Search results for "beta"

Susceptibility to collagen-induced arthritis is modulated by TGFβ responsiveness of T cells

2004

The objective of our study was to determine the regulatory effects that endogenous transforming growth factor beta (TGFbeta) exerts on T cells in the pathogenesis of collagen-induced arthritis (CIA). CIA was induced in transgenic mice expressing a dominant negative TGFbeta type II receptor in T cells under the control of the human CD2 promoter. Clinical and histological arthritis scores were determined and experiments on disease induction and the healing phase of disease were performed. The proliferation and cytokine production of draining lymph node cells in vitro were analyzed. Transgenic mice were more susceptible to induction of CIA. The overall incidence was higher in transgenic mice t…

Diacylglycerol-containing oleic acid induces increases in [Ca(2+)](i) via TRPC3/6 channels in human T-cells.

2011

Though most of the studies have focused on the effects of free fatty acids on T-cell activation, fatty acids incorporated into plasma membrane phospholipids may also affect cell signaling via diacylglycerol (DAG), generally produced by phospholipid hydrolysis. In the present study, we have synthesized a DAG-containing oleic acid and studied its implication in the modulation of calcium signaling in human Jurkat T-cells. 1-palmitoyl-2-oleoyl-sn-glycerol (POG) induced a dose-dependent increase in [Ca(2+)](i). This effect was due to the presence of oleic acid at the sn-2 position as no differences were observed between POG and 1-stearoly-2-oleoyl-sn-glycerol (SOG). However, the substitution of …

Gene expression in TGFbeta-induced epithelial cell differentiation in a three-dimensional intestinal epithelial cell differentiation model

2006

Background. The TGFβ1-induced signal transduction processes involved in growth and differentiation are only partly known. The three-dimensional epithelial differentiation model, in which T84 epithelial cells are induced to differentiate either with TGFβ1 or IMR-90 mesenchymal cell-secreted soluble factors, is previously shown to model epithelial cell differentiation seen in intestine. That model has not been used for large scale gene expression studies, such as microarray method. Therefore the gene expression changes were studied in undifferentiated and differentiated three-dimensional T84 cultures with cDNA microarray method in order to study the molecular changes and find new players in e…

Intracellular accumulation of incompletely processed transforming growth factor-alpha polypeptides in ground glass hepatocytes of chronic hepatitis B…

1996

Abstract Background: Transforming growth factor-alpha is an intracellularly processed and secreted polypeptide that induces a proliferative response in epithelial target cells and represents a potential regulatory factor in embryonic development, liver regeneration, and also hepatocarcinogenesis. We have observed focal transforming growth factor-alpha expression in liver tissues with chronic hepatitis B virus infection. Methods: To further elucidate the nature of this focal transforming growth factor-alpha accumulation were have analyzed overall 23 different liver tissues with chronic hepatitis B virus and hepatitis C virus infection as well as normal liver tissues by immunohistology, ELISA…

Polymorphisms of genes of TGF-beta pathway and susceptibility to colorectal cancer

2012

Background: Genetic background implicated in cytokine network may have a key role in the susceptibility to colorectal cancer (CRC). The TGF-β pathway is involved in several biological processes, including cell proliferation, differentiation, migration and apoptosis. Methods: rs1800471 SNP polymorphism of TGF-ß1 rs334348 and rs334349 of TGF-βR1, rs900 of TGF-β2 and rs4522809 of TGF-β2R2 were typed in a group of 82 patients affected by sporadic CRC and in 237 age- and sex-matched healthy controls, using a competitive allele specific PCR assays (KASPar), developed by KBioscience (England). Results: No significant genetic contribution has been observed for 3 of the 5 SNPs tested. Indeed, a sign…

CCL5(RANTES) inhibits TGFbeta1 induced collagen production in human bronchial epithelial cells by action of Smad protein

2009

Airway epithelial cells modulate bronchial remodelling in COPD and asthma. TGF-β1 up-regulation was observed in the bronchial epithelial cells of asthmatics and COPD patients. TGF-β is involved in airways remodelling mainly acting via the Smad pathway. Increased CCL5 was also observed in bronchi of patients with severe COPD. We investigated the effects of TGF-β1 on collagen type I, Smad 3-4 and 7 expression and the effects of CCL5 on TGF-β1-induced collagen production in human bronchial epithelial cells (16HBE).Cells were treated with 10ng/ml of TGF-β1, 10ng/ml of CCL5 and 10ng/ml of both TGF-β1 and CCL5 for 0,3 and 24 hours.TGF-b1 increased Smad3,Smad4 and collagen type I(p=0.0472, p=0.043…

The Activation Status of the TGF-β Transducer Smad2 Is Associated with a Reduced Survival in Gastrointestinal Cancers: A Systematic Review and Meta-A…

2019

Aberrant function of Smad2, a crucial member of transforming growth factor beta (TGF-β) signaling, is associated with the development of malignancies, particularly in the gastrointestinal district. However, little is known about its possible prognostic role in such tumor types. With the first meta-analysis on this topic, we demonstrated that the lack of the activated form of Smad2 (phosphor-Smad2 or pSmad2), which was meant to be the C-terminally phosphorylated form, showed a statistically significant association with an increased risk of all-cause mortality in patients with gastrointestinal cancers (RR, 1.58; 95% CI, 1.05–2.37, p = 0.029, I2 = 84%), also after having adjusted for potential…

Infectious Tolerance

2002

Regulatory CD4(+)CD25(+) T cells (Treg) are mandatory for maintaining immunologic self-tolerance. We demonstrate that the cell-cell contact-mediated suppression of conventional CD4(+) T cells by human CD25(+) Treg cells is fixation resistant, independent from membrane-bound TGF-beta but requires activation and protein synthesis of CD25(+) Treg cells. Coactivation of CD25(+) Treg cells with Treg cell-depleted CD4(+) T cells results in anergized CD4(+) T cells that in turn inhibit the activation of conventional, freshly isolated CD4(+) T helper (Th) cells. This infectious suppressive activity, transferred from CD25(+) Treg cells via cell contact, is cell contact-independent and partially medi…

TGFbeta signaling: roles of Smads

2009

Stem cell replacement therapy in type 1 diabetes

2007

Type 1 diabetes is caused by the autoimmune destruction of pancreatic insulin-producing beta cells and most frequently occurs in genetically susceptible children. Due to beta cell loss, Type 1 diabetes is an ideal candidate for cell replacement therapy. Replacement could be achieved via whole pancreas or isolated islet transplantation, but, at present, feasibility of these procedures is severely limited by the shortage of donor pancreata. Stem cells, characterized by their high potential for self-renewal and the simultaneous ability to differentiate into a desired cytotype, theoretically represent a suitable and renewable source of surrogate beta cells. However, despite many promising resul…