinsic Resistance ◽

Constant Ph ◽

Wide Range ◽

Constant Ph Molecular Dynamics

AcrB is the inner-membrane transporter of E. coli AcrAB-TolC tripartite efflux complex, which plays a major role in the intrinsic resistance to clinically important antibiotics. AcrB pumps a wide range of toxic substrates by utilizing the proton gradient between periplasm and cytoplasm. Crystal structures of AcrB revealed three distinct conformational states of the transport cycle, substrate access, binding and extrusion, or loose (L), tight (T) and open (O) states. However, the specific residue(s) responsible for proton binding/release and the mechanism of proton-coupled conformational cycling remain controversial. Here we use the newly developed membrane hybrid-solvent continuous constant pH molecular dynamics technique to explore the protonation states and conformational dynamics of the transmembrane domain of AcrB. Simulations show that both Asp407 and Asp408 are deprotonated in the L/T states, while only Asp408 is protonated in the O state. Remarkably, release of a proton from Asp408 in the O state results in large conformational changes, such as the lateral and vertical movement of transmembrane helices as well as the salt-bridge formation between Asp408 and Lys940 and other sidechain rearrangements among essential residues.Consistent with the crystallographic differences between the O and L protomers, simulations offer dynamic details of how proton release drives the O-to-L transition in AcrB and address the controversy regarding the proton/drug stoichiometry. This work offers a significant step towards characterizing the complete cycle of proton-coupled drug transport in AcrB and further validates the membrane hybrid-solvent CpHMD technique for studies of proton-coupled transmembrane proteins which are currently poorly understood. <p><br></p>

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pH-Dependent Thermal Stability of Vibrio cholerae L-asparaginase

Protein and Peptide Letters ◽

10.2174/0929866526666190617092944 ◽

2019 ◽

Vol 26 (10) ◽

pp. 743-750 ◽

Cited By ~ 1

Author(s):

Remya Radha ◽

Sathyanarayana N. Gummadi

Keyword(s):

Vibrio Cholerae ◽

Conformational Changes ◽

Kinetic Studies ◽

Structural Features ◽

Structure Stability ◽

Kcal Mole ◽

Scanning Calorimetry ◽

Wide Range ◽

Ph Dependent ◽

Ph Range

Background:pH is one of the decisive macromolecular properties of proteins that significantly affects enzyme structure, stability and reaction rate. Change in pH may protonate or deprotonate the side group of aminoacid residues in the protein, thereby resulting in changes in chemical and structural features. Hence studies on the kinetics of enzyme deactivation by pH are important for assessing the bio-functionality of industrial enzymes. L-asparaginase is one such important enzyme that has potent applications in cancer therapy and food industry.Objective:The objective of the study is to understand and analyze the influence of pH on deactivation and stability of Vibrio cholerae L-asparaginase.Methods:Kinetic studies were conducted to analyze the effect of pH on stability and deactivation of Vibrio cholerae L-asparaginase. Circular Dichroism (CD) and Differential Scanning Calorimetry (DSC) studies have been carried out to understand the pH-dependent conformational changes in the secondary structure of V. cholerae L-asparaginase.Results:The enzyme was found to be least stable at extreme acidic conditions (pH< 4.5) and exhibited a gradual increase in melting temperature from 40 to 81 °C within pH range of 4.0 to 7.0. Thermodynamic properties of protein were estimated and at pH 7.0 the protein exhibited ΔG37of 26.31 kcal mole-1, ΔH of 204.27 kcal mole-1 and ΔS of 574.06 cal mole-1 K-1.Conclusion:The stability and thermodynamic analysis revealed that V. cholerae L-asparaginase was highly stable over a wide range of pH, with the highest stability in the pH range of 5.0–7.0.

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Kaempferol Improves TRAIL-Mediated Apoptosis in Leukemia MOLT-4 Cells by the Inhibition of Anti-apoptotic Proteins and Promotion of Death Receptors Expression

Anti-Cancer Agents in Medicinal Chemistry ◽

10.2174/1871520619666190731155859 ◽

2019 ◽

Vol 19 (15) ◽

pp. 1835-1845

Author(s):

Ali Hassanzadeh ◽

Adel Naimi ◽

Majid F. Hagh ◽

Raedeh Saraei ◽

Faroogh Marofi ◽

...

Keyword(s):

Tumor Necrosis Factor ◽

Cancer Cells ◽

Tumor Necrosis ◽

Lymphoblastic Leukemia ◽

Annexin V ◽

Death Receptors ◽

Target Cells ◽

Wide Range ◽

Apoptotic Proteins ◽

Necrosis Factor

Introduction: Tumor necrosis factor-related apoptosis-inducing ligand (TRAIL or Apo2L) is a member of the tumor necrosis factor (TNF) superfamily, which stimulates apoptosis in a wide range of cancer cells via binding to death receptors 4 and 5 (DR4/5). Nevertheless, TRAIL has noticeable anti-cancer abilities; some cancer cells acquire resistance to TRAIL, and consequently its potential for inducing apoptosis in target cells is strongly diminished. Acute lymphoblastic leukemia MOLT-4 cell line is one of the most resistant cells to TRAIL that developed resistance to TRAIL via different pathways. We used TRAIL plus kaempferol to eliminate resistance of the MOLT-4 cells to TRAIL. Material and Methods: First, IC50 for kaempferol (95 µM) was determined by using the MTT assay. Second, the viability of the MOLT-4 cells was assayed by FACS after Annexin V/PI staining, following treatment with TRAIL (50 and 100 nM) and kaempferol (95 µM) alone and together. Finally, the expression levels of the candidate genes involved in resistance to TRAIL were assayed by real-time PCR technique. Results: Kaempferol plus TRAIL induced apoptosis robustly in MOLT-4 cells at 12, 24 and 48 hours after treatment. Additionally, we found that kaempferol could inhibit expression of the c-FLIP, X-IAP, cIAP1/2, FGF-8 and VEGF-beta, and conversely augment expression of the DR4/5 in MOLT-4 cells. Conclusion: We suggest that co-treatment of MOLT-4 cells with TRAIL plus kaempferol is a practical and attractive approach to eliminate cancers’ resistance to TRAIL via inhibition of the intracellular anti-apoptotic proteins, upregulation of DR4/5 and also by suppression of the VEGF-beta (VEGFB) and FGF-8 expressions.

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Hybrid Nanoassemblies from Viruses and DNA Nanostructures

Nanomaterials ◽

10.3390/nano11061413 ◽

2021 ◽

Vol 11 (6) ◽

pp. 1413

Author(s):

Sofia Ojasalo ◽

Petteri Piskunen ◽

Boxuan Shen ◽

Mauri A. Kostiainen ◽

Veikko Linko

Keyword(s):

Cell Activation ◽

Immune Cell ◽

Dna Nanotechnology ◽

Biological Properties ◽

Dna Nanostructures ◽

Dna Structures ◽

Nanoscale Structures ◽

Immune Cell Activation ◽

Wide Range ◽

Structural Dna Nanotechnology

Viruses are among the most intriguing nanostructures found in nature. Their atomically precise shapes and unique biological properties, especially in protecting and transferring genetic information, have enabled a plethora of biomedical applications. On the other hand, structural DNA nanotechnology has recently emerged as a highly useful tool to create programmable nanoscale structures. They can be extended to user defined devices to exhibit a wide range of static, as well as dynamic functions. In this review, we feature the recent development of virus-DNA hybrid materials. Such structures exhibit the best features of both worlds by combining the biological properties of viruses with the highly controlled assembly properties of DNA. We present how the DNA shapes can act as “structured” genomic material and direct the formation of virus capsid proteins or be encapsulated inside symmetrical capsids. Tobacco mosaic virus-DNA hybrids are discussed as the examples of dynamic systems and directed formation of conjugates. Finally, we highlight virus-mimicking approaches based on lipid- and protein-coated DNA structures that may elicit enhanced stability, immunocompatibility and delivery properties. This development also paves the way for DNA-based vaccines as the programmable nano-objects can be used for controlling immune cell activation.

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Tert-butylhydroquinone attenuates doxorubicin-induced dysregulation of testicular cytoprotective and steroidogenic genes, and improves spermatogenesis in rats

Scientific Reports ◽

10.1038/s41598-021-85026-7 ◽

2021 ◽

Vol 11 (1) ◽

Author(s):

Godwin Adakole Ujah ◽

Victor Udo Nna ◽

Joseph Bagi Suleiman ◽

Chinedum Eleazu ◽

Chukwuemeka Nwokocha ◽

...

Keyword(s):

Body Weight ◽

Sperm Count ◽

Reproductive Hormones ◽

Nuclear Antigen ◽

Albino Rats ◽

Target Cells ◽

Negative Effects ◽

Related Proteins ◽

Proliferating Cell ◽

Cancerous Cells

AbstractDoxorubicin (DOX) is a broad-spectrum chemotherapeutic drug used in the treatment of cancers. It acts by generating reactive oxygen species in target cells. The actions are, however, not limited to cancerous cells as it attacks healthy cells, killing them. This study investigated the benefits of the antioxidant, tert-butylhydroquinone (tBHQ), on testicular toxicity following DOX therapy. Twenty-four adult male albino rats were assigned randomly into four groups (n = 6), namely: normal control (NC), tBHQ, DOX and tBHQ + DOX groups. tBHQ (50 mg/kg body weight in 1% DMSO) was administered orally for 14 consecutive days, while a single DOX dose (7 mg/kg body weight) was administered intraperitoneally on Day 8. DOX decreased sperm count, motility and viability, and decreased the levels of steroidogenesis-related proteins, and reproductive hormones. Furthermore, DOX decreased the expression of antioxidant cytoprotective genes, and decreased the protein level of proliferating cell nuclear antigen in the testis. Conversely, DOX increased the expression of pro-inflammatory and pro-apoptotic genes in the testis. These negative effects were ameliorated following the intervention with tBHQ. Our results suggest that tBHQ protects the testis and preserves both steroidogenesis and spermatogenesis in DOX-treated rats through the suppression of oxidative stress, inflammation and apoptosis.

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Two-Color Probe to Monitor a Wide Range of pH Values in Cells

Angewandte Chemie International Edition ◽

10.1002/anie.201301894 ◽

2013 ◽

Vol 52 (24) ◽

pp. 6206-6209 ◽

Cited By ~ 174

Author(s):

Min Hee Lee ◽

Ji Hye Han ◽

Jae Hong Lee ◽

Nayoung Park ◽

Rajesh Kumar ◽

...

Keyword(s):

Ph Values ◽

Wide Range ◽

In Cells

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A novel electrochemical conducting polymer sensor for the rapid, selective and sensitive detection of biothiols

Polymer Chemistry ◽

10.1039/d1py01394g ◽

2021 ◽

Author(s):

Bicheng Zhu ◽

Devon Bryant ◽

Alireza Akbarinejad ◽

Jadranka Travas-Sejdic ◽

Lisa I Pilkington

Keyword(s):

Conducting Polymer ◽

Sensitive Detection ◽

Bodily Fluids ◽

Wide Range ◽

In Cells

Biological thiols (biothiols) in cells and bodily fluids are intrinsically linked to the functioning of important enzymes, deficiency in which can lead to a wide range of physiological and pathological...

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MicroRNA-Regulated Rickettsial Invasion into Host Endothelium via Fibroblast Growth Factor 2 and Its Receptor FGFR1

Cells ◽

10.3390/cells7120240 ◽

2018 ◽

Vol 7 (12) ◽

pp. 240 ◽

Cited By ~ 5

Author(s):

Abha Sahni ◽

Hema Narra ◽

Jignesh Patel ◽

Sanjeev Sahni

Keyword(s):

Gene Expression ◽

Endothelial Cells ◽

Growth Factor ◽

Fibroblast Growth Factor ◽

Host Cells ◽

Microvascular Endothelial Cells ◽

Target Cells ◽

Fibroblast Growth ◽

Wide Range ◽

Microvascular Endothelial

Microvascular endothelial cells (ECs) represent the primary target cells during human rickettsioses and respond to infection via the activation of immediate–early signaling cascades and the resultant induction of gene expression. As small noncoding RNAs dispersed throughout the genome, microRNAs (miRNAs) regulate gene expression post-transcriptionally to govern a wide range of biological processes. Based on our recent findings demonstrating the involvement of fibroblast growth factor receptor 1 (FGFR1) in facilitating rickettsial invasion into host cells and published reports suggesting miR-424 and miR-503 as regulators of FGF2/FGFR1, we measured the expression of miR-424 and miR-503 during R. conorii infection of human dermal microvascular endothelial cells (HMECs). Our results revealed a significant decrease in miR-424 and miR-503 expression in apparent correlation with increased expression of FGF2 and FGFR1. Considering the established phenomenon of endothelial heterogeneity and pulmonary and cerebral edema as the prominent pathogenic features of rickettsial infections, and significant pathogen burden in the lungs and brain in established mouse models of disease, we next quantified miR-424 and miR-503 expression in pulmonary and cerebral microvascular ECs. Again, R. conorii infection dramatically downregulated both miRNAs in these tissue-specific ECs as early as 30 min post-infection in correlation with higher FGF2/FGFR1 expression. Changes in the expression of both miRNAs and FGF2/FGFR1 were next confirmed in a mouse model of R. conorii infection. Furthermore, miR-424 overexpression via transfection of a mimic into host ECs reduced the expression of FGF2/FGFR1 and gave a corresponding decrease in R. conorii invasion, while an inhibitor of miR-424 had the expected opposite effect. Together, these findings implicate the rickettsial manipulation of host gene expression via regulatory miRNAs to ensure efficient cellular entry as the critical requirement to establish intracellular infection.

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