Protective Function of Ahnak1 in Vascular Healing after Wire Injury.

AIM: Vascular remodeling following injury substantially accounts for restenosis and adverse clinical outcomes. In this study, we investigated the role of the giant scaffold protein Ahnak1 in vascular healing after endothelial denudation of the murine femoral artery. METHODS: The spatiotemporal expression pattern of Ahnak1 and Ahnak2 was examined using specific antibodies and real-time quantitative PCR. Following wire-mediated endothelial injury of Ahnak1-deficient mice and wild-type (WT) littermates, the processes of vascular healing were analyzed. RESULTS: Ahnak1 and Ahnak2 showed a mutually exclusive vascular expression pattern, with Ahnak1 being expressed in the endothelium and Ahnak2 in the medial cells in naïve WT arteries. After injury, a marked increase of Ahnak1- and Ahnak2-positive cells at the lesion site became evident. Both proteins showed a strong upregulation in neointimal cells 14 days after injury. Ahnak1-deficient mice showed delayed vascular healing and dramatically impaired re-endothelialization that resulted in prolonged adverse vascular remodeling, when compared to the WT littermates. CONCLUSION: The large scaffold and adaptor proteins Ahnak1 and Ahnak2 exhibit differential expression patterns and functions in naïve and injured arteries. Ahnak1 plays a nonredundant protective role in vascular healing.

Novel role of the CXC chemokine receptor 3 in inflammatory response to arterial injury: involvement of mTORC1.

Atherosclerosis, restenosis, and posttransplant graft atherosclerosis are characterized by endothelial damage, infiltration of inflammatory cells, and proliferation of smooth muscle cells. The CXCR3-activating chemokines interferon-gamma inducible protein 10 (IP10) and MIG (monokine induced by interferon-gamma) have been implicated in vascular repair and remodeling. The underlying molecular mechanisms, however, remain elusive. Here, we show that wire-mediated arterial injury induced local and systemic expression of IP10 and MIG, resulting in enhanced recruitment of CXCR3(+) leukocytes and hematopoietic progenitor cells. This was accompanied by profound activation of mammalian target of rapamycin complex (mTORC)1, increased reactive oxygen species production, apoptosis, and intimal hyperplasia. Genetic and pharmacological inactivation of CXCR3 signaling not only suppressed recruitment of inflammatory cells but also abolished mTORC1 activation, reduced reactive oxygen species generation, and blocked apoptosis of vascular cells, resulting in significant reduction of intimal hyperplasia in vivo. In vitro, stimulation of T cells with IP10 directly activated mTORC1 and induced generation of reactive oxygen species and apoptosis in an mTORC1-dependent manner. These results strongly indicate that CXCR3-dependent activation of mTORC1 directly links stimulation of the Th1 immune system with the proliferative response of intimal cells in vascular remodeling.

A crucial role of glycoprotein VI for platelet recruitment to the injured arterial wall in vivo.

Platelet adhesion and aggregation at sites of vascular injury is crucial for hemostasis but may lead to arterial occlusion in the setting of atherosclerosis and precipitate diseases such as myocardial infarction. A current hypothesis suggests that platelet glycoprotein (GP) Ib interaction with von Willebrand factor recruits flowing platelets to the injured vessel wall, where subendothelial fibrillar collagens support their firm adhesion and activation. However, so far this hypothesis has not been tested in vivo. Here, we demonstrate by intravital fluorescence microscopy of the mouse carotid artery that inhibition or absence of the major platelet collagen receptor, GPVI, abolishes platelet-vessel wall interactions after endothelial denudation. Unexpectedly, inhibition of GPVI by the monoclonal antibody JAQ1 reduced platelet tethering to the subendothelium by approximately 89%. In addition, stable arrest and aggregation of platelets was virtually abolished under these conditions. Using different models of arterial injury, the strict requirement for GPVI in these processes was confirmed in GPVI-deficient mice, where platelets also failed to adhere and aggregate on the damaged vessel wall. These findings reveal an unexpected role of GPVI in the initiation of platelet attachment at sites of vascular injury and unequivocally identify platelet-collagen interactions (via GPVI) as the major determinant of arterial thrombus formation.

Role of bone marrow-derived cells in the genetic control of restenosis.

OBJECTIVE: Angiographic indexes of restenosis after coronary stent placement in patients show a bimodal pattern suggesting the existence of two populations with different risk of restenosis. This is reflected in the arterial remodeling response of inbred mouse strains arguing for a genetic control of the mechanisms leading to lumen narrowing. As bone marrow-derived cells (BMCs) contribute to vascular healing after arterial injury, we investigated the role of BMCs in the genetic control of restenosis. METHODS AND RESULTS: 129X1/SvJ mice developed significantly more neointima and late lumen loss compared to C57BL/6 mice. Gene expression analysis of intimal tissue revealed major differences in the expression of inflammatory and hematopoietic stem and progenitor cell-associated genes in response to arterial injury. In 129X1/SvJ mice stronger mobilization of lin(-)sca-1(+)CXCR4(+) cells was observed after vascular injury. Bone marrow transplantation identified the extent of neointima formation as clearly dependent on the genetic background of BMCs (ie, mice with 129X1/SvJ BMCs developed more intimal hyperplasia). The inflammatory response and the recruitment of BMCs to the site of arterial injury were significantly increased in mice with 129X1/SvJ BMCs. CONCLUSIONS: The genetically controlled mechanisms leading to lumen narrowing in vascular remodeling are dependent on mobilization and recruitment capacities of particular BMCs.

In vivo biocompatibility study of degradable homo- versus multiblock copolymers and their (micro)structure compared to an established biomaterial.

Copolyetheresterurethane (PDC) is a biodegradable, shape-memory biomaterial, which has been shown to be of low toxicity and pro-angiogenic in vitro. In the present study we examined the in vivo compatibility of PDC as a compression molded film and as electrospun scaffolds and its well established constituent, the homopolymer poly(p-dioxanone) (PPDO), which were compared with the clinically used poly[(vinylidene fluoride)-co-hexafluoropropene] (PVDF) as reference material. The materials were implanted in the subcutaneous tissue of mice and the host responses were analyzed histologically 7 and 28 days after implantation.All materials induced a foreign body response (FRB) including the induction of foreign body giant cells and a peripheral fibrous capsule. PDC, PPDO and PVDF films showed no signs of degradation after 28 days. PDC films showed a significantly reduced associated macrophage layer and fibrous capsule on their surface. Few fragments of PDC and PPDO scaffolds were present at the implantation site, while PVDF scaffolds were still present in large amounts at day 28. Especially aligned electrospun PDC scaffold induced a significantly thinner fibrous and a slightly reduced inflammatory response after 28 days of implantation. In addition, only PDC aligned fibrous scaffold structures induced a significant increase in angiogenesis.In summary, PDC films outperformed PPDO and PVDF films in terms of compatibility, especially in capsule and macrophage layer thickness. Through microstructuring of PDC and PPDO into scaffolds an almost complete degradation was observed after 28 days, while their respective films remained almost unchanged. However, the capsule thickness of all scaffolds was comparable to the films after 28 days. Finally, the parallel arrangement of PDC fibers enabled a strong enhancement of angiogenesis within the scaffold. Hence, material chemistries influence overall compatibility in vivo, while angiogenesis could be influenced more strongly by microstructural parameters than chemical ones.

EMAP-II downregulation contributes to the beneficial effects of rapamycin after vascular injury.

AIMS: Neointima formation after vascular injury is strongly associated with inflammation. Rapamycin inhibits human neointima formation and reduces expression of the proinflammatory cytokine endothelial-monocyte activating peptide II (EMAP-II) in vitro. Here we investigated the interplay between EMAP-II and rapamycin after vascular injury in vivo. METHODS AND RESULTS: In a mouse model of vascular injury, mice were either not treated, given everolimus, a rapamycin derivate, or subjected to simultaneous challenge with everolimus and EMAP-II. EMAP-II expression was measured in coronary artery smooth muscle cells (CASMC) and monocytic cells in vitro and in patients after percutaneous coronary intervention (PCI). After vascular injury, rapamycin reduced neointima formation and adventitial thickening. Immunohistochemistry revealed reduced EMAP-II protein expression and suppressed recruitment of inflammatory cells. Simultaneous challenge with EMAP-II counteracted these effects of rapamycin. Expression of EMAP-II and its inhibition by rapamycin was confirmed in CASMC and monocytic cells. In patients, EMAP-II upregulation was confined to PCI of distal coronary artery segments and profoundly suppressed by oral rapamycin treatment. CONCLUSION: These data suggest important yet unrecognized roles of EMAP-II and adventitial inflammation in neointima formation: Through inhibition of EMAP-II, rapamycin reduces the recruitment of inflammatory cells to the adventitia and supports an early and bland healing.

Vascular remodeling in mice lacking the cytoplasmic domain of tissue factor.

Tissue factor (TF), the cell surface receptor for the serine protease FVIIa supports cell migration by interaction with the cytoskeleton. Intracellular signaling pathways dependent on the cytoplasmic domain of TF modify cell migration and may alter vascular remodeling. Vascular remodeling was analyzed in a femoral artery injury and a blood flow cessation model in mice with a targeted deletion of the 18 carboxy-terminal intracellular amino acids of TF (TF(Deltact/Deltact)) and compared with TF wild-type mice (TF(wt/wt)). Morphometric analysis revealed a decrease in the intima/media ratio after vascular injury in arteries from TF(Deltact/Deltact) compared with TF(wt/wt) mice (femoral artery injury: 2.4+/-0.3 TF(wt/wt) versus 0.6+/-0.3 TF(Deltact/Deltact), n=9 to 10, P=0.002; carotis ligation: 0.45+0.11 TF(wt/wt) versus 0.22+0.03 TF(Deltact/Deltact), n=12 to 14, P=0.09). This was caused by an increase in the media by 54% (P=0.04) in the femoral artery model and by 32% (P=0.03) after carotis ligation and was associated with an increased number of proliferating cells. Isolated aortic smooth muscle cells (SMCs) of TF(wt/wt) mice showed an increased migratory response toward the TF ligand active site-inhibited FVIIa that was abolished in TF(Deltact/Deltact) SMC. In contrast, the unstimulated proliferation rate was increased in TF(Deltact/Deltact) SMC compared with TF(wt/wt) SMCs. Thus, retention of SMCs attributable to a migratory defect and increased proliferation results in thickening of the media and in decrease in neointima formation after arterial injury. TF cytoplasmic domain signaling alters vascular remodeling and, thereby, may play a role in the development of restenosis, atherosclerotic disease, and neovascularization.

In vivo biocompatibility assessment of poly (ether imide) electrospun scaffolds.

Poly(ether imide) (PEI), which can be chemically functionalized with biologically active ligands, has emerged as a potential biomaterial for medical implants. Electrospun PEI scaffolds have shown advantageous properties, such as enhanced endothelial cell adherence, proliferation and low platelet adhesion in in vitro experiments. In this study, the in vivo behaviour of electrospun PEI scaffolds and PEI films was examined in a murine subcutaneous implantation model. Electrospun PEI scaffolds and films were surgically implanted subcutaneously in the dorsae of mice. The surrounding subcutaneous tissue response was examined via histopathological examination at 7 and 28 days after implantation. No serious adverse events were observed for both types of PEI implants. The presence of macrophages or foreign body giant cells in the vicinity of the implants and the formation of a fibrous capsule indicated a normal foreign body reaction towards PEI films and scaffolds. Capsule thickness and inflammatory infiltration cells significantly decreased for PEI scaffolds during days 7-28 while remaining unchanged for PEI films. The infiltration of cells into the implant was observed for PEI scaffolds 7 days after implantation and remained stable until 28 days of implantation. Additionally some, but not all, PEI scaffold implants induced the formation of functional blood vessels in the vicinity of the implants. Conclusively, this study demonstrates the in vivo biocompatibility of PEI implants, with favourable properties of electrospun PEI scaffolds regarding tissue integration and wound healing. Copyright © 2015 John Wiley & Sons, Ltd.

Randomized evaluation of the effects of filter-based distal protection on myocardial perfusion and infarct size after primary percutaneous catheter intervention in myocardial infarction with and without ST-segment elevation.

BACKGROUND: In acute myocardial infarction, distal embolization of debris during primary percutaneous catheter intervention may curtail microvascular reperfusion of the infarct region. Our randomized trial investigated whether distal protection with a filter device can improve microvascular perfusion and reduce infarct size after primary percutaneous catheter intervention. METHODS AND RESULTS: We enrolled 200 patients who had angina within 48 hours after onset of pain plus at least 1 of 3 additional criteria: ST-segment elevation, elevated myocardial marker proteins, and angiographic evidence of thrombotic occlusion. Among the patients included (83% men; mean age, 62+/-12 years), 100 were randomly assigned to the filter-wire group and 100 to the control group. The primary end point was the maximal adenosine-induced Doppler flow velocity in the recanalized infarct artery; the secondary end point was infarct size estimated by the volume of delayed enhancement on nuclear MRI. ST-segment elevation myocardial infarction was present in 68.5% of the patients; the median time from onset of pain was 6.9 hours. In the filter-wire group, maximal adenosine-induced flow velocity was 34+/-17 compared with 36+/-20 cm/s in the control group (P=0.46). Infarct sizes, assessed in 82 patients in the filter-wire group and 78 patients in the control group, were 11.8+/-9.3% of the left ventricular mass in the filter-wire group and 10.4+/-9.4% in the control group (P=0.33). Thirty-day mortality was 2% in filter-wire group and 3% in the control group. CONCLUSIONS: The filter wire as an adjunct to primary percutaneous catheter intervention in myocardial infarction with and without ST-segment elevation did not improve reperfusion or reduce infarct size.

Rapamycin attenuates vascular wall inflammation and progenitor cell promoters after angioplasty.

Rapamycin combines antiproliferative and antiinflammatory properties and reduces neointima formation after angioplasty in patients. Its effect on transcriptional programs governing neointima formation has not yet been investigated. Here, we systematically analyzed the effect of rapamycin on gene expression during neointima formation in a human organ culture model. After angioplasty, renal artery segments were cultured for 21 or 56 days in absence or presence of 100 ng/ml rapamycin. Gene expression analysis of 2312 genes revealed 264 regulated genes with a peak alteration after 21 days. Many of those were associated with recruitment of blood cells and inflammatory reactions of the vessel wall. Likewise, chemokines and cytokines such as M-CSF, IL-1beta, IL-8, beta-thromboglobulin, and EMAP-II were found up-regulated in response to vessel injury. Markers indicative for a facilitated recruitment and stimulation of hematopoetic progenitor cells (HPC), including BST-1 and SDF-1, were also induced. In this setting, rapamycin suppressed the coordinated proadhesive and proinflammatory gene expression pattern next to down-regulation of genes related to metabolism, proliferation, and apoptosis. Our study shows that mechanical injury leads to induction of a proinflammatory, proadhesive gene expression pattern in the vessel wall even in absence of leukocytes. These molecular events could provide a basis for the recruitment of leukocytes and HPC. By inhibiting the expression of such genes, rapamycin may lead to a reduced recruitment of leukocytes and HPC after vascular injury, an effect that may play a decisive role for its effectiveness in reducing restenosis.

Stem cell mobilization by granulocyte colony-stimulating factor in patients with acute myocardial infarction: a randomized controlled trial.

CONTEXT: Experimental studies and early phase clinical trials suggest that transplantation of blood-derived or bone marrow-derived stem cells may improve cardiac regeneration and neovascularization after acute myocardial infarction. Granulocyte colony-stimulating factor (G-CSF) induces mobilization of bone marrow stem cells. OBJECTIVE: To assess the value of stem cell mobilization by G-CSF therapy in patients with acute myocardial infarction. DESIGN, SETTING, AND PATIENTS: Randomized, double-blind, placebo-controlled trial of patients diagnosed with ST-segment elevation acute myocardial infarction who had successful reperfusion by percutaneous coronary intervention within 12 hours after onset of symptoms in Germany between February 24, 2004, and February 2, 2005. INTERVENTIONS: Patients were randomly assigned to receive subcutaneously either a daily dose of 10 microg/kg of G-CSF or placebo for 5 days. MAIN OUTCOME MEASURES: The primary end point was reduction of left ventricular infarct size according to technetium Tc 99m sestamibi scintigraphy performed at baseline and at 4 to 6 months after randomization. Secondary end points included improvement of left ventricular ejection fraction measured by magnetic resonance imaging and the incidence of angiographic restenosis. RESULTS: Of the 114 patients, 56 were assigned to receive treatment with G-CSF and 58 were assigned to receive placebo. Treatment with G-CSF produced a significant mobilization of stem cells. Between baseline and follow-up, left ventricular infarct size according to scintigraphy was reduced by a mean (SD) of 6.2% (9.1%) in the G-CSF group and 4.9% (8.9%) in the placebo group (P = .56) and left ventricular ejection fraction was improved by 0.5% (3.8%) in the G-CSF group and 2.0% (4.9%) in the placebo group (P = .14). Angiographic restenosis occurred in 19 (35.2%) of 54 patients in the G-CSF group and in 17 (30.9%) of 55 patients in the placebo group (P = .79). The most common adverse event among patients assigned to G-CSF was mild to moderate bone pain and muscle discomfort. CONCLUSION: Stem cell mobilization by G-CSF therapy in patients with acute myocardial infarction and successful mechanical reperfusion has no influence on infarct size, left ventricular function, or coronary restenosis. CLINICAL TRIAL REGISTRATION: ClinicalTrials.gov Identifier: NCT00126100.

Randomized, double-blind, placebo-controlled trial of oral sirolimus for restenosis prevention in patients with in-stent restenosis: the Oral Sirolimus to Inhibit Recurrent In-stent Stenosis (OSIRIS) trial.

BACKGROUND: Despite recent advances in interventional cardiology, including the introduction of drug-eluting stents for de novo coronary lesions, the treatment of in-stent restenosis (ISR) remains a challenging clinical issue. Given the efficacy of systemic sirolimus administration to prevent neointimal hyperplasia in animal models and to halt and even reverse the progression of allograft vasculopathy, the aim of the present double-blind, placebo-controlled study was to evaluate the efficacy of a 10-day oral sirolimus treatment with 2 different loading regimens for the prevention of recurrent restenosis in patients with ISR. METHODS AND RESULTS: Three hundred symptomatic patients with ISR were randomly assigned to 1 of 3 treatment arms: placebo or usual-dose or high-dose sirolimus. Patients received a cumulative loading dose of 0, 8, or 24 mg of sirolimus 2 days before and the day of repeat intervention followed by maintenance therapy of 2 mg/d for 7 days. Angiographic restenosis at 6-month angiography was the primary end point of the study. Restenosis was significantly reduced from 42.2% to 38.6% and to 22.1% in the placebo, usual-dose, and high-dose sirolimus groups, respectively (P=0.005). Similarly, the need for target vessel revascularization was reduced from 25.5% to 24.2% and to 15.2% in the placebo, usual-dose, and high-dose groups, respectively (P=0.08). The sirolimus blood concentration on the day of the procedure correlated significantly with the late lumen loss at follow-up (P<0.001). CONCLUSIONS: In patients with ISR, an oral adjunctive sirolimus treatment with an intensified loading regimen before coronary intervention resulted in a significant improvement in the angiographic parameters of restenosis.

Combinatorial G-CSF/AMD3100 treatment in cardiac repair after myocardial infarction.

AIMS: Several studies suggest that circulating bone marrow derived stem cells promote the regeneration of ischemic tissues. For hematopoietic stem cell transplantation combinatorial granulocyte-colony stimulating factor (G-CSF)/Plerixafor (AMD3100) administration was shown to enhance mobilization of bone marrow derived stem cells compared to G-CSF monotherapy. Here we tested the hypothesis whether combinatorial G-CSF/AMD3100 therapy has beneficial effects in cardiac recovery in a mouse model of myocardial infarction. METHODS: We analyzed the effect of single G-CSF (250 µg/kg/day) and combinatorial G-CSF/AMD3100 (100 µg/kg/day) treatment on cardiac morphology, vascularization, and hemodynamics 28 days after permanent ligation of the left anterior descending artery (LAD). G-CSF treatment started directly after induction of myocardial infarction (MI) for 3 consecutive days followed by a single AMD3100 application on day three after MI in the G-CSF/AMD3100 group. Cell mobilization was assessed by flow cytometry of blood samples drawn from tail vein on day 0, 7, and 14. RESULTS: Peripheral blood analysis 7 days after MI showed enhanced mobilization of white blood cells (WBC) and endothelial progenitor cells (EPC) upon G-CSF and combinatorial G-CSF/AMD3100 treatment. However, single or combinatorial treatment showed no improvement in survival, left ventricular function, and infarction size compared to the saline treated control group 28 days after MI. Furthermore, no differences in histology and vascularization of infarcted hearts could be observed. CONCLUSION: Although the implemented treatment regimen caused no adverse effects, our data show that combinatorial G-CSF/AMD therapy does not promote myocardial regeneration after permanent LAD occlusion.

Influence of fibre diameter and orientation of electrospun copolyetheresterurethanes on smooth muscle and endothelial cell behaviour.

Polymers exhibiting cell-selective effects represent an extensive research field with high relevance for biomedical applications e.g. in the cardiovascular field supporting re-endothelialization while suppressing smooth muscle cell overgrowth. Such an endothelial cell-selective effect could be recently demonstrated for a copolyetheresterurethane (PDC) containing biodegradable poly(p-dioxanone) and poly(ε-caprolactone) segments, which selectively enhanced the adhesion of human umbilical vein endothelial cells (HUVEC) while suppressing the attachment of smooth muscle cells (SMC). In this study we investigated the influence of the fibre orientation (random and aligned) and fibre diameter (2 µm and 500 nm) of electrospun PDC scaffolds on the adhesion, proliferation and apoptosis of HUVEC and SMC. Adhesion, viability and proliferation of HUVEC was diminished when the fibre diameter was reduced to a submicron scale, while the orientation of the microfibres did only slightly influence the cellular behaviour. In contrast, a submicron fibre diameter improved SMC viability. In conclusion, PDC scaffolds with micron-sized single fibres could be promising candidate materials for cell-selective stent coatings.

Smooth muscle and endothelial cell behaviour on degradable copolyetheresterurethane films.

Stent thrombosis and restenosis after drug-eluting stent (DES) implantation remains a relevant problem in the cardiovascular field. The polymer-based biomaterial (e.g. stent coating) requirements are comprehensive, since the polymeric material ideally should ensure an effective re-endothelialization by recruiting endothelial cells (EC) and endothelial progenitor cells (EPC). Simultaneously, the polymer should effectively prevent adherence of smooth muscle cells (SMC) and thereby inhibiting restenosis. The aim of this study was to gain a basic understanding on the interaction of SMC and human umbilical vein endothelial cells (HUVEC) with nonporous polymer films. A multifunctional copolyetheresterurethane (PDC) was chosen as candidate material: PDC consists of poly(p-dioxanone) (PPDO) and poly(ε-caprolactone)-segments (PCL). In our study it was compared to the degradable PPDO homopolymer and poly(vinylidene fluoride-co-hexafluoropropene) (PVDF), an established coating material of DES in clinical applications intended for longterm applications. The films were analyzed according to their thermomechanical and surface properties before being examined in contact with HUVEC and SMC concerning cell viability, proliferation and adhesion. Experimental results showed that adhesion could be improved for HUVEC on PDC compared to PPDO and PVDF. In contrast, SMC attachment is largely suppressed on PDC polymeric films indicating a cell-specific response of HUVEC towards PDC. In conclusion, PDC represents a promising candidate material for future cardiovascular applications like e.g. biodegradable (PDC) stent coatings.

Viability, proliferation and adhesion of smooth muscle cells and human umbilical vein endothelial cells on electrospun polymer scaffolds.

A major clinical problem of high relevance in the cardiovascular field is late stent thrombosis after implantation of drug eluting stents (DES). Clinical widely used DES currently utilize durable polymer coatings, which can induce persistent arterial wall inflammation and delayed vascular healing resulting in an impaired endothelialization. In this study we explored the interaction of smooth muscle cells (SMC) and human umbilical vein endothelial cells (HUVEC) with electrospun scaffolds prepared from resorbable polyetheresterurethane (PDC) and poly(p-dioxanone) (PPDO), as well as polyetherimide (PEI), which can be surface modified, in comparison to poly(vinylidene fluoride-co-hexafluoropropene) (PVDF) as reference material, which is established as coating material of DES in clinical applications. Our results show that adhesion could be improved for HUVEC on PDC, PPDO and PEI compared to PVDF, whereas almost no SMC attached to the scaffolds indicating a cell-specific response of HUVEC towards the different fibrous structures. Proliferation and apoptosis results revealed that PPDO and PEI have no significant negative influence on vitality and cell cycle behaviour compared to PVDF. Hence, they represent promising candidates for temporary blood vessel support that induce HUVEC attachment and prevent SMC proliferation.

Coronary stenting after myocardial infarction during twin pregnancy--a case report.

OBJECTIVE: We report the case of a 46-year-old woman presenting with acute chest pain in the 20th week of a twin pregnancy after oocyte donation. CASE REPORT: The Patient's medical history comprised several cardiovascular risk factors, such as hypertension, obesity, hypercholesterolemia, smoking, and a positive family history. After diagnosis of myocardial infarction, coronary catheterization and stenting was performed. Ten weeks later, Cesarean was indicated because of severe superimposed preeclampsia with lung edema. Mother and babies recovered uneventfully. CONCLUSION: In respect to increasing rates of higher maternal age and obesity during pregnancy, more attention to maternal health is required, particularly in programs for assisted reproductive techniques.

Expression of CXCR4, VLA-1, LFA-3 and transducer of ERB in G-CSF-mobilised progenitor cells in acute myocardial infarction.

G-CSF induced mobilisation of progenitor cells is a multistep processes involving chemokines, growth factors, matrix-degrading enzymes, and cell adhesive interactions mediated by specific receptors on haematopoietic cells. This study's aim was to investigate progenitor cells mobilised during myocardial infarction after treatment with granulocyte-stimulating factor (G-CSF). In the randomised, double-blind, placebo-controlled REVIVAL-2 study, 114 patients with acute myocardial infarction were included. Five days after successful percutaneous coronary intervention patients received either 10 microg/kg G-CSF (n=56) or placebo (n=58) subcutaneously for five days. Venous blood samples were analysed on day(s) 1, 3, 5 and 7 after therapy, and progenitor cell mobilisation and surface expression of VLA-4, LFA-1 and CXCR-4 was measured on circulating progenitor cells using flow cytometry. G-CSF induced a significant increase in circulating progenitor cells (72 +/- 20 cells/microl vs. 4.5 +/- 0.8 cells/microl, p<0.05). Surface expression of LFA-1, VLA-4 and CXCR4 on progenitor cells was decreased by 44%, 49% and 60% after G-CSF as compared to placebo (p<0.05). In accordance, mRNA expression of CXCR4 was reduced. Moreover, anti-proliferative transducer of ERB (TOB) mRNA was decreased, suggesting an increased proliferative potential of the mobilised progenitor cells. Decreased expression of adhesion and chemokine receptors on G-CSF mobilised progenitor cells in acute myocardial infarction may alter the homing capacity of circulating cells to the myocardium.

Myocardial gene expression of matched hibernating and control tissue from patients with ischemic left ventricular dysfunction.

Limited data are available in humans regarding the molecular biology of hibernating myocardium (HM). The aim of this study was to identify gene expression patterns distinctive for human HM. We compared in patients with ischemic left ventricular dysfunction the gene expression profile of myocardial biopsies from HM (n = 5), as identified by positron emission tomography, with expression profiles of matched biopsies from normally perfused myocardium by using cDNA array analysis. Gene-specific polymerase chain reaction of selected genes and immunohistochemical staining of desmoplakin were used to validate our technical approach. Of 4171 transcripts examined, we identified 86 to be differentially expressed. Compared to normally perfused myocardium, 21 genes showed an increased expression and 65 genes a decreased expression in HM. Functional clustering revealed changes in the expression of genes associated with transcription, protein modification and phosphorylation, regulation of apoptosis, and intercellular communication. Besides the reported upregulation of beta-adrenergic receptor kinase-1 in heart failure, we observed new gene expression patterns, such as the upregulation of fas-activated serine/threonine kinase (FAST) or reduced expression of desmoplakin. Downregulation of desmoplakin in cardiomyocytes from HM was also seen on the protein level. Gene expression analysis provided novel insights into the pathophysiological changes of HM. Impaired intercellular communication as suggested by decreased expression of desmoplakin may be an important feature of contractile dysfunction in HM.

Stem cell mobilization by granulocyte colony-stimulating factor for myocardial recovery after acute myocardial infarction: a meta-analysis.

OBJECTIVES: The objective of this meta-analysis was to evaluate the effect of stem cell mobilization by granulocyte colony-stimulating factor (G-CSF) on myocardial regeneration on the basis of a synthesis of the data generated by randomized, controlled clinical trials of G-CSF after acute myocardial infarction (AMI). BACKGROUND: Experimental studies and early-phase clinical trials suggest that stem cell mobilization by G-CSF may have a positive impact on cardiac regeneration after AMI. The role of G-CSF in patients with AMI remains unclear considering the inconsistent results of several clinical trials. METHODS: For our analysis, PubMed, the Cochrane Central Register of Controlled Trials, conference proceedings from major cardiology meetings, and Internet-based sources of information on clinical trials in cardiology from January 2003 to August 2007 served as sources. Two reviewers independently identified studies and abstracted data on sample size, baseline characteristics, and outcomes of interest. Eligible studies were randomized trials with stem cell mobilization by G-CSF after reperfused AMI that reported data regarding the change in left ventricular ejection fraction (LVEF) at follow-up. RESULTS: Ten trials using stem cell mobilization by G-CSF, including 445 patients, met the inclusion criteria. Significant improvement in LVEF at follow-up was observed in both the G-CSF and placebo groups. Compared with placebo, stem cell mobilization by G-CSF did not enhance the improvement of LVEF at follow-up (mean difference 1.32% [95% confidence interval -1.52 to 4.16; p = 0.36]). Moreover, the mean difference of reduction of infarct size between the treatment and placebo groups was -0.15 (95% confidence interval -0.38 to 0.07, p = 0.17). CONCLUSIONS: Cumulatively, available evidence does not support a beneficial effect of G-CSF in patients with AMI after reperfusion.