Search results for "Ostas"

Midgut pseudotumors and the maintenance of tissue homeostasis: studies on aging and manipulated stick insects.

2009

Stick insects (Carausius morosus) develop pseudotumors in aging adults. Pseudotumor formation starts at the M2 midgut region where an accumulation of stomatogastric nerve terminals is observed. Pseudotumors arise from dying columnar cells whose basal parts form an “amorphous substance” at the basement membrane whereas the apical parts, including the nucleus, are expelled into the gut lumen. The “amorphous substance” is ensheathed by hemocytes. These nodules, which do not melanize, characterize the phenotype of the pseudotumors. With age, cell death and pseudotumor infestation increases. It is shown that the maintenance of midgut tissue homoeostasis is disturbed and becomes more serious with…

2020

Cilia are cellular organelles that project from the cell. They occur in nearly all non-hematopoietic tissues and have different functions in different tissues. In mesenchymal tissues primary cilia play a crucial role in the adequate morphogenesis during embryological development. In mature articular cartilage, primary cilia fulfil chemo- and mechanosensitive functions to adapt the cellular mechanisms on extracellular changes and thus, maintain tissue homeostasis and morphometry. Ciliary abnormalities in osteoarthritic cartilage could represent pathophysiological relationships between ciliary dysfunction and tissue deformation. Nevertheless, the molecular and pathophysiological relationships…

Gènes fongiques liés au calcium impliqués dans la mycorhize à arbuscules

2012

Fluctuations in intracellular (Ca2+) calcium levels generate signaling events and regulate different cellular processes. Whilst the implication of Ca2+ in plant cell responses during arbuscular mycorrhiza (AM) interactions is well documented, nothing is known about the regulation or role of this secondary meesenger in the fungal symbiont. The molecular basis of fungal calcium homeostasis in the AM symbiosis was analyzed by investigating the expression of Ca2+-related fungal genes. In a first study, G. mosseae genes putatively encoding a MAP3k-like protein kinase (Gm2) and a P-type ATPase (Gm152) were investigated. Both Ca2+-related genes were up-regulated by A. sinicum root exudates, sugges…

Neuroglobin and Cytoglobin

2008

Neuroglobin and cytoglobin are two recent additions to the family of heme-containing respiratory proteins of man and other vertebrates. Here, we summarize the current state of knowledge of the structures, ligand-binding kinetics, evolution, and expression patterns of these two proteins. These data provide working hypotheses with regard to the possible physiological roles of these globins in the animal's metabolism. Both neuroglobin and cytoglobin are structurally similar to myoglobin, but they contain distinct features like extraordinarily high temperature resistances and unusual cavities inside the molecules. Kinetic and structural studies show that neuroglobin and cytoglobin belong to the…

Procoagulant activity during viral infections.

2017

The abundance of evidence suggest that inflammation of immune and non-immune cells may lead to an imbalance of the pro- and anti-coagulant state during viral infections. During systemic infections, the endothelium plays a critical role in regulating hemostasis, and severe imbalances of endothelial function and activation can contribute to organ failure. Viral infections may elevate plasma levels of procoagulant markers such as TAT and D-dimer TF-positive MPs as well as von Willebrand factor (vWF). Although multiple clinical studies are showing the association of viral infection and increased prothrombotic risk, the pathological mechanisms have not been fully identified for most viral infect…

Hypoxia and HIF Signaling: One Axis with Divergent Effects

2020

The correct concentration of oxygen in all tissues is a hallmark of cellular wellness, and the negative regulation of oxygen homeostasis is able to affect the cells and tissues of the whole organism. The cellular response to hypoxia is characterized by the activation of multiple genes involved in many biological processes. Among them, hypoxia-inducible factor (HIF) represents the master regulator of the hypoxia response. The active heterodimeric complex HIF α/β, binding to hypoxia-responsive elements (HREs), determines the induction of at least 100 target genes to restore tissue homeostasis. A growing body of evidence demonstrates that hypoxia signaling can act by generating contrasting res…

Adult Stem Cell-Derived Extracellular Vesicles in Cancer Treatment: Opportunities and Challenges

2020

Adult stem cells (SCs) participate in tissue repair and homeostasis regulation. The relative ease of SC handling and their therapeutic effect has made of these cell popular candidates for cellular therapy. However, several problems interfere with their clinical application in cancer treatment, like safety issues, unpredictable pro-tumour effects, and tissue entrapment. Therefore cell-free therapies that exhibit SC properties are being investigated. It is now well known that adult SCs exhibit their therapeutic effect via paracrine mechanisms. In addition to secretory proteins, SCs also release extracellular vesicles (EV) that deliver their contents to the target cells. Cancer treatment is on…

P2.10 Summation of afferent input affects sympathetic homeostasis: Mild skin tactile stimulation during painful isometric muscle contraction reduces …

2009

Increased stability of the TM helix oligomer abrogates the apoptotic activity of the human Fas receptor

2021

Human death receptors control apoptotic events during cell differentiation, cell homeostasis and the elimination of damaged or infected cells. Receptor activation involves ligand-induced structural reorganizations of preformed receptor trimers. Here we show that the death receptor transmembrane domains only have a weak intrinsic tendency to homo-oligomerize within a membrane, and thus these domains potentially do not significantly contribute to receptor trimerization. However, mutation of Pro183 in the human CD95/Fas receptor transmembrane helix results in a dramatically increased interaction propensity, as shown by genetic assays. The increased interaction of the transmembrane domain is co…

Temporal Monitoring of Differentiated Human Airway Epithelial Cells Using Microfluidics

2015

The airway epithelium is exposed to a variety of harmful agents during breathing and appropriate cellular responses are essential to maintain tissue homeostasis. Recent evidence has highlighted the contribution of epithelial barrier dysfunction in the development of many chronic respiratory diseases. Despite intense research efforts, the responses of the airway barrier to environmental agents are not fully understood, mainly due to lack of suitable in vitro models that recapitulate the complex in vivo situation accurately. Using an interdisciplinary approach, we describe a novel dynamic 3D in vitro model of the airway epithelium, incorporating fully differentiated primary human airway epith…