Shift in carbon flow and stimulation of amino-acid turnover induced by nitrate and ammonium assimilation in Anacystis nidulans

Planta ◽  
1993 ◽  
Vol 189 (3) ◽  
pp. 461-467 ◽  
Author(s):  
Tomás Coronil ◽  
Catalina Lara ◽  
Miguel G. Guerrero
Keyword(s):  
Amino Acid ◽  
Ammonium Assimilation ◽  
Anacystis Nidulans ◽  
Carbon Flow ◽  
Amino Acid Turnover ◽  
Nitrate And Ammonium Assimilation ◽  
Stimulation Of

scholarly journals Insulin Stimulation of Amino Acid Uptake in Rat Diaphragm

1968 ◽  
Vol 243 (8) ◽  
pp. 1846-1853 ◽  
Author(s):  
L J Elsas ◽  
I Albrecht ◽  
L E Rosenberg
Keyword(s):  
Amino Acid ◽  
Amino Acid Uptake ◽  
Acid Uptake ◽  
Rat Diaphragm ◽  
Insulin Stimulation ◽  
Stimulation Of

scholarly journals PROTEIN SYNTHESIS AND AMINO ACID TURNOVER IN TISSUE CULTURE

1952 ◽  
Vol 196 (1) ◽  
pp. 51-68 ◽  
Author(s):  
H.W. Gerarde ◽  
Marion. Jones ◽  
Theodore. Winnick
Keyword(s):  
Tissue Culture ◽  
Protein Synthesis ◽  
Amino Acid ◽  
Amino Acid Turnover

scholarly journals 15 A novel CD28 humanized mouse model for efficacy assessment of CD28-targeting therapies

2020 ◽  
Vol 8 (Suppl 3) ◽  
pp. A15-A15
Author(s):  
Fabiane Sônego ◽  
Gaelle Martin ◽  
Chloé Beuraud ◽  
Audrey Beringer ◽  
Yacine Cherifi ◽  
...  
Keyword(s):  
T Cells ◽  
Amino Acid ◽  
Mouse Model ◽  
Cytokine Production ◽  
List Type ◽  
Humanized Mouse ◽  
Humanized Mouse Model ◽  
Efficacy Assessment ◽  
Human And Mouse ◽  
Stimulation Of

BackgroundImmuno-intervention through targeting of activating and inhibitory immune checkpoints (ICP), has shown promising results in the clinic over the last years. To facilitate these researches, mouse models expressing humanized ICP instead of their mouse counterparts were developed. Herein, we describe a novel CD28 humanized mouse model (hCD28 model), designed to test compounds targeting human CD28 (hCD28).MethodsHuman and mouse CD28 (mCD28) have different signalling responses, with hCD28 being known for inducing higher levels of pro-inflammatory cytokines upon stimulation with ligands/superagonists. This can be explained by the expression of CD28i, a hCD28 amplifier isoform which is not found in mouse. Additionally, evidences suggested that the different signalling between human and mCD28 relies on one amino acid change in the intracellular domain (ICD).1 Because the hCD28 model was developed to assess hCD28-targeting therapeutics, we decided to keep the expression of both canonical and CD28i isoforms to avoid undermining the biological effects of the testing antibodies. Although keeping the human ICD could favour the evaluation of cytokine production and therefore the safety of the test therapeutics, we decided to keep the mouse ICD to enable a proper interaction of CD28 with its signalling partners, allowing a physiological stimulation of CD28 in efficacy studies.Results hCD28 mice express hCD28 on T cells and the frequency of CD3 T cells is comparable in both WT and hCD28 mice. Stimulation of hCD28 mice-isolated T cells with hCD28 ligands and agonist antibodies resulted in T cell proliferation and cytokine production, suggesting that hCD28 is functional in mouse cells. MC38 uptake rate and kinetic of growth were comparable in WT and hCD28 mice, suggesting no major defect in the immune response in the hCD28 mice. Importantly, splenocytes and tumor draining lymph nodes cells isolated from tumor-bearing hCD28 mice showed higher production of IL-2 and IFN-gamma upon in vitro re-challenged with MC38 when compared to WT cells. Since the frequency of CD3 cells (Treg, CD4+ and CD8+) is comparable to WT mice, this could be explained by the expression of the amplifier CD28i isoform, which is absent in WT mice.ConclusionsThe hCD28 model described here supports the efficacy assessment of hCD28-targeting biologics, enabling PK/PD studies as hCD28 expression levels and pattern are physiological. However, after careful consideration of the CD28 biology, we decided to keep the mouse ICD, although it triggers lower pro-inflammatory cytokine production than CD28 human ICD. As such, this model is not suitable for toxicology/safety studies.ReferencePorciello N, Grazioli P, Campese AF, et al. A non-conserved amino acid variant regulates differential signalling between human and mouse CD28. Nat Commun 2018; 9:1–16.

Transcription and Translation of the Sex Message in the Smut Fungus Ustilago Violacea

1974 ◽  
Vol 16 (1) ◽  
pp. 49-62
Author(s):  
J. E. CUMMINS ◽  
A. W. DAY
Keyword(s):  
Amino Acid ◽  
Dna Replication ◽  
Information Exchange ◽  
Plasma Membranes ◽  
Cellular Protein ◽  
Mating Activity ◽  
Ustilago Violacea ◽  
Protein Levels ◽  
Amino Acid Turnover ◽  
Mating Conditions

In Ustilago violacea conjugation involves a period of courtship followed by the cooperative assembly of a conjugation tube between paired sporidia of opposite mating type. During courtship information is exchanged between the paired sporidia directing transcription and translation of a ‘sex message’. This information exchange is completed even though the plasma membranes and walls of the mating sporidia remain intact until after the sex message has been translated. Once translation is completed the copulatory organelle is assembled. Inhibitor studies show that translation of specific mRNA species (sex message) is essential during the 3-4 h period of courtship prior to assembly and that transcription of this sex message is completed 15-30 min prior to the completion of translation. Amino acid incorporation studies show that even though the cellular protein levels remain constant during courtship there is extensive amino acid turnover as the sporidia adjust to mating conditions. However, an enhancement of amino acid turnover by mating, in contrast to unmixed sporidia, is not detectable. Prototrophic strains continue to synthesize stable RNA during courtship while amino acid auxotrophs discontinue stable RNA synthesis immediately on transfer to mating conditions. Both prototrophs and auxotrophs show extensive RNA turnover during courtship but a specific enhancement of turnover due to mating activity is not detectable from the labelling pattern alone. A round of DNA replication may be completed during courtship but mating activity does not influence the gross pattern of DNA replication in either of the mating types.

Excitatory amino acid receptors in commissural nucleus of the NTS mediate carotid chemoreceptor responses

1993 ◽  
Vol 264 (1) ◽  
pp. R41-R50 ◽  
Author(s):  
A. Vardhan ◽  
A. Kachroo ◽  
H. N. Sapru
Keyword(s):  
Amino Acid ◽  
Carotid Body ◽  
Excitatory Amino Acid ◽  
Minute Ventilation ◽  
Neuronal Cell ◽  
Excitatory Amino Acid Receptors ◽  
Amino Acid Receptors ◽  
Neuronal Cell Bodies ◽  
Carotid Body Chemoreceptors ◽  
Stimulation Of

Stimulation of carotid body chemoreceptors by saline saturated with 100% CO2 elicited an increase in mean arterial pressure, respiratory rate, tidal volume, and minute ventilation (VE). Microinjections of L-glutamate into a midline area 0.5-0.75 mm caudal and 0.3-0.5 mm deep with respect to the calamus scriptorius increased VE. Histological examination showed that the site was located in the commissural nucleus of the nucleus tractus solitarii (NTS). The presence of excitatory amino acid receptors [N-methyl-D-aspartic acid (NMDA); kainate, quisqualate/alpha-amino-3-hydroxy-5-methyl-4-isoxazole-propionic acid (AMPA) and trans 1-amino-cyclopentane-trans-1,3-dicarboxylic acid (ACPD)] in this area was demonstrated by microinjections of appropriate agonists. Simultaneous blockade of NMDA and non-NMDA receptors by combined injections of DL-2-aminophosphonoheptanoate (AP-7; 1 nmol) and 6,7-dinitro-quinoxaline-2,3-dione (DNQX; 1 nmol) abolished the responses to stimulation of carotid body on either side. Combined injections of AP-7 and DNQX did not produce a nonspecific depression of neurons because the responses to another agonist, carbachol, remained unaltered. Inhibition of the neurons in the aforementioned area with microinjections of muscimol (which hyperpolarizes neuronal cell bodies but not fibers of passage) also abolished the responses to subsequent carotid body stimulation on either side.(ABSTRACT TRUNCATED AT 250 WORDS)

Excitatory amino acid receptors within NTS mediate arterial chemoreceptor reflexes in rats

1993 ◽  
Vol 265 (2) ◽  
pp. H770-H773 ◽  
Author(s):  
W. Zhang ◽  
S. W. Mifflin
Keyword(s):  
Electrical Stimulation ◽  
Amino Acid ◽  
Receptor Antagonist ◽  
Carotid Body ◽  
Excitatory Amino Acid ◽  
Pressor Responses ◽  
Carotid Body Chemoreceptors ◽  
Arterial Chemoreceptor ◽  
Stimulation Of ◽  
Arterial Baroreceptor

The nucleus tractus solitarius (NTS) is the primary site of termination of arterial baroreceptor and chemoreceptor afferent fibers. Excitatory amino acid (EAA) receptors within NTS have been shown to play an important role in the mediation of arterial baroreceptor reflexes; however, the importance of EAA receptors within NTS in the mediation of arterial chemoreceptor reflexes remains controversial. Therefore, in chloralose-urethan-anesthetized, mechanically ventilated, paralyzed rats, 4 nmol of the broad-spectrum EAA receptor antagonist kynurenic acid (Kyn) was injected into the NTS to observe the effects of EAA receptor blockade on the pressor responses evoked by either activation of ipsilateral carotid body chemoreceptors (by close arterial injection of CO2-saturated bicarbonate) or electrical stimulation of ipsilateral carotid sinus nerve (CSN). Under control conditions, activation of carotid body chemoreceptors and CSN stimulation evoked increases in arterial pressure of 27 +/- 2 (n = 24 sites) and 28 +/- 3% (n = 8), respectively. Kyn microinjection into NTS significantly reduced the pressor responses evoked by activation of carotid body chemoreceptors and electrical stimulation of the CSN for 20 and 25 min, respectively. Attenuation of pressor responses evoked by chemoreceptor activation were maximal at 20 min post-Kyn injection (13 +/- 2%), whereas CSN-evoked pressor responses were maximally attenuated at 15 min (6 +/- 4%). Microinjection into NTS of 4 nmol of xanthurenic acid, a structural analogue of Kyn with no EAA receptor antagonist properties, had no effect on chemoreceptor reflexes. We conclude that EAA receptors within NTS play an important role in the mediation of arterial chemoreceptor reflexes.

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