|
| ||
|
|
||
Cell Supernatants (cell + supernatant)
Selected AbstractsComparison of cytotoxic and inflammatory responses of photoluminescent silicon nanoparticles with silicon micron-sized particles in RAW 264.7 macrophagesJOURNAL OF APPLIED TOXICOLOGY, Issue 1 2009Jonghoon Choi Abstract Photoluminescent silicon nanoparticles have a bright and stable fluorescence and are promising candidates for bio-imaging, cell staining and drug delivery. With increasing development of nanotechnology applications for biomedicine, an understanding of the potential toxicity of nanoparticles is needed to assess safety concerns for clinical applications. The objective of this study was to compare biological responses of silicon nanoparticles (SNs, 3 nm diameter) with silicon microparticles (SMs, ,100,3000 nm diameter) in cultured murine macrophages (RAW 264.7) using standard protocols for assessing cytotoxicity/cell viability and inflammatory responses developed for micron-sized particles. SNs and SMs were exposed to macrophages with and without addition of endotoxin lipopolysaccharide (LPS), a positive inducer of tumor necrosis factor-alpha (TNF- ,), interleukin 6 (IL-6), and nitric oxide (NO). Cytotoxicity was assayed using the dye exclusion and MTT assays. Cell supernatants were assayed for production TNF- ,, IL-6 and NO. SNs at concentrations ,20 µg ml,1 exhibited no cytotoxicity or inflammatory responses; however, SNs and SMs >20 and 200 µg ml,1, respectively, increased cytotoxicity compared with controls. SMs induced concentration-related increases in TNF- , and IL-6 production; in contrast, the production of these cytokines was shown to decrease with increasing concentrations of SNs. NO production was not induced by SNs or SMs alone. Fluorescence microscopy demonstrated that SNs were associated with the macrophages, either internalized or attached to cell membranes. In conclusion, evaluating differences in biological responses for nanoparticles compared with microparticles of the same material may help improve tests to assess biological responses of nanoparticles that may be used in biomedical applications. Copyright © 2008 John Wiley & Sons, Ltd. [source] Keratinocytes: a source of the transmitter l -glutamate in the epidermisEXPERIMENTAL DERMATOLOGY, Issue 12 2009Matthias Fischer Abstract:, Various glutamate receptors have been described in both keratinocytes and melanocytes. l -Glutamate is the physiological agonist of the glutamate receptor family. The source of this transmitter had not yet been identified. In normal human epidermal keratinocytes (NHEK) and HaCaT-keratinocytes, cell supernatants were sampled in various stages of cell density and the l -glutamate content photometrically determined. The following examination time-points were defined: non-confluent (ca. 33%), subconfluent (ca. 70%) and confluent (90,100%). The l -glutamate concentration originally in the culture medium was 14.7 mg/l (0.1 mm/l). The l -glutamate concentration in the cell supernatant increased in NHEK with increasing cell density: non-confluent 39.9 ± 4 mg/l, subconfluent 60.6 ± 15.8 mg/l, confluent 100.7 ± 33.2 mg/l. A linear increase of l -glutamate concentration was also found for HaCaT cells. The investigations show that keratinocytes are capable of producing and releasing l -glutamate. Thus they are a source of l -glutamate which acts as a transmitter on epidermal glutamate receptors. [source] Potential mechanisms for astrocyte-TIMP-1 downregulation in chronic inflammatory diseasesJOURNAL OF NEUROSCIENCE RESEARCH, Issue 7 2006Jessica Gardner Abstract The pathogenesis of many neurodegenerative disorders, including human immunodeficiency virus (HIV)-1 associated dementia, is exacerbated by an imbalance between matrix metalloproteinases (MMPs) and their inhibitors, tissue inhibitors of metalloproteinases (TIMPs). In the context of disease, TIMP-1 has emerged as an important multifunctional protein capable of regulating inflammation. We previously reported differential TIMP-1 expression in acute versus chronic activation of astrocytes. This study investigates possible mechanisms underlying TIMP-1 downregulation in chronic neuroinflammation. We used interleukin (IL)-1, as a model pro-inflammatory stimulus and measured TIMP-1 binding to extracellular matrix, cell death, receptor downregulation, TIMP-1 mRNA stability and transcriptional regulation in activated astrocytes. TIMP-1 remained localized to the cell body or was secreted into the cell supernatant. DNA fragmentation ELISA and MTT assay showed that prolonged IL-1, activation of astrocytes induced significant astrocyte death. In acute and chronic IL-1,-activated astrocytes, IL-1 receptor levels were not significantly different. TIMP-1 mRNA stability was measured in astrocytes and U87 astroglioma cells by real-time PCR, and TIMP-1 promoter activation was studied using TIMP-1-luciferase reporter constructs in transfected astrocytes. Our results indicated that TIMP-1 expression is regulated through multiple mechanisms. Transcriptional control and loss of mRNA stabilization are, however, the most likely primary contributors to chronic downregulation of TIMP-1. These data are important for unraveling the mechanisms underlying astrocyte responses during chronic neuroinflammation and have broader implications in other inflammatory diseases that involve MMP/TIMP imbalance. © 2006 Wiley-Liss, Inc. [source] Two adult siblings with atypical cryopyrin-associated periodic syndrome due to a novel M299V mutation in NLRP3ARTHRITIS & RHEUMATISM, Issue 7 2010Deepti Verma Objective The NALP3 inflammasome is a multiprotein complex that triggers caspase 1,mediated interleukin-1, (IL-1,) release. Mutations in the gene encoding NALP3 (NLRP3) underlie the cryopyrin-associated periodic syndrome (CAPS). The aim of this study was to report a novel NLRP3 mutation in 2 siblings of Swedish descent in whom symptoms first presented in adulthood. Methods Mutation analysis of NLRP3 was performed on DNA from patients with CAPS and 100 control subjects. For assessment of caspase 1 and IL-1,, blood was collected from patients and age- and sex-matched healthy control subjects. Genetic constructs containing mutant or wild-type NLRP3 were transduced into THP-1 cells, followed by assessment of IL-1, levels in cell supernatant. Results Both siblings carried a novel M299V mutation in NLRP3, which was not present in the control population. The samples obtained from the patients displayed increased caspase 1 activity and elevated IL-1, levels at basal conditions as compared with healthy control subjects. THP-1 cells expressing mutated M299V revealed almost 10-fold higher IL-1, production compared with the wild-type construct. Conclusion M299V is an activating mutation in NLRP3 resulting in elevated spontaneous caspase 1 activity and IL-1, levels. The classic CAPS phenotype was lacking in these adult siblings. Whereas one sibling displayed a milder phenotype that has so far responded satisfactorily to oral nonsteroidal antiinflammatory drugs in combination with low-dose corticosteroids, the inflammatory symptoms in the sibling with the more severe case responded well to IL-1, blockade. Understanding the pathogenic mechanism underlying such disorders can be helpful for the physician. Our study reinforces the importance of genetic testing and laboratory investigations in combination with careful phenotypic evaluation for the diagnosis of such patients. [source] Modulation of selenoprotein P expression by TGF-,1 is mediated by Smad proteinsBIOFACTORS, Issue 1-4 2001Volker Mostert Abstract Selenoprotein P (SeP) is a selenium-rich plasma protein which accounts for more than 50% this study, the effect of TGF-,1 on the expression of SeP in the human liver cell line HepG2 was investigated. Western analysis revealed a dose-dependent reduction of SeP content in cell supernatant. RT-PCR analysis of SeP-mRNA expression demonstrated a marked inhibition and a reporter gene under control of the SeP promoter was negatively regulated by TGF-,1. Smad proteins are the transcriptional mediators of TGF-, signaling. A putative Smad-binding element (SBE) is present in the SeP promoter. In electrophoretic-mobility-shift assays, TGF-,1 enhanced the binding of nuclear proteins to this SBE. Overexpression of Smad3 and 4 resulted in a downregulation of SeP-promoter activity whereas deletion of the SBE led to a loss of TGF-,1 responsiveness. We conclude that SeP expression is modulated by the binding of Smad3/4 complexes to a functional SBE in the SeP promoter. [source] Keratinocytes: a source of the transmitter l -glutamate in the epidermisEXPERIMENTAL DERMATOLOGY, Issue 12 2009Matthias Fischer Abstract:, Various glutamate receptors have been described in both keratinocytes and melanocytes. l -Glutamate is the physiological agonist of the glutamate receptor family. The source of this transmitter had not yet been identified. In normal human epidermal keratinocytes (NHEK) and HaCaT-keratinocytes, cell supernatants were sampled in various stages of cell density and the l -glutamate content photometrically determined. The following examination time-points were defined: non-confluent (ca. 33%), subconfluent (ca. 70%) and confluent (90,100%). The l -glutamate concentration originally in the culture medium was 14.7 mg/l (0.1 mm/l). The l -glutamate concentration in the cell supernatant increased in NHEK with increasing cell density: non-confluent 39.9 ± 4 mg/l, subconfluent 60.6 ± 15.8 mg/l, confluent 100.7 ± 33.2 mg/l. A linear increase of l -glutamate concentration was also found for HaCaT cells. The investigations show that keratinocytes are capable of producing and releasing l -glutamate. Thus they are a source of l -glutamate which acts as a transmitter on epidermal glutamate receptors. [source] A dominant role for chemoattractant receptor-homologous molecule expressed on T helper type 2 (Th2) cells (CRTH2) in mediating chemotaxis of CRTH2+ CD4+ Th2 lymphocytes in response to mast cell supernatantsIMMUNOLOGY, Issue 3 2006Shân L. Gyles Summary Human cultured mast cells, immunologically activated with immunoglobuin E (IgE)/anti-IgE, released a factor(s) that promoted chemotaxis of human CRTH2+ CD4+ T helper type 2 (Th2) lymphocytes. Mast cell supernatants collected at 20 min, 1 hr, 2 hr and 4 hr after activation caused a concentration-dependent increase in the migration of Th2 cells. The effect of submaximal dilutions of mast-cell-conditioned media was inhibited in a dose-dependent manner by ramatroban (IC50 = 96 nm), a dual antagonist of both the thromboxane-like prostanoid (TP) receptor and the chemoattractant receptor-homologous molecule expressed on Th2 cells (CRTH2), but not by the selective TP antagonist SQ29548, implicating CRTH2 in mediating the chemotactic response of these Th2 cells. The effect of mast-cell-conditioned media was mimicked by prostaglandin D2 (PGD2) and this eicosanoid was detected in the conditioned media from activated mast cells in concentrations sufficient to account for the activity of the mast cell supernatants. Treatment of the mast cells with the cyclo-oxygenase inhibitor diclofenac (10 ,m) inhibited both the production of PGD2 and the CRTH2+ CD4+ Th2-stimulatory activity, while addition of exogenous PGD2 to conditioned media from diclofenac-treated mast cells restored the ability of the supernatants to promote chemotaxis of these Th2 cells. The degree of inhibition caused by diclofenac treatment of the mast cells was concordant with the degree of inhibition of chemotactic responses afforded by CRTH2 blockade. These data suggest that PGD2, or closely related metabolites of arachidonic acid, produced from mast cells may play a central role in the activation of CRTH2+ CD4+ Th2 lymphocytes through a CRTH2-dependent mechanism. [source] An optimized method for intensive screening of molecules that stimulate , -defensin 2 or 3 (hBD2 or hBD3) expression in cultured normal human keratinocytesINTERNATIONAL JOURNAL OF COSMETIC SCIENCE, Issue 3 2005I. Pernet Synopsis Normal human skin controls the intrusion of microorganisms by the production of peptide antibiotics such as defensins. The aim of our study was to develop a culture model of normal human keratinocytes for optimal , -defensin mRNA detection which allows the screening of molecules able to stimulate hBD2 and hBD3 without inducing pro-inflammatory cytokines. A keratinocyte culture model in 96-well plates, in high calcium medium (1.7 mm) allowed to analyze hBD2 and hBD3 mRNA expression in basal condition and after cell stimulation by products from diverse vegetal extracts. The release of IL-8 and the chemokine MIP-3, was also evaluated in cell supernatants by ELISA. Among the 184 extracts tested, 75 showed a stimulatory effect on , -defensin expression: 40 on hBD2, 26 on hBD3 and nine on both defensins. Fifteen of these substances which also induced the release of pro-inflammatory cytokines were eliminated. Among the other substances, four were selected and were analyzed in a dose-dependent study (n = 4) by real-time quantitative RT-PCR and completed by a measure of MIP-3,, IL-8 and IL-1, levels. These data underline the important necessity of screening result controls by a quantitative method reproduced at least three times. This new method of intensive screening allowed us to exhibit vegetal extracts that were able to stimulate epidermal , -defensin expression without inducing an up-secretion of pro-inflammatory cytokines. Résumé La peau humaine normale exerce une fonction barrière contre l'intrusion de microorganismes par la production de peptides antibiotiques comme les défensines. Le but de cette étude a consistéà mettre au point un modèle de culture de kératinocytes humains normaux permettant une détection optimale des ARNm des défensines en général, et adapté au screening de molécules aptes à stimuler les défensines épidermiques hBD2 et hBD3 en particulier, sans induire de cytokines pro-inflammatoires. Un modèle de culture de kératinocytes en plaques 96 puits, en milieu riche en calcium (1,7 mm) permet une analyse de l'expression des ARNm de hBD2 et hBD3 en condition basale et après stimulation par divers extraits végétaux. La sécrétion d'IL-8 et de la chimiokine MIP-3, a étéévaluée dans les surnageants de culture par ELISA. Parmi les 184 extraits testés, 75 montrent un effet stimulant sur l'expression des , -défensines : 40 ont un effet sur hBD2, 26 sur hBD3 et 9 sur les 2 types de défensines. Quinze de ces actifs qui induisent aussi la sécrétion de cytokines pro-inflammatoires ont étééliminés. Parmi les autres molécules, 4 ont été sélectionnées pour faire l'objet d'une étude de leurs effets-doses (n = 4) sur l'expression des , -défensines par une technique quantitative de RT-PCR en temps réel. Cette étude est complétée par le dosage des cytokines IL-1,, IL-8 et MIP-3,. Les résultats obtenus soulignent l'importante nécessitée de contrôler au moins trois fois par une méthode quantitative les résultats d'un screening. Cette nouvelle méthode de screening intensif nous a permis de mettre en évidence des extraits végétaux capables de stimuler les défensines épidermiques sans induire de cytokines pro-inflammatoires. [source] Expression of vip1/vip2 genes in Escherichia coli and Bacillus thuringiensis and the analysis of their signal peptidesJOURNAL OF APPLIED MICROBIOLOGY, Issue 4 2004Y. Shi Abstract Aims:, To determine the expression time courses and high expression level of Vip2A(c) and Vip1A(c) in Bacillus thuringiensis, and survey their insecticidal toxicity and insecticidal spectrum. Methods and Results:, A kind of new vegetative insecticidal toxin genes encoded by a single operon from B. thuringiensis had been cloned and sequenced. The individual genes, 5-terminus truncated genes and the operon were respectively expressed in Escherichia coli. Only N-terminus deleted Vip2A(c) and Vip1A(c) proteins could be purified by Ni-NTA agarose, while others were processed and their N-terminal signal peptides were cleaved. The individual genes and the operon were also expressed in B. thuringiensis. Both proteins were mostly secreted into the cell supernatants. The expression level of Vip1A(c) was influenced because of the interruption of vip2A(c) gene on the operon. Bioassays showed that neither separate protein nor both performed any toxicity against tested lepidopteran and coleopteran insects. Conclusions:, Vip2A(c) and Vip1A(c) have similar secretion mechanism in E. coli and B. thuringiensis. Vip1A(c) remained its high expression level only when being expressed with vip2A(c) gene as an operon in B. thuringiensis. Significance and Impact of the Study:, Expression of vip2A(c) and vip1A(c) genes in E. coli and B. thuringiensis were investigated. This would help to make clear the secretion mechanism of VIP proteins and study the function of ADP-ribosyltransferase Vip2. [source] Beryllium-stimulated neopterin as a diagnostic adjunct in chronic beryllium diseaseAMERICAN JOURNAL OF INDUSTRIAL MEDICINE, Issue 6 2003Lisa A. Maier MD, MSPH Abstract Background The diagnosis of chronic beryllium disease (CBD) relies on the beryllium lymphocyte proliferation test (BeLPT) to demonstrate a Be specific immune response. This test has improved early diagnosis, but cannot discriminate beryllium sensitization (BeS) from CBD. We previously found high neopterin levels in CBD patients' serum and questioned whether Be-stimulated neopterin production by peripheral blood cells in vitro might be useful in the diagnosis of CBD. Methods CBD, BeS, Be exposed workers without disease (Be-exp) normal controls and sarcoidosis subjects were enrolled. Peripheral blood mononuclear cells (PBMN) were cultured in the presence and absence of beryllium sulfate. Neopterin levels were determined from cell supernatants by enzyme linked immunosorbent assay (ELISA). Clinical evaluation of CBD subjects included chest radiography, pulmonary function testing, exercise testing, and the BeLPT. Results CBD patients produced higher levels of neopterin in both unstimulated and Be-stimulated conditions compared to all other subjects (P,<,0.0001). Unstimulated neopterin mononuclear cell levels overlapped among groups, however, Be-stimulated neopterin levels in CBD showed little overlap. Using a neopterin concentration of 2.5 ng/ml as a cutoff, Be-stimulated neopterin had a sensitivity of 80% and specificity of 100% for CBD and was able to differentiate CBD from BeS. Be-stimulated neopterin was inversely related to measures of pulmonary function, exercise capacity, and gas exchange. Conclusions Neopterin may be a useful diagnostic adjunct in the non-invasive assessment of CBD, differentiating CBD from BeS. Further studies will be required to determine how it performs in workplace screening. Am. J. Ind. Med. 43:592,601, 2003. © 2003 Wiley-Liss, Inc. [source] Gender differences in transcriptional regulation of IL-5 expression by bronchial lymph node cells in a mouse model of asthmaRESPIROLOGY, Issue 4 2010Kana WADA ABSTRACT Background and objective: The severity of asthma after puberty is higher in women than in men. Increased numbers of eosinophils in the airways of female mice after antigen challenge was associated with increased levels of T helper (Th)2 cytokines at the site of inflammation, and in human and mouse studies, the profile of cytokines produced by immune cells from women showed greater Th2 predominance. The aim of this study was to investigate gender differences in the development of Th2 immune responses. Methods: Male and female C57BL/6 mice were sensitized with ovalbumin. Cells prepared from bronchial lymph nodes were cultured in the absence or presence of ovalbumin. Cytokine concentrations in the culture supernatants were measured, and IL-5 and GATA-binding protein 3 (GATA-3) gene expression were evaluated. T-cell subsets were analysed using specific surface markers. Results: The concentrations of IL-4, IL-5, IL-13 and IL-10, but not interferon-, or transforming growth factor-,1, were higher in cell supernatants from female mice than in those from male mice. IL-5 and GATA-3 gene expressions were higher in cells from women than in cells from men. The numbers of CD3+CD4+T1/ST2+ cells, but not CD3+CD4+ or CD4+CD25+ cells, were significantly higher in cells from women than in cells from men. Conclusions: Greater antigen-induced Th2 cytokine production by bronchial lymph node cells from female mice was associated with enhanced Th2 cell differentiation and increased expression of the Th2-specific transcription factor, GATA-3. [source] Transforming growth factor-,1 and ultraviolet A1 radiation increase production of vascular endothelial growth factor but not endothelin-1 in human dermal fibroblastsBRITISH JOURNAL OF DERMATOLOGY, Issue 3 2000S. Trompezinski Background ,Normal and dysregulated wound healing involves fibroblast activation and angiogenesis, in which polypeptide factors such as transforming growth factor (TGF)-,, vascular endothelial growth factor (VEGF) and endothelin-1 (ET-1) play an important part. Ultraviolet (UV) A1 (365 nm) has recently received attention as a possible treatment for some dermal fibrotic disorders. Objectives,The aim of this study was to evaluate the effects of TGF-,1 and UVA1 radiation, as well as that of cobalt chloride, reported to mimic hypoxia both in vivo and in vitro, on the expression of VEGF and ET-1 by cultured human dermal fibroblasts. Methods,Levels of VEGF and ET-1 were measured by enzyme-linked immunosorbent assay and expression of neutral endopeptidase (NEP, CD10), known to degrade ET-1, was quantified by flow cytometric analysis after cell trypsinization. Results,Our results showed that the cells released minor amounts of VEGF and ET-1. Both TGF-,1 and UVA1 strongly increased VEGF secretion in a dose- and time-dependent manner, without significantly affecting ET-1 release. Irradiation of TGF-,1-stimulated fibroblasts resulted in a synergistic effect on increasing levels of VEGF but not ET-1 after 48 h. Cobalt chloride stimulated the secretion of VEGF by fibroblasts; the effects of TGF-,1 and cobalt were additive. However, no significant effect of cobalt chloride on ET-1 secretion was observed, suggesting that ET-1 production in fibroblasts is not oxygen-sensitive. The expression of NEP was not modified by TGF-,1 or UVA1 radiation. Addition of a neutralizing anti-CD10 antibody to fibroblast cultures downregulated CD10 expression at the cell surface without changing ET-1 levels in cell supernatants after 24 or 48 h. This suggests that membrane-bound NEP has minimal or no activity against secreted ET-1. Conclusions,Taken together, these results underline the major role played by TGF-,1 in increasing VEGF secretion by fibroblasts. This, as well as the documented effect of UVA1 on increasing VEGF production, may have implications for wound healing in vivo. [source] Vitamin D and glucocorticoids differentially modulate chemokine expression in human airway smooth muscle cellsBRITISH JOURNAL OF PHARMACOLOGY, Issue 1 2008A Banerjee Background and purpose: Chemokines play a critical role in the pathogenesis of asthma and facilitate the recruitment of inflammatory cells in the airways. Evidence now suggests that airway smooth muscle (ASM) may serve as a source of chemokines in inflamed airways. Although vitamin D has potent anti-inflammatory properties in vitro in some cell types, its effects on ASM cells remain unclear. Here, we investigated whether 1,, 25-dihydroxy vitamin D3 (calcitriol) modulated chemokine production in ASM. Experimental approach: Human ASM cell cultures were derived from tracheal samples taken during surgery. ASM cells were treated with tumour necrosis factor alpha (TNF,) and/or interferon gamma (IFN,) for 24 h in the presence of calcitriol and/or the glucocorticoid fluticasone added 2 h before. RANTES (regulated upon activation, normal T-cell expressed and secreted), interferon-inducible protein 10 (IP-10) and fractalkine (FKN) levels in cell supernatants were measured by ELISA. Key results: In TNF,-treated cells, calcitriol inhibited RANTES and IP-10 secretion in a concentration-dependent manner. FKN levels were negligible. In TNF,/IFN,-treated cells, whereas fluticasone or calcitriol alone partially inhibited RANTES secretion (by 38 and 20%, respectively), the combination of both drugs additively inhibited RANTES secretion (by 60%). No effect was observed on IP-10 secretion. Whereas fluticasone enhanced FKN secretion (by 50%), calcitriol significantly decreased FKN levels (by 50%). Interestingly, calcitriol blocked the stimulatory effect of fluticasone on FKN secretion, which was inhibited by 60% with the combination of calcitriol and fluticasone. Conclusions and implications: These findings suggest that vitamin D uniquely modulates human ASM expression of chemokines and may exert some beneficial effects in the treatment of steroid-resistant patients with asthma. British Journal of Pharmacology (2008) 155, 84,92; doi:10.1038/bjp.2008.232; published online 16 June 2008 [source] T cells and eosinophils in bronchial smooth muscle cell death in asthmaCLINICAL & EXPERIMENTAL ALLERGY, Issue 6 2009K. Solarewicz-Madejek Summary Background Bronchial smooth muscle cells (SMC) proliferate, express adhesion molecules, secrete cytokines and thus efficiently contribute to the pathogenesis of asthma. Objective The aim of the study was to investigate whether, and by which mechanism, T cells and eosinophils can cause death of airway SMC. Methods The T cell- and eosinophil-induced cell death was analysed in primary human bronchial SMC cultures as well as in bronchial biopsy specimens from non-asthmatic and asthmatic individuals. Results Bronchial SMC death showed characteristic morphological features of apoptosis in 3,6 days cultures with inflammatory cytokines (IFN-,, TNF-,), soluble death ligands [sFasL, TNF-related apoptosis-inducing ligand (TRAIL)] and activated T-helper type 1 (Th1) and Th2 cell supernatants. The recombinant eosinophil cationic protein induced SMC necrosis within 1 h. Resting SMC expressed the death receptors TNFR1, TNFR2, Fas, TRAILR1, TRAILR2 and membrane FasL as a death-inducing ligand. IFN-, and TNF-, up-regulated TNFR1, TNFR2, Fas and membrane FasL on SMC. TNF-, up-regulated TRAILR1 and TRAILR2; sFasL up-regulated TNFR2. The intracellular caspase-3 activation in SMC was significantly increased by IFN-,, sFasL, TRAIL, Th1 and Th2 cell supernatants. Increased expression of TRAIL in asthmatics, but not in non-asthmatic individuals was demonstrated in situ. The apoptosis receptors TRAILR1 and TRAILR2 were expressed in SMC and epithelial cells both in healthy and asthmatic biopsies. Prominent apoptosis of SMC was observed in fatal asthma, but not intermittent asthma biopses. Conclusion The demonstration of bronchial SMC death both by apoptosis and necrosis indicates the essential role of T cells and eosinophils in the bronchial tissue injury particularly in the severe asthma. [source] | |||||||||||||