Homeostasis

Hepcidin (H25) is a hormone peptide synthesized by the liver that binds to ferroportin and blocks iron export. In this study, H25 was inhibited by administration of single and multiple doses of an anti-H25 monoclonal antibody Ab 12B9m in cynomolgus monkeys. The objective of this analysis was to develop a pharmacodynamic model describing the role of H25 in regulating iron homeostasis and the impact of hepcidin inhibition by Ab 12B9m. Total serum H25 and Ab 12B9m were determined in each animal. Corresponding measurements of serum iron and hemoglobin (Hb) were obtained.

15p caothientrangnguyen 09-05-2020 12 1   Download

Polyphosphate polymer (polyP) plays a very important role in every living cell. Synthesis of this linear polymer of phosphate (Pi) residues is catalyzed by the polyphosphate kinase (PPK) enzyme.

16p nutifooddau 27-01-2019 17 2   Download

Intracellular pH homeostasis in the filamentous fungus Aspergillus niger was measured in real time by 31P NMR during perfusion in the NMR tube of fungal biomass immobilized in Ca2+-alginate beads. The fungus maintained constant cytoplasmic pH (pHcyt) and vacuolar pH (pHvac) values of 7.6 and 6.2, respectively, when the extracellular pH (pHex) was varied between 1.5 and 7.0 in the presence of citrate. Intracellular metabolism did not collapse until a DpH over the cytoplasmic membrane of 6.6–6.7 was reached (pHex 0.7–0.8).

10p research12 01-06-2013 41 4   Download

Insulin is the principal regulatory hormone involved in the tight regulation of fuel metabolism. In response to blood glucose levels, it is secreted by the b cells of the pancreas and exerts its effects by binding to cell surface receptors that are present on virtually all cell types and tissues. In humans, perturbations in insulin function and/or secretion lead to diabetes mellitus, a severe disorder primarily characterized by an inability to maintain blood glucose homeostasis. Furthermore, it is estimated that 90–95% of diabetic patients exhibit resistance to insulin action....

10p research12 01-06-2013 34 4   Download

When studiedin vitro, mitochondrial permeability transition (MPT) is associated with an increase in mitochondrial per-meability to solutes up to 1500 Da in mass and a loss of electrical potential difference across the inner mitochondrial membrane (Dwmit). The MPT has been implicated as being important in cellular calcium homeostasis, autophagy and cell death via necrosis and apoptosis.

8p research12 23-04-2013 47 3   Download

To sustain life mammals have an absolute and continual requirement for oxygen, which is necessary to produce energy for normal cell survival and growth. Hence, main-tainingoxygen homeostasis is a critical requirement and mammals have evolved a wide range of cellular and phy-siological responses to adapt to changes in oxygen avail-ability. In the past few years it has become evident that the transcriptional protein complex hypoxia-inducible factor (HIF) is a key regulator of these processes.

10p tumor12 20-04-2013 35 4   Download

The development of targeted probes (based on the molecular engineering of luminescent or fluorescent proteins) has allowed the specific measure-ment of [Ca 2+ ] in intracellular organelles or cytoplasmic subdomains. This approach gave novel information on different aspects of cellular Ca 2+ homeostasis. Regarding mitochondria, it was possible to demonstrate that, upon physiological stimulation of cells, Ca 2+ is rapidly accumulated in the matrix.

10p fptmusic 11-04-2013 41 2   Download

The budding yeastSaccharomyces cerevisiaepossesses a very flexible and complex programme of gene expression when exposed to a plethora of environmental insults. Therefore, yeast cell homeostasis control is achieved through a highly coordinated mechanism of transcription regulation invol-ving several factors, each performing specific functions. Here, we present our current knowledge of the function of the yeast activator protein family, formed by eight basic-leucine zipper trans-activators, which have been shown to play an important role in stress response....

0p awards 06-04-2013 52 2   Download

Adaptations of the kinetic properties of mitochondria in striated muscle lacking cytosolic (M) and⁄or mitochondrial (Mi) creatine kinase (CK) iso-forms in comparison to wild-type (WT) were investigated in vitro. Intact mitochondria were isolated from heart and gastrocnemius muscle of WT and single- and double CK-knock-out mice strains (cytosolic (M-CK –⁄ – ), mitochondrial (Mi-CK –⁄ – ) and double knock-out (MiM-CK –⁄ – ), respect-ively).

10p awards 05-04-2013 40 5   Download

Three pairs of parental (q + ) and established mitochondrial DNAdepleted (q 0 ) cells, derived frombone, lungandmuscle were used to verify the influence of the nuclear background and the lack of efficient mitochondrial respiratory chain on antioxidant defences and homeostasis of intracellular reactive oxygen species (ROS).

11p awards 05-04-2013 45 4   Download

The regulation of adenosine kinase (AK) activity has the potential to control intracellular and interstitial adenosine (Ado) concentrations. In an effort to study the role of AK in Ado homeostasis in the central nervous system, two iso-forms of the enzymewere cloned fromamouse brain cDNA library. Following overexpression in bacterial cells, the cor-responding proteins were purified to homogeneity.

9p awards 05-04-2013 37 2   Download

Metallothioneins are typically low relative molecular mass (6000–7000), sulfhydryl-rich metal-binding proteins with characteristic repeating cysteine motifs (Cys-X-Cys or Cys-Xn-Cys) and a prolate ellipsoid shape containing single a-andb-domains. While functionally diverse, they play important roles in the homeostasis, detoxification and stress response of metals. The originally reported metallothionein of the American oyster,Crassostrea virginicashowed the canonical molluscanab-domain structure. ...

11p dell39 03-04-2013 49 5   Download

Spermine oxidase (SMO) is a flavoenzyme involved in polyamine homeostasis in animal cells. Themouse spermine oxidasegene (mSMO) codes for splicevariants, including the previously reportedmajor active isoform, herein named alfa (a). In the present work, eight additional gene splicing variants were characterized. The heterologous expression and biochemical characterization ofthree recombinant iso-forms (namely mSMOl,-cand -d) revealed that only the recombinant protein mSMOldisplays biochemical charac-...

11p dell39 03-04-2013 41 5   Download

Estrogen is known to influence glucose homeostasis but the role of estrogen receptors in muscle glucose metabolism is unknown. Therefore, we investigated the expression of the two estrogen receptors, ERa and ERb and their influence on regulation of GLUT4, and its associated structural protein, caveolin-1, in mouse muscle. ERaand ERbare co-expressed in the nuclei of most muscle cells and their levels were not affected by absence of estradiol (in aromatase knockout, ArKO, mice).

6p inspiron33 26-03-2013 46 4   Download

Polyamine oxidase (PAO) and spermine oxidase (SMO) are involved in the catabolism of polyamines – basic regulators of cell growth and prolifer-ation. The discovery of selective inhibitors of PAO and SMO represents an important tool in studying the involvement of these enzymes in polyamine homeostasis and a starting point for the development of novel antineoplas-tic drugs.

9p inspiron33 26-03-2013 41 5   Download

The discovery of iron-responsive elements (IREs), along with the identifica-tion of iron regulatory proteins (IRP1, IRP2), has provided a molecular basis for our current understanding of the remarkable post-transcriptional regulation of intracellular iron homeostasis. In iron-depleted conditions, IRPs bind to IREs present in the 5¢-UTR of ferritin mRNA and the 3¢-UTR of transferrin receptor (TfR) mRNA.

9p inspiron33 25-03-2013 41 3   Download

Hemopexin (HPX), which serves as a scavenger and transporter of toxic plasma heme, has been postulated to play a key role in the homeostasis of NO. In fact, HPX–heme(II) reversibly binds NO and facilitates NO scaven-ging by O2. HPX–heme is formed by two four-bladed b-propeller domains. The heme is bound between the twob-propeller domains, residues His213 and His266 coordinate the heme iron atom.

12p inspiron33 23-03-2013 43 5   Download

Intracellular heme concentrations are maintained in part by heme degrada-tion, which is catalyzed by heme oxygenase. Heme oxygenase consists of two structurally related isozymes, HO-1 and HO-2. Recent studies have identified HO-2 as a potential oxygen sensor. To gain further insights into the regulatory role of HO-2 in heme homeostasis, we analyzed the expres-sion profiles of HO-2 and the biochemical consequences of HO-2 knock-down with specific short interfering RNA (siRNA) in human cells.

14p inspiron33 23-03-2013 32 4   Download

The activation of ADAMTS (a disintegrin and metalloprotease with thrombospondin motifs) family proteases depends on removal of the prodomain. Although several studies suggest that ADAMTS activities play roles in development, homeostasis and disease, it remains unclear when and where the enzymes are activated in vivo.

10p galaxyss3 07-03-2013 35 5   Download

A dominant negative form of p63,DNp63a, is critical for maintaining the proliferative potential of epidermal stem cells and progenitor cells. The expression ofDNp63aalso confers a selective advantage for cancer cell survival, underscoring the importance of DNp63a in both normal and neoplastic stratified epithelia.

12p media19 05-03-2013 24 1   Download