Search results for "homeostasi"

RELATIONSHIP BETWEEN GONADAL HOMEOSTASIS AND METABOLIC PARAMETERS IN A POPULATION OF HOSPITALIZED DIABETIC MALES.

2015

Serine in plants: biosynthesis, metabolism, and functions

2014

Serine (Ser) has a fundamental role in metabolism and signaling in living organisms. In plants, the existence of different pathways of Ser biosynthesis has complicated our understanding of this amino acid homeostasis. The photorespiratory glycolate pathway has been considered to be of major importance, whereas the nonphotorespiratory phosphorylated pathway has been relatively neglected. Recent advances indicate that the phosphorylated pathway has an important function in plant metabolism and development. Plants deficient in this pathway display developmental defects in embryos, male gametophytes, and roots. We propose that the phosphorylated pathway is more important than was initially thou…

Autoregulation of NFATc1/A Expression Facilitates Effector T Cells to Escape from Rapid Apoptosis

2002

AbstractThreshold levels of individual NFAT factors appear to be critical for apoptosis induction in effector T cells. In these cells, the short isoform A of NFATc1 is induced to high levels due to the autoregulation of the NFATc1 promoter P1 by NFATs. P1 is located within a CpG island in front of exon 1, represents a DNase I hypersensitive chromatin site, and harbors several sites for binding of inducible transcription factors, including a tandemly arranged NFAT site. A second promoter, P2, before exon 2, is not controlled by NFATs and directs synthesis of the longer NFATc1/B+C isoforms. Contrary to other NFATs, NFATc1/A is unable to promote apoptosis, suggesting that NFATc1/A enhances eff…

Current insights into neutrophil homeostasis

2012

Neutrophil granulocytes represent the first immunologic barrier against invading pathogens, and neutropenia predisposes to infection. However, neutrophils may also cause significant collateral inflammatory damage. Therefore, neutrophil numbers are tightly regulated by an incompletely understood homeostatic feedback loop adjusting the marrow's supply to peripheral needs. Granulocyte colony-stimulating factor (G-CSF) is accepted to be the major determinant of neutrophil production, and G-CSF levels have, soon after its discovery, been described to be inversely correlated with neutrophil counts. A neutrophil sensor, or "neutrostat," has, therefore, been postulated. The prevailing feedback hypo…

Mutations in SLC20A2 link familial idiopathic basal ganglia calcification with phosphate homeostasis.

2012

Familial idiopathic basal ganglia calcification (IBGC) is a genetic condition with a wide spectrum of neuropsychiatric symptoms, including parkinsonism and dementia. Here, we identified mutations in SLC20A2, encoding the type III sodium-dependent phosphate transporter 2 (PiT2), in IBGC-affected families of varied ancestry, and we observed significantly impaired phosphate transport activity for all assayed PiT2 mutants in Xenopus laevis oocytes. Our results implicate altered phosphate homeostasis in the etiology of IBGC.

Cholesterol and Amyloid-β: Evidence for a Cross-Talk between Astrocytes and Neuronal Cells.

2011

Accumulating data supports the concept that alterations of cholesterol metabolism might influence the development of Alzheimer's disease (AD), a neurodegenerative disorder characterized by progressive accumulation of amyloid-β (Aβ) peptides in the brain. Changes in the neuronal production of Aβ have been described as a function of cholesterol levels, thus suggesting a causal link between cholesterol homeostasis dysregulation and AD pathogenesis. Under physiological conditions, cholesterol uptake in the brain is efficiently prevented by the blood-brain barrier, and mature neurons are thought to rely on glial cells for their cholesterol supply. In the present study, we tested the hypothesis t…

Liver-specific overexpression of matrix metalloproteinase 9 (MMP-9) in transgenic mice accelerates development of hepatocellular carcinoma.

2010

Matrix metalloproteinase-9 (MMP-9) plays a central role in tumor invasion and development of metastases. Expression of MMP-9 had been shown in human hepatocellular carcinomas (HCCs). However, it remained unclear whether MMP-9 could influence development of HCC. In order to address this issue, we generated transgenic mice overexpressing MMP-9 in the liver. In order to avoid embryonic lethality a Cre-lox system was utilized for conditional overexpression of MMP-9 under control of an albumin enhancer and promoter. Induction of MMP-9 overexpression in transgenic mice was achieved by i.v. injection of an adenovirus coding for the Cre recombinase. Initiation of liver carcinogenesis was achieved b…

Impairment of TGF-β signaling in T cells increases susceptibility to experimental autoimmune hepatitis in mice

2002

In autoimmune hepatitis, strong TGF-beta1 expression is found in the inflamed liver. TGF-beta overexpression may be part of a regulatory immune response attempting to suppress autoreactive T cells. To test this hypothesis, we determined whether impairment of TGF-beta signaling in T cells leads to increased susceptibility to experimental autoimmune hepatitis (EAH). Transgenic mice of strain FVB/N were generated expressing a dominant-negative TGF-beta type II receptor in T cells under the control of the human CD2 promoter/locus control region. On induction of EAH, transgenic mice showed markedly increased portal and periportal leukocytic infiltrations with hepatocellular necroses compared wit…

Sciences within European Young Researcher Community272The neuro-cardiac interaction defines an extracellular microdomain required for neurotrophic si…

2016

# 272 The neuro-cardiac interaction defines an extracellular microdomain required for neurotrophic signaling {#article-title-2} Purpose: Sympathetic neurons (SNs) innervate the myocardium with a defined topology that allows physiological modulation of cardiac activity. Limiting amounts of neurotrophins released by cardiac cells control SN viability and myocardial distribution, whose impairment has been described in a number of heart diseases (e.g. myocardial infarction, heart failure). Therefore, the fine control of cardiac innervation is crucial to ensure the physiological sympathetic function. It has been demonstrated that SNs directly interact with cardiomyocytes (CMs). Although it has b…

Drp1 Controls Effective T Cell Immune-Surveillance by Regulating T Cell Migration, Proliferation, and cMyc-Dependent Metabolic Reprogramming

2018

Summary Mitochondria are key players in the regulation of T cell biology by dynamically responding to cell needs, but how these dynamics integrate in T cells is still poorly understood. We show here that the mitochondrial pro-fission protein Drp1 fosters migration and expansion of developing thymocytes both in vitro and in vivo. In addition, we find that Drp1 sustains in vitro clonal expansion and cMyc-dependent metabolic reprogramming upon activation, also regulating effector T cell numbers in vivo. Migration and extravasation defects are also exhibited in Drp1-deficient mature T cells, unveiling its crucial role in controlling both T cell recirculation in secondary lymphoid organs and acc…