590 research outputs found
A novel recombinant antibody specific to full-length stromal derived factor-1 for potential application in biomarker studies
Background:
Stromal derived factor-1α (SDF-1α/CXCL12) is a chemokine that is up-regulated in diseases
characterised by tissue hypoxia, including myocardial infarction, ischaemic cardiomyopathy
and remote ischaemic conditioning (RIC), a technique of cyclical, non-injurious
ischaemia applied remote from the heart that protects the heat from lethal ischaemia-reperfusion
injury. Accordingly, there is considerable interest in SDF-1α as a potential biomarker
of such conditions. However, SDF-1α is rapidly degraded and inactivated by dipeptidyl peptidase
4 and other peptidases, and the kinetics of intact SDF-1α remain unknown.
Methods & results:
To facilitate investigation of full-length SDF-1α we established an ELISA using a novel
recombinant human antibody we developed called HCI.SDF1. HCI.SDF1 is specific to the
N-terminal sequence of all isoforms of SDF-1 and has a comparable KD to commercially
available antibodies. Together with a detection antibody specific to the α-isoform, HCI.SDF1
was used to specifically quantify full-length SDF-1α in blood for the first time. Using RIC
applied to the hind limb of Sprague-Dawley rats or the arms of healthy human volunteers,
we demonstrate an increase in SDF-1α using a commercially available antibody, as previously
reported, but an unexpected decrease in full-length SDF-1α after RIC in both species.
Conclusions:
We report for the first time the development of a novel recombinant antibody specific to fulllength
SDF-1. Applied to RIC, we demonstrate a significant decrease in SDF-1α that is at
odds with the literature and suggests a need to investigate the kinetics of full-length SDF-1α
in conditions characterised by tissue hypoxia
Ischaemic injuries
Professor Derek Yellon and Dr Sean Davidson discuss their research on preventing injury to the heart from ischaemia-reperfusion and the potentially protective role of exosome
The Caspase 1 Inhibitor VX-765 Protects the Isolated Rat Heart via the RISK Pathway
PURPOSE: Protecting the heart from ischaemia-reperfusion (IR) injury is a major goal in patients presenting with an acute myocardial infarction. Pyroptosis is a novel form of cell death in which caspase 1 is activated and cleaves interleukin 1ÎČ. VX-785 is a highly selective, prodrug caspase 1 inhibitor that is also clinically available. It has been shown to be protective against acute IR in vivo rat model, and therefore might be a promising possibility for future cardioprotective therapy. However, it is not known whether protection by VX-765 involves the reperfusion injury salvage kinase (RISK) pathway. We therefore investigated whether VX-765 protects the isolated, perfused rat heart via the PI3K/Akt pathway and whether protection was additive with ischaemic preconditioning (IPC). METHODS: Langendorff-perfused rat hearts were subject to ischaemia and reperfusion injury in the presence of 30Â ÎŒM VX-765, with precedent IPC, or the combination of VX-765 and IPC. RESULTS: VX-765 reduced infarct size (28 vs 48% control; Pâ<â0.05) to a similar extent as IPC (30%; Pâ<â0.05). The PI3 kinase inhibitor, wortmannin, abolished the protective effect of VX-765. Importantly in the model used, we were unable to show additive protection with VX-765 + IPC. CONCLUSIONS: The caspase 1 inhibitor, VX-765, was able to reduce myocardial infarction in a model of IR injury. However, the addition of IPC did not demonstrate any further protection
Cardio-oncology Issues in Lymphoma Patients
Advances in Lymphoma management have resulted in significant improvements in patient outcomes over the last 50 years. Despite these developments, cardiotoxicity from lymphoma treatments remains an important cause of mortality and morbidity in this cohort of patients. We outlined the most common cardiotoxicities associated with lymphoma treatments and their respective investigation and management strategies, including the role of cardiac pre-assessment and late effects monitoring
Effects of macrophage depletion on characteristics of cervix remodeling and pregnancy in CD11b-dtr mice
Comparison of small extracellular vesicles isolated from plasma by ultracentrifugation or size-exclusion chromatography: yield, purity and functional potential
Interest in small extracellular vesicles (sEVs) as functional carriers of proteins and nucleic acids is growing continuously. There are large numbers of sEVs in the blood, but lack of standardised methods for sEV isolation greatly limits our ability to study them. In this report, we use rat plasma to systematically compare two commonly used techniques for isolation of sEVs: ultracentrifugation (UC-sEVs) and size-exclusion chromatography (SEC-sEVs). SEC-sEVs had higher particle number, protein content, particle/protein ratios and sEV marker signal than UC-sEVs. However, SEC-sEVs also contained greater amounts of APOB+ lipoproteins and large quantities of non-sEV protein. sEV marker signal correlated very well with both particle number and protein content in UC-sEVs but not in all of the SEC-sEV fractions. Functionally, both UC-sEVs and SEC-sEVs isolates contained a variety of proangiogenic factors (with endothelin-1 being the most abundant) and stimulated migration of endothelial cells. However, there was no evident correlation between the promigratory potential and the quantity of sEVs added, indicating that non-vesicular co-isolates may contribute to the promigratory effects. Overall, our findings suggest that UC provides plasma sEVs of lower yields, but markedly higher purity compared to SEC. Furthermore, we show that the functional activity of sEVs can depend on the isolation method used and does not solely reflect the sEV quantity. These findings are of importance when working with sEVs isolated from plasma- or serum-containing conditioned medium
Wake Up and Smell the Coffee: Yet Another No Go for Cardiac Patients?: Editorial to âCaffeinated Coffee Blunts the Myocardial Protective Effects of Statins Against Ischemiaâreperfusion Injury in the Ratâ by Ye et al.
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