DigitalUM :: Browsing by Subject "Endothelial cells"

Browsing by Subject "Endothelial cells"

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Open Access
Decorin and biglycan expression: its relation with endothelial heterogeneity
(Murcia: F. Hernández, 2011) Calabrese, Graciela C.; Gazzaniga, Silvina; Oberkersch, Roxana; Wainstok, Rosa
Decorin and biglycan proteoglycans play important roles in the organization of the extracellular matrix, and in the regulation of cell adhesion and migration. Given morphological and functional endothelial heterogeneity, information is needed regarding whether endothelial cells (ECs) from different vascular beds possess different profiles of proteoglycan constituents of the basement membranes. Here, we report that endothelia from different murine organs and EC lines derived thereof produce and secrete different patterns of proteoglycans. A faint colocalization between decorin and PECAM/CD31 was found on tissue sections from mouse heart, lung and kidney by immunofluorescence. Three EC lines derived from these organs produced decorin (100-kDa) and its core protein (45-kDa). Extracellular decorin recognition in culture supernatant was only possible after chondroitin lyase digestion suggesting that the core protein of secreted proteoglycan is more encrypted by glycosaminoglycans than the intracellular one. Heart and lung ECs were able to produce and release decorin. Kidney ECs synthesized the proteoglycan and its core protein but no secretion was detected in culture supernatants. Although biglycan production was recorded in all EC lines, secretion was almost undetectable, consistent with immunofluorescence results. In addition, no biglycan secretion was detected after EC growth supplement treatment, indicating that biglycan is synthesized, secreted and quickly degraded extracellularly by metalloproteinase-2. Low molecularmass dermatan sulfate was the predominant glycosaminoglycan identified bound to the core protein. ECs from different vascular beds, with differences in morphology, physiology and cell biology show differences in the proteoglycan profile, extending their heterogeneity to potential differences in cell migration capacities.
Open Access
Electron microscopic analysis of glucose-induced endothelial damage in primary culture: Possible mechanism and prevention
(Murcia : F. Hernández, 2006) Mandal, A.K.; Ping, T.; Caldwell, S.; Bagnell, R.; Hiebert, L.M.
We previously reported that high glucose treated cultured endothelial cells (ECs) showed intercellular gaps by transmission electron microscopy (TEM). These gaps were abrogated with insulin and/or heparin treatment. Our aims were to assess the severity of injury in ECs treated with high glucose for variable duration, and to further study the protective effects of insulin and/or heparin. Cells were also treated with Lbuthionine sulfoximine (BSO), a glutathione inhibitor, to help understand the mechanism of high glucose injury. Primary porcine ECs were treated with high glucose (30 mM) for 2, 6 or 10 days; and glucose plus insulin (1 U/ml), glucose plus heparin (5 µg/ml), glucose plus insulin plus heparin for 6 days. ECs were treated with BSO (0.001-0.05 mM) for 2 days. Pellets from trypsinized cells were processed for TEM. High glucose treatment revealed apoptosis or necrosis showing variable cell size, abnormal nuclei, condensation of nuclear chromatin, few mitochondria, cell membrane disruption and needle-shaped structures. Changes increased with duration of exposure. In high glucose plus heparin or insulin treated cultures at least one-half of the cells appeared normal. Most ECs were intact when treated with high glucose plus insulin plus heparin. BSO treatment showed dose-dependent changes with low doses showing apoptosis whereas higher doses revealed necrosis similar to high glucose treatment for 6 or 10 days. High glucose-induced EC injury increased with duration of exposure. These data demonstrate that high glucose injury resembles that of BSO treatment, suggesting that glutathione depletion may be involved in EC injury. Insulin and/or heparin protect against high glucose-induced injury.
Open Access
Endothelial cell activation mediated by cold ischemia-released mitochondria is partially inhibited by defibrotide and impacts on early allograft function following liver transplantation
(Elsevier, 2023-09-18) Villalba-Lopez, Francisco; Mateo, Sandra V.; Vidal-Correoso, Daniel; Jover-Aguilar, Marta; Alconchel, Felipe; Martínez-Alarcón, Laura; López-López, Víctor; Rios-Zambudio, Antonio; Cascales, Pedro; Pons Miñano, José Antonio; Ramírez, Pablo; Baroja-Mazo, Alberto; García Bernal, David; Pelegrín Vivancos, Pablo; Medicina
DAMPs (danger-associated molecular patterns) are self-molecules of the organism that appear after damage. The endothelium plays several roles in organ rejection, such as presenting alloantigens to T cells and contributing to the development of inflammation and thrombosis. This study aimed to assess whether DAMPs present in the organ preservation solution (OPS) after cold ischemic storage (CIS) contribute to exacerbating the endothelial response to an inflammatory challenge and whether defibrotide treatment could counteract this effect. The activation of cultured human umbilical vein endothelial cells (HUVECs) was analyzed after challenging with endischemic OPS (eiOPS) obtained after CIS. Additionally, transwell assays were performed to study the ability of eiOPS to attract lymphocytes across the endothelium. The study revealed that eiOPS upregulated the expression of MCP-1 and IL-6 in HUVECs. Moreover, eiOPS increased the membrane expression of ICAM-1and HLA-DR, which facilitated leukocyte migration toward a chemokine gradient. Furthermore, eiOPS demonstrated its chemoattractant ability. This activation was mediated by free mitochondria. Defibrotide was found to partially inhibit the eiOPS-mediated activation. Moreover, the eiOPS-mediated activation of endothelial cells (ECs) correlated with early allograft dysfunction in liver transplant patients. Our finding provide support for the hypothesis that mitochondria released during cold ischemia could trigger EC activation, leading to complications in graft outcomes. Therefore, the analysis and quantification of free mitochondria in the eiOPS samples obtained after CIS could provide a predictive value for monitoring the progression of transplantation. Moreover, defibrotide emerges as a promising therapeutic agent to mitigate the damage induced by ischemia in donated organs.
Open Access
Endothelial progenitor cells in health and disease
(Murcia : F. Hernández, 2005) Ribatti, Doménico; Nico, Beatrice; Crivellato, E.; Vacca, A.
There is currently great excitement and expectation in the stem cell community following the discovery that multipotent stem cells can be cultured from human fetal tissue and retain their ability to give rise to a variety of differentiated cell types found in all three embryonic germ layers. Although the earliest sites of hematopoietic cell and endothelial cell differentiation in the yolk sac blood islands were identified about 100 years ago, cells with hemangioblast properties have not yet been identified in vivo. Endothelial cells differentiate from angioblasts in the embryo and from endothelial progenitor cells, mesoangioblasts and multipotent adult progenitor cells in the adult bone marrow. Circulating endothelial progenitor cells (EPC) have been detected in the circulation after vascular injury and during tumor growth. The molecular and cellular mechanisms underlying EPC recruitment and differentiation are not yet understood, and remain as one of the central issues in stem cell biology. For many years, the prevailing dogma stated that the vessels in the embryo develop from endothelial progenitors, whereas sprouting of vessels in the adult results only from division of differentiated endothelial cells. Recent evidence, however, indicates that EPC contribute to vessel growth in the embryo and in ischemic, malignant or inflammed tissues in the adult, and can even be therapeutically used to stimulate vessel growth in ischemic tissues.
Open Access
Expression of VEGF-C and activation of its receptors VEGFR-2 and VEGFR-3 in trophoblast
(Murcia : F. Hernández, 2001) Dunk, C.; Ahmed, A.
Placental villous development requires the co-ordinated action of angiogenic factors on both endothelial and trophoblast cells. Like vascular endothelial growth factor (VEGF), VEGF-C increases vascular permeability, stimulates endothelial cell proliferation and migration. In the present study, we investigated the expression of VEGF-C and its receptors VEGFR-3 and VEGFR-2 in normal and intrauterine growth-restricted (IUGR) placenta. Immunolocalisation studies showed that like VEGF and VEGFR-1, VEGF-C, VEGFR-3 and VEGFR-2 co-localised to the syncytiotrophoblast, to cells in the maternal decidua, as well as to the endothelium of the large placental blood vessels. Western blot analysis demonstrated a significant decrease in placental VEGF-C and VEGFR-3 protein expression in severe IUGR as compared to gestationallymatched third trimester pregnancies. Conditioned medium from VEGF-C producing pancreatic carcinoma (Suit-2) and endometrial epithelial (Hec-1B) cell lines caused an increased association of the phosphorylated extracellular signal regulated kinase (ERK) in VEGFR-3 immunoprecipitates from spontaneously transformed first trimester trophoblast cells. VEGF121 caused dosedependant phosphorylation of VEGFR-2 in trophoblast cells as well as stimulating DNA svnthesis. In addition. premixing VEGFl with Yheparin sÚlphate proteoglycan wtentiated trooho8ast oroliferation and the association Lf p h ~ s p hw~ith- t i~e V~E~GF R-2 receptor. VEGF165- mediated DNA synthesis was inhibited by anti-VEGFR- 2 neutralising antibody. The results demonstrate functional VEGFR-2 and VEGFR-3 receptors on trophoblast and suggest that the decreased expression of VEGF-C and VEGFR-3 may contribute to the abnormai villous development observed in IUGR placenta.
Open Access
Heme oxygenase-1 and cardiovascular disease
(Murcia : F. Hernández, 2006) Immenschuh, S.; Schröder, H.
Heme oxygenase (HO)-1 is the inducible isoform of the first and rate-controlling enzyme of heme degradation. HO-1 is up-regulated by a host of oxidative stress stimuli and has potent cytoprotective and antiinflammatory functions via decreasing tissue levels of the prooxidant heme along with production of bilirubin and the signaling gas carbon monoxide. This review deals with recent findings that highlight the emerging significance of HO-1 in cardiovascular disease. Evidence is presented on how heme and various oxidative stress stimuli may cause endothelial cell dysfunction and how HO-1 may counteract the detrimental effects of oxidative stress in the endothelium. Recent advances in the understanding of the role of endothelial HO-1 for the regulation of the inflammatory response are summarized, including the modulation of leukocyte recruitment and transmigration through the endothelial barrier. Furthermore, experimental evidence from various cell culture and animal models is discussed which suggests an association of HO-1 with the complex sequence of events that cause atherosclerosis. In the second part of the review we present potential strategies that apply HO- 1 as a therapeutic target in the treatment of cardiovascular disease. Specific inducers of HO-activity which may ultimately lead to the development of clinically relevant pharmacological applications are introduced.
Open Access
Intravascular papillary endothelial hyperplasia (IPEH). Evidence supporting a piecemeal mode of angiogenesis from vein endothelium, with vein wall neovascularization and papillary formation
(Universidad de Murcia. Departamento de Biología Celular e Histología, 2016) Díaz-Flores, L.; Gutiérrez, R.; García Suárez, M.P.; González Alvarez, M.P.; Díaz Flores Jr, L.; Sáez, F.J.; Madrid Cuevas, Juan Francisco
Intravascular papillary endothelial hyperplasia (IPEH) is a reactive process of questioned pathogenesis (primary proliferation of endothelial cells/ECs versus organizing thrombi). The aim of this study is to assess the organization of morphologic patterns, with precise location of neovascularization and papillary distribution in IPEH to clarify the role of the vein wall (mainly vein intimal ECs) in lesion development and papillary formation. We studied 12 cases of IPEH in skin and subcutaneous veins by serial histological sections and immunohistochemical procedures. In four well-structured cases (the remaining cases showed overlapping events), we found four principal histological patterns organized by zone: 1) invaginated vein wall zone with microvascular networks. The intraparietal microvessels presented CD34+ and CD31+ ECs arising from ECs of the vein intima, and αSMA+ pericyte-like cells originating from modified SMCs of the media layer. 2) Papillary zone, generally with myriad papillae, formed by ECs of intraparietal microvessel networks encircling vein wall components (parietal papillae). 3) Organizing thrombotic zone from microvascular networks of invaginated vein wall zone. 4) Unorganized thrombotic zone partially covered by ECs, also originating from vein intimal endothelium and arranged in a monolayer or encircling thrombotic fibrin (thrombotic papillae). In conclusion, the capacity of vein intimal ECs and those originating from them (in newlyformed microvessels in the vein itself and covering the unorganized thrombi) to encircle vein wall components or fibrin, and to form papillae (ECs form the cover and encircled components the core) supports a piecemeal mode of angiogenesis as a pathogenic basis of IPEH. This mechanism encompasses the two histogenetic hypotheses outlined above.
Open Access
Intussusceptive angiogenesis facilitated by microthrombosis has an important example in angiolipoma. An ultrastructural and immunohistochemical study
(Universidad de Murcia, Departamento de Biologia Celular e Histiologia, 2023) Díaz Flores, Lucio; Gutiérrez, Ricardo; Pino García, Maria; González Gómez, Miriam; Díaz Flores Jr, Lucio; Carrasco, Jose Luis; Álvarez Argüelles, Hugo; Madrid Cuevas, Juan Francisco
The microvasculature of angiolipoma frequently presents thrombi. Our objectives are to assess whether intussusceptive angiogenesis (IA) participates in vasculature formation in non-infiltrating angiolipoma and, if so, to explore how thrombi are involved in the IA process. For this purpose, we studied angiolipoma specimens (n: 52), using immunohistochemistry, and confocal and electron microscopy. The results showed the presence of folds and pillars, hallmarks of IA, dividing the vessel lumen. Folds showed a cover formed by reoriented endothelial cells from the vessel wall, or from newly formed folds, and a core initially formed by thrombus fragments (clot components as transitional core), which was replaced by extracellular matrix and invaginating pericytes establishing numerous peg-andsocket junctions with endothelial cells (mature core). A condensed plasmatic electron-dense material surrounded and connected folds and pillars with each other and with the vascular wall, which suggests a clot role in fold/pillar arrangement. In conclusion, we contribute to IA participation in capillary network formation in angiolipoma and the immunohistochemical and ultrastructural events by which microthrombosis facilitates IA. Therefore, in addition to the histogenesis of angiolipoma, we provide an easily obtainable substrate for future studies on clot component action in IA, of clinical and therapeutic interest
Open Access
Ischemic stroke activates the VE-cadherin promoter and increases VE-cadherin expression in adult mice
(Universidad de Murcia. Departamento de Biología Celular e Histología, 2018) Nakano Doi, Akiko; Sakuma, Rika; Matsuyama, Tomoiro; Nakagomi, Takayuki
Endothelial cells (ECs) are a key component of the blood-brain barrier (BBB). Healthy ECs in the BBB form inter-endothelial junctions, including adherens junctions (AJs). Under pathological conditions, such as after ischemic stroke, the BBB may be functionally compromised. However, gene and protein expression patterns involving endothelial AJs have not been well studied. Because expression levels of endothelial AJs are considered to be related to BBB functionality, we investigated the expression pattern of a representative endothelial AJ marker, VE-cadherin, in healthy and diseased mice. We first examined the expression of VE-cadherin in developing mouse brains. In addition, using a mouse model of cerebral infarction, we investigated the expression pattern of VE-cadherin in pathologic brains. Furthermore, using the Cre-LoxP system, we established a strain of mice expressing yellow fluorescent protein (YFP) under the control of the VE-cadherin promoter and investigated the expression pattern of YFP-expressing ECs in developing and pathologic murine brains. VE-cadherin protein and YFP expression driven by the VE-cadherin promoter both showed that VE-cadherin expression was weak during embryonic stages, followed by a steady increase postnatally, which then decreased during adulthood. However, following ischemic stroke, imunohistochemistry of VE-cadherin demonstrated an upregulation in ECs within ischemic regions, concomitant with YFP upregulation. These findings reveal that ischemic stroke activates the VE-cadherin promoter and increases VE-cadherin protein expression, which suggests that endothelial VE-cadherin is involved in the reconstruction of the BBB following ischemic stroke.
Open Access
Lack of intimal hyperplasia response in an experimental model of non-endothelial vascular wall damage
(Murcia : F. Hernández, 1992) Buján, J.; Bellón, J.M.; Golittsin, A.; Gianonatti, M.C.; Turegano, F.
The endothelial and media1 layers are generally presumed to play an important role in the appearance and development of intimal hyperplasia. We have carried out a short-, media- and long-term study of the morphological changes taking place in the comrnon iliac artery of rats after surgical removal of the adventitial layer. Our aim has been to assess the likely role played by this layer in the development of intimal hyperplasia. Our results show recurrent periods of cellular desquamation and almost complete absence of hyperplastic response during the first two months. After three months three is a slow process of endothelialization which is completed by the 6th month and persists one year after adventitial resection. Thus, adventitial resection seems to cause instability at the subendothelial bed level, not allowing the junction and embedding of endothelial cells nor the development of intimal hyperplasia. This lack of hyperplasia might also result from the fact that the endothelial desquamation process does not involve cellular rupture, which would prevent mitogenic-factor release. After morphological repair of the endothelium, a slow morphofunctional recovery of the artery takes place
Open Access
Membrane trafficking and exocytosis are upregulated in port wine stain blood vessels
(Universidad de Murcia. Departamento de Biología Celular e Histología, 2019) Yin, Rong; Rice, Shawn J.; Wang, Jinwei; Gao, Lin; Tsai, Joseph; Anvari, Radean T.; Zhou, Fang; Liu, Xin; Wang, Gang; Tang, Yuxin; Mihm Jr, Martin C.; Belani, Chandra P.; Chen, Dong Bao; Nelson, J. Stuart; Tan, Wenbin
Introduction. Port wine stain (PWS) is characterized as a progressive dilatation of immature venule-like vasculatures which result from differentiation-impaired endothelial cells. In this study, we aimed to identify the major biological pathways accounting for the pathogenesis of PWS. Methods. Sequential windowed acquisition of all theoretical fragment ion mass spectra (SWATH-MS) was used to identify differentially expressed proteins in PWS lesions, followed by confirmative studies with immunohistochemistry, immunoblot and transmission electron microscopy (TEM). Results. 107 out of 299 identified proteins showed differential expressions in PWS lesions as compared to normal skin, mainly involving the functions of biosynthesis, membrane trafficking, cytoskeleton and cell adhesion/migration. The confirmative studies showed that expressions of membrane trafficking/ exocytosis related proteins such as VAT1, IQGAP1, HSC70, clathrin, perlecan, spectrin α1 and GDIR1 were significantly increased in PWS blood vessels as compared to normal ones. Furthermore, TEM studies showed there is a significant upregulation of extracellular vesicle exocytosis from PWS blood vessels as compared to control. Conclusions. The biological process of membrane trafficking and exocytosis is enhanced in PWS blood vessels. Our results imply that the extracellular vesicles released by lesional endothelial cells may act as potential intercellular signaling mediators to contribute to the pathogenesis of PWS.
Open Access
Metalloproteinase expression by control and telomerase immortalized human endometrial endothelial cells
(Murcia : F. Hernández, 2005) Krikun, G.; Mor, G.; Huang, J.; Schatz, F.; Lockwood, C.J.
Vascular endothelial cells play a critical role in the maintenance of endometrial homeostasis. Indeed many pathological conditions causing abnormal endometrial bleeding including progestin only contraception, hormone replacement therapy, endometrial polyps, myomas, hyperplasia and cancer are associated with aberrant angiogenesis. Critical to the process of angiogenesis is the breakdown of the surrounding tissues by matrix metalloproteases (MMPs). In addition to the cells surrounding the endometrial endothelial cells, the endothelial cells themselves produce their own panel of MMPs. We now characterize the specific MMPs that are expressed by endothelial cells derived from human endometrium. These include MMP-1, MMP-2 and MMP-10 but not MMP-3. In addition, in order to successfully carry out consistent, homogeneous and sufficient numbers of studies we investigated the in vitro expression of the MMPs with both freshly isolated, early passaged endometrial endothelial cells (HEECs) as well as with newly telomerase immortalized HEECs (T-HEECs). The latter were karyotypically normal and expressed classic endothelial cell endpoints such as tubulogenesis on matrigel and expression of the endothelial cell markers CD-31 (PECAM), von Willebrand’s factor, and the Tie-2 receptors. The levels of MMP expression as well as that of the metalloprotease inhibitors TIMP-1 and TIMP-2 were similar in parent and immortalized endothelial cells.
Open Access
Modulatory role of IL10 in endothelial cell damage and platelet adhesion
(Murcia : F. Hernández, 2003) Gimeno, M.J.; Pascual, G.; García-Honduvilla, N.; Prieto, A.; Alvarez de Mon, M.; Bellón, J.M.; Buján, J.
This study explores the possibility of a regulatory role for cytokine IL-10 in platelet aggregation as an active vascular repair mechanism. Endothelial cells from human umbilical cord vein were cultured in the presence of different IL-10 concentrations (0-100 ng/ml). Platelet-rich plasma was then added to these cultures and allowed to act for 30 minutes. To rule out blood plasma involvement, washed platelets were also incubated with IL-10 (0-100 ng/ml). Changes in endothelial cell morphology were observed depending on the IL-10 concentration used; apoptotic cells appearing at the highest IL-10 concentration. Greatest platelet adhesion was noted at the highest IL-10 concentration. It was concluded that, in this in vitro model, low IL-10 levels do not affect cell viability or the pattern of platelet adhesion, but at high doses, this cytokine induces cell death and enhances platelet deposition.
Open Access
Morphofunctional basis of the different types of angiogenesis and formation of postnatal angiogenesis-related secondary structures
(Universidad de Murcia. Departamento de Biología Celular e Histología, 2017) Díaz Flores, L.; Gutierrez, R.; García Suárez, M.P.; Sáez, F.J.; Gutiérrez, E.; Valladares, F.; Carrascosa, J.L.; Díaz Flores Jr, L.; Madrid Cuevas, Juan Francisco
We review the morpho-functional basis of the different types of angiogenesis and report our observations, including the formation of angiogenesisrelated secondary structures. First of all, we consider the following issues: a) conceptual differences between angiogenesis and vasculogenesis, b) incidence of angiogenesis in pre- and postnatal life, c) regions of vascular tree with angiogenic capacity, d) cells (endothelial cells, pericytes, CD34+ adventitial stromal cells of the microvasculature and inflammatory cells) and extracellular matrix components involved in angiogenesis, e) events associated with angiogenesis, f) different types of angiogenesis, including sprouting and intussusceptive angiogenesis, and other angiogenic or vascularization forms arising from endothelial precursor cells (postnatal vasculogenesis), vasculogenesis mimicry, vessel co-option and piecemeal angiogenesis. Subsequently, we consider the specific morphofunctional characteristics of each type of angiogenesis. In sprouting angiogenesis, we grouped the events in three phases: a) activation phase, which includes vasodilation and increased permeability, EC, pericyte and CD34+ adventitial stromal cell activation, and recruitment and activation of inflammatory cells, b)sprouting phase, encompassing EC migration (concept and characteristics of endothelial tip cells, tip cell selection, lateral inhibition, localized filopodia formation, basal lamina degradation and extracellular changes facilitating EC migration), EC proliferation (concept of endothelial stalk cells), pericyte mobilization, proliferation, recruitment and changes in CD34+ adventitial stromal cells and inflammatory cells, tubulogenesis, formation of a new basal lamina, and vascular anastomosis with capillary loop formation, and c) vascular remodelling and stabilization phase (concept of phalanx cells). Subsequently, the concept, incidence, events and mechanisms are considered in the other forms of angiogenesis. Finally, we contribute the formation of postnatal angiogenesis-related secondary structures: a) intravascular structures through piecemeal angiogenesis, including intravascular papillae in vessel tumours and pseudotumours (intravascular papillary endothelial hyperplasia, vascular transformation of the sinus in lymph nodes, papillary intralymphatic angioendothelioma or Dabska tumour, retiform hemangioendothelioma, hemangiosarcoma and lymphangiosarcoma), vascular septa in hemorrhoidal veins and intravascular projections in some tumours; b) arterial intimal thickening; c) intravascular tumours and pseudotumours (e.g. intravenous pyogenic granulomas and intravascular myopericytoma); d) vascular glomeruloid proliferations; and e) pseudopalisading necrosis in glioblastoma multiform.
Open Access
Myriad pillars formed by intussusceptive angiogenesis as the basis of intravascular papillary endothelial hyperplasia (IPEH). IPEH is intussusceptive angiogenesis made a lesion
(Universidad de Murcia, Departamento de Biologia Celular e Histiologia, 2021) Díaz-Flores, Lucio; Gutiérrez, Ricardo; González-Gómez, Miriam; Pino García, Mª; Carrasco, José Luis; Díaz-Flores, Lucio; Madrid Cuevas, Juan Francisco
. Intussusceptive angiogenesis (IA) is the process by which pre-existing blood vessels split, expand and remodel through intravascular pillar formation. In previous works, we studied the morphologic characteristics of intravascular papillary endothelial hyperplasia (IPEH) and suggested the participation of IA in the histogenesis of the lesion. Our current goal is to demonstrate that myriad papillae in IPEH are in fact myriad pillars, the hallmarks of IA. For this purpose, specimens of 14 cases of IPEH were used for conventional histologic techniques, immunohistochemistry and immunofluorescence in confocal microscopy. The studies showed the following pillar characteristics: a) structural composition by an endothelial cell (EC) cover and a connective core, b) characteristic pillar image and its appearance and disappearance in whole-mounted and series of individual views in confocal microscopy (requirements for pillar identification), c) arrangement in masses, alignments and meshes, and d) formation from vein intimal ECs, which extend and originate loops that encircle vein wall components (interstitial tissue structures: ITSs) and fibrin. The encircling ECs form the pillar cover and the encircled ITSs or fibrin form the initial core. Intraluminal endothelial bridges also originate from the vessel wall and from the pillars (nascent and thin pillars). In conclusion, the formation of myriad pillars, predominantly in veins, is the basis of IPEH. This lesion may therefore be considered an excessive expression of IA: IA becomes a lesion.
Open Access
Protective role of the complement regulatory protein human CD-55 in cardiac xenograft: a descriptive study and a revision of the literature
(Murcia : F. Hernández, 2002) Cappello, F.; Bellafiore, M.; Palma, A.; Marcianò, V.; Licata, L.; Cannino, G.; Gentile, C.; Zummo, G.; Farina, F.; Bucchieri, F.
The limited and inadequate availability of organs from human donors has resulted in the utilisation of xenografts as an alternative tool. Nevertheless, hyperacute rejection (HAR) following xenograft determines the loss of the transplanted organ. The “primum movens” is the activation of the complement pathway mediated by the binding of natural xenogenic antibodies to the endothelium of the graft, followed by the lysis of the endothelial cells with subsequent oedema, thrombosis and necrosis of the transplanted organ. In this work we describe morphological and biomolecular observations of isolated human-decay accelerating factor (h-DAF, CD55) transgenic pig hearts, after perfusion for four hours with human blood. H-DAF is a membrane glycoprotein inhibiting the complement activation in humans. We describe considerably reduced damages in transgenic hearts, compared to controls. The cardiac function resulted preserved. Our data are in agreement with what was already shown by other groups using different experimental models. In conclusion, we encourage the use of new sources of transgenic animals, pointing out the importance of morphological analysis in evaluation of xenograft.
Open Access
Regeneration of heart muscle tissue: quantification of chimeric cardiomyocytes and endothelial cells following transplantation
(Murcia : F. Hernández, 2004) Thiele, J.; Varus, E.; Wickenhauser, C.; Kvasnicka, H.M.; Metz, K.A.; Beelen, D.W.
Persuasive evidence has been recently provided that adult bone marrow (BM) cells exert greater plasticity than previously assumed. This review is focused on the quantification of mixed chimerism (mCh) in the hearts (cardiomyocytes and endothelial cells) of patients after orthotopic heart to heart transplantation (HHT) in comparison to full (unmanipulated) allogeneic BM and peripheral blood stem cell (PBSC) transplants. Following a sexmismatched transplantation constellation heart muscle tissue obtained at autopsy was examined. Evaluation of mCh was most often performed by immunophenotyping combined with fluorescence in-situ hybridization (FISH) applying x- and y-chromosome-specific DNA probes. When comparing our data with the results of former studies that were regularly based on the detection of the y-chromosome alone, the quantity of chimeric cardiomyocytes after HHT ranged from 0% to 9%. On the other hand, after full BM transplantats (chimeric) cardiomyocytes of donor-type origin appeared at an incidence between 0.23% to 6.4%. These disturbing inconsistencies were assumed to be related to methodology: the restriction to the y-chromosome, disregard of the plane of section (detection sensitivity ranging between 35% and 67%) and state of tissue preservation (cadaver hearts). Therefore, when strictly applying dual color FISH and limiting the recognition of chimeric cardiomyocytes and endothelial cells to the presence of two distinctive signals detection sensitivity was significantly enhanced. Contrasting a total congruence with the genotyping in control specimens of normal cadaver hearts, a striking disparity in the extent of mCh was found depending on the different modes of transplantation. After allografting with PBSC a considerably low incidence (1.6%) of chimeric cardiomyocytes was determined contrasting with 5.3% of donor-derived cells after full BM transplants. Following HHT host-type endothelial cells (16.2 %) of the intramural and subepicardial vessel walls were more often encountered than following BM and PBSC allografting. These findings are in keeping with the assumption of a sprouting and migration of vascular structures into the donor heart from the site of surgical aligment and injury between retained host and donor atrial walls. When considering the other methods of transplantation (BM, PBSC) the data on chimeric endothelial cells support the hypothesis of a common hemangioblast. Concerning the cardiomyocytes it seems most reasonable to assume that primitive mesenchymal stem cells of the BM play a pivotal role in the development of mCh. This phenomenon is more extensively expressed than previously expected and may be related to an enforced repair of the damaged myocardium during the post-transplant period as the sequel of myeloablative (cardiotoxic) conditioning .
Open Access
Seeding of expanded polytetrafluoroethylene (ePTFE) vascular grafts. A morphological study of porcine endothelial and fibroblast cells
(Murcia : F. Hernández, 1992) Buján, J.; Bellón, J.M.; Navlet, J.G.; Honduvilla, N.; Hernando, A.; Turegano, F.
The need to improve clinical results with small and medium calibre grafts has led to extensive research on cell seeding of prosthetic materials. Numerous problems remain regarding identification, seeding, adhesion and survival of the cells attached. We have studied the behaviour of seedings of endothelial and fibroblast cells on ePTFE grafts. Scanning electron microscopy allows us to observe the morphological characteristics and their interaction with the biopolymers. It has been possible to differentiate both cellular types by their characteristics and interactions with the ePTFE. At the same time, from this ~ i vni t ro~st udy it can be concluded that the time needed to obtain a stable and confluent monolayer on ePTFE pretreated with fibronectin is between 18 hours to 4 days for endothelial cells, and 24 hours for fibroblasts. These would be the optimal time periods for ain vivo. grafting of the seeded prostheses.
Open Access
Sphingosine 1-phosphate and its regulatory role in vascular endothelial cells
(Universidad de Murcia, Departamento de Biologia Celular e Histiologia, 2022) Qiu, Yan; Shen, Junyi; Jiang, Wenli; Yang, Yi; Liu, Xiaoheng; Zeng, Ye
Sphingosine 1-phosphate (S1P) is a bioactive metabolite of sphingomyelin. S1P activates a series of signaling cascades by acting on its receptors S1PR1-3 on endothelial cells (ECs), which plays an important role in endothelial barrier maintenance, anti-inflammation, antioxidant and angiogenesis, and thus is considered as a potential therapeutic biomarker for ischemic stroke, sepsis, idiopathic pulmonary fibrosis, cancers, type 2 diabetes and cardiovascular diseases. We presently review the levels of S1P in those vascular and vascularrelated diseases. Plasma S1P levels were reduced in various inflammation-related diseases such as atherosclerosis and sepsis, but were increased in other diseases including type 2 diabetes, neurodegeneration, cerebrovascular damages such as acute ischemic stroke, Alzheimer's disease, vascular dementia, angina, heart failure, idiopathic pulmonary fibrosis, communityacquired pneumonia, and hepatocellular carcinoma. Then, we highlighted the molecular mechanism by which S1P regulated EC biology including vascular development and angiogenesis, inflammation, permeability, and production of reactive oxygen species (ROS), nitric oxide (NO) and hydrogen sulfide (H2S), which might provide new ways for exploring the pathogenesis and implementing individualized therapy strategies for those diseases
Open Access
Spontaneous intracerebral hemorrhage as presentation of atypical central neurocytoma: the role of angiogenesis through the characterization of tumor endothelial cells
(Universidad de Murcia. Departamento de Biología Celular e Histología, 2018) Marfia, Giovanni; Pirola, Elena; Navone, Stefania Elena; Beretta, Matteo; Guarnaccia, Laura; Trombetta, Elena; Franzini, Andrea; Rampini, Paolo; Campanella, Rolando
A 36-year-old white man presented with sudden-onset headache and rapid deterioration of consciousness. Computer tomography revealed a right capsular intra-parenchimal hemorrhage with an intraventricular component; therefore, emergency surgery was performed. Once the hematoma was evacuated, the cause of the hemorrhage was identified as a tumor mass and it was resected. Histopathological and immunohistochemical examinations of the surgical specimen disclosed a diagnosis of atypical central neurocytoma. By using a protocol recently set up in our laboratory, we succeeded in isolating and propagating, for the first time, human endothelial cells from central neurocytoma (CN-ECs). Different analyses revealed that isolated CNECs consist of a pure endothelial cell population, with the expression of endothelial markers (CD31, CD309/VEGFR2, CD105, eNOS) and with angiogenic properties, such as the uptake of LDL. Moreover, CNECs spontaneously organize in a vascular-like structure. The goal of this case report is to stress the need for further studies focused on understanding the causes of the onset of an intra-parenchimal hemorrhage in the presence of an atypical central neurocytoma in order to tailor treatments to each single patient and achieve the best clinical outcome.