89 research outputs found
Myocardial production and release of MCP-1 and SDF-1 following myocardial infarction: differences between mice and man
<p>Abstract</p> <p>Background</p> <p>Stem cell homing to the heart is mediated by the release of chemo-attractant cytokines. Stromal derived factor -1 alpha (SDF-1a) and monocyte chemotactic factor 1(MCP-1) are detectable in peripheral blood after myocardial infarction (MI). It remains unknown if they are produced by, and released from, the heart in order to attract stem cells to repair the damaged myocardium.</p> <p>Methods</p> <p>Murine hearts were studied for expression of MCP-1 and SDF-1a at day 3 and day 28 following myocardial infarction to determine whether production is increased following MI. In addition, we studied the coronary artery and coronary sinus (venous) blood from patients with normal coronary arteries, stable coronary artery disease (CAD), unstable angina and MI to determine whether these cytokines are released from the heart into the systemic circulation following MI.</p> <p>Results</p> <p>Both MCP-1 and SDF-1a are constitutively produced and released by the heart. MCP-1 mRNA is upregulated following murine experimental MI, but SDF-1a is suppressed. There is less release of SDF-1a into the systemic circulation in patients with all stages of CAD including MI, mimicking the animal model. However MCP-1 release from the human heart following MI is also suppressed, which is the exact opposite of the animal model.</p> <p>Conclusions</p> <p>SDF-1a and MCP-1 release from the human heart are suppressed following MI. In the case of SDF-1a, the animal model appropriately reflects the human situation. However, for MCP-1 the animal model is the exact opposite of the human condition. Human observational studies like this one are paramount in guiding translation from experimental studies to clinical trials.</p
Effects of a Flaxseed-Derived Lignan Supplement in Type 2 Diabetic Patients: A Randomized, Double-Blind, Cross-Over Trial
Flaxseed consumption has been shown to improve blood lipids in humans and flaxseed-derived lignan has been shown to enhance glycemic control in animals. The study aimed to investigate the effect of a flaxseed-derived lignan supplement on glycemic control, lipid profiles and insulin sensitivity in type 2 diabetic patients.This was a randomized, double-blind, placebo-controlled, cross-over trial and it was conducted between April and December 2006 in Shanghai, China. Seventy-three type 2 diabetic patients with mild hypercholesterolemia were enrolled into the study. Patients were randomized to supplementation with flaxseed-derived lignan capsules (360 mg lignan per day) or placebo for 12 weeks, separated by an 8-week wash-out period. HbA1c, lipid profiles, insulin resistance index and inflammatory factors were measured. Sixty-eight completed the study and were included in the analyses. The lignan supplement significantly improved glycemic control as measured by HbA(1c) (-0.10+/-0.65 % vs. 0.09+/-0.52 %, P = 0.001) compared to placebo; however, no significant changes were observed in fasting glucose and insulin concentrations, insulin resistance and blood lipid profiles. Urinary excretion of lignan metabolites (enterodiol and enterolactone) was significantly higher after the lignan supplement intervention compared to baseline (14.2+/-18.1 vs. 1.2+/-2.4 microg/mL, P<0.001). Data also suggested minimal competition between lignan and isoflavones for bioavailability when measured by the excretion concentrations.Daily lignan supplementation resulted in modest, yet statistically significant improvements in glycemic control in type 2 diabetic patients without apparently affecting fasting glucose, lipid profiles and insulin sensitivity. Further studies are needed to validate these findings and explore the efficacy of lignans on type 2 diabetes.ClinicalTrials.gov NCT00363233
Polysaccharides from the root of Angelica sinensis promotes hematopoiesis and thrombopoiesis through the PI3K/AKT pathway
<p>Abstract</p> <p>Background</p> <p>Dozens of Traditional Chinese Medicine (TCM) formulas have been used for promotion of "blood production" for centuries, and we are interested in developing novel thrombopoietic medicines from these TCMs. Our previous studies have demonstrated the hematopoietic effects of DangGui BuXue Tong (DBT), a formula composed of <it>Radix Angelicae Sinensis </it>and <it>Radix Astragali </it>in animal and cellular models. As a step further to identify and characterize the active chemical components of DBT, we tested the hematopoietic and particularly, thrombopoietic effects of polysaccharide-enriched fractions from the root of <it>Radix Angelicae Sinensis </it>(APS) in this study.</p> <p>Methods</p> <p>A myelosuppression mouse model was treated with APS (10 mg/kg/day). Peripheral blood cells from APS, thrombopoietin and vehicle-treated samples were then counted at different time-points. Using the colony-forming unit (CFU) assays, we determined the effects of APS on the proliferation and differentiation of hematopoietic stem/progenitor cells and megakaryocytic lineages. Using a megakaryocytic cell line M-07e as model, we analyzed the cellular apoptosis progression with and without APS treatment by Annexin V, Mitochondrial Membrane Potential and Caspase 3 assays. Last, the anti-apoptotic effect of APS on cells treated with Ly294002, a Phosphatidylinositol 3-Kinse inhibitor (PI3K) was also tested.</p> <p>Results</p> <p>In animal models, APS significantly enhanced not only the recovery of platelets, other blood cells and their progenitor cells, but also the formation of Colony Forming Unit (CFU). In M-07e cells, we observed the anti-apoptotic effect of APS. Treatment by Ly294002 alone increased the percentage of cells undergoing apoptosis. However, addition of APS to Ly294002-treated cells significantly reduced the percentage of cells undergoing apoptosis.</p> <p>Conclusions</p> <p>APS promotes hematopoiesis and thrombopoiesis in the mouse model. This effect likely resulted from the anti-apoptosis activity of APS and is likely to involve the PI3K/AKT pathway.</p
Design and baseline characteristics of the finerenone in reducing cardiovascular mortality and morbidity in diabetic kidney disease trial
Background: Among people with diabetes, those with kidney disease have exceptionally high rates of cardiovascular (CV) morbidity and mortality and progression of their underlying kidney disease. Finerenone is a novel, nonsteroidal, selective mineralocorticoid receptor antagonist that has shown to reduce albuminuria in type 2 diabetes (T2D) patients with chronic kidney disease (CKD) while revealing only a low risk of hyperkalemia. However, the effect of finerenone on CV and renal outcomes has not yet been investigated in long-term trials.
Patients and Methods: The Finerenone in Reducing CV Mortality and Morbidity in Diabetic Kidney Disease (FIGARO-DKD) trial aims to assess the efficacy and safety of finerenone compared to placebo at reducing clinically important CV and renal outcomes in T2D patients with CKD. FIGARO-DKD is a randomized, double-blind, placebo-controlled, parallel-group, event-driven trial running in 47 countries with an expected duration of approximately 6 years. FIGARO-DKD randomized 7,437 patients with an estimated glomerular filtration rate >= 25 mL/min/1.73 m(2) and albuminuria (urinary albumin-to-creatinine ratio >= 30 to <= 5,000 mg/g). The study has at least 90% power to detect a 20% reduction in the risk of the primary outcome (overall two-sided significance level alpha = 0.05), the composite of time to first occurrence of CV death, nonfatal myocardial infarction, nonfatal stroke, or hospitalization for heart failure.
Conclusions: FIGARO-DKD will determine whether an optimally treated cohort of T2D patients with CKD at high risk of CV and renal events will experience cardiorenal benefits with the addition of finerenone to their treatment regimen.
Trial Registration: EudraCT number: 2015-000950-39; ClinicalTrials.gov identifier: NCT02545049
Face-Centered-Cubic Large-Pore Periodic Mesoporous Organosilicas with Unsaturated and Aromatic Bridging Groups
Large-pore ethenylene-bridged (−CHCH−)
and
phenylene-bridged (−C<sub>6</sub>H<sub>4</sub>−) periodic
mesoporous organosilicas (PMOs) with face-centered-cubic structure
(<i>Fm</i>3<i>m</i> symmetry) of spherical mesopores
were synthesized at 7 °C at low acid concentration (0.1 M HCl)
using Pluronic F127 triblock copolymer surfactant in the presence
of aromatic swelling agents (1,3,5-trimethylbenzene, xylenes–isomer
mixture, and toluene). In particular, this work reports an unprecedented
block-copolymer-templated well-ordered ethenylene-bridged PMO with
cubic structure of spherical mesopores and an unprecedented block-copolymer-templated
face-centered cubic phenylene-bridged PMO, which also has an exceptionally
large unit-cell size and pore diameter. The unit-cell parameters of
30 and 25 nm and the mesopore diameters of 14 and 11 nm (nominal BJH-KJS
pore diameters of 12–13 and 9 nm) were obtained for ethenylene-bridged
and phenylene-bridged PMOs, respectively. Under the considered reaction
conditions, the unit-cell parameters and pore diameters were found
to be similar when the three different methyl-substituted benzene
swelling agents were employed, although the degree of structural ordering
appeared to improve for phenylene-bridged PMOs in the sequence of
decreased number of methyl groups on the benzene ring
Upregulation of Urotensin II receptor in preeclampsia causes in vitro placental release of soluble vascular endothelial growth factor receptor 1 in hypoxia
Preeclampsia is a hypertensive disorder of pregnancy caused by abnormal placental function, partly because of chronic hypoxia at the utero-placental junction. The increase in levels of soluble vascular endothelial growth factor receptor 1, an antiangiogenic agent known to inhibit placental vascularization, is an important cellular factor implicated in the onset of preeclampsia. We investigated the ligand urotensin II (U-II), a potent endogenous vasoconstrictor and proangiogenic agent, for which levels have been reported to increase in patients with preeclampsia. We hypothesized that an increased sensitivity to U-II in preeclampsia might be achieved by upregulation of placental U-II receptors. We further investigated the role of U-II receptor stimulation on soluble vascular endothelial growth factor receptor 1 release in placental explants from diseased and normal patients. Immunohistochemistry, real-time PCR, and Western blotting analysis revealed that U-II receptor expression was significantly upregulated in preeclampsia placentas compared with controls (P < 0.01). Cellular models of syncytiotrophoblast and vascular endothelial cells subjected to hypoxic conditions revealed an increase in U-II receptor levels in the syncytiotrophoblast model. This induction is regulated by the transcriptional activator hypoxia-inducible factor 1 alpha. U-II treatment is associated with increased secretion of soluble vascular endothelial growth factor receptor 1 only in preeclamptic placental explants under hypoxia but not in control conditions. Interestingly, normal placental explants did not respond to U-II stimulation. (Hypertension. 2010; 56: 172-178.
Aging Impairs the Proliferative Capacity of Cardiospheres, Cardiac Progenitor Cells and Cardiac Fibroblasts: Implications for Cell Therapy
Introduction: Cardiospheres (CS) are self-assembling clusters of cells that can be grown from cardiac tissue. They contain a heterogeneous cell population that includes cardiac progenitor cells (CPCs) and cardiac fibroblasts. CS and CPCs have been shown to improve cardiac function after myocardial infarction (MI) in experimental models and are now being studied in clinical trials. The effects of aging on the proliferative capacity of CS and CPCs, and the paracrine signaling between cell types, remain incompletely understood. Methods and Results: We compared the growth of CS from young and aging murine hearts at baseline and following MI. The number of CS from young and aging hearts was similar at baseline. However, after MI, young hearts had a dramatic increase in the number of CS that grew, but this proliferative response to MI was virtually abolished in the aging heart. Further, the proportion of cells within the CS that were CPCs (defined as Sca-1(stem cell antigen-1)+/CD45−) was significantly lower in aging hearts than young hearts. Thus the number of available CPCs after culture from aging hearts was substantially lower than from young hearts. Cardiac fibroblasts from aging hearts proliferated more slowly in culture than those from young hearts. We then investigated the interaction between aging cardiac fibroblasts and CPCs. We found no significant paracrine effects on proliferation between these cell types, suggesting the impaired proliferation is a cell-autonomous problem. Conclusions: Aging hearts generate fewer CPCs, and aging CPCs have significantly reduced proliferative potential following MI. Aging cardiac fibroblasts also have reduced proliferative capacity, but these appear to be cell-autonomous problems, not caused by paracrine signaling between cell types
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