Search results for "Activation"
showing 10 items of 2079 documents
Dynamic regulation of CD8 T cell tolerance induction by liver sinusoidal endothelial cells.
2010
Abstract Cross-presentation of soluble Ag on MHC class I molecules to naive CD8 T cells by liver sinusoidal endothelial cells (LSECs) leads to induction of T cell tolerance that requires interaction between coinhibitory B7-H1 on LSECs and programmed cell death-1 on CD8 T cells. In this study, we investigate whether cross-presentation of high as well as low Ag concentrations allowed for LSEC-induced tolerance. Ag concentration directly correlated with the cross-presentation capacity of murine LSECs and thus strength of TCR stimulation. Although LSEC cross-presentation at low-Ag concentrations resulted in tolerance, they induced differentiation into effector T cells (CTL) at high-Ag concentra…
Stem cell-secreted factor therapy regenerates the ovarian niche and rescues follicles.
2021
Background Ovarian senescence is a normal age-associated phenomenon, but increasingly younger women are affected by diminished ovarian reserves or premature ovarian insufficiency. There is an urgent need for developing therapies to improve ovarian function in these patients. In this context, previous studies suggest that stem cell–secreted factors could have regenerative properties in the ovaries. Objective This study aimed to test the ability of various human plasma sources, enriched in stem cell–secreted factors, and the mechanisms behind their regenerative properties, to repair ovarian damage and to promote follicular development. Study Design In the first phase, the effects of human pla…
Oxidant stress and endothelial activation in hypertensive patients with and without left ventricular hypertrophy
2006
In Vitro Evaluation of the Squaramide-Conjugated Fibroblast Activation Protein Inhibitor-Based Agents AAZTA5.SA.FAPi and DOTA.SA.FAPi
2021
Recently, the first squaramide-(SA) containing FAP inhibitor-derived radiotracers were introduced. DATA5m.SA.FAPi and DOTA.SA.FAPi with their non-radioactive complexes showed high affinity and selectivity for FAP. After a successful preclinical study with [68Ga]Ga-DOTA.SA.FAPi, the first patient studies were realized for both compounds. Here, we present a new squaramide-containing compound targeting FAP, based on the AAZTA5 chelator 1,4-bis-(carboxylmethyl)-6-[bis-(carboxymethyl)-amino-6-pentanoic-acid]-perhydro-1,4-diazepine. For this molecule (AAZTA5.SA.FAPi), complexation with radionuclides such as gallium-68, scandium-44, and lutetium-177 was investigated, and the in vitro properties of…
Analysis of phosphorylation-dependent modulation of Kv1.1 potassium channels.
2003
The voltage-gated potassium channel Kv1.1 contains phosphorylation sites for protein kinase A (PKA) and protein kinase C (PKC). To study Kv1.1 protein expression and cellular distribution in regard to its level of phosphorylation, the effects of PKA and PKC activation on Kv1.1 were investigated in HEK 293 cells stably transfected with Kv1.1 (HEK 293/1). Without kinase activation, HEK 293/1 cells carry unphosphorylated Kv1.1 protein in the plasma membranes, whereas large amounts of phosphorylated and unphosphorylated Kv1.1 protein were located intracellularly. Activation of PKA resulted in phosphorylation of intracellular Kv1.1 protein, followed by a rapid translocation of Kv1.1 into the pla…
Expression of Transketolase-like 1 and Activation of Akt in Grade IV Glioblastomas Compared With Grades II and III Astrocytic Gliomas
2008
Transketolases link the Embden-Meyerhof pathway to the pentose phosphate pathway. An influence of p-Akt on this metabolism was described. This study was performed to compare the expression of transketolase-like 1 (TKTL1) and p-Akt in glioblastoma multiforme (GBM) and other astrocytic gliomas (AGs, grades II and III). We analyzed 15 GBMs, 15 AGs (grade II), and 3 normal brain samples for TKTL1 expression by semiquantitative reverse transcription–polymerase chain reaction and Western blotting and 23 GBMs, 9 grade III AGs, and 7 grade II AGs immunohistochemically (TKTL1 and p-Akt). On the protein level, TKTL1 was significantly overexpressed in tumors. Immunohistochemically, the tumor grade sig…
Collagenase-3 (MMP-13) Enhances Remodeling of Three-Dimensional Collagen and Promotes Survival of Human Skin Fibroblasts
2006
Collagenase-3 (MMP-13) is a matrix metalloproteinase capable of cleaving a multitude of extracellular matrix proteins in addition to fibrillar collagens. Human MMP-13 is expressed by fibroblasts in chronic cutaneous ulcers, but not in normally healing adult skin wounds. However, MMP-13 is produced by fibroblasts in adult gingival and in fetal skin wounds characterized by rapid collagen remodeling and scarless healing. Here, we have examined the role of human MMP-13 in remodeling of three-dimensional (3D) collagenous matrix by primary adult human skin fibroblasts. The high level of human MMP-13 expression by fibroblasts achieved by adenoviral gene delivery resulted in potent enhancement of r…
Novel contributions of neutrophils in the pathogenesis of abdominal aortic aneurysm, the role of neutrophil extracellular traps: A systematic review.
2020
Abdominal aortic aneurysm (AAA) is a vascular disorder caused by a dilatation of the aortic diameter that can be potentially lethal in case of rupture. Molecular mechanisms underlying the development of AAA are complex and not completely understood. However, inflammation plays a pivotal role in AAA development. Infiltration of inflammatory cells, especially macrophages, has been widely observed in lesion areas. Nevertheless, neutrophils have been gaining importance in the context of AAA. The release of neutrophil extracellular traps (NETs), extracellular structures formed by DNA, histones, granular and cytoplasmic proteins, is a recently discovered mechanism of neutrophil activation that ca…
Fibroblast activation protein inhibitor (FAPi) positive tumour fraction on PET/CT correlates with Ki-67 in liver metastases of neuroendocrine tumours
2021
Abstract Aim Gallium-68-labelled inhibitors of the fibroblast activation protein (FAPi) enable positron emission tomography/computed tomography (PET/CT) imaging of fibroblast activation. We evaluated if [68Ga]Ga-DATA5m.SA.FAPi PET/CT is related to Ki-67 as a marker of tumour aggressiveness in patients with liver metastases of NET. Methods Thirteen patients with liver metastases of a histologically confirmed NET who underwent PET/CT with [68Ga]Ga-DATA5m.SA.FAPi, [18F]FDG and [68Ga]Ga-DOTA-TOC were retrospectively analyzed. PET-positive liver tumour volumes were segmented for calculation of volume, SUVmax and PET-positive tumour fraction (TF). PET parameters were correlated with Ki-67. Result…