scholarly journals Paradoxical Regulation of Biotin Utilization in Brain and Liver and Implications for Inherited Multiple Carboxylase Deficiency

2004 ◽  
Vol 279 (50) ◽  
pp. 52312-52318 ◽  
Author(s):  
Diana Pacheco-Alvarez ◽  
R. Sergio Solórzano-Vargas ◽  
Roy A. Gravel ◽  
Rafael Cervantes-Roldán ◽  
Antonio Velázquez ◽  
...  

Holocarboxylase synthetase (HCS) catalyzes the biotinylation of five carboxylases in human cells, and mutations of HCS cause multiple carboxylase deficiency (MCD). Although HCS also participates in the regulation of its own mRNA levels, the relevance of this mechanism to normal metabolism or to the MCD phenotype is not known. In this study, we show that mRNA levels of enzymes involved in biotin utilization, including HCS, are down-regulated during biotin deficiency in liver while remaining constitutively expressed in brain. We propose that this mechanism of regulation is aimed at sparing the essential function of biotin in the brain at the expense of organs such as liver and kidney during biotin deprivation. In MCD, it is possible that some of the manifestations of the disease may be associated with down-regulation of biotin utilization in liver because of the impaired activity of HCS and that high dose biotin therapy may in part be important to overcoming the adverse regulatory impact in such organs.

2005 ◽  
Vol 289 (6) ◽  
pp. R1763-R1769 ◽  
Author(s):  
Mikhiela Sherrod ◽  
Deborah R. Davis ◽  
Xizhou Zhou ◽  
Martin D. Cassell ◽  
Curt D. Sigmund

Angiotensinogen (AGT) is mainly expressed in glial cells in close proximity to renin-expressing neurons in the brain. We previously reported that glial-specific overexpression of ANG II results in mild hypertension. Here, we tested the hypothesis that glial-derived AGT plays an important role in blood pressure regulation in hypertensive mice carrying human renin (hREN) and human AGT transgenes under the control of their own endogenous promoters. To perform a glial-specific deletion of AGT, we used an AGT transgene containing loxP sites (hAGTflox), so the gene can be permanently ablated in the presence of cre-recombinase expression, driven by the glial fibrillary acidic protein (GFAP) promoter. Triple transgenic mice (RAC) containing a: 1) systemically expressed hREN transgene, 2) systemically expressed hAGTflox transgene, and 3) GFAP-cre-recombinase were generated and compared with double transgenic mice (RA) lacking cre-recombinase. Liver and kidney hAGT mRNA levels were unaltered in RAC and RA mice, as was the level of hAGT in the systemic circulation, consistent with the absence of cre-recombinase expression in those tissues. Whereas hAGT mRNA was present in the brain of RA mice (lacking cre-recombinase), it was absent from the brain of RAC mice expressing cre-recombinase, confirming brain-specific elimination of AGT. Immunohistochemistry revealed a loss of AGT immunostaining glial cells throughout the brain in RAC mice. Arterial pressure measured by radiotelemetry was significantly lower in RAC than RA mice and unchanged from nontransgenic control mice. These data suggest that there is a major contribution of glial-AGT to the hypertensive state in mice carrying systemically expressed hREN and hAGT genes and confirm the importance of a glial source of ANG II substrate in the brain.


Author(s):  
G.A. Miranda ◽  
M.A. Arroyo ◽  
C.A. Lucio ◽  
M. Mongeotti ◽  
S.S. Poolsawat

Exposure to drugs and toxic chemicals, during late pregnancy, is a common occurrence in childbearing women. Some studies have reported that more than 90% of pregnant women use at least 1 prescription; of this, 60% used more than one. Another study indicated that 80% of the consumed drugs were not prescribed, and of this figure, 95% were “over-the-counter” drugs. Acetaminophen, the safest of all over-the-counter drugs, has been reported to induce fetal liver necrosis in man and animals and to have abortifacient and embryocidal action in mice. This study examines the degree to which acetaminophen affects the neonatal liver and kidney, when a fatty diet is simultaneously fed to the mother during late pregnancy.Timed Swiss Webster female mice were gavaged during late pregnancy (days 16-19) with fat suspended acetaminophen at a high dose, HD = 84.50 mg/kg, and a low dose, LD = 42.25 mg/kg; a control group received fat alone.


2019 ◽  
Vol 15 (2) ◽  
pp. 121-129
Author(s):  
Zhi Rao ◽  
Bo-xia Li ◽  
Yong-Wen Jin ◽  
Wen-Kou ◽  
Yan-rong Ma ◽  
...  

Background: Imatinib (IM) is a chemotherapy medication metabolized by CYP3A4 to Ndesmethyl imatinib (NDI), which shows similar pharmacologic activity to the parent drug. Although methods for determination of IM and/or NDI have been developed extensively, only few observations have been addressed to simultaneously determine IM and NDI in biological tissues such as liver, kidney, heart, brain and bone marrow. Methods: A validated LC-MS/MS method was developed for the quantitative determination of imatinib (IM) and N-desmethyl imatinib (NDI) from rat plasma, bone marrow, brain, heart, liver and kidney. The plasma samples were prepared by protein precipitation, and then the separation of the analytes was achieved using an Agilent Zorbax Eclipse Plus C18 column (4.6 × 100 mm, 3.5 µm) with gradient elution running water (A) and methanol (B). Mass spectrometric detection was achieved by a triplequadrupole mass spectrometer equipped with an electrospray source interface in positive ionization mode. Results: This method was used to investigate the pharmacokinetics and the tissue distributions in rats following oral administration of 25 mg/kg of IM. The pharmacokinetic profiles suggested that IM and NDI are disappeared faster in rats than human, and the tissue distribution results showed that IM and NDI had good tissue penetration and distribution, except for the brain. This is the first report about the large penetrations of IM and NDI in rat bone marrow. Conclusion: The method demonstrated good sensitivity, accuracy, precision and recovery in assays of IM and NDI in rats. The described assay was successfully applied for the evaluation of pharmacokinetics and distribution in the brain, heart, liver, kidney and bone marrow of IM and NDI after a single oral administration of IM to rats.


2012 ◽  
Vol 2012 ◽  
pp. 1-12 ◽  
Author(s):  
Giulio Tononi ◽  
Chiara Cirelli

Sleep must serve an essential, universal function, one that offsets the risk of being disconnected from the environment. The synaptic homeostasis hypothesis (SHY) is an attempt to identify this essential function. Its core claim is that sleep is needed to reestablish synaptic homeostasis, which is challenged by the remarkable plasticity of the brain. In other words, sleep is “the price we pay for plasticity.” In this issue, M. G. Frank reviewed several aspects of the hypothesis and raised several issues. The comments below provide a brief summary of the motivations underlying SHY and clarify that SHY is a hypothesis not about specific mechanisms, but about a universal, essential function of sleep. This function is the preservation of synaptic homeostasis in the face of a systematic bias toward a net increase in synaptic strength—a challenge that is posed by learning during adult wake, and by massive synaptogenesis during development.


2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Chi-Wei Chang ◽  
Chuang-Hsin Chiu ◽  
Ming-Hsien Lin ◽  
Hung-Ming Wu ◽  
Tsung-Hsun Yu ◽  
...  

Abstract Background Expression of translocator protein (TSPO) on the outer mitochondrial membrane of activated microglia is strongly associated with neuroinflammation. The second-generation PET ligand [18F]FEPPA specifically binds TSPO to enable in vivo visualization and quantification of neuroinflammation. We optimized a fully automated radiosynthesis method and evaluated the utility of [18F]FEPPA, the second-generation PET ligand specifically binds TSPO, in a mouse model of systemic LPS challenge to detect TSPO-associated signals of central and peripheral inflammation. In vivo dynamic PET/MR imaging was performed in LPS-induced and control mice after [18F]FEPPA administration. The relationship between the [18F]FEPPA signal and the dose of LPS was assessed. The cytokine levels (i.e., TNF-α, Il-1β, Il-6) in LPS-induced mice were measured by RT-PCR. Standard uptake value (SUV), total volume of distribution (VT) and area under the curve (AUC) were determined based on the metabolite-uncorrected plasma input function. Western blotting and immunostaining were used to measure TSPO expression in the brain. Results The fully automated [18F]FEPPA radiosynthesis produced an uncorrected radiochemical yield of 30 ± 2% within 80 min, with a radiochemical purity greater than 99% and specific activity of 148.9‒216.8 GBq/µmol. Significant differences were observed in the brain after [18F]FEPPA administration: SUV, VT and AUC were 1.61 ± 0.1, 1.25 ± 0.12 and 1.58 ± 0.09-fold higher in LPS-injected mice than controls. TNF-α, Il-1β and Il-6 mRNA levels were also elevated in the brains of LPS-injected mice. Western blotting revealed TSPO (p < 0.05) and Iba-1 (p < 0.01) were upregulated in the brain after LPS administration. In LPS-injected mice, TSPO immunoactivity colocalized with Iba-1 in the cerebrum and TSPO was significantly overexpressed in the hippocampus and cerebellum. The peripheral organs (heart, lung) of LPS-injected mice had higher [18F]FEPPA signal-to-noise ratios than control mice. Conclusions Based on the current data on ligand specificity and selectivity in central tissues using 7 T PET/MR imaging, we demonstrate that [18F]FEPPA accumulations significant increased in the specific brain regions of systemic LPS-induced neuroinflammation (5 mg/kg). Future investigations are needed to determine the sensitivity of [18F]FEPPA as a biomarker of neuroinflammation as well as the correlation between the PET signal intensity and the expression levels of TSPO.


2010 ◽  
Vol 104 (9) ◽  
pp. 1297-1303 ◽  
Author(s):  
Yan-Hong Huang ◽  
Qing-Hong Zhang

The present study was undertaken to investigate the antioxidant effect of chronic ingestion of genistein (Gen) against neural death in the brain of ovariectomised (Ovx) rats. The rats were randomly divided into five groups, i.e. sham-operated (sham), Ovx-only, Ovx with 17β-oestradiol, Ovx with low (15 mg/kg) and high (30 mg/kg) doses of Gen (Gen-L and Gen-H), and were orally administered daily with drugs or vehicle for 6 weeks. The learning and memory abilities were measured by Morris water maze test. Oxidative damages in the brain were evaluated by the level of superoxide dismutase (SOD), malondialdehyde (MDA) and monoamine oxidase (MAO) activities. Neural apoptosis was shown by terminal deoxynucleotidyl transferase dUTP nick end labelling (TUNEL) staining and caspase-3 activity. In the visual learning and memory test, there were no significant differences among the population means of the five groups. While in the probe trial test, the Gen-L group instead of the Gen-H group exhibited reduced escape latency and increased memory frequency than the Ovx group. Although both doses of Gen could reduce acetylcholinesterase activity, only a low dose of Gen could diminish MDA activity significantly in frontal cortex and enhance SOD content in the hippocampus. In contrast, MAO content was decreased in the cortex by either dose of Gen, while in the hippocampus, only a high dose of Gen appeared to be effective. Interestingly, Gen at both the doses could attenuate the increased number of TUNEL-positive neurons and caspase-3 activity in Ovx rats. These results suggest that Gen confers protection against Ovx-induced neurodegeneration by attenuating oxidative stress, lipid peroxidation and the mitochondria-mediated apoptotic pathway in a region- and dose-dependent manner.


Author(s):  
Nadežda Berzina ◽  
Jurijs Markovs ◽  
Mirdza Apsīte ◽  
Svetlana Vasiļjeva ◽  
Galina Smirnova ◽  
...  

The effects of ascorbic acid supplementation on biomarkers of oxidative stress, cadmium accumulation in organs, immune system activity and kidney function in chickens were investigated. The treatment groups of chickens were fed either plain diet or diet supplemented with ascorbic acid at 100, 500, 1000 and 2000 mg/kg for four weeks. Liver and kidney tissues were assayed for cadmium concentration, and the hepatic levels of ascorbic acid and dehydroascorbic acid (DHAA; the oxidised form), malondialdehyde, glutathione, activity of glutathione peroxidase, blood serum uric acid, creatinine, lysozyme and circulating immune complexes were measured. Supplementation with a high dose of ascorbic acid (1000 and 2000 mg/kg in the diet) caused an imbalance between pro-oxidative and antioxidative activities, and induced a suppressive effect on innate immunity. The results suggest that oxidative stress compromises renal function. We observed that ascorbic acid increased cadmium accumulation in a dose-dependent manner.


2008 ◽  
Vol 198 (2) ◽  
pp. 403-417 ◽  
Author(s):  
Ellen H Stolte ◽  
Aurélia F de Mazon ◽  
Karen M Leon-Koosterziel ◽  
Maria Jesiak ◽  
Nic R Bury ◽  
...  

In higher vertebrates, mineralo- (aldosterone) and glucocorticoids (cortisol/corticosterone) exert their multiple actions via specific transcription factors, glucocorticoid (GR) and mineralocorticoid (MR) receptors. Teleostean fishes lack aldosterone and mineral regulatory processes seem under dominant control by cortisol. Despite the absence of the classical mineralocorticoid aldosterone, teleostean fishes do have an MR with cortisol and possibly 11-deoxycorticosterone (DOC) (as alternative for aldosterone) as predominant ligands. We studied corticoid receptors in common carp (Cyprinus carpio L). Through homology cloning and bioinformatic analysis, we found duplicated GR genes and a single MR gene. The GR genes likely result from a major genomic duplication event in the teleostean lineage; we propose that the gene for a second MR was lost. Transactivation studies show that the carp GRs and MR have comparable affinity for cortisol; the MR has significantly higher sensitivity to DOC, and this favours a role for DOC as MR ligand in fish physiology. mRNA of the GRs and the MR is expressed in forebrain (in pallial areas homologous to mammalian hippocampus), corticotrophin-releasing hormone (CRH) cells in the pre-optic nucleus (NPO) and pituitary pars distalis ACTH cells, three key neural/endocrine components of the stress axis. After exposure to prolonged and strong (not to mild acute) stressors, mRNA levels of both GRs and MR become down-regulated in the brain, but not in the NPO CRH cells or pituitary ACTH cells. Our data predicts a function in stress physiology for all CRs and suggest telencephalon as a first line cortisol target in stress.


2017 ◽  
Vol 7 (1) ◽  
pp. 171
Author(s):  
Hamid Reza Adeli Bhroz ◽  
Kazem Parivar ◽  
Iraj Amiri ◽  
Nasim Hayati Roodbari

Background and Aim: Thyroid is one of the endocrine glands, (T3 and T4) play a significant role in the development of prenatal brain and the following stages. The study aimed to evaluate the effect of hypothyroidism on the amount of expression of NT4, NT3, nerve growth factor (NGF) and brain-derived neurotrophic factor (BDNF) in brain of one-day rat neonates with hypothyroidism.Materials and Methods: In total, 25 mature mice of Albino NMRI race were selected after mating, divided into three group, control, as well as low-dose and high-dose intervention groups. Samples of the control group received pure water during pregnancy, whereas subjects of the intervention group with low and high doses of the medication were administered with 20 mg and 100 mg methimazole powder (dissolved in 100 cc water), respectively. After child delivery, blood samples were obtained from mother mice to determine the level of T3 and T4 in blood serum. Following that, the brain of one-day mice were removed by surgery and assessed to determine the amount of expression of NT4, NT3, NGF and BDNF using the complete kit of RT-PCR.Results: Levels of T4 and T3 in the control group were 28 ug/dl and 1.59 ug/dl, respectively. In the low-dose intervention group, the amounts of the mentioned hormones were 8 ug/dl and 0.85 ug/dl, significantly, indicating a significant reduction in the expression of NT4, NT3, NGF and BDNF genes, compared to the control group. Moreover, T4 and T3 were 6 ug/dl and 0.79 ug/dl in the high-dose group, respectively, conveying a significant decrease in the expression of NT4, NT3, NGF and BDNF genes, compared to the control group (P<0.05).


Stroke ◽  
2016 ◽  
Vol 47 (suppl_1) ◽  
Author(s):  
Hetal Mistry ◽  
Madeline Levy ◽  
Meaghan Roy-O'Reilly ◽  
Louise McCullough

Background and Purpose: Orosomucoid-1 (ORM-1) is an abundant protein with important roles in inflammation and immunosuppression. We utilized RNA sequencing to measure mRNA levels in human ischemic stroke patients, with confirmation by serum ORM-1 protein measurements. A mouse model of ischemic stroke was then used to examine post-stroke changes in ORM-1 within the brain itself. Hypothesis: We tested the hypothesis that ORM-1 levels increase following ischemic stroke, with sex differences in protein dynamics over time. Methods: RNA sequencing was performed on whole blood from ischemic stroke patients (n=23) and controls (n=12), with Benjamini-Hochberg correction for multiple testing. Enzyme-linked immunosorbent assay was performed on serum from ischemic stroke patients (n=28) and controls (n=8), with analysis by T-test. For brain analysis, mice (n=14) were subjected to a 90-minute middle cerebral artery occlusion (MCAO) surgery and sacrificed 6 or 24 hours after stroke. Control mice underwent parallel “sham” surgery without occlusion. Western blotting was used to detect ORM-1 protein levels in whole brain, with analysis by two-way ANOVA. Results: RNA sequencing showed a 2.8-fold increase in human ORM-1 at 24 hours post-stroke (q=.0029), an increase also seen in serum ORM-1 protein levels (p=.011). Western blot analysis of mouse brain revealed that glycosylated (p=0.0003) and naive (p=0.0333) forms of ORM-1 were higher in female mice compared to males 6 hours post-stroke. Interestingly, ORM-1 levels were higher in the brains of stroke mice at 6 hours (p=.0483), while at 24 hours ORM-1 levels in stroke mice were lower than their sham counterparts (p=.0212). In both human and mouse data, no sex differences were seen in ORM-1 levels in the brain or periphery at 24 hours post-stroke. Conclusion: In conclusion, ORM-1 is a sexually dimorphic protein involved in the early (<24 hour) response to ischemic stroke. This research serves as an initial step in determining the mechanism of ORM-1 in the ischemic stroke response and its potential as a future therapeutic target for both sexes.


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