scholarly journals Glucose Elevates NITRATE TRANSPORTER2.1 Protein Levels and Nitrate Transport Activity Independently of Its HEXOKINASE1-Mediated Stimulation of NITRATE TRANSPORTER2.1 Expression

2013 ◽  
Vol 164 (1) ◽  
pp. 308-320 ◽  
Author(s):  
F. de Jong ◽  
K. Thodey ◽  
L. V. Lejay ◽  
M. W. Bevan
Keyword(s):  
Nitrate Transport ◽  
Transport Activity ◽  
Protein Levels ◽  
Stimulation Of

Effect of soleus unweighting on stimulation of insulin-independent glucose transport activity

1993 ◽  
Vol 74 (4) ◽  
pp. 1653-1657 ◽  
Author(s):  
E. J. Henriksen ◽  
L. S. Ritter
Keyword(s):  
Glucose Transport ◽  
Glucose Transporter ◽  
Insulin Binding ◽  
Transport Activity ◽  
Transporter Protein ◽  
Protein Levels ◽  
Independent Mechanism ◽  
Male Wistar Rats ◽  
Stimulation Of

Unweighting of the rat soleus by tail-cast suspension results in increased insulin action on stimulation of glucose transport, which can be explained, at least in part, by increased insulin binding and enhanced glucose transporter protein levels. Glucose transport is also activated by an insulin-independent mechanism stimulated by in vitro muscle contractions or hypoxia. Therefore, the purpose of this study was to determine if soleus unweighting leads to an enhanced response of the insulin-independent pathway for stimulation of glucose transport. The hindlimbs of juvenile male Wistar rats were suspended by a tail-cast system for 3 or 6 days. Glucose transport activity in isolated soleus strips (approximately 18 mg) was then assessed by using 2-deoxy-[1,2–3H]glucose (2-DG) uptake. Insulin (2 mU/ml) had a progressively enhanced effect on 2-DG uptake after 3 and 6 days of unweighting (+44 and +72% vs. control, respectively; both P < 0.001). At these same times, there was no difference between groups for activation of 2-DG uptake by maximally effective treatments with contractions (10 tetanuses), hypoxia (60 min), or caffeine (5 mM). These results indicate that the enhanced capacity for stimulation of glucose transport after soleus unweighting is restricted to the insulin pathway, with no apparent enhancement of the insulin-independent pathway.

scholarly journals Potential transceptor AtNRT1.13 modulates shoot architecture and flowering time in a nitrate-dependent manner

2021 ◽  
Author(s):  
Hui-Yu Chen ◽  
Shan-Hua Lin ◽  
Ling-Hsin Cheng ◽  
Jeng-Jong Wu ◽  
Yi-Chen Lin ◽  
...  
Keyword(s):  
Flowering Time ◽  
Nitrate Transport ◽  
Dependent Manner ◽  
Transport Activity ◽  
Node Number ◽  
Shoot Architecture ◽  
Glucuronidase Reporter ◽  
Uptake Activity ◽  
Delayed Flowering ◽  
Severe Growth

Abstract Compared with root development regulated by external nutrients, less is known about how internal nutrients are monitored to control plasticity of shoot development. In this study, we characterize an Arabidopsis thaliana transceptor, NRT1.13 (NPF4.4), of the NRT1/PTR/NPF family. Different from most NRT1 transporters, NRT1.13 does not have the conserved proline residue between transmembrane domains 10 and 11; an essential residue for nitrate transport activity in CHL1/NRT1.1/NPF6.3. As expected, when expressed in oocytes, NRT1.13 showed no nitrate transport activity. However, when Ser 487 at the corresponding position was converted back to proline, NRT1.13 S487P regained nitrate uptake activity, suggesting that wild-type NRT1.13 cannot transport nitrate but can bind it. Subcellular localization and β-glucuronidase reporter analyses indicated that NRT1.13 is a plasma membrane protein expressed at the parenchyma cells next to xylem in the petioles and the stem nodes. When plants were grown with a normal concentration of nitrate, nrt1.13 showed no severe growth phenotype. However, when grown under low-nitrate conditions, nrt1.13 showed delayed flowering, increased node number, retarded branch outgrowth, and reduced lateral nitrate allocation to nodes. Our results suggest that NRT1.13 is required for low-nitrate acclimation and that internal nitrate is monitored near the xylem by NRT1.13 to regulate shoot architecture and flowering time.

scholarly journals The Role of Interleukin-23 in the Early Development of Emphysema in HIV1+Smokers

2016 ◽  
Vol 2016 ◽  
pp. 1-14 ◽  
Author(s):  
Igor Z. Barjaktarevic ◽  
Ronald G. Crystal ◽  
Robert J. Kaner
Keyword(s):  
Tissue Destruction ◽  
Epithelial Lining Fluid ◽  
Protein Levels ◽  
Knowing That ◽  
Lung Epithelial ◽  
Interleukin 23 ◽  
Metalloproteinase 9 ◽  
Stimulation Of

Rationale.Matrix metalloproteinase-9 (MMP-9) expression is upregulated in alveolar macrophages (AM) of HIV1+smokers who develop emphysema. Knowing that lung epithelial lining fluid (ELF) of HIV1+smokers contains increased levels of inflammatory cytokines compared to HIV1−smokers, we hypothesized that upregulation of lung cytokines in HIV1+smokers may be functionally related to increased MMP-9 expression.Methods.Cytokine arrays evaluated cytokine protein levels in ELF obtained from 5 groups of individuals: HIV1−healthy nonsmokers, HIV1−healthy smokers, HIV1−smokers with low diffusing capacity (DLCO), HIV1+nonsmokers, and HIV1+smokers with lowDLCO.Results. Increased levels of the Th17 related cytokine IL-23 were found in HIV1−smokers with lowDLCOand HIV1+smokers and nonsmokers. Relative IL-23 gene expression was increased in AM of HIV1+individuals, with greater expression in AM of HIV1+smokers with lowDLCO. Infection with HIV1in vitroinduced IL-23 expression in normal AM. IL-23 stimulation of AM/lymphocyte coculturesin vitroinduced upregulation of MMP-9. Lung T lymphocytes express receptor IL-23R and interact with AM in order to upregulate MMP-9.Conclusion. This mechanism may contribute to the increased tissue destruction in the lungs of HIV1+smokers and suggests that Th17 related inflammation may play a role.

Immunoelectron microscopic evidence that GLUT4 translocation explains the stimulation of glucose transport in isolated rat white adipose cells

2000 ◽  
Vol 113 (23) ◽  
pp. 4203-4210 ◽  
Author(s):  
D. Malide ◽  
G. Ramm ◽  
S.W. Cushman ◽  
J.W. Slot
Keyword(s):  
Adipose Tissue ◽  
Glucose Transport ◽  
Morphological Evidence ◽  
Glut4 Translocation ◽  
Transport Activity ◽  
Brown Adipose ◽  
Quantitative Immunoelectron Microscopy ◽  
Adipose Cells ◽  
Isolated Rat ◽  
Stimulation Of

We used an improved cryosectioning technique in combination with quantitative immunoelectron microscopy to study GLUT4 compartments in isolated rat white adipose cells. We provide clear evidence that in unstimulated cells most of the GLUT4 localizes intracellularly to tubulovesicular structures clustered near small stacks of Golgi and endosomes, or scattered throughout the cytoplasm. This localization is entirely consistent with that originally described in brown adipose tissue, strongly suggesting that the GLUT4 compartments in white and brown adipose cells are morphologically similar. Furthermore, insulin induces parallel increases (with similar magnitudes) in glucose transport activity, approximately 16-fold, and cell-surface GLUT4, approximately 12-fold. Concomitantly, insulin decreases GLUT4 equally from all intracellular locations, in agreement with the concept that the entire cellular GLUT4 pool contributes to insulin-stimulated exocytosis. In the insulin-stimulated state, GLUT4 molecules are not randomly distributed on the plasma membrane, but neither are they enriched in caveolae. Importantly, the total number of GLUT4 C-terminal epitopes detected by the immuno-gold method is not significantly different between basal and insulin-stimulated cells, thus arguing directly against a reported insulin-induced unmasking effect. These results provide strong morphological evidence (1) that GLUT4 compartments are similar in all insulin-sensitive cells and (2) for the concept that GLUT4 translocation almost fully accounts for the increase in glucose transport in response to insulin.

scholarly journals A Newly Authenticated Compound from Traditional Chinese Medicine Decoction Induces Melanogenesis in B16-F10 Cells by Increasing Tyrosinase Activity

2018 ◽  
Vol 2018 ◽  
pp. 1-8 ◽  
Author(s):  
Xiu Juan Xin ◽  
Jiahong Zou ◽  
Tao Zou ◽  
Huoli Shang ◽  
Li Yun Sun
Keyword(s):  
Chinese Medicine ◽  
Traditional Chinese Medicine ◽  
Cell Number ◽  
Tyrosinase Activity ◽  
Chinese Traditional Medicine ◽  
Inhibition Rate ◽  
Disease Treatment ◽  
Protein Levels ◽  
Stimulation Of

Vitiligo is a kind of skin dysfunction on melanogenesis. The highly prevalent, chronic, and distinctive complexion changes on patients have imposed enormous psychic and economic burden on both individuals and society. Traditional Chinese Medicine (TCM) is a kind of precious source on chronic disease treatment, including skin dysfunctional diseases. In our previous study, a new compound named apigenin-7-butylene glucoside has been authenticated and purified from a prescription of Chinese traditional medicine formula which has been used clinically in vitiligo treatment. The aim of this work is to evaluate the effects of this compound on melanogenesis using melanoma cell B16-F10 in vitro. The results showed that apigenin-7-butylene glucoside had almost no cytotoxicity on B16-F10 cells within a lower dose of 5.0 μg ml-1 and enhanced the melanin level to about 41% and tyrosinase activity to 1.32-fold when compared with controls. The compound showed minor cytotoxicity to B16-F10 cells at the higher concentration of 10 μg ml-1 and 50 μg ml-1, the inhibition rate was 8.4% and 11.8%, and the melanin level and tyrosinase activity showed a decreased trend because of the lower cell number at the higher concentrations. The results indicated that apigenin-7-butylene glucoside was safe to B16-F10 cells within a lower concentration, <5.0 μg ml-1. Incubated with 5.0 ug ml-1of apigenin-7-butylene glucoside for 48 hours, the mRNA and protein levels of Tyr, Trp-1, and Trp-2 genes were all increased except Mitf in B16-F10 cells. The stimulation of apigenin-7-butylene glucoside on melanogenesis of B16-F10 cells through Tyr, Trp-1, and Trp-2 pathway highlighted the potential usage of the compound in vitiligo treatment.

Effect of Magnesium and Calcium Ions on the Photoelectron Transport Activity of Low-Salt Suspended Hydrilla verticillata Thylakoids: Possible Sites of Cation Interaction

1998 ◽  
Vol 53 (9-10) ◽  
pp. 849-856
Author(s):  
Sujata R. Mishra ◽  
Surendra Chandra Sabat
Keyword(s):  
Electron Transport ◽  
Photosystem Ii ◽  
Electron Donor ◽  
Water Oxidation ◽  
Electron Flow ◽  
Hydrilla Verticillata ◽  
Transport Activity ◽  
Low Salt ◽  
Electron Transport Activity ◽  
Stimulation Of

Stimulatory effect of divalent cations like calcium (Ca2+) and magnesium (Mg2+) was investigated on electron transport activity of divalent cation deficient low-salt suspended (LS) thylakoid preparation from a submerged aquatic angiosperm, Hydrilla verticillata. Both the cations stimulated electron transport activity of LS-suspended thylakoids having an intact water oxidation complex. But in hydroxylamine (NH2OH) - or alkaline Tris - washed thylakoid preparations (with the water oxidation enzyme impaired), only Ca2+ dependent stimulation of electron transport activity was found. The apparent Km of Ca2+ dependent stimulation of electron flow from H2O (endogenous) or from artificial electron donor (exogenous) to dichlorophenol indophenol (acceptor) was found to be identical. Calcium supported stimulation of electron transport activity in NH2OH - or Tris - washed thylakoids was electron donor selective, i.e., Ca2+ ion was only effective in electron flow with diphenylcarbazide but not with NH2OH as electron donor to photosystem II. A magnesium effect was observed in thylakoids having an intact water oxidation complex and the ion became unacceptable in NH2OH - or Tris - washed thylakoids. Indirect experimental evidences have been presented to suggest that Mg2+ interacts with the water oxidation complex, while the Ca2+ interaction is localized betw een Yz and reaction center of photosystem II.

scholarly journals Macrophages Inhibit Ciliary Protein Levels by Secreting BMP-2 Leading to Airway Epithelial Remodeling Under Cigarette Smoke Exposure

2021 ◽  
Vol 8 ◽  
Author(s):  
Zhigang Wang ◽  
Wenzhang Liang ◽  
Cuiqing Ma ◽  
Jiachao Wang ◽  
Xue Gao ◽  
...  
Keyword(s):  
Cigarette Smoke ◽  
Airway Epithelium ◽  
Airway Remodeling ◽  
Inhibitory Effect ◽  
Smoke Exposure ◽  
Cigarette Smoke Exposure ◽  
Protein Levels ◽  
Ciliary Protein ◽  
Β Tubulin ◽  
Stimulation Of

Chronic obstructive pulmonary disease (COPD) is a chronic respiratory disease with high morbidity and mortality worldwide. So far, smoking is still its leading cause. The characteristics of COPD are emphysema and airway remodeling, as well as chronic inflammation, which were predominated by macrophages. Some studies have reported that macrophages were involved in emphysema and chronic inflammation, but whether there is a link between airway remodeling and macrophages remains unclear. In this study, we found that both acute and chronic cigarette smoke exposure led to an increase of macrophages in the lung and a decrease of ciliated cells in the airway epithelium of a mouse model. The results of in vitro experiments showed that the ciliary protein (β-tubulin-IV) levels of BEAS-2B cells could be inhibited when co-cultured with human macrophage line THP-1, and the inhibitory effect was augmented with the stimulation of cigarette smoke extract (CSE). Based on the results of transcriptome sequencing, we focused on the protein, bone morphogenetic protein-2 (BMP-2), secreted by the macrophage, which might mediate this inhibitory effect. Further studies confirmed that BMP-2 protein inhibited β-tubulin-IV protein levels of BEAS-2B cells under the stimulation of CSE. Coincidentally, this inhibitory effect could be nearly blocked by the BMP receptor inhibitor, LDN, or could be interfered with BMP-2 siRNA. This study suggests that activation and infiltration of macrophages in the lung induced by smoke exposure lead to a high expression of BMP-2, which in turn inhibits the ciliary protein levels of the bronchial epithelial cells, contributing to the remodeling of airway epithelium, and aggravates the development of COPD.

scholarly journals Oocyte-Secreted Factors Synergize With FSH to Promote Aromatase Expression in Primary Human Cumulus Cells

2018 ◽  
Vol 104 (5) ◽  
pp. 1667-1676 ◽  
Author(s):  
Elie Hobeika ◽  
Marah Armouti ◽  
Hamsini Kala ◽  
Michele A Fierro ◽  
Nicola J Winston ◽  
...  
Keyword(s):  
Promoter Activity ◽  
Cumulus Cells ◽  
Aromatase Expression ◽  
Vitro Fertilization ◽  
Protein Levels ◽  
Morphogenetic Protein ◽  
Smad3 Phosphorylation ◽  
Igf1 Receptor ◽  
Stimulation Of

Abstract Context The role of growth differentiation factor 9 (GDF9) and bone morphogenetic protein 15 (BMP15) on aromatase regulation is poorly understood in humans. Objective Determine GDF9 and BMP15 effects on FSH stimulation of estradiol production in primary human cumulus granulosa cells (GCs). We hypothesized that the combination of GDF9 and BMP15 potentiates FSH-induced aromatase expression. Design Primary human cumulus GCs in culture. Setting University infertility center. Patients or Other Participants GCs of 60 women undergoing in vitro fertilization were collected. Interventions Cells were treated with GDF9 and/or BMP15 (GB) in the presence or absence of FSH, dibutyryl cAMP, or SMAD inhibitors. Main Outcome Measures Promoter activity, mRNA, protein, and estradiol levels were quantified. Results FSH and GB treatment increased CYP19A1 promoter activity, mRNA, and protein levels as well as estradiol when compared with cells treated with FSH only. GB treatment potentiated cAMP stimulation of aromatase and IGF2 stimulation by FSH. GB effects were inhibited by SMAD3 inhibitors and IGF1 receptor inhibitors. GB, but not FSH, stimulates SMAD3 phosphorylation. Conclusion The combination of GDF9 and BMP15 potently stimulates the effect of FSH and cAMP on CYP19a1 promoter activity and mRNA/protein levels. These effects translate into an increase in estradiol production. This potentiation seems to occur through activation of the SMAD2/3 and SMAD3 signaling pathway and involves, at least in part, the effect of the IGF system.

scholarly journals Polyamines regulate gene expression by stimulating translation of histone acetyltransferase mRNAs

2020 ◽  
Vol 295 (26) ◽  
pp. 8736-8745 ◽  
Author(s):  
Akihiko Sakamoto ◽  
Yusuke Terui ◽  
Takeshi Uemura ◽  
Kazuei Igarashi ◽  
Keiko Kashiwagi
Keyword(s):  
Gene Expression ◽  
Regulation Of Gene Expression ◽  
Histone Acetyltransferases ◽  
Regulate Gene Expression ◽  
Double Stranded Rna ◽  
Protein Levels ◽  
Lysine Residues ◽  
Regulate Gene ◽  
Stimulation Of

Polyamines regulate gene expression in Escherichia coli by translationally stimulating mRNAs encoding global transcription factors. In this study, we focused on histone acetylation, one of the mechanisms of epigenetic regulation of gene expression, to attempt to clarify the role of polyamines in the regulation of gene expression in eukaryotes. We found that activities of histone acetyltransferases in both the nucleus and cytoplasm decreased significantly in polyamine-reduced mouse mammary carcinoma FM3A cells. Although protein levels of histones H3 and H4 did not change in control and polyamine-reduced cells, acetylation of histones H3 and H4 was greatly decreased in the polyamine-reduced cells. Next, we used control and polyamine-reduced cells to identify histone acetyltransferases whose synthesis is stimulated by polyamines. We found that polyamines stimulate the translation of histone acetyltransferases GCN5 and HAT1. Accordingly, GCN5- and HAT1-catalyzed acetylation of specific lysine residues on histones H3 and H4 was stimulated by polyamines. Consistent with these findings, transcription of genes required for cell proliferation was enhanced by polyamines. These results indicate that polyamines regulate gene expression by enhancing the expression of the histone acetyltransferases GCN5 and HAT1 at the level of translation. Mechanistically, polyamines enhanced the interaction of microRNA-7648-5p (miR-7648-5p) with the 5′-UTR of GCN5 mRNA, resulting in stimulation of translation due to the destabilization of the double-stranded RNA (dsRNA) between the 5′-UTR and the ORF of GCN5 mRNA. Because HAT1 mRNA has a short 5′-UTR, polyamines may enhance initiation complex formation directly on this mRNA.

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