Primary cytotoxic responses in macrocultures against UV-treated stimulator cells or glutaraldehyde-fixed stimulator cells in the presence of third party stimulator cells were studied to investigate ...whether metabolically active stimulator cells are only required for the activation of interleukin 2-producing helper cells. Cultures containing splenic responder cells in a mixture with allogeneic UV-treated stimulator cells of a mouse strain X plus conventional (i.e., only lambda -irradiated) stimulator cells of a third strain Y were found to generate strong cytotoxic activity against cells of strain Y but not strain X. The results provide suggestive evidence that CTL precursor cells are optimally activated in primary cytotoxic responses when their receptors interact with antigen on metabolically active stimulator cells. The experiments excluded the possibility that the metabolically active stimulator cells were only required for the activation of an unlinked helper effect (i.e., for the stimulation of interleukin 2 production) because the response against the third party stimulator cell proceeded in the same culture at normal magnitude. Cultures that received UV-treated stimulator cells on day 0 and an optimal dose of corresponding conventional stimulator cells on day 2 generated still weaker cytotoxicity than control cultures with conventional stimulator cells on day 0, indicating that the metabolically active (UV-sensitive) stimulator cells were required in the early phase of the culture to achieve optimal cytotoxic responses.
Plastic-adherent cells enriched for dendritic cells (AC) were found to be among the most potent stimulator cells for the activation of cytotoxic T lymphocytes (CTL) in vitro in the presence of ...interleukin 2 (IL 2) and a constant second set of allogeneic stimulator cells. Concanavalin A-activated nylon wool-nonadherent spleen cells ( CNWT ), concanavalin A-activated unfractionated spleen cells ( Cspl ), and some variants of the ESb T lymphoma line were equally effective as stimulator cells, however, and provoked a substantial cytotoxic response at concentrations of 10(4) cells per culture or less. In contrast, nonactivated nylon wool-nonadherent spleen cells ( NWT ) or unfractionated spleen cells (Spl) and cells of the P815 mastocytoma, the Meth A fibrosarcoma, and the T cell lymphomas Ly 5178 Eb and ESb did not stimulate cytotoxic responses at these cell concentrations. The strong stimulatory potential of the Cspl preparation was reduced by treatment with anti-Thy-1 antibody plus complement, whereas the stimulatory activity of the AC preparation was resistant to this treatment. All cell types tested expressed class I major histocompatibility antigens. Nonactivated NWT cells, in contrast to the CNWT preparation, showed no detectable staining with anti-I-E or anti-I-A antibodies and also a slightly weaker staining with class I antisera. Experiments with the tumor cell lines revealed, however, that there was no strict correlation between stimulatory potential and density of class I alloantigens or the expression of I-E determinants. Experiments on primary cytotoxic responses in vivo gave similar results. Experiments in cultures with a single set of stimulator cells and I region-compatible responder cells indicated that AC and Cspl or CNWT also have a markedly stronger capacity than NWT to induce IL 2-dependent DNA synthesis.
Medicinal properties of turmeric (
L.), a plant used for centuries as an anti-inflammatory, are attributed to its polyphenolic curcuminoids, where curcumin predominates. Although "curcumin" ...supplements are a top-selling botanical with promising pre-clinical effects, questions remain regarding biological activity in humans. To address this, a scoping review was conducted to assess human clinical trials reporting oral curcumin effects on disease outcomes. Eight databases were searched using established guidelines, yielding 389 citations (from 9528 initial) that met inclusion criteria. Half focused on obesity-associated metabolic disorders (29%) or musculoskeletal disorders (17%), where inflammation is a key driver, and beneficial effects on clinical outcomes and/or biomarkers were reported for most citations (75%) in studies that were primarily double-blind, randomized, and placebo-controlled trials (77%, D-RCT). Citations for the next most studied disease categories (neurocognitive 11% or gastrointestinal disorders 10%, or cancer 9%), were far fewer in number and yielded mixed results depending on study quality and condition studied. Although additional research is needed, including systematic evaluation of diverse curcumin formulations and doses in larger D-RCT studies, the preponderance of current evidence for several highly studied diseases (e.g., metabolic syndrome, osteoarthritis), which are also clinically common, are suggestive of clinical benefits.
Recent clinical evidence identified anemia to be correlated with severe complications of cardiovascular disease (CVD) such as bleeding, thromboembolic events, stroke, hypertension, arrhythmias, and ...inflammation, particularly in elderly patients. The underlying mechanisms of these complications are largely unidentified. Recent Advances: Previously, red blood cells (RBCs) were considered exclusively as transporters of oxygen and nutrients to the tissues. More recent experimental evidence indicates that RBCs are important interorgan communication systems with additional functions, including participation in control of systemic nitric oxide metabolism, redox regulation, blood rheology, and viscosity. In this article, we aim to revise and discuss the potential impact of these noncanonical functions of RBCs and their dysfunction in the cardiovascular system and in anemia.
The mechanistic links between changes of RBC functional properties and cardiovascular complications related to anemia have not been untangled so far.
To allow a better understanding of the complications associated with anemia in CVD, basic and translational science studies should be focused on identifying the role of noncanonical functions of RBCs in the cardiovascular system and on defining intrinsic and/or systemic dysfunction of RBCs in anemia and its relationship to CVD both in animal models and clinical settings. Antioxid. Redox Signal. 26, 718-742.
Endothelial dysfunction is associated with decreased NO bioavailability and impaired activation of the NO receptor soluble guanylate cyclase (sGC) in the vasculature and in platelets. Red blood cells ...(RBCs) are known to produce NO under hypoxic and normoxic conditions; however evidence of expression and/or activity of sGC and downstream signaling pathway including phopshodiesterase (PDE)-5 and protein kinase G (PKG) in RBCs is still controversial. In the present study, we aimed to investigate whether RBCs carry a functional sGC signaling pathway and to address whether this pathway is compromised in coronary artery disease (CAD). Using two independent chromatographic procedures, we here demonstrate that human and murine RBCs carry a catalytically active α1β1-sGC (isoform 1), which converts 32P-GTP into 32P-cGMP, as well as PDE5 and PKG. Specific sGC stimulation by NO+BAY 41-2272 increases intracellular cGMP-levels up to 1000-fold with concomitant activation of the canonical PKG/VASP-signaling pathway. This response to NO is blunted in α1-sGC knockout (KO) RBCs, but fully preserved in α2-sGC KO. In patients with stable CAD and endothelial dysfunction red cell eNOS expression is decreased as compared to aged-matched controls; by contrast, red cell sGC expression/activity and responsiveness to NO are fully preserved, although sGC oxidation is increased in both groups. Collectively, our data demonstrate that an intact sGC/PDE5/PKG-dependent signaling pathway exists in RBCs, which remains fully responsive to NO and sGC stimulators/activators in patients with endothelial dysfunction. Targeting this pathway may be helpful in diseases with NO deficiency in the microcirculation like sickle cell anemia, pulmonary hypertension, and heart failure.
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•Human and murine RBCs carry catalytically active α1β1-sGC (isoform 1), PKG and PDE5.•NO-stimulation increases cGMP-levels in intact RBCs in a sGC and PDE-dependent manner,•NO stimulation induces canonical PKG/VASP-dependent signaling.•NO responsiveness of red cell sGC is blunted in α1-sGC KO mice, but is preserved in α2-sGC KO and eNOS KO mice.•Red cell sGC activity is fully preserved in patients with stable coronary artery disease.
Mutations in codon 132 of
isocitrate dehydrogenase
(
IDH
)
1
are frequent in diffuse glioma, acute myeloid leukemia, chondrosarcoma and intrahepatic cholangiocarcinoma. These mutations result in a ...neomorphic enzyme specificity which leads to a dramatic increase of intracellular
d
-2-hydroxyglutarate (2-HG) in tumor cells. Therefore, mutant IDH1 protein is a highly attractive target for inhibitory drugs. Here, we describe the development and properties of BAY 1436032, a pan-inhibitor of IDH1 protein with different codon 132 mutations. BAY 1436032 strongly reduces 2-HG levels in cells carrying IDH1-R132H, -R132C, -R132G, -R132S and -R132L mutations. Cells not carrying
IDH
mutations were unaffected. BAY 1436032 did not exhibit toxicity in vitro or in vivo. The pharmacokinetic properties of BAY 1436032 allow for oral administration. In two independent experiments, BAY 1436032 has been shown to significantly prolong survival of mice intracerebrally transplanted with human astrocytoma carrying the IDH1R132H mutation. In conclusion, we developed a pan-inhibitor targeting tumors with different IDH1R132 mutations.
Neomorphic mutations in isocitrate dehydrogenase 1 (IDH1) are frequently found in several human cancer types including acute myeloid leukemia (AML) and lead to the production of high levels of the ...oncometabolite (R)-2-hydroxyglutarate (R-2HG). Here we report the characterization of BAY1436032, a novel pan-mutant IDH1 inhibitor, both in vitro and in vivo. BAY1436032 specifically inhibits R-2HG production and colony growth, and induces myeloid differentiation of AML cells carrying IDH1R132H, IDH1R132C, IDH1R132G, IDH1R132L and IDH1R132S mutations. In addition, the compound impacts on DNA methylation and attenuates histone hypermethylation. Oral administration of BAY1436032 led to leukemic blast clearance, myeloid differentiation, depletion of leukemic stem cells and prolonged survival in two independent patient-derived xenograft IDH1 mutant AML mouse models. Together, BAY1436032 is highly effective against all major types of IDH1 mutant AML.
Stress and Rest Dynamic Myocardial Perfusion Imaging by Evaluation of Complete Time-Attenuation Curves With Dual-Source CT Kheng-Thye Ho, Kia-Chong Chua, Ernst Klotz, Christoph Panknin The evaluation ...of coronary artery disease by computed tomography has so far largely been limited to the visualization of coronary arteries and detection of stenoses. Recently, it has been suggested that contrast-enhanced computed tomography imaging under pharmacological stress may be able to visualize regional perfusion defects in patients with coronary artery disease. This article presents a new approach for data acquisition of computed tomography myocardial perfusion imaging with time-resolved visualization of perfusion. At acceptable radiation and contrast doses, the technique allows dynamic assessment of myocardial perfusion with absolute quantification of blood flow, and a close correlation to traditional single-photon emission computed tomography myocardial perfusion imaging.
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