scholarly journals Antileishmanial activity of synthetic analogs of the naturally occurring quinolone alkaloid N-methyl-8-methoxyflindersin

PLoS ONE ◽  
2020 ◽  
Vol 15 (12) ◽  
pp. e0243392
Author(s):  
Elaine Torres Suarez ◽  
Diana Susana Granados-Falla ◽  
Sara María Robledo ◽  
Javier Murillo ◽  
Yulieth Upegui ◽  
...  
Keyword(s):  
Ex Vivo ◽  
Human Peripheral Blood ◽  
Peripheral Blood Monocyte ◽  
Synthetic Compounds ◽  
Antiparasitic Activity ◽  
Ultrastructural Alterations ◽  
Quinoline Alkaloids ◽  
Induced Apoptosis

Leishmaniasis is a neglected, parasitic tropical disease caused by an intracellular protozoan from the genus Leishmania. Quinoline alkaloids, secondary metabolites found in plants from the Rutaceae family, have antiparasitic activity against Leishmania sp. N-methyl-8-methoxyflindersin (1), isolated from the leaves of Raputia heptaphylla and also known as 7-methoxy-2,2-dimethyl-2H,5H,6H-pyran[3,2-c]quinolin-5-one, shows antiparasitic activity against Leishmania promastigotes and amastigotes. This study used in silico tools to identify synthetic quinoline alkaloids having structure similar to that of compound 1 and then tested these quinoline alkaloids for their in vitro antiparasitic activity against Leishmania (Viannia) panamensis, in vivo therapeutic response in hamsters suffering from experimental cutaneous leishmaniasis (CL), and ex vivo immunomodulatory potential in healthy donors’ human peripheral blood (monocyte)-derived macrophages (hMDMs). Compounds 1 (natural), 2 (synthetic), and 8 (synthetic) were effective against intracellular promastigotes (9.9, 3.4, and 1.6 μg/mL medial effective concentration [EC50], respectively) and amastigotes (5.07, 7.94, and 1.91 μg/mL EC50, respectively). Compound 1 increased nitric oxide production in infected hMDMs and triggered necrosis-related ultrastructural alterations in intracellular amastigotes, while compound 2 stimulated oxidative breakdown in hMDMs and caused ultrastructural alterations in the parasite 4 h posttreatment, and compound 8 failed to induce macrophage modulation but selectively induced apoptosis of infected hMDMs and alterations in the intracellular parasite ultrastructure. In addition, synthetic compounds 2 and 8 improved the health of hamsters suffering from experimental CL, without evidence of treatment-associated adverse toxic effects. Therefore, synthetic compounds 2 and 8 are potential therapeutic candidates for topical treatment of CL.

scholarly journals JAK/STAT pathway inhibition sensitizes CD8 T cells to dexamethasone-induced apoptosis in hyperinflammation

Blood ◽  
2020 ◽  
Vol 136 (6) ◽  
pp. 657-668 ◽  
Author(s):  
Lauren K. Meyer ◽  
Katherine C. Verbist ◽  
Sabrin Albeituni ◽  
Brooks P. Scull ◽  
Rachel C. Bassett ◽  
...  
Keyword(s):  
T Cells ◽  
Cd8 T Cells ◽  
Ex Vivo ◽  
Lymphoblastic Leukemia ◽  
Immune System Activation ◽  
Stat Signaling ◽  
Induced Apoptosis ◽  
Stat Pathway

Abstract Cytokine storm syndromes (CSS) are severe hyperinflammatory conditions characterized by excessive immune system activation leading to organ damage and death. Hemophagocytic lymphohistiocytosis (HLH), a disease often associated with inherited defects in cell-mediated cytotoxicity, serves as a prototypical CSS for which the 5-year survival is only 60%. Frontline therapy for HLH consists of the glucocorticoid dexamethasone (DEX) and the chemotherapeutic agent etoposide. Many patients, however, are refractory to this treatment or relapse after an initial response. Notably, many cytokines that are elevated in HLH activate the JAK/STAT pathway, and the JAK1/2 inhibitor ruxolitinib (RUX) has shown efficacy in murine HLH models and humans with refractory disease. We recently reported that cytokine-induced JAK/STAT signaling mediates DEX resistance in T cell acute lymphoblastic leukemia (T-ALL) cells, and that this could be effectively reversed by RUX. On the basis of these findings, we hypothesized that cytokine-mediated JAK/STAT signaling might similarly contribute to DEX resistance in HLH, and that RUX treatment would overcome this phenomenon. Using ex vivo assays, a murine model of HLH, and primary patient samples, we demonstrate that the hypercytokinemia of HLH reduces the apoptotic potential of CD8 T cells leading to relative DEX resistance. Upon exposure to RUX, this apoptotic potential is restored, thereby sensitizing CD8 T cells to DEX-induced apoptosis in vitro and significantly reducing tissue immunopathology and HLH disease manifestations in vivo. Our findings provide rationale for combining DEX and RUX to enhance the lymphotoxic effects of DEX and thus improve the outcomes for patients with HLH and related CSS.

scholarly journals Nivalenol induced apoptosis in human peripheral blood lymphocytes in vitro and mouse peripheral blood lymphocytes in vivo

1997 ◽  
Vol 1997 (45) ◽  
pp. 33-37 ◽  
Author(s):  
Naoto YOSHINO ◽  
Mari TAKIZAWA ◽  
Hiroki OKUMURA ◽  
Tomomi IHARA ◽  
Masao SUGAMATA ◽  
...  
Keyword(s):  
Peripheral Blood ◽  
Human Peripheral Blood ◽  
Peripheral Blood Lymphocytes ◽  
Blood Lymphocytes ◽  
Human Peripheral Blood Lymphocytes ◽  
Induced Apoptosis

DNA damage and susceptibility to oxidative damage in lymphocytes: effects of carotenoidsin vitroandin vivo

2004 ◽  
Vol 91 (1) ◽  
pp. 53-61 ◽  
Author(s):  
Siân B. Astley ◽  
David A. Hughes ◽  
Anthony J. A. Wright ◽  
Ruan M. Elliott ◽  
Susan Southon
Keyword(s):  
Oxidative Damage ◽  
Ex Vivo ◽  
Human Peripheral Blood ◽  
Plasma Concentrations ◽  
Peripheral Blood Lymphocytes ◽  
Repair Mechanisms ◽  
Oxidative Challenge ◽  
Β Carotene

Reports on the effects of carotenoids are conflicting. The present paper examines similarities and differences from contiguous studiesin vitroandin vivo. Single-cell gel electrophoresis was used to measure the frequency of single-strand breaks (SSB) in the cell line MOLT-17 (as a model system) and human peripheral blood lymphocytes (PBL). MOLT-17 cells were supplemented with β-carotene, lutein or lycopene at a range of concentrations (0·00–8·00 μmol/l) using a liposome delivery method. Uptake was dose-dependent. β-Carotene concentration in the media had no effect on SSB in control cells, but incubation with lycopene or lutein (>2·00 μmol/l) increased the numbers of SSB in control cells. MOLT-17 DNA was less susceptible to oxidative damage (100 μmol H2O2/l, 5 min, 4 °C) following incubation with carotenoids between 0·50 and 1·00 μmol/l; at >1·00 μmol/l the effects were ambiguous. Apparently healthy male volunteers supplemented their habitual diets with lutein, β-carotene or lycopene (natural isolate capsules, 15 mg/d, 4 weeks) in three independent studies, raising plasma concentrations to different extents. Lycopene and lutein had no effect on SSB in control PBL or following oxidative challenge. However, increased plasma β-carotene was associated with more SSB in control cells whilst PBL DNA resistance to oxidative damageex vivowas unaffected. These results suggest that the carotenoids are capable of exerting two overlapping but distinct effects: antioxidant protection by scavenging DNA-damaging free radicals and modulation of DNA repair mechanisms.

scholarly journals Role of RIPK1 in SMAC mimetics-induced apoptosis in primary human HIV-infected macrophages

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Ramon Edwin Caballero ◽  
Simon Xin Min Dong ◽  
Niranjala Gajanayaka ◽  
Hamza Ali ◽  
Edana Cassol ◽  
...  
Keyword(s):  
Cell Death ◽  
Hiv Infection ◽  
Ex Vivo ◽  
Laboratory Strain ◽  
Interacting Protein ◽  
Heat Stable Antigen ◽  
Smac Mimetics ◽  
Induced Apoptosis

AbstractMacrophages serve as viral reservoirs due to their resistance to apoptosis and HIV-cytopathic effects. We have previously shown that inhibitor of apoptosis proteins (IAPs) confer resistance to HIV-Vpr-induced apoptosis in normal macrophages. Herein, we show that second mitochondrial activator of caspases (SMAC) mimetics (SM) induce apoptosis of monocyte-derived macrophages (MDMs) infected in vitro with a R5-tropic laboratory strain expressing heat stable antigen, chronically infected U1 cells, and ex-vivo derived MDMs from HIV-infected individuals. To understand the mechanism governing SM-induced cell death, we show that SM-induced cell death of primary HIV-infected macrophages was independent of the acquisition of M1 phenotype following HIV infection of macrophages. Instead, SM-induced cell death was found to be mediated by IAPs as downregulation of IAPs by siRNAs induced cell death of HIV-infected macrophages. Moreover, HIV infection caused receptor interacting protein kinase-1 (RIPK1) degradation which in concert with IAP1/2 downregulation following SM treatment may result in apoptosis of macrophages. Altogether, our results show that SM selectively induce apoptosis in primary human macrophages infected in vitro with HIV possibly through RIPK1. Moreover, modulation of the IAP pathways may be a potential strategy for selective killing of HIV-infected macrophages in vivo.

scholarly journals Synergistic Antitumour Properties ofviscumTTin Alveolar Rhabdomyosarcoma

2017 ◽  
Vol 2017 ◽  
pp. 1-13 ◽  
Author(s):  
Rahel Mascha Stammer ◽  
Susann Kleinsimon ◽  
Jana Rolff ◽  
Sebastian Jäger ◽  
Angelika Eggert ◽  
...  
Keyword(s):  
Ex Vivo ◽  
Viscum Album ◽  
Tumour Volume ◽  
Dependent Manner ◽  
Mistletoe Extract ◽  
Antiapoptotic Proteins ◽  
Cytotoxic Compounds ◽  
Induced Apoptosis

Aqueous mistletoe extracts from the European mistletoe (Viscum album) contain mainly mistletoe lectins and viscotoxins as cytotoxic compounds. Lipophilic triterpene acids, which do not occur in conventional mistletoe preparations, were solubilised withβ-cyclodextrins. The combination of an aqueous extract (viscum) and a triterpene-containing extract (TT) recreated a whole mistletoe extract (viscumTT). These extracts were tested on rhabdomyosarcoma in vitro, ex vivo, and in vivo with regard to anticancer effects.ViscumandviscumTTinhibited cell proliferation and induced apoptosis effectively in a dose-dependent manner in vitro and ex vivo, whereasTTshowed only moderate inhibitory effects.viscumTTproved to be more effective than the single extracts and displayed a synergistic effect in vitro and a stronger effect in vivo.viscumTTinduced apoptosis via the extrinsic and intrinsic pathways, evidenced by the loss of mitochondrial membrane potential and activation of CASP8 and CASP9. CASP10 inhibitor inhibited apoptosis effectively, emphasising the importance of CASP10 inviscumTT-induced apoptosis. Additionally,viscumTTchanged the ratio of apoptosis-associated proteins by downregulation of antiapoptotic proteins such as XIAP and BIRC5, thus shifting the balance towards apoptosis.viscumTTeffectively reduced tumour volume in patient-derived xenografts in vivo and may be considered a promising substance for rhabdomyosarcoma therapy.

scholarly journals Inhibitor of apoptosis, IAP, genes play a critical role in the survival of HIV-infected macrophages

2019 ◽  
Author(s):  
Ashok Kumar ◽  
Ramon Edwin Hernandez Caballero ◽  
Simon Xin Min Dong ◽  
Niranjala Gajanayaka ◽  
Hamza Ali ◽  
...  
Keyword(s):  
Ex Vivo ◽  
Critical Role ◽  
Laboratory Strain ◽  
Inhibitor Of Apoptosis ◽  
Viral Reservoirs ◽  
Interacting Protein ◽  
Heat Stable Antigen ◽  
Induced Apoptosis

Latent viral reservoirs of HIV-1 that persist despite antiretroviral therapy (ART) are major barriers for a successful cure. Macrophages serve as viral reservoirs due to their resistance to apoptosis and HIV-cytopathic effects. We have previously shown that inhibitor of apoptosis proteins (IAPs) confer resistance to HIV-Vpr-induced apoptosis in normal macrophages. Herein, we show that second mitochondrial activator of caspases (SMAC)-mimetics (SM) specifically induce apoptosis of monocyte-derived macrophages (MDMs) infected in vitro with a R5-tropic laboratory strain expressing heat stable antigen, and GFP-expressing HIV, chronically infected U1 cells, and ex-vivo derived MDMs from naïve and ART-treated HIV patients. SM-induced cell death was found to be mediated by IAPs using IAP siRNAs, was independent of endogenously produced TNFα and was attributed to the concomitant downregulation of IAP-1/2 and the receptor interacting protein kinase-1 degradation following HIV infection. Altogether, modulation of the IAP pathways may be a potential strategy for selective killing of HIV-infected macrophages in vivo.

scholarly journals Adeno-Associated Virus Type 2-Mediated Transduction of Human Monocyte-Derived Dendritic Cells: Implications for Ex Vivo Immunotherapy

2001 ◽  
Vol 75 (19) ◽  
pp. 9493-9501 ◽  
Author(s):  
Selvarangan Ponnazhagan ◽  
Gandham Mahendra ◽  
David T. Curiel ◽  
Denise R. Shaw
Keyword(s):  
Dendritic Cells ◽  
Immune Responses ◽  
Transgene Expression ◽  
Ex Vivo ◽  
Human Peripheral Blood ◽  
Adeno Associated Virus ◽  
Dc Vaccine

ABSTRACT Dendritic cells (DCs) are pivotal antigen-presenting cells for regulating immune responses. A major focus of contemporary vaccine research is the genetic modification of DCs to express antigens or immunomodulatory molecules, utilizing a variety of viral and nonviral vectors, to induce antigen-specific immune responses that ameliorate disease states as diverse as malignancy, infection, autoimmunity, and allergy. The present study has evaluated adeno-associated virus (AAV) type 2 as a vector for ex vivo gene transfer to human peripheral blood monocyte (MO)-derived DCs. AAV is a nonpathogenic parvovirus that infects a wide variety of human cell lineages in vivo and in vitro, for long-term transgene expression without requirements for cell proliferation. The presented data demonstrate that recombinant AAV (rAAV) can efficiently transduce MOs as well as DCs generated by MO culture with granulocyte-macrophage colony-stimulating factor plus interleukin in vitro. rAAV transgene expression in MO-derived DCs could be enhanced by etoposide, previously reported to enhance AAV gene expression. rAAV transduction of freshly purified MO followed by 7 days of culture with cytokines to generate DCs, and subsequent sorting for coexpression of DC markers CD1a and CD40, showed robust transgene expression as well as evidence of nuclear localization of the rAAV genome in the DC population. Phenotypic analyses using multiple markers and functional assays of one-way allogeneic mixed leukocyte reactions indicated that rAAV-transduced MO-derived DCs were as equivalent to nontransduced DCs. These results support the utility of rAAV vectors for future human DC vaccine studies.

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.

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