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Marschall S Runge

Publications and source records attributed to Marschall S Runge.

At least 19 recordsLinked to original sources
PubMed2006

The SecA2 secretion factor of Mycobacterium tuberculosis promotes growth in macrophages and inhibits the host immune response.

The SecA protein is present in all bacteria, and it is a central component of the general Sec-dependent protein export pathway. An unusual property of Mycobacterium tuberculosis is the presence of two SecA proteins: SecA1, the essential "housekeeping" SecA, and SecA2, the accessory secretion factor. Here, we report that a DeltasecA2 mutant of M. tuberculosis was defective for growth in the early stages of low-dose aerosol infection of C57BL/6 mice, a time during which the bacillus is primarily replicating in macrophages. Consistent with this in vivo phenotype, we found that the DeltasecA2 mutant was defective for growth in macrophages from C57BL/6 mice. The DeltasecA2 mutant was also attenuated for growth in macrophages from phox(-/-) mice and from NOS2(-/-) mice. These mice are defective in the reactive oxygen intermediate (ROI)-generating phagocyte oxidase and the reactive nitrogen intermediate (RNI)-generating inducible nitric oxide synthase, respectively. This indicated a role for SecA2 in the intracellular growth of M. tuberculosis that is independent of protecting against these ROIs or RNIs. Macrophages infected with the DeltasecA2 mutant produced higher levels of tumor necrosis factor alpha, interleukin-6, RNI, and gamma interferon-induced major histocompatibility complex class II. This demonstrated a function for M. tuberculosis SecA2 in suppressing macrophage immune responses, which could explain the role of SecA2 in intracellular growth. Our results provide another example of a relationship between M. tuberculosis virulence and inhibition of the host immune response.

Adenosine Triphosphatases↗
PubMed2006

MnSOD deficiency increases endothelial dysfunction in ApoE-deficient mice.

OBJECTIVE: In mice that are heterozygous for mitochondrial superoxide dismutase (SOD2(+/-)) with apoE deficiency (apoE(-/-)), mitochondrial DNA damage increases formation of atherosclerotic lesions. The purpose of this study was to determine whether SOD2 provides protection against increased vascular superoxide and endothelial dysfunction in apoE-deficient mice. METHODS AND RESULTS: Four groups of mice [apoE(-/-)/SOD2(+/-) (apoe/sod2), apoE(-/-)/SOD2(+/+) (apoe/SOD2), apoE(+/+)/SOD2(+/-) (apoE/sod2), and apoE(+/+)/SOD2(+/+) (apoE/SOD2)] were fed normal chow diet, and studied at 15 to 17 months of age. Serum cholesterol levels were similar in apoe/sod2 and apoe/SOD2 mice, and also were similar in apoE/sod2 and apoE/SOD2 mice. Intimal area was increased in aorta, but not carotid artery, of apoe/sod2 and apoe/SOD2 mice. In carotid artery, superoxide was increased (67+/-5.2 relative fluorescence intensity/vessel area [RI] in apoe/sod2 mice, 31+/-3.1 RI in apoE/SOD2 mice, P<0.05), and relaxation to acetylcholine was impaired in apoe/sod2 mice versus apoe/ SOD2, apoE/sod2, apoE/SOD2 mice. Tiron improved relaxation to acetylcholine. In aorta, superoxide levels were increased and relaxation to acetylcholine was impaired in apoe/sod2 and apoe/SOD2 mice, but responses were similar in apoe/sod2 and apoe/SOD2 mice. CONCLUSIONS: SOD2 protects against oxidative stress and endothelial dysfunction in carotid artery of apoE-deficient mice.

Animals↗
PubMed2006

Thrombin and NAD(P)H oxidase-mediated regulation of CD44 and BMP4-Id pathway in VSMC, restenosis, and atherosclerosis.

To characterize novel signaling pathways that underlie NAD(P)H oxidase-mediated signaling in atherosclerosis, we first examined differences in thrombin-induced gene expression between wild-type and p47phox(-/-) (NAD[P]H oxidase-deficient) VSMC. Of the 9000 genes analyzed by cDNA microarray method at the G1/S transition point, 76 genes were similarly and significantly modulated in both the cell types, whereas another 22 genes that encompass various functional groups were regulated in NAD(P)H oxidase-dependent manner. Among these 22 genes, thrombin-induced NAD(P)H oxidase-mediated regulation of Klf15, Igbp1, Ak4, Adamts5, Ech1, Serp1, Sec61a2, Aox1, Aoh1, Fxyd5, Rai14, and Serpinh1 was shown for the first time in VSMC. The role of NAD(P)H oxidase in the regulation of a subset of these genes (CD44, BMP4, Id1, and Id3) was confirmed using modulators of reactive oxygen species (ROS) generation, a ROS scavenger and in gain-of-function experiments. We then characterized regulation of these genes in restenosis and atherosclerosis. In both apoE(-/-) mice and in a mouse vascular injury model, these genes are regulated in NAD(P)H oxidase-dependent manner during vascular lesion formation. Based on these findings, we propose that NAD(P)H oxidase-dependent gene expression in general, and the CD44 and BMP4-Id signaling pathway in particular, is important in restenosis and atherosclerosis.

Animals↗
PubMed2005

Differential activation of mitogenic signaling pathways in aortic smooth muscle cells deficient in superoxide dismutase isoforms.

OBJECTIVE: Reactive oxygen species (ROS) integrate cellular signaling pathways involved in aortic smooth muscle cell (SMC) proliferation and migration associated with atherosclerosis. However, the effect of subcellular localization of ROS on SMC mitogenic signaling is not yet fully understood. METHODS AND RESULTS: We used superoxide dismutase (SOD)-deficient mouse aortic SMCs to address the role of subcellular ROS localization on SMC phenotype and mitogenic signaling. Compared with wild-type, a 54% decrease in total SOD activity (almost equal to 50% decrease in SOD1 protein levels) and a 42% reduction in SOD2 activity (approximately equal to 50% decrease in SOD2 protein levels) were observed in SOD1+/- and SOD2+/- SMCs, respectively. Consistent with this, basal and thrombin-induced superoxide levels increased in these SMCs. SOD1+/- and SOD2+/- SMCs exhibit increased basal proliferation and enhanced [3H]-thymidine and [3H]-leucine incorporation in basal and thrombin-stimulated conditions. Our results indicate preferential activation of extracellular signal-regulated kinase 1/2 (ERK1/2) and p38 mitogen-activated protein kinases in SOD1+/- and janus kinase/signal transducer and activator of transcriptase (JAK/STAT) pathway in SOD2+/- SMCs. Pharmacological inhibitors of ERK1/2 p38 and JAK2 confirm the SOD genotype-dependent SMC proliferation. CONCLUSIONS: Our results suggest that SOD1 and SOD2 regulate SMC quiescence by suppressing divergent mitogenic signaling pathways, and dysregulation of these enzymes under pathophysiological conditions may lead to SMC hyperplasia and hypertrophy.

Animals↗
PubMed2005

Identification of a novel functional androgen response element within hPar1 promoter: implications to prostate cancer progression.

Human protease-activated receptor-1 (hPar1) plays a role in malignant and physiological invasion processes. We have identified a functional androgen response element (ARE) located in the hPar1 promoter upstream of the transcription start site at -1791 to -1777. Dihydrotestosterone treatment of the prostate cancer cell line LNCaP increased endogenous hPar1 mRNA levels, consistent with the threefold increase in promoter activity of hPar1-luciferase reporter construct. Specific binding of the hPar1-derived ARE to LNCaP nuclear extracts was demonstrated by electrophoretic mobility shift assay. This binding was abrogated by antiandrogen receptor (anti-AR) antibodies or excess cold oligonucleotide but not by a mutated oligonucleotide. Moreover, using chromatin immunoprecipitation assays, we confirm the in vivo interaction between the AR and ARE domain of the hPar1 promoter. In parallel, we show that hormone ablation therapy markedly reduces the otherwise high hPar1 expression levels in prostate cancer biopsy specimens. We suggest that the hPar1 gene is regulated transcriptionally by androgens, representing one of several target genes effectively reduced during hormone ablation therapy. A major limitation of hormonal deprivation is that it causes only a temporary remission, and the cancer eventually reappears in a more malignant, androgen-independent form. hPar1 is also overexpressed in CL1 cells, an aggressively metastasizing, hormone-independent subclone of LNCaP, and in PC3 prostate adenocarcinoma lacking AR in a mechanism yet to be fully elucidated. These data may imply that hPar1 expression correlates with prostate cancer progression in androgen-dependent and -independent phases and therefore, provides an instrumental, therapeutic target for treatment in prostate cancer.

Adenocarcinoma↗
PubMed2005

Diagnosis and treatment of non-hemodynamically significant coronary heart disease: where to start?

In the U.S. and all industrialized countries, more deaths result from heart attack and stroke than from any other cause. Increasingly it is proposed that many cardiac events occur following the rupture of minor, non-hemodynamically significant atherosclerotic plaque. Indeed many policy makers and some physicians have questioned the importance of traditional screening and treatment strategies for hemodynamically significant coronary artery lesions. As an alternative, it has been suggested that screening and treatment approaches should be guided by emerging data that support the predictive value of measures of inflammation, such as high sensitivity C-reactive protein, or of genetic markers. Our goal is review the biology of acute coronary events and the results of population-based studies and, in this light, consider the usefulness of the current "state-of-the-art" methods for diagnosing coronary heart disease.

Coronary Disease↗
PubMed2004

Differential effects of exercise on aortic mitochondria.

Routine exercise is widely recognized as cardioprotective. Exercise induces a variety of effects within the cardiovasculature, including decreased mitochondrial damage and improved aerobic capacity. It has been generally thought that the transient increase in oxidative stress associated with exercise initiates cardioprotective processes. Somewhat paradoxically, increased oxidative stress associated with cardiovascular disease (CVD) risk factors is thought to play an important role in the promotion and development of CVD. Hence, it is possible that CVD risk factors that increase oxidative stress (e.g., hypercholesterolemia) may modulate the cardioprotective effects of exercise. In this regard, the interaction between CVD risk factors and exercise on atherosclerotic lesion development and basal oxidant load is less defined. To determine the influence of preexistent hypercholesterolemia on cardioprotective effects of exercise, atherosclerotic lesion formation, oxidant load, mitochondrial damage, protein nitration (3-nitrotyrosine levels), and mitochondrial enzyme activities were determined in aortic tissues from normocholesterolemic (C57 control) and hypercholesterolemic [apoliprotein E-deficient (apoE(-/-))] mice after 16 wk of regular exercise. In normocholesterolemic mice, regular exercise was associated with decreased mitochondrial damage and oxidant load and increased SOD2 and adenine nucleotide translocator activities. Exercise did not decrease endogenous oxidant load and mitochondrial damage in hypercholesterolemic mice and did not reduce atherosclerotic lesion development. These data are consistent with the notion that CVD risk factors associated with increased oxidative stress can alter the benefits of exercise and that mitochondrial damage appears to be correlated with the cardiovascular effects of exercise.

Animals↗
PubMed2004

Oxidative stress and vascular disease.

Growing evidence indicates that chronic and acute overproduction of reactive oxygen species (ROS) under pathophysiologic conditions is integral in the development of cardiovascular diseases (CVD). These ROS can be released from nicotinamide adenine dinucleotide (phosphate) oxidase, xanthine oxidase, lipoxygenase, mitochondria, or the uncoupling of nitric oxide synthase in vascular cells. ROS mediate various signaling pathways that underlie vascular inflammation in atherogenesis: from the initiation of fatty streak development through lesion progress to ultimate plaque rupture. Various animal models of oxidative stress support the notion that ROS have a causal role in atherosclerosis and other cardiovascular diseases. Human investigations also support the oxidative stress hypothesis of atherosclerosis. Oxidative stress is the unifying mechanism for many CVD risk factors, which additionally supports its central role in CVD. Despite the demonstrated role of antioxidants in cellular and animal studies, the ineffectiveness of antioxidants in reducing cardiovascular death and morbidity in clinical trials has led many investigators to question the importance of oxidative stress in human atherosclerosis. Others have argued that the prime factor for the mixed outcomes from using antioxidants to prevent CVD may be the lack of specific and sensitive biomarkers by which to assess the oxidative stress phenotypes underlying CVD. A better understanding of the complexity of cellular redox reactions, development of a new class of antioxidants targeted to specific subcellular locales, and the phenotype-genotype linkage analysis for oxidative stress will likely be avenues for future research in this area as we move toward the broader use of pharmacological and regenerative therapies in the treatment and prevention of CVD.

Animals↗
PubMed2004

Limiting brain and lung damage after coronary artery bypass grafting: an alternative to conventional coronary artery bypass graft.

The development of coronary artery bypass graft (CABG) for the treatment of coronary heart disease has resulted in reduced morbidity and mortality compared with medical therapy. Even with the rapid development of improved percutaneous interventions, CABG remains an important approach for treating patients with advanced coronary heart disease. However, recent studies and commentary reporting an alarmingly high incidence of subtle, cognitive decline following CABG have generated questions about whether these adverse outcomes could be lessened. Even after considerable study, there is no consensus as to the cause of brain and lung injury after CABG and cardiopulmonary bypass, nor an agreed upon, mechanistic approach to study its prevention. The potential causes of these adverse outcomes and a simple approach are described, involving the use of the cannulae, biventricular pulsatile flow pump, and a blood substitute to optimize the perfusion of brain and alveolar cells, minimize systemic microembolization, and limit post-CABG cognitive decline.

Blood Substitutes↗
PubMed2004

Age-related changes in matrix metalloproteinase-9 regulation in cultured mouse aortic smooth muscle cells.

We previously reported that aortic smooth muscle cells (SMC) from aged mice have an age-related decline in proliferative capacity compared with those derived from young mice. Here we investigated matrix metalloproteinase-9 (MMP-9) regulation in both young and aged SMC. Zymography, immunoblot, and northern blot analysis showed that MMP-9 expression is significantly reduced in response to tumor necrosis factor-alpha stimulation with increasing in vitro age. Mutational analysis, gel shift assays and supershift assays demonstrated that the lower MMP-9 expression in aged SMC is associated with lower activities of NF-kappaB and AP-1. Since mitogen-activated protein kinase ERK1/2 induce MMP-9 expression, we examined whether U0126, an ERK1/2 inhibitor, influenced MMP-9 expression in aged SMC. Treatment with U0126 successfully inhibited MMP-9 expression in both young and aged SMC. Finally, to analyze the causal relationship between replicative senescence and MMP-9 expression, we stably overexpressed the MMP-9 gene in aged SMC and we showed no alteration of the proliferative capacity of the transduced cells. Taken together, these results suggest that down-regulation of MMP-9 expression in SMC may play a role in vascular remodeling during in vitro aging.

Aging↗
PubMed2004

Fibrin-targeted direct factor Xa inhibition: construction and characterization of a recombinant factor Xa inhibitor composed of an anti-fibrin single-chain antibody and tick anticoagulant peptide.

We investigated whether the direct fXa inhibitor tick anticoagulant peptide (TAP) can be N-terminally coupled to a clot-targeting, single-chain antibody specific for fibrin (scFv(59D8)). Due to its unique position at the convergence point of the intrinsic and extrinsic pathways early in the coagulation cascade, factor Xa (fXa) represents an attractive therapeutic target. In contrast to indirect inhibitors, direct fXa inhibitors effectively inhibit clot-bound and prothrombinase-associated fXa. Targeting of direct fXa inhibitors to clots promises to enhance local anticoagulative potency and to reduce systemic anticoagulation which potentially results in less bleeding complications.TAP is a highly potent fXa inhibitor. Since its N-terminus is essential for anti-fXa activity, it was a challenging question, whether TAP will be active as a N-terminally coupled fusion molecule. Two step affinity chromatography with Ni(2+) and beta(15-22)-peptide of human fibrin results in a pure 36 kDa protein, which was tested for its targeting function and anti-fXa activity. The recombinant fusion did not destroy the function of the fusion partners. Antibody binding function was on a par with the parent molecule. TAP activity was partially reduced, arguing that a free N-terminus is not required for anti-fXa activity, but is important for maximal potency. In human whole blood clots, scFv(59D8)-TAP revealed anticoagulative properties at concentrations (200 to 500 nM) where non-targeted TAP did not reveal anticoagulative activity at all. In summary, scFv(59D8)-TAP constitutes a promising new anticoagulant with fibrin-targeted factor Xa inhibition. The production in E. coli and the established purification methods are a solid basis for a modern, large scale production at low cost and reproducible activity.

Amino Acid Sequence↗
PubMed2003

Construction and in vitro testing of a novel fab-hirudin-based fusion protein that targets fibrin and inhibits thrombin in a factor xa-dependent manner.

Fibrin targeting of the thrombin inhibitor hirudin via chemical coupling is effective in vitro and in vivo. However, since chemical coupling has limitations, a recombinant approach was taken to improve the fibrin-targeting ability of hirudin. Additionally, to activate hirudin selectively at the target area and thereby limit side effects in an in vivo setting, the authors aimed to construct an inactive precursor molecule that is converted into an active thrombin inhibitor only upon cleavage by factor Xa. Using PCR, the coding region for hirudin was fused to parts of the genomic DNA of the IgG heavy chain that was cloned from the antifibrin antibody-producing hybridoma cell line 59D8. Additionally, a factor Xa recognition site was introduced between the antibody and the hirudin sequence. The fusion construct was then transfected into a heavy-chain loss variant of the hybridoma cell line 59D8. After selection of stable hybridoma clones, the expressed fusion protein was evaluated for its molecular size (57 kd) and its binding ability to the fibrin-specific peptide Bbeta 15-22. The cleavage of the fusion protein by factor Xa was demonstrated by HPLC. The recombinant anticoagulant revealed antithrombin activity only after cleavage by factor Xa. Thus, the newly designed hirudin fusion protein revealed the anticipated functions in vitro. Further experiments are needed to prove whether this precursor anticoagulant allows a highly clot-specific and efficient thrombin inhibition in vivo.

Antibodies, Monoclonal↗
PubMed2002

Mitochondrial integrity and function in atherogenesis.

BACKGROUND: Coronary atherosclerotic disease remains the leading cause of death in the Western world. Although the exact sequence of events in this process is controversial, reactive oxygen and nitrogen species (RS) likely play an important role in vascular cell dysfunction and atherogenesis. Oxidative damage to the mitochondrial genome with resultant mitochondrial dysfunction is an important consequence of increased intracellular RS. METHODS AND RESULTS: We examined the contribution of mitochondrial oxidant generation and DNA damage to the progression of atherosclerotic lesions in human arterial specimens and atherosclerosis-prone mice. Mitochondrial DNA damage not only correlated with the extent of atherosclerosis in human specimens and aortas from apolipoprotein E(-/-) mice but also preceded atherogenesis in young apolipoprotein E(-/-) mice. Apolipoprotein E(-/-) mice deficient in manganese superoxide dismutase, a mitochondrial antioxidant enzyme, exhibited early increases in mitochondrial DNA damage and a phenotype of accelerated atherogenesis at arterial branch points. CONCLUSIONS: Mitochondrial DNA damage may result from RS production in vascular tissues and may in turn be an early event in the initiation of atherosclerotic lesions.

Animals↗