Study on Endothelial Cell Adhesion and Retention on Tissue Engineered Vascular Grafts

1 IntroductionThe poor adhesion and retention of living endothelial cells (ECs) on the vascular grafts has been remaining as a challenging problem. When implanted into a human body, the performance of a biomaterials on which cells are seeded is greatly af…     

Effect of Thalidomide on the Expression of TNF-α m-RNA and Synthesis of TNF-α in Cells from Leprosy Patients with Reversal Reaction

Hypersensitivity reactions called reversal reaction (RR) and erythema nodosum leprosum (ENL) occur in leprosy. They are characterized by an increase in tumor necrosis factor-alpha (TNF-α). Thalidomide is an effective treatment for ENL but not RR. Its effectiveness in ENL is attributed to inhibition of TNF-α, and this does not explain its failure to treat RR. We assessed thalidomide's effect on TNF-α in RR. Mononuclear cells from RR and non-RR patients and healthy individuals were treated with thalidomide and M.leprae (AFB), a cytosol fraction of M. leprae or Dharmendra lepromin. Thalidomide suppressed TNF-α, but when some RR patients' cells were stimulated with AFB, it enhanced TNF-α.     

Research of the Effect of the Shear Stress on Endothelial Cells

1 IntroductionCellular mechanism is one of the foundations of regenerating medicine and tissue engineering, which is also an advanced subject in cell mechanism in recent years~([1]). The form and function of a cell, and the growing, reproducing and death, even canceration are related to the characteristics of cell mechanism. While the research of the shear stress on endothelial cells is an important field in cell mechanism. The main bio-functions of endothelial cells are as follows: anti-cruor…     

Potential Use of Polyelectrolyte Multilayer thin Films in Vascular Tissue Engineering:Evaluation of the Viability and Adhesion of Endothelial Cells

1 IntroductionA method in vascular tissue engineering to obtain hemocompatible synthetic prosthesis consists to cover the luminal surface by a monolayer of endothelial cells (ECs). Nevertheless, the surface of current prosthesis does not favour the development of an ECs monolayer. Recently, a new versatile method of self-assembled architectures based on the alternate adsorption of polycations and polyanions has been developed to lead to the build-up of multilayered polyelectrolyte films (MP…     

Effect of Adhesion Molecule P-selectin and Dendritic Cells on Tubulointerstitial Lesions in IgA Nephropathy

It is well appreciated that tubulointerstitial lesions (TILs)associated with renal insufficiency are frequently observedin IgA nephropathy. TILs may be induced by cell mediat ed immune responses and are closely related to the progno sis of the disease […     

Effect of Cell–Cell Interactions on the Observable Strength of Adhesion of Sheets of Cells

Previous research in cellular adhesion has focused primarily on studying isolated cells under conditions where cells do not interact with each other. However, in vivo cells form sheets where both cell–substratum and cell–cell interactions contribute to the overall adhesive behavior. Our understanding of how cell–cell and cell–substratum interactions affect the overall process of cell adhesion in these situations is limited. To address this problem, we developed a systematic approach to evaluate how cell–cell and cell–substratum interactions affect the critical shear stress for detachment for semiconfluent and confluent sheets of cells. Our studies were based on subjecting cultures of adherent cells to a defined hydrodynamic flow in a radial-flow chamber with a gap height of 140 m. Using phase-contrast microscope imaging and analysis we measured shear-dependent patterns of detachment as a function of the extent of cell confluency. Our results show that the critical shear stress for detachment is maximum at intermediate extents of confluency of 10%–40%. These results have important implications for sodding vascular grafts and tissue engineering. © 1999 Biomedical Engineering Society. PAC99: 8718-h, 8719Rr     

Distinct Deleterious Effects of Cyclosporine and Tacrolimus and Combined Tacrolimus–Sirolimus on Endothelial Cells: Protective Effect of Defibrotide

Endothelial dysfunction seems to be a key factor in the development of several complications observed early after hematopoietic stem cell transplantation (HSCT). The conditioning regimen and many other factors associated with the procedure are responsible for this endothelial damage. The effects of immunosuppressive agents on endothelial function have not been explored in detail. We evaluated the effects of 3 drugs commonly used in HSCT: 2 calcineurin inhibitors, cyclosporine A (CSA) and tacrolimus (TAC), and an inhibitor of mTOR, sirolimus (SIR). We also evaluated the effect of the combination of TAC and SIR (TAC+SIR), which is used increasingly in clinical practice. Microvascular endothelial cells (HMEC-1) were exposed to these drugs to evaluate changes in (1) intercellular adhesion molecule (ICAM)-1 expression on the cell surface, assessed by immunofluorescence labeling and expressed as the mean gray value (MGV); (2) reactivity of the extracellular matrix (ECM) toward platelets, upon exposure of the ECM to circulating blood; and (3) whole-blood clot formation, assessed by thromboelastometry. Studies were conducted in the absence and presence of defibrotide (DF) to assess its possible protective effect. The exposure of HMEC-1 to CSA and TAC+SIR significantly increased the expression of ICAM-1 (157.5 ± 11.6 and 153.4 ± 9.5 MGV, respectively, versus 105.7 ± 6.5 MGV in controls [both P < .05]). TAC applied alone increased ICAM-1 slightly (120.3 ± 8.2 MGV), and SIR had no effect (108.9 ± 7.4 MGV). ECM reactivity increased significantly only in response to CSA (surface covered by platelets of 41.2% ± 5.4% versus 30.1% ± 2.0%, P < .05). DF attenuated all these changes. No significant changes in the viscoelastic properties of clot formation were observed in any condition with blood samples incubated in vitro. In conclusion, CSA and TAC+SIR had a proinflammatory effect, but only CSA exhibited an additional prothrombotic effect. Interestingly, DF exerted clear protective anti-inflammatory and antithrombotic effects on the endothelium.     

Effect of IL-1β and TNF-α polymorphisms on the prognosis and survival of gastric cancer patients

So far, a number of association studies have focused on the effect of polymorphisms in IL-1β and TNF-α genes on the susceptibility to gastric cancer (GC). Here, we evaluate the possible association between common polymorphisms in the IL-1β and TNF-α genes with various clinicopathological characteristics, including overall survival of GC patients. Restriction fragment length polymorphism analysis was performed for IL-1β-31(T?>?C) and IL-1β-511(C?>?T) and TNF-α-857 (C?>?T) polymorphisms in 130 GC patients. IL-1β-31CC and IL-1β-511TT genotypes held a significantly lower risk of lymphatic invasion (IL-1β-31CC vs. others: adjusted OR?=?0.39, 95% CI?=?0.15-0.96, P?=?0.04, IL-1β-511TT vs. others: adjusted OR?=?0.23, 95% CI?=?0.08-0.67, P?=?0.007). The IL-1β-31CC and IL-1β-511TT genotypes were weakly associated with reduced risk of venous invasion (IL-1β-31CC vs. others: adjusted OR?=?0.35, 95% CI?=?0.12-1.05, P?=?0.06, IL-1β-511TT vs. others: adjusted OR?=?0.32, 95% CI?=?0.08-1.20, P?=?0.09). The IL-1β-511TT genotype was also weakly associated with reduced risk of lymph node metastasis (IL-1β-511TT vs. others: adjusted OR?=?0.42, 95% CI?=?0.17-1.04, P?=?0.06). When the TNF-α-857CT and TNF-α-857-TT genotypes were considered as T carrier, the patients with TNF-α-857T carrier showed significantly better overall survival than patients with CC genotype (P?=?0.011). GC patients who have both IL-1β-31 CC and IL-1β-511 TT genotypes and have at least one of protective genotypes (IL-1β-31 CC, IL-1β-511 TT, TNF-α-857 T carrier) were also associated with better prognostic factors, such as lymphatic and venous invasion better survival. IL-1β-31CC, IL-1β-511TT genotype, and TNF-α-857T carrier may have protective effect against GC progression.     

PD-L1 Regulates Inflammation in LPS-Induced Lung Epithelial Cells and Vascular Endothelial Cells by Interacting with the HIF-1α Signaling Pathway

Inflammation - Sepsis-induced lung injury was the most common cause of death in patients. This study aimed to investigate whether PD-L1 regulates the inflammation in LPS-induced lung epithelial...     

Flow-induced Expression and Phosphorylation of VASPin Endothelial Cells

1 Introduction It is well known that mechanical forces have important influence on endothelial cells, in particular, on cytoskeleton reorganization. VASP (vasodilator stimulated phosphoprotein) is a 46 KD actin associated protein. It is a member of Ena/VASP protein family and composed of EVH1, proline-rich and EVH2 domains. It is considered as an important component of the sub-cellular regions where remodelling of the actin cytoskeleton takes place, such as the front of spreading lamell…     

Synergistic Effect of Kalpaamruthaa on Antiarthritic and Antiinflammatory Properties—Its Mechanism of Action

The present study was designed to evaluate the antiinflammatory properties of Kalpaamruthaa (KA) a modified indigenous Siddha formulation constituting Semecarpus anacardium nut milk extract (SA), Emblica officinalis (EO) and honey in acute and chronic antiinflammatory studies. A dose of 150 mg/kg b.wt. of SA and KA were used for the present studies. The effect of KA was compared with standard drug diclofenac sodium. It was observed that the drug KA exhibited enhanced effect on antiinflammatory and antiarthritic properties than sole SA treatment and the collective effect of KA might be due to the combined interactions of the phytochemicals such as flavonoids, tannins and other compounds such as vitamin c present in KA.     

Cytotoxic reaction and TNF-α response of macrophages to polyurethane particles

Their unique mechanical and biological properties make polyurethanes (PUs) ideal materials for many implantable devices. However, uncertain long-term biostability in the human physiological environment limits their extensive clinical applications. Chronic inflammatory response associated with macrophage activation has been suggested as a prime factor; although the mechanism of macrophage activation in response to biomaterial surfaces and debris is still unknown. The overall objective of this work was to study the response of macrophages to PU materials in vitro by measuring cell viability and activity. The studies were carried out using phagocytozable-size PU particles from three types of commercially-available PUs: Pellethane^® 2363 80ABA (PL); Tecothane^® TT2065 (TC65); and Tecothane^® TT2085 (TC85). These polymers posess the same generic composition but differ in the length of hard and soft segments, as revealed by the FTIR and NMR studies. The results showed that PU particles affected both viability and activity of J774 macrophages. The percentage of mortality ranged from 1 to 15% with 10-100 μg ml^-1 of particles after 24 and 48 h incubation. These three types of particles induced different mortality on the macrophages. Specifically, the mortality with PL particles was 1-4% (p > 0.05), while the mortality with TC85 particles was 2-10% (p < 0.05) and 4-15% with TC65 (p < 0.05). Conversely, these particles also affected cell proliferation. Cell numbers increased by 132 and 167% after 24 and 48 h incubation, respectively, without particles, whereas the cell numbers increased only 46 and 78% with TC65, 66 and 105% with TC85, and 67 and 110% with PL in the presence of 100 μg ml^-1 of particles for the respective incubation times. PU particles also increased TNF-α release from macrophage. After having been incubated for 24 h with 100 μg ml^-1 particles of TC65, TC85, and PL, macrophages release TNF-α 7.4, 5.2, and 4.1 times more than the control. In conclusion, PU particles had cytotoxic effects on J774 macrophage at high concentrations. The order of macrophage response for three types of particles was TC65 > TC85 > PL. PU particles' effect on macrophage viability and activity depends on the concentration of particles and their chemical composition, especially on the ratio of hard to soft segments.     

Synergistic effects of tumour necrosis factor-α and interferon-γ on feline haemopoietic progenitors

Pathogenic mechanisms that underlie feline leukaemia virus subgroup-C (FeLV-C) induced erythroid aplasia are unknown. FeLV-C infection is associated with higher serum levels of interferon- (IFN-) and tumour necrosis factor- (TNF-), which may act synergistically to cause haemopoietic suppression. In the present studies, the synergistic effects of TNF- and IFN- on feline bone marrow progenitors in vitro were evaluated. Bone marrow mononuclear cells from specific-pathogen-free cats were exposed to TNF- (100 and 200 pg/ml) and IFN- (100 or 200 units/ml), alone or in combination, for 2 h before plating for clonal assays of colony forming units. Our results show that TNF- and IFN- in combination caused marked suppression of feline colony forming units-erythroid (CFU-E), burst forming units-erythroid (BFU-E), and colony forming units-fibroblasts (CFU-F), whereas colony forming units-granulocyte/macrophage (CFU-GM) were minimally affected. The same concentrations of TNF- and IFN- alone had minimal effects on CFU-E, BFU-E and CFU-F. These results suggest that TNF- and IFN- may play a significant role in regulating haemopoiesis in cats and may be involved in the pathogenesis of erythroid aplasia in cats infected with feline leukaemia virus.     

Anti-Proliferative Effect of Mycobacteria,IFN-γ and TNF-α on Primary Cultures Derived from Endometrial Stroma: Possible Relevance to Endometriosis?

PROBLEM: To assess the effects of mycobacteria and inflammatory cytokines on proliferation of endometrial stromal cells. An effect on endometrial stromal cell proliferation in vitro may suggest a similar effect on endometriotic cells in vivo. METHOD OF STUDY: Primary cultures of endometrial stromal cells were grown from female volunteers. Proliferation of cells was assessed by cell counting and incorporation of tritiated thymidine after exposure to mycobacteria or inflammatory cytokines. RESULTS: When assessed by cell counting, stromal cell growth was reduced following treatment with Connaught Bacillus of Calmette and Guérin (BCG) and Pasteur BCG: Mycobacterium smegmatis demonstrated a cytotoxic effect. Addition of the cytokines interferon (IFN)-gamma or tumour necrosis factor (TNF)-alpha at high concentrations led to a reduction in cell growth by 24 hr in two of three cell lines. A reduction in proliferation was also found when assessed by tritiated thymidine incorporation, which was statistically significant for Connaught BCG and M. smegmatis. CONCLUSIONS: Endometrial stromal cells are susceptible to the anti-proliferative effects of mycobacteria. The BCG and other mycobacteria are known immunomodulators in other disease conditions. Further work is required to assess whether these in vitro effects might translate into a useful therapy for endometriosis.