Although metabolic risk factors are known to cluster in individuals who are prone to developing diabetes mellitus and cardiovascular disease, the underlying biological mechanisms remain poorly ...understood.
To identify pathways associated with cardiometabolic risk, we used liquid chromatography/mass spectrometry to determine the plasma concentrations of 45 distinct metabolites and to examine their relation to cardiometabolic risk in the Framingham Heart Study (FHS; n=1015) and the Malmö Diet and Cancer Study (MDC; n=746). We then interrogated significant findings in experimental models of cardiovascular and metabolic disease. We observed that metabolic risk factors (obesity, insulin resistance, high blood pressure, and dyslipidemia) were associated with multiple metabolites, including branched-chain amino acids, other hydrophobic amino acids, tryptophan breakdown products, and nucleotide metabolites. We observed strong associations of insulin resistance traits with glutamine (standardized regression coefficients, -0.04 to -0.22 per 1-SD change in log-glutamine; P<0.001), glutamate (0.05 to 0.14; P<0.001), and the glutamine-to-glutamate ratio (-0.05 to -0.20; P<0.001) in the discovery sample (FHS); similar associations were observed in the replication sample (MDC). High glutamine-to-glutamate ratio was associated with lower risk of incident diabetes mellitus in FHS (odds ratio, 0.79; adjusted P=0.03) but not in MDC. In experimental models, administration of glutamine in mice led to both increased glucose tolerance (P=0.01) and decreased blood pressure (P<0.05).
Biochemical profiling identified circulating metabolites not previously associated with metabolic traits. Experimentally interrogating one of these pathways demonstrated that excess glutamine relative to glutamate, resulting from exogenous administration, is associated with reduced metabolic risk in mice.
We developed a pipeline to integrate the proteomic technologies used from the discovery to the verification stages of plasma biomarker identification and applied it to identify early biomarkers of ...cardiac injury from the blood of patients undergoing a therapeutic, planned myocardial infarction (PMI) for treatment of hypertrophic cardiomyopathy. Sampling of blood directly from patient hearts before, during and after controlled myocardial injury ensured enrichment for candidate biomarkers and allowed patients to serve as their own biological controls. LC-MS/MS analyses detected 121 highly differentially expressed proteins, including previously credentialed markers of cardiovascular disease and >100 novel candidate biomarkers for myocardial infarction (MI). Accurate inclusion mass screening (AIMS) qualified a subset of the candidates based on highly specific, targeted detection in peripheral plasma, including some markers unlikely to have been identified without this step. Analyses of peripheral plasma from controls and patients with PMI or spontaneous MI by quantitative multiple reaction monitoring mass spectrometry or immunoassays suggest that the candidate biomarkers may be specific to MI. This study demonstrates that modern proteomic technologies, when coherently integrated, can yield novel cardiovascular biomarkers meriting further evaluation in large, heterogeneous cohorts.
Celotno besedilo
Dostopno za:
DOBA, IJS, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
Heart failure (HF) is a major public health problem characterized by inability of the heart to maintain sufficient output of blood. The systematic characterization of circulating proteins across ...different stages of HF may provide pathophysiological insights and identify therapeutic targets. Here we report application of aptamer-based proteomics to identify proteins associated with prospective HF incidence in a population-based cohort, implicating modulation of immunological, complement, coagulation, natriuretic and matrix remodeling pathways up to two decades prior to overt disease onset. We observe further divergence of these proteins from the general population in advanced HF, and regression after heart transplantation. By leveraging coronary sinus samples and transcriptomic tools, we describe likely cardiac and specific cellular origins for several of the proteins, including Nt-proBNP, thrombospondin-2, interleukin-18 receptor, gelsolin, and activated C5. Our findings provide a broad perspective on both cardiac and systemic factors associated with HF development.
Bufalin, the main active ingredient of the traditional Chinese medicine huachansu, is used in the clinical treatment of colorectal cancer and has multiple effects, including the inhibition of ...migratory invasion, reversal of multi-drug resistance, induction of apoptosis and differentiation, and inhibition of angiogenesis.
We collected relevant articles on bufalin from 2003 to 2022 using the Web Science platform, and analysed the information using VOSviewer, CiteSpace, and Microsoft Excel to categorise and summarise the publications over the past 20 years.
We collected 371 papers, with a steady increase in the number of articles published globally. China has the highest number of published articles, whereas Japan has the highest number of citations. Currently, there is considerable enthusiasm for investigating the anti-tumour mechanism of bufalin and optimising drug delivery systems for its administration.
For the first time, we present a comprehensive overview of papers published worldwide on bufalin over the past two decades and the progress of its application in tumour therapy. We summarised the key authors, institutions, and countries that have contributed to the field and the potential of bufalin for the treatment of cancer. This will help other researchers obtain an overview of progress in the field, enhance collaboration and knowledge sharing, and promote future research on bufalin.
Oxidative stress is considered to be a critical mediator in liver injury of various etiologies. Depletion of glutathione (GSH), the major antioxidant in liver, has been associated with numerous liver ...diseases. To explore the specific role of hepatic GSH in vivo, we targeted Gclc, a gene essential for GSH synthesis, so that it was flanked by loxP sites and used the albumin‐cyclization recombination (Alb‐Cre) transgene to disrupt the Gclc gene specifically in hepatocytes. Deletion within the Gclc gene neared completion by postnatal day (PND)14, and loss of GCLC protein was complete by PND21. Cellular GSH was progressively depleted between PND14 and PND28—although loss of mitochondrial GSH was less severe. Nevertheless, ultrastructural examination of liver revealed dramatic changes in mitochondrial morphology; these alterations were accompanied by striking decreases in mitochondrial function in vitro, cellular ATP, and a marked increase in lipid peroxidation. Plasma liver biochemistry tests from these mice were consistent with progressive severe parenchymal damage. Starting at PND21, livers from hepatocyte‐specific Gclc knockout Gclc(h/h) mice showed histological features of hepatic steatosis; this included inflammation and hepatocyte death, which progressed in severity such that mice died at approximately 1 month of age due to complications from liver failure. Conclusion: GSH is essential for hepatic function and loss of hepatocyte GSH synthesis leads to steatosis with mitochondrial injury and hepatic failure. (HEPATOLOGY 2007.)
RATIONALE:Integrin-linked kinase (ILK) is located at focal adhesions and links the extracellular matrix (ECM) to the actin cytoskeleton via β1- and β3-integrins. ILK plays a role in the activation of ...kinases including protein kinase B/Akt and glycogen synthase kinase 3β and regulates cell proliferation, motility, and survival.
OBJECTIVE:To determine the function of ILK in vascular smooth muscle cells (SMCs) in vivo.
METHODS AND RESULTS:SM22CreIlk conditional mutant mice were generated in which the Ilk gene was selectively ablated in SMCs. SM22CreIlk conditional mutant mice survive to birth but die in the perinatal period exhibiting multiple vascular pathologies including aneurysmal dilatation of the aorta and patent ductus arteriosus (PDA). Defects in morphogenetic development of the aorta were observed as early as E12.5 in SM22CreIlk mutant embryos. By late gestation (E16.5 to 18.5), striking expansion of the thoracic aorta was observed in ILK mutant embryos. Histological analyses revealed that the structural organization of the arterial tunica media is severely disrupted with profound derangements in SMC morphology, cell-cell, and cell-matrix relationships, including disruption of the elastic lamellae. ILK deletion in primary aortic SMCs results in alterations of RhoA/cytoskeletal signaling transduced through aberrant localization of myocardin-related transcription factor (MRTF)-A repressing the transcription and expression of SMC genes, which are required for the maintenance of the contractile SMC phenotype.
CONCLUSIONS:These data identify a molecular pathway linking ILK signaling to the contractile SMC gene program. Activation of this pathway is required for morphogenetic development of the aorta and ductus arteriosus during embryonic and postnatal survival.
Oxidative stress induced by 2,3,7,8-tetrachlorodibenzo- p -dioxin
(TCDD; dioxin) is poorly understood. Following one dose of TCDD (5 μg/kg
body weight), mitochondrial succinate-dependent production ...of superoxide and
H 2 O 2 in mouse liver doubled at 7â28 days, then
subsided by day 56; concomitantly, levels of GSH and GSSG increased in both
cytosol and mitochondria. Cytosol displayed a typical oxidative stress
response, consisting of diminished GSH relative to GSSG, decreased potential
to reduce protein-SSG mixed disulfide bonds (type 1 thiol redox switch) or
protein-SS-protein disulfide bonds (type 2 thiol redox switch), and a +10 mV
change in GSSG/2GSH reduction potential. In contrast, mitochondria showed a
rise in reduction state, consisting of increased GSH relative to GSSG,
increases in type 1 and type 2 thiol redox switches, and a â25 mV change
in GSSG/2GSH reduction potential. Comparing Ahr (â/â)
knock-out and wild-type mice, we found that TCDD-induced thiol changes in both
cytosol and mitochondria were dependent on the aromatic hydrocarbon receptor
(AHR). GSH was rapidly taken up by mitochondria and stimulated
succinate-dependent H 2 O 2 production. A linear dependence
of H 2 O 2 productionon thereduction potential for
GSSG/2GSH exists between â150 and â300 mV. The TCDD-stimulated
increase in succinate-dependent and thiol-stimulated production of reactive
oxygen paralleled a four-fold increase in formamidopyrimidine DNA
N -glycosylase (FPG)-sensitive cleavage sites in mitochondrial DNA,
compared with a two-fold increase in nuclear DNA. These results suggest that
TCDD produces an AHR-dependent oxidative stress in mitochondria, with
concomitant mitochondrial DNA damage mediated, at least in part, by an
increase in the mitochondrial thiol reduction state.
Mitochondria generate ATP and participate in signal transduction and
cellular pathology and/or cell death. TCDD
(2,3,7,8-tetrachlorodibenzo-
p
-dioxin) decreases hepatic ATP
levels and generates ...mitochondrial oxidative DNA damage, which is exacerbated by
increasing mitochondrial glutathione redox state and by inner-membrane
hyperpolarization. This study identifies mitochondrial targets of TCDD that
initiate and sustain reactive oxygen production and decreased ATP levels. One
week after treating mice with TCDD, liver ubiquinone (Q) levels were
significantly decreased, while rates of succinoxidase and Q-cytochrome
c
oxidoreductase activities were increased. However, the
expected increase in Q reduction state following TCDD treatment did not occur;
instead, Q was more oxidized. These results could be explained by an ATP
synthase defect, a premise supported by the unusual finding that TCDD lowers
ATP/O ratios without concomitant changes in respiratory control ratios. Such
results suggest either a futile cycle in ATP synthesis, or hydrolysis of
newly-synthesized ATP prior to release. The TCDD-mediated decrease in Q,
concomitant with an increase in respiration, increases complex 3 redox-cycling.
This acts in concert with glutathione to increase membrane potential and
reactive oxygen production. The proposed defect in ATP synthase explains both
the greater respiratory rates and the lower tissue ATP levels.
Leukotriene B(4) is a proinflammatory lipid mediator generated by the enzymes 5-lipoxygenase and leukotriene A(4) hydrolase. Leukotriene B(4) signals primarily through its high-affinity G ...protein-coupled receptor, BLT1, which is highly expressed on specific leukocyte subsets. Recent genetic studies in humans as well as knockout studies in mice have implicated the leukotriene synthesis pathway in several vascular pathologies. In this study, we tested the hypothesis that BLT1 is necessary for abdominal aortic aneurysm (AAA) formation, a major complication of atherosclerotic vascular disease. Chow-fed Apoe(-/-) and Apoe(-/-)/Blt1(-/-) mice were treated with a 4-wk infusion of angiotensin II (1000 ng/min/kg) beginning at 20 wk of age, in a well-established murine AAA model. We found a reduced incidence of AAA formation as well as concordant reductions in the maximum suprarenal/infrarenal diameter and total suprarenal/infrarenal area in the angiotensin II-treated Apoe(-/-)/Blt1(-/-) mice as compared with the Apoe(-/-) controls. Diminished AAA formation in BLT1-deficient mice was associated with significant reductions in mononuclear cell chemoattractants and leukocyte accumulation in the vessel wall, as well as striking reductions in the production of matrix metalloproteinases-2 and -9. Thus, we have shown that BLT1 contributes to the frequency and size of abdominal aortic aneurysms in mice and that BLT1 deletion in turn inhibits proinflammatory circuits and enzymes that modulate vessel wall integrity. These findings extend the role of BLT1 to a critical complication of vascular disease and underscore its potential as a target for intervention in modulating multiple pathologies related to atherosclerosis.
Background & Aims Certain liver diseases have been associated with depletion of glutathione (GSH), the major antioxidant in the liver. A recent report about Gclch/h mice with a hepatocyte-specific ...ablation of Gclc (the gene encoding the catalytic subunit of the rate-limiting enzyme in GSH synthesis) has shown an essential role of GSH in hepatic function. Gclch/h mice develop severe steatosis and die of liver failure within one month, due to ∼95% depletion of hepatic GSH; mitochondria are the major affected organelles, displaying abnormal ultrastructure and impaired functioning. Methods Gclch/h mice were fed with L - N -acetylcysteine (NAC; 10 g/L) in drinking water, starting at postnatal day 18. Results Gclch/h mice were rescued by use of NAC supplementation, and survived until adulthood. NAC replenished the mitochondrial GSH pool and attenuated mitochondrial damage, with accompanying diminished hepatic steatosis; however, abnormal liver biochemical tests, hepatocyte death, and hepatic oxidative stress persisted in the rescued mice. At 50 days of age, the liver from rescued Gclch/h mice started to display characteristics of fibrosis and at age 120 days, macronodular cirrhosis was observed. Immunohistostaining for liver-specific markers as well as the expression profile of hepatic cytokines indicated that the repopulation of hepatocytes in the cirrhotic nodules involved the expansion of oval cells. Conclusions Replenishment of mitochondrial GSH and restoration of mitochondrial function by NAC prevents mortality caused by the loss of hepatocyte GSH de novo synthesis, allowing steatosis to progress to a chronic stage. Thus, with NAC supplementation, Gclch/h mice provide a model for the development of liver fibrosis and cirrhosis.
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