TNF-α promotes the quantity and ICAM-1 expression of endothelial microparticles / 医用生物力学

Objective To study the role of cyclic strain-modulated tumor necrosis factor-α (TNF-α) played in the quantity and intercellular cell adhesion molecule-1(ICAM-1) expression of endothelial microparticles (EMPs). Methods The endothelial cells (ECs) primarily cultured from rat aorta were applied with 5% cyclic strain (to simulate normal physiological condition) and 18% cyclic strain (to simulate hyper-tension condition), respectively, by using FX-4000T cyclic stain loading system for 24 hours at the loading frequency of 1.25 Hz. The mRNA expression of TNF-α under different amplitudes of cyclic strain was determined by real time-PCR. The TNF-α was then used to stimulate the ECs from rat aorta, and the supernatants were collected and ultracentrifuged to get endothelial microparticles (EMPs), which were then identified by lipophilic styryl membrane staining and transmission electron microscope for morphological identification. The quantities of Annexin V positive EMPs under TNF-α stimulation were counted by flow cytometer and ICAM-1 expression on EMPs was detected as well. Results Compared with the 5% normal cyclic strain, under 18% high cyclic strain condition,the mRNA expression of TNF-α in ECs increased significantly. TNF-α could then significantly up-regulate the production of Annexin V positive EMPs and promote the expression of ICAM-1 on EMPs. Conclusions The over-expression of TNF-α in ECs under high cyclic strain might mediate the high production of EMPs and over-expression of ICAM-1 on EMPs. The research findings will provide new experiment evidence for further studying the role of EPCs in the mechanobiological mechanism of vascular remodeling.

Immunohistochemical Study of Immune Cells, with a Special Emphasis on Macrophage Subpopulations in the Rat Thymus after Cyclophosphamide Treatment / 대한해부학회지

This study was undertaken to investigate the in vivo effects of cyclophosphamide (CY) on immune cells, with a special emphasis on macrophage subpopulations in the thymus of rats. After a single dose of CY (150 mg/kg) was administered to Sprague-Dawley rats by intraperitoneal injection, the rats were sacrificed at days 1, 3, 7, 14 and 28. The immunohistochemical characterization of the tissues were carried out using various monoclonal antibodies in cryostat-cut sections. CD4(+/-) and CD8(+/-) T cells were greatly decreased in number after CY treatment. However, macrophages, including the ED1(+/-) ED2(+/-) and ED3(+/-) macrophages exhibited signs of cellular activation such as an increase in number and size of cell, and an upregulation of the ED1, ED2 and ED3 reactive surface molecule expression. Contrarily, CY elicited a decrease in number of thymic dendritic cells (DCs). CY induced a conspicuous upregulation of ICAM-1 expression in the thymic cortex. Most of these features began to detectable from the first day and reached the maximun on the third and seventh days, but two weeks after CY administration, these phenomena began to disap. In conclusion, the results of the present study shed more light on the effects of CY on various subpopulations of macrophages and other types of immune cells and on ICAM-1 expression in the rat thymus.

Immunohistochemical Study of Immune Cells, with a Special Emphasis on Macrophage Subpopulations in the Rat Spleen after Cyclophosphamide Treatment / 대한해부학회지

This study was undertaken to investigate the in vivo effects of cyclophosphamide (CY) on subpopulations of macrophages and other types of immune cells including dendritic cells (DCs) as well as on ICAM-1 expression in the spleen of rats. After a single dose of CY (150 mg/kg) was administered to Sprague-Dawley rats by intraperitoneal injection, the rats were sacrificed at 1, 3, 7, 14 and 28 days. The immunocytochemical characterization of the tissues were carried out using the monoclonal antibodies W3/25, OX8, HIS24, 8A2, OX6, OX62, ED1, ED2, ED3, and TLD-4C9 for analysis of macrophage subpopulations, DC(s), CD4(+) and CD8(+) T cells, B cells and ICAM-1 expression in cryostat-cut sections. CY exhibited a profound immunosuppressive effect on CD4(+) and CD8(+) T cells as well as B cells as was expected. However, it was found that CY induced an increase in number of certain subpopulations of macrophages, including ED1(+), ED2(+) and ED3(+) macrophages. Contrarily, CY elicited a decrease in number of DCs. CY induced a conspi-cuous upregulation of ICAM-1 on certain populations of leukocytes. This increased expression of ICAM-1 after CY treatment appears to be related with the recruitment of certain populations of leukocytes. Most of these features began to appear from the first day and reached the maximun on the third and especially, the seventh day, but two weeks after CY administration, these phenomena declined. In conclusion, the present study provided a new insight into the differential effects of CY on various populations and subpopulations of immune cells in the rat spleen.