Search results for " homeostasis"

ENDOCRINE SIDE EFFECTS OF ANTI-CANCER DRUGS: Effects of anti-cancer targeted therapies on lipid and glucose metabolism

2014

During the past years, targeted therapies for cancer have been developed using drugs that have significant metabolic consequences. Among them, the mammalian target of rapamycin (mTOR) inhibitors and, to a much lesser extent, the tyrosine kinase inhibitors (TKIs) are involved. mTOR plays a key role in the regulation of cell growth as well as lipid and glucose metabolism. Treatment with mTOR inhibitors is associated with a significant increase in plasma triglycerides and LDL cholesterol. mTOR inhibitors seem to increase plasma triglycerides by reducing the activity of the lipoprotein lipase which is in charge of the catabolism of triglyceride-rich lipoproteins. The increase in LDL cholesterol…

Calcium Metabolism in the Elderly

1998

Mineral homeostasis represents one of the multiple areas at risk in the elder population. This includes the ion calcium, which is the most abundant inorganic element in the human body and an essential key for many physiologic processes (1).

Calcium Absorption in Health and Disease

1972

Calcium (Ca) metabolism and intestinal Ca absorption have attracted special attention ever since the discovery of vitamin D and the definition of the clinical entities of disturbances of Ca homeostasis in the first three decades of this century. Since then, many details of Ca transport and vitamin D metabolism have accumulated, but only in very recent years have new ideas and findings brought about rapid progress in this field. There is now a startling activity in the investigation of the physiology and pathogenesis of vitamin D and Ca metabolism.

Circuit Specific Functions of Cannabinoid CB1 Receptor in the Balance of Investigatory Drive and Exploration

2011

Well balanced novelty seeking and exploration are fundamental behaviours for survival and are found to be dysfunctional in several psychiatric disorders. Recent studies suggest that the endocannabinoid (eCB) system is an important control system for investigatory drive. Pharmacological treatment of rodents with cannabinergic drugs results in altered social and object investigation. Interestingly, contradictory results have been obtained, depending on the treatment, drug concentration and experimental conditions. The cannabinoid type 1 (CB1) receptor, a central component of the eCB system, is predominantly found at the synapses of two opposing neuronal populations, i.e. on inhibitory GABAerg…

Degenerative and regenerative processes involved in midgut pseudotumor formation in the stick insect (Carausius morosus)

2009

Spontaneous and experimentally induced pseudotumor formation in Carausius morosus impairs the midgut tissue homeostasis. Spontaneous pseudotumor formation begins by the break down of a single or a small group of columnar cells (CCs) and is followed by the degeneration of neighboring CCs. There are not only marked similarities but also decisive differences between normal dying CCs in healthy specimens and the degeneration of CCs leading to pseudotumors: in both cases, the apical cell parts with the nucleus are extruded into the midgut lumen, but only during of pseudotumor formation an "amorphous substance" originates from the basal parts of the CCs. Hemocytes are attracted to this substance …

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…

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…