scholarly journals Nitration of cathepsin D enhances its proteolytic activity during mammary gland remodelling after lactation

2009 ◽  
Vol 419 (2) ◽  
pp. 279-288 ◽  
Author(s):  
Rosa Zaragozá ◽  
Luis Torres ◽  
Concha García ◽  
Pilar Eroles ◽  
Fernando Corrales ◽  
...  
Keyword(s):  
Mammary Gland ◽  
Proteolytic Activity ◽  
Cathepsin D ◽  
Specific Activity ◽  
The Novel ◽  
Protein Levels ◽  
Low Concentrations ◽  
Lactating Mammary Gland ◽  
Oxide Synthase

Proteomic studies in the mammary gland of control lactating and weaned rats have shown that there is an increased pattern of nitrated proteins during weaning when compared with controls. Here we report the novel finding that cathepsin D is nitrated during weaning. The expression and protein levels of this enzyme are increased after 8 h of litter removal and this up-regulation declines 5 days after weaning. However, there is a marked delay in cathepsin D activity since it does not increase until 2 days post-weaning and remains high thereafter. In order to find out whether nitration of cathepsin D regulates its activity, iNOS (inducible nitric oxide synthase)−/− mice were used. The expression and protein levels of this enzyme were similar to WT (wild-type) animals, but the proteolytic activity was significantly reduced during weaning in knockout compared to WT mice. in vitro treatment of recombinant human cathepsin D or lactating mammary gland homogenates with relatively low concentrations of peroxynitrite enhances the nitration as well as specific activity of this enzyme. Using MS, it has been shown that the residue Tyr168 was nitrated. All of these results show that protein nitration during weaning might be a signalling pathway involved in mammary gland remodelling.

scholarly journals Weaning induces NOS-2 expression through NF-κB modulation in the lactating mammary gland: importance of GSH

2005 ◽  
Vol 391 (3) ◽  
pp. 581-588 ◽  
Author(s):  
Rosa Zaragozá ◽  
Vicente J. Miralles ◽  
A. Diana Rus ◽  
Concha García ◽  
Rafael Carmena ◽  
...  
Keyword(s):  
Mammary Gland ◽  
Nuclear Translocation ◽  
Nuclear Factor Κb ◽  
Secretory Cells ◽  
No Production ◽  
Tissue Remodelling ◽  
Protein Levels ◽  
Lactating Mammary Gland ◽  
Oxide Synthase

At the end of lactation the mammary gland undergoes involution, a process characterized by apoptosis of secretory cells and tissue remodelling. To gain insight into this process, we analysed the gene expression profile by oligonucleotide microarrays during lactation and after forced weaning. Up-regulation of inflammatory mediators and acute-phase response genes during weaning was found. Expression of IκBα (inhibitory κBα), a protein known to modulate NF-κB (nuclear factor-κB) nuclear translocation, was significantly up-regulated. On the other hand, there was a time-dependent degradation of IκBα protein levels in response to weaning, suggesting a role for NF-κB. Furthermore, we have demonstrated, using chromatin immunoprecipitation assays, binding of NF-κB to the NOS-2 (inducible nitric oxide synthase) promoter at the early onset of events triggered during weaning. The three isoforms of NOS are constitutively present in the lactating mammary gland; however, while NOS-2 mRNA and protein levels and, consequently, NO production are increased during weaning, NOS-3 protein levels are diminished. Western blot analyses have demonstrated that protein nitration is increased in the mammary gland during weaning, but this is limited to a few specific tyrosine-nitrated proteins. Interestingly, inhibition of GSH synthesis at the peak of lactation partially mimics these findings, highlighting the role of NO production and GSH depletion during involution.

scholarly journals Remineralization of enamel caries by an amelogenin-derived peptide and fluoride in vitro

2020 ◽  
Vol 7 (3) ◽  
pp. 283-292 ◽  
Author(s):  
Longjiang Ding ◽  
Sili Han ◽  
Kun Wang ◽  
Sainan Zheng ◽  
Wenyue Zheng ◽  
...  
Keyword(s):  
Tooth Enamel ◽  
The Novel ◽  
Oral Diseases ◽  
Surface Microhardness ◽  
Enamel Caries ◽  
Low Concentrations ◽  
The World ◽  
Mineral Loss ◽  
Hydroxyapatite Crystals

Abstract Dental caries is one of the most common oral diseases in the world. This study was tantamount to investigate the combinatory effects of an amelogenin-derived peptide (called QP5) and fluoride on the remineralization of artificial enamel caries. The peptide QP5 was synthesized and characterized, and the binding capability of the peptide on hydroxyapatite (HA) and demineralized tooth enamel surface was analysed. Then, the mineralization function of the peptide and fluoride was studied through the spontaneous mineralization testing and remineralization on enamel caries in vitro. First, the novel peptide QP5 could bind on the hydroxyapatite and demineralized tooth enamel surfaces. Second, QP5 can transitorily stabilize the formation of amorphous calcium phosphate and direct the transformation into hydroxyapatite crystals alone and in combination with fluoride. In addition, compared to blocks treated by peptide QP5 alone or fluoride, the sample blocks showed significantly higher surface microhardness, lower mineral loss and shallower lesion depth after treatment with a combination of QP5 and fluoride at high or low concentrations. The peptide QP5 could control the crystallization of hydroxyapatite, and combinatory application of peptide QP5 and fluoride had a potential synergistic effect on the remineralization of enamel caries.

A distal region, hypersensitive to DNase I, plays a key role in regulating rabbit whey acidic protein gene expression

2001 ◽  
Vol 359 (3) ◽  
pp. 557-565 ◽  
Author(s):  
Benjamin MILLOT ◽  
Marie-Louise FONTAINE ◽  
Dominique THEPOT ◽  
Eve DEVINOY
Keyword(s):  
Mammary Gland ◽  
Sequence Similarity ◽  
Distal Region ◽  
Dnase I ◽  
Whey Acidic Protein ◽  
Acidic Protein ◽  
Upstream Region ◽  
Lactating Mammary Gland

The aim of the present study was to identify the functional domains of the upstream region of the rabbit whey acidic protein (WAP) gene, which has been used with considerable efficacy to target the expression of several foreign genes to the mammary gland. We have shown that this region exhibits three sites hypersensitive to DNase I digestion in the lactating mammary gland, and that all three sites harbour elements which can bind to Stat5 in vitro in bandshift assays. However, not all hypersensitive regions are detected at all stages from pregnancy to weaning, and the level of activated Stat5 detected in the rabbit mammary gland is low except during lactation. We have studied the role of the distal site, which is only detected during lactation, in further detail. It is located within a 849bp region that is required to induce a strong expression of the chloramphenicol acetyltransferase reporter gene in transfected mammary cells. Taken together, these results suggest that this region, centred around a Stat5-binding site and surrounded by a variable chromatin structure during the pregnancy–lactation cycle, may play a key role in regulating the expression of this gene in vivo. Furthermore, this distal region exhibits sequence similarity with a region located around 3kb upstream of the mouse WAP gene. The existence of such a distal region in the mouse WAP gene may explain the differences in expression between 4.1 and 2.1kb mouse WAP constructs.

scholarly journals Antimalarial 9-Anilinoacridine Compounds Directed at Hematin

2003 ◽  
Vol 47 (12) ◽  
pp. 3708-3712 ◽  
Author(s):  
Saranya Auparakkitanon ◽  
Wilai Noonpakdee ◽  
Raymond K. Ralph ◽  
William A. Denny ◽  
Prapon Wilairat
Keyword(s):  
Topoisomerase Ii ◽  
Rapid Onset ◽  
Stoichiometric Ratio ◽  
The Novel ◽  
Dna Topoisomerase Ii ◽  
Dna Topoisomerase ◽  
Molar Ratios ◽  
Low Concentrations ◽  
Absorbance Changes

ABSTRACT Antimalarial 9-anilinoacridines are potent inhibitors of parasite DNA topoisomerase II both in vitro and in situ. 3,6-Diamino substitution on the acridine ring greatly improves parasiticidal activity against Plasmodium falciparum by targeting DNA topoisomerase II. A series of 9-anilinoacridines were investigated for their abilities to inhibitβ -hematin formation, to form drug-hematin complexes, and to enhance hematin-induced lysis of red blood cells. Inhibition ofβ -hematin formation was minimal with 3,6-diamino analogs of 9-anilinoacridine and greatest with analogs with a 3,6-diCl substitution together with an electron-donating group in the 1′-anilino position. On the other hand, the presence of a 1′-N(CH3)2 group in the anilino ring produced compounds that strongly inhibited β-hematin formation but which did not appear to be sensitive to the nature of the substitutions in the acridine nucleus. The derivatives bound hematin, and Job's plots of UV-visible absorbance changes in drug-hematin complexes at various molar ratios indicated a stoichiometric ratio of 1:2. The drugs enhanced hematin-induced red blood cell lysis at low concentrations (<4 μM). These studies open up the novel possibility of development of 9-anilinoacridine antimalarials that target not only DNA topoisomerase II but alsoβ -hematin formation, which should help delay the rapid onset of resistance to drugs acting at only a single site.

scholarly journals Oestradiol enhances apoptosis in bovine mammary epithelial cells in vitro

2012 ◽  
Vol 80 (1) ◽  
pp. 113-121 ◽  
Author(s):  
Lucile Yart ◽  
Laurence Finot ◽  
Vanessa Lollivier ◽  
Frederic Dessauge
Keyword(s):  
Mammary Gland ◽  
Milk Production ◽  
Mammary Epithelial Cell ◽  
Mammary Epithelial Cells ◽  
Major Effect ◽  
Mammary Epithelial ◽  
Bovine Mammary Epithelial Cells ◽  
Lactating Mammary Gland ◽  
Negative Effect

Ovarian steroids, oestradiol and progesterone, are required for normal mammary growth at puberty and during pregnancy. They contribute to mammary parenchyma development by stimulating mammary epithelial cell (MEC) proliferation. However several studies demonstrate that oestradiol negatively affects milk production during the declining phase of lactation, but the oestradiol effect on MEC in lactating mammary gland remains unclear. The objective of this study was to investigate the differential effect of oestradiol on bovine MECs mimicking two physiological statuses: active and early apoptotic MECs. We demonstrated that oestradiol has a major effect on early apoptotic MECs and might accelerate MEC apoptosis by activation of caspases rather than by inducing apoptosis in active MECs. Early apoptotic MECs could be compared with senescent cells in the late-lactation mammary gland. These results suggest that the negative effect of oestradiol on milk production during the declining phase of lactation would be due to an enhancement of apoptotic processes in MECs.

Metabolic syndrome increases endogenous carbon monoxide production to promote hypertension and endothelial dysfunction in obese Zucker rats

2006 ◽  
Vol 290 (3) ◽  
pp. R601-R608 ◽  
Author(s):  
Fruzsina K. Johnson ◽  
Robert A. Johnson ◽  
William Durante ◽  
Keith E. Jackson ◽  
Blake K. Stevenson ◽  
...  
Keyword(s):  
Metabolic Syndrome ◽  
Carbon Monoxide ◽  
Endothelial Dysfunction ◽  
Ldl Cholesterol ◽  
Oxidized Ldl ◽  
Zucker Rats ◽  
Protein Levels ◽  
Obese Zucker Rats ◽  
Oxide Synthase

Vascular heme oxygenase (HO) metabolizes heme to form carbon monoxide (CO). Increased heme-derived CO inhibits nitric oxide synthase and can contribute to hypertension via endothelial dysfunction in Dahl salt-sensitive rats. Obese Zucker rats (ZR) are models of metabolic syndrome. This study tests the hypothesis that endogenous CO formation is increased and contributes to hypertension and endothelial dysfunction in obese ZR. Awake obese ZR showed increased respiratory CO excretion, which was lowered by HO inhibitor administration [zinc deuteroporphyrin 2,4-bis glycol (ZnDPBG) 25 μmol·kg−1·24 h−1 ip]. In awake obese ZR, chronically instrumented with femoral arterial catheters, blood pressure was elevated but was decreased by the HO inhibitor ZnDPBG. Body weight, blood glucose, glycated hemoglobin, plasma insulin, total and LDL cholesterol, oxidized LDL, and triglyceride levels were elevated in obese ZR, and, except for LDL cholesterol, were unchanged by HO inhibition. Total HO-1 protein levels were not different between lean and obese ZR aortas. In vitro experiments used isolated skeletal muscle arterioles with constant pressure and no flow, or constant midpoint, but altered endpoint pressures to establish graded levels of luminal flow. In obese ZR arterioles, responses to ACh and flow were attenuated. Acute in vitro pretreatment with an HO inhibitor, chromium mesoporphyrin, enhanced ACh and flow-induced dilation and abolished the differences between groups. Furthermore, exogenous CO prevented the restoration of flow-induced dilation by the HO inhibitor in obese ZR arterioles. These results suggest that HO-derived CO production is increased and promotes hypertension and arteriolar endothelial dysfunction in obese ZR with metabolic syndrome independent of affecting metabolic parameters.

O34. Potent and highly selective inhibition of the inducible nitric oxide synthase in vitro and in vivo by the novel imidazopyridine BYK191023

Nitric Oxide ◽  
2006 ◽  
Vol 14 (4) ◽  
pp. 11
Author(s):  
Andreas Strub ◽  
Christian Hesslinger ◽  
Martin D. Lehner ◽  
Wolf-Rüdiger Ulrich ◽  
Manfrid Eltze ◽  
...  
Keyword(s):  
Nitric Oxide ◽  
Nitric Oxide Synthase ◽  
Inducible Nitric Oxide Synthase ◽  
Selective Inhibition ◽  
The Novel ◽  
Oxide Synthase ◽  
Inducible Nitric Oxide

scholarly journals Decreased lactation capacity and altered milk composition in insulin receptor substrate null mice is associated with decreased maternal body mass and reduced insulin-dependent phosphorylation of mammary Akt

2007 ◽  
Vol 194 (2) ◽  
pp. 327-336 ◽  
Author(s):  
Darryl L Hadsell ◽  
Walter Olea ◽  
Nicole Lawrence ◽  
Jessy George ◽  
Daniel Torres ◽  
...  
Keyword(s):  
Mammary Gland ◽  
Insulin Receptor ◽  
Post Partum ◽  
Milk Composition ◽  
Maternal Body ◽  
Akt Phosphorylation ◽  
Protein Levels ◽  
Insulin Receptor Substrates ◽  
Lactating Mammary Gland ◽  
Insulin Dependent

Expression of insulin receptor substrates (IRS)-1 and -2 within the mammary gland was found to be high at mid-lactation and dramatically decreased with mammary involution. This observation supports the hypothesis that these proteins are induced in the mammary gland with lactogenesis and involved in normal milk synthesis. To test this hypothesis, lactation capacity, along with indices of mammary secretory cell glucose metabolism and cell signaling were compared in normal mice and mice carrying targeted mutations in either the Irs1 or Irs2 genes. Mammary IRS-1 and IRS-2 protein levels were increased within 1 day of parturition and reached maximal levels by 5 days post partum. Dams carrying germline mutations of Irs1 or Irs2 displayed reduced lactation capacity as assessed by weight gain of pup litters. The reduction was more dramatic in Irs1−/− versus Irs2−/− dams. Maternal body weight was also reduced in Irs1−/− dams as well as in Irs1+/− Irs2+/− dams. The loss of IRS-1 had little impact on mammary gland expression of milk protein mRNAs, glucose transport, or on the abundance and subcellular localization of hexokinases I and II. The loss of IRS-1 was associated with a compensatory increase in insulin-induced IRS-2 phosphorylation; however, the loss of IRS-1 did also cause a reduction in insulin-dependent mammary gland-specific activation of Akt phosphorylation. These results support the conclusion that IRS-1 is important for insulin-dependent activation of Akt signaling within the lactating mammary gland, but that loss of this protein has only modest impact on normal milk synthesis, since related signaling proteins such as IRS-2 may act in compensatory fashion.

scholarly journals The regulation of lipogenesis in vivo in the lactating mammary gland of the rat during the starved-refed transition. Studies wtih acarbose, a glucosidase inhibitor

1987 ◽  
Vol 242 (1) ◽  
pp. 235-243 ◽  
Author(s):  
S W Mercer ◽  
D H Williamson
Keyword(s):  
Mammary Gland ◽  
Time Course ◽  
Chow Diet ◽  
Glucosidase Inhibitor ◽  
Lactating Mammary Gland ◽  
Phosphofructokinase Activity ◽  
Time Course Study ◽  
Fructose 1,6 Bisphosphate

Depression of carbohydrate digestion by oral administration of acarbose, a glucosidase inhibitor, led to a 75% inhibition of the re-activation of lipogenesis in vivo in the mammary gland of 18 h-starved lactating rats refed with 5 g of chow diet. Rates of [1-14C]glucose incorporation in vitro into lipid and CO2 in mammary-gland acini isolated from refed animals were elevated compared with acini from starved rats, but acarbose treatment completely prevented this stimulation. Gastric intubation of glucose led to a large stimulation of lipogenesis in the mammary gland of starved lactating rats, similar to that induced by refeeding with chow diet; this was dependent on the amount of glucose given and the time elapsed between glucose administration and injection of 3H2O for the measurement of lipogenesis. The switch-on of lipogenesis in the mammary gland of starved lactating rats, by refeeding or by intubation of glucose, was associated with a decrease in the ratio of [glucose 6-phosphate]/[fructose 1,6-bisphosphate] in the gland, indicative of an increase in phosphofructokinase activity. A time-course study revealed that the ratio decreased rapidly over the first 30 min of chow refeeding, after which a large surge in lipogenesis was seen. Acarbose, given 25 min after the onset of refeeding, led to a stepwise increase in the ratio, in parallel with the observed decrease in lipogenic activity. It is concluded that the control of lipogenesis in the mammary gland is closely linked to the availability of dietary carbohydrate. An important site of regulation of lipogenesis in the gland appears to be at the level of phosphofructokinase. A possible role of insulin in the regulation of phosphofructokinase activity, and the acute modulation of insulin-sensitivity in the gland during the starved-refed transition, are discussed.

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