Histology and histopathology Vol.25, nº5 (2010)
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- PublicationOpen AccessVitamin E action on oxidative state, endothelial function and morphology in long-term myocardial preservation(Murcia : F. Hernández, 2010) Álvarez-Ayuso, Lourdes; García Gómez-Heras, Soledad; Jorge, Eduardo; Guardiola, José M.; Torralba, Amalia; Granado, Fernando; Millán, Isabel; Roda, Jorge R.; Calero, Patricia; Fernández-García, Héctor; García-Poblete, Eduardo. This study assesses the effects of a vitamin E analogue, Trolox, on the oxidative state, endothelial function and morphology in experimental heart transplantation. Heterotopic heart transplantation was carried out in pigs: untreated after 2 and 24 hours of ischemia and treated with Trolox after 24 hours of ischemia. Prolonged preservation of donor hearts was achieved with continuous perfusion and University of Wisconsin solution, in which acid-base balance and enzymes were determined during the procedure. In recipients, hemodynamic and biochemical parameters were determined at baseline and during reperfusion. Trolox diminished the pH of the preservation solution (p<0.01), the left ventricle of the transplanted heart recovered a systolic pressure equaling that of the 2h group and higher than that of the untreated 24h group (p<0.01), the antioxidant levels were not decreased and the glutathione reductase level was maintained throughout the first part of reperfusion. In this group also there was a direct correlation between the concentration of this enzyme and the antioxidant levels (p<0.001). Although the endothelin concentrations increased, the change was less marked in the Trolox group than in the untreated 24h group (p<0.01). Morphologically, mitochondria and myocardial vessels presented a normal structure in the Trolox group, and interstitial edema, inflammatory infiltrate and contraction bands were less prominent than in the untreated group. All these effects indicate that Trolox protected the transplanted heart, at least partially, against ischemia-reperfusion injury
- PublicationOpen AccessSex-dependent effect of liver growth factor on atherosclerotic lesions and fatty liver disease in apolipoprotein E knockout mice(Murcia : F. Hernández, 2010) Surra, Joaquin C.; Guillén, Natalia; Barranquero, Cristina; Arbonés Mainar, José M.; Navarro, María A.; Gascón, Sonia; Arnal, Carmen; Godino, Javier; Guzmán, Mario A.; Díaz-Gil, Juan J.; Osada, JesúsObjective: Since the hepatic mitogen, liver growth factor (LGF), improves vascular structure and function in a hypertensive rat model and exhibits antioxidant activity, it may play a role in the development of atherosclerosis. Methods: To test this hypothesis, 14 male and 11 female apolipoprotein E (apoE)-deficient mice with a C57BL/6J genetic background were injected intraperitoneally twice a week with 1.7 µg of LGF per mouse for ten weeks. Plasma carbohydrates, inflammatory and lipid parameters, apolipoproteins A-I and A-II and paraoxonase activity were assessed at the end of the experimental period. Histological and chemical analyses of the livers and quantification of aortic atherosclerotic lesions were also carried out. Results: LGF administration changed neither plasma lipid nor inflammatory parameters. ApoA-I and arylesterase activity were not affected by LGF either, while apoA-II decreased significantly in males but not in females. Plasma apoA-II correlated positively with liver fat in males but negatively in females. Atherosclerotic area lesions in males receiving LGF were 25% lower than in control mice. Likewise, a significant reduction of fatty liver disease was also observed in males in association with decreased levels of insulin, leptin and resistin. Conclusion: These results indicate that administration of LGF modulates atherosclerotic lesions in a sex-dependent manner. This effect is independent of plasma cholesterol, triglycerides, IL-6, MCP-1 and TNF-α and is related to a remodelling of HDL particles characterised by a decrease in apoA-II induced by changes in hepatic mRNA expression. Hence, LGF administration could be used as a safe alternative to control fatty liver disease and atherosclerosis in males
- PublicationOpen AccessSpecification of arterial, venous, and lymphatic endothelial cells during embryonic development(Murcia : F. Hernández, 2010) Kume, TsutomuThe groundbreaking discovery about arterial and venous expression of ephrinB2 and EphB4, respectively, in early embryonic development has led to a new paradigm for vascular research, providing compelling evidence that arterial and venous endothelial cells are established by genetic mechanisms before circulation begins. For arterial specification, vascular endothelial growth factor (VEGF) induces expression of Notch signaling genes, including Notch1 and its ligand, Delta-like 4 (Dll4), and Foxc1 and Foxc2 transcription factors directly regulate Dll4 expression. Upon activation of Notch signaling, the Notch downstream genes, Hey1/2 in mice or gridlock in zebrafish, further promote arterial differentiation. On the other hand, the orphan nuclear receptor COUP-TFII is a determinant factor for venous specification by inhibiting expression of arterial specific genes, including Nrp1 and Notch. After arterial and venous endothelial cells differentiate, a subpopulation of venous endothelial cells is thought to become competent to acquire lymphatic endothelial cell fate by progressively expressing the transcription factors Sox18 and Prox1 to differentiate into lymphatic endothelial cells. Therefore, it has now evident that arterial-venous cell fate determination and subsequent lymphatic development are regulated by the multi-step regulatory system associated with the key signaling pathways and transcription factors. Furthermore, new signaling molecules as additional regulators in these processes have recently been identified. As the mechanistic basis for a link between signaling pathways and transcriptional networks in arterial, venous and lymphatic endothelial cells begins to be uncovered, it is now time to summarize the literature on this exciting topic and provide perspectives for future research in the field.
- PublicationOpen AccessVascular wall-resident stem cells(Murcia : F. Hernández, 2010) Klein, Diana; Hohn. Hans-Peter; Kleff, Veronika; Tilki, Derya; Ergün, SüleymanNew vessels in the adult have been considered to be formed not only by angiogenesis, but also by postnatal vasculogenesis via endothelial progenitor cells (EPCs). However, it is still a matter of debate as to what extent the EPCs contribute to new vessel formation in the adult. While the role of the circulating and bone marrow-derived EPCs has intensively been studied, the contribution of the vascular wall itself was neglected for a long time. Evidence published in the last few years strongly suggests the existence of different stem and progenitor cell types in the vascular wall. Particularly, the presence of EPCs and smooth muscle progenitor cells (SMPCs) in distinct zones of the vascular wall supports the hypothesis that not only BM- or C-EPCs, but also vascular wall-resident stem cells (VW-SCs) might contribute to new vessel formation and vascular wall morphogenesis. However, the differentiation potential of the VW-SCs, e.g. whether a VW-SC is able to give rise to a complete hierarchy of vascular progenitors still remains to be studied. This review will provide a survey about the VW-SCs and their potential impact in vascular biology
- PublicationOpen AccessThe internal thoracic artery as a transitional type of artery: a morphological and morphometric study(Murcia : F. Hernández, 2010) Labudović Borović, Milica; Borović, Saša; Perić, Miodrag; Vuković, Petar; Marinković, Jelena; Todorovic, Vera; Radak, Ðorde; Lackovic, VesnaCoronary artery by-pass grafting (CABG) with arterial grafts is widely accepted as the procedure of choice in the treatment of coronary ischemic disease. It brings back focus on morphological studies of arteries used as conduits in this procedure. One of the most frequently used CABG grafts is the internal thoracic artery with an excellent graft prognosis and patency rate. The aim of the study was a detailed morphological and morphometric description of the internal thoracic artery with an emphasis on its basic histological structure and its changes in aging and atherosclerosis. Therefore, 42 full-length arteries were obtained during forensic autopsies from 27 persons, aged between 20 and 81 years, who had died from non-vascular causes. The arteries were classified into three different age groups. Analysis of the serial arterial segments has shown that the internal thoracic artery is an artery of the transitional type whose media is organized into two layers: the internal, muscular layer and the external layer with spirally oriented elastic lamellae and smooth muscle cells in between. The number of elastic lamellae progressively decreases throughout the length of the examined arteries. As opposed to previous assumptions, we have proven that the grade of atherosclerosis is independent of the number of elastic lamellae in the external media. Perfectly formed elastic lamellae are not a persistent feature of the internal thoracic artery, as previously claimed. We have confirmed that the thickness of elastic lamellae decreases, while the number and the size of their fenestrations steadily increase with aging
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