scholarly journals Negative Impact of Hypoxia on Tryptophan 2,3-Dioxygenase Function

2016 ◽  
Vol 2016 ◽  
pp. 1-11 ◽  
Author(s):  
Frank Elbers ◽  
Claudia Woite ◽  
Valentina Antoni ◽  
Sara Stein ◽  
Hiroshi Funakoshi ◽  
...  
Keyword(s):  
Essential Amino Acid ◽  
Negative Impact ◽  
Ex Vivo ◽  
T Cell Proliferation ◽  
Effector Functions ◽  
Protein Levels ◽  
Hypoxic Conditions ◽  
Oxygen Conditions

Tryptophan is an essential amino acid for hosts and pathogens. The liver enzyme tryptophan 2,3-dioxygenase (TDO) provokes, by its ability to degrade tryptophan to N-formylkynurenine, the precursor of the immune-relevant kynurenines, direct and indirect antimicrobial and immunoregulatory states. Up to now these TDO-mediated broad-spectrum effector functions have never been observed under hypoxiain vitro, although physiologic oxygen concentrations in liver tissue are low, especially in case of infection. Here we analysed recombinant expressed human TDO andex vivomurine TDO functions under different oxygen conditions and show that TDO-induced restrictions of clinically relevant pathogens (bacteria, parasites) and of T cell proliferation are abrogated under hypoxic conditions. We pinpointed the loss of TDO efficiency to the reduction of TDO activity, since cell survival and TDO protein levels were unaffected. In conclusion, the potent antimicrobial as well as immunoregulatory effects of TDO were substantially impaired under hypoxic conditions that pathophysiologically occurin vivo. This might be detrimental for the appropriate host immune response towards relevant pathogens.

The Impact of NFAT Inhibition on Neutrophil Effector Functions in Patients after Allogeneic Hematopoietic Stem Cell Transplantation and on Neutrophil Antifungal Defense and Myelopoiesis in Cyclosporin Α Treated and NFATc1LysM Mice

Blood ◽  
2016 ◽  
Vol 128 (22) ◽  
pp. 3679-3679
Author(s):  
Daniel Teschner ◽  
Katharina Plein ◽  
Christian Michel ◽  
Steve Pruefer ◽  
Matthias Bros ◽  
...  
Keyword(s):  
Progenitor Cells ◽  
Ex Vivo ◽  
Pulmonary Inflammation ◽  
Blood Samples ◽  
Effector Functions ◽  
Myeloid Progenitor ◽  
Healthy Donors ◽  
Myeloid Progenitor Cells

Abstract Background and Aims: Immunosuppressive medication e.g. by calcineurin inhibitors substantially contributes to the risk for opportunistic fungal infections in patients after allogeneic transplantation (HSCT). It is well known that the nuclear factor of activated T cells (NFAT) is an important transcription factor downstream of calcineurin especially in T cells. Additionally, recent data in rodent models indicate that NFAT also seems to play a relevant role in innate antifungal immune responses by polymorphonuclear neutrophils (PMN), as well as in regulation of myelopoiesis and myeloid differentiation. Methods: Firstly, isolated PMN from healthy donors were analyzed in vitro in absence or presence of CsA regarding their effector functions and activation-induced release of inflammatory mediators. Consecutively, blood samples of CsA-treated patients after allogeneic HSCT (n=17) and healthy donors (n=8) were analyzed ex vivo at two different time points as described above. Secondly, we used a murine IPA model (C57BL/6) and treated mice with CsA (18 mg/kg/d) or vehicle and challenged them with Aspergillus fumigatus (A. f.) conidia intratracheally. PMN recruitment to the lungs and pulmonary fungal clearance were examined by analyzing bronchoalveolar lavages (BAL) and peripheral blood (PB) using flow cytometry and cytometric bead array and murine lungs by fungal culture assays and histopathologic examination. Furthermore, survival was studied with neutropenic animals serving as positive controls. Moreover, LysM-specific NFATc1 knockout (NFATc1LysM) mice were bred lacking NFATc1 expression solely in myelomonocytic cells. These animals were also infected with A. f. and analyzed as further mentioned. In addition, we investigated myelopoiesis and myeloid differentiation by quantifying bone marrow derived myeloid progenitor cells from CsA treated or NFATc1LysMmice using flow cytometry and simultaneously counting PMN in PB under steady state conditions. Results: CsA enhanced phagocytosis of PMN in vitro and ex vivo in patients' blood samples (54.2 % +/- 4.1 (patients) vs. 43.8 +/- 1.5, LPS, p=0.006). Moreover, PMNs migratory capabilities were reduced in vitro, whereas other effector functions or release of IL-8 were rather unaffected. PMNs of CsA-treated patients showed increased activation, degranulation and production of inflammatory mediators, but production of ROS was slightly decreased. In our in vivo model, IPA was lethal in neutropenic mice whereas solely CsA or vehicle treated mice survived the infection. CsA treatment resulted in enhanced PMN recruitment in BAL by trend, while pulmonary inflammation and PMN counts in PB remained stable. Indeed, fungal clearance was clearly constrained in CsA　treated animals (2.1 x 105 CFU/lung +/- 0.5 (CsA) vs. 1.7 x 105 +/- 0.2, p<0.005). In our murine knockout model, NFATc1LysM mice infected with A. f. showed unimpaired survival without displaying detectable differences in PMN recruitment or fungal clearance. However, pulmonary inflammation and PMN counts in PB seemed to be more pronounced in knockout mice. Interestingly, BALs of CsA treated mice showed increased levels of IL-6 by trend (4634 pg/mL +/- 1073 (CsA) vs. 3108 +/- 729, p=0.48) but decreased levels of MCP-1 and TNF-α. In contrast, MCP-1, RANTES and TNF-α were enhanced by trend in BALs of NFATc1LysM mice, while IL-6 was reduced compared to wild type controls (3762 pg/mL +/- 729 vs. 4770 +/- 1613, p=0.81). PMN counts in PB were unaffected in NFATc1LysM mice but distribution of bone marrow derived murine myeloid progenitor cells was clearly impaired especially in megakaryocyte-erythroid progenitor cells (1.2 x 105 cells +/- 0.2 (NFATc1LysM) vs. 2.7 +/- 0.6, p=0.015), whereas solely CsA treatment had no influence. Conclusion: Results from our in vitro and ex vivo studies on patients' blood samples as well as from our murine in vivo IPA model indicate that NFAT regulates not only myelopoiesis, but also PMN functionalities in mice and humans. Nevertheless, these interactions are obviously multidimensional and potentially derive from involvement of different pathways. The underlying molecular mechanisms and clinical relevance of our findings in HSCT remain to be determined. Disclosures No relevant conflicts of interest to declare.

scholarly journals Experimental Strategies of Mesenchymal Stem Cell Propagation: Adverse Events and Potential Risk of Functional Changes

2019 ◽  
Vol 2019 ◽  
pp. 1-10 ◽  
Author(s):  
Katarzyna Drela ◽  
Luiza Stanaszek ◽  
Adam Nowakowski ◽  
Zuzanna Kuczynska ◽  
Barbara Lukomska
Keyword(s):  
Stem Cell ◽  
Negative Impact ◽  
Ex Vivo ◽  
Biological Properties ◽  
Therapeutic Effects ◽  
Functional Changes ◽  
Cell Propagation ◽  
Ex Vivo Culture

Mesenchymal stem cells (MSCs) are attractive candidates for cell-based tissue repair approaches. Hundreds of clinical trials using MSCs have been completed and many others are still being investigated. For most therapeutic applications, MSC propagation in vitro is often required. However, ex vivo culture condition is not fully physiological and may affect biological properties of MSCs including their regenerative potential. Moreover, both cell cryopreservation and labelling procedure prior to infusion may have the negative impact on their expected effect in vivo. The incidence of MSC transformation during in vitro culture should be also taken into consideration before using cells in stem cell therapy. In our review, we focused on different aspects of MSC propagation that might influence their regenerative properties of MSC. We also discussed the influence of different factors that might abolish MSC proliferation and differentiation as well as potential impact of stem cell senescence and aging. Despite of many positive therapeutic effects of MSC therapy, one has to be conscious about potential cell changes that could appear during manufacturing of MSCs.

PS02.174: THE ACTION OF A NOVEL RADIOSENSITISER WITHIN THE OESOPHAGEAL ADENOCARCINOMA TUMOUR MICROENVIROMENT

2018 ◽  
Vol 31 (Supplement_1) ◽  
pp. 171-171
Author(s):  
Amy Buckley ◽  
Niamh Lynam-Lennon ◽  
Susan Kennedy ◽  
Aoife Cannon ◽  
Dermott O’Toole ◽  
...  
Keyword(s):  
Conflicts Of Interest ◽  
Ex Vivo ◽  
Survival Rates ◽  
Oesophageal Adenocarcinoma ◽  
Naive Patient ◽  
Human Patient ◽  
Hypoxic Conditions ◽  
Treatment Naïve

Abstract Background Oesophageal Cancer (OAC) is an aggressive disease with survival rates of ∼15-20%. Current therapeutic regimes focus on neo-adjuvant therapy (chemo-radiation) prior to surgery. Unfortunately, only 20–30% of patients show a beneficial response, with 70–80% of patients as non-responders. This major clinical challenge of treatment resistance reinforces the need for the identification of novel treatments which can act as radio-sensitisers in the neo-adjuvant setting. Methods Through a drug screening approach in-vivo, we have identified a novel anti-angiogenic and anti-metabolic compound, 11B_CC8 with radiosensitising activity. The ability of 11B_CC8 to act as an anti-metabolic agent under hypoxia was evaluated using the XFe24 Seahorse analyser and the Don Whitley i2 workstation. The ability of 11B_CC8 to radiosensitise our isogenic OAC cells under hypoxic conditions was assessed by clonogenic assay. The effect of 11B_CC8 on inflammatory, metabolic and angiogenic protein secretions from OAC treatment naïve tumour conditioned media (TCM) was evaluated by multiplex ELISA. Fresh treatment naïve patient biopsies were screened for their metabolic activity using the XFe24 seahorse analyser at baseline and post- treatment with 11B_CC8. The elucidation of the possible mechanism of action of 11B_CC8 was evaluated by Mass-Spectrometry. Results Our novel anti-angiogenic and anti-metabolic agent can enhance radiosensitivity in our isogenic model of OAC under both normoxic and hypoxic (0.5% O 2) conditions. 11B_CC8 significantly reduces oxygen consumption rate (OCR) under normoxic but not hypoxic conditions. Ex-vivo, 11B_CC8 significantly reduced the secretion of IL1β (P = 0.0117). Real-time ex-vivo metabolic rate analysis of our treatment naïve OAC biopsies showed significantly elevated OCR, when compared to Extracellular Acidification rate, a measure of glycolysis (P = 0.0059). Treatment with 11B_CC8 produced a reduction in OCR (P = 0.0039). Conclusion Our novel anti-angiogenic and anti-metabolic agent can enhance radiosensitivity in-vitro under both normoxic and hypoxic conditions. Ex-vivo, treatment naïve OAC human patient samples, 11B_CC8 can significantly reduce the secretion of IL1β and altered metabolic programming, specifically oxidative phosphorylation in human explants. Disclosure All authors have declared no conflicts of interest.

scholarly journals Targeting Bclxl Mitigates Mcl1 Chemoresistance in Multiple Myeloma

Blood ◽  
2021 ◽  
Vol 138 (Supplement 1) ◽  
pp. 2656-2656
Author(s):  
Ioanna Savvidou ◽  
Tiffany Khong ◽  
Irena Carmichael ◽  
Jaynish S Shah ◽  
Sridurga Mithraprabhu ◽  
...  
Keyword(s):  
Multiple Myeloma ◽  
Research Funding ◽  
Ex Vivo ◽  
Combined Treatment ◽  
Live Imaging ◽  
Synergistic Activity ◽  
Protein Levels ◽  
Bax Protein

Abstract Aim: Despite the adoption of novel therapeutic modalities, Multiple Myeloma (MM) remains incurable. The Bcl2 inhibitor Venetoclax is active in several haematologic malignancies, but the benefits in MM patients are limited to those with the t(11;14) and/or high Bcl2 expression. These results underscore the significance of Bcl2 alternative anti-apoptotic proteins (Mcl1 and BclxL) for the survival of myeloma cells. Method: We validated the anti MM effect of the Mcl1 inhibitor S63845 both in vitro utilising 11 human myeloma cell lines (HMCL) and ex vivo against n=30 primary MM tumours. Comparative analysis of RNAseq between S63845 sensitive and resistant HMCL was undertaken to identify candidate proteins that potentially modulate resistance to S63845. Treatment with S63845 and rationally selected combination partners was further evaluated in vitro, ex vivo and in vivo with flow cytometry, immunoblotting and live imaging mitochondria fitness monitoring. Results: RNAseq identified BclxL as potential mediator of resistance to S63845 in HMCL. Immunoblotting confirmed high BclxL expression and high BclxL/BclS in S63845 resistant HMCL. Five S63845 resistant HMCL (U266, ANBL6, KMS28PE, EJM, MM1R) and primary tumours were treated with S63845 combined with the BclxL inhibitor A1331852 . Combined treatment of the HMCL demonstrated a high Bliss synergy score for all the HMCL tested (54, 42, 24, 47, 45 for U266, EJM, KMS28PE, MM1R and ANBL6 respectively) and induced synergistic killing of 80% of the primary tumours treated. Dual inhibition in U266 induced an 80% drop in intracellular ATP at 4h with an increase in active Caspases 9 and 8 (4.5 and 5 fold, respectively). Similarly, the combination induced a 78% drop in mitochondrial transmembrane potential (TMRE intensity) by 4h with live imaging revealing striking mitochondrial damage as early as 40 minutes after exposure (figure). These changes were associated with a reduction of both Mcl1 and, BclxL proteins and Bim and Bid protein levels. No changes were seen in the level of Bcl2, Bak or Bax protein expression. The combination of S63845 and A1331852 in healthy NSG mice at 12.5mg/kg proved lethal due to hepatotoxicity, arguing against the clinical utility of such an approach. However, this observed anti-MM synergistic activity was recapitulated when S63845 was combined with the already approved anti-MM therapeutic panobinostat, with the induction of a significant reduction in both BclxL and Myc protein levels at 24h, and synergistic killing of 56% of primary tumours. Conclusion: High BclxL expression and BclxL/BclxS ratio correlates with resistance to the Mcl1 inhibitor S63845. A combinatorial approach targeting Mcl1 and BclxL induced immediate and significant anti-MM effect both in vitro and ex vivo but proved to be toxic in vivo. Combination of the anti-MM therapeutic panobinostat in combination with S635845 recapitulated the anti-MM activity seen with A1331852 and warrants further evaluation. Figure 1 Figure 1. Disclosures Spencer: Celgene: Honoraria, Research Funding, Speakers Bureau; Janssen: Honoraria, Research Funding, Speakers Bureau; Amgen: Honoraria, Research Funding; Bristol Myers Squibb: Research Funding; Takeda: Honoraria, Research Funding, Speakers Bureau; STA: Honoraria.

scholarly journals 18F-meta-fluorobenzylguanidine (18F-mFBG) to monitor changes in norepinephrine transporter expression in response to therapeutic intervention in neuroblastoma models

2020 ◽  
Vol 10 (1) ◽  
Author(s):  
Stephen Turnock ◽  
David R. Turton ◽  
Carlos Daniel Martins ◽  
Louis Chesler ◽  
Thomas C. Wilson ◽  
...  
Keyword(s):  
Cell Lines ◽  
Ex Vivo ◽  
Norepinephrine Transporter ◽  
Protein Levels ◽  
Positron Emission ◽  
Clinical Interest ◽  
Mibg Therapy ◽  
Mtor Signalling

AbstractTargeted radiotherapy with 131I-mIBG, a substrate of the human norepinephrine transporter (NET-1), shows promising responses in heavily pre-treated neuroblastoma (NB) patients. Combinatorial approaches that enhance 131I-mIBG tumour uptake are of substantial clinical interest but biomarkers of response are needed. Here, we investigate the potential of 18F-mFBG, a positron emission tomography (PET) analogue of the 123I-mIBG radiotracer, to quantify NET-1 expression levels in mouse models of NB following treatment with AZD2014, a dual mTOR inhibitor. The response to AZD2014 treatment was evaluated in MYCN amplified NB cell lines (Kelly and SK-N-BE(2)C) by Western blot (WB) and immunohistochemistry. PET quantification of 18F-mFBG uptake post-treatment in vivo was performed, and data correlated with NET-1 protein levels measured ex vivo. Following 72 h AZD2014 treatment, in vitro WB analysis indicated decreased mTOR signalling and enhanced NET-1 expression in both cell lines, and 18F-mFBG revealed a concentration-dependent increase in NET-1 function. AZD2014 treatment failed however to inhibit mTOR signalling in vivo and did not significantly modulate intratumoural NET-1 activity. Image analysis of 18F-mFBG PET data showed correlation to tumour NET-1 protein expression, while further studies are needed to elucidate whether NET-1 upregulation induced by blocking mTOR might be a useful adjunct to 131I-mIBG therapy.

The Role of Polyphenols in the Modulation of Plasma Non-Enzymatic Antioxidant Capacity (NEAC)

2012 ◽  
Vol 82 (3) ◽  
pp. 228-232 ◽  
Author(s):  
Mauro Serafini ◽  
Giuseppa Morabito
Keyword(s):  
Antioxidant Capacity ◽  
Dietary Intervention ◽  
Ex Vivo ◽  
The Body ◽  
Dietary Polyphenols ◽  
Enzymatic Antioxidant ◽  
Endogenous Antioxidant

Dietary polyphenols have been shown to scavenge free radicals, modulating cellular redox transcription factors in different in vitro and ex vivo models. Dietary intervention studies have shown that consumption of plant foods modulates plasma Non-Enzymatic Antioxidant Capacity (NEAC), a biomarker of the endogenous antioxidant network, in human subjects. However, the identification of the molecules responsible for this effect are yet to be obtained and evidences of an antioxidant in vivo action of polyphenols are conflicting. There is a clear discrepancy between polyphenols (PP) concentration in body fluids and the extent of increase of plasma NEAC. The low degree of absorption and the extensive metabolism of PP within the body have raised questions about their contribution to the endogenous antioxidant network. This work will discuss the role of polyphenols from galenic preparation, food extracts, and selected dietary sources as modulators of plasma NEAC in humans.

Significance of Platelet β-Adrenoceptors for Platelet Responses In Vivo and In Vitro

1992 ◽  
Vol 68 (06) ◽  
pp. 687-693 ◽  
Author(s):  
P T Larsson ◽  
N H Wallén ◽  
A Martinsson ◽  
N Egberg ◽  
P Hjemdahl
Keyword(s):  
Ex Vivo ◽  
High Dose ◽  
Platelet Aggregability ◽  
Adrenoceptor Agonist ◽  
Dose Infusion ◽  
Von Willebrand ◽  
Willebrand Factor ◽  
Factor Antigen

SummaryThe significance of platelet β-adrenoceptors for platelet responses to adrenergic stimuli in vivo and in vitro was studied in healthy volunteers. Low dose infusion of the β-adrenoceptor agonist isoprenaline decreased platelet aggregability in vivo as measured by ex vivo filtragometry. Infusion of adrenaline, a mixed α- and β-adrenoceptor agonist, increased platelet aggregability in vivo markedly, as measured by ex vivo filtragometry and plasma β-thromboglobulin levels. Adrenaline levels were 3–4 nM in venous plasma during infusion. Both adrenaline and high dose isoprenaline elevated plasma von Willebrand factor antigen levels β-Blockade by propranolol did not alter our measures of platelet aggregability at rest or during adrenaline infusions, but inhibited adrenaline-induced increases in vWf:ag. In a model using filtragometry to assess platelet aggregability in whole blood in vitro, propranolol enhanced the proaggregatory actions of 5 nM, but not of 10 nM adrenaline. The present data suggest that β-adrenoceptor stimulation can inhibit platelet function in vivo but that effects of adrenaline at high physiological concentrations are dominated by an α-adrenoceptor mediated proaggregatory action.

In Vivo Effect of Suloctidil as an Antiplatelet Agent

1979 ◽  
Vol 41 (03) ◽  
pp. 465-474 ◽  
Author(s):  
Marcia R Stelzer ◽  
Thomas S Burns ◽  
Robert N Saunders
Keyword(s):  
Ex Vivo ◽  
Antiplatelet Agent ◽  
Ratio Method ◽  
Platelet Aggregate ◽  
Permanent Effect ◽  
Platelet Aggregates ◽  
5 Ht Uptake ◽  
High Doses

SummaryThe relationship between the effects of suloctidil in vivo as an antiplatelet agent and in vitro as a modifier of platelet serotonin (5-HT) parameters was investigated. Suloctidil was found to be effective in reducing platelet aggregates formation in the retired breeder rat as determined using the platelet aggregate ratio method (PAR) with an ED50 of 16.1 mg/kg 24 hours post administration. In contrast to the hypothesis that 5-HT depletion is involved in the anti-aggregatory mechanism of suloctidil, no correlation was found between platelet 5- HT content and this antiplatelet activity. Reduction of platelet 5-HT content required multiple injections of high doses (100 mg/kg/day) of suloctidil. Suloctidil administration for 8 days at 100 mg/kg/day, which lowered platelet 5-HT content by 50%, resulted in no permanent effect on ex vivo platelet 5-HT uptake or thrombin-induced release, nor alteration in the plasma 5-HT level. However, these platelets exhibited a short-lived, significant increase in percent leakage of 5-HT after 30 minutes of incubation. Therefore, suloctidil treatment at high doses may with time result in platelet 5-HT depletion, however this effect is probably not related to the primary anti-aggregatory activity of the drug.

A Comparative Ex Vivo Study of Plasminogen Activators and Proteases for Fibrinolytic Activity and Side Effects in Rabbits

1977 ◽  
Vol 37 (01) ◽  
pp. 154-161 ◽  
Author(s):  
B. A Janik ◽  
S. E Papaioannou
Keyword(s):  
Side Effects ◽  
Effective Dose ◽  
Fibrinolytic Activity ◽  
Ex Vivo ◽  
Plasminogen Activators ◽  
Assay System ◽  
Coagulation Parameters ◽  
Ex Vivo Assay

SummaryUrokinase, streptokinase, Brinase, trypsin, and SN 687, a bacterial exoprotease, have been evaluated in an ex vivo assay system. These enzymes were injected into rabbits and the fibrinolytic activity as well as other coagulation parameters were measured by in vitro techniques. Dose-response correlations have been made using the euglobulin lysis time as a measure of fibrinolytic activity and the 50% effective dose has been determined for each enzyme. Loading doses, equal to four times the 50% effective dose, were administered to monitor potential toxicity revealing that Brinase, trypsin, and SN 687 were very toxic at this concentration.Having established the 50% effective dose for each enzyme, further testing was conducted where relevant fibrinolytic and coagulation parameters were measured for up to two days following a 50% effective dose bolus injection of each enzyme. Our results have demonstrated that urokinase and streptokinase are plasminogen activators specifically activating the rabbit fibrinolytic system while Brinase, trypsin and SN 687 increase the general proteolytic activity in vivo.The advantages of this ex vivo assay system for evaluating relative fibrinolytic potencies and side effects for plasminogen activators and fibrinolytic proteases have been discussed.

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