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Endothelial Morphology (endothelial + morphology)

Distribution by Scientific Domains

Medical Sciences	75%

Selected Abstracts

Astrocyte and endothelial cell expression of ADAM 17 (TACE) in adult human CNS

GLIA, Issue 4 2001
Diane R. Goddard
Abstract ADAM 17, also known as TACE, is an important sheddase for a number of proteins, including tumor necrosis factor-, (TNF-,), transforming growth factor-, (TGF-,), L-selectin, p75, and p55 TNF receptors, and interleukin-1 receptor II (IL-1RII). The presence of ADAM 17 mRNA in adult mouse and rat CNS was recently reported (Karkkainen et al. Mol Cell Neurosci 15:547,560, 2000). However, the cellular origin of ADAM 17 remains unknown. In this study, we have used an anti-ADAM 17 antibody in an immunohistochemical study of its distribution in human adult CNS tissue. Cells with astrocytic and endothelial morphology were ADAM 17-positive. This finding was further confirmed using double immunofluorescence with antibodies against GFAP and von Willebrand factor, which label astrocytes and endothelial cells, respectively. This study demonstrates that ADAM 17 is expressed by astrocytes and endothelial cells in normal brain tissue and may have a role in normal brain function. GLIA 34:267,271, 2001. © 2001 Wiley-Liss, Inc. [source]

Thrombin and PAR-1 stimulate differentiation of bone marrow-derived endothelial progenitor cells

JOURNAL OF THROMBOSIS AND HAEMOSTASIS, Issue 3 2006
S. T. TARZAMI
Summary., Endothelial progenitor cells (EPCs) from the bone marrow play an important role in vascular response to injury and ischemia. The mediators involved in the mobilization, recruitment, proliferation and differentiation of EPCs are not fully understood. In this study, the role of coagulation factor thrombin and protease-activated receptor-1 (PAR-1) on bone marrow-derived cell proliferation and differentiation was investigated. Bone marrow cells (BMCs) were isolated from C57/BL6 mice and plated on fibronectin-coated flasks. Cell characteristics, proliferation and the expression of endothelial cell markers were determined using immunohistochemistry, thymidine uptake and fluorescence activated-cell sorting (FACS), respectively. The results show that thrombin stimulated enrichment of bone marrow cells with endothelial morphology, exhibiting acetylated-low-density lipoprotein (LDL) uptake and isolectin staining. Thrombin or PAR-1-activating peptide produced a 2- to 3-fold increase in the total number of cells as well as an increase in vascular endothelial (VE)-cadherin-positive cells. Thrombin treatment of VE-cadherin-negative cells prepared after cell sorting resulted in the generation of 3- to 4-fold higher VE-cadherin-positive cells than the untreated cultures. Increase in VE-cadherin-positive cells was inhibited by hirudin and efegatran. These results provide first evidence for a novel activity of thrombin and PAR-1 on bone marrow progenitor cell proliferation and EPC differentiation, and suggest their potential role in vascular regeneration and recanalization of thrombus. [source]

Effects of Cyclic Stretch Waveform on Endothelial Cell Morphology Using Fractal Analysis

ARTIFICIAL ORGANS, Issue 6 2010
Nooshin Haghighipour
Abstract Endothelial cells are remodeled when subjected to cyclic loading. Previous in vitro studies have indicated that frequency, strain amplitude, and duration are determinants of endothelial cell morphology, when cells are subjected to cyclic strain. In addition to those parameters, the current study investigated the effects of strain waveform on morphology of cultured endothelial cells quantified by fractal and topological analyses. Cultured endothelial cells were subjected to cyclic stretch by a designed device, and cellular images before and after tests were obtained. Fractal and topological parameters were calculated by development of an image-processing code. Tests were performed for different load waveforms. Results indicated cellular alignment by application of cyclic stretch. By alteration of load waveform, statistically significant differences between cell morphology of test groups were observed. Such differences are more prominent when load cycles are elevated. The endothelial cell remodeling was optimized when the applied cyclic load waveform was similar to blood pressure waveform. Effects of load waveform on cell morphology are influenced by alterations in load amplitude and frequency. It is concluded that load waveform is a determinant of endothelial morphology in addition to amplitude and frequency, and such effect is elevated by increase of load cycles. Due to high correlation between fractal and topological analyses, it is recommended that fractal analysis can be used as a proper method for evaluation of alteration in cell morphology and tissue structure caused by application of external stimuli such as mechanical loading. [source]

Influence of temperature on corneas stored in culture medium.

ACTA OPHTHALMOLOGICA, Issue 1 2003
A comparative study using functional, morphological methods
Abstract. Purpose:, To investigate the influence of storage temperature on corneal swelling and on endothelial morphology in cultured corneas. Material and methods:, Forty-eight rabbit corneas were separated into four groups of 12. The corneas were stored in culture medium at 37 ° (group 37), 34 ° (group 34), 31 ° (group 31) and 23 ° (room temperature) (group 23), respectively. All the corneas were monitored by weight recordings on days 0, 1, 2, 3, 4 and 7. On day 7, corneas were prepared for scanning electron microscopy and endothelial cell counts were performed. Results:, Lowering the temperature of the culture medium resulted in less swelling. Both temperature and storage time had significant effects on corneal swelling (p < 0.001). On day 7, the observed mean weight increase was 131.2%, 143.0%, 172.5% and 199.7% in groups 23, 31, 34 and 37, respectively. The estimated mean daily weight increase for the corneas were 2.6%, 4.0%, 9.1% and 16.0% in groups 23, 31, 34 and 37, respectively. Scanning electron microscopy showed an intact endothelial layer in all groups after 7 days and there were no statistically significant differences in endothelial counts between groups 23, 31 and 34. In group 37, the cell borders were difficult to distinguish after 7 days and no meaningful count could be performed. Conclusions:, The swelling rate of cultured corneas is significantly less at 23 ° and 31 ° than it is at 34 ° and 37 ° during the first week. This is most likely the result of a greatly increased barrier effect at lower temperatures. Whereas weight recording revealed profound differences between the groups, scanning electron microscopy and endothelial cell counting did not. The results support the hypothesis that storage at 37 ° is not optimal in culturing corneas. Lowering the temperature below body temperature, and even lower than 31 °, results in less corneal swelling. [source]