64 results found
Chen S, Greasley SL, Ong ZY, et al., 2020, Biodegradable zinc-containing mesoporous silica nanoparticles for cancer therapy, Materials Today, Vol: 6, Pages: 1-11, ISSN: 1369-7021
Triple-negative breast cancers are extremely aggressive with limited treatment options because of the reduced response of the cancerous cells to hormonal therapy. Here, monodispersed zinc-containing mesoporous silica nanoparticles (MSNPs-Zn) were produced as a tuneable biodegradable platform for delivery of therapeutic zinc ions into cells. We demonstrate that the nanoparticles were internalized by cells, and a therapeutic dose window was identified in which the MSNPs-Zn were toxic to breast cancer cells but not to healthy epithelial (MCF-10a) cells or to murine macrophages. A significant reduction in the viability of triple negative MDA-MB-231 and MCF-7 (ER+) breast cancer cells was seen following 24 h exposure to MSNPs-Zn. The more aggressive MDA-MB-231 cells, with higher metastatic potential, were more sensitive to MSNPs-Zn than the MCF-7 cells. MSNPs-Zn underwent biodegradation inside the cells, becoming hollow structures, as imaged by high-resolution transmission electron microscopy. The mesoporous silica nanoparticles provide a biodegradable vehicle for therapeutic ion release inside cells.
Pillay J, Tregay N, Juzenaite G, et al., 2020, Effect of the CXCR4 antagonist plerixafor on endogenous neutrophil dynamics in the bone marrow, lung and spleen, Journal of Leukocyte Biology, Vol: 107, Pages: 1175-1185, ISSN: 0741-5400
Treatment with the CXCR4 antagonist, plerixafor (AMD3100), has been proposed for clinical use in patients with WHIM (warts, hypogammaglobulinemia, infections, and myelokathexis) syndrome and in pulmonary fibrosis. However, there is controversy with respect to the impact of plerixafor on neutrophil dynamics in the lung, which may affect its safety profile. In this study, we investigated the kinetics of endogenous neutrophils by direct imaging, using confocal intravital microscopy in mouse bone marrow, spleen, and lungs. Neutrophils are observed increasing their velocity and exiting the bone marrow following plerixafor administration, with a concomitant increase in neutrophil numbers in the blood and spleen, while the marginated pool of neutrophils in the lung microvasculature remained unchanged in terms of numbers and cell velocity. Use of autologous radiolabeled neutrophils and SPECT/CT imaging in healthy volunteers showed that plerixafor did not affect GM‐CSF‐primed neutrophil entrapment or release in the lungs. Taken together, these data suggest that plerixafor causes neutrophil mobilization from the bone marrow but does not impact on lung marginated neutrophil dynamics and thus is unlikely to compromise respiratory host defense both in humans and mice.
Sory DR, Amin HD, Chapman D, et al., 2020, Replicating landmine blast loading in cellular <i>in Vitro</i> models., Physical Biology, ISSN: 1478-3967
Trauma arising from landmines and improvised explosive devices promotes heterotopic ossification, the formation of extra-skeletal bone in non-osseous tissue. To date, experimental platforms that can replicate the loading parameter space relevant to improvised explosive device and landmine blast wave exposure have not been available to study the effects of such non-physiological mechanical loading on cells. Here, we present the design and calibration of three distinct in vitro experimental loading platforms that allow us to replicate the spectrum of loading conditions recorded in near-field blast wave exposure. We subjected cells in suspension or in a three-dimensional hydrogel to strain rates up to 6000 s-1and pressure levels up to 45 MPa. Our results highlight that cellular activation is regulated in a non-linear fashion - not by a single mechanical parameter, it is the combined action of the applied mechanical pressure, rate of loading and loading impulse, along with the extracellular environment used to convey the pressure waves. Finally, our research indicates that PO MSCs are finely tuned to respond to mechanical stimuli that fall within defined ranges of loading.
Fellous TG, Redpath AN, Fleischer MM, et al., 2020, Pharmacological tools to mobilise mesenchymal stromal cells into the blood promote bone formation after surgery, NPJ REGENERATIVE MEDICINE, Vol: 5
Clark J, Garbout A, Rodrigues Mendes Ferreira S, et al., 2020, Propagation phase-contrast micro-computed tomography allows laboratory-based three-dimensional imaging of articular cartilage down to the cellular level, Osteoarthritis and Cartilage, Vol: 28, Pages: 102-111, ISSN: 1063-4584
ObjectiveHigh-resolution non-invasive three-dimensional (3D) imaging of chondrocytes in articular cartilage remains elusive. The aim of this study was to explore whether laboratory micro-computed tomography (micro-CT) permits imaging cells within articular cartilage.DesignBovine osteochondral plugs were prepared four ways: in phosphate-buffered saline (PBS) or 70% ethanol (EtOH), both with or without phosphotungstic acid (PTA) staining. Specimens were imaged with micro-CT following two protocols: 1) absorption contrast (AC) imaging 2) propagation phase-contrast (PPC) imaging. All samples were scanned in liquid. The contrast to noise ratio (C/N) of cellular features quantified scan quality and were statistically analysed. Cellular features resolved by micro-CT were validated by standard histology.ResultsThe highest quality images were obtained using propagation phase-contrast imaging and PTA-staining in 70% EtOH. Cellular features were also visualised when stained in PBS and unstained in EtOH. Under all conditions PPC resulted in greater contrast than AC (p < 0.0001 to p = 0.038). Simultaneous imaging of cartilage and subchondral bone did not impede image quality. Corresponding features were located in both histology and micro-CT and followed the same distribution with similar density and roundness values.ConclusionsThree-dimensional visualisation and quantification of the chondrocyte population within articular cartilage can be achieved across a field of view of several millimetres using laboratory-based micro-CT. The ability to map chondrocytes in 3D opens possibilities for research in fields from skeletal development through to medical device design and treatment of cartilage degeneration.
De Filippo K, Rankin SM, 2018, CXCR4, the master regulator of neutrophil trafficking in homoeostasis and disease., European Journal of Clinical Investigation, Vol: 48, ISSN: 0014-2972
BACKGROUND: Chemokines play a critical role in orchestrating the distribution and trafficking of neutrophils in homoeostasis and disease. RESULTS: The CXCR4/CXCL12 chemokine axis has been identified as a central regulator of these processes. CONCLUSION: In this review, we focus on the role of CXCR4/CXCL12 chemokine axis in regulating neutrophil release from the bone marrow and the trafficking of senescent neutrophils back to the bone marrow for clearance under homoeostasis and disease. We also discuss the role of CXCR4 in fine-tuning neutrophil responses in the context of inflammation.
Sory DR, Amin HD, Rankin SM, et al., 2018, Osteogenic Differentiation of Periosteum-Derived Stromal Cells in Blast-Associated Traumatic Loading, 20th Biennial Conference of the Topical-Group of the American-Physical-Society (APS) on Shock Compression of Condensed Matter (SCCM), Publisher: AMER INST PHYSICS, ISSN: 0094-243X
Nguyen TN, Sory DR, Rankin SM, et al., 2018, Platform development for primary blast injury studies, Trauma (United Kingdom), ISSN: 1460-4086
© 2018, The Author(s) 2018. Explosion-related injuries are currently the most commonly occurring wounds in modern conflicts. They are observed in both military and civilian theatres, with complex injury pathophysiologies. Primary blast injuries are the most frequently encountered critical injuries experienced by victims close to the explosion. They are caused by large and rapid pressure changes of the blast waves which produce a wide range of loading patterns resulting in varied injuries. Well-characterised experimental loading devices which can reproduce the real mechanical characteristics of blast loadings on biological specimens in in vivo, ex vivo, and in vitro models are essential in determining the injury mechanisms. This paper discusses the performance and application of platforms, including shock tubes, mechanical testing machines, drop-weight rigs, and split-Hopkinson pressure bar, with regards to the replication of primary blast.
Iordachescu A, Amin HD, Rankin SM, et al., 2018, An In vitro model for the development of mature bone containing an osteocyte network, Advanced Biosystems, Vol: 2, ISSN: 2366-7478
Bone is a dynamic tissue that remodels continuously in response to local mechanical and chemical stimuli. This process can also result in maladaptive ectopic bone in response to injury, yet pathological differences at the molecular and structural levels are poorly understood. A number of in vivo models exist but can often be too complex to allow isolation of factors which may stimulate disease progression. A self‐structuring model of bone formation is presented using a fibrin gel cast between two calcium phosphate ceramic anchors. Femoral periosteal cells, seeded into these structures, deposit an ordered matrix that closely resembles mature bone in terms of chemistry (collagen:mineral ratio) and structure, which is adapted over a period of one year in culture. Raman spectroscopy and X‐ray diffraction confirm that the mineral is hydroxyapatite associated with collagen. Second‐harmonic imaging demonstrates that collagen is organized similarly to mature mouse femora. Remarkably, cells differentiated to the osteocyte phase are linked by canaliculi (as demonstrated with nano‐computed tomography) and remained viable over the full year of culture. It is demonstrated that novel drugs can prevent ossification in constructs. This model can be employed to study bone formation in an effort to encourage or prevent ossification in a range of pathologies.
Redpath AN, Francois M, Wong S-P, et al., 2017, Two distinct CXCR4 antagonists mobilize progenitor cells in mice by different mechanisms, BLOOD ADVANCES, Vol: 1, Pages: 1934-1943, ISSN: 2473-9529
Pharmacological mobilization of hematopoietic progenitor cells (HPCs) is used clinically to harvest HPCs for bone marrow transplants. It is now widely accepted that the CXCR4:CXCL12 chemokine axis plays a critical role in the retention of HPCs in the bone marrow, and CXCR4 antagonists have been developed for their mobilization. The first of this class of drugs to be US Food and Drug Administration-approved was the bicyclam AMD3100. In addition to mobilizing HPCs and leukocytes in naïve mice, AMD3100 has been shown to mobilize mesenchymal progenitor cells (MPCs) in vascular endothelial growth factor (VEGF-A) pretreated mice. AMD3100 binds to the transmembrane region of CXCR4 and is thought to mobilize HPCs by reversing the gradient of CXCL12 across the bone marrow endothelium. Consistent with this hypothesis, our data show that selective neutralization of CXCL12, with chalcone 4-phosphate (C4P), inhibited AMD3100-stimulated mobilization of HPCs and leukocytes in naïve mice and MPCs in VEGF-A pretreated mice. In contrast it is shown here that the CXCR4 antagonist KRH3955 that binds to the extracellular loop of CXCR4 does not reverse the CXCL12 chemokine gradient. However, this drug efficiently mobilizes HPCs, a response that is not inhibited by C4P. In contrast, KRH3955 does not mobilize MPCs in VEGF-A pretreated mice. These data suggest that CXCR4 antagonists that bind to distinct regions of the receptor mobilize progenitor cells by distinct molecular mechanisms.
Barnett-Vanes A, Sharrock A, Eftaxiopoulou T, et al., 2016, CD43Lo classical monocytes participate in the cellular immune response to isolated primary blast lung injury, Journal of Trauma and Acute Care Surgery, Vol: 81, Pages: 500-511, ISSN: 2163-0763
BACKGROUND: Understanding of the cellular immune response to primary blast lung injury (PBLI) is limited, with only the neutrophil response well documented. Moreover, its impact on the immune response in distal organs remains poorly understood. In this study, a rodent model of isolated primary blast injury was used to investigate the acute cellular immune response to isolated PBLI in the circulation and lung; including the monocyte response, and investigate distal sub-acute immune effects in the spleen and liver 6hr after injury. METHODS: Rats were subjected to a shock wave (~135kPa overpressure, 2ms duration) inducing PBLI or sham procedure. Rat physiology was monitored and at 1, 3 and 6 hr thereafter blood, lung, and Broncho-alveolar lavage fluid (BALF) were collected and analysed by flow cytometry (FCM), ELISA and Histology. In addition, at 6hr spleen and liver were collected and analysed by FCM. RESULTS: Lung histology confirmed pulmonary barotrauma and inflammation. This was associated with rises in CXCL-1, IL-6, TNF-α and albumin protein in the BALF. Significant acute increases in blood and lung neutrophils and CD43Lo/His48Hi (classical) monocytes/macrophages were detected. No significant changes were seen in blood or lung 'non-classical' monocyte, NK, B or T Cells. In the BALF, significant increases were seen in neutrophils, CD43Lo monocyte-macrophages and MCP-1. Significant increases in CD43Lo and Hi monocyte-macrophages were detected in the spleen at 6hr. CONCLUSIONS: This study reveals a robust and selective response of CD43Lo/His48Hi (classical) monocytes - in addition to neutrophils - in blood and lung tissue following PBLI. An increase in monocyte-macrophages was also observed in the spleen at 6hr. This profile of immune cells in the blood and BALF could present a new research tool for translational studies seeking to monitor, assess or attenuate the immune response in blast injured patients. EVIDENCE: Experimental laboratory study.WC- 300.
Eftaxiopoulou T, Barnett-Vanes A, Arora H, et al., 2016, Prolonged but not short duration blast waves elicit acute inflammation in a rodent model of primary blast limb trauma, Injury, Vol: 47, Pages: 625-632, ISSN: 0020-1383
BackgroundBlast injuries from conventional and improvised explosive devices account for 75% of injuries from current conflicts; of these over 70% involve the limbs. Variable duration and magnitude of blast wave loading occurs in real-life explosions and is hypothesised to cause different injuries. While a number of in-vivo models report the inflammatory response to blast injuries, the extent of this response has not been investigated with respect to the duration of the primary blast wave. The relevance is that explosions in open air are of short duration compared to those in confined spaces. MethodsHind limbs of adult Sprauge-Dawley rats were subjected to focal isolated primary blast waves of varying overpressure (1.8-3.65kPa) and duration (3.0-11.5ms), utilising a shock tube and purpose built experimental rig. Rats were monitored during and after blast. At 6 and 24hrs after exposure blood, lungs, liver and muscle tissue were collected and prepared for histology and flow cytometry.ResultsAt 6hrs increases in circulating neutrophils and CD43Lo/His48Hi monocytes were observed in rats subjected to longer duration blast waves. This was accompanied by increases in circulating pro-inflammatory chemo/cytokines KC and IL-6. No changes were observed with shorter duration blast waves irrespective of overpressure. In all cases, no histological damage was observed in muscle, lung or liver. By 24hrs post-blast all inflammatory parameters had normalised. ConclusionsWe report the development of a rodent model of primary blast limb trauma that is the first to highlight an important role played by blast wave duration and magnitude in initiating acute inflammatory response following limb injury in the absence of limb fracture or penetrating trauma. The combined biological and mechanical method developed can be used to further understand the complex effects of blast waves in a range of different tissues and organs in-vivo.
Barnett-Vanes A, Sharrock A, Birrell MA, et al., 2016, A single 9-colour flow cytometric method to characterise major leukocyte populations in the rat: validation in a model of LPS-induced pulmonary inflammation, PLOS One, Vol: 11, ISSN: 1932-6203
Chan JK, Glass GE, Ersek A, et al., 2015, Low-dose TNF augments fracture healing in normal and osteoporotic bone by up-regulating the innate immune response, EMBO MOLECULAR MEDICINE, Vol: 7, Pages: 547-561, ISSN: 1757-4676
Johnson JR, Folestad E, Rowley JE, et al., 2015, Pericytes contribute to airway remodeling in a mouse model of chronic allergic asthma, AMERICAN JOURNAL OF PHYSIOLOGY-LUNG CELLULAR AND MOLECULAR PHYSIOLOGY, Vol: 308, Pages: L658-L671, ISSN: 1040-0605
Singh RK, Furze RC, Birrell MA, et al., 2014, A role for Rab27 in neutrophil chemotaxis and lung recruitment, BMC CELL BIOLOGY, Vol: 15, ISSN: 1471-2121
Santo AIE, Chan JK, Glass GE, et al., 2014, Enhancement of fracture repair by upregulation of the innate immune response, EUROPEAN JOURNAL OF CLINICAL INVESTIGATION, Vol: 44, Pages: 30-31, ISSN: 0014-2972
Bo C, Williams A, Rankin S, et al., 2014, Integrated experimental platforms to study blast injuries: a bottom-up approach, 18th Joint Int Conf of the APS Topical-Grp on Shock Compress of Condensed Matter / 24th Int Conf of the Int-Assoc-for-the-Advancement-of-High-Pressure-Sci-and-Technol, Publisher: IOP PUBLISHING LTD, ISSN: 1742-6588
Byrne AJ, Jones CP, Gowers K, et al., 2013, Lung Macrophages Contribute to House Dust Mite Driven Airway Remodeling via HIF-1 alpha, PLOS ONE, Vol: 8, ISSN: 1932-6203
Strydom N, Lo Celso C, Rankin SM, 2013, Dynamic changes in neutrophil expression of chemokine receptors with aging and disease, EUROPEAN JOURNAL OF CLINICAL INVESTIGATION, Vol: 43, Pages: 13-14, ISSN: 0014-2972
Rankin SM, Martin C, Burdon PC, et al., 2013, Bone marrow - birth place and grave yard for neutrophils, EUROPEAN JOURNAL OF CLINICAL INVESTIGATION, Vol: 43, Pages: 12-12, ISSN: 0014-2972
Strydom N, Rankin SM, 2013, Regulation of Circulating Neutrophil Numbers under Homeostasis and in Disease, JOURNAL OF INNATE IMMUNITY, Vol: 5, Pages: 304-314, ISSN: 1662-811X
Pitchford SC, Lodie T, Rankin SM, 2012, VEGFR1 stimulates a CXCR4-dependent translocation of megakaryocytes to the vascular niche, enhancing platelet production in mice, BLOOD, Vol: 120, Pages: 2787-2795, ISSN: 0006-4971
Rankin SM, 2012, Chemokines and adult bone marrow stem cells, IMMUNOLOGY LETTERS, Vol: 145, Pages: 47-54, ISSN: 0165-2478
Rankin S, 2012, Mesenchymal stem cells, THORAX, Vol: 67, Pages: 565-566, ISSN: 0040-6376
Singh RK, Liao W, Tracey-White D, et al., 2012, Rab27a-mediated protease release regulates neutrophil recruitment by allowing uropod detachment, JOURNAL OF CELL SCIENCE, Vol: 125, Pages: 1652-1656, ISSN: 0021-9533
Dalli J, Jones CP, Cavalcanti DM, et al., 2012, Annexin A1 regulates neutrophil clearance by macrophages in the mouse bone marrow, FASEB JOURNAL, Vol: 26, Pages: 387-396, ISSN: 0892-6638
Bo C, Balzer J, Hahnel M, et al., 2012, CELLULAR CHARACTERIZATION OF COMPRESSION-INDUCEDDAMAGE IN LIVE BIOLOGICAL SAMPLES, 7th Biennial Conference of the American-Physical-Society-Topical-Group on Shock Compression of Condensed Matter, Publisher: AMER INST PHYSICS, ISSN: 0094-243X
Pitchford SC, Rankin SM, 2012, Combinatorial stem cell mobilization in animal models., Methods Mol Biol, Vol: 904, Pages: 139-154
It has long been recognized that single therapies, such as G-CSF, have a limited capacity to mobilize hematopoietic progenitor cells from the bone marrow. As a consequence in ∼20% of patients insufficient numbers of HPCs are mobilized to perform a bone marrow transplant. Recent studies have shown synergistic mobilization of HPCs when G-CSF pretreatment is combined with acute administration of a CXCR4 antagonist suggesting that combinatorial therapies may have therapeutic potential. In addition to HPCs, endothelial progenitor cells (EPCs) and mesenchymal stem cells (MSCs) reside in the bone marrow. These progenitor cells contribute to tissue regeneration and there is currently much interest in identifying the factors and mechanisms that regulate their mobilization. We describe a methodology for an in situ perfusion system of the mouse hind limb that permits direct quantification of stem and progenitor cell egress from the bone marrow. Progenitor cells are quantified by colony forming assays and immunohistochemistry. A strength of the methodology described is the ability to simultaneously quantify the mobilization of HPCs, EPCs and MSCs. Using this system we have shown that it is possible to achieve differential mobilization of these stem cell subsets using discrete combination therapies. Identification of such novel pharmacological regimens that stimulate the selective mobilization of EPCs and MSCs might be exploited in the future for tissue regeneration.
Jones CP, Rankin SM, 2011, Bone Marrow-Derived Stem Cells and Respiratory Disease, CHEST, Vol: 140, Pages: 205-211, ISSN: 0012-3692
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