Granulocyte-colony stimulating factor augments neovascularization induced by bone marrow transplantation in rat hindlimb ischemia.

Because granulocyte-colony stimulating factor (G-CSF) mobilizes bone marrow cells including endothelial progenitor cells, we examined whether G-CSF augments angiogenesis and collateral vessel formation induced by bone marrow-mononuclear cells transplantation (BMT). Unilateral hindlimb ischemia was surgically induced in Lewis rats. One week after surgery, administration of 100 mg/kg per day G-CSF significantly increased the laser Doppler blood perfusion index (LDBPI), number of angiographically detectable collateral vessels (angiographic score), and capillary density determined by alkaline phosphatase staining. In the BMT group (1 x 10(7) cells/rat) and the group with combined G-CSF treatment and BMT, LDBPI was significantly increased compared with that in the vehicle-treated group. In the BMT group, neovascularization was significantly increased as evidenced by the angiographic score and capillary density compared with the vehicle-treated group. Furthermore, the combination of G-CSF treatment and BMT augmented neovascularization compared with BMT alone, as evidenced by the angiographic score and capillary density. Moreover, G-CSF significantly increased vascular endothelial growth factor mRNA and fibroblast growth factor-2 mRNA in hindlimb muscle. In conclusion, G-CSF was found to augment neovascularization in rat hindlimb ischemia. Combined use of G-CSF treatment and BMT may be a useful strategy for therapeutic neovascularization in ischemic tissues.

Vascular endothelial growth factor-expressing mesenchymal stem cell transplantation for the treatment of acute myocardial infarction.

OBJECTIVE: Vascular endothelial growth factor (VEGF) plays an important role in inducing angiogenesis. Mesenchymal stem cells (MSCs) may have potential for differentiation to several types of cells, including myocytes. We hypothesized that transplantation of VEGF-expressing MSCs could effectively treat acute myocardial infarction (MI) by providing enhanced cardioprotection, followed by angiogenic effects in salvaging ischemic myocardium. METHODS AND RESULTS: The human VEGF165 gene was transfected to cultured MSCs of Lewis rats using an adenoviral vector. Six million VEGF-transfected and LacZ-transfected MSCs (VEGF group), LacZ-transfected MSCs (control group), or serum-free medium only (medium group) were injected into syngeneic rat hearts 1 hour after left coronary artery occlusion. At 1 week after MI, MSCs were detected by X-gal staining in infarcted region. High expression of VEGF was immunostained in the VEGF group. At 28 days after MI, infarct size, left ventricular dimensions, ejection fraction, E wave/A wave ratio and capillary density of the infarcted region were most improved in the VEGF group, compared with the medium group. Immunohistochemically, alpha-smooth muscle actin-positive cells were most increased in the VEGF group. CONCLUSIONS: This combined strategy of cell transplantation with gene therapy could be a useful therapy for the treatment of acute MI.

Role of c-Jun NH2-terminal kinase in G-protein-coupled receptor agonist-induced cardiac plasminogen activator inhibitor-1 expression.

Plasminogen activator inhibitor-1 (PAI-1) has been implicated as a contributing risk factor for cardiovascular disease. However, little is known about molecular mechanisms of cardiac PAI-1 gene expression. To elucidate these mechanisms, dominant negative mutants of c-Jun NH(2)-terminal kinase (JNK), p38MAPK, apoptosis signal-regulating kinase-1 (ASK-1) and c-Jun were overexpressed in rat neonatal ventricular cardiac myocytes and fibroblasts by adenovirus vector to abrogate the activation of the corresponding endogenous proteins. One hundred nmol/l of angiotensin II significantly enhanced the JNK and p38MAPK activities of cardiomyocytes (2.3-fold and 1.9-fold, P < 0.05) and fibroblasts (3.2-fold and 2.5-fold, P < 0.05). At 3 h after stimulation, angiotensin II was found to have significantly increased PAI-1 mRNA, by 5.2-fold in cardiomyocytes and by 9.7-fold in fibroblasts. Dominant negative mutants of JNK, ASK-1 and c-Jun significantly inhibited PAI-1 mRNA expression and protein synthesis in both cardiomyocytes and fibroblasts, whereas a dominant negative mutant of p38MAPK did not change this expression. Moreover, a dominant negative mutant of JNK also significantly prevented the induction of PAI-1 mRNA expression by 100 nmol/l endothelin-1 and 10 micromol/l phenylephrine. In conclusion, G-protein-coupled receptor agonist-induced PAI-1 expression is partially mediated through JNK activation.

Fabry disease female proband with clinical manifestations similar to hypertrophic cardiomyopathy.

Fabry's disease is an X-linked inborn error of glycosphingolipid catabolism, resulting from a deficiency in alpha-galactosidase A (alpha-Gal A). A 56-year-old Japanese woman was at first suspected of having hypertrophic cardiomyopathy. The patient and her son had alpha-Gal A activity in leukocytes that was remarkably below the limit of controls. DNA analysis of the alpha-Gal A gene revealed a novel missense mutation at codon 19 in exon 1, resulting in leucine-to-proline substitution. As a result she was confirmed as a classic Fabry heterozygote. Recent advances in enzyme replacement therapy can reverse the storage of glycosphingolipids in Fabry's disease. Thus, in patients with cardiac hypertrophy, it is important to differentiate Fabry's disease from other causes of hypertrophy. Therefore, it is necessary to measure alpha-Gal A activity in all suspected cases and to analyze genetic abnormalities in heterozygotes.

Involvement of apoptosis signal-regulating kinase-1 on angiotensin II-induced monocyte chemoattractant protein-1 expression.

OBJECTIVE: Monocyte chemoattractant protein 1 (MCP-1) could contribute to enhanced leukocyte recruitment and activation resulting in chronic tissue damage. However, little is known about the molecular mechanisms of cardiac MCP-1 expression. To elucidate these molecular mechanisms, angiotensin II-induced expression of MCP-1 was examined in cultured rat neonatal ventricular cardiomyocytes and fibroblasts by adenovirus gene transfer. METHODS AND RESULTS: MCP-1 mRNA increased 3.6-fold in cardiac fibroblasts at 3 hours after 100 nmol/L angiotensin-II stimulation (P<0.01), whereas MCP-1 mRNA in cardiomyocytes was unchanged. Angiotensin II significantly enhanced JNK, p38MAPK, and nuclear factor-kappaB (NF-kappaB) activities of cardiac fibroblasts. Wild-type ASK-1 increased MCP-1 expression of cardiac fibroblasts, whereas dominant negative mutant of ASK-1 (DN-ASK), dominant negative mutant of p38MAPK (DN-p38MAPK), and pyrrolidine dithiocarbamate significantly inhibited such expression. The increased MCP-1 mRNA expression in wild-type ASK-1 transfected fibroblasts was inhibited by cotransfection with adenovirus expressing DN-p38MAPK. On the contrary, the decreased MCP-1 mRNA expression in DN-ASK transfected cells was increased by cotransfection with adenovirus expressing constitutively active MKK6. CONCLUSIONS: Angiotensin II induced MCP-1 gene expression in cardiac fibroblasts. The angiotensin II-induced activation of ASK-1 followed by p38MAPK and NF-kappaB signaling in cardiac fibroblasts is partially involved in myocardial MCP-1 expression.

Identification of cardiac sarcoidosis with (13)N-NH(3)/(18)F-FDG PET.

UNLABELLED: To our knowledge, no study investigating the usefulness of cardiac PET for detection of myocardial involvement of sarcoidosis is available. We investigated whether (13)N-NH(3)/(18)F-FDG PET could identify cardiac involvement in patients with sarcoidosis. METHODS: Seventeen patients with cardiac sarcoidosis underwent cardiac (13)N-NH(3)/(18)F-FDG PET under fasting condition. Systemic sarcoidosis was diagnosed by histologically proven noncaseating epithelioid granuloma, and cardiac sarcoidosis was diagnosed according to the Japanese Ministry of Health and Welfare guidelines for diagnosing cardiac sarcoidosis. RESULTS: Only 6 patients exhibited myocardial (201)Tl defects and only 3 patients exhibited abnormal (67)Ga accumulation in the heart. Thirteen patients exhibited (13)N-NH(3) defects, and 14 patients exhibited increased (18)F-FDG uptake in the heart; 12 patients exhibited both (13)N-NH(3) defects and increased (18)F-FDG uptake, 2 patients exhibited increased (18)F-FDG uptake but no (13)N-NH(3) defect, and 1 patient exhibited (13)N-NH(3) defects but no increased (18)F-FDG uptake. (13)N-NH(3) defects were observed frequently in the basal anteroseptal wall of the left ventricle, and increased (18)F-FDG uptake was observed frequently in the basal and midanteroseptal-lateral wall of the left ventricle. Involvement of the apex was rare. Seven patients were treated with steroid hormone and underwent follow-up cardiac PET 1 mo after steroid therapy. (13)N-NH(3) defects exhibited no significant change after steroid therapy, whereas increased (18)F-FDG uptake was markedly diminished in size and intensity in 5 patients and disappeared completely in 2 patients. CONCLUSION: Our findings suggest that cardiac (13)N-NH(3)/(18)F-FDG PET is the most useful method both for the identification of cardiac involvement of sarcoidosis and for the assessment of cardiac sarcoidosis disease activity.

Unruptured aneurysm of the sinus of valsalva with Behçet's disease.

A 52-year-old Japanese man who had suffered from Behçet's disease since the age of 45 years was admitted to hospital for evaluation of syncope and heart murmur. Echocardiography and aortography revealed severe aortic regurgitation and cystic masses under the right coronary cusp and the left ventricular outflow tract, but no shunt jet. He was diagnosed with unruptured aneurysm of the sinus of Valsalva, and surgical closure of the orifice of the aneurysm was performed. The diameter of the orifice was 11 mm and the aneurysm was 15 mm in depth, and consisted of 2 chambers. Because the aortic regurgitation was reduced after patch closure of the orifice, aortic valve replacement was not performed. Unruptured aneurysm of the sinus of Valsalva is a rare clinical lesion, but patients with active inflammatory disease of the aorta, such as in Behçet's disease, should have periodic echocardiography for early detection of an aneurysm or valvular involvement, even if there are not any symptoms.